研究者データベース
永岡 謙太郎NAGAOKA Kentaroナガオカ ケンタロウ
| ■所属部署名 | 農学研究院 動物生命科学部門 | |||
| ■職名 | 教授 | |||
Last Updated :2025/09/08
業績情報
氏名・連絡先
氏名
ナガオカ ケンタロウ, 永岡 謙太郎, NAGAOKA Kentaro生年
1973Fax番号
042-367-5767eメールアドレス
nagaokak
cc.tuat.ac.jp個人ホームページ
http://www.tuat.ac.jp/~nvetphys/
主たる所属・職名
農学研究院 動物生命科学部門, 教授
その他の所属
経歴
- -
東京農工大学グローバル研究院教授
自 2018年12月13日 - -
東京農工大学農学研究院准教授
自 2016年03月01日, 至 2018年12月12日 - -
東京農工大学農学研究院テニュアトラック助教
自 2011年03月01日, 至 2016年02月28日 - -
日本学術振興会海外特別研究員（University of Massachusetts Medical School客員研究員）
自 2009年04月01日, 至 2011年02月18日 - -
東京大学大学院農学生命科学研究科 助教
自 2004年06月01日, 至 2011年02月28日 - -
協和発酵工業株式会社医薬カンパニー安全性研究所
自 2003年04月01日, 至 2004年05月31日 - -
日本学術振興会特別研究員DC1（東京大学大学院農学生命科学研究科）
自 2000年04月01日, 至 2003年03月31日
学歴
学位
教育・研究活動状況
研究分野
研究キーワード
- 生物進化の過程で、我々哺乳類は乳腺組織を獲得し母乳を作り子に与える「哺育」を繁殖戦略に取り入れ発展してきた。母乳成分は単に子を大きくさせるだけでなく、脳や腸内細菌叢の形成など健常に育たせるためにも重要です。私は、哺乳類を特徴付ける乳腺の役割やその疾病について、様々な動物種との比較を交えながら研究を進めています
担当授業科目
- 器官制御生理学(3学期・水4・農学部)
2024年, 専門科目等 - 獣医代謝生化学(1学期・火1・農学部)
2024年, 専門科目等 - 人と動物関係学(2学期・集中・農学部)
2024年, 専門科目等 - 生化学実習(1学期・火3,4・農学部)
2024年, 専門科目等 - 生理学実習(3学期・月3,4・農学部)
2024年, 専門科目等 - 統合生理学(1学期・火2・農学部)
2024年, 専門科目等 - 動物園動物学(4学期・集中・農学部)
2024年, 専門科目等 - 内分泌学(1学期・月2・農学部)
2024年, 専門科目等
科学研究費助成事業
- 基盤研究（B）
犬の動物学的特性が作り出す皮膚腸相関を基軸とした慢性腸症の病態メカニズムの解明
自 2024年, 至 2024年 - 基盤研究（B）
ホスファチジルコリン分解経路の生理的意義の解明
自 2024年, 至 2024年 - 基盤研究（B）
ゲノム進化で獲得した産後雌特有のストレス対処機構
自 2024年, 至 2024年 - 基盤研究(B)
犬の動物学的特性が作り出す皮膚腸相関を基軸とした慢性腸症の病態メカニズムの解明
自 2023年, 至 2023年 - 基盤研究（B）
ゲノム進化で獲得した産後雌特有のストレス対処機構
自 2023年, 至 2023年 - 基盤研究(B)
腸内免疫アミノ酸代謝とその変容による炎症性腸疾患増悪メカニズムの解明
自 2022年, 至 2024年 - 基盤研究(B)
犬の動物学的特性が作り出す皮膚腸相関を基軸とした慢性腸症の病態メカニズムの解明
自 2022年, 至 2022年 - 基盤研究(A)
肥満細胞腫のコンパニオン診断とリスク評価ツリーの構築
自 2018年, 至 2018年 - 基盤研究(B)
細胞質ポリアデニル化複合体に着目した上皮悪性腫瘍抑制分子の研究
自 2017年, 至 2019年 - 挑戦的研究（萌芽）
母乳成分が決定する腸内細菌叢と脳機能の関係解明
自 2017年, 至 2018年 - 基盤研究(A)
肥満細胞腫のコンパニオン診断とリスク評価ツリーの構築
自 2017年, 至 2017年 - 基盤研究（A）
妊娠成立のための子宮内環境の構築と再構築
自 2016年, 至 2016年 - 基盤研究(A)
肥満細胞腫のコンパニオン診断とリスク評価ツリーの構築
自 2016年, 至 2016年 - 基盤研究(A)
肥満細胞腫のコンパニオン診断とリスク評価ツリーの構築
自 2015年, 至 2015年 - 挑戦的萌芽研究
アミノ酸代謝酵素（LAO）が脳内アミノ酸濃度と記憶・学習に与える影響
自 2014年, 至 2015年 - 基盤研究(C)
農薬分解産物ニトロフェノールの副腎・生殖毒性機構と乳癌活性化リスクに関する研究
自 2013年, 至 2013年 - 若手研究(B)
ウシＬＡＯを発現するＴｇマウスの作出の試み 乳房炎抵抗性動物作出を目指して
自 2012年, 至 2013年 - 基盤研究(C)
農薬分解産物ニトロフェノールの副腎・生殖毒性機構と乳癌活性化リスクに関する研究
自 2012年, 至 2012年 - 基盤研究(C)
農薬分解産物ニトロフェノールの副腎・生殖毒性機構と乳癌活性化リスクに関する研究
自 2011年, 至 2011年
論文
- Relationship between the components of mare breast milk and foal gut microbiome: shaping gut microbiome development after birth
Mady, Eman A.; Osuga, Haruna; Toyama, Haruka; El-Husseiny, Hussein M.; Inoue, Ryo; Murase, Harutaka; Yamamoto, Yuki; Nagaoka, Kentaro
VETERINARY QUARTERLY
TAYLOR & FRANCIS LTD
The gut microbiota (GM) is essential for mammalian health. Although the association between infant GM and breast milk (BM) composition has been well established in humans, such a relationship has not been investigated in horses. Hence, this study was conducted to analyze the GM formation of foals during lactation and determine the presence of low-molecular-weight metabolites in mares' BM and their role in shaping foals' GM. The fecal and BM samples from six pairs of foals and mares were subjected to 16S ribosomal RNA metagenomic and metabolomic analyses, respectively. The composition of foal GM changed during lactation time; hierarchical cluster analysis divided the fetal GM into three groups corresponding to different time points in foal development. The level of most metabolites in milk decreased over time with increasing milk yield, while threonic acid and ascorbic acid increased. Further analyses revealed gut bacteria that correlated with changes in milk metabolites; for instance, there was a positive correlation between Bacteroidaceae in the foal's gut microbiota and serine/glycine in the mother's milk. These findings help improve the rearing environment of lactating horses and establish artificial feeding methods for foals.
2024年12月31日, 研究論文（学術雑誌）, 共同, 44, 1, 0165-2176, DOI(公開)(r-map), 1, 9 - Hydrogen peroxide in breast milk is crucial for gut microbiota formation and myelin development in neonatal mice
Kambe, Jun; Usuda, Kento; Inoue, Ryo; Hirayama, Kazuhiko; Ito, Masahiko; Suenaga, Ken; Masukado, Sora; Liu, Hong; Miyata, Shiho; Li, Chunmei; Kimura, Ikuo; Yamamoto, Yuki; Nagaoka, Kentaro
GUT MICROBES
TAYLOR & FRANCIS INC
Early life environment influences mammalian brain development, a growing area of research within the Developmental Origins of Health and Disease framework, necessitating a deeper understanding of early life factors on children's brain development. This study introduces a mouse model, LAO1 knockout mice, to investigate the relationship between breast milk, the gut microbiome, and brain development. The results reveal that breast milk's reactive oxygen species (ROS) are vital in shaping the neonatal gut microbiota. Decreased hydrogen peroxide (H2O2) levels in milk disrupt the gut microbiome and lead to abnormal metabolite production, including D-glucaric acid. This metabolite inhibits hippocampal myelin formation during infancy, potentially contributing to behavioral abnormalities observed in adulthood. These findings suggest that H2O2 in breast milk is crucial for normal gut microbiota formation and brain development, with implications for understanding and potentially treating neurodevelopmental disorders in humans.
2024年12月31日, 研究論文（学術雑誌）, 共同, 16, 1, 1949-0976, DOI(公開)(r-map) - Gut microbiota intervention alleviates pulmonary inflammation in broilers exposed to fine particulate matter from broiler house
Liu, Junze; Li, Yuan; Shen, Dan; Li, Xiaoqing; Wang, Kai; Nagaoka, Kentaro; Li, Chunmei
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
AMER SOC MICROBIOLOGY
The gut microbiota of poultry is influenced by a variety of factors, including feed, drinking water, airborne dust, and footpads, among others. Gut microbiota can affect the immune reaction and inflammation in the lungs. To investigate the effect of gut microbiota variation on lung inflammation induced by PM2.5 (fine particulate matter) in broilers, 36 Arbor Acres (AA) broilers were randomly assigned to three groups: control group (CON), PM2.5 exposure group (PM), and PM2.5 exposure plus oral antibiotics group (PMA). We used non-absorbable antibiotics (ABX: neomycin and amikacin) to modify the microbiota composition in the PMA group. The intervention was conducted from the 18th to the 28th day of age. Broilers in the PM and PMA groups were exposed to PM by a systemic exposure method from 21 to 28 days old, and the concentration of PM2.5 was controlled at 2 mg/m3. At 28 days old, the lung injury score, relative mRNA expression of inflammatory factors, T-cell differentiation, and dendritic cell function were significantly increased in the PM group compared to the CON group, and those of the PMA group were significantly decreased compared to the PM group. There were significant differences in both alpha and beta diversity of cecal microbiota among these three groups. Numerous bacterial genera showed significant differences in relative abundance among the three groups. In conclusion, gut microbiota could affect PM2.5-induced lung inflammation in broilers by adjusting the capacity of antigen-presenting cells to activate T-cell differentiation.IMPORTANCE Gut microbes can influence the development of lung inflammation, and fine particulate matter collected from broiler houses can lead to lung inflammation in broilers. In this study, we explored the effect of gut microbes modified by intestinal non-absorbable antibiotics on particulate matter-induced lung inflammation. The results showed that modification in the composition of gut microbiota could alleviate lung inflammation by attenuating the ability of dendritic cells to stimulate T-cell differentiation, which provides a new way to protect lung health in poultry farms. Gut microbes can influence the development of lung inflammation, and fine particulate matter collected from broiler houses can lead to lung inflammation in broilers. In this study, we explored the effect of gut microbes modified by intestinal non-absorbable antibiotics on particulate matter-induced lung inflammation. The results showed that modification in the composition of gut microbiota could alleviate lung inflammation by attenuating the ability of dendritic cells to stimulate T-cell differentiation, which provides a new way to protect lung health in poultry farms.
2024年05月21日, 研究論文（学術雑誌）, 共同, 90, 5, 0099-2240, DOI(公開)(r-map) - Influence of repeated mastitis on the milk production and metabolic status in the subsequent lactation period of dairy cattle
Miyata, Shiho; Fan, Lijie; Kambe, Jun; Qasimi, Mohammad Ibrahim; Takemoto, Satoshi; Ito, Masahiko; Li, Chunmei; Yamamoto, Yuki; Nagaoka, Kentaro
HELIYON
CELL PRESS
Recurrent mastitis poses a common challenge on dairy farms. While the impact of repeated mastitis within the same lactation has been investigated, the difference from one lactation to the next, particularly concerning the change of milk and blood metabolites, remains unclear. This study aimed to examine the difference in milk yield, milk composition, and metabolic status in the subsequent lactation between healthy and repeated mastitis in the previous lactation. The study population comprised 50 cows chosen from 400 cows, with 25 having no history of mastitis and 25 experiencing mastitis more than three times during the last lactation. Following dry-off and calving, all cows initiated a new lactation, during which no mastitis was diagnosed until the sample collection period. In the group exposed to repeated mastitis, a significant decrease in milk fat levels was observed in the subsequent lactation, while no change was observed in milk somatic cell count (SCC). Milk collected from cows that had experienced repeated mastitis in the previous lactation exhibited significant increases in the levels of free amino acids, namely valine, proline, and alanine. However, no difference in plasma levels of these amino acids was noted. These results indicate that individuals exposed to repeated mastitis have persistent milk quality changes even after dry-off. Biomarker analysis suggested that the milk valine and proline showed a moderate biomarker potential on Kappa coefficients to characterize cows that have experienced repeated mastitis. Furthermore, the results of biomarker combinations for valine and proline provided the highest specificity (100 %), positive likelihood ratio (infinity), and substantial biomarker potential on kappa coefficients (0.68). These findings significantly enhance our understanding of the pathobiology and etiology of recurrent mastitis and provide a biomarker to characterize cows that have experienced repeated mastitis in the past.
2024年05月15日, 研究論文（学術雑誌）, 共同, 10, 9, DOI(公開)(r-map) - Alpha-glycosyl isoquercitrin alleviates subchronic social defeat stress-induced depression symptoms by modulating the microbiota-gut-brain axis in mice
Liu, Hong; Li, Junjie; Takahashi, Shogo; Toyoda, Atsushi; Inoue, Ryo; Koyanagi, Mihoko; Hayashi, Shim-mo; Xu, Meiyu; Yamamoto, Yuki; Nagaoka, Kentaro
LIFE SCIENCES
PERGAMON-ELSEVIER SCIENCE LTD
Aims: Increasing evidence suggests a link between gut microbial dysbiosis and the pathogenesis of depression. Alpha-glycosyl isoquercitrin (AGIQ), consisting of isoquercitrin and its glycosylated quercetin, has beneficial effects on the gut microbiome and brain function. Here, we detected the potential antidepressant impact of a four-week administration of AGIQ and its underlying mechanisms using a mouse model of depression. Main methods: Male C57BL/6 mice were orally administered AGIQ (0.05 % or 0.5 % in drinking water) for 28 days; subchronic social defeat stress was performed in the last 10 days. Behavior tests were conducted to assess anxiety and depressive-like behaviors. Additionally, evaluations encompassed 5-hydroxytryptamine (5-HT) levels, the gut microbiota composition, lipopolysaccharide (LPS) concentrations, short-chain fatty acids levels, and intestinal barrier integrity changes. Key findings: AGIQ significantly alleviated depression-like behaviors and increased hippocampal 5-HT levels. Further, AGIQ mitigated stress-induced gut microbial abnormalities and reduced the levels of LPS in the serum, which affected the relative gene expression levels of 5-HT biosynthesis enzymes in vitro. Furthermore, AGIQ reversed the reduced butyrate levels in cecal contents and improved the impaired intestinal barrier by increasing the expression of colonic zonula occluden-1 (ZO-1) and occludin, thereby decreasing LPS leakage. Significance: Our results suggest that AGIQ could improve stress-induced depression by regulating the gut microbiome, which inhibits LPS production and maintains the gut barrier. This is the first report on the potential effect of AGIQ on depression via the gut microbiota-brain axis, shedding new light on treatment options.
2024年05月01日, 研究論文（学術雑誌）, 共同, 344, 0024-3205, DOI(公開)(r-map) - Changes in fecal microbiota during estrous cycle in healthy thoroughbred mares
Li, Junjie; Toyama, Haruka; Matsumoto, Touko; Qasimi, Mohammad Ibrahim; Inoue, Ryo; Murase, Harutaka; Yamamoto, Yuki; Nagaoka, Kentaro
JOURNAL OF EQUINE VETERINARY SCIENCE
ELSEVIER SCIENCE INC
Gut microbiota plays a crucial role in various physiological processes, including the regulation of the reproductive system and steroid sex hormones. Throughout the normal estrous cycle of healthy mares, the levels of estradiol-17 beta (E2) and progesterone (P4) in the blood exhibit periodic changes. To investigate the relationship between cyclic changes in steroid sex hormones and the gut microbiome of mares, we analyzed the fecal microbiota composition in healthy mares during the typical estrous cycle. Blood and fecal samples from five healthy mares were collected, E2 and P4 levels in serum were analyzed using radioimmunoassay (RIA), and the gut microbiome was analyzed by 16S rRNA sequencing. The overall richness and composition of the gut microbiota remained relatively stable during the normal estrous cycle in mares. The Linear Discriminant Analysis Effect Size analysis of the microbial composition during the follicular and luteal phases identified the Rhodococcus genus as differentially abundant. These findings indicate that the mare's gut microbiota's significant composition remains consistent throughout the estrous cycle. At the same time, specific low-abundance pathogenic bacteria exhibit changes that align with sexual hormonal fluctuations.
2024年04月, 研究論文（学術雑誌）, 共同, 135, 0737-0806, DOI(公開)(r-map) - Comparison of the fecal bacterial microbiota in mice, rats, and pigs after oral administration of alpha-glycosyl isoquercitrin
Liul, Hong; Inouez, Ryo; Koyanagi, Mihoko; Hayashi, Shim-mo; Watanabel, Gen; Nagaoka, Kentaro
JOURNAL OF TOXICOLOGICAL SCIENCES
JAPANESE SOC TOXICOLOGICAL SCIENCES
Alpha-glycosyl isoquercitrin (AGIQ) is composed of isoquercitrin and its glucosylated derivatives and has many biological activities, including anti-inflammatory, antioxidant, and anti-cancer properties. However, the effect of AGIQ administered orally on gut microbiota composition remains unclear. The objective of this study was to evaluate the effect of AGIQ on the gut microbiota of animals in different dose groups. Male rats and mice received different doses of AGIQ (1.5%, 3%, or 5% w/v) in diet for carcinogenic or chronic toxicity studies (rasH2 mice: 6 months; Sprague-Dawley rats: 12 months). Male minipigs received 100, 300, or 1000 mg/kg/day for 28 days. Fecal samples were collected from the different animal species and analyzed using 16S-rRNA gene sequencing. No significant changes were observed in alpha and beta diversity of the gut microbiota. Characteristic bacteria that responded to AGIQ were identified in each animal species, and, interestingly, Kineothrix alysoides, a butyrate-producing bacterium, was commonly detected in all three species, suggesting that it may be related to the biological activities of AGIQ. AGIQ selectively modulated the number of beneficial butyrate-producing commensal bacterium beneficial bacteria without changing the diversity of gut microbiota, which further supports the safe use of AGIQ in food products.
2024年, 研究論文（学術雑誌）, 共同, 49, 4, 0388-1350, 151, 161 - Gut microbiota intervention attenuates thermogenesis in broilers exposed to high temperature through modulation of the hypothalamic 5-HT pathway
Li, Sheng; Li, Xiaoqing; Wang, Kai; Li, Yansen; Nagaoka, Kentaro; Li, Chunmei
JOURNAL OF ANIMAL SCIENCE AND BIOTECHNOLOGY
BMC
Background: Broilers have a robust metabolism and high body temperature, which make them less tolerant to high-temperature (HT) environments and more susceptible to challenges from elevated temperatures. Gut microbes, functioning as symbionts within the host, possess the capacity to significantly regulate the physiological functions and environmental adaptability of the host. This study aims to investigate the effects of gut microbial intervention on the body temperature and thermogenesis of broilers at different ambient temperatures, as well as the underlying mechanism involving the gut-brain axis.Methods: Broilers were subjected to gut microbiota interference with or without antibiotics (control or ABX) starting at 1 day of age. At 21 day of age, they were divided into 4 groups and exposed to different environments for 7 d: The control and ABX groups at room temperature (RT, 24 +/- 1 degrees C, 60% relative humidity (RH), 24 h/d) and the control-HT and ABX-HT groups at high temperature (HT, 32 +/- 1 degrees C, 60% RH, 24 h/d).RESULTS : The results demonstrated that the antibiotic-induced gut microbiota intervention increased body weight and improved feed conversion in broiler chickens (P < 0.05). Under HT conditions, the microbiota intervention reduced the rectal temperature of broiler chickens (P < 0.05), inhibited the expression of avUCP and thermogenesis-related genes in breast muscle and liver (P < 0.05), and thus decreased thermogenesis capacity. Furthermore, the gut microbiota intervention blunted the hypothalamic-pituitary-adrenal axis and hypothalamic-pituitary-thyroid axis activation induced by HT conditions. By analyzing the cecal microbiota composition of control and ABX chickens maintained under HT conditions, we found that Alistipes was enriched in control chickens. In contrast, antibiotic-induced gut microbiota intervention resulted in a decrease in the relative abundance of Alistipes (P < 0.05). Moreover, this difference was accompanied by increased hypothalamic 5-hydroxytryptamine (5-HT) content and TPH2 expression (P < 0.05).Conclusions: These findings underscore the critical role of the gut microbiota in regulating broiler thermogenesis via the gut-brain axis and suggest that the hypothalamic 5-HT pathway may be a potential mechanism by which the gut microbiota affects thermoregulation in broilers.
2023年12月21日, 研究論文（学術雑誌）, 共同, 14, 1, 1674-9782, DOI(公開)(r-map) - Potential Effects of Alpha-Glycosyl Isoquercitrin on Memory by Altering the Gut Microbiota-Blood-Brain Axis in Mice
Liu, Hong; Inoue, Ryo; Koyanagi, Mihoko; Hayashi, Shim-Mo; Nagaoka, Kentaro
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
AMER CHEMICAL SOC
Alpha-glycosyl isoquercitrin (AGIQ), composed of isoquercitrin and glycosylated quercetin, has multiple biological effects. Here, we further examined the influence of AGIQ on brain function and provided its potential mechanism. Male C57BL/6 mice were treated with 0, 0.005, and 0.05% AGIQ in drinking water for 4 weeks prior to behavioral testing. Behavior tests showed that 0.05% AGIQ treatment significantly improved learning and memory function without affecting emotion. In the hippocampus, the gene expression of antioxidative defense enzymes was upregulated after 0.05% AGIQ treatment. In contrast, AGIQ caused significant alterations in the microbial abundance of genera Akkermansia, Bifidobacterium, and Alistipes associated with memory function. Metabolomics analysis identified that taurine concentration was significantly increased in serum and hippocampus from AGIQ-treated mice. The correlation analysis suggested that elevated serum taurine levels were closely related to the abundance of Akkermansia, indicating the underlying crosstalk of gut microbiota and serum metabolites. In vitro fecal culture further demonstrated that AGIQ could increase the level of Akkermansia. Taurine could exert antioxidant activity in SH-SY5Y neuroblastoma cell lines in vitro. Finally, vancomycin-induced alterations of gut microbiota attenuated the taurine increases in the serum and the antioxidant gene level in the hippocampus by AGIQ. Taken together, it is likely that AGIQ could increase genus Akkermansia abundance and ultimately increase taurine levels in serum and hippocampus to improve learning and memory function, relying on the gut microbiota-blood-brain axis. Our results supply a new view for understanding effects of AGIQ on brain function.
2023年10月20日, 研究論文（学術雑誌）, 共同, 71, 43, 0021-8561, DOI(公開)(r-map), 15991, 16002 - Amino acid metabolites enzyme in mouse milk plays an essential role in forming gut microbiota and brain gene expression during infancy
Kambe, Jun; Usuda, Kento; Ito, Masahiko; Hirayama, Kazuhiko; Inoue, Ryo; Watanabe, Gen; Nagaoka, Kentaro
ANNALS OF NUTRITION AND METABOLISM
KARGER
2023年08月, 研究論文（国際会議プロシーディングス）, 共同, 79, 0250-6807, 476, 476 - The Effect of Enzymatically Modified Isoquercitrin on Brain Function via Changing Gut Microbiota and Blood Metabolites in Mice
Liu, Hong; Inoue, Ryo; Watanabe, Gen; Koyanagi, Mihoko; Hayashi, Shim-Mo; Nagaoka, Kentaro
ANNALS OF NUTRITION AND METABOLISM
KARGER
2023年08月, 研究論文（学術雑誌）, 共同, 79, 0250-6807, 405, 405 - Xanthine-induced deficits in hippocampal behavior and abnormal expression of hemoglobin genes
Kambe, Jun; Miyata, Shiho; Li, Chunmei; Yamamoto, Yuki; Nagaoka, Kentaro
BEHAVIOURAL BRAIN RESEARCH
ELSEVIER
The prevalence of mental disorders such as depression and anxiety is high and often comorbid with other dis-eases. Chronic stress is a common risk factor for these disorders, but the mechanisms behind their development are not yet fully understood. Metabolomics has revealed a close association between purine and pyrimidine metabolism and depression and anxiety, with increased levels of serum xanthine observed in both humans and mice. Xanthine is known as purine metabolism, and this compound shows several biological activities, but the impact of xanthine on our brain function is still unclear. The hippocampus, which plays a crucial role in memory and learning, is also implicated in the pathophysiology of depression and anxiety. Here, we investigated the effects of xanthine intraperitoneal administration on spatial memory and anxiety-like behavior in mice. The findings indicated that xanthine administration induced a deficit of hippocampus-dependent spatial memory and a tendency to anxiety-like behavior in mice. RNA-seq analysis showed that xanthine administration upregulated hemoglobin (Hb) genes involved in oxygen transport in the hippocampus. The upregulated Hb genes occurred in the neuronal cells, and in vitro experiments revealed that both Hba-a1 derived from mice and HBA2 derived from humans were upregulated by xanthine treatment. These observations suggest that the xanthine-induced Hb in the hippocampus could be related to spatial memory deficit and anxiety. This study sheds light on the direct effects of xanthine on the brain and its potential role in the development of depression and anxiety symptoms caused by chronic stress.
2023年07月09日, 研究論文（学術雑誌）, 共同, 449, 0166-4328, DOI(公開)(r-map) - Effect of xylazine sedation on testicular blood flow, testicular echotexture, and circulating hormones in Shiba goats
Samir, Haney; Mandour, Ahmed S.; Radwan, Faten; Swelum, Ayman A.; Nagaoka, Kentaro; Sasaki, Kazuaki; Watanabe, Gen
VETERINARY RESEARCH COMMUNICATIONS
SPRINGER
Under field conditions, sedation may be required for a full assessment of the reproductive potential of farm animals. The present study aimed to investigate the effect of xylazine sedation on testicular hemodynamics (TBF), echotexture, testicular volume (TV), and circulating hormones in goats. Sixteen male Shiba goats were sedated using the recommended dose of xylazine (0.05 mg/Kg BW). Testicular hemodynamics were evaluated using color-pulsed Doppler ultrasonography before and after sedation. Echotexture of the testicular parenchyma and TV were assessed using computerized image analysis. Concentrations of testosterone, estradiol (E2), inhibin, cortisol, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) were measured using radioimmunoassay. There were no effects of xylazine sedation in TBF, TV, testicular parenchyma parameters, and concentrations of testosterone, inhibin, FSH, and LH (P (?) 0.05). However, after sedation, there was significantly (P (?) 0.05) lower cortisol and E2 concentration (42.88 +/- 6.79 ng/ml and 2.47 +/- 0.58 pg/ml, respectively) than before sedation (94.89 +/- 13.74 ng/ml and 8.65 +/- 1.79 pg/ml, respectively). The required time to perform the full scanning of the testis was significantly lower (8.50 +/- 0.38 min) after xylazine sedation compared to the non-sedated goats (25.75 +/- 1.14 min). In conclusion, xylazine sedation may be practically recommended for the evaluation of TBF in goats because it did not significantly alter velocities parameters and Doppler indices of blood flow within the testicular arteries. Most plasma hormones did not significantly change; however, E2 and cortisol were significantly reduced after xylazine administration.
2023年06月, 研究論文（学術雑誌）, 共同, 47, 2, 0165-7380, DOI(公開)(r-map), 849, 859 - L-amino acid oxidase-1 is involved in the gut-liver axis by regulating 5-aminolevulinic acid production in mice
Qasimi, Mohammad Ibrahim; Fukuzawa, Susumu; Suenaga, Ken; Kambe, Jun; Li, ChunMei; Li, Chunmei; Tomonaga, Shozo; Kawase, Takahiro; Tsukahara, Takamitsu; Hirayama, Kazuhiko; Inoue, Ryo; Yamamoto, Yuki; Nagaoka, Kentaro
JOURNAL OF VETERINARY MEDICAL SCIENCE
JAPAN SOC VET SCI
. L-amino acid oxidase (LAAO) is a metabolic enzyme that converts L-amino acids into ketoacids, ammonia, and hydrogen peroxide (H2O2). The generated H2O2 has previously been shown to have antibacterial and gut microbiota-modulatory properties in LAO1 knock-out (KO) mice. Since most microbial metabolites reach the liver through the portal vein, we examined gut-liver interactions in LAO1 KO mice. We found lower total cholesterol levels, higher glutamic pyruvic transaminase (GPT) levels in the serum, and higher pro-inflammatory cytokine mRNA expression in the liver tissue. In wild-type (WT) mice, LAO1 was expressed in gut tissues (ileum and colon). Microbiome analysis revealed that the abundance of some bacteria was altered in LAO1 KO mice. However, short-chain fatty acid (SCFAs) levels in cecal feces and gut permeability did not change. Fecal microbiota transplantation (FMT) revealed that feces from LAO1 KO mice slightly stimulated pro-inflammatory cytokine expression in the liver. During metabolomic analysis, 5-aminolevulinic acid (5-ALA) was the only metabolite found to be significantly upregulated in the portal and abdominal veins of the LAO1 KO mice. Intraperitoneal administration of 5-ALA to WT mice significantly increased IL-6 mRNA expression in the liver. These observations suggest that gut LAO1 plays a role in regulating 5-ALA production and that a high level of 5-ALA stimulates the liver to increase pro-inflammatory cytokine expression by disrupting LAO1 in mice.
2023年06月, 研究論文（学術雑誌）, 共同, 85, 6, 0916-7250, DOI(公開)(r-map), 672, 679 - Exposure to Particulate Matter in the Broiler House Causes Dyslipidemia and Exacerbates It by Damaging Lung Tissue in Broilers
Shen, Dan; Guo, Qi; Huang, Kai; Mao, Weijia; Wang, Kai; Zeng, Wenjie; Li, Yansen; Guo, Zhendong; Nagaoka, Kentaro; Li, Chunmei
METABOLITES
MDPI
The high concentration of particulate matter (PM) in broiler houses seriously endangers the biological safety of broilers and causes low growth performance, deserving more attention. This study aimed to investigate the effects of PM collected from a broiler house on the lung and systemic inflammatory responses and liver lipid anabolic process in broilers. Broilers were systemically exposed to fresh air (control) and 4 mg center dot m(-3) and 8 mg center dot m(-3) total suspended particles (TSP). Lung, liver, and serum were sampled after 7 (E7) and 14 (E14) days of PM exposure and 7 days after self-recovery (R 7). Corresponding kits were used to assay the inflammatory cytokines and serum biochemical indicators. The expression levels of genes related to lipid metabolism were detected by real-time polymerase chain reaction (RT-PCR) assay. The results showed a significant decrease in the average daily gain in broilers for 7 days of PM exposure (p < 0.05) and clear lung and liver inflammations in PM groups. In addition, upregulation of lung interleukin (IL)-1 beta and IL-8 and serum low-density lipoprotein cholesterol (LDL-C) and triglyceride (TG) occurred after 7 days of PM exposure (p < 0.05), and upregulation of lung serum tumor necrosis factor (TNF)-alpha and cholesterol (CHOL) occurred after 14 days of PM exposure (p < 0.05). A decrease in serum total antioxidant capacity (T-AOC) and glutathione peroxidase (GSH-px) levels was found after 14 days of PM exposure (p < 0.05), and the GSH-px level was maintained until 7 days after cessation of exposure (p < 0.05). Seven days after cessation of exposure, the expression levels of 3-hydroxy-3-methylglutaryl-CoA synthase 2 (Hmgcs2) and fatty acid synthase (Fas) genes significantly increased (p < 0.05) and decreased (p < 0.05), respectively. These results demonstrate that exposure to PM in broiler houses can induce systemic inflammation and dyslipidemia through local pulmonary inflammation and also exert toxic effects on the liver by disturbing the expression of genes involved in the hepatic lipid anabolic process.
2023年03月, 研究論文（学術雑誌）, 共同, 13, 3, DOI(公開)(r-map) - Pulmonary microbiota intervention alleviates fine particulate matter-induced lung inflammation in broilers
Zhou, Zilin; Shen, Dan; Wang, Kai; Liu, Junze; Li, Mingyang; Win-Shwe, Tin-Tin; Nagaoka, Kentaro; Li, Chunmei
JOURNAL OF ANIMAL SCIENCE
OXFORD UNIV PRESS INC
Fine particulate matter (PM2.5) released during the livestock industry endangers the respiratory health of animals. Our previous findings suggested that broilers exposed to PM2.5 exhibited lung inflammation and changes in the pulmonary microbiome. Therefore, this study was to investigate whether the pulmonary microbiota plays a causal role in the pathogenesis of PM2.5-induced lung inflammation. We first used antibiotics to establish a pulmonary microbiota intervention broiler model, which showed a significantly reduced total bacterial load in the lungs without affecting the microbiota composition or structure. Based on it, 45 AA broilers of similar body weight were randomly assigned to three groups: control (CON), PM2.5 (PM), and pulmonary microbiota intervention (ABX-PM). From 21 d of age, broilers in the ABX-PM group were intratracheally instilled with antibiotics once a day for 3 d. Meanwhile, broilers in the other two groups were simultaneously instilled with sterile saline. On 24 and 26 d of age, broilers in the PM and ABX-PM groups were intratracheally instilled with PM2.5 suspension to induce lung inflammation, and broilers in the CON group were simultaneously instilled with sterile saline. The lung histomorphology, inflammatory cytokines' expression levels, lung microbiome, and microbial growth conditions were analyzed to determine the effect of the pulmonary microbiota on PM2.5-induced lung inflammation. Broilers in the PM group showed lung histological injury, while broilers in the ABX-PM group had normal lung histomorphology. Furthermore, microbiota intervention significantly reduced mRNA expression levels of interleukin-1 & beta;, tumor necrosis factor-& alpha;, interleukin-6, interleukin-8, toll-like receptor 4 and nuclear factor kappa-B. PM2.5 induced significant changes in the & beta; diversity and structure of the pulmonary microbiota in the PM group. However, no significant changes in microbiota structure were observed in the ABX-PM group. Moreover, the relative abundance of Enterococcus cecorum in the PM group was significantly higher than that in the CON and ABX-PM groups. And sterile bronchoalveolar lavage fluid from the PM group significantly promoted the growth of E. cecorum, indicating that PM2.5 altered the microbiota's growth condition. In conclusion, pulmonary microbiota can affect PM2.5-induced lung inflammation in broilers. PM2.5 can alter the bacterial growth environment and promote dysbiosis, potentially exacerbating inflammation. Lay Summary Fine particulate matter (PM2.5) in broiler houses has a negative impact on broiler respiratory tracts, and PM2.5 exposure can induce lung inflammation and cause microbiota dysbiosis. The pulmonary microbiota is involved in maintaining immune homeostasis in the lungs, and a variety of lung diseases exhibit microbiota disturbances. However, the correlation between the pulmonary microbiota and PM2.5-induced lung inflammation is poorly understood. This study aimed to investigate whether the pulmonary microbiota influenced PM2.5-induced lung inflammation. We use antibiotics to reduce the quantity of bacteria in the lungs without destroying their composition. PM2.5 was then used to induce lung inflammation in both untreated and intervened pulmonary microbiota broilers. Compared to untreated microbiota broilers, intervened microbiota broilers had less morphological lung tissue injury and lower inflammatory factor expression levels after PM2.5 exposure. Furthermore, the intervened microbiota broilers' microbiota structure remained normal, while the untreated microbiota broilers showed dysbiosis. This dysbiosis is closely linked to changes in the microbial growth environment due to the inflammatory response. This suggested that the pulmonary microbiota affects PM2.5-induced lung inflammation in broilers. Dysbiosis caused by inflammation that alters the conditions for bacterial growth may exacerbate inflammation. Pulmonary microbiota are involved in the pathogenesis of PM2.5-induced lung inflammation in broilers. The inflammatory response induced by PM2.5 can directly alter the conditions for bacterial growth, thereby selectively promoting the multiplication of certain pathogenic bacteria, and this dysbiosis may be an important factor to exacerbated inflammation.
2023年01月03日, 研究論文（学術雑誌）, 共同, 101, 0021-8812, DOI(公開)(r-map) - Age-related accumulation of persistent organic chemicals in captive king penguins (Aptenodytes patagonicus)
Terajima, Taiki; Shibahara, Anzu; Nakano, Yoshiaki; Kobayashi, Shohei; Godwin, John R.; Nagaoka, Kentaro; Watanabe, Gen; Takada, Hideshige; Mizukawa, Kaoruko
JOURNAL OF VETERINARY MEDICAL SCIENCE
JAPAN SOC VET SCI
Persistent organic chemicals are non-biodegradable in nature and have a tendency to bioaccumulate in the top organisms of the food chain. We measured persistent organic chemicals, including polychlorinated biphenyls (PCBs), dichlorodiphenyldichloroethylene (DDE), and benzotriazole-based ultraviolet stabilizers (UV-BTs), in the serum of captive king penguins (Aptenodytes patagonicus) using gas chromatography with an electron capture detector and mass spectrometry to examine their age-related accumulation. PCBs, DDE, UV-PS, and UV-9 were detected in the blood of captive king penguins, and the concentrations of total PCBs, DDE, and UV-9 were positively correlated with age. These results suggest that there is a similar age-related accumulation of persistent organic chemicals in marine birds in the wild, and that older individuals are at a higher risk of contamination.
2022年11月, 研究論文（学術雑誌）, 共同, 84, 11, 0916-7250, DOI(公開)(r-map), 1551, 1555 - Individual variations and effects of birth facilities on the fecal microbiome of laboratory-bred marmosets (Callithrix jacchus) assessed by a longitudinal study
Shigeno, Yuko; Liu, Hong; Sano, Chie; Inoue, Ryo; Niimi, Kimie; Nagaoka, Kentaro
PLOS ONE
PUBLIC LIBRARY SCIENCE
Laboratory animals are used for scientific research in various fields. In recent years, there has been a concern that the gut microbiota may differ among laboratory animals, which may yield different results in different laboratories where in-vivo experiments are performed. Our knowledge of the gut microbiota of laboratory-reared common marmosets (Callithrix jacchus) is limited; thus, in this study, we analyzed the daily changes in fecal microbiome composition, individual variations, and effects of the birth facility in healthy female laboratory-reared marmosets, supplied by three vendors. We showed that the marmoset fecal microbiome varied among animals from the same vendor and among animals from different vendors (birth facility), with daily changes of approximately 37%. The fecal microbiome per vendor is characterized by alpha diversity and specific bacteria, with Bifidobacterium for vendor A, Phascolarctobacterium for vendor B, and Megamonas for vendor C. Furthermore, we found that plasma progesterone concentrations and estrous cycles were not correlated with daily fecal microbiome changes. In contrast, animals with an anovulatory cycle lacked Megamonas and Desulfovibrio bacteria compared to normal estrous females. This study suggests that the source of the animal, such as breeding and housing facilities, is important for in-vivo experiments on the marmoset gut microbiota.
2022年08月30日, 研究論文（学術雑誌）, 共同, 17, 8, 1932-6203, DOI(公開)(r-map) - Effects of sugar cane extract on steroidogenesis in testicular interstitial cells of male Japanese quail (Coturnix japonica)
Pu, Shaoxia; Kobayashi, Shohei; Mizu, Masami; Furuta, Toma; Nagaoka, Kentaro; Gore, Andrea C.; Crews, David; Watanabe, Gen
JOURNAL OF EXPERIMENTAL ZOOLOGY PART A-ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY
WILEY
Sugar cane extract (SCE) is the end product of glucose, fructose, and sucrose elimination in molasses. SCE has various biological effects, such as anti-inflammation arid antioxidation, and it is commonly found in animal feed. The present research is aimed at investigating the reproductive endocrine influence of SCE in male Japanese quails (Coturnix japonica) by feeding SCE containing food. In addition, in vitro Leydig cell culture was conducted to clarify the mechanism of SCE's influence. Our results showed that SCE feed extended the latency to the first neck grab, decreased male quail testis and epididymis weights, cloaca gland size, and reduced serum testosterone concentrations. Steroidogenic enzymes 3 beta HSD, 17 beta HSD, P450c17, and P450scc gene expression in the testis were decreased in the SCE groups. Western blot analysis showed decreased 3 beta HSD in the testis after feeding SCE. Isolated testicular interstitial cells cultured with SCE and ovine-LH suppressed testosterone secretion and 3 beta HSD gene expression. In conclusion, SCE as a feed additive has an impact on the sexual behavior and reproductive function of male Japanese quail, with the suppression of steroidogenesis in the Leydig cell. Our results may provide beneficial information to the livestock management and the poultry industry.
2022年08月, 研究論文（学術雑誌）, 共同, 337, 7, 2471-5638, DOI(公開)(r-map), 760, 767 - Characterization of Serum Metabolome and Proteome Profiles Identifies SNX5 Specific for Pregnancy Failure in Holstein Heifers
Kusama, Kazuya; Bai, Rulan; Matsuno, Yuta; Ideta, Atsushi; Sakurai, Toshihiro; Nagaoka, Kentaro; Hori, Masatoshi; Imakawa, Kazuhiko
LIFE-BASEL
MDPI
Pregnancy loss predominantly occurs during the first 3-4 weeks due to fertilization failure or early embryonic losses in cattle. Insufficient biochemical communication between conceptus (embryo plus extraembryonic membranes) and endometrium has been suspected as the primary cause for early embryonic losses. If molecules regulating this communication were identified, molecular mechanisms associated with early pregnancy losses could be better understood. To identify candidate molecules as detection markers of non-pregnant or females undergoing embryonic loss, peripheral blood from embryo-transferred heifers on day 7 (day 0 = day of estrus) were collected on days 17 (pre-attachment), 20 (during attachment), and 22 (post-attachment), which were subjected to metabolome and global proteome iTRAQ analyses. The metabolome analysis partly divided serum components into pregnant or not. In the iTRAQ analysis, heatmap analysis with top 25 proteins was separated into pregnant or not on day 20 or 22. Furthermore, receiver operating characteristic curve (ROC) analysis identified five candidate proteins detecting non-pregnant heifers, of which SNX5 in day 22 serum had the highest area under the curve (AUC): 0.983. We also detected SNX5 in day 22 serum from non-pregnant heifers using western blotting. These results suggest that high SNX5 in day 22 serum could predict early pregnancy loss in heifers.
2022年02月, 研究論文（学術雑誌）, 共同, 12, 2, DOI(公開)(r-map) - Diurnal rhythms in testicular blood flow, testicular morphometry and reproductive hormones in Shiba goats
Samir, Haney; Mandour, Ahmed S.; Radwan, Faten; Swelum, Ayman A.; Yoshida, Tomohiko; Tanaka, Ryou; Nagaoka, Kentaro; Watanabe, Gen
REPRODUCTION FERTILITY AND DEVELOPMENT
CSIRO PUBLISHING
Context. Testicular blood flow (TBF) is crucial for testicular function. The pattern of TBF in Shiba goats indicates seasonal variations. Aims. This study aimed to investigate the effect of diurnal variations on TBF, testis volume (TV), testicular echogenicity, and reproductive hormones in goats over a 24-h period. Methods. In three trials that went for three consecutive days each, 12 bucks were scanned using Triplex ultrasonography to assess the TV, pixel intensity of testicular echotexture (PIX), and Doppler indices of TBF (resistive index: RI and pulsatility index: PI) in four-time points a day (at 6.00, 12.00, 18.00, and 00.00 h). Concomitantly, the changes in circulating FSH, LH, inhibin, testosterone (T), estradiol (E2), cortisol, and melatonin were assessed. Key results. Results revealed diurnal alterations in the calculated RI of TBF and the PIX of testicular parenchyma (P < 0.05). Lower RI values of the TBF were observed at 6.00 h compared to other time points. There were significant diurnal alterations in the levels of FSH (P < 0.05), LH (P < 0.05), T (P < 0.0001), E2 (P < 0.0001), cortisol (P < 0.0001), and melatonin (P < 0.0001). FSH attained a higher concentration at 18.00 h compared to 12.00 h. Concentrations of LH were significantly higher at 06.00 h compared to those at 18.00 h. Concentrations of T were significantly higher at 6.00 compared to other time points. E2 showed higher concentrations at 6.00 h and 00.00 h compared to 12.00 h and 18.00 h. On the contrary, concentrations of cortisol were significantly higher at 12.00 h and 18.00 h compared to 06.00 h and 00.00 h. The highest concentrations of melatonin were observed at 00.00 h compared to other time points, while the lowest concentrations were at 12.00 h. Conclusions. Diurnal rhythm induces significant changes in TBF, testicular PIX, and circulating FSH, LH, T, E2, cortisol, and melatonin over the 24-h day. Implications. The outcomes of the study are reflected in the advisability of monitoring the TBF at a fixed time a day to avoid the circadian rhythm effect.
2022年, 研究論文（学術雑誌）, 共同, 34, 16, 1031-3613, DOI(公開)(r-map), 1043, 1051 - Contrasting gut microbiota in captive Eurasian otters (Lutra lutra) by age
Okamoto, Yumiko; Ichinohe, Natsumi; Woo, Cheolwoon; Han, Sung-Yong; Kim, Hyeong-Hoo; Ito, Sakura; Nakamura, Chiho; Kumura, Junpei; Nagaoka, Kentaro; Yamamoto, Naomichi
ARCHIVES OF MICROBIOLOGY
SPRINGER
Understanding the gut microbiota characteristics of endangered species such as the Eurasian otter (Lutra lutra), especially in their early stages of life, could be essential for improving their management and ex situ conservation strategies. Here, we analyzed the gut microbiota diversity, composition, and function of captive Eurasian otters at different ages using high-throughput 16S rRNA gene sequencing. We found that: (1) Clostridiaceae was abundant in all age stages; (2) Lactococcus in cubs is thought to predominate for digesting milk; (3) bacteria associated with amino acid metabolism increase with age, while bacteria associated with carbohydrate metabolism decrease with age, which is likely due to decrease in dietary carbohydrate content (e.g., milk) and increase in dietary protein contents (e.g., fishes) with age; and (4) fish-related bacteria were detected in feces of healthy adults and juveniles. Overall, the gut microbiota of captive Eurasian otters was taxonomically and functionally different by age, which is thought to be attributed to the difference in the diet in their life stages. This study provided baseline information regarding the gut microbiota of Eurasian otters for the first time and contributes to improvement in their management in captivity.
2021年11月, 研究論文（学術雑誌）, 共同, 203, 9, 0302-8933, DOI(公開)(r-map), 5405, 5416 - Role of Two-Dimensional Speckle-Tracking Echocardiography in Early Detection of Left Ventricular Dysfunction in Dogs
Hamabe, Lina; Mandour, Ahmed S.; Shimada, Kazumi; Uemura, Akiko; Yilmaz, Zeki; Nagaoka, Kentaro; Tanaka, Ryou
ANIMALS
MDPI
Simple Summary Two-dimensional speckle-tracking echocardiography represents an advanced imaging technique that allows the analysis of global and regional myocardial function, cardiac rotation and synchronicity using deformation imaging. It has gained growing importance over the last decade, especially in human medicine as a method of evaluating myocardial function. This review aims to give an overview of the current understanding of this technique and its clinical applicability in the field of veterinary medicine with a focus on early detection of left ventricular dysfunction in dogs. Two-dimensional speckle-tracking echocardiography (2D-STE) is an advanced echocardiographic technique based on deformation imaging that allows comprehensive evaluation of the myocardial function. Clinical application of 2D-STE holds great potential for its ability to provide valuable information on both global and regional myocardial function and to quantify cardiac rotation and synchronicity, which are not readily possible with the conventional echocardiography. It has gained growing importance over the past decade, especially in human medicine, and its application includes assessment of myocardial function, detection of subclinical myocardial dysfunction and serving as a prognostic indicator. This review illustrates the fundamental concepts of deformation analysis and gives an overview of the current understanding and its clinical application of this technique in veterinary medicine, with a focus on early detection of left ventricular (LV) dysfunction in dogs.
2021年08月, 研究論文（学術雑誌）, 共同, 11, 8, 2076-2615, DOI(公開)(r-map) - Ovarian progesterone suppresses depression and anxiety-like behaviors by increasing the Lactobacillus population of gut microbiota in ovariectomized mice
Sovijit, Watcharin N.; Sovijit, Watcharee E.; Pu, Shaoxia; Usuda, Kento; Inoue, Ryo; Watanabe, Gen; Yamaguchi, Hirohito; Nagaoka, Kentaro
NEUROSCIENCE RESEARCH
ELSEVIER IRELAND LTD
Depression and anxiety, which are severe symptoms during menopause, are caused by ceased ovarian activity and declined serum progesterone levels. Studies have demonstrated that gut microbiota can regulate brain function and change the microbiota composition during the perimenopause period. This study investigated whether progesterone affects depressant and anxious behaviors via gut microbiota. In ovariectomized (OVX) mice, treatment with progesterone improved depressive and anxious behav-iors, and gut microbiota composition was significantly changed. In particular, increased Lactobacillus spp. were observed in these mice. Reduction of microbiota by antibiotic treatment abolished the effect of progesterone on depression and anxiety. In addition, administration of Lactobacillus (L.) reuteri that was increased by progesterone also reduced the depressant behavior in OVX mice, and BDNF gene expression was elevated by progesterone treatment and L. reuteri administration in the hippocampus. Moreover, we found that progesterone stimulated the growth of L. reuteri in vitro. In summary, our findings indi-cate that progesterone reduces depression and anxiety through changes in gut microbiota composition, particularly by increasing the Lactobacillus spp. population. (c) 2019 Published by Elsevier B.V.
2021年07月, 研究論文（学術雑誌）, 共同, 168, 0168-0102, DOI(公開)(r-map), 76, 82 - Day 7 Embryos Change the Proteomics and Exosomal Micro-RNAs Content of Bovine Uterine Fluid: Involvement of Innate Immune Functions
Kusama, Kazuya; Rashid, Mohammad B.; Kowsar, Rasoul; Marey, Mohamed A.; Talukder, Anup K.; Nagaoka, Kentaro; Shimada, Masayuki; Khatib, Hasan; Imakawa, Kazuhiko; Miyamoto, Akio
FRONTIERS IN GENETICS
FRONTIERS MEDIA SA
This study aimed to characterize proteins and exosomal microRNAs (miRNAs) in the uterine flushings (UF) of cows associated with Day 7 (D7) pregnancy using the embryo donor cows of the embryo transfer program. Superovulated cows either were inseminated (AI cows) or remained non-inseminated (Ctrl cows). UF was collected on D7 in the presence of multiple embryos (AI cows) or without embryos (Ctrl cows) and subjected to isobaric tags for relative and absolute quantification protein analysis. A total of 336 proteins were identified, of which 260 proteins were more than 2-fold higher in AI cows than Ctrl cows. Gene ontology analysis revealed that many differentially expressed proteins were involved in neutrophil-related and extracellular vesicular exosome-related terms. In silico analysis of proteins with higher concentrations in the UF of AI identified 18 uniquely expressed proteins. Exosomes were isolated from the UF, from which RNA was subjected to miRNA-seq, identifying 37 miRNAs. Of these, three miRNAs were lower, and six miRNAs were higher in the UF of AI cows than those of Ctrl ones. The principal component analysis displayed a close association in miRNA and protein between bta-miR-29a, bta-miR-199b, SUGT1, and PPID. In addition, the receiver operating characteristic curve analysis showed that SUGT1 was the best predictor for the presence of embryos in the uterus. These findings suggest that the presence of multiple D7 embryos in the uterus can lead to significant changes in the protein composition and exosomal miRNA contents of UF, which could mediate innate immunological interactions between the pre-hatching embryo and the uterus in cows.
2021年06月28日, 研究論文（学術雑誌）, 共同, 12, DOI(公開)(r-map) - L-amino acid oxidase 1 in sperm is associated with reproductive performance in male mice and bulls
Zhang, Haolin; Liu, Hong; Kataoka, Sachi; Kinukawa, Masashi; Uchiyama, Kyoko; Kambe, Jun; Watanabe, Gen; Jin, Wanzhu; Nagaoka, Kentaro
BIOLOGY OF REPRODUCTION
OXFORD UNIV PRESS INC
Sperm quality is an important indicator of male fertility, and a suitable biomarker enables the selection of high-quality spermatozoa. We previously found that L-amino acid oxidase encoded by the L-amino acid oxidase 1 (Lao1) gene exerts biological roles in the mammary gland and brain by converting specific L-amino acids into keto acids, ammonia, and hydrogen peroxide (H2O2). Here, we describe the role of Lao1 in male reproduction. Lao1-deficient (Lao1(-/-)) male mice generated fewer pregnant embryos and pups as well as lower ratios of fertilized oocytes and even ovulated number was not different, suggesting that male subfertility caused the smaller litters. We found that LAO1 expressed in acrosomes is associated with high malformation ratios and low viability of Lao1(-/-) sperm. Wild-type (WT) sperm produced more H2O2 than Lao1(-/-) sperm, and 10 mu M H2O2 restored knockout (KO) sperm viability in vitro. In addition, the sperm ratio of induced acrosome reaction was higher in WT than in Lao1(-/-) sperm incubated with the calcium ionophore A23187. Moreover, LAO1 expression was abundant in bovine sperm with high fertilization ratios. We concluded that LAO1 localized in the sperm acrosome influences sperm viability and morphology as well as the acrosome reaction, and that LAO1-deficient sperm might cause male subfertility. Thus, LAO1 might serve as a novel marker for selecting high-quality spermatozoa, especially for livestock reproduction. Summary sentence LAO1 localized in the sperm acrosome may influence sperm viability and acrosome reaction by metabolizing L-amino acid to produce H2O2.
2021年05月, 研究論文（学術雑誌）, 共同, 104, 5, 0006-3363, DOI(公開)(r-map), 1154, 1161 - Estrogen promotes increased breast cancer cell proliferation and migration through downregulation of CPEB1 expression
Sovijit, Watcharee; Sovijit, Watcharin; Ishii, Yuriko; Kambe, Jun; Fujita, Tomoyuki; Watanabe, Gen; Yamaguchi, Hirohito; Nagaoka, Kentaro
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
ACADEMIC PRESS INC ELSEVIER SCIENCE
The polyadenylation element binding protein 1 (CPEB1) plays an important role in the regulation of poly(A) tail length at the 3'UTR of mRNA during transcription. Downregulation of CPEB1 expression, which is associated with the loss of mammary epithelial polarity, has been reported in breast cancer. CPEB1 downregulation leads to an increase in tumor aggressiveness of breast cancer. Breast cancer is also known to be responsive to the treatment with steroid hormones, which promotes cancer development and progression; however, the nature of these associations remains unclear. This study aimed to investigate whether estrogen and progesterone impacted CPEB1 expression in breast cancer in order to regulate cell proliferation and migration. MCF7 cell proliferation was increased in response to estrogen treatment, and estrogen application suppressed the expression of CPEB1 mRNA. Cells treated with estrogen or those depleted for CPEB1 by shRNA showed increased wound healing capacity compared with that of control cells in migration assay. Moreover, we found that CPEB1 level of expression in human breast cancer tissue was low compared with that in the healthy tissue. CPEB1 expression was downregulated in response to estrogen activity and in turn, that caused a significantly induced cell migration in breast cancer cells. This suggests that CPEB1 is one of the estrogen responsive genes, which stimulates breast cancer progression. Increasing and/or maintaining CPEB1 expression level has the potential to control breast cancer behavior. (C) 2020 Elsevier Inc. All rights reserved.
2021年01月01日, 研究論文（学術雑誌）, 共同, 534, 0006-291X, DOI(公開)(r-map), 871, 876 - Assessment of correlations and concentrations of salivary and plasma steroids, testicular morphometry, and semen quality in different climatic conditions in goats
Samir, Haney; Nyametease, Paul; Elbadawy, Mohamed; Fathi, Mohamed; Mandour, Ahmed S.; Radwan, Faten; Nagaoka, Kentaro; Sasaki, Kazuaki; Watanabe, Gen
THERIOGENOLOGY
ELSEVIER SCIENCE INC
The current study aimed to investigate whether steroids (testosterone, estradiol, and cortisol) in the saliva of goats reflects their concentrations in the plasma. Also, it aimed at ascertaining, for the first time, the effect of changes in climatic conditions (spring versus summer) on the aforementioned steroids, testicular volume, testicular echotexture (pixel intensity; PI, and integrated density; ID), and semen quality in goats. Saliva and plasma samples were collected from 7 male Shiba goats weekly in spring and summer for measurement of testosterone (T; ng/ml), estradiol (E2; pg/ml), and cortisol (ng/ml) using radioimmunoassay. The changes in testicular volumes (TV/ml) and echogenicity were monitored weekly using ultrasonographic assessments concomitantly with subjective evaluations of semen parameters. Results revealed a highly significant positive correlation (r = 0.72; P < 0.0001) between plasma and salivary cortisol. Mild significant positive correlation was found between salivary and plasma T levels (r = 0.31; P < 0.002). However, low non-significant negative correlation was reported between salivary and plasma E2 levels (r = -0.24; P > 0.05). Higher levels of salivary cortisol were found in summer than in the spring (3.8 +/- 0.6 ng/ml versus 1.4 +/- 0.3 ng/ml; P < 0.001). However, no differences in levels of T, E2, and plasma cortisol were recorded between spring and summer (P > 0.05). Values of testicular PI and ID were significantly (P < 0.001) higher in the summer (94.5 +/- 4.9, 258,388 +/- 13,190, respectively) than in the spring (74.0 +/- 2.1, 200,922 +/- 5704, respectively). Meanwhile, TV and semen parameters did not significantly differ between spring and summer. In conclusion, saliva can be considered as an alternative biological fluid for the measurement of cortisol and T, but not suitable for E2. Climatic conditions significantly impact the levels of cortisol in saliva and testicular echogenicity in goats. (C) 2020 Elsevier Inc. All rights reserved.
2020年11月, 研究論文（学術雑誌）, 共同, 157, 0093-691X, DOI(公開)(r-map), 238, 244 - The relation between liver damage and reproduction in female Japanese quail (Coturnix japonica) exposed to high ambient temperature
Pu, Shaoxia; Usuda, Kento; Nagaoka, Kentaro; Gore, Andrea; Crews, David; Watanabe, Gen
POULTRY SCIENCE
ELSEVIER
Reproductive failure associated with heat stress is a well-known phenomenon in poultry. High temperatures also induce various metabolic disturbances in many animals. Because the liver plays a central role in metabolism, the present study aimed to clarify the relationship between liver and reproduction in Japanese quails exposed to high temperatures. In the consecutive 20-D experimental period, quails were treated with 25 degrees C (control) or 34 degrees C (heat) from 12:00 to 16:00. Eggs were collected for hatching. On completion of the experimental period, quails were humanely euthanized for hormone analyses (e.g., serum and ovarian follicles). Serum metabolites were analyzed using GC/MS. Liver and ovary samples were collected for mRNA levels, histomorphology, and metabolic analysis. Ovary and oviduct weights significantly decreased after daily heat exposure. The number and weight of hierarchical follicles also decreased. Consequently, egg weight decreased. Although there was no difference in fertilization rate, chick birth weight significantly decreased in the heated group. Corticosterone and 17 beta-estradiol in the serum significantly increased in the heated group. Yolk corticosterone and 17 beta-estradiol concentration and content were higher in the heated group. Ovary sterologenic enzymes gene P450scc and estrogen receptor expression level increased. The FSH receptor decreased in heat stressed quails. MetaboAnalyst analysis indicated that high temperature affects propanoate metabolism, betaalanine metabolism, aspartate metabolism, and histidine metabolism. Triglyceride and cholesterol levels in the liver increased in the heated group. The heated group also had an increased mRNA expression of AGPAT5, apoptosis gene caspase3, and the immunocytokine genes IL-6 and TLR4. However, NF-KB gene expression decreased. These results suggest that high temperatures affect lipid metabolism and apoptosis and cause inflammation in the liver. High temperature induced ovarian dysfunction, which resulted in the decline of hierarchical follicle number and weight, egg weight, and chick birth weight. The increased level of 17 beta-estradiol suggests liver damage. Protecting liver function from damage may assist in summer.
2020年09月, 研究論文（学術雑誌）, 共同, 99, 9, DOI(公開)(r-map), 4586, 4597 - Analysis of infant microbiota composition and the relationship with breast milk components in the Asian elephant (Elephas maximus) at the zoo
Kambe, Jun; Sasaki, Yu; Inoue, Ryo; Tomonaga, Shozo; Kinjo, Teruo; Watanabe, Gen; Jin, Wanzhu; Nagaoka, Kentaro
JOURNAL OF VETERINARY MEDICAL SCIENCE
JAPAN SOC VET SCI
The prevention of diseases through health control is essential at zoos. Here, we investigated the gut microbiota formation during infancy in an Asian elephant and compared the composition between infant and mother. Besides, we analyzed the components of breast milk and examined the correlation with the infant gut microbiota. Analysis revealed the gut microbiota of the infant contained high amount of Lactobacillales and its diversity was relatively low compared to that of the mother. We found several milk components, showed a positive correlation with the change of Lactobacillales. The present study revealed the mechanism of gut microbiota formation during infancy in an Asian elephant and provides important insights into the health control of Asian elephants in zoos.
2020年07月, 研究論文（学術雑誌）, 共同, 82, 7, 0916-7250, DOI(公開)(r-map), 983, 989 - Passive immunization against inhibin increases testicular blood flow in male goats
Samir, Haney; El Sayed, Mohamed A. I.; Nagaoka, Kentaro; Sasaki, Kazuaki; Abo El-Maaty, Amal M.; Karen, Aly; Abou-Ahmed, Mostafa M.; Watanabe, Gen
THERIOGENOLOGY
ELSEVIER SCIENCE INC
The present study investigated whether or not passive immunization against inhibin modulates testicular blood flow in goats. Male Shiba goats were injected with either 10 ml of inhibin antiserum (INH group; n = 5) or 10 ml of normal castrated goat serum (NGS group; n = 4). Concentrations of FSH, LH, testosterone (T), and estradiol (E2) in the plasma were measured by radioimmunoassay. Blood flow within the supratesticular (STA) and marginal testicular arteries (MTA) were measured by color pulsed Doppler ultrasonography, and Doppler indices (resistive index; RI and pulsatility index; PI) were recorded. Results revealed significant increases in concentrations of FSH and E2 in the INH group compared to those in the NGS group (P < 0.05). Animals in the INH group had greater (P < 0.05) FSH concentrations than those in the NGS group in the period between 60 h and 144 h after treatment than at any other time. Estradiol concentrations were greater (P < 0.05) in the INH group than in the NGS group at 6 h (12.15 +/- 2.09 pg/ml vs 5.49 +/- 1.17 pg/mL), 12 h (8.27 +/- 1.29 pg/mL vs 3.05 +/- 0.38 pg/mL), and 36 h (935 +/- 1.31 pg/mL vs 5.09 +/- 0.46 pg/mL) after treatment than at any other time. Concentrations of LH and T did not significantly change between the two groups. Goats in the INH group had lesser (P < 0.05) RI of the STA than those in the NGS group and RI values were lesser at 24 h (0.37 +/- 0.031 vs 0.49 +/- 0.004) and 120 h (0.38 +/- 0.028 vs 0.55 +/- 0.048) after treatment than at any other time. Furthermore, values of RI and PI of the MTA were significantly lesser (P < 0.05) in the INH group compared to those in the control group at 48 h (RI of MTA: 0.21 +/- 0.014 vs 0.37 +/- 0.039; PI of MTA: 0.24 +/- 0.016 vs 0.46 +/- 0.058) after treatment than at any other time. In conclusion, passive immunization against inhibin has a stimulatory effect on testicular blood flow in goats by inducing decreases in the RI values of the STA and MTA. (C) 2020 Elsevier Inc. All rights reserved.
2020年04月15日, 研究論文（学術雑誌）, 共同, 147, 0093-691X, DOI(公開)(r-map), 85, 91 - Administration of melatonin improves testicular blood flow, circulating hormones, and semen quality in Shiba goats
Samir, Haney; Nyametease, Paul; Elbadawy, Mohamed; Nagaoka, Kentaro; Sasaki, Kazuaki; Watanabe, Gen
THERIOGENOLOGY
ELSEVIER SCIENCE INC
Despite the role of melatonin in the regulation of the sleep-wake cycle and seasonal-reproduction, the present study investigated, for the first time, the potential role of melatonin on testicular blood flow (TBF) in goats. Twelve sexually mature male Shiba goats were exposed to a single s.c. injection of either melatonin suspended in one ml of corn oil (melatonin group; 36 mg/goat; n = 5) or one ml of corn oil (control group; n = 7). Monitoring the changes in TBF was done one week before (W-1), at the time of injection (W0), and once a week for 8 weeks after injection using color-pulsed Doppler ultrasonography. Concentrations of FSH, LH, inhibin, testosterone (T), estradiol (E2), and insulin-like growth factor-1 (IGF-1) in plasma were determined by radioimmunoassay. Melatonin and nitric oxide (NO) concentrations were measured using enzyme immunoassay kits. Moreover, semen collection and evaluation of some sperm parameters were performed once a week. Results revealed decreases (P < 0.05) in the Doppler indices (resistive index, pulsatility index) of the testicular arteries from W2 till W6 in the melatonin group. FSH, LH, and inhibin concentrations did not change between the two groups, while T, E2, NO, and melatonin concentrations increased (P < 0.05) in the melatonin group compared to the control. Estradiol and NO concentrations increased (P < 0.05), coinciding with decreases in the values of Doppler indices. Notable (P < 0.05) improvements in most parameters of semen quality were seen in the melatonin group. In conclusion, melatonin induced a stimulatory effect on TBF in Shiba goats and possibly, it could be a potential to improve male goats fertility. (C) 2020 Elsevier Inc. All rights reserved.
2020年04月01日, 研究論文（学術雑誌）, 共同, 146, 0093-691X, DOI(公開)(r-map), 111, 119 - Heat-killed Enterococcus fecalis (EC-12) supplement alters the expression of neurotransmitter receptor genes in the prefrontal cortex and alleviates anxiety-like behavior in mice
Kambe, Jun; Watcharin, Sovijit; Makioka-Itaya, Yuko; Inoue, Ryo; Watanabe, Gen; Yamaguchi, Hirohito; Nagaoka, Kentaro
NEUROSCIENCE LETTERS
ELSEVIER IRELAND LTD
Gut microbiota plays a crucial role in the maintenance of mental health and influences mental disorders such as depression and anxiety. Several studies have reported the beneficial affects of probiotics in mental health. Heat-killed Enterococcus faecalis strain EC-12 (EC-12), a lactic acid bacterium induces activation of the immune system. However, little is known about the effect of EC-12 on mental health. In the present study, the anti-anxiety effect of EC-12 was elucidated in vivo. Male mice fed on diet supplemented with EC-12 showed decreased anxiety-like behavior in open-field and elevated plus-mazetest. In addition, EC-12 supplementation exhibited an anti-depressive trend in mice subjected to forced swim test. The expression of neurotransmitter receptor genes: Adrb3 and Avpr1a were significantly enhanced in EC-12 supplemented mice compared to that of the control mice. In mice, analyses of gut microbiota composition by next generation sequencing revealed significant increase in Butyricicoccus and Enterococcus with EC-12 supplementation. Significant difference was not detected in the expression of neurotransmitter receptor genes in the prefrontal cortex with the administration of sodium butyrate compared to that of the control group. The mechanism associated with EC-12 mediated reduced anxiety-like behavior and altered gene expression in the brain needs to be further elucidated. Taken together, the present study is the first to report the possibility of exploiting the anti-anxiety effect of heat-killed EC-12 as a novel probiotic to promote mental health.
2020年02月16日, 研究論文（学術雑誌）, 共同, 720, 0304-3940, DOI(公開)(r-map) - Comparison of the fecal microbiota of two monogastric herbivorous and five omnivorous mammals
Kobayashi, Rana; Nagaoka, Kentaro; Nishimura, Naomichi; Koike, Satoshi; Takahashi, Eiki; Niimi, Kimie; Murase, Harutaka; Kinjo, Teruo; Tsukahara, Takamitsu; Inoue, Ryo
ANIMAL SCIENCE JOURNAL
WILEY
Fecal microbiota in seven different monogastric animal species, elephant, horse, human, marmoset, mouse, pig and, rat were compared using the same analytical protocol of 16S rRNA metagenome. Fecal microbiota in herbivores showed higher alpha diversity than omnivores except for pigs. Additionally, principal coordinate analysis based on weighted UniFrac distance demonstrated that herbivores and pigs clustered together, whereas other animal species were separately aggregated. In view of butyrate- and lactate-producing bacteria, predominant genera were different depending on animal species. For example, the abundance of Faecalibacterium, a known butyrate producer, was 8.02% +/- 3.22% in human while it was less than 1% in other animal species. Additionally, Bifidobacterium was a predominant lactate producer in human and marmoset, while it was rarely detected in other omnivores. The abundance of lactate-producing bacteria in herbivores was notably lower than omnivores. On the other hand, herbivores as well as pig possess Fibrobacter, a cellulolytic bacterium. This study demonstrated that fecal microbiota in herbivorous animals is similar, sharing some common features such as higher alpha diversity and higher abundance of cellulolytic bacterium. On the other hand, omnivorous animals seem to possess unique fecal microbiota. It is of interest that pigs, although omnivore, have fecal microbiota showing some common features with herbivores.
2020年01月, 研究論文（学術雑誌）, 共同, 91, 1, 1344-3941, DOI(公開)(r-map) - Effects of a selective casein kinase 1 delta and epsilon inhibitor on Fc epsilon RI expression and IgE-mediated immediate-type cutaneous reactions in dogs
Ohno, Hikaru; Takahashi, Kaho; Yanuma, Nanako; Ogawa, Misato; Hasegawa, Ayana; Sugita, Koji; Kawano, Koji; Sasaki, Kazuaki; Shirai, Junsuke; Nagaoka, Kentaro; Ohmori, Keitaro
JOURNAL OF VETERINARY MEDICAL SCIENCE
JAPAN SOC VET SCI
The molecular clock network in mast cells has been shown to be a factor responsible for circadian regulation of allergic inflammation. PF670462 is a selective inhibitor of casein kinase 1 delta and epsilon (CK1 delta/epsilon) that control the posttranslational modification of clock proteins. The aims of this study were to evaluate the effects of PF670462 on gene and protein expression of Fc epsilon RI, the high-affinity IgE receptor, in canine mast cells and on IgE-mediated immediate-type cutaneous reactions in dogs. PF670462 decreased mRNA expression of Fc epsilon RI alpha and beta, but not gamma, and protein expression of Fc epsilon RI in a canine mast cell line. Furthermore, PF670462 suppressed IgE-mediated immediate-type cutaneous erythema in dogs. These findings indicate that CK1 delta/epsilon function as regulators for Fc epsilon RI expression and IgE-mediated cutaneous reactions in dogs.
2019年11月, 研究論文（学術雑誌）, 共同, 81, 11, 0916-7250, DOI(公開)(r-map), 1680, 1684 - Yolk immunoreactive corticosterone in hierarchical follicles of Japanese quail (Coturnix japonica) exposed to heat challenge
Pu, Shaoxia; Nagaoka, Kentaro; Watanabe, Gen
GENERAL AND COMPARATIVE ENDOCRINOLOGY
ACADEMIC PRESS INC ELSEVIER SCIENCE
High temperature decreases the egg number, ovarian weight, and hierarchical follicle number. In the present study, we investigated the effect of high temperature on the quality of eggs of adult female quails. Laying quail were raised under a standard thermal condition of 25 degrees C until exposed to an elevated temperature of 34 degrees C (experimental) or maintained at 25 degrees C (control) from 12:00 to 16:00 for 10 consecutive days. Weight and number of eggs were measured; serum and the largest follicles were collected and used for hormone measurement. Ovaries and adrenals were collected for expression analysis of 3 beta- and 17 beta-HSD, genes encoding steroidogenic enzymes. Egg weight slightly decreased with an increase in the treatment time in the heat-challenged group; the egg weight significantly decreased in the heat treatment group than in the control group during the last 2 days of experiment (P < 0.05). The laying rate showed no difference during the experimental period but significantly decreased on the last day in the heat treatment group. In the experimental group the ovaries and oviducts were lighter (P < 0.05) and the hierarchical follicle number and ovarian weight decreased (P < 0.05) compared to the control group. Although serum corticosterone level significantly increased after heat challenge (P < 0.05) and immediately recovered to the normal level, yolk immunoreactive corticosterone in the hierarchical follicle (F1, F2, F3) significantly increased (P < 0.05). The expression level of 17 beta-HSD showed no changes in the ovary but significantly increased in adrenals (P < 0.05). Our findings indicate that the effects of heat challenge on the maternal ovary in the quail are mediated through the adrenal function.
2019年08月01日, 研究論文（学術雑誌）, 共同, 279, 0016-6480, DOI(公開)(r-map), 148, 153 - Fluvastatin Sodium Ameliorates Obesity through Brown Fat Activation
Yin, Na; Zhang, Hanlin; Ye, Rongcai; Dong, Meng; Lin, Jun; Zhou, Huiqiao; Huang, Yuanyuan; Chen, Li; Jiang, Xiaoxiao; Nagaoka, Kentaro; Zhang, Chuanhai; Jin, Wanzhu
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
MDPI
Brown adipose tissue (BAT), an organ that burns energy through uncoupling thermogenesis, is a promising therapeutic target for obesity. However, there are still no safe anti-obesity drugs that target BAT in the market. In the current study, we performed large scale screening of 636 compounds which were approved by Food and Drug Administration (FDA) to find drugs that could significantly increase uncoupling protein 1 (UCP1) mRNA expression by real-time PCR. Among those UCP1 activators, most of them were antibiotics or carcinogenic compounds. We paid particular attention to fluvastatin sodium (FS), because as an inhibitor of the cellular hydroxymethyl glutaryl coenzyme A (HMG-CoA) reductase, FS has already been approved for treatment of hypercholesteremia. We found that in the cellular levels, FS treatment significantly increased UCP1 expression and BAT activity in human brown adipocytes. Consistently, the expression of oxidative phosphorylation-related genes was significantly increased upon FS treatment without differences in adipogenic gene expression. Furthermore, FS treatment resisted to high-fat diet (HFD)-induced body weight gain by activating BAT in the mice model. In addition, administration of FS significantly increased energy expenditure, improved glucose homeostasis and ameliorated hepatic steatosis. Furthermore, we reveal that FS induced browning in subcutaneous white adipose tissue (sWAT) known to have a beneficial effect on energy metabolism. Taken together, our results clearly demonstrate that as an effective BAT activator, FS may have great potential for treatment of obesity and related metabolic disorders.
2019年04月01日, 研究論文（学術雑誌）, 共同, 20, 7, 1422-0067, DOI(公開)(r-map) - Gut microbiota development in mice is affected by hydrogen peroxide produced from amino acid metabolism during lactation
Shigeno, Yuko; Zhang, Haolin; Banno, Taihei; Usuda, Kento; Nochi, Tomonori; Inoue, Ryo; Watanabe, Gen; Jin, Wanzhu; Benno, Yoshimi; Nagaoka, Kentaro
FASEB JOURNAL
FEDERATION AMER SOC EXP BIOL
The development of gut microbiota during infancy is an important event that affects the health status of the host; however, the mechanism governing it is not fully understood. l-Amino acid oxidase 1 (LAO1) is a flavoprotein that catalyzes the oxidative deamination of particular l-amino acids and converts them into keto acids, ammonia, and H2O2. Our previous study showed that LAO1 is present in mouse milk and exerts protection against bacteria by its production of H2O2. The data led us to consider whether LAO1, H2O2, or both could impact infant gut microbiota development via mother's milk consumption in mice. Different gut microbiota profiles were observed in the wild-type (WT) and LAO1-knockout mouse pups. The WT pups' microbiota was relatively simple and composed of only a few dominant bacteria, such as Lactobacillus, whereas the lactating knockout pups had high microbiota diversity. Cross-fostering experiments indicated that WT milk (containing LAO1) has the ability to suppress the diversity of microbiota in pups. We observed that the stomach content of pups fed WT milk had LAO1 proteins and the ability to produce H2O2. Moreover, culture experiments showed that Lactobacillus was abundant in the feces of pups fed WT milk and that Lactobacillus was more resistant to H2O2 than Bifidobacterium and Escherichia. Human breast milk produces very little H2O2, which could be the reason for Lactobacillus not being dominant in the feces of breast-fed human infants. In mouse mother's milk, H2O2 is generated from the process of free amino acid metabolism, and H2O2 may be a key player in regulating the initial acquisition and development of gut microbiota, especially growth of Lactobacillus, during infancy.Shigeno, Y., Zhang, H., Banno, T., Usuda, K., Nochi, T., Inoue, R., Watanabe, G., Jin, W., Benno, Y., Nagaoka, K. Gut microbiota development in mice is affected by hydrogen peroxide produced from amino acid metabolism during lactation.
2019年03月, 研究論文（学術雑誌）, 共同, 33, 3, 0892-6638, DOI(公開)(r-map), 3343, 3352 - Pre-pubertal exposure to high temperature impairs ovarian and adrenal gland function in female rats
Zheng, Meihua; Nagaoka, Kentaro; Watanabe, Gen
JOURNAL OF VETERINARY MEDICAL SCIENCE
JAPAN SOC VET SCI
The influence of different levels of heat exposure on the functions of ovarian and adrenal gland were investigated in pre-puberty female rats. Three-week old female rats were treated with control (26 degrees C) or three higher temperatures (38, 40 and 42 degrees C) for 2hr/day. After 9 days of treatment, blood samples were collected for measurement of luteinizing hormone (LH), follicle stimulating hormone (FSH), estradiol-17 beta, corticosterone, cholesterol and triglyceride. Adrenal glands, ovaries and liver were collected for analyzing gene expressions. Body and liver weight were significantly low in the 42 degrees C heating group. Circulating LH and triglyceride in the 42 degrees C heating group were significantly lower, and estradiol-17 beta, corticosterone and cholesterol were significantly higher than those of the control group. The gene expression of 3 beta-HSD and P450c21 in the adrenal gland; 3 beta-HSD, receptors of LH, FSH and estrogen in the ovary were significantly low in heated rats. The liver gene expressions of caspase 3 and NK-.B were significantly high in 42 degrees C heated rats, suggesting that the ability of liver metabolic function reduced in the 42 degrees C heated rats. These results demonstrated that the high temperature is responsible for suppression of ovarian function by decreasing the expression of steroidogenic enzymes, estrogen and gonadotropin receptors in the ovary. Increase in circulating estradiol-17 beta in the heated rats may be due to accumulate this hormone in circulation by potential changes in liver metabolism during the heat stress.
2019年02月, 研究論文（学術雑誌）, 共同, 81, 2, 0916-7250, DOI(公開)(r-map), 279, 286 - Heat challenge influences serum metabolites concentrations and liver lipid metabolism in Japanese quail (Coturnix japonica)
Pu, Shaoxia; Usuda, Kento; Nagaoka, Kentaro; Watanabe, Gen
JOURNAL OF VETERINARY MEDICAL SCIENCE
JAPAN SOC VET SCI
High temperature induces various metabolic disturbances in animals. However, no comprehensive information is currently available on the metabolic pathway affected by high environmental temperature. The present study examined metabolite content in the serum of heat challenged quails using metabolomic analysis. In the present study, female quails with normal laying rate at 20 weeks kept in standard condition (control group) or exposed to 34 degrees C 4 hr per day (12:00 to 16:00 hr)(heat group) for 10 consecutive days. The metabolomic analysis identified 165 metabolites in the serum, and significant differences were observed in the serum for 7 metabolites between two groups. An analysis by Metabo Analyst, a web-based metabolome data tool, indicate that high temperature affect ketone body metabolism, butyrate metabolism, arginine and proline metabolism. Furthermore, histological examination of liver indicates a heat challenge induced abnormal lipid metabolism. Triglyceride and cholesterol level in the liver increased, however cholesterol level decreased in the serum. Genes related to lipid metabolism significantly increased in the liver after heat challenge. The present study demonstrated that high temperature cause liver damage, thus lipid metabolic was affected. Protect liver under high temperature could be one solution for coping with high temperatures in summer.
2019年01月, 研究論文（学術雑誌）, 共同, 81, 1, 0916-7250, DOI(公開)(r-map), 77, 83 - The potential role of YAP in Axl-mediated resistance to EGFR tyrosine kinase inhibitors
Saab, Sarah; Chang, Olin Shih-Shin; Nagaoka, Kentaro; Hung, Mien-Chie; Yamaguchi, Hirohito
AMERICAN JOURNAL OF CANCER RESEARCH
E-CENTURY PUBLISHING CORP
Yes-associated protein (YAP) is a transcription co-regulator downstream of the Hippo pathway, and plays a critical role in cancer. Although YAP regulation in the canonical Hippo pathway is well established, the Hippo-independent regulation of YAP is not well explored. Here, we showed the possible new mechanism of YAP regulation by the receptor tyrosine kinase Axl. Co-immunoprecipitation and Western blot analysis demonstrated the interaction between YAP and Axl, which was enhanced by Axl ligand Growth Arrest Specific 6 (GAS6) stimulation. Furthermore, we found that YAP is phosphorylated at tyrosine residues by GAS6 stimulation in vivo and Axl directly phosphorylates YAP in vitro. Axl overexpression or GAS6 stimulation increased YAP-mediated transcriptional activity, and YAP-mediated colony forming activity in soft agar was enhanced by co-expression of Axl. In EGFR tyrosine kinase inhibitor (TKI)-sensitive lung cancer cells, YAP protein was downregulated in response to TKI treatment, while overexpression of YAP attenuated TKI sensitivity, suggesting that YAP is a key determinant of TKI response. Moreover Axl overexpression reversed TKI-induced YAP downregulation and induced TKI-resistance, which was reversed by YAP knockdown, further supporting the notion that YAP functions downstream of Axl. Together, these findings suggest a novel role of YAP in Axl-mediated TKI resistance.
2019年, 研究論文（学術雑誌）, 共同, 9, 12, 2156-6976, DOI(公開)(r-map), 2719, 2729 - The stimulatory effect of subluteal progesterone environment on the superovulatory response of passive immunization against inhibin in goats
Samir, Haney; Nagaoka, Kentaro; Watanabe, Gen
THERIOGENOLOGY
ELSEVIER SCIENCE INC
The objective of the current study was to investigate the effect of subluteal progesterone environment on the efficacy of the ovarian responses in goats passively immunized against endogenous inhibin. Twelve cycling female Shiba goats were synchronized using two doses of prostaglandin F2 alpha 11 days apart. After detection of ovulation (DO, by ultrasonography), goats were randomly assigned into 2 groups: (1) Subluteal P4 group (SLP; n = 6), treated with a previously once-used controlled intravaginal progesterone releasing device (ou-CIDR) intravaginal from D 6 to D 12 concurrently with a luteolytic dose of PGF2 alpha at D6 (2) Normal Luteal P4 group (NLP; n = 6), had neither ou-CIDR nor PGF2 alpha. In both groups, goats were treated with an intravenous injection of 10 ml of inhibin antiserum at D10. After that, another luteolytic dose of PGF2 alpha was administrated to goats in both groups at D12, and withdrawal of ou-CIDR in the SLP group. Detection of estrous behavior was checked again 24 h following PGF2 alpha administration and or ou-CIDR withdrawal at 8 h intervals with a teaser buck. The follicle populations >= 4 mm in each goat were monitored through transrectal ultrasonography daily from 1 day after inhibin antiserum administration (0 h) and continued until ovulation had been detected (disappearance of large dominant follicles by ultrasonography). In addition, a repeated ultrasonographic scanning was performed 7 days after ovulation, and the ovulation rate had been estimated by counting the number of observed corpora lutea by ultrasonography. Blood samples were collected for measurement of plasma circulating inhibin binding activity, FSH, LH, estradiol (E2), and progesterone (P4) in both groups. Results revealed significant increases in maximum diameter of the preovulatory follicles (5.92 +/- 0.17 mm vs 5.31 +/- 0.26 mm; P < 0.05), and the mean maximum number of follicles >= 4 mm in diameter (18.45 +/- 3.40 vs 12.15 +/- 6.21; P < 0.05) in the SLP group compared with that of the NPL group. No significant differences were observed between both groups in term of inhibin binding activity %, and FSH. Following immunization, significant increases in the concentrations of circulating LH (at 72 h) and E2 (from 48 to 84 h) were noted in the SLP group as compared with the values obtained from the goats in the NLP group. Moreover, significant increases in ovulation rate (13.85 +/- 1.40 vs 5.67 +/- 2.10; P < 0.01) and subsequent P4 concentrations (from 192 to 288 h) were found in the SLP group as against those of the NLP group. In conclusion, maintaining a subluteal P4 environment concurrently with passive immunization against endogenous inhibin may improve the superovulatory response in female Shiba goats. (C) 2018 Elsevier Inc. All rights reserved.
2018年11月, 研究論文（学術雑誌）, 共同, 121, 0093-691X, DOI(公開)(r-map), 188, 195 - Effect of kisspeptin antagonist on goat in vitro Leydig cell steroidogenesis
Samir, Haney; Nagaoka, Kentaro; Watanabe, Gen
THERIOGENOLOGY
ELSEVIER SCIENCE INC
Kisspeptin is the protein product of Kiss/gene. In contrast to its fundamental role as GnRH Secretagogue and puberty initiation, its functions in extrahypothalmic tissues such as the testes remain unknown. The objective of this study was to investigate the potential local role of kisspeptin in the Leydig cell culture in goats. Five male Shiba goats were castrated to isolate Leydig cells from the testes. The isolated Leydig cells were then purified and cultured with different concentration of kisspeptin antagonist (0, 5, and 10 nmol; OKPA, 5KPA, and 10KPA; respectively). After 12 h, 20 IU of hCG was added to some wells (OKPA + hCG, 5KPA + hCG, and 10KPA + hCG; respectively); other wells did not receive hCG (OKPA + Con, 5KPA + Con, and 10KPA + Con; respectively). Media of Leydig cell culture was harvested at 2, 6,12, and 24 h after addition of hCG for testosterone (T) and estradiol (E2) assays. The contents of some non KPA treated wells (OKPA + Con and OKPA + hCG wells) were collected and stored at 80 degrees C for further identification the expression of mRNA encoding Kiss] and its receptor (GPR54) using real time PCR. Results revealed high expressions of Kiss1/GPR54 mRNAs in the hCG treated (OKPA + hCG) wells compared to non-hCG treated ones (OKPA + Con). KPA significantly reduced the basal T production at 6 h incubation as well as hCG-induced T production in 2, 6, and 24 h incubation. Basal E2 concentrations were significantly lower in the KPA treated wells at 6, and 24 h likewise, KPA significantly attenuated induced E2 production at 12 h compared with its values in non KPA treated wells. In conclusion, kisspeptin antagonist significantly attenuated both basal and hCG-activated T and E2 production by purified Leydig cells in goats. Therefore, involvement of kisspeptin in the steroidogenic capability of Leydig cells is possible in goats. (C) 2018 Elsevier Inc. All rights reserved.
2018年11月, 研究論文（学術雑誌）, 共同, 121, 0093-691X, DOI(公開)(r-map), 134, 140 - Effect of of seasonality on testicular blood flow as determined by color Doppler ultrasonography and hormonal profiles in Shiba goats
Samir, Haney; Nyametease, Paul; Nagaoka, Kentaro; Watanabe, Gen
ANIMAL REPRODUCTION SCIENCE
ELSEVIER SCIENCE BV
The objectives of this study were to determine if there is a seasonal pattern of testicular blood flow in male Shiba goats, and ascertaining whether or not there is a relationship among changes in testicular hemodynamics and circulating testosterone (T) and estradiol (E2). Twelve sexually mature male Shiba goats (Capra hircus), aged 19.5 +/- 2.5 months were used in this study. Monitoring of the changes in testicular blood flow was performed once a week for 1 year, using color spectral Doppler ultrasonography. Plasma concentrations of testosterone (T) and estradiol (E2) were determined by radioimmunoassay. Among the four seasons, the greatest increases (P <= 0. 001) in the values for the resistive index (RI) and pulsatility index (PI) of the testicular artery were recorded in the summer. Also, PI and RI values recorded in spring were greater than those recorded in autumn, while for winter there were the least values for these indices. Likewise, concentrations of T and E2 showed seasonal changes. Concentrations of T and E2 were greater during the autumn and winter compared to those in spring and summer. Interestingly, E2 concentrations were negatively associated with Doppler indices of the testicular artery. In conclusion, although Shiba goats are considered to be non-seasonal breeding animals, there were distinct seasonal patterns of testicular blood flow as measured by color Doppler ultrasonography, especially in Doppler indices. These changes were coincident with the changes in the circulating E2 and may be attributable to the seasonal changes in ambient temperature or daylight length.
2018年10月, 研究論文（学術雑誌）, 共同, 197, 0378-4320, DOI(公開)(r-map), 185, 192 - Characterization of membrane penetration and cytotoxicity of C9orf72-encoding arginine-rich dipeptides
Kanekura, Kohsuke; Harada, Yuichiro; Fujimoto, Mao; Yagi, Takuya; Hayamizu, Yuhei; Nagaoka, Kentaro; Kuroda, Masahiko
SCIENTIFIC REPORTS
NATURE PUBLISHING GROUP
Cell-penetrating peptides (CPPs) including arginine-rich peptides are attracting a lot of attention due to their potential as a novel intracellular drug delivery tool without substantial toxicity. On the other hand, disease-associated arginine-rich CPPs, such as poly-PR and poly-GR translated from C9orf72 gene, also efficiently enter neuronal cells and then kill them. Although both non-harmful CPPs and harmful poly-PR/GR penetrate the plasma membrane using same arginine residues, little is known about the factors which determine the toxicity of the pathogenic CPPs. Here, we show that poly-PR and poly-GR, but not other Arg-rich CPPs, specifically distributed to nucleolus via interaction with RNA. Importantly, C9orf72-dipeptides, but not other Arg-rich CPPs, caused inhibition of protein translation and cell death. Raising extracellular pH enhanced the cell penetration of poly-PR. The repeat number of (PR) affected the secondary structure and determined the intracellular delivery rate and neurotoxicity, and enforced intracellular delivery of non-penetrating short poly-PR peptide caused cell death, suggesting that modulation of extracellular environment to inhibit the uptake of Arg-rich dipeptides might be a drug target against poly-PR/GR-mediated neurotoxicity.
2018年08月24日, 研究論文（学術雑誌）, 共同, 8, 2045-2322, DOI(公開)(r-map) - Hippocampal metabolism of amino acids by L-amino acid oxidase is involved in fear learning and memory
Usuda, Kento; Kawase, Takahiro; Shigeno, Yuko; Fukuzawa, Susumu; Fujii, Kazuki; Zhang, Haolin; Tsukahara, Takamitsu; Tomonaga, Shozo; Watanabe, Gen; Jin, Wanzhu; Nagaoka, Kentaro
SCIENTIFIC REPORTS
NATURE PUBLISHING GROUP
Amino acids participate directly and indirectly in many important biochemical functions in the brain. We focused on one amino acid metabolic enzyme, L-amino acid oxidase (LAO), and investigated the importance of LAO in brain function using LAO1 knockout (KO) mice. Compared to wild-type mice, LAO1 KO mice exhibited impaired fear learning and memory function in a passive avoidance test. This impairment in LAO1 KO mice coincided with significantly reduced hippocampal acetylcholine levels compared to wild-type mice, while treatment with donepezil, a reversible acetylcholine esterase inhibitor, inhibited this reduction. Metabolomic analysis revealed that knocking out LAO1 affected amino acid metabolism (mainly of phenylalanine [Phe]) in the hippocampus. Specifically, Phe levels were elevated in LAO1 KO mice, while phenylpyruvic acid (metabolite of Phe produced largely by LAO) levels were reduced. Moreover, knocking out LAO1 decreased hippocampal mRNA levels of pyruvate kinase, the enzymatic activity of which is known to be inhibited by Phe. Based on our findings, we propose that LAO1 KO mice exhibited impaired fear learning and memory owing to low hippocampal acetylcholine levels. Furthermore, we speculate that hippocampal Phe metabolism is an important physiological mechanism related to glycolysis and may underlie cognitive impairments, including those observed in Alzheimer's disease.
2018年07月23日, 研究論文（学術雑誌）, 共同, 8, 2045-2322, DOI(公開)(r-map) - Accumulation of steroid hormones in the eggshells of Japanese quail (Coturnix coturnix japonica)
Qasimi, Mohammad Ibrahim; Mohibbi, Hadi; Nagaoka, Kentaro; Watanabe, Gen
GENERAL AND COMPARATIVE ENDOCRINOLOGY
ACADEMIC PRESS INC ELSEVIER SCIENCE
Oviparous mother transfer significant amounts of steroid to egg yolk during oviposition and the amounts may vary throughout the embryonic development. Eggshell may contain steroid hormones and the amounts could be different during embryonic development inside the egg. This study was designed to quantify the steroid concentrations in the eggshells of Japanese quail. We hypothesized that the steroids would be accumulated in the eggshells in a sex-dependent manner. Eggshells were obtained from three different stages (after laying, 15 days of incubation, and after hatching). The internal contents of the shells were carefully removed, completely dried and pulverized. The steroid contents of the eggshells were then measured by RIA. Physiologic variations in steroids were analyzed according to the amounts accumulated in the eggshells with the different embryonic stages. Results indicate that eggshell testosterone concentrations were high after laying. However, the concentrations were decreased during embryonic development and hatching and no difference was found in eggshell testosterone levels between male and female. However, eggshell estradiol concentrations were undetectable at laying time and the amounts were significantly increased at 15 days of incubation and slightly after hatching. Eggshell estradiol levels were significantly high in female eggshells than male during embryonic development. In contrast, eggshell corticosterone levels were significantly higher in males than in females after hatching. These results clearly demonstrated that eggshells accumulated steroid hormones, and the amounts varied during embryonic development concomitant with changes the internal contents of the eggs. (C) 2017 Elsevier Inc. All rights reserved.
2018年04月01日, 研究論文（学術雑誌）, 共同, 259, 0016-6480, DOI(公開)(r-map), 161, 164 - Effects of Phytosterols as Food Additives on Adrenal and Reproductive Endocrine Function during Sexual Maturation in Male Japanese Quail (Coturnix coturnix japonica)
Qasimi, Mohammad, I; Mohibbi, Hadi; Nagaoka, Kentaro; Watanabe, Gen
JOURNAL OF POULTRY SCIENCE
JAPAN POULTRY SCIENCE ASSOC
Varying amounts of phytosterols (PS) occur naturally in several foods of plant origin. PS, which are structurally and functionally similar to cholesterol, have been shown to reduce plasma total cholesterol (TC) and low-density lipoprotein-cholesterol (LDL-C) levels. Moreover, PS disrupts endocrine function in certain animals. In the present study, we investigated the effects of high doses of PS on adrenal and reproductive endocrine function during sexual maturation in Japanese male quails. Two experiments were conducted; in the first experiment, quail chicks were subjected to long-term chronic feeding of PS (8, 80, and 800 mg/kg body weight [BW]) and the chemicals were gavaged into the crop sac from 7-50 days post-hatching. From the forty-fourth day, half of the animals in each group were subjected to a 6-day adrenocorticotropic hormone (ACTH) challenge for artificial stimulation of the adrenal gland and evaluation of long-term PS effects; in the second experiment, single doses of PS were subcutaneously injected (SC) into adult males (10-weeks-old) to assess the acute direct effect. Results indicated that chronically PS-fed animals showed a better adrenal response to ACTH challenge, and the corticosterone levels were higher (P<0.05) than those of the controls. Moreover, corticosterone levels were also high (P<0.05) 3 h after SC injection of PS. In contrast, testosterone levels and the testes weights were significantly lower (P<0.05) in the groups chronically administered with PS. No differences were observed in the testosterone levels in the acute experiment or luteinizing hormone (LH) levels in either experiment. In conclusion, the differential effects of PS on the adrenal gland and testis might be due to preferential use of different lipoprotein-cholesterol forms for steroid production. In addition, PS might locally perturb testosterone production by its accumulation or delay in testicular maturation.
2018年04月, 研究論文（学術雑誌）, 共同, 55, 2, 1346-7395, DOI(公開)(r-map), 155, 161 - Effects of non-purified and semi-purified commercial diets on behaviors, plasma corticosterone levels, and cecum microbiome in C57BL/6J mice
Toyoda, Atsushi; Shimonishi, Hikari; Sato, Mizuho; Usuda, Kento; Ohsawa, Natsuki; Nagaoka, Kentaro
NEUROSCIENCE LETTERS
ELSEVIER IRELAND LTD
Diverse commercially available feeds are used in animal studies according to the purpose of the studies. We sought to understand the relationship between feed ingredients and their effects on animal physiology and behaviors. Here, we investigated how male laboratory mice (C57B1/6J (”B6”) mice) were affected by chronic feeding with two commercially available diets, a non-purified diet (MF) and a semi-purified diet (AIN-93G). In B6 mice, both diets similarly induced spontaneous activities in the home cage and the open field box, anxiety in the elevated plus maze test, and depressive-like behaviors in tail-suspension and forced-swimming tests, and with both diets, similar data were obtained on calorie intake, water intake, body weight gain, and plasma corticosterone levels. By contrast, liver weight was significantly higher in MF-fed B6 mice than in AIN-93G-fed B6 mice. Furthermore, the cecum microbiome was drastically affected by the diets, and, specifically, Allobaculum was the major genus (43.4%) in the cecum microbiota of AIN-93G-fed mice but its abundance was reduced (to 3.8%) in the case of MF-fed mice. Future studies should address whether the differences in diet purity and cecum microbiota influence brain functions and behaviors in B6 mice.
2018年03月23日, 研究論文（学術雑誌）, 共同, 670, 0304-3940, DOI(公開)(r-map), 36, 40 - Immunohistochemical localization of inhibin/activin subunits in adult Asian elephant (Elephas maximus) testes
Chaichanathong, Sirinart; Taya, Kazuyoshi; Watanabe, Gen; Nagaoka, Kentaro; Wajjwalku, Worawidh; Sudsukh, Apichaya; Thongtip, Nikorn
JOURNAL OF VETERINARY MEDICAL SCIENCE
JAPAN SOC VET SCI
Immunolocalization of inhibin-alpha and inhibin/activin beta A and beta B subunits in the testes of Asian elephant was determined. Testicular sections were immunostained with polyclonal antisera against inhibin subunit-alpha and inhibin/activin beta A and beta B using the avidin-biotinperoxidase complex method. Positive immunostaining against inhibin-alpha subunit was strongly present in Sertoli cells, and positive immunostaining for the inhibin/alpha activin beta A and beta B subunits was observed in both Sertoli and Leydig cells. These results indicated that while Sertoli cells are the predominant source of inhibin and activin secretions in the testes of adult male Asian elephant, Leydig cells are a source of activin but not inhibin.
2018年03月, 研究論文（学術雑誌）, 共同, 80, 3, 0916-7250, DOI(公開)(r-map), 549, 552 - Feeding of phytosterols reduced testosterone production by modulating GnRH and GnIH expression in the brain and testes of male Japanese quail (Coturnix coturnix japonica)
Qasimi, M. I.; Nagaoka, K.; Watanabe, G.
POULTRY SCIENCE
OXFORD UNIV PRESS
Phytosterols (PS), or plant sterols used as cholesterol-lowering agents, have been shown to act as endocrine-disrupting chemicals in some laboratory animals. Moreover, dietary PS efficiently pass through the blood-brain barrier and accumulate in brain cell membranes. We asked whether the accumulation of PS affects reproduction through the hypothalamic-pituitary-gonadal axis. Thirty male quail chicks were randomly divided into 3 groups (control, 80 mg/kg BW, and 800 mg/kg BW), and daily single doses of PS or vehicle were gavaged into the crop sac from 15 to 100 d of age. At the end of the entire period, half of each group was injected intramuscularly with either 10 mu g of chicken gonadotropin-releasing hormone 1 (cGnRH-1) or phosphate-buffered saline solution (PBS) as the vehicle. Blood was collected before and 30 min after cGnRH-1 challenge by jugular venipuncture and decapitation, respectively. The results indicated that testosterone concentrations were low (P < 0.05) before (800 mg/kg BW) and after GnRH challenge in PS-treated quails compared with controls (P < 0.001). However, luteinizing hormone (LH) levels were not different among the groups before cGnRH1 challenge. In addition, PS-gavaged animals failed to manifest increased LH levels after cGnRH-1 injection (P < 0.01). The same trends were observed in pituitary LH levels at 800 mg/kg BW PS after cGnRH-1 injection (P < 0.05). Real-time PCR results revealed that PS (800 mg/kg BW) feeding reduced expression of GnRH-1 in the brain and testes compared to controls. However, gonadotropin-inhibitory hormone (GnIH) expression was significantly elevated before and after GnRH-1 challenges in the brain and testes. Collectively, these results suggest that brain-mediated effects of PS on gonadal function occurs via the induction of GnIH gene expression, and these indirect effects are less potent than direct effects.
2018年03月, 研究論文（学術雑誌）, 共同, 97, 3, 0032-5791, DOI(公開)(r-map), 1066, 1072 - Evaluation of the chemiluminescent enzyme immunoassay system for the measurement of testosterone in the serum and whole blood of stallions
Toishi, Yuko; Tsunoda, Nobuo; Nagata, Shun-ichi; Kirisawa, Rikio; Nagaoka, Kentaro; Watanabe, Gen; Yanagawa, Yojiro; Katagiri, Seiji; Taya, Kazuyoshi
JOURNAL OF REPRODUCTION AND DEVELOPMENT
SOCIETY REPRODUCTION & DEVELOPMENT-SRD
Testosterone (T) concentration is a useful indicator of reproductive function in male animals. However, T concentration is not usually measured in veterinary clinics, partly due to the unavailability of reliable and rapid assays for animal samples. In this study, a rapid chemiluminescent enzyme immunoassay system (CLEIA system) that was developed for the measurement of T concentration in humans use was validated for stallion blood samples. First, serum T concentrations were measured using the CLEIA system and compared with those measured by a fluoroimmunoassay that has been validated for use in stallions. The serum T concentrations measured by the two methods were highly correlated (r = 0.9865, n = 56). Second, to validate the use of whole blood as assay samples, T concentrations in whole blood and in the serum were measured by the CLEIA system. T concentrations in both samples were highly correlated (r = 0.9665, n = 64). Finally, to evaluate the practical value of the CLEIA system in clinical settings, T concentrations were measured in three stallions with reproductive abnormalities after the administration of human chorionic gonadotropin (hCG). Two stallions with small or absent testes in the scrotum showed an increase in T production in response to hCG administration and one stallion with seminoma did not. In conclusion, the CLEIA system was found to be a rapid and reliable tool for measuring T concentrations in stallions and may improve reproductive management in clinical settings and in breeding studs.
2018年02月, 研究論文（学術雑誌）, 共同, 64, 1, 0916-8818, DOI(公開)(r-map), 41, 47 - Intrauterine exosomes are required for bovine conceptus implantation
Kusama, Kazuya; Nakamura, Keigo; Bai, Rulan; Nagaoka, Kentaro; Sakurai, Toshihiro; Imakawa, Kazuhiko
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
ACADEMIC PRESS INC ELSEVIER SCIENCE
Exosomes, extracellular vesicles, are present in uterine flushing fluids (UFs), which are involved in conceptus-endometrial interactions during pen-implantation periods. Despite several studies on intrauterine exosomes conducted, the roles conceptus and endometrial exosomes play during pen implantation periods have not been well characterized. To investigate the effect of bovine intrauterine exosomes on conceptus implantation, exosomes isolated from bovine UFs during peri-implantation periods were subjected to global protein analysis. The analysis detected 596 exosomal proteins, including ruminants' pregnancy recognition factor IFNT, and 172 differentially expressed proteins with more than 1.5-fold changes in UFs on days 17, 20 and 22 pregnancy (day of conceptus implantation is initiated on days 19-19.5). Treatment of primary bovine endometrial epithelial cells with exosomes from day 17 UFs up-regulated the expression of apoptosis-related genes, and treatment with exosomes from day 20 and 22 UFs up-regulated the expression of adhesion molecule. Based on these findings, intrauterine exosomes should be considered as an essential constituent for successful implantation. (C) 2017 Elsevier Inc. All rights reserved.
2018年01月01日, 研究論文（学術雑誌）, 共同, 495, 1, 0006-291X, DOI(公開)(r-map), 1370, 1375 - Different origins of two corpora lutea recovered from a pregnant African elephant (Loxodonta africana)
Yamamoto, Y.; Nagaoka, K.; Kamite, Y.; Watanabe, G.; Allen, T.; Stansfield, F.; Taya, K.
REPRODUCTION IN DOMESTIC ANIMALS
WILEY
Elephant ovaries contain multiple corpora lutea (CLs) throughout pregnancy. Two CLs (P-1 and P-2) collected from a pregnant African elephant were used to investigate their origin and physiological state in this study. The mRNA expressions of prolactin receptor, CYP11A and inhibin betaB subunit were higher in P-2 than in P-1, while LHCGR and inhibin betaA subunit mRNA were higher in P-1 than in P-2. Protein expression of cleaved caspase-3 was detected in P-1 but not in P-2. These results suggest different origins for the two CLs in this one pregnant elephant, and we also demonstrated the production of bioactive prolactin by the elephant placenta.
2017年12月, 研究論文（学術雑誌）, 共同, 52, 6, 0936-6768, DOI(公開)(r-map), 1138, 1141 - MicroRNA detection at femtomolar concentrations with isothermal amplification and a biological nanopore
Zhang, Haolin; Hiratani, Moe; Nagaoka, Kentaro; Kawano, Ryuji
NANOSCALE
ROYAL SOC CHEMISTRY
One of the greatest challenges faced by chemists and biologists is the detection of molecules at extremely low concentrations. This paper describes a method to detect ultra-low concentrations (1 femtomole) of nucleotides using isothermal amplification and a biological nanopore.
2017年11月, 研究論文（学術雑誌）, 共同, 9, 42, 2040-3364, DOI(公開)(r-map), 16124, 16127 - 4-Nitrophenol (PNP) inhibits the expression of estrogen receptor beta and disrupts steroidogenesis during the ovarian development in female rats
Zhang, Haolin; Taya, Kazuyoshi; Nagaoka, Kentaro; Yoshida, Midori; Watanabe, Gen
ENVIRONMENTAL POLLUTION
ELSEVIER SCI LTD
4-nitrophenol (PNP), isolated from diesel exhaust particles, has estrogenic and anti-androgenic activities, and affects the hypothalamus-pituitary-gonad axis in male rats. However, the effect of PNP on the reproduction of the female rats is still unknown. The aim of the study was to investigate the effect of neonatal PNP exposure on the ovarian function of female rats. The neonatal female rats were exposed to PNP (10 mg/kg, subcutaneously injection), the ovary and serum samples were collected at postnatal day (PND) 7, 14 and 21. The results showed that the ratio of primordial and primary follicles increased whereas the ratio of antral follicles decreased in the PNP treated ovaries at PND21. Even though no abnormality was observed in cyclicity, there was a significantly delayed timing of vaginal opening in PNP treated rats. The ovarian expression of steroidogenic enzymes including StAR, P450scc, P450c17 and P450arom increased at PND14 in the PNP treated rats compared with the control rats. In consistent with the gene expression, the concentration of estradiol-17 beta showed the similar pattern. However, PNP exposure failed to cause any significant change in the expression of steroidogenic enzymes in cultured neonatal ovaries. Furthermore, PNP suppressed the expression of estrogen receptor beta (ER beta), but not estrogen receptor alpha (ER alpha), in cultured ovaries or developmental ovaries. These results suggested that PNP might directly affect the expression of ER beta in the rat ovaries, resulting in the disrupted steroidogenesis during ovarian development and the delayed puberty. (C) 2017 Elsevier Ltd. All rights reserved.
2017年10月, 研究論文（学術雑誌）, 共同, 229, 0269-7491, DOI(公開)(r-map), 1, 9 - Comparison of physical body growth and metabolic and reproductive endocrine functions between north and south climates of Japan in trained Thoroughbred yearling horses
Tangyuenyong S, Sato F, Nambo Y, Murase H, Endo Y, Tanaka T, Nagaoka K, Watanabe G
J Equine Sci
2017年10月, 研究論文（学術雑誌）, 共同, 28, 77, 86 - The effects of phytosterols on the sexual behavior and reproductive function in the Japanese quail (Coturnix coturnix japonica)
Qasimi, Mohammad Ibrahim; Nagaoka, Kentaro; Watanabe, Gen
POULTRY SCIENCE
OXFORD UNIV PRESS
Phytosterols (PS) are plant origin sterols naturally found in many foods and added as food additives. Since 1950, PS have attracted considerable attention due to their ability to lower serum cholesterol and inhibit cardiovascular disease (CVD). However, recent studies have found that PS act as endocrine-disrupting chemicals in laboratory animals. Therefore, this study was aimed at finding the mechanism(s) for PS effects on the sexual behaviors and reproductive functions in male Japanese quails (Coturnix coturnix japonica). At 15 d of age, 30 male Japanese quails were randomly assigned to 3 groups for the chronic in-vivo experiment. Animals were gavaged daily with single dose of PS suspension (PS dissolved in medium chain triglyceride [MCT]) into the crop sac from 15-100 d of age. Following maturation, a sexual behavior test, semen collection, and test of fertilization ability were performed. Blood was collected by cervical dislocation at 100 day of age for hormones analysis. To observe the direct effects of PS on the testis, interstitial cells of the normal testes were cultured for 24 h. Ovine-LH (O-LH) was used for half of each group to stimulate interstitial cells for testosterone production. The results showed that chronic doses of PS reduced (P < 0.01) mount and copulation behavior in male quails (primarily in the group receiving 800 mg/kg BW). Both acute in vitro and chronic in vivo experiments revealed a reduction in testosterone (P < 0.05) after PS treatments; concomitantly, Leydig cell numbers were also low (P < 0.05) at a dose of 800 mg/kg BW. Real-time PCR results showed lower expression of 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) at the same dose. The results suggested that feeding large amounts of PS reduced testosterone levels and sexual behavior by affecting Leydig cell proliferation, and cholesterol trafficking, 17 beta-HSD expression in the testes of male Japanese quail.
2017年09月, 研究論文（学術雑誌）, 共同, 96, 9, 0032-5791, DOI(公開)(r-map), 3436, 3444 - Sensitive radioimmunoassay of total thyroxine (T4) in horses using a simple extraction method
Tangyuenyong, Siriwan; Nambo, Yasuo; Nagaoka, Kentaro; Tanaka, Tomomi; Watanabe, Gen
JOURNAL OF VETERINARY MEDICAL SCIENCE
JAPAN SOC VET SCI
Most thyroid hormone determinations in animals are based on immunoassays adapted from those used to test human samples, which may not reflect the actual values of thyroid hormone in horses because of the presence of binding proteins. The aims of the present study were i) to establish a novel radioimmunoassay (RIA) using a more simple and convenient method to separate binding proteins for the measurement of total thyroxine (T4) in horses and ii) to validate the assay by comparing total T4 concentrations in yearling horses raised in different climates. Blood samples were collected from trained yearlings in Hokkaido (temperate climate) and Miyazaki (subtropical climate) in Japan and from adult horses in estrus and diestrus. T4 was extracted from both serum and plasma using modified acid ethanol cryo-precipitation and sodium acetate ethanol methods. Circulating total T4 concentrations were determined by RIA. T4 concentration by sodium acetate ethanol was appropriately detectable rather than sodium salicylate method and was the same as for acid ethanol method. Furthermore, this sodium acetate ethanol method required fewer extraction steps than the other methods. Circulating T4 concentrations in yearlings were 225.98 +/- 20.89 ng/ml, which was higher than the previous reference values. With respect to climate, T4 levels in Hokkaido yearlings tended to be higher than those in Miyazaki yearlings throughout the study period. These results indicated that this RIA protocol using a modified sodium acetate ethanol separation technique might be an appropriate tool for specific measurement of total T4 in horses.
2017年07月, 研究論文（学術雑誌）, 共同, 79, 7, 0916-7250, DOI(公開)(r-map), 1294, 1300 - Neonatal exposure to 17 alpha-ethynyl estradiol (EE) disrupts follicle development and reproductive hormone profiles in female rats
Zhang, Haolin; Taya, Kazuyoshi; Nagaoka, Kentaro; Yoshida, Midori; Watanabe, Gen
TOXICOLOGY LETTERS
ELSEVIER IRELAND LTD
Toxic effects induced by exposure to endocrine-disrupting chemicals during fetal and neonatal periods can be irreversible and exert effects throughout an animal's entire life. Our previous study showed that neonatal exposure to 17 alpha-ethynyl estradiol (EE) induced irregular estrous cycle in adults. To uncover the reason for the delayed effect after neonatal exposure to EE, reproductive parameters including ovarian weight, ovarian steroidogenesis, and hormonal profiles were investigated in developing female rats. Ovarian weight decreased at postnatal days (PND) 14 and 21 after neonatal exposure to EE. Ovarian histology at PND21 showed that the ratio of follicles with a diameter > 300 mu m decreased and the ratio of follicles with a diameter of 100-150 mu m increased in EE-treated ovaries, indicating that neonatal exposure to EE retarded follicular development. Moreover, the expression of P450arom increased at PND14 and the expressions of inhibin/activin subunits beta A and beta B decreased at PND21 in EE-treated ovaries. Consistent with the expression of P450arom, circulating levels of 17 beta-estradiol increased at PND14 in EE-treated animals. Furthermore, the circulating levels of luteinizing hormone (LH) also increased at PND14 in the treated animals. Although the expression of Kiss1 did not change in the anteroventral periventricular nucleus (AVPV) of the hypothalamus between controls and EE-treated rats, the expression of Kiss1 was reduced in the arcuate nucleus (ARC) of the hypothalamus at PND14. Based upon those results, we suggest that neonatal exposure to EE disrupted the system regulating the interactions between the reproductive hormones and follicle development in pre-pubertal rats, which may result in reproduction dysfunction in adulthood.
2017年07月, 研究論文（学術雑誌）, 共同, 276, 0378-4274, DOI(公開)(r-map), 92, 99 - Steroidogenic enzyme expression in estrogen production in the goat gastrointestinal (GI) tract and the effect of castration
Mohibbi, Hadi; Qasimi, Mohammad Ibrahim; Nagaoka, Kentaro; Watanabe, Gen
JOURNAL OF VETERINARY MEDICAL SCIENCE
JAPAN SOC VET SCI
Extragonadal tissues are known to produce estrogens. At these sites, the C19 precursor is important for aromatase expression for the production of estrogen. Aromatase expression is tissue-specific and is controlled by hormones. Recent studies have shown that rat gastric parietal cells expressed aromatase. Our first objective was to investigate steroidogenic enzyme expression in estrogen biosynthesis; the second objective was to investigate which site(s) of the GI tract expressed steroidogenic enzymes; and the third objective was to assess the effects of castration on steroidogenic enzyme expression. CYP19A1, 17 beta-HSD3, CYP17A1, 3 beta-HSD and P450scc were quantified in the GI tract by real-time PCR. CYP19A1 was detected mainly in the body and pyloric regions of the abomasum, while we detected weak expression of CYP19A1 in other parts of GI tract. In addition, the expression of 17 beta-HSD3 and CYP17A1 was detected in abomasum. 3 beta-HSD expression was observed in duodenum and jejunum, while P450scc was not detectable in any part of GI tract. Immunohistochemical results showed immunolocalization of aromatase in parietal cells. Aromatase expression was observed to increase after castration. Furthermore, immunohistochemical results demonstrated that parietal cells also produced luteinizing hormone receptor (LHR). These results indicate steroidogenic enzymes required for the biosynthesis of estrogen were expressed, and the abomasum appeared to be the responsible organ for estrogen biosynthesis in the goat GI tract. In addition, parietal cells were responsible for estrogen production and the expression of LHR. Castration increased aromatase expression in abomasum through LH mediation.
2017年07月, 研究論文（学術雑誌）, 共同, 79, 7, 0916-7250, DOI(公開)(r-map), 1253, 1260 - Study of testicular immunolocalization of inhibin subunits and epididymal histological structures among different antler status in rusa deer (Rusa timorensis)
Sudsukh, Apichaya; Taya, Kazuyoshi; Watanabe, Gen; Nagaoka, Kentaro; Wajjwalku, Worawidh; Thongtip, Nikorn
THAI JOURNAL OF VETERINARY MEDICINE
CHULALONGKORN UNIV
The number of rusa deer (Rusa timorensis) raising farms has highly increased in Thailand. Basic data on the reproduction of rusa deer are essential for improvement in deer farming reproduction and the assisted reproductive technologies (ARTs) of endangered deer species. This study aimed to determine the relation of antler changes to testicular and epididymis histological structure and cellular source of testicular inhibin subunits in rusa deer. Eighteen rusa deer testes and epididymis were collected from a slaughterhouse located in Kamphaeng Saen, Nakhon Pathom, Thailand. The male rusa deer used in this study were separated into three groups depending on antler stages (velvet, intermediate and hard antlers). Histological observations of the testes and epididymis were performed. The testes sections of three different antler stages were immunostained by polyclonal antisera raised against inhibin alpha, beta(A) and beta(B) subunits. Means (+/- SEM) of testicular weight and seminiferous tubule diameter in the hard antler group (76.25 +/- 9.80 g and 256.10 +/- 7.28 mu m) were significantly higher than those of the velvet antler group (40.86 +/- 7.41 g and 197.25 +/- 7.23 mu m) (p<0.05). The epididymis of the intermediate and hard antler groups was filled widely with numerous spermatozoa, which, in contrast, were sporadically observed in the velvet antler group. In addition, the inhibin a and inhibin beta(A) subunits were expressed in both Sertoli cells and Leydig cells while the inhibin beta(B) subunit was only expressed in Leydig cells. This study suggests that the rusa deer testes secrete inhibin in all antler stages. The present study also clearly demonstrates that rusa deer antler changes are related to testicular weight, seminiferous tubule diameter and epididymal spermatozoa, indicating that antler change is a useful indicator for testicular function in rusa deer.
2017年06月, 研究論文（学術雑誌）, 共同, 47, 2, 0125-6491, 155, 164 - Decrease of lactogenic hormones induce epithelial-mesenchymal transition via TGF beta 1 and arachidonic acid during mammary gland involution
Zhang, Haolin; Liu, Yuning; Weng, Ji; Usuda, Kento; Fujii, Kazuki; Watanabe, Gen; Nagaoka, Kentaro
JOURNAL OF REPRODUCTION AND DEVELOPMENT
SOCIETY REPRODUCTION & DEVELOPMENT-SRD
During mammary gland involution, the epithelial mesenchymal transition (EMT) process plays an important role in tissue remodelling and in the termination of milk production. Transforming growth factor beta (TGF beta) has been known as a central inducer to EMT and contributor to the mammary gland involution. However, the whole mechanism has accomplished the EMT process in mammary gland is still unclear. Here, we show that arachidonic acid, one of the major products in milk, is new player to control the EMT together with TGF beta during mammary gland involution. Firstly, we observed decrease in CDH1 (epithelial marker gene) expression and increases in VIM and TWIST1(mesenchymal marker genes), TGFB1, and PLCG2 (arachidonic acid synthesis gene) at involution. In epithelial cells culture experiments, depletion of lactogenic hormones to mimic the involution induced TGF beta 1 and PLCG2 expressions. Treatment with arachidonic acid in epithelial cells increased VIM and TWIST1 expressions without decrease of CDH1 expression, while TGF beta 1 decreased CDH1 and increased VIM and TWIST]; more importantly, TGF beta 1 induced the expression of PLCG2, but arachidonic acid did not induce the expression of TGFB1. Finally, arachidonic acid accelerated the TGF beta 1 increasing VIM and TWIST/expressions, meanwhile arachidonic acid synthase inhibitor partially blocked the TGF beta 1 increasing VIMand TWIST/expressions. In conclusion, TGE beta 1 stimulates arachidonic acid synthesis and the arachidonic acid has a function to postulate the EMT process together with TGF beta 1 during mammary gland involution.
2017年06月, 研究論文（学術雑誌）, 共同, 63, 3, 0916-8818, DOI(公開)(r-map), 325, 332 - Expression of uterine lipocalin 2 and its receptor during early- to mid-pregnancy period in mares
Haneda, Shingo; Nagaoka, Kentaro; Nambo, Yasuo; Kikuchi, Masato; Nakano, Yasuko; Li, Junyou; Matsui, Motozumi; Miyake, Yo-ichi; Imakawa, Kazuhiko
JOURNAL OF REPRODUCTION AND DEVELOPMENT
SOCIETY REPRODUCTION & DEVELOPMENT-SRD
From previous cDNA subtraction studies analyzing gene expression in equine endometrium, high lipocalin 2 (LCN2) mRNA expression was found in the gravid endometrium. In the uterus, LCN2 may transport hydrophobic molecules and siderophores with iron, or may form a complex with another protein, however, the expression of uterine LCN2 beyond day 20 of equine pregnancy and its receptor has not been characterized. To study the expression and potential roles of uterine LCN2 from pre-implantation to mid-gestation period, stage-specific endometrial samples were obtained from day 13 (day 0 = ovulation) cyclic and days 13, 19, 25, and 60 to 131 pregnant mares. Expression of LCN2 mRNA increased in day 19 gravid endometrium and was abundant from day 60 onward. The expression of LCN2 mRNA was localized to the glandular epithelium. LCN2 protein was detected in day 25 gravid endometrium and luminal fluid, and the protein was localized to the glandular epithelium and luminal cavity, whereas LCN2 receptor expression was found in luminal and glandular epithelium and trophectoderm throughout the experimental period. The presence of matrix metalloproteinase-9 (MMP9) was also examined because MMP9 is known to form a complex with LCN2. Although MMP9 and LCN2 were both found in luminal fluid from day 25 pregnant uterus, the complex of these proteins was not detected. Localization of the receptor in the trophectoderm suggests that endometrial LCN2 could play a role in carrying small substances from the mother to fetus in the equine species.
2017年04月, 研究論文（学術雑誌）, 共同, 63, 2, 0916-8818, DOI(公開)(r-map), 127, 133 - 4-Nitrophenol exposure alters the AhR signaling pathway and related gene expression in the rat liver
Li, Ruonan; Song, Meiyan; Li, Zhi; Li, Yansen; Watanabe, Gen; Nagaoka, Kentaro; Taya, Kazuyoshi; Li, Chunmei
JOURNAL OF APPLIED TOXICOLOGY
WILEY-BLACKWELL
4-Nitrophenol (PNP) is well known as an environmental endocrine disruptor. The aim of this study was to clarify the mechanism of PNP-induced liver damage and determine the regulatory involvement of the aryl hydrocarbon receptor (AhR) signaling pathway and associated gene expression. Immature male Wistar-Imamichi rats (28days old) were randomly divided into control and PNP groups, which consisted of 1- and 3-day exposure (1 DE and 3 DE, respectively) and 3-day exposure followed by 3-day recovery (3 DE+3 DR), groups. Each group was administered the vehicle or PNP (200mgkg(-1) body weight). The body and liver weight were significantly decreased in the 3 DE group. The mRNA expression levels of estrogen receptor- (ER), glutathione S-transferase (GST) and AhR exhibited a significant increase in the 1 DE group whereas, in contrast, that of cytochrome P450 (CYP) 1A1 decreased significantly in the 3 DE +3 DR group. AhR and CYP1A1 proteins were detected in the cytoplasm of hepatocytes of the 1 DE and 3 DE +3 DR groups whereas the ER protein was found in the hepatocyte nuclei of the 1 DE and 3 DE groups. The present study demonstrates that PNP activated the AhR signaling pathway and regulated related CYP1A1 and GST gene expression in the liver. Copyright (c) 2016 John Wiley & Sons, Ltd. 4-Nitrophenol (PNP) is an environmental endocrine disruptor. The aim of this study was to clarify the mechanism of PNP-induced liver damage. 28-day-old male Wistar-Imamichi rats were randomly divided into control (vehicle) and PNP (200 mgbody-(1) weight) groups, which consisted of 1- and 3-day exposure (1 DE and 3 DE, respectively) and 3-day exposure followed by 3-day recovery (3 DE + 3 DR), groups. The body and liver weight were significantly decreased in the 3 DE group. The mRNA expression levels of estrogen receptor- (ER), glutathione S-transferase (GST), and aryl hydrocarbon receptor (AhR) exhibited a significant increase in the 1 DE group while cytochrome P450 (CYP) 1A1 decreased significantly in the 3 DE +3 DR group. AhR and CYP1A1 proteins were detected in the cytoplasm of hepatocytes of the 1 DE and 3 DE +3 DR groups while the ER protein was found in the hepatocyte nuclei of the 1 DE and 3 DE groups. The present study demonstrates that PNP activated the AhR signaling pathway and regulated related CYP1A1 and GST gene expression in the liver.
2017年02月, 研究論文（学術雑誌）, 共同, 37, 2, 0260-437X, DOI(公開)(r-map), 150, 158 - Degradation of staphylococcal enterotoxin A by a Pseudomonas aeruginosa isolate from raw milk
Fujikawa, Hiroshi; Nagaoka, Kentaro; Arai, Katsuhiko
BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY
TAYLOR & FRANCIS LTD
Recently, we found that staphylococcal enterotoxin A (SEA)-producing Staphylococcus aureus strains produced SEA in raw milk with microbial contaminants at high temperatures like 40 degrees C only. Moreover, the concentration of SEA produced in raw milk gradually decreased after the peak. The reason(s) for SEA degradation in raw milk was studied in this study. Degradation of SEA spiked in raw milk was observed at 40 degrees C, but not at 25 degrees C. A Pseudomonas aeruginosa isolate from raw milk degraded SEA spiked in broth at 40 degrees C. A sample partially purified with a chromatographic method from culture supernatant of the isolate degraded SEA. Two main proteolytic bands were observed in the sample by zymographic analysis with casein. These results suggested that the SEA in raw milk might be degraded by a protease(s) produced by the P. aeruginosa isolate. This finding might be the first report on SEA degradation by a proteolytic enzyme(s) derived from Pseudomonas bacteria to our knowledge.
2017年, 研究論文（学術雑誌）, 共同, 81, 7, 0916-8451, DOI(公開)(r-map), 1436, 1443 - Effects of Daily Exposure to Saccharin and Sucrose on Testicular Biologic Functions in Mice
Gong T, Wei QW, Mao DG, Nagaoka K, Watanabe G, Taya K, Shi FX
Biol Reprod
2016年12月, 研究論文（学術雑誌）, 共同, 95, 116 - PATHFAST, a novel chemiluminescent enzyme immunoassay for measuring estradiol in equine whole blood and serum
Toishi Y, Tsunoda N, Kume K, Nagaoka K, Watanabe G, Taya K
J Reprod Dev
2016年12月, 研究論文（学術雑誌）, 共同, 62, 631, 634 - Estrogenic Compounds Impair Primordial Follicle Formation by Inhibiting the Expression of Proapoptotic Hrk in Neonatal Rat Ovary
Zhang H, Nagaoka K, Usuda K, Nozawa K, Taya K, Yoshida M, Watanabe G
Biol Reprod
2016年10月, 研究論文（学術雑誌）, 共同, 95, 78 - Effects of 4-nitrophenol on expression of the ER-α and AhR signaling pathway-associated genes in the small intestine of rats
Tang J, Song M, Watanabe G, Nagaoka K, Rui X, Li C
Environ Pollut
2016年09月, 研究論文（学術雑誌）, 共同, 216, 27, 37 - IMMUNOLOCALIZATION OF INHIBIN/ACTIVIN SUBUNITS AND STEROIDOGENIC ENZYMES IN THE TESTES OF AN ADULT AFRICAN ELEPHANT (LOXODONTA AFRICANA)
Li Q, Lu L, Weng Q, Kawakami S, Saito E, Yamamoto T, Yamamoto Y, Kaewmanee S, Nagaoka K, Watanabe G, Taya K
J Zoo Wildl Med
2016年06月, 研究論文（学術雑誌）, 共同, 47, 419, 422 - CPEB1 mediates epithelial-to-mesenchyme transition and breast cancer metastasis
Nagaoka K, Fujii K, Zhang H, Usuda K, Watanabe G, Ivshina M, Richter JD
Oncogene
2016年06月, 研究論文（学術雑誌）, 共同, 35, 2893, 2901 - Changes in bone mass during the perimenopausal transition in naturally menopausal cynomolgus monkeys
Kittivanichkul D, Watanabe G, Nagaoka K, Malaivijitnond S
Menopause
2016年01月, 研究論文（学術雑誌）, 共同, 23, 87, 99 - Promoting effects of an extended photoperiod treatment on the condition of hair coats and gonadal function in Thoroughbred weanlings
Harada T, Nambo Y, Ishimaru M, Sato F, Nagaoka K, Watanabe G, Taya K
J Equine Sci
2015年12月, 研究論文（学術雑誌）, 共同, 26, 147, 150 - Different effects of an extended photoperiod treatment on growth, gonadal function, and condition of hair coats in Thoroughbred yearlings reared under different climate conditions
Suzuki T, Mizukami H, Nambo Y, Ishimaru M, Miyata K, Akiyama K, Korosue K, Naito H, Nagaoka K, Watanabe G, Taya K
J Equine Sci
2015年12月, 研究論文（学術雑誌）, 共同, 26, 113, 124 - Long-term p-nitrophenol exposure can disturb liver metabolic cytochrome P450 genes together with aryl hydrocarbon receptor in Japanese quail
Ahmed E, Nagaoka K, Fayez M, Samir H, Watanabe G
Jpn J Vet Res
2015年12月, 研究論文（学術雑誌）, 共同, 63, 115, 127 - Social isolation prompts maternal behavior in sexually naïve male ddN mice
Orikasa C, Nagaoka K, Katsumata H, Sato M, Kondo Y, Minami S, Sakuma Y
Physiology and Behavior
2015年11月, 研究論文（学術雑誌）, 共同, 151, 9-15 - Lactogenic Hormone Stimulation and Epigenetic Control of L-Amino Acid Oxidase Expression in Lactating Mammary Glands
Fujii K, Zhang H, Usuda K, Watanabe G, Nagaoka K
Journal of Cellular Physiology
2015年11月, 研究論文（学術雑誌）, 共同, 230, 2755, 2762 - Effects of an extended photoperiod on gonadal function and condition of hair coats in Thoroughbred colts and fillies.
Kunii H, Nambo Y, Okano A, Matsui A, Ishimaru M, Asai Y, Sato F, Fujii K, Nagaoka K, Watanabe G, Taya K.
J Equine Sci
2015年10月, 研究論文（学術雑誌）, 共同, 26, 57, 66 - Comparison of growth and endocrine changes in Thoroughbred colts and fillies reared under different climate conditions.
Mizukami H, Suzuki T, Nambo Y, Ishimaru M, Naito H, Korosue K, Akiyama K, Miyata K, Yamanobe A, Nagaoka K, Watanabe G, Taya K
J Equine Sci.
2015年10月, 研究論文（学術雑誌）, 共同, 26, 49, 56 - Effect of a single injection of gonadotropin-releasing hormone (GnRH) and human chorionic gonadotropin (hCG) on testicular blood flow measured by color doppler ultrasonography in male Shiba goats
Samir H, Sasaki K, Ahmed E, Karen A, Nagaoka K, El Sayed M, Taya K, Watanabe G
Journal of Veterinary Medical Science
2015年03月, 研究論文（学術雑誌）, 共同, 77, 549, 556 - Embryonic sex steroid hormones accumulate in the eggshell of loggerhead sea turtle (Caretta caretta).
Kobayashi S, Saito Y, Osawa A, Katsumata E, Karaki I, Nagaoka K, Taya K, Watanabe G
Gen Comp Endocrinol.
2015年01月, 研究論文（学術雑誌）, 共同, S0016-6480, 162, 168 - Effects of thyroid hormones on the antioxidative status in the uterus of young adult rats.
Kong L, Wei Q, Fedail JS, Shi F, Nagaoka K, Watanabe G
J Reprod Dev.
2015年01月, 研究論文（学術雑誌）, 共同, 61, 219, 227 - Suppressive effects of long-term exposure to P-nitrophenol on gonadal development, hormonal profile with disruption of tissue integrity, and activation of caspase-3 in male Japanese quail (Coturnix japonica)
Ahmed E, Nagaoka K, Fayez M, Abdel-Daim MM, Samir H, Watanabe G
Environ Sci Pollut Res Int.
2015年01月, 研究論文（学術雑誌）, 共同, 22, 10930, 10942 - RNA-seq analysis of equine conceptus transcripts during embryo fixation and capsule disappearance
Tachibana Y, Sakurai T, Bai H, Shiota K, Nambo Y, Nagaoka K, Imakawa K
PLoS One
2014年12月, 研究論文（学術雑誌）, 共同, 9, e114414 - Low expression of the antibacterial factor L-amino acid oxidase in bovine mammary gland
Nagaoka K, Zhang H, Arakuni M, Taya K, Watanabe G
Animal Science Journal
2014年10月, 研究論文（学術雑誌）, 共同, 85, 976, 980 - Neonatal Exposure to 17α-Ethynyl Estradiol Affects Kisspeptin Expression and LH-Surge Level in Female Rats
Usuda K, Nagaoka K, Nozawa K, Zhang H, Taya K, Yoshida M, Watanabe G
Journal of Veterinary Medical Science
2014年05月, 研究論文（学術雑誌）, 共同, 76, 1105, 1110 - Neonatal exposure to 17α-ethynyl estradiol affects ovarian gene expression and disrupts reproductive cycles in female rats
Nozawa K, Nagaoka K, Zhang H, Usuda K, Okazaki S, Taya K, Yoshida M, Watanabe G
Reproductive Toxicology
2014年03月, 研究論文（学術雑誌）, 共同, 46C, 77, 84 - ウシ乳腺組織におけるL型アミノ酸オキシダーゼの発現解析
永岡謙太郎、張浩林、荒邦昌宏、渡辺元
第18回日本乳房炎研究会プロシーディング
2014年03月, 共同, -, 27, 29 - Genetic and acute CPEB1 depletion ameliorate fragile X pathophysiology
Udagawa T, Farny NG, Jakovcevski M, Kaphzan H, Alarcon JM, Anilkumar K, Ivshina M, Hurt JA, Nagaoka K, Nalavadi VC, Lorenz LJ, Bassell GJ, Akbarian S, Chattarji S, Klann E, Richter JD
Nature Medicine
2013年11月, 研究論文（学術雑誌）, 共同, 19, DOI(公開)(r-map), 1473, 1477 - Preventive effect of tert-butylhydroquinone on scrotal heat-induced damage in mouse testes
Li YS, Piao YG, Nagaoka K, Watanabe G, Taya K, Li CM
Genetics and Molecular Research
2013年10月, 研究論文（学術雑誌）, 共同, 12, 5433, 5441 - Epithelial cell differentiation regulated by MicroRNA-200a in mammary glands
Nagaoka K, Zhang H, Watanabe G, Taya K
PLoS One
2013年01月, 研究論文（学術雑誌）, 共同, 8, 6, DOI(公開)(r-map), e65127 - Molecular cloning and expression profile of a Halloween gene encoding Cyp307A1 from the seabuckthorn carpenterworm, Holcocerus hippophaecolus
Zhou J, Zhang H, Li J, Sheng X, Zong S, Luo Y, Nagaoka K, Weng Q, Watanabe G, Taya K
Journal of Insect Science
2013年01月, 研究論文（学術雑誌）, 共同, 13, DOI(公開)(r-map), 56 - Protective effects of nuclear factor erythroid 2-related factor 2 on whole body heat stress-induced oxidative damage in the mouse testis
Li Y, Huang Y, Piao Y, Nagaoka K, Watanabe G, Taya K, Li C
Reproductive Biology and Endocrinology
2013年01月, 研究論文（学術雑誌）, 共同, 11, DOI(公開)(r-map), 23 - Translational control of cell growth and malignancy by the CPEBs
D'Ambrogio A, Nagaoka K, Richter JD
Nature Review Cancer
2013年01月, 共同, - - Expression of Inhibin/Activin Subunits in the Equine Uteri during the Early Pregnancy
Zhang H, Nagaoka K, Imakawa K, Nambo Y, Watanabe G, Taya K, Weng Q
Reproduction in Domestic Animal
2013年01月, 研究論文（学術雑誌）, 共同, - - Effects of Exposure to Nanoparticle-Rich Diesel Exhaust on Pregnancy in Rats
Li C, Li X, Suzuki AK, Zhang Y, Fujitani Y, Nagaoka K, Watanabe G, Taya K
Journal of Reproduction and Development
2013年01月, 研究論文（学術雑誌）, 共同, - - Expression of Endometrial Immune-related Genes Possibly Functioning During Early Pregnancy in the Mare
Tachibana Y, Nakano Y, Nagaoka K, Kikuchi M, Nambo Y, Haneda S, Matsui M, Miyake YI, Imakawa K
Journal of Reproduction and Development
2013年01月, 研究論文（学術雑誌）, 共同, 59, 85, 91 - ミルク中L-amino acid oxidase (LAO)による乳腺感染防御機構
永岡謙太郎、渡辺元、田谷一善
第16回日本乳房炎研究会プロシーディング
2012年03月, 共同, -, 37, 40 - Effects of Sulfamethazine on Induction of Precocious Puberty in Japanese Quails (Coturnix japonica) Assessed through Monitoring the Hormonal Changes and Gonadal Development
Sedqyar M, Kandiel MM, Weng Q, Nagaoka K, Watanabe G, Taya K
Journal of Reproduction and Development
2012年01月, 研究論文（学術雑誌）, 共同, 58, 563, 568 - Circulating Pituitary and Gonadal Hormones in Spring-born Thoroughbred Fillies and Colts from Birth to Puberty
Dhakal P, Hirama A, Nambo Y, Harada T, Sato F, Nagaoka K, Watanabe G, Taya K
Journal of Reproduction and Development
2012年01月, 研究論文（学術雑誌）, 共同, 58, 522, 530 - Effects of pantothenic acid supplement on secretion of steroids by the adrenal cortex in female rats
Pan L, Jaroenporn S, Yamamoto T, Nagaoka K, Azumano I, Onda M, Watanabe G, Taya K
Reproductive Medicine and Biology
2012年01月, 研究論文（学術雑誌）, 共同, 11, 101, 104 - Effect of nanoparticle-rich diesel exhaust on testosterone biosynthesis in adult male mice.
Li C, Li X, Jigami J, Hasegawa C, Suzuki AK, Zhang Y, Fujitani Y, Nagaoka K, Watanabe G, Taya K
Inhalation toxicology
2012年01月, 研究論文（学術雑誌）, 共同, -, - - Pregnancy-associated plasma protein (PAPP)-A expressed in the mammary gland controls epithelial cell proliferation and differentiation
Nakasato M, Kohsaka H, Mizutani T, Watanabe G, Taya K, Nagaoka K
Endocrine
2012年01月, 研究論文（学術雑誌）, 共同, -, - - Effects of exposure to nanoparticle-rich diesel exhaust on adrenocortical function in adult male mice
Li C, Li X, Suzuki AK, Fujitani Y, Jigami J, Nagaoka K, Watanabe G, Taya K
Toxicology Letters
2012年01月, 研究論文（学術雑誌）, 共同, 209, 277, 281 - CPEB-mediated ZO-1 mRNA localization is required for epithelial tight-junction assembly and cell polarity
Nagaoka K, Udagawa T, Richter JD
Nature Communications
2012年01月, 研究論文（学術雑誌）, 共同, 3, 675 - Production of Calcium Maintenance Factor Stanniocalcin-1 (STC1) by the Equine Endometrium during Early Pregnant Period
Kikuchi M, Nakano Y, Nambo Y, Haneda S, Matsui M, Miyake Y, Macleod J, Nagaoka K, Imakawa K.
Journal of Reproduction and Development
2011年01月, 研究論文（学術雑誌）, 共同, 57, 203, 211 - Abundant expression of KCNE1 in the left ventricle of the miniature pig.
Soma K, Nagaoka K, Kuwahara M, Tsubone H, Ito K
Heart and Vessels
2011年01月, 研究論文（学術雑誌）, 共同, 26, 353, 356 - Secretion of inhibin during the estrous cycle in the female Asian elephant (Elephas maximus).
Kaewmanee S, Watanabe G, Kishimoto M, Jin WZ, Yamamoto Y, Yamamoto T, Nagaoka K, Narushima E, Komiya T, Taya K
Journal of Veterinary Medical Science
2011年01月, 研究論文（学術雑誌）, 共同, 73, 77, 82 - A surge-like increase in luteinizing hormone preceding musth in a captive bull African elephant (Loxodonta africana).
Kaewmanee S, Watanabe G, Keio M, Yamamoto Y, Yamamoto T, Kishimoto M, Nagaoka K, Narushima E, Katayanagi M, Nakao R, Sakurai Y, Morikubo S, Kaneko M, Yoshihara M, Yabe T, Taya K
Journal of Veterinary Medical Science
2011年01月, 研究論文（学術雑誌）, 共同, 73, 379, 383 - The Secretory Pattern and Source of Immunoreactive Prolactin in Pregnant African (Loxodonta africana) and Asian (Elephas maximus) Elephants
Yamamoto Y, Yamamoto T, Yuto N, Hildebrandt TB, Lueders I, Wibbelt G, Shiina O, Mouri Y, Sugimura K, Sakamoto S, Kaewmanee S, Nagaoka K, Watanabe G, Taya K
Journal of Reproduction and Development
2011年01月, 研究論文（学術雑誌）, 共同, 58, 105, 111 - Follicular turnover and hormonal association in postpartum goats during early and late lactation.
Kandiel MM, Watanabe G, Abou-El Roos MEA, Abdel-Ghaffar AE, Sosa GA, El-Azab AEI, Nagaoka K, Li JY, Manabe N & Taya K.
Journal of Reproduction and Development
2011年01月, 研究論文（学術雑誌）, 共同, 58, 61, 68 - Endocrine mechanisms responsible for different follicular development during the estrous cycle in Hatano high- and low-avoidance rats.
Jaroenporn S, Horii Y, Akieda-Asai S, Wang KM, Nagaoka K, Ohta R, Shirota M, Watanabe G & Taya K.
Journal of Reproduction and Development
2011年01月, 研究論文（学術雑誌）, 共同, 57, 690, 699 - Secretory pattern of inhibin during estrous cycle and pregnancy in African (Loxodonta africana) and Asian (Elephas maximus) elephants.
Yamamoto Y, Yuto N, Yamamoto T, Kaewmanee S, Shiina O, Mouri Y, Narushima E, Katayanagi M, Sugimura K, Nagaoka K, Watanabe G & Taya K.
Zoo Biology
2011年01月, 研究論文（学術雑誌）, 共同, 30, 1, 12 - Annual changes in day-length, temperature, and circulating reproductive hormones in thoroughbred stallions and geldings.
Dhakal P, Tsunoda N, Nakai R, Kitaura T, Harada T, Ito M, Nagaoka K, Toishi Y, Taniyama H, Watanabe G & Taya K.
Journal of Equine Science
2011年01月, 研究論文（学術雑誌）, 共同, 22, 2, 29, 36 - Post-natal dynamic changes in circulating follicle-stimulating hormone, luteinizing hormone, immunoreactive inhibin, progesterone, testosterone and estradiol-17β in throughbred colts until 6 months of age.
Dhakal P, Tsunoda N, Nakai R, Nagaoka K, Nambo Y, Sato F, Taniyama H, Watanabe G, & Taya K.
Journal of Equine Science
2011年01月, 研究論文（学術雑誌）, 共同, 22, 1, 9, 15 - Hydrogen peroxide produced by a low-molecular-weight compound in milk with high electrical conductivity in dairy cows
Sakai S, Satow T, Imakawa K, Nagaoka K.
Animal Science Journal
2010年01月, 研究論文（学術雑誌）, 共同, 81, 694, 698 - Differences in adrenocortical secretory and gene expression responses to stimulation in vitro by ACTH or prolactin between high and low avoidance Hatano rats
Jaroenporn S, Nagaoka K, Ohta R, Shirota M, Watanabe G, Taya K.
Stress
2009年01月, 研究論文（学術雑誌）, 共同, 12, 22, 29 - MiR-101a controls cell proliferation by regulating cyclooxygenase-2 during mammary gland development
Tanaka T, Imakawa K, Sakai S, Nagaoka K
Differentiation
2009年01月, 研究論文（学術雑誌）, 共同, 77, 181, 188 - Interleukin-1 receptor antagonist 1 expression in the equine endometrium during peri-implantation period
Haneda S, Nagaoka K, Nambo Y, Kikuchi M, Nakano Y, Matsui M, Miyake Y, Macleod JE, Imakawa K
Domestic Animal Endocrinology
2009年01月, 研究論文（学術雑誌）, 共同, 36, 209, 218 - Induction of endogenous tau interferon gene transcription by CDX2 and high acetylation in bovine non-trophoblast cells.
Sakurai T, Sakamoto A, Muroi Y, Bai H, Nagaoka K, Tamura K, Takahashi T, Hashizume K, Sakatani M, Takahashi M, Godkin JD, Imakawa K
Biology of Reproduction
2009年01月, 研究論文（学術雑誌）, 共同, 80, 1223, 1231 - Prolactin inducesphosphorylation of the STAT5 in adrenal glands of Hatano rats during stress
Jaroenporn S, Nagaoka K, Ohta R, Watanabe G, Taya K
Life Science
2009年01月, 研究論文（学術雑誌）, 共同, 85, 172, 177 - Involvement of GATA transcription factors in the regulation of endogenous bovine interferon-tau gene transcription
Bai H, Sakurai T, Kim MS, Muroi Y, Ideta A, Aoyagi Y, Nakajima H, Takahashi M, Nagaoka K, Imakawa K
Molecular Reproduction and Development
2009年01月, 研究論文（学術雑誌）, 共同, 76, 1143, 1152 - CD9 regulates transcription factor GCM1 and ERVWE1 expression through the cAMP/protein kinase A signaling pathway
Muroi Y, Sakurai T, Hanashi A, Kubota K, Nagaoka K, Imakawa K
Reproduction
2009年01月, 研究論文（学術雑誌）, 共同, 138, 945, 951 - L-amino acid oxidase plays a crucial role in host defense in the mammary glands
Nagaoka K, Aoki F, Hayashi M, Muroi Y, Sakurai T, Itoh K, Ikawa M, Okabe M, Imakawa K, Sakai S
FASEB Journal
2009年01月, 研究論文（学術雑誌）, 共同, 23, 2514, 2520 - Comparative effects of prolactin versus ACTH, estradiol, progesterone, testosterone, and dihydrotestosterone on cortisol release and proliferation of the adrenocortical carcinoma cell line H295R
Jaroenporn S, Furuta C, Nagaoka K, Watanabe G, Taya K
Endocrine
2008年01月, 研究論文（学術雑誌）, 共同, 33, 205, 209 - Generation of hydrogen peroxide by a low molecular weight compound in whey of Holstein dairy cows.
Sakai S, Satow T, Imakawa K, Nagaoka K
Journal of Dairy Research
2008年01月, 研究論文（学術雑誌）, 共同, 75, 257, 261 - Production of hydrogen peroxide by a small molecular mass compound in milk from Holstein cows with high and low milk somatic cell count.
Sakai S, Nonobe E, Satow T, Imakawa K, Nagaoka K
Journal of Dairy Research
2008年01月, 研究論文（学術雑誌）, 共同, 75, 335, 339 - Direct effects of prolactin on adrenal steroid release in male Hatano high-avoidance (HAA) rats may be mediated through Janus kinase 2 (Jak2) activity
Jaroenporn S, Nagaoka K, Ohta R, Watanabe G, Taya K
Journal of Reproduction and Development
2007年01月, 研究論文（学術雑誌）, 共同, 53, 887, 893 - Physiological roles of prolactin in the adrenocortical response to acute restraint stress
Jaroenporn S, Nagaoka K, Kasahara C, Ohta R, Watanabe G, Taya K
Endocrine Journal
2007年01月, 研究論文（学術雑誌）, 共同, 54, 703, 711 - Involvement of RNA binding proteins AUF1 in mammary gland differentiation
Nagaoka K, Tanaka T, Imakawa K, Sakai S
Experimental Cell Research
2007年01月, 研究論文（学術雑誌）, 共同, 313, 2937, 2945 - Regulation of conceptus adhesion by endometrial CXC chemokines during the implantation period in sheep
Imakawa K, Imai M, Sakai A, Suzuki M, Nagaoka K, Sakai S, Lee SR, Chang KT, Echternkamp SE, Christenson RK
Molecular Reproduction and Development
2006年01月, 研究論文（学術雑誌）, 共同, 73, 850, 858 - Stability of casein mRNA in ensured by structural interactions between the 3’-untranslated region and poly(A) tail via the HuR and poly(A)-binding protein complex
Nagaoka K, Suzuki T, Kawano T, Imakawa K, Sakai S
Biochimica et Biophysica Acta
2006年01月, 研究論文（学術雑誌）, 共同, 1759, 132, 140 - Changes in immune cell distribution and IL-10 production are regulated through endometrial IP-10 expression in the goat uterus
Imakawa K, Nagaoka K, Nojima H, Hara Y, Christenson RK
American Journal of Reproductive Immunology
2005年01月, 研究論文（学術雑誌）, 共同, 53, 54, 64 - Increase in DNA methylation down-regulates conceptus interferon-tau gene expression
Nojima H, Nagaoka K, Suda Y, Sakai A, Imakawa K, Christenson RK, Sakai S
Molecular Reproduction and Development
2004年01月, 研究論文（学術雑誌）, 共同, 67, 396, 405 - A chemokine, interferon (IFN)-γ-inducible protein 10 kDa, is stimulated by IFN-τ and recruits immune cells in the ovine endometrium
Nagaoka K, Sakai A, Nojima H, Suda Y, Yokomizo Y, Imakawa K, Sakai S, Christenson RK.
Biology of Reproduction
2003年01月, 研究論文（学術雑誌）, 共同, 68, 1413, 1421 - Regulation of blastocyst migration, apposition, and initial adhesion by a chemokine, interferon-γ-inducible protein 10 kDa (IP-10), during early gestation.
Nagaoka K, Nojima H, Watanabe F, Chang KT, Christenson RK, Sakai S, Imakawa K
The Journal of Biological Chemistry
2003年01月, 研究論文（学術雑誌）, 共同, 278, 29048, 29056 - Change of plasma insulin-like growth factor-1 (IGF-1) concentration with early growth in Japanese beef cattle
Suda Y, Nagaoka K, Nakagawa K, Chiba T, Yusa F, Shinohara H, Nihei A, Yamagishi T
Animal Science Journal
2003年01月, 研究論文（学術雑誌）, 共同, 74, 205, 210 - Mechanisms responsible for increase in circulating inhibin levels at the time of ovulation in mares
Nambo Y, Nagaoka K, Tanaka Y, Nagamine N, Shinbo H, Nagata S, Yoshihara T, Watanabe G, Groome NP, Taya K
Theriogenology
2002年01月, 研究論文（学術雑誌）, 共同, 57, 1707, 1717 - Differentiation of pregnant shiba goats using plasma amino acid concentrations and mathematical analysis
Suda Y, Imakawa K, Nagaoka K, Sakai A, Yoshioka K, Matsuda F, Sakai S, Li JY, Sawasaki T
Journal of Reproduction and Development
2002年01月, 研究論文（学術雑誌）, 共同, 48, 523, 529 - Regulation of interferon-tau gene expression and the maternal recognition of pregnancy
Yamaguchi H, Nagaoka K, Matsuda F, XU N, Christenson RK, Imakawa K, Sakai S
Journal of Reproduction and Development
2001年01月, 共同, 47, 69, 82 - 着床期におけるサイトカイン遺伝子の発現：New and classical approaches
今川和彦、永岡謙太郎、吉岡健一、松田二子、酒井仙吉
日本受精着床学会雑誌
2001年01月, 共同, 18, 38, 41 - Expression of inhibin/activin subunits, aromatase and 3β-hydroxysteroid dehydrogenase in various ovarian antral follicles in the mare.
Nagaoka K, Arai KY, Nagamine N, Nambo Y, Nagata S, Tanaka Y, Shinbo H, Taniyama H, Tsunoda N, Yamanouchi K, Hondo E, Yamada J, Watanabe G, Taya K
Journal of Equine Science
2001年01月, 研究論文（学術雑誌）, 共同, 12, 77, 83 - Enhancer regions of ovine interferon-tau gene that confer PMA response or cell type specific transcription
Yamaguchi H, Nagaoka K, Imakawa K, Sakai S, Christenson RK
Molecular and Cellular Endocrinology
2001年01月, 研究論文（学術雑誌）, 共同, 173, 147, 155 - Testicular secretion of inhibin in the stallion
Taya K, Nagata S, Tsunoda N, Nagamine N, Tanaka Y, Nagaoka K, Taniyama H, Nambo Y, Watanabe G
Journal of Reproduction and Fertility
2000年01月, 共同, Supplement 56, 43, 50 - Ovarian secretion of inhibin in mares
Tanaka N, Nagamine N, Nambo Y, Nagata S, Nagaoka K, Tsunoda N, Taniyama H, Yoshihara T, Oikawa M, Watanabe G Taya K
Journal of Reproduction and Fertility
2000年01月, 共同, Supplement 56, 239, 245 - Implantation in ruminants: Changes in pre-implantation, Maternal recognition of pregnancy, Control of attachment and invasion
Nagaoka K, Yamaguchi H, Aida H, Yoshioka K, Takahashi M, Christenson RK, Imakawa K, Sakai S
Asian-Aus. J. Anim. Sci
2000年01月, 共同, 13, 845, 855 - nhibin pro-αC as the marker of testicular function in the stallion.
Nagata S, Nagaoka K, Shinbo H, Nagamine N, Tsunoda N, Taniyama H, Nambo Y, Groome NP, Watanabe G Taya K
Journal of Reproduction and Development
2000年01月, 研究論文（学術雑誌）, 共同, 46, 201, 206 - A selective increase in circulating inhibin and inhibin pro-αC at the time of ovulation in the mare
Nagaoka K, Nambo Y, Nagamine N, Nagata S, Tanaka Y, Shinbo H, Tsunoda N, Taniyama H, Watanabe G, Groome NP, Taya K
American Journal of Physiology (Endocrinal Metab)
1999年01月, 研究論文（学術雑誌）, 共同, 277, 870, 875 - Inhibin secretion in the mare: localization of inhibin α, βA and βB subunits in the ovary
Nagamine N, Nambo Y, Nagata S, Nagaoka K, Tsunoda N, Taniyama H, Tanaka Y, Tohei A, Watanabe G, Taya K
Biology of Reproduction
1998年01月, 研究論文（学術雑誌）, 共同, 59, 1392, 1398
研究発表、招待講演等
- 泌乳期の母体と子を守る母乳中アミノ酸代謝について
第23回日本乳房炎研究会学術集会
2018年10月12日, 口頭発表（招待・特別） - 精子に発現するL型アミノ酸オキシダーゼを用いた黒毛和種雄ウシの繁殖能評価に関する研究
第111回 日本繁殖生物学会大会
2018年09月15日, 口頭発表（一般） - 雌ウマの発情周期中における腸内細菌叢の変化と性ホルモンとの関係
第111回 日本繁殖生物学会大会
2018年09月13日, 口頭発表（一般） - 哺乳期の母体と子を守る母乳中アミノ酸代謝について
第72回日本栄養・食糧学会大会
2018年05月13日, 口頭発表（招待・特別） - アジアゾウ（Elephas maximus）の哺乳期における腸内細菌叢の形成と母乳中成分の解析
第23回Hindgut Club Japanシンポジウム
2017年12月02日, ポスター発表 - L型アミノ酸オキシダーゼ（LAO）の腸内細菌叢形成と腸肝軸への関与
第22回Hindgut Club Japanシンポジウム
2016年12月03日, ポスター発表 - マウス母乳中のアミノ酸代謝により産生された過酸化水素が乳子の腸内細菌叢形成に関与する
第22回Hindgut Club Japanシンポジウム
2016年12月03日, ポスター発表 - 母乳が整える腸内細菌叢と脳機能の関係
第22回Hindgut Club Japanシンポジウム
2016年12月03日, 口頭発表（招待・特別） - Amino acid metabolizing enzyme, l-amino acid oxidase, controls the contextual memory through modulating acetylcholine level
Neuroscience 2016
2016年11月16日, ポスター発表 - L-amino acid oxidase as the novel marker for sperm fertilizing ability
第109回日本繁殖生物学会大会
2016年09月14日, ポスター発表 - アミノ酸代謝酵素LAO欠損による生体機能に与える影響
第159回日本獣医学会学術集会（生理生化学分科会）
2016年09月07日, その他 - ゴマフアザラシ(Phoca Largha)における初乳から泌乳停止までの母乳中基本成分および乳 中ホルモン濃度の変化
第159回日本獣医学会学術集会（野生動物学分科会）
2016年09月06日, その他 - L型アミノ酸 オキシダーゼ欠損マウスの海馬内神経伝達物質代謝変化と記憶学習能の低下
第10回日本アミノ酸学会
2016年09月, ポスター発表 - 細胞質ポリアデニル化複合体に着目した乳癌抑制分子の研究
TOBIRA第5回研究交流フォーラム
2016年05月23日, ポスター発表 - Oxidative reaction by L-amino acid oxidase mediates maturation of mice sperm
American Society Cell Biology
2015年12月07日, ポスター発表 - CPEB1 mediates epithelial-to-mesenchyme transition and breast cancer metastasis
American Society Cell Biology
2015年12月07日, ポスター発表 - 高L型アミノ酸オキシダーゼ発現ウシ作出に向けた基礎研究
日本乳房炎研究会
2015年10月, ポスター発表 - 母乳中アミノ酸代謝酵素（L-amino acid oxidase）がマウス乳子の腸内細菌叢形成に与える影響
第9回日本アミノ酸学会
2015年10月, ポスター発表 - ウシ L 型アミノ酸オキシダーゼの組換えタンパクの作製とミルク中体細胞を用いた発現解析
日本畜産学会
2015年03月, その他 - 東京農工大学のテ ニュアトラック教員となって
帯広畜産大学テニュアトラックシンポジウム
2015年01月, 口頭発表（招待・特別） - 気候の異なる条件下で育成されたサラブレッド種の発育に関する研究分泌変化に関する研究．
第24回日本ウマ科学会
2011年11月28日, ポスター発表 - 雄ウマにおけるヒト絨毛性性腺刺激ホルモン(hCG)投与後の内因性性腺刺激ホルモンおよび精巣ホルモン分泌変化に関する研究．
第24回日本ウマ科学会
2011年11月28日, ポスター発表 - サラブレッド種繁殖牝馬における後分娩排卵の内分泌学的特徴．
第24回日本ウマ科学会
2011年11月28日, ポスター発表 - 出生直後のエチニル・エストロジェン投与が、雌ラットの春機発動初期の生殖内分泌機能に与える影響．
第16回日本生殖内分泌学会
2011年11月19日, ポスター発表 - Endocrinological function of corpora lutea as a source of inhibin and progesterone during estrous cycle and pregnancy in female elephants.
5th Workshop on Asian Zoo and Wildlife Medicine/Conservation 2011
2011年10月21日, その他 - Effects of the suckling stimulus on ovarian function in lactating female elephants.
5th Workshop on Asian Zoo and Wildlife Medicine/Conservation 2011
2011年10月21日, その他 - ゾウの妊娠期におけるプロラクチン分泌パターンと生理学的役割に関する研究．
第17回日本野生動物医学会
2011年09月29日, ポスター発表 - アジアゾウの排卵停止過程における生殖内分泌学的変化．
第17回日本野生動物医学会
2011年09月29日, ポスター発表 - ゾウの分娩後無排卵期の内分泌学的検討．
第17回日本野生動物医学会
2011年09月29日, その他 - 高プロラクチン血症の雌アフリカゾウにおける乳腺および卵巣の構造的変化
第17回日本野生動物医学会
2011年09月29日, ポスター発表 - 雄カマイルカにおける精巣機能の季節変化．
第17回日本野生動物医学会
2011年09月29日, ポスター発表 - ウズラCoturnix japonicaにおける換羽の発現にかかわる内分泌機構に関する研究．
第17回日本野生動物医学会
2011年09月29日, ポスター発表 - 牡馬の精巣機能検査における、ヒト絨毛性性腺刺激ホルモン(hCG)とウマ絨毛性性腺刺激ホルモン(eCG)のテストステロン(T)分泌反応性の比較．
第152回日本獣医学会
2011年09月19日, その他 - サラブレッド種繁殖牝馬における分娩後発情の内分泌学的解析．
第152回日本獣医学会
2011年09月19日, その他 - アフリカゾウの妊娠維持における胎盤性プロラクチン様物質の生理的役割に関する研究．
第104回日本繁殖生物学会
2011年08月, その他 - Immunolocalization of activins, anti-mullerian hormone (AMH) and their receptors in the equine fetal gonad and placenta.
第104回日本繁殖生物学会
2011年08月, その他 - Secretory pattern of inhibin during estrous cycle and pregnancy in African (Loxodonta africana) and Asian
ICCPB 2011
2011年03月31日, その他 - A clear seasonality of Musth in a captive bull African elephant (Loxodonta africana) in Japan.
2nd Joint Workshop between College of Veterinary Medicine, ,Seoul National University and United Graduate School of Veterinary Sciences, Gifu University
2011年02月20日, その他
外部研究資金等
- 乳酸菌EC-12摂取による脳機能改善効果の検証
共同研究, 自 2017年01月31日, 至 2018年02月28日 - 種雄牛の繁殖性向上技術開発
共同研究, 自 2016年06月10日, 至 2017年03月21日 - 不受胎牛早期判別法の開発事業
共同研究, 自 2016年04月22日, 至 2017年03月31日 - 奨学寄附金
奨学寄附金, 自 2015年, 至 2015年 - 種雄牛の造精能力早期評価法の確立
受託研究, 自 2013年04月01日, 至 2014年03月20日 - 奨学寄附金
奨学寄附金, 自 2013年, 至 2013年
委員歴
- 日本繁殖生物学会
評議員
自 201909, 至 202009 - 日本獣医学会
評議員
自 201909, 至 202003 - 日本繁殖生物学会
男女共同参画推進委員
自 20170401, 至 202003 - 農林水産省
獣医事審議会専門委員
自 20160401, 至 20190331
メディア報道
- 緊張時の腹痛 殺菌乳酸菌摂取で予防 東京農工大学と摂南大学・コンビが発見
農工大農学研究院の永岡謙太郎教授ら研究グループは、緊張時に腹痛を起こす人が1週間前からパラプロバイオティクス（殺菌乳酸菌EC-12）を飲むと、腹痛を予防できることを発見した、と掲載される。
大学ジャーナルonline
自 2024年11月23日, 至 2024年11月23日 - 東京農工大、パラプロバイオティクス（殺菌乳酸菌EC-12)の摂取により緊張に取んなう消火器症状の不調を予防
農工大 永岡謙太郎教授らの研究グループが、パラプロバイオティクス（殺菌乳酸菌EC－１２）の摂取により緊張に伴う消火器症状の不調を予防することを発見した、と掲載される。
日経バイオテク
自 2024年11月18日, 至 2024年11月18日 - 母乳が腸内細菌叢を介して与える影響が、子の脳発達に重要と判明－東京農工大ほか
農工大らの研究グループは、母乳が腸内細菌叢形成を介し、脳発達に与える影響を解明した、と掲載される。
QlifePro医療ニュース
自 2024年06月17日, 至 2024年06月17日 - 東京農工大、母乳が腸内細菌叢形成を介し脳発達に与える影響を解明－母乳中の過酸化水素産性酵素が仔の発達に果たす役割－
農工大大学院農学研究院動物生命科学部門の永岡謙太郎教授らの研究グループが、母乳が仔の腸内細菌叢や脳発達を制御する仕組み解明した、と掲載される。
日経バイオテク
自 2024年06月12日, 至 2024年06月12日 - 赤ちゃんの腸内フローラ多様性を母乳がコントロール 東京農工大学が発見
母乳中のアミノ酸代謝から産生される過酸化水素が、乳子の腸内細菌叢（腸内フローラ）の多様性を低く抑えていることを、東京農工大学の研究グループが明らかにしたことが紹介される。
大学ジャーナル
自 2018年11月22日, 至 2018年11月22日 - 海馬においてアミノ酸代謝が記憶能力に影響することが明らかに-農工大
東京農工大学大学院農学研究院動物生命科学部門・永岡謙太郎准教授、臼田賢人大学院生らの研究グループが、アミノ酸代謝酵素の遺伝子LAO1を欠損したマウスの解析を行った結果、脳内で記憶に関わる海馬においてアミノ酸代謝異常が生じ、特にフェニルアラニン濃度の上昇を確認するとともに、このフェニルアラニン蓄積が神経伝達物質アセチルコリン濃度の減少を引き起こし、LAO1欠損マウスの記憶能力が低下することを証明したことが紹介される。
マイナビニュース／infoseekニュース／ニコニコニュース
自 2018年07月24日, 至 2018年07月24日