Okamoto Shiki

写真a

Title

Assistant Professor

Researcher Number(JSPS Kakenhi)

40342919

Current Affiliation Organization 【 display / non-display

  • Duty   University of the Ryukyus   Graduate School of Medicine   Assistant Professor  

University 【 display / non-display

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    1996

    Hokkaido University   Faculty of Veterinary Medicine   Graduated

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    2000

    Hokkaido University     Graduated

External Career 【 display / non-display

  • 1900.01
     
     

    University of the Ryukyus Department of Developmental Physiology, Developmental Physiology  

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  • 1997.04
     
     

     

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Affiliated academic organizations 【 display / non-display

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    THE PHYSIOLOGICAL SOCIETY OF JAPAN 

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    Japan society of experimental diabetes and obesity 

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    The Japan Endocrine Society 

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    THE JAPAN DIABETES SOCIETY 

Research Interests 【 display / non-display

  • Food preference

  • 視床下部

  • 肥満

  • エネルギー代謝

Research Areas 【 display / non-display

  • Life Science / Neuroscience-general

  • Life Science / Physiology

  • Life Science / Metabolism and endocrinology

  • Life Science / Animal physiological chemistry, physiology and behavioral biology

Published Papers 【 display / non-display

  • Analysis of spot urine biomarkers and association with body weight in Japanese elementary schoolchildren.

    Takemoto N, Millman J, Uema T, Yamakawa F, Okamoto S, Mori M, Mori H, Nakamura K, Yamori Y, Masuzaki H

    European journal of pediatrics ( European Journal of Pediatrics )  181 ( 11 ) 3879 - 3888   2022.11 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

     View Summary

    Childhood obesity is rapidly increasing worldwide and is largely the consequence of adoption of unhealthy diets excessive in calories and salt (NaCl) as well as devoid in pivotal micronutrients such as potassium (K) and magnesium (Mg). Education-based programs aiming to encourage healthy food knowledge and behaviors are crucial at a young age, and for this purpose, convenient ways to assess daily dietary intake are warranted. We therefore attempted to evaluate the dietary intake of Okinawan schoolchildren in Japan by analyzing a series of biomarkers in morning spot urine samples and explore whether these biomarkers correlate with body weight and a series of metabolic parameters. We enrolled 98 third-grade elementary schoolchildren in Okinawa, Japan. Morning spot urine samples were collected and analyzed using high-performance liquid chromatography (HPLC) to assess dietary intake. We found that estimated daily NaCl intake was higher in obese/overweight children as compared to healthy-weight children (p = 0.0001). There was also a significant positive correlation between body mass index (BMI) and NaCl intake (Spearman) (ρ = 0.45, p < 0.0001) and a negative correlation between BMI and Mg/Cr (ρ =  -0.27, p = 0.01). Furthermore, Na/K ratio was higher in samples collected on Monday (weekend) as compared to samples collected on Thursday or Friday (weekday) (p < 0.0001). CONCLUSION: Via the use of morning spot urine analyses, our results show that NaCl intake was associated with obesity, and Mg excretion negatively correlated with BMI in Japanese schoolchildren, highlighting the potential role of these micronutrients in maintaining a healthy body weight. WHAT IS KNOWN: •Overweight and obesity are largely due to excessive consumption of calories and positively correlated with salt (NaCl) intake. •Spot urine methods are convenient for assessing the nutritional needs and targeting prevention programs in children. WHAT IS NEW: •Utilizing morning spot urine analyses, estimated NaCl intake is positively correlated and Mg/Cr negatively correlated with BMI in Okinawan schoolchildren. •As estimated via morning spot urine samples, a greater proportion of children likely exceeds the recommended NaCl intake on the weekend as compared to weekday.

  • Profile of gut microbiota and serum metabolites associated with metabolic syndrome in a remote island most afflicted by obesity in Japan

    Uema Tsugumi, Millman Jasmine F., Okamoto Shiki, Nakamura Takehiro, Yamashiro Kiyoto, Uehara Moriyuki, Honma Ken-ichiro, Miyazato Minoru, Ashikari Asuka, Saito Seiichi, Maeda Shiro, Imamura Minako, Ishida Hajime, Matsushita Masayuki, Nakamura Koshi, Masuzaki Hiroaki

    SCIENTIFIC REPORTS ( Scientific Reports )  12 ( 1 ) 17292 - 17292   2022.10 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

     View Summary

    Numerous studies have revealed distinct differences in the profiles of gut microbiota between non-obese and obese individuals. To date, however, little is known if any disparities in the community of gut microbiota exist between metabolically healthy obese (MHO) and metabolically unhealthy obese (MUO) subjects. We therefore aimed to comprehensively characterize the gut microbiota and circulating metabolites in serum from both MHO and MUO residing in the remote island, Kumejima, where the prevalence of obesity is one of the highest in Japan, and explored possible correlations between the gut microbiota profile and markers of metabolic syndrome. Results revealed that MUO showed significantly higher levels of genera such as g_Succinivibrio, g_Granulicatella, g_Brachyspira, g_Oribacterium and g_Atopobium in comparison to MHO. Moreover, abundance of g_Succinivibrio, g_Brachyspira and g_Atopobium were positively correlated with value of fasting insulin, HOMA-R, circulating triglycerides, diastolic blood pressure, BMI, body weight, waist circumference and HbA1c. In addition, MUO compared to MHO showed an imbalance of serum metabolites, with a significant elevation in 2-oxoisovaleric acid, pyruvic acid, 2-hydroxybutyric acid, and creatine. Our data highlight unmet needs in precision approaches for the treatment of obesity, targeting the gut microbiota profile and serum metabolites in a distinct population affected by obesity.

  • Brown adipose tissue dysfunction promotes heart failure via a trimethylamine N-oxide-dependent mechanism.

    Yoshida Y, Shimizu I, Shimada A, Nakahara K, Yanagisawa S, Kubo M, Fukuda S, Ishii C, Yamamoto H, Ishikawa T, Kano K, Aoki J, Katsuumi G, Suda M, Ozaki K, Yoshida Y, Okuda S, Ohta S, Okamoto S, Minokoshi Y, Oda K, Sasaoka T, Abe M, Sakimura K, Kubota Y, Yoshimura N, Kajimura S, Zuriaga M, Walsh K, Soga T, Minamino T

    Scientific reports ( Scientific Reports )  12 ( 1 ) 14883   2022.09 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

     View Summary

    Abstract Low body temperature predicts a poor outcome in patients with heart failure, but the underlying pathological mechanisms and implications are largely unknown. Brown adipose tissue (BAT) was initially characterised as a thermogenic organ, and recent studies have suggested it plays a crucial role in maintaining systemic metabolic health. While these reports suggest a potential link between BAT and heart failure, the potential role of BAT dysfunction in heart failure has not been investigated. Here, we demonstrate that alteration of BAT function contributes to development of heart failure through disorientation in choline metabolism. Thoracic aortic constriction (TAC) or myocardial infarction (MI) reduced the thermogenic capacity of BAT in mice, leading to significant reduction of body temperature with cold exposure. BAT became hypoxic with TAC or MI, and hypoxic stress induced apoptosis of brown adipocytes. Enhancement of BAT function improved thermogenesis and cardiac function in TAC mice. Conversely, systolic function was impaired in a mouse model of genetic BAT dysfunction, in association with a low survival rate after TAC. Metabolomic analysis showed that reduced BAT thermogenesis was associated with elevation of plasma trimethylamine N-oxide (TMAO) levels. Administration of TMAO to mice led to significant reduction of phosphocreatine and ATP levels in cardiac tissue via suppression of mitochondrial complex IV activity. Genetic or pharmacological inhibition of flavin-containing monooxygenase reduced the plasma TMAO level in mice, and improved cardiac dysfunction in animals with left ventricular pressure overload. In patients with dilated cardiomyopathy, body temperature was low along with elevation of plasma choline and TMAO levels. These results suggest that maintenance of BAT homeostasis and reducing TMAO production could be potential next-generation therapies for heart failure.

  • Fermented brown rice beverage distinctively modulates the gut microbiota in Okinawans with metabolic syndrome: A randomized controlled trial

    Akamine Yukari, Millman Jasmine F., Uema Tsugumi, Okamoto Shiki, Yonamine Masato, Uehara Moriyuki, Kozuka Chisayo, Kaname Tadashi, Shimabukuro Michio, Kinjo Kozen, Mitsuta Masayo, Watanabe Hirosuke, Masuzaki Hiroaki

    NUTRITION RESEARCH ( Nutrition Research )  103   68 - 81   2022.07 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

     View Summary

    Accumulating evidence to date suggests that brown rice is superior to white rice in regard to its beneficial impact on a number of risk factors of the metabolic syndrome (MetS). However, little is known about the influence of fermented brown rice beverage on the gut microbiota in humans. We therefore hypothesized that its impact would beneficially alter the gut microbiota composition of patients with MetS. Using a 4-week randomized, single-arm study design, subjects (n = 40) were advised to consume a daily fermented brown rice beverage (BA) or fermented white rice beverage (WA) as a replacement of their main meal. Clinical and anthropometric measurements as well as fecal samples were collected at baseline and immediately after completion of the intervention. Gut microbiota was analyzed using 16S ribosomal RNA sequencing and capillary electrophoresis-time-of-flight mass spectrometry was used to measure plasma short-chain fatty acids. Interestingly, ingestion of BA in contrast to WA resulted in a unique elevation in the abundance of number of beneficial species belonging to the Clostridia class, associated with reduced inflammation, and increased short-chain fatty acid production: Lactobacillales bacterium DJF B280 (P = .005), Butyrate producing bacterium A2 207 (P = .012), and Firmicutes bacterium DJF VP44 (P = .038). This study demonstrates that consumption of BA is effective to beneficially modulate the gut microbiota compared with WA in patients with MetS.

  • Coexistence of sensory qualities and value representations in human orbitofrontal cortex.

    Yoshimoto T, Okazaki S, Sumiya M, Takahashi HK, Nakagawa E, Koike T, Kitada R, Okamoto S, Nakata M, Yada T, Kosaka H, Sadato N, Chikazoe J

    Neuroscience research ( Neuroscience Research )  180   48 - 57   2022.07 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

     View Summary

    Despite the multiple regions and neural networks associated with value-based decision-making, the orbitofrontal cortex (OFC) is possible a particularly important one. Although the role of the OFC in reinforcer devaluation tasks, which assess the ability to represent identity, sensory qualities, and subjective values of the expected outcomes, has been established, the specific aspect represented in this area remains unclear. In this study, using functional magnetic resonance imaging, wherein participants rated the palatability of 128 food items using photographs, we investigated whether the human OFC represents object identity, sensory qualities, or value. Employing many items helped us dissociate object identity from sensory qualities and values; the inferred sensory qualities of identical items were manipulated by a change in metabolic state. Moreover, value differences between items were analytically controlled by employing a technique similar to age adjustment. The palatability ratings for food items significantly decreased after a meal. Using representational similarity analysis, we confirmed that the OFC represents value. Moreover, identical items were represented similarly in the lateral OFC in a given metabolic state; however, these representations were altered post-feeding. Importantly, this change was not explained by subjective value, suggesting that the OFC represents sensory quality and value, but not object identity.

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Books 【 display / non-display

  • Peripheral IL-6 and TNF expressions induced by brain IL-1: New aspect of the acute phase response in liver. Liver Innervation and the Neural Control of Hepatic Function

    Kitamura H, Okamoto S, Shimamoto Y, Terao A, Morimatsu M, Saito, M ( Part: Multiple Authorship ,  Liver Innervation and the Neural Control of Hepatic Function (Ed. Shimazu T) pp. 213-219, )

    John Libbey & Company, London  1996.06

Other Papers 【 display / non-display

  • マウスにおいてエクストラヴァージンオリーブオイルとアマニ油は腸内細菌叢に影響を及ぼして粘膜免疫と代謝的健康を促進する(Extra virgin olive and flaxseed oils impact gut microbiota, enhancing mucosal immunity and metabolic health in mice)

    ミルマン・ジャスミン, 岡本 士毅, 上間 次己, 比嘉 萌子, 難波 豊隆, 山崎 聡, 島袋 充生, 池松 真也, 益崎 裕章

    日本抗加齢医学会総会プログラム・抄録集 ( (一社)日本抗加齢医学会 )  20回   223 - 223   2020.09  [Refereed]

     

  • 玄米機能成分を活かした脳機能改善と生活習慣病予防のアプローチ

    益崎裕章, 小塚智沙代, 與那嶺正人, 岡本士毅

    日本農芸化学会大会講演要旨集(Web)   2018   ROMBUNNO.4SY09‐4 (WEB ONLY)   2018.03

     

    J-GLOBAL

  • 玄米機能成分を活用した脳機能の改善

    益崎裕章, 小塚智沙代, 小塚智沙代, 金城綾乃, 與那嶺正人, 岡本士毅, 田仲秀明, 田仲秀明, 島袋充生

    日本生物工学会大会講演要旨集   69th   194   2017.08

     

    J-GLOBAL

  • The role of central AMPK for controlling feeding behavior

      41 ( 1 ) 9 - 13   2015.07  [Refereed]

     

  • Regulation for Food Intake and Energy Metabolism

    箕越 靖彦, 中里 雅光, 佐藤 亜希子, 前島 裕子, 影山 晴秋, 岡本 士毅, 十枝内 厚次, 有馬 寛

    肥満研究 : 日本肥満学会誌 = Journal of Japan Society for the Study of Obesity   17 ( 3 )   2011.12

     

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Presentations 【 display / non-display

  • A Subset of CRH Neurons in the Paraventricular Hypothalamus Regulates Dietary Preference for Carbohydrate over Fat via AMPK

    岡本 士毅

    Consortium of Biological Sciences 20  2017.12  -  2017.12 

  • AMP-activated Protein Kinase in CRH Neurons in the PVH regulates Food Selection Behavior

    OKAMOTO Shiki

    AMP-activated Protein Kinase in CRH Neurons in the PVH regulates Food Selection Behavior  2017.12  -  2017.12 

  • AMP-activated protein kinase in CRH neurons in the PVH controls food selection behavior

    岡本 士毅

    第60 回日本糖尿病学会年次学術集会  2017.05  -  2017.05 

  • AMPK in the paraventricular hypothalamic nucleus regulates food selection behavior in mice

    岡本 士毅

    第94回日本生理学会大会  2017.03  -  2017.03 

  • AMP-activated protein kinase in CRH neurons in the PVH controls food selection behavior

    岡本 士毅

    The 36th The Annual Meeting of Japan Society for the Study of Obesity, The 8th Asia-Oceania Conference on Obesity, The 46th NIPS International Symposium, Symposium2  2015.10  -  2015.10 

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Academic Awards 【 display / non-display

  • Travel Grant

    2002.07   International Society for Experimental Hematology  

    Winner: OKAMOTO Shiki