1. Journal Club 埼玉医科大学 総合医療センター 内分泌・糖尿病内科 Department of Endocrinology and Diabetes, Saitama Medical Center, Saitama Medical University 松田 昌文 Matsuda, Masafumi 2012 年 2 月 23 日 8:30-8:55 ８階 医局 Atsuhiko Ichimura, Akira Hirasawa, Odile Poulain-Godefroy, Ame´lie Bonnefond, Takafumi Hara, Loı¨c Yengo, Ikuo Kimura, Audrey Leloire, Ning Liu, Keiko Iida, He´le`ne Choquet, Philippe Besnard, Ce´cile Lecoeur, Sidonie Vivequin, Kumiko Ayukawa, Masato Takeuchi, Kentaro Ozawa, Maithe´ Tauber, Claudio Maffeis, Anita Morandi, Raffaella Buzzetti, Paul Elliott, Anneli Pouta, Marjo-Riitta Jarvelin, Antje Ko¨rner,Wieland Kiess, Marie Pigeyre Roberto Caiazzo, Wim Van Hul, Luc Van Gaal, Fritz Horber, Beverley Balkau, Claire Le´vy-Marchal, Konstantinos Rouskas, Anastasia Kouvatsi, Johannes Hebebrand, Anke Hinney, Andre Scherag, Francois Pattou, David Meyre, Taka-aki Koshimizu, Isabelle Wolowczuk, Gozoh Tsujimoto1 & Philippe Froguel Dysfunction of lipid sensor GPR120 leads to obesity in both mouse and human doi:10.1038/nature10798

3. 油脂の加工・精製でできるもの

4. 開発中糖尿病薬 2010 年 第 53 回日本糖尿病学会年次学術集会（岡山） 「新規抗糖尿病薬」シンポジウム Glucokinase 活性薬： β 細胞ブドウ糖センサー活性化でインスリン分泌促進 SGLT-2 阻害薬： 尿からのブドウ糖は排出を促進する。血圧も低下！ Hydroxychloroquine: インスリン血中濃度を維持することで血糖低下 PPARx ： PPARα/γ 作動薬 GPR40 作動薬： インスリン分泌促進薬 (TAK-875) インスリン経口薬 / 吸入薬： インスリン注射に代わるインスリン補充

5. http://www.kyoto-u.ac.jp/ja/news_data/h/h1/news6/2011/120220_1.htm 朝日新聞（ 2 月 20 日 39 面）、京都新聞（ 2 月 20 日 24 面）、産経新聞（ 2 月 20 日 22 面）、日本経済新聞（ 2 月 20 日 34 面）、毎日新聞（ 2 月 20 日 31 面）および読売新 聞（ 2 月 20 日 35 面）に掲載。フジテレビにても放映あり。 GPR120 is a member of the rhodopsin family of G protein-coupled receptors (GPRs) (Fredriksson et al., 2003). GPR120 has also been shown to mediate the anti- inflammatory and insulin- sensitizing effects of omega 3 fatty acids. GPR120 、 GPR40 は α- リノレン酸 (α-LA) などの長鎖不飽和脂肪酸をリガンド. とす る G タンパク質共役型受容体であり、類 似する薬理特性を持っている。

6. 1 Department of Genomic Drug Discovery Science, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan. 2 Centre National de la Recherche Scientifique (CNRS)-Unite´ mixte de recherche (UMR) 8199, Lille Pasteur Institute, Lille 59000, France. 3 Lille Nord de France University, Lille 59000, France. 4 Institut National de la Sante´ et de la Recherche Me´dicale (Inserm)-UMR U866, Physiologie de la Nutrition, Bourgogne University, AgroSup Dijon, Dijon 21078, France. 5 Inserm-U563, Children’s Hospital, Centre Hospitalier Universitaire, Toulouse 31000, France. 6 Regional Centre for Juvenile Diabetes, Obesity and Clinical Nutrition, Verona 37134, Italy. 7 Department of Mother and Child, Biology-Genetics, Section of Paediatrics, University of Verona, Verona 37134, Italy. 8 Department of Clinical Sciences, La Sapienza University,Rome 00161, Italy. 9 Medical Research Council-HPA Centre for Environment and Health, Department of Epidemiology and Biostatistics, School of Public Health, St Mary’s campus, Imperial College London, London W2 1PG, UK. 10 National Public Health Institute, Biocenter Oulu, University of Oulu, Oulu 90220, Finland. 11 Institute of Clinical Medicine/Obstetrics and Gynecology, University of Oulu, Oulu 90220, Finland. 12 Institute of Health Sciences, University of Oulu, Oulu 90220, Finland. 13 Center for Pediatric Research, Department of Women’s&Child Health, University of Leipzig, Leipzig 04317, Germany. 14 Inserm-U859, Lille Nord de France University, Lille 59000, France. 15 Lille University Hospital, Nutrition, Lille 59000, France. 16 Lille University Hospital, Endocrine Surgery, Lille 59000, France. 17 Department of Medical Genetics, University of Antwerp, Antwerp 2610, Belgium. 18 Department of Endocrinology, Antwerp University Hospital, Antwerp 2650, Belgium. 19 Department of Surgery and Internal Medicine, Clinic Lindberg, Medical Department, Winterthur 8400, and University of Berne, Berne 3011, Switzerland. 20 Inserm-U780, Centre for research in Epidemiology and Population Health (CRESP), Villejuif 94800, France. 21 Paris-Sud 11 University, Orsay 91405, France. 22 Inserm-U690, Robert Debre´ hospital, Paris 75935, France. 23 Department of Genetics, Development and Molecular Biology, School of Biology, Aristotle University of Thessaloniki, Thessaloniki 541 24, Greece. 24 Department of Child and Adolescent Psychiatry, University of Duisburg-Essen, Essen 45147, Germany. 25 Institute for Medical Informatics, Biometry and Epidemiology, University of Duisburg-Essen, Essen 45122, Germany. 26 McMaster University, Hamilton, Ontario L8S 4L8, Canada. 27 Department of Pharmacology, Division of Molecular Pharmacology, Jichi Medical University, Tochigi 329-0498, Japan. 28 Department of Genomics of Common Disease, School of Public Health, Imperial College London, Hammersmith Hospital, London W12 0NN, UK. doi:10.1038/nature10798

7. Background Free fatty acids provide an important energy source as nutrients, and act as signalling molecules in various cellular processes. Several G-protein-coupled receptors have been identified as free fatty- acid receptors important in physiology as well as in several diseases. GPR120 (also known as O3FAR1) functions as a receptor for unsaturated long- chain free fatty acids and has a critical role in various physiological homeostasis mechanisms such as adipogenesis, regulation of appetite and food preference.

8. Methods humans and rodents. GPR120-deficient mice were generated by deleting Gpr120 exon 1. Blood analysis, extraction and detection of mRNA and proteins, and immunohistochemical analysis, were performed following standard protocols as described previously. (Details of antibodies, primers and probes are given in Methods.) The level of significance for the difference between data sets was assessed using Student’s t-test. Analysis of variance followed by Tukey’s test was used for multiple comparisons.

9. Methods humans and rodents. In human, GPR120 expression in liver and in both omental and subcutaneous adipose tissues was assessed by quantitative RT– PCR (Taqman), in lean and obese subjects from the Atlas Biologique de l’Obe´site´ Se´ve`re cohort. The four GPR120 exons were sequenced in 312 French, extremely obese subjects following a standard Sanger protocol. The two identified non-synonymous variants (p.R270H and p.R67C/ rs6186610) were subsequently genotyped in a large European obesity case-control study (ncases56,942, ncontrols57,654), by high-resolution melting analysis and TaqMan, respectively. The association between obesity status and each variant was assessed using logistic regression adjusted first for age and gender and then for age, gender and geography origin, under an additive model. The consequences of the two identified non-synonymous variants for GPR120 function ([Ca21]i response and GLP-1 secretion) were assessed in vitro.

10. Figure 1 | Obesity, hypertrophic adipocytes, accumulation of proinflammatory macrophages and hepatic steatosis in HFD- fed GPR120- deficient mice. a, Body weight changes of wild-type (WT) and GPR120- deficient mice fed a normal diet (ND) or a HFD (n=36–47). b, Indirect calorimetry in HFD-fed mice. Energy expenditure and respiratory quotient (n=4, 5). c, Representative cross-sectional images of wild-type and GPR120- deficient mice subjected to microcomputed tomography analysis of the in situ accumulation of fat. Fat depots are demarcated (green) for illustration. d, Haematoxylin and eosin (H&E)-stained epididymal WAT and mean area of adipocytes (n=6). Scale bar, 100 mm. All data represent mean±s.e.m. *P<0.05 and **P<0.01 versus the corresponding wild-type value.

11. Figure 1 | Obesity, hypertrophic adipocytes, accumulation of proinflammatory macrophages and hepatic steatosis in HFD- fed GPR120- deficient mice. e, Relative expression of Cd11b, Cd68 and F4/80 messenger RNA in WAT (n=6). a.u., arbitrary units. f, Representative images of epididymal WAT stained with anti-F4/80 antibody (arrows, F4/80- positive cells) and the number of F4/80 cells (n=6). Scale bar, 100 mm. g, Oil Red O-stained liver and hepatic triglyceride content after 24hr fasting (n=13). Scale bar, 50 mm. All data represent mean±s.e.m. *P<0.05 and **P<0.01 versus the corresponding wild-type value.

12. Figure 2 | Impaired glucose metabolism, adipogenesis and lipogenesis in HFD-fed GPR120- deficient mice. a, Fasting blood glucose and serum insulin levels (n=6–15). b, Plasma glucose during insulin tolerance test (ITT, left) and glucose tolerance test (GTT, right) (n=12–14). c, Phosphorylation of AKT (Ser 473) in WAT, liver and skeletal muscle after 24-hr fasting (n=6, 7). NS, not significant. All data represent mean±s.e.m. *P<0.05 and **P<0.01 versus the corresponding wild-type value.

13. Figure 2 | Impaired glucose metabolism, adipogenesis and lipogenesis in HFD- fed GPR120-deficient mice. d, Relative mRNA expression of Fabp4 and Scd1 inWAT or Scd1 in liver (n=6). e, Protein expression of IRb, IRS1, IRS2, SCD1 and b-actin in WAT. All data represent mean±s.e.m. *P<0.05 and **P<0.01 versus the corresponding wild-type value.

14. Figure 2 | Impaired glucose metabolism, adipogenesis and lipogenesis in HFD-fed GPR120-deficient mice. f, Protein expression of IRS1, IRS2, SCD1 and  -actin in liver. g, Oil Red O-staining and triglyceride (TG) content of mouse embryonic fibroblast (MEF)-derived adipocyte. Scale bar, 50 mm. All data represent mean±s.e.m. *P<0.05 and **P<0.01 versus the corresponding wild-type value.

15. Figure 2 | Impaired glucose metabolism, adipogenesis and lipogenesis in HFD-fed GPR120-deficient mice. h, Relative mRNA expression in MEF- derived adipocyte (n=6). i, The ratio of C18:1 to C18:0 in livers (n=6–8). j, Non- esterified C16:1n7 palmitoleate in WAT and plasma (n=4–7). k, The ratio of Scd1 mRNA expression in liver and WAT (n=6, 7). l, The ratio of C16:1 to C16:0 in adipose tissues (n=6–8). m, Hepatic Scd1 mRNA expression in mice infused with vehicle or triglyceride:palmitoleate for 6h (n=4, 5). All data represent mean±s.e.m. *P<0.05 and **P<0.01 versus the corresponding wild-type value.

16. Figure 3 | GPR120 expression in human obese tissue samples, and effect of GPR120 variants on [Ca 2+ ] i response and GLP- 1 secretion. a, GPR120 mRNA levels in human subcutaneous (SC) and omental (OM) adipose tissues of lean (LN; n=14) and obese (OB; n=14) normoglycaemic individuals. Mann– Whitney analysis, ***P=0.0004 and **P=0.003. b, ALA-induced [Ca 2+ ] i responses in cells expressing wild-typeGPR120 or a p.R67C or p.R270Hvariant. c, ALA-induced GLP-1 secretion in NCI-H716 cells expressing a wild-type GPR120, a p.R67C or a p.R270H receptor. d, Effect of transfection with GPR120 variants on ALA- induced [Ca 2+ ] i response in cells stably expressing wild-type GPR120. **P<0.01 versus the corresponding control value. RFI, relative fluorescence intensity; RFU, relative fluorescence unit. All data show mean±s.e.m.

17. Figure 3 | GPR120 expression in human obese tissue samples, and effect of GPR120 variants on [Ca 2+ ] i response and GLP-1 secretion. e, Effect of co-expression of human GPR120 p.R270H variant with wild-type GPR120 on ALA- induced [Ca 2+ ] i response. Top: schematic diagram of constructs. Bottom: expression of wild type and p.R270H (left), and concentration–[Ca 2+ ] i response for ALA in cells expressing wild- type/wildtype, wild-type/R270Hor R270H/wild-type receptors (right). **P<0.01 versus the corresponding control value. RFI, relative fluorescence intensity; RFU, relative fluorescence unit. All data show mean±s.e.m.

19. Results Here we show that GPR120-deficient mice fed a high-fat diet develop obesity, glucose intolerance and fatty liver with decreased adipocyte differentiation and lipogenesis and enhanced hepatic lipogenesis. Insulin resistance in such mice is associated with reduced insulin signalling and enhanced inflammation in adipose tissue. In human, we show that GPR120 expression in adipose tissue is significantly higher in obese individuals than in lean controls. GPR120 exon sequencing in obese subjects reveals a deleterious non-synonymous mutation (p.R270H) that inhibits GPR120 signalling activity. Furthermore, the p.R270H variant increases the risk of obesity in European populations.

20. Conclusion Overall, this study demonstrates that the lipid sensor GPR120 has a key role in sensing dietary fat and, therefore, in the control of energy balance in both humans and rodents.

21. Message 脂肪のとりすぎによる肥満リスクが高まる 特定の遺伝子が損なわれると、脂肪のとりすぎによる肥満リスクが高まることを 京都大の辻本豪三教授（ゲノム創薬科学）らが突き止めた。遺伝的に太りやすい人 の診断や、肥満予防薬の開発につながるという。２０日付の英国の科学誌ネイ チャー電子版に発表した。 「ＧＰＲ１２０」という遺伝子が、食べ物に含まれる脂肪酸を感知して、インス リン分泌を促したり、食欲を抑えたりする働きに関係することが既に知られている。 研究グループはこの遺伝子を壊したマウスと通常のマウスそれぞれ数十匹ずつに 低脂肪（１３％）と、高脂肪（６０％）の２種類の餌を与え、１６週間飼育して比 較した。 低脂肪食のマウスの体重は共に平均約３０グラムでほとんど差はなかった。高脂 肪食の通常マウスは同約４０グラムだったが、遺伝子欠損マウスは同約４４．４グ ラム。特に肝臓の重量は欠損マウスの方が約７０％も重く、中性脂肪の多い脂肪肝 だった。血糖値も高く、インスリンを投与してもほとんど効き目がなかった。 さらにフランスの研究所が持つ欧州人約１万４６００人の遺伝情報を肥満度別に 解析。肥満グループの２．４％にＧＰＲ１２０の変異（機能低下）があったが、非 肥満グループでは変異は１．３％。この遺伝子の変異が肥満リスクを高めることが 明らかになった。 辻本教授は「西洋型の高脂肪の食生活と遺伝子の機能低下が重なると、肥満や糖 尿病のリスクが高まる。さらにメカニズムを解明し、病的肥満の診断や予防に役立 てたい」と話している。 毎日新聞 2012 年 2 月 20 日 3 時 00 分