Transcript 20120223GPR120 - 埼玉医科大学総合医療センター 内分泌

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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
2012年2月23日 8:30-8:55
８階 医局
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
油脂の加工・精製でできるもの
開発中糖尿病薬
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！
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
PPARx：
PPARα/γ作動薬
Hydroxychloroquine:
インスリン血中濃度を維持することで血糖低下
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
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
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 antiinflammatory and insulinsensitizing 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。
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http://www.kyoto-u.ac.jp/ja/news_data/h/h1/news6/2011/120220_1.htm
1Department
of Genomic Drug Discovery Science, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto
606-8501, Japan. 2Centre National de la Recherche Scientifique (CNRS)-Unite´ mixte de recherche (UMR) 8199, Lille Pasteur Institute, Lille 59000, France. 3Lille Nord
de France University, Lille 59000, France. 4Institut National de la Sante´ et de la Recherche Me´dicale (Inserm)-UMR U866, Physiologie de la Nutrition, Bourgogne
University, AgroSup Dijon, Dijon 21078, France. 5Inserm-U563, Children’s Hospital, Centre Hospitalier Universitaire, Toulouse 31000, France. 6Regional Centre for
Juvenile Diabetes, Obesity and Clinical Nutrition, Verona 37134, Italy. 7Department of Mother and Child, Biology-Genetics, Section of Paediatrics, University of
Verona, Verona 37134, Italy. 8Department of Clinical Sciences, La Sapienza University,Rome 00161, Italy. 9Medical 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. 10National
Public Health Institute, Biocenter Oulu, University of Oulu, Oulu 90220, Finland. 11Institute of Clinical Medicine/Obstetrics and Gynecology, University of Oulu, Oulu
90220, Finland. 12Institute of Health Sciences, University of Oulu, Oulu 90220, Finland. 13Center for Pediatric Research, Department of Women’s&Child Health,
University of Leipzig, Leipzig 04317, Germany. 14Inserm-U859, Lille Nord de France University, Lille 59000, France. 15Lille University Hospital, Nutrition, Lille 59000,
France. 16Lille University Hospital, Endocrine Surgery, Lille 59000, France. 17Department of Medical Genetics, University of Antwerp, Antwerp 2610, Belgium.
18Department of Endocrinology, Antwerp University Hospital, Antwerp 2650, Belgium. 19Department of Surgery and Internal Medicine, Clinic Lindberg, Medical
Department, Winterthur 8400, and University of Berne, Berne 3011, Switzerland. 20Inserm-U780, Centre for research in Epidemiology and Population Health (CRESP),
Villejuif 94800, France. 21Paris-Sud 11 University, Orsay 91405, France. 22Inserm-U690, Robert Debre´ hospital, Paris 75935, France. 23Department of Genetics,
Development and Molecular Biology, School of Biology, Aristotle University of Thessaloniki, Thessaloniki 541 24, Greece. 24Department of Child and Adolescent
Psychiatry, University of Duisburg-Essen, Essen 45147, Germany. 25Institute for Medical Informatics, Biometry and Epidemiology, University of Duisburg-Essen,
Essen 45122, Germany. 26McMaster University, Hamilton, Ontario L8S 4L8, Canada. 27Department of Pharmacology, Division of Molecular Pharmacology, Jichi
Medical University, Tochigi 329-0498, Japan. 28Department of Genomics of Common Disease, School of Public Health, Imperial College London, Hammersmith
Hospital, London W12 0NN, UK.
doi:10.1038/nature10798
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 longchain free fatty acids and has a critical role in
various physiological homeostasis
mechanisms such as adipogenesis,
regulation of appetite and food preference.
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.
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.
Figure 1 | Obesity, hypertrophic adipocytes, accumulation of proinflammatory macrophages and hepatic steatosis in HFDfed 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.
Figure 1 | Obesity, hypertrophic adipocytes,
accumulation of proinflammatory
macrophages and hepatic steatosis in HFDfed 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.
Figure 2 | Impaired glucose
metabolism, adipogenesis and
lipogenesis in HFD-fed GPR120deficient 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.
Figure 2 | Impaired
glucose metabolism,
adipogenesis and
lipogenesis in HFDfed 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.
Figure 2 | Impaired glucose
metabolism, adipogenesis
and lipogenesis in HFD-fed
GPR120-deficient mice.
f, Protein expression of IRS1,
IRS2, SCD1 and b-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.
Figure 2 | Impaired glucose metabolism,
adipogenesis and lipogenesis in HFD-fed
GPR120-deficient mice.
h, Relative mRNA expression in MEFderived adipocyte (n=6). i, The ratio of
C18:1 to C18:0 in livers (n=6–8). j, Nonesterified 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.
Figure 3 | GPR120 expression in human obese tissue samples, and effect of GPR120 variants on [Ca2+]i response and GLP1 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 [Ca2+]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 ALAinduced [Ca2+]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.
Figure 3 | GPR120 expression in human obese tissue samples, and effect of GPR120
variants on [Ca2+]i response and GLP-1 secretion.
e, Effect of co-expression of human GPR120 p.R270H variant with wild-type GPR120 on ALAinduced [Ca2+]i response. Top: schematic diagram of constructs. Bottom: expression of wild
type and p.R270H (left), and concentration–[Ca2+]i response for ALA in cells expressing wildtype/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.
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.
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.
Message
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