title: Inhibition of myostatin protects against diet-induced obesity by enhancing fatty acid oxidation and promoting a brown adipose phenotype in mice.
abstract: OBJECTIVE
  Although myostatin-null (Mstn (-/-)) mice fail to accumulate fat in adipose tissue when fed a high-fat diet (HFD), little is known about the molecular mechanism(s) behind this phenomenon. We therefore sought to identify the signalling pathways through which myostatin regulates accumulation and/or utilisation of fat.
  
  
  METHODS
  Wild-type, Mstn (-/-) and wild-type mice treated with soluble activin type IIB receptor (sActRIIB) were fed a control chow diet or an HFD for 12 weeks. Changes in gene expression were measured by microarray and quantitative PCR. Histological changes in white adipose tissue were assessed together with peripheral tissue fatty acid oxidation and changes in circulating hormones following HFD feeding.
  
  
  RESULTS
  Our results demonstrate that inactivation of myostatin results in reduced fat accumulation in mice on an HFD. Molecular analysis revealed that metabolic benefits, due to lack of myostatin, are mediated through at least two independent mechanisms. First, lack of myostatin increased fatty acid oxidation in peripheral tissues through induction of enzymes involved in lipolysis and in fatty acid oxidation in mitochondria. Second, inactivation of myostatin also enhanced brown adipose formation in white adipose tissue of Mstn (-/-) mice. Consistent with the above, treatment of HFD-fed wild-type mice with the myostatin antagonist, sActRIIB, reduced the obesity phenotype.
  
  
  CONCLUSIONS
  We conclude that absence of myostatin results in enhanced peripheral tissue fatty acid oxidation and increased thermogenesis, culminating in increased fat utilisation and reduced adipose tissue mass. Taken together, our data suggest that anti-myostatin therapeutics could be beneficial in alleviating obesity.
authors.affiliation: Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research (A*STAR), Brenner Centre for Molecular Medicine, Singapore, Republic of Singapore.
authors.forename: C
authors.initials: C
authors.lastname: Zhang
authors.forename: C
authors.initials: C
authors.lastname: McFarlane
authors.forename: S
authors.initials: S
authors.lastname: Lokireddy
authors.forename: S
authors.initials: S
authors.lastname: Masuda
authors.forename: X
authors.initials: X
authors.lastname: Ge
authors.forename: P D
authors.initials: PD
authors.lastname: Gluckman
authors.forename: M
authors.initials: M
authors.lastname: Sharma
authors.forename: R
authors.initials: R
authors.lastname: Kambadur
mesh_terms: D030301:Activin Receptors, Type II / Q000737:chemistry / Q000627:therapeutic use; D002001:Adipose Tissue, Brown / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D050154:Adiposity / Q000187:drug effects; D000818:Animals; D019440:Anti-Obesity Agents / Q000737:chemistry / Q000627:therapeutic use*; D059305:Diet, High-Fat / Q000009:adverse effects*; D005227:Fatty Acids / Q000378:metabolism*; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000187:drug effects; D008066:Lipolysis / Q000187:drug effects; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D058990:Molecular Targeted Therapy; D009124:Muscle Proteins / Q000235:genetics / Q000378:metabolism; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism; D055435:Myostatin / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D009765:Obesity / Q000209:etiology / Q000378:metabolism* / Q000473:pathology / Q000517:prevention & control; D010084:Oxidation-Reduction / Q000187:drug effects; D012333:RNA, Messenger / Q000378:metabolism; D012995:Solubility
chemical_list: D019440:Anti-Obesity Agents; D005227:Fatty Acids; C525912:Mstn protein, mouse; D009124:Muscle Proteins; D055435:Myostatin; D012333:RNA, Messenger; D030301:Activin Receptors, Type II; C425584:activin receptor type II-B