title: Oncostatin m is produced in adipose tissue and is regulated in conditions of obesity and type 2 diabetes.
abstract: BACKGROUND
  Adipose tissue is a highly active endocrine organ that secretes many factors that affect other tissues and whole-body metabolism. Adipocytes are responsive to several glycoprotein 130 (gp130) cytokines, some of which have been targeted as potential antiobesity therapeutics.
  
  
  OBJECTIVE
  Oncostatin M (OSM) is a gp130 family member known to inhibit adipocyte differentiation in vitro, but its effects on other adipocyte properties are not characterized. The expression of OSM in white adipose tissue (WAT) has not been evaluated in the context of obesity. Thus, our objective was to examine the expression of adipose tissue OSM in obese animals and humans.
  
  
  METHODS
  OSM expression was examined in adipose tissues from mice with diet-induced and genetic obesity and in obese humans as well as in fractionated adipose tissue from mice. Murine adipocytes were used to examine OSM receptor expression and the effects of OSM on adipocytes, including the secretion of factors such as plasminogen activator inhibitor 1 and IL-6, which are implicated in metabolic diseases.
  
  
  RESULTS
  OSM expression is increased in rodent and human obesity/type 2 diabetes mellitus. In humans, OSM levels correlate with body weight and insulin and are inversely correlated with glucose disposal rate as measured by hyperinsulinemic-euglycemic clamp. OSM is not produced from the adipocytes in WAT but derives from cells in the stromovascular fraction, including F4/80(+) macrophages. The specific receptor of OSM, OSM receptor-β, is expressed in adipocytes and adipose tissue and increased in both rodent models of obesity examined. OSM acts on adipocytes to induce the expression and secretion of plasminogen activator inhibitor 1 and IL-6.
  
  
  CONCLUSIONS
  These data indicate that WAT macrophages are a source of OSM and that OSM levels are significantly induced in murine and human obesity/type 2 diabetes mellitus. These studies suggest that OSM produced from immune cells in WAT acts in a paracrine manner on adipocytes to promote a proinflammatory phenotype in adipose tissue.
authors.affiliation: Pennington Biomedical Research Center (D.S.-I., U.A.W., C.M.E., J.M.G., E.R., J.M.S.) and Department of Biological Sciences (J.M.S.), Louisiana State University, Baton Rouge, Louisiana 70808; Department of Nutrition (R.F.M.), UNC-Greensboro, Greensboro, North Carolina 24702; Indiana University School of Medicine (R.V.C.), Indianapolis, Indiana 46202; Department of Medicine (A.W.F.), Columbia University, New York, New York 10032; and Endocrinology Department (D.S.-I.), St Joan de Deu, 08950 Barcelona, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Sanchez-Infantes
authors.forename: Ursula A
authors.initials: UA
authors.lastname: White
authors.forename: Carrie M
authors.initials: CM
authors.lastname: Elks
authors.forename: Ron F
authors.initials: RF
authors.lastname: Morrison
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Gimble
authors.forename: Robert V
authors.initials: RV
authors.lastname: Considine
authors.forename: Anthony W
authors.initials: AW
authors.lastname: Ferrante
authors.forename: Eric
authors.initials: E
authors.lastname: Ravussin
authors.forename: Jacqueline M
authors.initials: JM
authors.lastname: Stephens
mesh_terms: D041721:3T3-L1 Cells; D000273:Adipose Tissue / Q000378:metabolism*; D000818:Animals; D003924:Diabetes Mellitus, Type 2 / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D006801:Humans; D008297:Male; D051379:Mice; D009765:Obesity / Q000235:genetics / Q000378:metabolism*; D053683:Oncostatin M / Q000235:genetics / Q000378:metabolism*; D053677:Receptors, Oncostatin M / Q000235:genetics / Q000378:metabolism*
chemical_list: D053677:Receptors, Oncostatin M; D053683:Oncostatin M