title: Leptin expression in adipose tissue from obese humans: depot-specific regulation by insulin and dexamethasone.
abstract: We investigated the in vitro regulation of leptin expression in adipose tissue from severely obese women and men before and after culture with insulin (7 nM) and/or dexamethasone (25 nM). Leptin mRNA and leptin secretion were two- to threefold higher in subcutaneous vs. omental adipose tissue before culture. Dexamethasone transiently increased leptin mRNA approximately twofold in both depots after 1 day of culture [P < 0.01 vs. basal (no hormone control)], but leptin secretion was only increased in omental adipose tissue (P < 0.005 vs. basal). Insulin did not increase leptin mRNA in either depot but increased leptin secretion approximately 1.5- to 3-fold in subcutaneous tissue throughout 7 days of culture (P < 0.05 vs. basal). The combination of insulin and dexamethasone increased leptin mRNA and leptin secretion approximately two- to threefold in both depots at day 1 (P < 0.005 vs. basal or insulin) and maintained leptin expression throughout 7 days of culture. We conclude that insulin and glucocorticoid have depot-specific effects and function synergistically as long-term regulators of leptin expression in omental and subcutaneous adipose tissue from obese subjects.
authors.affiliation: Department of Nutritional Sciences, Rutgers, The State University of New Jersey, New Brunswick, New Jersey 08901, USA.
authors.forename: C D
authors.initials: CD
authors.lastname: Russell
authors.forename: R N
authors.initials: RN
authors.lastname: Petersen
authors.forename: S P
authors.initials: SP
authors.lastname: Rao
authors.forename: M R
authors.initials: MR
authors.lastname: Ricci
authors.forename: A
authors.initials: A
authors.lastname: Prasad
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.forename: R E
authors.initials: RE
authors.lastname: Brolin
authors.forename: S K
authors.initials: SK
authors.lastname: Fried
mesh_terms: D000005:Abdomen; D000273:Adipose Tissue / Q000187:drug effects / Q000378:metabolism*; D000328:Adult; D002478:Cells, Cultured; D003907:Dexamethasone / Q000494:pharmacology*; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D007328:Insulin / Q000494:pharmacology* / Q000502:physiology; D007700:Kinetics; D020738:Leptin; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000235:genetics / Q000378:metabolism*; D009852:Omentum; D017697:Premenopause; D014176:Protein Biosynthesis; D011506:Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000096:biosynthesis; D012867:Skin; D013997:Time Factors; D014158:Transcription, Genetic / Q000187:drug effects / Q000502:physiology
chemical_list: D007328:Insulin; D020738:Leptin; D011506:Proteins; D012333:RNA, Messenger; D003907:Dexamethasone