title: The effects of temperature and seasons on subcutaneous white adipose tissue in humans: evidence for thermogenic gene induction.
abstract: BACKGROUND
  Although brown adipose tissue (BAT) activity is increased by a cold environment, little is known of the response of human white adipose tissue (WAT) to the cold.
  
  
  METHODS
  We examined both abdominal and thigh subcutaneous (SC) WAT from 71 subjects who were biopsied in the summer or winter, and adipose expression was assessed after an acute cold stimulus applied to the thigh of physically active young subjects.
  
  
  RESULTS
  In winter, UCP1 and PGC1α mRNA were increased 4 to 10-fold (p < 0.05) and 1.5 to 2-fold, respectively, along with beige adipose markers, and UCP1 protein was 3-fold higher in the winter. The seasonal increase in abdominal SC WAT UCP1 mRNA was considerably diminished in subjects with a BMI > 30 kg/m(2), suggesting that dysfunctional WAT in obesity inhibits adipose thermogenesis. After applying an acute cold stimulus to the thigh of subjects for 30 min, PGC1α and UCP1 mRNA was stimulated 2.7-fold (p < 0.05) and 1.9-fold (p = 0.07), respectively. Acute cold also induced a 2 to 3-fold increase in PGC1α and UCP1 mRNA in human adipocytes in vitro, which was inhibited by macrophage-conditioned medium and by the addition of TNFα.
  
  
  CONCLUSIONS
  Human SC WAT increases thermogenic genes seasonally and acutely in response to a cold stimulus and this response is inhibited by obesity and inflammation.
authors.affiliation: Department of Medicine (P.A.K., B.S.F., B.Z.), Division of Endocrinology, and the Barnstable Brown Diabetes and Obesity Center, University of Kentucky, Lexington, Kentucky 40536; Division of Endocrinology (N.R.), University of Colorado Denver, Denver, Colorado 80220; Eastern Colorado Veterans Health Care System (N.R.), Denver, Colorado 80220; Department of Pediatrics (R.E.M.), University of Arkansas for Medical Sciences, Little Rock, Arkansas; College of Public Health (P.M.W.) and College of Health Sciences (E.E.D-V.), University of Kentucky, Lexington, Kentucky 40536.
authors.forename: Philip A
authors.initials: PA
authors.lastname: Kern
authors.forename: Brian S
authors.initials: BS
authors.lastname: Finlin
authors.forename: Beibei
authors.initials: B
authors.lastname: Zhu
authors.forename: Neda
authors.initials: N
authors.lastname: Rasouli
authors.forename: Robert E
authors.initials: RE
authors.lastname: McGehee
authors.forename: Philip M
authors.initials: PM
authors.lastname: Westgate
authors.forename: Esther E
authors.initials: EE
authors.lastname: Dupont-Versteegden
mesh_terms: D052438:Adipocytes, White / Q000378:metabolism; D052436:Adipose Tissue, White / Q000502:physiology*; D000328:Adult; D000368:Aged; D002478:Cells, Cultured; D004734:Energy Metabolism / Q000235:genetics / Q000502:physiology; D005260:Female; D006801:Humans; D007333:Insulin Resistance / Q000235:genetics; D007473:Ion Channels / Q000096:biosynthesis / Q000235:genetics; D008297:Male; D008875:Middle Aged; D024101:Mitochondrial Proteins / Q000096:biosynthesis / Q000235:genetics; D012621:Seasons; D050151:Subcutaneous Fat / Q000502:physiology*; D013696:Temperature; D022722:Thermogenesis / Q000502:physiology*; D015533:Transcriptional Activation / Q000502:physiology*; D000071256:Uncoupling Protein 1; D015854:Up-Regulation / Q000235:genetics / Q000502:physiology
chemical_list: D007473:Ion Channels; D024101:Mitochondrial Proteins; C000604371:UCP1 protein, human; D000071256:Uncoupling Protein 1