Omental and subcutaneous adipose tissues of obese subjects release interleukin-6: depot difference and regulation by glucocorticoid.
The purpose of this study was to determine whether human adipocytes from different depots of obese subjects produce interleukin-6 (IL-6) and whether IL-6 release is regulated by glucocorticoids. Fragments of omental and abdominal sc adipose tissue released immunodetectable IL-6 into the medium during acute incubations. Omental adipose tissue released 2-3 times more IL-6 than did sc adipose tissue. Isolated adipocytes prepared from these tissues also released IL-6 (omental > sc), but this accounted for only 10% of the total tissue release. Culture of adipose tissue fragments for 7 days with the glucocorticoid dexamethasone markedly suppressed IL-6 production. These data show for the first time that substantial quantities of IL-6 (up to 75 ng/mL) accumulate in the medium during incubations of both adipocytes and adipose tissue. Although little is known about the effects of IL-6 on adipose tissue, one action is a down-regulation of adipose tissue lipoprotein lipase. The regulated production of this multifunctional cytokine may modulate regional adipose tissue metabolism and may contribute to the recently reported correlation between serum IL-6 and the level of obesity.
Fried
S K
SK
Department of Nutritional Sciences, Rutgers University, New Brunswick, New Jersey 08903, USA.
Bunkin
D A
DA
Greenberg
A S
AS
D017667:Adipocytes / Q000187:drug effects / Q000378:metabolism; D000273:Adipose Tissue / Q000378:metabolism* / Q000473:pathology; D000328:Adult; D002478:Cells, Cultured; D003470:Culture Media / Q000378:metabolism; D003907:Dexamethasone / Q000494:pharmacology*; D005260:Female; D005938:Glucocorticoids / Q000494:pharmacology*; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism*; D008297:Male; D009765:Obesity / Q000378:metabolism* / Q000473:pathology; D009852:Omentum; D009994:Osmolar Concentration; D012867:Skin; D013997:Time Factors
D003470:Culture Media; D005938:Glucocorticoids; D015850:Interleukin-6; D003907:Dexamethasone