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Insulin and glucocorticoids differentially regulate leptin transcription and secretion in brown adipocytes
Author(s) -
Buyse Marion,
Viengchareun Say,
Bado AndrÉ,
LombÈs Marc
Publication year - 2001
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fj.00-0669com
Subject(s) - leptin , medicine , endocrinology , adipose tissue , insulin , leptin receptor , biology , hormone , adipocyte , secretion , autocrine signalling , receptor , obesity
Leptin, the ob gene product, is produced by adipose tissue and is submitted to a complex hor¬monal and metabolic regulation. Leptin plays a critical role in the balance of body weight. Here we report on secretion and hormonal regulation of leptin by brown adipocytes. Using the recently established T37i cell line, we show that leptin expression and secretion occurred as a function of cell differentiation. In differ¬entiated T37i cells, insulin induced leptin release (~0.25 ng/10 6 cells/h) in a concentration‐dependent manner (EC 50 =0.1 nM), and this was totally suppressed by β 3 ‐adrenergic ligand, thiazolidinedione, cycloheximide, or actinomycin D. Insulin induced a strong, rapid (within 2 h) but transient fivefold increase in leptin mRNA levels. This transcriptional control of ob gene expression by insulin involved both phosphatidylinositol 3‐kinase‐ and MAP kinase‐dependent pathways. Glucocorticoids inhibited both insulin‐stimulated leptin secretion and ob gene expression without affecting leptin mRNA stability (t 1/2 =3h05). Altogether, our results demonstrate that brown adipocytes express and secrete leptin, whose hormonal regulation clearly dif¬fers from that described in white adipose tissue. These findings point to tissue‐specific molecular mechanisms and suggest that leptin might exert direct effects on energy homeostasis through an autocrine mecha¬nism.—Buyse, M., Viengchareun, S., Bado, A., Lombès, M. Insulin and glucocorticoids differentially regulate leptin transcription and secretion in brown adipocytes. The FASEB J. 15, 1357–1366 (2001)