Secretion of adiponectin and regulation of apM1 gene expression in human visceral adipose tissue.
Adiponectin (ApN) is thought to play a major role in the pathogenesis of the Metabolic Syndrome. Production of ApN and regulation of its related gene (apM1) have not yet been studied in human visceral adipose tissue. ApN was mainly associated with adipocyte membranes and abundantly secreted in medium from isolated adipocytes. apM1 gene expression, restricted to the adipocyte fraction of adipose tissue, decreased spontaneously when adipose explants were cultured in basal medium for 24 h while the expression of other adipose genes barely changed (PPARgamma, GAPDH) or increased (PAI-1). Unexpectedly, the fall of apM1 mRNA was prevented by the addition of actinomycin D, an inhibitor of transcription, or cycloheximide, an inhibitor of protein synthesis, and by reducing the amount of adipose tissue cultured per dish, thereby suggesting that a newly synthesized factor released by adipose tissue destabilizes apM1 mRNA. apM1 gene expression was also negatively regulated by glucocorticoids and positively by insulin and IGF-1. This regulation could contribute to the decreased apM1/ApN levels in insulin-resistant patients with obesity and the Metabolic Syndrome.
Halleux
C M
CM
Endocrinology and Metabolism Unit, University of Louvain, UCL 5530 Avenue Hippocrate, 55, B-1200 Brussels, Belgium.
Takahashi
M
M
Delporte
M L
ML
Detry
R
R
Funahashi
T
T
Matsuzawa
Y
Y
Brichard
S M
SM
D017667:Adipocytes / Q000187:drug effects / Q000378:metabolism; D052242:Adiponectin; D000273:Adipose Tissue / Q000378:metabolism*; D002478:Cells, Cultured; D046508:Culture Techniques; D003609:Dactinomycin / Q000494:pharmacology; D003907:Dexamethasone / Q000494:pharmacology; D005260:Female; D005786:Gene Expression Regulation; D005938:Glucocorticoids / Q000494:pharmacology; D006801:Humans; D007328:Insulin / Q000494:pharmacology; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology; D036341:Intercellular Signaling Peptides and Proteins; D008297:Male; D008875:Middle Aged; D019384:Nucleic Acid Synthesis Inhibitors / Q000494:pharmacology; D009765:Obesity / Q000235:genetics / Q000378:metabolism*; D014176:Protein Biosynthesis; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D020871:RNA Stability; D012333:RNA, Messenger / Q000096:biosynthesis; D014781:Viscera
D052242:Adiponectin; D005938:Glucocorticoids; D007328:Insulin; D036341:Intercellular Signaling Peptides and Proteins; D019384:Nucleic Acid Synthesis Inhibitors; D011506:Proteins; D012333:RNA, Messenger; D003609:Dactinomycin; D007334:Insulin-Like Growth Factor I; D003907:Dexamethasone