Differentiation method-dependent expression of leptin in adipocyte cell lines.
Leptin, the product of the ob gene, is expressed exclusively in adipose tissue. However, adipocyte cell lines, such as 3T3-L1 adipocytes, have generally been reported to express extremely low levels of leptin mRNA. We compared 3T3-L1's to the closely related line 3T3-F442A, and to another murine adipocyte line, TA1. TA1 cells, when differentiated by indomethacin/insulin treatment, express leptin at levels greater than those of 3T3-L1 adipocytes differentiated by the traditional methylisobutylxanthine/dexamethasone/insulin protocol. However, when 3T3-L1's are differentiated in the presence of indomethacin/insulin their expression levels of leptin increase dramatically. 3T3-F442A preadipocytes also express high levels of leptin when differentiated in the presence of T3 and insulin, but when differentiated in the presence of indomethacin/insulin, expression levels drop precipitously. These changes in leptin mRNA and protein expression are not reflected by changes in CCAAT/enhancer binding protein-alpha (c/EBPalpha), peroxizomal proliferator activated receptor-gamma (PPARgamma), lipoprotein lipase (LPL), fatty-acid binding protein aP2 or uncoupling protein-2 (UCP2) mRNA levels, and suggest a mechanism unique to the leptin gene.
Slieker
L J
LJ
Eli Lilly and Company, Lilly Research Laboratories, Indianapolis, Indiana, 46285, USA.
Sloop
K W
KW
Surface
P L
PL
D016475:3T3 Cells; D017667:Adipocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D007213:Indomethacin / Q000494:pharmacology; D007328:Insulin / Q000494:pharmacology; D020738:Leptin; D051379:Mice; D014176:Protein Biosynthesis; D011506:Proteins / Q000187:drug effects / Q000235:genetics
D007328:Insulin; D020738:Leptin; D011506:Proteins; D007213:Indomethacin