PPARgamma activators down-regulate the expression of PPARgamma in 3T3-L1 adipocytes.

Transcriptional activation of PPARgamma by the anti-diabetic compound troglitazone enhances the rate of 3T3-L1 adipocyte differentiation. In this study, we examined the effects of troglitazone, a specific PPARgamma ligand, on the expression of PPARgamma during and after 3T3-L1 adipocyte differentiation. Troglitazone treatment caused a significant decrease in PPARgamma proteins and DNA binding activity. This reduction was associated with a similar decrease in transcription of PPARgamma mRNA. These data suggest that in 3T3-L1 cells, the expression of PPARgamma is auto-regulated.