Isolation of up‐ or down‐regulated genes in PPARγ‐expressing NIH‐3T3 cells during differentiation into adipocytes

Adipocyte differentiation is a complex process in which the expression of many transcription factors and adipocyte‐specific genes is regulated under a strict program. The peroxisome proliferator‐activated receptor γ (PPARγ), a member of the steroid/thyroid nuclear hormone receptor superfamily of ligand‐activated transcription factors, is an important regulator of adipocyte gene expression and differentiation. In this study, we tried to identify downstream target genes of PPARγ, by using PPARγ‐expressing cells and a subtractive cloning strategy, and isolated cDNA clones which were up‐regulated or down‐regulated by PPARγ. Northern blot analyses revealed that the expression levels of the aldehyde dehydrogenase‐2‐like, type VI collagen alpha 3 subunit, cellular retinoic acid binding protein 1 and thrombospondin 1 are changed during the differentiation of mouse 3T3‐L1 preadipocyte cells, indicating that these genes might be downstream targets of PPARγ in adipocyte differentiation.