Adipocyte differentiation and nuclear receptor]

The roles of nuclear receptors in differentiation and function of adipocytes were reviewed and discussed. Expression of peroxisome proliferator-activated receptor (PPAR) gamma have been reported to be strongly induced during adipocyte differentiation and maintained in matured adipocytes. Forced expression of PPAR gamma converted NIH3T3 fibroblasts to adipocytes, indicating PPAR gamma regulates essential genes to obtain the adipocyte phenotype. Newly developed antidiabetic thiazolidinediones known as high affinity ligands for PPAR gamma improved insulin resistance. This finding suggests that PPAR gamma contributes regulation of insulin action. Several genes regulated by troglitazone, one of the most potent thiazolidinediones, in matured 3T3-L1 adipocytes-were obtained by differential display PCR method. Orphan receptors ROR alpha/gamma and Rev-ErbA which bind to the same response element are also induced during adipocyte differentiation but their function is still to be investigated.