Nuclear factor of activated T cell (NFAT) transcription proteins regulate genes involved in adipocyte metabolism and lipolysis

NFAT involvement in adipocyte physiological processes was examined by treatment with CsA and/or GSK3 beta inhibitors (Li+ or TZDZ-8), which prevent or increase NFAT nuclear translocation, respectively. CsA treatment reduced basal and TNF alpha-induced rates of lipolysis by 50%. Adipocytes preincubated with Li+ or TZDZ-8 prior to CsA and/or TNF alpha, exhibited enhanced basal rates of lipolysis and complete inhibition of CsA-mediated decreased rates of lipolysis. CsA treatment dramatically reduced the mRNA levels of adipocyte-specific genes (aP2, HSL, PPAR gamma, ACS and Adn), compared with control or TNF alpha-treatment, whereas Li+ pretreatment blocked the inhibitory effects of CsA, and mRNA levels of aP2, HSL, PPAR gamma, and ACS were found at or above control levels. NFAT nuclear localization, assessed by EMSA, confirmed that CsA or Li+ treatments inhibited or increased NFAT nuclear translocation, respectively. These results show that NFAT proteins in mature adipocytes participate in the transcriptional control of genes involved in adipocyte metabolism and lipolysis. (c) 2007 Elsevier Inc. All rights reserved.