Regulatory Role of Sirt1 on the Gene Expression of Fatty Acid-Binding Protein 3 in Cultured Porcine Adipocytes

To investigate whether Sirt1 could modulate fatty acid-binding protein 3 (FABP3), we treated porcine adipocytes either with the Sirt1 inhibitor nicotinamide (NAM), with the Sirt1 activator resveratrol (RES), or by knockdown of Sirt1 by Sirt1-siRNA. NAM or knockdown with Sirt1-siRNA significantly inhibited Sirt1 mRNA expression, while increasing FABP3 mRNA levels. RES or RES + Sirt1-siRNA treatments further proved that Sirt1 negatively regulated FABP3 gene expression in adipocytes. We also found a similar Sirt1 regulation pattern for PPAR gamma to that of FABP3 in adipocytes. Furthermore, NAM/RES + PPAR gamma-siRNA treatments showed that Sirt1 may regulate the FABP3 gene expression partly through the PPAR gamma-mediated signals. In summary, Sirt1 regulates the expression of FABP3 gene in adipocytes, and PPAR gamma apparently plays an important role in this process. J. Cell. Biochem. 107: 984-991, 2009. (C) 2009 Wiley-Liss, Inc.