Abstract: 【Objective】This study was performed to explore the effect and molecular mechanism of nicotinamide (NIC) and rosiglitazone (RSG) on apoptosis of porcine preadipocytes for finding a novel method to control adipogenesis through regulation of preadipocyte apoptosis.【Method】Cells were cultured in high glucose DMEM medium containing 0, 0.2, 0.4, 0.6, 0.8 and 1.0 mmol•L-1 RSG. After being treated for 48 h, cells were stained with Hoechst33258 and Annexin-V-FITC/PI and observed under microscope. Simultaneously, cells were harvested for analysis of flow cytometry and collection of total protein to detect protein levels of several genes related with apoptosis. Based on the above results, cells were further co-cultured in DMEM medium containing 0, 0.1, 0.2 and 0.3 mmol•L-1 NIN with 1 mmol•L-1 RSG. After being treated for 48 h, cells were stained and observed. Cells were harvested for analysis of flow cytometry and collection of total, cytoplasmic and nuclear proteins for Western blotting analysis.【Result】RSG induced preadipocyte apoptosis by a dose-dependent way and reduced cell number. The levels of Bcl-2 and cleaved Caspase-3 increased, whereas the level of Bax decreased in higher concentration of RSG. Moreover, 0.1（P＜0.05）、0.2（P＜0.01）and 0.3 mmol•L-1 （P＜0.01）NIC significantly attenuated RSG-induced apoptosis of preadipocytes. The levels of Bcl-2 and cleaved Caspase-3 were down-regulated, whereas the level of Bax was up-regulated in treatment with 0.3 mmol•L-1 NIN + 1 mmol•L-1 RSG. Compared with the control (1 mmol•L-1 RSG + 0 mmol•L-1 NIC), in treatment with 0.3 mmol•L-1 NIC + 1 mmol•L-1 RSG, Sirt1 was transfered from cytoplasm into nucleus and the level of cleaved Caspase-3 was reduced.【Conclusion】NIC attenuated RSG-induced apoptosis of porcine preadipocytes via cytoplasm/nucleus transposition of Sirt1 and down-regulating the level of nuclear cleaved Caspase-3.

Key words: pig , nicotinamide , rosiglitazone , preadipocyte , apoptosis