Effect of retinoid X receptor α (RXRα) on apoptosis in primary cultured porcine pre-adipocytes.

By means of semi-quantitative reverse transcription-polymerase chain reaction (semi-qRT-PCR), cell transfection, Hoechst 33342 , AO and flow cytometry methods, the apoptotic change of porcine preadipocyte treated with 9-cis retinoic acid(9-cis- RA) of retinoid X receptor α(RXRα) ligand, transfected with pEnhanced green fluorescent proteins C2-RXRα (pEGFPC2-RXRα) and RXRα-small interfering RNA (RXRα-siRNA), was investigated respectively. The morphologic change of apoptosis in treated porcine preadipocyte was observed. It appeared the cell constriction, cellular shrinkage and condensation of chromatin, pyknosis of nucleus in- to compact body firstly, and then fragmentation with completely nucleus membrane, budding and shedding continuously, at last cell turns to several apoptotic bodies enwraped with membrane in different size. Moreover, compared with control group, apoptotic rate was significantly decreased in 10 nmol/L 9-cisRA treated group, and higher in the 10 μmol/L 9-cisRA treated group (P 0.05). The expression of RXRα mRNA was significantly upregulated and downregulated when transfected with pEGFPC2-RXRα and RXRα-siRNA(P 0.05), respectively, and the apoptotic rate was significantly decreased in pEGFPC2-RXRα group while RXRα-siR- NA group significantly higher compared with control group (P 0.05). It implies that RXRα inhibits the apoptosis of porcine preadipocyte.