DIRECT ACTION OF NATURAL AND SYNTHETIC PPARγ LIGANDS ON BUFFALO GRANULOSA CELL PROLIFERATION AND STEROIDOGENESIS

Fuel sensor PPAR. is known to integrate interaction between energy level and reproduction. The present study was aimed to characterize the direct effects of PPAR gamma synthetic and natural ligands on buffalo granulosa cell steroidogenesis and proliferation. The cells were cultured under serum-free conditions and treated with rosiglitazone, conjugated linoleic acid (CLA), and GW9662 (PPAR gamma antagonist). MTT assay was done to assess cell proliferation rate. The expression of key genes encoding steroid biosynthetic enzymes namely 3beta-HSD, CYP11, CYP19, StAR, PR and COX-2 was analyzed using quantitative real-time PCR. Estradiol-17 beta and progesterone content in conditioned cultured media were measured by ELISA. Both CLA and rosiglitazone significantly reduced granulosa cell proliferation. The optimsed ligand doses which were found to be increased the PPAR. expression decreased significantly the expression of CYP19, whereas CYP11 and HSD expression goes down only in cells treated with rosiglitazone. On the contrary, CLA found to be upregulate the CYP11 and HSD expression, while the expression of enzymes StAR, COX-2 and PR was significantly increased in both the treatments. Though both the ligands were found to significantly decrease the estradiol-17 beta production, increase in progesterone production was observed in CLA treated cells. Taken together, results of the present study showed that both synthetic and natural agonists of PPAR. significantly altered granulosa cells proliferation and steroidogenesis. Moreover, these endogenous and exogenous ligands significantly increased the production of PR and COX-2, suggesting that PPAR. play important role in fertility by inducing the expression of molecular markers of ovulation.