Reproduction Abstracts

Inhibin is a heterodimeric gonadal glycoprotein hormone belonging to the TGFβ superfamily that named for its ability to suppress FSH synthesis and secretion from anterior pituitary via a negative feedback. It can regulate proliferation, differentiation, and steroidogenesis of granulosa cells (GCs) through paracrine and autocrine manners. The objective of this study was to investigate the interaction between inhibin α subunit (INHA) and apoptosis of porcine ovarian GCs by exploring i) the effect of INHA on mitochondrial membrane potential (MMP) of GCs and ii) the effect of INHA on Caspase-3 and Bax mRAN expression in GCs. In experiment 1, GCs were divided into two groups and cultured in serum-free medium for 12 h with 0 and 50 ng/ml INHA. Then, MMP were detected under fluorescence microscopy using mitochondrial membrane potential assay kit with JC-1. Treatment with INHA induced a disappearance of red fluorescence along with a diffusion of green fluorescence into the cytoplasm of GCs. This shift of JC-1 fluorescence from red to green indicated a collapse of MMP. In experiment 2, GCs were treated with different concentration of INHA (0, 10, 20, 50, and 100 ng/ml) for 6 and 18 h. Then, total RNA was extracted, Caspase-3 and Bax mRNA were detected by qRT-RCR. The expression levels of Bax and caspase-3 were significantly increased (P<0.05) after INHA treated for 6 h. For 18 h, only treatment with 50 ng/ml INHA significantly (P<0.05) increased Caspase-3 expression. In conclusion, INHA may have a role in regulating the apoptosis of GCs through mitochondrial apoptotic pathway. This research was supported by the State Key Development Program of Basic Researchof China (No. 2011CB944203).