Effect of kisspeptin on the proliferation and apoptosis of bovine granulosa cells

Previous studies have shown that kisspeptin (Kp-10) is expressed in mammalian ovaries; however, the expression and role of Kp-10 in bovine ovarian granulosa cells are still unclear. In this study, we assessed the expression of Kp-10 and its effects on the proliferation and apoptosis of bovine granulosa cells. Immunohistochemical analysis showed that Kp-10 was expressed in the cytoplasm of bovine ovarian granulosa cells. Moreover, MTT assays showed that 100 nM Kp-10 significantly inhibited the viability of granulosa cells (P < 0.05). Flow cytometry analysis showed that Kp-10 could significantly increase accumulation of cells in the G(1) phase, decrease accumulation of cells in the S phase, and promote apoptosis in bovine granulosa cells (P < 0.05). Additionally, Kp-10 decreased the mRNA levels of BcI-2, an anti-apoptotic gene; increased the mRNA levels of caspase-3, a pro-apoptotic gene; and increased the mRNA levels of Fas and Fasl(P < 0.05). Thus, our findings demonstrated for the first time that Kp-10 inhibited proliferation and promoted apoptosis in bovine ovarian granulosa cells. These findings provide insights into our understanding of the role of Kp-10 in mediating the proliferation of bovine granulosa cells.