The Expression and Roles of Semaphorin Type 3C in Granulosa Cells during The Luteinization Process

Abstract

Morphological changes are observed during the luteinization process of granulosa cells, however mechanisms and the roles are remained unclear. In the present study, we demonstrated that Sema3C is expressed in granulosa cells and then secreted to extracellular matrix accumulated within cumulus cell and granulosa cell layers. The expression is dependent on EGF-like factors (amphiregulin and neuregulin 1) and EGF receptor dependent manner. The knockdown of Sema3c not only significantly decreased the surface area of the granulosa cells, but also significantly suppressed the cell migration of granulosa cells cultured with EGF like factors. The phosphorylation of focal adhesion kinase (FAK) was dramatically suppressed by transfection with Sema3c siRNA, with an increasing level of phosphorylated ROCK, indicating that Sema3C regulated actin remodeling in a FAK signaling pathway-dependent manner. Moreover, the expression levels of genes involved in progesterone production, Star; Cyp11a1 were significantly decreased in Sema3c siRNA-transfected granulosa cells as compared with control siRNA transfection. From these results, we conclude that Sema3C is secreted and then accumulated within granulosa cell layers and cumulus cell layers. The FAK pathway is activated by Sema3C and induces cell migration and enlarges the area of granulosa cells. These morphological changes are required for luteinization (production of progesterone) of granulosa cells.