MiR-126-3p promotes the cell proliferation and inhibits the cell apoptosis by targeting TSC1 in the porcine granulosa cells

In mammalian ovaries, many studies demonstrated that the proliferation and apoptosis of granulosa cells are involved in folliculogenesis. Previous evidence suggests that miR-126-3p might get involved in the proliferation and apoptosis of granulosa cells, and tuberous sclerosis complex 1 (TSC1) gene was predicted as one target of miR-126-3p, and moreover, granulosa cell-specific TSC1 knockout stimulated folliculogenesis in mice. However, the molecular regulation of miR-126-3p on TSC1 and its effects on cell proliferation and apoptosis remain virtually unexplored in granulosa cells. Using porcine granulosa cells as a model, the luciferase report assay, mutation, deletion, Annexin-V/PI staining, and EdU assays were applied to investigate the molecular mechanism for miR-126-3p regulating the expression of TSC1 and their effects on the cell proliferation and apoptosis. We found that miR-126-3p showed a positive effect on cell proliferation and a negative effect on cell apoptosis in porcine granulosa cells, and knockdown of TSC1 significantly promoted cell proliferation and significantly inhibited cell apoptosis in porcine granulosa cells. Furthermore, miR-126-3p might target and repress the expressions of TSC1 at the post-transcriptional level, thereby promoting cell proliferation and inhibiting cell apoptosis of granulosa cells. These findings would provide of great insight in further exploring the molecular regulation of miR-126-3p and TSC1 on the functions of granulosa cells during the folliculogenesis in mammals.