cGMP and epigenetic factor in the suppression of apoptosis in ovarian follicles

Abstract

The role of cGMP (cyclic guanosine monophosphate) in the suppression of apoptosis in preantral and preovulatory follicles has been established. But the underlying mechanisms have not yet been established. The present study has been focused on revealing the mechanisms involved in the cGMP mediated suppression of apoptosis and in survival of ovarian follicle. cGMP reduces calcium burden of the cell by mediating Ca²⁺ channels, BK (Big Potassium) channels, phosphatidylinositol 3-kinase (PI3K)/Akt pathway thus, prevents the mitochondrial membrane pore formation and apoptosis. cGMP induces the expression of Trx (thioredoxin) protein and prevents the TNF-α (Tumour Necrosis factor) induced apoptosis. cGMP also induces the expression of cytoskeleton proteins which are involved in heterogeneous distribution of mitochondria and there by reduces the Ca²⁺ burden and apoptosis. Histone 3 lysine 4 methyltransferase (MLL2) is an epigenetic factor inhibits the transcription of genes involved apoptosis which acts as co-activator of Estrogen receptor-α. In conclusion the present review predicts some mechanisms underlying the cGMP mediated suppression of apoptosis in ovarian follicles.