Interrelationships Between miR-34a and FSH in the Control of Porcine Ovarian Cell Functions

Our study aimed to elucidate the effect of miR-34a mimics and miR-34a inhibitor and their combination on basic functions of ovarian cells cultured with and without FSH, and effect of FSH on expression of endogenous miR-34a. Viability, proliferation, proportion of proliferative active cells, apoptosis, proportion of DNA fragmented cells, accumulation of FSHR, steroid hormones, IGF-I, oxytocin, and prostaglandin E2 release, and expression levels of miR-34a were analysed. MiR-34a mimics decreased proliferation, apoptosis, testosterone, and estradiol output, stimulated release of progesterone, IGF-I, oxytocin, and occurrence of FSHR. MiR-34a inhibitor had an opposite effect and prevented effects of miR-34a mimics. FSH promoted expression of miR-34a, viability, proliferation, steroid hormones, IGF-I, oxytocin, and prostaglandin E2 output, and reduced apoptosis. Furthermore, miR-34a mimics supported effect of FSH on viability, apoptosis, progesterone, and IGF-I and inverted FSH action on proliferation, testosterone, and estradiol output. Our observations suggest that miR-34a can be involved in control of basic ovarian functions and that miR-34a and FSH are synergists in their actions on ovarian cell functions. Ability of FSH to promote miR-34a expression and ability of miR-34a mimics to increase occurrence of FSHR and to modify FSH effects suggest the existence of self-stimulating FSH-miR-34a axis, and that miR-34a can mediate actions of FSH on ovarian cells.