Apoptosis en la atresia folicular y la regresión del cuerpo lúteo. Revisión

Abstract

This review analyzes the primary molecules involved in survival and in apoptotic death of antral follicle and corpus luteum (CL) cells. Gonadotropins, estrogens and growth factors such as IGF-I and VEGF, must be present in the follicular environment for follicles to remain healthy. While progesterone, LH and the growth factors mentioned above are vital for CL cells and for ovarian cell apoptosis. A large number of molecules participate in these processes, particularly: Fas/FasL and other members of the tumor necrosis factor (TNF) family and their ligands, pro-apoptotic members of the Bcl-2 protein family (Bax, Bok, Bim, Bad and Bid), cytochrome c, apoptosis-inducing factor (AIF), apoptotic protease activating factor 1 (Apaf-1), p53, initiator caspases (1, 8 and 9), effector caspases (3, 6 and 7), Smac/Diablo and the inhibitor of apoptosis proteins (IAPs). A follicular environment with low survival factor levels increases Fas expression and its interaction with ligand FasL in follicular cells, which results in apoptotic death, however, this inadequate environment can also cause the release of pro-apoptotic proteins from the mitochondrion. Apoptosis in luteal cells is induced by PGF2-a, which increases the expression of pro-apoptotic members such as Bax and death receptors (RTNF-alpha,,,).