A DUAL DEATH/SURVIVAL ROLE OF AUTOPHAGY IN THE ADULT OVARY OF LAGOSTOMUS MAXIMUS (MAMMALIA- RODENTIA).

LEOPARDO, NOELIA PAOLA; VELAZQUEZ MARIELA; INSERRA, PABLO IGNACIO FELIPE; HALPERIN JULIA; DORFMAN, VERÓNICA BERTA; ALFREDO DANIEL VITULLO

Ciudad Autonoma de Buenos Aires

Congreso; Reunión Conjunta de Sociedades de BioCiencias; 2017

SAIC, SAIB, SAA, SAI, SAB, SAB, SAFE, SAFIS, SAH y SAP

The follicle reserve in the mammalian ovary is lost from the fetal/perinatal period and throughout post-natal lifespan mainly throughapoptosis-driven follicular atresia. However, other cell death mechanismssuch as autophagy, seem to be also involved. The SouthAmerican plain vizcacha, Lagostomus maximus (L.m), shows massiveovulation and a very low or suppressed apoptosis-dependentfollicular atresia. Here we investigated autophagy markers in theadult ovary of L.m aimed to discern a possible role of autophagyproteins in germ cell death or survival. A total of 14 adult female ovarieswere screened for the expression of BECLIN1, LC3B, LAMP1,cleaved CASPASE-3 and BCL2 by immunohistochemistry (IHQ),western blot (WB) and protein co-expression by confocal microscopy.The presence of autophagosomes (AP) and autolysosomes(AL) in follicles and corpora lutea (CL) was analyzed by electron microscopy(EM). Ovary explants were incubated in culture starvationmedia to determine whether autophagy was triggered by a stressstimulus. Ovary explants incubated in enriched culture media wereused as controls. Strong BECLIN1, LC3Band LAMP1 staining wasobserved in atretic follicles (AF) and degenerating CL that also expressednuclear cleaved-CASPASE-3 . Non-atretic follicles showeda slight expression of autophagy proteins but a strong expression ofBCL2 and negative expression of cleaved CASPASE-3. In culturedovaries, BECLIN1, LC3B-II and LAMP1 were significantly increasedin starvation condition (p<0,05). EM revealed a high formation of APand AL in AF and CL and a low number of autophagic vesicles in nonatretic follicles. The co-expression of LC3B-BECLIN1, LC3B-LAMP1and LC3B-CASPASE-3 was only detected in AF and CL, whileco-expression of BCL2-BECLIN1 was only observed in non-atreticfollicles. These results suggest a dual role of autophagy in the ovaryof L.m. inducing cell death in AF and CL and promoting cell survivalin non atretic follicles.