Regulation of sperm physiology by extracellular microvesicles from endometrial epithelial cells

FRANCHI, N.A.; CUBILLA, M.A.; GIOJALAS, L.C.

Rosario

Congreso; L Reunion Anual Sociedad Argentina de Investigacion en Bioquimica y Biologia Molecular; 2014

Sociedad Argentina de Investigacion en Bioquimica y Biologia Molecular

The uterus and oviduct synergistically induce sperm capacitation, essential process to fertilize the oocyte. Conditioned medium from an endometrial epithelial cell line (EEC) stimulates sperm capacitation, which might be regulated by extracellular microvesicles (EMV). The aims of this study were: to isolate and characterize EMV secreted by EEC; to investigate the sperm-EMV interaction; and to evaluate the effect of EMV on human sperm physiology. The EMV were obtained by ultracentrifugation and then characterized by electron microscopy and Western blot. The interaction of EMV with the cells was analyzed by incubating PKH26-stained EMV with spermatozoa, and the effect of EMV on sperm physiology, was determined by evaluating sperm induced acrosome reaction, viability and motility. The EMV had a size of 50-200 nm and showed the presence of MFGE8 protein as specific marker. After co-incubating sperm with PKH26-labeled EMV, a fluorescent staining was observed on the sperm surface, indicating membrane transference from EMV. A short time incubation of sperm with EMV-enriched medium significantly increased the induced acrosome reaction, whereas viability and motility were not affected. These results suggest that the brief transit through the uterus may contribute to the sperm acquisition of fertilizing capacity, being this process possibly mediated by the transfer of EMV to the spermatozoa.