Presence of fibroblast growth factor receptors (FGFRs) in human sperm and their participation in acrosomal exocytosis

BUFFA GN; SAUCEDO L; ROSSO, M; GUILLARDOY T; GONGORA A; VAZQUEZ LEVIN, M; MARIN BRIGGILER, CI

Buenos Aires

Congreso; Primer encuentro rioplatense de Biologia y XIV Jornadas de la Sociedad de Argentina de Biologia; 2012

Sociedad Argentina de Biologia

FGFRs are present in several cell types and their interaction with FGF2 activates numerous signaling pathways; however, there is no evidence of their expression and function in human sperm. The aim of the study was to evaluate the presence of FGFRs in human sperm and their participation in acrosomal exocytosis (AE). Western immunoblotting and immunocytochemistry were performed with anti FGFR1, 2, 3 and 4 (Santa Cruz Biotech). The effect of FGF2 on basal AE and progesterone (Prg)-induced AE was analyzed using Pisum sativum agglutinin-FITC. Protein forms of the expected molecular weight were detected in human sperm extracts, similar to those of MCF7 and T-47D cells (controls). The FGFRs were localized in the flagellum and the acrosomal region of non-capacitated and 22-h capacitated sperm. Sperm incubation with FGF2 (1, 10 or 100 ng/ml) for 22 h led to a significant inhibition (P<0.01) of Prg-induced AE, without affecting basal AE (n=5). The addition of FGF2 to capacitated sperm also inhibited Prg-induced AE, but it significantly increased the basal AE (n=8). These effects were blocked by a FGFR inhibitor (PD173074, 0.1 µM). In conclusion, FGFRs are present in human sperm and have a modulatory effect on the AE.