ACTIVATION OF FIBROBLAST GROWTH FACTOR RECEPTORS (FGFRs) AND RELATED SIGNALING PATHWAYS IN HUMAN SPERM

SAUCEDO L; GONGORA A; VAZQUEZ LEVIN, M; MARIN BRIGGILER, CI

Chascomus

Congreso; XV Jornadas Anuales de la Sociedad Argentina de Biología; 2013

Sociedad Argentina de Biología

ACTIVATION OF FIBROBLASTGROWTH FACTOR RECEPTORS (FGFRs) AND RELATED SIGNALING PATHWAYS IN HUMAN SPERMSaucedo L,Góngora A, Vazquez-Levin MH, Marín Briggiler CI.IBYME-CONICET-UBA,Buenos Aires, Argentina.In somatic cells, FGFRsmodulate several cellular functions by the activation of signaling pathwaysthat involve the phosphorylation of FGFRs, MAPK/ERK and PI3K/Akt. Previousstudies from our laboratory have shown the presence of FGFRs in human sperm,although there is no evidence of their functionality. The aim of the present studywas to analyze FGFRs, ERK and Akt activation in human sperm in response to theligand (FGF). Sperm were incubated under capacitating conditions for total 4 h andexposed to FGF (1, 10 or 100 ng/ml) during the last 15 min. FGFRs, ERK and Akt phosphorylationwas evaluated by immunocytochemistry and Western immunoblotting using specificantibodies against the phosphorylated forms. The 27±4 % of the 4-h capacitatedsperm showed phosphorylation of flagellar FGFRs and the exposure to 10 and 100ng/ml FGF led to a significant increase (P<0.05) in the percentage ofimmunoreactive cells (44±2 % and 57±3 %, respectively; n=3). In sperm treatedwith FGF, an increase in flagellar ERK and Akt phosphorylation was alsoobserved (n=6). These effects were blocked when sperm were preincubated for 15min with a FGFR specific inhibitor (BGJ398). In conclusion, sperm FGFRs arefunctional since exposure to the ligand induces their phosphorylation and theactivation of the ERK and Akt signaling pathways. Supported by grants from FundaciónFiorini (2012, CIMB) and CONICET (PIP2120, MHVL).