Presence of Epithelial and Neural cadherin in human gametes and their involvement in adhesion events during fertilization

VEIGA, MARÍA FLORENCIA; MARIN-BRIGGILER, CLARA ISABEL; GONZALEZ-ECHEVERRIA, MARÍA FERNANDA; LAPYCKYJ, LARA; VAZQUEZ-LEVIN, MÓNICA HEBE

Barcelona, España

Congreso; 9th International Congress of Andrology; 2009

International Society of Andrology

<!-- /* Font Definitions */ @font-face {font-family:"Cambria Math"; panose-1:2 4 5 3 5 4 6 3 2 4; mso-font-charset:0; mso-generic-font-family:roman; mso-font-pitch:variable; mso-font-signature:-1610611985 1107304683 0 0 159 0;} @font-face {font-family:"Arial Narrow"; panose-1:2 11 6 6 2 2 2 3 2 4; mso-font-charset:0; mso-generic-font-family:swiss; mso-font-pitch:variable; mso-font-signature:647 2048 0 0 159 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-unhide:no; mso-style-qformat:yes; mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman","serif"; mso-fareast-font-family:"Times New Roman"; mso-fareast-language:ES;} p.MsoBodyText, li.MsoBodyText, div.MsoBodyText {mso-style-unhide:no; mso-style-link:"Texto independiente Car"; margin:0cm; margin-bottom:.0001pt; text-align:justify; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Arial Narrow","sans-serif"; mso-fareast-font-family:"Times New Roman"; mso-bidi-font-family:"Times New Roman"; mso-ansi-language:EN-GB; mso-fareast-language:ES;} span.TextoindependienteCar {mso-style-name:"Texto independiente Car"; mso-style-unhide:no; mso-style-locked:yes; mso-style-link:"Texto independiente"; mso-ansi-font-size:12.0pt; mso-bidi-font-size:12.0pt; font-family:"Arial Narrow","sans-serif"; mso-ascii-font-family:"Arial Narrow"; mso-hansi-font-family:"Arial Narrow"; mso-ansi-language:EN-GB; mso-fareast-language:ES;} .MsoChpDefault {mso-style-type:export-only; mso-default-props:yes; font-size:10.0pt; mso-ansi-font-size:10.0pt; mso-bidi-font-size:10.0pt;} @page Section1 {size:595.3pt 841.9pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:35.4pt; mso-footer-margin:35.4pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> Cadherins are calcium-dependent cell-cell adhesion molecules that have an essential role in embryonic development, maintenance of tissue structure and tumorigenesis; however, their participation in fertilization remains unknown. Objectives: To characterize the presence and localization of Epithelial (E-cad) and Neural (N-cad) cadherin proteins and members of the adhesion complex (b-catenin and actin) in human gametes and to assess their involvement in sperm-oocyte interaction. Methods: Protein expression in gametes was evaluated by Western immunoblotting and immunocytochemistry; their participation in fertilization was determined by assessing the ability of specific antibodies to interfere gamete interaction in in vitro assays. Results: E-cad, N-cad, b-catenin and actin were detected in sperm protein extracts; these proteins were localized to the acrosomal region of ejaculated and capacitated spermatozoa. In cells that had undergone acrosomal exocytosis, a weak signal for E-cad was detected on the whole head and a strong N-cad labelling was found over the equatorial segment. Moreover, both adhesion proteins were immunodetected on the surface of the human oocyte, and E-cad signal was also observed in the zona pellucida (ZP). Sperm preincubation with specific anti E-cad antibodies significantly inhibited binding to homologous ZP (p<0.05); contrasting, no inhibitory effect was observed when spermatozoa were treated with anti N-cad antibodies. Presence of both anti E-cad and N-cad antibodies significantly affected penetration of human spermatozoa to ZP-free hamster eggs (p<0.05). Comments/conclusions: E-cad, N-cad and members of the cadherin adhesion complex are present in human gametes. While E-cad would participate in sperm-ZP binding, both molecules would have a role during sperm-oolemma adhesion/fusion events.