Impaired E-cadherin expression in human spermatozoa in a male factor infertility subset signifies E-cadherin-mediated adhesion mechanisms operative in sperm-oolemma interactions.
Cadherins comprise a family of calcium-dependent glycoproteins that function in mediating cell-cell adhesion in virtually all solid tissues of multicellular organisms. We have examined the presence of a cadherin on spermatozoon and its possible involvement in sperm-oocyte interaction. Spermatozoa from fertile human subjects showed the presence of E-cadherin on its head domains, detectable only after permeabilization of the surface membranes. On the contrary, spermatozoa from oligozoospermic subjects did not possess E-cadherin on their principal acrosomal and equatorial domains. Immunoprecipitation and Western blot studies also showed the presence of E-cadherin in spermatozoa from fertile males and its absence in oligozoospermic males. Using RT-PCR, we detected E-cadherin message in the round cells of fertile males, which was absent in the cells from oligozoospermic males. The presence of anti-E-cadherin antibody brought about quantitative reduction in the sperm-oocyte binding in vitro. These observations indicate the possibility of the interplay of a cadherin-dependent homophilic and/or heterophilic adhesion interaction between spermatozoa and oocyte during fertilization. The absence of a key adhesion molecule in a human male infertility disorder points towards genetic defects causing failure in gamete interactions.
Purohit
Sharad
S
Molecular Reproduction Unit, School of Life Sciences, Devi Ahilya University, Vigyan Bhawan, Khandwa Road, Indore 452 001, MP, India.
Brahmaraju
M
M
Palta
Abha
A
Shukla
Sunita
S
Laloraya
Malini
M
Kumar
Pradeep G
PG
D000328:Adult; D000818:Animals; D015153:Blotting, Western; D015820:Cadherins / Q000096:biosynthesis* / Q000378:metabolism; D002448:Cell Adhesion; D018076:DNA, Complementary / Q000378:metabolism; D006801:Humans; D007248:Infertility, Male; D008297:Male; D051379:Mice; D008856:Microscopy, Fluorescence; D009865:Oocytes / Q000378:metabolism; D011233:Precipitin Tests; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013084:Sperm-Ovum Interactions; D013094:Spermatozoa / Q000378:metabolism*
D015820:Cadherins; D018076:DNA, Complementary