Localization of adhesion molecules on human spermatozoa by fluorescence microscopy

Abstract

The expression of adhesion molecules on human spermatozoa of healthy probands was analysed. The localization patterns of adhesion molecules (AM) on the spermatozoal surface were documented by fluorescence microscopy. Spermatozoa were incubated with antibodies against a1 (CD49a), a2 (CD49b), a 3 (CD49c), a4 (CD49d), a5 (CD49e), a6 (CD49f) chains of pl integrins, 81 (CD29), p2 (CD18), aV (CD51), p3 (CD61) and p4 integrin chains, the LFA-3 (Lymphocyte function antigen, CD58) from the immunoglobulin superfamily and the extracellular matrix proteins laminin, fibronectin and collagen IV. For collagen IV, a1 and a2 chains no expression could be noticed. Laminin was detected at the acrosomal membrane, fibronectin and p4 chain mainly at the equatorial membrane. The fibronectin receptors a3, a4 and a5 chains of the p 1 integrins were mainly located on acrosomal and equatorial membrane areas. Laminin receptor a6 chain was located postacrosomal and less frequently acrosomal. p2 chain and vitronectin receptors aV and p3 chains had a mainly postacrosomal localization pattern. LFA-3 was found constantly on postacrosomal membrane areas. Double staining technique was used to prove the simultaneous occurrence of fibronectin and its integrin receptors a3, a4 and a5 chains and of aV and p2 chains on spermatozoa. The localization patterns of integrins on double stained spermatozoa were similar to the patterns described for single stained spermatozoa. The localization of fibronectin appeared to be influenced by the presence of integrins: the typical equatorial fibronectin band disappeared in case of an equatorial localization of integrins.

Effects of natalizumab, an α4 integrin inhibitor, on fertility in male and female guinea pigs

“…In males, α4 integrins can be detected on spermatozoa after epididymal transit (Glander et al, 1994) but not at any of the precursor stages of development (Schaller et al, 1993; Shinohara et al, 1999). On spermatozoa, α4 was located mainly in acrosomal and equatorial membrane areas (Trübner et al, 1997), and, following the loss of the acrosome, α4 was expressed at a significantly higher level in fertile sperm samples compared with infertile ones (Glander et al, 1996). However, there are no published studies to date demonstrating that α4 on expression on sperm is a necessary condition for fertilization to occur.…”

Overexpression of CD61 promotes hUC‐MSC differentiation into male germ‐like cells

“…Cells were resuspended for 16 h, and EBs formed after a further 3 days. Appropriate EBs were added to 96‐well plates and 12‐well plates; after adherence overnight, culture medium was replaced with induction medium, which was changed every 2 days .…”

“…HOECHST33342 (Sigma) was used to stain cell nuclei, 3 min at room temperature (RT), after being rinsed twice for 3 min in PBS. Cells were then examined using a fluorescence microscope .…”

“…CD61, also known as integrin‐β3, is a variety of adhesion receptor, widely distributed on surfaces of cells, participating in cell signalling pathways of molecular and protein information transmission, across cell membranes, to regulate bodily physiology. Some scientists have found that it plays a key role in embryonic development, immunological responses and sperm maturation . Integrin‐β3‐ and SSEA‐1‐positive cells are very similar with BV (Blimp and Stella) positive .…”