Regulation of capacitation of XXXX spermatozoa during co-culture with heterologous oviductal epithelial cells.

@entity235 @entity4149 @entity3158 @entity3157
Progress of essential steps of the capacitation is coordinated in the oviductal isthmus, where sperm are stored in close contact with the epithelium. A crucial capacitational event is the phosphorylation of sperm membrane proteins. Regulation of the @entity4149 phosphorylation by the oviduct has not been examined in @entity235 sperm yet. The aim of this work was to study the effect of @entity235 sperm binding to porcine oviductal epithelium on capacitation-induced cellular and molecular changes. Epithelial cells were stripped from the oviducts of post-puberal sows and cultured for 5-7 days at 39 degrees C and 5% @entity3158 on Biomatrix-covered Chamber slides. Sperm washed through Percoll was co-incubated with the oviductal epithelium cell cultures in a @entity3157 Tyrode's medium. During co-incubation, sperm membrane changes, the state of @entity4149 phosphorylation and motility were determined after 3, 30, 90, 180, 240 and 360 min. Significant increases in the percentage of capacitated and dead cells were observed in unbound sperm, while bound sperm remained uncapacitated, live and motile. An increasing @entity4149 phosphorylation of tail proteins in bound, unbound and control sperm suspensions and a subsequent phosphorylation of head proteins in unbound and control sperm suspensions were observed. A significant difference regarding head phosphorylation (p < 0.05) was found between sperm bound to oviductal epithelium and unbound sperm. Binding occurred mainly in sperm with non- phosphorylated heads, while higher proportions of phosphorylated cells were found in unbound populations. The head phosphorylation progressed significantly during incubation in unbound spermatozoa (p < 0.05); however, it was suppressed in population of sperm attached to oviductal epithelium. Significant correlations between motility parameters related to hyperactivation and tail phosphorylation were found in unbound sperm. These observations support the hypothesis that spermatozoa with non-phosphorylated heads preferentially attach to epithelial cells. It can be concluded that @entity4149 phosphorylation of head membrane proteins and capacitation are delayed in @entity235 spermatozoa being in closed contact with oviductal epithelium.
