Protein Profile of Capacitated versus Ejaculated Human Sperm

Abstract

Freshly ejaculated sperm acquire the fertilizing potential by a continuing process that occurs during sperm transport through the female genital tract, and it is physiologically not complete until the spermatozoon reaches the oocyte. The process termed capacitation can be mimicked in vitro by using appropriate capacitation media. Despite its importance, the molecular mechanisms underlying capacitation are poorly understood. This work deals with a proteomic approach to the analysis of protein profile variations in human normospermic samples as a consequence of three hours in vitro capacitation. 2DE gels were produced per freshly ejaculated sperm and per capacitated sperm and several quantitative and qualitative significant variations were found. Among the MS obtained identifications, proteins with a significant decrease after capacitation were found to be involved in protein fate, metabolism, and flagellar organization; on the contrary, increasing proteins were found to be related to cellular stress. Interestingly, the detected flagellar organization proteins decreased during capacitation whereas their corresponding fragments increased. A swim-up selected and three-hour capacitated sperm subpopulation has also been resolved by 2DE, and its synthetic gel has been analyzed for the variations observed in the entire sperm population. An immunofluorescence analysis of this sperm typology was carried out with antiactin and antitubulin antibodies.

Electrophoretic and zymographic characterization of proteins isolated by various extraction methods from ejaculated and capacitated boar sperms

“…Similar studies were done by Secciani et al [27], who compared protein profiles of ejaculated and 3-h capacitated human normospermic samples. The authors reached the analogical conclusion that several significant quantitative and qualitative variations were found.…”

Label-free protein quantification in freshly ejaculated versus post-mating spermatophores of the noble crayfish Astacus astacus

“…Down-regulation of actin has been reported in human capacitated spermatozoa [28]. The reason for post-mating down-regulation of actin in the crayfish male gamete is yet to be investigated.…”

Proteomics of spermatogenesis: from protein lists to understanding the regulation of male fertility and infertility

“…Other studies have also revealed a similar number of proteins. [44][45][46] These recent global analyses of human sperm are landmark studies and provide rich resources for exploring normal sperm physiology, including sperm motility.…”