Molecular and physical interactions of human sperm with female tract secretions

[摘要] To achieve fertilisation, human sperm have to navigate and interact with the female reproductive tract (FRT) on molecular and mechanical levels. The current knowledge of some aspects of both types of interactions are limited and they were examined in this research. Proteomic analysis of crude and depleted human follicular fluid (hFF) by three proteomic approaches identified 479 hFF-proteins of which 22% were novel. A table of hFF-proteins, compiled from twenty-four hFF proteomic studies, resulted in 1586 hFF proteins; a resource for folliculogenesis and discovery of hFF biomarkers. A comparative proteomic study of media-capacitated human sperm versus capacitated sperm in the presence of hFF revealed certain hFF proteins were acquired by sperm during capacitation. Comparative metabolomics revealed some elevated metabolites in the sperm capacitation-media following 6-hour incubation compared to 1-hour swim-up, which may have relevance to sperm energy metabolism and potentially to sperm signalling mechanisms in the FRT causing remodelling for fertilisation and preparation for implantation. Sperm micro-particle image-velocimetry revealed an average fluid velocity around the motile sperm of ≤ 25- 45 μm/s and ≤ 20-35 μm/s in low and high viscosity media respectively. The averaged fluid vorticity manifested a trail of spatially confined mixing of the fluid surroundings motile sperm. To the best of our knowledge, this work is the first to conduct a comparative proteomic analysis of human sperm versus sperm-hFF interaction and to perform metabolomics analysis of human sperm capacitation media at two time points. The novel perspective of mechanical aspects of sperm motility by studying fluid velocity and vorticity around motile sperm adds a new approach to the study of sperm motility and chemotaxis. In conclusion, sperm-FRT interactions involve complex molecular and physical interactions and regulatory events. Further research of these interactions may enhance our understanding of potential applications for improved assisted reproductive techniques’ outcome and possible diagnostic approaches of infertility.

[发布机构] University:University of Birmingham;Department:Institute of Metabolism and Systems Research

[关键词] R Medicine;RG Gynecology and obstetrics