α1-antitrypsin prevents polymorphonuclear leucocyte-elastase effects on spermatozoa quality

Abstract

Elevated levels of polymorphonuclear leucocyte (PMN)-derived elastase, which is suggested as marker for inflammations in the male genital tract, correlate well with spermatozoa deterioration. PMN elastase caused a time- and concentration-dependent (up to a elastase concentration of 0.5 μg/mL) externalization of phosphatidylserine and intercalation of propidium iodide on human spermatozoa. There are apparently a limited number of target sites for elastase on spermatozoa surface, because the further enhancement of elastase amount did not fasten alterations in spermatozoa parameters. Analysis of flow cytometry data revealed that most spermatozoa were in a necrotic state after an exposure with elastase for 22 h. Some apoptotic cells were only detected at shorter incubation periods. Seminal plasma prevented in a concentration- dependent manner the PMN elastase-mediated loss of vitality of spermatozoa. We detected by blotting techniques large amounts of α1-antitrypsin in seminal plasma. This antiproteinase is known to inactivate elastase at inflammatory sites. Increasing concentrations of α1-antitrypsin prevented gradually spermatozoa deterioration induced by elastase. Thus, α1-antitrypsin contributes to an efficient protease/ antiproteinase balance in seminal plasma. A disturbed balance will promote the development of chronic inflammations which can also be the reason for male infertility problems. © 2010 European Academy of Andrology.