Destabilization of acrosome and elastase influence mediate the release of secretory phospholipase A2 from human spermatozoa

Authors


Dr Jacqueline Leßig, University of Leipzig, Medical Faculty, Institute for Medical Physics and Biophysics, Haertelstrasse 16-18, Leipzig D-04107, Germany. Tel: +49-341-9715-737 Fax: +49-341-9715-709 E-mail: jacqueline.lessig@medizin.uni-leipzig.de

Abstract

Aim: To determine the cellular distribution of secretory phospholipase A2 (sPLA2) in dependence on the acrosomal state and under the action of elastase released under inflammatory processes from leukocytes. Methods: Acrosome reaction of spermatozoa was triggered by calcimycin. Human leukocyte elastase was used to simulate inflammatory conditions. To visualize the distribution of sPLA2 and to determine the acrosomal state, immunofluorescence techniques and lectin binding combined with confocal laser scanning fluorescence microscopy and flow cytometry were used. Results: Although sPLA2 was detected at the acrosome and tail regions in intact spermatozoa, it disappeared from the head region after triggering the acrosome reaction. This release of sPLA2 was associated with enhanced binding of annexin V-fluoroscein isothiocyanate (FITC) to spermatozoa surfaces, intercalation of ethidium-homodimer I, and binding of FITC-labelled concanavalin A at the acrosomal region. Spermatozoa from healthy subjects treated with elastase were characterized by release of sPLA2, disturbance of acrosome structure, and loss of vitality. Conclusion: The ability of spermatozoa to release secretory phospholipase A2 is related to the acrosomal state. Premature destabilization of the acrosome and loss of sPLA2 can occur during silent inflammations in the male genital tract. The distribution pattern of sPLA2 in intact spermatozoa might be an additional parameter for evaluating sperm quality.

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