Localization of various secretory phospholipase A2 enzymes in male reproductive organs

Current evidence suggests the presence of transcripts for several secretory phospholipase A2 (sPLA2) enzymes in male genital organs. In this study, we examined by immunohistochemistry the localization of group IIA, IIC, IID, IIE, IIF, V and X sPLA2s in male genital organs. In sPLA2-IIA-deficient C57BL/6 mouse testis, sPLA2-IIC, -IID, -IIE, -IIF, -V and -X were diversely expressed in spermatogenic cells within the seminiferous tubules. Immunoblotting revealed the presence of these sPLA2s in mouse spermatozoa. In addition, sPLA2-IIF, -V and -X were localized in the interstitial Leydig cells. The same set of sPLA2s was detected in a mouse cultured Leydig cell line, and adenovirus-mediated transfer of these sPLA2s into Leydig cells resulted in increased prostaglandin production. sPLA2-IIC, -IID, -IIE, -IIF, -V and -X were also detected diversely in the epithelium of the epididymis, vas deferens, seminal vesicles, and prostate. In a sPLA2-IIA-positive FVB strain, weak expression of sPLA2-IIA was detected in Leydig cells. Notable differences in the sPLA2 expression profiles were found in the seminal vesicles and prostate between mice and humans. Taken together, individual sPLA2s exhibit distinct or partially overlapping localizations in male reproductive organs, suggesting both specific and redundant functions. [Copyright &y& Elsevier]