RESUMEN
PURPOSE: To study if short-term exposure (2 h and 6 h) of endometrial/endometriotic tissues and cells to 10% seminal plasma (SP) can induce EMT/metaplasia. METHODS: Basic research experimental study was carried out in a University hospital-based fertility center. Semen samples, peritoneal fluid (PF) from endometriosis patients, endometrial biopsy from premenopausal women, immortalized endometriotic epithelial cell line (12Z), and immortalized endometrial stromal cell line (St-T1b) were studied. Rapid stain identification test (RSID), TGFß1 immunofluorescence of washed sperms, TGFß1-ELISA of SP and PF, in vitro study (2 h and 6 h incubation) and real-time PCR of endometrial tissue and cell lines to analyze gene expression of EMT/metaplasia markers and mediators were done. RESULTS: SP is still detectable in washed semen. TGFß1 was expressed on the plasma membrane of the sperms and was significantly more concentrated in SP (88.17 ng/ml) than PF. 10% SP induced an up-regulation of alpha smooth muscle actin expression in endometrial tissue (p = 0.008) and in 12Z cells (p = 0.05), mostly TGFß1-independent. TWIST expression was persistently significantly down-regulated while Snail1 and 2 were up-regulated, though insignificant. CONCLUSION: Our results provide novel evidence to support that even in semen washed twice, SP is still detectable. The changes in EMT/metaplasia markers and mediators give a new insight into a possible effect of SP on the pathogenesis of endometriosis.
