Thiols of flagellar proteins are essential for progressive motility in human spermatozoa

LANCELLOTTI, TANIA ESTEFANIA S?EZ; FORN?S, MIGUEL MATIAS; MONCLUS, MAR?A DE LOS ?NGELES; VINCENTI, AMANDA EDITH; FORN?S, MIGUEL WALTER; CABRILLANA, MAR?A EUGENIA; BOARELLI, PAOLA VANINA; SANABRIA, EDUARDO ALFREDO

REPRODUCTION FERTILITY AND DEVELOPMENT

CSIRO PUBLISHING

Lugar: Collingwood; Año: 2016

1031-3613

Male infertility is a disorder of the reproductive system defined by the failure to achieve a clinical pregnancyafter 12 months or more of regular unprotected sexual intercourse. The presence of low-motile or immotile spermatozoa isone of many causes of infertility; however, this observation provides little or no information regarding the pathogenesis ofthe malfunction. Good sperm motility depends on correct assembly of the sperm tail in the testis and efficient maturationduring epididymal transit. Thiols of flagellar proteins, such as outer dense fibre protein 1 (ODF1), are oxidised to formdisulfides during epididymal transit and the spermatozoa become motile. This study was designed to determine howoxidative changes in protein thiol status affect progressive motility in human spermatozoa. Monobromobimane (mBBr)was used as a specific thiol marker and disruptor of sperm progressive motility. When mBBr was blocked by dithiothreitolit did not promote motility changes. The analysis of mBBr-treated spermatozoa revealed a reduction of progressivemotility and an increased number of spermatozoa with non-progressive motility without affecting ATP production. Laserconfocal microscopy and western blot analysis showed that one of the mBBr-positive proteins reacted with an antibody toODF1. Monobromobimane fluorescence intensity of the sperm tail was lower in normozoospermic than asthenozoospermicmen, suggesting that thiol oxidation in spermatozoa of asthenozoospermic men is incomplete. Our findingsindicate that mBBr affects the thiol status of ODF1 in human spermatozoa and interferes with progressive motility.