Incidence of sperm-tail tyrosine phosphorylation and hyperactivated motility in normozoospermic and asthenozoospermic human sperm samples

Our objective was to study the incidence of sperm-tail phosphotyrosine immunoreactivity in normozoospermic and asthenozoospermic human sperm samples, its association with sperm motion parameters, particularly hyperactivated motility, and its potential involvement in the pathogenesis of asthenozoospermia. The work was conducted as a prospective experimental study in the Sperm Biology and Andrology laboratories of the Jones Institute, a medical school-based fertility center. The study subjects were healthy fertile male donors (normozoospermic samples) and infertile patients (asthenozoospermic samples) attending the center. Recently ejaculated semen samples were washed twice to eliminate seminal plasma and a swim-up was performed to select the motile population which, in turn, was incubated up to 18 h at 37 degrees C in 3.5% human serum albumin-supplemented Ham's F10 to allow for capacitation. For evaluation, sperm aliquots were taken pre-swim-up (T0), immediately post swim-up (T1), at 6 h (T6), and 18 h (T18) of incubation. The main outcome measures were computer-analyzed sperm motion parameters and hyperactivated motility, and immunodetection of phosphotyrosine (PY)-containing proteins. During the capacitating incubation, normozoospermic samples displayed maximum motility, velocity, and hyperactivation at T6, significantly decreasing their values at T18. PY-proteins were located both at the tail and head of spermatozoa. Their expression increased progressively during the incubation, being present in about 70% of the sperm tails at T18. Asthenozoospermic samples showed an inability to respond to capacitation with an increase in motion parameters and PY-phosphorylation. At T6, both hyperactivation and PY-phosphorylation were significantly lower than in normal samples. Our results suggest that PY-phosphorylation of tail proteins is highly conspicuous in human spermatozoa, and increases its incidence in a time-dependent manner, as more sperm become capacitated. Asthenozoospermic samples displaying low percentages of motile sperm and altered motion characteristics showed a decreased incidence of PY-phosphorelated sperm. Tail protein PY-phosphorylation may be related to sperm movement, especially to hyperactivated motility and its deficiency may be associated to asthenozoospermia.

Orquitis autoinmune experimental / Experimental autoimmune orchitis

A pesar de los numerosos trabajos realizados en el modelo de orquitis autoinmune experimental (OAE) aún existen varias incógnitas acerca de su patogenia. Clásicamente, la OAE se indujo en cobayos utilizando como antígenos, espermatozoides u homogenado testicular. Nuestro primer interés fue determinar si antígenos no espermáticos como los componentes extracelulares de la pared del túbulo seminífero, utilizados como inmunógenos, eran capaces de inducir un cuadro autoinmune testicular. Obtuvimos, a partir del testículo de la rataÑ a) una preparación rica en membranas basales del túbulos seminífero (STBM) y b) a partir del STBM, una fracción no relacionada al componente colágeno (D-STBM) que demostró poseer determinantes antigénicos comunes con la laminina, principal glicoproteína no colágena de las membranas basales. El 50% de las ratas inmunizadas con STBM, D-STBM o laminina, desarrolaron una lesión testicular moderada, multifocal, caracterizada por leves infiltrados intersticiales, alteraciones de las membranas basales del túbulo seminífero y de la célula de Sertoli, descamación del epitelio germinal y atrofia tubular. También se detectaron anticuerpos circulantes y una respuesta de inmunidad celular específica. A su vez, ratas inyectadas con un suero heterólogo anti-D-STBM desarrollaron una lesión similar. Por otra parte, se indujo una orquitis severa inmunizando ratas Wistar con un hmogenado testicular homólogo y adyuvantes y se estudiaron las poblaciones linfáticas de los ganglios...