Pablo E. Visconti
Research areas include mammalian sperm are not able to fertilize eggs immediately after ejaculation. They acquire fertilization capacity after residing in the female tract for a finite period of time in a process known as capacitation. Our research focused on the study of sperm signaling pathways and how they regulate the sperm ability to fertilize. As part of our investigations, we have shown that capacitation is associated with the activation of protein kinase A upstream the stimulation of protein tyrosine phosphorylation. We have conducted phosphoproteomic identification of those sequences phosphorylated during capacitation. Also, our laboratory studies other signal transduction events in sperm. Among them, we evaluate changes in sperm lipids, in the sperm membrane potential, in the intracellular pH and in intracellular calcium. As part of our interest in phosphorylation pathways, we investigate protein kinases exclusively expressed in testicular germ cells and in the sperm. These kinases are essential for spermiogenesis and we hypothesized that they are targets for male contraception.
We have recently found that increasing intracellular Ca2+ is sufficient to render the sperm fertile even when other signaling pathways such as the activation of protein kinase A or tyrosine phosphorylation are blocked. This research might be used translationally to improve in vitro fertilization protocols in humans and other species. Also at the translational level, considering that in the absence of testis-specific kinases, mice are sterile, we are conducting the search for specific inhibitors to be used as male contraceptives. At the basic levels, our laboratory is currently evaluating signaling pathways downstream the increase in intracellular Ca2+. Also, we continued with our research on phosphorylation pathways and we are currently investigating how ser/thr phosphatases are regulated as part of the acquisition of the sperm ability to fertilize.
Learn more at www.vasci.umass.edu/research-faculty/pablo-e-visconti
- PhD University of Buenos Aires, Argentina
- Postdoctoral Training: University of Pennsylvania, Philadelphia