Sumoylation Inhibition in Sertoli Cells Reduces Cell Viability via Apoptosis.

Abstract

Male Infertility affects 15% of couples worldwide and is a contributing factor to about 50% of cases of infertility. While sometimes attributed to certain environmental factors and genetic mutations, many cases of infertility require a deeper understanding of spermatogenesis and the necessary enzymes that promote its progression in order to diagnose and treat effectively. Recent studies have explored the unique SUMO (small ubiquitin-like modifier) protein and how it modifies post-translational proteins by sumoylation in a variety of ways. Our lab has focused on its role within the various cells in the male testes. In this study, we sought to determine importance of sumoylation specifically in the supportive somatic cells found in the testes, known as sertoli cells. Sertoli cells are known to provide nutritional, mechanical and immune support toward differentiating cells during spermatogenesis. In each experiment, we treated sertoli cell lines with the sumoylation inhibitor, ginkgolic acid at varying concentrations and analyzed the resultant cell fate. A WST-1 viability assay revealed that sertoli cells shut down when sumoylation was inhibited. Furthermore, we identified apoptosis as the particular mode of cell death initiated by these cells lacking sumoylation ability. Sumoylation, however, was not proven necessary for the proliferation of sertoli cells, which was not affected by the addition of ginkgolic acid. Future studies will explore more specific identification of SUMO targets in sertoli cells and which directly activate apoptosis.