Apoptotic and Inflammatory Role of TNF‐α in Adult Rat Testis upon Ethylene Dimethane Sulfonate Treatment

Abstract

Tumor necrosis factor (TNF‐ α) is multifunctional cytokine secreted in mammalian testis by germ cells, Sertoli cells and to some extent by macrophage. TNF‐α regulates different cellular processes pertinent to spermatogenesis including steroidogenesis, germ cell apoptosis and inflammation. Inflammatory marker, IL‐1b is secreted by activated macrophages. The Fas/FasL apoptotic pathway is the current model for depletion of Leydig cells with ethylene dimethane sulfonate (EDS) treated adult rats. As TNF‐α belongs to the same cytokine family, we are investigating the role of TNF‐α in Leydig cell loss at 6, 15 and 24 hr post‐EDS. Lhr and Insl3, primarily Leydig cells markers declined by more than 85% while Hsd3b2, Leydig cell enzyme marker declined by 96% at 24 hr post‐EDS. Using TUNEL, we found 5‐fold increase in interstitial apoptotic cells at 24 hr post‐EDS. Next, genes associated with macrophage and inflammation was assayed. We observed a 2.2 fold increase in Cd163/Cd68 at 15 hr‐post EDS, suggesting an increase in testicular macrophages. Tnfa was increased 2.7‐fold at 15 hr after EDS and Il1b increased 3.3 fold, 24 hr post‐EDS. ELISA detection of TNF‐α protein in the testicular tissue showed no change in expression at 6, 15 and 24 hr post‐EDS. Immunohistochemistry for 3β‐HSD and CD163 comply with q‐PCR results. Since no change was observed in Fas and Fasl over the course of time and both the receptors CD120a and CD120b changes, we are currently studying TNF‐ α inhibitors.