NGF regulates sertoli cell growth and prevents LPS-induced junction protein damage via PI3K/AKT/NFκB signaling

Abstract

Damage to Sertoli cell junction proteins caused by inflammation can lead to male infertility. Nerve growth factor (NGF) plays an important role in reproductive and inflammatory disease; however, whether and how NGF regulates Sertoli cell function remains unclear. Here, we aimed to assess the effect of NGF on the growth of Sertoli cells isolated from the testes of dairy goats and evaluate if NGF has a protective effect on these cells. We confirmed that Sertoli cell viability, proliferation, and ATP content increased following NGF treatment. In addition, qPCR results suggested that Sertoli cell apoptosis was inhibited after NGF treatment. To investigate the protective effect of NGF on Sertoli cells under pathological inflammatory conditions, LPS was used to induce inflammatory response in Sertoli cells. Post-treatment, the entangled filamentous pseudopodia of the cells loosened and no longer spanned adjacent cells. The expression of several junction proteins (ZO-1, occludin, CX-43, β-catenin, and N-cadherin), which was down-regulated after inflammatory response induction, was restored following NGF treatment. LPS-induced changes in cytotoxicity and transepithelial electrical resistance were reversed and the intercellular connections became tighter after NGF treatment. We further demonstrated that NGF prevented the inflammatory response of Sertoli cells via the PI3K/AKT/NFκB signaling pathway, similar to the effect of the PI3K-inhibitor, LY294002, which is modified by the PI3K activator, 740Y–P. These results provide insights for devising strategies for protecting the male reproductive system and curing or preventing associated pathological conditions.