Expression of beta-catenin in human testes with spermatogenic defects

beta-catenin is a multifunctional molecule that functions in intercellular adhesion and signal transduction during assembly of AJs between Sertoli cells as well as between Sertoli cells and germ cells. To assess changes in the testicular beta-catenin in male infertility conditions, testicular tissues from obstructive azoospermia with normal spermatogenesis, spermatogenic arrest (SA) and Sertoli cell-only syndrome (SCO) patients were examined for immunohistochemical localization of beta-catenin. In normal spermatogenic tissue, expression of beta-catenin was largely found in the Sertoli cell-germ cell (primarily spermatocytes) contact areas. Interestingly, perinuclear localization of beta-catenin was found in spermatocytes and spermatids. In spermatogenic arrest, beta-catenin in cell contact areas between Sertoli cells and germ cells was greatly decreased, but perinuclear beta-catenin in spermatocytes was not. In SCO, weak or negligible immunoreactivity of beta-catenin was found in cell contacts between Sertoli cells. Nuclear localization of beta-catenin was found in myotubular cells in all samples. Taken together, altered expression of beta-catenin in cell contacts within the seminiferous epithelia in spermatogenic arrest and SCO suggests that interactions between Sertoli cells and germ cell are crucial for expression of beta-catenin, and thus functional development of AJs in seminiferous epithelia in human testis. It should be also emphasized that perinuclear beta-catenin in germ cells may play a specific role in spermatogenesis.