Altered expression of b-catenin and vimentin in testes of male infertile patients.

Abstract

Introduction In the testis is found in actin-based adherens junctions (AJs) among Sertoli cells, as well as between Sertoli and germ cells. Cell-cell intermediate of junctions between Sertoli and germ cells not only provide mechanical adhesion of germ cells onto Sertoli cells, but also play a crucial role in germ cell morphogenesis and differentiation. -catenin a multifunctional molecule with important roles in intercellular adhesion and signal transduction was detected during assembly of AJs between Sertoli cells as well as between Sertoli cells and germ cells. In testis, vimentin intermediate filaments occur in the perinuclear region of the Sertoli cell and ectoplasmic specialization junctions found between Sertoli cells and more advanced germ cells. To date, however, neither expression of -catenin and vimentin in human testis nor changes in their expression in abnormal spermatogenesis tissues was elucidated. In an effort to elucidate the involvement of -catenin and vimentin in human spermatogenesis the expression of -catenin / vimentin was examined in the testes of male infertility patients.

Materials and Methods Human testicular tissues obtained from patients who had given their consent were used for experiment. The testis tissue was stained with haematoxylin and eosin in the standard fashion for histological evaluation. After histological evaluation, testicular tissue was classified by normal spermatogenesis, spermatogenic arrest and Sertoli cell-only syndrome was used in this study. Testis tissues were examined for immunohistochemical localization of -catenin, and vimentin. Each patients Serum concentrations of FSH were analyzed by radioimmunoassay using a commercial assay kit.

Results In normal tissue, -catenin was found in the inter-Sertoli and Sertoli-germ cell (primarily spermatocytes) contact areas. Vimentin was found in the Sertoli cell. In spermatogenic arrest and Sertoli cell-only syndrome, however, there was relatively low or negligible expression of -catenin and vimentin. Plasma FSH levels were significantly higher in the SCO group than that in the normal spermatogenesis.

Conclusions -catenin plays important roles in cell adhesion in AJs at the plasma membrane and in many aspects of signaling during cell proliferation and development. Expression of -catenin and vimentin in germ cells as well as Sertoli cell in normal testis and decreased or no expression in spermatogenic arrest and Sertoli cell-only syndrome suggest that paracrine interactions between Sertoli cell and germ cell are important for proper regulation of expression of -catenin / vimentin and thus functional development of AJs in human seminiferous tubule. It is also suggested that -catenin / vimentin expression is closely related to spermatogenic dysfunction in human testis.