title: Detection of calretinin expression in abnormal immature Sertoli cells in non-obstructive azoospermia.
abstract: The current study identified for the first time calretinin expression in abnormal Sertoli cells of azoospermic men who underwent testicular biopsy for sperm recovery and application of the retrieved sperm by in vitro fertilization techniques. Testicular biopsies with various spermatogenic impairments were evaluated immunohistochemically for the expression of the calretinin calcium-binding protein and the marker for immaturity of Sertoli cells, cytokeratin-18 (CK-18). Distribution of the markers was assessed in testes demonstrating a histological phenotype of mixed atrophy, Sertoli cell-only, or normal spermatogenesis (obstructive-azoospermia) and in men carrying a deletion in the azoospermia factor region located on the Y chromosome. Calretinin-immunopositive immature Sertoli cells revealed by co-localization of both markers, calretinin and CK-18, were identified in the mixed atrophy group in seminiferous tubules demonstrating spermatogenic failure. Sertoli cells expressing both markers were rarely detected in all other groups. Leydig cells in all the assessed biopsies expressed calretinin and served as a built-in control for immunoreactivity. This pattern of calretinin-selective expression in immature Sertoli cells suggests a functional relationship between calretinin expression and the degree of Sertoli cell differentiation. Disorders of Sertoli cell differentiation as indicated by calretinin and/or CK-18 expression contribute to the multifactorial mechanisms underlying spermatogenic failure.
authors.affiliation: Institute for the Study of Fertility, Lis Maternity Hospital, Tel-Aviv Sourasky Medical Center, 6 Weizmann Street, Tel Aviv 64239, Israel. maymonrb@bezeqint.net
authors.forename: Batia
authors.initials: B
authors.lastname: Bar-Shira Maymon
authors.forename: Haim
authors.initials: H
authors.lastname: Yavetz
authors.forename: Leah
authors.initials: L
authors.lastname: Yogev
authors.forename: Sandra E
authors.initials: SE
authors.lastname: Kleiman
authors.forename: Beatriz
authors.initials: B
authors.lastname: Lifschitz-Mercer
authors.forename: Letizia
authors.initials: L
authors.lastname: Schreiber
authors.forename: Amnon
authors.initials: A
authors.lastname: Botchan
authors.forename: Ron
authors.initials: R
authors.lastname: Hauser
authors.forename: Gedalia
authors.initials: G
authors.lastname: Paz
mesh_terms: D001706:Biopsy; D064032:Calbindin 2; D002454:Cell Differentiation; D006801:Humans; D007150:Immunohistochemistry; D007633:Keratins / Q000378:metabolism; D008297:Male; D009845:Oligospermia / Q000378:metabolism* / Q000473:pathology*; D064030:S100 Calcium Binding Protein G / Q000378:metabolism*; D012708:Sertoli Cells / Q000378:metabolism* / Q000473:pathology*
chemical_list: C576764:CALB2 protein, human; D064032:Calbindin 2; D064030:S100 Calcium Binding Protein G; D007633:Keratins