Decrease of both stem cell factor and clusterin mRNA levels in testicular biopsies of azoospermic patients with constitutive or idiopathic but not acquired spermatogenic failure.

BACKGROUND Sertoli cells nurse germ cells during spermatogenesis, and alterations of Sertoli cell functions have been suggested in cases of spermatogenic failures. METHODS In this work, we measured stem cell factor (SCF) and clusterin mRNA levels, by quantitative RT-PCR, in RNA extracted from testicular biopsies of 49 azoospermic patients classified according to testicular histology as having normal spermatogenesis or spermatogenic failure. RESULTS When related to the percentage of Sertoli cells counted on a histological section of a neighbouring tissue sample, SCF and clusterin mRNA levels were significantly lower in the 'spermatogenic failure' group compared with the control group (P = 0.0297 and P = 0.0043, respectively). These levels were also significantly lower in the cases of 'constitutive' (cryptorchidism and Yq microdeletion) and 'idiopathic' spermatogenic failures when compared with the control group; conversely, they were not significantly decreased in the group with 'acquired spermatogenic failure' (orchitis, testicular traumatism, chemoradiotherapy and varicocele). CONCLUSIONS These data further demonstrate an alteration of Sertoli cell functions in some human spermatogenic failures and suggest that a lack of Sertoli cell maturation may be involved in cases of constitutive or idiopathic spermatogenic failures.