Investigation of CD133 and CD24 as candidate azoospermia markers and their relationship with spermatogenesis defects

Abstract Spermatogenesis is initiated when spermatogonial stem cells (SSCs) in the mature testes enter mitosis and trigger differentiation. Thus, spermatogenesis and the ability to maintain a continuous source of spermatogonia relies on the ability to differentiate SSCs. Many studies around the world have been performed to investigate the etiology of male infertility and recent studies have focused on the presence and identification of biomarkers. CD133 and CD24 are stem cell markers locating in the testis and spermatogonia. The aim of this study was to investigate the relationship of the CD133 and CD24 genes with spermatogenesis defects and examine them as a candidate a useful biomarker for azoospermia men. The association of CD133 and CD24 with spermatogenesis defects was investigated in patients with obstructive (O) and non-obstructive azoospermia (NOA). NOA cases were histopathologically classified into Hypospermatogenesis (HS), Maturation Arrest (MA), and Sertoli Cell Only Syndrome (SCO) groups. A qRT-PCR analysis of these genes was performed and protein expression levels were measured by Western blot analysis. CD133 expression in NOA group was found to be significantly different from OA and this was confirmed by immunohistochemistry and immunocytochemical assays. The qRT-PCR analysis revealed that gene expression of CD133 and CD24 had fold changes of 0.80 ± 0.34 and 1.59 ± 0.31 compared to controls, respectively in the HS group (p > 0.05) and 0.04 ± 0.01 and 0.54 ± 0.08 in the MA group (p   0.05). CD133 gene expression was not detected at the transcriptional level in the SCO group. Western blot analysis of CD133 protein expression revealed 1.83, 4.11, and 11.4-fold decreases in the HS, MA and SCO groups, respectively, compared to controls (p