Deficient Expression of DGCR8 in Human Testis is Related to Spermatogenesis Dysfunction, Especially in Meiosis I

Introduction: DiGeorge syndrome critical region gene 8 (DGCR8) contributes to miRNA biogenesis, and defects in its expression could lead to defects in spermatogenesis. Methods: Here, we assess gene and protein expression levels of DGCR8 in the testicular biopsy specimens obtained from men with obstructive azoospermia (OA, n = 19) and various types of non-obstructive azoospermia (NOA) including maturation arrest (MA, n = 17), Sertoli cell-only syndrome (SCOS, n = 20) and hypospermatogenesis (HYPO, 18). Also, samples of men with NOA were divided into two groups based on successful and unsuccessful sperm recovery, NOA+ in 21 patients and NOA- in 34 patients. Results: Examinations disclosed a severe decrease in DGCR8 in samples with MA and SCOS in comparison to OA samples (P < 0.001). Also, the results showed DGCR8 has significantly lower expression in testis tissues of NOA- group in comparison to NOA+ group (p<0.05). Western blot analysis confirmed that the DGCR8 protein was not expressed in SCOS samples and had a very low expression in MA and HYPO samples. Discussion: The results of this survey showed that DGCR8 is an important gene for the entire spermatogenesis pathway. Moreover, DGCR8 gene plays an important role in the diagnosis of NOA subgroups, and also the expression changes in it might contribute to SCOS or MA phenotypes. This gene with considering other related genes can also be a predictor of sperm retrieval.