Integrated miRNA and mRNA expression profiling to identify mRNA targets of dysregulated miRNAs in non-obstructive azoospermia

The aim of this study was to identify mRNA targets of dysregulated miRNAs through the integrated analysis of miRNA and mRNA expression profiling in men with normal versus impaired spermatogenesis. The expression of mRNAs and miRNAs in testicular tissues obtained from males with non-obstructive azoospermia (NOA, n=4) or obstructive azoospermia (OA, n=3) with normal spermatogenesis was analyzed using microarray technology. Some of the most interesting results were validated by real time PCR using samples from the same cohort. Ninety-three miRNAs and 4172 mRNAs were differentially expressed in the NOA and normozoospermic OA patients. In addition to confirming that significantly dysregulated genes and miRNAs play pivotal roles in NOA, promising correlation signatures of these miRNA/mRNA pairs were discovered in this study. The functional classification of the miRNA/mRNA pairs revealed that differentially expressed genes were most frequently associated with spermatogenesis, the cell meiosis, the cell cycle, and the development of secondary male sexual characteristics. This is the first systematic profiling of both mRNA and miRNA in testicular tissues of patients with NOA and OA. Our results indicate that the phenotypic status of NOA is characterized by the dysfunction of normal spermatogenesis when compared with OA or normozoospermic males.