The Correlation between miR-let-7b Expression, Sperm Parameters, Oxidative Stress Markers, and Hormonal Levels in...

microRNAs (miRNAs) are small, endogenous, single-stranded RNA molecules that regulate gene expression and play a role in various disease states. The let-7 family of miRNAs constitutes an important class of regulators for diverse cellular functions ranging from cell proliferation, differentiation in spermatogenesis. The aim of study review the current state of correlation between miR-let-7b expression and sperm parameters, oxidative stress markers, and hormonal levels in Oligoasthenotratozoospermia (OAT) men.

In the experimental study, RNA was extracted from the spermatozoa of 60 volunteers 30 patients with OAT and 30 controls with normal fertility (NOR). After the separating sperms, the expression level of miR-let-7b was evaluated by real time-quantitative polymerase chain reaction (RT-qPCR). The DNA fragmentation index (DFI) was measured using TUNEL assay technique. Using World Health Organization (WHO, 2010) criteria, sperm parameters were evaluated. Oxidative stress markers, i.e., total antioxidant capacity (TAC), reactive oxidative stress (ROS), and malondialdehyde (MDA), as well as hormonal profile [luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone] were determined by ELISA kit.

miR-let-7b level was significantly higher in OAT patients than the control group (P=0.008). Correlation analysis highlighted that sperm parameters (count, motility, morphology, r=-0.863, r=-0.723, r=0.875, respectively, P=0.001), TAC (r=-0.441, P=0.021), and hormonal profile (FSH; r=-0.335, P=0.027, LH; r=-0.246, P=0.034, and Testosterone; r=-0.106, P=0.036) were negatively correlated with miR-let-7b level, but positively correlated with the sperm DNA fragmentation (r=+0.691, P=0.011), ROS (r=0.376, P=0.031), and MDA (r=0.201, P=0.033).

The results of this study indicate that miRNA can have a key role in spermatogenesis and might have a diagnostic and prognostic value in men infertility. Changes in miR-let-7b level in OAT patients may be associated with the susceptibility and progression of infertility.