Differential expression of miR-23a/b-3p and its target genes in male patients with subfertility

Objective: To elucidate the potential regulatory function of miR-23a/b-3p on spermatogenesis-specific genes.

Design: Reverse transcription quantitative polymerase chain reaction (RT-qPCR) validation, Northern blot, dual luciferase assay, and Western blot confirmation.

Setting: University research and clinical institutes.

Patient(s): A total of 115 men presenting at an infertility clinic.

Intervention(s): None.

Main outcome measure(s): Significant higher abundance levels of miR-23a/b-3p and lower abundance levels of PFKFB4, HMMR, SPATA6, and TEX15 in oligoasthenozoospermic men compared with those in normozoospermic men.

Result(s): In oligoasthenozoospermic men, the abundance levels of miR-23a/b-3p were significantly higher when compared with controls as determined by RT-qPCR. After in silico prediction of potential targets of miR-23a/b-3p, PFKFB4, HMMR, SPATA6, and TEX15 have been identified as direct targets by dual luciferase assays. Mutations in the miR-23a/b-3p binding site within the 3'UTRs resulted in abrogated responsiveness to miR-23a/b-3p. PFKFB4, HMMR, SPATA6, and TEX15 mRNA and HMMR and SPATA6 protein levels were significantly lower in oligoasthenozoospermic men compared with in normozoospermic men. Correlation analysis showed that the sperm count, motility, and morphology were negatively correlated with miR-23a/b-3p and positively correlated with PFKFB4, HMMR, SPATA6, and TEX15 abundance levels (lower ΔCt, the higher abundance levels).

Conclusion(s): This study establishes a link between up-regulation of miR-23a/b-3p and the coincident down-regulation of four expressed genes in the sperm of men with oligoasthenozoospermia, compared with men with normozoospermia. This study provides a novel insight into some of the mechanisms leading to male subfertility, offering a possible therapeutic target for treatment, or even for male contraception.