Expression of miR‐135a‐5p and its target gene JAK2 in spermatozoa of patients with asthenozoospermia

This study aimed to identify the molecular mechanism by which JAK2 mRNA and microRNA‐135a‐5p (miR‐135a‐5p) affect asthenozoospermia. The expression levels of JAK2 mRNA in the spermatozoa of 30 asthenozoospermia patients and 30 normal controls were detected by reverse transcription‐quantitative polymerase chain reaction (RT‐qPCR). MiR‐135a‐5p that targeted JAK2 mRNA was predicted by bioinformatics. A dual luciferase reporter vector containing miR‐135a‐5p 3′UTR was constructed. The binding of miR‐135a‐5p to JAK2 mRNA was verified by luciferase reporter assay. The protein expression levels of JAK2 and STAT3 in spermatozoa were examined by Western bolt. The relative expression levels of JAK2 mRNA and protein in the asthenozoospermia group were significantly lower than those of the normal group. MiR‐135a‐5p overexpression inhibited JAK2 mRNA and protein expression by targeting JAK2 mRNA 3′UTR. Correlation analysis showed that miR‐135a‐5p level was significantly negatively correlated with progressive sperm motility, while JAK2 mRNA level was significantly positively correlated with progressive sperm activity. Low expression of JAK2 mRNA and high expression of miR‐135a‐5p were related to asthenozoospermia and male infertility.