miR-188-3p-targeted Regulation of ATG7 Affects Cell Autophagy in Patients With Non-obstructive Azoospermia
Abstract Background: Studies have found that ATG7 knockout mice have defects in acrosome development, and the sperm formed by them are similar to human round-headed sperm. miR-188-3p expression is alleviated in the testis tissues of NOA samples. It is unclear whether ATG7 gene is related to non-obstructive azoospermia and whether miR-188-3p and ATG7 have direct target regulation relationship to affect spermatogenesis.Methods: The testicular tissues of 14 non-obstructive azoospermia (NOA) patients and 13 healthy patients were collected for basic scientific research from October 2017 to June 2018. High-throughput sequencing, qRT-PCR, Western blot, immunohistochemical staining, immunofluorescence, electron microscope, and luciferase experiment were performed to confirm the correlation between miR-188-3p and ATG7 in non-obstructive azoospermia.Results: ATG7 was highly expressed in NOA group. ATG7 protein was localized in the cytoplasm of spermatogenic cells at various levels, and the expression in NOA group was dramatically higher than that of normal individuals. After overexpression of miR-188-3p, the ATG7 3'UTR-WT luciferase activity was impeded; while the ATG7 3'UTR-MUT luciferase activity had no significant difference. LC3 and Beclin-1 gene and protein expression in the NOA samples were elevated in comparison with the normal samples; LC3 was mainly located in the cytoplasm of spermatogenic cells at all levels. LC3 and Beclin-1 genes expression after miR-188-3p overexpression were prominently in comparison with the normal samples; after miR-188-3p was inhibited, LC3 and Beclin-1 expressions were dramatically higher. The degree of LC3 punctate aggregation in the miR-188-3p mimic NC samples was greater, and that in the miR-188-3p inhibitor group was greater. The number of autophagosomes of the miR-188-3p mimic samples was less compared with the mimic NC group.Conclusion: We demonstrated here that the ATG7 gene was located in all levels of spermatogenic cells and was highly expressed in the NOA group. The expression of ATG7 gene was negatively correlated with miR-188-3p that may regulate the target gene ATG7 to participate in autophagy and affect the occurrence of NOA.