Late-onset hypogonadism (LOH) is an age-related syndrome characterized by deficiency of serum testosterone produced by Leydig cells. Previous evidence suggested that microRNA (miR)-361-3p can serve as a promising biomarker for LOH. Nonetheless, its detailed function and molecular mechanism in LOH remain unclarified. The 24-month-old male mice were selected as an animal LOH model, and mouse Leydig cell line TM3 was stimulated with H2O2. ELISA was employed for testosterone level evaluation. Hematoxylin-eosin staining was implemented for histologic analysis of mouse testicular tissues. Western blotting and RT-qPCR were utilized for evaluating molecular protein and RNA expression, respectively. Functional experiments were conducted to test miR-361-5p roles. Luciferase reporter assay was for verifying the interaction between miR-361-5p and protein inhibitor of activated STAT 1 (PIAS1). miR-361-5p displayed a decreased level in the testes of LOH mice. Overexpressing miR-361-5p attenuated Leydig cell loss in the testis and elevated serum and intratesticular testosterone levels in LOH mice. H2O2 stimulation impaired TM3 cell viability, proliferation and intracellular testosterone production and enhanced cell apoptosis. miR-361-5p targeted PIAS1 in TM3 cell. PIAS1 upregulation counteracted miR-361-5p overexpression-mediated alleviation of cell apoptosis and elevation of testosterone synthesis in H2O2-stimualetd TM3 cells. miR-361-5p ameliorates LOH progression by increasing testosterone production and alleviate Leydig cell apoptosis via downregulation of PIAS1.
