The role of miR-199a-3p in inhibiting the proliferation of spermatogonial stem cells under heat stress.

MicroRNAs (miRNAs) play a crucial role in regulating various physiological processes, including cell differentiation, proliferation, and apoptosis. However, their specific functions in response to heat stress are not fully understood. This study aimed to investigate the regulatory effects of miR-199a-3p on the proliferation of heat stress-treated spermatogonial stem cells (SSCs). SSCs were isolated from mouse testes and cultured in vitro to identify marker molecules. Lentiviruses carrying miR-199a-3p-over, miR-199a-3p-inhibit, and ID4-over constructs were generated for stable transfection. Luciferase assay was employed to confirm the targeting relationship between miR-199a-3p and ID4. An in vitro SSCs heat stress model was established, and the miR-199a-3p-inhibit and ID4-over groups were included. Cellular proliferation was assessed using CCK-8, EdU, and cell cycle analysis methods after heat stress. Expression levels of miR-199a-3p and ID4 were evaluated by western blotting and qRT-PCR. The results demonstrated that miR-199a-3p-over inhibited SSCs proliferation, while ID4-over promoted an increase in SSCs number. Luciferase assay confirmed the regulatory effect of miR-199a-3p on ID4 expression. Moreover, after heat stress treatment, miR-199a-3p-inhibit and ID4-over enhanced SSCs proliferation compared to the control group. These findings suggest that miR-199a-3p modulates SSCs proliferation by targeting ID4, especially under heat stress conditions.