Downregulated miR-181a alleviates H₂O₂-induced oxidative stress and cellular senescence by targeting PDIA6 in human foreskin fibroblasts

Background: Oxidative stress is strongly associated with cellular senescence. Numerous studies have indicated that microRNAs (miRNAs) play a critical part in cellular senescence. MiR-181a was reported to induce cellular senescence, however, the potential mechanism of miR-181a in hydrogen peroxide (H₂O₂)-induced cellular senescence remains obscure.

Objective: The aim of this study is to investigate the role and regulatory mechanism of miR-181a in H₂O₂-induced cellular senescence.

Methods: Human foreskin fibroblasts (HFF) transfected with miR-181a inhibitor/miR-NC with or without H₂O₂ treatment were divided into four groups: control + miR-NC/miR-181a inhibitor, H₂O₂ + miR-NC/miR-181a inhibitor. CCK-8 assay was utilized to evaluate the viability of HFF. RT-qPCR was used to measure the expression of miR-181a and its target genes. Protein levels of protein disulfide isomerase family A member 6 (PDIA6) and senescence markers were assessed by western blotting. Senescence-associated β-galactosidase (SA-β-gal) staining was applied for detecting SA-β-gal activity. The activities of SOD, GPx, and CAT were detected by corresponding assay kits. The binding relation between PDIA6 and miR-181a was identified by luciferase reporter assay.

Results: MiR-181a inhibition suppressed H₂O₂-induced oxidative stress and cellular senescence in HFF. PDIA6 was targeted by miR-181a and lowly expressed in H₂O₂-treated HFF. Knocking down PDIA6 reversed miR-181a inhibition-mediated suppressive impact on H₂O₂-induced oxidative stress and cellular senescence in HFF.

Study limitations: Signaling pathways that might be mediated by miR-181a/PDIA6 axis were not investigated.

Conclusion: Downregulated miR-181a attenuates H₂O₂-induced oxidative stress and cellular senescence in HFF by targeting PDIA6.