Research articlemiR-34a/Bcl-2 signaling pathway contributes to age-related hearing loss by modulating hair cell apoptosis

•miR-34a expression increases with age in the cochlea of a hearing loss mouse model.•Overexpression of miR-34a inhibits Bcl-2 in hair cells.•Suppression of Bcl-2 by miR-34a increases age-induced apoptosis in hair cells.

MicroRNAs, such as miR-34, have been reported to influence age-related diseases. In this study, we explored the role of the miR-34a/Bcl-2 signaling pathway in age-related hearing loss (AHL). Using an AHL mouse model (C57BL/6), we found that the expression of miR-34a in the cochlea increased with age, whereas expression of Bcl-2 decreased. Increasing the amount of a miR-34a mimetic in a mouse auditory cell line (HEI-OC1) inhibited Bcl-2, leading to enhanced apoptosis; in contrast, miR-34a inhibition produced the opposite effect. Our results support a link between age-related cochlear hair cell apoptosis and miR-34a/Bcl-2 signaling. The latter may thus serve as a potential target for AHL therapy.