Figure 3.

Mitochondrial Apoptosis was Activated in Cochlear HCs After Gentamicin Treatment. A, Immunofluorescence staining results showed that TUNEL‐positive nuclei (white arrow) were increased in gentamicin‐induced hearing loss group compared to the control group in vivo experiment. Scale bars = 30 μm. B‐C, Western blotting results confirmed that the expression levels of Bax and cleaved caspase‐3 were increased in gentamicin‐induced hearing loss group compared to the control group. *P < 0.05, **P < 0.01, n = 3. D‐E, Immunofluorescence staining results showed that in vitro experiment, the expressions of cleaved caspase‐3 and TUNEL‐positive nuclei were increased after gentamicin damage compared to the untreated controls in primary culture of cochlear HCs. Scale bars = 30 μm. F‐G, Western blotting results confirmed that in primary culture of cochlear HCs, the expression levels of Bax and cleaved caspase‐3 protein were increased after gentamicin treatment compared to the untreated controls. **P < 0.01, n = 3. HC, hair cell; HEI‐OC1, House Ear Institute‐Organ of Corti 1; STK33, serine/threonine kinase 33