Objective      To observe the relationship between mitochondrial transcription factor B1 (TFB1M) and hair cell apoptosis of cochlear neurosensory epithelia in mice with neomycin-induced auditory epithelium damage in vitro.       Methods      The cochlea of newborn ICR mice was used for in vitro culture of auditory epithelia

which were divided into a control group and a neomycin damage group. The TFB1M expression in the auditory epithelia and mitochondria on 4

12

and 24 h after damage and 2 d after elution were detected

and the mitochondrial membrane potential and hair cell apoptosis of cochlear neurosensory epithelia were analyzed.       Results      On 4 h after neomycin treatment

the shape of hair cells in the middle turn was intact

but the mitochondrial membrane potential began to decrease. On 12 h after neomycin treatment

most of the hair cells in the middle turn and basal turn were lost

and the mitochondrial membrane potential of the remaining hair cells was obviously decreased. Meanwhile

the TFB1M expression was up-regulated significantly in cell nuclei and mitochondria (P0.01). On 24 h after neomycin treatment

almost all the hair cells in the middle turn and basal turn were lost

and the mitochondrial membrane potential disappeared. On 2 d after elution

the TFB1M expression was decreased

and the hair cells in the basal membrane were not further lost. In contrast

the hair cells in the control group showed intact shape

regular arrangement and no change of mitochondrial membrane potential.       Conclusion      The elevated expression of TFB1M protein may lead to the mitochondrial dysfunction and hair cell apoptosis

which has potential significance in prevention and treatment of neomycin-induced deafness.