The Subunits Expression And Enzyme Activity Of Cytochrome C Oxidase In Age-related Hearing Loss Patients

Objectives:Age-related hearing loss is a common disability disease,which has a great impact on the quality of life of the elderly.The possible molecular mechanism of cytochrome c oxidase subunit Ⅰ、Ⅱ、Ⅲ in age-related hearing loss patients is found by examining the deletion mutation of mitochondrial DNA in age-related hearing loss patients and the transcription of subunits of cytochrome c oxidase in age-related hearing loss.It has a great application prospects for the research on the pathogenesis and treatment of age-related hearing loss.Methods:1、Clinical case collection was divided into experimental group of age-related hearing loss and control group of the elderly.2.1、Detection of mitochondrial DNA fragment common deletion in hair shaft.2.2、The transcriptional levels of three subunits Ⅰ,Ⅱ,and Ⅲ of cytochrome c oxidase of hair shaft were detected.3、Statistical analysis:The mitochondrial DNA 4977bp mutation is analyzed by the Fisher Exact Test analysis.The relationship between mitochondrial DNA 4977bp mutation loss and hearing loss degree was analyzed by Pearson correlation method;The relative expression of cytochrome c oxidase Ⅰ、Ⅱ、Ⅲ subunit gene was analyzed by t test;and the relationship between transcription level and hearing loss degree of three subunits of cytochrome c oxidase gene was analyzed by Pearson correlation method.Results:1、The T test analysis of the relative expression of cytochrome c oxidase I between the experimental group of age-related hearing loss patients and the control group of the elderly with normal hearing group is statistically significant(P<0.05).The relative expression of cytochrome c oxidase I decreased.Pearson’s analysis could indicate that hearing loss in the age-related hearing loss patients was correlated with the relative expression of cytochrome c oxidase I(P<0.05).2、The Fisher Exact Test analysis of mt DNA 4977bp deletion mutation in hair shaft between the experimental group of age-related hearing loss patients and the control group of the elderly with normal hearing group is statistically significant(P<0.05)..The rate of mitochondrial DNA 4977bp deletion mutation in the experimental group was 80%,and the rate of mitochondrial DNA 4977 bp deletion mutation in the control group was 10%.Pearson’s analysis could indicate that hearing loss in the age-related hearing loss patients was correlated with missing amount of mt DNA 4977bp deletion mutation(P<0.05).Conclusions:1、Cytochrome c oxidase activity decreased in hair shaft of the age-related hearing loss patients and the age-matched individuals with normal hearing.Deletion of mitochondrial DNA can cause cytochrome c oxidase subunit deletion,mainly ctochrome c oxidase I subunit deletion.2、Mitochondrial DNA deletion in hair shaft exist in the age-related hearing loss patients and the age-matched individuals with normal hearing.Mitochondrial DNA mutation deletion is one of the common causes of the age-related hearing loss.