Association And Mechanism Of Jnk1 Gene Polymorphism And Susceptibility To Noise-induced Hearing Loss

Noise induced hearing loss(NIHL)has become China’s second serious occupational disease after pneumoconiosis,which has severely affected the quality of life of Chinese workers and threatened their health.At present,although the etiology of NIHL is definite,the pathogenesis of NIHL is not fully understood.There is a consensus that one of the possible pathogenesis of NIHL is that noise induces the programmed death of vestibular hair cells,which leads to irreversible damage to hearing.It has been proved in animal experiments that c-Jun N-terminal kinase 1(JNK1)in the cochlear hair cells of experimental animals could activated when they are exposed to noise.In addition,previous studies have also found that JNK1 could involved in cell proliferation,apoptosis and a series of processes.In order to reduce the health damage caused by NIHL to the working population,and to find the susceptible population of NIHL earlier,this research studied the association between JNK1 and NIHL,discovered new susceptibility biomarkers of NIHL,and explored the pathogenesis of NIHL.1.The association study of JNK1 gene polymorphism and the susceptibility of NIHL in occupational populationThis study selected 2090 workers from 5 enterprises in Jiangsu Province who were exposed to noise working environment to participate in this study.Through field epidemiological surveys method,occupational health examinations and field occupational hazardous factors detection method,collect relevant information about the research subjects and their working environment.Research subjects are screened according to uniformly prescribed inclusion criteria and exclusion criteria,and those do not meet the requirements are eliminated.According to the method of the case-control study and the results of occupational health examination,the subjects included in the study were assigned into the case group and the control group based on whether suffering from hearing loss or not.Professionally trained investigators use the questionnaire to conduct field questionnaire surveys on all subjects and collecting demographic information,occupational history,medical history,noise protection equipment usage,and family genetic diseases of the subjects.According to China’s "Diagnostic Standards for Occupational Noise Deafness"(GBZ 49-2014),surgeons with occupational disease diagnosis qualifications used pure tone hearing threshold test to test the hearing of all subjects.The clinician conducted physical examinations on all workers and collects venous blood from all subjects.Personal noise dosimeters was used to measure the noise exposure intensity in the work environment of all subjects in accordance with the measurement method of environmental noise exposure which regulated by the Chinese standard "Measurement of Physical Factors in the Workplace"(GBZ/T 189.8-2007).According to the National Center for Biotechnology Information(NCBI)(http://www.ncbi.nlm.nih.gov/)database and the Thousand Genome Project database,select the target single nucleotide polymorphism(SNP)sites in the JNK1 gene,and finally three JNK1 SNP sites,including rs9284,rs8428,and rs11598320,were selected.DNA was extracted from the collected venous blood of the research subjects,and the rs9284,rs8428,and rs11598320 gene loci of all subjects were genotyped by high-throughput Hi-SNP genotyping technology based on next-generation sequencing.The distribution of different genotypes of the SNPs of JNK1 in the case group and the control group was compared.After rigorously screening all subjects according to the inclusion and exclusion criteria,1333 workers were finally included in this study.According to the results of the pure tone hearing threshold test,the case group included 683 subjects,and the control group included 650 subjects.According to the results of statistical tests,there was no significant difference between the case group and the control group in terms of gender,age,years of noise exposure,noise exposure level,smoking,and alcohol consumption(P> 0.05).According to the results of the Hard-weinberg test,the distribution of each genotype in the control group conforms to the Hard-weinberg equilibrium(P> 0.05).Under multiple models,the distribution of different genotypes of rs11598320 was significantly different in the case group and the control group(P< 0.05).According to the results of the allele model,the T allele of rs11598320 is associated with an increased risk of NIHL(P=0.012,OR=1.27,95%CI=1.05-1.53).The results of stratified analysis showed that under the dominant model,when the noise expose years was < 16 years old or the noise level was > 92 d B,the distribution of each genotype of rs11598320 between the case group and the control group was significantly different(P <0.05).When the noise level was> 92 d B,the distribution of different rs8428 genotypes in the case group and the control group was significantly different(P <0.05),and the TT genotype is associated with a higher risk of hearing loss(OR = 1.73,95%CI = 1.11-2.70).Haplotype TCT(rs9284-rs8424-rs11598320)is associated with an increased risk of NIHL(OR = 1.30,95% CI = 1.00-1.68).The SNPs of the JNK1 gene(rs11598320 and rs8424)are related to the susceptibility of the ocupational population to NIHL.The rs11598320 TT genotype rs8428 TT genotype could be the risk factors of NIHL,and these two SNPs have the potential to become new susceptibility markers for NIHL.2.The regulatory effect of has-mi R-4695-3p on JNK1 in mouse cochlear hair cellsmi RNA is an endogenous non-coding RNA composed of approximately 22 nucleotides.Previous studies have proved that mi RNA has important functions in many physiological activities of the human body,and also plays an important role in the occurrence of diseases.mi RNA can be used as a biomarker for a variety of diseases,and can be used to reveal the pathogenesis of a variety of diseases.It has broad prospects and great potential in the application of prevention and treatment of diseases.In this study,mi RNA-4695-3p was predicted to target the SNP site rs11598320 which was found in the first part that is associated with NIHL susceptibility.This study intended to explor the regulatory effect of mi R-4695-3p on JNK1,and revealed the possible regulatory mode of mi R-4695-3p on JNK1.This study also intended to supplement the pathogenesis of NIHL and provide a new target for the treatment and prevention of NIHL.By constructing wild-type and mutant vectors of rs11598320,the dual-luciferase reporter gene experiment was used to detect the targeted regulation of mi RNA-4695-3p on JNK1.Through cell experiments,mouse cochlear hair cells were transfected with mi RNA mimics,the transcription level of JNK1 and the relative expression of mi RNA-4695-3p were detected by real-time quantitative PCR technology,and the expression level of JNK1 protein was detected by Western Blot technology.The results show that mi RNA-4695-3p can bind more tightly to the wild-type allele T of rs11598320.When HEI-OC1 cells were transfected with mi RNA mimics for 24 hours,the relative expression of mi RNA-4695-3p was up-regulated(P<0.001),the transcription level of JNK1 was down-regulated(P=0.010),and the expression level of JNK1 protein was down-regulated(P=0.021).Aafter transfection for 48 hours,the relative expression of mi RNA-4695-3p was up-regulated(P=0.030),the transcription level of JNK1 was up-regulated(P=0.013),and the expression level of JNK1 protein was up-regulated(P=0.005).In conclusion,the binding ability of mi RNA-4695-3p with different genotypes of rs11598320 locus was different,which could be the molecular basis for the difference in individual NIHL susceptibility.mi RNA-4695-3p could regulate the JNK1 signaling pathway through negative feedback regulation.