Xiuting Li

Lack of association between DNMT1 gene polymorphisms and noise-induced hearing loss in a Chinese population

DNA methyltransferase 1 (DNMT1) plays a crucial role in maintaining of methylation and chromatin stability. And mutations in DNMT1 can induce one form of neurodegenerative diseases with dementia and sensorineural hearing loss. To assess whether single nucleotide polymorphisms (SNPs) or haplotypes of DNMT1 are related to noise-induced hearing loss (NIHL) in a Chinese population, we genotyped three functional polymorphisms (rs12984523, rs16999593, and rs2228612) in a case-control study involving 615 NIHL cases and 644 controls. However, no significant association was detected between these three SNPs and NIHL susceptibility in the Chinese population. Our data suggested that the DNMT1 polymorphisms may not contribute to risk of NIHL in the Chinese population.

Association between Paraoxonase 2 Gene Polymorphisms and Noise-induced Hearing Loss in the Chinese Population

Association between Paraoxonase 2 Gene Polymorphisms and Noise‐induced Hearing Loss in the Chinese Population: Xiu‐Ting LI, et al. Department of Occupational Medicine and Environmental Health, Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, China—

PON2 and ATP2B2 gene polymorphisms with noise-induced hearing loss

BACKGROUND Noise-induced hearing loss (NIHL) is a complex disease induced by a combination of genetic and environmental factors. Paraoxonase2 (PON2) gene involved in the regulation of reactive oxygen species, and affecting the vulnerability of cochlea to NIHL, and ATPase, calcium-transporting, plasma membrane 2 (ATP2B2) gene which encodes plasma membrane calcium-transporting ATPase isoform 2 (PMCA2) are the candidate genes relating to the attack of NIHL. In this study, we investigated whether ATP2B2 and PON2 polymorphisms were associated with NIHL in Chinese of Han nationality population. METHODS We performed a case-control study between six single nucleotide polymorphisms (SNPs) (rs1719571, rs3209637 and rs4327369 within ATP2B2, rs12026, rs7785846 and rs12704796 within PON2) and NIHL in 454 subjects. All the SNPs were genotypes, using the TaqMan MGB probe assay. Odds ratios (ORs) were calculated with 95% confidence intervals (95% CIs) with logistic regression analysis to test the level of association for SNPs. RESULTS In our study, 221 subjects with hearing loss and 233 subjects without hearing loss were recruited. The frequencies of the CG and CG + GG genotype of rs12026 (PON2) conferred risk factors for NIHL with adjusted OR values of 2.62 (95% CI, 1.69-4.06) and 2.48 (95% CI, 1.63-3.78), respectively. This kind of significance was also found at locus rs7785846, where genotypes CT and CT + TT were the risk types, with adjusted ORs of 2.52 (95% CI, 1.62-3.93) and 2.35 (95% CI, 1.54-3.58), respectively. We performed stratified analysis per noise exposure level, when it came to rs7785846 and rs12026 in the >92 dB(A) noise exposure group, the subjects who carried heterozygote were of significantly (P<0.01) higher susceptibility to NIHL than homozygote carriers. By contrast, no significantly higher risk was found for any rs12704796 genotypes or any genotypes in ATP2B2 (P>0.05), which may suggest that these SNPs did not have significant effects on noise susceptibility across noise exposure. CONCLUSIONS Our research suggested that PON2 might play a role in the etiology of NIHL in Chinese of Han nationality population.

Association between endocrine function and radiation exposure

Background: To observe the relationship of change in endocrine function within radiation exposure and try to evaluate the correlated factors about thyroid function and glucose metabolism. Methods: A total of 1,784 subjects from physical examination organization for occupational health from year 2015 to 2016 were investigated. Results: The abnormal proportion of T3 and T4 of female were higher than male. Glucose level showed a significant increase in overweight (5.35±1.01) and decrease in underweight group (4.77±0.47) compared with normal group (5.05±0.85). Subjects whose exposure time longer than 3 years were likely to get higher T4 level than those less than 3 years (P Conclusions: Changes in thyroid function and glucose metabolism may appear after long time exposure to radiation.

Association between plasma membrane Ca 2+ -ATPase gene polymorphisms and noise-induced hearing loss in a Chinese population

Background: Noise-induced hearing loss (NIHL) has become a world-wide high occupational health risk. The current research is aimed at investigating the association of plasma membrane Ca 2+ -ATPase isoform 2 ( PMCA2 ) gene polymorphisms with the susceptibility to NIHL in a Chinese population. Methods: A total of 2,344 workers exposed to occupational noise were examined with hearing tests. According to the results of audiometry, we selected 613 cases with high frequency hearing threshold worse than 25 dB and 615 controls with high frequency hearing threshold better than or equal to 25 dB and the controls were frequency matched with cases in terms of age, gender and noise exposure level and exposure time. The individual genotypes for PMCA2 single nucleotide polymorphisms (SNPs) were determined using a TaqMan MGB probe assay performed on an ABI PRISM ® 7900 HT Fast Real-Time PCR System (Applied Biosystems). Information about these subjects was collected by questionnaires which were conducted through face-to-face interviews by trained interviewers. Results: We found that individuals with the rs3209637 CC genotype had a statistically significantly increased risk of NIHL compared with those who carried the rs3209637 TT genotype (adjusted OR =1.26, 95% CI =1.07–1.48) and this increased risk was more pronounced among the workers in the 15- to 25-year noise exposure time, >92 dB(A) noise exposure level. Similar effects were also observed in a recessive model. Conclusions: Our data suggested that the PMCA2 polymorphisms may be a genetic susceptibility marker for NIHL in the Chinese Han population.

Correlation between CAT polymorphism and susceptibility to DMAc-Induced Abnormal Liver Function: A case-control study of Chinese Population

Abstract Context: Acute or chronic exposure of N,N-dimethylacetamide (DMAc) is responsible for abnormal liver function. It appears that DMAc is mainly metabolized by cytochrome P450 in the liver and thereby produces reactive oxygen species (ROS). The elimination of ROS and the repairing of ROS-induced DNA damage are relevant to the ultimate toxicity of DMAc. Objective: To investigate whether the polymorphisms in the CAT (rs564250, rs769214 and rs7943316), hOGG1 (rs2072668 and rs159153) and XRCC1 (rs25487 and rs1799782) genes are associated with susceptibility to DMAc-induced abnormal liver function in Chinese population. Methods: Samples were obtained from 108 workers with DMAc-induced abnormal liver function and 108 workers with normal liver function. Results: Subjects with the CAT rs769214 GA/GG genotypes had a reducing risk of abnormal liver function, which was more evident in the subgroups exposed to DMAc <10 years, exposed to DMAc <5 mg/m3, never smoked and never drank. Conclusions: CAT rs769214 (-844 G > A) polymorphism may be associated with DMAc-induced abnormal liver function in Chinese population.