ABSTRACT
@#Abstract: objective 2+- Toinvestigatethecorrelationbetween geneticpolymorphismofplasmamembraneCa ATPaseisoform2 PMCA2 - Methods ( )andsusceptibilitytonoise inducedhearingloss(NIHL). Atotalof228workerswithNIHLwereselectedas the case group by simple random sampling method,and 230 normal hearing workers with similar age,length and level of noise exposure were selected as the control group.DNA was extracted from peripheral blood of workers of the two groups,and single PMCA2 Results nucleotidepolymorphism (SNP)of wasgenotypedbyMassArraysystem. Theallelefrequenciesofrs1719571 PMCA2 - P and rs14154 of gene in the control population were consistent with Hardy Weinberg equilibrium (both >0.05). There was no significant difference in the distribution of rs1719571 and rs14154 genotypes and allele frequencies between the two P groups(all >0.05).LogisticregressionanalysisshowedthattheriskofNIHLinGAgenotypeofrs1719571waslowerthanthat-P in GG genotype (odds ratio=0.53, 95% confidence interval=0.31 0.90, <0.05), after excluding the effects of age, length of exposure to noise, intensity of exposure to noise, smoking and alcohol consumption. The genotype of SNP rs14154 might not P Conclusion PMCA2 contribute to the genetic susceptibility of NIHL( >0.05). The SNP of rs1719571 is associated with the susceptibilityofNIHL,andGAgenotypemaybeapotentialprotectivefactorforNIHL.
ABSTRACT
Objective To study the expression of plasma membrane Ca2+-ATPase isoforms 1~3 (PMCA 1~3 )in the basilar membrane (BM)of the neonatal rat cochlea by Western blot.The PMCA2 content in single BM of the neonatal rat was also examined.Methods Four rats at postnatal 2 days (P2)and 8 days (P8)were respective-ly decapitated and their BMs were isolated.The total proteins of BMs were extracted.The 20μg total proteins were respectively loaded to the gel.The expression of PMCA1-3 was detected by Western blot.Likewise,3μg total proteins from P2 and P8 rat BM were loaded.The expression of PMCA2 was detected by Western blot.Four rats at P8 were decapitated and their BM was isolated.The 5μg,10μg and 20μg total proteins of P8 rat BM were added to the gel and 100 ng,400 ng and 800 ng bovine serum albumin (BSA)were also loaded as reference.After electro-phoresis,the gel was separated into two parts.One part was used for SYPRO staining and the other part was used for PMCA2 detection by Western blot.Results In the 20μg BM total proteins of P2 and P8 rats,the expression of PMCA1 was weak (0.126±0.024,0.131±0.012,respectively),PMCA2 was strong (4.16±0.528,4.25±0.319, respectively),and PMCA3 was barely expressed (0 ).There was a statistical difference among PMCA1 ,PMCA2 and PMCA3(P<0.05).In the 3μg BM total proteins of P2 and P8 rats,the expression of PMCA2 in P8 (4.571± 0.336)was higher than P2 (3.622±0.285).There was a statistical difference(P<0.05).The PMCA2 content in the BM of a P8 rat was about 2 .5 ng.Conclusion There was a different-level expression of PMCA1~3 in the neonatal rat BM with highest expression of PMCA2 ,which could be explained that cochlear hair cells had different requirements of Ca2+ turning for these PMCA isoforms.
ABSTRACT
Objective To investigate the association between polymorphisms of Ca2 + -ATPase isomer 2 gene (PMCA2) in plasma membrane and the development of sudden deafness .Methods Totally ,164 patients were investigated and hearing tests were conducted .According to the results of audiometry ,they were divided into two groups ,sensorineural hearing loss group(n= 82) and normal hearing group(n= 82) .Polymorphisms of two single nucleotide loci rs2289274 and rs6790640 in the PMCA2 gene were de-termined by polymerase chain reaction followed by allele specific amplication analysis .Results In the sudden deafness group ,fre-quencies of genotypes AA ,AG and GG in the rs2289274 locus were 55 .8% ,17 .4% and 26 .8% respectively ,while frequencies of al-leles A and G in the same locus were 64 .5% and 35 .5% respectively ;in the sensorineural hearing loss group ,were 26 .8% ,28 .0%and 45 .2% respectively ,while frequencies of alleles A and G were 41 .1% and 58 .9% .And ,in the sudden deafness group ,frequen-cies of genotypes CC ,CT and TT in the rs2289274 locus were18 .3% ,35 .4% and 46 .3% respectively ,while frequencies of alleles C and T in the same locus were 36 .3% and 63 .7% ;in the normal hearing group ,were 2 .4% ,63 .4% and 34 .1% respectively ,while frequencies of alleles C and T were34 .1% and 65 .9% ,respectively .Genotypes distribution of two sites and their allele frequencies of the two groups ,some differences of them had statistical significance(P< 0 .05) .Conclusion It is suggested that genetic polymor-phism of the rs2289274 and rs6790640 loci in the PMCA2 gene might be a susceptible factor for sudden deafness .