ABSTRACT
This study investigated the correlation between surfactant protein-A (SP-A) polymorphism and the susceptibility of chronic obstructive pulmonary disease (COPD) in Xinjiang Uighurs.Genomic DNA was extracted from peripheral blood of 194 COPD smokers and 201 healthy smokers of Uighur who were hospitalized in or paid a visit to one of the four Xinjiang-based hospitals involved in the study,from March 2009 to December 2010.Single nucleotide polymorphisms (SNPs) were studied at aa62 (CCA/CCG rs 1136451) and aa219 (CGG/rGG,rs4253527) in SP-A.Genotypes were determined by using the TaqMan polymerase chain reaction (PCR).Our results showed that genotype frequencies were different between the COPD and normal smokers in aa62 (x2=6.852,P=0.033).There were also significant differences in allele genotype frequencies between the COPD and the control and allele G might decrease the risk COPD (x2=6.545,P=0.011; OR=0.663; 95％ CI:0.484-0.909).The result suggested that polymorphism of aa62 (CCA/CCG,rs1136451) of SP-A may be associated with the susceptibility to COPD in Xinjiang Uighurs.
ABSTRACT
The DNA damage, caused by cigarette smoking, can cause airway cell apoptosis and death,which may be associated with the development of chronic obstructive pulmonary disease (COPD).However, just 20%-30% smokers develop COPD, which suggests that different degrees of DNA repair cause different outcomes in smokers. X-ray repair cross-complementing group 1 (XRCC1), a base exci-sion repair protein, has multiple roles in repairing ROS-mediated, basal DNA damage and single-strand DNA breaks. The present study investigated the association between polymorphism in XRCC1 (Arg399Gln) and susceptibility of COPD. A total of 201 COPD cases and 309 controls were recruited and frequency-matched on age and sex. XRCC1 genotype was determined by PCR-restrietion fragment length polymorphism analysis. Overall, compared with those with the XRCC1 Arg/Arg genotype, the risk for COPD had no significant difference among individuals with Trp/Trp genotype. However, after stratifying by smoking status, in former smokers, compared with those with the XRCC1 Arg/Arg geno-type, the risk for COPD was significantly reduced among individuals with Trp/Trp genotype (adjusted OR=0.22, 95% CI 0.06-0.85, P=0.028); after stratifying by smoking exposure, in light smokers, com-pared with those with the XRCC1 Arg/Arg genotype, the risk for COPD was significantly reduced among individuals with Arg/Trp genotype and Trp/Trp genotype (adjusted OR=0.39, 95% CI 0.16-0.94,P=0.036; 0.24, 95% CI 0.07-0.79, P=0.019, respectively). In conclusion, XRCC1 Arg194Trp genotype is associated with a reduced risk of developing COPD among former and light smokers.