AbstractBackgroundChronic obstructive pulmonary disease (COPD) is one of the diseases with high mortality and morbidity with complex pathogenesis. Airway remodeling is an unavoidable pathological characteristic. However, the molecular mechanisms of airway remodeling are incompletely defined.MethodslncRNAs highly correlated with transforming growth factor beta 1(TGF–β1) expression were chosen, the lncRNA ENST00000440406 (named HSP90AB1 Assoicated LncRNA 1, HSALR1) was chosen for further functional experiments. Dual luciferase and ChIP assay were used to detect the upstream of HSALR1, transcriptome sequencing, Cck–8, Edu, cell proliferation, cell cycle assay, and WB detection of pathway levels confirmed the effect of HSALR1 on fibroblast proliferation and phosphorylation levels of related pathways. Mice was infected with adeno–associated virus (AAV) to express HSALR1 by intratracheal instillation under anesthesia and was exposure to cigarette smoke, then mouse lung function was performed and the pathological sections of lung tissues were analyzed.ResultsHerein, lncRNA HSALR1 was identified as highly correlated with the TGF–β1 and mainly expressed in human lung fibroblasts. HSALR1 was induced by Smad3 and promoted fibroblasts proliferation. Mechanistically, it could directly bind to HSP90AB1 protein, and acted as a scaffold to stabilize the binding between Akt and HSP90AB1 to promote Akt phosphorylation. In vivo, mice expressed HSALR1 by AAV was exposure to cigarette smoke (CS) for COPD modeling. We found that lung function was worse and airway remodeling was more pronounced in HSLAR1 mice compare to wild type (WT) mice.ConclusionOur results suggest that lncRNA HSALR1 binds to HSP90AB1 and Akt complex component, and enhances activity of the TGF–β1 smad3–independent pathway. This finding described here suggest that lncRNA can participate in COPD development, and HSLAR1 is a promising molecular target of COPD therapy.

Background Airway smooth muscle (ASM) remodeling is a hallmark in chronic obstructive pulmonary disease (COPD). NADPH oxidase 4- (NOX4-) mediated reactive oxygen species (ROS) production plays a crucial role in cell differentiation and extracellular matrix (ECM) synthesis in ASM remodeling. However, the precise mechanisms underpinning its pathogenic roles remain elusive. Methods The expression of NOX4 and TGF-β1 in the airway of the lung was measured in COPD patients and the control group. Cigarette smoke- (CS-) induced emphysema mice were generated, and the alteration of α-SMA, NOX4, TGF-β1, and collagen I was accessed. The changes of the expression of ECM markers, NOX4, components of TGF-β/Smad, and MAPK/Akt signaling in human bronchial smooth muscle cells (HBSMCs) were ascertained for delineating mechanisms of NOX4-mediated ROS production on cell differentiation and remodeling in human ASM cells. Results An increased abundance of NOX4 and TGF-β1 proteins in the epithelial cells and ASM of lung was observed in COPD patients compared with the control group. Additionally, an increased abundance expression of NOX4 and α-SMA was observed in the lungs of the CS-induced emphysema mouse model. TGF-β1 displayed abilities to increase the oxidative burden and collagen I production, along with enhanced phosphorylation of ERK, p38MAPK, and p-Akt473 in HBSMCs. These effects of TGF-β1 could be inhibited by the ROS scavenger N-acetylcysteine (NAC), siRNA-mediated knockdown of Smad3 and NOX4, and pharmacological inhibitors SB203580 (p38MAPK inhibitor) and LY294002 (Akt inhibitor). Conclusions NOX4-mediated ROS production alters TGF-β1-induced cell differentiation and collagen I protein synthesis in HBSMCs in part through the p38MAPK/Akt signaling pathway in a Smad-dependent manner.

目的 通过粪菌移植(FMT)方法在小鼠上建立慢性阻塞性肺疾病(简称慢阻肺)的肠道菌群研究模型并对其移植效果进行初步评价.方法 入组健康对照、慢阻肺Ⅰ-Ⅱ级和慢阻肺Ⅲ-Ⅳ级患者各30例并收集其粪便制作粪菌混悬液,通过灌胃方法对小鼠进行FMT.移植后第29天采集全血行单个核细胞分析,对小鼠移植前后的肠道菌群进行16S rRNA测序分析,对模型小鼠进行初步疾病模型评价.结果 抗生素预处理后小鼠肠道的OTU、Chao 1和Shannon指数均显著下降(P＜0.001),接受健康对照和慢阻肺患者FMT后的受体小鼠其OTU、Chao 1和Shannon指数显著升高(P＜0.01或P＜0.05).健康对照FMT组、慢阻肺Ⅰ-Ⅱ FMT组和慢阻肺Ⅲ-Ⅳ FMT组小鼠菌群丰度在厚壁菌门、变形杆菌门和放线门中均与磷酸盐缓冲液FMT组小鼠存在显著性差异(P＜0.05或P＜0.01).慢阻肺Ⅰ-Ⅱ FMT组和慢阻肺Ⅲ-Ⅳ FMT组小鼠外周血CD3+、CD3+CD4+和CD3+CD8+细胞百分比升高(P＜0.05或P＜0.01),而CD3-CD19+细胞百分比下降(P＜0.05).结论 通过FMT可在小鼠上成功建立慢阻肺肠道菌群研究模型.

Understanding the pathogenesis of SARS-CoV-2 is crucial to respond to the current coronavirus disease 2019 (COVID-19) pandemic. Sputum samples from 20 COVID-19 patients and healthy controls were collected, respectively. During the isolation of infectious SARS-CoV-2 virus, EV-like vesicles were associated with virions under a transmission electron microscope. Next, the expression of IL6 and TGF-β increased in EVs derived from the sputum of patients, and these were highly correlated with the expression of the SARS-CoV-2 N protein. Further, proximity barcoding assay (PBA) was used to investigate the immune-related proteins in the EVs, and the relationship between EVs and SARS-CoV-2 N protein in COVID-19 patients’ samples. Particularly, to investigate the differential contribution of the specific EV subsets, the protein expression of a single EV was detected and analyzed for the first time. Among the 40 EV subpopulations, 18 were found to have significant differences. The EV subpopulation regulated by CD81 were most likely to correlate with the changes in the pulmonary microenvironment after SARS-CoV-2 infection. This study provides evidence on the association between EVs and the SARS-CoV-2 virus, give a deep insight into the possible pathogenesis of SARS-CoV-2 infection and the possibility of nanoparticles drug intervention in viral infection.

1National Center for Respiratory Medicine, State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510120, People’s Republic of China; 2Department of Geriatrics, National Clinical Key Specialty, Guangzhou First People’s Hospital, South China University of Technology, Guangzhou, 510180, People’s Republic of China; 3The Pulmonary Medicine, Guangzhou First People’s Hospital, School of Medicine, South China University of Technology, Guangzhou, 510180, People’s Republic of China; 4GMU-GIBH Joint School of Life Sciences, Guangzhou Medical University, Guangzhou, 511436, People’s Republic of China

Objective: Chronic hypoxia (CH) causes remodeling not only in pulmonary arteries but also in pulmonary veins. Pulmonary vascular remodeling stems from increased pulmonary vascular myocytes proliferation. However, the pathogenesis of CH-induced proliferation of pulmonary venous smooth muscle cells (PVSMC) remains currently unknown. The present study aimed to explore the mechanisms by which CH affects PVSMC proliferation. Methods: PVSMC were isolated from rat distal pulmonary veins and exposed to CH (4% O2 for 60h). The expression of calcium sensing receptor (CaSR) in PVSMC was determined by immunofluorescence, real-time Quantitative PCR and Western blotting. Cell proliferation was assessed by cell counting, CCK-8 assay, and BrdU incorporation. Results: CaSR was expressed in rat PVSMC. In PVSMC, CH increased the cell number and cell viability and enhanced DNA synthesis, which is accompanied by upregulated mRNA and protein expression level of CaSR. NPS2143 or NPS2390 not only weakened CH-induced upregulation of CaSR expression but also inhibited CH-induced increase in cell number, cell viability and proliferation index of PVSMC, whereas spermine or R568 not only amplified CH-induced CaSR upregulation but also enhanced CH-induced increase in cell number, cell viability and proliferation index of PVSMC. Furthermore, knockdown of CaSR in hypoxic PVSMC with siRNA attenuated CH-induced enhancement of cell number, cell viability and DNA synthesis in PVSMC. Conclusions: CaSR mediating excessive PVSMC proliferation is a new pathogenic mechanism involved in the initiation and progression of hypoxic PVSMC proliferation.

大气颗粒物(particulate matter,PM)是指空气中悬浮的混合污染物,包括烟雾、灰尘、固体或液体的复杂混合物,以及多种生物成分,主要来源于自然现象(如沙尘暴)、工业生产、生物燃料使用和交通相关活动.大气PM的暴露与多种疾病的患病率和死亡率有着明显的相关性[1-2].流行病学研究表明,大气PM暴露显著增加呼吸系统疾病的患病风险[3-5],我们发现这在慢性阻塞性肺疾病(简称慢阻肺)上表现得尤为明显[6-7],而减少PM暴露的浓度能够改善慢阻肺患者的肺功能和减少急性发作[8].

In order to ensure the habitability of nuclear power plant emergency management center in the accidents with massive radioactive material release,the emergency ventilation filter system is always designed and installed.The iodine filter is an important radio-iodine removal device in the ventilation system.The principle of the iodine filter determines that the adsorption efficiency is varied with the temperature and relative humidity of working environment,iodine concentration of air intake and other factors.Using the design feature of an emergency management center built in a nuclear power plant,corresponding to RG1.183 DBALOCA and S3 accident source term,the relationship between the adsorption efficiency of iodine filter and the effective dose,thyroid equivalent dose of the staff working in the emergency management center is studied,and the coefficients of linear fitting are given,which can be used for quick estimation of nuclear accident consequence.

Objective To study the effects of nicotine on cell proliferation,invasion and migration of A549 and explore the possible mechanisms.Methods The abilities of proliferation,migration and invasion of A549 cell were measured by CCK-8,Transwell test,and wound scratch assay respectively.The expressions ofα7 nicotinic acetylcholine receptor (nAChR),vascular endothelial growth factor (VEGF) and matrix metalloproteinase-2 (MMP-2) were observed by Western blot.Results Compared with the control group,10-6 mol/L nicotine promoted A549 proliferation,migration and invasion significantly (all P <0.05).Nicotine increased the protein expressions ofα7 nAChR,VEGF and MMP-2.Conclusions Nicotine can increase proliferation,migration and invasion of human lung adenocarcinoma A549 cell throughα7 nAChR,which may be associated with the upregulation of VEGF and MMP-2 protein expressions.

目的:构建稳定表达LBH基因的人前列腺癌细胞株PC-3M-LBH,探讨LBH基因对PC-3M细胞增殖能力的影响.方法:构建表达LBH基因的重组慢病毒载体并制备出相应的慢病毒,感染低表达LBH基因的人前列腺癌PC-3M细胞后,经嘌呤霉素筛选获得细胞克隆;实时荧光定量PCR和蛋白印迹法(Western-Blot)分别检测细胞株中LBH的mRNA、蛋白表达水平;采用CCK-8法检测表达LBH基因后细胞增殖能力的改变.结果:成功构建了重组慢病毒表达质粒pLenti-LBH并包装出了慢病毒,感染前列腺癌细胞后经嘌呤霉素筛选得到PC-3M-LBH细胞株;PC-3M-LBH细胞株中LBH基因的mRNA和蛋白表达显著上调;相对母细胞和NC对照组,PC-3M-LBH细胞在接种后第4天即出现明显的生长抑制,到第6天其生长抑制率达到19.7％.结论:构建的细胞株能稳定表达LBH基因,该基因的表达能显著抑制前列腺癌PC-3M细胞的体外增殖.

Objective To determine the function and transcriptional regulatory elements of the regulatory region of-810~-769 bp upstream from the transcription initiation site of the human glutamate-cysteine ligase catalytic subunit (GCLC) gene. Methods The human GCLC gene regulatory region fragments were cloned and the wild-type plasmids were constructed. The mutant expression plasmids of deletion mutant-770~-766 GATAAG nucleotides and the site-directed mutant-765 and-764 GC to TA,-755 and-754 GG to TA were constructed. The transcriptional regulatory was determined by plasmid transfection. EMSA+super-shift method was used to identify transcriptional regulatory elements of-810~-769 bp upstream from the transcription initiation site of GCLC gene. Results The-810~-769 bp upstream of the transcription initiation site of human GCLC gene is the positive regulatory region,including NF-κB and AP-2 transcriptional elements. The transcription factor AP-2 could inhibit the binding of transcription factor NF-κB to the upstream-790~-766 DNA sequence of human GCLC gene transcription initiation site. Conclusion The regulatory region of-810~-769 bp upstream from the transcription initiation site of the human GCLC gene is a newly discovered positive regulatory region,which contains NF-κB and AP-2 regulatory elements.

Objective: To observe if arterial traffic ambient PM2.5 (TAPM2.5) and wood smoke PM2.5(WSPM2.5) exposure can induce epithelial-mesenchymal transition (EMT) in human bronchial cells (HBEC). Methods: PM2.5 was collected from an arterial traffic road and a typical southern kitchen, and then the collections were extracted by DMSO. The viability of HBEC was measured by Cell Counting Kit (CCK-8) after culture with PM2.5-DMSO extracts for 24 hours. The expressions of EMT markers, including E-cadherin, cytokeratin, α-smooth muscle actin (α-SMA), vimentin and collagen typeⅠ (COL-Ⅰ) in HBEC were assayed by cell immunofluorescence and Western blot analysis after exposed to two different sources of PM2.5-DMSO extracts for 14 days. Results: The cell viability of HBEC increased at low concentrations (1, 2, 10 μg/ml and 1, 5, 10 μg/ml, corresponding to [(118.4±13.7)%, (118.2±8.0)%, (123.0±19.6)% and (112.4±4.1)%, (120±5.4)%, (117.8±7.0)%, respectively, all P<0.05], and then declined at high levels [20, 100, 200 μg/ml and 15, 20, 30, 40 μg/ml, corresponding to (100.7±12.1)%, (53.4±15.3)%, (9.4±1.7)% and (106.8±10.0)%, (93.8±7.9)%, (60.9±9.5)%, (46.2±3.6)%, respectively, P values were 0.923, 0.000, 0.000 and 0.231, 0.278, 0.000, 0.000, respectively] in both TAPM2.5-DMSO and WSPM2.5-DMSO incubation. After exposure for 14 days, the cells lost their typical cobblestone-like shape which implied that EMT might occur. The same treatment caused decreased positive signals of E-cadherin and cytokeratin in a small proportion of the cells. The decreased expressions of cytokeratin were verified by Western blot (TAPM2.5 and WSPM2.5 were 0.063±0.109 and 0.039±0.313, P values were 0.033 and 0.030, respectively), while α-SMA was only significantly upregulated in the WSPM2.5-DMSO group (7.853±4.784, P=0.049). The expressions of E-cadherin decreased in both groups but not statistically significant in Western blot (0.862±0.096 and 0.817±0.212, P values were 0.228 and 0.117, respectively). Another marker of EMT, COL-I, markedly increased in both PM2.5 treatment groups (2.549±1.037 and 3.658±1.207, P values were 0.034 and 0.001). Conclusions: Both PM2.5 from arterial traffic ambient air and wood smoke could induce EMT in human bronchial epithelial cells, while WSPM2.5 appeared to have a more significant influence on EMT in HBEC.

Objective To explore the relationship between the decreased expression of AMP-18 mRNA and different degree of gastric cancer in rats. Methods A total of 20 healthy SD ratswere divided into 4 groups:groups A, B, C and D. A rat model of stomach cancer was established by feeding water with N-Methyl-N′-Nitro-Nitrosoguanidine (MNNG), Tween 20 and vitamin D3. The rats in the four groups were killed respectively at weeks 14, 18, 22 and 24. Then gastric antrum mucosa tissues were detected by using HE staining to observe the pathological changes and by real-time quantitative PCR (Q-PCR) technique to detect the expression of AMP-18 mRNA in rats. Results HE staining section showed that group C developed early gastric cancer, and group D developed progressive gastric cancer. The expression of AMP-18 mRNA in groups C and D wassignificantly lower than that in group A by Q-PCR. Conclusion AMP-18 mRNA expression decreased obviously in early orprogressive gastric cancer.

Objective To investigate the effects of adenovirus 5 latent infection on the oxidantantioxidant imbalance caused by exposure to biomass fumes in guinea pigs.Methods Forty-six albino guinea pigs were randomly divided into two groups.One group (n =26) was infected intranasally with adenovirus 5,and the other group (n =20) was shame-infected with sterile PBS as control.After 22 days,the living animals (20 each group) were randomly divided into two subgroups.One subgroup was exposed to biomass fumes for three weeks,and the other subgroup was exposed to room air.At the end of the experiment,animals were sacrificed and lung tissues were examined with histopathology.The persistence of the adenovirus latent infection was confirmed at the end of the study by immunohistochemistry to demonstrate the adenovirus E1A protein in the lungs of infected animals.The activities of glutathione peroxidase (GSH-PX),superoxide dismutase (SOD),and catalase (CAT),the levels of glutathione (GSH) and malondialdehyde (MDA),total ability of antioxidant in lung tissue homogenate and serum were measured.The activity of SOD,MDA and total ability of antioxidant in the bronchoalveolar lavage fluid were measured.Results The latent infection of adenovirus was associated with significant decrease of GSH-PX,GSH,SOD,total ability of antioxidant in the lung tissue homogenate and serum.However,it caused decrease of CAT and increase of MDA in lung tissue homogenate.At the same time,the biomass fumes was associated with obvious decrease of GSH-PX,GSH,SOD,CAT,total ability of antioxidant in the lung tissue homogenate and serum.It was demonstrated that the biomass fumes and the latent infection of adenovirus were associated with significant decrease of GSH-PX in lung tissue homogenate and GSH-PX,GSH in serum.Conclusions Biomass fumes can lead to the oxidant-antioxidant imbalance in the lung tissue of guinea pigs,and the imbalance is amplified by the latent infection of adenovirus 5.

Objective To established a new method of using living cell workstation and fluorescent probe for dynamic monitoring of intracellular reactive oxygen species(ROS)and cell apoptosis. Methods The cells were incubated in the working concentrations of 5 μmol/L ROS living cell fluorescent probes C10422 and C10444,and 10 mg/L mitochondrial membrane function probe JC?1 for 30 min,and in apoptosis indication probe AnnexinV/PI for 15 min. Then, the living cell workstation was used to continuously record the fluorescent grey value of specific wavelength during the 1 mmol/L H2O2 stimulation, and to evaluate the ROS level,mitochondrial membrane potential and apoptosis indexes. Results For the 16HBE and A549 cells,under the continuous stimulation of 1 mmol/L H2O2,the ROS living cell fluorescent probes C10422 and C10444 showed continuously increasing fluorescent grey value of specific wavelength, and the significantly increased ROS levels were reached at 80 min and 10 min,respectively(all P<0.05);the mitochondrial membrane function probe JC?1 showed the transition of the fluorescent grey value between the two specific wavelengths,and the significantly decreased R/G ratio,which was the index of cell mitochondrial function,was reached at 20 min(P<0.05);the apoptosis probe AnnexinV showed increased aggregation of fluorescence in the region of the cell membrane,but the fluorescent grey value of the general view was not significantly changed. For A549 cells,under the same experiment condition of 1mmol/L H2O2&nbsp;stimulation,the ROS level increased but was lower than that of 16HBE cells(P<0.05);the R/G ratio curve as detected with the mitochondrial membrane function probe JC?1 showed a continuous declining trough and then partially rebounced. Conclusion Living cell fluorescent probing based on living cell workstation can be more objective in reflecting the cell oxidative stress and apoptosis.

To evaluate the cost-effectiveness of a new covered stent (WILLIS) vs. endovascular coil occlusion for the treatment of intracranial aneurysms in china. A decision tree model was constructed and the treatment impact was projected up to 6 months. 88 endovascular coil occlusion treated initial intracranial aneurysms patients and 34 recurrence intracranial aneurysms patient (with aneurysm diameter > 7 mm) charts were reviewed and direct medical cost data were collected from hospital information system in multi-hospitals in 12 cities in China. Direct medical cost data, including drug cost, medical device cost, daily bed expenses, nursing fee, and examination cost were abstracted from the charts. The aneurysm recurrence rates by WILLIS and Coil treatments were obtained through literature review. The mortality rate of intracranial aneurysms recurrence, and side effects rates of treatments were collected through a direct expert survey. The main summary measure in this evaluation was incremental cost per death avoided. One way sensitivity analysis was performed to determine the robustness of the results. The total direct medical cost was 141,582.95 RMB and 177,407.35 RMB for Willis and coil occlusion treatments respectively; the recurrence rate of intracranial aneurysms was 0% and28.9% for Willis and coil occlusion treatments in Chinese patients respectively; Relapse mortality of intracranial aneurysms is 0.2% in Chinese patients. The result suggests a dominant effect of Willis treatment over coil occlusion with an incremental cost-effectiveness ratio (ICER) of -63055263.7RMB/avoided death. This indicates that Willis treatment has demonstrated better efficacy and lower overall costs. The one-way sensitivity analysis didn’t change the conclusion, indicating the robustness of the results. Compared with endovascular coil occlusion, a new covered stent (WILLIS) improves clinical outcomes and reduces overall medical costs for the treatment of Chinese intracranial aneurysms patients (Diameter > 7 MM).

目的：探讨AKT信号途径在尼古丁诱导大鼠气道平滑肌细胞增殖中发挥的作用。方法（1） Western blot检测不同浓度尼古丁作用原代培养的大鼠气道平滑肌细胞不同时间段，AKT／磷酸化AKT、GSK3β／磷酸化GSK3β在气道平滑肌细胞上的表达水平；（2）细胞分析计数仪检测AKT抑制剂和GSK3β抑制剂对尼古丁促进大鼠气道平滑肌细胞增殖活性的影响。实验分组：对照组、尼古丁单独作用组、AKT抑制剂LY294002组、AKT抑制剂LY294002＋尼古丁组、GSK3β抑制剂SB216763组、GSK3β抑制剂SB216763＋尼古丁组；（3） EDU摻入法测定AKT抑制剂和GSK3β抑制剂对尼古丁处理大鼠气道平滑肌细胞DNA复制活性的影响，实验分组同上。对照组应用1％胎牛血清培养基，各抑制剂和尼古丁应用1％胎牛血清培养基配制，分别在尼古丁加入前30 min应用。结果（1）大鼠气道平滑肌细胞上有AKT和GSK3β的表达；尼古丁引起AKT和GSK3β的快速磷酸化，且尼古丁促进AKT和GSK3β的磷酸化作用具有时间依赖性；（2）细胞计数法显示，AKT抑制剂与尼古丁联合组细胞计数明显低于尼古丁单独作用组，差异有统计学意义（P＜0．05）；（3）EDU摻入法测定显示，AKT抑制剂与尼古丁联合组细胞DNA复制水平明显下降，与尼古丁单独作用组相比，差异有统计学意义（ P＜0．05）。结论尼古丁促进大鼠气道平滑肌细胞的增殖作用依赖AKT／GSK3β信号途径。

Objective To investigate the association between susceptibility to chronic obstructive pulmonary disease (COPD) and the polymorphisms and methylation of glutamate-cysteine ligase catalytic subunit (GCLC) gene.Methods One hundred and sixty-six patients with COPD (COPD group) and 166subjects without COPD (control group) were recruited in this study.The single nucleotide polymorphisms (SNPs) of GCLC promoter region of two groups were investigated by DNA sequencing,which entailed the analysis on the association between haplotypes of individual SNP locus of GCLC gene and the risk of developing COPD.The level of GCLC promoter methylation was determined by using methylated DNA immunoprecipitation chip (MeDIPchip).The GCLC mRNA expressions and the levels of serum glutathione (GSH) were examined and compared between two groups.Results Twelve SNPs in GCLC gene promoter region were identified by direct DNA sequencing.Only 4 SNPs (-2137MT,-129C/T,+27591C/G,+37764MG) were found to harbor 10％ incidence in both groups.The-129C/T was in linkage disequilibrium with-2137A/T,+27591C/G and + 37764A/G.However,no difference in GCLC SNP allele frequency or genotype frequency was observed between COPD patients and controls (all P＞0.05).Compared with the control group,the methylation level of GCLC promoter was significantly increased in COPD patients (P＜0.001),as evidenced by the MeDIP-chip assay,and the expression of GCLC mRNA was down-regulated in the lung tissues (3.71±0.48 vs 5.16±0.39,P＜0.05) and serum GSH levels decreased [(109.72±32.38) mg/L vs (179.87±46.23) mg/L,P＜0.05] in COPD patients.Conclusion Methylation,but not polymorphisms of GCLC promoter is associated with the susceptibility to COPD in Chinese population.