Association of ADAM33 gene polymorphisms with COPD in the Mongolian population of China

Signatures for chronic obstructive pulmonary disease (COPD) and asthma: a comparative genetic analysis

Background: Chronic obstructive pulmonary disease (COPD) and asthma are obstructive lung diseases which progress in severity with time. Environmental causes and genetic makeup of individuals play important roles in disease manifestation. The aim of present study was to search for diagnostic/prognostic biomarkers to differentiate COPD and asthma.Materials and methods: Seven ADAM33 and two AQP5 single-nucleotide polymorphisms (SNPs) were genotyped by polymerase chain reaction-restriction fragment length polymorphism method. The association of genotypes, haplotypes and allelic combination of variants in different genes was analyzed in 194 COPD, 150 asthma patients and 220 controls.Results: The genotype frequencies of SNPs V4(C/G), T1(T/C), S2(G/C) of ADAM33 and AQP5 A/G (rs3736309) were associated with COPD and asthma (P=0.038 to P<0.001), while S1(A/G) and F+1(C/T) were associated with asthma (both P<0.001) and V1(G/T) with 20 COPD (P<0.001). The allele frequencies of V4(C/G) (both P<0.001), V1(G/T) (both P<0.05), S2(G/C) (both P<0.01) and S1(A/G) (both P<0.05) were associated with COPD and asthma, while F+1(C/T) was associated only with asthma (P=0.005). Haplotypes of ADAM33 'GGTGGGT' (P=0.027), 'CGTCGGC' (P<0.001) and AQP5 'GA' and 'AG' (both P<0.001) were significant only in COPD.Conclusion: ADAM33 F+1(C/T) variant and allele combination 'GGTGGGTGA' may be specific markers for asthma, while AQP5 'AG' appeared as a haplotype associated only with COPD. These specific genetic biomarkers may be exploited to predict individual predisposition to COPD and asthma.

Association between F+1 polymorphism in a disintegrin and metalloprotease 33 (ADAM33) gene and chronic obstructive pulmonary disease susceptibility: An evidence-based meta-analysis

BACKGROUND

The F+1 (rs511898 G>A) polymorphism in a disintegrin and metalloprotease 33 (ADAM33) gene has been implicated in susceptibility of chronic obstruction pulmonary disease (COPD). However, a series of studies have reported inconclusive. The aim of this study is to explore the association between the F+1 (rs511898) of ADAM33 gene and COPD susceptibility by using the method of meta-analysis.

METHOD

PubMed, Embase, Cochrane Library, Chinese National Knowledge Infrastructure database (CNKI), Chongqing VIP database, Wanfang and China Biology Medicine (CBM) were searched comprehensively to obtain the related cohort studies and case-control studies. The included studies were selected according to inclusion criteria. The pooled odds ratios were performed respectively for allele comparison, additive model, dominant genetic model and recessive genetic model. The association between the F+1 polymorphism of ADAM33 gene and COPD susceptibility was measured by OR and 95%CI by STATA 12.0. The subgroup analysis was distinguished according to the ethnicity. The publication bias was tested by funnel plots and Egger's linear regression method.

RESULTS

Twelve case-control studies were included in the meta-analysis, which study is comprised of 6935 participants (2454 patients with COPD and 4481 controls). The meta results showed significant association between ADAM33 F+1 polymorphism and COPD susceptibility in allele model OR _total = 1.16(95% CI 1.04-1.30, P = 0.007), OR _Asian = 1.14(95% CI 1.02-1.27, P = 0.022), additive model OR _total = 1.27 (95% CI 1.13-1.43, P = 0.000), OR _Asian = 1.25 (95% CI 1.08-1.45, P = 0.003), recessive model OR _total = 1.49 (95% CI 1.16-1.91, P = 0.002), OR _Asian = 1.56(95% CI 1.09-2.22, P = 0.014), but not significant in Caucasians.

CONCLUSION

The ADAM33 F+1 mutant gene A may increase the risk of COPD among the Asian population, while it may not associate with the European population.

Genetic association of ADAM33 polymorphisms with childhood asthma in Chinese Han population: A case-control study

To explore the association of a disintegrin and metalloprotease 33 (ADAM33) polymorphisms with childhood asthma susceptibility, we conducted this case-control study.In this case-control study, we selected 96 asthma children and 86 healthy children to conduct the genotyping of ADAM33 polymorphisms through polymerase chain reaction-direct sequencing (PCR-DS). Hardy-Weinberg equilibrium (HWE) status in the control group was detected adopting chi-square test. Frequency differences of genotypes, alleles, and haplotypes were compared by chi-square test between the case and control groups. Linkage disequilibrium (LD) between polymorphisms was checked using Haploview software. Association intensity of the polymorphisms with the disease risk was assessed by odds ratio (OR) and 95% confidence interval (95%CI).The frequency of rs678881 GA genotype was obviously higher in cases than in controls (P = .03) and the carriage of this genotype conferred higher risk of asthma among children than GG genotype (OR = 2.03, 95%CI = 1.05-3.91). However, neither rs2280089 nor rs2853209 polymorphism was significantly associated with the risk of childhood asthma. Strong LD was found among rs678881, rs2280089 and rs2853209, and haplotype GGT was distinctly associated with the risk of asthma in children (OR = 0.28, 95%CI = 0.13-0.57).ADAM33 rs678881 polymorphism is significantly correlated with increased susceptibility to asthma in Chinese Han children. Besides, haplotype GGT among the 3 polymorphisms was obviously associated with decreased risk of childhood asthma.

Silencing of ADAM33 restrains proliferation and induces apoptosis of airway smooth muscle cells in ovalbumin-induced asthma model

A defibrinogen and metalloproteinase 33 (ADAM33) was reported to play an important role in asthma. Furthermore, ADAM33 may play a possible role in airway remodeling due to its high expression in myo-/fibroblasts, epithelium, as well as the airway smooth muscle cells (ASMCs). Thus, the study is supposed to investigate the effect of the downregulation of ADAM33 on the proliferation and apoptosis of ASMCs in allergic asthma. An ovalbumin-induced asthma model in rats was established for investigating the function of the silencing of ADAM33. ASMCs were cultured and divided into four groups after transfection. The messenger RNA and protein expressions of ADAM33 were measured by reverse transcription quantitative polymerase chain reaction and Western blot analysis. Cell proliferation was tested by cell counting kit-8 and cell apoptosis by TdT-mediated dUTP nick-end labeling. The allergic asthma rats showed a large number of inflammatory cell infiltration, airway smooth muscle hypertrophy and hyperplasia, and increased WA _t , WA _m , and numbers of bronchial smooth muscle nucleus. Additionally, increased numbers of eosinophils and neutrophils, expressions of immunoglobulin E and interleukin-4, content of airway air pressure, and NO, although decreased in expression of interferon-γ, were exhibited in rats with allergic asthma. In our study, upregulated ADAM33 was found, and after the silencing of ADAM33, decreased proliferation and increased apoptosis of ASMCs were observed. The study evidences that silencing of ADAM33 can decrease the proliferation and increase the apoptosis of ASMCs in a rat model of allergic asthma, suggesting ADAM33 represents a potential investigative focus target aiding allergic asthma.

ADAM33 gene polymorphisms identified to be associated with asthma in a Chinese Li population

A disintegrin and metalloprotease 33 (ADAM33) is an asthma susceptibility gene that has been proven to be present in certain human populations. The Li population is a minority ethnic group, most of whom maintain a distinctive lifestyle on Hainan Island in southern China. To the best of our knowledge, no previous study has established whether ADAM33 polymorphisms are associated with asthma in the Li population. Therefore, the ADAM33 polymorphisms in a Li population were investigated in the present study. A total of 150 asthma patients and 100 healthy subjects were enrolled in the present study, and their DNA samples were evaluated to analyze eight single-nucleotide polymorphisms (SNPs) on the ADAM33 gene. Asthma patients were subcategorized into low and high severity groups, and their SNP data were compared with the data of the control subjects. Single-marker and haplotype association was analyzed to demonstrate the association between ADAM33 SNPs and asthma using multiple genetic statistic tests. The results indicated significant differences in allele frequencies at the SNPs rs44707/T2 (P=0.008), rs2787094/V4 (P=0.028) and rs2280089/T+1 (P=0.021) between asthma patients and control subjects. The SNP rs44707/T2 was also found to be associated with the high severity group (P=0.024), although SNPs rs2787094/V4 were associated with the low severity group (P=0.019). Two haplotypes, GGAGAGT and GAAGGGT, were significantly associated with asthma (P=0.003 and 0.008, respectively). To the best of our knowledge, this is the first time that SNP rs2280089/T+1 has been reported to be associated with asthma in an Asian population. These data confirm that ADAM33 polymorphisms are associated with asthma susceptibility in the Li population and confirm the uniqueness of the Li minority population within China.

A disintegrin and metalloprotease 33 polymorphism association with COPD in long-term tobacco smokers of the ethnic Kashmiri population of India

Background:

Chronic obstructive pulmonary disease (COPD) is characterized by an interaction of various environmental influences especially cigarette smoking and genetic determinants. The prevalence of this disease is ever increasing and characterization of the genetic determinants of the disease has been undertaken globally. The ‘A disintegrin and metalloprotease 33’ (ADAM 33) gene is one candidate gene that has been studied.

Objective:

Our objective was to investigate whether single nucleotide polymorphisms in ADAM33 gene are associated with COPD in long-term tobacco smokers in the ethnic Kashmiri population of northern India.

Materials and Methods:

This was a randomized case-control study, which included 78 stable COPD (GOLD stage11-IV) patients, who were compared with 77 age- and sex-matched long-term tobacco smokers (>20 pack years) without any evidence of COPD. Polymorphic analysis for three single nucleotide polymorphisms (SNPs), (T1, T2, and Q1) of the ADAM33 gene was done by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) followed by sequencing. The data were analyzed by descriptive statistics and comparative evaluation was done by parametric/non-parametric tests.

Results:

The analysis of the T1, T2, and Q1 SNPs, revealed that the frequencies of the T2GG, T1GG, and the Q1AG genotypes were significantly higher in patients with COPD in comparison with the controls (P < 0.001). Similarly, the T1G and T2G allele frequency was higher in the patients than in the controls (p = 0.177 and 0.43, respectively).

Conclusion:

Three SNPs of the ADAM33 gene were significantly associated with COPD in the Kashmiri population of India. This study establishes the possible role of ADAM33 SNPS in the causation of COPD. Further studies across different geographical areas in the country will unravel the contribution of this gene in the causation of COPD in India.