Association between ADAM33 polymorphisms and susceptibility with adult and childhood asthma among Jordanians

ADAM33's Role in Asthma Pathogenesis: An Overview

Asthma is a complex chronic respiratory disease characterized by airway hyperresponsiveness, inflammation, and obstruction. Many genes have been identified as associated with asthma but none with such substantial significance as the ADAM33 gene due to its role in airway remodeling and bronchial hyperresponsiveness. This review summarizes the current knowledge on the genetic and functional aspects of ADAM33 in asthma pathogenesis. We highlight its genetic variants associated with asthma susceptibility and severity, as well as the functional effects of ADAM33 on airway remodeling, smooth muscle cell proliferation, and its interplay with environmental factors. Additionally, we discuss the potential clinical implications of ADAM33 as a therapeutic target for asthma management.

Asthma susceptible genes in children: A meta-analysis

BACKGROUND

During the last decade, a number of studies have evaluated the potential association between some genetic polymorphisms and childhood asthma risk, however, the results of published studies appear conflicts. The aim of the present study was to investigate association between genetic polymorphisms and pediatric asthma.

METHODS

Relevant studies were searched in PubMed, Embase, Web of Science, CNKI (China National Knowledge Infrastructure), Wanfang, and Weipu database. Pooled odds ratios (OR) with 95% confidence interval (CI) were calculated to evaluate the strength of the associations.

RESULTS

Fifty five case-control studies were finally included in this meta-analysis, including 17,971 pediatric asthma cases and 17,500 controls. Eighteen polymorphisms were identified, of which, 9 polymorphisms were found to be associated with asthma risk in overall populations: IL-13 +2044G/A, IL-4 -590C/T, ADAM33 F+1, ADAM33 T2, ADAM33 T1, ADAM33 ST+4,ORMDL3 rs7216389, VDR FokI, VDR TaqI. Furthermore, IL-13 +2044G/A, IL-4 -590C/T, ADAM33 T2, ADAM33 T1, VDR BsmI polymorphisms may cause an increased risk of asthma among Chinese children.

CONCLUSIONS

This meta-analysis found that IL-13 +2044G/A, IL-4 -590C/T, ADAM33 F+1, ADAM33 T2, ADAM33 T1, ADAM33 ST+4,ORMDL3 rs7216389, VDR FokI, and VDR TaqI polymorphisms might be risk factors for childhood asthma. Further study with large population and more ethnicities is needed to estimate these associations.

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.

Association between ADAM33 polymorphisms and asthma risk: a systematic review and meta-analysis

Background

Asthma is a common complex chronic, inflammatory polygenic disease with heterogeneous manifestations, affecting individuals of all age groups and posing an immense burden on healthcare resources. A number of studies have identified the association between a disintegrin and metalloprotease 33 (ADAM33) polymorphisms and asthma risk, however, the results still remain inconclusive. The objective of the present study was to identify the effect of ADAM33 variants in asthma susceptibility.

Methods

Eligible case-control studies published between January 2000 and June 2018 was searched and retrieved from online electronic databases. The odds ratio (OR) with its 95% confidence interval (CI) was employed to calculate the effect.

Results

A total of 63 case-control studies were finally screened out, including 13,280 asthma patients and 13,340 controls. Eleven SNPs of ADAM33 gene were identified. Our results detected a significant association between ADAM33 T2, Q1, F + 1 and AA genotype of T + 1 polymorphisms and asthma risk in total population. Subgroup analysis by ethnicities showed that the alleles and genotypes of T2, Q1 and F + 1 polymorphisms were associated with asthma susceptibility among Asian populations, while V4 polymorphism was associated with asthma among Caucasian populations. Subgroup analysis by ages showed that T2, F + 1 and ST + 4 polymorphisms were associated with childhood asthma, while Q1 and V4 polymorphisms were associated with asthma risk in adults. Subgroup analysis by asthma severity showed that only the G allele of ADAM33 T1 polymorphism was associated with the severity of asthma when compared with the controls. In addition, T2, Q1 and F + 1 polymorphisms of ADAM33 were significantly associated with increased the asthma risk in Chinese asthma patients.

Conclusions

Our results found that T2, Q1 and F + 1 polymorphisms of ADAM33 gene might contribute to asthma risk. Future well-designed case-control studies with large population and more ethnicities are still needed to estimate the association.

An intronic single-nucleotide polymorphism (rs13217795) in FOXO3 is associated with asthma and allergic rhinitis: a case-case-control study

BACKGROUND

Asthma and allergic rhinitis are respiratory diseases with a significant global burden. Forkhead box O3 (FOXO3) is a gene involved in the etiology of a number of respiratory diseases. The objective of this study is to assess the association of rs13217795, an intronic FOXO3 single-nucleotide polymorphism, with asthma and allergic rhinitis.

METHODS

In this case-case-control genetic association study, genotyping was conducted using the PCR-RFLP method. Genotype-based associations were investigated under the general, recessive, and dominant models of disease penetrance using binomial logistic regression; and, allele-based associations were tested using Pearson's chi-squared test.

RESULTS

The final study population consisted of 94 controls, 124 asthmatics, and 110 allergic rhinitis patients. The general and recessive models of disease penetrance were statistically significant for both case-control comparisons. Under the general model, the odds of the asthma phenotype were 1.46 (0.64 to 3.34) and 3.42 (1.37 to 8.57) times higher in heterozygotes and derived allele homozygotes, respectively, compared to ancestral allele homozygotes. The corresponding odds ratios for the allergic rhinitis phenotype were 1.05 (0.46 to 2.40) and 2.35 (0.96 to 5.73), respectively. The dominant model of disease penetrance was not statistically significant. The minor allele in all study groups was the ancestral allele, with a frequency of 0.49 in controls. There was no deviation from Hardy-Weinberg equilibrium in controls. Both case-control allele-based associations were statistically significant.

CONCLUSIONS

Herein we present the first report of the association between rs13217795 and allergic rhinitis, and the first independent verification of the association between rs13217795 and asthma. Marker selection in future genetic association studies of asthma and allergic rhinitis should include functional polymorphisms in linkage disequilibrium with rs13217795.

T1 polymorphism in a disintegrin and metalloproteinase 33 (ADAM33) gene may contribute to the risk of childhood asthma in Asians

OBJECTIVE

Polymorphisms in ADAM33 gene have been implicated in susceptibility to the risk of childhood asthma. However, the results remain controversial. We performed meta-analyses to clarify the relationship between them.

METHODS

Relevant articles were searched in PubMed, Embase, Wanfang, and China National Knowledge Infrastructure. The Odds ratio (OR) with 95% confidence interval (CI) was used to assess the strength of the associations.

RESULTS

Fourteen studies with five ADAM33 polymorphisms (F + 1, T1, T2, S2, and V4) were identified, involving 2687 cases and 2996 controls. ADAM33 F + 1, T2, and T1 polymorphisms showed significant associations with asthma risks in the overall and Caucasian children, Asian children, and Caucasian and Chinese children, respectively; however, these significant results were unstable in sensitivity analysis. T1 revealed significant and stable associations with asthma risks among Asian children in the dominant (OR = 2.00, 95% CI = 1.40-2.87, P = 0.0002) and codominant (OR = 3.06, 95% CI = 1.71-5.50, P = 0.0002) models; in cumulative meta-analyses, these significant results were robust. Concerning S2 or V4 polymorphism, no significant associations were observed.

CONCLUSION

These findings demonstrate that ADAM33 T1 polymorphism might be a potential susceptible predictor of asthma for Asian children. Further functional studies between this polymorphism and asthma risks are warranted.

Association of TLR4 (896A/G and 1196C/T) Gene Polymorphisms with Asthma Risk: A Meta-Analysis

Background

Conflicting data have been reported on the association between Toll-like receptor 4 (TLR4) +896A/G and +1196C/T polymorphisms and the risk of asthma. Therefore, we conducted this meta-analysis to clarify the effect of TLR4 +896A/G and +1196C/T polymorphisms on the risk of asthma.

Material/Methods

An electronic literature search was performed using PubMed, Embase, Web of Science, Chinese National Knowledge Infrastructure (CNKI), and Wanfang Data to find relevant studies. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of the associations. All statistical analyses were conducted using STATA software version 12.0.

Results

A total of 14 studies with 2873 asthma cases and 3110 controls were included. The pooled results indicated a significant association between TLR4 +1196C/T polymorphism and the risk of asthma (T vs. C: OR=0.79, 95%CI=0.63–0.99, P=0.04; TT+CT vs. CC: OR=0.76, 95%CI=0.59–0.96, P=0.03; CT vs. CC: OR=0.74, 95%CI=0.58–0.95, P=0.02). In subgroup analysis by ethnicity, TLR4 +1196C/T polymorphism was significantly associated with asthma risk in Asians (T vs. C: OR=0.73, 95%CI=0.54–0.98, P=0.04; TT+CT vs. CC: OR=0.70, 95%CI=0.51–0.96, P=0.03; CT vs. CC: OR=0.69, 95%CI=0.50–0.96, P=0.03), but not in whites. For TLR4 +896A/G polymorphism, no significant association was found between TLR4 +896A/G polymorphism and asthma risk under any genetic models.

Conclusions

The results of this meta-analysis suggest that T allele of the TLR4 +1196C/T might act as a protective factor against the development of asthma.

The ADAM33 S2 polymorphism is associated with susceptibility to pediatric asthma in the Chinese Han population

BACKGROUND

The disintegrin and metalloprotease domain containing protein 33 (ADAM33) is a novel susceptibility gene for asthma and airway hyperresponsiveness, particularly in the Asian population. We investigated the influence of ADAM33 polymorphisms on the serum levels of ADAM33 and the susceptibility to pediatric asthma in the Chinese Han population.

METHODS

Polymerase chain reaction-restriction fragment length polymorphism analysis was employed to study the genotypic distribution of F+1, T1, and S2 in ADAM33 in a cohort of 120 pediatric asthma patients and 105 healthy controls. The serum levels of secreted ADAM33 protein were measured in all the study subjects using the enzyme-linked immunosorbent assay (ELISA).

RESULTS

This case-control study showed that the distribution of F+1 and T1 genotypes of ADAM33 was not significantly different between pediatric asthma patients and healthy controls (p > 0.05); however, the genotype and allele frequencies of the S2 polymorphism were significantly different between asthmatic patients and healthy controls (both p < 0.05). In addition, the frequency of CGC and CGG haplotypes exhibited statistically significant differences, with lower CGC and higher CGG frequencies found in the case group compared to the control group. Finally, in comparison to healthy controls, the serum levels of ADAM33 protein were significantly lower in patients carrying the S2 polymorphism.

CONCLUSION

Our results provide evidence that the ADAM33 S2 polymorphism is associated with increased susceptibility to pediatric asthma and that the CGG haplotype for the F+1, T1, and S2 polymorphisms is associated with an elevated risk of pediatric asthma in the Han population, whereas the CGC haplotype appears to confer a protective effect. Our results may prove useful for population-based screening to affect early intervention.