Glutathione S-transferase mu 1 (GSTM1) and theta 1 (GSTT1) genetic polymorphisms and atopic asthma in children from Southeastern Brazil

Glutathione S-transferase gene polymorphism and asthma: a case-control study in a pediatric population

Aim: To carry out a case-control study of the association of GST gene polymorphisms in pediatric asthma-related oxidative stress. Materials & methods: Asthma patients (n = 250) and age-matched healthy subjects (n = 250) DNA were genotyped for GSTM1/GSTT1 (+/+, +/-, -/+ and -/-) frequencies using multiplex-PCR and plasma oxidative stress markers (examined spectrophotometrically). Results: Asthma patients had significantly more common null-genotype GSTM1^-/GSTT1^- (10.4%; p = 0.002) and elevated levels of malondialdehyde, protein carbonyl and 8-hydroxy-2-deoxyguanosine as compared with controls. In addition, the level of plasma glutathione, GST activity and ferric-reducing ability were significantly decreased as compared with controls. Conclusion: Our data revealed significant associations between GSTM1^-/GSTT1^- genotype and oxidative stress markers in asthmatic children, which may very likely contribute to increased incidence of bronchial asthma.

The Effect of Broccoli Sprout Extract on Seasonal Grass Pollen-Induced Allergic Rhinitis

Patients exposed to pollutants are more likely to suffer from allergic rhinitis and may benefit from antioxidant treatment. Our study determined if patients diagnosed with grass-induced allergic rhinitis could benefit from broccoli sprout extract (BSE) supplementation. In total, 47 patients were confirmed with grass-induced allergic rhinitis and randomized to one of four groups: group 1 (nasal steroid spray + BSE), group 2 (nasal steroid spray + placebo tablet), group 3 (saline nasal spray + BSE) and group 4 (saline nasal spray + placebo tablet). Peak Nasal Inspiratory Flow (PNIF), Total Nasal Symptoms Scores (TNSS) and nasal mucus cytokine levels were analyzed in samples collected before and after the 3-week intervention. Comparing before and after the intervention, PNIF improved significantly when comparing Groups 1 and 2, vs. placebo, at various time points (p ≤ 0.05 at 5, 15, 60 and 240 min) following nasal challenge, while TNSS was only statistically significant at 5 (p = 0.03), 15 (p = 0.057) and 30 (p = 0.05) minutes. There were no statistically significant differences in various cytokine markers before and after the intervention. Combining nasal corticosteroid with BSE led to the most significant improvement in objective measures.

Association of glutathione S-transferase M1 and T1 genotypes with asthma: A meta-analysis

BACKGROUND

We performed an updated meta-analysis to clarify the relationship between glutathione S-transferase Mu and theta (GSTM1 and GSTT1, respectively) null/positive genotypes and asthma.

METHODS

We performed a literature search using PubMed and Web of Science databases in August 2019. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the role of GSTM1 and GSTT1 genotypes in the risk of asthma.

RESULTS

Overall, we found a significant association with asthma risk in the general population for both the GSTM1 genotype (OR = 1.21; 95% CI: 1.07-1.35; P < .001; I = 69.5%) and the GSTT1 genotype (OR = 1.61; 95% CI: 1.30-2.00; P < .001; I = 83.6%). Moreover, significant associations between both genotypes and asthma risk were also found by age stratification. Furthermore, for GSTM1 we found significant associations in populations living in Asia, Europe, and Russia, but not in Africa. Conversely, for GSTT1, we found a significantly increased risk in populations living in Asia, Europe, Africa, and Russia. In addition, a significant association was found for both genotypes with a sample size <500, but not a sample size >2000.

CONCLUSION

Our meta-analysis provides evidence that GSTM1 and GSTT1 genotypes could be used as asthma-associated biomarkers.

A case report of idiopathic environmental intolerance: A controversial and current issue

In this case of idiopathic environmental intolerance, a little known disease characterized by many symptoms of irritation due to exposure to several toxic compounds, genetic analysis could be helpful in case of differential diagnosis issue.

Combined GSTM1 and GSTT1 null genotypes are strong risk factors for atherogenesis in a Serbian population

Oxidative stress (OS) plays an important role in atherogenesis and since glutathione S-transferases (GSTs) provide protection against OS, we have tested the hypothesis that deletion polymorphisms in two GSTs (GSTM1 and GSTT1) may affect the risk of developing atherosclerosis. A total of 382 individuals (200 patients with atherosclerosis and 182 healthy controls) were included in this association study. Genomic DNA was isolated from peripheral blood cells or from buccal epithelial cells and genotyping was performed using multiplex-PCR or real-time PCR methods. GSTM1 null genotype was significantly more frequent in atherosclerotic patients than in controls (52.0% vs 34.1%) and individuals with the GSTM1 null genotype had an approximately 2-fold increase in atherosclerosis risk (OR: 2.1, 95%CI=1.39-3.17, P=0.0004). GSTT1 null genotype alone did not show a statistically significant effect on atherosclerosis risk modulation, but the association approached significance (OR: 1.57, 95%CI=0.94-2.64, P=0.08). The combined analysis showed that the presence of both genes had a protective effect against atherosclerosis (OR=0.55, 95%CI=0.37-0.83, P=0.005) while double null genotypes led to a robust atherosclerosis risk increase (OR: 8.14, 95%CI= 2.41-27.51, P < 0.0001). This study demonstrated that the GSTM1 null and combined GSTM1/GSTT1 null genotypes are susceptibility factors for development of atherosclerosis in a Serbian population.

Distribution of genetic variants of oxidative stress metabolism genes: Paraoxonase 1 (PON1) and Glutathione S-transferase (GSTM1/GSTT1) in a population from Southeastern Mexico

BACKGROUND

Paraoxonase 1 (PON1) and glutathione S-transferases (GSTs) are involved in the biotransformation of xenobiotics. Variation in the enzyme concentration and activity suggests individual differences for the degree of protection against oxidative stress.

AIM

This study analysed the distribution of SNPs Q192R, L55M (PON1) and variants in GSTM1 and GSTT1 genes in a population from Southeastern Mexico.

SUBJECTS AND METHODS

One hundred and fifty-one Mexican Mestizo healthy volunteers were included. PON1 polymorphisms were determined by Taqman allele discrimination real time-PCR, whereas GSTM1 and GSTT1 genes were determined with a multiplex PCR-based method.

RESULTS

All genotypes were in Hardy-Weinberg equilibrium, except for GSTM1. The genotypic distributions of Q192R and L55M were 22% QQ, 48% QR, 30% RR, 62% LL, 34% LM and 4% MM, respectively, whereas the allele frequencies were 0.46 (Q), 0.54 (R), 0.79 (L) and 0.21 (M). The most frequent haplotype was R/L (46.7%). It was found that 31% and 9% of the individuals had the GSTM1 and GSTT1 null genotype, respectively. The frequency of the combined null genotype GSTM1*0/GSTT1*0 was 4.64%.

CONCLUSION

The results showed that the frequencies of polymorphisms of PON1, GSTM1 and GSTT1 in the Yucatán population differ to those observed in other ethnic groups and provide useful data for epidemiological studies.

Cigarette smoking, dietary habits and genetic polymorphisms in GSTT1, GSTM1 and CYP1A1 metabolic genes: A case-control study in oncohematological diseases

AIM

To analyze the association between oncohematological diseases and GSTT1/GSTM1/CYP1A1 polymorphisms, dietary habits and smoking, in an argentine hospital-based case-control study.

METHODS

This hospital-based case-control study involved 125 patients with oncohematological diseases and 310 control subjects. A questionnaire was used to obtain sociodemographic data and information about habits. Blood samples were collected, and DNA was extracted using salting out methods. Deletions in GSTT1 and GSTM1 (null genotypes) were addressed by PCR. CYP1A1 MspI polymorphism was detected by PCR-RFLP. Odds ratio (OR) and 95%CI were calculated to estimate the association between each variable studied and oncohematological disease.

RESULTS

Women showed lower risk of disease compared to men (OR 0.52, 95%CI: 0.34-0.82, P = 0.003). Higher levels of education (> 12 years) were significantly associated with an increased risk, compared to complete primary school or less (OR 3.68, 95%CI: 1.82-7.40, P < 0.001 adjusted for age and sex). With respect to tobacco, none of the smoking categories showed association with oncohematological diseases. Regarding dietary habits, consumption of grilled/barbecued meat 3 or more times per month showed significant association with an increased risk of disease (OR 1.72, 95%CI: 1.08-2.75, P = 0.02). Daily consumption of coffee also was associated with an increased risk (OR 1.77, 95%CI: 1.03-3.03, P = 0.03). Results for GSTT1, GSTM1 and CYP1A1 polymorphisms showed no significant association with oncohematological diseases. When analyzing the interaction between polymorphisms and tobacco smoking or dietary habits, no statistically significant associations that modify disease risk were found.

CONCLUSION

We reported an increased risk of oncohematological diseases associated with meat and coffee intake. We did not find significant associations between genetic polymorphisms and blood cancer.

Attenuation of lung fibrosis in mice with a clinically relevant inhibitor of glutathione-S-transferase π

Idiopathic pulmonary fibrosis (IPF) is a debilitating lung disease characterized by excessive collagen production and fibrogenesis. Apoptosis in lung epithelial cells is critical in IPF pathogenesis, as heightened loss of these cells promotes fibroblast activation and remodeling. Changes in glutathione redox status have been reported in IPF patients. S-glutathionylation, the conjugation of glutathione to reactive cysteines, is catalyzed in part by glutathione-S-transferase π (GSTP). To date, no published information exists linking GSTP and IPF to our knowledge. We hypothesized that GSTP mediates lung fibrogenesis in part through FAS S-glutathionylation, a critical event in epithelial cell apoptosis. Our results demonstrate that GSTP immunoreactivity is increased in the lungs of IPF patients, notably within type II epithelial cells. The FAS-GSTP interaction was also increased in IPF lungs. Bleomycin- and AdTGFβ-induced increases in collagen content, α-SMA, FAS S-glutathionylation, and total protein S-glutathionylation were strongly attenuated in Gstp-/- mice. Oropharyngeal administration of the GSTP inhibitor, TLK117, at a time when fibrosis was already apparent, attenuated bleomycin- and AdTGFβ-induced remodeling, α-SMA, caspase activation, FAS S-glutathionylation, and total protein S-glutathionylation. GSTP is an important driver of protein S-glutathionylation and lung fibrosis, and GSTP inhibition via the airways may be a novel therapeutic strategy for the treatment of IPF.

Asthma in Latin America

Consistent with the diversity of Latin America, there is profound variability in asthma burden among and within countries in this region. Regional variation in asthma prevalence is likely multifactorial and due to genetics, perinatal exposures, diet, obesity, tobacco use, indoor and outdoor pollutants, psychosocial stress and microbial or parasitic infections. Similarly, non-uniform progress in asthma management leads to regional variability in disease morbidity. Future studies of distinct asthma phenotypes should follow-up well-characterised Latin American subgroups and examine risk factors that are unique or common in Latin America (eg, stress and violence, parasitic infections and use of biomass fuels for cooking). Because most Latin American countries share the same barriers to asthma management, concerted and multifaceted public health and research efforts are needed, including approaches to curtail tobacco use, campaigns to improve asthma treatment, broadening access to care and clinical trials of non-pharmacological interventions (eg, replacing biomass fuels with gas or electric stoves).

Gender-dependent effect of GSTM1 genotype on childhood asthma associated with prenatal tobacco smoke exposure

It remains unclear whether the GSTM1 genotype interacts with tobacco smoke exposure (TSE) in asthma development. This study aimed to investigate the interactions among GSTM1 genotype, gender, and prenatal TSE with regard to childhood asthma development. In a longitudinal birth cohort in Taiwan, 756 newborns completed a 6-year follow-up, and 591 children with DNA samples available for GSTM1 genotyping were included in the study, and the interactive influences of gender-GSTM1 genotyping-prenatal TSE on childhood asthma development were analyzed. Among these 591 children, 138 (23.4%) had physician-diagnosed asthma at 6 years of age, and 347 (58.7%) were null-GSTM1. Prenatal TSE significantly increased the prevalence of childhood asthma in null-GSTM1 children relative to those with positive GSTM1. Further analysis showed that prenatal TSE significantly increased the risk of childhood asthma in girls with null-GSTM1. Furthermore, among the children without prenatal TSE, girls with null-GSTM1 had a significantly lower risk of developing childhood asthma and a lower total IgE level at 6 years of age than those with positive GSTM1. This study demonstrates that the GSTM1 null genotype presents a protective effect against asthma development in girls, but the risk of asthma development increases significantly under prenatal TSE.

Significant association between asthma risk and the GSTM1 and GSTT1 deletion polymorphisms: an updated meta-analysis of case-control studies

Polymorphisms in GSTM1 and GSTT1 may be associated with asthma risk, yet several studies and meta-analyses have reported inconclusive results. Therefore, an updated meta-analysis was conducted. Literature searches were performed using the Pubmed, Embase and Web of Science databases until October 2012. Variant 'null' genotype was compared with wild-type 'present' in the pooled data. All statistical analyses were performed using STATA 11.0. A total of 26 case-control studies were suitable for inclusion in the meta-analysis. In the overall population, a significant association was found for both the GSTM1 (odds ratio (OR) = 1.452; 95% confidence interval (CI): 1.192-1.770) and GSTT1 polymorphism (OR = 1.792; 95% CI:1.293-2.483). For subgroup analysis by age, GSTM1 significantly increased risk for both children (OR = 1.368; 95% CI: 1.051-1.781) and adults (OR = 1.859; 95% CI: 1.183-2.921). For GSTT1, a significant association was only found in the adult population (OR = 2.312; 95%CI: 1.204-4.439). Based on subgroup analysis by ethnicity, a significant association for GSTM1 was found in Europe (OR = 1.303; 95% CI: 1.018-1.667), Africa (OR = 2.175; 95%CI: 1.560-3.031) and Latin America (OR = 2.265; 95%CI: 1.375-3.729). For GSTT1, significantly increased risk was found only for Asian (OR = 2.105; 95% CI: 1.101-4.025) and Russian (OR = 2.747; 95% CI: 1.071-7.046) populations. This meta-analysis provides evidence that GSTM1 and GSTT1 polymorphisms may be risk factors for asthma.

Glutathione S transferase theta1 and mu1 gene polymorphisms and phenotypic expression of asthma in Egyptian children: a case-control study

Background

Asthma is the result of a complex interaction between environmental factors and genetic variants that confer susceptibility. The glutathione S-transferases (GSTT1 and GSTM1) are phase II enzymes thought to protect the airways from oxidative stress. Few and contradictory data are available on the association between asthma development and GSTT1 and GSTM1 polymorphisms in different ethnic groups. The current study aimed to investigate whether these polymorphisms are associated with asthma development in the Egyptian population.

Methods

The cross-sectional study was performed on 94 asthmatic children 6 -12 yrs and 90 matched healthy controls. Candidates were subjected to clinical evaluation and measurement of absolute blood eosinophilic count, total serum IgE, and GSTT1 and GSTM1 genotype by multiplex PCR technique.

Results

The results for GSTT1 null genotype were 87.2% and 97.2% for asthmatic children and controls respectively and showed to be significantly more in controls (P =0.007, OR:0.683, CI: 0.034 -0.715). The results for GSTM1 null genotype were 50% and 61.1% for asthmatic children and controls respectively and showed to be nonsignificant (p = 0.130, OR: 1.000, CI: 0.54- 1.86). Also, no association was detected between GSTT1 and GSTM1 polymorphisms and atopic conditions or asthma severity.

Conclusion

The significant detection of GSTT1 null genotype more in controls than in asthmatics with no association with other atopic manifestations or asthma severity and the lack of association detected between GSTM1 polymorphism in relation to asthma, atopy or asthma severity confirm the uncertain role of those genes in the development of asthma.

Quantitative assessment of the association between the GSTM1-null genotype and the risk of childhood asthma

BACKGROUND

Many studies investigated the association between the glutathione S-transferase M 1 (GSTM1)-null genotype and childhood asthma risk, but there was obvious inconsistence among those studies. The aim of this meta-analysis was to quantify the strength of association between the GSTM1-null genotype and risk of childhood asthma.

METHODS

We searched the PubMed, Embase, and Wangfang databases for studies relating the association between the GSTM1-null genotype and risk of childhood asthma. We estimated the pooled odds ratio (OR) with its 95% confidence interval (95% CI) to assess the association.

RESULTS

Nineteen case-control studies with 4,543 childhood asthma cases and 19,394 controls were included into this meta-analysis. Meta-analysis of all 19 studies showed that the GSTM1-null genotype was associated with increased risk of childhood asthma (OR=1.17, 95% CI 1.03-1.34, p=0.017). Subgroup analyses by ethnicity suggested that the GSTM1-null genotype was associated with an increased risk of childhood asthma in Caucasians and Africans (for Caucasians, fixed-effects OR=1.16, 95% CI 1.07-1.27, p=0.001; for Africans, fixed-effects OR=1.92, 95% CI 1.35-2.74, p<0.001). The cumulative meta-analyses showed a trend of obvious association between the GSTM1-null genotype and risk of childhood asthma as information accumulated in the analyses of both total studies and Caucasians. No evidence of publication bias was observed.

CONCLUSION

Meta-analyses of available data suggest a significant association between the GSTM1-null genotype and the risk of childhood asthma, and the GSTM1-null genotype contributes to increased risk of childhood asthma, especially in Caucasians and Africans.

Glutathione S-transferase polymorphisms, asthma susceptibility and confounding variables: a meta-analysis

Oxidative stress is one of the main risk factors for asthma development. Glutathione S-transferases play an important role in antioxidant defences and may influence asthma susceptibility. In particular, GSTM1 and GSTT1 positive/null genotypes and the GSTP1 Ile105 Val polymorphism have been analyzed in a number of genetic association studies, with conflicting outcomes. Two previous meta-analyses have attempted to clarify the associations between GST genes and asthma, but these studies have also showed contrasting results. Our aim was to perform a meta-analysis that included independent genetic association studies on GSTM1, GSTP1, and GSTT1, evaluating also the effect of potential confounding variables (i.e. ethnicity, population age, and urbanization). Systematic review and meta-analysis of the effects of GST genes on asthma were conducted. The meta-analyses were performed using a fixed or, where appropriate, random effects model. The meta-analysis of the GSTM1 (n = 35), GSTT1 (n = 31) and GSTP1 (n = 28) studies suggests that no significant associations with asthma susceptibility were observed for GSTM1 and GSTP1 gene polymorphisms, whereas a significant outcome was detected for the GSTT1 positive/null genotype (pooled OR = 1.33, 95 %CI = 1.10-1.60). However, high between-study heterogeneity was identified in all the general analyses (p heterogenetity < 0.05). The stratification analysis seems to explain the heterogeneity only in few cases. This picture is probably due to the interactive process of genetics and environment that characterizes disease pathogenesis. Further studies on interactions of GST genes with the potential oxidative stress sources and with other antioxidant genes are needed to explain the role of GST enzymes in asthma.

Significant association between GSTT1 null genotype and risk of asthma during childhood in Caucasians

Asthma is a complex multifactorial disorder and its management requires a better understanding of its various pathogenesis and mechanisms. Previous studies assessing the association between glutathione S-transferase T1 (GSTT1) null genotype and asthma risk during childhood reported conflicting results. To get a more precise estimation of the association between GSTT1 null genotype and risk of asthma during childhood, we performed a meta-analysis of 16 studies with a total of 18,558 subjects. Subgroup analyses were performed by ethnicity. The pooled odds ratio (OR) with corresponding 95 % confidence interval (95 %CI) was used to assess the association. Overall, there was a significant association between GSTT1 null genotype and increased risk of children asthma (OR = 1.25, 95 % CI, 1.02-1.54; P = 0.032). Subgroup analyses showed GSTT1 null genotype was associated with increased risk of children asthma in Caucasians (OR = 1.46, 95 % CI, 1.04-2.03; P = 0.027), but not in Asians (OR = 1.03, 95 % CI, 0.55-1.94; P = 0.928) and Africans (OR = 1.33, 95 % CI, 0.92-1.91; P = 0.127). There was no evidence of publication bias in the subgroup analysis of Caucasians. In conclusion, there is a significant association between GSTT1 null genotype and risk of asthma during childhood in Caucasians. More well-designed epidemiological studies are needed to further assess this association in Asians and Africans.

GSTT1 and GSTM1 gene polymorphisms as major risk factors for asthma in a North Indian population

BACKGROUND

According to the National Family Health Survey, asthma is one of the leading diseases in India. In order to understand the complexity of asthma, the susceptibility genes need to be targeted for their association. Glutathione S-transferases play a major role in the detoxification of metabolites of oxidative stress resulting in inflammation and asthma. In the present study, the hypothesis that GSTT1 and GSTM1 gene polymorphisms are associated with asthma was examined.

METHODS

This is the first study to investigate the role of GSTT1 and GSTM1 gene polymorphisms in asthma pathogenesis in a North Indian population. A total of 824 subjects were recruited, of which 410 were asthma patients, including 323 patients suffering from allergic rhinitis. The other 414 recruits were healthy controls from regions of North India. Multiplex PCR was used for genotyping the GSTT1 and GSTM1 gene polymorphisms.

RESULTS

The GSTT1 null allele was more prevalent in asthma patients (40 %) than in the control subjects (13.3 %), which yielded a nearly fourfold risk towards asthma with odds ratio (OR) (95 % CI) = 4.35 (3.04-6.24), χ(2) = 75.34, and p = 0.000. The GSTM1 polymorphism also revealed a greater prevalence of the GSTM1 null allele in asthma patients (46.6 %) than in controls (39.4 %). Statistical analysis yielded a marginal risk toward asthma with OR (95 % CI) = 1.34 (1.01-1.79), χ(2) = 4.37, and p = 0.036.

CONCLUSIONS

Polymorphisms as a result of deletions in the GSTT1 and GSTM1 genes confer an increased risk towards asthma thereby suggesting the protective role of these functional genes in the development of the disease.

Impact of glutathione-S-transferase gene polymorphisms on enzyme activity, lung function and bronchial asthma susceptibility in Egyptian children

BACKGROUND

Asthma is a complex multifactorial disease with an obvious genetic predisposition. Polymorphisms of the glutathione-S-transferase (GST) genes are known risk factors for some environmentally-related diseases. The aim of the present study was to investigate the role of polymorphisms in the GSTT1, GSTM1 and GSTP1 genes and asthma susceptibility in Egyptian children, and to analyze their effect on GST activity and lung function.

METHODS

GSTT1 and GSTM1 gene polymorphism was genotyped using the multiplex polymerase chain reaction (PCR) and GSTP1 ILe105Val polymorphism was determined using PCR-restriction fragment length polymorphism (PCR-RFLP) in 168 healthy and 126 asthmatic children (82 atopic and 44 nonatopic). Also GST enzyme activity and lung function were evaluated.

RESULTS

Asthmatic children had a significant higher prevalence of the GSTM1 null (P=0.003) and significant lower prevalence of GSTP1 Val/Val genotypes (P=0.02) than control group. Lung function was significantly decreased in GSTM1 null genotype and GSTP1 Ile/Ile genotype. GSTP1 Val/Val genotypes and GSTM1 null genotype had a significant decrease in plasma GST activity.

CONCLUSIONS

GST genes polymorphisms may play an important role in pathogenesis and susceptibility to asthma in children.