Frequency of polymorphism -262 c/t in catalase gene and oxidative damage in Slovak children with bronchial asthma

Sickle Cell Anemia: Variants in the CYP2D6, CAT, and SLC14A1 Genes Are Associated With Improved Hydroxyurea Response

Differences in hydroxyurea response in sickle cell anemia may arise due to a series of factors with genetic factors appearing to be predominant. This study aims to investigate the effects of single nucleotide polymorphisms in genes encoding drug-metabolizing enzymes and solute carriers on hydroxyurea response, in patients with sickle cell anemia. For that purpose, a total number of 90 patients with sickle cell anemia were recruited, 45 were undergoing hydroxyurea treatment, while 45 were not under the treatment. Association analyses were performed between CYP3A4 (rs2740574), CYP2D6 (rs3892097), CAT (rs7943316 and rs1001179), and SLC14A1 (rs2298720) variants and laboratory parameters. According to our findings, patients with hydroxyurea treatment demonstrated higher HbF levels and a significant improvement in hemolytic, hepatic, inflammatory, and lipid parameters in comparison to those without the treatment. We also found significant associations between the CYP2D6 (rs3892097), CAT (rs7943316 and rs1001179), and SLC14A1 (rs2298720) variants and an improvement of the therapeutic effects, specifically the hemolytic, hepatic, inflammatory, lipid, and renal parameters. In conclusion, our results highlight the importance of the investigated variants, and their strong association with hydroxyurea efficacy in patients with sickle cell anemia, which may be considered in the future as genetic markers.

Cellular and Molecular Events in the Airway Epithelium Defining the Interaction Between House Dust Mite Group 1 Allergens and Innate Defences

Serodominant group 1 allergens of house dust mites (HDMs) are cysteine protease digestive enzymes. By increasing the detection of any allergen by dendritic antigen presenting cells, upregulating inflammatory signalling molecules, and activating cells crucial to the transition from innate to acquired immune responses, the proteolytic activity of these HDM allergens also underlies their behaviour as inhalant allergens. The significance of this property is underlined by the attenuation of allergic responses to HDMs by novel inhibitors in experimental models. The group 1 HDM allergens act as prothrombinases, enabling them to operate the canonical stimulation of protease activated receptors 1 and 4. This leads to the ligation of Toll-like receptor 4, which is an indispensable component in HDM allergy development, and reactive oxidant-regulated gene expression. Intermediate steps involve epidermal growth factor receptor ligation, activation of a disintegrin and metalloproteases, and the opening of pannexons. Elements of this transduction pathway are shared with downstream signalling from biosensors which bind viral RNA, suggesting a mechanistic linkage between allergens and respiratory viruses in disease exacerbations. This review describes recent progress in the characterisation of an arterial route which links innate responses to inhaled allergens to events underpinning the progression of allergy to unrelated allergens.

Interaction Between Catalase Gene Promoter Polymorphisms and Indoor Environmental Exposure in Childhood Allergic Rhinitis

BACKGROUND

Allergic rhinitis (AR) is a highly prevalent chronic inflammatory disease affecting nearly 40% of the children in Taiwan. Genetic susceptibility may interact with specific environmental factors leading to allergic disease development.

METHODS

To assess the interactions between catalase gene promoter polymorphisms and environmental factors on the risk of AR, we conducted a case-control study in Taiwan. Data on AR and environmental factors were collected from 800 children using the ISSAC questionnaire. The case group consisted of 263 children with AR, and the control group consisted of =537 healthy children. Genotyping was performed for rs1001179 and rs769214 polymorphisms, and environmental exposure was assessed using four indicators including dwelling visible molds, mold odor, moisture on surfaces, and water damage.

RESULTS

We found that the presence of visible molds, mold odor, and moisture was associated with AR. An apparent joint effect of the GG genotype and mold odor, compared with the AA and AG combined genotypes and without any exposure indicator (adjusted odds ratio [OR] = 1.95 [95% confidence interval (CI) = 1.20, 3.18]; interaction adjusted odds ratio = 2.59 [95% CI = 1.27, 5.30]), was observed.

CONCLUSIONS

Our findings suggest that gene-environment interactions between the catalase polymorphism rs769214 and mold odor may play an important role in childhood AR development.

The participation of oxidative stress in the pathogenesis of bronchial asthma

Reactive oxygen species are produced during oxygen reduction and are characterized by high reactivity. They participate in many important physiological processes, but if produced in high concentrations they lead to oxidative stress development and disturb pro-oxidative/anti-oxidative balance towards the oxidation reaction - leading to damage of lipids, proteins, carbohydrates or nucleic acids. Asthma is a chronic inflammatory disease of the airways of various pathogenesis and clinical symptoms, prevalence in recent years has increased significantly. Recently published literature point out the involvement of reactive oxygen species in the pathogenesis of asthma. Changes in the protein and lipid oxidation lead, among others, to pathological changes in the respiratory epithelial cells, an increase in vascular permeability, mucus overproduction, smooth muscle contraction or airway hyperresponsiveness (AHR). The aim of this study is to present the current state of knowledge on the influence of oxidative stress parameters on asthma development.

Vulnerability of white matter tracts and cognition to the SOD2 polymorphism: A preliminary study of antioxidant defense genes in brain aging

Oxidative stress is a key mechanism of the aging process that can cause damage to brain white matter and cognitive functions. Polymorphisms in the superoxide dismutase 2 (SOD2) and catalase (CAT) genes have been associated with abnormalities in antioxidant enzyme activity in the aging brain, suggesting a risk for enhanced oxidative damage to white matter and cognition among older individuals with these genetic variants. The present study compared differences in white matter microstructure and cognition among 96 older adults with and without genetic risk factors of SOD2 (rs4880) and CAT (rs1001179). Results revealed higher radial diffusivity in the anterior thalamic radiation among SOD2 CC genotypes compared to CT/TT genotypes. Further, the CC genotype moderated the relationship between the hippocampal cingulum and processing speed, though this did not survive multiple test correction. The CAT polymorphism was not associated with brain outcomes in this cohort. These results suggest that the CC genotype of SOD2 is an important genetic marker of suboptimal brain aging in healthy individuals.

Advance of antioxidants in asthma treatment

Asthma is an allergic disease, characterized as a recurrent airflow limitation, airway hyperreactivity, and chronic inflammation, involving a variety of cells and cytokines. Reactive oxygen species have been proven to play an important role in asthma. The pathogenesis of oxidative stress in asthma involves an imbalance between oxidant and antioxidant systems that is caused by environment pollutants or endogenous reactive oxygen species from inflammation cells. There is growing evidence that antioxidant treatments that include vitamins and food supplements have been shown to ameliorate this oxidative stress while improving the symptoms and decreasing the severity of asthma. In this review, we summarize recent studies that are related to the mechanisms and biomarkers of oxidative stress, antioxidant treatments in asthma.

Association of Gene Polymorphisms in Interleukin 6 in Infantile Bronchial Asthma

INTRODUCTION

The genetic background of bronchial asthma is complex, and it is likely that multiple genes contribute to its development both directly and through gene-gene interactions. Cytokines contribute to different aspects of asthma, as they determine the type, severity and outcomes of asthma pathogenesis. Allergic asthmatics undergoing an asthmatic attack exhibit significantly higher levels of pro-inflammatory cytokines, such as interleukins and chemokines. In recent years, cytokines and their receptors have been shown to be highly polymorphic, and this prompted us to investigate interleukin 6 promoter polymorphisms at position -174G/C (rs1800795) and at -572G/C (rs1800796) in relation to asthma in children.

METHODS

Interleukin 6 promoter polymorphisms were analyzed in bronchial asthma patients and healthy children using polymerase chain reaction-restriction fragment length polymorphism analysis.

RESULTS

We observed a significant association between polymorphism at -174G/C and bronchial asthma (OR=3.4, 95% CI: 2.045-5.638, P<.001). Higher associations between polymorphism at IL-6 -174G/C and bronchial asthma were observed in atopic patients (OR=4.1, 95% CI: 2.308-7.280, P<8.10^-7).

CONCLUSIONS

Interleukin 6 polymorphism is associated with bronchial asthma, particularly its atopic phenotype. Expression and secretion of interleukins in asthmatic patients may be affected by genetic polymorphisms, and could have a disease-modifying effect in the asthmatic airway and modify the therapeutic response.

Oxidative Stress and Bronchial Asthma in Children-Causes or Consequences?

Bronchial asthma is one of the most common chronic inflammatory diseases of the airways. In the pathogenesis of this disease, the interplay among the genes, intrinsic, and extrinsic factors are crucial. Various combinations of the involved factors determine and modify the final clinical phenotype/endotype of asthma. Oxidative stress results from an imbalance between the production of reactive oxygen species and reactive nitrogen species and the capacity of antioxidant defense mechanisms. It was shown that oxidative damage of biomolecules is strongly involved in the asthmatic inflammation. It is evident that asthma is accompanied by oxidative stress in the airways and in the systemic circulation. The oxidative stress is more pronounced during the acute exacerbation or allergen challenge. On the other hand, the genetic variations in the genes for anti-oxidative and pro-oxidative enzymes are variably associated with various asthmatic subtypes. Whether oxidative stress is the consequence of, or the cause for, chronic changes in asthmatic airways is still being discussed. Contribution of oxidative stress to asthma pathology remains at least partially controversial, since antioxidant interventions have proven rather unsuccessful. According to current knowledge, the relationship between oxidative stress and asthmatic inflammation is bidirectional, and genetic predisposition could modify the balance between these two positions-oxidative stress as a cause for or consequence of asthmatic inflammation.

The association between antioxidant enzyme polymorphisms and cerebral palsy after perinatal hypoxic-ischaemic encephalopathy

BACKGROUND

Hypoxic-ischaemic perinatal brain injury leads to the formation of reactive oxygen species (ROS) and the resultant cell and tissue damage may cause neurological sequelae such as cerebral palsy and/or epilepsy. A decrease in the capacity for defending against ROS may increase the susceptibility to cerebral palsy. The aim of this study was to investigate the impact of common functional polymorphisms in the antioxidant genes SOD2, GPX1 and CAT, associated with a decreased capacity for defending against ROS, in patients with perinatal hypoxic-ischaemic encephalopathy (HIE).

METHODS

80 patients previously diagnosed with perinatal HIE were included. Genomic DNA was isolated from buccal swabs and genotyped for SOD2 rs4880, GPX1 rs1050450 and CAT rs1001179 using real-time PCR-based methods.

RESULTS

Among patients with neonatal HIE, carriers of at least one polymorphic CAT rs1001179 T allele were significantly associated with development of cerebral palsy compared to non-carriers (univariate logistic regression, p = 0.026; OR = 3.36; 95% CI = 1.16-9.76). This difference remained statistically significant after accounting for prematurity. The investigated SOD2 and GPX1 polymorphisms were not associated with cerebral palsy after perinatal HIE.

CONCLUSION

CAT rs1001179 polymorphism could be used to identify children that have a higher susceptibility to cerebral palsy after perinatal HIE.

Oxidative Stress and Catalase Gene

We studied the frequency of alleles and genotypes of CAT gene -262C>T polymorphism (rs1001179) in Russian and Buryat adolescents. The frequency of -262T allele was 28.31% in Russians and 16.84% in Buryats (p<0.01). In both ethnic groups, a correlation between the study polymorphism and concentration of diene conjugates was observed. Carriers of TT-genotype of CAT gene-262C>T polymorphism had lower level of diene conjugates than carriers of CT- and CC-genotypes.

Superoxide Dismutase and Catalase Genotypes in Pediatric Migraine Patients

This study compared superoxide dismutase (SOD) and catalase (CAT) alleles in 97 consecutive children and adolescents with migraine to 96 healthy children and adolescents. Isolated genomic DNA was used as a template for SOD1 (35 A/C), SOD2 16 C/T, and CAT2 [(-262 C/T) and (-21 A/T)] allele genotyping. The SOD2 16 C/T genotype and C allele frequency differed significantly between controls and migraine (P = .047; P = .038). CAT -21 AA genotype and A allele frequency were significantly higher in both migraine with aura patients (P = .013; P = .004) and migraine without aura patients (P = .003; P = .001) compared to controls. To our knowledge, this is the first demonstration of differences in SOD and CAT genotypes between pediatric migraine patients and age-matched controls. Further studies on the functional implications of these genetic variants on neural antioxidant capacity and the use of antioxidant modulators for migraine treatment are warranted.

Associations of IL-2 and IL-4 Expression and Polymorphisms With the Risks of Mycoplasma pneumoniae Infection and Asthma in Children

INTRODUCTION

Asthma is an inflammatory disorder of the airways and the symptoms of asthma could be exacerbated by Mycoplasma pneumoniae infection. Interleukin-2 and interleukin-4 have been implicated in immune and inflammatory reactions. We examined the associations of IL2 and IL4 polymorphisms and expression with the risks of asthma and M. pneumoniae infection in children.

METHODS

392 asthmatic children and 849 controls were recruited into the study. Eight polymorphisms in IL2 and IL4 were genotyped with Sequenom MassARRAY platform. M. pneumoniae infection and copy number was determined with fluorescence PCR. IL-2 and IL-4 serum expression levels were determined by using ELISA.

RESULTS

We found a significant association of IL2 rs6534349 polymorphism with increased asthma risk (heterozygotes, P=.029; homozygous variants; P=.013) and of IL4 rs2227284 polymorphism with reduced asthma risk (heterozygotes, P=.026; homozygous variants; P=.001). Besides, the association of other polymorphisms, except rs2070874 polymorphism, became apparent when the asthmatic children were grouped according to GINA classification of asthma control and severity. In addition, IL-2 and IL-4 serum expression levels were significantly higher in M. pneumoniae negative (P=.038) and positive (P=.011) subjects respectively. This observation holds true among asthmatic patients (P=.016 for IL-2 and P=.042 for IL-4), but only the IL-4 observation remained correct among non-asthmatic controls (P=.032). We also observed that the rs6534349 GG genotype was significantly associated with increased odds of getting high load M. pneumoniae infection (P=.0376).

CONCLUSIONS

IL2 and IL4 could be important biomarkers for estimating the risks of asthma and M. pneumoniae infection in children.

Genetic Polymorphism of CAT C-262 T and Susceptibility to Breast Cancer, a Case-Control Study and Meta-Analysis of the Literatures

Catalase (CAT) activity is likely to be affected by functional polymorphism of C-262 T (rs1001179) in the CAT gene (OMIM: 115500). It is hypothesized that individuals with the lower expressing forms of the CAT polymorphism may be more susceptible to breast cancer. Therefore, the present case-control study and meta-analysis were carried out. The present case-control study consisted of 407 females with breast cancer and a total of 395 healthy female from population matched with patients according to age. Genotypic analysis for the CAT C-262 T polymorphism was determined by PCR. We identified 7 eligible studies, including 10,471 subjects (4,959 patients, and 5,512 healthy controls) in relation to the CAT C-262 T polymorphism and breast cancer risk. Based on the present case-control study, the CT (OR = 0.90, 95% CI: 0.66-1.22, P = 0.484) and TT (OR = 0.68, 95% CI: 0.35-1.30, P = 0.245) genotypes were not associated with breast cancer risk compared to the CC genotype. For meta-analysis including all studies, there was significant heterogeneity between studies. The overall ORs of the breast cancer risk were not associated with the CT (Q-statistic = 14.90, df = 6, P < 0.05; OR = 1.01, 95% CI: 0.92-1.09, P = 0.862) and TT (Q-statistic = 2.57, df = 6, P > 0.05; OR = 1.03, 95% CI: 0.85-1.24, P = 0.770) genotypes. There was no association between C-262 T polymorphism of the CAT and risk of breast cancer.

Factors influencing the levels of exhaled carbon monoxide in asthmatic children

OBJECTIVE

Bronchial asthma is characterised by chronic airway inflammation commonly associated with increased oxidative stress. Exhaled carbon monoxide (eCO) levels could act as markers of both oxidative stress and allergic inflammation. We aimed to study eCO levels in asthmatics and detect the possible factors influencing them.

METHODS

We studied 241 asthmatic children and 75 healthy children. The differences in eCO levels among various asthmatic phenotypes and the correlations between eCO and other measured parameters (spirometric indices, Asthma Control Test score, exhaled nitric oxide, total IgE, blood eosinophils and marker of oxidative damage of proteins) were analysed.

RESULTS

Levels of eCO widely differed according to the selected characteristics of asthma. Asthmatics showed higher eCO concentrations than controls (1.44 ± 0.12 ppm vs. 0.91 ± 0.11 ppm, p < 0.001). Acute exacerbation of asthma was accompanied by a significant increase in eCO compared to the clinically controlled stage (2.17 ± 0.36 ppm vs. 1.33 ± 0.13 ppm, p < 0.001). Atopic, non-atopic asthma and asthma associated with allergic rhinitis (AR) showed elevated levels of eCO. The levels of eCO negatively correlated with the marker of protein oxidation in asthmatics, especially in atopic form and during acute exacerbation.

CONCLUSIONS

In a population of asthmatic children, eCO levels could be considered as a marker of both allergic inflammation and oxidative stress in the airways. Concomitant AR and asthma control were the most important factors affecting the levels of eCO in asthmatic children. However, our results do not support the use of routine eCO in the clinical practice.

Oxidative stress and genetic markers of suboptimal antioxidant defense in the aging brain: a theoretical review

Normal aging involves a gradual breakdown of physiological processes that leads to a decline in cognitive functions and brain integrity, yet the onset and progression of decline are variable among older individuals. While many biological changes may contribute to this degree of variability, oxidative stress is a key mechanism of the aging process that can cause direct damage to cellular architecture within the brain. Oligodendrocytes are at a high risk for oxidative damage due to their role in myelin maintenance and production and limited repair mechanisms, suggesting that white matter may be particularly vulnerable to oxidative activity. Antioxidant defense enzymes within the brain, such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione-S-transferase (GST), are crucial for breaking down the harmful end products of oxidative phosphorylation. Previous studies have revealed that allele variations of polymorphisms that encode these antioxidants are associated with abnormalities in SOD, CAT, GPx, and GST activity in the central nervous system. This review will focus on the role of oxidative stress in the aging brain and the impact of decreased antioxidant defense on brain integrity and cognitive function. Directions for future research investigations of antioxidant defense genes will also be discussed.