Functional effects of NAD(P)H oxidase p22phox C242T mutation in human leukocytes and association with thrombotic cerebral infarction

[Gene polymorphisms of cytochrome B-245 alpha chain (CYBA) and cholesteryl ester transfer protein (CETP) and susceptibility to generalized aggressive periodontitis]

OBJECTIVE

To explore the correlation of cytochrome B-245 alpha chain (CYBA) rs4673 and cholesteryl ester transfer protein (CETP) rs12720922 polymorphisms with the susceptibility of gene-ralized aggressive periodontitis (GAgP).

METHODS

The study was a case-control trial. A total of 372 GAgP patients and 133 periodontally healthy controls were recruited. The CYBA rs4673 and CETP rs12720922 polymorphisms were detected by matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS). Logistic regression models were used to analyze the correlation of CYBA rs4673 and CETP rs12720922 variants with the susceptibility of GAgP. The interaction between the two gene polymorphisms to the susceptibility of GAgP was analyzed by the likelihood ratio test. The interaction model adopted was the multiplication model.

RESULTS

The mean age of GAgP group and control group was (27.5±5.2) years and (28.8±7.1) years respectively. There was significant difference in age between the two groups (P < 0.05). The gender distribution (male/female) was 152/220 and 53/80 respectively, and there was no significant difference between GAgP group and controls (P>0.05). For CYBA rs4673, the frequency of CT/TT genotype in the GAgP group was significantly higher than that in the controls [18.0% (66/366) vs. 10.6% (14/132), P < 0.05]. After adjusting age and gender, the individuals with CT/TT genotype had a higher risk of GAgP (OR=1.86, 95%CI: 1.01-3.45, P < 0.05), compared with CC genotype. There was no statistically significant difference in distributions of the CETP rs12720922 genotypes (GG, AA/AG) between GAgP patients and healthy controls (P>0.05). A significant interaction between CYBA rs4673 and CETP rs12720922 in the susceptibility to GAgP was observed. The GAgP risk of the individuals with CYBA rs4673 CT/TT and CETP rs12720922 GG genotypes was significantly increased (OR=3.25, 95%CI: 1.36-7.75, P < 0.01), compared with those carrying CC and AA/AG genotypes.

CONCLUSION

CYBA rs4673 CT/TT genotype is associated with GAgP susceptibility. There is a significant interaction between CYBA rs4673 CT/TT genotype and CETP rs12720922 GG genotype in the susceptibility of GAgP.

Impact of CYBA genotypes on severity and progression of multiple sclerosis

Background and purpose

The NOX2 enzyme of myeloid cells generates reactive oxygen species (ROS) that have been implicated in the pathology of multiple sclerosis (MS). We aimed to determine the impact of genetic variation within CYBA, which encodes the functional CYBA/p22^phox subunit of NOX2, on MS severity and progression.

Methods

One hundred three MS patients with up to 49 (median = 17) years follow‐up time from first MS diagnosis were genotyped at the single nucleotide polymorphisms rs1049254 and rs4673 within CYBA. Results were matched with disease severity and time to diagnosis of secondary progressive MS (SPMS). NOX2‐mediated formation of ROS was measured by chemiluminescence in blood myeloid cells from healthy donors (n = 55) with defined genotypes at rs1049254 and rs4673.

Results

The rs1049254/G and rs4673/A CYBA alleles were associated with reduced formation of ROS and were thus defined as low‐ROS alleles. Patients carrying low‐ROS alleles showed reduced multiple sclerosis severity score (p = 0.02, N = 103, linear regression) and delayed onset of SPMS (p = 0.02, hazard ratio [HR] = 0.46, n = 100, log‐rank test). In a cohort examined after 2005, patients carrying low‐ROS CYBA alleles showed >20 years longer time to secondary progression (p = 0.003, HR = 0.29, n = 59, log‐rank test).

Conclusions

These results implicate NOX2 in MS, in particular for the development of secondary progressive disease, and point toward NOX2‐reductive therapy aiming to delay secondary progression.

Genetic Influences in Breast Cancer Drug Resistance

Breast cancer is the most common cancer in adult women aged 20 to 50 years. The therapeutic regimens that are commonly recommended to treat breast cancer are human epidermal growth factor receptor 2 (HER2) targeted therapy, endocrine therapy, and systemic chemotherapy. The selection of pharmacotherapy is based on the characteristics of the tumor and its hormone receptor status, specifically, the presence of HER2, progesterone receptors, and estrogen receptors. Breast cancer pharmacotherapy often gives different results in various populations, which may cause therapeutic failure. Different types of congenital drug resistance in individuals can cause this. Genetic polymorphism is a factor in the occurrence of congenital drug resistance. This review explores the relationship between genetic polymorphisms and resistance to breast cancer therapy. It considers studies published from 2010 to 2020 concerning the relationship of genetic polymorphisms and breast cancer therapy. Several gene polymorphisms are found to be related to longer overall survival, worse relapse-free survival, higher pathological complete response, and increased disease-free survival in breast cancer patients. The presence of these gene polymorphisms can be considered in the treatment of breast cancer in order to shape personalized therapy to yield better results.

Possible Susceptibility Genes for Intervention against Chemotherapy-Induced Cardiotoxicity

Recent therapeutic advances have significantly improved the short- and long-term survival rates in patients with heart disease and cancer. Survival in cancer patients may, however, be accompanied by disadvantages, namely, increased rates of cardiovascular events. Chemotherapy-related cardiac dysfunction is an important side effect of anticancer therapy. While advances in cancer treatment have increased patient survival, treatments are associated with cardiovascular complications, including heart failure (HF), arrhythmias, cardiac ischemia, valve disease, pericarditis, and fibrosis of the pericardium and myocardium. The molecular mechanisms of cardiotoxicity caused by cancer treatment have not yet been elucidated, and they may be both varied and complex. By identifying the functional genetic variations responsible for this toxicity, we may be able to improve our understanding of the potential mechanisms and pathways of treatment, paving the way for the development of new therapies to target these toxicities. Data from studies on genetic defects and pharmacological interventions have suggested that many molecules, primarily those regulating oxidative stress, inflammation, autophagy, apoptosis, and metabolism, contribute to the pathogenesis of cardiotoxicity induced by cancer treatment. Here, we review the progress of genetic research in illuminating the molecular mechanisms of cancer treatment-mediated cardiotoxicity and provide insights for the research and development of new therapies to treat or even prevent cardiotoxicity in patients undergoing cancer treatment. The current evidence is not clear about the role of pharmacogenomic screening of susceptible genes. Further studies need to done in chemotherapy-induced cardiotoxicity.

Effect of C242T Polymorphism in the Gene Encoding the NAD(P)H Oxidase p22phox Subunit and Aerobic Fitness Levels on Redox State Biomarkers and DNA Damage Responses to Exhaustive Exercise: A Randomized Trial

NAD(P)H oxidases (NOXs) constitute a principal source of cellular reactive oxygen species (ROS) and contribute to exercise-induced ROS production in the skeletal muscle. Here, we aimed to investigate the effect of single-bout exhaustive exercise on redox state biomarkers and oxidative DNA damage based on the C242T polymorphism in the gene encoding NOXs subunit p22^phox (CYBA) and aerobic fitness levels. We enrolled 220 healthy adults in their 20s (men, n = 110; women, n = 110), who were divided into CC genotype and T allele groups through the analysis of the CYBA C242T polymorphism. Furthermore, maximum oxygen uptake (VO₂max) was evaluated to divide subjects into high fitness (HF; 70th percentile for aerobic fitness) and mid-range fitness (MF; 40-60th percentile for aerobic fitness) groups, with a total of 32 subjects assigned to four groups (eight subjects per group): CC genotype and HF group (CC + HF), CC genotype and MF group (CC + MF), T allele and HF group (T + HF), and T allele and MF group (T + MF). All subjects performed treadmill running exercise at 85% of VO₂max until exhaustion. Plasma lactate, malondialdehyde (MDA), superoxide dismutase (SOD), and lymphocyte DNA damage (tail DNA percentage [TD], tail length [TL], and the tail moment [TM]) were measured in the blood samples obtained immediately before (IBE), immediately after (IAE), and 30 min after exercise (30 MAE). Plasma lactate levels, SOD activities, and lymphocyte DNA damage markers (TD, TL, and TM) were significantly increased at IAE than that at IBE and significantly decreased at 30 MAE (p < 0.05). All groups displayed increased plasma MDA levels at IAE rather than at IBE, with CC + MF being significantly higher than T + HF (p < 0.05); only the CC + HF and T + HF groups exhibited a significant reduction at 30 MAE (p < 0.05). Moreover, TL at IAE was significantly higher in the CC + MF group than in the T + HF group (p < 0.05), and significantly higher in the CC + MF and CC + HF groups than in the T + HF group at 30 MAE (p < 0.05). TM was significantly higher in the T + MF than in the T + HF group at IAE (p < 0.05) and that of CC + MF was significantly higher than CC + HF and T + HF values at IAE and 30 MAE (p < 0.05). These results suggest that single-bout exhaustive exercise could induce peripheral fatigue and the accumulation of temporary redox imbalance and oxidative DNA damage. Moreover, high aerobic fitness levels combined with the T allele may protect against exercise-induced redox imbalance and DNA damage.

Association between p22PHOX gene C242T polymorphism and hypertension in end-stage kidney disease patients

Oxidative stress plays an important role in hypertension associated vascular damage. It is mediated by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation. The C242T polymorphism in the p22PHOX gene encoding essential subunit of NADPH oxidase was associated with CVD, hypertension, and endothelial function. The aim of this study was to assess a potential association of C242T polymorphism with hypertension in end-stage kidney disease (ESKD) patients. DNA samples from 495 patients were genotyped by polymerase chain reaction (PCR) with subsequent cleavage with Rsa I restriction endonuclease. There were no significant differences in genotype and allele distribution between ESKD patients and healthy controls. When patients were stratified into male and female subgroups, there were no differences in the frequency of the T allele (0.35 and 0.34, respectively). Genotype and allele frequencies were also comparable between HY+ and HY- subgroups. We analyzed whether there were any differences between genders in the effect of C242T polymorphism on the presence of hypertension by comparing HY+ males with normotensive males and HY+ females with normotensive females. No difference in polymorphism distribution was found in female subgroup. The significant differences were observed in males. In HY+ subgroup, the frequencies of T allele and TT genotype were higher than in HY- males, with OR 1.91 (1.31-2.8), p = 0.0008 and OR 4.2 (1.67-10.6), p = 0.002, respectively. In conclusion, this is the first study to demonstrate significant association of the p22PHOX gene polymorphism with hypertension in male ESKD patients, with T allele as a risk factor for hypertension.

Oxidative Stress-Related Gene Polymorphisms Are Associated With Hepatitis B Virus-Induced Liver Disease in the Northern Chinese Han Population

Oxidative stress is closely related to the occurrence and development of various diseases such as cancer, diabetes, and cardiovascular and infectious diseases. We identified six critical genetic variants related to oxidative stress, and evaluated their main effects and their interaction effects on hepatitis B virus (HBV)-induced liver diseases. We enrolled 3,128 Han Chinese subjects into five groups: healthy controls, chronic hepatitis B (CHB), liver cirrhosis (LC), hepatocellular carcinoma (HCC), and natural clearance. We then determined the genotypes in each group for CYBA-rs4673, NCF4-rs1883112, NOX4-rs1836882, rs3017887, SOD2-rs4880, and GCLM-rs41303970, and evaluated the association between these variants and HBV-induced liver diseases. Gene-gene interactions were evaluated using generalized multifactor dimensionality reduction, logistic regression, and four-by-two tables. Significant associations were observed between healthy controls and the CIB group (CHB+LC+HCC). The CYBA-rs4673AG genotype was associated with a 1.356 rate of susceptibility of HBV-induced liver disease compared to the wild type GG genotype. The NCF4-rs1883112G allele occurred more frequently in healthy controls than in the CIB group in all three models (dominant, codominant, and recessive). Nox4-rs1836882 TC showed a protective association, being more frequent in healthy controls compared to the wild type TT genotype. GCLM-rs41303970A was associated with HBV-induced liver disease. The overall best model by multifactor dimensionality reduction was a five factor interaction model that had the highest cross validation consistency (10/10) and test accuracy (0.5669), P= 0.001. Oxidative stress-related gene polymorphisms are likely to be associated with HBV-induced liver disease, suggesting that information on these variations is useful for risk assessment of HBV-induced liver disease.

Impact of NADPH oxidase functional polymorphisms in acute myeloid leukemia induction chemotherapy

Efficacy and toxicity of anthracycline treatment in acute myeloid leukemia (AML) is mediated by reactive oxygen species (ROS). NADPH oxidase is the major endogenous source of ROS and a key mediator of oxidative cardiac damage. The impact of NADPH oxidase polymorphisms (CYBA:rs4673, NCF4:rs1883112, RAC2:rs13058338) was evaluated in 225 adult de novo AML patients. Variant alleles of NCF4 and RAC2 were related to higher complete remission (P=0.035, P=0.016), and CYBA homozygous variant showed lower overall survival with recessive model (P=0.045). Anthracycline-induced cardiotoxicity was associated to NCF4 homozygous variant (P=0.012) and CYBA heterozygous genotype (P=0.027). Novel associations were found between variant allele of CYBA and lower lung and gastrointestinal toxicities, and a protective effect in nephrotoxicity and RAC2 homozygous variant. Moreover, RAC2 homozygous variant was related to delayed thrombocytopenia recovery. This study supports the interest of NADPH oxidase polymorphisms regarding efficacy and toxicity of AML induction therapy, in a coherent integrated manner.

Specific point mutations in key redox enzymes are associated with chemoresistance in epithelial ovarian cancer

Oxidative stress plays an important role in the pathophysiology of ovarian cancer. Resistance to chemotherapy presents a significant challenge for ovarian cancer treatment. Specific single nucleotide polymorphisms (SNPs) in key redox enzymes have been associated with ovarian cancer survival and progression. The objective of this study was to determine whether chemotherapy induces point mutations in key redox enzymes that lead to the acquisition of chemoresistance in epithelial ovarian cancer (EOC). Human EOC cell lines and their chemoresistant counterpart were utilized for this study. Specific SNPs in key redox enzymes were analyzed by TaqMan SNP Genotyping. Activities and levels of key redox enzymes were determined by real-time RT-PCR, ELISA and a greiss assay. Point mutations in key redox enzymes were introduced into sensitive EOC cells via the CRISPR/Cas9 system. Cell viability and IC₅₀ for cisplatin were determined by the MTT Cell Proliferation Assay. Data was analyzed with SPSS using Student's two-tailed t-tests and One-way ANOVA followed by Dunnett's or Tukey's post hoc tests, p<0.05. Here, we demonstrate that chemoresistant EOC cells are characterized by a further enhancement in oxidative stress as compared to sensitive counterparts. Additionally, chemoresistant EOC cells manifested specific point mutations, which are associated with altered enzymatic activity, in key redox enzymes that are not detected in sensitive counterparts. Supplementation of an antioxidant was able to successfully sensitize EOC cells to chemotherapeutics. Causality was established by the induction of these point mutations in sensitive EOC cells, which resulted in a significant increase in the level of chemoresistance. These findings indicate that chemotherapy induces specific point mutations in key redox enzymes that contribute to the acquisition of chemoresistance in EOC cells, highlighting a potential novel mechanism. Identification of targets for chemoresistance with either biomarker and/or screening potential will have a significant impact for the treatment of this disease.

RAGE and CYBA polymorphisms are associated with microalbuminuria and end-stage renal disease onset in a cohort of type 1 diabetes mellitus patients over a 20-year follow-up

AIMS

We investigated the association of polymorphisms of three genes implicated in oxidative stress: CYBA C242T, RAGE -374T/A and -429T/C, and ALOX12 Arg261Gln, with the delay of microalbuminuria onset in patients with type 1 diabetes mellitus (DT1).

METHODS

A total of 162 T1D patients presenting with diabetes for 32.9 ± 9 years were included in the study; 53 had persistent microalbuminuria (>30 mg/l) and 109 did not. Onset of diabetes, microalbuminuria and end-stage renal disease (ESRD) were recorded as bio-clinical data. We determined polymorphism association of microalbuminuria with a Cox regression model.

RESULTS

All polymorphisms respected the Hardy-Weinberg equilibrium. The Cox regression model validated four significant variables associated with microalbuminuria: RAGE 374AA (HR 4.19 [1.84-9.58] (p = 0.001)), CYBA TT+TC (HR 2.1 [1.16-3.80], p = 0.015), male sex (HR 1.92 [1.07-3.43], p = 0.028) and diabetes diagnosis at the pediatric stage (HR 1.85 [1.03-3.32], p = 0.039). The same association was found with ESRD (p = 0.028 and p = 0.033 for CYBA TC+TT and RAGE 374AA, respectively). CYBA C242T and RAGE 374T/A were not significantly associated with diabetic retinopathy.

CONCLUSIONS

CYBA C242T and RAGE -374T/A correlate with microalbuminuria onset in the French DT1 cohort. The same correlation with ESRD onset supports the argument for the involvement of a genetic predisposition involving kidney-specific oxidative stress for diabetic nephropathy.

Genetic variants involved in oxidative stress, base excision repair, DNA methylation, and folate metabolism pathways influence myeloid neoplasias susceptibility and prognosis

Myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) share common features: elevated oxidative stress, DNA repair deficiency, and aberrant DNA methylation. We performed a hospital-based case-control study to evaluate the association in variants of genes involved in oxidative stress, folate metabolism, DNA repair, and DNA methylation with susceptibility and prognosis of these malignancies. To that end, 16 SNPs (one per gene: CAT, CYBA, DNMT1, DNMT3A, DNMT3B, GPX1, KEAP1, MPO, MTRR, NEIL1, NFE2F2, OGG1, SLC19A1, SOD1, SOD2, and XRCC1) were genotyped in 191 patients (101 MDS and 90 AML) and 261 controls. We also measured oxidative stress (reactive oxygen species/total antioxidant status ratio), DNA damage (8-hydroxy-2'-deoxyguanosine), and DNA methylation (5-methylcytosine) in 50 subjects (40 MDS and 10 controls). Results showed that five genes (GPX1, NEIL1, NFE2L2, OGG1, and SOD2) were associated with MDS, two (DNMT3B and SLC19A1) with AML, and two (CYBA and DNMT1) with both diseases. We observed a correlation of CYBA TT, GPX1 TT, and SOD2 CC genotypes with increased oxidative stress levels, as well as NEIL1 TT and OGG1 GG genotypes with higher DNA damage. The 5-methylcytosine levels were negatively associated with DNMT1 CC, DNMT3A CC, and MTRR AA genotypes, and positively with DNMT3B CC genotype. Furthermore, DNMT3A, MTRR, NEIL1, and OGG1 variants modulated AML transformation in MDS patients. Additionally, DNMT3A, OGG1, GPX1, and KEAP1 variants influenced survival of MDS and AML patients. Altogether, data suggest that genetic variability influence predisposition and prognosis of MDS and AML patients, as well AML transformation rate in MDS patients. © 2016 Wiley Periodicals, Inc.

Allelic variations in the CYBA gene of NADPH oxidase and risk of kidney complications in patients with type 1 diabetes

Oxidative stress plays a pivotal role in the pathophysiology of diabetic nephropathy, and the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase system is an important source of reactive oxygen species in hyperglycemic conditions in the kidney. Plasma concentration of advanced oxidation protein products (AOPP), a marker of oxidative stress, is increased in patients with diabetic nephropathy. We investigated associations of variants in the CYBA gene, encoding the regulatory subunit p22(phox) of NADPH oxidase, with diabetic nephropathy and plasma AOPP and myeloperoxidase (MPO) concentrations in type 1 diabetic patients. Seven SNPs in the CYBA region were analyzed in 1357 Caucasian subjects with type 1 diabetes from the SURGENE (n=340), GENEDIAB (n=444), and GENESIS (n=573) cohorts. Duration of follow-up was 10, 9, and 6 years, respectively. Cox proportional hazards and logistic regression analyses were used to estimate hazard ratios (HR) or odds ratios (OR) for incidence and prevalence of diabetic nephropathy. The major G-allele of rs9932581 was associated with the incidence of renal events defined as new cases of microalbuminuria or the progression to a more severe stage of nephropathy during follow-up (HR 1.59, 95% CI 1.17-2.18, P=0.003) in SURGENE. The same allele was associated with established/advanced nephropathy (OR 1.52, 95% CI 1.22-1.92, P=0.0001) and with the incidence of end-stage renal disease (ESRD) (HR 2.01, 95% CI 1.30-3.24, P=0.001) in GENEDIAB/GENESIS pooled studies. The risk allele was also associated with higher plasma AOPP concentration in subsets of SURGENE and GENEDIAB, with higher plasma MPO concentration in a subset of GENEDIAB, and with lower estimated glomerular filtration rate (eGFR) in the three cohorts. In conclusion, a functional variant in the promoter of the CYBA gene was associated with lower eGFR and with prevalence and incidence of diabetic nephropathy and ESRD in type 1 diabetic patients. These results are consistent with a role for NADPH oxidase in the pathophysiology of kidney complications of diabetes.

NADPH oxidase p22phox C242T polymorphism and ischemic cerebrovascular disease: an updated meta-analysis

Background

A growing number of studies on the associations between nicotinamide adenine dinucleotide phosphate (NADPH) oxidase p22^phox C242T polymorphism and risk of ischemic cerebrovascular disease have recently been published, but the results remain inconsistent.

Material/Methods

We performed an updated meta-analysis to evaluate this association. Eight case-control studies were included, involving 2045 cases and 2102 controls. Heterogeneity was assessed by the Q test and the I² statistic. Begg and Egger’s tests were conducted to evaluate publication bias. Odds ratio (OR) was tested to identify the associations.

Results

Significant associations between p22^phox gene C242T polymorphism and ischemic cerebrovascular disease (ICVD) risk were observed in the allelic genetic model (OR=1.33, 95% confidence interval [CI] 1.00–1.77, p=0.048). No statistical significant association was found in the dominant model (OR=0.74, 95% CI 0.54–1.02, p=0.064) and recessive model (OR=1.40, 95% CI 0.89–2.19, p=0.146). Subgroup analysis showed an association in European populations for recessive model (OR=2.13, 95% CI 1.06–4.26, p=0.034) and no significant evidence of association in Asian populations was found (dominant model: OR=0.64, 95% CI 0.41–1.00, p=0.05; recessive model: OR=0.98, 95% CI 0.53–1.81, p=0.948; allelic model: OR=1.51, 95% CI 0.98–2.32, p=0.061).

Conclusions

p22^phox gene C242T polymorphism was associated with ICVD risk in the allelic genetic model, as well as in European populations for recessive model. No evidence showed association between p22^phox gene C242T polymorphism and ICVD risk in the dominant model and recessive model. Furthermore, no association existed in Asian populations for any of the 3 genetic models and European populations in the dominant model and allelic model.

Association of NADPH oxidase polymorphisms with anthracycline-induced cardiotoxicity in the RICOVER-60 trial of patients with aggressive CD20(+) B-cell lymphoma

AIM

To identify gene variants responsible for anthracycline-induced cardiotoxicity.

PATIENTS & METHODS

Polymorphisms of the NADPH oxidase subunits and of the anthracycline transporters ABCC1, ABCC2 and SLC28A3 were genotyped in elderly patients (61-80 years) treated for aggressive CD20(+) B-cell lymphomas with CHOP-14 with or without rituximab and followed up for 3 years.

RESULTS

The accumulation of RAC2 subunit genotypes TA/AA among cases was statistically significant upon adjustment for gender, age and doxorubicin dose in a multivariate logistic regression analysis (OR: 2.3, p = 0.028; univariate: OR: 1.8, p = 0.077). RAC2 and CYBA genotypes were significantly associated with anthracycline-induced cardiotoxicity in a meta-analysis of this and a similar previous study.

CONCLUSION

Our results support the theory that NADPH oxidase is involved in anthracycline-induced cardiotoxicity. Original submitted 9 July 2014; Revision submitted 19 December 2014.

Impact of genetic variability and treatment-related factors on outcome in early breast cancer patients receiving (neo-) adjuvant chemotherapy with 5-fluorouracil, epirubicin and cyclophosphamide, and docetaxel

To assess the impact of patient-related factors, including genetic variability in genes involved in the metabolism of chemotherapeutic agents, on breast cancer-specific survival (BCSS) and recurrence-free interval (RFI). We selected early breast cancer patients treated between 2000 and 2010 with 4-6 cycles of (neo-)adjuvant 5-fluorouracil, epirubicin, and cyclophosphamide (FEC) or 3 cycles FEC followed by 3 cycles docetaxel. Tumor stage/subtype; febrile neutropenia and patient-related factors such as selected single nucleotide polymorphisms and baseline laboratory parameters were evaluated. Multivariable Cox regression was performed. Of 991 patients with a mean follow-up of 5.2 years, 152 (15.3 %) patients relapsed and 63 (6.4 %) patients died. Advanced stage and more aggressive subtype were associated with poorer BCSS and RFI in multivariable analysis (p < 0.0001). Associations with worse BCSS in multivariable analysis were: homozygous carriers of the rs1057910 variant C-allele in CYP2C9 (hazard ratio [HR] 30.4; 95 % confidence interval [CI] 6.1-151.5; p < 0.001) and higher white blood cell count (WBC) (HR 1.2; 95 % CI 1.0-1.3; p = 0.014). The GT genotype of the ABCB1 variant rs2032582 was associated with better BCSS (HR 0.5; 95 % CI 0.3-0.9, p = 0.021). Following associations with worse RFI were observed: higher WBC (HR 1.1; 95 % CI 1.0-1.2; p = 0.026), homozygous carriers of the rs1057910 variant C-allele in CYP2C9 (HR 10.9; 95 % CI 2.5-47.9; p = 0.002), CT genotype of the CYBA variant rs4673 (HR 1.8; 95 % CI 1.2-2.7; p = 0.006), and G-allele homozygosity for the UGT2B7 variant rs3924194 (HR 3.4; 95 % CI 1.2-9.7, p = 0.023). Patient-related factors including genetic variability and baseline white blood cell count, impacted on outcome in early breast cancer.

Investigation of association between donors' and recipients' NADPH oxidase p22(phox) C242T polymorphism and acute rejection, delayed graft function and blood pressure in renal allograft recipients

BACKGROUND

Production of reactive oxygen species (ROS) and thereby induction of oxidative stress seem to be one of the major mediators of inflammatory adverse outcomes after renal transplantation. p22(phox) is a polymorphic subunit of NAD(P)H-oxidase that is critical for activation and stabilization of the enzyme. This enzyme is involved in the production of superoxide that triggers inflammatory injuries to the kidney. So in this study, the association between donors and recipients' C242T polymorphism of p22(phox) and acute rejection (AR), delayed graft function (DGF), creatinine clearance (CrCl), and blood pressure in renal-allograft recipients was studied.

METHODS

One hundred ninety six donor-recipient pairs were studied. The C242T polymorphism of p22(phox) was determined using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). According to p22 genotype, the subjects were divided in wild-type (CC) and T allele carriers (CT+TT). Transplantation outcomes were determined using acute rejection and delayed graft function criteria. The mean arterial pressure was also measured monthly after transplantation.

RESULTS

There was a significant association between the recipients' p22(phox) polymorphism and DGF occurrence (OR=2.5, CI: 1.2-4.9, p=0.0009). No significant association was detected between donors' p22(phox) polymorphism and AR and DGF events. CrCl during the six months follow-up after transplantation was lower in the patients who received allograft from donors carrying 242T allele (B=-12.8, CI: -22.9-12.8 (-22.9 to -2.6)). Changes in the blood pressure were not different among the patients having different genotypes of p22(phox).

CONCLUSION

These results suggest that the recipients' p22(phox) C242T polymorphism may be a major risk factor for DGF in renal transplantation. Moreover, the donors' 242T allele seems to affect the rate of CrCl in the renal allograft recipients.

15-Deoxy-∆12,14-PGJ 2, by activating peroxisome proliferator-activated receptor-gamma, suppresses p22phox transcription to protect brain endothelial cells against hypoxia-induced apoptosis

15-Deoxy-∆(12,14)-PGJ(2) (15d-PGJ(2)) and thiazolidinedione attenuate reactive oxygen species (ROS) production via a peroxisome proliferator-activated receptor-gamma (PPAR-γ)-dependent pathway. Nonetheless, how PPAR-γ mediates ROS production to ameliorate ischemic brain injury is not clear. Recent studies indicated that nicotinamide adenine dinucleotide phosphate (NADPH) oxidase is the major source of ROS in the vascular system. In the present study, we used an in vitro oxygen-glucose deprivation and reoxygenation (hypoxia reoxygenation [HR]) paradigm to study whether PPAR-γ interacts with NADPH oxidase, thereby regulating ROS formation in cerebral endothelial cells (CECs). With pharmacological (PPAR-γ antagonist GW9662), loss-of-function (PPAR-γ siRNA), and gain-of-function (Ad-PPAR-γ) approaches, we first demonstrated that 15d-PGJ(2) protected HR-treated CECs against ROS-induced apoptosis in a PPAR-γ-dependent manner. Results of promoter and subcellular localization analyses further revealed that 15d-PGJ(2), by activating PPAR-γ, blocked HR-induced NF-κB nuclear translocation, which led to inhibited transcription of the NADPH oxidase subunit p22phox. In summary, we report a novel transrepression mechanism whereby PPAR-γ downregulates hypoxia-activated p22phox transcription and the subsequent NADPH oxidase activation, ROS formation, and CEC apoptosis.

Influence of the C242T polymorphism of the p22-phox gene (CYBA) on the interaction between urinary sodium excretion and blood pressure in an urban Brazilian population

BACKGROUND

Reactive oxygen species are implicated in the physiopathogenesis of salt-induced hypertension and the C242T polymorphism of the p22-phox gene has been associated with higher superoxide production. This study investigated the impact of this polymorphism on the relationship between urinary sodium excretion (USE) and blood pressure levels in an urban Brazilian population.

METHODS

We cross-sectionally evaluated 1,298 subjects from the city of Vitoria-ES, located in the Southeast region of Brazil, by clinical history, physical examination, anthropometry, analysis of laboratory parameters, USE measurement and p22-phox C242T polymorphism genotyping.

RESULTS

No significant differences in studied parameters were detected between the studied genotype groups (CC vs. CT+TT). Systolic blood pressure exhibited significant correlation with USE only in T allele carriers (r = 0.166; p<0.001), while diastolic blood pressure and hypertension status correlated with USE in both genotypes albeit more weakly in subjects with CC genotype (r = 0.098; p = 0.021 and r = 0.105; p = 0.013, respectively) than in T carriers (r = 0.236; p<0.001 and r = 0.213; p<0.001, respectively). Regression analyses adjusted for confounding factors showed that USE remained independently associated with systolic (p<0.001) and diastolic blood pressure (p<0.001) and hypertension status (p = 0.004) only in T allele carriers. Finally, higher diastolic and systolic blood pressure levels were detected in T allele carriers than in CC genotype individuals in the highest tertile of USE.

CONCLUSIONS

The p22-phox 242T allele is associated with higher blood pressure levels among subjects with higher USE in an urban Brazilian population.

Plasma high sensitivity troponin T levels in adult survivors of childhood leukaemias: determinants and associations with cardiac function

Background

We sought to quantify plasma high sensitivity cardiac troponin (hs-cTnT) levels, their determinants, and their associations with left ventricular (LV) myocardial deformation in adult survivors of childhood acute leukaemias.

Methods and Results

One hundred adult survivors (57 males) of childhood acute leukaemias, aged 24.1±4.2 years, and 42 age-matched controls (26 males) were studied. Plasma cTnT was determined using a highly sensitive assay. Genotyping of NAD(P)H oxidase and multidrug resistance protein polymorphisms was performed. Left ventricular function was assessed by conventional, three-dimensional, and speckle tracking echocardiography. The medians (interquartile range) of hs-cTnT in male and female survivors were 4.9 (4.2 to 7.2) ng/L and 1.0 (1.0 to 3.5) ng/L, respectively. Nineteen survivors (13 males, 6 females) (19%) had elevated hs-cTnT (>95^th centile of controls). Compared to those without elevated hs-TnT levels, these subjects had received larger cumulative anthracycline dose and were more likely to have leukaemic relapse, stem cell transplant, and cardiac irradiation. Their LV systolic and early diastolic myocardial velocities, isovolumic acceleration, and systolic longitudinal strain rate were significantly lower. Survivors having CT/TT at CYBA rs4673 had higher hs-cTnT levels than those with CC genotype. Functionally, increased hs-cTnT levels were associated with worse LV longitudinal systolic strain and systolic and diastolic strain rates.

Conclusions

Increased hs-cTnT levels occur in a significant proportion of adult survivors of childhood acute leukaemias and are associated with larger cumulative anthracycline dose received, history of leukaemic relapse, stem cell transplant, and cardiac irradiation, genetic variants in free radical metabolism, and worse LV myocardial deformation.

Genotype-phenotype interactions in pediatric obstructive sleep apnea

Pediatric sleep disordered breathing (PSDB) is not only a very frequent condition affecting 2-4% of all children, but is also associated with an increased risk for a variety of manifestations underlying end-organ injury and dysfunction that impose both immediate and potentially long-term morbidities and corresponding inherent elevations in healthcare costs. One of the major problems with the creation of valid algorithms aiming to stratify diagnostic and treatment prioritization lies in our current inability to predict and identify those children who are most at-risk for PSDB-induced adverse consequences. Thus, improved our understanding of the mechanisms governing phenotype variance in PSDB is essential. Here, we examine some of the potential underpinnings of phenotypic variability in PSDB, and further propose a conceptual framework aimed at facilitating the process of advancing knowledge in this frequent disorder.

Association between NADPH oxidase p22(phox) C242T polymorphism and ischemic cerebrovascular disease: a meta-analysis

Background

Epidemiological studies have evaluated the association between nicotinamide adenine dinucleotide phosphate (NADPH) oxidase p22^phox C242T polymorphism and risk of ischemic cerebrovascular disease (ICVD), but the results remain inconclusive. This meta-analysis was therefore designed to clarify these controversies.

Methodology/Principal Findings

Systematic searches of electronic databases Embase, PubMed and Web of Science, as well as hand searching of the references of identified articles and the meeting abstracts were performed. Statistical analyses were performed using software Review Manager (Version 5.1.7) and Stata (Version 11.0). The pooled odds ratios (ORs) with 95% confidence intervals (95%CIs) were performed. Fixed or random effects model was separately used depending on the heterogeneity between studies. Publication bias was tested by Begg's funnel plot and Egger's regression test. A total of 6 studies including 1,948 cases and 2,357 controls were combined showing no statistical evidence of association between NADPH oxidase p22^phox C242T polymorphism and overall ICVD (allelic model: OR = 1.08, 95%CI = 0.93–1.26; additive model: OR = 1.33, 95%CI = 0.81–2.17; dominant model: OR = 1.00, 95%CI = 0.86–1.15; recessive model: OR = 1.06, 95%CI = 0.77–1.45). Significant association was found in large-artery atherosclerotic stroke subgroup (allelic model: OR = 1.12, 95%CI = 0.88–1.41; additive model: OR = 1.36, 95%CI = 0.60–3.09; dominant model: OR = 1.25, 95%CI = 0.74–2.11; recessive model: OR = 2.17, 95%CI = 1.11–4.23). No statistical evidence of significant association was observed for small-vessel occlusive stroke, as well as Asian subgroup and Caucasian subgroup. Statistical powers on the combined sample size (total and subgroup) were all lower than 80%.

Conclusions/Significance

This meta-analysis indicates that NADPH oxidase p22^phox C242T polymorphism is more associated with large-artery atherosclerotic stroke than small-vessel occlusive stroke. However, this conclusion should be interpreted with caution due to the small sample size. Larger sample-size studies with homogeneous ICVD patients and well-matched controls are required.

CYBA C242T polymorphism is associated with obesity and diabetes mellitus in Brazilian hypertensive patients

AIMS

The CYBA C242T polymorphism has been associated with cardiovascular phenotypes such as hypertension and atherosclerosis, but available data are conflicting. This report investigated the impact of this variant on hypertension and metabolic determinants of cardiovascular risk in a large Brazilian sample.

METHODS

We cross-sectionally evaluated 1856 subjects (826 normotensive subjects and 1030 hypertensive patients) by clinical history, anthropometry, laboratory analysis and genotyping of the CYBA C242T polymorphism.

RESULTS

Genotype frequencies in the whole population were consistent with the Hardy-Weinberg equilibrium and genotype distributions were not different between hypertensive and normotensive subjects. Hypertensive patients with the CC genotype presented lower fasting plasma glucose levels (5.9 ± 0.1 vs. 6.2 ± 0.1 mmol/l, P = 0.020) and waist circumference (94.5 ± 0.6 vs. 96.3 ± 0.6 cm, P = 0.028) than CT + TT ones. Similarly, the prevalence of diabetes mellitus and obesity was also lower in hypertensive patients carrying the CC genotype (16% vs. 21%, P = 0.041; 36% vs. 43%, P = 0.029, respectively). In addition, multiple and logistic regression analysis demonstrated that the CYBA C242T polymorphism was associated with glucose levels, waist circumference, obesity and diabetes mellitus in hypertensive patients independently of potential confounders. Conversely, in normotensive subjects, no significant difference in studied variables was detected between the genotype groups.

CONCLUSIONS

These data suggest that the T allele of the CYBA C242T polymorphism may be used as a marker for adverse metabolic features in Brazilian subjects with systemic hypertension.

Association between the C242T polymorphism in the p22phox gene with arterial stiffness in the Brazilian population

NADPH oxidase p22phox subunit is responsible for the production of reactive oxygen species in the vascular tissue. The C242T polymorphism in the p22phox gene has been associated with diverse coronary artery disease phenotypes, but the findings about the protective or harmful effects of the T allele are still controversial. Our main aim was to assess the effect of p22phox C242T genotypes on arterial stiffness, a predictor of late morbidity and mortality, in individuals from the general population. We randomly selected 1,178 individuals from the general population of Vitoria City, Brazil. Genotypes for the C242T polymorphism were detected by PCR-RFLP, and pulse wave velocity (PWV) values were measured with a noninvasive automatic device Complior. p22phox and TNF-α gene expression were quantified by real-time PCR in human arterial mammary smooth muscle cells. In both the entire and nonhypertensive groups: individuals carrying the TT genotype had higher PWV values and higher risk for increased arterial stiffness [odds ratio (OR) 1.93, 95% confidence interval (CI) 1.27-2.92 and OR 1.78, 95% CI 1.07-2.95, respectively] compared with individuals carrying CC+CT genotypes, even after adjustment for covariates. No difference in the p22phox gene expression according C242T genotypes was observed. However, TNF-α gene expression was higher in cells from individual carrying the T allele, suggesting that this genetic marker is associated with functional phenotypes at the gene expression level. In conclusion, we suggest that p22phox C242T polymorphism is associated with arterial stiffness evaluated by PWV in the general population. This genetic association shed light on the understanding of the genetic modulation on vascular dysfunction mediated by NADPH oxidase.

The C242T polymorphism of the p22-phox gene (CYBA) is associated with higher left ventricular mass in Brazilian hypertensive patients

BACKGROUND

Reactive oxygen species have been implicated in the physiopathogenesis of hypertensive end-organ damage. This study investigated the impact of the C242T polymorphism of the p22-phox gene (CYBA) on left ventricular structure in Brazilian hypertensive subjects.

METHODS

We cross-sectionally evaluated 561 patients from 2 independent centers [Campinas (n = 441) and Vitória (n = 120)] by clinical history, physical examination, anthropometry, analysis of metabolic and echocardiography parameters as well as p22-phox C242T polymorphism genotyping. In addition, NADPH-oxidase activity was quantified in peripheral mononuclear cells from a subgroup of Campinas sample.

RESULTS

Genotype frequencies in both samples were consistent with the Hardy- Weinberg equilibrium. Subjects with the T allele presented higher left ventricular mass/height2.7 than those carrying the CC genotype in Campinas (76.8 ± 1.6 vs 70.9 ± 1.4 g/m2.7; p = 0.009), and in Vitória (45.6 ± 1.9 vs 39.9 ± 1.4 g/m2.7; p = 0.023) samples. These results were confirmed by stepwise regression analyses adjusted for age, gender, blood pressure, metabolic variables and use of anti-hypertensive medications. In addition, increased NADPH-oxidase activity was detected in peripheral mononuclear cells from T allele carriers compared with CC genotype carriers (p = 0.03).

CONCLUSIONS

The T allele of the p22-phox C242T polymorphism is associated with higher left ventricular mass/height 2.7 and increased NADPH-oxidase activity in Brazilian hypertensive patients. These data suggest that genetic variation within NADPH-oxidase components may modulate left ventricular remodeling in subjects with systemic hypertension.

The C242T polymorphism of the gene encoding cytochrome b-245 alpha is not associated with paediatric ischaemic stroke: family-based and case-control study

BACKGROUND AND PURPOSE

Reactive oxygen species play an important role in the physiology and pathology of cerebral arteries, including ischaemic stroke. The cytochrome b-245 alpha gene (CYBA) encodes cytochrome b-245 alpha light chain (p22phox peptide), a critical element of NAD(P)H oxidases, the most important source of superoxide anion in the cerebral arteries. To search for genetic factors associated with paediatric ischaemic stroke, the possible association between CYBA gene C242T polymorphism and the disease was evaluated.

MATERIAL AND METHODS

The study group consisted of 238 individuals: children with ischaemic stroke (n = 70), their biological parents (n = 118) and children without any symptoms of stroke (n = 50). The C242T polymorphism was genotyped using polymerase chain reaction - restriction fragment length methodology. To evaluate the possible association between polymorphism and stroke, the transmission disequilibrium test and the case-control method were applied.

RESULTS

The C242 allele was transmitted more frequently than 242T (62.2% vs. 37.8%) but observed frequencies did not differ significantly from expected (p = 0.10). There were also no significant differences in allele and genotype distribution between patients and control subjects (patients: CC - 50.0%, CT - 38.6%, TT - 11.4% vs. controls: CC - 52.0%, CT - 36.0%, TT - 12.0%).

CONCLUSIONS

The study did not show that the C242T polymorphism of the CYBA gene is a risk factor of ischaemic stroke in children.

Leukocyte nicotinamide adenine dinucleotide phosphate-reduced oxidase is required for isocyanate-induced lung inflammation

BACKGROUND

Isocyanates are low-molecular-weight compounds noted for inducing occupational and environmental asthma. Isocyanate-induced lung disease, an oxidant stress-dependent pulmonary inflammation, is the leading cause of occupational asthma.

OBJECTIVES

To address the role of leukocyte-produced oxidants in airway inflammation induced by toluene diisocyanate (TDI), and to elucidate the role of leukocyte nicotinamide adenine dinucleotide phosphate-reduced (NADPH) oxidase in pathogenesis by TDI.

METHODS

Wild-type mice and NADPH oxidase-deficient mice (neutrophil cytosolic factor 1 mutant, Ncf1(-/-)) were intranasally injected, challenged with inhalatory TDI, and then investigated for lung inflammation.

RESULTS

Cell infiltration in lung tissue and leukocytes in bronchoalveolar lavage, airway reactivity to a methacholine challenge, and TDI-induced inflammatory cytokine expression and nuclear factor activation in the lung tissue were all markedly lower in Ncf1(-/-) mice. Wild-type mice treated with blocking antibodies against CD4 and IL-17 showed markedly lower TDI-induced airway hyperresponsiveness.

CONCLUSION

Leukocyte NADPH oxidase is an essential regulator in TDI-induced airway inflammation through redox modification of immune responses.

NOX enzymes in the central nervous system: from signaling to disease

Oxidative stress has been implicated in the pathogenesis of neurologic and psychiatric diseases. The brain is particularly vulnerable to oxidative damage due to high oxygen consumption, low antioxidant defense, and an abundance of oxidation-sensitive lipids. Production of reactive oxygen species (ROS) by mitochondria is generally thought to be the main cause of oxidative stress. However, a role for ROS-generating NADPH oxidase NOX enzymes has recently emerged. Activation of the phagocyte NADPH oxidase NOX2 has been studied mainly in microglia, where it plays a role in inflammation, but may also contribute to neuronal death in pathologic conditions. However, NOX-dependent ROS production can be due to the expression of other NOX isoforms, which are detected not only in microglia, but also in astrocytes and neurons. The physiologic and pathophysiologic roles of such NOX enzymes are only partially understood. In this review, we summarize the present knowledge about NOX enzymes in the central nervous system and their involvement in neurologic and psychiatric diseases.

The 242T variant of the CYBA gene polymorphism increases the risk of coronary artery disease associated with cigarette smoking and hypercholesterolemia

OBJECTIVES

Hypercholesterolemia and cigarette smoking increase superoxide anion production, which is involved in many proatherosclerotic processes. NAD(P)H oxidases are the main source of superoxides in the vasculature, and the phagocyte oxidase (p22phox) encoded by the CYBA gene is a critical component of NAD(P)H oxidases. The 242T CYBA allele is associated with an increased low-density lipoprotein oxidation and superoxide production. This report focuses on the interactions between C242T CYBA polymorphism and traditional risk factors of coronary artery disease (CAD), such as cigarette smoking and hypercholesterolemia.

METHODS

We have studied 341 individuals, including 172 patients with angiographically confirmed CAD and 169 blood donors with no known history of cardiovascular disease. The C242T CYBA polymorphism was genotyped using the PCR-restriction fragment-length polymorphism method. To determine the possible interactions between CYBA genotypes and the traditional risk factors for CAD, we used multivariate logistic regression analysis (cumulative effects) and the 4 x 2 table approach (synergistic/antagonistic effects).

RESULTS

We have found a strong cumulative effect of the 242T allele carrier state and cigarette smoking and hypercholesterolemia. The risk of CAD associated with the presence of cigarette smoking and hypercholesterolemia was stronger in 242T carriers (odds ratio=17.88, P<0.00000) than in CC homozygotes (odds ratio=3.75, P<0.00000). Estimated CAD risk associated with the presence of the 242T allele and both traditional risk factors was approximately 500% greater than the risk predicted by assuming additivity of effects (synergy index, 5.08).

CONCLUSION

The 242T allele interacts with cigarette smoking and hypercholesterolemia to increase the risk of CAD; this risk is probably associated with the cumulative/synergistic effect of the 242T allele and both the traditional risk factors.

NAD(P)H oxidase p22phoxC242T polymorphism and ischemic stroke in Japan: the Fukuoka Stroke Registry and the Hisayama study

The C242T polymorphism of p22phox, a component of NAD(P)H oxidase, may have an impact on cardiovascular diseases; however, the association between this polymorphism and brain infarction is not fully understood. Here, we investigate the relationship between the C242T polymorphism and brain infarction in Japan. We recruited 1055 patients with brain infarction and 1055 control subjects. A chi-squared test revealed that the T-allele frequency was lower in patients with cardioembolic infarction (5.6%) than in control subjects (11.0%, P < 0.001); however, allele frequencies in patients with lacunar and atherothrombotic infarction (11.2%) were not significantly different from those in control subjects (11.0%). A multivariate-adjusted conditional logistic regression analysis also revealed no association between CT + TT genotype, and lacunar and atherothrombotic infarction (odds ratio = 0.97, 95% confidence interval: 0.72-1.32). To investigate the functional effects of the C242T polymorphism, we examined superoxide production in COS-7 cells cotransfected with Nox4 and p22phox of each genotype. The superoxide-producing activity in those cells expressing p22phox with the T allele was not significantly different from that in cells expressing p22phox with the C allele. The present results suggest that the p22phox C242T polymorphism may have a protective effect against cardioembolic infarction, but is not related to lacunar and atherothrombotic infarction in Japan.

Genetic polymorphisms of NAD(P)H oxidase: variation in subunit expression and enzyme activity

Genetic polymorphisms in superoxide-producing NAD(P)H oxidase have been linked to cardiovascular diseases including anthracycline-induced cardiotoxicity. We quantified NAD(P)H oxidase activity in granulocytes of 81 healthy Caucasian volunteers (in addition, 51 in an independent confirmatory study) by chemiluminescence using the luminol analogue L-012. Expression of CYBA, NCF4 and RAC2 coding for NAD(P)H oxidase subunits was measured in whole blood cells in 59 study participants by real-time PCR. Of the five variants investigated (-930A>G, 242C>T, 640A>G in CYBA and the recently reported -368G>A in NCF4 and 7508T>A in RAC2), only CYBA 640A>G was consistently associated with superoxide production (640GG carriers 28% less than AA individuals, P=0.05 in each cohort, P=0.005 in combined analysis). RAC2 7508T>A was related to higher expression of RAC2 (P=0.02) and NCF4 (P=0.04). In summary, CYBA 640A>G rather than 242C>T was associated with reduced activity. The quantitatively moderate effect and the high intra-individual variability should be considered for further study design.

Associations of polymorphism of P22(phox) C242T, plasma levels of vitamin E, and smoking with coronary heart disease in China

BACKGROUND

The C242T polymorphisms of P22(phox) and plasma vitamin E have been associated with the risk of coronary heart disease (CHD) in several studies, but the results have been inconsistent. In this study, we sought to examine potential interactions between P22(phox) genotypes, plasma vitamin E concentrations, and smoking in relation to CHD risk.

METHODS

We determined C242T genotype frequency in the P22(phox) gene and plasma levels of vitamin E in 565 Chinese patients with CHD and 609 control subjects. Logistic regression was used to control for potential confounders in multivariate analyses.

RESULTS

Compared with subjects with a CC genotype, subjects with a CT or TT genotype had a lower risk of CHD (multivariate-adjusted odds ratio [OR] 0.45, 95% CI 0.28-0.74, P = .001). Plasma concentrations of vitamin E were lower in case patients than in control subjects (multivariate-adjusted OR 0.65, 95% CI 0.50-0.86, P = .025). Compared with nonsmokers with a CC genotype, nonsmokers with a CT or TT genotype had a decreased risk of CHD (OR 0.25, 95% CI 0.12-0.53), but smokers with a CT or TT genotype had an increased risk (OR 2.04, 95% CI 0.74-5.61, P for interaction = .039). Smokers with a lower vitamin E concentration had a >3.0-fold greater risk of CHD than did nonsmokers with a higher vitamin E concentration (OR 3.52, 95% CI 2.36-5.24, P for interaction = .041).

CONCLUSIONS

These data provide evidence that P22(phox) genotypes are significantly associated with CHD risk in a Chinese population and suggest potential interactions among smoking, P22(phox) genotypes, and vitamin E in relation to CHD risk.

The NOX family of ROS-generating NADPH oxidases: physiology and pathophysiology

For a long time, superoxide generation by an NADPH oxidase was considered as an oddity only found in professional phagocytes. Over the last years, six homologs of the cytochrome subunit of the phagocyte NADPH oxidase were found: NOX1, NOX3, NOX4, NOX5, DUOX1, and DUOX2. Together with the phagocyte NADPH oxidase itself (NOX2/gp91(phox)), the homologs are now referred to as the NOX family of NADPH oxidases. These enzymes share the capacity to transport electrons across the plasma membrane and to generate superoxide and other downstream reactive oxygen species (ROS). Activation mechanisms and tissue distribution of the different members of the family are markedly different. The physiological functions of NOX family enzymes include host defense, posttranlational processing of proteins, cellular signaling, regulation of gene expression, and cell differentiation. NOX enzymes also contribute to a wide range of pathological processes. NOX deficiency may lead to immunosuppresion, lack of otoconogenesis, or hypothyroidism. Increased NOX activity also contributes to a large number or pathologies, in particular cardiovascular diseases and neurodegeneration. This review summarizes the current state of knowledge of the functions of NOX enzymes in physiology and pathology.

Impact of NAD(P)H oxidase p22 phox gene polymorphism on vascular aging in Korean centenarian and nonagenarian

BACKGROUND

Oxidative stress, the imbalance between production and removal of reactive oxygen species (ROS), is implicated in the process of cardiovascular aging. Membrane-associated NAD(P)H oxidase system is the most important source of ROS in vascular cells. p22(phox), a critical component of the NAD(P)H oxidase, has a polymorphic site on exon 4, associated with variable enzyme activity. The goal of this study is to investigate the effect of the p22(phox) C242T polymorphism on cardiovascular aging.

METHODS

We investigated, in a cross-sectional study, the distribution of the p22(phox) genotypes and its impact on vascular aging in elderly Korean subjects (N=123, mean age+/-SD: 97.0+/-5.0). p22(phox) C242T polymorphism was determined by PCR and restriction fragment length polymorphism analysis. The p22(phox) genotype and allele frequencies were also compared with younger Korean subjects (N=363, mean age+/-SD: 49.0+/-10.3).

RESULTS

No significant difference was identified in p22(phox) genotype frequency according to the subject's age. However, the prevalence of CT+TT genotype was significantly less frequent in normotensive extremely elderly compared with younger subjects. Furthermore, the prevalence of the CT+TT genotype was significantly more frequent in hypertensive subjects (21.9%) than in the normotensive group (6.0%, P=0.016) in extremely elderly subject. The association was more significant in systolic hypertension rather than diastolic hypertension. Mean systolic blood pressure and pulse pressure were also significantly higher in subjects with CT+TT genotype. In contrast, there was no significant association between p22(phox) genotype and hypertension in younger-aged group.

CONCLUSION

These results suggest an association between the p22(phox) C242T polymorphism and vascular aging, which might be mediated by the increase of oxidative stress.

Association of gene polymorphism with genetic susceptibility to stroke in Asian populations: a meta-analysis

Stroke is a heterogeneous multifactorial disease and is thought to have a polygenic basis. Case-control studies on gene sequence variations have identified a number of potential genetic predisposition factors, but due to the conflicting results, uncertainty remains on the effect of these polymorphisms on risk for the development of stroke. To qualitatively and quantitatively assess the risk associated with different gene polymorphisms for stroke in Asian populations, we comprehensively searched and identified all the studies of association. Clinically overt case-control studies were selected only if neuroimaging had been used as the confirmatory measure for diagnosis of stroke. We performed a meta-analysis of the three most investigated genes, viz., methylenetetrahydrofolate reductase (MTHFR), apolipoprotein E (ApoE) and angiotensin-converting enzyme (ACE). Statistically significant association with stroke were identified for C677T polymorphism of MTHFR [random effects odds ratio (OR) = 1.47, 95% confidence interval (95% CI) 1.19, 1.82; P = 0.0004] and marginally significant association was detected with allele epsilon 4 of ApoE (random effects OR = 1.47, 95% CI 1.00, 2.15; P = 0.049). The sensitivity analysis (exclusion of studies with controls not in Hardy-Weinberg equilibrium) revealed a significant association of stroke with the MTHFR C677T and ApoE epsilon 4 alleles but showed no association with ACE gene insertion/deletion polymorphism.

Genetic polymorphisms in the oxidative stress pathway and susceptibility to non-Hodgkin lymphoma

Oxidative damage caused by reactive oxygen species (ROS) and other free radicals is involved in a number of pathological conditions including cancer. In a population-based case-control study of non-Hodgkin lymphoma (NHL) (n = 518 cases, 597 controls) among women in Connecticut, we analyzed one or more single nucleotide polymorphisms (SNPs) in ten candidate genes (AKR1A1, AKR1C1, AKR1C3, CYBA, GPX1, MPO, NOS2A, NOS3, OGG1, and SOD2) that mediate oxidative stress directly or indirectly in the NADPH oxidase-dependent respiratory burst. Odds ratios (OR) and 95% confidence intervals (CI) were adjusted for age and race. Polymorphisms in AKR1A1 and CYBA were significantly associated with increased risk of NHL. There was a 1.7-fold (95% CI = 1.2-2.4, P = 0.0047) increased risk of NHL for individuals who were variant homozygous for the AKR1A1 (IVS5 + 282T > C) SNP. The effect was most pronounced for risk of diffuse large B-cell lymphoma, but risk estimates were non-significantly elevated for other common B-cell histologies and T-cell lymphomas as well. In addition, individuals variant homozygous for the CYBA (Ex4 + 11C > T) SNP had a 1.6-fold (95% CI = 1.1-2.4, P = 0.019) increased risk of NHL that was particularly pronounced for T-cell lymphoma (OR = 3.5, 95% CI = 1.3-9.6, P = 0.013), but was also associated with non-significant increased risks for each of the common B-cell histologies. These results suggest that SNPs in genes related to the oxidative stress pathway may be associated with increased risk of NHL.

NADPH oxidase (CYBA) and FcgammaR polymorphisms as risk factors for aggressive periodontitis: a case-control association study

INTRODUCTION

Neutrophils (PMN) in aggressive periodontitis (AgP) patients have been reported to be hyperactive especially with regards to superoxide production. Polymorphisms in genes influencing PMN function have been proposed as candidate risk factors for AgP. The aim of this study was to test the association of specific gene polymorphisms affecting PMN functions with AgP.

MATERIALS AND METHODS

Two hundred and twenty-four patients with confirmed diagnosis of AgP and 231 subjects with healthy periodontium took part in the study. A blood sample was collected from subjects and genotypes for p22phox (CYBA) NADPH oxidase, FP, Fcalpha and Fcgamma receptors were analysed in a blind fashion.

RESULTS

The C242T p22phox NADPH oxidase T allele was significantly associated with AgP in a multiple logistic regression model adjusting for confounders, and this was observed for all subjects [p = 0.002, odds ratio (OR) = 1.87, 95% confidence interval (CI) = 1.27-2.83] and Caucasians (p = 0.009, OR=2.07, 95% CI = 1.20-3.59). Concomitant presence of C242T p22phox NADPH oxidase T allele and FcgammaRIIIb NA1 homozygosity was associated with the generalized AgP phenotype in Caucasians (p = 0.001, OR = 30.35, 95% CI = 3.81-241.97).

CONCLUSIONS

C242T p22phox NADPH oxidase and FcgammaR polymorphisms may predispose to AgP through a modulation of neutrophil superoxide production.

The C242T CYBA polymorphism of NADPH oxidase is associated with essential hypertension

OBJECTIVE

Oxidative stress is implicated in hypertension. The reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidases are the main source of superoxide in phagocytic and vascular cells. The C242T polymorphism of CYBA, the human gene that encodes p22phox, has been found to be functionally associated with vascular NADPH oxidase activity in atherosclerotic patients. We investigated the association of the C242T polymorphism with hypertension and its potential impact on NADPH oxidase activity. We also analysed the interaction of C242T polymorphism with the -930A/G CYBA variant.

DESIGN

Case-control study in a random sample of 623 subjects (326 hypertensive patients and 297 normotensive controls) from the general population.

METHODS

CYBA polymorphisms were determined by restriction fragment length polymorphism (RFLP) or allelic discrimination. NADPH oxidase activity and p22phox expression were quantified in phagocytic cells by chemiluminescence and by northern and western blots, respectively.

RESULTS

The prevalence of the CC genotype and the C allele frequency were significantly higher (P < 0.05) in hypertensives than in normotensives. CC genotype remained associated with hypertension after adjusting for potential confounders in a logistic regression analysis. Increased phagocytic NADPH oxidase activity was observed in CC hypertensives compared with CT and TT hypertensives (P < 0.05). Enhanced plasma levels of von Willebrand factor were found in CC hypertensives compared with TT hypertensives (P < 0.05). The C242T polymorphism was not in linkage disequilibrium with the -930A/G CYBA promoter variation, which also associates with hypertension.

CONCLUSION

The C242T CYBA polymorphism is associated with essential hypertension. Furthermore, hypertensives carrying the CC genotype of this polymorphism exhibit features of NADPH oxidase-mediated oxidative stress and endothelial damage.

Genetic polymorphisms and susceptibility to lung disease

Susceptibility to infection by bacterium such as Bacillus anthracis has a genetic basis in mice and may also have a genetic basis in humans. In the limited human cases of inhalation anthrax, studies suggest that not all individuals exposed to anthrax spores were infected, but rather, individuals with underlying lung disease, particularly asthma, sarcoidosis and tuberculosis, might be more susceptible. In this study, we determined if polymorphisms in genes important in innate immunity are associated with increased susceptibility to infectious and non-infectious lung diseases, particularly tuberculosis and sarcoidosis, respectively, and therefore might be a risk factor for inhalation anthrax. Examination of 45 non-synonymous polymorphisms in ten genes: p47phox (NCF1), p67phox (NCF2), p40phox (NCF4), p22phox (CYBA), gp91phox (CYBB), DUOX1, DUOX2, TLR2, TLR9 and alpha 1-antitrypsin (AAT) in a cohort of 95 lung disease individuals and 95 control individuals did not show an association of these polymorphisms with increased susceptibility to lung disease.

NAD(P)H oxidase and multidrug resistance protein genetic polymorphisms are associated with doxorubicin-induced cardiotoxicity

BACKGROUND

A significant number of patients treated with anthracyclines develop cardiotoxicity (anthracycline-induced cardiotoxicity [ACT]), mainly presenting as arrhythmias (acute ACT) or congestive heart failure (chronic ACT). There are no data on pharmacogenomic predictors of ACT.

METHODS AND RESULTS

We genotyped participants of the German non-Hodgkin lymphoma study (NHL-B) who were followed up for the development of heart failure for a median of >3 years. Single-nucleotide polymorphisms (SNPs) were selected from 82 genes with conceivable relevance to ACT. Of 1697 patients, 55 developed acute and 54 developed chronic ACT (cumulative incidence of either form, 3.2%). We detected 5 significant associations with polymorphisms of the NAD(P)H oxidase and doxorubicin efflux transporters. Chronic ACT was associated with a variant of the NAD(P)H oxidase subunit NCF4 (rs1883112, -212A-->G; symbols with right-pointing arrows, as edited?' odds ratio [OR], 2.5; 95% CI, 1.3 to 5.0). Acute ACT was associated with the His72Tyr polymorphism in the p22phox subunit (rs4673; OR, 2.0; 95% CI, 1.0 to 3.9) and with the variant 7508T-->A (rs13058338; OR, 2.6; 95% CI, 1.3 to 5.1) of the RAC2 subunit of the same enzyme. In agreement with these results, mice deficient in NAD(P)H oxidase activity, unlike wild-type mice, were resistant to chronic doxorubicin treatment. In addition, acute ACT was associated with the Gly671Val variant of the doxorubicin efflux transporter multidrug resistance protein 1 (MRP1) (OR, 3.6; 95% CI, 1.6 to 8.4) and with the Val1188Glu-Cys1515Tyr (rs8187694-rs8187710) haplotype of the functionally similar MRP2 (OR, 2.3; 95% CI, 1.0 to 5.4). Polymorphisms in adrenergic receptors previously demonstrated to be predictive of heart failure were not associated with ACT.

CONCLUSIONS

Genetic variants in doxorubicin transport and free radical metabolism may modulate the individual risk to develop ACT.

A beneficial effect of simvastatin on DNA damage in 242T allele of the NADPH oxidase p22phox in hypercholesterolemic patients

BACKGROUND

The effect of simvastatin on DNA damage in hypercholesterolemic patients was investigated, and the relationship between the C242T polymorphism of the NADPH oxidase p22phox gene and the antioxidant effects of simvastatin was examined.

METHODS

Simvastatin (20-40 mg /day) was administered for 8 weeks in 72 hypercholesterolemic patients. DNA damage in lymphocytes was quantified using single-cell gel electrophoresis (COMET assay) by measuring tail DNA (%), tail length (microm) and tail moment (tail length x % tail DNA/100).

RESULTS

Simvastatin significantly reduced DNA damage as expressed by tail DNA (%, p< 0.001), tail length (mum, p<0.001) and tail moment on the DNA in lymphocytes (p<0.001) after 8 weeks. The frequencies of the C242T genotypes for CC, TC, and TT were 75.0%, 23.6% and 1.4% in the subjects. In the presence of the 242T allele, there were higher levels of baseline DNA damage and also a greater improvement in the DNA damage after 8 week simvastatin treatment compared with the CC homozygotes.

CONCLUSION

Simvastatin significantly reduced DNA damage of hypercholesterolemic patients. This study showed that simvastatin has a beneficial effect on the improvement of DNA damage in patients with the 242T allele of NADPH oxidase p22phox gene.