The manganese superoxide dismutase Ala16Val dimorphism modulates both mitochondrial import and mRNA stability

Impact of single nucleotide polymorphisms (SNPs) in antioxidant-enzyme genes on the concentrations of folate, homocysteine and glutathione in plasma from healthy subjects after folic acid supplementation - a randomized controlled crossover trial

BACKGROUND

One-carbon metabolism links folate and methionine metabolism and this is essential for nucleotide synthesis in the cells. Alterations in one-carbon metabolism are associated with cardiovascular disease (CVD), type 2 diabetes and cancer. Our aim was to investigate whether SNPs in antioxidant-enzyme genes impact the concentrations of folate in serum (s-folate), plasma total homocysteine (p-tHcy) and total glutathione in plasma (p-tGSH) in healthy subjects after supplementation with folic acid.

METHODS

In a randomized, double blind, crossover study, healthy subjects received 0.8 mg folic acid per day or a placebo for two weeks. Twenty-four male, and sixty-seven female subjects participated in this study. Participants were aged 36.4 ± 14.8 years (mean ± SD). We studied SNPs in six genes by PCR methods. The concentrations of s-folate, p-tHcy and p-tGSH were measured in fasting samples with Cobas and an HPLC-fluorescence method. Student T-tests and ANOVA were used for the statistical calculations.

MAIN FINDINGS

The subjects with SNP (rs4880) in superoxide dismutase (SOD2) gene (CC) allele had higher concentrations of s-folate and lower concentrations of p-tHcy than subjects with (CT + TT) alleles, (p = 0.014 and p = 0.012). Contrary to SOD2 (CC) allele, the subjects with SNP (rs1001179) catalase (CAT) CC allele had lower concentrations of s-folate (p = 0.029), higher concentrations of p-tGSH (0.017) and higher concentrations of p-tHcy before and after folic acid supplementations (p = 0.015, p = 0.017) than the subjects with (CT + TT) allele. Glutathione transferase (theta)1 (GST-T1) genotype was associated with higher concentrations of s-folate than GST-T0 before (p = 0.025) and after folic acid supplementation (p = 0.047). SNP (rs1050450) in glutathione peroxidase (GPX1) had also impact on the concentrations of p-tGSH (p = 0.011) in healthy subjects.

CONCLUSION

SNPs in SOD2 (rs4880), CAT (rs1001179), and GST1 impact the concentrations of s-folate, and p-tHcy in healthy subjects before and after folic acid supplementation. Our findings suggest that SNPs in antioxidant-genes have a role in health and disease by impacting the concentrations of s-folate, p-tHcy and p-tGSH.

Polymorphic variants of the hOGG1, APEX1, XPD, SOD2, and CAT genes involved in DNA repair processes and antioxidant defense and their association with breast cancer risk

Breast cancer is one of the leading causes of mortality among women. The most frequently encountered tumors are luminal tumors. Associations of polymorphisms in the hOGG1 (rs1052133), APEX1 (rs1130409), XPD (rs13181), SOD2 (rs4880), and CAT (rs1001179) genes were studied in 313 nonsmoking postmenopausal patients with luminal B subtype breast cancer. The control group consisted of 233 healthy nonsmoking postmenopausal women. Statistically significant associations of the XPD and APEX1 gene polymorphisms with the risk of developing luminal B Her2-negative subtype of breast cancer were observed in a log-additive inheritance model, while the CAT gene polymorphism showed an association in a dominant inheritance model (OR = 1.41; CI 95 %: 1.08-1.85; Padj.= 0.011; OR = 1.39; CI 95 %: 1.07-1.81; Padj = 0.013 и OR = 1.70; CI 95 %: 1.19-2.43; Padj = 0.004, respectively). In the group of elderly women (aged 60-74 years), an association of the CAT gene polymorphism with the risk of developing luminal B subtype of breast cancer was found in a log-additive inheritance model (OR = 1.87; 95 % CI: 1.22-2.85; Padj = 0.0024). Using MDR analysis, the most optimal statistically significant 3-locus model of gene-gene interactions in the development of luminal B Her2-negative subtype breast cancer was found. MDR analysis also showed a close interaction and mutual enhancement of effects between the APEX1 and SOD2 loci and the independence of the effects of these loci from the CAT locus in the formation of luminal B subtype breast cancer.

Systematic Critical Review of Genetic Factors Associated with Cisplatin-induced Ototoxicity: Canadian Pharmacogenomics Network for Drug Safety 2022 Update

BACKGROUND

Cisplatin is commonly used to treat solid tumors; however, its use can be complicated by drug-induced hearing loss (ie, ototoxicity). The presence of certain genetic variants has been associated with the development/occurrence of cisplatin-induced ototoxicity, suggesting that genetic factors may be able to predict patients who are more likely to develop ototoxicity. The authors aimed to review genetic associations with cisplatin-induced ototoxicity and discuss their clinical relevance.

METHODS

An updated systematic review was conducted on behalf of the Canadian Pharmacogenomics Network for Drug Safety, based on the Preferred Reporting Items for Systematic reviews and Meta-Analyses 2020 statement. Pharmacogenomic studies that reported associations between genetic variation and cisplatin-induced ototoxicity were included. The evidence on genetic associations was summarized and evaluated, and knowledge gaps that can be used to inform future pharmacogenomic studies identified.

RESULTS

Overall, 40 evaluated reports, considering 47 independent patient populations, captured associations involving 24 genes. Considering GRADE criteria, genetic variants in 2 genes were strongly (ie, odds ratios ≥3) and consistently (ie, replication in ≥3 independent populations) predictive of cisplatin-induced ototoxicity. Specifically, an ACYP2 variant has been associated with ototoxicity in both children and adults, whereas TPMT variants are relevant in children. Encouraging evidence for associations involving several other genes also exists; however, further research is necessary to determine potential clinical relevance.

CONCLUSIONS

Genetic variation in ACYP2 and TPMT may be helpful in predicting patients at the highest risk of developing cisplatin-induced ototoxicity. Further research (including replication studies considering diverse pediatric and adult patient populations) is required to determine whether genetic variation in additional genes may help further identify patients most at risk.

The role of SOD2 and NOS2 genes in the molecular aspect of bladder cancer pathophysiology

Bladder cancer (BC) is a severe health problem of the genitourinary system and is characterised by a high risk of recurrence. According to the recent GLOBOCAN report, bladder cancer accounts for 3% of diagnosed cancers in the world, taking 10th place on the list of the most common cancers. Despite numerous studies, the full mechanism of BC development remains unknown. Nevertheless, precious results suggest a crucial role of oxidative stress in the development of BC. Therefore, this study explores whether the c. 47 C > T (rs4880)-SOD2, (c. 1823 C > T (rs2297518) and g.-1026 C > A (rs2779249)-NOS2(iNOS) polymorphisms are associated with BC occurrence and whether the bladder carcinogenesis induces changes in SOD2 and NOS2 expression and methylation status in peripheral blood mononuclear cells (PBMCs). In this aim, the TaqMan SNP genotyping assay, TaqMan Gene Expression Assay, and methylation-sensitive high-resolution melting techniques were used to genotype profiling and evaluate the expression of the genes and the methylation status of their promoters, respectively. Our findings confirm that heterozygote of the g.-1026 C > A SNP was associated with a decreased risk of BC. Moreover, we detected that BC development influenced the expression level and methylation status of the promoter region of investigated genes in PBMCs. Concluding, our results confirmed that oxidative stress, especially NOS2 polymorphisms and changes in the expression and methylation of the promoters of SOD2 and NOS2 are involved in the cancer transformation initiation of the cell urinary bladder.

Predicting Hearing Loss in Testicular Cancer Patients after Cisplatin-Based Chemotherapy

Testicular cancer is predominantly curable, but the long-term side effects of chemotherapy have a severe impact on life quality. In this research study, we focus on hearing loss as a part of overall chemotherapy-induced ototoxicity. This is a unique approach where we combine clinical data from the acclaimed nationwide Danish Testicular Cancer (DaTeCa)-Late database. Clinical and genetic data on 433 patients were collected from hospital files in October 2014. Hearing loss was classified according to the FACT/GOG-Ntx-11 version 4 self-reported Ntx6. Machine learning models combining a genome-wide association study within a nested cross-validated logistic regression were applied to identify patients at high risk of hearing loss. The model comprising clinical and genetic data identified 67% of the patients with hearing loss; however, this was with a false discovery rate of 49%. For the non-affected patients, the model identified 66% of the patients with a false omission rate of 19%. An area under the receiver operating characteristic (ROC-AUC) curve of 0.73 (95% CI, 0.71-0.74) was obtained, and the model suggests genes SOD2 and MGST3 as important in improving prediction over the clinical-only model with a ROC-AUC of 0.66 (95% CI, 0.65-0.66). Such prediction models may be used to allow earlier detection and prevention of hearing loss. We suggest a possible biological mechanism for cisplatin-induced hearing loss development. On confirmation in larger studies, such models can help balance treatment in clinical practice.

Antioxidant Genetic Variants Modify Echocardiography Indices in Long COVID

Although disturbance of redox homeostasis might be responsible for COVID-19 cardiac complications, this molecular mechanism has not been addressed yet. We have proposed modifying the effects of antioxidant proteins polymorphisms (superoxide dismutase 2 (SOD2), glutathione peroxidase 1 (GPX1), glutathione peroxidase 3 (GPX3) and nuclear factor erythroid 2-related factor 2, (Nrf2)) in individual susceptibility towards the development of cardiac manifestations of long COVID-19. The presence of subclinical cardiac dysfunction was assessed via echocardiography and cardiac magnetic resonance imaging in 174 convalescent COVID-19 patients. SOD2, GPX1, GPX3 and Nrf2 polymorphisms were determined via the appropriate PCR methods. No significant association of the investigated polymorphisms with the risk of arrhythmia development was found. However, the carriers of variant GPX1*T, GPX3*C or Nrf2*A alleles were more than twice less prone for dyspnea development in comparison with the carriers of the referent ones. These findings were even more potentiated in the carriers of any two variant alleles of these genes (OR = 0.273, and p = 0.016). The variant GPX alleles were significantly associated with left atrial and right ventricular echocardiographic parameters, specifically LAVI, RFAC and RV-EF (p = 0.025, p = 0.009, and p = 0.007, respectively). Based on the relation between the variant SOD2*T allele and higher levels of LV echocardiographic parameters, EDD, LVMI and GLS, as well as troponin T (p = 0.038), it can be proposed that recovered COVID-19 patients, who are the carriers of this genetic variant, might have subtle left ventricular systolic dysfunction. No significant association between the investigated polymorphisms and cardiac disfunction was observed when cardiac magnetic resonance imaging was performed. Our results on the association between antioxidant genetic variants and long COVID cardiological manifestations highlight the involvement of genetic propensity in both acute and long COVID clinical manifestations.

Omics biomarkers and an approach for their practical implementation to delineate health status for personalized nutrition strategies

Personalized nutrition (PN) has gained much attention as a tool for empowerment of consumers to promote changes in dietary behavior, optimizing health status and preventing diet related diseases. Generalized implementation of PN faces different obstacles, one of the most relevant being metabolic characterization of the individual. Although omics technologies allow for assessment the dynamics of metabolism with unprecedented detail, its translatability as affordable and simple PN protocols is still difficult due to the complexity of metabolic regulation and to different technical and economical constrains. In this work, we propose a conceptual framework that considers the dysregulation of a few overarching processes, namely Carbohydrate metabolism, lipid metabolism, inflammation, oxidative stress and microbiota-derived metabolites, as the basis of the onset of several non-communicable diseases. These processes can be assessed and characterized by specific sets of proteomic, metabolomic and genetic markers that minimize operational constrains and maximize the information obtained at the individual level. Current machine learning and data analysis methodologies allow the development of algorithms to integrate omics and genetic markers. Reduction of dimensionality of variables facilitates the implementation of omics and genetic information in digital tools. This framework is exemplified by presenting the EU-Funded project PREVENTOMICS as a use case.

Microalgae as a Nutraceutical Tool to Antagonize the Impairment of Redox Status Induced by SNPs: Implications on Insulin Resistance

Microalgae represent a growing innovative source of nutraceuticals such as carotenoids and phenolic compound which are naturally present within these single-celled organisms or can be induced in response to specific growth conditions. The presence of the unfavourable allelic variant in genes involved in the control of oxidative stress, due to one or more SNPs in gene encoding protein involved in the regulation of redox balance, can lead to pathological conditions such as insulin resistance, which, in turn, is directly involved in the pathogenesis of type 2 diabetes mellitus. In this review we provide an overview of the main SNPs in antioxidant genes involved in the promotion of insulin resistance with a focus on the potential role of microalgae-derived antioxidant molecules as novel nutritional tools to mitigate oxidative stress and improve insulin sensitivity.

Differential association of antioxidative defense genes with white matter integrity in youth bipolar disorder

Oxidative stress is associated with white matter diffusion metrics in adults with bipolar disorder (BD). We examined the association of single-nucleotide polymorphisms in the oxidative stress system, superoxide dismutase-2 (SOD2) rs4880 and glutathione peroxidase-3 (GPX3) rs3792797 with fractional anisotropy (FA) and radial diffusivity (RD) in youth with BD. Participants included 104 youth (age 17.5 ± 1.7 years; 58 BD, 46 healthy controls). Saliva samples were obtained for genotyping, and diffusion tensor imaging was acquired. Voxel-wise whole-brain white matter diffusion analyses controlled for age, sex, and race. There were significant diagnosis-by-SOD2 rs4880 interaction effects for FA and RD in major white matter tracts. Within BD, the group with two copies of the G-allele (GG) showed lower FA and higher RD than A-allele carriers. Whereas within the control group, the GG group showed higher FA and lower RD than A-allele carriers. Additionally, FA was higher and RD was lower within the control GG group compared to the BD GG group. No significant findings were observed for GPX3 rs3793797. The current study revealed that, within matter tracts known to differ in BD, associations of SOD2 rs4880 GG genotype with both FA and RD differed between BD vs healthy control youth. The SOD2 enzyme encoded by the G-allele, has higher antioxidant capacity than the enzyme encoded by the A-allele. We speculate that the current findings of lower FA and higher RD of the BD GG group compared to the other groups reflects attenuation of the salutary antioxidant effects of GG genotype on white matter integrity in youth with BD, in part due to predisposition to oxidative stress. Future studies incorporating other genetic markers and oxidative stress biomarkers are warranted.

The Effect of the Ala16Val Mutation on the Secondary Structure of the Manganese Superoxide Dismutase Mitochondrial Targeting Sequence

Manganese Superoxide Dismutase (MnSOD) represents a mitochondrial protein that scavenges reactive oxygen species (ROS) responsible for oxidative stress. A known single nucleotide polymorphism (SNP) rs4880 on the SOD2 gene, causing a mutation from alanine to valine (Ala16Val) in the primary structure of immature MnSOD, has been associated with several types of cancer and other autoimmune diseases. However, no conclusive correlation has been established yet. This study aims to determine the effect of the alanine to valine mutation on the secondary structure of the MnSOD mitochondrial targeting sequence (MTS). A model for each variant of the MTS was prepared and extensively simulated with molecular dynamics simulations using the CHARMM36m force field. The results indicate that the alanine variant of the MTS preserves a uniform α-helical secondary structure favorable for the protein transport into mitochondria, whereas the valine variant quickly breaks down its α-helix. Thus, the alanine MTS represents the more active MnSOD variant, the benefits of which have yet to be determined experimentally.

Gene expression, levels and polymorphism (Ala16Val) of Mitochondrial Superoxide Dismutase in Tuberculosis patients of Rajasthan

BACKGROUND

Infectious diseases cause redox imbalance and oxidative stress (OS) in host. Superoxide Dismutases(SOD) decrease this OS. SOD2 gene polymorphism can influence the expression and levels of enzyme.

AIM

To investigate the association of genetic polymorphism of MnSOD with enzyme levels and mRNA expression in TB patients.

METHODS

A total of 87 TB patients and 85 healthy individuals participated in the study. The serum SOD2 levels were measured by ELISA. Gene polymorphism was analysed using PCR-RFLP with BsaW1 as the restriction enzyme. Expression was studied by Real-TimePCR. Statistical significance was determined using the Mann-Whitney, Chi-square and Kruskal-Wallis tests and p value < 0.05 was considered statistically significant.

RESULTS

The median(IQR) serum SOD2 levels of TB patients were lower than those of healthy subjects (4.64(6.48) vs 11.35(20.36)ng/mL respectively,p < 0.001). SOD2 expression was significantly down-regulated in TB patients with a fold change value of 0.312. The Val/Val genotype was higher in the patient group than healthy subjects (36.8% vs 23.5%). However, the difference observed between serum SOD2 levels and mRNA expression in the different genotypes were statistically non-significant.

CONCLUSION

Significant difference was found between levels and expression of SOD2 in TB patients and healthy controls, but not for SOD2 gene polymorphism.

Analysis of SOD2 rs4880 Genetic Variant in Patients with Alzheimer's Disease

A few gene loci that contribute to Alzheimer's Disease (AD) onset have been identified. Few studies have been published about the relationship between SOD2 rs4880 single nucleotide variant and AD, revealing inconsistent results. Therefore, the aim of the current study is to further examine the role of the SOD2 rs4880 in AD. We performed a case-control study with a total of 641 subjects (320 patients with probable AD, and 321 healthy controls). The statistical analysis was performed assuming five genetic models. The threshold for statistical significance was set at 0.05. The results revealed no association between SOD2 rs4880 and AD in any of the assumed genetic models that were examined [log-additive OR = 0.95 (0.76-1.19), over-dominant OR = 1.15 (0.85-1.57), recessive OR = 0.85 (0.59-1.22), dominant OR = 1.03 (0.72-1.47), and co-dominant OR1 = 1.10 (0.75-1.60) and OR2 = 0.90 (0.58-1.40)]. Adjustment for sex and subgroup analyses based on sex did not reveal any statistically significant results either. Based on our findings, SOD2 rs4880 does not appear to play a determining role in the risk of developing AD. Larger studies are warranted to elucidate the connection between rs4880 and AD.

Genetic Variability of Inflammation and Oxidative Stress Genes Affects Onset, Progression of the Disease and Survival of Patients with Amyotrophic Lateral Sclerosis

Inflammation and oxidative stress are recognized as important contributors to amyotrophic lateral sclerosis (ALS) disease pathogenesis. Our aim was to evaluate the impact of selected single-nucleotide polymorphisms in genes involved in inflammation and oxidative stress on ALS susceptibility and modification. One-hundred-and-eighty-five ALS patients and 324 healthy controls were genotyped for nine polymorphisms in seven antioxidant and inflammatory genes using competitive allele-specific PCR. Logistic regression; nonparametric tests and survival analysis were used in the statistical analysis. Investigated polymorphisms were not associated with ALS susceptibility. Carriers of at least one polymorphic SOD2 rs4880 T or IL1B rs1071676 C allele more often had bulbar ALS onset (p = 0.036 and p = 0.039; respectively). IL1B rs1071676 was also associated with a higher rate of disease progression (p = 0.015). After adjustment for clinical parameters; carriers of two polymorphic IL1B rs1071676 C alleles had shorter survival (HR = 5.02; 95% CI = 1.92–13.16; p = 0.001); while carriers of at least one polymorphic CAT rs1001179 T allele had longer survival (HR = 0.68; 95% CI = 0.47–0.99; p = 0.046). Our data suggest that common genetic variants in the antioxidant and inflammatory pathways may modify ALS disease. Such genetic information could support the identification of patients that may be responsive to the immune or antioxidant system—based therapies.

SOD2 V16A amplifies vascular dysfunction in sickle cell patients by curtailing mitochondria complex IV activity

Superoxide dismutase 2 (SOD2) catalyzes the dismutation of superoxide to hydrogen peroxide in mitochondria, limiting mitochondrial damage. The SOD2 amino acid valine-to-alanine substitution at position 16 (V16A) in the mitochondrial leader sequence is a common genetic variant among patients with sickle cell disease (SCD). However, little is known about the cardiovascular consequences of SOD2V16A in SCD patients or its impact on endothelial cell function. Here, we show SOD2V16A associates with increased tricuspid regurgitant velocity (TRV), systolic blood pressure, right ventricle area at systole, and declined 6-minute walk distance in 410 SCD patients. Plasma lactate dehydrogenase, a marker of oxidative stress and hemolysis, significantly associated with higher TRV. To define the impact of SOD2V16A in the endothelium, we introduced the SOD2V16A variant into endothelial cells. SOD2V16A increases hydrogen peroxide and mitochondrial reactive oxygen species (ROS) production compared with controls. Unexpectedly, the increased ROS was not due to SOD2V16A mislocalization but was associated with mitochondrial complex IV and a concomitant decrease in basal respiration and complex IV activity. In sum, SOD2V16A is a novel clinical biomarker of cardiovascular dysfunction in SCD patients through its ability to decrease mitochondrial complex IV activity and amplify ROS production in the endothelium.

The Polymorphisms of Genes Encoding Catalytic Antioxidant Proteins Modulate the Susceptibility and Progression of Testicular Germ Cell Tumor

Simple Summary

Testicular cancer is the most common malignancy in the population of young and reproductively active men. The risk factors for its occurrence are not fully elucidated. Undescended testicle remains the main risk factor; however, more precise molecular studies associate genetic variations with susceptibility to testicular tumor development and progression. In this study, we found that specific variations in genes encoding antioxidant defense proteins confer risks of testicular cancer development and progression and, therefore, helps to identify subjects at higher risk, as well as those requiring additional diagnostics and more intensive forms of treatment.

Abstract

The simultaneous analysis of redox biomarkers and polymorphisms encoding for regulatory and catalytic antioxidant proteins was performed in order to evaluate their potential role in the development of testicular germ cell tumor (GCT), as well as the progression of the disease. NRF2 (rs6721961), GSTM3 (rs1332018), SOD2 (rs4880) and GPX3 (rs8177412) polymorphisms were assessed in 88 patients with testicular GCT (52 with seminoma) and 88 age-matched controls. The plasma levels of 8-hydroxy-2′-deoxyguanosine (8-OHdG), thiol groups and the plasma activity of glutathione peroxidase were measured. A significant association between variant GPX3*TC+CC genotype and risk of overall testicular GCT, as well as seminoma development, was found. Moreover, carriers of variant SOD2*TT genotype were at almost 3-fold increased risk of seminoma development. Interestingly, combined SOD2*TT/GPX3*TC+CC genotype conferred a 7-fold higher risk for testicular GCT development. Finally, variant GSTM3*AC+CC genotype was associated with a higher risk for the development of advanced diseased. The presence of assessed genetic variants was not associated with significantly higher levels of redox biomarkers in both testicular GCT patients, as well as in those diagnosed with seminoma. In conclusion, the polymorphic expression of certain antioxidant enzymes might affect susceptibility toward testicular GCT development, as well as the progression of the disease.

Androgen-Dependent Prostate Cancer Cells Reprogram Their Metabolic Signature upon GLUT1 Upregulation by Manganese Superoxide Dismutase

Prostate cancer is the second leading cause of cancer in men across the globe. The prostate gland accounts for some unique glycolytic metabolic characteristics, which causes the metabolic features of prostate tumor initiation and progression to remain poorly characterized. The mitochondrial superoxide dismutase (SOD2) is one of the major redox metabolism regulators. This study points out SOD2 as one major regulator for both redox and glycolytic metabolism in prostate cancer. SOD2 overexpression increases glucose transporter GLUT-1 and glucose uptake. This is not an insulin-mediated effect and seems to be sex-dependent, being present in male mice only. This event concurs with a series of substantial metabolic rearrangements at cytoplasmic and mitochondrial level. A concomitant decrease in glycolytic and pentose phosphate activity, and an increase in electron transfer in the mitochondrial electronic chain, were observed. The Krebs Cycle is altered to produce amino-acid intermediates by decreasing succinate dehydrogenase. This in turn generates a 13-fold increase in the oncometabolite succinate. The protein energy sensor AMPK is decreased at basal and phosphorylated levels in response to glucose deprivation. Finally, preliminary results in prostate cancer patients indicate that glandular areas presenting high levels of SOD2 show a very strong correlation with GLUT-1 protein levels (R² = 0.287 p-value < 0.0001), indicating that in patients there may exist an analogous phenomenon to those observed in cell culture and mice.

Oxidative Stress in Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is a challenging disease caused by multiple factors, which may partly explain why it still remains an orphan of adequate therapies. This review highlights the interaction between oxidative stress (OS) and disturbed lipid metabolism. Several reactive oxygen species generators, including those produced in the gastrointestinal tract, contribute to the lipotoxic hepatic (and extrahepatic) damage by fatty acids and a great variety of their biologically active metabolites in a “multiple parallel-hit model”. This leads to inflammation and fibrogenesis and contributes to NAFLD progression. The alterations of the oxidant/antioxidant balance affect also metabolism-related organelles, leading to lipid peroxidation, mitochondrial dysfunction, and endoplasmic reticulum stress. This OS-induced damage is at least partially counteracted by the physiological antioxidant response. Therefore, modulation of this defense system emerges as an interesting target to prevent NAFLD development and progression. For instance, probiotics, prebiotics, diet, and fecal microbiota transplantation represent new therapeutic approaches targeting the gut microbiota dysbiosis. The OS and its counter-regulation are under the influence of individual genetic and epigenetic factors as well. In the near future, precision medicine taking into consideration genetic or environmental epigenetic risk factors, coupled with new OS biomarkers, will likely assist in noninvasive diagnosis and monitoring of NAFLD progression and in further personalizing treatments.

The association of SOD2 and GST gene polymorphisms with the risk of development and prognosis of papillary renal cell carcinoma

Introduction: Redox imbalance is an important factor in both carcinogenesis and progression of renal cell carcinoma. Numerous studies are focused on finding potential biomarkers that can aid in early detection, as well as in monitoring disease progression. Among the candidates there are genes coding for antioxidant enzymes - superoxide dismutase 2 (SOD2) and glutathione S -transferase (GST). Aim: This study aims to assess the role of SOD2 and GST genes polymorphisms as risk biomarkers for papillary renal cell carcinoma (pRCC), along with their impact on the survival of these patients. Material and methods: This study included 39 patients and 336 controls. The following polymorphisms were determined by appropriate PCR methods: SOD2 (rs4880), GSTA1 C69T, GSTM1, GSTT1, and GSTP1 (rs1695) . ELISA method was used to measure 8-hydroxy-2'-deoxyguanosine (8-OHdG) and benzo(a)pyrene diol epoxide (BPDE)-DNA adducts plasma level. The effect of the polymorphisms on postoperative prognosis was examined using the available survival data. Results: There was no significant difference in the distribution of SOD2, GSTA1, GSTM1, and GSTT1 gene variants between patients and controls (p > 0.05). However GSTP1 variant (GSTP1 * IleVal + ValVal) genotype was statistically significantly more frequent in patients compared to controls (p < 0.05). Similarly, carriers of GSTP1 variant genotype were at significantly higher risk of developing carcinoma compared to carriers of GSTP1 reference genotype (OR = 16.103, 95% IP = 2.036 - 127.398). There was no association between the level of both 8-OHdG and BPDE-DNA adducts, and different genotypes (p > 0.05). The investigated polymorphisms did not show any prognostic significance (p > 0.05). Conclusion: These results indicate that the GSTP1 variant genotype was related to an increased risk of papillary renal cell carcinoma development. In order to fully understand the effect of investigated polymorphisms as a potential risk and prognostic biomarkers of this cancer, further research with a bigger sample size and longer follow-up are required.

Association between superoxide dismutase 2, glutathione peroxidase 1, xeroderma pigmentosum group d gene variations, and head and neck squamous cell cancer susceptibility

As oxidative stress is implicated in the pathogenesis of head and neck squamous cell cancer (HNSCC), the functions of antioxidant enzyme systems and DNA repair proteins are critical in the development of cancer. To investigate the role of genetic polymorphisms of the antioxidant superoxide dismutase 2 (SOD2) Val16Ala, glutathione peroxidase 1 (GPX1) Pro198Leu, and the DNA repair Xeroderma Pigmentosum Group D (XPD) Lys751Gln genes under exogenous risk factors, including smoking and alcohol consumption, in HNSCC carcinogenesis, we conducted a case-control study on 139 unrelated cases and 265 non-cancer controls. Polymorphisms were analyzed in additive, dominant and recessive genetic models, individually and in an interaction model. Carriers of the T allele of SOD2 were associated with an increased risk for HNSCC in the overall subgroups of males and smokers; similarly, the T allele of GPX1 was associated with elevated risk in the overall and smoker subgroup. A 12.47-fold increased risk was observed for the carriers of GPX1 TT, SOD2 CT and XPD CC genotypes for HNSCC. This is the first study presenting the potential roles of SOD2, GPX1 and XPD polymorphisms in interaction and under three genetic models in the development of HNSCC. The results suggest that these polymorphisms slightly modify the risk in HNSCC development individually but are significantly higher when they functioned and were evaluated together.

Development of cervical intraepithelial lesions and cervical cancer is not influenced by SOD2 RS4880 polymorhism

Some of the more than 200 known HPV types are essential for cervical cancer development, the third type of cancer most incident in the female population. However, for the malignant transformation occur, some cofactors are needed, as the reactive oxygen species (ROS), which can be neutralized by the antioxidant system. The SOD2 enzyme, encoded by the same name gene, is found in mitochondria and is part of the first line of defense against oxidative stress damage. Genetic polymorphisms can act by altering the efficiency of the enzyme, among which the most studied is the rs4880. Thus, the purpose of the present study was to evaluate the association of this polymorphism with HPV infection and the development of low and high grade squamous intraepithelial lesions (LSIL and HSIL) and cervical cancer, in 407 women attended by the public health system in Brazil. HPV detection in cervical secretion samples was carried out by polymerase chain reaction (PCR) and blood samples were used for polymorphism genotyping through PCR followed by restriction fragment length polymorphism (RFLP). PCR and restriction products were subjected to 10% polyacrylamide gel electrophoresis. HPV negative group (control) included 158 women and the HPV positive group (case) 249 women. The infected group was divided into No Lesion (n = 90), LSIL (n = 20), HSIL (n = 67) and cervical cancer (n = 72). The data found on socio-epidemiological characteristics and habits corroborated with data found in the literature. The distribution of genotypes in the control group was 51.9% women TC, 29.8% TT and 18.3% CC. In the case group, the distribution was 55.0% women TC, 26.1% TT and 18.9% CC. This is the first study evaluating the influence of SOD2 rs4880 polymorphism on HPV infection, the development of cervical intraepithelial lesions and cervical cancer in a Brazilian population, although additional studies are needed to corroborate the results.

The Association of Polymorphisms in Nrf2 and Genes Involved in Redox Homeostasis in the Development and Progression of Clear Cell Renal Cell Carcinoma

Deleterious effects of SNPs found in genes encoding transcriptional factors, as well as antioxidant and detoxification enzymes, are disputable; however, their functional significance seems to modify the risk for clear cell renal cell carcinoma (ccRCC) development and progression. We investigated the effect of specific Nrf2, SOD2, GPX1 gene variants and GSTP1ABCD haplotype on ccRCC risk and prognosis and evaluated the association between GSTP1 and regulatory (JNK1/2) and executor (caspase-3) apoptotic molecule expression in ccRCC tissue samples and the presence of GSTP1 : JNK1/2 protein : protein interactions. Genotyping was performed in 223 ccRCC patients and 336 matched controls by PCR-CTTP and qPCR. Protein expression was analyzed using immunoblot, while the existence of GSTP1 : JNK1 protein : protein interactions was investigated by immunoprecipitation experiments. An increased risk of ccRCC development was found among carriers of variant genotypes of both SOD2 rs4880 and GSTP1 rs1695 polymorphisms. Nrf2 rs6721961 genetic polymorphism in combination with both rs4880 and rs1695 showed higher ccRCC risk as well. Haplotype analysis revealed significant risk of ccRCC development in carriers of the GSTP1C haplotype. Furthermore, GSTP1 variant forms seem to affect the overall survival in ccRCC patients, and the proposed molecular mechanism underlying the GSTP1 prognostic role might be the presence of GSTP1 : JNK1/2 protein : protein interactions.

Antioxidants-Related Superoxide Dismutase (SOD), Catalase (CAT), Glutathione Peroxidase (GPX), Glutathione-S-Transferase (GST), and Nitric Oxide Synthase (NOS) Gene Variants Analysis in an Obese Population: A Preliminary Case-Control Study

Oxidative stress and antioxidants play an important role in obesity etiopathology. Genetic variants, including single nucleotide polymorphisms (SNPs) of the antioxidant-related genes, may impact disease risk in several populations. This preliminary study aimed to explore the association of 12 SNPs related to superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione-S-transferase (GST), and nitric oxide synthase (NOS) genes with obesity susceptibility in a Saudi population. A total of 384 unrelated participants, including 154 (40.1%) obese individuals, were enrolled. TaqMan OpenArray Genotyping assays were used. Six SNPs were significantly more prevalent in obese cohorts: (1) GSTM1 rs1056806*C/T; (2) SOD1 rs2234694*A; (3) SOD2 rs4880*G; (4) SOD3 rs2536512*A; (5) GPX1 rs1800668*A; (6) NOS3 rs1799983*G. Four SNPs were associated with higher obesity risk under heterozygote and dominant models for GSTM1 rs1056806 (C/T), homozygote model for SOD2 rs4880 (A/G), and homozygote and recessive models for GPX1 rs1800668 (A/G). In contrast, SOD3 rs2536512 (A/G) were less likely to be obese under heterozygote and dominant models. The CGAG, CAAA, TGGG, and CGAG combined genotypes showed a higher risk of obesity. In conclusion, the present results suggest that oxidative-stress-related genetic determinants could significantly associate with obesity risk in the study population.

Single-Nucleotide Polymorphisms in Oxidative Stress-Related Genes and the Risk of a Stroke in a Polish Population-A Preliminary Study

The present preliminary case-control study was undertaken to detect the potential association of six single nucleotide polymorphisms (SNPs) in oxidative stress-related genes: SOD2 (c.47T > C; rs4880), CAT (c.-89A > T; rs7943316), GPX4 (c.660T > A; rs713041), NOS1 (g.117803515C > T; rs1879417) and NOS2 (c.1823C > T; rs2297518 and c.-227G > C; rs10459953) and the occurrence of a stroke. The SNPs were determined using the TaqMan^® Allelic Discrimination Assay in 107 patients with strokes and 107 age- and sex-matched individuals who had not experienced cerebrovascular accidents. The T alleles of the rs4880 were positively correlated with a stroke (bootstrap OR 1.31; 1.07-1.59 95% CI). In the case of the rs713041, an association with the T allele was found (bootstrap OR 1.36; 1.12-1.67). In addition, the occurrence of a stroke was associated with the presence of the C allele of the rs1879417 (bootstrap OR 1.32; 1.09-1.61). We also found that the C/C genotype and C allele of the rs2297518 increased the risk of a stroke (bootstrap ORs 7.00; 4.34-11.29 and 4.96; 3.88-6.34, respectively). Moreover, the C allele of the rs10459953 was associated with an increased occurrence of this disease (bootstrap OR 1.31; 1.08-1.60). These results indicated that genetics variants in the SOD2, GPX4, NOS1 and NOS2 might be associated with susceptibility to strokes in the Polish population.

Association of Genetic Polymorphisms in Oxidative Stress and Inflammation Pathways with Glaucoma Risk and Phenotype

Oxidative stress and neuroinflammation are involved in the pathogenesis and progression of glaucoma. Our aim was to evaluate the impact of selected single-nucleotide polymorphisms in inflammation and oxidative stress genes on the risk of glaucoma, the patients’ clinical characteristics and the glaucoma phenotype. In total, 307 patients with primary open-angle glaucoma or ocular hypertension were enrolled. The control group included 339 healthy Slovenian blood donors. DNA was isolated from peripheral blood. Genotyping was performed for SOD2 rs4880, CAT rs1001179, GPX1 rs1050450, GSTP1 rs1695, GSTM1 gene deletion, GSTT1 gene deletion, IL1B rs1143623, IL1B rs16944, IL6 rs1800795 and TNF rs1800629. We found a nominally significant association of GSTM1 gene deletion with decreased risk of ocular hypertension and a protective role of IL1B rs16944 and IL6 rs1800629 in the risk of glaucoma. The CT and TT genotypes of GPX1 rs1050450 were significantly associated with advanced disease, lower intraocular pressure and a larger vertical cup–disc ratio. In conclusion, genetic variability in IL1B and IL6 may be associated with glaucoma risk, while GPX and TNF may be associated with the glaucoma phenotype. In the future, improved knowledge of these pathways has the potential for new strategies and personalised treatment of glaucoma.

Val16A SOD2 Polymorphism Promotes Epithelial-Mesenchymal Transition Antagonized by Muscadine Grape Skin Extract in Prostate Cancer Cells

Epithelial–mesenchymal transition (EMT), a key event in cancer metastasis, allows polarized epithelial cells to assume mesenchymal morphologies, enhancing invasiveness and migration, and can be induced by reactive oxygen species (ROS). Val16A (Ala) SOD2 polymorphism has been associated with increased prostate cancer (PCa) risk. We hypothesized that SOD2 Ala single nucleotide polymorphism (SNP) may promote EMT. We analyzed SOD2 expression and genotype in various prostate cell lines. Stable overexpression of Ala-SOD2 or Val-SOD2 allele was performed in Lymph Node Carcinoma of the Prostate (LNCaP) cells followed by analysis of intracellular ROS and EMT marker protein expression. Treatments were performed with muscadine grape skin extract (MSKE) antioxidant, with or without addition of H₂O₂ to provide further oxidative stress. Furthermore, MTS cell proliferation, cell migration, and apoptosis assays were completed. The results showed that SOD2 expression did not correlate with tumor aggressiveness nor SOD2 genotype. We demonstrated that the Ala-SOD2 allele was associated with marked induction of EMT indicated by higher Snail and vimentin, lower E-cadherin, and increased cell migration, when compared to Val-SOD2 allele or Neo control cells. Ala-SOD2 SNP cells exhibited increased levels of total ROS and superoxide and were more sensitive to co-treatment with H₂O₂ and MSKE, which led to reduced cell growth and increased apoptosis. Additionally, MSKE inhibited Ala-SOD2 SNP-mediated EMT. Our data indicates that treatment with a combination of H₂O₂-generative drugs, such as certain chemotherapeutics and antioxidants such as MSKE that targets superoxide, hold promising therapeutic potential to halt PCa progression in the future.

Glutathione S-Transferase (GSTT1 rs17856199) and Nitric Oxide Synthase (NOS2 rs2297518) Genotype Combination as Potential Oxidative Stress-Related Molecular Markers for Type 2 Diabetes Mellitus

BACKGROUND

Deregulation of the antioxidant enzymes was implicated in pathogenesis and complications of type 2 diabetes mellitus (T2DM). The data relate the genetic variants of these enzymes to T2DM are inconsistent among various populations.

PURPOSE

We aimed to explore the association of 13 genetic variants of "superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and nitric oxide synthase (NOS)" with T2DM susceptibility and the available clinical laboratory data.

SUBJECTS AND METHODS

A total of 384 individuals were enrolled in this work. Different genotypes of the genes mentioned above were characterized using TaqMan OpenArray Genotyping assays on a Real-Time polymerase chain reaction system.

RESULTS

After age- and sex-adjustment, among the studied 13 variants, GSTT1 rs17856199 was associated with T2DM under homozygote (OR=3.42; 95% CI:1.04-11.2, p=0.031), and recessive (OR=3.57; 95% CI: 1.11-11.4, p=0.029) comparison models. The NOS2 rs2297518*A allele was more frequent among the T2DM cohort (58.1% vs 35.4%, p<0.001) and showed a dose-response effect; being heterozygote was associated with higher odds for developing DM (OR=4.06, 95% CI=2.13-7.73, p<0.001), whereas being AA homozygote had double the risk (OR=9.06, 95% CI=3.41-24.1, p<0.001). Combined NOS2 rs2297518*A and either GSTT1 rs17856199*A or *C genotype carriers were more likely to develop T2DM. Different associations with sex, BMI, hyperglycemia, and/or hyperlipidemia were evident. The principal component analysis revealed NOS2 rs2297518*G, old age, dyslipidemia, high systolic blood pressure, and elevated HbA1c were the main classifiers of T2DM patients.

CONCLUSION

The oxidative stress-related molecular markers, GSTT1 rs17856199 and NOS2 rs2297518 variants were significantly associated with T2DM risk and phenotype in the study population.

Genetics of methamphetamine use disorder: A systematic review and meta-analyses of gene association studies

Genetic susceptibility to methamphetamine use disorder is poorly understood. No twin or adequately powered genome-wide association studies (GWASs) have been conducted. However, there are a large number of hypothesis-driven candidate gene association studies, which were systematically reviewed herein. Seventy-six studies were identified, investigating markers of 75 different genes. Allele frequencies, odds ratios, 95 % confidence intervals and power were calculated. Risk of bias was also assessed as a quality measure. Meta-analyses were conducted for gene markers if three or more studies were available. Eleven markers from adequately powered studies were significantly associated with methamphetamine use disorder, with Fatty Acid Amide Hydrolase (FAAH) and Brain Derived Neurotrophic Factor (BDNF) representing promising targets. Limitations of these studies include unclear rationale for candidate gene selection, low power and high risk of bias. Future research should include replications to enable more meta-analyses, well-powered GWASs or whole exome or genome sequencing, as well as twin and family studies to further complement the findings of this review to uncover genetic contributions toward methamphetamine use disorder.

MnSOD Ala16Val polymorphism in cognitive dysfunction in patients with epilepsy: A relationship with oxidative and inflammatory markers

OBJECTIVE

The objective of the study was to evaluate the neurocognitive profile and its relation with Ala16ValMnSOD polymorphism in epilepsy and if these clinical parameters are linked to oxidative stress and inflammatory markers.

METHODS

Patients with epilepsy (n = 31) and healthy subjects (n = 42) were recruited. A neuropsychological evaluation was performed in both groups through a battery of cognitive tests. Oxidative stress, inflammatory markers, apoptotic factors, and deoxyribonucleic acid (DNA) damage were measured in blood samples.

RESULTS

Statistical analyses showed the association of MnSOD Ala16Val polymorphism with cognitive impairment, including praxis, perception, attention, language, executive functions, long-term semantic memory, short-term visual memory, and total memory in patients with epilepsy and Valine-Valine (VV) genotype compared with the control group. Compared with the controls and patients with epilepsy, Alanine-Alanine (AA), and Alanine-Valine (AV) genotype, the patients with epilepsy and VV genotype exhibited higher levels of tumor necrosis factor alpha (TNF-α), interleukin 1β (IL-1β), interleukin 6 (IL-6), activation of caspases 1 and 3 (CASP-1 and -3), and DNA damage. Our findings also showed higher carbonyl protein and thiobarbituric acid reactive substances (TBARS) levels as well as an increased superoxide dismutase (SOD) and acetylcholinesterase (AChE) activities in patients with epilepsy and VV genotype.

CONCLUSION

This study supports the evidence of a distinct neuropsychological profile in patients with epilepsy, especially those with the VV genotype. Furthermore, our results suggest that oxidative and inflammatory pathways may be associated with genetic polymorphism and cognitive dysfunction in patients with epilepsy.

The effect of long-term ultra-endurance exercise and SOD2 genotype on telomere shortening with age

Habitual ultra-endurance exercise seems to promote telomere length maintenance, especially at older ages. In addition, the beneficial effect of ultra-endurance training on biological aging is higher in ultra-trail runners who have been engaged to ultra-endurance training during many years. Finally, and for the first time, this study shows that the SOD2 rs4880 polymorphism has a significant impact on telomere length, as well as on acute inflammatory response to a 107-km trail race.

Association between Dietary Zinc and Selenium Intake, Oxidative Stress-Related Gene Polymorphism, and Colorectal Cancer Risk in Chinese Population - A Case-Control Study

Zinc and selenium may protect against colorectal cancer (CRC) progression through their anti-oxidative effects. This study examined the independent and combined effect of dietary zinc and selenium intake, and polymorphisms of the oxidative stress-related genes (superoxide dismutase 1, superoxide dismutase 2, glutathione peroxidase, and catalase) on CRC risk in a Chinese case-control study. A total of 493 cases and 498 sex and age-matched controls were randomly selected from an ongoing case-control study. Dietary information was assessed through face-to-face interviews using a validated food frequency questionnaire. Multiplex PCR-ligase detection reaction was used for genotyping the target SNPs. Multivariable logistic regression was used to estimate the odds ratios (ORs) and 95% confidence interval (CI). Intake of selenium was found to be inversely associated with CRC risk, while zinc was not associated with CRC risk. The ORs (95% CI) for the highest vs. the lowest quartile were 0.42 (95% CI 0.28, 0.64, P_trend < 0.001) for selenium and 0.96 (95% CI 0.63, 1.47, P_trend = 0.505) for zinc. Combined effect was observed between zinc and SOD1 rs4998557 on CRC risk (P_interaction < 0.05). This study identified a novel diet-gene interaction in the oxidative stress pathway on CRC risk in Chinese population.

Association of SOD2 p.V16A polymorphism with Parkinson's disease: A meta-analysis in Han Chinese

BACKGROUND

Oxidative stress could participate in the pathogenesis of Parkinson's disease (PD). However, the role of genetic variation of superoxide dismutase 2 (SOD2), an important regulator against oxidative stress, in PD remains to be elucidated.

METHODS

We screened SOD2 gene variation by sequencing cDNA from 72 patients with early onset PD. A cohort of PD (n = 609) and ethnically matched controls (n = 681) were further examined for the identified sequence variant by PCR and NaeI restriction analysis.

RESULTS

Only a reported c.47T>C polymorphism (rs4880, SOD2 p.V16A) was found by cDNA sequencing. Case-control study of c.47T>C revealed that genotype and allele frequencies were in Hardy-Weinberg equilibrium in both patients and healthy controls. In a recessive model, those with CC genotype had a 2.61-fold increased risk of PD (95% CI: 1.08-6.30, P = 0.03) compared to subjects with TT and TC genotypes. Significant association between CC genotype and PD in non-smokers was also observed after stratification according to the history of smoking (3.54-fold increased risk of PD, 95% CI: 1.17-10.72, P = 0.02). Meta-analysis by combining studies of Chinese in China, Singapore, and Taiwan (total 2302 cases and 2029 controls) consistently showed CC genotype with increased risk of PD (OR = 1.77, 95% CI: 1.15-2.71, P = 0.01).

CONCLUSION

Our findings demonstrate that SOD2 p.V16A may play a role in the susceptibility of PD in Han Chinese.

Apoptotic Markers Are Increased in Epilepsy Patients: A Relation with Manganese Superoxide Dismutase Ala16Val Polymorphism and Seizure Type through IL-1β and IL-6 Pathways

The MnSOD Ala16Val single nucleotide polymorphism (SNP) has been associated with different diseases. However, there are scarcely studies relating this SNP in epilepsy, a neurologic disease that involves some interacting pathways, such as apoptotic and inflammatory factors. In this sense, we decided to investigate the relationship of MnSOD Ala16Val SNP with apoptotic markers in epilepsy and its relation with inflammatory pathway and seizure type. Ninety subjects were evaluated (47 epilepsies; 43 controls) by questionnaires and laboratorial exams. We observed a higher percentage of VV genotype in the epilepsy group when compared to the control group. IL-1β, IL-6, caspase-1, and caspase-3 levels were increased in the epilepsy group (VV genotype). Furthermore, an important correlation between IL-1β vs. caspase-1 and IL-6 vs. caspase-3 was observed in the epilepsy group (VV genotype). The epilepsy group which presented generalized seizures also demonstrated a positive correlation between IL-1β vs. CASP1 and IL-6 vs. CASP3. Thus, it is a plausible propose that epilepsy patients with VV genotype and generalized seizures present a worse inflammatory and apoptotic status. Our findings suggest that the knowledge of MnSOD Ala16Val polymorphism existence is important to evaluate molecular mechanisms associated to seizure and improve the treatment of these patients.

Superoxide Dismutase 2 Val16Ala Polymorphism is Associated with Amiodarone-Associated Liver Injury

Association of SOD2 V16A single-nucleotide polymorphism (rs4880) with drug hepatotoxicity were reported but relationships with amiodarone prescriptions remained unexplored. Research was an exploratory, controlled prospective clinical trial. Patients hospitalized and treated in Clinical Center in Kragujevac, Serbia (in year 2017) were divided into experimental (using amiodarone, having liver injury, n=29, 19 males, the mean age 66.8±10.4 years), control A (neither amiodarone use nor hepatotoxicity, n=29, 19, 66.1±10.3) and control B group (using amiodarone, not having hepatotoxicity, n=29, 19, 66.8±9.8). From blood samples, among other routine biochemistry, genotyping for SOD2 polymorphism Val16Ala was conducted using real-time PCR method with TaqMan® Genotyping Master Mix and TaqMan® DME Genotyping Assay for rs4880. Patients taking amiodarone and having liver injury were mostly carriers of Val/Val (TT) genotype (13 of 24 patients, 54.2%) while Val/Ala (TC) and Ala/Ala (CC) genotypes prevailed in control group A (19 of 40, 47.5%) and control group B (9 of 23, 39.1%), respectively (2=10.409, p=0.034). Frequency of Val (T) and Ala (C) alleles were 0.51 and 0.49, respectively in the whole study sample (Hardy Weinberg equilibrium, 2=0.56, p=0.454). Carriers of TT genotype had significantly higher ALT (437.0±1158.0 vs 81.9131.5 U/L), total bilirubin (28.320.5 vs 15.313.0 mol/L) and total bile acid concentrations (10.910.2 vs 6.45.3 mol/L) compared to carriers of TC genotype (U=2.331, p=0.020, U=3.204, p=0.001 and U=2.172, p=0.030, respectively). Higher incidence of 47T allele of SOD2 was inpatients with amiodarone-associated liver injury as compared to patients on amiodarone not experiencing hepatotoxic effects.

Detection of metabolic syndrome burden in healthy young adults may enable timely introduction of disease prevention

INTRODUCTION

Metabolic syndrome and associated diseases are a global health problem. Detection of early metabolic modifications that may lead to metabolic syndrome would enable timely introduction of preventive lifestyle modifications.

MATERIAL AND METHODS

In total 103 young, healthy adults were assessed for indicators of metabolic alterations. Anthropometric, lifestyle, genetic and biochemical parameters were assessed. Individuals who fulfilled at least one criterion for diagnosis of metabolic syndrome were assigned to the group with the higher metabolic syndrome burden (B-MeS).

RESULTS

The 34 young healthy individuals who were assigned to the B-MeS group had lower fat-free mass, higher body mass index, waist-to-hip ratio, fat mass, and blood pressure, more visceral fat, they were less physically active, had higher C-reactive protein values and higher catalase activity. Their phenotype was more similar to that of patients diagnosed with metabolic syndrome than the rest of the population.

CONCLUSIONS

Simple anthropometric measurements, lifestyle assessment and basic biochemical measurements can be used to identify young healthy individuals with increased risk for metabolic syndrome. These assessments can be performed at periodic check-ups of the healthy population so that timely diagnosis of B-MeS can be made. As lifestyle factors have a big influence on development or improvement of the MeS, the timely diagnosis for B-MeS would enable an early opportunity for intervention for lifestyle modification in the still healthy population, saving costs and reducing disability adjusted life years.

Associations between the phenotype and genotype of MnSOD and catalase in periodontal disease

BACKGROUND

Periodontal disease is an inflammatory disease in which pathogenic infections trigger a series of inflammatory responses and redox regulation. The hypothesis of this study was that a host's redox regulation, as modified by genetic polymorphisms, may affect periodontal disease activities (including the plaque index (PlI), bleeding on probing (BOP), and pocket depth (PD)) during periodontal therapy.

METHODS

In total, 175 patients diagnosed with periodontitis were recruited from the Department of Periodontology, Taipei Medical University Hospital. Both saliva samples and clinical measurements (PlI, BOP, and PD) were taken at the baseline and at 1 month after completing treatment. Salivary manganese superoxide dismutase (MnSOD) and catalase, and corresponding genetic polymorphisms (MnSOD, T47C, rs4880 and Catalase, C-262 T, rs1001179) were determined. The extent of change (Δ) of MnSOD or catalase was calculated by subtracting the concentration after completing treatment from that at the baseline.

RESULTS

Subjects who carried the Catalase CC genotype had significantly higher salivary MnSOD or catalase levels. The MnSOD genotype had a significant effect on the percentage of PDs of 4~9 mm (p = 0.02), and salivary ΔMnSOD had a significant effect on the PlI (p = 0.03). The Catalase genotype had a significant effect on the PlI (p = 0.01~0.04), but the effect was not found for the mean PlI or PD. There was a significant interaction between the MnSOD genotype and salivary ΔMnSOD on PDs of 4~9 mm. After adjusting for gender, years of schooling, smoking status, and alcohol consumption, subjects with ΔMnSOD of < 0 μg/ml or Δcatalase of < 0 μg/ml had significantly higher 5.58- or 5.17-fold responses to scaling and root planing treatment.

CONCLUSIONS

The MnSOD T47C genotype interferes with the phenotype of salivary antioxidant level, alters MnSOD levels, and influences the PD recovery. MnSOD and catalase gene polymorphism associated with phenotype expression and susceptibility in periodontal root planing treatment responses.

Novel Insights into the Genetic Landscape of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD), the most common liver disorder worldwide, is epidemiologically associated with overweight, insulin resistance features and type 2 diabetes, and can progress to advanced liver fibrosis and hepatocellular carcinoma. Genetic factors play an important role in the development of NAFLD, which is a multifactorial disease. Several common naturally occurring variants modulating lipid and retinol metabolism in hepatocytes predispose to NAFLD development and progression, in particular those in PNPLA3, TM6SF2, MBOAT7, and HSD17B13. In addition, genetic variants that protect hepatic cells from oxidative stress modulate the susceptibility to progressive NAFLD. Although the molecular mechanisms linking these genetic variants with liver disease are not yet fully understood, hepatic fat has emerged as a major driver of the disease, while altered retinol metabolism and mitochondrial oxidative stress play a role in determining the development of advanced NAFLD.

Alterations of Mitochondrial Biology in the Oral Mucosa of Chilean Children with Autism Spectrum Disorder (ASD)

Autistic Spectrum Disorder (ASD) is characterized by the impairment of socio-communicative skills and the presence of restricted and stereotyped behavior patterns. Recent researches have revealed the influence of mitochondrial physiology on the development of ASD. Several research groups have identified defects in respiratory complexes, coenzyme-Q10 deficiency, increased oxidative damage, decreased of superoxide dismutase (SOD2). A study on the influence of mitochondrial physiology on the development of ASD can provide new alternatives and challenges. That is why we set ourselves the general objective to initiate studies of mitochondrial physiology in Chilean children with ASD. A sample of oral mucosa was collected in a group of 12 children diagnosed with ASD and 12 children without ASD. In children with ASD, we found a significant increase in mitochondrial DNA levels. Likewise, in these children, an increase in the protein oxidation was observed. Finally, a downward trend in the expression of the HIGD2A and SOD2 genes was observed, while DRP1, FIS1, MFN1, MFN2, and OPA1 gene expression show an upward trend. The increment of mitochondrial DNA, high oxidative stress, and high expression of the MFN2 gene could help as a scanner of the mitochondrial function in children with ASD.

A Genetic Score of Predisposition to Low-Grade Inflammation Associated with Obesity May Contribute to Discern Population at Risk for Metabolic Syndrome

Omega-3 rich diets have been shown to improve inflammatory status. However, in an ex vivo system of human blood cells, the efficacy of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) modulating lipid metabolism and cytokine response is attenuated in overweight subjects and shows high inter-individual variability. This suggests that obesity may be exerting a synergistic effect with genetic background disturbing the anti-inflammatory potential of omega-3 long-chain polyunsaturated fatty acids (PUFA). In the present work, a genetic score aiming to explore the risk associated to low grade inflammation and obesity (LGI-Ob) has been elaborated and assessed as a tool to contribute to discern population at risk for metabolic syndrome. Pro-inflammatory gene expression and cytokine production as a response to omega-3 were associated with LGI-Ob score; and lower anti-inflammatory effect of PUFA was observed in subjects with a high genetic score. Furthermore, overweight/obese individuals showed positive correlation of both plasma C-Reactive Protein and triglyceride/HDLc-index with LGI-Ob; and high LGI-Ob score was associated with greater hypertension (p = 0.047), Type 2 diabetes (p = 0.026), and metabolic risk (p = 0.021). The study shows that genetic variation can influence inflammation and omega-3 response, and that the LGI-Ob score could be a useful tool to classify subjects at inflammatory risk and more prone to suffer metabolic syndrome and associated metabolic disturbances.

Prenatal particulate air pollution exposure and cord blood homocysteine in newborns: Results from the ENVIRONAGE birth cohort

INTRODUCTION

Particulate air pollution is probably causally related to increased risk of cardiovascular disease. Plasma homocysteine is an established cardiovascular disease risk factor. Recent studies show that exposure to particulate air pollution is associated with plasma homocysteine levels in adults but no studies on the association between prenatal air pollution and neonatal homocysteine levels exist.

METHODS

In 609 newborns of the ENVIRONAGE (ENVIRonmental influence ON early AGEing) birth cohort, we investigated the association between prenatal particulate matter exposure with a diameter ≤ 2.5 µm (PM_2.5) and cord plasma homocysteine levels, and in a subset (n = 490) we studied the interaction with 11 single nucleotide polymorphism (SNPs) in oxidative stress-related genes (CAT, COMT, GSTP1, SOD2, NQO1 and HFE), through multiple linear regression. PM_2.5 levels were obtained using a high resolution spatial temporal interpolation method. Homocysteine levels were measured by the homocysteine enzymatic assay on a Roche/Hitachi cobas c system. SNPs were assessed on the Biotrove OpenArray SNP genotyping platform.

RESULTS

In multivariable-adjusted models, cord plasma homocysteine levels were 8.1% higher (95% CI: 1.9 to 14.3%; p = 0.01) for each 5 µg/m³ increment in average PM_2.5 exposure during the entire pregnancy. With regard to pregnancy trimesters, there was only an association in the 2^nd trimester: 3.6% (95% CI: 0.9% to 6.4%; p = 0.01). The positive association between PM_2.5 in and homocysteine was (borderline) statistically significantly modified by genetic variants in MnSOD (p interaction = 0.02), GSTP1 (p interaction = 0.07) and the sum score of the 3 studied SNPs in the CAT gene (p interaction=0.09), suggesting oxidative stress as an underlying mechanism of action.

CONCLUSIONS

Exposure to particulate air pollution in utero is associated with higher cord blood homocysteine levels, possibly through generating oxidative stress. Increased air pollution-induced homocysteine levels in early life might predispose for cardiovascular and other diseases later in life.

The Role of Endogenous Neuroprotective Mechanisms in the Prevention of Retinal Ganglion Cells Degeneration

Retinal neurons are not able to undergo spontaneous regeneration in response to damage. A variety of stressors, i.e., UV radiation, high temperature, ischemia, allergens, and others, induce reactive oxygen species production, resulting in consecutive alteration of stress-response gene expression and finally can lead to cell apoptosis. Neurons have developed their own endogenous cellular protective systems. Some of them are preventing cell death and others are allowing functional recovery after injury. The high efficiency of these mechanisms is crucial for cell survival. In this review we focus on the contribution of the most recently studied endogenous neuroprotective factors involved in retinal ganglion cell (RGC) survival, among which, neurotrophic factors and their signaling pathways, processes regulating the redox status, and different pathways regulating cell death are the most important. Additionally, we summarize currently ongoing clinical trials for therapies for RGC degeneration and optic neuropathies, including glaucoma. Knowledge of the endogenous cellular protective mechanisms may help in the development of effective therapies and potential novel therapeutic targets in order to achieve progress in the treatment of retinal and optic nerve diseases.

Gene expression in triple-negative breast cancer in relation to survival

PURPOSE

The identification of biomarkers related to the prognosis of triple-negative breast cancer (TNBC) is critically important for improved understanding of the biology that drives TNBC progression.

METHODS

We evaluated gene expression in total RNA isolated from formalin-fixed paraffin-embedded tumor samples using the NanoString nCounter assay for 469 TNBC cases from the Shanghai Breast Cancer Survival Study. We used Cox regression to quantify Hazard Ratios (HR) and corresponding confidence intervals (CI) for overall survival (OS) and disease-free survival (DFS) in models that included adjustment for breast cancer intrinsic subtype. Of 302 genes in our discovery analysis, 22 were further evaluated in relation to OS among 134 TNBC cases from the Nashville Breast Health Study and the Southern Community Cohort Study; 16 genes were further evaluated in relation to DFS in 335 TNBC cases from four gene expression omnibus datasets. Fixed-effect meta-analysis was used to combine results across data sources.

RESULTS

Twofold higher expression of EOMES (HR 0.90, 95% CI 0.83-0.97), RASGRP1 (HR 0.89, 95% CI 0.82-0.97), and SOD2 (HR 0.80, 95% CI 0.66-0.96) was associated with better OS. Twofold higher expression of EOMES (HR 0.89, 95% CI 0.81-0.97) and RASGRP1 (HR 0.87, 95% CI 0.81-0.95) was also associated with better DFS. On the contrary, a doubling of FA2H (HR 1.14, 95% CI 1.06-1.22) and GSPT1 (HR 1.33, 95% CI 1.14-1.55) expression was associated with shorter DFS.

CONCLUSIONS

We identified five genes (EOMES, FA2H, GSPT1, RASGRP1, and SOD2) that may serve as potential prognostic biomarkers and/or therapeutic targets for TNBC.

Association of the SOD2 Polymorphism (Val16Ala) and SOD Activity with Vaso-occlusive Crisis and Acute Splenic Sequestration in Children with Sickle Cell Anemia

The SOD2 polymorphism Val16Ala T→C influences the antioxidative response. This study investigated the association of the SOD2 polymorphism and superoxide dismutase (SOD) activity with the vaso-occlusive crisis (VOC) and acute splenic sequestration (ASS) in children with sickle cell anemia (SCA). One hundred ninety-five children with SCA aged 1–9 years old were analyzed. The TC and CC genotypes were associated with lower SOD activity compared with the TT genotype (p=0.0321; p=0.0253, respectively). Furthermore, TC and CC were more frequent in patients with VOC or ASS (p=0.0285; p=0.0090, respectively). These results suggest that the SOD2 polymorphism associated with low SOD activity could be a susceptibility factor for the occurrence of VOC and ASS.

Genetics of tardive dyskinesia: Promising leads and ways forward

Tardive dyskinesia (TD) is a potentially irreversible and often debilitating movement disorder secondary to chronic use of dopamine receptor blocking medications. Genetic factors have been implicated in the etiology of TD. We therefore have reviewed the most promising genes associated with TD, including DRD2, DRD3, VMAT2, HSPG2, HTR2A, HTR2C, and SOD2. In addition, we present evidence supporting a role for these genes from preclinical models of TD. The current understanding of the etiogenesis of TD is discussed in the light of the recent approvals of valbenazine and deutetrabenazine, VMAT2 inhibitors, for treating TD.

Association of manganese superoxide dismutase Ala16Val polymorphism in the incidence of acute myocardial infarction in the Egyptians

Background: Oxidative stress has been implicated in various diseases including atherosclerosis; the most common pathologic process underlying acute myocardial infarction (AMI). The manganese superoxide dismutase (MnSOD) antioxidant enzyme affords the major defense against reactive oxygen species (ROS) within the mitochondria. MnSOD Alanine16Valine (A16V) single nucleotide polymorphism (SNP) has been shown to decrease MnSOD detoxification activity. Aim: A case-control study was conducted to investigate the association between MnSOD A16V polymorphism and the incidence of AMI in the Egyptians, investigate the contribution of oxidative stress represented by hexanoyl lysine adduct (HEL), an oxidative stress biomarker, in the pathogenesis of AMI and finally correlate the MnSOD genotypes with HEL serum levels. Methods: A total of 200 Egyptian subjects were recruited for the study; 100 AMI patients and 100 control subjects. Genotypes of the MnSOD A16V polymorphism were determined using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Serum HEL was measured by ELISA. Results: A significant difference in the distribution of the MnSOD A16V genotypes was observed; VV genotype was significantly higher in AMI than controls (p ≤ 0.0001). Also, studying the allele frequencies revealed that Val allele was significantly higher in AMI than controls (p ≤ 0.0001). Serum analysis showed higher levels of HEL in AMI patients (p = 0.0142). Furthermore, HEL levels were found to be significantly higher in VV genotype in AMI (p = 0.0273). Conclusions: Our study suggests that MnSOD A16V polymorphism is associated with increased risk of developing AMI in the Egyptians. Moreover, the VV genotype is associated with higher HEL levels.