The relationship between MnSOD Val16Ala gene polymorphism and the level of serum total antioxidant capacity with the risk of chronic kidney disease in type 2 diabetic patients: a nested case-control study in the Tehran lipid glucose study

Impact of latent toxoplasmosis on pneumonic and non-pneumonic COVID-19 patients with estimation of relevant oxidative stress biomarkers

Susceptibility to COVID-19, the most devastating global pandemic, appears to vary widely across different population groups. Exposure to toxoplasmosis has been proposed as a theory to explain the diversity of these populations. The aim of the present study was to investigate the possible association between latent toxoplasmosis and COVID-19 and its probable correlation with markers of oxidative stress, C-reactive protein (CRP) and ferritin. In a case-control study, blood samples were collected from 91 confirmed (48 non-pneumonic; NP, and 43 pneumonic; P) COVID-19 patients and 45 healthy controls. All participants were tested for IgG anti-Toxoplasma gondii antibodies and oxidative stress markers (nitric oxide [NO], superoxide dismutase [SOD] and reduced glutathione [GSH]), and CRP and serum ferritin levels were determined. In COVID-19 patients, IgG anti-T. gondii antibodies were found in 54% compared to 7% in the control group, with the difference being statistically significant (P ˂ 0.001). However, no significant correlation was found between the severity of COVID-19 and latent T. gondii infection. Latent toxoplasmosis had a strong influence on the risk of COVID-19. NO and SOD levels were significantly increased in COVID-19 patients, while GSH levels decreased significantly in them compared to control subjects (P ˂ 0.001 for both values). CRP and ferritin levels were also significantly elevated in P COVID-19 patients infected with toxoplasmosis. This is the first study to look at the importance of oxidative stress indicators in co-infection between COVID-19 and T. gondii. The high prevalence of latent toxoplasmosis in COVID-19 suggests that T. gondii infection can be considered a strong indicator of the high risk of COVID-19.

Potential Impact of SOD2 (rs4880; p.Val16Ala) Variant with the Susceptibility for Childhood Bronchial Asthma

Oxidative stress is a sophisticated situation that orignates from the accumulation of reactive free radicals within cellular compartments. The antioxidant mechanism of the MnSOD enzyme facilitates the removal of these lethal oxygen species from cellular components. The main goal of this pertained work is to study the contribution of the SOD2 (rs4880; p.Val16Ala) variant to the development of bronchial asthma among children. The study's design was carried out based on a total of 254 participants including 127 asthmatic children (91 atopic and 36 non-atopic) along with 127 unrelated healthy controls. Allelic discrimination analysis was executed using the T-ARMS-PCR protocol. This potential variant conferred a significant association with decreased risk of bronchial asthmatic children under allelic (OR = 0.56, P-value = 0.002), recessive (OR = 0.32, P-value = 0.011), and dominant (OR = 0.51, P-value = 0.040) models. Additionally, atopic and non-atopic asthmatic children indicated a protection against bronchial asthma development under allelic, and dominant models (p-value < 0.05). Our findings suggested that the SOD2*rs4880 variant was correlated with decreased risk of childhood bronchial asthma.

Oxidative Stress and Inflammatory Status in COVID-19 Outpatients: A Health Center-Based Analytical Cross-Sectional Study

The antioxidant system can be critical in reducing exacerbated inflammation in COVID-19. This study compared the antioxidant and inflammatory responses between COVID-19 outpatients and seemingly healthy individuals. This descriptive-analytical cross-sectional study was conducted on 53 COVID-19 outpatients and 53 healthy individuals as controls. The serum concentrations of amyloid A (SAA), total antioxidant capacity (TAC), superoxide dismutase (SOD), and glutathione peroxidase (GPx) were measured and compared between COVID-19 patients and controls using the independent sample t-test before and after controlling for dietary supplement use. A generalized estimating equation (GEE) regression model, limited to COVID-19 patients, was used to evaluate the odds ratios (ORs) and 95% confidence intervals (95% CIs) of disease symptoms on days 1, 7, 14, 21, and 28 after the disease onset. Serum concentrations of SOD (p ≤ 0.001) and GPx (p = 0.001) were significantly higher in COVID-19 patients than in controls before adjustment for dietary supplement use. GPx remained significantly higher among COVID-19 patients than in controls after adjustment for all dietary supplements (p = 0.005). Moreover, serum concentrations of GPx (p = 0.003), SOD (p = 0.022), and TAC (p = 0.028) remained significantly higher among COVID-19 patients than in controls after adjustment for vitamin D supplementation. This study showed higher GPx in COVID-19 outpatients than in controls after adjustment for dietary supplement use. Moreover, elevated SOD, GPx, and TAC concentrations were shown in COVID-19 outpatients compared to controls after adjusting for vitamin D supplementation. These results may provide a useful therapeutic target for treating oxidative stress in COVID-19 disease, which may help ameliorate the pandemic.

Influences of the polymorphisms of the Sod2 gene (rs4880) on the motility and vigor of X- and Y-bearing sperm at different pH values

Superoxide dismutase 2 (SOD2) is an antioxidant enzyme that appears phylogenetically conserved. However, functional Sod2 polymorphisms have been studied, and the specific polymorphisms are related to activity alterations of the SOD2 enzyme. An example of a polymorphism of SOD2 is Val16Ala (rs4880), which has been identified in exon 2 of the human Sod2 gene. This polymorphism is recognized as a single nucleotide polymorphism (SNP) and alters the conformation of SOD2. Additionally, recent studies have shown that the Ala16 Val polymorphism in Sod2 can be related to different pathological diseases. In these terms, the objective of the present study was to evaluate whether the polymorphism of SOD2 in Val16Ala (rs4880) influences the motility and vigor of X- and Y-bearing sperm at different pH values promoting sperm selection. We found that polymorphism rs4880 at normal pH conditions can result in alterations in the activity of superoxide dismutase in the sperm through different assay analyses. Moreover, compelling modulation evidence indicates that this effect could also mediate seminal plasma redox alterations and consequently can play an important role in sperm physiology, fertilization, and postfertilization.

A Study of Associations Between rs9349379 (PHACTR1), rs2891168 (CDKN2B-AS), rs11838776 (COL4A2) and rs4880 (SOD2) Polymorphic Variants and Coronary Artery Disease in Iranian Population

Recent genome-wide association studies reported the association of polymorphic alleles of PHACTR1 (rs9349379 (G)), CDDKN2B-AS1 (rs2891168 (G)), COL4A2 (rs11838776 (A)) and SOD2 (rs4880 (T)) with increased risk of coronary artery disease (CAD). The aim of our study was to assess the association of genetic variants with risk of CAD and its severity and in Southeast Iranian population. This study was examined in 250 CAD-suspected patients (mean age 53.49 ± 6.9 years) and 250 healthy individuals (mean age 52.96 ± 5.9 years). The Taqman SNP genotyping assay was used for genotyping of rs9349379 and rs2891168 variants. Tetra-primer Amplified refractory mutation system-PCR (Tetra-primer ARMS-PCR) was employed for rs11838776 and rs4880. Multivariate logistic regression analyses indicated that the G allele of rs9349379 and rs2891168 were associated with increased risk of CAD. The GG homozygous genotype of rs9349379 and rs2891168 had also been associated with risk of CAD. Additionally, the AG genotype of rs2891168 was associated with CAD. The significance of association of rs2891168 (G, GG, AG) increases with severity of CAD; but the rs9349379 (G, GG) have shown reverse association with severity of CAD. The genetic variants of COL4A2 (rs11838776) and SOD2 (rs4880) reflected no association with CAD in Southeast Iranian population. The findings of this study revealed that the PHACTR1 (rs9349379) and CDKN2B-AS1 (rs2891168) genetic variants might serve as genetic risk factor in CAD.

The association of manganese superoxide dismutase gene polymorphism (Rs4880) with diabetic macular edema in a cohort of type 2 diabetic Egyptian patients

Background

Diabetic retinopathy (DR) and diabetic macular edema (DME) are the leading causes of blindness in patients with diabetes. Increasing numbers of people with diabetes worldwide suggest that DR and DME will continue to be major contributors to vision loss and associated functional impairment for years to come. Oxidative stress is a key participant in the development and progression of diabetes mellitus (DM) and its complications. Antioxidant status can affect vulnerability to oxidative damage, onset and progression of diabetes, and complications of diabetes. Manganese superoxide dismutase (Mn-SOD) is a key mitochondrial enzyme in cell defense against reactive oxygen species (ROS). DR and progression to DME have been associated with polymorphism in the second exon of the Mn-SOD gene at the 16th amino acid (Ala16Val) in the mitochondrial targeting sequence (MTS) of the protein. The study aimed to investigate the association between Ala16Val Mn-SOD gene polymorphism and the susceptibility to DR and DME in type 2 DM (T2DM).

Results

In this study, 150 patients with type 2 DM were enrolled: 100 patients with DR with and without diabetic macular edema (DME) and 50 patients with type 2 diabetes with a duration of 10 years without DR. Ala16Val SNP of the Mn-SOD gene (rs4880) was detected by TaqMan real-time PCR. The results showed that the homozygous polymorphic variant VV between the DME group is significantly higher than the non-DME group (P 0.018) among the DR group.

Conclusion

Mn SOD A16V polymorphism itself may not be associated with DR; meanwhile, it may be implicated in the pathogenesis of DME.

Anthropometric and Biochemical Measures in Bariatric Surgery Candidates: What Is the Role of Inflammatory Potential of Diet?

BACKGROUND

The present study aimed to assess dietary total antioxidant capacity (TAC), dietary phytochemical intake (PI), and dietary inflammatory index (DII) in patients with morbid obesity who are candidates of bariatric surgery and their association with anthropometric and biochemical parameters.

METHODS AND MATERIALS

One hundred seventy patients with morbid obesity who were referred to surgery clinic of Firoozgar Hospital were enrolled in the study. Ideal body weight and adjusted ideal body weight were calculated. The dietary data were collected using a food frequency questionnaire. Anthropometrics and biochemical parameters were assessed. A p-value of <0.05 was considered significant.

RESULTS

The strongest correlations of DII with dietary intakes and anthropometric and biochemical biomarkers were found for iron (p<0.0001). Significant association was also observed for ferritin (p=0.02) and transferrin (p=0.02). In terms of PI, The strongest associations were also found for iron (p<0.0001). Additionally, the value of body mass index (BMI) showed significant correlation with PI (p=0.04). The correlations of dietary total antioxidant indices with dietary intakes and anthropometric and biochemical biomarkers were assessed. Non-significant correlation was found between fasting blood sugar (FBS), hemoglobin A1C (HbA1C), vitamin B12, and vitamin D3 with ORAC index. Significant strong correlation showed for the value of iron in both ferric reducing ability of plasma (FRAP) and Oxygen Radical Absorbance Capacity (ORAC) indices (p<0.0001).

CONCLUSION

We find statistical significance correlation for dietary PI and BMI. The inflammatory and antioxidant properties of diet were not related to biochemical markers associated with obesity. Graphical abstract.

The importance of polymorphisms of regulatory and catalytic antioxidant proteins in chronic kidney disease

Both excessive production of reactive oxygen species (ROS) and impaired antioxidant function are found in patients with chronic kidney disease (CKD). Therefore, individual susceptibility towards CKD can be induced by functional variations of genes encoding antioxidant regulatory (nuclear factor erythroid 2 - related factor 2 (Nrf2)) and catalytic (superoxide dismutase (SOD2) and glutathione peroxidase (GPX1)) proteins. Several types of single nucleotide polymorphisms (SNPs) have been found within the genes encoding these proteins, with Nrf2 (-617C/A), SOD2 (Ala16Val) and GPX1 (Pro198Leu) conferring impaired catalytic activity. The most unexplored gene polymorphism in CKD susceptibility, progression and survival, with only two original studies published, is the Nrf2 (-617C/A) polymorphism. The results of these studies showed that there was no individual impact of this polymorphism on the susceptibility towards end stage renal disease (ESRD) development, oxidative phenotype and mortality. However, Nrf2 had a significant role in ESRD risk and survival, when combined with other antioxidant genes. The results regarding the impact of SOD2 (Ala16Val) and GPX1 (Pro198Leu) polymorphisms on either CKD or ESRD are still inconclusive. Namely, some studies showed that patients having variant SOD2 (Val) or GPX1 (Leu) allele were at increased risk of CKD development and progression, while other studies reported only weak or no association between these polymorphisms and CKD. Surprisingly, the only study that reported an association of GPX1 polymorphism with overall/cardiovascular survival in ESRD patients showed a significant impact of low activity GPX1 (Leu/Leu) genotype on better survival. In this review, we comprehensively and critically appraise the literature on these polymorphisms related to oxidative stress in CKD patients, in order to identify gaps and provide recommendations for further clinical research and translation. New developments in the field of antioxidant polymorphisms in CKD patients could lead to better stratification of CKD patients, based on a prognostic antioxidant gene panel, and provide a more personalised medicine approach for the need of antioxidant therapy in these patients.

Riding the tiger - physiological and pathological effects of superoxide and hydrogen peroxide generated in the mitochondrial matrix

Elevated mitochondrial matrix superoxide and/or hydrogen peroxide concentrations drive a wide range of physiological responses and pathologies. Concentrations of superoxide and hydrogen peroxide in the mitochondrial matrix are set mainly by rates of production, the activities of superoxide dismutase-2 (SOD2) and peroxiredoxin-3 (PRDX3), and by diffusion of hydrogen peroxide to the cytosol. These considerations can be used to generate criteria for assessing whether changes in matrix superoxide or hydrogen peroxide are both necessary and sufficient to drive redox signaling and pathology: is a phenotype affected by suppressing superoxide and hydrogen peroxide production; by manipulating the levels of SOD2, PRDX3 or mitochondria-targeted catalase; and by adding mitochondria-targeted SOD/catalase mimetics or mitochondria-targeted antioxidants? Is the pathology associated with variants in SOD2 and PRDX3 genes? Filtering the large literature on mitochondrial redox signaling using these criteria highlights considerable evidence that mitochondrial superoxide and hydrogen peroxide drive physiological responses involved in cellular stress management, including apoptosis, autophagy, propagation of endoplasmic reticulum stress, cellular senescence, HIF1α signaling, and immune responses. They also affect cell proliferation, migration, differentiation, and the cell cycle. Filtering the huge literature on pathologies highlights strong experimental evidence that 30-40 pathologies may be driven by mitochondrial matrix superoxide or hydrogen peroxide. These can be grouped into overlapping and interacting categories: metabolic, cardiovascular, inflammatory, and neurological diseases; cancer; ischemia/reperfusion injury; aging and its diseases; external insults, and genetic diseases. Understanding the involvement of mitochondrial matrix superoxide and hydrogen peroxide concentrations in these diseases can facilitate the rational development of appropriate therapies.

MnSOD Val16Ala gene polymorphism is associated with REDOX biomarkers in the elderly of primary health care in the city of Porto Alegre

Studies suggest that redox imbalance may be closely associated with pathological aging, contributing effectively to the genesis of several chronic diseases. One of the major defence enzymes against oxidation is Manganese-dependent superoxide dismutase (MnSOD) that acts within the mitochondria. The gene encoding this enzyme is polymorphic and Val16Ala variant is one of its most investigated polymorphisms regarding aging and oxidative stress. This study aimed to verify the occurrence of the MnSOD Val16Ala gene polymorphism association with markers of REDOX metabolism in the elderly of primary health care. A cross-sectional study was performed. The sample consisted of 270 elderly individuals from Family Health Strategy in the city of Porto Alegre, Rio Grande do Sul, Brazil (EMISUS). The following variables were investigated in all subjects: sociodemographic: gender, age, marital status, schooling and income; Anthropometric: weight, height, body mass index (BMI); REDOX markers: advanced oxidation protein products (AOPP), ischemia-modified albumin (IMA), nitric oxide metabolites (NOx), ferric reducing ability of plasma (FRAP) and malondialdehyde (MDA), MnSOD Val16Ala gene polymorphism. Val16Ala gene polymorphism was evaluated by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP). Statistically significant associations were observed in the elderly with AA genotype compared to those with VV genotype, concerning AOPP (p = 0.023) and FRAP (p = 0.027) quartile frequencies, respectively. No statistically significant differences were observed between MnSOD genotypes with MDA, NOx and IMA oxidative markers. Val16Ala gene polymorphism is associated with AOPP and FRAP quartiles frequencies in the elderly of primary health care.

Genes and Eating Preferences, Their Roles in Personalized Nutrition

At present, personalized diets, which take into account consumer genetic characteristics, are growing popular. Nutrigenetics studies the effect of gene variations on metabolism and nutrigenomics, which branches off further and investigates how nutrients and food compounds affect genes. This work deals with the mutations affecting the assimilation of metabolites, contributing to nutrigenetic studies. We searched for the genes responsible for eating preferences which allow for the tailoring of personalized diets. Presently, genetic nutrition is growing in demand, as it contributes to the prevention and/or rehabilitation of non-communicable diseases, both monogenic and polygenic. In this work, we showed single-nucleotide polymorphisms in genes-missense mutations that change the functions of coded proteins, resulting in a particular eating preferences or a disease. We studied the genes influencing food preferences-particularly those responsible for fats and carbohydrates absorption, food intolerance, metabolism of vitamins, taste sensations, oxidation of xenobiotics, eating preferences and food addiction. As a result, 34 genes were identified that affect eating preferences. Significant shortcomings were found in the methods/programs for developing personalized diets that are used today, and the weaknesses were revealed in the development of nutrigenetics (inconsistency of data on SNP genes, ignoring population genetics data, difficult information to understand consumer, etc.). Taking into account all the shortcomings, an approximate model was proposed in the review for selecting an appropriate personalized diet. In the future, it is planned to develop the proposed model for the compilation of individual diets.

The effect of GPx-1 rs1050450 and MnSOD rs4880 polymorphisms on PE susceptibility: a case- control study

Preeclampsia (PE) is a serious pregnancy complication whose etiology is not fully understood. However, previous reports have suggested that oxidative stress and genetic variants may contribute to the development of PE. This study aimed to examine the relationship between the Glutathione peroxidase-1(GPx-1) and Manganese Superoxide dismutase (MnSOD) polymorphisms and preeclampsia (PE) risk in Iranian women. Genotyping of the studied women, including 179 preeclamptic cases and 202 controls, for GPx-1 rs1050450 and MnSOD rs4880 polymorphisms was conducted using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Our results showed a 1.7- to 1.6-fold increased risk of PE in the rs1050450 CT and CT + TT (dominant model) genotypes compared to CC genotype (OR = 1.7, 95%CI 1.1-2.7; P = 0.01 and OR = 1.6, 95%CI 1.1-2.4; P = 0.02; respectively). We also found a marked correlation between TC and CC genotypes of MnSOD rs4880 polymorphism and a 1.9- to 2.3-fold increase risk of PE (OR = 1.9, 95%CI 1.2-2.9; P = 0.005 and OR = 2.3, 95%CI 1-5.1; P = 0.04, respectively). The rs4880 MnSOD polymorphism was correlated with increased risk of PE in the allelic and dominant models (OR = 1.8, 95% CI 1.2-2.5, P = 0.002; OR = 1.9, 95%CI 1.3-3, P = 0.002, respectively). High frequency of TC/CC genotype of MnSOD rs4880 and CT genotypes of rs1050450 polymorphism in PE patients compared to controls showed the contribution of these variants to PE susceptibility.

CNDP1, NOS3, and MnSOD Polymorphisms as Risk Factors for Diabetic Nephropathy among Type 2 Diabetic Patients in Malaysia

Type 2 diabetes mellitus (T2DM) is associated with a high incidence of nephropathy. The aim of this study was to investigate the association of a genetic polymorphism of carnosinase (CNDP1-D18S880 and -rs2346061), endothelial nitric oxide synthase (NOS3-rs1799983), and manganese superoxide dismutase (MnSOD-rs4880) genes with the development of diabetic nephropathy among Malaysian type 2 diabetic patients. A case-control association study was performed using 652 T2DM patients comprising 227 Malays (without nephropathy = 96 and nephropathy = 131), 203 Chinese (without nephropathy = 95 and nephropathy = 108), and 222 Indians (without nephropathy = 136 and nephropathy = 86). DNA sequencing was performed for the D18S880 of CNDP1, while the rest were tested using DNA Sequenom MassARRAY to identify the polymorphisms. DNA was extracted from the secondary blood samples taken from the T2DM patients. The alleles and genotypes were tested using four genetic models, and the best mode of inheritance was chosen based on the least p value. The rs2346061 of CNDP1 was significantly associated with diabetic nephropathy among the Indians only with OR = 1.94 and 95% CI = (1.76–3.20) and fitted best the multiplicative model, while D18S880 was associated among all the three major races with the Malays having the strongest association with OR = 2.46 and 95% CI = (1.48–4.10), Chinese with OR = 2.26 and 95% CI = (1.34–3.83), and Indians with OR = 1.77 and 95% CI = (1.18–2.65) in the genotypic multiplicative model. The best mode of inheritance for both MnSOD and NOS3 was the additive model. For MnSOD-rs4880, the Chinese had OR = 2.8 and 95% CI = (0.53–14.94), Indians had OR = 2.4 and 95% CI = (0.69–2.84), and Malays had OR = 2.16 and 95% CI = (0.54–8.65), while for NOS3-rs1799983, the Indians had the highest risk with OR = 3.16 and 95% CI = (0.52–17.56), followed by the Chinese with OR = 3.55 and 95% CI = (0.36–35.03) and the Malays with OR = 2.89 and 95% CI = (0.29–28.32). The four oxidative stress-related polymorphisms have significant effects on the development of nephropathy in type 2 diabetes patients. The genes may, therefore, be considered as risk factors for Malaysian subjects who are predisposed to T2DM nephropathy.