The MnSOD Ala16Val SNP: relevance to human diseases and interaction with environmental factors

Genetic and Epigenetic Landscape for Drug Development in Polycystic Ovary Syndrome

The treatment of polycystic ovary syndrome (PCOS) faces challenges as all known treatments are merely symptomatic. The US Food and Drug Administration has not approved any drug specifically for treating PCOS. As the significance of genetics and epigenetics rises in drug development, their pivotal insights have greatly enhanced the efficacy and success of drug target discovery and validation, offering promise for guiding the advancement of PCOS treatments. In this context, we outline the genetic and epigenetic advancement in PCOS, which provide novel insights into the pathogenesis of this complex disease. We also delve into the prospective method for harnessing genetic and epigenetic strategies to identify potential drug targets and ensure target safety. Additionally, we shed light on the preliminary evidence and distinctive challenges associated with gene and epigenetic therapies in the context of PCOS.

The Link between Trace Metal Elements and Glucose Metabolism: Evidence from Zinc, Copper, Iron, and Manganese-Mediated Metabolic Regulation

Trace metal elements are of vital importance for fundamental biological processes. They function in various metabolic pathways after the long evolution of living organisms. Glucose is considered to be one of the main sources of biological energy that supports biological activities, and its metabolism is tightly regulated by trace metal elements such as iron, zinc, copper, and manganese. However, there is still a lack of understanding of the regulation of glucose metabolism by trace metal elements. In particular, the underlying mechanism of action remains to be elucidated. In this review, we summarize the current concepts and progress linking trace metal elements and glucose metabolism, particularly for the trace metal elements zinc, copper, manganese, and iron.

Polymorphisms in Genes Encoding VDR, CALCR and Antioxidant Enzymes as Predictors of Bone Tissue Condition in Young, Healthy Men

The aim of the study was to assess significant predictors of bone mineral content (BMC) and bone mineral density (BMD) in a group of young, healthy men at the time of reaching peak bone mass. Regression analyses showed that age, BMI and practicing combat sports and team sports at a competitive level (trained vs. untrained group; TR vs. CON, respectively) were positive predictors of BMD/BMC values at various skeletal sites. In addition, genetic polymorphisms were among the predictors. In the whole population studied, at almost all measured skeletal sites, the SOD2 AG genotype proved to be a negative predictor of BMC, while the VDR FokI GG genotype was a negative predictor of BMD. In contrast, the CALCR AG genotype was a positive predictor of arm BMD. ANOVA analyses showed that, regarding SOD2 polymorphism, the TR group was responsible for the significant intergenotypic differences in BMC that were observed in the whole study population (i.e., lower BMC values of leg, trunk and whole body were observed in AG TR compared to AA TR). On the other hand, higher BMC at L1-L4 was observed in the SOD2 GG genotype of the TR group compared to in the same genotype of the CON group. For the FokI polymorphism, BMD at L1-L4 was higher in AG TR than in AG CON. In turn, the CALCR AA genotype in the TR group had higher arm BMD compared to the same genotype in the CON group. In conclusion, SOD2, VDR FokI and CALCR polymorphisms seem to affect the association of BMC/BMD values with training status. In general, at least within the VDR FokI and CALCR polymorphisms, less favorable genotypes in terms of BMD (i.e., FokI AG and CALCR AA) appear to be associated with a greater BMD response to sports training. This suggests that, in healthy men during the period of bone mass formation, sports training (combat and team sports) may attenuate the negative impact of genetic factors on bone tissue condition, possibly reducing the risk of osteoporosis in later age.

Total impact of oxidative stress genes on cardiovascular events-a 7-year follow-up study

Cardiovascular (CV) events are the number one cause of lifetime disability and deaths worldwide. It is well known that traditional risk factors do not fully correlate with clinical outcomes; therefore, searching for other markers that would explain CV events' occurrence seems essential. Of importance, one of the main factors at the origin of CV events is oxidative stress, causing inflammation and atherosclerotic plaque instability. Therefore, the present study was conducted to evaluate eight carefully selected genetic polymorphisms related to oxidative stress as risk modifiers for CV events. A cohort of 1020 patients with coronary atherosclerosis was analysed in a 7-year follow-up observational study. The following end points were assessed: CV death, myocardial infarction (MI) and a combined end point of CV death/MI/stroke. Our results show that single polymorphisms are not significant cardiovascular disease risk factors, but genetic risk score (GRS), defined as the accumulation of our eight studied polymorphisms, was significantly associated with the three. Specifically, low GRS was associated with a higher risk of CV death, MI and CV death/MI/stroke. In conclusion, when regarding CV events, GRS investigated here can become clinically meaningful and undoubtedly adds to the knowledge in stratifying the risk of CV events.

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.

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.

Association of CYBA C242T and superoxide dismutase 2 A16V genetic variants with preeclampsia

OBJECTIVE

To investigate the relationship between NADPH oxidase p22phox subunit (CYBA; C242T) and superoxide dismutase 2 (SOD2; A16V) polymorphisms and the risk of preeclampsia (PE) in Chinese women.

METHODS

This case-control study included 325 patients with PE and 1294 controls. The genotypes were determined by polymerase chain reaction-restriction fragments length polymorphism method. Clinical, metabolic, and oxidative stress parameters were analyzed.

RESULTS

Participants with T allele of the CYBA C242T polymorphism had a decreased risk of PE (OR = 0.62, 95% CI: 0.42-0.92, P = 0.016) and those with the A allele of the SOD2 A16V polymorphism had increased risk of PE (OR = 1.44, 95% CI: 1.09-1.89, P = 0.010). The coexistence of the SOD2 AA + AV genotypes and the CYBA CC genotype further increased the risk of PE (OR = 2.32, 95% CI: 1.31-4.10, P = 0.003) when the CT + TT/VV combined genotype was the reference category.

CONCLUSION

The T allele of the CYBA C242T polymorphism is related to a decreased risk of PE, while the A allele of the SOD2 A16V polymorphism and its combination with the CYBA CC genotype are associated with an increased risk of PE in Chinese women.

Associations between prenatal exposure to cadmium and lead with neural tube defect risks are modified by single-nucleotide polymorphisms of fetal MTHFR and SOD2: a case-control study

BACKGROUND

Prenatal exposure to heavy metals is implicated in the etiology of birth defects. We investigated whether concentrations of cadmium (Cd) and lead (Pb) in umbilical cord tissue are associated with risk for neural tube defects (NTDs) and whether selected genetic variants of the fetus modify their associations.

METHODS

This study included 166 cases of NTD fetuses/newborns and 166 newborns without congenital malformations. Umbilical cord tissue was collected at birth or elective pregnancy termination. Cd and Pb concentrations were assessed by inductively coupled plasma-mass spectrometry, and 20 single-nucleotide polymorphisms (SNPs) in 9 genes were genotyped. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to estimate the risk for NTDs in association with metal concentrations or genotype using logistic regression. Multiplicative-scale interactions between the metals and genotypes on NTD risk were assessed with logistic regression, and additive-scale interactions were estimated with a non-linear mixed effects model.

RESULTS

Higher concentrations of Cd were observed in the NTD group than in the control group, but no difference was found for Pb. Concentrations of Cd above the median level showed a risk effect, while the association between Pb and NTD risk was not significant in univariate analyses. The association of Cd was attenuated after adjusting for periconceptional folic acid supplementation. Fetuses with the AG and GG genotypes of rs4880 in SOD2 (superoxide dismutase 2) tended to have a lower risk, but fetuses with the CT and TT genotypes of rs1801133 in MTHFR (5,10-methylenetetrahydrofolatereductase) have a higher risk for NTDs when compared to their respective wild-type. rs4880 and Cd exhibited a multiplicative-scale interaction on NTD risk: the association between higher Cd and the risk for NTDs was increased by over fourfold in fetuses carrying the G allele [OR 4.43 (1.30-15.07)] compared to fetuses with the wild-type genotype. rs1801133 and Cd exposure showed an additive interaction, with a significant relative excess risk of interaction [RERI 0.64 (0.02-1.25)].

CONCLUSIONS

Prenatal exposure to Cd may be a risk factor for NTDs, and the risk effect may be enhanced in fetuses who carry the G allele of rs4880 in SOD2 and T allele of rs1801133 in MTHFR.

Association of Val16Ala Polymorphism of Manganese Superoxide Dismutase (MnSOD) with Food Intake and Cardiometabolic Risk Factors in the Elderly in Primary Care in Porto Alegre

BACKGROUND

The aging process causes physiological changes on its own. The combination of an unhealthy lifestyle with the presence of genetic polymorphisms, such as the Val16Ala of the antioxidant enzyme manganese-dependent superoxide dismutase (MnSOD) may contribute to a greater occurrence of cardiometabolic risk factors.

OBJECTIVE

This study aimed to verify the association of Val16Ala-MnSOD polymorphism with food intake, caloric expenditure, and cardiometabolic risk factors in the elderly.

METHODS

A cross-sectional study with a sample size of 270 elderly individuals assisted in primary health care in the city of Porto Alegre, RS, Brazil. Val16Ala polymorphism, glucose, lipid profile, insulin, HOMA-IR, blood pressure, waist circumference, PCR-us, IL-6, food consumption, and caloric expenditure were evaluated.

RESULTS

The average age of the elderly was 68.6 ± 7.6 years. There were statistically significant differences regarding the consumption of two or more servings of fruits and vegetables daily between the elderly VV versus AV (P=0.017). There were also statistically significant differences regarding the consumption of two or more daily servings of legumes and eggs between the elderly AA versus VV (P=0.002). The median of insulin was higher in the elderly AA versus AV (P=0.025) and the median of HOMA-IR was higher in the elderly VV versus AV (P=0.029). AA elderly individuals had higher means of high-density lipoprotein (HDL-c) compared to AV (P=0.029).

CONCLUSION

The results suggest that Val16Ala -MnSOD polymorphism is associated with the consumption of fruits, vegetables, legumes, and eggs, as well as with cardiometabolic risk factors in the elderly.

Superoxide-anion triggers impairments of immune efficiency and stress response behaviors of Eisenia fetida earthworms

Superoxide-hydrogen peroxide (S-HP), triggered by Val16Ala-SOD2 human polymorphism, may influence the risk of depression. Therefore, it is plausible that higher basal S-anion levels and chronic inflammatory states associated with the VV-SOD2 genotype can negatively modulate the stress response associated with resilience in various species, from primitive species to humans. To test this hypothesis, Eisenia fetida earthworms were exposed for 24 h to 30 nM rotenone, which causes mitochondrial dysfunction by generating high S-anion levels (known as the "VV-like phenotype"), and 10 μM porphyrin, a SOD2-like compound, which generates elevated HP levels (known as the "AA-like phenotype"). The results suggested that both S-anion and HP acted as signaling molecules, differentially altering the immune function and acute hydric stressful response. Although the AA-like phenotype improved the immune and stress response efficiencies, the VV-like phenotype showed a downregulated expression of the toll-like receptor (EaTLR, JX898685) and antimicrobial peptide (AMP) (AF060552) genes, which triggered the impairment of encapsulation and earthworms extracellular trap (EET) processes used by earthworms to trap and destroy microorganisms. When exposed to adverse environments and dangerous hydric stress, VV-like earthworms exhibited an impulsive behavior and failed to quickly identify and migrate to a protected environment, unlike control earthworms and AA-like earthworms. All results corroborated that the S-anion imbalance could concomitantly induce alterations in immune function and stress behavior related to earthworm survival. From a human perspective, this information may corroborate the potential specific role of superoxide anion in the modulation of the stress response, resilience, and risk of depression.

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.

Trace element profile and incidence of type 2 diabetes, cardiovascular disease and colorectal cancer: results from the EPIC-Potsdam cohort study

PURPOSE

We aimed to examine the prospective association between manganese, iron, copper, zinc, iodine, selenium, selenoprotein P, free zinc, and their interplay, with incident type 2 diabetes (T2D), cardiovascular disease (CVD) and colorectal cancer (CRC).

METHODS

Serum trace element (TE) concentrations were measured in a case-cohort study embedded within the EPIC-Potsdam cohort, consisting of a random sub-cohort (n = 2500) and incident cases of T2D (n = 705), CVD (n = 414), and CRC (n = 219). TE patterns were investigated using principal component analysis. Cox proportional hazard models were fitted to examine the association between TEs with T2D, CVD and CRC incidence.

RESULTS

Higher manganese, zinc, iodine and selenium were associated with an increased risk of developing T2D (HR Q5 vs Q1: 1.56, 1.09-2.22; HR per SD, 95% CI 1.18, 1.05-1.33; 1.09, 1.01-1.17; 1.19, 1.06-1.34, respectively). Regarding CVD, manganese, copper and copper-to-zinc ratio were associated with an increased risk (HR per SD, 95% CI 1.13, 1.00-1.29; 1.22, 1.02-1.44; 1.18, 1.02-1.37, respectively). The opposite was observed for higher selenium-to-copper ratio (HR Q5 vs Q1, 95% CI 0.60, 0.39-0.93). Higher copper and zinc were associated with increasing risk of developing CRC (HR per SD, 95% CI 1.29, 1.05-1.59 and 1.14, 1.00-1.30, respectively). Selenium, selenoprotein P and selenium-to-copper-ratio were associated to decreased risk (HR per SD, 95% CI 0.82, 0.69-0.98; 0.81, 0.72-0.93; 0.77, 0.65-0.92, respectively). Two TE patterns were identified: manganese-iron-zinc and copper-iodine-selenium.

CONCLUSION

Different TEs were associated with the risk of developing T2D, CVD and CRC. The contrasting associations found for selenium with T2D and CRC point towards differential disease-related pathways.

Association of MnSOD gene polymorphism with susceptibility to Kawasaki disease in Chinese children

BACKGROUND

Kawasaki disease is a type of acute febrile rash disease that is common in children and is characterised by primary lesions of systemic middle and small vasculitis, which can lead to coronary artery lesions. Manganese superoxide dismutase (MnSOD), one of the most important antioxidases in the human body, plays a key role in maintaining the balance of free radicals in the human body. Two single-nucleotide polymorphisms (SNPS) (rs4880 and rs5746136) in the MnSOD gene were related to oxidative stress disease. The purpose of this study is to explore the possible relationship between MnSOD gene polymorphisms and Kawasaki disease susceptibility.

METHODS

This study included 100 Kawasaki disease children and 102 healthy children. Two single-nucleotide polymorphisms (rs4880 and rs5746136) were detected by polymerase chain reaction sequence-based typing.

RESULTS

There was a significant difference in both the genotype frequency (χ2 = 10.805, p = 0.005) and the allele frequency (χ2 = 7.948, p = 0.005) of rs5746136 between the Kawasaki disease group and the control group. Children with the A allele had a 0.558 times lower risk of Kawasaki disease than those without the A allele (χ2 = 7.948, p = 0.005, odds ratio = 0.558, 95% confidence interval = 0.371-0.838). There was no significant difference in the genotype and gene frequencies of rs5746136 between the Kawasaki disease-coronary artery lesion and Kawasaki disease-without coronary artery lesion groups (p > 0.05), and there was no significant difference in the rs4880 genotype and allele frequencies between the Kawasaki disease and healthy control groups or between the Kawasaki disease-coronary artery lesion and Kawasaki disease-without coronary artery lesions groups (p > 0.05).

CONCLUSION

This study provides evidence supporting an association between MnSOD gene polymorphisms and susceptibility to Kawasaki disease. The genotype AA and the allele A of the MnSOD gene locus rs5746136 were risk factors for Kawasaki disease.

Genetic polymorphisms associated with polycystic ovary syndrome among Iranian women

Polycystic ovary syndrome (PCOS) involves abnormalities in ovarian, reproductive, and metabolic systems. Genetic polymorphisms associated with individual differences and variations might be related to complex disorders with unknown causes, including PCOS. Several leading genetic markers with known cellular functions have been identified among Iranian women presenting with PCOS. In particular, the existing evidence shows a significant relationship between PCOS and the following genetic polymorphisms: rs2275913 (interleukin-17A), rs9927163 (interleukin-32), Pro12Ala (peroxisome proliferator-activated receptor-γ), rs17173608 (chemerin), rs2236242 (vaspin), ApaI (vitamin D receptor), and rs7895833 (sirtuin 1). In addition, a higher risk of PCOS is associated with the rs2910164 (microRNA 146a), rs2241766 (adiponectin), -34 T/C (cytochrome 17), and rs1800682 (Fas) polymorphisms. Furthermore, protective effects against PCOS have been reported for the A4223C polymorphism of adenosine deaminase 1. Overall, the available data indicate that Iranian women with PCOS have a higher prevalence of polymorphisms in inflammation- and metabolism-related genes, but not in insulin-related genes. More extensive studies are needed to identify the ethnicity-related genetic associations in PCOS.

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.

Nutrigenetics of antioxidant enzymes and micronutrient needs in the context of viral infections

Sustaining adequate nutritional needs of a population is a challenging task in normal times and a priority in times of crisis. There is no 'one-size-fits-all' solution that addresses nutrition. In relevance to the COVID-19 (coronavirus disease 2019) pandemic crisis, viral infections in general and RNA viruses in particular are known to induce and promote oxidative stress, consequently increasing the body's demand for micronutrients, especially those related to antioxidant enzymic systems, thus draining the body of micronutrients, and so hindering the human body's ability to cope optimally with oxidative stress. Common polymorphisms in major antioxidant enzymes, with world population minor allele frequencies ranging from 0·5 to 50 %, are related to altered enzymic function, with substantial potential effects on the body's ability to cope with viral infection-induced oxidative stress. In this review we highlight common SNP of the major antioxidant enzymes relevant to nutritional components in the context of viral infections, namely: superoxide dismutases, glutathione peroxidases and catalase. We delineate functional polymorphisms in several human antioxidant enzymes that require, especially during a viral crisis, adequate and potentially additional nutritional support to cope with the pathological consequences of disease. Thus, in face of the COVID-19 pandemic, nutrition should be tightly monitored and possibly supplemented, with special attention to those carrying common polymorphisms in antioxidant enzymes.

Association of Genes Related to Oxidative Stress with the Extent of Coronary Atherosclerosis

Oxidative stress is believed to play a critical role in atherosclerosis initiation and progression. In line with this, in a group of 1099 subjects, we determined eight single nucleotide polymorphisms (SNPs) related to oxidative stress (PON1 c.575A>G, MPO c.−463G>A, SOD2 c.47T>C, GCLM c.−590C>T, NOS3 c.894G>T, NOS3 c.−786T>C, CYBA c.214C>T, and CYBA c.−932A>G) and assessed the extent of atherosclerosis in coronary arteries based on Gensini score. An increased risk of having a Gensini score in the higher half of the distribution was observed for the PON1 c.575G allele (odds ratio (OR) = 1.27, 95% confidence interval (CI): 1.004–1.617, p = 0.046). Next, the genetic risk score (GRS) for the additive effect of the total number of pro-oxidative alleles was assessed. We noted an increase in the risk of having a Gensini score above the median with the maximum number of risk alleles (OR = 2.47, 95% CI: 1.19–5.23, p = 0.014). A univariate Spearman’s test revealed significant correlation between the total number of pro-oxidant alleles (GRS) and the Gensini score (ρ = 0.068, p = 0.03). In conclusion, the PON1 c.575A>G variant and the high number of risk alleles (GRS) were independent risk factors for a high Gensini score. We suggest, however, that GRS might occur as a more valuable component in adding a predictive value to the genetic background of atherosclerosis.

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.

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.

Association of SOD2 A16V and PON2 S311C polymorphisms with polycystic ovary syndrome in Chinese women

PURPOSE

To investigate the relationship between superoxide dismutase 2 (SOD2) A16V and paraoxonase 2 (PON2) S311C gene variants and the risk of polycystic ovary syndrome (PCOS) and evaluate the effects of the genotypes on clinical, hormonal, metabolic and oxidative stress indexes in Chinese women.

METHODS

This is a cross-sectional study of 932 patients with PCOS and 745 control women. For the clinical and metabolic association study of genotypes, 631 patients and 492 controls were included after excluding the subjects with interferential factors. Genotypes were determined by polymerase chain reaction (PCR) and restriction fragment length polymorphism analysis. Serum total oxidant status, total antioxidant capacity (T-AOC), oxidative stress index and malondialdehyde (MDA) levels, and clinical and metabolic parameters were also analyzed.

RESULTS

The prevalence of the A allele of SOD2 A16V polymorphism was significantly greater in patients with PCOS than in control subjects. Genotype (AA + AV) remained a significant predictor for PCOS in prognostic models including age, body mass index, insulin resistance index, high-density lipoprotein (HDL), low-density lipoprotein (LDL), and triglycerides (TGs) as covariates. Patients carrying the A allele had significantly higher serum luteinizing hormone (LH) levels, and the ratio of LH to follicle-stimulating hormone compared with patients with the VV genotype. We also showed that patients carrying the C allele of the PON2 S311C polymorphism had lower T-AOC compared with patients carrying the SS genotype. However, no significant differences were observed in the frequencies of the S311C genotypes and alleles of the PON2 gene between PCOS and control groups.

CONCLUSION

The SOD2 A16V, but not PON2 S311C, polymorphism may be one of the genetic determinants for PCOS in Chinese women.

Disease-Associated Genetic Variation in Human Mitochondrial Protein Import

Mitochondrial dysfunction has consequences not only for cellular energy output but also for cellular signaling pathways. Mitochondrial dysfunction, often based on inherited gene variants, plays a role in devastating human conditions such as mitochondrial neuropathies, myopathies, cardiovascular disorders, and Parkinson and Alzheimer diseases. Of the proteins essential for mitochondrial function, more than 98% are encoded in the cell nucleus, translated in the cytoplasm, sorted based on the presence of encoded mitochondrial targeting sequences (MTSs), and imported to specific mitochondrial sub-compartments based on the integrated activity of a series of mitochondrial translocases, proteinases, and chaperones. This import process is typically dynamic; as cellular homeostasis is coordinated through communication between the mitochondria and the nucleus, many of the adaptive responses to stress depend on modulation of mitochondrial import. We here describe an emerging class of disease-linked gene variants that are found to impact the mitochondrial import machinery itself or to affect the proteins during their import into mitochondria. As a whole, this class of rare defects highlights the importance of correct trafficking of mitochondrial proteins in the cell and the potential implications of failed targeting on metabolism and energy production. The existence of this variant class could have importance beyond rare neuromuscular disorders, given an increasing body of evidence suggesting that aberrant mitochondrial function may impact cancer risk and therapeutic response.

Superoxide Dismutase Levels and Polymorphism (Ala16val) In Tuberculosis Patients with Diabetes Mellitus in Medan City

BACKGROUND

Infectious diseases and metabolic disorders would result in oxidative stress in cells. Superoxide dismutase (SOD) is an antioxidant present inside cells that acts against oxidative stress. SOD gene polymorphism can affect the activity and levels of SOD.

AIM

This study aimed to analyse SOD levels and polymorphism of gene (ala16val) that regulated SOD in tuberculosis patients with diabetes mellitus in Medan city.

METHODS

A total of 40 tuberculosis patients with diabetes mellitus and 40 healthy subjects participated in the study. The levels of SOD were measured using enzyme-linked immunosorbent assay (ELISA). Analysis of SOD gene polymorphism (ala16val) was done using polymerase chain reaction-restriction fragment lengths polymorphisms (PCR-RFLP) with BsaW1 as the restriction enzyme. The statistical significance was determined using the Mann Whitney test, Fisher's exact test, and Kruskal Wallis test (p < 0.05).

RESULTS

The SOD levels of tuberculosis patients with diabetes mellitus were lower than those of the healthy subjects (102.474 ± 36.07 U/L vs 294.543 ± 58.75 U/L, p < 0.05). Patients of tuberculosis with diabetes mellitus tend to have more value/Val genotypes than the healthy group (57.5% vs 50%, p > 0.05). There was no association between SOD levels and SOD gene polymorphism (ala16val) in tuberculosis patients with diabetes mellitus.

CONCLUSION

In this study, there was an association between the levels of SOD and tuberculosis patients with diabetes mellitus, but not for the SOD gene polymorphism (ala16val). The SOD gene polymorphism (ala16val) was not the key role to influence the SOD levels in tuberculosis patients with diabetes mellitus in Medan city.

Toxicant-mediated redox control of proteostasis in neurodegeneration

Disruption in redox signaling and control of cellular processes has emerged as a key player in many pathologies including neurodegeneration. As protein aggregations are a common hallmark of several neuronal pathologies, a firm understanding of the interplay between redox signaling, oxidative and free radical stress, and proteinopathies is required to sort out the complex mechanisms in these diseases. Fortunately, models of toxicant-induced neurodegeneration can be utilized to evaluate and report mechanistic alterations in the proteostasis network (PN). The epidemiological links between environmental toxicants and neurological disease gives further credence into characterizing the toxicant-mediated PN disruptions observed in these conditions. Reviewed here are examples of mechanistic interaction between oxidative or free radical stress and PN alterations. Additionally, investigations into toxicant-mediated PN disruptions, specifically focusing on environmental metals and pesticides, are discussed. Finally, we emphasize the need to distinguish whether the presence of protein aggregations are contributory to phenotypes related to neurodegeneration, or if they are a byproduct of PN deficiencies.

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.

Association of GPx1 P198L and CAT C-262T Genetic Variations With Polycystic Ovary Syndrome in Chinese Women

Background: Oxidative stress plays an important role in the pathogenesis of polycystic ovary syndrome (PCOS). Glutathione peroxidase 1 (GPx1) and catalase (CAT) are the major intracellular antioxidant enzymes that can detoxify hydrogen peroxide into water, preventing cellular injury from reactive oxygen species. The aim of the present study was to investigate the association of GPx1 P198L (Pro198Leu, C559T, rs1050450) and CAT C-262T (rs1001179) genetic polymorphisms with the risk of PCOS and evaluate the effects of the genotypes on clinical, hormonal, metabolic and oxidative stress parameters in Chinese women. Methods: This is a case-control study of 654 patients with PCOS and 535 controls. The GPx1 P198L, CAT C-262T, and superoxide dismutase 2 (SOD2) A16V genotypes were determined by polymerase chain reaction amplification and restriction analysis. Clinical, hormonal, metabolic and oxidative stress parameters were also analyzed. Results: The frequencies of the PL + LL genotype (14.1 vs. 8.4%) and L allele (7.3 vs. 4.4%) of GPx1 P198L polymorphism were significantly higher in patients with PCOS than in control subjects. Genotype (PL + LL) remained a significant predictor for PCOS in prognostic models including age, body mass index (BMI), insulin resistance index, total cholesterol, triglycerides, high-density lipoprotein-cholesterol, and low-density lipoprotein-cholesterol as covariates (OR = 2.105, 95%CI: 1.330-3.331, P = 0.001). Patients carrying the L allele had relatively high average ovarian volume, waist circumference, and malondialdehyde levels (P < 0.07) compared with patients with the PP genotype. We also demonstrated that the subjects with both GPx1 L and SOD2 A alleles further increase the risk of PCOS compared with the individuals carrying the PP/VV genotype after adjusting for age and BMI (OR = 5.774, 95%CI: 2.243-14.863, P < 0.001). However, no significant differences were observed in the frequencies of the CAT C-262T genotypes and alleles between PCOS and control groups. Conclusions: The GPx1 P198L, but not CAT C-262T, genetic polymorphism is associated with the risk of PCOS in Chinese women.

Clinical variables and ethnicity may influenced by polymorphism of CAT -262C/T and MnSOD 47C/T antioxidant enzymes in Algerian type1 diabetes without complications

The latest studies in Algeria show that the frequency of type 1 diabetes (T1D) without complications is lower than that with complications and represents a significant burden in terms of cost and treatment. For this reason, we are interested in uncomplicated type1 diabetes and risk factors that are related to polymorphisms of antioxidant enzymes in order to prevent its complications. A total of 260 blood samples of young Algerian adults were examined. The genotypic analysis of Catalase gene (CAT -262C/T, rs1001179) and the superoxide dismutase gene (MnSOD 47C/T, rs4880) was performed by real-time PCR using TaqMan technology. The genotypic distribution of the CAT -262C/T promoter gene's polymorphism showed a significant difference between control and T1D patients for the CC genotype (p = 0.009; OR = 0.30) and for the T allele (p = 0.002; OR = 2.82). In addition, the genotypic distribution of the MnSOD 47C/T gene showed an association with T1D for the CT genotype (p = 0.040; OR = 2.37). Our results revealed that polymorphisms of CAT and MnSOD may be associated with physiopathology causing the onset of T1D. Our data, suggest that the genotypic frequencies of these SNPs appear to be influenced by clinical variables and by the Arab-Berber ethnic origin of the Algerian population.

Association between MnSOD Val16Ala Polymorphism and Cancer Risk: Evidence from 33,098 Cases and 37,831 Controls

Manganese superoxide dismutase (MnSOD) plays a critical role in the defense against reactive oxygen species. The association between MnSOD Val16Ala polymorphism and cancer risk has been widely studied, but the results are contradictory. To obtain more precision on the association, we performed the current meta-analysis with 33,098 cases and 37,831 controls from 88 studies retrieved from PubMed, Embase, Chinese National Knowledge Infrastructure (CNKI), and Wanfang databases. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of association. We found that the polymorphism was associated with an increased overall cancer risk (homozygous: OR = 1.09, 95% CI = 1.00-1.19; heterozygous: OR = 1.07, 95% CI = 1.02-1.12; dominant: OR = 1.08, 95% CI = 1.02-1.14; and allele comparison: OR = 1.06, 95% CI = 1.02-1.11). Stratification analysis further showed an increased risk for prostate cancer, Asians, Caucasians, population-based studies, hospital-based studies, low quality and high quality studies. However, the increased risk for MnSOD Val16Ala polymorphism among Asians needs further validation based on the false-positive report probability (FPRP) test. To summarize, this meta-analysis suggests that the MnSOD Val16Ala polymorphism is associated with significantly increased cancer risk, which needs further validation in single large studies.

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

Background

Several studies have shown significant associations between manganese superoxide dismutase (MnSOD) Val16Ala polymorphism and diabetic complications, but this association has not been explored in relation with chronic kidney disease (CKD) in Type 2 diabetes mellitus (T2DM) patients. Total antioxidant capacity (TAC) level changes in diabetic condition and may play important role in onset or progression of the disease and its complications. The present study investigated the association of MnSOD Val16Ala polymorphism and serum TAC with the risk of CKD in T2DM patients.

Methods

This nested case-control study included 280 type 2 diabetic patients with CKD and 280 age, sex and diabetes duration-matched control subjects selected from the participants of the Tehran Lipid and Glucose Study. MnSOD val16Ala (rs4880) SNP was genotyped by the Tetra-Primer ARMS-polymerase chain reaction analysis. Serum TAC was measured using ferric-reducing antioxidant power assay. Statistical analysis was performed using STATA statistical package v.12.0 or SPSS (Version 22.0).

Results

The Ala allele of the MnSOD Val16Ala polymorphism was associated with a lower risk of CKD (odds ratio (OR), 0.55; 95% confidence interval (CI), 0.36–0.84; P = 0.006). Median serum TAC in CKD group was 920 μmol/L and was significantly lower (p < 0.001) compared to the control group (1045 μmol/L). Using an adjusted conditional logistic regression, we didn’t observe any significant interaction between MnSOD Val16Ala SNP with quartiles of serum TAC in relation to CKD.

Conclusion

A significant association was found between the MnSOD Val16Ala polymorphism and CKD, but this association is not affected by serum TAC level in T2DM patients.

The Essential Element Manganese, Oxidative Stress, and Metabolic Diseases: Links and Interactions

Manganese (Mn) is an essential element that is involved in the synthesis and activation of many enzymes and in the regulation of the metabolism of glucose and lipids in humans. In addition, Mn is one of the required components for Mn superoxide dismutase (MnSOD) that is mainly responsible for scavenging reactive oxygen species (ROS) in mitochondrial oxidative stress. Both Mn deficiency and intoxication are associated with adverse metabolic and neuropsychiatric effects. Over the past few decades, the prevalence of metabolic diseases, including type 2 diabetes mellitus (T2MD), obesity, insulin resistance, atherosclerosis, hyperlipidemia, nonalcoholic fatty liver disease (NAFLD), and hepatic steatosis, has increased dramatically. Previous studies have found that ROS generation, oxidative stress, and inflammation are critical for the pathogenesis of metabolic diseases. In addition, deficiency in dietary Mn as well as excessive Mn exposure could increase ROS generation and result in further oxidative stress. However, the relationship between Mn and metabolic diseases is not clear. In this review, we provide insights into the role Mn plays in the prevention and development of metabolic diseases.

Genetic polymorphisms of antioxidant enzymes CAT and SOD affect the outcome of clinical, biochemical, and anthropometric variables in people with obesity under a dietary intervention

BACKGROUND

Genetic polymorphisms of antioxidant enzymes CAT, GPX, and SOD are involved in the etiology of obesity and its principal comorbidities. The aim of the present study was to analyze the effect of aforementioned SNPs over the output of several variables in people with obesity after a nutritional intervention. The study included 92 Mexican women, which received a dietary intervention by 3 months. Participants were genotyped and stratified into two groups: (1) carriers; mutated homozygous plus heterozygous (CR) and (2) homozygous wild type (WT). A comparison between CR and WT was done in clinical (CV), biochemical (BV), and anthropometric variables (AV), at the beginning and at the end of the intervention.

RESULTS

Participants (n = 92) showed statistically significant differences (p < 0.05) at the end of the nutritional intervention in several CV, BV, and AV. However, two kinds of responses were observed after genotyping participants: (A) CR and WT showed statistically significant differences (p < 0.05) in several CV, BV, and AV for the SNPs 599C>T GPX1 (rs1050450), - 251A>G SOD1 (rs2070424), and - 262C>T CAT (rs1001179). (B) Only CR showed statistically changes (p < 0.05) in several CV, BV, and AV for the SNPs - 21A>T CAT (rs7943316) and 47C>T SOD2 (rs4880). The dietary intervention effect was statistically significantly between the polymorphisms of 47C>T SOD2 and BMI, SBP, TBARS, total cholesterol, and C-LCL (p < 0.05) and between the polymorphisms of - 21A>T CAT (rs7943316) and SBP, DBP, total cholesterol, and atherogenic index (p < 0.05).

CONCLUSION

People with obesity display different response in several CV, BV, and AV after a nutritional intervention, depending on the antioxidant genetic background of SOD and CAT enzymes.

SOD2 gene polymorphism may modulate biochemical responses to a 12-week swimming training

The aim of the study was to analyze the effect of SOD2 Val16Ala polymorphism on blood biochemical response to chronic swimming training. Healthy men (students of physical education) participated in a swimming training program (ST group) or served as a control group (CON group). The swimming training program lasted 12 weeks (1.5h per day; 4 days per week). Fasting blood samples were obtained prior to (pre) and after (post) a 12-week study period, to measure the biomarkers of oxidative stress, muscle damage and lipid profile. No significant changes in the study parameters were documented in CON group after a 12-week study period, either overall or among carriers of specific SOD2 Val16Ala genotypes. In ST group, post-training decrease in serum lipid hydroperoxides (p < 0.05) and creatine kinase activity (p < 0.05) was associated with Ala/Ala genotype of SOD2 Val16Ala polymorphism. In turn, the increase in serum activity of superoxide dismutase (p < 0.05) was associated with Val carriers, and Val/Val genotype additionally predisposed to the post-training increase in total glutathione level in whole blood (p < 0.05). Moreover, in ST group, a 12-week swimming training program induced an increase in serum concentration of total cholesterol (p < 0.05), which resulted from an increase in both high density (p < 0.05) and low density lipoprotein cholesterol (p < 0.05). The change in high density lipoprotein cholesterol level was irrespective of the genotype. Also, a tendency to post-training increase in both total and low density lipoprotein cholesterol was observed in all three genotypes, although these changes were significant solely in Ala/Val genotype carriers (p < 0.05). In conclusion, 12-week swimming training induces changes in oxidative stress and muscle damage parameters, as well as in lipid profile. These changes seem to be associated with the presence of SOD2 Val16Ala polymorphism. Presence of Ala allele, especially as homozygote, is associated with some beneficial post-training changes, such as a decrease in lipid peroxidation and less pronounced muscle damage. In turn, the influence of SOD2 Val16Ala polymorphism on the changes in lipid profile in response to chronic swimming training should be verified in further study.

Xanthine-Catechin Mixture Enhances Lithium-Induced Anti-Inflammatory Response in Activated Macrophages In Vitro

Lithium (Li) is a chemical element used for treating and preventing bipolar disorder (BD) and exerts positive effects such as anti-inflammatory effects as well as undesirable side effects. These effects of Li can be influenced by interaction with some nutritional elements. Therefore, we investigated the potential effects of xanthine (caffeine and theobromine) and catechin molecules present in some food beverages broadly consumed worldwide, such as coffee and tea, on Li-induced anti-inflammatory effects. In the present study, we concomitantly exposed RAW 264.7 macrophages to Li, isolated xanthine and catechin molecules, and a xanthine-catechin mixture (XC mixture). We evaluated the effects of these treatments on cell proliferation, cell cycle progression, oxidative and antioxidant marker expression, cytokine levels, gene expression, and GSK-3β enzyme expression. Treatment with the XC mixture potentialized Li-induced anti-inflammatory effects by intensification of the following: GSK-3β inhibitory action, lowering effect on proinflammatory cytokines (IL-1β, IL-6, and TNFα), and increase in the levels of IL-10 that is an anti-inflammatory cytokine. Despite the controversial nature of caffeine consumption by BD patients, these results suggested that consumption of caffeine, in low concentrations, mixed with other bioactive molecules along with Li may be safe.

Incomplete penetrance in mitochondrial optic neuropathies

Incomplete penetrance characterizes the two most frequent inherited optic neuropathies, Leber's Hereditary Optic Neuropathy (LHON) and dominant optic atrophy (DOA), due to genetic errors in the mitochondrial DNA (mtDNA) and the nuclear DNA (nDNA), respectively. For LHON, compelling evidence has accumulated on the complex interplay of mtDNA haplogroups and environmental interacting factors, whereas the nDNA remains essentially non informative. However, a compensatory mechanism of activated mitochondrial biogenesis and increased mtDNA copy number, possibly driven by a permissive nDNA background, is documented in LHON; when successful it maintains unaffected the mutation carriers, but in some individuals it might be hampered by tobacco smoking or other environmental factors, resulting in disease onset. In females, mitochondrial biogenesis is promoted and maintained within the compensatory range by estrogens, partially explaining the gender bias in LHON. Concerning DOA, none of the above mechanisms has been fully explored, thus mtDNA haplogroups, environmental factors such as tobacco and alcohol, and further nDNA variants may all participate as protective factors or, on the contrary, favor disease expression and severity. Next generation sequencing, complemented by transcriptomics and proteomics, may provide some answers in the next future, even if the multifactorial model that seems to apply to incomplete penetrance in mitochondrial optic neuropathies remains problematic, and careful stratification of patients will play a key role for data interpretation. The deep understanding of which factors impinge on incomplete penetrance may shed light on the pathogenic mechanisms leading to optic nerve atrophy, on their possible compensation and, thus, on development of therapeutic strategies.

Influence of Val16Ala-SOD2 polymorphism on sperm quality parameters

The purpose of this study was to investigate the association between the Val16Ala superoxide dismutase manganese-dependent (SOD2) single nucleotide polymorphism (SNP) and sperm reproductive parameters in a sample of Brazilian men. A potential association between this polymorphism and some oxidative biochemical parameters as well as sperm plasma cell-free DNA (cfDNA) levels were also evaluated. The study was performed using semen samples obtained from male patients that had undergone semen analysis according to the 2010 World Health Organisation (WHO) recommendations and the Val16Ala-SOD2 SNP was genotyped by polymerase chain reaction (PCR). Oxidative parameters as well as cfDNA levels were spectrophotometrically and fluorimetrically determined. Statistical analysis included chi-square test, analysis of variance followed by Bonferroni post hoc test, as well as logistic regression multivariate analysis. Semen samples from 169 men (35.89 ± 7.33 years) were genotyped. The allelic frequencies were V= 0.485 (n = 97), A = 0.515 (n = 103), with statistically similar allelic frequencies to those of samples obtained from a general population: V = 0.509; A= 0.591. In general, AV samples presented lower numbers of sperm-altered parameters than homozygous sperm. Lipoperoxidation was higher in homozygous than heterozygous sperm samples. The results suggest that genetically caused S-HP imbalance could contribute to poor sperm quality and affect male fertility.

ALA16VAL-MnSOD gene polymorphism and stroke: Association with dyslipidemia and glucose levels

Stroke risk has been associated to the progression of carotid plaques due to high glucose levels and lipid accumulation, which are greatly associated to cerebral injury, brain oxidative stress, and apoptosis. The ALA16VAL-MnSOD gene single nucleotide polymorphism (SNP) has shown to modulate risk factors of several metabolic and vascular diseases, such as blood glucose (GLU) and lipid levels. However, the association of these factors in stroke patients has not been studied to date. Thus, we evaluated the influence of the Ala16Val-MnSOD SNP on lipid profile, GLU levels, oxidative and DNA damage of 44 patients in a late phase of stroke (>6months). The statistical analysis showed a greater proportion of VV carries in stroke patients. The results also indicated that stroke patients had higher cholesterol (CHO) and GLU levels when compared to healthy counterparts. Interestingly, V allele carriers with stroke showed higher levels of CHO and GLU when compared to AA stroke and healthy counterparts. Our findings suggest that oxidative stress markers are still increased even after 6 months of cerebral injury. Furthermore, we propose that the Ala16Val-MnSOD SNPs may contribute to hypercholesterolemia and higher GLU levels, increasing the risk to neurovascular events that may lead to stroke.

Cytotoxic effects of moderate static magnetic field exposure on human periphery blood mononuclear cells are influenced by Val16Ala-MnSOD gene polymorphism

Technological advancement has increasingly exposed humans to magnetic fields (MFs). However, more insights are necessary into the potential toxicity of MF exposure as a result of genetic variations related to oxidative metabolism. Therefore, the following study has assessed an in vitro cytotoxic effect of static magnetic field (SMF) (5 mT) on cells with Val16Ala polymorphism (AA, VA, and VV) in the manganese superoxide dismutase gene. Homozygous Val16Ala-superoxide dismutase 2 (SOD2) genotypes present oxidative imbalance that is associated with risk to several chronic degenerative diseases (VV produces less efficient and AA more efficient SOD2 enzyme). Blood samples from healthy adult subject carriers with different Val16Ala-SOD2 genotypes were obtained and exposed to MF at different times (0, 1, 3, 6 h). The cytotoxic effect as well as oxidative stress was evaluated after incubation of 24 h at 37 °C. In addition, apoptosis induction has been analyzed by flow cytometry as well as Bcl-2-associated X protein (BAX), B-cell lymphoma 2 (BCL-2), and caspases 8 and 3 gene expression. SMF cytotoxic effect has been observed in AA cells at all times of exposure, whereas AV cells presented higher mortality only after 6 h of exposure at SMF. Higher apoptosis induction has been observed in AA cells when compared to VV and AV cells. These results suggest a toxicogenetic SMF effect related to an imbalance in SOD2 activity.

Selenium levels in human breast carcinoma tissue are associated with a common polymorphism in the gene for SELENOP (Selenoprotein P)

Selenium supplementation of the diets of rodents has consistently been shown to suppress mammary carcinogenesis and some, albeit not all, human epidemiological studies have indicated an inverse association between selenium and breast cancer risk. In order to better understand the role selenium plays in breast cancer, 30 samples of tumor tissue were obtained from women with breast cancer and analyzed for selenium concentration, the levels of several selenium-containing proteins and the levels of the MnSOD anti-oxidant protein. Polymorphisms within the genes for these same proteins were determined from DNA isolated from the tissue samples. There was a wide range of selenium in these tissues, ranging from 24 to 854ng/gm. The selenium levels in the tissues were correlated to the genotype of the SELENOP selenium carrier protein, but not to other proteins whose levels have been reported to be responsive to selenium availability, including GPX1, SELENOF and SBP1. There was an association between a polymorphism in the gene for MnSOD and the levels of the encoded protein. These studies were the first to examine the relationship between selenium levels, genotypes and protein levels in human tissues. Furthermore, the obtained data provide evidence for the need to obtain data about the effects of selenium in breast cancer by examining samples from that particular tissue type.

U-Shaped Association between Plasma Manganese Levels and Type 2 Diabetes

BACKGROUND

Manganese is both an essential element and a known toxicant, and it plays important roles in many mechanisms in relation to type 2 diabetes (T2D). However, epidemiological studies of this relationship are rare.

OBJECTIVE

We investigated the association between plasma manganese and newly diagnosed T2D as well as whether the association could be modified by manganese superoxide dismutase (MnSOD) polymorphisms.

METHODS

We conducted a case-control study of 3,228 participants in China: 1,614 T2D patients and 1,614 controls. Concentrations of plasma magnesium were measured, and all participants were genotyped for the MnSOD Val16Ala polymorphism (rs4880).

RESULTS

A U-shaped association was observed between plasma manganese and T2D, with increased odds ratios (ORs) in relation to either low or high plasma manganese levels. Compared with the middle tertile, the multivariate-adjusted ORs [95% confidence intervals (CIs)] of T2D associated with the lowest tertile and the highest tertile of plasma manganese were 1.89 (1.53, 2.33) and 1.56 (1.23, 1.97), respectively. In spline analysis, the U-shaped association was consistently indicated, with the lowest odds of T2D at the plasma manganese concentration of 4.95 μg/L. Minor allele frequencies (C allele) of the MnSOD Val16Ala polymorphism (rs4880) in the normal glucose tolerance (NGT) and the T2D groups were 13.57% and 14.50%, respectively. The MnSOD rs4880 polymorphism was not associated with T2D, and no interaction was found between plasma manganese and the MnSOD rs4880 polymorphism in relation to T2D.

CONCLUSIONS

Our results suggested a U-shaped association between plasma manganese and T2D; both low and high levels of plasma manganese were associated with higher odds of newly diagnosed T2D. The U-shaped association was not modified by the MnSOD rs4880 polymorphism. Citation: Shan Z, Chen S, Sun T, Luo C, Guo Y, Yu X, Yang W, Hu FB, Liu L. 2016. U-shaped association between plasma manganese levels and type 2 diabetes. Environ Health Perspect 124:1876-1881; http://dx.doi.org/10.1289/EHP176.

Computational Models of Reactive Oxygen Species as Metabolic Byproducts and Signal-Transduction Modulators

Reactive oxygen species (ROS) are widely involved in intracellular signaling and human pathologies, but their precise roles have been difficult to enumerate and integrate holistically. The context- and dose-dependent intracellular effects of ROS can lead to contradictory experimental results and confounded interpretations. For example, lower levels of ROS promote cell signaling and proliferation, whereas abundant ROS cause overwhelming damage to biomolecules and cellular apoptosis or senescence. These complexities raise the question of whether the many facets of ROS biology can be joined under a common mechanistic framework using computational modeling. Here, we take inventory of some current models for ROS production or ROS regulation of signaling pathways. Several models captured non-intuitive observations or made predictions that were later verified by experiment. There remains a need for systems-level analyses that jointly incorporate ROS production, handling, and modulation of multiple signal-transduction cascades.

The effects of rosuvastatin on lipid-lowering, inflammatory, antioxidant and fibrinolytics blood biomarkers are influenced by Val16Ala superoxide dismutase manganese-dependent gene polymorphism

Rosuvastatin is a cholesterol-lowering drug that also attenuates the inflammatory process and oxidative stress via the reduction of superoxide anion production. Superoxide anions are metabolized by manganese-dependent superoxide dismutase (MnSOD or SOD2) in the mitochondria. In humans, there is a gene polymorphism where a change of alanine (Ala) to valine (Val) occurs at the 16th amino acid (Ala16Val-SOD2). The VV genotype has been associated with the risk of developing several metabolic diseases, such as hypercholesterolemia. Thus, to further explore this phenomenon, this study investigated the influence of the Val16Ala-SOD2 polymorphism on the lipid profile and inflammatory and fibrinolytic biomarkers of 122 hypercholesterolemic patients undergoing the first pharmacological cholesterol-lowering therapy who were treated with 20 mg rosuvastatin for 120 days. The findings indicate that the VV patients who present a low-efficiency SOD2 enzyme exhibit an attenuated response to rosuvastatin compared with the A-allele patients. The effect of rosuvastatin on inflammatory and fibrinolytic biomarkers was also less intense in the VV patients. These results suggest some pharmacogenetic effects of Val16Ala-SOD2 in hypercholesterolemia treatment.

Superoxide Dismutase 2 Genetic Variation as a Susceptibility Risk Factor for Alcoholic Cirrhosis

AIMS

Superoxide dismutase 2 (SOD2) is an important antioxidant phase 2 enzyme. The associations of SOD2 genetic variation and the risk of advanced alcoholic liver diseases are still debatable. We aimed to investigate the association of the main SOD2 genetic variant (47T>C) and the susceptibility to alcoholic cirrhosis.

METHODS

A total of 80 patients with alcoholic cirrhosis (AC), 80 patients with alcoholic non-cirrhosis (ANC), 80 with viral hepatitis B-related cirrhosis (VC), and 165 healthy controls (HC) were enrolled into this study. A polymerase chain reaction was used to genotype their SOD2 47T>C (rs4880).

RESULTS

There was no statistical difference in the frequency distribution of the three SOD2 47T>C genotypes among groups. However, if individuals with C variant were grouped together, the AC group had higher frequency of SOD2 C/C or C/T genotype than ANC, VC and HC groups had (38.7% vs. 21.3%, 26.3% and 21.8%, respectively, P = 0.010). After adjustment for confounders, the SOD2 C/C and C/T genotypes remained associated with the risk of AC (adjusted OR: 2.79 and 3.50, respectively, P < 0.03, compared with ANC and HC groups). In contrast, there was no significant difference of SOD2 genetic variation between VC and HC groups.

CONCLUSIONS

Anti-oxidative enzyme SOD2 47T>C genetic variant may increase the susceptibility to AC. This suggests that oxidative stress plays a role in the development of AC.