The In Vitro Influence of a Genetic Superoxide-Hydrogen Peroxide Imbalance on Immunosenescence

Evaluation of antioxidant parameters of multiple sclerosis patients' serum according to the disease course

INTRODUCTION

Multiple sclerosis (MS) is a chronic, demyelinating disease of the central nervous system. Its clinical courses are clinically isolated syndrome (CIS), relapsing remitting (RRMS), secondary progressive (SPMS), and primary progressive (PPMS). The differentiation of MS types is crucial for adequate treatment.

OBJECTIVES

To evaluate antioxidant parameters of MS patients' serum according to MS type.

MATERIALS AND METHODS

The study included 84 patients diagnosed with MS. The study group was divided into three subgroups corresponding to MS courses RRMS, SPMS, and PPMS. Sulfhydryl groups (SH), ceruloplasmin (CER), and superoxide dismutase (SOD) and its isoforms were identified in study participants' sera.

RESULTS

CuZnSOD levels were significantly higher in SPMS patients than in PPMS patients, but there was no difference between SMPS and treatment-naive PPMS patients. MnSOD activity was significantly lower in SPMS patients than in PPMS patients. Our results show that SH levels were decreased in SPMS patients compared with RRMS patients, but this difference was significant only for male participants. SH concentration was reversely correlated with age, BMI, disease duration, EDSS, and in smoking patients with pack-years. CER serum levels waere elevated in SPMS patients compared with RRMS patients, but this difference was significant only for male participants. Our results show correlation between CER and EDSS levels.

CONCLUSION

Oxidative stress plays a limited role in all disease stages, particularly in smokers as a confounding factor.

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.

Superoxide-imbalance pharmacologically induced by rotenone triggers behavioral, neural, and inflammatory alterations in the Eisenia fetida earthworm

BACKGROUND

Some studies have suggested that mitochondrial dysfunction and a superoxide imbalance could increase susceptibility to chronic stressful events, contributing to the establishment of chronic inflammation and the development of mood disorders. The mitochondrial superoxide imbalance induced by some molecules, such as rotenone, could be evolutionarily conserved, causing behavioral, immune, and neurological alterations in animals with a primitive central nervous system.

OBJECTIVE

Behavioral, immune, and histological markers were analyzed in Eisenia fetida earthworms chronically exposed to rotenone for 14 days.

METHODS

Earthworms were placed in artificial soil containing 30 nM of rotenone distributed into a plastic cup that allowed the earthworms to leave and return freely into the ground. Since these organisms prefer to be buried, the model predicted that the earthworms would necessarily have to return to the rotenone-contaminated medium, creating a stressful condition. The effect on survival behavior in the immune and histological body wall and ventral nervous ganglia (VNG) structures, as well as gene expression related to inflammation and mitochondrial and neuromuscular changes.

RESULTS

Rotenone-induced loss of earthworm escape behavior and immune alterations indicated a chronic inflammatory state. Some histological changes in the body wall and VNG indicated a possible earthworm reaction aimed at protecting against rotenone. Overexpression of the nicotinic acetylcholine receptor gene (nAChR α5) in neural tissues could also help earthworms reduce the degenerative effects of rotenone on dopaminergic neurons.

CONCLUSION

These data suggest that mitochondrial dysfunction could be an evolutionarily conserved element that induces inflammatory and behavioral changes related to chronic stress.

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.

Unmetabolized quetiapine exerts an in vitro effect on innate immune cells by modulating inflammatory response and neutrophil extracellular trap formation

Quetiapine is an antipsychotic drug that is used to treat psychiatric and neurological disorders. Despite its efficiency and low-toxicity, quetiapine administration has been associated with undesirable side effects such as the development of low-grade inflammatory disorders and neutropenia states. As the liver rapidly metabolizes quetiapine to metabolites, the non-metabolized part of this molecule might play a role in immune alterations. In an in vitro study, this hypothesis was tested by exposing activated and inactivated RAW-264.7 macrophages and human neutrophils to unmetabolized quetiapine (u-QUE). Based on our findings, u-QUE was not cytotoxic to these cells. u-QUE differentially modulates macrophages according to their activation states. In inactivated macrophages, u-QUE induced a proinflammatory state as observed by an increase in cellular proliferation; increased levels of oxidative molecules (nitric oxide and superoxide), protein levels, and gene overexpression of proinflammatory cytokines (IL-1β, IL-6, and TNF-α); and decreased levels of IL-10, an anti-inflammatory cytokine. Conversely, on phytohemagglutinin (PHA)-activated macrophages, u-QUE exerted an anti-inflammatory effect. u-QUE induced neutrophil extracellular trap (NET) formation and increased the sensitivity of the neutrophils previously activated by exposure to dead yeast cells for NET formation. These results confirm the effect of quetiapine on macrophage and neutrophil function, which may be associated with the side effects of this psychopharmaceutical agent.

Superoxide imbalance triggered by Val16Ala-SOD2 polymorphism increases the risk of depression and self-reported psychological stress in free-living elderly people

BACKGROUND

Oxidative stress and chronic inflammatory states triggered by a single-nucleotide polymorphism (SNP) in superoxide dismutase manganese-dependent gene (Val16Ala-SOD2) have been associated with the risk of developing several chronic, nontransmissible diseases. However, it is still not clear whether the VV-SOD2 genotype that causes higher basal superoxide anion levels has any impact on the risk for depression and self-reported psychological stress in elderly people.

METHODS

In the present study, we tested this hypothesis using a case-control study where depression was detected using the Geriatric Depression Scale-15 (GDS-15). A total of 612 Brazilian free-living elderly subjects with a mean age of 67.1 ± 7.1 years old (number of controls, C = 497, and depressive individuals, D = 115) were included in this study. All participants had similar social, health, and lifestyle variables, with the exception of polypharmacy (≥5 medicines daily intake), which was higher in the D group, compared to C subjects.

RESULTS

Our results showed that the VV-SOD2 genotype significantly increased the risk for depression and psychological stress in the elderly subjects, independently of sex/gender, age, and other prior diseases and health indicators (depression risk = 1.842, 1.109-3.061 95% CI, p = .018). VV-subjects also had a higher daily intake of antidepressants, anxiolytics, and anti-inflammatory drugs than A-allele subjects.

CONCLUSION

Our findings support the hypothesis that genetically induced oxidative superoxide-hydrogen peroxide imbalance may be involved in an increased risk for developing depression and psychological stress in free-living elderly people without other chronic nontransmissible diseases.

In vitro effect of low-level laser therapy on the proliferative, apoptosis modulation, and oxi-inflammatory markers of premature-senescent hydrogen peroxide-induced dermal fibroblasts

Skin aging is a complex biological process induced by intrinsic and extrinsic factors which is characterized by clinical and cellular changes, especially dermal fibroblasts. It is possible that, some procedures, such as low-level laser therapy (LLLT), could decelerate this process. To test this hypothesis, this study evaluated the in vitro LLLT on dermal fibroblast cell line (HFF-1) with premature senescence H2O2-induced. HFF-1 cells were cultured in standardized conditions, and initially H2O2 exposed at different concentrations. Fibroblasts were also just exposed at different LLLT (660 nm) doses. From these curves, the lowest H2O2 concentration that induced indicators of premature senescence and the lowest LLLT doses that triggered fibroblast proliferation were used in all assays. Cellular mortality, proliferation, and the levels of oxidative, inflammatory cytokines, apoptotic markers, and of two growth signaling molecules (FGF-1 and KGF) were compared among treatments. The H2O2 at 50 μM concentration induced some fibroblast senescence markers and for LLLT, the best dose for treatment was 4 J (p < 0.001). The interaction between H2O2 at 50 μM and LLLT at 4 J showed partially reversion of the higher levels of DNA oxidation, CASP 3, CASP 8, IL-1B, IL-6, and INFy induced by H2O2 exposure. LLLT also trigger increase of IL-10 anti-inflammatory cytokine, FGF-1 and KGF levels. Cellular proliferation was also improved when fibroblasts treated with H2O2 were exposed to LLLT (p < 0.001). These results suggest that in fibroblast with some senescence characteristics H2O2-induced, the LLLT presented an important protective and proliferative action, reverting partially or totally negative effects triggering by H2O2.

Polymorphism eNOS Glu298Asp modulates the inflammatory response of human peripheral blood mononuclear cells

INTRODUCTION

Nitric oxide is a gaseous radical produced by the nitric oxide endothelial synthase (eNOS) whose most studied physiological action is the vasodilation. However, it also acts in the defense of the organism through the formation of cytotoxic radicals, which can potentiate the inflammatory lesion of the cells. The Glu298Asp is a single nucleotide polymorphism (SNP) in the eNOS gene related to the risk of cardiovascular disease. Blacks present a higher prevalence of hypertension and cardiovascular mortality. Then, we aimed to evaluate the influence of Glu298Asp polymorphism on inflammatory response in vitro and gene expression in blacks.

MATERIAL AND METHODS

Peripheral blood mononuclear cells (PBMC) from blacks with different Glu298Asp genotypes were treated with phytohemagglutinin (PHA), a mitogen and activator of T cells. Oxidative, inflammatory markers, and expression of inflammation genes were evaluated.

RESULTS

The genotype frequencies were TT 6.7%; TG 29.3% and GG 64.0%. Activation of PBMCs with 125 μg of PHA modulated the expression of inflammatory genes and increased levels of inflammatory cytokines. The T allele showed increased susceptibility to inflammation (higher levels of interleukin 1, interleukin 6 and tumor necrosis factor alpha; p < 0.001). The G allele exhibited protection through higher levels of nitric oxide (p < 0.001) and fewer inflammatory cytokines.

CONCLUSION

Despite methodological limitations related to in vitro assays, the whole of results suggested that Glu298Asp modulates inflammatory genes, the T allele is more susceptible to inflammation and the G allele is protective.

Hydrogen Indirectly Suppresses Increases in Hydrogen Peroxide in Cytoplasmic Hydroxyl Radical-Induced Cells and Suppresses Cellular Senescence

Bacteria inhabiting the human gut metabolize microbiota-accessible carbohydrates (MAC) contained in plant fibers and subsequently release metabolic products. Gut bacteria produce hydrogen (H₂), which scavenges the hydroxyl radical (•OH). Because H₂ diffuses within the cell, it is hypothesized that H₂ scavenges cytoplasmic •OH (cyto •OH) and suppresses cellular senescence. However, the mechanisms of cyto •OH-induced cellular senescence and the physiological role of gut bacteria-secreted H₂ have not been elucidated. Based on the pyocyanin-stimulated cyto •OH-induced cellular senescence model, the mechanism by which cyto •OH causes cellular senescence was investigated by adding a supersaturated concentration of H₂ into the cell culture medium. Cyto •OH-generated lipid peroxide caused glutathione (GSH) and heme shortage, increased hydrogen peroxide (H₂O₂), and induced cellular senescence via the phosphorylation of ataxia telangiectasia mutated kinase serine 1981 (p-ATM^ser1981)/p53 serine 15 (p-p53^ser15)/p21 and phosphorylation of heme-regulated inhibitor (p-HRI)/phospho-eukaryotic translation initiation factor 2 subunit alpha serine 51 (p-eIF2α)/activating transcription factor 4 (ATF4)/p16 pathways. Further, H₂ suppressed increased H₂O₂ by suppressing cyto •OH-mediated lipid peroxide formation and cellular senescence induction via two pathways. H₂ produced by gut bacteria diffuses throughout the body to scavenge cyto •OH in cells. Therefore, it is highly likely that gut bacteria-produced H₂ is involved in intracellular maintenance of the redox state, thereby suppressing cellular senescence and individual aging. Hence, H₂ produced by intestinal bacteria may be involved in the suppression of aging.

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.