Oxidative stress and its biomarkers in systemic lupus erythematosus

Abnormal Mitochondrial Physiology in the Pathogenesis of Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disorder characterized by abnormalities within the innate and adaptive immune systems. Activation and proliferation of a wide array of immune cells require significant up-regulation in cellular energy metabolism, with the mitochondria playing an essential role in the initiation and maintenance of this response. This article highlights how abnormal mitochondrial function may occur in SLE and focuses on how energy metabolism, oxidative stress, and impaired mitochondrial repair play a role in the pathogenesis of the disease. How this may represent an appealing novel therapeutic target for future drug therapy in SLE also is discussed.

Shotgun mass spectrometry-based lipid profiling identifies and distinguishes between chronic inflammatory diseases

Background

Localized stress and cell death in chronic inflammatory diseases may release tissue-specific lipids into the circulation causing the blood plasma lipidome to reflect the type of inflammation. However, deep lipid profiles of major chronic inflammatory diseases have not been compared.

Methods

Plasma lipidomes of patients suffering from two etiologically distinct chronic inflammatory diseases, atherosclerosis-related vascular disease, including cardiovascular (CVD) and ischemic stroke (IS), and systemic lupus erythematosus (SLE), were screened by a top-down shotgun mass spectrometry-based analysis without liquid chromatographic separation and compared to each other and to age-matched controls. Lipid profiling of 596 lipids was performed on a cohort of 427 individuals. Machine learning classifiers based on the plasma lipidomes were used to distinguish the two chronic inflammatory diseases from each other and from the controls.

Findings

Analysis of the lipidomes enabled separation of the studied chronic inflammatory diseases from controls based on independent validation test set classification performance (CVD vs control - Sensitivity: 0.94, Specificity: 0.88; IS vs control - Sensitivity: 1.0, Specificity: 1.0; SLE vs control – Sensitivity: 1, Specificity: 0.93) and from each other (SLE vs CVD ‒ Sensitivity: 0.91, Specificity: 1; IS vs SLE - Sensitivity: 1, Specificity: 0.82). Preliminary linear discriminant analysis plots using all data clearly separated the clinical groups from each other and from the controls, and partially separated CVD severities, as classified into five clinical groups. Dysregulated lipids are partially but not fully counterbalanced by statin treatment.

Interpretation

Dysregulation of the plasma lipidome is characteristic of chronic inflammatory diseases. Lipid profiling accurately identifies the diseases and in the case of CVD also identifies sub-classes.

Funding

Full list of funding sources at the end of the manuscript.

Cellular Response against Oxidative Stress, a Novel Insight into Lupus Nephritis Pathogenesis

The interaction of reactive oxygen species (ROS) with lipids, proteins, nucleic acids and hydrocarbonates promotes acute and chronic tissue damage, mediates immunomodulation and triggers autoimmunity in systemic lupus erythematous (SLE) patients. The aim of the study was to determine the pathophysiological mechanisms of the oxidative stress-related damage and molecular mechanisms to counteract oxidative stimuli in lupus nephritis. Our study included 38 SLE patients with lupus nephritis (LN group), 44 SLE patients without renal impairment (non-LN group) and 40 healthy volunteers as control group. In the present paper, we evaluated serum lipid peroxidation, DNA oxidation, oxidized proteins, carbohydrate oxidation, and endogenous protective systems. We detected defective DNA repair mechanisms via 8-oxoguanine-DNA-glycosylase (OGG1), the reduced regulatory effect of soluble receptor for advanced glycation end products (sRAGE) in the activation of AGE-RAGE axis, low levels of thiols, disulphide bonds formation and high nitrotyrosination in lupus nephritis. All these data help us to identify more molecular mechanisms to counteract oxidative stress in LN that could permit a more precise assessment of disease prognosis, as well as developing new therapeutic targets.

Effects of melatonin supplementation on serum oxidative stress markers and disease activity in systemic lupus erythematosus patients: A randomised, double-blind, placebo-controlled trial

BACKGROUND

Considering pathological significance of oxidative stress in systemic lupus erythematosus (SLE), current research aimed to evaluate the effects of melatonin supplementation on oxidative stress markers and disease activity in SLE.

METHOD

In this randomised double-blind, placebo-controlled trial, 32 SLE females were selected and randomly assigned into two groups to take 10 mg/day melatonin or placebo for 12 weeks. Before and after trial, serum malondialdehyde (MDA) and total antioxidant capacity (TAC) were measured and disease activity was determined by Systemic lupus erythematosus disease activity index 2000 (SLEDAI-2K).

RESULTS

Twenty-five patients (13 in the melatonin and 12 in the placebo groups) completed the trial. Melatonin supplementation caused significant reduction in serum MDA compared with baseline (P = .003) and placebo group (P = .004). Serum TAC level did not change significantly in the melatonin group compared with baseline and placebo group (P > .05). Furthermore, melatonin supplementation did not cause significant change in disease activity compared to baseline and placebo group (P > .05).

CONCLUSION

This study demonstrated affirmative effects of melatonin in decreasing oxidative stress in SLE patients without any effect on disease activity. Further investigations are required to affirm these primitive findings and to achieve concise conclusions.What's known Free radical damage and oxidative stress has a remarkable function in systemic lupus erythematosus (SLE) pathogenesis. Products derived from oxidative modification cascades are found in biological fluids and their redundancy has a correlation with disease activity and organ damage in SLE. Dietary supplements, which decrease oxidative stress, would be useful in managing SLE. Melatonin is a potent antioxidant and has anti-inflammatory and immunomodulatory characteristics. Limited in vitro and animal studies are available indicating desirable effects of melatonin in preventing from SLE organ damage, thereby opening a new area of investigation that can contribute to using melatonin as a therapy or co-therapy for SLE. What's new Melatonin supplementation caused significant reduction in serum MDA compared with baseline and placebo group. Serum TAC level did not change significantly in the melatonin group compared with baseline and placebo group. Furthermore, melatonin supplementation did not cause significant change in disease activity compared to baseline and placebo group.

Indoxyl-Sulfate-Induced Redox Imbalance in Chronic Kidney Disease

The accumulation of the uremic toxin indoxyl sulfate (IS) induces target organ damage in chronic kidney disease (CKD) patients, and causes complications including cardiovascular diseases, renal osteodystrophy, muscle wasting, and anemia. IS stimulates reactive oxygen species (ROS) production in CKD, which impairs glomerular filtration by a direct cytotoxic effect on the mesangial cells. IS further reduces antioxidant capacity in renal proximal tubular cells and contributes to tubulointerstitial injury. IS-induced ROS formation triggers the switching of vascular smooth muscular cells to the osteoblastic phenotype, which induces cardiovascular risk. Low-turnover bone disease seen in early CKD relies on the inhibitory effects of IS on osteoblast viability and differentiation, and osteoblastic signaling via the parathyroid hormone. Excessive ROS and inflammatory cytokine releases caused by IS directly inhibit myocyte growth in muscle wasting via myokines’ effects. Moreover, IS triggers eryptosis via ROS-mediated oxidative stress, and elevates hepcidin levels in order to prevent iron flux in circulation in renal anemia. Thus, IS-induced oxidative stress underlies the mechanisms in CKD-related complications. This review summarizes the underlying mechanisms of how IS mediates oxidative stress in the pathogenesis of CKD’s complications. Furthermore, we also discuss the potential role of oral AST-120 in attenuating IS-mediated oxidative stress after gastrointestinal adsorption of the IS precursor indole.

Deciphering the functional role of EGR1 in Prostaglandin F2 alpha induced luteal regression applying CRISPR in corpus luteum of buffalo

Background

PGF2α is essential for the induction of the corpus luteum regression which in turn reduces progesterone production. Early growth response (EGR) proteins are Cys2-His2-type zinc-finger transcription factor that are strongly linked to cellular proliferation, survival and apoptosis. Rapid elevation of EGR1 was observed after luteolytic dose of PGF2α. EGR1 is involved in the transactivation of many genes, including TGFβ1, which plays an important role during luteal regression.

Methods

The current study was conducted in buffalo luteal cells with the aim to better understand the role of EGR1 in transactivation of TGFβ1 during PGF2α induced luteal regression. Luteal cells from mid stage corpus luteum of buffalo were cultured and treated with different doses of PGF2α for different time durations. Relative expression of mRNAs encoding for enzymes within the progesterone biosynthetic pathway (3βHSD, CYP11A1 and StAR); Caspase 3; AKT were analyzed to confirm the occurrence of luteolytic event. To determine if EGR1 is involved in the PGF2α induced luteal regression via induction of TGFβ1 expression, we knocked out the EGR1 gene by using CRISPR/Cas9.

Result

The present experiment determined whether EGR1 protein expression in luteal cells was responsive to PGF2α treatment. Quantification of EGR1 and TGFβ1 mRNA showed significant up regulation in luteal cells of buffalo at 12 h post PGF2α induction. In order to validate the role of PGF2α on stimulating the expression of TGFβ1 by an EGR1 dependent mechanism we knocked out EGR1. The EGR1 ablated luteal cells were stimulated with PGF2α and it was observed that EGR1 KO did not modulate the PGF2α induced expression of TGFβ1. In PGF2α treated EGR1 KO luteal cell, the mRNA expression of Caspase 3 was significantly increased compared to PGF2α treated wild type luteal cells maintained for 12 h. We also studied the influence of EGR1 on steroidogenesis. The EGR1 KO luteal cells with PGF2α treatment showed no substantial difference either in the progesterone concentration or in StAR mRNA expression with PGF2α-treated wild type luteal cells.

Conclusion

These results suggest that EGR1 signaling is not the only factor which plays a role in the regulation of PGF2α induced TGFβ1 signaling for luteolysis.

Primary Cilia and Atherosclerosis

In artery tree, endothelial function correlates with the distribution of shear stress, a dragging force generated by flowing blood. In laminar shear stress areas, endothelial cells (ECs) are available to prevent atherosclerosis, however, ECs in disturbed shear stress sites are featured with proinflammation and atherogenesis. Basic studies in the shear stress field that focused on the mechanosensors of ECs have attracted the interest of researchers. Among all the known mechanosensors, the primary cilium is distinctive because it is enriched in disturbed shear stress regions and sparse in laminar shear stress areas. The primary cilium, a rod liked micro-organelle, can transmit extracellular mechanical and chemical stimuli into intracellular space. In the cardiovascular system, primary cilia are enriched in disturbed shear stress regions, where blood flow is slow and oscillatory, such as the atrium, downstream of the aortic valve, branches, bifurcations, and inner curves of the artery. However, in the atrioventricular canal and straight vessels, blood flow is laminar, and primary cilia can barely be detected. Primary cilia in the heart cavity prevent ECs from mesenchymal transition and calcification by suppressing transforming growth factor (TGF) signaling. Besides, primary cilia in the vascular endothelium protected ECs against disturbed shear stress-induced cellular damage by triggering Ca²⁺ influx as well as nitric oxide (NO) release. Moreover, primary cilia inhibit the process of atherosclerosis. In the current review, we discussed ciliogenesis, ciliary structure, as well as ciliary distribution, function and the coordinate signal transduction with shear stress in the cardiovascular system.

Toxicant exposure during pregnancy increases protective proteins in the dam and a sexually dimorphic response in the fetus

Endocrine disrupting compounds (EDCs) are ubiquitous environmental pollutants that alter endocrine system function, induce birth defects, and a myriad of other negative health outcomes. Although the mechanism of toxicity of many EDCs have been studied in detail, little work has focused on understanding the mechanisms through which pregnant dams and fetuses protect themselves from EDCs, or if those protective mechanisms are sexually dimorphic in fetuses. In this study, we examined proteomic alterations in the livers of mouse dams and their male and female fetuses induced by vinclozolin, a model antiandrogenic EDC. Dam livers upregulated nine phase I and phase II detoxification pathways and pathway analysis revealed that more pathways are significantly enriched in dam livers than in fetal livers. Phase I and II detoxification proteins are also involved in steroid and steroid hormone biosynthesis and vinclozolin likely alters steroid levels in both the dam and the fetus. The response of the fetal liver proteome to vinclozolin exposure is sexually dimorphic. Female fetal livers upregulated proteins in xenobiotic metabolism pathways, whereas male fetal livers upregulated proteins in oxidative phosphorylation pathways. These results suggest that female fetuses increase protective mechanisms, whereas male fetuses increase ATP production and several disease pathways that are indicative of oxidative damage. Females fetuses upregulate proteins and protective pathways that were similar to the dams whereas males did not. If this sexually dimorphic pattern is typical, then males might generally be more sensitive to EDCs.

HLA-DRB1*04 as a Risk Allele to Systemic Lupus Erythematosus and Lupus Nephritis in the Malay Population of Malaysia

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease afflicting multiple organs. Lupus nephritis (LN) is a serious complication of SLE and remains a major cause of mortality and morbidity. Curative therapy remains unavailable as etiology from genetic and environmental factors is still unclear. The present study was conducted to elucidate the link between HLA-DRB1 gene polymorphisms with SLE and LN through clinical and laboratory/biological presentations in a population of Malaysian Malay females with SLE. A total of 100 Malay female SLE patients inclusive of 70 SLE patients without LN and 30 patients with LN were included in this study. HLA-DRB1 allele examination in SLE patients was performed using PCR-SSO, and the alleles' frequencies were compared with 951 publicly available datasets representing Malay healthy controls in Malaysia. Cytokines and free radical levels were detected by ELISA and bead-based multiplexed Luminex assays. The association between HLA-DRB1 alleles with clinical and serological manifestations and immune mediators was analyzed using different statistical approaches whenever applicable. Our study showed that HLA-DRB1^*0405, HLA-DRB1^*1502, and HLA-DRB1^*1602 were associated with the increased risk of SLE while HLA-DRB1^*1201 and HLADRB1^*1202 alleles were associated with a lower risk of SLE development. Furthermore, HLA-DRB1^*04 showed significant association to LN and arthritis while HLA-DRB1^*15 was significantly associated with oral ulcer in Malay SLE patients. Association analysis of HLA-DRB1^*04 with clinical and biological factors revealed that HLA-DRB1^*04 was significantly associated with Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) scores, anti-nuclear antibody (ANA), C-reactive protein (CRP) in the blood, and total protein in the urine. SLE carriers with the HLA-DRB1^*04 allele were significantly correlated to the increased levels of cytokines (IFN-y, GM-CSF, IL-17F, IL-18, IL-21, and VEGF) and were significantly showing negative correlation to IL-5 and free radicals (LPO and catalase enzyme) levels compared to SLE carriers without HLA-DRB1^*04 allele. The results suggested that disease severity in SLE may be determined by HLA-DRB1 alleles. The risk of HLA-DRB1^*04 allele with LN was supported by the demonstration of an intense inflammatory response in Malay SLE patients in Malaysia. More studies inclusive of a larger and multiple SLE cohorts in the future are warranted to validate these findings.

Artemisinin analogue SM934 protects against lupus-associated antiphospholipid syndrome via activation of Nrf2 and its targets

Kidney is a major target organ in both antiphospholipid syndrome (APS) and systemic lupus erythematosus (SLE). The etiology of antiphospholipid syndrome nephropathy associated lupus nephritis (APSN-LN) is intricate and remains largely unrevealed. We proposed in present work, that generation of antiphospholipid antibodies (aPLs), especially those directed towards the oxidized neoepitopes, are largely linked with the redox status along with disease progression. Moreover, we observed that compromised antioxidative capacity coincided with turbulence of inflammatory cytokine profile in the kidney of male NZW×BXSB F1 mice suffered from APSN-LN. SM934 is an artemisinin derivative that has been proved to have potent immunosuppressive properties. In current study, we elaborated the therapeutic benefits of SM934 in male NZW×BXSB F1 mice, a murine model develops syndrome resembled human APS associated with SLE, for the first time. SM934 treatment comprehensively impeded autoantibodies production, inflammatory cytokine accumulation and excessive oxidative stress in kidney. Among others, we interpreted in present work that both anti-inflammatory and antioxidative effects of SM934 is closely correlated with the enhancement of Nrf2 signaling and expression of its targets. Collectively, our finding confirmed that therapeutic strategy simultaneously exerting antioxidant and anti-inflammatory efficacy provide a novel feasible remedy for treating APSN-LN.

Oxidative Stress and Lipid Mediators Modulate Immune Cell Functions in Autoimmune Diseases

Autoimmune diseases, including psoriasis, systemic lupus erythematosus (SLE), and rheumatic arthritis (RA), are caused by a combination of environmental and genetic factors that lead to overactivation of immune cells and chronic inflammation. Since oxidative stress is a common feature of these diseases, which activates leukocytes to intensify inflammation, antioxidants could reduce the severity of these diseases. In addition to activating leukocytes, oxidative stress increases the production of lipid mediators, notably of endocannabinoids and eicosanoids, which are products of enzymatic lipid metabolism that act through specific receptors. Because the anti-inflammatory CB2 receptors are the predominant cannabinoid receptors in leukocytes, endocannabinoids are believed to act as anti-inflammatory factors that regulate compensatory mechanisms in autoimmune diseases. While administration of eicosanoids in vitro leads to the differentiation of lymphocytes into T helper 2 (Th2) cells, eicosanoids are also necessary for the different0iation of Th1 and Th17 cells. Therefore, their antagonists and/or the genetic deletion of their receptors abolish inflammation in animal models of psoriasis—RA and SLE. On the other hand, products of non-enzymatic lipid peroxidation, especially acrolein and 4-hydroxynonenal-protein adducts, mostly generated by an oxidative burst of granulocytes, may enhance inflammation and even acting as autoantigens and extracellular signaling molecules in the vicious circle of autoimmune diseases.

Gene expression signatures of target tissues in type 1 diabetes, lupus erythematosus, multiple sclerosis, and rheumatoid arthritis

Autoimmune diseases are typically studied with a focus on the immune system, and less attention is paid to responses of target tissues exposed to the immune assault. We presently evaluated, based on available RNA sequencing data, whether inflammation induces similar molecular signatures at the target tissues in type 1 diabetes, systemic lupus erythematosus, multiple sclerosis, and rheumatoid arthritis. We identified confluent signatures, many related to interferon signaling, indicating pathways that may be targeted for therapy, and observed a high (>80%) expression of candidate genes for the different diseases at the target tissue level. These observations suggest that future research on autoimmune diseases should focus on both the immune system and the target tissues, and on their dialog. Discovering similar disease-specific signatures may allow the identification of key pathways that could be targeted for therapy, including the repurposing of drugs already in clinical use for other diseases.

The relationship of ischemia-modified albumin levels to disease activity scores and HLA-B27 in patients with ankylosing spondylitis

OBJECTIVE:

Recent studies have implicated increased oxidative stress in the pathogenesis of Ankylosing spondylitis (AS). Ischemia-modified albumin (IMA), an altered form of albumin, increases oxidative stress. This study aimed to investigate the relationship between IMA levels and other indicators of disease severity in AS.

METHODS:

This study included 63 AS patients and 48 healthy controls. Patients were examined for serum lipid profile, C-reactive protein (CRP), complete blood count, Bath Ankylosing Spondylitis Disease Activity Index, human leukocyte antigen (HLA) B27, and treatment regimen. They were categorized based on disease activity, HLA-B27 status, and the drug treatment and compared for IMA levels.

RESULTS:

The patients had significantly higher IMA levels than controls (p=0.020); among patients, the levels were higher in those with active disease (p=0.001) and positively correlated with the CRP levels. No significant difference was found between the IMA levels of the patients with different HLA-B27 status or treatment method.

CONCLUSION:

The IMA levels were higher in patients than controls and further increased in patients with active AS. IMA was associated with disease activity and can be used as an inflammatory marker in AS. More comprehensive future studies with a larger sample size may help understand the relationship in greater detail.

Altered oxidative stress markers in relation to T cells, NK cells & killer immunoglobulin receptors that are associated with disease activity in SLE patients

Systemic Lupus Erythematosus is an autoimmune disease with symptoms pervasive to all organ systems. It affects more females as compared to males (in the ratio 9:1). Oxidative stress plays a major role in the pathogenesis of SLE and other autoimmune diseases. In order to understand the relationship between cell specific oxidative stress and the severity of SLE, this research study involving the estimation of intracellular ROS accumulation in T and NK cell was conducted on SLE patients of North Indian Population. At the same time, to estimate anti-oxidant defense, Keap1 and Nrf2 levels were estimated in these cell types. The relationship between the expression of Killer immunoglobulin receptors i.e., KIR2DL4 & KIR3DL1 and oxidative stress was also evaluated as these receptors are imperative for the function and self-tolerance of NK cells.Oxidative stress was raised along with Keap1 and Nrf2 in T and NK cell subsets in SLE patients. The expression of KIR2DL4 was raised and that of KIR3DL1 was reduced in the NK cells of patients. The intensity of change in expression and its significance varied among the subsets. Nrf2 expression was raised in these species against oxidative stress as the antioxidant defense mechanism pertaining to Keap1-Nrf2 pathway, but the adequacy of response needs to be understood in further studies. The expression of KIR2DL4 and KIR3DL1 varied among the patient and healthy controls and the expression of the latter was found to have a significant positive relationship with plasma Glutathione(reduced) concentration.

Regulating the Polarization of Macrophages: A Promising Approach to Vascular Dermatosis

Macrophages, a kind of innate immune cells, derive from monocytes in circulation and play a crucial role in the innate and adaptive immunity. Under the stimulation of the signals from local microenvironment, macrophages generally tend to differentiate into two main functional phenotypes depending on their high plasticity and heterogeneity, namely, classically activated macrophage (M1) and alternatively activated macrophage (M2). This phenomenon is often called macrophage polarization. In pathological conditions, chronic persistent inflammation could induce an aberrant response of macrophage and cause a shift in their phenotypes. Moreover, this shift would result in the alteration of macrophage polarization in some vascular dermatoses; e.g., an increase in proinflammatory M1 emerges from Behcet's disease (BD), psoriasis, and systemic lupus erythematosus (SLE), whereas an enhancement in anti-inflammatory M2 appears in infantile hemangioma (IH). Individual polarized phenotypes and their complicated cytokine networks may crucially mediate in the pathological processes of some vascular diseases (vascular dermatosis in particular) by activation of T cell subsets (such as Th1, Th2, Th17, and Treg cells), deterioration of oxidative stress damage, and induction of angiogenesis, but the specific mechanism remains ambiguous. Therefore, in this review, we discuss the possible role of macrophage polarization in the pathological processes of vascular skin diseases. In addition, it is proposed that regulation of macrophage polarization may become a potential strategy for controlling these disorders.

Oxidative stress in alcohol-related liver disease

Alcohol consumption is one of the leading causes of the global burden of disease and results in high healthcare and economic costs. Heavy alcohol misuse leads to alcohol-related liver disease, which is responsible for a significant proportion of alcohol-attributable deaths globally. Other than reducing alcohol consumption, there are currently no effective treatments for alcohol-related liver disease. Oxidative stress refers to an imbalance in the production and elimination of reactive oxygen species and antioxidants. It plays important roles in several aspects of alcohol-related liver disease pathogenesis. Here, we review how chronic alcohol use results in oxidative stress through increased metabolism via the cytochrome P450 2E1 system producing reactive oxygen species, acetaldehyde and protein and DNA adducts. These trigger inflammatory signaling pathways within the liver leading to expression of pro-inflammatory mediators causing hepatocyte apoptosis and necrosis. Reactive oxygen species exposure also results in mitochondrial stress within hepatocytes causing structural and functional dysregulation of mitochondria and upregulating apoptotic signaling. There is also evidence that oxidative stress as well as the direct effect of alcohol influences epigenetic regulation. Increased global histone methylation and acetylation and specific histone acetylation inhibits antioxidant responses and promotes expression of key pro-inflammatory genes. This review highlights aspects of the role of oxidative stress in disease pathogenesis that warrant further study including mitochondrial stress and epigenetic regulation. Improved understanding of these processes may identify novel targets for therapy.

Correlation between C-reactive Protein with Malondialdehyde in Systemic Lupus Erythematosus Patients

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by an inflammatory process. One of the inflammation markers that can be measured is C-reactive protein (CRP). Another indicator of inflammation is malondialdehyde (MDA), though it is still uncommon to be analyzed in SLE patients. The study looked for the MDA value and found a correlation with CRP. A cross-sectional study design with a correlative analytical was performed. CRP level data was taken from Hasan Sadikin lupus registry data, and MDA levels were analyzed from a bioarchive patient's serum. We collected the patients' data who had CRP level from Hasan Sadikin lupus registry and analysed MDA levels from the serum sample. MDA levels were analyzed using an ELISA method. The data obtained were analyzed using the Pearson correlation and Eta correlation test. The study involved 78 data patients as subjects. It was found that the median of CRP and MDA was 0.85 mg/l and 153.10 ng/ml, respectively. These results indicate that the CRP levels in SLE patients are still within normal limits. Statistical analysis showed no correlation between CRP and MDA level (r = 0.2, P > 0.05). Additionally, the correlation between CRP and MDA with organ involvement, such as lupus nephritis (LN), lupus cutaneous (LC), and lupus musculoskeletal (LM), showed no correlation (F_h < F_t). There is no correlation between CRP and MDA levels in SLE patients, and specific organ involvement of the disease does not affect the correlation.

Caution in studying and interpreting the lupus metabolome

Several metabolomics studies have shed substantial light on the pathophysiological pathways underlying multiple diseases including systemic lupus erythematosus (SLE). This review takes stock of our current understanding of this field. We compare, collate, and investigate the metabolites in SLE patients and healthy volunteers, as gleaned from published metabolomics studies on SLE. In the surveyed primary reports, serum or plasma samples from SLE patients and healthy controls were assayed using mass spectrometry or nuclear magnetic resonance spectroscopy, and metabolites differentiating SLE from controls were identified. Collectively, the circulating metabolome in SLE is characterized by reduced energy substrates from glycolysis, Krebs cycle, fatty acid β oxidation, and glucogenic and ketogenic amino acid metabolism; enhanced activity of the urea cycle; decreased long-chain fatty acids; increased medium-chain and free fatty acids; and augmented peroxidation and inflammation. However, these findings should be interpreted with caution because several of the same metabolic pathways are also significantly influenced by the medications commonly used in SLE patients, common co-morbidities, and other factors including smoking and diet. In particular, whereas the metabolic alterations relating to inflammation, oxidative stress, lipid peroxidation, and glutathione generation do not appear to be steroid-dependent, the other metabolic changes may in part be influenced by steroids. To conclude, metabolomics studies of SLE and other rheumatic diseases ought to factor in the potential contributions of confounders such as medications, co-morbidities, smoking, and diet.

A mechanistic study and review of volatile products from peroxidation of unsaturated fatty acids: an aid to understanding the origins of volatile organic compounds from the human body

The assessment of volatile compounds (VOCs) for disease diagnosis is a growing area of research. There is a need to provide hard evidence i.e. biochemical routes, to justify putative VOC biomarkers, as in many cases this remains uncertain, which weakens their authenticity. Recently reports of volatile hydrocarbons and or aldehydes in bodily fluids and breath have been attributed to oxidative stress, although as discussed here, fewer compounds have been reported than expected from a mechanistic examination. Oxidative stress can result from many disease states which produce inflammation, and a better understanding of the interconnection between oxidative stress and the release of VOCs from target diseased and healthy organs could greatly help diagnoses. It is generally considered that oxidation of unsaturated fatty acids are a major source of these VOCs. An investigation listing the many possible volatile oxidation products has not been undertaken. This is described here using a mechanistic analysis (based on the literature) of the compounds derived from molecular cleavage and the results compared with a recent review of all the VOCs emanating from the human body, which satisfactorily explains the presence of at least 100 VOCs. Six important unsaturated fatty acids, oleic, palmitoleic, linoleic, linolenic, arachidonic, and cervonic acids have been shown to be capable of producing up to 18 n+6 unique breakdown products (where n = the number of alkene double bonds in the fatty acid hydrocarbon chain), in total 299 compounds. In many cases these have not been reported. We suggest several reasons for this: these VOCs have not been expected, so researchers are not looking for them and importantly some are not present in the mass spectral libraries, or they are too low a concentration to have been detected, or are not present. Furthermore a theoretical explanation for the origins of branched aldehydes and other compounds arising from bacterial oxidative metabolism of unsaturated fatty acids are described.

Impact of endogenous stress on albumin structure in systemic lupus erythematosus (SLE) patients

Systemic lupus erythematosus (SLE) is an inflammatory, autoimmune disorder of unknown etiology. The inflammatory stress in SLE patients may modify macromolecules and produce structural/functional abnormalities. The present study is aimed at examining the consequences of stresses on the structure of albumin in SLE patients. Albumin was isolated from the sera of SLE/healthy subjects. Multiple physicochemical techniques were used to elucidate, structure of albumin. Advanced glycation end products in SLE patients' albumin were identified by the AGE specific fluorescence. Quenching of tryptophan, tyrosine fluorescence and surface protein hydrophobicity was observed in SLE patients' albumin. Protein-bound carbonyls were elevated while free thiol, lysine, arginine, and alpha helicity was found to be decreased in SLE albumin. Furthermore, changes in the secondary structure of SLE albumin were observed as shift in the position of amide I/II bands. Functionality of SLE albumin was also compromised as its cobalt-binding ability was substantially declined. Adduction of moieties was detected by dynamic light scattering (DLS) and confirmed by matrix assisted laser desorption/ionization. DLS, thioflavin T and transmission electron microscopy results confirmed aggregates in SLE patients' albumin. This study may be helpful in understanding the role of modified albumin in the cofounding pathologies associated with SLE.

Maternal Undernourishment in Guinea Pigs Leads to Fetal Growth Restriction with Increased Hypoxic Cells and Oxidative Stress in the Brain

BACKGROUND

We determined whether maternal nutrient restriction (MNR) in guinea pigs leading to fetal growth restriction (FGR) impacts markers for brain hypoxia and oxidative stress.

METHODS

Guinea pigs were fed ad libitum (control) or 70% of the control diet before pregnancy, switching to 90% at mid-pregnancy (MNR). Near term, hypoxyprobe-1 (HP-1) was injected into pregnant sows. Fetuses were then necropsied and brain tissues were processed for HP-1 (hypoxia marker) and 4HNE, 8-OHdG, and 3-nitrotyrosine (oxidative stress markers) immunoreactivity (IR).

RESULTS

FGR-MNR fetal and brain weights were decreased 38 and 12%, respectively, with brain/fetal weights thereby increased 45% as a measure of brain sparing, and more so in males than females. FGR-MNR HP-1 IR was increased in most of the brain regions studied, and more so in males than females, while 4HNE and 8-OHdG IR were increased in select brain regions, but with no sex differences.

CONCLUSIONS

Chronic hypoxia is likely to be an important signaling mechanism in the FGR brain, but with males showing more hypoxia than females. This may involve sex differences in adaptive decreases in growth and normalizing of oxygen, with implications for sex-specific alterations in brain development and risk for later neuropsychiatric disorder.

Increased Expression of EZH2 Is Mediated by Higher Glycolysis and mTORC1 Activation in Lupus CD4+ T Cells

Objective:

EZH2 is overexpressed in CD4⁺ T cells from patients with systemic lupus erythematosus (SLE). Increased disease activity in SLE patients is associated with a proinflammatory epigenetic shift in naïve CD4⁺ T cells, likely mediated by EZH2. Here we aim to understand the upstream mechanisms underlying EZH2 overexpression in SLE CD4⁺ T cells.

Methods:

Naïve CD4⁺ T cells were isolated from SLE patients and then stimulated with anti-CD3/anti-CD28. qPCR and Western blotting were used to measure mRNA and protein expression levels, respectively. 2-Deoxy-d-glucose (2-DG) was used to inhibit glycolysis. mTORC1 signaling was inhibited using rapamycin. Oxidative stress was induced by H₂O₂.

Results:

Because glycolysis is increased in SLE CD4⁺ T cells and glycolysis regulates miR-26a and miR-101, which target EZH2, we examined the effect of inhibiting glycolysis on EZH2 expression. 2-DG significantly inhibited EZH2 expression in SLE CD4⁺ T cells. In addition, 2-DG restored the expression of miR-26a and miR-101, suggesting that suppression of EZH2 by 2-DG occurs at the post-transcriptional level. Because mTORC1 is activated in SLE CD4⁺ T cells in part due to increased oxidative stress, and mTORC1 activation increases glycolysis, we hypothesized that mTORC1 mediates increased EZH2 expression. Indeed, inhibiting mTORC1 increased miR-26a and miR-101 and suppressed EZH2 expression in SLE CD4⁺ T cells. Further, H₂O₂ treatment increased EZH2 expression, however, this effect appears to be independent of miR-26a and miR-101.

Conclusion:

Increased EZH2 is mediated by activation of mTORC1 and increased glycolysis in SLE CD4⁺ T cells. Therapeutic effects from inhibiting mTOR or glycolysis in SLE might be in part mediated by suppression of EZH2.

10-gingerol induces oxidative stress through HTR1A in cumulus cells: in-vitro and in-silico studies

Background We investigated whether 10-gingerol is able to induce oxidative stress in cumulus cells. Methods For the in-vitro research, we used a cumulus cell culture in M199, containing 10-gingerol in various concentrations (0, 12, 16, and 20 µM), and detected oxidative stress through superoxide dismutase (SOD) activity and malondialdehyde (MDA) concentrations, with incubation periods of 24, 48, 72, and 96 h. The obtained results were confirmed by in-silico studies. Results The in-vitro data revealed that SOD activity and MDA concentration increased with increasing incubation periods: SOD activity at 0 µM (1.39 ± 0.24i), 12 µM (16.42 ± 0.35ab), 16 µM (17.28 ± 0.55ab), 20 µM (17.81 ± 0.12a), with a contribution of 71.1%. MDA concentration at 0 µM (17.82 ± 1.39 l), 12 µM (72.99 ± 0.31c), 16 µM (79.77 ± 4.19b), 20 µM (85.07 ± 2.57a), with a contribution of 73.1%. Based on this, the in-silico data uncovered that 10-gingerol induces oxidative stress in cumulus cells by inhibiting HTR1A functions and inactivating GSK3B and AKT-1. Conclusions 10-gingerol induces oxidative stress in cumulus cells through enhancing SOD activity and MDA concentration by inhibiting HTR1A functions and inactivating GSK3B and AKT-1.

Oxidative stress enhances the immune response to oxidatively modified catalase enzyme in patients with Graves' disease

BACKGROUND

Oxidative stress is associated with several autoimmune disorders and oxidative modification of proteins that may result in autoimmune response. This study aims to evaluate the catalase (CAT) activity and the autoimmune response against the native CAT and the oxidatively modified enzyme in patients with Graves' disease (GD) and healthy controls in a comparative way.

METHODS

The CAT activity was evaluated via spectrophotometric method. Using enzyme-linked immunosorbent assay, the reactivities of autoantibody toward native, malondialdehyde (MDA) and hydrogen peroxide (H2 O2 ) modified CAT were evaluated in plasmas of patients and controls.

RESULTS

Reduced CAT activity was found in patients compared with controls (P < .05). It was proved that levels of IgG antibodies against MDA-modified CAT were higher than against unmodified ones (P < .001). No changes were found for the reactivities to H2 O2 -modified CAT. Positive correlation was found between the reactivity to MDA-modified CAT and the triiodothyronine level (P < .001, r = .6).

CONCLUSION

Our findings incriminate the MDA in the autoantibodies reactivity to oxidatively modified CAT leading to a disturbed oxidative profile and/or the progression of GD pathology.

Systemic Lupus Erythematosus and Endothelial Dysfunction: A Close Relationship

BACKGROUND

Accelerated atherosclerosis, responsible for premature cardiovascular disease, has been estimated to develop or progress in 10% of systemic lupus erythematosus (SLE) patients each year and to be 6-fold more frequent in SLE compared with the general population. The mechanisms underlying accelerated atherosclerosis in SLE are complex and involve classical and "non-classical" cardiovascular risk factors. Subclinical and disseminated atherosclerosis is associated with endothelial dysfunction and arterial stiffness.

OBJECTIVE

The aim of this review is to analyze the association between SLE and endothelial dysfunction.

RESULTS AND CONCLUSION

Different mechanisms have been proposed to explain the prevalence of endothelial dysfunction in SLE, which are briefly reported in this review: impaired clearance of apoptotic cells, oxidative stress markers, B cell activation with different circulating autoantibodies, different subtypes of T lymphocytes, cytokine cascade. Several studies and meta-analyses show a significant trend towards a prevalence of subclinical accelerated atherosclerosis in patients with SLE compared with healthy controls, since childhood. Based on general considerations, we suggest a multidisciplinary management to assess endothelial dysfunction at the diagnosis of the disease and to periodically search for and treat the traditional cardiovascular risk factors. Prospective studies are needed to confirm the benefits of this management.

Signaling Response to Transient Redox Stress in Human Isolated T Cells: Molecular Sensor Role of Syk Kinase and Functional Involvement of IL2 Receptor and L-Selectine

Reactive oxygen species (ROS) are central effectors of inflammation and play a key role in cell signaling. Previous reports have described an association between oxidative events and the modulation of innate immunity. However, the role of redox signaling in adaptive immunity is still not well understood. This work is based on a novel investigation of diamide, a specific oxidant of sulfhydryl groups, and it is the first performed in purified T cell tyrosine phosphorylation signaling. Our data show that ex vivo T cells respond to –SH group oxidation with a distinctive tyrosine phosphorylation response and that these events elicit specific cellular responses. The expression of two essential T-cell receptors, CD25 and CD62L, and T-cell cytokine release is also affected in a specific way. Experiments with Syk inhibitors indicate a major contribution of this kinase in these phenomena. This pilot work confirms the presence of crosstalk between oxidation of cysteine residues and tyrosine phosphorylation changes, resulting in a series of functional events in freshly isolated T cells. Our experiments show a novel role of Syk inhibitors in applying their anti-inflammatory action through the inhibition of a ROS-generated reaction.

High-Density Lipoprotein in Lupus: Disease Biomarkers and Potential Therapeutic Strategy

Systemic lupus erythematosus (SLE) patients exhibit accelerated development of atherosclerosis and increased incidents of cardiovascular disease (CVD) that cannot be explained by traditional risk factors alone. Accumulating evidence suggests that reduced levels of high-density lipoproteins (HDLs), along with altered HDL composition and function, may contribute to the accelerated atherosclerosis in SLE patients. Normally, HDLs play various atheroprotective roles through facilitating cholesterol efflux, inhibiting vascular inflammation, and scavenging oxidative species. However, systemic inflammation, oxidative stress, and autoimmunity in SLE patients induce changes in HDL size distribution and proteomic and lipidomic signatures. These compositional changes in HDLs result in the formation of proinflammatory, dysfunctional HDL. These lupus-altered HDLs have impaired antiatherogenic function with reduced cholesterol efflux capacities, impaired antioxidation abilities, and diminished antiinflammatory properties. In fact, dysfunctional HDL may promote atherogenesis by inducing inflammation. Thus, dysfunctional HDLs could be an important biomarker of accelerated atherosclerosis in lupus. Additionally, HDL-targeted therapies, especially infusion of reconstituted HDLs, may serve as a potential therapeutic intervention for SLE patients with CVD.

Detection by Flow Cytometry of Anti-DNA Autoantibodies and Circulating DNA Immune Complexes in Lupus Erythematosus

A new method for the detection by flow cytometry of anti-double-stranded DNA antibodies and of circulating immune complexes (IC) containing endogenous DNA (IC-eDNA) is described. From each serum sample, two samples were taken, one was used to detect IC-eDNA. The other to detect anti-DNA antibodies was incubated with calf thymus DNA. ICs were isolated by polyethylene glycol precipitation or by cryoprecipitation, after which immunoglobulins were labeled with FITC-conjugated anti-human globulin. Serum samples from 63 systemic lupus erythematosus (SLE) patients, 32 incomplete lupus, and 87 control patients were tested. Detection of anti-dsDNA antibodies by flow cytometry had a diagnostic sensitivity and specificity almost comparable to routine tests, the fluorescent enzyme immunoassay EliA™-dsDNA test, and the ultrasensitive Crithidia luciliae indirect immunofluorescence test. In 21 (33%) out of 63 SLE serum samples, IC-eDNA was detected. In these samples, free anti-dsDNA antibodies were hardly detectable or undetectable by flow cytometry or by routine tests. When anti-DNA antibodies are neutralized by endogenous DNA and can no longer be detected by routine tests, the serologic diagnosis and the follow-up of relapses in patients with SLE is compromised. To overcome this obstacle, we propose an accessible solution: the detection of circulating IC-eDNA by flow cytometry.

Systemic Lupus Erythematosus: Pathogenesis at the Functional Limit of Redox Homeostasis

Systemic lupus erythematosus (SLE) is a disease characterized by the production of autoreactive antibodies and cytokines, which are thought to have a major role in disease activity and progression. Immune system exposure to excessive amounts of autoantigens that are not efficiently removed is reported to play a significant role in the generation of autoantibodies and the pathogenesis of SLE. While several mechanisms of cell death-based autoantigenic exposure and compromised autoantigen removal have been described in relation to disease onset, a significant association with the development of SLE can be attributed to increased apoptosis and impaired phagocytosis of apoptotic cells. Both apoptosis and impaired phagocytosis can be caused by hydrogen peroxide whose cellular production is enhanced by exposure to endogenous hormones or environmental chemicals, which have been implicated in the pathogenesis of SLE. Hydrogen peroxide can cause lymphocyte apoptosis and glutathione depletion, both of which are associated with the severity of SLE. The cellular accumulation of hydrogen peroxide is facilitated by the myriad of stimuli causing increased cellular bioenergetic activity that enhances metabolic production of this toxic oxidizing agent such as emotional stress and infection, which are recognized SLE exacerbating factors. When combined with impaired cellular hydrogen peroxide removal caused by xenobiotics and genetically compromised hydrogen peroxide elimination due to enzymatic polymorphic variation, a mechanism for cellular accumulation of hydrogen peroxide emerges, leading to hydrogen peroxide-induced apoptosis and impaired phagocytosis, enhanced autoantigen exposure, formation of autoantibodies, and development of SLE.

Combinatorial therapeutic effect of resveratrol and piperine on murine model of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a chronic multi-system inflammatory disease associated with autoantibody formation. Clinical management of lupus is associated with multiple adverse events. Resveratrol is a phytoalexin with several pharmacological properties. This study aimed to evaluate the combinatorial effect of resveratrol (25 mg/kg and 50 mg/kg) and its bio-enhancer piperine (1/10th dose of resveratrol) on pristane-induced SLE murine model. Mice were injected with 0.5 ml of pristane and after 2 months they were orally dosed with resveratrol combinations for 4 months. Determined by indirect immunofluorescence, resveratrol was unable to abrogate autoantibody formation. The increased IFN-α, IL-6 and TNF-α was mitigated by low dose of resveratrol and piperine (RP-1). None of the doses regulated the increase in nitric oxide. Lipogranulomas associated with injected pristane were not observed after RP-1 and high dose of resveratrol (Res-2) treatment. Lupus mice witnessed IgG and IgM immune complexes by direct immunofluorescence assay and associated histopathological observations in kidneys, liver, lung, spleen and skin. None of the treatment regimens were able to regulate the manifestations observed in spleen and skin. RP-1 and Res-2 proved beneficial in kidney, liver and lungs and were able to ameliorate lupus associated manifestations. Renal manifestations (proteinuria and decreased creatinine in urine) were successfully mitigated by RP-1 and Res-2 and high dose combination of resveratrol and piperine. Oxidative stress (reactive oxygen species by flowcytometry and catalase, superoxide dismutase, glutathione peroxidase, reduced glutathione and lipid peroxidation by biochemical analysis) was evident by pristane injection. These were regulated by different doses of resveratrol alone and in combination with piperine. Hence, resveratrol when used in combination with piperine successfully reduces some measures of morbidity with little or no effect on mortality associated with lupus.

Immunometabolic disorders in the pathogenesis of systemic lupus erythematosus

Systemic lupus erythematosus is a chronic autoimmune disease connected with complex and unclear disorders of the immune system, which causes inflammation of body tissues and internal organs. It leads to the formation of anti-nuclear antibodies (ANA) and immune complexes. Numerous immune system disorders and dysfunctions in the biochemical processes can occur in the course of the disease, and a wide range of abnormalities associated with cellular respiratory processes and mitochondrial function have been documented. The following paper presents the current understanding of the contribution of these disorders to the pathogenesis of lupus.

Blue and Long-Wave Ultraviolet Light Induce in vitro Neutrophil Extracellular Trap (NET) Formation

Neutrophil Extracellular Traps (NETs) are produced by neutrophilic granulocytes and consist of decondensed chromatin decorated with antimicrobial peptides. They defend the organism against intruders and are released upon various stimuli including pathogens, mediators of inflammation, or chemical triggers. NET formation is also involved in inflammatory, cardiovascular, malignant diseases, and autoimmune disorders like rheumatoid arthritis, psoriasis, or systemic lupus erythematosus (SLE). In many autoimmune diseases like SLE or dermatomyositis, light of the ultraviolet-visible (UV-VIS) spectrum is well-known to trigger and aggravate disease severity. However, the underlying connection between NET formation, light exposure, and disease exacerbation remains elusive. We studied the effect of UVA (375 nm), blue (470 nm) and green (565 nm) light on NETosis in human neutrophils ex vivo. Our results show a dose- and wavelength-dependent induction of NETosis. Light-induced NETosis depended on the generation of extracellular reactive oxygen species (ROS) induced by riboflavin excitation and its subsequent reaction with tryptophan. The light-induced NETosis required both neutrophil elastase (NE) as well as myeloperoxidase (MPO) activation and induced histone citrullination. These findings suggest that NET formation as a response to light could be the hitherto missing link between elevated susceptibility to NET formation in autoimmune patients and photosensitivity for example in SLE and dermatomyositis patients. This novel connection could provide a clue for a deeper understanding of light-sensitive diseases in general and for the development of new pharmacological strategies to avoid disease exacerbation upon light exposure.

Cross-Talk between Mitochondrial Dysfunction-Provoked Oxidative Stress and Aberrant Noncoding RNA Expression in the Pathogenesis and Pathophysiology of SLE

Systemic lupus erythematosus (SLE) is a prototype of systemic autoimmune disease involving almost every organ. Polygenic predisposition and complicated epigenetic regulations are the upstream factors to elicit its development. Mitochondrial dysfunction-provoked oxidative stress may also play a crucial role in it. Classical epigenetic regulations of gene expression may include DNA methylation/acetylation and histone modification. Recent investigations have revealed that intracellular and extracellular (exosomal) noncoding RNAs (ncRNAs), including microRNAs (miRs), and long noncoding RNAs (lncRNAs), are the key molecules for post-transcriptional regulation of messenger (m)RNA expression. Oxidative and nitrosative stresses originating from mitochondrial dysfunctions could become the pathological biosignatures for increased cell apoptosis/necrosis, nonhyperglycemic metabolic syndrome, multiple neoantigen formation, and immune dysregulation in patients with SLE. Recently, many authors noted that the cross-talk between oxidative stress and ncRNAs can trigger and perpetuate autoimmune reactions in patients with SLE. Intracellular interactions between miR and lncRNAs as well as extracellular exosomal ncRNA communication to and fro between remote cells/tissues via plasma or other body fluids also occur in the body. The urinary exosomal ncRNAs can now represent biosignatures for lupus nephritis. Herein, we’ll briefly review and discuss the cross-talk between excessive oxidative/nitrosative stress induced by mitochondrial dysfunction in tissues/cells and ncRNAs, as well as the prospect of antioxidant therapy in patients with SLE.

Establishment and characterization of induced pluripotent stem cells (iPSCs) from central nervous system lupus erythematosus

Involvement of the central nervous system (CNS) is an uncommon feature in systemic lupus erythematosus (SLE), making diagnosis rather difficult and challenging due to the poor specificity of neuropathic symptoms and neurological symptoms. In this work, we used human‐induced pluripotent stem cells (hiPSCs) derived from CNS‐SLE patient, with the aim to dissect the molecular insights underlying the disease by gene expression analysis and modulation of implicated pathways. CNS‐SLE‐derived hiPSCs allowed us to provide evidence of Erk and Akt pathways involvement and to identify a novel cohort of potential biomarkers, namely CHCHD2, IDO1, S100A10, EPHA4 and LEFTY1, never reported so far. We further extended the study analysing a panel of oxidative stress‐related miRNAs and demonstrated, under normal or stress conditions, a strong dysregulation of several miRNAs in CNS‐SLE‐derived compared to control hiPSCs. In conclusion, we provide evidence that iPSCs reprogrammed from CNS‐SLE patient are a powerful useful tool to investigate the molecular mechanisms underlying the disease and to eventually develop innovative therapeutic approaches.

Homozygous damaging SOD2 variant causes lethal neonatal dilated cardiomyopathy

BACKGROUND

Idiopathic dilated cardiomyopathy (DCM) is recognised to be a heritable disorder, yet clinical genetic testing does not produce a diagnosis in >50% of paediatric patients. Identifying a genetic cause is crucial because this knowledge can affect management options, cardiac surveillance in relatives and reproductive decision-making. In this study, we sought to identify the underlying genetic defect in a patient born to consanguineous parents with rapidly progressive DCM that led to death in early infancy.

METHODS AND RESULTS

Exome sequencing revealed a potentially pathogenic, homozygous missense variant, c.542G>T, p.(Gly181Val), in SOD2. This gene encodes superoxide dismutase 2 (SOD2) or manganese-superoxide dismutase, a mitochondrial matrix protein that scavenges oxygen radicals produced by oxidation-reduction and electron transport reactions occurring in mitochondria via conversion of superoxide anion (O₂ ^-·) into H₂O₂. Measurement of hydroethidine oxidation showed a significant increase in O₂ ^-· levels in the patient's skin fibroblasts, as compared with controls, and this was paralleled by reduced catalytic activity of SOD2 in patient fibroblasts and muscle. Lentiviral complementation experiments demonstrated that mitochondrial SOD2 activity could be completely restored on transduction with wild type SOD2.

CONCLUSION

Our results provide evidence that defective SOD2 may lead to toxic increases in the levels of damaging oxygen radicals in the neonatal heart, which can result in rapidly developing heart failure and death. We propose SOD2 as a novel nuclear-encoded mitochondrial protein involved in severe human neonatal cardiomyopathy, thus expanding the wide range of genetic factors involved in paediatric cardiomyopathies.

Edaravone, a free radical scavenger, protects against ferroptotic cell death in vitro

Ferroptosis is characterized by an iron-dependent cell death with increased lipid peroxidation and is typically induced by either a decrease in glutathione (GSH) levels due to an insufficient supply of cysteine (Cys) or the inhibition of phospholipid hydroperoxide glutathione peroxidase (Gpx4). While lipid peroxides are the direct trigger for ferroptosis, the issue of how radical species involve in the cytocidal process remains unclear. To gain insights into this issue, we employed edaravone, a free radical scavenger that is clinically approved for the treatment of acute ischemic strokes and amyotrophic lateral sclerosis (ALS), against ferroptotic cell death caused by various situations, notably under cystine deprivation. We initially investigated the effects of edaravone on ferroptosis in mouse hepatoma Hepa 1-6 cells cultivated in cystine-free medium and found that edaravone largely suppressed ferroptosis. Ferroptosis that was induced in the cells by the use of inhibitors for xCT or Gpx4 was also suppressed by edaravone. Moreover, edaravone also suppressed ferroptosis in xCT-knockout mouse-derived embryonic fibroblasts, which usually die in normal cultivating conditions due to the depletion of intracellular Cys and GSH. Although the edaravone treatment had no effects on the intracellular levels of Cys and GSH, both of which remained low in Hepa 1-6 cells under conditions of cystine deprivation, the causative factors for ferroptosis, including ferrous iron and lipid peroxide levels, were significantly suppressed. Collectively, these results indicate that radical species produced at the initial stage of the cytocidal process under Cys-deprived conditions trigger ferroptosis and scavenging these radicals by edaravone represents a promising treatment.

Altered Tregs and oxidative stress in pregnancy associated lupus

AIM

SLE is a systemic autoimmune disease generally affecting woman in the reproductive age. It is associated with an altered level of Tregs and oxidative stress while an increase in Tregs, and different antioxidant mechanisms to combat oxidative stress are essential for successful pregnancy. Hence, this study aims to determine the level of CD4⁺ and CD8⁺ Tregs and oxidative stress in pregnant lupus patients.

METHODS

Ten healthy and 10 pregnant lupus volunteers from the North Indian population, within the age group of 20-30 years were enrolled in the study. All the patients were non-smokers, non-alcoholics and were not associated or undergoing therapy for any other disease. They had a SLEDAI of 37.4 ± 7.32 with 5.2 ± 1.93 years of disease duration. Oxidative stress was determined by measuring the enzyme activity of anti-oxidant enzymes (catalase, superoxide dismutase and glutathione peroxidase) and the level of reduced glutathione and lipids peroxidised, spectrophotometrically. Flowcytometry was performed for immunophenotyping to determine CD8⁺ and CD4⁺ Tregs.

RESULTS

Elevated CD8⁺ Tregs and diminished CD4⁺ Tregs were observed in pregnant lupus patients. Oxidative stress was significantly increased as the activities of anti-oxidant enzymes and level of reduced glutathione was considerably diminished. There was a substantial increase in the amount of lipids peroxidised.

CONCLUSION

Pregnant lupus patients undergo considerable level of oxidative stress in comparison to healthy pregnant woman. The decreased level of CD4⁺ Tregs and an increase in CD8⁺ Tregs might be another important factor responsible for pregnancy associated complications. Hence, lupus leads to alterations in the necessary conditions for a successful pregnancy, which might eventually cause higher mortality, morbidity and associated complications.

Molecular and Cellular Bases of Immunosenescence, Inflammation, and Cardiovascular Complications Mimicking "Inflammaging" in Patients with Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is an archetype of systemic autoimmune disease, characterized by the presence of diverse autoantibodies and chronic inflammation. There are multiple factors involved in lupus pathogenesis, including genetic/epigenetic predisposition, sexual hormone imbalance, environmental stimulants, mental/psychological stresses, and undefined events. Recently, many authors noted that "inflammaging", consisting of immunosenescence and inflammation, is a common feature in aging people and patients with SLE. It is conceivable that chronic oxidative stresses originating from mitochondrial dysfunction, defective bioenergetics, abnormal immunometabolism, and premature telomere erosion may accelerate immune cell senescence in patients with SLE. The mitochondrial dysfunctions in SLE have been extensively investigated in recent years. The molecular basis of normoglycemic metabolic syndrome has been found to be relevant to the production of advanced glycosylated and nitrosative end products. Besides, immunosenescence, autoimmunity, endothelial cell damage, and decreased tissue regeneration could be the results of premature telomere erosion in patients with SLE. Herein, the molecular and cellular bases of inflammaging and cardiovascular complications in SLE patients will be extensively reviewed from the aspects of mitochondrial dysfunctions, abnormal bioenergetics/immunometabolism, and telomere/telomerase disequilibrium.

Oxidative stress and vitamin D receptor BsmI gene polymorphism in Egyptian children with systemic lupus erythematosus: a single center study

Systemic lupus erythematosus (SLE) is an autoimmune disease with unknown exact etiology. Vitamin D receptor gene ( VDR) and oxidative stress play important roles in the pathogenesis of SLE. Here we investigated the genotypes and allelic frequencies of VDR BsmI polymorphism as well as their relationship with oxidative stress markers in Egyptian SLE children. We conducted a cross-sectional comparative study at Mansoura University Children's Hospital, Egypt from 2014 to 2018 including 100 SLE children and 100 controls. We investigated both groups for VDR BsmI polymorphism using polymerase chain reaction. Oxidative stress was assessed using malondialdehyde, glutathione S-transferase, superoxide dismutase, catalase and total antioxidant capacity. BB genotype frequency was found to be significantly higher in the SLE group ( p = 0.04, odds ratio (95% confidence interval) = 2.5 (1.01–5.9)). However, VDR B allele and b allele showed insignificant differences between SLE patients and controls ( p = 0.36, odds ratio (95% confidence interval) = 1.2 (0.8–1.8)). Lower levels of glutathione S-transferase, superoxide dismutase and total antioxidant capacity were found in the SLE group with statistically significant differences as regards glutathione S-transferase and superoxide dismutase ( p < 0.001). Serum malondialdehyde and catalase levels were significantly higher in the SLE group ( p < 0.001). No significant differences were found between VDR BsmI polymorphism (genotypes and alleles) and oxidative stress markers in the SLE group. In conclusion, BB genotype of VDR BsmI polymorphism is associated with an increased risk of SLE among Egyptian children. Oxidative stress may contribute in pathogenesis of SLE but is not associated with VDR BsmI polymorphism.

Human and Murine Evidence for Mechanisms Driving Autoimmune Photosensitivity

Ultraviolet (UV) light is an important environmental trigger for systemic lupus erythematosus (SLE) patients, yet the mechanisms by which UV light impacts disease are not fully known. This review covers evidence in both human and murine systems for the impacts of UV light on DNA damage, apoptosis, autoantigen exposure, cytokine production, inflammatory cell recruitment, and systemic flare induction. In addition, the role of the circadian clock is discussed. Evidence is compared in healthy individuals and SLE patients as well as in wild-type and lupus-prone mice. Further research is needed into the effects of UV light on cutaneous and systemic immune responses to understand how to prevent UV-light mediated lupus flares.

Stimulatory TSH-Receptor Antibodies and Oxidative Stress in Graves Disease

CONTEXT

We hypothesized that TSH-receptor (TSHR) stimulating antibodies (TSAbs) are involved in oxidative stress mechanisms in patients with Graves disease (GD).

METHODS

Nicotinamide adenine dinucleotide phosphate oxidase, isoform 2 (NOX2); oxidative parameters; and oxidative burst were measured in serum, urine, and whole blood from patients with GD and control subjects. Superoxide production was investigated in human embryonic kidney (HEK)-293 cells stably overexpressing the TSHR. Lipid peroxidation was determined by immunodot-blot analysis for protein-bound 4-hydroxy-2-nonenal (4-HNE) in human primary thyrocytes and HEK-293-TSHR cells.

RESULTS

Serum NOX2 levels were markedly higher in hyperthyroid untreated vs euthyroid treated patients with GD, hyperthyroid patients with toxic nodular goiter, and euthyroid healthy control subjects (all P < 0.0001). Urine oxidative parameters were increased in patients with GD vs patients with toxic goiter (P < 0.01) and/or control subjects (P < 0.001). The maximum of the zymosan A- and phorbol 12,13-dibutyrate-induced respiratory burst of leukocytes was 1.5-fold higher in whole blood from hyperthyroid patients with GD compared with control subjects (P < 0.001 and P < 0.05). Monoclonal M22 TSAbs stimulated cAMP (HEK cells) in a dose-dependent manner. M22 (P = 0.0082), bovine TSH (P = 0.0028), and sera of hyperthyroid patients with GD (P < 0.05) increased superoxide-specific 2-hydroxyethidium levels in HEK-293 TSHR cells after 48-hour incubation vs control subjects. In contrast, triiodothyronine (T3) did not affect reactive oxygen species (ROS) production. In primary thyrocytes, the 4-HNE marker was higher in patients with GD vs control subjects at 6 and 48 hours (P = 0.02 and P = 0.04, respectively). Further, after 48-hour incubation of HEK-293 TSHR cells with patient sera, 4-HNE was higher in patients with untreated GD compared with control subjects (P < 0.05).

CONCLUSIONS

Monoclonal M22 and polyclonal serum TSAbs augment ROS generation and/or induce lipid peroxidation.