Interaction between glutathione and apoptosis in systemic lupus erythematosus

Potential therapies targeting metabolic pathways in systemic lupus erythematosus

The pathophysiology of systemic lupus erythematosus (SLE) is multifactorial and involves alterations in metabolic pathways, including glycolysis, lipid metabolism, amino acid metabolism, and mitochondrial dysfunction. Increased glycolysis in SLE T cells, which is associated with elevated glucose transporter 1 expression, suggests targeting glucose transporters and hexokinase as potential treatments. Abnormalities in lipid metabolism, particularly in lipid rafts and enzymes, present new therapeutic targets. This review discusses how changes in glutaminolysis and tryptophan metabolism affect T-cell function, suggesting new therapeutic interventions, as well as mitochondrial dysfunction in SLE, which increases reactive oxygen species. The review also emphasizes that modulating metabolic pathways in immune cells is a promising approach for SLE treatment, and can facilitate personalized therapies based on individual metabolic profiles of patients with SLE. The review provides novel insights into strategies for managing SLE.

Methyltransferase Set7/9 as a Multifaceted Regulator of ROS Response

Reactive oxygen species (ROS) induce multiple signaling cascades in the cell and hence play an important role in the regulation of the cell's fate. ROS can cause irreversible damage to DNA and proteins resulting in cell death. Therefore, finely tuned regulatory mechanisms exist in evolutionarily diverse organisms that are aimed at the neutralization of ROS and its consequences with respect to cellular damage. The SET domain-containing lysine methyltransferase Set7/9 (KMT7, SETD7, SET7, SET9) post-translationally modifies several histones and non-histone proteins via monomethylation of the target lysines in a sequence-specific manner. In cellulo, the Set7/9-directed covalent modification of its substrates affects gene expression, cell cycle, energy metabolism, apoptosis, ROS, and DNA damage response. However, the in vivo role of Set7/9 remains enigmatic. In this review, we summarize the currently available information regarding the role of methyltransferase Set7/9 in the regulation of ROS-inducible molecular cascades in response to oxidative stress. We also highlight the in vivo importance of Set7/9 in ROS-related diseases.

New insights into the metabolism of Th17 cells

T helper 17 (Th17) cells are IL-17-producing CD4 T cells that play a crucial role in autoimmune diseases. IL-17 is a key cytokine for host protection against mucosal and skin infection but is also one of the major pathogenic cytokines. IL-1 and IL-23 are requisite for stimulating pathogenic Th17 cell differentiation and proliferation. Therapeutics targeting the IL-17/IL-23 pathway are widely used clinically for the treatment of autoimmune diseases. Besides IL-17, pathogenic Th17 cells produce granulocyte-macrophage colony-stimulating factor, tumor necrosis factor α, interferon γ, IL-21 and IL-22. However, Th17-targeted therapy has not yet been established. T cell metabolism orchestrates T cell survival, cell differentiation, epigenetic change and function and each T cell subset favors a particular metabolic pathway. Recent studies have provided novel insights into the role of T cell metabolism in the pathogenesis of autoimmune diseases. The current review focuses on the role of Th17 cell metabolism in autoimmune diseases, particularly glycolysis, amino acid metabolism, lipid metabolism, as well as the regulators of these processes, including mTORC1. Therapeutics targeting T cell metabolism in autoimmune diseases could serve as a possible treatment option for patients who are refractory to or unresponsive to conventional therapy.

Dysregulation of immunity in COVID-19 and SLE

The immune response plays a crucial role in preventing diseases, such as infections. There are two types of immune responses, specific and innate immunity, each of which consists of two components: cellular immunity and humoral immunity. Dysfunction in any immune system component increases the risk of developing certain diseases. Systemic lupus erythematosus (SLE), an autoimmune disease in the human body, develops an immune response against its own components. In these patients, due to underlying immune system disorders and receipt of immunosuppressive drugs, the susceptibility to infections is higher than in the general population and is the single largest cause of mortality in this group. COVID-19 infection, which first appeared in late 2019, has caused several concerns in patients with SLE. However, there is no strong proof of additional risk of developing COVID-19 in patients with SLE, and in some cases, studies have shown less severity of the disease in these individuals. This review paper discusses the immune disorders in SLE and COVID-19.

Metabolomics in Autoimmune Diseases: Focus on Rheumatoid Arthritis, Systemic Lupus Erythematous, and Multiple Sclerosis

The metabolomics approach represents the last downstream phenotype and is widely used in clinical studies and drug discovery. In this paper, we outline recent advances in the metabolomics research of autoimmune diseases (ADs) such as rheumatoid arthritis (RA), multiple sclerosis (MuS), and systemic lupus erythematosus (SLE). The newly discovered biomarkers and the metabolic mechanism studies for these ADs are described here. In addition, studies elucidating the metabolic mechanisms underlying these ADs are presented. Metabolomics has the potential to contribute to pharmacotherapy personalization; thus, we summarize the biomarker studies performed to predict the personalization of medicine and drug response.

Recent Updates and Advances in Winiwarter-Buerger Disease (Thromboangiitis Obliterans): Biomolecular Mechanisms, Diagnostics and Clinical Consequences

Thromboangiitis obliterans (TAO) or Buerger’s disease is a segmental inflammatory, thrombotic occlusive peripheral vascular disease with unknown aetiology that usually involves the medium and small-sized vessels of young male smokers. Due to its unknown aetiology and similarities with atherosclerosis and vasculitis, TAO diagnosis is still challenging. We aimed to review the status of biomolecular and laboratory para-clinical markers in TAO compared to atherosclerosis and vasculitis. We reported that, although some biomarkers might be common in TAO, atherosclerosis, and vasculitis, each disease occurs through a different pathway and, to our knowledge, there is no specific and definitive marker for differentiating TAO from atherosclerosis or vasculitis. Our review highlighted that pro-inflammatory and cell-mediated immunity cytokines, IL-33, HMGB1, neopterin, MMPs, ICAM1, complement components, fibrinogen, oxidative stress, NO levels, eNOS polymorphism, adrenalin and noradrenalin, lead, cadmium, and homocysteine are common markers. Nitric oxide, MPV, TLRs, MDA, ox-LDL, sST2, antioxidant system, autoantibodies, and type of infection are differential markers, whereas platelet and leukocyte count, haemoglobin, lipid profile, CRP, ESR, FBS, creatinine, d-dimer, hypercoagulation activity, as well as protein C and S are controversial markers. Finally, our study proposed diagnostic panels for laboratory differential diagnosis to be considered at first and in more advanced stages.

TRPM2 Non-Selective Cation Channels in Liver Injury Mediated by Reactive Oxygen Species

TRPM2 channels admit Ca²⁺ and Na⁺ across the plasma membrane and release Ca²⁺ and Zn²⁺ from lysosomes. Channel activation is initiated by reactive oxygen species (ROS), leading to a subsequent increase in ADP-ribose and the binding of ADP-ribose to an allosteric site in the cytosolic NUDT9 homology domain. In many animal cell types, Ca²⁺ entry via TRPM2 channels mediates ROS-initiated cell injury and death. The aim of this review is to summarise the current knowledge of the roles of TRPM2 and Ca²⁺ in the initiation and progression of chronic liver diseases and acute liver injury. Studies to date provide evidence that TRPM2-mediated Ca²⁺ entry contributes to drug-induced liver toxicity, ischemia–reperfusion injury, and the progression of non-alcoholic fatty liver disease to cirrhosis, fibrosis, and hepatocellular carcinoma. Of particular current interest are the steps involved in the activation of TRPM2 in hepatocytes following an increase in ROS, the downstream pathways activated by the resultant increase in intracellular Ca²⁺, and the chronology of these events. An apparent contradiction exists between these roles of TRPM2 and the role identified for ROS-activated TRPM2 in heart muscle and in some other cell types in promoting Ca²⁺-activated mitochondrial ATP synthesis and cell survival. Inhibition of TRPM2 by curcumin and other “natural” compounds offers an attractive strategy for inhibiting ROS-induced liver cell injury. In conclusion, while it has been established that ROS-initiated activation of TRPM2 contributes to both acute and chronic liver injury, considerable further research is needed to elucidate the mechanisms involved, and the conditions under which pharmacological inhibition of TRPM2 can be an effective clinical strategy to reduce ROS-initiated liver injury.

Amino Acid Metabolism in Lupus

T cell metabolism is central to cell proliferation, survival, differentiation, and aberrations have been linked to the pathophysiology of systemic autoimmune diseases. Besides glycolysis and fatty acid oxidation/synthesis, amino acid metabolism is also crucial in T cell metabolism. It appears that each T cell subset favors a unique metabolic process and that metabolic reprogramming changes cell fate. Here, we review the mechanisms whereby amino acid transport and metabolism affects T cell activation, differentiation and function in T cells in the prototype systemic autoimmune disease systemic lupus erythematosus. New insights in amino acid handling by T cells should guide approaches to correct T cell abnormalities and disease pathology.

Synthesis and Photoactivated Toxicity of 2-Thiophenylfuranocoumarin Induce Midgut Damage and Apoptosis in Aedes aegypti Larvae

Furanocoumarins are photoactive compounds derived from secondary plant metabolites. They possess many bioactivities, including antioxidative, anticancer, insecticidal, and bactericidal activities. Here, we designed a new scheme for synthesizing 2-arylfuranocoumarin derivatives by condensation, esterification, bromination, and Wittig reaction. We found that 2-thiophenylfuranocoumarin (Iy) had excellent photosensitive activity. Three Iy concentrations (LC₂₅, LC₅₀, and LC₇₅) were used to treat the fourth instar larvae of Aedes aegypti (A. aegypti). The photoactivated toxicity, sublethal dose, mitochondrial dysfunction, oxidative stress level, intestinal barrier dysfunction, and apoptosis were studied. The results showed that Iy induced reactive oxygen species (ROS) production in midgut cells under ultraviolet light. Ultrastructural analysis demonstrated that mitochondria were damaged, and the activities of related enzymes were inhibited. Ultimately, Iy exposure led to excessive ROS production followed by the inhibition of antioxidant enzymes, including SOD, CAT, GPx, and GR, which diminished ROS elimination and escalated oxidative stress in midgut cells, aggravating the degree of oxidative damage in these cells. Histopathological changes were observed in the midgut, which led to intestinal barrier dysfunction. When the elimination of ROS was blocked and it accumulated in cells, apoptosis-related genes, including AeDronc, AeCaspase7, and AeCaspase8, were induced and activated. In addition, Iy affected the growth and development of A. aegypti at sublethal concentrations, and there was an obvious post-lethal effect. Thus, we found that Iy caused midgut damage and apoptosis in A. aegypti larvae under ultraviolet light, which preliminarily revealed the mode of action of Iy in A. aegypti.

Oxidative Stress in Autoimmune Diseases: An Under Dealt Malice

Oxidative stress is the off-balance of antioxidants and free radicals. All kinds of diseases and disorders give rise to oxidative damage including autoimmune diseases. An autoimmune disorder is a pathological condition characterized by the breakdown of self-tolerance of the immune system in the body. Immunological processes against tissues and organs lead to enhanced oxidative stress and, in turn, misbalance of oxidative stress aggravates the pathobiology of the disease. Highly reactive nature of free radicals, for example hydroxyl and superoxide ions, alters DNA, protein, and lipids in the body which augment the pathologic processes of diseases. The damaged biomolecules are responsible for systemic complications and secondary disease co-morbidities. In this review, we discuss the role of oxidative stress in some incapacitating autoimmune diseases like Rheumatoid arthritis, Systemic Lupus Erythematosus, Type 1 Diabetes, and Multiple Sclerosis. Oxidative stress plays a central and course defining role in these diseases and it has become a necessity to study the pathological mechanism involved in oxidative stress to better understand and offer treatment holistically. Presently there are no clinically available parameters for measurement and treatment of pathological oxidative stress, therefore it requires intensive research. Probably, in the future, the discovery of easily detectable markers of oxidative stress can aid in the diagnosis, prognosis, and treatment of progressively destructive autoimmune diseases.

Regulatory effect of glutathione on treg/Th17 cell balance in allergic rhinitis patients through inhibiting intracellular autophagy

BACKGROUND

Glutathione is a potential therapy for systemic lupus erythematosus, but its role in allergic rhinitis (AR) has not been determined. This report probed into the actions of glutathione in AR, so as to supplement evidence for a therapeutical countermeasure for AR.

METHODS

In this study, peripheral blood mononuclear cells (PBMCs) of patients were extracted and processed with glutathione. PBMCs and nasal mucosa tissues were collected from AR mouse models treated with or without glutathione. The proportions of Th17/Treg cell markers and autophagy-related molecules in the nasal mucosa, PBMCs or Th17/Treg cells were assessed by quantitative real-time polymerase chain reaction (qRT-PCR), Western blot (WB) or flow cytometry analysis, and serum contents of related factors were analyzed by enzyme-linked immunosorbent assay (ELISA). Hematoxylin-eosin (HE) staining was applied to observe the thickness of mouse mucosa.

RESULTS

IL-17A, RORγt, Beclin1 and LC3-II/LC3-I levels were increased in AR patients, while Foxp3 and P62 were decreased. The serum contents of IL-17A and eosinophil cationic protein (ECP) in AR patients were elevated, but IL-10 level was reduced. In PBMCs of AR patients, the levels of IL-17A and LC3-II were increased, and the levels of Foxp3 and P62 were decreased, while these changes could be reversed by glutathione. In AR mouse models, glutathione could balance Th17/Treg cells, reduce autophagy, correct the levels of related cytokines in mouse serum, and shrunk mucosa thickness.

CONCLUSION

Glutathione could rescue the imbalance of Treg/Th17 cells by suppressing intracellular autophagy, which might be beneficial to the treatment of AR patients.

Single-nucleotide polymorphisms (SNPs) of antioxidant enzymes SOD2 and GSTP1 genes and SLE risk and severity in an Egyptian pediatric population

BACKGROUND

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease associated with increased oxidative stress that participates in immune dysregulation, and injury resulting in loss of immune tolerance and increased auto-antibody production. This study was designed to investigate the effects of genetic polymorphisms of the antioxidant enzymes genes that code for SOD2 (rs2758332) and GSTP1 (rs1695) on SLE risk and severity in Egyptian children and adolescents cohort from Delta region.

METHODS

The frequencies of these genes polymorphic variants were compared between 100 SLE children and adolescents and 100 healthy control subjects. Single-nucleotide polymorphisms (SNPs) of the two antioxidants were determined using TaqMan SNP genotyping assay.

RESULTS

Individuals with the TT and CT genotypes of rs2758332 in the SOD2 gene were of significant risk for SLE patients (OR = 1.831, 95% CI = 1.082-3.101, P = 0.024) and (OR = 1.864, 95% CI = 1.136-3.059, P = 0.014), respectively. Cases who have combined CT + TT genotype were of significant higher risk of SLE (OR = 1.851, 95% CI = 1.156 - 2.962, P = 0.010). While, they did not show any significant association between SOD2 genotypes or alleles with SLE clinical features. In case of the SNP rs1695 in the GSTP1 gene, no significant associations of genotypes or alleles with SLE risk or with SLE clinical features were detected.

CONCLUSIONS

This study among Egyptian children and adolescents showed a strong association of the SOD2 rs2758332 not GSTP1 rs1695 polymorphism with the risk of SLE disease.

Connection between the Gut Microbiome, Systemic Inflammation, Gut Permeability and FOXP3 Expression in Patients with Primary Sjögren's Syndrome

The aims of this study were to explore intestinal microbial composition and functionality in primary Sjögren’s syndrome (pSS) and to relate these findings to inflammation, permeability and the transcription factor Forkhead box protein P3 (FOXP3) gene expression in peripheral blood. The study included 19 pSS patients and 19 healthy controls matched for age, sex, and body mass index. Fecal bacterial DNA was extracted and analyzed by 16S rRNA sequencing using an Ion S5 platform followed by a bioinformatics analysis using Quantitative Insights into Microbial Ecology (QIIME II) and Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt). Our data suggest that the gut microbiota of pSS patients differs at both the taxonomic and functional levels with respect to healthy controls. The gut microbiota profile of our pSS patients was characterized by a lower diversity and richness and with Bacteroidetes dominating at the phylum level. The pSS patients had less beneficial or commensal butyrate-producing bacteria and a higher proportion of opportunistic pathogens with proinflammatory activity, which may impair intestinal barrier function and therefore contribute to inflammatory processes associated with pSS by increasing the production of proinflammatory cytokines and decreasing the release of the anti-inflammatory cytokine IL-10 and the peripheral FOXP3 mRNA expression, implicated in the development and function of regulatory T cells (Treg) cells. Further studies are needed to better understand the real impact of dysbiosis on the course of pSS and to conceive preventive or therapeutic strategies to counteract microbiome-driven inflammation.

Altered redox regulation by Nrf2-Keap1 system in dendritic cells of systemic lupus erythematosus patients

Systemic lupus erythematosus (SLE) is an autoimmune disorder associated with inflammation and multiple organ involvement. Individually, dendritic cells (DCs) and oxidative stress have been well discussed for their critical involvement in the pathogenesis of disease but the precise impact of oxidative stress on DCs in relation to SLE disease activity is yet to be scrutinized. Nuclear factor (erythroid-derived 2)-like 2 (Nrf2)/Kelch-like ECH-associated protein 1 (Keap1) pathway is the cellular mechanism to combat increased reactive oxygen species (ROS). The current study was framed in order to understand redox regulation in DCs along with an argument in context to disease activity. Here, 23 SLE patients along with 10 healthy controls were enrolled and disease activity was calculated as the recent change in SLEDAI score. We found the percentage of circulating plasmacytoid DCs (pDCs) was increased with an increase in disease activity. Altered DCs functionality along with disease activity was further supported with the differential concentration of Type I IFNs. The disease activity was positively associated with increased levels of ROS. A relevant reason for increased ROS was further explained with the decreased levels of transcription factor Nrf2. Hence, the present study suggests that SLE specific DCs displayed elevation in ROS and this outcome might be due to impaired free radical clearance by Nrf2. Correlation studies further established an association of disease activity with increased ROS, Type I IFNs levels and decreased activity of oxidative stress regulating enzymes.

Metabolomic profiling reveals serum L-pyroglutamic acid as a potential diagnostic biomarker for systemic lupus erythematosus

Objective

The spectrum of clinical manifestations and serological phenomena of SLE is heterogeneous among patients and even changes over time unpredictably in individual patients. For this reason, clinical diagnosis especially in complicated or atypical cases is often difficult or delayed leading to poor prognosis. Despite the medical progress nowadays in the understanding of SLE pathogenesis, disease-specific biomarkers for SLE remain an outstanding challenge. Therefore, we undertook this study to investigate potential biomarkers for SLE diagnosis.

Methods

Serum samples from 32 patients with SLE and 25 gender-matched healthy controls (HCs) were analysed by metabolic profiling based on liquid chromatography–tandem mass spectrometry metabolomics platform. The further validation for the potential biomarker was performed in an independent set consisting of 36 SLE patients and 30 HCs.

Results

The metabolite profiles of serum samples allowed differentiation of SLE patients from HCs. The levels of arachidonic acid, sphingomyelin (SM) 24:1, monoacylglycerol (MG) 17:0, lysophosphatidyl ethanolamine (lysoPE) 18:0, lysoPE 16:0, lysophosphatidyl choline (lysoPC) 20:0, lysoPC 18:0 and adenosine were significantly decreased in SLE patients, and the MG 20:2 and L-pyroglutamic acid were significantly increased in SLE group. In addition, L-pyroglutamic acid achieved an area under the receiver-operating characteristic curve of 0.955 with high sensitivity (97.22%) and specificity (83.33%) at the cut-off of 61.54 μM in the further targeted metabolism, indicating diagnostic potential.

Conclusion

Serum metabolic profiling is differential between SLE patients and HCs and depicts increased L-pyroglutamic acid as a promising bitformatomarker for SLE.

A Review of Dietary (Phyto)Nutrients for Glutathione Support

Glutathione is a tripeptide that plays a pivotal role in critical physiological processes resulting in effects relevant to diverse disease pathophysiology such as maintenance of redox balance, reduction of oxidative stress, enhancement of metabolic detoxification, and regulation of immune system function. The diverse roles of glutathione in physiology are relevant to a considerable body of evidence suggesting that glutathione status may be an important biomarker and treatment target in various chronic, age-related diseases. Yet, proper personalized balance in the individual is key as well as a better understanding of antioxidants and redox balance. Optimizing glutathione levels has been proposed as a strategy for health promotion and disease prevention, although clear, causal relationships between glutathione status and disease risk or treatment remain to be clarified. Nonetheless, human clinical research suggests that nutritional interventions, including amino acids, vitamins, minerals, phytochemicals, and foods can have important effects on circulating glutathione which may translate to clinical benefit. Importantly, genetic variation is a modifier of glutathione status and influences response to nutritional factors that impact glutathione levels. This narrative review explores clinical evidence for nutritional strategies that could be used to improve glutathione status.

Circulating antioxidant levels in systemic lupus erythematosus patients: a systematic review and meta-analysis

Aim: To derive a precise estimation on plasma/serum level of SOD, GPx, CAT and GSH levels in systemic lupus erythematosus (SLE) patients. Methods: A total of 36 articles from electronic databases were finally included with 1120 SLE patients and 1024 healthy controls considered for antioxidant levels. Results: The levels of CAT and GSH were significantly lower, while SOD and GPx levels were slightly lower in patients with SLE compared with healthy controls. Subgroup analysis indicated that Arabs, ages ≥40 and SLE diseases activity index <6 had a significant association of SOD and CAT levels with SLE patients. Conclusion: The results demonstrated a significant lower CAT and GSH levels and also revealed no significant difference for SOD and GPx levels in SLE patients.

Chromatin restriction by the nucleosome remodeler Mi-2β and functional interplay with lineage-specific transcription regulators control B-cell differentiation

Here, Yoshida et al. investigate the role of Mi-2β, a SNF-2-like nucleosome remodeler and key component of the nucleosome remodeling and histone deacetylase (NuRD) complex in early B cells. They found that the nucleosome remodeler Mi-2β promotes pre-B-cell differentiation by providing repression capabilities to distinct lineage-specific transcription factor-based regulatory networks.

Coordinated induction, but also repression, of genes are key to normal differentiation. Although the role of lineage-specific transcription regulators has been studied extensively, their functional integration with chromatin remodelers, one of the key enzymatic machineries that control chromatin accessibility, remains ill-defined. Here we investigate the role of Mi-2β, a SNF-2-like nucleosome remodeler and key component of the nucleosome remodeling and histone deacetylase (NuRD) complex in early B cells. Inactivation of Mi-2β arrested differentiation at the large pre-B-cell stage and caused derepression of cell adhesion and cell migration signaling factors by increasing chromatin access at poised enhancers and chromosome architectural elements. Mi-2β also supported IL-7R signaling, survival, and proliferation by repressing negative effectors of this pathway. Importantly, overexpression of Bcl2, a mitochondrial prosurvival gene and target of IL-7R signaling, partly rescued the differentiation block caused by Mi-2β loss. Mi-2β stably associated with chromatin sites that harbor binding motifs for IKAROS and EBF1 and physically associated with these transcription factors both on and off chromatin. Notably, Mi-2β shared loss-of-function cellular and molecular phenotypes with IKAROS and EBF1, albeit in a distinct fashion. Thus, the nucleosome remodeler Mi-2β promotes pre-B-cell differentiation by providing repression capabilities to distinct lineage-specific transcription factor-based regulatory networks.

Immune checkpoints and the regulation of tolerogenicity in dendritic cells: Implications for autoimmunity and immunotherapy

The immune system is responsible for defending the host from a large variety of potential pathogens, while simultaneously avoiding immune reactivity towards self-components. Self-tolerance has to be tightly maintained throughout several central and peripheral processes; immune checkpoints are imperative for regulating the immunity/tolerance balance. Dendritic cells (DCs) are specialized cells that capture antigens, and either activate or inhibit antigen-specific T cells. Therefore, they play a key role at inducing and maintaining immune tolerance. DCs that suppress the immune response have been called tolerogenic dendritic cells (tolDCs). Given their potential as a therapy to prevent transplant rejection and autoimmune damage, several strategies are under development to generate tolDCs, in order to avoid activation and expansion of self-reactive T cells. In this article, we summarize the current knowledge relative to the main features of tolDCs, their mechanisms of action and their therapeutic use for autoimmune diseases. Based on the literature reviewed, autologous antigen-specific tolDCs might constitute a promising strategy to suppress autoreactive T cells and reduce detrimental inflammatory processes.

The Impact of Protein Acetylation/Deacetylation on Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a chronic inflammatory autoimmune disease in which the body’s immune system mistakenly attacks healthy cells. Although the exact cause of SLE has not been identified, it is clear that both genetics and environmental factors trigger the disease. Identical twins have a 24% chance of getting lupus disease if the other one is affected. Internal factors such as female gender and sex hormones, the major histocompatibility complex (MHC) locus and other genetic polymorphisms have been shown to affect SLE, as well as external, environmental influences such as sunlight exposure, smoking, vitamin D deficiency, and certain infections. Several studies have reported and proposed multiple associations between the alteration of the epigenome and the pathogenesis of autoimmune disease. Epigenetic factors contributing to SLE include microRNAs, DNA methylation status, and the acetylation/deacetylation of histone proteins. Additionally, the acetylation of non-histone proteins can also influence cellular function. A better understanding of non-genomic factors that regulate SLE will provide insight into the mechanisms that initiate and facilitate disease and also contribute to the development of novel therapeutics that can specifically target pathogenic molecular pathways.

Lice induced immuno-oxidative wreckage of goats

The present study aimed to evaluate the immuno-oxidative patho-biology of lice infestation in goats. Sixty goats were divided into five groups; sucking lice (Linognathus africanus) infested (Group 1, n=12), chewing lice (Bovicola caprae) infested-mild (Group 2, n=12), chewing lice (B. caprae) infested-moderate (Group 3, n=12), chewing lice (B. caprae) infested-severe (Group 4, n=12) and healthy control (Group 5, n=12). To assess the pathological changes, markers of oxidative stress (lipid peroxidation-LPO, reduced glutathione-GSH, superoxide dismutase-SOD, Catalase-CAT and total antioxidant capacity-TAC), the markers of immune status (Tumour necrosis factor alpha- TNF-α, Interleukin-10- IL-10, Transforming growth factor beta 1- TGF-β1, ratios of TNF-α/IL-10 and TNF-α/TGF-β1) and hemato-biochemical status were evaluated. Significant anemia, hypoglycemia, hypoproteinemia and hypoalbuminemia were observed in caprine pediculosis irrespective of the type of lice infested. Remarkably increased oxidative stress was observed in chewing lice infested goats and no significant changes in oxidative stress markers were observed in sucking lice infested goats. TGF-β mediated suppression of Th1 and Th2 immune responses was observed in sucking lice infested goats; whereas, a Th2 cytokine dominant inflammatory response was observed in chewing lice infested goats. From the present study, it may be concluded that sucking lice infestation produces remarkable immunosuppression and chewing lice infestation produces significant oxidative stress and inflammatory responses in goats.

Protandim Protects Oligodendrocytes against an Oxidative Insult

Oligodendrocyte damage and loss are key features of multiple sclerosis (MS) pathology. Oligodendrocytes appear to be particularly vulnerable to reactive oxygen species (ROS) and cytokines, such as tumor necrosis factor-α (TNF), which induce cell death and prevent the differentiation of oligodendrocyte progenitor cells (OPCs). Here, we investigated the efficacy of sulforaphane (SFN), monomethyl fumarate (MMF) and Protandim to induce Nrf2-regulated antioxidant enzyme expression, and protect oligodendrocytes against ROS-induced cell death and ROS-and TNF-mediated inhibition of OPC differentiation. OLN-93 cells and primary rat oligodendrocytes were treated with SFN, MMF or Protandim resulting in significant induction of Nrf2-driven (antioxidant) proteins heme oygenase-1, nicotinamide adenine dinucleotide phosphate (NADPH): quinone oxidoreductase-1 and p62/SQSTM1, as analysed by Western blotting. After incubation with the compounds, oligodendrocytes were exposed to hydrogen peroxide. Protandim most potently promoted oligodendrocyte cell survival as measured by live/death viability assay. Moreover, OPCs were treated with Protandim or vehicle control prior to exposing them to TNF or hydrogen peroxide for five days, which inhibited OPC differentiation. Protandim significantly promoted OPC differentiation under influence of ROS, but not TNF. Protandim, a combination of five herbal ingredients, potently induces antioxidants in oligodendrocytes and is able to protect oligodendrocytes against oxidative stress by preventing ROS-induced cell death and promoting OPC differentiation.

Different end-points to assess effects in systemic lupus erythematosus patients exposed to pesticide mixtures

Systemic Lupus Erythematosus (SLE) is an autoimmune disease with high female predominance in reproductive years. It is characterized by a pronounced inflammation and production of a variety of autoantibodies. SLE pathogenesis is influenced by genes, hormones and environmental agents. The aim of this study was assess the possible effect of environmental pesticide mixtures in SLE patients. Oxidative DNA damage was measured using the comet assay modified by enzyme Endo III for detection of oxidized bases (Endo Sites), and oxidative stress by the measurement of the activity of catalase (CAT), superoxide dismutase (SOD) and lipid peroxidation (TBARS). Eighty-nine patients with diagnosis of SLE were included, 46% of them came from areas highly sprayed with pesticides and were compared with patients from urban areas with the same clinical and socio-demographic characteristics (p≥0.155). In order to identify factors that could predict DNA damage and oxidative stress, a binary logistic regression model with independent variables was developed: place of residence (p=0.007) have 75% of positive predictive value while smoking habit (p=0.186) have a 56% negative predictive value. The Odd Ratio (OR) obtained indicate that lupus patients living in rural areas presented 3.52 times more oxidative DNA damage compared to those living in the city. The prospects of applying biomarkers to assess exposure and biological effects, such as DNA damage and oxidative stress in autoimmune diseases, allow improving the characterization of individual risk.

Oxidative stress in the pathogenesis of atherothrombosis associated with anti-phospholipid syndrome and systemic lupus erythematosus: new therapeutic approaches

Atherothrombosis is a recurrent complication in APS and SLE patients. Oxidative stress has been suggested as a key player underlying this process. Autoantibodies have been pointed to as the main contributors to abnormality in the oxidative status observed in APS and SLE patients, promoting the increased production of oxidant species and the reduction of antioxidant molecules. This imbalance causes vascular damage through the activation of immune cells, including monocytes, lymphocytes and neutrophils, causing the expression of pro-inflammatory and procoagulant molecules, the formation of neutrophil extracellular traps and the adhesion of these cells to the endothelium; the induction of cellular apoptosis and impaired cell clearance, which in turn enhances autoantibody neogeneration; and cytotoxicity of endothelial cells. This review describes the mechanisms underlying the role of oxidative stress in the pathogenesis of atherothrombosis associated with APS and SLE, focused on the effect of autoantibodies, the different cell types involved and the diverse effectors, including cytokines, procoagulant proteins and their main modulators, such as oxidant/antioxidant species and intracellular pathways in each pathology. We further discuss new therapies aimed at restoring the oxidative stress balance and subsequently to tackle atherothrombosis in APS and SLE.

Nonenzymatic antioxidants in saliva of patients with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by autoantibody-directed self-antigens, immune complex formation and immune deregulation, resulting in damage to essentially all the organs. SLE is associated with the increased production of free radicals. Increase in free radicals or impaired antioxidant defense system in SLE causes oxidative stress. Considering that saliva could be a reflection of the state of health, the purpose of this study was to evaluate some antioxidants in the saliva and serum of patients with SLE and compare these with healthy individuals. This could help us in obtaining a possible marker in saliva in the future. During the course of the practical part of the project, 30 patients with SLE and 30 healthy controls were investigated. After centrifugation of un-stimulated saliva and blood samples, they were examined using spectrophotometric methods and the results were analyzed by statistical software. According to the results, concentrations of malondialdehyde, uric acid and total antioxidants were significantly increased but the level of reduced glutathion was reduced significantly in the saliva and serum of SLE patients as compared to controls. It is therefore suggested that antioxidant power is impaired in saliva and serum of SLE patients. As there was a positive correlation between the antioxidant level of saliva and blood serum, the antioxidant status of saliva could be an indicator of serum antioxidants.

Autoimmunity in 2013

The peer-reviewed publications in the field of autoimmunity published in 2013 represented a significant proportion of immunology articles and grew since the previous year to indicate that more immune-mediated phenomena may recognize an autoimmune mechanism and illustrated by osteoarthritis and atherosclerosis. As a result, our understanding of the mechanisms of autoimmunity is becoming the paradigm for translational research in which the progress in disease pathogenesis for both tolerance breakdown and inflammation perpetuation is rapidly followed by new treatment approaches and clinical management changes. The similarities across the autoimmune disease spectrum outnumber differences, particularly when treatments are compared. Indeed, the therapeutics of autoimmune diseases are based on a growing armamentarium that currently includes monoclonal antibodies and small molecules which act by targeting molecular markers or intracellular mediators with high specificity. Among the over 100 conditions considered as autoimmune, the common grounds are well illustrated by the data reported for systemic lupus erythematosus and rheumatoid arthritis or by the plethora of studies on Th17 cells and biomarkers, particularly serum autoantibodies. Further, we are particularly intrigued by studies on the genomics, epigenetics, and microRNA at different stages of disease development or on the safe and effective use of abatacept acting on the costimulation of T and B cells in rheumatoid arthritis. We are convinced that the data published in 2013 represent a promising background for future developments that will exponentially impact the work of laboratory and clinical scientists over the next years.

Serum thiols as a biomarker of disease activity in lupus nephritis

Lupus Nephritis (LN) develops in more than half of the Systemic Lupus Erythematous (SLE) patients. However, lack of reliable, specific biomarkers for LN hampers clinical management of patients and impedes development of new therapeutics. The goal of this study was to investigate whether oxidative stress biomarkers in patients with SLE is predictive of renal pathology. Serum biochemical and oxidative stress markers were measured in patients with inactive lupus, active lupus with and without nephritis and compared to healthy control group. To assess the predictive performance of biomarkers, Receiver Operating Characteristic (ROC) curves were constructed and cut-offs were used to identify SLE patients with nephritis. We observed an increased oxidative stress response in all SLE patients compared to healthy controls. Among the several biomarkers tested, serum thiols had a significant inverse association with SLE Disease Activity Index (SLEDAI). Interestingly, thiols were able too aptly differentiate between SLE patients with and without renal pathology, and serum thiol levels were not affected by immunosuppressive drug therapy. The decreased thiols in SLE correlated significantly with serum creatinine and serum C3 levels. Further retrospective evaluation using serum creatinine or C3 levels in combination with thiol's cutoff values from ROC analysis, we could positively predict chronicity of renal pathology in SLE patients. In summary, serum thiols emerge as an inexpensive and reliable indicator of LN, which may not only help in early identification of renal pathology but also aid in the therapeutic management of the disease, in developing countries with resource poor settings.

Environmental exposures, epigenetic changes and the risk of lupus

A dose-dependent combination of environmental exposures, estrogenic hormones and genetic predisposition is thought to be required for lupus to develop and flare, but how the environment modifies the immune system in genetically predisposed people is unclear. Current evidence indicates that environmental agents that inhibit DNA methylation can convert normal antigen-specific CD4+ T lymphocytes into autoreactive, cytotoxic, pro-inflammatory cells that are sufficient to cause lupus-like autoimmunity in animal models, and that the same changes in DNA methylation characterize CD4+ T cells from patients with active lupus. Environmental agents implicated in inhibiting T-cell DNA methylation include the lupus-inducing drugs procainamide and hydralazine, as well as diet, and agents causing oxidative stress, such as smoking, UV light exposure, and infections, which have been associated with lupus onset or disease activity. Other studies demonstrate that demethylated T cells cause only anti-DNA antibodies in mice lacking a genetic predisposition to lupus, but are sufficient to cause lupus-like autoimmunity in genetically predisposed mice and likely people, and that estrogens augment the disease. Collectively, these studies suggest that environmental agents that inhibit DNA methylation, together with lupus genes and estrogens or endocrine disruptors, combine in a dose-dependent fashion to cause lupus flares.

Gene expression during the generation and activation of mouse neutrophils: implication of novel functional and regulatory pathways

As part of the Immunological Genome Project (ImmGen), gene expression was determined in unstimulated (circulating) mouse neutrophils and three populations of neutrophils activated in vivo, with comparison among these populations and to other leukocytes. Activation conditions included serum-transfer arthritis (mediated by immune complexes), thioglycollate-induced peritonitis, and uric acid-induced peritonitis. Neutrophils expressed fewer genes than any other leukocyte population studied in ImmGen, and down-regulation of genes related to translation was particularly striking. However, genes with expression relatively specific to neutrophils were also identified, particularly three genes of unknown function: Stfa2l1, Mrgpr2a and Mrgpr2b. Comparison of genes up-regulated in activated neutrophils led to several novel findings: increased expression of genes related to synthesis and use of glutathione and of genes related to uptake and metabolism of modified lipoproteins, particularly in neutrophils elicited by thioglycollate; increased expression of genes for transcription factors in the Nr4a family, only in neutrophils elicited by serum-transfer arthritis; and increased expression of genes important in synthesis of prostaglandins and response to leukotrienes, particularly in neutrophils elicited by uric acid. Up-regulation of genes related to apoptosis, response to microbial products, NFkB family members and their regulators, and MHC class II expression was also seen, in agreement with previous studies. A regulatory model developed from the ImmGen data was used to infer regulatory genes involved in the changes in gene expression during neutrophil activation. Among 64, mostly novel, regulatory genes predicted to influence these changes in gene expression, Irf5 was shown to be important for optimal secretion of IL-10, IP-10, MIP-1α, MIP-1β, and TNF-α by mouse neutrophils in vitro after stimulation through TLR9. This data-set and its analysis using the ImmGen regulatory model provide a basis for additional hypothesis-based research on the importance of changes in gene expression in neutrophils in different conditions.

Altered glutamate cysteine ligase activity in peripheral blood mononuclear cells from patients with systemic lupus erythematosus

Reductions in glutathione (GSH) levels have been shown to be associated with aging and the pathogenesis of a variety of diseases, including systemic lupus erythematosus (SLE). Glutamate cysteine ligase (GCL) catalyzes the first and rate-limiting step of GSH synthesis. In order to appraise the correlation between oxidative stress and the severity and activity of SLE, GSH, oxidized GSH (GSSG) and thioredoxin (TRX) concentrations and the enzymatic activity levels of GCL in peripheral blood mononuclear cells (PBMCs) from patients with SLE and healthy controls were studied. In patients with SLE, the levels of GCL activity and GSH decreased, while TRX and GSSG levels increased when compared with those in the healthy controls. GSH concentrations and GCL activity levels negatively correlated with the SLE disease activity index and erythrocyte sedimentation rate. Furthermore, patients with SLE and nephritis had lower levels of GSH and GCL activity and higher levels of TRX and GSSG compared with those in SLE patients without nephritis. Therefore, the results of the present study indicate that insufficient levels of GSH and GCL activity in PBMCs may contribute to the pathogenesis of SLE.

Common variable immunodeficiency and autoimmunity--an inconvenient truth

Coexisting morbidities in CVID include bronchiectasis, autoimmunity and malignancies. The incidence of autoimmune disease in CVID patients may approach 20% of cases. The most common autoimmune disease found in CVID patients is autoimmune cytopenia, but rheumatoid arthritis, lupus, and now primary biliary cirrhosis have also been reported. The coexistence of immunodeficiency and autoimmunity appears paradoxical, since one represents a hypoimmune state and the other a hyperimmune state. However, this paradox may not actually be all that implausible due to the complex nature of immune cells, signaling pathways and their interactions. The cellular alterations in combined variable immunodeficiency include a range of T and B cell abnormalities. Selective immune derangements found in CVID include a downregulation of regulatory T cells (Treg cells), accelerated T cell apoptosis, abnormal cytokine production secondary to cytokine gene polymorphisms and increased autoreactive B cell production. The impact of these abnormalities on T and B cell interaction may not only explain the immunodeficiency but also the development of autoimmunity in select groups of patients with CVID. The variability in the clinical manifestations of CVID as a result of this immune interaction suggests that CVID is not one disease but many. This is important because it follows that the treatment of CVID may not always be the same, but may need to be directed specifically towards each individual patient.

Oxidative stress and its biomarkers in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune inflammatory disease whose etiology remains largely unknown. The uncontrolled oxidative stress in SLE contributes to functional oxidative modifications of cellular protein, lipid and DNA and consequences of oxidative modification play a crucial role in immunomodulation and trigger autoimmunity. Measurements of oxidative modified protein, lipid and DNA in biological samples from SLE patients may assist in the elucidation of the pathophysiological mechanisms of the oxidative stress-related damage, the prediction of disease prognosis and the selection of adequate treatment in the early stage of disease. Application of these biomarkers in disease may indicate the early effectiveness of the therapy. This review is intended to provide an overview of various reactive oxygen species (ROS) formed during the state of disease and their biomarkers linking with disease. The first part of the review presents biochemistry and pathophysiology of ROS and antioxidant system in disease. The second part of the review discusses the recent development of oxidative stress biomarkers that relates pathogenesis in SLE patients and animal model. Finally, this review also describes the reported clinical trials of antioxidant in the disease that have evaluated the efficacy of antioxidant in the management of disease with ongoing conventional therapy.

Autoimmunity: from black water fever to regulatory function

Autoimmunity is a field that has only been around for a little over a century. Initially, it was thought that autoimmunity could not happen, that the body would never turn on itself (i.e. "horror autotoxicus"). It was only around the First World War that autoimmunity was recognized as the pathogenesis of various diseases, including rheumatoid arthritis. The discovery of Compound E led to successful treatment of patients with autoimmune diseases, but it was not till later that the adverse effects of this class of drugs were elucidated. The "modern" age of autoimmunity began around 1945 with the description of blackwater fever, and most of the subsequent research on hemolytic anemia and the role of an autoantibody in its pathogenesis led to a description of the anti-globulin reaction. The lupus erythematous (LE) cell was recognized in the mid-1940s by Hargreaves. His research carried on into the 1960s. Rheumatoid factor was also first described in the 1940s as yet another serum factor with activity against globulin-coated sheep red blood cells. The concept of autoimmunity really gained a foothold in the 1950s, when autoimmune thyroid disease and idiopathic thrombocytopenia were first described. Much has happened since then, and our understanding of autoimmunity has evolved now to include mechanisms of apoptosis, signaling pathway derangements, and the discovery of subsets of T cells with regulatory activity. The modern day study of autoimmunity is a fascinating area of research, and full understanding of the pathogenesis of autoimmune diseases is far from being completely elucidated.

Noxa in rheumatic diseases: present understanding and future impact

Impaired programmed cell death is an important contributing mechanism in the development of chronic inflammatory and autoimmune diseases. Overexpression of Bcl-2 family proteins in such diseases has led to the concept of targeted suppression of these proteins as a primary therapeutic strategy. However, limited success with this approach has prompted pharmacologists to look at the other side of the coin, with the aim of reactivating jeopardized pro-apoptotic proteins that may neutralize Bcl-2 or other anti-apoptotic molecules. In this effort, BH3-only proteins have gained recent attention as endogenous molecules for the sensitization of resistant cells to undergo apoptosis. Among the BH3-only family, Noxa stands out as exceptional for its specificity to bind Mcl-1 and Bcl-2 and blunt their biological properties. Noxa is now being tested as a promising therapeutic target in cancer biology. Nonetheless, its role and clinical application still lack validation in autoimmune diseases, including rheumatic conditions. This is partly attributed to the significant gap in our understanding of its regulatory role and how either overexpression of Noxa or delivery of BH3 mimetics could be therapeutically exploited. In this review we highlight some recent studies in RA, OA, SLE and SS suggesting that Noxa may be used as a potential therapeutic target to circumvent invasive and tissue destructive processes in these rheumatic diseases.