Oxidative stress and dietary micronutrient deficiencies contribute to overexpression of epigenetically regulated genes by lupus T cells

Ultraprocessed Food Intake and Risk of Systemic Lupus Erythematosus Among Women Observed in the Nurses' Health Study Cohorts

OBJECTIVE

We assessed ultraprocessed food (UPF) intake and systemic lupus erythematosus (SLE) incidence within the prospective Nurses' Health Study (NHS) cohorts.

METHODS

A total of 204,175 women were observed (NHS 1984-2016; NHSII 1991-2017). Semiquantitative food frequency questionnaires were completed every two to four years. UPF intake was determined as per the Nova classification. Nurses self-reported new doctor-diagnosed SLE, confirmed by medical records. Time-varying Cox regressions estimated hazard ratios (HRs; 95% confidence intervals [CIs]) for patients with incident SLE and SLE by anti-double-stranded DNA (dsDNA) antibody at diagnosis, according to cumulatively updated daily (a) UPF servings, (b) total intake (in grams and milliliters), and (c) percentage of total intake. Analyses adjusted for age, race, cohort, caloric and alcohol intakes, household income, smoking, body mass index (BMI), physical activity, menarchal age, and oral contraceptive use. We tested for interaction with BMI and examined UPF categories.

RESULTS

Mean baseline age was ~50 years (NHS) and ~36 years (NHSII); 93% self-reported White race. A total of 212 patients with incident SLE were identified. SLE risk was higher in the third versus first UPF tertile (servings per day pooled multivariable [MV] HR 1.56, 95% CI 1.04-2.32; P = 0.03). Results were stronger for dsDNA antibody in patients with SLE (servings per day pooled MV HR 2.05, 95% CI 1.15-3.65; P = 0.01) and for absolute (servings or total) than percentage of total intake. Sugar-sweetened/artificially sweetened beverages were associated with SLE risk (third vs first tertile MV HR 1.45, 95% CI 1.01-2.09). No BMI interactions were observed.

CONCLUSION

Higher cumulative average daily UPF intake was associated with >50% increased SLE risk and with doubled risk for anti-dsDNA antibody in patients with SLE. Many deleterious effects on systemic inflammation and immunity are postulated.

Bioguided Optimization of the Nutrition-Health, Antioxidant, and Immunomodulatory Properties of Manihot esculenta (Cassava) Flour Enriched with Cassava Leaves

Manihot esculenta (cassava) roots is a major food crop for its energy content. Leaves contain nutrients and demonstrate biological properties but remain undervalorized. In order to develop a bioguided optimization of cassava nutrition-health properties, we compared the phytochemistry and bioactive potential of cassava root flour extract (CF) with cassava flour extract enriched with 30% leaves powder (CFL). Cassava flour supplementation impact was explored on flour composition (starch, fiber, carotenoids, phenolic compounds), in vivo glycemic index, and bioactivity potential using macrophage cells. We assessed the impact of cassava flour supplementation on free radicals scavenging and cellular production of pro-inflammatory mediators. CFL showed higher levels of fiber, carotenoids, phenolic compounds, and lower glycemic index. Significantly higher bioactive properties (anti-inflammatory and antioxidant) were recorded, and inhibition of cytokines production has been demonstrated as a function of extract concentration. Overall, our results indicate that enrichment of cassava flour with leaves significantly enhances its nutrition-health and bioactive potential. This bioguided matrix recombination approach may be of interest to provide prophylactic and therapeutic dietary strategy to manage malnutrition and associated chronic non-communicable diseases characterized by low-grade inflammation and unbalanced redox status. It would also promote a more efficient use of available food resources.

Differential impact of environmental factors on systemic and localized autoimmunity

The influence of environmental factors on the development of autoimmune disease is being broadly investigated to better understand the multifactorial nature of autoimmune pathogenesis and to identify potential areas of intervention. Areas of particular interest include the influence of lifestyle, nutrition, and vitamin deficiencies on autoimmunity and chronic inflammation. In this review, we discuss how particular lifestyles and dietary patterns may contribute to or modulate autoimmunity. We explored this concept through a spectrum of several autoimmune diseases including Multiple Sclerosis (MS), Systemic Lupus Erythematosus (SLE) and Alopecia Areata (AA) affecting the central nervous system, whole body, and the hair follicles, respectively. A clear commonality between the autoimmune conditions of interest here is low Vitamin D, a well-researched hormone in the context of autoimmunity with pleiotropic immunomodulatory and anti-inflammatory effects. While low levels are often correlated with disease activity and progression in MS and AA, the relationship is less clear in SLE. Despite strong associations with autoimmunity, we lack conclusive evidence which elucidates its role in contributing to pathogenesis or simply as a result of chronic inflammation. In a similar vein, other vitamins impacting the development and course of these diseases are explored in this review, and overall diet and lifestyle. Recent work exploring the effects of dietary interventions on MS showed that a balanced diet was linked to improvement in clinical parameters, comorbid conditions, and overall quality of life for patients. In patients with MS, SLE and AA, certain diets and supplements are linked to lower incidence and improved symptoms. Conversely, obesity during adolescence was linked with higher incidence of MS while in SLE it was associated with organ damage. Autoimmunity is thought to emerge from the complex interplay between environmental factors and genetic background. Although the scope of this review focuses on environmental factors, it is imperative to elaborate the interaction between genetic susceptibility and environment due to the multifactorial origin of these disease. Here, we offer a comprehensive review about the influence of recent environmental and lifestyle factors on these autoimmune diseases and potential translation into therapeutic interventions.

Essential Trace Element Status in Systemic Lupus Erythematosus: a Meta-analysis Based on Case-Control Studies

The homeostasis of trace elements is essential to regulate different aspects of the immune system and might play important roles in systemic lupus erythematosus (SLE). However, epidemiological evidences that compared the level of essential trace elements in SLE patients and healthy controls (HCs) did not reach a consensus. This was the first meta-analysis to comprehensively assess the level of zinc (Zn), copper (Cu), iron (Fe), and selenium (Se) in SLE and HCs. PubMed, Embase, and Web of Science were systematically searched until April 2022 to find relevant literatures. The PRISMA statement 2020 was followed to make sure the quality of reporting a meta-analysis. The outcomes were assessed by pooled standardized mean difference (SMD) and 95% confidence intervals (CIs). Finally, eleven articles with 1262 subjects were included in the meta-analysis. Significantly lower levels of Zn (SMD = -0.709; 95% CI: -1.173, -0.245; P = 0.003) and Fe (SMD = -1.783; 95% CI: -2.756, -0.809; P = 0.000) were found in SLE compared with HCs. Higher levels of Cu (SMD = 0.808; 95% CI: 0.234, 1.382; P = 0.006) were found in SLE patients. In addition, compared with HCs, Fe and Zn were lower in SLE patients in Asia and Cu was higher in SLE patients in Europe. However, no significant difference was observed in the level of Se (SMD = -0.251; 95% CI: -1.087, 0.586; P = 0.557). Above all, SLE patients exhibited lower Zn and Fe and increased Cu concentrations compared with HCs. Further studies are warranted to investigate the mechanism of Zn, Cu, and Fe in SLE patients.

Oxidative Stress Contributes to Inflammatory and Cellular Damage in Systemic Lupus Erythematosus: Cellular Markers and Molecular Mechanism

Systemic lupus erythematosus (SLE) is a multifactorial autoimmune disease with complex pathogenesis, the treatment of which relies exclusively on the use of immunosuppressants. Increased oxidative stress is involved in causing inflammatory and cellular defects in the pathogenesis of SLE. Various inflammatory and cellular markers including oxidative modifications of proteins, lipids, and DNA contribute to immune system dysregulation and trigger an aggressive autoimmune attack through molecular mechanisms like enhanced NETosis, mTOR pathway activation, and imbalanced T-cell differentiation. Accordingly, the detection of inflammatory and cellular markers is important for providing an accurate assessment of the extent of oxidative stress. Oxidative stress also reduces DNA methylation, thus allowing the increased expression of affected genes. As a result, pharmacological approaches targeting oxidative stress yield promising results in treating patients with SLE. The purpose of this review is to examine the involvement of oxidative stress in the pathogenesis and management of SLE.

Targeting epigenetic regulators for inflammation: Mechanisms and intervention therapy

Emerging evidence indicates that resolution of inflammation is a critical and dynamic endogenous process for host tissues defending against external invasive pathogens or internal tissue injury. It has long been known that autoimmune diseases and chronic inflammatory disorders are characterized by dysregulated immune responses, leading to excessive and uncontrol tissue inflammation. The dysregulation of epigenetic alterations including DNA methylation, posttranslational modifications to histone proteins, and noncoding RNA expression has been implicated in a host of inflammatory disorders and the immune system. The inflammatory response is considered as a critical trigger of epigenetic alterations that in turn intercede inflammatory actions. Thus, understanding the molecular mechanism that dictates the outcome of targeting epigenetic regulators for inflammatory disease is required for inflammation resolution. In this article, we elucidate the critical role of the nuclear factor-κB signaling pathway, JAK/STAT signaling pathway, and the NLRP3 inflammasome in chronic inflammatory diseases. And we formulate the relationship between inflammation, coronavirus disease 2019, and human cancers. Additionally, we review the mechanism of epigenetic modifications involved in inflammation and innate immune cells. All that matters is that we propose and discuss the rejuvenation potential of interventions that target epigenetic regulators and regulatory mechanisms for chronic inflammation-associated diseases to improve therapeutic outcomes.

Regulation of the cellular redox state and the expression of DNA methyltransferase-1 in peripheral blood mononuclear cells from patients with Graves' disease

BACKGROUND

Graves' disease is an autoimmune disorder characterised by excessive production of thyroid hormones, which induces increased cellular metabolism in most tissues and increased production of reactive oxygen species (ROS). The aim of this work was to analyse the effect of ROS on cell viability and the expression of catalase (CAT), glutathione peroxidase-1 (GPx-1), superoxide dismutase (SOD-1) and DNA methyltransferase-1 (DNMT-1) in peripheral blood mononuclear cells (PBMC) from patients with newly diagnosed Graves' disease or treated with methimazole.

PATIENTS AND METHODS

For this study, women patients with newly diagnosed Graves' disease (n=18), treated with methimazole (n=6) and healthy subjects (n=15) were recruited. ROS were evaluated by flow cytometry, and the viability/apoptosis of PBMC was analysed by flow cytometry and fluorescence microscopy. Genomic expression of CAT, GPx-1, SOD-1 and DNMT-1 was quantified by real-time PCR.

RESULTS

We found high levels of ROS and increased expression of CAT, GPx-1, SOD-1 and DNMT-1 in PBMC from patients with newly diagnosed Graves' disease. Methimazole treatment reversed these parameters. Cell viability was similar in all study groups.

CONCLUSIONS

ROS induces the expression of CAT, GPx-1, and SOD-1. The activity of these enzymes may contribute to the protection of PBMC from the harmful effect of free radicals on cell viability. Increased expression of DNMT-1 may be associated with aberrant methylation patterns in immunoregulatory genes contributing to autoimmunity in Graves' disease.

T cell metabolism and possible therapeutic targets in systemic lupus erythematosus: a narrative review

In the immunopathogenesis of systemic lupus erythematosus (SLE), there is a dysregulation of specific immune cells, including T cells. The metabolic reprogramming in T cells causes different effects. Metabolic programs are critical checkpoints in immune responses and are involved in the etiology of autoimmune disease. For instance, resting lymphocytes generate energy through oxidative phosphorylation (OXPHOS) and fatty acid oxidation (FAO), whereas activated lymphocytes rapidly shift to the glycolytic pathway. Specifically, mitochondrial dysfunction, oxidative stress, abnormal metabolism (including glucose, lipid, and amino acid metabolism), and mTOR signaling are hallmarks of T lymphocyte metabolic dysfunction in SLE. Herein it is summarized how metabolic defects contribute to T cell responses in SLE, and some epigenetic alterations involved in the disease. Finally, it is shown how metabolic defects could be modified therapeutically.

The Role of Oxidative Stress in Epigenetic Changes Underlying Autoimmunity

Significance: Epigenetic dysregulation plays an important role in the pathogenesis and development of autoimmune diseases. Oxidative stress is associated with autoimmunity and is also known to alter epigenetic mechanisms. Understanding the interplay between oxidative stress and epigenetics will provide insights into the role of environmental triggers in the development of autoimmunity in genetically susceptible individuals. Recent Advances: Abnormal DNA and histone methylation patterns in genes and pathways involved in interferon and tumor necrosis factor signaling, cellular survival, proliferation, metabolism, organ development, and autoantibody production have been described in autoimmunity. Inhibitors of DNA and histone methyltransferases showed potential therapeutic effects in animal models of autoimmune diseases. Oxidative stress can regulate epigenetic mechanisms via effects on DNA damage repair mechanisms, cellular metabolism and the local redox environment, and redox-sensitive transcription factors and pathways. Critical Issues: Studies looking into oxidative stress and epigenetics in autoimmunity are relatively limited. The number of available longitudinal studies to explore the role of DNA methylation in the development of autoimmune diseases is small. Future Directions: Exploring the relationship between oxidative stress and epigenetics in autoimmunity will provide clues for potential preventative measures and treatment strategies. Inception cohorts with longitudinal follow-up would help to evaluate epigenetic marks as potential biomarkers for disease development, progression, and treatment response in autoimmunity. Antioxid. Redox Signal. 36, 423-440.

Cardiovascular Health in Pediatric Rheumatologic Diseases

Cardiovascular disease risk is evident during childhood for patients with juvenile systemic lupus erythematosus, juvenile dermatomyositis, and juvenile idiopathic arthritis. The American Heart Association defines cardiovascular health as a positive health construct reflecting the sum of protective factors against cardiovascular disease. Disease-related factors such as chronic inflammation and endothelial dysfunction increase cardiovascular disease risk directly and through bidirectional relationships with poor cardiovascular health factors. Pharmacologic and nonpharmacologic interventions to improve cardiovascular health and long-term cardiovascular outcomes in children with rheumatic disease are needed.

Association of Dietary Quality With Risk of Incident Systemic Lupus Erythematosus in the Nurses' Health Study and Nurses' Health Study II

OBJECTIVE

Knowledge remains scarce regarding diet and systemic lupus erythematosus (SLE) risk. Our objective was to investigate 4 dietary quality scores and SLE risk overall and by anti-double-stranded DNA (anti-dsDNA) positive versus negative subtypes.

METHODS

We studied 79,568 women in the Nurses' Health Study (1984-2014) and 93,554 in the Nurses' Health Study II (1991-2013). Using validated food frequency questionnaires, we calculated 4 dietary scores: the 2010 Alternative Healthy Eating Index (AHEI-2010), the Alternative Mediterranean Diet Score (aMed), the Dietary Approach to Stop Hypertension (DASH), and the Empirical Dietary Inflammatory Pattern (EDIP). Incident SLE was confirmed by medical record review. Time-varying Cox regression models estimated pooled hazard ratios (HRs) and 95% confidence intervals (95% CIs) of SLE risk, overall and by anti-dsDNA, for cumulative average dietary quality score tertiles and individual AHEI-2010 components.

RESULTS

We identified 194 incident SLE cases. SLE risk was similar in women with the highest (versus lowest) dietary scores (AHEI-2010 HR 0.78 [95% CI 0.54-1.14], aMed HR 0.82 [95% CI 0.56-1.18], DASH HR 1.16 [95% CI 0.81-1.66], EDIP HR 0.83 [95% CI 0.57-1.21]). No association was demonstrated for anti-dsDNA+ or anti-dsDNA- SLE risk. Women in the highest (versus lowest) AHEI-2010 tertile of nut/legume intake had a decreased SLE risk (HR 0.59 [95% CI 0.40-0.87]). No association was demonstrated for other AHEI-2010 components and SLE risk.

CONCLUSION

We observed no association between long-term adherence to the AHEI-2010, aMed, DASH, or EDIP scores with SLE risk, suggesting a large effect of dietary quality on SLE risk is unlikely. However, potential reduction in overall SLE risk with high nut/legume intake warrants further investigation.

Epigenetic linkage of systemic lupus erythematosus and nutrition

The term "epigenetics" refers to a series of meiotically/mitotically inheritable alterations in gene expression, related to environmental factors, without disruption on DNA sequences of bases. Recently, the pathophysiology of autoimmune diseases (ADs) has been closely linked to epigenetic modifications. Actually, epigenetic mechanisms can modulate gene expression or repression of targeted cells and tissues involved in autoimmune/inflammatory conditions acting as keys effectors in regulation of adaptive and innate responses. ADs, as systemic lupus erythematosus (SLE), a rare disease that still lacks effective treatment, is characterized by epigenetic marks in affected cells.Taking into account that epigenetic mechanisms have been proposed as a winning strategy in the search of new more specific and personalized therapeutics agents. Thus, pharmacology and pharmacoepigenetic studies about epigenetic regulations of ADs may provide novel individualized therapies. Focussing in possible implicated factors on development and predisposition of SLE, diet is feasibly one of the most important factors since it is linked directly to epigenetic alterations and these epigenetic changes may augment or diminish the risk of SLE. Nevertheless, several studies have guaranteed that dietary therapy could be a promise to SLE patients via prophylactic actions deprived of side effects of pharmacology, decreasing co-morbidities and improving lifestyle of SLE sufferers.Herein, we review and discuss the cross-link between epigenetic mechanisms on SLE predisposition and development, as well as the influence of dietary factors on regulation epigenetic modifications that would eventually make a positive impact on SLE patients.

UHRF1 downregulation promotes T follicular helper cell differentiation by increasing BCL6 expression in SLE

Background

Transcription factor B cell lymphoma 6 (BCL6) is a master regulator of T follicular helper (Tfh) cells, which play a crucial role in the pathogenesis of systemic lupus erythematosus (SLE). However, the mechanisms by which BCL6 expression is regulated are poorly understood. Ubiquitin-like with PHD and RING finger domains 1 (UHRF1) is an important epigenetic factor that regulates DNA methylation and histone modifications. In the present study, we assessed whether UHRF1 can regulate BCL6 expression and influence the differentiation and proliferation of Tfh cells.

Results

Compared to healthy controls, the mean fluorescence intensity of UHRF1 (UHRF1-MFI) in Tfh cells from SLE patients was significantly downregulated, whereas that of BCL6 (BCL6-MFI) was significantly upregulated. In vitro, UHRF1 knockdown led to BCL6 overexpression and promoted Tfh cell differentiation. In contrast, UHRF1 overexpression led to BCL6 downregulation and decreased Tfh cell differentiation. In vivo, conditional UHRF1 gene knockout (UHRF1-cKO) in mouse T cells revealed that UHRF1 depletion can enhance the proportion of Tfh cells and induce an augmented GC reaction in mice treated with NP-keyhole limpet hemocyanin (NP-KLH). Mechanistically, UHRF1 downregulation can decrease DNA methylation and H3K27 trimethylation (H3K27me3) levels in the BCL6 promoter region of Tfh cells.

Conclusions

Our results demonstrated that UHRF1 downregulation leads to increased BCL6 expression by decreasing DNA methylation and H3K27me3 levels, promoting Tfh cell differentiation in vitro and in vivo. This finding reveals the role of UHRF1 in regulating Tfh cell differentiation and provides a potential target for SLE therapy.

T cell Metabolism in Lupus

Abnormal T cell responses are central to the development of autoimmunity and organ damage in systemic lupus erythematosus. Following stimulation, naïve T cells undergo rapid proliferation, differentiation and cytokine production. Since the initial report, approximately two decades ago, that engagement of CD28 enhances glycolysis but PD-1 and CTLA-4 decrease it, significant information has been generated which has linked metabolic reprogramming with the fate of differentiating T cell in health and autoimmunity. Herein we summarize how defects in mitochondrial dysfunction, oxidative stress, glycolysis, glutaminolysis and lipid metabolism contribute to pro-inflammatory T cell responses in systemic lupus erythematosus and discuss how metabolic defects can be exploited therapeutically.