Serum Interleukin-23 in Polish Patients with Systemic Lupus Erythematosus: Association with Lupus Nephritis, Obesity, and Peripheral Vascular Disease

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.

Significance of Interleukin 23 in Systemic Lupus Patients: Relation to Disease Activity and Damage Indices

Background

Dysregulation of both cellular and humoral immune responses is central in systemic lupus erythematosus (SLE) pathogenetic mechanisms. Proinflammatory cytokines, such as interleukin 23 (IL23), and their roles in promoting such dysregulation have recently been highly considered. This research compared IL23 serum levels in 85 Egyptian SLE patients and 85 healthy controls. Then, IL23 level was correlated to various SLE disease parameters, disease activity, and damage indices.

Results

IL23 serum levels were significantly elevated in SLE patients versus healthy individuals. Furthermore, IL23 levels were positively correlated with SLE disease activity index (SLEDAI) and were positively correlated with arthritis, seizures, consumption of complements (C3, C4), and with parameters of nephritis (hematuria, pyuria, casts, and proteinuria). A positive correlation was also found between IL23 levels and oral prednisolone dose.

Conclusion

IL23 has higher levels in the serum of SLE patients, and is correlated to activity of the disease, especially lupus nephritis. Further researchis needed to explore its exact role in SLE pathogenesis and whether it can be considered a potential biomarker or therapeutic target in SLE.

LncRNA MEG3 regulates the interplay between Th17 and Treg cells in Behçet's disease and systemic lupus erythematosus

BACKGROUND

Behçet's disease (BD) and systemic lupus erythematosus (SLE) are two autoimmune inflammatory diseases of indefinite etiology. However, up till now, no study has explored the exact regulatory mechanisms of lncRNA maternally expressed gene-3 (MEG3) over the balance between regulatory T-cells (Treg) and T helper-17 (Th17) cells in BD and SLE.

AIM

The current study aimed to investigate the role of lncRNA MEG3 in the interplay between the anti-inflammatory Treg/transcription factor forkhead box P3 (FOXP3) axis versus the pro-inflammatory Th17/retinoic acid orphan receptor-γt (RORγt) axis.

MAIN METHODS

100 subjects, 35 with BD and 35 with SLE in addition to 30 healthy participants were included in the study. Gene expression analysis was performed and ShinyGO database was utilized for in-depth analysis and graphical visualization of the gene ontology (GO) and pathway enrichment analysis for lncRNA and the other target genes.

KEY FINDINGS

The current results demonstrate the upregulation of lncRNA MEG3 in BD but not SLE patients. Moreover, significant differences in RORγt and FOXP3 were found between BD and SLE patients. The present findings linked lncRNA MEG3 to BD activity scores as well as CRP levels. Finally, lncRNA MEG3 showed excellent diagnostic power for BD, in addition to adequate discriminative power that can be used to differentiate between BD and SLE.

SIGNIFICANCE

The current study objectively elucidated a framework for the involvement of Treg/Th17 through transcription factors RORγt and FOXP3, in addition to their links to the downstream cytokines network including TGF-ꞵ, IL-10, IL-17 and IL-23 in BD and SLE pathogenesis and activity.

Anti-Phosphatidylethanolamine and Anti-Phosphatidylserine Antibodies—Association with Renal Involvement, Atherosclerosis, Cardiovascular Manifestations, Raynaud Phenomenon and Disease Activity in Polish Patients with Systemic Lupus Erythematosus

Objective. To evaluate the association between anti-phosphatidylethanolamine (aPE) and anti-phosphatidylserine (aPS) antibodies and cardiovascular risk, organ involvement and disease activity in systemic lupus erythematosus (SLE) patients. Methods. We studied 93 SLE patients and 30 controls. We analyzed levels of anti-phospholipid antibodies, including aPS and aPE, the profiles of antinuclear, anti-neutrophil cytoplasmic (ANCA) and anti-endothelial antibodies, carotid intima-media thickness (cITM) and atherosclerotic plaque presence, ankle-brachial and high resistance indices, atherosclerotic risk factors, organ manifestations and treatment. Results. Levels of aPS and aPE were significantly higher in SLE patients in comparison with the controls (p = 0.038 and p = 0.044, respectively). aPS was associated with the risk of Raynaud’s phenomenon (p = 0.021) development. aPE increased the risk of renal involvement (p = 0.049), cerebral stroke (p = 0.050), high vlues of cIMT (p = 0.041) development as well as occurrence of selected serological markers associated with activity of the disease such as anti-double stranded DNA (p = 0.021). The long duration of regular smoking (p = 0.021) and the high number of cigarettes/day (p = 0.015) were significantly associated with the risk of aPE occurrence. Conclusions. Patients with aPS and aPE are at risk of vascular involvement. Especially the presence of aPE may significantly increase the risk of thrombotic complications development in SLE patients without classical serological markers of APS. Finally, aPE might be used as a marker of disease activity and risk of renal injury development in this patient group. The classical atherosclerotic markers including lipid indices play an important role in complex analysis of cardiovascular risk in lupus patients and enable to identify patients at the highest risk and implement effective preventive, diagnostic and therapeutic procedures.

Lack of Association between Serum Interleukin-23 and Interleukin-27 Levels and Disease Activity in Patients with Active Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a chronic systemic autoimmune disease characterized by the production of multiple autoantibodies, resulting in tissue and organ damage. Recent studies have revealed that interleukin-23 (IL-23) and interleukin-27 (IL-27) may be therapeutically relevant in selected SLE manifestations. This study aimed to identify associations between serum IL-27 and IL-23 levels and disease activity in Polish patients with different manifestations of SLE: neuropsychiatric lupus (NPSLE), and lupus nephritis (LN). Associations between interleukin levels and oligo-specific antibodies against double-stranded DNA (dsDNA), dose of glucocorticoids, and type of treatment were also analyzed. An enzyme-linked immunosorbent assay was used to assess anti-dsDNA antibodies and analyze the serum concentration of IL-27 and IL-23 from 72 patients aged 19-74 years with confirmed active SLE. Disease activity was measured using the Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI 2-K). No significant correlations between interleukin levels and SLEDAI score, anti-dsDNA, corticosteroid dose, or type of treatment were noted. Patients with NPSLE and LN presented the highest median scores of SLEDAI.

Increased IL-23R+ Th Cells Population Exhibits Higher SLEDAI-2K Scores in Systemic Lupus Erythematosus Patients

The IL-23/IL-17 axis plays causative roles in the development and progression of systemic lupus erythematosus (SLE). However, it remains unclear if the IL-17RA⁺ and IL-23R⁺ T helper (Th) cells populations are associated with the serum IL-17 and IL-23 levels, or with the immunological parameters and disease activities in SLE patients. Herein, we examined the proportion of IL-17RA⁺ and IL-23R⁺ Th cells and serum levels of IL-17 and IL-23 in established SLE patients (n = 50) compared with healthy controls (n = 50). The associations of these interleukins and their receptors with immunological parameters [anti-nuclear antibody (ANA), anti-dsDNA antibody, and C-reactive protein (CRP)] and SLE disease activity (SLEDAI-2K scores) in SLE patients were assessed. CD3⁺CD4⁺ Th cells of SLE patients demonstrated significantly elevated IL-17RA⁺ (p = 1.12 x 10^-4) or IL-23R⁺ (p = 1.98 x 10^-29) populations compared with the healthy controls. Serum IL-17 levels were significantly lower in SLE patients compared with the healthy controls (p = 8.32 x 10^-5), while no significant difference was observed for the IL-23 serum levels between both groups. IL-23R⁺ Th cells population was significantly associated with higher SLEDAI-2K scores (p = 0.017). In multivariate analysis, the proportion of IL-23R⁺ Th cells remained significantly associated with higher SLEDAI-2K scores independent of prednisolone intake (p = 0.027). No associations were observed between the interleukin parameters (i.e., IL-17, IL-23, IL-17RA⁺ Th cells, and IL-23R⁺ Th cells) with ANA, anti-dsDNA, and CRP status, suggesting that the IL-17/IL-23 axis acts independently of these immunological parameters. In conclusion, our results support that therapeutic inhibition of the IL-23/IL-17 axis receptors on Th cells, particularly IL-23R, is potentially relevant in SLE patients.

T Cells in Systemic Lupus Erythematosus

T-cell dysregulation has been implicated in the loss of tolerance and overactivation of B cells in systemic lupus erythematosus (SLE). Recent studies have identified T-cell subsets and genetic, epigenetic, and environmental factors that contribute to pathogenic T-cell differentiation, as well as disease pathogenesis and clinical phenotypes in SLE. Many therapeutics targeting T-cell pathways are under development, and although many have not progressed in clinical trials, the recent approval of the calcineurin inhibitor voclosporin is encouraging. Further study of T-cell subsets and biomarkers of T-cell action may pave the way for specific targeting of pathogenic T-cell populations in SLE.

Role of the IL-23/IL-17 Pathway in Rheumatic Diseases: An Overview

Interleukin-23 (IL-23) is a pro-inflammatory cytokine composed of two subunits, IL-23A (p19) and IL-12/23B (p40), the latter shared with Interleukin-12 (IL-12). IL-23 is mainly produced by macrophages and dendritic cells, in response to exogenous or endogenous signals, and drives the differentiation and activation of T helper 17 (Th17) cells with subsequent production of IL-17A, IL-17F, IL-6, IL-22, and tumor necrosis factor α (TNF-α). Although IL-23 plays a pivotal role in the protective immune response to bacterial and fungal infections, its dysregulation has been shown to exacerbate chronic immune-mediated inflammation. Well-established experimental data support the concept that IL-23/IL-17 axis activation contributes to the development of several inflammatory diseases, such as PsA, Psoriasis, Psoriatic Arthritis; AS, Ankylosing Spondylitis; IBD, Inflammatory Bowel Disease; RA, Rheumatoid Arthritis; SS, Sjogren Syndrome; MS, Multiple Sclerosis. As a result, emerging clinical studies have focused on the blockade of this pathogenic axis as a promising therapeutic target in several autoimmune disorders; nevertheless, a greater understanding of its contribution still requires further investigation. This review aims to elucidate the most recent studies and literature data on the pathogenetic role of IL-23 and Th17 cells in inflammatory rheumatic diseases.

Elevated IL-38 inhibits IL-23R expression and IL-17A production in thyroid-associated ophthalmopathy

IL-23/IL-23R and PGE₂/EP2+EP4 have been recognized as crucial signals that promote Th17 differentiation in many autoimmune diseases, including thyroid-associated ophthalmopathy (TAO). However, the interactive role of IL-23R in IL-23/Th17 signaling and PGE₂/Th17 signaling has not been clarified in TAO. Furthermore, the role of IL-38, a novel anti-inflammatory cytokine, has not been explored in TAO. Thus, we aimed to investigate the roles of IL-23R and IL-38 in the pathogenesis of TAO. Activated peripheral blood mononuclear cells (PBMCs) were cultured with or without IL-23 and PGE₂. The results showed that IL-23R and IL-17A were upregulated to different degrees and reached the highest levels with both stimuli, indicating that IL-23 induced PBMCs to secrete PGE₂, which further boosted the proportion of IL-23R+CD4+T cells to promote IL-17A secretion. Pretreatment with antagonists aimed at EP2/EP4 receptors diminished PGE₂-induced upregulation of IL-23R and IL-17A. IL-38 in TAO patients was increased. Activated orbital fibroblasts (OFs) and PBMCs were pretreated with different concentrations of IL-38. IL-23R and IL-17A expression in circulating PBMCs and IL-6 and IL-8 in resident OFs were suppressed by IL-38 at relatively low concentrations. Our findings suggest that the feedback loop of IL-23/IL-23R/PGE₂/EP2+EP4/IL-23R/IL-17A plays a significant role in the pathogenesis of TAO and that IL-23R is one of the key targets. Increased IL-38 in TAO could not only inhibit the expression of IL-23R and IL-17A in PBMCs but also suppress inflammation in OFs. Therapies targeting IL-23R may be effective, and IL-38 could be a potential therapeutic approach for TAO.

Discovery of BMS-986202: A Clinical Tyk2 Inhibitor that Binds to Tyk2 JH2

A search for structurally diversified Tyk2 JH2 ligands from 6 (BMS-986165), a pyridazine carboxamide-derived Tyk2 JH2 ligand as a clinical Tyk2 inhibitor currently in late development for the treatment of psoriasis, began with a survey of six-membered heteroaryl groups in place of the N-methyl triazolyl moiety in 6. The X-ray co-crystal structure of an early lead (12) revealed a potential new binding pocket. Exploration of the new pocket resulted in two frontrunners for a clinical candidate. The potential hydrogen bonding interaction with Thr599 in the pocket was achieved with a tertiary amide moiety, confirmed by the X-ray co-crystal structure of 29. When the diversity search was extended to nicotinamides, a single fluorine atom addition was found to significantly enhance the permeability, which directly led to the discovery of 7 (BMS-986202) as a clinical Tyk2 inhibitor that binds to Tyk2 JH2. The preclinical studies of 7, including efficacy studies in mouse models of IL-23-driven acanthosis, anti-CD40-induced colitis, and spontaneous lupus, will also be presented.

IL-17 and IL-23 levels in patients with early-stage chronic lymphocytic leukemia

OBJECTIVE

Cytokines produced by bone marrow mesenchymal stem cells are important components of the tumor microenvironment in chronic lymphocytic leukemia (CLL). The roles of IL-17 and IL-23 in both autoimmune diseases and tumor growth have been demonstrated. The role of the IL-17/23 axis in apoptosis has also been demonstrated in studies. Autoimmune cytopenias are common in CLL. In this study, we aimed to compare IL-17/IL-23 levels in early-stage CLL patients with healthy controls.

METHODS

After obtaining ethical approval from the local ethics committee, 22 patients with early-stage chronic lymphocytic leukemia and 21 healthy control groups were included in this study. IL-17 and IL-23 were analyzed using the enzyme-linked immunosorbent assay method.

RESULTS

The findings showed that the median IL-23 level was lower in men in the chronic lymphocytic leukemia group than women. There was a positive correlation between IL-17 and IL-23 levels in both the control group and the chronic lymphocytic leukemia group. There was no significant correlation between stage and IL-17 and IL-23 levels in chronic lymphocytic leukemia patients.

CONCLUSION

Results of studies conducted on IL-17 and/or IL-23 in chronic lymphocytic leukemia in the literature are not consistent. These inconsistent results can be explained by the fact that the immune system develops differently in each individual due to environmental factors, past infections, intestinal flora, vaccines, ethnicity, and even gender. Therefore, it can be hypothesized that the development and application of personalized immunotherapy strategies instead of standard therapy in chronic lymphocytic leukemia may increase therapeutic success rates.

Interleukin 23 is elevated in the serum of patients with SLE

Aim: Interleukin-23 (IL-23) is a cytokine that promotes the differentiation of T cells into pro-inflammatory Th17. We have previously shown that IL-23 is upregulated in systemic lupus erythematosus (SLE) patients and lupus prone mice. As SLE is highly heterogeneous, we asked whether IL-23 production correlates with different manifestations of the disease.Methods: We recruited 56 subjects who fulfilled the ACR criteria for SLE. Interleukin-23 was measured in the serum by ELISA.Results: IL-23 levels were positively correlated with the overall SLE disease activity as measured with the SLEDAI. Moreover, IL-23 correlated with the skin, renal domains of SLEDAI and arthritis but not with cytopenias or serositis. IL-23 did also correlate with anti-dsDNA antibody positivity and inversely correlated with C3 levels. We found no relationship between patients' demographics, prior disease manifestations, medications, or autoantibody profile and IL-23 levels. No immunomodulatory medication seemed to be affecting IL-23 levels suggesting that current medications used in SLE are not as effective in shutting down the IL-23/IL-17 axis. Conclusions: IL-23 levels track SLE disease activity mostly in the renal, skin and musculoskeletal domains. Our data suggest that IL-23 inhibitors may be helpful in combination with current standard of care in alleviating arthritis, renal and cutaneous manifestations of the disease.

Increased Prevalence of Systemic Lupus Erythematosus Comorbidity in Patients With Psoriatic Arthritis: A Population-based Case-control Study

OBJECTIVE

To assess the prevalence of systemic lupus erythematosus (SLE) in a psoriatic arthritis (PsA) cohort and to compare it to the general population using the database of a large healthcare provider.

METHODS

We analyzed the database of a PsA cohort (2002-2017), matched for age and sex, with randomly selected controls for demographics, clinical and laboratory manifestations, and dispensed medications. Statistical analysis used t test and chi-square test as appropriate. In the PsA group, incidence density sampling was performed matching PsA patients without SLE as controls to each case of PsA with SLE by age and follow-up time. Univariable and multivariable conditional logistic regression analyses were used to assess factors affecting SLE development.

RESULTS

The PsA and control groups consisted of 4836 and 24,180 subjects, respectively, with a median age of 56 ± 15 years, and of whom 53.8% were female. Eighteen patients (0.37%) in the PsA group and 36 patients (0.15%) in the control group were diagnosed with SLE (P = 0.001). SLE patients without PsA had higher anti-dsDNA and anticardiolipin antibodies. The usage of drugs with known potential to induce SLE was higher in the PsA than in the control group. Older age at PsA diagnosis, shorter PsA duration, and statin treatment were associated with SLE in PsA patients.

CONCLUSION

A 2.3-fold increase in the prevalence of SLE in PsA relative to the control group was found. Risk factors for SLE development included older age at PsA diagnosis, shorter PsA duration, and statin treatment. The association between PsA and SLE may affect treatment choices and medication development.

High interleukin-18 and low FOXP3 mRNAs in peripheral blood of women with severe systemic lupus erythematosus: a cross-sectional study

Gene expression analysis of peripheral blood cells may provide valuable information about the triggered molecular processes in systemic lupus erythematosus (SLE). The study aimed to quantify the mRNA in peripheral blood of seven target genes, including inflammatory cytokine genes (IL23A, IL12B, TNFA, IL18), and T regulatory-related genes (FOXP3, TGFB1, IL10) in patients with SLE and to correlate expression levels with disease activity and/or clinical manifestations. The relative quantification of target genes was performed using real-time polymerase chain reaction in peripheral blood obtained from 28 adult SLE females and 17 healthy women. The highest up-regulation in the blood of SLE patients was observed for IL23A with a median 9.54 (p < 0.0001), followed by TGFB1 (median: 2.07; p = 0.047) and IL10 (median: 1.84; p = 0.013). IL12B and TNFA were significantly down-regulated in patients compared to controls (median: 0.521; p = 0.0023, and median: 0.519; p = 0.0003, respectively). FOXP3 mRNA was lower among patients with higher degree of disease activity (median: 0.338; p = 0.029) and showed inverse correlation with Systemic Lupus Erythematosus Disease Activity Index (SLEDAI). IL18 mRNA correlated positively with the SLEDAI and was highly expressed during severe flares (median: 1.216; p = 0.021). IL18 up-regulation was associated with anti-dsDNA antibody positivity, while FOXP3 down-regulation with lupus nephritis. Our study pointed out the relationship of SLE disease activity and particular clinical manifestations with IL18 and FOXP3 expression, and the significant contribution of IL23A in the SLE immunopathogenesis. Hence, the peripheral blood cytokine mRNAs should be exploited as novel prognostic and diagnostic biomarkers.

Th1, Th2, and Th17 cytokines in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the breakdown of immune tolerance leading to excessive inflammation and tissue damage. Imbalance in the levels of cytokines represents one of the multifactorial causes of SLE pathogenesis and it contributes to disease severity. Deregulated levels of T helper type 1 (Th1), type 2 (Th2), and type 17 (Th17) cytokines have been associated with autoimmune inflammation. Growing evidence has shown deregulated levels of Th1, Th2, and Th17 cytokines in SLE patients compared to healthy controls associated with disease activity and severity. In this review, we describe and discuss the levels of Th1, Th2, and Th17 cytokines in SLE patients, and clinical trials involving Th1, Th2, and Th17 cytokines in SLE patients. In particular, with the exception of IL-2, IL-4, and TGF-β1, the levels of Th1, Th2, and Th17 cytokines are increased in SLE patients associated with disease severity. Current phase II or III studies involve therapeutic antibodies targeting IFN-α and type I IFN receptor, while low-dose IL-2 therapy is assessed in phase II clinical trials.

Relationship of Excess Weight with Clinical Activity and Dietary Intake Deficiencies in Systemic Lupus Erythematosus Patients

Obesity and nutrients intake deficiencies may contribute to the clinical manifestations and inflammatory processes in systemic lupus erythematosus (SLE). The aim of this study was to assess the relationship between nutritional status and dietary intake with clinical variables in Mexican-mestizo SLE patients. A cross-sectional study was conducted in 130 female SLE patients, classified by the 1997 SLE American College of Rheumatology (ACR) criteria; the clinical activity was evaluated by the Mexican-Systemic Lupus Erythematosus-Disease Activity Index (Mex-SLEDAI); body mass index (BMI) by the World Health Organization (WHO) criteria; the energy calculation and nutritional intake were performed by Nutritionist Pro Diet software. SLE patients with excess weight (BMI > 25 kg/m²) showed a higher score of clinical activity (Mex-SLEDAI = 2; p = 0.003), higher clinical activity prevalence (40.9%; p = 0.039) and a significant association for high clinical activity (odds ratio (OR) = 2.52; 95% confidence interval (CI) = 1.08-5.9; p = 0.033), in comparison with patients without excess weight (BMI < 25 kg/m²). In particular, the excess weight increased the Mex-SLEDAI score (β coefficient = 1.82; R² = 0.05; p = 0.005). Also, the SLE patients presented a high prevalence (%) of deficient consumption (cut-off point: <67% of dietary adequacy) of vitamin E (100%), iodine (96%), omega 3 (93.44%), biotin (78%), vitamin K (73.33%), iron (67%), vitamin D (63.3%), potassium (59%), folic acid (56.67%), pantothenic acid (43.3%), vitamin A (41.67%) and zinc (32%). In conclusion, in SLE patients the excess weight was associated with increased clinical activity and to the presence of deficiencies in some essential nutrients ingested.

Impaired AMPK‑CGRP signaling in the central nervous system contributes to enhanced neuropathic pain in high‑fat diet‑induced obese rats, with or without nerve injury

Obesity is associated with increased sensitivity to pain, including neuropathic pain, but the precise mechanisms are not fully understood. Recent evidence has revealed that AMP-activated protein kinase (AMPK) in the central nervous system (CNS) regulates the neuropeptide calcitonin gene-related peptide (CGRP), a principal neurotransmitter of the class C nerve fiber, which serves an important role in initiating and maintaining neuropathic pain. AMPK has been demonstrated to be downregulated in the CNS in obesity. The present study hypothesized that obesity may lead to increased sensitivity to neuropathic pain by downregulating AMPK and upregulating CGRP expression levels in the CNS. Sprague-Dawley rats consuming a high-fat diet (HF) for 12 weeks developed obesity; they exhibited significantly decreased levels of phospho (p)-AMPK and increased CGRP expression levels in the spinal cord (SC) and dorsal root ganglion (DRG), respectively, compared with rats consuming a low-fat (LF) diet. HF-fed rats that underwent spared nerve injury (SNI) also exhibited lower p-AMPK and higher CGRP expression levels in the SC and DRG, compared with the corresponding LF-diet rats. The 50% paw withdrawal threshold (PWT; as measured by Von Frey testing) was significantly lower in HF-fed compared with LF-fed rats, with or without SNI. Through intrathecal treatment, the AMPK activator 5-aminoimidazole-4-carboxamide riboside (AICAR) or the CGRP antagonist CGRP8-37 decreased CGRP expression levels and increased the 50% PWT; however, the AMPK inhibitor dorsomorphin augmented CGRP expression levels and further reduced the 50% PWT in HF-fed rats, but not LF-fed rats, with or without SNI. The results indicated that blocking the AMPK-CGRP pathway may enhance neuropathic pain in HF-induced obesity, with or without nerve injury. Targeting AMPK in the CNS may be a novel strategy for the prevention and treatment of obesity-associated neuropathic pain.

The Influence of Diet and Obesity on Gene Expression in SLE

This review provides an overview of the known effects of diet, obesity, and the intake of different nutrients on systemic lupus erythematosus (SLE). It summarizes and discusses the studies in rodents that identified how different diets can regulate gene expression in the disease, together with a description of the effects of diet on lupus patients’ inflammatory state and disease severity. The identification of selected dietary candidates that can modulate SLE onset and progression is analyzed in relation to possible targeted approaches that could ultimately ameliorate the management and prognosis of this disease.

IL-12 and IL-23/Th17 axis in systemic lupus erythematosus

IMPACT STATEMENT

Our article is focused on emerging pathogenetic pathways in systemic lupus erythematosus (SLE). Notably, IL-12 and IL-23 have been described as emerging cytokines in SLE pathogenesis. We know that IL-23 stimulates Th17 cells to produce IL-17. We try to point out the importance of IL-23/Th17 axis in SLE and to focus on the interaction between this axis and IL-12. Ustekinumab, a fully human IgG1κ monoclonal antibody directed towards the p40 shared subunit of IL-12 and IL-23, has been recently investigated in SLE, suggesting a potential novel therapeutic strategy in SLE. To our knowledge, there are no reviews which simultaneously focus on IL-12 an IL-23/Th17 axis in SLE. Thus, we believe our work will be of interest to the readers.

Impact of obesity on autoimmune arthritis and its cardiovascular complications

Obesity can instigate and sustain a systemic low-grade inflammatory environment that can amplify autoimmune disorders and their associated comorbidities. Metabolic changes and inflammatory factors produced by the adipose tissue have been reported to aggravate autoimmunity and predispose the patient to cardiovascular disease (CVD) and metabolic comorbidities. Rheumatoid arthritis (RA) and psoriatic arthritis (PsA) are autoimmune arthritic diseases, often linked with altered body mass index (BMI). Severe joint inflammation and bone destruction have a debilitating impact on the patient's life; there is also a staggering risk of cardiovascular morbidity and mortality. Furthermore, these patients are at risk of developing metabolic symptoms, including insulin resistance resulting in type 2 diabetes mellitus (T2DM). In addition, arthritis severity, progression and response to therapy can be markedly affected by the patient's BMI. Hence, a complex integrative pathogenesis interconnects autoimmunity with metabolic and cardiovascular disorders. This review aims to shed light on the network that connects obesity with RA, PsA, systemic lupus erythematosus and Sjӧgren's syndrome. We have focused on clarifying the mechanism by which obesity affects different cell types, inflammatory factors and traditional therapies in these autoimmune disorders. We conclude that to further optimize arthritis therapy and to prevent CVD, it is imperative to uncover the intricate relation between obesity and arthritis pathology.