Obesity-associated insulin resistance is characterized by a state of chronic, low-grade inflammation that is associated with the accumulation of M1 proinflammatory macrophages in adipose tissue. ...Although different evidence explains the mechanisms linking the expansion of adipose tissue and adipose tissue macrophage (ATM) polarization, in the current study we investigated the concept of lipid-induced toxicity as the pathogenic link that could explain the trigger of this response.
We addressed this question using isolated ATMs and adipocytes from genetic and diet-induced murine models of obesity. Through transcriptomic and lipidomic analysis, we created a model integrating transcript and lipid species networks simultaneously occurring in adipocytes and ATMs and their reversibility by thiazolidinedione treatment.
We show that polarization of ATMs is associated with lipid accumulation and the consequent formation of foam cell-like cells in adipose tissue. Our study reveals that early stages of adipose tissue expansion are characterized by M2-polarized ATMs and that progressive lipid accumulation within ATMs heralds the M1 polarization, a macrophage phenotype associated with severe obesity and insulin resistance. Furthermore, rosiglitazone treatment, which promotes redistribution of lipids toward adipocytes and extends the M2 ATM polarization state, prevents the lipid alterations associated with M1 ATM polarization.
Our data indicate that the M1 ATM polarization in obesity might be a macrophage-specific manifestation of a more general lipotoxic pathogenic mechanism. This indicates that strategies to optimize fat deposition and repartitioning toward adipocytes might improve insulin sensitivity by preventing ATM lipotoxicity and M1 polarization.
Rheumatoid arthritis (RA) is an autoimmune and chronic inflammatory disease primarily affecting the joints, and closely related to specific autoantibodies that mostly target modified self-epitopes. ...Relevant findings in the field of RA pathogenesis have been described. In particular, new insights come from studies on synovial fibroblasts and cells belonging to the innate and adaptive immune system, which documented the aberrant production of inflammatory mediators, oxidative stress and NETosis, along with relevant alterations of the genome and on the regulatory epigenetic mechanisms. In recent years, the advances in the understanding of RA pathogenesis by identifying key cells and cytokines allowed the development of new targeted disease-modifying antirheumatic drugs (DMARDs). These drugs considerably improved treatment outcomes for the majority of patients. Moreover, numerous studies demonstrated that the pharmacological therapy with biologic DMARDs (bDMARDs) promotes, in parallel to their clinical efficacy, significant improvement in all these altered molecular mechanisms. Thus, continuous updating of the knowledge of molecular processes associated with the pathogenesis of RA, and on the specific effects of bDMARDs in the correction of their dysregulation, are essential in the early and correct approach to the treatment of this complex autoimmune disorder. The present review details basic mechanisms related to the physiopathology of RA, along with the core mechanisms of response to bDMARDs.
Tocilizumab (TCZ) is an effective treatment for rheumatoid arthritis (RA). However, the changes that occurred after TCZ therapy on endothelial dysfunction, monocyte activity, NETosis, and oxidative ...stress, the principal effectors of atherosclerosis and cardiovascular disease, have not been analyzed yet. A total of 20 RA patients received 162 mg per week subcutaneous TCZ for 6 months. Endothelial function was measured through postocclusive hyperemia using Laser Doppler. Oxidative stress markers in monocytes and neutrophils were analyzed by flow cytometry. NETosis was measured through SYTOX staining of DNA fibers and the expression of myeloperoxidase and neutrophil elastase. Percentage of low-density granulocytes was analyzed through flow cytometry. Gene expression and phosphorylation of intracellular pathways was analyzed in monocytes. TCZ improved endothelial function and decreased oxidative stress in RA leukocytes. Percentage of low-density granulocytes and NETosis generation were reduced. The proinflammatory and prothrombotic status of RA monocytes was also reversed through a modulation of specific intracellular pathways. All these results were recapitulated after in vitro treatment with TCZ of monocytes and neutrophils purified from RA patients and cocultured with endothelial cells. TCZ might reduce the proatherothrombotic profile in RA patients through the restoration of the endothelial function, oxidative stress reduction, inhibition of monocytes' prothrombotic and inflammatory profile, and abridged NETosis generation.
Liver disease is one of the most important causes of morbidity and mortality worldwide whose prevalence is dramatically increasing. The first sign of hepatic damage is inflammation which could be ...accompanied by the accumulation of fat called non-alcoholic fatty liver disease (NAFLD), causing damage in the hepatocytes. This stage can progress to fibrosis where the accumulation of fibrotic tissue replaces healthy tissue reducing liver function. The next stage is cirrhosis, a late phase of fibrosis where a high percentage of liver tissue has been replaced by fibrotic tissue and liver functionality is substantially impaired. There is a close interplay of cardiovascular disease (CVD) and hepatic alterations, where different mechanisms mediating this relation between the liver and systemic vasculature have been described. In chronic inflammatory diseases such as rheumatoid arthritis (RA) and psoriatic arthritis (PsA), in which the CVD risk is high, hepatic alterations seem to be more prevalent compared to the general population and other rheumatic disorders. The pathogenic mechanisms involved in the development of this comorbidity are still unraveled, although chronic inflammation, autoimmunity, treatments, and metabolic deregulation seem to have an important role. In this review, we will discuss the involvement of liver disease in the cardiovascular risk associated with inflammatory arthritis, the pathogenic mechanisms, and the recognized factors involved. Likewise, monitoring of the liver disease risk in routine clinical practice through both, classical and novel techniques and indexes will be exposed. Finally, we will examine the latest controversies that have been raised about the effects of the current therapies used to control the inflammation in RA and PsA, in the liver damage of those patients, such as methotrexate, leflunomide or biologics.
Rheumatoid Arthritis (RA), Systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS) are the systemic autoimmune diseases (SADs) most associated with an increased risk of developing ...cardiovascular (CV) events. Cardiovascular disease (CVD) in SADs results from a complex interaction between traditional CV-risk factors, immune deregulation and disease activity. Oxidative stress, dyslipidemia, endothelial dysfunction, inflammatory/prothrombotic mediators (cytokines/chemokines, adipokines, proteases, adhesion-receptors, NETosis-derived-products, and intracellular-signaling molecules) have been implicated in these vascular pathologies. Genetic and genomic analyses further allowed the identification of signatures explaining the pro-atherothrombotic profiles in RA, SLE and APS. However, gene modulation has left significant gaps in our understanding of CV co-morbidities in SADs. MicroRNAs (miRNAs) are emerging as key post-transcriptional regulators of a suite of signaling pathways and pathophysiological effects. Abnormalities in high number of miRNA and their associated functions have been described in several SADs, suggesting their involvement in the development of atherosclerosis and thrombosis in the setting of RA, SLE and APS. This review focusses on recent insights into the potential role of miRNAs both, as clinical biomarkers of atherosclerosis and thrombosis in SADs, and as therapeutic targets in the regulation of the most influential processes that govern those disorders, highlighting the potential diagnostic and therapeutic properties of miRNAs in the management of CVD.
Antiphospholipid Syndrome (APS) is an autoimmune disorder, characterized by pregnancy morbidity and/or a hyper coagulable state involving the venous or the arterial vasculature and associated with ...antiphospholipid antibodies (aPL), including anti-cardiolipin antibodies (aCL), anti-beta2-glycoprotein I (anti-ß2GPI), and Lupus anticoagulant (LA). In recent years there have been many advances in the understanding of the molecular basis of vascular involvement in APS. APS is of multifactorial origin and develops in genetically predisposed individuals. The susceptibility is determined by major histocompatibility complex (MHC). Different HLA-DR and HLA-DQ alleles have been reported in association with APS. Moreover, MHC II alleles may determine the autoantibody profile and, as such, the clinical phenotype of this disease. Besides, polymorphisms in genes related to the vascular system are considered relevant factors predisposing to clinical manifestations. Antiphospholipid antibodies (aPL) induce genomic and epigenetic alterations that support a pro- thrombotic state. Thus, a specific gene profile has been identified in monocytes from APS patients -related to aPL titres
and promoted
by aPL- explaining their cardiovascular involvement. Regarding epigenetic approaches, we previously recognized two miRNAs (miR-19b/miR-20a) as potential modulators of tissue factor, the main receptor involved in thrombosis development in APS. aPLs can further promote changes in the expression of miRNA biogenesis proteins in leukocytes of APS patients, which are translated into an altered miRNA profile and, consequently, in the altered expression of their protein targets related to thrombosis and atherosclerosis. MicroRNAs are further released into the circulation, acting as intercellular communicators. Accordingly, a specific signature of circulating miRNAs has been recently identified in APS patients as potential biomarkers of clinical features. Genomics and epigenetic biomarkers might also serve as indices for disease progression, clinical pharmacology, or safety, so that they might be used to individually predict disease outcome and guide therapeutic decisions. In that way, in the setting of a clinical trial, novel and specific microRNA-mRNA regulatory networks in APS, modified by effect of Ubiquinol treatment, have been identified. In this review, current and previous studies analyzing genomic/epigenetic changes related to the clinical profile of APS patients, and their modulation by effect of specific therapies, are discussed.
The aim of this study was to investigate the microRNA expression pattern in neutrophils from rheumatoid arthritis patients and its contribution to their pathogenic profile and to analyze the effect ...of specific autoantibodies or inflammatory components in the regulation of microRNAs in rheumatoid arthritis neutrophils and its modulation by biological therapies. Neutrophils were isolated from paired peripheral blood and synovial fluid samples of 40 patients with rheumatoid arthritis and from peripheral blood of 40 healthy donors. A microRNA array was performed using nCounter technology. Neutrophils from healthy donors were treated in vitro with antibodies to citrullinated protein antigens isolated from rheumatoid arthritis patients and tumor necrosis factor-α or interleukin-6. A number of cytokines and chemokines were analyzed. In vitro treatments of rheumatoid arthritis-neutrophils with tocilizumab or infliximab were carried out. Transfections with pre-microRNAs and DICER downregulation were further performed. Rheumatoid arthritis-neutrophils showed a global downregulation of microRNAs and genes involved their biogenesis, alongside with an upregulation of various potential mRNA targets related to migration and inflammation. Decreased levels of microRNAs and DICER correlated with autoimmunity, inflammation and disease activity. Citrullinated protein antigens and tumor necrosis factor-α decreased the expression of numerous microRNAs and their biogenesis-related genes, increasing their potential mRNA targets. Infliximab reversed those effects. Transfections with pre-miRNAs-223, -126 and -148a specifically modulated genes regulating inflammation, survival and migration. DICER depletion influenced the neutrophils inflammatory profile. Taking together rheumatoid arthritis neutrophils exhibit a global low abundance of microRNAs induced by autoantibodies and inflammatory markers, which might contribute to their pathogenic activation. microRNA biogenesis is significantly impaired in rheumatoid arthritis-neutrophils and further associated with a greater downregulation of microRNAs mainly related to migration and inflammation in synovial neutrophils. Finally, anti-tumor necrosis factor-α and anti-interleukin-6 receptor treatments can modulate microRNA levels in the neutrophils, minimizing their inflammatory profile.
Background:
The relationship of psoriasis and spondyloarthritis (SpA) is well-known, and the age of appearance of different manifestations has been described as a determinant of SpA phenotype. ...However, differences between Spa with psoriasis and psoriatic arthritis (PsA) are still controversial.
Objectives:
To evaluate whether the time of onset of psoriasis relative to the appearance of rheumatic symptoms in patients with SpA is associated with a clinical phenotype, a rheumatologist’s diagnosis and the evolution of the disease.
Design:
This was a cross-sectional study with data extracted from the REGISPONSER (Spondyloarthritis Registry of the Spanish Rheumatology Society) registry.
Methods:
All patients had data available for both psoriasis and SpA dates of onset. Patients were classified into two groups depending on the time of appearance of psoriasis: psoriasis before or after rheumatic symptoms. The clinical characteristics, disease activity, radiographic damage, functional ability and received treatments were compared between the two groups. Moreover, the rheumatologists’ diagnoses were compared between the two groups. Univariate and multivariate logistic regressions were conducted to evaluate the factors associated with each group.
Results:
A total of 433/2367 (18.3%) patients included in the REGISPONSER database had psoriasis: 330 (76.2%) patients had psoriasis before rheumatic symptoms, and 103 (23.8%) had psoriasis after rheumatic symptoms. Patients with psoriasis before rheumatic symptoms had a shorter disease duration and a lower body mass index, a lower prevalence of both HLA-B27 antigens and anterior uveitis, a higher prevalence of dactylitis and an increase in levels of the erythrocyte sedimentation rate (ESR). Furthermore, a higher prevalence of PsA diagnoses (78.1% versus 56.4%) and a more frequent fulfilment of the CASPAR criteria (57.5% versus 42.2%) were found in these patients. The use of DMARDs was not significantly different between the two groups.
Conclusion:
The time of appearance of psoriasis is associated with the clinical phenotype of SpA and could determine a diagnosis of PsA by rheumatologists.
1) To characterize the inflammatory proteome of synovial fluid (SF) from patients with Psoriatic Arthritis (PsA) using a high-quality throughput proteomic platform, and 2) to evaluate its potential ...to stratify patients according to clinical features.
Inflammatory proteome profile of SF from thirteen PsA patients with active knee arthritis were analyzed using proximity extension assay (PEA) technology (Olink Target 96 Inflammation panel). Four patients with OA were included as control group.
Seventy-nine inflammation-related proteins were detected in SF from PsA patients (SF-PsA). Unsupervised analyzes of the molecular proteome profile in SF-PsA identified two specific phenotypes characterized by higher or lower levels of inflammation-related proteins. Clinically, SF-PsA with higher levels of inflammatory proteins also showed increased systemic inflammation and altered glucose and lipid metabolisms. Besides, SF from PsA patients showed 39 out of 79 proteins significantly altered compared to SF-OA specifically related to cell migration and inflammatory response. Among these, molecules such as TNFα, IL-17A, IL-6, IL-10, IL-8, ENRAGE, CCL20, TNFSF-14, OSM, IFNγ, MCP-3, CXCL-11, MCP4, CASP-8, CXCL-6, CD-6, ADA, CXCL-10, TNFβ and IL-7 showed the most significantly change.
This is the first study that characterizes the inflammatory landscape of synovial fluid of PsA patients by analyzing a panel of 92 inflammatory proteins using PEA technology. Novel SF proteins have been described as potential pathogenic molecules involved in the pathogenesis of PsA. Despite the flare, inflammatory proteome could distinguish two different phenotypes related to systemic inflammation and lipid and glucose alterations.
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