Treatment Of Systemic Sclerosis Research Articles

Upregulation of GPX4 drives ferroptosis resistance in scleroderma skin fibroblasts

The pathogenesis of systemic sclerosis (SSC) fibrosis involves the rapid proliferation of skin fibroblasts, and current anti-fibrotic treatments are limited. This study investigated the relationship between ferroptosis and SSC skin fibroblasts. We observed that erastin-induced ferroptosis was suppressed in SSC fibroblasts. RSL3, a direct inhibitor of Glutathione Peroxidase 4 (GPX4), significantly reduced the viability of the fibroblasts, and upregulation of GPX4 in the SSC fibroblasts contributed to ferroptosis resistance. Furthermore, we demonstrated that transferrin receptor 1 (TfR1) was a crucial transporter for iron deposition in the fibroblasts. Collectively, our results highlight that GPX4 inhibition could enhance the sensitivity to ferroptosis by SSC fibroblasts, which showed distinct characteristics of iron metabolism that were not observed in normal fibroblasts in this study. Taken together, these results suggest that targeting ferroptosis could be a therapeutic strategy for the treatment of SSC.

The Potential of Twendee X® as a Safe Antioxidant Treatment for Systemic Sclerosis.

Systemic sclerosis (SSc) is an autoimmune disease characterized by systemic skin hardening, which combines Raynaud's phenomenon and other vascular disorders, skin and internal organ fibrosis, immune disorders, and a variety of other abnormalities. Symptoms vary widely among individuals, and personalized treatment is sought for each patient. Since there is no fundamental cure for SSc, it is designated as an intractable disease with patients receiving government subsidies for medical expenses in Japan. Oxidative stress (OS) has been reported to play an important role in the cause and symptoms of SSc. HOCl-induced SSc mouse models are known to exhibit skin and visceral fibrosis, vascular damage, and autoimmune-like symptoms observed in human SSc. The antioxidant combination Twendee X® (TwX) is a dietary supplement consisting of vitamins, amino acids, and CoQ10. TwX has been proven to prevent dementia in humans with mild cognitive impairment and significantly improve cognitive impairment in an Alzheimer's disease mouse model by regulating OS through a strong antioxidant capacity that cannot be achieved with a single antioxidant ingredient. We evaluated the effectiveness of TwX on various symptoms of HOCl-induced SSc mice. TwX-treated HOCl-induced SSc mice showed significantly reduced lung and skin fibrosis compared to untreated HOCl-induced SSc mice. TwX also significantly reduced highly oxidized protein products (AOPP) in serum and suppressed Col-1 gene expression and activation of B cells involved in autoimmunity. These findings suggest that TwX has the potential to be a new antioxidant treatment for SSc without side effects.

Immunotherapy Strategy for Systemic Autoimmune Diseases: Betting on CAR-T Cells and Antibodies.

Systemic autoimmune diseases (SAIDs), such as systemic lupus erythematosus (SLE), systemic sclerosis (SSc) and rheumatoid arthritis (RA), are fully related to the unregulated innate and adaptive immune systems involved in their pathogenesis. They have similar pathogenic characteristics, including the interferon signature, loss of tolerance to self-nuclear antigens, and enhanced tissue damage like necrosis and fibrosis. Glucocorticoids and immunosuppressants, which have limited specificity and are prone to tolerance, are used as the first-line therapy. A plethora of novel immunotherapies have been developed, including monoclonal and bispecific antibodies, and other biological agents to target cellular and soluble factors involved in disease pathogenesis, such as B cells, co-stimulatory molecules, cytokines or their receptors, and signaling molecules. Many of these have shown encouraging results in clinical trials. CAR-T cell therapy is considered the most promising technique for curing autoimmune diseases, with recent successes in the treatment of SLE and SSc. Here, we overview novel therapeutic approaches based on CAR-T cells and antibodies for targeting systemic autoimmune diseases.

Does the Impact of COVID-19 on Patients With Systemic Sclerosis Change Over Time?

The outcome of patients with COVID-19 improved over the pandemic, including patients with systemic rheumatic diseases. However, data on patients with systemic sclerosis (SSc) are lacking. This study aimed to assess the outcome of patients with both SSc and COVID-19 over several waves. Patients with both SSc and COVID-19 who were registered in the European Scleroderma Trials and Research group (EUSTAR) were collected between April 2020 and April 2021. Patients were assigned to waves 1, 2, or 3 depending on the date of their COVID-19 diagnosis. Primary endpoints were death, intensive care unit stay, or ventilatory support (severe outcome). Subgroup analyses of patients who were hospitalized or died were conducted. General and SSc-specific characteristics and treatment were compared over the waves. Descriptive statistics and multivariate logistic regression were applied. A total of 333 patients were included; 57 patients (17%) had a severe outcome, and 30 patients (9%) died. Compared to wave 1, significantly fewer patients with SSc suffered from severe COVID-19 in waves 2 and 3 (28.2% vs 9.8% and 12.7%; P < 0.001), fewer patients required hospitalization (46.7% vs 19.6% and 25.5%; P < 0.001) or ventilatory support (24.0% vs 8.7% and 10.9%; P = 0.001), and fewer patients died (15.7% vs 5.0% and 7.5%; P = 0.011). Patients were significantly younger, more often men, had less frequent arterial hypertension, and less SSc cardiac involvement over waves 1 to 3. Patients received significantly less medium to high doses of corticosteroids as they did SSc treatment. The outcome of patients with both SSc and COVID-19 improved significantly over time because of intrinsic and extrinsic factors.

Fibroblast Subpopulations in Systemic Sclerosis: Functional Implications of Individual Subpopulations and Correlations with Clinical Features

Fibroblasts constitute a heterogeneous population of cells. In this study, we integrated single-cell RNA-sequencing and bulk RNA-sequencing data as well as clinical information to study the role of individual fibroblast populations in systemic sclerosis (SSc). SSc skin demonstrated an increased abundance of COMP+, COL11A1+, MYOC+, CCL19+, SFRP4/SFRP2+, and PRSS23/SFRP2+ fibroblasts signatures and decreased proportions of CXCL12+ and PI16+ fibroblast signatures in the Prospective Registry of Early Systemic Sclerosis and Genetics versus Environment in Scleroderma Outcome Study cohorts. Numerical differences were confirmed by multicolor immunofluorescence for selected fibroblast populations. COMP+, COL11A1+, SFRP4/SFRP2+, PRSS23/SFRP2+, and PI16+ fibroblasts were similarly altered between normal wound healing and patients with SSc. The proportions of profibrotic COMP+, COL11A1+, SFRP4/SFRP2+, and PRSS23/SFRP2+ and proinflammatory CCL19+ fibroblast signatures were positively correlated with clinical and histopathological parameters of skin fibrosis, whereas signatures of CXCL12+ and PI16+ fibroblasts were inversely correlated. Incorporating the proportions of COMP+, COL11A1+, SFRP4/SFRP2+, and PRSS23/SFRP2+ fibroblast signatures into machine learning models improved the classification of patients with SSc into those with progressive versus stable skin fibrosis. In summary, the profound imbalance of fibroblast subpopulations in SSc may drive the progression of skin fibrosis. Specific targeting of disease-relevant fibroblast populations may offer opportunities for the treatment of SSc and other fibrotic diseases.

Symposium 3

Systemic sclerosis (SSc) remains a refractory condition with poor functional and survival outcomes. This is attributable primarily to the extremely diverse clinical course and distribution of organ involvement. The pathogenesis of SSc includes microangiopathy and chronic inflammation, leading to accumulation of extracellular matrix and resultant irreversible fibrosis resulting in distortion of the normal tissue architecture. This pathogenic process is analogous to that observed in rheumatoid arthritis, in which persistent synovitis leads to articular cartilage and bone destruction, resulting in functional impairment due to joint deformity. Therefore, successful experiences in developing treatment strategies in patients with rheumatoid arthritis can also be applied to SSc. These include early diagnosis and intervention, treat-to-target strategy aiming at achievement of clinical remission or low-disease activity, prediction of disease progression and prognosis, and disease modification by pharmacologic treatment. Immunosuppressants targeting lymphocytes, including mycophenolate mofetil and cyclophosphamide, have been the mainstream of the treatment of SSc, based on treatment evidence showing prevention of decline in forced vital capacity, promotion of improving modified Rodnan skin thickness score, and improved patient-reported outcomes. However, survival benefit has not been shown in long-term follow-up of patients treated with non-specific immunosuppressants. Recently, drugs targeting a variety of molecules involved in the pathologic process of SSc, such as tocilizumab and nintedanib, have been shown to prevent progression of certain organ involvement in clinical trials, resulting in expanding treatment options. Implementation of those potential disease-modifying therapies in management of SSc requires adequate assessment of disease activity and treatment goal setting. In addition, clinical characteristics that predict the progression of organ manifestations, such as skin sclerosis and interstitial lung disease, need to be identified as prognosis factors. Like other rheumatic diseases, early interventions have been shown to be more effective than delayed intervention. This lecture features current standings and challenges of treat-to-target strategy in SSc patients.

Dangui Huoxue Preparation (DHP) Ameliorates Skin Fibrosis, Inflammation, and Vasculopathy in the Bleomycin-Induced Murine Model of Systemic Sclerosis.

Systemic sclerosis (SSc) is an immune-mediated rheumatic disease that is characterized by fibrosis of the skin and internal organs and vasculopathy with poor prognosis. Dangui Huoxue Preparation (DHP) is a clinically effective traditional Chinese herbal formula for the treatment of SSc in the hospital. This study aims to investigate the therapeutic effects and underlying molecular mechanisms of DHP in the treatment of SSc. SSc mice models are induced by bleomycin (BLM). Tissues of DHP group, normal control group, and positive control drug Sanqi Tongshu Capsule (STC) group are collected for inflammation, fibrosis, and vasculopathy. Also, the human dermal fibroblasts (HDF) stimulated with TGF-β1 are analyzed for in vitro study. The expression levels of MCP-1, IFN-γ, IL-1β, IL-10, Fizz1, iNOS, and IL12p40, and the mRNA levels of Col1a1, Col1a2, Col3a1, and Col5a1 are significantly decreased in all DHP groups and STC group compare with those in the BLM group. The main drug of DHP inhibits the proliferation and migration of HDF, reduces Ctgf, Itgb3, Itgb5 expression, and also inhibits the Smad3 pathway. In conclusion, DHP can ameliorate SSc skin inflammation, fibrosis, and vasculopathy, possibly suppressing the TGF-β1/Smad3 signaling pathway through extracellular and intracellular mechanisms.

The Autoantibody Array Assay: A Novel Autoantibody Detection Method.

Systemic sclerosis (SSc) and dermatomyositis (DM) are autoimmune collagen diseases. Specific autoantibodies are known to be involved in their pathogeneses, each presenting with a different clinical manifestation. Although immunoprecipitation is the gold standard method for detecting autoantibodies, it is difficult to perform in all cases owing to the use of radioisotopes. In this study, we developed a new detection method for SSc and DM autoantibodies (A-cube) using cell-free protein synthesis and examined its validity. Proteins were synthesized using wheat germ cell-free protein synthesis. A total of 100 cases of SSc, 50 cases of DM, and 82 healthy controls were examined. The validity of the method was examined by a comparison with existing test results. Anti-centromere antibody, anti-topoisomerase I antibody, anti-RNA polymerase III antibody, anti-U1RNP anti-body, anti-Jo-1 antibody, anti-TIF1γ antibody, anti-Mi-2 antibody, and anti-ARS antibody were tested for. The results suggested that A-cube is comparable with existing testing methods or has a high sensitivity or specificity. In addition, there was a case in which the diagnosis was reconsidered using the A-cube. The quality of the A-cube was ensured, and its usefulness for a comprehensive analysis was demonstrated. The A-cube can therefore contribute to the clinical assessment and treatment of SSc and DM.

Arsenic trioxide demonstrates efficacy in a mouse model of preclinical systemic sclerosis

BackgroundUncontrolled T-cell activation plays a key role in systemic sclerosis (SSc). Arsenic trioxide (ATO) has immunological effects and has demonstrated potential in preclinical SSc models. In this study, we assessed the efficacy of ATO in Fra2 transgenic (Fra2TG) mice, which develop severe vascular remodeling of pulmonary arterioles and nonspecific interstitial pneumonia-like lung disease, closely resembling human SSc-associated pulmonary hypertension, therefore partially resembling to the SSc human disease.MethodsThe efficacy of ATO in Fra2TG mice was evaluated through histological scoring and determination of cell infiltration. Fibrotic changes in the lungs were assessed by measuring collagen content biochemically, using second harmonic generation to measure fibrillar collagen, and imaging via computed tomography. Cardiovascular effects were determined by measuring right ventricular systolic pressure and vessel remodeling. The mechanism of action of ATO was then investigated by analyzing lung cell infiltrates using flow cytometry and bulk RNA with sequencing techniques.ResultsAfter ATO treatment, the Ashcroft histological score was substantially decreased by 33% in ATO-treated mice compared to control mice. Other investigations of fibrotic markers showed a trend of reduction in various measurements of fibrosis, but the differences did not reach significance. Further cardiovascular investigations revealed convergent findings supporting a beneficial effect of ATO, with reduced right ventricular systolic pressure and medial wall thickness, and a significant decrease in the number of muscularized distal pulmonary arteries in ATO-treated Fra2TG mice compared to untreated Fra2TG mice. Additionally, inflammatory cell infiltration was also markedly reduced in lesioned lungs. A reduction in the frequency of CD4 + and T effector memory cells, and an increase in the percentage of CD4 + T naive cells in the lungs of ATO-treated Fra-2TG mice, was observed when compared to PBS group Fra-2Tg mice. RNA-seq analysis of ATO-treated mouse lungs revealed a downregulation of biological pathways associated with immune activity and inflammation, such as T-cell activation, regulation of leucocyte activation, leucocyte cell–cell adhesion, and regulation of lymphocyte activation.ConclusionsOur results suggest the clinical relevance of ATO treatment in SSc. Using the Fra2TG mouse model, we observed significant lung histological changes, a trend towards a decrease in various fibrotic makers, and a strong reduction in vascular remodeling. The mechanism of action of ATO appears to involve a marked counteraction of the immune activation characteristic of SSc, particularly T-cell involvement. These findings pave the way for further studies in SSc.

Rituximab in the treatment of systemic sclerosis. Literature review

Systemic sclerosis (SSc) is one of the most severe systemic rheumatic diseases, characterized by the development of progressive skin fibrosis and damage to internal organs, accompanied by a decrease in the quality of life and high mortality. The treatment of SSc remains a difficult clinical task due to the complex pathogenesis. Nowadays therapy is complex and based on the dominant clinical and pathogenetic phenotype of SSc. However, standard therapy have limited potential to radically improve the prognosis of SSc, and often their use can lead to the development of intolerance and adverse events. In this connection, it remains relevant to study and introduce new approaches for the treatment of SSc, one of which is anti-B-cell therapy. Based on the data on the key role of B cells in the regulation of inflammatory and fibrotic processes in SSc, rituximab (chimeric monoclonal antibody to B-lymphocyte surface receptors – CD20) is increasingly being studied and used in clinical practice for the treatment of this disease. This review collects and analyzes data on the efficacy, safety and impact of rituximab on various manifestations of SSc.

The use of “Acellbia” – a biosimilar of rituximab in systemic sclerosis

Introduction. The possibilities of modern therapy for systemic sclerosis (SSc) remains limited, since most of the used drugs do not have a diseasemodifying effect. This encourages the study of new approaches that potentially affect the fundamental pathological processes underlying the disease. One example is anti-B cell therapy, in particular rituximab (RTX). Until now RTX do not have a registration for the treatment of SSc, but there is a large positive experience of its use, which is reflected in recent meta-analyses and clinical recommendations. Complicated and expensive methods for obtaining genetically engineered biological preparations have contributed to the emergence of more accessible biosimilars, one of which is the RTX biosimilar, Acellbia (Biocad, Russian Federation). The “biosimilar” versions of RTX might reduce the cost of therapy and increase patients accessibility to this treatment option. The RTX biosimilar Acellbia (ACB) has received approval in Russian Federation in 2014 for all indications held by reference RTX (including rheumatoid arthritis and ANCA-associated vasculitis).The aim of this study was to investigate the efficacy and safety of Acellbia in patients with systemic sclerosis.Material and methods. Our prospective uncontrolled study included 20 patients (14 women) aged 50±14 years, with a disease duration of 3.5±2.7 years. Indications for the prescribing of ACB were high disease activity and the presence of risk factors for progression. All patients had radiological signs of interstitial lung disease, 13 (65%) were positive for antibodies to topoisomerase 1. None of the patients had previously been treated with biological therapy. All patients received glucocorticoids in low doses and 15 (75%) patients were not on concomitant immunosuppressants during the study. ACB was administered in doses of 2 g (two doses of 1 g with a weekly interval) at inclusion of the study and after 6–8 months according to the same scheme, cumulative dose – 4 g. An assessment of basic measurements was obtained at baseline (Point 0), before the second course (after 7.2±1.7 mo, Point 1) and at the end of follow-up (13.4±1.6 mo, Point 2). The results are presented in the form of mean values and standard deviations.Results. There was a positive effect on the main manifestations of the disease, which accompanied by stable depletion of CD19+ B lymphocytes in the peripheral blood. At the intermediate assessment (between points 0–1), no significant changes were observed, with the exception of the skin score. At the end of the study, most of the parameters showed a significant improvement between points 0–2. The activity of the disease (EScSG-AI) decreased, and the skin score decreased from 12.8±11 to 6.2±5.6 (p=0.002). The forced vital capacity (% of predicted) increased from 89±18.2 to 98.26±16.13% (p=0.0002), and the diffusion capacity of the lungs (% of predicted) increased from 56.8±15.7 to 61.9±17.2% (p&lt;0.019). A significant decrease in CRP, antitopoisomerase-1 antibodies, as well as IgG (from 12.6±2.6 to 10.2±2.2 g/l) was noted. Repopulation to normal level of B lymphocytes did not occur in any case, and complete depletion of B lymphocytes at the end of the study was maintained in 83% of patients (15 of 18). The quality of life questionnaire SHAQ improved (p=0.0001), and the average dose of prednisolone was reduced from 11.0±2.7 to 9.4±2.3 mg/day (p=0.03). Positive changes according to HRCT was evident in 9 (45%) patients due to a decrease in ground glass opacity. The frequency and spectrum of adverse events (AEs) corresponded to those already known for RTX. Of the 20 patients who received 2 courses of ACB, two withdrew from the evaluation at Point 2 due to pregnancy (1) and lung cancer (1). A total of 11 (55%) AEs were reported in 9 (45%) patients, most of them were classified as mild. Infectious complications developed in 7 (35%) patients: respiratory infections of the upper respiratory tract (4), positivity in the TB skin test (2), otitis (1), cystitis (1) and cholecystitis (1). One patient developed calf vein thrombosis and lung cancer was diagnosed in one case.Conclusion. Our data suggest that Acellbia could be used for the treatment of SSc. A short-term, prospective, uncontrolled study showed good efficacy and acceptable safety of the ACB biosimilar in SSc. A significant decrease of skin fibrosis and improvement of lung functions have been proven. The clinical effect of ACB manifested by the 6th month from the start of therapy and reached its maximum one year after its initiation. Due to the positive efficacy of ACB, it can be prescribed for the patients with SSc with ineffectiveness and/or intolerance to immunosuppressants, and could be considered as a first-line therapy. Our data should be confirmed by the results of controlled clinical trials.

Emerging cellular and immunotherapies for systemic sclerosis: from mesenchymal stromal cells to CAR-T cells and vaccine-based approaches.

Although two targeted therapies have received recent approval for systemic sclerosis (SSc)-associated interstitial lung disease, they do not show major disease-modifying activity, highlighting the need for novel therapies and innovative paradigms. To that end, cellular therapies may represent a new opportunity for the treatment of SSc. The purpose of this review is to provide an up-to-date overview of emerging cell-based disease-modifying therapies in SSc. Initial small studies in patients with severe refractory systemic lupus erythematosus (SLE) using engineered regulatory cells show promising results. CD19-directed CAR-T have shown promising results in one case report of refractory diffuse cutaneous SSc patients. T cells engineered to express a chimeric autoantibody receptor (CAAR-T cells) may be even more relevant via the specific elimination of auto-reactive B cells. Targeting pro-fibrotic or senescence-related pathways may also constitute promising approaches in SSc. Building on the classification of the clinical phenotype and prediction of clinical trajectory based on individual patients' autoantigen and/or autoantibody profile, cellular therapies targeting the same autoantigen or related autoreactive cells may represent an unprecedented opportunity to implement personalized medicine in SSc.

Treatable Traits in Systemic Sclerosis.

Systemic sclerosis (SSc) is a chronic systemic disease within the spectrum of connective tissue diseases, specifically characterized by vascular abnormalities and inflammatory and fibrotic involvement of the skin and internal organs resulting in high morbidity and mortality. The clinical phenotype of SSc is heterogeneous, and serum autoantibodies together with the extent of skin involvement have a predictive value in the risk stratification. Current recommendations include an organ-based management according to the predominant involvement with only limited individual factors included in the treatment algorithm. Similar to what has been proposed for other chronic diseases, we hypothesize that a "treatable trait" approach based on relevant phenotypes and endotypes could address the unmet needs in SSc stratification and treatment to maximize the outcomes. We provide herein a comprehensive review and a critical discussion of the literature regarding potential treatable traits in SSc, focusing on established and candidate biomarkers, with the purpose of setting the bases for a precision medicine-based approach. The discussion, structured based on the organ involvement, allows to conjugate the pathogenetic mechanisms of tissue injury with the proposed predictors, particularly autoantibodies and other serum biomarkers. Ultimately, we are convinced that precision medicine is the ideal guide to manage a complex condition such as SSc for which available treatments are largely unsatisfactory.

Animal models in systemic sclerosis: an update.

Systemic sclerosis (SSc) is a multisystem autoimmune connective tissue disease characterized by early inflammation followed by excessive fibrosis in the skin and internal organs. Enhancing our comprehension of SSc pathogenesis is essential to develop effective therapeutic strategies. Animal models that mimic one or more aspects of SSc have been proven to be a valuable resource for investigating disease mechanisms. This review aims to provide an updated overview of the existing SSc animal models and the potentially relevant pathways to SSc pathogenesis. This review focuses on the most recently generated and investigated animal models, which delve into novel pathways beyond existing models or employ genetic technologies to gain a deeper understanding of SSc pathogenesis including activation of early type I interferon (IFN) signaling pathway, immune cell function and pulmonary artery hypertension (PAH). While no single animal model can fully replicate SSc, a combination of different models can offer valuable insights into the pathways involved in the onset and advancement of the SSc. These insights can prove animal models as a crutial preclinical tool for developing effective treatments for SSc.

A randomized clinical trial of bermekimab treatment for clinical improvement of systemic sclerosis

Increased concentrations of interleukin (IL)-1α have been recently described in tissues of patients with systemic sclerosis (SSc) suggesting that IL-1α inhibition may be a target for treatment. We conducted a double-blind, placebo-controlled study to assess the safety and efficacy of the fully humanized IL-1α blocking monoclonal antibody bermekimab in SSc. To evaluate response to treatment, we developed the score of inhibition of progression of SSc which was validated using the CRISS index and the modified CRISS index. The primary endpoint was met in 80% of bermekimab-treated patients vs. 20% of placebo-treated patients (p: 0.023). Most of efficacy was found for increase of carbon monoxide lung diffusion capacity. Production of IL-1α and TNF by circulating mononuclear cells was decreased and the absolute count of CD42/Cd62-platelets was decreased. Results suggest that bermekimab is a promising treatment for SSc.

ATRA ameliorates fibrosis by suppressing the pro-fibrotic molecule Fra2/AP-1 in systemic sclerosis.

Systemic sclerosis (SSc) is an autoimmune connective tissue disease that leads to irreversible fibrosis of the skin and the internal organs. The etiology of SSc is complex, its pathophysiology is poorly understood, and clinical therapeutic options are restricted. Thus, research into medications and targets for treating fibrosis is essential and urgent. Fos-related antigen 2 (Fra2) is a transcription factor that is a member of the activator protein-1 family. Fra2 transgenic mice were shown to have spontaneous fibrosis. All-trans retinoic acid (ATRA) is a vitamin A intermediate metabolite and ligand for the retinoic acid receptor (RAR), which possesses anti-inflammatory and anti-proliferative properties. Recent research has demonstrated that ATRA also has an anti-fibrotic effect. However, the exact mechanism is not fully understood. Interestingly, we identified potential binding sites for the transcription factor RARα to the promoter region of the FRA2 gene through JASPAR and PROMO databases. In this study, the pro-fibrotic effect of Fra2 in SSc is confirmed. SSc dermal fibroblasts and bleomycin-induced fibrotic tissues of SSc animals exhibit increased levels of Fra2. Inhibition of Fra2 expression in SSc dermal fibroblasts with Fra2 siRNA markedly decreased collagen I expression. ATRA reduced the expressions of Fra2, collagen I, and α-smooth muscle actin(α-SMA) in SSc dermal fibroblasts and bleomycin-induced fibrotic tissues of SSc mice. In addition, chromatin immunoprecipitation and dual-luciferase assays demonstrated that retinoic acid receptor RARα binds to the FRA2 promoter and modulates its transcriptional activity. ATRA decreases collagen I expression both in vivo and in vitro via the reduction of Fra2 expression. This work establishes the rationale for expanding the use of ATRA in the treatment of SSc and indicates that Fra2 can be used as an anti-fibrotic target.

The Role of CCL24 in Systemic Sclerosis.

Systemic sclerosis (SSc) is a chronic immune-mediated disease characterized by microangiopathy, immune dysregulation, and progressive fibrosis of the skin and internal organs. Though not fully understood, the pathogenesis of SSc is dominated by microvascular injury, endothelial dysregulation, and immune response that are thought to be associated with fibroblast activation and related fibrogenesis. Among the main clinical subsets, diffuse SSc (dSSc) is a progressive form with rapid and disseminated skin thickening accompanied by internal organ fibrosis and dysfunction. Despite recent advances and multiple randomized clinical trials in early dSSc patients, an effective disease-modifying treatment for progressive skin fibrosis is still missing, and there is a crucial need to identify new targets for therapeutic intervention. Eotaxin-2 (CCL24) is a chemokine secreted by immune cells and epithelial cells, which promotes trafficking of immune cells and activation of pro-fibrotic cells through CCR3 receptor binding. Higher levels of CCL24 and CCR3 were found in the skin and sera of patients with SSc compared with healthy controls; elevated levels of CCL24 and CCR3 were associated with fibrosis and predictive of greater lung function deterioration. Growing evidence supports the potency of a CCL24-blocking antibody as an anti-inflammatory and anti-fibrotic modulating agent in multiple preclinical models that involve liver, skin, and lung inflammation and fibrosis. This review highlights the role of CCL24 in orchestrating immune, vascular, and fibrotic pathways, and the potential of CCL24 inhibition as a novel treatment for SSc.

Pharmacological inhibition of TAK1 prevents and induces regression of experimental organ fibrosis.

Multi-organ fibrosis in systemic sclerosis (SSc) accounts for substantial mortality and lacks effective therapies. Lying at the crossroad of transforming growth factor-β (TGF-β) and toll-like receptor (TLR) signaling, TGF-β-activated kinase 1 (TAK1) might have a pathogenic role in SSc. We therefore sought to evaluate the TAK1 signaling axis in patients with SSc, and investigate pharmacological TAK1 blockade using a novel drug-like selective TAK1 inhibitor, HS-276. Inhibiting TAK1 abrogated TGF-β1 stimulation of collagen synthesis and myofibroblasts differentiation in healthy skin fibroblasts, and ameliorated constitutive activation of SSc skin fibroblasts. Moreover, treatment with HS-276 prevented dermal and pulmonary fibrosis and reduced the expression of profibrotic mediators in bleomycin-treated mice. Importantly, initiating HS-276 treatment even after fibrosis was already established prevented its progression in affected organs. Together, these findings implicate TAK1 in the pathogenesis of SSc, and identify targeted TAK1 inhibition using a small molecule as a potential strategy for the treatment of SSc and other fibrotic diseases.

Systemic sclerosis associated myopathy: how to treat.

Systemic sclerosis (SSc) and myositis are two different entities that may coexist as an overlap syndrome. Immunological biomarkers such as anti-PM/Scl or anti-Ku reinforce the syndrome. This review is focused on the treatment of different and characteristic manifestations of this syndrome. Among the different phenotypes of muscle involvement in patients with SSc, the fibrotic pattern and the sporadic inclusion body myositis must be identified early to avoid a futile immunosuppressive treatment. Other forms such as dermatomyositis, non-specific myositis and immune-mediated necrotizing myopathy need to receive conventional immunosuppressive therapy considering that high dose of glucocorticoids may induce a scleroderma renal crisis in patients with SSc. Physicians must be aware of the existence of a "double trouble" association of hereditary myopathy with an autoimmune phenomenon. Several autoantibodies, mainly anti-PM/Scl and anti-Ku may help to define specific phenotypes with characteristic clinical manifestations that need a more specific therapy. Vasculopathy is one of the underlying mechanisms that link SSc and myositis. Recent advances in this topic are reviewed. Current treatment of SSc associated myopathy must be tailored to specific organs involved. Identifying the specific clinical, pathological, and immunological phenotypes may help to take the correct therapeutic decisions.

Comprehensive analysis of ferroptosis-related hub gene signatures as a potential pathogenesis and therapeutic target for systemic sclerosis: A bioinformatics analysis.

Introduction: The molecular mechanism of systemic sclerosis (SSc) remains unclear. Ferroptosis participates in a series of cell activities, such as inflammatory progression, by regulating cell death; unfortunately, there aren't many research that discuss the connection between ferroptosis and SSc.Objectives: This study used bioinformatics analysis to report a potential relationship between ferroptosis and SSc.Methods: The SSc and control datasets GSE125362 and GSE76807 were obtained from the gene expression omnibus database. The differentially expressed genes (DEGs) were identified using the R software. By the Venn diagram, ferroptosis DEGs were detected. The chosen candidate genes were then subjected to analyses of protein-protein interactions, gene ontology enrichment, and Kyoto Encyclopedia of Genes and Genomes pathway enrichment. With the Molecular Complex Detection plugin program, the hub genes were investigated. A multifactor regulatory network was constructed depending on key hub genes, and immune infiltration was also evaluated. Finally, quantitative real-time polymerase chain reaction (RT-PCR) and enzyme linked immunosorbent assay were used to validate the bioinformatic results.Results: Twenty-four ferroptosis-related differentially expressed genes were detected in patients with SSc versus the normal controls. The biological processes of FRGs in patients with SSc focused on the negative regulation of cell proliferation and inflammatory response. The signaling pathways were enriched in necroptosis. The core genes of SSc were CYBB, IL-6, NOX4,TLR4, CXCL2, JUN, and LY96. Three miRNAs, two lncRNAs, and five transcription factors were predicted. The evaluation of immune infiltration showed that the number of activated natural killer (NK) cells increased in SSc skin tissues, whereas the number of resting dendritic, NK, and mast cells decreased. The bioinformatics prediction results from the mRNA chip were in line with the expression levels of IL-6 and CYBB.Conclusions: Necroptosis and ferroptosis were upregulated in patients with SSc and involved in modulating cell proliferation, differentiation, and migration. IL-6 and CYBB are key ferroptosis-related genes in SSc. Ferroptosis and related genes might be promising targets in the treatment of SSc.