Fibrosis In Systemic Sclerosis Research Articles

Anti-fibrotic effect of a selective estrogen receptor modulator in systemic sclerosis

BackgroundThe rarity of systemic sclerosis (SSc) has hampered the development of therapies for this intractable autoimmune disease. Induced pluripotent stem cell (iPSC) can be differentiated into the key disease-affected cells in vitro. The generation of patient-derived iPSCs has opened up possibilities for rare disease modeling. Since these cells can recapitulate the disease phenotypes of the cell in question, they are useful high-throughput platforms for screening for drugs that can reverse these abnormal phenotypes.MethodsSSc iPSC was generated from PBMC by Sendai virus. Human iPSC lines from SSc patients were differentiated into dermal fibroblasts and keratinocytes. The iPSC-derived differentiated cells from the SSc patients were used on high-throughput platforms to screen for FDA-approved drugs that could be effective treatments for SSc.ResultsSkin organoids were generated from these cells exhibited fibrosis that resembled SSc skin. Screening of the 770-FDA-approved drug library showed that the anti-osteoporotic drug raloxifene reduced SSc iPSC-derived fibroblast proliferation and extracellular matrix production and skin fibrosis in organoids and bleomycin-induced SSc-model mice.ConclusionsThis study reveals that a disease model of systemic sclerosis generated using iPSCs-derived skin organoid is a novel tool for in vitro and in vivo dermatologic research. Since raloxifene and bazedoxifene are well-tolerated anti-osteoporotic drugs, our findings suggest that selective estrogen receptor modulator (SERM)-class drugs could treat SSc fibrosis.

Late skin fibrosis in systemic sclerosis: a study from the EUSTAR cohort.

The early trajectory of skin fibrosis provides insights into the disease course of systemic sclerosis (SSc) including mortality; however, little is known about late skin fibrosis. The aims of our study were to ascertain the prevalence and characteristics of late skin fibrosis in SSc. We developed and tested three conceptual scenarios of late (>5 years after first non-RP feature) skin fibrosis including new worsening of skin disease, and failure to improve after worsening within 5-year window. We defined skin worsening as change in modified Rodnan skin score (mRSS) ≥5 units or ≥25%. Using strict inclusion criteria including complete mRSS, we identified 1,043 (out of 19 115) patients within the EUSTAR database for our analysis. We further restricted analysis within 887 (out of 1043) patients who had lcSSc or dcSSc at baseline. One-fifth of patients among the whole cohort (n = 208/1043, 19.9%) experienced mRSS worsening, including in patients with lcSSc or dcSSc at baseline (n = 193/887, 21.8%). This was largely due to new skin worsening after the 5-year window or failure to improve with worsening within the 5-year window. Patients with lower baseline mRSS and lcSSc were more likely to develop late skin fibrosis. Anti-Scl-70 was associated with progression from baseline lcSSc to dcSSc, and anticentromere was protective. Late skin fibrosis is not uncommon in SSc. We have identified different patterns relevant to clinical practice and trial design. Late skin fibrosis is a neglected manifestation of SSc and warrants further investigation including to determine clinical outcomes and optimal therapeutic strategy.

Elevated Alpha 1(I) to Alpha 2(I) Collagen Ratio in Dermal Fibroblasts Possibly Contributes to Fibrosis in Systemic Sclerosis.

Systemic sclerosis (SSc) is characterized by excessive collagen deposition in the skin and internal organs. Activated fibroblasts are the key effector cells for the overproduction of type I collagen, which comprises the α1(I) and α2(I) chains encoded by COL1A1 and COL1A2, respectively. In this study, we examined the expression patterns of α1(I) and α2(I) collagen in SSc fibroblasts, as well as their co-regulation with each other. The relative expression ratio of COL1A1 to COL1A2 in SSc fibroblasts was significantly higher than that in control fibroblasts. The same result was observed for type I collagen protein levels, indicating that α2(I) collagen is more elevated than α2(I) collagen. Inhibition or overexpression of α1(I) collagen in control fibroblasts affected the α2(I) collagen levels, suggesting that α1(I) collagen might act as an upstream regulator of α2(I) collagen. The local injection of COL1A1 small interfering RNA in a bleomycin-induced SSc mouse model was found to attenuate skin fibrosis. Overall, our data indicate that α2(I) collagen is a potent regulator of type I collagen in SSc; further investigations of the overall regulatory mechanisms of type I collagen may help understand the aberrant collagen metabolism in SSc.

Ligation of TLR Homologue CD180 of B Cells Activates the PI3K/Akt/mTOR Pathway in Systemic Sclerosis and Induces a Pathological Shift in the Expression of BAFF Receptors.

The phosphatidylinositol-3-kinase (PI3K)/Akt and the mammalian target of rapamycin (mTOR) pathways are known to play a key role in B-cell activation and fibrosis in systemic sclerosis (SSc). Receptors of B-cell activator factor (BAFF) utilize these pathways, which can be influenced by Toll-like receptors (TLRs), as TLRs can alter the expression of BAFF-binding receptors. Our results show that B-cell stimulation via TLR homologue CD180 phosphorylates Akt in diffuse cutaneous SSc (dcSSc) to a lower extent than in healthy controls (HCs). We found basal downregulated BAFF receptor (BAFF-R) and enhanced transmembrane activator and calcium-modulator and cyclophilin ligand interactor (TACI) expression in dcSSc B cells, which might enhance the formation of autoantibody-secreting plasma cells. Moreover, this pathological shift was observed in naive B cells, emphasizing the importance of their increase in SSc. Additionally, we measured higher serum levels of autoantibodies to BAFF in dcSSc patients, suggesting that an imbalance in the complex system of BAFF/anti-BAFF autoantibodies/BAFF-binding receptors may contribute to the development of SSc. Anti-CD180 antibody treatment had opposite effects on the expression of BAFF-R and TACI in HC B cells, resulting in similar levels as observed in SSc B cells without stimulation, which argues against the usefulness of such therapy in SSc.

Molecular pathogenesis of fibrosis in systemic sclerosis

The principal cause of fibrosis in systemic sclerosis is thought to be excessive deposition of extracellular matrix in multiple organs. The main component of matrix is thought to be collagen, especially type I collagen, which is one of the most abundant proteins in the mammalian body. Various factors have been estimated to be involved in the mechanism of their excessive deposition in fibrotic tissues of systemic sclerosis. In this review, we discuss the latest findings on these factors.

MicroRNA-27a-3p inhibits lung and skin fibrosis of systemic sclerosis by negatively regulating SPP1

ObjectiveTo investigate the role and mechanism of microRNAs (miRNAs) in fibrotic processes involved in the pathology of systemic sclerosis (SSc). MethodsR language and bioinformatics methods were used to identify differential miRNAs and mRNAs and analyze their biological functions. Transfection experiments were performed to evaluate the function and regulatory mechanism of miR-27a-3p in vitro. Levels of fibrosis-related genes, SPP1 and cell proliferation were assessed. ResultsMiR-27a-3p is reduced both in SSc lung and skin tissues. Overexpression of miR-27a-3p significantly inhibited fibrosis-related genes expression and protein abundance and cell proliferation, whereas inhibition of miR-27a-3p significantly enhanced these phenomena. Moreover, miR-27a-3p exerts its anti-fibrosis effect by negatively regulating SPP1 and ERK signal, more prominent in fibroblasts. ConclusionsOur findings show that miR-27a-3p regulates a common mechanism in the process of SSc skin and lung fibrosis. MiR-27a-3p/SPP1/ERK1/2 axis may be an important target for delaying the progression of SSc fibrosis.

POS0914 LATE SKIN FIBROSIS IN SYSTEMIC SCLEROSIS: A STUDY FROM THE EUSTAR COHORT

BackgroundSkin fibrosis is a cardinal feature of systemic sclerosis (SSc) and associated with significant disability. The early trajectory of skin fibrosis provides insights into the course of the disease including mortality; however, little is known about late skin fibrosis in SSc.ObjectivesThe aims of our study were to ascertain the prevalence and characteristics of late skin fibrosis in SSc.MethodsWe developed and tested three conceptual scenarios of late (>5 years after 1st non-RP sign or symptom) skin fibrosis (Figure 1):Figure 1.Conceptual models/scenarios of late skin fibrosis in SSc. A: worsening and then improvement (>3 mRSS) during the first 5 years, and then worsened again after 5 years. B: worsening for the first time after 5 years. C: worsening in the first 5 years and stayed high after 5 years (i.e., failure to improve).A. Worsening and then improvement (>3 mRSS) during the first 5 years, and then worsened again after 5 years.B. Worsening for the first time after 5 years.C. Worsening in the first 5 years and stayed high after 5 years (i.e., failure to improve).We defined skin worsening as modified Rodnan skin score (mRSS) ≥ 5 units or ≥ 25%. Using strict inclusion criteria including complete mRSS, we identified 1,043 (out of 19,115) patients within the EUSTAR database for our analysis. We further restricted analysis within 887 (out of 1,043) patients who had limited (lcSSc) or diffuse cutaneous SSc (dcSSc) at baseline.ResultsOne-fifth of patients among the whole cohort (n=208/1043, 19.9%) including in patients with lcSSc or dcSSc at baseline (n=193/887, 21.8%) developed late skin fibrosis. This was largely due to new skin worsening or failure to improve. Patients with lower baseline mRSS and lcSSc were more likely to develop late skin fibrosis. Anti-Scl-70 antibodies (Table 1) were associated with progression from baseline lcSSc to dcSSc, and anticentromere antibodies were protective.Table 1.Impact of autoantibody status on progression from baseline limited to diffuse cutaneous SSc (dcSSc).Skin worsening after 5 years (Scenario B) (n=70)Skin worsening within 5 years and failed to improve after 5-year window (Scenario C) (n=61)Progressed to dcSSc (n=23)Not progressed to dcSSc(n=47)P-valueProgressed to dcSSc (n=37)Not progressed to dcSSc(n=24)P-valueAnticentromere+ve2/22 (9.1%)19/42 (45.2%)0.00346/34 (17.6%)14/21 (66.7%)0.0002-ve20/22 (90.9%)23/42 (54.8%)28/34 (82.4%)7/21 (33.3%)Anti-Scl-70+ve15/23 (65.2%)14/44 (31.8%)0.008822/36 (61.1%)8/23 (34.8%)0.0485-ve8/23 (34.8%)30/44 (68.2%)14/36 (38.9%)15/23 (65.2%)Anti-RNA-Polymerase-III+ve0/12 (0.0%)1/22 (4.5%)1.00000/6 (0.0%)0/14 (0.0%)---ve12/12 (100%)21/22 (95.5%)6/6 (100%)14/14 (100%)ConclusionLate skin fibrosis affects approximately 20% of SSc patients >5 years after onset of disease. We have identified different patterns relevant to clinical practice and trial design. Late skin fibrosis is usually due to new worsening or failure of skin to improve. Progression from baseline limited to diffuse cutaneous SSc was associated with anti-Scl-70 antibodies, and anticentromere antibodies were protective. Late skin fibrosis is a neglected manifestation of SSc and warrants further investigation including to determine clinical outcomes and optimal therapeutic strategy.AcknowledgementsOn behalf of EUSTAR collaborators.Disclosure of InterestsMichael Hughes Speakers bureau: Speaking fees from Actelion pharmaceuticals, Eli Lilly, and Pfizer, outside of the submitted work, Suiyuan Huang: None declared, Juan Jose Alegre Sancho Speakers bureau: Speaking and/or investigational fees from Actelion pharmaceuticals, Eli Lilly, Pfizer, Boehringer Ingelheim, Roche, and GSK, outside of the submitted work, Grant/research support from: Speaking and/or investigational fees from Actelion pharmaceuticals, Eli Lilly, Pfizer, Boehringer Ingelheim, Roche, and GSK, outside of the submitted work, Patricia Carreira: None declared, Merete Engelhart: None declared, Eric Hachulla Speakers bureau: Received consulting fees/meeting fees from Johnson & Johnson, Boehringer Ingelheim, Bayer, GSK, Roche-Chugai, Sanofi-Genzyme; speaking fees from Johnson & Johnson, GSK, Roche-Chugai; and research funding from CSL Behring, GSK, Roche-Chugai and Johnson & Johnson., Consultant of: Received consulting fees/meeting fees from Johnson & Johnson, Boehringer Ingelheim, Bayer, GSK, Roche-Chugai, Sanofi-Genzyme; speaking fees from Johnson & Johnson, GSK, Roche-Chugai; and research funding from CSL Behring, GSK, Roche-Chugai and Johnson & Johnson., Jörg Henes Speakers bureau: Lectures for CHUGAI, Boehringer-Ingelheim, Eduardo Kerzberg: None declared, Maria Rosa Pozzi: None declared, Gabriela Riemekasten: None declared, Vanessa Smith: None declared, Gabriella Szucs: None declared, Marie Vanthuyne: None declared, Elisabetta Zanatta: None declared, Oliver Distler: None declared, Armando Gabrielli: None declared, Anna-Maria Hoffmann-Vold: None declared, Viginia Steen: None declared, Dinesh Khanna Shareholder of: DK has stock options in Eicos Sciences, Inc., Consultant of: Consultant for Acceleron, Amgen, Boehringer Ingelheim, CSL Behring, Chemomab, Genentech/Roche, Horizon, Mitsubishi Tanabe Pharma, Prometheus, Talaris., Grant/research support from: Has received grants from Bayer, BMS, Horizon and Pfizer (to University of Michigan).

Interleukin-1β-Activated Microvascular Endothelial Cells Promote DC-SIGN-Positive Alternatively Activated Macrophages as a Mechanism of Skin Fibrosis in Systemic Sclerosis.

To characterize the role of interleukin-1β (IL-1β) and microvascular endothelial cells (MVECs) in the generation of alternatively activated macrophages in the skin, and to explore their role in the development of skin fibrosis in patients with systemic sclerosis (SSc; scleroderma). Conditioned medium prepared with MVECs purified from the skin of healthy donors and the skin of SSc patients was used to generate monocyte-derived macrophages. Flow cytometry, multiplex protein assessment, real-time quantitative polymerase chain reaction, and tissue immunofluorescence were used to characterize MVEC-induced polarization of alternatively activated macrophages. Coculture experiments were conducted to assess the role of MVEC-induced alternatively activated macrophages in fibroblast activation. Alternatively activated macrophages were characterized in the skin of healthy donors and SSc patients using multiparametric immunofluorescence and multiplex immunostaining for gene expression. Based on our in vitro data, we defined a supervised macrophage gene signature score to assess correlation between the macrophage score and clinical features in patients with SSc, using the Spearman's test. IL-1β-activated MVECs from SSc patients induced monocytes to differentiate into DC-SIGN+ alternatively activated macrophages producing high levels of CCL18, CCL2, and CXCL8 but low levels of IL-10. DC-SIGN+ alternatively activated macrophages showed significant enhancing effects in promoting the production of proinflammatory fibroblasts and were found to be enriched in perivascular regions of the skin of SSc patients who had a high fibrosis severity score. A novel skin transcriptomic macrophage signature, defined from our in vitro findings, correlated with the extent of skin fibrosis (Spearman's r = 0.6, P = 0.0018) and was associated with early disease manifestations and lung involvement in patients with SSc. Our findings shed new light on the vicious circle implicating unabated IL-1β secretion, MVEC activation, and the generation of DC-SIGN+ alternatively activated macrophages in the development of skin fibrosis in patients with SSc.

Autologous hematopoietic stem cell transplantation promotes connective tissue remodeling in systemic sclerosis patients

BackgroundAutologous hematopoietic stem cell transplantation (AHSCT) treats patients with severe and progressive systemic sclerosis (SSc). However, basic mechanisms associated with the therapeutic efficacy of the procedure are not entirely understood. We aimed to evaluate how AHSCT affects skin fibrosis in SSc patients.MethodsClinical data, serum, and skin samples from 39 SSc patients who underwent AHSCT were retrospectively evaluated. Skin biopsies were analyzed by immunohistochemistry with anti-MMP-1, -MMP-2, -MMP-3, -MMP-9, -TIMP-1, -α-SMA, -TGF-β, and -NF-κB p65 antibodies, and stained with hematoxylin and eosin and picrosirius red to assess skin thickness and collagen density, respectively. Serum samples were evaluated by Multiplex Assay for COL1A1, COL4A1, FGF-1, MMP-1, MMP-3, MMP-12, MMP-13, PDGF-AA, PDGF-BB, S100A9, and TIMP-1 levels and compared to healthy controls.ResultsAfter AHSCT, SSc patients showed clinical improvement in skin involvement, assessed by modified Rodnan’s skin score (mRSS). Histologically, collagen density and skin thickness decreased after AHSCT. Immunohistochemical analyses showed increased expression of MMP-2, MMP-3, MMP-9, and TIMP-1 after AHSCT, whereas expression of NF-κB p65 decreased. At baseline, serum levels of COL4A1 and S100A9 were higher than in healthy controls. Serum levels of S100A9 normalized after AHCST in SSc patients compared to controls. Serum levels of PDGF-AA, PDGF-BB, TIMP-1, and MMP-1 decreased, while COL1A1 increased after AHSCT in SSc patients. No changes were detected in MMP-3, MMP-12, MMP-13, and FGF-1 serum levels after AHSCT.ConclusionsOur results suggest that the therapeutic effects of AHSCT on skin fibrosis are related to changes in molecules associated with connective tissue maintenance and inflammation in SSc.

Oxidative stress promotes fibrosis in systemic sclerosis through stabilization of a kinase-phosphatase complex.

Systemic sclerosis (SSc) is a fibrotic autoimmune disease characterized by pathogenic activation of fibroblasts enhanced by local oxidative stress. The tyrosine phosphatase PTP4A1 was identified as a critical promoter of TGF-β signaling in SSc. Oxidative stress is known to functionally inactivate tyrosine phosphatases. Here, we assessed whether oxidation of PTP4A1 modulates its profibrotic action and found that PTP4A1 forms a complex with the kinase SRC in scleroderma fibroblasts, but surprisingly, oxidative stress enhanced rather than reduced PTP4A1’s association with SRC and its profibrotic action. Through structural assessment of the oxo-PTP4A1-SRC complex, we unraveled an unexpected mechanism whereby oxidation of a tyrosine phosphatase promotes its function through modification of its protein complex. Considering the importance of oxidative stress in the pathogenesis of SSc and fibrosis, our findings suggest routes for leveraging PTP4A1 oxidation as a potential strategy for developing antifibrotic agents.

PDGF/PDGFR: A Possible Molecular Target in Scleroderma Fibrosis.

Systemic sclerosis (SSc) is a clinically heterogeneous disorder of the connective tissue characterized by vascular alterations, immune/inflammatory manifestations, and organ fibrosis. SSc pathogenesis is complex and still poorly understood. Therefore, effective therapies are lacking and remain nonspecific and limited to disease symptoms. In the last few years, many molecular and cellular mediators of SSc fibrosis have been described, providing new potential options for targeted therapies. In this review: (i) we focused on the PDGF/PDGFR pathway as key signaling molecules in the development of tissue fibrosis; (ii) we highlighted the possible role of stimulatory anti-PDGFRα autoantibodies in the pathogenesis of SSc; (iii) we reported the most promising PDGF/PDGFR targeting therapies.

Janus kinase inhibitors for treatment of morphea and systemic sclerosis: A literature review.

Morphea and systemic sclerosis (SSc) are rare disorders of connective tissue characterized by increased skin thickness and fibrosis, with current treatment options having variable efficacies, many with limited therapeutic benefit. Janus kinase (JAK) inhibitors have been shown in preclinical studies to inhibit the fibrotic pathway in murine models of systemic sclerosis, by blocking TGF-beta mediated pathway of STAT protein activation. Additionally, case reports of the treatment of morphea and SSc with tofacitinib, a JAK 1/3 inhibitor, have shown improvement in skin sclerosis. Several JAK inhibitors have been developed and utilized in dermatologic and rheumatologic diseases. To date, tofacitinib has been by far the most commonly trialed JAK inhibitor in patients with SSc and morphea. Herein we review the preclinical studies reported in the literature supporting the use and efficacy of JAK inhibitors for the treatment of morphea and the cutaneous manifestations of SSc, as well as discuss the clinical cases published to date illustrating the benefits of JAK inhibitors in disease management. The pathogenesis and mechanism of action will be reviewed as it relates to the process of skin fibrosis in morphea and SSc, along with the murine models illustrating efficacy of JAK inhibitors in fibrotic disease. Based on available preclinical and clinical data as well as consideration of the mechanism of action of JAK inhibitors on the pathway for cutaneous fibrosis, there is promising evidence to support the use and further study of JAK inhibitors in the management of morphea and cutaneous fibrosis in SSc.

Microvasculopathy-Related Hemorrhagic Tissue Deposition of Iron May Contribute to Fibrosis in Systemic Sclerosis: Hypothesis-Generating Insights from the Literature and Preliminary Findings

Microvascular wall abnormalities demonstrated by nailfold capillaroscopy in systemic sclerosis (SSc) may result in microhemorrhagic deposition of erythrocyte-derived iron. Such abnormalities precede fibrosis, which is orchestrated by myofibroblasts. Iron induces endothelial-to-mesenchymal transition in vitro, which is reversed by reactive oxygen species (ROS) scavengers. The conversion of quiescent fibroblasts into profibrotic myofibroblasts has also been associated with ROS-mediated activation of TGF-β1. Given that iron overload predisposes to ROS formation, we hypothesized that the uptake of erythrocyte-derived iron by resident cells promotes fibrosis. Firstly, we show that iron induces oxidative stress in skin-derived and synovial fibroblasts in vitro, as well as in blood mononuclear cells ex vivo. The biological relevance of increased oxidative stress was confirmed by showing the concomitant induction of DNA damage in these cell types. Similar results were obtained in vivo, following intravenous iron administration. Secondly, using magnetic resonance imaging we show an increased iron deposition in the fingers of a patient with early SSc and nailfold microhemorrhages. While a systematic magnetic resonance study to examine tissue iron levels in SSc, including internal organs, is underway, herein we propose that iron may be a pathogenetic link between microvasculopathy and fibrosis and an additional mechanism responsible for increased oxidative stress in SSc.

PLG nanoparticles target fibroblasts and MARCO+ monocytes to reverse multiorgan fibrosis.

Systemic sclerosis (SSc) is a chronic, multisystem orphan disease with a highly variable clinical course, high mortality rate, and a poorly understood complex pathogenesis. We have identified an important role for a subpopulation of monocytes and macrophages characterized by surface expression of the scavenger receptor macrophage receptor with collagenous structure (MARCO) in chronic inflammation and fibrosis in SSc and in preclinical disease models. We show that MARCO+ monocytes and macrophages accumulate in lesional skin and lung in topographic proximity to activated myofibroblasts in patients with SSc and in the bleomycin-induced mouse model of SSc. Short-term treatment of mice with a potentially novel nanoparticle, poly(lactic-co-glycolic) acid (PLG), which is composed of a carboxylated, FDA-approved, biodegradable polymer and modulates activation and trafficking of MARCO+ inflammatory monocytes, markedly attenuated bleomycin-induced skin and lung inflammation and fibrosis. Mechanistically, in isolated cells in culture, PLG nanoparticles inhibited TGF-dependent fibrotic responses in vitro. Thus, MARCO+ monocytes are potent effector cells of skin and lung fibrosis and can be therapeutically targeted in SSc using PLG nanoparticles.

Esomeprazole alleviates fibrosis in systemic sclerosis by modulating AhR/Smad2/3 signaling

Systemic sclerosis (SSc) is a connective tissue disease with the involvement of complex signaling pathways, such as TGF-β/Smad2/3. SSc can lead to severe multiple organ fibrosis, but no effective therapy is currently available because of its unclear pathogenesis. Exploring new treatments is the focus of recent research on SSc. Recent studies have implied a potential antifibrotic role of esomeprazole (ESO), but with currently unidentified mechanisms. Signaling of AhR, a ligand-dependent transcription factor, has been described as a key controller of fibrosis, tumorigenesis, and immune balance. Recently, it has been reported that ESO may be an exogenous agonist of AhR signaling, while no previous study has revealed the effects of ESO on SSc and its underlying mechanisms. In this study, we demonstrate that ESO suppresses the migration of SSc dermal fibroblasts, downregulates profibrotic markers, including COLIA1, α-SMA CTGF and MMP1, and limits collagen production potentially via the activation of AhR signaling. More importantly, ESO could block Smad2/3 phosphorylation concurrently with the reduction in collagen via AhR signaling. Moreover, our results from the bleomycin (BLM)-induced SSc model in skin and lung shows that ESO ameliorates fibrosis in vivo, which in keeping with our in vitro results. We conclude that ESO is a potential therapeutic drug for SSc fibrosis.

Is Netrin-1 Associated With the Development of Fibrosis in Systemic Sclerosis?

Is Netrin-1 Associated With the Development of Fibrosis in Systemic Sclerosis?

M2 Macrophage Polarization in Systemic Sclerosis Fibrosis: Pathogenic Mechanisms and Therapeutic Effects

M2 Macrophage Polarization in Systemic Sclerosis Fibrosis: Pathogenic Mechanisms and Therapeutic Effects

Defective Early B Cell Tolerance Checkpoints in Patients With Systemic Sclerosis Allow the Production of Self Antigen-Specific Clones.

Early selection steps preventing autoreactive naive B cell production are often impaired in patients with autoimmune diseases, but central and peripheral B cell tolerance checkpoints have not been assessed in patients with systemic sclerosis (SSc). This study was undertaken to characterize early B cell tolerance checkpoints in patients with SSc. Using an in vitro polymerase chain reaction-based approach that allows the expression of recombinant antibodies cloned from single B cells, we tested the reactivity of antibodies expressed by 212 CD19+CD21low CD10+IgMhigh CD27- new emigrant/transitional B cells and 190 CD19+CD21+CD10-IgM+CD27- mature naive B cells from 10 patients with SSc. Compared to serum from healthy donors, serum from patients with SSc displayed elevated proportions of polyreactive and antinuclear-reactive new emigrant/transitional B cells that recognize topoisomerase I, suggesting that defective central B cell tolerance contributes to the production of serum autoantibodies characteristic of the disease. Frequencies of autoreactive mature naive B cells were also significantly increased in SSc patients compared to healthy donors, thus indicating that a peripheral B cell tolerance checkpoint may be impaired in SSc. Defective counterselection of developing autoreactive naive B cells in SSc leads to the production of self antigen-specific B cells that may secrete autoantibodies and allow the formation of immune complexes, which promote fibrosis in SSc.

The Contribution of LIGHT (TNFSF14) to the Development of Systemic Sclerosis by Modulating IL-6 and T Helper Type 1 Chemokine Expression in Dermal Fibroblasts

Systemic sclerosis (SSc) is an autoimmune and vascular disease resulting in multiple organ fibrosis, in which IL-6 and T helper (Th)2/Th17 cytokines serve as critical disease drivers. LIGHT is a proinflammatory cytokine promoting IL-6 production in lung fibroblasts and Th1 chemokine expression in dermal fibroblasts (DFs) stimulated with IFN-γ. In this study, we investigated the potential contribution of LIGHT to SSc development using clinical samples and animal models. In SSc-involved skin, LIGHT was upregulated in inflammatory cells, whereas herpesvirus entry mediator (HVEM), a receptor of LIGHT, was downregulated in DFs. Similar expression profiles of LIGHT and HVEM were reproduced in bleomycin-treated mice. Transcription factor FLI1 bound to the HVEM promoter, and FLI1 small interfering RNA suppressed HVEM expression in normal DFs. In SSc DFs, LIGHT significantly increased IL-6 production, whereas IFN-γ/LIGHT-dependent Th1 chemokine induction was decreased compared with that in normal DFs. Importantly, LIGHT small interfering RNA significantly attenuated bleomycin-induced skin fibrosis, and serum LIGHT levels were elevated in patients with diffuse cutaneous SSc and positively correlated with clinical parameters reflecting skin and pulmonary fibrosis. Taken together, these results suggest that altered response of DFs to LIGHT, namely increased IL-6 production and decreased Th1 chemokine expression, contributes to the development of skin fibrosis in SSc.

Expert opinion and patients’ in-depth interviews on the impact of pulmonary complications in systemic sclerosis

Objective To qualitatively explore the perceptions and opinions of experts dealing with systemic sclerosis (SSc) and patients with SSc on the impact of the disease and pulmonary complications on economic status, psycho-social wellbeing and the diagnostic and therapeutic journey, and to identify which strategies/interventions may be useful to address patients’ and their family’s needs. Methods An expert meeting was conducted using the NGT to discuss the consequences of pulmonary complications on the Italian SSc community. The direct experience of five patients with SSc and pulmonary complications was described through in-depth interviews conducted by psychologists. Results The experts’ meeting and patients’ in-depth interviews underline the complexity of SSc and the consequences of pulmonary involvement on patients’ and caregivers’ health-related quality of life, working ability, psychological wellbeing and social interactions. Panellists suggest that improved communication between physicians, associations and institutions could help protect the working status of patients with SSc. Granting patients disability benefits, providing access to part-time jobs and productivity-focused training could also help decrease the economic burden of the disease. A multidisciplinary approach is recommended to reduce treatment burden, together with the implementation of standard diagnostic and therapeutic paths and increased use of telemedicine via platforms that ensure secure health data sharing. Both patients and caregivers may benefit from psychological support. Conclusion SSc and pulmonary fibrosis have profound consequences on patients’ and caregivers’ health-related quality of life, working ability, psychological wellbeing and social interactions. Some activities may help patients and families deal with these aspects of the disease.