Fibrosis In Scleroderma Research Articles

186 Immune cell-derived growth factors drive fibrosis in scleroderma and graft-vs-host disease

Scleroderma (Systemic sclerosis) is an autoimmune disease that leads to excess production of collagen and other matrix proteins in the skin and other organs. Graft-vs-host disease, a major complication of stem cell transplant, can cause similar scarring of the skin. We hypothesized that scleroderma and the sclerotic form of graft-vs-host disease have overlapping immune-mediated pathogenesis. To examine pathways that drive fibrosis, we performed single-cell RNA sequencing from skin biopsies of patients with diffuse scleroderma and sclerotic graft-vs-host disease compared to normal controls.

Interleukin-31 promotes pathogenic mechanisms underlying skin and lung fibrosis in scleroderma.

Cytokines released by infiltrating T cells may promote mechanisms leading to fibrosis in scleroderma. The aim of this study was to investigate the role of the Th2 cytokine IL-31, and its receptor IL-31RA, in scleroderma skin and lung fibrosis. IL-31 was measured by ELISA of plasma, and by immunochemistry of fibrotic skin and lung tissue of scleroderma patients. The receptor, IL-31RA, was assayed by qPCR of tissue resident cells. Next-generation sequencing was used to profile the responses of normal skin fibroblasts to IL-31. In wild-type Balb/c mice, IL-31 was administered by subcutaneous mini pump, with or without additional TGFβ, and the fibrotic reaction measured by histology and ELISA of plasma. IL-31 was present at high levels in plasma and fibrotic skin and lung lesions in a subset of scleroderma patients, and the receptor overexpressed by downstream cells relevant to the disease process, including skin and lung fibroblasts, through loss of epigenetic regulation by miR326. In skin fibroblasts, IL-31 induced next generation sequencing profiles associated with cellular growth and proliferation, anaerobic metabolism and mineralization, and negatively associated with angiogenesis and vascular repair, as well as promoting phenotype changes including migration and collagen protein release via pSTAT3, resembling the activation state in the disease. In mice, IL-31 induced skin and lung fibrosis. No synergy was seen with TGFβ, which supressed IL-31RA. IL-31/IL-31RA is confirmed as a candidate pro-fibrotic pathway, which may contribute to skin and lung fibrosis in a subset of scleroderma patients.

P168 Modelling macrophage-fibroblast interaction in scleroderma to evaluate new treatments

Abstract Background Alternatively-activated M2-like macrophages are known to express CD206 and are thought to have an important role in pathological fibrosis in scleroderma through stimulation of fibroblasts. RP peptides are 10-12 mer synthetic peptides which have been developed to engage with human macrophages via CD206, but the selectivity of this receptor for macrophages requires clarification. In this study, we investigate the relative expression levels of CD206 in SSc macrophages and fibroblasts, and explore two approaches in modelling macrophage-fibroblast interactions to evaluate the efficacy of the RP peptides. Methods Macrophages were derived from peripheral blood mononuclear cells by culture of buffy layer cells in RPMI supplemented by M-CSF (4ng/ml) for 7 days. Skin fibroblasts were obtained by explant culture of 4 mm punch biospies from the involved forearm skin of SSc patients and healthy controls, maintained in DMEM with 10-% FCS and studied at passage 3-5. Stimulation with TGFβ (4ng/ml) was used to further enhance the activation state of fibroblasts. Macrophages and skin fibroblast lysates were evaluated using qPCR to determine the level of expression of CD206. Macrophages were co-cultured with fibroblasts within respective monolayers on 50kPa gels (models stiff scleroderma skin) for four days with or without the peptide inhibitors. Collagen mRNA expression from the cellular monolayers were quantified by qPCR and Western blot. In the second approach, macrophages and fibroblasts were co-cultured together with or without the peptide inhibitors in a collagen gel contraction assay. The gel was weighed and imaged after 48 hours of incubation and the collagen gel contraction was then quantified as a measure of fibrotic activity. Results Expression of CD206 was specific to macrophages and not seen in fibroblast cultures (relative expression level in macrophages 26.63 versus 0.004 in unstimulated fibroblasts versus 0.04 in TGFβ-stimulated fibroblasts. Fibroblasts co-cultured with macrophages in monolayers show increased CTGF and collagen mRNA by qPCR. There was a dose response reduction in CTGF and collagen mRNA in assays cultured with the RP peptide inhibitor. CTGF mRNA was positively correlated with CD206 expression (r2=0.81). Co-culture of SSc macrophages led to enhanced contraction of collagen gels (0.1g in macrophages, 0.08g in fibroblasts, 0.062 for fibroblasts co-cultured with macrophages) which was fully reversed by the RP peptide treatment (0.1g). Conclusion SSc macrophages express CD206 which has potential as a biomarker of ongoing fibrotic activity whereas fibroblasts express very minimal levels of CD206 even when stimulated by the pro-fibrotic TGFβ. RP peptides that are specific for CD206 on macrophages led to a suppression of the macrophage signature and inhibition of the pro-fibrotic cross talk in macrophages and fibroblasts in both monolayer and 3D collagen gels. Both approaches of evaluating macrophage-fibroblast interactions in scleroderma are viable approaches to evaluate new treatments. Disclosures L. Lei None. B. Abdi None. A. Mujkavnovic None. X. Shi Wen None. H. Lopez Shareholder/stock ownership; Scientific director at Riptide Biosciences. R. Stratton None.

Adipose‐derived stromal/stem cells successfully attenuate the fibrosis of scleroderma mouse models

Systemic sclerosis (SSc) is an autoimmune disease characterized by skin and lung fibrosis. Although SSc has a high mortality risk, an effective treatment for the disease has not been established yet. Mesenchymal stromal/stem cells (MSCs) are multipotential nonhematopoietic progenitor cells that have the ability to regulate immune responses. Adipose-derived stromal/stem cells (ASCs), one of the types of MSCs, have the advantage of accessibility and potent immunomodulatory effects when compared with other MSCs, such as bone marrow-derived MSCs. This study aimed to investigate the antifibrotic effect of ASCs in scleroderma mouse models, including bleomycin-induced scleroderma and sclerodermatous chronic graft-versus-host disease (Scl-cGVHD) models. ASCs were intravenously administered to a bleomycin-induced scleroderma or Scl-cGVHD model on day 0. We compared the skin and lung fibrosis of scleroderma model mice between the ASC-treated group and control group. Administration of ASCs attenuated the skin and lung fibrosis of bleomycin-induced scleroderma and Scl-cGVHD model mice compared to that in the control mice. Immunohistochemical staining showed that ASCs suppressed the infiltration of CD4+ , CD8+ T cells and macrophages into the dermis of bleomycin model mice compared to that in control mice. In addition, ASCs attenuated the messenger RNA expression of collagen and fibrogenic cytokines, such as interleukin (IL)-6 and IL-13, in the skin of bleomycin model mice. ASCs also reduced the frequency of fibrogenic cytokine-producing CD4+ T cells and effector B cells in the spleen of bleomycin model mice. ASCs could prove to be a potential therapeutic agent for use in patients with SSc.

Formyl Peptide Receptor 2 Activation Ameliorates Dermal Fibrosis and Inflammation in Bleomycin-Induced Scleroderma.

Systemic sclerosis is a profibrotic autoimmune disease mediated by the dysregulation of extracellular matrix synthesis. Formyl peptide receptor 2 (Fpr2) is a G protein-coupled receptor that modulates inflammation and host defense by regulating the activation of inflammatory cells, such as macrophages. However, the role of Fpr2 in the development and therapy of scleroderma is still unclear. The present study was conducted to investigate the effects of Fpr2 activation in the treatment of scleroderma fibrosis. We found that intradermal administration of WKYMVm, an Fpr2-specific agonist, alleviated bleomycin-induced scleroderma fibrosis in mice and decreased dermal thickness in scleroderma skin. WKYMVm-treated scleroderma skin tissues displayed reduced numbers of myofibroblasts expressing α-smooth muscle actin, Vimentin, and phosphorylated SMAD3. WKYMVm treatment attenuated macrophage infiltration in scleroderma skin and reduced the number of M2 macrophages. The therapeutic effects of WKYMVm in scleroderma-associated fibrosis and inflammation were completely abrogated in Fpr2 knockout mice. Moreover, WKYMVm treatment reduced the serum levels of inflammatory cytokines, such as tumor necrosis factor-α, and interferon-γ, in the scleroderma model of wild-type mice but not in Fpr2 knockout mice. These results suggest that WKYMVm-induced activation of Fpr2 leads to alleviation of fibrosis by stimulating immune resolution in systemic sclerosis.

700 Targeting SIRT/CD38/NAD+ homeostasis to mitigate fibrosis in scleroderma

700 Targeting SIRT/CD38/NAD+ homeostasis to mitigate fibrosis in scleroderma

230 Anti-fibrotic efficacy of phosphodiesterase-5 inhibitors on cutaneous fibrosis in scleroderma

230 Anti-fibrotic efficacy of phosphodiesterase-5 inhibitors on cutaneous fibrosis in scleroderma

Targeting of dermal myofibroblasts through death receptor 5 arrests fibrosis in mouse models of scleroderma

Scleroderma is an autoimmune rheumatic disorder accompanied by severe fibrosis in skin and other internal organs. During scleroderma progression, resident fibroblasts undergo activation and convert to α-smooth muscle actin (α-SMA) expressing myofibroblasts (MFBs) with increased capacity to synthesize collagens and fibrogenic components. Accordingly, MFBs are a major therapeutic target for fibrosis in scleroderma and treatment with blocking MFBs could produce anti-fibrotic effects. TLY012 is an engineered human TNF-related apoptosis-inducing ligand (TRAIL) which induces selective apoptosis in transformed cells expressing its cognate death receptors (DRs). Here we report that TLY012 selectively blocks activation of dermal fibroblasts and induces DR-mediated apoptosis in α-SMA+ MFBs through upregulated DR5 during its activation. In vivo, TLY012 reverses established skin fibrosis to near-normal skin architecture in mouse models of scleroderma. Thus, the TRAIL pathway plays a critical role in tissue remodeling and targeting upregulated DR5 in α-SMA+ MFBs is a viable therapy for fibrosis in scleroderma.

Adipose-derived mesenchymal stromal/stem cells in systemic sclerosis: Alterations in function and beneficial effect on lung fibrosis are regulated by caveolin-1.

The potential value of mesenchymal stromal/stem cell therapy in treating skin fibrosis in scleroderma (systemic sclerosis) and of the caveolin-1 scaffolding domain peptide in treating lung, skin, and heart fibrosis is known. To understand how these observations may relate to differences between mesenchymal stromal/stem cells from healthy subjects and subjects with fibrosis, we have characterized the fibrogenic and adipogenic potential of adipose-derived mesenchymal stromal/stem cells from systemic sclerosis patients, from mice with fibrotic lung and skin disease induced by systemic bleomycin treatment, and from healthy controls. Early passage systemic sclerosis adipose-derived mesenchymal stromal/stem cells have a profibrotic/anti-adipogenic phenotype compared to healthy adipose-derived mesenchymal stromal/stem cells (low caveolin-1, high α-smooth muscle actin, high HSP47, low pAKT, low capacity for adipogenic differentiation). This phenotype is mimicked by treating healthy adipose-derived mesenchymal stromal/stem cells with transforming growth factor beta or caveolin-1 small interfering RNA and is reversed in systemic sclerosis adipose-derived mesenchymal stromal/stem cells by treatment with caveolin-1 scaffolding domain peptide, but not scrambled caveolin-1 scaffolding domain peptide. Similar results were obtained with adipose-derived mesenchymal stromal/stem cells from systemic sclerosis patients and from bleomycin-treated mice, indicating the central role of caveolin-1 in mesenchymal stromal/stem cell differentiation in fibrotic disease.

An extended high-frequency ultrasound protocol for assessing and quantifying of inflammation and fibrosis in localized scleroderma.

Clinical characteristics of the lesions are used to identify activity and damage in localized scleroderma (LoS). For high-frequency ultrasound (HF-US), the features of active lesions were described. Clinical signs of activity and damage in LoS lesions were assessed with the use of Localized Scleroderma Cutaneous Assessment Tool (LoSCAT) and HF-US by two examiners independently. All US images were obtained using a 20MHz HF-US (DermaLab System, Cortex Technology, Hadsund, Denmark). The dermal thickness (DT) and echogenicity (intensity score, IS) of the LoS lesional dermis were measured in the area of each lesion with the highest score for erythema (ER), skin thickness (ST), and dermal atrophy (DAT). Measurements were compared to the site-matched unaffected skin. The relative difference of DT and IS values was calculated between each lesion and its normal control for comparison among different clinical scores for ER, ST, and DAT. A total of 92 lesions in 40 adult patients were examined with HF-US. Thirty one lesions were erythematous, 26 were in sclerosis, and 35 were in atrophy. A correlation between the clinical evaluation of the LoS lesions and US measurements was found. The sensitivity and specificity of HF-US were 97% and 90%, respectively. The positive predictive value was 83%, negative predictive value-98%. Interrater reliability was excellent for LoSCAT and HF-US findings. High-frequency ultrasound allows an accurate assessment of the inflammatory and fibrotic skin lesions in LoS.

Evaluation of the antifibrotic potency by knocking down SPARC, CCR2 and SMAD3.

BackgroundThe genes of SPARC, CCR2, and SMAD3 are implicated in orchestrating inflammatory response that leads to fibrosis in scleroderma and other fibrotic disorders. The aim of the studies is to evaluate synergistic anti-fibrotic potency of the siRNAs of these genes.MethodsThe efficacy of the siRNA-combination was evaluated in bleomycin-induced mouse fibrosis. The pathological changes of skin and lungs of the mice were assessed by hematoxylin and eosin and Masson's trichrome stains. The expression of inflammation and fibrosis associated genes and proteins in the tissues were assessed by real-time RT-PCR, RNA sequencing, Western blots and ELISA. Non-crosslinked fibrillar collagen was measured by the Sircol colorimetric assay.FindingsThe applications of the combined siRNAs in bleomycin-induced mice achieved favorable anti-inflammatory and anti-fibrotic effects. Activation of fibroblasts was suppressed in parallel with inhibition of inflammation evidenced by reduced inflammatory cells and proinflammatory cytokines in the BALF and/or the tissues by the treatment. Aberrant expression of the genes normally expressed in fibroblasts, monocytes/ macrophage, endothelial and epithelial cells were significantly restrained after the treatment. In addition, transcriptome profiles indicated that some bleomycin-induced alterations of multiple biological pathways were recovered to varying degrees by the treatment.InterpretationThe application of the combined siRNAs of SPARC, CCR2, and SMAD3 genes ameliorated inflammation and fibrosis in bleomycin-induced mice. It systemically reinstated multiple biopathways, probably through controlling on different cell types including fibroblasts, monocytes/macrophages, endothelial cells and others. The multi-target-combined therapeutic approach examined herein may represent a novel and effective therapy for fibrosis.

Ubiquitination in Scleroderma Fibrosis and Its Treatment.

Scleroderma (systemic sclerosis, SSc) is a highly heterogeneous rheumatic disease, and uncontrolled fibrosis in visceral organs is the major cause of death in patients. The transforming growth factor-β (TGF-β) and WNT/β-catenin signaling pathways, along with signal transducer and activator of transcription 3 (STAT3), play crucial roles in this fibrotic process. Currently, no therapy is available that effectively arrests or reverses the progression of fibrosis in patients with SSc. Ubiquitination is an important post-translational modification that controls many critical cellular functions. Dysregulated ubiquitination events have been observed in patients with systemic lupus erythematosus, rheumatoid arthritis and fibrotic diseases. Inhibitors targeting the ubiquitination pathway have considerable potential for the treatment of rheumatic diseases. However, very few studies have examined the role and mechanism of ubiquitination in patients with SSc. In this review, we will summarize the molecular mechanisms of ubiquitination in patients with SSc and explore the potential targets for treatment.

A COMPARISON OF FVC, FVC/DLCO AND TLC/DLCO AS AN INDICATOR FOR INTERSTITIAL LUNG DISEASE IN PATIENTS WITH SCLERODERMA

SESSION TITLE: Characteristics of Interstitial Lung Disease SESSION TYPE: Original Investigations PRESENTED ON: 10/10/2018 02:30 pm - 03:30 pm PURPOSE: Pulmonary function tests (PFTs) have been reported to be unreliable for the identification of interstitial lung disease (ILD) in Scleroderma patients. A normal Forced Vital Capacity [FVC], was reported in 62.5% of these Scleroderma patients with significant ILD on high resolution CT (HRCT) of chest. The correlation of FVC/DLC and TLC/DLCO to pulmonary fibrosis in Scleroderma patients has not been studied. The objective of this study was to compare the correlation between FVC, Total Lung capacity [TLC] / Diffusion Capacity [DLCO]) ratio and FVC/DLCO ratio, respectively, with the extent of ILD measured by a fibrosis score on HRCT of chest in patients with Scleroderma. METHODS: The records of 40 patients with Scleroderma without Pulmonary Arterial Hypertension followed at the rheumatology clinic our institution were reviewed. Patient demographics and PFT parameters (FVC, TLC, and DLCO) were noted. FVC/DLCO and TLC/DLCO was calculated for each patient. Patients’ chest HRCT scans were graded by a radiologist for ILD by a HRCT Fibrosis Score, calculated by estimating the percentage of parenchymal involvement in three zones (upper, middle, lower) of each lung, with a score of 100 representing normal and a score of 400 representing severe fibrosis. PFT variables were recorded as percent predicted (%) and expressed as mean + SD. Pearson’s test for linear correlation was used to determine correlation of Fibrosis Score with respectively-FVC, FVC/DLCO and TLC/ DLCO. RESULTS: Mean age was 58.8 +/- 12.9 years; 76% were females; 74% had limited disease. Mean FVC: 87.80 +/- 23.52 %; mean TLC: 94 +/-15.9 %; mean DLCO :72.8 +/- 21%; mean FVC/DLC: 0.20 +/- 0.5; mean TLC/DLCO: 0.33 +/- 0.08. Normal FVC was seen in 70%; normal TLC in 85%.; normal DLCO in 32.5%. Mean fibrosis score was:105.2 +/- 11.3 (Range: 100-280). Using Pearson’s correlation analysis, correlation between fibrosis-score and respectively FVC, FVC/DLC and TLC/DLCO was as follows: FVC vs. Fibrosis Score: r= -0.313; p=0.04; FVC/DLCO vs. Fibrosis Score: r= -0.119; p=0.46; TLC/DLCO vs. Fibrosis Score: r=0.06; p =0.69. CONCLUSIONS: ILD in Scleroderma, estimated by the Fibrosis score, correlates significantly with FVC but not with FVC/DLCO and TLC/ DLCO. CLINICAL IMPLICATIONS: Despite prior studies reporting FVC as an unreliable indicator of ILD in Scleroderma, our study shows that FVC has a strong correlation with pulmonary fibrosis in Scleroderma. Further studies are needed to re-evaluate this. DISCLOSURES: No relevant relationships by Debapriya Datta, source=Web Response No relevant relationships by Carol Halasan, source=Web Response No relevant relationships by Sophie Korzan, source=Web Response

Octreotide ameliorates dermal fibrosis in bleomycin-induced scleroderma

Insulin-like growth factor (IGF)-I is a differentiation and growth factor. Antifibrotic action of octreotide has been reported in pulmonary fibrosis. The present study aimed to research the prophylactic and therapeutic potential of octreotide on a bleomycin (BLM)-induced experimental scleroderma model. Sixty Balb/c female mice were divided into 6 groups. Daily subcutaneous BLM (100 μg) was injected for 3 weeks in groups II and III and for 6 weeks in groups V and VI. Octreotide (100 μg/kg per day) was injected subcutaneously for the first 3 weeks in group III (prophylactic) and the second 3 weeks in group VI (therapeutic). Mice in groups I, II, and III were sacrificed at the end of the third week, while mice in groups IV, V, and VI were sacrificed at the end of the sixth week. Repeated BLM applications increased dermal inflammatory cell counts and dermal thickness, and led to dermal fibrosis at both the third and sixth weeks. Moreover, mRNA expressions of TGF-β1 and IGF binding protein (IGFBP)-3 and -5 were higher in the BLM- injected sham groups. On the other hand, IGFBP-3 and -5 mRNA expressions were significantly decreased in both the prophylactic and therapeutic octreotide groups. Similarly, octreotide decreased dermal inflammatory infiltrations and dermal thickness. Octreotide has antifibrotic actions on experimentally induced dermal fibrosis. It can be suggested that IGF-I plays pathogenic roles, and octreotide is a candidate for research in the treatment of scleroderma.

BAFF inhibition attenuates fibrosis in scleroderma by modulating the regulatory and effector B cell balance.

Systemic sclerosis (SSc) is an autoimmune disease characterized by skin and lung fibrosis. More than 90% of patients with SSc are positive for autoantibodies. In addition, serum B cell activating factor (BAFF) level is correlated with SSc severity and activity. Thus, B cells are considered to play a pathogenic role in SSc. However, there are two opposing subsets: regulatory B cells (Bregs) and effector B cells (Beffs). Interleukin-10 (IL-10)-producing Bregs negatively regulate the immune response, while IL-6-producing Beffs positively regulate it. Therefore, a protocol that selectively depletes Beffs would represent a potent therapy for SSc. The aims of this study were to investigate the roles of Bregs and Beffs in SSc and to provide a scientific basis for developing a new treatment strategy targeting B cells. A bleomycin-induced scleroderma model was induced in mice with a B cell-specific deficiency in IL-6 or IL-10. We also examined whether BAFF regulates cytokine-producing B cells and its effects on the scleroderma model. IL-6-producing Beffs increased in number and infiltrated the inflamed skin in the scleroderma model. The skin and lung fibrosis was attenuated in B cell-specific IL-6-deficient mice, whereas B cell-specific IL-10-deficient mice showed more severe fibrosis. In addition, BAFF increased Beffs but suppressed Bregs. Furthermore, BAFF antagonist attenuated skin and lung fibrosis in the scleroderma model with reduction of Beffs but not of Bregs. The current study indicates that Beffs play a pathogenic role in the scleroderma model, while Bregs play a protective role. BAFF inhibition is a potential therapeutic strategy for SSc via alteration of B cell balance.

S100A9 aggravates bleomycin-induced dermal fibrosis in mice via activation of ERK1/2 MAPK and NF-κB pathways.

Objective(s):This study aims to investigate the pathogenicity and possible mechanisms of S100A9 function in mice models of scleroderma.Materials and Methods:The content of S100A9 in the skin tissues of mice with scleroderma was determined. Different concentrations of bleomycin (BLM) and S100A9 were subcutaneously injected into the backs of mice simultaneously, and then pathological changes in the skin of these mice were monitored. Specifically, the levels of inflammatory cytokines and alpha smooth muscle actin (α-SMA), the activation of extracellular regulated kinase 1/2 (ERK1/2), mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) pathways, and the expression of the receptor for advanced glycation end-product (RAGE) in the skin were determined.Results:The content of S100A9 in the skin tissues of mice with scleroderma was determined. Different concentrations of BLM and S100A9 were subcutaneously injected into the backs of mice simultaneously, and then pathological changes in the skin of these mice were monitored. Specifically, the levels of inflammatory cytokines and alpha smooth muscle actin (α-SMA), the activation of extracellular regulated kinase 1/2 (ERK1/2) mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) pathways, and the expression of the receptor for advanced glycation end-product (RAGE) in the skin were determined.Conclusion:S100A9 aggravates dermal fibrosis in BLM-induced scleroderma (BIS) mice, and its mechanisms might be mediated by RAGE, ERK1/2, and NF-κB pathway.

Matrix Stiffness: the Conductor of Organ Fibrosis.

Organ fibrosis is a lethal component of scleroderma. The hallmark of scleroderma fibrosis is extensive extracellular matrix (ECM) deposition by activated myofibroblasts, specialized hyper-contractile cells that promote ECM remodeling and matrix stiffening. The purpose of this review is to discuss novel mechanistic insight into myofibroblast activation in scleroderma. Matrix stiffness, traditionally viewed as an end point of organ fibrosis, is now recognized as a critical regulator of tissue fibrogenesis that hijacks the normal physiologic wound-healing program to promote organ fibrosis. Here, we discuss how matrix stiffness orchestrates fibrosis by controlling three fundamental pro-fibrotic mechanisms: (a) mechanoactivation of myofibroblasts, (b) integrin-mediated latent transforming growth factor beta 1 (TGF-β1) activation, and (c) activation of non-canonical TGF-β1 signaling pathways. We also summarize novel therapeutic targets for anti-fibrotic therapy based on the mechanobiology of scleroderma. Future research on mechanobiology of scleroderma may lead to important clinical applications such as improved diagnosis and treatment of patients with scleroderma and other fibrotic-related diseases.

Bone Marrow-Derived Mesenchymal Stem Cells Expressing Thioredoxin 1 Attenuate Bleomycin-Induced Skin Fibrosis and Oxidative Stress in Scleroderma

Systemic sclerosis (SSc) is an autoimmune disorder that affects multiple organs. It is characterized by a thickening of the dermis and connective tissue caused by collagen accumulation, and vascular injuries that induce hypoxia. The present study investigated the therapeutic potential of bone marrow-derived mesenchymal stem cells (BMSCs) expressing thioredoxin 1 (Trx-1) in treating SSc-mediated skin disease after transplantation into a bleomycin-induced murine model. Mice with bleomycin-induced SSc were subcutaneously injected with BMSCs or Trx-1-overexpressing BMSCs and exposed to hypoxic conditions for 48 hours. Two weeks later, skin tissue samples were collected to assess fibrosis, oxidative stress, and angiogenesis by western blotting, ELISA, and histologic and immunofluorescence approaches. Invivo experiments showed that Trx-1-overexpressing BMSCs inhibited hypoxia-induced apoptosis and inhibited fibrosis under hypoxic conditions, possibly by downregulating transforming growth factor-β. Trx-1-overexpressing BMSCs also promoted the formation of tubular-like structures by endothelial progenitor cells, indicating that Trx-1 can promote angiogenesis in bleomycin-induced SSc. These results demonstrate that the transplantation of Trx-1-overexpressing BMSCs restored normal skin tissue in a mouse model of bleomycin-induced SSc, highlighting the therapeutic potential of engineered BMSCs for treating SSc.

Systemic sclerosis in 2016: Dermal white adipose tissue implicated in SSc pathogenesis.

Several strands of new research indicate that skin-specific adipocyte progenitor cells regulate myofibroblasts and skin fibrosis in scleroderma.

MicroRNA-202-3p regulates scleroderma fibrosis by targeting matrix metalloproteinase 1.

The leading cause of death in systemic sclerosis (SSc) is the uncontrolled fibrosis in multiple organs. The exact mechanism of fibrosis is not fully clear. Our previous studies using miRNA array analysis indicated that miR-202-3p was increased in SSc lesion skin tissues. Bioinformatics analysis suggested matrix metallopeptidase (MMP) 1 is the target gene of miR-202-3p. Here we confirmed that miR-202-3p was upregulated, and the mRNA and protein expression of MMP1 were significantly decreased in SSc skin tissues and primary fibroblast compared with normal skin. MMP1 expression was inversely correlated with the expression of miR-202-3p. Overexpression of miR-202-3p markedly increased collagen disposition in skin primary fibroblasts, while inhibitor of miR-202-3p decreased it. Furthermore, we demonstrated that MMP1 was a target of miR-202-3p detected by luciferase reporter assay, and played an essential role as a mediator of the biological effects of miR-202-3p in SSc fibrosis. Taken together, these findings suggest that miR-202-3p may function as a novel pro-fibrotic miRNA in SSc by inhibition the expression of MMP1.