LGR5 expressing skin fibroblasts define a major hub perturbed in Systemic Sclerosis
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ABSTRACT: Systemic sclerosis (SSc) is an incurable autoimmune disease with high morbidity and mortality rates, with no effective treatment. Here, we conducted a population scale single-cell genomic analysis of skin and blood samples of 56 healthy controls, and 97 SSc patients at different stages of disease. We found immune compartment activation in only a subset of diffuse SSc patients, but global dysregulation of the stromal compartment, including a novel subset of LGR5+ scleroderma associated fibroblasts (ScAF). ScAF cells are mainly localized in the deep reticular dermis of healthy subjects and are dramatically perturbed morphologically and molecularly in SSc patients. Single-cell multiome profiling of the epigenetic and transcriptional landscapes of stromal cells in healthy subjects and SSc patients, revealed ScAF-specific markers, pathways, and transcription factors important in disease development. Systematic analysis combining the clinical metadata and molecular features of the patients, associates specific ScAF targets with disease pathogenesis and SSc clinical traits. Our study provides a high-resolution atlas of the entire spectrum of sclerodermatous skin, proposing a paradigm shift in the understanding of SSc disease and facilitating the development of new biomarkers and therapeutic strategies for SSc.
Project description:Systemic sclerosis (SSc) is confounded by considerable disease heterogeneity. Animal models of SSc that recapitulate distinct subsets of disease at the molecular level have not delineated. We applied interspecies comparative analysis of genomic data from multiple mouse models of SSc and patients with SSc to determine which animal models best reflect the SSc intrinsic gene expression subsets. Gene expression measured in skin from mice with sclerodermatous graft-versus-host disease, bleomycin-induced fibrosis, or Tsk1/+ and Tsk2/+ mice was mapped to human orthologs and compared to SSc skin biopsy-derived gene expression.
Project description:Systemic sclerosis (SSc) is confounded by considerable disease heterogeneity. Animal models of SSc that recapitulate distinct subsets of disease at the molecular level have not delineated. We applied interspecies comparative analysis of genomic data from multiple mouse models of SSc and patients with SSc to determine which animal models best reflect the SSc intrinsic gene expression subsets. Gene expression measured in skin from mice with sclerodermatous graft-versus-host disease, bleomycin-induced fibrosis, or Tsk1/+ and Tsk2/+ mice was mapped to human orthologs and compared to SSc skin biopsy-derived gene expression.
Project description:Systemic sclerosis (SSc) is confounded by considerable disease heterogeneity. Animal models of SSc that recapitulate distinct subsets of disease at the molecular level have not delineated. We applied interspecies comparative analysis of genomic data from multiple mouse models of SSc and patients with SSc to determine which animal models best reflect the SSc intrinsic gene expression subsets. Gene expression measured in skin from mice with sclerodermatous graft-versus-host disease, bleomycin-induced fibrosis, or Tsk1/+ and Tsk2/+ mice was mapped to human orthologs and compared to SSc skin biopsy-derived gene expression.
Project description:Patients with the diffuse avascular form of Systemic Sclerosis (SSc) and healthy controls (N) were used as sources of microvascular endothelial cells (MVEC). MVEC were obtained from biopsies of involved skin of the hands in 6 SSc patients and from 6 healthy patients undergoing surgery for traumatic events at the hands. The controls were matched by age and sex to the SSc cases. All patients fulfilled the American College of Rheumatology criteria for SSc, as well as the criteria for the diffuse form of the disease.
Project description:Systemic sclerosis (SSc) is an autoimmune disease characterized by vascular damage, and fibrosis of the skin and internal organs. Because activated and oligoclonally expanded CD8+ T cells can be detected in peripheral blood and lung of SSc patients, effector memory CD8+ T cells may play a critical role for organ involvement in SSc; however, the pathogenic functions of effector memory CD8+ T cells remain incompletely understood. Here we performed DNA microarray analysis of the sort-purified effector memory CD8+ T cells from SSc patients and healthy controls, and showed that the expression of genes related to immune response and cell adhesion, including CD226 (also known as DNAX accessory molecule-1, DNAM-1), was significantly altered. Moreover, detailed analysis of CD226 revealed that CD226highCD8+ T cells were increased in SSc patients (mean, 50.7%) compared with healthy controls (32.9%) and were appreciably associated with the severity of skin sclerosis and interstitial lung disease. Further, CD226highCD8+ T cells from SSc patients produced abundant IL-13 and were positively correlated with the cytotoxic capacity of CD8+ T cells against HUVECs. Finally, the neutralization of CD226 impaired IL-13 production and cytolysis against HUVECs. These findings indicate that upregulated CD226 expression on CD8+ T cells reflects disease severity and are involved in SSc pathogenesis via the production of profibrotic IL-13 and endothelial cell injury, and that CD226 may be a useful target in the treatment of SSc. We first purified effector memory CD8+ T cells (CD3+CD8+CD45RO+CD62L+ cells) from peripheral blood by cell sorting and subsequently performed cDNA microarray analysis of the sort-purified effector memory CD8+ T cells from 9 SSc patients and 5 healthy controls.
Project description:There is a pressing need to identify early biomarkers of lung involvement in systemic sclerosis (SSc) to start as soon as possible antifibrotic therapy. We aimed to identify extracellular vesicle-derived microRNAs (EV-miRNAs) that are differentially expressed between SSc patients with and without interstitial lung disease (ILD) and explore their diagnostic value. Small EVs derived from plasma were isolated from 20 well-characterised SSc patients with ILD (SSc-ILD, n=10), without ILD (SSc-no ILD, n=10) and 10 matched healthy subjects (HS). Small RNA sequencing was used to identify sEV-miRNAs associated to SSc-ILD.
Project description:Systemic sclerosis (SSc) shows complex clinical manifestations including progressive skin and internal organ fibrosis. SSc can be divided into 'intrinsic subsets' by gene expression suggesting patient-specific heterogeneity in pathogenesis or temporal evolution of disease. Here we validate these subsets using an independent patient population, and test whether the genes vary over time with patients changing subsets as disease progresses, or if the genes are a stable feature of the patients within each subset. Skin biopsies were analyzed from 13 dSSc patients enrolled in an open label study of rituximab, 9 dSSc patients not treated with rituximab, and 9 healthy controls. These data recapitulate the patient 'intrinsic subsets' described previously with gene expression associated with cell proliferation, inflammatory processes, and a normal-like group. Serial skin biopsies showed consistent and non-progressing gene expression. We were unable to detect significant differences in gene expression before and after rituximab treatment, consistent with an apparent lack of clinical response. Serial biopsies from each patient stayed within the same gene expression subset regardless of treatment regimen or the time point at which they were taken. This demonstrates the intrinsic subsets are an inherent, reproducible and stable feature of SSc that is independent of disease duration. Skin biopsies were analyzed from 13 dSSc patients enrolled in an open label study of rituximab, 9 dSSc patients not treated with rituximab, and 9 healthy controls.
Project description:Type I IFNs are implicated in the pathophysiology of systemic sclerosis (SSc). Recently, a Phase I open-label trial was conducted with an anti-IFNAR1 receptor antibody (anifrolumab) in adult SSc patients. In this study, we aim to assess the downstream effects of anifrolumab and elucidate the role of type I IFN in SSc. Serum proteins and extracellular matrix (ECM) markers were measured in relation to IFN pathway activation status and SSc disease activity. Our results demonstrated a robust overexpression of multiple serum proteins in SSc patients, particularly those with an elevated baseline type I IFN gene signature. Anifrolumab administration was associated with significant downregulation of T cell–associated proteins and upregulation of type III collagen degradation marker. Whole-blood and skin microarray results also indicated the inhibition of T cell receptor and ECM–related transcripts by anifrolumab. In summary, our study demonstrates suppressive effects of anifrolumab on T cell activation and collagen accumulation through which tissue fibrosis may be reduced in SSc patients. The relationship between these peripheral markers and the clinical response to anifrolumab may be examined in larger double-blind, placebo-controlled trials. PAXGene whole blood tubes were collected from 29 SSc subjects at baseline and day 56 after anifrolumab administration, and skin biopsies were procured from 10 SSc subjects at baseline and day 28 after multiple-doses of anifrolumab administration.
Project description:Integration of differential expression (DE) and expression QTL (eQTL) analysis in monocyte-derived macrophages (MDMs) from systemic sclerosis (SSc) patients and healthy controls reveals (i) changes in macrophage transcriptome as an important contributor in SSc and (ii) cis-regulation in GSDMA as a disease risk in macrophages, but not skin.
Project description:To identify potential dysregulation of miRNA expression in plasmacytoid dendritic cells from Systemic Sclerosis patients (SSc), miRNA profiling was performed in pDCs from healthy donors or patients with the most severe fibrotic cutaneous form of SSc, namely in dcSSc, with either disease duration shorter (edcSSc) or longer than two years (ldcSSc). Plasmacytoid dendritic cells (pDCs) are a critical source of type I interferons (IFNs) that can contribute to the onset and maintenance of autoimmunity. Molecular mechanisms leading to pDC dysregulation and persistent type I IFN signature are largely unexplored, especially in systemic sclerosis (SSc), a disease in which pDCs infiltrate fibrotic skin lesions and produce higher levels of IFNa as compared to healthy controls. To investigate potential microRNA–mediated epigenetic mechanisms underlying pDC dysregulation and type I IFN production in SSc. microRNA expression profiling and validation was performed in highly purified pDCs obtained from the peripheral blood of 3 independent cohorts of healthy controls and SSc patients. Possible functions of miR-618 on pDC biology were identified by overexpression in healthy pDCs. miR-618 expression was upregulated in pDCs of SSc patients, including those in the early stage of disease onset and not presenting with skin fibrosis. IRF8, a crucial transcription factor for pDC development and activation, was identified as a target of miR-618. miR-618 overexpression reduced the development of pDCs from CD34+ cells in-vitro and enhanced their ability to secrete IFNα, mimicking the pDC phenotype observed in SSc patients. miR-618 upregulation suppresses pDC development and increases their ability to secrete IFNα, potentially contributing to the type I IFN signature observed in SSc patients. Considering the importance of pDCs in the pathogenesis of SSc and other diseases characterized by a type I IFN signature, miR-618 potentially represents an important epigenetic target to regulate immune system homeostasis in these conditions.