Project description:Systemic sclerosis is a connective tissue disease affecting skin and internal organs, characterized by a triad of inflammation, vasculopathy and progressive fibrosis, due to deposition of mainly type I collagen. Out of the intricate mechanisms involved in the pathogenesis of the disease, evidence indicates that TGFbeta signaling plays a central role in mediating the effects of several pro-fibrotic effectors. In addition, TGFbeta is induced by hypoxia in cultured fibroblasts, an observation suggesting a role for this cytokine in linking vasculopathy and fibrosis in the disease. Not surprisingly, TGFbeta and Wnt signaling are among the most prevalent pathways found in global gene expression studies performed on systemic sclerosis skin biopsies. In this perspective, modulation of TGFbeta activity remains a top therapeutic target in systemic sclerosis drug development. We recently performed whole-body magnetic resonance imaging (MRI) studies in systemic sclerosis patients, and evidenced deep connective tissue infiltrates surrounding tendons in patients with active disease, and tendon friction rubs. Tenosynovitis and arthritis were also found by MRI in one third of the patients. We performed tenosynovial biopsies in patients with clinically active tenosynovitis, in order to evaluate whether such samples would provide additional information on disease mechanisms. Here, we report that these samples are characterized by the over-expression of genes involved in fibrosis, TGFbeta/Wnt signaling, chemokines and cytokines, but also by the concurrent over-expression of several ubiquitin-specific peptidases (USPs). Among the USPs overexpressed in systemic sclerosis tenosynovial biopsies, USP15 is known to specifically deubiquitinate SMAD3, and the TGFbeta Receptor 1. These results triggered us to perform additional experiments in order to test whether USP15 overexpression plays a role in the pathogenesis of systemic sclerosis via decreased ubiquitin-mediated degradation of proteins involved in TGFbeta signaling.
Project description:Systemic sclerosis is associated with skin fibrosis thought mediated by TGFb. This open label clinical trial examines the effect of TGFb inhibition on skin gene expression. Patients 1-9 received two doses 1 mg/kg dose of fresolimumab at baseline and 3 weeks; patients 10-19 received a single 5 mg/kg dose Patients with diffuse cutaneous systemic sclerosis within 2 years of first raynauds had skin biopsies before treatment and the 3-4 weeks, 7 weeks and 24 weeks after treatment with fresolimumab
Project description:Systemic sclerosis-associated interstitial lung disease (SSc-ILD) is the leading cause of death in patients with systemic sclerosis (SSc) with unclear pathogenesis and limited treatment options. Evidence strongly supports an important role for profibrotic, SPP1-expressing macrophages in SSc-ILD. We sought to define the transcriptome and chromatin structural changes of SPP1 SSc-ILD macrophages, so as to better understand their role in promoting fibrosis and to identify transcription factors associated with open chromatin driving their altered phenotype.