title: Intrinsic Deregulation of Vascular Smooth Muscle and Myofibroblast Differentiation in Mesenchymal Stromal Cells from Patients with Systemic Sclerosis.
abstract: BACKGROUND
  Obliterative vasculopathy and fibrosis are hallmarks of systemic sclerosis (SSc), a severe systemic autoimmune disease. Bone marrow-derived mesenchymal stromal cells (MSCs) from SSc patients may harbor disease-specific abnormalities. We hypothesized disturbed vascular smooth muscle cell (VSMC) differentiation with increased propensity towards myofibroblast differentiation in response to SSc-microenvironment defining growth factors and determined responsible mechanisms.
  
  
  METHODS
  We studied responses of multipotent MSCs from SSc-patients (SSc-MSCs) and healthy controls (H-MSCs) to long-term exposure to CTGF, b-FGF, PDGF-BB or TGF-β1. Differentiation towards VSMC and myofibroblast lineages was analyzed on phenotypic, biochemical, and functional levels. Intracellular signaling studies included analysis of TGF-β receptor regulation, SMAD, AKT, ERK1/2 and autocrine loops.
  
  
  RESULTS
  VSMC differentiation towards both, contractile and synthetic VSMC phenotypes in response to CTGF and b-FGF was disturbed in SSc-MSCs. H-MSCs and SSc-MSCs responded equally to PDGF-BB with prototypic fibroblastic differentiation. TGF-β1 initiated myofibroblast differentiation in both cell types, yet with striking phenotypic and functional differences: In relation to H-MSC-derived myofibroblasts induced by TGF-β1, those obtained from SSc-MSCs expressed more contractile proteins, migrated towards TGF-β1, had low proliferative capacity, and secreted higher amounts of collagen paralleled by reduced MMP expression. Higher levels of TGF-β receptor 1 and enhanced canonical and noncanonical TGF-β signaling in SSc-MSCs accompanied aberrant differentiation response of SSc-MSCs in comparison to H-MSCs.
  
  
  CONCLUSIONS
  Deregulated VSMC differentiation with a shift towards myofibroblast differentiation expands the concept of disturbed endogenous regenerative capacity of MSCs from SSc patients. Disease related intrinsic hyperresponsiveness to TGF-β1 with increased collagen production may represent one responsible mechanism. Better understanding of repair barriers and harnessing beneficial differentiation processes in MSCs could widen options of autologous MSC application in SSc patients.
authors.affiliation: Clinic for Nephrology and Intensive Care Medicine, Charité University Hospital, Berlin, Germany.|Berlin-Brandenburg School for Regenerative Therapies (BSRT), Berlin, Germany.|Center for Cardiovascular Research (CCR), Charitè University Hospital, Berlin, Germany.
authors.forename: Björn
authors.initials: B
authors.lastname: Hegner
authors.affiliation: Clinic for Nephrology and Intensive Care Medicine, Charité University Hospital, Berlin, Germany.|Berlin-Brandenburg School for Regenerative Therapies (BSRT), Berlin, Germany.|Center for Cardiovascular Research (CCR), Charitè University Hospital, Berlin, Germany.|Institute for Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany.
authors.forename: Theres
authors.initials: T
authors.lastname: Schaub
authors.affiliation: Clinic for Nephrology and Intensive Care Medicine, Charité University Hospital, Berlin, Germany.|Center for Cardiovascular Research (CCR), Charitè University Hospital, Berlin, Germany.
authors.forename: Rusan
authors.initials: R
authors.lastname: Catar
authors.affiliation: Clinic for Nephrology and Intensive Care Medicine, Charité University Hospital, Berlin, Germany.|Center for Cardiovascular Research (CCR), Charitè University Hospital, Berlin, Germany.
authors.forename: Angelika
authors.initials: A
authors.lastname: Kusch
authors.affiliation: Clinic for Nephrology and Intensive Care Medicine, Charité University Hospital, Berlin, Germany.
authors.forename: Philine
authors.initials: P
authors.lastname: Wagner
authors.affiliation: Experimental and Clinical Research Center, Charité Medical Faculty and the Max-Delbrück Center for Molecular Medicine, Berlin, Germany.
authors.forename: Kirill
authors.initials: K
authors.lastname: Essin
authors.affiliation: Clinic for Stem Cell Transplantation, Department of Cell and Gene Therapy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Lange
authors.affiliation: Clinic for Rheumatology and Clinical Immunology, Charité University Hospital, Berlin, Germany.
authors.forename: Gabriela
authors.initials: G
authors.lastname: Riemekasten
authors.affiliation: Clinic for Nephrology and Intensive Care Medicine, Charité University Hospital, Berlin, Germany.|Berlin-Brandenburg School for Regenerative Therapies (BSRT), Berlin, Germany.|Center for Cardiovascular Research (CCR), Charitè University Hospital, Berlin, Germany.
authors.forename: Duska
authors.initials: D
authors.lastname: Dragun
mesh_terms: D000328:Adult; D000368:Aged; D000077214:Becaplermin; D015415:Biomarkers / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation; D002478:Cells, Cultured; D055513:Connective Tissue Growth Factor / Q000494:pharmacology; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology; D005786:Gene Expression Regulation; D006801:Humans; D008297:Male; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000187:drug effects; D008875:Middle Aged; D009131:Muscle, Smooth, Vascular / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D058628:Myofibroblasts / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D020574:Proto-Oncogene Proteins c-sis / Q000494:pharmacology; D012595:Scleroderma, Systemic / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D015398:Signal Transduction / Q000187:drug effects; D053773:Transforming Growth Factor beta1 / Q000494:pharmacology
chemical_list: D015415:Biomarkers; D020574:Proto-Oncogene Proteins c-sis; D053773:Transforming Growth Factor beta1; D016222:Fibroblast Growth Factor 2; D055513:Connective Tissue Growth Factor; D000077214:Becaplermin