title: Fibroblasts and Mesenchymal Stromal/Stem Cells Are Phenotypically Indistinguishable.
abstract: Human mesenchymal stromal/stem cells (MSCs), derived from many different tissues, are characterized by a fibroblast-like morphology, the expression of certain cell surface markers and their ability to differentiate into adipocytes, chondrocytes and osteoblasts. A number of studies have shown that MSCs share many characteristics with fibroblasts; however, there is no well-defined set of phenotypic characteristics that could distinguish between these 2 types of cells.
  
  
  
  We used 4 well-established human fibroblast strains from 3 different tissue sources and several human MSC strains from 2 different tissue sources to compare the phenotypic and immunological characteristics of these cells.
  
  
  
  Fibroblast strains had a similar morphology to MSCs, expressed the same cell surface markers as MSCs and could also differentiate into adipocytes, chondrocytes and osteoblasts. Also, similar to MSCs, these fibroblasts were capable of suppressing T cell proliferation and modulating the immunophenotype of macrophages. We also show that MSCs deposit extracellular matrices of collagen type I and fibronectin, and express FSP1 in patterns similar to fibroblasts.
  
  
  
  Based on currently accepted definitions for cultured human MSCs and fibroblasts, we could not find any immunophenotypic property that could make a characteristic distinction between MSCs and fibroblasts.
authors.affiliation: Department of Medicine, University of Wisconsin-Madison, School of Medicine and Public Health, Madison, Wis., USA.
authors.forename: Ryan A
authors.initials: RA
authors.lastname: Denu
authors.forename: Steven
authors.initials: S
authors.lastname: Nemcek
authors.forename: Debra D
authors.initials: DD
authors.lastname: Bloom
authors.forename: A Daisy
authors.initials: AD
authors.lastname: Goodrich
authors.forename: Jaehyup
authors.initials: J
authors.lastname: Kim
authors.forename: Deane F
authors.initials: DF
authors.lastname: Mosher
authors.forename: Peiman
authors.initials: P
authors.lastname: Hematti
mesh_terms: D002454:Cell Differentiation; D049109:Cell Proliferation; D002478:Cells, Cultured; D005347:Fibroblasts / Q000166:cytology; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology; D010006:Osteoblasts / Q000166:cytology