title: Comparative proteomics profiling reveals role of smooth muscle progenitors in extracellular matrix production.
abstract: OBJECTIVE
  Recent studies on cardiovascular progenitors have led to a new appreciation that paracrine factors may support the regeneration of damaged tissues.
  
  
  RESULTS
  We used a shotgun proteomics strategy to compare the secretome of peripheral blood-derived smooth muscle progenitors (SPCs) with human aortic smooth muscle cells. The late-outgrowth SPCs produced fewer proteolytic enzymes and inflammatory cytokines and showed reduced invasive capacity. Similar to smooth muscle cells, SPCs secreted extracellular matrix. However, SPCs produced different matrix proteins, as evidenced by the truncation of proangiogenic domains in collagen alpha-1 (I) and increased production of periostin. Moreover, SPCs retained serum proteins, including proteoglycans, regulating collagen assembly; and pigment epithelium-derived factor, a potent inhibitor of angiogenesis. As a functional consequence, their conditioned medium was less angiogenic, as demonstrated by endothelial tube formation assays in vitro and implantation of Matrigel plugs into nude, severe combined immunodeficient mice (NOD/SCID).
  
  
  CONCLUSIONS
  The present study represents an important conceptual development, suggesting that SPCs may contribute to extracellular matrix production.
authors.affiliation: Department of Cardiology, Phoenix VA Health Care System, Phoenix, AZ, USA.
authors.forename: David
authors.initials: D
authors.lastname: Simper
authors.forename: Ursula
authors.initials: U
authors.lastname: Mayr
authors.forename: Carmen
authors.initials: C
authors.lastname: Urbich
authors.forename: Anna
authors.initials: A
authors.lastname: Zampetaki
authors.forename: Marianna
authors.initials: M
authors.lastname: Prokopi
authors.forename: Athanasios
authors.initials: A
authors.lastname: Didangelos
authors.forename: Angelika
authors.initials: A
authors.lastname: Saje
authors.forename: Michael
authors.initials: M
authors.lastname: Mueller
authors.forename: Ulrike
authors.initials: U
authors.lastname: Benbow
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Newby
authors.forename: Rolf
authors.initials: R
authors.lastname: Apweiler
authors.forename: Salman
authors.initials: S
authors.lastname: Rahman
authors.forename: Stefanie
authors.initials: S
authors.lastname: Dimmeler
authors.forename: Qingbo
authors.initials: Q
authors.lastname: Xu
authors.forename: Manuel
authors.initials: M
authors.lastname: Mayr
mesh_terms: D000818:Animals; D001011:Aorta / Q000378:metabolism; D001798:Blood Proteins / Q000378:metabolism; D002478:Cells, Cultured; D056148:Chromatography, Reverse-Phase; D017077:Culture Media, Conditioned / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism*; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000378:metabolism*; D032389:Myocytes, Smooth Muscle / Q000378:metabolism*; D018919:Neovascularization, Physiologic; D019899:Paracrine Communication; D010447:Peptide Hydrolases / Q000378:metabolism; D040901:Proteomics / Q000379:methods; D015203:Reproducibility of Results; D013234:Stem Cells / Q000378:metabolism*; D053719:Tandem Mass Spectrometry
chemical_list: D001798:Blood Proteins; D017077:Culture Media, Conditioned; D018836:Inflammation Mediators; D010447:Peptide Hydrolases