title: Analysis of stromal cell secretomes reveals a critical role for stromal cell-derived hepatocyte growth factor and fibronectin in angiogenesis.
abstract: OBJECTIVE
  Angiogenesis requires tightly coordinated crosstalk between endothelial cells (ECs) and stromal cells, such as fibroblasts and smooth muscle cells. The specific molecular mechanisms moderating this process are still poorly understood.
  
  
  RESULTS
  Stromal cell-derived factors are essential for EC sprouting and lumen formation. We therefore compared the abilities of 2 primary fibroblast isolates and a primary smooth muscle cell isolate to promote in vitro angiogenesis, and analyzed their secretomes using a combination of nano liquid chromatography-mass spectrometry/mass spectrometry, quantitative PCR, and ELISA. Each isolate exhibited a different level of angiogenic ability. Using quantitative MS, we then compared the secretomes of a fibroblast isolate exhibiting low angiogenic activity, a fibroblast isolate exhibiting high angiogenic activity, and human umbilical vein ECs. High angiogenic fibroblast supernatants exhibited an overabundance of proteins associated with extracellular matrix constituents compared with low angiogenic fibroblasts or ECs. Finally, small interfering RNA technology and purified protein were used to confirm a role for stromal cell-derived hepatocyte growth factor and fibronectin in inducing EC sprouting.
  
  
  CONCLUSIONS
  Differences in stromal cell ability to induce angiogenesis are a result of differences in the secreted proteomes of both extracellular matrix proteins and proangiogenic growth factors.
authors.affiliation: Department of Molecular Biology and Biochemistry, University of California Irvine, Irvine, CA 92697, USA.
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Newman
authors.forename: Wayne
authors.initials: W
authors.lastname: Chou
authors.forename: Katrina M
authors.initials: KM
authors.lastname: Welch-Reardon
authors.forename: Ashley H
authors.initials: AH
authors.lastname: Fong
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: Popson
authors.forename: Duc Thien
authors.initials: DT
authors.lastname: Phan
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Sandoval
authors.forename: Dananh P
authors.initials: DP
authors.lastname: Nguyen
authors.forename: Paul D
authors.initials: PD
authors.lastname: Gershon
authors.forename: Christopher C W
authors.initials: CC
authors.lastname: Hughes
mesh_terms: D002478:Cells, Cultured; D002853:Chromatography, Liquid; D018920:Coculture Techniques; D004797:Enzyme-Linked Immunosorbent Assay; D005347:Fibroblasts / Q000378:metabolism; D005353:Fibronectins / Q000235:genetics / Q000378:metabolism*; D017228:Hepatocyte Growth Factor / Q000235:genetics / Q000378:metabolism*; D061307:Human Umbilical Vein Endothelial Cells / Q000378:metabolism*; D006801:Humans; D032389:Myocytes, Smooth Muscle / Q000378:metabolism; D036103:Nanotechnology; D018919:Neovascularization, Physiologic; D019899:Paracrine Communication; D040901:Proteomics / Q000379:methods; D034622:RNA Interference; D060888:Real-Time Polymerase Chain Reaction; D017154:Stromal Cells / Q000378:metabolism*; D053719:Tandem Mass Spectrometry; D013997:Time Factors; D014162:Transfection
chemical_list: D005353:Fibronectins; C066855:HGF protein, human; D017228:Hepatocyte Growth Factor