Targeting the endothelial progenitor cell surface proteome to identify novel mechanisms that mediate angiogenic efficacy in a rodent model of vascular disease

Physiol Genomics. 2013 Nov 1;45(21):999-1011. doi: 10.1152/physiolgenomics.00097.2013. Epub 2013 Sep 10.


Endothelial progenitor cells (EPCs) promote angiogenesis, and clinical trials suggest autologous EPC-based therapy may be effective in treatment of vascular diseases. Albeit promising, variability in the efficacy of EPCs associated with underlying disease states has hindered the realization of EPC-based therapy. Here we first identify and characterize EPC dysfunction in a rodent model of vascular disease (SS/Mcwi rat) that exhibits impaired angiogenesis. To identify molecular candidates that mediate the angiogenic potential of these cells, we performed a broad analysis of cell surface protein expression using chemical labeling combined with mass spectrometry. Analysis revealed EPCs derived from SS/Mcwi rats express significantly more type 2 low-affinity immunoglobulin Fc-gamma (FCGR2) and natural killer 2B4 (CD244) receptors compared with controls. Genome-wide sequencing (RNA-seq) and qt-PCR confirmed isoforms of CD244 and FCGR2a transcripts were increased in SS/Mcwi EPCs. EPCs with elevated expression of FCGR2a and CD244 receptors are predicted to increase the probability of SS/Mcwi EPCs being targeted for death, providing a mechanistic explanation for their reduced angiogenic efficacy in vivo. Pathway analysis supported this contention, as "key" molecules annotated to cell death paths were differentially expressed in the SS/Mcwi EPCs. We speculate that screening and neutralization of cell surface proteins that "tag" and impair EPC function may provide an alternative approach to utilizing incompetent EPCs in greater numbers, as circulating EPCs are depleted in patients with vascular disease. Overall, novel methods to identify putative targets for repair of EPCs using discovery-based technologies will likely provide a major advance in the field of regenerative medicine.

Keywords: RNA sequencing; angiogenesis; endothelial progenitor cell; genome-wide transcript profiling; proteomics; rat model of vascular disease.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, CD34 / genetics
  • Antigens, CD34 / metabolism
  • Cells, Cultured
  • Electric Stimulation
  • Endothelial Cells / cytology
  • Endothelial Cells / metabolism*
  • Endothelial Cells / transplantation
  • Flow Cytometry
  • Humans
  • Mass Spectrometry
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Muscle, Skeletal / blood supply
  • Muscle, Skeletal / metabolism
  • Neovascularization, Physiologic / genetics
  • Neovascularization, Physiologic / physiology*
  • Proteome / genetics
  • Proteome / metabolism*
  • Rats
  • Rats, Inbred BN
  • Rats, Inbred Dahl
  • Reverse Transcriptase Polymerase Chain Reaction
  • Species Specificity
  • Stem Cell Transplantation / methods
  • Stem Cells / cytology
  • Stem Cells / metabolism*
  • Transcriptome / genetics
  • Vascular Diseases / genetics
  • Vascular Diseases / metabolism
  • Vascular Diseases / physiopathology*
  • Vascular Endothelial Growth Factor Receptor-2 / genetics
  • Vascular Endothelial Growth Factor Receptor-2 / metabolism


  • Antigens, CD34
  • Membrane Proteins
  • Proteome
  • Vascular Endothelial Growth Factor Receptor-2