title: Computational protein design to reengineer stromal cell-derived factor-1α generates an effective and translatable angiogenic polypeptide analog.
abstract: BACKGROUND
  Experimentally, exogenous administration of recombinant stromal cell-derived factor-1α (SDF) enhances neovasculogenesis and cardiac function after myocardial infarction. Smaller analogs of SDF may provide translational advantages including enhanced stability and function, ease of synthesis, lower cost, and potential modulated delivery via engineered biomaterials. In this study, computational protein design was used to create a more efficient evolution of the native SDF protein.
  
  
  RESULTS
  Protein structure modeling was used to engineer an SDF polypeptide analog (engineered SDF analog [ESA]) that splices the N-terminus (activation and binding) and C-terminus (extracellular stabilization) with a diproline segment designed to limit the conformational flexibility of the peptide backbone and retain the relative orientation of these segments observed in the native structure of SDF. Endothelial progenitor cells (EPCs) in ESA gradient, assayed by Boyden chamber, showed significantly increased migration compared with both SDF and control gradients. EPC receptor activation was evaluated by quantification of phosphorylated AKT, and cells treated with ESA yielded significantly greater phosphorylated AKT levels than SDF and control cells. Angiogenic growth factor assays revealed a distinct increase in angiopoietin-1 expression in the ESA- and SDF-treated hearts. In addition, CD-1 mice (n=30) underwent ligation of the left anterior descending coronary artery and peri-infarct intramyocardial injection of ESA, SDF-1α, or saline. At 2 weeks, echocardiography demonstrated a significant gain in ejection fraction, cardiac output, stroke volume, and fractional area change in mice treated with ESA compared with controls.
  
  
  CONCLUSIONS
  Compared with native SDF, a novel engineered SDF polypeptide analog (ESA) more efficiently induces EPC migration and improves post-myocardial infarction cardiac function and thus offers a more clinically translatable neovasculogenic therapy.
authors.affiliation: Division of Cardiovascular Surgery, Department of Surgery, University of Pennsylvania School of Medicine, Philadelphia, PA, USA.
authors.forename: William
authors.initials: W
authors.lastname: Hiesinger
authors.forename: Jose Manuel
authors.initials: JM
authors.lastname: Perez-Aguilar
authors.forename: Pavan
authors.initials: P
authors.lastname: Atluri
authors.forename: Nicole A
authors.initials: NA
authors.lastname: Marotta
authors.forename: John R
authors.initials: JR
authors.lastname: Frederick
authors.forename: J Raymond
authors.initials: JR
authors.lastname: Fitzpatrick
authors.forename: Ryan C
authors.initials: RC
authors.lastname: McCormick
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Muenzer
authors.forename: Elaine C
authors.initials: EC
authors.lastname: Yang
authors.forename: Rebecca D
authors.initials: RD
authors.lastname: Levit
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: Yuan
authors.forename: John W
authors.initials: JW
authors.lastname: Macarthur
authors.forename: Jeffery G
authors.initials: JG
authors.lastname: Saven
authors.forename: Y Joseph
authors.initials: YJ
authors.lastname: Woo
mesh_terms: D042501:Angiogenic Proteins / Q000737:chemistry* / Q000494:pharmacology* / Q000627:therapeutic use; D000818:Animals; D002302:Cardiac Output / Q000187:drug effects / Q000502:physiology; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D054377:Chemokine CXCL12 / Q000737:chemistry* / Q000494:pharmacology* / Q000627:therapeutic use; D019295:Computational Biology / Q000379:methods*; D003331:Coronary Vessels / Q000187:drug effects / Q000502:physiology; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D023421:Models, Animal; D009203:Myocardial Infarction / Q000503:physiopathology / Q000517:prevention & control; D018919:Neovascularization, Physiologic / Q000187:drug effects* / Q000502:physiology; D015202:Protein Engineering / Q000379:methods*; D051381:Rats; D017208:Rats, Wistar; D013234:Stem Cells / Q000166:cytology / Q000187:drug effects; D013318:Stroke Volume / Q000187:drug effects / Q000502:physiology
chemical_list: D042501:Angiogenic Proteins; D054377:Chemokine CXCL12