Computational Protein Design to Reengineer Stromal Cell-Derived Factor-1 alpha Generates an Effective and Translatable Angiogenic Polypeptide Analog

• Authors: William Hiesinger, University of Pennsylvania; Jose Manuel Perez-Aguilar, University of Pennsylvania; Pavan Atluri, University of Pennsylvania; Nicole A. Marotta, University of Pennsylvania; John R. Frederick, University of Pennsylvania; J. Raymond Fitzpatrick, III, University of Pennsylvania; Ryan C. McCormick, University of Pennsylvania; Jeffrey R. Muenzer, University of Pennsylvania; Elaine C. Yang, University of Pennsylvania; Rebecca Levit, Emory University; Li-Jun Yuan, University of Pennsylvania; John W. MacArthur, University of Pennsylvania; Jeffery G. Saven, University of Pennsylvania; Y. Joseph Woo, University of Pennsylvania
• Journal Title: Circulation
• Volume: Volume 124, Number 11
• Publisher: American Heart Association | 2011-09-13, Pages S18-S26
• Type of Work: Article | Post-print: After Peer Review
• Publisher DOI: http://doi.org/10.1161/CIRCULATIONAHA.110.009431
• Subjects: Health Sciences, Medicine and Surgery; Biology, Cell
• Keywords: Science & Technology; Life Sciences & Biomedicine; Cardiac & Cardiovascular Systems; Peripheral Vascular Disease; Cardiovascular System & Cardiology; angiogenesis; cardiac surgery; computer models; computational biology; endothelial cells; progenitor cells; FACTOR-I; CONTRAST ECHOCARDIOGRAPHY; NEOVASCULOGENIC THERAPY; MYOCARDIAL-INFARCTION; VIABILITY; RECRUITMENT; HEART; DYSFUNCTION; INHIBITION; ACTIVATION

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. Methods and 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.