title: Protease-resistant stromal cell-derived factor-1 for the treatment of experimental peripheral artery disease.
abstract: BACKGROUND
  Peripheral artery disease is a potentially incapacitating disease for which pharmacological options are limited. Stromal cell-derived factor-1 (SDF-1) is a chemokine that attracts endothelial progenitor cells and promotes angiogenesis. Therapeutic use of SDF-1 in hindlimb ischemia may be challenged by proteolytic degradation. We hypothesized that protease-resistant variants of SDF-1 can increase blood flow in an experimental model of hindlimb ischemia.
  
  
  RESULTS
  We screened a peptide library for mutations in SDF-1 that provide resistance to matrix metalloproteinase cleavage. Recombinant SDF-1 proteins carrying the mutations were designed, expressed, and purified, and activity of mutant proteins was tested with receptor activation assays and in vivo Matrigel plug assays. SSDF-1(S4V), which is resistant to both dipeptidylpeptidase IV/CD26 and matrix metalloproteinase-2 cleavage, was active in vitro and induced angiogenesis in vivo. We then designed and purified fusion proteins of SSDF-1 and SSDF-1(S4V) with the sequence of self-assembling peptide nanofibers for incorporation into nanofibers. In a blinded and randomized hindlimb ischemia mouse study, SSDF-1(S4V) delivery by nanofibers improved blood flow as measured by laser Doppler from 23.1±1.9% (untreated control) to 55.1±5.7% 6 weeks after surgery (P<0.001). Nanofibers alone or SSDF-1 delivered by nanofibers did not improve blood flow. Furthermore, SSDF-1(S4V) delivered by nanofibers increased formation of new arterioles. In vitro, SSDF-1(S4V) attracts smooth muscle cells but does not induce mitosis.
  
  
  CONCLUSIONS
  SDF-1 engineered to be resistant to dipeptidylpeptidase IV/CD26 and matrix metalloproteinase-2 cleavage and delivered by nanofibers improves blood flow in a model of peripheral artery disease.
authors.affiliation: Provasculon Inc., Cambridge, MA 02142, USA. vincent.segers@provasculon.com
authors.forename: Vincent F M
authors.initials: VF
authors.lastname: Segers
authors.forename: Vyacheslav
authors.initials: V
authors.lastname: Revin
authors.forename: Weitao
authors.initials: W
authors.lastname: Wu
authors.forename: Helen
authors.initials: H
authors.lastname: Qiu
authors.forename: Zheng
authors.initials: Z
authors.lastname: Yan
authors.forename: Richard T
authors.initials: RT
authors.lastname: Lee
authors.forename: Anthony
authors.initials: A
authors.lastname: Sandrasagra
mesh_terms: D000818:Animals; D001160:Arterioles / Q000502:physiology; D002465:Cell Movement / Q000502:physiology; D054377:Chemokine CXCL12 / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D018819:Dipeptidyl Peptidase 4 / Q000378:metabolism; D004195:Disease Models, Animal; D006614:Hindlimb / Q000098:blood supply*; D006801:Humans; D007511:Ischemia / Q000188:drug therapy*; D019169:Jurkat Cells; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000502:physiology; D057139:Nanofibers; D018919:Neovascularization, Physiologic / Q000187:drug effects*; D058729:Peripheral Arterial Disease / Q000188:drug therapy*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology
chemical_list: D054377:Chemokine CXCL12; D011994:Recombinant Proteins; C042807:DPP4 protein, human; D018819:Dipeptidyl Peptidase 4; D020778:Matrix Metalloproteinase 2; C522362:Mmp2 protein, mouse