title: Attenuation of neointimal formation with netrin-1 and netrin-1 preconditioned endothelial progenitor cells.
abstract: Restenosis after angioplasty is a serious clinical problem that can result in re-occlusion of the coronary artery. Although current drug-eluting stents have proved to be more effective in reducing restenosis, they have drawbacks of inhibiting reendothelialization to promote thrombosis. New treatment options are in urgent need. We have shown that netrin-1, an axon-guiding protein, promotes angiogenesis and cardioprotection via production of nitric oxide (NO). The present study examined whether and how netrin-1 attenuates neointimal formation in a femoral wire injury model. Infusion of netrin-1 into C57BL/6 mice markedly attenuated neointimal formation following wire injury of femoral arteries, measured by intimal to media ratio (from 1.94 ± 0.55 to 0.45 ± 0.86 at 4 weeks). Proliferation of VSMC in situ was largely reduced. This protective effect was absent in DCC+/-animals. NO production was increased by netrin-1 in both intact and injured femoral arteries, indicating netrin-1 stimulation of endogenous NO production from intact endothelium and remaining endothelial cells post-injury. VSMC migration was abrogated by netrin-1 via a NO/cGMP/p38 MAPK pathway, while timely EPC homing was induced. Injection of netrin-1 preconditioned wild-type EPCs, but not EPCs of DCC+/-animals, substantially attenuated neointimal formation. EPC proliferation, NO production, and resistance to oxidative stress induced apoptosis were augmented by netrin-1 treatment. In conclusion, our data for the first time demonstrate that netrin-1 is highly effective in reducing neointimal formation following vascular endothelial injury, which is dependent on DCC, and attributed to inhibition of VSMC proliferation and migration, as well as improved EPC function. These data may support usage of netrin-1 and netrin-1 preconditioned EPCs as novel therapies for post angioplasty restenosis.
  
  
  
  Netrin-1 attenuates neointimal formation following post endothelial injury via DCC and NO. Netrin-1 inhibits VSMC proliferation in situ following endothelial injury. Netrin-1 inhibits VSMC migration via a NO/cGMP/p38 MAPK pathway. Netrin-1 augments proliferation of endothelial progenitor cells (EPCs) and EPC eNOS/NO activation. Netrin-1 enhances resistance of EPCs to oxidative stress, improving re-endothelialization following injury.
authors.affiliation: Divisions of Molecular Medicine and Cardiology, Departments of Anesthesiology and Medicine, Cardiovascular Research Laboratories, David Geffen School of Medicine at University of California Los Angeles, 650 Charles E. Young Drive, Los Angeles, CA, 90095, USA.
authors.forename: Norika Mengchia
authors.initials: NM
authors.lastname: Liu
authors.affiliation: Divisions of Molecular Medicine and Cardiology, Departments of Anesthesiology and Medicine, Cardiovascular Research Laboratories, David Geffen School of Medicine at University of California Los Angeles, 650 Charles E. Young Drive, Los Angeles, CA, 90095, USA.
authors.forename: Kin Lung
authors.initials: KL
authors.lastname: Siu
authors.affiliation: Divisions of Molecular Medicine and Cardiology, Departments of Anesthesiology and Medicine, Cardiovascular Research Laboratories, David Geffen School of Medicine at University of California Los Angeles, 650 Charles E. Young Drive, Los Angeles, CA, 90095, USA.
authors.forename: Ji Youn
authors.initials: JY
authors.lastname: Youn
authors.affiliation: Divisions of Molecular Medicine and Cardiology, Departments of Anesthesiology and Medicine, Cardiovascular Research Laboratories, David Geffen School of Medicine at University of California Los Angeles, 650 Charles E. Young Drive, Los Angeles, CA, 90095, USA. hcai@mednet.ucla.edu.
authors.forename: Hua
authors.initials: H
authors.lastname: Cai
mesh_terms: D000818:Animals; D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D000075389:DCC Receptor / Q000378:metabolism; D066026:Endothelial Progenitor Cells / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D008297:Male; D008810:Mice, Inbred C57BL; D058426:Neointima / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D000075388:Netrin-1 / Q000627:therapeutic use*; D009569:Nitric Oxide / Q000378:metabolism*; D020011:Protective Agents / Q000627:therapeutic use*; D051381:Rats; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D000075389:DCC Receptor; C501910:Dcc protein, mouse; D020011:Protective Agents; D000075388:Netrin-1; D009569:Nitric Oxide
keywords: Deleted in colorectal cancer (DCC); EPC homing; EPC proliferation; EPC resistance to oxidative stress; Endothelial nitric oxide synthase (eNOS) phosphorylation; Endothelial progenitor cells (EPCs); Femoral wire injury; NO production; Neointimal formation; Netrin-1; Re-endothelialization; VSMC migration; Vascular smooth muscle cell (VSMC) proliferation