title: Nitric oxide prevents aortic neointimal hyperplasia by controlling macrophage polarization.
abstract: OBJECTIVE
  Nitric oxide synthase 3 (NOS3) prevents neointima hyperplasia by still unknown mechanisms. To demonstrate the significance of endothelial nitric oxide in the polarization of infiltrated macrophages through the expression of matrix metalloproteinase (MMP)-13 in neointima formation.
  
  
  RESULTS
  After aortic endothelial denudation, NOS3 null mice show elevated neointima formation, detecting increased mobilization of LSK (lineage-negative [Lin]-stem-cell antigen 1 [SCA1]+KIT+) progenitor cells, and high ratios of M1 (proinflammatory) to M2 (resolving) macrophages, accompanied by high expression of interleukin-5, interleukin-6, MCP-1 (monocyte chemoattractant protein), VEGF (vascular endothelial growth factor), GM-CSF (granulocyte-macrophage colony stimulating factor), interleukin-1β, and interferon-γ. In conditional c-Myc knockout mice, in which M2 polarization is defective, denuded aortas showed extensive wall thickening as well. Conditioned medium from NOS3-deficient endothelium induced extensive repolarization of M2 macrophages to an M1 phenotype, and vascular smooth muscle cells proliferated and migrated faster in conditioned medium from M1 macrophages. Among the different proteins participating in cell migration, MMP-13 was preferentially expressed by M1 macrophages. M1-mediated vascular smooth muscle cell migration was inhibited when macrophages were isolated from MMP-13-deficient mice, whereas exogenous administration of MMP-13 to vascular smooth muscle cell fully restored migration. Excess vessel wall thickening in mice lacking NOS3 was partially reversed by simultaneous deletion of MMP-13, indicating that NOS3 prevents neointimal hyperplasia by preventing MMP-13 activity. An excess of M1-polarized macrophages that coexpress MMP-13 was also detected in human carotid samples from endarterectomized patients.
  
  
  CONCLUSIONS
  These findings indicate that at least M1 macrophage-mediated expression of MMP-13 in NOS3 null mice induces neointima formation after vascular injury, suggesting that MMP-13 may represent a new promising target in vascular disease.
authors.affiliation: From the Fundación Centro Nacional de Investigaciones Cardiovasculares CNIC Melchor Fernandez Almagro 3, Madrid, Spain (B.L., M.G., O.M.P., B.C., C.Z.); Departmento de Fisiología, Facultad de Medicina, Universidad de Alcala, Ctra Madrid-Barcelona, Alcala de Henares, Spain (M.S.); and Facultad de Medicina, Universidad Francisco de Vitoria, Pozuelo de Alarcon, Madrid, Spain (M.J.P., C.Z.).
authors.forename: Begoña
authors.initials: B
authors.lastname: Lavin
authors.affiliation: From the Fundación Centro Nacional de Investigaciones Cardiovasculares CNIC Melchor Fernandez Almagro 3, Madrid, Spain (B.L., M.G., O.M.P., B.C., C.Z.); Departmento de Fisiología, Facultad de Medicina, Universidad de Alcala, Ctra Madrid-Barcelona, Alcala de Henares, Spain (M.S.); and Facultad de Medicina, Universidad Francisco de Vitoria, Pozuelo de Alarcon, Madrid, Spain (M.J.P., C.Z.).
authors.forename: Monica
authors.initials: M
authors.lastname: Gómez
authors.affiliation: From the Fundación Centro Nacional de Investigaciones Cardiovasculares CNIC Melchor Fernandez Almagro 3, Madrid, Spain (B.L., M.G., O.M.P., B.C., C.Z.); Departmento de Fisiología, Facultad de Medicina, Universidad de Alcala, Ctra Madrid-Barcelona, Alcala de Henares, Spain (M.S.); and Facultad de Medicina, Universidad Francisco de Vitoria, Pozuelo de Alarcon, Madrid, Spain (M.J.P., C.Z.).
authors.forename: Oscar M
authors.initials: OM
authors.lastname: Pello
authors.affiliation: From the Fundación Centro Nacional de Investigaciones Cardiovasculares CNIC Melchor Fernandez Almagro 3, Madrid, Spain (B.L., M.G., O.M.P., B.C., C.Z.); Departmento de Fisiología, Facultad de Medicina, Universidad de Alcala, Ctra Madrid-Barcelona, Alcala de Henares, Spain (M.S.); and Facultad de Medicina, Universidad Francisco de Vitoria, Pozuelo de Alarcon, Madrid, Spain (M.J.P., C.Z.).
authors.forename: Borja
authors.initials: B
authors.lastname: Castejon
authors.affiliation: From the Fundación Centro Nacional de Investigaciones Cardiovasculares CNIC Melchor Fernandez Almagro 3, Madrid, Spain (B.L., M.G., O.M.P., B.C., C.Z.); Departmento de Fisiología, Facultad de Medicina, Universidad de Alcala, Ctra Madrid-Barcelona, Alcala de Henares, Spain (M.S.); and Facultad de Medicina, Universidad Francisco de Vitoria, Pozuelo de Alarcon, Madrid, Spain (M.J.P., C.Z.).
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Piedras
authors.affiliation: From the Fundación Centro Nacional de Investigaciones Cardiovasculares CNIC Melchor Fernandez Almagro 3, Madrid, Spain (B.L., M.G., O.M.P., B.C., C.Z.); Departmento de Fisiología, Facultad de Medicina, Universidad de Alcala, Ctra Madrid-Barcelona, Alcala de Henares, Spain (M.S.); and Facultad de Medicina, Universidad Francisco de Vitoria, Pozuelo de Alarcon, Madrid, Spain (M.J.P., C.Z.).
authors.forename: Marta
authors.initials: M
authors.lastname: Saura
authors.affiliation: From the Fundación Centro Nacional de Investigaciones Cardiovasculares CNIC Melchor Fernandez Almagro 3, Madrid, Spain (B.L., M.G., O.M.P., B.C., C.Z.); Departmento de Fisiología, Facultad de Medicina, Universidad de Alcala, Ctra Madrid-Barcelona, Alcala de Henares, Spain (M.S.); and Facultad de Medicina, Universidad Francisco de Vitoria, Pozuelo de Alarcon, Madrid, Spain (M.J.P., C.Z.). cpatitos@gmail.com.
authors.forename: Carlos
authors.initials: C
authors.lastname: Zaragoza
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D001011:Aorta / Q000378:metabolism / Q000473:pathology; D001018:Aortic Diseases / Q000201:enzymology / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D015415:Biomarkers / Q000378:metabolism; D016022:Case-Control Studies; D002454:Cell Differentiation; D019070:Cell Lineage; D002465:Cell Movement; D049109:Cell Proliferation; D002478:Cells, Cultured; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D006965:Hyperplasia; D018836:Inflammation Mediators / Q000378:metabolism; D008264:Macrophages / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D008297:Male; D053509:Matrix Metalloproteinase 13 / Q000172:deficiency / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008875:Middle Aged; D009131:Muscle, Smooth, Vascular / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D032389:Myocytes, Smooth Muscle / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D058426:Neointima; D009569:Nitric Oxide / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III / Q000172:deficiency / Q000235:genetics; D010641:Phenotype; D016271:Proto-Oncogene Proteins c-myc / Q000172:deficiency / Q000235:genetics; D013997:Time Factors
chemical_list: D015415:Biomarkers; D018836:Inflammation Mediators; C489428:Myc protein, mouse; D016271:Proto-Oncogene Proteins c-myc; D009569:Nitric Oxide; D052250:Nitric Oxide Synthase Type III; C496315:Nos3 protein, mouse; D053509:Matrix Metalloproteinase 13; C507081:Mmp13 protein, mouse
keywords: angioplasty; entothelial nitric oxide synthase 3; macrophage; matrix metalloproteinase-13; neointima