title: Intracellular NAMPT-NAD+-SIRT1 cascade improves post-ischaemic vascular repair by modulating Notch signalling in endothelial progenitors.
abstract: OBJECTIVE
  Intracellular nicotinamide phosphoribosyltransferase (NAMPT) is the rate-limiting enzyme for nicotinamide adenine dinucleotide (NAD(+)) biosynthesis. This study investigated the role of NAMPT-mediated NAD(+) signalling in post-ischaemic vascular repair.
  
  
  RESULTS
  Mouse hind-limb ischaemia up-regulated NAMPT expression and NAD(+) level in bone marrow (BM). Pharmacological inhibition of NAMPT by a chemical inhibitor FK866 impaired the mobilization of endothelial progenitor cells (EPCs) from BM upon ischaemic stress. Transgenic mice overexpressing NAMPT (Tg mice), but not H247A-mutant dominant-negative NAMPT (DN-Tg mice), exhibited enhanced capillary density, increased number of proliferating endothelial cells, improved blood flow recovery, and augmented collateral arterioles in the ischaemic limb. In cultured BM-derived EPCs, inhibition of NAMPT suppressed proliferation, migration, and tube formation, whereas overexpression of NAMPT induced opposite effects. The promoting effects of NAMPT on EPCs were abolished by silencing of sirtuin 1 (SIRT1), rather than silencing of SIRT2-7. Overexpression of NAMPT led to a SIRT1-depedent enhancement of Notch-1 intracellular domain deacetylation, which inhibited Delta-like ligand-4 (DLL4)-Notch signalling and thereby up-regulated of VEGFR-2 and VEGFR-3. Injection of recombinant VEGF induced a more pronounced EPC mobilization in Tg, but not in DN-Tg, mice. Furthermore, overexpression of NAMPT down-regulated Fringe family glycosyltransferases in a SIRT1-dependent manner, which rendered Notch more sensitive to the pro-angiogenic ligand Jagged1 rather than the anti-angiogenic ligand DLL4.
  
  
  CONCLUSIONS
  These results demonstrate that intracellular NAMPT-NAD(+)-SIRT1 cascade improves post-ischaemic neovascularization. The modulation of Notch signalling may contribute to the enhanced post-ischaemic neovascularization.
authors.affiliation: Department of Pharmacology, Second Military Medical University, 325 Guo He Road, Shanghai 200433, China.
authors.forename: Pei
authors.initials: P
authors.lastname: Wang
authors.affiliation: Department of Pharmacology, Second Military Medical University, 325 Guo He Road, Shanghai 200433, China Department of Pharmacy, General Hospital of Lanzhou Military Region, Lanzhou, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Du
authors.affiliation: Department of Pharmacology, Second Military Medical University, 325 Guo He Road, Shanghai 200433, China.
authors.forename: Can-Can
authors.initials: CC
authors.lastname: Zhou
authors.affiliation: Department of Pharmacology, Second Military Medical University, 325 Guo He Road, Shanghai 200433, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Song
authors.affiliation: Institute of Immunology, Second Military Medical University, Shanghai, China.
authors.forename: Xingguang
authors.initials: X
authors.lastname: Liu
authors.affiliation: Institute of Immunology, Second Military Medical University, Shanghai, China.
authors.forename: Xuetao
authors.initials: X
authors.lastname: Cao
authors.affiliation: Division of Cardiovascular Medicine, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
authors.forename: Jawahar L
authors.initials: JL
authors.lastname: Mehta
authors.affiliation: Zhongshan Hospital, Fudan University, Shanghai, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Shi
authors.affiliation: Department of Pharmacology, Second Military Medical University, 325 Guo He Road, Shanghai 200433, China cymiao@smmu.edu.cn dfsu@smmu.edu.cn.
authors.forename: Ding-Feng
authors.initials: DF
authors.lastname: Su
authors.affiliation: Department of Pharmacology, Second Military Medical University, 325 Guo He Road, Shanghai 200433, China cymiao@smmu.edu.cn dfsu@smmu.edu.cn.
authors.forename: Chao-Yu
authors.initials: CY
authors.lastname: Miao
mesh_terms: D000818:Animals; D001853:Bone Marrow / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000378:metabolism; D002196:Capillaries; D016207:Cytokines / Q000037:antagonists & inhibitors / Q000378:metabolism*; D066026:Endothelial Progenitor Cells / Q000378:metabolism*; D005121:Extremities / Q000098:blood supply; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism; D007511:Ischemia / Q000378:metabolism; D000072100:Jagged-1 Protein; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009243:NAD / Q000378:metabolism; D018919:Neovascularization, Physiologic; D054409:Nicotinamide Phosphoribosyltransferase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051880:Receptors, Notch / Q000378:metabolism*; D012039:Regional Blood Flow; D000072099:Serrate-Jagged Proteins; D056564:Sirtuin 1 / Q000378:metabolism*; D015854:Up-Regulation; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism; D040321:Vascular Endothelial Growth Factor Receptor-3 / Q000378:metabolism
chemical_list: D002135:Calcium-Binding Proteins; D016207:Cytokines; D036341:Intercellular Signaling Peptides and Proteins; C000606274:Jag1 protein, mouse; D000072100:Jagged-1 Protein; D008565:Membrane Proteins; D051880:Receptors, Notch; D000072099:Serrate-Jagged Proteins; D009243:NAD; D054409:Nicotinamide Phosphoribosyltransferase; C495867:nicotinamide phosphoribosyltransferase, mouse; C000592875:Kdr protein, mouse; D040301:Vascular Endothelial Growth Factor Receptor-2; D040321:Vascular Endothelial Growth Factor Receptor-3; C470545:Sirt1 protein, mouse; D056564:Sirtuin 1
keywords: Endothelial progenitor cells; Ischaemia; NAMPT; Neovascularization; Visfatin