title: Novel role of reactive oxygen species-activated Trp melastatin channel-2 in mediating angiogenesis and postischemic neovascularization.
abstract: OBJECTIVE
  Transient receptor potential melastatin-2 (TRPM2) channel is a nonselective cation channel that mediates influx of Ca(2+) and Na(+) with relative permeability of PCa:PNa ≈0.6 in response to cellular oxidative stress. As angiogenesis and ischemic neovascularization are both significantly dependent on oxidant signaling, here we investigated the possible role of vascular endothelial growth factor (VEGF)-induced reactive oxygen species production in activating TRPM2-dependent Ca(2+) signaling and in the mechanism of angiogenesis and ischemic neovascularization.
  
  
  RESULTS
  We observed that VEGF stimulation rapidly induced the association of TRPM2 and cellular Src kinase with vascular endothelial-cadherin forming a signalplex at vascular endothelial-cadherin junctions in endothelial cells. Using endothelial cells isolated from TRPM2(-/-) mice or after small interfering RNA depletion of TRPM2, we demonstrated that TRPM2-activated Ca(2+) signaling was required for cellular Src kinase-induced phosphorylation of vascular endothelial-cadherin at Y658 and Y731, the crucial sites involved in vascular endothelial-cadherin internalization in response to VEGF. VEGF-induced reactive oxygen species generation activated TRPM2-induced Ca(2+) entry, whereas the reactive oxygen species-insensitive TRPM2 mutant (C1008→A) showed impaired Ca(2+) entry. Endothelial cells depleted of TRPM2 also displayed significantly perturbed migratory phenotype and impaired activation of cellular Src in response to VEGF. TRPM2(-/-) mice reconstituted with wild-type myeloid cells demonstrated aberrant angiogenesis and neovascularization in the hindlimb ischemia model as compared with wild-type mice.
  
  
  CONCLUSIONS
  VEGF-induced angiogenesis and postischemic neovascularization in mice required reactive oxygen species generation in endothelial cells and resultant TRPM2 activation. Thus, our findings provide novel insight into the role of TRPM2 in mechanism of angiogenesis and ischemic neovascularization.
authors: From the Department of Pharmacology, Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago.
authors: Manish
authors: M
authors: Mittal
authors: From the Department of Pharmacology, Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago.
authors: Norifumi
authors: N
authors: Urao
authors: From the Department of Pharmacology, Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago.
authors: Claudie M
authors: CM
authors: Hecquet
authors: From the Department of Pharmacology, Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago.
authors: Min
authors: M
authors: Zhang
authors: From the Department of Pharmacology, Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago.
authors: Varadarajan
authors: V
authors: Sudhahar
authors: From the Department of Pharmacology, Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago.
authors: Xiao-Pei
authors: XP
authors: Gao
authors: From the Department of Pharmacology, Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago.
authors: Yulia
authors: Y
authors: Komarova
authors: From the Department of Pharmacology, Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago.
authors: Masuko
authors: M
authors: Ushio-Fukai
authors: From the Department of Pharmacology, Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago. abmalik@uic.edu.
authors: Asrar B
authors: AB
authors: Malik
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D015820:Cadherins / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling; D002465:Cell Movement; D002478:Cells, Cultured; D004195:Disease Models, Animal; D017097:Electric Impedance; D042783:Endothelial Cells / Q000378:metabolism*; D006614:Hindlimb; D006801:Humans; D007511:Ischemia / Q000235:genetics / Q000378:metabolism* / Q000503:physiopathology; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018482:Muscle, Skeletal / Q000098:blood supply* / Q000378:metabolism; D009154:Mutation; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases / Q000235:genetics / Q000378:metabolism; D018919:Neovascularization, Physiologic; D010766:Phosphorylation; D016392:Proto-Oncogene Proteins pp60(c-src) / Q000235:genetics / Q000378:metabolism; D034622:RNA Interference; D017382:Reactive Oxygen Species / Q000378:metabolism*; D015398:Signal Transduction; D050053:TRPM Cation Channels / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D013997:Time Factors; D014162:Transfection; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D000099152:Cadherin 5
chemical_list: D015703:Antigens, CD; D015820:Cadherins; D002118:Calcium; D008562:Membrane Glycoproteins; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases; D016392:Proto-Oncogene Proteins pp60(c-src); D017382:Reactive Oxygen Species; D050053:TRPM Cation Channels; D042461:Vascular Endothelial Growth Factor A; D000099152:Cadherin 5; C121934:TRPM2 protein, human; C544443:TRPM2 protein, mouse; C056558:CYBB protein, human
keywords: TRPM2 protein, mouse; angiogenesis effects; cadherin 5; endothelial cells; hindlimb ischemia