title: Mechanism for laser-induced neovascularization in rat choroid: accumulation of integrin α chain-positive cells and their ligands.
abstract: OBJECTIVE
  Inhibitors binding to integrins α5 and αv are antiangiogenic in models of choroidal neovascularization (CNV). However, a comprehensive understanding of the accumulation of integrin α isoform-positive cells, their ligands, and associations is limited. The purpose of the present study was to examine the localization of integrin α chain-positive cells and their extracellular matrix (ECM) ligands in the RPE/choroid after laser injury.
  
  
  METHODS
  CNV, observed with fluorescein isothiocyanate (FITC)-labeled isolectin, was produced in Brown Norway rats with a 532 nm green laser. Localization of α5 and αv integrins and their ligands was performed with immunohistochemistry in consecutive cryosections. To test the binding specificity between the integrin α chains and ECM ligands, an in vitro cell adhesion assay was performed using retinal endothelial cells and specific antibodies.
  
  
  RESULTS
  Angiogenesis was observed on day 7 after laser injury in choroidal flat mounts and cryosections. The number of integrin α5- and αv-positive cells markedly increased at day 3 and then gradually decreased, but was still elevated on day 14. One day after laser treatment, α integrin ligands fibronectin (FN) and vitronectin (VN) were markedly increased, and localized closely to integrins in the laser-injured regions. FN decreased on day 7, but was still retained until 14 days. In contrast, VN disappeared. Cell adhesion assays showed specific association of integrin α5 to FN, and integrin αv to VN.
  
  
  CONCLUSIONS
  Laser-induced choroidal injury increased FN and VN, followed by accumulation of integrin α5- and αv-positive cells. The interaction between integrin α chain-positive cells and their specific ligands FN and VN may be important steps leading to CNV.
authors: Senju Laboratory of Ocular Sciences, Senju Pharmaceutical Co., Ltd., Kobe, Japan.
authors: Takeshi
authors: T
authors: Nakajima
authors: Senju Laboratory of Ocular Sciences, Senju Pharmaceutical Co., Ltd.,Portland, OR ; Department of Integrative Biosciences, Oregon Health & Science University, Portland, OR.
authors: Masayuki
authors: M
authors: Hirata
authors: Department of Integrative Biosciences, Oregon Health & Science University, Portland, OR.
authors: Thomas R
authors: TR
authors: Shearer
authors: Senju Laboratory of Ocular Sciences, Senju Pharmaceutical Co., Ltd., Kobe, Japan ; Senju Laboratory of Ocular Sciences, Senju Pharmaceutical Co., Ltd.,Portland, OR ; Department of Integrative Biosciences, Oregon Health & Science University, Portland, OR.
authors: Mitsuyoshi
authors: M
authors: Azuma
mesh_terms: D000818:Animals; D002448:Cell Adhesion; D002829:Choroid / Q000378:metabolism* / Q000473:pathology*; D020256:Choroidal Neovascularization / Q000378:metabolism* / Q000473:pathology*; D042783:Endothelial Cells / Q000378:metabolism / Q000473:pathology; D005109:Extracellular Matrix / Q000378:metabolism; D005353:Fibronectins / Q000378:metabolism; D039482:Integrin alpha5 / Q000378:metabolism*; D039564:Integrin alphaV / Q000378:metabolism*; D007834:Lasers; D008024:Ligands; D008264:Macrophages / Q000378:metabolism / Q000473:pathology; D008297:Male; D017628:Microglia / Q000378:metabolism / Q000473:pathology; D011485:Protein Binding; D021122:Protein Subunits / Q000378:metabolism; D051381:Rats; D011914:Rats, Inbred BN; D012160:Retina / Q000473:pathology; D019096:Vitronectin / Q000378:metabolism
chemical_list: D005353:Fibronectins; D039482:Integrin alpha5; D039564:Integrin alphaV; D008024:Ligands; D021122:Protein Subunits; D019096:Vitronectin