title: Angiogenin ameliorates corneal opacity and neovascularization via regulating immune response in corneal fibroblasts.
abstract: BACKGROUND
  Angiogenin (ANG), a component of tears, is involved in the innate immune system and is related with inflammatory disease. We investigated whether ANG has an immune modulatory function in human corneal fibroblasts (HCFs).
  
  
  METHODS
  HCFs were cultured from excised corneal tissues. The gene or protein expression levels of interleukin (IL)-1beta (β), IL-4, IL-6, IL-8, IL-10, complements, toll-like receptor (TLR)4, myeloid differentiation primary response gene (MYD)88, TANK-binding kinase (TBK)1, IkappaB kinase-epsilon (IKK-ε) and nuclear factor-kappaB (NF-κB) were analyzed with or without ANG treatment in tumor necrosis factor-alpha (TNF-α)- or lipopolysaccharide (LPS)-induced inflammatory HCFs by real-time polymerase chain reaction (PCR), Western blotting and immunocytochemistry. Inflammatory cytokine profiles with or without ANG were evaluated through immunodot blot analysis in inflammatory HCFs. Corneal neovascularization and opacity in a rat model of corneal alkali burn were evaluated after application of ANG eye drops.
  
  
  RESULTS
  ANG decreased the mRNA levels of IL-1β, IL-6, IL-8, TNF-α receptor (TNFR)1, 2, TLR4, MYD88, and complement components except for C1r and C1s and elevated the mRNA expression of IL-4 and IL-10. Increased signal intensity of IL-6, IL-8 and monocyte chemotactic protein (MCP)-1 and MCP-2 induced by TNF-α or LPS was weakened by ANG treatment. ANG reduced the protein levels of IKK-ε by either TNF-α and LPS, and decreased TBK1 production induced by TNF-α, but not induced by LPS. The expression of NF-κB in the nuclei was decreased after ANG treatment. ANG application lowered corneal neovascularization and opacity in rats compared to controls.
  
  
  CONCLUSIONS
  These results demonstrate that ANG reduces the inflammatory response induced by TNF-α or LPS in HCFs through common suppression of IKK-ε-mediated activation of NF-κB. This may support the targeting of immune-mediated corneal inflammation by using ANG.
authors.affiliation: Department of Ophthalmology, College of Medicine, Chung-Ang University Hospital, 224-1, Heukseok-dong, Dongjak-Gu, Seoul, 156-755, Republic of Korea.|Graduate School of Chung-Ang University, College of Medicine, Seoul, Republic of Korea.
authors.forename: Seung Hoon
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Department of Ophthalmology, College of Medicine, Chung-Ang University Hospital, 224-1, Heukseok-dong, Dongjak-Gu, Seoul, 156-755, Republic of Korea.|Graduate School of Chung-Ang University, College of Medicine, Seoul, Republic of Korea.
authors.forename: Kyoung Woo
authors.initials: KW
authors.lastname: Kim
authors.affiliation: Department of Ophthalmology, College of Medicine, Chung-Ang University Hospital, 224-1, Heukseok-dong, Dongjak-Gu, Seoul, 156-755, Republic of Korea.|Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 305-701, Republic of Korea.
authors.forename: Kwangsic
authors.initials: K
authors.lastname: Joo
authors.affiliation: Department of Ophthalmology, College of Medicine, Chung-Ang University Hospital, 224-1, Heukseok-dong, Dongjak-Gu, Seoul, 156-755, Republic of Korea. jck50ey@daum.net.
authors.forename: Jae Chan
authors.initials: JC
authors.lastname: Kim
mesh_terms: D043925:Angiogenesis Inducing Agents / Q000494:pharmacology*; D000818:Animals; D015153:Blotting, Western; D002057:Burns, Chemical / Q000188:drug therapy / Q000276:immunology; D018925:Chemokines / Q000378:metabolism; D003315:Cornea / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D016510:Corneal Neovascularization / Q000188:drug therapy* / Q000276:immunology*; D003318:Corneal Opacity / Q000188:drug therapy* / Q000276:immunology*; D016207:Cytokines / Q000378:metabolism; D004195:Disease Models, Animal; D005126:Eye Burns / Q000188:drug therapy / Q000276:immunology; D005347:Fibroblasts / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D007113:Immunity, Innate / Q000187:drug effects*; D007150:Immunohistochemistry; D007378:Interleukins / Q000378:metabolism; D008297:Male; D016133:Polymerase Chain Reaction / Q000379:methods; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012259:Ribonuclease, Pancreatic / Q000494:pharmacology*
chemical_list: D043925:Angiogenesis Inducing Agents; D018925:Chemokines; D016207:Cytokines; D007378:Interleukins; D012333:RNA, Messenger; C046366:angiogenin; D012259:Ribonuclease, Pancreatic
keywords: Angiogenin; Inflammation,IKK-ε