title: NF-κB mediates the survival of corneal myofibroblast induced by angiotensin II.
abstract: OBJECTIVE
  To investigate the role of angiotensin II (Ang II) in the regulation of corneal myofibroblast apoptosis and the possible signaling pathway.
  
  
  METHODS
  Rabbit corneal myofibroblasts were cultured in vitro and the cell phenotype was identified by expression of α-smooth muscle actin (α-SMA) and formation of F-actin. The expression of Ang II type I receptor (AT1R) in keratocytes and corneal myofibroblasts were detected by immunofluorescence staining and Western blot. The effect of Ang II on corneal myofibroblast apoptosis induced by serum starvation and TNFα plus cycloheximide (CHX) was examined by TUNEL, Hoechst 33258 staining, and caspase 3/7 activity assay. The effect of Ang II on nuclear factor-κB (NF-κB)-dependent DNA binding activity and transcriptional activity was studied by electrophoresis mobility shift assay (EMSA) and luciferase reporter assay, respectively. Ang II-induced TGFβ1 secretion by corneal myofibroblasts was determined by ELISA.
  
  
  RESULTS
  Ang II type I receptor expression was more abundant in corneal myofibroblasts compared with keratocytes. Ang II reduced corneal myofibroblasts apoptotic response to serum starvation or treatment with TNFα plus CHX. This protective effect was attenuated in the presence of AT1R antagonist losartan or NF-κB-specific inhibitor Bay11-7082. Ang II increased NF-κB-dependent DNA-binding activity and transcriptional activity, and also increased TGFβ1 production by corneal myofibroblasts.
  
  
  CONCLUSIONS
  Ang II induces corneal myofibroblasts resistance to apoptosis via activating NF-κB signaling pathway, and thus should be further investigated as a possible target for therapy of corneal fibrosis.
authors.affiliation: Institute of Ophthalmology, School of Medicine, Jinan University, Guangzhou, China.
authors.forename: Hong-Wei
authors.initials: HW
authors.lastname: Pan
authors.affiliation: Department of Histology and Embryology, Guangzhou Medical University, Guangzhou, China.
authors.forename: Yu-Hong
authors.initials: YH
authors.lastname: Cui
authors.affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Jun-Wen
authors.initials: JW
authors.lastname: Zeng
mesh_terms: D000818:Animals; D017209:Apoptosis; D015153:Blotting, Western; D002470:Cell Survival; D002478:Cells, Cultured; D003316:Corneal Diseases / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D003319:Corneal Stroma / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D004247:DNA / Q000235:genetics*; D004195:Disease Models, Animal; D004797:Enzyme-Linked Immunosorbent Assay; D005355:Fibrosis / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D005786:Gene Expression Regulation; D020287:In Situ Nick-End Labeling; D058628:Myofibroblasts / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D016328:NF-kappa B / Q000494:pharmacology*; D011817:Rabbits; D044139:Receptor, Angiotensin, Type 2 / Q000096:biosynthesis / Q000235:genetics*; D015398:Signal Transduction
chemical_list: D016328:NF-kappa B; D044139:Receptor, Angiotensin, Type 2; D004247:DNA
keywords: NF-κB; angiotensin II; apoptosis; corneal fibrosis; corneal myofibroblasts