title: Effect of cytokeratin 17 on retinal pigment epithelium degeneration and choroidal neovascularization.
abstract: OBJECTIVE
  To study the effects of cytokeratin 17 (CK17) on sodium iodate (NaIO3) induced rat retinal pigment epithelium (RPE) degeneration, laser induced rat choroidal neovascularization (CNV), and oxidative stress of human retinal pigment epithelium cells (ARPE-19) and human umbilical vein endothelial cell (HUVEC).
  
  
  METHODS
  Thirty 8-week-old male Brown Norway rats were randomly divided into 3 groups, 10 rats in control group treated with solvent alone; 10 rats in NaIO3 group treated with solvent and 35 mg/kg NaIO3 injection through hypoglossal vein and 10 rats in CK17+NaIO3 group treated with 1% CK17 eye drop 3 times a day for 1wk before and 4wk after NaIO3 injection. RPE function was measured with c-wave of electroretinogram (ERG). Another 20 rats were randomly divided into 2 groups. Of them 10 rats in CK17 group were anesthetized to receive Nd:YAG laser and given 1% CK17 eye drop before same as above; 10 rats in control were received Nd:YAG and treated with solvent. The development of choroidal neovascularization (CNV) was determined by fundus fluorescein angiography (FFA) performed on 4wk after laser. Methylthiazoly tetrazolium (MTT) assay was used to study effect of CK17 on various oxidants induced injury in ARPE-19 and HUVEC in vitro.
  
  
  RESULTS
  Four weeks after NaIO3 injection, the c-wave amplitude of ERG was 0.393±0.02 V in the control group, 0.184±0.018 V in NaIO3 group and 0.3±0.01 V in CK17+NaIO3 group. There was a significant reversal of the c-wave by CK17 as compared to NaIO3 group (P<0.01). Four weeks after laser, the size of the CNV lesion was 2.57±0.27 mm(2) in control group and 1.64±0.08 mm(2) in CK17 group. The lesion size significantly diminished in CK17 group (P<0.01). The in vitro results showed CK17 also reversed the various oxidants induced injuries in ARPE-19 at the dose of 100 µg/mL and enhanced the injury in HUVECs at different concentrations.
  
  
  CONCLUSIONS
  CK17 can significantly protect RPE from NaIO3 induced degeneration in vivo and in vitro and also could reverse the various oxidants induced injuries in vitro. It inhibits the development of CNV in rat model, interfered with vascular endothelial cell proliferation in vitro.
authors.affiliation: Institute of Ocular Pharmacology, College of Medicine, Texas A&M Health Science Center, College Station, TX 77843, USA.
authors.forename: Yi
authors.initials: Y
authors.lastname: Shen
authors.affiliation: Institute of Ocular Pharmacology, College of Medicine, Texas A&M Health Science Center, College Station, TX 77843, USA.
authors.forename: Pei
authors.initials: P
authors.lastname: Zhuang
authors.affiliation: Institute of Ocular Pharmacology, College of Medicine, Texas A&M Health Science Center, College Station, TX 77843, USA.
authors.forename: Tao
authors.initials: T
authors.lastname: Xiao
authors.affiliation: Institute of Ocular Pharmacology, College of Medicine, Texas A&M Health Science Center, College Station, TX 77843, USA.
authors.forename: George Cy
authors.initials: GC
authors.lastname: Chiou
keywords: age-related macular degeneration; choroidal neovascularization; cytokeratin 17; human umbilical vein endothelial cells; retinal pigment epithelium