Effect of cytokeratin 17 on retinal pigment epithelium degeneration and choroidal neovascularization

AIM:To study the effects of cytokeratin 17（CK17） on sodium iodate（NalO;） 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 NalO;group treated with solvent and 35 mg/kg NalO;injection through hypoglossal vein and 10 rats in CK17+NalO;group treated with 1%CK17 eye drop 3 times a day for1 wk before and 4wk after NalO;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 NalO;injection,the cwave amplitude of ERG was 0.393±0.02 V in the control group,0.184 ±0.018 V in NalO;group and 0.3±0.01 V in CK17+NalO;group.There was a significant reversal of the c-wave by CK17 as compared to NalO;group（P<0.01）.Four weeks after laser,the size of the CNV lesion was2.57±0.27 mm;in control group and 1.64±0.08 mm;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.CONCLUSION:CK17 can significantly protect RPE from NalO;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.