ABSTRACT
AIM:To investigate whether ceramide kinase-like protein(CERKL)alleviates oxidative stress injury of retinal pigment epithelial(RPE)cells induced by blue light via activating the silent information regulator 1(SIRT1)/E2F transcription factor 1(E2F1)axis. METHODS:Cultured human retinal pigment epithelial-19(ARPE-19)cells were irradiated with blue light to observe the morphological changes, and the expression of CERKL was detected by PCR and Western blot. ARPE-19 cells were transfected with siRNA-CERKL and pcDNA3.1-CERKL respectively. After exposure to blue light, cell viability was determined by MTT assay, apoptosis was detected by TUNEL assay, content of oxidative stress markers and the expression of SIRT1/E2F1 axis was analyzed. Then siRNA-SIRT1 was transfected into ARPE-19 cells, and the oxidative stress damage of ARPE-19 cells under blue light irradiation was detected again.RESULTS:ARPE-19 cells gradually contracted into spheres and appeared vacuoles after exposure to blue light. Blue light irradiation led to the increase of CERKL expression level(P<0.05), meanwhile, the rate of cell viability was decreased(P<0.05), the rate of the apoptosis was increased(P<0.05), contents of reactive oxygen species, malondialdehyde and 8-hydroxydeoxyguanosine were increased(P<0.05). Silence of CERKL aggravated this phenomenon, while up-regulation of CERKL could alleviate this change(P<0.05). Up-regulation of CERKL also activated the expression of SIRT1 and promoted the deacetylation of E2F1(P<0.05). Silencing SIRT1 could reverse the alleviating effect of up-regulating CERKL on oxidative stress injury of ARPE-19 cells induced by blue light(P<0.05). CONCLUSION: CERKL can reduce oxidative stress damage of ARPE-19 cells induced by blue light via activating SIRT1 expression and promoting the deacetylation of E2F1.
ABSTRACT
AlM:To investigate the protective effect of astaxanthin (AST) on human retinal pigment epithelial (RPE) cells against oxidative damage induced by hydrogen peroxide (H2O2).METHODS:Human RPE cells were subcultured, cell activity was detected by MTT, rate of apoptosis was detected by flow cytometry and cell ultrastructure changes were observed under transmission electron microscope. RESULTS: MTT results showed that cell activity elevated to ( 53. 66%± 3. 25% and 70. 43%± 2. 38% after 10-8 mol/L and 10-4 mol/L AST treated. The difference had statistically significant (P<0. 05) compared with oxidative injury group (38. 76%± 3. 74%). Flow cytometry results showed that the apoptosis rate of RPE cells decreased to 30. 23%± 1. 91% and 12. 58%± 2. 12% in AST pretreated group, the difference was significant (P<0. 05) compared with oxidative injury group ( 42. 50%± 1. 94%); Electron microscopy showed that the morphology of cells gradually improved accompanied with the concentration of AST elevated.CONCLUSlON:AST may inhibit hydrogen peroxide-induced apoptosis of RPE cells, it can provide reliable evidence for pursue effective medicine to prevent and treat retina injury.