Effect Of Light Emitting Diode On The Expression Of NF-?B?MCP-1 And IL-8 In Cultured Human Retinal Pigment Epithelial Cells

Objective To observe the effect of light emitting diode(LED) on the expression of NF-?B?MCP-1 and IL-8 in cultured human retinal pigment epithelial cells.Methods Cultured human RPE-19 cells divided into LED white light, blue light, green light and control group. The illumination was 300lux?500lux and 1000 lux. The cells were exposed for 6,12 18 and 24 hours respectively. While the control groups were cultured without light exposure. The growth and proliferation were assessed using MTT as absorbance(A460). The levels of NF-?B?IL-8 protein expression were observed by immunocytochemistry(ICC) after 1000 lux 6h?12h?24h white,blue and green light illumination.The relative expression of m RNA and protein of NF-?B? MCP-1 and IL-8 in the cells were assayed by real-time PCR and Enzyme linked immunosorbent assay(ELISA),respectively.Results 1.The A460 values of the groups exposed to white light and blue light were significant difference(all P<0.05),while the green groups had no statistical significant difference(P>0.05). The proliferation of RPE cells were significant difference after exposed to white light 300 lux 24h,500 lux 18h?24h,1000 lux 12h?18h?24h,blue light 300 lux 18h?24h,500 lux and 1000 lux 6h?12h?18h?24h compared with the controls(P<0.05).The A460 values of the cells exposed to white light and blue light had a tendency to increase gradually along with illumination intensity and exposure time. 2.ICC showed the effect of LED light on the expression of NF-?B and IL-8 were in cytoplasm, and the cells exposed to blue light had a higher expression than white and green light. 3.RT-PCR revealed the considerable difference about expression of NF-?B m RNA in RPE cells among these groups(all P<0.05).The relative expression of NF-?B m RNA in white light 300 lux 18h?24h,500 lux 18h?24h?1000lux 12h?18h?24h, blue light 300 lux 12h?18h?24h,500 lux 12h?18h?24h,1000 lux 6h?12h?18h?24h and green light 300 lux 24h?500lux 24h?1000lux 18h?24h showed statistical significant difference compared with the controls(P<0.05). The expression of MCP-1?IL-8 m RNA in RPE cells of green light had no statistical significant difference(P>0.05). White light 300lux?500lux?1000lux and green light 500lux?1000lux were significant difference in expression of MCP-1?IL-8 m RNA(P<0.05). The expression of MCP-1?IL-8 m RNA of RPE cells exposed to white light 500 lux 24h?1000lux 12h?18h?24h,blue light 300 lux 18h?24h,500 lux 12h?18h?24h,1000lux12h?18h?24h,and green light 500 lux 24h?1000lux 24 h had statistical significant difference compared with the controls(P<0.05). 4.ELISA showed that the concentrations of NF-?B? MCP-1 and IL-8 in RPE cells of all the groups were significant difference(P<0.05). The concentrations of NF-?B in white light 300 lux 18h?24h,500 lux 18h?24h,1000 lux 12h?18h?24h,blue light 300 lux 12h? 18h?24h,500 lux 12h?18h?24h,1000 lux 6h?12h?18h?24h and green light 300 lux 24 h,500 lux 24h?1000 lux 18h?24h increased significantly(all P<0.05),and reach the top when exposure time was up to 24 hours. Compared to the control groups, the concentrations of MCP-1 and IL-8 had significant difference after white light 300 lux 18h?24h,500 lux 18h?24h?1000lux 12h?18h?24h,blue light 300 lux 18h?24h,500 lux 12h?18h?24h?1000lux 12h?18h?24h and green light 500 lux 24h?1000lux 24 h exposure(all P<0.05).Conclusions Exposure to white and blue light could effect the growth and proliferation in cultured human retinal pigment epithelial cells. White?blue light and green light increased the concentrations of NF-?B?MCP-1 and IL-8 in RPE cells in a illumination intensity and exposure time dependent way, and the effect was more obvious after exposure to blue light.