Expression of vascular endothelial growth factor A and its receptors in light-injured human retinal pigment epithelial cells

Objective To observe the expression of vascular endothelial growth factor A (VEGF-A) and its receptors sFlt-1,kinase insert domain receptor (KDR) in light-injured human retinal pigment epithelial (RPE) cells.Methods Cultured human RPE cells (8th - 12th generations) were divided into normal control group and light damage group.The cells of two groups were exposed to the 18 W cold white light (2200±300) Lux for 12 hours to induce light damage responses,but the cells of normal control group were packed by tinfoil with double-deck high pressure disinfection.The VEGF-A,sFlt-1 and KDR mRNA and protein expressions were detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot at 0,6,12,24 hours after light damage. Results The VEGF-A mRNA and protein expressions in light damage group were significantly increased at 6 hours,and reached its peak at 12 hours after light damage which obviously higher than that in normal group (t=2.74,2.93; P＜0.05),and then went down gradually.The sFlt-1 mRNA and protein expressions in light damage group reached its peak at 12 hours after light damage which obviously higher than that in normal group (t=4.32,P＜0.01),but obviously lower than that in normal group at 24 hours after light damage (t=2.41,P＜0.05).The KDR mRNA and protein expressions in light damage group were obviously higher than that in normal group at 24hours after light damage (t=2.89,P＜0.05),but there was no changes at 6,12 hours after light damage (t=l.84,P＞0.05).Conclusions At 6,12 hours after light damage,the expressions of VEGF-A and sFlt-1 increases significantly and KDR expression is stable in light-injured RPE cells.At 24 hours after light damage,the expression of VEGF-A and sFlt-1 decreases,but KDR expression increases in light-injured RPE cells. Key words: Pigment epithelium of eye/pathophysiology; Vascular endothelial growth factor A/analysis; Receptors,vascular endothelial growth factor; Photic stimulation/adverse effects