Figure 3. The effect of P58^IPK on gene expression of ATF4, C/EBP homologous protein, GRP78, and vascular endothelial growth factor on human retinal capillary endothelial cells by real time PCR. A: Evaluation the effect of P58^IPK on gene expression of ATF4 on human retinal capillary endothelial cells (HRCECs) treated with tunicamycin by real time PCR. Group 1 is normal control that was not endoplasmic reticulum (ER)-stressed. Group 2 is HRCECs treated with tunicamycin. Group 3 is HRCECs transfected with rAAV2-P58^IPK, and treated with tunicamycin. Group 4 is HRCECs transfected with pGIPZ-P58^IPK RNAi and treated with tunicamycin. The expression level of ATF4 in either group was: 0.52±0.05, 1.14±0.05, 0.58±0.06, and 1.54±0.06 (p< 0.001), respectively. B: Evaluation the effect of P58^IPK on gene expression of GRP78 on HRCECs treated with tunicamycin by real time PCR: Group 1 represents normal control that was not ER-stressed. Group 2 represents HRCECs treated with tunicamycin. Group 3 represents HRCECs transfected with rAAV2-P58^IPK and treated with tunicamycin. Group 4 represents HRCECs transfected with pGIPZ-P58^IPK RNAi and treated with tunicamycin. The expression level of GRP78 in either group was: 1.13±0.08, 1.96±0.14, 1.09 ±0.13, and 2.44±0.16 (p< 0.001), respectively. C: Evaluation the effect of P58^IPK on gene expression of C/EBP homologous protein (CHOP) on HRCECs treated with tunicamycin by real time PCR. Group 1 is normal control that was not ER-stressed. Group 2 is HRCECs treated with tunicamycin. Group 3 is HRCECs transfected with rAAV2-P58^IPK and treated with tunicamycin. Group 4 is HRCECs transfected with pGIPZ-P58^IPK RNAi and treated with tunicamycin. The expression level of CHOP in either group was: 0.35±0.02, 0.61±0.03, 0.39±0.04, and 0.83±0.06 (p< 0.001), respectively. D: Evaluation the effect of P58^IPK on gene expression of vascular endothelial growth factor (VEGF) on HRCECs treated with tunicamycin by real time PCR. Group 1 represents normal control that was not ER-stressed. Group 2 represents HRCECs treated with tunicamycin. Group 3 represents HRCECs transfected with rAAV2-P58^IPK and treated with tunicamycin. Group 4 represents HRCECs transfected with pGIPZ-P58^IPK RNAi and treated with tunicamycin. The expression level of VEGF in either group was: 1.02±0.07, 1.61±0.04, 1.02 ±0.07, and 2.14±0.12 (p< 0.001), respectively.