ObjectiveTo observe the effect of exosomes secreted by retinal pigment epithelial (RPE) cells which damaged by blue light to Nod-like receptor protein (NLRP3).MethodsCultured ARPE-19 cells were divided into 2 groups; one group of RPE cells were exposed to blue light irradiation for 6 hours, the other group was cultured in routine environment. Total exosomes were extracted from the two groups by differential ultracentrifugation in low-temperature, and examined by transmission electron microscope to identify their forms. The exosomes were then incubated with normal ARPE-19 cells. The expression level of CD63, interleukin (IL)-1β, IL-18 and caspase-1 on the exosome surface were measured by Western blotting. The expressions of NLRP3 mRNA in RPE cells were detected by real-time fluorescence quantitative reverse transcription polymerase chain reaction (RT-PCR).ResultsBlue light damaged the cellular morphology. Transmission electron microscopy showed that the exosomes were 50-200nm in diameter and like double-concave disks. Blue light damaged cell-derived exosomes had significantly higher expression of IL-1β (t=18.04), IL-18 (t=12.55) and caspase-1 (t=14.70) than the control group (P＜0.001). ARPE-19 cells cultured with blue light damaged cell-derived exosomes also had significantly higher expression of IL-1β (t=18.59), IL-18 (t=23.95) and caspase-1 (t=35.27) than control exosomes (P＜0.001). RT-PCR showed that the relative expression of NLRP3 mRNA of PRE cells in experimental group and control group were 1.000±0.069 and 0.2±0.01, respectively, the difference was significant (t=12.20, P＜0.001).ConclusionThe expression IL-1β, IL-18 and caspase-1 and NLRP3 mRNA were upregulated by exosomes secreted by blue light damaged-RPE cells.
Objective To investigate the effect of arginase (Arg) inhibitor N-ω-Hydroxy-L nor-Arginine (nor-NOHA) on high glucose cultured rhesus macaque retinal vascular endothelial cell line (RF/6A) in vitro. Methods The RF/6A cells were divided into the following 4 groups: normal control group (5.0 mmol/L of glucose, group A), high glucose group (25.0 mmol/L, group B), high glucose with 125 mg/L nor-NOHA group (group C), and high glucose with 1% DMSO group (group D). The proliferation, migration ability and angiogenic ability of RF/6A cells were measured by Methyl thiazolyl tetrazolium (MTT), transwell chamber and tube assay respectively. The express of Arg I, eNOS, iNOS mRNA of RF/6A cells were measured by real-time polymerase chain reaction (RT-PCR), Enzyme-linked immuno sorbent assay (ELISA) was used to detect the expression of NO and interleukine (IL)-1b of RF/6A cells. Results The proliferation, migration, and tube formation ability of group A (t=2.367, 5.633, 7.045;P＜0.05) and group C (t=5.260, 6.952, 8.875;P＜0.05) were significantly higher than group B. RT-PCR results showed the Arg I and iNOS expression in group B was higher than that in group A (t=6.836, 3.342;P＜0.05) and group C (t=4.904, 7.192;P＜0.05). The eNOS expression in group B was lower than that in group A and group C (t=4.165, 6.594;P＜0.05). ELISA results showed NO expression in group B was lower than that in group A and group C (t=4.925, 5.368;P＜0.05). IL-1b expression in group B was higher than that in group A and group C (t=5.032, 7.792;P＜0.05). Conclusions Nor-NOHA has a protective effect on cultured RF/6A cells in vitro and can enhance its proliferation, migration and tube formation. The mechanism may be inhibiting the oxidative stress by balancing the expression of Arg/NOS.