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.
Objective To build the lentiviral vectors of pigment epithelial derived factor (PEDF) gene, and investigate their expression in human umbilical cord mesenchymal stem cells (hUCMSCs). Methods The PEDF lentiviral vectors (LV-PEDF) were built by DNA recombination and confirmed by DNA sequencing. hUCMSCs were transfected by LV-PEDF with MOI 10, 30, 50, respectively. The transfection efficiency was observed under fluorescence microscope. Cell immunofluorescence, immunocytochemistry and real-time PCR methods were used for detecting the expression of PEDF and VEGF. Results The PEDF cDNA was sub-cloned into pCDH-CMV-MCS-EF1-copGFP vector successfully. DNA sequencing analysis confirmed that PEDF gene sequence was exactly the same with that reported in GenBank. pCDH-PEDF infected cells could show green fluorescence under fluorescence microscope. The transfection efficiency was 72.1% in PEDF-MSCs. Immunofluorescence and immunochemical staining confirmed that PEDF protein was overexpressed in hUCMSCs. The relative expression of PEDF mRNA in experimental group and control group was (0.170±0.028) and (0.015±0.007) respectively by RT-PCR, the difference was statistically significant (P＜0.001). The relative expression levels of VEGF mRNA in the two groups were (0.265±0.022) and (0.285±0.049), respectively, with no significant difference (P＞0.05). Conclusions We successfully built a lentivirus vector carrying PEDF gene and obtained hUCMSCs with overexpressed PEDF.