Blue light damaged-retinal pigment epithelial cell derived-exosomes activate nod-like receptor protein inflammasome / 中华眼底病杂志

ABSTRACT

Objective To observe the effect of exosomes secreted by retinal pigment epithelial (RPE) cells which damaged by blue light to Nod-like receptor protein (NLRP3). Methods Cultured 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). Results Blue 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). Conclusion The expression IL-1β, IL-18 and caspase-1 and NLRP3 mRNA were upregulated by exosomes secreted by blue light damaged-RPE cells.