Abstract
Purpose :
NLRP3, as an important inflammasome component, has crucial roles in age related macular degeneration (Nat Med. 2012 May 4;18(5):658-60.). MicroRNAs (miRNAs) have been implicated as important regulators of retinal para-inflammation. This study aimed to identify the role of microRNA-22-3p (miR-22-3p) in retinal pigment epithelial (RPE) oxidative damage by targeting NLRP3 through the inflammasome signaling pathway.
Methods :
The potential miRNAs targeting NLRP3 were predicted based on TargetScan, miRDB, miRTarBase, and miRWalk databases. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to analyze the change of ten candidate miRNAs in retinas from albino mice after 5000 lux blue light expose. NLRP3 related protein expression was measured using qRT-PCR and Western blotting. In in-vitro studies, cell viability, ROS level, apoptosis, and NLRP3-related protein expression was measured in RPE group (Vehicle), or miRNA knockout group (KO), or miRNA mimics group (MIM), underwent lipopolysaccharide and rotenone stimulation.
Results :
After light exposure, NLRP3, caspase-1, IL-1β were significantly up-regulated in mice retinas. Of 10 potential miRNAs, miRNA-22-3p was found significantly decreased. In-vitro, after 10 ug/mL LPS and 2.5 uM rotenone stimulation, ROS level were upregulated, NLRP3 inflammasome activated, and IL-1β increasingly secreted. However, we found ROS level, NLRP3 inflammasome, and IL-1β were up-regulated in miRNA-22-3p KO group while down-regulated in miRNA-22-3p MIM group.
Conclusions :
Our research describes a mechanism by which miR-22-3p suppresses NLRP3 and maintains homeostasis of RPE cells and suggests miR-22-3p as a potential target for the intervention of RPE damage.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.