Abstract
Purpose :
To investigate whether miR15a regulates NLR family pyrin domain containing 3 (NLRP3) inflammasome actions in mice retinal vasculature and human retinal endothelial cells (REC).
Methods :
Whole retinal lysates from both miR15a overexpressing mice and endothelial cell specific miR15a knockout mice were used to investigate protein levels of Forkhead box protein O1 (Foxo1), NLRP3, interleukin 1 beta (IL-1ß), and cleaved caspase 1. Primary human REC were cultured in normal and high glucose followed by transfection with a miR15a mimic or a recombinant human Foxo1 (rhFoxo1) agonist for protein analyses of Foxo1, NLRP3, IL-1ß, and cleaved caspase 1. miR15a expression was verified by quantitative PCR. A luciferase binding assay was used to examine whether miR15a directly binds Foxo1.
Results :
miR15a directly binds to Foxo1. In mouse retinal lysates, loss of miR15a led to an increase in Foxo1, NLRP3, IL-1ß levels, as well as cleavage of caspase 1. REC grown in high glucose transfected with the miR15a mimic had decreased levels of Foxo1, NLRP3, IL-1ß, and cleaved caspase 1. Treatment with rhFoxo1 of REC cultured in high glucose had increased levels of NLRP3, IL-1ß, and cleaved caspase 1.
Conclusions :
miR15a regulates NLRP3 actions in the retinal vasculature. Work in mice showed that loss of miR15a increased NLRP3 pathway signaling. miR15a mimics decreased levels of NLRP3, Foxo1, IL-1ß, and cleaved caspase 1 in REC grown in high glucose. Taken together, miR15a may reduce inflammasome actions in the retinal vasculature through reductions in Foxo1.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.