TNFAIP3 may be key to TLR4-activation of the inflammasome in the retinal vasculature.

The goal of these studies were to determine whether tumor necrosis factor, alpha-induced protein 3 (TNFAIP3) regulated toll-like receptor 4 (TLR4) actions on the NOD-like receptor protein 3 (NLRP3) inflammasome. Western blotting was done on retinal lysates from TLR4 floxed and endothelial cell specific TLR4 knockout mice for TNFAIP3, TLR4, and NLRP3 pathway proteins. Retinal endothelial cells (REC) were grown in normal (5 mM) and high glucose (25 mM) and treated with TNFAIP3 siRNA, followed by Western blotting for TLR4 and NLRP3 pathway proteins. Loss of TLR4 in endothelial cells increased TNFAIP3 levels, while decreasing NLRP3 pathway proteins. High glucose culturing conditions increased TLR4 and NLRP3 proteins, which were also increased by TNFAIP3 siRNA. Data demonstrate that TLR4 regulates NLRP3 pathway proteins. TNFAIP3 can regulate TLR4 and the NLRP3 pathway. TNFAIP3 may offer a new target for therapeutic development against retinal inflammation.