Resolvin D1 inhibits multiple pro-inflammatory signaling pathways in primary human lung cells exposed to diverse inflammatory stimuli (IRM9P.721)

Abstract

Abstract Resolution of inflammation is a bioactive process involving a new genus of lipid molecules called “specialized pro-resolving lipid mediators” (SPMs), mainly derived from dietary ω-3 polyunsaturated fatty acids, which actively antagonize inflammatory signaling pathways and promote resolution. Although it is broadly known that SPMs inhibit inflammation, the specific pathways and targets of many SPMs remained to be discovered. Here, we investigated the mechanism by which the SPM resolvin D1 (RvD1) inhibits pro-inflammatory signaling pathways using two distinct stimuli; IL-1β, which acts primarily via its own receptor, and poly(I:C), a double-stranded viral RNA mimetic that acts primarily through toll-like receptor (TLR)3. RvD1 inhibited production of pro-inflammatory mediators including IL-6 and IL-8, both primary human lung fibroblast and epithelial cell strains, when stimulated with either IL-1β or poly(I:C). RvD1 also blocked phosphorylation of ERK1/2 and translocation of NF-κB p65 in cells treated with both stimuli. Importantly, we found that RvD1 inhibited phosphorylation of TAK1, an upstream effector protein that regulates both the MAP-kinase and NF-κB pathways. These results demonstrate that RvD1 targets multiple pro-inflammatory signaling pathways and may have significant therapeutic potential in complex inflammatory diseases including pulmonary fibrosis, asthma and chronic obstructive pulmonary disease.