[HTML][HTML] Self-limited versus delayed resolution of acute inflammation: temporal regulation of pro-resolving mediators and microRNA

G Fredman, Y Li, J Dalli, N Chiang, CN Serhan - Scientific reports, 2012 - nature.com
Scientific reports, 2012nature.com
Mechanisms underlying delays in resolution programs of inflammation are of interest for
many diseases. Here, we addressed delayed resolution of inflammation and identified
specific microRNA (miR)-metabolipidomic signatures. Delayed resolution initiated by high-
dose challenges decreased miR-219-5p expression along with increased leukotriene B4 (5-
fold) and decreased (~ 3-fold) specialized pro-resolving mediators, eg protectin D1.
Resolvin (Rv) E1 and RvD1 (1 nM) reduced miR-219-5p in human macrophages, not shared …
Abstract
Mechanisms underlying delays in resolution programs of inflammation are of interest for many diseases. Here, we addressed delayed resolution of inflammation and identified specific microRNA (miR)-metabolipidomic signatures. Delayed resolution initiated by high-dose challenges decreased miR-219-5p expression along with increased leukotriene B4 (5-fold) and decreased (~3-fold) specialized pro-resolving mediators, e.g. protectin D1. Resolvin (Rv)E1 and RvD1 (1 nM) reduced miR-219-5p in human macrophages, not shared by RvD2 or PD1. Since mature miR-219-5p is produced from pre-miRs miR-219-1 and miR-219-2, we co-expressed in human macrophages a 5-lipoxygenase (LOX) 3′UTR-luciferase reporter vector together with either miR-219-1 or miR-219-2. Only miR-219-2 reduced luciferase activity. Apoptotic neutrophils administered into inflamed exudates in vivo increased miR-219-2-3p expression and PD1/NPD1 levels as well as decreased leukotriene B4. These results demonstrate that delayed resolution undermines endogenous resolution programs, altering miR-219-2 expression, increasing pro-inflammatory mediators and compromising SPM production that contribute to failed catabasis and homeostasis.
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