Positive Health Online

Abstract

LI and COLLEAGUES, (1)Center for Experimental Therapeutics and Reperfusion Injury, Harvard Institutes of Medicine, Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA studied the role of specialized proresolving mediators (SPMs; resolvins and maresins) and microRNAs (miRNAs) in modulation of acute inflammation.

Background

The magnitude and duration of acute inflammation are controlled by active resolution programs involving specialized proresolving mediators (SPMs; resolvins and maresins) and microRNAs (miRNAs).

Methodology

Here, we report that miR-466l was temporally regulated in murine exudate-infiltrating leukocytes. Neutrophil miR-466l overexpression in vivo promoted initiation of inflammation that anteceded macrophage expression of this miRNA, which accelerated resolution when overexpressed.

Results

In macrophages, miR-466l overexpression increased prostanoids and SPMs (e.g., resolvin D1 [RvD1] and RvD5), which enhanced resolution. RvD1, RvD2, maresin 1 (MaR1), and apoptotic neutrophils reduced miR-466l expression within human macrophages, a feedback regulation that most likely prepares for homeostasis. miR-466l was upregulated in peripheral blood of sepsis patients, and its increase correlated with nonsurvival from sepsis. SPMs and miR-466l regulated transcription factors activator protein 1 and nuclear factor κB1 in miRNA biogenesis.

Conclusion

These results demonstrate pivotal roles for SPMs and miR-466l in dynamic leukocyte plasticity during resolution of acute inflammatory responses.

References

Li Y(1), Dalli J, Chiang N, Baron RM, Quintana C, Serhan CN. Plasticity of leukocytic exudates in resolving acute inflammation is regulated by MicroRNA and proresolving mediators.  Immunity. 39(5):885-98. doi: 10.1016/j.immuni.2013.10.011.  Nov 14 2013. Comment in Immunity. 39(5):801-2. Nov 14 2013.