Anti-Inflammatory and Proresolving Effects of the Omega-6 Polyunsaturated Fatty Acid Adrenic Acid.
THE JOURNAL OF IMMUNOLOGY 2020;
205:2840-2849. [PMID:
33008950 DOI:
10.4049/jimmunol.1801653]
[Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 09/07/2020] [Indexed: 12/31/2022]
Abstract
Polyunsaturated fatty acids (PUFAs) and their metabolites are potent regulators of inflammation. Generally, omega (n)-3 PUFAs are considered proresolving whereas n-6 PUFAs are classified as proinflammatory. In this study, we characterized the inflammatory response in murine peritonitis and unexpectedly found the accumulation of adrenic acid (AdA), a poorly studied n-6 PUFA. Functional studies revealed that AdA potently inhibited the formation of the chemoattractant leukotriene B4 (LTB4), specifically in human neutrophils, and this correlated with a reduction of its precursor arachidonic acid (AA) in free form. AdA exposure in human monocyte-derived macrophages enhanced efferocytosis of apoptotic human neutrophils. In vivo, AdA treatment significantly alleviated arthritis in an LTB4-dependent murine arthritis model. Our findings are, to our knowledge, the first to indicate that the n-6 fatty acid AdA effectively blocks production of LTB4 by neutrophils and could play a role in resolution of inflammation in vivo.
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