maresins

Maresins are a family of specialized pro-resolving lipid mediators derived from the omega-3 fatty acid docosahexaenoic acid (DHA). They are produced by macrophages and other cells during the resolution phase of inflammation, helping to shift the response from ongoing inflammation toward repair. The best characterized members are maresin-1 (MaR1) and maresin-2 (MaR2), and related mediators known as maresin conjugates in tissue regeneration (MCTR1–3) have also been described. Maresins were first described in scientific literature in 2009 by researchers studying the resolution of inflammation.

Biosynthesis and structure: Maresins are formed through enzymatic oxygenation of DHA, primarily in macrophages, via lipoxygenase pathways. This biosynthetic process yields MaR1, MaR2, and related conjugates that contribute to the spatial and temporal control of inflammatory resolution. They are part of the broader class of lipid mediators known as specialized pro-resolving mediators (SPMs).

Actions and mechanisms: Maresins promote resolution by several actions, including limiting neutrophil recruitment, enhancing macrophage-mediated efferocytosis and phagocytosis of apoptotic cells, and reducing the production of pro-inflammatory cytokines. They also support tissue regeneration and wound repair. Maresins exert their effects through engagement of specific G-protein coupled receptors, propagating signals that favor clearance of inflammation rather than its continuation.

Physiological and clinical relevance: Maresins have been detected in human and animal tissues and fluids, with elevated levels observed during the resolution phase of inflammation in various tissues such as the peritoneum, lung, and brain. Experimental models have shown protective effects in inflammatory diseases including colitis, arthritis, neuroinflammation, and sepsis, highlighting their potential as therapeutic targets. Ongoing research seeks to clarify receptor pathways, regulation of their synthesis, and the development of stable analogs.