IntroductionInflammation is the organisms' response to local injury in vascularized tissues programmed to traffic leukocytes and plasma delivery to an injured site or point of bacterial invasion, 1 this protective response when uncontrolled in humans is associated with many widely occurring diseases. These include cardiovascular, metabolic, and the classic inflammatory diseases (ie, arthritis and periodontal disease) along with cancers. 2 Nonresolving inflammation is now widely acknowledged as a major driver in most of these diseases. 3 Resolution of inflammation and dissipation of the local chemical messengers involved in mounting the innate response were thought to be passively diluted with time at the site, hence stopping further leukocyte recruitment and resolving the exudate or battlefield of inflammation. 4,5 Results from this laboratory indicate that resolution of selflimited inflammatory exudates is a biochemically active process that involves the local and temporal biosynthesis of a new genus of specialized pro-resolving mediators (SPMs) with their novel functions mapped employing resolution indices. [5][6][7][8] SPMs encompass several families of structurally and chemically distinct mediators. These chemical mediator families include lipoxins biosynthesized from arachidonic acid, E-series resolvins (Rv) from eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA)-derived D-series resolvins, protectins, and maresins. Each potent bioactive member of these families shares a defining action in resolving local inflammation. By definition, they each limit further neutrophil (PMN) recruitment to the site of injury and/or microbial invasion and enhance macrophage uptake of cellular debris and apoptotic PMN to bring about tissue homeostasis. 2 Along with these defining properties, specific SPMs carry out more specialized tasks within programmed resolution; hence, the scope of their individual actions are nonoverlapping and evoked via specific cell surface receptors that are G-protein-coupled receptors. 2 A systems approach led to the identification of novel bioactive structures coined resolvins and protectins in murine inflammatory exudates and isolated human cells based on liquid chromatography tandem mass spectrometry (LC-MS-MS)-based lipid mediator lipidomics and tandem assessment of their functions in anti-inflammation and pro-resolution. 6,9 The complete stereochemistry and total organic synthesis of several key resolvins, protectins, as well as their aspirin-triggered forms are established. 10 These include resolvin D1 (7S, 8R, 17S-trihydroxy-4Z, 9E, 11E, 13Z, 15E, 19Z-docosahexaenoic acid), resolvin D2 (7S, 16R, 17S-trihydroxy-4Z, 8E, 10Z, 12E, 14E, 19Z-DHA), 17R-HDHA (17R-hydroxy-4Z,7Z,10Z,13Z,15E,19Z-DHA), neuroprotectin D1/NPD1 (10R, 17S-dihydroxy-4Z, 7Z, 11E, 13E, 15Z, 19Z-DHA), resolvin E1 (5S, 12R, 18R-trihydroxy-6Z, 8E, 10E, 14Z, 16E-eicosapentaenoic acid), and most recently maresin 1 (7R, 14S-dihydroxy-4Z,8E,10E,12Z,16Z, . 11 In addition to confirming the original structural assignments and...