87042-40-8

Lipoxygenase (LOX) is the key enzyme involved in the synthesis of oxylipins as signaling compounds that are important for cell growth and development, inflammation, and pathogenesis in various organisms. The regiospecificity of LOX from Myxococcus xanthus, a gram-negative bacterium, was investigated. The enzyme catalyzed oxygenation at the n-9 position in C20 and C22 polyunsaturated fatty acids (PUFAs) to form 12S- and 14S-hydroxy fatty acids (HFAs), respectively, and oxygenation at the n-6 position in C18 PUFAs to form 13-HFAs. The 12S-form products of C20 and C22 PUFAs by M. xanthus LOX is the first report of bacterial LOXs. The residues involved in regiospecificity were determined to be Thr397, Ala461, and Ile664 by analyzing amino acid alignment and a homology model based on human arachidonate 15-LOX with a sequence identity of 25%. Among these variants, the regiospecificity of the T397Y variant for C20 and C22 PUFAs was changed. This may be because of the reduced size of the substrate-binding pocket by substitution of the smaller Thr to the larger Tyr residue. The T397Y variant catalyzed oxygenation at the n-6 position in C20 and C22 PUFAs to form 15- and 17-hydroperoxy fatty acids, respectively. However, the oxygenation position of T397Y for C18 PUFAs was not changed. The discovery of bacterial LOX with novel regiospecificity will facilitate the biosynthesis of regiospecific?oxygenated signaling compounds.

Summary Nonhealing diabetic wounds are associated with impaired macrophage (Mf) function. Leukocytes and platelets (PLT) play crucial roles in wound healing by poorly understood mechanisms. Here we report the identification and characterization of the maresin-like(L) mediators 14,22-dihydroxy-docosa-4Z,7Z,10Z,12E,16Z,19Z-hexaenoic acids, 14S,22-diHDHA (maresin-L1), and 14R,22-diHDHA (maresin-L2) that are produced by leukocytes and PLT and involved in wound healing. We show that 12-lipoxygenase-initiated 14S-hydroxylation or cytochrome P450 catalyzed 14R-hydroxylation and P450-initiated ω(22)-hydroxylation are required for maresin-L biosynthesis. Maresin-L treatment restores reparative functions of diabetic Mfs, suggesting that maresin-Ls act as autocrine/paracrine factors responsible for, at least in part, the reparative functions of leukocytes and PLT in wounds. Additionally, maresin-L ameliorates Mf inflammatory activation and has the potential to suppress the chronic inflammation in diabetic wounds caused by activation of Mfs. These findings provide initial insights into maresin-L biosynthesis and mechanism of action and potentially offer a therapeutic option for better treatment of diabetic wounds.

Acute ethanol intoxication and exposure (AE) has been known to impair wound healing and associated angiogenesis. Here, we found that AE diminished the formation of novel reparative lipid mediator 14S,21-dihydroxy-docosa-4Z,7Z,10Z, 12E,16Z,19Z-hexaenoic acid (14S,21-diHDHA) and its biosynthetic intermediate 14S-hydroxy-DHA (14S-HDHA) from docosahexaenoic acid (DHA) in murine wounds. However, AE did not reduce the formation of DHA and the intermediate 21-HDHA. These results indicate that in the biosynthetic pathways of 14S, 21-diHDHA in wounds, AE suppresses the 14S-hydroxy-generating activity of 12-lipoxygenase-like (LOX-like), but does not suppress the 21-hydroxy-generating activity of cytochrome P450 and DHA-generating activities. The AE-suppression of 12-LOX-like activity was further confirmed by the diminished formation of 12-hydroxy-eicosatetraenoic acid in wounds under AE. Supplementing 14S,21-diHDHA to wounds rescued the AE-impaired healing and vascularization. 14S,21-diHDHA restored AE-impaired processes of angiogenesis in vitro: endothelial cell migration, tubulogenesis, and phosphorylation of p38 mitogen-activated protein kinase (MAPK). Taken together, the suppression of 14S,21-diHDHA formation is responsible, at least partially, for the AE-impairment of cutaneous wound healing and angiogenesis. Supplementing 14S,21-diHDHA to compensate its deficit in AE-impaired wounds rescues the healing and angiogenesis. These results provide a novel mechanistic insight for AE-impaired wound healing that involves the necessary roles of 14S,21-diHDHA. They also offer leads for developing 14S,21-diHDHA-related therapeutics to ameliorate AE-impairment of wound healing.

The invention describes novel 14-hydroxy docosahexaenoic acid (DHA) analogues, their preparation, isolation, identification, purification and uses thereof.

Disclosed are novel oxylipins, referred to herein as docosanoids, that are derived from C22 polyunsaturated fatty acids, and method of making and using such oxylipins. Also disclosed is the use of docosapentaenoic acid (C22:5n-6) (DPAn-6), docosapentaenoic acid (C22:5n-3) (DPAn-3), and docosatetraenoic acid (DTAn-6: C22:4n-6) as substrates for the production of novel oxylipins, and to the oxylipins produced thereby. Also disclosed is the use of DPAn-6, DPAn-3, DTAn-6, and/or the oxylipins derived therefrom, and/or novel docosanoids derived from the structures of C22 fatty acids, in therapeutic and nutritional or cosmetic applications, and particularly as anti-inflammatory or anti-neurodegenerative compounds. The invention also relates to novel ways of producing long chain polyunsaturated acid (LCPUFA)-rich oils and compositions that contain enhanced and effective amounts of LCPUFA-derived oxylipins, and particularly, docosanoids.