Local production and downstream metabolism of specialized proresolving lipid mediators (SPMs) are pivotal in regulating their biological actions during resolution of inflammation. Resolvin D4 (RvD4: 4S,5R,17S-trihydroxydocosa-6E,8E,10Z,13Z,15E,19Z hexaenoic acid) is one of the more recently elucidated SPMs with complete stereochemistry biosynthesized from docosahexaenoic acid . Here, we report a new multimilligram commercial synthesis that afforded enough material for matching, validation, and further evaluation of RvD4 functions. Using LC-MS-MS profiling, RvD4 was identified at bioactive amounts in human (1 pg/mL) and mouse bone marrow (12 pg/femur and tibia). In mouse bone marrow, ischemia increased the formation of RvD4 > 37-fold (455 pg/femur and tibia). Two separate mouse ischemic injury models were used, where RvD4 reduced second organ reperfusion lung injury > 50%, demonstrating organ protection. Structure-function relationships of RvD4 demonstrated > 40% increase in neutrophil and monocyte phagocytic function in human whole blood in comparison with 2 separate trans-containing double bond isomers that were inactive. These 2 isomers were prepared by organic synthesis: 4S,5R,17S-trihydroxydocosa-6E,8E,10E,13Z,15E,19Z-hexaenoic acid (10-trans-RvD4), a natural isomer, and 4S,5R,17S-trihydroxydocosa-6E,8E,10E,13E,15E,19Z-hexaenoic acid (10,13-trans-RvD4), a rogue isomer. Compared to leukotriene B4 , D-series resolvins (RvD1, RvD2, RvD3, RvD4, or RvD5) did not stimulate human neutrophil chemotaxis monitored via real-time microfluidics chambers. A novel 17-oxo-containing-RvD4 product of eicosanoid oxidoreductase was identified with human bone marrow cells. Comparison of 17-oxo-RvD4 to RvD4 demonstrated that with human leukocytes 17-oxo-RvD4 was inactive. Together, these provide commercial-scale synthesis that permitted a second independent validation of RvD4 complete stereochemical structure as well as evidence for RvD4 regulation in tissues and its stereoselective phagocyte responses.

中文翻译：

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通过新的全有机合成和验证，了解 Resolvin D4 作用和进一步代谢物的结构。


专门的促消解脂质介质（SPM）的局部产生和下游代谢对于炎症消退过程中调节其生物学作用至关重要。 Resolvin D4（RvD4：4S，5R，17S-三羟基二十二碳六烯酸-6E，8E，10Z，13Z，15E，19Z六烯酸）是最近阐明的具有完整立体化学的SPM之一，由二十二碳六烯酸生物合成。在这里，我们报告了一种新的多毫克商业合成，为 RvD4 功能的匹配、验证和进一步评估提供了足够的材料。使用 LC-MS-MS 分析，在人骨髓 (1 pg/mL) 和小鼠骨髓 (12 pg/股骨和胫骨) 中鉴定出 RvD4 的生物活性量。在小鼠骨髓中，缺血使 RvD4 的形成增加 > 37 倍（455 pg/股骨和胫骨）。使用两个单独的小鼠缺血性损伤模型，其中 RvD4 减少第二器官再灌注肺损伤 > 50%，证明了器官保护。 RvD4 的结构-功能关系表明，与 2 个单独的无活性的含反式双键异构体相比，人全血中的中性粒细胞和单核细胞吞噬功能增加 > 40%。这 2 种异构体是通过有机合成制备的：4S,5R,17S-三羟基二十二碳六烯酸-6E,8E,10E,13Z,15E,19Z-己烯酸（10-反式-RvD4），一种天然异构体，和 4S,5R,17S-三羟基二十二碳六烯酸-6E,8E,10E,13E,15E,19Z-己烯酸（10,13-反式-RvD4），一种流氓异构体。与白三烯 B4 相比，D 系列解析素（RvD1、RvD2、RvD3、RvD4 或 RvD5）不会刺激通过实时微流体室监测的人中性粒细胞趋化性。在人骨髓细胞中鉴定出一种新的类二十烷酸氧化还原酶的含 17-氧代-RvD4 产物。 17-oxo-RvD4 与 RvD4 的比较表明，对于人类白细胞，17-oxo-RvD4 没有活性。 总之，这些提供了商业规模的合成，允许对 RvD4 完整立体化学结构进行第二次独立验证，并提供组织中 RvD4 调节及其立体选择性吞噬细胞反应的证据。