Simvastatin and a plant galactolipid protect animals from septic shock by regulating oxylipin mediator dynamics through the MAPK-cPLA2 signaling pathway

Sepsis remains a major medical issue despite decades of research. Identification of important inflammatory cascades and key molecular mediators are crucial for developing intervention and prevention strategies. In this study, we conducted a comparative oxylipin metabolomics study to gain a comprehensive picture of lipid mediator dynamics during the initial hyper-inflammatory phase of sepsis, and demonstrated, in parallel, the efficacy of simvastatin and plant galactolipid, 1,2-di-O-α-linolenoyl-3-O-β-galactopyranosyl-sn-glycerol (dLGG) in the homeostatic regulation of the oxylipin metabolome using a lipopolysaccharide (LPS)-induced sepsis C57BL/6J mouse model. LPS increased the systemic and organ levels of pro-inflammatory metabolites of linoleic acid including leukotoxin diols, i.e., 9,10-DHOME, 12,13-DHOME, and octadecadienoic acids, i.e., 9-HODE and 13-HODE; and arachidonic acid-derived prostanoid, PGE2, and hydroxyeicosatetraenoic acids, i.e., 8, 12- and 15-HETE. Treatment with either compound decreased the levels of pro-inflammatory metabolites and elevated pro-resolution lipoxin A4, 5(6)-EET, 11(12)-EET and 15-deoxy-PGJ2. dLGG and simvastatin ameliorated the effects of LPS-induced MAPK-dependent activation of cPLA2, cyclooxygenase-2, lipoxygenase, cytochrome P450, and/or epoxide hydrolase, lowered systemic TNF- and IL-6 levels and aminotransferase activities and decreased organ-specific infiltration of inflammatory leukocytes and macrophages, and septic shock-induced multiple organ damage. Furthermore, both dLGG and simvastatin increased the survival rates in the cecal ligation and puncture (CLP) sepsis model. This study provides new insights into the role of oxylipins in sepsis pathogenesis and highlights the potential of simvastatin and dLGG in sepsis therapy and prevention. (USA and ROC patent pending; One technology transfer to a biotech company)


Co-researchers:Maria Karmella Apaya, Chih-Yu Lin, Ching-Yi Chiou, Chung-Chih Yang, Chen-Yun Ting and Lie-Fen Shyur