Altered leukotriene B-4 metabolism in CYP4F18-deficient mice does not impact inflammation following renal ischemia

作者：Winslow Valeria; Vaivoda Rachel; Vasilyev Aleksandr; Dombkowski David; Douaidy Karim; Stark Christopher; Drake Justin; Guilliams Evin; Choudhary Dharamainder; Preffer Frederic; Stoilov Ivaylo; Christmas Peter^*

来源：Biochimica et Biophysica Acta-Molecular and Cell Biology of Lipids, 2014, 1841(6): 868-879.

DOI：10.1016/j.bbalip.2014.03.002

• Cytochrome P450
• Neutrophil
• Leukotriene B4
• omega-Hydroxylase
• Inflammation

Inflammatory responses to infection and injury must be restrained and negatively regulated to minimize damage to host tissue. One proposed mechanism involves enzymatic inactivation of the pro-inflammatory mediator leukotriene B-4, but it is difficult to dissect the roles of various metabolic enzymes and pathways. A primary candidate for a regulatory pathway is omega oxidation of leukotriene B-4 in neutrophils, presumptively by CYP4F3A in humans and CYP4F18 in mice. This pathway generates omega, omega-1, and omega-2 hydroxylated products of leukotriene B4, depending on species. We created mouse models targeting exons 8 and 9 of the Cyp4f18 allele that allows both conventional and conditional knockouts of Cyp4f18. Neutrophils from wild-type mice convert leukotriene B-4 to 19-hydroxy leukotriene B-4, and to a lesser extent 18-hydroxy leukotriene B-4, whereas these products were not detected in neutrophils from conventional Cyp4f18 knockouts. A mouse model of renal ischemia-reperfusion injury was used to investigate the consequences of loss of CYP4F18 in vivo. There were no significant changes in infiltration of neutrophils and other leukocytes into kidney tissue as determined by flow cytometry and immunohistochemistry, or renal injury as assessed by histological scoring and measurement of blood urea nitrogen. It is concluded that CYP4F18 is necessary for omega oxidation of leukotriene B-4 in neutrophils, and is not compensated by other CYP enzymes, but loss of this metabolic pathway is not sufficient to impact inflammation and injury following renal ischemia-reperfusion in mice.

• 出版日期2014-6