Studies on CYP450 Epoxygenase derived Epoxyeicosatrienoic acid in Sepsis induced vascular dysfunctions in mice

Abstract

Cytochrome P450 (CYP450) enzymes are well known for biotransformation of newlinexenobiotics and metabolism of endogenous substances. The epoxyeicosatrienoic acids newline(EETs) derived from the metabolism of arachidonic acid has recently gained newlineimportance in resolution of inflammation. Sepsis, a systemic inflammatory response newlinesyndrome against microbial infection, causes multiple organ failure resulting in severe newlinemortality in human and animals worldwide. Vascular hyporeactivity and reduced newlineperipheral resistance are considered to be the leading causes of death in sepsis. newlineAlthough anti-inflammatory action of EETs is well established, their role in regulation newlineof sepsis-induced vascular dysfunction is yet to be explored. Thus, in the present newlinestudy we aimed to assess sepsis-induced expressional changes in the biosynthesizing newlineand metabolic enzymes of oxylipins (epoxygenase) in the vascular beds. Further, an newlineattempt was made to evaluate the therapeutic benefit of sEH inhibitor (EET stabilizer) newlinein sepsis-induced vascular dysfunction. Sepsis was induced by caecal ligation and newlinepuncture (CLP) in mice. The expressional changes in the CYP isoforms and sEH newlinetranscripts in vascular and non-vascular tissues were assessed by qRT-PCR and the newlineprotein expression of vascular sEH was evaluated by Western Blot and newlineimmunohistochemistry (IHC). Vascular reactivity of conduit (aorta) and resistant newlineartery (mesenteric artery) was assessed by organ bath and wire myograph, newlinerespectively. Sepsis significantly (p lt 0.01) reduced the survival time (19.11 ± 1.14 newlineh, N=22) in mice as compared to SO mice. Further, sepsis produced tissue- and newlineisoform-specific differential effect on the mRNA expression profiles of Cyp2c and newlineCyp2j isoforms (biosynthesizing EETs) in vascular and non-vascular tissues. For newlineexample, a significant (p lt 0.05) upregulation of Cyp2j6 transcript expression was newlineobserved in the aorta of septic mice while expression of Cyp2j9 (in aorta) as well as newlineCyp2j6 and Cyp2j9 (in mesenteric artery) remained unaltered in septic mice. In no