5,14-HEDGE, a 20-HETE mimetic, reverses hypotension and improves survival in a rodent model of septic shock: Contribution of soluble epoxide hydrolase, CYP2C23, MEK1/ERK1/2/IKKβ/IκB-α/NF-κB pathway, and proinflammatory cytokine formation

Abstract

We have previously demonstrated that a stable synthetic analog of 20-HETE, N-[20-hydroxyeicosa-5(Z),14(Z)-dienoyl]glycine (5,14-HEDGE), restores vascular reactivity, blood pressure, and heart rate in endotoxemic rats. The aim of this study was to determine whether decreased renal expression and activity of soluble epoxide hydrolase (sEH), MEK1, ERK1/2, IKKβ, IκB-α, and NF-κB as well as systemic and renal proinflammatory cytokine production associated with increased expression and activity of CYP2C23 contributes to the effect of 5,14-HEDGE to prevent hypotension, tachycardia, inflammation, and mortality in response to systemic administration of lipopolysaccharide (LPS). Blood pressure fell by 33 mmHg and heart rate rose by 57 beats/min in LPS (10 mg/kg, i.p.)-treated rats. Administration of LPS also increased mRNA and protein expression of sEH associated with a decrease in CYP2C23 mRNA and protein expression. Increased activity of sEH and p-MEK1, p-ERK1/2, p-IκB-α, NF-κB, and p-NF-κB protein levels as well as TNF-α and IL-8 production by LPS were also associated with a decreased activity of AA epoxygenases. These effects of LPS were prevented by 5,14-HEDGE (30 mg/kg, s.c.; 1 h after LPS). Treatment of endotoxemic mice with 5,14-HEDGE also raised the survival rate of animals from 84% to 98%. A competitive antagonist of vasoconstrictor effects of 20-HETE, 20-hydroxyeicosa-6(Z),15(Z)-dienoic acid, 20-HEDE (30 mg/kg, s.c.; 1 h after LPS) prevented the effects of 5,14-HEDGE on blood pressure, heart rate, expression and/or activity of sEH, CYP2C23, and ERK1/2 as well as TNF-α and IL-8 levels in rats treated with LPS. These results suggest that decreased expression and/or activity of sEH and MEK1/ERK1/2/IKKβ/IκB-α/NF-κB pathway as well as proinflammatory cytokine production associated with increased CYP2C23 expression and antiinflammatory mediator formation participate in the protective effect of 5,14-HEDGE against hypotension, tachycardia, inflammation, and mortality in the rodent model of septic shock.

Effects of 5,14-HEDGE, a 20-HETE mimetic, on lipopolysaccharide-induced changes in MyD88/TAK1/IKKβ/IκB-α/NF-κB pathway and circulating miR-150, miR-223, and miR-297 levels in a rat model of septic shock

“…; sublethal dose) at time 0. In the 5,14-HEDGE and LPS+5,14-HEDGE groups, animals were treated with a stable synthetic analog of 20-HETE, 5,14-HEDGE (30 mg/kg, s.c.) [42–45] 1 h after injection of saline or LPS, respectively. 5,14-HEDGE was synthesized in the Department of Biochemistry University of Texas Southwestern Medical Center, Dallas, Texas, US.…”

“…Immunoblotting for MyD88, TAK1, phosphorylated TAK1, IκB-α, phosphorylated IκB-α, NF-κB p65, phosphorylated NF-κB p65, and actin proteins were performed according to the method described previously [42, 44, 45]. Briefly, tissue homogenates (75 μg of protein) were subjected to a 10% sodium dodecyl sulfate-polyacrylamide gel electrophoresis and then proteins were transferred to a nitrocellulose membrane.…”

“…Our previous studies with the use of a stable synthetic analog of 20-HETE, N -(20-hydroxyeicosa-5[ Z ],14[ Z ]-dienoyl)glycine, 5,14-HEDGE, which mimics the effects of endogenously produced 20-HETE, and a competitive antagonist of vasoconstrictor effects of 20-HETE, 20-hydroxyeicosa-6( Z ),15( Z )-dienoic acid, suggested that (1) increased expression and/or activity of MEK1/ERK1/2/IKKβ/IκB-α/NF-κB/inducible nitric oxide synthase (iNOS)/soluble guanylyl cyclase (sGC)/protein kinase G (PKG) pathway, nicotinamide adenine dinucleotide phosphate (NADPH) oxidases, COX-2, and soluble epoxide hydrolase (sEH), (2) overproduction of proinflammatory cytokines (i.e., TNF-α and IL-8), NO, peroxynitrite, and vasodilator prostanoids (i.e., PGI 2 and PGE 2 ), and (3) decreased CYP4A1 and CYP2C23 expression associated with vasoconstrictor (i.e., 20-HETE) and antiinflammatory mediator formation (i.e., epoxyeicosatrienoic acids; EETs) contribute to hypotension, tachycardia, inflammation, and mortality in a rodent model of septic shock [42–45]. As a continuation of our previous studies, the present study was conducted to determine whether decreased renal and cardiovascular expression and activity of MyD88/TAK1/IKKβ/IκB-α/NF-κB pathway and circulating miR-150, miR-223, and miR-297 expression levels participate in the protective effect of 5,14-HEDGE against hypotension, tachycardia, and inflammation in LPS-treated rats.…”

Altered Inflammatory Responses to Citrobacter rodentium Infection, but not Bacterial Lipopolysaccharide, in Mice Lacking the Cyp4a10 or Cyp4a14 Genes

“…If 20-HETE were involved in the effects observed here, one would expect it to be pro-inflammatory (since eliminating Cyp4a enzymes that produce it is anti-inflammatory). To the contrary, a synthetic agonistic analogue of 20-HETE was reported to reduce renal activation of NF-κB and elevation of serum TNF in LPS-induced septic shock in rats (26). 20-HETE is also a potent agonist of PPAR (27), which can exert anti-inflammatory effects via inhibition of NF-κB (28).…”

20-HETE-induced mitochondrial superoxide production and inflammatory phenotype in vascular smooth muscle is prevented by glucose-6-phosphate dehydrogenase inhibition

“…20-HETE activates mitogen-activated protein kinase (MAPK) 1 and 3 (also known as extracellular signal regulated kinase 2 and 1, respectively) and promotes secretion of cytokines, including TNF-␣, IL-8, and IL-6 (6,30,40,59). However, the sources of reactive oxygen species stimulated by 20-HETE in vascular smooth muscle cells remain unknown and the mechanisms through which 20-HETE stimulate the secretory or synthetic phenotype of vascular smooth muscle cells are not clearly understood.…”