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

Abstract

. 20-HETE-induced mitochondrial superoxide production and inflammatory phenotype in vascular smooth muscle is prevented by glucose-6-phosphate dehydrogenase inhibition. Am J Physiol Heart Circ Physiol 310: H1107-H1117, 2016. First published February 26, 2016 doi:10.1152/ajpheart.00961.2015 produced by cytochrome P-450 monooxygenases in NA-DPH-dependent manner is proinflammatory, and it contributes to the pathogenesis of systemic and pulmonary hypertension. In this study, we tested the hypothesis that inhibition of glucose-6-phosphate dehydrogenase (G6PD), a major source of NADPH in the cell, prevents 20-HETE synthesis and 20-HETE-induced proinflammatory signaling that promotes secretory phenotype of vascular smooth muscle cells. Lipidomic analysis indicated that G6PD inhibition and knockdown decreased 20-HETE levels in pulmonary arteries as well as 20-HETEinduced 1) mitochondrial superoxide production, 2) activation of mitogen-activated protein kinase 1 and 3, 3) phosphorylation of ETS domain-containing protein Elk-1 that activate transcription of tumor necrosis factor-␣ gene (Tnfa), and 4) expression of tumor necrosis factor-␣ (TNF-␣). Moreover, inhibition of G6PD increased protein kinase G1␣ activity, which, at least partially, mitigated superoxide production and Elk-1 and TNF-␣ expression. Additionally, we report here for the first time that 20-HETE repressed miR-143, which suppresses Elk-1 expression, and miR-133a, which is known to suppress synthetic/secretory phenotype of vascular smooth muscle cells. In summary, our findings indicate that 20-HETE elicited mitochondrial superoxide production and promoted secretory phenotype of vascular smooth muscle cells by activating MAPK1-Elk-1, all of which are blocked by inhibition of G6PD.20-HETE; TNF-␣; elk-1; mitogen-activated protein kinase 1 and 3; extracellular signal regulated kinase 2 and 1; protein kinase G; miRs 20-HYDROXYEICOSATETRAEONIC acid (20-HETE), the -hydroxylation metabolite of arachidonic acid (AA), is produced by cytochrome P-450 monooxygenases of the (CYP4A and CYP4F gene) families in an NADPH-dependent manner (49). 20-HETE is proinflammatory and it regulates vascular and renal function (49). It also plays a critical role in the pathogenesis of systemic hypertension, renal stenosis, and atherosclerosis (27,63,65). 20-HETE increased by hypoxia inhibits hypoxia-induced pulmonary artery constriction (69). However, its role in the hypoxia-induced inflammation of pulmonary arteries or lungs is yet unclear. NEWS & NOTEWORTHY 20-Hydroxyeicosatetraeonic acid (20-HETE) plays a criticalRecently, our laboratory also found that 20-HETE is involved in promoting prolonged hypoxia-induced pulmonary vasoconstriction and that glucose-6-phosphate dehydrogenase (G6PD), which is a major producer of NADPH in the cell, and cytochrome P-450 monooxygenase enzymes are functionally coupled in vascular smooth muscle tissue (unpublished observations). G6PD inhibition relaxes pulmonary arteries by decreasing intracellular calcium (20), prevents switching of vascular smooth ...

20-HETE in the regulation of vascular and cardiac function

“…As NADPH is required for 20-HETE’s biosynthesis, any manipulations in its cellular levels could results in alteration in 20-HETE levels. A recent study showed that pharmacological inhibition or knockdown of glucose 6-phosphate dehydrogenase (G6PD), a major NADPH producing enzyme, abrogates 20-HETE production in pulmonary arteries (Lakhkar et al, 2016). Interestingly, proteomic analysis by LC-MS/MS in bovine pulmonary arteries detected complexes of G6PD with CYPs suggesting that these two enzymatic systems are functionally coupled (Lakhkar et al, 2016).…”

“…20-HETE has also been shown to stimulate superoxide production and increase levels of inflammatory cytokines in smooth muscle cells. A recent study by Lakhkar et al, (Lakhkar et al, 2016) demonstrated that 20-HETE stimulates mitochondrial superoxide production and promotes the inflammatory and synthetic phenotype of pulmonary artery vascular smooth muscle cells, potentially contributing to vascular remodeling in pulmonary hypertension. Interestingly, the same group reported that 20-HETE repressed miR-143, which is known to suppress the synthetic phenotype of smooth muscle cells.…”

“…20-HETE promotes endothelial activation and inflammation that involves the secretion of inflammatory cytokines (IL-6, IL-8, TNFα) (Cheng et al, 2014; Ishizuka et al, 2008; Lakhkar et al, 2016) and expression of adhesion molecules (ICAM/VCAM) (Cheng et al, 2014; Guo et al, 2007; Guo et al, 2009; Ishizuka et al, 2008). Inhibition of 20-HETE attenuates vascular inflammation shown by inhibition of NFkB activation and reduced expression of inflammatory cytokines (Toth et al, 2013).…”

Effect of Cytochrome P450 Metabolites of Arachidonic Acid in Nephrology

“…171 It stimulates the production of ROS and inflammatory cytokines. 3,28,175,176 Polycystic kidney disease (PKD) is associated with activation of the same pathways. The production of 20-HETE is increased in the kidneys of rodents in PKD models and the sera of patients with PKD.…”

Mice Deficient in Cyp4a14 Have An Increased Number of Goblet Cells and Attenuated Dextran Sulfate Sodium-Induced Colitis

“…However, Cyp4a14 appears to induce Cyp4a10 and Cyp4a12 gene expression, which produce lipid peroxidation, since Cyp4a14-KO mouse liver exhibits significantly reduced mRNA levels of other Cyp4as [13]. The lipid peroxidation generated in the liver and kidney apparently has a systemic impact, affecting the colon, as well as other tissues, such as the cardiovascular and pulmonary systems [46,47]. A systemic effect of lipid peroxidation induced by Cyp4a14 was also detected in the present study, as Cyp4a14-KO mice exhibited lower levels of plasma MDA, a stable product of lipid peroxidation, compared with WT mice with and without DSS treatment.…”