8-11-14-eicosatrienoic-acid and Heart-Diseases

NLRX1 weakens lipopolysaccharide (LPS)-induced NF-κB activation on immune cells. Cytochrome P450 epoxygenase 2J2 (CYP2J2) attenuates LPS-induced cardiac injury by inhibiting NF-κB activation. However, it is still unclear whether NLRX1 could reduce LPS-induced heart damage and whether it is involved in the anti-LPS cardioprotective effect of CYP2J2. In this study, we found that NLRX1 knockout further exacerbated LPS-induced heart injury and up-regulated the proinflammatory cytokines in serum and heart tissue, and weakened the inhibitory effect of CYP2J2 on the harmful effects caused by LPS. We also found that LPS treatment induced ubiquitination of NLRX1 and promoted its binding to IKKα/β in myocardial tissue, which should theoretically inhibit NF-κB activation. However, LPS eventually leads to activation of NF-κB and NLRP3 inflammasome. Under the action of LPS, CYP2J2 further promoted the ubiquitination of NLRX1 and its binding to IKKα/β, impaired NF-κB activation and NLRP3 inflammasome activation. NLRX1 knockout notably aggravated LPS-induced NF-κB activation and NLRP3 inflammasome activation, and attenuated the inhibitory effects of CYP2J2 on NF-κB signal and NLRP3 inflammasome. More, CYP2J2 reduced LPS-induced reactive oxygen species (ROS) production and mitochondrial depolarization in heart cells, thereby inhibiting NLRP3 inflammasome activation. NLRX1 knockdown aggravated mitochondrial depolarization induced by LPS and weakened the protective effect of CYP2J2 on mitochondrial potential, although it had no significant effect on reactive oxygen species production. Together, these findings demonstrated that NLRX1 knockout aggravated LPS-induced heart injury and weakened the anti-LPS cardioprotective effect of CYP2J2 by enhancing activation of NF-κB and NLRP3 inflammasome.

Topics: 8,11,14-Eicosatrienoic Acid; Animals; Cytochrome P-450 CYP2J2; Cytochrome P-450 Enzyme System; Cytokines; Disease Models, Animal; Heart Diseases; Inflammasomes; Inflammation Mediators; Lipopolysaccharides; Male; Mice, Inbred C57BL; Mice, Transgenic; Mitochondria, Heart; Mitochondrial Proteins; Myocytes, Cardiac; NF-kappa B; NLR Family, Pyrin Domain-Containing 3 Protein; Reactive Oxygen Species; Signal Transduction

Life threatening complications from chemotherapy occur frequently in cancer survivors, however little is known about genetic risk factors. We treated male normotensive rats (WKY) and strains with hypertension (SHR) and hypertension with cardiomyopathy (SHHF) with 8 weekly doses of doxorubicin (DOX) followed by 12weeks of observation to test the hypothesis that genetic cardiovascular disease would worsen delayed cardiotoxicity. Compared with WKY, SHR demonstrated weight loss, decreased systolic blood pressure, increased kidney weights, greater cardiac and renal histopathologic lesions and greater mortality. SHHF showed growth restriction, increased kidney weights and renal histopathology but no effect on systolic blood pressure or mortality. SHHF had less severe cardiac lesions than SHR. We evaluated cardiac soluble epoxide hydrolase (sEH) content and arachidonic acid metabolites after acute DOX exposure as potential mediators of genetic risk. Before DOX, SHHF and SHR had significantly greater cardiac sEH and decreased epoxyeicosatrienoic acid (EET) (4 of 4 isomers in SHHF and 2 of 4 isomers in SHR) than WKY. After DOX, sEH was unchanged in all strains, but SHHF and SHR rats increased EETs to a level similar to WKY. Leukotriene D4 increased after treatment in SHR. Genetic predisposition to heart failure superimposed on genetic hypertension failed to generate greater toxicity compared with hypertension alone. The relative resistance of DOX-treated SHHF males to the cardiotoxic effects of DOX in the delayed phase despite progression of genetic disease was unexpected and a key finding. Strain differences in arachidonic acid metabolism may contribute to variation in response to DOX toxicity.

Topics: 8,11,14-Eicosatrienoic Acid; Animals; Arachidonic Acid; Blood Pressure; Body Weight; Cardiotoxins; Chromatography, High Pressure Liquid; Doxorubicin; Epoxide Hydrolases; Genetic Predisposition to Disease; Heart Diseases; Kidney; Leukotriene D4; Male; Organ Size; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Troponin T; Ventricular Function, Left

Cardiorenal syndromes were defined and classified recently, but the mechanism of chronic renocardiac syndrome remains disputed. Theories about chronic renocardiac syndrome cannot offer a convincing explanation for it. As a result, the current therapies of chronic renocardiac syndrome do not contribute to a satisfied prognosis. Epoxyeicosatrienoic acids, the products of arachidonic acid metabolized by cytochrome P450 enzymes, play an important role in the maintenance of renal hemodynamics, and regulation of renal, cardiac, and vascular function with antihypertensive and anti-inflammatory properties. It is well documented that down-regulation of epoxyeicosatrienoic acids might be involved in alterations in various pathophysiological states, including hypertension, uremia and hepatorenal syndrome. Likewise, epoxyeicosatrienoic acids were reduced in heart failure and renal dysfunction. This leads to the proposed hypothesis that epoxyeicosatrienoic acids down-regulation may be the novel mechanism of chronic renocardiac syndrome. These findings suggest that manipulation of epoxyeicosatrienoic acid levels could be a novel pharmacological therapy strategy for chronic renocardiac syndrome.

Topics: 8,11,14-Eicosatrienoic Acid; Chronic Disease; Heart Diseases; Humans; Kidney Diseases; Syndrome

Topics: 8,11,14-Eicosatrienoic Acid; Animals; Arachidonic Acid; Cardiotonic Agents; Cytochrome P-450 Enzyme System; Dogs; Heart Diseases; Hydroxyeicosatetraenoic Acids