Cytochrome P450 Epoxygenase 2J2 Research Articles

ROS-responsive nanoparticle-mediated delivery of CYP2J2 gene for therapeutic angiogenesis in severe hindlimb ischemia.

With critical limb ischemia (CLI) being a multi-factorial disease, it is becoming evident that gene therapy with a multiple bio-functional growth factor could achieve better therapeutic outcomes. Cytochrome P450 epoxygenase-2J2 (CYP2J2) and its catalytic products epoxyeicosatrienoic acids (EETs) exhibit pleiotropic biological activities, including pro-angiogenic, anti-inflammatory and cardiovascular protective effects, which are considerably beneficial for reversing ischemia and restoring local blood flow in CLI. Here, we designed a nanoparticle-based pcDNA3.1-CYP2J2 plasmid DNA (pDNA) delivery system (nanoparticle/pDNA complex) composed of a novel three-arm star block copolymer (3S-PLGA-po-PEG), which was achieved by conjugating three-armed PLGA to PEG via the peroxalate ester bond. Considering the multiple bio-functions of CYP2J2-EETs and the sensitivity of the peroxalate ester bond to H2O2, this nanoparticle-based gene delivery system is expected to exhibit excellent pro-angiogenic effects while improving the high oxidative stress and inflammatory micro-environment in ischemic hindlimb. Our study reports the first application of CYP2J2 in the field of therapeutic angiogenesis for CLI treatment and our findings demonstrated good biocompatibility, stability and sustained release properties of the CYP2J2 nano-delivery system. In addition, this nanoparticle-based gene delivery system showed high transfection efficiency and efficient VEGF expression in vitro and in vivo. Intramuscular injection of nanoparticle/pDNA complexes into mice with hindlimb ischemia resulted in significant rapid blood flow recovery and improved muscle repair compared to mice treated with naked pDNA. In summary, 3S-PLGA-po-PEG/CYP2J2-pDNA complexes have tremendous potential and provide a practical strategy for the treatment of limb ischemia. Moreover, 3S-PLGA-po-PEG nanoparticles might be useful as a potential non-viral carrier for other gene delivery applications.

NLRX1 knockout aggravates lipopolysaccharide (LPS)-induced heart injury and attenuates the anti-LPS cardioprotective effect of CYP2J2/11,12-EET by enhancing activation of NF-κB and NLRP3 inflammasome

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.

EETs reduces LPS-induced hyperpermeability by targeting GRP78 mediated Src activation and subsequent Rho/ROCK signaling pathway.

Integrity of endothelial barrier is a determinant of the prognosis in the acute lung injury caused by sepsis. The epoxyeicosatrienoic acids (EETs), metabolites of arachidonic acid, exhibit protective effects in various pathogenic states, however, whether EETs play a role in endothelial barrier enhancement and the involved mechanisms remain to be investigated. Here, we show that increased EETs level by endothelial specific cytochrome P450 epoxygenase 2J2 over-expression and soluble epoxide hydrolase (sEH) inhibitor TPPU reduced lipopolysaccharide-induced endothelial hyper-permeability in vivo, accompanied by improved survival of septic mice. In addition, sEH inhibitor AUDA and 11,12-EET also decreased endothelial hyper-permeability in the in-vitro study. Importantly, the relative mechanisms were associated with reduced GRP78-Src interaction and ROS production, and subsequently reduced RhoA/ROCK activation, and eventually decreased VE-cadherin and myosin light chain (MLC) phosphorylation. Thus CYP2J2-EETs is crucial for RhoA-dependent regulation of cytoskeletal architecture leading to reversible changes in vascular permeability, which may contribute to the development of new therapeutic approaches for pulmonary edema and other diseases caused by abnormal vascular permeability.

GW27-e0817 Gene Delivery of CYP2J2 Ameliorates Right Ventricular Remodelling in Monocrotaline-induced Pulmonary Hypertension in Rats

We aimed to observe the effects of cytochrome P450 epoxygenase 2J2 (CYP2J2) overexpression on right ventricular remodelling in monocrotaline-induced pulmonary hypertension in rats. Forty SD rats were randomly divided into normal control group (NC group), monocrotaline group (MCT group), pCB6-

Epoxyeicosatrienoic acids regulate macrophage polarization and prevent LPS-induced cardiac dysfunction.

Macrophages, owning tremendous phenotypic plasticity and diverse functions, were becoming the target cells in various inflammatory, metabolic and immune diseases. Cytochrome P450 epoxygenase 2J2 (CYP2J2) metabolizes arachidonic acid to form epoxyeicosatrienoic acids (EETs), which possess various beneficial effects on cardiovascular system. In the present study, we evaluated the effects of EETs treatment on macrophage polarization and recombinant adeno-associated virus (rAAV)-mediated CYP2J2 expression on lipopolysaccharide (LPS)-induced cardiac dysfunction, and sought to investigate the underlying mechanisms. In vitro studies showed that EETs (1µmol/L) significantly inhibited LPS-induced M1 macrophage polarization and diminished the proinflammatory cytokines at transcriptional and post-transcriptional level; meanwhile it preserved M2 macrophage related molecules expression and upregulated anti-inflammatory cytokine IL-10. Furthermore, EETs down-regulated NF-κB activation and up-regulated peroxisome proliferator-activated receptors (PPARα/γ) and heme oxygenase 1 (HO-1) expression, which play important roles in regulating M1 and M2 polarization. In addition, LPS treatment in mice induced cardiac dysfunction, heart tissue damage and infiltration of M1 macrophages, as well as the increase of inflammatory cytokines in serum and heart tissue, but rAAV-mediated CYP2J2 expression increased EETs generation in heart and significantly attenuated the LPS-induced harmful effects, which mechanisms were similar as the in vitro study. Taken together, the results indicate that CYP2J2/EETs regulates macrophage polarization by attenuating NF-κB signaling pathway via PPARα/γ and HO-1 activation and its potential use in treatment of inflammatory diseases.

Increased Endothelial Expression of Human Cytochrome P450 Epoxygenase 2J2 Positively Modulates Coronary Reactive Hyperemia in Isolated Mouse Heart

Impaired coronary reactive hyperemia (RH) is associated with increased cardiovascular disease. Epoxyeicosatrienoic acids (EETs) exert cardioprotective effects in ischemia / reperfusion injury. Cytochrome P450 epoxygenase 2J2 partly generates EETs from arachidonic acid. EETs level is increased in mice with increased endothelial expression of CYP2J2 (Tie2‐CYP2J2 tr). We hypothesized that the isolated heart from Tie2‐CYP2J2 tr mouse exhibits increased RH through increased generation of EETs in response to no‐flow ischemia compared to wild type (WT). Coronary flow (CF) in isolated Tie2‐CYP2J2 Tr and WTmouse heart was measured using Langendorff system. Perfused heart was exposed to 15 second ischemia and RH was assessed. Flow repayment volume (RV) (the area under the curve normalized to heart weight (ml/g)) was significantly increased in Tie2‐CYP2J2 Tr compared to WT(9.8 ± 0.9 in Tie2‐CYP2J2 Tr vs. 6.4 ± 0.5 in WT, p<0.05). Tie2‐CYP2J2 Tr exhibited significantly longer repayment duration when compared to WT (2.5 ± 0.4 in Tie2‐CYP2J2 Tr vs. 1.7 ± 0.2 in WT, p<0.05). MS‐PPOH (CYP epoxygenase inhibitor, 1.0 mM) decreased RH in Tie2‐CYP2J2 Tr (7.96 ± 0.41 with MS‐PPOH vs. 9.8 ± 0.9 without MS‐PPOH , p<0.05), but not in WT. Our results demonstrate that increased endothelial expression of CYP2J2 increases RH compared to WT; also, MS‐PPOH decreases RH in Tie2‐CYP2J2 but not in WT. These data suggest that increased level of CYP2J2 could have a beneficial effect on myocardial recovery from short ischemia. Supported by HL‐114559 to MAN, z01‐ES025034 to DCZ and GM31278 to JRF

14,15-Epoxyeicosatrienoic Acid Suppresses Cigarette Smoke Extract-Induced Apoptosis in Lung Epithelial Cells by Inhibiting Endoplasmic Reticulum Stress

Background/Aims: Epoxyeicosatrienoic acids (EETs), a type of lipid mediators produced by cytochrome P450 epoxygenases, exert anti-inflammatory, angiogenic, anti-oxidative and anti-apoptotic effects. However, the role of EETs in cigarette smoke-induced lung injury and the underlying mechanisms are not fully known. The aim of this study was to explore the effects of CYP2J2-EETs on cigarette smoke extracts (CSE)-induced apoptosis in human bronchial epithelial cell line (Beas-2B) and the possible mechanisms involved. Methods: Cytochrome P450 epoxygenase 2J2 (CYP2J2) and its metabolites EETs were assessed by western blotting or LC-MS-MS. Cell viability and apoptosis were determined by MTT assay and AnnexinV-PI staining. Reactive oxygen species (ROS) were assessed by measuring H2DCFDA. Caspase-3, HO-1, MAPK and endoplasmic reticulum (ER) stress-related markers GRP78, p-elF2a, and CHOP were evaluated by western blotting. Results: CSE suppressed expression of both CYP2J2 and EET by Beas-2B cells. CSE also induced apoptosis, the generation of ROS and the ER stress in Beas-2B cells. These changes were abolished by pretreatment with exogenous 14,15-EET while pretreatment with 14,15-EEZE, a selective EET antagonist, abolished the protective effects of 14,15-EET. In addition, EETs increased the expression of antioxidant enzyme HO-1. Furthermore, 14,15-EET reduced CSE-induced activation of p38 and JNK. Conclusion: The data suggest that CYP2J2-derived EETs protect against CSE-induced lung injury possibly through attenuating ER stress.

CYP2J2 and EETs Protect Against Lung Ischemia/Reperfusion Injury via Anti-Inflammatory Effects in Vivo and in Vitro

Background: Injurious inflammatory response is critical to the development of lung ischemia/reperfusion injury (LIRI). The cytochrome P450 epoxygenase 2J2 (CYP2J2) metabolizes arachidonic acid to epoxyeicosatrienoic acids (EETs), which exert an anti-inflammatory effect on the cardiovascular system. We therefore cytochrome hypothesized that CYP2J2 overexpression and pretreatment with exogenous EETs may have the potential to reduce LIRI. Methods: A rat model was used to mimic the condition of LIRI by clamping the left pulmonary hilum for 60 minutes, followed by reperfusion for 2 hours. Moreover, we developed a cell model using human pulmonary artery endothelial cells by anoxia for 8 hours, followed by reoxygenation for 16 hours to determine the anti-inflammatory effect and mechanism of CYP2J2 overexpression and exogenous 11,12-EET. Results: Lung ischemia/reperfusion increased lung wet/dry and lung weight/body weight ratios, protein concentration in bronchoalveolar lavage fluid and concentrations of pro-inflammatory, including mediators in serum IL-1ß, IL-8, TNF-a, sP- and sE-selectin, and decreased concentration of anti-inflammatory mediator IL-10. Ischemia/reperfusion also leaded to pulmonary edema and inflammation under light microscopy. Furthermore, activation of NF-γB p65 and degradation of IγBa were remarkably increased in ischemia/reperfusion lung tissues. While CYP2J2 overexpression significantly inhibited the above effects (p<0.05). In vitro data further confirmed the anti-inflammatory effect of CYP2J2 overexpression and 11,12-EET, an effect that may probably be mediated by PPARγ activation. Conclusion: CYP2J2 overexpression and administration of exogenous EETs can protect against LIRI via anti-inflammatory effects. This can be a novel potential strategy for prevention and treatment of LIRI.

CYP2J2 and EETs Protect against Oxidative Stress and Apoptosis in Vivo and in Vitro Following Lung Ischemia/Reperfusion

Background: Cytochrome P450 epoxygenase 2J2 (CYP2J2) metabolizes arachidonic acids to epoxyeicosatrienoic acids (EETs). EETs exert various biological effects, including anti-inflammatory, anti-apoptotic, pro-proliferation, pro-angiogenesis, anti-oxidation, and anti-fibrosis effects. However, little is known about the role of CYP2J2 and EETs in lung ischemia/reperfusion injury. In this study, we examined the effects of exogenous EETs or CYP2J2 overexpression on lung ischemia/reperfusion injury in vivo and in vitro. Methods and Results: CYP2J2 gene was stably transfected into rat lungs via pcDNA3.1-CYP2J2 plasmid delivery, resulting in increased EETs levels in the serum and lung. A rat model of lung ischemia/reperfusion injury was developed by clamping the left lung hilum for 1 hour, followed by reperfusion for 2 hours. We found that CYP2J2 overexpression markedly decreased the levels of oxidative stress and cell apoptosis in lung tissues induced by ischemia/reperfusion. Moreover, we observed that exogenous EETs, or CYP2J2 overexpression, enhanced cell viability, decreased intracellular reactive oxygen species (ROS) generation, inhibited mitochondrial dysfunction, and attenuated several apoptotic signaling events in a human pulmonary artery endothelial cells (HPAECs)-based anoxia/reoxygenation model. These apoptotic events included activation of NADPH oxidase, collapse of mitochondrial transmembrane potential, and activation of pro-apoptotic proteins and caspase-3. These effects were mediated, at least partially, by the PI3K/Akt signaling pathway. Conclusion: These results reveal that CYP2J2 overexpression and exogenous EETs can protect against oxidative stress and apoptosis following lung ischemia/reperfusion in vivo and in vitro, suggesting that increasing the level of EETs may be a novel promising strategy to prevent and treat lung ischemia/reperfusion injury.

CYP2J2 overexpression increases EETs and protects against angiotensin II-induced abdominal aortic aneurysm in mice

Cytochrome P450 epoxygenase 2J2 (CYP2J2) metabolizes arachidonic acids to form epoxyeicosatrienoic acids (EETs), which possess various beneficial effects on the cardiovascular system. However, whether increasing EETs production by CYP2J2 overexpression in vivo could prevent abdominal aortic aneurysm (AAA) remains unknown. Here we investigated the effects of recombinant adeno-associated virus (rAAV)-mediated CYP2J2 overexpression on angiotensin (Ang) II-induced AAA in apoE-deficient mice. rAAV-CYP2J2 delivery led to an abundant aortic CYP2J2 expression and increased EETs generation. It was shown that CYP2J2 overexpression attenuated matrix metalloproteinase expression and activity, elastin degradation, and AAA formation, which was associated with reduced aortic inflammation and macrophage infiltration. In cultured vascular smooth muscle cells (VSMCs), rAAV-mediated CYP2J2 overexpression and EETs markedly suppressed Ang II-induced inflammatory cytokine expression. Moreover, overexpressed CYP2J2 and EETs inhibited Ang II-induced macrophage migration in a VSMC-macrophage coculture system. We further indicated that these protective effects were mediated by peroxisome proliferator-activated receptor (PPAR)γ activation. Taken together, these results provide evidence that rAAV-mediated CYP2J2 overexpression prevents AAA development which is likely via PPARγ activation and anti-inflammatory action, suggesting that increasing EETs levels could be considered as a potential strategy to prevent and treat AAA.

Let-7b Inhibits Human Cancer Phenotype by Targeting Cytochrome P450 Epoxygenase 2J2

BackgroundMicroRNAs (miRNAs) are small, noncoding RNA molecules of 20 to 22 nucleotides that regulate gene expression by binding to their 3′ untranslated region (3′UTR). Increasing data implicate altered miRNA participation in the progress of cancer. We previously reported that CYP2J2 epoxygenase promotes human cancer phenotypes. But whether and how CYP2J2 is regulated by miRNA is not understood.Methods and ResultsUsing bioinformatics analysis, we found potential target sites for miRNA let-7b in 3′UTR of human CYP2J2. Luciferase and western blot assays revealed that CYP2J2 was regulated by let-7b. In addition, let-7b decreased the enzymatic activity of endogenous CYP2J2. Furthermore, let-7b may diminish cell proliferation and promote cell apoptosis of tumor cells via posttranscriptional repression of CYP2J2. Tumor xenografts were induced in nude mice by subcutaneous injection of MDA-MB-435 cells. The let-7b expression vector, pSilencer-let-7b, was injected through tail vein every 3 weeks. Let-7b significantly inhibited the tumor phenotype by targeting CYP2J2. Moreover, quantitative real-time polymerase chain reaction and western blotting were used to determine the expression levels of let-7b and CYP2J2 protein from 18 matched lung squamous cell cancer and adjacent normal lung tissues; the expression level of CYP2J2 was inversely proportional to that of let-7b.ConclusionsOur results demonstrated that the decreased expression of let-7b could lead to the high expression of CYP2J2 protein in cancerous tissues. These findings suggest that miRNA let-7b reduces CYP2J2 expression, which may contribute to inhibiting tumor phenotypes.

Gene Delivery of Cytochrome P450 Epoxygenase Ameliorates Monocrotaline-Induced Pulmonary Artery Hypertension in Rats

Pulmonary arterial hypertension (PAH) is a life-threatening disease that leads to progressive pulmonary hypertension, right heart failure, and death. Endothelial dysfunction and inflammation were implicated in the pathogenesis of PAH. Epoxyeicosatrienoic acids (EETs), products of the cytochrome P450 epoxygenase metabolism of arachidonic acid, are potent vasodilators that possess anti-inflammatory and other protective properties in endothelial cells. We investigated whether gene delivery with the human cytochrome P450 epoxygenase 2J2 (CYP2J2) ameliorates monocrotaline (MCT)-induced pulmonary hypertension in rats. Significant pulmonary hypertension developed 3 weeks after the administration of MCT, but gene therapy with CYP2J2 significantly attenuated the development of pulmonary hypertension and pulmonary vascular remodeling, without causing changes in systemic arterial pressure or heart rate. These effects were associated with increased pulmonary endothelial NO synthase (eNOS) expression and its activity, inhibition of inflammation in the lungs, and transforming growth factor (TGF)-β/type II bone morphogenetic protein receptor (BMPRII)-drosophila mothers against decapentaplegic proteins (Smads) signaling. Collectively, these data suggest that gene therapy with CYP2J2 may have potential as a novel therapeutic approach to this progressive and oftentimes lethal disorder.

Cytochrome P450 (CYP) 2J2 gene transfection attenuates MMP‐9 via inhibition of NF‐κβ in hyperhomocysteinemia

Hyperhomocysteinemia (HHcy) is associated with atherosclerotic events involving the modulation of arachidonic acid (AA) metabolism and the activation of matrix metalloproteinase-9 (MMP-9). Cytochrome P450 (CYP) epoxygenase-2J2 (CYP2J2) is abundant in the heart endothelium, and its AA metabolites epoxyeicosatrienoic acids (EETs) mitigates inflammation through NF-kappabeta. However, the underlying molecular mechanisms for MMP-9 regulation by CYP2J2 in HHcy remain obscure. We sought to determine the molecular mechanisms by which P450 epoxygenase gene transfection or EETs supplementation attenuate homocysteine (Hcy)-induced MMP-9 activation. CYP2J2 was over-expressed in mouse aortic endothelial cells (MAECs) by transfection with the pcDNA3.1/CYP2J2 vector. The effects of P450 epoxygenase transfection or exogenous supplementation of EETs on NF-kappabeta-mediated MMP-9 regulation were evaluated using Western blot, in-gel gelatin zymography, electromobility shift assay, immunocytochemistry. The result suggested that Hcy downregulated CYP2J2 protein expression and dephosphorylated PI3K-dependent AKT signal. Hcy induced the nuclear translocation of NF-kappabeta via downregulation of IKbetaalpha (endogenous cytoplasmic inhibitor of NF-kappabeta). Hcy induced MMP-9 activation by increasing NF-kappabeta-DNA binding. Moreover, P450 epoxygenase transfection or exogenous addition of 8,9-EET phosphorylated the AKT and attenuated Hcy-induced MMP-9 activation. This occurred, in part, by the inhibition of NF-kappabeta nuclear translocation, NF-kappabeta-DNA binding and activation of IKbetaalpha. The study unequivocally suggested the pivotal role of EETs in the modulation of Hcy/MMP-9 signal.

Hydrogen Peroxide Inhibits Cytochrome P450 Epoxygenases

The cytochrome P450 epoxygenase (CYP)-derived metabolites of arachidonic acid the epoxyeicosatrienoic acids (EETs) and hydrogen peroxide (H2O2) both function as endothelium-derived hyperpolarizing factors (EDHFs) in the human coronary microcirculation. However, the relative importance of and potential interactions between these 2 vasodilators remain unexplored. We identified a novel inhibitory interaction between CYPs and H2O2 in human coronary arterioles, where EDHF-mediated vasodilatory mechanisms are prominent. Bradykinin induced vascular superoxide and H2O2 production in an endothelium-dependent manner and elicited a concentration-dependent dilation that was reduced by catalase but not by 14,15-epoxyeicosa-5(Z)-enoic acid (EEZE), 6-(2-propargyloxyphenyl)hexanoic acid, sulfaphenazole, or iberiotoxin. However, in the presence of catalase, an inhibitory effect of these compounds was unmasked. In a tandem-bioassay preparation, application of bradykinin to endothelium-intact donor vessels elicited dilation of downstream endothelium-denuded detectors that was partially inhibited by donor-applied catalase but not by detector-applied EEZE; however, EEZE significantly inhibited dilation in the presence of catalase. EET production by human recombinant CYP 2C9 and 2J2, 2 major epoxygenase isozymes expressed in human coronary arterioles, was directly inhibited in a concentration-dependent fashion by H2O2 in vitro, as observed by high-performance liquid chromatography (HPLC); however, EETs were not directly sensitive to oxidative modification. H2O2 inhibited dilation to arachidonic acid but not to 11,12-EET. These findings suggest that an inhibitory interaction exists between 2 EDHFs in the human coronary microcirculation. CYP epoxygenases are directly inhibited by H2O2, and this interaction may modulate vascular EET bioavailability.