EETs and CYP2J2 inhibit TNF-α-induced apoptosis in pulmonary artery endothelial cells and TGF-β1-induced migration in pulmonary artery smooth muscle cells

The involvement of soluble epoxide hydrolase in the development of cardiovascular diseases through epoxyeicosatrienoic acids

Arachidonic acid (AA) has three main metabolic pathways: the cycloxygenases (COXs) pathway, the lipoxygenases (LOXs) pathway, and the cytochrome P450s (CYPs) pathway. AA produces epoxyeicosatrienoic acids (EETs) through the CYPs pathway. EETs are very unstable in vivo and can be degraded in seconds to minutes. EETs have multiple degradation pathways, but are mainly degraded in the presence of soluble epoxide hydrolase (sEH). sEH is an enzyme of bifunctional nature, and current research focuses on the activity of its C-terminal epoxide hydrolase (sEH-H), which hydrolyzes the EETs to the corresponding inactive or low activity diol. Previous studies have reported that EETs have cardiovascular protective effects, and the activity of sEH-H plays a role by degrading EETs and inhibiting their protective effects. The activity of sEH-H plays a different role in different cells, such as inhibiting endothelial cell proliferation and migration, but promoting vascular smooth muscle cell proliferation and migration. Therefore, it is of interest whether the activity of sEH-H is involved in the initiation and progression of cardiovascular diseases by affecting the function of different cells through EETs.

MiR-3646 accelerates inflammatory response of Ang II-induced hVSMCs via CYP2J2/EETs axis in hypertension model

BACKGROUND

Inflammatory response of human vascular smooth muscle cells (hVSMCs) is a driving factor in hypertension progression. It has been reported that miR-3646 was significantly up-regulated in serum samples from patients with coronary artery disease and acute myocardial infarction mice. However, its role and underlying molecular mechanism related to inflammatory response of angiotensin II (Ang II)-induced hVSMCs remain unclear.

OBJECTIVE

We aimed to explore the potential molecular mechanisms related to inflammatory response of angiotensin II (Ang II)-induced hVSMCs.

METHODS

Ang II-induced hypertension model was established after hVSMCs treated with 1 μM Ang II at 24 h. The interaction between microRNA 3646 (miR-3646) and cytochrome P450 2J2 (CYP2J2) was assessed by dual-luciferase reporter gene assay. MTS assay, Lipid Peroxidation MDA Assay Kit, ELISA, Western blot, and qRT-PCR were performed to examine viability, malondialdehyde (MDA) level, inflammatory cytokine levels, and the level of genes and proteins.

RESULTS

Our findings illustrated that miR-3646 was up-regulated but CYP2J2 was down-regulated in Ang II-induced hVSMCs. Mechanically, miR-3646 negatively targeted to CYP2J2 in Ang II-induced hVSMCs. These findings indicated that miR-3646 regulated inflammatory response of Ang II-induced hVSMCs via targeting CYP2J2. Moreover, functional researches showed that CYP2J2 overexpression alleviated inflammatory response of Ang II-induced hVSMCs via epoxyeicosatrienoic acids/peroxisome proliferator-activated receptor-γ (EETs/PPARγ) axis, and miR-3646 aggravated inflammatory response of Ang II-induced hVSMCs via mediating CYP2J2/EETs axis.

CONCLUSION

MiR-3646 accelerated inflammatory response of Ang II-induced hVSMCs via CYP2J2/EETs axis. Our findings illustrated the specific molecular mechanism of miR-3646 regulating hypertension.

Integrated proteomics and metabolomics reveal variations in pulmonary fibrosis development and the potential therapeutic effect of Shuangshen Pingfei formula

ETHNOPHARMACOLOGICAL RELEVANCE

Shuangshen Pingfei formula (SSPF), a Chinese medicine prescription, has been prescribed to alleviate PF. However, little is known about the molecular mechanism underlying PF progression and the regulatory mechanism in SSPF.

AIMS OF THE STUDY

To discriminate the molecular alterations underlying the development of pulmonary fibrosis (PF) and reveal the regulatory mechanism of Shuangshen Pingfei formula (SSPF).

MATERIALS AND METHODS

An integrated analysis of a time-course pathology combined with proteomics and metabolomics was performed to investigate changes in body weight, survival rate, lung coefficient, histopathology, proteins, and metabolites of lung tissues at different time points upon bleomycin (BLM) exposure and SSPF treatment.

RESULTS

The results showed that PF progression was characterized by gradually aggravated fibrosis accompanied by inflammation with extended exposure (7, 14, and 21 days). SSPF significantly attenuated lung fibrosis, as evidenced by increased weight, and reduced lung coefficients and fibrosis scores. Moreover, 368 common differentially expressed proteins (DEPs) were identified, and 102 DEPs were continuously and monotonically upregulated via proteomics among the three BLM treatments. The DEPs were principally involved in extracellular matrix (ECM) remodeling and arginine and proline (AP) metabolic reprogramming. Additionally, metabolomics analyses revealed that BLM exposure mainly affected six metabolism pathways, including 34 differentially regulated metabolites (DRMs). Furthermore, correlation analysis found that several DEPs and DRMs, including L-ornithine, S-adenosyl-L-methionine, ARG, and AOC1, were associated with arginine and proline metabolism, and 8,9-EET, 8,9-DHET, CYP2B, etc., were involved in arachidonic acid (AA) metabolism, suggesting that these two pathways play a critical role in the development of fibrosis. After SSPF treatment, the related protein expression and metabolic disorders were regulated, implying that SSPF provides potential solutions to target these pathways for benefit in the treatment of PF.

CONCLUSION

Our data suggest that ECM remodeling, and metabolic reprogramming of AP and AA are distinctive features of PF development. Simultaneously, we confirmed that SSPF could effectively regulate metabolic disorders, indicating its potential clinical application for PF therapy. Our findings using multiple approaches provide a molecular-scale perspective on the mechanisms of PF progression and the amelioration of SSPF.

Epoxyeicosatrienoic acid administration or soluble epoxide hydrolase inhibition attenuates renal fibrogenesis in obstructive nephropathy

Epoxyeicosatrienoic acids (EETs) are arachidonic acid metabolites with biological effects, including antiapoptotic, anti-inflammatory, and antifibrotic functions. Soluble epoxide hydrolase (sEH)-mediated hydrolysis of EETs to dihydroxyeicosatrienoic acids (DHETs) attenuates these effects. Recent studies have demonstrated that inhibition of sEH prevents renal tubulointerstitial fibrosis and inflammation in the chronic kidney disease model. Given the pathophysiological role of the EET pathway in chronic kidney disease, we investigated if administration of EET regioisomers and/or sEH inhibition will promote antifibrotic and renoprotective effects in renal fibrosis following unilateral ureteral obstruction (UUO). EETs administration abolished tubulointerstitial fibrogenesis, as demonstrated by reduced fibroblast activation and collagen deposition after UUO. The inflammatory response was prevented as demonstrated by decreased neutrophil and macrophage infiltration and expression of cytokines in EET-administered UUO kidneys. EET administration and/or sEH inhibition significantly reduced M1 macrophage markers, whereas M2 macrophage markers were highly upregulated. Furthermore, UUO-induced oxidative stress, tubular injury, and apoptosis were all downregulated following EET administration. Combined EET administration and sEH inhibition, however, had no additive effect in attenuating inflammation and renal interstitial fibrogenesis after UUO. Taken together, our findings provide a mechanistic understanding of how EETs prevent kidney fibrogenesis during obstructive nephropathy and suggest EET treatment as a potential therapeutic strategy to treat fibrotic diseases.NEW & NOTEWORTHY Epoxyeicosatrienoic acids (EETs) are cytochrome P-450-dependent antihypertensive and anti-inflammatory derivatives of arachidonic acid, which are highly abundant in the kidney and considered renoprotective. We found that EET administration and/or soluble epoxide hydrolase inhibition significantly attenuates oxidative stress, renal cell death, inflammation, macrophage differentiation, and fibrogenesis following unilateral ureteral obstruction. Our findings provide a mechanistic understanding of how EETs prevent kidney fibrogenesis during obstructive nephropathy and suggest that EET treatment may be a potential therapeutic strategy to treat fibrotic diseases.

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.

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Cytochrome P450 epoxygenase-2J2 (CYP2J2) was first applied in the field of therapeutic angiogenesis for critical limb ischemia treatment.

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The ROS-responsive three-arm star block copolymer (3S-PLGA-po-PEG) was synthesized with peroxalate ester as H₂O₂-responsive linkages through the esterification reaction of oxalyl chloride and hydroxyl group.

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The CYP2J2 nano-delivery system achieved high transfection efficiency and significant therapeutic angiogenesis effect.

Caspase-4/11-Mediated Pulmonary Artery Endothelial Cell Pyroptosis Contributes to Pulmonary Arterial Hypertension

BACKGROUND

Endothelial dysfunction enhances vascular inflammation, which initiates pulmonary arterial hypertension (PAH) pathogenesis, further induces vascular remodeling and right ventricular failure. Activation of inflammatory caspases is an important initial event at the onset of pyroptosis. Studies have shown that caspase-1-mediated pyroptosis has played a crucial role in the pathogenesis of PAH. However, the role of caspase-11, another inflammatory caspase, remains to be elucidated. Therefore, the purpose of this study was to clarify the role of caspase-11 in the development of PAH and its mechanism on endothelial cell function.

METHODS

The role of caspase-11 in the progression of PAH and vascular remodeling was assessed in vivo. In vitro, the effect of caspase-4 silencing on the human pulmonary arterial endothelial cells pyroptosis was determined.

RESULTS

We confirmed that caspase-11 and its human homolog caspase-4 were activated in PAH animal models and TNF (tumor necrosis factor)-α-induced human pulmonary arterial endothelial cells. Caspase-11^-/- relieved right ventricular systolic pressure, right ventricle hypertrophy, and vascular remodeling in Sugen-5416 combined with chronic hypoxia mice model. Meanwhile, pharmacological inhibition of caspase-11 with wedelolactone exhibited alleviated development of PAH on the monocrotaline-induced rat model. Moreover, knockdown of caspase-4 repressed the onset of TNF-α-induced pyroptosis in human pulmonary arterial endothelial cells and inhibited the activation of pyroptosis effector GSDMD (gasdermin D) and GSDME (gasdermin E).

CONCLUSIONS

These observations identified the critical role of caspase-4/11 in the pyroptosis pathway to modulate pulmonary vascular dysfunction and accelerate the progression of PAH. Our findings provide a potential diagnostic and therapeutic target in PAH.

CYP2J2 and EETs protect against pulmonary arterial hypertension with lung ischemia-reperfusion injury in vivo and in vitro

Background

Cytochrome P450 epoxygenase 2J2 (CYP2J2) metabolizes arachidonic acid to epoxyeicosatrienoic acids (EETs), which exert anti-inflammatory, anti-apoptotic, pro-proliferative, and antioxidant effects on the cardiovascular system. However, the role of CYP2J2 and EETs in pulmonary arterial hypertension (PAH) with lung ischemia–reperfusion injury (LIRI) remains unclear. In the present study, we investigated the effects of CYP2J2 overexpression and exogenous EETs on PAH with LIRI in vitro and in vivo.

Methods

CYP2J2 gene was transfected into rat lung tissue by recombinant adeno-associated virus (rAAV) to increase the levels of EETs in serum and lung tissue. A rat model of PAH with LIRI was constructed by intraperitoneal injection of monocrotaline (50 mg/kg) for 4 weeks, followed by clamping of the left pulmonary hilum for 1 h and reperfusion for 2 h. In addition, we established a cellular model of human pulmonary artery endothelial cells (HPAECs) with TNF-α combined with anoxia/reoxygenation (anoxia for 8 h and reoxygenation for 16 h) to determine the effect and mechanism of exogenous EETs.

Results

CYP2J2 overexpression significantly reduced the inflammatory response, oxidative stress and apoptosis associated with lung injury in PAH with LIRI. In addition, exogenous EETs suppressed inflammatory response and reduced intracellular reactive oxygen species (ROS) production and inhibited apoptosis in a tumor necrosis factor alpha (TNF-α) combined hypoxia-reoxygenation model of HPAECs. Our further studies revealed that the anti-inflammatory effects of CYP2J2 overexpression and EETs might be mediated by the activation of PPARγ; the anti-apoptotic effects might be mediated by the PI3K/AKT pathway.

Conclusions

CYP2J2 overexpression and EETs protect against PAH with LIRI via anti-inflammation, anti-oxidative stress and anti-apoptosis, suggesting that increased levels of EETs may be a promising strategy for the prevention and treatment of PAH with LIRI.

Graphical Abstract

11,12 Epoxyeicosatrienoic Acid Rescues Deteriorated Wound Healing in Diabetes

Epoxyeicosatrienoic acids (EET) facilitate regeneration in different tissues, and their benefit in dermal wound healing has been proven under normal conditions. In this study, we investigated the effect of 11,12 EET on dermal wound healing in diabetes. We induced diabetes by i.p. injection of streptozotocin 2 weeks prior to wound creation on the dorsal side of the mouse ear. 11,12 EET was applied every second day on the wound, whereas the control groups received only solvent. Epithelialization was monitored every second day intravitally up to wound closure. Wounds were stained for VEGF, CD31, TGF-β, TNF-α, SDF-1α, NF-κB, and Ki-67, and fibroblasts were counted after hematoxylin-eosin stain on days 3, 6, 9, and 16 after wounding. After induction of diabetes, wounds closed on day 13.00 ± 2.20 standard deviation (SD). Local 11,12 ETT application improved wound closure significantly to day 8.40 ± 1.39 SD. EET treatment enhanced VEGF and CD31 expression in wounds on day 3. It also seemed to raise TNF-α level on all days investigated as well as TGF-β level on days 3 and 6. A decrease in NF-κB could be observed on days 9 and 16 after EET application. The latter findings were not significant. SDF-1α expression was not influenced by EET application, and Ki-67 was significantly less in the EET group on day 9 after EET application. The number of fibroblasts was significantly increased on day 9 after the 11,12 EET application. 11,12 EET improve deteriorated wound healing in diabetes by enhancing neoangiogenesis, especially in the early phase of wound healing. Furthermore, they contribute to the dissolution of the initial inflammatory reaction, allowing the crucial transition from the inflammatory to proliferative phase in wound healing.

Epoxyeicosatrienoic Acids and Fibrosis: Recent Insights for the Novel Therapeutic Strategies

Organ fibrosis often ends in eventual organ failure and leads to high mortality. Although researchers have identified many effector cells and molecular pathways, there are few effective therapies for fibrosis to date and the underlying mechanism needs to be examined and defined further. Epoxyeicosatrienoic acids (EETs) are endogenous lipid metabolites of arachidonic acid (ARA) synthesized by cytochrome P450 (CYP) epoxygenases. EETs are rapidly metabolized primarily via the soluble epoxide hydrolase (sEH) pathway. The sEH pathway produces dihydroxyeicosatrienoic acids (DHETs), which have lower activity. Stabilized or increased EETs levels exert several protective effects, including pro-angiogenesis, anti-inflammation, anti-apoptosis, and anti-senescence. Currently, intensive investigations are being carried out on their anti-fibrotic effects in the kidney, heart, lung, and liver. The present review provides an update on how the stabilized or increased production of EETs is a reasonable theoretical basis for fibrosis treatment.

Alginate Oligosaccharide Alleviates Monocrotaline-Induced Pulmonary Hypertension via Anti-Oxidant and Anti-Inflammation Pathways in Rats

Pulmonary arterial hypertension (PAH) is a serious and fatal cardiovascular disorder characterized by increased pulmonary vascular resistance and progressive pulmonary vascular remodeling. The underlying pathological mechanisms of PAH are multi-factorial and multi-cellular. Alginate oligosaccharide (AOS), which is produced by depolymerizing alginate, shows better pharmacological activities and beneficial effects. The present study was undertaken to investigate the effects and potential mechanisms of AOS-mediated alleviation of pulmonary hypertension. Pulmonary hypertension was induced in Sprague-Dawley rats by a single intraperitoneal injection of monocrotaline (MCT; 60 mg/kg). Five weeks after the injection of MCT, AOS (5, 10, and 20 mg·kg^-1·d^-1) was injected intraperitoneally for another three weeks. The results showed that AOS prevented the development of MCT-induced pulmonary hypertension and right ventricular hypertrophy in a dose-dependent manner. AOS treatment also prevented MCT-induced pulmonary vascular remodeling via inhibition of the TGF-β1/p-Smad2 signaling pathway. Furthermore, AOS treatment downregulated the expression of malondialdehyde, nicotinamide adenine dinucleotide phosphate oxidase, and pro-inflammatory cytokines, decreased macrophage infiltration, and upregulated the expression of anti-inflammatory cytokines. These findings indicate that AOS exerts anti-oxidative and anti-inflammatory effects in pulmonary arteries, which may contribute to the alleviation of pulmonary hypertension and pulmonary vascular remodeling.

Angiogenesis and vascular stability in eicosanoids and cancer

Angiogenesis and inflammation are hallmarks of cancer. Arachidonic acid and other polyunsaturated fatty acids (PUFAs) are primarily metabolized by three distinct enzymatic systems initiated by cyclooxygenases, lipoxygenases, and cytochrome P450 enzymes (CYP) to generate bioactive eicosanoids, including prostanoids, leukotrienes, hydroxyeicosatetraenoic acids, and epoxyeicosatrienoic acids. As some of the PUFA metabolites playing essential roles in inflammatory processes, these pathways have been widely studied as therapeutic targets of inflammation. Because of their anti-inflammatory effects, these pathways were also proposed as anti-cancer targets. However, although the eicosanoids were linked to endothelial cell proliferation and angiogenesis almost two decades ago, it is only recently PUFA metabolites, especially those generated by CYP enzymes and the soluble epoxide hydrolase (sEH), have been recognized as important signaling mediators in physiological and pathological angiogenesis. Despite the fact that tumor growth and invasion are heavily dependent on inner-tumor angiogenesis and influenced by vascular stability, the role played by PUFA metabolites in tumor angiogenesis and vessel integrity has been largely overlooked. This review highlights current knowledge on the function of PUFA metabolites generated by the CYP/sEH pathway in angiogenesis and vascular stability as well as their potential involvement in cancer development.

Interleukin-10 attenuates impairment of the blood-brain barrier in a severe acute pancreatitis rat model

Background

Impairment of the blood-brain barrier (BBB) in severe acute pancreatitis (SAP) could result in life-threatening pancreatic encephalopathy. Interleukin-10 (IL-10) is a classical cytokine that is well-known for its strong immunoregulatory and anti-inflammatory abilities. However, whether and how IL-10 protects the BBB in SAP are still unclear.

Methods

This study includes in vivo experiments using a SAP rat model and in vitro experiments using an in vitro BBB model consisting of a monolayer of brain microvascular endothelial cells (BMECs). The study groups are divided into the control, SAP (in vivo)/TNF-α (in vitro), IL-10 treatment, IL-10 + signal transducer and activator of transcription 3 (STAT3) inhibitor S3I-201 treatment groups. Pancreatic pathological scores, serum amylase, serum TNF-α levels and BBB permeability by Evan’s blue assay in SAP rat models were evaluated. BMEC apoptosis in SAP rats or induced by TNF-αin vitro was detected by terminal-deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) and flow cytometry, separately. Expression levels of claudin-5 and proteins involved in the STAT3 signaling pathway were measured by Western blotting. Location and changes of junctional structure of claudin-5 on BMECs were assessed by immunohistochemistry and immunofluorescence.

Results

In vivo, IL-10 alleviated the severity of inflammation, attenuated the increased BBB permeability in SAP rat models by reducing BMEC apoptosis via the STAT3 pathway and ameliorated the down-regulation of claudin-5 expression in BMECs; in vitro, IL-10 improved BBB integrity against TNF-α by attenuating BMEC apoptosis via the STAT3 pathway, the impairment of tight junction structure and the down-regulation of claudin-5 expression in BMECs.

Conclusions

IL-10 improves BBB properties in SAP by attenuating the down-regulation of claudin-5 expression and the impairment of tight junctions and by STAT3 pathway-mediated anti-apoptotic effects on BMECs.

The transient receptor potential vanilloid-3 regulates hypoxia-mediated pulmonary artery smooth muscle cells proliferation via PI3K/AKT signaling pathway

OBJECTVES

Transient receptor potential vanilloid 3 (TRPV3) is a member of the TRP channels family of Ca²⁺ -permeant cation channels. In this study, we aim to investigate the role of TRPV3 in pulmonary vascular remodeling and PASMCs proliferation under hypoxia.

MATERIALS AND METHODS

The expression of TRPV3 was evaluated in patients with pulmonary arterial hypertension (PAH) and hypoxic rats, using hematoxylin and eosin (H&E) and immunohistochemistry. In vitro, MTT assay, flow cytometry, Western blotting and immunofluorescence were performed to investigate the effects of TRPV3 on proliferation of PASMCs.

RESULTS

We found that, in vivo, the expression of TRPV3 was increased in patients with PAH and hypoxic rats. Right ventricular hypertrophy measurements and pulmonary pathomorphology data show that the ratio of the heart weight/tibia length (HW/TL), the right ventricle/left ventricle plus septum (RV/LV+S) and the medial width of the pulmonary artery were increased in chronic hypoxic rats. Moreover, the expression of proliferating cell nuclear antigen (PCNA), Cyclin D, Cyclin E and Cyclin A, phospho-CaMKII (p-CaMKII) were induced by hypoxia. In vitro, we revealed that hypoxia promoted PASMCs viability, increased the expression of PCNA, Cyclin D, Cyclin E, Cyclin A p-CaMKII, made more cells from G₀ /G₁ phase to G₂ /M + S phase, enhanced the microtubule formation, and increased [Ca²⁺ ]_i , which could be suppressed by Ruthenium Red, an inhibitor of TRPV3, and TRPV3 silencing has similar effects. Furthermore, the up-regulated expression of PCNA, Cyclin D, Cyclin E and Cyclin A, the increased number of cells in G₂ /M and S phase, and the enhanced activation and expression of PI3K and AKT proteins induced by hypoxia and in presence of carvacrol (an agonist of TRPV3), was significantly attenuated by incubation of LY 294002, a specific inhibitor for PI3K/AKT.

CONCLUSIONS

These findings suggest that TRPV3 is involved in hypoxia-induced pulmonary vascular remodeling and promotes proliferation of PASMCs and the effect is, at least in part, mediated via the PI3K/AKT pathway.

Inhibition of soluble epoxide hydrolase attenuates eosinophil recruitment and food allergen-induced gastrointestinal inflammation

Prevalence of food allergies in the United States is on the rise. Eosinophils are recruited to the intestinal mucosa in substantial numbers in food allergen-driven gastrointestinal (GI) inflammation. Soluble epoxide hydrolase (sEH) is known to play a pro-inflammatory role during inflammation by metabolizing anti-inflammatory epoxyeicosatrienoic acids (EETs) to pro-inflammatory diols. We investigated the role of sEH in a murine model of food allergy and evaluated the potential therapeutic effect of a highly selective sEH inhibitor (trans-4-{4-[3-(4-trifluoromethoxyphenyl)-ureido]-cyclohexyloxy}-benzoic acid [t-TUCB]). Oral exposure of mice on a soy-free diet to soy protein isolate (SPI) induced expression of intestinal sEH, increased circulating total and antigen-specific IgE levels, and caused significant weight loss. Administration of t-TUCB to SPI-challenged mice inhibited IgE levels and prevented SPI-induced weight loss. Additionally, SPI-induced GI inflammation characterized by increased recruitment of eosinophils and mast cells, elevated eotaxin 1 levels, mucus hypersecretion, and decreased epithelial junction protein expression. In t-TUCB-treated mice, eosinophilia, mast cell recruitment, and mucus secretion were significantly lower than in untreated mice and SPI-induced loss of junction protein expression was prevented to variable levels. sEH expression in eosinophils was induced by inflammatory mediators TNF-α and eotaxin-1. Treatment of eosinophils with t-TUCB significantly inhibited eosinophil migration, an effect that was mirrored by treatment with 11,12-EET, by inhibiting intracellular signaling events such as ERK (1/2) activation and eotaxin-1-induced calcium flux. These studies suggest that sEH induced by soy proteins promotes allergic responses and GI inflammation including eosinophilia and that inhibition of sEH can attenuate these responses.

Soluble Epoxide Hydrolase Inhibition Protected against Angiotensin II-induced Adventitial Remodeling

Epoxyeicosatrienoic acids (EETs), the metabolites of cytochrome P450 epoxygenases derived from arachidonic acid, exert important biological activities in maintaining cardiovascular homeostasis. Soluble epoxide hydrolase (sEH) hydrolyzes EETs to less biologically active dihydroxyeicosatrienoic acids. However, the effects of sEH inhibition on adventitial remodeling remain inconclusive. In this study, the adventitial remodeling model was established by continuous Ang II infusion for 2 weeks in C57BL/6 J mice, before which sEH inhibitor 1-trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl) urea (TPPU) was administered by gavage. Adventitial remodeling was evaluated by histological analysis, western blot, immunofluorescent staining, calcium imaging, CCK-8 and transwell assay. Results showed that Ang II infusion significantly induced vessel wall thickening, collagen deposition, and overexpression of α-SMA and PCNA in aortic adventitia, respectively. Interestingly, these injuries were attenuated by TPPU administration. Additionally, TPPU pretreatment overtly prevented Ang II-induced primary adventitial fibroblasts activation, characterized by differentiation, proliferation, migration, and collagen synthesis via Ca²⁺-calcineurin/NFATc3 signaling pathway in vitro. In summary, our results suggest that inhibition of sEH could be considered as a novel therapeutic strategy to treat adventitial remodeling related disorders.

Correlations of CYP2C9*3/CYP2D6*10/CYP3A5*3 gene polymorphisms with efficacy of etanercept treatment for patients with ankylosing spondylitis: A case-control study

BACKGROUND

The tumor necrosis factor alpha (TNF-α) inhibitor etanercept has been proven to be effective in the treatment of ankylosing spondylitis (AS), while genetic polymorphism may affect drug metabolism or drug receptor, resulting in interindividual variability in drug disposition and efficacy. The purpose of this study is to investigate the correlations between CYP2C9*3/CYP2D6*10/CYP3A5*3 gene polymorphisms and the efficacy of etanercept treatment for patients with AS.

METHODS

From March 2012 to June 2015, 312 AS patients (174 males and 138 females, mean age: 35.2 ± 5.83 years) from 18 to 56 years old were enrolled in this study. Polymerase chain reaction-restriction fragment length polymorphism was applied to detect the allele and genotype frequencies of CYP2C93, CYP2D610, and CYP3A53 gene polymorphisms. The joint swelling score, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) level of AS patients were compared before and after 24-week etanercept treatment. Assessment in Ankylosing Spondylitis (ASAS) and bath ankylosing spondylitis disease activity index (BASDAI) scores were recorded to assess the efficacy of etanercept treatment.

RESULTS

The AS patients with wild-type 1/1 and heterozygous 1/3 genotypes of CYP2C93 polymorphism accounted for 93.59% and 6.41%, respectively, without 3/3 genotype. The AS patients with wild-type CC, heterozygous CT, and mutation homozygous TT genotypes of CYP2D610 polymorphism accounted for 19.23%, 39.10%, and 41.67%, respectively. The AS patients with wild-type 1/1, heterozygous 1/3, and mutation homozygous 3/3 genotypes of CYP3A53 polymorphism accounted for 7.69%, 36.22%, and 56.09%, respectively. After 24-week treatment, AS patients with wild-type 1/1 genotype of CYP2C93, CC genotype of CYP2D610, and 3/3 genotype of CYP3A53 polymorphisms had lower joint swelling score, ESR, and CRP level. The joint swelling score, ESR, and CRP levels were significantly lower in the patients with CC genotype of CYP2D610 polymorphism than in CT and TT genotype patients, and they were lower in patients with 3/3 genotype of CYP3A53 polymorphism compared to those with 1/1 and 1/3 genotypes. Average visual analog scale scores of 4 ASAS20 indexes were decreased after treatment. The patients with CC genotype of CYP2D610 polymorphism and 3/3 genotype of CYP3A53 polymorphism exhibited higher scores of >ASAS20, >BASDAI50%, and effective rate.

CONCLUSION

Our results indicate that CC genotype of CYP2D610 polymorphism and 33 genotype of CYP3A53 polymorphism are correlated with the efficacy of etanercept treatment for AS patients.

The epoxyeicosatrienoic acid analog PVPA ameliorates cyclosporine-induced hypertension and renal injury in rats

The introduction of calcineurin inhibitors (CNI) into clinical practice in the late 1970s transformed organ transplantation and led to significant improvement in acute rejection episodes. However, despite their significant clinical utility, the use of these agents is hampered by the development of hypertension and nephrotoxicity, which ultimately lead to end-stage kidney disease and overt cardiovascular outcomes. There are currently no effective agents to treat or prevent these complications. Importantly, CNI-free immunosuppressive regimens lack the overall efficacy of CNI-based treatments and put patients at risk of allograft rejection. Cytochrome P-450 epoxygenase metabolites of arachidonic acid, epoxyeicosatrienoic acids (EETs), have potent vasodilator and antihypertensive properties in addition to many cytoprotective effects, but their effects on CNI-induced nephrotoxicity have not been explored. Here, we show that PVPA, a novel, orally active analog of 14,15-EET, effectively prevents the development of hypertension and ameliorates kidney injury in cyclosporine-treated rats. PVPA treatment reduced proteinuria and renal dysfunction induced by cyclosporine. PVPA inhibited inflammatory cell infiltration into the kidney and decreased renal fibrosis. PVPA also reduced tubular epithelial cell apoptosis, attenuated the generation of reactive oxygen species, and modulated the unfolded protein response that is associated with endoplasmic reticulum stress. Consistent with the in vivo data, PVPA attenuated cyclosporine-induced apoptosis of NRK-52E cells in vitro. These data indicate that the cytochrome P-450/EET system offers a novel therapeutic strategy to treat or prevent CNI-induced nephrotoxicity.

Marmoset cytochrome P450 2J2 mainly expressed in small intestines and livers effectively metabolizes human P450 2J2 probe substrates, astemizole and terfenadine

1. Common marmoset (Callithrix jacchus), a New World Monkey, has potential to be a useful animal model in preclinical studies. However, drug metabolizing properties have not been fully understood due to insufficient information on cytochrome P450 (P450), major drug metabolizing enzymes. 2. Marmoset P450 2J2 cDNA was isolated from marmoset livers. The deduced amino acid sequence showed a high-sequence identity (91%) with cynomolgus monkey and human P450 2J2 enzymes. A phylogenetic tree revealed that marmoset P450 2J2 was evolutionarily closer to cynomolgus monkey and human P450 2J2 enzymes, than P450 2J forms in pigs, rabbits, rats or mice. 3. Marmoset P450 2J2 mRNA was abundantly expressed in the small intestine and liver, and to a lesser extent in the brain, lung and kidney. Immunoblot analysis also showed expression of marmoset P450 2J2 protein in the small intestine and liver. 4. Enzyme assays using marmoset P450 2J2 protein heterologously expressed in Escherichia coli indicated that marmoset P450 2J2 effectively catalyzed astemizole O-demethylation and terfenadine t-butyl hydroxylation, similar to human and cynomolgus monkey P450 2J2 enzymes. 5. These results suggest the functional characteristics of P450 2J2 enzymes are similar among marmosets, cynomolgus monkeys and humans.

Sex- and isoform-specific mechanism of neuroprotection by transgenic expression of P450 epoxygenase in vascular endothelium

OBJECTIVE

Cytochrome P450 epoxygenases (CYP) metabolize arachidonic acid to epoxyeicosatrienoic acids (EETs), which exhibit vasodilatory, anti-inflammatory and neuroprotective actions in experimental cerebral ischemia. We evaluated the effect of endothelial-specific CYP overexpression on cerebral blood flow, inflammatory cytokine expression and tissue infarction after focal cerebral ischemia in transgenic mice.

APPROACH AND RESULTS

Male and female wild-type and transgenic mice overexpressing either human CYP2J2 or CYP2C8 epoxygenases in vascular endothelium under control of the Tie2 promoter (Tie2-CYP2J2 and Tie2-CYP2C8) were subjected to 60-min middle cerebral artery occlusion (MCAO). Microvascular cortical perfusion was monitored during vascular occlusion and reperfusion using laser-Doppler flowmetry and optical imaging. Infarct size and inflammatory cytokines were measured at 24h of reperfusion by TTC and real-time quantitative PCR, respectively. Infarct size was significantly reduced in both Tie2-CYP2J2 and Tie2-CYP2C8 transgenic male mice compared to corresponding WT male mice (n=10 per group, p<0.05). Tie2-CYP2J2, but not Tie2-CYP2C8 male mice maintained higher blood flow during MCAO; however, both Tie2-CYP2J2 and Tie2-CYP2C8 had lower inflammatory cytokine expression after ischemia compared to corresponding WT males (n=10 per group for CBF and n=3 for cytokines, p<0.05). In females, a reduction in infarct was observed in the caudate-putamen, but not in the cortex or hemisphere as a whole and no differences were observed in blood flow between female transgenic and WT mice (n=10 per group).

CONCLUSIONS

Overexpression of CYP epoxygenases in vascular endothelial cells protects against experimental cerebral ischemia in male mice. The mechanism of protection is in part linked to enhanced blood flow and suppression of inflammation, and is both sex- and CYP isoform-specific.

Soluble epoxide hydrolase inhibitor 1-trifluoromethoxyphenyl-3- (1-propionylpiperidin-4-yl) urea attenuates bleomycin-induced pulmonary fibrosis in mice

Epoxyeicosatrienoic acids (EETs), the metabolites of arachidonic acid derived from the cytochrome P450 (CYP450) epoxygenases, are mainly metabolized by soluble epoxide hydrolase (sEH) to their corresponding diols. EETs but not their diols, have anti-inflammatory properties and inhibition of sEH might provide protective effects against inflammatory fibrosis. We test the effects of a selected sEH inhibitor, 1-trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl) urea (TPPU), on bleomycin-induced pulmonary fibrosis (PF) in mice. A mouse model of PF was established by intratracheal injection of bleomycin and TPPU was administered for 21 days after bleomycin injection. We found TPPU treatment improved the body weight loss and survival rate of bleomycin-stimulated mice. Histological examination showed that TPPU treatment alleviated bleomycin-induced inflammation and maintained the alveolar structure of the pulmonary tissues. TPPU also decreased the bleomycin-induced deposition of collagen and the expression of procollagen I mRNA in lung tissues of mice. TPPU decreased the transforming growth factor-β1 (TGF-β1), interleukin-1β (IL-1β) and IL-6 levels in the serum of bleomycin-stimulated mice. Furthermore, TPPU inhibited the proliferation and collagen synthesis of mouse fibroblasts and partially reversed TGF-β1-induced α-smooth muscle actin expression. Our results indicate that the inhibition of sEH attenuates bleomycin-induced inflammation and collagen deposition and therefore prevents bleomycin-induced PF in a mouse model.

Aberrant soluble epoxide hydrolase and oxylipin levels in a porcine arteriovenous graft stenosis model

Synthetic arteriovenous grafts (AVGs) used for hemodialysis frequently fail due to the development of neointimal hyperplasia (NH) at the vein-graft anastomosis. Inflammation and smooth-muscle cell (SMC) and myofibroblast proliferation and migration likely play an important role in the pathogenesis of NH. Epoxyeicosatrienoic acids (EETs), the products of the catabolism of arachidonic acid by cytochrome P450 enzymes, possess anti-inflammatory, antiproliferative, antimigratory and vasodilatory properties that should reduce NH. The degradation of vasculoprotective EETs is catalyzed by the enzyme, soluble epoxide hydrolase (sEH). sEH upregulation may thus contribute to NH development by the enhanced removal of vasculoprotective EETs. In this study, sEH, cytochrome P450 and EETs were examined after AVG placement in a porcine model to explore their potential roles in AVG stenosis. Increased sEH protein expression, decreased P450 epoxygenase activity and dysregulation of 5 oxylipin mediators were observed in the graft-venous anastomotic tissues when compared to control veins. Pharmacological inhibitors of sEH decreased the growth factor-induced migration of SMCs and fibroblasts, although they had no significant effect on the proliferation of these cells. These results provide insights on epoxide biology in vascular disorders and a rationale for the development of novel pharmacotherapeutic strategies to prevent AVG failure due to NH and stenosis.

Death receptor 3 mediates TNFSF15- and TNFα-induced endothelial cell apoptosis

Tumor necrosis factor superfamily 15 (TNFSF15) suppresses angiogenesis by specifically inducing apoptosis in proliferating endothelial cells. Death receptor 3 (DR3), a member of the TNF receptor superfamily (TNFRSF25), has been identified as a receptor for TNFSF15 to activate T cells. It is unclear, however, whether DR3 mediates TNFSF15 activity on endothelial cells. Here we show that siRNA-mediated knockdown of DR3 in an in vivo Matrigel angiogenesis assay, or in adult bovine aortic endothelial (ABAE) cell cultures, leads to resistance of endothelial cells to TNFSF15-induced apoptosis. Interestingly, DR3-depleted cells also exhibited markedly diminished responsiveness to TNFα cytotoxicity, even though DR3 is not a receptor for TNFα. Treatment of the cells with either TNFSF15 siRNA or a TNFSF15-neutralizing antibody, 4-3H, also results in a significant inhibition of TNFα-induced apoptosis. Mechanistically, DR3 siRNA treatment gives rise to an increase of ERK1/2 MAPK activity, and up-regulation of the anti-apoptotic proteins c-FLIP and Bcl-2, thus strengthening apoptosis-resisting potential in the cells. These findings indicate that DR3 mediates TNFSF15-induced endothelial cell apoptosis, and that up-regulation of TNFSF15 expression stimulated by TNFα is partly but significantly responsible for TNFα-induced apoptosis in endothelial cells.

Epoxyeicosatrienoic acids attenuating hypotonic-induced apoptosis of IMCD cells via γ-ENaC inhibition

Inner medulla collecting duct (IMCD) cells are the key part for urinary concentration. Hypotonic stress may trigger apoptosis of IMCD cells and induce renal injury. Epoxyeicosatrienoic acids (EETs) play an important role in anti-apoptosis, but their roles in hypotonic-induced apoptosis of IMCD cells are still unclear. Here we found increasing exogenous 11, 12-EET or endogenous EETs with Ad-CMV-CYP2C23-EGFP transfection decreased apoptosis of IMCD cells induced by hypotonic stress. Moreover, up-regulation of γ-ENaC induced by hypotonic stress was abolished by elevation of exogenous or endogenous EETs. Collectively, this study illustrated that EETs attenuated hypotonic-induced apoptosis of IMCD cells, and that regulation of γ-ENAC may be a possible mechanism contributing to the anti-apoptotic effect of EETs in response to hypotonic stress.

EETs alleviate ox-LDL-induced inflammation by inhibiting LOX-1 receptor expression in rat pulmonary arterial endothelial cells

Oxidized low-density lipoprotein (Ox-LDL) is associated with atherosclerotic events through the modulation of arachidonic acid (AA) metabolism and activation of inflammatory signaling. Cytochrome P450 (CYP) epoxygenase-derived epoxyeicosatrienoic acids (EETs) mitigate inflammation through nuclear factor-κB (NF-κB). In this study, we explored the effects and mechanisms of exogenous EETs on the ox-LDL-induced inflammation of pulmonary artery endothelial cells (PAECs), which were cultured from rat pulmonary arteries. We determined that pre-treatment with 11,12-EET or 14,15-EET attenuated the ox-LDL-induced expression and release of intercellular adhesion molecule-1 (ICAM-1), E-selectin, and monocyte chemoattractant protein-1 (MCP-1) in a concentration-dependent manner. In addition, the ox-LDL-induced expression of CYP2J4 was upregulated by 11,12-EET and 14,15-EET (1μM). Furthermore, the endothelial receptor of lectin-like oxidized low-density lipoprotein (LOX-1) was downregulated in PAECs treated with EETs. The inflammatory responses evoked by ox-LDL (100μg/mL) were blocked by pharmacological inhibitors of Erk1/2 mitogen-activated protein kinase (MAPK) (U0126), p38 MAPK (SB203580), and NF-κB (PDTC). In addition, we confirmed that 11,12-EET suppresses phosphorylation of p38, degradation of IκBα, and activation of NF-κB (p65), whereas 14,15-EET can significantly suppress the phosphorylation of p38 and Erk1/2. Our results indicate that EETs exert beneficial effects on ox-LDL-induced inflammation primarily through the inhibition of LOX-1 receptor upregulation, MAPK phosphorylation, and NF-κB activation and through the upregulation of CYP2J4 expression. This study helps focus the current understanding of the contribution of EETs to the regulation of the inflammation of pulmonary vascular endothelial cells. Furthermore, the therapeutic potential of targeting the EET pathway in pulmonary vascular disease will be highlighted.