Reversal of SIN-1-induced eNOS dysfunction by the spin trap,DMPO, in bovine aortic endothelial cells via eNOS phosphorylation

Background and Purpose

Nitric oxide (NO) derived from eNOS is mostly responsible for the maintenance of vascular homeostasis and its decreased bioavailability is characteristic of reactive oxygen species (ROS)-induced endothelial dysfunction (ED). Because 5,5-dimethyl-1-pyrroline-N-oxide (DMPO), a commonly used spin trap, can control intracellular nitroso-redox balance by scavenging ROS and donating NO, it was employed as a cardioprotective agent against ED but the mechanism of its protection is still not clear. This study elucidated the mechanism of protection by DMPO against SIN-1-induced oxidative injury to bovine aortic endothelial cells (BAEC).

Experimental Approach

BAEC were treated with SIN-1, as a source of peroxynitrite anion (ONOO⁻), and then incubated with DMPO. Cytotoxicity following SIN-1 alone and cytoprotection by adding DMPO was assessed by MTT assay. Levels of ROS and NO generation from HEK293 cells transfected with wild-type and mutant eNOS cDNAs, tetrahydrobiopterin bioavailability, eNOS activity, eNOS and Akt kinase phosphorylation were measured.

Key Results

Post-treatment of cells with DMPO attenuated SIN-1-mediated cytotoxicity and ROS generation, restoration of NO levels via increased in eNOS activity and phospho-eNOS levels. Treatment with DMPO alone significantly increased NO levels and induced phosphorylation of eNOS Ser¹¹⁷⁹ via Akt kinase. Transfection studies with wild-type and mutant human eNOS confirmed the dual role of eNOS as a producer of superoxide anion (O₂⁻) with SIN-1 treatment, and a producer of NO in the presence of DMPO.

Conclusion and Implications

Post-treatment with DMPO of oxidatively challenged cells reversed eNOS dysfunction and could have pharmacological implications in the treatment of cardiovascular diseases.     

男性高血压患者血尿酸与勃起功能障碍及血管内皮损伤的关系#br#

摘要：目的　探讨男性高血压患者血清尿酸（UA）水平变化及其与勃起功能障碍（ED）和血管内皮损伤指标一氧化氮（NO）、内皮型一氧化氮合酶（eNOS）和内皮微粒（EMP）的关系。方法　选择新诊断男性高血压患者为研究对象,采用ED国际指数问卷表-5（IIEF-5）评估ED及其严重程度,100例伴ED患者（轻度31例、中度34例、重度35例）为ED组,100例年龄配对无ED的患者为对照组,尿酸酶法测定血清UA,酶联免疫法测定NO、eNOS,流式细胞技术测定血浆EMP水平。结果　重度ED组UA和EMP高于其他各组;而NO和eNOS低于其他各组,中度ED组UA和EMP高于轻度组及对照组;而NO和eNOS低于轻度组及对照组,轻度组UA和EMP高于对照组;而NO和eNOS低于对照组（P＜0.05）。相关分析表明高血压患者UA与NO、eNOS呈负相关,与EMP呈正相关（r分别为-0.589、-0.693和0.717,均P＜0.01）。多元逐步回归分析结果显示高血压患者UA、低密度脂蛋白胆固醇（LDL-C）、收缩压、糖尿病为EMP的影响因素,多元Logistic回归分析显示UA、舒张压、BMI及LDL-C为高血压患者ED的独立影响因素（P＜0.01）,血清UA预测高血压伴ED的ROC曲线下面积为0.785（95%CI：0.717～0.852,P＜0.01）。以血清UA 384.5 µmol/L作为预测ED最佳阈值时,敏感度90%,特异度69%,阳性预测值74.8%,阴性预测值87.3%。结论　高血压合并ED患者血清UA水平增高,高尿酸血症可能通过损伤血管内皮功能促使高血压患者ED发生与发展。     

Effect of vascular endothelial growth factor and epidermal growth factor on iatrogenic apoptosis in human endothelial cells

To study the effect of growth factors on iatrogenic apoptosis, we examined the influence of vascular endothelial growth factor (VEGF) and epidermal growth factor (EGF) on staurosporine-induced apoptosis in primary cultures of human umbilical vein endothelial cells (HUVEC). Apoptosis was evaluated by a cell viability test, the TUNEL-POD assay and the activation of the pro-apoptotic caspase-3. Staurosporine (10-100nM) caused the activation of caspase-3. This effect was manifest after 2hr of incubation and reached its maximum after 5hr. Severe loss of viability followed within 18hr. VEGF or EGF (10-100ng/mL) added together with staurosporine decreased the activation of caspase-3. The loss of viability was 24hr delayed. The action of growth factors was observed at 1% serum concentration but also at concentration optimal for HUVEC survival (10%, v/v). Furthermore, the inhibition of PI-3 kinase (PI-3K) by wortmannin or LY294002 as well as the inhibition of MEK by PD098059 or U0126 prevented the protective effect of VEGF and EGF. Western blotting analysis showed that after 3hr of incubation with staurosporine the level of the anti-apoptotic protein Mcl-1 decreased and this effect was reverted by VEGF. It is concluded that VEGF and EGF antagonize the pro-apoptotic action of staurosporine by the combined signalling of PI-3K and ERKs pathways.     

过敏性紫癜患儿血浆血管内皮生长因子、内皮素-1变化及临床意义

目的探讨过敏性紫癜（HSP）患儿血浆血管内皮生长因子（VEGF）及内皮素-1（ET-1）的水平变化及其在HSP发病与肾损害严重程度中的作用。方法采用ELISA及同位素放免法分别检测38例HSP患儿、40例紫癜性肾炎患儿（HSPN）及16例正常儿童血浆VEGF、ET-1水平。结果（1）HSP、HSPN患儿血浆VEGF、ET-1浓度均高于正常儿童（p〈0．01）。（2）HSPN患儿其血浆VEGF、ET-1浓度高于HSP组（P〈0．01）。（3）HSPN患儿其血浆VEGF、ET-1浓度与肾脏病理损害及血管损害呈正相关（P〈0．01）。结论VEGF和ET-1在儿童HSP的发生与发展中发挥一定的作用，血浆VEGF和ET-1浓度动态变化可用于评价HSPN患儿肾组织损伤程度。     

血管内皮生长因子及微血管密度在肝癌中的表达

目的探讨原发性肝癌中血管内皮生长因子(VEGF)和微血管密度(MVD)的表达。方法选择60例原发性肝癌手术标本,采用免疫组织化学染色方法检测VEGF及Ⅷ因子的表达。结果VEGF在原发性肝癌中的阳性表达率为63·3%;原发性肝癌中MVD为(30·76±11·56),其中VEGF表达阳性者MVD为(46·37±15·85),VEGF表达阴性者MVD为(18·97±8·68),两者差异有统计学意义(P<0·01)。VEGF的表达与肿瘤的大小和有无门脉癌栓明显相关(P<0·01),而与肿瘤有无包膜、分化程度、AFP水平、HBsAg阳性无关(P>0·05)。结论VEGF能促进肿瘤中微血管的形成,与原发性肝癌的生长、浸润和转移有关。     

Adenosine modulates vascular endothelial growth factor expression via hypoxia-inducible factor-1 in human glioblastoma cells

Hypoxia appears to induce a program which shifts the cellular phenotype toward an increase in extracellular adenosine. Hypoxia-inducible factor-1 (HIF-1) is a key regulator of genes crucial to many aspects of cancer biology. Since in gliomas there is a strong correlation between HIF-1alpha expression, tumor grade and tumor vascularization, the aim of this study was to investigate whether adenosine may regulate HIF-1 in human glioblastoma cell lines. The results indicate that in the human hypoxic A172 and U87MG glioblastoma cell lines adenosine up-regulates HIF-1alpha protein expression via the A(3) receptor subtype. In particular, we investigated the effect of A(3) receptor antagonists on HIF-1 and vascular endothelial growth factor (VEGF) expression. We found that A(3) antagonists inhibit adenosine-induced HIF-1alpha and VEGF protein accumulation in the hypoxic cells. Investigations in the molecular mechanism showed that A(3) receptor stimulation activates p44/p42 and p38 MAPKs that are required for A(3)-induced increase of HIF-1alpha and VEGF. Further studies are required to demonstrate the in vivo relevance of these observations with regard to the proposed role for adenosine as a key element in hypoxia and in tumors.     

Exendin-4对Ⅰ型糖尿病小鼠内皮祖细胞功能及AKT/eNOS信号通路的影响

目的探讨Exendin-4对Ⅰ型糖尿病小鼠内皮祖细胞(endothelial progenitor cells,EPCs)增殖、迁移、黏附、衰老的影响及对AKT/eNOS信号通路的影响。方法采用密度梯度离心法分离并培养6月龄Ⅰ型糖尿病小鼠EPCs,并用不同浓度的Exendin-4(1、5、10、25μmol·L^-1)处理EPCs,观察EPCs体外克隆形成及增殖能力。同时观察其对糖尿病小鼠EPCs迁移、黏附及衰老的影响。Western blot检测Exendin-4处理对EPCs蛋白激酶B/内皮型一氧化氮合酶(AKT/eNOS)信号通路的影响。结果Exendin-4处理可增加Ⅰ型糖尿病小鼠EPCs克隆形成及增殖能力,尤以10μmol·L^-1时作用效果最佳。Exendin-4处理可增加Ⅰ型糖尿病小鼠EPCs的体外迁移、黏附功能,并抑制细胞衰老。Western blot结果显示,Exendin-4可增强AKT及eNOS磷酸化水平,而GLP-1R抑制剂Exendin-9-39和AKT抑制剂MK-2206则可以阻断这种效应。结论Exendin-4可改善Ⅰ型糖尿病小鼠EPCs增殖、迁移、黏附能力并抑制细胞衰老,其机制可能与调控AKT/eNOS信号通路有关。     

永久性大脑局灶缺血后angiopoietin—2和血管内皮生长因子在小鼠大脑皮层的表达

目的:研究永久性大脑局灶缺血后血管内皮生长因子(VEGF)、angiopoietin-1(Aug-1)、Aug-2、Tie-1和Tie-2在C57BL/6小鼠大脑皮层的表达.方法:采用半定量逆转录聚合酶链反应(RT-PCR)研究VEGF、Aug-1、Aug-2、Tie-1和Tie-2 mRNA表达的变化.采用免疫组织化学法研究VEGF和Aug-2蛋白的表达.结果:在正常小鼠大脑皮层VEGF、Aug-1、Aug-2、Tie-1和Tie-2 mRNA表达水平很低.当大脑中动脉阻断(MCAO)后,在梗塞皮层VEGF、Ang-2和Tie-2 mRNA表达显著增加,并且可维持到第7天.但Ang-1和Tie-1 mRNA表达在梗塞皮层无明显变化.在正常小鼠大脑皮层,几乎观察下到VEGF和Ang-2蛋白的表达.MCAO后8小时Ang-2蛋白发达在皮层梗塞区明显增加,1天后可在梗塞灶周边区看到Ang-2蛋白增加;而VEGF蛋白则在MCAO后2小时在皮层梗塞区即显著升高,1天后在梗塞灶周边区可观察到VEGF蛋白增加.不论在皮层梗塞区还是在梗塞灶周边区,Ang-2和VEGF免疫阳性都限于内皮细胞和胶质样细胞.结论:大脑局灶缺血后Ang-2和VEGF表达增加,可能有利于缺血大脑皮层的血管新生.     

Urocortin induced expression of COX-2 and ICAM-1 via corticotrophin-releasing factor type 2 receptor in rat aortic endothelial cells

Background and purpose:

Our previous study showed that urocortin (Ucn1) exacerbates the hypercoagulable state and vasculitis in a rat model of sodium laurate-induced thromboangiitis obliterans. Furthermore, the inflammatory molecules COX-2 and ICAM-1 may participate in this effect. In the present study, the effects of Ucn1 on COX-2 and ICAM-1 expression in lipopolysaccharide (LPS)-induced rat aortic endothelial cells (RAECs) were investigated and the mechanisms involved explored.

Experimental approach:

RAECs were isolated from adult male Wistar rats, and identified at the first passage. Experiments were performed on cells, from primary culture, at passages 5–8. The expression of COX-2 and ICAM-1 at both mRNA and protein levels was determined by semi-quantitative RT-PCR and Western blot analysis. Levels of PGE₂ and soluble ICAM-1 (sICAM-1) in culture medium were measured by enzyme-linked immunosorbent assay. Furthermore, the phosphorylation status of p38MAPK, ERK1/2, JNK, Akt and NF-κB was analysed by Western blot; nuclear translocation of NF-κB was observed by immunofluorescence.

Key results:

Ucn1 augmented LPS-induced expression of COX-2 and ICAM-1 in RAECs in a time- and concentration-dependent manner. Ucn1 increased PGE₂ and sICAM-1 levels. These effects were abolished by the CRF₂ receptor antagonist, antisauvagine-30, but not by the CRF₁ receptor antagonist, NBI-27914. Moreover, Ucn2 activated p38MAPK and augmented NF-κB nuclear translocation and phosphorylation, whereas ERK1/2, JNK and Akt pathways were not involved in this process.

Conclusions and implications:

These findings suggest that Ucn1 exerts pro-inflammatory effects by augmenting LPS-induced expression of COX-2 and ICAM-1 in RAECs via CRF₂ receptors and the activation of p38MAPK and NF-κB.     

Prostaglandin E2 regulates cellular migration via induction of vascular endothelial growth factor receptor-1 in HCA-7 human colon cancer cells

An important event in the development of tumors is angiogenesis, or the formation of new blood vessels. Angiogenesis is also known to be involved in tumor cell metastasis and is dependent upon the activity of the vascular endothelial growth factor (VEGF) signaling pathway. Studies of mice in which the EP3 prostanoid receptors have been genetically deleted have shown a role for these receptors in cancer growth and angiogenesis. In the present study, human colon cancer HCA-7 cells were used as a model system to understand the potential role of EP3 receptors in tumor cell migration. We now show that stimulation of HCA-7 cells with PGE₂ enhanced the up-regulation of VEGF receptor-1 (VEGFR-1) expression by a mechanism involving EP3 receptor-mediated activation of phosphatidylinositol 3-kinase and the extracellular signal-regulated kinases. Moreover, the PGE₂ stimulated increase in VEGFR-1 expression was accompanied by an increase in the cellular migration of HCA-7 cells. Given the known involvement of VEGFR-1 in cellular migration, our results suggest that EP3 receptors may contribute to tumor cell metastasis by increasing cellular migration through the up-regulation of VEGFR-1 signaling.     

Inflammatory cytokines in vascular dysfunction and vascular disease

The vascular inflammatory response involves complex interaction between inflammatory cells (neutrophils, lymphocytes, monocytes, macrophages), endothelial cells (ECs), vascular smooth muscle cells (VSMCs), and extracellular matrix (ECM). Vascular injury is associated with increased expression of adhesion molecules by ECs and recruitment of inflammatory cells, growth factors, and cytokines, with consequent effects on ECs, VSMCs and ECM. Cytokines include tumor necrosis factors, interleukins, lymphokines, monokines, interferons, colony stimulating factors, and transforming growth factors. Cytokines are produced by macrophages, T-cells and monocytes, as well as platelets, ECs and VSMCs. Circulating cytokines interact with specific receptors on various cell types and activate JAK-STAT, NF-κB, and Smad signaling pathways leading to an inflammatory response involving cell adhesion, permeability and apoptosis. Cytokines also interact with mitochondria to increase the production of reactive oxygen species. Cytokine-induced activation of these pathways in ECs modifies the production/activity of vasodilatory mediators such as nitric oxide, prostacyclin, endothelium-derived hyperpolarizing factor, and bradykinin, as well as vasoconstrictive mediators such as endothelin and angiotensin II. Cytokines interact with VSMCs to activate Ca²⁺, protein kinase C, Rho-kinase, and MAPK pathways, which promote cell growth and migration, and VSM reactivity. Cytokines also interact with integrins and matrix metalloproteinases (MMPs) and modify ECM composition. Persistent increases in cytokines are associated with vascular dysfunction and vascular disease such as atherosclerosis, abdominal aortic aneurysm, varicose veins and hypertension. Genetic and pharmacological tools to decrease the production of cytokines or to diminish their effects using cytokine antagonists could provide new approaches in the management of inflammatory vascular disease.     

基于血管内皮生长因子信号通路/肿瘤坏死因子信号通路的桃核承气汤防治脑卒中双向调节分子网络机制

脑卒中长期以来损害着人类的健康,由于其发病机制复杂,目前尚无令人满意的治疗策略。桃核承气汤在临床上对脑卒中疗效显著。本研究通过TCMSP、TCMIP、BATMAN-TCM和TCMID数据库进行成分收集,采用PharmMapper、BATMAN-TCM数据库进行靶点的预测和筛选,使用R语言包clusterProfiler对靶点进行功能富集分析,最后应用GEO数据库和分子对接对关键靶点进行验证。结果显示,桃核承气汤51个活性成分可能通过调控内皮型一氧化氮合酶(NOS3)、环加氧酶2 (PTGS2)和基质金属蛋白酶9 (MMP9)等15个关键靶点,影响血管内皮生长因子信号通路等发挥预防脑卒中的作用,影响肿瘤坏死因子信号通路等发挥治疗脑卒中的作用。GEO数据分析表明,桃核承气汤防治脑卒中的关键靶点:雄激素受体(AR)、胱天蛋白酶8 (CASP8)、细胞间黏附分子1 (ICAM1)、白细胞介素1β(IL1B)、丝裂原活化蛋白激酶14 (MAPK14)、MMP9、髓过氧化物酶(MPO)、过氧化物酶体增生激活受体γ(PPARG)、PTGS2和细胞肿瘤抗原p53 (TP53)为上调基因;血清白蛋白(A...     

二苯乙烯苷对动脉粥样硬化大鼠主动脉胞间粘附分子1、血管细胞粘附分子1及血管内皮生长因子表达的影响

目的探讨二苯乙烯苷(TSG)抗动脉粥样硬化(AS)的可能机制。方法采用高脂饲料喂饲+维生素D37MU·kg-1ip1次制备大鼠AS模型。造模12周后治疗性ig给予TSG30,60和120mg·kg-1·d-1。给药6周后,采用黄嘌呤氧化酶法测定血清超氧化物歧化酶(SOD)活性,硫代巴比妥酸比色法测定血清丙二醛(MDA)含量,Western蛋白印迹法检测主动脉胞间粘附分子1(ICAM-1)、血管细胞粘附分子1(VCAM-1)及血管内皮生长因子(VEGF)的表达,逆转录聚合酶链反应法检测主动脉ICAM-1和VCAM-1 mRNA表达,免疫组织化学法检测主动脉VEGF蛋白的表达。结果与正常组相比,AS模型组大鼠血清SOD活性明显降低,MDA水平明显提高,主动脉ICAM-1,VCAM-1及VEGF mRNA和蛋白表达显著增高。与模型组相比,TSG给药6周能明显提高大鼠血清SOD活性,降低MDA水平,对主动脉ICAM-1,VCAM-1及VEGF mRNA和蛋白表达均有明显抑制作用。结论TSG对大鼠实验性AS具有治疗作用,其机制可能与其抗氧化和调节细胞因子分泌有关。     

Salvianolic acid B protects human endothelial progenitor cells against oxidative stress-mediated dysfunction by modulating Akt/mTOR/4EBP1, p38 MAPK/ATF2, and ERK1/2 signaling pathways

The vascular endothelium is specifically sensitive to oxidative stress, and this is one of the mechanisms that causes widespread endothelial dysfunction in most cardiovascular diseases and disorders. Protection against reactive oxygen species (ROS)-mediated oxidative damage via antioxidant mechanisms is essential for tissue maintenance and shows therapeutic potential for patients suffering from cardiovascular and metabolic disorders. Salvianolic acid B (SalB), a natural bioactive component known from Traditional Chinese Medicine, has been reported to exert cellular protection in various types of cells. However, the underlying mechanisms involved are not fully understood. Here, we showed that SalB significantly promoted the migratory and tube formation abilities of human bone marrow derived-endothelial progenitor cells (BM-EPCs) in vitro, and substantially abrogated hydrogen peroxide (H₂O₂)-induced cell damage. SalB down-regulated Nox4 and eNOS, as well as nicotinamide adenine dinucleotide phosphate (NADPH)-oxidase expression upon H₂O₂ induction that in turn prevents oxidative-induced endothelial dysfunction. Moreover, SalB suppressed the Bax/Bcl-xL ratio and caspase-3 activation after H₂O₂ induction. Furthermore, our results provide mechanistic evidence that activation of the mTOR/p70S6K/4EBP1 pathways is required for both SalB-mediated angiogenic and protective effects against oxidative stress-induced cell injury in BM-EPCs. Suppression of MKK3/6-p38 MAPK-ATF2 and ERK1/2 signaling pathways by SalB significantly protected BM-EPCs against cell injury caused by oxidative stress via reduction of intracellular ROS levels and apoptosis. Taken together, by providing a mechanistic insight into the modulation of redox states in BM-EPCs by SalB, we suggest that SalB has a strong potential of being a new proangiogenic and cytoprotective therapeutic agent with applications in the field of endothelial injury-mediated vascular diseases.     

The adaptor Lnk (SH2B3): an emerging regulator in vascular cells and a link between immune and inflammatory signaling

A better knowledge of the process by which inflammatory extracellular signals are relayed from the plasma membrane to specific intracellular sites is a key step to understand how inflammation develops and how it is regulated. This review focuses on Lnk (SH2B3) a member, with SH2B1 and SH2B2, of the SH2B family of adaptor proteins that influences a variety of signaling pathways mediated by Janus kinase and receptor tyrosine kinases. SH2B adaptor proteins contain conserved dimerization, pleckstrin homology, and SH2 domains. Initially described as a regulator of hematopoiesis and lymphocyte differentiation, Lnk now emerges as a key regulator in hematopoeitic and non hematopoeitic cells such as endothelial cells (EC) moderating growth factor and cytokine receptor-mediated signaling. In EC, Lnk is a negative regulator of TNF signaling that reduce proinflammatory phenotype and prevent EC from apoptosis. Lnk is a modulator in integrin signaling and actin cytoskeleton organization in both platelets and EC with an impact on cell adhesion, migration and thrombosis. In this review, we discuss some recent insights proposing Lnk as a key regulator of bone marrow-endothelial progenitor cell kinetics, including the ability to cell growth, endothelial commitment, mobilization, and recruitment for vascular regeneration. Finally, novel findings also provided evidences that mutations in Lnk gene are strongly linked to myeloproliferative disorders but also autoimmune and inflammatory syndromes where both immune and vascular cells display a role. Overall, these studies emphasize the importance of the Lnk adaptor molecule not only as prognostic marker but also as potential therapeutic target.     

4-Hydroxy tempol-induced impairment of mitochondrial function and augmentation of glucose transport in vascular endothelial and smooth muscle cells

The water-soluble and cell permeable nitroxide derivative 4-hydroxy tempol (TPL) has been shown to reduce or ameliorate oxidative stress-induced dysfunction and damage in vascular endothelial cells. We studied the effects of TPL on glucose transport and metabolism in bovine aortic endothelial (VEC) and smooth muscle cells (VSMC) under normal and high glucose conditions. Normally, these cells operate an autoregulatory protective mechanism that limits the rate of glucose transport under hyperglycemic conditions by decreasing the cell content of their typical glucose transporter GLUT-1 mRNA and protein as well as its plasma membrane abundance. TPL augmented the rate of glucose transport both under normo- and hyperglycemic conditions by increasing GLUT-1 mRNA and protein content and its plasma membrane abundance in both types of cells, leading to an increased flux of glucose into the cells. These effects were found related to ROS-generating and oxidant activities of TPL and to a decreased rate of mitochondrial ATP production under both normo- and hyperglycemic conditions. Since impaired mitochondrial functions, and in particular decreased rate of ATP production, augment the expression of GLUT-1 protein and glucose transport and metabolism, we suggest that the stimulatory effects of TPL in vascular cells results from its unfavorable interactions in the mitochondrion. It is therefore suggested that effects of TPL in cells of cardiovascular system be evaluated in parallel to its adverse effects on glucose and energy metabolism.     

The roles of CYP450 epoxygenases and metabolites, epoxyeicosatrienoic acids, in cardiovascular and malignant diseases

Cytochrome P450 (CYP) epoxygenases metabolize arachidonic acid to biologically active eicosanoids. The primary epoxidation products are four regioisomers of cis-epoxyeicosatrienoic acid (EET): 5,6-, 8,9-, 11,12-, and 14,15-EET. CYP2J2, CYP2C8, and CYP2C9 are the predominant epoxygenase isoforms involved in EET formation. CYP2J and CYP2C gene families in humans are abundantly expressed in the endothelium, myocardium, and kidney. The cardiovascular effects of CYP epoxygenases and EETs range from vasodilation, anti-hypertension, pro-angiogenesis, anti-atherosclerosis, and anti-inflammation to anti-injury caused by ischemia-reperfusion. Using transgenic animals for in vivo analyses of CYP epoxygenases revealed comprehensive and marked cardiovascular protective effects. In contrast, CYP epoxygenases and their metabolites, EETs, are upregulated in human tumors and promote tumor progression and metastasis. These biological effects result from the anti-apoptosis, pro-mitogenesis, and anti-migration roles of CYP epoxygenases and EETs at the cellular level. Importantly, soluble epoxide hydrolase (sEH) inhibitors are anti-hypertensive and anti-inflammatory and, therefore, protect the heart from damage, whereas the terfenadine-related, specific inhibitors of CYP2J2 exhibit strong anti-tumor activity in vitro and in vivo. Thus, CYP2J2 and arachidonic acid-derived metabolites likely play important roles in regulating cardiovascular functions and malignancy under physiological and/or pathological conditions. Moreover, although challenges remain to improving the drug-like properties of sEH inhibitors and identifying efficient ways to deliver sEH inhibitors, sEH will likely become an important therapeutic target for cardiovascular diseases. In addition, CYP2J2 may be a therapeutic target for treating human cancers and leukemia.     

Hypoxia and the integrated stress response promote pulmonary hypertension and preeclampsia: Implications in drug development

Chronic hypoxia is a common cause of pulmonary hypertension, preeclampsia, and intrauterine growth restriction (IUGR). The molecular mechanisms underlying these diseases are not completely understood. Chronic hypoxia may induce the generation of reactive oxygen species (ROS) in mitochondria, promote endoplasmic reticulum (ER) stress, and result in the integrated stress response (ISR) in the pulmonary artery and uteroplacental tissues. Numerous studies have implicated hypoxia-inducible factors (HIFs), oxidative stress, and ER stress/unfolded protein response (UPR) in the development of pulmonary hypertension, preeclampsia and IUGR. This review highlights the roles of HIFs, mitochondria-derived ROS and UPR, as well as their interplay, in the pathogenesis of pulmonary hypertension and preeclampsia, and their implications in drug development.