重组腺相关病毒介导的细胞色素P450表氧化酶基因对TNF-α诱导人脐静脉内皮细胞炎症的影响

目的研究过度表达细胞色素P450表氧化酶基因引起内源性EETs产生增加是否能抑制由TNF—α诱导的内皮炎症。方法以携带三种不同表氧化酶基因的重组腺相关病毒rAAV- CYP2C11、rAAV—CYP2J2和rAAV—CYPF87V转染人脐静脉内皮细胞,然后再以TNF—α干预,来研究它们对内皮VCAM-1的表达及外周血单核细胞PBMC与内皮细胞粘附的影响。结果TNF-α诱导了 HUVEC中VCAM-1蛋白质的表达,rAAV—CYP2C11、rAAV—CYP2J2能明显抑制TNF-α的这一作用。 TNF-α诱导了PBMC与HUVEC的粘附(100±0．0％ vs 620．1±65．3％),rAAV-CYP2C11、rAAV- CYP2J2能明显抑制TNF-α的这一作用(分别为120．3±33．4％ vs 387．7±27．4％．131．0±28．7％ vs 535．0±69．7％)。结论CYP2C11和CYP2J2基因具有显著的保护内皮细胞、对抗炎症介质介导的内皮损伤的作用。     

Effects of the differentiated keratinocyte phenotype on expression levels of CYP1-4 family genes in human skin cells

Epoxyeicosatrienoic acids produced by mouse CYP2B19 have been implicated in mechanisms regulating epidermal cornification (Ladd, P.A., Du, L., Capdevila, J.H., Mernaugh, R., Keeney, D.S., 2003. Epoxyeicosatrienoic acids activate transglutaminases in situ and induce cornification of epidermal keratinocytes. J. Biol. Chem. 278, 35184-35192). In this study, we aimed to identify CYPs that are up-regulated during keratinocyte differentiation and potentially responsible for epoxyeicosatrienoic acid formation in human skin. The cellular differentiation state of human epidermal cell cultures was manipulated to resemble the basal, spinous, and granular cell phenotypes in vivo. Changes in CYP mRNA levels were measured as a function of differentiation state for a panel of 15 CYPs that included known and putative arachidonate monooxygenases. Quantitative real-time PCR analyses showed that all of the CYPs were expressed in differentiating epidermal cell cultures and in human epidermis, with the exception of CYP2B6, which was poorly expressed in vitro. Six CYPs were strongly up-regulated at Day 6 and Day 8 of in vitro differentiation (CYP4B1, 2W1, 2C18, 3A4, 2C19, 2C9); the increase in mRNA levels ranged from 27- to 356-fold. Only CYP2U1 mRNA levels decreased (6-fold change) during cellular differentiation. Six CYPs showed little variation (<2-fold change) in mRNA levels during in vitro differentiation (CYP2S1, 2J2, 1B1, 1A1, 2E1, 2D6). No single CYP was identifiable as being a functional counterpart to CYP2B19 in mouse skin since none qualified as being mainly responsible for epidermal epoxyeicosatrienoic acid formation. Rather, the data suggest that epoxyeicosatrienoic acids in human skin are formed by several CYPs expressed in different cell layers of the epidermis. This would predict that CYP-derived eicosanoids have different functions in different epidermal cell layers.     

Cyclooxygenases, lipoxygenases, and epoxygenases in CNS: their role and involvement in neurological disorders

Three enzyme systems, cyclooxygenases that generate prostaglandins, lipoxygenases that form hydroxy derivatives and leukotrienes, and epoxygenases that give rise to epoxyeicosatrienoic products, metabolize arachidonic acid after its release from neural membrane phospholipids by the action of phospholipase A(2). Lysophospholipids, the other products of phospholipase A(2) reactions, are either reacylated or metabolized to platelet-activating factor. Under normal conditions, these metabolites play important roles in synaptic function, cerebral blood flow regulation, apoptosis, angiogenesis, and gene expression. Increased activities of cyclooxygenases, lipoxygenases, and epoxygenases under pathological situations such as ischemia, epilepsy, Alzheimer's disease, Parkinson disease, amyotrophic lateral sclerosis, and Creutzfeldt-Jakob disease produce neuroinflammation involving vasodilation and vasoconstriction, platelet aggregation, leukocyte chemotaxis and release of cytokines, and oxidative stress. These are closely associated with the neural cell injury which occurs in these neurological conditions. The metabolic products of docosahexaenoic acid, through these enzymes, generate a new class of lipid mediators, namely docosatrienes and resolvins. These metabolites antagonize the effect of metabolites derived from arachidonic acid. Recent studies provide insight into how these arachidonic acid metabolites interact with each other and other bioactive mediators such as platelet-activating factor, endocannabinoids, and docosatrienes under normal and pathological conditions. Here, we review present knowledge of the functions of cyclooxygenases, lipoxygenases, and epoxygenases in brain and their association with neurodegenerative diseases.     

细胞色素P450基因对高脂饮食诱导不同周龄小鼠动脉粥样硬化的保护作用机制

目的在高脂饮食诱导小鼠动脉粥样硬化中研究CYP2C8基因对动脉粥样硬化的作用及相关机制。方法 :以20和40周龄APOEKO+/-CYP2C8Tg+/-和CYP2C8Tg+/-转基因的小鼠为研究对象,相同基因背景和周龄的同窝APOEKO+/-和C57BL/6小鼠设为对照。在第5,20,40周时测各组动物EET含量,用Real-time PCR法检测各组小鼠的主动脉PPAR-γ和MCP-1基因表达水平,Western blot分析各组小鼠的主动脉(p-)eNOS和NF-κB蛋白的表达与小鼠的肝脏PI3K、(p-)AKT、(p-)ERK和(p-)P38等信号通路蛋白的表达情况。结果 :在高脂饮食中,CYP2C8Tg+/-组和APOEKO+/-CYP2C8Tg+/-组的EET浓度明显增高。Western blot显示:高表达CYP2C8在肝脏中明显上调PI3K、(p-)AKT、(p-)ERK和(p-)P38蛋白;在主动脉明显上调(p-)eNOS蛋白,下调NF-κB蛋白。Real-time PCR分析显示高表达CYP2C8在主动脉中下调MCP-1蛋白。结论 :本研究高表达CYP2C8基因具有显著的抗炎作用,这一作用是...     

Human cytochrome P450 epoxygenases: Variability in expression and role in inflammation-related disorders

Beyond their contribution to the metabolism of xenobiotics, cytochrome P450 (CYP) epoxygenases are actively involved in the metabolism of endogenous substances, like arachidonic acid (AA). The main human CYP epoxygenases, i.e. CYP2C8, CYP2C9, CYP2C19 and CYP2J2, convert AA to four regioisomer epoxyeicosatrienoic acids (EETs). EETs possess a wide range of established protective effects on the human cardiovascular system of which anti-inflammatory actions have gained great recent interest. The expression of CYP epoxygenases is regulated through an extremely complex network of nuclear receptors, microRNAs and genetic/epigenetic factors. Accordingly, a large number of biological variables as well as xenobiotics and environmental factors can influence the expression of CYP epoxygenases, resulting in a significant intra- and inter-individual variability in the expression and activity of these enzymes and subsequently in EET biosynthesis. Moreover, human CYP epoxygenases are mainly expressed in the liver; however, these enzymes are also expressed, at various extents, in most extrahepatic tissues, resulting in a marked inter-tissue variability in the expression of CYP epoxygenases. The inter-tissue, inter- and intra-individual variability in the expression of epoxygenases may lead to differences in the relative abundance of EETs among tissues, among individuals of a population and/or different ethnicities and in a given individual under various conditions. The variation in the abundance of EETs may explain, at least in part, the inter-tissue and inter-individual differences observed in the prevalence of inflammation-related disorders including cardiovascular disease, and why in a given individual, various conditions can contribute to the development of diseases with an important inflammatory component.     

转染细胞色素P450表氧化酶基因对TNF-α损伤大鼠内皮依赖性血管舒张反应的保护作用及机制研究

目的研究过度表达表氧化酶基因,增加内源性EETs的产生是否对TNF-α损伤大鼠内皮依赖性血管舒张反应具有保护作用,并初步从对血管VCAM-1表达的影响探讨其机制。方法将携带细胞色素P450表氧化酶基因的真核表达载体pCB6质粒导入大鼠体内,2周后经静脉给予TNF-α,6 h后观察去甲肾上腺素预收缩的主动脉血管环对乙酰胆碱的舒张反应,并以western blot 检测血管中VCAM-1蛋白质的表达情况。结果 TNF-α降低了主动脉环对乙酰胆碱的舒张反应, CYP2C11、CYP2J2和CYPF87V基因转染使得这种被TNF-α降低的血管舒张反应增强。TNF-α增加了血管VCAM-1表达,CYP2C11、CYP2J2和CYPF87V基因转染使得这种被TNF-α诱导的VCAM-1表达减少。结论CYP2C11、CYP2J2和CYPF87V基因能提高了血管对舒血管物质的反应性。本研究提示,通过上调体内表氧化酶基因表达水平提高内源性EETs浓度可减轻炎症介导的血管损伤,这为研究动脉粥样硬化的防治提供了新的思路。     

细胞色素P450基因对高脂饮食诱导不同周龄小鼠动脉粥样硬化的保护作用

目的研究血管内皮高表达CYP2C8基因能否改善小鼠动脉粥样硬化。方法以20和40周龄APOEKO+/-CYP2C8Tg+/-和CYP2C8Tg+/-基因(血管内皮特异性CYP2C8+/-转基因)的小鼠(n=10/组)为研究对象,相同基因背景和周龄的同窝APOEKO+/-和C57BL/6小鼠设为对照。采用PCR技术鉴定小鼠CYP2C8+/-基因;油红O染色检测APOEKO+/-CYP2C8Tg+/-、CYP2C8Tg+/-、APOEKO+/-和C57BL/6小鼠主动脉斑块形成面积;酶比色检测APOEKO+/-CYP2C8Tg+/-、CYP2C8Tg+/-、APOEKO+/-和C57BL/6小鼠血清TG、TCH、HDL。结果 20和40周龄APOEKO+/-CYP2C8Tg+/-和CYP2C8Tg+/-小鼠主动脉斑块形成面积与同周龄野生型小鼠相比明显减少,并且明显改善了血脂代谢状态。结论高表达CYP2C8基因能够改善西方饮食诱导的不同周龄小鼠的动脉粥样硬化。     

A2A受体-EETs途径在盐敏感性高血压治疗中的作用

激活大鼠腺苷2A受体（A2AR）可使表氧化酶活性增强,从而提高环氧二十碳三烯酸（EETs）的水平,因EETs有扩张肾血管、降血压等作用,故A2AR—EETs途径有抗升压作用。通过盐敏感性高血压遗传模型Dahl盐敏感性（Dahl SS）大鼠和Dahl盐抵抗性（DahlSR）大鼠的相关实验得知,高盐喂养的DahlSR大鼠,其腺苷水平及肾脏对腺苷的反应性均提高,使其表氧化酶活性和EETs的水平升高,因而引发更加明显的肾血管舒张反应,即Dahl SR大鼠可通过上调A2AR—EETs途径来调节盐负荷时的血压水平;而DahlSS大鼠却无上述调节能力。因此在盐负荷时上调Dahl SS大鼠的A2AR-EETs途径,有利于治疗盐敏感性高血压。     

Cytochrome P450 epoxygenases, soluble epoxide hydrolase, and the regulation of cardiovascular inflammation

The cytochrome P450 (CYP) epoxygenase enzymes CYP2J and CYP2C catalyze the epoxidation of arachidonic acid to epoxyeicosatrienoic acids (EETs), which are rapidly hydrolyzed to dihydroxyeicosatrienoic acids (DHETs) by soluble epoxide hydrolase (sEH). It is well-established that CYP epoxygenase-derived EETs possess potent vasodilatory effects; however, the cellular effects of EETs and their regulation of various inflammatory processes have become increasingly appreciated in recent years, suggesting that the role of this pathway in the cardiovascular system extends beyond the maintenance of vascular tone. In particular, CYP epoxygenase-derived EETs inhibit endothelial activation and leukocyte adhesion via attenuation of nuclear factor-kappaB activation, inhibit hemostasis, protect against myocardial ischemia-reperfusion injury, and promote endothelial cell survival via modulation of multiple cell signaling pathways. Thus, the CYP epoxygenase pathway is an emerging target for pharmacological manipulation to enhance the cardiovascular protective effects of EETs. This review will focus on the role of the CYP epoxygenase pathway in the regulation of cardiovascular inflammation and (1) describe the functional impact of CYP epoxygenase-derived EET biosynthesis and sEH-mediated EET hydrolysis on key inflammatory process in the cardiovascular system, (2) discuss the potential relevance of this pathway to pathogenesis and treatment of cardiovascular disease, and (3) identify areas for future research.     

细胞色素P450基因降低动脉粥样硬化小鼠MMP-9表达

目的研究血管内皮高表达CYP2C8基因能否降低动脉粥样硬化小鼠的MMP-9的表达。方法以20周龄APOEKO+/-CYP2C8Tg+/-和CYP2C8Tg+/-小鼠(n=10/组)为研究对象,相同基因背景和周龄的同窝APOEKO+/-和C57BL/6小鼠设为对照。采用PCR技术鉴定小鼠CYP2C8+/-基因;油红O染色检测APOEKO+/-CYP2C8Tg+/-、CYP2C8Tg+/-、APOEKO+/-和C57BL/6小鼠主动脉斑块形成面积;用Real-time PCR法检测各组小鼠的主动脉MMP-9基因表达水平,Western blot分析各组小鼠的主动脉MMP-9蛋白的表达情况。用ELISA法检测各组小鼠的血浆IL-1β和IL-10。结果 APOEKO+/-CYP2C8Tg+/-和CYP2C8Tg+/-小鼠主动脉斑块形成面积明显减少,Real-time PCR分析显示高表达CYP2C8在主动脉中明显下调MMP-9基因的表达,Western blot分析结果显示:高表达CYP2C8在主动脉中明显下调MMP-9蛋白的活性。在血清学上,高表达CYP2C8明显上调IL-10而下调IL-1β。结论高表达CYP2C8基因能够降低小鼠的MMP-9的活性、减低炎性介质水平,通过抗炎和稳定粥样斑块而发挥抗粥样硬化作用。