内皮型一氧化氮合酶基因突变与心血管疾病

内皮衍生的一氧化氮（NO）具有重要的生理功能，它由内皮型一氧化氮合酶（eNOS)合成。NO和动脉粥样硬化的形成和血压的调节有关。NO还可能参与冠状动脉痉挛的发生。本文就eNOS基因的突变与心血管疾病的关系进行综述。     

内皮型一氧化氮合酶与心肌缺血再灌注损伤的关系研究进展

内皮型一氧化氮合酶（eNOS）参与心肌缺血再灌注损伤（MIRI）调控机制和信号通路,其不仅在内皮细胞中表达,也在心肌细胞、肥大细胞、肾上皮细胞、红细胞、白细胞和血小板中表达;eNOS既可以合成NO,扩张血管,也可以合成超氧化物,加剧氧化应激。在MIRI中抑制eNOS解偶联和增加其有益磷酸化,可保护血管内皮功能、抑制氧化应激、逆转凋亡和减轻炎症反应等;eNOS可通过磷脂酰肌醇3激酶/丝氨酸/苏氨酸蛋白激酶/eNOS、沉默信息调节剂1/eNOS、腺苷单磷酸活化蛋白激酶/eNOS/一氧化氮等信号通路在MIRI中发挥重要作用。     

秋水仙碱通过激动PI3K/AKT/eNOS信号通路对急性心肌梗死大鼠心功能的影响

目的:探究秋水仙碱通过调节磷脂酰肌醇3-激酶(PI3K)/蛋白激酶B(AKT)/内皮型一氧化氮合酶(eNOS)信号通路对急性心肌梗死(AMI)大鼠心功能的影响。方法:78只大鼠中随机选取12只作为假手术组,剩余大鼠构建AMI模型,造模成功大鼠分为模型组、秋水仙碱组[4 mg/(kg·d)]、秋水仙碱[4 mg/(kg·d)]+LY294002(20 mg/mL)组、秋水仙碱[4 mg/(kg·d)]+MK-2206(60μg/mL)组、秋水仙碱[4 mg/(kg·d)]+L-NAME(1.6 mg/mL)组,每组12只。超声心动图检测大鼠左心室舒张末期内径(LVEDD)、左心室收缩末期内径(LVESD)、射血分数(EF)及短轴缩短率(FS)。处死大鼠,苏木素-伊红(HE)染色检测大鼠心肌组织石蜡切片病理学变化;末端脱氧核苷酸转移酶介导的dUTP缺口末端标记(TUNEL)法检测心肌细胞凋亡率;酶联免疫吸附实验(ELISA)测定大鼠血清肿瘤坏死因子α(TNF-α)、白细胞介素-6(IL-6)、肌酸激酶同工酶(CK-MB)以及心肌组织匀浆中超氧化物歧化酶(SOD)、丙二醛(MDA)、过氧化氢...     

eNOS基因多态性与冠心病

本文在回顾了内皮型一氧化氮合成酶的基因多态性的基础上 ,着重综述了 Glu2 98→ Asp基因突变与冠心病发生的关联性     

前列腺素EI对人脐静脉内皮细胞中NO和eNOS的影响

目的探讨前列腺素EI(prostaglandin EI,PGEI)对内皮细胞一氧化氮(NO)表达和内皮型一氧化氮合酶(eNOS)活性的影响。方法以人脐静脉内皮细胞(HUVEC)为实验对象,检测不同浓度PGEI作用不同时间后,细胞培养上清液和细胞中NO水平的变化,以及细胞eNOS活性的改变。结果(1)随着PGEI浓度的升高,eNOS的活性和NO的含量均逐渐增加(P<0.05);(2)短时间PGEI的干预对eNOS和NO的影响均不明显,24h后细胞中eNOS活性明显升高(P<0.05),NO的含量自12h起随时间延长而增加(P<0.05);(3)用不同PGEI浓度预处理,使TNF-α对eNOS活动的抑制作用减弱。结论PGEI可能通过诱导eNOS的表达,促进NO的释放,且可以重新激活被TNF-α抑制的eNOS活性。     

围产期高盐饮食对雄性子代大鼠肠系膜动脉DDAH2/ADMA/eNOS/NO通路的影响

目的探讨围产期高盐饮食对雄性子代大鼠肠系膜动脉二甲基精氨酸二甲胺水解酶2(DDAH2)/非对称性二甲基精氨酸(ADMA)/内皮型一氧化氮合酶(e NOS)/一氧化氮(NO)通路的影响。方法实验大鼠分为2组:正常饮食(NSD)组和高盐饮食(HSD)组,分别在围产期以普通饲料(含1%Na Cl)和高盐饲料(含8%Na Cl)喂养,分娩后雄性子鼠继续相同饲料喂养至16周。测量子鼠血压,检测肠系膜动脉内皮依赖性舒张功能,检测血浆和肠系膜动脉NO含量、e NOS活性、ADMA含量,检测肠系膜动脉DDAH2活性及DDAH1和DDAH2蛋白质表达水平。结果 16周时,HSD组收缩压显著高于NSD组(P0.01)。HSD组大鼠肠系膜血管张力低于NSD组(P0.01);用ADMA孵育血管环后,NSD组血管张力显著减弱,而HSD组未见显著性变化。与NSD组比较,HSD组血浆NO含量降低(P0.05),e NOS活性降低(P0.01),ADMA含量增加(P0.05);HSD组肠系膜动脉NO含量下降(P0.01),e NOS活性下降(P0.01),ADMA含量升高(P0.05)。HSD组DDAH2活性降低(P0.01),DDAH2蛋白质表达显著降低(P0.01);DDAH1蛋白质表达未见显著改变。HSD组肠系膜动脉指标相关性分析:e NOS活性与NO含量呈正相关,ADMA含量与e NOS活性呈负相关,DDAH2活性、DDAH2蛋白质表达与ADMA含量呈负相关。结论母体围产期高盐饮食导致其雄性子代收缩压增高,肠系膜动脉内皮依赖性舒张功能障碍,此与肠系膜动脉DDAH2表达下降、活性降低和DDAH2/ADMA/e NOS/NO通路障碍有关。     

中国汉族人群eNOS基因G894T多态性与原发性高血压关系的Meta分析

目的系统评价中国汉族人群内皮型一氧化氮合酶（eNOS）基因G894T多态性与原发性高血压的关系。方法制定文献纳入标准和排除标准,全面检索中国期刊全文数据库、中文科技期刊数据库、中国生物医学文献数据库、PubMed、Cochrane图书馆等关于eNOS基因G894T多态性与原发性高血压关系的原始文献,采用RevMan4.2软件对入选文献进行Meta分析。结果共纳入13项研究,累计原发性高血压患者2593例,健康对照2620例。纳入文献具有高异质性,采用随机效应模型进行合并分析,合并效应量（GT＋TT）/GG基因型频率OR值为1.39,95%CI：1.11～1.73（P〈0.05）。经敏感性分析和发表偏倚评估,Meta分析结果较稳定,无明显发表偏倚。结论 eNOS基因G894T多态性与中国汉族人群原发性高血压易感性相关。     

川芎嗪通过激活Akt/eNOS通路预防阿霉素致小鼠心脏毒性

目的研究川芎嗪对阿霉素诱导的小鼠心脏毒性的预防作用及其机制。方法建立阿霉素诱导的心脏毒性小鼠模型,将小鼠随机分为3组:对照组、阿霉素组(阿霉素15 mg/kg)、川芎嗪组[川芎嗪60 mg/(kg·d)+阿霉素15 mg/kg],心脏超声检测川芎嗪干预后阿霉素对小鼠心脏功能的影响,HE染色及Masson三色染色检测小鼠心脏组织学及胶原蛋白的变化,TUNEL染色检测小鼠心肌细胞凋亡情况,Western blot检测p-Akt、Akt、p-eNOS、eNOS及cleaved Caspase-3蛋白的表达。结果与阿霉素组相比,川芎嗪组左心室短轴缩短率(FS)和左心室射血分数(EF)显著升高(P0.01);川芎嗪显著降低小鼠心肌细胞凋亡(P0.01),明显抑制小鼠心肌纤维化和炎症细胞浸润(P0.01);与阿霉素组相比,川芎嗪组显著上调p-Akt和p-eNOS的表达(P0.05),显著下调cleaved Caspase-3的表达(P0.01)。结论川芎嗪通过激活Akt/eNOS通路抑制心肌细胞凋亡保护阿霉素诱导损伤心肌可能是川芎嗪预防阿霉素致心脏毒性的一个潜在机制。     

酪氨酸蛋白激酶在β受体激动增加eNOS活性信号通路中的作用

体外培养人脐静脉内皮细胞;采用同位素两步色谱法检测eNOS活性,观察P11(特异性阻断剂Ty_phostin23(T23,1×10-4mol/L)及其无活性衍生物Typhostinl(T1,1×10-4 mol/L)与人脐静脉内皮细胞孵育10min,再与异丙肾上腺素(ISO,1×10-6mol/L)孵育30 min后eNOS活性变化.结果ISO与人脐静脉内皮细胞孵育30 min后eNOS活性明显增加(30.7±3.9)%,P＜0.001;Typhostin23阻断PTK后,ISO诱导的eNOS活性增加受到明显抑制,P＜0.001,而Typhostinl不影响ISO激活eNOS的程度(28.9±3.75)%,P0.05.证实酪氨酸蛋白激酶参与了ISO激活eNOS活性的过程.     

PI3K/AKt/eNOS信号通路在硫化氢抑制ET-1诱导的心肌肥大中的作用

目的观察磷脂酰肌醇-3激酶(PI3K)-蛋白质丝氨酸/苏氨酸激酶(AKt)-内皮型一氧化氮合酶(e NOS)信号转导通路在硫化氢(H2S)抑制内皮素-1(endothelin-1,ET-1)诱导心肌肥大过程中的作用。方法体外培养原代心肌细胞,将其随机分为6组,每组4孔,1对照组:加入等体积无血清的DMEM培养基;2肥大(ET-1)组:加入终浓度为10-8 mol/L的ET-1;剩余4组为实验组,各组分别加入不同终浓度的H2S供体-Na HS:310-15 M Na HS组:加入10-15 mol/L Na HS+10-8 mol/l ET-1;410-14 M Na HS组:加入10-14 mol/L Na HS+10-8 mol/L ET-1;510-13 M Na HS组:加入10-13 mol/L Na HS+10-8 mol/L ET-1;610-12 M Na HS组:加入10-12 mol/L Na HS+10-8 mol/L ET-1。上述各组药物分别刺激24 h后测定心肌细胞表面积、细胞总蛋白含量、培养液NO含量,RT-PCR检测心肌细胞心房利钠肽(atrial natriuretic peptide,ANP)、脑钠肽(B-type natriuretic peptide,BNP)、磷脂酰肌醇-3激酶(phosphatidylinositol-3-kinase,PI3K)、蛋白激酶B(protein kinase B,PKB/AKt)、e NOS m RNA水平,Western Blot技术检测总AKt和磷酸化AKt蛋白表达含量。结果肥大(ET-1)组的心肌细胞表面积(1933.80±143.06)和细胞总蛋白含量(367.51±25.9)均高于对照组(787.27±107.66,218.55±21.28,P0.05),ANP及BNP m RNA的表达量也明显增加(P0.05),但PI3K、AKt、e NOS m RNA表达水平,磷酸化AKt程度和NO的释放量(4.60±0.73)低于对照组(8.63±0.30,P0.05),各实验组给予不同浓度Na HS刺激后能够浓度依赖性的抑制这种肥大效应(P0.05),同时上调了PI3K/AKt/e NOS通路各信号分子的表达量(P0.05)。结论 H2S对ET-1诱导的心肌肥大有一定的抑制作用,这种作用可能与激活PI3K-AKt-e NOS信号通路有关。     

Asymmetric dimethylarginine, derangements of the endothelial nitric oxide synthase pathway, and cardiovascular diseases

Analogues of L-arginine that are chemically modified at the terminal guanidino nitrogen group, such as Nomega-monomethy-L-arginine (L-NMMA), have been used for nitric oxide synthase inhibition. However, L-NMMA and other methylated L-arginine analogues are also endogenously formed. Among these, asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA) have been shown to be the most abundant. Like L-NMMA, ADMA is an inhibitor of NO synthase, whereas SDMA is inactive. ADMA is synthesized by N-methyltransferases, a family of enzymes that methylate L-arginine residues within specific proteins. Free ADMA is released during proteolytic cleavage of methylated proteins; it can be detected in plasma and urine, but its intracellular concentrations appear to be much higher. ADMA is metabolized by the enzyme dimethylarginine dimethylaminohydrolase (DDAH), and inhibition of DDAH activity has been shown to lead to increased ADMA levels and endothelial dysfunction. Plasma levels of ADMA are elevated in endstage renal failure, in atherosclerosis and hypercholesterolemia, in hypertension, and in heart failure. Although the molecular cause for elevation of ADMA concentration in these diseases has not been fully elucidated, evidence is accumulating that ADMA is one cause of endothelial dysfunction in these diseases. Moreover, it may be a marker or even a risk factor for cardiovascular disease. Therefore, pharmacological modulation of ADMA concentration may be a novel therapeutic target in cardiovascular diseases.     

醛固酮对血管外膜诱导型一氧化氮合酶/一氧化氮通路影响的实验研究

目的观察醛固酮对血管外膜诱导型一氧化氮合酶（iNOS）／一氧化氮（NO）通路的影响及作用机制。方法取sD大鼠胸主动脉外膜,分别给予不同浓度醛固酮（ALD）10^-8～10^-6mol／L、ALl）＋螺内酯以及ALD＋RU486进行孵育,此外在给予脂多糖激活血管外膜iNOS／NO的情况下,观察以上各组药物刺激后iNOS／NO系统的变化。与上述药物共同孵育6h后通过Griess法测定相对稳定的代谢产物硝酸盐和亚硝酸盐（NOx）代表NO的产生量,采用[^3H]-L-精氨酸标记的同位素法测定外膜iNOS活性。结果（1）NOx产生的变化：ALD刺激后血管外膜NOx生成无明显变化。用螺内酯拮抗盐皮质激素受体后,高浓度ALD组（10～～10^-6mol／L）血管外膜NOx产生呈下降趋势（P〈0．05）。用RU486拮抗糖皮质激素受体后随ALD浓度增加NOx生成量也呈浓度依赖性增加（P〈0．01）。脂多糖刺激后上述趋势更为明显。（2）iNOS活性的变化：ALD刺激后iNOS活性无明显变化,螺内酯刺激后血管外膜iNOS活性有下降趋势,但无统计学意义。而RU486刺激后血管外膜iNOS活性显著增加（P〈0．05）。同时给予脂多糖刺激后,螺内酯＋ALD组血管外膜iNOS活性显著下降（P〈0．01）,ALD＋RU486组血管外膜iNOS活性显著增加（p〈0．05）。结论ALD主要通过盐皮质激素受体和糖皮质激素受体通路两种途径直接影响血管外膜iNOS／NO系统,醛固酮作用于盐皮质激素受体能够诱导iNOS激活、刺激NO产生,作用于糖皮质激素受体抑制iNOS／NO激活。     

Effect of homocysteine on the l-arginine/nitric oxide synthase/nitric oxide pathway in human platelets

Recent evidence indicates that chronic hyperhomocysteinemia is an independent risk factor for the development of atherosclerosis, thrombosis, and other cardiovascular diseases. This may be secondary to impaired fibrinolysis, or increased platelet reactivity. l-Arginine/nitric oxide synthase/nitric oxide (NO) plays an important role in the regulation of platelet function. The present study was undertaken to determine the effect of homocysteine (HCY) on the l-arginine/NO pathway of human platelets. Washed human platelets were incubated in the presence or absence of HCY for 2 h at 37°C followed by a measurement of indices of the l-arginine/NO pathway. HCY caused a concentration-dependent reduction in the platelet up-take of l-[³H]arginine. HCY also caused a concentration-dependent decrease in nitrite production concurrent with a decrease in cyclic guanosine monophosphate, whereas NO synthase activity of the platelets, measured as conversion of l-[³H]arginine to l-[³H]citrulline, remained unchanged on incubation with HCY. These observations indicate that the l-arginine/NO pathway is involved in the mechanism responsible for the effects of HCY on platelets by diminishing NO production through decreased uptake of l-arginine. Received: June 14, 2001 / Accepted: September 28, 2001     

Mechanisms of reduced nitric oxide/cGMP-mediated vasorelaxation in transgenic mice overexpressing endothelial nitric oxide synthase

NO, constitutively produced by endothelial NO synthase (eNOS), plays a key regulatory role in vascular wall homeostasis. We generated transgenic (Tg) mice overexpressing eNOS in the endothelium and reported the presence of reduced NO-elicited relaxation. The purpose of this study was to clarify mechanisms of the reduced response to NO-mediated vasodilators in eNOS-Tg mice. Thoracic aortas of Tg and control mice were surgically isolated for vasomotor studies. Relaxations to acetylcholine and sodium nitroprusside were significantly reduced in Tg vessels compared with control vessels. Relaxations to atrial natriuretic peptide and 8-bromo-cGMP were also significantly reduced in Tg vessels. Reduced relaxations to these agents were restored by chronic N(G)-nitro-L-arginine methyl ester treatment. Basal cGMP levels of aortas were higher in Tg mice than in control mice, whereas soluble guanylate cyclase (sGC) activity in Tg vessels was approximately 50% of the activity in control vessels. Moreover, cGMP-dependent protein kinase (PKG) protein levels and PKG enzyme activity were decreased in Tg vessels. These observations indicate that chronic overexpression of eNOS in the endothelium resulted in resistance to the NO/cGMP-mediated vasodilators and that at least 2 distinct mechanisms might be involved: one is reduced sGC activity, and the other is a decrease in PKG protein levels. We reported for the first time that increased NO release from the endothelium reduces sGC and PKG activity in mice. These data may provide a new insight into the mechanisms of nitrate tolerance and cross tolerance to nitrovasodilators.     

肠道菌群-TMA-TMAO代谢途径与心血管疾病的研究进展

肠道菌群紊乱与心血管疾病的发生发展密切相关。肠道微生物利用富含胆碱或三甲胺(TMA)结构的物质代谢生成氧化三甲胺(TMAO),而TMAO在心血管疾病如冠心病、动脉粥样硬化、高血压等的发生和发展中起着重要作用。该文就TMAO与心血管疾病关系和肠道菌群-TMA-TMAO代谢途径干预方法的研究进展进行综述。