小凹蛋白-1与内皮型一氧化氮合成酶活性变化在大鼠门静脉高压形成中的作用

目的 探讨肝硬化发生发展过程中小凹蛋白-1的动态变化及与其肝纤维化程度、门静脉压力的关系,探讨小凹蛋白-1对内皮型一氧化氮合成酶(eNOS)作用的可能调控机制.方法 构建二甲基亚硝胺致肝硬化大鼠模型,分别在造模后的1、2、3、4、6周,病理组织学观察肝纤维化程度及测定门静脉压力(PVP),放射强度测定法检测肝硬化组织中eNOS活性,免疫沉淀与Western blot检测小凹蛋白-1和eNOS蛋白变化及其相互作用.结果 造模过程中肝纤维化程度逐渐加重,至第4周已形成典型的肝硬化,其后逐渐减轻;免疫沉淀与Western blot实验结果表明eNOS和小凹蛋白-1可免疫共沉淀,且小凹蛋白-1与eNOS的结合可随造模时间延长而增加;小凹蛋白-1表达与肝纤维化程度、PVP呈显著正相关(r=0.967,P＜0.01;r=0.922,P＜0.01);NOS与肝纤维化程度、PVP呈显著负相关(r=-0.973,P＜0.01;r=-0.947,P＜0.01).结论 小凹蛋白-1作为eNOS的一个负调控因子,参与肝硬化门静脉高压的形成.     

内皮型一氧化氮合成酶

在哺乳动物中已发现 3种一氧化氮合酶 (NOS) (EC 1 14 13 39) ,根据它们的cDNA被首次分离和纯化的顺序将其分别称为NOS1、NOS2和NOS3。NOS1(NOSI ,ncNOS)亦称神经元型 ,主要存在于中枢神经细胞和外周神经元中 ,与神经递质运输有关 ,其活性受Ca2 +和钙调蛋白调节[1] ;NOS2 (NOSⅡ ,iNOS) ,诱导型 ,主要存在于肺泡巨噬细胞和呼吸道上皮细胞中 ,参与某些自身免疫性疾病和感染性休克的发生 ,其活性与Ca2 +和钙调蛋白无关[2 ] ;NOS3(NOSⅢ ,ecNOS)内皮型 ,主要存在于血管内皮细胞 ,在人的肺、肾、脾等组织中也有分布 ,参与调…     

诱导型和内皮型一氧化氮合酶基因多态性与肝硬化门静脉高压的相关性

目的探讨诱导型一氧化氮合酶(iNOS)和内皮型一氧化氮合酶(eNOS)基因多态性与肝硬化门静脉高压的相关性。方法采用病例对照和聚合酶链反应-限制性片段长度多态性技术,检测106 例乙型肝炎后肝硬化患者(其中门静脉高压症65例)和108名健康对照者iNOS基因启动子-969G→C多态性及eNOS基因第七外显子894G→多态性,比较等位基因及基因型频率,并进行综合分析。结果在iNOS启动子969G→C多态性中,门静脉高压症组C等位基因和GC基因型频率比对照组显著升高(x2- 5.93,P<0.05)。GC基因型启动子的活性比GG基因型活性强。在eNOS的894G→T多态性中,T等位基因频率明显高于对照组(x2-3.91,P<0.05)。采用Logistic多元回归显示iNOS基因启动子-969G→C多态性及cNOS的894G→T多态性是门静脉高压症新的危险因素。结论iNOS启动子969G→C多态性和eNOS的894G→T多态性与门静脉高压症相关,是形成门静脉高压症新的危险因素。iNOS启动子-969G→C多态性可导致该基因启动子功能活性增强。     

内皮型一氧化氮合成酶基因多态性与原发性高血压的相关性

高血压是最常见的慢性病,也是心脑血管病最主要的危险因素,目前其发病率呈上升趋势[1,2].原发性高血压（essential hypertension,EH）是受遗传因素与环境因素共同影响的慢性疾病.近年来研究表明,遗传因素在原发性高血压的发生、发展中起着更重要的作用.内皮型一氧化氮合酶（endothelium nitrogen monoxide synthase,eNOS）是高血压的易感因素,它的基因编码所产生的一氧化氮（nitrc oxide,NO）具有调节血管张力、血管重塑、维持血管内皮的完整性等作用.随着血管生物学与临床医学领域联合研究的不断深入,在心血管疾病中研究调查调控高血压基因已成为热点.国内外研究表明,eNOS基因在原发性高血压中发挥重要作用.本文对eNOS基因G894T、T786C和27bpVNTR的多态性影响EH的机制及与EH相关性最新研究进展作一综述.     

门脉高压症患者脾动静脉壁诱导型一氧化氮合成酶的表达

门脉高压症患者脾动静脉壁诱导型一氧化氮合成酶的表达李中明，陈茂平，胡仁崇，刘金斗，李先林，杨镇我们采用免疫组化方法，研究门脉高压患者脾动、静脉壁诱导型一氧化氮合成酶（ｉＮＯＳ）的表达，旨在探讨ＮＯ与门脉高压症内脏血管病理性损伤的关系。一、材料和方法１...     

葡萄糖对血管内皮细胞小凹蛋白1和血管内皮生长因子表达的影响

为了探讨高浓度葡萄糖损伤血管内皮细胞及其对小凹蛋白-1和血管内皮生长因子表达的影响。将人脐静脉内皮细胞株ECV304．分别培养在对照组和含5.5mmol／L、11.1mmol／L、22.0mmol／L、33.0mmol／L葡萄糖的培养基中。经葡萄糖培养24h后，噻唑蓝法测定细胞增殖活性，硝酸还原酶法测定培养上清液中一氧化氮浓度，免疫组织化学和免疫印迹方法检测细胞中小凹蛋白-1和血管内皮生长因子的表达。结果发现，随着葡萄糖浓度的增加，内皮细胞增殖活性呈浓度依赖性抑制(r=-0.776，P=0.000)；一氧化氮浓度呈浓度依赖性增加(r=0.698，P=0.000)；小凹蛋白-1和血管内皮生长因子为棕黄色颗粒，主要分布于胞浆中；血管内皮生长因子的表达呈浓度依赖性增加(r=0.645，P=0.009)；小凹蛋白-1的表达也呈浓度依赖性增加(r=0.808，P=0.000)。提示高糖可诱导血管内皮细胞的血管内皮生长因子和小凹蛋白-1的表达，此变化可能与糖尿病患者高糖致血管病变有关。     

小凹蛋白与心血管疾病

小凹蛋白是构成小凹的标志性蛋白,它们以烧瓶状的内陷形式广泛连接在各细胞质膜上。在多种疾病中均发现存在小凹蛋白的异常,它的突变和缺失与很多疾病的发生发展过程有关,其中包括了冠心病、心肌疾病、高血压病、糖尿病大血管病变等心血管疾病。本文简要概述小凹蛋白与心血管疾病的关系。     

细胞质膜小凹/小凹蛋白1在实验性动脉粥样硬化小鼠血管壁中的表达变化

目的 研究细胞质膜小凹，小凹蛋白1在动脉粥样硬化病变中的表达变化，探索动脉粥样硬化发生过程中细胞胆固醇逆转运障碍的机制。方法采用高脂饲料喂养动脉粥样硬化敏感C57BL／6J小鼠24周，计算机图像分析系统计算动脉粥样硬化病灶面积和主动脉内膜和中膜厚度；电镜观察小凹在主动脉病变区的血管平滑肌细胞表达，Western印迹检测血管壁小凹蛋白1变化情况。结果动脉粥样硬化模型小鼠主动脉病变区的血管平滑肌细胞膜上存在有小凹结构，但排列稀疏，与正常血管平滑肌细胞相比明显减少，泡沫样改变的血管平滑肌细胞未见明显小凹结构的存在。通过Western印迹检测观察到，高脂组血管壁的小凹蛋白1蛋白表达量明显减少，与对照组比较具有显著差异。结论维持细胞内胆固醇平衡的重要结构小凹，小凹蛋白1在动脉粥样硬化病变中明显受损，可能是血管平滑肌细胞胆固醇逆转运障碍重要原因之一。     

外源性血管内皮生长因子对肝硬化大鼠肝组织血管的影响

目的:研究外源性血管内皮生长因子对肝硬化大鼠肝脏组织内血管的影响,以检测肝硬化大鼠肝脏微循环变化.方法:25只肝硬化门静脉高压造模成功SD♂大鼠,体质量180-220 g,随机分为肝硬化门静脉高压对照组(B组,n=10)和肝硬化门静脉高压实验组(C组,n=15),C组应用Alzet微渗泵从大鼠门静脉连续泵入血管内皮生长...     

内皮型一氧化氮合酶基因G894T突变与肝硬化门脉高压的相关性研究

目的　探讨内皮型一氧化氮合酶 (endothelialnitricoxidesynthase ,eNOS)基因第 7外显子G894T点突变与肝硬化门脉高压症之间的关系。方法　采用病例对照和聚合酶链反应 限制性片段长度多态性 (PCR RFLP)方法 ,检测10 6例乙型肝炎后肝硬化患者和 10 8名健康对照者eNOS基因第 7外显子G894T点突变频率和外周血NO 2 /NO 3 含量 ,比较各组间基因型频率与等位基因频率。结果　①中国汉族正常人eNOS基因G894T突变GG、GT和TT基因型频率分别为 86.1%、11.1%和 2 .8%;G、T等位基因频率分别为 91.7%和 8.3 %。②乙型肝炎后肝硬化组GT TT基因型频率高于对照组 ( 2 4.5 %比 3 .9%) ,差异有显著性。③门脉高压症组T等位基因频率明显高于对照组 ,差异有显著性( 17.7%比 8.3 ,P <0 .0 5 ) ,相关分析呈正相关 (r =0 .2 )。携带T等位基因者发生门脉高压症的危险性高于非T等位基因携带者 1.76倍 (OR =2 .76)。结论　eNOS基因第 7外显子G894T突变与肝硬化门脉高压症形成相关 ,T等位基因可能是中国人群门脉高压症的遗传易感基因型     

Liposome-mediated gene transfer of endothelial nitric oxide synthase to cirrhotic rat liver decreases intrahepatic vascular resistance

Background and Aims:  Nitric oxide (NO) production by endothelial nitric oxide synthase (eNOS) in sinusoidal endothelial cells is reduced in the injured liver and leads to intrahepatic portal hypertension. The present study evaluates the effects of liposome-mediated gene transfer of eNOS on the intrahepatic vascular resistance and portal venous pressure (PVP) in cirrhotic rats.
Methods:  Hepatic cirrhosis was induced in male Sprague–Dawley rats by intraperitoneal injection of carbon tetrachloride (CCl₄), whereas the control normal rats were given the same dose of peanut oil. Plasmid eukaryotic expression vector (liposome-pcDNA3/eNOS) was injected into the portal vein of CCl₄ cirrhotic rats, whereas cirrhotic controls received the same dose of naked plasmid (liposome-pcDNA3) or Tris buffer, and control normal rats received the same dose of Tris buffer. Five days after gene transfer, the levels of eNOS mRNA and protein, NO production, PVP and the changes of hepatic intrahepatic vascular resistance were investigated.
Results:  Five days after eNOS gene transfer, the levels of eNOS mRNA, eNOS protein and NO production in cirrhotic rats increased remarkably, while hepatic vascular resistance and PVP decreased significantly in cirrhotic rats.
Conclusion:  Liposome-mediated eNOS gene transfer via intraportal injection is feasible and the increase of intrahepatic eNOS leads to a marked decrease in introhepatic vascular resistance and PVP. These data indicate that intrahepatic eNOS plays an important role in the pathogenesis of portal hypertension and gene transfer of eNOS is a potential and novel therapy for portal hypertension.     

内皮细胞型NO合酶基因第7外显子894G→T点突变与糖尿病肾病相关性研究

目的 探讨内皮细胞型NO合酶（eNOS)基因第7外显子894G→T点突变与中国北方汉族人2型糖尿病（T2DM）合并肾病（DN）之间的关系。方法 运用聚合酶链式反应限制性片段长度多态性技术（PCR－RFLP），结合DNA测序技术，检测了228例中国北方汉族人的eNOS基因第7外显子894G→T错义突变位点的基因型，其中T2DM患者143例（DN79例），健康成人85例，并对各组间的等位基因频率与基因型频率进行了比较。结果 ①T2DM组的T等位基因及TG基因型频率与正常对照（N）组无显著性差异（P＞0．05）。②DN＋组T等位基因及TG基因型频率显著高于糖尿病非肾病患者（P＜0．05）。③SBP、HbA1c、TC、TG和eNOS基因第7外显子894G→T点突变均与糖尿病肾病有关（P＜0．05）。结论 eNOS基因第7外显子894G→T点突变的T等位基因可能是中国人2型糖尿病易患肾病的独立危险因素。     

人胃癌组织中一氧化氮合酶的表达

目的探讨NOS与胃癌的关系.方法用NADPH-d组织化学法测定了正常胃组织、癌旁组织和癌组织中一氧化氮合酶(NOS)表达水平.结果正常胃组织中粘膜上皮细胞、各种有分泌功能的细胞及肌层神经纤维中均有NOS表达,测一个视野NOS阳性细胞的平均灰度,正常胃组织为112、癌旁组织为120、胃癌组织为145.各组间差异有显著意义.表明正常胃组织NOS活性最高,胃癌组织NOS活性最低.结论①正常胃组织有广泛的NOS分布,提示NO对维持正常胃功能具有重要作用;②胃粘膜细胞癌变过程中,NOS活性明显降低,提示NOS活性与胃粘膜细胞癌变有高度相关性.     

C-reactive protein decreases endothelial nitric oxide synthase activity via uncoupling

C-reactive protein (CRP), a cardiovascular risk marker, induces endothelial dysfunction. We have previously shown that CRP decreases endothelial nitric oxide synthase (eNOS) expression and bioactivity in human aortic endothelial cells (HAECs). In this study, we examined the mechanisms by which CRP decreases eNOS activity in HAECs. To this end, we explored different strategies such as availability of tetrahydrobiopterin (BH4)-a critical cofactor for eNOS, superoxide (O(2)(-)) production resulting in uncoupling of eNOS and phosphorylation/dephosphorylation of eNOS. CRP treatment significantly decreased levels of BH4 thereby promoting eNOS uncoupling. Pretreatment with sepiapterin, a BH4 precursor, prevented CRP-mediated effects on BH(4) levels, superoxide production as well as eNOS activity. The gene expression and enzymatic activity of GTPCH1, the first enzyme in the de novo biosynthesis of BH(4), were significantly inhibited by CRP. Importantly, GTPCH1 is known to be regulated by cAMP-mediated pathway. In the present study, CRP-mediated inhibition of GTPCH1 activity was reversed by pretreatment with cAMP analogues. Furthermore, CRP-induced O(2)(-) production was reversed by pharmacologic inhibition and siRNAs to p47 phox and p22 phox. Additionally, CRP treatment significantly decreased the eNOS dimer: monomer ratio confirming CRP-mediated eNOS uncoupling. The pretreatment of cells with NO synthase inhibitor (N-nitro-l-arginine methyl ester [l-NAME]) also prevented CRP-mediated O(2)(-) production further strengthening CRP-mediated eNOS uncoupling. Additionally, CRP decreased eNOS phosphorylation at Ser1177 as well as increased phosphorylation at Thr495. CRP appears to mediate these effects through the Fcgamma receptors, CD32 and CD64. To conclude, CRP uncouples eNOS resulting in increased superoxide production, decreased NO production and altered eNOS phosphorylation.     

Expression of inducible nitric oxide synthase in human gastric cancer

INTRODUCTIONInduciblenitricoxidesynthase(iNOS)isanenzymethatcatalyzestheformationofnitric0xide(N0)fromL-arginine.iNOSexpressionandactivityresultsintheproduction0fhighlevelsofNO[1].ThegenerationofphysiologicallevelsofNOisimp0rtantformucosalfunctionanditalsoexertsacytoprotectiveeffectonthegastr0intestinalmucosa.However,increasediNOSexpressionhasbeenobservedinpatientswithchronicinflammatorydiseasesofthegastr0intestinaltract,suchasulcerativec0litis[2'3],andgastritis['Jandithasbeenspecul…     

Subcellular distribution of nitric oxide synthase isoforms in the rat duodenum

AIM:To study the cell-type specific subcellular distribution of the three isoforms of nitric oxide synthase(NOS) in the rat duodenum.METHODS:Postembedding immunoelectronmicroscopy was performed,in which primary antibodies for neuronal NOS(nNOS),endothelial NOS(eNOS),and inducible NOS(iNOS),were visualized with protein A-gold-conjugated secondary antibodies.Stained ultrathin sections were examined and photographed with a Philips CM10 electron microscope equipped with a MEGAVIEW II camera.The specificity of t...