ZX-5对一氧化氮合酶表达和活性的调节作用

目的前期研究表明ZX-5中的一个异构体(R,R)ZX-5,能够促进脉络膜血流和增加NO的释放量。该研究是为了进一步阐明ZX-5是通过上调哪种一氧化氮合酶(NOS)的表达或活性而达到增加NO释放和促进脉络膜血流的作用。方法 Western blot和一氧化氮合酶活性检测试剂盒测定不同一氧化氮合酶表达和酶活性。结果 (S,S)ZX-5能够上调诱导型一氧化氮合酶(iNOS)表达,而不影响内皮型一氧化氮合酶(eNOS)和神经型一氧化氮合酶(nNOS)表达;而(R,R)ZX-5能够上调eNOS表达,并且iNOS表达也有轻微上调作用,但是不改变nNOS的表达;酶活性测定研究发现(S,S)ZX-5仅仅能通过激活iNOS酶活而增加NO释放量;而(R,R)ZX-5也仅仅能够通过激活eNOS的酶活而增加NO释放。结论和(S,S)ZX-5相比,(R,R)ZX-5能够通过上调eNOS表达和活力,增加NO的释放,进而增加脉络膜的血流;因此(R,R)ZX-5也更加适合开发为治疗年龄相关性黄斑变性的药物。     

MG132诱导人血管内皮细胞凋亡及对caspase-3表达的影响

目的　观察蛋白酶体抑制剂MG132对人血管脐静脉内皮细胞(ECV -304)的致凋亡作用及其对凋亡相关的天冬氨酸特异的半胱氨酸蛋白酶3表达的影响。方法　采用两个浓度(2, 5μmol·L-1 )的蛋白酶体抑制剂MG132处理ECV -304细胞;DNA琼脂糖凝胶电泳检测细胞凋亡,流式细胞术检测细胞周期和细胞凋亡率;RT -PCR检测细胞内凋亡相关基因caspase -3的转录水平;免疫细胞化学检测细胞caspase 3蛋白表达。结果　对照组ECV -304细胞凋亡率低于5%,在2μmol·L-1MG132作用下,凋亡率为11. 3%,MG132浓度升至5μmol·L-1,细胞凋亡率增致44 .5%,MG132诱导ECV 304细胞凋亡具有量-效关系;RT -PCR检测发现细胞内凋亡相关基因caspase 3mRNA表达上调;免疫细胞化学检测细胞caspase- 3蛋白表达水平升高。结论:蛋白酶体抑制剂MG132能够诱导血管内皮细胞凋亡,其机制可能与MG132抑制UPP活性,促进caspase- 3基因转录,使细胞内caspase -3增加而促进细胞凋亡。     

血管紧张素Ⅱ和缬沙坦对血管内皮细胞AT_1/AT_2及eNOS表达的调节作用

目的研究缬沙坦在血管内皮细胞中对血管紧张素Ⅱ(AngⅡ)受体I型(AT1)和Ⅱ型(AT2)、一氧化氮合酶(eNOS)的表达和一氧化氮(NO)生成的影响。方法使用人脐静脉内皮细胞系ECV304(HUVECs),分为对照组、AngⅡ组、缬沙坦组和AngⅡ加缬沙坦组,作用不同时间,检测AT1AT2的mRNA和蛋白表达、eNOS的蛋白表达和NO的生成。结果在HUVECs细胞中未检测到AT2的蛋白表达,AngⅡ、缬沙坦均显著抑制细胞中AT1的mRNA和蛋白表达,且缬沙坦呈明显的剂量依赖效应,AngⅡ作用36h显著抑制NO的生成而合用缬沙坦可明显逆转该效应。结论在HUVECs中缬沙坦可通过自身的结合下调AT1,并能逆转AngⅡ长时间作用对NO生成的抑制作用,提示缬沙坦可改善血管内皮细胞的功能。     

何首乌水溶性成分2,3,5,4''-四羟基二苯乙烯-2-O-β-D葡糖苷(ST I)对内皮细胞表达VEGF的影响

目的研究何首乌水溶性成分2,3,5,4'-四羟基二苯乙烯-2-O-β-D葡糖苷(ST I)对溶血磷脂酰胆碱(LPC)诱导人脐静脉内皮细胞株ECV304细胞中血管内皮生长因子(VEGF)表达的影响.方法在ECV304细胞培养基中加入LPC(2.5 mg·L-1)或LPC与ST I共孵24 h,收集各组条件培养基,用基础酶联免疫吸附试验(ELISA)检测各组条件培养基中VEGF蛋白含量;用原位杂交法、RT-PCR及Realtime RT-PCR法检测LPC对内皮细胞VEGFmRNA的表达及ST I的影响.结果ECV304细胞暴露于LPC后,VEGF蛋白分泌明显增加;加入STI后VEGF蛋白含量明显降低;LPC可以使ECV304中VEGF mRNA的表达明显升高,并使VEGF165 mRNA的表达升高;ST I可剂量依赖性地抑制VEGF165 mRNA的高表达.结论LPC能诱导ECV304细胞表达高水平的VEGF蛋白及VEGFmRNA,1×10-5mol·L-1ST I可抑制LPC的作用,降低VEGF的高表达.     

埃他卡林对长期低氧大鼠肺组织eNOS mRNA和蛋白表达的影响

目的研究长期低氧对大鼠肺组织eNOS mRNA及蛋白表达的影响及新型ATP敏感性钾(KATP)通道开放剂埃他卡林(iptakalim,IPT)的作用。方法SD♂大鼠60只,随机分成对照组、低氧组、IPT低剂量组(IPT0.75mg.kg-1.d-1,ig)、IPT高剂量组(IPT1.5mg.kg-1.d-1,ig),每组15只。将低氧组、IPT低剂量和高剂量组大鼠放入常压低氧舱内[O2(10%±0.5%)],每周6d,每天8h,4wk后测定平均肺动脉压(mPAP)、RV/(LV+S)和血浆NO浓度。采用RT-PCR技术,分析各组肺组织eNOS mRNA表达;采用Western blot技术,分析各组肺组织eNOS蛋白表达。结果①低氧组大鼠mPAP和RV/(LV+S)高于对照组,IPT低剂量组和高剂量组较低氧组下降,P均<0.05。②低氧组大鼠血浆NO浓度低于正常对照组,IPT低剂量和高剂量组较低氧组上升,P均<0.05。③低氧组eNOS mRNA及蛋白水平均低于对照组(P<0.05),IPT低剂量和高剂量组eNOS高于低氧组(P<0.05),其中高剂量组更加明显。结论长期低氧导致肺血管内皮细胞功能障碍,NO生成减少、eNOS mRNA和蛋白水平表达下降,而IPT可改善内皮细胞功能障碍,增加eNOS的表达和NO的释放,逆转低氧性肺动脉高压。     

组织型纤溶酶原激活物重组腺病毒载体的构建及其转染ECV304细胞后对血管内皮细胞生长因子表达的影响

目的 评估外源性组织型纤溶酶原激活物(t-PA)对ECV304细胞中血管内皮细胞生长因子(VEGF)表达的影响.方法 应用细菌内同源重组技术快速构建Adt-PA腺病毒重组质粒,转染不同病毒滴度Adt-PA至ECV304细胞,转染比率(MOI)分别为1∶10、1∶50、1∶100,选取合适MOI值;病毒转染后检测ECV304细胞内t-PA蛋白的表达.然后将培养的ECV304细胞分为二组,在培养液中加入Adt-PA混合培养24 h和48 h分别作为实验组1和实验组2,加入空病毒Ad混合培养48 h作为对照组,比较各组细胞中VEGF mRNA的转录和蛋白表达水平.结果 成功构建了重组腺病毒Adt-PA.当MOI为1∶50时,细胞转染效率为(69.6±21.2)%,且对ECV304细胞增殖具有一定的促进作用;Adt-PA转染ECV304细胞后在72 h内随着时间的延长其蛋白表达量逐渐升高(P<0.01);细胞内VEGFmRNA的转录水平和蛋白表达量在实验组1和2中较对照组均有明显升高(P<0.01).结论 构建的t-PA腺病毒表达载体可有效感染ECV304细胞并可显著增加其VEGF的表达水平.     

p38 MAPK通路在TNF-α诱导人脐静脉内皮细胞分泌ET-1与eNOS中的作用及通心络干预影响

目的观察p38 MAPK信号通路在肿瘤坏死因子-α(TNF-α)诱导人脐静脉内皮细胞(HUVEC)表达内皮素-1(ET-1)与内皮型一氧化氮合酶(eNOS)中的作用及通心络干预影响。方法分别采用放免法及ELISA法测定不同浓度TNF-α(0、2.5、5、10、15、20μg·L-1)在不同时间点(0、1、2、4、8、12、24h)干预后HUVEC培养上清液中ET-1和eNOS含量;分别采用Western blot和Realtime RT-PCR方法检测TNF-α干预24h后HUVEC中ET-1、eNOS蛋白及mRNA表达;采用Western blot方法检测TNF-α干预10min、30min、60min后HUVEC磷酸化p38 MAPK蛋白表达。结果不同浓度TNF-α随时间延长均明显增加HUVEC培养上清液中ET-1含量,降低eNOS含量;TNF-α升高细胞中ET-1蛋白及mRNA水平、降低eNOS蛋白及mRNA水平、在各时间点均可升高细胞p-p38 MAPK蛋白表达。通心络可降低TNF-α诱导的HUVEC培养上清ET-1含量、降低细胞中ET-1蛋白及mRNA的异常升高;增加HUVEC培养上清中eNOS的表达、增加细胞中eNOS蛋白及mRNA的表达;明显抑制TNF-α诱导的细胞p-p38 MAPK表达。结论p38 MAPK信号通路参与了TNF-α诱导HUECV细胞分泌ET-1和eNOS,通心络对内皮细胞保护作用机制与抑制该通路有关。     

血管紧张素Ⅱ和缬沙坦对血管内皮细胞AT1/AT2及eNOS表达的调节作用

目的：研究缬沙坦在血管内皮细胞中对血管紧张素Ⅱ(AngⅡ)受体Ⅰ型(AT1)和Ⅱ型(AT2)、一氧化氮合酶(eNOS)的表达和一氧化氮(NO)生成的影响。方法：使用人脐静脉内皮细胞系ECV-304(HUVECs)，分为对照组、AngⅡ组、缬沙坦组和AngⅡ加缬沙坦组，作用不同时间，检测AT1／AT2的mRNA和蛋白表达、eNOS的蛋白表达和NO的生成。结果：在HUVECs细胞中未检测到AT2的蛋白表达，AngⅡ、缬沙坦均显著抑制细胞中AT1的mRNA和蛋白表达，且缬沙坦呈明显的剂量依赖效应，AngⅡ作用36h显著抑制NO的生成而合用缬沙坦可明显逆转该效应。结论：在HUVECs中缬沙坦可通过自身的结合下调AT1，并能逆转AngⅡ长时间作用对NO生成的抑制作用，提示缬沙坦可改善血管内皮细胞的功能。     

抗氧化剂ebselen 对SHRsp冠状动脉eNOS蛋白表达的影响

目的 :研究新型抗氧化剂含硒谷胱甘肽过氧化物酶模拟物PZ5 1对卒中易感型自发性高血压大鼠 (SHRsp)高血压发展的慢性过程中冠状动脉内皮型一氧化氮合成酶 (eNOS)表达的影响。方法 :2 2只8周龄SHRsp随机分为PZ5 1组和对照组 ,灌胃治疗6周。测量心脏重量比值、心脏结构 ;采用分光光度计测心肌组织匀浆一氧化氮 (NO)的浓度 ;免疫组化检测冠状动脉eNOS蛋白表达。结果 :PZ5 1组较对照组心肌组织匀浆NO浓度显著升高 (1.18± 0 .2 5vs 0 .72± 0 .18μmol·mg-1prot ,P <0 .0 5 )、冠状动脉内皮eNOS蛋白表达显著增加 (7.4 5± 2 .10vs 2 .77± 2 .0 7,P <0 .0 5 )。结论 :PZ5 1治疗 6周显著增加了SHRsp冠状动脉eNOS蛋白表达及心肌组织NO的水平。     

阿托伐他汀对人血管内皮细胞E3RSI κB酶mRNA与UBC5酶mRNA表达的影响

目的通过研究阿托伐他汀对人血管内皮细胞泛素系统中E3RSIκB酶mRNA及UBC5酶mRNA表达的影响,探讨其抗炎机制。方法采用逆转录聚合酶链反应方法观察人ECV304细胞泛素蛋白连接酶家族中的E3RSIκB酶及泛素缀合酶中的UBC5酶的mRNA表达情况。结果阿托伐他汀能剂量依赖地抑制脂多糖诱导的人ECV304细胞E3RSIκB酶及UBC5酶的mRNA表达增加,脂多糖组E3RSIκB酶及UBC5酶的mRNA相对表达量分别为4.535±0.779、1.426±0.062;阿托伐他汀0.1μmol.L-1、1μmol.L-1、10μmol.L-1组的E3RSIκB酶及UBC5酶的mRNA相对表达量分别为2.907±0.103、1.726±0.058、0.723±0.079和1.208±0.062、1.103±0.125、0.414±0.039。结论阿托伐他汀能够减轻脂多糖诱导的ECV304细胞E3RSIκB酶及UBC5酶的mRNA表达增加,说明其能通过减少核因子κB抑制因子α的降解抑制核因子κB的活性进而达到抗炎效果。     

丹酚酸B镁盐抑制低氧诱导内皮细胞钙内流和一氧化氮释放

AIM: To investigate the inhibitory effect of magnesium lithospermate B (MLB) on hypoxia-induced elevation of intracellular calcium concentration ([Ca2+]i) and nitric oxide (NO) release in endothelial cells. METHODS: The cultured human umbilical vein endothelial cells (ECV304) were cultured for 30 min under 95 % N(2) and 5 % CO2. Cell injury was evaluated by dye exclusion test and lactate dehydrogenase (LDH) assay. [Ca2+]i was determined by Fura 2-AM. NO content was examined by the NO assay kit. Endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) mRNA expressions were measured by semi-quantitative RT-PCR. RESULTS: Cell viability was decreased from (93.0 +/- 2.6) % in normoxia to (85.5 +/- 2.1) % in hypoxia (P < 0.01), and LDH release was increased from (41 +/- 28) U/L in normoxia to (141+/-68) U/L in hypoxia (P < 0.01) in ECV304 cultured under calcium conditions. MLB 5 and 10 mg/L improved cell viability and inhibited LDH leakage in ECV304. In addition, hypoxia increased [Ca2+]i, NO release, and eNOS and iNOS mRNA expressions in ECV304 (P < 0.01). These increases could be inhibited by MLB 5 and 10 mg/L (P < 0.01), but they were unaffected by hypoxia under calcium-free conditions. CONCLUSION: MLB attenuates hypoxia-induced cell injury and inhibits hypoxia-induced increases of [Ca2+]i, NO release, and eNOS and iNOS mRNA expressions in ECV304 in Krebs'solution containing calcium. The decreases of NO production and eNOS mRNA expression are possibly associated with inhibition of extracellular calcium influx in MLB-treated ECV304     

丹酚酸B镁盐对缺氧复氧内皮细胞内钙和一氧化氮的影响

目的:研究丹酚酸B镁盐对缺氧复氧引起的内皮细胞内钙升高和一氧化氮释放增加的影响.方法:培养的人脐静脉内皮细胞(ECV304)暴露在95％ N_2 5％CO_2条件下缺氧30分钟,后在含5％CO_2的空气中复氧30分钟.内皮细胞的损伤用染料排除实验、SOD的活性和MDA的生成来评价.胞内游离钙浓度用钙荧光探针Fura 2-AM测定.一氧化氮含量用一氧化氮试剂盒测定.内皮型一氧化氮合酶(eNOS)mRNA和诱导型一氧化氮合酶(iNOS)mRNA的表达用半定量逆转录聚合酶链式反应(RT-PCR)检测.结果:缺氧复氧引起内皮细胞的活力由正常条件下(93.1±1.2)％降至(88±3)％(P<0.01),SOD的活性也由(0.24±0.07)kNU/L下降到(0.18±0.03)kNU/L(P>0.05),但其使内皮细胞MDA的生成由(1.12±0.06)mmol/L增至(3.78±0.03)mmol/L(P<0.01).丹酚酸B镁盐2.5,5,10 mg/L能明显降低缺氧复氧引起的内皮细胞MDA生成量的增加,并且显著提高细胞活力和SOD的活性.同时,缺氧复氧还增加内皮细胞的胞内游离钙浓度(F_(340)/F_(380)由 1.65±0.16增至 1.89±0.28)和一氧化氮释放[由(7.5±1.3)μmol/L增至(16±5)μmol/L],并上调其eNOS mRNA的表达,但降低iNOS mRNA的表达(P<0.05).但在无钙的条件下,缺氧复氧对内皮细胞的胞内游离钙浓度、一氧化氮含量、eNOSnRNA和iNOS mRNA表达     

Sodium nitroprusside decreased leukotriene C4 generation by inhibiting leukotriene C4 synthase expression and activity in hepatic ischemia-reperfusion injured rats

The effects of NO on LTC4 generation during hepatic ischemia-reperfusion (I/R) are largely unclear. Sprague-Dawley rats were divided into control, I/R and sodium nitroprusside (SNP, 2.5, 5 and 10 microg/kg/min)+I/R groups. Liver was subjected to I/R injury, saline or SNP administered intravenously. The protein expressions of LTC4 synthesis enzymes including LTC4 synthase (LTC4S), microsomal glutathione-S-transferase (mGST)2 and mGST3 were detected with immunoblotting, the LTC4 synthesis enzymes' activities and LTC4 content were measured by RP-HPLC, the mRNA expressions of inducible nitric oxide synthase (iNOS) and endogenous nitric oxide synthase (eNOS) in liver were measured by RT-PCR. Tissue injuries were assessed by serum ALT and AST and histological changes. Serum NO(2)(-) and liver tissue GSH were also examined. Compared with I/R group, SNP markedly decreased LTC4 content, LTC4S protein and iNOS mRNA levels, and the LTC4 synthesis enzymes' activities (P<0.05), but significantly enhanced eNOS mRNA expression in liver (P<0.05). The decline in serum ALT, AST and NO(2)(-) levels (P<0.05) together with hepatic GSH elevation (P<0.05) in SNP+I/R groups were also observed. LTC4S expression in hepatocytes and sinusoidal endothelial cells in SNP+I/R groups was lower than that in I/R group. But no significant differences in the protein expressions of mGST3 and mGST2 existed between control, I/R and SNP+I/R groups (P>0.05). These results demonstrated that the decline in LTC4 production by SNP treatment during hepatic I/R could be partially resulted from SNP down-regulating the protein expression of LTC4S rather than mGST2 or mGST3 and its inhibiting the LTC4 synthesis enzymes' activities.     

眼镜蛇毒L-氨基酸氧化酶对人膀胱癌ECV304细胞增殖和细胞周期的影响及机制

目的研究眼镜蛇毒L-氨基酸氧化酶(Naja atra L-a-mino acid oxidase,NA-LAAO)对人膀胱癌细胞株ECV304的生长抑制作用,探讨其作用机制。方法 CCK-8法测定NA-LAAO的细胞毒性及对细胞增殖抑制能力;流式细胞术分析NA-LAAO对ECV304细胞周期的影响;实时定量PCR和Western blot分析细胞周期相关基因mRNA和蛋白质表达。结果 NA-LAAO对ECV304细胞有强烈抑制作用,且呈剂量-效应和时间-效应关系。NA-LAAO处理6、12、24 h对ECV304的IC50分别为(1.54±0.23)、(1.09±0.15)和(0.48±0.14)mg.L-1;细胞生长曲线显示,0.156 mg.L-1的NA-LAAO作用4 d可明显抑制ECV304细胞增殖;0.313 mg.L-1从d 2起就有明显效果;0.625 mg.L-1处理后细胞多数死亡;流式细胞术分析提示NA-LAAO可使ECV304细胞阻滞在G1期,并呈量效关系;实时定量PCR结果显示,NA-LAAO可下调Cyclin A2、B1、D1、E1、CDK2、CDK6、Survivin、Skp2,上调p21、p16、p27的表达,Western blot结果显示NA-LAAO可下调Cyclin A、CDK2、CDK6,上调p21,与实时PCR结果一致。结论 NA-LAAO可通过调节细胞周期相关分子,使ECV304细胞阻滞在G1期,抑制细胞增殖。     

溶血磷脂酰胆碱对ECV304细胞中血管内皮生长因子表达的影响(英文)

目的:研究溶血磷脂酰胆碱(LPC)对内皮细胞(EC)中血管内皮生长因子(VEGF)表达的影响。方法:在人脐静脉内皮细胞株ECV04培养基中加入不同浓度的LPC,培养不同时间,用基础酶联免疫吸附实验(ELISA)检测各组EC条件培养基中VEGF蛋白含量;用免疫组织化学法检测EC中VEGF蛋白及其受体的表达;用原位杂交检测VEGF信使核糖核酸(VEGF mRNA)的表达。结果:培养的ECV304能表达VEGF受体,在胞浆内呈棕色颗粒,当LPC刺激后,阳性增强。原位杂交结果显示,培养的ECV304中未见VEGF mRNA的表达,当LPC刺激后可见VEGF mRNA的高表达,在胞浆内呈棕色颗粒。ELISA结果显示LPC可使ECV304条件培养基中VEGF蛋白含量明显增加,且具有时间和剂量依赖性。结论:LPC能诱导ECV304表达高水平的VEGF。 (责任编辑 吕静)     

何首乌水溶性成分2,3,5,4′-四羟基二苯乙烯-2-O-β-D葡糖苷(ST I)对内皮细胞表达VEGF的影响何首乌水溶性成分2,3,5,4′-四羟基二苯乙烯-2-O-β-D葡糖苷(ST I)对内皮细胞表达VEGF的影响

目的研究何首乌水溶性成分2,3,5,4′-四羟基二苯乙烯-2-O-β-D葡糖苷(ST I)对溶血磷脂酰胆碱(LPC)诱导人脐静脉内皮细胞株ECV304细胞中血管内皮生长因子(VEGF)表达的影响。方法在ECV304细胞培养基中加入LPC(2.5 mg·L^-1)或LPC与ST I共孵24 h，收集各组条件培养基，用基础酶联免疫吸附试验(ELISA)检测各组条件培养基中VEGF蛋白含量；用原位杂交法、RT-PCR及Realtime RT-PCR法检测LPC对内皮细胞VEGF mRNA的表达及ST I的影响。结果ECV304细胞暴露于LPC后，VEGF蛋白分泌明显增加；加入ST I后VEGF蛋白含量明显降低; LPC可以使ECV304中VEGF mRNA的表达明显升高, 并使VEGF165 mRNA的表达升高；ST I可剂量依赖性地抑制VEGF165 mRNA的高表达。结论LPC能诱导ECV304细胞表达高水平的VEGF蛋白及VEGF mRNA，1×10^-5 mol·L^-1 ST I可抑制LPC的作用，降低VEGF的高表达。     

Sodium nitroprusside regulates mRNA expressions of LTC4 synthesis enzymes in hepatic ischemia/reperfusion injury rats via NF-kappaB signaling pathway

Leukotriene (LT) C4 (LTC4) synthesis enzymes including LTC4 synthase (LTC4S), microsomal glutathione S-transferase (MGST) 2 and MGST3 can all conjugate LTA4 and reduced glutathione (GSH) to form LTC4, which is related to hepatic ischemia/reperfusion (I/R) injury. The relationship between nitric oxide (NO) and cysteinyl LTs has been shown in previous studies. However, the mechanisms of NO action on gene expression of LTC4 synthesis enzymes are still largely unclear during hepatic I/R. Adult male Sprague-Dawley rats were divided into 5 groups: a sham group (control), an I/R group, and sodium nitroprusside (SNP, 2.5, 5 and 10 microg/kg/min)+I/R groups. Livers were subjected to 60 min of partial hepatic ischemia followed by 5 h of reperfusion, saline or SNP (2.5, 5 and 10 microg/kg/min) administered intravenously. The mRNA levels of LTC4 synthesis enzymes, inducible NO synthase (iNOS) and endothelial No synthase (eNOS) in rat liver tissue were examined by RT-PCR; the protein expressions of NF-kappaB p65, p50 and IkappaBalpha in liver cell lysates and nuclear extracts were detected by Western blot analysis, and serum NO2. levels were also evaluated. Serum NO2. levels, the protein expressions of NF-kappaB p65 and p50 in the nucleus extract, and hepatic mRNA expressions of LTC4S and iNOS were decreased while hepatic mRNA of eNOS was increased in the SNP (5 and 10 microg/kg/min)+I/R groups when compared with those in the I/R group. SNP (2.5 microg/kg/min) promoted the mRNA expressions of both MGST2 and MGST3, whereas SNP (10 microg/kg/min) increased MGST2 mRNA but decreased MGST3 mRNA compared to those in I/R group. Compared with control, the mRNA expression of MGST2 and MGST3 were elevated in SNP (2.5 microg/kg/min)+I/R group, MGST3 mRNA was significantly declined in the SNP (5 and 10 microg/kg/min)+I/R groups. Immunohistochemistry staining revealed that I/R liver exhibited strong cytoplasmic and nuclear staining for NF-kappaB p65, but the livers of the SNP (2.5 microg/kg/min)+I/R group presented slight cytoplasmic and nuclear staining. But IkappaBalpha protein in all groups remains unchanged. It was concluded that SNP downregulated LTC4S mRNA expression by inhibiting NF-kappaB activation independent of IkappaBalpha, but appeared to have a dual influence on the mRNA expressions of MGST2 and MGST3 by other signaling pathways during hepatic I/R injury.     

N-acetylcysteine attenuates TNF-alpha-induced human vascular endothelial cell apoptosis and restores eNOS expression

The circulatory inflammatory cytokine tumor necrosis factor-alpha (TNF-alpha) is increased in pathological conditions, such as diabetes, which initiate or exacerbate vascular endothelial injury. Both nitric oxide (NO) and reactive oxygen species may play a dual role (i.e., inhibiting or promoting) in TNF-alpha-induced endothelial cell apoptosis. We investigated the effects of the antioxidant N-acetylcysteine on TNF-alpha-induced apoptosis in human vascular endothelial cell (cell line ECV304) apoptosis, NO production and lipid peroxidation. Cultured vascular endothelial cell (ECV304) were either not treated (control), or treated with TNF-alpha (40 ng/ml) alone or TNF-alpha in the presence of N-acetylcysteine at 30 mmol/l or 1 mmol/l, respectively, for 24 h. Cell viability was measured by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay. Cell apoptosis was assessed by flow cytometry. TNF-alpha-induced endothelial cell apoptosis was associated with increased inducible NO synthase but reduced endothelial NO synthase (eNOS) protein expression. NO production and the levels of the lipid peroxidation product malondialdehyde were concomitantly increased. Treatment with NAC at 30 mmol/l restored eNOS expression and further increased NO production as compared to TNF-alpha alone, resulting in improved cell viability and reduced apoptosis. This was accompanied by increased superoxide dismutase activity, increased glutathione peroxidase production and reduced malondialdehyde levels. N-acetylcysteine at 1 mmol/l, however, did not have significant effects on TNF-alpha-induced endothelial cell apoptosis and cell viability despite it slightly enhanced glutathione peroxidase production. N-acetylcysteine attenuation of TNF-alpha-induced human vascular endothelial cell apoptosis is associated with the restoration of eNOS expression.     

吡格列酮对大鼠尿酸钠晶体诱导的炎症组织细胞中S100A8和S100A9的mRNA表达的影响

目的为进一步了解吡格列酮的抗炎机制,观察其对炎症组织细胞中免疫及炎性调节因子S100A8和S100A9的mRNA表达的影响,探讨其痛风防治作用机制。方法大鼠单侧踝关节腔一次性注射尿酸钠(MSU)晶体建立急性痛风性关节炎模型;腹腔一次性注射MSU诱导急性腹膜炎模型。MSU注射诱发模型前3d,大鼠灌胃口服吡格列酮(20mg.kg-1.d-1),连续给药5d;模型诱发当天,在吡格列酮给药后2h注射MSU。以RT-PCR检测关节炎诱发后48h滑膜组织中和腹膜炎诱发后4,8,24,48及72h腹腔巨噬细胞S100A8和S100A9的mRNA的表达以及吡格列酮给药的影响。结果S100A8和S100A9的mRNA在正常大鼠滑膜中仅有微量表达(0.01±0.01,0.20±0.07),但在诱发关节炎后48h,滑膜组织中呈现高表达(1.21±0.20,1.44±0.20),吡格列酮则显著抑制其高表达(0.26±0.14,0.25±0.16)。S100A8和S100A9的mRNA在正常大鼠腹腔巨噬细胞未见表达,但在诱发腹膜炎后4,8,24,48和72h大鼠腹腔巨噬细胞中均有较高表达。吡格列酮仅在48和72h显示出明显的抑制作用(S100A8mRNA:1.17±0.38vs0.03±0.02和0.70±0.20vs0.02±0.01;S100A9mRNA:0.90±0.31vs0.10±0.01和0.77±0.10vs0.02±0.01)。结论吡格列酮具有抑制S100A8和S100A9的mRNA表达的作用,很可能与其对痛风炎症的防治作用密切相关。