NADPH氧化酶在次氯酸修饰白蛋白诱导血管内皮细胞炎性反应中的作用

目的 阐明次氯酸修饰白蛋白（HOCl-Alb）诱导血管内皮细胞炎性反应的机制。 方法 用体外制备的HOCl-Alb与人脐静脉内皮细胞共同培养;用光泽精增强化学发光法测定NADPH氧化酶活性;用免疫沉淀和Western印迹法测定p47phox磷酸化及p47phox与p22phox结合;用免疫荧光化学染色法观察p47phox膜迁移;分别用RT-PCR和Western印迹法测定细胞间黏附分子1（ICAM-1） mRNA和蛋白表达。为了解NADPH氧化酶在HOCl-Alb上调ICAM-1表达过程中的作用,在HOCl-Alb刺激细胞前,在细胞培养液中预先加入NADPH氧化酶特异性抑制剂夹竹桃麻素（apocynin）,观察ICAM-1表达的变化。 结果 HOCl-Alb激活NADPH氧化酶具有剂量和时间依赖性,200 mg/L HOCl-Alb刺激15 min使NADPH氧化酶活性增加的量是牛血清白蛋白组的6.16倍（P ＜ 0.01）,并可诱导p47phox磷酸化和膜迁移,及其与p22phox结合。HOCl-Alb上调ICAM-1表达的作用可被夹竹桃麻素抑制,500 μmol/L 夹竹桃麻素对HOCl-Alb诱导的ICAM-1表达的抑制率为68.97%（P ＜ 0.01）。 结论 NADPH氧化酶是HOCl-Alb诱导ICAM-1高表达的重要途径,与血管内皮炎性反应关系密切。     

福辛普利对糖尿病大鼠肾脏NADPH氧化酶p22phox亚基mRNA表达的影响

目的 观察福辛普利对链脲佐菌素(STZ)诱导的糖尿病大鼠肾脏还原型辅酶Ⅱ(NADPH)氧化酶p22phox 亚基mRNA表达及细胞外基质（ECM）聚积的影响，并探讨其可能机制。 方法 STZ诱导的糖尿病大鼠模型，随机分为糖尿病非治疗组（DM组）和福辛普利治疗组（DM+Fosin组，福辛普利10 mg·kg-1·d-1），疗程12周。RT-PCR法检测肾脏NADPH氧化酶p22phox mRNA的表达；免疫组织化学方法检测肾脏纤连蛋白（FN）表达；白明胶酶谱法检测肾脏基质金属蛋白酶9（MMP-9）的活性；并检测Scr、尿蛋白排泄量和肾质量指数等指标。 结果 实验第4 周，DM+Fosin组大鼠肾脏NADPH氧化酶p22phox mRNA表达较DM组减少45％（P ＜ 0.05）。第8周时，DM+Fosin组的肾小球和肾小管间质FN表达较DM组分别降低52.5％和42.9％（均P ＜ 0.05）；肾脏MMP-9的活性升高29.6％（P ＜ 0.05）。实验第12周时，DM+Fosin组大鼠Scr水平、尿蛋白量（24 h）和肾质量指数较DM组分别降低35.9％、50.2％和17.2％（均P ＜ 0.05）。DM+Fosin组和DM组血糖的差异无统计学意义（P ＞ 0.05）。 结论 福辛普利可延缓糖尿病肾病的发生和发展，其机制可能与通过抑制NADPH氧化酶p22phox亚基mRNA的表达有关。     

兔髂动脉再狭窄与NADPH氧化酶的关系

目的研究NADPH氧化酶与血管壁活性氧(ROS)生成及再狭窄的关系。方法构建兔髂动脉2次损伤后再狭窄模型,逆转录-聚合酶链反应(RT-PCR)检测2次损伤后不同时段兔髂动脉NADPH氧化酶催化亚基gp91phox和p22phox mRNA表达的变化;原位杂交观察gp91phox和p22phox mRNA表达在血管壁的定位。结果gp91phox mRNA的表达在2次损伤后逐渐上升,在14 d(1．554±0．105)、28 d(1．444±0．360)达到峰值,与术后即刻组(0．572±0．018)比较,差异有统计学意义(P<0．01);p22phox mRNA的表达在2次损伤即刻(1．514±0．036)即处于高水平,术后1 d(0．832±0．059)略有下降后又逐渐升高,并在14 d(1．714±0．249)、28 d(1．564±0．151)达峰值。在2次损伤后,各时段血管壁gp91phox和p22phox mRNA均可见阳性表达,其表达主要位于新生内膜和外膜。结论NADPH氧化酶各个亚基在再狭窄过程中可能行使不同功能;氧化酶主要在新生内膜与外膜发挥作用。     

NADPH氧化酶在转化生长因子β1诱导大鼠肾小管上皮细胞转分化中的作用

目的探讨NADPH氧化酶在转化生长因子β1（TGF-β1）诱导大鼠肾小管上皮细胞（NRK-52E）转分化中的作用。方法用TGF-β1（10μg/L）刺激NRK-52E细胞不同时间,观察α-平滑肌肌动蛋白（α-SMA）、E-钙黏蛋白（E-cadherin）、纤溶酶原激活物抑制剂1（PAI- 1）及Ⅰ型胶原（Col-Ⅰ）的表达。部分实验中细胞在TGF-β1刺激前用NADPH氧化酶抑制剂DPI预处理1 h。用激光共聚焦显微镜观察细胞内活性氧（ROS）的产生。用RT-PCR方法检测NADPH氧化酶p22phox、gp91phox、p47phox和p67phox亚单位mRNA的表达。α-SMA、E-cadherin、PAI-1及Col-ⅠmRNA及蛋白的表达分别采用RT-PCR、Western印迹和细胞免疫化学检测。结果TGF-β1可显著上调NADPH氧化酶p67phox亚单位mRNA的表达,8 h及24 h时分别为对照组的2.43倍及3.59倍（P〈0.01）。TGF-β1可显著促进细胞ROS的产生,5 min时已是对照组的2.5倍（P〈0.05）。DPI预处理同时可显著逆转TGF-β1诱导NRK-52E细胞ROS的产生（P〈0.05）、α-SMA的表达上调、E-cadherin的表达下调以及PAI-1和Col-Ⅰ的表达上调。结论TGF-β1可促进NRK-52E细胞增加ROS的产生。ROS介导了TGF-β1诱导NRK-52E细胞的转分化,促进肾脏纤维化。     

氯沙坦对血管紧张素Ⅱ诱导大鼠肾小管上皮细胞氧化应激反应的作用

目的 探讨血管紧张素I型受体阻断剂氯沙坦对血管紧张素Ⅱ（AngⅡ）诱导的大鼠肾小管上皮细胞氧化应激反应及转化生长因子β1(TGF-β1)产生的影响。 方法 以大鼠肾小管上皮细胞株（NRK-52E）为研究对象,分别给予氯沙坦（10-5 mol/L）和（或）NADPH氧化酶抑制剂联二亚苯碘锚（DPI,10-5 mol/L）预处理1 h后再加入AngⅡ（10-7 mol/L）刺激24 h,同时设立空白培养基作为对照组。实时定量PCR和Western印迹法分别检测4组细胞NADPH 氧化酶p22phox、p47phox、Nox-4 mRNA和蛋白水平及TGF-β1 mRNA水平。用2,7- 二氯荧光素双乙酸盐（H2DCF-DA）作为荧光探针,采用荧光分光光度仪检测细胞内活性氧（ROS）的水平。应用比色法测定细胞上清液中超氧化物歧化酶（SOD）水平。 结果 AngⅡ（10-7 mol/L）刺激细胞15 min后开始产生大量的ROS,至60 min达平台期。单纯AngⅡ刺激1 h后,NRK-52E细胞上清液中SOD水平显著低于对照组（27.31 μU/L 比48.29 μU/L,P < 0.01）;经氯沙坦预处理1 h后再加入AngⅡ刺激1 h细胞上清液中SOD水平升高至36.37 μU/L,与AngⅡ组差异有统计学意义（P < 0.01）。单纯AngⅡ刺激NRK-52E细胞24 h可显著上调NADPH氧化酶p22phox、p47phox和Nox-4 mRNA和蛋白水平,其mRNA水平分别为对照组的5.57倍、5.55倍和9.41倍（均P < 0.01）,蛋白水平分别为对照组的4.53倍、4.17倍和6.50倍（均P < 0.01）。经氯沙坦干预后,p22phox、p47phox和Nox-4 mRNA水平分别为对照组的2.71倍、2.18倍和5.23倍（均P < 0.01）,蛋白水平分别为对照组的3.20倍、2.30倍和4.30倍（均P < 0.01）。AngⅡ刺激细胞24 h后TGF-β1 mRNA表达也显著增多,为对照组的4.36倍（P < 0.01）,氯沙坦处理细胞后TGF-β1 mRNA水平为对照组的1.57倍。 结论 氯沙坦通过抑制NADPH氧化酶的表达和增加SOD的表达减少ROS的产生,并能通过减少ROS产生,抑制AngⅡ诱导的TGF-β1 mRNA水平增高。     

NADPH氧化酶介导血管紧张素Ⅱ诱导的腹膜间皮细胞转分化及细胞外基质积聚

目的 探讨NADPH氧化酶在血管紧张素(Ang)Ⅱ诱导的腹膜间皮细胞转分化以及细胞外基质积聚中的作用。 方法 体外培养SD大鼠原代腹膜间皮细胞，静止24 h后，随机分为以下4组：正常对照组，AngⅡ（10^-7 mol/L）组，AngⅡ+ Los(洛沙坦,10 μmol/L)组及AngⅡ+DPI（NADPH氧化酶活性抑制剂，10 μmol/L）组。应用荧光染料（DCF）及激光共聚焦显微镜检测细胞内活性氧（ROS）的产生。RT-PCR检测NADPH氧化酶亚单位p47phox以及纤溶酶原激活物抑制剂（PAI）1、α平滑肌肌动蛋白（SMA）、E钙黏蛋白（cadherin） mRNA的表达。Western印迹检测p47phox、α-SMA的蛋白表达。 结果 （1）外源性AngⅡ可显著增加大鼠腹膜间皮细胞ROS的产生，刺激15 min后，ROS 的表达较对照组上升了(3.64±0.53)倍。DPI和洛沙坦可显著抑制AngⅡ刺激后ROS的产生（P < 0.05）。（2）AngⅡ刺激腹膜间皮细胞后， NADPH氧化酶亚单位p47phox mRNA和蛋白的表达均呈上升趋势。洛沙坦和DPI可阻断由AngⅡ诱导的p47phox表达上调（P < 0.05）。（3） AngⅡ诱导α-SMA表达的上调以及 E-cadherin mRNA的下调, 洛沙坦和DPI可部分逆转AngⅡ的这种作用。（4）AngⅡ刺激8 h后可明显上调PAI-1的mRNA表达，为正常对照组的（3.06±0.77）倍。 洛沙坦和DPI可明显阻断PAI-1的表达上调（P < 0.05）。 结论 NADPH氧化酶依赖产生的ROS介导了AngⅡ诱导的腹膜间皮细胞转分化及细胞外基质积聚。阻断AngⅡ的作用及抑制NADPH氧化酶的表达和活性可作为防治腹膜纤维化的潜在治疗靶点。     

氧化应激及丝裂原活化蛋白激酶在醛固酮加盐诱导肾脏损害中的作用

目的 探讨氧化应激与丝裂原活化蛋白激酶（MAPKs)在醛固酮加盐诱导肾脏损伤中的作用。 方法 SD大鼠随机分为以下5组: ⑴ 0.5%乙醇作为对照组； ⑵ 1%氯化钠+0.5%乙醇（氯化钠组）； ⑶ 1%氯化钠+醛固酮+0.5%乙醇（醛固酮组）；⑷ 1%氯化钠+醛固酮+0.5%乙醇+依普利酮（依普利酮组），⑸ 1%氯化钠+醛固酮+0.5%乙醇+超氧化物歧化酶模拟物tempol（tempol组）。实时定量PCR检测肾皮质NADPH氧化酶亚基p22phox、Nox-4 和 gp91phox mRNA水平。Western印迹检测肾皮质磷酸化ERK1/2、JNK及ERK5蛋白表达。 结果 与氯化钠组大鼠相比，醛固酮组大鼠的血压[（165±5）比（118±3） mm Hg]及尿蛋白量（24 h） [(101.0±24.0) 比 (9.1±3.0) mg]显著增高(P均 < 0.05)；肾皮质脂类过氧化反应产物（TBARS）水平明显升高[(0.23±0.02) 比 (0.09±0.01) nmol/mg 蛋白，P < 0.05]；肾皮质NADPH氧化酶亚基p22phox、Nox-4和 gp91phox mRNA表达显著升高[分别为氯化钠组的(2.3±0.2)、(4.3±0.8)和(3.0±0.3)倍，P < 0.05]；肾皮质ERK1/2、JNK与ERK5活性显著增高[分别为氯化钠组的(3.3±0.3)、(2.3±0.3)和(3.0±0.2)倍，P < 0.05]。依普利酮或tempol明显降低醛固组大鼠的血压、尿蛋白量（24 h） [依普利酮组和tempol组分别为(10.0±2.0)、(9.3±2.0) mg]以及肾皮质TBARS水平[依普利酮组和tempol组分别为(0.08±0.01)和(0.11±0.03) nmol/mg 蛋白] (P < 0.05)；并使肾皮质组织ERK1/2、JNK及ERK5活性降至接近对照组水平。 结论 氧化应激与MAPKs通路激活在醛固酮加盐诱导的肾脏损伤中发挥重要作用。     

奥美沙坦酯对慢性心力衰竭小鼠肾脏氧化应激的作用

目的 探讨奥美沙坦酯对慢性心力衰竭小鼠肾脏氧化应激的作用。 方法 健康C57小鼠分为假手术组（SHAM组）、慢性心力衰竭组（CHF组）和奥美沙坦酯治疗组（OLM组）。以冠状动脉左前降支结扎法建立慢性心力衰竭小鼠模型，其中奥美沙坦酯治疗组以10 mg/kg剂量每日胃饲，12周时观察各组小鼠心率、血压、心功能状况、Scr、BUN、血浆和肾脏血管紧张素（Ang）Ⅱ水平。实时PCR法检测肾脏gp91phox、p22phox和NOX4的表达。AZAN染色和二氢乙啶（DHE）染色观察肾组织病理变化。 结果 与SHAM组比较，CHF组和OLM组左室舒张末期内径（LVDd）和左室收缩末期内径（LVDs）显著增加（P ＜ 0.05）；短轴缩短率（FS）和射血分数（EF）显著降低（P ＜ 0.05）；CHF组收缩压、Scr和BUN显著增高，而OLM组以上指标较CHF组均显著降低（P ＜ 0.05）。与SHAM组比较，CHF组血浆和肾脏AngⅡ水平增高，gp91phox、p22phox和NOX4表达增高（P ＜ 0.05）；OLM组肾脏AngⅡ水平、gp91phox、p22phox和NOX4表达较CHF组均显著降低（P ＜ 0.05）。与SHAM组比较，CHF组肾脏AZAN染色和DHE染色阳性增强（P ＜ 0.05），而OLM组较CHF组显著降低（P ＜ 0.05）。 结论 慢性心力衰竭可使肾内NADPH氧化酶激活并导致肾小球间质纤维化，奥美沙坦酯通过抑制AngⅡ引起的氧化应激反应起到肾脏保护作用。     

红细胞生成素对糖尿病大鼠肾脏保护作用的机制

目的 观察红细胞生成素（EPO）对糖尿病大鼠的肾脏保护作用,并探讨其发挥肾脏保护作用的可能机制。 方法 将实验大鼠随机分为正常对照组（NC组）、糖尿病模型组（DM组）和EPO治疗组（DE组）。药物干预8周后,处死大鼠,检测尿白蛋白排泄率（UAER）、血清肌酐（Scr）、血细胞比容（Hct）。肾组织切片行HE、PAS染色,观察大鼠肾脏病理改变。化学比色法检测肾脏丙二醛（MDA）含量、超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-Px）活性及总抗氧化能力（T-AOC）。免疫荧光及Western印迹法检测大鼠肾脏EPO受体（EPOR）的表达。免疫组织化学及Western印迹法检测大鼠肾脏NADPH氧化酶亚基（p47phox）、转化生长因子β1（TGF-β1）、纤连蛋白（FN）的表达。 结果 EPO可以减轻糖尿病大鼠肾脏病理及功能改变。各组大鼠肾脏均表达EPOR,但表达水平比较差异无统计学意义（P ＞ 0.05）。与NC组相比,DM组大鼠p47phox、TGF-β1、FN蛋白表达增强（均P ＜ 0.01）;GSH-Px、SOD活性及T-AOC下降（均P ＜ 0.01）;MDA含量增加（P ＜ 0.01）。与DM组相比,DE组大鼠p47phox、TGF-β1、FN蛋白表达减弱（均P ＜ 0.05）;GSH-Px、SOD活性及T-AOC升高（均P ＜ 0.01）;MDA含量降低（P ＜ 0.01）。 结论 EPO可通过抑制糖尿病大鼠肾脏氧化应激,降低TGF-β1、FN表达,减轻糖尿病大鼠肾脏病理改变,发挥肾脏保护作用。     

黄芪当归合剂对梗阻性肾病大鼠肾组织活性氧的抑制作用

目的 利用梗阻性肾病大鼠模型探讨黄芪当归合剂（A&A）对肾间质纤维化过程中活性氧生成和清除的影响及其相关机制。 方法 雄性Wistar大鼠随机分为对照、假手术（Sham）、模型（UUO）和模型+A&A治疗（UAA）组。UAA组给予A&A（相当于黄芪和当归生药各14 g&#8226;kg-1&#8226;d-1）灌胃,Sham和UUO组给予等量清水。造模后第3天观察肾脏组织标本病理损伤程度;分光光度法测定肾组织匀浆总抗氧化能力（T-AOC）、CuZn超氧化物歧化酶（CuZn-SOD）活力;Western 印迹方法分析肾组织中NADPH氧化酶亚基p47-phox、p22-phox及硝基酪氨酸的表达。 结果 UUO组出现严重间质炎性细胞浸润伴轻微肾小管萎缩及间质纤维化,A&A减轻了肾脏病理损伤。与Sham组相比,UUO组T-AOC无明显变化,但硝基酪氨酸、NADPH氧化酶亚基p47-phox和p22-phox表达显著上调（P < 0.05）。与UUO组相比,UAA组T-AOC表达上调（2.5±1.1比1.5±0.5,P < 0.05）;硝基酪氨酸表达下调（P < 0.05）;NADPH氧化酶p47-phox、p22-phox表达均下调（均P < 0.05）;而CuZn-SOD无明显变化。 结论 梗阻性肾病中,A&A通过抑制肾组织NADPH氧化酶亚基p47-phox和p22-phox表达,减少活性氧的生成;减轻肾组织氧化损伤;抑制肾间质纤维化。     

Effects of NADPH oxidase inhibitor in diabetic nephropathy

BACKGROUND: We used apocynin to test the hypothesis that superoxide anion (O(-) (2)) from nicotinamide adenine dinucleotide phosphate (NADPH) oxidase underlies the development of diabetic nephropathy in the rat. METHODS: Rats received apocynin (16 mg/kg/day) from 2 to 8 weeks after inducing diabetes mellitus (DM) with streptozotocin. RESULTS: DM increased excretion of hydrogen peroxide (H(2)O(2)), lipid peroxidation products (LPO), nitric oxide products (NOx), and protein. The kidneys of rats with DM had increased expression of p47phox and gp91phox and endothelial nitric oxide synthase (eNOS), and increased mesangial matrix with expression of fibronectin and collagen I. Apocynin prevented the increase in excretion of H(2)O(2), LPO, and protein in diabetic rats, increased renal NOx generation, and prevented the increased renal expression of gp91phox and the membrane fraction of p47phox, and reverted the mesangial matrix expansion. CONCLUSION: Activation of NADPH oxidase with translocation of p47phox to the membrane underlies the oxidative stress and limited NO generation, despite enhanced eNOS expression in a model of diabetic nephropathy. Apocynin prevents these changes and the associated proteinuria.     

Taurine protected kidney from oxidative injury through mitochondrial-linked pathway in a rat model of nephrolithiasis

Hyperoxaluria and crystal deposition induce oxidative stress (OS) and renal epithelial cells injury, both mitochondria and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase are considered as the main sources of reactive oxygen species (ROS). Taurine is known to have antioxidant activity and shows renoprotective effect. We investigate the effect of taurine treatment on renal protection, and the putative source of ROS, in a rat model of calcium oxalate nephrolithiasis. Rats were administered with 2.5% (V/V) ethylene glycol + 2.5% (W/V) ammonium chloride (4 ml/day), with restriction on intake of drinking water (20 ml/day) for 4 weeks. Simultaneous treatment with taurine (2% W/W, mixed with the chow) was performed. At the end of the study, indexes of OS and renal injury were assessed. Renal tubular ultrastructure changes were analyzed under transmission electron microscopy. Crystal deposition in kidney was scored under light microscopy. Angiotensin II in kidney homogenates was determined by radioimmunoassay. Expression of NADPH oxidase subunits p47phox and Nox-4 mRNAs in kidney was evaluated by real time-polymerase chain reaction. The data showed that oxidative injury of the kidney occurred in nephrolithiasis-induced rats. Hyperplasia of mitochondria developed in renal tubular epithelium. The activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in mitochondria decreased and the mitochondrial membrane showed oxidative injury. Taurine treatment alleviated the oxidative injury of the kidney, improved SOD and GSH-Px activities, as well as the mitochondrial membrane injury, with lesser crystal depositions in the kidney. We could not detect statistical changes in the renal angiotensin II level, and the renal p47phox and Nox-4 mRNAs expression in those rats. The results suggest that mitochondria but not NADPH oxidase may account for the OS and taurine protected kidney from oxidative injury through mitochondrial-linked pathway in this rat model.     

NADPH氧化酶抑制剂apocynin对大鼠糖尿病肾小球细胞外基质代谢的影响

目的探讨NADPH氧化酶亚基p22phoxmRNA在糖尿病大鼠肾脏表达时间模式及抑制NADPH氧化酶活性对肾小球细胞外基质(ECM)代谢的影响。方法链脲佐菌素诱导的大鼠糖尿病模型随机地分为糖尿病非治疗组(DM),观察12周;NADPH氧化酶抑制剂apocynin治疗组(DM+Apo,0.2g·kg-1·d-1),疗程8周。用RT-PCR检测肾脏NADPH氧化酶亚基p22phoxmRNA的表达。免疫组织化学检测肾脏纤连蛋白(FN)表达。白明胶酶谱法(zymography)检测肾脏基质金属蛋白酶-9(MMP-9)的活性。并测定Scr、尿蛋白量和肾重指数。结果DM组肾脏p22phoxmRNA的表达在4、6和8周时较正常对照组(C)明显升高(P<0.05);12周时降低至正常水平。DM+Apo组肾脏p22phoxmRNA的表达与DM组差异无统计学意义(P>0.05),但可显著逆转由糖尿病导致的肾小球体积、肾小球FN表达、肾小球ECM含量、Scr、尿蛋白量和肾重指数的升高(P<0.05),并显著提高肾脏MMP-9活性(P<0.05)。结论NADPH氧化酶的过度表达在糖尿病肾病(DN)发病的早期阶段起重要作用。抑制NADPH氧化酶活性的治疗措施可减少DN肾小球ECM积聚、延缓DN的发生和发展。     

Why does atorvastatin inhibit renal crystal retention?

Recently, we reported that atorvastatin prevents renal tubular cell injury by oxalate and inhibits renal crystal retention. In this study, we investigated the mechanism by which atorvastatin inhibits renal crystal retention. Male Sprague-Dawley rats were separated into four experimental groups, and the ethylene glycol model of hyperoxaluria and the atorvastatin treatment model were analyzed. To clarify the mechanism by which atorvastatin inhibits renal crystal retention, the removed kidneys were used for the quantitative analysis of superoxide dismutase (SOD) and catalase. The subunits of the NADPH oxidase system were evaluated using real-time polymerase chain reaction analysis. Furthermore, the level of transforming growth factor-β (TGF-β) in kidney tissue was compared in each group. Atorvastatin treatment increased the SOD and catalase level compared with the stone-forming control group. Atorvastatin treatment decreased the expression of NOX-1 mRNA. Furthermore, the level of TGF-β was suppressed by atorvastatin treatment. We found that atorvastatin have inhibited calcium oxalate (CaOX) urolithiasis formation. We hypothesize that the mechanism of action of atorvastatin involves inhibiting TGF-β and NADPH oxidase, and increasing the SOD and catalase level. We believe that atorvastatin will be helpful in the treatment of CaOX urolithiasis.     

Apocynin attenuates tubular apoptosis and tubulointerstitial fibrosis in transgenic mice independent of hypertension

Angiotensin II stimulates the formation of reactive oxygen species by increased NADPH oxidase activity, which contributes to proapoptotic and profibrotic mechanisms critical in renal injury. Here we determine if apocynin, an inhibitor of NADPH oxidase, interferes with the action of the intrarenal renin-angiotensin system to minimize the progression of renal disease. Transgenic mice that overexpress rat angiotensinogen in their proximal tubule cells were given either apocynin, perindopril, or hydralazine while untreated or apocynin-treated non-transgenic littermates served as controls. Untreated transgenic mice had significant elevations of their systolic blood pressure, albuminuria, reactive oxygen species production, NADPH oxidase activity, tubular apoptosis, active caspase-3, Bax, transforming growth factor-beta1, plasminogen activator inhibitor-1, extracellular matrix proteins, collagen type IV, and phosphorylated p47phox expression compared to untreated non-transgenic mice. Apocynin and perindopril blunted these changes; however, apocynin had no effect on the systolic blood pressure whereas hydralazine prevented hypertension and tubulointerstitial fibrosis but not proximal tubule cell apoptosis. Our study shows that the intrarenal renin-angiotensin system stimulates proximal tubule cell apoptosis and tubulointerstitial fibrosis, in part, by enhanced NADPH oxidase activity and reactive oxygen species generation independent of systemic hypertension.     

罗格列酮对慢性环孢素肾病大鼠肾间质纤维化的保护作用

目的 探讨罗格列酮(RGZ)对环孢素A(CsA)所致慢性环孢素肾病(CCN)大鼠肾间质纤维化的保护作用.方法 28只健康雄性SD大鼠被随机分成4组:(1)对照组(n=6):低盐饮食(LSD); (2)RGZ组(n=6):LSD+RGZ(5 mg·kg-1·d-1);(3)CsA组(n=8):LSD+CsA(15 mg·kg-1·d-1),(4)RGZ+CsA组(n=8):LSD +CsA(15 mg·kg-1·d-1)+RGZ(5 mg·kg-1 ·d-1).实时荧光定量PCR观察骨调素(OPN)及RANTES表达量;RT-PCR法检测MMP-9和TIMP-1的表达量;常规染色观察肾脏病理改变.结果 RGZ可改善CsA所致大鼠肌酐清除率的降低[(0.253±0.027)比(0.133±0.018) ml/min,P＜0.05];降低CCN大鼠肾间质单个核细胞浸润[(22.50±2.71)比(30.38±3.11),P＜0.05];减轻肾间质纤维化程度[(1.707±0.019)比(2.335±0.022),P＜0.05].与CsA组比较,RGZ+CsA组大鼠肾组织中OPN和RANTES mRNA表达量和MMP-9、TIMP-1 mRNA表达量降低(均P＜0.05).结论 RGZ可能通过下调趋化因子OPN、RANTES及MMP-9、TIMP-1的表达,改善CCN大鼠肾间质纤维化.     

Kidney fibrosis in hypertensive rats: role of oxidative stress

Fibrosis of the glomerulus and the tubulointerstitium occurs in patients with hypertension. Studies have shown that renal oxidative stress appears in hypertensive kidney disease. The potential role of oxidative stress in renal fibrogenesis remains to be elucidated. Herein, we tested the hypothesis that oxidative stress contributes to the development of renal fibrosis during hypertension.Sprague-Dawley rats received angiotensin II (AngII; 9 microg/h s.c.) for 4 weeks with/without co-treatment of antioxidants, apocynin and tempol (120 mg/kg/day each, p.o.). Untreated rats served as controls. Appearance of renal oxidative stress and its effect on the expression of transforming growth factor (TGF)-beta(1), population of myofibroblasts, collagen synthesis/degradation and fibrosis in kidneys were examined. Chronic AngII infusion elevated systemic blood pressure (228 +/- 6 mm Hg), which was accompanied with extensive renal fibrosis and oxidative stress represented as upregulated NADPH oxidase and suppressed superoxide dismutase (SOD). Co-treatment with antioxidants led to: (1) markedly decreased renal NADPH oxidase; (2) significantly attenuated gene expression of TGF-beta(1), type I collagen, and tissue inhibitors of matrix metalloproteinase (TIMP)-I/-II in the kidney; (3) largely reduced population of myofibroblasts in both the cortex and medulla; (4) significantly reduced renal collagen volume, and (5) partially suppressed blood pressure (190 +/- 8 mm Hg). Thus, prolonged AngII administration promotes renal oxidative stress, which is associated with hypertensive renal disease. AngII induces renal oxidative stress by increasing NADPH oxidase and reducing SOD in the kidney, which, in turn, upregulates collagen synthesis, while suppressing collagen degradation, thereby promoting the development of fibrosis in kidneys of hypertensive rats.     

核因子κB受体活化因子及其配体在5/6肾切除大鼠肾脏中表达及缬沙坦对其影响

目的 探讨核因子κB受体活化因子(RANK)及其配体(RANKL)在5/6肾切除大鼠(STNx)残肾中表达的意义，以及血管紧张素受体拮抗剂(ARB)缬沙坦对其表达的影响。方法 制备5/6肾切除的SD大鼠动物模型， 分为未给药组、治疗组及假手术组。治疗组在5/6肾切除后即给予缬沙坦治疗，大鼠分别于第4、8、12 周杀检。第12 周时用ELISA方法检测大鼠血清中骨保护蛋白(OPG)及RANKL水平；显微镜观察肾脏病理变化；免疫组化方法及Western印迹方法分析RANK/RANKL/OPG蛋白表达；RT-PCR检测RANK/RANKL/OPG的mRNA表达。结果 (1)第12周时假手术组尿蛋白量为(6.1±0.6) mg/24 h；未给药组为(19.0±1.5) mg/24 h；治疗组为(13.4±1.2) mg/24 h，3 组间的差异有统计学意义(P均 < 0.01)。(2)第12周时未给药组及治疗组肾脏均有明显硬化，但治疗组硬化程度较未给药组轻。(3)未给药组RANK及RANKL蛋白及mRNA的表达均高于治疗组及假手术组，3 组间的差异有统计学意义(P均 < 0.01)。OPG蛋白及mRNA的表达在3 组间无显著性差异。(4)血清中OPG及RANKL含量在3 组间的差异亦无统计学意义。结论 在5/6肾切除大鼠残肾中表达上调的RANK和RANKL可能参与了肾小球硬化的发生发展。抑制RANK和RANKL的表达可能是缬沙坦延缓肾小球硬化的原因之一。