紫癜性肾炎的早期诊断

目的通过对尿分析及24h尿蛋白定量均正常的过敏性紫癜性肾炎(HSPN)患儿61例查尿微量蛋白及行肾活检并行病理分析,探讨早期肾活检的重要性。方法选择初治或复治,伴或不伴有关节及消化道症状,且尿分析及24h尿蛋白定量均正常的HSPN患儿,多次查尿微量蛋白,如尿微量蛋白正常或初检异常但1～2周内尿微量蛋白很快恢复正常者,不予肾活检,而持续尿微量蛋白异常或反复尿微量蛋白异常≥3次者行肾活检,观察病理变化;比较尿Alb的量、尿微量蛋白选择性与病理损害程度的关系,以及肾组织中免疫复合物IgA、IgG、IgM的沉积与病理损害程度之间的关系。采用SPSS11.0软件进行统计处理。结果所有尿分析及24h尿蛋白定量均正常,而持续尿微量蛋白异常或反复尿微量蛋白异常≥3次者,行肾活检,肾脏均有不同程度(Ⅱ～Ⅲ级)损害,其中Ⅱa26例(42.6%),Ⅱb10例(16.4%),Ⅲa21例(34.4%),Ⅲb4例(6.6%);且尿Alb的量、尿微量蛋白选择性与病理损害程度无明显相关性(Pa>0.05);随病理程度加重,肾组织中IgA IgG IgM共同沉积的比例增加(P<0.05)。结论对HSPN尿分析及24h尿蛋白定量均正常的患儿,要密切检测尿微量蛋白,尽早行肾活检,及时治疗,以改善预后。     

尼克酰胺腺嘌呤二核苷酸磷酸氧化酶介导血管紧张素II诱导的肾小球系膜细胞增殖

目的:探讨活性氧(ROS)在血管紧张素Ⅱ(AngⅡ)诱导的c-Jun氨基末端激酶(JNK)/活化蛋白(AP-1)信号通路活化及系膜细胞增殖中的作用并探讨其来源。方法:体外培养人肾小球系膜细胞,应用3H-胸腺嘧啶(3H-TdR)掺入法和细胞计数测定系膜细胞增殖;荧光探针2,7-二氯二氢荧光素乙酰乙酸(DCFDA)检测细胞内ROS的产生;化学发光法检测尼克酰胺腺嘌呤二核苷酸磷酸(NADPH)氧化酶活性;WesternBlot检测JNK活化。结果:AngⅡ呈时间依赖性和剂量依赖性促进肾小球系膜细胞ROS产生。AngⅡ刺激3min,系膜细胞内ROS产生明显增加,至60min达到高峰。AT1R血管紧张素Ⅱ-1型受体(AT1R)拮抗剂氯沙坦完全阻断了AngⅡ诱导的ROS产生。NADPH氧化酶抑制剂夹竹桃麻素和二联苯碘(DPI)几乎完全阻断AngⅡ诱导的ROS产生,而线粒体复合体Ⅰ抑制剂鱼藤酮、黄嘌呤氧化酶抑制剂别嘌醇、环氧化酶抑制剂吲哚美辛、脂氧化酶抑制剂去甲二氢化愈创木酸、细胞色素P450氧化酶抑制剂酮康唑以及一氧化氮合成酶抑制剂N-硝基-L-精氨酸甲酯(L-NAME)对AngⅡ诱导的ROS产生均无明显影响。AngⅡ显著刺激NADPH氧化酶活化及p47phox和p67phox膜转位。氯沙坦、乙酰半胱氨酸(NAC)、夹竹桃麻素和DPI阻断AngⅡ诱导的JNK/AP-1活化和系膜细胞增殖。结论:NADPH氧化酶来源的ROS调控AngⅡ诱导的JNK/AP-1信号通路活化及系膜细胞增殖。NADPH氧化酶抑制剂能显著抑制AngⅡ诱导的系膜细胞增殖,可能具有一定的治疗作用。     

核心蛋白聚糖对TGFβ1诱导的人肾小管上皮细胞产生胶原的影响

目的:探讨核心蛋白聚糖对转化生长因子β1(TGFβ1)诱导的人近端肾小管上皮细胞(HK-2)Ⅰ、Ⅲ型胶原表达的影响。方法:将体外培养的HK-2细胞分为:(1)阴性对照组;(2)10μg/LTGFβ1组;(3)TGFβ1(10μg/L) (10μg/L)核心蛋白聚糖组;(4)TGFβ1(10μg/L) (100μg/L)核心蛋白聚糖组。倒置显微镜下观察加入刺激因子48h后肾小管上皮细胞的细胞形态学改变;应用逆转录-聚合酶链反应(RT-PCR)观察不同浓度的核心蛋白聚糖对HK-2细胞Ⅰ、Ⅲ型胶原表达变化的影响。结果:加入刺激因子48h后,(1)组细胞形态与正常HK-2细胞形态基本一致,大部分仍为椭圆形;(2)组细胞形态发生明显的变化,大部分细胞由椭圆形拉长为长梭形;(3)和(4)组,梭形样细胞明显减少,尤其是(4)组梭形样细胞减少更为明显。(2)组HK-2细胞Ⅰ型胶原mRNA表达上升到(1)组的27.86倍,Ⅲ型胶原mRNA的表达上升到(1)组的21.83倍。(3)和(4)组与(2)组相比,Ⅰ型胶原mRNA的表达分别下降了36.39%、53.36%,Ⅲ型胶原mRNA的表达分别下降了26.35%、47.96%(P<0.05),但仍未下降到正常水平。结论:核心蛋白聚糖能抑制TGFβ1诱导的人近端肾小管上皮细胞Ⅰ、Ⅲ型胶原的表达,可能是核心蛋白聚糖抑制肾间质纤维化的原因之一。     

NADPH oxidase-derived reactive oxygen species involved in angiotensin Ⅱ-induced monocyte chemoattractant protein-1 expression in mesangial cells

Objective To investigate the origin of oxidative stress induced by angiotensin H (Ang Ⅱ ) in human mesangial cells and the role of reactive oxygen species ( ROS) in Ang Ⅱ -induced monocyte chemoattractant protein-1 (MCP-1) expression.Methods MCP-1 expression was determined by real time RT-PCR.ROS production was measured by DCFDA fluorescence.Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity was examined by lucigenin chemiluminescence.p47phox and p67phox translocation was assayed by Western blot.Twenty-four male mice were randomly divided into three groups; the control,the Ang Ⅱ infusion [ Ang Ⅱ 400 ng/(kg±min) ],and the apocynin treatment.Ang Ⅱ was infused by subcutaneously osmotic minipump for 14 days.Urinary albumin and 8-isoprostane excretion were measured by ELISA.Results In cultured human mesangial cells,Ang Ⅱ induced the MCP-1 expression in a dose-dependent manner with 3.56 fold increase as compared with the control.Ang Ⅱ increased intracellular ROS production as early as 3 min with the peak at 60 min and was in a time and dose-dependent.Incubation with different dosages of Ang Ⅱ ( 1μmol/L,10μmol/L,and 100μmol/L Ang Ⅱ ) for 60 min,ROS production increased at 1.82,2.92,and 4.08 folds respectively.Ang Ⅱ-induced ROS generation was sensitive to diphenyleneiodonium sulfate (DPI,10 μmol/L) and apocynin (500μmol/L) ,two structurally distinct NADPH oxidase inhibitors.In contrast,inhibitors of other oxidant- producing enzymes,including the mitochondrial complex I inhibitor rotenone,the xanthine oxidase inhibitor allopurinol,the cyclooxygenase inhibitor indomethacin,the lipoxygenase inhibitor nordihydroguiaretic acid,the cytochrome P450 oxygenase inhibitor ketoconazole and the nitric oxide synthase inhibitor G-nitro-L- arginine methyl ester were without an effect Ang Ⅱ -induced ROS generation was inhibited by the ATI antagonist losartan (10μmol/L) but not the AT2 antagonist PD123319 (10μmol/L).Ang Ⅱ treatment induced translocation of cytosolic of p47 and p67 to the membrane.The antioxidants almost abolished Ang Ⅱ -induced MCP-1 expression.Ang Ⅱ infusion increased urinary and p67 translocation by 2.69-,2.97-,and 2.67-fold,respectively.Conclusions NADPH oxidase-derived ROS is involved in Ang Ⅱ-induced MCP-1 expression.Inhibition of NADPH oxidase alleviates Ang Ⅱ -induced renal injury.