尿酸钠结晶影响肾小管上皮细胞的紧密连接

背景：目前研究来看,尿酸性结石与紧密连接蛋白及肾间质纤维化的关系仍未明确。目的：观察尿酸钠结晶对肾小管上皮细胞紧密连接的影响。方法：配制单钠尿酸钠晶体。将正常大鼠肾小管上皮细胞随机分为对照组和尿酸钠结晶组,分别用无血清培养基和尿酸钠结晶进行培养。免疫荧光和RT-PCR方法检测24,48,72h紧密连接蛋白的表达。结果与结论：与对照组比较,尿酸钠结晶于不同时相刺激NRK-52E细胞后,紧密连接蛋白和mRNA表达下降（P〈0.05）,72h时下降显著（P〈0.01）,蛋白表达出现重新分布现象。说明尿酸钠结晶可破坏肾小管上皮细胞紧密连接蛋白的结构、功能及导致分布异常。     

转化生长因子β1抑制人肾小管上皮细胞的增殖

背景：慢性肾衰竭进展过程中的一个重要病理改变是炎症和纤维化,主要包括肾小球和肾小管的炎症和纤维化。目前大多数研究主要集中于肾小球,对于肾小管病变的研究相对较少。但实际上部分疾病的肾小管病变出现在肾小球病变之前,其对于疾病预后更具有指导意义。目的：观察转化生长因子β1对人类肾小管上皮细胞HK-2增殖的影响,探索转化生长因子β1在肾小管炎症和纤维化方面的作用。方法：将传代培养的HK-2细胞分成空白对照组和转化生长因子β1作用组,分别使用DMEM／F12培养液,以及含转化生长因子β1（2,5,10#g／L）的DMEM／F12培养液培养,在倒置显微镜下观察各组细胞形态的改变,并使用MTT法检测细胞增殖情况。结果与结论：转化生长因子β1能显著抑制人。肾小管上皮细胞的增殖,并促使细胞向纤维样改变,与空白对照组相比差异有显著性意义（P〈0．05）,其抑制增殖作用并不随转化生长因子β1质量浓度的增大而显著增强,作用时间可持续至72h。结果可见转化生长因子β1能够抑制人肾小管上皮细胞的增殖,并具有促进肾间质纤维化的作用。     

糖尿病肾病肾小管上皮细胞上皮-间充质转化的机制研究进展

糖尿病肾病(DN)发生肾纤维化是导致终末期肾脏病(ESRD)的关键原因。肾小管上皮细胞(RTEC)上皮-间充质转化(EMT)参与了DN肾组织纤维化的发生和发展。目前DN中EMT的发病机制仍不完全清楚,尚需进一步探索。本文将对DN中参与RTEC的EMT的多重机制做一综述,以期为通过抑制小管上皮细胞(TEC)的EMT治疗DN提供思路。     

肾小管上皮细胞-间充质转化在糖尿病肾病中作用的研究进展

糖尿病肾病(DN)是糖尿病重要的微血管并发症。近年多项研究表明,肾小管上皮细胞(TEC)的上皮细胞-间充质转化(EMT)在DN的发病机制中起重要作用,但EMT在肾纤维化中的作用以及该作用是否存在于人类体内仍是正在讨论的问题,该文就TEC的EMT参与DN的分子机制以及目前对EMT参与DN肾纤维化的研究进展进行综述。     

肾康注射液对肾小管上皮细胞LLC-PK_1分泌型胶原的影响

目的 :探讨肾康注射液对肾小管上皮细胞 L L C PK1 分泌 型胶原 (Co )的影响。方法 :用细胞酶联免疫吸附法 (EL ISA ) ,以单味大黄注射液为实验对照组 ,检测肾康注射液对肾小管上皮细胞 L L C PK1 分泌Co 含量的影响。结果 :肾康注射液可以显著抑制肾小管上皮细胞 L L C PK1 分泌 Co 的含量 ,并呈剂量依赖关系 ;肾康注射液作用明显优于同等含量的单味大黄注射液。结论 :肾康注射液抑制肾小管上皮细胞 L L CPK1 分泌 Co 含量 ,是该中药复方延缓慢性肾功能衰竭进展的机制之一。     

Gli1对TGF-β1诱导的肾小管上皮细胞间质转分化和胶原合成的影响

目的 探讨锌指转录因子1(Gli1)对转化生长因子-β1(TGF-β1)诱导的肾小管上皮细胞间质转分化和胶原合成的影响.方法 培养肾小管上皮细胞NRK-52E,分为Control、TGF-β1(TGF-β1诱导)、sh-NC+TGF-β1(转染阴性对照shRNA,TGF-β1处理)和sh-Gli1+TGF-β1(转染G...     

转化生长因子β1对大鼠肾小管上皮细胞中基质细胞衍生因子1表达的影响

目的:已知转化生长因子β1与肾脏组织纤维化形成有密切关系.拟进一步探讨转化生长因子β1对大鼠近端肾小管上皮细胞(NRK52E)中基质细胞衍生因子1表达的影响.方法:实验于2006-03/2007-05在四川大学生物治疗国家重点实验室神经分子生物实验室完成.①实验材料:大鼠近端肾小管上皮细胞株NRK52E,由澳大利亚Monash医学中心肾内科实验室提供;转化生长因子β 1由cytolab公司提供.②实验分组:将大鼠近端肾小管上皮细胞分为正常对照组:无转化生长因子β1干预;实验组:又分为在同一转化生长因子β1浓度(2μ g/L)下,培养6,12,24 h;在不同的转化生长因子β1浓度(2,5,10 μ g/L)下,培养24 h.③利用免疫细胞化学技术对同一转化生长因子β1浓度(2 μ g/L)干预不同时间后的大鼠近端肾小管上皮细胞中基质细胞衍生因子1的蛋白表达进行半定量分析,选择出最佳的作用时间点;通过反转录-聚合酶链反应、Western-Blotting以检测大鼠近端肾小管上皮细胞中基质细胞衍生因子1在不同转化生长冈子β1浓度干预下培养24 h后的mRNA、蛋白表达变化情况.结果:①培养12,24h时,大鼠近端肾小管上皮细胞中基质细胞衍生因子1的蛋白表达比0h增高(P＜0.05);24h时表达略高于12h(P＞0.05).提示,基质细胞衍生因子1的表达到达一_甲台期,24h为最佳的作用时间点.②从mRNA水平和蛋白水平均证实,2 μ g/L转化生长因子β 1干预24 h后的大鼠近端肾小管上皮细胞中基质细胞衍生因子1的表达高于正常对照组(P＜0.05):随着转化生长因子β1的浓度增大,表达呈下降趋势,10 μ g/L时表达低于2 μ g/L时的表达(P＜0.05).结论:基质细胞衍生因子1在正常的大鼠近端肾小管上皮细胞中呈低表达状态,对转化生长因子β1的干预表现出一定的时间、剂量依赖性,基质细胞衍生因子1可能参与了肾问质纤维化的发生、发展.     

骨髓间充质干细胞对缺血/再灌注损伤肾小管上皮细胞Bcl-2 Fas/FasL表达的影响

目的 探讨外源性骨髓间充质干细胞(MSCs)移植对缺血/再灌注损伤(I/R)后肾小管上皮细胞凋亡以及Bcl-2、Fas和FasL表达的影响.方法 将雄性SD大鼠MSCs用DAPI标记后注入受体雌性SD大鼠体内.30只受体大鼠随机分为三组(n=10):假手术对照组(C组)、MSCs I/R组(M组)、DMEM-F12 I/R组(D组).7 d后观察肾功能、肾脏病理改变,采用原位末端标记法检测细胞凋亡指数,免疫组化法检测Bcl-2、Fas和FasL的表达,并观察DAPI标记的MSCs在受体大鼠肾脏的分布情况.结果 M组在肾功能、肾脏病理改变上,均明显好于D组;M组Bcl-2蛋白表达均高于D组,而Fas、FasL蛋白表达和凋亡指数均低于D组.I/R后7 d内未发现MSCs定位于肾组织中.结论 外源性MSCs可以减少I/R损伤后肾小管上皮细胞凋亡,促进Bcl-2和抑制Fas、FasL表达,从而有利于肾小管损伤的早期恢复.     

高脂血症对OLETF大鼠肾小管上皮细胞尿酸盐阴离子交换器表达的影响

目的:探讨自发代谢综合征及2型糖尿病动物模型(OLETF大鼠)在高脂血症阶段肾小管上皮细胞尿酸盐阴离子交换器(URAT1)的表达.方法:选择雄性4周龄OLETF大鼠10只为OLETF组,同系4周龄LETO大鼠(非糖尿病)10只为LETO组,基础饮食至11周龄,记录7周龄和11周龄大鼠体重、体长,检测甘油三酯(TG)、总胆固醇(TC)、尿酸(UA)、肌酐、尿素氮、高密度脂蛋白,采用荧光定量RT-PCR方法检测URAT1在肾皮质中的表达量.结果:大鼠11周龄时,OLETF组TG、TC较LETO组显著增高,均P＜0.05;UA较LETO组升高,但P＞0.05;URAT1 mRNA的表达水平为2.17,较LETO组(1.00)明显升高,P＜0.05.结论:OLETF大鼠在高脂血症阶段,随着尿酸的升高,URAT1 mRNA的表迭明显升高.可能通过上调URAT1的表达,来调节体内尿酸的排泄.脂代谢紊乱和高尿酸血症可能通过该纽带密切相关联.     

草酸钙晶体对大鼠肾小管上皮细胞骨桥蛋白表达的影响

目的探讨一水草酸钙(calcium oxalate monohydrate,COM)晶体对大鼠肾小管上皮细胞中骨桥蛋白(osteopontin,OPN)表达的影响。方法选用SD大鼠的肾皮质原代培养出肾小管上皮细胞并制成爬片,将爬片的肾小管上皮细胞随机分为A、B、C、D、E5组。A组不加COM(11例);B组1 mmol/L浓度COM(17例);C组3 mmol/L浓度COM(18例);D组5 mmol/L浓度COM(18例);E组10 mmol/L浓度COM(17例)。采用免疫组织化学法(SABC)检测各组肾小管上皮细胞中OPN的表达,并进行阳性细胞计数和各组间比较。结果 OPN的表达主要定位于细胞质,呈棕褐色。各组OPN阳性表达率:A组54.5%;B组64.7%;C组77.8%;D组88.9%;E组76.5%。随着COM浓度增加,OPN表达逐渐增强,到5 mmol/L浓度COM时OPN表达最强(P0.01),而10 mmol/L浓度COM时OPN表达反而下降,接近3 mmol/L浓度COM水平(P0.05)。结论大鼠肾小管上皮细胞受COM刺激后OPN表达增强,但高浓度COM使OPN表达减弱,提示高浓度COM通过损伤肾小管上皮细胞使OPN表达下降,进而形成结石。     

Protein kinase C mediates cisplatin-induced loss of adherens junctions followed by apoptosis of renal proximal tubular epithelial cells

Cisplatin is a commonly used antitumor agent in the treatment of various human cancers, with nephrotoxicity as a major side effect. Cisplatin causes the loss of cell-cell contacts of renal proximal tubular epithelial cells prior to the onset of apoptosis. We studied the involvement of protein kinase C in these events in the renal epithelial cell line LLC-PK1. Cisplatin caused apoptosis in LLC-PK1 cells, which was directly related to the activation of caspase-3 and DNA fragmentation. Apoptosis was almost completely inhibited by the protein kinase C inhibitors bisindolylmaleimide (Bis) I and Go6983 [2-[1-(3-dimethylaminopropyl)-5-methoxyindol-3-yl]-3-(1H-indol-3-yl) maleimide], but not by Go6976 [12-(2-cyanoethyl)-6,7,12,13-tetrahydro-13-methyl-5-oxo-5H-indolo(2,3-a)pyrrolo(3,4-c)-carbazole]. Also, in primary cultured rat renal proximal tubular cells, inhibition of protein kinase C (PKC) inhibited apoptosis. Cisplatin also caused the early loss of cell-cell adhesions, which was associated with the altered localization of the adherens junction-associated protein beta-catenin in association with PKC-mediated phosphorylation of the actincapping protein adducin. These events preceded and were independent of caspase activation. beta-Catenin did not dissociate from E-cadherin. Cisplatin-induced loss of cell-cell contacts was associated with the increased formation of F-actin stress fibers, which was inhibited by Bis I and Go6983 as well as dominant-negative PKC-epsilon. Also, the loss of cell-cell adhesions by cisplatin was prevented by Bis I and Go6983. Activation of protein kinase C with phorbol esters promoted cisplatin-induced loss of cell-cell adhesions as well as apoptosis. In conclusion, the combined data fit a model whereby protein kinase C mediates the cisplatin-induced loss of cellular interactions. Such a loss of these interactions has a role in the onset of apoptosis.     

Binding of IgG and complement protein by monosodium urate monohydrate and other crystals.

IgG adsorbed to negatively charged crystals of monosodium urate monohydrate was restricted to cationic species of immunoglobulin. Similar binding of smaller amounts of IgG was observed with crystals other than monosodium urate monohydrate. Heated monosodium urate monohydrate and amorphous sodium urate adsorbed greater amounts of IgG and other proteins. Complement activation as measured by electrophoretic conversion of C3, was not related to the amount of IgG adsorbed by the crystals studied. C1q was also adsorbed to some degree by all crystals studied but did not correlate with complement activation.     

Familial hypouricaemia due to renal tubular defect of urate transport.

A 28-year-old man was found to have hypouricaemia (plasma uric acid, 0.40 to 1.25 mg/100 ml). The 24-hour urinary urate excretion on a low purine diet was 690 mg, a value higher than the mean value of 419 mg for gouty Japanese patients. Urate clearance was 88.5 ml/min--approximately the same as the endogeneous creatinine clearance. The ratio of urate clearance to creatinine clearance was scarcely altered by pyrazinamide, but diminished by probenecid (from 69.2% to 52.4%). No other renal tubular abnormalities were detected. The findings in this subject may be accounted for by a nearly complete tubular defect in reabsorptive transport mechanisms of urate. A survey of his family revealed at least three similarly affected persons, who were all from consanguineous marriages. The hypouricaemia was transmitted as an autosomal trait.     

Retrograde transport of Shiga toxin 1 in human renal tubular epithelial cells

To displays its cytotoxicity by initiating RNA cleavage, Stx1 is required to be transported from endosomes to the endoplasmic reticulum, where the translocation of the A-subunit to the cytosol occurs. In the case of established cell lines, it is reported that a large proportion of the internalized Stx is transported to lysosomes for degradation and only a fraction of the toxin molecules can reach to the cytosol. By using primary culture cells, however, we observed that Stx1 is effectively delivered to the cytosol in normal human renal tubular epithelial cells. Investigation of retrograde transport mechanism of Stx should provide insights into the analysis of Stx-mediated cell damage and lead to improvements in therapeutic approaches for diseases caused by Stx.