从人胚胎胰腺中分离获得巢蛋白表达阳性的细胞

目的 探讨从人胚胎胰腺组织分离巢蛋白（Nestin)阳性细胞并进行体外传代培养的方法。方法 取引产的16、18、20周人胚胎胰腺组织，分离胰岛样细胞簇（Ialet-like cell clusters,ICCs），进行体外培养。用免疫组织化学和逆转录-聚合酶链反应（RT-PCR）方法检测巢蛋白、胰十二指肠同源盒基因-1（Pancreatic and duodenal bomeobox gene-1,PDX-1/IPF-1)以及胰岛内分泌激素胰岛素和胰升糖素（Glucagon)的表达。结果 ICCs经体外培养可获得巢蛋白表达阳性细胞，这种细胞可进一步形成球状细胞簇，除有巢蛋白阳性细胞外，还有PDX-1，胰岛素和胰升糖素表达阳性的细胞。并且细胞可连续传代，结论 从人胚胎胰腺组织中可分离获得巢蛋白表达阳性细胞，这种细胞可在体外增殖并有向胰岛内分泌细胞分化的能力。     

白藜芦醇对TGF-β1诱导的足细胞凋亡及骨架分子损害的干预作用

目的:探讨白藜芦醇对肾足细胞凋亡和骨架蛋白异常的干预作用。方法:体外分化条件下培养小鼠足细胞10d,用转化生长因子-β1(transforming growth factor-beta,TGF-β1)诱导作为研究模型,白藜芦醇干预,肝细胞生长因子(hepatocyte growth factor hepatocyte,HGF)作为对照。流式细胞术检测足细胞线粒体膜电位以及Vimentin、Nestin等蛋白表达,采用western-blotting技术检测骨架蛋白α-actinin-4蛋白表达。用蛋白滤过试验检测单层足细胞的蛋白滤过功能。结果:TGF-β1可诱导足细胞线粒体膜电位显著降低,骨架蛋白Vimentin、α-actinin-4等表达水平显著下调,而Nestin表达显著增高。白藜芦醇干预可增高足细胞线粒体膜电位以及Vimentin、α-actinin-4等表达,对Nestin表达则差异无统计学意义;HGF对线粒体膜电位、Vimentin、α-actinin-4等差异无统计学意义,但可显著降低Nestin表达;白藜芦醇和HGF干预均可显著降低透过单层足细胞的蛋白滤过量。结论:白藜芦醇抑制TGF-β1诱导的足细胞骨架系统蛋白表达异常和细胞凋亡的作用,可能是其维持足细胞滤过屏障完整性的机制之一,HGF对足细胞损害的干预作用与白藜芦醇不同,机制尚不明确。     

神经干细胞移植治疗结肠去神经节小鼠

目的 观察神经干细胞在去神经节小鼠结肠壁内的存活分化,探讨神经干细胞移植治疗结肠无神经节细胞症的可行性.方法 0.5%苯扎氯铵(BAC)处理8周龄昆明小鼠结肠浆膜层选择性去除结肠肇神经节制作巨结肠模型,原代培养新生小鼠大脑皮质来源神经干细胞,Hoechsd3342标记传代纯化后神经干细胞.运用微量注射器将标记后的神经干细胞移植入模型鼠病变肠段,分别于术后1、2、3、4周行大体观察,苏木素-伊红(HE)染色,免疫组织荧光检测小鼠生物学特性和神经干细胞存活分化情况.结果 原代培养神经干细胞Nestin表达阳性,体外培养可分化为神经元和神经胶质细胞;BAC处理后,HE染色及免疫组织化学染色显示小鼠结肠肌间及黏膜下神经节消失;神经干细胞移植后各观测时间点可见荧光标记细胞,免疫组织荧光检测显示术后1周结肠壁存在巢蛋白(Nestin)表达阳性细胞,3周后可见神经元特异性烯醇化酶(NSE)及胶质纤维酸性蛋白(GFAP)表达阳性细胞,对照组未观察到阳性表达.结论 神经干细胞可以在去神经节小鼠结肠肇内存活并分化为神经元及胶质细胞,部分恢复肠道神经的调节作用.     

N-乙酰基-丝氨酰-天门冬酰-赖氨酰-脯氨酸对高糖诱导足细胞损伤的保护作用及机制

目的高糖可诱导足细胞损伤,促进糖尿病蛋白尿的产生及肾脏纤维化的进展。N-乙酰基-丝氨酰-天门冬酰-赖氨酰-脯氨酸(AcSDKP)是由血管紧张素转化酶水化的一种生理性四肽,可抑制肾脏纤维化。本文通过体外培养条件永生性小鼠足细胞,探讨AcSDKP对高糖诱导足细胞损伤的保护作用及可能机制。方法体外培养条件永生性小鼠足细胞,采用高糖(30 mmol/L)刺激48 h,同时予AcSDKP干预。分为正常对照组(常规低糖培养基培养)、高糖组、高糖+AcSDKP组。采用免疫荧光法检测各组细胞足细胞特异性标记物nephrin的表达改变,采用免疫印迹法检测各组足细胞纤连蛋白(fibronectin)、α-平滑肌肌动蛋白(α-SMA)的表达改变,采用免疫荧光检测各组足细胞骨架,采用流式细胞仪检测各组足细胞凋亡率。结果高糖可减少足细胞nephrin表达,AcSDKP处理后足细胞nephrin表达有所恢复。高糖组可促进足细胞间充质标记物fibronectin、α-SMA的表达升高,AcSDKP可抑制高糖刺激下足细胞fibronectin、α-SMA的表达。高糖可诱导足细胞骨架出现紊乱、重组,促进足细胞黏附性下降,诱导足细胞凋亡,AcSDKP可抑制足细胞骨架紊乱重组、改善足细胞黏附性、抑制足细胞凋亡。结论 AcSDKP可对高糖诱导的足细胞损伤发挥保护作用,其机制可能与逆转足细胞上皮-间充质转化,稳定细胞骨架、恢复足细胞黏附性及抑制足细胞凋亡有关。     

血管紧张素Ⅱ诱导足细胞c-Abl的表达改变

目的 探讨血管紧张素Ⅱ( AngⅡ)诱导下大鼠肾脏及条件永生性小鼠足细胞c-Abl的表达变化.方法 采用AngⅡ泵(400ng·kg-1·min-1)植入SD大鼠皮下的方法建立AngⅡ输注模型,24只大鼠成模后被随机分为AngⅡ输注2周组、AngⅡ输注4周组、AngⅡ输注+替米沙坦(ARB,3 mg·kg-1·min-1)干预2周组及4周组,同时设生理盐水输注组和健康对照组,每组6只.分别于成模后2周末、4周末处死大鼠取肾.电镜下观察肾脏足细胞超微结构的改变;免疫荧光法检测肾脏c-Abl表达;实时PCR及Western印迹检测c-Abl mRNA及蛋白水平的改变.对于体外培养条件永生性小鼠足细胞,免疫荧光法检测足细胞肾脏c-Abl的表达,实时PCR及Western印迹法检测足细胞在AngⅡ不同作用浓度(10-9 mol/L～10-6 mol/L)及不同作用时间点(0h、3h、6h、12 h、24 h)c-Abl mRNA和蛋白水平的变化.结果 (1)免疫荧光检测结果显示肾脏足细胞有c-Abl表达;实时PCR及Western印迹结果显示AngⅡ输注2周组和4周组大鼠肾脏c-Abl表达增加(P＜0.05),ARB干预组大鼠肾脏c-Abl表达较同期AngⅡ输注组均有降低(P＜0.05).(2)体外培养的条件永生性小鼠足细胞胞质及胞核有c-Abl表达.AngⅡ可诱导培养的小鼠足细胞c-Abl mRNA及蛋白表达增加(P＜0.05),且呈时间和剂量依赖性.结论 c-Abl在肾足细胞及体外培养足细胞均有表达,AngⅡ可诱导c-Abl表达上调.c-Abl可能参与了AngⅡ诱导的足细胞损伤.     

Heymann肾炎原位免疫复合物形成机理的分子学研究

通过受体相关蛋白ｃＤＮＡ探针，用组织原位杂交技术首次证明了ＲＡＰｍＲＮＡ在肾小球细胞中的表达。进一步通过ＲＡＰ融合蛋白抗血清的体外间接免疫荧光，免疫电镜和体内结合试验的直接免疫荧光和免疫电镜表明肾小球细胞中表达ＲＡＰ细胞为肾小球上皮足突细胞，循环抗体能与其结合形成免疫复合和的并刺激足突细胞内新抗原的不断合成，使得免疫复合物不断增大。从基因水平为Ｈｅｙｍａｎｎ肾炎原位免疫复合物形成机理提供了实验依据     

尿毒清颗粒对糖尿病大鼠足细胞损伤的保护作用研究

目的：探讨尿毒清颗粒对糖尿病大鼠足细胞损伤的保护作用。方法：将SD大鼠制备成STZ糖尿病模型,实验分3组：正常对照组、糖尿病未干预组、尿毒清颗粒治疗组（2.6g·kg-1·d-1灌胃）,于实验第4周、8周末检测血糖、血肌酐、尿肌酐及尿白蛋白排泄率,光镜、电镜下观察肾组织病理改变并计数足突宽度,免疫组化观察足细胞相关蛋白分子nepherin、podocin的表达,Real time-PCR检测肾皮质nepherin、podocin mRNA表达。结果：尿毒清颗粒可以改善糖尿病大鼠肌酐清除率,降低尿白蛋白排泄,改善肾脏病理,减轻足突融合,维持足细胞相关蛋白分子的分布与表达。结论：初步证实尿毒清颗粒能通过上调足细胞相关蛋白分子水平减轻足细胞损伤,对糖尿病大鼠足细胞损伤具有保护作用。     

Fascin蛋白在肾细胞癌中的表达及临床意义

目的观察Fascin蛋白在肾细胞癌中的表达情况,并探讨其表达与肿瘤生物学行为及临床病理指标的关系。方法用免疫组织化学方法检测109例肾细胞癌组织、20例肾脏良性肿瘤和20例正常肾脏组织中Fascin蛋白和Ki-67的表达,分析Fascin蛋白表达与不同临床病理指标及Ki-67表达之间的关系。结果109例肾细胞癌中有58例（53．2％）Fascin蛋白呈阳性表达,20例肾脏良性肿瘤和20例正常肾脏组织中的阳性表达例数分别为2例（10．0%）和0例（0%）,肾细胞癌中Fascin蛋白表达与肾脏良性肿瘤和正常肾脏组织中Fascin蛋白表达比较差异均有统计学意义（均P〈0．01）。肾细胞癌组织中Fascin蛋白表达与肿瘤组织学分级、临床分期、淋巴结转移以及Ki-67表达均呈正相关（均P〈0．01）;与肿瘤组织学分类无相关性（P〉0．05）。结论Fascin蛋白在肾细胞癌中表达上调且和肿瘤的恶性程度及侵袭行为有关。Fascin蛋白表达与病理分级和临床分期结合能够更好地判断肾细胞癌的预后,且其有可能成为肾细胞癌治疗的一个新靶点。     

巢蛋白在人真皮成纤维细胞中的表达

目的探讨巢蛋白(nestin)在人皮肤真皮组织成纤维细胞(adu lt hum an derm is fibrob lasts,HDF)中的表达。方法采用体外培养、免疫组织/细胞化学技术检测巢蛋白在6例成人皮肤真皮组织及体外培养3、5、7、10、12代龄皮肤真皮成纤维细胞中的表达,计数分析人皮肤真皮组织成纤维细胞中巢蛋白+成纤维细胞数量,权重法分析体外培养成纤维细胞各代间巢蛋白的表达差异。结果人皮肤真皮组织中,巢蛋白+成纤维细胞表达数量占成纤维细胞总数(9.5±3.0)%,其数量为(103.3±67.4)个/mm2。与人皮肤真皮组织巢蛋白+成纤维细胞的表达数量相比,体外培养的真皮成纤维细胞中巢蛋白+成纤维细胞数量明显升高,并出现代龄之间的差异(P<0.05),其中第7、10代细胞表达量高于第5、12代细胞,第3代细胞最少(P<0.05)。结论在人皮肤真皮组织成纤维细胞中存在着巢蛋白+成纤维细胞。体外培养条件下,人皮肤真皮巢蛋白+成纤维细胞数量增加,提示体外培养作为刺激因子可能使成纤维细胞反分化为其前体细胞,作为干细胞标志物的巢蛋白有可能成为用于成纤维前体细胞鉴定的标志物之一。     

大鼠脊髓源神经干细胞胶质细胞源性神经营养因子基因转染实验研究

目的　构建表达外源性胶质细胞源性神经营养因子(GDNF)的脊髓源基因工程神经干细胞。方法　体外分离纯化,扩增大鼠脊髓源神经干细胞,培养、诱导分化结果采用Nestin、NF 2 0 0、胶质纤维酸性蛋白(GFAP)免疫组织化学鉴定;用自行构建的大鼠胶质细胞源性神经营养因子真核表达质粒转染神经干细胞,用荧光检测及GDNF免疫组织化学染色予以证实,转基因GDNF表达采用酶联免疫吸附试验(ELISA)法定量分析。结果　体外纯化获得大量脊髓源神经干细胞,在血清诱导下能分化为神经元和神经胶质细胞;转基因神经干细胞能稳定表达GDNF ,在随后3周内,转基因神经球能持续表达外源性GDNF蛋白,表达量稳定在(93 .0±6.5 )ng/L左右。结论　胚胎脊髓源神经干细胞体外培养能保持干细胞生物学特点,转染GDNF后神经干细胞能稳定表达外源GDNF蛋白,为后续转基因治疗中枢神经系统疾病研究奠定了基础     

Differential expression of the intermediate filament protein nestin during renal development and its localization in adult podocytes

Nestin, an intermediate filament protein, is widely used as stem cell marker. Nestin has been shown to interact with other cytoskeleton proteins, suggesting a role in regulating cellular cytoskeletal structure. These studies examined renal nestin localization and developmental expression in mice. In developing kidney, anti-nestin antibody revealed strong immunoreactivity in vascular cleft of the S-shaped body and vascular tuft of capillary loop-stage glomerulus. The nestin-positive structures also were labeled by endothelial cell markers FLK1 and CD31 in immature glomeruli. Nestin was not detected in epithelial cells of immature glomeruli. In contrast, in mature glomerular, nestin immunoreactivity was observed only outside laminin-positive glomerular basement membrane, and co-localized with nephrin, consistent with podocyte nestin expression. In adult kidney, podocytes were the only cells that exhibited persistent nestin expression. Nestin was not detected in ureteric bud and its derivatives throughout renal development. Cell lineage studies, using a nestin promoter-driven Cre mouse and a ROSA26 reporter mouse, showed a strong beta-galactosidase activity in intermediate mesoderm in an embryonic day 10 embryo and all of the structures except those that were derived from ureteric bud in embryonic kidney through adult kidney. These studies show that nestin is expressed in progenitors of glomerular endothelial cells and renal progenitors that are derived from metanephric mesenchyme. In the adult kidney, nestin expression is restricted to differentiated podocytes, suggesting that nestin could play an important role in maintaining the structural integrity of the podocytes.     

Nestin is a novel marker for renal tubulointerstitial injury in immunoglobulin A nephropathy

Aim: Nestin, an intermediate filament originally identified as a marker of neural progenitor cells, is transiently expressed in endothelial cells and tubuloepithelial cells during kidney development. However, in adult kidneys, podocytes are the only cells that express nestin. In this study, we examined tubulointerstitial nestin expression in human glomerulonephritis. Methods: Renal biopsy specimens obtained from 41 adult patients with immunoglobulin (Ig)A nephropathy were studied. Nestin expression was determined by immunohistochemical staining and estimated by digital image analysis. To identify the phenotype of nestin‐positive cells, a double immunofluorescent study was performed for nestin and CD34 (a marker for endothelial cells) or α‐smooth muscle actin (α‐SMA, a marker for myofibroblasts). Results: In normal kidney, nestin expression was restricted to the podocytes and was not detected in tubular cells and tubulointerstitial cells. In contrast, increased nestin expression was observed at tubulointerstitial areas of IgA nephropathy. The degree of tubulointerstitial nestin expression was positively correlated with tubulointerstitial fibrosis (r = 0.546, P < 0.001). The double immunofluorescent study showed that most nestin‐positive cells in the interstitium were co‐stained with CD34 or α‐SMA, suggesting that peritubular endothelial cells and tubulointerstitial myofibroblasts express nestin during the progression of tubulointerstitial injury. In addition, strong nestin expression was associated with deterioration of renal function. Conclusion: Nestin expression is associated with tubulointerstitial injury and predicts renal prognosis in IgA nephropathy. Nestin could be a new marker for peritubular endothelial cell injury and tubulointerstitial fibrosis.     

Nestin expression in the kidney with an obstructed ureter

Nestin is an intermediate filament protein originally identified in neuroepithelial stem cells. This cytoskeletal-associated protein is also expressed in some non-neuronal organs including renal tubular cells and glomerular endothelial cells during kidney development. Little is known, however, about nestin expression in the kidney during injury. In this study, we find nestin expression induced in renal tubular and interstitial myofibroblasts in the adult rat kidney following unilateral ureteral obstruction. The degree of nestin expression was well correlated with the degree of tubulointerstitial fibrosis. Immunohistochemical identification of specific nephron segments showed that nestin was primarily expressed by proximal tubules, partially by distal tubules and thick ascending limbs of Henle but not by collecting ducts. The nestin-positive tubular cells also expressed vimentin and heat-shock protein 47 (HSP47) suggesting these cells reverted to a mesenchymal phenotype. Not all vimentin- or HSP-expressing cells expressed nestin; however, suggesting that nestin is distinct from these conventional mesenchymal markers. Nestin expression was also found associated with phenotypical changes in cultured renal cells induced by hypoxia or transforming growth factor-beta. Nestin expression was located in hypoxic regions of the kidney with an obstructed ureter. Our results indicate that nestin could be a novel marker for tubulointerstitial injury.     

Neural stem cell markers, nestin and musashi proteins, in the progression of human glioma: correlation of nestin with prognosis of patient survival

BACKGROUND: The IF protein nestin and the RNA-binding protein musashi are expressed by neural progenitor cells during CNS development. Their expression in glial tumors was evaluated by immunohistochemistry, and the histopathological scores correlated with levels of cysteine cathepsins that are known prognostic markers in several tumors. METHODS: The levels of nestin, musashi, and cathepsins B and L were assessed by immunohistochemical analysis of biopsies from 87 patients with primary CNS tumors. To confirm the immunohistochemical data, nestin expression was analyzed by real-time PCR in 12 brain tumor biopsies. The exact location of nestin-positive cells was determined by mapping the distribution of nestin in a highly invasive human glioma xenograft model. RESULTS: Immunostaining revealed nestin to be expressed in 95.8% and musashi in 80% of the patient biopsies. The total IHC score for nestin was significantly higher in high- than in low-grade tumors (P < .0001). No difference was observed for musashi (P = .11). Real-time PCR of nestin expression confirmed the immunohistochemical data. Nestin expression was shown to be a strong prognostic marker for decreased overall survival (P = .0001), whereas musashi expression has no prognostic significance. Moreover, nestin was shown by Cox regression analysis to be a stronger prognostic marker than cathepsins B and L. IHC staining of nestin in a xenograft model showed that its expression is localized mainly in the invasive tumor cells at the tumor periphery. CONCLUSIONS: Nestin is shown to be a strong prognostic marker for glioma malignancy. The presented data links the invasive glioma cells to CNS precursor cells, indicating that the most malignant cells in the gliomas may well be closely related to the glioma stem cells.     

Characterization and isolation of promoter-defined nestin-positive cells from the human fetal pancreas

Studies using adult human islets and mouse embryonic stem cells have suggested that the neurepithelial precursor cell marker nestin also identifies and can be used to purify beta-cell precursors. To determine whether nestin can be used to identify beta-cell progenitors in the developing human pancreas, we characterized nestin expression from 12 to 24 gestational weeks, purified nestin+ cells using an enhancer/promoter-driven selection plasmid, and determined whether nestin+ cells can differentiate into beta-cells. Nestin was visualized in the platelet endothelial cell adhesion molecule and alpha smooth muscle actin-positive blood vessels and colocalized with vimentin in the interstitium. Nestin was not observed in pan cytokeratin (pCK)-positive ductal epithelium or insulin cells. Purified nestin+ cells also coexpressed vimentin and lacked pCK immunoreactivity. Purified adult and fetal pancreatic fibroblasts also expressed nestin. The nestin enhancer/promoter used in the selection plasmid was sufficient to drive reporter gene expression, green fluorescent protein, in human fetal pancreatic tissue. Exposure of selected nestin+ cells to nicotinamide, hepatocyte growth factor/scatter factor, betacellulin, activin A, or exendin-4 failed to induce pancreatic and duodenal homeobox gene-1 or insulin message as determined by RT-PCR. Transplantation of nestin+ cells and fetal pancreatic fibroblasts into athymic mice also failed to result in the development of beta-cells, whereas nestin- fetal pancreatic epithelial cells gave rise to functional insulin-secreting beta-cells. We conclude that nestin is not a specific marker of beta-cell precursors in the developing human pancreas.     

Nestin expression in central nervous system germ cell tumors

Central nervous system (CNS) germ cell tumors constitute a unique class of rare tumors that mainly affect children and adolescents. These tumors are believed to originate from displaced primordial germ cells. Recently, results of treatment of germ cell tumors have improved with use of radiotherapy and combination chemotherapy. However, some tumors have proven refractory to intensive treatment with surgery, radiation, and combination chemotherapy. Nestin is an intermediate filament protein expressed in undifferentiated cells during CNS development and in CNS tumors and is used as a marker of immature elements of tumors, including brain tumor stem cells. In this study, we examined for the first time nestin expression in 19 CNS germ cell tumors (nine pure germinomas, five germinomas with syncytiotrophoblastic giant cells, one yolk sac tumor, one choriocarcinoma, one embryonal carcinoma, and two mature teratomas). Nestin was expressed in 14 cases but was not expressed in three pure germinomas and two mature teratomas. Clinically, nestin-negative tumors did not exhibit dissemination, while all tumors that exhibited dissemination also strongly expressed nestin protein. These findings suggest that the detection of nestin expression could be useful in the management of CNS germ cell tumors, as an auxiliary predictor of dissemination and/or progression.     

儿童原发性肾病综合征中血管生成素样蛋白3的表达

目的 研究血管生成素样蛋白3 (angiopoietin-like 3 protein，ANGPTL3)在儿童原发性肾病综合征(PNS)患者肾组织中表达分布及其参与蛋白尿发生的机制。方法 ANGPTL3分别与足细胞核标记抗原(WT1)、基底膜标记抗原类肝素硫酸蛋白多糖perlecan进行双标记法免疫荧光染色。应用免疫组化的方法检测ANGPTL3和perlecan在不同病理类型的69例PNS及血尿患儿，包括微小病变(MCD)31例、膜性肾病(MN)6例、局灶节段硬化性肾小球肾炎(FSGS)6例、IgA肾病16例、薄基底膜肾病(TBMN)10例以及2例正常对照肾组织中表达，并以IMS彩色图像分析系统量化为免疫组化指数。在MCD病例中将尿蛋白肌酐比值分别与肾组织中ANGPTL3和perlecan肾小球内染色强度及电镜下平均足突宽度(FWP)进行相关分析。对不同病理诊断时间(发病至肾穿刺)分组患儿肾小球ANGPTL3和perlecan的表达进行比较。结果 (1)ANGPTL3在正常肾组织呈现微弱的沉积，而在不同病理类型的肾病综合征患儿的肾组织的肾小球和肾小管存在不同程度的表达。肾小球内ANGPTL3表达量在MCD(7.49±1.96)、MN(6.27±0.98)中显著高于正常对照(0.02±0.001)、TBMN(0.02±0.001)及FSGS(3.14±0.49)(均P < 0.05)。在IgA肾病(系膜增生型)中，蛋白尿组肾小球中ANGPTL3表达量显著高于单纯血尿组(1.90±0.81比0.03±0.01， P < 0.05)。(2) 在MCD肾组织中，WT1及perlecan荧光双标记染色显示， ANGPTL3在足细胞胞浆及沿肾小球血管袢表达。(3) ANGPTL3在肾小球表达量分别与尿蛋白肌酐比值及电镜下平均足突宽度正相关(r为0.86、0.84，P均<0.05)，并与perlecan在肾小球内表达量负相关(r为-0.83，P < 0.05)。(4)不同发病年限的MCD患儿肾组织中肾小球ANGPTL3及perlecan的表达无显著性差异。结论 在不同程度的蛋白尿及不同足突融合程度的肾组织中存在ANGPTL3的表达差异。在MCD中，ANGPTL3主要在足细胞胞浆表达，肾小球中ANGPTL3的表达与蛋白尿程度及足细胞融合程度呈正相关。     

巢蛋白在足突广泛融合的肾小球中表达下调及与蛋白尿程度的相关性

目的 观察中间丝蛋白类的巢蛋白（nestin）在足突广泛融合的肾小球中的表达及其与足突病变动态过程和蛋白尿产生的关系。 方法 免疫组化法检测nestin在人正常肾组织及微小病变肾组织中的表达。构建氨基核苷嘌呤霉素肾病大鼠模型，应用免疫组化、荧光实时定量PCR、Western印迹法检测注射嘌呤霉素后第1、4、10、20天大鼠肾小球中nestin的分布与表达；电镜观察肾脏足细胞改变，测定尿蛋白量（24 h）。分析nestin的变化与蛋白尿的相关性。 结果 免疫组化显示nestin在人类微小病变肾小球中的表达较正常组织显著下调（0.93±0.08 比 1.65±0.12，P < 0.05）。在嘌呤霉素损伤足细胞早期，肾小球nestin的表达曾有一过性增加（mRNA和蛋白水平分别为对照组的1.23倍和1.48倍，P < 0.05），随后持续下降。nestin的mRNA水平在嘌呤霉素注射后第4天时降至对照组的35.8%；第10天时为对照组的12.1%（均P < 0.01）；病变好转后开始上升，恢复为对照组的65.8%（P < 0.05）。Western印迹检测nestin蛋白改变也有类似的趋势，嘌呤霉素注射后第4 天，nestin蛋白水平有所下降，为对照组的77.0%（P < 0.05）；至大量蛋白尿的第10天，nestin蛋白水平仅为对照组的58.0%（P < 0.05）；而随着病变的恢复，嘌呤霉素注射后第20天时nestin蛋白量恢复为对照的83.4%。Pearson相关分析结果显示，注射嘌呤霉素后nestin mRNA（r = －0.667，P < 0.05）及蛋白（r = －0.621，P < 0.05）表达与尿蛋白量(24 h)均呈负相关。 结论 在以足突广泛融合为特征的肾脏病变中，肾小球中间丝蛋白nestin表达显著减少，并与蛋白尿程度呈负相关，提示nestin可能参与了足细胞形态和功能的维持。