钙调神经蛋白在抗肾小球基底膜病肾小球内的表达增强

 目的 观察抗肾小球基底膜（GBM）病患者肾小球足细胞钙调神经蛋白（CaN）的表达,了解其与临床病理特点及肾脏长期存活的关系。方法 选取临床病理资料完整的抗GBM病患者29例,对照为8例肾小球轻微病变患者。收集患者临床资料,免疫组化方法检测CaN A亚基α亚单位（CnAα）在肾小球的表达,免疫荧光染色观察足细胞骨架蛋白synaptopodin表达,分析CnAα与临床病理表现及预后的关系。结果 29例抗GBM病患者肾小球内均有不同程度的CnAα表达阳性,阳性区域占肾小球面积百分比显著高于轻微病变者（21.63%±14.27% vs 2.21%±1.41%,p<0.01）,同时伴有synaptopodin缺失。CnAα的表达量与抗GBM抗体峰值、血肌酐水平、血红蛋白水平、新月体比例及细胞/细胞纤维新月体比例呈现显著相关性,并与预后相关。结论 首次观察到抗GBM病患者肾小球内CnAα表达增强,表达量与疾病活动、严重程度及预后相关,提示足细胞可能参与抗GBM病新月体形成,其作用机制仍有待进一步研究。     

一氧化氮在肾缺血再灌注肾小球损伤中的作用

目的:探讨一氧化氮(NO)对肾缺血再灌注（ischemia-reperfusion injury，I-RI）时大鼠肾小球超微结构及负电荷位点的影响。 方法:SD大鼠15只，建立肾缺血再灌注模型，动物随机分为5组：（1）假手术（sham）组（n=6）；（2）I-RI组（n=6），缺血前20 min舌静脉注入生理盐水0.3 mL；（3）SNP+I-RI组（n=6），缺血前20 min舌静脉注入2.5 μg/kg硝普钠（SNP）；（4）AG+I-RI组（n=6），缺血前20 min舌静脉注入10 mg/kg氨基胍（AG）；（5）L-NNA+I-RI组（n=6），缺血前20 min舌静脉注入10 mg/kg L-硝基精氨酸（L-NNA）。以聚乙烯亚胺（PEI）为阳离子探针标记肾小球滤过膜负电荷位点，透射电镜观察肾I-RI对大鼠肾小球超微结构及负电荷位点的影响。 结果:(1) sham组电镜下见肾小球结构正常，肾小球基底膜（GBM）外透明层负电荷位点（AS）清晰，呈连续的规则点线状排列［（19.3±1.7）个/1 000 nm］。I-RI组肾小球足细胞足突有明显的融合现象；GBM外透明层AS排列稀疏［（16.6±1.0）个/1 000 nm，P<0.05］，PEI颗粒小。（2）与I-RI组相比，给予SNP使肾I-RI大鼠肾小球滤过膜上皮细胞足突融合现象加重，肾小球GBM的AS［（11.7±3.2）个/1 000 nm］显著少于假手术组（P<0.05），且PEI颗粒的电子致密度也明显低于假手术组；而AG的应用使I-RI大鼠肾小球滤过膜损伤减轻，可见清晰的足突间隙；L-NNA+I-RI组大鼠肾小球上皮细胞足突融合也明显加重，但和I-RI组相比，L-NNA+I-RI组大鼠GBM的AS数量［（14.7±0.9）个/1 000 nm］无显著差异（P>0.05）。 结论:肾I-RI时出现肾小球上皮细胞足突融合、肾小球滤过膜的负电荷位点减少等病理性损伤，NO可加重这些损伤；肾I-RI时肾小球滤过膜超微结构的损伤与NO的生成及其作用有关。     

肾小球滤过屏障超微结构改变与Alport综合征蛋白尿的关系

 目的:探讨肾小球滤过屏障超微结构改变与Alport综合征（AS）蛋白尿发生的关系。方法:AS患者35例,男24例,女11例,肾活检的年龄为1.17~24岁。根据尿蛋白结果将患者分为2组：无/间歇性蛋白尿组（13例）和持续性蛋白尿组（22例）。测量AS肾小球基底膜（GBM）变薄、增厚和致密层撕裂分层的长度,计算其各占GBM总长度的百分比;根据平均足突宽度（FPW）= π／4×（∑基底膜长度／∑足突个数）计算患者足突宽度。分析比较2组患者GBM变薄、增厚、致密层撕裂分层比例和平均FPW及其与AS蛋白尿的关系。结果:持续性蛋白尿组GBM增厚、致密层撕裂分层比例和平均FPW较无/间歇蛋白尿组高（均P<0.05）。平均FPW与GBM增厚、致密层撕裂分层及肾活检年龄均呈正相关（均P<0.01）。结论: AS患者GBM病变程度越重,足突融合越严重,蛋白尿越严重,提示AS基底膜异常有可能通过影响足突及裂孔膜的结构和功能导致蛋白尿发生。     

儿童激素耐药肾病综合征相关致病基因及其临床检测策略

肾病综合征（NS）是因肾小球滤过屏障受损而引起的一绀临床综合征。肾小球滤过屏障由内皮细胞、基底膜和足细胞构成。多项研究表明,足细胞在肾小球滤过屏障中起关键作用,特别是足细胞相邻足突构成的裂隙膜（slitcliaphragm,SD）[1-4]。依据对激素治疗的反虚可将Ns分为激素敏感型（SSNS）和激素耐药型（SRNS）[5]。     

CD2AP、F-actin在肾病大鼠中的表达及意义

目的：观察CD2-associated protein（CD2AP）、肌动蛋白微丝（F-actin）在氨基核苷肾病大鼠肾小球中的表达变化及其意义。 方法： 通过建立大鼠氨基核苷肾病模型，采用免疫组织化学、蛋白质印迹技术观察CD2AP在不同时点肾病大鼠肾小球中的表达和分布变化，采用荧光技术检测肾小球F-actin含量的变化。 结果： ①肾小球足细胞CD2AP的表达在肾病模型建立的早期即有下调；在肾病大鼠蛋白尿的高峰期，CD2AP的表达明显下降（P<0.01）；在肾病大鼠的疾病恢复期，CD2AP的表达逐步恢复正常。②肾小球足细胞CD2AP表达量的变化与肾病大鼠24 h尿蛋白的变化呈负相关（r=-0.865，P<0.01）。③在肾病大鼠蛋白尿的高峰期，肾小球F-actin含量明显下降（P<0.05）。④肾小球CD2AP蛋白表达量和肾小球F-actin荧光定量变化呈正相关（r=0.873，P<0.01）。 结论： ①CD2AP、F-actin的表达变化在蛋白尿的发生机制中有着重要作用。②CD2AP可能是判断肾小球足细胞损伤的一个早期重要指标。     

足细胞上皮间质转分化研究

足细胞是肾小球滤过膜的重要组成部分,在维持肾小球正常滤过功能方面起着至关重要的作用。足细胞上皮间质转分化（EMT）是多种慢性肾脏疾病蛋白尿产生及疾病进展的重要病理机制。减轻足细胞EMT已经成为慢性肾脏疾病防治研究的热点。基于此,本文主要就足细胞的生理特点、EMT病理过程及相关信号通路作一综述。     

抗肾小球基底膜病的靶抗原研究进展

 抗肾小球基底膜（glomerular basement membrane，GBM）病是以循环中抗 GBM 抗体阳性和（或）抗 GBM抗体在肺和（或）肾脏中沉积为特征的一组自身免疫性疾病。该病最早于 1919 年由 Ernest Goodpasture 报道，1958 年 Stanton 和 Tang 报告了 9 例出现肺出血和肾炎的病例，并将其命名为 Goodpasture 综合征。以后，人们又发现部分病人不发生肺出血而仅有肾炎表现，由于其与 Goodpasture综合征共同的特点是均出现抗 GBM 抗体，因此统称为抗 GBM 病[1]。抗 GBM 病是预后最差的肾脏病之一。尽管采用血浆置换和强化免疫抑制治疗，仍有少数患者早期死于肺大出血，多数患者在发病数月内即进入终末期肾衰竭。由于抗 GBM 抗体对于抗 GBM 病具有诊断意义，且在该病的发病中具有重要作用，因此针对其靶抗原的研究对于阐明抗 GBM 病的病因及发病机制具有重要的意义。本文就这一方面的研究进展做一综述。。。。。。     

多形性胶质母细胞瘤中表皮生长因子受体的研究进展

表皮生长因子受体（ epidermal growth factor receptor ， EGFR ）是一种重要的跨膜受体，与细胞增殖、分化、凋亡密切相关。在多形性胶质母细胞瘤（ glioblastoma multiforme ， GBM ）中， EGFR 普遍高扩增高表达，且在部分 GBM 样本中以双微体（ double minute chromosomes ， DMs ）的形式存在，对 GBM 的发生发展，以及不良预后起着重要作用。本文简述了 EGFR 的功能，其与 GBM 的关系及其靶向治疗药物。     

牛血清白蛋白的阳离子化及其在原位免疫复合物型肾炎模型制备中的应用

提高牛血清白蛋白（C-BSA）的等电点，能诱发原位免疫复合物型的肾炎，机制已有证实。C-BSA通过注射进入动物体内可以种植于肾小球的基底膜（GBM），并且与带阴性电荷的GBM发生沉积反应而诱发肾炎。本实验设计并优化了稳定阳离子化牛血清白蛋白的合成方法，并初步验证了应用该产物建立原位复合物型肾炎模型。     

大鼠足细胞损害后肾小球血管生成素的异常表达及其意义

 目的：探讨大鼠足细胞损害后，内源性血管生成素的异常变化及其在进行性肾小球硬化中的病理作用。方法: 选择柔红霉素诱导足细胞损害的大鼠模型作为研究对象，80只健康雄性Wistar大鼠，随机分为假手术(sham)组25只、单侧肾切除(UNx)组25只和UNx ＋柔红霉素（DRB）组30只。DRB组大鼠，摘除左肾后的第7、14 d，从尾静脉注射柔红霉素5 mg·kg-1各1次。然后，分别于造模后的第1、2、4、6、8周，随机取各组大鼠5只，收集24 h尿量，采血取肾，检测24 h尿蛋白定量（24hUPQ）、血肌酐（Scr）和尿素氮（BUN），用PAS染色、免疫组化、原位杂交和透射电镜技术进行病理形态学分析。结果: DRB组的24hUPQ、BUN、Scr显著高于相同时点的sham组和UNx组；肾小球硬化指数（GSI）随病变的进展逐步升高。免疫组化和原位杂交显示，DRB组的肾小球表达Ang1 mRNA和Ang1蛋白下调，表达Ang2 mRNA和Ang2蛋白上调。电镜显示，DRB组逐步出现严重的足细胞损害。Sham组和UNx组的肾小球没有病理改变。DRB组的Ang1 mRNA表达与Ang2 mRNA表达呈负相关；Ang1蛋白表达与Ang1 mRNA表达呈正相关，与Ang2蛋白表达、四型胶原（CoIV）蛋白表达、GSI 、24hUPQ、Bun、Scr呈负相关； Ang2蛋白表达与Ang2 mRNA表达、CoIV蛋白表达、GSI 、24hUPQ、BUN 、Scr之间呈正相关。结论: 足细胞损伤可能是导致肾小球内Ang1和Ang2表达失衡的主要原因，Ang1表达下调，失去对Ang2的抑制，使Ang2表达上调，并介导肾小球滤过膜通透性增高和肾小球硬化的形成。     

Genetics of nephrotic syndrome: new insights into molecules acting at the glomerular filtration barrier

Nephrotic syndrome is caused by increased permeability of the glomerular filtration barrier for macromolecules. The identification of mutations of various podocyte-expressed proteins as causes of familial nephrotic syndrome has significantly contributed to shedding light into the molecular pathogenesis of nephrotic proteinuria and into the physiology of the glomerular sieve. More recent findings have changed our conception of the glomerular filtration barrier from a relatively static structure to a highly dynamic one. Both the multiprotein slit diaphragm complex around nephrin and the integrin receptor complex that mediates binding of the podocyte to the glomerular basement membrane, may translate outside–inside signaling and lead to podocyte actin cytoskeleton rearrangement. This may enable the podocyte network to adapt to environmental changes and respond to injury. Disturbance in these processes may not only be involved in the pathogenesis of hereditary nephrotic syndrome but also in that of more common acquired proteinuric diseases. Elucidation of the molecular mechanisms involved will possibly open the way to new therapeutic approaches.     

Ultrastructural changes of kidney corpuscles in rats with hereditary stress-induced arterial hypertension

Comparative electron microscopic study of glomerular apparatus was performed in 6-month old Wistar rats and in rat strain with inherited stress-induced arterial hypertension (ISIAH). It was shown that this stage of hypertensive status formation was characterized by hypertrophy of renal corpuscles, accompanied by structural changes of all their cellular and noncellular components. These included abrupt capillary constriction or dilation, endothelial flattening, podocyte hypertrophy and flattening of their cytopodia, thickening of basal lamina, mesangial volume expansion and increase in the number of intercapillary processes of mesangial cells. Complex of these signs suggests a disturbance of glomerular capillary blood circulation and a functional podocyte stress, compensating these microcirculatory disturbances. Changes in basal membranes and mesangium are indicative of not only increase in filtration barrier functional load, but also of initial stages of glomerular sclerosis.     

Foothold of NPHS2 mutations in primary nephrotic syndrome

Glomerular podocytes are highly specialized cells with a complex cytoarchitecture. Their most prominent features are interdigitated foot processes with filtration slits in between. These are bridged by the slit diaphragm, which plays a major role in establishing the selective permeability of the glomerular filtration barrier. We searched Medline and Pubmed using the combination of keywords "NPHS2", "podocin", "steroid-resistant nephrotic syndrome," and "genetics" to identify studies describing an association between NPHS2 gene and renal disease. The highly dynamic foot processes contain an actin-based contractile apparatus comparable to that of smooth muscle cells. Mutations affecting several podocyte proteins lead to rearrangement of the cytoskeleton, disruption of the filtration barrier, and subsequent renal disease. The fact that the dynamic regulation of the podocyte cytoskeleton is vital to kidney function has led to podocytes emerging as an excellent model system for studying actin cytoskeleton dynamics in a physiological context. Injury to podocytes leads to proteinuria, a hallmark of most glomerular diseases. Recent studies have led to a considerable increase in our understanding of podocyte biology including composition and arrangement of the cytoskeleton involved in the control of ultrafiltration. Moreover, disturbances of podocyte architecture resulting in the retraction of foot processes and proteinuria appear to be a common theme in the progression of an acquired glomerular disease. In hereditary nephrotic syndromes identified over the last few years, all mutated gene products were localized in podocytes. This review integrates our recent physiological and molecular understanding of the role of podocytes during the maintenance and failure of the glomerular filtration barrier.     

Cell biology of the glomerular podocyte

Glomerular podocytes are highly specialized cells with a complex cytoarchitecture. Their most prominent features are interdigitated foot processes with filtration slits in between. These are bridged by the slit diaphragm, which plays a major role in establishing the selective permeability of the glomerular filtration barrier. Injury to podocytes leads to proteinuria, a hallmark of most glomerular diseases. New technical approaches have led to a considerable increase in our understanding of podocyte biology including protein inventory, composition and arrangement of the cytoskeleton, receptor equipment, and signaling pathways involved in the control of ultrafiltration. Moreover, disturbances of podocyte architecture resulting in the retraction of foot processes and proteinuria appear to be a common theme in the progression of acquired glomerular disease. In hereditary nephrotic syndromes identified over the last 2 years, all mutated gene products were localized in podocytes. This review integrates our recent physiological and molecular understanding of the role of podocytes during the maintenance and failure of the glomerular filtration barrier.     

Effects of the differential expression of ZO‐1 and ZO‐2 on podocyte structure and function

Glomerular podocytes in the kidney originate from columnar epithelial cells possessing tight junctions. During podocyte differentiation, tight junctions are replaced by slit diaphragms, which are formed between foot processes and function as a blood filtration barrier. Although the expression of most tight junction components is suppressed during podocyte differentiation, several components, including ZO‐1 and ZO‐2, are consistently expressed. We recently showed that podocyte‐specific deletion of ZO‐1 gene impaired slit diaphragm formation, leading to proteinuria and glomerular sclerosis. Here, we address the relevance of ZO‐2, whose sequence is highly similar to ZO‐1, in the maintenance of the structure and function of podocytes. In glomerular development, the spatiotemporal expression of ZO‐2 was similar to that of ZO‐1 until the capillary loop stage. Subsequently, the distribution patterns of ZO‐1 and ZO‐2 diverged at the maturation stage, when slit diaphragms are formed. This divergence could partly rely on the ability of ZO‐2 to interact with the slit diaphragm membrane proteins. Podocyte‐specific deletion of the ZO‐2 gene did not cause overt defects; however, double knockout of ZO‐1 and ZO‐2 genes accelerated the defects observed in ZO‐1 knockout mice. These results suggest that ZO‐2 plays supportive roles in the ZO‐1‐dependent regulation of podocyte filtration barrier.     

巢蛋白在阿霉素肾病模型大鼠肾组织中表达及霉酚酸酯的干预作用

背景：研究证明,足细胞损伤是产生肾小球性蛋白尿的重要机制。而关于足细胞内众多骨架蛋白如何互相调节维持足细胞特有的形态目前尚未完全了解,足细胞骨架的构建和重塑也成为蛋白尿发生机制的研究热点。 目的：构建阿霉素微小病变肾病大鼠模型,以霉酚酸酯进行干预,检测大鼠肾组织中巢蛋白(nestin)的表达。 方法：纳入雄性Wistar大鼠36只,随机均分为肾病模型组、霉酚酸酯组、正常组(n=12)。肾病模型组、霉酚酸酯组大鼠一次性尾静脉注射阿霉素进行造模,正常组尾静脉注射等量生理盐水。霉酚酸酯组大鼠于造模次日给予霉酚酸酯灌胃,20 mg/(kg•d),1次/d;其他两组大鼠每日给予等量生理盐水。各组分别于造模后14,21,28 d各处死4只大鼠,取肾皮质进行苏木精-伊红染色和免疫组化染色,观察大鼠肾组织病理学改变以及nestin表达情况。 结果与结论：正常组大鼠肾小球滤过膜结构完整,上皮细胞足突清晰;肾病模型组大鼠肾小球上皮细胞足突广泛融合,基底膜正常;霉酚酸酯组大鼠肾小球上皮细胞足突部分融合,但病变较轻。免疫组化结果提示从造模第14天开始,肾病模型组和霉酚酸酯组大鼠nestin表达明显增加,与正常组比较差异有显著性意义(P < 0.05);霉酚酸酯组大鼠nestin表达低于肾病模型组,差异有显著性意义(P < 0.05)。提示肾小球足细胞损伤时,足细胞内nestin表达增多,随病情加重而表达增高。霉酚酸酯可以减轻足细胞损伤,下调nestin的表达,维持足细胞的正常结构,达到延缓肾脏损害的目的。 中国组织工程研究杂志出版内容重点：肾移植;肝移植;移植;心脏移植;组织移植;皮肤移植;皮瓣移植;血管移植;器官移植;组织工程      

Pathophysiologic implications of reduced podocyte number in a rat model of progressive glomerular injury

Changes in podocyte number or density have been suggested to play an important role in renal disease progression. Here, we investigated the temporal relationship between glomerular podocyte number and development of proteinuria and glomerulosclerosis in the male Munich Wistar Fromter (MWF) rat. We also assessed whether changes in podocyte number affect podocyte function and focused specifically on the slit diaphragm-associated protein nephrin. Age-matched Wistar rats were used as controls. Estimation of podocyte number per glomerulus was determined by digital morphometry of WT1-positive cells. MWF rats developed moderate hypertension, massive proteinuria, and glomerulosclerosis with age. Glomerular hypertrophy was already observed at 10 weeks of age and progressively increased thereafter. By contrast, mean podocyte number per glomerulus was lower than normal in young animals and further decreased with time. As a consequence, the capillary tuft volume per podocyte was more than threefold increased in older rats. Electron microscopy showed important changes in podocyte structure of MWF rats, with expansion of podocyte bodies surrounding glomerular filtration membrane. Glomerular nephrin expression was markedly altered in MWF rats and inversely correlated with both podocyte loss and proteinuria. Our findings suggest that reduction in podocyte number is an important determinant of podocyte dysfunction and progressive impairment of the glomerular permselectivity that lead to the development of massive proteinuria and ultimately to renal scarring.     

Podocalyxin与糖尿病肾病的关系

足细胞标记蛋白(podocalyxin)作为足突顶端质膜的主要构成部分,是足突顶膜区主要的带负电荷的唾液酸蛋白,参与维持足细胞的正常结构和滤过屏障。糖尿病肾病早期以肾脏肥大和肾小球高滤过为特征。在肾小球足细胞的检测中,podocalyxin作为最常用的标记蛋白之一,对监测肾小球疾病的发生和发展起到极其重要的作用。深入研究podocalyxin对糖尿病肾小球病变的早期诊断及治疗有着重要的指导意义。     

Endothelin B receptor-like immunoreactivity in podocytes of the rat kidney

The distribution of endothelin B receptor (ETBR)-like immunoreactivity in the rat renal glomerulus was investigated using an affinity-purified antibody against a synthetic peptide corresponding to the amino acid residues 425-439 of the rat ETBR. Light microscopy showed ETBR-like immunoreactivity to be localized predominantly near the glomerular blood capillaries. By immunoelectron microscopy using the pre-embedding method, intense immunodeposits indicating ETBR were detected in podocytes, particularly in their foot processes, in contrast with the weak immunoreaction in endothelial cells of the glomerular blood capillaries and in the mesangial cells. In sections stained with the post-embedding method using immunogold particles, positive signals were also found on the plasma membrane of podocyte foot processes as well as the cytoplasm just beneath the cell membrane. These findings suggest that endothelin stimulates ETBR mainly on podocytes, thus resulting in a decrease of the glomerular blood flow and glomerular filtration rates.