猪后肾帽状间充质细胞发育为肾小球足细胞的过程

目的:探讨中国实验用小型猪肾小球足细胞的发育过程。方法:应用过碘酸-希夫氏染色观察中国实验用小型猪胚胎不同时间点(胚胎28d至出生后21d,以周为单位,共17个时间点)肾小球发育过程中的形态学变化。应用免疫荧光技术检测猪胚肾不同阶段(帽状间充质、肾小囊体、逗号形体、"S"形体、毛细血管袢期肾小球、成熟肾小球)足细胞的发育过程。结果:猪在胚胎第28天(E28d)后肾已开始发育,可见典型的帽状间充质、肾小囊体、逗号形体和"S"形体;E35d可见肾小球形成,包括近皮质的不成熟肾小球以及近髓质的成熟肾小球。胚肾组织免疫荧光染色显示:胚肾早期足细胞标志物WT1表达于Six2阳性的后肾帽状间充质细胞,相继表达于肾小囊体、整个逗号形体、逗号形体尾部以及"S"形体下端,最终局限于肾小球足细胞。结论:中国实验用小型猪的足细胞来源于Six2阳性的后肾帽状间充质细胞,经过肾小囊体、逗号形体、"S"形体、毛细血管袢期肾小球阶段,发育成为成熟肾小球的足细胞。     

IgA肾病患者外周血内皮祖细胞的检测及意义

IgA肾病(IgAN)在我国原发性肾小球肾炎中,是导致慢性肾衰竭的首位病因.IgAN的病理特点是肾小球系膜细胞增生和系膜外基质增多.由于系膜区与毛细血管袢内皮直接连接无基底膜的特点,当系膜基质与系膜细胞发生免疫炎性反应时,会直接导致内皮细胞的损伤,甚至坏死.血管内皮祖细胞(endothelial progenitor cells,EPCs)是血管内皮细胞(endothelial cells,ECs)的前体细胞1,推测EPCs的数量及功能在IgAN发生发展中起至关重要的作用.     

机械力学对体外培养系膜细胞的影响

系膜细胞 (ｍｅｓａｎｇｉｕｍｃｅｌｌ,Ｍｃ)位于肾小球毛细血管小叶中央 ,是肾小球内最活跃的固有细胞 ,它能合成基质 ,并能分泌细胞因子和血管活性物质[1] ,是血管活性物质、炎性介质的靶细胞 ,系膜细胞在介导肾小球疾病发生发展过程中起重要作用。Ｍｃ和系膜基质一起共同构成系膜 ,对肾小球起支撑作用。系膜同毛细血管连接处无基底膜 ,内皮细胞和系膜细胞之间仅存在系膜基质 ,这种解剖结构使系膜细胞能敏感地感受毛细血管腔内的压力变化。压力通过内皮细胞、系膜基质传递到系膜细胞。系膜具有弹性 ,肾小球毛细血管扩张牵拉系膜使系膜细…     

人肾小球实质细胞与肾脏疾病机制诊疗进展

肾小球包括毛细血管球（CapG）和肾小囊。CapG实质细胞[毛细血管内皮细胞（GEC）＋系膜细胞（GMC）＋G上皮细胞（VC）]维持正常结构和滤过、内外分泌功能，肾内肾素一血管紧张素系统（RAS）参与高血压、炎症、纤维化及组织修复。其中入球小动脉（A人）平滑肌和VC含全套RAS成份[1]。实质细胞参与肾脏损伤修复。免疫、炎症、病生和遗传变异等是各型肾脏疾病基本机制。深化认识，可促急慢性肾损诊疗预后。     

大鼠骨髓间充质干细胞体外定向诱导分化成平滑肌细胞

目的分离培养大鼠骨髓间充质干细胞(BMSCs)并体外定向诱导分化成平滑肌细胞,为BMSCs移植治疗勃起功能障碍(ED)大鼠模型提供种子细胞。方法分离培养大鼠BMSCs,取第3~4代细胞,流式细胞术检测BMSCs表面分子CD49d、CD73、CD90、CD105和CD106、造血干细胞表面分子CD34和CD45、血管内皮细胞特异性表面分子CD31表达情况,采用平滑肌细胞诱导培养基诱导分化,通过免疫荧光检测α-平滑肌肌动蛋白(α-SMA)和结蛋白(Desmin)进行鉴定细胞分化。结果培养细胞阳性表达BMSCs表面分子CD49d、CD73、CD90、CD105和CD106,同时造血干细胞表面分子CD34和CD45及血管内皮细胞表面分子CD31阴性表达,且经过平滑肌细胞诱导培养基诱导分化后α-SMA和Desmin免疫荧光检测均阳性反应。结论成功从大鼠骨髓中分离培养BMSCs,为BMSCs和基因修饰BMSCs移植治疗ED提供种子细胞。     

内皮细胞与肾脏

肾小球内皮细胞(Glomerular Endothelialcell)与肾小球基膜(GBM)、系膜细胞(Mesangial cell)、细胞外基质(ExtracellularMatrix)以及毛细血管腔(capillary lumen)紧密结合,组成内皮毛细血管区(endocapillary region)。肾小球内皮毛细血管区在维持肾脏功能及肾小球损伤和修复中起着重要作用,肾小球内皮细胞的作用日益受到重视。随着细胞培养技术的进步及细胞生物学和分子生物学技术的应用,对肾小球内皮细胞的认识进一步深入。本文就有关最新进展综述如下: 肾小球内皮细胞的培养迄今为止,肾小球内皮细胞的分离和培养尚无可靠的方法,即使在各种肾小球细胞共同培养中,肾小     

慢性乙型肝炎合并淀粉样变性肾病1例报道与分析

目的 探讨淀粉样变性肾病的病理学特点,为临床诊断提供依据. 方法 对本院1例慢性乙肝合并淀粉样变性肾病患者的病例资料,如血常规、尿常规、生化、肾脏穿刺病理等结果进行回顾性分析总结. 结果 本例病理诊断为淀粉样变性肾病,AA型.光镜下系膜区可见团块状均质无结构物质沉积,管壁可见均质物质沉积;电镜下肾小球系膜细胞和血管壁无细胞性增宽伴淀粉样细纤维结构分布,上皮足突节段融合;刚果红染色肾小球系膜区以及血管壁沉积的团块样物质呈砖红色,在偏光下呈苹果绿双折光,肾间质无明显病变;免疫荧光IgM沿系膜区和毛细血管袢弥漫颗粒状沉积,荧光强度+++;IgG、IgA、C3、C1q沿系膜区和毛细血管袢弥漫性颗粒状沉积,荧光强度++,C4沿系膜区和毛细血管袢弥漫性颗粒状沉积,荧光强度+. 结论 本病例诊断为慢性乙型病毒肝炎合并继发性肾脏淀粉样变性,淀粉样变性肾病病理特征明确;本例是否为HBV感染后发生的肾淀粉样变性以及相关机制需要复查肾组织乙肝免疫荧光、或者行原位杂交检测肾组织内乙肝病毒DNA.     

新生小鼠足细胞损伤对肾小球发育的影响

目的 探讨新生小鼠中足细胞损伤对肾小球发育的影响及其机制。 方法 于新生ICR小鼠出生后1 d注射嘌呤霉素(puromycin aminonucleoside，PA)，并以注射生理盐水作为对照。观察出生后第2、4、8、12、30、60、90天时肾重/体重、尿蛋白、血压及组织学的改变。应用免疫组化及定量RT-PCR方法测定肾皮质内肾母细胞瘤基因(WT-1)、CD31、血管内皮生长因子(VEGF)及其受体Flk-1、血管生成素(angiopoietin，Ang-1、Ang-2)及其受体Tie-1、Tie-2的表达水平。 结果 注射PA后，新生小鼠肾重、体重均明显低于对照组。出生后第2天(注射PA后1 d)时，肾小球足细胞出现足突广泛融合和微绒毛的脱落；第12天时，肾小球内CD31的表达明显下降，部分肾小球萎缩、发育不良，肾皮质浅层小球成熟指数明显下降；第30天时，原先发育不良的肾小球逐渐被吸收；第60天时，剩余肾小球出现系膜区的扩张和小球节段性硬化。PA鼠在第30天时出现蛋白尿；第60天时血压显著增高。定量RT-PCR显示，第2天时肾皮质Ang-1表达明显上调，Flk-1及Tie-2明显下降。 结论 PA可以在早期损伤的新生ICR小鼠足细胞，改变VEGF、血管生成素系统的表达，导致肾小球毛细血管袢发育不良及在后期产生蛋白尿、高血压和肾小球硬化。     

银杏制剂对糖尿病致早期肾衰竭患者血糖、血脂及IL-6的影响

据文献报道肾脏在病理状态下白细胞介素（IL-6）水平明显增高[1],由于糖尿病患者的高血糖状态,使肾小球血管内皮细胞损伤,受损的内皮细胞导致系膜细胞病变,IL-6产生增多,增多的IL-6反过来刺激系膜细胞增生,细胞外基质增多,这种恶性循环造成肾小球功能性肾单位减少,最终导致肾小球     

血小板/内皮细胞粘附分子在急性排斥反应时表达的研究

应用免疫级化SP法和计算机图像分析系统观察分析18例急性排斥反应时移植肾活检标本中血小板／内皮细胞粘附分子（PECAM－1，CD31）的表达。结果显示急性排斥反应时肾小球毛细血管内皮细胞中PECAM－1阳性反应强度较正常明显减低或由阳性转为阴性，而在肾小管上皮中表达增强；PECAM－1与HLA－DR抗原在肾小球和肾小管中的表达呈平行关系。提示细胞粘附分子PECAM－1对移植肾急性排斥反应有一定诊断意义。     

An immunohistochemical study of developing glomeruli in human fetal kidneys

BACKGROUND: In the glomerulonephritis, mesenchymal cells frequently repeat the expression of fetal immunohistochemical phenotypes. However, in human glomerulogenesis the phenotypic alteration of mesangial and other types of glomerular cells has not been clearly defined. Our aim was to clarify the characteristics of fetal mesangial cells and glomerular capillary endothelial cells, as well as their changes during glomerulogenesis using immunohistochemistry. METHODS: We examined the renal tissues of 34 autopsied fetuses and neonates, 5 children, and 5 adults using immunohistochemistry and immunoelectron microscopy, using antibodies for cytoskeletons, contraction-associated proteins, and endothelial cell markers. RESULTS: In the V and S stages, there were no cells showing mesangial and endothelial features within the vesicles and the S-shaped bodies. In the S stage, small blood vessels, consisting of endothelial cells (CD31+, CD34+) and primitive perivascular mesenchymal cells (alpha-smooth muscle actin+, low molecular caldesmon+, vimentin+), were branched from developing interlobular arteries and appeared to extend to the lower clefts of the S-shaped bodies. In the C stage, the perivascular mesenchymal cells aggregated at the root of the immature glomeruli. In the M stage, they migrated toward the periphery of immature glomeruli and gradually lost their fetal immunohistochemical features. Similarly, with further maturation, the fetal glomerular capillary endothelial cells gradually lost the immunostaining for CD34, while the strong staining intensity of CD31 remained unchanged, just as that in the adult glomerular capillary endothelial cells. CONCLUSIONS: In human glomerulogenesis, we demonstrate that fetal mesangial and capillary endothelial cells change their immunohistochemical phenotypes with maturation. They gradually lose fetal immunohistochemical phenotypes. Already before birth, the mesangial cells in almost all glomeruli at the late M stage acquire the adult phenotype.     

How do mesangial and endothelial cells form the glomerular tuft?

The glomerular capillary tuft is a highly intricate and specialized microvascular bed that filters plasma water and solute to form urine. The mature glomerulus contains four cell types: Parietal epithelial cells that form Bowman's capsule, podocytes that cover the outermost layer of the glomerular filtration barrier, glycocalyx-coated fenestrated endothelial cells that are in direct contact with blood, and mesangial cells that sit between the capillary loops. Filtration begins only after the influx and organization of endothelial and mesangial cells in the developing glomerulus. Tightly coordinated movement and cross-talk between these cell types is required for the formation of a functional glomerular filtration barrier, and disruption of these processes has devastating consequences for early life. Current concepts of the role of mesangial and endothelial cells in formation of the capillary tuft are reviewed here.     

Developmental patterns of PDGF B-chain, PDGF-receptor, and alpha-actin expression in human glomerulogenesis.

Expression of PDGF B-chain and the PDGF receptor beta-subunit (PDGFR beta) is detected immunocytochemically during the development of glomeruli in human kidneys of 54 to 105 days gestational age. During the early stages (vesicular, comma-shape and S-shape) of glomerulogenesis, PDGF B-chain is localized to differentiating epithelium of the glomerular vesicle, while PDGFR beta is expressed in the undifferentiated metanephric blastema, vascular structures, and interstitial cells. During this stage PDGF may be acting as a paracrine growth factor and as a chemoattractant acting to recruit mesangial progenitor cells into the developing glomerulus. As the glomerular tuft forms, both PDGF B-chain and PDGFR beta can be detected in an arboreal pattern radiating from the hilus of the glomerular tuft. Immunocytochemical studies using markers specific to endothelium (Ulex europaeus I lectin, Factor VIII related antigen), and smooth muscle (alpha-smooth muscle actin), indicate that the PDGF B-chain and PDGFR beta are both expressed primarily by mesangial cells. During this stage, PDGF may be acting primarily to provide an autocrine factor to mediate further mesangial cell proliferation. Glomerular expression of alpha-smooth muscle actin is limited to later stages of glomerulogenesis; at these stages the pattern of expression is similar to that of PDGF-B chain and PDGFR beta. The upregulation of mesangial PDGF, PDGFR beta, and alpha-smooth muscle actin expression that has been identified in some disease states in both humans and experimental animals appears to represent a recapitulation of this normal developmental process.     

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.     

Development of the glomerular mesangium

The development of the glomerular mesangium was studied in fetal and newborn rat kidneys by using a widefield electron microscope which can cover a whole glomerulus within one low-power viewfield. A three-dimensional observation of the immature glomeruli was done by performing ultrathin serial sectionings of the specimen for electron microscopy. Scanning electron microscopic observation of the developing glomeruli was also performed. The developmental distribution of contractile protein (actin) in mesangial cells and the main intrinsic component of the extracellular matrix protein (type IV collagen) of the mesangium were examined by immunohistological techniques. The widefield electron micrograph revealed a precise relationship between the mesangium and other components of the glomerulus. The results confirmed that the capillary extends into the S-shaped body from the sur-rounding vascular system at the initiation of nephronogenesis. The mesangial cells are always continuous to the vascular pericyte-smooth muscle cell system during the whole course of glomerular development and they participate in the sub-division of the capillary network during glomeru-logenesis. Morphological findings and the changing distribution of intra- and extracellular proteins of the mesangium during development suggest that the mesangial cell differentiates from the primitive pericyte of the immature capillary.     

Renin Lineage Cells Repopulate the Glomerular Mesangium after Injury

Mesangial cell injury has a major role in many CKDs. Because renin-positive precursor cells give rise to mesangial cells during nephrogenesis, this study tested the hypothesis that the same phenomenon contributes to glomerular regeneration after murine experimental mesangial injury. Mesangiolysis was induced by administration of an anti-mesangial cell serum in combination with LPS. In enhanced green fluorescent protein–reporter mice with constitutively labeled renin lineage cells, the size of the enhanced green fluorescent protein–positive area in the glomerular tufts increased after mesangial injury. Furthermore, we generated a novel Tet-on inducible triple-transgenic LacZ reporter line that allowed selective labeling of renin cells along renal afferent arterioles of adult mice. Although no intraglomerular LacZ expression was detected in healthy mice, about two-thirds of the glomerular tufts became LacZ positive during the regenerative phase after severe mesangial injury. Intraglomerular renin descendant LacZ-expressing cells colocalized with mesangial cell markers α8-integrin and PDGF receptor-β but not with endothelial, podocyte, or parietal epithelial cell markers. In contrast with LacZ-positive cells in the afferent arterioles, LacZ-positive cells in the glomerular tuft did not express renin. These data demonstrate that extraglomerular renin lineage cells represent a major source of repopulating cells for reconstitution of the intraglomerular mesangium after injury.     

Non-muscle myosin IIA is required for the development of the zebrafish glomerulus

Mutations in the MYH9 gene, coding for the non-muscle myosin heavy chain IIA (NMHC-IIA), are responsible for syndromes characterized by macrothrombocytopenia associated with deafness, cataracts, and severe glomerular disease. Electron microscopy of renal biopsies from these patients found glomerular abnormalities characterized by alterations in mesangial cells, podocytes, and thickening of the glomerular basement membrane. Knockout of NMHC-IIA in mice is lethal, and therefore little is known about the glomerular-related functions of Myh9. Here, we use zebrafish as a model to study the role and function of zNMHC-IIA in the glomerulus. Knockdown of zNMHC-IIA resulted in malformation of the glomerular capillary tuft characterized by few and dilated capillaries of the pronephros. In zNMHC-IIA morphants, endothelial cells failed to develop fenestrations, mesangial cells were absent or reduced, and the glomerular basement membrane appeared nonuniformly thickened. Knockdown of zNMHC-IIA did not impair the formation of podocyte foot processes or slit diaphragms; however, podocyte processes were less uniform in these morphants compared to controls. In vivo clearance of fluorescent dextran indicated that the glomerular barrier function was not compromised by zNMHC-IIA knockdown; however, glomerular filtration was significantly reduced. Thus, our results demonstrate an important role of zNMHC-IIA for the proper formation and function of the glomerulus in zebrafish.     

Glomerular morphometry of adriamycin-induced focal and segmental glomerulosclerosis in the rat.

The present paper presents a morphometric study of the evolution of the glomerulus in Adriamycin-induced focal and segmental glomerulosclerosis in the rat over 32 weeks. The morphometric parameters studied generally varied significantly when the groups treated with Adriamycin were compared with controls. Glomerular area and perimeter showed an irregular pattern and finally ended up with values similar to those of the control group. Glomerular capillary tuft area and perimeter were always significantly greater in Adriamycin-treated groups than in controls. The mesangial area of treated animals increased over the study period in comparison with that of controls. While the total number of cells in the glomerular capillary tuft had an irregular pattern, the proportion of cells in relation to glomerular capillary tuft area was significantly lower in treated animals than in controls.