硒酸锌金属自显影技术检测游离锌离子在小鼠肾脏的分布

目的研究游离锌离子在小鼠肾脏的定位分布。方法应用硒酸锌金属自显影技术(ZnSeAMG)检测小鼠肾脏内的游离锌离子分布。结果游离锌离子在肾脏内分布广泛,皮质中有大量AMG反应阳性颗粒,髓质中的AMG阳性颗粒较少。其中,近曲小管、远曲小管、近直小管和远直小管上皮细胞近腔侧均分布有大量的棕黑色AMG阳性颗粒,肾小体、细段和集合管上皮细胞中AMG阳性颗粒较少。结论小鼠肾脏内含有丰富的游离锌离子,锌离子可能参与肾脏的功能。     

ZnT1及游离锌离子在小鼠骺板软骨细胞的定位研究

目的研究锌转运体-1(Zinc transporter 1,ZnT1)和游离锌离子在小鼠骺板软骨细胞的定位分布,探讨ZnT1影响骺板软骨细胞锌离子代谢从而参与骨骼生长的可能机制。方法应用浸入式金属自显影技术(AMG)观察锌离子在小鼠肋骨骺板内的定位分布;应用免疫组织化学SABC法检测ZnT1在小鼠骺板软骨细胞的表达。结果金属自显影技术显示游离锌离子在小鼠肋骨骺板肥大带、增殖带和静止带三层区域结构内有不同程度的表达,其中肥大带软骨细胞层锌离子含量最高;ZnT1免疫阳性反应产物主要定位于软骨细胞膜附近,在小鼠肋骨骺板三层区域结构内有不同程度的表达,从肥大带到静止带,软骨细胞膜上的ZnT1免疫反应逐渐减弱。结论小鼠肋骨骺板内存在大量的游离锌离子和ZnT1蛋白,提示ZnT1可能参与锌离子在软骨细胞的转运和代谢,在骨的形成和发育过程中发挥作用。     

锌转运体ZNT7在小鼠视网膜的定位分布

目的研究锌转运体-7(zinc transporter 7,ZNT7)在小鼠视网膜的定位和分布。方法应用免疫组织化学技术检测CD-1小鼠视网膜内的ZNT7免疫反应产物的表达。结果ZNT7在小鼠视网膜内分布广泛,在神经节细胞和色素上皮细胞内ZNT7免疫阳性反应产物的表达最丰富,在无长突细胞和视神经纤维层中ZNT7免疫阳性反应产物为中等程度的表达,在内网层、外网层和光感受器外节中ZNT7免疫阳性染色较淡,在外核层和光感受器内节中ZNT7几乎没有表达。结论ZNT7可能在维持视网膜锌稳态过程中起到重要的作用。     

硒酸锌金属自显影技术检测游离锌离子在小鼠卵巢的分布

目的研究游离锌离子在小鼠卵巢的定位分布。方法应用硒酸锌金属自显影技术(ZnSeAMG)检测小鼠卵巢内的游离锌离子分布。结果游离锌离子在卵巢内分布广泛,在原始卵泡、初级卵泡、次级卵泡、闭锁卵泡以及间质细胞中都有大量棕黑色的AMG染色颗粒。结论小鼠卵巢内含有丰富的游离锌离子,锌离子可能参与了卵泡的发育以及性激素的合成。     

ZnT7及游离锌离子在小鼠室管膜和脉络丛细胞的分布

目的 研究锌转运体7（ZnT7）和游离锌离子在小鼠脊髓室管膜和脉络丛上皮细胞中的分布.方法 应用ZnSe金属自显影技术（AMG）检测硒酸钠注射1.5h后小鼠脊髓室管膜细胞及脑室脉络丛上皮细胞的游离锌离子;应用免疫组织化学SABC法检测小鼠脊髓室管膜细胞及脑室脉络丛上皮细胞中ZnT7的表达.结果 光镜下观察AMG染色的切片,小鼠脊髓室管膜细胞及脑室脉络丛上皮细胞中均有游离锌离子的分布;免疫组织化学结果表明,脊髓室管膜细胞及脉络丛上皮细胞中均有ZnT7的表达,且与游离锌离子分布区域基本一致.结论 锌离子可能在脊髓室管膜细胞及脉络丛上皮细胞内发挥重要作用,脊髓室管膜细胞及脉络丛上皮细胞可能在脑脊液锌转运过程中发挥重要的作用.     

血管紧张素Ⅱ受体1和受体2在小鼠肾脏发育中的表达

目的观察小鼠肾脏发育中血管紧张素Ⅱ受体1(AngiotensinⅡreceptor type1,AT_1)和受体2 (AT_2)的表达特征,探讨小鼠肾脏发育过程中AT_1和AT_2的作用及相互关系。方法应用免疫组织化学技术、免疫印迹法(Western blot)并结合体视学方法检测胚龄12、14、15、16、18d及生后日龄1、3d小鼠肾脏发育中AT_1和AT_2的表达。结果AT_1和AT_2均首先出现在输尿管芽,然后出现在肾小管,生后表达逐渐减弱。早期肾小体内AT_2丰富表达,随着肾小体的成熟表达量逐渐降低。结论在小鼠肾脏发育中,AT_1可能与输尿管芽分支不断延长以及肾小管的增殖密切相关,AT_2可能与输尿管芽和肾小体的相互诱导相关。     

乳腺癌细胞株MCF-7中锌和锌转运体表达的关系

目的： 通过ZnCl2和TPEN处理培养人乳腺癌细胞株MCF-7，观察高锌和低锌两种状态下锌转运体mRNA的表达情况。方法: 0、50、100、150和200 μmol/L的ZnCl₂以及0、5、10和15 μmol/L的TPEN分别处理培养MCF-7细胞12 h，细胞存活率用噻唑蓝（MTT）方法检测；荧光锌离子探针Zinquin检测细胞内锌离子含量；RT-PCR方法检测锌转运体（ZnT）mRNA的表达。结果: ZnCl₂（浓度为150 μmol/L和200 μmol/L时）以及TPEN对MCF-7细胞均有生长抑制作用。ZnCl₂处理后的MCF-7细胞内锌离子含量显著升高，TPEN处理后的MCF-7细胞内锌离子含量显著降低。与对照细胞相比，ZnCl₂处理的细胞ZnT-1 mRNA的表达水平随着ZnCl₂浓度增加而依次升高；TPEN处理的细胞ZnT-1 mRNA表达水平则普遍降低；ZIP2和ZIP10 mRNA的表达水平随TPEN浓度的增加而依次升高。结论: 高锌促进人乳腺癌MCF-7细胞ZnT-1 mRNA的表达；低锌抑制人乳腺癌MCF-7细胞ZnT-1 mRNA表达，促进ZIP2和ZIP10 mRNA的表达。     

游离锌离子在小鼠颈上神经节的分布

目的研究游离锌离子在小鼠交感节后神经元中的分布。方法应用ZnSe金属自显影技术和透射电镜检测硒酸钠注射1.5和24 hr后小鼠颈上神经节内的游离锌离子。结果注射硒酸钠1.5 hr后的小鼠颈上神经节中几乎所有的神经元均有锌阳性反应产物分布,透射电镜下观察锌离子主要分布于神经元细胞核周围的高尔基复合体和小泡状结构内。注射硒酸钠24 hr后有锌阳性反应的神经元约为10%,提示锌离子在交感节后神经轴突内进行轴突运输。结论小鼠颈上神经节神经元胞体内含有丰富的游离锌离子,游离锌离子在轴突内进行轴突运输。     

锌离子在小鼠肺组织分布的TSQ荧光研究

目的研究游离锌离子在小鼠肺组织的定位分布。方法应用TSQ荧光技术检测小鼠肺组织内的锌离子。结果荧光显微镜下可见被TSQ荧光标记的锌离子广泛的分布在肺叶支气管壁粘膜、粘膜下及软骨,肺内小支气管基膜,肺泡上皮和肺内血管平滑肌,尤其以肺叶支气管粘膜以及软骨中荧光染色最为明显。结论小鼠肺组织内含有丰富的锌离子可能参与肺泡上皮细胞以及肺各级支气管软骨细胞中某些蛋白质的合成和组装。     

增殖细胞核抗原在小鼠生后肾脏发育中的表达

目的：观察小鼠出生后肾脏发育过程中增殖细胞核抗原（PCNA）的表达特征,探讨出生后小鼠肾脏发育过程中细胞增殖的规律。方法：应用免疫组织化学技术检测小鼠出生后1、3、7、14、21、28和70d肾脏PCNA的表达。结果：小鼠出生后1～70d,皮质中的生肾区、肾小体、肾小管、髓放线以及髓质中的肾小管和集合管PCNA阳性细胞的表达具有一定的规律,早期PCNA阳性表达丰富,随着肾脏发育逐渐成熟而表达减弱直至消失。在70d成年小鼠肾脏中,没有检测到PCNA阳性细胞。结论：出生后小鼠肾脏皮质中的生肾区、肾小体、肾小管、髓放线以及髓质中小管的细胞增殖规律是由高逐渐降低的,直至成年完全停止。     

人胆酸转运蛋白基因的克隆、亚细胞定位及其在肾组织中的表达

目的：克隆人肾与小肠ASBT（顶端Na+/胆汁酸协同转运蛋白）基因并比较2者的序列差别，明确ASBT蛋白在肾小管上皮的亚细胞定位及在人肾组织中的表达情况。方法:从人肾和小肠组织中提取总RNA，然后用带有8肽FLAG标签的PCR引物通过RT-PCR技术扩增ASBT全长cDNA基因并测序，并将其插入真核表达载体中构建ASBT蛋白真核表达载体，然后将其转染到肾小管上皮细胞LLC-PK1中表达并用免疫荧光-激光共聚焦显微镜观察该蛋白的亚细胞定位情况。用免疫组化技术观察ASBT在人肾组织中的表达分布。结果:序列分析结果表明肾小管ASBT基因的序列与小肠ASBT序列完全一致。Western blotting表明ASBT基因在LLC-PK1细胞中得到了正确的表达。共聚焦显微镜分析显示正常ASBT蛋白主要定位于肾小管上皮细胞膜上，与生物信息学的预测结果一致。免疫组化染色表明ASBT蛋白主要表达于人近端肾小管上皮的刷状缘侧，在间质及远端小管没有表达。结论:人肾小管ASBT基因序列与小肠ASBT相同，ASBT蛋白主要表达于近端肾小管上皮细胞管腔侧细胞膜。     

Transcellular water transport and stability of expression in aquaporin 1-transfected LLC-PK1 cells in the development of a portable bioartificial renal tubule device

We investigated a portable bioartificial renal tubule device (BRTD) consisting of renal tubule cells and hollow fibers, to improve the quality of life of patients. It is necessary for a BRTD system to be compact. A compact portable BRTB requires transfection of an appropriate water channel or electrical pump genes in tubular epithelial cells, which should be based on physiological similarities to human kidney function. LLC-PK(1) cells, into which rat kidney aquaporin 1 (AQP1) cDNA was stably transfected, were evaluated for water transport ability. The expression and localization of water AQP1 were examined by Western blotting, RT-PCR, and immunofluorescence. To measure transcellular water permeation, a simple method was applied, using phenol red as a cell-impermeant marker of concentration. In contrast to wild-type LLC-PK(1) cells, rat AQP1-transfected cells had high transcellular osmotic water permeability. The expression of rat AQP1 mRNA (ratio of AQP1 to beta-actin mRNA) and protein bands (a 28-kDa band and a broad, 35- to 45-kDa band) was confirmed to be stably maintained until a population doubling level of 24. In AQP1-transfected LLCPK(1) cells, the protein was localized mainly to the basolateral side, but also the apical side, of the plasma membrane. Wild-type LLC-PK(1) cells were not stained at the plasma membrane. It is possible that enough AQP1-transfected tubule epithelial cells were supplied for a bioartificial renal tubule device.     

Distribution and regulation of expression of serum- and glucocorticoid-induced kinase-1 in the rat kidney

The serum- and glucocorticoid-induced kinase-1 (sgk1) increases the activity of a number of epithelial ion channels and transporters. The present study examines the distribution and subcellular localization of sgk1 protein in the rat kidney and the regulation of levels of expression induced by steroids. The results indicate that the kidney expresses predominantly the sgk1 isoform with a distribution restricted to the thick ascending limb of Henle, distal convoluted, connecting and cortical collecting tubules. Within cells, sgk1 strongly associates with the microsomal fraction of homogenates and it colocalizes with the Na⁺,K⁺-ATPase to the basolateral membrane. Analysis of the levels of expression of sgk1 by Western blotting and immunohistochemistry indicates constitutive high expression under basal conditions. Approximately half of the basal level is maintained by glucocorticoids whereas physiological fluctuations of aldosterone produce minor changes in sgk1 abundance in adrenal-intact animals. These results do not support the notion that physiological changes of aldosterone concentration turn the expression of sgk1 'on and off' in the mammalian kidney. Additionally, localization of sgk1 to the basolateral membrane indicates that the effects mediated by sgk1 do not require a direct interaction with the ion channels and transporters whose activity is modulated, since most of these proteins are located in the apical membrane of renal epithelial cells.     

Adult stem cell-like tubular cells reside in the corticomedullary junction of the kidney

The existence of adult renal stem cells has long been suspected because the kidney is capable of regeneration in response to injury, such as acute tubular necrosis (ATN), but their location, or niche, has not been fully defined yet. The aim of this study was to identify the niche of adult renal stem cells responsible for the tubular regeneration. The location of label-retaining cells (LRCs) was studied in adult mouse kidneys after administration of a pulse of bromodeoxyuridine (BrdU) during embryonic period. To study regional participation in renal tubular regeneration, the expression of the proliferation marker Ki-67 was examined after induction of unilateral ATN in mouse kidneys. Regional colony-forming capacity was examined using cultured cells derived from normal mouse and human kidneys and their multipotency was examined in human kidneys. LRCs in adult mouse kidneys were mostly tubular epithelial cells and concentrated constantly in the outer stripe of the corticomedullary junction (CMJ). In the ATN model, Ki-67 positive cells were concentrated in the tubular epithelial cells of the outer stripe, not only in the ATN kidneys but also in the contralateral non-ATN kidneys. High colony-forming capacity was noted in the CMJ of mouse and human kidneys. Cultured cells derived from a single human CMJ cell revealed multipotency, differentiating not only into tubular cells but also into glomerular podocytes. These results demonstrate that the CMJ of the kidney contains label-retaining, renal-repairing, highly colony-forming multipotent stem cell-like tubular cells, suggesting the CMJ as the niche of adult renal stem cells.     

扬子鳄（Alligator sinensis）肾的超微结构

用透射电镜观察扬子鳄肾的超微结构。它的近曲小管和收集管上皮细胞无质膜内褶，远曲小管上皮细胞有较少的质膜内褶。扬子鳄肾小管的这些结构特征与它们在淡水生活有关。本文还就扬子鳄的栖息环境及其肾的超微结构与关咸水生活的美洲鳄进行了比较。     

Sodium transport-related proteins in the mammalian distal nephron – distribution, ontogeny and functional aspects

The mammalian distal nephron plays a pivotal role in adjusting urinary sodium excretion. Successive portions of the renal tubule are formed to adapt to this function, and an axial heterogeneity of the distal segments has been defined. The specific transport properties of these epithelia are accomplished by the expression of proteins (cotransporters, exchangers, channels) governing the movement of ions on either cell side. Molecular cloning of these proteins has had a marked impact on the study of their localization and function in the healthy and diseased kidney. Electroneutral cation-chloride cotransporters [Na(K)CC] have been localized to the thick ascending limb and the distal convoluted tubule using specific probes. Proteins implicated in the function of aldosterone target cells, such as the epithelial Na⁺ channel (ENaC), the mineralocorticoid receptor (MR) and 11β-hydroxysteroid dehydrogenase type 2 (11HSD2), an enzyme that confers mineralocorticoid specificity, have been found in the terminal portion of the nephron and the collecting duct. A mineralocorticoid-sensitive component of thiazide-sensitive NaCl transport has been identified in the distal convoluted tubule. Analysis of the ontogeny of these proteins in the maturing kidney has provided a detailed picture of epithelial differentiation and morphological specialization of the renal tubule. The study of mutations of the proteins related with NaCl transport has led to the identification of the molecular causes of inherited human diseases associated with hypo- or hypertension, and the respective sites of an impaired ion transport could be mapped to the renal tubule. Accepted: 13 April 1999     

Expression of tumor necrosis factor receptors in normal kidney and rejecting renal transplants.

Activation of the TNF signal transduction cascade is initiated by the interaction of TNF with either of two cell surface receptors, TNFR-1 and TNFR-2. The levels and regulation of expression of these two receptors has been extensively analyzed in cultured cells, but little is known of TNFR expression in situ. We analyzed the expression of TNFR-1 and -2 in normal human renal kidney and in renal transplants undergoing acute cellular rejection. Immunohistochemistry and immunogold electron microscopy indicated a strong expression of TNFR-1 on the endothelium of glomeruli of normal kidney. Immunogold colocalization for TNFR-1 and a marker of the trans-Golgi network (TGN-46) demonstrated TNFR-1 within the Golgi complex in endothelial cells in normal kidney, confirming our previous studies with cultured cells. TNFR-1 expression was lost in glomeruli from acutely rejecting kidney, but TNFR-1 was detected in abundance on infiltrating leukocytes in the interstitium of allografts with acute rejection. In contrast, TNFR-2 was demonstrated predominantly in epithelial cells of distal convoluted tubule (DCT) in acute rejection kidney near TNF-expressing leukocytes. TNF was absent in normal kidney, but present in rejecting allograft. TNF was found in infiltrating leukocytes and in adjacent tubular epithelial cells. In situ hybridization showed TNFR-1 mRNA within the endothelium of the glomeruli and of a few arterioles in normal kidney, whereas TNFR-2 mRNA was seen in tubular epithelial cells of the DCT in acute transplant rejection. These data reveal that there is both differential expression and regulation of the two TNF receptors in human kidney.     

Sustained cell proliferation of renal epithelial cells in mice with inv mutation

A tubule system is an important component of the nephron, which is the structural and functional unit of the kidney. Expansion of renal tubules results in renal cysts. Hereditary forms of renal cystic diseases suggest that tubular size is determined genetically. The inv was discovered as a mutant with renal cysts and situs inversus. Inv/inv, inv deltaC::GFP (inv deltaC) mouse was created by the introduction of the inv gene lacking the C-terminus (inv deltaC) into inv/inv mice. The mouse develops multiple renal cysts without situs abnormality, giving us an opportunity to study inv function in renal tubular structure maintenance. In the present study, we showed that inv suppresses cyst progression in a dose-dependent manner and that the inv deltaC cystic kidneys showed increased cell proliferation and apoptosis. Cell cycle regulators for G1-S progression were activated in the cystic kidney. Furthermore, cDNA microarray and semiquantitative RT-PCR analysis showed that growth-related genes maintained a high level of expression in the cystic kidney at 4 weeks of age whereas they were decreased in control kidneys, suggesting that cells in inv deltaC kidney are still active in the cell cycle. One of the inv protein functions may provide a stop signal for renal epithelial cell proliferation.