Department of Molecular and Cellular Anatomy, University of Regensburg, University Street 31, D-93053 Regensburg, Germany.
Ann Biomed Eng. 2010 Jun;38(6):2197-209. doi: 10.1007/s10439-010-0006-6. Epub 2010 Mar 23.
An increasing number of investigations is dealing with the repair of acute and chronic renal failure by the application of stem/progenitor cells. However, accurate data concerning the cell biological mechanisms controlling the process of regeneration are scarce. For that reason new implantation techniques, advanced biomaterials and morphogens supporting regeneration of renal parenchyma are under research. Special focus is directed to structural and functional features of the interface between generating tubules and the surrounding interstitial space. The aim of the present experiments was to investigate structural features of the interstitium during generation of tubules. Stem/progenitor cells were isolated from neonatal rabbit kidney and mounted between layers of a polyester fleece to create an artificial interstitium. Perfusion culture was performed for 13 days in chemically defined Iscove's Modified Dulbecco's Medium containing aldosterone (1 x 10(-7) M) as tubulogenic factor. Recordings of the artificial interstitium in comparison to the developing kidney were performed by morphometric analysis, scanning and transmission electron microscopy. The degree of differentiation was registered by immunohistochemistry. The data reveal that generated tubules are embedded in a complex network of fibers consisting of newly synthesized extracellular matrix proteins. Morphometric analysis further shows that the majority of tubules within the artificial interstitium develops in a surprisingly close distance between 5 and 25 mum to each other. The abundance of synthesized extracellular matrix acts obviously as a spacer keeping generated tubules in distance. For comparison, the same principle of construction is found in the developing parenchyma of the neonatal kidney. Most astonishingly, scanning electron microscopy reveals that the composition of interstitial matrix is not homogeneous but differs along a cortico-medullary axis of proceeding tubule development.
越来越多的研究致力于应用干细胞/祖细胞来修复急性和慢性肾衰竭。然而，关于控制再生过程的细胞生物学机制的准确数据仍然缺乏。因此，新的植入技术、先进的生物材料和促进肾实质再生的形态发生素正在研究中。特别关注的是生成小管和周围间质空间之间界面的结构和功能特征。本实验的目的是研究小管生成过程中间质的结构特征。从新生兔肾中分离出干细胞/祖细胞，并将其置于聚酯绒层之间，以创建人工间质。在含有醛固酮（1 x 10(-7) M）的化学定义的 Iscove's Modified Dulbecco's 培养基中进行灌注培养 13 天，作为小管生成因子。通过形态计量分析、扫描和透射电子显微镜对人工间质与发育中的肾脏进行比较记录。通过免疫组织化学来记录分化程度。数据显示，生成的小管嵌入在由新合成的细胞外基质蛋白组成的复杂纤维网络中。形态计量分析进一步表明，人工间质内的大多数小管彼此之间以惊人的接近距离发育，距离在 5 到 25 微米之间。合成的细胞外基质的丰富度显然起到了间隔的作用，使生成的小管保持一定的距离。相比之下，在新生肾脏的发育实质中也发现了同样的构建原理。最令人惊讶的是，扫描电子显微镜显示，间质基质的组成不是均匀的，而是沿着皮质-髓质的小管发育轴而有所不同。
