Sawanobori E, Terada N, Fujii Y, Higashida K, Nakazawa S, Ohno S
Department of Pediatrics, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo-shi, Yamanashi, Japan.
Histol Histopathol. 2008 Mar;23(3):297-307. doi: 10.14670/HH-23.297.
Immunoglobulin A (IgA) nephropathy shows great variability regarding the histological features of the lesions of human renal glomeruli. In the present study, the quick-freezing and deep-etching (QF-DE) method was used to analyze the glomerular ultrastructure of biopsied kidney tissues from children with IgA nephropathy. Biopsied renal tissues were routinely prepared for light microscopy, immunofluorescence microscopy, conventional electron microscopy, and replica electron microscopy. The three-dimensional ultrastructure of glomeruli of the kidney was clearly observed by using the QF-DE method. Three layers of glomerular basement membranes, i.e., middle, inner and outer layers, were clearly detected in the replica electron micrographs. The middle layer was 343.0+/-24.2 nm (n=20) in width and formed polygonal meshwork structures. We also observed slit diaphragms, electron-dense mesangial deposits, and increased amounts of mesangial matrix and foot process effacement. Many delicate filaments were found to be distributed from the apical to the bottom portions between neighboring foot processes. The ultrastructural difference between the replica electron micrographs and conventional electron micrographs was found to be especially marked in the appearance of foot processes and connecting filaments between the neighboring foot processes. The examination of extracellular matrix changes, as revealed at high resolution by the QF-DE method, gave us some morphofunctional information relevant to the mechanism of proteinuria with IgA nephropathy.
免疫球蛋白A（IgA）肾病在人类肾小球病变的组织学特征方面表现出很大的变异性。在本研究中，采用快速冷冻和深度蚀刻（QF-DE）方法分析IgA肾病患儿活检肾组织的肾小球超微结构。活检肾组织常规制备用于光学显微镜、免疫荧光显微镜、传统电子显微镜和复型电子显微镜检查。使用QF-DE方法可清晰观察到肾脏肾小球的三维超微结构。在复型电子显微镜照片中清晰检测到三层肾小球基底膜，即中层、内层和外层。中层宽度为343.0±24.2nm（n=20），形成多边形网状结构。我们还观察到裂孔隔膜、电子致密的系膜沉积物、系膜基质增多和足突消失。发现许多纤细的细丝分布在相邻足突之间从顶端到底部的区域。复型电子显微镜照片与传统电子显微镜照片之间的超微结构差异在足突外观和相邻足突之间的连接细丝方面尤为明显。QF-DE方法在高分辨率下揭示的细胞外基质变化检查，为我们提供了一些与IgA肾病蛋白尿机制相关的形态功能信息。
