Nanoscale protein architecture of the kidney glomerular basement membrane.
Nanoscale protein architecture of the kidney glomerular basement membrane.
复制标题
作者：
Suleiman H;Zhang L;Roth R;Heuser JE;Miner JH;Shaw AS;Dani A
在多细胞生物体中，细胞外基质（ECM）的蛋白质在基本上所有器官中发挥结构和功能作用，因此了解健康和疾病中的ECM蛋白质组织仍然是一个重要目标。在这里，我们使用亚衍射分辨率随机光学重建显微镜（STORM），以解决在原位的肾小球基底膜（GBM），肾小球超滤的重要介质内的蛋白质的分子组织。使用多通道STORM和STORM-电子显微镜相关性，我们构建了一个分子参考框架，揭示了GBM内ECM蛋白的层状组织。在小鼠和人GBM中，对聚集蛋白、层粘连蛋白和IV型胶原蛋白的N-和C-末端附近的结构域的单独分析揭示了高度定向的大分子组织。我们的分析还揭示了Alport综合征小鼠模型中GBM结构的破坏。这些结果提供了第一个纳米级的一瞥到组织的复杂ECM。DOI：http://dx.doi.org/10.7554/eLife.01149.001流经身体的血液必须不断过滤，以去除废物，并确保它含有最佳水平的水和盐。过滤是在肾脏内由一簇叫做肾小球的小血管完成的。这些肾小球毛细血管允许水和废物从血液进入尿液，同时阻止蛋白质和血细胞。肾小球毛细血管壁由两层细胞组成，第三层细胞位于肾小球基底膜的两侧。如果这些层中的任何一层出现故障，蛋白质就有可能进入尿液。这是肾脏疾病的明显迹象。基底膜由两层细胞分泌的蛋白质组成，但对这些蛋白质的组织方式知之甚少。现在，Suleiman等人已经采用了一种新形式的高分辨率光学显微镜，称为STORM，以研究小鼠和人类肾脏组织中肾小球基底膜的结构。通过结合STORM和电子显微镜的数据，Suleiman等人表明，两种物种肾小球基底膜中的蛋白质排列相似，形成了独特的分层结构。这表明基底膜的组织在其功能中起着关键作用。该技术被用来证明蛋白质在从患有Alport综合征（一种肾脏遗传性疾病）的小鼠中采集的组织样本中的肾小球基底膜中没有组织化。除了表明基底膜的解体可能在疾病中起重要作用外，这项工作还提供了一种研究不同类型组织中基底膜结构的方法。DOI：http://dx.doi.org/10.7554/eLife.01149.002网站
In multicellular organisms, proteins of the extracellular matrix (ECM) play structural and functional roles in essentially all organs, so understanding ECM protein organization in health and disease remains an important goal. Here, we used sub-diffraction resolution stochastic optical reconstruction microscopy (STORM) to resolve the in situ molecular organization of proteins within the kidney glomerular basement membrane (GBM), an essential mediator of glomerular ultrafiltration. Using multichannel STORM and STORM-electron microscopy correlation, we constructed a molecular reference frame that revealed a laminar organization of ECM proteins within the GBM. Separate analyses of domains near the N- and C-termini of agrin, laminin, and collagen IV in mouse and human GBM revealed a highly oriented macromolecular organization. Our analysis also revealed disruptions in this GBM architecture in a mouse model of Alport syndrome. These results provide the first nanoscopic glimpse into the organization of a complex ECM. DOI: http://dx.doi.org/10.7554/eLife.01149.001 The blood that flows through the body must be continually filtered to remove waste products and to ensure that it contains optimal levels of water and salts. Filtration is performed inside the kidneys by tufts of small blood vessels called glomeruli. These glomerular capillaries allow water and waste products to pass from the blood into the urine, while holding back proteins and blood cells. The wall of a glomerular capillary consists of two layers of cells flanking a third layer called the glomerular basement membrane. If any of these layers malfunctions, it becomes possible for proteins to pass into the urine. This is a clear sign of kidney disease. The basement membrane is composed of proteins secreted by the two layers of cells, but little was known about how these proteins are organized. Now, Suleiman et al. have adapted a new form of high-resolution optical microscopy called STORM to study the structure of the glomerular basement membrane in both mouse and human kidney tissue. By combining data from STORM and electron microscopy, Suleiman et al. showed that the proteins in the glomerular basement membranes of both species are arranged similarly to form a distinctive layered structure. This suggests that the organization of the basement membrane plays a critical role in its function. The technique was used to demonstrate that proteins were not organized in the glomerular basement membrane in tissue samples taken from mice suffering from Alport syndrome, a genetic disorder of the kidneys. In addition to suggesting that the disorganization of basement membranes may play an important role in disease, this work also provides a method for investigating the structure of the basement membrane in diverse types of tissue. DOI: http://dx.doi.org/10.7554/eLife.01149.002