Novel standards in the measurement of rat insulin granules combining electron microscopy, high-content image analysis and in silico modelling.
Novel standards in the measurement of rat insulin granules combining electron microscopy, high-content image analysis and in silico modelling.
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DOI：
10.1007/s00125-011-2438-4
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发表时间：
2012-04
期刊：
影响因子：
8.2
通讯作者：
Solimena, M.
中科院分区：
文献类型：
--
作者：
Fava, E.;Dehghany, J.;Ouwendijk, J.;Mueller, A.;Niederlein, A.;Verkade, P.;Meyer-Hermann, M.;Solimena, M.
关键词：
了解胰岛素分泌颗粒的数量、大小和含量是了解胰腺β细胞生理学的关键。在这里，我们重新评估了大鼠β细胞的关键结构特征，包括胰岛素颗粒大小、数量和分布以及细胞大小。使用高含量分析方法比较了化学或高压冷冻固定的大鼠β细胞的电子显微镜照片。这些数据用于开发三维计算机β细胞模型，其切片将再现实验数据集。如前所述，化学固定的胰岛素分泌颗粒呈空心球，平均直径为350 nm。值得注意的是，大多数高压冷冻固定的颗粒缺乏致密的核心和限制膜之间的特征晕，并小于其化学固定的同行。根据我们的分析，我们得出结论，大鼠胰岛素分泌颗粒的平均直径为243 nm，相当于0.19 μm2的表面积。大鼠β细胞的平均体积为763 μm3，含有5，000 - 6，000个颗粒。相对于先前的解释，平均颗粒数/大鼠β细胞较低的主要原因是平均β细胞体积的估计值降低。这些发现意味着每个颗粒含有大约两倍多的胰岛素，而其胞吐作用增加的膜电容比以前假设的少两倍。我们的综合方法定义了β细胞定量图像分析的新标准，并可应用于其他细胞系统。本文的在线版本（doi：10.1007/s 00125 -011-2438-4）包含同行评审但未经编辑的补充材料，可供授权用户使用。
Knowledge of number, size and content of insulin secretory granules is pivotal for understanding the physiology of pancreatic beta cells. Here we re-evaluated key structural features of rat beta cells, including insulin granule size, number and distribution as well as cell size. Electron micrographs of rat beta cells fixed either chemically or by high-pressure freezing were compared using a high-content analysis approach. These data were used to develop three-dimensional in silico beta cell models, the slicing of which would reproduce the experimental datasets. As previously reported, chemically fixed insulin secretory granules appeared as hollow spheres with a mean diameter of ∼350 nm. Remarkably, most granules fixed by high-pressure freezing lacked the characteristic halo between the dense core and the limiting membrane and were smaller than their chemically fixed counterparts. Based on our analyses, we conclude that the mean diameter of rat insulin secretory granules is 243 nm, corresponding to a surface area of 0.19 μm2. Rat beta cells have a mean volume of 763 μm3 and contain 5,000–6,000 granules. A major reason for the lower mean granule number/rat beta cell relative to previous accounts is a reduced estimation of the mean beta cell volume. These findings imply that each granule contains about twofold more insulin, while its exocytosis increases membrane capacitance about twofold less than assumed previously. Our integrated approach defines new standards for quantitative image analysis of beta cells and could be applied to other cellular systems. The online version of this article (doi:10.1007/s00125-011-2438-4) contains peer-reviewed but unedited supplementary material, which is available to authorised users.
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影响因子：
21.3
作者：
Knoch, KP;Bergert, H;Solimena, M
通讯作者：
Solimena, M
影响因子：
4.1
作者：
GRANT, PT;FRANK, BH;COOMBS, TL
通讯作者：
COOMBS, TL
DOI：
10.1073/pnas.92.21.9608
发表时间：
1995-10-10
影响因子：
11.1
作者：
HUANG, L;SHEN, H;KENNEDY, RT
通讯作者：
KENNEDY, RT
影响因子：
5.5
作者：
Göpel, S;Kanno, T;Rorsman, P
通讯作者：
Rorsman, P
影响因子：
4.8
作者：
Leung, YM;Ahmed, I;Gaisano, HY
通讯作者：
Gaisano, HY