Electron tomography of fiber cell cytoplasm and dense cores of multilamellar bodies from human age-related nuclear cataracts.
Electron tomography of fiber cell cytoplasm and dense cores of multilamellar bodies from human age-related nuclear cataracts.
复制标题
DOI：
10.1016/j.exer.2012.06.005
复制
发表时间：
2012-08
影响因子：
3.4
通讯作者：
Johnsen, Soenke
中科院分区：
文献类型：
--
作者：
Costello, M. Joseph;Burette, Alain;Weber, Mariko;Metlapally, Sangeetha;Gilliland, Kurt O.;Fowler, W. Craig;Mohamed, Ashik;Johnsen, Soenke
关键词：
人类核性白内障的形成是一种多因素疾病，与许多细胞源的光散射有关，这些细胞源在几十年的时间里改变了它们的散射特性。衰老过程产生细胞质结晶蛋白的聚集，改变了细胞质的蛋白质包装和质地。先前对细胞质结构的研究量化了蛋白质堆积过程中密度波动的增加，并从理论上预测了相应的散射。多层体（MLBs）是一种以结晶蛋白细胞质为核心的大颗粒，被认为是人类细胞核散射的主要来源。核心已被证明凝结随着时间的推移，这样的折射率增加相对于邻近的老化和纹理的细胞质。与mlb核心致密的蛋白质堆积相比，本文使用电子断层扫描来观察衰老和白内障晶状体核细胞质中蛋白质聚集体的三维排列。用环氧树脂包埋人透明供体晶状体和核性白内障制备70 nm厚的薄片。以15 nm的金颗粒为基准，在200 kV的FEI T20透射电子显微镜（TEM）上采集了倾斜序列。使用FEI软件对图像进行对齐和校正，并使用IMOD等软件包对图像进行重构，生成动画倾斜序列和立体解析图。蛋白质密度的三维视图显示，在老化的透明晶状体核细胞质中，蛋白质的填充相对均匀，而在老化的白内障细胞质中，蛋白质的填充密度较低，在没有TEM投影伪影的情况下，可以看到许多低密度区域。相比之下，mlb的核心显示出密集的蛋白质包装，密度波动最小。这些观察结果支持这样的结论，即在核性白内障形成过程中，蛋白质填充物的改变是广泛的，并可导致明显的密度波动。老化导致MLB核在蛋白质包装上与邻近细胞质的差异越来越大。这些结果支持了mlb随着年龄和核性白内障形成而增加散射的假设。
Human nuclear cataract formation is a multi-factorial disease with contributions to light scattering from many cellular sources that change their scattering properties over decades. The aging process produces aggregation of cytoplasmic crystallin proteins, which alters the protein packing and texture of the cytoplasm. Previous studies of the cytoplasmic texture quantified increases in density fluctuations in protein packing and theoretically predicted the corresponding scattering. Multilamellar bodies (MLBs) are large particles with a core of crystallin cytoplasm that have been suggested to be major sources of scattering in human nuclei. The core has been shown to condense over time such that the refractive index increases compared to the adjacent aged and textured cytoplasm. Electron tomography is used here to visualize the 3D arrangement of protein aggregates in aged and cataractous lens nuclear cytoplasm compared to the dense protein packing in the cores of MLBs. Thin sections, 70 nm thick, were prepared from epoxy-embedded human transparent donor lenses and nuclear cataracts. Tilt series were collected on an FEI T20 transmission electron microscope (TEM) operated at 200 kV using 15 nm gold particles as fiducial markers. Images were aligned and corrected with FEI software and reconstructed with IMOD and other software packages to produce animated tilt series and stereo anaglyphs. The 3D views of protein density showed the relatively uniform packing of proteins in aged transparent lens nuclear cytoplasm and less dense packing of aged cataractous cytoplasm where many low-density regions can be appreciated in the absence of the TEM projection artifacts. In contrast the cores of the MLBs showed a dense packing of protein with minimal density fluctuations. These observations support the conclusion that, during the nuclear cataract formation, alterations in protein packing are extensive and can result in pronounced density fluctuations. Aging causes the MLB cores to become increasingly different in their protein packing from the adjacent cytoplasm. These results support the hypothesis that the MLBs increase their scattering with age and nuclear cataract formation.
登录
查看更多内容
影响因子：
4.4
作者：
Grey AC;Schey KL
通讯作者：
Schey KL
影响因子：
5.6
作者：
Haley, DA;Horwitz, J;Stewart, PL
通讯作者：
Stewart, PL
影响因子：
3.4
作者：
Costello, M. J.;Johnsen, Soenke;Balasubramanian, Dorairajan
通讯作者：
Balasubramanian, Dorairajan
影响因子：
3.4
作者：
JEDZINIAK, JA;KINOSHITA, JH;BENEDEK, GB
通讯作者：
BENEDEK, GB
影响因子：
4.4
作者：
Costello, M. Joseph;Johnsen, Sonke;Fowler, W. Craig
通讯作者：
Fowler, W. Craig