Department of Cell Biology, Fukuoka University School of Medicine, Jonan-ku, Fukuoka, Japan.
Anat Rec (Hoboken). 2010 Dec;293(12):2034-43. doi: 10.1002/ar.21210.
The ultrastructural distribution of vimentin intermediate filaments (IFs) and localizations of the related proteins in sinus endothelial cells of the rat spleen was examined by confocal laser scanning and electron microscopy with detergent extraction, myosin-fragment 1 decoration, and immunogold labeling to elucidate their functions in endothelial cells. Vimentin IFs were extremely abundant over stress fibers in the basal part of the endothelial cells. Some of them were intermingled with actin filaments in stress fibers, and were associated with coated vesicles. Plectin was predominantly localized in the layers of vimentin and stress fibers of the endothelial cells, but rarely in the vicinity of adherens junctions in the lateral part and focal adhesions in the basal part of the cells. Neither plakoglobin nor desmoplakin, which is coupled VE-cadherin to vimentin IFs, was detected in sinus endothelial cells. Vinculin was localized in the basal membranes of the endothelial cells. These data suggest that abundant vimentin IFs are associated with stress fibers by plectin in the basal part of the cells and form cytoskeletal cores of sinus endothelial cells only partially supported by the ring-shaped basal lamina to have roles in scaffolding and the mechanical stabilization of the endothelial cells. Furthermore, taken in connection with recently revealed functions of vimentin and plectin, vimentin might play a cytoskeletal core of sinus endothelial cells.
通过激光共聚焦扫描和电子显微镜检查大鼠脾窦内皮细胞中波形蛋白中间丝（IFs）的超微结构分布以及相关蛋白的定位，以阐明它们在内皮细胞中的功能。波形蛋白 IFs 在基底部分的内皮细胞中的应力纤维上极为丰富。其中一些与应力纤维中的肌球蛋白片段 1 结合，并与有被小泡相关。栓蛋白主要定位于内皮细胞的波形蛋白和应力纤维层，但在细胞侧部的黏着连接和基底部的粘着斑附近很少见。在窦状内皮细胞中未检测到与波形蛋白 IF 偶联的桥粒斑蛋白或桥粒芯胶蛋白。桩蛋白在内皮细胞的基膜上定位。这些数据表明，在细胞的基底部分，丰富的波形蛋白 IFs 通过栓蛋白与应力纤维相关，并形成窦状内皮细胞的细胞骨架核心，仅由环形基底层部分支撑，在支架和内皮细胞的机械稳定中发挥作用。此外，考虑到最近揭示的波形蛋白和栓蛋白的功能，波形蛋白可能在窦状内皮细胞的细胞骨架核心中发挥作用。
