Ultrastructural analysis of the mechanism of the contraction of splenic sinus endothelial cells

脾窦内皮细胞收缩机制的超微结构分析

基本信息

批准号：
14570032
负责人：
UEHARA Kiyoko
金额：
$ 2.24万
依托单位：
Fukuoka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2003
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14570032/
关键词：
endothelial cells caveolae Ca2+ storing endoplasmic reticulum IP3R ryanodine receptor stress fiber spleen rat カベオラ脾洞内皮細胞 IP_3Rリセプターリアノジンリセプター微細構造

项目摘要

Endothelial cells of the splenic sinus have been previously investigated as a critical site for controlling blood cell passage through the splenic cord, and they have also been shown to be ultrastructurally quite different from other vascular endothelial cells. Particularly prominent are their shape and arrangement, like the staves of a barrel, with a highly ordered network of contractile stress fibers running longitudinally in their basal part. in addition, tubulovesicular structures in close apposition to abundant caveolae and stress fibers are conspicuous. An elevation in intracellular free Ca2+ concentration plays a crucial role in the regulation of endothelial vascular functions and, furthermore, agonists and/or mechanical stress also evoke Ca2+ oscillations. The exact mechanisms contributing to Ca2+ oscillation are unknown, but oscillatory changes in IP3-receptor sensitivity, tune-resolved Ca2+ release from different Ca2+-pools, the rhythmic entry of Ca2+ through non-selective ca … More tion channels, changes in cellular morphology and the involvement of endoplasmic Ca2+-ATPases have been proposed. Considering that the stress **ers in sinus endothelial cells are contracted, caveolae, Ca2+storing ER, IP3R, and RyR in sinus endothelial cells may be involved in the constriction of stress. fibers. in addition, the presence and contribution to Ca2+-oscillations of RyR in endothelial cells have been shown, but the localization in endothelial cells is not quite clear. Therefore, the distribution of caveolac and Ca2+storing ER and the localization of IP3R and RyR in the sinus endothelial cells of the rat spleen were examined by confocal laser scanning and electron microscopy.Immunofluorescence microscopy of tissue cryosections revealed IP3R and RyR to be localized in the subplasmalemmal area and cytoplasm of sinus endothelial cells. By electron microscopy of tissue sections treated with osmium ferricyanide to selectively stain the sarcoplasmic reticulum and transverse tubules in muscle cells, electron-dense tubulovesicular structures were observed to be in close apposition to caveolac and the plasma membrane. Immunogold electron microscopy revealed IP3R and RyR to be present in the tubulovesicular structure in the subplasmalemmal area of sinus endothelial cells. It is speculated that IP3R and RyR in sinus endothelial cells is involved in the constriction of stress fibers. Less

先前已经研究了脾窦的内皮细胞，作为控制血细胞通过脾脏绳的关键部位，并且还显示它们与其他血管内皮细胞有着超大结构的差异。特别突出的是它们的形状和布置，例如枪管的雄鹿，其基本部分纵向运行的收缩应力纤维网络高度有序。另外，密切应用于丰富的小窝和应力纤维的微管结构显着。细胞内游离Ca2+浓度的升高在调节内皮血管功能的调节中起着至关重要的作用，此外，激动剂和/或机械应力也引起CA2+振荡。导致Ca2+振荡的确切机制尚不清楚，但是IP3受体敏感性的振荡变化，从不同的Ca2+池释放的调子分解的Ca2+释放，Ca2+的节奏进入Ca2+通过非选择性CA的节奏进入……更多的tion通道，更多的Endoppop ca2+ s2+ s2+ s2+ s2+ s2+ s2+ s2+ s2+ s2+ eNDOP的变化。考虑到鼻窦内皮细胞中的压力** ers均收缩，Caveolae，Ca2+储存ER，IP3R和RYR中的鼻窦内皮细胞中可能涉及压力的收缩。纤维。此外，已经显示了内皮细胞中RYR的Ca2+振荡的存在和贡献，但是内皮细胞中的定位尚不清楚。 Therefore, the distribution of caveolac and Ca2+storing ER and the localization of IP3R and RyR in the sinus endothelial cells of the rat spleen were examined by confocal laser scanning and electronic microscopy.Immunofluorescence microscopy of tissue cryosections revealed IP3R and RyR to be localized in the subplasmalemmal area and Cytoplasm of sinus endothelial cells.通过用铁氰化物处理的组织切片的电子显微镜检查，在肌肉细胞中选择性染色性肌浆网和横向管的选择性染色，观察到电子致密的管状结构可接近caveolac和质膜。免疫元电子显微镜显示，IP3R和RYR存在于鼻窦内皮细胞的亚质体区域的小管结构中。据推测，鼻窦内皮细胞中的IP3R和RYR参与应力纤维的收缩。较少的