Analysis of dynamics of splenic sinus endothelial cells for controlling of blood cell passage

脾窦的内皮细胞先前已被研究为控制血细胞通过脾索的关键部位。对于内皮功能，响应于体液因子或血液动力学力的游离胞质钙（[Ca^2+]i）的调节是细胞内转导的必要步骤。细胞内Ca^2+是介导多种重要血管内皮细胞功能的第二信使，包括血管活性物质的产生、细胞增殖、基因表达、细胞骨架重塑、细胞收缩和VE-钙粘蛋白的分解，从而增加内皮渗透性。[Ca^2+]i的动员由受体介导的Ca^2+通道、内质网释放的Ca^2+、与瞬时受体电位（TRP）通道密切相关的钙库操纵的钙通道（SOC）以及通过机械敏感性的Ca^2+进入等介导。肌醇-1，4，5-三磷酸受体（I ...更多信息 P_3 R和RyR是调节胞内Ca^2+释放的主要通道，已有报道IP_3 R和RyR与TRP通道偶联。除了肌醇-1，4，5-三磷酸介导的Ca^2+动员和Ca^2+从ryanodine敏感池释放外，通过TRP通道的Ca^2+内流也被认为是内皮细胞Ca^2+信号传导的重要组成部分。用激光共聚焦显微镜和透射电镜观察TRPC 1和CRT在大鼠脾窦内皮细胞信号转导中的作用。此外，检查了大鼠脾窦内皮细胞中VE-钙粘蛋白、β-连环蛋白和p120-连环蛋白的定位，以表征由钙粘蛋白-连环蛋白复合物介导的粘附连接形成的存在和分布，并且在外侧连接膜的不同水平上明显存在免疫标记，并且在窦内皮中间歇性观察到免疫标记。少

Endothelial cells of the splenic sinus have been previously investigated as a critical site for controlling blood cell passage through the splenic cord. For endothelial functionality, modulation of free cytosolic calcium ([Ca^<2+>]i) in response to humoral factors or hemodynamic forces is an essential step of intracellular transduction. Intracellular Ca^<2+> is a second messenger mediating a variety of important vascular endothelial cell functions, including the production of vasoactive substances, cell proliferation, gene expression, cytoskeleton remodelling, cell contraction, and disassembly of VE-cadherin with consequent increase in endothelial permeability. Mobilization of [Ca^<2+>]i is mediated by receptor-mediated Ca^<2+> channels, Ca^<2+> release from endoplasmic reticulum, store-operated calcium channels (SOCs) closely correlated with transient receptor potential (TRP) channels, and Ca^<2+> entry through mechanosensitivity, among others. Inosito-1,4,5-trisphosphate receptors (I … More P_3R) and RyR are the main conduit for the regulated release of Ca^<2+> from intracellular stores, and coupling of IP_3R and RyR to TRP channels has been reported. In addition to inosito-1,4,5-trisphosphate mediated Ca^<2+> mobilization and Ca^<2+> release from ryanodine-sensitive pools, Ca^<2+>-influx through TRP channels has also been suggested to be an important component in endothelial Ca^<2+>-signaling.In the present study, the presence and ultrastructural localization of TRPC1 and the closely associated channels and proteins, IP_3R,RyR,VE-cadherin, and CRT, in the sinus endothelial cells of rat spleen were examined by confocal laser scanning microscopy and transmission electron microscopy to elucidate the role of TRPC1 in signal transduction in sinus endothelial cells. Moreover, the localization of VE-cadherin, β-catenin, and p120-catenin in the rat spleen sinus endothelial cells was examined to characterize the presence and distribution of adherens junction formation mediated by the cadherin-catenin complex and immunolabeling was evident at various levels in the lateral junctional membranes and was intermittently observed in the sinus endothelium. Less