Vascular cell-to-cell communication during remodeling

描述（由申请人提供）：该项目的总体目标是了解细胞间通讯在血管重塑中的作用。重塑是一个重要的过程，它既是有益的（例如，运动训练时动脉的扩大），也是病理的(例如：如高血压期间的动脉狭窄)，细胞间通讯在这一过程中所起的作用尚不清楚。细胞间的通讯通过间隙连接发生，间隙连接连接相邻细胞的内部，并允许对刺激的协调反应。这种沟通对于动脉和血管发育的协调收缩/舒张是重要的，因此可能参与血管细胞在重塑过程中的协调。该项目的具体目标是了解改变的流量对细胞间通讯和构成间隙连接的蛋白质表达的影响。血流改变是血管重构的主要刺激因素，血流增加促进血管管腔扩大，血流减少促进血管管腔狭窄。利用培养的血管模型，在维持管腔压力和组织环境的同时，测量细胞间通讯的早期变化（24、48小时）（通过评估传导的血管舒张反应和内皮源性超极化因子引起的血管舒张来评估）和间隙连接蛋白表达（通过免疫组织化学和定量PCR来评估）。在结扎手术后8天，将在臀大肌体内测量长期增加的血流对这些参数的影响，结扎手术可促进侧支动脉血流增加和重塑。血管功能将通过活体显微镜评估，使用带有荧光血管的转基因小鼠（即内皮细胞表达绿色荧光蛋白）来有效测量血管直径的反应。由于血管重塑是血管满足组织代谢需求的重要过程，了解细胞在此过程中的沟通能力将有助于深入了解重塑过程和对血流的反应。细胞间通讯减少与血管功能障碍有关，这是动脉粥样硬化的主要组成部分。关于血管细胞间的通讯是如何被调节的，我们知之甚少，了解一种主要的物理力量，如血流，是如何影响这种重要的血管功能的，是很重要的。

DESCRIPTION (provided by applicant): The overall goal of this project is to understand the role of cell-to-cell communication in vascular remodeling. Remodeling is an important process that is both beneficial (e.g., enlargement of arteries during exercise training) and pathological,(e.g., narrowing of arteries during hypertension), and it is unknown what role cell- to-cell communication plays in this process. Cell-to-cell communication occurs through gap junctions that link the interiors of neighboring cells and allows coordinated responses to stimuli. This communication is important for coordinated contraction/relaxation of arteries and vascular development, and thus is likely to be involved in the coordination of vascular cells during remodeling. The specific goal of this project is to understand the effect of altered flow on cell-to-cell communication and expression of the proteins that constitute gap junctions. Altered flow is a primary stimulus for vascular remodeling, where increased flow promotes vessel lumen enlargement and decreased flow promotes narrowing. Using a cultured vessel model, early changes (24, 48 hrs) in cell-to-cell communication (assessed by evaluating conducted vasomotor responses, and vasodilation due to endothelium-derived hyperpolarizing factor) and gap junction protein expression (assessed by immunohistochemistry and quantitative PCR) will be measured in response to decreased or increased flow through the vessel lumen, while maintaining lumen pressure and tissue environment. The effects of chronically increased flow on these parameters will also be measured in vivo in gluteus maximus muscle 8 d after ligation surgery, which promotes increased flow and remodeling in collateral arteries. Vessel function will be assessed by intravital microscopy using transgenic mice with fluorescent vessels (i.e., endothelial cells express green fluorescent protein) to effectively measure vessel diameter responses. Because vascular remodeling is an important process for allowing blood vessels to meet the metabolic demands of tissues, understanding the ability of cells to communicate during this process will provide insight into the remodeling process and response to flow. Decreased cell-to-cell communication has been linked to vascular dysfunction, which is a major component of atherosclerosis. Little is known about how vascular cell-to-cell communication is regulated, and it is important to understand how a major physical force, such as flow, affects this important vascular function.