Vascular cell-to-cell communication during remodeling

描述(由申请者提供)：本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，既是有益的(例如，运动训练中的动脉扩张)，也是病理性的(例如，高血压期间的动脉狭窄)，目前尚不清楚细胞间的通讯在这一过程中扮演了什么角色。细胞间的通讯通过连接相邻细胞内部的缝隙连接发生，并允许对刺激的协调反应。这种交流对于动脉的协调收缩/松弛和血管的发育是重要的，因此很可能参与了血管细胞在重塑过程中的协调。这个项目的具体目标是了解改变的流量对细胞之间的交流和构成缝隙连接的蛋白质表达的影响。血流改变是血管重塑的主要刺激因素，其中增加的血流促进管腔扩大，减少的血流促进狭窄。利用培养的血管模型，在维持管腔压力和组织环境的同时，将测量细胞间通讯(通过评估传导的血管运动反应和内皮衍生超极化因子引起的血管扩张)和缝隙连接蛋白表达(通过免疫组织化学和定量PCR评估)的早期变化(24、48小时)。慢性血流增加对这些参数的影响也将在结扎手术后8天在臀大肌中进行活体测量，这促进了侧支动脉的血流增加和重塑。血管功能将通过使用带有荧光血管(即内皮细胞表达绿色荧光蛋白)的转基因小鼠的活体显微镜进行评估，以有效地测量血管直径响应。由于血管重塑是使血管满足组织代谢需求的重要过程，了解细胞在这一过程中的沟通能力将有助于深入了解血管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，血管功能障碍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调节的，人们知之甚少，了解一个主要的物理力量，如流动，如何影响这一重要的血管功能是很重要的。

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.