Molecular mechanisms of mechanotransduction in the aqueous outflow pathway

项目摘要/摘要 有大量证据表明，高血压青光眼极大地改变了小梁的容量。 Nethwork(TM)细胞应对机械应力，而机械应力反过来又会导致房水排出障碍 来自前眼的幽默感。功能丧失与TM细胞及其基质的僵硬有关，并与 调节流出通道阻力的稳态机械感受器的损失 经历了房水流动的压力和动态。纤维性重塑是血管紧张性心脏病增加的基础 血流阻力可由慢性眼压升高或由细胞因子转化生长因子引起，后者 在没有机械应力的情况下诱发它。目前还没有概念性的工具来将IOP压力、分期 正常眼和青光眼TM损伤、转化生长因子调控与机械转导的统一性 连贯的机械模型。 这种竞争性更新的目标是测试关于TM细胞如何应对压力的假设， 在青光眼中，这些机制是如何重组的，以及基质僵硬和转化生长因子是如何作用的 通过机械敏感通道作为纤维重塑的触发物，导致心脏功能丧失 青光眼。目标1将确定TRPV4和Piezo1通道在条件性基因敲除中的眼压调节中的作用 常规流出的小鼠模型和体外研究。目的2研究人类免疫缺陷病毒的分子基础。 青光眼TM细胞中异常的机械转导，研究细胞外基质作为中枢的作用 机械敏感性的决定因素，剖析TRPV4基因/蛋白之间的矛盾不协调 表达和功能，并测试关于机械通道参与细胞内应激的假说 信号，收缩，上皮间充质转化和细胞增殖潜能的调节。目标是 目标3是将机械转导和转化生长因子信号结合到一个统一的框架中，从而 导致多种类型青光眼的生物物理(机械)和生化诱因。完工后 在这项研究中，我们希望扩大我们对连锁分子机制的复杂性的理解 通过TM调节流出设施，定义青光眼劫持的分子触发因素 机械敏感离子通道、整合素和细胞骨架的动态力传感和识别 通过恢复细胞自动调节机械反应的能力来减轻损伤的策略。

PROJECT SUMMARY/ABSTRACT There is substantial evidence that hypertensive glaucoma dramatically alters the capacity of trabecular meshwork (TM) cells to cope with mechanical stress, which in turn contributes to impaired drainage of aqueous humor from the anterior eye. Functional loss is associated with stiffening of TM cells and their matrix, and with loss of homeostatic mechanosensing that adjusts the resistance of the outflow pathway to the intensity of experienced pressure and dynamics of aqueous humor flow. Fibrotic remodeling that underlies the increase in flow resistance can be caused by chronic elevations in intraocular pressure (IOP) or by the cytokine TGF which induces it in the absence of mechanical stress. There are currently no conceptual tools to link IOP stress, stages of TM damage, TGF modulation and mechanotransduction in healthy and glaucomatous eyes into a unified coherent mechanistic model. The goal of this competing renewal is to test hypotheses about how TM cells navigate their response to pressure, shear, and strain, how these mechanisms are reorganized in glaucoma and how matrix stiffness and TGF act through mechanosensitive channels to serve as triggers for fibrotic remodeling that leads to functional loss in glaucoma. Aim 1 will establish the roles of TRPV4 and Piezo1 channels in IOP regulation in conditional knockout mouse models and ex vivo studies of conventional outflow. Aim 2 investigates the molecular foundation of abnormal mechanotransduction in glaucomatous TM cells, studies the role of extracellular matrix as a central determinant of mechanosensitivity, dissects the paradoxical dissonance between TRPV4 gene/protein expression and function, and tests hypotheses about involvement of mechanochannels in intracellular stress signaling, contractility, epithelial mesenchymal transition and regulation of cells’ proliferative potential. The goal of Aim 3 is to bring together mechanotransduction and TGF signaling into a unified framework that would accounts for biophysical (mechanical) and biochemical induction of many types of glaucoma. Upon completion of the study we hope to expand our understanding of the complexity of interlocked molecular mechanisms through which the TM regulates outflow facility, define the molecular triggers through which glaucoma hijacks homeostatic force sensing by mechanosensitive ion channels, integrins and the cytoskeleton, and identify strategies to mitigate injury by restoring the cells ability to autoregulate the mechanoresponse.