Molecular mechanisms of mechanotransduction in the aqueous outflow pathway

项目总结/摘要 有大量证据表明，眼内压（IOP）的病理性升高在眼内压升高中起因果作用。 小梁网细胞的病理性重塑，其调节房水从眼内的排出， 然而，前眼的机械感测机制的特性和功能在很大程度上仍然未知。 本提案旨在在生物物理、分子和细胞水平上描述这些机制， 以及常规流出的生物工程模型。目标1将建立以下机械阈值： 从无症状和昏迷患者获得人TM细胞，表征机械刺激的作用 应力（压力，拉伸和膨胀）对内在的机械敏感通道，并建立其时间- 依赖特性（急性和慢性适应）。这有望导致一种新的拉伸模型， TM中的稳态基于相反类型的机械敏感性通道的平衡激活。目的2 将压力敏感通道与肌动蛋白细胞骨架的重塑联系起来， 细胞外基质，使用创新的应变敏感光学细胞骨架探针，并定义了功能， 利用仿生纳米支架调节常规流出阻力的机械耦合 由健康的和昏迷的人TM细胞填充。因此，拟议的研究旨在建立 新的概念，实验和翻译框架，将统一我们对视网膜IOP的理解 在机械传导、细胞肿胀、体积感应和钙稳态的背景下的调节， 其目的是引导开发有效的、第一种青光眼治疗方法。

PROJECT SUMMARY/ABSTRACT There is substantial evidence that pathological increases in intraocular pressure (IOP) play a causal role in the pathological remodeling of trabecular meshwork cells which regulate the drainage of aqueous humor from the anterior eye however the identity and function of the mechanosensing mechanisms remains largely unknown. The present proposal aims to characterize these mechanisms at biophysical, molecular and cellular levels as well as in bioengineered models of conventional outflow. Aim 1 will establish the mechanical thresholds of human TM cells obtained from non-symptomatic and glaucomatous patients, characterize effect of mechanical stress (pressure, stretch and swelling) on intrinsic mechanosensitive channels and establish its time- dependent properties (acute & chronic adaptation). This is expected to lead to a novel model of tensile homeostasis in the TM based on balanced activation of opposing types of mechanosensitive channels. Aim 2 links pressure-sensitive channels to the remodeling of actin cytoskeleton and focal adhesion contacts with the extracellular matrix, uses innovative strain-sensitive optical cytoskeleton probes and defines the function of mechanical coupling in the regulation of the conventional outflow resistance using biomimetic nanoscaffolds populated with healthy and glaucomatous human TM cells. The proposed research thus aims to establish novel conceptual, experimental and translational frameworks that will unify our understanding of retinal IOP regulation within the context of mechanotransduction, cell swelling, volume sensing and calcium homeostasis, with the aim to lead towards the development of effective, first-in-kind treatments for glaucoma.