Transduction of Substrate Mechanical Cues via Piezo1 Ion Channels

该奖项将促进我们对细胞如何感知和反应来自环境的各种机械输入的基本理解。细胞利用来自细胞外基质（ECM）、粘附分子和局部硬度的局部环境线索来做出关于生长和运动的决定。在ECM处将机械刺激转化为电能的过程通常被认为通过粘附蛋白如整合素起作用。对压电离子通道的新兴研究表明，这些通道也可以对基底机械性能的变化做出反应。因此，这些通道可以用作附加的力传感器。这项工作将探讨一种新的细胞传感器，称为Piezo 1，在检测ECM力的作用。这些结果最终可能会影响人类健康。例如，身体对这些机械信号的错误处理会导致各种疾病，包括慢性肾病和癌症。这项工作的结果可能会导致这些条件的新类型的治疗。 该结果具有广泛适用的潜力，因为Piezo 1存在于许多细胞类型和器官中，其中机械环境在正常功能中起着重要作用。研究结果将通过实验教育（E2 E）平台整合到外展活动中，该平台涉及研究生，本科生和当地高中生。该项目基于Piezo 1是上皮细胞中主要的力传感器的假设，它检测转化为膜张力的基底机械线索。这是通过前馈机制发生的：局部张力激活Piezo 1通道和钙内流，从而刺激钙依赖性收缩和细胞伸展;细胞几何形状的变化反过来又促进更多的Piezo 1活性和Piezo 1迁移到应力区域，导致同一方向的进一步生长。这一假设将与基板调制作为机械刺激，FRET为基础的荧光探针报告开放转换Piezo 1，和伤口愈合试验，以屏幕细胞的流动性进行测试。有三个主要目标。首先，通过抑制Piezo 1活性和敲低Piezo 1来识别细胞中的ECM力传感器。第二，研究基板如何改变Piezo 1响应可视化的位置和开放的通道在细胞重塑。第三，验证功能性Piezo 1表达水平决定引导集体细胞迁移的领导细胞的身份的假设。总之，这项工作的结果有可能改变我们对影响上皮细胞的各种疾病状态的机制的理解。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This award will advance our fundamental understanding of how cells sense and react to diverse mechanical inputs from their environments. Cells utilize local environmental cues from the extracellular matrix (ECM), adhesive molecules, and local stiffness to make decisions about growth and movement. The process of converting mechanical stimulus to electrical energy at the ECM is commonly thought to act via adhesion proteins such as integrins. Emerging research on Piezo ion channels reveals that these channels can also respond to changes in the substrate mechanical properties. Therefore, these channels may serve as additional force sensors. This work will explore the role of a novel cell sensor, called Piezo1, in detecting ECM forces. The results may ultimately impact on human health. For example, the body’s mishandling of these mechanical signals results in a variety of diseases, including chronic kidney disease and cancer. The results of this work may lead to new types of treatment for these conditions. The outcome has the potential to be broadly applicable, since Piezo1 is found in many cell types and organs where the mechanical environment plays a major role in proper function. The research findings will be integrated into outreach activities through an Education through Experimentation (E2E) platform that involves graduate, undergraduate, and local high school students in this project.The project is based on the hypothesis that Piezo1 is the primary force sensor in epithelial cells, and that it detects the substrate mechanical cues translated into membrane tension. This occurs through a feedforward mechanism: local tension activates Piezo1 channels and calcium influx, which stimulates calcium-dependent contractility and cell spreading; the changes in cell geometry in turn, promote more Piezo1 activity and the migration of Piezo1 to regions under stress, causing further growth in the same direction. This hypothesis will be tested with substrate modulation as mechanical stimulus, a FRET-based fluorescent probe to report opening transitions in Piezo1, and a wound healing assay to screen cell mobility. There are three primary objectives. First, to identify ECM force sensors in cells by inhibiting Piezo1 activity and by knockdown of Piezo1. Second, to investigate how substrates alter Piezo1 responsiveness by visualizing the location and opening of channels during cell reshaping. Third, to test the hypothesis that functional Piezo1 expression level determines the identity of leader cells guiding collective cell migration. Taken together, the results of this work have the potential to transform our understanding of the mechanisms of various disease states that affect epithelial cells.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.