Piezo channel activation and mechanotransduction in chondrocytes during traumatic injury

创伤性损伤期间软骨细胞的压电通道激活和机械转导

• 批准号: 10001969
• 负责人: Robert John Nims
• 金额: $ 7.01万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-01 至 2021-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10001969
• 关键词: 3-Dimensional; Accidents; Acute; American; Anabolism; Apoptosis; Athletic Injuries; Atomic Force Microscopy; Attention; Automobile Driving; Biomimetics; Calcium; Cartilage; Cations; Cell Survival; Cell membrane; Cells; Cellular Mechanotransduction; Cellular Membrane; Chondrocytes; Complex; Degenerative polyarthritis; Disease; Elements; Encapsulated; Environment; Exposure to; Funding; Gene Expression; Gene Expression Regulation; Genes; Grant; Homeostasis; Hydrogels; Hydrostatic Pressure; Inflammatory; Injury; Ion Channel; Knowledge; Link; Mammals; Mechanical Stimulation; Mechanics; Mediating; Mediator of activation protein; Membrane; Modeling; Outcome; Pathway interactions; Patients; Pattern; Peptide Hydrolases; Pharmaceutical Preparations; Pharmacotherapy; Physiological; Physiology; Piezo 1 ion channel; Piezo 2 ion channel; Piezo ion channels; Prevention; Resolution; Role; Secondary to; Sepharose; Signal Transduction; System; Tissue Engineering; Tissues; Training; Traumatic injury; Visualization; Work; articular cartilage; career; cartilage degradation; cytokine; drug development; enzyme biosynthesis; experience; experimental study; fluid flow; joint injury; joint loading; knock-down; mechanical load; mechanotransduction; multidisciplinary; novel; patch clamp; prevent; response; therapy development; transcriptome sequencing

ABSTRACT Nearly half of all joint injuries result in symptomatic post-traumatic osteoarthritis (PTOA) within 5 years of injury. Supraphysiologic mechanical loading of the joint, such as that occurring from a sports injury or accident, is believed to be mechanically perceived by the chondrocytes residing within the articular cartilage, initiating a cascade of catabolic and inflammatory gene expression and the synthesis of proteases and cytokines which accelerate the cartilage degradation present in symptomatic PTOA. Despite the extensive characterization of the osteoarthritic chondrocytes present in PTOA, the mechanisms by which chondrocytes perceive excessive mechanical loading, and the pathways linking injury mechanics to catabolic gene expression, are unknown. Currently there are no disease modifying osteoarthritis drugs (DMOADs) to treat, prevent, or delay the degradation of cartilage following injury. The recently discovered Piezo channels (Piezo1 and Piezo2) are the first class of ion channels directly responsive to mechanical stimulation in mammals. Our lab found that the Piezo channels selectively transduce high cellular deformation into intracellular signals, suggesting a novel mechanism through which supraphysiologic loading may directly initiate and propagate the catabolic gene expression of PTOA. Fundamental questions remain surrounding the role of Piezo activation in the chondrocyte’s response to mechanical loading, including: what threshold for cellular deformation activates the Piezo channels and how is this deformation is perceived in a three-dimensional environment? Isolating and identifying the deformation modes of chondrocyte mechanotransduction would be a major advance in our understanding of cellular mechanotransduction and the physiology of cartilage. Additionally, the influence on gene expression of mechanically-activated Piezo channels is unknown. Overall, this proposal seeks to establish the fundamental modes of mechanical activation of Piezo channels in chondrocytes and the downstream implications of Piezo activation. Specifically, in Aim 1 we will identify the cellular deformation thresholds driving Piezo activation and how loading a biomimetic three-dimensional hydrogel system elicits chondrocyte Piezo activation. Aim 2 will then determine the role of Piezos on mechanically-activated gene expression. Together, completing these exciting aims will be accomplished with a coordinated experimental and computational approach. Funding of this grant will provide me a multidisciplinary experience to advance my computational and experimental training in tissue engineering to that of chondrocyte mechanobiology and gene regulation.

抽象的 近一半的关节损伤会在 5 年内导致有症状的创伤后骨关节炎 (PTOA) 关节的超生理机械负荷，例如运动损伤或事故造成的损伤， 据信，关节软骨内的软骨细胞会机械地感知，从而启动 分解代谢和炎症基因表达的级联以及蛋白酶和细胞因子的合成 尽管有广泛的特征，但加速了有症状的 PTOA 中存在的软骨退化。 PTOA 中存在的骨关节炎软骨细胞，软骨细胞感知过度的机制 机械负荷以及将损伤力学与分解代谢基因表达联系起来的途径尚不清楚。 目前尚无疾病修饰骨关节炎药物 (DMOAD) 可以治疗、预防或延迟骨关节炎的发生 最近发现的压电通道（Piezo1 和 Piezo2）是损伤后软骨的退化。 我们的实验室发现，第一类离子通道直接响应哺乳动物的机械刺激。 压电通道选择性地将高细胞变形转化为细胞内信号，这表明了一种新的 超生理负荷可以直接启动和传播分解代谢基因的机制 PTOA 的表达仍然围绕压电激活的作用。 软骨细胞对机械负荷的反应，包括：细胞变形的阈值激活 压电通道以及如何在三维环境中感知这种变形？ 确定软骨细胞机械转导的变形模式将是我们的重大进步 了解细胞机械传导和软骨的生理学。 总体而言，机械激活压电通道的基因表达尚不清楚。 建立软骨细胞中压电通道机械激活的基本模式和 具体来说，在目标 1 中，我们将识别细胞变形。 驱动压电激活的阈值以及加载仿生三维水凝胶系统如何引发 软骨细胞压电激活然后将确定压电对机械激活基因的作用。 共同完成这些令人兴奋的目标将通过协调一致的实验来完成。 这笔赠款的资助将为我提供多学科的经验来推进。 我在组织工程到软骨细胞力学生物学方面的计算和实验训练以及 基因调控。