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 几乎所有关节损伤的一半导致有症状的创伤后骨关节炎（PTOA）在5年内 受伤。关节的超生理机械加载，例如因运动伤害或事故而发生的， 据信被驻留在关节软骨内的软骨细胞机械地感知 分解代谢和炎症基因表达的级联反应以及蛋白酶和细胞因子的合成，这些因子和细胞因子的合成 加速有症状的PTOA中存在的软骨降解。尽管有广泛的特征 PTOA中存在的骨关节炎软骨细胞，软骨细胞所感知的机制超过 机械负荷以及将损伤机械与分解代谢基因表达联系起来的途径尚不清楚。 目前，尚无疾病改变骨关节炎药物（DMOADS）来治疗，预防或延迟 受伤后软骨的降解。最近发现的压电通道（Piezo1和Piezo2）是 第一类离子通道直接响应哺乳动物的机械刺激。我们的实验室发现 压电通道选择性地将高细胞变形转换为细胞内信号，这表明一种新颖的 超生理负荷可以直接启动并传播分解代谢基因的机制 PTOA的表达。基本问题仍然围绕着压电激活在 软骨细胞对机械负荷的反应，包括：细胞变形的阈值激活 压电通道以及在三维环境中如何看待这种变形？孤立和 确定软骨细胞机械转导的变形模式将是我们的主要进步 了解细胞机械转导和软骨的生理学。另外，对 机械激活的压电通道的基因表达尚不清楚。总体而言，该提议试图 建立软骨细胞中压电通道的机械激活的基本模式 压电激活的下游含义。具体而言，在AIM 1中，我们将确定细胞变形 驱动压电激活的阈值以及如何加载仿生三维水凝胶系统引起 软骨细胞压电激活。然后，AIM 2将确定压电在机械激活基因上的作用 表达。共同完成这些令人兴奋的目标将通过协调的实验来实现 和计算方法。这笔赠款的资金将为我提供多学科的体验 我在组织工程中对软骨细胞机械生物学和的计算培训和实验培训 基因调节。