Deconstructing Cartilage Mechanotransduction by Piezo Channels

通过压电通道解构软骨机械传导

基本信息

批准号：
10666726
负责人：
Farshid Guilak
金额：
$ 7.43万
依托单位：
WASHINGTON UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-06-02 至 2025-07-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10666726
关键词：
ATF2 gene Address Affect Age Age-Years Aging Animals Anti-Inflammatory Agents Attenuated Binding Biochemical Body Weight Cartilage Cartilage injury Cell membrane Cell model Cells Chondrocytes Complex Coxibs Degenerative polyarthritis Dependence Development Disease Dynamin Economics Electrophysiology (science)Elements Environment Exposure to Family suidae Friction Gene Expression Gene Expression Regulation Genetic Transcription Grant HNF4A gene Health Human Hypersensitivity Inflammation Inflammatory Injury Interferons Interleukin-1 alpha Ion Channel Joints Life Link Mechanical Stress Mechanics Mediating Metabolic Methods Modeling Morphology Mus Non-Steroidal Anti-Inflammatory Agents Obesity Pain Pathogenesis Pathologic Pathway interactions Pharmaceutical Preparations Phenotype Physiological Piezo 1 ion channel Piezo 2 ion channel Piezo ion channels Population Prevalence Process Public Health Regulatory Pathway Role Signal Transduction Social isolation Societies Structure Surface Synovial joint Testing Time Trauma United States anakinra antagonist arthropathies articular cartilage attenuation biological adaptation to stress cytokine disability experimental study frailty human disease human old age (65+)in vivo inhibitor insight joint injury joint loading loss of function mechanical force mechanical properties mechanical signal mechanotransduction meloxicam osteochondral tissue promoter radiological imaging response response to injury skeletal socioeconomics synergism trafficking transcription factor translational therapeutics voltage

项目摘要

Osteoarthritis (OA) is painful and debilitating by affecting the synovial joints, and is found in over 12% of the total United States population 25-74 years of age. The prevalence of OA increases significantly with age, with radiographic evidence in over 70% of the population over age 65. In this growing segment of our society, OA is a significant contributor to disability, frailty and social isolation. Despite the tremendous socioeconomic impact of OA, there are no disease-modifying therapies available. OA is distinctively characterized by the progressive, degenerative changes in the morphology, composition, and mechanical properties of articular cartilage. Mechanotransduction in articular chondrocytes is a key component of disease pathogenesis, given the link between direct sensing of the cells’ mechanical environment and the resulting metabolic imbalance of cartilage in OA. We have recently identified the mechanosensitive PIEZO ion channels - in fact a synergy between PIEZO1 and PIEZO2, both expressed in articular cartilage - to underlie chondrocyte mechanotransduction in response to injurious mechanical stress. The overall objective of this study is to define the mechanisms of Piezo-mediated mechanotransduction in chondrocytes more in-depth so that these insights can be leveraged toward the development of disease- modifying approaches in joint-loading-induced injuries, including OA. In addition to our recent discovery of chondrocytic Piezo-mediated mechanotransduction, we found that treatment of chondrocytes with pathophysiologically-relevant concentrations of IL-1α, a pro-inflammatory cytokine, increased Piezo1 gene expression, and that increased expression of Piezo1 was also present in osteoarthritic cartilage from aging pigs and humans. Thus, the Specific Aims of this grant are: (1) to determine the mechanisms of synergistic functioning of Piezo1/2 in chondrocyte mechanotransduction; (2) to deconstruct Piezo-mediated mechanotransduction in chondrocytes under inflammatory conditions; (3) to elucidate the role of Piezo- mediated mechanotransduction in organotypic cartilage explants and in-vivo. Aim 1 will rely on cellular studies. We will explore synergisms of Piezo1/2 at the levels of electrophysiology, channel trafficking, finite element modeling, and ultra-structure, the latter also examining human cartilage from OA vs controls. In Aim 2 primary porcine chondrocytes will be stimulated with IL-1α for deconstruction of Piezo-mediated mechanotransduction. Aim 3 will rely on porcine osteochondral explants and chondrocyte-specific and inducible Piezo1/2-/- mice which we have generated. Various modes of mechanical stress will be applied to cells, explants, and animals, and loss-of-function studies of Piezo-mediated mechanotransduction will be conducted with both mechanistic intent and translational/therapeutic direction. The proposed Aims will extend our initial discovery with mechanistic in- depth studies that will increase our understanding of OA in a non-incremental manner, and this will inspire the development of new Disease-Modifying OA Drugs (DMOADs).

骨关节炎 (OA) 通过影响滑膜关节而导致疼痛和衰弱，超过 12% 的患者患有骨关节炎 (OA)。 25-74 岁的美国总人口 OA 患病率随着年龄的增长而显着增加。超过 70% 的 65 岁以上人口中有放射线证据。在我们社会这个不断增长的群体中，骨关节炎尽管产生了巨大的社会影响，但它是造成残疾、虚弱和社会孤立的一个重要因素。对于 OA，尚无可用的疾病缓解疗法 OA 的显着特点是进行性、进展性。关节软骨的形态、成分和机械性能发生退行性变化。鉴于以下联系，关节软骨细胞的机械转导是疾病发病机制的关键组成部分直接感知细胞的机械环境与由此产生的软骨代谢失衡之间的关系在 OA 领域，我们最近发现了机械敏感的 PIEZO 离子通道 - 实际上是两者之间的协同作用。 PIEZO1 和 PIEZO2，均在关节软骨中表达 - 是软骨细胞机械转导的基础对有害机械应力的反应。本研究的总体目标是确定压电介导的机械转导的机制更深入地研究软骨细胞，以便可以利用这些见解来促进疾病的发展除了我们最近的发现之外，还修改了关节负荷引起的损伤（包括 OA）的治疗方法。软骨细胞压电介导的机械转导，我们发现用 IL-1α（一种促炎细胞因子）的病理生理学相关浓度增加，Piezo1 基因增加表达，并且 Piezo1 表达增加也存在于衰老引起的骨关节炎软骨中因此，这项资助的具体目标是：（1）确定协同机制。 (2) 解构压电介导炎症条件下软骨细胞的机械转导；（3）阐明压电的作用；器官型软骨外植体和体内介导的机械转导将依赖于细胞研究。我们将在电生理学、通道运输、有限元等层面探索 Piezo1/2 的协同作用建模和超微结构，后者还检查 OA 与对照组的人类软骨。将用 IL-1α 刺激猪软骨细胞，以解构压电介导的机械转导。目标 3 将依赖猪骨软骨外植体和软骨细胞特异性和可诱导的 Piezo1/2-/- 小鼠，我们已经产生了各种模式的机械应力将应用于细胞、外植体和动物，并且压电介导的机械转导的功能丧失研究将以两种机械意图进行以及转化/治疗方向。拟议的目标将通过机械原理扩展我们的初步发现。深入的研究将以非渐进的方式增加我们对 OA 的理解，这将启发开发新的缓解 OA 疾病药物 (DMOAD)。