KLF4 in joint degradation and regeneration

KLF4 在关节降解和再生中的作用

• 批准号: 10166750
• 负责人: Martin K Lotz
• 金额: $ 45.39万
• 依托单位: SCRIPPS RESEARCH INSTITUTE, THE
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-30 至 2023-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10166750
• 关键词: Affect; Aging; Apoptosis; Attenuated; Biological; Cartilage; Cartilage Matrix; Cell Culture Techniques; Cell Death; Cells; ChIP-seq; Chondrocytes; Degenerative polyarthritis; Enzymes; Equilibrium; Family; Gene Delivery; Gene Expression; Genes; Growth Factor; Histones; Homeostasis; Human; Interleukin-1; Joints; Knockout Mice; Lead; Maintenance; Medical; Modeling; Molecular; Mus; Natural regeneration; Organ; Outcome; Pain; Palliative Care; Pathogenesis; Pathologic; Patients; Regulation; Role; Severities; Signal Transduction; Testing; Tissues; Transgenic Mice; aged; aggrecan; arthropathies; articular cartilage; cartilage degradation; cytokine; experimental study; joint destruction; knock-down; member; new therapeutic target; novel; novel strategies; overexpression; prevent; protective effect; therapeutic target; tissue culture; transcription factor; transcriptome sequencing

Aging and Osteoarthritis (OA) related changes in joint tissues are in part due to an imbalance in expression of cartilage matrix genes and tissue degradation enzymes in chondrocytes. Elucidation of new molecules and mechanisms responsible for chondrocyte maintenance has potential to advance our understanding of OA pathogenesis and lead to new approaches to prevent or slow tissue damage. Krueppel-like factors (KLF) are transcription factors are involved in various biological and pathological mechanisms, including differentiation, apoptosis, cell reprogramming and tissue/organ homeostasis and protection against aging-related changes; however, their role in cartilage and joint homeostasis has not yet been examined. In preliminary studies we observed a profound reduction in the expression of several KLFs in human OA cartilage and in aged and OA-affected mouse joints. KLF overexpression or knock down in chondrocytes revealed KLF4 as a potent regulator of cartilage matrix genes Col2A1 and aggrecan. KLF4 also attenuated the IL-1 induced expression of catabolic factors These findings support the hypothesis that ‘Aging and OA-related reduction of KLF4 expression is a principal mechanism of tissue destruction and that restoring KLF4 protects against OA.’ Aim 1: Regulation of KLF expression and KLF function in chondrocytes: To investigate mechanisms of KLF4 suppression in OA, we will identify the role of cytokines/growth factors in regulating KLF4 expression. The role of KLF4 in regulating chondrocyte functions will be tested in cell and tissue culture models. Aim 2: The KLF4 signaling network in cartilage: Consequences of KLF4 suppression for signaling and gene expression networks are unknown in cartilage. We will use RNA-seq on cartilage from knock out mice, ChIP- seq and ChIP-seq for histone marks to identify KLF4-regulated target genes and signaling networks. Aim 3: Role of KLF4 in cartilage homeostasis, aging and experimental OA: We will delete KLF4 in mature mice using Acan-CreERT and examine mice for aging-related changes and severity of experimental OA. Aim 4: Protective effects of KLF4 overexpression and activation: Potential protective effects of KLF4 will be tested using novel transgenic mice that overexpress KLF4 in cartilage to balance the OA-associated KLF suppression and we will determine outcomes with respect to homeostasis mechanisms and OA severity. The potential impact of the proposed studies is that they will be the first to determine the role of KLF4 in cartilage homeostasis and the consequences of KLF4 suppression for joint aging and OA pathogenesis. We will also establish proof of concept for KLF4 as a therapeutic target in OA.

关节组织中衰老和骨关节炎 (OA) 相关的变化部分是由于 软骨细胞中的软骨基质基因和组织降解酶。 负责软骨细胞维持的机制有可能增进我们对 OA 的理解 发病机制并导致预防或减缓组织损伤的新方法。 克鲁佩尔样因子（KLF）是参与多种生物学和病理学的转录因子 机制，包括分化、细胞凋亡、细胞重编程和组织/器官稳态 预防与衰老相关的变化；然而，它们在软骨和关节稳态中的作用尚未明确。 被检查。 在初步研究中，我们观察到人类 OA 中几种 KLF 的表达显着减少 软骨以及老年和 OA 影响的小鼠关节中 KLF 过度表达或软骨细胞中的敲低。 揭示 KLF4 作为软骨基质基因 Col2A1 的有效调节剂，并且 KLF4 也减弱了软骨基质基因 Col2A1 的作用。 IL-1诱导分解代谢因子的表达 这些发现支持这样的假设：“衰老和 OA 相关的 KLF4 表达减少是一个 组织破坏的主要机制，恢复 KLF4 可预防 OA。” 目标 1：软骨细胞中 KLF 表达和 KLF 功能的调节：研究其机制 OA 中的 KLF4 抑制，我们将确定细胞因子/生长因子在调节 KLF4 表达中的作用。 KLF4 在调节软骨细胞功能中的作用将在细胞和组织培养模型中进行测试。 目标 2：软骨中的 KLF4 信号网络：KLF4 信号和基因抑制的后果 软骨中的表达网络是未知的，我们将使用 RNA-seq 来研究基因敲除小鼠的软骨，ChIP- seq 和 ChIP-seq 用于组蛋白标记，以识别 KLF4 调节的靶基因和信号网络。 目标 3：KLF4 在软骨稳态、衰老和实验性 OA 中的作用：我们将在成熟时删除 KLF4 使用 Acan-CreERT 小鼠并检查小鼠的衰老相关变化和实验性 OA 的严重程度。 目标 4：KLF4 过表达和激活的保护作用：KLF4 的潜在保护作用将 使用在软骨中过度表达 KLF4 以平衡 OA 相关 KLF 的新型转基因小鼠进行测试 抑制，我们将确定有关稳态机制和 OA 严重程度的结果。 拟议研究的潜在影响是，它们将是第一个确定 KLF4 在 软骨稳态以及 KLF4 抑制对关节衰老和 OA 发病机制的影响。 还将建立 KLF4 作为 OA 治疗靶点的概念验证。