KLF4 in joint degradation and regeneration

KLF4 在关节降解和再生中的作用

• 批准号: 10417083
• 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 2024-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10417083
• 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.

关节组织中与衰老和骨关节炎（OA）相关的变化部分是由于以下因素表达失衡： 软骨细胞中的软骨基质基因和组织降解酶。新分子的阐明和 负责软骨细胞维持的机制有可能促进我们对OA的理解 发病机制，并导致新的方法，以防止或减缓组织损伤。 Krueppel样因子（KLF）是一类转录因子，参与多种生物学和病理学过程 机制，包括分化、凋亡、细胞重编程和组织/器官稳态， 保护免受衰老相关的变化;然而，它们在软骨和关节稳态中的作用还没有 被检查过了 在初步研究中，我们观察到人类OA中几种KLF的表达显著降低， 软骨和老年和OA影响的小鼠关节。软骨细胞中KLF过表达或敲低 揭示了KLF 4作为软骨基质基因Col 2A 1和聚集蛋白聚糖的有效调节剂。KLF 4还减弱了 IL-1诱导分解代谢因子的表达 这些发现支持了这样的假设，即衰老和OA相关的KLF 4表达减少是一个重要因素。 组织破坏的主要机制，恢复KLF 4可以预防OA。 目的1：KLF在软骨细胞中的表达和功能调节：探讨KLF在软骨细胞中的作用机制。 KLF 4在OA中的抑制，我们将确定细胞因子/生长因子在调节KLF 4表达中的作用。的 将在细胞和组织培养模型中测试KLF 4在调节软骨细胞功能中的作用。 目的2：软骨中的KLF 4信号网络：KLF 4抑制对信号和基因的影响 软骨中的表达网络是未知的。我们将使用RNA-seq从敲除小鼠软骨，ChIP- seq和ChIP-seq用于组蛋白标记，以识别KLF 4调节的靶基因和信号网络。 目的3：KLF 4在软骨稳态、衰老和实验性OA中的作用：我们将在成熟的软骨细胞中缺失KLF 4， 使用Acan-CreERT检测小鼠的老化相关变化和实验性OA的严重程度。 目的4：KLF 4过表达和激活的保护作用：KLF 4的潜在保护作用将 使用在软骨中过表达KLF 4的新型转基因小鼠进行测试，以平衡OA相关的KLF 抑制，我们将确定关于稳态机制和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KLF 4在以下方面的作用的研究。 软骨稳态和KLF 4抑制对关节老化和OA发病机制的影响。我们 还将建立KLF 4作为OA治疗靶点的概念验证。