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.

关节组织的衰老和骨关节炎(OA)相关的改变部分是由于 软骨细胞中的软骨基质基因和组织降解酶。新分子和新分子的阐明 负责软骨细胞维持的机制有可能促进我们对骨关节炎的理解 并导致了预防或减缓组织损伤的新方法。 Krueppel样因子(KLF)是一类转录因子，参与多种生物学和病理过程 机制，包括分化，凋亡，细胞重新编程和组织/器官动态平衡和 对衰老相关变化的保护；然而，它们在软骨和关节动态平衡中的作用尚未 被检查过了。 在初步研究中，我们观察到几种KFL在人类骨性关节炎中的表达显著减少 在软骨和衰老和骨关节炎影响的小鼠关节中。KLF在软骨细胞中的过度表达或下调 发现KLF4是软骨基质基因Col2A1和aggrecan的有效调节因子。KLF4还能减弱小鼠的 IL-1诱导分解代谢因子的表达 这些发现支持这样一种假设：衰老和骨关节炎相关的KLF4表达减少是一种 组织破坏的主要机制和恢复KLF4对OA的保护作用 目的1：调节软骨细胞中KLF的表达和功能：探讨其作用机制 KLF4在骨性关节炎中的抑制，我们将确定细胞因子/生长因子在调节KLF4表达中的作用。这个 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。 目的2：软骨中的KLF4信号网络：抑制KLF4对信号和基因的影响 软骨中的表达网络是未知的。我们将在基因敲除小鼠的软骨上使用RNA-seq，芯片- 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。 目的3：KLF4在软骨内稳、衰老和实验性骨性关节炎中的作用：我们将在成熟期删除KLF4 小鼠使用ACAN-CreERT，并检查小鼠衰老相关的变化和实验性骨关节炎的严重程度。 目的4：KLF4过度表达和激活的保护作用：KLF4 Will的潜在保护作用 使用在软骨中过表达KLF4的新型转基因小鼠进行测试，以平衡OA相关的KLF 抑制和我们将确定关于内稳态机制和骨性关节炎严重程度的结果。 拟议研究的潜在影响是，它们将是第一个确定KLF4在 软骨内稳态和KLF4抑制对关节老化和骨关节炎发病机制的影响。我们 还将为KLF4作为OA的治疗靶点建立概念证明。