FoxO transcription factors in joint aging and osteoarthritis pathogenesis

FoxO转录因子在关节衰老和骨关节炎发病机制中的作用

基本信息

批准号：
9916681
负责人：
Martin K Lotz
金额：
$ 54.14万
依托单位：
SCRIPPS RESEARCH INSTITUTE, THE
依托单位国家：
美国
项目类别：
财政年份：
2018
资助国家：
美国
起止时间：
2018-05-15 至 2023-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9916681
关键词：
Abnormal Cell Affect Aging Apoptosis Autophagocytosis Cartilage Cell Aging Cell Death Cells Cessation of life ChIP-seq Chondrocytes Data Set Degenerative polyarthritis Elements Equilibrium Event Extracellular Matrix Degradation FOXO1A gene FOXO3A gene Failure Foundations Gatekeeping Genes Growth Histones Homeostasis Human Impairment In Vitro Injury Joints Knockout Mice Lead Maintenance Mediator of activation protein Molecular Mus Operative Surgical Procedures Outcome Oxidants Pathogenesis Pathway interactions Pharmacology Prevention approach Process Proteins Regulation Reporting Research Risk Factors Role Severities Severity of illness Signal Transduction Sirolimus Surgical Models Testing Therapeutic Tissues Work age related aged arthropathies articular cartilage base cartilage degradation extracellular in vitro Model knock-down mRNA Expression novel novel strategies overexpression postnatal prevent promoter protective effect protein expression transcription factor transcriptome sequencing

项目摘要

ABSTRACT Osteoarthritis (OA) is the most prevalent joint disease. Although aging represents one of the most important risk factors for OA, mechanisms leading to the aging-related cartilage degeneration remain to be determined. We reported that cellular homeostasis mechanisms such as autophagy and oxidant defenses are compromised in aging and OA-affected cartilage. In our recent studies we investigated FoxO transcription factors, which regulate expression of autophagy proteins and autophagy activation. FoxO3a in particular is known as molecular gatekeeper of cellular aging. We observed a reduction in FoxO mRNA and protein expression in aging and OA-affected cartilage in humans and mice. These findings support the hypothesis that ‘Aging-related reduction of FoxO expression impairs protective cellular homeostasis mechanisms, compromises chondrocyte survival and biosynthetic capacity and leads to accelerated joint aging and initiation of OA pathogenesis’. This hypothesis will be tested in the following aims. Aim 1: Regulation of FoxO expression and function in chondrocytes. We will examine the extracellular regulators and mechanisms of FoxO suppression or activation and identify the responsible cis-elements in the FoxO promoters. Using in vitro models of FoxO knock down and overexpression in normal and OA human chondrocytes and cartilage explants from FoxO deficient mice we will examine the role of FoxO in regulating chondrocyte functions. Aim 2: The FoxO signaling network in cartilage. FoxO target genes are tissue and context specific. We will establish FoxO target genes in mouse cartilage and human chondrocytes by using RNA-seq, ChIP-seq and ChIP-seq for histone marks. Integrative analysis of these datasets will identify pathways and signaling mechanisms that are regulated by FoxO. Aim 3: Role of FoxO in cartilage homeostasis, aging and experimental OA. Our preliminary studies show that conditional cartilage specific deletion of FoxO1 leads to abnormal cartilage growth postnatally and spontaneous OA-like degradation by 6 months. We will generate postnatal triple and single knock out mice using Acan-CreER and test them for aging related changes and severity of experimental OA. Aim 4: Protective effects of FoxO overexpression and activation We will generate mice that overexpress active forms of FoxO1 or FoxO3 in cartilage to balance the OA associated suppression and determine outcomes with respect to homeostasis mechanisms and OA severity in the aging and surgical models. This project will establish that aging-related reduction in FoxO expression is an early and critical event in OA pathogenesis. This will provide the foundation for therapeutic approaches aimed at modulating FoxO expression and/or activity to prevent age-related and injury-induced onset and progression of OA. !

抽象的骨关节炎 (OA) 是最常见的关节疾病，尽管衰老是最重要的关节疾病之一。骨关节炎的危险因素、导致衰老相关软骨退化的机制仍有待确定。我们报道了细胞稳态机制，例如自噬和氧化防御在我们最近的研究中，我们研究了 FoxO 转录。调节自噬蛋白表达和自噬激活的因子尤其是 FoxO3a。被称为细胞衰老的分子守门人我们观察到 FoxO mRNA 和蛋白质的减少。在人类和小鼠的衰老和 OA 影响的软骨中表达。这些发现支持这样的假设：“与衰老相关的 FoxO 表达减少会损害保护性功能”。细胞稳态机制，损害软骨细胞的存活和生物合成能力，并导致加速关节老化和 OA 发病机制的启动”这一假设将在以下目标中得到检验。目标 1：软骨细胞中 FoxO 表达和功能的调节我们将检查细胞外。 FoxO 抑制或激活的调节因子和机制，并确定中负责的顺式元件 FoxO 启动子在正常人和 OA 人类中使用 FoxO 敲低和过度表达的体外模型。来自 FoxO 缺陷小鼠的软骨细胞和软骨外植体，我们将检查 FoxO 在调节中的作用软骨细胞功能。目标 2：软骨中的 FoxO 信号网络是组织和环境特异性的。通过使用RNA-seq、ChIP-seq和在小鼠软骨和人类软骨细胞中建立FoxO靶基因对组蛋白标记进行 ChIP-seq 的综合分析将确定通路和信号传导。 FoxO 调节的机制。目标 3：我们的初步研究表明 FoxO 在软骨稳态、衰老和实验性 OA 中的作用。 FoxO1 的条件性软骨特异性缺失会导致出生后软骨生长异常， 6个月时，我们将产生出生后三重和单重敲除小鼠。使用 Acan-CreER 并测试它们的老化相关变化和实验性 OA 的严重程度。目标 4：FoxO 过度表达和激活的保护作用我们将培育出在软骨中过度表达 FoxO1 或 FoxO3 活性形式的小鼠，以平衡 OA 相关抑制并确定体内平衡机制和 OA 严重程度的结果衰老和手术模型。该项目将确定与衰老相关的 FoxO 表达减少是 OA 的早期且关键事件这将为旨在调节 FoxO 的治疗方法奠定基础。表达和/或活性以预防年龄相关和损伤诱导的 OA 的发作和进展。！