SIRT6 as a novel therapeutic target in aging and age-related osteoarthritis

SIRT6 作为衰老和年龄相关骨关节炎的新型治疗靶点

基本信息

批准号：
10303788
负责人：
John A Collins
金额：
$ 7.8万
依托单位：
THOMAS JEFFERSON 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：
2021-09-30 至 2023-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10303788
关键词：
Acceleration Affect Age Aging Antioxidants Apoptosis Attenuated Binding Biosensor Cartilage Chondrocytes Chromatin Co-Immunoprecipitations Complex DNA Damage Data Deacetylase Degenerative polyarthritis Development Disease Enzymes Event Functional disorder Future Gene Expression Genes Genetic Transcription Goals Homeostasis Human Hydrogen Peroxide Hypoxia Joints Knock-out Lead Link Longevity MAPK8 gene Maintenance Measures Mediating Metabolic Metabolic dysfunction Metalloproteases Mission Mitogen-Activated Protein Kinases Molecular Mus Nuclear Obese Mice Oxidation-Reduction Oxidative Stress Pathogenesis Pathology Pathway interactions Phosphorylation Phosphotransferases Preventive therapy Process Promoter Regions Proteins Public Health Reactive Oxygen Species Reporter Repression Resistance Reverse Transcriptase Polymerase Chain Reaction Role Sex Differences Signal Pathway Signal Transduction Sirtuins System TXN gene TXNIP gene Therapeutic Intervention Thioredoxin-2 Tissues Woman Work age related aged aggrecanase cartilage degradation catalyst chromatin immunoprecipitation clinical development clinically relevant defined contribution disability experimental study healthspan healthy aging human female human male improved in vivo innovation joint destruction male mouse model new therapeutic target overexpression oxidative damage p38 Mitogen Activated Protein Kinase prevent sex small molecule systemic inflammatory response telomere tool transcription factor

项目摘要

Osteoarthritis (OA) is a leading cause of global disability, and disproportionally affects women. Understanding the precise mechanisms that drive age and sex-specific cartilage degeneration would greatly increase our fundamental understanding of OA pathogenesis and lead to the development of new disease modifying therapies. Recent evidence has identified the nuclear localized deacetylase, sirtuin 6 (SIRT6), as a master regulator of aging processes, in part through promoting resistance to oxidative stress. In mice, SIRT6 overexpression extends lifespan, but only in males, which raises the intriguing possibility that sex specific differences in SIRT6 function could regulate age-associated mechanisms that drive OA. Our preliminary data in chondrocytes demonstrates that SIRT6 activity declines with age, resulting in a significant increase in the levels of the pro-oxidant, thioredoxin (Trx) interacting protein (TXNIP). We propose that increasing levels of TXNIP exacerbate oxidative stress conditions by binding to, and inhibiting, the antioxidant protein, thioredoxin (Trx). A major function of Trx is to suppress catabolic redox signaling events through direct repression of apoptosis signal regulating kinase (ASK1). We have previously shown that ASK1 signaling prevents cartilage degeneration and leads to chondrocyte degeneration and age-associated OA. Thus, our central hypothesis is that aged chondrocytes treated with a SIRT6 activator will be protected from oxidative stress and catabolic signaling events that drive cartilage damage and promote OA. Aim 1 will assess if activation of SIRT6 with the small molecule activator, MDL-800, can mitigate nuclear-specific oxidative stress that will be generated and measured using the innovative NLS-HyPer-DAAO redox biosensor in chondrocytes derived from younger and older cartilage donors. To determine if the effects of SIRT6 are sex-specific, both Aims will use chondrocytes isolated from male and female human chondrocytes. To assess if SIRT6 directly attenuates oxidative stress induced chondrocyte damage, we will assess: 1) redox-related gene transcription, 2) antioxidant levels, 3) DNA damage and telomere dysfunction, and 4) transcription factor activity. Experiments will be conducted under both atmospheric (21%) and hypoxic (2%) conditions to define the contribution of O2 on these processes. In Aim 2, performing the same experiments described in Aim 1, we will determine how SIRT6 activation modulates oxidative stress signaling in chondrocytes through the SIRT6/TXNIP/Trx/ASK1 axis. To assess this, we will examine: 1) TXNIP-Trx and Trx- ASK1 complex formation, 2) ASK1 and MAP kinase activation, 3) gene expression of matrix degrading enzymes. Results from this project will define the specific mechanisms linking chondrocyte aging to OA pathogenesis and may provide significant evidence as to why this disease effects women at a higher rate. It will also provide preliminary data for a future R01 application aimed at determining how SIRT6 activation can be utilized in vivo as a therapy to slow or prevent the progression of OA. Ultimately, we expect this work to catalyze the discovery of new disease-modifying treatments that will reduce the physical hardships associated with age and OA.

骨关节炎（OA）是全球残疾的主要原因，对妇女的影响不成比例。理解推动年龄和性别特异性软骨变性的确切机制将大大增加我们的对OA发病机理的基本了解并导致新疾病的发展疗法。最近的证据已将核局部脱乙酰基酶Sirtuin 6（Sirt6）确定为主人衰老过程的调节剂，部分是通过促进对氧化应激的抗性。在老鼠中，sirt6 过表达延长了寿命，但仅在男性中，这引起了性别特定的有趣可能性 SIRT6功能的差异可以调节驱动OA的年龄相关机制。我们的初步数据软骨细胞表明SIRT6活动随着年龄的增长而下降，导致水平显着增加促氧化剂，硫氧还蛋白（TRX）相互作用蛋白（TXNIP）的含量。我们建议提高TXNIP的水平通过结合并抑制抗氧化剂硫蛋白（TRX）来加剧氧化应激条件。一个 TRX的主要功能是通过直接抑制凋亡信号来抑制分解代谢的氧化还原信号事件调节激酶（Ask1）。我们以前已经表明，Ask1信号传导可防止软骨变性和导致软骨细胞变性和与年龄相关的OA。因此，我们的中心假设是用SIRT6激活剂处理的软骨细胞将受到氧化应激和分解代谢信号事件的保护驱动软骨损坏并促进OA。 AIM 1将评估SIRT6是否用小分子激活激活剂MDL-800可以减轻将使用并测量的核特异性氧化应激软骨细胞中的创新的NLS-HYPER-DAAO氧化还原生物传感器来自年轻和年长的软骨供体。为了确定SIRT6的影响是否特定性别，这两个目标都将使用从男性和雌性人类软骨细胞。评估SIRT6是否直接减弱氧化应激诱导的软骨细胞损坏，我们将评估：1）与氧化还原相关的基因转录，2）抗氧化剂水平，3）DNA损伤和端粒功能障碍和4）转录因子活性。实验将在两个大气下进行（21％）和缺氧（2％）的条件，以定义O2对这些过程的贡献。在AIM 2中，执行相同 AIM 1中描述的实验，我们将确定SIRT6激活如何调节氧化应激信号传导通过SIRT6/TXNIP/TRX/ASK1轴的软骨细胞。为了评估这一点，我们将研究：1）TXNIP-TRX和TRX- Ask1复合形成，2）ASK1和MAP激酶激活，3）基因降解酶的基因表达。该项目的结果将定义将软骨细胞衰老与OA发病机理和可能会提供重要的证据，表明为什么这种疾病以更高的速度影响女性。它也将提供未来R01应用程序的初步数据旨在确定如何在体内使用SIRT6激活作为减慢或防止OA进展的疗法。最终，我们希望这项工作能够催化发现新的改良疾病改良治疗方法将减少与年龄和OA相关的身体困难。