PKG Regulation of Sirtuin 1 as a Novel Treatment Strategy for Age-related Osteoporosis

Sirtuin 1 的 PKG 调节作为年龄相关性骨质疏松症的新型治疗策略

• 批准号: 10296605
• 负责人: RENATE B PILZ
• 金额: $ 46.71万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-05 至 2026-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10296605
• 关键词: Affect; Age; Age-Related Osteoporosis; Aging; American; Antioxidants; Apoptosis; Architecture; Bone Resorption; Cell Aging; Clinical Trials; Cyclic AMP-Dependent Protein Kinases; Cyclic GMP; Cyclic GMP-Dependent Protein Kinases; DNA Damage; Deacetylase; Disease; Effectiveness; FDA approved; Feedback; Foundations; Fracture; Fright; G-substrate; Gene Expression Profile; Genes; Genetic; Genetic Transcription; Goals; Guanylate Cyclase; Impairment; Insulin-Dependent Diabetes Mellitus; Knock-out; Knockout Mice; Knowledge; Lead; Longevity; Mediating; Mesenchymal Stem Cells; Messenger RNA; Metabolic; Minority; Mitochondria; Mus; NOS3 gene; Nitric Oxide; Nitric Oxide Donors; Nitric Oxide Synthase; Nuclear; Osteoblasts; Osteoclasts; Osteocytes; Osteogenesis; Osteoporosis; Osteoporotic; Oxidative Stress; Pain; Patients; Pharmaceutical Preparations; Pharmacology; Phosphorylation; Physicians; Proteins; RNA-Binding Proteins; Regulation; Ribonucleoproteins; Role; SIRT1 gene; Signal Pathway; Signal Transduction; Testing; Transgenic Organisms; Wild Type Mouse; Woman; Work; age related; aged; analog; base; beta catenin; bone; bone loss; bone mass; bone strength; cobinamide; diabetic; improved; interest; mRNA Expression; male; men; mitochondrial dysfunction; mortality; neutralizing antibody; nicotinamide-beta-riboside; novel; novel therapeutics; osteoblast differentiation; osteoporosis with pathological fracture; overexpression; prevent; protein activation; protein expression; public health relevance; senescence; side effect; skeletal; treatment strategy

SUMMARY Age-related osteoporosis affects millions of American men and women, and is a major cause of fractures in those over age 50. Bone loss is due mainly to impaired bone formation, but FDA-approved agents with bone- anabolic effects (PTH analogs and the sclerostin-neutralizing antibody romosozumab) have serious limitations. We have found that pharmacologic or genetic stimulation of the NO/cGMP/protein kinase G (PKG) signaling pathway enhances bone formation and prevents bone loss in diabetic and aged mice; the mechanism is through increased Wnt/β-catenin signaling and reduced oxidative stress. Silent information regulator T1 (Sirtuin1, SIRT1) and its substrate NAD+ decrease with age, contributing to many age-related diseases, including osteoporosis. Osteoblast-specific Sirt1 knockout mice are osteoporotic while Sirt1 overexpressing mice have high bone mass. We found recently that PKG activation increases SIRT1 expression in osteoblasts, mesenchymal stem cells (MSCs), and bones of aged mice by stabilizing Sirt1 mRNA; the RNA binding protein hnRNPA1 is required. SIRT1 is known to increase NO synthesis, possibly leading to a positive feedback loop with PKG. Supporting positive feedback between PKG and SIRT1, we found they synergistically increase pro-survival genes in osteoblasts and prevent oxidative stress-induced apoptosis. As part of our interest in NO/cGMP/PKG signaling, we have developed nitrosyl-cobinamide (NO-Cbi), a NO donor that is also a strong anti-oxidant. Recent work shows that a 10 week course of NO-Cbi improved bone formation, architecture, and strength in 24 month-old mice. The overall goal of the proposed studies is to define the interactions between PKG and SIRT1 in bone, and devise a novel treatment strategy for age-related osteoporosis based on PKG and SIRT1 activators. In Aim 1 we will define how PKG increases Sirt1 mRNA in MSCs and osteoblasts, focusing on PKG regulation of hnRNPA1. In Aim 2, we will determine the consequences of PKG-SIRT1 crosstalk in bones of aged mice. We will determine whether PKG requires SIRT1 to improve bone formation and strength by examining the effects of PKG-activating agents on bone in conditional osteoblast-specific Sirt1 knockout mice. To determine if SIRT1- induced NO synthesis and PKG activation is necessary for the positive effects of SIRT1 activators in bone, we will examine the skeletal effects of these agents in mice with conditional deletion of Prkg2 in osteoblasts. In Aim 3, we will test whether combining PKG- and SIRT1-activating agents can synergistically increase bone formation in aged mice, compared to each treatment alone. We will use NO-Cbi and the guanylyl cyclase activator cinaciguat to activate PKG, and direct SIRT1 activators and nicotinamide riboside, a NAD+ precursor, to activate SIRT1. The proposed work will fill important knowledge gaps, defining the role of PKG-SIRT1 crosstalk in bone during aging and determining how PKG-SIRT1 reduce age-related oxidative stress in bone; importantly, the proposed work lays the foundation for developing novel bone-anabolic therapies for age-related osteoporosis.

概括 与年龄相关的骨质疏松症影响着数百万美国男性和女性，并且是导致骨折的主要原因。 50 岁以上的人。骨质流失主要是由于骨形成受损，但 FDA 批准的药物具有骨- 合成代谢作用（PTH 类似物和硬化素中和抗体 romosozumab）具有严重的局限性。 我们发现 NO/cGMP/蛋白激酶 G (PKG) 信号传导的药理或遗传刺激 途径增强糖尿病小鼠和老年小鼠的骨形成并防止骨质流失；该机制是通过 增加 Wnt/β-连环蛋白信号传导并减少氧化应激。沉默信息调节器T1（Sirtuin1、SIRT1） 其底物NAD+随着年龄的增长而减少，导致许多与年龄相关的疾病，包括骨质疏松症。 成骨细胞特异性 Sirt1 敲除小鼠患有骨质疏松症，而 Sirt1 过表达小鼠则具有高骨量。 我们最近发现 PKG 激活会增加成骨细胞、间充质干细胞中 SIRT1 的表达 (MSC)，以及通过稳定 Sirt1 mRNA 来修复老年小鼠的骨骼；需要 RNA 结合蛋白 hnRNPA1。 SIRT1 已知可增加 NO 合成，可能导致与 PKG 的正反馈循环。配套 PKG 和 SIRT1 之间的正反馈，我们发现它们协同增加了促生存基因 成骨细胞并防止氧化应激诱导的细胞凋亡。作为我们对 NO/cGMP/PKG 信号传导感兴趣的一部分， 我们开发了亚硝酰基钴酰胺 (NO-Cbi)，它是一种 NO 供体，也是一种强抗氧化剂。最近的工作 显示 10 周的 NO-Cbi 疗程改善了 24 个月大的骨形成、结构和强度 老鼠。拟议研究的总体目标是确定 PKG 和 SIRT1 在骨骼中的相互作用， 并设计一种基于 PKG 和 SIRT1 激活剂的年龄相关骨质疏松症的新型治疗策略。瞄准 1 我们将定义 PKG 如何增加 MSC 和成骨细胞中的 Sirt1 mRNA，重点关注 PKG 对 hnRNPA1。在目标 2 中，我们将确定 PKG-SIRT1 串扰对老年小鼠骨骼的影响。我们 将通过检查以下因素的影响来确定 PKG 是否需要 SIRT1 来改善骨形成和强度 条件性成骨细胞特异性 Sirt1 敲除小鼠骨上的 PKG 激活剂。确定 SIRT1- 诱导 NO 合成和 PKG 激活对于 SIRT1 激活剂在骨中的积极作用是必要的，我们 将检查这些药物对成骨细胞中条件性删除 Prkg2 的小鼠的骨骼影响。瞄准 3、我们将测试结合PKG-和SIRT1-激活剂是否可以协同增加骨形成 在老年小鼠中，与单独治疗相比。我们将使用 NO-Cbi 和鸟苷酸环化酶激活剂 cinaciguat 激活 PKG，并指导 SIRT1 激活剂和烟酰胺核苷（NAD+ 前体）激活 SIRT1。拟议的工作将填补重要的知识空白，定义 PKG-SIRT1 串扰在骨中的作用 衰老过程中并确定 PKG-SIRT1 如何减少骨骼中与年龄相关的氧化应激；重要的是， 拟议的工作为开发针对年龄相关骨质疏松症的新型骨合成代谢疗法奠定了基础。