Validating cGAS-STING pathway as drug target in Huntington disease mouse model

在亨廷顿病小鼠模型中验证 cGAS-STING 通路作为药物靶点

基本信息

批准号：
10508092
负责人：
Srinivasa Subramaniam
金额：
$ 53.13万
依托单位：
UNIVERSITY OF FLORIDA
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-09-20 至 2024-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10508092
关键词：
Address Affect Amyotrophic Lateral Sclerosis Anatomy Animal Diseases Anti-Inflammatory Agents Atrophic Autophagocytosis Behavioral Body Weights and Measures CAG repeat Catabolic Process Cell Culture Techniques Cell model Cells Clinical Trials Code Corpus Callosum Corpus striatum structure Cyclic GMP Data Defect Development Disease Disease Progression Disease model Drug Targeting Etiology Exons Functional disorder Gene Activation Genes Genetic Genetic Transcription Human Huntington Disease Huntington gene Immunohistochemistry Impaired cognition Inflammation Inflammatory Inflammatory Response Knock-in Mouse Knock-out Knockout Mice Knowledge Kynurenine Link Mediating Messenger RNA Microglia Mission Modeling Modification Molecular Monkey Diseases Motor Motor Activity Mus Mutation Natural Immunity Nerve Degeneration Neurodegenerative Disorders Onset of illness Pain Pathogenesis Pathogenicity Pathologic Pathology Pathway interactions Patients Performance Peripheral Persons Pharmaceutical Preparations Pharmacology Phenotype Pre-Clinical Model Public Health Research Research Personnel Ribosomes Role Severity of illness Signal Pathway Signal Transduction Stimulator of Interferon Genes Symptoms Techniques Testing Therapeutic Therapeutic Agents Time Tissue Model Tissues Tryptophan United States National Institutes of Health Walking Western Blotting Work age related base brain tissue chemokine cytokine disability disease phenotype effective therapy experimental study inhibitor insight intraperitoneal monocyte mouse model mutant nervous system disorder novel novel therapeutic intervention polyglutamine pre-clinical prevent response small molecule small molecule inhibitor targeted treatment therapeutic target transcription factor transcriptome sequencing

项目摘要

Project summary Huntington disease (HD) is a fatal neurodegenerative disorder caused by the huntingtin (HTT) CAG expansion mutation (coding for polyglutamine, mHTT). mHTT is a ubiquitously expressed gene, yet it prominently damages the striatum and cortex, followed by widespread peripheral defects as the disease progresses. Prior works have linked innate and adaptive inflammatory responses in HD. Microglia, a cellular indicator of inflammation, is also increased in the striatum of HD animal and cell culture models and HD patients. Increased levels of reactive monocytes, inflammatory cytokines, chemokines, and the n-kynurenine/tryptophan ratio, an indicator of persistent inflammation, have all been observed in pre-manifest HD patients and correlated with HD progression. Furthermore, RNA-seq analysis of tissue obtained from human HD patients and HD monkey models reveals extensive transcriptional dysregulation associated with proinflammatory pathway activation. Inflammation is also closely linked to autophagy, a catabolic process that is dysregulated in HD. Despite these studies, the mechanisms or treatment targets for the reduction of inflammatory responses remain less clear. To fill this knowledge gap, this proposal tests the hypothesis that cyclic GMP–AMP synthase (cGAS)–stimulator of interferon genes (STING), a major innate immunity response pathway, is a disease modifier in HD pathogenesis. This hypothesis was formulated based on our recent finding that the cGAS-STING pathway is upregulated in HD patients’ tissue and cell models and mediates autophagy and inflammatory responses. We found high ribosome occupancy in exon 1 of cGAS mRNA and cGAS-dependent inflammatory transcription factors (Irf3, Irf7), and inflammatory chemokine (Ccl5, and Cxcl10) are upregulated in HD. Depletion of cGAS diminishes downstream effector STING activation and also inhibits autophagy flux in HD cells. The latter is consistent with the primordial function of the cGAS-STING pathway in autophagy induction. These data underline an important role of cGAS-STING signaling in the pathological mechanisms of HD. Subsequently, an independent study confirmed activation of cGAS-STING in HD models. Yet, it is unclear whether the cGAS- STING pathway is a passive or active contributor to HD development. In Aim 1, we will determine whether the genetic deletion of cGAS alters the behavioral and pathological hallmarks of HD KI (z175HD) mice. We will determine age-related behavioral alterations and pathological changes in cGAS–/–;HD KI mice. In Aim 2, we will determine whether the small molecule STING inhibitor diminishes the HD phenotype in HD KI mice. We will treat z175HD mice with the small molecule STING inhibitor, H-151 and determine changes in the HD-like deficits compared vehicle treated z175HD. The proposed experiments will clarify the role of the cGAS–STING pathway as anti-inflammatory therapeutic agents in HD.

项目概要亨廷顿病 (HD) 是一种致命的神经退行性疾病，由亨廷顿蛋白 (HTT) CAG 扩张引起突变（编码聚谷氨酰胺，mHTT）是一种普遍表达的基因，但它会造成显着的损害。纹状体和皮质，随着疾病的进展，随后出现广泛的外周缺陷。小胶质细胞（炎症的细胞指标）也与先天性和适应性炎症反应相关。 HD 动物和细胞培养模型以及 HD 患者纹状体的反应水平增加。单核细胞、炎性细胞因子、趋化因子和 n-犬尿氨酸/色氨酸比率（一个指标）持续性炎症，均在 HD 前期患者中观察到，并与 HD 进展相关。此外，对从人类 HD 患者和 HD 猴子模型获得的组织进行 RNA-seq 分析表明与促炎症通路激活相关的广泛转录失调也是如此。尽管有这些研究，但与自噬密切相关，自噬是一种在 HD 中失调的分解代谢过程。减少炎症反应的机制或治疗目标仍不清楚。为了弥补知识差距，该提案测试了以下假设：环 GMP-AMP 合酶 (cGAS)-刺激物干扰素基因 (STING) 是一种主要的先天免疫反应途径，是 HD 的疾病调节剂这一假设是基于我们最近的发现，即 cGAS-STING 途径是在 HD 患者的组织和细胞模型中上调，并介导自噬和炎症反应。发现 cGAS mRNA 外显子 1 中的高核糖体占据率和 cGAS 依赖性炎症转录 HD 中 cGAS 缺失时，因子（Irf3、Irf7）和炎症趋化因子（Ccl5 和 Cxcl10）上调。减少下游效应器 STING 激活并抑制 HD 细胞中的自噬流。这些数据强调了与 cGAS-STING 通路在自噬诱导中的原始功能一致。 cGAS-STING 信号在 HD 病理机制中发挥重要作用。独立研究证实了 HD 模型中 cGAS-STING 的激活，但尚不清楚 cGAS- 是否有效。在目标 1 中，STING 通路是 HD 发展的被动或主动贡献者。 cGAS 基因缺失会改变 HD KI (z175HD) 小鼠的行为和病理特征。确定 cGAS–/–;HD KI 小鼠与年龄相关的行为改变和病理变化在目标 2 中，我们将。确定小分子 STING 抑制剂是否会减少 HD KI 小鼠的 HD 表型。使用小分子 STING 抑制剂 H-151 的 z175HD 小鼠并确定 HD 样缺陷的变化比较载体处理的 z175HD 所提出的实验将阐明 cGAS-STING 途径的作用。作为 HD 的抗炎治疗剂。