Establishing a new genetic mouse model of osteoarthritis

建立新型骨关节炎基因小鼠模型

• 批准号: 9979381
• 负责人: DAVID J. GRUNWALD
• 金额: $ 22.88万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-11 至 2022-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9979381
• 关键词: Address; Adult; Affect; Aging; Alleles; Amino Acid Substitution; Animal Model; Animals; Arthritis; Biological; Biological Assay; Biological Process; Bone Spur; C57BL/6 Mouse; Candidate Disease Gene; Cartilage; Cells; Code; Degenerative polyarthritis; Development; Disease; Disease Progression; Drug Screening; Etiology; Event; Family; Functional disorder; Future; Gene-Modified; General Population; Genes; Genetic; Goals; Homeostasis; Human; Hyperactive behavior; Immune response; Inbred Strains Mice; Individual; Inflammation; Inflammatory; Inflammatory Response; Injury; Intervention; Invaded; Joints; Knee joint; Link; Maintenance; Measurable; Mechanics; Modeling; Molecular; Mus; Operative Surgical Procedures; Organ; Pain; Pathway interactions; Pattern Recognition; Pattern recognition receptor; Pharmaceutical Preparations; Phosphotransferases; Physiological; Physiology; Predisposition; Process; Production; Proteins; RIPK2 gene; Replacement Arthroplasty; Replacement Therapy; Research; Risk; Role; Sclerosis; Severities; Signal Pathway; Signal Transduction; Study models; Surface; Susceptibility Gene; Testing; Therapeutic Intervention; Tissues; United States; Variant; aged; aging population; base; bone; cartilage degradation; cell type; disability; effective therapy; experience; gain of function; genetic variant; high reward; immunoregulation; joint injury; mouse model; palliative; pre-clinical; precise genome editing; prevent; programs; protein function; receptor; subchondral bone

Osteoarthritis (OA) is the major cause of disability among the aging, affecting more than 30 million adults in the US. It is a painful and debilitating disease involving abnormal remodeling of joint tissues. No cure for OA exists and surgical intervention is the only effective therapy. No known treatment prevents initiation or progression of the disease. Lack of understanding of the genes, molecular pathways, and biological processes underlying susceptibility to OA is the key limitation to the development of effective therapies. As noted in the FOA (16- 240) to which this proposal responds: “little is understood about the initial changes triggering disease etiology and early progression.” Our goal is to identify molecular pathways that are vulnerability points for the development of OA: We first discover human gene variants associated with susceptibility to OA and then determine whether and how these gene variants confer susceptibility to OA in genetically modified mouse models. We predict the pathways perturbed by these alleles are pathways whose normal functions guard against OA. We hypothesize these are the pathways that are eroded or compromised during aging. We have identified four families that harbor strongly supported OA-susceptibility variants in genes encoding components of the NOD-RIPK2 signaling pathway. This pathway uses NOD pattern recognition receptors to sense breakdown products and promote inflammatory signaling that directs tissue homeostasis. We propose modulation of NOD-RIPK2 signaling can contribute to OA susceptibility. In this proposal we test whether a rare RIPK2 variant, which segregates with OA and is hyperactive in signaling, affects normal physiology and/or joint maintenance in mice and is sufficient to confer susceptibility to OA in mice. We generated a precisely modified C57Bl/6 mouse that carries the variant protein-coding allele. In two aims we will test if the variant RIPK2104Asp allele: 1) causes an aberrantly prolonged or sustained inflammatory response; 2) alters maintenance of the joint in naturally aging mice; and 3) enhances the onset and/or severity of OA initiated by mechanical injury to the knee joint. The scientific premise for study of the mouse model is strong. The RIPK2 allele segregates as a highly penetrant dominant factor linked to OA and the OA-associated RIPK2 product has increased signaling activity relative to the wildtype protein. Recently we demonstrated the single amino acid substitution has a measurable effect on the immune response of B6 mice. We hypothesize the RIPK2 variant acts as a gain- of-function allele to over-stimulate the inflammatory response to naturally occurring or induced joint damage. Our studies will determine if the RIPK2 allele is sufficient to increase susceptibility to OA in mice, begin to test the link between the NOD-RIPK2 inflammation pathway and OA, and determine types of initiating events that trigger this pathway. Having a mouse model of an allele linked to a common, idiopathic form of OA will allow us in the future to identify i) specific cell types and biological pathways that are key to vulnerability to OA and ii) additional factors that interact with and exacerbate the effect of RIPK2 signaling on OA.

骨关节炎（OA）是老年人残疾的主要原因，影响了3000多万成年人， 我们它是一种疼痛和衰弱的疾病，涉及关节组织的异常重塑。OA无治愈方法 手术是唯一有效的治疗方法。没有已知的治疗可以阻止 这种疾病缺乏对基因、分子途径和生物学过程的了解 对OA的易感性是开发有效疗法的关键限制。正如《FOA》（16- 240)对此，该提案回应道：“对于引发疾病病因学的初始变化， 早期发展”。我们的目标是确定分子途径，这些途径是 OA的发展：我们首先发现与OA易感性相关的人类基因变异，然后 确定这些基因变异是否以及如何赋予转基因小鼠对OA的易感性 模型我们预测这些等位基因干扰的通路是其正常功能保护的通路。 对抗OA我们假设这些是在衰老过程中被侵蚀或损害的途径。 我们已经确定了四个家族，他们在基因编码中具有强烈支持的OA易感性变体。 NOD-RIPK 2信号通路的组成部分。该途径使用NOD模式识别受体， 感觉分解产物并促进引导组织稳态的炎症信号传导。我们提出 NOD-RIPK 2信号传导的调节可有助于OA易感性。在这个提议中，我们测试一种罕见的 RIPK 2变体与OA分离，在信号传导中过度活跃，影响正常生理和/或关节 在小鼠中维持，并且足以赋予小鼠对OA的易感性。我们生成了一个精确修改过的 携带变体蛋白编码等位基因的C57 B1/6小鼠。在两个目标，我们将测试，如果变异RIPK 2104 Asp 等位基因：1）引起异常延长或持续的炎症反应; 2）改变维持 自然老化小鼠关节;和3）增强由机械损伤引发的OA的发作和/或严重程度， 膝关节。小鼠模型研究的科学前提是强有力的。RIPK 2等位基因作为一种 与OA相关的高渗透性主导因子和OA相关的RIPK 2产物具有增加的信号传导 相对于野生型蛋白的活性。最近，我们证明了单个氨基酸取代具有 对B6小鼠的免疫应答具有可测量的作用。我们假设RIPK 2变体起到了增益的作用- 功能缺失等位基因过度刺激对自然发生或诱导的关节炎性反应 损害我们的研究将确定RIPK 2等位基因是否足以增加小鼠对OA的易感性， 开始测试NOD-RIPK 2炎症通路和OA之间的联系，并确定启动炎症反应的类型。 触发这条路径的事件。具有与常见的特发性OA形式连锁的等位基因的小鼠模型 将使我们在未来能够识别i）特定的细胞类型和生物学途径，这些细胞类型和生物学途径是脆弱性的关键， 和ii）与RIPK 2信号传导对OA的作用相互作用并加剧RIPK 2信号传导对OA的作用的其他因子。