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: 10260515
• 负责人: DAVID J. GRUNWALD
• 金额: $ 19.06万
• 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 2023-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10260515
• 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; Hyperactivity; 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) 是导致老年人残疾的主要原因，影响着超过 3000 万成年人。 我们。这是一种痛苦且使人衰弱的疾病，涉及关节组织的异常重塑。 OA 尚无治愈方法 而手术干预是唯一有效的治疗方法。没有已知的治疗方法可以阻止疾病的发生或进展 这种疾病。缺乏对基因、分子途径和生物过程的了解 对 OA 的易感性是有效疗法开发的关键限制。正如 FOA (16- 240），该提案对此回应：“对于引发疾病病因学的最初变化知之甚少 和早期进展。”我们的目标是确定作为脆弱点的分子途径 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。我们预测受这些等位基因干扰的途径是其正常功能保护的途径 反对OA。我们假设这些是在衰老过程中受到侵蚀或损害的途径。 我们已经确定了四个家族，它们在编码基因中含有强烈支持的 OA 易感性变异。 NOD-RIPK2 信号通路的组成部分。该途径使用 NOD 模式识别受体 感知分解产物并促进指导组织稳态的炎症信号传导。我们建议 NOD-RIPK2 信号传导的调节可能导致 OA 易感性。在这个提案中，我们测试是否存在罕见的 RIPK2 变体与 OA 分离并且信号传导过度活跃，影响正常生理和/或关节 小鼠中的维持并足以赋予小鼠对 OA 的易感性。我们生成了一个经过精确修改的 携带变异蛋白编码等位基因的 C57Bl/6 小鼠。我们将在两个目标中测试变体 RIPK2104Asp 是否 等位基因：1) 引起异常延长或持续的炎症反应； 2）改变维护 自然衰老小鼠的关节； 3) 增强机械损伤引发的 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。 RIPK2 等位基因分离为 与 OA 相关的高渗透性主导因子以及 OA 相关的 RIPK2 产物增强了信号传导 相对于野生型蛋白质的活性。最近我们证明了单一氨基酸取代具有 对 B6 小鼠的免疫反应有可测量的影响。我们假设 RIPK2 变体充当增益- 功能失调等位基因过度刺激自然发生或诱导关节的炎症反应 损害。我们的研究将确定 RIPK2 等位基因是否足以增加小鼠对 OA 的易感性， 开始测试 NOD-RIPK2 炎症通路与 OA 之间的联系，并确定起始类型 触发该途径的事件。建立与常见特发性 OA 相关的等位基因小鼠模型 将使我们将来能够确定 i) 易受感染的关键的特定细胞类型和生物途径 OA 和 ii) 与 RIPK2 信号传导对 OA 相互作用并加剧其影响的其他因素。