Novel Strategies for Understanding and Treating Fibrous Dysplasia

理解和治疗纤维发育不良的新策略

• 批准号: 10658595
• 负责人: EDWARD C HSIAO
• 金额: $ 69.96万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-01 至 2028-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10658595
• 关键词: Acceleration; Address; Affect; Artificial Intelligence; Automobile Driving; Binding; Biological Assay; Biological Markers; Biology; Bone Diseases; Bone Growth; Bone callus; Calvaria; Cells; Clinical; Complex; Cre driver; Cyclic AMP; DNA Sequence Alteration; Data; Disease; Dysplasia; Foundations; Fracture; Functional disorder; Future; G Protein-Coupled Receptor Signaling; G-Protein-Coupled Receptors; GNAS gene; GTP-Binding Protein alpha Subunits, Gs; Gene Expression Profile; Genes; Genetic; Health; Hematopoietic stem cells; Homeostasis; Human; Hybrids; Hyperactivity; Individual; Institution; Isoproterenol; Kinetics; Knowledge; Lead; Lesion; Ligands; McCune-Albright Syndrome; Mediating; Medical; Modeling; Molecular; Molecular Probes; Mus; Musculoskeletal Diseases; Mutation; Natural regeneration; Osteitis Fibrosa Disseminata; Osteoblasts; Osteocytes; Osteogenesis; Osteoporosis; PTH gene; Pathology; Pathway interactions; Patients; Phenotype; Physiology; Production; Property; Proteins; Public Health; Recombinants; Role; Sampling; Signal Pathway; Signal Transduction; Signaling Molecule; Testing; Therapeutic; Variant; WNT Signaling Pathway; WNT4 gene; WNT9A gene; Wnt proteins; Work; analytical method; bone; bone cell; bone fracture repair; bone loss; bone repair; bone turnover; cell type; computational intelligence; digital; effective therapy; experience; genetic approach; guanine nucleotide binding protein; improved; in vivo evaluation; induced pluripotent stem cell; mouse model; novel; novel strategies; novel therapeutic intervention; novel therapeutics; osteogenic; overexpression; parathyroid hormone-related protein; pharmacologic; prevent; rare condition; receptor; repaired; single-cell RNA sequencing; skeletal; skeletal stem cell; stem cell function; stem cell model; therapeutic target; tool; transcriptome; transcriptomics; treatment strategy

PROJECT SUMMARY Current treatments for many musculoskeletal disorders are often suboptimal. Understanding the signals controlling skeletal homeostasis and repair is of high relevance, since this knowledge is critical for developing effective therapies for common conditions such as osteoporosis and fractures. In this proposal, we study fibrous dysplasia (FD) as a way to understand the regulators of human bone formation, and test if these pathways could then be used to enhance bone repair. FD accounts for 2.5% of all bone lesions and can occur as part of McCune-Albright Syndrome (MAS). FD is caused by genetic mutations in the GNAS locus, leading to a constitutively active Gs-GPCR protein, hence increasing cAMP levels and causing aberrant cellular signaling. Medical treatments for this disfiguring disorder are sorely lacking. This proposal uses new tools, including mouse models, human induced pluripotent stem cells (iPSCs), skeletal stem/progenitor cells, and advanced genetic strategies, to address the critical knowledge gaps and to find novel therapies for these medically significant conditions. We propose three specific aims: Aim 1: Identify novel compounds that directly target Gsα-regulated cAMP and Wnt production. We previously showed that stopping excess Gs-GPCR pathway activity in mice could dramatically reverse FD-like bone lesions. Using a new artificial intelligence computational approach, we found 71 candidate compounds predicted to selectively bind the GsαR201H protein. Preliminary studies demonstrate that some of these show the desired inhibition of GsαR201H-induced basal cAMP production. This Aim takes our top candidates and further characterizes their ability to block cAMP and Wnt activity, as potential molecular tools for manipulating GNAS. We also test if the lead compounds can reverse existing FD lesions in mouse calvarial cultures. Aim 2: Test if Wnt inhibition can prevent FD bone lesions in mice. How the GNAS mutations in FD cause dramatic bone formation is still poorly defined. We recently found that three proteins, Wnt4, Wnt5a, and Wnt9a, are upregulated in both mouse and human FD bone lesions. This Aim tests if blocking these proteins can reverse FD bone lesions in mice, and examines how each Wnt protein impacts FD lesion pathology. Aim 3: Determine the pathways that are dysregulated in human FD bone lesions and assess the roles of WNT signaling in human skeletal stem/progenitor cells during fracture repair. This aim uses advanced genetics on human FD bone samples to identify the malfunctioning cell types that cause FD. We also test how overactivating WNT4, WNT5a, or WNT9a in human skeletal stem/progenitor cells affect bone formation in a fracture healing model. These results will identify new targets for treating FD and for promoting fracture healing. This application address key knowledge gaps about which Wnt signaling molecules drive FD and how they impact human osteogenesis. The proposal comes from an established, strong, collaborative, multi-institutional team with extensive experience in GPCRs, FD, bone biology, and bone analytical methods. 1

项目概要 目前对许多肌肉骨骼疾病的治疗通常不是最理想的。了解信号 控制骨骼稳态和修复具有很高的相关性，因为这些知识对于发育至关重要 针对骨质疏松症和骨折等常见疾病的有效疗法。 在本提案中，我们研究纤维发育不良（FD）作为了解人类骨形成调节因子的一种方式， 并测试这些途径是否可以用于增强骨修复。 FD 占所有骨病变的 2.5% 可能是麦库尼-奥尔布赖特综合症 (MAS) 的一部分。 FD 是由 GNAS 基因突变引起的 位点，导致组成型活性 Gs-GPCR 蛋白，从而增加 cAMP 水平并导致异常 细胞信号传导。对于这种毁容性疾病的药物治疗非常缺乏。本提案使用新 工具，包括小鼠模型、人类诱导多能干细胞 (iPSC)、骨骼干/祖细胞、 和先进的遗传策略，以解决关键的知识差距并找到针对这些问题的新疗法 具有医学意义的情况。我们提出三个具体目标： 目标 1：鉴定直接靶向 Gsα 调节的 cAMP 和 Wnt 产生的新型化合物。我们 先前表明，停止小鼠体内过量的 Gs-GPCR 通路活性可以显着逆转 FD 样 骨病变。使用新的人工智能计算方法，我们发现了 71 种候选化合物 预测选择性结合 GsαR201H 蛋白。初步研究表明，其中一些研究表明 期望抑制 GsαR201H 诱导的基础 cAMP 产生。这个目标让我们的顶尖候选人进一步 表征了它们阻断 cAMP 和 Wnt 活性的能力，作为操纵 GNAS 的潜在分子工具。 我们还测试了先导化合物是否可以逆转小鼠颅骨培养物中现有的 FD 损伤。 目标 2：测试 Wnt 抑制是否可以预防小鼠 FD 骨损伤。 GNAS 突变如何导致 FD 剧烈的骨形成仍然不明确。我们最近发现三种蛋白质，Wnt4、Wnt5a 和 Wnt9a， 在小鼠和人类 FD 骨损伤中均上调。该目标测试阻断这些蛋白质是否可以逆转 小鼠的 FD 骨病变，并检查每种 Wnt 蛋白如何影响 FD 病变病理。 目标 3：确定人类 FD 骨病变中失调的途径并评估其作用 骨折修复过程中人类骨骼干/祖细胞中的 WNT 信号传导。该目标采用先进的 对人类 FD 骨骼样本进行遗传学分析，以识别导致 FD 的故障细胞类型。我们还测试了如何 人骨骼干细胞/祖细胞中过度激活 WNT4、WNT5a 或 WNT9a 会影响骨形成 骨折愈合模型。这些结果将确定治疗 FD 和促进骨折愈合的新目标。 该应用解决了关于哪些 Wnt 信号分子驱动 FD 以及它们如何驱动 FD 的关键知识差距 影响人体成骨。该提案来自一个成熟的、强大的、协作的、多机构的 团队在 GPCR、FD、骨生物学和骨分析方法方面拥有丰富的经验。 1