Mechanistic and Therapeutic Studies of Initiation and Expansion for Genetic and Acquired Heterotopic Ossification

遗传性和获得性异位骨化的起始和扩展的机制和治疗研究

• 批准号: 10834605
• 负责人: Qian Cong
• 金额: $ 7.55万
• 依托单位: HARVARD MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-11 至 2024-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10834605
• 关键词: Affect; Automobile Driving; Binding; Bone Development; Bone Diseases; Cell Differentiation process; Clinical; Complication; Data; Defect; Development; Disease; Ectopic Expression; Embryonic Development; Erinaceidae; Event; Family; Feedback; GTP-Binding Protein alpha Subunits, Gs; Genetic; Genetic Diseases; Genetic Transcription; Goals; Heterotopic Ossification; Human; In Vitro; Injury; Joints; Knowledge; Lead; Lesion; Ligands; Medical; Mesenchymal; Modeling; Molecular; Motion; Mus; Online Mendelian Inheritance In Man; Operative Surgical Procedures; Osteoblasts; Osteogenesis; Outcome; Pathogenesis; Pathologic; Patients; Play; Population; Probability; Progressive osseous heteroplasia; Promoter Regions; Puncture procedure; ROR1 gene; Recurrence; Regulation; Role; SHH gene; Sampling; Signal Transduction; Skeletal bone; Surgical complication; Tendon structure; Testing; Therapeutic Studies; Trauma; Traumatic injury; Up-Regulation; achilles tendon; acquired heterotopic ossification; beta catenin; bone; cartilage development; cell motility; cell type; chronic pain; cost; effective therapy; human disease; in vivo Model; insight; long bone; migration; mouse model; new therapeutic target; novel; null mutation; osteoblast differentiation; progressive myositis ossificans; rare genetic disorder; receptor; recruit; response; skeletal; soft tissue; stem cell proliferation; stem cells; therapeutic target; therapeutically effective; transcription factor

Project Summary/Abstract Heterotopic ossification (HO) refers to extraskeletal pathological bone formation that occurs as a common complication after injury or as a manifestation of particular genetic disorders. However, limited by poor understanding of the underlying cellular and molecular mechanisms, there is currently no effective treatment and surgical eviction often results in recurrence. The overall goal of the project is to investigate cellular and molecular mechanisms underlying HO initiation and expansion and identify potential treatment targets for genetic and acquired HO. Our preliminary data suggests that in mouse models of progressive osseous heteroplasia (POH), a human disease caused by null mutations in GNAS that encodes Gαs, progressive expansion of ectopic bone was due to recruitment of surrounding wild-type cells. Mechanistically, Gnas-/- mesenchymal cells differentiate into osteoblasts and recruit wild-type cells to form bone by activating YAP, a transcription factor that regulates expression of Sonic hedgehog (Shh), which encodes a secreted ligand in the Hh family. Secreted SHH further induces YAP activation, thereby resulting in additional Shh expression and osteoblast differentiation in surrounding wild type cells. In human samples with acquired HO, upregulated YAP and HH signaling were also found, indicating the clinical importance of our findings. In our unpublished preliminary studies, we found upregulated Wnt5a expression in Gnas-/- SMPs in vitro and in HO lesions of POH mouse models in vivo. WNT5a not only regulates stem cell proliferation and enhances repopulation, but also plays an essential role in long bone and cartilage development during embryogenesis. Importantly, we found that Wnt5a expression was also controlled by YAP activation and was required for HO in both genetic and acquired HO. These findings lead to a central hypothesis that YAP and WNT5a are activated in a positive feedback loop to recruit progenitor cells for osteoblast differentiation in soft tissues, thereby promoting HO formation in both genetic and acquired HO mouse models. We will test these hypotheses in three aims. The first aim is to clarify the relationship between YAP and Wnt5a expression in ectopic bone formation in POH and test whether YAP and WNT5a interact in a positive feedback loop. The second aim is to illuminate the molecular mechanism in response to YAP and WNT5a in ectopic bone formation. The third aim is to investigate the contribution of WNT5a to ectopic bone formation in fibrodysplasia ossificans progressiva (FOP) and trauma-induced HO models. Taken together, these proposed studies will yield novel insights into a common cellular and molecular mechanism underlying initiation and expansion of distinct HO forms and highlight the importance of rare genetic disease studies in identifying a shared core pathological mechanism underlying a class of diseases.

项目概要/摘要 异位骨化（HO）是指骨骼外病理性骨形成，作为一种常见的现象发生。 受伤后的并发症或作为特定遗传性疾病的表现。但受限于贫困 由于对潜在的细胞和分子机制的了解，目前尚无有效的治疗方法和 手术切除常常导致复发。该项目的总体目标是研究细胞和分子 HO 启动和扩展的机制，并确定遗传和疾病的潜在治疗靶点 收购了HO。我们的初步数据表明，在进行性骨异型增生（POH）的小鼠模型中， 一种由编码 Gαs 的 GNAS 无效突变引起的人类疾病，异位骨进行性扩张 这是由于周围野生型细胞的募集。从机制上讲，Gnas-/- 间充质细胞分化 进入成骨细胞并通过激活 YAP（一种调节转录因子）招募野生型细胞形成骨骼 音刺猬 (Shh) 的表达，编码 Hh 家族中的分泌配体。进一步分泌SHH 诱导 YAP 激活，从而导致额外的 Shh 表达和成骨细胞分化 周围的野生型细胞。在具有获得性 HO 的人类样本中，YAP 和 HH 信号也上调 发现，表明我们的发现的临床重要性。在我们未发表的初步研究中，我们发现 体外 Gnas-/- SMP 和体内 POH 小鼠模型的 HO 损伤中 Wnt5a 表达上调。 WNT5a 不仅调节干细胞增殖和增强再生，而且在长骨中发挥重要作用 和胚胎发生过程中的软骨发育。重要的是，我们发现 Wnt5a 表达也 受 YAP 激活控制，并且是遗传性和获得性 HO 中 HO 所必需的。这些发现导致 一个中心假设是，YAP 和 WNT5a 在正反馈循环中被激活，以招募祖细胞 软组织中的成骨细胞分化，从而促进遗传性和获得性 HO 小鼠中 HO 的形成 模型。我们将在三个目标上检验这些假设。第一个目的是澄清YAP和YAP之间的关系 POH异位骨形成中Wnt5a的表达并测试YAP和WNT5a是否正相互作用 反馈循环。第二个目标是阐明 YAP 和 WNT5a 响应的分子机制 异位骨形成。第三个目的是研究 WNT5a 对异位骨形成的贡献 进行性骨化性纤维发育不良 (FOP) 和创伤诱导的 HO 模型。综合起来，这些建议 研究将对共同的细胞和分子机制产生新的见解，这些机制是启动和 扩展不同的 HO 形式并强调罕见遗传病研究在识别罕见遗传病方面的重要性 一类疾病的共同核心病理机制。