MVNP, p62P392L and IL-6 in the Pathogenesis of PD

MVNP、p62P392L 和 IL-6 在 PD 发病机制中的作用

• 批准号: 8847281
• 负责人: Garson DAVID ROODMAN
• 金额: $ 39.38万
• 依托单位: INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-15 至 2019-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8847281
• 关键词: Abnormal Cell; Affect; American; Area; Bone Pain; Bone Resorption; Bone remodeling; Breeding; Cells; Characteristics; Clinical; Collagen Fiber; Coupled; Coupling; Deformity; Degenerative polyarthritis; Deposition; Development; Environmental Risk Factor; Ephrin-B2; Exhibits; Fracture; GTF2H1 gene; Genes; Genetic; Health; Human; IGF1 gene; Immature Bone; Inherited; Interleukin-6; Lead; Lesion; Link; Measles virus nucleocapsid protein; Mediating; Mus; Mutation; Nerve; Nerve Root Compressions; Osteitis Deformans; Osteoblasts; Osteoclasts; Osteogenesis; Paget' s Disease; Pathogenesis; Patients; Pattern; Phenotype; Plant Roots; Production; Role; Skull Fractures; Testing; Transgenic Mice; Up-Regulation; bone; clinical remission; cranium; in vivo; mouse model; new therapeutic target; novel; osteoblast differentiation; protein expression

DESCRIPTION (provided by applicant): Paget's Disease (PD) is the most exaggerated example of coupled bone remodeling with focal areas of increased bone resorption accompanied by exuberant new bone formation. The excessive new bone formation results in deposition of weak woven bone, which is responsible for many of the clinical sequelae of PD including bone deformity or fracture, skull thickening, bone pain and nerve root compression. Osteoclasts (OCLs) drive the increased bone formation, because treatments targeting OCLs decrease bone resorption and formation. However, the mechanisms responsible for the increased bone formation in PD are unknown. Genetic and environmental factors contribute to development of PD. The most frequent mutations linked to PD are in the SQSTM1/p62 gene, in particular p62P392L. Mice harboring germline p62P394L(p62 mice), the murine equivalent of human p62P392L, exhibit increased OCLs, but do not develop PD. OCLs from 70% of PD patients express the measles virus nucleocapsid protein (MVNP) gene, and transgenic mice with targeted expression of MVNP to OCLs (MVNP mice) develop OCLs and bone lesions characteristic of PD. Importantly, loss of IL-6 expression in MVNP mice blocked the pagetic OCL formation and increased bone formation in vivo. Thus, expression of environmental factors (e.g., MVNP) in OCLs is required for the development of characteristic bone abnormalities in PD. Recently, we found that MVNP but not p62P394L increases expression of the coupling factors ephrinB2 by OCLs and EphB4 on osteoblasts (OBs), which was mediated by IL-6. These results suggest that MVNP in OCLs induces coupling factors that increase OB activity. Further, MVNP induced expression of IGF1 by OCLs which may further increase bone formation. This proposal will assess the role of MVNP in the abnormal OB activity in PD by testing the hypothesis that MVNP increases OB activity in PD through induction of ephrinB2 on OCLs and EphB4 on OBs, in part through MVNP's up-regulation of IL-6 and IGF1 in OCLs. Thus, we will: 1) Test the hypothesis that MVNP's induction of ephrinB2 and IGF1 in OCLs and EphB4 in OBs increases OB activity. We will determine the effects of modulating ephrinB2/EphB4 and IGF1 levels/activity on the increased OB activity induced by MVNP. We will also determine if MVNP expression in OCLs from p62P392L PD patients increases ephrinB2 and IGF1 in OCLs and enhances their capacity to induce OB differentiation. 2) Test the hypothesis that IL-6 and IGF1 mediate the induction of ephrinB2 and EphB4 by MVNP. We will determine the mechanisms responsible for IL-6's induction of ephrinB2/ EphB4 by MVNP, and if IGF1 enhances ephrinB2 and/or IL-6 production by OCLs expressing MVNP or simply enhances OB activity via ephrinB2/EphB4. For these studies, we will use cells from MVNP, WT, IL-6-/- and MVNP and WT mice with knockdown of IL-6 or IGF1 in OCLs ex vivo. 3) Generate p62/MVNP mice with targeted deletion of ephrinB2 and/or IGF1 in OCLs and EphB4 in OBs to assess the roles of ephrinB2/EphB4 and IGF1 in the increased OB activity in PD.

描述（由申请人提供）：佩吉特氏病（PD）是耦合骨重塑的最夸张的例子，其局部区域骨吸收增加并伴随着旺盛的新骨形成。过多的新骨形成导致脆弱的编织骨沉积，这是PD的许多临床后遗症的原因，包括骨畸形或骨折、颅骨增厚、骨痛和神经根受压。破骨细胞 (OCL) 促进骨形成增加，因为针对 OCL 的治疗会减少骨吸收和形成。然而，PD 中骨形成增加的机制尚不清楚。遗传和环境因素导致帕金森病的发生。与 PD 相关的最常见突变发生在 SQSTM1/p62 基因中，特别是 p62P392L。携带种系 p62P394L（p62 小鼠）（相当于人 p62P392L 的鼠科动物）的小鼠表现出 OCL 增加，但不会发展为 PD。 70% PD 患者的 OCL 表达麻疹病毒核衣壳蛋白 (MVNP) 基因，而针对 OCL 靶向表达 MVNP 的转基因小鼠（MVNP 小鼠）会出现 PD 特征性的 OCL 和骨病变。重要的是，MVNP 小鼠中 IL-6 表达的丧失阻止了分页 OCL 的形成并增加了体内骨形成。因此，OCL 中环境因素（例如 MVNP）的表达是 PD 特征性骨异常发生的必要条件。最近，我们发现MVNP而不是p62P394L增加成骨细胞（OB）上OCL和EphB4偶联因子ephrinB2的表达，这是由IL-6介导的。这些结果表明 OCL 中的 MVNP 诱导了增加 OB 活性的耦合因子。此外，MVNP 诱导 OCL 表达 IGF1，这可能进一步增加骨形成。该提案将通过测试以下假设来评估 MVNP 在 PD 异常 OB 活性中的作用：MVNP 通过诱导 OCL 上的 ephrinB2 和 OB 上的 EphB4 增加 PD 中的 OB 活性，部分是通过 MVNP 上调 IL-6 和 IGF1在 OCL 中。因此，我们将： 1) 检验以下假设：MVNP 诱导 OCL 中的 ephrinB2 和 IGF1 以及 OB 中的 EphB4 增加 OB 活性。我们将确定调节 ephrinB2/EphB4 和 IGF1 水平/活性对 MVNP 诱导的 OB 活性增加的影响。我们还将确定 p62P392L PD 患者 OCL 中的 MVNP 表达是否会增加 OCL 中的 ephrinB2 和 IGF1 并增强其诱导 OB 分化的能力。 2)检验IL-6和IGF1介导MVNP诱导ephrinB2和EphB4的假设。我们将确定 MVNP 导致 IL-6 诱导 ephrinB2/EphB4 的机制，以及 IGF1 是否通过表达 MVNP 的 OCL 增强 ephrinB2 和/或 IL-6 的产生，或者只是通过 ephrinB2/EphB4 增强 OB 活性。在这些研究中，我们将使用来自 MVNP、WT、IL-6-/- 以及 MVNP 和 WT 小鼠的细胞，并在离体 OCL 中敲低 IL-6 或 IGF1。 3) 生成 p62/MVNP 小鼠，定向删除 OCL 中的 ephrinB2 和/或 IGF1 以及 OB 中的 EphB4，以评估 ephrinB2/EphB4 和 IGF1 在 PD 中 OB 活性增加中的作用。