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: 9256416
• 负责人: Garson DAVID ROODMAN
• 金额: $ 38.01万
• 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/9256416
• 关键词: Abnormal Cell; Affect; American; Area; Bone Pain; Bone Resorption; Bone remodeling; Cells; Characteristics; Clinical; Collagen Fiber; Coupled; Coupling; Deformity; Degenerative polyarthritis; Deposition; Development; Environmental Risk Factor; Ephrin-B2; Exhibits; Fracture; GTF2H1 gene; Gene Proteins; Genetic; Human; IGF1 gene; Immature Bone; Inherited; Interleukin-6; Lead; Lesion; Link; Measles virus nucleocapsid protein; Mediating; Mosaicism; Mouse Protein; Mus; Mutation; Nerve; Nerve Root Compressions; Osteitis Deformans; Osteoblasts; Osteoclasts; Osteogenesis; Paget' s Disease; Pathogenesis; Patients; Pattern; Phenotype; Plant Roots; Production; Role; Testing; Transgenic Mice; Up-Regulation; bone; clinical remission; cranium; in vivo; knock-down; mouse model; new therapeutic target; novel; osteoblast differentiation; protein expression; public health relevance

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）：Paget疾病（PD）是造成骨骼重塑的最夸张的例子与骨吸收增加的焦点区域以及伴随着新骨形成的焦点区域。过多的新骨形成导致弱编织骨的沉积，这是PD的许多临床后遗症，包括骨畸形或骨折，头骨增厚，骨痛和神经根部压缩。破骨细胞（OCLS）驱动增加的骨形成，因为靶向OCL的处理可减少骨吸收和形成。然而，导致PD骨形成增加的机制尚不清楚。遗传和环境因素有助于PD的发展。与PD相关的最常见突变是在SQSTM1/P62基因中，特别是p62p392l。含有种系P62P394L（p62小鼠）的小鼠，相当于人类p62p392l的鼠，表现出OCL的增加，但不会发展为PD。来自70％的PD患者的OCL表达了麻疹病毒核蛋白蛋白（MVNP）基因，而具有MVNP靶向表达的OCLS（MVNP小鼠）的转基因小鼠会发展出PD的OCLS和骨骼病变的特征。重要的是，在MVNP小鼠中IL-6表达的丧失阻塞了雌雄同体的OCL形成并在体内增加骨形成。因此，在PD中发展特征性骨异常需要环境因素（例如MVNP）的表达。最近，我们发现MVNP而不是p62p394l在成骨细胞上通过OCLS和EPHB4增加了耦合因子Ephrinb2的表达（obs），这是由IL-6介导的。这些结果表明，OCL中的MVNP诱导偶联因子增加OB活性。此外，MVNP通过OCL诱导IGF1表达，这可能会进一步增加骨形成。该提案将通过测试MVNP通过在OCLS和EPHB4上诱导EphrinB2在OCL上提高PD的OB活性来评估MVNP在PD异常OB活性中的作用，该假设通过MVNP在OCLS中的IL-6和IGF1上的上调而部分地通过ECLS和EPHB4对OBS进行了OBS的作用。因此，我们将：1）检验以下假设：MVNP在OCLS和EPHB4中诱导Ephrinb2和IgF1在OBS中增加了OB活性。我们将确定调节ephrinb2/ephb4和IgF1水平/活性对MVNP诱导的OB活性的影响。我们还将确定来自p62p392l PD患者的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）检验以下假设：IL-6和IGF1通过MVNP介导ephrinb2和ephb4的诱导。我们将确定MVNP诱导IL-6诱导Ephrinb2/ephb4的机制，如果IGF1通过表达MVNP或简单地通过Ephrinb2/ephb4增强OB活性的OCLS生产Ephrinb2和/或IL-6产生。在这些研究中，我们将使用MVNP，WT，IL-6 - / - 和MVNP和WT小鼠的细胞使用IL-6或IGF1敲低的OCLS Exvivo中的细胞。 3）在OCLS和EPHB4中产生p62/MVNP小鼠，在opts和ephb4中产生p62/mvnp小鼠，以评估ephrinb2/ephb4和igf1在PD中OB活性增加中的作用。