Targeting collagen as an interventional approach to improve bone material properties

将胶原蛋白作为改善骨材料特性的介入方法

• 批准号: 10159215
• 负责人: Joseph Michael Wallace
• 金额: $ 33.61万
• 依托单位: INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-05 至 2023-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10159215
• 关键词: Animals; Architecture; Biochemical; Biology; Bone Diseases; Bone Matrix; Bone Tissue; Cells; Collagen; Combined Modality Therapy; Communities; Coupled; Data; Deposition; Development; Diabetes Mellitus; Disease; Enzymes; Estrogen Receptors; Estrogens; FDA approved; Fatigue; Fracture; Gene Expression; Goals; Hydration status; Image; In Vitro; Individual; Intervention; Knowledge; Laboratories; Lathyrism; Mechanical Stimulation; Mechanics; Mediating; Minerals; Modeling; Molecular; Molecular Chaperones; Orthopedics; Osteoblasts; Osteocytes; Osteogenesis Imperfecta; Outcome Measure; Pharmaceutical Preparations; Pharmacologic Substance; Pharmacotherapy; Phenotype; Play; Post-Translational Protein Processing; Production; Property; Public Health; Raloxifene; Regulation; Resistance; Role; Signal Transduction; Solid; Stress Fractures; Stretching; Structure; Surface; Techniques; Testing; Tissues; Treatment Efficacy; Work; analog; base; bone; bone fatigue; bone fragility; bone health; bone mass; bone toughness; crosslink; density; ductile; experimental study; fluid flow; improved; in vivo; innovation; mechanical load; mechanical properties; mineralization; nanoscale; neglect; physical property; receptor binding; skeletal; stem

PROJECT SUMMARY Mechanical loading and pharmaceutical interventions both improve bone mechanical properties, but there is a critical gap in our understanding of the role that collagen plays in mediating these effects. This gap in knowledge by which collagen processing, organization, mineralization, and hydration change with combined load and drug treatment is a critical impediment to the development of combination therapies that increase fracture resistance by targeting tissue moieties other than mineral. Our long-term goal is to develop ways to alter physical properties of bone tissue to increase fracture resistance. The overall objective in this application is to elucidate how mechanical loading and a RAL-analog (RALA) modify newly forming and pre-existing bone to decrease fragility. The central hypothesis is that in addition to changes in mass and mineral, collagen-modifying effects exist for both loading and RALA, the combination of which interactively improve mechanical integrity beyond the effects of either monotherapy. The premise of this hypothesis stems from preliminary data generated in the applicants' laboratories. The rationale for the proposed work is that successfully making bone stronger and more resistant to fracture by combining RALA's hydrating effects with mechanical regulation of bone mass and perilacunar matrix activity could provide alternative ways for the orthopaedic community to approach the treatment of bone diseases. Guided by preliminary data, this hypothesis will be tested using three specific aims: 1) to define influences of loading on osteocyte perilacunar matrix activity and osteoblast matrix deposition; 2) to determine how RAL/RALA modify collagen quality and matrix hydration; and 3) to determine interactive effects of loading and RALA. Under the first aim, techniques already in place will be used to investigate in vitro and in vivo loading effects in healthy cells and animals, as well as in models of disrupted collagen synthesis. In vitro loading will be induced by substrate stretching for osteoblasts or pulsatile fluid flow for osteocytes. Gene expression of enzymes and chaperones will be quantified, as well as molecules associated with resorption. Matrix production, organization, composition and mechanical integrity will be assessed. For in vivo loading experiments, similar techniques will be used to assess collagen synthesis, post-translational modifications, and crosslinking along with nanoscale and whole bone tests of mechanical integrity, fatigue resistance and fracture toughness. In Aim 2, outcome measures from Aim 1 will be used to investigate the effects of RAL/RALA as a function of disease state. In Aim 3, interactive effects of combined loading and drug-based treatment will be assessed. The approach is innovative because of its focus on collagen, in addition to mass and architecture. It also focuses on osteoblast- produced collagen on surfaces and changes induced by osteocytes throughout the bone. This work is significant because it will demonstrate that interactions through combination therapies can improve skeletal mechanical phenotypes, not by correcting the disease cause, but by impacting collagen synthesis, assembly, mineralization, and tissue hydration. Such knowledge will provide new ways to approach treatment of fragility-related diseases.

项目概要 机械负荷和药物干预都可以改善骨的机械性能，但有一个 我们对胶原蛋白在调节这些作用中所起的作用的理解存在重大差距。这种知识上的差距 胶原蛋白的加工、组织、矿化和水合随着负荷和药物的组合而变化 治疗是开发提高骨折抵抗力的联合疗法的关键障碍 通过靶向矿物质以外的组织部分。我们的长期目标是开发改变物理特性的方法 骨组织以增加抗骨折能力。本申请的总体目标是阐明如何 机械负载和 RAL 模拟 (RALA) 可以修改新形成的和预先存在的骨骼，以降低脆性。 中心假设是，除了质量和矿物质的变化之外，胶原蛋白修饰作用还存在于 加载和 RALA，两者的结合可以交互地提高机械完整性，超越效果 任一单一疗法。这一假设的前提源于申请人的初步数据 实验室。拟议工作的基本原理是成功地使骨骼更坚固、更有抵抗力 通过将 RALA 的水化作用与骨量和腔周的机械调节相结合来预防骨折 基质活性可以为骨科界提供骨治疗的替代方法 疾病。在初步数据的指导下，该假设将通过三个具体目标进行测试：1）定义 负荷对骨细胞腔周基质活性和成骨细胞基质沉积的影响； 2）确定 RAL/RALA 如何改变胶原蛋白质量和基质水合作用； 3) 确定加载的交互效果 和拉拉。在第一个目标下，现有技术将用于研究体外和体内负载 对健康细胞和动物以及胶原蛋白合成破坏模型的影响。体外负载将是 由成骨细胞的基质拉伸或骨细胞的脉动液体流引起。酶的基因表达 分子伴侣以及与吸收相关的分子将被量化。矩阵制作， 将评估组织、组成和机械完整性。对于体内负载实验，类似 技术将用于评估胶原蛋白合成、翻译后修饰和交联 通过纳米级和全骨机械完整性、抗疲劳性和断裂韧性测试。瞄准 2、目标 1 的结果测量将用于研究 RAL/RALA 作为疾病函数的影响 状态。在目标 3 中，将评估联合负荷治疗和药物治疗的交互作用。方法 之所以具有创新性，是因为除了质量和结构之外，它还专注于胶原蛋白。它还专注于成骨细胞—— 在表面产生胶原蛋白，并由整个骨骼的骨细胞引起变化。这项工作意义重大 因为它将证明通过联合疗法的相互作用可以改善骨骼力学 表型，不是通过纠正疾病原因，而是通过影响胶原蛋白合成、组装、矿化， 和组织水合作用。这些知识将为治疗脆弱性相关疾病提供新方法。