The role of collagen cross-links in craniofacial bone quality and healing

胶原蛋白交联在颅面骨质量和愈合中的作用

• 批准号: 9899733
• 负责人: Genevieve Elizabeth Romanowicz
• 金额: $ 5.13万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-01 至 2021-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9899733
• 关键词: 2-Oxoglutarate 5-Dioxygenase Procollagen-Lysine; Advanced Glycosylation End Products; Area; Atomic Force Microscopy; Biological; Bone Regeneration; Bone Surface; Caliber; Cells; Collagen; Collagen Fibril; Collagen Type I; Cuboidal Cell; Data; Diabetes Mellitus; Disease; Dose; Enzyme Inhibition; Enzymes; Exhibits; Experimental Models; Family; Femur; Geometry; Hematoxylin and Eosin Staining Method; High Pressure Liquid Chromatography; Histology; Homeostasis; Impairment; Label; Lead; Malnutrition; Mandible; Measures; Mechanics; Minerals; Modeling; Modification; Mus; Operative Surgical Procedures; Oral cavity; Osteoblasts; Osteoclasts; Osteogenesis; Osteogenesis Imperfecta; Outcome; Outcome Study; Pathway interactions; Patients; Pattern; Pharmacology; Physiologic calcification; Polymers; Process; Protein-Lysine 6-Oxidase; Proteins; Raman Spectrum Analysis; Regulation; Research Personnel; Rheumatoid Arthritis; Role; Site; Skeleton; Stains; Structure; Systemic Therapy; Systemic disease; Testing; Tissue Engineering; Tissues; Tooth Extraction; bone; bone healing; bone quality; craniofacial; craniofacial bone; crosslink; expectation; experimental study; fluorophore; healing; inhibitor/antagonist; insight; mechanical properties; microCT; mineralization; mouse model; nanoindentation; organizational structure; response; success; tartrate-resistant acid phosphatase; wound; wound healing

Project Summary Abstract: Bone is continually remodeled and must maintain homeostasis of both the collagen and mineral components. Collagen is the primary matrix protein found in bone; it provides the structural organization and is a determinant of whole bone mechanical properties. Collagen is post-translationally modified by the lysyl oxidase (LOX) enzyme family to produce a distinct profile of mature and immature cross-links. The composition of cross-links is thought to alter the collagen fibril diameter and D-spacing, and altered fibril geometry may lead to altered mineralization. In experimental models of perturbed collagen cross-links, the mechanical strength and toughness directly correlate to the cross-link profile. Therefore, it is possible that compositional changes are contributing to the altered structure and function in patients suffering from a variety of systemic conditions that also exhibit reduced bone quality. The mechanisms controlling collagen cross-linking and mineralization in homeostasis and healing are understudied in the axial skeleton and craniofacial bones. Collagen content and relative cross-link maturity differ between the axial and craniofacial bones, and therefore may respond differently to altered LOX activity. My preliminary data suggests that altered collagen-cross-link profiles may be associated with an increase in the relative mineralization in the axial skeleton, but a decrease in the craniofacial bone. My central hypothesis is that collagen cross-linking dictates mineralization by controlling fibril diameter and collagen D-spacing and that inhibition of cross-linking compromises bone quality and healing in osseous wound sites. Two aims are proposed: 1) Define the role of collagen cross-links in craniofacial and axial bone mineralization, i2) Determine the effect of impaired collagen cross-links on craniofacial bone quality during healing after molar extraction. These studies will be accomplished using an established mouse model, where LOX-family enzymes are inhibited by treatment with a pharmacological agent, beta-aminoproprionitrile (BAPN). This model reduces the amount and alters the profile of cross-links in a dose dependent fashion. I will determine the fibril diameter and D-spacing via atomic force microscopy, mineral and collagen changes via Raman spectroscopy, and compare the response of craniofacial bone to axial bone. A molar extraction model will then be used to determine the effect of partial LOX-family enzyme inhibition on healing in craniofacial bone. Histology and histomorphometry will be used to determine the overarching effects on osteoblasts and osteoclasts. The outcomes of the proposed experiments will gain insight into the role of collagen cross-links in mineral composition, mechanical properties, and healing processes of axial and craniofacial bone for application in a variety of systemic conditions. Collagen cross-links are relatively easily manipulated via the LOX-family enzymes and therefore may serve as a target for disease therapy or for controlled use in tissue engineering.

项目摘要摘要： 骨头不断重塑，必须保持胶原蛋白和矿物质成分的体内平衡。 胶原蛋白是在骨骼中发现的主要基质蛋白。它提供了结构组织，是 全骨机械性能的决定因素。胶原蛋白是通过赖氨酸氧化酶在后翻译后修饰的 （LOX）酶家族产生成熟和不成熟的交联的不同特征。的组成 人们认为交联会改变胶原蛋白原纤维直径和D间距，并且原纤维几何形状可能导致 矿化改变。在扰动胶原蛋白交联的实验模型中，机械强度和 韧性与交联轮廓直接相关。因此，组成的变化可能是 在患有多种系统状况的患者中导致结构和功能的改变 还表现出降低的骨质质量。控制胶原蛋白交联和矿化的机制 稳态和愈合在轴向骨骼和颅骨骨骼中被研究了。胶原蛋白含量和 轴向骨骼和颅面骨骼之间的相对交联成熟度有所不同，因此可能会做出反应 与改变的LOX活性不同。我的初步数据表明，改变的胶原蛋白交联轮廓可能是 与轴向骨骼中相对矿化的增加相关，但减少 颅骨骨骼。我的中心假设是胶原蛋白交联决定了矿化 控制原纤维直径和胶原蛋白D间距，并抑制交联折衷 骨质伤口部位的骨骼质量和愈合。 提出了两个目的：1）定义胶原蛋白交联在颅面和轴向骨矿化中的作用， i2）确定胶原蛋白交联受损的影响对摩尔后治愈过程中颅面骨质的影响 萃取。这些研究将使用已建立的小鼠模型来完成，其中Lox家庭酶 用药理学剂，β-氨基异丙二氮（BAPN）抑制。该模型减少了 以剂量依赖的方式改变数量并改变交联的轮廓。我将确定原纤维直径 以及通过原子力显微镜，矿物和胶原蛋白通过拉曼光谱法变化的D间距，以及 比较颅面骨与轴向骨的反应。然后将使用摩尔提取模型 确定部分Lox家族酶抑制对颅面骨骼中愈合的影响。组织学和 组织形态法将用于确定对成骨细胞和破骨细胞的总体影响。这 提出的实验的结果将深入了解胶原蛋白交联在矿物质中的作用 轴向和颅面骨的组成，机械性能以及用于在 各种系统条件。胶原蛋白交联相对容易通过Lox家庭操纵 酶，因此可以作为疾病疗法的靶标或在组织工程中使用。