Collagen Glycosylation, Maturation and Mineralization

胶原蛋白糖基化、成熟和矿化

• 批准号: 8249266
• 负责人: MITSUO YAMAUCHI
• 金额: $ 19.4万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-04-01 至 2014-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8249266
• 关键词: 2-Oxoglutarate 5-Dioxygenase Procollagen-Lysine; 3-Dimensional; Address; Biological Assay; Biological Process; Bone Diseases; COL1A1 gene; COL1A2 gene; Cell Culture System; Cells; Clone Cells; Collagen; Collagen Type I; Complex; Data; Defect; Dental Enamel; Deposition; Enzymes; Family member; Galactosyltransferases; Gene Expression; Genes; Glucosyltransferase; Goals; High Pressure Liquid Chromatography; Hydroxylysine; Immunodeficient Mouse; In Vitro; Lead; Mass Spectrum Analysis; Minerals; Modeling; Modification; Molecular; Mutation; Osteoblasts; Osteogenesis; Osteogenesis Imperfecta; Outcome; Pathology; Pattern; Physiologic calcification; Post-Translational Protein Processing; Process; Role; Sirius Red F3B; Site; Spectroscopy, Fourier Transform Infrared; Staining method; Stains; System; Testing; Tissues; Transmission Electron Microscopy; Transplantation; analytical tool; base; biomineralization; bone; bone quality; crosslink; fibrillogenesis; glycosylation; glycosyltransferase; in vivo; insight; mineralization; molecular site; overexpression; tool

DESCRIPTION (provided by applicant): Fibrillar type I collagen is the predominant organic component in the mineralized tissues, except tooth enamel, providing a stable template to spatially control the deposition and packing of the mineral crystals. It has become clear that the pattern of collagen post-translational modifications is a critical factor for the formation of functional fibrils that eventually get mineralized. O-glycosylation of collagen is one of such unique modifications occurring at the specific hydroxylysine residues catalyzed sequentially by hydroxylysyl galactosyltransferase (GT) and, then, galactosylhydroxylysyl glucosyltransferase (GGT). Though alterations in collagen glycosylatioon have been implicated in collagen maturation and various bone disorders, the precise mechanisms and the functions of this modification in bone are not well understood. Most recently we have demonstrated that lysyl hydroxylase 3 functions as GGT and, possibly, glycosyltransferase 25 family member 1 (GLT25D1) as GT for bone type I collagen. Based on these and preliminary data, we hypothesized that by manipulating the expression of gene encoding GLT25D1 in osteoblastic cells, under- or overglycosylated type I collagen can be synthesized, and that this system can be used to elucidate the function of glycosylation in collagen maturation and mineralization in bone. To test the hypothesis, the following specific aims are proposed: Aim 1. To generate type I collagen with varied levels of glycosylation in osteoblastic cells and to define its role in collagen maturation and mineralization in vitro, Aim 2. To determine the effects of collagen glycosylation on collagen maturation and mineralization in an in vivo transplantation system. The proposed study should provide insights into the functions of glycosylation in collagen maturation and mineralization, thus, its involvement in bone formation and pathology, and its potential use for the assessment of bone quality. PUBLIC HEALTH RELEVANCE: The quality of fibrillar type I collagen is an important determinant for bone functions and it is established in part by the post-translational modifications. The goal of this study is to elucidate the mechanism and functions of collagen glycosylation in bone, and the results will advance our understanding of bone mineralization and could provide new insights into the mechanisms of bone disorders.

描述（由申请方提供）：纤维状I型胶原蛋白是矿化组织（牙釉质除外）中的主要有机组分，提供了稳定的模板，以在空间上控制矿物晶体的沉积和堆积。很明显，胶原蛋白翻译后修饰的模式是最终矿化的功能性原纤维形成的关键因素。胶原蛋白的O-糖基化是发生在特定羟赖氨酸残基上的独特修饰之一，依次由羟赖氨酰半乳糖基转移酶（GT）和半乳糖基羟赖氨酰葡糖基转移酶（GGT）催化。虽然胶原糖基化的改变与胶原成熟和各种骨疾病有关，但这种修饰在骨中的确切机制和功能还不清楚。最近，我们已经证明赖氨酰羟化酶3作为GGT发挥作用，并且可能地，糖基转移酶25家族成员1（GLT 25 D1）作为骨I型胶原的GT发挥作用。基于这些和初步的数据，我们假设，通过操纵成骨细胞中的GLT 25 D1编码基因的表达，下或过度糖基化的I型胶原蛋白可以合成，并且该系统可以用于阐明骨中胶原蛋白成熟和矿化中糖基化的功能。为了检验这一假设，提出了以下具体目标：目标1。目的2.在成骨细胞中诱导不同糖基化水平的I型胶原，并明确其在体外胶原成熟和矿化中的作用。确定体内移植系统中胶原糖基化对胶原成熟和矿化的影响。拟议的研究应提供深入了解糖基化在胶原蛋白成熟和矿化中的功能，因此，其参与骨形成和病理学，以及其用于评估骨质量的潜在用途。 公共卫生相关性：纤维状I型胶原蛋白的质量是骨功能的重要决定因素，并且其部分由翻译后修饰建立。本研究的目的是阐明骨胶原糖基化的机制和功能，其结果将促进我们对骨矿化的理解，并可能为骨疾病的机制提供新的见解。