Studies of the Roles of DMP1 and DSPP in Osteogenesis and Dentinogenesis

DMP1和DSPP在成骨和牙本质形成中的作用研究

基本信息

批准号：
7810418
负责人：
Chunlin Qin
金额：
$ 35.53万
依托单位：
TEXAS A&M UNIVERSITY HEALTH SCIENCE CTR
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-09-23 至 2011-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7810418
关键词：
Ablation Affect Apatites Award Binding Biochemical Biological Process Biotin Categories Cell Nucleus Cells Chemical Structure Cleaved cell Collagen Type I Complex Core Protein DSPP gene Data Defect Dental Dentin Dentin Formation Dentinogenesis Dentinogenesis Imperfecta Disease Eukaryota Eukaryotic Cell Event Extracellular Matrix Extracellular Matrix Proteins Failure Family Family member Funding Gene Cluster Gene Expression Regulation Genes Genetic Glycosaminoglycans Human Human Genetics In Vitro Knock-in Mouse Knockout Mice Label Lead Length Mesenchymal Differentiation Methodology Modality Molecular Mus Mutant Strains Mice Mutation N-terminal Odontoblasts Osteoblasts Osteogenesis Osteoid Osteomalacia Osteoporosis Parents Pathogenesis Pathway interactions Peptide Hydrolases Peptides Phenotype Physiologic calcification Play Post-Translational Protein Processing Process Protein Binding Proteins Proteoglycan Proteolytic Processing Recovery Research Rickets Role Series Siblings Side Site Skeleton Solid Structure Surface Plasmon Resonance Systemic disease Testing Time Tissues Transgenic Organisms United States National Institutes of Health Variant Work base biomineralization bone craniofacial complex dentin matrix protein 1 in vivo insight member mineralization mouse Dspp protein osteoblast differentiation parent grant protein function protein protein interaction public health relevance research study response skeletal disorder transcription factor yeast two hybrid system

项目摘要

DESCRIPTION (provided by applicant): This application is in response to the NIH Notice Number NOT-OD-09-058, entitled "NIH Announces the Availability of Recovery Act Funds for Competitive Revision Applications". The research proposed in this competitive revision application as well as the parent grant application focuses on dentin matrix protein 1 (DMP1) and dentin sialophosphoprotein (DSPP), two non-collagenous extracellular matrix (ECM) proteins that belong to the SIBLING family. The importance of DMP1 and DSPP in biomineralization has been demonstrated by studies showing that humans or mice with altered Dmp1 or Dspp gene display defects in the mineralization of bone and/or dentin. Although solid data have demonstrated the association between these two proteins and the formation of healthy bone and/or dentin, the specific mechanistic pathways by which DMP1 and DSPP participate in osteogenesis and dentinogenesis remain ill-defined. Studies proposed in this competitive revision application and in the parent grant application are aimed to test how proteolytic processing of DMP1 and DSPP affects the mineralization of bone and/or dentin. The following data from our independent and collaborative studies have established that DMP1 and DSPP undergo proteolytic processing and that posttranslational processing may be essential for the mineralization of bone and/or dentin. Our findings include: 1) DMP1 and DSPP are present in the ECM of bone and dentin as NH2-terminal and COOH-terminal fragments. 2) Proteolytic processing of DMP1 and DSPP involves cleavage at selected X-Asp bonds. 3) The NH2-terminal fragments of DMP1 and DSPP have biochemical features distinct from those of their respective COOH-terminal fragments. 4) The COOH-terminal fragments of DMP1 and DSPP promote mineralization in vitro. 5) Substitution of an aspartyl residue at a cleavage site blocks the proteolytic processing of DMP1 in eukaryotes. 6) Re-expression of the COOH-terminal fragment of DMP1 is capable of rescuing the mineralization defects in Dmp1-null mice. 7) The NH2-terminal fragment and COOH-terminal fragment of DMP1 show clear difference in tissue localization. We hypothesize that proteolytic processing of DMP1 and DSPP is an activation step that converts precursors from inactive forms to fragments that are fully active at the correct time and site to control the mineralization process. To test the above hypothesis, we propose a series of studies to determine 1) if failure to process these two proteins due to substitution of Asp residues at key cleavage sites will result in the loss of DMP1 or DSPP functions in vivo, 2) to characterize the roles of the COOH- terminal and NH2-termnial fragments of DSPP, and 3) to determine the protein-protein interactions involving the processed fragments of DMP1 and DSPP. PUBLIC HEALTH RELEVANCE: Fundamental information about how DMP1 and DSPP affect the formation of bone and dentin is essential to enhanced understanding concerning the pathogeneses of bony and dental defects associated with systemic diseases such as osteomalacia, osteoporosis and dentinogenesis imperfecta. Results of the studies proposed in this application will unfold greater understanding of the mechanisms controlling the mineralization of bone and dentin, thus proving information needed for delineating the pathogeneses underlying these bony and dental defects and for establishing scientifically based treatment modalities for such skeletal diseases.

描述（由申请人提供）：此申请是响应NIH通知号而不是-OD-09-058，标题为“ NIH宣布恢复ACT的可用性用于有竞争力的修订申请”。在本竞争性修订应用中提出的研究以及父母赠款的应用集中在牙本质基质蛋白1（DMP1）和牙糖唾液酸磷蛋白（DSPP），两个非胶质细胞外基质（ECM）蛋白质蛋白，属于同胞家族。 DMP1和DSPP在生物矿化中的重要性已经证明了DMP1或DSPP基因改变的人或小鼠在骨骼和/或牙本质的矿化中显示出缺陷。尽管固体数据证明了这两种蛋白质与健康骨和/或牙本质的形成之间的关联，但DMP1和DSPP参与骨生成的特定机械途径和牙齿发生仍然不确定。在此竞争性修订应用中和父母赠款应用中提出的研究旨在测试DMP1和DSPP的蛋白水解处理如何影响骨骼和/或牙本质的矿化。来自我们独立和协作研究的以下数据已经确定，DMP1和DSPP经历蛋白水解处理，并且翻译后处理对于骨骼和/或牙本质的矿化可能至关重要。我们的发现包括：1）DMP1和DSPP存在于骨骼和牙本质中，作为NH2末端和COOH末端片段。 2）DMP1和DSPP的蛋白水解处理涉及在选定的X-ASP键处进行裂解。 3）DMP1和DSPP的NH2末端片段的生化特征不同于其各自的COOH末端片段。 4）DMP1和DSPP的COOH末端片段在体外促进矿化。 5）在裂解位点取代天冬氨酸残基会阻止真核生物中DMP1的蛋白水解加工。 6）DMP1的COOH末端片段的重新表达能够挽救DMP1-NULL小鼠中的矿化缺陷。 7）DMP1的NH2末端片段和COOH末端片段在组织定位方面显示出明显的差异。我们假设DMP1和DSPP的蛋白水解处理是一个激活步骤，将前体从不活动形式转换为在正确的时间和位点完全活跃以控制矿化过程的片段。为了检验上述假设，我们提出一系列研究以确定1）是否由于在关键裂解位点取代ASP残基而未能处理这两种蛋白质，是否会导致DMP1或DSPP在体内的功能丧失，2）表征COOH-终端和NH2-Termnial fressign ressial ressial and restient ressial ressial and NH2-Termnial frampppp frabite fractir fractir fractient fractecppp和3）的作用。 DMP1和DSPP。公共卫生相关性：有关DMP1和DSPP如何影响骨骼和牙本质形成的基本信息，对于增强与全身性疾病相关的骨质疾病，骨质疏松症，骨质疏松症和牙本质发生的理解至关重要。本应用中提出的研究的结果将展开对控制骨骼和牙本质矿化的机制的更多了解，从而证明了描述这些骨缺陷和牙齿缺陷的病原体所需的信息，并建立了基于科学的治疗方法来为此类骨架疾病。