权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

The Dynamic Range of Site-1 Protease Functions in Skeletal Development

骨骼发育中 Site-1 蛋白酶功能的动态范围

基本信息

批准号：
9032449
负责人：
Debabrata Patra
金额：
$ 33.55万
依托单位：
WASHINGTON UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-04-01 至 2020-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9032449
关键词：
Ablation Adolescent Antibodies Binding Proteins Biological Biological Process Bone Density Bone Development Bone Growth C-terminal Calcium Cartilage Cartilage Matrix Cells Chondrocytes Collagen Type II Complex Connective Tissue Consensus Sequence Coupled Defect Deformity Degenerative polyarthritis Development Down-Regulation Dwarfism Embryo Endoplasmic Reticulum Enzymes Exhibits Fluorescence Resonance Energy Transfer Fluorescent Dyes Foundations Fura-2 Future Genes Growth and Development function Health Homeostasis Image Intervertebral disc structure Investigation Knock-out Knockout Mice Knowledge Kyphosis deformity of spine Laboratories Lead Light Lipids Maintenance Mass Spectrum Analysis Membrane Membrane Lipids Microarray Analysis Modeling Molecular Mus Osteoblasts Osteocalcin Osteogenesis Pathology Pathway interactions Peptide Hydrolases Phenotype Phosphorylation Play Process Procollagen Property Proprotein Convertases Proteins Proteolysis Regulation Regulatory Element Role Shapes Signal Pathway Skeletal Development Skeleton Spectrometry, Mass, Electrospray Ionization Staging Sterols System Transforming Growth Factor beta Type II Procollagen Vertebral column Vertebrates biological adaptation to stress bone cartilage development chondrodysplasia clinical phenotype design endoplasmic reticulum stress falls gel electrophoresis insight lipid metabolism long bone mouse model novel novel strategies novel therapeutics parathyroid hormone (1-34)postnatal programs response scoliosis secretion process secretory protein site-1 protease skeletal skeletal abnormality spine bone structure trafficking transcription factor two-dimensional

项目摘要

DESCRIPTION (provided by applicant): The proprotein convertase Site-1 protease (S1P) has emerged as a critical regulator of mammalian skeletal development. It is an indispensable component of the regulated intramembrane proteolysis systems that govern lipid metabolism and endoplasmic reticulum stress response. Our studies implicate S1P as a mandatory component of the protein secretory apparatus that defines all connective tissues. We have studied the functions of S1P in a progressive set of S1P knock-out mouse models using Col2-Cre, Col2-CreER(T) and Osx-Cre mice. In addition to a lipid phenotype, studies on S1P ablation in chondroprogenitor cells (S1Pcko model) have demonstrated chondrodysplasia characterized by the specific endoplasmic reticulum (ER) entrapment of type IIB procollagen, poor cartilage matrix development, and loss of endochondral bone formation in mice. Our recent studies demonstrated that along with type IIB procollagen, chondrocytes are also unable to secrete Adamts3, the type II procollagen N-proteinase. We have discovered a well-conserved S1P consensus sequence in the C-terminus of Adamts3, which suggests mandatory C-terminal processing of Adamts3 by S1P. Post-natal S1P ablation in chondrocytes (using Col2-CreER(T)) demonstrated complete disruption of hypertrophic chondrocyte differentiation. When we followed this observation by ablating S1P in prehypertrophic chondrocytes and osteoblasts using Osx-Cre mice, adolescent mice exhibited kyphosis and scoliosis coupled to chondrodysplasia and fragile long bones. These observations confirm the requirement of S1P to overall skeletal development and suggest potential cell-specific functions for S1P. Our mechanistic characterization of the S1Pcko model has demonstrated that lipid metabolism is down-regulated in S1Pcko chondrocytes. Disrupted ER membrane functions induced by changes in lipid composition may trap the type IIB procollagen in the ER. In light of these findings, in Specific Aim 1 we will investigate deviations in S1Pcko ER membrane lipid composition by mass spectrometry and analyze disrupted ER membrane functions by calcium imaging. In Specific Aim 2 we will investigate Adamts3 as a novel S1P substrate and analyze whether type IIB procollagen trafficking is regulated by a physical association with Adamts3. We will also study cartilage-specific ablation of Adamts3 in mice to analyze its role in cartilage development and maintenance. In Specific Aim 3, taking the lead from our previous knock-out models, we will characterize how disruptions in chondrocyte and osteoblast functions due to S1P ablation could lead to spine abnormalities in order to identify the biological trigger required for kyphosis and scoliosis development. This approach will allow investigation of multiple novel functions of S1P; additionally it will also provide novel insights into the regulation of protein secretory pathways and how their disruptions lead to the clinical phenotypes of chondrodysplasia and spine deformities.