SPARC controls transglutaminase-mediated collagen I cross-links in periodontal disease

SPARC 控制牙周病中转谷氨酰胺酶介导的 I 型胶原蛋白交联

基本信息

批准号：
9981413
负责人：
Emilie Moore Rosset
金额：
$ 5.08万
依托单位：
MEDICAL UNIVERSITY OF SOUTH CAROLINA
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-09-01 至 2020-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9981413
关键词：
Adult Affect Age Alveolar Bone Loss Amino Acids Architecture Binding Binding Proteins Caliber Characteristics Chronic Collagen Collagen Fiber Collagen Fibril Collagen Type I Cyanogen Bromide Cysteine Data Dental Cementum Deposition Detection Digestion Disease Disease model Enterobacteria phage P1 Cre recombinase Exhibits Extracellular Matrix Extracellular Protein Family Fiber Fibroblasts Future Genes Goals Health Homeostasis Inflammation Inflammatory Injections Injury Intervention Knockout Mice Laboratories Lead Left Ligation Ligature LoxP-flanked allele Maps Mass Spectrum Analysis Mechanics Mediating Methodology Microbial Biofilms Modeling Mus Natural regeneration Patients Peptides Periodontal Diseases Periodontal Ligament Periodontium Pharmacology Population Proteins Recombinants Regulation Reporting Research Role Scientist Secure Site Structure Substrate Specificity Tamoxifen Testing Time Tissues Tooth Loss Tooth root structure Tooth structure Training Transglutaminases United States Wild Type Mouse alveolar bone bone career clinically relevant crosslink discrete time extracellular gain of function healing improved in vitro activity in vivo inhibitor/antagonist insight ligament injury link protein loss of function mouse model promoter recombinase repaired response to injury

项目摘要

Project Summary/Abstract The collagen fibers that span the periodontal ligament (PDL) connect teeth to the bone socket by weaving through the cementum of each tooth as well as into the alveolar bone. Collagen type I is the main structural component of PDL. High rates of extracellular matrix (ECM) turnover are characteristic of PDL tissue. Periodontal disease (PD) afflicts approximately 50% of the population in the United States. PD is marked by chronic inflammation of the periodontium leading to PDL degradation, alveolar bone loss, and eventual tooth loss. There are currently no accepted methodologies to regenerate this collagenous PDL tissue. Thus PDL provides an excellent tissue milieu for investigating mechanisms of collagen processing and assembly during inflammatory states that are clinically relevant. SPARC, a collagen-binding protein, has been identified as a key factor in collagen ECM deposition. We reported that SPARC-null mice have significantly less total collagen, thinner collagen fibers, and reduced mechanical strength in PDL compared to wild type (WT) PDL. A key factor in incorporation and stabilization of insoluble collagen within the ECM is mediated through collagen crosslinking. Transglutaminases (TGs) are a family of extracellular proteins known to participate in collagen cross-linking activity in vitro and in vivo. Previous data implicate SPARC as a critical regulator of TG activity on collagen I in homeostatic PDL. Inhibition of TG activity in vivo was shown to reverse SPARC-dependent decreases in collagen volume fraction and mechanical strength of homeostatic PDL. Our data predicts SPARC regulates TG activity by mediating substrate specificity in the ECM, however, the mechanisms by which cross- links influence collagen architecture and repair during and following inflammatory injury is unknown. We hypothesize that increases in tissue TG (TG2) activity in response to injury diminishes collagen fiber content and mechanical strength in the PDL and that manipulation of TG2 activity through either expression of SPARC or pharmacological intervention will improve collagen deposition and repair in a model of PD. We will investigate our hypothesis through the following Specific Aims: 1. Using a clinically relevant murine model of PD, demonstrate TG2 activity is increased in WT mice with PD and further enhanced in the absence of SPARC, 2. Demonstrate that collagen assembly and mechanical strength of healing PDL is decreased by increased TG activity, and 3. Demonstrate that loss of SPARC expression in fibroblasts drives increased TG-dependent cross-linking of collagen I in PD. This project will determine the role of SPARC in the regulation of TG2-mediated collagen cross-links during and following inflammatory PDL injury. The training plan proposed here will test the above hypothesis and prepare the applicant for a successful career as an academic scientist.

项目概要/摘要跨越牙周膜 (PDL) 的胶原纤维通过编织将牙齿连接到骨槽穿过每颗牙齿的牙骨质并进入牙槽骨。 I型胶原蛋白是主要结构 PDL 的组成部分。高细胞外基质 (ECM) 周转率是 PDL 组织的特征。牙周病 (PD) 困扰着美国约 50% 的人口。 PD 标记为牙周组织的慢性炎症导致 PDL 降解、牙槽骨丢失，最终导致牙齿脱落损失。目前还没有公认的方法来再生这种胶原 PDL 组织。因此PDL 为研究胶原蛋白加工和组装的机制提供了良好的组织环境临床相关的炎症状态。 SPARC 是一种胶原蛋白结合蛋白，已被确定为胶原蛋白 ECM 沉积的关键因素。我们报道 SPARC 无效小鼠的总与野生型 (WT) PDL 相比，PDL 中的胶原蛋白、更薄的胶原纤维和更低的机械强度。一个不溶性胶原蛋白在 ECM 中的掺入和稳定的关键因素是通过胶原蛋白介导的交联。转谷氨酰胺酶 (TG) 是已知参与胶原蛋白形成的细胞外蛋白家族体外和体内的交联活性。之前的数据表明 SPARC 是 TG 活动的关键调节者稳态 PDL 中的胶原蛋白 I。抑制体内 TG 活性可逆转 SPARC 依赖性胶原蛋白体积分数和稳态 PDL 机械强度降低。我们的数据预测 SPARC 通过介导 ECM 中的底物特异性来调节 TG 活性，然而，交叉的机制链接对炎症损伤期间和之后的胶原结构和修复的影响尚不清楚。我们假设损伤后组织 TG (TG2) 活性增加会减少胶原纤维 PDL 中的含量和机械强度以及通过任一方式操纵 TG2 活性 SPARC 的表达或药物干预将改善胶原沉积和修复 PD 模型。我们将通过以下具体目标来研究我们的假设： 1. 使用临床相关的 PD 小鼠模型，证明 TG2 活性在患有 PD 的 WT 小鼠中增加并进一步增强在没有 SPARC 的情况下，2. 证明愈合 PDL 的胶原蛋白组装和机械强度是 TG 活性增加而降低，并且 3. 证明成纤维细胞中 SPARC 表达的丧失驱动 PD 中 I 型胶原蛋白的 TG 依赖性交联增加。该项目将确定 SPARC 在炎症性 PDL 损伤期间和之后 TG2 介导的胶原交联的调节。培训内容这里提出的计划将检验上述假设，并为申请人作为成功的职业生涯做好准备学术科学家。