DETERMINATION AND EXPRESSION OF AMELOGENIN GENE PRODUCTS

釉原蛋白基因产物的测定和表达

• 批准号: 7812613
• 负责人: Malcolm L. Snead
• 金额: $ 39.99万
• 依托单位: UNIVERSITY OF SOUTHERN CALIFORNIA
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-23 至 2013-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7812613
• 关键词: Address; Adipocytes; Adipose tissue; Bone Marrow; Cell Lineage; Cells; Cementoblast; Circadian Rhythms; Congenital Abnormality; Data; Defect; Dental Cementum; Dental Enamel; Employment; Enamel Formation; Fatty acid glycerol esters; Fibroblasts; Figs - dietary; Funding; Gene Expression; Genetic Transcription; Human; Human Genetics; In Vitro; Investigation; Jaw; Knockout Mice; Lead; Measures; Mediating; Mesenchymal Stem Cells; Metabolic Bone Diseases; Minerals; Monkeys; Mus; Muscle; National Institute of Dental and Craniofacial Research; Natural regeneration; Operative Surgical Procedures; Oral mucous membrane structure; Organism; Osteoblasts; Osteogenesis; Parents; Pathway interactions; Periodontal Ligament; Postdoctoral Fellow; Process; Protein Isoforms; Proteins; RNA Splicing; Rattus; Recovery; Regenerative Medicine; Regulation; Role; Scientist; Signal Pathway; Signal Transduction; Stem cells; Strategic Planning; Stromal Cells; Structural Protein; Structure; Testing; Therapeutic Intervention; Tissues; Tooth structure; Transcript; Transgenes; Transgenic Mice; Trauma; United States National Institutes of Health; Weaning; Wild Type Mouse; amelogenin; biomineralization; bone; bone loss; bone mass; bone sialoprotein; cell behavior; cell type; embryonic stem cell; factor C; improved; in vivo; inhibitor/antagonist; leucine-rich amelogenin peptide; lipid biosynthesis; novel; novel strategies; osteogenic; parent grant; public health relevance; research study; stem cell differentiation; transcription factor; tumor

DESCRIPTION (provided by applicant): This project is part of NOT-OD-09-058, with Notice Title, "NIH Announces the Availability of Recovery Act Funds for Competitive Revision Applications" and is consistent with the aims of parent grant DE06988 which seeks to determine if amelogenin proteins contribute to cell behavior by promoting signals that change differentiation. In this project we expand parent grant specific aim 3, to expand the scope of investigation into the role of amelogenin to include their capacity to induce an osteogenic pathway in stem cells. The scope of this Competitive Revision project will enhance the pace of discovery and it will provide additional employment for post-doctoral scientists. One of the amelogenin splicing isoforms, Leucine-rich Amelogenin Peptide (LRAP) has been shown to induce osteogenesis in various cell types, including rat muscle fibroblasts, mouse cementoblasts, mouse oral mucosal cells, and mouse embryonic stem cells. Our preliminary studies have shown that LRAP stimulates osteoblastogenesis and inhibits adipogenesis of bone marrow mesenchymal stem cells (BMMSC). Canonical Wnt/2-catenin signaling pathway is activated upon LRAP treatment; while a specific Wnt inhibitor sFRP-1, completely blocks LRAP-mediated lineage selection of BMMSCs. We hypothesize that LRAP is capable of modulating the reciprocal relationship between osteogenic and adipogenic cell lineages in BMMSCs through activating the canonical Wnt/2-catenin pathway. We propose the following specific aims to test this hypothesis. Aim I: To determine whether activation of the canonical Wnt/ 2 -catenin pathway by LRAP is necessary and sufficient to stimulate osteoblastogenesis and to inhibit adipogesis of BMMSCs in vitro. Aim II: To investigate the mechanism by which LRAP activates the canonical Wnt/2-catenin pathway and to characterize the functional domain(s) in LRAP. Aim III: To examine the in vivo effect of LRAP on bone and adipose tissue in transgenic mice expressing the LRAP transgene in bone marrow and in amelogenin null mice. PUBLIC HEALTH RELEVANCE: A previously unrecognized function of amelogenin proteins is to stimulate the differentiation of stem cells towards bone formation while suppressing their differentiation into fat forming cells. This switch is activated by amelogenin stimulating the Wnt signaling cascade. Utilizing amelogenin proteins may improve surgical correction of birth defects, trauma and tumor induced bone loss by providing a means to stimulate bone formation replacing foreign materials with real bone.

描述（由申请人提供）：本项目是NOT-OD-09-058的一部分，通知标题为“NIH宣布恢复法案资金可用于竞争性修订申请”，并且与母基金DE 06988的目的一致，该母基金旨在确定釉原蛋白是否通过促进改变分化的信号而有助于细胞行为。在这个项目中，我们扩大了父母资助的具体目标3，扩大了对釉原蛋白作用的研究范围，包括它们在干细胞中诱导成骨途径的能力。这个竞争性修订项目的范围将提高发现的速度，并将为博士后科学家提供额外的就业机会。釉原蛋白剪接异构体之一，富含亮氨酸的釉原蛋白肽（LRAP）已显示在各种细胞类型中诱导成骨，包括大鼠肌肉成纤维细胞、小鼠成牙骨质细胞、小鼠口腔粘膜细胞和小鼠胚胎干细胞。我们的初步研究表明，LRAP刺激成骨细胞和抑制骨髓间充质干细胞（BMMSC）的脂肪形成。经典Wnt/2-连环蛋白信号通路在LRAP处理后被激活;而特异性Wnt抑制剂sFRP-1完全阻断LRAP介导的BMMSC谱系选择。我们假设LRAP能够通过激活经典的Wnt/2-catenin通路来调节BMMSCs中成骨和成脂细胞谱系之间的相互关系。我们提出以下具体目标来检验这一假设。目标一：确定LRAP激活经典Wnt/ 2 -catenin通路是否是体外刺激成骨细胞生成和抑制BMMSCs脂肪生成的必要和充分条件。目的II：研究LRAP激活经典Wnt/2-catenin通路的机制，并鉴定LRAP的功能结构域。目标三：在骨髓中表达LRAP转基因的转基因小鼠和无釉原蛋白的小鼠中检查LRAP对骨和脂肪组织的体内作用。 公共卫生相关性：釉原蛋白以前未被认识的功能是刺激干细胞向骨形成的分化，同时抑制它们向脂肪形成细胞的分化。该开关由釉原蛋白刺激Wnt信号级联激活。利用釉原蛋白可以通过提供一种用真实的骨替代异物来刺激骨形成的方法，从而改善出生缺陷、创伤和肿瘤引起的骨丢失的手术矫正。