The Roles of FAM20C (DMP4) in Odontogenesis and Osteogenesis

FAM20C (DMP4) 在牙发育和成骨中的作用

基本信息

批准号：
8968245
负责人：
Chunlin Qin
金额：
$ 36.38万
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：
2012
资助国家：
美国
起止时间：
2012-12-01 至 2017-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8968245
关键词：
Affect Ameloblasts Amelogenesis Amelogenesis Imperfecta Antibodies Backcrossings Biological Bone Tissue Cell Differentiation process Cell Line Cells Cementoblast Consumption Data Defect Dental Cementum Dental Enamel Dentin Dentin Formation Dentinogenesis Dentinogenesis Imperfecta Dentition Development Diet Differentiation Antigens Disease Failure Familial hypophosphatemic bone disease Family Health Hereditary Disease Homeostasis Human Hypophosphatemia In Vitro Intraperitoneal Injections Investigation Keratin Knockout Mice Lead Maintenance Mediating Mediation Metabolic Diseases Modeling Molecular Morphology Mus Mutant Strains Mice Mutation Odontoblasts Odontogenesis Osteoblasts Osteogenesis Osteosclerosis Pathogenesis Patients Phenotype Play Process Proteins Recombinants Regulation Research Proposals Rickets Role Serum Serum Phosphorus Level Skeleton Solid Testing Therapeutic Tissues Tooth structure Transgenes Work base biomineralization bone craniofacial complex dentin matrix protein 1 design deviant fibroblast growth factor 23 human disease in vivo innovation inorganic phosphate insight knock-down member mineralization novel osteogenic prevent protein function research study skeletal small hairpin RNA

项目摘要

DESCRIPTION (provided by applicant): This research proposal focuses on the biological roles of FAM20C (also known as Dentin Matrix Protein 4, DMP4) in the formation of dentin, cementum, enamel and bone. Our recent studies have established that this novel molecule plays crucial roles in odontogenesis and osteogenesis. We have discovered that the inactivation of Fam20C in mice leads to: 1) significant defects in the dentin, cementum, enamel and bone; 2) a decreased serum level of phosphorus in contrast to an elevated serum level of fibroblast growth factor 23 (FGF23); 3) loss of normal morphology of odontoblasts and ameloblasts; and 4) reduced expression of the differentiation markers for odontoblasts and osteoblasts [including dentin matrix protein 1 (DMP1), a differentiation/mineralization marker]. In vitro studies revealed that recombinant FAM20C promotes the differentiation of preosteoblasts and increases the expression of DMP1, while shRNA knockdown of FAM20C leads to a remarkable reduction of DMP1 and elevation of FGF23 in multiple osteogenic cell lines. Our preliminary data led us to believe that the inactivation of Fam20C prevents cells from differentiating into mature odontogenic/osteogenic cells and leads to hypophosphatemia. The combined results of cell differentiation failure and lower serum phosphate level cause defects in the teeth and bones of Fam20C-deficient mice. The following three Specific Aims are proposed to test the central hypothesis that FAM20C promotes the differentiation of cells forming mineralized tissues and regulates phosphate homeostasis via the mediation of FGF23: (1) To evaluate the molecular pathogenesis of FAM20C-associated disorders in mice and humans by analyzing the specific effects of FAM20C inactivation on odontoblasts, cementoblasts, osteoblasts and ameloblasts, and by examining whether the expression of a normal human FAM20C transgene can rescue the mouse Fam20C-deficient defects and if expressing a mutant mouse Fam20C transgene mimicking a human FAM20C mutation can recapitulate the phenotype identified in some human patients; (2) To determine if FAM20C is involved in biomineralization via the FGF23-mediated regulation of phosphate homeostasis by analyzing double Fam20C- and Fgf23-null mice, injecting anti-FGF23 antibodies and administering a high-phosphate diet in the Fam20C-deficient mice; and (3) To determine if FAM20C regulates DMP1 in dentinogenesis and osteogenesis by examining if expressing the Dmp1 transgene can rescue the dentin and bone defects in the Fam20C-deficient mice, and by analyzing the in vitro effects of adding or expressing DMP1 on Fam20C-deficient cell lines. The proposed studies, which are a necessary step in understanding how FAM20C functions in odontogenesis and osteogenesis, will contribute new insights into the molecular basis for genetic and metabolic disorders that affect the craniofacial complex and the axial skeleton.

描述（由申请人提供）：该研究建议着重于FAM20C（也称为牙本质基质蛋白4，DMP4）的生物学作用，在牙本质，水泥，搪瓷和骨骼的形成中。我们最近的研究表明，这种新型分子在牙生的作用和成骨中起着至关重要的作用。我们已经发现，小鼠FAM20C的失活导致：1）牙本质，胶质，搪瓷和骨骼中的明显缺陷； 2）与成纤维细胞生长因子23（FGF23）的血清水平升高相比，血清磷水平降低； 3）牙本质细胞和成成细胞的正常形态丧失； 4）降低了牙糖细胞和成骨细胞的分化标记表达[包括牙本质基质蛋白1（DMP1），分化/矿化标记]。体外研究表明该重组FAM20C促进了骨细胞前细胞的分化并增加了DMP1的表达，而FAM20C的shRNA敲低导致DMP1显着降低，而在多个成骨细胞系中，FGF23的升高和升高。我们的初步数据使我们相信FAM20C的失活可阻止细胞区分为成熟的牙源性/成骨细胞，并导致低磷酸血症。细胞分化衰竭和较低血清磷酸盐水平的综合结果导致FAM20C缺陷小鼠的牙齿和骨骼缺陷。提出了以下三个特定目的，以测试FAM20C促进形成矿化组织的细胞的分化的中心假设，并通过FGF23的介导：（1）评估FAM20C相关疾病的分子与人类的特定疾病的特定作用，以评估FAM 20成骨细胞和成蛋白细胞，以及检查正常的人类FAM20C转基因的表达是否可以挽救小鼠FAM20C缺陷缺陷，以及是否表达模仿人FAM20C突变的突变小鼠FAM20C转基因可以概括一些在某些人类患者中鉴定出的表型；（2）通过分析Double FAM20C和FGF23-NULL小鼠，通过FGF23介导的磷酸稳态调节来确定FAM20C是否参与了生物矿化，并在FAM20C-DECE-DEDECEFICIGINIC中注入了抗FGF23抗体并给予抗FGF23抗体并给予高磷酸盐饮食；（3）确定FAM20C是否通过检查表达DMP1转基因是否可以挽救FAM20C缺陷型小鼠中的牙本质和骨缺损，以及通过分析对FAM20C-20C20C缺陷型DMP1的体外效应来挽救牙本质和骨缺损来调节DMP1。提出的研究是了解FAM20C在牙肠发生和成骨中的作用的必要步骤，它将为影响颅面复合物和轴向骨骼的遗传和代谢性疾病的分子基础提供新的见解。