Molecular Regulatory Mechanism of Calvaria Bone Development and Homeostasis

颅盖骨发育与稳态的分子调控机制

基本信息

批准号：
10133045
负责人：
Junichi Iwata
金额：
$ 36.58万
依托单位：
UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
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：
2017-04-01 至 2024-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10133045
关键词：
7-dehydrocholesterol reductase Affect Antibodies Biological Biological Assay Biological Process Bone Development Bone Diseases Calvaria Cellular biology Cholesterol Cholesterol Homeostasis Cilia Code Craniofacial Abnormalities DNA Sequence Alteration Data Defect Deformity Development Diagnosis Diagnostic Diet Early Intervention Endoplasmic Reticulum Enzymes Etiology Exhibits Frontal bone structure Gene Mutation Genes Genetic Diseases Goals Histologic Homeostasis Human Hydroxymethylglutaryl-CoA Reductase Inhibitors Image Immunoprecipitation Impairment Instruction Intervention Knock-out Knockout Mice Limb structure Luciferases Metabolic Methods Molecular Mus Mutation Neural Crest Newborn Infant Osteoblasts Osteogenesis Pathogenesis Patients Pharmaceutical Preparations Pharmacology Play Prevention Prevention approach Proteins Proteomics Reporter Research Reverse Transcriptase Polymerase Chain Reaction Role Sensory Signal Pathway Signal Transduction Simvastatin Skeletal Development Small Interfering RNA Smith-Lemli-Opitz Syndrome Stains Structure Testing Therapeutic Time Transmission Electron Microscopy Vesicle WNT Signaling Pathway Wild Type Mouse bone ciliopathy cilium biogenesis conditional knockout craniofacial craniofacial bone craniofacial development cranium experimental study immunocytochemistry innovation insight lipid biosynthesis microCT mineralization mouse genetics mutant novel osteoblast differentiation osteoblast proliferation osteogenic overexpression preventive intervention public health relevance skeletal tool

项目摘要

Human linkage studies have shown that genetic mutations related to cholesterol metabolism and high maternal cholesterol diets result in craniofacial bone deformities, suggesting that cholesterol metabolic aberrations may be a widely conserved mechanism in craniofacial developmental defects. However, it is still largely unknown how altered cholesterol metabolism causes craniofacial bone abnormalities. Therefore, the objective of this application is to define how cholesterol metabolic aberrations, through disruption of either the Dhcr7 gene (which encodes an enzyme involved in the last step of cholesterol synthesis and is the causative gene for Smith-Lemli-Opitz syndrome) or the Insig1 and Insig2 genes (which provide instructions for endoplasmic reticulum proteins that regulate lipid biosynthesis), cause osteoblast (OB) differentiation abnormalities, and to test the functional significance of downstream target molecules during craniofacial bone formation. The long- term goal of this project is to gain insight into the mechanisms of craniofacial bone formation and provide new medications and diagnostic tools for bone diseases. We will test our working hypothesis by using mouse genetics and cellular biology approaches. In our preliminary studies, we found that: 1) impaired cholesterol synthesis resulted in accelerated bone formation; 2) excess cholesterol synthesis resulted in decreased bone formation; 3) the formation of primary cilia, which play a crucial in sensing cell signals, was altered in OBs from Dhcr7 knockout (KO) and neural crest specific Insig1/2 conditional knockout (cKO) mice; 4) WNT signaling was altered in Dhcr7 KO and Insig1/2 cKO mice; and 5) normalization of cholesterol metabolic aberrations restored craniofacial bone defects in Dhcr7 KO and Insig1/2 cKO mice. Our hypothesis that proper cholesterol metabolism is crucial for normal craniofacial bone formation will be tested in the following specific aims: 1) to determine the role of cholesterol metabolism in craniofacial bone development; and 2) to determine the role of cholesterol metabolism in primary cilium formation in bone. This study will unravel a new mechanism of bone development and homeostasis and will lead to innovative methods of diagnosis, treatment, and prevention of skull deformities.

人类连锁研究表明，基因突变与胆固醇代谢和孕产妇高血脂有关。胆固醇饮食导致颅面骨畸形，表明胆固醇代谢异常可能是颅面发育缺陷中广泛保守的机制。然而，目前仍鲜为人知胆固醇代谢改变如何导致颅面骨异常。因此，本次活动的目的该应用的目的是确定胆固醇代谢异常是如何通过破坏 Dhcr7 基因来实现的。（它编码参与胆固醇合成最后一步的酶，并且是胆固醇合成的致病基因 Smith-Lemli-Opitz 综合征）或 Insig1 和 Insig2 基因（为内质调节脂质生物合成的网状蛋白），导致成骨细胞（OB）分化异常，并测试颅面骨形成过程中下游靶分子的功能意义。长- 该项目的长期目标是深入了解颅面骨形成的机制并提供新的骨疾病的药物和诊断工具。我们将使用鼠标来测试我们的工作假设遗传学和细胞生物学方法。在我们的初步研究中，我们发现：1）胆固醇受损合成导致加速骨形成； 2）胆固醇合成过多导致骨质减少形成； 3）初级纤毛的形成在传感细胞信号中发挥着至关重要的作用，在来自 OB 中发生了改变 Dhcr7 敲除 (KO) 和神经嵴特异性 Insig1/2 条件敲除 (cKO) 小鼠； 4) WNT信号传导是 Dhcr7 KO 和 Insig1/2 cKO 小鼠发生改变； 5) 胆固醇代谢异常恢复正常化 Dhcr7 KO 和 Insig1/2 cKO 小鼠的颅面骨缺陷。我们的假设是适当的胆固醇新陈代谢对于正常颅面骨形成至关重要，将在以下具体目标中进行测试：1）确定胆固醇代谢在颅面骨发育中的作用； 2) 确定角色骨中初级纤毛形成中的胆固醇代谢。这项研究将揭示骨的新机制发展和稳态，并将带来诊断、治疗和预防的创新方法颅骨畸形。