RAMP Involvement in PTH Regulation of Bone Metabolism

描述（由申请人提供）：本拟议研究的目标是为主要研究者Jeanne M. Nerve，DMD，博士，有机会发展成为一名独立的研究人员，以补充她在药理学方面的临床培训。她的培训将在项目赞助商Sotirios Tetradis博士和Harvey Herschman博士的指导下进行。Nerve博士的职业目标是追求学术生涯，并建立自己作为一个独立的牙医科学家进行分子生物学研究，指导各级学生，并实践牙科学。 骨质量和数量是口面病理学的重要指标，也是许多牙科手术成功的预测因子。骨形成成骨细胞和骨吸收破骨细胞的解偶联活性在骨代谢中产生显著变化。我们的基本原理是，了解骨代谢的分子机制将极大地影响医学和牙科。甲状旁腺激素（PTH）对骨具有显著的合成代谢作用，但我们不了解这些作用的分子介质。我们已经确定受体活性修饰蛋白3（RAMP3）作为PTH诱导的小鼠成骨细胞的主要基因。在初步研究中，我们发现PTH也调节小鼠成骨细胞中RAMP1的mRNA水平，但不调节RAMP2。RAMP 1、2和3是降钙素和降钙素受体样受体的关键共活化剂。这些受体的配体对骨具有显著的合成代谢作用。我们假设RAMP蛋白参与甲状旁腺激素对成骨细胞的合成代谢作用。为了验证我们的假设，我们提出了三个具体目标。(1)我们将在体外和体内表征PTH诱导的RAMP1和RAMP3基因在小鼠成骨细胞中的表达。(2)将产生表达RAMP1和RAMP3的腺病毒以评估这些基因在调节成骨细胞表型中的作用。(3)将使用COL1A1启动子产生RAMP1和RAMP3转基因小鼠，以将转基因表达靶向成骨细胞。将在大体、细胞和分子水平上研究各小鼠系的骨表型变化。这些研究将有助于我们了解PTH诱导RAMP1和RAMP3基因表达的机制，并揭示这些基因对成骨细胞功能的影响。

DESCRIPTION (provided by applicant): The goal of this proposed study is to provide the Principal Investigator, Jeanne M. Nervina, DMD, PhD, with the opportunity to develop as an independent researcher to complement her clinical training in orthodontics. Her training will be conducted under the guidance of the project's sponsors, Dr, Sotirios Tetradis and Dr. Harvey Herschman. Dr. Nervina's career goal is to pursue an academic career and establish herself as an independent dentist scientist conducting molecular biology research, mentoring students at all levels, and practicing orthodontics. Bone quality and quantity are important indicators of orofacial pathology and are predictors of outcome success for many dental surgical procedures. Uncoupled activity of bone forming osteoblasts and bone resorbing osteoclasts produce significant changes in bone metabolism. Our rationale is that understanding the molecular mechanisms of bone metabolism will greatly impact medicine and dentistry. Parathyroid hormone (PTH) has significant anabolic effects on bone, yet we do not understand the molecular mediators of these effects. We have identified receptor activity modifying protein 3 (RAMP3) as a PTH-induced primary gene in mouse osteoblasts. In preliminary studies we found that PTH also regulates RAMP1, but not RAMP2, mRNA levels in mouse osteoblasts. RAMP1, 2, and 3 are critical coactivators of calcitonin and calcitonin receptor-like receptors. Ligands for these receptors have significant anabolic effects on bone. We hypothesize that RAMP proteins participate in PTH's anabolic effect on osteoblasts. To test our hypothesis we propose three Specific Aims. (1) We will characterize PTH-induced RAMP1 and RAMP3 gene expression in mouse osteoblasts in vitro and in vivo. (2) Adenoviruses expressing RAMP1 and RAMP3 will be generated to assess the role of these genes in regulating osteoblast phenotype. (3) RAMP1 and RAMP3 transgenic mice will be generated using the COL1A1 promoter to target transgene expression to osteoblasts. Each mouse line will be studied for changes in bone phenotype at the gross, cellular, and molecular levels. These studies will help us understand the mechanisms of PTH-induced RAMP1 and RAMP3 gene expression and they will unveil the impact of these genes on osteoblast function.