PTH/PTHRP RECEPTORS IN THE BIOLOGY OF ENDOCHONDRAL BONE

软骨内骨生物学中的 PTH/PTHRP 受体

• 批准号: 2146664
• 负责人: GINO V SEGRE
• 金额: $ 36.09万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-01-01 至 1996-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2146664
• 关键词: adenylate cyclase; biological signal transduction; gene expression; hormone receptor; hormone regulation /control mechanism; in situ hybridization; insulinlike growth factor; laboratory mouse; laboratory rat; osteogenesis; osteoporosis; parathyroid hormones; peptide hormone; phospholipase C; transforming growth factors

Precise orchestration of myriad of event is necessary for normal skeletal development and maintenance of its integrity. This proposal focuses on endochondral bone formation and the roles parathyroid hormone (PTH), PTH- related peptide (PTHrP) and PTH/PTHrP receptors play in the complex interrelationships between the PTH/PTHrP system and skeletal growth factors and their receptors, and the several collagens and non- collagenous proteins that are integral to bone biology. PTHrP is essential for normal skeletal maturation, as evidenced by striking abnormalities in mice whose PTHrP gene have been largely deleted by homologous recombination (PTHrP-less). Recently, receptors that bind both PTH and PTHrP have been cloned from several species; they have the unique property of binding both a circulating hormone important to calcium homeostasis, and a presumed paracrine/autocrine peptide with obvious importance to bone biology. These receptors also activate multiple effector molecules, including adenylate cyclase and phospholipase C. Numerous growth factors have also been shown to impact critically on skeletal development and homeostasis; among these, current evidence suggests that members of the insulin-like growth factors (IGFs), transforming growth factor beta (TGFbeta), and bone morphogenetic proteins (BMPs) either regulate, or are regulated by the PTH/PTHrP system. We plan to use a variety of approaches to understand the mechanism by which PTH and PTHrP modulate skeletal expression of genes for these growth factors, and to define influences these growth factors have on PTHrP and PTH/PRHrP receptor mRNA and protein expression. These interrelationships will be explored by both morphological criteria and molecular biological approaches in several systems. Aim I details our initial descriptive analyses to characterize gene expression in late fetal skeletal development in normal rats, rats up to 46 weeks of age, both normal and PTHrP-less fetal mice, and in chondrocytic and osteoblastic cells in primary culture. We have developed systems which we can perturb to analyze these relationships at increasingly complex levels of organization--from primary cells in culture, to organ explants and intact integrating in vitro and in vivo studies, we expect to define mechanisms at the cellular and organ level and relate the relevance of these findings to the whole animal. Aim II mainly analyzes the effects of PTH (1-84) and PTHrP (1-141) on expression of genes for growth factors, several collagens and non-collagenous proteins. Aim III examines the reciprocal relationship; that is, the influences of these growth factors on expression of PTHrP and PTH/PTHrP receptor mRNA and protein. Greater understanding of skeletal homeostasis will, in turn, contribute to bone biology in general and lead to more rational therapy for diseases like osteoporosis.

正常骨骼的精确编排是无数事件的精确编排 其完整性的发展和维护。该提议重点 软骨骨形成和甲状旁腺激素（PTH），PTH- 相关的肽（PTHRP）和PTH/PTHRP受体在复合物中发挥作用 PTH/PTHRP系统与骨骼生长之间的相互关系 因素及其受体，以及几种胶原蛋白和非 - 与骨生物学不可或缺的胶原蛋白。 PTHRP是 正常骨骼成熟至关重 PTHRP基因已在很大程度上被删除的小鼠异常 同源重组（无PTHRP）。 最近，结合的受体 PTH和PTHRP都从几种物种中克隆出来。他们有 结合两种循环激素的独特特性对 钙稳态，以及假定的旁分泌/自分泌肽 对骨骼生物学的重要性很明显。 这些受体也激活 多重效应分子，包括腺苷酸环化酶和 磷脂酶C.也已显示许多生长因子影响 严格的骨骼发育和体内平衡；其中，当前 有证据表明，胰岛素样生长因子（IGF）的成员， 转化生长因子β（TGFBETA）和骨形态发生 蛋白质（BMP）调节或由PTH/PTHRP调节 系统。 我们计划使用各种方法来了解 PTH和PTHRP调节基因骨骼表达的机制 对于这些增长因素，并定义影响这些增长因素 具有PTHRP和PTH/PRHRP受体mRNA和蛋白质表达。 这些 形态标准和 几种系统中的分子生物学方法。 目标我详细介绍了我们的 最初的描述性分析以表征近来的基因表达 正常大鼠的胎儿骨骼发育，最高46周龄的大鼠 正常和无PTHRP的胎儿小鼠，以及软骨细胞和 原代培养物中的成骨细胞。 我们开发了系统 我们可以在日益复杂的情况下扰动分析这些关系 组织的水平 - 从培养中的原代细胞到器官外植体 完整整合体外和体内研究，我们希望定义 细胞和器官水平的机制，并关联 这些发现给整个动物。 AIM II主要分析效果 PTH（1-84）和PTHRP（1-141）的生长基因表达 因素，几种胶原蛋白和非胶原蛋白。 目标三 检查互惠关系；也就是说，这些的影响 PTHRP和PTH/PTHRP受体mRNA和 蛋白质。 对骨骼稳态的更多了解反过来将 总体上有助于骨骼生物学，并导致更多理性的治疗 对于骨质疏松症等疾病。