Effects of nuclear PTHrP on bone formation and the skeletal microenvironment

核PTHrP对骨形成和骨骼微环境的影响

• 批准号: 7918106
• 负责人: Blake Eason Hildreth
• 金额: $ 6.32万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-01 至 2012-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7918106
• 关键词: Address; Adipocytes; Amino Acids; Anabolic Agents; Biological Markers; Biology; Bone Marrow; Bone Marrow Transplantation; Cell Nucleus; Cell Proliferation; Chondrocytes; Disease; Endocrine; Engineering; Engraftment; Gene Expression; Genes; Goals; Hematology; Hematopoietic Stem Cell Mobilization; Hematopoietic stem cells; Hypercalcemia of Malignancy; In Vitro; Knock-in Mouse; Knowledge; Lead; Length; Measures; Modeling; Mus; N Domain; N-terminal; Nuclear; Orthopedics; Osteoblasts; Osteogenesis; Osteoporosis; Parathyroid Hormone Receptor; Parathyroid Hormones; Phenotype; Physiological Processes; Play; Protein Biosynthesis; Proteins; Public Health; Regulation; Regulator Genes; Reporting; Role; Sequence Deletion; Site; Stromal Cells; System; Transplantation; Wild Type Mouse; analog; autocrine; bone; genetic regulatory protein; human PTH protein; in vivo; indexing; intramembranous bone formation; oncology; osteogenic; paracrine; parathyroid hormone-related protein; premature; protein expression; receptor; self-renewal; skeletal; stem cell niche

DESCRIPTION (provided by applicant): Parathyroid hormone (PTH)-related protein (PTHrP) was first discovered as the causative agent of humoral hypercalcemia of malignancy (HHM) through the interaction of its amino-terminus (N-terminus) with the PTH/PTHrP receptor (PTH1R). Since then, PTHrP has been implicating in regulating bone formation and the commitment of BM stromal cells (BMSC) to the osteoblastic lineage, which has led to the use of the N-terminal domain of PTH in the management of osteoporosis. In the hematopoietic stem cell (HSC) niche, activation of the PTH1R on osteoblasts promotes HSC activity and the application of N-terminal PTH in BM transplantation. While both bone formation and HSC niche regulation are attributed to the N-terminus, no information exists regarding the role of other domains of PTHrP. Since several functions of PTHrP are attributed to the nuclear localization sequence (NLS), we have created a mouse lacking the NLS of PTHrP. The objectives of this proposal are to investigate the role of nuclear PTHrP on bone formation and the skeletal microenvironment, namely the HSC niche, of which three specific aims are proposed. First, determine the role of nuclear PTHrP on osteogenesis in vitro, by measuring indices of osteogenic, adipogenic, myogenic, and chondrogenic differentiation of BMSC, and in vivo by measuring the effects of PTHrP analogs on bone formation. Second, examine the role of nuclear PTHrP on skeletal microarchitecture, protein synthesis, and gene expression by assessing microstructural indices at sites of endochondral and intramembranous ossification, its interaction with bone regulatory proteins, and the expression of bone regulatory genes. Third, determine the role of nuclear PTHrP in the regulation of the HSC niche by measuring the expression of associated genes in BMSC and HSC and enumerating BM HSC. We hypothesize that the NLS is necessary and additive to the effects of N-terminal PTHrP in bone formation and skeletal microenvironment regulation. Findings will warrant investigating the use of NLS-containing PTHrP analogs, which could have significant implications in orthopedics, oncology and hematology. Relevance to public health: PTHrP is a protein similar to PTH, which is the only proven therapy for osteoporosis. Unlike PTH, PTHrP has a region called the NLS, which takes the protein to the cell nucleus and may contribute to PTHrP's more widespread effects. We will investigate the role of the NLS in bone formation and skeletal microenvironment regulation using a mouse lacking the NLS of PTHrP, which may lead to the use of NLS-containing PTHrP analogs as both a skeletal anabolic agent and for HSC expansion in BM transplantation and related disorders.

描述（由申请人提供）：首先通过与PTH/PTHRP受体（PTHP受体（N-末端）的相互作用）相互作用，首先发现了甲状旁腺激素（PTH）相关蛋白（PTHRP）作为恶性（HHM）的体液高钙血症（HHM）的病因（HHM）。从那时起，PTHRP与调节骨形成以及BM基质细胞（BMSC）对成骨细胞谱系的承诺有关，这导致了PTH的N末端结构域在骨质疏松症的管理中。在造血干细胞（HSC）小裂中，PTH1R在成骨细胞上的激活促进了HSC活性和N末端PTH在BM移植中的应用。虽然骨形成和HSC生态位调节都归因于N末端，但尚无有关PTHRP其他域的作用的信息。由于PTHRP的几个函数归因于核定位序列（NLS），因此我们创建了缺乏PTHRP NLS的小鼠。该提案的目标是研究核PTHRP在骨形成和骨骼微环境中的作用，即HSC利基市场，其中提出了三个特定目标。首先，通过测量BMSC的成骨，成脂，肌生成和软骨分化的指标，确定核PTHRP在体外成骨的作用，并通过测量PTHRP类似物对骨形成的影响。其次，通过评估核PTHRP对骨骼微体系结构，蛋白质合成和基因表达的作用，通过评估内软骨内和膜内骨化位点的微观结构指数，其与骨调节蛋白的相互作用以及骨调节基因的表达。第三，通过测量BMSC和HSC中相关基因的表达以及列举BM HSC来确定核PTHRP在HSC生态位调节中的作用。我们假设NLS对N端PTHRP在骨形成和骨骼微环境调节中的影响是必要的，并且是添加的。调查结果将保证研究含NLS的PTHRP类似物的使用，这可能对骨科，肿瘤学和血液学具有重要意义。与公共卫生相关：PTHRP是一种类似于PTH的蛋白质，这是骨质疏松症的唯一经过验证的疗法。与PTH不同，PTHRP具有称为NLS的区域，该区域将蛋白质带到细胞核，并可能有助于PTHRP更广泛的影响。我们将使用缺乏PTHRP NLS的小鼠来研究NLS在骨形成和骨骼微环境调节中的作用，这可能导致使用含NLS的PTHRP类似物作为骨骼合代代谢剂，既是BM移植和相关障碍者的HSC扩展。