Role of Transcription Factor ERG in Skeletogenesis

转录因子 ERG 在骨骼发生中的作用

• 批准号: 7217993
• 负责人: Maurizio Pacifici
• 金额: $ 33.11万
• 依托单位: THOMAS JEFFERSON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-04-15 至 2011-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7217993
• 关键词: A Mouse; Ablation; Adult; Affect; Aging; Agreement; Biological; Bone Marrow Cells; Cartilage; Cell Line; Cell Surface Receptors; Cell Therapy; Cells; Chondrocytes; Cloning; Complex; Condition; Data; Defect; Degenerative polyarthritis; Development; Down-Regulation; ERG gene; Elements; Embryo; Epiphysial cartilage; Exhibits; Family; Family member; Funding; Future; Gene Expression; Genes; Growth; Human; Hypertrophy; Individual; Joints; Knockout Mice; Knowledge; Lead; Life; Limb structure; Maintenance; Molecular; Mus; Neonatal; Organ Culture Techniques; Osteoarthrosis Deformans; Osteogenesis; Other Finding; Partner in relationship; Pathology; Patients; Pattern; Phenotype; Phosphorylation; Population; Property; RNA Splicing; Regulation; Reporter; Research Personnel; Role; Signal Pathway; Signaling Molecule; Skeletal system; Smad Proteins; Smad protein; Staging; Stem cells; Stream; Structure; Testing; Therapeutic; Transgenic Mice; Transgenic Organisms; Variant; articular cartilage; base; bone; functional restoration; gain of function; growth differentiation factor 5; insight; long bone; member; mouse model; postnatal; prevent; programs; promoter; recombinase; response; transcription factor

DESCRIPTION (provided by applicant): During limb skeletogenesis chondrocytes follow two developmental paths and produce permanent articular cartilage persisting through life or transient growth plate cartilage in which the cells mature, hypertrophy, and are replaced by bone. Though the critical importance of this developmental bifurcation for skeletal formation and function is widely recognized, the underlying mechanisms of regulation remain unclear, particularly at the molecular level. In the previous funding period, we focused on the transcription factor ERG and its variant C-1-1. Gain-of-function studies with chick and human C-1-1 show that: (a) C-1-1 is able to impose a stable and articular-like phenotype over the entire limb chondrocyte population, blocking growth plate formation, chondrocyte maturation and bone formation; (b) C-1-1 counteracts action of the pro-maturation transcription factor Runx2; and (c) the joint master regulator GDF-5 rapidly induces ERG/C-1-1 expression in developing synovial joints. These and other findings lead to our central hypotheses for this competitive continuation proposal: (a) C-1-1 acting down-stream of GDF-5 contributes to formation of permanent articular chondrocytes; and (b) C-1-1 in turn inhibits Runx2 function, maintains the permanent status of the cells, and prevents maturation and hypertrophy. Our aims are: (i) to functionally characterize murine ERG variants by cell and explant cultures and transgenic approaches; (ii) determine the consequences of conditional ERG gene ablation during development or postnatal life, using GDF-5-Cre and GDF-5-CreER mice; and (iii) determine the mechanisms by which GDF-5 triggers ERG expression by signaling pathways and promoter action, and how ERG/C-1-1 inhibits Runx2 function. The project will produce fundamental insights into genesis and function of articular chondrocytes. It should also generate mouse models of degenerative joint disease that could be used to test future gene- and cell-based therapies for joints conditions common to osteoarthritic patients and aging individuals.

描述（由申请人提供）：在肢体骨骼发生过程中，软骨细胞遵循两种发育路径，并产生终生持续的永久关节软骨或短暂生长的板软骨，其中细胞成熟、肥大并被骨取代。尽管这种发育分叉对于骨骼形成和功能的至关重要性已得到广泛认可，但其潜在的调节机制仍不清楚，特别是在分子水平上。在之前的资助期间，我们重点关注转录因子ERG及其变体C-1-1。对鸡和人 C-1-1 进行的功能获得研究表明： (a) C-1-1 能够对整个肢体软骨细胞群施加稳定的关节样表型，阻止生长板形成、软骨细胞成熟和骨形成； (b) C-1-1 抵消促成熟转录因子 Runx2 的作用； (c) 关节主调节因子 GDF-5 在发育中的滑膜关节中快速诱导 ERG/C-1-1 表达。这些和其他发现引出了我们对这一竞争性延续提案的中心假设：(a) C-1-1 作用于 GDF-5 下游，有助于永久关节软骨细胞的形成； (b) C-1-1 反过来抑制 Runx2 功能，维持细胞的永久状态，并防止成熟和肥大。我们的目标是：（i）通过细胞和外植体培养以及转基因方法对小鼠 ERG 变异进行功能表征； (ii) 使用 GDF-5-Cre 和 GDF-5-CreER 小鼠确定发育或出生后生活期间条件性 ERG 基因消融的后果； (iii) 确定 GDF-5 通过信号通路和启动子作用触发 ERG 表达的机制，以及 ERG/C-1-1 如何抑制 Runx2 功能。该项目将对关节软骨细胞的起源和功能产生基本的见解。它还应该产生退行性关节疾病的小鼠模型，可用于测试未来针对骨关节炎患者和老年人常见关节疾病的基因和细胞疗法。