INTRACELLULAR SIGNALING OF BONE MORPHOGENETIC PROTEINS

骨形态发生蛋白的细胞内信号转导

• 批准号: 6124159
• 负责人: HUI-CHUAN C HUANG
• 金额: $ 24.4万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-01-01 至 2002-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6124159
• 关键词: DNA footprinting; Xenopus; alternatives to animals in research; biological signal transduction; bone development; bone morphogenetic proteins; cell line; gel mobility shift assay; gene expression; gene induction /repression; gene interaction; genetic promoter element; genetic regulation; human tissue; molecular cloning; osteogenesis; osteoporosis; polymerase chain reaction; protein protein interaction; protein structure function; tissue /cell culture; transcription factor; yeast two hybrid system

Osteoporosis is a common disease among the elderly, especially in postmenopausal women. Current treatments for osteoporosis are aimed at inhibiting bone resorption. Thus, treatments that promote bone formation could provide a major improvement in the therapy of osteoporosis. Bone morphorgenetic proteins (BMPs) are able to induce ectopic bone formation and have been proposed as possible agents to stimulate new bone formation in patients with osteoporosis. Downstream components of the BMP signaling pathway may also serve as targets for therapy in osteoporosis, but little is known about how BMPs signal from the cytoplasm to the nucleus, particularly how they activate gene expression in responsive cells. Our long term goals are to use the molecules we identify in Xenopus to characterize BMP regulated gene expression in other BMP responsive tissues, particularly osteogenic precusors, and to explore these molecules as potential therapeutic targets in the treatment of osteoporosis. Xenopus embryos will be used for much of the experiments described here, since they have provided a highly successful model system for the study of other BMP functions as well as the characterization of activin/TGF-beta regulated gene expression. The specific goals of this proposal are to determine the promoter sequences that mediate Mix.2 gene expression in response to BMP-4 in Xenopus laevis and to characterize the transcription factors that interact with these sequences. Our preliminary evidence suggests a direct role for Smad proteins in the induction of the Mix.2 gene, and this role will be further explored by characterizing the interactions between Smad genes, BMP-4 regulated transcription factors, and the DNA elements within the BMP-4 regulated promoter. Several novel genes have been identified in a yeast two-hybrid screen that interact with the Smad1 protein. These clones will be characterized further by examining their patterns of expression and their ability to interact in vivo with Smad1 and/or transcription factor complexes regulating Mix.2 gene expression. In future studies, these proteins characterized from Xenopus will be identified in mammalian tissues, particularly osteogenic precursor cells, and examined for their roles in mediating bone formation in mammals in response to BMPs.

骨质疏松症是老年人的常见疾病，特别是 绝经后妇女。目前对骨质疏松症的治疗方法是 旨在抑制骨吸收。 因此，治疗 促进骨形成可以为 骨质疏松症的治疗。 骨形态蛋白（BMP）是 能够诱导异位骨形成，并已被提出为 可能刺激患者患者的新骨形成的药物 骨质疏松症。 BMP信号通路的下游组件 也可能是骨质疏松症治疗的靶标 知道BMPS从细胞质到细胞核的信号如何知道， 特别是它们如何激活反应性基因表达 细胞。 我们的长期目标是使用我们确定的分子 在Xenopus中以表征BMP调节的基因表达 BMP响应性组织，特别是成骨的预驱动器，以及 探索这些分子作为潜在的治疗靶标 治疗骨质疏松症。 Xenopus胚胎将用于很多 在此处描述的实验中，因为它们提供了 用于研究其他BMP的高成功模型系统 功能以及激活素/TGF-beta的表征 调控基因表达。 该提议的具体目标 确定介导混合的启动子序列。2基因 反应于Xenopus laevis中BMP-4的表达 表征与这些相互作用的转录因子 序列。我们的初步证据表明 诱导混合物中的Smad蛋白2基因，该作用 通过表征互动来进一步探索 在SMAD基因，BMP-4调节的转录因子和 BMP-4调控启动子内的DNA元素。 一些 新型基因已在酵母双杂交筛选中鉴定出来 与Smad1蛋白相互作用。 这些克隆将是 通过检查其表达方式进一步表征 以及他们与Smad1和/或体内互动的能力 转录因子复合物调节混合物2基因表达。 在以后的研究中，这些以爪蟾为特征的蛋白质将 可以在哺乳动物组织中鉴定，尤其是成骨 前体细胞，并检查其在介导骨中的作用 哺乳动物响应BMP的形成。