DOWN-REGUL OF BONE MORPHOG PROTEIN-11 BY ITS PROPEPTIDE DURING EMBRYONIC DEV

这个子项目是利用资源的许多研究子项目之一 由NIH/NCRR资助的中心拨款提供。子项目的主要支持 子项目的主要研究者可能是由其他来源提供的， 包括其它NIH来源。 为子项目列出的总成本可能 表示子项目使用的中心基础设施的估计数量， NCRR赠款不直接向子项目或子项目工作人员提供资金。 骨形态发生蛋白11（BMP-11或GDF-11）在氨基酸序列上与肌生长抑制素或GDF-8具有90%的同一性。BMP-11基因敲除小鼠导致椎骨的巨大转变和新生儿的死亡。此外，它可能像肌肉生长抑制素一样调节肌肉质量。然而，BMP-11在胚胎和胎儿阶段调节骨骼形成的具体作用尚未明确。基于我们先前的证据，即转基因表达的肌生长抑制素前肽显着抑制肌生长抑制素功能和增加肌肉质量，我们产生了转基因小鼠，过度表达BMP-11前肽的控制下，成骨细胞特异性启动子。活体动物出生时颈椎转化为胸椎。这种BMP-11前肽小鼠模型为研究BMP-11在肌肉骨骼形成和发育中的作用提供了重要的动物模型。本实验旨在研究BMP-11前肽转基因小鼠胚胎期和胎儿期的骨骼形成和肌肉发生，并进一步研究BMP-11及其前肽在间充质干细胞向成骨和软骨分化的调控中的作用。研究方法将包括转基因小鼠和细胞培养物，体内BrdU标记用于细胞增殖测定，通过qRT-PCR和Western印迹进行基因表达分析。该项目的结果有望揭示胚胎发育过程中控制骨形成的分子和细胞机制，这对于理解骨骼异常和出生缺陷非常重要。这些调控机制的新知识可能有助于开发预防人类出生缺陷的新策略。对我们来说，这个项目的直接好处是获得并公布了准备NIH拨款申请的初步数据。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Bone morphogenetic protein 11 (BMP-11 or GDF-11) has 90% identity in amino acid sequences with myostatin or GDF-8. BMP-11 knockout mice caused dramatic transformation of vertebrae and death of newborns. Also, it may act like myostatin to regulate muscle mass. However, the specific roles of BMP-11 in regulation of skeletal formation during embryonic and fetal stages have not been well defined. Based on our previous evidence that transgenic expression of myostatin propeptide significantly depressed myostatin function and increased muscle mass, we generated transgenic mice that over-express BMP-11 propeptide under the control of an osteoblast-specific promoter. Live animals were born with transformed cervical vertebra to a thoracic vertebra. This BMP-11 propetide mouse model offers an important animal model for studying the role of BMP-11 in musculoskeletal formation and development. This pilot project is designed to characterize skeletal formation and myogenesis of BMP-11 propeptide transgenic mice during the embryonic and fetal periods, and further to investigate the role of BMP-11 and its propeptide in the regulation of differentiation of mesenchymal stem cells to osteogenic and chondrogenic lineage. Research methods will incorporate transgenic mice and cell culture with in vivo BrdU labeling for cell proliferation assay, gene expression analysis by qRT-PCR and Western blotting. Results from this project are expected to reveal molecular and cellular mechanisms that control bone formation during embryo development, which is important for understanding skeletal abnormalities and birth defects. The new knowledge of these regulatory mechanisms may help to develop novel strategies for preventing human birth defects. The immediate, direct benefit of this project for us is to obtain and publish the preliminary data for the preparation of a NIH grant application.