MYOTONIC DYSTROPHY KINASE IN MYOCYTE DEVELOPMENT

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。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 这项研究的目的是确定人类强直性肌营养不良蛋白激酶(DMPK)在心肌细胞发育中的功能。DMPK最初是通过检测位于强直性肌营养不良(DM1)患者DMPK基因3‘非翻译区的CTG三联体重复序列来识别的。在明确DMPK的功能之前，不能确定DMPK表达减少在DM1的病理生理学中的作用。我们的初步数据表明，DMPK可能调节心肌细胞的发育。当增殖细胞转化为有丝分裂后细胞时，DMPK在发育中的心肌细胞中表达。在HeLa细胞中的过表达研究表明，DMPK足以扰乱细胞周期。在培养的小鼠成肌细胞(C2C12细胞)中DMPK的缺失抑制了向肌管的分化，并改变了细胞的形态。我们将检验DMPK在肌肉发生中起关键作用的新假说。DMPK是肌源性基因表达所必需的，并足以在成肌细胞中提前诱导肌源性基因的表达。目的1验证DMPK是心肌细胞分化所必需的，并足以诱导心肌细胞提前分化的假说。目标2将检验DMPK启动退出细胞周期的假设。目的3将验证DMPK是未成熟成肌细胞分化所必需的假说。总之，这些实验将有助于了解DMPK在肌肉细胞发育中的作用，并将为在完全了解DM1肌细胞病理生理学的基础上治疗DM1奠定基础。

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. The goal of the proposed study is to identify the function of human myotonic dystrophy protein kinase (DMPK) in myocyte development. DMPK was originally identified by the detection of a CTG triplet repeat sequence located in the 3' untranslated region of the DMPK gene that is expanded in patients with myotonic dystrophy (DM1). A role for the reduced DMPK expression in the pathophysiology of DM1 cannot be determined until the function of the kinase has been clearly defined. Our preliminary data suggests DMPK may regulate myocyte development. DMPK is expressed in developing myocytes when proliferating cells transition into postmitotic cells. Overexpression studies in HeLa cells demonstrate that DMPK is sufficient to disrupt the cell cycle. The depletion of DMPK in cultured mouse myoblasts (C2C12 cells) inhibits differentiation into myotubes and alters cell morphology. We will test the novel hypothesis that DMPK has a key role in myogenesis. DMPK is required for myogenic gene expression and is sufficient to prematurely induce myogenic gene expression in myoblasts. Aim 1 will test the hypothesis that DMPK is necessary for myocyte differentiation and is sufficient to induce premature myocyte differentiation. Aim 2 will test the hypothesis that DMPK initiates exit from the cell cycle. Aim 3 will test the hypothesis that DMPK is required for the differentiation of immature myoblasts. Together, these experiments will lead to an understanding of DMPK function in muscle cell development and will lay the groundwork for treatments for DM1 based on a complete understanding of DM1 myocyte pathophysiology.