DEVELOPMENTAL REGULATION OF HUMAN MUSCLE PROTEINS

我们的长期目标是增加我们对这些机制的了解 潜在的正常肌肉发育。从最近的研究来看，很明显 肌肉在体内的发育伴随着从 胚胎型到成年型蛋白质。在建议的研究中，我们会 检查这种发育调节基因表达的要求 培养的人肌肉细胞中的肌肉同工酶。具体地说， 人肌肉卫星细胞(肌肉前体细胞)的潜能 表达胎儿和/或成人形式的糖原磷酸化酶和肌球蛋白意志 在取自胎儿和成人肌肉的培养中进行检测。 第一，生化和免疫学方法检测和 肌球蛋白同工酶和磷酸化酶的特征 人类肌肉发育的各个阶段都将得到完善。对以下各项的要求 然后将在培养的肌肉中检测成年肌肉同工酶的表达。 从胎儿和成人肌肉组织中分离出卫星细胞。检视 这些细胞的内在分化程序，发育 同工酶的表达将在纯肌肉培养中表现出来。至 观察神经调节对同工酶表达的潜在影响， 将利用神经-肌肉共培养。 这些实验将建立允许表达 成人肌肉蛋白质。它们还被设计用于确定是否 胎儿和成人肌肉的卫星细胞在肌肉类型上有所不同 它们表达的功能以及成熟同工酶的潜力 随着发育的发展，基因的表达增加。由于卫星细胞扮演着 在体内肌肉的发育和再生中起着关键作用， 了解卫星细胞的潜力是特别有意义的。 此外，正常卫星细胞功能的描绘可能会导致 了解人类肌肉营养不良的病因学 电池可能有缺陷。最后，诱导肌肉的能力 正常肌肉培养中的磷酸化酶应有助于分析 在体酶活性失活的主要缺陷 麦卡德氏病(肌磷酸酶缺乏症)。

Our long-range goal is to increase our understanding of the mechanisms underlying normal muscle development. From recent studies, it is clear that the developement of muscle in vivo is accompanied by a transition from embryonic-type to adult-type proteins. In the proposed studies, we will examine the requirements for expression of such developmentally regulated muscle isozymes in cultured human muscle cells. Specifically, the potential of human muscle satellite cells (muscle precursor cells) to express fetal and/or adult forms of glycogen phosphorylase and myosin will be examined in cultures derived from fetal and adult muscle. First, biochemical and immunological methods for detecting and characterizing the phosphorylase ans myosin isozymes typical of different stages of human muscle development will be perfected. Requirements for adult muscle isozyme expression will then be examined in cultured muscle satellite cells isolated from fetal and adult muscle tissues. To examine the intrinsic program of differentiation in these cells, developmental isozyme expression will be characterized in pure muscle cultures. To observe potential effects of neuronal modulation on isozyme expression, nerve-muscle co-cultures will be utilized. These experiments will establish conditions which permit expression of adult muscle proteins. They are also designed to determine whether the satellite cells of fetal and adult muscle differ in the type of muscle functions they express and whether the potential for mature isozyme expression increases with development. Since satellite cells play a critical role in both the development and regeneration of muscle in vivo, an understanding of satellite cell potential is of particular interest. Furthermore, delineation of normal satellite cell function may lead to an understanding of the etiology of human muscular dystrophies in which these cells may be defective. Finally, the ability to induce muscle phosphorylase in normal muscle cultures should facilitate analysis of the primary defect responsible for the failure in enzyme activity in vivo in McArdle's Disease (myophosphorylase deficiency).