Role of ERK1/2 in Neuromuscular Synapses and Myofiber Development in vivo

ERK1/2 在体内神经肌肉突触和肌纤维发育中的作用

基本信息

批准号：
8533045
负责人：
MENDELL RIMER
金额：
$ 17.18万
依托单位：
TEXAS A&M UNIVERSITY HEALTH SCIENCE CTR
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-09-01 至 2015-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8533045
关键词：
Actins Address Affect Age Aging Agrin Alleles Animals Apoptosis Behavior Binding Biological Assay Breeding Cell Nucleus Cell physiology Cells Cholinergic Receptors Coffin-Lowry syndrome Complex Data Defect Development Differentiation and Growth Duchenne muscular dystrophy Dystroglycan Ensure Feedback Fiber Financial compensation Fruit Gene Targeting Genetic Glycoproteins Grouping Growth Factor Hindlimb Human In Vitro Investigation LDL-Receptor Related Proteins Lead Link MAPK1 gene MAPK3 gene Maintenance Measures Mediating Mitogen-Activated Protein Kinase 3 Mitogen-Activated Protein Kinases Modeling Molecular Morphology Motor Motor Neurons Mus Muscle Muscle Fibers Muscle-Specific Kinase Myopathy Neonatal Nerve Nervous system structure Neuromuscular Junction Pathway interactions Peripheral Nervous System Phenotype Play Process Protein Kinase Reporting Role Signal Transduction Skeletal Muscle Spinal Cord Staging Sternocleidomastoid Muscle Structure Synapses Testing Time Ursidae Family cell type cytokine disease-causing mutation grasp in vivo inhibitor/antagonist insight mature animal mdx mouse neuromuscular normal aging postsynaptic presynaptic promoter receptor recombinase research study ribosomal protein S6 kinase 2 skeletal skeletal muscle differentiation synaptogenesis young adult

Actins Address Affect Age Aging Agrin Alleles Animals Apoptosis Behavior Binding Biological Assay Breeding Cell Nucleus Cell physiology Cells Cholinergic Receptors Coffin-Lowry syndrome Complex Data Defect Development Differentiation and Growth Duchenne muscular dystrophy Dystroglycan Ensure Feedback Fiber Financial compensation Fruit Gene Targeting Genetic Glycoproteins Grouping Growth Factor Hindlimb Human In Vitro Investigation LDL-Receptor Related Proteins Lead Link MAPK1 gene MAPK3 gene Maintenance Measures Mediating Mitogen-Activated Protein Kinase 3 Mitogen-Activated Protein Kinases Modeling Molecular Morphology Motor Motor Neurons Mus Muscle Muscle Fibers Muscle-Specific Kinase Myopathy Neonatal Nerve Nervous system structure Neuromuscular Junction Pathway interactions Peripheral Nervous System Phenotype Play Process Protein Kinase Reporting Role Signal Transduction Skeletal Muscle Spinal Cord Staging Sternocleidomastoid Muscle Structure Synapses Testing Time Ursidae Family cell type cytokine disease-causing mutation grasp in vivo inhibitor/antagonist insight mature animal mdx mouse neuromuscular normal aging postsynaptic presynaptic promoter receptor recombinase research study ribosomal protein S6 kinase 2 skeletal skeletal muscle differentiation synaptogenesis young adult

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项目摘要

DESCRIPTION (provided by applicant): Extracellular-signal regulated kinases 1 and 2 (ERK1/2) are the prototypical intracellular mitogen activated protein kinases (MAPK). ERK1/2 are activated by multiple growth factors and cytokines in many cell types. Studies in vitro implicate ERK1/2 in a myriad of cellular processes during proliferation, differentiation and apoptosis. ERK activity has both stimulatory and inhibitory roles in the differentiation of culture skeletal myotubes that vary with the stage of this protracted process. However, no gene targeting investigations on the role of ERK1/2 in developing muscle fibers in vivo have been reported to date. Agrin released by motoneurons induces and/or maintains acetylcholine receptor (AChR) clustering and other aspects of postsynaptic differentiation at the vertebrate neuromuscular junction (NMJ), the synapse between a motoneuron in the spinal cord and a skeletal muscle fiber. Agrin acts by binding and activating a receptor complex containing LDL receptor related protein 4 (Lrp4) and muscle specific kinase (MuSK). We reported recently that in cultured myotubes agrin induces ERK1/2 activation in an Lrp4/MuSK-dependent fashion and that this negatively regulates the ability of agrin to induce AChR clusters. Furthermore, our preliminary data show that loss of ERK2 in myofibers leads to defects in NMJ maintenance in young adult mice. In these animals, NMJs display fragmentation similar to than seen in NMJs of old mice or in mdx mice, which model Duchenne muscular dystrophy. The aim of this R21 application is to investigate the significance in vivo of ERK1/2 for neuromuscular synapse formation and maintenance and for skeletal myofiber differentiation and maturation. A strategy of conditional gene targeting that has recently bear fruit in other cells of the peripheral nervous system will be used to selectively inactivate Erk1/2 in skeletal muscle fibers. Results from the above experiments will clarify the in vivo role of ERK1/2 in agrin signaling at the NMJ, in particular, and in the development of skeletal muscle fibers, in general. In addition, they may provide new insights into the molecular mechanisms underlying normal aging, Duchenne muscular dystrophy and diseases caused by mutation of ERK1/2 downstream substrates expressed in muscle, such as ribosomal S6 kinase 2 (Rsk2), which is linked to Coffin-Lowry syndrome.

描述（由申请人提供）：细胞外调节的激酶1和2（ERK1/2）是原型的细胞内丝分裂原活化蛋白激酶（MAPK）。 ERK1/2在许多细胞类型中被多种生长因子和细胞因子激活。体外研究暗示了在增殖，分化和凋亡过程中无数细胞过程中ERK1/2的研究。 ERK活性在随着旷日持久过程的阶段变化的培养骨骼肌管的分化中具有刺激性和抑制作用。然而，迄今为止，尚无针对ERK1/2在体内发育肌肉纤维中的作用的基因研究。由运动神经元释放的Agrin诱导和/或维持乙酰胆碱受体（ACHR）聚类以及脊椎动物神经肌肉连接（NMJ）的突触后分化的其他方面，脊髓中的运动神经元与骨骼肌纤维之间的运动神经元之间的突触。 Agrin通过结合和激活含有LDL受体相关蛋白4（LRP4）和肌肉特异性激酶（MUSK）的受体复合物来起作用。我们最近报道说，在培养的肌管中，Agrin以LRP4/Musk依赖性方式诱导ERK1/2激活，并且这对Agrin诱导ACHR簇的能力进行负调节。此外，我们的初步数据表明，肌纤维中ERK2的损失会导致年轻小鼠NMJ维持的缺陷。在这些动物中，NMJ的碎裂性与旧小鼠的NMJ或MDX小鼠的NMJ相似，这些小鼠模拟了Duchenne肌肉营养不良。该R21应用的目的是研究ERK1/2的体内显着性在神经肌肉突触的形成和维持以及骨骼肌纤维的分化和成熟。一种有条件基因靶向的策略，该策略最近在周围神经的其他细胞中带有果实系统将用于在骨骼肌纤维中有选择地使ERK1/2灭活。上述实验的结果将阐明ERK1/2在NMJ的Agrin信号传导中的体内作用，尤其是在骨骼肌纤维的发展中。此外，它们可能会提供有关正常衰老，Duchenne肌肉营养不良的分子机制和由肌肉中表达的ERK1/2下游底物突变引起的疾病的分子机制，例如核糖体S6激酶2（RSK2），这些底物与棺材 - 脂肪酶2（RSK2）相关。