BetaCatenin Regulation of Skeletal Muscle Hypertrophy

β连环蛋白对骨骼肌肥大的调节

• 批准号: 8500216
• 负责人: Karyn A Esser
• 金额: $ 31.74万
• 依托单位: UNIVERSITY OF KENTUCKY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-01 至 2017-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8500216
• 关键词: Adult; Aging; Atrophic; Attenuated; Bed rest; Biochemical; Biogenesis; Biology; Body Weight; Cachexia; Cartoons; Catabolism; Cells; Clinical; Complement; DNA; DNA Polymerase I; DNA-Directed RNA Polymerase; Electrophoretic Mobility Shift Assay; Event; Fiber; Gene Expression; Gene Silencing; Genes; Genetic Transcription; Growth; Health; Hindlimb Suspension; Housing; Human; Hypertrophy; In Vitro; Insulin-Like Growth Factor I; Knowledge; Laboratories; Malignant Neoplasms; Measurement; Measures; Mechanics; Metabolic; Modeling; Molecular; Molecular Target; Morbidity - disease rate; Mus; Muscle; Muscle Cells; Muscle Fibers; Muscle Proteins; Muscular Atrophy; Outcome; Pathway interactions; Plantaris muscle; Protein Biosynthesis; Proteins; Publishing; Quality of life; RNA; Regulation; Research; Reverse Transcriptase Polymerase Chain Reaction; Ribosomal RNA; Ribosomes; Rodent; Role; Skeletal Muscle; Stimulus; System; Testing; Translations; Weight; Western Blotting; Work; c-myc Genes; cell growth; chromatin immunoprecipitation; in vitro Model; in vivo; macromolecule; mortality; muscle form; muscle hypertrophy; muscle strength; novel; novel strategies; overexpression; prevent; promoter; protein degradation; research study; response; sedentary

DESCRIPTION (provided by applicant): As the "house-building" macromolecule of the cell, ribosome biogenesis is essential for cell growth. Despite this central role in cell growth, there remains a fundamental gap in our understanding of the role of ribosome biogenesis in adult skeletal muscle hypertrophy. Studies from our laboratory have provided evidence which supports a role for increased ribosome biogenesis in skeletal muscle hypertrophy. The current proposal will begin to directly examine the importance of ribosome biogenesis to muscle hypertrophy by testing the hypothesis that -catenin is necessary for muscle hypertrophy by increasing protein synthesis through c-myc activation of ribosome biogenesis. To conditionally, manipulate -catenin or c-myc gene expression in adult skeletal muscle we generated the HSA-MerCreMer mouse. Aim 1 will determine if ¿-catenin expression is necessary for skeletal muscle hypertrophy using a mechanical overload model of the plantaris muscle following catenin gene inactivation. Aim 2 will determine if increased expression of ¿-catenin is sufficient to stimulate skeletal muscle hypertrophy. ¿-catenin will be over-expressed in adult skeletal muscle by using the HSA- MerCreMer strain to generate a stabilized form of ¿-catenin. Aim 3 will determine if c-myc expression is necessary for skeletal muscle hypertrophy following the conditional inactivation of c-myc in adult skeletal muscle using the HSA-MerCreMer strain. The effect of gene inactivation on the hypertrophic response will be assessed by measuring morphometric (muscle weight, fiber CSA), biochemical (total protein, RNA and DNA), molecular (Western blot, RT-PCR, promoter analysis, chromatin immunoprecipitation (ChIP) and electrophorectic mobility shift assay (EMSA)) and metabolic (rates of protein synthesis and degradation) variables. The results of the proposed studies are expected to have important clinical implications by identifying new molecular targets for promoting skeletal muscle protein synthesis and hypertrophy. In the long- term, the ability to manipulate ribosome biogenesis represents a promising novel strategy to attenuate or ameliorate muscle atrophy associated with aging, bed rest and cachexia.

描述（申请人提供）：作为细胞的“造房”大分子，核糖体生物合成对细胞生长至关重要。尽管核糖体在细胞生长中起着重要作用，但我们对核糖体生物合成在成人骨骼肌肥大中的作用的理解仍然存在根本性的差距。我们实验室的研究提供了支持骨骼肌肥大中核糖体生物合成增加的证据。目前的建议将开始直接检查的重要性，核糖体生物合成肌肉肥大的假设，-连环蛋白是必要的肌肉肥大通过增加蛋白质合成，通过c-myc激活核糖体生物合成。为了有条件地操纵β-连环蛋白或c-myc基因在成人骨骼肌中的表达，我们产生了HSA-MerCreMer小鼠。目的1将使用在连环蛋白基因失活后的跖肌的机械过载模型来确定连环蛋白表达是否是骨骼肌肥大所必需的。目的2将确定增加的连环蛋白表达是否足以刺激骨骼肌肥大。通过使用HSA-MerCreMer菌株产生稳定形式的β-连环蛋白，β-连环蛋白将在成人骨骼肌中过表达。目的3将确定是否c-myc表达是必要的骨骼肌肥大后，在成人骨骼肌中使用HSA-MerCreMer株的c-myc的条件性失活。将通过测量形态学（肌肉重量、纤维CSA）、生物化学（总蛋白、RNA和DNA）、分子学（蛋白质印迹、RT-PCR、启动子分析、染色质免疫沉淀（ChIP）和电泳迁移率变动试验（EMSA））和代谢（蛋白质合成和降解速率）变量，评估基因失活对肥大反应的影响。这些研究的结果有望通过确定促进骨骼肌蛋白质合成和肥大的新分子靶点而具有重要的临床意义。从长远来看，操纵核糖体生物发生的能力代表了一种有前途的新策略，以减轻或改善与衰老、卧床休息和恶病质相关的肌肉萎缩。