Calcium Leak-Dependent Muscle Function Loss in Aged C elegans

老年秀丽隐杆线虫钙泄漏依赖性肌肉功能丧失

基本信息

批准号：
9151626
负责人：
Frances Margaret Forrester
金额：
$ 4.4万
依托单位：
COLUMBIA UNIVERSITY HEALTH SCIENCES
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-01-01 至 2017-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9151626
关键词：
Actins Age Aging American Binding Caenorhabditis elegans Caffeine Calcium Cell physiology Censuses Chronic Coupled Coupling Custom Dissection Dissociation Drug Targeting Dyes Elderly Electron Transport Endoplasmic Reticulum Free Radicals Functional disorder Future Genetic Models Goals Health Homologous Gene Human Image Immunoprecipitation Ions Lead Life Locomotion Longevity Measures Mediating Membrane Proteins Mitochondria Modeling Morbidity - disease rate Mus Muscle Muscle Contraction Muscle Proteins Muscle Weakness Muscle function Muscular Atrophy Myosin ATPase Nematoda Oxides Pathogenicity Pathologic Pharmacology Play Population Post-Translational Protein Processing Prevalence Probability Production Protein Biochemistry Reactive Oxygen Species Research Research Personnel Role Ryanodine Receptor Calcium Release Channel Ryanodine Receptors Sarcoplasmic Reticulum Source Swimming Techniques Testing Time Training Tropomyosin Troponin C age related age-related muscle loss age-related muscle weakness aged bone career cell motility defined contribution experimental study fall risk genetic approach genetic regulatory protein improved loss of function mitochondrial membrane muscle aging muscle form muscle physiology mutant novel therapeutics oxidation public health relevance sarcopenia therapeutic target

项目摘要

DESCRIPTION (provided by applicant): Sarcopenia, defined as an age-related loss of muscle mass and function, is a burgeoning health problem with a prevalence as high as 30% in the geriatric population. Current treatments have low long- term efficacy and do not target any underlying causes of muscle function loss. Recent research in aged mice in our lab has implicated the Ryanodine Receptor (RyR1), an intracellular calcium release channel important for excitation-contraction coupling, as a potential therapeutic target. Over time, RyR1 undergoes posttranslational modification ('remodeling') that causes calstabin1, an important RyR1 modulatory subunit, to dissociate from the channel; this results in increased RyR1 open probability and Ca2+ 'leak'. This Ca2+ 'leak' cause nearby mitochondria to overload with calcium and produce excess reactive oxygen species (ROS), which exacerbate the leak by further remodeling RyR1. Due to the relatively long lifespan of mice we were testing if C. elegans could serve as a better model of age- dependent muscle function loss. C. elegans contain UNC-68, the RyR1 homologue, and FKB-2, a calstabin homologue; therefore, we hypothesize that 1) FKB-2 dissociation destabilizes UNC-68 channels, resulting in pathogenic sarcoplasmic reticulum (SR) calcium leak and subsequent muscle weakness in aged nematodes and 2) mitochondrial ROS oxidizes nearby UNC-68 channels and exacerbates SR calcium leak in body wall muscle. Aim One will test whether leaky UNC-68 channels play a role in C. elegans muscle weakness. We first established that UNC-68 remodeling increases with age in WT worms, but is accelerated in FKB-2 KO worms using immunoprecipitation and immunoblot. We have determined that FKB-2 depletion results in reduced peak Ca2+ transients and blunted UNC-68 caffeine activation by crossing WT and FKB-2 KO worms with Pmyo-3: GCaMP2 worms. In Aim Two, we will assess the contribution of mitochondrial ROS in UNC-68 dysfunction by measuring mitochondrial free radicals in two electron transport chain (ETC) mutant strains, clk-1 and mev-1. We have found that the timing of UNC-68 remodeling correlates with their lifespan differences; clk-1 is long-lived and lacks UNC- 68 remodeling until old age, while mev-1 is short-lived and has remodeled UNC-68 channels earlier in life. Successful completion of the proposed studies will define the contributions of pathological SR calcium leak in age-dependent muscle function loss.

描述（由适用提供）：肌肉减少症，被定义为与年龄相关的肌肉质量和功能丧失，是一个残酷的健康问题，在老年人群中的患病率高达30％。当前治疗的长期效率较低，并且不针对任何肌肉功能丧失的根本原因。我们实验室中对老年小鼠的最新研究已经实施了Ryanodine受体（RYR1），Ryanodine受体（RYR1）是一种潜在的治疗靶标，是一种对兴奋偶联的细胞内钙释放通道。随着时间的流逝，RYR1经历了导致Calstabin1（一个重要的RYR1调节亚基）与通道解离的Calstabin1的翻译后修饰（“重塑”）。这会增加RYR1开放概率和Ca2+'泄漏'。这种Ca2+“泄漏”导致线粒体附近导致与钙过载并产生过量的活性氧（ROS），从而通过进一步的重塑RyR1加剧了泄漏。由于小鼠的相对长寿命，我们正在测试秀丽隐杆线虫是否可以作为年龄依赖性肌肉功能丧失的更好模型。秀丽隐杆线虫含有UNC-68，RYR1同源物和Calstabin同源物FKB-2； therefore, we hypothesize that 1) FKB-2 dissociation destabilizes UNC-68 channels, resulting in pathogenic sarcoplasmic reticulum (SR) calcium leak and subsequent muscle weakness in aged nematodes and 2) mitochondrial ROS oxides near by UNC-68 channels and exacerbates SR calcium leak in body wall muscle. AIM ONE将测试泄漏的UNC-68通道是否在秀丽隐杆线虫肌肉无力中起作用。我们首先确定UNC-68重塑随着WT蠕虫的年龄增长而增加，但使用免疫沉淀和免疫印迹在FKB-2 KO蠕虫中加速了。我们已经确定FKB-2部署通过将WT和FKB-2 KO Worms与PMYO-3：GCAMP2 Worms越过WT和FKB-2 KO Worms，导致峰值Ca2+瞬变降低和蓝色的UNC-68咖啡因激活。在目标二中，我们将通过测量两个电子传输链（ETC）突变株，CLK-1和MEV-1中的线粒体自由基来评估线粒体ROS在UNC-68功能障碍中的贡献。我们发现，UNC-68重塑的时机与他们的Livespan差异相关。 CLK-1长期存在，缺乏UNC-68重塑直到老年，而MEV-1则是短暂的，并且已经改建了UNC-68频道。拟议研究的成功完成将定义病理SR钙泄漏在年龄依赖性肌肉功能损失中的贡献。