Single Skeletal Muscle Fiber Mechanics and Myosin Kinetics in Human Aging

该项目描述了一个培训计划和研究项目，为候选人提供必要的技能和基于实验室的技术，以进行临床研究，并过渡到一个独立的研究人员。候选人：候选人的长期目标是发展自己的研究计划，重点是人类骨骼肌的结构和功能变化，导致老化，废用和疾病。候选人是佛蒙特大学的研究助理，具有工程学背景。他首次将正弦分析的新技术应用于单个人类骨骼肌纤维，从而首次研究了人类收缩功能的分子决定因素。环境：佛蒙特大学非常适合候选人提出的研究和培训。它包括一个由临床医生和基础科学研究人员组成的有凝聚力的团队，他们从事临床研究和肌肉生理学，检查整个身体，整个肌肉，单纤维和单分子水平的功能。调研：拟议研究的目的是表征单个人类骨骼肌纤维功能中年龄相关变化的分子机制。我们假设衰老通过以下方式损害单纤维功能：1）改变肌球蛋白动力学（增加肌球蛋白附着时间和降低肌球蛋白力产生率）和2）降低肌球蛋白重链含量。为了检验这些假设，将从年轻（21-35岁）和老年（65-75岁）志愿者获得来自单个骨骼肌纤维的收缩性能和肌原纤维蛋白表达。这项研究将代表人类骨骼肌收缩功能障碍的分子水平上的机制的第一次全面检查。相关性：在肌球蛋白-肌动蛋白交叉桥水平上理解年龄相关的骨骼肌收缩功能障碍是开发更有效的药理学和生活方式对策以纠正专门针对分子缺陷的肌肉减少症的必要步骤。

DESCRIPTION (provided by applicant): Project Summary This application for a Mentored Research Scientist Development Award (K01) describes a training program and research project that provides the candidate with the necessary skills and laboratory-based techniques to conduct clinical research studies and to make the transition to an independent researcher. Candidate: The candidate's long term goal is to develop his own research program focusing on the structural and functional alterations in human skeletal muscle that result from aging, disuse and disease. The candidate is a Research Associate at the University of Vermont with a background in engineering. He has, for the first time, applied the novel technique of sinusoidal analysis to single human skeletal muscle fibers; thereby allowing the first examinations of the molecular determinants of contractile function in humans. Environment: The University of Vermont is ideally suited to the candidate's proposed research and training. It includes a cohesive group of clinicians and basic science researchers engaged in clinical research and muscle physiology that examines function at the whole body, whole muscle, single fiber and single molecule levels. Research: The objective of the proposed research study is to characterize the molecular mechanisms underlying age-related changes in single human skeletal muscle fiber function. We hypothesize that aging impairs single fiber function by: 1) altering myosin kinetics (increasing myosin attachment time and decreasing myosin rate of force production) and 2) decreasing myosin heavy chain content. To test these hypotheses, contractile performance and myofibrillar protein expression from single skeletal muscle fibers will be obtained from young (21-35 yrs old) and elderly (65-75 yrs old) volunteers. The proposed studies will represent the first comprehensive examination of the mechanisms underlying human skeletal muscle contractile dysfunction with aging at the molecular level. Relevance: Understanding age-related skeletal muscle contractile dysfunction at the level of the myosin- actin cross-bridge is a necessary step towards developing more effective pharmacological and lifestyle countermeasures to correct sarcopenia that are directed specifically at molecular defects.