Exploring cellular and molecular diversity between human skeletal muscles: similar but not the same

Abstract

Skeletal muscle, comprising approximately 30%-40% of the total body weight, is the largest tissue of the human body and a fundamental component of the musculoskeletal

system. Its dynamic and plastic nature makes it one of the most metabolically active organs. Although skeletal muscles share a common contractile function, they have distinct physiological, metabolic and morphological characteristics. A comprehensive understanding of these differences and their underlying causes is key to better grasp their potential role in, and contribution to muscle physiology and function. The main focus of this thesis is to explore the molecular differences that may underlie the distinct characteristics observed between skeletal muscles and to provide valuable insights into their potential functional implications. Central to this investigation is the development and integration of high-throughput methods specifically designed to identify and analyze differences between skeletal muscles. These innovative methods include bioinformatic workflows, high-throughput staining techniques, and advanced image processing and quantification. This introductory chapter provides the necessary background for the studies presented in this thesis. It also describes the methods that are used to study the molecular signatures and cellular characteristics that differentiate skeletal muscles.