The Extracellular Matrix Complexome from Skeletal Muscle

Abstract

The various layers of the extracellular matrix, forming the endomysium, perimysium and epimysium of skeletal muscles, provide essential structural and mechanical support to contractile fibres. Crucial aspects of muscle elasticity and fibre contractility are dependent on proper cell-matrix interactions. A complex network of collagen fibres, nonfibrillar collagens, proteoglycans, matricellular proteins, matrix metalloproteinases, adhesion receptors and signalling molecules maintain the physical structure for force transmission within motor units, embed critical cellular structures such as capillaries and motor neurons, and enable essential sarcolemma-matrix adhesion processes and signalling cascades. The systems biological concept of protein complexomes, which assumes the existence of interconnectivities between large protein assemblies, can be readily applied to the proteins within the extracellular space of muscles. Recent proteomic studies confirm that the extracellular matrix complexome has considerable influence on the integrity and cellular functions of skeletal muscle fibres. Adaptations or changes in the organization of the extracellular matrix play a crucial role during fibre regeneration following injury, extensive neuromuscular activity or pathophysiological insults. This chapter outlines the molecular components of the matrisome from skeletal muscles and discusses the extracellular matrix in relation to myogenesis, maturation of motor units, adaptation to changed functional demands and myofibrosis in muscular disorders.

Age‐specific response of skeletal muscle extracellular matrix to acute resistance exercise: A pilot study

“…The collagen superfamily with its 28 different isoforms represents the main structural component of the ECM (Ricard‐Blum, 2011), whereby in mature muscles collagens are found in the interstitial matrix (COL I, COL III, COL V, XI, XII, XIV, XV, XVIII), in ECM microfibrils (COL VI) and the basal lamina (COL IV, VI, XV, XVIII) (Murphy & Ohlendieck, 2016). The PCR array used in this study comprised 12 different collagen genes, capturing most of the above‐mentioned muscular isoforms with the exception of COL III and XVIII.…”

Skeletal muscle: A review of molecular structure and function, in health and disease

“…A variety of regulatory ECM proteins are involved in matrix assembly and the modulation of cell-matrix interactions, including nidogens, periostin, and SPP1. MMPs and their inhibitors (TIMP1, TIMP2) are an important class of ECMassociated enzymes that maintain ECM integrity and regulate ECM protein degradation (Arpino, Brock, & Gill, 2015; F I G U R E 1 0 A schematic representation of the main extracellular matrix proteins and their approximate localization surrounding skeletal muscle S. Murphy & Ohlendieck, 2016). A variety of PGs (such as hyaluronan), chondroitin sulfate/dermatan sulfate PGs (such as versican; Nandadasa, Foulcer, & Apte, 2014), small leucine-rich repeat PGs (e.g., biglycan, decorin, lumican, fibromodulin) and HS PGs (e.g., syndecan, perlecan, agrin) have been identified to be distributed between the collagen fibers (Halper & Kjaer, 2014).…”

Recent Advances on Stimuli-Responsive Hydrogels Based on Tissue-Derived ECMs and Their Components: Towards Improving Functionality for Tissue Engineering and Controlled Drug Delivery

“…In addition to anisotropic cellular alignment, mature muscular phenotypes have specific ECM patterns around myotubular structures to allow adequate muscle contraction. Collagen IV fibers, which attach directly to sarcolemmas and connect them to other types of collagen [ 96 ], exhibit a lower degree of alignment/stiffness in parallel locations to myotubes to minimally interfere with myotube contraction. In contrast, fibers located in series with myotubes have a higher degree of alignment to bear and transmit the contraction forces to the imposed load (see Figure 3 B) [ 97 ].…”