The extracellular matrix: An overview

The extracellular matrix encompasses the very large number of constituent macromolecules that are synthesized and secreted by cells into the space surrounding them, followed in most cases by further assembly, cross-linking, and/or polymerization of the secreted proteins to form an organized structure. The extracellular matrix has a number of critical roles in tissue and organ development, function, and repair after injury. In addition, there are numerous serious and debilitating genetic diseases whose bases lie in mutations in genes encoding extracellular matrix proteins. There are also acquired diseases, such as scurvy, chronic obstructive pulmonary disease, and cancer, that can be caused by damage to or are influenced by changes in the organization or integrity of the extracellular matrix. The goal of this chapter is to provide an overview of the extracellular matrix by discussing the different classes of extracellular matrix molecules and presenting a subset of individual extracellular matrix proteins from each class in greater detail in order to demonstrate their importance.