The extracellular matrix: at the center of it all

Abstract

The extracellular matrix is not only a scaffold that provides support for cells, but it is also involved in cell-cell interactions, proliferation and migration. The intricate relationships among the cellular and acellular components of the heart drive proper heart development, homeostasis and recovery following pathological injury. Cardiac myocytes, fibroblasts and endothelial cells differentially express and respond to particular extracellular matrix factors that contribute to cell communication and overall cardiac function. In addition, turnover and synthesis of ECM components play an important role in cardiac function. Therefore, a better understanding of these factors and their regulation would lend insight into cardiac development and pathology, and would open doors to novel targeted pharmacologic therapies. This review highlights the importance of contributions of particular cardiac cell populations and extracellular matrix factors that are critical to the development and regulation of heart function.

Figure 1

Schematic of cellular changes (grey boxes) and ECM factor expression (black boxes) during various physiological cardiac states (white boxes).

Figure 2

Representative diagram of the cellular milieu within the myocardium. Note both individual and overlapping contributions of prominent matrix components by each cell type.

Figure 3

The process of blood vessel formation. To initiate new capillary formation, endothelial cells of existing vessels must degrade the underlying basement membrane and invade into the neighboring tissue. These processes require the activities of urokinase-plasminogen activator (uPA) and matrix metalloproteinases (MMPs).