Hyaluronan provokes inflammation but suppresses phagocytotic function in macrophages.

Background: The extracellular matrix (ECM) provides structural and functional support for the myocardium, but myocardial infarction (MI) changes the composition of the ECM. One of the chief components of the ECM, hyaluronan (HA), accumulates after MI; however, specific biological actions of HA-particularly at the level of infiltrating immune cells and implications of such interactions on ventricular remodeling-have not been explored.

Goal: Because acute accumulation of HA coincides with macrophage infiltration after MI, we assessed the impact of HA on macrophage function.