Cardiac Hyaluronan Synthesis Is Critically Involved in the Cardiac Macrophage Response and Promotes Healing After Ischemia Reperfusion Injury.

Rationale: Immediate changes in the ECM (extracellular matrix) microenvironment occur after myocardial ischemia and reperfusion (I/R) injury.

Objective: Aim of this study was to unravel the role of the early hyaluronan (HA)-rich ECM after I/R.

Methods And Results: Genetic deletion of Has2 and Has1 was used in a murine model of cardiac I/R.

CDKN1B/p27 is localized in mitochondria and improves respiration-dependent processes in the cardiovascular system-New mode of action for caffeine.

We show that the cyclin-dependent kinase inhibitor 1B (CDKN1B)/p27, previously known as a cell cycle inhibitor, is also localized within mitochondria. The migratory capacity of endothelial cells, which need intact mitochondria, is completely dependent on mitochondrial p27. Mitochondrial p27 improves mitochondrial membrane potential, increases adenosine triphosphate (ATP) content, and is required for the promigratory effect of caffeine.