MMPs 2 and 9 are essential for coronary collateral growth and are prominently regulated by p38 MAPK

► p38 MAPK is required for MMP 2/9 activity during coronary collateral growth (CG). ► MMP 2/9 activity is essential for extracellular matrix (ECM) degradation and CG. ► Lack of CG in metabolic syndrome correlates with lack of MMP 2/9 activity and reduced ECM degradation.