Proteomic analysis of the left ventricle post-myocardial infarction to identify in vivo candidate matrix metalloproteinase substrates.

Left ventricular remodeling post-myocardial infarction (MI) involves a multitude of mechanisms that regulate the repair response. Matrix metalloproteinases (MMPs) are a major family of proteolytic enzymes that coordinate extracellular matrix turnover. Both MMP-7 deletion and MMP-9 deletion reduce of the left ventricle post-MI, but the mechanisms have not been fully clarified. Both MMP-7 and MMP-9 have a large number of known in vitro substrates, but in vivo substrates for these two MMPs in the myocardial infarction setting are incompletely identified. Advances in proteomic techniques have enabled comprehensive profiling of protein expression in cells and tissue. In this chapter, we describe a protocol for the proteomic analysis of in vivo candidate MMP substrates in the post-MI left ventricle using two-dimensional electrophoresis, liquid chromatography coupled with tandem mass spectrometry, and immunoblotting.