Spatially-targeted optical microproteomics timecourse of rat myocardial infarction

Myocardial infarction (MI) results from occlusion of blood supply to the heart muscle causing death of cardiac muscle cells. Following myocardial infarction (MI), scar formation acts to mechanically stabilise the injured heart to prevent rupture and death. While fibroblasts and macrophages are implicated in post-MI scar formation and maturation, their exact contributions to this process are poorly characterised, especially in the long-term (i.e., beyond 1-week post-MI). Here, we employ state-of-the-art spatially-targetted optical micro-proteomics (STOMP) to isolate proteomes of tissue fractions enriched for fibroblasts (sma+) and macrophages (cd68+) over a 6-week post-MI timecourse and compare them to whole-scar proteome. We illustrate dynamic, specific changes in sma- and cd68-enriched fraction protein composition over 1-6 weeks post-MI with some of these changes reflected in whole-infarct preparations. These results link specific cell populations to specific protein changes in whole infarct.