Figure 8
A population of PDGFRα+ fibroblasts, expressing the macrophage markers Mac2, Mac3, and Lysozyme-M emerges during the proliferative phase of infarct healing. PDGFRα-EGFP fibroblast reporter mice underwent non-reperfused myocardial infarction protocols. Dual immunofluorescence for GFP and macrophage antibodies (Mac2, Mac3, Lysozyme antibody clone EPR2994(2)) was performed in control hearts and in infarcted myocardial segments from mice undergoing 3-day, 7-day and 28-day coronary occlusion protocols. Control hearts and early infarcted hearts showed negligible numbers of PDGFRα+ fibroblast cells that express macrophage markers (arrows). At the peak of the proliferative phase (7d after coronary occlusion), a significant population of PDGFRα+ fibroblasts were Mac2 positive (A,D), Mac3 positive (B,E), or LyzM positive (C,F).In comparison to Mac2 and Mac3, LyzM labeled a lower number of PDGFR\(\mathrm{\alpha }\)+ cells (**p < 0.01, ****p < 0.0001 vs. control, n = 4–5/group). Scale bar: 20 μm.
