Figure 6.

Macrophage GR as a crucial regulator of myofibroblast differentiation in the infarct microenvironment. A, B) FACS strategy to obtain highly purified fibroblasts and myofibroblasts from GR^flox (A) and GR^LysMCre (B) ischemic myocardium 3 d after coronary artery ligation. Endothelial, hematopoietic, and vascular cells were excluded by selecting cells that are CD31⁻/TER-119⁻, CD45⁻/CD11b⁻, and NG2⁻/PDGFRβ⁻. Immunocytochemical staining of sorted MEFSK4⁺ cells showing vimentin (Vim) and α-SMA. Scale bars = 50 µm. C) RT-PCR was used to detect the relative gene expression of α-SMA (Acta2), MMP-2, periostin (Postn), collagen I α1 (Col1a1), platelet-derived growth factor receptor α (Pdgfra), and discoidin domain-containing receptor 2 (Ddr2). D) Zymography and reverse zymography of conditioned medium from cardiac fibroblasts isolated from GR^flox/GR^LysMCre infarcts. Means ± sem (n = 3–4). *P < 0.05 vs. GR^flox.