Fig. 4

Sustained miR-133 expression is associated with scar formation. A–F) Wildtype, Tg(miR-133a1)^pd47 and Tg(miR-133sp)^pd48 adult hearts were resected and subjected to daily heat-treatment at 38 °C for 30 days. A–C) Representative 30 dpa wildtype, Tg(miR-133a1)^pd47 and Tg(miR-133sp)^pd48 heart sections were stained with Mef2 (green) and PCNA (red). Insets in (A–C), high zoom images of the white dashed rectangle; arrowheads indicate proliferating CMs. D–F) Alternatively, representative 30 dpa wildtype control, Tg(miR-133a1)^pd47 and Tg(miR-133sp)^pd48 adult heart sections stained to detect Collagen with an AFOG assay. G) CM proliferation indices were determined for each group at 7 dpa. n = 8–12; Mean ± SEM, Student′s t-test p-value < 0.001 for * and **. HS = heat-shock. Scale bar in (A–F) represents 100 μm. White brackets represent approximate amputation planes. HS = heat-shock. AFOG = acid fuchsin orange G.