The myocardial protection effect of PCA is dependent on PKM2. Mice were orally administrated with protocatechuic aldehyde (PCA) for 3 weeks after coronary artery ligation. (A) Representative photomicrographs for HE staining of cardiac tissue sections (n = 6), Scale bar, 50 μm. (B) Representative photomicrographs for masson staining of cardiac tissue sections (n = 6). Scale bar, 50 μm. (C) 4-HNE contents in the heart (n = 6). (D) Representative M mode images of echocardiography from the assayed groups under treatments as indicated (n = 6). (E) Ejection fractions (EF) and shortening fraction (FS) in mice (n = 6). (F) Representative co-IP analysis of PKM2 and β-catenin in the heart (n = 3). The mRNA levels of Myc (G), Ccnd1 (H) and Sgk1 (I) in the heart (n = 6). (J) Immunocytochemical staining of BAX, BCL-2 and c-caspase 3 protein expression (n = 6), scale bar = 50 μm. (K) Representative TUNEL staining images and quantification of TUNEL positive cells (n = 6). Results are shown as mean ± SD; ∗P < 0.05, ∗∗P < 0.01, ∗∗∗P < 0.001.