Fig. 4

HFpEF mouse hearts showed abnormal activation of ferroptosis. A Relative expression of Ptgs2 mRNA in myocardial tissues using RT-qPCR. Gapdh was used as an internal reference, n = 5 mice per group. B Representative Prussian blue-stained images of cross-sections of two groups of mouse hearts, and black arrows show blue-stained cardiomyocytes; Percentage of Prussian blue-stained positive cells, n = 5 mice per group. C Measurement of total iron ion content in myocardial tissue, n = 5 mice per group. D SOD activity level in myocardial tissue, n = 5 mice per group. E Representative DHE staining images of heart tissue, n = 5 mice per group. F Representative transmission electron microscopy images of heart tissue, n = 5 mice per group. G, H MDA levels in plasma and heart tissue, n = 5 mice per group. I Representative western blot images and average protein levels of SLC7A11, GPX4, NRF2 and ATF4 in control and HFpEF mouse hearts, n = 5 mice per group. Statistical significance was calculated by Student’s t test; *P < 0.05, **P < 0.01, and ***P < 0.001