Figure 3.

Inhibition of miR-21 reduced the protective effect of cardiomyocyte-derived conditioned medium on cardiomyocytes against oxidative stress. (A) Western blots to determine the expression levels of apoptosis-associated proteins, including Bax, cleaved caspase 3 (c-Caspase 3), and cleaved Poly (ADP-ribose) polymerase (c-PAPR), in neonatal cardiomyocytes treated with hydrogen peroxide (50 μM of H₂O₂) and cardiomyocyte-derived conditioned medium. (B) Nuclear staining with DAPI to observe the condensed nuclei in apoptotic cells. CM, conditioned medium derived from OGD-treated cardiomyocyte. Anti-miR-21-CM, conditioned medium derived from cardiomyocyte pre-transfected with anti-miR-21 (20 nM). Groups with different symbols (*, †, ‡), p < 0.05. n = 6 for each group.