Protective effect of Pulsatilla saponin A on acute myocardial infarction via miR-24-3p/p16

The effect of Pulsatilla saponin A (PsA) on acute myocardial infarction (AMI) was unknown. This study targeted to examine the roles of PsA on hypoxia-triggered toxicity to H9c2 cells and reveal the potential mechanism. H9c2 cells were maintained under a hypoxic environment for 12 h to construct the AMI cell model and the cells were pretreated by PsA. Hypoxia triggered toxicity to H9c2 cells and the anti-toxicity effect of PsA was evaluated by CCK8, TUNEL, and Western blot. The levels of miR-24-3p and p16 in H9c2 cells, AMI group tissues, and their respective controls were assessed using qRT-PCR. The dual-luciferase assay was applied to verify the targeting mechanism of miR-24-3p on p16. Then the effects of miR-24-3p inhibitor or/and si-p16 on H9c2 cells treated with PsA under hypoxia were detected by CCK8, TUNEL, and Western blot. Flow cytometry was executed to determine the cell cycle. Hypoxia decreased viability and proliferation and increased apoptosis of H9c2 cells, which were ameliorated by PsA pretreatment. The level of miR-24-3p was diminished, but p16 expression was elevated in hypoxia-treated cells and AMI group tissues. MiR-24-3p could sponge p16 in hypoxia-treated cells. Furthermore, the impact of applying miR-24-3p inhibitor on PsA and hypoxia-treated cells could be reversed by si-p16. PsA relieved hypoxia-triggered cell toxicity via miR-24-3p/p16 axis. These findings provided some fresh insights into the potential therapeutic effects of the application of PsA in AMI.