The expression of miR-210 in H9C2 was upregulated in hypoxic H9C2 cells.
To generate an optimized model of anoxic myocardial cells, H9C2 cells were treated with CoCl2 for 24, 48 and 72 h. The number of apoptotic cells and relative miR-210 expression are shown in Figure 1. With increasing CoCl2 concentrations and treatment duration, the apoptosis ratio of H9C2 cells was enhanced (Figure 1A). Additionally, the relative expression of miR-210 increased in a time-dependent manner (Figure 1B). We found that a 24 h and 48 h hypoxia treatment provoked similar apoptosis ratios in H9C2 cells. Therefore, a 48 h hypoxia duration was used in H9C2 cardiomyocytes for all subsequent experiments.