3.3 Changes in the protein expression of Twist1 and Tie2 in primary HUVECs under normal or hyperoxia conditions after using a Twist1 inhibitor
In the first step of this experiment, we used a final concentration of 3μmol/L of harmine, as determined by CCK8 data. Statistical analysis showed that this concentration had no significant effect on the viability of cells, but it was uncertain whether this concentration of harmine could inhibit the expression of Twist1 protein and further inhibit the expression of the Tie2 protein downstream. Therefore, western blot was used to detect the changes in protein expression of Twist1 and Tie2 after the use of harmine. As shown in Figure 3, compared with the control group, the expression of Twist1 protein in the normoxia + harmine group was significantly reduced (p < 0.05) (Figure 3A, 3B). Compared with the hyperoxia group, the expression of Twist1 protein in the hyperoxia + harmine group also decreased significantly (p < 0.05) (Figure 3A, 3B). Twist1 is the regulator of Tie2, and the trend for change with the Tie2 protein was consistent with that of Twist1. Under both normal and hyperoxia conditions, the expression of Tie2 decreased significantly after the addition of harmine (p < 0.01, p < 0.05, respectively) (Figure 3A, 3C). These results proved that 3μmol/L of harmine inhibited the expression of Twist1 and Tie2 proteins, thus achieving an efficient interventional effect.