3.4 The effect of a Twist1 inhibitor on the permeability of
primary HUVEC under normal or hyperoxia conditions
A transwell chamber system with a membrane diameter of 0.4μm was used to
detect the permeability of monolayer cells; primary HUVECs are unable to
pass through an aperture of this diameter. However, FITC-dextran (40kDa)
can pass successfully through an aperture of 0.4μm and can therefore be
used as a penetrant. As shown in Figure 4D, compared with the control
group (set as 1), cell permeability in the normoxic+harmine group was
significantly increased (2.53±0.55) (p <0.01) while that of
the hyperoxia group was also significantly increased (3.06±0.30) (p
<0.001). Compared with the hyperoxia group, the cell
permeability of the hyperoxia+harmine group decreased (2.08±0.33) (p
<0.05). The results of this experiment showed that under
normal conditions, low levels of Twist1 increased the permeability of
the monolayer cells while knocking down Twist1 in hyperoxia reduced the
permeability of monolayer cells.