3.5 The effect of Twist1 inhibitor on the distribution and
expression of VE-cadherin in primary HUVECs under normal or hyperoxia
conditions
There are three types of connections between endothelial cells: adhesive
connections, tight connections and gap connections; however, adhesive
connection are the most important structure with which to control
vascular permeability24. Adhesive connections are
mainly composed of vascular endothelial cadherin (VE-cadherin) complex
and serve to maintain the barrier function and permeability of vascular
endothelial cells25,26. Therefore, after reducing the
expression of Twist1, the expression and distribution of VE-cadherin
protein in HUVECs was detected by immunofluorescence cytochemistry.
Laser confocal immunofluorescence (Figure 4A) showed that VE-cadherin
was mainly expressed in the cell membranes of HUVECs, although a small
amount was detected in the cytoplasm. The expression of this protein
increased significantly at the adhesion junction between cells. As shown
in Figure 4A, 4B, and 4C, there was high levels of VE-cadherin
expression on the cell membranes of HUVECs in the control group.
Furthermore, the staining of cell boundaries was clear, the
intercellular connections were close, and the immunofluorescence
intensity was( 9.21±2.11 A.U.). Compared with the control group, the
expression of VE-cadherin in the cell membranes of HUVECs in the
normoxic+harmine group and hyperoxia group was decreased, the cell
boundary showed a discontinuous distribution, there was a weak
connection between cells, and the immunofluorescence intensities
respectively were (2.54±0.31 A.U.) and (2.19±0.46 A.U.). In contrast,
compared with the hyperoxia group, the expression of VE-cadherin in the
cell membranes of HUVECS in the hyperoxia+ harmine group
was increased and red fluorescence was distributed continuously along
the cell membrane, the cell boundary was clear and tightly connected,
and the immunofluorescence intensity was (8.51±1.46 A.U.).