Figure 2.

MAGI1 is required to maintain EC barrier function. (A) WES analysis of MAGI1 protein expression level in lysates collected from HUVECs transduced with Ad-MAGI1 or Ad-LacZ, β-actin served as a loading control. Protein bands are shown as pseudoblots. (B) Thb (10 U/mL)-mediated reduction in TEER values observed in cells transduced with Ad-LacZ (red) was inhibited in cells transduced with Ad-MAGI1 (blue), as assessed by ECIS system and shown as normalized resistance measured approximately every 4 min for indicated times. The dashed line indicates addition of Thb. (C) Graph demonstrates normalized resistance after Thb treatment at indicated times, relative to basal level (mean ± SEM, n = 3). (D) IB analysis of MAGI1 protein expression level in lysates collected from human aortic ECs (HAECs) treated with MAGI1 siRNA (siMAGI1) (100 nM, 48 h) or control siRNA (siCTRL), tubulin served as a loading control. (E) Thb (5 U/mL)-mediated reduction in TEER values observed in cells treated with siCTRL (blue) was increased to a greater extent in cells treated with siMAGI1 (red), as assessed by the ECIS system and shown as normalized resistance measured approximately every 4 min for indicated times. The dashed line indicates addition of Thb. A reduction in TEER values indicates an increase in cell barrier permeability (33) through paracellular mechanisms (34). (F) Graph demonstrates normalized resistance after Thb treatment at indicated times, relative to basal level (mean ± SEM, n = 4). Statistical significance was assessed using ANOVA followed by Bonferroni post-hoc testing for multiple group comparison. ***P < 0.001 and *P < 0.05.