Premium
Rac1 inactivation and VE‐cadherin junctional disruption contribute to alcohol‐induced endothelial hyperpermeability
Author(s) -
Doggett Travis M,
Breslin Jerome W
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.855.6
Subject(s) - ve cadherin , chemistry , umbilical vein , rac1 , ethanol , cadherin , endothelial stem cell , barrier function , microbiology and biotechnology , biophysics , biochemistry , in vitro , biology , cell , signal transduction
Alcohol intoxication can weaken endothelial barrier integrity. We tested the hypothesis that ethanol inactivates Rac1 and disrupts junctional VE‐cadherin to weaken the endothelial barrier. Transendothelial electrical resistance (TER) of human umbilical vein endothelial cell monolayers served as an index of barrier function, before and after ethanol treatment (5–100 mM). VE‐cadherin localization was determined by immunofluorescence labeling in fixed cells, or longitudinally in live cells expressing GFP‐VE‐cadherin. Rac1‐GTP levels, indicative of activity, were determined by ELISA. We also tested if the Epac1‐specific cAMP analog 8‐CPT‐2′‐O‐Me‐cAMP (8‐CPT), which activates Rac1, could ameliorate ethanol‐induced barrier dysfunction. The results show that ethanol decreases TER in a time‐ and concentration‐dependent manner, concomitant with disruption of VE‐cadherin continuity and formation of small junctional gaps. Ethanol also significantly decreases Rac1‐GTP for up to 60 min. (maximum decrease is 53 ± 5 % of control, p<0.01). Addition of 8‐CPT 5–10 min. after ethanol significantly shortens the recovery time to baseline TER. Our findings suggest that ethanol increases endothelial permeability by inactivating Rac1 and disrupting VE‐cadherin binding between endothelial cells. Supported by NIH R21AA020049, T32AA007577, R01HL098215, and the ABMRF/Foundation for Alcohol Research.