Premium
Helium Mediated Regulation of Endothelial Permeability: Involvement of Connexin 43, VE‐Cadherin and Caveolin‐1
Author(s) -
Konkel Moritz,
Smit Kirsten Fernande,
Hollmann Markus Werner,
Patel Hemal H,
Albrecht Martin,
Weber Nina Claudia
Publication year - 2017
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.31.1_supplement.1065.5
Subject(s) - connexin , caveolae , caveolin 1 , umbilical vein , chemistry , microbiology and biotechnology , endothelium , ve cadherin , western blot , biophysics , endothelial stem cell , signal transduction , biology , in vitro , gap junction , biochemistry , intracellular , endocrinology , gene
Background Caveolae are lipid enriched invaginations of the plasma membrane while Caveolins are structural proteins essential for the formation of these invaginations. Caveolins modulate signal transduction pathways in various cell types. The noble gas helium, a potent cardioprotectant, leads to decreased protein levels of Caveolin‐1 (Cav‐1) in the human endothelium and an increased level of Cav‐1 in the supernatant of human umbilical vein endothelial cells (HUVEC). Moreover, helium regulates actin filaments and decreases permeability of HUVEC monolayers. We hypothesized that (1) an upregulation of the adhesion molecules Connexin 43 and VE‐Cadherin might be involved in the decreased permeability of the endothelium after helium treatment and (2) that Cav‐1 plays a crucial role in the helium induced decrease of endothelial permeability. Methods HUVEC were isolated from fresh umbilical cords, pooled and grown upon confluent monolayers. Cells were used at passages 3–5. Cells were either exposed to 20 min of helium (5% CO 2 , 25% O 2 , 70% He) or control gas (5% CO 2 , 25% O 2 , 70% N 2 ) in a specialized gas chamber. Expression of adhesion molecules Connexin 43 and VE‐Cadherin was measured at 6, 12 and 24 hours using IR‐Western blot analyses. In order to investigate how the protective effect of helium is related to Caveolin we transfected HUVEC with small interfering RNA (siRNA) for Cav‐1 72 h before the respective experiment. Permeability was measured using Fluorescein isothiocyanate labelled bovine serum albumin (FITC‐BSA) flow‐throw after 6, 12 and 24 hours. Results In the helium group, protein analyses in cell lysate showed a significantly higher expression of Connexin 43 and VE‐Cadherin at 6 and 12 hours in comparison to the control group (for Connexin 43 in helium treated cells at 6h: 1.31±0.39 and 12h: 1.27±0.37. For Connexin 43 in control cells at 6h: 0.90±0.32 and 12h: 0.82±0.26. For VE‐Cadherin in helium treated cells at 6h: 1.19±0.28 and 12h: 1.14±0.37. For VE‐Cadherin in control cells at 6h: 0.87±0.11 and 12h: 0.85±0.14: all treatments and time points vs. control 6h and control 12h, respectively: P<0.05). Interestingly, cell permeability measurements of Cav‐1 siRNA transfected HUVEC showed no significant differences between the helium and control group suggesting a key role of Cav‐1 in endothelial permeability. Conclusion These findings suggest that an upregulation of the adhesion molecules Connexin 43 and VE‐Cadherin might be involved in the decreased permeability of the endothelium after helium treatment and that Cav‐1 plays a crucial role in the helium induced decrease of endothelial permeability. Support or Funding Information This project was in part funded by a grant fromthe IARS (International Anesthesia Research Society) and the SCA (Society of Cardiovascular Anesthesiologists) to NC Weber