PT Unknown AU Konkel, M TI Helium-mediated regulation of endothelial permeability: involvement of Caveolin-1, VE-Cadherin and Connexin-43 PY 2019 PU Christian-Albrechts-Universität zu Kiel WP https://macau.uni-kiel.de/receive/diss_mods_00025717 LA en DE helium; endothelial permeability; Caveolin-1; VE-Cadherin; Connexin-43; HUVEC; siRNA; endotheliale Permeabilität AB Background: Recent studies suggested that helium is able to protect the heart against ischemia/reperfusion injury. We have recently shown that helium attenuates permeability of monolayers of HUVEC and that helium leads to decreased intra-cellular protein levels of caveolin-1 (Cav-1). Nevertheless, the underlying cellular and molecular mechanisms and the precise role of Cav-1 in helium-mediated regulation of endothelial barrier integrity are still unclear. We therefore investigated whether Cav-1 is involved in helium-mediated stabilization of the endothelial barrier and whether the expression of the key junctional molecules vascular endothelial-cadherin (VE-cadherin) and connexin-43 (Cx43) is regulated by helium and might be involved in the effects of helium on the endothelial barrier function. Methods: HUVEC were either exposed to 20 min of helium or control gas. Permeability was measured using confluent monolayers of HUVEC on microporous membranes and FITC-BSA flow through. To investigate if the effects of helium on the endothelial barrier function are related to Cav-1, HUVEC were transfected with Cav-1 siRNA prior to helium application. Expression of VE-cadherin and Cx43 was analyzed by western blotting. Results: While helium attenuated permeability of HUVEC monolayers in non-transfected HUVEC, effects of helium on cell permeability were abrogated in Cav-1 siRNA transfected HUVEC, suggesting a key role of Cav-1 in endothelial permeability. In the helium group, protein analyses in cell lysates showed a significantly higher expression of VE-cadherin and Cx43 at 6 and 12 hours. Transfecting HUVEC with Cav-1 siRNA abolished the effect of helium on VE-cadherin and Cx43 expression, pointing towards a role of Cav-1 in the helium-induced alteration of junctional molecule expression. Conclusion: Our findings suggest that Cav-1 is involved in the helium-mediated attenuation of HUVEC permeability and in the helium-mediated increase in the expression of VE-cadherin and Cx43. PI Kiel ER