Referenced in: none

Automatically associated channels: TRP , TRPC , TRPC6

Title: Activation of TRPC6 channels is essential for lung ischaemia-reperfusion induced oedema in mice.

Authors: Norbert Weissmann, Akylbek Sydykov, Hermann Kalwa, Ursula Storch, Beate Fuchs, Michael Mederos Y Schnitzler, Ralf P Brandes, Friedrich Grimminger, Marcel Meissner, Marc Freichel, Stefan Offermanns, Florian Veit, Oleg Pak, Karl-Heinz Krause, Ralph T Schermuly, Alison C Brewer, Harald H H W Schmidt, Werner Seeger, Ajay M Shah, Thomas Gudermann, Hossein A Ghofrani, Alexander Dietrich

Journal, date & volume: Nat Commun, 2012 , 3, 649

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/22337127

Abstract
Lung ischaemia-reperfusion-induced oedema (LIRE) is a life-threatening condition that causes pulmonary oedema induced by endothelial dysfunction. Here we show that lungs from mice lacking nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (Nox2(y/-)) or the classical transient receptor potential channel 6 (TRPC6(-/-)) are protected from LIR-induced oedema (LIRE). Generation of chimeric mice by bone marrow cell transplantation and endothelial-specific Nox2 deletion showed that endothelial Nox2, but not leukocytic Nox2 or TRPC6, are responsible for LIRE. Lung endothelial cells from Nox2- or TRPC6-deficient mice showed attenuated ischaemia-induced Ca(2+) influx, cellular shape changes and impaired barrier function. Production of reactive oxygen species was completely abolished in Nox2(y/-) cells. A novel mechanistic model comprising endothelial Nox2-derived production of superoxide, activation of phospholipase C-γ, inhibition of diacylglycerol (DAG) kinase, DAG-mediated activation of TRPC6 and ensuing LIRE is supported by pharmacological and molecular evidence. This mechanism highlights novel pharmacological targets for the treatment of LIRE.