Referenced in: none

Automatically associated channels: K2P , TASK1

Title: Potassium Channel Subfamily K Member 3 (KCNK3) Contributes to the Development of Pulmonary Arterial Hypertension.

Authors: Fabrice Antigny, Aurélie Hautefort, Jolyane Meloche, Milia Belacel-Ouari, Boris Manoury, Catherine Rücker-Martin, Christine Péchoux, François Potus, Valérie Nadeau, Eve Tremblay, Grégoire Ruffenach, Alice Bourgeois, Peter Dorfmüller, Sandra Breuils-Bonnet, Elie Fadel, Benoît Ranchoux, Philippe Jourdon, Barbara Girerd, David Montani, Steeve Provencher, Sébastien Bonnet, Gérald Simonneau, Marc Humbert, Frédéric Perros

Journal, date & volume: Circulation, 2016 Apr 5 , 133, 1371-85

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/26912814

Abstract
Mutations in the KCNK3 gene have been identified in some patients suffering from heritable pulmonary arterial hypertension (PAH). KCNK3 encodes an outward rectifier K(+) channel, and each identified mutation leads to a loss of function. However, the pathophysiological role of potassium channel subfamily K member 3 (KCNK3) in PAH is unclear. We hypothesized that loss of function of KCNK3 is a hallmark of idiopathic and heritable PAH and contributes to dysfunction of pulmonary artery smooth muscle cells and pulmonary artery endothelial cells, leading to pulmonary artery remodeling: consequently, restoring KCNK3 function could alleviate experimental pulmonary hypertension (PH).We demonstrated that KCNK3 expression and function were reduced in human PAH and in monocrotaline-induced PH in rats. Using a patch-clamp technique in freshly isolated (not cultured) pulmonary artery smooth muscle cells and pulmonary artery endothelial cells, we found that KCNK3 current decreased progressively during the development of monocrotaline-induced PH and correlated with plasma-membrane depolarization. We demonstrated that KCNK3 modulated pulmonary arterial tone. Long-term inhibition of KCNK3 in rats induced distal neomuscularization and early hemodynamic signs of PH, which were related to exaggerated proliferation of pulmonary artery endothelial cells, pulmonary artery smooth muscle cell, adventitial fibroblasts, and pulmonary and systemic inflammation. Lastly, in vivo pharmacological activation of KCNK3 significantly reversed monocrotaline-induced PH in rats.In PAH and experimental PH, KCNK3 expression and activity are strongly reduced in pulmonary artery smooth muscle cells and endothelial cells. KCNK3 inhibition promoted increased proliferation, vasoconstriction, and inflammation. In vivo pharmacological activation of KCNK3 alleviated monocrotaline-induced PH, thus demonstrating that loss of KCNK3 is a key event in PAH pathogenesis and thus could be therapeutically targeted.