PT  - JOURNAL ARTICLE
AU  - Rita Papp
AU  - Chandran Nagaraj
AU  - Diana Zabini
AU  - Bence M. Nagy
AU  - Miklós Lengyel
AU  - Davor Skofic Maurer
AU  - Neha Sharma
AU  - Bakytbek Egemnazarov
AU  - Gabor Kovacs
AU  - Grazyna Kwapiszewska
AU  - Leigh M. Marsh
AU  - Andelko Hrzenjak
AU  - Gerald Höfler
AU  - Miroslava Didiasova
AU  - Malgorzata Wygrecka
AU  - Laura K. Sievers
AU  - Peter Szucs
AU  - Péter Enyedi
AU  - Bahil Ghanim
AU  - Walter Klepetko
AU  - Horst Olschewski
AU  - Andrea Olschewski
TI  - Targeting TMEM16A to reverse vasoconstriction and remodelling in idiopathic pulmonary arterial hypertension
AID  - 10.1183/13993003.00965-2018
DP  - 2019 Jun 01
TA  - European Respiratory Journal
PG  - 1800965
VI  - 53
IP  - 6
4099  - http://erj.ersjournals.com/content/53/6/1800965.short
4100  - http://erj.ersjournals.com/content/53/6/1800965.full
SO  - Eur Respir J2019 Jun 01; 53
AB  - Our systematic analysis of anion channels and transporters in idiopathic pulmonary arterial hypertension (IPAH) showed marked upregulation of the Cl− channel TMEM16A gene. We hypothesised that TMEM16A overexpression might represent a novel vicious circle in the molecular pathways causing pulmonary arterial hypertension (PAH).We investigated healthy donor lungs (n=40) and recipient lungs with IPAH (n=38) for the expression of anion channel and transporter genes in small pulmonary arteries and pulmonary artery smooth muscle cells (PASMCs).In IPAH, TMEM16A was strongly upregulated and patch-clamp recordings confirmed an increased Cl− current in PASMCs (n=9–10). These cells were depolarised and could be repolarised by TMEM16A inhibitors or knock-down experiments (n=6–10). Inhibition/knock-down of TMEM16A reduced the proliferation of IPAH-PASMCs (n=6). Conversely, overexpression of TMEM16A in healthy donor PASMCs produced an IPAH-like phenotype. Chronic application of benzbromarone in two independent animal models significantly decreased right ventricular pressure and reversed remodelling of established pulmonary hypertension.Our findings suggest that increased TMEM16A expression and activity comprise an important pathologic mechanism underlying the vasoconstriction and remodelling of pulmonary arteries in PAH. Inhibition of TMEM16A represents a novel therapeutic approach to reverse remodelling in PAH.TMEM16A plays a central role in the pathological mechanisms underlying the depolarisation, vasoconstriction and proliferation of PASMCs, contributing to the increased pulmonary vascular resistance in PAH, thus providing a novel target for PAH therapy http://ow.ly/3Rs330o3CUy