Anoctamin‐1 is expressed and functional in the Pulmonary Vascular Endothelium

Abstract

Background and ObjectiveThe expression and functional role of Anoctamin‐1 (ANO1), a Ca2+ activated Cl channel in the endothelial cells (EC) is unclear. We sought to confirm the presence of ANO1 in the pulmonary vascular EC (PVEC) and the effect of ANO1 activation on EC membrane potential (Vm).MethodsWhole lung lysates and primary isolated rat lung EC (RLEC) were isolated from 8 week old Sprague‐Dawley rats. ANO1 expression was evaluated in whole lung, commercially available primary rat lung microvascular EC (RLMVEC) and human pulmonary artery EC (HPAEC) lysates by immunoblot, in RLEC and RLMVEC by RT‐PCR, and in RLEC by immunofluorescence (IF). Changes in RLMVEC Vm was assessed using DiBAC4(3) and fluorescent live cell imaging.ResultsImmunoblotting confirmed the presence of ANO1 in whole lung lysates, RLMVEC, and HPAEC. RT‐PCR validated ANO1 expression in RLMVEC and RLEC. IF confirmed the expression of ANO1 on RLEC. Activation of ANO1 with 10μM Eact, a ANO1 opener, resulted in a hyperpolarization of Vm, which was attenuated in presence of a low chloride solution.ConclusionANO1 is expressed in the PVEC and can alter the resting Vm.