Physiological Reports ISSN 2051-817X ORIGINAL RESEARCH Altered physiological functions and ion currents in atrial fibroblasts from patients with chronic atrial fibrillation Claire Poulet1, Stephan Kunzel€ 1, Edgar Buttner€ 1, Diana Lindner2, Dirk Westermann2 & Ursula Ravens1 1 Department of Pharmacology and Toxicology, Medical Faculty Carl-Gustav-Carus, TU Dresden, Dresden, Germany 2 Department of General and Interventional Cardiology, University Heart Center Hamburg Eppendorf, Hamburg, Germany Keywords Abstract Atrial fibrillation, electrophysiology, fibroblasts. The contribution of human atrial fibroblasts to cardiac physiology and patho- physiology is poorly understood. Fibroblasts may contribute to arrhythmogen- Correspondence esis through fibrosis, or by directly altering electrical activity in Claire Poulet, Imperial College London, Imperial cardiomyocytes. The objective of our study was to uncover phenotypic differ- Centre for Translational and Experimental ences between cells from patients in sinus rhythm (SR) and chronic atrial fib- Medicine, Hammersmith Campus, Du Cane rillation (AF), with special emphasis on electrophysiological properties. We Road, London W12 0NN, UK isolated fibroblasts from human right atrial tissue for patch-clamp experi- Tel: +44 207 594 2738 Fax: +44 207 594 3653 ments, proliferation, migration, and differentiation assays, and gene expression E-mail:
[email protected] profiling. In culture, proliferation and migration of AF fibroblasts were strongly impaired but differentiation into myofibroblasts was increased. This Present Addresses was associated with a higher number of AF fibroblasts expressing functional Claire Poulet, Imperial College London, Nav1.5 channels. Strikingly Na+ currents were considerably larger in AF cells. National Heart and Lung Institute, London, UK Blocking Na+ channels in culture with tetrodotoxin did not affect prolifera- tion, migration, or differentiation in neither SR nor AF cells.