tailieunhanh - Báo cáo khoa học: Membrane compartments and purinergic signalling: occurrence and function of P2X receptors in lung Kathrin Barth and Michael Kasper

P2X receptors are cation-selective ion channels activated by extracellular ATP. They form homo- and heterotrimeric complexes that differ in their functional properties and subcellular localization. These membrane ion channels are also expressed in pulmonary epithelial cells. | ỊFEBS Journal MINIREVIEW Membrane compartments and purinergic signalling occurrence and function of P2X receptors in lung Kathrin Barth and Michael Kasper Institute of Anatomy MedicalFaculty CarlGustav Carus Dresden University of Technology Germany Keywords alveolar epithelium ATP caveolin-1 ion channel lipid raft lung injury mouse lung P2X receptor P2X7 receptor knockout pulmonary fibrosis Correspondence K. Barth Institute of Anatomy Medical Faculty Carl Gustav Carus Dresden University of Technology Fiedlerstr. 42 D-01307 Dresden Germany Fax 49 351 458 6303 Tel 49 351 458 6076 E-mail P2X receptors are cation-selective ion channels activated by extracellular ATP. They form homo- and heterotrimeric complexes that differ in their functional properties and subcellular localization. These membrane ion channels are also expressed in pulmonary epithelial cells. Recent work indicates that alveolar epithelial type I cells selectively express P2X4 and P2X7 receptor subtypes in addition to a large number of other ion channels present in the alveolar epithelium. Up- or downregulation of their expression is associated with several disease states. This minireview analyses the role of P2X receptors and of extracellular ATP and adenosine in lung disease the relationship of P2X receptors to other ion channels in the alveolar epithelium and their distribution in lipid rafts caveolae. Received 15 July 2008 revised 9 October 2008 accepted 11 November 2008 doi Although most studies on purinergic signalling mechanisms have been performed in the nervous and immune systems recent reports have also shown the expression and putative function of P2X receptors in epithelial including pulmonary epithelial cells. Lung epithelial cells line the surface of the conducting and respiratory systems. The most distal alveolar epithelial cells represent polarized epithelia and are involved in barrier air-blood and transport functions. The .