title: Bosentan inhibits cigarette smoke-induced endothelin receptor expression in pulmonary arteries.
abstract: The endothelin (ET) system contributes to lung vascular tension and remodelling in smokers and chronic obstructive pulmonary disease (COPD) patients. This study examined the effect of cigarette smoke (CS) on ET receptor A (ET(A)) and B (ET(B)) expression in human pulmonary artery smooth muscle cells (HPASMCs) and human small intrapulmonary arteries, as well as their functional consequences. CS extract (CSE) increased ET(A) and ET(B) expression in HPASMCs and small intrapulmonary arteries, which was attenuated by bosentan, the ET(A) antagonist BQ123 and the ET(B) antagonist BQ788, and by blocking ET-1 with a monoclonal antibody against ET-1, suggesting a feed-forward mechanism mediated by ET-1 release. ET receptor (ETR) antagonism attenuated the CSE-induced HPASMC proliferation. Furthermore, CSE exposure increased the acute ET-1-induced small intrapulmonary artery contraction, which was attenuated by bosentan, BQ123 and BQ788. Pulmonary arteries from smokers and COPD patients showed a higher expression of ET(A) and ET(B) than those of nonsmoker patients. These results show a novel mechanism by which ETR blockade attenuates CS-induced ETR overexpression and, subsequently, small intrapulmonary artery tension. These data may be of potential value to explain therapeutic effects of bosentan in some forms of disproportionate pulmonary hypertension in COPD patients.
authors.affiliation: Clinic Research Unit, University General Hospital Consortium, Valencia, Spain. xmilara@hotmail.com
authors.forename: J
authors.initials: J
authors.lastname: Milara
authors.forename: E
authors.initials: E
authors.lastname: Gabarda
authors.forename: G
authors.initials: G
authors.lastname: Juan
authors.forename: J L
authors.initials: JL
authors.lastname: Ortiz
authors.forename: R
authors.initials: R
authors.lastname: Guijarro
authors.forename: M
authors.initials: M
authors.lastname: Martorell
authors.forename: E J
authors.initials: EJ
authors.lastname: Morcillo
authors.forename: J
authors.initials: J
authors.lastname: Cortijo
mesh_terms: D000368:Aged; D000959:Antihypertensive Agents / Q000627:therapeutic use; D019898:Autocrine Communication / Q000187:drug effects / Q000502:physiology; D000077300:Bosentan; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D006801:Humans; D006976:Hypertension, Pulmonary / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D020935:MAP Kinase Signaling System / Q000502:physiology; D008875:Middle Aged; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D011651:Pulmonary Artery / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy / Q000378:metabolism / Q000503:physiopathology; D017382:Reactive Oxygen Species / Q000378:metabolism; D044022:Receptor, Endothelin A / Q000235:genetics*; D044023:Receptor, Endothelin B / Q000235:genetics*; D012907:Smoking / Q000378:metabolism / Q000503:physiopathology*; D013449:Sulfonamides / Q000627:therapeutic use*; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology; D014661:Vasoconstriction / Q000187:drug effects / Q000502:physiology; D020742:rhoA GTP-Binding Protein / Q000378:metabolism
chemical_list: D000959:Antihypertensive Agents; D017382:Reactive Oxygen Species; D044022:Receptor, Endothelin A; D044023:Receptor, Endothelin B; D013449:Sulfonamides; D020742:rhoA GTP-Binding Protein; D000077300:Bosentan