Influence of the endothelin receptor antagonists Ambrisentan and Bosentan on TNFa induced GM-CSF expression in human airway smooth muscle cells

Background: Human airway smooth muscle cells (HASMCs) have an important part in chronic inflammatory airway diseases and lung fibrosis for whose establishment TNFα and GM-CSF have a key role. We were able to show TNFα induced GM-CSF expression is regulated by endothelin-1 (ET-1) (Thorax, 2009;64:1044–52). This hints at an anti-inflammatory effect of endothelin receptor antagonists (ERA). Their efficacy in idiopathic pulmonary fibrosis is the subject of ongoing clinical trials. So far, few studies comparing the efficacy of a selective blockade of the endothelin receptor subtype A (ETAR) against the dual blockade…