The purinergic receptor subtype P2Y 2 mediates chemotaxis of neutrophils and fibroblasts in fibrotic lung disease

// Tobias Muller 1, 2, * , Susanne Fay 1, * , Rodolfo Paula Vieira 1, * , Harry Karmouty-Quintana 3 , Sanja Cicko 1 , Korcan Ayata 1 , Gernot Zissel 1 , Torsten Goldmann 4 , Giuseppe Lungarella 5 , Davide Ferrari 6 , Francesco Di Virgilio 6 , Bernard Robaye 7 , Jean-Marie Boeynaems 7 , Michael R. Blackburn 3 , Marco Idzko 1 1 University Hospital Freiburg, Department of Pneumology, Freiburg, Germany 2 University Hospital RWTH Aachen, Division of Pneumology, Aachen, Germany 3 Department of Biochemistry and Molecular Biology, Houston Medical School, University of Texas, Houston, USA 4 Research Center Borstel, Clinical and Experimental Pathology, Borstel, Germany 5 Department of Physiopathology and Experimental Medicine, University of Siena, Siena, Italy 6 Department of Experimental and Diagnostic Medicine, Section of General Pathology and Interdisciplinary Center for the Study of Inflammation (ICSI), University of Ferrara, Ferrara, Italy 7 IRIBHM and Erasme Hospital, Universite Libre de Bruxelles, Brussels, Belgium * These authors contributed equally to this work Correspondence to: Tobias Muller, email: tobmueller@ukaachen.de Keywords: ATP, chemotaxis, neutrophils, nucleotides, pulmonary fibrosis Received: November 16, 2016      Accepted: March 10, 2017      Published: March 21, 2017 ABSTRACT Idiopathic pulmonary fibrosis (IPF) is a devastating disease with few available treatment options. Recently, the involvement of purinergic receptor subtypes in the pathogenesis of different lung diseases has been demonstrated. Here we investigated the role of the purinergic receptor subtype P2Y 2 in the context of fibrotic lung diseases. The concentration of different nucleotides was measured in the broncho-alveolar lavage (BAL) fluid derived from IPF patients and animals with bleomycin-induced pulmonary fibrosis. In addition expression of P2Y 2 receptors by different cell types was determined. To investigate the functional relevance of P2Y 2 receptors for the pathogenesis of the disease the bleomycin model of pulmonary fibrosis was used. Finally, experiments were performed in pursuit of the involved mechanisms. Compared to healthy individuals or vehicle treated animals, extracellular nucleotide levels in the BAL fluid were increased in patients with IPF and in mice after bleomycin administration, paralleled by a functional up-regulation of P2Y 2 R expression. Both bleomycin-induced inflammation and fibrosis were reduced in P2Y 2 R-deficient compared to wild type animals. Mechanistic studies demonstrated that recruitment of neutrophils into the lungs, proliferation and migration of lung fibroblasts as well as IL6 production are key P2Y 2 R mediated processes. Our results clearly demonstrate the involvement of P2Y 2 R subtypes in the pathogenesis of fibrotic lung diseases in humans and mice and hence support the development of selective P2Y 2 R antagonists for the treatment of IPF.