ATP13A3 variants promote pulmonary arterial hypertension by disrupting polyamine transport.
Bin Liu, Mujahid Azfar, Ekaterina Legchenko, James A West, Shaun Martin, Chris Van den Haute, Veerle Baekelandt, John Wharton, Luke Howard, Martin R Wilkins, Peter Vangheluwe, Nicholas W Morrell, Paul D Upton
Author Information
Bin Liu: Section of Cardio and Respiratory Medicine, Department of Medicine, Victor Phillip Dahdaleh Heart and Lung Research Institute, Papworth Road, Cambridge CB2 0BB, UK.
Mujahid Azfar: Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, Box 802, 3000 Leuven, Belgium.
Ekaterina Legchenko: Section of Cardio and Respiratory Medicine, Department of Medicine, Victor Phillip Dahdaleh Heart and Lung Research Institute, Papworth Road, Cambridge CB2 0BB, UK.
James A West: Cambridge Institute of Therapeutic Immunology and Infectious Disease, Jeffrey Cheah Biomedical Centre, Puddicombe Way, Cambridge CB2 0AW, UK.
Shaun Martin: Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, Box 802, 3000 Leuven, Belgium.
Chris Van den Haute: Laboratory for Neurobiology and Gene Therapy, Department of Neurosciences, KU Leuven, Herestraat 49, Box 1023, 3000 Leuven, Belgium.
Veerle Baekelandt: Laboratory for Neurobiology and Gene Therapy, Department of Neurosciences, KU Leuven, Herestraat 49, Box 1023, 3000 Leuven, Belgium.
John Wharton: Faculty of Medicine, National Heart and Lung Institute, ICTEM Building, Imperial College, Du Cane Road, London W12 0NN, UK.
Luke Howard: Faculty of Medicine, National Heart and Lung Institute, ICTEM Building, Imperial College, Du Cane Road, London W12 0NN, UK.
Martin R Wilkins: Faculty of Medicine, National Heart and Lung Institute, ICTEM Building, Imperial College, Du Cane Road, London W12 0NN, UK.
Peter Vangheluwe: Department of Biochemistry and Cambridge Systems Biology Centre, University of Cambridge, Cambridge, UK.
Nicholas W Morrell: Section of Cardio and Respiratory Medicine, Department of Medicine, Victor Phillip Dahdaleh Heart and Lung Research Institute, Papworth Road, Cambridge CB2 0BB, UK.
Paul D Upton: Section of Cardio and Respiratory Medicine, Department of Medicine, Victor Phillip Dahdaleh Heart and Lung Research Institute, Papworth Road, Cambridge CB2 0BB, UK. ORCID
AIMS: Potential loss-of-function variants of ATP13A3, the gene encoding a P5B-type transport ATPase of undefined function, were recently identified in patients with pulmonary arterial hypertension (PAH). ATP13A3 is implicated in polyamine transport but its function has not been fully elucidated. In this study, we sought to determine the biological function of ATP13A3 in vascular endothelial cells (ECs) and how PAH-associated variants may contribute to disease pathogenesis. METHODS AND RESULTS: We studied the impact of ATP13A3 deficiency and overexpression in EC models [human pulmonary ECs, blood outgrowth ECs (BOECs), and human microvascular EC 1], including a PAH patient-derived BOEC line harbouring an ATP13A3 variant (LK726X). We also generated mice harbouring an Atp13a3 variant analogous to a human disease-associated variant to establish whether these mice develop PAH. ATP13A3 localized to the recycling endosomes of human ECs. Knockdown of ATP13A3 in ECs generally reduced the basal polyamine content and altered the expression of enzymes involved in polyamine metabolism. Conversely, overexpression of wild-type ATP13A3 increased polyamine uptake. Functionally, loss of ATP13A3 was associated with reduced EC proliferation, increased apoptosis in serum starvation, and increased monolayer permeability to thrombin. The assessment of five PAH-associated missense ATP13A3 variants (L675V, M850I, V855M, R858H, and L956P) confirmed loss-of-function phenotypes represented by impaired polyamine transport and dysregulated EC function. Furthermore, mice carrying a heterozygous germline Atp13a3 frameshift variant representing a human variant spontaneously developed a PAH phenotype, with increased pulmonary pressures, right ventricular remodelling, and muscularization of pulmonary vessels. CONCLUSION: We identify ATP13A3 as a polyamine transporter controlling polyamine homeostasis in ECs, a deficiency of which leads to EC dysfunction and predisposes to PAH. This suggests a need for targeted therapies to alleviate the imbalances in polyamine homeostasis and EC dysfunction in PAH.
