title: Endothelial apoptosis in pulmonary hypertension is controlled by a microRNA/programmed cell death 4/caspase-3 axis.
abstract: Pulmonary endothelial cell apoptosis is a transient, yet defining pathogenic event integral to the onset of many pulmonary vascular diseases such as pulmonary hypertension (PH). However, there is a paucity of information concerning the molecular pathway(s) that control pulmonary arterial endothelial cell apoptosis. Here, we introduce a molecular axis that when functionally active seems to induce pulmonary arterial endothelial cell apoptosis in vitro and PH in vivo. In response to apoptotic stimuli, human pulmonary arterial endothelial cells exhibited robust induction of a programmed cell death 4 (PDCD4)/caspase-3/apoptotic pathway that was reversible by direct PDCD4 silencing. Indirectly, this pathway was also repressed by delivery of a microRNA-21 mimic. In vivo, genetic deletion of microRNA-21 in mice (miR-21(-/-) mice) resulted in functional activation of the PDCD4/caspase-3 axis in the pulmonary tissues, leading to the onset of progressive PH. Conversely, microRNA-21-overexpressing mice (CAG-microRNA-21 mice) exhibited reduced PDCD4 expression in pulmonary tissues and were partially resistant to PH in response to chronic hypoxia plus SU 5416 injury. Furthermore, direct PDCD4 knockout in mice (PDCD4(-/-) mice) potently blocked pulmonary caspase-3 activation and the development of chronic hypoxia plus SU 5416 PH, confirming its importance in disease onset. Broadly, these findings support the existence of a microRNA-21-responsive PDCD4/caspase-3 pathway in the pulmonary tissues that when active serves to promote endothelial apoptosis in vitro and PH in vivo.
authors.affiliation: From the Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom (K.W., Y.D., P.C., E.W., R.A.M., H.S., M.R.M., A.H.B.); Solid Tumor Division, St. Jude Children's Research Hospital, Memphis, TN (M.E.H.); MiRagen Therapeutics, Boulder, CO (E.V.R.); and Division of Respiratory Medicine, Addenbrooke's Hospital, University of Cambridge, School of Clinical Medicine, Cambridge, United Kingdom (N.W.M.).
authors.forename: Kevin
authors.initials: K
authors.lastname: White
authors.affiliation: From the Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom (K.W., Y.D., P.C., E.W., R.A.M., H.S., M.R.M., A.H.B.); Solid Tumor Division, St. Jude Children's Research Hospital, Memphis, TN (M.E.H.); MiRagen Therapeutics, Boulder, CO (E.V.R.); and Division of Respiratory Medicine, Addenbrooke's Hospital, University of Cambridge, School of Clinical Medicine, Cambridge, United Kingdom (N.W.M.).
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Dempsie
authors.affiliation: From the Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom (K.W., Y.D., P.C., E.W., R.A.M., H.S., M.R.M., A.H.B.); Solid Tumor Division, St. Jude Children's Research Hospital, Memphis, TN (M.E.H.); MiRagen Therapeutics, Boulder, CO (E.V.R.); and Division of Respiratory Medicine, Addenbrooke's Hospital, University of Cambridge, School of Clinical Medicine, Cambridge, United Kingdom (N.W.M.).
authors.forename: Paola
authors.initials: P
authors.lastname: Caruso
authors.affiliation: From the Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom (K.W., Y.D., P.C., E.W., R.A.M., H.S., M.R.M., A.H.B.); Solid Tumor Division, St. Jude Children's Research Hospital, Memphis, TN (M.E.H.); MiRagen Therapeutics, Boulder, CO (E.V.R.); and Division of Respiratory Medicine, Addenbrooke's Hospital, University of Cambridge, School of Clinical Medicine, Cambridge, United Kingdom (N.W.M.).
authors.forename: Emma
authors.initials: E
authors.lastname: Wallace
authors.affiliation: From the Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom (K.W., Y.D., P.C., E.W., R.A.M., H.S., M.R.M., A.H.B.); Solid Tumor Division, St. Jude Children's Research Hospital, Memphis, TN (M.E.H.); MiRagen Therapeutics, Boulder, CO (E.V.R.); and Division of Respiratory Medicine, Addenbrooke's Hospital, University of Cambridge, School of Clinical Medicine, Cambridge, United Kingdom (N.W.M.).
authors.forename: Robert A
authors.initials: RA
authors.lastname: McDonald
authors.affiliation: From the Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom (K.W., Y.D., P.C., E.W., R.A.M., H.S., M.R.M., A.H.B.); Solid Tumor Division, St. Jude Children's Research Hospital, Memphis, TN (M.E.H.); MiRagen Therapeutics, Boulder, CO (E.V.R.); and Division of Respiratory Medicine, Addenbrooke's Hospital, University of Cambridge, School of Clinical Medicine, Cambridge, United Kingdom (N.W.M.).
authors.forename: Hannah
authors.initials: H
authors.lastname: Stevens
authors.affiliation: From the Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom (K.W., Y.D., P.C., E.W., R.A.M., H.S., M.R.M., A.H.B.); Solid Tumor Division, St. Jude Children's Research Hospital, Memphis, TN (M.E.H.); MiRagen Therapeutics, Boulder, CO (E.V.R.); and Division of Respiratory Medicine, Addenbrooke's Hospital, University of Cambridge, School of Clinical Medicine, Cambridge, United Kingdom (N.W.M.).
authors.forename: Mark E
authors.initials: ME
authors.lastname: Hatley
authors.affiliation: From the Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom (K.W., Y.D., P.C., E.W., R.A.M., H.S., M.R.M., A.H.B.); Solid Tumor Division, St. Jude Children's Research Hospital, Memphis, TN (M.E.H.); MiRagen Therapeutics, Boulder, CO (E.V.R.); and Division of Respiratory Medicine, Addenbrooke's Hospital, University of Cambridge, School of Clinical Medicine, Cambridge, United Kingdom (N.W.M.).
authors.forename: Eva
authors.initials: E
authors.lastname: Van Rooij
authors.affiliation: From the Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom (K.W., Y.D., P.C., E.W., R.A.M., H.S., M.R.M., A.H.B.); Solid Tumor Division, St. Jude Children's Research Hospital, Memphis, TN (M.E.H.); MiRagen Therapeutics, Boulder, CO (E.V.R.); and Division of Respiratory Medicine, Addenbrooke's Hospital, University of Cambridge, School of Clinical Medicine, Cambridge, United Kingdom (N.W.M.).
authors.forename: Nicholas W
authors.initials: NW
authors.lastname: Morrell
authors.affiliation: From the Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom (K.W., Y.D., P.C., E.W., R.A.M., H.S., M.R.M., A.H.B.); Solid Tumor Division, St. Jude Children's Research Hospital, Memphis, TN (M.E.H.); MiRagen Therapeutics, Boulder, CO (E.V.R.); and Division of Respiratory Medicine, Addenbrooke's Hospital, University of Cambridge, School of Clinical Medicine, Cambridge, United Kingdom (N.W.M.).
authors.forename: Margaret R
authors.initials: MR
authors.lastname: MacLean
authors.affiliation: From the Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom (K.W., Y.D., P.C., E.W., R.A.M., H.S., M.R.M., A.H.B.); Solid Tumor Division, St. Jude Children's Research Hospital, Memphis, TN (M.E.H.); MiRagen Therapeutics, Boulder, CO (E.V.R.); and Division of Respiratory Medicine, Addenbrooke's Hospital, University of Cambridge, School of Clinical Medicine, Cambridge, United Kingdom (N.W.M.). Andrew.H.Baker@glasgow.ac.uk.
authors.forename: Andrew H
authors.initials: AH
authors.lastname: Baker
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism*; D053148:Caspase 3 / Q000378:metabolism*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D042783:Endothelial Cells / Q000378:metabolism*; D006801:Humans; D006976:Hypertension, Pulmonary / Q000378:metabolism*; D051379:Mice; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism*
chemical_list: D051017:Apoptosis Regulatory Proteins; C531950:MIRN21 microRNA, mouse; D035683:MicroRNAs; C498443:Pdcd4 protein, mouse; D016601:RNA-Binding Proteins; D053148:Caspase 3
keywords: PDCD4 protein, human; apoptosis; endothelium; hypertension, pulmonary; microRNAs