title: Upregulated copper transporters in hypoxia-induced pulmonary hypertension.
abstract: Pulmonary vascular remodeling and increased arterial wall stiffness are two major causes for the elevated pulmonary vascular resistance and pulmonary arterial pressure in patients and animals with pulmonary hypertension. Cellular copper (Cu) plays an important role in angiogenesis and extracellular matrix remodeling; increased Cu in vascular smooth muscle cells has been demonstrated to be associated with atherosclerosis and hypertension in animal experiments. In this study, we show that the Cu-uptake transporter 1, CTR1, and the Cu-efflux pump, ATP7A, were both upregulated in the lung tissues and pulmonary arteries of mice with hypoxia-induced pulmonary hypertension. Hypoxia also significantly increased expression and activity of lysyl oxidase (LOX), a Cu-dependent enzyme that causes crosslinks of collagen and elastin in the extracellular matrix. In vitro experiments show that exposure to hypoxia or treatment with cobalt (CoCl2) also increased protein expression of CTR1, ATP7A, and LOX in pulmonary arterial smooth muscle cells (PASMC). In PASMC exposed to hypoxia or treated with CoCl2, we also confirmed that the Cu transport is increased using 64Cu uptake assays. Furthermore, hypoxia increased both cell migration and proliferation in a Cu-dependent manner. Downregulation of hypoxia-inducible factor 1α (HIF-1α) with siRNA significantly attenuated hypoxia-mediated upregulation of CTR1 mRNA. In summary, the data from this study indicate that increased Cu transportation due to upregulated CTR1 and ATP7A in pulmonary arteries and PASMC contributes to the development of hypoxia-induced pulmonary hypertension. The increased Cu uptake and elevated ATP7A also facilitate the increase in LOX activity and thus the increase in crosslink of extracellular matrix, and eventually leading to the increase in pulmonary arterial stiffness.
authors.affiliation: Department of Medicine, Section of Pulmonary, Critical Care, Sleep and Allergy Medicine, University of Illinois at Chicago, Chicago, Illinois, United States of America.
authors.forename: Adriana M
authors.initials: AM
authors.lastname: Zimnicka
authors.affiliation: Department of Medicine, Section of Pulmonary, Critical Care, Sleep and Allergy Medicine, University of Illinois at Chicago, Chicago, Illinois, United States of America.
authors.forename: Haiyang
authors.initials: H
authors.lastname: Tang
authors.affiliation: Department of Medicine, Section of Pulmonary, Critical Care, Sleep and Allergy Medicine, University of Illinois at Chicago, Chicago, Illinois, United States of America.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Guo
authors.affiliation: Department of Medicine, Section of Pulmonary, Critical Care, Sleep and Allergy Medicine, University of Illinois at Chicago, Chicago, Illinois, United States of America.
authors.forename: Frank K
authors.initials: FK
authors.lastname: Kuhr
authors.affiliation: Department of Medicine, Section of Pulmonary, Critical Care, Sleep and Allergy Medicine, University of Illinois at Chicago, Chicago, Illinois, United States of America; Department of Pharmacology, University of Illinois at Chicago, Chicago, Illinois, United States of America.
authors.forename: Myung-Jin
authors.initials: MJ
authors.lastname: Oh
authors.affiliation: Department of Medicine, Section of Pulmonary, Critical Care, Sleep and Allergy Medicine, University of Illinois at Chicago, Chicago, Illinois, United States of America.
authors.forename: Jun
authors.initials: J
authors.lastname: Wan
authors.affiliation: Department of Medicine, Section of Pulmonary, Critical Care, Sleep and Allergy Medicine, University of Illinois at Chicago, Chicago, Illinois, United States of America.
authors.forename: Jiwang
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Medicine, Section of Pulmonary, Critical Care, Sleep and Allergy Medicine, University of Illinois at Chicago, Chicago, Illinois, United States of America.
authors.forename: Kimberly A
authors.initials: KA
authors.lastname: Smith
authors.affiliation: Department of Medicine, Section of Pulmonary, Critical Care, Sleep and Allergy Medicine, University of Illinois at Chicago, Chicago, Illinois, United States of America.
authors.forename: Dustin R
authors.initials: DR
authors.lastname: Fraidenburg
authors.affiliation: Department of Medicine, Section of Pulmonary, Critical Care, Sleep and Allergy Medicine, University of Illinois at Chicago, Chicago, Illinois, United States of America.
authors.forename: Moumita S R
authors.initials: MS
authors.lastname: Choudhury
authors.affiliation: Department of Medicine, Section of Pulmonary, Critical Care, Sleep and Allergy Medicine, University of Illinois at Chicago, Chicago, Illinois, United States of America; Department of Pharmacology, University of Illinois at Chicago, Chicago, Illinois, United States of America.
authors.forename: Irena
authors.initials: I
authors.lastname: Levitan
authors.affiliation: Department of Medicine, Section of Pulmonary, Critical Care, Sleep and Allergy Medicine, University of Illinois at Chicago, Chicago, Illinois, United States of America.
authors.forename: Roberto F
authors.initials: RF
authors.lastname: Machado
authors.affiliation: Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, Illinois, United States of America.
authors.forename: Jack H
authors.initials: JH
authors.lastname: Kaplan
authors.affiliation: Department of Medicine, Section of Pulmonary, Critical Care, Sleep and Allergy Medicine, University of Illinois at Chicago, Chicago, Illinois, United States of America; Department of Pharmacology, University of Illinois at Chicago, Chicago, Illinois, United States of America; Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, Illinois, United States of America.
authors.forename: Jason X-J
authors.initials: JX
authors.lastname: Yuan
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D027682:Cation Transport Proteins / Q000235:genetics* / Q000378:metabolism; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002614:Chelating Agents / Q000494:pharmacology; D003035:Cobalt / Q000494:pharmacology; D003300:Copper / Q000378:metabolism*; D015536:Down-Regulation / Q000187:drug effects / Q000235:genetics; D055785:Gene Knockdown Techniques; D006801:Humans; D006976:Hypertension, Pulmonary / Q000209:etiology* / Q000235:genetics* / Q000473:pathology; D000860:Hypoxia / Q000150:complications* / Q000235:genetics; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism; D008168:Lung / Q000473:pathology; D008297:Male; D008810:Mice, Inbred C57BL; D032389:Myocytes, Smooth Muscle / Q000378:metabolism; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D008249:Protein-Lysine 6-Oxidase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D011651:Pulmonary Artery / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects / Q000235:genetics*
chemical_list: D027682:Cation Transport Proteins; D002614:Chelating Agents; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D018809:Proliferating Cell Nuclear Antigen; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D003035:Cobalt; D003300:Copper; D008249:Protein-Lysine 6-Oxidase; C018021:cobaltous chloride