title: Human macrophage ATP7A is localized in the trans-Golgi apparatus, controls intracellular copper levels, and mediates macrophage responses to dermal wounds.
abstract: The copper transporter ATP7A has attracted significant attention since the discovery of its gene mutation leading to human Menkes disease. We previously reported that ATP7A is highly expressed in the human vasculature and identified a novel vascular function of ATP7A in modulation of the expression and activity of extracellular superoxide dismutase. We recently identified that ATP7A expression in THP-1 cells (a monocyte/macrophage model cell line) plays a role in the oxidation of low density lipoproteins, indicating that it is necessary to further investigate its expression and function in monocytes/macrophages. In the current study, we demonstrated the protein and mRNA expression of ATP7A in human peripheral blood mononuclear cell (PBMC)-derived macrophages and alveolar macrophages. ATP7A was strongly co-localized with the trans-Golgi apparatus in PBMC-derived macrophages. Intracellular copper, detected by synchrotron X-ray fluorescence microscopy, was found to be distributed to the nucleus and cytoplasm in human THP-1 cells. To confirm the role of endogenous ATP7A in macrophage copper homeostasis, we performed inductively coupled plasma mass spectrometry in murine peritoneal macrophages, which showed markedly increased intracellular copper levels in macrophages isolated from ATP7A-deficient mice versus control mice. Moreover, the role of ATP7A in regulating macrophage responses to dermal wounds was studied by introduction of control and ATP7A-downregulated THP-1 cells into dermal wounds of nude mice. Infiltration of THP-1 cells into the wounded area (detected by expression of human macrophage markers MAC2 and CD68) was reduced in response to downregulation of ATP7A, hinting decreased macrophage accumulation subsequent to dermal wounds. In summary, alongside our previous studies, these findings indicate that human macrophage ATP7A is localized in the trans-Golgi apparatus, regulates intracellular copper levels, and mediates macrophage responses to a dermal wound.
authors.affiliation: Division of Cardiovascular Disease, Department of Internal Medicine, University of Cincinnati, Cincinnati, OH 45267, USA.
authors.forename: Ha Won
authors.initials: HW
authors.lastname: Kim
authors.forename: Qilin
authors.initials: Q
authors.lastname: Chan
authors.forename: Scott E
authors.initials: SE
authors.lastname: Afton
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Caruso
authors.forename: Barry
authors.initials: B
authors.lastname: Lai
authors.forename: Neal L
authors.initials: NL
authors.lastname: Weintraub
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Qin
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D015703:Antigens, CD / Q000096:biosynthesis; D015214:Antigens, Differentiation, Myelomonocytic / Q000096:biosynthesis; D027682:Cation Transport Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D003300:Copper / Q000378:metabolism*; D000073840:Copper-Transporting ATPases; D005260:Female; D006056:Golgi Apparatus / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D018969:Insulin-Like Growth Factor Binding Proteins / Q000096:biosynthesis; D008264:Macrophages / Q000276:immunology / Q000378:metabolism*; D017737:Macrophages, Peritoneal / Q000276:immunology / Q000378:metabolism; D008297:Male; D051379:Mice; D008819:Mice, Nude; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012867:Skin / Q000276:immunology / Q000293:injuries*; D021601:trans-Golgi Network / Q000378:metabolism*; D000097382:CD68 Molecule
chemical_list: D000251:Adenosine Triphosphatases; D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D027682:Cation Transport Proteins; D003300:Copper; D000073840:Copper-Transporting ATPases; D018969:Insulin-Like Growth Factor Binding Proteins; D012333:RNA, Messenger; C067980:CD68 antigen, human; D000097382:CD68 Molecule; C102529:insulin-like growth factor binding protein-related protein 1; C081184:ATP7A protein, human