title: Caveolae-mediated albumin transcytosis is enhanced in dengue-infected human endothelial cells: A model of vascular leakage in dengue hemorrhagic fever.
abstract: Vascular leakage is a life-threatening complication of dengue virus (DENV) infection. Previously, association between "paracellular" endothelial hyperpermeability and plasma leakage had been extensively investigated. However, whether "transcellular" endothelial leakage is involved in dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS) remained unknown. We thus investigated effects of DENV (serotype 2) infection on transcellular transport of albumin, the main oncotic plasma protein, through human endothelial cell monolayer by Western blotting, immunofluorescence staining, fluorescence imaging, and fluorometry. The data showed that Alexa488-conjugated bovine serum albumin (Alexa488-BSA) was detectable inside DENV2-infected cells and its level was progressively increased during 48-h post-infection. While paracellular transport could be excluded using FITC-conjugated dextran, Alexa488-BSA was progressively increased and decreased in lower and upper chambers of Transwell, respectively. Pretreatment with nystatin, an inhibitor of caveolae-dependent endocytic pathway, significantly decreased albumin internalization into the DENV2-infected cells, whereas inhibitors of other endocytic pathways showed no significant effects. Co-localization of the internalized Alexa488-BSA and caveolin-1 was also observed. Our findings indicate that DENV infection enhances caveolae-mediated albumin transcytosis through human endothelial cells that may ultimately induce plasma leakage from intravascular compartment. Further elucidation of this model in vivo may lead to effective prevention and better therapeutic outcome of DHF/DSS.
authors.affiliation: Molecular Medicine Unit, Office for Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.|Graduate Program in Immunology, Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Chanettee
authors.initials: C
authors.lastname: Chanthick
authors.affiliation: Medical Proteomics Unit, Office for Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.|Center for Research in Complex Systems Science (CRCSS), Mahidol University, Bangkok, Thailand.
authors.forename: Rattiyaporn
authors.initials: R
authors.lastname: Kanlaya
authors.affiliation: Medical Proteomics Unit, Office for Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.|Center for Research in Complex Systems Science (CRCSS), Mahidol University, Bangkok, Thailand.
authors.forename: Rattanaporn
authors.initials: R
authors.lastname: Kiatbumrung
authors.affiliation: Molecular Medicine Unit, Office for Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Sa-Nga
authors.initials: SN
authors.lastname: Pattanakitsakul
authors.affiliation: Medical Proteomics Unit, Office for Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.|Center for Research in Complex Systems Science (CRCSS), Mahidol University, Bangkok, Thailand.
authors.forename: Visith
authors.initials: V
authors.lastname: Thongboonkerd
mesh_terms: D002199:Capillary Permeability; D021941:Caveolae / Q000378:metabolism*; D002460:Cell Line; D003716:Dengue Virus / Q000502:physiology; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism* / Q000821:virology; D006801:Humans; D008954:Models, Biological; D009761:Nystatin / Q000494:pharmacology; D000075462:Serum Albumin, Human / Q000378:metabolism*; D019595:Severe Dengue / Q000378:metabolism*; D057900:Transcytosis / Q000187:drug effects
chemical_list: D009761:Nystatin; D000075462:Serum Albumin, Human