title: Protective effects of high-molecular weight polyethylene glycol (PEG) in human lung endothelial cell barrier regulation: role of actin cytoskeletal rearrangement.
abstract: Acute lung injury represents the result of multiple pathways initiated by local or systemic insults and is characterized by profound vascular permeability, pulmonary edema, and life-threatening respiratory failure. Permeability-reducing therapies are of potential clinical utility but are currently unavailable. We hypothesized that polyethylene glycol (PEG) compounds, inert and non-toxic polymers that serve as a surrogate mucin lining in intestinal epithelium, may attenuate agonist-mediated lung endothelial cell (EC) barrier dysfunction. High molecular weight PEG (PEG15-20) produced rapid, dose-dependent increases in transendothelial electrical resistance (TER) in human lung endothelium cultured on gold microelectrodes, reflecting increased paracellular integrity. The maximal effective concentration of 8% PEG induced a sustained 125% increase in TER (40 h), results similar to barrier-enhancing agonists such as sphingosine 1-phosphate (40% increase in TER). Maximal PEG barrier enhancement was achieved at 45-60 min and PEG effectively reversed both thrombin- and LPS-induced EC barrier dysfunction. Consistent with the increase in TER, immunofluorescent studies demonstrated that PEG produced significant cytoskeletal rearrangement with formation of well-defined cortical actin rings and lamellipodia containing the actin-binding proteins, cortactin and MLCK, known participants in cell-matrix and cell-cell junctional adhesion. Finally, PEG challenge induced rapid alterations in levels of MAP kinase and MLC phosphorylation. In summary, PEG joins a number of EC barrier-regulatory agents which rapidly activate barrier-enhancing signal transduction pathways which target the cytoskeleton and provides a potential therapeutic strategy in inflammatory lung injury.
authors.affiliation: Section of Pulmonary and Critical Medicine, Department of Medicine, University of Chicago Pritzker School of Medicine, 5841 S. Maryland Avenue, MC 6092 Chicago, IL 60637-1470, USA.
authors.forename: Eddie T
authors.initials: ET
authors.lastname: Chiang
authors.forename: Sara M
authors.initials: SM
authors.lastname: Camp
authors.forename: Steven M
authors.initials: SM
authors.lastname: Dudek
authors.forename: Mary E
authors.initials: ME
authors.lastname: Brown
authors.forename: Peter V
authors.initials: PV
authors.lastname: Usatyuk
authors.forename: Olga
authors.initials: O
authors.lastname: Zaborina
authors.forename: John C
authors.initials: JC
authors.lastname: Alverdy
authors.forename: Joe G N
authors.initials: JG
authors.lastname: Garcia
mesh_terms: D000199:Actins / Q000378:metabolism*; D055371:Acute Lung Injury / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D022005:Adherens Junctions / Q000187:drug effects / Q000378:metabolism; D020013:Calcium Signaling / Q000187:drug effects; D002478:Cells, Cultured; D003599:Cytoskeleton / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D017097:Electric Impedance; D042783:Endothelial Cells / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D008168:Lung / Q000098:blood supply / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism; D008856:Microscopy, Fluorescence; D018715:Microscopy, Video; D008970:Molecular Weight; D011092:Polyethylene Glycols / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013917:Thrombin / Q000494:pharmacology
chemical_list: D000199:Actins; D011092:Polyethylene Glycols; D013917:Thrombin; D013755:Tetradecanoylphorbol Acetate