title: Tissue inhibitor of metalloproteinases 3-dependent microvascular endothelial cell barrier function is disrupted under septic conditions.
abstract: Sepsis is associated with dysfunction of microvascular endothelial cells (MVEC) leading to tissue edema and multiple organ dysfunction. Metalloproteinases can regulate MVEC function through processing of cell surface proteins, and tissue inhibitor of metalloproteinases 3 (TIMP3) regulates metalloproteinase activity in the lung following injury. We hypothesize that TIMP3 promotes normal pulmonary MVEC barrier function through inhibition of metalloproteinase activity. Naive Timp3(-/-) mice had significantly higher basal pulmonary microvascular Evans blue (EB) dye-labeled albumin leak vs. wild-type (WT) mice. Additionally, cecal-ligation/perforation (CLP)-induced sepsis significantly increased pulmonary microvascular EB-labeled albumin leak in WT but not Timp3(-/-) mice. Similarly, PBS-treated isolated MVEC monolayers from Timp3(-/-) mice displayed permeability barrier dysfunction vs. WT MVEC, evidenced by lower transendothelial electrical resistance and greater trans-MVEC flux of fluorescein-dextran and EB-albumin. Cytomix (equimolar interferon γ, tumor necrosis factor α, and interleukin 1β) treatment of WT MVEC induced significant barrier dysfunction (by all three methods), and was associated with a time-dependent decrease in TIMP3 mRNA and protein levels. Additionally, basal Timp3(-/-) MVEC barrier dysfunction was associated with disrupted MVEC surface VE-cadherin localization, and both barrier dysfunction and VE-cadherin localization were rescued by treatment with GM6001, a synthetic metalloproteinase inhibitor. TIMP3 promotes normal MVEC barrier function, at least partially, through inhibition of metalloproteinase-dependent disruption of adherens junctions, and septic downregulation of TIMP3 may contribute to septic MVEC barrier dysfunction.
authors.affiliation: Centre for Critical Illness Research, Lawson Health Research Institute, London, Ontario, Canada; Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.
authors.forename: Valerie
authors.initials: V
authors.lastname: Arpino
authors.affiliation: Centre for Critical Illness Research, Lawson Health Research Institute, London, Ontario, Canada; Division of Respirology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada; Department of Medicine, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada; and.
authors.forename: Sanjay
authors.initials: S
authors.lastname: Mehta
authors.affiliation: Centre for Critical Illness Research, Lawson Health Research Institute, London, Ontario, Canada; Department of Medicine, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada; and.
authors.forename: Lefeng
authors.initials: L
authors.lastname: Wang
authors.affiliation: Centre for Critical Illness Research, Lawson Health Research Institute, London, Ontario, Canada; Department of Medicine, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada; and.
authors.forename: Ryan
authors.initials: R
authors.lastname: Bird
authors.affiliation: Centre for Critical Illness Research, Lawson Health Research Institute, London, Ontario, Canada;
authors.forename: Marta
authors.initials: M
authors.lastname: Rohan
authors.affiliation: Centre for Critical Illness Research, Lawson Health Research Institute, London, Ontario, Canada; Department of Medicine, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada; and.
authors.forename: Cynthia
authors.initials: C
authors.lastname: Pape
authors.affiliation: Centre for Critical Illness Research, Lawson Health Research Institute, London, Ontario, Canada; Division of Respirology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada; Department of Medicine, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada; and Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada sgill8@uwo.ca.
authors.forename: Sean E
authors.initials: SE
authors.lastname: Gill
mesh_terms: D022005:Adherens Junctions / Q000378:metabolism; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D015820:Cadherins / Q000378:metabolism; D002199:Capillary Permeability / Q000187:drug effects; D002478:Cells, Cultured; D016207:Cytokines / Q000494:pharmacology; D004151:Dipeptides / Q000494:pharmacology; D004195:Disease Models, Animal; D042783:Endothelial Cells / Q000378:metabolism*; D005838:Genotype; D008168:Lung / Q000098:blood supply*; D008297:Male; D061965:Matrix Metalloproteinase Inhibitors / Q000494:pharmacology; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D055806:Microvessels / Q000187:drug effects / Q000378:metabolism* / Q000503:physiopathology; D010641:Phenotype; D011654:Pulmonary Edema / Q000235:genetics / Q000378:metabolism* / Q000503:physiopathology; D018805:Sepsis / Q000235:genetics / Q000378:metabolism* / Q000503:physiopathology; D013997:Time Factors; D019717:Tissue Inhibitor of Metalloproteinase-3 / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D000099152:Cadherin 5
chemical_list: D015703:Antigens, CD; D015820:Cadherins; D016207:Cytokines; D004151:Dipeptides; D061965:Matrix Metalloproteinase Inhibitors; D019717:Tissue Inhibitor of Metalloproteinase-3; D000099152:Cadherin 5; C078131:N-(2(R)-2-(hydroxamidocarbonylmethyl)-4-methylpentanoyl)-L-tryptophan methylamide
keywords: sepsis; tissue inhibitor of metalloproteinases; vascular leak