Premium
Tissue Factor Enhances the Alveolar Epithelial Barrier Integrity during Acute Lung Injury
Author(s) -
Sucharski Holly,
Putz Nathan,
Shaver Ciara,
Ware Lorraine,
Bastarache Julie
Publication year - 2018
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2018.32.1_supplement.745.2
Subject(s) - matrigel , a549 cell , chemistry , microbiology and biotechnology , tissue factor , basement membrane , cell adhesion , integrin , pathology , immunology , biology , cell , medicine , biochemistry , coagulation
Introduction We have previously reported that lung epithelial tissue factor (TF) knockout (TF ΔEpi ) mice have increased alveolar capillary barrier permeability. Ultrastructurally, these mouse lungs have profound morphological defects in epithelial attachment to the basement membrane. Adhesion/migration are regulated in part by integrins which bind the extracellular matrix proteins to modulate cytoskeletal dynamics. In cancer cells, TF binds β1 integrin and increases cell migration, a finding that suggests a role for non‐coagulative mechanisms of TF in cell adhesion and migration. We hypothesize that TF‐β1 integrin binding promotes alveolar epithelial barrier integrity through cell adhesion and migration during acute lung injury (ALI). Method TF overexpressing (TF +Epi ) and knockout (TF ΔEpi ) mice, along with TF knockout A549 cells (A549 ΔTF ) were used to test whether lung epithelial TF is critical for the integrity of the alveolar epithelial barrier. TF +Epi mice were treated with intratracheal PBS or LPS and lung permeability was measured by bronchoalveolar lavage (BAL) fluid protein level. Alveolar type II epithelial cells (ATII) were isolated from TF ΔEpi and TF +Epi mice to measure β1 integrin protein levels. A549 ΔTF cells were treated with LPS (100ug/mL) or PBS for 24 hours before western blot of β1 integrin expression. Migration was assessed in wild‐type and A549 ΔTF cells using Electric Cell‐substrate Impedance Sensing (ECIS) on cell monolayers. Adhesion was assayed by plating wild‐type and A549 ΔTF cells on matrigel and quantifying the absorbance of crystal violet stained adherent cells. Results TF +Epi mice had decreased lung permeability (BAL protein 303 μg/mL +/− 62 versus 416 +/− 137 in control, p=0.025) following LPS challenge. A549 ΔTF cells had significantly decreased cell adhesion (Figure) (absorbance 0.308 +/− 0.119 versus 0.603 +/− 0.246 in wild type, *p<0.001) along with decreased migration (p=0.017) compared to control A549 cells with wild type TF expression levels. A549 ΔTF cells had decreased β1 integrin protein levels (relative expression 0.017 +/− 0.01 versus 0.61 +/− 0.02 control, p=0.036) following LPS challenge. ATII cells isolated from TF ΔEpi mice also have decreased β1 integrin protein levels. Conclusions TF contributes to alveolar barrier integrity in part through a mechanism dependent on β1 integrin. These data provide support that lung epithelial TF may play a non‐coagulative role in protection during ALI. This novel role for TF in maintaining alveolar epithelial barrier integrity offers a potential therapeutic target during ALI. Support or Funding Information Vanderbilt University Initiative for Maximizing Student Diversity funding through the NIH, Nashville Veterans Affairs Medical Center, Funding: HL090785, HL103836 This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .