title: The 2-pore domain potassium channel TREK-1 regulates stretch-induced detachment of alveolar epithelial cells.
abstract: Acute Respiratory Distress Syndrome remains challenging partially because the underlying mechanisms are poorly understood. While inflammation and loss of barrier function are associated with disease progression, our understanding of the biophysical mechanisms associated with ventilator-associated lung injury is incomplete. In this line of thinking, we recently showed that changes in the F-actin content and deformability of AECs lead to cell detachment with mechanical stretch. Elsewhere, we discovered that cytokine secretion and proliferation were regulated in part by the stretch-activated 2-pore domain K(+) (K2P) channel TREK-1 in alveolar epithelial cells (AECs). As such, the aim of the current study was to determine whether TREK-1 regulated the mechanobiology of AECs through cytoskeletal remodeling and cell detachment. Using a TREK-1-deficient human AEC line (A549), we examined the cytoskeleton by confocal microscopy and quantified differences in the F-actin content. We used nano-indentation with an atomic force microscope to measure the deformability of cells and detachment assays to quantify the level of injury in our monolayers. We found a decrease in F-actin and an increase in deformability in TREK-1 deficient cells compared to control cells. Although total vinculin and focal adhesion kinase (FAK) levels remained unchanged, focal adhesions appeared to be less prominent and phosphorylation of FAK at the Tyr(925) residue was greater in TREK-1 deficient cells. TREK-1 deficient cells have less F-actin and are more deformable making them more resistant to stretch-induced injury.
authors.affiliation: Department of Biomedical Engineering, University of Memphis, Memphis, Tennessee, United States of America.
authors.forename: Esra
authors.initials: E
authors.lastname: Roan
authors.affiliation: Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee, United States of America ; Department of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee, United States of America.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Waters
authors.affiliation: Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee, United States of America.
authors.forename: Bin
authors.initials: B
authors.lastname: Teng
authors.affiliation: Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee, United States of America.
authors.forename: Manik
authors.initials: M
authors.lastname: Ghosh
authors.affiliation: Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee, United States of America ; Department of Pediatrics, University of Tennessee Health Science Center, Memphis, Tennessee, United States of America ; Department of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee, United States of America.
authors.forename: Andreas
authors.initials: A
authors.lastname: Schwingshackl
mesh_terms: D000199:Actins / Q000378:metabolism; D001696:Biomechanical Phenomena; D002460:Cell Line; D003599:Cytoskeleton / Q000378:metabolism; D004847:Epithelial Cells / Q000502:physiology*; D006801:Humans; D018625:Microscopy, Atomic Force; D018613:Microscopy, Confocal; D024683:Potassium Channels, Tandem Pore Domain / Q000378:metabolism*; D011650:Pulmonary Alveoli / Q000166:cytology*; D012128:Respiratory Distress Syndrome / Q000503:physiopathology*
chemical_list: D000199:Actins; D024683:Potassium Channels, Tandem Pore Domain; C103742:potassium channel protein TREK-1