title: Lipopolysaccharide changes the subcellular distribution of aquaporin 5 and increases plasma membrane water permeability in mouse lung epithelial cells.
abstract: Aquaporin-5 (AQP5), a major water channel in lung epithelial cells, plays an important role in maintaining water homeostasis in the lungs. Cell surface expression of AQP5 is regulated by not only mRNA and protein synthesis but also changes in subcellular distribution. We investigated the effect of lipopolysaccharide (LPS) on the subcellular distribution of AQP5 in a mouse lung epithelial cell line (MLE-12). LPS caused significant increases in AQP5 in the plasma membrane at 0.5-2 h. Immunofluorescence and Western blotting strongly suggested that LPS altered AQP5 subcellular distribution from an intracellular vesicular compartment to the plasma membrane. The specific p38 MAP kinase inhibitor SB 203580 apparently prevented LPS-induced changes in AQP5 distribution. Furthermore, LPS increased the osmotic water permeability of MLE-12 cells. These findings demonstrate that LPS increases cell surface AQP5 expression by changing its subcellular distribution and increases membrane osmotic water permeability through activation of p38 MAP kinase.
authors.affiliation: Department of Chemico-Pharmacological Sciences, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Kumamoto 862-0973, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Ohinata
authors.forename: Kazufumi
authors.initials: K
authors.lastname: Nagai
authors.forename: Johji
authors.initials: J
authors.lastname: Nomura
authors.forename: Kodai
authors.initials: K
authors.lastname: Hashimoto
authors.forename: Akinori
authors.initials: A
authors.lastname: Hisatsune
authors.forename: Takeshi
authors.initials: T
authors.lastname: Miyata
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Isohama
mesh_terms: D000818:Animals; D051402:Aquaporin 5; D020346:Aquaporins / Q000378:metabolism*; D002462:Cell Membrane / Q000187:drug effects*; D002463:Cell Membrane Permeability / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004848:Epithelium / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008168:Lung / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D018613:Microscopy, Confocal; D014867:Water / Q000378:metabolism*
chemical_list: C496038:Aqp5 protein, mouse; D051402:Aquaporin 5; D020346:Aquaporins; D008070:Lipopolysaccharides; D008565:Membrane Proteins; D014867:Water