title: The effect of fluoride on the structure, function, and proteome of a renal epithelial cell monolayer.
abstract: High concentrations of fluoride in the body may cause toxic effects. Here, we investigated the effects of fluoride on the structure, function, and proteome of a cortical collecting duct epithelium in vitro. Kidney tubule cells (M-1) were chosen because the concentration of fluoride in the kidney is 4-5-fold higher than that in plasma. Mouse M-1 cell monolayers were incubated in fluoride-containing media, and the amiloride-sensitive short-circuit current and transepithelial resistance were measured. The Young's modulus of the epithelium was determined using atomic force microscopy, and the effect of fluoride on epithelial structure was assessed using scanning and transmission electron microscopy, and immunofluorescence. Differences in the expression of membrane proteins were evaluated using proteomics and bioinformatics. Fluoride exposure reduced both transepithelial Na+transport and resistance. The IC50for fluoride was ∼300 µM for both effects, and the half-times for the decays of ion transport and resistance were 8.4 h and 3.6 days, respectively. Fluoride treatment did not affect the sensitivity of Na+transport to amiloride. The Young's modulus of the epithelium was also unaffected by fluoride; however, the functional effects of fluoride were accompanied by marked structural effects. Proteomic analysis revealed changes in expression of a number of proteins, and particularly mitochondrial proteins. Treatment with fluoride had profound effects on the structure, function and proteome of a model cortical collecting duct epithelium. Significantly, however, these effects were produced only at concentrations considerably higher than those likely to be encountered in vivo. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1455-1467, 2017.
authors.affiliation: Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Ligia S
authors.initials: LS
authors.lastname: Antonio
authors.affiliation: Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Pia
authors.initials: P
authors.lastname: Jeggle
authors.affiliation: Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Lesley J
authors.initials: LJ
authors.lastname: MacVinish
authors.affiliation: Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom.
authors.forename: James C
authors.initials: JC
authors.lastname: Bartram
authors.affiliation: Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Henry
authors.initials: H
authors.lastname: Miller
authors.affiliation: Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Gavin E
authors.initials: GE
authors.lastname: Jarvis
authors.affiliation: Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil.
authors.forename: Flávia M
authors.initials: FM
authors.lastname: Levy
authors.affiliation: Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil.
authors.forename: Mariana R
authors.initials: MR
authors.lastname: Santesso
authors.affiliation: Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil.
authors.forename: Aline L
authors.initials: AL
authors.lastname: Leite
authors.affiliation: Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil.
authors.forename: Rodrigo C
authors.initials: RC
authors.lastname: Oliveira
authors.affiliation: Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil.
authors.forename: Marília A R
authors.initials: MA
authors.lastname: Buzalaf
authors.affiliation: Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom.
authors.forename: J Michael
authors.initials: JM
authors.lastname: Edwardson
mesh_terms: D000818:Animals; D002327:Cariostatic Agents / Q000633:toxicity*; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism*; D017136:Ion Transport / Q000187:drug effects; D007684:Kidney Tubules / Q000166:cytology; D008564:Membrane Potentials; D051379:Mice; D060066:Protein Interaction Maps; D020543:Proteome / Q000378:metabolism*; D040901:Proteomics; D012969:Sodium Fluoride / Q000633:toxicity*
chemical_list: D002327:Cariostatic Agents; D020543:Proteome; D012969:Sodium Fluoride
keywords: atomic force microscopy; cell stiffness; epithelial ion transport; fluoride; kidney; proteomics