title: Tracing of labile zinc in live fish hepatocytes using FluoZin-3.
abstract: Intracellular zinc levels are homeostatically regulated and although most is bound, a pool of labile Zn(II) is present in cells. We show here that the zinc probe FluoZin-3 is useful to monitor zinc fluxes during fluorescent imaging of the trout hepatic cell line D11. Nuclei and bulk cytosol appeared to lack detectable labile zinc, while the punctuate staining pattern colocalized with a lysosome-specific probe. Applying extracellular zinc alone resulted in vesicular sequestration of the metal ion. Together with Na-pyrithione a delayed and toxic rise in cellular fluorescence was triggered. When using another ionophore, 4-Br A23187, a zinc buffering effect of the vesicular pools was evident. Secondly, N-ethylmaleimide induced a homogeneous fluorescence rise, which was strongly enhanced by addition of Zn-pyrithione and disappeared after TPEN washing. This suggests the involvement of thiol residues in controlling available cytosolic zinc. Our observations have implications for the interpretation of calculated intracellular Zn2+ concentrations.
authors.affiliation: Department of Biology, University of Antwerp, Groenenborgerlaan 171, B-2020, Antwerp, Belgium. frederik.muylle@diabetes-vdv.be
authors.forename: Frederik A R
authors.initials: FA
authors.lastname: Muylle
authors.forename: Dirk
authors.initials: D
authors.lastname: Adriaensen
authors.forename: Wim
authors.initials: W
authors.lastname: De Coen
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Timmermans
authors.forename: Ronny
authors.initials: R
authors.lastname: Blust
mesh_terms: D000818:Animals; D000001:Calcimycin / Q000031:analogs & derivatives / Q000494:pharmacology; D002478:Cells, Cultured; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism; D005399:Fishes / Q000378:metabolism*; D022781:Hepatocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D008247:Lysosomes / Q000378:metabolism; D018613:Microscopy, Confocal; D015394:Molecular Structure; D011083:Polycyclic Compounds / Q000737:chemistry / Q000493:pharmacokinetics*; D013997:Time Factors; D015032:Zinc / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology
chemical_list: C451182:FluoZin-3; D011083:Polycyclic Compounds; D000001:Calcimycin; C033170:4-bromo-A-23187; D015032:Zinc