title: Heat stress causes spatially-distinct membrane re-modelling in K562 leukemia cells.
abstract: Cellular membranes respond rapidly to various environmental perturbations. Previously we showed that modulations in membrane fluidity achieved by heat stress (HS) resulted in pronounced membrane organization alterations which could be intimately linked to the expression and cellular distribution of heat shock proteins. Here we examine heat-induced membrane changes using several visualisation methods. With Laurdan two-photon microscopy we demonstrate that, in contrast to the enhanced formation of ordered domains in surface membranes, the molecular disorder is significantly elevated within the internal membranes of cells preexposed to mild HS. These results were compared with those obtained by anisotropy, fluorescence lifetime and electron paramagnetic resonance measurements. All probes detected membrane changes upon HS. However, the structurally different probes revealed substantially distinct alterations in membrane heterogeneity. These data call attention to the careful interpretation of results obtained with only a single label. Subtle changes in membrane microstructure in the decision-making of thermal cell killing could have potential application in cancer therapy.
authors.affiliation: Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary.
authors.forename: Gábor
authors.initials: G
authors.lastname: Balogh
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Maulucci
authors.forename: Imre
authors.initials: I
authors.lastname: Gombos
authors.forename: Ibolya
authors.initials: I
authors.lastname: Horváth
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Török
authors.forename: Mária
authors.initials: M
authors.lastname: Péter
authors.forename: Elfrieda
authors.initials: E
authors.lastname: Fodor
authors.forename: Tibor
authors.initials: T
authors.lastname: Páli
authors.forename: Sándor
authors.initials: S
authors.lastname: Benko
authors.forename: Tiziana
authors.initials: T
authors.lastname: Parasassi
authors.forename: Marco
authors.initials: M
authors.lastname: De Spirito
authors.forename: John L
authors.initials: JL
authors.lastname: Harwood
authors.forename: László
authors.initials: L
authors.lastname: Vígh
mesh_terms: D002462:Cell Membrane / Q000378:metabolism; D004578:Electron Spin Resonance Spectroscopy; D005456:Fluorescent Dyes; D006360:Heat-Shock Proteins / Q000378:metabolism; D006358:Hot Temperature; D006801:Humans; D020014:K562 Cells
chemical_list: D005456:Fluorescent Dyes; D006360:Heat-Shock Proteins