title: Bright and photostable push-pull pyrene dye visualizes lipid order variation between plasma and intracellular membranes.
abstract: Imaging lipid organization in cell membranes requires advanced fluorescent probes. Here, we show that a recently synthesized push-pull pyrene (PA), similarly to popular probe Laurdan, changes the emission maximum as a function of lipid order, but outperforms it by spectroscopic properties. In addition to red-shifted absorption compatible with common 405 nm diode laser, PA shows higher brightness and much higher photostability than Laurdan in apolar membrane environments. Moreover, PA is compatible with two-photon excitation at wavelengths >800 nm, which was successfully used for ratiometric imaging of coexisting liquid ordered and disordered phases in giant unilamellar vesicles. Fluorescence confocal microscopy in Hela cells revealed that PA efficiently stains the plasma membrane and the intracellular membranes at >20-fold lower concentrations, as compared to Laurdan. Finally, ratiometric imaging using PA reveals variation of lipid order within different cellular compartments: plasma membranes are close to liquid ordered phase of model membranes composed of sphingomyelin and cholesterol, while intracellular membranes are much less ordered, matching well membranes composed of unsaturated phospholipids without cholesterol. These differences in the lipid order were confirmed by fluorescence lifetime imaging (FLIM) at the blue edge of PA emission band. PA probe constitutes thus a new powerful tool for biomembrane research.
authors.affiliation: Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de Pharmacie, 74, Route du Rhin, 67401 ILLKIRCH Cedex, France.|Department of Organic and Polymeric Materials, Tokyo Institute of Technology, 2-12-1-H-134 O-okayama, Meguro-ku, Tokyo 152-8552, Japan.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Niko
authors.affiliation: Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de Pharmacie, 74, Route du Rhin, 67401 ILLKIRCH Cedex, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Didier
authors.affiliation: Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de Pharmacie, 74, Route du Rhin, 67401 ILLKIRCH Cedex, France.
authors.forename: Yves
authors.initials: Y
authors.lastname: Mely
authors.affiliation: Department of Organic and Polymeric Materials, Tokyo Institute of Technology, 2-12-1-H-134 O-okayama, Meguro-ku, Tokyo 152-8552, Japan.
authors.forename: Gen-ichi
authors.initials: G
authors.lastname: Konishi
authors.affiliation: Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de Pharmacie, 74, Route du Rhin, 67401 ILLKIRCH Cedex, France.
authors.forename: Andrey S
authors.initials: AS
authors.lastname: Klymchenko
mesh_terms: D015081:2-Naphthylamine / Q000031:analogs & derivatives / Q000737:chemistry; D002462:Cell Membrane / Q000378:metabolism* / Q000648:ultrastructure; D002784:Cholesterol / Q000737:chemistry / Q000378:metabolism; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry*; D006367:HeLa Cells; D006801:Humans; D007425:Intracellular Membranes / Q000378:metabolism* / Q000648:ultrastructure; D007848:Laurates / Q000737:chemistry; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D010713:Phosphatidylcholines / Q000737:chemistry / Q000378:metabolism; D011721:Pyrenes / Q000138:chemical synthesis / Q000737:chemistry*; D012680:Sensitivity and Specificity; D013109:Sphingomyelins / Q000737:chemistry / Q000378:metabolism; D053835:Unilamellar Liposomes / Q000737:chemistry* / Q000378:metabolism
chemical_list: D005456:Fluorescent Dyes; D007848:Laurates; D010713:Phosphatidylcholines; D011721:Pyrenes; D013109:Sphingomyelins; D053835:Unilamellar Liposomes; D002784:Cholesterol; D015081:2-Naphthylamine; C017251:1,2-oleoylphosphatidylcholine; C065580:laurdan