title: Phosphatidyl-inositide signalling proteins in a novel class of sensory cells in the mammalian olfactory epithelium.
abstract: Ciliated sensory neurons, supporting cells and basal stem cells represent major cellular components of the main olfactory epithelium in mammals. Here we describe a novel class of sensory cells in the olfactory neuroepithelium. The cells express phospholipase C beta-2 (PLC beta2), transient receptor potential channels 6 (TRPC6) and inositol 3, 4, 5-trisphosphate receptors type III (InsP3R-III). Unlike ciliated olfactory neurons, they express neither olfactory marker protein nor centrin, adenylyl cyclase or cyclic nucleotide-gated cation channels. Typical components of the cytoskeleton of microvilli, ezrin and actin are found co-localized with PLC beta2 and TRPC6 in apical protrusions of the cells. In Ca2+-imaging experiments, the cells responded to odours. They express neuronal marker proteins and possess an axon-like process, but following bulbectomy the cells do not degenerate. Our results suggest a novel class of microvillous secondary chemosensory cells in the mammalian olfactory system. These cells, which utilize phosphatidyl-inositides in signal transduction, represent about 5% of all olfactory cells. Their abundance indicates that they play an important role in stimulus-dependent functions and/or the regeneration of the olfactory system.
authors.affiliation: Institute of General Zoology and Animal Physiology, Friedrich-Schiller-University, D-07743 Jena, Germany. selsaes3@jhem.jhmi.edu
authors.forename: Rebecca
authors.initials: R
authors.lastname: Elsaesser
authors.forename: Giorgia
authors.initials: G
authors.lastname: Montani
authors.forename: Roberto
authors.initials: R
authors.lastname: Tirindelli
authors.forename: Jacques
authors.initials: J
authors.lastname: Paysan
mesh_terms: D000818:Animals; D001483:Base Sequence; D015220:Calcium Channels / Q000235:genetics* / Q000502:physiology; D017931:DNA Primers; D004847:Epithelial Cells / Q000502:physiology; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000032:analysis / Q000235:genetics; D007150:Immunohistochemistry; D053496:Inositol 1,4,5-Trisphosphate Receptors; D007527:Isoenzymes / Q000235:genetics*; D051379:Mice; D008822:Mice, Transgenic; D008871:Microvilli / Q000201:enzymology / Q000502:physiology; D009475:Neurons, Afferent / Q000502:physiology; D009830:Olfactory Bulb / Q000502:physiology*; D009831:Olfactory Mucosa / Q000166:cytology / Q000187:drug effects / Q000201:enzymology / Q000502:physiology*; D010716:Phosphatidylinositols / Q000494:pharmacology*; D054799:Phospholipase C beta; D016133:Polymerase Chain Reaction; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000502:physiology; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D050052:TRPC Cation Channels; D000074287:TRPC6 Cation Channel; D010738:Type C Phospholipases / Q000235:genetics*
chemical_list: D015220:Calcium Channels; D017931:DNA Primers; D053496:Inositol 1,4,5-Trisphosphate Receptors; D007527:Isoenzymes; D010716:Phosphatidylinositols; D018160:Receptors, Cytoplasmic and Nuclear; D050052:TRPC Cation Channels; D000074287:TRPC6 Cation Channel; C492146:Trpc6 protein, mouse; D049452:Green Fluorescent Proteins; D010738:Type C Phospholipases; D054799:Phospholipase C beta; C518037:Plcb2 protein, mouse