title: Expression of CD36 by Olfactory Receptor Cells and Its Abundance on the Epithelial Surface in Mice.
abstract: CD36 is a transmembrane protein that is involved in the recognition of certain amphiphilic molecules such as polar lipids in various tissues and body fluids. So far, CD36 homologues in insects have been demonstrated to be present on the surface of olfactory dendrites and to participate in the perception of exogenous compounds. However, little is known about the relationship between CD36 and mammalian olfaction. Indeed, the detection of only CD36 mRNA in the mouse olfactory epithelium has been reported to date. In the present study, to provide potential pieces of evidence for the involvement of CD36 in mammalian olfactory perception, we extensively investigated the localisation of this protein in the mouse olfactory mucosa. In situ hybridisation analysis using antisense oligonucleotides to CD36 mRNA detected aggregated signals within the deeper epithelial layer of olfactory mucosa. The mRNA signals were also detected consistently in the superficial layer of the olfactory epithelium, which is occupied by supporting cells. Immunostaining with an anti-CD36 polyclonal antibody revealed that CD36 localises in the somata and dendrites of distinct olfactory receptor cells and that it occurs abundantly on the olfactory epithelial surface. However, immunoreactive CD36 was rarely detectable in the nerve bundles running in the lamina propria of olfactory mucosa, the axons forming the olfactory nerve layer in the outermost layer of the bulb and axon terminals in the glomeruli. We also obtained electron microscopic evidence for the association of CD36 protein with olfactory cilia. Altogether, we suggest that CD36 plays a role in the mammalian olfaction. In addition, signals for CD36 protein were also detected on or around the microvilli of olfactory supporting cells and the cilia of nasal respiratory epithelium, suggesting a role for this protein other than olfaction in the nasal cavity.
authors.affiliation: Laboratory of Nutrition Chemistry, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan.
authors.forename: Shinhye
authors.initials: S
authors.lastname: Lee
authors.affiliation: Laboratory of Nutrition Chemistry, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan.
authors.forename: Ai
authors.initials: A
authors.lastname: Eguchi
authors.affiliation: Laboratory of Nutrition Chemistry, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tsuzuki
authors.affiliation: Laboratory of Nutrition Chemistry, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan.
authors.forename: Shigenobu
authors.initials: S
authors.lastname: Matsumura
authors.affiliation: Laboratory of Nutrition Chemistry, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Inoue
authors.affiliation: Laboratory of Histology and Cytology, Graduate School of Medicine, Hokkaido University, Sapporo, Hokkaido, Japan.
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Iwanaga
authors.affiliation: Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
authors.forename: Daisaku
authors.initials: D
authors.lastname: Masuda
authors.affiliation: Department of Community Medicine, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
authors.forename: Shizuya
authors.initials: S
authors.lastname: Yamashita
authors.affiliation: Laboratory of Nutrition Chemistry, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan.
authors.forename: Tohru
authors.initials: T
authors.lastname: Fushiki
mesh_terms: D000818:Animals; D015153:Blotting, Western; D018955:CD36 Antigens / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D017403:In Situ Hybridization; D008810:Mice, Inbred C57BL; D009831:Olfactory Mucosa / Q000378:metabolism* / Q000648:ultrastructure; D018034:Olfactory Receptor Neurons / Q000378:metabolism* / Q000648:ultrastructure; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D018955:CD36 Antigens; D012333:RNA, Messenger