title: Mitral and tufted cells are potential cellular targets of nitration in the olfactory bulb of aged mice.
abstract: Olfactory sensory function declines with age; though, the underlying molecular changes that occur in the olfactory bulb (OB) are relatively unknown. An important cellular signaling molecule involved in the processing, modulation, and formation of olfactory memories is nitric oxide (NO). However, excess NO can result in the production of peroxynitrite to cause oxidative and nitrosative stress. In this study, we assessed whether changes in the expression of 3-nitrotyrosine (3-NT), a neurochemical marker of peroxynitrite and thus oxidative damage, exists in the OB of young, adult, middle-aged, and aged mice. Our results demonstrate that OB 3-NT levels increase with age in normal C57BL/6 mice. Moreover, in aged mice, 3-NT immunoreactivity was found in some blood vessels and microglia throughout the OB. Notably, large and strongly immunoreactive puncta were found in mitral and tufted cells, and these were identified as lipofuscin granules. Additionally, we found many small-labeled puncta within the glomeruli of the glomerular layer and in the external plexiform layer, and these were localized to mitochondria and discrete segments of mitral and tufted dendritic plasma membranes. These results suggest that mitral and tufted cells are potential cellular targets of nitration, along with microglia and blood vessels, in the OB during aging.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, College of Medicine, The Catholic University of Korea, St Vincent's Hospital, Suwon, Gyeonggi-do, Korea.
authors.forename: Myung Jae
authors.initials: MJ
authors.lastname: Yang
authors.forename: Sooyeon
authors.initials: S
authors.lastname: Sim
authors.forename: Ji Hyun
authors.initials: JH
authors.lastname: Jeon
authors.forename: Eojin
authors.initials: E
authors.lastname: Jeong
authors.forename: Hyoung-Chin
authors.initials: HC
authors.lastname: Kim
authors.forename: Yong-Jin
authors.initials: YJ
authors.lastname: Park
authors.forename: In-Beom
authors.initials: IB
authors.lastname: Kim
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D015415:Biomarkers / Q000378:metabolism*; D015153:Blotting, Western; D007150:Immunohistochemistry; D008568:Memory / Q000502:physiology*; D051379:Mice; D008854:Microscopy, Electron; D009569:Nitric Oxide / Q000378:metabolism; D009830:Olfactory Bulb / Q000166:cytology / Q000502:physiology* / Q000648:ultrastructure; D018384:Oxidative Stress / Q000502:physiology*; D012903:Smell / Q000502:physiology*; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism
chemical_list: D015415:Biomarkers; D009569:Nitric Oxide; C002744:3-nitrotyrosine; D014443:Tyrosine