title: Alpha-synuclein immunoreactivity in normal and neoplastic Schwann cells.
abstract: Alpha-synuclein is known to play an important role in several neurodegenerative diseases. Moreover, it is expressed in central nervous system neuronal tumors, and another member of the synuclein family, gamma-synuclein, is overexpressed in breast and ovarian carcinomas. However, the expression of alpha-synuclein has not been reported hitherto in the peripheral nervous system (PNS). In the present study, we investigated normal PNS tissue and schwannomas in human postmortem and biopsy samples using both immunocytochemistry and immunoelectron microscopy with antibodies against alpha-, beta- and gamma-synuclein. In normal PNS tissue, Schwann cells, but not axons or myelin, were immunopositive for alpha-synuclein. In schwannomas, almost all of the tumor cells showed diffuse cytoplasmic staining for alpha-synuclein (30 cases). Ultrastructurally, alpha-synuclein immunoreactivity was found in the cytoplasm of normal and neoplastic Schwann cells, in association with the plasma membrane, ribosomes, rough endoplasmic reticulum, small vesicles, Golgi apparatus and the nuclear outer membrane. No beta- or gamma-synuclein immunoreactivity was found in those cells. These results indicate that in the PNS, alpha-synuclein is a useful marker of Schwann cells and that it is not involved in tumorigenesis.
authors.affiliation: Department of Neuropathology, Institute of Brain Science, Hirosaki University School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562, Japan. neuropal@cc.hirosaki-u.ac.jp
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Mori
authors.forename: Chikanori
authors.initials: C
authors.lastname: Inenaga
authors.forename: Makoto
authors.initials: M
authors.lastname: Yoshimoto
authors.forename: Hajime
authors.initials: H
authors.lastname: Umezu
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Tanaka
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Takahashi
authors.forename: Koichi
authors.initials: K
authors.lastname: Wakabayashi
mesh_terms: D000368:Aged; D000818:Animals; D006801:Humans; D016253:Microscopy, Immunoelectron; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000276:immunology* / Q000648:ultrastructure; D009442:Neurilemmoma / Q000276:immunology* / Q000473:pathology* / Q000648:ultrastructure; D010524:Peripheral Nervous System Neoplasms / Q000276:immunology* / Q000473:pathology* / Q000648:ultrastructure; D051381:Rats; D017208:Rats, Wistar; D012016:Reference Values; D012583:Schwann Cells / Q000276:immunology* / Q000473:pathology* / Q000648:ultrastructure; D051843:Synucleins; D051844:alpha-Synuclein; D051845:gamma-Synuclein
chemical_list: D009419:Nerve Tissue Proteins; C497604:SNCA protein, human; C497606:Snca protein, rat; D051843:Synucleins; D051844:alpha-Synuclein; D051845:gamma-Synuclein