title: Indoleamine 2,3-dioxygenase 1 is upregulated in activated microglia in mice cerebellum during acute viral encephalitis.
abstract: Indoleamine 2,3-dioxygenase1 (IDO1) is the rate-limiting enzyme in the kynurenine pathway that converts l-tryptophan to l-kynurenine. Encephalomyocarditis virus (EMCV) can cause acute myocarditis in various animals including mice. Previously, IDO1 has been reported to have an important immunomodulatory function in immune-related diseases. However, the pathophysiological roles of IDO1 following acute viral infection of central nervous system are not fully understood. We observed that acute EMCV infection leads to a highly reproducible neuronal degeneration in mouse cerebellum. The goal of this study is to determine tissue/cell-specific and time-dependent expressions of IDO1 during acute EMCV infection in mouse cerebellum. IDO1 was up-regulated in microglia, which was recognized to be activated morphologically and positive for ionized calcium-binding adapter molecule 1 (Iba-1), a protein expressed in microglia, within EMCV-induced cerebellar lesions showing neuronal degeneration although the very weak expression of IDO1 is detected only in cytoplasm of Purkinje cells. No GFAP immunostaining was observed in EMCV-induced cerebellar lesions although many reactive astrocytes surrounding the lesions showed strongly positive immunostaining for GFAP 10 days after the viral inoculation. Thus, IDO1 expression may affect EMCV-induced neuronal degeneration in cerebellum.
authors: Department of Tumor Pathology, Gifu University Graduate School of Medicine, Gifu, Japan.
authors: Ayako
authors: A
authors: Taguchi
authors: Medical Science Division, United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, Gifu, Japan. Electronic address: mniwa@gifu-u.ac.jp.
authors: Masayuki
authors: M
authors: Niwa
authors: Faculty of Medical Science, Suzuka University of Medical Science, Mie, Japan.
authors: Masato
authors: M
authors: Hoshi
authors: Human Health Sciences, Kyoto University Graduate School of Medicine and Faculty of Medicine, Kyoto, Japan.
authors: Kuniaki
authors: K
authors: Saito
authors: Medical Science Division, United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, Gifu, Japan.
authors: Teruaki
authors: T
authors: Masutani
authors: Department of Tumor Pathology, Gifu University Graduate School of Medicine, Gifu, Japan.
authors: Kenji
authors: K
authors: Hisamatsu
authors: Department of Tumor Pathology, Gifu University Graduate School of Medicine, Gifu, Japan.
authors: Kazuhiro
authors: K
authors: Kobayashi
authors: Department of Tumor Pathology, Gifu University Graduate School of Medicine, Gifu, Japan.
authors: Yuichiro
authors: Y
authors: Hatano
authors: Department of Tumor Pathology, Gifu University Graduate School of Medicine, Gifu, Japan.
authors: Hiroyuki
authors: H
authors: Tomita
authors: Department of Tumor Pathology, Gifu University Graduate School of Medicine, Gifu, Japan.
authors: Akira
authors: A
authors: Hara
mesh_terms: D000818:Animals; D018188:Cardiovirus Infections / Q000378:metabolism* / Q000821:virology; D002531:Cerebellum / Q000201:enzymology*; D018792:Encephalitis, Viral / Q000201:enzymology* / Q000821:virology; D004686:Encephalomyocarditis virus / Q000378:metabolism; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D017628:Microglia / Q000201:enzymology*; D015854:Up-Regulation
chemical_list: C583637:IDO1 protein, mouse; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase
keywords: Cerebellum; Encephalomyocarditis virus; Indoleamine 2,3-dioxygenase; Microglia; Neuronal degeneration