title: Alpha1-chimaerin, a Rac1 GTPase-activating protein, is expressed at reduced mRNA levels in the brain of Alzheimer's disease patients.
abstract: Alpha1-chimaerin is a GTPase-activating protein (GAP) for Rac1, a member of the Rho small GTPase family, whose action leads to the inactivation of Rac1. Rac1 activity is upregulated in Alzheimer's disease, but little is known about the role of α1-chimaerin. In this study, we investigated the expression and localization of α1-chimaerin mRNA in postmortem human brains from patients with Alzheimer's disease and control subjects. In situ hybridization studies demonstrated that α1-chimaerin was expressed by neurons in the neo-cortex of the temporal lobe and the hippocampus of both controls and Alzheimer's disease cases, with the signal intensity dramatically decreased in patients with Alzheimer's disease. Real-time PCR analysis confirmed a significant reduction of α1-chimaerin mRNA expression in the temporal cortex of Alzheimer's disease cases. In contrast, α2-chimaerin mRNA levels showed no significant difference between the groups. The present study showed reduced α1-chimaerin expression in the brain of Alzheimer's disease cases, suggesting a role in the upregulation of Rac1 activity during the disease process.
authors: Molecular Neuroscience Research Center, Shiga University of Medical Science, Otsu 520-2192, Japan.
authors: Tomoko
authors: T
authors: Kato
authors: Department of Clinical Research, Nishi-tottori National Hospital, Tottori 689-0202, Japan.
authors: Yoshihiro
authors: Y
authors: Konishi
authors: Department of Neurology, Sapporo Medical University, Sapporo 060-8556, Japan.
authors: Shun
authors: S
authors: Shimohama
authors: Banner Sun Health Research Institute, Sun City, AZ 85372, USA.
authors: Thomas G
authors: TG
authors: Beach
authors: Department of Community-Based Medical Education, Nagoya City University Graduate School of Medical Sciences, Nagoya 467-8601, Japan.
authors: Hiroyasu
authors: H
authors: Akatsu
authors: Molecular Neuroscience Research Center, Shiga University of Medical Science, Otsu 520-2192, Japan. Electronic address: kinchan@belle.shiga-med.ac.jp.
authors: Ikuo
authors: I
authors: Tooyama
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000378:metabolism*; D001921:Brain / Q000378:metabolism*; D016022:Case-Control Studies; D020848:Chimerin 1 / Q000235:genetics / Q000378:metabolism*; D005260:Female; D006624:Hippocampus / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D017966:Pyramidal Cells / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D013702:Temporal Lobe / Q000378:metabolism
chemical_list: D020848:Chimerin 1; D012333:RNA, Messenger
keywords: Alzheimer’s disease; In situ hybridization; Rac1; Real-time PCR; α1-chimaerin