title: Elevated TREM2 mRNA expression in leukocytes in schizophrenia but not major depressive disorder.
abstract: The pathological mechanisms of schizophrenia (SCZ) have not been clarified, but the microglia hypothesis has recently been discussed. We previously reported that the mRNA for a protein related to activation of microglia, triggering receptor expressed on myeloid cell 2 (TREM2), is expressed higher in peripheral leukocytes in SCZ than controls. In this study, we analyzed TREM2 mRNA expression in leukocytes from both SCZ and major depressive disorder (MDD) patients. We compared 50 SCZ patients and 42 MDD patients with age-matched controls. Levels of TREM2 mRNA in leukocytes were analyzed with quantitative real-time PCR method using TaqMan probe. TREM2 mRNA expression was significantly higher in leukocytes of SCZ subjects than controls, but the expression level was non-significantly different in MDD subjects. We observed a decrease in TREM2 mRNA expression in leukocytes from one SCZ patient after clozapine treatment. The expression did not change following ECT, but the expression level in this patient was still significantly higher than that in controls. We conclude that the high amount of TREM2 mRNA expression in leukocytes is specific to SCZ but not MDD and that changes in TREM2 mRNA expression may be a trait biomarker for SCZ.
authors.affiliation: Department of Neuropsychiatry, Molecules and Function, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, 791-0295, Japan.
authors.forename: Yuta
authors.initials: Y
authors.lastname: Yoshino
authors.affiliation: Department of Neuropsychiatry, Molecules and Function, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, 791-0295, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Kawabe
authors.affiliation: Department of Neuropsychiatry, Molecules and Function, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, 791-0295, Japan.
authors.forename: Kiyohiro
authors.initials: K
authors.lastname: Yamazaki
authors.affiliation: Department of Psychiatry, Course of Integrated Brain Sciences, Medical Informatics, Institute of Health Biosciences, The University of Tokushima Graduate School, 3-8-15 Kuramoto-cho, Tokushima, 770-8503, Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Watanabe
authors.affiliation: Department of Psychiatry, Course of Integrated Brain Sciences, Medical Informatics, Institute of Health Biosciences, The University of Tokushima Graduate School, 3-8-15 Kuramoto-cho, Tokushima, 770-8503, Japan.
authors.forename: Shusuke
authors.initials: S
authors.lastname: Numata
authors.affiliation: Department of Neuropsychiatry, Molecules and Function, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, 791-0295, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Mori
authors.affiliation: Department of Neuropsychiatry, Molecules and Function, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, 791-0295, Japan.
authors.forename: Taku
authors.initials: T
authors.lastname: Yoshida
authors.affiliation: Department of Neuropsychiatry, Molecules and Function, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, 791-0295, Japan. igajunichi@hotmail.com.
authors.forename: Junichi
authors.initials: J
authors.lastname: Iga
authors.affiliation: Department of Psychiatry, Course of Integrated Brain Sciences, Medical Informatics, Institute of Health Biosciences, The University of Tokushima Graduate School, 3-8-15 Kuramoto-cho, Tokushima, 770-8503, Japan.
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Ohmori
authors.affiliation: Department of Neuropsychiatry, Molecules and Function, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, 791-0295, Japan.
authors.forename: Shu-Ichi
authors.initials: S
authors.lastname: Ueno
mesh_terms: D000368:Aged; D003865:Major Depressive Disorder / Q000097:blood*; D005260:Female; D006801:Humans; D007962:Leukocytes / Q000378:metabolism*; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism*; D008875:Middle Aged; D012333:RNA, Messenger / Q000378:metabolism; D011971:Receptors, Immunologic / Q000378:metabolism*; D012559:Schizophrenia / Q000097:blood*
chemical_list: D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D011971:Receptors, Immunologic; C498715:TREM2 protein, human
keywords: Major depressive disorder; Microglia cell; Neuroinflammation; Schizophrenia; TREM2