title: Proteomic analysis of lymphoblastoid cells derived from monozygotic twins discordant for bipolar disorder: a preliminary study.
abstract: Bipolar disorder is a severe mental illness characterized by recurrent manic and depressive episodes. In bipolar disorder, family and twin studies suggest contributions from genetic and environmental factors; however, the detailed molecular pathogenesis is yet unknown. Thus, identification of biomarkers may contribute to the clinical diagnosis of bipolar disorder. Monozygotic twins discordant for bipolar disorder are relatively rare but have been reported. Here we performed a comparative proteomic analysis of whole cell lysate derived from lymphoblastoid cells of monozygotic twins discordant for bipolar disorder by using two-dimensional differential in-gel electrophoresis (2D-DIGE). We found approximately 200 protein spots to be significantly differentially expressed between the patient and the co-twin (t test, p<0.05). Some of the proteins were subsequently identified by liquid chromatography tandem mass spectrometry and included proteins involved in cell death and glycolysis. To examine whether these proteins could serve as biomarkers of bipolar disorder, we performed Western blot analysis using case-control samples. Expression of phosphoglycerate mutase 1 (PGAM1), which is involved in glycolysis, was significantly up-regulated in patients with bipolar disorder (t test, p<0.05). Although PGAM1 cannot be regarded as a qualified biomarker of bipolar disorder from this preliminary finding, it could be one of the candidates for further study to identify biomarkers of bipolar disorder.
authors: Laboratory for Molecular Dynamics of Mental Disorders, Brain Science Institute, RIKEN, Saitama, Japan.
authors: An-a
authors: AA
authors: Kazuno
authors: Kenji
authors: K
authors: Ohtawa
authors: Kaori
authors: K
authors: Otsuki
authors: Masaya
authors: M
authors: Usui
authors: Hiroko
authors: H
authors: Sugawara
authors: Yuji
authors: Y
authors: Okazaki
authors: Tadafumi
authors: T
authors: Kato
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000378:metabolism; D001714:Bipolar Disorder / Q000175:diagnosis* / Q000235:genetics; D015153:Blotting, Western; D016022:Case-Control Studies; D002853:Chromatography, Liquid; D030562:Databases, Protein; D015180:Electrophoresis, Gel, Two-Dimensional; D005260:Female; D006801:Humans; D008214:Lymphocytes / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D040901:Proteomics; D053719:Tandem Mass Spectrometry; D014430:Twins, Monozygotic
chemical_list: D015415:Biomarkers