TITLE:
DNA methylation of the Monoamine Oxidases A and B genes in postmortem brains of subjects with schizophrenia
AUTHORS:
Qiaohui Yang, Keiko Ikemoto, Satoshi Nishino, Junko Yamaki, Yasuto Kunii, Akira Wada, Yoshimi Homma, Shin-Ichi Niwa
KEYWORDS:
DNA Methylation; Monoamine Oxidase; Nucleus Accumbens; Postmortem Brain; Schizophrenia
JOURNAL NAME:
Open Journal of Psychiatry,
Vol.2 No.4,
November
27,
2012
ABSTRACT: Aims: We focused on DNA methylation of the promoter regions of the Monoamine Oxidase (MAO) A and B genes from postmortem brains of subjects with schizophrenia. Methods: We determined levels of DNA methylation using genomic DNA samples purified from four brain areas: prefrontal cortex (PFC), hippocampus, occipital cortex and nucleus accumbens (NAc), by a bisulfite sequencing method from seven normal subjects and six subjects with schizophrenia. Results: Although very few methylated CpGs of the MAOA and MAOB genes were detected in male samples, various DNA methylation patterns were present in female samples, and some differences were found in such patterns between normal subjects and subjects with schizophrenia. In the PFC, the average level of methylation of both genes was significantly higher in subjects with schizophrenia than in normal subjects. The content of highly methylated alleles of the MAOA gene in the NAc was significantly associated with schizophrenia, with similar results obtained for the MAOB gene in both the NAc and PFC. Some CpG sites showed higher levels of methylation in schizophrenia than in normal subjects. Conclusions: Levels of methylation were quite high in NAc and PFC in female subjects with schizophrenia compared with those in female normal subjects.