Development of diagnosis of intractable schizophrenia by the analysisof DNA methylation.

In this study, we focused DNA methylation as one of gene expression regulators. To analyze the DNA methylation variant, mice were treated with METH or saline for 6 days. Mice genomic DNA was extracted from NAc tissue and peripheral blood 2 h after the last injection. In METH treated mice, the methylation level of Shati/Nat8l promoter specific region prepared from NAc was lower than that of saline treated mice. Moreover, same domain of genome DNA extracted from cardiac blood in METH treated mice was less methylated compared with saline treated mice. These results indicate that expression of Shati/Nat8l might be regulated by DNA methylation, and to analyze the blood level of methylation at Shati/Nat8l specific genomic region could help a diagnosis of psychiatric disorders in clinical field.