DNA methylation analysis of BDNF gene promoters in peripheral blood cells of schizophrenia patients

Accumulating evidence suggests that epigenetic alterations in brain-derived neurotrophic factor (BDNF) promoters are associated with the pathophysiology of psychiatric disorders. Epigenetic changes in BDNF were reported not only in brain tissues but also in other tissues, including peripheral blood cells (PBC) and saliva. We examined DNA methylation levels ofBDNF promoters land IV using genomic DNA derived from PBC of healthy controls (n = 100), and patients with schizophrenia (n = 100), all from the Japanese population, by pyrosequencing. The examined CpG sites were chosen based on previous epigenetic studies that reported altered DNA methylation. We found a significantly higher level of methylation at BDNFpromoter I in patients with schizophrenia compared to controls, although the difference was small. Subsequent analysis revealed that in controls, the methylation level of BDNF promoters was associated with sex, and the methylation difference observed in promoter I was more prominent in male patients with schizophrenia. Epigenetic alteration ofBDNF in the PBC might reflect the pathophysiology of schizophrenia, and could be a potential biomarker. (c) 2013 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.