Brain-derived neurotrophic factor (BDNF) is involved in the pathophysiology of psychiatric disorders in adults and elderly individuals, and as a result, the DNA methylation (DNAm) of the BDNF gene in peripheral tissues including blood has been extensively examined to develop a useful biomarker for psychiatric disorders. However, studies to date have not previously investigated the effect of age on DNAm of the BDNF gene in blood. In this context, the authors measured DNAm of 39 CpG units in the CpG island at the promoter of exon I of the BDNF gene. Genomic DNA from peripheral blood of 105 health Japanese women 20 to 80 years of age was analysed to identify aging-associated change in DNAm of the BDNF gene. In addition, the relationship between total MMSE scores, numbers of stressful life events, and serum BDNF levels on DNAm of the BDNF gene were evaluated. The DNAm rate at each CpG unit was measured using a MassArray® system (Agena Bioscience), and serum BDNF levels were measured by ELISA. There was a significant correlation between DNAm and age in 13 CpGs. However, there was no significant correlation between DNAm and total MMSE scores, numbers of life events, or serum BDNF levels. Despite the small number of subjects and the inclusion of only female subjects, the authors concluded that the results suggest that DNAm of 13 CpGs of the BDNF gene may be an appropriate biomarker for aging and useful for predicting increased susceptibility to age-related psychiatric disorders.
Authors: Ihara K, Fuchikami M, Hashizume M, Okada S, Kawai H, Obuchi S, Hirano H, Fujiwara Y, Hachisu M, Hongyong K, Morinobu S. ; Full Source: International Journal of Geriatric Psychiatry. 2018 Jun 28. doi: 10.1002/gps.4927. [Epub ahead of print]