Epigenetic down regulation of nerve growth factor during alcohol withdrawal.

We investigated the Cytosin-phosphatidyl-Guanin (CpG) island promoter methylation (mean and methylation of individual CpG-sites) of the nerve growth factor (NGF) gene in the blood of alcohol-dependent patients (57 male patients) during withdrawal (days 1, 7 and 14). Methylation and NGF serum levels did not change significantly from days 1-7. From days 7-14, mean methylation increased (F = 30.55, P < 0.001), whereas the NGF serum levels decreased significantly (days 7-14: F = 17.95, P < 0.001). The NGF serum levels were significantly associated with the mean methylation of the investigated CpG-sites (F = 1.55, P < 0.001). These results imply an epigenetic regulation of the NGF gene during alcohol withdrawal.