Promoter Methylation and <b><i>BDNF</i></b> and <b><i>DAT1</i></b> Gene Expression Profiles in Patients with Drug Addiction

Abstract

<b><i>Background:</i></b> Drug addiction is a brain disorder that has negative consequences for individuals and society. Addictions are chronic relapsing diseases of the brain that are caused by direct drug-induced effects and persevering neuroadaptations at the epigenetic, neuropeptide and neurotransmitter levels. Because the dopaminergic system has a significant role in drug abuse, the purpose of this study was to analyze the methylation and expression profile of brain-derived neurotrophic factor <i>(BDNF)</i> and dopamine transporter <i>(DAT1)</i> genes in individuals with drug addiction. <b><i>Materials and Methods:</i></b><i>BDNF</i> and <i>DAT1</i> promoter methylation were investigated with a methylation-specific polymerase chain reaction (PCR) technique in blood samples from 75 individuals with drug addiction and 65 healthy controls. The expression levels of <i>BDNF</i> and <i>DAT1</i> were assessed in 12 mRNA samples from the blood of patients and compared to the samples of healthy controls (n = 12) with real-time quantitative reverse transcription PCR. <b><i>Results:</i></b> No significant differences were found in the methylation of <i>BDNF</i> and <i>DAT1</i> between patients and controls, but the relative levels of expression of<i> BDNF </i>and <i>DAT1</i> mRNA differed significantly in the patients compared to controls (p < 0.0001). <b><i>Conclusion:</i></b> These results showed that the methylation status of the <i>BDNF </i>and<i> DAT1</i> genes had no significant function in the processes of drug addiction.