Gene expression profiling in the hippocampus of adolescent rats after chronic alcohol administration

In South Korea, the average age of onset of alcohol drinking is 13.3 years and half of adolescents drink alcohol more than once a month; 8.45% of the Korean adolescent population become future high-risk alcohol drinkers. Chronic alcohol abuse causes physical and psychiatric health problems such as alcohol addiction, liver disease, stroke and cognitive impairments. This study aimed to investigate the effect of alcohol on gene expression and their function in the hippocampus of adolescent rats. After chronic alcohol administration in male (control, n = 6; alcohol, n = 6) Sprague-Dawley rats for 6 weeks, we analysed up- or down-regulated genes using RNA-sequencing technology. We found 83 genes more than 1.5-fold up- or down-regulated in the alcohol-treated group. Among them, genes (Dnai1, Cfap206 and Dnah1) associated with cilium movement were up-regulated in the alcohol-treated group. Mlf1, related to cell cycle arrest, was also up-regulated in the alcohol-treated group. On the other hand, genes (Smad3 and Plk5) involved in negative regulation of cell proliferation were down-regulated in the hippocampus by chronic alcohol administration. In addition, expression levels of genes associated with oxidative stress (Krt8 and Car3) and migration (Vim) were changed by chronic alcohol administration. These results pave a path for a better understanding of the neuromolecular mechanisms mediated by chronic alcohol exposure in the hippocampus of adolescents and negative pathology due to chronic alcohol abuse.