Binge ethanol exposure increases the Krüppel-like factor 11-monoamine oxidase (MAO) pathway in rats: Examining the use of MAO inhibitors to prevent ethanol-induced brain injury

Abstract

Binge drinking induces several neurotoxic consequences including oxidative stress and neurodegeneration. Because of these effects, drugs which prevent ethanol-induced damage to the brain may be clinically beneficial. In this study, we investigated the ethanol-mediated KLF11-MAO cell death cascade in the frontal cortex of Sprague-Dawley rats exposed to a modified Majchowicz 4-day binge ethanol model and control rats. Moreover, MAO inhibitors (MAOIs) were investigated for neuroprotective activity against binge ethanol. Binge ethanol-treated rats demonstrated a significant increase in KLF11, both MAO isoforms, protein oxidation and caspase-3, as well as a reduction in BDNF expression in the frontal cortex compared to control rats. MAOIs prevented these binge ethanol-induced changes, suggesting a neuroprotective benefit. Neither binge ethanol nor MAOI treatment significantly affected protein expression levels of the oxidative stress enzymes, SOD2 or catalase. Furthermore, ethanol-induced antinociception was enhanced following exposure to the 4-day ethanol binge. These results demonstrate that the KLF11-MAO pathway is activated by binge ethanol exposure and MAOIs are neuroprotective by preventing the binge ethanol-induced changes associated with this cell death cascade. This study supports KLF11-MAO as a mechanism of ethanol-induced neurotoxicity and cell death that could be targeted with MAOI drug therapy to alleviate alcohol-related brain injury. Further examination of MAOIs to reduce alcohol use disorder-related brain injury could provide pivotal insight to future pharmacotherapeutic opportunities.

Keywords: BDNF; Binge ethanol; Caspase-3; Kruppel-like factor 11 (KLF11); Monoamine oxidase (MAO); Neurotoxicity; Protein oxidation; Rats; Transcription factor.