Protein profiling in the habenula after chronic (-)-menthol exposure in mice.

Abstract

The identification of proteins that are altered following nicotine/tobacco exposure can facilitate and positively impact the investigation of related diseases. In this report, we investigated the effects of chronic (-)-menthol exposure in 14murine brain regions for changes in total β2subunit protein levels and changes in epibatidine binding levels using immunoblotting and radioligand binding assays. We identified the habenula as a region of interest due to the region's marked decreases in β2subunit and nAChR levels in response to chronic (-)-menthol alone. Thus, we further examined the habenula, a brain region associated with both the reward and withdrawal components of addiction, for additional protein level alterations using mass spectrometry. A total of 552 proteins with altered levels were identified after chronic (-)-menthol exposure. Enriched in the proteins with altered levels after (-)-menthol exposure were proteins associated with signaling, immune systems, RNA regulation, and protein transport. The continuation and expansion of the brain region-specific protein profiling in response to (-)-menthol will provide a better understanding of how this common flavorant in tobacco and e-liquid products may affect addiction and general health.