The energy-dense western diet significantly increases the risk of obesity, type 2 diabetes, cardiovascular episodes, stroke, and cancer. Recently more attention has been paid to the contribution of an unhealthy lifestyle on the development of central nervous system disorders. Exposure to long-lasting stress is one of the key lifestyle modifications associated with the increased prevalence of obesity and metabolic diseases. The main goal of the present study was to verify the hypothesis that exposure to chronic stress modifies alterations in the brain proteome induced by the western diet. Female adult rats were fed with the prepared chow reproducing the human western diet and/or subjected to chronic stress induced by social instability for 6 weeks. A control group of lean rats were fed with a standard diet. Being fed with the western diet resulted in an obese phenotype and induced changes in the serum metabolic parameters. The combination of the western diet and chronic stress exposure induced more profound changes in the rat cerebrocortical proteome profile than each of these factors individually. The down-regulation of proteins involved in neurotransmitter secretion (Rph3a, Snap25, Syn1) as well as in learning and memory processes (Map1a, Snap25, Tnr) were identified, while increased expression was detected for 14-3-3 protein gamma (Ywhag) engaged in the modulation of the insulin-signaling cascade in the brain. An analysis of the rat brain proteome reveals important changes that indicate that a combination of the western diet and stress exposure may lead to impairments of neuronal function and signaling.
Keywords: Global brain proteome; chronic stress; female rats; metabolic parameters; obesity; temporal cortex; unhealthy lifestyle; western diet.