Impact of diet-induced obesity on the mouse brain phosphoproteome

Obesity is closely associated to several diseases such as type 2 diabetes, cardiovascular disease, hepatic steatosis, airway disease, neurodegeneration, biliary diseases and certain cancers. It is, therefore, of importance to assess the role of nutrition in disease prevention as well as its effect in the course of such pathologies. In the present study, we addressed the impact of the exposure to different obesogenic diets in the mice brains phosphoproteome. To analyze if the obesity could be able to modify the protein pattern expression of brain neurons, obesity was induced in two different groups of mice. One group of mice was fed with hyperglycemic diet (HGD) and the other one was fed with high-fat diet (HFD), both for 12 weeks. A control group of lean mice was fed with a standard diet (SD). Metabolic parameters were measured before sacrifice, and brains were harvested for label-free phosphoproteomic analysis. Mice brains were analyzed to find differences, if any, in protein phosphorylation. Interestingly, the changes were independent of the obesogenic diet as no changes were detected between the two obese groups. Dephosphorylation of proteins involved in neuronal development (among others SYNGAP1 and PPP1R9B), in vesicle trafficking (for example SNAP91 and AMPH) and in cytoskeletal functions (for example, CLASP2 and GSK3B) was identified, while increased phosphorylation was detected for microtubule proteins (such as MAP2 and MAPT). Phospho site analysis of the mouse brain proteome reveals important changes that point to a connection between diet-induced obesity and impairment of neuronal functions and signaling.