Quantitative dynamic proteome biology of anterior mice hippocampus

Neurodegeneration is a molecular process that occurs during several brain diseases (Parkinson, Alzheimer, Epilepsies). This process leads to the reorganization of synapses and neurons in the Central Nervous System. The search for early medication to reduce neurodegeneration is a major challenge in Neuroscience. To this aim, VALAPODYN, a European Commission-funded research network, develops functional genomics and proteomics related to the dynamics of molecular interaction networks (MIN). MIN modeling investigates protein-protein interactions and regulation networks. Using a mouse model of induced hippocampal cell loss associated with focal epilepsy, dynamic protein expression analyses were conducted at 10 successive time-points during the first 24h. Protein expression was analysed by mass spectrometry, using a “classical” gel-based method as a means of covering all modulated proteins at each considered time-points. Proteins were extracted from minutes amount of frozen hippocampal samples and subjected on two-dimensional difference in-gel electrophoresis (2D-DIGE). This analysis allows quantification of cyanine-labelled proteins. A total of 252 differentially regulated proteins spots were picked digested and identified using MALDI/TOF-TOF mass spectrometry. Overall the expressions of 127 different proteins were identified as reproducibly modulated over the time-range studied. Several proteins have multiple protein spots resulting from different isoforms. The functional annotation of these proteins shows that, among other mechanisms, most of them are involved in the response to stress, synapse remodelling, neuron development, and intracellular signal transduction.