Proteomics Can Help to Gain Insights into Metabolic Disorders According to Body Reserve Availability

Metabolic disorders are amongst the most serious medical problems that are encountered in modern societies. To unravel the molecular mechanisms that underlie the metabolic adaptations to disturbed energy balance, wild and laboratory animal models are of primary importance. Previous studies have highlighted some aspects of the metabolic and endocrine variations that are triggered by marked energy reserve depletion/repletion. A brief overview of studies addressing the adaptive mechanisms to fasting/refeeding is presented here. This review also emphasises the necessity to not only consider gene or protein expression levels but to also take into account protein structures, to enable one to fully unravel the exact steps of intermediary metabolism and/or signal transduction pathways that are modulated by nutritional transitions. In this context, proteomic analysis, which uses high-performance tools for peptide/protein separation and mass spectrometry, has emerged as an indispensable tool to elucidate the complex molecular basis of various pathophysiological processes. Proteomics provides a global view of the protein dynamics in a given tissue of any organism. It provides hundreds of protein identifications and quantifications, as well as structure characterizations, from a single complex biological sample. Therefore, proteomic analysis is detailed here in terms of its analytical approaches, strategies, methods, instrumentation, and its limitations. The benefits of performing such analysis are discussed in the context of the fasting/refeeding paradigm and expected insights into the associated molecular mechanisms. Importantly, unravelling the adaptive responses to food deprivation may provide new therapeutic targets for the treatment and/or prevention of numerous pathophysiological conditions characterized by energy depletion.