Proteomic Analysisof Human Plasma during IntermittentFasting

摘要

Intermittent fasting (IF) increases lifespan and decreases metabolic disease phenotypes and cancer risk in model organisms, but the health benefits of IF in humans are less clear. Human plasma derived from clinical trials is one of the most difficult sample sets to analyze using mass spectrometry-based proteomics due to the extensive sample preparation required and the need to process many samples to achieve statistical significance. Here, we describe an optimized and accessible device (Spin96) to accommodate up to 96 StageTips, a widely used sample preparation medium enabling efficient and consistent processing of samples prior to LC–MS/MS. We have applied this device to the analysis of human plasma from a clinical trial of IF. In this longitudinal study employing 8-weeks IF, we identified significant abundance differences induced by the IF intervention, including increased apolipoprotein A4 (APOA4) and decreased apolipoprotein C2 (APOC2) and C3 (APOC3). These changes correlated with a significant decrease in plasma triglycerides after the IF intervention. Given that these proteins have a role inregulating apolipoprotein particle metabolism, we propose that IFhad a positive effect on lipid metabolism through modulation of HDLparticle size and function. In addition, we applied a novel humanprotein variant database to detect common protein variants acrossthe participants. We show that consistent detection of clinicallyrelevant peptides derived from both alleles of many proteins is possible,including some that are associated with human metabolic phenotypes.Together, these findings illustrate the power of accessible workflowsfor proteomics analysis of clinical samples to yield significant biologicalinsight.