Mass Spectrometry

Biography

Biography: Alvhild Alette Bjørkum

Abstract

Introduction; Cell stress might be a consequence of Sleep deprivation (SD). Cellular stress might be reflected in changed protein profiles and amount and type of specific proteins in blood serum after SD. These possible changes might hints to SD-affected cellular structures, -mechanisms and important -signalling pathways. Methods; Humans (n=6-8) was subjected 6 hours of SD and blood were sampled before, during and after a SD-night, within subject design. Initially, Seldi-Tof-MS (Ciphergen), Maldi-Tof-MS (AutoFlex, Bruker Daltonics) was used. Later, iTRAQ labeled peptides were fractionated (mixed-mode fraction) and run on LC-MS/MS were fifty mix mode fractions from each iTRAQ experiment were analysed on an LTQ-Orbitrap Velos Elite (Thermo Scientific) connected to a Dionex Ultimate NCR-3000RS LC system. Result; In the first dataset protein-profile changes (in the m/z spectrum) after SD were searched for by principal component analysis (PCA, Sirius 7.0-PRS), support vector machine- and decision three-models analysing the mass spectrometry data and showed differentially expressed proteins after 6 h of SD at night. We identified approximately 800 proteins where 34 of them were significantly changed after 6 h of SD. Three proteins changed above the 1.5-fold limit. Examples are Histone H4 that increased 2.3-fold and S1006A that increased 1.5-fold. Conclusion; SD might lead to cell stress. This seems reflected in changed protein profile in human serum. To be able to ID changed proteins and their interactions might shed light on the cellular mechanisms, possible affected extracellular matrix and or cellular pathways of interest to identify underlying sleep and/or being disturbed after SD.