Evaluation of cardiovascular system state by urine proteome after manned space flight

Abstract

In order to find markers to assess the functional state of the cardiovascular system (CVS) before and after spaceflight (first and seventh day after landing), we analyzed the urine proteome composition of 10 Russian cosmonauts aged of 35–51 years who have completed 169–199-day spaceflight onboard the International Space Station (ISS). Also an analysis of urine samples of 6 cosmonaut back-ups was conducted. A special sample preparation was performed, followed by liquid chromatography-mass spectrometry. It was shown that after long duration space flight concentration of several proteins of CVS in urine samples varies significantly. The dynamic of presence in urine of thioredoxin and apolipoprotein A-I could be related to the spaceflight, as it were not found before flight and in back-up controls, but were detected after the spaceflight. It was found that changes in cosmonauts’ urine proteome comprehensively reflect the adaptive responses of cardiovascular, renal and neuroendocrine systems to long-duration microgravity conditions.The use of bioinformatics analysis to the reconstruction of protein-protein interaction networks and the identification of overrepresented Gene Ontology (GO) biological processes related to the cardiovascular system allowed us to establish relationships between proteomic data and physiological effects observed in cosmonauts after the flight. Hypotheses on the possible pathogenesis and etiological factors causing this adaptive response were suggested in this work.