Comprehensive Proteomics Profiling Reveals Biomarkers of Oxidative Stress and Membrane Integrity in Red Blood Cells in Acute Altitude Sickness

Red blood cells (RBCs) are vital for oxygen transport and play a key role in acute mountain sickness (AMS). Phosphorylation is one of the most rapid post-translational modifications in response to environmental changes. However, the relationship between the changes of phosphoproteins in the RBC membrane and AMS has not received much attention. We conducted proteomic and phosphoproteomic profiling of RBC (including reticulocytes and mature erythrocytes) membranes from AMS and non-AMS individuals, identifying 2383 proteins, 1076 phosphoproteins, and 2913 phosphopeptides. Specifically, AMS caused significant content changes in the proteins and phosphorylation events of the tricarboxylic acid cycle, cytoskeleton, and peroxisome. We further determined the membrane proteins and phosphopeptides related to the severity of AMS. Experimentally, RBCs in AMS exhibited excessive oxidative stress and disruption of membrane integrity. Furthermore, functional enrichment and kinase prediction analysis indicated that the kinase activities of SRC and PRKCG were significantly elevated in AMS and that these two kinases were involved in various processes of RBC injury. Mechanically, we found that inhibition of SRC and PRKCG kinase activity alleviated the destruction of the RBC integrity caused by hypoxia. This study revealed characteristic protein and phosphoprotein changes in the RBC membrane of AMS patients, which provided a valuable resource for drug development against AMS.