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.