Comparative proteomic analysis of human SH-SY5Y neuroblastoma cells under simulated microgravity

Microgravity is one of the most important features in spaceflight. Previous evidence has shown that neurophysiological impairment signs occurred under microgravity. The present study was undertaken to explore the change in protein abundance in human SH-SY5Y neuroblastoma cells that were grown in a microgravity environment. The comparative proteomic method based on the ¹⁸O labeling technique was applied to investigate the up-regulated proteins and down-regulated proteins in SH-SY5Y under simulated microgravity. Twenty-two differentially abundant proteins were quantified in human SH-SY5Y neuroblastoma cells. The cell microfilament network was disrupted under simulated microgravity, which was determined by the immunocytochemistry. The concentration of reactive oxygen species, malondialdehyde, and free Ca²⁺ ion significantly increased, and the level of ATP significantly decreased under simulated microgravity. However, there was no obvious cell apoptosis observed under simulated microgravity. These results provide new molecular evidence for the change in protein abundance in SH-SY5Y cells under simulated microgravity, which might unfold biological mechanisms and the development of effective countermeasures to deal with microgravity-related neurological problems. We believe that the state-of-the-art proteomic assay may be a means by which aerospace scientists will begin to understand the underlying mechanisms of space life activities at the protein level.