Space travel presents many challenges to human health, including
radiation exposure and musculoskeletal disuse. In addition, astronauts lose
calcium from bones due to the uncoupling of bone formation and bone resorption.
Bone forming osteoblasts are derived from undifferentiated MSCs. In this study,
the ability of human adipose tissue derived stem cells (ATSC) to differentiate into
the osteoblastic lineage was examined after radiation exposure as well as
supplementation with osteogenic medium additives. After exposure to ionizing
radiation changes in cellular morphology, cell cycle progression, as well as cellular
radiosensitivity was characterized. Exposure to ionizing radiation resulted in an
accumulation of cells in the G2/M phase of the cell cycle, concerning both cell
lines. Alizarin Red S staining as well as quantitative determination of bone cell
differentiation was performed by analyzing the hydroxyapatite content of the ECM.
The results demonstrated LW24 deposited less calcium compared to SAOS-2.
Additionally, gene expression analysis during differentiation process revealed
expression of genes that are required for skeletal development, bone mineral
metabolism and transcription factors. Detailed investigation of stem cell
differentiation after radiation exposure is required to assure health of astronauts in
upcoming space missions