The effects of simulated microgravity on the pattern of gene expression in human bone marrow mesenchymal stem cells under osteogenic differentiation

Abstract It is well-known that the modified gravity affects not only the organism as a whole, but also the molecular processes in individual cells. The goal of this study was to investigate the influence of simiulated microgravity (SMG) on gene expression pattern in cultured human bone marrow mesenchymal stem cells (hMSCs) after prolonged exposure to SMG on dRPM. It was found that the expression level of 144 genes significantly changed in hMSCs after 20 days of exposure to SMG: the expression of 30 genes significantly increased and 114 - decreased. Gene analysis revealed that these genes can be attributed to the 11 major categories corresponding to its biological role in the cells. The greatest number of genes with altered expression was found to be in the groups "Matrix and Adhesion", "Inflammation and Cell-to-Cell Communications", "Metabolism" and "Signalling". Interestingly, some of the genes with down-regulated expression were related to the bone development and differentiation (COL15A1, CXCL12, DPTand WISP2) or participated in the cell-to-cell communications ofhMSCs with other cell types (CXCL12, SDF4). The obtained results indicate that the changes in gene expression in bone marrow progenitor cells can be involved into space flight-induced osteopenia.