Simulated Microgravity Condition Alters the Gene Expression of some ECM and Adhesive Molecules in Adipose-Derived Stem Cells

Adipose-derived stem cells (ADSCs) are widely used for tissue engineering and regenerative medicine. The beneficial effects of ADSCs on wound healing have already been reported. Remodeling of extracellular matrix (ECM) is the most important physiological event during the wound healing. ECM is sensitive to mechanical stresses and the expression of its components can be therefore influenced. The aim of this study was to investigate the effect of simulated microgravity on the gene expression of some ECM and adhesion molecules in human ADSCs. After isolation and characterization of ADSCs, cells were exposed to simulated microgravity for 1, 3 and 7 days.  Real-time PCR, fluorescence immunocytochemistry, and MTT assay were performed to evaluate the alterations of integrin subunit beta 1 (ITGB1), collagen type 3 (ColIII), matrix metalloproteinase-1 (MMP1), CD44, fibrillin (FBN1), vimentin (VIM) genes, and ColIII protein levels as well as cells viability. Microgravity simulation increased the expression of ITGB1, ColIII, MMP1, and CD44 and declined the expression of FBN1 and VIM genes. ColIII protein levels were also increased.  There were no significant changes in the viability of cells cultured in microgravity. Since the high expression of ECM components is known as one of the fibroblast markers, our data suggest that pretreatment of ADSCs by simulated microgravity may increase their differentiation capacity towards fibroblastic cells. Microgravity had not adversely affected the viability of ADSCs, and it is likely to be used alone or in combination with biochemical inducers for cell manipulation.