Preconditioning of Hypoxic Culture Increases The Therapeutic Potential of Adipose Derived Mesenchymal Stem Cells
Various in vitro preconditioning strategies have been implemented to increase the regenerative capacity of MSCs. Among them are modulation of culture atmosphere (hypoxia or anoxia), three-dimensional culture (3D), addition of trophic factors (in the form of growth factors, cytokines or hormones), lipopolysaccharides, and pharmacological agents. Preconditioning mesenchymal stem cells by culturing them in a hypoxic environment, which resembles the natural oxygen environment of the tissues (1% –7%) and not with standard culture conditions (21%), increases the survival of these cells via Hypoxia Inducible Factor-1α (HIF-1a) and via Akt-dependent mechanisms. In addition, the hypoxic precondition stimulates the secretion of pro-angiogenic growth factors, increases the expression of chemokines SDF-1 (stromal cell-derived factor-1) and its receptor CXCR4 (chemokine receptor type 4) - CXCR7 (chemokine receptor type 7) and increases engraftment of stem cell. This review aims to provide an overview of the preconditioned hypoxic treatment to increase the therapeutic potential of adipose-derived mesenchymal stem cells.