Influence of oxygen in the cultivation of human mesenchymal stem cells in simulated microgravity: an explorative study

Previous studies indicated that human Adipose Tissue-derived Mesenchymal Stem Cells (AT-MSCs) cultured in simulated microgravity (sim-μg) in standard laboratory incubators alter their proliferation and differentiation. Recent studies on the stem cell (SC) niches and the influence of oxygen on SC proliferation, senescence, and differentiation point to oxygen level as one of the key regulators of SC fate. Here we present the results of a study that focussed at the evaluation of the influence of oxygen level in the cultivation of AT-MSCs in sim-μg. In detail, cells were cultured for 14 days in sim-μg using the Random Positioning Machine (RPM) and two different oxygen concentrations: 5 % and 20 %. The results were compared with those obtained at 1g in the same conditions. Affymetrix Human Gene 1.0 ST array and Gene Ontology (GO) analysis were performed. The results confirmed that in all of the sim-μg experiments oxygen concentration modulates cell signalling and adhesion, in line with the knowledge that sim-μg affects cell shape and cytoskeletal organization.