Expression of miRNA-210 in human bone marrow-derived mesenchymal stromal cells under oxygen deprivation

Abstract : A major limitation in the development of efficient clinical protocols for mesenchymal stromal cell (MStroC)-based tissue regeneration therapy is the low retention and survival of MStroC in injured tissue after therapeutic administration. Low oxygen concentration preconditioning (LOP) during ex vivo cultivation of MStroC, as a method for mimicking oxygenation in their physiological microenvironment, has been shown to be beneficial in clinical trials using MStroC. Introducing hypoxia-mimicking molecules into MStroC during cultivation could be an advantageous LOP strategy. MicroRNA (miRNA) drugs are good candidates for this approach. Analysis of the expression of miRNA-210 in human bone marrow-derived MStroC in conditions of acute and extended hypoxia (24 to 72 h) was performed using RT-qPCR methodology. HIF-1α and HIF-2α gene knockdown cell lines were generated using lentiviral transduction of short hairpin RNA (shRNA) in order to examine whether miRNA-210 expression is regulated by transcription factor HIF-1 and/or HIF-2. We detected a significant increase in miRNA-210 expression in hypoxic conditions at time points of 24, 48 and 72 h (p˂0.05). Knocking down of HIF-1α and HIF-2α genes indicated involvement of both transcription factors in the elevation of miRNA-210 expression. These results point to miRNA-210 as a good candidate for a hypoxia-mimicking molecule in LOP strategy.