Fig. 8: IL-22 and GM-CSF interfere with the regenerative potential of progenitor cells.

The two cytokines were tested individually at different concentrations to determine their effects on the differentiation and migratory/proliferative potential of mesenchymal stromal cells as well as the angiogenic potential of endothelial cells to form new tubes in vitro. IL-22 increased the mineralization of the extracellular matrix in the osteogenic differentiation assays, but higher concentrations of IL-22 decreased migratory and proliferative potential and inhibited the de novo formation of new vessels by reducing the tube number and branching points. GM-CSF predominantly interfered with the migratory and proliferative behavior of MSCs but did not inhibit the angiogenic potential of endothelial cells. EM expansion medium, OM osteogenic medium, AM adipogenic medium, CM chondrogenic medium; n = 5 MSC donors per assay, n = 5 pooled endothelial cell (HUVEC) donors, tested in triplicate; unpaired t-test.