Fig. 4
Valproic acid enhances the immunosuppressive activity as well as the glycolysis and cellular respiration of MSCs. MSCs of various batches were pretreated with 1 mM VPA for 6 days and were either subjected to T-cell proliferation assays with PBMCs or to metabolic measurements in monoculture. a VPA increases the MSC-mediated T-cell inhibition. Suppressive capacity toward CD4+ T-cells is shown for MSCs seeded at densities of 2.5 × 104 (n = 7) and 5 × 104 (n = 3) cells. VPA (1 mM) was used either for pretreatment of MSCs before onset of the assay or directly in coculture of PBMCs with untreated MSCs. Data were normalized to T-cell proliferation without the presence of MSCs. VPA-dependent increase of MSC b ECAR and c OCR after 6 days of VPA pretreatment (n = 1 in eightfold repetition). ECAR extracellular acidification rate, MSC mesenchymal stem cells, OCR oxygen consumption rate, VPA valproic acid. *p ≤ 0.05, **p ≤ 0.01, ***p ≤ 0.001