Fig. 3

26S proteasome functional status in human BM-MSCs under hypoxia controls their survival. Human BM-MSCs were treated with MG132 inhibitor (10 µm) and two different hypoxia percentages: 2.5% (moderate hypoxia) and 0.5% (sever hypoxia) for 24 h. a LDH cytotoxicity test was carried out after human BM-MSCs being exposed to the above corresponding treatments. The cytotoxicity of human BM-MSCs was hugely elevated after treating them with MG132 inhibitor as well as with severe hypoxia compared to normoxia and moderate hypoxia. Moderate hypoxia instigated no significant increase in the cytotoxicity level in human BM-MSCs. n = 8. b Viability assay was performed using live detection dye calcein-AM and dead detection dye ethidium homodimer-1; the results showed a significant decline in human BM-MSCs viability after using MG132 inhibitor with similar results in severe hypoxia compared to normoxia and moderate hypoxia. In moderate hypoxia, the survival of human BM-MSCs was high in parallel to normoxia. n = 4: *p < 0.05 compared to normoxia group; #p < 0.05 compared to moderate hypoxia. Each experiment was repeated 3 times