Fig. 6

26S proteasome poor function and mitochondrial damage under severe hypoxia triggers apoptosis in human BM-MSCs. Human BM-MSCs were treated with 26S MG132 inhibitor, (10 µm) and two different hypoxia percentages: 2.5% (moderate hypoxia) and 0.5% (severe hypoxia) for 24 h. a The survival P-AKT protein levels were analyzed by Western blot analysis. The results indicated a significant drop in P-AKT/AKT ratio after the inhibition of 26S proteasome and under severe hypoxia in comparison with normoxia and moderate hypoxia, whereas in moderate hypoxia, P-AKT/AKT protein ratio remained sufficient similarly to normoxia. n = 3; b BAX/BCL-XL ratio, which is an indicator of apoptosis stimulation, showed a noticeable in human BM-MSCs treated with MG132 inhibitor with parallel trend in severe hypoxia compared to normoxia and moderate hypoxia. On the other hand, BAX/BCL-XL ratio inappreciably changed. n = 3. *p < 0.05 compared to normoxia group; #p < 0.05 compared to moderate hypoxia. Each experiment was repeated 3 times