Figure 7

Hypoxic stress accelerates c-Myc protein degradation in cardiac progenitor cells. (A) Time-course analysis of c-Myc RNA (black bars) and protein (gray bars) expression under hypoxia relative to normoxia (n = 4–7, *p < 0.05). (B) Representative western blot image showing c-Myc protein degradation after translation blockage in CPCs cultured under normoxia and hypoxia for 48 hours. (C) Time-course analysis of c-Myc expression after protein synthesis blockage under normoxia (black bars) and hypoxia (gray bars) (n = 4–12, *p < 0.05, **p < 0.006, ^#p < 0.005, ^Ɨp < 0.001). (D) Representative western blot image showing the effect of the proteasome inhibitor MG132 on c-Myc expression under hypoxia (n = 4, *p < 0.05, **p < 0.005). Graphs in C and D represent c-Myc expression determined by densitometry analysis of all blots normalized to Actin endogenous control. For statistical purposes, c-Myc expression was compared between groups for each time point (*) and between time points for each experimental group, normoxia control (#) and hypoxia (Ɨ).