miR-30 Regulates Mitochondrial Fission through Targeting p53 and the Dynamin-Related Protein-1 Pathway
Figure 6
Drp1 is required for p53 to trigger mitochondrial fission.
(A) Knockdown of Drp1 abolishes mitochondrial fission induced by p53. Cardiomyocytes were infected with AdDrp1RNAi or AdDrp1-S-RNAi at a moi of 70. 24 h after infection cells were treated with Adp53 at a moi of 50. Cells were harvested 24 h after treatment for the detection of Drp1 protein levels (upper panel) or mitochondrial fission (low panel). *p<0.05, compared with p53 alone. (B) Knockdown of Drp1 abolishes apoptosis induced by p53. Cardiomyocytes were treated as described for (A). TUNEL assay was performed 36 h after p53 infection. *p<0.05, compared with p53 alone. (C) Knockdown of Drp1 abolishes mitochondrial fission induced by hydrogen peroxide. Cardiomyocytes were treated with Drp1 RNAi as described for (A). Cells were harvested 6 h after treatment for the detection of Drp1 protein levels (upper panel) or mitochondrial fission (low panel). *p<0.05, compared with hydrogen peroxide alone. (D) Knockdown of Drp1 abolishes apoptosis induced by hydrogen peroxide. Cardiomyocytes were treated as described for (C). TUNEL assay was performed 12 h after treatment. *p<0.05, compared with hydrogen peroxide alone. (E) Overexpression of the mutated Drp1 induces mitochondrial fragmentation and caspase-3 activation. Cardiomyocytes were transfected with the constructs of wild-type Drp1-GFP (wt-Drp1-GFP) or the mutated Drp1-GFP (m-Drp1-GFP). Cells were stained with mitoTracker to monitor mitochondrial morphology. Caspase-3 activity was quantitatively analyzed (right panel). *p<0.05, compared with the control. Data are expressed as the mean±SEM of three independent experiments.