Dihydromyricetin induces mitophagy by regulating Prohibitin 2 pathway in vascular endothelial cells

Objective To observe the effects of dihydromyricetin on mitophagy in vascular endothelial cells, and to clarify the underlying role of Prohibitin 2 in the process. Methods After human umbilical vein endothelial cells (HUVECs) were treated with different concentrations of dihydromyricetin (0, 0.1, 1, 10, 100 μmol/L) for 12 h, intensity of MitoTracker® Deep Red (MTDR, a widely used mitochondria-selective probe) was determined for mitochondrial staining by fluorescence microscopy and flow cytometry, and the expression of Prohibitin 2 at mRNA and protein levels as determined by qRT-PCR and Western blotting, respectively. Furthermore, after treatment with of without control/Prohibitin 2 siRNA, HUVECs were incubated with dihydromyricetin for 12 h or carbonyl cyanide 3-chlorophenyl hydrazone (CCCP) for 6 h in the presence of the lysosomal blocker chloroquine, and then subjected to flow cytometry analysis to determine mitophagy. Results As compared with the non-dihydromyricetin group, dihydromyricetin (≥ 0.1μmol/L) treatment markedly decreased MTDR fluorescence levels (P < 0.05), and meanwhile, the treatment significantly increased the mRNA and protein levels of Prohibitin 2 (P < 0.05). After pretreated with chloroquine, dihydromyricetin (≥10 μmol/L) significantly enhanced mitophagy in HUVECs, which was consistent with the effect of CCCP (P < 0.05). After Prohibitin 2 siRNA transfection, mitophagy induced by dihydromyricetin was significantly suppressed when compared with the control siRNA treatment group (P < 0.05). Conclusion Dihydromyricetin enhances mitophagy in vascular endothelial cells by regulating Prohibitin 2.