To investigate the function of mitofusin2 (Mfn2) on senescence and apoptosis of endothelial progenitor cells (EPCs) induced by doxorubicin (Dox).

EPCs isolated from peripheral blood of rats were divided into three groups, control group, mock-vehicle group and Mfn2 overexpression group. EPCs were treated with 0.2 μmol/L or 2.0 μmol/L Dox. Mitochondrial fission results were confirmed by laser-scanning confocal microscopy, cellular senescence and apoptosis were examined by β galactosidase (β-gal) activity assays and terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL) staining. Western blotting and reverse transcription quantitative real-time polymerase chain reaction were applied to detect the expression of inhibitor of cyclin-dependent kinase 4a (P16INK4A). The measurement data in accordance with normal distribution were expressed as mean±standard deviation, and the means of multiple groups were compared by single factor analysis of variance.

Compared with control group [(19.16±0.82)%, (68.56±5.31)%] and mock-vehicle group [(17.53±2.86)%, (66.54±2.86)%], the percentage of cells with mitochondrial fission was significantly decreased in Mfn2 group [(5.83±1.71)%, (6.72±0.57)%] with the treatment of 0.2 μmol/L and 2.0 μmol/L Dox (F=40.403, 302.725, P<0.05). After treatment with 0.2 μmol/L Dox, the percentage of β-gal+ cells in Mfn2 group [(15.0±0.33)%] was significantly decreased (F=637.291, P<0.05) as compared with control group [(35.00±0.61)%] and mock-vehicle group [(36.00±1.23)%]. Furthermore, after treatment with 2 μmol/L Dox, the percentage of TUNEL+ cells in Mfn2 group [(11.90±0.50)%] was significantly less than in control group [(34.50±0.80)%] and mock-vehicle group [(35.20±1.60)%] (F=458.327, P<0.05). In the end, after treatment with 0.2 μmol/L Dox, the mRNA levels of eNOS (0.65±0.02) and vWF (0.65±0.01) in Mfn2 group were significantly increased as compared with control group [(0.43±0.03, 0.50±0.02)] and mock-vehicle group [(0.34±0.02, 0.48±0.02),F=134.643, 71.646, P<0.05]. Meanwhile, under 2 μmol/L Dox treatment, the mRNA levels of eNOS (0.71±0.02) and vWF (0.66±0.03) in Mfn2 group were significantly increased as compared with control group [(0.33±0.02, 0.28±0.02)] and mock-vehicle group [(0.38±0.03, 0.35±0.01),F=225.712, 262.934, P<0.05].

Mfn2 overexpression could inhibit mitochondrial fission and antagonise senescence and apoptosis of EPCs induced by Dox.

Mitofusin 2; Endothelial progenitorcells; Gene transfection; Doxorubicin; Mitochondrial