[The role of released cytochrome C from mitochondria in the apoptosis of HUVECs induced by hydrogen peroxide].
OBJECTIVE
To explore the role of mitochondria and from which released cytochrome C in the apoptosis of HUVECs induced by H2O2.


METHODS
HUVECs were cultured with H2O2 of 100 mol/L for 24 hrs. H2O2 was added after that HUVECs were precultured with CsA (cyclosporin A) for 30 mins. The cell samples were collected at different time points for DAPI staining and counting of apoptotic cell number. Simultaneously, the changes of mitochondrial permeability was observed by Rhoadmine 123 accumulation. The changes of the cytochrome C concentrations in plasma and mitochondria were determined by western blot.


RESULTS
HUVECs exhibited obvious apoptosis after being processed by H2O2. The apoptotic cell number increased since 4 hrs of culturation of HUVECs with H2O2, and reached peak level at 12 hrs. And the HUVEC apoptosis induced by H2O2 could be inhibited significantly by CsA. H2O2 could lead to the decrease of mitochondrial cytochrome C concentration, which in turn lead to the increase of cytoplasmic cytochrome C concentration. Similarly, mitochondrial Rhoadmine 123 concentration decreased and the mitochondrial permeability increased. But CsA could obviously inhibit the changes of both mitochondrial Rhoadmine 123 and permeability.


CONCLUSIONS
H2O2 could induce cytochrome C releasing to cytoplasma which lead to endothelial apoptosis. And CsA could inhibit the apoptosis by maintaining the normal function of mitochondrial membrane.
Yuan
J
J
Institute of Burn Research, Southwestern Hospital, Third Military Medical University 400038, P. R. China.
Cheng
J
J
Qin
X
X
D017209:Apoptosis; D002478:Cells, Cultured; D016572:Cyclosporine / Q000494:pharmacology; D003574:Cytochrome c Group / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000166:cytology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007425:Intracellular Membranes / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D010539:Permeability / Q000187:drug effects
D003574:Cytochrome c Group; D004791:Enzyme Inhibitors; D016572:Cyclosporine; D006861:Hydrogen Peroxide