Ethanol Prevents Oxidant-Induced Mitochondrial Permeability Transition Pore Opening in Cardiac Cells

    loading  Checking for direct PDF access through Ovid

Abstract

Aims

The purpose of this study was to determine if ethanol prevents the mitochondrial permeability transition pore (mPTP) opening via glycogen synthase kinase 3β (GSK-3β).

Methods

Cardiac H9c2 cells were exposed to ethanol (10–1000 μM) for 20 min. GSK-3β activity was determined by measuring its phosphorylation at Ser9. Mitochondrial membrane potential (ΔΨm) was assessed by imaging (confocal microscopy) H9c2 cells loaded with tetramethylrhodamine ethyl ester (TMRE). To activate GSK-3β, cells were transfected with constitutively active GSK-3β (GSK-3β-S9A-HA) mutant plasmid.

Results

Treatment of cardiac cells with low doses of ethanol (10–500 μM) significantly enhanced GSK-3β phosphorylation, indicating that ethanol can inactivate GSK-3β in H9c2 cells. The effect of ethanol on GSK-3β activity was reversed by the phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 and ethanol could enhance Akt phosphorylation, implying that the PI3K/Akt pathway accounts for the action of ethanol. Ethanol prevented oxidant (H2O2)-induced loss ΔΨm, an effect that was reversed by LY294002, indicating that ethanol can modulate the mPTP opening caused by oxidant stress through the PI3K/Akt pathway. Ethanol failed to preserve ΔΨm in cells transfected with the constitutively active GSK-3β (GSK-3β-S9A-HA) mutant, suggesting that ethanol prevents the mPTP opening by inactivating GSK-3β.

Conclusions

These data suggest that ethanol prevents the mPTP opening through inactivation of GSK-3β. The PI3K/Akt signaling pathway is responsible for inactivation of GSK-3β by ethanol.

Related Topics

    loading  Loading Related Articles