N-acetylcysteine prevents glucose/glucose oxidase-induced oxidative stress, mitochondrial damage and apoptosis in H9c2 cells.
OBJECTIVE
High blood glucose may auto-oxidize and generate free radicals, which are proposed to induce apoptosis in cardiac cells. The aim of the present study was to investigate the cell damage induced by glucose/glucose oxidase-dependent oxidative stress and the protective effect of N-acetylcysteine (NAC) on H9c2 cardiac muscle cells.


METHODS
H9c2 cells were exposed to 33 mM glucose (G)+1.6 milliunits (mU) of glucose oxidase (GO) and termed G/GO. Cell apoptosis, generation of reactive oxygen species (ROS-super oxide anion and hydrogen peroxide) and reactive nitrogen species (RNS-peroxinitrite), and the change in mitochondrial membrane potential (DeltaPsim) was studied using flow cytometry and confocal microscopy, and cytochrome c release was measured using confocal microscopy. The expression of Bcl-2, Bax and the activation of procaspase-9 was studied by western blot.


RESULTS
Exposure of H9c2 cells to G/GO resulted in a significant increase in cellular apoptosis (P<0.05) and the generation of ROS and RNS (P<0.001). Further, G/GO treatment led to a decrease in DeltaPsim, release of cytochrome c, decrease in Bcl-2, increase in Bax expression and the activation of procaspase-9. Treatment with NAC significantly decreased apoptosis (P<0.05) and reduced the levels of ROS and RNS (P<0.001). NAC was also able to normalize DeltaPsim, inhibit cytochrome c release, increase Bcl-2 and decrease Bax expression and procaspase-9 activation.


CONCLUSIONS
Our studies suggest that NAC has antioxidative and antiapoptotic activity against G/GO-induced oxidative stress through the inhibition of mitochondrial damage in H9c2 cells.
Kumar
Santosh
S
National Centre for Cell Science, NCCS Complex, Ganeshkhind, Pune 411007, India.
Sitasawad
Sandhya L
SL
D000111:Acetylcysteine / Q000494:pharmacology*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D002460:Cell Line; D045304:Cytochromes c / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005947:Glucose / Q000378:metabolism / Q000494:pharmacology*; D005949:Glucose Oxidase / Q000378:metabolism / Q000494:pharmacology*; D006943:Hyperglycemia / Q000378:metabolism / Q000473:pathology; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008929:Mitochondria, Heart / Q000187:drug effects* / Q000378:metabolism; D032383:Myocytes, Cardiac / Q000187:drug effects* / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects*; D030421:Peroxynitrous Acid / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism
D017382:Reactive Oxygen Species; D030421:Peroxynitrous Acid; D045304:Cytochromes c; D005949:Glucose Oxidase; D005947:Glucose; D000111:Acetylcysteine