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Impairment with various antioxidants of the loss of mitochondrial transmembrane potential and of the cytosolic release of cytochrome c occuring during 7-ketocholesterol-induced apoptosis
Previous investigations of our laboratory have shown that 7-ketocholesterol was a potent inducer of apoptosis involving a release of cytochrome c into the cytosol, and a lipid peroxidation process that could be the consequence of a production of radical oxygen species. According to these considerati...
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Published in: | Free radical biology & medicine 2000-03, Vol.28 (5), p.743-753 |
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Main Authors: | , , , , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
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Summary: | Previous investigations of our laboratory have shown that 7-ketocholesterol was a potent inducer of apoptosis involving a release of cytochrome
c into the cytosol, and a lipid peroxidation process that could be the consequence of a production of radical oxygen species. According to these considerations, we asked whether some antioxidants were able to counteract 7-ketocholesterol-induced apoptosis, and whether prevention of cell death was associated with the impairment of mitochondrial events implied in the commitment to apoptosis, i.e., opening of the mitochondrial megachannels leading to the loss of the mitochondrial transmembrane potential (ΔΨm), and release of cytochrome
c from mitochondria into the cytosol. To this end, we studied the effects of glutathione (15 mM),
N-acetylcysteine (15 mM), vitamin E (100 μM), vitamin C (50 μM) and melatonin (1 mM) on U937 cells treated with 7-ketocholesterol (40 μg/ml). Only glutathione,
N-acetylcysteine, and vitamin E prevented apoptosis measured by the occurrence of cells with condensed and/or fragmented nuclei, as well as the loss of ΔΨm, and the release of cytochrome
c. However, all the antioxidants used were potent inhibitors of the production of O
2
• occuring under treatment with 7-ketocholesterol. Collectively, our data demonstrate that impairment of apoptosis by glutathione,
N-acetylcysteine, and vitamin E correlates with the prevention of mitochondrial dysfunctions, and they underline that the ability of antioxidants to counteract 7-ketocholesterol-induced apoptosis does not only depend on their capability to inhibit the production of O
2
•. |
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ISSN: | 0891-5849 1873-4596 |
DOI: | 10.1016/S0891-5849(00)00163-5 |