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- Neuzil, J., et al.
(författare)
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Mitochondria transmit apoptosis signalling in cardiomyocyte-like cells and isolated hearts exposed to experimental ischemia-reperfusion injury
- 2007
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Ingår i: Redox report. - 1351-0002 .- 1743-2928. ; 12:3, s. 148-162
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Tidskriftsartikel (refereegranskat)abstract
- Ischemia-reperfusion (I/R) is a condition leading to serious complications due to death of cardiac myocytes. We used the cardiomyocyte-like cell line H9c2 to study the mechanism underlying cell damage. Exposure of the cells to simulated I/R lead to their apoptosis. Over-expression of Bcl-2 and Bcl-xL protected the cells from apoptosis while over-expression of Bax sensitized them to programmed cell death induction. Mitochondria-targeted coenzyme Q (mitoQ) and superoxide dismutase both inhibited accumulation of reactive oxygen species (ROS) and apoptosis induction. Notably, mtDNA-deficient cells responded to I/R by decreased ROS generation and apoptosis. Using both in situ and in vivo approaches, it was found that apoptosis occurred during reperfusion following ischemia, and recovery was enhanced when hearts from mice were supplemented with mitoQ. In conclusion, I/R results in apoptosis in cultured cardiac myocytes and heart tissue largely via generation of mitochondria-derived superoxide, with ensuing apoptosis during the reperfusion phase. © W. S. Maney & Son Ltd.
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| 2. |
- Dong, Lan-Feng, et al.
(författare)
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Suppression of Tumor Growth In vivo by the Mitocan alpha-tocopheryl Succinate Requires Respiratory Complex II
- 2009
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Ingår i: CLINICAL CANCER RESEARCH. - 1078-0432. ; 15:5, s. 1593-1600
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Vitamin E analogues are potent novel anticancer drugs. The purpose of this study was to elucidate the cellular target by which these agents, represented by alpha-tocopoheryl succinate (alpha-TOS), suppress tumors in vivo, with the focus on the mitochondrial complex II (CII). Experimental Design: Chinese hamster lung fibroblasts with functional, dysfunctional, and reconstituted CII were transformed using H-Ras. The cells were then used to form xenografts in immunocompromized mice, and response of the cells and the tumors to alpha-TOS was studied. Results: The CII-functional and CII-reconstituted cells, unlike their CII-dysfunctional counterparts, responded to alpha-TOS by reactive oxygen species generation and apoptosis execution. Tumors derived from these cell lines reciprocated their responses to alpha-TOS. Thus, growth of CII-functional and CII-reconstituted tumors was strongly suppressed by the agent, and this was accompanied by high level of apoptosis induction in the tumor cells. On the other hand, alpha-TOS did not inhibit the CII-dysfuntional tumors. Conclusions: We document in this report a novel paradigm, according to which the mitochondrial CII, which rarely mutates in human neoplasias, is a plausible target for anticancer drugs from the group of vitamin E analogues, providing support for their testing in clinical trials.
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