Lysenin, a Novel Sphingomyelin-specific Binding ProteinAkiko Yamaji, Yoshiyuki Sekizawa, Kazuo Emoto et al.|Journal of Biological Chemistry|1998 Lysenin, a novel 41-kDa protein purified from coelomic fluid of the earthworm Eisenia foetida, induced erythrocyte lysis. Preincubation of lysenin with vesicles containing sphingomyelin inhibited lysenin-induced hemolysis completely, whereas vesicles containing phospholipids other than sphingomyelin showed no inhibitory activity, suggesting that lysenin bound specifically to sphingomyelin on erythrocyte membranes. The specific binding of lysenin to sphingomyelin was confirmed by enzyme-linked immunosorbent assay, TLC immunostaining, and liposome lysis assay. In these assays, lysenin bound specifically to sphingomyelin and did not show any cross-reaction with other phospholipids including sphingomyelin analogs such as sphingosine, ceramide, and sphingosylphosphorylcholine, indicating that it recognized a precise molecular structure of sphingomyelin. Kinetic analysis of the lysenin-sphingomyelin interaction by surface plasmon resonance measurements using BIAcoreTM system showed that lysenin associated with membrane surfaces composed of sphingomyelin (kon = 3.2 x 10(4) M-1 s-1) and dissociated extremely slowly (koff = 1.7 x 10(-4) s-1), giving a low dissociation constant (KD = 5.3 x 10(-9) M). Incorporation of cholesterol into the sphingomyelin membrane significantly increased the total amount of lysenin bound to the membrane, whereas it did not change the kinetic parameters of the lysenin-membrane interaction, suggesting that lysenin specifically recognized sphingomyelin and cholesterol incorporation changed the topological distribution of sphingomyelin in the membranes, thereby increasing the accessibility of sphingomyelin to lysenin. Immunofluorescence staining of fibroblasts derived from a patient with Niemann-Pick disease type A showed that lysenin stained the surfaces of the fibroblasts uniformly, whereas intense lysosomal staining was observed when the cells were permeabilized by digitonin treatment. Preincubation of lysenin with vesicles containing sphingomyelin abolished lysenin immunostaining. This study demonstrated that lysenin bound specifically to sphingomyelin on cellular membranes and should be a useful tool to probe the molecular motion and function of sphingomyelin in biological membranes.
Mitochondrial Phospholipid Hydroperoxide Glutathione Peroxidase Plays a Major Role in Preventing Oxidative Injury to CellsMasayoshi Arai, Hirotaka Imai, Tomoko Koumura et al.|Journal of Biological Chemistry|1999 Phospholipid hydroperoxide glutathione peroxidase (PHGPx) is synthesized as a long form (L-form; 23 kDa) and a short form (S-form; 20 kDa). The L-form contains a leader sequence that is required for transport to mitochondria, whereas the S-form lacks the leader sequence. A construct encoding the leader sequence of PHGPx tagged with green fluorescent protein was used to transfect RBL-2H3 cells, and the fusion protein was transported to mitochondria. The L-form of PHGPx was identified as the mitochondrial form of PHGPx and the S-form as the non-mitochondrial form of PHGPx since preferential enrichment of mitochondria for PHGPx was detected in M15 cells that overexpressed theL-form of PHGPx, whereas no similar enrichment was detected in L9 cells that overexpressed the S-form. Cell death caused by mitochondrial injury due to potassium cyanide (KCN) or rotenone (chemical hypoxia) was considerably suppressed in the M15 cells, whereas the L9 cells and control RBL-2H3 cells (S1 cells, transfected with the vector alone) succumbed to the cytotoxic effects of KCN. Flow cytometric analysis showed that mitochondrial PHGPx suppressed the generation of hydroperoxide, the loss of mitochondrial membrane potential, and the loss of plasma membrane integrity that are induced by KCN. Mitochondrial PHGPx might prevent changes in mitochondrial functions and cell death by reducing intracellular hydroperoxides. Mitochondrial PHGPx failed to protect M15 cells from mitochondrial injury by carbonyl cyanide m-chlorophenylhydrazone, which directly reduces membrane potential without the generation of hydroperoxides. M15 cells were more resistant than L9 cells to cell death caused by direct damage to mitochondria and to extracellular oxidative stress. L9 cells were more resistant totert-butylhydroperoxide than S1 cells, whereas resistance to t-butylhydroperoxide was even more pronounced in M15 cells than in L9 cells. These results suggest that mitochondria might be a target for intracellular and extracellular oxidative stress and that mitochondrial PHGPx, as distinct form non-mitochondrial PHGPx, might play a primary role in protecting cells from oxidative stress. Phospholipid hydroperoxide glutathione peroxidase (PHGPx) is synthesized as a long form (L-form; 23 kDa) and a short form (S-form; 20 kDa). The L-form contains a leader sequence that is required for transport to mitochondria, whereas the S-form lacks the leader sequence. A construct encoding the leader sequence of PHGPx tagged with green fluorescent protein was used to transfect RBL-2H3 cells, and the fusion protein was transported to mitochondria. The L-form of PHGPx was identified as the mitochondrial form of PHGPx and the S-form as the non-mitochondrial form of PHGPx since preferential enrichment of mitochondria for PHGPx was detected in M15 cells that overexpressed theL-form of PHGPx, whereas no similar enrichment was detected in L9 cells that overexpressed the S-form. Cell death caused by mitochondrial injury due to potassium cyanide (KCN) or rotenone (chemical hypoxia) was considerably suppressed in the M15 cells, whereas the L9 cells and control RBL-2H3 cells (S1 cells, transfected with the vector alone) succumbed to the cytotoxic effects of KCN. Flow cytometric analysis showed that mitochondrial PHGPx suppressed the generation of hydroperoxide, the loss of mitochondrial membrane potential, and the loss of plasma membrane integrity that are induced by KCN. Mitochondrial PHGPx might prevent changes in mitochondrial functions and cell death by reducing intracellular hydroperoxides. Mitochondrial PHGPx failed to protect M15 cells from mitochondrial injury by carbonyl cyanide m-chlorophenylhydrazone, which directly reduces membrane potential without the generation of hydroperoxides. M15 cells were more resistant than L9 cells to cell death caused by direct damage to mitochondria and to extracellular oxidative stress. L9 cells were more resistant totert-butylhydroperoxide than S1 cells, whereas resistance to t-butylhydroperoxide was even more pronounced in M15 cells than in L9 cells. These results suggest that mitochondria might be a target for intracellular and extracellular oxidative stress and that mitochondrial PHGPx, as distinct form non-mitochondrial PHGPx, might play a primary role in protecting cells from oxidative stress. Mitochondria are a major physiological source of reactive oxygen species (ROS), 1The abbreviations ROSreactive oxygen speciesBSObuthionine sulfoximineCCCPcarbonyl cyanidem-chlorophenylhydrazonecGPxcytosolic glutathione peroxidaseDCFH-DA5,6-carboxy-2′,7′-dichlorofluorescein diacetateGFPgreen fluorescent proteinLDHlactate dehydrogenasePBSphosphate-buffered salinePHGPxphospholipid hydroperoxide glutathione peroxidasePIpropidium iodideRBLrat basophile leukemia cellsRh123rhodamine 123t-BuOOHtert-butylhydroperoxideTNF-αtumor necrosis factor-αSODsuperoxide dismutaseBSAbovine serum albumin which can be generated during mitochondrial respiration (1Guarnieri C. Muscari C. Caldarera C.M. Emerit I. Chance B. Free Radicals and Aging. Birkhauser Verlag, Basel1992: 73-77Crossref Scopus (21) Google Scholar). 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Pharmacother. 1994; 48: 199-214Crossref PubMed Scopus (43) Google Scholar, 5Tritschler H.J. Packer L. Medori R. Biochem. Mol. Biol. Int. 1994; 34: 169-181PubMed Google Scholar). However, ROS don't have exclusively toxic effects; low levels of ROS generated in mitochondria can act as signaling molecules under physiological conditions. ROS produced in mitochondria can activate transcription factors, such as NFκB and AP-1 (6Rao G.N. Glasgow W.C. Eling T.E. Runge M.S. J. Biol. Chem. 1996; 271: 27760-27764Abstract Full Text Full Text PDF PubMed Scopus (71) Google Scholar), and can function as signals in apoptosis that is induced by TNF-α (7Donato N.J. Perez M. J. Biol. Chem. 1998; 273: 5067-5072Abstract Full Text Full Text PDF PubMed Scopus (85) Google Scholar), ceramide (8Quillet-Mary A. Jaffrezou J.-P. Mansat V. Bordier C. Naval J. Laurent G. J. Biol. Chem. 1997; 272: 21388-21395Crossref PubMed Scopus (446) Google Scholar), and chemical hypoxia (9Shimizu S. Eguchi Y. Kamiike W. Matsuda H. Tsujimoto Y. Oncogene. 1996; 12: 2251-2257PubMed Google Scholar). reactive oxygen species buthionine sulfoximine carbonyl cyanidem-chlorophenylhydrazone cytosolic glutathione peroxidase 5,6-carboxy-2′,7′-dichlorofluorescein diacetate green fluorescent protein lactate dehydrogenase hydroperoxide glutathione peroxidase basophile leukemia cells necrosis serum albumin The of ROS in mitochondria is by mitochondrial that hydroperoxide glutathione peroxidase glutathione peroxidase and The of in mitochondria is by the that without a for from effects Y. S. C. PubMed Scopus Google Scholar). without a for are of resistant to oxidative stress even is the that is to the H2O2 produced by in mitochondria since mitochondria in cells Biochem. 1997; PubMed Scopus Google Scholar). of and PHGPx, are in mitochondria. PHGPx is the intracellular that can directly M. C. PubMed Scopus Google and M. J. Biol. Chem. Full Text PDF PubMed Google in PHGPx that can than is to contribute to the oxidative damage to mitochondria L. R. and Scholar). However, the PHGPx in mitochondria a for PHGPx from the H. A. M. A. N. Y. Y. J. Biochem. PubMed Scopus Google Scholar, M. H. N. Y. Biochem. 1996; PubMed Scopus Google and that a short and a long form of PHGPx were from the which potential for the of in M. H. N. Y. Biochem. 1996; PubMed Scopus Google Scholar). showed that the L-form a leader sequence and was the mitochondria of by an in M. H. N. Y. Biochem. 1996; PubMed Scopus Google Scholar). of basophile leukemia cells, in which the S-form of PHGPx was were resistant to the cell death caused by a radical or H. H. A. M. N. Y. Biochem. 1996; PubMed Scopus Google Scholar). The S-form of PHGPx the of by by of intracellular the H. M. H. N. Y. J. Biol. Chem. 1998; 273: Full Text Full Text PDF PubMed Scopus Google Scholar). the RBL-2H3 cells that overexpressed theL-form of PHGPx were and with that overexpressed the S-form in an to the of the of PHGPx in intracellular and extracellular oxidative stress. The L-form of PHGPx was more than the S-form in cell death that was caused by ROS generated in mitochondria and by hydroperoxides. PHGPx and were as H. H. A. M. N. Y. Biochem. 1996; PubMed Scopus Google Scholar). A were from and were from and were from and was from and were from A of M. H. N. Y. Biochem. 1996; PubMed Scopus Google was as the to construct PHGPx that theL-form of PHGPx Y. M. J. P. M. N. Mol. Biol. PubMed Google Scholar). and were from by chain reactions for of and The for of the in which the the from the of the S-form of PHGPx, were and The for of the in which the the from the of the L-form of PHGPx, were and The of and were the and of the vector that by H. S. Proc. Natl. Acad. Sci. U. S. A. PubMed Scopus Google Scholar). used the control of cells (S1 and L9 cells that overexpressed the S-form of PHGPx H. H. A. M. N. Y. Biochem. 1996; PubMed Scopus Google Scholar). M15 cells, which overexpressed the L-form of PHGPx, were by the of RBL-2H3 cells with PHGPx and by as H. H. A. M. N. Y. Biochem. 1996; PubMed Scopus Google Scholar). A of RBL-2H3 cells was to an with a of 20 of DNA, which of of vector and of used to resistance to P. J. Mol. Google Scholar). A potential of was with a and cell was a for resistance was and cells were exposed to for were with of of PHGPx were by with PHGPx, and cells that overexpressed the L-form of PHGPx were cells and cells that overexpressed the L-form or the S-form of PHGPx were in that serum and were with for to the of PHGPx and in cells. cells in were with and by with The cell was for and cells were as H. M. H. N. Y. J. Biol. Chem. 1998; 273: Full Text Full Text PDF PubMed Scopus Google Scholar). The cell was in and with and A a of and a of and for cells were in the and with a A and a were by for The was in of the and cytosolic from the were by as by C. R. R. Biochem. J. Scopus Google Scholar). was by for of mitochondrial and lactate dehydrogenase cytosolic as PubMed Scopus Google Scholar, Y. J. Biol. Chem. 1996; 271: Full Text Full Text PDF PubMed Scopus Google Scholar). The of as a was by with M. PubMed Scopus Google Scholar). The of of M15 cells was to in which the the of of control cells and non-mitochondrial PHGPx cells S1 and L9 cells H. M. H. N. Y. J. Biol. Chem. 1998; 273: Full Text Full Text PDF PubMed Scopus Google Scholar). The of in M15 cells was the as in S1 and L9 cells. was in and cytosolic of M15 cells. were in mitochondrial and cytosolic of M15 cells. The and were in of in for and was for The were of and to with PHGPx and as H. H. A. M. N. Y. Biochem. 1996; PubMed Scopus Google Scholar). were by under conditions. were and to levels of PHGPx and were from results of with a of PHGPx and were the of and mitochondria from cell Mitochondrial was and for The from mitochondrial and cytosolic were used for of PHGPx and PHGPx was by hydroperoxide as the to the H. M. H. N. Y. J. Biol. Chem. 1998; 273: Full Text Full Text PDF PubMed Scopus Google Scholar). of was by as the H. M. H. N. Y. J. Biol. Chem. 1998; 273: Full Text Full Text PDF PubMed Scopus Google Scholar). The of was in of the of the of by the I. PubMed Scopus Google Scholar). was in the of and was by of the of from the RBL-2H3 cells were transfected with that or by as cells were in in of that serum in an of in cells were for 20 with and with The of cells was and with an with a and a for and mitochondria were detected in the cells by the with and a of that was a for the mitochondrial Biochem. PubMed Scopus Google Scholar). cells were with and were with for The cells were with with for the cells were with and with to with for of and in the cells was and with an and M15 cells were in and for were exposed to of for The was used for the of the cell as H. H. A. M. N. Y. Biochem. 1996; PubMed Scopus Google Scholar). of cells were for to to with buthionine for of in the integrity of plasma membrane and in the mitochondrial membrane potential were by with and with cells were with and for used an fluorescent to levels of intracellular as were with and with in for cells were with or without for the The from and in cells was with a Flow levels of ATP were by the a from S. Biochem. PubMed Scopus Google Scholar). were with 20 for and with The cells were with for the were as by and W. J. Biochem. PubMed Scopus Google Scholar). of was with a with and of in mitochondria and were to the with a Y. Biochem. PubMed Scopus Google Scholar). and M15 cells were and mitochondria. and mitochondria with the were by the of a of for in the was converted to fluorescent The was by the of of in which and The for and the was by the of of and fluorescent were by The was The fluorescent were with and during a of of protein were with the protein with serum albumin as the from in which the of was or more are as The L-form of PHGPx contains a leader the S-form that green fluorescent protein were in RBL-2H3 cells in to the leader sequence of the L-form to target to the mitochondria of cells. fusion protein of with the leader sequence of from the of L-form The was a fusion protein of with from the of S-form that or were used to transfect RBL-2H3 cells by and the intracellular of due to was with a was in cells that or with were in cells that and mitochondria in cells were by the with and a of and The of due to was to that of mitochondrial of with the leader sequence of L-form mitochondria that the leader sequence the of mitochondrial PHGPx is the for to of to the mitochondria of RBL-2H3 cells. encoding and and were used to transfect RBL-2H3 cells. the for fluorescent of cells were under a RBL-2H3 cells that transfected with vector encoding were with and which is a The a of RBL-2H3 cells were transfected by with that theL-form and the S-form of PHGPx of that levels of PHGPx were M15 cells the L-form of PHGPx with the leader sequence and L9 cells the S-form of The control of cells transfected with the vector without an The of were with for for of the of PHGPx and The of PHGPx in L9 and M15 cells were and than that in S1 cells, in of and were detected and S1 levels of PHGPx and and of and in and M15 of of PHGPx and were by of in of were from of are of in a The of PHGPx and were by of in of were from of are of the of PHGPx and in and S1 cells. S1 cells, PHGPx was more in the mitochondria than in the cytosolic and A of PHGPx were in the and in L9 cells. The of PHGPx in the cytosolic from L9 cells was than that from S1 cells, the of PHGPx in the mitochondrial from L9 and S1 cells were The of PHGPx in the mitochondrial from M15 cells was that from S1 cells. The of L-form PHGPx caused the of the of PHGPx in mitochondria. of PHGPx in mitochondria of M15 cells was whereas in S1 and L9 were and The of cytosolic PHGPx in and M15 cells were and These results that the leader sequence of the L-form of PHGPx is the for transport to mitochondria, whereas the S-form PHGPx is in various The L-form of PHGPx can be to be the mitochondrial PHGPx and the S-form to be the non-mitochondrial of cells, was exclusively in the cytosolic and S1 cells, the of in the mitochondria was than that of changes of in and mitochondria were by the of PHGPx The of mitochondria in and S1 cells to injury was by cells to an of the chain (chemical hypoxia) The of S1 cells and L9 cells in a and and of cells to for A M15 cells were more resistant to cell death caused by KCN. The of for M15 cells was whereas for L9 and S1 cells was 20 These results that mitochondrial damage by be to by the of PHGPx in mitochondria. However, of non-mitochondrial PHGPx have such a of the of and M15 cells that of were to or the resistance to of M15 cells from of mitochondrial PHGPx sulfoximine an of the of the of such as and PHGPx, by the of glutathione in and mitochondria of cells. of glutathione in and mitochondria of S1 cells were and changes of glutathione were in the cells. The levels of glutathione were by the with of glutathione in and mitochondria of S1 cells to and protein by the of M15 cells, of glutathione in and mitochondria were and in the of glutathione by was in L9 cells the as that in M15 cells M15 cells with were exposed to the cells resistance to These results that resistance of M15 cells to is due to the of PHGPx in mitochondria. the effects of various that with mitochondrial function the of the of and carbonyl cyanide were used as an of mitochondrial complex as an of and as an of oxidative in rotenone a toxic L9 and S1 cells, whereas M15 cells were more resistant to cell death caused by the of M15 to mitochondrial injury due to or to was the as that of S1 and L9 cells These results that mitochondrial PHGPx to the of cells from cell death due to of the chain from death due to the direct effects membrane potential and the of PHGPx failed to protect cells from cell death that was caused by impairment of mitochondrial The effects of intracellular levels of in the were by the S1 cells, detected the generation of were produced in L9 cells to the and with the as in S1 cells However, the of was considerably suppressed in M15 cells as with S1 and L9 cells peroxidation of in which is a fluorescent was used as a of peroxidation in cells. A in the of of is an of peroxidation 1997; PubMed Scopus Google Scholar). of the that the as as the of of cells to KCN. from S1 and L9 cells was to of the with for no in from M15 cells was an that peroxidation was suppressed in M15 cells as with L9 cells. changes in mitochondrial membrane potential and in the integrity of plasma in cells, cytometric analysis with and a is by mitochondria, and is directly to mitochondrial is cells and to the integrity of plasma is that with were in the and and of S1 cells of S1 cells with for a of was in the and a was in the S1 cells membrane integrity to for and to the of the of L9 cells with were to be to of S1 cells. L9 cells from the to the to M15 cells mitochondrial membrane potential and in the the to for M15 cells mitochondrial membrane potential even long with These that mitochondrial PHGPx cells by loss of membrane potential and loss of membrane whereas non-mitochondrial PHGPx protect cells from the effects of KCN. in levels of ATP were in S1 and L9 cells of to with the The of ATP in M15 cells of with was than in S1 and L9 cells. The in levels of ATP to the loss of mitochondrial membrane potential in cells with of the intracellular levels of ATP in and M15 of with and M15 cells were with for the of ATP were by the are of results from in a and M15 cells were with for the of ATP were by the are of results from of to extracellular oxidative damage by of S1 cells and in a L9 cells were more resistant to the cytotoxic effects of than S1 cells, and M15 cells were even more M15 cells, with than of the of L9 cells was for the of PHGPx in cells were the M15 and L9 cells. Thus, of mitochondrial PHGPx was more in protecting cells from extracellular oxidative injury than that of non-mitochondrial in mitochondrial functions induced by were by cytometric analysis of S1 cells to for as cells in the cells in the and cells in the Thus, S1 cells mitochondrial membrane potential and plasma membrane and were in the with of plasma and the loss of mitochondrial potential were in L9 cells. L9 cells in the than S1 cells The membrane potential of M15 cells was and cells with a low membrane potential were than in the of L9 cells The of M15 cells in the was than in the of L9 and S1 cells. in mitochondria are synthesized in the as and are the mitochondria cleavage the The leader sequence of the to PHGPx is the for of protein the mitochondria by in M. H. N. Y. Biochem. 1996; PubMed Scopus Google Scholar). the the transport of PHGPx the mitochondria of cells. fluorescent protein as a in an to the of in cells. However, have used to the transport of mitochondria in cells. M. M. C. M. B. N. M. J. Biol. Chem. 1997; 272: Full Text Full Text PDF PubMed Scopus Google the of a protein that of and the of the of cells. a that protein to the leader sequence of PHGPx to the role of the leader sequence. was to the mitochondria, whereas which the leader was detected in mitochondria Thus, the leader sequence of PHGPx to be required as an as a are of glutathione as cytosolic PHGPx, plasma and Cell 1994; PubMed Scopus Google Scholar). PHGPx is in a leader sequence for transport to mitochondria. is in mitochondria is with a The leader sequence of PHGPx is for of of the for J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google that the for PHGPx transcription and that in of for that an that was in and was to the mitochondrial PHGPx The the and non-mitochondrial PHGPx which was synthesized in cells. RBL-2H3 cells, the to be used with resultant transcription of for mitochondrial PHGPx, since the of PHGPx in mitochondria was than that in The for of transcription from the in a for PHGPx to be A of PHGPx was in mitochondria RBL-2H3 cells were transfected with a encoding the L-form of PHGPx of PHGPx were in and of M15 cells as with S1 cells transfected can be to the of PHGPx in than mitochondria in M15 cells. is that for the S-form of PHGPx is from the as as from the the L-form of PHGPx is the of PHGPx might be by mitochondria can be The can be since the fusion protein that of with the was transported mitochondria The of the mitochondrial of PHGPx RBL-2H3 cells from cell death due to mitochondrial oxidative stress that from of cells to and rotenone (chemical S1 L9 cells were resistant to the of KCN. of M15 cells was the of PHGPx in cells was by of cytosolic and mitochondrial glutathione with buthionine sulfoximine Thus, of mitochondrial PHGPx to from mitochondrial mitochondrial PHGPx with the of an of complex of the mitochondrial various of damage to cells, the generation of ROS P. J. 1996; Google Scholar), the of mitochondrial S. Eguchi Y. Kamiike W. S. Y. Matsuda H. Tsujimoto Y. Oncogene. 1996; Google Scholar), a in levels of ATP S. Eguchi Y. Kamiike W. S. Y. Matsuda H. Tsujimoto Y. Oncogene. 1996; Google Scholar), and peroxidation G. Y. J. PubMed Scopus Google Scholar), for These in RBL-2H3 cells in a Flow cytometric analysis that induced the generation of in S1 cells peroxidation was induced the of loss of mitochondrial membrane potential and a in levels of intracellular ATP were from to and mitochondrial injury induced the loss of plasma membrane integrity cell death The of mitochondrial PHGPx cell death caused by KCN. Mitochondrial PHGPx the generation of which was an of cell Mitochondrial PHGPx failed to prevent cell death in to or of which directly the membrane potential and the of ATP without the of hydroperoxides. Thus, mitochondrial PHGPx to the functions of mitochondria by of intracellular generated as a of damage to the mitochondrial PHGPx in mitochondria the H2O2 generated in mitochondria that by to since the of peroxidation caused by H2O2 was in M15 cells. PHGPx reduces H2O2 than The results suggest that PHGPx in mitochondria might in of PHGPx in the might H2O2 that is in the M15 and L9 cells levels of to extracellular oxidative damage M15 cells were more resistant to the cytotoxic effects of than L9 cells even the of intracellular PHGPx was similar in of cells. These results suggest that mitochondria might be a primary target for Mitochondrial PHGPx cell death by protecting the mitochondrial Mitochondrial PHGPx direct injury of mitochondria by reduces the of by protecting mitochondrial of ROS in mitochondria in such as L. H. PubMed Scopus Google Scholar). have that protect mitochondria oxidative Mitochondrial is induced by which cell death the of levels of ROS in mitochondria C. Biochem. 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R. 1996; Full Text Full Text PDF PubMed Scopus Google Scholar), from the mitochondria to the H2O2 is a of the of from mitochondria, and the toxic effects of H2O2 that to cell death P. B. M.S. J. Biol. Chem. 1997; 272: PubMed Scopus Google Scholar). These results suggest that the generation of ROS in the mitochondria might be a in the of cell death and that mitochondria are to be of damage to cells A. 1997; PubMed Scopus Google Scholar). PHGPx is the and of mitochondria in the C. G. 1994; PubMed Scopus Google Scholar). The of levels of ROS in mitochondria by PHGPx might be with the of the cell apoptosis that is by to mitochondria. that ROS play an role as or in signaling such as the signaling A. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar), the protein Y. M. N.J. J. Biol. Chem. 1996; 271: Full Text Full Text PDF PubMed Scopus Google Scholar), and the of J. B. G. S. S. V. Biol. Chem. 1997; Google Scholar). ROS generated in mitochondria might be for the of NFκB C. A. A. N. Mol. 48: Google and of 20 which is to be an C.M. J. Biol. Chem. 1997; 272: Full Text Full Text PDF PubMed Scopus Google Scholar). R. B. S. M. R. Biochem. J. 1997; Scopus Google that the of NFκB by was in cells that overexpressed The that mitochondrial PHGPx might in the of that are by ROS in mitochondria. and for and for the of the and of the for in the cytometric