Heat-shock protein 70 attenuates nitric oxide-induced apoptosis in RAW macrophages by preventing cytochrome c release

2002 ◽  
Vol 362 (3) ◽  
pp. 635-641 ◽  
Author(s):  
Sabine D. KLEIN ◽  
Bernhard BRÜNE
Keyword(s):  
Nitric Oxide ◽  
Cell Cycle ◽  
Heat Shock ◽  
Cytochrome C ◽  
Heat Shock Protein ◽  
Cytochrome C Release ◽  
Interacting Protein ◽  
P53 Expression ◽  
Induced Apoptosis ◽  
Hoechst Staining

Heat-shock protein (Hsp) 70 is an inhibitor of apoptosis and has been shown to protect against nitric oxide-mediated toxicity. To gain mechanistic insights into the actions of Hsp70, we stably transfected RAW 264.7 mouse macrophages with the human Hsp70 gene and investigated critical steps in the progression towards cell demise. Incubation of control and Hsp70-transfected macrophages with S-nitrosoglutathione induced accumulation of the tumour suppressor p53, expression of p21WAF1/CIP1 (where WAF1 corresponds to wild-type p53-activated fragment 1 and CIP1 corresponds to cyclin-dependent kinase-interacting protein 1) and G1 cell-cycle arrest. However, cytochrome c translocation to the cytosol and activation of caspase 9 and caspase 3 were markedly reduced in Hsp70-overexpressing cells. In addition, changes in nuclear morphology, as determined by Hoechst staining, and the appearance of cells in the sub-G1 phase were diminished in Hsp70-overexpressing cells compared with controls. We conclude that, in macrophages, Hsp70 interferes with cytochrome c release from mitochondria and, thereby, prevents nitric oxide-induced apoptosis, but leaves p53 accumulation and interference in the cell cycle intact.

Nitric Oxide–Induced Apoptosis in Human Leukemic Lines Requires Mitochondrial Lipid Degradation and Cytochrome C Release

Blood ◽  
1999 ◽  
Vol 93 (7) ◽  
pp. 2342-2352 ◽  
Author(s):  
Alexey Ushmorov ◽  
Frank Ratter ◽  
Volker Lehmann ◽  
Wulf Dröge ◽  
Volker Schirrmacher ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Cytochrome C ◽  
Mitochondrial Protein ◽  
Jurkat Cells ◽  
Leukemic Cells ◽  
Human Leukemia ◽  
Cytochrome C Release ◽  
Mitochondrial Functions ◽  
Mitochondrial Lipid ◽  
Induced Apoptosis

Abstract We have previously shown that nitric oxide (NO) stimulates apoptosis in different human neoplastic lymphoid cell lines through activation of caspases not only via CD95/CD95L interaction, but also independently of such death receptors. Here we investigated mitochondria-dependent mechanisms of NO-induced apoptosis in Jurkat leukemic cells. NO donor glycerol trinitrate (at the concentration, which induces apoptotic cell death) caused (1) a significant decrease in the concentration of cardiolipin, a major mitochondrial lipid; (2) a downregulation in respiratory chain complex activities; (3) a release of the mitochondrial protein cytochrome c into the cytosol; and (4) an activation of caspase-9 and caspase-3. These changes were accompanied by an increase in the number of cells with low mitochondrial transmembrane potential and with a high level of reactive oxygen species production. Higher resistance of the CD95-resistant Jurkat subclone (APO-R) cells to NO-mediated apoptosis correlated with the absence of cytochrome c release and with less alterations in other mitochondrial parameters. An inhibitor of lipid peroxidation, trolox, significantly suppressed NO-mediated apoptosis in APO-S Jurkat cells, whereas bongkrekic acid (BA), which blocks mitochondrial permeability transition, provided only a moderate antiapoptotic effect. Transfection of Jurkat cells with bcl-2 led to a complete block of apoptosis due to the prevention of changes in mitochondrial functions. We suggest that the mitochondrial damage (in particular, cardiolipin degradation and cytochrome c release) induced by NO in human leukemia cells plays a crucial role in the subsequent activation of caspase and apoptosis.

scholarly journals Overexpression of Rat Heat Shock Protein 70 is Associated with Reduction of Early Mitochondrial Cytochrome c Release and Subsequent DNA Fragmentation after Permanent Focal Ischemia

2003 ◽  
Vol 23 (6) ◽  
pp. 718-727 ◽  
Author(s):  
Daisuke Tsuchiya ◽  
Shwuhuey Hong ◽  
Yasuhiko Matsumori ◽  
Hiroaki Shiina ◽  
Takamasa Kayama ◽  
...  
Keyword(s):  
Heat Shock ◽  
Cytochrome C ◽  
Heat Shock Protein ◽  
Dna Fragmentation ◽  
Heat Shock Protein 70 ◽  
Focal Ischemia ◽  
Mitochondrial Cytochrome ◽  
Cytochrome C Release ◽  
Permanent Focal Ischemia ◽  
Mitochondrial Cytochrome C

Although protective effects of heat shock protein 70 (HSP70) overproduction after ischemic injury have been shown both in vitro and in vivo in neurons, the mechanisms are not fully understood. The hypothesis of this study is that transgenic mice overexpressing HSP70 (HSP70 Tg) show reduced mitochondrial cytochrome c release into cytosol and diminished apoptotic cell death after permanent focal ischemia in comparison to wild-type (Wt) mice. Permanent middle cerebral artery occlusion (pMCAO) was produced by intraluminal suture cannulation in HSP70 Tg and Wt mice. DNA fragmentation was evaluated with DNA gel electrophoresis and terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick end labeling (TUNEL) 24 h after pMCAO. Mitochondrial cytochrome c release into cytosol was assessed with Western blotting and immunohistochemistry 4 h after pMCAO. Cytochrome c levels in the cytosolic fraction were significantly reduced and immunoreactivity of cytochrome c in both cortex and striatum was significantly less in HSP70 Tg mice compared with Wt mice after 4-h pMCAO. DNA laddering, which was clearly observed in Wt mice, was markedly attenuated in HSP70 Tg mice 24 h after pMCAO. The number of TUNEL-positive cells was significantly reduced in HSP70 Tg mice compared with Wt mice. Results are consistent with an association between overexpression of HSP70 and reduction of cytochrome c release with subsequent DNA fragmentation. This may contribute to the HSP70-mediated neuroprotective effect observed after cerebral ischemia.

scholarly journals HEAT SHOCK PROTEIN 70 (HSP70) BLOCKS NITRIC OXIDE-INDUCED APOPTOSIS

1997 ◽  
Vol 75 ◽  
pp. 96
Author(s):  
Hun-Taeg Chung ◽  
Hyun-Jeong Kwak ◽  
Chang-Duk Jun ◽  
Hyun-Ock Pae ◽  
Ji-Chang Yu ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Heat Shock Protein 70 ◽  
Induced Apoptosis

Nitric Oxide–Induced Apoptosis in Human Leukemic Lines Requires Mitochondrial Lipid Degradation and Cytochrome C Release

Blood ◽  
1999 ◽  
Vol 93 (7) ◽  
pp. 2342-2352 ◽  
Author(s):  
Alexey Ushmorov ◽  
Frank Ratter ◽  
Volker Lehmann ◽  
Wulf Dröge ◽  
Volker Schirrmacher ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Cytochrome C ◽  
Mitochondrial Protein ◽  
Jurkat Cells ◽  
Leukemic Cells ◽  
Human Leukemia ◽  
Cytochrome C Release ◽  
Mitochondrial Functions ◽  
Mitochondrial Lipid ◽  
Induced Apoptosis

We have previously shown that nitric oxide (NO) stimulates apoptosis in different human neoplastic lymphoid cell lines through activation of caspases not only via CD95/CD95L interaction, but also independently of such death receptors. Here we investigated mitochondria-dependent mechanisms of NO-induced apoptosis in Jurkat leukemic cells. NO donor glycerol trinitrate (at the concentration, which induces apoptotic cell death) caused (1) a significant decrease in the concentration of cardiolipin, a major mitochondrial lipid; (2) a downregulation in respiratory chain complex activities; (3) a release of the mitochondrial protein cytochrome c into the cytosol; and (4) an activation of caspase-9 and caspase-3. These changes were accompanied by an increase in the number of cells with low mitochondrial transmembrane potential and with a high level of reactive oxygen species production. Higher resistance of the CD95-resistant Jurkat subclone (APO-R) cells to NO-mediated apoptosis correlated with the absence of cytochrome c release and with less alterations in other mitochondrial parameters. An inhibitor of lipid peroxidation, trolox, significantly suppressed NO-mediated apoptosis in APO-S Jurkat cells, whereas bongkrekic acid (BA), which blocks mitochondrial permeability transition, provided only a moderate antiapoptotic effect. Transfection of Jurkat cells with bcl-2 led to a complete block of apoptosis due to the prevention of changes in mitochondrial functions. We suggest that the mitochondrial damage (in particular, cardiolipin degradation and cytochrome c release) induced by NO in human leukemia cells plays a crucial role in the subsequent activation of caspase and apoptosis.

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