scholarly journals Altered proteasomal function due to the expression of polyglutamine-expanded truncated N-terminal huntingtin induces apoptosis by caspase activation through mitochondrial cytochrome c release

2001 ◽  
Vol 10 (10) ◽  
pp. 1049-1059 ◽  
Author(s):  
N. R. Jana
Keyword(s):  
Cytochrome C ◽  
Mitochondrial Cytochrome ◽  
Caspase Activation ◽  
Cytochrome C Release ◽  
Mitochondrial Cytochrome C

Cytochrome c release into cytosol with subsequent caspase activation during warm ischemia in rat liver

2001 ◽  
Vol 281 (4) ◽  
pp. G1115-G1123 ◽  
Author(s):  
Junpei Soeda ◽  
Shinichi Miyagawa ◽  
Kenji Sano ◽  
Junya Masumoto ◽  
Shun'Ichiro Taniguchi ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Dna Fragmentation ◽  
Warm Ischemia ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Dependent Manner ◽  
Mitochondrial Cytochrome ◽  
Caspase Activation ◽  
Cytochrome C Release ◽  
Apoptotic Pathway ◽  
Mitochondrial Cytochrome C

Apoptosis plays an important role in liver ischemia and reperfusion (I/R) injury. However, the molecular basis of apoptosis in I/R injury is poorly understood. The aims of this study were to ascertain when and how apoptotic signal transduction occurs in I/R injury. The apoptotic pathway in rats undergoing 90 min of warm ischemia with reperfusion was compared with that of rats undergoing prolonged ischemia alone. During ischemia, mitochondrial cytochrome c was released into the cytosol in a time-dependent manner in hepatocytes and sinusoidal endothelial cells, and caspase-3 and an inhibitor of caspase-activated DNase were cleaved. However, apoptotic manifestation and DNA fragmentation were not observed. After reperfusion, nuclear condensation, cells positive for terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling, and DNA fragmentation were observed and caspase-8 and Bid cleavage occurred. In contrast, prolonged ischemia alone induced necrosis rather than apoptosis. In summary, our results show that release of mitochondrial cytochrome c and caspase activation proceed during ischemia, although apoptosis is manifested after reperfusion.

scholarly journals Bcr-Abl-Mediated Protection from Apoptosis Downstream of Mitochondrial Cytochrome c Release

2004 ◽  
Vol 24 (23) ◽  
pp. 10289-10299 ◽  
Author(s):  
Paula B. Deming ◽  
Zachary T. Schafer ◽  
Jessica S. Tashker ◽  
Malia B. Potts ◽  
Mohanish Deshmukh ◽  
...  
Keyword(s):  
Cell Death ◽  
Cytochrome C ◽  
Mitochondrial Cytochrome ◽  
Caspase Activation ◽  
Caspase 9 ◽  
Cytochrome C Release ◽  
Intact Cells ◽  
Caspase Recruitment Domain ◽  
Distinct Mechanism ◽  
Mitochondrial Cytochrome C

ABSTRACT Bcr-Abl, activated in chronic myelogenous leukemias, is a potent cell death inhibitor. Previous reports have shown that Bcr-Abl prevents apoptosis through inhibition of mitochondrial cytochrome c release. We report here that Bcr-Abl also inhibits caspase activation after the release of cytochrome c. Bcr-Abl inhibited caspase activation by cytochrome c added to cell-free lysates and prevented apoptosis when cytochrome c was microinjected into intact cells. Bcr-Abl acted posttranslationally to prevent the cytochrome c-induced binding of Apaf-1 to procaspase 9. Although Bcr-Abl prevented interaction of endogenous Apaf-1 with the recombinant prodomain of caspase 9, it did not affect the association of endogenous caspase 9 with the isolated Apaf-1 caspase recruitment domain (CARD) or Apaf-1 lacking WD-40 repeats. These data suggest that Apaf-1 recruitment of caspase 9 is faulty in the presence of Bcr-Abl and that cytochrome c/dATP-induced exposure of the Apaf-1 CARD is likely defective. These data provide a novel locus of Bcr-Abl antiapoptotic action and suggest a distinct mechanism of apoptosomal inhibition.

scholarly journals Reperfusion, not simulated ischemia, initiates intrinsic apoptosis injury in chick cardiomyocytes

2003 ◽  
Vol 284 (1) ◽  
pp. H141-H150 ◽  
Author(s):  
Terry L. Vanden Hoek ◽  
Yimin Qin ◽  
Kim Wojcik ◽  
Chang-Qing Li ◽  
Zuo-Hui Shao ◽  
...  
Keyword(s):  
Cell Death ◽  
Cytochrome C ◽  
Ischemia Reperfusion ◽  
Mitochondrial Cytochrome ◽  
Caspase Activation ◽  
Cytochrome C Release ◽  
Nuclear Condensation ◽  
Simulated Ischemia ◽  
Fluoromethyl Ketone ◽  
Mitochondrial Cytochrome C

Although ischemia-reperfusion (I/R) can initiate apoptosis, the timing and contribution of the mitochondrial/cytochrome c apoptosis death pathway to I/R injury is unclear. We studied the timing of cytochrome c release during I/R and whether subsequent caspase activation contributes to reperfusion injury in confluent chick cardiomyocytes. One-hour simulated ischemia followed by 3-h reperfusion resulted in significant cell death, with most cell death evident during the reperfusion phase and demonstrating mitochondrial cytochrome c release within 5 min after reperfusion. By contrast, cells exposed to prolonged ischemia for 4 h had only marginally increased cell death and no detectable cytochrome c release into the cytosol. Caspase activation could not be detected after ischemia only, but it significantly increased after reperfusion. Caspase inhibitors benzyloxycarbonyl-Val-Ala-Asp-fluoromethyl ketone, Ac-Asp-Gln-Thr-Asp-H, or benzyloxycarbonyl-Leu-Glu (Ome)-His-Asp-(Ome)-fluoromethyl ketone given only at reperfusion significantly attenuated cell death and resulted in return of contraction. Antixoxidants decreased cytochrome c release, nuclear condensation, and cell death. These results suggest that reperfusion oxidants initiate cytochrome c release within minutes, and apoptosis within hours, significant enough to increase cell death and contractile dysfunction.

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