scholarly journals Apoptosis of Growth Plate Chondrocytes Occurs through a Mitochondrial Pathway

2007 ◽  
Vol 77 (1) ◽  
pp. 129-134 ◽  
Author(s):  
Cristina C. Teixeira ◽  
Aida P. Padron Costas ◽  
Yelena Nemelivsky
Keyword(s):  
Cytochrome C ◽  
Growth Plate ◽  
Caspase 3 ◽  
Mitochondrial Pathway ◽  
Chondrocyte Apoptosis ◽  
Cytochrome C Release ◽  
Growth Plate Chondrocytes ◽  
Chondrocyte Viability ◽  
Induced Apoptosis ◽  
Free Media

Abstract Objective: To determine the role of mitochondria in chondrocyte apoptosis induced by inorganic phosphate (Pi). Materials and Methods: Chondrocytes isolated from the growth plates of chick embryo tibia were treated with Pi in serum-free media; chondrocyte viability, mitochondrial membrane potential, cytochrome c release from mitochondria, caspase 3 activity, endonuclease activity, and DNA fragmentation were investigated. Results: Exposure to Pi for 24 hours induced apoptosis in growth plate chondrocytes through a pathway that involved loss of mitochondrial function, release of cytochrome c into the cytoplasm, increases in caspase 3 and endonuclease activities, and fragmentation of DNA. Conclusions: This study suggests that mitochondria are important players in Pi-induced apoptosis.

scholarly journals Cisplatin-induced apoptosis in p53-deficient renal cells via the intrinsic mitochondrial pathway

2009 ◽  
Vol 296 (5) ◽  
pp. F983-F993 ◽  
Author(s):  
Man Jiang ◽  
Cong-Yi Wang ◽  
Shuang Huang ◽  
Tianxin Yang ◽  
Zheng Dong
Keyword(s):  
Cytochrome C ◽  
Primary Cultures ◽  
Mitochondrial Pathway ◽  
Limiting Factor ◽  
Double Knockout ◽  
Cytochrome C Release ◽  
Renal Tubular Cells ◽  
In The Wild ◽  
Renal Tubular ◽  
Induced Apoptosis

Nephrotoxicity is the major limiting factor for the use of cisplatin in cancer therapy. Recent studies have demonstrated an important role for p53 in cisplatin-induced renal injury. Nevertheless, pharmacological and genetic blockade of p53 only provides partial renoprotective effects, suggesting the presence of p53-independent injury mechanisms. To understand the p53-independent mechanisms, we have now examined cisplatin-induced apoptosis in p53-deficient kidney cells. We show that cisplatin could induce Bax activation, cytochrome c release, and apoptosis in primary cultures of p53-deficient renal tubular cells, albeit at a level that was lower than in the wild-type cells. Cisplatin could also induce typical apoptosis in p53-deficient baby mouse kidney (BMK) cells. The apoptosis was caspase dependent and could be completely blocked by general caspase inhibitors. Bax and Bak, two key molecules in the mitochondrial pathway of apoptosis, were interdependently activated by cisplatin, with Bax translocation to and Bax/Bak oligomerization in mitochondria, leading to cytochrome c release. Importantly, cytochrome c release and apoptosis were diminished in Bax/Bak single or double-knockout BMK cells. Furthermore, overexpression of Bcl-2 could ameliorate cisplatin-induced cytochrome c release and apoptosis. Together, the results have demonstrated a p53-independent mechanism of cisplatin nephrotoxicity that involves the mitochondrial pathway of apoptosis.

scholarly journals Polyamine depletion prevents camptothecin-induced apoptosis by inhibiting the release of cytochromec

2002 ◽  
Vol 282 (6) ◽  
pp. C1290-C1297 ◽  
Author(s):  
Qing Yuan ◽  
Ramesh M. Ray ◽  
Leonard R. Johnson
Keyword(s):  
Cytochrome C ◽  
Mammalian Cells ◽  
Caspase 3 ◽  
Intestinal Epithelial ◽  
Caspase 9 ◽  
Cytochrome C Release ◽  
Polyamine Synthesis ◽  
Antiapoptotic Proteins ◽  
Induced Apoptosis ◽  
Rate Limiting

C1297, 2002; 10.1152/ajpcell.00351.2001.We have shown previously that depletion of polyamines delays apoptosis induced by camptothecin in rat intestinal epithelial cells (IEC-6). Mitochondria play an important role in the regulation of apoptosis in mammalian cells because apoptotic signals induce mitochondria to release cytochrome c. The latter interacts with Apaf-1 to activate caspase-9, which in turn activates downstream caspase-3. Bcl-2 family proteins are involved in the regulation of cytochrome c release from mitochondria. In this study, we examined the effects of polyamine depletion on the activation of the caspase cascade, release of cytochrome cfrom mitochondria, and expression and translocation of Bcl-2 family proteins. We inhibited ornithine decarboxylase, the first rate-limiting enzyme in polyamine synthesis, with α-difluoromethylornithine (DFMO) to deplete cells of polyamines. Depletion of polyamines prevented camptothecin-induced release of cytochrome c from mitochondria and decreased the activity of caspase-9 and caspase-3. The mitochondrial membrane potential was not disrupted when cytochrome c was released. Depletion of polyamines decreased translocation of Bax to mitochondria during apoptosis. The expression of antiapoptotic proteins Bcl-xL and Bcl-2 was increased in DFMO-treated cells. Caspase-8 activity and cleavage of Bid were decreased in cells depleted of polyamines. These results suggest that polyamine depletion prevents IEC-6 cells from apoptosis by preventing the translocation of Bax to mitochondria, thus preventing the release of cytochrome c.

Polyamines are required for activation of c-Jun NH2-terminal kinase and apoptosis in response to TNF-α in IEC-6 cells

2003 ◽  
Vol 285 (5) ◽  
pp. G980-G991 ◽  
Author(s):  
Sujoy Bhattacharya ◽  
Ramesh M. Ray ◽  
Mary Jane Viar ◽  
Leonard R. Johnson
Keyword(s):  
Cytochrome C ◽  
Dna Fragmentation ◽  
Caspase 3 ◽  
Specific Inhibitor ◽  
Cell Types ◽  
Caspase 9 ◽  
Cytochrome C Release ◽  
Tnf Α ◽  
Induced Apoptosis ◽  
Jnk Activation

Intracellular polyamine homeostasis is important for the regulation of cell proliferation and apoptosis and is necessary for the balanced growth of cells and tissues. Polyamines have been shown to play a role in the regulation of apoptosis in many cell types, including IEC-6 cells, but the mechanism is not clear. In this study, we analyzed the mechanism by which polyamines regulate the process of apoptosis in response to tumor necrosis factor-α (TNF-α). TNF-α or cycloheximide (CHX) alone did not induce apoptosis in IEC-6 cells. Significant apoptosis was observed when CHX was given along with TNF-α, as indicated by a significant increase in the detachment of cells, caspase-3 activity, and DNA fragmentation. Polyamine depletion by treatment with α-difluoromethylornithine significantly reduced the level of apoptosis, as judged by DNA fragmentation and the caspase-3 activity of attached cells. Apoptosis in IEC-6 cells was accompanied by the activation of upstream caspases-6, -8, and -9 and NH2-terminal c-Jun kinase (JNK). Inhibition of JNK activation prevented caspase-9 activation. Polyamine depletion prevented the activation of JNK and of caspases-6, -8, -9, and -3. SP-600125, a specific inhibitor of JNK activation, prevented cytochrome c release from mitochondria, JNK activation, DNA fragmentation, and caspase-9 activation in response to TNF-α/CHX. In conclusion, we have shown that polyamine depletion delays and decreases TNF-α-induced apoptosis in IEC-6 cells and that apoptosis is accompanied by the release of cytochrome c, the activation of JNK, and of upstream caspases as well as caspase-3. Polyamine depletion prevented JNK activation, which may confer protection against apoptosis by modulation of upstream caspase-9 activation.

scholarly journals Rhein ElicitsIn VitroCytotoxicity in Primary Human Liver HL-7702 Cells by Inducing Apoptosis through Mitochondria-Mediated Pathway

2015 ◽  
Vol 2015 ◽  
pp. 1-19 ◽  
Author(s):  
Guy-Armel Bounda ◽  
Wang Zhou ◽  
Dan-dan Wang ◽  
Feng Yu
Keyword(s):  
Cytochrome C ◽  
Molecular Mechanisms ◽  
Caspase 3 ◽  
Morphological Changes ◽  
Fatty Degeneration ◽  
Apoptotic Cells ◽  
Dependent Manner ◽  
Caspase 9 ◽  
Cytochrome C Release ◽  
Induced Apoptosis

Objective. To study rhein-induced apoptosis signaling pathway and to investigate its molecular mechanisms in primary human hepatic cells.Results. Cell viability of HL-7702 cells treated with rhein showed significant decrease in dose-dependent manner. Following rhein treatment (25 μM, 50 μM, and 100 μM) for 12 h, the detection of apoptotic cells was significantly analyzed by flow cytometry and nuclear morphological changes by Hoechst 33258, respectively. Fatty degeneration studies showed upregulation level of the relevant hepatic markers (P< 0.01). Caspase activities expressed significant upregulation of caspase-3, caspase-9, and caspase-8. Moreover, apoptotic cells by rhein were significantly inhibited by Z-LEHD-FMK and Z-DEVD-FMK, caspase-9 inhibitor, and caspase-3 inhibitor, respectively. Overproduction of reactive oxygen species, lipid peroxidation, and loss of mitochondrial membrane potential were detected by fluorometry. Additionally, NAC, a ROS scavenger, significantly attenuated rhein-induced oxidative damage in HL-7702 cells. Furthermore, real-time qPCR results showed significant upregulation of p53, PUMA, Apaf-1, and Casp-9 and Casp-3 mRNA, with no significant changes of Fas and Cytochrome-c. Immunoblotting revealed significant Cytochrome-c release from mitochondria into cytosol and no change in Fas expression.Conclusion. Taken together, these observations suggested that rhein could induce apoptosis in HL-7702 cells via mitochondria-mediated signal pathway with involvement of oxidative stress mechanism.

Inhibition of hypoxia/reoxygenation-induced apoptosis in metallothionein-overexpressing cardiomyocytes

2001 ◽  
Vol 280 (5) ◽  
pp. H2292-H2299 ◽  
Author(s):  
Guang-Wu Wang ◽  
Zhanxiang Zhou ◽  
Jon B. Klein ◽  
Y. James Kang
Keyword(s):  
Cytochrome C ◽  
Caspase 3 ◽  
Ischemia Reperfusion ◽  
Annexin V ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Cytochrome C Release ◽  
Apoptotic Pathway ◽  
Fetal Bovine ◽  
Induced Apoptosis ◽  
Hypoxia Reoxygenation

To study possible mechanisms for metallothionein (MT) inhibition of ischemia-reperfusion-induced myocardial injury, cardiomyocytes isolated from MT-overexpressing transgenic neonatal mouse hearts and nontransgenic controls were subjected to 4 h of hypoxia (5% CO2-95% N2, glucose-free modified Tyrode's solution) followed by 1 h of reoxygenation in MEM + 20% fetal bovine serum (FBS) (5% CO2-95% air), and cytochrome c-mediated caspase-3 activation apoptotic pathway was determined. Hypoxia/reoxygenation-induced apoptosis was significantly suppressed in MT-overexpressing cardiomyocytes, as measured by both terminal deoxynucleotidyl transferase-mediated deoxyuridine 5-triphosphate nick-end labeling and annexin V-FITC binding. In association with apoptosis, mitochondrial cytochrome c release, as determined by Western blot, was observed to occur in nontransgenic cardiomyocytes. Correspondingly, caspase-3 was activated as determined by laser confocal microscopic examination with the use of FITC-conjugated antibody against active caspase-3 and by enzymatic assay. The activation of this apoptotic pathway was significantly inhibited in MT-overexpressing cells, as evidenced by both suppression of cytochrome c release and inhibition of caspase-3 activation. The results demonstrate that MT suppresses hypoxia/reoxygenation-induced cardiomyocyte apoptosis through, at least in part, inhibition of cytochrome c-mediated caspase-3 activation.

scholarly journals The influence of melatonin on apoptosis of human neutrophils

2019 ◽  
Vol 73 ◽  
pp. 81-91
Author(s):  
Sylwia Mańka ◽  
Zbigniew Baj ◽  
Ewa Majewska
Keyword(s):  
Cytochrome C ◽  
Caspase 3 ◽  
Control Level ◽  
Human Neutrophils ◽  
Ros Generation ◽  
Main Role ◽  
Spontaneous Apoptosis ◽  
Cytochrome C Release ◽  
Tnf Α ◽  
Induced Apoptosis

Aim: Melatonin (Mel) besides its main role in circadian and seasonal rhythm coordination, plays a role in immunoregulation and inflammatory responses. The melatonin’s ability to modulate apoptosis is one of its important roles related to its effect on immune system but the exact effect of its action and the mechanisms of apoptosis control by melatonin remain still unclear. The goal of our study was to examine the involvement of melatonin in the apoptosis of human neutrophils in vitro and possible mechanisms of this action. Material/Methods: We measured the effect of melatonin on the spontaneous and TNF-α-induced apoptosis of human neutrophils using propidium iodide and Annexin-V and on caspase-3 activation, apoptosis-related surface antigen expressions, intracellular reactive oxygen species (ROS) generation and cytochrome c release using flow cytometry and commercial reagents. Results: Melatonin does not affect spontaneous apoptosis of human neutrophils and mitochondrial cytochrome c release but protects the cells from the significant rise of TNF-α-induced apoptosis and cytochrome c release. Intracellular ROS generation in PMA-stimulated neutrophils did not change after the influence of melatonin but the significant drop of ROS generation in neutrophils stimulated with TNF- α was upregulated to the control level after preincubation of the neutrophils with melatonin. Melatonin did not change significantly Fas, Fas-L and active caspase-3 expressions in neutrophils. Conclusions: Melatonin does not affect the spontaneous apoptosis, however, inhibits TNF-α-induced apoptosis of human neutrophils. Our findings suggest that the intrinsic pathway of the process is a result of the melatonin induced mitochondrial alterations.

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