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.

LPA protects intestinal epithelial cells from apoptosis by inhibiting the mitochondrial pathway

2003 ◽  
Vol 284 (5) ◽  
pp. G821-G829 ◽  
Author(s):  
Wenlin Deng ◽  
De-An Wang ◽  
Elvira Gosmanova ◽  
Leonard R. Johnson ◽  
Gabor Tigyi
Keyword(s):  
Epithelial Cells ◽  
Cytochrome C ◽  
Protein Expression ◽  
Caspase 3 ◽  
Intestinal Epithelial Cells ◽  
Intestinal Epithelial ◽  
Caspase 9 ◽  
Cytochrome C Release ◽  
Apoptotic Pathway ◽  
Antiapoptotic Activity

We previously showed ( Gastroenterology 123: 206–216, 2002) that lysophosphatidic acid (LPA) protects and rescues rat intestinal epithelial cells (IEC-6) from apoptosis. Here, we provide evidence for the LPA-elicited inhibition of the mitochondrial apoptotic pathway leading to attenuation of caspase-3 activation. Pretreatment of IEC-6 cells with LPA inhibited campothecin-induced caspase-9 and caspase-3 activation and DNA fragmentation. A caspase-9 inhibitor peptide mimicked the LPA-elicited antiapoptotic activity. LPA elicited ERK1/ERK2 and PKB/Akt phosphorylation. The LPA-elicited antiapoptotic activity and inhibition of caspase-9 activity were abrogated by pertussis toxin, PD 98059, wortmannin, and LY 294002. LPA reduced cytochrome c release from mitochondria and prevented activation of caspase-9. LPA prevented translocation of Bax from cytosol to mitochondria and increased the expression of the antiapoptotic Bcl-2 mRNA and protein. LPA had no effect on Bcl-xl, Bad, and Bak mRNA or protein expression. These data indicate that LPA protects IEC-6 cells from camptothecin-induced apoptosis through Gi-coupled inhibition of caspase-3 activation mediated by the attenuation of caspase-9 activation due to diminished cytochrome c release, involving upregulation of Bcl-2 protein expression and prevention of Bax translocation.

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.

Dexamethasone-induced apoptosis of thymocytes: role of glucocorticoid receptor–associated Src kinase and caspase-8 activation

Blood ◽  
2003 ◽  
Vol 101 (2) ◽  
pp. 585-593 ◽  
Author(s):  
Maria Cristina Marchetti ◽  
Barbara Di Marco ◽  
Grazia Cifone ◽  
Graziella Migliorati ◽  
Carlo Riccardi
Keyword(s):  
Cytochrome C ◽  
Glucocorticoid Receptor ◽  
Caspase 3 ◽  
Kinase Inhibitor ◽  
Src Kinase ◽  
Caspase 8 ◽  
Caspase 9 ◽  
Cytochrome C Release ◽  
Sequence Of Events ◽  
Induced Apoptosis

Glucocorticoid hormones (GCHs) regulate normal and neoplastic lymphocyte development by exerting antiproliferative and/or apoptotic effects. We have previously shown that dexamethasone (DEX)–activated thymocyte apoptosis requires a sequence of events including interaction with the glucocorticoid receptor (GR), phosphatidylinositol-specific phospholipase C (PI-PLC), and acidic sphingomyelinase (aSMase) activation. We analyzed the mechanisms of GCH-activated apoptosis by focusing on GR-associated Src kinase, cytochrome c release, and caspase-8, -9, and -3 activation. We show here that PI-PLC binds to GR-associated Src kinase, as indicated by coimmunoprecipitation experiments. Moreover, DEX treatment induces PI-PLC phosphorylation and activation. DEX-induced PI-PLC phosphorylation, activation, and apoptosis are inhibited by PP1, a Src kinase inhibitor, thus suggesting that Src-mediated PI-PLC activation is involved in DEX-induced apoptosis. Caspase-9, -8, and -3 activation and cytochrome c release can be detected 1 to 2 hours after DEX treatment. Caspase-9 inhibition does not counter cytochrome crelease, caspase-8 and caspase-3 activation, and apoptosis. Caspase-8 inhibition counters cytochrome c release, caspase-9 and caspase-3 activation, and apoptosis, thus suggesting that caspase-8 inhibitor can directly inhibit caspase-9 and/or that DEX-induced caspase-8 activation is upstream to mitochondria and can regulate caspase-3 directly or through cytochrome c release and the consequent caspase-9/caspase-3 activation. DEX-induced caspase-8 activation, like ceramide-induced caspase-8 activation, correlates with the formation of Fas-associated death domain protein (FADD)/caspase-8 complex. Caspase-8 activation is countered by the inhibition of macromolecular synthesis and of Src kinase, PI-PLC, and aSMase activation, suggesting it is downstream in the DEX-activated apoptotic pathway of thymocytes.

Identification of apoptotic genes mediating TGF-β/Smad3-induced cell death in intestinal epithelial cells using a genomic approach

2007 ◽  
Vol 292 (1) ◽  
pp. G28-G38 ◽  
Author(s):  
Yanna Cao ◽  
Lu Chen ◽  
Weili Zhang ◽  
Yan Liu ◽  
Harry T. Papaconstantinou ◽  
...  
Keyword(s):  
Caspase 3 ◽  
Target Genes ◽  
Transforming Growth Factor ◽  
Intestinal Epithelial ◽  
Cytochrome C Release ◽  
Apoptotic Pathway ◽  
Genomic Approach ◽  
Apoptotic Genes ◽  
Induced Apoptosis

Transforming growth factor (TGF)-β-dependent apoptosis is important in the elimination of damaged or abnormal cells from normal tissues in vivo. Previously, we have shown that TGF-β inhibits the growth of rat intestinal epithelial (RIE)-1 cells. However, RIE-1 cells are relatively resistant to TGF-β-induced apoptosis due to a low endogenous Smad3-to-Akt ratio. Overexpression of Smad3 sensitizes RIE-1 cells (RIE-1/Smad3) to TGF-β-induced apoptosis by altering the Smad3-to-Akt ratio in favor of apoptosis. In this study, we utilized a genomic approach to identify potential downstream target genes that are regulated by TGF-β/Smad3. Total RNA samples were analyzed using Affymetrix oligonucleotide microarrays. We found that TGF-β regulated 518 probe sets corresponding to its target genes. Interestingly, among the known apoptotic genes included in the microarray analyses, only caspase-3 was induced, which was confirmed by real-time RT-PCR. Furthermore, TGF-β activated caspase-3 through protein cleavage. Upstream of caspase-3, TGF-β induced mitochondrial depolarization, cytochrome c release, and cleavage of caspase-9, which suggests that the intrinsic apoptotic pathway mediates TGF-β-induced apoptosis in RIE-1/Smad3 cells.

JS-K, a Novel Nitric Oxide (NO) Generator, Induces Cytochrome c Release and Caspase Activation in HL-60 Myeloid Leukemia Cells.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3415-3415
Author(s):  
Paul J. Shami ◽  
Vidya Udupi ◽  
Margaret Yu ◽  
Swati Malaviya ◽  
Joseph E. Saavedra ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Caspase 3 ◽  
Myelogenous Leukemia ◽  
Leukemia Cells ◽  
Caspase 8 ◽  
Caspase 9 ◽  
Cytochrome C Release ◽  
Dose Dependent Fashion ◽  
Acute Myelogenous ◽  
Dose Dependent

Abstract NO induces differentiation and apoptosis in Acute Myelogenous Leukemia (AML) cells. Glutathione S-Transferases (GST) play an important role in multidrug resistance and are upregulated in 90% of AML cells. We have designed a novel prodrug class that releases NO on metabolism by GST. O2-(2,4-Dinitrophenyl) 1-[(4-ethoxycarbonyl)piperazin-1-yl]diazen-1-ium-1,2-diolate (JS-K, a member of this class) has potent antileukemic activity. We have previously shown that JS-K induces apoptosis in HL-60 cells by a caspase dependent mechanism (Molecular Cancer Therapeutics2:409-417,2003). The purpose of this study was to determine the pathway through which JS-K induces apoptosis. Western blot analysis showed that treatment of HL-60 cells with JS-K (0 – 1 μM) for 6 hours results in release of Cytochrome c from mitochondria in a dose dependent fashion. Treatment with JS-K resulted in a dose dependent activation of Caspase 9. Sixteen and 24 hours after exposure to 1 μM JS-K, Caspase 9 activity was induced by 393 ± 93% and 237 ± 13% of control, respectively (p = 0.03 at the 24 hours time point). Treatment with JS-K resulted in a dose dependent activation of Caspase 3. Twenty four hours after exposure to 1 μM JS-K, Caspase 3 activity was 208 ± 3.4 % of control (p = 0.02). Treatment with JS-K also resulted in a dose dependent activation of Caspase 8, but to a lesser extent than Caspase 9 and 3. Twenty four hours after exposure to 1 μM JS-K, Caspase 8 activity was 144 ± 5.3 % of control (p = 0.04). We conclude that JS-K activates the intrinsic pathway of apoptosis in leukemia cells by inducing the release of Cytochrome c from mitochondria. (NO1-CO-12400).

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.

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