• Toxicological Research
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• v.17 no.3
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• pp.215-223
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• 2001

Cadmium is an ubiquitous toxic metal and chronic exposure to cadmium results in the accumulation of cadmium in the liver and kidneys. In contrast, acute exposure leads to damage mainly in the liver. Apoptosis induced by cadmium has been shown in many tissues in vivo and in cultured cells in vitro. However, the molecular mechanism of cadmium-induced apoptosis is not clear in hepatocyte. To investigate the induction of apoptosis in the hepatocyte, we used mouse hepatoma cell line, Hepalclc7 cells, and analysed the molecules that involved in cadmium-induced apoptosis. Cadmium induced the genomic DNA fragmentation, PARP cleavage, and activation of caspase-3 like protease. Caspase-9 cysteine protease was activated in a time-dependent manner but caspase-8 cysteine protease was not significantly activated in cadmium-treated Hepalclc7 cells. Cadmium also induced mitochondrial dysfunction including cytochrome c release from mitochondria, change oj mitochondrial membrane potential tranition, and tranlocation of Bax Protein into mitochondria. These results strong1y indicated that the signal Pathway of apoptotic death in cadmium-treated Hepalclc7 cells is modulated by caspase cascade via mitochondria.

• BMB Reports
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• v.50 no.10
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• pp.510-515
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• 2017

Triglyceride (TG) accumulation causes macrophage cell death, which affects the development of atherosclerosis. Here, we examined whether caspase-2 is implicated in TG-induced macrophage cell death. We found that caspase-2 activity is increased in TG-treated THP-1 macrophages, and that inhibition of caspase-2 activity drastically inhibits TG-induced cell death. We previously reported that TG-induced macrophage cell death is triggered by caspase-1, and thus investigated the relationship between caspase-2 and caspase-1 in TG-induced macrophage cell death. Inhibition of caspase-2 activity decreased caspase-1 activity in TG-treated macrophages. However, caspase-1 inhibition did not affect caspase-2 activity, suggesting that caspase-2 is upstream of caspase-1. Furthermore, we found that TG induces activation of caspase-3, -7, -8, and -9, as well as cleavage of PARP. Inhibition of caspase-2 and -1 decreased TG-induced caspase-3, -7, -8, and -9 activation and PARP cleavage. Taken together, these results suggest that TG-induced macrophage cell death is mediated via the caspase-2/caspase-1/apoptotic caspases/PARP pathways.

• Journal of Life Science
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• v.19 no.11
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• pp.1529-1537
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• 2009

To elucidate further the antitumor effects of a natural L-arginine analogue, L-canavanine, the mechanism underlying apoptogenic activity of L-canavanine and its modulation by protein tyrosine kinase $p56^{lck}$ was investigated in human Jurkat T cells. When the cells were treated with 1.25 to 2.5 mM L-canavanine for 36 h, several apoptotic events including mitochondrial membrane potential (${\Delta\Psi}m$) loss, activation of caspase-9, -3, -8, and -7, poly (ADP-ribose) polymerase (PARP) degradation, and DNA fragmentation were induced without alteration in the levels of Fas or FasL. These apoptotic changes were more significant in $p56^{lck}$-deficient Jurkat clone JCaM1.6 than in $p56^{lck}$-positive Jurkat clone E6.1. The L-canavanine-induced apoptosis observed in $p56^{lck}$-deficient JCaM1.6 cells was significantly reduced by introducing $p56^{lck}$ gene into JCaM1.6 cells by stable transfection. Treatment of JCaM1.6/lck cells with L-canavanine caused a transient 1.6-fold increase in the kinase activity of $p56^{lck}$. Both FADD-positive wild-type Jurkat T cell clone A3 and FADD-deficient Jurkat T cell clone I2.1 exhibited a similar susceptibility to the cytotoxicity of L-canavanine, excluding involvement of Fas/FasL system in triggering L-canavanine-induced apoptosis. The L-canavanine-induced apoptotic sub-$G_1$ peak and activation of caspase-3, -8, and -7 were abrogated by pan-caspase inhibitor (z-VAD-fmk), whereas L-canavanine-induced activation of caspase-9 was not affected. These results demonstrated that L-canavanine caused apoptosis of Jurkat T cells via the loss of ${\Delta\Psi}m$, and the activation of caspase-9, -3, -8, and -7, leading to PARP degradation, and that the $p56^{lck}$ kinase attenuated the ${\Delta\Psi}m$ loss and activation of caspases, and thus contributed as a negative regulator to L-canavanine-induced apoptosis.

• Journal of Life Science
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• v.18 no.11
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• pp.1499-1506
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• 2008

To examine antitumor activity of the edible plant Zanthoxylum schinifolium, the cytotoxic effect of various organic solvent extracts of its stems on human acute leukemia Jurkat T cells was investigated. Among these extracts such as methanol extract (SS-7), methylene chloride extract (SS-8), ethyl acetate extract (SS-9), n-butanol extract (SS-10), and residual fraction (SL-11), SS-8 exhibited the most cytotoxic activity against Jurkat T cells. The methylene chloride extract (SS-8) possessed the apoptogenic activity capable of inducing sub-G1 peak along with apoptotic DNA fragmentation in Jurkat T cells. Western blot analysis revealed that SS-8 induced apoptosis via mitochondrial cytochrome c release into cytoplasm, subsequent activation of caspase-9 and caspase-3, and cleavage of PARP, which could be blocked by overexpression of Bcl-xL. Jurkat T cell clone I2.1 $FADD^{-/-}$) and Jurkat T cell clone I9.2 (caspase-$8^{-/-}$ were as sensitive as was the wild-type Jurkat T cell clone A3 to the cytotoxic effect of SS-8, suggesting no contribution of Fas/FasL system to the SS-8-mediated apoptosis. The GC-MS analysis of SS-8 showed that it was composed of 16 ingredients including 9,12-octadecanoic acid (18.62%), 2,4-dihydro-5-methyl-4- (1-methylethylidene)- 2-(4-nitrophenyl)-3H- pyrazol-3-one (14.97%), hexadecanoic acid (14.23%), (z,z)-6,9-pentadecadien- 1-ol (13.73%), 5,6-dimethoxy-2-methyl benzofuran (10.95%), and 4-methoxy-2-methylcinnamic acid (5.38%). These results demonstrate that the methylene chloride extract of the stems of Z. schinifolium can induce apoptotic cell death in Jurkat T cells via intrinsic mitochondria-dependent caspase cascade regulated by Bcl-xL without involvement of the Fas/FasL system.

• Journal of Life Science
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• v.20 no.9
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• pp.1409-1414
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• 2010

The aim of this study was to investigate the effects of exercise on intrinsic and extrinsic apoptosis signaling pathways in skeletal muscle. ICR-type white male mice were divided into a control group (CON: n=10) and an exercise training group (EX: n=10) after a 1 week adaptation period. EX performed treadmill running at 16.4 m/min with a 4% incline, 40 min/day and 5 days/week for 8 weeks. Cervical dislocation was performed at 48 hours after the last bout of exercise, after which gastrocnemius skeletal muscles were immediately collected. The results of verifying the intrinsic apoptosis pathway showed that there were no significant differences in Bcl-2, Bax, or the ratio of Bax/Bcl-2 proteins between EX and CON. On the other hand, the results of verifying the extrinsic apoptosis pathway showed that caspase-8 proteins were significantly lower in EX than in CON (p<0.05). Apoptosis suppressing protein HSP70 was higher in EX than in CON. In addition, caspase-3, which is the final factor for apoptosis, was not activated. These results indicate that apoptosis did not develop since caspase-3 is non-cleaved by the effects of caspase-8 and HSP70 extrinsic pathways rather than Bcl-2 and Bax intrinsic pathways among signal pathways for apoptosis.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.15
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• pp.6075-6080
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• 2014

Lung cancer is the leading cause of cancer-related death worldwide. Here we investigated the antitumor effect and mechanism of Zhejiang (Huzhou and Jiande) saffron against lung cancer cell lines, A549 and H446. Using high performance liquid chromatography (HPLC), the contents of crocin I and II were determined. In vitro, MTT assay and annexin-V FITC/PI staining showed cell proliferation activity and apoptosis to be changed in a dose- and time-dependent manner. The inhibition effect of Jiande saffron was the strongest. In vivo, when mice were orally administered saffron extracts at dose of 100mg/kg/d for 28 days, xenograft tumor size was reduced, and ELISA and Western blotting analysis of caspase-3, -8 and -9 exhibited stronger expression and activity than in the control. In summary, saffron from Zhejiang has significant antitumor effects in vitro and in vivo through caspase-8-caspase-9-caspase-3 mediated cell apoptosis. It thus appears to have more potential as a therapeutic agent.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.3
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• pp.772-778
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• 2005

The chloromethyl-2-dihydroxyphosphinyl-6,7-dimethoxy-1,2,3,4-tetrahydro- isoquinoline (CDDT) is a newly synthesized derivative from 1,2,3,4-Tetra- hydroisoquinoline (THIQ). The THIQs include potent cytotoxic agents that display a range of antitumor activities, antimicrobial activity, and other biological properties. In this study, we investigated the effect of CDDT on the cytotoxicity, induction of apoptosis in human promyelocytic leukemia cells (HL-60 cells). CDDT showed a significant cytotoxic activity in HL-60 cells ($IC_{50}$ = approximately $37\;{\mu}g/ml$) at a 24 hr incubation. Treatment of HL-60 cells with CDDT displayed several features of apoptosis, including formation of DNA ladders in agarose gel electrophoresis, morphological changes of HL-60 cells with DAPI stain. Here we observed that CDDT caused activation of caspase-3, caspase-8, and caspase-9. The most efficacious time on the activation of caspases-3 was achieved at 12 hr. Further molecular analysis demonstrated that CDDT led to cleavage of poly(ADP-ribose) polymerase (PARP), increase of hypodiploid (Sub-G1) population in the flow cytometric analysis. In conclusion, these above results indicate that CDDT dramatically suppresses HL-60 cell growth by activation of caspase-3 with caspase-8, -9 activity. These data may support a pivotal mechanism for the use of CDDT in the prevention and treatment of leukemia.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.11
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• pp.6469-6473
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• 2013

The aim of this study was to detect the efficiency of arsenic trioxide (ATO) alone or together with bortezomib to inhibit proliferation and induce apoptosis in a multiple myeloma (MM) RPMI 8266 cells. Mechanisms of action were also investigated. RPMI 8266 cells were treated with ATO alone and in combination with bortezomib for 24 hours, and cell viability was assessed by modified MTT. Annexin V-F1TC and PI staining was used to detect the apoptosis rate and cell cycling was investigated by flow cytometry, along with expression of cell surface death receptor-4(DR4) and death receptor-5 (DR5). Western blotting was applied to detect the expression of bcl-2, caspase-3, caspase-8, and caspase-9. As a result, the ATO combined with bortezomib group showed more inhibition of RPMI 8266 cell viability than theATO group. Expression of DR4 and DR5 on the cell surfaces, and the apoptosis rate were increased after treatment by ATO alone or combined with bortezomib. The cells appeared to arrest in G2/M phase after treatment. Expression of bcl-2 was more significantly decreased in the combination group, and that of caspase-3, caspase-8 and caspase-9 was significantly increased as well. Therefore, bortezomib can enhance ATO actions to induce apoptosis in RPMI 8266 cells, with decrease in expression of bcl-2 and increase of caspase-3, caspase-8 and caspase-9 proteins.

• Journal of Integrative Natural Science
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• v.7 no.2
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• pp.87-91
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• 2014

Amyloid beta ($A{\beta}$) peptide has been implicated in the pathogenesis of Alzheimer's disease and has been reported to induce apoptotic death in cell culture. Cysteine Proteases, a family of enzymes known as caspases, mediate cell death in many models of apoptosis. In the present study, we examined the caspase activity and cell death in $A{\beta}$-treated SHSY5Y cells, as an attempt to elucidate the relationship between the type of caspase and $A{\beta}$-induced cell death. $A{\beta}$ at 20 ${\mu}M$ induce activation of caspase-3, 8 and 9 activity, but not the caspase-1. Caspase-3, 8 and 9 were processed by Ab treatment, consistent with the activity assay. Inhibition of the caspase activities by the selective inhibitors, however, marginally affected the cell death induced by $A{\beta}$. Taken together, the results indicate that $A{\beta}$-induced cell death may be independent of caspase activity and rather, the enzymes might be activated as a result of the cell death.

• Journal of Life Science
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• v.13 no.1
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• pp.118-127
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• 2003

$\rho$-Fluorophenylalanine (FPA), a phenylalanine analog, is able to induce apoptotic cell death of human acute leukemia Jurkat T cells. To better understand the mechanism by which FPA induces apoptotic cell death, the effect of ectopic expression of antiapoptotic proteins, Bcl-2 and Bcl-xL, on FPA-induced apoptosis was investigated by employing lurkat T cells transfected with Bcl-2 gene (JT/Bcl-2) or Bcl-xL gene (1/Bcl-xL) and Jurkat T cells transfected with vector (JT/Neo or J/Neo). When Jurkat T cells, JT/Neo or J/Neo, were exposed to FPA at concentrations ranging from 0.63 to 5.0 mM, the cell viability determined by MTT assay declined in a dose-dependent manner. In addition, apoptotic DNA fragmentation along with several apoptotic events such as caspase-8 activation, Bid cleavage, mitochondrial cytochrome c release, caspase-9 activation, caspase-3 activation, and degradation of PARP was induced. However, the FPA-induced cytotoxic effect, activation of caspase-8, and cleavage of Bid were significantly abrogated by ectopic expression of Bcl-2 or Bcl-xL. At the same time, there was marked reduction in the level of cytochrome c release from mitorhondria, caspase-9 activation, caspase-3 activation, and degradation of PARP. These results indicate that caspase-8 activation, Bid cleavage, and mitochondrial cytochrome c release with subsequent activation of the caspase cascade are negatively regulated by Bcl-2 or Bcl-xL, and are thus required for FPA-induced apoptosis in Jurkat T cells