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

• Molecules and Cells
• /
• v.26 no.2
• /
• pp.152-157
• /
• 2008

Caspases play critical roles in the execution of apoptosis. Caspase-3 and caspase-7 are closely related in sequence as well as in substrate specificity. The two caspases have overlapping substrate specificities with special preference for the DEVD motif. However, they are targeted to different subcellular locations during apoptosis, implying the existence of substrates specific for one or other caspase. To identify new caspase-7 substrates, we digested cell lysates obtained from the caspase-3-deficient MCF-7 cell line with purified recombinant caspase-7, and analyzed spots that disappeared or decreased by 2-DE (we refer to this as the caspase-7 degradome). Several proteins with various cellular functions underwent caspase-7-dependent proteolysis. The substrates of capase-7 identified by the degradomic approach were rather different from those of caspase-3 (Proteomics, 4, 3429-3435, 2004). Among the candidate substrates, we confirmed that Valosin-containing protein (VCP) was cleaved by both capspase-7 and caspase-3 in vitro and during apoptosis. Cleavage occurred at both $DELD^{307}$ and $DELD^{580}$. The degradomic study yielded several candidate caspase-7 substrates and their further analysis should provide valuables clues to the functions of caspase-7 during apoptosis.

• Food Science and Biotechnology
• /
• v.17 no.1
• /
• pp.216-218
• /
• 2008

The present study was designed to determine how the phytochemical genistein activates caspase-3 to cause cell cycle arrest and apoptosis. When human ovarian cancer SK-OV-3 cells were treated with $200\;{\mu}M$ genistein for 24 hr, cell growth decreased significantly (p<0.05). Conversely, genistein treatment significantly increased cytotoxicity (measured as lactate dehydrogenase release) under the same conditions (p<0.05). To elucidate the mechanism behind the induction of apoptosis by genistein, we studied the cell cycle and caspase-3 activation. When cells were treated with genistein, the population of cells in sub-G1 phase increased by 44.2% compared to untreated cells. Genistein caused decrease in precursor caspase-3, increase in cleaved caspase-3 and a significant increase in caspase-3 activity (p<0.05). Therefore, genistein may induce apoptosis via caspase-3 activation. However, high-dose genistein treatment must be viewed with caution because of its potential cytotoxicity.

• BMB Reports
• /
• v.56 no.3
• /
• pp.166-171
• /
• 2023

Monocytes are peripheral leukocytes that function in innate immunity. Excessive triglyceride (TG) accumulation causes monocyte death and thus can compromise innate immunity. However, the mechanisms by which TG mediates monocyte death remain unclear to date. Thus, this study aimed to elucidate the mechanisms by which TG induces monocyte death. Results showed that TG induced monocyte death by activating caspase-3/7 and promoting poly (ADP-ribose) polymerase (PARP) cleavage. In addition, TG induced DNA damage and activated the ataxia telangiectasia mutated (ATM)/checkpoint kinase 2 and ATM-and Rad3-related (ATR)/checkpoint kinase 1 pathways, leading to the cell death. Furthermore, TG-induced DNA damage and monocyte death were mediated by caspase-2 and -8, and caspase-8 acted as an upstream molecule of caspase-2. Taken together, these results suggest that TG-induced monocyte death is mediated via the caspase-8/caspase-2/DNA damage/executioner caspase/PARP pathways.

• Journal of Oral Medicine and Pain
• /
• v.25 no.3
• /
• pp.265-276
• /
• 2000

스트레스가 타액선 조직을 변형시키고 파괴시킬 수 있다는 것은 이미 보고된 바 있다. 이는 구속스트레스 시에 관찰되는 apoptosis에 의한 것인데, 이 과정에 관여하는 caspase-3는 세포의 DNA를 분절시킴으로서 apoptosis를 일으킨다고 알려진 세포내 단백효소이다. 이에 기존에 관찰되었던 구속 스트레스에 의한 apoptosis의 형태적 변화가 apoptosis를 유도하는 caspase-3와 어떠한 시기적 상관관계를 가지고 있는지를 구명하기 위하여 본 실험을 시행하였다. 웅성 백서 (Sprague-Dawley, 8주) 를 사용하여 실험 전 기간에 걸쳐 구속스트레스를 가한 후 30분, 1시간, 3시간, 6시간, 24시간, 3일, 5일, 7일에 희생시켰다. 그 후 실험동물의 악하선을 절취하여 동결절편을 제작한 후, caspase-3에 대한 형광항체로 면역형광법을 시행하여 관찰하였다. 1. 정상대조군에서는 caspase-3가 타액선 조직 전반에서 미약하게 관찰되었다. 2. 구속스트레스 부여 30분에서 caspase-3는 강반응을 보였고, 실험기간이 경과됨에따라 점차 6시간군에서 부터는 현저히 감소하였다. 3. Caspase-3는 구속 스트레스 30분에 도관과 선포세포 모두에서 발현되었으나, 선포세포에서는 조기에 급격히 소실되었고 도관세포에서는 전 실험 기간에 걸쳐 서서히 소실되었다. 이와 같은 연구 결과에서, 세포내 caspase-3는 조직의 형태적 변화가 나타나기 이전에 발현하는 것으로 보아 caspase-3는 형태적 변화를 예견할 수 있는 진단 지표로 사용될 수 있을 것으로 사료되며 이후 임상적으로 적용하기 위한 지속적인 연구가 필요할 것으로 생각된다.

• Neonatal Medicine
• /
• v.17 no.1
• /
• pp.44-52
• /
• 2010

Purpose : The aim of this study was to develop a model for necrotizing enterocolitis (NEC) in the neonatal rat using endotoxin and hypoxia, a plausible insult in a neonatal intensive care and to investigate the role of apoptosis as the underlying mechanism. Methods : Newborn rats were given oral endotoxin and intermittent 8% hypoxia$\pm$caspase inhibitor. The intestinal histology was evaluated using hematoxylin-eosin staining. Apoptosis was analyzed with TUNEL staining and by measuring the caspase 3 activity in the intestinal lysates. IEC-6 cells were assessed for apoptosis and the expression of Bax, Bcl-2, Fas and FasL was measured after treatment with endotoxin and hypoxia. Results : Oral endotoxin (5 mg/kg) and exposure to 8% hypoxia of 60-min duration twice induced human NEC-like lesions in the rat intestine. Intestinal tissue revealed increased apoptosis and caspase-3 activity. After caspase inhibitor treatment, the grades of both apoptosis and NEC were significantly reduced. IEC-6 cells exhibited increased apoptosis and caspase 3 activity after endotoxin and hypoxia treatment and significantly increased Bax/Bcl- 2 ratio compared to control cells. Conclusion : This neonatal rat model of NEC which was induced by oral endotoxin and intermittent hypoxia showed increased apoptosis of intestinal epithelial cells that was mediated by caspase 3 activation. Our model has a advantage in the study of NEC because the use of much more clinically plausible insults may provide a suitable model for the investigation of its pathophysiology and therapeutic trials.

• Journal of Life Science
• /
• v.10 no.2
• /
• pp.21-26
• /
• 2000

Cytokine deprivation-induced apoptosis can abrogate by the appropriate survival factors. Because the mechanism of Interleukin (IL)-2 deprived apoptotic cell death remains unclear, we here show the apoptosis in CTLL2 cells correlates with an increase of the activity of caspase3-like protease(s). Inhibition of caspase3-like protease(s) with caspase protease inhibitors (Z-VAD, Z-EVD, and Z-LPD) blocks typical apoptotic morphological abnormalities in CTLL2 cells. Interestingly, Bcl-{TEX}$X_{L}${/TEX} protein was decreased by IL-2 deprivation in the cells. These results suggest that caspase3-like protease(s), not caspase1, plays an important role in apoptosis execution of CTLL2 cell death.

• The Journal of the Korea Contents Association
• /
• v.16 no.3
• /
• pp.661-666
• /
• 2016

In this study, a linear accelerator (LINAC) through 3 Gy of radiation per body irradiated mice of the small intestine and the liver to produce in order to protect the cells after radiation exposure that caspase (caspase 3 &caspase 9) and NO (nitric oxide), and looked like to know cytokine of IL-6 and TNF-${\alpha}$, the result is as follows. First, caspase 3 & caspase 9 showed a noticeable increase in the radiation group than in the control group both small intestine and liver tissues (P <0.001). Second, NO are both intestine and liver tissue showed a marked increase in the radiation group than in the control group (P <0.001). Third, one of Cytokine IL-6 and TNF-${\alpha}$ showed a significant increase in the irradiated group than the control group both small intestine and liver tissues (P <0.001).

• Animal cells and systems
• /
• v.16 no.4
• /
• pp.295-301
• /
• 2012

Interdigital tissue regression is one of the most well-known examples of embryonic programmed cell death, providing the mechanism behind separation of developing digits. Caspases have been shown to play a key part in this process, with activated caspase-3 localized between the developing digits. In caspase-3 knock-out adult mice, however, the digits are completely separated with no webbing. In other mutants with defects in the apoptotic machinery, such as Apaf1 deficient mice, interdigital tissue regression is initially inhibited but the webbing eventually disappears as alternative/additional cell death mechanisms step in. In order to investigate whether a similar temporal effect occurs after loss of caspase-3, we have used an in vitro approach to inhibit caspase-3 at specific times during digit separation. Previous limb explant culture approaches have encountered problems with proper limb development in culture, and thus a modified technique was used. The new approach enables detailed observation of the effects of caspase-3 inhibition on interdigital regression. Using these methods, we show that caspase-3 inhibition caused a delay in the loss of interdigital tissue compared with control explants, similar to that observed in Apaf1 mutant mice. Along with immunohistochemistry, active caspase-3 positive cells of the interdigital vs. digital regions were measured by flow cytometry. Notably, activated caspase-3 in vivo was found not only in the interdigital mesenchyme but also in the TUNEL negative digit region, supporting a role for caspase-3 in nonapoptotic events.

• BMB Reports
• /
• v.37 no.4
• /
• pp.445-453
• /
• 2004

We identified apoptosis as being a significant mechanism of toxicity following the exposure of HeLa cell cultures to abrin holotoxin, which is in addition to its inhibition of protein biosynthesis by N-glycosidase activity. The treatment of HeLa cell cultures with abrin resulted in apoptotic cell death, as characterized by morphological and biochemical changes, i.e., cell shrinkage, internucleosomal DNA fragmentation, the occurrence of hypodiploid DNA, chromatin condensation, nuclear breakdown, DNA single strand breaks by TUNEL assay, and phosphatidylserine (PS) externalization. This apoptotic cell death was accompanied by caspase-9 and caspase-3 activation, as indicated by the cleavage of caspase substrates, which was preceded by mitochondrial cytochrome c release. The broad-spectrum caspase inhibitor, benzyloxycarbonyl-Val-Ala-Asp-fluoromethyl ketone (zVAD-fmk), prevented abrin-triggered caspase activation and partially abolished apoptotic cell death, but did not affect mitochondrial cytochrome c release. These results suggest that the release of mitochondrial cytochrome c, and the sequential caspase-9 and caspase-3 activations are important events in the signal transduction pathway of abrin-induced apoptotic cell death in the HeLa cell line.