• 대한한의학방제학회지
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• 제25권2호
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• pp.145-154
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• 2017

Objectives : Bufalin is one of the bioactive component of 'Sum Su (蟾酥)', which is obtained from the skin and parotid venom gland of toad. Bufalin has been known to possess the inhibitory effects on cell proliferation and inducing apoptosis in various cancer cells. The tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) has concerned, because it can selectively induce apoptotic cell death in many types of malignant cells, while it is relatively non-toxic to normal cells. Here, we investigated whether bufalin can trigger TRAIL-induced apoptotic cell death in EJ human bladder cancer cells. Methods : Effects on the cell viability and apoptotic activity were quantified using MTT assay and flow cytometry analysis, respectively. To investigate the morphological change of nucleus, DAPI staining was performed. Protein expressions were measured by immunoblotting. Results : A combined treatment with bufalin (10 nM) and TRAIL (50 ng/ml) significantly promoted TRAIL-mediated growth inhibition and apoptosis in EJ cells. The apoptotic effects were associated with the up-regulation of death receptor proteins, and the down-regulation of cFLIP and XIAP. Moreover, our data showed that bufalin and TRAIL combination activated caspases and subsequently increased degradation of poly(ADP-ribose) polymerase. Conclusions : Taken altogether, the nontoxic doses of bufalin sensitized TRAIL-mediated apoptosis in EJ cells. Therefore, bufalin might be an effective therapeutic strategy for the safe treatment of TRAIL-resistant bladder cancers.

• The Korean Journal of Physiology and Pharmacology
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• 제8권4호
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• pp.187-194
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• 2004

Middle cerebral artery occlusion (MCAO) results in cell death by activation of complex signal pathways for cell death and survival. Hypothermia is a robust neuroprotectant, and its effect has often been attributed to various mechanisms, but it is not yet clear. Upstream from the cell death promoters and executioners are several enzymes that may activate several transcription factors involved in cell death and survival. In this study, we immunohistochemically examined the phosphorylation of mitogen-activated protein kinase, extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) and p38 kinase during early period of the ischemic injury, following 2 hours (h) of transient MCAO. Increased phosphorylation of ERK and p38 was observed in the vessels at 3 h, neuron-like cells at 6 and 12 h and glia-like cells at 12 h. Activation of JNK was not remarkable, and a few cells showed active JNK following ischemia. Phosphorylation of Elk-1, a transcription factor, was reduced by ischemic insult. Hypothermia attenuated the activation of ERK, p38 and JNK, and inhibited reduction of Elk-1. These data suggest that signals via different MAPK family members converge on the cell damage process and hypothermia protects the brain by interfering with these pathways.

• The Korean Journal of Physiology and Pharmacology
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• 제18권1호
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• pp.73-78
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• 2014

Cell death and survival are tightly controlled through the highly coordinated activation/inhibition of diverse signal transduction pathways to insure normal development and physiology. Imbalance between cell death and survival often leads to autoimmune diseases and cancer. Death receptors sense extracellular signals to induce caspase-mediated apoptosis. Acting upstream of CED-3 family proteases, such as caspase-3, Bcl-2 prevents apoptosis. Using short hairpin RNAs (shRNAs), we suppressed Bcl-2 expression in Jurkat T cells, and this increased TCR-triggered AICD and enhanced TNFR gene expression. Also, knockdown of Bcl-2 in Jurkat T cells suppressed the gene expression of FLIP, TNF receptor-associated factors 3 (TRAF3) and TRAF4. Furthermore, suppressed Bcl-2 expression increased caspase-3 and diminished nuclear factor kappa B (NF-${\kappa}B$) translocation.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2003년도 Annual Meeting of KSAP : International Symposium on Pharmaceutical and Biomedical Sciences on Obesity
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• pp.67-67
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• 2003

Minocycline is known to protect neurons from microglia-mediated cell death in many experimental models of brain diseases including ischemic stroke, Huntingtons disease (HD), amyotrophic lateral sclerosis (ALS), traumatic brain injury, multiple sclerosis, and Parkinsons disease. When the activity of caspases was assessed using their fluorescent peptide substrates, activation of caspase-2, 3, 8, and 9 was evident within 2 8 hr following oxidative insult with 0.5 mM hydrogen peroxide in PC12 cells. Minocycline significantly attenuated activation of these caspases up to 18 hr, resulting a significant increase in the cell viability as assessed by MTT assay as well as trypan blue staining. However, cleavage of alpha-spectrin and a cdk5 activator p35, which are known to be substrates for calpain, remained unchanged in the presence of minocycline, suggesting that minocycline did not block caspase-3-independent cell death or necrosis. Moreover, co-treatment with minocycline and a calpain inhibitor calpeptin synergistically inhibited hydrogen peroxide-induced cell death. These data suggest that minocycline directly inhibited apoptosis, but not necrosis, after oxidative insult in PC12 cells.

• BMB Reports
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• 제49권10호
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• pp.560-565
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• 2016

Granzyme A (GzmA) was first identified as a cytotoxic T lymphocyte protease protein with limited tissue expression. A number of cellular proteins are known to be cleaved by GzmA, and its function is to induce apoptosis. Histones H1, H2B, and H3 were identified as GzmA substrates during apoptotic cell death. Here, we demonstrated that histone H4 was cleaved by GzmA during staurosporine-induced cell death; however, in the presence of caspase inhibitors, staurosporine-treated Raji cells underwent necroptosis instead of apoptosis. Furthermore, histone H4 cleavage was blocked by the GzmA inhibitor nafamostat mesylate and by GzmA knockdown using siRNA. These results suggest that histone H4 is a novel substrate for GzmA in staurosporine-induced cells.

• 생명과학회지
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• 제19권8호
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• pp.1016-1022
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• 2009

융단조직은 약실 내에서 발달하는 소포자에 영양분을 공급하고 퇴화되는 조직으로써, 소포자 4분자 시기에 최대로 발달하고 화분벽에 포분질에 축적된 후 프로그램 세포사가 일어남으로써 세포가 죽게 되고 융단조직 전체가 퇴화된다. 액포가 융합되므로써 프로그램 세포사가 시작되고 세포질응축, 핵질 분절 등이 뒤따라 일어난다. 지질 덩어리는 비교적 늦은 시기에 퇴화되며 orbicular body는 가장 늦게까지 남아 있게 된다. 융단세포의 프로그램세포사 전 과정 중에서 세포벽은 액포에서 기원하는 가수분해 효소에 비교적 안정적이므로 가장 늦게 퇴화되는 것으로 확인되었다.

• 한국약용작물학회지
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• 제23권2호
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• pp.144-149
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• 2015

The peel of Citrus sunki exhibits multiple biological activities such as anti-oxidant, anti-inflammation and anti-obesity, but little is known about neurodegeneration-related activities. In this study, we investigated the protective effect of ethanolic extract from both immature and mature Citrus sunki peel on neuronal cell death. Treatment of the neuroblastoma cell line SH-SY5Y with $MPP^+$, an inducer of Parkinson disease model, increased cell death in a dose dependent manner. Increased levels of active caspase-3 and cleaved PARP were detected. Treatment with immature Citrus sunki peel extract significantly reduced $MPP^+$-induced neurotoxicity. Cytoprotection with immature Citrus sunki peel extract was associated with a decrease in caspase-3 activation and PARP cleavage. In contrast, mature Citrus sunki peel extract had no significant effects. These data suggest that immature Citrus sunki peel extract may exert anti-apoptotic effect through the inhibition of caspase-3 signaling pathway on $MPP^+$-induced neuronal cell death.

• Journal of Acupuncture Research
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• 제23권2호
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• pp.47-59
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• 2006

We previously found that cobrotoxin inhibited $NF-{\kappa}B$ activity by reacting with signal molecules of $NF-{\kappa}B$ which is critical contributor in cancer cell growth by induction of apoptotic cell death. We here investigated whether cobrotoxin inhibits cell growth of human prostate cancer cells through induction of apoptotic cell death, which is related with the suppression of the $NF-{\kappa}B$ activity. Cobrotoxin $(0{\sim}8\;nM)$ inhibited prostate cancer cell growth through increased apoptosis in a dose dependent manner. Cobrotoxin inhibited DNA binding activity of $NF-{\kappa}B$, an anti-apoptotic transcriptional factor. Consistent with the induction of apoptosis and inhibition of $NF-{\kappa}B$, cobrotoxin increased the expression of pro-apoptotic proteins caspase 3. Cobrotoxin, a venom of Vipera lebetina turanica, is a group of basicpeptides composed of 233 amino acids with six disulfide bonds formed by twelve cysteins. NF-kB is activated by subsequent release of inhibitory IkB and translocation of p50. Since sulfhydryl group is present in kinase domain of p50 subunit of NF-kB, cobrotoxin could modify NF-kB activity by protein-protein interaction. And Cobrotoxin down regulated Akt signals. Salicylic acid as a reducing agent of Sulf-hydryl group and LY294002 as a Akt inhibitor abrogated cobrotoxin-induced cell growth and DNA binding activity of $NF-{\kappa}B$. These findings suggest that nano to pico molar range of cobrotoxin could inhibit prostate cancer cell growth, and the effect may be related with the induction of apoptotic cell death through Akt dependent inhibition of $NF-{\kappa}B$ signal.

• Archives of Pharmacal Research
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• 제26권11호
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• pp.937-942
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• 2003

Nitric oxide(NO) induces apoptosis in human osteoblasts. Treatment with exogenous NO donors, SNAP (S-Nitroso-N-acelylpenicillamine) and SNP (sodium nitroprusside), to MG-63 osteoblasts resulted in apoptotic morphological changes, as shown by a bright blue-fluorescent condensed nuclei and chromatin fragmentation by fluorescence microscope of Hoechst 33258-staining. The activities of caspase-9 and the subsequent caspase-3-like cysteine proteases were increased during NO-induced cell death. Pretreatment with Z-VAD-FMK (a pancaspase inhibitor) or Ac-DEVD-CHO (a specific caspase-3 inhibitor) abrogated the NO-induced cell death. The NO donor markedly activated JNK, a stress-activated protein kinase in the human osteoblasts. This study showed that the inhibition of the JNK pathway markedly reduced NO-induced cell death. But neither PD98059 (MEK inhibitor) nor SB203580 (p38 MAPK inhibitor) had any effect on NO-induced death. Taken together, these results suggest that JNK/SAPK may be related to NO-induced apoptosis in MG-63 human osteoblasts.

• Biomolecules & Therapeutics
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• 제22권3호
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• pp.167-175
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• 2014

Chemotherapy has long been considered as one of useful strategies for cancer treatment. It is primarily based on the apoptosis that can selectively kill cancer cells. However, cancer cells can progressively develop an acquired resistance to apoptotic cell death, rendering refractory to chemo- and radiotherapies. Although the mechanism by which cells attained resistance to drug remains to be clarified, it might be caused by either pumping out of them or interfering with apoptotic signal cascades in response to cancer drugs. In case that cancer cells are defective in some part of apoptotic machinery by repeated exposure to anticancer drugs, alternative cell death mechanistically distinct from apoptosis could be adopted to remove cancer cells refractory to apoptosis-inducing agents. This review will mainly deal with harnessing of necrotic cell death, specifically, programmed necrosis and practical uses. Here, we begin with various defects of apoptotic death machinery in cancer cells, and then provide new perspective on programmed necrosis as an alternative anticancer approach.