scholarly journals Selective Cleavage of BLM, the Bloom Syndrome Protein, during Apoptotic Cell Death

2001 ◽  
Vol 276 (15) ◽  
pp. 12068-12075 ◽  
Author(s):  
Oliver Bischof ◽  
Sanjeev Galande ◽  
Farzin Farzaneh ◽  
Terumi Kohwi-Shigematsu ◽  
Judith Campisi
Keyword(s):  
Caspase 3 ◽  
Apoptotic Cell ◽  
Autosomal Recessive Disorder ◽  
Bloom Syndrome ◽  
Recognition Sequence ◽  
Blm Helicase ◽  
Caspase 6 ◽  
Syndrome Protein ◽  
Condensed Dna

Bloom syndrome (BS) is an autosomal recessive disorder characterized by a high incidence of cancer and genomic instability. BLM, the protein defective in BS, is a RECQ-like helicase that is presumed to function in mammalian DNA replication, recombination, or repair. We show here that BLM, but not the related RECQ-like helicase WRN, is rapidly cleaved in cells undergoing apoptosis. BLM was cleaved to 47- and 110-kDa major fragments, with kinetics similar to the apoptotic cleavage of poly(A)DP-ribose polymerase. BLM cleavage was prevented by a caspase 3 inhibitor and did not occur in caspase 3-deficient cells. Moreover, recombinant BLM was cleaved to 47- and 110-kDa fragments by caspase 3, but not caspase 6,in vitro. The caspase 3 recognition sequence412TEVD415was verified by mutating aspartate 415 to glycine and showing that this mutation rendered BLM resistant to caspase 3 cleavage. Cleavage did not abolish the BLM helicase activity but abolished BLM nuclear foci and the association of BLM with condensed DNA and the insoluble matrix. The results suggest that BLM, but not WRN, is an early selected target during the execution of apoptosis.

Biochemical Characterisation of an In Vitro Model of Hepatocellular Apoptotic Cell Death

2009 ◽  
Vol 37 (2) ◽  
pp. 209-218 ◽  
Author(s):  
Mathieu Vinken ◽  
Elke Decrock ◽  
Elke De Vuyst ◽  
Luc Leybaert ◽  
Tamara Vanhaecke ◽  
...  
Keyword(s):  
Cell Death ◽  
In Vitro Model ◽  
Caspase 3 ◽  
Fas Ligand ◽  
Apoptotic Cell ◽  
Annexin V ◽  
Apoptotic Cell Death ◽  
Biochemical Characterisation ◽  
Vitro Model

This study was set up to critically evaluate a commonly-used in vitro model of hepatocellular apoptotic cell death, in which freshly isolated hepatocytes, cultured in a monolayer configuration, are exposed to a combination of Fas ligand and cycloheximide for six hours. A set of well-acknowledged cell death markers was addressed: a) cell morphology was studied by light microscopy; b) apoptotic and necrotic cell populations were quantified by in situ staining with Annexin-V, Hoechst 33342 and propidium iodide (PI); c) apoptotic and necrotic activities were monitored by probing caspase 3-like activity and measuring the extracellular leakage of lactate dehydrogenase (LDH), respectively; and d) the expression of apoptosis regulators was investigated by immunoblotting. The initiation of apoptosis was evidenced by the activation of caspase 8 and caspase 9, and increased Annexin-V reactivity. Progression through the apoptotic process was confirmed by the activation of caspase 3 and Bid, the enhanced expression of Bax, and the occurrence of nuclear fragmentation. Late transition to a necrotic appearance was demonstrated by an increased number of PI-positive cells and augmented extracellular release of LDH. Thus, the in vitro model allows the study of the entire course of Fas-mediated hepatocellular apoptotic cell death, which is not possible in vivo. This experimental system can serve a broad range of in vitro pharmaco-toxicological purposes, thereby directly assisting in the reduction of animal experimentation.

scholarly journals Withdrawal: Selective cleavage of BLM, the Bloom syndrome protein, during apoptotic cell death.

2020 ◽  
Vol 295 (49) ◽  
pp. 16905-16905
Author(s):  
Oliver Bischof ◽  
Sanjeev Galande ◽  
Farzin Farzaneh ◽  
Terumi Kohwi-Shigematsu ◽  
Judith Campisi
Keyword(s):  
Cell Death ◽  
Apoptotic Cell ◽  
Bloom Syndrome ◽  
Apoptotic Cell Death ◽  
Syndrome Protein

scholarly journals Neuroprotective Activity ofSibjeondaebo-tangon AβPeptide-Induced Damages

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Hyeon Ju Yim ◽  
Jung Hwa Lim ◽  
Min Hee Kim ◽  
Uk Namgung ◽  
Sang Ryong Lee ◽  
...  
Keyword(s):  
Pc12 Cells ◽  
Cortical Neurons ◽  
Caspase 3 ◽  
Apoptotic Cell ◽  
Immunofluorescence Staining ◽  
Neuroprotective Activity ◽  
Potential Therapeutic Target ◽  
Protein Levels

Background.Sibjeondaebo-tang(SJDBT) has been used to treat diverse disorders including neuropsychiatric disabilities in traditional Korean medicine.Objective. The present study aims to investigate the potential effects of SJDBT on neuroprotection against Aβ peptide-induced damage usingin vitroculture andin vivorat brain systems.Materials and Methods. PC12 cell viability was analyzed by MTT assay, and neurite arborizations and caspase 3 protein signals in cultured PC12 cells andin vivocortical neurons were analyzed by immunofluorescence staining. Phospho-Erk1/2 protein was analyzed by immunofluorescence staining and western blot analysis.Results. In PC12 cells, atrophied cell body and reduced neurite extension by Aβtreatment were recovered by SJDBT treatment. Caspase 3 protein signals were increased in Aβ-treated PC12 cells, but SJDBT treatment decreased apoptotic cell death. Caspase 3 activation in cortical neurons, which was induced similarly by Aβtreatment, was reduced by SJDBT treatment. Furthermore, phospho-Erk1/2 protein levels, which had been decreased by Aβtreatment, were elevated in the cortical neurons by SJDBT treatment.Conclusion. These data show that SJDBT may play a role in protecting from damages induced by Aβin neuronal tissue and further suggest that SJDBT can be explored as the potential therapeutic target for AD treatments in human.

Mediation of multiple pathways regulating cell proliferation, migration, and apoptosis in the human malignant glioma cell line U87MG via unphosphorylated STAT1

2013 ◽  
Vol 118 (6) ◽  
pp. 1239-1247 ◽  
Author(s):  
Haitao Ju ◽  
Xin Li ◽  
Hong Li ◽  
Xiaojuan Wang ◽  
Hongwei Wang ◽  
...  
Keyword(s):  
Cell Growth ◽  
Western Blot ◽  
Caspase 3 ◽  
Apoptotic Cell ◽  
Glioma Cell Line ◽  
Significant Inhibition ◽  
Cell Counting ◽  
Nuclear Antigen ◽  
Normal Brain

Object Signal transducer and activator of transcription 1 (STAT1) is thought to be a tumor suppressor protein. The authors investigated the expression and role of STAT1 in glioblastoma. Methods Immunohistochemistry was used to detect the expression of STAT1 in glioblastoma and normal brain tissues. Reverse transcription–polymerase chain reaction and Western blot analysis were used to detect mRNA and protein expression levels of STAT1. Cell growth, proliferation, migration, apoptosis, and the expression of related genes and proteins (Bcl-2, Bax, cleaved caspase-3, caspase-9, p21, and proliferating cell nuclear antigen) were examined in vitro via cell counting kit-8, wound-healing, flow cytometry, Rhodamine B, TUNEL, and Western blot assays. Results Human glioblastoma had decreased expression of STAT1 proteins. Transfection of the U87MG cells with STAT1 plasmid in vitro demonstrated significant inhibition of cell growth and an increase in apoptotic cell death compared with cells transfected with vector or mock plasmids. These effects were associated with the upregulation of cleaved caspase-3, Bax, and p21 and the downregulation of Bcl-2 expression. Conclusions The results of this study suggest that increased expression of STAT1 by transfection with STAT1 plasmid synergistically inhibits human U87MG glioblastoma cell growth in vitro.

scholarly journals Ethanolic Extract of Senna velutina Roots: Chemical Composition, In Vitro and In Vivo Antitumor Effects, and B16F10-Nex2 Melanoma Cell Death Mechanisms

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
David Tsuyoshi Hiramatsu Castro ◽  
Jaqueline Ferreira Campos ◽  
Marcio José Damião ◽  
Heron Fernandes Vieira Torquato ◽  
Edgar Julian Paredes-Gamero ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Chemical Composition ◽  
Caspase 3 ◽  
Tumor Volume ◽  
Apoptotic Cell ◽  
Ethanolic Extract ◽  
Antitumor Effects ◽  
Cycle Arrest

Cutaneous melanoma is among the most aggressive types of cancer, and its rate of occurrence increases every year. Current pharmacological treatments for melanoma are not completely effective, requiring the identification of new drugs. As an alternative, plant-derived natural compounds are described as promising sources of new anticancer drugs. In this context, the objectives of this study were to identify the chemical composition of the ethanolic extract of Senna velutina roots (ESVR), to assess its in vitro and in vivo antitumor effects on melanoma cells, and to characterize its mechanisms of action. For these purposes, the chemical constituents were identified by liquid chromatography coupled to high-resolution mass spectrometry. The in vitro activity of the extract was assessed in the B16F10-Nex2 melanoma cell line using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and based on the apoptotic cell count; DNA fragmentation; necrostatin-1 inhibition; intracellular calcium, pan-caspase, and caspase-3 activation; reactive oxygen species (ROS) levels; and cell cycle arrest. The in vivo activity of the extract was assessed in models of tumor volume progression and pulmonary nodule formation in C57Bl/6 mice. The chemical composition results showed that ESVR contains flavonoid derivatives of the catechin, anthraquinone, and piceatannol groups. The extract reduced B16F10-Nex2 cell viability and promoted apoptotic cell death as well as caspase-3 activation, with increased intracellular calcium and ROS levels as well as cell cycle arrest at the sub-G0/G1 phase. In vivo, the tumor volume progression and pulmonary metastasis of ESVR-treated mice decreased over 50%. Combined, these results show that ESVR had in vitro and in vivo antitumor effects, predominantly by apoptosis, thus demonstrating its potential as a therapeutic agent in the treatment of melanoma and other types of cancer.

scholarly journals Proteasome inhibition with bortezomib induces cell death in GBM stem-like cells and temozolomide-resistant glioma cell lines, but stimulates GBM stem-like cells' VEGF production and angiogenesis

2013 ◽  
Vol 119 (6) ◽  
pp. 1415-1423 ◽  
Author(s):  
Daniela A. Bota ◽  
Daniela Alexandru ◽  
Stephen T. Keir ◽  
Darell Bigner ◽  
James Vredenburgh ◽  
...  
Keyword(s):  
Cell Death ◽  
Malignant Glioma ◽  
Cell Lines ◽  
Glioma Cell ◽  
Caspase 3 ◽  
Apoptotic Cell ◽  
Malignant Gliomas ◽  
Proteasome Inhibition ◽  
Glioma Cell Lines

Object Recurrent malignant gliomas have inherent resistance to traditional chemotherapy. Novel therapies target specific molecular mechanisms involved in abnormal signaling and resistance to apoptosis. The proteasome is a key regulator of multiple cellular functions, and its inhibition in malignant astrocytic lines causes cell growth arrest and apoptotic cell death. The proteasome inhibitor bortezomib was reported to have very good in vitro activity against malignant glioma cell lines, with modest activity in animal models as well as in clinical trials as a single agent. In this paper, the authors describe the multiple effects of bortezomib in both in vitro and in vivo glioma models and offer a novel explanation for its seeming lack of activity. Methods Glioma stem-like cells (GSCs) were obtained from resected glioblastomas (GBMs) at surgery and expanded in culture. Stable glioma cell lines (U21 and D54) as well as temozolomide (TMZ)-resistant glioma cells derived from U251 and D54-MG were also cultured. GSCs from 2 different tumors, as well as D54 and U251 cells, were treated with bortezomib, and the effect of the drug was measured using an XTT cell viability assay. The activity of bortezomib was then determined in D54-MG and/or U251 cells using apoptosis analysis as well as caspase-3 activity and proteasome activity measurements. Human glioma xenograft models were created in nude mice by subcutaneous injection. Bevacizumab was administered via intraperitoneal injection at a dose of 5 mg/kg daily. Bortezomib was administered by intraperitoneal injection 1 hour after bevacizumab administration in doses of at a dose of 0.35 mg/kg on days 1, 4, 8, and 11 every 21 days. Tumors were measured twice weekly. Results Bortezomib induced caspase-3 activation and apoptotic cell death in stable glioma cell lines and in glioma stem-like cells (GSCs) derived from malignant tumor specimens Furthermore, TMZ-resistant glioma cell lines retained susceptibility to the proteasome inhibition. The bortezomib activity was directly proportional with the cells' baseline proteasome activity. The proteasome inhibition stimulated both hypoxia-inducible factor (HIF)–1α and vascular endothelial growth factor (VEGF) production in malignant GSCs. As such, the VEGF produced by GSCs stimulated endothelial cell growth, an effect that could be prevented by the addition of bevacizumab (VEGF antibody) to the media. Similarly, administration of bortezomib and bevacizumab to athymic mice carrying subcutaneous malignant glioma xenografts resulted in greater tumor inhibition and greater improvement in survival than administration of either drug alone. These data indicate that simultaneous proteasome inhibition and VEGF blockade offer increased benefit as a strategy for malignant glioma therapy. Conclusions The results of this study indicate that combination therapies based on bortezomib and bevacizumab might offer an increased benefit when the two agents are used in combination. These drugs have a complementary mechanism of action and therefore can be used together to treat TMZ-resistant malignant gliomas.

scholarly journals c-Jun N-Terminal Kinase 1 Phosphorylates Myt1 To Prevent UVA-Induced Skin Cancer

2009 ◽  
Vol 29 (8) ◽  
pp. 2168-2180 ◽  
Author(s):  
Hong Seok Choi ◽  
Ann M. Bode ◽  
Jung-Hyun Shim ◽  
Sung-Young Lee ◽  
Zigang Dong
Keyword(s):  
Skin Cancer ◽  
Caspase 3 ◽  
Ex Vivo ◽  
Apoptotic Cell ◽  
Uva Irradiation ◽  
Cellular Apoptosis ◽  
Mechanistic Basis ◽  
Induced Apoptosis ◽  
Jnk Isoforms

ABSTRACT The c-Jun N-terminal kinase (JNK) signaling pathway is known to mediate both survival and apoptosis of tumor cells. Although JNK1 and JNK2 have been shown to differentially regulate the development of skin cancer, the underlying mechanistic basis remains unclear. Here, we demonstrate that JNK1, but not JNK2, interacts with and phosphorylates Myt1 ex vivo and in vitro. UVA induces substantial apoptosis in JNK wild-type (JNK +/+) or JNK2-deficient (JNK2 −/−) mouse embryonic fibroblasts but has no effect on JNK1-deficient (JNK1 −/−) cells. In addition, UVA-induced caspase-3 cleavage and DNA fragmentation were suppressed by the knockdown of human Myt1 in skin cancer cells. JNK1 deficiency results in suppressed Myt1 phosphorylation and caspase-3 cleavage in skin exposed to UVA irradiation. In contrast, the absence of JNK2 induces Myt1 phosphorylation and caspase-3 cleavage in skin exposed to UVA. The overexpression of JNK1 with Myt1 promotes cellular apoptosis during the early embryonic development of Xenopus laevis, whereas the presence of JNK2 reduces the phenotype of Myt1-induced apoptotic cell death. Most importantly, JNK1 −/− mice developed more UVA-induced papillomas than either JNK +/+ or JNK2 −/− mice, which was associated with suppressed Myt1 phosphorylation and decreased caspase-3 cleavage. Taken together, these data provide mechanistic insights into the distinct roles of the different JNK isoforms, specifically suggesting that the JNK1-mediated phosphorylation of Myt1 plays an important role in UVA-induced apoptosis and the prevention of skin carcinogenesis.

180 DETECTION OF CASPASE-3 AND -7 IN NORMAL AND SLOW DEVELOPING BOVINE IN VITRO EMBRYOS

2006 ◽  
Vol 18 (2) ◽  
pp. 198
Author(s):  
L. Vandaele ◽  
B. Mateusen ◽  
D. Maes ◽  
A. Van Soom
Keyword(s):  
Caspase 3 ◽  
Apoptotic Cell ◽  
Laser Scanning Microscopy ◽  
Cell Stage ◽  
Important Indicator ◽  
Cell Ratio ◽  
Time Points ◽  
Positive Controls ◽  
Time Point

The incidence of apoptosis is an important indicator of embryo quality that can be measured by detection of active caspase-3 and -7 at various stages of in vitro development. The aim of the present study was to investigate the expression of these apoptotic markers in bovine in vitro embryos at different developmental stages using a fluorescent staining method. Additionally, expression of both caspases was compared between normal and slow-developing embryos. A total of 2640 immature bovine oocytes (four replicates) were matured and fertilized in vitro. Presumed zygotes (n = 2400) were denuded 24 h post-insemination (hpi) after fertilization and cultured in 50-μL droplets of modified SOF medium with 10% fetal calf serum at 39.0°C in 5% CO2, 5% O2 and 90% N2. Cleavage rate was determined at 45 hpi for all embryos, except 400 that were used as positive controls for the caspase staining. At different time points, embryos were allocated to the normal developing group if they reached the 5–8-cell stage at 45 hpi; the 9–16-cell stage at 80 hpi, the morula stage at 117 hpi and the expanded blastocyst stage or beyond at 168 hpi. Embryos that lagged one cell cycle behind at each time point were designated as slow-developing embryos. All selected embryos were stained using CaspaTag Pan-Caspase In Situ Assay kit, Fluorescein® (Chemicon International, Temecula, CA, USA). Positive controls were incubated in 0.5 μM staurosporine (Sigma, Belgium) for 24 h. The apoptotic cell ratio (ACR) was determined for each embryo by means of confocal laser scanning microscopy (ACR = number caspase-positive cells/total cell number × 100). Control embryos (n = 400) were cultured undisturbed until 168 hpi and evaluated for blastocyst yield. Mixed model analyses of variance with group as fixed factor and replicate as random factor were used to evaluate the ACR at 45, 80, 117, and 168 hpi, respectively. The mean cleavage rates at 45 hpi and the blastocyst yield at 168 hpi were 60.5% and 26.9%, respectively. The ACR over all time points and at each individual time point was significantly lower in normal-developing embryos compared with slow-developing embryos, as determined by caspase staining (P < 0.01) (Table 1). In conclusion, this study demonstrated that slow-developing embryos express a higher level of apoptosis. Further research is necessary to investigate the cause of the higher ACR in slow developing embryos, which may be the result of altered gene expression or environmental influences. Table 1. Apoptotic cell ratio (ACR; mean % ± SD) at four time points in normal and slow-developing embryos This study was supported by a grant of Research Foundation – Flanders (aspirant 1.1.084.04N00).

Caspase-3 and caspase-7 but not caspase-6 cleave Gas2 in vitro: implications for microfilament reorganization during apoptosis

1999 ◽  
Vol 112 (23) ◽  
pp. 4475-4482 ◽  
Author(s):  
A. Sgorbissa ◽  
R. Benetti ◽  
S. Marzinotto ◽  
C. Schneider ◽  
C. Brancolini
Keyword(s):  
Caspase 3 ◽  
Early Stage ◽  
Proteolytic Processing ◽  
Caspase 7 ◽  
Microfilament System ◽  
Caspase 6 ◽  
Shape Changes ◽  
Mcf 7

Apoptosis is characterized by proteolysis of specific cellular proteins by a family of cystein proteases known as caspases. Gas2, a component of the microfilament system, is cleaved during apoptosis and the cleaved form specifically regulates microfilaments and cell shape changes. We now demonstrate that Gas2 is a substrate of caspase-3 but not of caspase-6. Proteolytic processing both in vitro and in vivo is dependent on aspartic residue 279. Gas2 cleavage was only partially impaired in apoptotic MCF-7 cells which lack caspase-3, thus indicating that different caspases can process Gas2 in vivo. In vitro Gas2 was processed, albeit with low affinity, by caspase-7 thus suggesting that this caspase could be responsible for the incomplete Gas2 processing observed in UV treated MCF-7 cells. In vivo proteolysis of Gas2 was detected at an early stage of the apoptotic process when the cells are still adherent on the substrate and it was coupled to the specific rearrangement of the microfilament characterizing cell death. Finally we also demonstrated that Gas2 in vitro binds to F-actin, but this interaction was unaffected by the caspase-3 dependent proteolytic processing.

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