WorldWideScience

Sample records for underwent cell death

  1. Programmed cell death

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    The purpose of this conference to provide a multidisciplinary forum for exchange of state-of-the-art information on the role programmed cell death plays in normal development and homeostasis of many organisms. This volume contains abstracts of papers in the following areas: invertebrate development; immunology/neurology; bcl-2 family; biochemistry; programmed cell death in viruses; oncogenesis; vertebrate development; and diseases.

  2. Beneficial Effect of the Nutritional Support in Children Who Underwent Hematopoietic Stem Cell Transplant.

    Science.gov (United States)

    Koç, Nevra; Gündüz, Mehmet; Tavil, Betül; Azik, M Fatih; Coşkun, Zeynep; Yardımcı, Hülya; Uçkan, Duygu; Tunç, Bahattin

    2017-08-01

    The aim of this study was to evaluate nutritional status in children who underwent hematopoietic stem cell transplant compared with a healthy control group. A secondary aim was to utilize mid-upper arm circumference as a measure of nutritional status in these groups of children. Our study group included 40 children (18 girls, 22 boys) with mean age of 9.2 ± 4.6 years (range, 2-17 y) who underwent hematopoietic stem cell transplant. Our control group consisted of 20 healthy children (9 girls, 11 boys). The children were evaluated at admission to the hospital and followed regularly 3, 6, 9, and 12 months after discharge from the hospital. In the study group, 27 of 40 patients (67.5%) received nutritional support during hematopoietic stem cell transplant, with 15 patients (56%) receiving enteral nutrition, 6 (22%) receiving total parenteral nutrition, and 6 (22%) receiving enteral and total parenteral nutrition. Chronic malnutrition rate in the study group was 47.5% on admission to the hospital, with the control group having a rate of 20%. One year after transplant, the rate decreased to 20% in the study group and 5% in the control group. The mid-upper arm circumference was lower in children in the study group versus the control group at the beginning of the study (P groups at follow-up examinations (P > .05). During follow-up, all anthropometric measurements increased significantly in both groups. Monitoring nutritional status and initiating appropriate nutritional support improved the success of hematopoietic stem cell transplant and provided a more comfortable process during the transplant period. Furthermore, mid-upper arm circumference is a more sensitive, useful, and safer parameter that can be used to measure nutritional status of children who undergo hematopoietic stem cell transplant.

  3. Glutathione in Cancer Cell Death

    Energy Technology Data Exchange (ETDEWEB)

    Ortega, Angel L. [Department of Physiology, Faculty of Medicine and Odontology, University of Valencia, 17 Av. Blasco Ibanez, 46010 Valencia (Spain); Mena, Salvador [Green Molecular SL, Pol. Ind. La Coma-Parc Cientific, 46190 Paterna, Valencia (Spain); Estrela, Jose M., E-mail: jose.m.estrela@uv.es [Department of Physiology, Faculty of Medicine and Odontology, University of Valencia, 17 Av. Blasco Ibanez, 46010 Valencia (Spain)

    2011-03-11

    Glutathione (L-γ-glutamyl-L-cysteinyl-glycine; GSH) in cancer cells is particularly relevant in the regulation of carcinogenic mechanisms; sensitivity against cytotoxic drugs, ionizing radiations, and some cytokines; DNA synthesis; and cell proliferation and death. The intracellular thiol redox state (controlled by GSH) is one of the endogenous effectors involved in regulating the mitochondrial permeability transition pore complex and, in consequence, thiol oxidation can be a causal factor in the mitochondrion-based mechanism that leads to cell death. Nevertheless GSH depletion is a common feature not only of apoptosis but also of other types of cell death. Indeed rates of GSH synthesis and fluxes regulate its levels in cellular compartments, and potentially influence switches among different mechanisms of death. How changes in gene expression, post-translational modifications of proteins, and signaling cascades are implicated will be discussed. Furthermore, this review will finally analyze whether GSH depletion may facilitate cancer cell death under in vivo conditions, and how this can be applied to cancer therapy.

  4. Alternative Cell Death Pathways and Cell Metabolism

    Directory of Open Access Journals (Sweden)

    Simone Fulda

    2013-01-01

    Full Text Available While necroptosis has for long been viewed as an accidental mode of cell death triggered by physical or chemical damage, it has become clear over the last years that necroptosis can also represent a programmed form of cell death in mammalian cells. Key discoveries in the field of cell death research, including the identification of critical components of the necroptotic machinery, led to a revised concept of cell death signaling programs. Several regulatory check and balances are in place in order to ensure that necroptosis is tightly controlled according to environmental cues and cellular needs. This network of regulatory mechanisms includes metabolic pathways, especially those linked to mitochondrial signaling events. A better understanding of these signal transduction mechanisms will likely contribute to open new avenues to exploit our knowledge on the regulation of necroptosis signaling for therapeutic application in the treatment of human diseases.

  5. Cell Death in C. elegans Development.

    Science.gov (United States)

    Malin, Jennifer Zuckerman; Shaham, Shai

    2015-01-01

    Cell death is a common and important feature of animal development, and cell death defects underlie many human disease states. The nematode Caenorhabditis elegans has proven fertile ground for uncovering molecular and cellular processes controlling programmed cell death. A core pathway consisting of the conserved proteins EGL-1/BH3-only, CED-9/BCL2, CED-4/APAF1, and CED-3/caspase promotes most cell death in the nematode, and a conserved set of proteins ensures the engulfment and degradation of dying cells. Multiple regulatory pathways control cell death onset in C. elegans, and many reveal similarities with tumor formation pathways in mammals, supporting the idea that cell death plays key roles in malignant progression. Nonetheless, a number of observations suggest that our understanding of developmental cell death in C. elegans is incomplete. The interaction between dying and engulfing cells seems to be more complex than originally appreciated, and it appears that key aspects of cell death initiation are not fully understood. It has also become apparent that the conserved apoptotic pathway is dispensable for the demise of the C. elegans linker cell, leading to the discovery of a previously unexplored gene program promoting cell death. Here, we review studies that formed the foundation of cell death research in C. elegans and describe new observations that expand, and in some cases remodel, this edifice. We raise the possibility that, in some cells, more than one death program may be needed to ensure cell death fidelity. © 2015 Elsevier Inc. All rights reserved.

  6. Polycation-mediated integrated cell death processes

    DEFF Research Database (Denmark)

    Parhamifar, Ladan; Andersen, Helene; Wu, Linping

    2014-01-01

    standard. PEIs are highly efficient transfectants, but depending on their architecture and size they induce cytotoxicity through different modes of cell death pathways. Here, we briefly review dynamic and integrated cell death processes and pathways, and discuss considerations in cell death assay design...

  7. [Methuosis: a novel type of cell death].

    Science.gov (United States)

    Cai, Hongbing; Liu, Jinkun; Fan, Qin; Li, Xin

    2013-12-01

    Cell death is a major physiological or pathological phenomenon in life activities. The classic forms of cell death include apoptosis, necrosis, and autophagy. Recently, a novel type of cell death has been observed and termed as methuosis, in which excessive stimuli can induce cytoplasmic uptake and accumulation of small bubbles that gradually merge into giant vacuoles, eventually leading to decreased cellular metabolic activity, cell membrane rupture and cell death. In this article, we describe the nomenclature, morphological characteristics and underlying mechanisms of methuosis, compare methuosis with autophagy, oncosis and paraptosis, and review the related researches.

  8. Percentages of NKT cells in the tissues of patients with non-small cell lung cancer who underwent surgical treatment.

    Science.gov (United States)

    Pyszniak, Maria; Rybojad, Paweł; Pogoda, Katarzyna; Jabłonka, Andrzej; Bojarska-Junak, Agnieszka; Tabarkiewicz, Jacek

    2014-03-01

    Natural killer T (NKT) cells are involved in the antitumor response by direct cytotoxicity and indirectly through activation of effector cells. Recent studies have shown a relationship between the number and function of NKT cells and clinical outcomes. NKT cells seem to represent a promising tool for immunotherapy of cancer. The aim of the study was to evaluate the distribution of NKT cells in peripheral blood, lymph nodes and tumor tissue of non-small cell lung cancer (NSCLC) patients, as well as development of the most efficient set of cytokines stimulating differentiation of NKT cells. We evaluated the percentage of iNKT+CD3+ cells in the tissues collected from patients with NSCLC. For the generation of NKT cells, we cultured cells isolated from the blood of 20 healthy donors and from the tissues of 4 NSCLC patients. Cells were stimulated with α-GalCer in combinations with cytokines. We noted significant differences in the percentages of NKT cells in the patients' tissues. The highest percentage of these cells was observed in the tumor tissue and the lowest in the lymph nodes. In vitro, in healthy donors all α-GalCer-cytokine combinations were effective in stimulation of NKT cells' proliferation. NKT cells' proliferation was the most efficiently stimulated by α-GalCer+IL-2+IL-7 and α-GalCer+IL-2+IFN-γ. Our results suggest that in the course of NSCLC, NKT cells migrate to the primary tumor and accumulate therein. All tested combinations of α-GalCer and cytokines were capable of generation of NKT cells in vitro.

  9. Nonthermal-plasma-mediated animal cell death

    Science.gov (United States)

    Kim, Wanil; Woo, Kyung-Chul; Kim, Gyoo-Cheon; Kim, Kyong-Tai

    2011-01-01

    Animal cell death comprising necrosis and apoptosis occurred in a well-regulated manner upon specific stimuli. The physiological meanings and detailed molecular mechanisms of cell death have been continuously investigated over several decades. Necrotic cell death has typical morphological changes, such as cell swelling and cell lysis followed by DNA degradation, whereas apoptosis shows blebbing formation and regular DNA fragmentation. Cell death is usually adopted to terminate cancer cells in vivo. The current strategies against tumour are based on the induction of cell death by adopting various methods, including radiotherapy and chemotherapeutics. Among these, radiotherapy is the most frequently used treatment method, but it still has obvious limitations. Recent studies have suggested that the use of nonthermal air plasma can be a prominent method for inducing cancer cell death. Plasma-irradiated cells showed the loss of genomic integrity, mitochondrial dysfunction, plasma membrane damage, etc. Tumour elimination with plasma irradiation is an emerging concept in cancer therapy and can be accelerated by targeting certain tumour-specific proteins with gold nanoparticles. Here, some recent developments are described so that the mechanisms related to plasma-mediated cell death and its perspectives in cancer treatment can be understood.

  10. Nonthermal-plasma-mediated animal cell death

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Wanil; Woo, Kyung-Chul; Kim, Kyong-Tai [Department of Life Science, Division of Molecular and Life Science, Pohang University of Science and Technology, San 31, Hyoja Dong, Pohang 790-784 (Korea, Republic of); Kim, Gyoo-Cheon, E-mail: ktk@postech.ac.kr [Department of Oral Anatomy and Cell Biology, School of Dentistry, Pusan National University, Yangsan 626-810 (Korea, Republic of)

    2011-01-12

    Animal cell death comprising necrosis and apoptosis occurred in a well-regulated manner upon specific stimuli. The physiological meanings and detailed molecular mechanisms of cell death have been continuously investigated over several decades. Necrotic cell death has typical morphological changes, such as cell swelling and cell lysis followed by DNA degradation, whereas apoptosis shows blebbing formation and regular DNA fragmentation. Cell death is usually adopted to terminate cancer cells in vivo. The current strategies against tumour are based on the induction of cell death by adopting various methods, including radiotherapy and chemotherapeutics. Among these, radiotherapy is the most frequently used treatment method, but it still has obvious limitations. Recent studies have suggested that the use of nonthermal air plasma can be a prominent method for inducing cancer cell death. Plasma-irradiated cells showed the loss of genomic integrity, mitochondrial dysfunction, plasma membrane damage, etc. Tumour elimination with plasma irradiation is an emerging concept in cancer therapy and can be accelerated by targeting certain tumour-specific proteins with gold nanoparticles. Here, some recent developments are described so that the mechanisms related to plasma-mediated cell death and its perspectives in cancer treatment can be understood. (topical review)

  11. Nonthermal-plasma-mediated animal cell death

    International Nuclear Information System (INIS)

    Kim, Wanil; Woo, Kyung-Chul; Kim, Kyong-Tai; Kim, Gyoo-Cheon

    2011-01-01

    Animal cell death comprising necrosis and apoptosis occurred in a well-regulated manner upon specific stimuli. The physiological meanings and detailed molecular mechanisms of cell death have been continuously investigated over several decades. Necrotic cell death has typical morphological changes, such as cell swelling and cell lysis followed by DNA degradation, whereas apoptosis shows blebbing formation and regular DNA fragmentation. Cell death is usually adopted to terminate cancer cells in vivo. The current strategies against tumour are based on the induction of cell death by adopting various methods, including radiotherapy and chemotherapeutics. Among these, radiotherapy is the most frequently used treatment method, but it still has obvious limitations. Recent studies have suggested that the use of nonthermal air plasma can be a prominent method for inducing cancer cell death. Plasma-irradiated cells showed the loss of genomic integrity, mitochondrial dysfunction, plasma membrane damage, etc. Tumour elimination with plasma irradiation is an emerging concept in cancer therapy and can be accelerated by targeting certain tumour-specific proteins with gold nanoparticles. Here, some recent developments are described so that the mechanisms related to plasma-mediated cell death and its perspectives in cancer treatment can be understood. (topical review)

  12. Molecular mechanisms of cell death: recommendations of the Nomenclature Committee on Cell Death 2018

    OpenAIRE

    Galluzzi, L; Vitale, I; Aaronson, Sa; Abrams, Jm; Adam, D; Agostinis, P; Alnemri, Es; Altucci, L; Amelio, I; Andrews, Dw; Annicchiarico-Petruzzelli, M; Antonov, Av; Arama, E; Baehrecke, Eh; Barlev, Na

    2018-01-01

    Over the past decade, the Nomenclature Committee on Cell Death (NCCD) has formulated guidelines for the definition and interpretation of cell death from morphological, biochemical, and functional perspectives. Since the field continues to expand and novel mechanisms that orchestrate multiple cell death pathways are unveiled, we propose an updated classification of cell death subroutines focusing on mechanistic and essential (as opposed to correlative and dispensable) aspects of the process. A...

  13. Endoplasmic reticulum involvement in yeast cell death

    International Nuclear Information System (INIS)

    Nicanor Austriaco, O.

    2012-01-01

    Yeast cells undergo programed cell death (PCD) with characteristic markers associated with apoptosis in mammalian cells including chromatin breakage, nuclear fragmentation, reactive oxygen species generation, and metacaspase activation. Though significant research has focused on mitochondrial involvement in this phenomenon, more recent work with both Saccharomyces cerevisiae and Schizosaccharomyces pombe has also implicated the endoplasmic reticulum (ER) in yeast PCD. This minireview provides an overview of ER stress-associated cell death (ER-SAD) in yeast. It begins with a description of ER structure and function in yeast before moving to a discussion of ER-SAD in both mammalian and yeast cells. Three examples of yeast cell death associated with the ER will be highlighted here including inositol starvation, lipid toxicity, and the inhibition of N-glycosylation. It closes by suggesting ways to further examine the involvement of the ER in yeast cell death.

  14. Lysosomal cell death at a glance

    DEFF Research Database (Denmark)

    Aits, Sonja; Jaattela, Marja

    2013-01-01

    Lysosomes serve as the cellular recycling centre and are filled with numerous hydrolases that can degrade most cellular macromolecules. Lysosomal membrane permeabilization and the consequent leakage of the lysosomal content into the cytosol leads to so-called "lysosomal cell death". This form...... of cell death is mainly carried out by the lysosomal cathepsin proteases and can have necrotic, apoptotic or apoptosis-like features depending on the extent of the leakage and the cellular context. This article summarizes our current knowledge on lysosomal cell death with an emphasis on the upstream...... mechanisms that lead to lysosomal membrane permeabilization....

  15. Morphological classification of plant cell deaths

    DEFF Research Database (Denmark)

    van Doorn, W.G.; Beers, E.P.; Dangl, J.L.

    2011-01-01

    , which can express features of both necrosis and vacuolar cell death, PCD in starchy cereal endosperm and during self-incompatibility. The present classification is not static, but will be subject to further revision, especially when specific biochemical pathways are better defined....... the classification of PCD in plants. Here we suggest a classification based on morphological criteria. According to this classification, the use of the term 'apoptosis' is not justified in plants, but at least two classes of PCD can be distinguished: vacuolar cell death and necrosis. During vacuolar cell death...

  16. Morphological classification of plant cell deaths.

    Science.gov (United States)

    van Doorn, W G; Beers, E P; Dangl, J L; Franklin-Tong, V E; Gallois, P; Hara-Nishimura, I; Jones, A M; Kawai-Yamada, M; Lam, E; Mundy, J; Mur, L A J; Petersen, M; Smertenko, A; Taliansky, M; Van Breusegem, F; Wolpert, T; Woltering, E; Zhivotovsky, B; Bozhkov, P V

    2011-08-01

    Programmed cell death (PCD) is an integral part of plant development and of responses to abiotic stress or pathogens. Although the morphology of plant PCD is, in some cases, well characterised and molecular mechanisms controlling plant PCD are beginning to emerge, there is still confusion about the classification of PCD in plants. Here we suggest a classification based on morphological criteria. According to this classification, the use of the term 'apoptosis' is not justified in plants, but at least two classes of PCD can be distinguished: vacuolar cell death and necrosis. During vacuolar cell death, the cell contents are removed by a combination of autophagy-like process and release of hydrolases from collapsed lytic vacuoles. Necrosis is characterised by early rupture of the plasma membrane, shrinkage of the protoplast and absence of vacuolar cell death features. Vacuolar cell death is common during tissue and organ formation and elimination, whereas necrosis is typically found under abiotic stress. Some examples of plant PCD cannot be ascribed to either major class and are therefore classified as separate modalities. These are PCD associated with the hypersensitive response to biotrophic pathogens, which can express features of both necrosis and vacuolar cell death, PCD in starchy cereal endosperm and during self-incompatibility. The present classification is not static, but will be subject to further revision, especially when specific biochemical pathways are better defined.

  17. Demographic And Technical Risk Factors Of 30-Day Stroke, Myocardial Infarction, And/Or Death In Standard And High Risk Patients Who Underwent Carotid Angioplasty And Stenting

    Directory of Open Access Journals (Sweden)

    Samaneh Yousefi

    2017-02-01

    Full Text Available Background: Carotid angioplasty and stenting (CAS is an accepted treatment to prevent stroke in patients with carotid artery stenosis. The purpose of this study is to identify risk factors for major complications after carotid angioplasty and stenting. Methods and Material: This is a prospective study conducted at Shiraz University of Medical Sciences in southern Iran from March 2011 to June 2014. Consecutive patients undergoing carotid angioplasty and stenting were enrolled. Both standard risk and high risk patients for endarterectomy were enrolled. Demographic data, atherosclerotic risk factors, site of stenosis, degree of stenosis, and data regarding technical factors were recorded. 30-day stroke, myocardial infarction, and/or death were considered as the composite primary outcome of the study. Results:  two hundred and fifty one patients were recruited (mean age: 71.1+ 9.6 years, male: 65.3%.  One hundred and seventy eight (70.9% patients were symptomatic; 73 (29.1%, 129 (51.4%, 165 (65.7% and 62 (24.7% patients were diabetic, hyperlipidemic, hypertensive and smoker respectively. CAS performed for left ICA in 113 (45.4% patients. 14 (5.6% patients had Sequential bilateral stenting. Mean stenosis of operated ICA was 80.2 +13.8 %. Embolic protection device was used in 203 (96.2% patients. Predilation and post-dilation were performed in 39 (18.5% and 182 (86.3% patients respectively. Composite outcome was observed in 3.6% (3.2% stroke, 0% myocardial infarction and 1.2% death. Left sided lesions and presence of DM was significantly associated with poor short term outcome. (P value: 0.025 and 0.020, respectively Conclusion: There was a higher risk of short term major complications in diabetic patients and left carotid artery intervention.

  18. Cell death in Pseudomonas aeruginosa biofilm development

    DEFF Research Database (Denmark)

    Webb, J.S.; Thompson, L.S.; James, S.

    2003-01-01

    Bacteria growing in biofilms often develop multicellular, three-dimensional structures known as microcolonies. Complex differentiation within biofilms of Pseudomonas aeruginosa occurs, leading to the creation of voids inside microcolonies and to the dispersal of cells from within these voids....... However, key developmental processes regulating these events are poorly understood. A normal component of multicellular development is cell death. Here we report that a repeatable pattern of cell death and lysis occurs in biofilms of P. aeruginosa during the normal course of development. Cell death...... occurred with temporal and spatial organization within biofilms, inside microcolonies, when the biofilms were allowed to develop in continuous-culture flow cells. A subpopulation of viable cells was always observed in these regions. During the onset of biofilm killing and during biofilm development...

  19. Molecular mechanisms of cell death: recommendations of the Nomenclature Committee on Cell Death 2018

    NARCIS (Netherlands)

    Galluzzi, Lorenzo; Vitale, Ilio; Aaronson, Stuart A.; Abrams, John M.; Adam, Dieter; Agostinis, Patrizia; Alnemri, Emad S.; Altucci, Lucia; Amelio, Ivano; Andrews, David W.; Annicchiarico-Petruzzelli, Margherita; Antonov, Alexey V.; Arama, Eli; Baehrecke, Eric H.; Barlev, Nickolai A.; Bazan, Nicolas G.; Bernassola, Francesca; Bertrand, Mathieu J. M.; Bianchi, Katiuscia; Blagosklonny, Mikhail V.; Blomgren, Klas; Borner, Christoph; Boya, Patricia; Brenner, Catherine; Campanella, Michelangelo; Candi, Eleonora; Carmona-Gutierrez, Didac; Cecconi, Francesco; Chan, Francis K.-M.; Chandel, Navdeep S.; Cheng, Emily H.; Chipuk, Jerry E.; Cidlowski, John A.; Ciechanover, Aaron; Cohen, Gerald M.; Conrad, Marcus; Cubillos-Ruiz, Juan R.; Czabotar, Peter E.; D'Angiolella, Vincenzo; Dawson, Ted M.; Dawson, Valina L.; de Laurenzi, Vincenzo; de Maria, Ruggero; Debatin, Klaus-Michael; DeBerardinis, Ralph J.; Deshmukh, Mohanish; Di Daniele, Nicola; Di Virgilio, Francesco; Dixit, Vishva M.; Dixon, Scott J.; Duckett, Colin S.; Dynlacht, Brian D.; El-Deiry, Wafik S.; Elrod, John W.; Fimia, Gian Maria; Fulda, Simone; García-Sáez, Ana J.; Garg, Abhishek D.; Garrido, Carmen; Gavathiotis, Evripidis; Golstein, Pierre; Gottlieb, Eyal; Green, Douglas R.; Greene, Lloyd A.; Gronemeyer, Hinrich; Gross, Atan; Hajnoczky, Gyorgy; Hardwick, J. Marie; Harris, Isaac S.; Hengartner, Michael O.; Hetz, Claudio; Ichijo, Hidenori; Jäättelä, Marja; Joseph, Bertrand; Jost, Philipp J.; Juin, Philippe P.; Kaiser, William J.; Karin, Michael; Kaufmann, Thomas; Kepp, Oliver; Kimchi, Adi; Kitsis, Richard N.; Klionsky, Daniel J.; Knight, Richard A.; Kumar, Sharad; Lee, Sam W.; Lemasters, John J.; Levine, Beth; Linkermann, Andreas; Lipton, Stuart A.; Lockshin, Richard A.; López-Otín, Carlos; Lowe, Scott W.; Luedde, Tom; Lugli, Enrico; MacFarlane, Marion; Madeo, Frank; Malewicz, Michal; Malorni, Walter; Manic, Gwenola; Marine, Jean-Christophe; Martin, Seamus J.; Martinou, Jean-Claude; Medema, Jan Paul; Mehlen, Patrick; Meier, Pascal; Melino, Sonia; Miao, Edward A.; Molkentin, Jeffery D.; Moll, Ute M.; Muñoz-Pinedo, Cristina; Nagata, Shigekazu; Nuñez, Gabriel; Oberst, Andrew; Oren, Moshe; Overholtzer, Michael; Pagano, Michele; Panaretakis, Theocharis; Pasparakis, Manolis; Penninger, Josef M.; Pereira, David M.; Pervaiz, Shazib; Peter, Marcus E.; Piacentini, Mauro; Pinton, Paolo; Prehn, Jochen H. M.; Puthalakath, Hamsa; Rabinovich, Gabriel A.; Rehm, Markus; Rizzuto, Rosario; Rodrigues, Cecilia M. P.; Rubinsztein, David C.; Rudel, Thomas; Ryan, Kevin M.; Sayan, Emre; Scorrano, Luca; Shao, Feng; Shi, Yufang; Silke, John; Simon, Hans-Uwe; Sistigu, Antonella; Stockwell, Brent R.; Strasser, Andreas; Szabadkai, Gyorgy; Tait, Stephen W. G.; Tang, Daolin; Tavernarakis, Nektarios; Thorburn, Andrew; Tsujimoto, Yoshihide; Turk, Boris; Vanden Berghe, Tom; Vandenabeele, Peter; Vander Heiden, Matthew G.; Villunger, Andreas; Virgin, Herbert W.; Vousden, Karen H.; Vucic, Domagoj; Wagner, Erwin F.; Walczak, Henning; Wallach, David; Wang, Ying; Wells, James A.; Wood, Will; Yuan, Junying; Zakeri, Zahra; Zhivotovsky, Boris; Zitvogel, Laurence; Melino, Gerry; Kroemer, Guido

    2018-01-01

    Over the past decade, the Nomenclature Committee on Cell Death (NCCD) has formulated guidelines for the definition and interpretation of cell death from morphological, biochemical, and functional perspectives. Since the field continues to expand and novel mechanisms that orchestrate multiple cell

  20. Drosophila Ninjurin A induces nonapoptotic cell death.

    Directory of Open Access Journals (Sweden)

    Sarah Broderick

    Full Text Available Ninjurins are conserved transmembrane proteins that are upregulated across species in response to injury and stress. Their biological functions are not understood, in part because there have been few in vivo studies of their function. We analyzed the expression and function of one of three Drosophila Ninjurins, NijA. We found that NijA protein is redistributed to the cell surface in larval immune tissues after septic injury and is upregulated by the Toll pathway. We generated a null mutant of NijA, which displayed no detectable phenotype. In ectopic expression studies, NijA induced cell death, as evidenced by cell loss and acridine orange staining. These dying cells did not display hallmarks of apoptotic cells including TUNEL staining and inhibition by p35, indicating that NijA induced nonapoptotic cell death. In cell culture, NijA also induced cell death, which appeared to be cell autonomous. These in vivo studies identify a new role for the Ninjurin family in inducing nonapoptotic cell death.

  1. Epidermal cell death in frogs with chytridiomycosis

    Directory of Open Access Journals (Sweden)

    Laura A. Brannelly

    2017-02-01

    Full Text Available Background Amphibians are declining at an alarming rate, and one of the major causes of decline is the infectious disease chytridiomycosis. Parasitic fungal sporangia occur within epidermal cells causing epidermal disruption, but these changes have not been well characterised. Apoptosis (planned cell death can be a damaging response to the host but may alternatively be a mechanism of pathogen removal for some intracellular infections. Methods In this study we experimentally infected two endangered amphibian species Pseudophryne corroboree and Litoria verreauxii alpina with the causal agent of chytridiomycosis. We quantified cell death in the epidermis through two assays: terminal transferase-mediated dUTP nick end-labelling (TUNEL and caspase 3/7. Results Cell death was positively associated with infection load and morbidity of clinically infected animals. In infected amphibians, TUNEL positive cells were concentrated in epidermal layers, correlating to the localisation of infection within the skin. Caspase activity was stable and low in early infection, where pathogen loads were light but increasing. In animals that recovered from infection, caspase activity gradually returned to normal as the infection cleared. Whereas, in amphibians that did not recover, caspase activity increased dramatically when infection loads peaked. Discussion Increased cell death may be a pathology of the fungal parasite, likely contributing to loss of skin homeostatic functions, but it is also possible that apoptosis suppression may be used initially by the pathogen to help establish infection. Further research should explore the specific mechanisms of cell death and more specifically apoptosis regulation during fungal infection.

  2. Induction of apoptotic cell death by putrescine

    DEFF Research Database (Denmark)

    Takao, Koichi; Rickhag, Karl Mattias; Hegardt, Cecilia

    2006-01-01

    that overexpression of a metabolically stable ODC in CHO cells induced a massive cell death unless the cells were grown in the presence of the ODC inhibitor alpha-difluoromethylornithine (DFMO). Cells overexpressing wild-type (unstable) ODC, on the other hand, were not dependent on the presence of DFMO...... for their growth. The induction of cell death was correlated with a dramatic increase in cellular putrescine levels. Analysis using flow cytometry revealed perturbed cell cycle kinetics, with a large accumulation of cells with sub-G1 amounts of DNA, which is a typical sign of apoptosis. Another strong indication...... of apoptosis was the finding that one of the key enzymes in the apoptotic process, caspase-3, was induced when DFMO was omitted from the growth medium. Furthermore, inhibition of the caspase activity significantly reduced the recruitment of cells to the sub-G1 fraction. In conclusion, deregulation of polyamine...

  3. Presence of Donor-Derived DNA in Semen Samples From Cancer Survivors Who Underwent Donor Stem Cell Transplant

    Science.gov (United States)

    2014-12-08

    Cancer Survivor; Chronic Myeloproliferative Disorders; Leukemia; Lymphoma; Multiple Myeloma and Plasma Cell Neoplasm; Myelodysplastic Syndromes; Myelodysplastic/Myeloproliferative Neoplasms; Neuroblastoma; Testicular Germ Cell Tumor

  4. How Kidney Cell Death Induces Renal Necroinflammation.

    Science.gov (United States)

    Mulay, Shrikant R; Kumar, Santhosh V; Lech, Maciej; Desai, Jyaysi; Anders, Hans-Joachim

    2016-05-01

    The nephrons of the kidney are independent functional units harboring cells of a low turnover during homeostasis. As such, physiological renal cell death is a rather rare event and dead cells are flushed away rapidly with the urinary flow. Renal cell necrosis occurs in acute kidney injuries such as thrombotic microangiopathies, necrotizing glomerulonephritis, or tubular necrosis. All of these are associated with intense intrarenal inflammation, which contributes to further renal cell loss, an autoamplifying process referred to as necroinflammation. But how does renal cell necrosis trigger inflammation? Here, we discuss the role of danger-associated molecular patterns (DAMPs), mitochondrial (mito)-DAMPs, and alarmins, as well as their respective pattern recognition receptors. The capacity of DAMPs and alarmins to trigger cytokine and chemokine release initiates the recruitment of leukocytes into the kidney that further amplify necroinflammation. Infiltrating neutrophils often undergo neutrophil extracellular trap formation associated with neutrophil death or necroptosis, which implies a release of histones, which act not only as DAMPs but also elicit direct cytotoxic effects on renal cells, namely endothelial cells. Proinflammatory macrophages and eventually cytotoxic T cells further drive kidney cell death and inflammation. Dissecting the molecular mechanisms of necroinflammation may help to identify the best therapeutic targets to limit nephron loss in kidney injury. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Effects of intracellular iron overload on cell death and identification of potent cell death inhibitors.

    Science.gov (United States)

    Fang, Shenglin; Yu, Xiaonan; Ding, Haoxuan; Han, Jianan; Feng, Jie

    2018-06-11

    Iron overload causes many diseases, while the underlying etiologies of these diseases are unclear. Cell death processes including apoptosis, necroptosis, cyclophilin D-(CypD)-dependent necrosis and a recently described additional form of regulated cell death called ferroptosis, are dependent on iron or iron-dependent reactive oxygen species (ROS). However, whether the accumulation of intracellular iron itself induces ferroptosis or other forms of cell death is largely elusive. In present study, we study the role of intracellular iron overload itself-induced cell death mechanisms by using ferric ammonium citrate (FAC) and a membrane-permeable Ferric 8-hydroxyquinoline complex (Fe-8HQ) respectively. We show that FAC-induced intracellular iron overload causes ferroptosis. We also identify 3-phosphoinositide-dependent kinase 1 (PDK1) inhibitor GSK2334470 as a potent ferroptosis inhibitor. Whereas, Fe-8HQ-induced intracellular iron overload causes unregulated necrosis, but partially activates PARP-1 dependent parthanatos. Interestingly, we identify many phenolic compounds as potent inhibitors of Fe-8HQ-induced cell death. In conclusion, intracellular iron overload-induced cell death form might be dependent on the intracellular iron accumulation rate, newly identified cell death inhibitors in our study that target ferroptosis and unregulated oxidative cell death represent potential therapeutic strategies against iron overload related diseases. Copyright © 2018 Elsevier Inc. All rights reserved.

  6. Reasons of reproductive death of mammalian cells

    International Nuclear Information System (INIS)

    Obaturov, G.M.

    1988-01-01

    According to its functional-structural organization the cell is rather a difficult object. It contains many various components, which essentially differ from the another according to their significance for its normal functioning, as well as sizes and number. When analyzing damage different types in cell sensitive target, that is - DNA, the author concludes, that it is most probable, that chromosomal aberrations are, mainly the reasons of cell reproduction death, rather than DNA unrepaired breaks

  7. The regulation of apoptotic cell death

    Directory of Open Access Journals (Sweden)

    Amarante-Mendes G.P.

    1999-01-01

    Full Text Available Apoptosis is a fundamental biological phenomenon in which the death of a cell is genetically and biochemically regulated. Different molecules are involved in the regulation of the apoptotic process. Death receptors, coupled to distinct members of the caspases as well as other adapter molecules, are involved in the initiation of the stress signals (The Indictment. Members of the Bcl-2 family control at the mitochondrial level the decision between life and death (The Judgement. The effector caspases are responsible for all morphological and biochemical changes related to apoptosis including the "eat-me" signals perceived by phagocytes and neighboring cells (The Execution. Finally, apoptosis would have little biological significance without the recognition and removal of the dying cells (The Burial.

  8. Mycobacterium tuberculosis infection induces non-apoptotic cell death of human dendritic cells

    LENUS (Irish Health Repository)

    Ryan, Ruth CM

    2011-10-24

    Abstract Background Dendritic cells (DCs) connect innate and adaptive immunity, and are necessary for an efficient CD4+ and CD8+ T cell response after infection with Mycobacterium tuberculosis (Mtb). We previously described the macrophage cell death response to Mtb infection. To investigate the effect of Mtb infection on human DC viability, we infected these phagocytes with different strains of Mtb and assessed viability, as well as DNA fragmentation and caspase activity. In parallel studies, we assessed the impact of infection on DC maturation, cytokine production and bacillary survival. Results Infection of DCs with live Mtb (H37Ra or H37Rv) led to cell death. This cell death proceeded in a caspase-independent manner, and without nuclear fragmentation. In fact, substrate assays demonstrated that Mtb H37Ra-induced cell death progressed without the activation of the executioner caspases, 3\\/7. Although the death pathway was triggered after infection, the DCs successfully underwent maturation and produced a host-protective cytokine profile. Finally, dying infected DCs were permissive for Mtb H37Ra growth. Conclusions Human DCs undergo cell death after infection with live Mtb, in a manner that does not involve executioner caspases, and results in no mycobactericidal effect. Nonetheless, the DC maturation and cytokine profile observed suggests that the infected cells can still contribute to TB immunity.

  9. Inducible cell death in plant immunity

    DEFF Research Database (Denmark)

    Hofius, Daniel; Tsitsigiannis, Dimitrios I; Jones, Jonathan D G

    2006-01-01

    Programmed cell death (PCD) occurs during vegetative and reproductive plant growth, as typified by autumnal leaf senescence and the terminal differentiation of the endosperm of cereals which provide our major source of food. PCD also occurs in response to environmental stress and pathogen attack......, and these inducible PCD forms are intensively studied due their experimental tractability. In general, evidence exists for plant cell death pathways which have similarities to the apoptotic, autophagic and necrotic forms described in yeast and metazoans. Recent research aiming to understand these pathways...

  10. Ionizing radiation-induced cell death

    International Nuclear Information System (INIS)

    Szumiel, I.

    1994-01-01

    Selected aspects of radiation-induced cell death, connected with signal transduction pathways are reviewed. Cell death is defined as insufficiency of the cellular signal transducing system to maintain the cell's physiological functions. The insufficiency may be due to impaired signal reception and/or transduction, lack or erroneous transcription activation, and eventual cellular ''misexpression'' of the signal. The molecular basis of this insufficiency would be damage to genomic (but also other cellular) structures and closing of specific signalling pathways or opening of others (like those leading to apoptosis). I describe experimental data that suggest an important role of RAS/NFI and p53/p105 Rb proteins in cell cycle control-coupled responses to DNA damage. (Author)

  11. Nanomaterials Toxicity and Cell Death Modalities

    Directory of Open Access Journals (Sweden)

    Daniela De Stefano

    2012-01-01

    Full Text Available In the last decade, the nanotechnology advancement has developed a plethora of novel and intriguing nanomaterial application in many sectors, including research and medicine. However, many risks have been highlighted in their use, particularly related to their unexpected toxicity in vitro and in vivo experimental models. This paper proposes an overview concerning the cell death modalities induced by the major nanomaterials.

  12. Morphological classification of plant cell deaths

    NARCIS (Netherlands)

    Doorn, van W.G.; Beers, E.P.; Dangl, J.L.; Franklin-Tong, V.E.; Woltering, E.J.

    2011-01-01

    Programmed cell death (PCD) is an integral part of plant development and of responses to abiotic stress or pathogens. Although the morphology of plant PCD is, in some cases, well characterised and molecular mechanisms controlling plant PCD are beginning to emerge, there is still confusion about the

  13. Prognostic significance of nuclear factor of activated T-cells 5 expression in non-small cell lung cancer patients who underwent surgical resection.

    Science.gov (United States)

    Cho, Hyun Jin; Yun, Hwan-Jung; Yang, Hee Chul; Kim, Soo Jin; Kang, Shin Kwang; Che, Chengri; Lee, Sang Do; Kang, Min-Woong

    2018-06-01

    Nuclear factor of activated T-cells 5 (NFAT5) is known to be correlated with migration or invasion of tumor cells based on previous in vitro studies. The aim of this study was to analyze the relationship between NFAT5 expression and clinical prognosis in non-small cell lung cancer (NSCLC) patients who underwent surgical resection. A total of 92 NSCLC patients who underwent surgical resection were enrolled. The tissue microarray core was obtained from surgically resected tumor specimens. NFAT5 expression was evaluated by immunohistochemistry. Relationships of NFAT5 expression with disease recurrence, overall survival, and disease-free survival (DFS) were analyzed. The mean age of 92 patients was 63.7 y. The median follow-up duration was 63.3 mo. Fifty-one (55%) patients exhibited positive expression of NFAT5. Disease recurrence in the NFAT5-positive group was significantly (P = 0.022) higher than that in the NFAT5-negative group. NFAT5-positive expression (odds ratio: 2.632, 95% confidence interval: 1.071-6.465, P = 0.035) and pathologic N stage (N1-2 versus N0; odds ratio: 3.174, 95% confidence interval: 1.241-8.123, P = 0.016) were independent and significant risk factors for disease recurrence. DFS of the NFAT5-positive group was significantly worse than that of the NFAT5-negative group (89.7 versus 48.7 mo, P = 0.011). A multivariate analysis identified NFAT5 expression (P < 0.029) as a significant independent risk factor for DFS of patients with postoperative pathologic T and N stages (P < 0.001 and P = 0.017, respectively). NFAT5 expression is a useful prognostic biomarker for NSCLC patients who underwent surgical resection. Copyright © 2018 Elsevier Inc. All rights reserved.

  14. Mitochondrial fission proteins regulate programmed cell death in yeast

    OpenAIRE

    Fannjiang, Yihru; Cheng, Wen-Chih; Lee, Sarah J.; Qi, Bing; Pevsner, Jonathan; McCaffery, J. Michael; Hill, R. Blake; Basañez, Gorka; Hardwick, J. Marie

    2004-01-01

    The possibility that single-cell organisms undergo programmed cell death has been questioned in part because they lack several key components of the mammalian cell death machinery. However, yeast encode a homolog of human Drp1, a mitochondrial fission protein that was shown previously to promote mammalian cell death and the excessive mitochondrial fragmentation characteristic of apoptotic mammalian cells. In support of a primordial origin of programmed cell death involving mitochondria, we fo...

  15. Programmed cell death during quinoa perisperm development.

    Science.gov (United States)

    López-Fernández, María Paula; Maldonado, Sara

    2013-08-01

    At seed maturity, quinoa (Chenopodium quinoa Willd.) perisperm consists of uniform, non-living, thin-walled cells full of starch grains. The objective of the present study was to study quinoa perisperm development and describe the programme of cell death that affects the entire tissue. A number of parameters typically measured during programmed cell death (PCD), such as cellular morphological changes in nuclei and cytoplasm, endoreduplication, DNA fragmentation, and the participation of nucleases and caspase-like proteases in nucleus dismantling, were evaluated; morphological changes in cytoplasm included subcellular aspects related to starch accumulation. This study proved that, following fertilization, the perisperm of quinoa simultaneously accumulates storage reserves and degenerates, both processes mediated by a programme of developmentally controlled cell death. The novel findings regarding perisperm development provide a starting point for further research in the Amaranthaceae genera, such as comparing seeds with and without perisperm, and specifying phylogeny and evolution within this taxon. Wherever possible and appropriate, differences between quinoa perisperm and grass starchy endosperm--a morphologically and functionally similar, although genetically different tissue--were highlighted and discussed.

  16. UV-Induced Cell Death in Plants

    Science.gov (United States)

    Nawkar, Ganesh M.; Maibam, Punyakishore; Park, Jung Hoon; Sahi, Vaidurya Pratap; Lee, Sang Yeol; Kang, Chang Ho

    2013-01-01

    Plants are photosynthetic organisms that depend on sunlight for energy. Plants respond to light through different photoreceptors and show photomorphogenic development. Apart from Photosynthetically Active Radiation (PAR; 400–700 nm), plants are exposed to UV light, which is comprised of UV-C (below 280 nm), UV-B (280–320 nm) and UV-A (320–390 nm). The atmospheric ozone layer protects UV-C radiation from reaching earth while the UVR8 protein acts as a receptor for UV-B radiation. Low levels of UV-B exposure initiate signaling through UVR8 and induce secondary metabolite genes involved in protection against UV while higher dosages are very detrimental to plants. It has also been reported that genes involved in MAPK cascade help the plant in providing tolerance against UV radiation. The important targets of UV radiation in plant cells are DNA, lipids and proteins and also vital processes such as photosynthesis. Recent studies showed that, in response to UV radiation, mitochondria and chloroplasts produce a reactive oxygen species (ROS). Arabidopsis metacaspase-8 (AtMC8) is induced in response to oxidative stress caused by ROS, which acts downstream of the radical induced cell death (AtRCD1) gene making plants vulnerable to cell death. The studies on salicylic and jasmonic acid signaling mutants revealed that SA and JA regulate the ROS level and antagonize ROS mediated cell death. Recently, molecular studies have revealed genes involved in response to UV exposure, with respect to programmed cell death (PCD). PMID:23344059

  17. Cell death induced by hydroxyapatite on L929 fibroblast cells.

    Science.gov (United States)

    Inayat-Hussain, S H; Rajab, N F; Roslie, H; Hussin, A A; Ali, A M; Annuar, B O

    2004-05-01

    Biomaterials intended for end-use application as bone-graft substitutes have to undergo safety evaluation. In this study, we investigated the in vitro cytotoxic effects especially to determine the mode of death of two hydroxyapatite compounds (HA2, HA3) which were synthesized locally. The methods used for cytotoxicity was the standard MTT assay whereas AO/PI staining was performed to determine the mode of cell death in HA treated L929 fibroblasts. Our results demonstrated that both HA2 and HA3 were not significantly cytotoxic as more than 75% cells after 72 hours treatment were viable. Furthermore, we found that the major mode of cell death in HA treated cells was apoptosis. In conclusion, our results demonstrated that these hydroxyapatite compounds are not cytotoxic where the mode of death was primarily via apoptosis.

  18. Studying apoptotic cell death by flow cytometry

    International Nuclear Information System (INIS)

    Ormerod, Michael G.

    1998-01-01

    Full text: Programmed cell death (PCD) is of fundamental importance in the normal development of an animal and also in tumour biology and radiation biology. During PCD a sequence of changes occurs in cells giving rise to an apoptotic cascade of events. The main elements of this cascade are rapidly being elucidated. Flow cytometry has been used to follow many of these changes. It also has been used to quantify the number of apoptotic cells in a culture and, more recently, in clinical samples. In this review, the properties of apoptotic cells and the main feature of apoptotic cascade will be described. How flow cytometry can be used to follow changes during the apoptotic cascade will be discussed

  19. Autophagic cell death: Loch Ness monster or endangered species?

    Science.gov (United States)

    Shen, Han-Ming; Codogno, Patrice

    2011-05-01

    The concept of autophagic cell death was first established based on observations of increased autophagic markers in dying cells. The major limitation of such a morphology-based definition of autophagic cell death is that it fails to establish the functional role of autophagy in the cell death process, and thus contributes to the confusion in the literature regarding the role of autophagy in cell death and cell survival. Here we propose to define autophagic cell death as a modality of non-apoptotic or necrotic programmed cell death in which autophagy serves as a cell death mechanism, upon meeting the following set of criteria: (i) cell death occurs without the involvement of apoptosis; (ii) there is an increase of autophagic flux, and not just an increase of the autophagic markers, in the dying cells; and (iii) suppression of autophagy via both pharmacological inhibitors and genetic approaches is able to rescue or prevent cell death. In light of this new definition, we will discuss some of the common problems and difficulties in the study of autophagic cell death and also revisit some well-reported cases of autophagic cell death, aiming to achieve a better understanding of whether autophagy is a real killer, an accomplice or just an innocent bystander in the course of cell death. At present, the physiological relevance of autophagic cell death is mainly observed in lower eukaryotes and invertebrates such as Dictyostelium discoideum and Drosophila melanogaster. We believe that such a clear definition of autophagic cell death will help us study and understand the physiological or pathological relevance of autophagic cell death in mammals.

  20. Curcumin induces autophagic cell death in Spodoptera frugiperda cells.

    Science.gov (United States)

    Veeran, Sethuraman; Shu, Benshui; Cui, Gaofeng; Fu, Shengjiao; Zhong, Guohua

    2017-06-01

    The increasing interest in the role of autophagy (type II cell death) in the regulation of insect toxicology has propelled study of investigating autophagic cell death pathways. Turmeric, the rhizome of the herb Curcuma longa (Mañjaḷ in Tamil, India and Jiānghuáng in Chinese) have been traditionally used for the pest control either alone or combination with other botanical pesticides. However, the mechanisms by which Curcuma longa or curcumin exerts cytotoxicity in pests are not well understood. In this study, we investigated the potency of Curcuma longa (curcumin) as a natural pesticide employing Sf9 insect line. Autophagy induction effect of curcumin on Spodoptera frugiperda (Sf9) cells was investigated using various techniques including cell proliferation assay, morphology analysis with inverted phase contrast microscope and Transmission Electron Microscope (TEM) analysis. Autophagy was evaluated using the fluorescent dye monodansylcadaverine (MDC). Cell death measurement was examined using 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) within the concentrations of 5-15μg/mL. Curcumin inhibited the growth of the Sf9 cells and induced autophagic cell death in a time and dose dependent manner. Staining the cells with MDC showed the presence of autophagic vacuoles while increased in a dose and time dependent manner. At the ultrastructural level transmission electron microscopy, cells revealed massive autophagy vacuole accumulation and absence of chromatin condensation. Protein expression levels of ATG8-I and ATG8-II, well-established markers of autophagy related protein were elevated in a time dependent manner after curcumin treatment. The present study proves that curcumin induces autophagic cell death in Sf9 insect cell line and this is the first report of cytotoxic effect of curcumin in insect cells and that will be utilized as natural pesticides in future. Copyright © 2017. Published by Elsevier Inc.

  1. The importance of superficial basal cell carcinoma in a retrospective study of 139 patients who underwent Mohs micrographic surgery in a Brazilian university hospital

    Directory of Open Access Journals (Sweden)

    Luciana Takata Pontes

    2015-11-01

    Full Text Available OBJECTIVE: Mohs micrographic surgery is a specialized surgical procedure used to treat skin cancer. The purpose of this study was to better understand the profile of the patients who underwent the procedure and to determine how histology might be related to complications and the number of stages required for complete removal. METHODS: The records of patients who underwent Mohs micrographic surgery from October 2008 to November 2013 at the Dermatology Division of the Hospital of the Campinas University were assessed. The variables included were gender, age, anatomical location, histology, number of stages required and complications. RESULTS: Contingency tables were used to compare the number of stages with the histological diagnosis. The analysis showed that patients with superficial basal cell carcinoma were 9.03 times more likely to require more than one stage. A comparison between complications and histological diagnosis showed that patients with superficial basal cell carcinoma were 6.5 times more likely to experience complications. CONCLUSION: Although superficial basal cell carcinoma is typically thought to represent a less-aggressive variant of these tumors, its propensity for demonstrating “skip areas” and clinically indistinct borders make it a challenge to treat. Its particular nature may result in the higher number of surgery stages required, which may, as a consequence, result in more complications, including recurrence. Recurrence likely occurs due to the inadequate excision of the tumors despite their clear margins. Further research on this subtype of basal cell carcinoma is needed to optimize treatments and decrease morbidity.

  2. Mitochondrial fission proteins regulate programmed cell death in yeast.

    Science.gov (United States)

    Fannjiang, Yihru; Cheng, Wen-Chih; Lee, Sarah J; Qi, Bing; Pevsner, Jonathan; McCaffery, J Michael; Hill, R Blake; Basañez, Gorka; Hardwick, J Marie

    2004-11-15

    The possibility that single-cell organisms undergo programmed cell death has been questioned in part because they lack several key components of the mammalian cell death machinery. However, yeast encode a homolog of human Drp1, a mitochondrial fission protein that was shown previously to promote mammalian cell death and the excessive mitochondrial fragmentation characteristic of apoptotic mammalian cells. In support of a primordial origin of programmed cell death involving mitochondria, we found that the Saccharomyces cerevisiae homolog of human Drp1, Dnm1, promotes mitochondrial fragmentation/degradation and cell death following treatment with several death stimuli. Two Dnm1-interacting factors also regulate yeast cell death. The WD40 repeat protein Mdv1/Net2 promotes cell death, consistent with its role in mitochondrial fission. In contrast to its fission function in healthy cells, Fis1 unexpectedly inhibits Dnm1-mediated mitochondrial fission and cysteine protease-dependent cell death in yeast. Furthermore, the ability of yeast Fis1 to inhibit mitochondrial fission and cell death can be functionally replaced by human Bcl-2 and Bcl-xL. Together, these findings indicate that yeast and mammalian cells have a conserved programmed death pathway regulated by a common molecular component, Drp1/Dnm1, that is inhibited by a Bcl-2-like function.

  3. Early death, late death and repair factor in three human tumour cell lines

    International Nuclear Information System (INIS)

    Courdi, A.; Gioanni, J.; Mari, D.; Chauvel, P.

    1997-01-01

    The in vivo colony method used to generate survival curves following exposure to ionizing irradiation allows to score large clones, representing surviving cells, and small colonies, representing late reproductive death. By subtraction, early-dying cells can be estimated. In the three human tumour cell lines examined, we have observed that early cell death is a major mode of action of irradiation. The contribution of early cell death to total mortality increases as the dose increases. Moreover, repair due to dose-splitting and delayed plating in densely-inhibited cells is not observed in early-dying cells. (authors)

  4. Functional Changes of Dendritic Cells in C6 Glioma-Bearing Rats That Underwent Combined Argon-Helium Cryotherapy and IL-12 Treatment.

    Science.gov (United States)

    Li, Ming; Cui, Yao; Li, Xiqing; Guo, Yanwu; Wang, Bin; Zhang, Jiadong; Xu, Jian; Han, Shuangyin; Shi, Xiwen

    2016-08-01

    The aim of this study was to explore changes in tumor tissues of glioma-bearing rats that underwent argon-helium cryoablation as well as changes in antitumor immunity before and after combined interleukin 12 treatment. Two hundred sixty Wistar rats were randomly divided into a blank control group, intravenous injection interleukin-12 group, cryotherapy group, and cryotherapy + intravenous injection group. C6 glioma cells proliferated in vitro were implanted subcutaneously on the backs of rats to establish C6 glioma-bearing animal models. Each group underwent the corresponding treatments, and morphological changes in tumor tissues were examined using hematoxylin-eosin staining. CD11c staining was examined using immunohistochemistry, and differences in dendritic cells and T-cell subsets before and after treatment were analyzed using flow cytometry. The control group showed no statistical changes in terms of tumor tissue morphology and cellular immunity, cryotherapy group, and cryotherapy + intravenous injection group, among which the count for the cryotherapy + intravenous injection group was significantly higher than those of all other groups. In the argon-helium cryotherapy group, tumor cells were damaged and dendritic cell markers were positive. The number of CD11c+ and CD86+ cells increased significantly after the operation as did the cytokine interferon-γ level (P < .01), suggesting a shift toward Th1-type immunity. Combined treatment of argon-helium cryoablation and interleukin 12 for gliomas not only effectively injured tumor tissues but also boosted immune function and increased antitumor ability. Therefore, this approach is a promising treatment measure for brain gliomas. © The Author(s) 2015.

  5. Patterns and Timing of Failure for Diffuse Large B-Cell Lymphoma After Initial Therapy in a Cohort Who Underwent Autologous Bone Marrow Transplantation for Relapse

    Energy Technology Data Exchange (ETDEWEB)

    Dhakal, Sughosh; Bates, James E. [Department of Radiation Oncology, Wilmot Cancer Institute, University of Rochester Medical Center, Rochester, New York (United States); Casulo, Carla; Friedberg, Jonathan W.; Becker, Michael W.; Liesveld, Jane L. [Department of Medicine, Wilmot Cancer Institute, University of Rochester Medical Center, Rochester, New York (United States); Constine, Louis S., E-mail: louis_constine@urmc.rochester.edu [Department of Radiation Oncology, Wilmot Cancer Institute, University of Rochester Medical Center, Rochester, New York (United States)

    2016-10-01

    Purpose: To evaluate the location and timing of initial recurrence in patients with diffuse large B-cell lymphoma (DLBCL) who subsequently underwent high-dose chemotherapy with autologous stem cell transplant (HDC/ASCT), to direct approaches for disease surveillance, elucidate the patterns of failure of contemporary treatment strategies, and guide adjuvant treatment decisions. Methods and Materials: We analyzed consecutive patients with DLBCL who underwent HDC/ASCT between May 1992 and March 2014 at our institution. Of the 187 evaluable patients, 8 had incomplete data, and 79 underwent HDC/ASCT as a component of initial treatment for de novo or refractory DLBCL and were excluded from further analysis. Results: The median age was 50.8 years; the median time to relapse was 1.3 years. Patients were segregated according to the initial stage at diagnosis, with early stage (ES) defined as stage I/II and advanced stage (AS) defined as stage III/IV. In total, 40.4% of the ES and 75.5% of the AS patients relapsed in sites of initial disease; 68.4% of those with ES disease and 75.0% of those with AS disease relapsed in sites of initial disease only. Extranodal relapses were common (44.7% in ES and 35.9% in AS) and occurred in a variety of organs, although gastrointestinal tract/liver (n=12) was most frequent. Conclusions: Most patients with DLBCL who relapse and subsequently undergo HDC/ASCT initially recur in the previously involved disease site(s). Time to recurrence is brief, suggesting that frequency of screening is most justifiably greatest in the early posttherapy years. © 2016 Elsevier Inc.

  6. Plant programmed cell death, ethylene and flower senescence

    NARCIS (Netherlands)

    Woltering, E.J.; Jong, de A.; Hoeberichts, F.A.; Iakimova, E.T.; Kapchina, V.

    2005-01-01

    Programmed cell death (PCD) applies to cell death that is part of the normal life of multicellular organisms. PCD is found throughout the animal and plant kingdoms; it is an active process in which a cell suicide pathway is activated resulting in controlled disassembly of the cell. Most cases of PCD

  7. Can deaths in police cells be prevented? Experience from Norway and death rates in other countries.

    Science.gov (United States)

    Aasebø, Willy; Orskaug, Gunnar; Erikssen, Jan

    2016-01-01

    To describe the changes in death rates and causes of deaths in Norwegian police cells during the last 2 decades. To review reports on death rates in police cells that have been published in medical journals and elsewhere, and discuss the difficulties of comparing death rates between countries. Data on deaths in Norwegian police cells were collected retrospectively in 2002 and 2012 for two time periods: 1993-2001 (period 1) and 2003-2012 (period 2). Several databases were searched to find reports on deaths in police cells from as many countries as possible. The death rates in Norwegian police cells reduced significantly from 0.83 deaths per year per million inhabitants (DYM) in period 1 to 0.22 DYM in period 2 (p police cells reduced by about 75% over a period of approximately 10 years. This is probably mainly due to individuals with severe alcohol intoxication no longer being placed in police cells. However, there remain large methodology difficulties in comparing deaths rates between countries. Copyright © 2015 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

  8. The anti-cell death FNK protein protects cells from death induced by freezing and thawing

    International Nuclear Information System (INIS)

    Sudo, Kentaro; Asoh, Sadamitsu; Ohsawa, Ikuroh; Ozaki, Daiya; Yamagata, Kumi; Ito, Hiromoto; Ohta, Shigeo

    2005-01-01

    The FNK protein, constructed from anti-apoptotic Bcl-x L with enhanced activity, was fused with the protein transduction domain (PTD) of the HIV/Tat protein to mediate the delivery of FNK into cells. The fusion protein PTD-FNK was introduced into chondrocytes in isolated articular cartilage-bone sections, cultured neurons, and isolated bone marrow mononuclear cells to evaluate its ability to prevent cell death induced by freezing and thawing. PTD-FNK protected the cells from freeze-thaw damage in a concentration-dependent manner. Addition of PTD-FNK with conventional cryoprotectants (dimethyl sulfoxide and hydroxyethyl starch) increased surviving cell numbers around 2-fold compared with controls treated only with the cryoprotectants. Notably, PTD-FNK allowed CD34 + cells among bone marrow mononuclear cells to survive more efficiently (12-fold more than the control cells) from two successive freeze-thaw cycles. Thus, PTD-FNK prevented cell death induced by freezing and thawing, suggesting that it provides for the successful cryopreservation of biological materials

  9. Analysis of cell death inducing compounds

    DEFF Research Database (Denmark)

    Spicker, Jeppe; Pedersen, Henrik Toft; Nielsen, Henrik Bjørn

    2007-01-01

    Biomarkers for early detection of toxicity hold the promise of improving the failure rates in drug development. In the present study, gene expression levels were measured using full-genome RAE230 version 2 Affymetrix GeneChips on rat liver tissue 48 h after administration of six different compounds......), ornithine aminotransferase (OAT) and Cytochrome P450, subfamily IIC (mephenytoin 4-hydroxylase) (Cyp2C29). RT-PCR for these three genes was performed and four additional compounds were included for validation. The quantitative RT-PCR analysis confirmed the findings based on the microarray data and using...... the three genes a classification rate of 55 of 57 samples was achieved for the classification of not toxic versus toxic. The single most promising biomarker (OAT) alone resulted in a surprisingly 100% correctly classified samples. OAT has not previously been linked to toxicity and cell death...

  10. Methods for assessing autophagy and autophagic cell death.

    Science.gov (United States)

    Tasdemir, Ezgi; Galluzzi, Lorenzo; Maiuri, M Chiara; Criollo, Alfredo; Vitale, Ilio; Hangen, Emilie; Modjtahedi, Nazanine; Kroemer, Guido

    2008-01-01

    Autophagic (or type 2) cell death is characterized by the massive accumulation of autophagic vacuoles (autophagosomes) in the cytoplasm of cells that lack signs of apoptosis (type 1 cell death). Here we detail and critically assess a series of methods to promote and inhibit autophagy via pharmacological and genetic manipulations. We also review the techniques currently available to detect autophagy, including transmission electron microscopy, half-life assessments of long-lived proteins, detection of LC3 maturation/aggregation, fluorescence microscopy, and colocalization of mitochondrion- or endoplasmic reticulum-specific markers with lysosomal proteins. Massive autophagic vacuolization may cause cellular stress and represent a frustrated attempt of adaptation. In this case, cell death occurs with (or in spite of) autophagy. When cell death occurs through autophagy, on the contrary, the inhibition of the autophagic process should prevent cellular demise. Accordingly, we describe a strategy for discriminating cell death with autophagy from cell death through autophagy.

  11. HO-1 gene overexpression enhances the beneficial effects of superparamagnetic iron oxide labeled bone marrow stromal cells transplantation in swine hearts underwent ischemia/reperfusion: an MRI study.

    Science.gov (United States)

    Jiang, Yibo; Chen, Lijuan; Tang, Yaoliang; Ma, Genshan; Shen, Chengxing; Qi, Chunmei; Zhu, Qi; Yao, Yuyu; Liu, Naifeng

    2010-05-01

    To determine the effect of intracoronary transfer of superparamagnetic iron oxide (SPIO) labeled heme oxygenase-1 (HO-1) overexpressed bone marrow stromal cells (BMSCs) in a porcine myocardial ischemia/reperfusion model. Cell apoptosis was assayed and supernatant cytokine concentrations were measured in BMSCs that underwent hypoxia/reoxygen in vitro. Female mini-swines that underwent 1 h LAD occlusion followed by 1 h reperfusion were randomly allocated to receive intracoronary saline (control), 1 x 10(7) SPIO-labeled BMSCs transfected with pcDNA3.1-Lacz plasmid (Lacz-BMSCs), pcDNA3.1-human HO-1 (HO-1-BMSCs), pcDNA3.1-hHO-1 pretreated with a HO inhibitor, tin protoporphyrin (SnPP, n = 10 each). MRI and postmortem histological analysis were made at 1 week or 3 months thereafter. Post hypoxia/reoxygen in vitro, apoptosis was significantly reduced, supernatant VEGF significantly increased while TNF-alpha and IL-6 significantly reduced in HO-1-BMSCs group compared with Lacz-BMSCs group (all p < 0.05). Myocardial expression of VEGF was significantly higher in HO-1-BMSCs than in Lacz-BMSCs group at 1 week post transplantation (all p < 0.05). Signal voids induced by the SPIO were detected in the peri-infarction region in all BMSC groups at 1 week but not at 3 months post transplantation and the extent of the hypointense signal was the highest in HO-1-BMSCs group, and histological analysis showed that signal voids represented cardiac macrophages that engulfed the SPIO-labeled BMSCs. Pretreatment with SnPP significantly attenuated the beneficial effects of HO-1-BMSCs. Transplantation of HO-1-overexpressed BMSCs significantly enhanced the beneficial effects of BMSCs on improving cardiac function in this model.

  12. Mechanisms of Betulinic acid‐induced cell death

    NARCIS (Netherlands)

    Potze, L.

    2015-01-01

    The scope of this thesis was to investigate the mechanisms by which BetA induces cell death in cancer cells in more detail. At the start of the studies described in this thesis several questions urgently needed an answer. Although BetA induces cell death via apoptosis, when blocking this form of

  13. Programmed cell death and cell extrusion in rat duodenum

    DEFF Research Database (Denmark)

    Schauser, Kirsten; Larsson, Lars-Inge

    2005-01-01

    The small intestinal epithelium is continously renewed through a balance between cell division and cell loss. How this balance is achieved is uncertain. Thus, it is unknown to what extent programmed cell death (PCD) contributes to intestinal epithelial cell loss. We have used a battery...... of techniques detecting the events associated with PCD in order to better understand its role in the turnover of the intestinal epithelium, including modified double- and triple-staining techniques for simultaneously detecting multiple markers of PCD in individual cells. Only a partial correlation between TUNEL...... positivity for DNA fragmentation, c-jun phosphorylation on serine-63, positivity for activated caspase-3 and apoptotic morphology was observed. Our results show that DNA fragmentation does not invariable correlate to activation of caspase-3. Moreover, many cells were found to activate caspase-3 early...

  14. Transglutaminase induction by various cell death and apoptosis pathways.

    Science.gov (United States)

    Fesus, L; Madi, A; Balajthy, Z; Nemes, Z; Szondy, Z

    1996-10-31

    Clarification of the molecular details of forms of natural cell death, including apoptosis, has become one of the most challenging issues of contemporary biomedical sciences. One of the effector elements of various cell death pathways is the covalent cross-linking of cellular proteins by transglutaminases. This review will discuss the accumulating data related to the induction and regulation of these enzymes, particularly of tissue type transglutaminase, in the molecular program of cell death. A wide range of signalling pathways can lead to the parallel induction of apoptosis and transglutaminase, providing a handle for better understanding the exact molecular interactions responsible for the mechanism of regulated cell death.

  15. Programmed cell death for defense against anomaly and tumor formation

    International Nuclear Information System (INIS)

    Kondo, Sohei; Norimura, Toshiyuki; Nomura, Taisei

    1995-01-01

    Cell death after exposure to low-level radiation is often considered evidence that radiation is poisonous, however small the dose. Evidence has been accumulating to support the notion that cell death after low-level exposure to radiation results from activation of suicidal genes open-quote programmed cell death close-quote or open-quote apoptosis close-quote - for the health of the whole body. This paper gives experimental evidence that embryos of fruit flies and mouse fetuses have potent defense mechanisms against teratogenic or tumorigenic injury caused by radiation and carcinogens, which function through programmed cell death

  16. The slow cell death response when screening chemotherapeutic agents.

    Science.gov (United States)

    Blois, Joseph; Smith, Adam; Josephson, Lee

    2011-09-01

    To examine the correlation between cell death and a common surrogate of death used in screening assays, we compared cell death responses to those obtained with the sulforhodamine B (SRB) cell protein-based "cytotoxicity" assay. With the SRB assay, the Hill equation was used to obtain an IC50 and final cell mass, or cell mass present at infinite agent concentrations, with eight adherent cell lines and four agents (32 agent/cell combinations). Cells were treated with high agent concentrations (well above the SRB IC50) and the death response determined as the time-dependent decrease in cells failing to bind both annexin V and vital fluorochromes by flow cytometry. Death kinetics were categorized as fast (5/32) (similar to the reference nonadherent Jurkat line), slow (17/32), or none (10/32), despite positive responses in the SRB assay in all cases. With slow cell death, a single exposure to a chemotherapeutic agent caused a slow, progressive increase in dead (necrotic) and dying (apoptotic) cells for at least 72 h. Cell death (defined by annexin and/or fluorochrome binding) did not correlate with the standard SRB "cytotoxicity" assay. With the slow cell death response, a single exposure to an agent caused a slow conversion from vital to apoptotic and necrotic cells over at least 72 h (the longest time point examined). Here, increasing the time of exposure to agent concentrations modestly above the SRB IC50 provides a method of maximizing cell kill. If tumors respond similarly, sustained low doses of chemotherapeutic agents, rather than a log-kill, maximum tolerated dose strategy may be an optimal strategy of maximizing tumor cell death.

  17. BID links ferroptosis to mitochondrial cell death pathways

    Directory of Open Access Journals (Sweden)

    Sandra Neitemeier

    2017-08-01

    Full Text Available Ferroptosis has been defined as an oxidative and iron-dependent pathway of regulated cell death that is distinct from caspase-dependent apoptosis and established pathways of death receptor-mediated regulated necrosis. While emerging evidence linked features of ferroptosis induced e.g. by erastin-mediated inhibition of the Xc- system or inhibition of glutathione peroxidase 4 (Gpx4 to an increasing number of oxidative cell death paradigms in cancer cells, neurons or kidney cells, the biochemical pathways of oxidative cell death remained largely unclear. In particular, the role of mitochondrial damage in paradigms of ferroptosis needs further investigation.In the present study, we find that erastin-induced ferroptosis in neuronal cells was accompanied by BID transactivation to mitochondria, loss of mitochondrial membrane potential, enhanced mitochondrial fragmentation and reduced ATP levels. These hallmarks of mitochondrial demise are also established features of oxytosis, a paradigm of cell death induced by Xc- inhibition by millimolar concentrations of glutamate. Bid knockout using CRISPR/Cas9 approaches preserved mitochondrial integrity and function, and mediated neuroprotective effects against both, ferroptosis and oxytosis. Furthermore, the BID-inhibitor BI-6c9 inhibited erastin-induced ferroptosis, and, in turn, the ferroptosis inhibitors ferrostatin-1 and liproxstatin-1 prevented mitochondrial dysfunction and cell death in the paradigm of oxytosis. These findings show that mitochondrial transactivation of BID links ferroptosis to mitochondrial damage as the final execution step in this paradigm of oxidative cell death. Keywords: Ferroptosis, BID, Mitochondria, CRISPR, Oxytosis, Neuronal death

  18. Mitochondrial apoptotic pathways induced by Drosophila programmed cell death regulators

    International Nuclear Information System (INIS)

    Claveria, Cristina; Torres, Miguel

    2003-01-01

    Multicellular organisms eliminate unwanted or damaged cells by cell death, a process essential to the maintenance of tissue homeostasis. Cell death is a tightly regulated event, whose alteration by excess or defect is involved in the pathogenesis of many diseases such as cancer, autoimmune syndromes, and neurodegenerative processes. Studies in model organisms, especially in the nematode Caenorhabditis elegans, have been crucial in identifying the key molecules implicated in the regulation and execution of programmed cell death. In contrast, the study of cell death in Drosophila melanogaster, often an excellent model organism, has identified regulators and mechanisms not obviously conserved in other metazoans. Recent molecular and cellular analyses suggest, however, that the mechanisms of action of the main programmed cell death regulators in Drosophila include a canonical mitochondrial pathway

  19. Mechanisms of Virus-Induced Neural Cell Death

    National Research Council Canada - National Science Library

    Tyler, Kenneth

    2002-01-01

    Virtually all known neurotropic viruses are capable of killing infected cells by inducing a specific pattern of cell death known as apoptosis, yet the mechanism by which this occurs and its relevance...

  20. Delayed cell death associated with mitotic catastrophe in γ-irradiated stem-like glioma cells

    International Nuclear Information System (INIS)

    Firat, Elke; Gaedicke, Simone; Tsurumi, Chizuko; Esser, Norbert; Weyerbrock, Astrid; Niedermann, Gabriele

    2011-01-01

    Stem-like tumor cells are regarded as highly resistant to ionizing radiation (IR). Previous studies have focused on apoptosis early after irradiation, and the apoptosis resistance observed has been attributed to reduced DNA damage or enhanced DNA repair compared to non-stem tumor cells. Here, early and late radioresponse of patient-derived stem-like glioma cells (SLGCs) and differentiated cells directly derived from them were examined for cell death mode and the influence of stem cell-specific growth factors. Primary SLGCs were propagated in serum-free medium with the stem-cell mitogens epidermal growth factor (EGF) and fibroblast growth factor-2 (FGF-2). Differentiation was induced by serum-containing medium without EGF and FGF. Radiation sensitivity was evaluated by assessing proliferation, clonogenic survival, apoptosis, and mitotic catastrophe. DNA damage-associated γH2AX as well as p53 and p21 expression were determined by Western blots. SLGCs failed to apoptose in the first 4 days after irradiation even at high single doses up to 10 Gy, but we observed substantial cell death later than 4 days postirradiation in 3 of 6 SLGC lines treated with 5 or 10 Gy. This delayed cell death was observed in 3 of the 4 SLGC lines with nonfunctional p53, was associated with mitotic catastrophe and occurred via apoptosis. The early apoptosis resistance of the SLGCs was associated with lower γH2AX compared to differentiated cells, but we found that the stem-cell culture cytokines EGF plus FGF-2 strongly reduce γH2AX levels. Nonetheless, in two p53-deficient SLGC lines examined γIR-induced apoptosis even correlated with EGF/FGF-induced proliferation and mitotic catastrophe. In a line containing CD133-positive and -negative stem-like cells, the CD133-positive cells proliferated faster and underwent more γIR-induced mitotic catastrophe. Our results suggest the importance of delayed apoptosis, associated mitotic catastrophe, and cellular proliferation for γIR-induced death of

  1. The convergence of radiation and immunogenic cell death signaling pathways

    International Nuclear Information System (INIS)

    Golden, Encouse B.; Pellicciotta, Ilenia; Demaria, Sandra; Barcellos-Hoff, Mary H.; Formenti, Silvia C.

    2012-01-01

    Ionizing radiation (IR) triggers programmed cell death in tumor cells through a variety of highly regulated processes. Radiation-induced tumor cell death has been studied extensively in vitro and is widely attributed to multiple distinct mechanisms, including apoptosis, necrosis, mitotic catastrophe (MC), autophagy, and senescence, which may occur concurrently. When considering tumor cell death in the context of an organism, an emerging body of evidence suggests there is a reciprocal relationship in which radiation stimulates the immune system, which in turn contributes to tumor cell kill. As a result, traditional measurements of radiation-induced tumor cell death, in vitro, fail to represent the extent of clinically observed responses, including reductions in loco-regional failure rates and improvements in metastases free and overall survival. Hence, understanding the immunological responses to the type of radiation-induced cell death is critical. In this review, the mechanisms of radiation-induced tumor cell death are described, with particular focus on immunogenic cell death (ICD). Strategies combining radiotherapy with specific chemotherapies or immunotherapies capable of inducing a repertoire of cancer specific immunogens might potentiate tumor control not only by enhancing cell kill but also through the induction of a successful anti-tumor vaccination that improves patient survival.

  2. Non-Canonical Cell Death Induced by p53

    Directory of Open Access Journals (Sweden)

    Atul Ranjan

    2016-12-01

    Full Text Available Programmed cell death is a vital biological process for multicellular organisms to maintain cellular homeostasis, which is regulated in a complex manner. Over the past several years, apart from apoptosis, which is the principal mechanism of caspase-dependent cell death, research on non-apoptotic forms of programmed cell death has gained momentum. p53 is a well characterized tumor suppressor that controls cell proliferation and apoptosis and has also been linked to non-apoptotic, non-canonical cell death mechanisms. p53 impacts these non-canonical forms of cell death through transcriptional regulation of its downstream targets, as well as direct interactions with key players involved in these mechanisms, in a cell type- or tissue context-dependent manner. In this review article, we summarize and discuss the involvement of p53 in several non-canonical modes of cell death, including caspase-independent apoptosis (CIA, ferroptosis, necroptosis, autophagic cell death, mitotic catastrophe, paraptosis, and pyroptosis, as well as its role in efferocytosis which is the process of clearing dead or dying cells.

  3. Sorafenib-induced defective autophagy promotes cell death by necroptosis

    OpenAIRE

    Kharaziha, Pedram; Chioureas, Dimitris; Baltatzis, George; Fonseca, Pedro; Rodriguez, Patricia; Gogvadze, Vladimir; Lennartsson, Lena; Bj?rklund, Ann-Charlotte; Zhivotovsky, Boris; Grand?r, Dan; Egevad, Lars; Nilsson, Sten; Panaretakis, Theocharis

    2015-01-01

    Autophagy is one of the main cytoprotective mechanisms that cancer cells deploy to withstand the cytotoxic stress and survive the lethal damage induced by anti-cancer drugs. However, under specific conditions, autophagy may, directly or indirectly, induce cell death. In our study, treatment of the Atg5-deficient DU145 prostate cancer cells, with the multi-tyrosine kinase inhibitor, sorafenib, induces mitochondrial damage, autophagy and cell death. Molecular inhibition of autophagy by silencin...

  4. Sorafenib-induced defective autophagy promotes cell death by necroptosis.

    Science.gov (United States)

    Kharaziha, Pedram; Chioureas, Dimitris; Baltatzis, George; Fonseca, Pedro; Rodriguez, Patricia; Gogvadze, Vladimir; Lennartsson, Lena; Björklund, Ann-Charlotte; Zhivotovsky, Boris; Grandér, Dan; Egevad, Lars; Nilsson, Sten; Panaretakis, Theocharis

    2015-11-10

    Autophagy is one of the main cytoprotective mechanisms that cancer cells deploy to withstand the cytotoxic stress and survive the lethal damage induced by anti-cancer drugs. However, under specific conditions, autophagy may, directly or indirectly, induce cell death. In our study, treatment of the Atg5-deficient DU145 prostate cancer cells, with the multi-tyrosine kinase inhibitor, sorafenib, induces mitochondrial damage, autophagy and cell death. Molecular inhibition of autophagy by silencing ULK1 and Beclin1 rescues DU145 cells from cell death indicating that, in this setting, autophagy promotes cell death. Re-expression of Atg5 restores the lipidation of LC3 and rescues DU145 and MEF atg5-/- cells from sorafenib-induced cell death. Despite the lack of Atg5 expression and LC3 lipidation, DU145 cells form autophagosomes as demonstrated by transmission and immuno-electron microscopy, and the formation of LC3 positive foci. However, the lack of cellular content in the autophagosomes, the accumulation of long-lived proteins, the presence of GFP-RFP-LC3 positive foci and the accumulated p62 protein levels indicate that these autophagosomes may not be fully functional. DU145 cells treated with sorafenib undergo a caspase-independent cell death that is inhibited by the RIPK1 inhibitor, necrostatin-1. Furthermore, treatment with sorafenib induces the interaction of RIPK1 with p62, as demonstrated by immunoprecipitation and a proximity ligation assay. Silencing of p62 decreases the RIPK1 protein levels and renders necrostatin-1 ineffective in blocking sorafenib-induced cell death. In summary, the formation of Atg5-deficient autophagosomes in response to sorafenib promotes the interaction of p62 with RIPK leading to cell death by necroptosis.

  5. Stem cell death and survival in heart regeneration and repair.

    Science.gov (United States)

    Abdelwahid, Eltyeb; Kalvelyte, Audrone; Stulpinas, Aurimas; de Carvalho, Katherine Athayde Teixeira; Guarita-Souza, Luiz Cesar; Foldes, Gabor

    2016-03-01

    Cardiovascular diseases are major causes of mortality and morbidity. Cardiomyocyte apoptosis disrupts cardiac function and leads to cardiac decompensation and terminal heart failure. Delineating the regulatory signaling pathways that orchestrate cell survival in the heart has significant therapeutic implications. Cardiac tissue has limited capacity to regenerate and repair. Stem cell therapy is a successful approach for repairing and regenerating ischemic cardiac tissue; however, transplanted cells display very high death percentage, a problem that affects success of tissue regeneration. Stem cells display multipotency or pluripotency and undergo self-renewal, however these events are negatively influenced by upregulation of cell death machinery that induces the significant decrease in survival and differentiation signals upon cardiovascular injury. While efforts to identify cell types and molecular pathways that promote cardiac tissue regeneration have been productive, studies that focus on blocking the extensive cell death after transplantation are limited. The control of cell death includes multiple networks rather than one crucial pathway, which underlies the challenge of identifying the interaction between various cellular and biochemical components. This review is aimed at exploiting the molecular mechanisms by which stem cells resist death signals to develop into mature and healthy cardiac cells. Specifically, we focus on a number of factors that control death and survival of stem cells upon transplantation and ultimately affect cardiac regeneration. We also discuss potential survival enhancing strategies and how they could be meaningful in the design of targeted therapies that improve cardiac function.

  6. Significance of apoptotic cell death after γ-irradiation

    International Nuclear Information System (INIS)

    Wu, H.G.; Kim, I.H.; Ha, S.W.; Park, C.I.

    2003-01-01

    Full text: The objectives of this study are to investigate the significance of apoptotic death compared to total cell death after γ-ray irradiation in human Hand N cancer cell lines and to find out correlation between apoptosis and radiation sensitivity. Materials and Method: Head and neck cancer cell lines (PCI-1, PCI-13, and SNU-1066), leukemia cell line (CCRF-CEM), and fibroblast cell line (LM217) as a normal control were used for this study. Cells were irradiated using Cs-137 animal experiment irradiator. Total cell death was measured by clonogenic assay. Annexin-V staining was used to detect the fraction of apoptotic death. The resulting data was analyzed with two parameters, apoptotic index (AI) and apoptotic fraction(AF). AI is ratio of apoptotic cells to total cells, and AF is ration of apoptotic cell death to mutant frequencytion ex(Number of apoptotic cells) / (Number of total cells counted) AF = {(AI) / (1-survival fraction)} x 100 (%) Results. Surviving fraction at 2 Gy (SF2) were 0.741, 0.544, 0.313, 0.302, and 0.100 for PCI-1, PCI-13, SNU-1066, CCRF-CEM, and LM217 cell lines, respectively. Apoptosis was detected in all cell lines. Apoptotic index reached peak value at 72 hours after irradiation in head and neck cancer cell lines, and that was at 24 hours in CCRF-CEM and LM217. Total cell death increased exponentially with increasing radiation dose from 0 Gy to 8 Gy, but the change was minimal in apoptotic index (Fig. 1.). Apoptotic fractions at 2 Gy were 46%, 48%, 46%, 24%, and 19% and at 6 Gy were 20%, 33%, 35%, 17%, and 20% for PCI-1, PCI-13, SNU-1066, CCRF-CEM, and LM217, respectively. The radioresistant cell lines showed more higher apoptotic fraction at 2 Gy (Table 1.), but there was not such correlation at 6 Gy. Conclusion: All cell lines used in this study showed apoptosis after irradiation, but time course of apoptosis was different from that of leukemia cell line and normal fibroblast cell line. Reproductive cell death was more important

  7. Programmed Cell Death and Postharvest Deterioration of Horticultural Produce

    NARCIS (Netherlands)

    Woltering, E.J.; Iakimova, E.T.

    2010-01-01

    Programmed cell death (PCD) is a process where cells or tissues are broken down in an orderly and predictable manner, whereby nutrients are re-used by other cells, tissues or plant parts. The process of (petal) senescence shows many similarities to autophagic PCD in animal cells including a massive

  8. Mechanical Stress Promotes Cisplatin-Induced Hepatocellular Carcinoma Cell Death

    Directory of Open Access Journals (Sweden)

    Laila Ziko

    2015-01-01

    Full Text Available Cisplatin (CisPt is a commonly used platinum-based chemotherapeutic agent. Its efficacy is limited due to drug resistance and multiple side effects, thereby warranting a new approach to improving the pharmacological effect of CisPt. A newly developed mathematical hypothesis suggested that mechanical loading, when coupled with a chemotherapeutic drug such as CisPt and immune cells, would boost tumor cell death. The current study investigated the aforementioned mathematical hypothesis by exposing human hepatocellular liver carcinoma (HepG2 cells to CisPt, peripheral blood mononuclear cells, and mechanical stress individually and in combination. HepG2 cells were also treated with a mixture of CisPt and carnosine with and without mechanical stress to examine one possible mechanism employed by mechanical stress to enhance CisPt effects. Carnosine is a dipeptide that reportedly sequesters platinum-based drugs away from their pharmacological target-site. Mechanical stress was achieved using an orbital shaker that produced 300 rpm with a horizontal circular motion. Our results demonstrated that mechanical stress promoted CisPt-induced death of HepG2 cells (~35% more cell death. Moreover, results showed that CisPt-induced death was compromised when CisPt was left to mix with carnosine 24 hours preceding treatment. Mechanical stress, however, ameliorated cell death (20% more cell death.

  9. Mechanical Stress Promotes Cisplatin-Induced Hepatocellular Carcinoma Cell Death

    Science.gov (United States)

    Riad, Sandra; Bougherara, Habiba

    2015-01-01

    Cisplatin (CisPt) is a commonly used platinum-based chemotherapeutic agent. Its efficacy is limited due to drug resistance and multiple side effects, thereby warranting a new approach to improving the pharmacological effect of CisPt. A newly developed mathematical hypothesis suggested that mechanical loading, when coupled with a chemotherapeutic drug such as CisPt and immune cells, would boost tumor cell death. The current study investigated the aforementioned mathematical hypothesis by exposing human hepatocellular liver carcinoma (HepG2) cells to CisPt, peripheral blood mononuclear cells, and mechanical stress individually and in combination. HepG2 cells were also treated with a mixture of CisPt and carnosine with and without mechanical stress to examine one possible mechanism employed by mechanical stress to enhance CisPt effects. Carnosine is a dipeptide that reportedly sequesters platinum-based drugs away from their pharmacological target-site. Mechanical stress was achieved using an orbital shaker that produced 300 rpm with a horizontal circular motion. Our results demonstrated that mechanical stress promoted CisPt-induced death of HepG2 cells (~35% more cell death). Moreover, results showed that CisPt-induced death was compromised when CisPt was left to mix with carnosine 24 hours preceding treatment. Mechanical stress, however, ameliorated cell death (20% more cell death). PMID:25685789

  10. Award nomination for study of cell death in radiation sickness

    Energy Technology Data Exchange (ETDEWEB)

    Ivanitskiy, G

    1985-01-01

    The author discusses the importance of the work entitled Formulation of Theoretical Bases of the Phenomenon of Cell Death and Their Use in Explaining the Pathogenesis of Radiation Sickness, which has been nominated for the 1985 USSR State Prize. The author notes that the study of the nature and mechanisms of cell death from ionizing radiation consumed the efforts of researchers of various specialties for more than 20 years. The author observes that study of the molecular basis of the high radiosensitivity of lymphocytes became the key to understanding the general biological phenomenon of cell death.

  11. Sickle cell trait and sudden death--bringing it home.

    Science.gov (United States)

    Mitchell, Bruce L.

    2007-01-01

    Sickle cell trait continues to be the leading cause of sudden death for young African Americans in military basic training and civilian organized sports. The syndrome may have caused the death of up to 10 college football players since 1974 and, as recently as 2000, was suspected as the cause of death of three U.S. Army recruits. The penal military-style boot camps in the United States and the recent death of two teenagers with sickle cell trait merits renewed vigor in the education of athletic instructors, the military and the public about conditions associated with sudden death in individuals with sickle cell trait. Images Figure 1 Figure 2 PMID:17393956

  12. Curcumin Attenuates Staurosporine-Mediated Death of Retinal Ganglion Cells

    OpenAIRE

    Burugula, Balabharathi; Ganesh, Bhagyalaxmi S.; Chintala, Shravan K.

    2011-01-01

    The functional effect of curcumin, a free radical scavenger and an herbal medicine from Indian yellow curry spice, Curcuma longa, on protease-mediated retinal ganglion cell death was investigated. These results show, for the first time, that curcumin indeed prevents the protease-mediated death of RGCs, both in vitro and in vivo.

  13. BID links ferroptosis to mitochondrial cell death pathways

    NARCIS (Netherlands)

    Neitemeier, Sandra; Jelinek, Anja; Laino, Vincenzo; Hoffmann, Lena; Eisenbach, Ina; Eying, Roman; Ganjam, Goutham K; Dolga, Amalia M; Oppermann, Sina; Culmsee, Carsten

    2017-01-01

    Ferroptosis has been defined as an oxidative and iron-dependent pathway of regulated cell death that is distinct from caspase-dependent apoptosis and established pathways of death receptor-mediated regulated necrosis. While emerging evidence linked features of ferroptosis induced e.g. by

  14. Modelling radiation-induced cell death and tumour re-oxygenation: local versus global and instant versus delayed cell death

    International Nuclear Information System (INIS)

    Gago-Arias, Araceli; Espinoza, Ignacio; Sánchez-Nieto, Beatriz; Aguiar, Pablo; Pardo-Montero, Juan

    2016-01-01

    The resistance of hypoxic cells to radiation, due to the oxygen dependence of radiosensitivity, is well known and must be taken into account to accurately calculate the radiation induced cell death. A proper modelling of the response of tumours to radiation requires deriving the distribution of oxygen at a microscopic scale. This usually involves solving the reaction-diffusion equation in tumour voxels using a vascularization distribution model. Moreover, re-oxygenation arises during the course of radiotherapy, one reason being the increase of available oxygen caused by cell killing, which can turn hypoxic tumours into oxic. In this work we study the effect of cell death kinetics in tumour oxygenation modelling, analysing how it affects the timing of re-oxygenation, surviving fraction and tumour control. Two models of cell death are compared, an instantaneous cell killing, mimicking early apoptosis, and a delayed cell death scenario in which cells can die shortly after being damaged, as well as long after irradiation. For each of these scenarios, the decrease in oxygen consumption due to cell death can be computed globally (macroscopic voxel average) or locally (microscopic). A re-oxygenation model already used in the literature, the so called full re-oxygenation, is also considered. The impact of cell death kinetics and re-oxygenation on tumour responses is illustrated for two radiotherapy fractionation schemes: a conventional schedule, and a hypofractionated treatment. The results show large differences in the doses needed to achieve 50% tumour control for the investigated cell death models. Moreover, the models affect the tumour responses differently depending on the treatment schedule. This corroborates the complex nature of re-oxygenation, showing the need to take into account the kinetics of cell death in radiation response models. (paper)

  15. Calpain Determines the Propensity of Adult Hippocampal Neural Stem Cells to Autophagic Cell Death Following Insulin Withdrawal.

    Science.gov (United States)

    Chung, Kyung Min; Park, Hyunhee; Jung, Seonghee; Ha, Shinwon; Yoo, Seung-Jun; Woo, Hanwoong; Lee, Hyang Ju; Kim, Seong Who; Kim, Eun-Kyoung; Moon, Cheil; Yu, Seong-Woon

    2015-10-01

    Programmed cell death (PCD) has significant effects on the function of neural stem cells (NSCs) during brain development and degeneration. We have previously reported that adult rat hippocampal neural stem (HCN) cells underwent autophagic cell death (ACD) rather than apoptosis following insulin withdrawal despite their intact apoptotic capabilities. Here, we report a switch in the mode of cell death in HCN cells with calpain as a critical determinant. In HCN cells, calpain 1 expression was barely detectable while calpain 2 was predominant. Inhibition of calpain in insulin-deprived HCN cells further augmented ACD. In contrast, expression of calpain 1 switched ACD to apoptosis. The proteasome inhibitor lactacystin blocked calpain 2 degradation and elevated the intracellular Ca(2+) concentration. In combination, these effects potentiated calpain activity and converted the mode of cell death to apoptosis. Our results indicate that low calpain activity, due to absence of calpain 1 and degradation of calpain 2, results in a preference for ACD over apoptosis in insulin-deprived HCN cells. On the other hand, conditions leading to high calpain activity completely switch the mode of cell death to apoptosis. This is the first report on the PCD mode switching mechanism in NSCs. The dynamic change in calpain activity through the proteasome-mediated modulation of the calpain and intracellular Ca(2+) levels may be the critical contributor to the demise of NSCs. Our findings provide a novel insight into the complex mechanisms interconnecting autophagy and apoptosis and their roles in the regulation of NSC death. © 2015 AlphaMed Press.

  16. Checkpoint Inhibition: Programmed Cell Death 1 and Programmed Cell Death 1 Ligand Inhibitors in Hodgkin Lymphoma.

    Science.gov (United States)

    Villasboas, Jose Caetano; Ansell, Stephen

    2016-01-01

    Hodgkin lymphoma (HL) is a lymphoid malignancy characterized by a reactive immune infiltrate surrounding relatively few malignant cells. In this scenario, active immune evasion seems to play a central role in allowing tumor progression. Immune checkpoint inhibitor pathways are normal mechanisms of T-cell regulation that suppress immune effector function following an antigenic challenge. Hodgkin lymphoma cells are able to escape immune surveillance by co-opting these mechanisms. The programmed cell death 1 (PD-1) pathway in particular is exploited in HL as the malignant Hodgkin and Reed-Sternberg cells express on their surface cognate ligands (PD-L1/L2) for the PD-1 receptor and thereby dampen the T-cell-mediated antitumoral response. Monoclonal antibodies that interact with and disrupt the PD-1:PD-L1/L2 axis have now been developed and tested in early-phase clinical trials in patients with advanced HL with encouraging results. The remarkable clinical activity of PD-1 inhibitors in HL highlights the importance of immune checkpoint pathways as therapeutic targets in HL. In this review, we discuss the rationale for targeting PD-1 and PD-L1 in the treatment of HL. We will evaluate the published clinical data on the different agents and highlight the safety profile of this class of agents. We discuss the available evidence on the use of biomarkers as predictors of response to checkpoint blockade and summarize the areas under active investigation in the use of PD-1/PD-L1 inhibitors for the treatment of HL.

  17. The control and execution of programmed cell death

    International Nuclear Information System (INIS)

    Begum, R.; Pathak, N.; Hasnain, S.E.; Sah, N.K.; Athar, M.

    1999-01-01

    Apoptosis or programmed cell death is a highly conserved genetically controlled response of metazoan cells to commit suicide. Non apoptotic programmed cell death seems to operate in single celled eukaryotes implying that evolution of PCD has preceded the evolution of multicellularity. PCD plays a crucial role in the regulation of cellular and tissue homeostasis and any aberrations in apoptosis leads to several diseases including cancer, neurodegenerative disorders and AIDS. The mechanisms by which apoptosis is controlled are varied. In some cells, members of bcl-2 family or p53 are crucial for regulating the apoptosis programme, whereas in other cells Fas ligand is more important. bcl-2 family members have a prime role in the regulation of cell death at all stages including development, whereas cell death during development is independent of p53. bcl-2 family members being localized on the outer mitochondrial membrane, control the mitochondrial homeostasis and cytochrome c redistribution and thereby regulate the cell death process. p53 promotes DNA damage mediated cell death after growth arrest and failed DNA repair. Caspases play a key role in the execution of cell death by mediating highly specific cleavages of crucial cellular proteins collectively manifesting the apoptotic phenotype. Protein inhibitors like crm A, p35 and IAPs could prevent/control apoptosis induced by a broad array of cell death stimuli by several mechanisms specially interfering in caspase activation or caspase activity. Among endonucleases, caspase activated DNase (CAD) plays a crucial role in DNA fragmentation, a biochemical hallmark of apoptosis. As regulation of cell death seems to be as complex as regulation of cell proliferation, multiple kinase mediated regulatory mechanisms might control the apoptotic process. Thus, in spite of intensive research over the past few years, the field of apoptosis still remains fertile to unravel among others, the molecular mechanisms of cytochrome c

  18. The control and execution of programmed cell death

    Energy Technology Data Exchange (ETDEWEB)

    Begum, R.; Pathak, N.; Hasnain, S.E.; Sah, N.K. [National Inst. of Immunology, New Delhi (India). Eukaryotic Gene Expression Lab.; Taneja, T.K.; Mohan, M. [National Inst. of Immunology, New Delhi (India). Eukaryotic Gene Expression Lab.]|[Dept. of Medical Elementology and Toxicology, New Delhi (India); Athar, M. [Dept. of Medical Elementology and Toxicology, New Delhi (India)

    1999-07-01

    Apoptosis or programmed cell death is a highly conserved genetically controlled response of metazoan cells to commit suicide. Non apoptotic programmed cell death seems to operate in single celled eukaryotes implying that evolution of PCD has preceded the evolution of multicellularity. PCD plays a crucial role in the regulation of cellular and tissue homeostasis and any aberrations in apoptosis leads to several diseases including cancer, neurodegenerative disorders and AIDS. The mechanisms by which apoptosis is controlled are varied. In some cells, members of bcl-2 family or p53 are crucial for regulating the apoptosis programme, whereas in other cells Fas ligand is more important. bcl-2 family members have a prime role in the regulation of cell death at all stages including development, whereas cell death during development is independent of p53. bcl-2 family members being localized on the outer mitochondrial membrane, control the mitochondrial homeostasis and cytochrome c redistribution and thereby regulate the cell death process. p53 promotes DNA damage mediated cell death after growth arrest and failed DNA repair. Caspases play a key role in the execution of cell death by mediating highly specific cleavages of crucial cellular proteins collectivley manifesting the apoptotic phenotype. Protein inhibitors like crm A, p35 and IAPs could prevent/control apoptosis induced by a broad array of cell death stimuli by several mechanisms specially interfering in caspase activation or caspase activity. Among endonucleases, caspase activated DNase (CAD) plays a crucial role in DNA fragmentation, a biochemical hallmark of apoptosis. As regulation of cell death seems to be as complex as regulation of cell proliferation, multiple kinase mediated regulatory mechanisms might control the apoptotic process. Thus, in spite of intensive research over the past few years, the field of apoptosis still remains fertile to unravel among others, the molecular mechanisms of cytochrome c

  19. Autophagic components contribute to hypersensitive cell death in Arabidopsis

    DEFF Research Database (Denmark)

    Hofius, Daniel; Schultz-Larsen, Torsten; Joensen, Jan

    2009-01-01

    Autophagy has been implicated as a prosurvival mechanism to restrict programmed cell death (PCD) associated with the pathogen-triggered hypersensitive response (HR) during plant innate immunity. This model is based on the observation that HR lesions spread in plants with reduced autophagy gene...... expression. Here, we examined receptor-mediated HR PCD responses in autophagy-deficient Arabidopsis knockout mutants (atg), and show that infection-induced lesions are contained in atg mutants. We also provide evidence that HR cell death initiated via Toll/Interleukin-1 (TIR)-type immune receptors through...... the defense regulator EDS1 is suppressed in atg mutants. Furthermore, we demonstrate that PCD triggered by coiled-coil (CC)-type immune receptors via NDR1 is either autophagy-independent or engages autophagic components with cathepsins and other unidentified cell death mediators. Thus, autophagic cell death...

  20. Guidelines and recommendations on yeast cell death nomenclature

    OpenAIRE

    Carmona-Gutierrez, Didac; Bauer, Maria Anna; Zimmermann, Andreas; Aguilera, Andres; Austriaco, Nicanor; Sigrist, Stephan J.

    2018-01-01

    Elucidating the biology of yeast in its full complexity has major implications for science, medicine and industry. One of the most critical processes determining yeast life and physiology is cellular demise. However, the investigation of yeast cell death is a relatively young field, and a widely accepted set of concepts and terms is still missing. Here, we propose unified criteria for the definition of accidental, regulated, and programmed forms of cell death in yeast based on a series of mor...

  1. Nerve Growth Factor in Cancer Cell Death and Survival

    Energy Technology Data Exchange (ETDEWEB)

    Molloy, Niamh H.; Read, Danielle E.; Gorman, Adrienne M., E-mail: adrienne.gorman@nuigalway.ie [Apoptosis Research Centre, School of Natural Sciences, National University of Ireland, Galway (Ireland)

    2011-02-01

    One of the major challenges for cancer therapeutics is the resistance of many tumor cells to induction of cell death due to pro-survival signaling in the cancer cells. Here we review the growing literature which shows that neurotrophins contribute to pro-survival signaling in many different types of cancer. In particular, nerve growth factor, the archetypal neurotrophin, has been shown to play a role in tumorigenesis over the past decade. Nerve growth factor mediates its effects through its two cognate receptors, TrkA, a receptor tyrosine kinase and p75{sup NTR}, a member of the death receptor superfamily. Depending on the tumor origin, pro-survival signaling can be mediated by TrkA receptors or by p75{sup NTR}. For example, in breast cancer the aberrant expression of nerve growth factor stimulates proliferative signaling through TrkA and pro-survival signaling through p75{sup NTR}. This latter signaling through p75{sup NTR} promotes increased resistance to the induction of cell death by chemotherapeutic treatments. In contrast, in prostate cells the p75{sup NTR} mediates cell death and prevents metastasis. In prostate cancer, expression of this receptor is lost, which contributes to tumor progression by allowing cells to survive, proliferate and metastasize. This review focuses on our current knowledge of neurotrophin signaling in cancer, with a particular emphasis on nerve growth factor regulation of cell death and survival in cancer.

  2. Nerve Growth Factor in Cancer Cell Death and Survival

    International Nuclear Information System (INIS)

    Molloy, Niamh H.; Read, Danielle E.; Gorman, Adrienne M.

    2011-01-01

    One of the major challenges for cancer therapeutics is the resistance of many tumor cells to induction of cell death due to pro-survival signaling in the cancer cells. Here we review the growing literature which shows that neurotrophins contribute to pro-survival signaling in many different types of cancer. In particular, nerve growth factor, the archetypal neurotrophin, has been shown to play a role in tumorigenesis over the past decade. Nerve growth factor mediates its effects through its two cognate receptors, TrkA, a receptor tyrosine kinase and p75 NTR , a member of the death receptor superfamily. Depending on the tumor origin, pro-survival signaling can be mediated by TrkA receptors or by p75 NTR . For example, in breast cancer the aberrant expression of nerve growth factor stimulates proliferative signaling through TrkA and pro-survival signaling through p75 NTR . This latter signaling through p75 NTR promotes increased resistance to the induction of cell death by chemotherapeutic treatments. In contrast, in prostate cells the p75 NTR mediates cell death and prevents metastasis. In prostate cancer, expression of this receptor is lost, which contributes to tumor progression by allowing cells to survive, proliferate and metastasize. This review focuses on our current knowledge of neurotrophin signaling in cancer, with a particular emphasis on nerve growth factor regulation of cell death and survival in cancer

  3. The process and promotion of radiation-induced cell death

    International Nuclear Information System (INIS)

    Sasaki, Hiroshi

    1998-01-01

    Radiation-induced cell death is divided into reproductive and interphase death, whose process can be revealed by time-lapse observations. Pedigree analyses of progenies derived from a surviving progenitor cell have shown that moribund cells appear in clusters among cells which are apparently undamaged (lethal sectoring). Sister cell fusion, which likely results from chromosome bridge, is the most frequently observed cell abnormality leading to reproductive death. While interphase death does not occur unless the dose exceeds 10 Gy for low LET radiation such as X-rays, high-LET radiation is very effective at inducing interphase death (RBE: ≅3 at 230 keV/μm). Expression or fixation of potentially lethal damage (PLD) is closely associated with cell cycle events and enhanced by inducing premature chromosome condensation (PCC) at a nonpermissive temperature in tsBN2 cells with a ts-defect in RCC1 protein (a regulator of chromatin condensation) which monitors the completion of DNA replication. Furthermore, higher-order structural changes in nuclear matrix such as induced by leptomycin B, an inhibitor of CRM1 (chromosome region maintenance) protein, also play an important role in the fixation of PLD. (author)

  4. BID links ferroptosis to mitochondrial cell death pathways.

    Science.gov (United States)

    Neitemeier, Sandra; Jelinek, Anja; Laino, Vincenzo; Hoffmann, Lena; Eisenbach, Ina; Eying, Roman; Ganjam, Goutham K; Dolga, Amalia M; Oppermann, Sina; Culmsee, Carsten

    2017-08-01

    Ferroptosis has been defined as an oxidative and iron-dependent pathway of regulated cell death that is distinct from caspase-dependent apoptosis and established pathways of death receptor-mediated regulated necrosis. While emerging evidence linked features of ferroptosis induced e.g. by erastin-mediated inhibition of the X c - system or inhibition of glutathione peroxidase 4 (Gpx4) to an increasing number of oxidative cell death paradigms in cancer cells, neurons or kidney cells, the biochemical pathways of oxidative cell death remained largely unclear. In particular, the role of mitochondrial damage in paradigms of ferroptosis needs further investigation. In the present study, we find that erastin-induced ferroptosis in neuronal cells was accompanied by BID transactivation to mitochondria, loss of mitochondrial membrane potential, enhanced mitochondrial fragmentation and reduced ATP levels. These hallmarks of mitochondrial demise are also established features of oxytosis, a paradigm of cell death induced by X c - inhibition by millimolar concentrations of glutamate. Bid knockout using CRISPR/Cas9 approaches preserved mitochondrial integrity and function, and mediated neuroprotective effects against both, ferroptosis and oxytosis. Furthermore, the BID-inhibitor BI-6c9 inhibited erastin-induced ferroptosis, and, in turn, the ferroptosis inhibitors ferrostatin-1 and liproxstatin-1 prevented mitochondrial dysfunction and cell death in the paradigm of oxytosis. These findings show that mitochondrial transactivation of BID links ferroptosis to mitochondrial damage as the final execution step in this paradigm of oxidative cell death. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  5. THE PROGRAMED CELL DEATH REGULATORS OF ISOLATED MODEL SYSTEMS

    Directory of Open Access Journals (Sweden)

    D. V. Vatlitsov

    2016-06-01

    Full Text Available The technology evolution creates the prerequisites for the emergence of new informational concept and approaches to the formation of a fundamentally new principles of biological objects understanding. The aim was to study the activators of the programmed cell death in an isolated system model. Cell culture aging parameters were performed on flow cytometer. It had formed the theory that the changes in the concentrations of metal ions and increase their extracellular concentration had formed a negative gradient into the cells.regulation of cell death. It was shown that the metals ions concentrations.

  6. Understanding cell cycle and cell death regulation provides novel weapons against human diseases.

    Science.gov (United States)

    Wiman, K G; Zhivotovsky, B

    2017-05-01

    Cell division, cell differentiation and cell death are the three principal physiological processes that regulate tissue homoeostasis in multicellular organisms. The growth and survival of cells as well as the integrity of the genome are regulated by a complex network of pathways, in which cell cycle checkpoints, DNA repair and programmed cell death have critical roles. Disruption of genomic integrity and impaired regulation of cell death may both lead to uncontrolled cell growth. Compromised cell death can also favour genomic instability. It is becoming increasingly clear that dysregulation of cell cycle and cell death processes plays an important role in the development of major disorders such as cancer, cardiovascular disease, infection, inflammation and neurodegenerative diseases. Research achievements in these fields have led to the development of novel approaches for treatment of various conditions associated with abnormalities in the regulation of cell cycle progression or cell death. A better understanding of how cellular life-and-death processes are regulated is essential for this development. To highlight these important advances, the Third Nobel Conference entitled 'The Cell Cycle and Cell Death in Disease' was organized at Karolinska Institutet in 2016. In this review we will summarize current understanding of cell cycle progression and cell death and discuss some of the recent advances in therapeutic applications in pathological conditions such as cancer, neurological disorders and inflammation. © 2017 The Association for the Publication of the Journal of Internal Medicine.

  7. Expression of death receptor 4 induces caspase-independent cell death in MMS-treated yeast.

    Science.gov (United States)

    Kang, Mi-Sun; Lee, Sung-Keun; Park, Chang-Shin; Kang, Ju-Hee; Bae, Sung-Ho; Yu, Sung-Lim

    2008-11-14

    DR4, a tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) receptor, is a key element in the extrinsic pathway of TRAIL/TRAIL receptor-related apoptosis that exerts a preferential toxic effect against tumor cells. However, TRAIL and DR4 are expressed in various normal cells, and recent studies indicate that DR4 has a number of non-apoptotic functions. In this study, we evaluated the effects of human DR4 expression in yeast to determine the function of DR4 in normal cells. The expression of DR4 in yeast caused G1 arrest, which resulted in transient growth inhibition. Moreover, treatment of DR4-expressing yeast with a DNA damaging agent, MMS, elicited drastic, and sustained cell growth inhibition accompanied with massive apoptotic cell death. Further analysis revealed that cell death in the presence of DNA damage and DR4 expression was not dependent on the yeast caspase, YCA1. Taken together, these results indicate that DR4 triggers caspase-independent programmed cell death during the response of normal cells to DNA damage.

  8. Vacuolar processing enzyme: an executor of plant cell death.

    Science.gov (United States)

    Hara-Nishimura, Ikuko; Hatsugai, Noriyuki; Nakaune, Satoru; Kuroyanagi, Miwa; Nishimura, Mikio

    2005-08-01

    Apoptotic cell death in animals is regulated by cysteine proteinases called caspases. Recently, vacuolar processing enzyme (VPE) was identified as a plant caspase. VPE deficiency prevents cell death during hypersensitive response and cell death of limited cell layers at the early stage of embryogenesis. Because plants do not have macrophages, dying cells must degrade their materials by themselves. VPE plays an essential role in the regulation of the lytic system of plants during the processes of defense and development. VPE is localized in the vacuoles, unlike animal caspases, which are localized in the cytosol. Thus, plants might have evolved a regulated cellular suicide strategy that, unlike animal apoptosis, is mediated by VPE and the vacuoles.

  9. Early cell death detection with digital holographic microscopy.

    Directory of Open Access Journals (Sweden)

    Nicolas Pavillon

    Full Text Available BACKGROUND: Digital holography provides a non-invasive measurement of the quantitative phase shifts induced by cells in culture, which can be related to cell volume changes. It has been shown previously that regulation of cell volume, in particular as it relates to ionic homeostasis, is crucially involved in the activation/inactivation of the cell death processes. We thus present here an application of digital holographic microscopy (DHM dedicated to early and label-free detection of cell death. METHODS AND FINDINGS: We provide quantitative measurements of phase signal obtained on mouse cortical neurons, and caused by early neuronal cell volume regulation triggered by excitotoxic concentrations of L-glutamate. We show that the efficiency of this early regulation of cell volume detected by DHM, is correlated with the occurrence of subsequent neuronal death assessed with the widely accepted trypan blue method for detection of cell viability. CONCLUSIONS: The determination of the phase signal by DHM provides a simple and rapid optical method for the early detection of cell death.

  10. Porcine circovirus-2 capsid protein induces cell death in PK15 cells

    Energy Technology Data Exchange (ETDEWEB)

    Walia, Rupali; Dardari, Rkia, E-mail: rdardari@ucalgary.ca; Chaiyakul, Mark; Czub, Markus

    2014-11-15

    Studies have shown that Porcine circovirus (PCV)-2 induces apoptosis in PK15 cells. Here we report that cell death is induced in PCV2b-infected PK15 cells that express Capsid (Cap) protein and this effect is enhanced in interferon gamma (IFN-γ)-treated cells. We further show that transient PCV2a and 2b-Cap protein expression induces cell death in PK15 cells at rate similar to PCV2 infection, regardless of Cap protein localization. These data suggest that Cap protein may have the capacity to trigger different signaling pathways involved in cell death. Although further investigation is needed to gain deeper insights into the nature of the pathways involved in Cap-induced cell death, this study provides evidence that PCV2-induced cell death in kidney epithelial PK15 cells can be mapped to the Cap protein and establishes the need for future research regarding the role of Cap-induced cell death in PCV2 pathogenesis. - Highlights: • IFN-γ enhances PCV2 replication that leads to cell death in PK15 cells. • IFN-γ enhances nuclear localization of the PCV2 Capsid protein. • Transient PCV2a and 2b-Capsid protein expression induces cell death. • Cell death is not dictated by specific Capsid protein sub-localization.

  11. Photothermal reshaping of gold nanorods prevents further cell death

    International Nuclear Information System (INIS)

    Takahashi, Hironobu; Niidome, Takuro; Nariai, Ayuko; Niidome, Yasuro; Yamada, Sunao

    2006-01-01

    The combined use of phosphatidylcholine passivated gold nanorods (PC-NRs) and pulsed near-infrared (near-IR) irradiation resulted in cell death. Pulsed near-IR laser irradiation also induced reshaping of PC-NRs into spherical nanoparticles. Since reshaped particles showed no absorption in the near-IR region, successive laser irradiation did not affect cells. Photo-reshaping of PC-NRs is expected to be advantageous in preventing unwanted cell damage following destruction of target cells

  12. Therapeutic approaches to preventing cell death in Huntington disease.

    Science.gov (United States)

    Kaplan, Anna; Stockwell, Brent R

    2012-12-01

    Neurodegenerative diseases affect the lives of millions of patients and their families. Due to the complexity of these diseases and our limited understanding of their pathogenesis, the design of therapeutic agents that can effectively treat these diseases has been challenging. Huntington disease (HD) is one of several neurological disorders with few therapeutic options. HD, like numerous other neurodegenerative diseases, involves extensive neuronal cell loss. One potential strategy to combat HD and other neurodegenerative disorders is to intervene in the execution of neuronal cell death. Inhibiting neuronal cell death pathways may slow the development of neurodegeneration. However, discovering small molecule inhibitors of neuronal cell death remains a significant challenge. Here, we review candidate therapeutic targets controlling cell death mechanisms that have been the focus of research in HD, as well as an emerging strategy that has been applied to developing small molecule inhibitors-fragment-based drug discovery (FBDD). FBDD has been successfully used in both industry and academia to identify selective and potent small molecule inhibitors, with a focus on challenging proteins that are not amenable to traditional high-throughput screening approaches. FBDD has been used to generate potent leads, pre-clinical candidates, and has led to the development of an FDA approved drug. This approach can be valuable for identifying modulators of cell-death-regulating proteins; such compounds may prove to be the key to halting the progression of HD and other neurodegenerative disorders. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Cylindromatosis mediates neuronal cell death in vitro and in vivo.

    Science.gov (United States)

    Ganjam, Goutham K; Terpolilli, Nicole Angela; Diemert, Sebastian; Eisenbach, Ina; Hoffmann, Lena; Reuther, Christina; Herden, Christiane; Roth, Joachim; Plesnila, Nikolaus; Culmsee, Carsten

    2018-01-19

    The tumor-suppressor cylindromatosis (CYLD) is a deubiquitinating enzyme and key regulator of cell proliferation and inflammation. A genome-wide siRNA screen linked CYLD to receptor interacting protein-1 (RIP1) kinase-mediated necroptosis; however, the exact mechanisms of CYLD-mediated cell death remain unknown. Therefore, we investigated the precise role of CYLD in models of neuronal cell death in vitro and evaluated whether CYLD deletion affects brain injury in vivo. In vitro, downregulation of CYLD increased RIP1 ubiquitination, prevented RIP1/RIP3 complex formation, and protected neuronal cells from oxidative death. Similar protective effects were achieved by siRNA silencing of RIP1 or RIP3 or by pharmacological inhibition of RIP1 with necrostatin-1. In vivo, CYLD knockout mice were protected from trauma-induced brain damage compared to wild-type littermate controls. These findings unravel the mechanisms of CYLD-mediated cell death signaling in damaged neurons in vitro and suggest a cell death-mediating role of CYLD in vivo.

  14. Staurosporine induces different cell death forms in cultured rat astrocytes

    International Nuclear Information System (INIS)

    Simenc, Janez; Lipnik-Stangelj, Metoda

    2012-01-01

    Astroglial cells are frequently involved in malignant transformation. Besides apoptosis, necroptosis, a different form of regulated cell death, seems to be related with glioblastoma genesis, proliferation, angiogenesis and invasion. In the present work we elucidated mechanisms of necroptosis in cultured astrocytes, and compared them with apoptosis, caused by staurosporine. Cultured rat cortical astrocytes were used for a cell death studies. Cell death was induced by different concentrations of staurosporine, and modified by inhibitors of apoptosis (z-vad-fmk) and necroptosis (nec-1). Different forms of a cell death were detected using flow cytometry. We showed that staurosporine, depending on concentration, induces both, apoptosis as well as necroptosis. Treatment with 10 −7 M staurosporine increased apoptosis of astrocytes after the regeneration in a staurosporine free medium. When caspases were inhibited, apoptosis was attenuated, while necroptosis was slightly increased. Treatment with 10 −6 M staurosporine induced necroptosis that occurred after the regeneration of astrocytes in a staurosporine free medium, as well as without regeneration period. Necroptosis was significantly attenuated by nec-1 which inhibits RIP1 kinase. On the other hand, the inhibition of caspases had no effect on necroptosis. Furthermore, staurosporine activated RIP1 kinase increased the production of reactive oxygen species, while an antioxidant BHA significantly attenuated necroptosis. Staurosporine can induce apoptosis and/or necroptosis in cultured astrocytes via different signalling pathways. Distinction between different forms of cell death is crucial in the studies of therapy-induced necroptosis

  15. The Apoptosome: Heart and Soul of the Cell Death Machine

    Directory of Open Access Journals (Sweden)

    Arul M. Chinnaiyan

    1999-04-01

    Full Text Available Apoptosis is a fundamental biologic process by which metazoan cells orchestrate their own self-demise. Genetic analyses of the nematode C elegans identified three core components of the suicide apparatus which include CED-3, CED-4, and CED-9. An analogous set of core constituents exists in mammalian cells and includes caspase-9, Apaf-1, and bcl-2/xL, respectively. CED-3 and CED-4, along with their mammalian counterparts, function to kill cells, whereas CED-9 and its mammalian equivalents protect cells from death. These central components biochemically intermingle in a ternary complex recently dubbed the “apoptosome.” The C elegans protein EGL-1 and its mammalian counterparts, pro-apoptotic members of the bcl-2 family, induce cell death by disrupting apoptosome interactions. Thus, EGL-1 may represent a primordial signal integrator for the apoptosome. Various biochemical processes including oligomerization, adenosine triphosphate ATP/dATP binding, and cytochrome c interaction play a role in regulating the ternary death complex. Recent studies suggest that cell death receptors, such as CD95, may amplify their suicide signal by activating the apoptosome. These mutual associations by core components of the suicide apparatus provide a molecular framework in which diverse death signals likely interface. Understanding the apoptosome and its cellular connections will facilitate the design of novel therapeutic strategies for cancer and other disease states in which apoptosis plays a pivotal role.

  16. Cardiac Glycoside Glucoevatromonoside Induces Cancer Type-Specific Cell Death

    Directory of Open Access Journals (Sweden)

    Naira F. Z. Schneider

    2018-03-01

    Full Text Available Cardiac glycosides (CGs are natural compounds used traditionally to treat congestive heart diseases. Recent investigations repositioned CGs as potential anticancer agents. To discover novel cytotoxic CG scaffolds, we selected the cardenolide glucoevatromonoside (GEV out of 46 CGs for its low nanomolar anti-lung cancer activity. GEV presented reduced toxicity toward non-cancerous cell types (lung MRC-5 and PBMC and high-affinity binding to the Na+/K+-ATPase α subunit, assessed by computational docking. GEV-induced cell death was caspase-independent, as investigated by a multiparametric approach, and culminates in severe morphological alterations in A549 cells, monitored by transmission electron microscopy, live cell imaging and flow cytometry. This non-canonical cell death was not preceded or accompanied by exacerbation of autophagy. In the presence of GEV, markers of autophagic flux (e.g. LC3I-II conversion were impacted, even in presence of bafilomycin A1. Cell death induction remained unaffected by calpain, cathepsin, parthanatos, or necroptosis inhibitors. Interestingly, GEV triggered caspase-dependent apoptosis in U937 acute myeloid leukemia cells, witnessing cancer-type specific cell death induction. Differential cell cycle modulation by this CG led to a G2/M arrest, cyclin B1 and p53 downregulation in A549, but not in U937 cells. We further extended the anti-cancer potential of GEV to 3D cell culture using clonogenic and spheroid formation assays and validated our findings in vivo by zebrafish xenografts. Altogether, GEV shows an interesting anticancer profile with the ability to exert cytotoxic effects via induction of different cell death modalities.

  17. Cancer resistance in the blind mole rat is mediated by concerted necrotic cell death mechanism

    Science.gov (United States)

    Gorbunova, Vera; Hine, Christopher; Tian, Xiao; Ablaeva, Julia; Gudkov, Andrei V.; Nevo, Eviatar; Seluanov, Andrei

    2012-01-01

    Blind mole rats Spalax (BMR) are small subterranean rodents common in the Middle East. BMR is distinguished by its adaptations to life underground, remarkable longevity (with a maximum documented lifespan of 21 y), and resistance to cancer. Spontaneous tumors have never been observed in spalacids. To understand the mechanisms responsible for this resistance, we examined the growth of BMR fibroblasts in vitro of the species Spalax judaei and Spalax golani. BMR cells proliferated actively for 7–20 population doublings, after which the cells began secreting IFN-β, and the cultures underwent massive necrotic cell death within 3 d. The necrotic cell death phenomenon was independent of culture conditions or telomere shortening. Interestingly, this cell behavior was distinct from that observed in another long-lived and cancer-resistant African mole rat, Heterocephalus glaber, the naked mole rat in which cells display hypersensitivity to contact inhibition. Sequestration of p53 and Rb proteins using SV40 large T antigen completely rescued necrotic cell death. Our results suggest that cancer resistance of BMR is conferred by massive necrotic response to overproliferation mediated by p53 and Rb pathways, and triggered by the release of IFN-β. Thus, we have identified a unique mechanism that contributes to cancer resistance of this subterranean mammal extremely adapted to life underground. PMID:23129611

  18. Mitochondrial regulation of cell death: a phylogenetically conserved control

    Directory of Open Access Journals (Sweden)

    Lorenzo Galluzzi

    2016-02-01

    Full Text Available Mitochondria are fundamental for eukaryotic cells as they participate in critical catabolic and anabolic pathways. Moreover, mitochondria play a key role in the signal transduction cascades that precipitate many (but not all regulated variants of cellular demise. In this short review, we discuss the differential implication of mitochondria in the major forms of regulated cell death.

  19. Deaths of cancer cells observed after X-Ray irradiation

    International Nuclear Information System (INIS)

    Kuwahara, Yoshikazu; Oikawa, Toshiyuki; Ochiai, Yasushi; Fukumoto, Motoi; Kurihara, Ai; Noma, Naoto; Shimura, Tsutomu; Fukumoto, Manabu; Ohkubo, Yasuhito

    2011-01-01

    Radiation induces cell death by apoptosis, autophagy (autophagic cell death, APCD), necrosis, which are respectively called type I, II, III programmed cell death, senescence, mitotic catastrophe, etc. This paper mainly describes details of authors' studies on APCD of clinically relevant radioresistant (CRR) HepG2-8960-R cells established from proliferating survivor even after repeated X-irradiation of >30 days x 2 Gy/day to the parent HepG2 cells. Autophagy forms autophagosome where many proteins are thoroughly degraded differing from proteasomal ubiquitin system, has been known essentially related to death and survival of injured cells under certain tissue conditions, and is distinguishable from other modes of cell death by morphological and cytochemical means. One of important authors' findings is as follows. APCD of CRR cells is normally seen in 20% and of the parent strain, 5%. When they are X-irradiated at 10 Gy, APCD of the latter is more (70%) than the former (40%), and no APCD is induced by 2 Gy x 5 days in the former in contrast to the latter. APCD by radiation is thus conceivably suppressed in CRR cells, suggesting that their radioresistance can be reversed by treatment to induce APCD. Autophagy is usually suppressed by mammalian target of rapamycin (mTOR), and when CRR cells are treated with rapamycin, they become radiosensitive to the comparable level to the parent HepG2. When HepG2 cells are treated with 3-methyladenine, an inhibitor of autophagy, or Beclin siRNA, they become radioresistant. For effectiveness of APCD induction and suppression on cancer therapy, results are contradictory in certain reports and autophagy should be a problem to be further elucidated from radiation biology aspect. (author)

  20. Signal transduction events in aluminum-induced cell death in tomato suspension cells

    NARCIS (Netherlands)

    Iakimova, E.T.; Kapchina-Toteva, V.M.; Woltering, E.J.

    2007-01-01

    In this study, some of the signal transduction events involved in AlCl3-induced cell death in tomato (Lycopersicon esculentum Mill.) suspension cells were elucidated. Cells treated with 100 ¿M AlCl3 showed typical features of programmed cell death (PCD) such as nuclear and cytoplasmic condensation.

  1. Guidelines and recommendations on yeast cell death nomenclature

    Directory of Open Access Journals (Sweden)

    Didac Carmona-Gutierrez

    2018-01-01

    Full Text Available Elucidating the biology of yeast in its full complexity has major implications for science, medicine and industry. One of the most critical processes determining yeast life and physiology is cellular demise. However, the investigation of yeast cell death is a relatively young field, and a widely accepted set of concepts and terms is still missing. Here, we propose unified criteria for the definition of accidental, regulated, and programmed forms of cell death in yeast based on a series of morphological and biochemical criteria. Specifically, we provide consensus guidelines on the differential definition of terms including apoptosis, regulated necrosis, and autophagic cell death, as we refer to additional cell death routines that are relevant for the biology of (at least some species of yeast. As this area of investigation advances rapidly, changes and extensions to this set of recommendations will be implemented in the years to come. Nonetheless, we strongly encourage the authors, reviewers and editors of scientific articles to adopt these collective standards in order to establish an accurate framework for yeast cell death research and, ultimately, to accelerate the progress of this vibrant field of research.

  2. Guidelines and recommendations on yeast cell death nomenclature

    Science.gov (United States)

    Carmona-Gutierrez, Didac; Bauer, Maria Anna; Zimmermann, Andreas; Aguilera, Andrés; Austriaco, Nicanor; Ayscough, Kathryn; Balzan, Rena; Bar-Nun, Shoshana; Barrientos, Antonio; Belenky, Peter; Blondel, Marc; Braun, Ralf J.; Breitenbach, Michael; Burhans, William C.; Büttner, Sabrina; Cavalieri, Duccio; Chang, Michael; Cooper, Katrina F.; Côrte-Real, Manuela; Costa, Vítor; Cullin, Christophe; Dawes, Ian; Dengjel, Jörn; Dickman, Martin B.; Eisenberg, Tobias; Fahrenkrog, Birthe; Fasel, Nicolas; Fröhlich, Kai-Uwe; Gargouri, Ali; Giannattasio, Sergio; Goffrini, Paola; Gourlay, Campbell W.; Grant, Chris M.; Greenwood, Michael T.; Guaragnella, Nicoletta; Heger, Thomas; Heinisch, Jürgen; Herker, Eva; Herrmann, Johannes M.; Hofer, Sebastian; Jiménez-Ruiz, Antonio; Jungwirth, Helmut; Kainz, Katharina; Kontoyiannis, Dimitrios P.; Ludovico, Paula; Manon, Stéphen; Martegani, Enzo; Mazzoni, Cristina; Megeney, Lynn A.; Meisinger, Chris; Nielsen, Jens; Nyström, Thomas; Osiewacz, Heinz D.; Outeiro, Tiago F.; Park, Hay-Oak; Pendl, Tobias; Petranovic, Dina; Picot, Stephane; Polčic, Peter; Powers, Ted; Ramsdale, Mark; Rinnerthaler, Mark; Rockenfeller, Patrick; Ruckenstuhl, Christoph; Schaffrath, Raffael; Segovia, Maria; Severin, Fedor F.; Sharon, Amir; Sigrist, Stephan J.; Sommer-Ruck, Cornelia; Sousa, Maria João; Thevelein, Johan M.; Thevissen, Karin; Titorenko, Vladimir; Toledano, Michel B.; Tuite, Mick; Vögtle, F.-Nora; Westermann, Benedikt; Winderickx, Joris; Wissing, Silke; Wölfl, Stefan; Zhang, Zhaojie J.; Zhao, Richard Y.; Zhou, Bing; Galluzzi, Lorenzo; Kroemer, Guido; Madeo, Frank

    2018-01-01

    Elucidating the biology of yeast in its full complexity has major implications for science, medicine and industry. One of the most critical processes determining yeast life and physiology is cellular demise. However, the investigation of yeast cell death is a relatively young field, and a widely accepted set of concepts and terms is still missing. Here, we propose unified criteria for the definition of accidental, regulated, and programmed forms of cell death in yeast based on a series of morphological and biochemical criteria. Specifically, we provide consensus guidelines on the differential definition of terms including apoptosis, regulated necrosis, and autophagic cell death, as we refer to additional cell death routines that are relevant for the biology of (at least some species of) yeast. As this area of investigation advances rapidly, changes and extensions to this set of recommendations will be implemented in the years to come. Nonetheless, we strongly encourage the authors, reviewers and editors of scientific articles to adopt these collective standards in order to establish an accurate framework for yeast cell death research and, ultimately, to accelerate the progress of this vibrant field of research. PMID:29354647

  3. Jasmonic acid signaling modulates ozone-induced hypersensitive cell death.

    Science.gov (United States)

    Rao, M V; Lee, H; Creelman, R A; Mullet, J E; Davis, K R

    2000-09-01

    Recent studies suggest that cross-talk between salicylic acid (SA)-, jasmonic acid (JA)-, and ethylene-dependent signaling pathways regulates plant responses to both abiotic and biotic stress factors. Earlier studies demonstrated that ozone (O(3)) exposure activates a hypersensitive response (HR)-like cell death pathway in the Arabidopsis ecotype Cvi-0. We now have confirmed the role of SA and JA signaling in influencing O(3)-induced cell death. Expression of salicylate hydroxylase (NahG) in Cvi-0 reduced O(3)-induced cell death. Methyl jasmonate (Me-JA) pretreatment of Cvi-0 decreased O(3)-induced H(2)O(2) content and SA concentrations and completely abolished O(3)-induced cell death. Cvi-0 synthesized as much JA as did Col-0 in response to O(3) exposure but exhibited much less sensitivity to exogenous Me-JA. Analyses of the responses to O(3) of the JA-signaling mutants jar1 and fad3/7/8 also demonstrated an antagonistic relationship between JA- and SA-signaling pathways in controlling the magnitude of O(3)-induced HR-like cell death.

  4. Cell death and autophagy: Cytokines, drugs, and nutritional factors

    International Nuclear Information System (INIS)

    Bursch, Wilfried; Karwan, Anneliese; Mayer, Miriam; Dornetshuber, Julia; Froehwein, Ulrike; Schulte-Hermann, Rolf; Fazi, Barbara; Di Sano, Federica; Piredda, Lucia; Piacentini, Mauro; Petrovski, Goran; Fesues, Laszlo; Gerner, Christopher

    2008-01-01

    Cells may use multiple pathways to commit suicide. In certain contexts, dying cells generate large amounts of autophagic vacuoles and clear large proportions of their cytoplasm, before they finally die, as exemplified by the treatment of human mammary carcinoma cells with the anti-estrogen tamoxifen (TAM, ≤1 μM). Protein analysis during autophagic cell death revealed distinct proteins of the nuclear fraction including GST-π and some proteasomal subunit constituents to be affected during autophagic cell death. Depending on the functional status of caspase-3, MCF-7 cells may switch between autophagic and apoptotic features of cell death [Fazi, B., Bursch, W., Fimia, G.M., Nardacci R., Piacentini, M., Di Sano, F., Piredda, L., 2008. Fenretinide induces autophagic cell death in caspase-defective breast cancer cells. Autophagy 4(4), 435-441]. Furthermore, the self-destruction of MCF-7 cells was found to be completed by phagocytosis of cell residues [Petrovski, G., Zahuczky, G., Katona, K., Vereb, G., Martinet, W., Nemes, Z., Bursch, W., Fesues, L., 2007. Clearance of dying autophagic cells of different origin by professional and non-professional phagocytes. Cell Death Diff. 14 (6), 1117-1128]. Autophagy also constitutes a cell's strategy of defense upon cell damage by eliminating damaged bulk proteins/organelles. This biological condition may be exemplified by the treatment of MCF-7 cells with a necrogenic TAM-dose (10 μM), resulting in the lysis of almost all cells within 24 h. However, a transient (1 h) challenge of MCF-7 cells with the same dose allowed the recovery of cells involving autophagy. Enrichment of chaperones in the insoluble cytoplasmic protein fraction indicated the formation of aggresomes, a potential trigger for autophagy. In a further experimental model HL60 cells were treated with TAM, causing dose-dependent distinct responses: 1-5 μM TAM, autophagy predominant; 7-9 μM, apoptosis predominant; 15 μM, necrosis. These phenomena might be

  5. Non-apoptotic cell death associated with perturbations of macropinocytosis.

    Science.gov (United States)

    Maltese, William A; Overmeyer, Jean H

    2015-01-01

    Although macropinocytosis is widely recognized as a distinct form of fluid-phase endocytosis in antigen-presenting dendritic cells, it also occurs constitutively in many other normal and transformed cell types. Recent studies have established that various genetic or pharmacological manipulations can hyperstimulate macropinocytosis or disrupt normal macropinosome trafficking pathways, leading to accumulation of greatly enlarged cytoplasmic vacuoles. In some cases, this extreme vacuolization is associated with a unique form of non-apoptotic cell death termed "methuosis," from the Greek methuo (to drink to intoxication). It remains unclear whether cell death related to dysfunctional macropinocytosis occurs in normal physiological contexts. However, the finding that some types of cancer cells are particularly vulnerable to this unusual form of cell death has raised the possibility that small molecules capable of altering macropinosome trafficking or function might be useful as therapeutic agents against cancers that are resistant to drugs that work by inducing apoptosis. Herein we review examples of cell death associated with dysfunctional macropinocytosis and summarize what is known about the underlying mechanisms.

  6. Non-apoptotic cell death associated with perturbations of macropinocytosis

    Directory of Open Access Journals (Sweden)

    William A. Maltese

    2015-02-01

    Full Text Available Although macropinocytosis is widely recognized as a distinct form of fluid-phase endocytosis in antigen-presenting dendritic cells, it also occurs constitutively in many other normal and transformed cell types. Recent studies have established that various genetic or pharmacological manipulations can hyperstimulate macropinocytosis or disrupt normal macropinosome trafficking pathways, leading to accumulation of greatly enlarged cytoplasmic vacuoles. In some cases, this extreme vacuolization is associated with a unique form of non-apoptotic cell death termed ‘methuosis’, from the Greek methuo (to drink to intoxication. It remains unclear whether cell death related to dysfunctional macropinocytosis occurs in normal physiological contexts. However, the finding that some types of cancer cells are particularly vulnerable to this unusual form of cell death has raised the possibility that small molecules capable of altering macropinosome trafficking or function might be useful as therapeutic agents against cancers that are resistant to drugs that work by inducing apoptosis. Herein we review examples of cell death associated with dysfunctional macropinocytosis and summarize what is known about the underlying mechanisms.

  7. C/EBPβ LIP augments cell death by inducing osteoglycin.

    Science.gov (United States)

    Wassermann-Dozorets, Rina; Rubinstein, Menachem

    2017-04-06

    Many types of tumor cell are devoid of the extracellular matrix proteoglycan osteoglycin (Ogn), but its role in tumor biology is poorly studied. Here we show that RNAi of Ogn attenuates stress-triggered cell death, whereas its overexpression increases cell death. We found that the transcription factor C/EBPβ regulates the expression of Ogn. C/EBPβ is expressed as a full-length, active form (LAP) and as a truncated, dominant-negative form (LIP), and the LIP/LAP ratio is positively correlated with the extent of cell death under stress. For example, we reported that drug-resistant tumor cells lack LIP altogether, and its supplementation abolished their resistance to chemotherapy and to endoplasmic reticulum (ER) stress. Here we further show that elevated LIP/LAP ratio robustly increased Ogn expression and cell death under stress by modulating the mitogen-activated protein kinase/activator protein 1 pathway (MAPK/AP-1). Our findings suggest that LIP deficiency renders tumor cell resistant to ER stress by preventing the induction of Ogn.

  8. Zinc as a paracrine effector in pancreatic islet cell death.

    Science.gov (United States)

    Kim, B J; Kim, Y H; Kim, S; Kim, J W; Koh, J Y; Oh, S H; Lee, M K; Kim, K W; Lee, M S

    2000-03-01

    Because of a huge amount of Zn2+ in secretory granules of pancreatic islet beta-cells, Zn2+ released in certain conditions might affect the function or survival of islet cells. We studied potential paracrine effects of endogenous Zn2+ on beta-cell death. Zn2+ induced insulinoma/islet cell death in a dose-dependent manner. Chelation of released endogenous Zn2+ by CaEDTA significantly decreased streptozotocin (STZ)-induced islet cell death in an in vitro culture system simulating in vivo circumstances but not in the conventional culture system. Zn2+ chelation in vivo by continuous CaEDTA infusion significantly decreased the incidence of diabetes after STZ administration. N-(6-methoxy-quinolyl)-para-toluene-sulfonamide staining revealed that Zn2+ was densely deposited in degenerating islet cells 24 h after STZ treatment, which was decreased by CaEDTA infusion. We show here that Zn2+ is not a passive element for insulin storage but an active participant in islet cell death in certain conditions, which in time might contribute to the development of diabetes in aged people.

  9. Love is a battlefield: programmed cell death during fertilization.

    Science.gov (United States)

    Heydlauff, Juliane; Groß-Hardt, Rita

    2014-03-01

    Plant development and growth is sustained by the constant generation of tremendous amounts of cells, which become integrated into various types of tissues and organs. What is all too often overlooked is that this thriving life also requires the targeted degeneration of selected cells, which undergo cell death according to genetically encoded programmes or environmental stimuli. The side-by-side existence of generation and demise is particularly evident in the haploid phase of the flowering plants cycle. Here, the lifespan of terminally differentiated accessory cells contrasts with that of germ cells, which by definition live on to form the next generation. In fact, with research in recent years it is becoming increasingly clear that the gametophytes of flowering plants constitute an attractive and powerful system for investigating the molecular mechanisms underlying selective cell death.

  10. Oxidative Stress and Programmed Cell Death in Yeast

    International Nuclear Information System (INIS)

    Farrugia, Gianluca; Balzan, Rena

    2012-01-01

    Yeasts, such as Saccharomyces cerevisiae, have long served as useful models for the study of oxidative stress, an event associated with cell death and severe human pathologies. This review will discuss oxidative stress in yeast, in terms of sources of reactive oxygen species (ROS), their molecular targets, and the metabolic responses elicited by cellular ROS accumulation. Responses of yeast to accumulated ROS include upregulation of antioxidants mediated by complex transcriptional changes, activation of pro-survival pathways such as mitophagy, and programmed cell death (PCD) which, apart from apoptosis, includes pathways such as autophagy and necrosis, a form of cell death long considered accidental and uncoordinated. The role of ROS in yeast aging will also be discussed.

  11. Sensory hair cell death and regeneration in fishes

    Directory of Open Access Journals (Sweden)

    Jerry D. Monroe

    2015-04-01

    Full Text Available Sensory hair cells are specialized mechanotransductive receptors required for hearing and vestibular function. Loss of hair cells in humans and other mammals is permanent and causes reduced hearing and balance. In the early 1980’s, it was shown that hair cells continue to be added to the inner ear sensory epithelia in cartilaginous and bony fishes. Soon thereafter, hair cell regeneration was documented in the chick cochlea following acoustic trauma. Since then, research using chick and other avian models has led to great insights into hair cell death and regeneration. However, with the rise of the zebrafish as a model organism for studying disease and developmental processes, there has been an increased interest in studying sensory hair cell death and regeneration in its lateral line and inner ears. Advances derived from studies in zebrafish and other fish species include understanding the effect of ototoxins on hair cells and finding otoprotectants to mitigate ototoxin damage, the role of cellular proliferation versus direct transdifferentiation during hair cell regeneration, and elucidating cellular pathways involved in the regeneration process. This review will summarize research on hair cell death and regeneration using fish models, indicate the potential strengths and weaknesses of these models, and discuss several emerging areas of future studies.

  12. Cell death in Tetrahymena thermophila: new observations on culture conditions.

    Science.gov (United States)

    Christensen, S T; Sørensen, H; Beyer, N H; Kristiansen, K; Rasmussen, L; Rasmussen, M I

    2001-01-01

    We previously suggested that the cell fate of the protozoan ciliate, Tetrahymena thermophila, effectively relates to a quorum-sensing mechanism where cell-released factors support cell survival and proliferation. The cells have to be present above a critical initial density in a chemically defined nutrient medium in order to release a sufficient level of these factors to allow a new colony to flourish. At a relatively high rate of metabolism and/or macromolecular synthesis and below this critical density, cells began to die abruptly within 30 min of inoculation, and this death took the form of an explosive disintegration lasting less than 50 milliseconds. The cells died at any location in the culture, and the frequency of cell death was always lower in well-filled vials than those with medium/air interface. Cell death was inhibited by the addition of Actinomycin D or through modifications of the culture conditions either by reducing the oxygen tension or by decreasing the temperature of the growth medium. In addition, plastic caps in well-filled vials release substances, which promote cell survival. The fate of low-density cultures is related to certain 'physical' conditions, in addition to the availability of oxygen within closed culture systems. Copyright 2001 Academic Press.

  13. Real-time monitoring of cisplatin-induced cell death.

    Directory of Open Access Journals (Sweden)

    Hamed Alborzinia

    Full Text Available Since the discovery of cisplatin more than 40 years ago and its clinical introduction in the 1970s an enormous amount of research has gone into elucidating the mechanism of action of cisplatin on tumor cells. With a novel cell biosensor chip system allowing continuous monitoring of respiration, glycolysis, and impedance we followed cisplatin treatment of different cancer cell lines in real-time. Our measurements reveal a first effect on respiration, in all cisplatin treated cell lines, followed with a significant delay by interference with glycolysis in HT-29, HCT-116, HepG2, and MCF-7 cells but not in the cisplatin-resistant cell line MDA-MB-231. Most strikingly, cell death started in all cisplatin-sensitive cell lines within 8 to 11 h of treatment, indicating a clear time frame from exposure, first response to cisplatin lesions, to cell fate decision. The time points of most significant changes were selected for more detailed analysis of cisplatin response in the breast cancer cell line MCF-7. Phosphorylation of selected signal transduction mediators connected with cellular proliferation, as well as changes in gene expression, were analyzed in samples obtained directly from sensor chips at the time points when changes in glycolysis and impedance occurred. Our online cell biosensor measurements reveal for the first time the time scale of metabolic response until onset of cell death under cisplatin treatment, which is in good agreement with models of p53-mediated cell fate decision.

  14. Trial watch: Immunogenic cell death induction by anticancer chemotherapeutics.

    Science.gov (United States)

    Garg, Abhishek D; More, Sanket; Rufo, Nicole; Mece, Odeta; Sassano, Maria Livia; Agostinis, Patrizia; Zitvogel, Laurence; Kroemer, Guido; Galluzzi, Lorenzo

    2017-01-01

    The expression "immunogenic cell death" (ICD) refers to a functionally unique form of cell death that facilitates (instead of suppressing) a T cell-dependent immune response specific for dead cell-derived antigens. ICD critically relies on the activation of adaptive responses in dying cells, culminating with the exposure or secretion of immunostimulatory molecules commonly referred to as "damage-associated molecular patterns". Only a few agents can elicit bona fide ICD, including some clinically established chemotherapeutics such as doxorubicin, epirubicin, idarubicin, mitoxantrone, bleomycin, bortezomib, cyclophosphamide and oxaliplatin. In this Trial Watch, we discuss recent progress on the development of ICD-inducing chemotherapeutic regimens, focusing on studies that evaluate clinical efficacy in conjunction with immunological biomarkers.

  15. Radiation-induced cell death by chromatin loss

    International Nuclear Information System (INIS)

    Campbell, I.R.; Warenius, H.M.

    1989-01-01

    A model is proposed which relates reproductive death of cells caused by radiation to loss of chromatin at cell division. This loss of chromatin can occur through chromosomal deletions or through the formation of asymmetrical chromosomal exchanges. It is proposed that smaller doses of radiation produce fewer chromatin breaks, which are more likely to be accurately repaired, compared with larger doses. Consequently, smaller doses of radiation are less efficient in causing cell death, leading to a shoulder on the cell survival curve. Experimental evidence supports this model, and the fit between the derived formula and experimental cell survival curves is good. The derived formula approximates to the linear-quadratic equation at low doses of radiation. (author)

  16. Lipid raft involvement in yeast cell growth and death

    Energy Technology Data Exchange (ETDEWEB)

    Mollinedo, Faustino, E-mail: fmollin@usal.es [Instituto de Biología Molecular y Celular del Cáncer, Centro de Investigación del Cáncer, Consejo Superior de Investigaciones Científicas - Universidad de Salamanca, Salamanca (Spain)

    2012-10-10

    The notion that cellular membranes contain distinct microdomains, acting as scaffolds for signal transduction processes, has gained considerable momentum. In particular, a class of such domains that is rich in sphingolipids and cholesterol, termed as lipid rafts, is thought to compartmentalize the plasma membrane, and to have important roles in survival and cell death signaling in mammalian cells. Likewise, yeast lipid rafts are membrane domains enriched in sphingolipids and ergosterol, the yeast counterpart of mammalian cholesterol. Sterol-rich membrane domains have been identified in several fungal species, including the budding yeast Saccharomyces cerevisiae, the fission yeast Schizosaccharomyces pombe as well as the pathogens Candida albicans and Cryptococcus neoformans. Yeast rafts have been mainly involved in membrane trafficking, but increasing evidence implicates rafts in a wide range of additional cellular processes. Yeast lipid rafts house biologically important proteins involved in the proper function of yeast, such as proteins that control Na{sup +}, K{sup +}, and pH homeostasis, which influence many cellular processes, including cell growth and death. Membrane raft constituents affect drug susceptibility, and drugs interacting with sterols alter raft composition and membrane integrity, leading to yeast cell death. Because of the genetic tractability of yeast, analysis of yeast rafts could be an excellent model to approach unanswered questions of mammalian raft biology, and to understand the role of lipid rafts in the regulation of cell death and survival in human cells. A better insight in raft biology might lead to envisage new raft-mediated approaches to the treatment of human diseases where regulation of cell death and survival is critical, such as cancer and neurodegenerative diseases.

  17. Lipid raft involvement in yeast cell growth and death

    International Nuclear Information System (INIS)

    Mollinedo, Faustino

    2012-01-01

    The notion that cellular membranes contain distinct microdomains, acting as scaffolds for signal transduction processes, has gained considerable momentum. In particular, a class of such domains that is rich in sphingolipids and cholesterol, termed as lipid rafts, is thought to compartmentalize the plasma membrane, and to have important roles in survival and cell death signaling in mammalian cells. Likewise, yeast lipid rafts are membrane domains enriched in sphingolipids and ergosterol, the yeast counterpart of mammalian cholesterol. Sterol-rich membrane domains have been identified in several fungal species, including the budding yeast Saccharomyces cerevisiae, the fission yeast Schizosaccharomyces pombe as well as the pathogens Candida albicans and Cryptococcus neoformans. Yeast rafts have been mainly involved in membrane trafficking, but increasing evidence implicates rafts in a wide range of additional cellular processes. Yeast lipid rafts house biologically important proteins involved in the proper function of yeast, such as proteins that control Na + , K + , and pH homeostasis, which influence many cellular processes, including cell growth and death. Membrane raft constituents affect drug susceptibility, and drugs interacting with sterols alter raft composition and membrane integrity, leading to yeast cell death. Because of the genetic tractability of yeast, analysis of yeast rafts could be an excellent model to approach unanswered questions of mammalian raft biology, and to understand the role of lipid rafts in the regulation of cell death and survival in human cells. A better insight in raft biology might lead to envisage new raft-mediated approaches to the treatment of human diseases where regulation of cell death and survival is critical, such as cancer and neurodegenerative diseases.

  18. Induction of cell death by chemotherapeutic methylating agents

    International Nuclear Information System (INIS)

    Quiros Barrantes, Steve

    2012-01-01

    The mechanism of cell death induced by O 6 MeG has been investigated and inhibition of homologous recombination as a strategy for sensitization of tumor cells against methylating agents S N 1. Dependence of the cell cycle was determined toxic responses triggered by O''6 MeG and evaluated by proliferation assays if apoptotic cells have originated exclusively from the second post-treatment cycle. Dependence of O''6 MeG was found at DSB formation. The activation of the control points of the cell cycle and induction of apoptosis is generated during the second cell cycle. Additionally, a portion of the cells has been determined that triggers apoptosis in subsequent generations in the second cell cycle. Inhibition of homologous recombination has been a reasonable strategy to increase S N 1 alkylating agent effectiveness. Evidence has been provided in NHEJ dependent inhibition of DNA-PK that not significantly sensitizes the glioblastoma cells against temozolomide [es

  19. Retinal Cell Death Caused by Sodium Iodate Involves Multiple Caspase-Dependent and Caspase-Independent Cell-Death Pathways

    Directory of Open Access Journals (Sweden)

    Jasmin Balmer

    2015-07-01

    Full Text Available Herein, we have investigated retinal cell-death pathways in response to the retina toxin sodium iodate (NaIO3 both in vivo and in vitro. C57/BL6 mice were treated with a single intravenous injection of NaIO3 (35 mg/kg. Morphological changes in the retina post NaIO3 injection in comparison to untreated controls were assessed using electron microscopy. Cell death was determined by TdT-mediated dUTP-biotin nick end labeling (TUNEL staining. The activation of caspases and calpain was measured using immunohistochemistry. Additionally, cytotoxicity and apoptosis in retinal pigment epithelial (RPE cells, primary retinal cells, and the cone photoreceptor (PRC cell line 661W were assessed in vitro after NaIO3 treatment using the ApoToxGlo™ assay. The 7-AAD/Annexin-V staining was performed and necrostatin (Nec-1 was administered to the NaIO3-treated cells to confirm the results. In vivo, degenerating RPE cells displayed a rounded shape and retracted microvilli, whereas PRCs featured apoptotic nuclei. Caspase and calpain activity was significantly upregulated in retinal sections and protein samples from NaIO3-treated animals. In vitro, NaIO3 induced necrosis in RPE cells and apoptosis in PRCs. Furthermore, Nec-1 significantly decreased NaIO3-induced RPE cell death, but had no rescue effect on treated PRCs. In summary, several different cell-death pathways are activated in retinal cells as a result of NaIO3.

  20. Hydrogen Peroxide-induced Cell Death in Arabidopsis : Transcriptional and Mutant Analysis Reveals a Role of an Oxoglutarate-dependent Dioxygenase Gene in the Cell Death Process

    NARCIS (Netherlands)

    Gechev, Tsanko S.; Minkov, Ivan N.; Hille, Jacques

    2005-01-01

    Hydrogen peroxide is a major regulator of plant programmed cell death (PCD) but little is known about the downstream genes from the H2O2-signaling network that mediate the cell death. To address this question, a novel system for studying H2O2-induced programmed cell death in Arabidopsis thaliana was

  1. Programmed cell death-1 and programmed cell death ligand-1 antibodies-induced dysthyroidism.

    Science.gov (United States)

    Jaafar, Jaafar; Fernandez, Eugenio; Alwan, Heba; Philippe, Jacques

    2018-05-01

    Monoclonal antibodies blocking the programmed cell death-1 (PD-1) or its ligand (PD-L1) are a group of immune checkpoints inhibitors (ICIs) with proven antitumor efficacy. However, their use is complicated by immune-related adverse events (irAEs), including endocrine adverse events (eAEs). We review the incidence, time to onset and resolution rate of dysthyroidism induced by PD-1/PD-L1 Ab, and the clinical, biological and radiological findings. We aim to discuss the potential mechanisms of PD-1/PD-L1 Ab-induced dysthyroidism, and to propose a management algorithm. We performed a literature search of available clinical trials regarding PD-1/PD-L1 Ab in the PubMed database. We selected all English language clinical trials that included at least 100 patients. We also present selected case series or reports, retrospective studies and reviews related to this issue. In patients treated with PD-1 Ab, hypothyroidism occurred in 2-10.1% and hyperthyroidism occurred in 0.9-7.8%. When thyroiditis was reported separately, it occurred in 0.34-2.6%. Higher rates were reported when PD-1 Ab were associated with other ICI or chemotherapy. The median time to onset of hyperthyroidism and hypothyroidism after PD-1 Ab initiation was 23-45 days and 2-3.5 months, respectively. Regarding PD-L1 Ab, hypothyroidism occurred in 0-10% and hyperthyroidism in 0.5-2% of treated patients. The average time to onset of dysthyroidism after PD-L1 Ab was variable and ranged from 1 day after treatment initiation to 31 months. Dysthyroidism occurs in up to 10% of patients treated with PD-1/PD-L1 Ab. Hypothyroidism and reversible destructive thyroiditis are the most frequent endocrine adverse events (eAE) in PD-1/PD-L1 treated patients. Immune and non-immune mechanisms are potentially involved, independently of the presence of thyroid antibodies. © 2018 The authors.

  2. Guidelines and recommendations on yeast cell death nomenclature

    NARCIS (Netherlands)

    Carmona-Gutierrez, Didac; Bauer, Maria Anna; Zimmermann, Andreas; Aguilera, Andrés; Austriaco, Nicanor; Ayscough, Kathryn; Balzan, Rena; Bar-Nun, Shoshana; Barrientos, Antonio; Belenky, Peter; Blondel, Marc; Braun, Ralf J; Breitenbach, Michael; Burhans, William C; Büttner, Sabrina; Cavalieri, Duccio; Chang, Michael; Cooper, Katrina F; Côrte-Real, Manuela; Costa, Vítor; Cullin, Christophe; Dawes, Ian; Dengjel, Jörn; Dickman, Martin B; Eisenberg, Tobias; Fahrenkrog, Birthe; Fasel, Nicolas; Fröhlich, Kai-Uwe; Gargouri, Ali; Giannattasio, Sergio; Goffrini, Paola; Gourlay, Campbell W; Grant, Chris M; Greenwood, Michael T; Guaragnella, Nicoletta; Heger, Thomas; Heinisch, Jürgen; Herker, Eva; Herrmann, Johannes M; Hofer, Sebastian; Jiménez-Ruiz, Antonio; Jungwirth, Helmut; Kainz, Katharina; Kontoyiannis, Dimitrios P; Ludovico, Paula; Manon, Stéphen; Martegani, Enzo; Mazzoni, Cristina; Megeney, Lynn A; Meisinger, Chris; Nielsen, Jens; Nyström, Thomas; Osiewacz, Heinz D; Outeiro, Tiago F; Park, Hay-Oak; Pendl, Tobias; Petranovic, Dina; Picot, Stephane; Polčic, Peter; Powers, Ted; Ramsdale, Mark; Rinnerthaler, Mark; Rockenfeller, Patrick; Ruckenstuhl, Christoph; Schaffrath, Raffael; Segovia, Maria; Severin, Fedor F; Sharon, Amir; Sigrist, Stephan J; Sommer-Ruck, Cornelia; Sousa, Maria João; Thevelein, Johan M; Thevissen, Karin; Titorenko, Vladimir; Toledano, Michel B; Tuite, Mick; Vögtle, F-Nora; Westermann, Benedikt; Winderickx, Joris; Wissing, Silke; Wölfl, Stefan; Zhang, Zhaojie J; Zhao, Richard Y; Zhou, Bing; Galluzzi, Lorenzo; Kroemer, Guido; Madeo, Frank

    2018-01-01

    Elucidating the biology of yeast in its full complexity has major implications for science, medicine and industry. One of the most critical processes determining yeast life and physiology is cel-lular demise. However, the investigation of yeast cell death is a relatively young field, and a widely

  3. Mitochondrial and Cell Death Mechanisms in Neurodegenerative Diseases

    Directory of Open Access Journals (Sweden)

    Lee J. Martin

    2010-03-01

    Full Text Available Alzheimer’s disease (AD, Parkinson’s disease (PD and amyotrophic lateral sclerosis (ALS are the most common human adult-onset neurodegenerative diseases. They are characterized by prominent age-related neurodegeneration in selectively vulnerable neural systems. Some forms of AD, PD, and ALS are inherited, and genes causing these diseases have been identified. Nevertheless, the mechanisms of the neuronal cell death are unresolved. Morphological, biochemical, genetic, as well as cell and animal model studies reveal that mitochondria could have roles in this neurodegeneration. The functions and properties of mitochondria might render subsets of selectively vulnerable neurons intrinsically susceptible to cellular aging and stress and overlying genetic variations, triggering neurodegeneration according to a cell death matrix theory. In AD, alterations in enzymes involved in oxidative phosphorylation, oxidative damage, and mitochondrial binding of Aβ and amyloid precursor protein have been reported. In PD, mutations in putative mitochondrial proteins have been identified and mitochondrial DNA mutations have been found in neurons in the substantia nigra. In ALS, changes occur in mitochondrial respiratory chain enzymes and mitochondrial cell death proteins. Transgenic mouse models of human neurodegenerative disease are beginning to reveal possible principles governing the biology of selective neuronal vulnerability that implicate mitochondria and the mitochondrial permeability transition pore. This review summarizes how mitochondrial pathobiology might contribute to neuronal death in AD, PD, and ALS and could serve as a target for drug therapy.

  4. What history tells us XXI. Apoptosis and programmed cell death

    Indian Academy of Sciences (India)

    2010-04-30

    Apr 30, 2010 ... Home; Journals; Journal of Biosciences; Volume 35; Issue 2. What history tells us XXI. Apoptosis and programmed cell death: when biological categories are blurred. Michel Morange. Series Volume 35 Issue 2 June 2010 pp 177-181 ...

  5. Palladium induced oxidative stress and cell death in normal ...

    African Journals Online (AJOL)

    Our findings clearly indicate that Pd induces reactive oxygen species (ROS) formation and oxidative stress, mitochondrial and lysosomal injury and finally cell death. These effects are reversed by antioxidants and ROS scavengers, mitochondrial permeability transmission [1] pore sealing agent, ATP progenitor, and ...

  6. Networked T cell death following macrophage infection by Mycobacterium tuberculosis.

    Directory of Open Access Journals (Sweden)

    Stephen H-F Macdonald

    Full Text Available BACKGROUND: Depletion of T cells following infection by Mycobacterium tuberculosis (Mtb impairs disease resolution, and interferes with clinical test performance that relies on cell-mediated immunity. A number of mechanisms contribute to this T cell suppression, such as activation-induced death and trafficking of T cells out of the peripheral circulation and into the diseased lungs. The extent to which Mtb infection of human macrophages affects T cell viability however, is not well characterised. METHODOLOGY/PRINCIPAL FINDINGS: We found that lymphopenia (<1.5 × 10(9 cells/l was prevalent among culture-positive tuberculosis patients, and lymphocyte counts significantly improved post-therapy. We previously reported that Mtb-infected human macrophages resulted in death of infected and uninfected bystander macrophages. In the current study, we sought to examine the influence of infected human alveolar macrophages on T cells. We infected primary human alveolar macrophages (the primary host cell for Mtb or PMA-differentiated THP-1 cells with Mtb H37Ra, then prepared cell-free supernatants. The supernatants of Mtb-infected macrophages caused dose-dependent, caspase-dependent, T cell apoptosis. This toxic effect of infected macrophage secreted factors did not require TNF-α or Fas. The supernatant cytotoxic signal(s were heat-labile and greater than 50 kDa in molecular size. Although ESAT-6 was toxic to T cells, other Mtb-secreted factors tested did not influence T cell viability; nor did macrophage-free Mtb bacilli or broth from Mtb cultures. Furthermore, supernatants from Mycobacterium bovis Bacille de Calmette et Guerin (BCG- infected macrophages also elicited T cell death suggesting that ESAT-6 itself, although cytotoxic, was not the principal mediator of T cell death in our system. CONCLUSIONS: Mtb-Infected macrophages secrete heat-labile factors that are toxic to T cells, and may contribute to the immunosuppression seen in tuberculosis as well as

  7. Delineating the cell death mechanisms associated with skin electroporation.

    Science.gov (United States)

    Schultheis, Katherine; Smith, Trevor R F; Kiosses, William B; Kraynyak, Kimberly A; Wong, Amelia; Oh, Janet; Broderick, Kate Elizabeth

    2018-06-28

    The immune responses elicited following delivery of DNA vaccines to the skin has previously been shown to be significantly enhanced by the addition of electroporation (EP) to the treatment protocol. Principally, EP increases the transfection of pDNA into the resident skin cells. In addition to increasing the levels of in vivo transfection, the physical insult induced by EP is associated with activation of innate pathways which are believed to mediate an adjuvant effect, further enhancing DNA vaccine responses. Here, we have investigated the possible mechanisms associated with this adjuvant effect, primarily focusing on the cell death pathways associated with the skin EP procedure independent of pDNA delivery. Using the minimally invasive CELLECTRA®-3P intradermal electroporation device that penetrates the epidermal and dermal layers of the skin, we have investigated apoptotic and necrotic cell death in relation to the vicinity of the electrode needles and electric field generated. Employing the well-established TUNEL assay, we detected apoptosis beginning as early as one hour after EP and peaking at the 4 hour time point. The majority of the apoptotic events were detected in the epidermal region directly adjacent to the electrode needle. Using a novel propidium iodide in vivo necrotic cell death assay, we detected necrotic events concentrated in the epidermal region adjacent to the electrode. Furthermore, we detected up-regulation of calreticulin expression on skin cells after EP, thus labeling these cells for uptake by dendritic cells and macrophages. These results allow us to delineate the cell death mechanisms occurring in the skin following intradermal EP independently of pDNA delivery. We believe these events contribute to the adjuvant effect observed following electroporation at the skin treatment site.

  8. Delayed innocent bystander cell death following hypoxia in Caenorhabditis elegans.

    Science.gov (United States)

    Sun, C-L; Kim, E; Crowder, C M

    2014-04-01

    After hypoxia, cells may die immediately or have a protracted course, living or dying depending on an incompletely understood set of cell autonomous and nonautonomous factors. In stroke, for example, some neurons are thought to die from direct hypoxic injury by cell autonomous primary mechanisms, whereas other so called innocent bystander neurons die from factors released from the primarily injured cells. A major limitation in identifying these factors is the inability of current in vivo models to selectively target a set of cells for hypoxic injury so that the primarily injured cells and the innocent bystanders are clearly delineated. In order to develop such a model, we generated transgenic Caenorhabditis elegans strains where 2-3% of somatic cells were made selectively sensitive to hypoxia. This was accomplished by cell type-specific wild-type rescue in either pharyngeal myocytes or GABAergic neurons of a hypoxia resistance-producing translation factor mutation. Surprisingly, hypoxic targeting of these relatively small subsets of non-essential cells produced widespread innocent bystander cell injury, behavioral dysfunction and eventual organismal death. The hypoxic injury phenotypes of the myocyte or neuron sensitized strains were virtually identical. Using this model, we show that the C. elegans insulin receptor/FOXO transcription factor pathway improves survival when activated only after hypoxic injury and blocks innocent bystander death.

  9. JS-K, a nitric oxide-releasing prodrug, induces breast cancer cell death while sparing normal mammary epithelial cells.

    Science.gov (United States)

    McMurtry, Vanity; Saavedra, Joseph E; Nieves-Alicea, René; Simeone, Ann-Marie; Keefer, Larry K; Tari, Ana M

    2011-04-01

    Targeted therapy with reduced side effects is a major goal in cancer research. We investigated the effects of JS-K, a nitric oxide (NO) prodrug designed to release high levels of NO when suitably activated, on human breast cancer cell lines, on non-transformed human MCF-10A mammary cells, and on normal human mammary epithelial cells (HMECs). Cell viability assay, flow cytometry, electron microscopy, and Western blot analysis were used to study the effects of JS-K on breast cancer and on mammary epithelial cells. After a 3-day incubation, the IC50s of JS-K against the breast cancer cells ranged from 0.8 to 3 µM. However, JS-K decreased the viability of the MCF-10A cells by only 20% at 10-µM concentration, and HMECs were unaffected by 10 µM JS-K. Flow cytometry indicated that JS-K increased the percentages of breast cancer cells under-going apoptosis. Interestingly, flow cytometry indicated that JS-K increased acidic vesicle organelle formation in breast cancer cells, suggesting that JS-K induced autophagy in breast cancer cells. Electron microscopy confirmed that JS-K-treated breast cancer cells underwent autophagic cell death. Western blot analysis showed that JS-K induced the expression of microtubule light chain 3-II, another autophagy marker, in breast cancer cells. However, JS-K did not induce apoptosis or autophagy in normal human mammary epithelial cells. These data indicate that JS-K selectively induces programmed cell death in breast cancer cells while sparing normal mammary epithelial cells under the same conditions. The selective anti-tumor activity of JS-K warrants its further investigation in breast tumors.

  10. Heterogeneity reduces sensitivity of cell death for TNF-Stimuli

    Directory of Open Access Journals (Sweden)

    Schliemann Monica

    2011-12-01

    Full Text Available Abstract Background Apoptosis is a form of programmed cell death essential for the maintenance of homeostasis and the removal of potentially damaged cells in multicellular organisms. By binding its cognate membrane receptor, TNF receptor type 1 (TNF-R1, the proinflammatory cytokine Tumor Necrosis Factor (TNF activates pro-apoptotic signaling via caspase activation, but at the same time also stimulates nuclear factor κB (NF-κB-mediated survival pathways. Differential dose-response relationships of these two major TNF signaling pathways have been described experimentally and using mathematical modeling. However, the quantitative analysis of the complex interplay between pro- and anti-apoptotic signaling pathways is an open question as it is challenging for several reasons: the overall signaling network is complex, various time scales are present, and cells respond quantitatively and qualitatively in a heterogeneous manner. Results This study analyzes the complex interplay of the crosstalk of TNF-R1 induced pro- and anti-apoptotic signaling pathways based on an experimentally validated mathematical model. The mathematical model describes the temporal responses on both the single cell level as well as the level of a heterogeneous cell population, as observed in the respective quantitative experiments using TNF-R1 stimuli of different strengths and durations. Global sensitivity of the heterogeneous population was quantified by measuring the average gradient of time of death versus each population parameter. This global sensitivity analysis uncovers the concentrations of Caspase-8 and Caspase-3, and their respective inhibitors BAR and XIAP, as key elements for deciding the cell's fate. A simulated knockout of the NF-κB-mediated anti-apoptotic signaling reveals the importance of this pathway for delaying the time of death, reducing the death rate in the case of pulse stimulation and significantly increasing cell-to-cell variability. Conclusions Cell

  11. Rational development of a cytotoxic peptide to trigger cell death.

    Science.gov (United States)

    Boohaker, Rebecca J; Zhang, Ge; Lee, Michael W; Nemec, Kathleen N; Santra, Santimukul; Perez, J Manuel; Khaled, Annette R

    2012-07-02

    Defects in the apoptotic machinery can contribute to tumor formation and resistance to treatment, creating a need to identify new agents that kill cancer cells by alternative mechanisms. To this end, we examined the cytotoxic properties of a novel peptide, CT20p, derived from the C-terminal, alpha-9 helix of Bax, an amphipathic domain with putative membrane binding properties. Like many antimicrobial peptides, CT20p contains clusters of hydrophobic and cationic residues that could enable the peptide to associate with lipid membranes. CT20p caused the release of calcein from mitochondrial-like lipid vesicles without disrupting vesicle integrity and, when expressed as a fusion protein in cells, localized to mitochondria. The amphipathic nature of CT20p allowed it to be encapsulated in polymeric nanoparticles (NPs) that have the capacity to harbor targeting molecules, dyes or drugs. The resulting CT20p-NPs proved an effective killer, in vitro, of colon and breast cancer cells, and in vivo, using a murine breast cancer tumor model. By introducing CT20p to Bax deficient cells, we demonstrated that the peptide's lethal activity was independent of endogenous Bax. CT20p also caused an increase in the mitochondrial membrane potential that was followed by plasma membrane rupture and cell death, without the characteristic membrane asymmetry associated with apoptosis. We determined that cell death triggered by the CT20p-NPs was minimally dependent on effector caspases and resistant to Bcl-2 overexpression, suggesting that it acts independently of the intrinsic apoptotic death pathway. Furthermore, use of CT20p with the apoptosis-inducing drug, cisplatin, resulted in additive toxicity. These results reveal the novel features of CT20p that allow nanoparticle-mediated delivery to tumors and the potential application in combination therapies to activate multiple death pathways in cancer cells.

  12. Radiation-induced cell death in embryogenic cells of coniferous plants

    International Nuclear Information System (INIS)

    Watanabe, Yoshito; Homma-Takeda, Shino; Yukawa, Masae; Nishimura, Yoshikazu; Sasamoto, Hamako; Takahagi, Masahiko

    2004-01-01

    Reproductive processes are particularly radiosensitive in plant development, which was clearly illustrated in reduction of seed formation in native coniferous plants around Chernobyl after the nuclear accident. For the purpose to investigate the effects of ionizing radiation on embryonic formation in coniferous plants, we used an embryo-derived embryogenic cell culture of a Japanese native coniferous plant, Japanese cedar (Cryplomeria japonica). The embryogenic cells were so radiosensitive that most of the cells died by X-ray irradiation of 5 Gy. This indicated that the embryogenic cells are as radiosensitive as some mammalian cells including lymphocytes. We considered that this type of radiosensitive cell death in the embryogenic cells should be responsible for reproductive damages of coniferous plants by low dose of ionizing radiation. The cell death of the embryogenic cells was characteristic of nuclear DNA fragmentation, which is typically observed in radiation-induced programmed cell death, i.e. apoptosis, in mammalian cells. On the other hand, cell death with nuclear DNA fragmentation did not develop by X-ray irradiation in vegetative cells including meristematic cells of Japanese cedar. This suggests that an apoptosis-like programmed cell death should develop cell-specifically in embryogenic cells by ionizing radiation. The abortion of embryogenic cells may work to prevent transmission of radiation-induced genetic damages to the descendants. (author)

  13. Blockade of maitotoxin-induced oncotic cell death reveals zeiosis

    Directory of Open Access Journals (Sweden)

    Schilling William P

    2002-01-01

    Full Text Available Abstract Background Maitotoxin (MTX initiates cell death by sequentially activating 1 Ca2+ influx via non-selective cation channels, 2 uptake of vital dyes via formation of large pores, and 3 release of lactate dehydrogenase, an indication of cell lysis. MTX also causes formation of membrane blebs, which dramatically dilate during the cytolysis phase. To determine the role of phospholipase C (PLC in the cell death cascade, U73122, a specific inhibitor of PLC, and U73343, an inactive analog, were examined on MTX-induced responses in bovine aortic endothelial cells. Results Addition of either U73122 or U73343, prior to MTX, produced a concentration-dependent inhibition of the cell death cascade (IC50 ≈ 1.9 and 0.66 μM, respectively suggesting that the effect of these agents was independent of PLC. Addition of U73343 shortly after MTX, prevented or attenuated the effects of the toxin, but addition at later times had little or no effect. Time-lapse videomicroscopy showed that U73343 dramatically altered the blebbing profile of MTX-treated cells. Specifically, U73343 blocked bleb dilation and converted the initial blebbing event into "zeiosis", a type of membrane blebbing commonly associated with apoptosis. Cells challenged with MTX and rescued by subsequent addition of U73343, showed enhanced caspase-3 activity 48 hr after the initial insult, consistent with activation of the apoptotic program. Conclusions Within minutes of MTX addition, endothelial cells die by oncosis. Rescue by addition of U73343 shortly after MTX showed that a small percentage of cells are destined to die by oncosis, but that a larger percentage survive; cells that survive the initial insult exhibit zeiosis and may ultimately die by apoptotic mechanisms.

  14. Apoptosis in fish: environmental factors and programmed cell death.

    Science.gov (United States)

    AnvariFar, Hossein; Amirkolaie, Abdolsamad Keramat; Miandare, Hamed Kolangi; Ouraji, Hossein; Jalali, M Ali; Üçüncü, Sema İşisağ

    2017-06-01

    Apoptosis, a form of programmed cell death, is a critical component in maintaining homeostasis and growth in all tissues and plays a significant role in immunity and cytotoxicity. In contrast to necrosis or traumatic cell death, apoptosis is a well-controlled and vital process characterized mainly by cytoplasmic shrinkage, chromatin condensation, DNA fragmentation, membrane blebbing and apoptotic bodies. Our understanding of apoptosis is partly based on observations in invertebrates but mainly in mammals. Despite the great advantages of fish models in studying vertebrate development and diseases and the tremendous interest observed in recent years, reports on apoptosis in fish are still limited. Although apoptotic machinery is well conserved between aquatic and terrestrial organisms throughout the history of evolution, some differences exist in key components of apoptotic pathways. Core parts of apoptotic machinery in fish are virtually expressed as equivalent to the mammalian models. Some differences are, however, evident, such as the extrinsic and intrinsic pathways of apoptosis including lack of a C-terminal region in the Fas-associated protein with a death domain in fish. Aquatic species inhabit a complex and highly fluctuating environment, making these species good examples to reveal features of apoptosis that may not be easily investigated in mammals. Therefore, in order to gain a wider view on programmed cell death in fish, interactions between the main environmental factors, chemicals and apoptosis are discussed in this review. It is indicated that apoptosis can be induced in fish by exposure to environmental stressors during different stages of the fish life cycle.

  15. Interphase death of dividing cells. Kinetics of death of cultured Chinese hamster fibroblasts after irradiation with various doses

    International Nuclear Information System (INIS)

    Kublik, L.N.; Veksler, A.M.; Ehjdus, L.Kh.

    1989-01-01

    In studying the kinetics of interphase death (ID) of cultured Chinese hamster cells after irradiation with doses of 100 to 800 Gy the authors showed an increase in the ID rate with increasing radiation dose; the presence of serum in the medium both during and after irradiation prevents the cell death

  16. Tumor necrosis factor (TNF) biology and cell death.

    Science.gov (United States)

    Bertazza, Loris; Mocellin, Simone

    2008-01-01

    Tumor necrosis factor (TNF) was the first cytokine to be used in humans for cancer therapy. However, its role in the treatment of cancer patients is debated. Most uncertainties in this field stem from the knowledge that the pathways directly activated or indirectly affected upon TNF engagement with its receptors can ultimately lead to very different outcomes in terms of cell survival. In this article, we summarize the fundamental molecular biology aspects of this cytokine. Such a basis is a prerequisite to critically approach the sometimes conflicting preclinical and clinical findings regarding the relationship between TNF, tumor biology and anticancer therapy. Although the last decade has witnessed remarkable advances in this field, we still do not know in detail how cells choose between life and death after TNF stimulation. Understanding this mechanism will not only shed new light on the physiological significance of TNF-driven programmed cell death but also help investigators maximize the anticancer potential of this cytokine.

  17. Trial Watch: Immunogenic cell death inducers for anticancer chemotherapy.

    Science.gov (United States)

    Pol, Jonathan; Vacchelli, Erika; Aranda, Fernando; Castoldi, Francesca; Eggermont, Alexander; Cremer, Isabelle; Sautès-Fridman, Catherine; Fucikova, Jitka; Galon, Jérôme; Spisek, Radek; Tartour, Eric; Zitvogel, Laurence; Kroemer, Guido; Galluzzi, Lorenzo

    2015-04-01

    The term "immunogenic cell death" (ICD) is now employed to indicate a functionally peculiar form of apoptosis that is sufficient for immunocompetent hosts to mount an adaptive immune response against dead cell-associated antigens. Several drugs have been ascribed with the ability to provoke ICD when employed as standalone therapeutic interventions. These include various chemotherapeutics routinely employed in the clinic (e.g., doxorubicin, epirubicin, idarubicin, mitoxantrone, bleomycin, bortezomib, cyclophosphamide and oxaliplatin) as well as some anticancer agents that are still under preclinical or clinical development (e.g., some microtubular inhibitors of the epothilone family). In addition, a few drugs are able to convert otherwise non-immunogenic instances of cell death into bona fide ICD, and may therefore be employed as chemotherapeutic adjuvants within combinatorial regimens. This is the case of cardiac glycosides, like digoxin and digitoxin, and zoledronic acid. Here, we discuss recent developments on anticancer chemotherapy based on ICD inducers.

  18. Megasporogenesis and programmed cell death in Tillandsia (Bromeliaceae).

    Science.gov (United States)

    Papini, Alessio; Mosti, Stefano; Milocani, Eva; Tani, Gabriele; Di Falco, Pietro; Brighigna, Luigi

    2011-10-01

    The degeneration of three of four meiotic products is a very common process in the female gender of oogamous eukaryotes. In Tillandsia (and many other angiosperms), the surviving megaspore has a callose-free wall in chalazal position while the other three megaspores are completely embedded in callose. Therefore, nutrients and signals can reach more easily the functional megaspore from the nucellus through the chalazal pole with respect to the other megaspores. The abortion of three of four megaspores was already recognized as the result of a programmed cell death (PCD) process. We investigated the process to understand the modality of this specific type of PCD and its relationship to the asymmetric callose deposition around the tetrad. The decision on which of the four megaspores will be the supernumerary megaspores in angiosperms, and hence destined to undergo programmed cell death, appears to be linked to the callose layer deposition around the tetrad. During supernumerary megaspores degeneration, events leading to the deletion of the cells do not appear to belong to a single type of cell death. The first morphological signs are typical of autophagy, including the formation of autophagosomes. The TUNEL positivity and a change in morphology of mitochondria and chloroplasts indicate the passage to an apoptotic-like PCD phase, while the cellular remnants undergo a final process resembling at least partially (ER swelling) necrotic morphological syndromes, eventually leading to a mainly lipidic cell corpse still separated from the functional megaspore by a callose layer.

  19. MK-2206, an AKT Inhibitor, Promotes Caspase-Independent Cell Death and Inhibits Leiomyoma Growth

    Science.gov (United States)

    Sefton, Elizabeth C.; Qiang, Wenan; Serna, Vanida; Kurita, Takeshi; Wei, Jian-Jun; Chakravarti, Debabrata

    2013-01-01

    Uterine leiomyomas (ULs), benign tumors of the myometrium, are the number one indication for hysterectomies in the United States due to a lack of an effective alternative therapy. ULs show activation of the pro-survival AKT pathway compared with normal myometrium; however, substantial data directly linking AKT to UL cell survival are lacking. We hypothesized that AKT promotes UL cell survival and that it is a viable target for inhibiting UL growth. We used the investigational AKT inhibitor MK-2206, currently in phase II trials, on cultured primary human UL and myometrial cells, immortalized leiomyoma cells, and in leiomyoma grafts grown under the kidney capsule in mice. MK-2206 inhibited AKT and PRAS40 phosphorylation but did not regulate serum- and glucocorticoid-induced kinase and ERK1/2, demonstrating its specificity for AKT. MK-2206 reduced UL cell viability and decreased UL tumor volumes. UL cells exhibited disruption of mitochondrial structures and underwent cell death that was independent of caspases. Additionally, mammalian target of rapamycin and p70S6K phosphorylation were reduced, indicating that mammalian target of rapamycin complex 1 signaling was compromised by AKT inhibition in UL cells. MK-2206 also induced autophagy in UL cells. Pretreatment of primary UL cells with 3-methyladenine enhanced MK-2206-mediated UL cell death, whereas knockdown of ATG5 and/or ATG7 did not significantly influence UL cell viability in the presence of MK-2206. Our data provide molecular evidence for the involvement of AKT in UL cell survival and suggest that AKT inhibition by MK-2206 may be a viable option to consider for the treatment of ULs. PMID:24002033

  20. Canthin-6-one induces cell death, cell cycle arrest and differentiation in human myeloid leukemia cells.

    Science.gov (United States)

    Vieira Torquato, Heron F; Ribeiro-Filho, Antonio C; Buri, Marcus V; Araújo Júnior, Roberto T; Pimenta, Renata; de Oliveira, José Salvador R; Filho, Valdir C; Macho, Antonio; Paredes-Gamero, Edgar J; de Oliveira Martins, Domingos T

    2017-04-01

    Canthin-6-one is a natural product isolated from various plant genera and from fungi with potential antitumor activity. In the present study, we evaluate the antitumor effects of canthin-6-one in human myeloid leukemia lineages. Kasumi-1 lineage was used as a model for acute myeloid leukemia. Cells were treated with canthin-6-one and cell death, cell cycle and differentiation were evaluated in both total cells (Lin + ) and leukemia stem cell population (CD34 + CD38 - Lin -/low ). Among the human lineages tested, Kasumi-1 was the most sensitive to canthin-6-one. Canthin-6-one induced cell death with apoptotic (caspase activation, decrease of mitochondrial potential) and necrotic (lysosomal permeabilization, double labeling of annexin V/propidium iodide) characteristics. Moreover, canthin-6-one induced cell cycle arrest at G 0 /G 1 (7μM) and G 2 (45μM) evidenced by DNA content, BrdU incorporation and cyclin B1/histone 3 quantification. Canthin-6-one also promoted differentiation of Kasumi-1, evidenced by an increase in the expression of myeloid markers (CD11b and CD15) and the transcription factor PU.1. Furthermore, a reduction of the leukemic stem cell population and clonogenic capability of stem cells were observed. These results show that canthin-6-one can affect Kasumi-1 cells by promoting cell death, cell cycle arrest and cell differentiation depending on concentration used. Canthin-6-one presents an interesting cytotoxic activity against leukemic cells and represents a promising scaffold for the development of molecules for anti-leukemic applications, especially by its anti-leukemic stem cell activity. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Sigma-2 ligands and PARP inhibitors synergistically trigger cell death in breast cancer cells

    International Nuclear Information System (INIS)

    McDonald, Elizabeth S.; Mankoff, Julia; Makvandi, Mehran; Chu, Wenhua; Chu, Yunxiang; Mach, Robert H.; Zeng, Chenbo

    2017-01-01

    The sigma-2 receptor is overexpressed in proliferating cells compared to quiescent cells and has been used as a target for imaging solid tumors by positron emission tomography. Recent work has suggested that the sigma-2 receptor may also be an effective therapeutic target for cancer therapy. Poly (ADP-ribose) polymerase (PARP) is a family of enzymes involved in DNA damage response. In this study, we looked for potential synergy of cytotoxicity between PARP inhibitors and sigma-2 receptor ligands in breast cancer cell lines. We showed that the PARP inhibitor, YUN3-6, sensitized mouse breast cancer cell line, EMT6, to sigma-2 receptor ligand (SV119, WC-26, and RHM-138) induced cell death determined by cell viability assay and colony forming assay. The PARP inhibitor, olaparib, sensitized tumor cells to a different sigma-2 receptor ligand SW43-induced apoptosis and cell death in human triple negative cell line, MDA-MB-231. Olaparib inhibited PARP activity and cell proliferation, and arrested cells in G2/M phase of the cell cycle in MDA-MB-231 cells. Subsequently cells became sensitized to SW43 induced cell death. In conclusion, the combination of sigma-2 receptor ligands and PARP inhibitors appears to hold promise for synergistically triggering cell death in certain types of breast cancer cells and merits further investigation. - Highlights: • PARPi, YUN3-6 and olaparib, and σ2 ligands, SV119 and SW43, were evaluated. • Mouse and human breast cancer cells, EMT6 and MDA-MB-231 respectively, were used. • YUN3-6 and SV119 synergistically triggered cell death in EMT6 cells. • Olaparib and SW43 additively triggered cell death in MDA-MB-231 cells. • Olaparib arrested cells in G2/M in MDA-MB-231 cells.

  2. Apoptotic induction of skin cancer cell death by plant extracts.

    Science.gov (United States)

    Thuncharoen, Walairat; Chulasiri, Malin; Nilwarangkoon, Sirinun; Nakamura, Yukio; Watanapokasin, Ramida

    2013-01-01

    The aim of the present study was to investigate the effects of plant extracts on cancer apoptotic induction. Human epidermoid carcinoma A431 cell line, obtained from the American Type Culture Collection (ATCC, Manassas, VA), was maintained in Dulbecco's Modified Eagle Medium (DMEM) supplemented with 10% fetal bovine serum (FBS) at 37 degrees C, 5% carbon dioxide (CO2). Plant extract solutions were obtained from S & J international enterprises public company limited. These plant extracts include 50% hydroglycol extracts from Etlingera elatior (Jack) R.M.Smith (torch ginger; EE), Rosa damascene (damask rose; DR) and Rafflesia kerrii Meijer (bua phut; RM). The cell viability, time and dose dependency were determined by MTT (3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) assay. A431 cells were treated with the plant extracts and stained with Hoechst 33342 fluorescent staining dye. Cell viability was demonstrated by the inhibitory concentration 50% (IC50). The anti-proliferative effects were shown to be dependent on time and dose. Typical characteristics of apoptosis which are cell morphological changes and chromatin condensation were clearly observed. The plant extracts was shown to be effective for anti-proliferation and induction of apoptosis cell death in skin cancer cells. Therefore, mechanisms underlying the cell death and its potential use for treatment of skin cancer will be further studied.

  3. Bee Venom Protects against Rotenone-Induced Cell Death in NSC34 Motor Neuron Cells

    Directory of Open Access Journals (Sweden)

    So Young Jung

    2015-09-01

    Full Text Available Rotenone, an inhibitor of mitochondrial complex I of the mitochondrial respiratory chain, is known to elevate mitochondrial reactive oxygen species and induce apoptosis via activation of the caspase-3 pathway. Bee venom (BV extracted from honey bees has been widely used in oriental medicine and contains melittin, apamin, adolapin, mast cell-degranulating peptide, and phospholipase A2. In this study, we tested the effects of BV on neuronal cell death by examining rotenone-induced mitochondrial dysfunction. NSC34 motor neuron cells were pretreated with 2.5 μg/mL BV and stimulated with 10 μM rotenone to induce cell toxicity. We assessed cell death by Western blotting using specific antibodies, such as phospho-ERK1/2, phospho-JNK, and cleaved capase-3 and performed an MTT assay for evaluation of cell death and mitochondria staining. Pretreatment with 2.5 μg/mL BV had a neuroprotective effect against 10 μM rotenone-induced cell death in NSC34 motor neuron cells. Pre-treatment with BV significantly enhanced cell viability and ameliorated mitochondrial impairment in rotenone-treated cellular model. Moreover, BV treatment inhibited the activation of JNK signaling and cleaved caspase-3 related to cell death and increased ERK phosphorylation involved in cell survival in rotenone-treated NSC34 motor neuron cells. Taken together, we suggest that BV treatment can be useful for protection of neurons against oxidative stress or neurotoxin-induced cell death.

  4. Activation of intracellular angiotensin AT2 receptors induces rapid cell death in human uterine leiomyosarcoma cells

    DEFF Research Database (Denmark)

    Zhao, Yi; Lützen, Ulf; Fritsch, Jürgen

    2015-01-01

    The presence of AT2 receptors in mitochondria and their role in NO generation and cell aging were recently demonstrated in various human and mouse non-tumour cells. We investigated the intracellular distribution of AT2 receptors including their presence in mitochondria and the role in the induction...... agonist, Compound 21 (C21) penetrates the cell membrane of quiescent SK-UT-1 cells, activates intracellular AT2 receptors and induces rapid cell death; approximately 70% of cells died within 24 h. The cells, which escaped from the cell death, displayed activation of the mitochondrial apoptotic pathway, i...

  5. Lysosomal cysteine peptidases - Molecules signaling tumor cell death and survival.

    Science.gov (United States)

    Pišlar, Anja; Perišić Nanut, Milica; Kos, Janko

    2015-12-01

    Lysosomal cysteine peptidases - cysteine cathepsins - are general intracellular protein-degrading enzymes that control also a variety of specific physiological processes. They can trigger irreversible events leading to signal transduction and activation of signaling pathways, resulting in cell survival and proliferation or cell death. In cancer cells, lysosomal cysteine peptidases are involved in multiple processes during malignant progression. Their translocation from the endosomal/lysosomal pathway to nucleus, cytoplasm, plasma membrane and extracellular space enables the activation and remodeling of a variety of tumor promoting proteins. Thus, lysosomal cysteine peptidases interfere with cytokine/chemokine signaling, regulate cell adhesion and migration and endocytosis, are involved in the antitumor immune response and apoptosis, and promote cell invasion, angiogenesis and metastasis. Further, lysosomal cysteine peptidases modify growth factors and receptors involved in tyrosine kinase dependent pathways such as MAPK, Akt and JNK, thus representing key signaling tools for the activation of tumor cell growth and proliferation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Cell death induced by gamma irradiation of developing skeletal muscle

    International Nuclear Information System (INIS)

    Olive, M.; Blanco, R.; Rivera, R.; Cinos, C.; Ferrer, I.

    1995-01-01

    Newborn Sprague-Dawley rats were exposed to a single dose of 2 Gy gamma rays and killed from 6 h to 5 d later. Increased numbers of dying cells, characterised by their extreme chromatin condensation and often nuclear fragmentation were seen in skeletal muscle 6 h after irradiation. Dying cells decreased to nearly normal values 48 h later. In situ labelling of nuclear DNA fragmentation identified individual cells bearing fragmented DNA. The effects of gamma rays were suppressed following cycloheximide i.p. at a dose of 1 μg/g body weight given at the time of irradiation. Taken together, the present morphological and pharmacological results suggest that gamma ray induced cell death in skeletal muscle is apoptotic, and that the process is associated with protein synthesis. Finally, proliferating cell nuclear antigen-immunoreactive cells, which were abundant in control rats, decreased in number 48 h after irradiation. However, a marked increase significantly above normal age values was observed at the 5th day, thus suggesting that regeneration occurs following irradiation-induced cell death in developing muscle. (author)

  7. Cytokines in immunogenic cell death: Applications for cancer immunotherapy.

    Science.gov (United States)

    Showalter, Anne; Limaye, Arati; Oyer, Jeremiah L; Igarashi, Robert; Kittipatarin, Christina; Copik, Alicja J; Khaled, Annette R

    2017-09-01

    Despite advances in treatments like chemotherapy and radiotherapy, metastatic cancer remains a leading cause of death for cancer patients. While many chemotherapeutic agents can efficiently eliminate cancer cells, long-term protection against cancer is not achieved and many patients experience cancer recurrence. Mobilizing and stimulating the immune system against tumor cells is one of the most effective ways to protect against cancers that recur and/or metastasize. Activated tumor specific cytotoxic T lymphocytes (CTLs) can seek out and destroy metastatic tumor cells and reduce tumor lesions. Natural Killer (NK) cells are a front-line defense against drug-resistant tumors and can provide tumoricidal activity to enhance tumor immune surveillance. Cytokines like IFN-γ or TNF play a crucial role in creating an immunogenic microenvironment and therefore are key players in the fight against metastatic cancer. To this end, a group of anthracyclines or treatments like photodynamic therapy (PDT) exert their effects on cancer cells in a manner that activates the immune system. This process, known as immunogenic cell death (ICD), is characterized by the release of membrane-bound and soluble factors that boost the function of immune cells. This review will explore different types of ICD inducers, some in clinical trials, to demonstrate that optimizing the cytokine response brought about by treatments with ICD-inducing agents is central to promoting anti-cancer immunity that provides long-lasting protection against disease recurrence and metastasis. Copyright © 2017. Published by Elsevier Ltd.

  8. Quality of Life and Psychopathology in Adults Who Underwent Hematopoietic Stem Cell Transplantation (HSCT in Childhood: A Qualitative and Quantitative Analysis

    Directory of Open Access Journals (Sweden)

    Francesco Sinatora

    2017-08-01

    Full Text Available Background: Patients who undergo pediatric Hematopoietic Stem Cell Transplantation (HSCT may experience long-term psychological sequelae and poor Quality of Life (QoL in adulthood. This study aimed to investigate subjective illness experience, QoL, and psychopathology in young adults who have survived pediatric HSCT.Method: The study involved patients treated with HSCT in the Hematology-Oncology Department between 1984 and 2007. Psychopathology and QoL were investigated using the SCL-90-R and SF-36. Socio-demographic and medical information was also collected. Finally, participants were asked to write a brief composition about their experiences of illness and care. Qualitative analysis of the texts was performed using T-LAB, an instrument for text analysis that allows the user to highlight the occurrences and co-occurrences of lemma. Quantitative analyses were performed using non-parametric tests (Spearman correlations, Kruskal-Wallis and Mann-Whitney tests.Results: Twenty-one patients (9 males participated in the study. No significant distress was found on the SCL-90 Global Severity Index, but it was found on specific scales. On the SF-36, lower scores were reported on scales referring to bodily pain, general health, and physical and social functioning. All the measures were significantly (p < 0.05 associated with specific socio-demographic and medical variables (gender, type of pathology, type of HSCT, time elapsed between communication of the need to transplant and effective transplantation, and days of hospitalization. With regard to the narrative analyses, males focused on expressions related to the body and medical therapies, while females focused on people they met during treatment, family members, and donors. Low general health and treatment with autologous HSCT were associated with memories about chemotherapy, radiotherapy, and the body parts involved, while high general health was associated with expressions focused on gratitude (V

  9. Ayanin diacetate-induced cell death is amplified by TRAIL in human leukemia cells

    International Nuclear Information System (INIS)

    Marrero, María Teresa; Estévez, Sara; Negrín, Gledy; Quintana, José; López, Mariana; Pérez, Francisco J.; Triana, Jorge; León, Francisco; Estévez, Francisco

    2012-01-01

    Highlights: ► Ayanin diacetate as apoptotic inducer in leukemia cells. ► Cell death was prevented by caspase inhibitors and by the overexpression of Bcl-x L . ► The intrinsic and the extrinsic pathways are involved in the mechanism of action. ► Death receptors are up-regulated and TRAIL enhances apoptotic cell death. -- Abstract: Here we demonstrate that the semi-synthetic flavonoid ayanin diacetate induces cell death selectively in leukemia cells without affecting the proliferation of normal lymphocytes. Incubation of human leukemia cells with ayanin diacetate induced G 2 -M phase cell cycle arrest and apoptosis which was prevented by the non-specific caspase inhibitor z-VAD-fmk and reduced by the overexpression of Bcl-x L . Ayanin diacetate-induced cell death was found to be associated with: (i) loss of inner mitochondrial membrane potential, (ii) the release of cytochrome c, (iii) the activation of multiple caspases, (iv) cleavage of poly(ADP-ribose) polymerase and (v) the up-regulation of death receptors for TRAIL, DR4 and DR5. Moreover, the combined treatment with ayanin diacetate and TRAIL amplified cell death, compared to single treatments. These results provide a basis for further exploring the potential applications of this combination for the treatment of cancer.

  10. Ayanin diacetate-induced cell death is amplified by TRAIL in human leukemia cells

    Energy Technology Data Exchange (ETDEWEB)

    Marrero, Maria Teresa; Estevez, Sara; Negrin, Gledy; Quintana, Jose [Departamento de Bioquimica, Unidad Asociada al Consejo Superior de Investigaciones Cientificas, Universidad de Las Palmas de Gran Canaria, Plaza Dr. Pasteur s/n, 35016 Las Palmas de Gran Canaria (Spain); Lopez, Mariana; Perez, Francisco J.; Triana, Jorge [Departamento de Quimica, Universidad de Las Palmas de Gran Canaria, Instituto Canario de Investigacion del Cancer, 35017 Las Palmas de Gran Canaria (Spain); Leon, Francisco [Instituto de Productos Naturales y Agrobiologia, Consejo Superior de Investigaciones Cientificas, Avda. Astrofisico F. Sanchez 3, 38206 La Laguna, Tenerife (Spain); Estevez, Francisco, E-mail: festevez@dbbf.ulpgc.es [Departamento de Bioquimica, Unidad Asociada al Consejo Superior de Investigaciones Cientificas, Universidad de Las Palmas de Gran Canaria, Plaza Dr. Pasteur s/n, 35016 Las Palmas de Gran Canaria (Spain)

    2012-11-09

    Highlights: Black-Right-Pointing-Pointer Ayanin diacetate as apoptotic inducer in leukemia cells. Black-Right-Pointing-Pointer Cell death was prevented by caspase inhibitors and by the overexpression of Bcl-x{sub L}. Black-Right-Pointing-Pointer The intrinsic and the extrinsic pathways are involved in the mechanism of action. Black-Right-Pointing-Pointer Death receptors are up-regulated and TRAIL enhances apoptotic cell death. -- Abstract: Here we demonstrate that the semi-synthetic flavonoid ayanin diacetate induces cell death selectively in leukemia cells without affecting the proliferation of normal lymphocytes. Incubation of human leukemia cells with ayanin diacetate induced G{sub 2}-M phase cell cycle arrest and apoptosis which was prevented by the non-specific caspase inhibitor z-VAD-fmk and reduced by the overexpression of Bcl-x{sub L}. Ayanin diacetate-induced cell death was found to be associated with: (i) loss of inner mitochondrial membrane potential, (ii) the release of cytochrome c, (iii) the activation of multiple caspases, (iv) cleavage of poly(ADP-ribose) polymerase and (v) the up-regulation of death receptors for TRAIL, DR4 and DR5. Moreover, the combined treatment with ayanin diacetate and TRAIL amplified cell death, compared to single treatments. These results provide a basis for further exploring the potential applications of this combination for the treatment of cancer.

  11. The role of mitochondria in yeast programmed cell death

    International Nuclear Information System (INIS)

    Guaragnella, Nicoletta; Ždralević, Maša; Antonacci, Lucia; Passarella, Salvatore; Marra, Ersilia; Giannattasio, Sergio

    2012-01-01

    Mammalian apoptosis and yeast programmed cell death (PCD) share a variety of features including reactive oxygen species production, protease activity and a major role played by mitochondria. In view of this, and of the distinctive characteristics differentiating yeast and multicellular organism PCD, the mitochondrial contribution to cell death in the genetically tractable yeast Saccharomyces cerevisiae has been intensively investigated. In this mini-review we report whether and how yeast mitochondrial function and proteins belonging to oxidative phosphorylation, protein trafficking into and out of mitochondria, and mitochondrial dynamics, play a role in PCD. Since in PCD many processes take place over time, emphasis will be placed on an experimental model based on acetic acid-induced PCD (AA-PCD) which has the unique feature of having been investigated as a function of time. As will be described there are at least two AA-PCD pathways each with a multifaceted role played by mitochondrial components, in particular by cytochrome c.

  12. Detection of programmed cell death in plant embryos.

    Science.gov (United States)

    Filonova, Lada H; Suárez, María F; Bozhkov, Peter V

    2008-01-01

    Programmed cell death (PCD) is an integral part of embryogenesis. In plant embryos, PCD functions during terminal differentiation and elimination of the temporary organ, suspensor, as well as during establishment of provascular system. Embryo abortion is another example of embryonic PCD activated at pathological situations and in polyembryonic seeds. Recent studies identified the sequence of cytological events leading to cellular self-destruction in plant embryos. As in most if not all the developmental cell deaths in plants, embryonic PCD is hallmarked by autophagic degradation of the cytoplasm and nuclear disassembly that includes breakdown of the nuclear envelope and DNA fragmentation. The optimized setup of terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) allows the routine in situ analysis of nuclear DNA fragmentation in plant embryos. This chapter provides step-by-step procedure of how to process embryos for TUNEL and how to combine TUNEL with immunolocalization of the protein of interest.

  13. A contribution of glutathione to interphase death of dividing cells

    International Nuclear Information System (INIS)

    Rybina, V.V.; Korystov, Yu.N.; Degtyareva, O.V.; Dobrovinskaya, O.R.; Ehjdus, L.Kh.

    1988-01-01

    A study was made of a change in the content of reduced glutathionine (GSH) in Ehrlich ascites tumor (EAT) cells after irradiation with doses evoking their interphase death (ID). GSH content was determined in a suspension of EAT cells fixed by hot ethanol. The postirradiation decrease in the GSH content of the suspension was due to its oxidation by hydrogen peroxide resulting from radiochemical reactions after releasing thereof from cells upon fixation. In the absence of an irradiated medium no changes occurred in the GSH content of EAT cells. It is concluded that ID of EAT cells is not associated with the radiation-induced decrease in the content of GSH, an endogenous antioxidant

  14. Targeted cancer cell death induced by biofunctionalized magnetic nanowires

    KAUST Repository

    Contreras, Maria F.

    2014-02-01

    Magnetic micro and nanomaterials are increasingly interesting for biomedical applications since they possess many advantageous properties: they can become biocompatible, they can be functionalized to target specific cells and they can be remotely manipulated by magnetic fields. The goal of this study is to use antibody-functionalized nickel nanowires (Ab-NWs) as an alternative method in cancer therapy overcoming the limitations of current treatments that lack specificity and are highly cytotoxic. Ab-NWs have been incubated with cancer cells and a 12% drop on cell viability was observed for a treatment of only 10 minutes and an alternating magnetic field of low intensity and low frequency. It is believed that the Ab-NWs vibrate transmitting a mechanical force to the targeted cells inducing cell death. © 2014 IEEE.

  15. Targeted cancer cell death induced by biofunctionalized magnetic nanowires

    KAUST Repository

    Contreras, Maria F.; Ravasi, Timothy; Kosel, Jü rgen

    2014-01-01

    Magnetic micro and nanomaterials are increasingly interesting for biomedical applications since they possess many advantageous properties: they can become biocompatible, they can be functionalized to target specific cells and they can be remotely manipulated by magnetic fields. The goal of this study is to use antibody-functionalized nickel nanowires (Ab-NWs) as an alternative method in cancer therapy overcoming the limitations of current treatments that lack specificity and are highly cytotoxic. Ab-NWs have been incubated with cancer cells and a 12% drop on cell viability was observed for a treatment of only 10 minutes and an alternating magnetic field of low intensity and low frequency. It is believed that the Ab-NWs vibrate transmitting a mechanical force to the targeted cells inducing cell death. © 2014 IEEE.

  16. Curcumin induces apoptosis-independent death in oesophageal cancer cells.

    LENUS (Irish Health Repository)

    O'Sullivan-Coyne, G

    2012-01-31

    BACKGROUND: Oesophageal cancer incidence is increasing and survival rates remain extremely poor. Natural agents with potential for chemoprevention include the phytochemical curcumin (diferuloylmethane). We have examined the effects of curcumin on a panel of oesophageal cancer cell lines. METHODS: MTT (3-(4,5-dimethyldiazol-2-yl)-2,5 diphenyl tetrazolium bromide) assays and propidium iodide staining were used to assess viability and DNA content, respectively. Mitotic catastrophe (MC), apoptosis and autophagy were defined by both morphological criteria and markers such as MPM-2, caspase 3 cleavage and monodansylcadaverine (MDC) staining. Cyclin B and poly-ubiquitinated proteins were assessed by western blotting. RESULTS: Curcumin treatment reduces viability of all cell lines within 24 h of treatment in a 5-50 muM range. Cytotoxicity is associated with accumulation in G2\\/M cell-cycle phases and distinct chromatin morphology, consistent with MC. Caspase-3 activation was detected in two out of four cell lines, but was a minor event. The addition of a caspase inhibitor zVAD had a marginal or no effect on cell viability, indicating predominance of a non-apoptotic form of cell death. In two cell lines, features of both MC and autophagy were apparent. Curcumin-responsive cells were found to accumulate poly-ubiquitinated proteins and cyclin B, consistent with a disturbance of the ubiquitin-proteasome system. This effect on a key cell-cycle checkpoint regulator may be responsible for the mitotic disturbances and consequent cytotoxicity of this drug. CONCLUSION: Curcumin can induce cell death by a mechanism that is not reliant on apoptosis induction, and thus represents a promising anticancer agent for prevention and treatment of oesophageal cancer.

  17. Curcumin induces apoptosis-independent death in oesophageal cancer cells.

    LENUS (Irish Health Repository)

    O'Sullivan-Coyne, G

    2009-10-06

    Background:Oesophageal cancer incidence is increasing and survival rates remain extremely poor. Natural agents with potential for chemoprevention include the phytochemical curcumin (diferuloylmethane). We have examined the effects of curcumin on a panel of oesophageal cancer cell lines.Methods:MTT (3-(4,5-dimethyldiazol-2-yl)-2,5 diphenyl tetrazolium bromide) assays and propidium iodide staining were used to assess viability and DNA content, respectively. Mitotic catastrophe (MC), apoptosis and autophagy were defined by both morphological criteria and markers such as MPM-2, caspase 3 cleavage and monodansylcadaverine (MDC) staining. Cyclin B and poly-ubiquitinated proteins were assessed by western blotting.Results:Curcumin treatment reduces viability of all cell lines within 24 h of treatment in a 5-50 muM range. Cytotoxicity is associated with accumulation in G2\\/M cell-cycle phases and distinct chromatin morphology, consistent with MC. Caspase-3 activation was detected in two out of four cell lines, but was a minor event. The addition of a caspase inhibitor zVAD had a marginal or no effect on cell viability, indicating predominance of a non-apoptotic form of cell death. In two cell lines, features of both MC and autophagy were apparent. Curcumin-responsive cells were found to accumulate poly-ubiquitinated proteins and cyclin B, consistent with a disturbance of the ubiquitin-proteasome system. This effect on a key cell-cycle checkpoint regulator may be responsible for the mitotic disturbances and consequent cytotoxicity of this drug.Conclusion:Curcumin can induce cell death by a mechanism that is not reliant on apoptosis induction, and thus represents a promising anticancer agent for prevention and treatment of oesophageal cancer.British Journal of Cancer advance online publication, 6 October 2009; doi:10.1038\\/sj.bjc.6605308 www.bjcancer.com.

  18. Vacuolar processing enzyme in plant programmed cell death

    Directory of Open Access Journals (Sweden)

    Noriyuki eHatsugai

    2015-04-01

    Full Text Available Vacuolar processing enzyme (VPE is a cysteine proteinase originally identified as the proteinase responsible for the maturation and activation of vacuolar proteins in plants, and it is known to be an orthologue of animal asparaginyl endopeptidase (AEP/VPE/legumain. VPE has been shown to exhibit enzymatic properties similar to that of caspase 1, which is a cysteine protease that mediates the programmed cell death (PCD pathway in animals. Although there is limited sequence identity between VPE and caspase 1, their predicted three-dimensional structures revealed that the essential amino-acid residues for these enzymes form similar pockets for the substrate peptide YVAD. In contrast to the cytosolic localization of caspases, VPE is localized in vacuoles. VPE provokes vacuolar rupture, initiating the proteolytic cascade leading to PCD in the plant immune response. It has become apparent that the VPE-dependent PCD pathway is involved not only in the immune response, but also in the responses to a variety of stress inducers and in the development of various tissues. This review summarizes the current knowledge on the contribution of VPE to plant PCD and its role in vacuole-mediated cell death, and it also compares VPE with the animal cell death executor caspase 1.

  19. Molecular mechanisms of Ebola virus pathogenesis: focus on cell death.

    Science.gov (United States)

    Falasca, L; Agrati, C; Petrosillo, N; Di Caro, A; Capobianchi, M R; Ippolito, G; Piacentini, M

    2015-08-01

    Ebola virus (EBOV) belongs to the Filoviridae family and is responsible for a severe disease characterized by the sudden onset of fever and malaise accompanied by other non-specific signs and symptoms; in 30-50% of cases hemorrhagic symptoms are present. Multiorgan dysfunction occurs in severe forms with a mortality up to 90%. The EBOV first attacks macrophages and dendritic immune cells. The innate immune reaction is characterized by a cytokine storm, with secretion of numerous pro-inflammatory cytokines, which induces a huge number of contradictory signals and hurts the immune cells, as well as other tissues. Other highly pathogenic viruses also trigger cytokine storms, but Filoviruses are thought to be particularly lethal because they affect a wide array of tissues. In addition to the immune system, EBOV attacks the spleen and kidneys, where it kills cells that help the body to regulate its fluid and chemical balance and that make proteins that help the blood to clot. In addition, EBOV causes liver, lungs and kidneys to shut down their functions and the blood vessels to leak fluid into surrounding tissues. In this review, we analyze the molecular mechanisms at the basis of Ebola pathogenesis with a particular focus on the cell death pathways induced by the virus. We also discuss how the treatment of the infection can benefit from the recent experience of blocking/modulating cell death in human degenerative diseases.

  20. The molecular basis of retinal ganglion cell death in glaucoma.

    Science.gov (United States)

    Almasieh, Mohammadali; Wilson, Ariel M; Morquette, Barbara; Cueva Vargas, Jorge Luis; Di Polo, Adriana

    2012-03-01

    Glaucoma is a group of diseases characterized by progressive optic nerve degeneration that results in visual field loss and irreversible blindness. A crucial element in the pathophysiology of all forms of glaucoma is the death of retinal ganglion cells (RGCs), a population of CNS neurons with their soma in the inner retina and axons in the optic nerve. Strategies that delay or halt RGC loss have been recognized as potentially beneficial to preserve vision in glaucoma; however, the success of these approaches depends on an in-depth understanding of the mechanisms that lead to RGC dysfunction and death. In recent years, there has been an exponential increase in valuable information regarding the molecular basis of RGC death stemming from animal models of acute and chronic optic nerve injury as well as experimental glaucoma. The emerging landscape is complex and points at a variety of molecular signals - acting alone or in cooperation - to promote RGC death. These include: axonal transport failure, neurotrophic factor deprivation, toxic pro-neurotrophins, activation of intrinsic and extrinsic apoptotic signals, mitochondrial dysfunction, excitotoxic damage, oxidative stress, misbehaving reactive glia and loss of synaptic connectivity. Collectively, this body of work has considerably updated and expanded our view of how RGCs might die in glaucoma and has revealed novel, potential targets for neuroprotection. Copyright © 2011. Published by Elsevier Ltd.

  1. Crystalline structure of pulverized dental calculus induces cell death in oral epithelial cells.

    Science.gov (United States)

    Ziauddin, S M; Yoshimura, A; Montenegro Raudales, J L; Ozaki, Y; Higuchi, K; Ukai, T; Kaneko, T; Miyazaki, T; Latz, E; Hara, Y

    2018-06-01

    Dental calculus is a mineralized deposit attached to the tooth surface. We have shown that cellular uptake of dental calculus triggers nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome activation, leading to the processing of the interleukin-1β precursor into its mature form in mouse and human phagocytes. The activation of the NLRP3 inflammasome also induced a lytic form of programmed cell death, pyroptosis, in these cells. However, the effects of dental calculus on other cell types in periodontal tissue have not been investigated. The aim of this study was to determine whether dental calculus can induce cell death in oral epithelial cells. HSC-2 human oral squamous carcinoma cells, HOMK107 human primary oral epithelial cells and immortalized mouse macrophages were exposed to dental calculus or 1 of its components, hydroxyapatite crystals. For inhibition assays, the cells were exposed to dental calculus in the presence or absence of cytochalasin D (endocytosis inhibitor), z-YVAD-fmk (caspase-1 inhibitor) or glyburide (NLRP3 inflammasome inhibitor). Cytotoxicity was determined by measuring lactate dehydrogenase (LDH) release and staining with propidium iodide. Tumor necrosis factor-α production was quantified by enzyme-linked immunosorbent assay. Oral epithelial barrier function was examined by permeability assay. Dental calculus induced cell death in HSC-2 cells, as judged by LDH release and propidium iodide staining. Dental calculus also induced LDH release from HOMK107 cells. Following heat treatment, dental calculus lost its capacity to induce tumor necrosis factor-α in mouse macrophages, but could induce LDH release in HSC-2 cells, indicating a major role of inorganic components in cell death. Hydroxyapatite crystals also induced cell death in both HSC-2 and HOMK107 cells, as judged by LDH release, indicating the capacity of crystal particles to induce cell death. Cell death induced by dental

  2. Live-cell visualization of gasdermin D-driven pyroptotic cell death.

    Science.gov (United States)

    Rathkey, Joseph K; Benson, Bryan L; Chirieleison, Steven M; Yang, Jie; Xiao, Tsan S; Dubyak, George R; Huang, Alex Y; Abbott, Derek W

    2017-09-01

    Pyroptosis is a form of cell death important in defenses against pathogens that can also result in a potent and sometimes pathological inflammatory response. During pyroptosis, GSDMD (gasdermin D), the pore-forming effector protein, is cleaved, forms oligomers, and inserts into the membranes of the cell, resulting in rapid cell death. However, the potent cell death induction caused by GSDMD has complicated our ability to understand the biology of this protein. Studies aimed at visualizing GSDMD have relied on expression of GSDMD fragments in epithelial cell lines that naturally lack GSDMD expression and also lack the proteases necessary to cleave GSDMD. In this work, we performed mutagenesis and molecular modeling to strategically place tags and fluorescent proteins within GSDMD that support native pyroptosis and facilitate live-cell imaging of pyroptotic cell death. Here, we demonstrate that these fusion proteins are cleaved by caspases-1 and -11 at Asp-276. Mutations that disrupted the predicted p30-p20 autoinhibitory interface resulted in GSDMD aggregation, supporting the oligomerizing activity of these mutations. Furthermore, we show that these novel GSDMD fusions execute inflammasome-dependent pyroptotic cell death in response to multiple stimuli and allow for visualization of the morphological changes associated with pyroptotic cell death in real time. This work therefore provides new tools that not only expand the molecular understanding of pyroptosis but also enable its direct visualization. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  3. Destabilization of Akt Promotes the Death of Myeloma Cell Lines

    Directory of Open Access Journals (Sweden)

    Yanan Zhang

    2014-01-01

    Full Text Available Constitutive activation of Akt is believed to be an oncogenic signal in multiple myeloma and is associated with poor patient prognosis and resistance to available treatment. The stability of Akt proteins is regulated by phosphorylating the highly conserved turn motif (TM of these proteins and the chaperone protein HSP90. In this study we investigate the antitumor effects of inhibiting mTORC2 plus HSP90 in myeloma cell lines. We show that chronic exposure of cells to rapamycin can inhibit mTORC2 pathway, and AKT will be destabilized by administration of the HSP90 inhibitor 17-allylamino-geldanamycin (17-AAG. Finally, we show that the rapamycin synergizes with 17-AAG and inhibits myeloma cells growth and promotes cell death to a greater extent than either drug alone. Our studies provide a clinical rationale of use mTOR inhibitors and chaperone protein inhibitors in combination regimens for the treatment of human blood cancers.

  4. Programmed Cell Death and Caspase Functions During Neural Development.

    Science.gov (United States)

    Yamaguchi, Yoshifumi; Miura, Masayuki

    2015-01-01

    Programmed cell death (PCD) is a fundamental component of nervous system development. PCD serves as the mechanism for quantitative matching of the number of projecting neurons and their target cells through direct competition for neurotrophic factors in the vertebrate peripheral nervous system. In addition, PCD plays roles in regulating neural cell numbers, canceling developmental errors or noise, and tissue remodeling processes. These findings are mainly derived from genetic studies that prevent cells from dying by apoptosis, which is a major form of PCD and is executed by activation of evolutionarily conserved cysteine protease caspases. Recent studies suggest that caspase activation can be coordinated in time and space at multiple levels, which might underlie nonapoptotic roles of caspases in neural development in addition to apoptotic roles. © 2015 Elsevier Inc. All rights reserved.

  5. Mitochondrial control of cell death induced by hyperosmotic stress.

    Science.gov (United States)

    Criollo, Alfredo; Galluzzi, Lorenzo; Maiuri, M Chiara; Tasdemir, Ezgi; Lavandero, Sergio; Kroemer, Guido

    2007-01-01

    HeLa and HCT116 cells respond differentially to sorbitol, an osmolyte able to induce hypertonic stress. In these models, sorbitol promoted the phenotypic manifestations of early apoptosis followed by complete loss of viability in a time-, dose-, and cell type-specific fashion, by eliciting distinct yet partially overlapping molecular pathways. In HCT116 but not in HeLa cells, sorbitol caused the mitochondrial release of the caspase-independent death effector AIF, whereas in both cell lines cytochrome c was retained in mitochondria. Despite cytochrome c retention, HeLa cells exhibited the progressive activation of caspase-3, presumably due to the prior activation of caspase-8. Accordingly, caspase inhibition prevented sorbitol-induced killing in HeLa, but only partially in HCT116 cells. Both the knock-out of Bax in HCT116 cells and the knock-down of Bax in A549 cells by RNA interference reduced the AIF release and/or the mitochondrial alterations. While the knock-down of Bcl-2/Bcl-X(L) sensitized to sorbitol-induced killing, overexpression of a Bcl-2 variant that specifically localizes to mitochondria (but not of the wild-type nor of a endoplasmic reticulum-targeted form) strongly inhibited sorbitol effects. Thus, hyperosmotic stress kills cells by triggering different molecular pathways, which converge at mitochondria where pro- and anti-apoptotic members of the Bcl-2 family exert their control.

  6. Caspases in retinal ganglion cell death and axon regeneration

    Science.gov (United States)

    Thomas, Chloe N; Berry, Martin; Logan, Ann; Blanch, Richard J; Ahmed, Zubair

    2017-01-01

    Retinal ganglion cells (RGC) are terminally differentiated CNS neurons that possess limited endogenous regenerative capacity after injury and thus RGC death causes permanent visual loss. RGC die by caspase-dependent mechanisms, including apoptosis, during development, after ocular injury and in progressive degenerative diseases of the eye and optic nerve, such as glaucoma, anterior ischemic optic neuropathy, diabetic retinopathy and multiple sclerosis. Inhibition of caspases through genetic or pharmacological approaches can arrest the apoptotic cascade and protect a proportion of RGC. Novel findings have also highlighted a pyroptotic role of inflammatory caspases in RGC death. In this review, we discuss the molecular signalling mechanisms of apoptotic and inflammatory caspase responses in RGC specifically, their involvement in RGC degeneration and explore their potential as therapeutic targets. PMID:29675270

  7. Methuosis: Nonapoptotic Cell Death Associated with Vacuolization of Macropinosome and Endosome Compartments

    OpenAIRE

    Maltese, William A.; Overmeyer, Jean H.

    2014-01-01

    Apoptosis is the most widely recognized form of physiological programmed cell death. During the past three decades, various nonapoptotic forms of cell death have gained increasing attention, largely because of their potential importance in pathological processes, toxicology, and cancer therapy. A recent addition to the panoply of cell death phenotypes is methuosis. The neologism is derived from the Greek methuo (to drink to intoxication) because the hallmark of this form of cell death is disp...

  8. Caspase-independent cell death mediated by apoptosis-inducing factor (AIF) nuclear translocation is involved in ionizing radiation induced HepG2 cell death

    International Nuclear Information System (INIS)

    Sun, Hengwen; Yang, Shana; Li, Jianhua; Zhang, Yajie; Gao, Dongsheng; Zhao, Shenting

    2016-01-01

    Hepatocellular carcinoma (HCC) is the fifth most common cancer in the world. The aim of radiotherapy is to eradicate cancer cells with ionizing radiation. Except for the caspase-dependent mechanism, several lines of evidence demonstrated that caspase-independent mechanism is directly involved in the cell death responding to irradiation. For this reason, defining the contribution of caspase-independent molecular mechanisms represents the main goal in radiotherapy. In this study, we focused on the role of apoptosis-inducing factor (AIF), the caspase-independent molecular, in ionizing radiation induced hepatocellular carcinoma cell line (HepG2) cell death. We found that ionizing radiation has no function on AIF expression in HepG2 cells, but could induce AIF release from the mitochondria and translocate into nuclei. Inhibition of AIF could reduce ionizing radiation induced HepG2 cell death. These studies strongly support a direct relationship between AIF nuclear translocation and radiation induced cell death. What's more, AIF nuclear translocation is caspase-independent manner, but not caspase-dependent manner, in this process. These new findings add a further attractive point of investigation to better define the complex interplay between caspase-independent cell death and radiation therapy. - Highlights: • AIF nuclear translocation is involved in ionizing radiation induced hepatocellular carcinoma cell line HepG2 cell death. • AIF mediated cell death induced by ionizing radiation is caspase-independent. • Caspase-independent pathway is involved in ionzing radiation induced HepG2 cell death.

  9. Modulating cell-to-cell variability and sensitivity to death ligands by co-drugging

    International Nuclear Information System (INIS)

    Flusberg, Deborah A; Sorger, Peter K

    2013-01-01

    TRAIL (tumor necrosis factor-related apoptosis-inducing ligand) holds promise as an anti-cancer therapeutic but efficiently induces apoptosis in only a subset of tumor cell lines. Moreover, even in clonal populations of responsive lines, only a fraction of cells dies in response to TRAIL and individual cells exhibit cell-to-cell variability in the timing of cell death. Fractional killing in these cell populations appears to arise not from genetic differences among cells but rather from differences in gene expression states, fluctuations in protein levels and the extent to which TRAIL-induced death or survival pathways become activated. In this study, we ask how cell-to-cell variability manifests in cell types with different sensitivities to TRAIL, as well as how it changes when cells are exposed to combinations of drugs. We show that individual cells that survive treatment with TRAIL can regenerate the sensitivity and death-time distribution of the parental population, demonstrating that fractional killing is a stable property of cell populations. We also show that cell-to-cell variability in the timing and probability of apoptosis in response to treatment can be tuned using combinations of drugs that together increase apoptotic sensitivity compared to treatment with one drug alone. In the case of TRAIL, modulation of cell-to-cell variability by co-drugging appears to involve a reduction in the threshold for mitochondrial outer membrane permeabilization. (paper)

  10. Bimodal cell death induced by high radiation doses in the radioresistant sf9 insect cell line

    International Nuclear Information System (INIS)

    Chandna, S.

    2003-01-01

    Full text: This study was conducted to investigate the mode(s) of cell death induced by high radiation doses in the highly radioresistant Sf9 insect ovarian cell line. Methods: Cells were exposed to γ-radiation doses 200Gy and 500Gy, harvested at various time intervals (6h-72h) following irradiation, and subjected to cell morphology assay, DNA agarose gel electrophoresis, single cell gel electrophoresis (SCGE; comet assay) and Annexin-V labeling for the detection of membrane phosphatidylserine externalization. Cell morphology was assessed in cells entrapped and fixed in agarose gel directly from the cell suspension, thus preventing the possible loss of fragments/ apoptotic bodies. Surviving fraction of Sf9 cells was 0.01 at 200Gy and 98%) undergoing extensive DNA fragmentation at 500Gy, whereas the frequency of cells with DNA fragmentation was considerably less (∼12%) at 200Gy. Conclusions: While the mode of cell death at 200Gy seems to be different from typical apoptosis, a dose of 500Gy induced bimodal cell death, with typical apoptotic as well as the atypical cell death observed at 200Gy

  11. Bifurcate effects of glucose on caspase-independent cell death during hypoxia

    International Nuclear Information System (INIS)

    Aki, Toshihiko; Nara, Akina; Funakoshi, Takeshi; Uemura, Koichi

    2010-01-01

    We investigated the effect of glucose on hypoxic death of rat cardiomyocyte-derived H9c2 cells and found that there is an optimal glucose concentration for protection against hypoxic cell death. Hypoxic cell death in the absence of glucose is accompanied by rapid ATP depletion, release of apoptosis-inducing factor from mitochondria, and nuclear chromatin condensation, all of which are inhibited by glucose in a dose-dependent manner. In contrast, excessive glucose also induces hypoxic cell death that is not accompanied by these events, suggesting a change in the mode of cell death between hypoxic cells with and without glucose supplementation.

  12. Only in dying, life: programmed cell death during plant development.

    Science.gov (United States)

    Van Hautegem, Tom; Waters, Andrew J; Goodrich, Justin; Nowack, Moritz K

    2015-02-01

    Programmed cell death (PCD) is a fundamental process of life. During the evolution of multicellular organisms, the actively controlled demise of cells has been recruited to fulfil a multitude of functions in development, differentiation, tissue homeostasis, and immune systems. In this review we discuss some of the multiple cases of PCD that occur as integral parts of plant development in a remarkable variety of cell types, tissues, and organs. Although research in the last decade has discovered a number of PCD regulators, mediators, and executers, we are still only beginning to understand the mechanistic complexity that tightly controls preparation, initiation, and execution of PCD as a process that is indispensable for successful vegetative and reproductive development of plants. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Nitrosothiol signaling and protein nitrosation in cell death.

    Science.gov (United States)

    Iyer, Anand Krishnan V; Rojanasakul, Yon; Azad, Neelam

    2014-11-15

    Nitric oxide, a reactive free radical, is an important signaling molecule that can lead to a plethora of cellular effects affecting homeostasis. A well-established mechanism by which NO manifests its effect on cellular functions is the post-translational chemical modification of cysteine thiols in substrate proteins by a process known as S-nitrosation. Studies that investigate regulation of cellular functions through NO have increasingly established S-nitrosation as the primary modulatory mechanism in their respective systems. There has been a substantial increase in the number of reports citing various candidate proteins undergoing S-nitrosation, which affects cell-death and -survival pathways in a number of tissues including heart, lung, brain and blood. With an exponentially growing list of proteins being identified as substrates for S-nitrosation, it is important to assimilate this information in different cell/tissue systems in order to gain an overall view of protein regulation of both individual proteins and a class of protein substrates. This will allow for broad mapping of proteins as a function of S-nitrosation, and help delineate their global effects on pathophysiological responses including cell death and survival. This information will not only provide a much better understanding of overall functional relevance of NO in the context of various disease states, it will also facilitate the generation of novel therapeutics to combat specific diseases that are driven by NO-mediated S-nitrosation. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Metal stress induces programmed cell death in aquatic fungi

    International Nuclear Information System (INIS)

    Azevedo, Maria-Manuel; Almeida, Bruno; Ludovico, Paula; Cassio, Fernanda

    2009-01-01

    Aquatic hyphomycetes are a group of fungi that play a key role in organic matter turnover in both clean and metal-polluted streams. We examined the ability of Cu or Zn to induce programmed cell death (PCD) in three aquatic hyphomycete species through the evaluation of typical apoptotic markers, namely reactive oxygen species (ROS) accumulation, caspase-like activity, nuclear morphological alterations, and the occurrence of DNA strand breaks assessed by TUNEL assay. The exposure to both metals induced apoptotic events in all tested aquatic fungi. The most tolerant fungi either to Zn (Varicosporium elodeae) or Cu (Heliscussubmersus) exhibited higher levels of PCD markers, suggesting that PCD processes might be linked to fungal resistance/tolerance to metal stress. Moreover, different patterns of apoptotic markers were found, namely a PCD process independent of ROS accumulation in V. elodeae exposed to Cu, or independent of caspase-like activity in Flagellospora curta exposed to Zn, or even without the occurrence of DNA strand breaks in F. curta exposed to Cu. This suggests that a multiplicity of PCD pathways might be operating in aquatic hyphomycetes. The occurrence of a tightly regulated cell death pathway, such as PCD, in aquatic hyphomycetes under metal stress might be a part of the mechanisms underlying fungal acclimation in metal-polluted streams, because it would allow the rapid removal of unwanted or damaged cells sparing nutrients and space for the fittest ones.

  15. Anhydrobiosis and programmed cell death in plants: Commonalities and Differences

    Directory of Open Access Journals (Sweden)

    Samer Singh

    2015-05-01

    Full Text Available Anhydrobiosis is an adaptive strategy of certain organisms or specialised propagules to survive in the absence of water while programmed cell death (PCD is a finely tuned cellular process of the selective elimination of targeted cell during developmental programme and perturbed biotic and abiotic conditions. Particularly during water stress both the strategies serve single purpose i.e., survival indicating PCD may also function as an adaptive process under certain conditions. During stress conditions PCD cause targeted cells death in order to keep the homeostatic balance required for the organism survival, whereas anhydrobiosis suspends cellular metabolic functions mimicking a state similar to death until reestablishment of the favourable conditions. Anhydrobiosis is commonly observed among organisms that have ability to revive their metabolism on rehydration after removal of all or almost all cellular water without damage. This feature is widely represented in terrestrial cyanobacteria and bryophytes where it is very common in both vegetative and reproductive stages of life-cycle. In the course of evolution, with the development of advanced vascular system in higher plants, anhydrobiosis was gradually lost from the vegetative phase of life-cycle. Though it is retained in resurrection plants that primarily belong to thallophytes and a small group of vascular angiosperm, it can be mostly found restricted in orthodox seeds of higher plants. On the contrary, PCD is a common process in all eukaryotes from unicellular to multicellular organisms including higher plants and mammals. In this review we discuss physiological and biochemical commonalities and differences between anhydrobiosis and PCD.

  16. Ras and Rheb Signaling in Survival and Cell Death

    International Nuclear Information System (INIS)

    Ehrkamp, Anja; Herrmann, Christian; Stoll, Raphael; Heumann, Rolf

    2013-01-01

    One of the most obvious hallmarks of cancer is uncontrolled proliferation of cells partly due to independence of growth factor supply. A major component of mitogenic signaling is Ras, a small GTPase. It was the first identified human protooncogene and is known since more than three decades to promote cellular proliferation and growth. Ras was shown to support growth factor-independent survival during development and to protect from chemical or mechanical lesion-induced neuronal degeneration in postmitotic neurons. In contrast, for specific patho-physiological cases and cellular systems it has been shown that Ras may also promote cell death. Proteins from the Ras association family (Rassf, especially Rassf1 and Rassf5) are tumor suppressors that are activated by Ras-GTP, triggering apoptosis via e.g., activation of mammalian sterile 20-like (MST1) kinase. In contrast to Ras, their expression is suppressed in many types of tumours, which makes Rassf proteins an exciting model for understanding the divergent effects of Ras activity. It seems likely that the outcome of Ras signaling depends on the balance between the activation of its various downstream effectors, thus determining cellular fate towards either proliferation or apoptosis. Ras homologue enriched in brain (Rheb) is a protein from the Ras superfamily that is also known to promote proliferation, growth, and regeneration through the mammalian target of rapamycin (mTor) pathway. However, recent evidences indicate that the Rheb-mTor pathway may switch its function from a pro-growth into a cell death pathway, depending on the cellular situation. In contrast to Ras signaling, for Rheb, the cellular context is likely to modulate the whole Rheb-mTor pathway towards cellular death or survival, respectively

  17. Ras and Rheb Signaling in Survival and Cell Death

    Energy Technology Data Exchange (ETDEWEB)

    Ehrkamp, Anja [Molecular Neurobiochemistry, Ruhr University of Bochum, 44780 Bochum (Germany); Herrmann, Christian [Department of Physical Chemistry1, Protein Interaction, Ruhr University of Bochum, 44780 Bochum (Germany); Stoll, Raphael [Biomolecular NMR, Ruhr University of Bochum, 44780 Bochum (Germany); Heumann, Rolf, E-mail: rolf.heumann@rub.de [Molecular Neurobiochemistry, Ruhr University of Bochum, 44780 Bochum (Germany)

    2013-05-28

    One of the most obvious hallmarks of cancer is uncontrolled proliferation of cells partly due to independence of growth factor supply. A major component of mitogenic signaling is Ras, a small GTPase. It was the first identified human protooncogene and is known since more than three decades to promote cellular proliferation and growth. Ras was shown to support growth factor-independent survival during development and to protect from chemical or mechanical lesion-induced neuronal degeneration in postmitotic neurons. In contrast, for specific patho-physiological cases and cellular systems it has been shown that Ras may also promote cell death. Proteins from the Ras association family (Rassf, especially Rassf1 and Rassf5) are tumor suppressors that are activated by Ras-GTP, triggering apoptosis via e.g., activation of mammalian sterile 20-like (MST1) kinase. In contrast to Ras, their expression is suppressed in many types of tumours, which makes Rassf proteins an exciting model for understanding the divergent effects of Ras activity. It seems likely that the outcome of Ras signaling depends on the balance between the activation of its various downstream effectors, thus determining cellular fate towards either proliferation or apoptosis. Ras homologue enriched in brain (Rheb) is a protein from the Ras superfamily that is also known to promote proliferation, growth, and regeneration through the mammalian target of rapamycin (mTor) pathway. However, recent evidences indicate that the Rheb-mTor pathway may switch its function from a pro-growth into a cell death pathway, depending on the cellular situation. In contrast to Ras signaling, for Rheb, the cellular context is likely to modulate the whole Rheb-mTor pathway towards cellular death or survival, respectively.

  18. Comparative analysis of programmed cell death pathways in filamentous fungi

    Directory of Open Access Journals (Sweden)

    Wortman Jennifer R

    2005-12-01

    Full Text Available Abstract Background Fungi can undergo autophagic- or apoptotic-type programmed cell death (PCD on exposure to antifungal agents, developmental signals, and stress factors. Filamentous fungi can also exhibit a form of cell death called heterokaryon incompatibility (HI triggered by fusion between two genetically incompatible individuals. With the availability of recently sequenced genomes of Aspergillus fumigatus and several related species, we were able to define putative components of fungi-specific death pathways and the ancestral core apoptotic machinery shared by all fungi and metazoa. Results Phylogenetic profiling of HI-associated proteins from four Aspergilli and seven other fungal species revealed lineage-specific protein families, orphan genes, and core genes conserved across all fungi and metazoa. The Aspergilli-specific domain architectures include NACHT family NTPases, which may function as key integrators of stress and nutrient availability signals. They are often found fused to putative effector domains such as Pfs, SesB/LipA, and a newly identified domain, HET-s/LopB. Many putative HI inducers and mediators are specific to filamentous fungi and not found in unicellular yeasts. In addition to their role in HI, several of them appear to be involved in regulation of cell cycle, development and sexual differentiation. Finally, the Aspergilli possess many putative downstream components of the mammalian apoptotic machinery including several proteins not found in the model yeast, Saccharomyces cerevisiae. Conclusion Our analysis identified more than 100 putative PCD associated genes in the Aspergilli, which may help expand the range of currently available treatments for aspergillosis and other invasive fungal diseases. The list includes species-specific protein families as well as conserved core components of the ancestral PCD machinery shared by fungi and metazoa.

  19. Cell death induced by taxanes in sensitive and resistant breast cancer cells

    Czech Academy of Sciences Publication Activity Database

    Ehrlichová, Marie; Truksa, Jaroslav; Naďová, Zuzana; Gut, I.; Kovář, Jan

    2004-01-01

    Roč. 37, č. 2 (2004), s. 120-121 ISSN 0960-7722. [Meeting of the European study group for cell proliferation /26./. Praha, 13.05.2004-16.05.2004] R&D Projects: GA MZd NL6715 Keywords : breast cancer cells * cell death * taxanes Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.907, year: 2004

  20. Long-term treatment of anterior pituitary cells with nitric oxide induces programmed cell death.

    Science.gov (United States)

    Velardez, Miguel Omar; Poliandri, Ariel Hernán; Cabilla, Jimena Paula; Bodo, Cristian Carlos Armando; Machiavelli, Leticia Inés; Duvilanski, Beatriz Haydeé

    2004-04-01

    Nitric oxide (NO) plays a complex role in modulating programmed cell death. It can either protect the cell from apoptotic death or mediate apoptosis, depending on its concentration and the cell type and/or status. In this study, we demonstrate that long-term exposition to NO induces cell death of anterior pituitary cells from Wistar female rats. DETA NONOate (Z)-1-[2-(2-aminoethyl)-N-(2-ammonioethyl)amino]diazen-1-ium-1,2-diolate, 1 mm], a NO donor that releases NO for an extended period of time, decreased cellular viability and prolactin release from primary cultures of anterior pituitary cells. Morphological studies showed an increase in the number of cells with chromatin condensation and nuclear fragmentation at 24 and 48 h after DETA/NO exposure. DNA internucleosomal fragmentation was also observed at the same time. Reversibility of the NO effect on cellular viability and prolactin release was observed only when the cells were incubated with DETA/NO for less than 6 h. Most apoptotic cells were immunopositive for prolactin, suggesting a high susceptibility of lactotrophs to the effect of NO. The cytotoxic effect of NO is dependent of caspase-9 and caspase-3, but seems to be independent of oxidative stress or nitrosative stress. Our results show that the exposition of anterior pituitary cells to NO for long periods induces programmed cell death of anterior pituitary cells.

  1. Multiple Modes of Cell Death Discovered in a Prokaryotic (Cyanobacterial Endosymbiont.

    Directory of Open Access Journals (Sweden)

    Weiwen Zheng

    Full Text Available Programmed cell death (PCD is a genetically-based cell death mechanism with vital roles in eukaryotes. Although there is limited consensus on similar death mode programs in prokaryotes, emerging evidence suggest that PCD events are operative. Here we present cell death events in a cyanobacterium living endophytically in the fern Azolla microphylla, suggestive of PCD. This symbiosis is characterized by some unique traits such as a synchronized development, a vertical transfer of the cyanobacterium between plant generations, and a highly eroding cyanobacterial genome. A combination of methods was used to identify cell death modes in the cyanobacterium. Light- and electron microscopy analyses showed that the proportion of cells undergoing cell death peaked at 53.6% (average 20% of the total cell population, depending on the cell type and host developmental stage. Biochemical markers used for early and late programmed cell death events related to apoptosis (Annexin V-EGFP and TUNEL staining assays, together with visualization of cytoskeleton alterations (FITC-phalloidin staining, showed that all cyanobacterial cell categories were affected by cell death. Transmission electron microscopy revealed four modes of cell death: apoptotic-like, autophagic-like, necrotic-like and autolytic-like. Abiotic stresses further enhanced cell death in a dose and time dependent manner. The data also suggest that dynamic changes in the peptidoglycan cell wall layer and in the cytoskeleton distribution patterns may act as markers for the various cell death modes. The presence of a metacaspase homolog (domain p20 further suggests that the death modes are genetically programmed. It is therefore concluded that multiple, likely genetically programmed, cell death modes exist in cyanobacteria, a finding that may be connected with the evolution of cell death in the plant kingdom.

  2. Multiple Modes of Cell Death Discovered in a Prokaryotic (Cyanobacterial) Endosymbiont

    Science.gov (United States)

    Zheng, Weiwen; Rasmussen, Ulla; Zheng, Siping; Bao, Xiaodong; Chen, Bin; Gao, Yuan; Guan, Xiong; Larsson, John; Bergman, Birgitta

    2013-01-01

    Programmed cell death (PCD) is a genetically-based cell death mechanism with vital roles in eukaryotes. Although there is limited consensus on similar death mode programs in prokaryotes, emerging evidence suggest that PCD events are operative. Here we present cell death events in a cyanobacterium living endophytically in the fern Azolla microphylla, suggestive of PCD. This symbiosis is characterized by some unique traits such as a synchronized development, a vertical transfer of the cyanobacterium between plant generations, and a highly eroding cyanobacterial genome. A combination of methods was used to identify cell death modes in the cyanobacterium. Light- and electron microscopy analyses showed that the proportion of cells undergoing cell death peaked at 53.6% (average 20%) of the total cell population, depending on the cell type and host developmental stage. Biochemical markers used for early and late programmed cell death events related to apoptosis (Annexin V-EGFP and TUNEL staining assays), together with visualization of cytoskeleton alterations (FITC-phalloidin staining), showed that all cyanobacterial cell categories were affected by cell death. Transmission electron microscopy revealed four modes of cell death: apoptotic-like, autophagic-like, necrotic-like and autolytic-like. Abiotic stresses further enhanced cell death in a dose and time dependent manner. The data also suggest that dynamic changes in the peptidoglycan cell wall layer and in the cytoskeleton distribution patterns may act as markers for the various cell death modes. The presence of a metacaspase homolog (domain p20) further suggests that the death modes are genetically programmed. It is therefore concluded that multiple, likely genetically programmed, cell death modes exist in cyanobacteria, a finding that may be connected with the evolution of cell death in the plant kingdom. PMID:23822984

  3. Attenuation of oxidative neuronal cell death by coffee phenolic phytochemicals

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Eun Sun; Jang, Young Jin [Department of Agricultural Biotechnology and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 151-921 (Korea, Republic of); Hwang, Mun Kyung; Kang, Nam Joo [Department of Agricultural Biotechnology and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 151-921 (Korea, Republic of); Department of Bioscience and Biotechnology, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 143-701 (Korea, Republic of); Lee, Ki Won [Department of Bioscience and Biotechnology, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 143-701 (Korea, Republic of)], E-mail: kiwon@konkuk.ac.kr; Lee, Hyong Joo [Department of Agricultural Biotechnology and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 151-921 (Korea, Republic of)], E-mail: leehyjo@snu.ac.kr

    2009-02-10

    Neurodegenerative disorders such as Alzheimer's disease (AD) are strongly associated with oxidative stress, which is induced by reactive oxygen species (ROS) including hydrogen peroxide (H{sub 2}O{sub 2}). Recent studies suggest that moderate coffee consumption may reduce the risk of neurodegenerative diseases such as AD, but the molecular mechanisms underlying this effect remain to be clarified. In this study, we investigated the protective effects of chlorogenic acid (5-O-caffeoylquinic acid; CGA), a major phenolic phytochemical found in instant decaffeinated coffee (IDC), and IDC against oxidative PC12 neuronal cell death. IDC (1 and 5 {mu}g/ml) or CGA (1 and 5 {mu}M) attenuated H{sub 2}O{sub 2}-induced PC12 cell death. H{sub 2}O{sub 2}-induced nuclear condensation and DNA fragmentation were strongly inhibited by pretreatment with IDC or CGA. Pretreatment with IDC or CGA also inhibited the H{sub 2}O{sub 2}-induced cleavage of poly(ADP-ribose) polymerase (PARP), and downregulation of Bcl-X{sub L} and caspase-3. The accumulation of intracellular ROS in H{sub 2}O{sub 2}-treated PC12 cells was dose-dependently diminished by IDC or CGA. The activation of c-Jun N-terminal protein kinase (JNK) and p38 mitogen-activated protein kinase (MAPK) by H{sub 2}O{sub 2} in PC12 cells was also inhibited by IDC or CGA. Collectively, these results indicate that IDC and CGA protect PC12 cells from H{sub 2}O{sub 2}-induced apoptosis by blocking the accumulation of intracellular ROS and the activation of MAPKs.

  4. Attenuation of oxidative neuronal cell death by coffee phenolic phytochemicals

    International Nuclear Information System (INIS)

    Cho, Eun Sun; Jang, Young Jin; Hwang, Mun Kyung; Kang, Nam Joo; Lee, Ki Won; Lee, Hyong Joo

    2009-01-01

    Neurodegenerative disorders such as Alzheimer's disease (AD) are strongly associated with oxidative stress, which is induced by reactive oxygen species (ROS) including hydrogen peroxide (H 2 O 2 ). Recent studies suggest that moderate coffee consumption may reduce the risk of neurodegenerative diseases such as AD, but the molecular mechanisms underlying this effect remain to be clarified. In this study, we investigated the protective effects of chlorogenic acid (5-O-caffeoylquinic acid; CGA), a major phenolic phytochemical found in instant decaffeinated coffee (IDC), and IDC against oxidative PC12 neuronal cell death. IDC (1 and 5 μg/ml) or CGA (1 and 5 μM) attenuated H 2 O 2 -induced PC12 cell death. H 2 O 2 -induced nuclear condensation and DNA fragmentation were strongly inhibited by pretreatment with IDC or CGA. Pretreatment with IDC or CGA also inhibited the H 2 O 2 -induced cleavage of poly(ADP-ribose) polymerase (PARP), and downregulation of Bcl-X L and caspase-3. The accumulation of intracellular ROS in H 2 O 2 -treated PC12 cells was dose-dependently diminished by IDC or CGA. The activation of c-Jun N-terminal protein kinase (JNK) and p38 mitogen-activated protein kinase (MAPK) by H 2 O 2 in PC12 cells was also inhibited by IDC or CGA. Collectively, these results indicate that IDC and CGA protect PC12 cells from H 2 O 2 -induced apoptosis by blocking the accumulation of intracellular ROS and the activation of MAPKs

  5. HPMA copolymer-bound doxorubicin induces immunogenic tumor cell death.

    Science.gov (United States)

    Sirova, M; Kabesova, M; Kovar, L; Etrych, T; Strohalm, J; Ulbrich, K; Rihova, B

    2013-01-01

    Treatment of murine EL4 T cell lymphoma with N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer conjugates of doxorubicin (Dox) leads to complete tumor regression and to the development of therapy-dependent longlasting cancer resistance. This phenomenon occurs with two types of Dox conjugates tested, despite differences in the covalent linkage of Dox to the polymer carrier. Such a cancer resistance cannot fully express in conventional treatment with free Dox, due to substantial immunotoxicity of the treatment, which was not observed in the polymer conjugates. In this study, calreticulin (CRT) translocation and high mobility group box-1 protein (HMGB1) release was observed in EL4 cells treated with a conjugate releasing Dox by a pH-dependent manner. As a result, the treated tumor cells were engulfed by dendritic cells (DC) in vitro, and induced their expression of CD80, CD86, and MHC II maturation markers. Conjugates with Dox bound via an amide bond only increased translocation of HSPs to the membrane, which led to an elevated phagocytosis but was not sufficient to induce increase of the maturation markers on DCs in vitro. Both types of conjugates induced engulfment of the target tumor cells in vivo, that was more intense than that seen with free Dox. It means that the induction of anti-tumor immunity documented upon treatment of EL4 lymphoma with HPMA-bound Dox conjugates does not rely solely on CRT-mediated cell death, but involves multiple mechanisms.

  6. Acrolein-induced cell death in PC12 cells: role of mitochondria-mediated oxidative stress.

    Science.gov (United States)

    Luo, Jian; Robinson, J Paul; Shi, Riyi

    2005-12-01

    Oxidative stress has been implicated in acrolein cytotoxicity in various cell types, including mammalian spinal cord tissue. In this study we report that acrolein also decreases PC12 cell viability in a reactive oxygen species (ROS)-dependent manner. Specifically, acrolein-induced cell death, mainly necrosis, is accompanied by the accumulation of cellular ROS. Elevating ROS scavengers can alleviate acrolein-induced cell death. Furthermore, we show that exposure to acrolein leads to mitochondrial dysfunction, denoted by the loss of mitochondrial transmembrane potential, reduction of cellular oxygen consumption, and decrease of ATP level. This raises the possibility that the cellular accumulation of ROS could result from the increased production of ROS in the mitochondria of PC12 cells as a result of exposure to acrolein. The acrolein-induced significant decrease of ATP production in mitochondria may also explain why necrosis, not apoptosis, is the dominant type of cell death. In conclusion, our data suggest that one possible mechanism of acrolein-induced cell death could be through mitochondria as its initial target. The subsequent increase of ROS then inflicts cell death and further worsens mitochondria function. Such mechanism may play an important role in CNS trauma and neurodegenerative diseases.

  7. Akebia saponin PA induces autophagic and apoptotic cell death in AGS human gastric cancer cells.

    Science.gov (United States)

    Xu, Mei-Ying; Lee, Dong Hwa; Joo, Eun Ji; Son, Kun Ho; Kim, Yeong Shik

    2013-09-01

    In this study, we investigated the anticancer mechanism of akebia saponin PA (AS), a natural product isolated from Dipsacus asperoides in human gastric cancer cell lines. It was shown that AS-induced cell death is caused by autophagy and apoptosis in AGS cells. The apoptosis-inducing effect of AS was characterized by annexin V/propidium (PI) staining, increase of sub-G1 phase and caspase-3 activation, while the autophagy-inducing effect was indicated by the formation of cytoplasmic vacuoles and microtubule-associated protein 1 light chain-3 II (LC3-II) conversion. The autophagy inhibitor bafilomycin A1 (BaF1) decreased AS-induced cell death and caspase-3 activation, but caspase-3 inhibitor Ac-DEVD-CHO did not affect LC3-II accumulation or AS-induced cell viability, suggesting that AS induces autophagic cell death and autophagy contributes to caspase-3-dependent apoptosis. Furthermore, AS activated p38/c-Jun N-terminal kinase (JNK), which could be inhibited by BaF1, and caspase-3 activation was attenuated by both SB202190 and SP600125, indicating that AS-induced autophagy promotes mitogen-activated protein kinases (MAPKs)-mediated apoptosis. Taken together, these results demonstrate that AS induces autophagic and apoptotic cell death and autophagy plays the main role in akebia saponin PA-induced cell death. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Characterization of a serine protease-mediated cell death program activated in human leukemia cells

    International Nuclear Information System (INIS)

    O'Connell, A.R.; Holohan, C.; Torriglia, A.; Lee, B.F.; Stenson-Cox, C.

    2006-01-01

    Tightly controlled proteolysis is a defining feature of apoptosis and caspases are critical in this regard. Significant roles for non-caspase proteases in cell death have been highlighted. Staurosporine causes a rapid induction of apoptosis in virtually all mammalian cell types. Numerous studies demonstrate that staurosporine can activate cell death under caspase-inhibiting circumstances. The aim of this study was to investigate the proteolytic mechanisms responsible for cell death under these conditions. To that end, we show that inhibitors of serine proteases can delay cell death in one such system. Furthermore, through profiling of proteolytic activation, we demonstrate, for the first time, that staurosporine activates a chymotrypsin-like serine protease-dependent cell death in HL-60 cells independently, but in parallel with the caspase controlled systems. Features of the serine protease-mediated system include cell shrinkage and apoptotic morphology, regulation of caspase-3, altered nuclear morphology, generation of an endonuclease and DNA degradation. We also demonstrate a staurosporine-induced activation of a putative 16 kDa chymotrypsin-like protein during apoptosis

  9. Thymol Elicits HCT-116 Colorectal Carcinoma Cell Death Through Induction of Oxidative Stress.

    Science.gov (United States)

    Chauhan, Anil Kumar; Bahuguna, Ashutosh; Paul, Souren; Kang, Sun Chul

    2018-02-07

    Colon cancer is one of the most deadly and common carcinomas occurring worldwide and there have been many attempts to treat this cancer. The present work was designed in order to evaluate thymol as a potent drug against colon cancer. Cytotoxicity of thymol at different concentrations was evaluated against a human colon carcinoma cell line (HCT-116 cells). Fluorescent staining was carried out to evaluate the level of ROS as well as mitochondrial and DNA fragmentation and immunoblot analysis were performed to confirm apoptosis and mitoptosis. Results of the study demonstrated that thymol efficiently created an oxidative stress environment inside HCT-116 cells, a colorectal carcinoma cell line, through induction of ROS production along with intense damage to DNA and mitochondria, as observed through Hoechst and rhodamine 123 staining, respectively. Moreover, expression of PARP-1, p-JNK, cytochrome-C and caspase-3 proteins was up-regulated, suggesting HCT-116 cells underwent mitoptotic cell death. Therefore, thymol could be used as a potent drug against colon cancer due to its lower toxicity and prevalence in natural medicinal plants. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  10. Early death during chemotherapy in patients with small-cell lung cancer

    DEFF Research Database (Denmark)

    Lassen, U N; Osterlind, K; Hirsch, F R

    1999-01-01

    Based on an increased frequency of early death (death within the first treatment cycle) in our two latest randomized trials of combination chemotherapy in small-cell lung cancer (SCLC), we wanted to identify patients at risk of early non-toxic death (ENTD) and early toxic death (ETD). Data were s...

  11. Inhibition of autophagy induced by proteasome inhibition increases cell death in human SHG-44 glioma cells.

    Science.gov (United States)

    Ge, Peng-Fei; Zhang, Ji-Zhou; Wang, Xiao-Fei; Meng, Fan-Kai; Li, Wen-Chen; Luan, Yong-Xin; Ling, Feng; Luo, Yi-Nan

    2009-07-01

    The ubiquitin-proteasome system (UPS) and lysosome-dependent macroautophagy (autophagy) are two major intracellular pathways for protein degradation. Recent studies suggest that proteasome inhibitors may reduce tumor growth and activate autophagy. Due to the dual roles of autophagy in tumor cell survival and death, the effect of autophagy on the destiny of glioma cells remains unclear. In this study, we sought to investigate whether inhibition of the proteasome can induce autophagy and the effects of autophagy on the fate of human SHG-44 glioma cells. The proteasome inhibitor MG-132 was used to induce autophagy in SHG-44 glioma cells, and the effect of autophagy on the survival of SHG-44 glioma cells was investigated using an autophagy inhibitor 3-MA. Cell viability was measured by MTT assay. Apoptosis and cell cycle were detected by flow cytometry. The expression of autophagy related proteins was determined by Western blot. MG-132 inhibited cell proliferation, induced cell death and cell cycle arrest at G(2)/M phase, and activated autophagy in SHG-44 glioma cells. The expression of autophagy-related Beclin-1 and LC3-I was significantly up-regulated and part of LC3-I was converted into LC3-II. However, when SHG-44 glioma cells were co-treated with MG-132 and 3-MA, the cells became less viable, but cell death and cell numbers at G(2)/M phase increased. Moreover, the accumulation of acidic vesicular organelles was decreased, the expression of Beclin-1 and LC3 was significantly down-regulated and the conversion of LC3-II from LC3-I was also inhibited. Inhibition of the proteasome can induce autophagy in human SHG-44 glioma cells, and inhibition of autophagy increases cell death. This discovery may shed new light on the effect of autophagy on modulating the fate of SHG-44 glioma cells.Acta Pharmacologica Sinica (2009) 30: 1046-1052; doi: 10.1038/aps.2009.71.

  12. Zebrafish hair cell mechanics and physiology through the lens of noise-induced hair cell death

    Science.gov (United States)

    Coffin, Allison B.; Xu, Jie; Uribe, Phillip M.

    2018-05-01

    Hair cells are exquisitely sensitive to auditory stimuli, but also to damage from a variety of sources including noise trauma and ototoxic drugs. Mammals cannot regenerate cochlear hair cells, while non-mammalian vertebrates exhibit robust regenerative capacity. Our research group uses the lateral line system of larval zebrafish to explore the mechanisms underlying hair cell damage, identify protective therapies, and determine molecular drivers of innate regeneration. The lateral line system contains externally located sensory organs called neuromasts, each composed of ˜8-20 hair cells. Lateral line hair cells are homologous to vertebrate inner ear hair cells and share similar susceptibility to ototoxic damage. In the last decade, the lateral line has emerged as a powerful model system for understanding hair cell death mechanisms and for identifying novel protective compounds. Here we demonstrate that the lateral line is a tractable model for noise-induced hair cell death. We have developed a novel noise damage system capable of inducing over 50% loss of lateral line hair cells, with hair cell death occurring in a dose- and time-dependent manner. Cell death is greatest 72 hours post-exposure. However, early signs of hair cell damage, including changes in membrane integrity and reduced mechanotransduction, are apparent within hours of noise exposure. These features, early signs of damage followed by delayed hair cell death, are consistent with mammalian data, suggesting that noise acts similarly on zebrafish and mammalian hair cells. In our future work we will use our new model system to investigate noise damage events in real time, and to develop protective therapies for future translational research.

  13. Is radiation-induced cell death in mouse testis apoptosis?

    International Nuclear Information System (INIS)

    Hasegawa, Masatoshi; Wilson, Gene; Yun Zhang; Russell, Lonnie D.; Meistrich, Marvin L.

    1996-01-01

    Purpose: Radiation-induced death of spermatogonia and other germ cells in the testis has been claimed to be by an apoptotic mechanism, but these processes have been incompletely characterized. We investigated irradiated mouse testis by multiple techniques to determine whether the mode of cell death of spermatogonia can be classified as apoptosis. Materials and Methods: Adult male C57BL/6 and p53 knockout mice were irradiated with single doses of 0.5, 2.5 or 5.0 Gy. Four, 6, 8, 12, 18 or 24 hours after irradiation, testes were fixed in Bouin's solution or in 10% formalin. Slides were stained with hematoxylin and eosin or TdT-mediated dUTP-biotin nick end labeling (TUNEL). Some testes were perfusion-fixed with 5% glutaraldehyde for electron microscopy. Gel electrophoresis of DNA was also performed to identify DNA fragmentation. The number of sperm heads was counted 29 days after irradiation to evaluate the effect of radiation on the eventual survival of the differentiated spermatogonia. Results: The earliest sign of histological damage was an increase in the numbers of abnormal spermatogonia in the seminiferous tubules, particularly in stage I-VI of the seminiferous epithelial cycle. The numbers of abnormal spermatogonia began to increase at 6 hours, reached a peak 12 hours after irradiation, and then declined. The total number of spermatogonia began to decrease at 12 hours after irradiation, resulting in a 60% decline in sperm produced 29 days after 0.5 Gy. Although changes were greatest following 5.0 Gy irradiation, even 0.5 Gy induced marked changes. However, these changes were not induced in p53 knockout mice. By both light and electron microscopy, spermatogonia showed some condensation of nuclear chromatin, but margination of chromatin with clear delineation and nuclear fragmentation was rare. Many of the abnormal spermatogonia showed a positive TUNEL reaction, which was also at a maximum at 12 hours after irradiation. In addition, some TUNEL-positive and

  14. Photodynamic Efficiency: From Molecular Photochemistry to Cell Death

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    Isabel O. L. Bacellar

    2015-08-01

    Full Text Available Photodynamic therapy (PDT is a clinical modality used to treat cancer and infectious diseases. The main agent is the photosensitizer (PS, which is excited by light and converted to a triplet excited state. This latter species leads to the formation of singlet oxygen and radicals that oxidize biomolecules. The main motivation for this review is to suggest alternatives for achieving high-efficiency PDT protocols, by taking advantage of knowledge on the chemical and biological processes taking place during and after photosensitization. We defend that in order to obtain specific mechanisms of cell death and maximize PDT efficiency, PSes should oxidize specific molecular targets. We consider the role of subcellular localization, how PS photochemistry and photophysics can change according to its nanoenvironment, and how can all these trigger specific cell death mechanisms. We propose that in order to develop PSes that will cause a breakthrough enhancement in the efficiency of PDT, researchers should first consider tissue and intracellular localization, instead of trying to maximize singlet oxygen quantum yields in in vitro tests. In addition to this, we also indicate many open questions and challenges remaining in this field, hoping to encourage future research.

  15. Programmed cell death in periodontitis: recent advances and future perspectives.

    Science.gov (United States)

    Song, B; Zhou, T; Yang, W L; Liu, J; Shao, L Q

    2017-07-01

    Periodontitis is a highly prevalent infectious disease, characterized by destruction of the periodontium, and is the main cause of tooth loss. Periodontitis is initiated by periodontal pathogens, while other risk factors including smoking, stress, and systemic diseases aggravate its progression. Periodontitis affects many people worldwide, but the molecular mechanisms by which pathogens and risk factors destroy the periodontium are unclear. Programmed cell death (PCD), different from necrosis, is an active cell death mediated by a cascade of gene expression events and can be mainly classified into apoptosis, autophagy, necroptosis, and pyroptosis. Although PCD is involved in many inflammatory diseases, its correlation with periodontitis is unclear. After reviewing the relevant published articles, we found that apoptosis has indeed been reported to play a role in periodontitis. However, the role of autophagy in periodontitis needs further verification. Additionally, implication of necroptosis or pyroptosis in periodontitis remains unknown. Therefore, we recommend future studies, which will unravel the pivotal role of PCD in periodontitis, allowing us to prevent, diagnose, and treat the disease, as well as predict its outcomes. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  16. Mechanisms of palmitate-induced cell death in human osteoblasts

    Science.gov (United States)

    Gunaratnam, Krishanthi; Vidal, Christopher; Boadle, Ross; Thekkedam, Chris; Duque, Gustavo

    2013-01-01

    Summary Lipotoxicity is an overload of lipids in non-adipose tissues that affects function and induces cell death. Lipotoxicity has been demonstrated in bone cells in vitro using osteoblasts and adipocytes in coculture. In this condition, lipotoxicity was induced by high levels of saturated fatty acids (mostly palmitate) secreted by cultured adipocytes acting in a paracrine manner. In the present study, we aimed to identify the underlying mechanisms of lipotoxicity in human osteoblasts. Palmitate induced autophagy in cultured osteoblasts, which was preceded by the activation of autophagosomes that surround palmitate droplets. Palmitate also induced apoptosis though the activation of the Fas/Jun kinase (JNK) apoptotic pathway. In addition, osteoblasts could be protected from lipotoxicity by inhibiting autophagy with the phosphoinositide kinase inhibitor 3-methyladenine or by inhibiting apoptosis with the JNK inhibitor SP600125. In summary, we have identified two major molecular mechanisms of lipotoxicity in osteoblasts and in doing so we have identified a new potential therapeutic approach to prevent osteoblast dysfunction and death, which are common features of age-related bone loss and osteoporosis. PMID:24285710

  17. Effects of epigallocatechin gallate on ultra-violet-induced cell death in PC12 cells

    International Nuclear Information System (INIS)

    Takahashi, Hideo; Seki, Sakiko; Sakamoto, Naotaka; Nakagawa, Shigeki

    2002-01-01

    We examined the effects of catechin on ultra-violet-induced cell death in PC12 cells. PC12 cells were irradiated by ultra-violet C (254 nm) (UVC). We found that the lactate dehydrogenase (LDH) activities in culture media and lipid peroxide in PC12 cells, which indicate cell death and cell membrane damage, respectively, were increased by UVC irradiation in a time-dependent manner. Cell death was gradually stimulated for 9 hours of cultivation after a UVC irradiation period of 10 or 30 min. Epigallocatechin gallate (EGCG), which is one of the main catechins found in green tea, suppressed the increase in LDH activity in culture medium and also inhibited the formation of lipid peroxide. IκB, a member of the cell death signaling system, was phosphorylated at 1 hour after 10 min of UVC irradiation. Stimulation of phosphorylation of IκB by UVC was suppressed by the addition of EGCG. We concluded that EGCG protects the PC12 cell from cell damage caused by UVC irradiation. (author)

  18. DRAM Triggers Lysosomal Membrane Permeabilization and Cell Death in CD4+ T Cells Infected with HIV

    Science.gov (United States)

    Laforge, Mireille; Limou, Sophie; Harper, Francis; Casartelli, Nicoletta; Rodrigues, Vasco; Silvestre, Ricardo; Haloui, Houda; Zagury, Jean-Francois; Senik, Anna; Estaquier, Jerome

    2013-01-01

    Productive HIV infection of CD4+ T cells leads to a caspase-independent cell death pathway associated with lysosomal membrane permeabilization (LMP) and cathepsin release, resulting in mitochondrial outer membrane permeabilization (MOMP). Herein, we demonstrate that HIV infection induces damage-regulated autophagy modulator (DRAM) expression in a p53-dependent manner. Knocking down the expression of DRAM and p53 genes with specific siRNAs inhibited autophagy and LMP. However, inhibition of Atg5 and Beclin genes that prevents autophagy had a minor effect on LMP and cell death. The knock down of DRAM gene inhibited cytochrome C release, MOMP and cell death. However, knocking down DRAM, we increased viral infection and production. Our study shows for the first time the involvement of DRAM in host-pathogen interactions, which may represent a mechanism of defense via the elimination of infected cells. PMID:23658518

  19. DRAM triggers lysosomal membrane permeabilization and cell death in CD4(+ T cells infected with HIV.

    Directory of Open Access Journals (Sweden)

    Mireille Laforge

    Full Text Available Productive HIV infection of CD4(+ T cells leads to a caspase-independent cell death pathway associated with lysosomal membrane permeabilization (LMP and cathepsin release, resulting in mitochondrial outer membrane permeabilization (MOMP. Herein, we demonstrate that HIV infection induces damage-regulated autophagy modulator (DRAM expression in a p53-dependent manner. Knocking down the expression of DRAM and p53 genes with specific siRNAs inhibited autophagy and LMP. However, inhibition of Atg5 and Beclin genes that prevents autophagy had a minor effect on LMP and cell death. The knock down of DRAM gene inhibited cytochrome C release, MOMP and cell death. However, knocking down DRAM, we increased viral infection and production. Our study shows for the first time the involvement of DRAM in host-pathogen interactions, which may represent a mechanism of defense via the elimination of infected cells.

  20. An extensive microarray analysis of AAL-toxin-induced cell death in Arabidopsis thaliana brings new insights into the complexity of programmed cell death in plants

    NARCIS (Netherlands)

    Gechev, T.S.; Gadjev, I.Z.; Hille, J.

    2004-01-01

    A T-DNA knockout of the Arabidopsis homologue of the tomato disease resistance gene Asc was obtained. The asc gene renders plants sensitive to programmed cell death (PCD) triggered by the fungal AAL toxin. To obtain more insights into the nature of AAL-toxin-induced cell death and to identify genes

  1. Maitotoxin-induced liver cell death involving loss of cell ATP following influx of calcium

    International Nuclear Information System (INIS)

    Kutty, R.K.; Singh, Y.; Santostasi, G.; Krishna, G.

    1989-01-01

    Maitotoxin, one of the most potent marine toxins known, produced cell death in cultures of rat hepatocytes with a TD50 of 80 pM at 24 hr. The cell death, as indicated by a dose- and time-dependent leakage of lactate dehydrogenase (LDH), was also associated with the leakage of [14C]adenine nucleotides from hepatocytes prelabeled with [14C]-adenine. The toxic effect of maitotoxin was completely abolished by the omission of calcium from the culture medium. The cell death induced by maitotoxin increased with increasing concentrations of calcium in the medium. Treatment of hepatocytes with low concentrations of the toxin (less than 0.5 ng/ml) resulted in increases in 45Ca influx into the cells. At higher concentrations of maitotoxin (greater than 1ng/ml), the initial increase in 45Ca influx was followed by the release of the 45Ca from the cells into the medium. Since the 45Ca release paralleled the LDH leakage, the release of calcium was due to cell death. The 45Ca influx, [14C]adenine nucleotide leakage, and LDH leakage were effectively inhibited by verapamil, a calcium channel blocker. Maitotoxin also induced a time- and dose-dependent loss of ATP from hepatocytes, which preceded the [14C]adenine nucleotide and LDH leakage. Thus, it appears that the cell death resulting from maitotoxin treatment is caused by the elevated intracellular calcium, which in turn inhibits mitochondrial oxidative phosphorylation causing depletion of cell ATP. Loss of cell ATP may be the causative event in the maitotoxin-induced cell death

  2. Taxifolin synergizes Andrographolide-induced cell death by attenuation of autophagy and augmentation of caspase dependent and independent cell death in HeLa cells.

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    Mazen Alzaharna

    Full Text Available Andrographolide (Andro has emerged recently as a potential and effective anticancer agent with induction of apoptosis in some cancer cell lines while induction of G2/M arrest with weak apoptosis in others. Few studies have proved that Andro is also effective in combination therapy. The flavonoid Taxifolin (Taxi has showed anti-oxidant and antiproliferative effects against different cancer cells. Therefore, the present study investigated the cytotoxic effects of Andro alone or in combination with Taxi on HeLa cells. The combination of Andro with Taxi was synergistic at all tested concentrations and combination ratios. Andro alone induced caspase-dependent apoptosis which was enhanced by the combination with Taxi and attenuated partly by using Z-Vad-Fmk. Andro induced a protective reactive oxygen species (ROS-dependent autophagy which was attenuated by Taxi. The activation of p53 was involved in Andro-induced autophagy where the use of Taxi or pifithrin-α (PFT-α decreased it while the activation of JNK was involved in the cell death of HeLa cells but not in the induction of autophagy. The mitochondrial outer-membrane permeabilization (MOMP plays an important role in Andro-induced cell death in HeLa cells. Andro alone increased the MOMP which was further increased in the case of combination. This led to the increase in AIF and cytochrome c release from mitochondria which consequently increased caspase-dependent and independent cell death. In conclusion, Andro induced a protective autophagy in HeLa cells which was reduced by Taxi and the cell death was increased by increasing the MOMP and subsequently the caspase-dependent and independent cell death.

  3. Taxifolin synergizes Andrographolide-induced cell death by attenuation of autophagy and augmentation of caspase dependent and independent cell death in HeLa cells

    Science.gov (United States)

    Alzaharna, Mazen; Alqouqa, Iyad; Cheung, Hon-Yeung

    2017-01-01

    Andrographolide (Andro) has emerged recently as a potential and effective anticancer agent with induction of apoptosis in some cancer cell lines while induction of G2/M arrest with weak apoptosis in others. Few studies have proved that Andro is also effective in combination therapy. The flavonoid Taxifolin (Taxi) has showed anti-oxidant and antiproliferative effects against different cancer cells. Therefore, the present study investigated the cytotoxic effects of Andro alone or in combination with Taxi on HeLa cells. The combination of Andro with Taxi was synergistic at all tested concentrations and combination ratios. Andro alone induced caspase-dependent apoptosis which was enhanced by the combination with Taxi and attenuated partly by using Z-Vad-Fmk. Andro induced a protective reactive oxygen species (ROS)-dependent autophagy which was attenuated by Taxi. The activation of p53 was involved in Andro-induced autophagy where the use of Taxi or pifithrin-α (PFT-α) decreased it while the activation of JNK was involved in the cell death of HeLa cells but not in the induction of autophagy. The mitochondrial outer-membrane permeabilization (MOMP) plays an important role in Andro-induced cell death in HeLa cells. Andro alone increased the MOMP which was further increased in the case of combination. This led to the increase in AIF and cytochrome c release from mitochondria which consequently increased caspase-dependent and independent cell death. In conclusion, Andro induced a protective autophagy in HeLa cells which was reduced by Taxi and the cell death was increased by increasing the MOMP and subsequently the caspase-dependent and independent cell death. PMID:28182713

  4. Blockade of the ERK pathway markedly sensitizes tumor cells to HDAC inhibitor-induced cell death

    International Nuclear Information System (INIS)

    Ozaki, Kei-ichi; Minoda, Ai; Kishikawa, Futaba; Kohno, Michiaki

    2006-01-01

    Constitutive activation of the extracellular signal-regulated kinase (ERK) pathway is associated with the neoplastic phenotype of a large number of human tumor cells. Although specific blockade of the ERK pathway by treating such tumor cells with potent mitogen-activated protein kinase/ERK kinase (MEK) inhibitors completely suppresses their proliferation, it by itself shows only a modest effect on the induction of apoptotic cell death. However, these MEK inhibitors markedly enhance the efficacy of histone deacetylase (HDAC) inhibitors to induce apoptotic cell death: such an enhanced cell death is observed only in tumor cells in which the ERK pathway is constitutively activated. Co-administration of MEK inhibitor markedly sensitizes tumor cells to HDAC inhibitor-induced generation of reactive oxygen species, which appears to mediate the enhanced cell death induced by the combination of these agents. These results suggest that the combination of MEK inhibitors and HDAC inhibitors provides an efficient chemotherapeutic strategy for the treatment of tumor cells in which the ERK pathway is constitutively activated

  5. The calcimimetic R-568 induces apoptotic cell death in prostate cancer cells

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    Cheng Guangming

    2009-07-01

    Full Text Available Abstract Background Increased serum level of parathyroid hormone (PTH was found in metastatic prostate cancers. Calcimimetic R-568 was reported to reduce PTH expression, to suppress cell proliferation and to induce apoptosis in parathyroid cells. In this study, we investigated the effect of R-568 on cellular survival of prostate cancer cells. Methods Prostate cancer cell lines LNCaP and PC-3 were used in this study. Cellular survival was determined with MTT, trypan blue exclusion and fluorescent Live/Death assays. Western blot assay was utilized to assess apoptotic events induced by R-568 treatment. JC-1 staining was used to evaluate mitochondrial membrane potential. Results In cultured prostate cancer LNCaP and PC-3 cells, R-568 treatment significantly reduced cellular survival in a dose- and time-dependent manner. R-568-induced cell death was an apoptotic event, as evidenced by caspase-3 processing and PARP cleavage, as well as JC-1 color change in mitochondria. Knocking down calcium sensing receptor (CaSR significantly reduced R-568-induced cytotoxicity. Enforced expression of Bcl-xL gene abolished R-568-induced cell death, while loss of Bcl-xL expression led to increased cell death in R-568-treated LNCaP cells,. Conclusion Taken together, our data demonstrated that calcimimetic R-568 triggers an intrinsic mitochondria-related apoptotic pathway, which is dependent on the CaSR and is modulated by Bcl-xL anti-apoptotic pathway.

  6. Morphologic categorization of cell death induced by mild hyperthermia and comparison with death induced by ionizing radiation and cytotoxic drugs

    International Nuclear Information System (INIS)

    Allan, D.J.; Harmon, B.V.

    1986-01-01

    This paper presents a summary of the morphological categorization of cell death, results of two in vivo studies on the cell death induced by mild hyperthermia in rat small intestine and mouse mastocytoma, and a comparison of the cell death induced by hyperthermia, radiation and cytotoxic drugs. Two distinct forms of cell death, apoptosis and necrosis, can be recognized on morphologic grounds. Apoptosis appears to be a process of active cellular self-destruction to which a biologically meaningful role can usually be attributed, whereas necrosis is a passive degenerative phenomenon that results from irreversible cellular injury. Light and transmission electron microscopic studies showed that lower body hyperthermia (43 degrees C for 30 min) induced only apoptosis of intestinal epithelial cells, and of lymphocytes, plasma cells, and eosinophils. In the mastocytoma, hyperthermia (43 degrees C for 15 min) produced widespread tumor necrosis and also enhanced apoptosis of tumor cells. Ionizing radiation and cytotoxic drugs are also known to induce apoptosis in a variety of tissues. It is attractive to speculate that DNA damage by each agent is the common event which triggers the same process of active cellular self-destruction that characteristically effects selective cell deletion in normal tissue homeostasis

  7. Type I collagen gel protects murine fibrosarcoma L929 cells from TNFα-induced cell death

    International Nuclear Information System (INIS)

    Wang, Hong-Ju; He, Wen-Qi; Chen, Ling; Liu, Wei-Wei; Xu, Qian; Xia, Ming-Yu; Hayashi, Toshihiko; Fujisaki, Hitomi; Hattori, Shunji; Tashiro, Shin-ichi; Onodera, Satoshi; Ikejima, Takashi

    2015-01-01

    Murine fibrosarcoma L929 cells have been used to test efficacy of proinflammatory cytokine TNFα. In the present study, we reported on protective effect of type I collagen gel used as L929 cell culture. L929 cell grew and proliferated well on collagen gel. However, the L929 cells exhibited cobblestone-like morphology which was much different from the spread fusiform shape when cultured on conventional cell dishes as well as the cells tended to aggregate. On conventional cell culture dishes, the cells treated with TNFα became round in shape and eventually died in a necroptotic manner. The cells cultured on collagen gel, however, were completely unaffected. TNFα treatment was reported to induce autophagy in L929 cells on the plastic dish, and therefore we investigated the effect of collagen gel on induction of autophagy. The results indicated that autophagy induced by TNFα treatment was much reduced when the cells were cultured on collagen gel. In conclusion, type I collagen gel protected L929 cell from TNFα-induced cell death. - Highlights: • Collagen gel culture changed the morphology of L929 cells. • L929 cell cultured on collagen gel were resistant to TNFα-induced cell death. • Collagen gel culture inhibited TNFα-induced autophagy in L929 cells

  8. Type I collagen gel protects murine fibrosarcoma L929 cells from TNFα-induced cell death

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hong-Ju; He, Wen-Qi; Chen, Ling; Liu, Wei-Wei; Xu, Qian; Xia, Ming-Yu; Hayashi, Toshihiko [China-Japan Research Institute of Medical and Pharmaceutical Sciences, Shenyang Pharmaceutical University, Shenyang 110016 (China); Fujisaki, Hitomi; Hattori, Shunji [Nippi Research Institute of Biomatrix, Toride, Ibaraki 302-0017 (Japan); Tashiro, Shin-ichi [Institute for Clinical and Biomedical Sciences, Kyoto 603-8072 (Japan); Onodera, Satoshi [Department of Clinical and Pharmaceutical Sciences, Showa Pharmaceutical University, Tokyo 194-8543 (Japan); Ikejima, Takashi, E-mail: ikejimat@vip.sina.com [China-Japan Research Institute of Medical and Pharmaceutical Sciences, Shenyang Pharmaceutical University, Shenyang 110016 (China)

    2015-02-20

    Murine fibrosarcoma L929 cells have been used to test efficacy of proinflammatory cytokine TNFα. In the present study, we reported on protective effect of type I collagen gel used as L929 cell culture. L929 cell grew and proliferated well on collagen gel. However, the L929 cells exhibited cobblestone-like morphology which was much different from the spread fusiform shape when cultured on conventional cell dishes as well as the cells tended to aggregate. On conventional cell culture dishes, the cells treated with TNFα became round in shape and eventually died in a necroptotic manner. The cells cultured on collagen gel, however, were completely unaffected. TNFα treatment was reported to induce autophagy in L929 cells on the plastic dish, and therefore we investigated the effect of collagen gel on induction of autophagy. The results indicated that autophagy induced by TNFα treatment was much reduced when the cells were cultured on collagen gel. In conclusion, type I collagen gel protected L929 cell from TNFα-induced cell death. - Highlights: • Collagen gel culture changed the morphology of L929 cells. • L929 cell cultured on collagen gel were resistant to TNFα-induced cell death. • Collagen gel culture inhibited TNFα-induced autophagy in L929 cells.

  9. GPNMB ameliorates mutant TDP-43-induced motor neuron cell death.

    Science.gov (United States)

    Nagahara, Yuki; Shimazawa, Masamitsu; Ohuchi, Kazuki; Ito, Junko; Takahashi, Hitoshi; Tsuruma, Kazuhiro; Kakita, Akiyoshi; Hara, Hideaki

    2017-08-01

    Glycoprotein nonmetastatic melanoma protein B (GPNMB) aggregates are observed in the spinal cord of amyotrophic lateral sclerosis (ALS) patients, but the detailed localization is still unclear. Mutations of transactive response DNA binding protein 43kDa (TDP-43) are associated with neurodegenerative diseases including ALS. In this study, we evaluated the localization of GPNMB aggregates in the spinal cord of ALS patients and the effect of GPNMB against mutant TDP-43 induced motor neuron cell death. GPNMB aggregates were not localized in the glial fibrillary acidic protein (GFAP)-positive astrocyte and ionized calcium binding adaptor molecule-1 (Iba1)-positive microglia. GPNMB aggregates were localized in the microtubule-associated protein 2 (MAP-2)-positive neuron and neurofilament H non-phosphorylated (SMI-32)-positive neuron, and these were co-localized with TDP-43 aggregates in the spinal cord of ALS patients. Mock or TDP-43 (WT, M337V, and A315T) plasmids were transfected into mouse motor neuron cells (NSC34). The expression level of GPNMB was increased by transfection of mutant TDP-43 plasmids. Recombinant GPNMB ameliorated motor neuron cell death induced by transfection of mutant TDP-43 plasmids and serum-free stress. Furthermore, the expression of phosphorylated ERK1/2 and phosphorylated Akt were decreased by this stress, and these expressions were increased by recombinant GPNMB. These results indicate that GPNMB has protective effects against mutant TDP-43 stress via activating the ERK1/2 and Akt pathways, and GPNMB may be a therapeutic target for TDP-43 proteinopathy in familial and sporadic ALS. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  10. A role for programmed cell death in the microbial loop.

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    Mónica V Orellana

    Full Text Available The microbial loop is the conventional model by which nutrients and minerals are recycled in aquatic eco-systems. Biochemical pathways in different organisms become metabolically inter-connected such that nutrients are utilized, processed, released and re-utilized by others. The result is that unrelated individuals end up impacting each others' fitness directly through their metabolic activities. This study focused on the impact of programmed cell death (PCD on a population's growth as well as its role in the exchange of carbon between two naturally co-occurring halophilic organisms. Flow cytometric, biochemical, ¹⁴C radioisotope tracing assays, and global transcriptomic analyses show that organic algal photosynthate released by Dunalliela salina cells undergoing PCD complements the nutritional needs of other non-PCD D. salina cells. This occurs in vitro in a carbon limited environment and enhances the growth of the population. In addition, a co-occurring heterotroph Halobacterium salinarum re-mineralizes the carbon providing elemental nutrients for the mixoheterotrophic chlorophyte. The significance of this is uncertain and the archaeon can also subsist entirely on the lysate of apoptotic algae. PCD is now well established in unicellular organisms; however its ecological relevance has been difficult to decipher. In this study we found that PCD in D. salina causes the release of organic nutrients such as glycerol, which can be used by others in the population as well as a co-occurring halophilic archaeon. H. salinarum also re-mineralizes the dissolved material promoting algal growth. PCD in D. salina was the mechanism for the flow of dissolved photosynthate between unrelated organisms. Ironically, programmed death plays a central role in an organism's own population growth and in the exchange of nutrients in the microbial loop.

  11. Oxidative Stress, Redox Signaling, and Autophagy: Cell Death Versus Survival

    Science.gov (United States)

    Navarro-Yepes, Juliana; Burns, Michaela; Anandhan, Annadurai; Khalimonchuk, Oleh; del Razo, Luz Maria; Quintanilla-Vega, Betzabet; Pappa, Aglaia; Panayiotidis, Mihalis I.

    2014-01-01

    Abstract Significance: The molecular machinery regulating autophagy has started becoming elucidated, and a number of studies have undertaken the task to determine the role of autophagy in cell fate determination within the context of human disease progression. Oxidative stress and redox signaling are also largely involved in the etiology of human diseases, where both survival and cell death signaling cascades have been reported to be modulated by reactive oxygen species (ROS) and reactive nitrogen species (RNS). Recent Advances: To date, there is a good understanding of the signaling events regulating autophagy, as well as the signaling processes by which alterations in redox homeostasis are transduced to the activation/regulation of signaling cascades. However, very little is known about the molecular events linking them to the regulation of autophagy. This lack of information has hampered the understanding of the role of oxidative stress and autophagy in human disease progression. Critical Issues: In this review, we will focus on (i) the molecular mechanism by which ROS/RNS generation, redox signaling, and/or oxidative stress/damage alter autophagic flux rates; (ii) the role of autophagy as a cell death process or survival mechanism in response to oxidative stress; and (iii) alternative mechanisms by which autophagy-related signaling regulate mitochondrial function and antioxidant response. Future Directions: Our research efforts should now focus on understanding the molecular basis of events by which autophagy is fine tuned by oxidation/reduction events. This knowledge will enable us to understand the mechanisms by which oxidative stress and autophagy regulate human diseases such as cancer and neurodegenerative disorders. Antioxid. Redox Signal. 21, 66–85. PMID:24483238

  12. Mechanisms of Ionizing Radiation-Induced Cell Death in Primary Lung Cells

    Science.gov (United States)

    2013-03-05

    lose their capacity to replicate after a certain number       10 of passages. This finite number was termed the “ Hayflick limit ” and cells...Upstream and downstream of mTOR. Genes & development 18:1926-45 78. Hayflick L. 1965. The Limited in Vitro Lifetime of Human Diploid Cell Strains...can lead to death. During the course of radiotherapy, the use of IR for the treatment of thoracic cancers is limited by IR-induced cell death to the

  13. Cell-Centric View of Apoptosis and Apoptotic Cell Death-Inducing Antitumoral Strategies

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    Maria Dolores Boyano

    2011-03-01

    Full Text Available Programmed cell death and especially apoptotic cell death, occurs under physiological conditions and is also desirable under pathological circumstances. However, the more we learn about cellular signaling cascades, the less plausible it becomes to find restricted and well-limited signaling pathways. In this context, an extensive description of pathway-connections is necessary in order to point out the main regulatory molecules as well as to select the most appropriate therapeutic targets. On the other hand, irregularities in programmed cell death pathways often lead to tumor development and cancer-related mortality is projected to continue increasing despite the effort to develop more active and selective antitumoral compounds. In fact, tumor cell plasticity represents a major challenge in chemotherapy and improvement on anticancer therapies seems to rely on appropriate drug combinations. An overview of the current status regarding apoptotic pathways as well as available chemotherapeutic compounds provides a new perspective of possible future anticancer strategies.

  14. Increasing RpoS expression causes cell death in Borrelia burgdorferi.

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    Linxu Chen

    Full Text Available RpoS, one of the two alternative σ factors in Borrelia burgdorferi, is tightly controlled by multiple regulators and, in turn, determines expression of many critical virulence factors. Here we show that increasing RpoS expression causes cell death. The immediate effect of increasing RpoS expression was to promote bacterial division and as a consequence result in a rapid increase in cell number before causing bacterial death. No DNA fragmentation or degradation was observed during this induced cell death. Cryo-electron microscopy showed induced cells first formed blebs, which were eventually released from dying cells. Apparently blebbing initiated cell disintegration leading to cell death. These findings led us to hypothesize that increasing RpoS expression triggers intracellular programs and/or pathways that cause spirochete death. The potential biological significance of induced cell death may help B. burgdorferi regulate its population to maintain its life cycle in nature.

  15. HAMLET (human alpha-lactalbumin made lethal to tumor cells) triggers autophagic tumor cell death.

    Science.gov (United States)

    Aits, Sonja; Gustafsson, Lotta; Hallgren, Oskar; Brest, Patrick; Gustafsson, Mattias; Trulsson, Maria; Mossberg, Ann-Kristin; Simon, Hans-Uwe; Mograbi, Baharia; Svanborg, Catharina

    2009-03-01

    HAMLET, a complex of partially unfolded alpha-lactalbumin and oleic acid, kills a wide range of tumor cells. Here we propose that HAMLET causes macroautophagy in tumor cells and that this contributes to their death. Cell death was accompanied by mitochondrial damage and a reduction in the level of active mTOR and HAMLET triggered extensive cytoplasmic vacuolization and the formation of double-membrane-enclosed vesicles typical of macroautophagy. In addition, HAMLET caused a change from uniform (LC3-I) to granular (LC3-II) staining in LC3-GFP-transfected cells reflecting LC3 translocation during macroautophagy, and this was blocked by the macroautophagy inhibitor 3-methyladenine. HAMLET also caused accumulation of LC3-II detected by Western blot when lysosomal degradation was inhibited suggesting that HAMLET caused an increase in autophagic flux. To determine if macroautophagy contributed to cell death, we used RNA interference against Beclin-1 and Atg5. Suppression of Beclin-1 and Atg5 improved the survival of HAMLET-treated tumor cells and inhibited the increase in granular LC3-GFP staining. The results show that HAMLET triggers macroautophagy in tumor cells and suggest that macroautophagy contributes to HAMLET-induced tumor cell death.

  16. Fas/Fas ligand regulation mediates cell death in human Ewing's sarcoma cells treated with melatonin

    Science.gov (United States)

    García-Santos, G; Martin, V; Rodríguez-Blanco, J; Herrera, F; Casado-Zapico, S; Sánchez-Sánchez, A M; Antolín, I; Rodríguez, C

    2012-01-01

    Background: Despite recent advances in cancer therapy, the 5-year survival rate for Ewing's sarcoma is still very low, and new therapeutic approaches are necessary. It was found previously that melatonin induces cell death in the Ewing's sarcoma cell line, SK-N-MC, by activating the extrinsic apoptotic pathway. Methods: Melatonin actions were analysed by metabolic viability/survival cell assays, flow cytometry, quantitative PCR for mRNA expression, western blot for protein activation/expression and electrophoretic mobility shift assay for transcription factor activation. Results: Melatonin increases the expression of Fas and its ligand Fas L, this increase being responsible for cell death induced by the indolamine. Melatonin also produces a transient increase in intracellular oxidants and activation of the redox-regulated transcription factor Nuclear factor-kappaB. Inhibition of such activation prevents cell death and Fas/Fas L upregulation. Cytotoxic effect and Fas/Fas L regulation occur in all Ewing's cell lines studied, and do not occur in the other tumour cell lines studied where melatonin does not induce cell death. Conclusion: Our data offers new insights in the study of alternative therapeutic strategies in the treatment of Ewing's sarcoma. Further attention deserves to be given to the differences in the cellular biology of sensitive tumours that could explain the cytotoxic effect of melatonin and the increase in the level of free radicals caused by this molecule, in particular cancer types. PMID:22382690

  17. Induction of cell death by graphene in Arabidopsis thaliana (Columbia ecotype) T87 cell suspensions

    International Nuclear Information System (INIS)

    Begum, Parvin; Fugetsu, Bunshi

    2013-01-01

    Highlights: • This study was set up to explore potential influence of graphene on T87 cells. • Fragmented nuclei, membrane damage, mitochondrial dysfunction were observed. • ROS increased, ROS are key mediators in the cell death signaling pathway. • Translocation of graphene into cells and an endocytosis-like structure was observed. • Graphene entering into the cells by endocytosis. -- Abstract: The toxicity of graphene on suspensions of Arabidopsis thaliana (Columbia ecotype) T87 cells was investigated by examining the morphology, mitochondrial dysfunction, reactive oxygen species generation (ROS), and translocation of graphene as the toxicological endpoints. The cells were grown in Jouanneau and Péaud-Lenoel (JPL) media and exposed to graphene at concentrations 0–80 mg/L. Morphological changes were observed by scanning electron microscope and the adverse effects such as fragmented nuclei, membrane damage, mitochondrial dysfunction was observed with fluorescence microscopy by staining with Hoechst 33342/propidium iodide and succinate dehydrogenase (mitochondrial bioenergetic enzyme). Analysis of intracellular ROS by 2′,7′-dichlorofluorescein diacetate demonstrated that graphene induced a 3.3-fold increase in ROS, suggesting that ROS are key mediators in the cell death signaling pathway. Transmission electron microscopy verified the translocation of graphene into cells and an endocytosis-like structure was observed which suggested graphene entering into the cells by endocytosis. In conclusion, our results show that graphene induced cell death in T87 cells through mitochondrial damage mediated by ROS

  18. Ganglioside GD2 in reception and transduction of cell death signal in tumor cells

    International Nuclear Information System (INIS)

    Doronin, Igor I; Vishnyakova, Polina A; Kholodenko, Irina V; Ponomarev, Eugene D; Ryazantsev, Dmitry Y; Molotkovskaya, Irina M; Kholodenko, Roman V

    2014-01-01

    Ganglioside GD2 is expressed on plasma membranes of various types of malignant cells. One of the most promising approaches for cancer immunotherapy is the treatment with monoclonal antibodies recognizing tumor-associated markers such as ganglioside GD2. It is considered that major mechanisms of anticancer activity of anti-GD2 antibodies are complement-dependent cytotoxicity and/or antibody-mediated cellular cytotoxicity. At the same time, several studies suggested that anti-GD2 antibodies are capable of direct induction of cell death of number of tumor cell lines, but it has not been investigated in details. In this study we investigated the functional role of ganglioside GD2 in the induction of cell death of multiple tumor cell lines by using GD2-specific monoclonal antibodies. Expression of GD2 on different tumor cell lines was analyzed by flow cytometry using anti-GD2 antibodies. By using HPTLC followed by densitometric analysis we measured the amount of ganglioside GD2 in total ganglioside fractions isolated from tumor cell lines. An MTT assay was performed to assess viability of GD2-positive and -negative tumor cell lines treated with anti-GD2 mAbs. Cross-reactivity of anti-GD2 mAbs with other gangliosides or other surface molecules was investigated by ELISA and flow cytometry. Inhibition of GD2 expression was achieved by using of inhibitor for ganglioside synthesis PDMP and/or siRNA for GM2/GD2 and GD3 synthases. Anti-GD2 mAbs effectively induced non-classical cell death that combined features of both apoptosis and necrosis in GD2-positive tumor cells and did not affect GD2-negative tumors. Anti-GD2 mAbs directly induced cell death, which included alteration of mitochondrial membrane potential, induction of apoptotic volume decrease and cell membrane permeability. This cytotoxic effect was mediated exclusively by specific binding of anti-GD2 antibodies with ganglioside GD2 but not with other molecules. Moreover, the level of GD2 expression correlated with

  19. Melatonina: modulador de morte celular Melatonin: cell death modulator

    Directory of Open Access Journals (Sweden)

    Cecília da Silva Ferreira

    2010-01-01

    Full Text Available A apoptose ou morte programada é um fenômeno biológico essencial para o desenvolvimento e manutenção de uma população celular. Neste processo, as células senescentes ou indesejáveis são eliminadas após ativação de um programa de morte celular, que envolve a participação de moléculas pró-apoptóticas (Fas, FasL, Bax, Caspases 2, 3, 6, 7, 8 e 9. A ativação destas moléculas provoca típicas alterações morfológicas como a retração celular, perda de aderência à matriz extracelular e às células vizinhas, condensação da cromatina, fragmentação do DNA e formação de corpos apoptóticos. Moléculas antiapoptóticas (Bcl2, FLIP bloqueiam o surgimento e a evolução destas alterações celulares e evitam a morte celular. É o equilíbrio entre moléculas pró e antiapoptóticas que assegura a homeostase tecidual. O descontrole da apoptose pode contribuir para o aparecimento de diversas doenças neoplásicas, autoimunes e neurodegenerativas. Diversos agentes indutores e inibidores de apoptose são reconhecidos como armas potenciais no combate a doenças relacionadas a distúrbios de proliferação e morte celular, dentre eles, destacam-se os hormônios. A melatonina tem sido relatada com importante ação antiápoptótica em diversos tecidos, modulando a expressão de agentes, reduzindo a entrada de cálcio na célula, bem como atenuando a produção de espécies reativas de oxigênio e de proteínas pró-apoptóticas, tal como, diminuição da Bax. O conhecimento de novos agentes capazes de atuar nas vias da apoptose é de grande valia para o desenvolvimento de futuras terapias no tratamento de diversas doenças. Assim, o objetivo dessa revisão é elucidar os principais aspectos da morte celular pela apoptose e o papel da melatonina neste processo.Apoptosis or programmed death is a biological phenomenon, which is essential for the development and maintenance of a cell population. In this process, senescent or damaged

  20. On Programmed Cell Death in Plasmodium falciparum: Status Quo

    Directory of Open Access Journals (Sweden)

    Dewaldt Engelbrecht

    2012-01-01

    Full Text Available Conflicting arguments and results exist regarding the occurrence and phenotype of programmed cell death (PCD in the malaria parasite Plasmodium falciparum. Inconsistencies relate mainly to the number and type of PCD markers assessed and the different methodologies used in the studies. In this paper, we provide a comprehensive overview of the current state of knowledge and empirical evidence for PCD in the intraerythrocytic stages of P. falciparum. We consider possible reasons for discrepancies in the data and offer suggestions towards more standardised investigation methods in this field. Furthermore, we present genomic evidence for PCD machinery in P. falciparum. We discuss the potential adaptive or nonadaptive role of PCD in the parasite life cycle and its possible exploitation in the development of novel drug targets. Lastly, we pose pertinent unanswered questions concerning the PCD phenomenon in P. falciparum to provide future direction.

  1. On Programmed Cell Death in Plasmodium falciparum: Status Quo

    Science.gov (United States)

    Engelbrecht, Dewaldt; Durand, Pierre Marcel; Coetzer, Thérèsa Louise

    2012-01-01

    Conflicting arguments and results exist regarding the occurrence and phenotype of programmed cell death (PCD) in the malaria parasite Plasmodium falciparum. Inconsistencies relate mainly to the number and type of PCD markers assessed and the different methodologies used in the studies. In this paper, we provide a comprehensive overview of the current state of knowledge and empirical evidence for PCD in the intraerythrocytic stages of P. falciparum. We consider possible reasons for discrepancies in the data and offer suggestions towards more standardised investigation methods in this field. Furthermore, we present genomic evidence for PCD machinery in P. falciparum. We discuss the potential adaptive or nonadaptive role of PCD in the parasite life cycle and its possible exploitation in the development of novel drug targets. Lastly, we pose pertinent unanswered questions concerning the PCD phenomenon in P. falciparum to provide future direction. PMID:22287973

  2. Programmed cell death in trypanosomatids and other unicellular organisms.

    Science.gov (United States)

    Debrabant, Alain; Lee, Nancy; Bertholet, Sylvie; Duncan, Robert; Nakhasi, Hira L

    2003-03-01

    In multicellular organisms, cellular growth and development can be controlled by programmed cell death (PCD), which is defined by a sequence of regulated events. However, PCD is thought to have evolved not only to regulate growth and development in multicellular organisms but also to have a functional role in the biology of unicellular organisms. In protozoan parasites and in other unicellular organisms, features of PCD similar to those in multicellular organisms have been reported, suggesting some commonality in the PCD pathway between unicellular and multicellular organisms. However, more extensive studies are needed to fully characterise the PCD pathway and to define the factors that control PCD in the unicellular organisms. The understanding of the PCD pathway in unicellular organisms could delineate the evolutionary origin of this pathway. Further characterisation of the PCD pathway in the unicellular parasites could provide information regarding their pathogenesis, which could be exploited to target new drugs to limit their growth and treat the disease they cause.

  3. The use of computerized video time lapse to study cell death in rat embryo cells transfected with c-ha-ras or c-myc

    International Nuclear Information System (INIS)

    Forrester, H.B.; Vidair, C.A.; Dewey, W.C.; Ling, C.C.

    1998-01-01

    Full text: Individual rat embryo fibroblasts that had been transfected with the c-myc (REC:myc) or c-Ha ras (REC:ras) oncogene were followed after irradiation using a computer video time lapse (CVTL) system in order to quantify the lethal events that resulted in loss of clonogenic survival after irradiation. By followed the cells for 2 to 3 generations before irradiation we were able to determine where they were in the cell cycle at the time of irradiation for cell cycle analysis. After irradiation, the individual cells and their progeny were followed in multiple fields for 5-6 days Then, pedigrees for individual irradiated cells were determined by noting the times of divisions fusions, and cell death. After X-irradiation, the clonogenic survival values for these two cell lines are similar. However, by using computerized video time lapse (CVTL) to follow individual cells we found that the loss of clonogenic survival was due to two different processes, cell death and a senescent-like process. The loss of clonogenic survival of x-irradiated (9.5 and 4 Gy) REC:myc cells was attributed almost entirely to the cells dying by apoptosis (∼99 and 90%). In contrast, approximately 60% of the x-irradiated (9.5 Gy) non-clonogenic REC:ras cells died by apoptosis (with a very small amount of necrosis), and the other 40% underwent a senescent-type process in which some of the cells and their progeny stopped dividing but remained as viable cells throughout 140 hours of observation. Both processes usually occurred after the cells had divided and continued to occur in the cells' progeny for up to five divisions after irradiation. The mode of cell death in the progeny of a non-clonogenic cell can be determined only by using CVTL and can not be determined by conventional clonogenic survival experiments. Also, only by following the individual cells and their progeny can the true amount of apoptosis be determined. The cumulative percentage of apoptosis scored in whole populations

  4. Gingerol sensitizes TRAIL-induced apoptotic cell death of glioblastoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dae-Hee, E-mail: leedneo@gmail.com [Departments of Surgery and Pharmacology and Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA (United States); Kim, Dong-Wook [Department of Microbiology, Immunology, and Cancer Biology, University of VA (United States); Jung, Chang-Hwa [Division of Metabolism and Functionality Research, Korea Food Research Institute (Korea, Republic of); Lee, Yong J. [Departments of Surgery and Pharmacology and Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA (United States); Park, Daeho, E-mail: daehopark@gist.ac.kr [School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of)

    2014-09-15

    Glioblastoma multiforme (GBM) is the most lethal and aggressive astrocytoma of primary brain tumors in adults. Although there are many clinical trials to induce the cell death of glioblastoma cells, most glioblastoma cells have been reported to be resistant to TRAIL-induced apoptosis. Here, we showed that gingerol as a major component of ginger can induce TRAIL-mediated apoptosis of glioblastoma. Gingerol increased death receptor (DR) 5 levels in a p53-dependent manner. Furthermore, gingerol decreased the expression level of anti-apoptotic proteins (survivin, c-FLIP, Bcl-2, and XIAP) and increased pro-apoptotic protein, Bax and truncate Bid, by generating reactive oxygen species (ROS). We also found that the sensitizing effects of gingerol in TRAIL-induced cell death were blocked by scavenging ROS or overexpressing anti-apoptotic protein (Bcl-2). Therefore, we showed the functions of gingerol as a sensitizing agent to induce cell death of TRAIL-resistant glioblastoma cells. This study gives rise to the possibility of applying gingerol as an anti-tumor agent that can be used for the purpose of combination treatment with TRAIL in TRAIL-resistant glioblastoma tumor therapy. - Highlights: • Most GBM cells have been reported to be resistant to TRAIL-induced apoptosis. • Gingerol enhances the expression level of anti-apoptotic proteins by ROS. • Gingerol enhances TRAIL-induced apoptosis through actions on the ROS–Bcl2 pathway.

  5. Cell death by pyroptosis drives CD4 T-cell depletion in HIV-1 infection

    Science.gov (United States)

    Doitsh, Gilad; Galloway, Nicole L. K.; Geng, Xin; Yang, Zhiyuan; Monroe, Kathryn M.; Zepeda, Orlando; Hunt, Peter W.; Hatano, Hiroyu; Sowinski, Stefanie; Muñoz-Arias, Isa; Greene, Warner C.

    2014-01-01

    The pathway causing CD4 T-cell death in HIV-infected hosts remains poorly understood although apoptosis has been proposed as a key mechanism. We now show that caspase-3-mediated apoptosis accounts for the death of only a small fraction of CD4 T cells corresponding to those that are both activated and productively infected. The remaining over 95% of quiescent lymphoid CD4 T cells die by caspase-1-mediated pyroptosis triggered by abortive viral infection. Pyroptosis corresponds to an intensely inflammatory form of programmed cell death in which cytoplasmic contents and pro-inflammatory cytokines, including IL-1β, are released. This death pathway thus links the two signature events in HIV infection--CD4 T-cell depletion and chronic inflammation--and creates a pathogenic vicious cycle in which dying CD4 T cells release inflammatory signals that attract more cells to die. This cycle can be broken by caspase 1 inhibitors shown to be safe in humans, raising the possibility of a new class of `anti-AIDS' therapeutics targeting the host rather than the virus.

  6. Gingerol sensitizes TRAIL-induced apoptotic cell death of glioblastoma cells

    International Nuclear Information System (INIS)

    Lee, Dae-Hee; Kim, Dong-Wook; Jung, Chang-Hwa; Lee, Yong J.; Park, Daeho

    2014-01-01

    Glioblastoma multiforme (GBM) is the most lethal and aggressive astrocytoma of primary brain tumors in adults. Although there are many clinical trials to induce the cell death of glioblastoma cells, most glioblastoma cells have been reported to be resistant to TRAIL-induced apoptosis. Here, we showed that gingerol as a major component of ginger can induce TRAIL-mediated apoptosis of glioblastoma. Gingerol increased death receptor (DR) 5 levels in a p53-dependent manner. Furthermore, gingerol decreased the expression level of anti-apoptotic proteins (survivin, c-FLIP, Bcl-2, and XIAP) and increased pro-apoptotic protein, Bax and truncate Bid, by generating reactive oxygen species (ROS). We also found that the sensitizing effects of gingerol in TRAIL-induced cell death were blocked by scavenging ROS or overexpressing anti-apoptotic protein (Bcl-2). Therefore, we showed the functions of gingerol as a sensitizing agent to induce cell death of TRAIL-resistant glioblastoma cells. This study gives rise to the possibility of applying gingerol as an anti-tumor agent that can be used for the purpose of combination treatment with TRAIL in TRAIL-resistant glioblastoma tumor therapy. - Highlights: • Most GBM cells have been reported to be resistant to TRAIL-induced apoptosis. • Gingerol enhances the expression level of anti-apoptotic proteins by ROS. • Gingerol enhances TRAIL-induced apoptosis through actions on the ROS–Bcl2 pathway

  7. The endoplasmic reticulum in plant immunity and cell death.

    Science.gov (United States)

    Eichmann, Ruth; Schäfer, Patrick

    2012-01-01

    The endoplasmic reticulum (ER) is a highly dynamic organelle in eukaryotic cells and a major production site of proteins destined for vacuoles, the plasma membrane, or apoplast in plants. At the ER, these secreted proteins undergo multiple processing steps, which are supervised and conducted by the ER quality control system. Notably, processing of secreted proteins can considerably elevate under stress conditions and exceed ER folding capacities. The resulting accumulation of unfolded proteins is defined as ER stress. The efficiency of cells to re-establish proper ER function is crucial for stress adaptation. Besides delivering proteins directly antagonizing and resolving stress conditions, the ER monitors synthesis of immune receptors. This indicates the significance of the ER for the establishment and function of the plant immune system. Recent studies point out the fragility of the entire system and highlight the ER as initiator of programed cell death (PCD) in plants as was reported for vertebrates. This review summarizes current knowledge on the impact of the ER on immune and PCD signaling. Understanding the integration of stress signals by the ER bears a considerable potential to optimize development and to enhance stress resistance of plants.

  8. The endoplasmic reticulum in plant immunity and cell death

    Directory of Open Access Journals (Sweden)

    Patrick eSchäfer

    2012-08-01

    Full Text Available The endoplasmic reticulum (ER is a highly dynamic organelle in eukaryotic cells and a major production site of proteins destined for vacuoles, the plasma membrane or apoplast in plants. At the ER, these secreted proteins undergo multiple processing steps, which are supervised and conducted by the ER quality control system. Notably, processing of secreted proteins can considerably elevate under stress conditions and exceed ER folding capacities. The resulting accumulation of unfolded proteins is defined as ER stress. The efficiency of cells to re-establish proper ER function is crucial for stress adaptation. Besides delivering proteins directly antagonizing and resolving stress conditions, the ER monitors synthesis of immune receptors. This indicates the significance of the ER for the establishment and function of the plant immune system. Recent studies point out the fragility of the entire system and highlight the ER as initiator of programmed cell death (PCD in plants as was reported for vertebrates. This review summarizes current knowledge on the impact of the ER on immune and PCD signalling. Understanding the integration of stress signals by the ER bears a considerable potential to optimize development and to enhance stress resistance of plants.

  9. Cell death triggered by alpha-emitting 213Bi-immunoconjugates in HSC45-M2 gastric cancer cells is different from apoptotic cell death

    International Nuclear Information System (INIS)

    Seidl, Christof; Schroeck, Hedwig; Seidenschwang, Sabine; Beck, Roswitha; Schwaiger, Markus; Senekowitsch-Schmidtke, Reingard; Schmid, Ernst; Abend, Michael; Becker, Karl-Friedrich; Apostolidis, Christos; Nikula, Tuomo K.; Kremmer, Elisabeth

    2005-01-01

    Radioimmunotherapy with α-particle-emitting nuclides, such as 213 Bi, is a promising concept for the elimination of small tumour nodules or single disseminated tumour cells. The aim of this study was to investigate cellular damage and the mode of cell death triggered by 213 Bi-immunoconjugates. Human gastric cancer cells (HSC45-M2) expressing d9-E-cadherin were incubated with different levels of activity of 213 Bi-d9MAb targeting d9-E-cadherin and 213 Bi-d8MAb, which does not bind to d9-E-cadherin. Micronucleated (M) cells, abnormal (A) cells and apoptotic (A) [(MAA)] cells were scored microscopically in the MAA assay following fluorescent staining of nuclei and cytoplasm. Chromosomal aberrations were analysed microscopically following Giemsa staining. The effect of z-VAD-fmk, known to inhibit apoptosis, on the prevention of cell death was investigated following treatment of HSC45-M2 cells with sorbitol as well as 213 Bi-d9MAb. Activation of caspase 3 after incubation of HSC45-M2 cells with both sorbitol and 213 Bi-d9MAb was analysed via Western blotting. Following incubation of HSC45-M2 human gastric cancer cells expressing d9-E-cadherin with 213 Bi-d9MAb the number of cells killed increased proportional to the applied activity concentration. Microscopically visible effects of α-irradiation of HSC45-M2 cells were formation of micronuclei and severe chromosomal aberrations. Preferential induction of these lesions with specific 213 Bi-d9MAb compared with unspecific 213 Bi-d8MAb (not targeting d9-E-cadherin) was not observed if the number of floating, i.e. unbound 213 Bi-immunoconjugates per cell exceeded 2 x 10 4 , most likely due to intense crossfire. In contrast to sorbitol-induced cell death, cell death triggered by 213 Bi-immunoconjugates was independent of caspase 3 activation and could not be inhibited by z-VAD-fmk, known to suppress the apoptotic pathway. 213 Bi-immunoconjugates seem to induce a mode of cell death different from apoptosis in HSC45-M2 cells

  10. Cell death triggered by alpha-emitting {sup 213}Bi-immunoconjugates in HSC45-M2 gastric cancer cells is different from apoptotic cell death

    Energy Technology Data Exchange (ETDEWEB)

    Seidl, Christof; Schroeck, Hedwig; Seidenschwang, Sabine; Beck, Roswitha; Schwaiger, Markus; Senekowitsch-Schmidtke, Reingard [Technische Universitaet Muenchen, Department of Nuclear Medicine, Munich (Germany); Schmid, Ernst [National Research Center for Environment and Health, Institute of Radiation Biology, GSF, Neuherberg (Germany); Abend, Michael [German Armed Forces, Institute of Radiobiology, Munich (Germany); Becker, Karl-Friedrich [Technische Universitaet Muenchen, Institute of Pathology, Munich (Germany); National Research Center for Environment and Health, Institute of Pathology, GSF, Neuherberg (Germany); National Research Center for Environment and Health, Institute of Molecular Immunology, GSF, Munich (Germany); Apostolidis, Christos; Nikula, Tuomo K. [European Commission, Institute for Transuranium Elements, Karlsruhe (Germany); Kremmer, Elisabeth [National Research Center for Environment and Health, Institute of Molecular Immunology, GSF, Munich (Germany)

    2005-03-01

    Radioimmunotherapy with {alpha}-particle-emitting nuclides, such as{sup 213}Bi, is a promising concept for the elimination of small tumour nodules or single disseminated tumour cells. The aim of this study was to investigate cellular damage and the mode of cell death triggered by {sup 213}Bi-immunoconjugates. Human gastric cancer cells (HSC45-M2) expressing d9-E-cadherin were incubated with different levels of activity of {sup 213}Bi-d9MAb targeting d9-E-cadherin and {sup 213}Bi-d8MAb, which does not bind to d9-E-cadherin. Micronucleated (M) cells, abnormal (A) cells and apoptotic (A) [(MAA)] cells were scored microscopically in the MAA assay following fluorescent staining of nuclei and cytoplasm. Chromosomal aberrations were analysed microscopically following Giemsa staining. The effect of z-VAD-fmk, known to inhibit apoptosis, on the prevention of cell death was investigated following treatment of HSC45-M2 cells with sorbitol as well as {sup 213}Bi-d9MAb. Activation of caspase 3 after incubation of HSC45-M2 cells with both sorbitol and {sup 213}Bi-d9MAb was analysed via Western blotting. Following incubation of HSC45-M2 human gastric cancer cells expressing d9-E-cadherin with {sup 213}Bi-d9MAb the number of cells killed increased proportional to the applied activity concentration. Microscopically visible effects of {alpha}-irradiation of HSC45-M2 cells were formation of micronuclei and severe chromosomal aberrations. Preferential induction of these lesions with specific {sup 213}Bi-d9MAb compared with unspecific {sup 213}Bi-d8MAb (not targeting d9-E-cadherin) was not observed if the number of floating, i.e. unbound {sup 213}Bi-immunoconjugates per cell exceeded 2 x 10{sup 4}, most likely due to intense crossfire. In contrast to sorbitol-induced cell death, cell death triggered by {sup 213}Bi-immunoconjugates was independent of caspase 3 activation and could not be inhibited by z-VAD-fmk, known to suppress the apoptotic pathway. {sup 213}Bi-immunoconjugates seem

  11. Quantification of cell death in developing cerebellum by a 14C tracer method

    International Nuclear Information System (INIS)

    Griffin, W.S.; Woodward, D.J.; Chanda, R.

    1978-01-01

    To study the question of whether or not cell death contributes significantly to normal or stressed postnatal brain development in a way which is biochemically quantifiable, we carried out an experiment to assess the amount of cell death in developing cerebellum. By measuring the loss of DNA content and the loss of 14 C from labelled thymidine previously incorporated into the DNA fraction (DNAF) in X-irradiated neonatal animals, shown by histological methods to have cell death to the degree of degranulating the external granular layer (EGL), we showed that when cells die both label and DNA content are greatly decreased in the cerebellum. Experiments on both normal and malnourished animals showed that cell death does not contribute significantly to cerebellar development in either malnutrition-stressed or normal animals. Here, we present a biochemical tool for assessing cell death and evidence that cell death does not contribute significantly to cerebellar development

  12. Blocking CD147 induces cell death in cancer cells through impairment of glycolytic energy metabolism

    International Nuclear Information System (INIS)

    Baba, Miyako; Inoue, Masahiro; Itoh, Kazuyuki; Nishizawa, Yasuko

    2008-01-01

    CD147 is a multifunctional transmembrane protein and promotes cancer progression. We found that the anti-human CD147 mouse monoclonal antibody MEM-M6/1 strongly induces necrosis-like cell death in LoVo, HT-29, WiDr, and SW620 colon cancer cells and A2058 melanoma cells, but not in WI-38 and TIG-113 normal fibroblasts. Silencing or overexpression of CD147 in LoVo cells enhanced or decreased the MEM-M6/1 induced cell death, respectively. CD147 is known to form complex with proton-linked monocarboxylate transporters (MCTs), which is critical for lactate transport and intracellular pH (pHi) homeostasis. In LoVo cells, CD147 and MCT-1 co-localized on the cell surface, and MEM-M6/1 inhibited the association of these molecules. MEM-M6/1 inhibited lactate uptake, lactate release, and reduced pHi. Further, the induction of acidification was parallel to the decrease of the glycolytic flux and intracellular ATP levels. These effects were not found in the normal fibroblasts. As cancer cells depend on glycolysis for their energy production, CD147 inhibition might induce cell death specific to cancer cells

  13. 8-aminoadenosine enhances radiation-induced cell death in human lung carcinoma A549 cells

    International Nuclear Information System (INIS)

    Meike, Shunsuke; Yamamori, Tohru; Yasui, Hironobu; Eitaki, Masato; Inanami, Osamu; Matsuda, Akira

    2011-01-01

    The combination of a chemotherapeutic agent and radiation is widely applied to enhance cell death in solid tumor cells in cancer treatment. The purine analogue 8-aminoadenosine (8-NH 2 -Ado) is known to be a transcription inhibitor that has proved very effective in multiple myeloma cell lines and primary indolent leukemia cells. In this report, to examine whether 8-NH 2 -Ado had the ability to enhance the radiation-induced cell killing in solid tumor cells, human lung adenocarcinoma A549 cells were irradiated in the presence and absence of 8-NH 2 -Ado. 8-NH 2 -Ado significantly increased reproductive cell death and apoptosis in A549 cells exposed to X-rays. When peptide inhibitors against caspase-3, -8, and -9 were utilized to evaluate the involvement of caspases, all inhibitors suppressed the enhancement of radiation-induced apoptosis, suggesting that not only mitochondria-mediated apoptotic signal transduction pathways but also death receptor-mediated pathways were involved in this enhancement of apoptosis. In addition, in the cells exposed to the treatment combining X-irradiation and 8-NH 2 -Ado, reduction of the intracellular ATP concentration was essential for survival, and down-regulation of the expression of antiapoptotic proteins such as survivin and X-linked inhibitor of apoptosis protein (XIAP) was observed. These results indicate that 8-NH 2 -Ado has potential not only as an anti-tumor drug for leukemia and lymphoma but also as a radiosensitizing agent for solid tumors. (author)

  14. Bioactive compounds from crocodile (Crocodylus siamensis) white blood cells induced apoptotic cell death in hela cells.

    Science.gov (United States)

    Patathananone, Supawadee; Thammasirirak, Sompong; Daduang, Jureerut; Chung, Jing Gung; Temsiripong, Yosapong; Daduang, Sakda

    2016-08-01

    Crocodile (Crocodylus siamensis) white blood cell extracts (WBCex) were examined for anticancer activity in HeLa cell lines using the MTT assay. The percentage viability of HeLa cells significantly deceased after treatment with WBCex in a dose- and time-dependent manner. The IC50 dose was suggested to be approximately 225 μg/mL protein. Apoptotic cell death occurred in a time-dependent manner based on investigation by flow cytometry using annexin V-FITC and PI staining. DAPI nucleic acid staining indicated increased chromatin condensation. Caspase-3, -8 and -9 activities also increased, suggesting the induction of the caspase-dependent apoptotic pathway. Furthermore, the mitochondrial membrane potential (ΔΨm ) of HeLa cells was lost as a result of increasing levels of Bax and reduced levels of Bcl-2, Bcl-XL, Bcl-Xs, and XIAP. The decreased ΔΨm led to the release of cytochrome c and the activation of caspase-9 and -3. Apoptosis-inducing factor translocated into the nuclei, and endonuclease G (Endo G) was released from the mitochondria. These results suggest that anticancer agents in WBCex can induce apoptosis in HeLa cells via both caspase-dependent and -independent pathways. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 986-997, 2016. © 2015 Wiley Periodicals, Inc.

  15. Caspase-independent cell death mediated by apoptosis-inducing factor (AIF) nuclear translocation is involved in ionizing radiation induced HepG2 cell death

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Hengwen [Department of Radiation, Cancer Center of Guangdong General Hospital (Guangdong Academy of Medical Science), Guangzhou, 510080, Guangdong (China); Yang, Shana; Li, Jianhua [Department of Physiology, Guangzhou Medical University, Guangzhou, 510182, Guangdong (China); Zhang, Yajie [Department of Pathology, Guangzhou Medical University, Guangzhou, 510182, Guangdong (China); Gao, Dongsheng [Department of Oncology, Guangdong Medical College Affiliated Pengpai Memorial Hospital, Hai Feng, 516400, Gungdong (China); Zhao, Shenting, E-mail: zhaoshenting@126.com [Department of Physiology, Guangzhou Medical University, Guangzhou, 510182, Guangdong (China)

    2016-03-25

    Hepatocellular carcinoma (HCC) is the fifth most common cancer in the world. The aim of radiotherapy is to eradicate cancer cells with ionizing radiation. Except for the caspase-dependent mechanism, several lines of evidence demonstrated that caspase-independent mechanism is directly involved in the cell death responding to irradiation. For this reason, defining the contribution of caspase-independent molecular mechanisms represents the main goal in radiotherapy. In this study, we focused on the role of apoptosis-inducing factor (AIF), the caspase-independent molecular, in ionizing radiation induced hepatocellular carcinoma cell line (HepG2) cell death. We found that ionizing radiation has no function on AIF expression in HepG2 cells, but could induce AIF release from the mitochondria and translocate into nuclei. Inhibition of AIF could reduce ionizing radiation induced HepG2 cell death. These studies strongly support a direct relationship between AIF nuclear translocation and radiation induced cell death. What's more, AIF nuclear translocation is caspase-independent manner, but not caspase-dependent manner, in this process. These new findings add a further attractive point of investigation to better define the complex interplay between caspase-independent cell death and radiation therapy. - Highlights: • AIF nuclear translocation is involved in ionizing radiation induced hepatocellular carcinoma cell line HepG2 cell death. • AIF mediated cell death induced by ionizing radiation is caspase-independent. • Caspase-independent pathway is involved in ionzing radiation induced HepG2 cell death.

  16. Effects of 3-styrylchromones on metabolic profiles and cell death in oral squamous cell carcinoma cells

    Directory of Open Access Journals (Sweden)

    Hiroshi Sakagami

    2015-01-01

    Full Text Available 4H-1-benzopyran-4-ones (chromones are important naturally-distributing compounds. As compared with flavones, isoflavones and 2-styrylchromones, there are only few papers of 3-styrylchromones that have been published. We have previously reported that among fifteen 3-styrylchromone derivatives, three new synthetic compounds that have OCH3 group at the C-6 position of chromone ring, (E-3-(4-hydroxystyryl-6-methoxy-4H-chromen-4-one (compound 11, (E-6-methoxy-3-(4-methoxystyryl-4H-chromen-4-one (compound 4, (E-6-methoxy-3-(3,4,5-trimethoxystyryl-4H-chromen-4-one (compound 6 showed much higher cytotoxicities against four epithelial human oral squamous cell carcinoma (OSCC lines than human normal oral mesenchymal cells. In order to further confirm the tumor specificities of these compounds, we compared their cytotoxicities against both human epithelial malignant and non-malignant cells, and then investigated their effects on fine cell structures and metabolic profiles and cell death in human OSCC cell line HSC-2. Cytotoxicities of compounds 4, 6, 11 were assayed with MTT method. Fine cell structures were observed under transmission electron microscope. Cellular metabolites were extracted with methanol and subjected to CE-TOFMS analysis. Compounds 4, 6, 11 showed much weaker cytotoxicity against human oral keratinocyte and primary human gingival epithelial cells, as compared with HSC-2, confirming their tumor-specificity, whereas doxorubicin and 5-FU were highly cytotoxic to these normal epithelial cells, giving unexpectedly lower tumor-specificity. The most cytotoxic compound 11, induced the mitochondrial vacuolization, autophagy suppression followed by apoptosis induction, and changes in the metabolites involved in amino acid and glycerophospholipid metabolisms. Chemical modification of lead compound 11 may be a potential choice for designing new type of anticancer drugs.

  17. A High-Throughput Small Molecule Screen for C. elegans Linker Cell Death Inhibitors.

    Directory of Open Access Journals (Sweden)

    Andrew R Schwendeman

    Full Text Available Programmed cell death is a ubiquitous process in metazoan development. Apoptosis, one cell death form, has been studied extensively. However, mutations inactivating key mammalian apoptosis regulators do not block most developmental cell culling, suggesting that other cell death pathways are likely important. Recent work in the nematode Caenorhabditis elegans identified a non-apoptotic cell death form mediating the demise of the male-specific linker cell. This cell death process (LCD, linker cell-type death is morphologically conserved, and its molecular effectors also mediate axon degeneration in mammals and Drosophila. To develop reagents to manipulate LCD, we established a simple high-throughput screening protocol for interrogating the effects of small molecules on C. elegans linker cell death in vivo. From 23,797 compounds assayed, 11 reproducibly block linker cell death onset. Of these, five induce animal lethality, and six promote a reversible developmental delay. These results provide proof-of principle validation of our screening protocol, demonstrate that developmental progression is required for linker cell death, and suggest that larger scale screens may identify LCD-specific small-molecule regulators that target the LCD execution machinery.

  18. Cytoprotective dibenzoylmethane derivatives protect cells from oxidative stress-induced necrotic cell death.

    Science.gov (United States)

    Hegedűs, Csaba; Lakatos, Petra; Kiss-Szikszai, Attila; Patonay, Tamás; Gergely, Szabolcs; Gregus, Andrea; Bai, Péter; Haskó, György; Szabó, Éva; Virág, László

    2013-06-01

    Screening of a small in-house library of 1863 compounds identified 29 compounds that protected Jurkat cells from hydrogen peroxide-induced cytotoxicity. From the cytoprotective compounds eleven proved to possess antioxidant activity (ABTS radical scavenger effect) and two were found to inhibit poly(ADP-ribosyl)ation (PARylation), a cytotoxic pathway operating in severely injured cells. Four cytoprotective dibenzoylmethane (DBM) derivatives were investigated in more detail as they did not scavenge hydrogen peroxide nor did they inhibit PARylation. These compounds protected cells from necrotic cell death while caspase activation, a parameter of apoptotic cell death was not affected. Hydrogen peroxide activated extracellular signal regulated kinase (ERK1/2) and p38 MAP kinases but not c-Jun N-terminal kinase (JNK). The cytoprotective DBMs suppressed the activation of Erk1/2 but not that of p38. Cytoprotection was confirmed in another cell type (A549 lung epithelial cells), indicating that the cytoprotective effect is not cell type specific. In conclusion we identified DBM analogs as a novel class of cytoprotective compounds inhibiting ERK1/2 kinase and protecting from necrotic cell death by a mechanism independent of poly(ADP-ribose) polymerase inhibition. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Cadmium toxicity in cultured tomato cells - Role of ethylene, proteases and oxidative stress in cell death signaling

    NARCIS (Netherlands)

    Iakimova, E.T.; Woltering, E.J.; Kapchina-Toteva, V.M.; Harren, F.J.M.; Cristescu, S.M.

    2008-01-01

    Our aim was to investigate the ability of cadmium to induce programmed cell death in tomato suspension cells and to determine the involvement of proteolysis, oxidative stress and ethylene. Tomato suspension cells were exposed to treatments with CdSO4 and cell death was calculated after fluorescein

  20. Involvement of ethylene and lipid signalling in cadmium-induced programmed cell death in tomato suspension cells

    NARCIS (Netherlands)

    Yakimova, E.T.; Kapchina-Toteva, V.M.; Laarhoven, L.J.J.; Harren, F.J.M.; Woltering, E.J.

    2006-01-01

    Cadmium-induced cell death was studied in suspension-cultured tomato (Lycopersicon esculentum Mill.) cells (line MsK8) treated with CdSO4. Within 24 h, cadmium treatment induced cell death in a concentration-dependent manner. Cell cultures showed recovery after 23 days which indicates the existence

  1. Involvement of ethylene and lipid signalling in cadmium-induced programmed cell death in tomato suspension cells

    NARCIS (Netherlands)

    Iakimova, E.T.; Kapchina-Toteva, V.M.; Laarhoven, L.J.; Harren, F.; Woltering, E.J.

    2006-01-01

    Cadmium-induced cell death was studied in suspension-cultured tomato (Lycopersicon esculentum Mill.) cells (line MsK8) treated with CdSO4. Within 24 h, cadmium treatment induced cell death in a concentration-dependent manner. Cell cultures showed recovery after 2¿3 days which indicates the existence

  2. Thioredoxin reductase deficiency potentiates oxidative stress, mitochondrial dysfunction and cell death in dopaminergic cells.

    Directory of Open Access Journals (Sweden)

    Pamela Lopert

    Full Text Available Mitochondria are considered major generators of cellular reactive oxygen species (ROS which are implicated in the pathogenesis of neurodegenerative diseases such as Parkinson's disease (PD. We have recently shown that isolated mitochondria consume hydrogen peroxide (H₂O₂ in a substrate- and respiration-dependent manner predominantly via the thioredoxin/peroxiredoxin (Trx/Prx system. The goal of this study was to determine the role of Trx/Prx system in dopaminergic cell death. We asked if pharmacological and lentiviral inhibition of the Trx/Prx system sensitized dopaminergic cells to mitochondrial dysfunction, increased steady-state H₂O₂ levels and death in response to toxicants implicated in PD. Incubation of N27 dopaminergic cells or primary rat mesencephalic cultures with the Trx reductase (TrxR inhibitor auranofin in the presence of sub-toxic concentrations of parkinsonian toxicants paraquat; PQ or 6-hydroxydopamine; 6OHDA (for N27 cells resulted in a synergistic increase in H₂O₂ levels and subsequent cell death. shRNA targeting the mitochondrial thioredoxin reductase (TrxR2 in N27 cells confirmed the effects of pharmacological inhibition. A synergistic decrease in maximal and reserve respiratory capacity was observed in auranofin treated cells and TrxR2 deficient cells following incubation with PQ or 6OHDA. Additionally, TrxR2 deficient cells showed decreased basal mitochondrial oxygen consumption rates. These data demonstrate that inhibition of the mitochondrial Trx/Prx system sensitizes dopaminergic cells to mitochondrial dysfunction, increased steady-state H₂O₂, and cell death. Therefore, in addition to their role in the production of cellular H₂O₂ the mitochondrial Trx/Prx system serve as a major sink for cellular H₂O₂ and its disruption may contribute to dopaminergic pathology associated with PD.

  3. An Ursolic Acid Derived Small Molecule Triggers Cancer Cell Death through Hyperstimulation of Macropinocytosis.

    Science.gov (United States)

    Sun, Lin; Li, Bin; Su, Xiaohui; Chen, Ge; Li, Yaqin; Yu, Linqian; Li, Li; Wei, Wanguo

    2017-08-10

    Macropinocytosis is a transient endocytosis that internalizes extracellular fluid and particles into vacuoles. Recent studies suggest that hyperstimulation of macropinocytosis can induce a novel nonapoptotic cell death, methuosis. In this report, we describe the identification of an ursolic acid derived small molecule (compound 17), which induces cancer cell death through hyperstimulation of macropinocytosis. 17 causes the accumulation of vacuoles derived from macropinosomes based on transmission electron microscopy, time-lapse microscopy, and labeling with extracellular fluid phase tracers. The vacuoles induced by 17 separate from other cytoplasmic compartments but acquire some characteristics of late endosomes and lysosomes. Inhibiting hyperstimulation of macropinocytosis with the specific inhibitor amiloride blocks cell death, implicating that 17 leads to cell death via macropinocytosis, which is coincident with methuosis. Our results uncovered a novel cell death pathway involved in the activity of 17, which may provide a basis for further development of natural-product-derived scaffolds for drugs that trigger cancer cell death by methuosis.

  4. Cell Death Conversion under Hypoxic Condition in Tumor Development and Therapy

    Directory of Open Access Journals (Sweden)

    Yu Qiu

    2015-10-01

    Full Text Available Hypoxia, which is common during tumor progression, plays important roles in tumor biology. Failure in cell death in response to hypoxia contributes to progression and metastasis of tumors. On the one hand, the metabolic and oxidative stress following hypoxia could lead to cell death by triggering signal cascades, like LKB1/AMPK, PI3K/AKT/mTOR, and altering the levels of effective components, such as the Bcl-2 family, Atg and p62. On the other hand, hypoxia-induced autophagy can serve as a mechanism to turn over nutrients, so as to mitigate the adverse condition and then avoid cell death potentially. Due to the effective role of hypoxia, this review focuses on the crosstalk in cell death under hypoxia in tumor progression. Additionally, the illumination of cell death in hypoxia could shed light on the clinical applications of cell death targeted therapy.

  5. Pathways to ischemic neuronal cell death: are sex differences relevant?

    Directory of Open Access Journals (Sweden)

    McCullough Louise D

    2008-06-01

    Full Text Available Abstract We have known for some time that the epidemiology of human stroke is sexually dimorphic until late in life, well beyond the years of reproductive senescence and menopause. Now, a new concept is emerging: the mechanisms and outcome of cerebral ischemic injury are influenced strongly by biological sex as well as the availability of sex steroids to the brain. The principal mammalian estrogen (17 β estradiol or E2 is neuroprotective in many types of brain injury and has been the major focus of investigation over the past several decades. However, it is becoming increasingly clear that although hormones are a major contributor to sex-specific outcomes, they do not fully account for sex-specific responses to cerebral ischemia. The purpose of this review is to highlight recent studies in cell culture and animal models that suggest that genetic sex determines experimental stroke outcome and that divergent cell death pathways are activated after an ischemic insult. These sex differences need to be identified if we are to develop efficacious neuroprotective agents for use in stroke patients.

  6. Role of non-canonical Beclin 1-independent autophagy in cell death induced by resveratrol in human breast cancer cells.

    Science.gov (United States)

    Scarlatti, F; Maffei, R; Beau, I; Codogno, P; Ghidoni, R

    2008-08-01

    Resveratrol, a polyphenol found in grapes and other fruit and vegetables, is a powerful chemopreventive and chemotherapeutic molecule potentially of interest for the treatment of breast cancer. The human breast cancer cell line MCF-7, which is devoid of caspase-3 activity, is refractory to apoptotic cell death after incubation with resveratrol. Here we show that resveratrol arrests cell proliferation, triggers death and decreases the number of colonies of cells that are sensitive to caspase-3-dependent apoptosis (MCF-7 casp-3) and also those that are unresponsive to it (MCF-7vc). We demonstrate that resveratrol (i) acts via multiple pathways to trigger cell death, (ii) induces caspase-dependent and caspase-independent cell death in MCF-7 casp-3 cells, (iii) induces only caspase-independent cell death in MCF-7vc cells and (iv) stimulates macroautophagy. Using BECN1 and hVPS34 (human vacuolar protein sorting 34) small interfering RNAs, we demonstrate that resveratrol activates Beclin 1-independent autophagy in both cell lines, whereas cell death via this uncommon form of autophagy occurs only in MCF-7vc cells. We also show that this variant form of autophagic cell death is blocked by the expression of caspase-3, but not by its enzymatic activity. In conclusion, this study reveals that non-canonical autophagy induced by resveratrol can act as a caspase-independent cell death mechanism in breast cancer cells.

  7. OXIDATIVE STRESS-DEPENDENT ALTERED IMMUNE RESPONSES AND CELL DEATH IN SUBSTANTIA NIGRA AFTER OZONE EXPOSURE IN RAT

    Directory of Open Access Journals (Sweden)

    Selva eRivas - Arancibia

    2015-05-01

    Full Text Available Parkinson’s disease has been associated with the selective loss of neurons in the substantia nigra pars compacta. Increasing evidence suggests that oxidative stress plays a major role. The resulting increase in reactive oxygen species triggers a sequence of events that leads to cell damage, activation of microglia cells and neuroinflammatory responses. Our objective was to study whether chronic exposure to low doses of ozone, which produces oxidative stress itself, induces progressive cell death in conjunction with glial alterations in the substantia nigra. Animals were exposed to an ozone-free air stream (control or to low doses of ozone for 7, 15, 30, 60, or 90 days. Each group underwent 1 spectrophotometric analysis for protein oxidation; 2 western blot testing for microglia reactivity and nuclear factor kappa B expression levels; and 3 immunohistochemistry for cytochrome c, GFAP, Iba-1, NFkB and COX-2. Our results indicate that ozone induces an increase in protein oxidation levels, changes in activated astrocytes and microglia, and cell death. NFkB and cytochrome c showed an increase until 30 days of exposure, while cyclooxygenase 2 in the substantia nigra increased from 7 days up to 90 days of repetitive ozone exposure. These results suggest that oxidative stress caused by ozone exposure induces changes in inflammatory responses and progressive cell death in the substantia nigra in rats, which could also be occurring in Parkinson’s disease.

  8. Inhibition of apoptic cell death induced by Pseudomonas syringae pv. Tabaci and mycotoxin fumonisin B1

    NARCIS (Netherlands)

    Iakimova, E.T.; Batchvorova, R.; Kapchina, V.; Popov, T.; Atanassov, A.; Woltering, E.J.

    2004-01-01

    The impact of programmed cell death (PCD) inhibitors on lesion formation and biochemical events in transgenic (ttr line) and non-transgenic (Nevrokop 1164) tobacco infected with Pseudomonas syringae pv. tabaci was tested. Programmed cell death in tomato cell culture was induced by Fumonisin B1 (FUM)

  9. Sulfated lentinan induced mitochondrial dysfunction leads to programmed cell death of tobacco BY-2 cells.

    Science.gov (United States)

    Wang, Jie; Wang, Yaofeng; Shen, Lili; Qian, Yumei; Yang, Jinguang; Wang, Fenglong

    2017-04-01

    Sulphated lentinan (sLTN) is known to act as a resistance inducer by causing programmed cell death (PCD) in tobacco suspension cells. However, the underlying mechanism of this effect is largely unknown. Using tobacco BY-2 cell model, morphological and biochemical studies revealed that mitochondrial reactive oxygen species (ROS) production and mitochondrial dysfunction contribute to sLNT induced PCD. Cell viability, and HO/PI fluorescence imaging and TUNEL assays confirmed a typical cell death process caused by sLNT. Acetylsalicylic acid (an ROS scavenger), diphenylene iodonium (an inhibitor of NADPH oxidases) and protonophore carbonyl cyanide p-trifluoromethoxyphenyl hydrazone (a protonophore and an uncoupler of mitochondrial oxidative phosphorylation) inhibited sLNT-induced H 2 O 2 generation and cell death, suggesting that ROS generation linked, at least partly, to a mitochondrial dysfunction and caspase-like activation. This conclusion was further confirmed by double-stained cells with the mitochondria-specific marker MitoTracker RedCMXRos and the ROS probe H 2 DCFDA. Moreover, the sLNT-induced PCD of BY-2 cells required cellular metabolism as up-regulation of the AOX family gene transcripts and induction of the SA biosynthesis, the TCA cycle, and miETC related genes were observed. It is concluded that mitochondria play an essential role in the signaling pathway of sLNT-induced ROS generation, which possibly provided new insight into the sLNT-mediated antiviral response, including PCD. Copyright © 2016. Published by Elsevier Inc.

  10. Coniferyl aldehyde attenuates radiation enteropathy by inhibiting cell death and promoting endothelial cell function.

    Science.gov (United States)

    Jeong, Ye-Ji; Jung, Myung Gu; Son, Yeonghoon; Jang, Jun-Ho; Lee, Yoon-Jin; Kim, Sung-Ho; Ko, Young-Gyo; Lee, Yun-Sil; Lee, Hae-June

    2015-01-01

    Radiation enteropathy is a common complication in cancer patients. The aim of this study was to investigate whether radiation-induced intestinal injury could be alleviated by coniferyl aldehyde (CA), an HSF1-inducing agent that increases cellular HSP70 expression. We systemically administered CA to mice with radiation enteropathy following abdominal irradiation (IR) to demonstrate the protective effects of CA against radiation-induced gastrointestinal injury. CA clearly alleviated acute radiation-induced intestinal damage, as reflected by the histopathological data and it also attenuated sub-acute enteritis. CA prevented intestinal crypt cell death and protected the microvasculature in the lamina propria during the acute and sub-acute phases of damage. CA induced HSF1 and HSP70 expression in both intestinal epithelial cells and endothelial cells in vitro. Additionally, CA protected against not only the apoptotic cell death of both endothelial and epithelial cells but also the loss of endothelial cell function following IR, indicating that CA has beneficial effects on the intestine. Our results provide novel insight into the effects of CA and suggest its role as a therapeutic candidate for radiation-induced enteropathy due to its ability to promote rapid re-proliferation of the intestinal epithelium by the synergic effects of the inhibition of cell death and the promotion of endothelial cell function.

  11. BAX/BAK–Independent Mitoptosis during Cell Death Induced by Proteasome Inhibition?

    OpenAIRE

    Lomonosova, Elena; Ryerse, Jan; Chinnadurai, G.

    2009-01-01

    Proteasome inhibitors induce rapid death of cancer cells. We show that in epithelial cancer cells, such death is associated with dramatic and simultaneous up-regulation of several BH3-only proteins, including BIK, BIM, MCL-1S, NOXA, and PUMA, as well as p53. Elevated levels of these proteins seem to be the result of direct inhibition of their proteasomal degradation, induction of transcription, and active translation. Subsequent cell death is independent of BAX, and probably BAK, and proceeds...

  12. alpha-Toxin is a mediator of Staphylococcus aureus-induced cell death and activates caspases via the intrinsic death pathway independently of death receptor signaling

    NARCIS (Netherlands)

    Bantel, H; Sinha, B; Domschke, W; Peters, Georg; Schulze-Osthoff, K; Jänicke, R U

    2001-01-01

    Infections with Staphylococcus aureus, a common inducer of septic and toxic shock, often result in tissue damage and death of various cell types. Although S. aureus was suggested to induce apoptosis, the underlying signal transduction pathways remained elusive. We show that caspase activation and

  13. Control of cell proliferation, endoreduplication, cell size, and cell death by the retinoblastoma-related pathway in maize endosperm

    KAUST Repository

    Sabelli, Paolo A.; Liu, Yan; Dante, Ricardo Augusto; Lizarraga, Lucina E.; Nguyen, Hong N.; Brown, Sara W.; Klingler, John; Yu, Jingjuan; LaBrant, Evan; Layton, Tracy M.; Feldman, Max; Larkins, Brian A.

    2013-01-01

    , and programmed cell death. Although manipulation of these processes could maximize grain yield, how they are regulated and integrated is poorly understood. We show that the Retinoblastoma-related (RBR) pathway controls key aspects of endosperm development

  14. Apoptosis (programmed cell death) as an indicator of xenobiotic toxicity

    International Nuclear Information System (INIS)

    Bond, G.P.

    1989-01-01

    Xenobiotics alter the frequency and pattern of apoptosis (programmed cell death). Preliminary studies identified the mouse liver, with normally low levels of apoptosis, as a preferable test system to the chicken embryo limb, with normally high levels of apoptosis. The major purposes of these investigations, using the apoptogen and necrogen 1,1-dichloroethylene (DCE), were to determine if increases in apoptosis, (1) could be quantified as a direct result of treatment, (2) were dose- and time-dependent, (3) were independent of necrosis, (4) were associated with mitosis in the control of cell numbers and (5) were limited to specific areas of the liver. To these ends, food-deprived female, CF-1 mice were administered DCE ip under varying experimental conditions. Increased apoptosis occurred in a dose- and time-dependent manner after treatment with 12.5, 40, and 125 mg/kg for 0.5, 1, 2, 4 and 8 hr. Peak effects were observed at 4 hr. Apoptosis occurred only in the midzonal/pericentral areas of the liver. At 12.5 mg/kg, there were no effects on biochemical (alanine transaminase) and morphological indices of necrosis, establishing apoptosis as a separate phenomenon from necrosis. Increased 3 H-thymidine incorporation (DNA synthesis), mitosis and the percentage of octaploid hepatocytes occurred from 24-48 hr after treatment with the apoptotic but non-necrotic dose of 40 mg/kg. Apoptosis only occurred in the midzonal/pericentral areas of the liver after multiple doses with DCE, indicating the zonal selectivity of the response. In conclusion, apoptosis, a normally occurring homeostatic process associated with mitosis in the control of cell numbers, is affected by selected xenobiotics in a dose-dependent manner. Xenobiotic-induced apoptosis in the liver occurs at low doses of xenobiotics which cause no other effects on tissue structure or function

  15. Activation of Cyclin-Dependent Kinase 5 Is a Consequence of Cell Death

    Directory of Open Access Journals (Sweden)

    Yixia Ye

    2009-01-01

    Full Text Available Cyclin-dependent kinase 5 (Cdk5 is similar to other Cdks but is activated during cell differentiation and cell death rather than cell division. Since activation of Cdk5 has been reported in many situations leading to cell death, we attempted to determine if it was required for any form of cell death. We found that Cdk5 is activated during apoptotic deaths and that the activation can be detected even when the cells continue to secondary necrosis. This activation can occur in the absence of Bim, calpain, or neutral cathepsins. The kinase is typically activated by p25, derived from p35 by calpain-mediated cleavage, but inhibition of calpain does not affect cell death or the activation of Cdk5. Likewise, RNAi-forced suppression of the synthesis of Cdk5 does not affect the incidence or kinetics of cell death. We conclude that Cdk5 is activated as a consequence of metabolic changes that are common to many forms of cell death. Thus its activation suggests processes during cell death that will be interesting or important to understand, but activation of Cdk5 is not necessary for cells to die.

  16. Terminalia Chebula provides protection against dual modes of necroptotic and apoptotic cell death upon death receptor ligation.

    Science.gov (United States)

    Lee, Yoonjung; Byun, Hee Sun; Seok, Jeong Ho; Park, Kyeong Ah; Won, Minho; Seo, Wonhyoung; Lee, So-Ra; Kang, Kidong; Sohn, Kyung-Cheol; Lee, Ill Young; Kim, Hyeong-Geug; Son, Chang Gue; Shen, Han-Ming; Hur, Gang Min

    2016-04-27

    Death receptor (DR) ligation elicits two different modes of cell death (necroptosis and apoptosis) depending on the cellular context. By screening a plant extract library from cells undergoing necroptosis or apoptosis, we identified a water extract of Terminalia chebula (WETC) as a novel and potent dual inhibitor of DR-mediated cell death. Investigation of the underlying mechanisms of its anti-necroptotic and anti-apoptotic action revealed that WETC or its constituents (e.g., gallic acid) protected against tumor necrosis factor-induced necroptosis via the suppression of TNF-induced ROS without affecting the upstream signaling events. Surprisingly, WETC also provided protection against DR-mediated apoptosis by inhibition of the caspase cascade. Furthermore, it activated the autophagy pathway via suppression of mTOR. Of the WETC constituents, punicalagin and geraniin appeared to possess the most potent anti-apoptotic and autophagy activation effect. Importantly, blockage of autophagy with pharmacological inhibitors or genetic silencing of Atg5 selectively abolished the anti-apoptotic function of WETC. These results suggest that WETC protects against dual modes of cell death upon DR ligation. Therefore, WETC might serve as a potential treatment for diseases characterized by aberrantly sensitized apoptotic or non-apoptotic signaling cascades.

  17. Menadione triggers cell death through ROS-dependent mechanisms involving PARP activation without requiring apoptosis.

    Science.gov (United States)

    Loor, Gabriel; Kondapalli, Jyothisri; Schriewer, Jacqueline M; Chandel, Navdeep S; Vanden Hoek, Terry L; Schumacker, Paul T

    2010-12-15

    Low levels of reactive oxygen species (ROS) can function as redox-active signaling messengers, whereas high levels of ROS induce cellular damage. Menadione generates ROS through redox cycling, and high concentrations trigger cell death. Previous work suggests that menadione triggers cytochrome c release from mitochondria, whereas other studies implicate the activation of the mitochondrial permeability transition pore as the mediator of cell death. We investigated menadione-induced cell death in genetically modified cells lacking specific death-associated proteins. In cardiomyocytes, oxidant stress was assessed using the redox sensor RoGFP, expressed in the cytosol or the mitochondrial matrix. Menadione elicited rapid oxidation in both compartments, whereas it decreased mitochondrial potential and triggered cytochrome c redistribution to the cytosol. Cell death was attenuated by N-acetylcysteine and exogenous glutathione or by overexpression of cytosolic or mitochondria-targeted catalase. By contrast, no protection was observed in cells overexpressing Cu,Zn-SOD or Mn-SOD. Overexpression of antiapoptotic Bcl-X(L) protected against staurosporine-induced cell death, but it failed to confer protection against menadione. Genetic deletion of Bax and Bak, cytochrome c, cyclophilin D, or caspase-9 conferred no protection against menadione-induced cell death. However, cells lacking PARP-1 showed a significant decrease in menadione-induced cell death. Thus, menadione induces cell death through the generation of oxidant stress in multiple subcellular compartments, yet cytochrome c, Bax/Bak, caspase-9, and cyclophilin D are dispensable for cell death in this model. These studies suggest that multiple redundant cell death pathways are activated by menadione, but that PARP plays an essential role in mediating each of them. Copyright © 2010 Elsevier Inc. All rights reserved.

  18. Prodigiosin activates endoplasmic reticulum stress cell death pathway in human breast carcinoma cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Mu-Yun [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Shen, Yuh-Chiang [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); National Research Institute of Chinese Medicine, Taipei, Taiwan (China); Lu, Chien-Hsing [Department of Obstetrics and Gynecology, Taichung Veterans General Hospital, Taichung, Taiwan (China); Department of Obstetrics and Gynecology, National Yang-Ming University School of Medicine, Taipei, Taiwan (China); Yang, Shu-Yi [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Ho, Tsing-Fen [Department of Medical Laboratory Science and Biotechnology, Central Taiwan University of Science and Technology, Taichung, Taiwan (China); Peng, Yu-Ta [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Chang, Chia-Che, E-mail: chia_che@dragon.nchu.edu.tw [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Agricultural Biotechnology Center, National Chung Hsing University, Taichung, Taiwan (China); Graduate Institute of Basic Medical Science, China Medical University, Taichung, Taiwan (China)

    2012-12-15

    Prodigiosin is a bacterial tripyrrole pigment with potent cytotoxicity against diverse human cancer cell lines. Endoplasmic reticulum (ER) stress is initiated by accumulation of unfolded or misfolded proteins in the ER lumen and may induce cell death when irremediable. In this study, the role of ER stress in prodigiosin-induced cytotoxicity was elucidated for the first time. Comparable to the ER stress inducer thapsigargin, prodigiosin up-regulated signature ER stress markers GRP78 and CHOP in addition to activating the IRE1, PERK and ATF6 branches of the unfolded protein response (UPR) in multiple human breast carcinoma cell lines, confirming prodigiosin as an ER stress inducer. Prodigiosin transcriptionally up-regulated CHOP, as evidenced by its promoting effect on the CHOP promoter activity. Of note, knockdown of CHOP effectively lowered prodigiosin's capacity to evoke PARP cleavage, reduce cell viability and suppress colony formation, highlighting an essential role of CHOP in prodigiosin-induced cytotoxic ER stress response. In addition, prodigiosin down-regulated BCL2 in a CHOP-dependent manner. Importantly, restoration of BCL2 expression blocked prodigiosin-induced PARP cleavage and greatly enhanced the survival of prodigiosin-treated cells, suggesting that CHOP-dependent BCL2 suppression mediates prodigiosin-elicited cell death. Moreover, pharmacological inhibition of JNK by SP600125 or dominant-negative blockade of PERK-mediated eIF2α phosphorylation impaired prodigiosin-induced CHOP up-regulation and PARP cleavage. Collectively, these results identified ER stress-mediated cell death as a mode-of-action of prodigiosin's tumoricidal effect. Mechanistically, prodigiosin engages the IRE1–JNK and PERK–eIF2α branches of the UPR signaling to up-regulate CHOP, which in turn mediates BCL2 suppression to induce cell death. Highlights: ► Prodigiosin is a bacterial tripyrrole pigment with potent anticancer effect. ► Prodigiosin is herein identified

  19. Prodigiosin activates endoplasmic reticulum stress cell death pathway in human breast carcinoma cell lines

    International Nuclear Information System (INIS)

    Pan, Mu-Yun; Shen, Yuh-Chiang; Lu, Chien-Hsing; Yang, Shu-Yi; Ho, Tsing-Fen; Peng, Yu-Ta; Chang, Chia-Che

    2012-01-01

    Prodigiosin is a bacterial tripyrrole pigment with potent cytotoxicity against diverse human cancer cell lines. Endoplasmic reticulum (ER) stress is initiated by accumulation of unfolded or misfolded proteins in the ER lumen and may induce cell death when irremediable. In this study, the role of ER stress in prodigiosin-induced cytotoxicity was elucidated for the first time. Comparable to the ER stress inducer thapsigargin, prodigiosin up-regulated signature ER stress markers GRP78 and CHOP in addition to activating the IRE1, PERK and ATF6 branches of the unfolded protein response (UPR) in multiple human breast carcinoma cell lines, confirming prodigiosin as an ER stress inducer. Prodigiosin transcriptionally up-regulated CHOP, as evidenced by its promoting effect on the CHOP promoter activity. Of note, knockdown of CHOP effectively lowered prodigiosin's capacity to evoke PARP cleavage, reduce cell viability and suppress colony formation, highlighting an essential role of CHOP in prodigiosin-induced cytotoxic ER stress response. In addition, prodigiosin down-regulated BCL2 in a CHOP-dependent manner. Importantly, restoration of BCL2 expression blocked prodigiosin-induced PARP cleavage and greatly enhanced the survival of prodigiosin-treated cells, suggesting that CHOP-dependent BCL2 suppression mediates prodigiosin-elicited cell death. Moreover, pharmacological inhibition of JNK by SP600125 or dominant-negative blockade of PERK-mediated eIF2α phosphorylation impaired prodigiosin-induced CHOP up-regulation and PARP cleavage. Collectively, these results identified ER stress-mediated cell death as a mode-of-action of prodigiosin's tumoricidal effect. Mechanistically, prodigiosin engages the IRE1–JNK and PERK–eIF2α branches of the UPR signaling to up-regulate CHOP, which in turn mediates BCL2 suppression to induce cell death. Highlights: ► Prodigiosin is a bacterial tripyrrole pigment with potent anticancer effect. ► Prodigiosin is herein identified as an

  20. Radiation induced cell death in cervical squamous cell carcinoma. An immunohistochemical and ultrastructural study

    International Nuclear Information System (INIS)

    Atari, Eio; Toda, Takayoshi; Sadi, A.M.; Egawa, Haruhiko; Moromizato, Hidehiko; Mamadi, T.; Kiyuna, Masaya

    1998-01-01

    To study the process of cell death in cervical squamous cell carcinoma (SCC) after radiation, an ultrastructural and immunohistochemical study was performed. Paraffin-embedded tissue blocks of biopsy samples pre- and post-radiation stage III SCC (n=15) were collected. Irradiation caused varying ultrastructural changes including nuclear and cytoplasmic disorganization suggesting cell necrosis. Immunohistochemically, the pre-radiation specimens showed no positive reaction for tumor necrosis factor-alpha (TNF-α), tumor necrosis factor-receptor (TNF-γ) or Fas. C-fos, p53 and bcl-2 showed positive reactions in only a few non-irradiated specimens. All of the irradiated specimens showed a positive reaction for TNF-α, and variable positive reactions were observed for TNF-γ, Fas, p53, c-fos and bcl-2. These results suggest that TNF-α, TNF-γ, and c-fos are responsible for radiation induced cell death in cervical SCC. (author)

  1. Human colon cancer HT-29 cell death responses to doxorubicin and Morus Alba leaves flavonoid extract.

    Science.gov (United States)

    Fallah, S; Karimi, A; Panahi, G; Gerayesh Nejad, S; Fadaei, R; Seifi, M

    2016-03-31

    The mechanistic basis for the biological properties of Morus alba flavonoid extract (MFE) and chemotherapy drug of doxorubicin on human colon cancer HT-29 cell line death are unknown. The effect of doxorubicin and flavonoid extract on colon cancer HT-29 cell line death and identification of APC gene expression and PARP concentration of HT-29 cell line were investigated. The results showed that flavonoid extract and doxorubicin induce a dose dependent cell death in HT-29 cell line. MFE and doxorubicin exert a cytotoxic effect on human colon cancer HT-29 cell line by probably promoting or induction of apoptosis.

  2. WNT7b mediates macrophage-induced programmed cell death in patterning of the vasculature

    OpenAIRE

    Lobov, Ivan B.; Rao, Sujata; Carroll, Thomas J.; Vallance, Jefferson E.; Ito, Masataka; Ondr, Jennifer K.; Kurup, Savita; Glass, Donald A.; Patel, Millan S.; Shu, Weiguo; Morrisey, Edward E.; McMahon, Andrew P.; Karsenty, Gerard; Lang, Richard A.

    2005-01-01

    Macrophages have a critical role in inflammatory and immune responses through their ability to recognize and engulf apoptotic cells1. Here we show that macrophages initiate a cell-death programme in target cells by activating the canonical WNT pathway. We show in mice that macrophage WNT7b is a short-range paracrine signal required for WNT-pathway responses and programmed cell death in the vascular endothelial cells of the temporary hyaloid vessels of the developing eye. These findings indica...

  3. Triptolide induces lysosomal-mediated programmed cell death in MCF-7 breast cancer cells

    Directory of Open Access Journals (Sweden)

    Owa C

    2013-09-01

    Full Text Available Chie Owa, Michael E Messina Jr, Reginald HalabyDepartment of Biology, Montclair State University, Montclair, NJ, USABackground: Breast cancer is a major cause of death; in fact, it is the most common type, in order of the number of global deaths, of cancer in women worldwide. This research seeks to investigate how triptolide, an extract from the Chinese herb Tripterygium wilfordii Hook F, induces apoptosis in MCF-7 human breast cancer cells. Accumulating evidence suggests a role for lysosomal proteases in the activation of apoptosis. However, there is also some controversy regarding the direct participation of lysosomal proteases in activation of key apoptosis-related caspases and release of mitochondrial cytochrome c. In the present study, we demonstrate that triptolide induces an atypical, lysosomal-mediated apoptotic cell death in MCF-7 cells because they lack caspase-3.Methods: MCF-7 cell death was characterized via cellular morphology, chromatin condensation, 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide colorimetric cell growth inhibition assay and the expression levels of proapoptotic proteins. Acridine orange and LysoTracker® staining were performed to visualize lysosomes. Lysosomal enzymatic activity was monitored using an acid phosphatase assay and western blotting of cathepsin B protein levels in the cytosolic fraction, which showed increased enzymatic activity in drug-treated cells.Results: These experiments suggest that triptolide-treated MCF-7 cells undergo atypical apoptosis and that, during the early stages, lysosomal enzymes leak into the cytosol, indicating lysosomal membrane permeability.Conclusion: Our results suggest that further studies are warranted to investigate triptolide's potential as an anticancer therapeutic agent.Keywords: triptolide, MCF-7 breast cancer cells, apoptosis, lysosomes, lysosomal membrane permeabilization (LMP

  4. Crotamine and crotoxin interact with tumor cells and trigger cell death

    International Nuclear Information System (INIS)

    Soares, Marcella Araugio; Pujatti, Priscilla Brunelli; Santos, Raquel Gouvea dos; Dias, Consuelo Latorre Fortes; Chavez Olortegui, Carlos Delfin; Santos, Wagner Gouvea dos

    2007-01-01

    Crotoxin (Crtx) and Crotamine (Crota) are polypeptides isolated from Crotalus durissus terrificus snake venom (CV). Previous reports have been shown therapeutic effects of Crotalus durissus terrificus venom and Crtx on skin, breast and lung tumours, although, the mechanisms of this antitumoral effect are still unknown. The aim of this work was to investigate the antitumoral effect of Crtx and Crota on brain tumours cells (GH3 and RT2) in vitro and their capacity of interaction with these tumour cells membranes. Cell survival after Crtx and Crota treatment was evaluated by MTT assay in different times post-treatment and apoptosis was evaluated by DAPI staining. In order to evaluate the specific interaction of Crtx and Crota, these polypeptides were radiolabelled, using 125 I as radiotracer and binding assays were performed. The results were compared with the binding in nontumoral brain tissue. Crtx and Crota induced apoptosis on both tumour cells lineages but, Crota was more powerful than Crtx 90% and 20% cell death for RT2 cells; 80% and 20% cell death for GH3 cells, respectively). Both 125 I-Crtx and 125 I-Crota bound specifically in glioblastoma membranes. Nonetheless, CV polypeptides recognised glioblastoma cells with higher specificity than normal brain tissue. These results suggest that the Crtx and Crota interactions with the plasmatic membrane of tumour cells may be the first step of the cascade of signalling that trigger their antitumoral effect. (author)

  5. Dying cells protect survivors from radiation-induced cell death in Drosophila.

    Directory of Open Access Journals (Sweden)

    Amber Bilak

    2014-03-01

    Full Text Available We report a phenomenon wherein induction of cell death by a variety of means in wing imaginal discs of Drosophila larvae resulted in the activation of an anti-apoptotic microRNA, bantam. Cells in the vicinity of dying cells also become harder to kill by ionizing radiation (IR-induced apoptosis. Both ban activation and increased protection from IR required receptor tyrosine kinase Tie, which we identified in a genetic screen for modifiers of ban. tie mutants were hypersensitive to radiation, and radiation sensitivity of tie mutants was rescued by increased ban gene dosage. We propose that dying cells activate ban in surviving cells through Tie to make the latter cells harder to kill, thereby preserving tissues and ensuring organism survival. The protective effect we report differs from classical radiation bystander effect in which neighbors of irradiated cells become more prone to death. The protective effect also differs from the previously described effect of dying cells that results in proliferation of nearby cells in Drosophila larval discs. If conserved in mammals, a phenomenon in which dying cells make the rest harder to kill by IR could have implications for treatments that involve the sequential use of cytotoxic agents and radiation therapy.

  6. Activation-induced cell death of dendritic cells is dependent on sphingosine kinase 1

    Directory of Open Access Journals (Sweden)

    Anja eSchwiebs

    2016-04-01

    Full Text Available Sphingosine 1-phosphate (S1P is an immune modulatory lipid mediator and has been implicated in numerous pathophysiological processes. S1P is produced by sphingosine kinase 1 (Sphk1 and Sphk2. Dendritic cells (DCs are central for the direction of immune responses and crucially involved in autoimmunity and cancerogenesis. In this study we examined the function and survival of bone marrow-derived DCs under long-term inflammatory stimulation. We observed that differentiated cells undergo activation-induced cell death upon LPS stimulation with an increased metabolic activity shortly after stimulation, followed by a rapid activation of caspase 3 and subsequent augmented apoptosis. Importantly, we highlight a profound role of Sphk1 in secretion of inflammatory cytokines and survival of dendritic cells that might be mediated by a change in sphingolipid levels as well as by a change in STAT3 expression. Cell growth during differentiation of Sphk1-deficient cells treated with the functional S1P receptor antagonist FTYP was reduced. Importantly, in dendritic cells we did not observe a compensatory regulation of Sphk2 mRNA in Sphk1-deficient cells. Instead, we discovered a massive increase in Sphk1 mRNA concentration upon long-term stimulation with LPS in wild type cells that might function as an attempt to rescue from inflammation-caused cell death. Taken together, in this investigation we describe details of a crucial involvement of sphingolipids and Sphk1 in activation-induced cell death during long-term immunogenic activity of DCs that might play an important role in autoimmunity and might explain the differences in immune response observed in in vivo studies of Sphk1 modulation.

  7. Nanotoxicity: An Interplay of Oxidative Stress, Inflammation and Cell Death

    Directory of Open Access Journals (Sweden)

    Puja Khanna

    2015-06-01

    Full Text Available Nanoparticles are emerging as a useful tool for a wide variety of biomedical, consumer and instrumental applications that include drug delivery systems, biosensors and environmental sensors. In particular, nanoparticles have been shown to offer greater specificity with enhanced bioavailability and less detrimental side effects as compared to the existing conventional therapies in nanomedicine. Hence, bionanotechnology has been receiving immense attention in recent years. However, despite the extensive use of nanoparticles today, there is still a limited understanding of nanoparticle-mediated toxicity. Both in vivo and in vitro studies have shown that nanoparticles are closely associated with toxicity by increasing intracellular reactive oxygen species (ROS levels and/or the levels of pro-inflammatory mediators. The homeostatic redox state of the host becomes disrupted upon ROS induction by nanoparticles. Nanoparticles are also known to up-regulate the transcription of various pro-inflammatory genes, including tumor necrosis factor-α and IL (interleukins-1, IL-6 and IL-8, by activating nuclear factor-kappa B (NF-κB signaling. These sequential molecular and cellular events are known to cause oxidative stress, followed by severe cellular genotoxicity and then programmed cell death. However, the exact molecular mechanisms underlying nanotoxicity are not fully understood. This lack of knowledge is a significant impediment in the use of nanoparticles in vivo. In this review, we will provide an assessment of signaling pathways that are involved in the nanoparticle- induced oxidative stress and propose possible strategies to circumvent nanotoxicity.

  8. Nanotoxicity: An Interplay of Oxidative Stress, Inflammation and Cell Death.

    Science.gov (United States)

    Khanna, Puja; Ong, Cynthia; Bay, Boon Huat; Baeg, Gyeong Hun

    2015-06-30

    Nanoparticles are emerging as a useful tool for a wide variety of biomedical, consumer and instrumental applications that include drug delivery systems, biosensors and environmental sensors. In particular, nanoparticles have been shown to offer greater specificity with enhanced bioavailability and less detrimental side effects as compared to the existing conventional therapies in nanomedicine. Hence, bionanotechnology has been receiving immense attention in recent years. However, despite the extensive use of nanoparticles today, there is still a limited understanding of nanoparticle-mediated toxicity. Both in vivo and in vitro studies have shown that nanoparticles are closely associated with toxicity by increasing intracellular reactive oxygen species (ROS) levels and/or the levels of pro-inflammatory mediators. The homeostatic redox state of the host becomes disrupted upon ROS induction by nanoparticles. Nanoparticles are also known to up-regulate the transcription of various pro-inflammatory genes, including tumor necrosis factor-α and IL (interleukins)-1, IL-6 and IL-8, by activating nuclear factor-kappa B (NF-κB) signaling. These sequential molecular and cellular events are known to cause oxidative stress, followed by severe cellular genotoxicity and then programmed cell death. However, the exact molecular mechanisms underlying nanotoxicity are not fully understood. This lack of knowledge is a significant impediment in the use of nanoparticles in vivo . In this review, we will provide an assessment of signaling pathways that are involved in the nanoparticle- induced oxidative stress and propose possible strategies to circumvent nanotoxicity.

  9. Cell Death Pathways in Photodynamic Therapy of Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Mroz, Pawel, E-mail: pmroz@partners.org [Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA 02114 (United States); Department of Dermatology, Harvard Medical School, Boston, MA 02114 (United States); Yaroslavsky, Anastasia [Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA 02114 (United States); Boston University College of Engineering, Boston, MA 02114 (United States); Kharkwal, Gitika B [Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA 02114 (United States); Department of Dermatology, Harvard Medical School, Boston, MA 02114 (United States); Hamblin, Michael R. [Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA 02114 (United States); Department of Dermatology, Harvard Medical School, Boston, MA 02114 (United States); Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA 02139 (United States)

    2011-06-03

    Photodynamic therapy (PDT) is an emerging cancer therapy that uses the combination of non-toxic dyes or photosensitizers (PS) and harmless visible light to produce reactive oxygen species and destroy tumors. The PS can be localized in various organelles such as mitochondria, lysosomes, endoplasmic reticulum, Golgi apparatus and plasma membranes and this sub-cellular location governs much of the signaling that occurs after PDT. There is an acute stress response that leads to changes in calcium and lipid metabolism and causes the production of cytokines and stress response mediators. Enzymes (particularly protein kinases) are activated and transcription factors are expressed. Many of the cellular responses center on mitochondria and frequently lead to induction of apoptosis by the mitochondrial pathway involving caspase activation and release of cytochrome c. Certain specific proteins (such as Bcl-2) are damaged by PDT-induced oxidation thereby increasing apoptosis, and a build-up of oxidized proteins leads to an ER-stress response that may be increased by proteasome inhibition. Autophagy plays a role in either inhibiting or enhancing cell death after PDT.

  10. Cell Death Pathways in Photodynamic Therapy of Cancer

    International Nuclear Information System (INIS)

    Mroz, Pawel; Yaroslavsky, Anastasia; Kharkwal, Gitika B; Hamblin, Michael R.

    2011-01-01

    Photodynamic therapy (PDT) is an emerging cancer therapy that uses the combination of non-toxic dyes or photosensitizers (PS) and harmless visible light to produce reactive oxygen species and destroy tumors. The PS can be localized in various organelles such as mitochondria, lysosomes, endoplasmic reticulum, Golgi apparatus and plasma membranes and this sub-cellular location governs much of the signaling that occurs after PDT. There is an acute stress response that leads to changes in calcium and lipid metabolism and causes the production of cytokines and stress response mediators. Enzymes (particularly protein kinases) are activated and transcription factors are expressed. Many of the cellular responses center on mitochondria and frequently lead to induction of apoptosis by the mitochondrial pathway involving caspase activation and release of cytochrome c. Certain specific proteins (such as Bcl-2) are damaged by PDT-induced oxidation thereby increasing apoptosis, and a build-up of oxidized proteins leads to an ER-stress response that may be increased by proteasome inhibition. Autophagy plays a role in either inhibiting or enhancing cell death after PDT

  11. Calcium regulates cell death in cancer: Roles of the mitochondria and mitochondria-associated membranes (MAMs).

    Science.gov (United States)

    Danese, Alberto; Patergnani, Simone; Bonora, Massimo; Wieckowski, Mariusz R; Previati, Maurizio; Giorgi, Carlotta; Pinton, Paolo

    2017-08-01

    Until 1972, the term 'apoptosis' was used to differentiate the programmed cell death that naturally occurs in organismal development from the acute tissue death referred to as necrosis. Many studies on cell death and programmed cell death have been published and most are, at least to some degree, related to cancer. Some key proteins and molecular pathways implicated in cell death have been analyzed, whereas others are still being actively researched; therefore, an increasing number of cellular compartments and organelles are being implicated in cell death and cancer. Here, we discuss the mitochondria and subdomains of the endoplasmic reticulum (ER) that interact with mitochondria, the mitochondria-associated membranes (MAMs), which have been identified as critical hubs in the regulation of cell death and tumor growth. MAMs-dependent calcium (Ca 2+ ) release from the ER allows selective Ca 2+ uptake by the mitochondria. The perturbation of Ca 2+ homeostasis in cancer cells is correlated with sustained cell proliferation and the inhibition of cell death through the modulation of Ca 2+ signaling. This article is part of a Special Issue entitled Mitochondria in Cancer, edited by Giuseppe Gasparre, Rodrigue Rossignol and Pierre Sonveaux. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Effects of two doses of anti-T lymphocyte globulin-Fresenius given after full-match sibling stem cell transplantation in acute myeloblastic leukemia patients who underwent myeloablative fludarabine/busulfan conditioning.

    Science.gov (United States)

    Boga, Can; Yeral, Mahmut; Gereklioglu, Ciğdem; Asma, Suheyl; Maytalman, Erkan; Aytan, Pelin; Kozanoglu, Ilknur; Sariturk, Cagla; Ozdogu, Hakan

    2018-02-20

    Anti-T lymphocyte globulin Fresenius (rATG-F; ATG-Fresenius) and antithymocyte globulin (thymoglobulin), which are included in transplant protocols, are used to reduce the risk of chronic graft-versus-host disease (cGVHD) or suppress allograft rejection. Available clinical studies have been conducted in heterogenous patient populations and with different administration protocols including stem cell sources. Additionally, the pharmacokinetics of ATG is variable, and the clinically effective dose of rATG-F, in particular, is not exactly known. The aim of the study was to investigate the clinical outcomes of acute myeloid leukemia (AML) patients who underwent hemopoietic peripheral stem cell transplantation from full-matched sibling donors and given two different doses of r-ATG-F. This was a single-center, retrospective chart review conducted between July 2005 and July 2016. Sixty-nine consecutive AML patients who underwent transplant with fludarabine- and busulfan-based conditioning were included in the study. Patients in Group 1 received 15 mg/kg body weight rATG-F to 2013 (n = 46), and Group 2 received 30 mg/kg of rATG-F dose begining in 2013 to reduce to cGVHD (n = 23). Cyclosporine and methotrexate were used to treat acute GVHD (aGVHD) prophylaxis. Outcome parameters were compared between the groups. Although the recommended dose r-ATG-F had led to a decrease in the cumulative incidence of cGVHD (27 [58.7%] vs. 8 [34.8%]; p = .03), it also increased the infection rate at 1 year (3 [6.5%] vs. 4 [17.4%]; p = .02). The two groups were similar in terms of engraftment time, aGVHD, relapse, nonrelapse mortality, and rATG-F-related toxicity. A Cox regression model revealed that aGVHD III-IV was associated with increased nonrelapse mortality at 1 year (hazard ratio = 18.2; 95% confidence interval, 1.667-199.255; p = <.02). No patients developed rATG-F-related severe adverse events (Common Terminology Criteria grade 4 or 5). Dose difference of

  13. The Prognostic Significance of Elevated Serum Ferritin Levels Prior to Transplantation in Patients With Lymphoma Who Underwent Autologous Hematopoietic Stem Cell Transplantation (autoHSCT): Role of Iron Overload.

    Science.gov (United States)

    Sivgin, Serdar; Karamustafaoglu, Mehmet Fatih; Yildizhan, Esra; Zararsiz, Gokmen; Kaynar, Leylagul; Eser, Bulent; Cetin, Mustafa; Unal, Ali

    2016-08-01

    Hematopoietic stem cell transplantation is a common and preferred treatment of lymphomas in many centers. Our goal was to determine the association between pretransplant iron overload and survival in patients who underwent autologous hematopoietic stem cell transplantation (autoHSCT). A total of 165 patients with lymphoma, who underwent autoHSCT between the years of 2007 and 2014, were included in this study. Ferritin levels were used to determine iron status; the cut-off value was 500 ng/mL. The relationship between iron overload and survival was assessed by statistical analysis. The median ferritin level in the normal ferritin (ferritin < 500) group was 118 ng/mL (range, 9-494 ng/mL) and in the high-ferritin group (ferritin ≥ 500), it was 908 ng/mL (range, 503-4549 ng/mL). A total of 64 (38.8%) patients died during follow-up. Of these patients that died, 52 (81.25%) were in the high-ferritin group, and 12 (18.75%) were in the normal ferritin group (P ≤ .001). Twelve (14.1%) of 85 patients died in the normal ferritin group, and 52 (65.0%) of 80 patients died in the high-ferritin group. The overall mortality was significantly higher in the high-ferritin group (P < .001). The median overall survival was 42 months (range, 25-56 months) in the normal-ferritin group and20 months (range, 5-46) in the high-ferritin group. The difference between the groups was statistically significant (P < .001). The median disease-free survival was 39 months (range, 16-56) in the normal ferritin group and 10 months (range, 3-29) in the high-ferritin group. The difference between the groups was statistically significant (P < .001). Elevated serum ferritin levels might predict poorer survival in autoHSCT recipients. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Role of cell death in the propagation of PrP(Sc) in immune cells.

    Science.gov (United States)

    Takahashi, Kenichi; Inoshima, Yasuo; Ishiguro, Naotaka

    2015-03-01

    A number of studies have suggested that macrophages, dendritic cells, and follicular dendritic cells play an important role in the propagation of PrP(Sc). Both accumulation and proteolysis of PrP(Sc) have been demonstrated in peripheral macrophages. Macrophages may act as reservoirs for PrP(Sc) particles if the cells die during transient PrP(Sc) propagation. However, whether cell death plays a role in PrP(Sc) propagation in macrophages remains unclear. In this study, we investigated the possibility of propagation and transmission of PrP(Sc) between dead immune cells and living neural cells. We found that under specific conditions, transient PrP(Sc) propagation occurs in dead cells, indicating that interaction between PrP(C) and PrP(Sc) on plasma membrane lipid rafts might be important for PrP(Sc) propagation. Co-culturing of killed donor PrP(Sc)-infected macrophages with recipient N2a-3 neuroblastoma cells accelerated PrP(Sc) transmission. Our results suggest that cell death may play an important role in PrP(Sc) propagation, whereas transient PrP(Sc) propagation in macrophages has little effect on PrP(Sc) transmission.

  15. RBE of neutrons for induction of cell reproductive death and chromosome aberrations in three cell lines

    International Nuclear Information System (INIS)

    Zoetelief, J.; Kuijpers, W.C.; Baten-Wittwer, A.; Barendsen, G.W.

    1983-01-01

    The authors have compared the RBE values for induction of dicentrics and centric rings with those for cell inactivation and with the mean or effective quality factors (Q) recommended for radiation protection. The induction of cell reproductive death and chromosome aberrations has been investigated in plateau phase cultures of established lines of a rat rhabdomyosarcoma, a rat ureter carcinoma and Chinese hamster cells for single doses of 300 kV X-rays and 0.5, 4.2 and 15 MeV neutrons. The different cell lines show considerable variations in sensitivity and the RBE values obtained are presented in tabular form. The mean RBE values for the rat rhabdomyosarcoma cells are lower than those for the other two relatively resistant cell lines. Those for the Chinese hamster cells extrapolated to levels according to low doses of X-rays are in good agreement with the quoted Q values. (Auth./C.F.)

  16. Streptococcus sanguinis induces neutrophil cell death by production of hydrogen peroxide.

    Science.gov (United States)

    Sumioka, Ryuichi; Nakata, Masanobu; Okahashi, Nobuo; Li, Yixuan; Wada, Satoshi; Yamaguchi, Masaya; Sumitomo, Tomoko; Hayashi, Mikako; Kawabata, Shigetada

    2017-01-01

    Streptococcus is the dominant bacterial genus in the human oral cavity and a leading cause of infective endocarditis. Streptococcus sanguinis belongs to the mitis group of streptococci and produces hydrogen peroxide (H2O2) by the action of SpxB, a pyruvate oxidase. In this study, we investigated the involvement of SpxB in survival of S. sanguinis in human blood and whether bacterial H2O2 exhibits cytotoxicity against human neutrophils. Results of a bactericidal test with human whole blood revealed that the spxB mutation in S. sanguinis is detrimental to its survival in blood. When S. sanguinis strains were exposed to isolated neutrophils, the bacterial survival rate was significantly decreased by spxB deletion. Furthermore, human neutrophils exposed to the S. sanguinis wild-type strain, in contrast to those exposed to an spxB mutant strain, underwent cell death with chromatin de-condensation and release of web-like extracellular DNA, reflecting induction of neutrophil extracellular traps (NETs). Since reactive oxygen species-mediated NET induction requires citrullination of arginine residues in histone proteins and subsequent chromatin de-condensation, we examined citrullination levels of histone in infected neutrophils. It is important to note that the citrullinated histone H3 was readily detected in neutrophils infected with the wild-type strain, as compared to infection with the spxB mutant strain. Moreover, decomposition of streptococcal H2O2 with catalase reduced NET induction. These results suggest that H2O2 produced by S. sanguinis provokes cell death of neutrophils and NET formation, thus potentially affecting bacterial survival in the bloodstream.

  17. Streptococcus sanguinis induces neutrophil cell death by production of hydrogen peroxide.

    Directory of Open Access Journals (Sweden)

    Ryuichi Sumioka

    Full Text Available Streptococcus is the dominant bacterial genus in the human oral cavity and a leading cause of infective endocarditis. Streptococcus sanguinis belongs to the mitis group of streptococci and produces hydrogen peroxide (H2O2 by the action of SpxB, a pyruvate oxidase. In this study, we investigated the involvement of SpxB in survival of S. sanguinis in human blood and whether bacterial H2O2 exhibits cytotoxicity against human neutrophils. Results of a bactericidal test with human whole blood revealed that the spxB mutation in S. sanguinis is detrimental to its survival in blood. When S. sanguinis strains were exposed to isolated neutrophils, the bacterial survival rate was significantly decreased by spxB deletion. Furthermore, human neutrophils exposed to the S. sanguinis wild-type strain, in contrast to those exposed to an spxB mutant strain, underwent cell death with chromatin de-condensation and release of web-like extracellular DNA, reflecting induction of neutrophil extracellular traps (NETs. Since reactive oxygen species-mediated NET induction requires citrullination of arginine residues in histone proteins and subsequent chromatin de-condensation, we examined citrullination levels of histone in infected neutrophils. It is important to note that the citrullinated histone H3 was readily detected in neutrophils infected with the wild-type strain, as compared to infection with the spxB mutant strain. Moreover, decomposition of streptococcal H2O2 with catalase reduced NET induction. These results suggest that H2O2 produced by S. sanguinis provokes cell death of neutrophils and NET formation, thus potentially affecting bacterial survival in the bloodstream.

  18. Cell Death Biomarkers and Obstructive Sleep Apnea: Implications in the Acute Coronary Syndrome.

    Science.gov (United States)

    Bauça, Josep Miquel; Yañez, Aina; Fueyo, Laura; de la Peña, Mónica; Pierola, Javier; Sánchez-de-la-Torre, Alicia; Mediano, Olga; Cabriada-Nuño, Valentín; Masdeu, María José; Teran-Santos, Joaquin; Duran-Cantolla, Joaquin; Masa, Juan Fernando; Abad, Jorge; Sanchez-de-la-Torre, Manuel; Barbé, Ferran; Barceló, Antònia

    2017-05-01

    Nucleosomes and cell-free double-stranded DNA (dsDNA) have been suggested as promising biomarkers in cell death-related diseases, such as acute coronary syndrome (ACS). Currently, the impact of obstructive sleep apnea (OSA) in patients with ACS is unclear. Our aim was to evaluate the relationship between OSA, dsDNA, and nucleosomes and to assess their potential implication in the development of ACS. Up to 549 patients were included in the study and divided into four groups (145 ACS; 290 ACS + OSA; 62 OSA; 52 controls). All patients underwent a sleep study, and serum concentrations of dsDNA and nucleosomes were measured. Nucleosome and dsDNA levels were higher in patients with OSA than in controls (nucleosomes: 1.47 ± 0.88 arbitary units [AU] vs. 1.00 ± 0.33 AU; p Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

  19. Ezrin dephosphorylation/downregulation contributes to ursolic acid-mediated cell death in human leukemia cells

    International Nuclear Information System (INIS)

    Li, G; Zhou, T; Liu, L; Chen, J; Zhao, Z; Peng, Y; Li, P; Gao, N

    2013-01-01

    Ezrin links the actin filaments with the cell membrane and has a functional role in the apoptotic process. It appears clear that ezrin is directly associated with Fas, leading to activation of caspase cascade and cell death. However, the exact role of ezrin in ursolic acid (UA)-induced apoptosis remains unclear. In this study, we show for the first time that UA induces apoptosis in both transformed and primary leukemia cells through dephosphorylation/downregulation of ezrin, association and polarized colocalization of Fas and ezrin, as well as formation of death-inducing signaling complex. These events are dependent on Rho-ROCK1 signaling pathway. Knockdown of ezrin enhanced cell death mediated by UA, whereas overexpression of ezrin attenuated UA-induced apoptosis. Our in vivo study also showed that UA-mediated inhibition of tumor growth of mouse leukemia xenograft model is in association with the dephosphorylation/downregulation of ezrin. Such findings suggest that the cytoskeletal protein ezrin may represent an attractive target for UA-mediated lethality in human leukemia cells

  20. Chloroplasts activity and PAP-signaling regulate programmed cell death in Arabidopsis

    KAUST Repository

    Bruggeman, Quentin; Mazubert, Christelle; Prunier, Florence; Lugan, Raphael; Chan, Kai Xun; Phua, Su Yin; Pogson, Barry J.; Krieger-Liszkay, Anja; Delarue, Marianne; Benhamed, Moussa; Bergounioux, Catherine; Raynaud, Cé cile

    2016-01-01

    Programmed cell death (PCD) is a crucial process both for plant development and responses to biotic and abiotic stress. There is accumulating evidence that chloroplasts may play a central role during plant PCD as for mitochondria in animal cells

  1. Effect of Transient Maternal Hypotension on Apoptotic Cell Death in Foetal Rat Brain

    Directory of Open Access Journals (Sweden)

    Hamit Özyürek

    2014-03-01

    Full Text Available Background: Intrauterine perfusion insufficiency induced by transient maternal hypotension has been reported to be associated with foetal brain malformations. However, the effects of maternal hypotension on apoptotic processes in the foetal brain have not been investigated experimentally during the intrauterine period. Aims: The aim of this study was to investigate the effects of transient maternal hypotension on apoptotic cell death in the intrauterine foetal brain. Study Design: Animal experimentation. Methods: Three-month-old female Wistar albino rats were allocated into four groups (n=5 each. The impact of hypoxic/ischemic injury induced by transient maternal hypotension on the 15th day of pregnancy (late gestation in rats was investigated at 48 (H17 group or 96 hours (H19 group after the insult. Control groups underwent the same procedure except for induction of hypotension (C17 and H17 groups. Brain sections of one randomly selected foetus from each pregnant rat were histopathologically evaluated for hypoxic/ischemic injury in the metencephalon, diencephalon, and telencephalon by terminal transferase-mediated dUTP nick end labelling and active cysteine-dependent aspartate-directed protease-3 (caspase-3 positivity for cell death. Results: The number of terminal transferase-mediated dUTP nick end labelling (+ cells in all the areas examined was comparable in both hypotension and control groups. The H17 group had active caspase-3 (+ cells in the metencephalon and telencephalon, sparing diencephalon, whereas the C19 and H19 groups had active caspase-3 (+ cells in all three regions. The number of active caspase-3 (+ cells in the telencephalon in the H19 group was higher compared with the metencephalon and diencephalon and compared with H17 group (p<0.05. Conclusion: Our results suggest that prenatal hypoxic/ischemic injury triggers apoptotic mechanisms. Therefore, blockade of apoptotic pathways, considering the time pattern of the insult, may

  2. Modulation of genes involved in inflammation and cell death in atherosclerosis-susceptible mice

    NARCIS (Netherlands)

    Zadelaar, Anna Susanne Maria

    2006-01-01

    In this thesis we focus on atherosclerosis as the main cause of cardiovascular disease. Since inflammation and cell death are important processes in the onset and progression of atherosclerosis, we investigate the role of several genes involved in inflammation and cell death in the vessel wall and

  3. Guidelines for the use and interpretation of assays for monitoring cell death in higher eukaryotes

    NARCIS (Netherlands)

    Galluzzi, L.; Aaronson, S. A.; Abrams, J.; Alnemri, E. S.; Andrews, D. W.; Baehrecke, E. H.; Bazan, N. G.; Blagosklonny, M. V.; Blomgren, K.; Borner, C.; Bredesen, D. E.; Brenner, C.; Castedo, M.; Cidlowski, J. A.; Ciechanover, A.; Cohen, G. M.; de Laurenzi, V.; de Maria, R.; Deshmukh, M.; Dynlacht, B. D.; El-Deiry, W. S.; Flavell, R. A.; Fulda, S.; Garrido, C.; Golstein, P.; Gougeon, M.-L.; Green, D. R.; Gronemeyer, H.; Hajnóczky, G.; Hardwick, J. M.; Hengartner, M. O.; Ichijo, H.; Jäättelä, M.; Kepp, O.; Kimchi, A.; Klionsky, D. J.; Knight, R. A.; Kornbluth, S.; Kumar, S.; Levine, B.; Lipton, S. A.; Lugli, E.; Madeo, F.; Malorni, W.; Marine, J.-Cw; Martin, S. J.; Medema, J. P.; Mehlen, P.; Melino, G.; Moll, U. M.; Morselli, E.; Nagata, S.; Nicholson, D. W.; Nicotera, P.; Nuñez, G.; Oren, M.; Penninger, J.; Pervaiz, S.; Peter, M. E.; Piacentini, M.; Prehn, J. H. M.; Puthalakath, H.; Rabinovich, G. A.; Rizzuto, R.; Rodrigues, C. M. P.; Rubinsztein, D. C.; Rudel, T.; Scorrano, L.; Simon, H.-U.; Steller, H.; Tschopp, J.; Tsujimoto, Y.; Vandenabeele, P.; Vitale, I.; Vousden, K. H.; Youle, R. J.; Yuan, J.; Zhivotovsky, B.; Kroemer, G.

    2009-01-01

    Cell death is essential for a plethora of physiological processes, and its deregulation characterizes numerous human diseases. Thus, the in-depth investigation of cell death and its mechanisms constitutes a formidable challenge for fundamental and applied biomedical research, and has tremendous

  4. Triglyceride-induced macrophage cell death is triggered by caspase-1.

    Science.gov (United States)

    Son, Sin Jee; Rhee, Ki-Jong; Lim, Jaewon; Kim, Tae Ue; Kim, Tack-Joong; Kim, Yoon Suk

    2013-01-01

    Triglyceride (TG) induces macrophage cell death which contributes to the development of atherosclerosis. We confirmed that exogenous TG accumulates in human THP-1 macrophages and causes cell death. TG treated THP-1 macrophages exhibited no change in tumor necrosis factor (TNF)-α, interleukin (IL)-18, macrophage inflammatory protein (MIP)-1α, and IL-1R1 receptor mRNA expression. However, there was a marked decrease in IL-1β mRNA expression but an increase in IL-1β protein secretion. Decreased expression of IL-1β mRNA and increased secretion of IL-1β protein was not the direct cause of cell death. Until now, TG was assumed to induce necrotic cell death in macrophages. Since caspase-1 is known to be involved in activation and secretion of IL-1β protein and pyroptotic cell death, next we determined whether caspase-1 is associated with TG-induced macrophage cell death. We found an increase in caspase-1 activity in TG-treated THP-1 macrophages and inhibition of caspase-1 activity using a specific inhibitor partially rescued cell death. These results suggest activation of the pyroptotic pathway by TG. This is the first report implicating the activation of caspase-1 and the triggering of the pyroptosis pathway in TG-induced macrophage cell death.

  5. Secretory phospholipase A2-mediated neuronal cell death involves glutamate ionotropic receptors

    DEFF Research Database (Denmark)

    Kolko, Miriam; de Turco, Elena B; Diemer, Nils Henrik

    2002-01-01

    To define the significance of glutamate ionotropic receptors in sPLA -mediated neuronal cell death we used the NMDA receptor antagonist MK-801 and the AMPA receptor antagonist PNQX. In primary neuronal cell cultures both MK-801 and PNQX inhibited sPLA - and glutamate-induced neuronal death. [ H...

  6. Barium inhibits arsenic-mediated apoptotic cell death in human squamous cell carcinoma cells.

    Science.gov (United States)

    Yajima, Ichiro; Uemura, Noriyuki; Nizam, Saika; Khalequzzaman, Md; Thang, Nguyen D; Kumasaka, Mayuko Y; Akhand, Anwarul A; Shekhar, Hossain U; Nakajima, Tamie; Kato, Masashi

    2012-06-01

    Our fieldwork showed more than 1 μM (145.1 μg/L) barium in about 3 μM (210.7 μg/L) arsenic-polluted drinking well water (n = 72) in cancer-prone areas in Bangladesh, while the mean concentrations of nine other elements in the water were less than 3 μg/L. The types of cancer include squamous cell carcinomas (SCC). We hypothesized that barium modulates arsenic-mediated biological effects, and we examined the effect of barium (1 μM) on arsenic (3 μM)-mediated apoptotic cell death of human HSC-5 and A431 SCC cells in vitro. Arsenic promoted SCC apoptosis with increased reactive oxygen species (ROS) production and JNK1/2 and caspase-3 activation (apoptotic pathway). In contrast, arsenic also inhibited SCC apoptosis with increased NF-κB activity and X-linked inhibitor of apoptosis protein (XIAP) expression level and decreased JNK activity (antiapoptotic pathway). These results suggest that arsenic bidirectionally promotes apoptotic and antiapoptotic pathways in SCC cells. Interestingly, barium in the presence of arsenic increased NF-κB activity and XIAP expression and decreased JNK activity without affecting ROS production, resulting in the inhibition of the arsenic-mediated apoptotic pathway. Since the anticancer effect of arsenic is mainly dependent on cancer apoptosis, barium-mediated inhibition of arsenic-induced apoptosis may promote progression of SCC in patients in Bangladesh who keep drinking barium and arsenic-polluted water after the development of cancer. Thus, we newly showed that barium in the presence of arsenic might inhibit arsenic-mediated cancer apoptosis with the modulation of the balance between arsenic-mediated promotive and suppressive apoptotic pathways.

  7. Murraya koenigii leaf extract inhibits proteasome activity and induces cell death in breast cancer cells

    Directory of Open Access Journals (Sweden)

    Noolu Bindu

    2013-01-01

    Full Text Available Abstract Background Inhibition of the proteolytic activity of 26S proteasome, the protein-degrading machine, is now considered a novel and promising approach for cancer therapy. Interestingly, proteasome inhibitors have been demonstrated to selectively kill cancer cells and also enhance the sensitivity of tumor cells to chemotherapeutic agents. Recently, polyphenols/flavonoids have been reported to inhibit proteasome activity. Murraya koenigii Spreng, a medicinally important herb of Indian origin, has been used for centuries in the Ayurvedic system of medicine. Here we show that Murraya koenigii leaves (curry leaves, a rich source of polyphenols, inhibit the proteolytic activity of the cancer cell proteasome, and cause cell death. Methods Hydro-methanolic extract of curry leaves (CLE was prepared and its total phenolic content [TPC] determined by, the Folin-Ciocalteau’s method. Two human breast carcinoma cell lines: MCF-7 and MDA-MB-231 and a normal human lung fibroblast cell line, WI-38 were used for the studies. Cytotoxicity of the CLE was assessed by the MTT assay. We studied the effect of CLE on growth kinetics using colony formation assay. Growth arrest was assessed by cell cycle analysis and apoptosis by Annexin-V binding using flow cytometry. Inhibition of the endogenous 26S proteasome was studied in intact cells and cell extracts using substrates specific to 20S proteasomal enzymes. Results CLE decreased cell viability and altered the growth kinetics in both the breast cancer cell lines in a dose-dependent manner. It showed a significant arrest of cells in the S phase albeit in cancer cells only. Annexin V binding data suggests that cell death was via the apoptotic pathway in both the cancer cell lines. CLE treatment significantly decreased the activity of the 26S proteasome in the cancer but not normal cells. Conclusions Our study suggests M. koenigii leaves to be a potent source of proteasome inhibitors that lead to cancer cell death

  8. Murraya koenigii leaf extract inhibits proteasome activity and induces cell death in breast cancer cells.

    Science.gov (United States)

    Noolu, Bindu; Ajumeera, Rajanna; Chauhan, Anitha; Nagalla, Balakrishna; Manchala, Raghunath; Ismail, Ayesha

    2013-01-09

    Inhibition of the proteolytic activity of 26S proteasome, the protein-degrading machine, is now considered a novel and promising approach for cancer therapy. Interestingly, proteasome inhibitors have been demonstrated to selectively kill cancer cells and also enhance the sensitivity of tumor cells to chemotherapeutic agents. Recently, polyphenols/flavonoids have been reported to inhibit proteasome activity. Murraya koenigii Spreng, a medicinally important herb of Indian origin, has been used for centuries in the Ayurvedic system of medicine. Here we show that Murraya koenigii leaves (curry leaves), a rich source of polyphenols, inhibit the proteolytic activity of the cancer cell proteasome, and cause cell death. Hydro-methanolic extract of curry leaves (CLE) was prepared and its total phenolic content [TPC] determined by, the Folin-Ciocalteau's method. Two human breast carcinoma cell lines: MCF-7 and MDA-MB-231 and a normal human lung fibroblast cell line, WI-38 were used for the studies. Cytotoxicity of the CLE was assessed by the MTT assay. We studied the effect of CLE on growth kinetics using colony formation assay. Growth arrest was assessed by cell cycle analysis and apoptosis by Annexin-V binding using flow cytometry. Inhibition of the endogenous 26S proteasome was studied in intact cells and cell extracts using substrates specific to 20S proteasomal enzymes. CLE decreased cell viability and altered the growth kinetics in both the breast cancer cell lines in a dose-dependent manner. It showed a significant arrest of cells in the S phase albeit in cancer cells only. Annexin V binding data suggests that cell death was via the apoptotic pathway in both the cancer cell lines. CLE treatment significantly decreased the activity of the 26S proteasome in the cancer but not normal cells. Our study suggests M. koenigii leaves to be a potent source of proteasome inhibitors that lead to cancer cell death. Therefore, identification of active component(s) from the leaf

  9. Gene expression analysis of cell death induction by Taurolidine in different malignant cell lines

    International Nuclear Information System (INIS)

    Chromik, Ansgar M; Weyhe, Dirk; Mittelkötter, Ulrich; Uhl, Waldemar; Hahn, Stephan A; Daigeler, Adrien; Flier, Annegret; Bulut, Daniel; May, Christina; Harati, Kamran; Roschinsky, Jan; Sülberg, Dominique

    2010-01-01

    The anti-infective agent Taurolidine (TRD) has been shown to have cell death inducing properties, but the mechanism of its action is largely unknown. The aim of this study was to identify potential common target genes modulated at the transcriptional level following TRD treatment in tumour cell lines originating from different cancer types. Five different malignant cell lines (HT29, Chang Liver, HT1080, AsPC-1 and BxPC-3) were incubated with TRD (100 μM, 250 μM and 1000 μM). Proliferation after 8 h and cell viability after 24 h were analyzed by BrdU assay and FACS analysis, respectively. Gene expression analyses were carried out using the Agilent -microarray platform to indentify genes which displayed conjoint regulation following the addition of TRD in all cell lines. Candidate genes were subjected to Ingenuity Pathways Analysis and selected genes were validated by qRT-PCR and Western Blot. TRD 250 μM caused a significant inhibition of proliferation as well as apoptotic cell death in all cell lines. Among cell death associated genes with the strongest regulation in gene expression, we identified pro-apoptotic transcription factors (EGR1, ATF3) as well as genes involved in the ER stress response (PPP1R15A), in ubiquitination (TRAF6) and mitochondrial apoptotic pathways (PMAIP1). This is the first conjoint analysis of potential target genes of TRD which was performed simultaneously in different malignant cell lines. The results indicate that TRD might be involved in different signal transduction pathways leading to apoptosis

  10. Armet, a UPR-upregulated protein, inhibits cell proliferation and ER stress-induced cell death

    International Nuclear Information System (INIS)

    Apostolou, Andria; Shen Yuxian; Liang Yan; Luo Jun; Fang Shengyun

    2008-01-01

    The accumulation of misfolded proteins in the endoplasmic reticulum (ER) causes ER stress that initiates the unfolded protein response (UPR). UPR activates both adaptive and apoptotic pathways, which contribute differently to disease pathogenesis. To further understand the functional mechanisms of UPR, we identified 12 commonly UPR-upregulated genes by expression microarray analysis. Here, we describe characterization of Armet/MANF, one of the 12 genes whose function was not clear. We demonstrated that the Armet/MANF protein was upregulated by various forms of ER stress in several cell lines as well as by cerebral ischemia of rat. Armet/MANF was localized in the ER and Golgi and was also a secreted protein. Silencing Armet/MANF by siRNA oligos in HeLa cells rendered cells more susceptible to ER stress-induced death, but surprisingly increased cell proliferation and reduced cell size. Overexpression of Armet/MANF inhibited cell proliferation and improved cell viability under glucose-free conditions and tunicamycin treatment. Based on its inhibitory properties for both proliferation and cell death we have demonstrated, Armet is, thus, a novel secreted mediator of the adaptive pathway of UPR

  11. Protein Kinase G facilitates EGFR-mediated cell death in MDA-MB-468 cells

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, Nicole M.; Ceresa, Brian P., E-mail: brian.ceresa@louisville.edu

    2016-08-15

    The Epidermal Growth Factor Receptor (EGFR) is a transmembrane receptor tyrosine kinase with critical implications in cell proliferation, migration, wound healing and the regulation of apoptosis. However, the EGFR has been shown to be hyper-expressed in a number of human malignancies. The MDA-MB-468 metastatic breast cell line is one example of this. This particular cell line hyper-expresses the EGFR and undergoes EGFR-mediated apoptosis in response to EGF ligand. The goal of this study was to identify the kinases that could be potential intermediates for the EGFR-mediated induction of apoptosis intracellularly. After identifying Cyclic GMP-dependent Protein Kinase G (PKG) as a plausible intermediate, we wanted to determine the temporal relationship of these two proteins in the induction of apoptosis. We observed a dose-dependent decrease in MDA-MB-468 cell viability, which was co-incident with increased PKG activity as measured by VASPSer239 phosphorylation. In addition, we observed a dose dependent decrease in cell viability, as well as an increase in apoptosis, in response to two different PKG agonists, 8-Bromo-cGMP and 8-pCPT-cGMP. MDA-MB-468 cells with reduced PKG activity had attenuated EGFR-mediated apoptosis. These findings indicate that PKG does not induce cell death via transphosphorylation of the EGFR. Instead, PKG activity occurs following EGFR activation. Together, these data indicate PKG as an intermediary in EGFR-mediated cell death, likely via apoptotic pathway.

  12. Spontaneous and radiation induced cell death in HeLa S3 human carcinoma

    International Nuclear Information System (INIS)

    Zaric, B.; Milosavljevic, B.; Radojcic, M.

    2001-01-01

    Radiation biologists have classified radiation-induced cell death based on cell proliferative capacity to either mitotic or interphase death. Cytologists have revealed two morphologically and biochemically diverse forms of cell death, apoptosis and necrosis. While the knowledge of the former is already well exploited by radiologists, cell susceptibility to apoptosis and necrosis is still under investigation. We studied characteristics of spontaneous cell death, and dose dependence and time course of radiation-induced cell death of human uterine cervix epitheloid carcinoma HeLaS 3 in culture. Cells were irradiated with 2-40 Gy of γ-rays. The effect on growth, viability, morphology and genomic DNA structure were followed 24-72 h after irradiation. Cell viability was evaluated by trypan-blue exclusion assay and cell morphology by in situ DNA staining with propidium iodide. Cell genomic DNA fragmentation pattern was determined by electrophoresis on 2% agarose gels. At all cell densities 25-35% cells were PI positive and their DNA was fragmented to a high molecular size (≥20 kbp), but the internucleosomal ladder was not observed. A significant decrease in viability to 33% was observed 72 h post 40 Gy irradiation. It corresponded to 55% of PI positive cells. A smear of smaller DNA fragments (0.1-1 kbp), 24 h after 10-20 Gy irradiation was considered as proof that the dominant form of radiation-induced cell death was necrosis. It was concluded that the dominant form of radiation-induced cell death in HeLaS 3 population was necrosis and the radiation dose which caused 50% of cell death after 72 h (termed ND 50 ) was between 30-40 Gy. (author)

  13. Non-Cell Autonomous Influence of the Astrocyte System xc − on Hypoglycaemic Neuronal Cell Death

    Directory of Open Access Journals (Sweden)

    Nicole A Jackman

    2012-01-01

    Full Text Available Despite longstanding evidence that hypoglycaemic neuronal injury is mediated by glutamate excitotoxicity, the cellular and molecular mechanisms involved remain incompletely defined. Here, we demonstrate that the excitotoxic neuronal death that follows GD (glucose deprivation is initiated by glutamate extruded from astrocytes via system xc −– – an amino acid transporter that imports L-cystine and exports L-glutamate. Specifically, we find that depriving mixed cortical cell cultures of glucose for up to 8 h injures neurons, but not astrocytes. Neuronal death is prevented by ionotropic glutamate receptor antagonism and is partially sensitive to tetanus toxin. Removal of amino acids during the deprivation period prevents – whereas addition of L-cystine restores – GD-induced neuronal death, implicating the cystine/glutamate antiporter, system xc−–. Indeed, drugs known to inhibit system xc −– ameliorate GD-induced neuronal death. Further, a dramatic reduction in neuronal death is observed in chimaeric cultures consisting of neurons derived from WT (wild-type mice plated on top of astrocytes derived from sut mice, which harbour a naturally occurring null mutation in the gene (Slc7a11 that encodes the substrate-specific light chain of system xc −– (xCT. Finally, enhancement of astrocytic system xc −– expression and function via IL-1β (interleukin-1β exposure potentiates hypoglycaemic neuronal death, the process of which is prevented by removal of L-cystine and/or addition of system xc −– inhibitors. Thus, under the conditions of GD, our studies demonstrate that astrocytes, via system xc −–, have a direct, non-cell autonomous effect on cortical neuron survival.

  14. HAMLET triggers apoptosis but tumor cell death is independent of caspases, Bcl-2 and p53.

    Science.gov (United States)

    Hallgren, O; Gustafsson, L; Irjala, H; Selivanova, G; Orrenius, S; Svanborg, C

    2006-02-01

    HAMLET (Human alpha-lactalbumin Made Lethal to Tumor cells) triggers selective tumor cell death in vitro and limits tumor progression in vivo. Dying cells show features of apoptosis but it is not clear if the apoptotic response explains tumor cell death. This study examined the contribution of apoptosis to cell death in response to HAMLET. Apoptotic changes like caspase activation, phosphatidyl serine externalization, chromatin condensation were detected in HAMLET-treated tumor cells, but caspase inhibition or Bcl-2 over-expression did not prolong cell survival and the caspase response was Bcl-2 independent. HAMLET translocates to the nuclei and binds directly to chromatin, but the death response was unrelated to the p53 status of the tumor cells. p53 deletions or gain of function mutations did not influence the HAMLET sensitivity of tumor cells. Chromatin condensation was partly caspase dependent, but apoptosis-like marginalization of chromatin was also observed. The results show that tumor cell death in response to HAMLET is independent of caspases, p53 and Bcl-2 even though HAMLET activates an apoptotic response. The use of other cell death pathways allows HAMLET to successfully circumvent fundamental anti-apoptotic strategies that are present in many tumor cells.

  15. Cell death induced by taxanes in breast cancer cells: cytochrome C is released in resistant but not in sensitive cells

    Czech Academy of Sciences Publication Activity Database

    Ehrlichová, Marie; Koc, Michal; Truksa, Jaroslav; Naďová, Zuzana; Václavíková, R.; Kovář, Jan

    2005-01-01

    Roč. 25, 6B (2005), s. 4215-4224 ISSN 0250-7005 R&D Projects: GA MZd(CZ) NL7567 Institutional research plan: CEZ:AV0Z50520514 Keywords : paclitaxel * cell death * breast cancer cells Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.604, year: 2005

  16. Simulation of Cell Patterning Triggered by Cell Death and Differential Adhesion in Drosophila Wing.

    Science.gov (United States)

    Nagai, Tatsuzo; Honda, Hisao; Takemura, Masahiko

    2018-02-27

    The Drosophila wing exhibits a well-ordered cell pattern, especially along the posterior margin, where hair cells are arranged in a zigzag pattern in the lateral view. Based on an experimental result observed during metamorphosis of Drosophila, we considered that a pattern of initial cells autonomously develops to the zigzag pattern through cell differentiation, intercellular communication, and cell death (apoptosis) and performed computer simulations of a cell-based model of vertex dynamics for tissues. The model describes the epithelial tissue as a monolayer cell sheet of polyhedral cells. Their vertices move according to equations of motion, minimizing the sum total of the interfacial and elastic energies of cells. The interfacial energy densities between cells are introduced consistently with an ideal zigzag cell pattern, extracted from the experimental result. The apoptosis of cells is modeled by gradually reducing their equilibrium volume to zero and by assuming that the hair cells prohibit neighboring cells from undergoing apoptosis. Based on experimental observations, we also assumed wing elongation along the proximal-distal axis. Starting with an initial cell pattern similar to the micrograph experimentally obtained just before apoptosis, we carried out the simulations according to the model mentioned above and successfully reproduced the ideal zigzag cell pattern. This elucidates a physical mechanism of patterning triggered by cell apoptosis theoretically and exemplifies, to our knowledge, a new framework to study apoptosis-induced patterning. We conclude that the zigzag cell pattern is formed by an autonomous communicative process among the participant cells. Copyright © 2018 Biophysical Society. All rights reserved.

  17. The mechanism of radiation-induced interphase death of lymphoid cells: A new hypothesis

    International Nuclear Information System (INIS)

    Eidus, L.K.; Korystov, Yu.N.; Dobrovinskaja, O.R.; Shaposhnikova, V.V.

    1990-01-01

    The interphase death of irradiated rat thymocytes depends on their concentration during postirradiation incubation. The kinetics of pycnosis and cell death determined with the trypan blue exclusion test in the samples with the highest cell concentration (1-2 x 10(7) cells/ml) is consistent with the data available in the literature, whereas the samples with the lowest concentration (2 x 10(5) cells/ml) undergo almost no pycnosis and death after irradiation with doses up to 50 Gy. On the basis of these results, we suggest a new mechanism of interphase death involving an interaction between irradiated thymocytes and the fraction of thymus cells possessing cytocidal activity. The observed correlation between the cytocidal activity and interphase death of thymocytes from animals of different ages favors our mechanism. It was found that the inhibitors which prevent the conjugation of killer cells and their targets do not influence interphase death, while the substances which block the secretion of cytotoxic factors or their action on the target membrane do protect from interphase death. Thus we suggest that the irradiation activates the killer cells to secrete some cytotoxic factors which induce pycnosis and interphase death of thymocytes

  18. HOIP Deficiency Causes Embryonic Lethality by Aberrant TNFR1-Mediated Endothelial Cell Death

    Directory of Open Access Journals (Sweden)

    Nieves Peltzer

    2014-10-01

    Full Text Available Summary: Linear ubiquitination is crucial for innate and adaptive immunity. The linear ubiquitin chain assembly complex (LUBAC, consisting of HOIL-1, HOIP, and SHARPIN, is the only known ubiquitin ligase that generates linear ubiquitin linkages. HOIP is the catalytically active LUBAC component. Here, we show that both constitutive and Tie2-Cre-driven HOIP deletion lead to aberrant endothelial cell death, resulting in defective vascularization and embryonic lethality at midgestation. Ablation of tumor necrosis factor receptor 1 (TNFR1 prevents cell death, vascularization defects, and death at midgestation. HOIP-deficient cells are more sensitive to death induction by both tumor necrosis factor (TNF and lymphotoxin-α (LT-α, and aberrant complex-II formation is responsible for sensitization to TNFR1-mediated cell death in the absence of HOIP. Finally, we show that HOIP’s catalytic activity is necessary for preventing TNF-induced cell death. Hence, LUBAC and its linear-ubiquitin-forming activity are required for maintaining vascular integrity during embryogenesis by preventing TNFR1-mediated endothelial cell death. : HOIP is the main catalytic subunit of the linear ubiquitin chain assembly complex (LUBAC, a crucial regulator of TNF and other immune signaling pathways. Peltzer et al. find that HOIP deficiency results in embryonic lethality at midgestation due to endothelial cell death mediated by TNFR1. Aberrant formation of a TNF-mediated cell-death-inducing complex in HOIP-deficient (but not -proficient cells underlies the phenotype, with the catalytic activity of HOIP required for the control of cell death in response to TNF.

  19. Cell death induced by Morarah and Khaltita in hepatoma cancer cells (Huh-7).

    Science.gov (United States)

    Baig, Saeeda; Alamgir, Mohiuddin

    2009-10-01

    To compare the combined and isolated growth inhibitory effects of Morarah and Khaltita (herbs) on hepatoma cell lines (Huh-7), through induction of apoptosis or necrosis. Comparative controlled in-vitro study. The Molecular Biology Laboratory, The Aga Khan University, Karachi, from June to December 2006. The growth of hepatoma cell lines (Huh-7) was checked by adding Khaltita and Morarah to the cells before culture in a 24 well plate. Six wells were selected and labeled for each of the four variables (controls, Khaltita, Morarah and mixture). After 2 days, cells were studied under an inverted phase contrast microscope and fields were recorded. Approximately four fields per slide of higher intensity were selected randomly to determine the dead cell density, and the procedure was repeated 10 or more times. Frequency and percentages were calculated for dead or alive cells in controls, Morarah, Khaltita and their mixture. Chi-square was used to compare the qualitative variables. P-values < 0.05 were considered significant. Morarah and Khaltita were found to induce statistically significant (p < 0.001) cell death in hepatoma cell lines (Huh-7). At a magnification of 40x, the controls showed 1% dead cells compared to 91% in Morarah, 83% in Khaltita and 73% in combined mixture of Khaltita and Morarah. At magnification of 20x, the controls showed 4% dead cells compared to 44% in Morarah, 47% in Khaltita and 49% in the combined mixture of Khaltita and Morarah. Morarah and Khaltita induced cell death in cultured hepatoma cells (Huh-7).

  20. Cytoprotective effects of fisetin against hypoxia-induced cell death in PC12 cells.

    Science.gov (United States)

    Chen, Pei-Yi; Ho, Yi-Ru; Wu, Ming-Jiuan; Huang, Shun-Ping; Chen, Po-Kong; Tai, Mi-Hsueh; Ho, Chi-Tang; Yen, Jui-Hung

    2015-01-01

    Fisetin (3,7,3',4'-tetrahydroxyflavone), a flavonol compound of flavonoids, exhibits a broad spectrum of biological activities including anti-oxidant, anti-inflammatory, anti-cancer and neuroprotective effects. The aim of this study is to investigate the cytoprotective effect of fisetin and the underlying molecular mechanism against hypoxia-induced cell death in PC12 cells. The results of this study showed that fisetin significantly restored the cell viability of PC12 cells under both cobalt chloride (CoCl₂)- and low oxygen-induced hypoxic conditions. Treatment with fisetin successfully reduced the CoCl₂-mediated reactive oxygen species (ROS) production, which was accompanied by an increase in the cell viability of PC12 cells. Furthermore, we found that treatment of PC12 cells with fisetin markedly upregulated hypoxia-inducible factor 1α (HIF-1α), its nuclear accumulation and the hypoxia-response element (HRE)-driven transcriptional activation. The fisetin-mediated cytoprotection during CoCl₂ exposure was significantly attenuated through the administration of HIF-1α siRNA. Moreover, we demonstrated that MAPK/ERK kinase 1/2 (MEK1/2), p38 MAPK and phosphatidylinositol 3-kinase (PI3 K) inhibitors significantly blocked the increase in cell survival that was induced by fisetin treatment under hypoxic conditions. Consistently, increased phosphorylation of ERK, p38 and Akt proteins was observed in PC12 cells treated with fisetin. However, the fisetin-induced HRE-driven transcription was not affected by inhibition of these kinase signaling pathways. Current results reveal for the first time that fisetin promotes cell survival and protects against hypoxia-induced cell death through ROS scavenging and the activation of HIF1α-, MAPK/ERK-, p38 MAPK- and PI3 K/Akt-dependent signaling pathways in PC12 cells.

  1. PKC activation induces inflammatory response and cell death in human bronchial epithelial cells.

    Directory of Open Access Journals (Sweden)

    Hyunhee Kim

    Full Text Available A variety of airborne pathogens can induce inflammatory responses in airway epithelial cells, which is a crucial component of host defence. However, excessive inflammatory responses and chronic inflammation also contribute to different diseases of the respiratory system. We hypothesized that the activation of protein kinase C (PKC is one of the essential mechanisms of inflammatory response in airway epithelial cells. In the present study, we stimulated human bronchial lung epithelial (BEAS-2B cells with the phorbol ester Phorbol 12, 13-dibutyrate (PDBu, and examined gene expression profile using microarrays. Microarray analysis suggests that PKC activation induced dramatic changes in gene expression related to multiple cellular functions. The top two interaction networks generated from these changes were centered on NFκB and TNF-α, which are two commonly known pathways for cell death and inflammation. Subsequent tests confirmed the decrease in cell viability and an increase in the production of various cytokines. Interestingly, each of the increased cytokines was differentially regulated at mRNA and/or protein levels by different sub-classes of PKC isozymes. We conclude that pathological cell death and cytokine production in airway epithelial cells in various situations may be mediated through PKC related signaling pathways. These findings suggest that PKCs can be new targets for treatment of lung diseases.

  2. Eclalbasaponin II induces autophagic and apoptotic cell death in human ovarian cancer cells

    Directory of Open Access Journals (Sweden)

    Yoon Jin Cho

    2016-09-01

    Full Text Available Triterpenoids echinocystic acid and its glycosides, isolated from several Eclipta prostrata, have been reported to possess various biological activities such as anti-inflammatory, anti-bacterial, and anti-diabetic activity. However, the cytotoxicity of the triterpenoids in human cancer cells and their molecular mechanism of action are poorly understood. In the present study, we found that eclalbasaponin II with one glucose moiety has potent cytotoxicity in three ovarian cancer cells and two endometrial cancer cells compared to an aglycone echinocystic acid and eclalbasaponin I with two glucose moiety. Eclalbasaponin II treatment dose-dependently increased sub G1 population. Annexin V staining revealed that eclalbasaponin II induced apoptosis in SKOV3 and A2780 ovarian cancer cells. In addition, eclalbasaponin II-induced cell death was associated with characteristics of autophagy; an increase in acidic vesicular organelle content and elevation of the levels of LC3-II. Interestingly, autophagy inhibitor BaF1 suppressed the eclalbasaponin II-induced apoptosis. Moreover, eclalbasaponin II activated JNK and p38 signaling and inhibited the mTOR signaling. We further demonstrated that pre-treatment with a JNK and p38 inhibitor and mTOR activator attenuated the eclalbasaponin II-induced autophagy. This suggests that eclalbasaponin II induces apoptotic and autophagic cell death through the regulation of JNK, p38, and mTOR signaling in human ovarian cancer cells.

  3. Lack of Both Nucleotide-Binding Oligomerization Domain-Containing Proteins 1 and 2 Primes T Cells for Activation-Induced Cell Death.

    Science.gov (United States)

    Kasimsetty, Sashi G; Shigeoka, Alana A; Scheinok, Andrew A; Gavin, Amanda L; Ulevitch, Richard J; McKay, Dianne B

    2017-08-01

    Nucleotide-binding oligomerization domain (Nod)-containing proteins Nod1 and Nod2 play important roles in the innate immune response to pathogenic microbes, but mounting data suggest these pattern recognition receptors might also play key roles in adaptive immune responses. Targeting Nod1 and Nod2 signaling pathways in T cells is likely to provide a new strategy to modify inflammation in a variety of disease states, particularly those that depend on Ag-induced T cell activation. To better understand how Nod1 and Nod2 proteins contribute to adaptive immunity, this study investigated their role in alloantigen-induced T cell activation and asked whether their absence might impact in vivo alloresponses using a severe acute graft versus host disease model. The study provided several important observations. We found that the simultaneous absence of Nod1 and Nod2 primed T cells for activation-induced cell death. T cells from Nod1 × 2 -/- mice rapidly underwent cell death upon exposure to alloantigen. The Nod1 × 2 -/- T cells had sustained p53 expression that was associated with downregulation of its negative regulator MDM2. In vivo, mice transplanted with an inoculum containing Nod1 × 2 -/- T cells were protected from severe graft versus host disease. The results show that the simultaneous absence of Nod1 and Nod2 is associated with accelerated T cell death upon alloantigen encounter, suggesting these proteins might provide new targets to ameliorate T cell responses in a variety of inflammatory states, including those associated with bone marrow or solid organ transplantation. Copyright © 2017 by The American Association of Immunologists, Inc.

  4. Combined effects of starvation and butyrate on autophagy-dependent gingival epithelial cell death.

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    Evans, M; Murofushi, T; Tsuda, H; Mikami, Y; Zhao, N; Ochiai, K; Kurita-Ochiai, T; Yamamoto, M; Otsuka, K; Suzuki, N

    2017-06-01

    Bacteria in the dental biofilm surrounding marginal gingival grooves cause periodontal diseases. Numerous bacteria within the biofilm consume nutrients from the gingival crevicular fluid. Furthermore, some gram-negative bacteria in mature dental biofilms produce butyrate. Thus, gingival epithelial cells in close proximity to mature dental biofilms are at risk of both starvation and exposure to butyrate. In the present study, we determined the combined effects of starvation and butyrate exposure on gingival epithelial cell death and the underlying mechanisms. The Ca9-22 cell line was used as an in vitro counterpart of gingival epithelial cells. Cell death was measured as the amount of total DNA in the dead cells using SYTOX Green dye, which penetrates through membranes of dead cells and emits fluorescence when it intercalates into double-stranded DNA. AMP-activated protein kinase (AMPK) activity, the amount of autophagy, and acetylation of histone H3 were determined using western blot. Gene expression levels of microtubule-associated protein 1 light chain 3b (lc3b) were determined using quantitative reverse transcription-polymerase chain reaction. Butyrate-induced cell death occurred in a dose-dependent manner whether cells were starved or fed. However, the induction of cell death was two to four times higher when cells were placed under starvation conditions compared to when they were fed. Moreover, both starvation and butyrate exposure induced AMPK activity and autophagy. While AMPK inactivation resulted in decreased autophagy and butyrate-induced cell death under conditions of starvation, AMPK activation resulted in butyrate-induced cell death when cells were fed. Combined with the results of our previous report, which demonstrated butyrate-induced autophagy-dependent cell death, the results of this study suggest that the combination of starvation and butyrate exposure activates AMPK inducing autophagy and subsequent cell death. Notably, this combination markedly

  5. Zebularine exerts its antiproliferative activity through S phase delay and cell death in human malignant mesothelioma cells.

    Science.gov (United States)

    Takemura, Yukitoshi; Satoh, Motohiko; Hatanaka, Kenichi; Kubota, Shunichiro

    2018-04-24

    Malignant mesothelioma is an asbestos-related aggressive tumor and current therapy remains ineffective. Zebularine as a DNA methyltransferase (DNMT) inhibitor has an anti-tumor effect in several human cancer cells. The aim of the present study was to investigate whether zebularine could induce antiproliferative effect in human malignant mesothelioma cells. Zebularine induced cell growth inhibition in a dose-dependent manner. In addition, zebularine dose-dependently decreased expression of DNMT1 in all malignant mesothelioma cells tested. Cell cycle analysis indicated that zebularine induced S phase delay. Zebularine also induced cell death in malignant mesothelioma cells. In contrast, zebularine did not induce cell growth inhibition and cell death in human normal fibroblast cells. These results suggest that zebularine has a potential for the treatment of malignant mesothelioma by inhibiting cell growth and inducing cell death.

  6. Genistein cooperates with the histone deacetylase inhibitor vorinostat to induce cell death in prostate cancer cells

    Directory of Open Access Journals (Sweden)

    Phillip Cornel J

    2012-04-01

    Full Text Available Abstract Background Among American men, prostate cancer is the most common, non-cutaneous malignancy that accounted for an estimated 241,000 new cases and 34,000 deaths in 2011. Previous studies have suggested that Wnt pathway inhibitory genes are silenced by CpG hypermethylation, and other studies have suggested that genistein can demethylate hypermethylated DNA. Genistein is a soy isoflavone with diverse effects on cellular proliferation, survival, and gene expression that suggest it could be a potential therapeutic agent for prostate cancer. We undertook the present study to investigate the effects of genistein on the epigenome of prostate cancer cells and to discover novel combination approaches of other compounds with genistein that might be of translational utility. Here, we have investigated the effects of genistein on several prostate cancer cell lines, including the ARCaP-E/ARCaP-M model of the epithelial to mesenchymal transition (EMT, to analyze effects on their epigenetic state. In addition, we investigated the effects of combined treatment of genistein with the histone deacetylase inhibitor vorinostat on survival in prostate cancer cells. Methods Using whole genome expression profiling and whole genome methylation profiling, we have determined the genome-wide differences in genetic and epigenetic responses to genistein in prostate cancer cells before and after undergoing the EMT. Also, cells were treated with genistein, vorinostat, and combination treatment, where cell death and cell proliferation was determined. Results Contrary to earlier reports, genistein did not have an effect on CpG methylation at 20 μM, but it did affect histone H3K9 acetylation and induced increased expression of histone acetyltransferase 1 (HAT1. In addition, genistein also had differential effects on survival and cooperated with the histone deacteylase inhibitor vorinostat to induce cell death and inhibit proliferation. Conclusion Our results suggest that

  7. Acadesine kills chronic myelogenous leukemia (CML cells through PKC-dependent induction of autophagic cell death.

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    Guillaume Robert

    Full Text Available CML is an hematopoietic stem cell disease characterized by the t(9;22 (q34;q11 translocation encoding the oncoprotein p210BCR-ABL. The effect of acadesine (AICAR, 5-Aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside a compound with known antileukemic effect on B cell chronic lymphoblastic leukemia (B-CLL was investigated in different CML cell lines. Acadesine triggered loss of cell metabolism in K562, LAMA-84 and JURL-MK1 and was also effective in killing imatinib-resistant K562 cells and Ba/F3 cells carrying the T315I-BCR-ABL mutation. The anti-leukemic effect of acadesine did not involve apoptosis but required rather induction of autophagic cell death. AMPK knock-down by Sh-RNA failed to prevent the effect of acadesine, indicating an AMPK-independent mechanism. The effect of acadesine was abrogated by GF109203X and Ro-32-0432, both inhibitor of classical and new PKCs and accordingly, acadesine triggered relocation and activation of several PKC isoforms in K562 cells. In addition, this compound exhibited a potent anti-leukemic effect in clonogenic assays of CML cells in methyl cellulose and in a xenograft model of K562 cells in nude mice. In conclusion, our work identifies an original and unexpected mechanism by which acadesine triggers autophagic cell death through PKC activation. Therefore, in addition to its promising effects in B-CLL, acadesine might also be beneficial for Imatinib-resistant CML patients.

  8. Nitric oxide modulates cadmium influx during cadmium-induced programmed cell death in tobacco BY-2 cells.

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    Ma, Wenwen; Xu, Wenzhong; Xu, Hua; Chen, Yanshan; He, Zhenyan; Ma, Mi

    2010-07-01

    Nitric oxide (NO) is a bioactive gas and functions as a signaling molecule in plants exposed to diverse biotic and abiotic stresses including cadmium (Cd(2+)). Cd(2+) is a non-essential and toxic heavy metal, which has been reported to induce programmed cell death (PCD) in plants. Here, we investigated the role of NO in Cd(2+)-induced PCD in tobacco BY-2 cells (Nicotiana tabacum L. cv. Bright Yellow 2). In this work, BY-2 cells exposed to 150 microM CdCl(2) underwent PCD with TUNEL-positive nuclei, significant chromatin condensation and the increasing expression of a PCD-related gene Hsr203J. Accompanied with the occurring of PCD, the production of NO increased significantly. The supplement of NO by sodium nitroprusside (SNP) had accelerated the PCD, whereas the NO synthase inhibitor Nomega-nitro-L-arginine methyl ester hydrochloride (L-NAME) and NO-specific scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO) alleviated this toxicity. To investigate the mechanism by which NO exerted its function, Cd(2+) concentration was measured subsequently. SNP led more Cd(2+) content than Cd(2+) treatment alone. By contrast, the prevention of NO by L-NAME decreased Cd(2+) accumulation. Using the scanning ion-selective electrode technique, we analyzed the pattern and rate of Cd(2+) fluxes. This analysis revealed the promotion of Cd(2+) influxes into cells by application of SNP, while L-NAME and cPTIO reduced the rate of Cd(2+) uptake or even resulted in net Cd(2+) efflux. Based on these founding, we concluded that NO played a positive role in CdCl(2)-induced PCD by modulating Cd(2+) uptake and thus promoting Cd(2+) accumulation in BY-2 cells.

  9. Vitamin K3 triggers human leukemia cell death through hydrogen peroxide generation and histone hyperacetylation.

    Science.gov (United States)

    Lin, Changjun; Kang, Jiuhong; Zheng, Rongliang

    2005-10-01

    Vitamin K3 (VK3) is a well-known anticancer agent, but its mechanism remains elusive. In the present study, VK3 was found to simultaneously induce cell death, reactive oxygen species (ROS) generation, including superoxide anion (O2*-) and hydrogen peroxide (H2O2) generation, and histone hyperacetylation in human leukemia HL-60 cells in a concentration- and time-dependent manner. Catalase (CAT), an antioxidant enzyme that specifically scavenges H2O2, could significantly diminish both histone acetylation increase and cell death caused by VK3, whereas superoxide dismutase (SOD), an enzyme that specifically eliminates O2*-, showed no effect on both of these, leading to the conclusion that H2O2 generation, but not O2*- generation, contributes to VK3-induced histone hyperacetylation and cell death. This conclusion was confirmed by the finding that enhancement of VK3-induced H2O2 generation by vitamin C (VC) could significantly promote both the histone hyperacetylation and cell death. Further studies suggested that histone hyperacetylation played an important role in VK3-induced cell death, since sodium butyrate, a histone deacetylase (HDAC) inhibitor, showed no effect on ROS generation, but obviously potentiated VK3-induced histone hyperacetylation and cell death. Collectively, these results demonstrate a novel mechanism for the anticancer activity of VK3, i.e., VK3 induced tumor cell death through H2O2 generation, which then further induced histone hyperacetylation.

  10. Sertoli cell death by apoptosis in the immature rat testis following x-irradiation

    International Nuclear Information System (INIS)

    Allan, D.J.; Gobe, G.C.; Harmon, B.V.

    1988-01-01

    The importance of the morphological study of cell death has recently been emphasized by the recognition that the ultrastructural features of dying cells allow categorization of the death as either apoptosis or necrosis. This classification enables inferences to be drawn about the mechanism and biological significance of the death occurring in a particular set of circumstances. In this study, Sertoli cell death induced in the immature testis of three and four day old rats by 5 Gy (500 rads) x-irradiation was described by light and transmission electron microscopy with the objective of categorizing the death as apoptosis or necrosis. The testes were examined 1, 2, 3, 4, 8, and 24 h after irradiation. Following irradiation, there was a wave of apoptosis of the Sertoli cells starting in three to four hours and reaching a peak between four and eight hours. At 24 hours, only 61% of the expected number of Sertoli cells remained. These findings are in accord with recent ultrastructural reports that ionizing radiation induces cell death by apoptosis in rapidly proliferating cell populations. New insights into the pathogenesis of radiation-induced cell death might thus be expected to stem from future elucidation of the general molecular events involved in triggering apoptosis

  11. FMSP-Nanoparticles Induced Cell Death on Human Breast Adenocarcinoma Cell Line (MCF-7 Cells: Morphometric Analysis

    Directory of Open Access Journals (Sweden)

    Firdos Alam Khan

    2018-05-01

    Full Text Available Currently, breast cancer treatment mostly revolves around radiation therapy and surgical interventions, but often these treatments do not provide satisfactory relief to the patients and cause unmanageable side-effects. Nanomaterials show promising results in treating cancer cells and have many advantages such as high biocompatibility, bioavailability and effective therapeutic capabilities. Interestingly, fluorescent magnetic nanoparticles have been used in many biological and diagnostic applications, but there is no report of use of fluorescent magnetic submicronic polymer nanoparticles (FMSP-nanoparticles in the treatment of human breast cancer cells. In the present study, we tested the effect of FMSP-nanoparticles on human breast cancer cells (MCF-7. We tested different concentrations (1.25, 12.5 and 50 µg/mL of FMSP-nanoparticles in MCF-7 cells and evaluated the nanoparticles response morphometrically. Our results revealed that FMSP-nanoparticles produced a concentration dependent effect on the cancer cells, a dose of 1.25 µg/mL produced no significant effect on the cancer cell morphology and cell death, whereas dosages of 12.5 and 50 µg/mL resulted in significant nuclear augmentation, disintegration, chromatic condensation followed by dose dependent cell death. Our results demonstrate that FMSP-nanoparticles induce cell death in MCF-7 cells and may be a potential anti-cancer agent for breast cancer treatment.

  12. Baicalein induces cell death in murine T cell lymphoma via inhibition of thioredoxin system.

    Science.gov (United States)

    Patwardhan, Raghavendra S; Pal, Debojyoti; Checker, Rahul; Sharma, Deepak; Sandur, Santosh K

    2017-10-01

    We have earlier demonstrated the radioprotective potential of baicalein using murine splenic lymphocytes. Here, we have studied the effect of baicalein on murine T cell lymphoma EL4 cells and investigated the underlying mechanism of action. We observed that baicalein induced a dose dependent cell death in EL4 cells in vitro and significantly reduced the frequency of cancer stem cells. Previously, we have reported that murine and human T cell lymphoma cells have increased oxidative stress tolerance capacity due to active thioredoxin system. Hence, we monitored the effect of baicalein on thioredoxin system in EL4 cells. Docking studies revealed that baicalein could bind to the active site of thioredoxin reductase. Baicalein treatment led to significant reduction in the activity of thioredoxin reductase and nuclear levels of thioredoxin-1 thereby increasing ASK1 levels and caspase-3 activity. Interestingly, CRISPR-Cas9 based knock-out of ASK1 or over-expression of thioredoxin-1 abolished anti-tumor effects of baicalein in EL4 cells. Further, baicalein administration significantly reduced intra-peritoneal tumor burden of EL4 cells in C57BL/6 mice. Thus, our study describes anti-tumor effects of baicalein in EL4 cells via inhibition of thioredoxin system. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Alkaloids from Juglans Mandshurica maxim induce distinctive cell death in hepatocellular carcinoma cells.

    Science.gov (United States)

    Lou, Li-Li; Cheng, Zhuo-Yang; Guo, Rui; Yao, Guo-Dong; Song, Shao-Jiang

    2017-12-15

    The aim of this work was to further investigate the anticancer potential of Juglans mandshurica Maxim, including the separation of active constituents and their anti-proliferative effects with underlying mechanism of action. Five alkaloids (1-5) were isolated from the bark of J. mandshurica. Among them, 1 showed the highest cytotoxic activities against Hep3B and HepG2 cells with an IC50 values of 61.80 and 56.24 μM, respectively. Therefore, the cellular mechanism involved 1 was subsequently studied. Our results showed that 1 markedly caused apoptosis and autophagy, but without cell cycle arrest in HepG2 cells. Interestingly, only autophagic cell death was induced in 1-treated Hep3B cells. It is concluded that the isolated alkaloids exerted a certain anti-hepatoma potential, and our results may provide a basis for the further investigation of the alkaloids extracted from J. mandshurica.

  14. TP508 accelerates fracture repair by promoting cell growth over cell death

    International Nuclear Information System (INIS)

    Li Xinmin; Wang Hali; Touma, Edward; Qi Yuchen; Rousseau, Emma; Quigg, Richard J.; Ryaby, James T.

    2007-01-01

    TP508 is a synthetic 23-amino acid peptide representing a receptor-binding domain of human thrombin. We have previously shown that a single injection of TP508 accelerates fracture healing in a rat femoral fracture model. To understand how TP508 acts at the protein level during fracture healing, we compared the translational profiles between saline-control and fractured femur at six time points after TP508 treatment using the second generation of BD Clontech TM Antibody Microarray. Here, we demonstrate that TP508 accelerates fracture healing by modulating expression levels of proteins primarily involved in the functional categories of cell cycle, cellular growth and proliferation, and cell death. The majority of those proteins are physically interrelated and functionally overlapped. The action of those proteins is highlighted by a central theme of promoting cell growth via balance of cell survival over cell death signals. This appears to occur through the stimulation of several bone healing pathways including cell cycle-G1/S checkpoint regulation, apoptosis, JAK/STAT, NF-κB, PDGF, PI3K/AKT, PTEN, and ERK/MAPK

  15. The bacterial cell cycle checkpoint protein Obg and its role in programmed cell death

    Directory of Open Access Journals (Sweden)

    Liselot Dewachter

    2016-03-01

    Full Text Available The phenomenon of programmed cell death (PCD, in which cells initiate their own demise, is not restricted to multicellular organisms. Unicellular organisms, both eukaryotes and prokaryotes, also possess pathways that mediate PCD. We recently identified a PCD mechanism in Escherichia coli that is triggered by a mutant isoform of the essential GTPase ObgE (Obg of E. coli. Importantly, the PCD pathway mediated by mutant Obg (Obg* differs fundamentally from other previously described bacterial PCD pathways and thus constitutes a new mode of PCD. ObgE was previously proposed to act as a cell cycle checkpoint protein able to halt cell division. The implication of ObgE in the regulation of PCD further increases the similarity between this protein and eukaryotic cell cycle regulators that are capable of doing both. Moreover, since Obg is conserved in eukaryotes, the elucidation of this cell death mechanism might contribute to the understanding of PCD in higher organisms. Additionally, if Obg*-mediated PCD is conserved among different bacterial species, it will be a prime target for the development of innovative antibacterials that artificially induce this pathway.

  16. Untangling the Roles of Anti-Apoptosis in Regulating Programmed Cell Death using Humanized Yeast Cells

    International Nuclear Information System (INIS)

    Clapp, Caitlin; Portt, Liam; Khoury, Chamel; Sheibani, Sara; Eid, Rawan; Greenwood, Matthew; Vali, Hojatollah; Mandato, Craig A.; Greenwood, Michael T.

    2012-01-01

    Genetically programmed cell death (PCD) mechanisms, including apoptosis, are important for the survival of metazoans since it allows, among things, the removal of damaged cells that interfere with normal function. Cell death due to PCD is observed in normal processes such as aging and in a number of pathophysiologies including hypoxia (common causes of heart attacks and strokes) and subsequent tissue reperfusion. Conversely, the loss of normal apoptotic responses is associated with the development of tumors. So far, limited success in preventing unwanted PCD has been reported with current therapeutic approaches despite the fact that inhibitors of key apoptotic inducers such as caspases have been developed. Alternative approaches have focused on mimicking anti-apoptotic processes observed in cells displaying increased resistance to apoptotic stimuli. Hormesis and pre-conditioning are commonly observed cellular strategies where sub-lethal levels of pro-apoptotic stimuli lead to increased resistance to higher or lethal levels of stress. Increased expression of anti-apoptotic sequences is a common mechanism mediating these protective effects. The relevance of the latter observation is exemplified by the observation that transgenic mice overexpressing anti-apoptotic genes show significant reductions in tissue damage following ischemia. Thus strategies aimed at increasing the levels of anti-apoptotic proteins, using gene therapy or cell penetrating recombinant proteins are being evaluated as novel therapeutics to decrease cell death following acute periods of cell death inducing stress. In spite of its functional and therapeutic importance, more is known regarding the processes involved in apoptosis than anti-apoptosis. The genetically tractable yeast Saccharomyces cerevisiae has emerged as an exceptional model to study multiple aspects of PCD including the mitochondrial mediated apoptosis observed in metazoans. To increase our knowledge of the process of anti

  17. Streptococcus sanguinis induces foam cell formation and cell death of macrophages in association with production of reactive oxygen species.

    Science.gov (United States)

    Okahashi, Nobuo; Okinaga, Toshinori; Sakurai, Atsuo; Terao, Yutaka; Nakata, Masanobu; Nakashima, Keisuke; Shintani, Seikou; Kawabata, Shigetada; Ooshima, Takashi; Nishihara, Tatsuji

    2011-10-01

    Streptococcus sanguinis, a normal inhabitant of the human oral cavity, is a common streptococcal species implicated in infective endocarditis. Herein, we investigated the effects of infection with S. sanguinis on foam cell formation and cell death of macrophages. Infection with S. sanguinis stimulated foam cell formation of THP-1, a human macrophage cell line. At a multiplicity of infection >100, S. sanguinis-induced cell death of the macrophages. Viable bacterial infection was required to trigger cell death because heat-inactivated S. sanguinis did not induce cell death. The production of cytokines interleukin-1β and tumor necrosis factor-α from macrophages was also stimulated during bacterial infection. Inhibition of the production of reactive oxygen species (ROS) resulted in reduced cell death, suggesting an association of ROS with cell death. Furthermore, S. sanguinis-induced cell death appeared to be independent of activation of inflammasomes, because cleavage of procaspase-1 was not evident in infected macrophages. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  18. Co-culture of human CD34+ cells with mesenchymal stem cells increases the survival of CD34+ cells against the 5-aza-deoxycytidine- or trichostatin A-induced cell death

    International Nuclear Information System (INIS)

    Koh, Sang Hyeok; Choi, Hyoung Soo; Park, Eun Sil; Kang, Hyoung Jin; Ahn, Hyo Seop; Shin, Hee Young

    2005-01-01

    It has been suggested that epigenetic regulation plays an important role in maintaining the stemness and lineage differentiation of hematopoietic stem cells (HSCs), 5-aza-deoxycytidine (aza-D) and Trichostatin A (TSA) being candidate additives for HSC ex vivo expansion. Although they have potent activity to maintain the stemness, they can also cause serious cell death. This study examined the effects of mesenchymal stem cells (MSCs) on the maintenance of CD34+ cells driven by aza-D and TSA in culture with the combined cytokines of thrombopoietin, flt-3 ligand, stem cell factor, interleukin-3, and interleukin-6. In cultures without MSCs, although aza-D and TSA retained the CD34 frequency 4 to 8 times more than in the cytokines alone, a large portion of cells underwent apoptotic cell death. Consequently, CD34+ cell expansion could not be achieved in any condition without MSCs. In cultures with MSCs, the total cell number was higher in aza-D or TSA than in any conditions in the cultures without MSCs. The CD34 frequency was also similar to the level in the cultures in aza-D or TSA without the MSCs. These results suggest that a co-culture of CD34+ cells with the MSCs might not simply deliver the proliferation signals but also stemness and survival signals, and overlap the action of epigenetic regulators

  19. The cell on the edge of life and death: Crosstalk between autophagy and apoptosis.

    Science.gov (United States)

    Kasprowska-Liśkiewicz, Daniela

    2017-09-21

    Recently, the crosstalk between autophagy and apoptosis has attracted broader attention. Basal autophagy serves to maintain cell homeostasis, while the upregulation of this process is an element of stress response that enables the cell to survive under adverse conditions. Autophagy may also determine the fate of the cell through its interactions with cell death pathways. The protein networks that control the initiation and the execution phase of these two processes are highly interconnected. Several scenarios for the crosstalk between autophagy and apoptosis exist. In most cases, the activation of autophagy represents an attempt of the cell to cope with stress, and protects the cell from apoptosis or delays its initiation. Generally, the simultaneous activation of pro-survival and pro-death pathways is prevented by the mutual inhibitory crosstalk between autophagy and apoptosis. But in some circumstances, autophagy or the proteins of the core autophagic machinery may promote cellular demise through excessive self-digestion (so-called "autophagic cell death") or by stimulating the activation of other cell death pathways. It is controversial whether cells actually die via autophagy, which is why the term "autophagic cell death" has been under intense debate lately. This review summarizes the recent findings on the multilevel crosstalk between autophagy and apoptosis in aspects of common regulators, mutual inhibition of these processes, the stimulation of apoptosis by autophagy or autophagic proteins and finally the role of autophagy as a death-execution mechanism.

  20. Guidelines for the use and interpretation of assays for monitoring cell death in higher eukaryotes.

    Science.gov (United States)

    Galluzzi, L; Aaronson, S A; Abrams, J; Alnemri, E S; Andrews, D W; Baehrecke, E H; Bazan, N G; Blagosklonny, M V; Blomgren, K; Borner, C; Bredesen, D E; Brenner, C; Castedo, M; Cidlowski, J A; Ciechanover, A; Cohen, G M; De Laurenzi, V; De Maria, R; Deshmukh, M; Dynlacht, B D; El-Deiry, W S; Flavell, R A; Fulda, S; Garrido, C; Golstein, P; Gougeon, M-L; Green, D R; Gronemeyer, H; Hajnóczky, G; Hardwick, J M; Hengartner, M O; Ichijo, H; Jäättelä, M; Kepp, O; Kimchi, A; Klionsky, D J; Knight, R A; Kornbluth, S; Kumar, S; Levine, B; Lipton, S A; Lugli, E; Madeo, F; Malomi, W; Marine, J-C W; Martin, S J; Medema, J P; Mehlen, P; Melino, G; Moll, U M; Morselli, E; Nagata, S; Nicholson, D W; Nicotera, P; Nuñez, G; Oren, M; Penninger, J; Pervaiz, S; Peter, M E; Piacentini, M; Prehn, J H M; Puthalakath, H; Rabinovich, G A; Rizzuto, R; Rodrigues, C M P; Rubinsztein, D C; Rudel, T; Scorrano, L; Simon, H-U; Steller, H; Tschopp, J; Tsujimoto, Y; Vandenabeele, P; Vitale, I; Vousden, K H; Youle, R J; Yuan, J; Zhivotovsky, B; Kroemer, G

    2009-08-01

    Cell death is essential for a plethora of physiological processes, and its deregulation characterizes numerous human diseases. Thus, the in-depth investigation of cell death and its mechanisms constitutes a formidable challenge for fundamental and applied biomedical research, and has tremendous implications for the development of novel therapeutic strategies. It is, therefore, of utmost importance to standardize the experimental procedures that identify dying and dead cells in cell cultures and/or in tissues, from model organisms and/or humans, in healthy and/or pathological scenarios. Thus far, dozens of methods have been proposed to quantify cell death-related parameters. However, no guidelines exist regarding their use and interpretation, and nobody has thoroughly annotated the experimental settings for which each of these techniques is most appropriate. Here, we provide a nonexhaustive comparison of methods to detect cell death with apoptotic or nonapoptotic morphologies, their advantages and pitfalls. These guidelines are intended for investigators who study cell death, as well as for reviewers who need to constructively critique scientific reports that deal with cellular demise. Given the difficulties in determining the exact number of cells that have passed the point-of-no-return of the signaling cascades leading to cell death, we emphasize the importance of performing multiple, methodologically unrelated assays to quantify dying and dead cells.

  1. Simultaneous activation of mitophagy and autophagy by staurosporine protects against dopaminergic neuronal cell death.

    Science.gov (United States)

    Ha, Ji-Young; Kim, Ji-Soo; Kim, Seo-Eun; Son, Jin H

    2014-02-21

    Abnormal autophagy is frequently observed during dopaminergic neurodegeneration in Parkinson's disease (PD). However, it is not yet firmly established whether active autophagy is beneficial or pathogenic with respect to dopaminergic cell loss. Staurosporine, a common inducer of apoptosis, is often used in mechanistic studies of dopaminergic cell death. Here we report that staurosporine activates both autophagy and mitophagy simultaneously during dopaminergic neuronal cell death, and evaluate the physiological significance of these processes during cell death. First, staurosporine treatment resulted in induction of autophagy in more than 75% of apoptotic cells. Pharmacological inhibition of autophagy by bafilomycin A1 decreased significantly cell viability. In addition, staurosporine treatment resulted in activation of the PINK1-Parkin mitophagy pathway, of which deficit underlies some familial cases of PD, in the dopaminergic neuronal cell line, SN4741. The genetic blockade of this pathway by PINK1 null mutation also dramatically increased staurosporine-induced cell death. Taken together, our data suggest that staurosporine induces both mitophagy and autophagy, and that these pathways exert a significant neuroprotective effect, rather than a contribution to autophagic cell death. This model system may therefore be useful for elucidating the mechanisms underlying crosstalk between autophagy, mitophagy, and cell death in dopaminergic neurons. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  2. Cannabinoid-induced cell death in endometrial cancer cells: involvement of TRPV1 receptors in apoptosis.

    Science.gov (United States)

    Fonseca, B M; Correia-da-Silva, G; Teixeira, N A

    2018-05-01

    Among a variety of phytocannabinoids, Δ 9 -tetrahydrocannabinol (THC) and cannabidiol (CBD) are the most promising therapeutic compounds. Besides the well-known palliative effects in cancer patients, cannabinoids have been shown to inhibit in vitro growth of tumor cells. Likewise, the major endocannabinoids (eCBs), anandamide (AEA) and 2-arachidonoylglycerol (2-AG), induce tumor cell death. The purpose of the present study was to characterize cannabinoid elements and evaluate the effect of cannabinoids in endometrial cancer cell viability. The presence of cannabinoid receptors, transient receptor potential vanilloid 1 (TRPV1), and endocannabinoid-metabolizing enzymes were determined by qRT-PCR and Western blot. We also examined the effects and the underlying mechanisms induced by eCBs and phytocannabinoids in endometrial cancer cell viability. Besides TRPV1, both EC cell lines express all the constituents of the endocannabinoid system. We observed that at concentrations higher than 5 μM, eCBs and CBD induced a significant reduction in cell viability in both Ishikawa and Hec50co cells, whereas THC did not cause any effect. In Ishikawa cells, contrary to Hec50co, treatment with AEA and CBD resulted in an increase in the levels of activated caspase -3/-7, in cleaved PARP, and in reactive oxygen species generation, confirming that the reduction in cell viability observed in the MTT assay was caused by the activation of the apoptotic pathway. Finally, these effects were dependent on TRPV1 activation and intracellular calcium levels. These data indicate that cannabinoids modulate endometrial cancer cell death. Selective targeting of TPRV1 by AEA, CBD, or other stable analogues may be an attractive research area for the treatment of estrogen-dependent endometrial carcinoma. Our data further support the evaluation of CBD and CBD-rich extracts for the potential treatment of endometrial cancer, particularly, that has become non-responsive to common therapies.

  3. Interplay between autophagy and programmed cell death in mammalian neural stem cells

    Directory of Open Access Journals (Sweden)

    Kyung Min Chung

    2013-08-01

    Full Text Available Mammalian neural stem cells (NSCs are of particular interestbecause of their role in brain development and function. Recentfindings suggest the intimate involvement of programmed celldeath (PCD in the turnover of NSCs. However, the underlyingmechanisms of PCD are largely unknown. Although apoptosis isthe best-defined form of PCD, accumulating evidence hasrevealed a wide spectrum of PCD encompassing apoptosis,autophagic cell death (ACD and necrosis. This mini-reviewaims to illustrate a unique regulation of PCD in NSCs. Theresults of our recent studies on autophagic death of adulthippocampal neural stem (HCN cells are also discussed. HCNcell death following insulin withdrawal clearly provides areliable model that can be used to analyze the molecularmechanisms of ACD in the larger context of PCD. Moreresearch efforts are needed to increase our understanding of themolecular basis of NSC turnover under degenerating conditions,such as aging, stress and neurological diseases. Efforts aimed atprotecting and harnessing endogenous NSCs will offer novelopportunities for the development of new therapeutic strategiesfor neuropathologies. [BMB Reports 2013; 46(8: 383-390

  4. Induction of cytosine arabinoside-resistant human myeloid leukemia cell death through autophagy regulation by hydroxychloroquine.

    Science.gov (United States)

    Kim, Yundeok; Eom, Ju-In; Jeung, Hoi-Kyung; Jang, Ji Eun; Kim, Jin Seok; Cheong, June-Won; Kim, Young Sam; Min, Yoo Hong

    2015-07-01

    We investigated the effects of the autophagy inhibitor hydroxychloroquine (HCQ) on cell death of cytosine arabinoside (Ara-C)-resistant human acute myeloid leukemia (AML) cells. Ara-C-sensitive (U937, AML-2) and Ara-C-resistant (U937/AR, AML-2/AR) human AML cell lines were used to evaluate HCQ-regulated cytotoxicity, autophagy, and apoptosis as well as effects on cell death-related signaling pathways. We found that HCQ-induced dose- and time-dependent cell death in Ara-C-resistant cells compared to Ara-C-sensitive cell lines. The extent of cell death and features of HCQ-induced autophagic markers including increase in microtubule-associated protein light chain 3 (LC3) I conversion to LC3-II, beclin-1, ATG5, as well as green fluorescent protein-LC3 positive puncta and autophagosome were remarkably greater in U937/AR cells. Also, p62/SQSTM1 was increased in response to HCQ. p62/SQSTM1 protein interacts with both LC3-II and ubiquitin protein and is degraded in autophagosomes. Therefore, a reduction of p62/SQSTM1 indicates increased autophagic degradation, whereas an increase of p62/SQSTM1 by HCQ indicates inhibited autophagic degradation. Knock down of p62/SQSTM1 using siRNA were prevented the HCQ-induced LC3-II protein level as well as significantly reduced the HCQ-induced cell death in U937/AR cells. Also, apoptotic cell death and caspase activation in U937/AR cells were increased by HCQ, provided evidence that HCQ-induced autophagy blockade. Taken together, our data show that HCQ-induced apoptotic cell death in Ara-C-resistant AML cells through autophagy regulation. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  5. Cytoplasmic PELP1 and ERRgamma protect human mammary epithelial cells from Tam-induced cell death.

    Science.gov (United States)

    Girard, Brian J; Regan Anderson, Tarah M; Welch, Siya Lem; Nicely, Julie; Seewaldt, Victoria L; Ostrander, Julie H

    2015-01-01

    Tamoxifen (Tam) is the only FDA-approved chemoprevention agent for pre-menopausal women at high risk for developing breast cancer. While Tam reduces a woman's risk of developing estrogen receptor positive (ER+) breast cancer, the molecular mechanisms associated with risk reduction are poorly understood. Prior studies have shown that cytoplasmic proline, glutamic acid and leucine rich protein 1 (PELP1) promotes Tam resistance in breast cancer cell lines. Herein, we tested for PELP1 localization in breast epithelial cells from women at high risk for developing breast cancer and found that PELP1 was localized to the cytoplasm in 36% of samples. In vitro, immortalized HMECs expressing a nuclear localization signal (NLS) mutant of PELP1 (PELP1-cyto) were resistant to Tam-induced death. Furthermore, PELP1-cyto signaling through estrogen-related receptor gamma (ERRγ) promoted cell survival in the presence of Tam. Overexpression of ERRγ in immortalized HMECs protected cells from Tam-induced death, while knockdown of ERRγ sensitized PELP1-cyto expressing HMECs to Tam. Moreover, Tam-induced HMEC cell death was independent of apoptosis and involved accumulation of the autophagy marker LC3-II. Expression of PELP1-cyto and ERRγ reduced Tam-induced LC3-II accumulation, and knockdown of ERRγ increased LC3-II levels in response to Tam. Additionally, PELP1-cyto expression led to the upregulation of MMP-3 and MAOB, known PELP1 and ERRγ target genes, respectively. Our data indicate that cytoplasmic PELP1 induces signaling pathways that converge on ERRγ to promote cell survival in the presence of Tam. These data suggest that PELP1 localization and/or ERRγ activation could be developed as tissue biomarkers for Tam responsiveness.

  6. Effect of Gamma Knife Radiosurgery and Programmed Cell Death 1 Receptor Antagonists on Metastatic Melanoma

    Science.gov (United States)

    Hubbard, Molly; Nordmann, Tyler; Sperduto, Paul W; Clark, H. Brent; Hunt, Matthew A

    2017-01-01

    Learning objectives To evaluate radiation-induced changes in patients with brain metastasis secondary to malignant melanoma who received treatment with Gamma Knife radiosurgery (GKRS) and programmed cell death 1 (PD-1) receptor antagonists. Introduction  Stereotactic radiosurgery and chemotherapeutics are used together for treatment of metastatic melanoma and have been linked to delayed radiation-induced vasculitic leukoencephalopathy (DRIVL). There have been reports of more intense interactions with new immunotherapeutics targeting PD-1 receptors, but their interactions have not been well described and may result in an accelerated response to GKRS. Here we present data on subjects treated with this combination from a single institution. Methods Records from patients who underwent treatment for metastatic melanoma to the brain with GKRS from 2011 to 2016 were reviewed. Demographics, date of brain metastasis diagnosis, cause of death when applicable, immunotherapeutics, and imaging findings were recorded. The timing of radiation therapy and medications were also documented.  Results A total of 79 subjects were treated with GKRS, and 66 underwent treatment with both GKRS and immunotherapy. Regarding the 30 patients treated with anti-PD-1 immunotherapy, 21 patients received pembrolizumab, seven patients received nivolumab, and two patients received pembrolizumab and nivolumab. Serial imaging was available for interpretation in 25 patients, with 13 subjects who received GKRS and anti-PD-1 immunotherapy less than six weeks of each other. While four subjects had indeterminate/mixed findings on subsequent magnetic resonance imaging (MRI), nine subjects were noted to have progression. Two of these patients showed progression but subsequent imaging revealed a decrease in progression or improvement on MRI to previously targeted lesions by GKRS. None of the 13 subjects had surgery following their combined therapies. Conclusions This data suggests that there is need for

  7. A theoretical model of naturally occurring cell death in the nervous system

    OpenAIRE

    Galli, Resta; Resta, Giovanni

    1991-01-01

    Throughout the animal kingdom, the formation of the nervous system involves the elimination of many cells, soon after their generation. This phenomenon, known as naturally occurring cell death, has precise time schedules, is observed in the vast majority of nervous structures and causes the 1oss of 15 - 85% of the neurones generated initially. Elimination of erroneous projections, as well as proper size matching between connecting structures can be achieved through cell death. However if elim...

  8. Obligatory participation of macrophages in an angiopoietin 2-mediated cell death switch

    OpenAIRE

    Rao, Sujata; Lobov, Ivan B.; Vallance, Jefferson E.; Tsujikawa, Kaoru; Shiojima, Ichiro; Akunuru, Shailaja; Walsh, Kenneth; Benjamin, Laura E.; Lang, Richard A.

    2007-01-01

    Macrophages have a critical function in the recognition and engulfment of dead cells. In some settings, macrophages also actively signal programmed cell death. Here we show that during developmentally scheduled vascular regression, resident macrophages are an obligatory participant in a signaling switch that favors death over survival. This switch occurs when the signaling ligand angiopoietin 2 has the dual effect of suppressing survival signaling in vascular endothelial cells (VECs) and stim...

  9. Drug-Induced Liver Injury: Cascade of Events Leading to Cell Death, Apoptosis or Necrosis

    Directory of Open Access Journals (Sweden)

    Andrea Iorga

    2017-05-01

    Full Text Available Drug-induced liver injury (DILI can broadly be divided into predictable and dose dependent such as acetaminophen (APAP and unpredictable or idiosyncratic DILI (IDILI. Liver injury from drug hepatotoxicity (whether idiosyncratic or predictable results in hepatocyte cell death and inflammation. The cascade of events leading to DILI and the cell death subroutine (apoptosis or necrosis of the cell depend largely on the culprit drug. Direct toxins to hepatocytes likely induce oxidative organelle stress (such as endoplasmic reticulum (ER and mitochondrial stress leading to necrosis or apoptosis, while cell death in idiosyncratic DILI (IDILI is usually the result of engagement of the innate and adaptive immune system (likely apoptotic, involving death receptors (DR. Here, we review the hepatocyte cell death pathways both in direct hepatotoxicity such as in APAP DILI as well as in IDILI. We examine the known signaling pathways in APAP toxicity, a model of necrotic liver cell death. We also explore what is known about the genetic basis of IDILI and the molecular pathways leading to immune activation and how these events can trigger hepatotoxicity and cell death.

  10. Degenerative changes and cell death in long-living homo- and heterotopic transplants from embryonic germ layers of rat neocortex.

    Science.gov (United States)

    Petrova, E S; Otellin, V A

    2003-09-01

    Morphological study of allotransplants of rat embryonic neocortex 14-18 months after transplantation into the neocortex, lateral cerebral ventricle, and sciatic nerve of adult animals revealed death of nerve and glial cells in the delayed postoperation period independently on the site of transplantation. After heterotopic transplantation the count of degenerated neurons was 2 times higher that after homotopic transplantation. In heterotopic transplants a considerable number of grafted neurons underwent reversible and irreversible degenerative changes accompanied by their premature aging. Neuronal death is probably determined by insufficiency of trophic influence from afferent structures and target tissues. We hypothesized that antiapoptotic preparations can be used for prevention of transplanted cell death. It was also found that degeneration of neurons was associated with impaired vascularization of transplants and pronounced immune reaction of the recipient in late posttransplantation period. Transplantation of embryonic brain structures can serve as a model system in studies concerning involutive and pathological processes in the central nervous system and in the search for factors improving survival of neurons.

  11. The natural product peiminine represses colorectal carcinoma tumor growth by inducing autophagic cell death

    International Nuclear Information System (INIS)

    Lyu, Qing; Tou, Fangfang; Su, Hong; Wu, Xiaoyong; Chen, Xinyi; Zheng, Zhi

    2015-01-01

    Autophagy is evolutionarily conservative in eukaryotic cells that engulf cellular long-lived proteins and organelles, and it degrades the contents through fusion with lysosomes, via which the cell acquires recycled building blocks for the synthesis of new molecules. In this study, we revealed that peiminine induces cell death and enhances autophagic flux in colorectal carcinoma HCT-116 cells. We determined that peiminine enhances the autophagic flux by repressing the phosphorylation of mTOR through inhibiting upstream signals. Knocking down ATG5 greatly reduced the peiminine-induced cell death in wild-type HCT-116 cells, while treating Bax/Bak-deficient cells with peiminine resulted in significant cell death. In summary, our discoveries demonstrated that peiminine represses colorectal carcinoma cell proliferation and cell growth by inducing autophagic cell death. - Highlights: • Peiminine induces autophagy and upregulates autophagic flux. • Peiminine represses colorectal carcinoma tumor growth. • Peiminine induces autophagic cell death. • Peiminine represses mTOR phosphorylation by influencing PI3K/Akt and AMPK pathway

  12. The natural product peiminine represses colorectal carcinoma tumor growth by inducing autophagic cell death

    Energy Technology Data Exchange (ETDEWEB)

    Lyu, Qing [School of Life Sciences, Tsinghua University, Beijing, 100084 (China); Key Lab in Healthy Science and Technology, Division of Life Science, Graduate School at Shenzhen, Tsinghua University, Shenzhen, 518055 (China); Tou, Fangfang [Jiangxi Provincial Key Lab of Oncology Translation Medicine, Jiangxi Cancer Hospital, Nanchang, 330029 (China); Su, Hong; Wu, Xiaoyong [First Affiliated Hospital, Guiyang College of Traditional Chinese Medicine, Guiyang, 550002 (China); Chen, Xinyi [Department of Hematology and Oncology, Beijing University of Chinese Medicine, Beijing, 100029 (China); Zheng, Zhi, E-mail: zheng_sheva@hotmail.com [Jiangxi Provincial Key Lab of Oncology Translation Medicine, Jiangxi Cancer Hospital, Nanchang, 330029 (China)

    2015-06-19

    Autophagy is evolutionarily conservative in eukaryotic cells that engulf cellular long-lived proteins and organelles, and it degrades the contents through fusion with lysosomes, via which the cell acquires recycled building blocks for the synthesis of new molecules. In this study, we revealed that peiminine induces cell death and enhances autophagic flux in colorectal carcinoma HCT-116 cells. We determined that peiminine enhances the autophagic flux by repressing the phosphorylation of mTOR through inhibiting upstream signals. Knocking down ATG5 greatly reduced the peiminine-induced cell death in wild-type HCT-116 cells, while treating Bax/Bak-deficient cells with peiminine resulted in significant cell death. In summary, our discoveries demonstrated that peiminine represses colorectal carcinoma cell proliferation and cell growth by inducing autophagic cell death. - Highlights: • Peiminine induces autophagy and upregulates autophagic flux. • Peiminine represses colorectal carcinoma tumor growth. • Peiminine induces autophagic cell death. • Peiminine represses mTOR phosphorylation by influencing PI3K/Akt and AMPK pathway.

  13. Mitochondrial calcium uniporter silencing potentiates caspase-independent cell death in MDA-MB-231 breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Curry, Merril C.; Peters, Amelia A. [School of Pharmacy, The University of Queensland, Brisbane, Queensland 4072 (Australia); Kenny, Paraic A. [Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, New York 10461 (United States); Roberts-Thomson, Sarah J. [School of Pharmacy, The University of Queensland, Brisbane, Queensland 4072 (Australia); Monteith, Gregory R., E-mail: gregm@uq.edu.au [School of Pharmacy, The University of Queensland, Brisbane, Queensland 4072 (Australia)

    2013-05-10

    Highlights: •Some clinical breast cancers are associated with MCU overexpression. •MCU silencing did not alter cell death initiated with the Bcl-2 inhibitor ABT-263. •MCU silencing potentiated caspase-independent cell death initiated by ionomycin. •MCU silencing promoted ionomycin-mediated cell death without changes in bulk Ca{sup 2+}. -- Abstract: The mitochondrial calcium uniporter (MCU) transports free ionic Ca{sup 2+} into the mitochondrial matrix. We assessed MCU expression in clinical breast cancer samples using microarray analysis and the consequences of MCU silencing in a breast cancer cell line. Our results indicate that estrogen receptor negative and basal-like breast cancers are characterized by elevated levels of MCU. Silencing of MCU expression in the basal-like MDA-MB-231 breast cancer cell line produced no change in proliferation or cell viability. However, distinct consequences of MCU silencing were seen on cell death pathways. Caspase-dependent cell death initiated by the Bcl-2 inhibitor ABT-263 was not altered by MCU silencing; whereas caspase-independent cell death induced by the calcium ionophore ionomycin was potentiated by MCU silencing. Measurement of cytosolic Ca{sup 2+} levels showed that the promotion of ionomycin-induced cell death by MCU silencing occurs independently of changes in bulk cytosolic Ca{sup 2+} levels. This study demonstrates that MCU overexpression is a feature of some breast cancers and that MCU overexpression may offer a survival advantage against some cell death pathways. MCU inhibitors may be a strategy to increase the effectiveness of therapies that act through the induction of caspase-independent cell death pathways in estrogen receptor negative and basal-like breast cancers.

  14. Hop/STI1 modulates retinal proliferation and cell death independent of PrPC

    International Nuclear Information System (INIS)

    Arruda-Carvalho, Maithe; Njaine, Brian; Silveira, Mariana S.; Linden, Rafael; Chiarini, Luciana B.

    2007-01-01

    Hop/STI1 is a co-chaperone adaptor protein for Hsp70/Hsp90 complexes. Hop/STI1 is found extracellularly and modulates cell death and differentiation through interaction with the prion protein (PrP C ). Here, we investigated the expression of hop/STI1 and its role upon cell proliferation and cell death in the developing retina. Hop/STI1 is more expressed in developing rat retina than in the mature tissue. Hop/STI1 blocks retinal cell death in the neuroblastic layer (NBL) in a PrP C dependent manner, but failed to protect ganglion cells against axotomy-induced cell death. An antibody raised against hop/STI1 (α-STI1) blocked both ganglion cell and NBL cell death independent of PrP C . cAMP/PKA, ERK, PI3K and PKC signaling pathways were not involved in these effects. Hop/STI1 treatment reduced proliferation, while α-STI1 increased proliferation in the developing retina, both independent of PrP C . We conclude that hop/STI1 can modulate both proliferation and cell death in the developing retina independent of PrP C

  15. Active ras triggers death in glioblastoma cells through hyperstimulation of macropinocytosis.

    Science.gov (United States)

    Overmeyer, Jean H; Kaul, Aparna; Johnson, Erin E; Maltese, William A

    2008-06-01

    Expression of activated Ras in glioblastoma cells induces accumulation of large phase-lucent cytoplasmic vacuoles, followed by cell death. This was previously described as autophagic cell death. However, unlike autophagosomes, the Ras-induced vacuoles are not bounded by a double membrane and do not sequester organelles or cytoplasm. Moreover, they are not acidic and do not contain the autophagosomal membrane protein LC3-II. Here we show that the vacuoles are enlarged macropinosomes. They rapidly incorporate extracellular fluid-phase tracers but do not sequester transferrin or the endosomal protein EEA1. Ultimately, the cells expressing activated Ras detach from the substratum and rupture, coincident with the displacement of cytoplasm with huge macropinosome-derived vacuoles. These changes are accompanied by caspase activation, but the broad-spectrum caspase inhibitor carbobenzoxy-Val-Ala-Asp-fluoromethylketone does not prevent cell death. Moreover, the majority of degenerating cells do not exhibit chromatin condensation typical of apoptosis. These observations provide evidence for a necrosis-like form of cell death initiated by dysregulation of macropinocytosis, which we have dubbed "methuosis." An activated form of the Rac1 GTPase induces a similar form of cell death, suggesting that Ras acts through Rac-dependent signaling pathways to hyperstimulate macropinocytosis in glioblastoma. Further study of these signaling pathways may lead to the identification of other chemical and physiologic triggers for this unusual form of cell death.

  16. Targeting Cellular Calcium Homeostasis to Prevent Cytokine-Mediated Beta Cell Death.

    Science.gov (United States)

    Clark, Amy L; Kanekura, Kohsuke; Lavagnino, Zeno; Spears, Larry D; Abreu, Damien; Mahadevan, Jana; Yagi, Takuya; Semenkovich, Clay F; Piston, David W; Urano, Fumihiko

    2017-07-17

    Pro-inflammatory cytokines are important mediators of islet inflammation, leading to beta cell death in type 1 diabetes. Although alterations in both endoplasmic reticulum (ER) and cytosolic free calcium levels are known to play a role in cytokine-mediated beta cell death, there are currently no treatments targeting cellular calcium homeostasis to combat type 1 diabetes. Here we show that modulation of cellular calcium homeostasis can mitigate cytokine- and ER stress-mediated beta cell death. The calcium modulating compounds, dantrolene and sitagliptin, both prevent cytokine and ER stress-induced activation of the pro-apoptotic calcium-dependent enzyme, calpain, and partly suppress beta cell death in INS1E cells and human primary islets. These agents are also able to restore cytokine-mediated suppression of functional ER calcium release. In addition, sitagliptin preserves function of the ER calcium pump, sarco-endoplasmic reticulum Ca 2+ -ATPase (SERCA), and decreases levels of the pro-apoptotic protein thioredoxin-interacting protein (TXNIP). Supporting the role of TXNIP in cytokine-mediated cell death, knock down of TXNIP in INS1-E cells prevents cytokine-mediated beta cell death. Our findings demonstrate that modulation of dynamic cellular calcium homeostasis and TXNIP suppression present viable pharmacologic targets to prevent cytokine-mediated beta cell loss in diabetes.

  17. X-ray-induced cell death by apoptosis in the immature rat cerebellum

    International Nuclear Information System (INIS)

    Harmon, B.V.; Allan, D.J.

    1988-01-01

    The cells of the external granular layer (EGL) of the developing cerebellum are known to be particularly sensitive to radiation. In the past, changes induced in this layer by irradiation have been referred to by non-specific terms such as pyknotic cells and the mode of cell death has been assumed to be necrosis. However, in published light micrographs of these dying cells, the appearance is suggestive of apoptosis, a distinctive mode of cell death which occurs spontaneously in normal adult and embryonic tissues and can also be triggered by certain pathological stimuli. This light and transmission electron microscopic study of control and irradiated (7 h post-irradiation) rat cerebellum from 18 day fetuses and 5 day-old neonates showed that the cell death was effected by apoptosis. The apoptosis was markedly enhanced by x-irradiation and quantification of the cell death in the EGL of 5 day-old rats exposed to 4, 8, 25, 100, and 400 cGy x-irradiation demonstrated that there was a positive dose response relationship. The extent of cell death by apoptosis which was 0.2% in control, ranged from 0.8% after 4 cGy to 62.3% after 400 cGy x-irradiation. The recognition that cell death by apoptosis can be a major component of x-irradiation damage has important implications for radiobiological studies

  18. The role of 12/15-lipoxygenases in ROS-mediated neuronal cell death

    OpenAIRE

    Tobaben, Svenja

    2011-01-01

    Oxidative stress has been established as a key trigger of neuronal dysfunction and death in age-related neurodegenerative diseases and in delayed neuronal death after acute brain injury by ischemic stroke or brain trauma. Despite increasing knowledge on the toxicity of reactive oxygen species (ROS) and oxidized reaction products that may further accelerate neuronal cell death, the major sources of ROS formation and the mechanisms ...

  19. The Phosphodiesterase 4 Inhibitor Roflumilast Protects against Cigarette Smoke Extract-Induced Mitophagy-Dependent Cell Death in Epithelial Cells.

    Science.gov (United States)

    Kyung, Sun Young; Kim, Yu Jin; Son, Eun Suk; Jeong, Sung Hwan; Park, Jeong Woong

    2018-04-01

    Recent studies show that mitophagy, the autophagy-dependent turnover of mitochondria, mediates pulmonary epithelial cell death in response to cigarette smoke extract (CSE) exposure and contributes to the development of emphysema in vivo during chronic cigarette smoke (CS) exposure, although the underlying mechanisms remain unclear. In this study, we investigated the role of mitophagy in the regulation of CSE-exposed lung bronchial epithelial cell (Beas-2B) death. We also investigated the role of a phosphodiesterase 4 inhibitor, roflumilast, in CSE-induced mitophagy-dependent cell death. Our results demonstrated that CSE induces mitophagy in Beas-2B cells through mitochondrial dysfunction and increased the expression levels of the mitophagy regulator protein, PTEN-induced putative kinase-1 (PINK1), and the mitochondrial fission protein, dynamin-1-like protein (DRP1). CSE-induced epithelial cell death was significantly increased in Beas-2B cells exposed to CSE but was decreased by small interfering RNA-dependent knockdown of DRP1. Treatment with roflumilast in Beas-2B cells inhibited CSE-induced mitochondrial dysfunction and mitophagy by inhibiting the expression of phospho-DRP1 and -PINK1. Roflumilast protected against cell death and increased cell viability, as determined by the lactate dehydrogenase release test and the MTT assay, respectively, in Beas-2B cells exposed to CSE. These findings suggest that roflumilast plays a protective role in CS-induced mitophagy-dependent cell death. Copyright©2018. The Korean Academy of Tuberculosis and Respiratory Diseases.

  20. Analysis of epothilone B-induced cell death in normal ovarian cells.

    Science.gov (United States)

    Rogalska, Aneta; Gajek, Arkadiusz; Marczak, Agnieszka

    2013-12-01

    We have investigated the mode of cell death induced by a new microtubule-stabilizing agent, epothilone B (EpoB, patupilone), and a clinically used medicine, paclitaxel (PTX), in normal ovarian cells. Using fluorescence microscopy, polyacrylamide gel electrophoresis preceding Western blot analysis, as well as spectrofluorimetric and colorimetric detection, we demonstrate that, compared to EpoB, PTX induced high time-dependent morphological and biochemical changes typical of apoptosis. Induction of apoptosis followed an early increase in p53 levels. Apoptosis reached its maximum at 24-48 h. At the same time, there was a significant increase in caspase-9 and -3 activity and PARP fragmentation, which suggests that an intrinsic path was involved. Apoptosis in MM14 cells was increased more by PTX than EpoB, and also induced more necrosis responsible for inflammation (1.4-fold) than EpoB. © 2013 International Federation for Cell Biology.

  1. NAD+ depletion or PAR polymer formation: which plays the role of executioner in ischaemic cell death?

    Science.gov (United States)

    Siegel, C; McCullough, L D

    2011-09-01

    Multiple cell death pathways are activated in cerebral ischaemia. Much of the initial injury, especially in the core of the infarct where cerebral blood flow is severely reduced, is necrotic and secondary to severe energy failure. However, there is considerable evidence that delayed cell death continues for several days, primarily in the penumbral region. As reperfusion therapies grow in number and effectiveness, restoration of blood flow early after injury may lead to a shift towards apoptosis. It is important to elucidate what are the key mediators of apoptotic cell death after stroke, as inhibition of apoptosis may have therapeutic implications. There are two well described pathways that lead to apoptotic cell death; the caspase pathway and the more recently described caspase-independent pathway triggered by poly-ADP-ribose polymers (PARP) activation. Caspase-induced cell death is initiated by release of mitochondrial cytochrome c, formation of the cytosolic apoptosome, and activation of endonucleases leading to a multitude of small randomly cleaved DNA fragments. In contrast caspase-independent cell death is secondary to activation of apoptosis inducing factor (AIF). Mitochondrial AIF translocates to the nucleus, where it induces peripheral chromatin condensation, as well as characteristic high-molecular-weight (50 kbp) DNA fragmentation. Although caspase-independent cell death has been recognized for some time and is known to contribute to ischaemic injury, the upstream triggering events leading to activation of this pathway remain unclear. The two major theories are that ischaemia leads to nicotinamide adenine dinucleotide (NAD+) depletion and subsequent energy failure, or alternatively that cell death is directly triggered by a pro-apoptotic factor produced by activation of the DNA repair enzyme PARP. PARP activation is robust in the ischaemic brain producing variable lengths of poly-ADP-ribose (PAR) polymers as byproducts of PARP activation. PAR polymers

  2. Paraptosis cell death induction by the thiamine analog benfotiamine in leukemia cells.

    Directory of Open Access Journals (Sweden)

    Naomi Sugimori

    Full Text Available Benfotiamine is a synthetic thiamine analogue that stimulates transketolase, a cellular enzyme essential for glucose metabolism. Currently, benfotiamine is used to treat diabetic neuropathy. We recently reported that oral benfotiamine induced a temporary but remarkable recovery from acute myeloid leukemia in an elderly patient who was ineligible for standard chemotherapy due to dementia and renal failure. In the present study we present evidences that benfotiamine possess antitumor activity against leukemia cells. In a panel of nine myeloid leukemia cell lines benfotiamine impaired the viability of HL-60, NB4, K562 and KG1 cells and also inhibited the growing of primary leukemic blasts. The antitumor activity of benfotiamine is not mediated by apoptosis, necrosis or autophagy, but rather occurs though paraptosis cell death induction. Mechanistic studies revealed that benfotiamine inhibited the activity of constitutively active ERK1/2 and concomitantly increased the phosphorylation of JNK1/2 kinase in leukemic cells. In addition, benfotiamine induced the down regulation of the cell cycle regulator CDK3 which resulted in G1 cell cycle arrest in the sensitive leukemic cells. Moreover, combination index studies showed that benfotiamine enhanced the antiproliferative activities of cytarabine against leukemia cells. These findings suggest that benfotiamine has antitumor therapeutic potential.

  3. Paraptosis cell death induction by the thiamine analog benfotiamine in leukemia cells.

    Science.gov (United States)

    Sugimori, Naomi; Espinoza, J Luis; Trung, Ly Quoc; Takami, Akiyoshi; Kondo, Yukio; An, Dao Thi; Sasaki, Motoko; Wakayama, Tomohiko; Nakao, Shinji

    2015-01-01

    Benfotiamine is a synthetic thiamine analogue that stimulates transketolase, a cellular enzyme essential for glucose metabolism. Currently, benfotiamine is used to treat diabetic neuropathy. We recently reported that oral benfotiamine induced a temporary but remarkable recovery from acute myeloid leukemia in an elderly patient who was ineligible for standard chemotherapy due to dementia and renal failure. In the present study we present evidences that benfotiamine possess antitumor activity against leukemia cells. In a panel of nine myeloid leukemia cell lines benfotiamine impaired the viability of HL-60, NB4, K562 and KG1 cells and also inhibited the growing of primary leukemic blasts. The antitumor activity of benfotiamine is not mediated by apoptosis, necrosis or autophagy, but rather occurs though paraptosis cell death induction. Mechanistic studies revealed that benfotiamine inhibited the activity of constitutively active ERK1/2 and concomitantly increased the phosphorylation of JNK1/2 kinase in leukemic cells. In addition, benfotiamine induced the down regulation of the cell cycle regulator CDK3 which resulted in G1 cell cycle arrest in the sensitive leukemic cells. Moreover, combination index studies showed that benfotiamine enhanced the antiproliferative activities of cytarabine against leukemia cells. These findings suggest that benfotiamine has antitumor therapeutic potential.

  4. The extrinsic cell death pathway and the élan mortel.

    Science.gov (United States)

    Wallach, D; Kang, T-B; Kovalenko, A

    2008-10-01

    Early in the exploration of the chemical nature of life, it was widely believed that the molecules of living organisms, by their very nature, differ from those of inorganic material molecules and possess a vital force ('élan vital'). Similarly, early scientific thinking on the subject of cell death and its induction by cytotoxic cells of the immune system was pervaded by a sense that the molecules mediating these functions possess intrinsic deadly activity and are dedicated exclusively to death-related tasks. This impression was also reflected in the initial notions of the mode of action of intracellular proteins that signal for death. It is now gradually becoming clear, however, that proteins participating in death induction also have functions unrelated to death. Nevertheless, as exemplified by studies of the function of caspase-8 (an enzyme that signals both for activation of the extrinsic cell-death pathway and for non-death-related effects), analysis of the mechanistic basis for such heterogeneity might allow identification of distinct structural determinants in the proteins participating in death induction that do bear death specificity.

  5. Apoptosis and tumor cell death in response to HAMLET (human alpha-lactalbumin made lethal to tumor cells).

    Science.gov (United States)

    Hallgren, Oskar; Aits, Sonja; Brest, Patrick; Gustafsson, Lotta; Mossberg, Ann-Kristin; Wullt, Björn; Svanborg, Catharina

    2008-01-01

    HAMLET (human alpha-lactalbumin made lethal to tumor cells) is a molecular complex derived from human milk that kills tumor cells by a process resembling programmed cell death. The complex consists of partially unfolded alpha-lactalbumin and oleic acid, and both the protein and the fatty acid are required for cell death. HAMLET has broad antitumor activity in vitro, and its therapeutic effect has been confirmed in vivo in a human glioblastoma rat xenograft model, in patients with skin papillomas and in patients with bladder cancer. The mechanisms of tumor cell death remain unclear, however. Immediately after the encounter with tumor cells, HAMLET invades the cells and causes mitochondrial membrane depolarization, cytochrome c release, phosphatidyl serine exposure, and a low caspase response. A fraction of the cells undergoes morphological changes characteristic of apoptosis, but caspase inhibition does not rescue the cells and Bcl-2 overexpression or altered p53 status does not influence the sensitivity of tumor cells to HAMLET. HAMLET also creates a state of unfolded protein overload and activates 20S proteasomes, which contributes to cell death. In parallel, HAMLET translocates to tumor cell nuclei, where high-affinity interactions with histones cause chromatin disruption, loss of transcription, and nuclear condensation. The dying cells also show morphological changes compatible with macroautophagy, and recent studies indicate that macroautophagy is involved in the cell death response to HAMLET. The results suggest that HAMLET, like a hydra with many heads, may interact with several crucial cellular organelles, thereby activating several forms of cell death, in parallel. This complexity might underlie the rapid death response of tumor cells and the broad antitumor activity of HAMLET.

  6. Transient Receptor Potential Vanilloid 1 Expression Mediates Capsaicin-Induced Cell Death

    Directory of Open Access Journals (Sweden)

    Ricardo Ramírez-Barrantes

    2018-06-01

    Full Text Available The transient receptor potential (TRP ion channel family consists of a broad variety of non-selective cation channels that integrate environmental physicochemical signals for dynamic homeostatic control. Involved in a variety of cellular physiological processes, TRP channels are fundamental to the control of the cell life cycle. TRP channels from the vanilloid (TRPV family have been directly implicated in cell death. TRPV1 is activated by pain-inducing stimuli, including inflammatory endovanilloids and pungent exovanilloids, such as capsaicin (CAP. TRPV1 activation by high doses of CAP (>10 μM leads to necrosis, but also exhibits apoptotic characteristics. However, CAP dose–response studies are lacking in order to determine whether CAP-induced cell death occurs preferentially via necrosis or apoptosis. In addition, it is not known whether cytosolic Ca2+ and mitochondrial dysfunction participates in CAP-induced TRPV1-mediated cell death. By using TRPV1-transfected HeLa cells, we investigated the underlying mechanisms involved in CAP-induced TRPV1-mediated cell death, the dependence of CAP dose, and the participation of mitochondrial dysfunction and cytosolic Ca2+ increase. Together, our results contribute to elucidate the pathophysiological steps that follow after TRPV1 stimulation with CAP. Low concentrations of CAP (1 μM induce cell death by a mechanism involving a TRPV1-mediated rapid and transient intracellular Ca2+ increase that stimulates plasma membrane depolarization, thereby compromising plasma membrane integrity and ultimately leading to cell death. Meanwhile, higher doses of CAP induce cell death via a TRPV1-independent mechanism, involving a slow and persistent intracellular Ca2+ increase that induces mitochondrial dysfunction, plasma membrane depolarization, plasma membrane loss of integrity, and ultimately, cell death.

  7. Apoptotic Cell Death Induced by Resveratrol Is Partially Mediated by the Autophagy Pathway in Human Ovarian Cancer Cells.

    Directory of Open Access Journals (Sweden)

    Fangfang Lang

    Full Text Available Resveratrol (trans-3,4,5'-trihydroxystilbene is an active compound in food, such as red grapes, peanuts, and berries. Resveratrol exhibits an anticancer effect on various human cancer cells. However, the mechanism of resveratrol-induced anti-cancer effect at the molecular level remains to be elucidated. In this study, the mechanism underlying the anti-cancer effect of resveratrol in human ovarian cancer cells (OVCAR-3 and Caov-3 was investigated using various molecular biology techniques, such as flow cytometry, western blotting, and RNA interference, with a major focus on the potential role of autophagy in resveratrol-induced apoptotic cell death. We demonstrated that resveratrol induced reactive oxygen species (ROS generation, which triggers autophagy and subsequent apoptotic cell death. Resveratrol induced ATG5 expression and promoted LC3 cleavage. The apoptotic cell death induced by resveratrol was attenuated by both pharmacological and genetic inhibition of autophagy. The autophagy inhibitor chloroquine, which functions at the late stage of autophagy, significantly reduced resveratrol-induced cell death and caspase 3 activity in human ovarian cancer cells. We also demonstrated that targeting ATG5 by siRNA also suppressed resveratrol-induced apoptotic cell death. Thus, we concluded that a common pathway between autophagy and apoptosis exists in resveratrol-induced cell death in OVCAR-3 human ovarian cancer cells.

  8. The contribution of the programmed cell death machinery in innate immune cells to lupus nephritis.

    Science.gov (United States)

    Tsai, FuNien; Perlman, Harris; Cuda, Carla M

    2017-12-01

    Systemic lupus erythematosus (SLE) is a chronic multi-factorial autoimmune disease initiated by genetic and environmental factors, which in combination trigger disease onset in susceptible individuals. Damage to the kidney as a consequence of lupus nephritis (LN) is one of the most prevalent and severe outcomes, as LN affects up to 60% of SLE patients and accounts for much of SLE-associated morbidity and mortality. As remarkable strides have been made in unlocking new inflammatory mechanisms associated with signaling molecules of programmed cell death pathways, this review explores the available evidence implicating the action of these pathways specifically within dendritic cells and macrophages in the control of kidney disease. Although advancements into the underlying mechanisms responsible for inducing cell death inflammatory pathways have been made, there still exist areas of unmet need. By understanding the molecular mechanisms by which dendritic cells and macrophages contribute to LN pathogenesis, we can improve their viability as potential therapeutic targets to promote remission. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Withaferin A Induces Cell Death Selectively in Androgen-Independent Prostate Cancer Cells but Not in Normal Fibroblast Cells.

    Directory of Open Access Journals (Sweden)

    Yukihiro Nishikawa

    Full Text Available Withaferin A (WA, a major bioactive component of the Indian herb Withania somnifera, induces cell death (apoptosis/necrosis in multiple types of tumor cells, but the molecular mechanism underlying this cytotoxicity remains elusive. We report here that 2 μM WA induced cell death selectively in androgen-insensitive PC-3 and DU-145 prostate adenocarcinoma cells, whereas its toxicity was less severe in androgen-sensitive LNCaP prostate adenocarcinoma cells and normal human fibroblasts (TIG-1 and KD. WA also killed PC-3 cells in spheroid-forming medium. DNA microarray analysis revealed that WA significantly increased mRNA levels of c-Fos and 11 heat-shock proteins (HSPs in PC-3 and DU-145, but not in LNCaP and TIG-1. Western analysis revealed increased expression of c-Fos and reduced expression of the anti-apoptotic protein c-FLIP(L. Expression of HSPs such as HSPA6 and Hsp70 was conspicuously elevated; however, because siRNA-mediated depletion of HSF-1, an HSP-inducing transcription factor, reduced PC-3 cell viability, it is likely that these heat-shock genes were involved in protecting against cell death. Moreover, WA induced generation of reactive oxygen species (ROS in PC-3 and DU-145, but not in normal fibroblasts. Immunocytochemistry and immuno-electron microscopy revealed that WA disrupted the vimentin cytoskeleton, possibly inducing the ROS generation, c-Fos expression and c-FLIP(L suppression. These observations suggest that multiple events followed by disruption of the vimentin cytoskeleton play pivotal roles in WA-mediated cell death.

  10. Vacuolar and cytoskeletal dynamics during elicitor-induced programmed cell death in tobacco BY-2 cells.

    Science.gov (United States)

    Higaki, Takumi; Kadota, Yasuhiro; Goh, Tatsuaki; Hayashi, Teruyuki; Kutsuna, Natsumaro; Sano, Toshio; Hasezawa, Seiichiro; Kuchitsu, Kazuyuki

    2008-09-01

    Responses of plant cells to environmental stresses often involve morphological changes, differentiation and redistribution of various organelles and cytoskeletal network. Tobacco BY-2 cells provide excellent model system for in vivo imaging of these intracellular events. Treatment of the cell cycle-synchronized BY-2 cells with a proteinaceous oomycete elicitor, cryptogein, induces highly synchronous programmed cell death (PCD) and provide a model system to characterize vacuolar and cytoskeletal dynamics during the PCD. Sequential observation revealed dynamic reorganization of the vacuole and actin microfilaments during the execution of the PCD. We further characterized the effects cryptogein on mitotic microtubule organization in cell cycle-synchronized cells. Cryptogein treatment at S phase inhibited formation of the preprophase band, a cortical microtubule band that predicts the cell division site. Cortical microtubules kept their random orientation till their disruption that gradually occurred during the execution of the PCD twelve hours after the cryptogein treatment. Possible molecular mechanisms and physiological roles of the dynamic behavior of the organelles and cytoskeletal network in the pathogenic signal-induced PCD are discussed.

  11. 3-Bromopyruvate induces necrotic cell death in sensitive melanoma cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Qin, J.-Z.; Xin, H. [Oncology Institute, Cardinal Bernardin Cancer Center, Loyola University of Chicago Medical Center (United States); Nickoloff, B.J., E-mail: bnickol@lumc.edu [Oncology Institute, Cardinal Bernardin Cancer Center, Loyola University of Chicago Medical Center (United States)

    2010-05-28

    Clinicians successfully utilize high uptake of radiolabeled glucose via PET scanning to localize metastases in melanoma patients. To take advantage of this altered metabolome, 3-bromopyruvate (BrPA) was used to overcome the notorious resistance of melanoma to cell death. Using four melanoma cell lines, BrPA triggered caspase independent necrosis in two lines, whilst the other two lines were resistant to killing. Mechanistically, sensitive cells differed from resistant cells by; constitutively lower levels of glutathione, reduction of glutathione by BrPA only in sensitive cells; increased superoxide anion reactive oxygen species, loss of outer mitochondrial membrane permeability, and rapid ATP depletion. Sensitive cell killing was blocked by N-acetylcysteine or glutathione. When glutathione levels were reduced in resistant cell lines, they became sensitive to killing by BrPA. Taken together, these results identify a metabolic-based Achilles' heel in melanoma cells to be exploited by use of BrPA. Future pre-clinical and clinical trials are warranted to translate these results into improved patient care for individuals suffering from metastatic melanoma.

  12. 3-Bromopyruvate induces necrotic cell death in sensitive melanoma cell lines.

    Science.gov (United States)

    Qin, J-Z; Xin, H; Nickoloff, B J

    2010-05-28

    Clinicians successfully utilize high uptake of radiolabeled glucose via PET scanning to localize metastases in melanoma patients. To take advantage of this altered metabolome, 3-bromopyruvate (BrPA) was used to overcome the notorious resistance of melanoma to cell death. Using four melanoma cell lines, BrPA triggered caspase independent necrosis in two lines, whilst the other two lines were resistant to killing. Mechanistically, sensitive cells differed from resistant cells by; constitutively lower levels of glutathione, reduction of glutathione by BrPA only in sensitive cells; increased superoxide anion reactive oxygen species, loss of outer mitochondrial membrane permeability, and rapid ATP depletion. Sensitive cell killing was blocked by N-acetylcysteine or glutathione. When glutathione levels were reduced in resistant cell lines, they became sensitive to killing by BrPA. Taken together, these results identify a metabolic-based Achilles' heel in melanoma cells to be exploited by use of BrPA. Future pre-clinical and clinical trials are warranted to translate these results into improved patient care for individuals suffering from metastatic melanoma. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  13. 3-Bromopyruvate induces necrotic cell death in sensitive melanoma cell lines

    International Nuclear Information System (INIS)

    Qin, J.-Z.; Xin, H.; Nickoloff, B.J.

    2010-01-01

    Clinicians successfully utilize high uptake of radiolabeled glucose via PET scanning to localize metastases in melanoma patients. To take advantage of this altered metabolome, 3-bromopyruvate (BrPA) was used to overcome the notorious resistance of melanoma to cell death. Using four melanoma cell lines, BrPA triggered caspase independent necrosis in two lines, whilst the other two lines were resistant to killing. Mechanistically, sensitive cells differed from resistant cells by; constitutively lower levels of glutathione, reduction of glutathione by BrPA only in sensitive cells; increased superoxide anion reactive oxygen species, loss of outer mitochondrial membrane permeability, and rapid ATP depletion. Sensitive cell killing was blocked by N-acetylcysteine or glutathione. When glutathione levels were reduced in resistant cell lines, they became sensitive to killing by BrPA. Taken together, these results identify a metabolic-based Achilles' heel in melanoma cells to be exploited by use of BrPA. Future pre-clinical and clinical trials are warranted to translate these results into improved patient care for individuals suffering from metastatic melanoma.

  14. Reactive oxygen species induced by Streptococcus pyogenes invasion trigger apoptotic cell death in infected epithelial cells.

    Science.gov (United States)

    Aikawa, Chihiro; Nozawa, Takashi; Maruyama, Fumito; Tsumoto, Kohei; Hamada, Shigeyuki; Nakagawa, Ichiro

    2010-06-01

    Streptococcus pyogenes (group A streptococcus, GAS), one of the most common pathogens of humans, attaches and invades into human pharyngeal or skin epithelial cells. We have previously reported that induction of apoptosis is associated with GAS invasion, which induces mitochondrial dysfunction and apoptotic cell death. We demonstrate here that GAS-induced apoptosis is mediated by reactive oxygen species (ROS) production. Both the induction of apoptosis and ROS production markedly increased upon invasion of wild-type GAS strain JRS4 into HeLa cells; however, the apoptotic response was not observed in fibronectin-binding protein F1-disrupted mutant SAM1-infected cells. In Bcl-2-overexpressing HeLa cells (HBD98-2-4), the induction of apoptosis, ROS production and mitochondrial dysfunction were significantly suppressed, whereas the numbers of invaded GAS was not different between HeLa (mock cells) and the HeLa HBD98-2-4 cells. Whereas Rac1 activation occurred during GAS invasion, ROS production in GAS-infected cells was clearly inhibited by transfection with the Rac1 mutants (L37 or V12L37), but not by the dominant active mutant (V12L61) or by the dominant negative mutant (N17). These observations indicate that GAS invasion triggers ROS production through Rac1 activation and generated ROS induced mitochondrial dysfunction leading to cellular apoptosis.

  15. Alginate gelation-induced cell death during laser-assisted cell printing

    International Nuclear Information System (INIS)

    Gudapati, Hemanth; Yan, Jingyuan; Huang, Yong; Chrisey, Douglas B

    2014-01-01

    Modified laser-induced forward transfer has emerged as a promising bioprinting technique. Depending on the operating conditions and cell properties, laser cell printing may cause cell injury and even death, which should be carefully elucidated for it to be a viable technology. This study has investigated the effects of alginate gelation, gelation time, alginate concentration, and laser fluence on the post-transfer cell viability of NIH 3T3 fibroblasts. Sodium alginate and calcium chloride are used as the gel precursor and gel reactant solution to form cell-laden alginate microspheres. It is found that the effects of gelation depend on the duration of gelation. Two-minute gelation is observed to increase the cell viability after 24 h incubation, mainly due to the protective cushion effect of the forming gel membrane during droplet landing. Despite the cushion effect from 10 min gelation, it is observed that the cell viability decreases after 24 h incubation because of the forming thick gel membrane that reduces nutrient and oxygen diffusion from the culture medium. In addition, the cell viability after 24 h incubation decreases as the laser fluence or alginate concentration increases. (paper)

  16. SRT1720 induces lysosomal-dependent cell death of breast cancer cells.

    Science.gov (United States)

    Lahusen, Tyler J; Deng, Chu-Xia

    2015-01-01

    SRT1720 is an activator of SIRT1, a NAD(+)-dependent protein and histone deacetylase that plays an important role in numerous biologic processes. Several studies have illustrated that SRT1720 treatment could improve metabolic conditions in mouse models and in a study in cancer SRT1720 caused increased apoptosis of myeloma cells. However, the effect of SRT1720 on cancer may be complex, as some recent studies have demonstrated that SRT1720 may not directly activate SIRT1 and another study showed that SRT1720 treatment could promote lung metastasis. To further investigate the role of SRT1720 in breast cancer, we treated SIRT1 knockdown and control breast cancer cell lines with SRT1720 both in vitro and in vivo. We showed that SRT1720 more effectively decreased the viability of basal-type MDA-MB-231 and BT20 cells as compared with luminal-type MCF-7 breast cancer cells or nontumorigenic MCF-10A cells. We demonstrated that SRT1720 induced lysosomal membrane permeabilization and necrosis, which could be blocked by lysosomal inhibitors. In contrast, SRT1720-induced cell death occurred in vitro irrespective of SIRT1 status, whereas in nude mice, SRT1720 exhibited a more profound effect in inhibiting the growth of allograft tumors of SIRT1 proficient cells as compared with tumors of SIRT1-deficient cells. Thus, SRT1720 causes lysosomal-dependent necrosis and may be used as a therapeutic agent for breast cancer treatment. ©2014 American Association for Cancer Research.

  17. Genetically induced cell death in bulge stem cells reveals their redundancy for hair and epidermal regeneration.

    Science.gov (United States)

    Driskell, Iwona; Oeztuerk-Winder, Feride; Humphreys, Peter; Frye, Michaela

    2015-03-01

    Adult mammalian epidermis contains multiple stem cell populations in which quiescent and more proliferative stem and progenitor populations coexist. However, the precise interrelation of these populations in homeostasis remains unclear. Here, we blocked the contribution of quiescent keratin 19 (K19)-expressing bulge stem cells to hair follicle formation through genetic ablation of the essential histone methyltransferase Setd8 that is required for the maintenance of adult skin. Deletion of Setd8 eliminated the contribution of bulge cells to hair follicle regeneration through inhibition of cell division and induction of cell death, but the growth and morphology of hair follicles were unaffected. Furthermore, ablation of Setd8 in the hair follicle bulge blocked the contribution of K19-postive stem cells to wounded epidermis, but the wound healing process was unaltered. Our data indicate that quiescent bulge stem cells are dispensable for hair follicle regeneration and epidermal injury in the short term and support the hypothesis that quiescent and cycling stem cell populations are equipotent. © 2014 AlphaMed Press.

  18. Mechanisms underlying 3-bromopyruvate-induced cell death in colon cancer.

    Science.gov (United States)

    Sun, Yiming; Liu, Zhe; Zou, Xue; Lan, Yadong; Sun, Xiaojin; Wang, Xiu; Zhao, Surong; Jiang, Chenchen; Liu, Hao

    2015-08-01

    3-Bromopyruvate (3BP) is an energy-depleting drug that inhibits Hexokinase II activity by alkylation during glycolysis, thereby suppressing the production of ATP and inducing cell death. As such, 3BP can potentially serve as an anti-tumorigenic agent. Our previous research showed that 3BP can induce apoptosis via AKT /protein Kinase B signaling in breast cancer cells. Here we found that 3BP can also induce colon cancer cell death by necroptosis and apoptosis at the same time and concentration in the SW480 and HT29 cell lines; in the latter, autophagy was also found to be a mechanism of cell death. In HT29 cells, combined treatment with 3BP and the autophagy inhibitor 3-methyladenine (3-MA) exacerbated cell death, while viability in 3BP-treated cells was enhanced by concomitant treatment with the caspase inhibitor benzyloxycarbonyl-Val-Ala-Asp fluoromethylketone (z-VAD-fmk) and the necroptosis inhibitor necrostatin (Nec)-1. Moreover, 3BP inhibited tumor growth in a SW480 xenograft mouse model. These results indicate that 3BP can suppress tumor growth and induce cell death by multiple mechanisms at the same time and concentration in different types of colon cancer cell by depleting cellular energy stores.

  19. Inhibition of thromboxane synthase induces lung cancer cell death via increasing the nuclear p27

    International Nuclear Information System (INIS)

    Leung, Kin Chung; Hsin, Michael K.Y.; Chan, Joey S.Y.; Yip, Johnson H.Y.; Li, Mingyue; Leung, Billy C.S.; Mok, Tony S.K.; Warner, Timothy D.; Underwood, Malcolm J.; Chen, George G.

    2009-01-01

    The role of thromboxane in lung carcinogenesis is not clearly known, though thromboxane B2 (TXB 2 ) level is increased and antagonists of thromboxane receptors or TXA2 can induce apoptosis of lung cancer cells. p27, an atypical tumor suppressor, is normally sequestered in the nucleus. The increased nuclear p27 may result in apoptosis of tumor cells. We hypothesize that the inhibition of thromboxane synthase (TXS) induces the death of lung cancer cells and that such inhibition is associated with the nuclear p27 level. Our experiment showed that the inhibition of TXS significantly induced the death or apoptosis in lung cancer cells. The activity of TXS was increased in lung cancer. The nuclear p27 was remarkably reduced in lung cancer tissues. The inhibition of TXS caused the cell death and apoptosis of lung cancer cells, likely via the elevation of the nuclear p27 since the TXS inhibition promoted the nuclear p27 level and the inhibition of p27 by its siRNA recovered the cell death induced by TXS inhibition. Collectively, lung cancer cells produce high levels of TXB 2 but their nuclear p27 is markedly reduced. The inhibition of TXS results in the p27-related induction of cell death in lung cancer cells.

  20. Inhibition of thromboxane synthase induces lung cancer cell death via increasing the nuclear p27

    Energy Technology Data Exchange (ETDEWEB)

    Leung, Kin Chung; Hsin, Michael K.Y.; Chan, Joey S.Y.; Yip, Johnson H.Y.; Li, Mingyue; Leung, Billy C.S. [Department of Surgery, The Chinese University of Hong Kong, Shatin, New Territories (Hong Kong); Mok, Tony S.K. [Department of Clinical Oncology, The Chinese University of Hong Kong, Shatin, New Territories (Hong Kong); Warner, Timothy D. [The William Harvey Research Institute, Queen Mary University of London, London (United Kingdom); Underwood, Malcolm J. [Department of Surgery, The Chinese University of Hong Kong, Shatin, New Territories (Hong Kong); Chen, George G., E-mail: gchen@cuhk.edu.hk [Department of Surgery, The Chinese University of Hong Kong, Shatin, New Territories (Hong Kong)

    2009-10-15

    The role of thromboxane in lung carcinogenesis is not clearly known, though thromboxane B2 (TXB{sub 2}) level is increased and antagonists of thromboxane receptors or TXA2 can induce apoptosis of lung cancer cells. p27, an atypical tumor suppressor, is normally sequestered in the nucleus. The increased nuclear p27 may result in apoptosis of tumor cells. We hypothesize that the inhibition of thromboxane synthase (TXS) induces the death of lung cancer cells and that such inhibition is associated with the nuclear p27 level. Our experiment showed that the inhibition of TXS significantly induced the death or apoptosis in lung cancer cells. The activity of TXS was increased in lung cancer. The nuclear p27 was remarkably reduced in lung cancer tissues. The inhibition of TXS caused the cell death and apoptosis of lung cancer cells, likely via the elevation of the nuclear p27 since the TXS inhibition promoted the nuclear p27 level and the inhibition of p27 by its siRNA recovered the cell death induced by TXS inhibition. Collectively, lung cancer cells produce high levels of TXB{sub 2} but their nuclear p27 is markedly reduced. The inhibition of TXS results in the p27-related induction of cell death in lung cancer cells.

  1. Methadone induces CAD degradation and AIF-mediated necrotic-like cell death in neuroblastoma cells.

    Science.gov (United States)

    Perez-Alvarez, Sergio; Iglesias-Guimarais, Victoria; Solesio, María E; Melero-Fernandez de Mera, Raquel María; Yuste, Víctor J; Galindo, María F; Jordán, Joaquín

    2011-04-01

    Methadone (d,l-methadone hydrochloride) is a full-opioid agonist, originally developed as a substitution for heroin or other opiates abusers. Nowadays methadone is also being applied as long-lasting analgesics in cancer, and it is proposed as a promising agent for leukemia therapy. Previously, we have demonstrated that high concentrations of methadone (0.5mM) induced necrotic-like cell death in SH-SY5Y cells. The pathway involved is caspase-independent but involves impairment of mitochondrial ATP synthesis and mitochondrial cytochrome c release. However, the downstream mitochondrial pathways remained unclear. Here, we studied the participation of apoptosis inducing factor (AIF) in methadone-induced cell death. Methadone resulted in a translocation of AIF from mitochondria to the nucleus. Translocation was inhibited by cyclosporine A, but not by lack of Bax protein. Therefore the effect seems mediated by the formation of the mitochondrial transition pore, but is apparently independent of Bax. Furthermore, methadone-treated SH-SY5Y nuclei show characteristics that are typical for stage I nuclear condensation. Methadone did not induce degradation of DNA into oligonucleosomal fragments or into high molecular weight DNA fragments. Absence of DNA fragmentation coincided with a considerable decrease in the levels of the caspase-actived endonuclase DNase and its chaperone-inhibitor ICAD. In conclusion, our results provide mechanistic insights into the molecular mechanisms that underlie methadone-induced cell death. This knowledge may prove useful to develop novel strategies to prevent toxic side-effects of methadone thereby sustaining its use as therapeutical agent against tumors. Copyright © 2010 Elsevier Ltd. All rights reserved.

  2. Delayed reproductive death as a dominant phenotype in cell clones surviving X-irradiation

    International Nuclear Information System (INIS)

    Chang, W.P.; Little, J.B.

    1992-01-01

    Residual damage manifested as reduced cloning efficiency was observed in many of the cloned progeny of Chinese hamster ovary (CHO) cells and human carcinoma SQ-20B cells surviving X-irradiation. This stable phenotype, which we have termed delayed reproductive death, persisted for >50 generations of cell replication post-irradiation. Clones showing this phenotype were aneuploid, and formed colonies with a high proportion of giant cells. By somatic cell hybridization of CHO clones, the delayed reproductive death phenotype was found to be a dominant trait; the cloning efficiency of hybrid clones was persistently depressed, as compared with that of control hybrid cells. These results suggest that delayed reproductive death represents a specific cellular response that may persist in some of the progeny of mammalian cells for long periods after X-irradiation. (author)

  3. Cell death by SecTRAPs: thioredoxin reductase as a prooxidant killer of cells.

    Directory of Open Access Journals (Sweden)

    Karin Anestål

    Full Text Available BACKGROUND: SecTRAPs (selenium compromised thioredoxin reductase-derived apoptotic proteins can be formed from the selenoprotein thioredoxin reductase (TrxR by targeting of its selenocysteine (Sec residue with electrophiles, or by its removal through C-terminal truncation. SecTRAPs are devoid of thioredoxin reductase activity but can induce rapid cell death in cultured cancer cell lines by a gain of function. PRINCIPAL FINDINGS: Both human and rat SecTRAPs killed human A549 and HeLa cells. The cell death displayed both apoptotic and necrotic features. It did not require novel protein synthesis nor did it show extensive nuclear fragmentation, but it was attenuated by use of caspase inhibitors. The redox active disulfide/dithiol motif in the N-terminal domain of TrxR had to be maintained for manifestation of SecTRAP cytotoxicity. Stopped-flow kinetics showed that NADPH can reduce the FAD moiety in SecTRAPs at similar rates as in native TrxR and purified SecTRAPs could maintain NADPH oxidase activity, which was accelerated by low molecular weight substrates such as juglone. In a cellular context, SecTRAPs triggered extensive formation of reactive oxygen species (ROS and consequently antioxidants could protect against the cell killing by SecTRAPs. CONCLUSIONS: We conclude that formation of SecTRAPs could contribute to the cytotoxicity seen upon exposure of cells to electrophilic agents targeting TrxR. SecTRAPs are prooxidant killers of cells, triggering mechanisms beyond those of a mere loss of thioredoxin reductase activity.

  4. Bar represses dPax2 and decapentaplegic to regulate cell fate and morphogenetic cell death in Drosophila eye.

    Directory of Open Access Journals (Sweden)

    Jongkyun Kang

    Full Text Available The coordinated regulation of cell fate and cell survival is crucial for normal pattern formation in developing organisms. In Drosophila compound eye development, crystalline arrays of hexagonal ommatidia are established by precise assembly of diverse cell types, including the photoreceptor cells, cone cells and interommatidial (IOM pigment cells. The molecular basis for controlling the number of cone and IOM pigment cells during ommatidial pattern formation is not well understood. Here we present evidence that BarH1 and BarH2 homeobox genes are essential for eye patterning by inhibiting excess cone cell differentiation and promoting programmed death of IOM cells. Specifically, we show that loss of Bar from the undifferentiated retinal precursor cells leads to ectopic expression of Prospero and dPax2, two transcription factors essential for cone cell specification, resulting in excess cone cell differentiation. We also show that loss of Bar causes ectopic expression of the TGFβ homolog Decapentaplegic (Dpp posterior to the morphogenetic furrow in the larval eye imaginal disc. The ectopic Dpp expression is not responsible for the formation of excess cone cells in Bar loss-of-function mutant eyes. Instead, it causes reduction in IOM cell death in the pupal stage by antagonizing the function of pro-apoptotic gene reaper. Taken together, this study suggests a novel regulatory mechanism in the control of developmental cell death in which the repression of Dpp by Bar in larval eye disc is essential for IOM cell death in pupal retina.

  5. Patterns of cell proliferation and cell death in the developing retina and optic tectum of the brown trout.

    NARCIS (Netherlands)

    Candal, E.; Anadon, R.; Grip, W.J. de; Rodriguez-Moldes, I.

    2005-01-01

    We have analyzed the patterns of cell proliferation and cell death in the retina and optic tectum of the brown trout (Salmo trutta fario) throughout embryonic and postembryonic stages. Cell proliferation was detected by immunohistochemistry with an antibody against the proliferating cell nuclear

  6. Cell death in the pathogenesis of systemic lupus erythematosus and lupus nephritis.

    Science.gov (United States)

    Mistry, Pragnesh; Kaplan, Mariana J

    2017-12-01

    Nephritis is one of the most severe complications of systemic lupus erythematosus (SLE). One key characteristic of lupus nephritis (LN) is the deposition of immune complexes containing nucleic acids and/or proteins binding to nucleic acids and autoantibodies recognizing these molecules. A variety of cell death processes are implicated in the generation and externalization of modified nuclear autoantigens and in the development of LN. Among these processes, apoptosis, primary and secondary necrosis, NETosis, necroptosis, pyroptosis, and autophagy have been proposed to play roles in tissue damage and immune dysregulation. Cell death occurs in healthy individuals during conditions of homeostasis yet autoimmunity does not develop, at least in part, because of rapid clearance of dying cells. In SLE, accelerated cell death combined with a clearance deficiency may lead to the accumulation and externalization of nuclear autoantigens and to autoantibody production. In addition, specific types of cell death may modify autoantigens and alter their immunogenicity. These modified molecules may then become novel targets of the immune system and promote autoimmune responses in predisposed hosts. In this review, we examine various cell death pathways and discuss how enhanced cell death, impaired clearance, and post-translational modifications of proteins could contribute to the development of lupus nephritis. Published by Elsevier Inc.

  7. Autophagy protects against neural cell death induced by piperidine alkaloids present in Prosopis juliflora (Mesquite).

    Science.gov (United States)

    Silva, Victor D A; Cuevas, Carlos; Muñoz, Patricia; Villa, Monica; Ahumada-Castro, Ulises; Huenchuguala, Sandro; Santos, Cleonice C Dos; Araujo, Fillipe M DE; Ferreira, Rafael S; Silva, Vanessa B DA; Silva, Juliana H C E; Soares, Érica N; Velozo, Eudes S; Segura-Aguilar, Juan; Costa, Silvia L

    2017-01-01

    Prosopis juliflora is a shrub that has been used to feed animals and humans. However, a synergistic action of piperidine alkaloids has been suggested to be responsible for neurotoxic damage observed in animals. We investigated the involvement of programmed cell death (PCD) and autophagy on the mechanism of cell death induced by a total extract (TAE) of alkaloids and fraction (F32) from P. juliflora leaves composed majoritary of juliprosopine in a model of neuron/glial cell co-culture. We saw that TAE (30 µg/mL) and F32 (7.5 µg/mL) induced reduction in ATP levels and changes in mitochondrial membrane potential at 12 h exposure. Moreover, TAE and F32 induced caspase-9 activation, nuclear condensation and neuronal death at 16 h exposure. After 4 h, they induced autophagy characterized by decreases of P62 protein level, increase of LC3II expression and increase in number of GFP-LC3 cells. Interestingly, we demonstrated that inhibition of autophagy by bafilomycin and vinblastine increased the cell death induced by TAE and autophagy induced by serum deprivation and rapamycin reduced cell death induced by F32 at 24 h. These results indicate that the mechanism neural cell death induced by these alkaloids involves PCD via caspase-9 activation and autophagy, which seems to be an important protective mechanism.

  8. Autophagy protects against neural cell death induced by piperidine alkaloids present in Prosopis juliflora (Mesquite

    Directory of Open Access Journals (Sweden)

    VICTOR D.A. SILVA

    Full Text Available ABSTRACT Prosopis juliflora is a shrub that has been used to feed animals and humans. However, a synergistic action of piperidine alkaloids has been suggested to be responsible for neurotoxic damage observed in animals. We investigated the involvement of programmed cell death (PCD and autophagy on the mechanism of cell death induced by a total extract (TAE of alkaloids and fraction (F32 from P. juliflora leaves composed majoritary of juliprosopine in a model of neuron/glial cell co-culture. We saw that TAE (30 µg/mL and F32 (7.5 µg/mL induced reduction in ATP levels and changes in mitochondrial membrane potential at 12 h exposure. Moreover, TAE and F32 induced caspase-9 activation, nuclear condensation and neuronal death at 16 h exposure. After 4 h, they induced autophagy characterized by decreases of P62 protein level, increase of LC3II expression and increase in number of GFP-LC3 cells. Interestingly, we demonstrated that inhibition of autophagy by bafilomycin and vinblastine increased the cell death induced by TAE and autophagy induced by serum deprivation and rapamycin reduced cell death induced by F32 at 24 h. These results indicate that the mechanism neural cell death induced by these alkaloids involves PCD via caspase-9 activation and autophagy, which seems to be an important protective mechanism.

  9. Exploration of 'over kill effect' of high-LET Ar- and Fe-ions by evaluating the fraction of non-hit cell and interphase death

    International Nuclear Information System (INIS)

    Mehnati, P.; Sasaki, Hiroshi; Morimoto, Shigeko; Yatagai, Fumio; Hanaoka, Fumio; Furusawa, Yoshiya; Kanai, Tatsuaki; Kobayashi, Yasuhiko; Wada, Seiichi

    2005-01-01

    The reason why relative biological effectiveness (RBE) for cell killing fell to less than unity (1.0) with very high-linear energy transfer (LET) heavy-ions ( 40 Ar: 1,640 keV/μm; 56 Fe: 780, 1,200, 2,000 keV/μm) was explored by evaluating the fraction of non-hit cell (time-lapse observation) and cells undergoing interphase death (calculation based on our previous data). Chinese hamster ovary (CHO) cells were exposed to 4 Gy (30% survival dose) of Ar (1,640 keV/μm) or Fe-ions (2,000 keV/μm). About 20% of all cells were judged to be non-hit, and about 10% cells survived radiation damage. About 70% cells died after dividing at least once (reproductive death) or without dividing (interphase death). RBE for reproductive (RBE[R]) and interphase (RBE[I]) death showed a similar LET dependence with maximum around 200 keV/μm. In this LET region, at 30% survival level, about 10% non-survivors underwent interphase death. The corresponding value for very high-LET Fe-ions (2,000 keV/μm) was not particularly high (-15%), whereas that for X-rays was less than 3%. However, reproductive death (67%) predominated over interphase death (33%) even in regard to rather severely damaged cells (1% survival level) after exposure to Fe-ions (2,000 keV/μm). These indicate that interphase death is a type of cell death characteristic for the cells exposed to high-LET radiation and is not caused by 'cellular over kill effect'. Both NHF37 (non-hit fraction at 37% survival) and inactivation cross-section for reproductive death (σ[R]) began to increase when LET exceeded 100 keV/μm. The exclusion of non-hit fraction in the calculation of surviving fraction partially prevented the fall of RBE[R] when LET exceeded 200 keV/μm. On the other hand, the mean number of lethal damage per unit dose (NLD/Gy) showed the same LET-dependent pattern as RBE[R]. These suggest that the increase in non-hit fraction and σ[R] with an increasing LET is caused by enhanced clustering of ionization and DNA damage

  10. Two modes of cell death caused by exposure to nanosecond pulsed electric field.

    Directory of Open Access Journals (Sweden)

    Olga N Pakhomova

    Full Text Available High-amplitude electric pulses of nanosecond duration, also known as nanosecond pulsed electric field (nsPEF, are a novel modality with promising applications for cell stimulation and tissue ablation. However, key mechanisms responsible for the cytotoxicity of nsPEF have not been established. We show that the principal cause of cell death induced by 60- or 300-ns pulses in U937 cells is the loss of the plasma membrane integrity ("nanoelectroporation", leading to water uptake, cell swelling, and eventual membrane rupture. Most of this early necrotic death occurs within 1-2 hr after nsPEF exposure. The uptake of water is driven by the presence of pore-impermeable solutes inside the cell, and can be counterbalanced by the presence of a pore-impermeable solute such as sucrose in the medium. Sucrose blocks swelling and prevents the early necrotic death; however the long-term cell survival (24 and 48 hr does not significantly change. Cells protected with sucrose demonstrate higher incidence of the delayed death (6-24 hr post nsPEF. These cells are more often positive for the uptake of an early apoptotic marker dye YO-PRO-1 while remaining impermeable to propidium iodide. Instead of swelling, these cells often develop apoptotic fragmentation of the cytoplasm. Caspase 3/7 activity increases already in 1 hr after nsPEF and poly-ADP ribose polymerase (PARP cleavage is detected in 2 hr. Staurosporin-treated positive control cells develop these apoptotic signs only in 3 and 4 hr, respectively. We conclude that nsPEF exposure triggers both necrotic and apoptotic pathways. The early necrotic death prevails under standard cell culture conditions, but cells rescued from the necrosis nonetheless die later on by apoptosis. The balance between the two modes of cell death can be controlled by enabling or blocking cell swelling.

  11. Programmes of cell death and autolysis in tracheary elements: when a suicidal cell arranges its own corpse removal.

    Science.gov (United States)

    Escamez, Sacha; Tuominen, Hannele

    2014-03-01

    Tracheary element (TE) differentiation represents a unique system to study plant developmental programmed cell death (PCD). TE PCD occurs after deposition of the secondary cell walls when an unknown signal induces tonoplast rupture and the arrest of cytoplasmic streaming. TE PCD is tightly followed by autolysis of the protoplast and partial hydrolysis of the primary cell walls. This review integrates TE differentiation, programmed cell death (PCD), and autolysis in a biological and evolutionary context. The collective evidence from the evolutionary and molecular studies suggests that TE differentiation consists primarily of a programme for cell death and autolysis under the direct control of the transcriptional master switches VASCULAR NAC DOMAIN 6 (VND6) and VND7. In this scenario, secondary cell walls represent a later innovation to improve the water transport capacity of TEs which necessitates transcriptional regulators downstream of VND6 and VND7. One of the most fascinating features of TEs is that they need to prepare their own corpse removal by expression and accumulation of hydrolases that are released from the vacuole after TE cell death. Therefore, TE differentiation involves, in addition to PCD, a programmed autolysis which is initiated before cell death and executed post-mortem. It has recently become clear that TE PCD and autolysis are separate processes with separate molecular regulation. Therefore, the importance of distinguishing between the cell death programme per se and autolysis in all plant PCD research and of careful description of the morphological, biochemical, and molecular sequences in each of these processes, is advocated.

  12. Rational Design of Regulators of Programmed Cell Death in Human Breast Cancer

    National Research Council Canada - National Science Library

    Cowburn, David

    2000-01-01

    The purpose of this research is to develop a better understanding of the intricate pathways of cell death and their contributions to breast cancers, with the goal of designing potential therapeutic...

  13. Catalase and NO CATALASE ACTIVITY1 Promote Autophagy-Dependent Cell Death in Arabidopsis

    DEFF Research Database (Denmark)

    Hackenberg, Thomas; Juul, Trine Maxel; Auzina, Aija

    2013-01-01

    Programmed cell death often depends on generation of reactive oxygen species, which can be detoxified by antioxidative enzymes, including catalases. We previously isolated catalase-deficient mutants (cat2) in a screen for resistance to hydroxyurea-induced cell death. Here, we identify...... an Arabidopsis thaliana hydroxyurea-resistant autophagy mutant, atg2, which also shows reduced sensitivity to cell death triggered by the bacterial effector avrRpm1. To test if catalase deficiency likewise affected both hydroxyurea and avrRpm1 sensitivity, we selected mutants with extremely low catalase...... activities and showed that they carried mutations in a gene that we named NO CATALASE ACTIVITY1 (NCA1). nca1 mutants showed severely reduced activities of all three catalase isoforms in Arabidopsis, and loss of NCA1 function led to strong suppression of RPM1-triggered cell death. Basal and starvation...

  14. A shift to organismal stress resistance in programmed cell death mutants.

    Directory of Open Access Journals (Sweden)

    Meredith E Judy

    Full Text Available Animals have many ways of protecting themselves against stress; for example, they can induce animal-wide, stress-protective pathways and they can kill damaged cells via apoptosis. We have discovered an unexpected regulatory relationship between these two types of stress responses. We find that C. elegans mutations blocking the normal course of programmed cell death and clearance confer animal-wide resistance to a specific set of environmental stressors; namely, ER, heat and osmotic stress. Remarkably, this pattern of stress resistance is induced by mutations that affect cell death in different ways, including ced-3 (cell death defective mutations, which block programmed cell death, ced-1 and ced-2 mutations, which prevent the engulfment of dying cells, and progranulin (pgrn-1 mutations, which accelerate the clearance of apoptotic cells. Stress resistance conferred by ced and pgrn-1 mutations is not additive and these mutants share altered patterns of gene expression, suggesting that they may act within the same pathway to achieve stress resistance. Together, our findings demonstrate that programmed cell death effectors influence the degree to which C. elegans tolerates environmental stress. While the mechanism is not entirely clear, it is intriguing that animals lacking the ability to efficiently and correctly remove dying cells should switch to a more global animal-wide system of stress resistance.

  15. Methuosis: nonapoptotic cell death associated with vacuolization of macropinosome and endosome compartments.

    Science.gov (United States)

    Maltese, William A; Overmeyer, Jean H

    2014-06-01

    Apoptosis is the most widely recognized form of physiological programmed cell death. During the past three decades, various nonapoptotic forms of cell death have gained increasing attention, largely because of their potential importance in pathological processes, toxicology, and cancer therapy. A recent addition to the panoply of cell death phenotypes is methuosis. The neologism is derived from the Greek methuo (to drink to intoxication) because the hallmark of this form of cell death is displacement of the cytoplasm by large fluid-filled vacuoles derived from macropinosomes. The demise of the cell resembles many forms of necrosis, insofar as there is a loss of metabolic capacity and plasma membrane integrity, without the cell shrinkage and nuclear fragmentation associated with apoptosis. Methuosis was initially defined in glioblastoma cells after ectopic expression of activated Ras, but recent reports have described small molecules that can induce the features of methuosis in a broad spectrum of cancer cells, including those that are resistant to conventional apoptosis-inducing drugs. This review summarizes the available information about the distinguishing morphological characteristics and underlying mechanisms of methuosis. We compare and contrast methuosis with other cytopathological conditions in which accumulation of clear cytoplasmic vacuoles is a prominent feature. Finally, we highlight key questions that need to be answered to determine whether methuosis truly represents a unique form of regulated cell death. Copyright © 2014 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  16. Bubbling cell death: A hot air balloon released from the nucleus in the cold.

    Science.gov (United States)

    Chang, Nan-Shan

    2016-06-01

    Cell death emanating from the nucleus is largely unknown. In our recent study, we determined that when temperature is lowered in the surrounding environment, apoptosis stops and bubbling cell death (BCD) occurs. The study concerns the severity of frostbite. When exposed to severe cold and strong ultraviolet (UV) irradiation, people may suffer serious damages to the skin and internal organs. This ultimately leads to limb amputations, organ failure, and death. BCD is defined as "formation of a single bubble from the nucleus per cell and release of this swelling bubble from the cell surface to extracellular space that causes cell death." When cells are subjected to UV irradiation and/or brief cold shock (4℃ for 5 min) and then incubated at room temperature or 4℃ for time-lapse microscopy, each cell releases an enlarging nuclear gas bubble containing nitric oxide. Certain cells may simultaneously eject hundreds or thousands of exosome-like particles. Unlike apoptosis, no phosphatidylserine flip-over, mitochondrial apoptosis, damage to Golgi complex, and chromosomal DNA fragmentation are shown in BCD. When the temperature is increased back at 37℃, bubble formation stops and apoptosis restarts. Mechanistically, proapoptotic WW domain-containing oxidoreductase and p53 block the protective TNF receptor adaptor factor 2 that allows nitric oxide synthase 2 to synthesize nitric oxide and bubble formation. In this mini-review, updated knowledge in cell death and the proposed molecular mechanism for BCD are provided. © 2016 by the Society for Experimental Biology and Medicine.

  17. VMP1 related autophagy and apoptosis in colorectal cancer cells: VMP1 regulates cell death

    Energy Technology Data Exchange (ETDEWEB)

    Qian, Qinyi [Department of Ultrasonograph, Changshu No. 2 People’s Hospital, Changshu (China); Zhou, Hao; Chen, Yan [Department of General Surgery, The First Affiliated Hospital of Soochow University, Suzhou (China); Shen, Chenglong [Department of General Surgery, Changshu No. 2 People’s Hospital, Changshu (China); He, Songbing; Zhao, Hua; Wang, Liang [Department of General Surgery, The First Affiliated Hospital of Soochow University, Suzhou (China); Wan, Daiwei, E-mail: 372710369@qq.com [Department of Hepatobiliary Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou (China); Gu, Wen, E-mail: 505339704@qq.com [Department of General Surgery, The First Affiliated Hospital of Soochow University, Suzhou (China)

    2014-01-17

    Highlights: •This research confirmed VMP1 as a regulator of autophagy in colorectal cancer cell lines. •We proved the pro-survival role of VMP1-mediated autophagy in colorectal cancer cell lines. •We found the interaction between VMP1 and BECLIN1 also existing in colorectal cancer cell lines. -- Abstract: Vacuole membrane protein 1 (VMP1) is an autophagy-related protein and identified as a key regulator of autophagy in recent years. In pancreatic cell lines, VMP1-dependent autophagy has been linked to positive regulation of apoptosis. However, there are no published reports on the role of VMP1 in autophagy and apoptosis in colorectal cancers. Therefore, to address this gap of knowledge, we decided to interrogate regulation of autophagy and apoptosis by VMP1. We have studied the induction of autophagy by starvation and rapamycin treatment in colorectal cell lines using electron microscopy, immunofluorescence, and immunoblotting. We found that starvation-induced autophagy correlated with an increase in VMP1 expression, that VMP1 interacted with BECLIN1, and that siRNA mediated down-regulation of VMP1-reduced autophagy. Next, we examined the relationship between VMP1-dependent autophagy and apoptosis and found that VMP1 down-regulation sensitizes cells to apoptosis and that agents that induce apoptosis down-regulate VMP1. In conclusion, similar to its reported role in other cell types, VMP1 is an important regulator of autophagy in colorectal cell lines. However, in contrast to its role in pancreatic cell lines, in colorectal cancer cells, VMP1-dependent autophagy appears to be pro-survival rather than pro-cell death.

  18. Cell life and death in the anterior pituitary gland: role of oestrogens.

    Science.gov (United States)

    Seilicovich, A

    2010-07-01

    Apoptotic processes play an important role in the maintenance of cell numbers in the anterior pituitary gland during physiological endocrine events. In this review, we summarise the regulation of apoptosis of anterior pituitary cells, particularly lactotrophs, somatotrophs and gonadotrophs, and analyse the possible mechanisms involved in oestrogen-induced apoptosis in anterior pituitary cells. Oestrogens exert apoptotic actions in several cell types and act as modulators of pituitary cell renewal, sensitising cells to both mitogenic and apoptotic signals. Local synthesis of growth factors and cytokines induced by oestradiol as well as changes in phenotypic features that enhance the responsiveness of anterior pituitary cells to pro-apoptotic factors may account for cyclical apoptotic activity in anterior pituitary cells during the oestrous cycle. Considering that tissue homeostasis results from a balance between cell proliferation and death and that mechanisms involved in apoptosis are tightly regulated, defects in cell death processes could have a considerable physiopathological impact.

  19. Sodium nitroprusside induces autophagic cell death in glutathione-depleted osteoblasts.

    Science.gov (United States)

    Son, Min Jeong; Lee, Seong-Beom; Byun, Yu Jeong; Lee, Hwa Ok; Kim, Ho-Shik; Kwon, Oh-Joo; Jeong, Seong-Whan

    2010-01-01

    Previous studies reported that high levels of nitric oxide (NO) induce apoptotic cell death in osteoblasts. We examined molecular mechanisms of cytotoxic injury induced by sodium nitroprusside (SNP), a NO donor, in both glutathione (GSH)-depleted and control U2-OS osteoblasts. Cell viability was reduced by much lower effective concentrations of SNP in GSH-depleted cells compared to normal cells. The data suggest that the level of intracellular GSH is critical in SNP-induced cell death processes of osteoblasts. The level of oxidative stress due to SNP treatments doubled in GSH-depleted cells when measured with fluorochrome H2DCFDA. Pretreatment with the NO scavenger PTIO preserved the viability of cells treated with SNP. Viability of cells treated with SNP was recovered by pretreatment with Wortmannin, an autophagy inhibitor, but not by pretreatment with zVAD-fmk, a pan-specific caspase inhibitor. Large increases of LC3-II were shown by immunoblot analysis of the SNP-treated cells, and the increase was blocked by pretreatment with PTIO or Wortmannin; this implies that under GSH-depleted conditions SNP induces different molecular signaling that lead to autophagic cell death. The ultrastructural morphology of SNP-treated cells in transmission electron microscopy showed numerous autophagic vacuoles. These data suggest NO produces oxidative stress and cellular damage that culminate in autophagic cell death of GSH-depleted osteoblasts. Copyright 2010 Wiley Periodicals, Inc.

  20. Ouabain exacerbates activation-induced cell death in human peripheral blood lymphocytes

    OpenAIRE

    Esteves Mabel B.; Marques-Santos Luis F.; Affonso-Mitidieri Ottília R.; Rumjanek Vivian M.

    2005-01-01

    Lymphocytes activated by mitogenic lectins display changes in transmembrane potential, an elevation in the cytoplasmic Ca2+ concentrations, proliferation and/or activation induced cell death. Low concentrations of ouabain (an inhibitor of Na+,K+-ATPase) suppress mitogen-induced proliferation and increases cell death. To understand the mechanisms involved, a number of parameters were analyzed using fluorescent probes and flow cytometry. The addition of 100nM ouabain to cultures of peripheral b...

  1. Knockout of Arabidopsis accelerated-cell-death11 encoding a sphingosine transfer protein causes activation of programmed cell death and defense

    DEFF Research Database (Denmark)

    Brodersen, Peter; Petersen, Morten; Pike, Helen M

    2002-01-01

    by avirulent pathogens. Global transcriptional changes during programmed cell death (PCD) and defense activation in acd11 were monitored by cDNA microarray hybridization. The PCD and defense pathways activated in acd11 are salicylic acid (SA) dependent, but do not require intact jasmonic acid or ethylene...

  2. Using stochastic cell division and death to probe minimal units of cellular replication

    Science.gov (United States)

    Chib, Savita; Das, Suman; Venkatesan, Soumya; Sai Narain Seshasayee, Aswin; Thattai, Mukund

    2018-03-01

    The invariant cell initiation mass measured in bacterial growth experiments has been interpreted as a minimal unit of cellular replication. Here we argue that the existence of such minimal units induces a coupling between the rates of stochastic cell division and death. To probe this coupling we tracked live and dead cells in Escherichia coli populations treated with a ribosome-targeting antibiotic. We find that the growth exponent from macroscopic cell growth or decay measurements can be represented as the difference of microscopic first-order cell division and death rates. The boundary between cell growth and decay, at which the number of live cells remains constant over time, occurs at the minimal inhibitory concentration (MIC) of the antibiotic. This state appears macroscopically static but is microscopically dynamic: division and death rates exactly cancel at MIC but each is remarkably high, reaching 60% of the antibiotic-free division rate. A stochastic model of cells as collections of minimal replicating units we term ‘widgets’ reproduces both steady-state and transient features of our experiments. Sub-cellular fluctuations of widget numbers stochastically drive each new daughter cell to one of two alternate fates, division or death. First-order division or death rates emerge as eigenvalues of a stationary Markov process, and can be expressed in terms of the widget’s molecular properties. High division and death rates at MIC arise due to low mean and high relative fluctuations of widget number. Isolating cells at the threshold of irreversible death might allow molecular characterization of this minimal replication unit.

  3. Up-regulation of Kir2.1 by ER stress facilitates cell death of brain capillary endothelial cells

    International Nuclear Information System (INIS)

    Kito, Hiroaki; Yamazaki, Daiju; Ohya, Susumu; Yamamura, Hisao; Asai, Kiyofumi; Imaizumi, Yuji

    2011-01-01

    Highlights: → We found that application of endoplasmic reticulum (ER) stress with tunicamycin to brain capillary endothelial cells (BCECs) induced cell death. → The ER stress facilitated the expression of inward rectifier K + channel (K ir 2.1) and induced sustained membrane hyperpolarization. → The membrane hyperpolarization induced sustained Ca 2+ entry through voltage-independent nonspecific cation channels and consequently facilitated cell death. → The K ir 2.1 up-regulation by ER stress is, at least in part, responsible for cell death of BCECs under pathological conditions. -- Abstract: Brain capillary endothelial cells (BCECs) form blood brain barrier (BBB) to maintain brain homeostasis. Cell turnover of BCECs by the balance of cell proliferation and cell death is critical for maintaining the integrity of BBB. Here we found that stimuli with tunicamycin, endoplasmic reticulum (ER) stress inducer, up-regulated inward rectifier K + channel (K ir 2.1) and facilitated cell death in t-BBEC117, a cell line derived from bovine BCECs. The activation of K ir channels contributed to the establishment of deeply negative resting membrane potential in t-BBEC117. The deep resting membrane potential increased the resting intracellular Ca 2+ concentration due to Ca 2+ influx through non-selective cation channels and thereby partly but significantly regulated cell death in t-BBEC117. The present results suggest that the up-regulation of K ir 2.1 is, at least in part, responsible for cell death/cell turnover of BCECs induced by a variety of cellular stresses, particularly ER stress, under pathological conditions.

  4. Silicon does not mitigate cell death in cultured tobacco BY-2 cells subjected to salinity without ethylene emission.

    Science.gov (United States)

    Liang, Xiaolei; Wang, Huahua; Hu, Yanfeng; Mao, Lina; Sun, Lili; Dong, Tian; Nan, Wenbin; Bi, Yurong

    2015-02-01

    Silicon induces cell death when ethylene is suppressed in cultured tobacco BY-2 cells. There is a crosstalk between Si and ethylene signaling. Silicon (Si) is beneficial for plant growth. It alleviates both biotic and abiotic stresses in plants. How Si works in plants is still mysterious. This study investigates the mechanism of Si-induced cell death in tobacco BY-2 cell cultures when ethylene is suppressed. Results showed that K2SiO3 alleviated the damage of NaCl stress. Si treatment rapidly increased ethylene emission and the expression of ethylene biosynthesis genes. Treatments with Si + Ag and Si + aminooxyacetic acid (AOA, ethylene biosynthesis inhibitor) reduced the cell growth and increased cell damage. The treatment with Si + Ag induced hydrogen peroxide (H2O2) generation and ultimately cell death. Some nucleus of BY-2 cells treated with Si + Ag appeared TUNEL positive. The inhibition of H2O2 and nitric oxide (NO) production reduced the cell death rate induced by Si + Ag treatment. Si eliminated the up-regulation of alternative pathway by Ag. These data suggest that ethylene plays an important role in Si function in plants. Without ethylene, Si not only failed to enhance plant resistance, but also elevated H2O2 generation and further induced cell death in tobacco BY-2 cells.

  5. Yessotoxin as a Tool to Study Induction of Multiple Cell Death Pathways

    Directory of Open Access Journals (Sweden)

    Mónica Suárez Korsnes

    2012-07-01

    Full Text Available This work proposes to use the marine algal toxin yessotoxin (YTX to establish reference model experiments to explore medically valuable effects from induction of multiple cell death pathways. YTX is one of few toxins reported to make such induction. It is a small molecule compound which at low concentrations can induce apoptosis in primary cultures, many types of cells and cell lines. It can also induce a non-apoptotic form of programmed cell death in BC3H1 myoblast cell lines. The present contribution reviews arguments that this type of induction may have principal interest outside this particular example. One principal effect of medical interest may be that cancer cells will not so easily adapt to the synergistic effects from induction of more than one death pathway as compared to induction of only apoptosis.

  6. Hepatic leukemia factor promotes resistance to cell death: Implications for therapeutics and chronotherapy

    International Nuclear Information System (INIS)

    Waters, Katrina M.; Sontag, Ryan L.; Weber, Thomas J.

    2013-01-01

    Physiological variation related to circadian rhythms and aberrant gene expression patterns are believed to modulate therapeutic efficacy, but the precise molecular determinants remain unclear. Here we examine the regulation of cell death by hepatic leukemia factor (HLF), which is an output regulator of circadian rhythms and is aberrantly expressed in human cancers, using an ectopic expression strategy in JB6 mouse epidermal cells and human keratinocytes. Ectopic HLF expression inhibited cell death in both JB6 cells and human keratinocytes, as induced by serum-starvation, tumor necrosis factor alpha and ionizing radiation. Microarray analysis indicates that HLF regulates a complex multi-gene transcriptional program encompassing upregulation of anti-apoptotic genes, downregulation of pro-apoptotic genes, and many additional changes that are consistent with an anti-death program. Collectively, our results demonstrate that ectopic expression of HLF, an established transcription factor that cycles with circadian rhythms, can recapitulate many features associated with circadian-dependent physiological variation. - Highlights: ► Circadian-dependent physiological variation impacts therapeutic efficacy. ► Hepatic leukemia factor inhibits cell death and is a candidate circadian factor. ► Hepatic leukemia factor anti-death program is conserved in murine and human cells. ► Transcriptomics indicates the anti-death program results from a systems response

  7. Evolution of mitochondrial cell death pathway: Proapoptotic role of HtrA2/Omi in Drosophila

    International Nuclear Information System (INIS)

    Igaki, Tatsushi; Suzuki, Yasuyuki; Tokushige, Naoko; Aonuma, Hiroka; Takahashi, Ryosuke; Miura, Masayuki

    2007-01-01

    Despite the essential role of mitochondria in a variety of mammalian cell death processes, the involvement of mitochondrial pathway in Drosophila cell death has remained unclear. To address this, we cloned and characterized DmHtrA2, a Drosophila homolog of a mitochondrial serine protease HtrA2/Omi. We show that DmHtrA2 normally resides in mitochondria and is up-regulated by UV-irradiation. Upon receipt of apoptotic stimuli, DmHtrA2 is translocated to extramitochondrial compartment; however, unlike its mammalian counterpart, the extramitochondrial DmHtrA2 does not diffuse throughout the cytosol but stays near the mitochondria. RNAi-mediated knock-down of DmHtrA2 in larvae or adult flies results in a resistance to stress stimuli. DmHtrA2 specifically cleaves Drosophila inhibitor-of-apoptosis protein 1 (DIAP1), a cellular caspase inhibitor, and induces cell death both in vitro and in vivo as potent as other fly cell death proteins. Our observations suggest that DmHtrA2 promotes cell death through a cleavage of DIAP1 in the vicinity of mitochondria, which may represent a prototype of mitochondrial cell death pathway in evolution

  8. Hepatic leukemia factor promotes resistance to cell death: Implications for therapeutics and chronotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Waters, Katrina M. [Computational Biology and Bioinformatics, Pacific Northwest National Laboratory, Richland, WA 99354 (United States); Sontag, Ryan L. [Systems Toxicology Groups, Pacific Northwest National Laboratory, Richland, WA 99354 (United States); Weber, Thomas J., E-mail: Thomas.Weber@pnl.gov [Systems Toxicology Groups, Pacific Northwest National Laboratory, Richland, WA 99354 (United States)

    2013-04-15

    Physiological variation related to circadian rhythms and aberrant gene expression patterns are believed to modulate therapeutic efficacy, but the precise molecular determinants remain unclear. Here we examine the regulation of cell death by hepatic leukemia factor (HLF), which is an output regulator of circadian rhythms and is aberrantly expressed in human cancers, using an ectopic expression strategy in JB6 mouse epidermal cells and human keratinocytes. Ectopic HLF expression inhibited cell death in both JB6 cells and human keratinocytes, as induced by serum-starvation, tumor necrosis factor alpha and ionizing radiation. Microarray analysis indicates that HLF regulates a complex multi-gene transcriptional program encompassing upregulation of anti-apoptotic genes, downregulation of pro-apoptotic genes, and many additional changes that are consistent with an anti-death program. Collectively, our results demonstrate that ectopic expression of HLF, an established transcription factor that cycles with circadian rhythms, can recapitulate many features associated with circadian-dependent physiological variation. - Highlights: ► Circadian-dependent physiological variation impacts therapeutic efficacy. ► Hepatic leukemia factor inhibits cell death and is a candidate circadian factor. ► Hepatic leukemia factor anti-death program is conserved in murine and human cells. ► Transcriptomics indicates the anti-death program results from a systems response.

  9. [From dualism to multiplicity: seeing BCL-2 family proteins and cell death with new eyes].

    Science.gov (United States)

    Aouacheria, Abdel

    2015-01-01

    The concept of cell death has many links to the concept of death itself, defined as the opposite of life. Achievements obtained through research on apoptosis have apparently allowed us to transcend this Manichean view. Death is no longer outside, but rather inside living systems, as a constitutive force at work within the living matter. Whereas the death of cells can be positive and breed "creation" (e.g. during morphogenesis), its dysregulation can also cause or contribute to fatal diseases including cancer. It is tempting to apply this biological discourse to illuminate the relations between life and death, taken in general terms, but does this generalization actually hold? Is this discourse not essentially a metaphor? If cell death is considered as a vital aspect of various biological processes, then are we not faced with some vitalistic conception of death? Are there one or more meanings to the word "death"? Does the power to self-destruct act in opposition to other key features of living entities, or rather in juxtaposition to them? In this article, we first describe how the field of cell death has been developed on the basis of perceived and built dichotomies, mirroring the original opposition between life and death. We detail the limitations of the current paradigm of apoptosis regulation by BCL-2 family proteins, which nicely illustrate the problem of binary thinking in biology. Last, we try to show a way out of this dualistic matrix, by drawing on the notions of multiplicity, complexity, diversity, evolution and contingency. © Société de Biologie, 2016.

  10. PCM1 Depletion Inhibits Glioblastoma Cell Ciliogenesis and Increases Cell Death and Sensitivity to Temozolomide

    Directory of Open Access Journals (Sweden)

    Lan B. Hoang-Minh

    2016-10-01

    Full Text Available A better understanding of the molecules implicated in the growth and survival of glioblastoma (GBM cells and their response to temozolomide (TMZ, the standard-of-care chemotherapeutic agent, is necessary for the development of new therapies that would improve the outcome of current GBM treatments. In this study, we characterize the role of pericentriolar material 1 (PCM1, a component of centriolar satellites surrounding centrosomes, in GBM cell proliferation and sensitivity to genotoxic agents such as TMZ. We show that PCM1 is expressed around centrioles and ciliary basal bodies in patient GBM biopsies and derived cell lines and that its localization is dynamic throughout the cell cycle. To test whether PCM1 mediates GBM cell proliferation and/or response to TMZ, we used CRISPR/Cas9 genome editing to generate primary GBM cell lines depleted of PCM1. These PCM1-depleted cells displayed reduced AZI1 satellite protein localization and significantly decreased proliferation, which was attributable to increased apoptotic cell death. Furthermore, PCM1-depleted lines were more sensitive to TMZ toxicity than control lines. The increase in TMZ sensitivity may be partly due to the reduced ability of PCM1-depleted cells to form primary cilia, as depletion of KIF3A also ablated GBM cells' ciliogenesis and increased their sensitivity to TMZ while preserving PCM1 localization. In addition, the co-depletion of KIF3A and PCM1 did not have any additive effect on TMZ sensitivity. Together, our data suggest that PCM1 plays multiple roles in GBM pathogenesis and that associated pathways could be targeted to augment current or future anti-GBM therapies.

  11. Pro-inflammatory activated Kupffer cells by lipids induce hepatic NKT cells deficiency through activation-induced cell death.

    Directory of Open Access Journals (Sweden)

    Tongfang Tang

    Full Text Available BACKGROUND: Dietary lipids play an important role in the progression of non-alcoholic fatty liver disease (NAFLD through alternation of liver innate immune response. AIMS: The present study was to investigate the effect of lipid on Kupffer cells phenotype and function in vivo and in vitro. And further to investigate the impact of lipid on ability of Kupffer cell lipid antigen presentation to activate NKT cells. METHODS: Wild type male C57BL/6 mice were fed either normal or high-fat diet. Hepatic steatosis, Kupffer cell abundance, NKT cell number and cytokine gene expression were evaluated. Antigen presentation assay was performed with Kupffer cells treated with certain fatty acids in vitro and co-cultured with NKT cells. RESULTS: High-fat diet induced hepatosteatosis, significantly increased Kupffer cells and decreased hepatic NKT cells. Lipid treatment in vivo or in vitro induced increase of pro-inflammatory cytokines gene expression and toll-like receptor 4 (TLR4 expression in Kupffer cells. Kupffer cells expressed high levels of CD1d on cell surface and only presented exogenous lipid antigen to activate NKT cells. Ability of Kupffer cells to present antigen and activate NKT cells was enhanced after lipid treatment. In addition, pro-inflammatory activated Kupffer cells by lipid treatment induced hepatic NKT cells activation-induced apoptosis and necrosis. CONCLUSION: High-fat diet increase Kupffer cells number and induce their pro-inflammatory status. Pro-inflammatory activated Kupfffer cells by lipid promote hepatic NKT cell over-activation and cell death, which lead to further hepatic NKT cell deficiency in the development of NAFLD.

  12. Pro-inflammatory activated Kupffer cells by lipids induce hepatic NKT cells deficiency through activation-induced cell death.

    Science.gov (United States)

    Tang, Tongfang; Sui, Yongheng; Lian, Min; Li, Zhiping; Hua, Jing

    2013-01-01

    Dietary lipids play an important role in the progression of non-alcoholic fatty liver disease (NAFLD) through alternation of liver innate immune response. The present study was to investigate the effect of lipid on Kupffer cells phenotype and function in vivo and in vitro. And further to investigate the impact of lipid on ability of Kupffer cell lipid antigen presentation to activate NKT cells. Wild type male C57BL/6 mice were fed either normal or high-fat diet. Hepatic steatosis, Kupffer cell abundance, NKT cell number and cytokine gene expression were evaluated. Antigen presentation assay was performed with Kupffer cells treated with certain fatty acids in vitro and co-cultured with NKT cells. High-fat diet induced hepatosteatosis, significantly increased Kupffer cells and decreased hepatic NKT cells. Lipid treatment in vivo or in vitro induced increase of pro-inflammatory cytokines gene expression and toll-like receptor 4 (TLR4) expression in Kupffer cells. Kupffer cells expressed high levels of CD1d on cell surface and only presented exogenous lipid antigen to activate NKT cells. Ability of Kupffer cells to present antigen and activate NKT cells was enhanced after lipid treatment. In addition, pro-inflammatory activated Kupffer cells by lipid treatment induced hepatic NKT cells activation-induced apoptosis and necrosis. High-fat diet increase Kupffer cells number and induce their pro-inflammatory status. Pro-inflammatory activated Kupfffer cells by lipid promote hepatic NKT cell over-activation and cell death, which lead to further hepatic NKT cell deficiency in the development of NAFLD.

  13. Role of mitochondria-associated hexokinase II in cancer cell death induced by 3-Bromopyruvate

    Science.gov (United States)

    Chen, Zhao; Zhang, Hui; Lu, Weiqin; Huang, Peng

    2009-01-01

    Summary It has long been observed that cancer cells rely more on glycolysis to generate ATP and actively use certain glycolytic metabolic intermediates for biosynthesis. Hexokinase II (HKII) is a key glycolytic enzyme that plays a role in the regulation of the mitochondria-initiated apoptotic cell death. As a potent inhibitor of hexokinase, 3-bromopyruvate (3-BrPA) is known to inhibit cancer cell energy metabolism and trigger cell death, supposedly through depletion of cellular ATP. The current study showed that 3-BrPA caused a covalent modification of HKII protein and directly triggered its dissociation from mitochondria, leading to a specific release of apoptosis-inducing factor (AIF) from the mitochondria to cytosol and eventual cell death. Co-immunoprecipitation revealed a physical interaction between HKII and AIF. Using a competitive peptide of HKII, we showed that the dissociation of hexokinase II from mitochondria alone could cause apoptotic cell death, especially in the mitochondria-deficient ρ0 cells that highly express HKII. Interestingly, the dissociation of HKII itself did no directly affect the mitochondrial membrane potential, ROS generation, and oxidative phosphorylation. Our study suggests that the physical association between HKII and AIF is important for the normal localization of AIF in the mitochondria, and disruption of this protein complex by 3-BrPA leads to their release from the mitochondria and eventual cell death. PMID:19285479

  14. Oxidative stress, mitochondrial permeability transition, and cell death in Cu-exposed trout hepatocytes

    International Nuclear Information System (INIS)

    Krumschnabel, Gerhard; Manzl, Claudia; Berger, Christian; Hofer, Bettina

    2005-01-01

    We have previously shown that, in trout hepatocytes, exposure to a high dose of copper (Cu) leads to disruption of Ca 2+ homeostasis and elevated formation of reactive oxygen species (ROS), with the latter ultimately causing cell death. In the present study, we aimed at identifying, using a lower Cu concentration, the role of mitochondria in this scenario, the potential involvement of the mitochondrial permeability transition (MPT), and the mode of cell death induced by the metal. Incubation with 10 μM Cu resulted in a strong stimulation of ROS formation, and after 2 h of exposure a significant increase of both apoptotic and necrotic cells was seen. Co-incubation of Cu-treated hepatocytes with the iron-chelator deferoxamine significantly inhibited ROS production and completely prevented cell death. The origin of the radicals generated was at least partly mitochondrial, as visualized by confocal laser scanning microscopy. Furthermore, ROS production was diminished by inhibition of mitochondrial respiration, but since this also aggravated the elevation of intracellular Ca 2+ induced by Cu, it did not preserve cell viability. In a sub-population of cells, Cu induced a decrease of mitochondrial membrane potential and occurrence of the MPT. Cyclosporin A, which did not inhibit ROS formation, prevented the onset of the MPT and inhibited apoptotic, but not necrotic, cell death. Cu-induced apoptosis therefore appears to be dependent on induction of the MPT, but the prominent contribution of mitochondria to ROS generation also suggests an important role of mitochondria in necrotic cell death

  15. p53 dependent apoptotic cell death induces embryonic malformation in Carassius auratus under chronic hypoxia.

    Directory of Open Access Journals (Sweden)

    Paramita Banerjee Sawant

    Full Text Available Hypoxia is a global phenomenon affecting recruitment as well as the embryonic development of aquatic fauna. The present study depicts hypoxia induced disruption of the intrinsic pathway of programmed cell death (PCD, leading to embryonic malformation in the goldfish, Carrasius auratus. Constant hypoxia induced the early expression of pro-apoptotic/tumor suppressor p53 and concomitant expression of the cell death molecule, caspase-3, leading to high level of DNA damage and cell death in hypoxic embryos, as compared to normoxic ones. As a result, the former showed delayed 4 and 64 celled stages and a delay in appearance of epiboly stage. Expression of p53 efficiently switched off expression of the anti-apoptotic Bcl-2 during the initial 12 hours post fertilization (hpf and caused embryonic cell death. However, after 12 hours, simultaneous downregulation of p53 and Caspase-3 and exponential increase of Bcl-2, caused uncontrolled cell proliferation and prevented essential programmed cell death (PCD, ultimately resulting in significant (p<0.05 embryonic malformation up to 144 hpf. Evidences suggest that uncontrolled cell proliferation after 12 hpf may have been due to downregulation of p53 abundance, which in turn has an influence on upregulation of anti-apoptotic Bcl-2. Therefore, we have been able to show for the first time and propose that hypoxia induced downregulation of p53 beyond 12 hpf, disrupts PCD and leads to failure in normal differentiation, causing malformation in gold fish embryos.

  16. NETs: The missing link between cell death and systemic autoimmune diseases?

    Directory of Open Access Journals (Sweden)

    Felipe eAndrade

    2013-01-01

    Full Text Available For almost 20 years, apoptosis and secondary necrosis have been considered the major source of autoantigens and endogenous adjuvants in the pathogenic model of systemic autoimmune diseases. This focus is justified in part because initial evidence in systemic lupus erythematosus (SLE guided investigators toward the study of apoptosis, but also because other forms of cell death were unknown. To date, it is known that many other forms of cell death occur, and that they vary in their capacity to stimulate as well as inhibit the immune system. Among these, NETosis (an antimicrobial form of death in neutrophils in which nuclear material is extruded from the cell forming extracellular traps, is gaining major interest as a process that may trigger some of the immune features found in SLE, granulomatosis with polyangiitis (formerly Wegener’s granulomatosis and Felty’s syndrome. Although there have been volumes of very compelling studies published on the role of cell death in autoimmunity, no unifying theory has been adopted nor have any successful therapeutics been developed based on this important pathway. The recent inclusion of NETosis into the pathogenic model of autoimmune diseases certainly adds novel insights into this paradigm, but also reveals a previously unappreciated level of complexity and raises many new questions. This review discusses the role of cell death in systemic autoimmune diseases with a focus on apoptosis and NETosis, highlights the current short comings in our understanding of the vast complexity of cell death, and considers the potential shift in the cell death paradigm in autoimmunity. Understanding this complexity is critical in order to develop tools to clearly define the death pathways that are active in systemic autoimmune diseases, identify drivers of disease propagation, and develop novel therapeutics.

  17. Death receptor pathways mediate targeted and non-targeted effects of ionizing radiations in breast cancer cells

    International Nuclear Information System (INIS)

    Luce, A.; Courtin, A.; Levalois, C.; Altmeyer-Morel, S.; Chevillard, S.; Lebeau, J.; Romeo, P.H.

    2009-01-01

    Delayed cell death by mitotic catastrophe is a frequent mode of solid tumor cell death after γ-irradiation, a widely used treatment of cancer. Whereas the mechanisms that underlie the early γ-irradiation-induced cell death are well documented, those that drive the delayed cell death are largely unknown. Here we show that the Fas, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and tumor necrosis factor (TNF)-α death receptor pathways mediate the delayed cell death observed after γ-irradiation of breast cancer cells. Early after irradiation, we observe the increased expression of Fas, TRAIL-R and TNF-R that first sensitizes cells to apoptosis. Later, the increased expression of FasL, TRAIL and TNF-α permit the apoptosis engagement linked to mitotic catastrophe. Treatments with TNF-α, TRAIL or anti-Fas antibody, early after radiation exposure, induce apoptosis, whereas the neutralization of the three death receptors pathways impairs the delayed cell death. We also show for the first time that irradiated breast cancer cells excrete soluble forms of the three ligands that can induce the death of sensitive bystander cells. Overall, these results define the molecular basis of the delayed cell death of irradiated cancer cells and identify the death receptors pathways as crucial actors in apoptosis induced by targeted as well as non-targeted effects of ionizing radiation. (authors)

  18. Stress-induced cell death is mediated by ceramide synthesis in Neurospora crassa

    DEFF Research Database (Denmark)

    Plesofsky, Nora S; Levery, Steven B; Castle, Sherry A

    2008-01-01

    The combined stresses of moderate heat shock (45 degrees C) and analog-induced glucose deprivation constitute a lethal stress for Neurospora crassa. We found that this cell death requires fatty acid synthesis and the cofactor biotin. In the absence of the cofactor, the stressed cells are particul......The combined stresses of moderate heat shock (45 degrees C) and analog-induced glucose deprivation constitute a lethal stress for Neurospora crassa. We found that this cell death requires fatty acid synthesis and the cofactor biotin. In the absence of the cofactor, the stressed cells...

  19. Induction of morphological changes in death-induced cancer cells monitored by holographic microscopy.

    Science.gov (United States)

    El-Schich, Zahra; Mölder, Anna; Tassidis, Helena; Härkönen, Pirkko; Falck Miniotis, Maria; Gjörloff Wingren, Anette

    2015-03-01

    We are using the label-free technique of holographic microscopy to analyze cellular parameters including cell number, confluence, cellular volume and area directly in the cell culture environment. We show that death-induced cells can be distinguished from untreated counterparts by the use of holographic microscopy, and we demonstrate its capability for cell death assessment. Morphological analysis of two representative cell lines (L929 and DU145) was performed in the culture flasks without any prior cell detachment. The two cell lines were treated with the anti-tumour agent etoposide for 1-3days. Measurements by holographic microscopy showed significant differences in average cell number, confluence, volume and area when comparing etoposide-treated with untreated cells. The cell volume of the treated cell lines was initially increased at early time-points. By time, cells decreased in volume, especially when treated with high doses of etoposide. In conclusion, we have shown that holographic microscopy allows label-free and completely non-invasive morphological measurements of cell growth, viability and death. Future applications could include real-time monitoring of these holographic microscopy parameters in cells in response to clinically relevant compounds. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Diatom-derived polyunsaturated aldehydes activate cell death in human cancer cell lines but not normal cells.

    Directory of Open Access Journals (Sweden)

    Clementina Sansone

    Full Text Available Diatoms are an important class of unicellular algae that produce bioactive polyunsaturated aldehydes (PUAs that induce abortions or malformations in the offspring of invertebrates exposed to them during gestation. Here we compare the effects of the PUAs 2-trans,4-trans-decadienal (DD, 2-trans,4-trans-octadienal (OD and 2-trans,4-trans-heptadienal (HD on the adenocarcinoma cell lines lung A549 and colon COLO 205, and the normal lung/brunch epithelial BEAS-2B cell line. Using the viability MTT/Trypan blue assays, we show that PUAs have a toxic effect on both A549 and COLO 205 tumor cells but not BEAS-2B normal cells. DD was the strongest of the three PUAs tested, at all time-intervals considered, but HD was as strong as DD after 48 h. OD was the least active of the three PUAs. The effect of the three PUAs was somewhat stronger for A549 cells. We therefore studied the death signaling pathway activated in A549 showing that cells treated with DD activated Tumor Necrosis Factor Receptor 1 (TNFR1 and Fas Associated Death Domain (FADD leading to necroptosis via caspase-3 without activating the survival pathway Receptor-Interacting Protein (RIP. The TNFR1/FADD/caspase pathway was also observed with OD, but only after 48 h. This was the only PUA that activated RIP, consistent with the finding that OD causes less damage to the cell compared to DD and HD. In contrast, cells treated with HD activated the Fas/FADD/caspase pathway. This is the first report that PUAs activate an extrinsic apoptotic machinery in contrast to other anticancer drugs that promote an intrinsic death pathway, without affecting the viability of normal cells from the same tissue type. These findings have interesting implications also from the ecological viewpoint considering that HD is one of the most common PUAs produced by diatoms.

  1. Granzyme A Cleaves a Mitochondrial Complex I Protein to Initiate Caspase-Independent Cell Death

    Science.gov (United States)

    Martinvalet, Denis; Dykxhoorn, Derek M.; Ferrini, Roger; Lieberman, Judy

    2010-01-01

    SUMMARY The killer lymphocyte protease granzyme A (GzmA) triggers caspase-independent target cell death with morphological features of apoptosis. We previously showed that GzmA acts directly on mitochondria to generate reactive oxygen species (ROS) and disrupt the transmembrane potential (ΔΨm) but does not permeabilize the mitochondrial outer membrane. Mitochondrial damage is critical to GzmA-induced cell death since cells treated with superoxide scavengers are resistant to GzmA. Here we find that GzmA accesses the mitochondrial matrix to cleave the complex I protein NDUFS3, an iron-sulfur subunit of the NADH:ubiquinone oxidoreductase complex I, after Lys56 to interfere with NADH oxidation and generate superoxide anions. Target cells expressing a cleavage site mutant of NDUFS3 are resistant to GzmA-mediated cell death but remain sensitive to GzmB. PMID:18485875

  2. Rip3 knockdown rescues photoreceptor cell death in blind pde6c zebrafish.

    Science.gov (United States)

    Viringipurampeer, I A; Shan, X; Gregory-Evans, K; Zhang, J P; Mohammadi, Z; Gregory-Evans, C Y

    2014-05-01

    Achromatopsia is a progressive autosomal recessive retinal disease characterized by early loss of cone photoreceptors and later rod photoreceptor loss. In most cases, mutations have been identified in CNGA3, CNGB3, GNAT2, PDE6C or PDE6H genes. Owing to this genetic heterogeneity, mutation-independent therapeutic schemes aimed at preventing cone cell death are very attractive treatment strategies. In pde6c(w59) mutant zebrafish, cone photoreceptors expressed high levels of receptor-interacting protein kinase 1 (RIP1) and receptor-interacting protein kinase 3 (RIP3) kinases, key regulators of necroptotic cell death. In contrast, rod photoreceptor cells were alternatively immunopositive for caspase-3 indicating activation of caspase-dependent apoptosis in these cells. Morpholino gene knockdown of rip3 in pde6c(w59) embryos rescued the dying cone photoreceptors by inhibiting the formation of reactive oxygen species and by inhibiting second-order neuron remodelling in the inner retina. In rip3 morphant larvae, visual function was restored in the cones by upregulation of the rod phosphodiesterase genes (pde6a and pde6b), compensating for the lack of cone pde6c suggesting that cones are able to adapt to their local environment. Furthermore, we demonstrated through pharmacological inhibition of RIP1 and RIP3 activity that cone cell death was also delayed. Collectively, these results demonstrate that the underlying mechanism of cone cell death in the pde6c(w59) mutant retina is through necroptosis, whereas rod photoreceptor bystander death occurs through a caspase-dependent mechanism. This suggests that targeting the RIP kinase signalling pathway could be an effective therapeutic intervention in retinal degeneration patients. As bystander cell death is an important feature of many retinal diseases, combinatorial approaches targeting different cell death pathways may evolve as an important general principle in treatment.

  3. Growth and death of animal cells in bioreactors

    NARCIS (Netherlands)

    Martens, D.E.

    1996-01-01


    Animal-cell cultivation is becoming increasingly important especially for the area of hunian- health products. The products range from vaccines to therapeutic proteins and the cells themselves. The therapeutic application of proteins puts high demands upon their quality with respect to

  4. Ion channels involved in cell volume regulation: effects on migration, proliferation, and programmed cell death in non adherent EAT cells and adherent ELA cells.

    Science.gov (United States)

    Hoffmann, Else Kay

    2011-01-01

    This mini review outlines studies of cell volume regulation in two closely related mammalian cell lines: nonadherent Ehrlich ascites tumour cells (EATC) and adherent Ehrlich Lettre ascites (ELA) cells. Focus is on the regulatory volume decrease (RVD) that occurs after cell swelling, the volume regulatory ion channels involved, and the mechanisms (cellular signalling pathways) that regulate these channels. Finally, I shall also briefly review current investigations in these two cell lines that focuses on how changes in cell volume can regulate cell functions such as cell migration, proliferation, and programmed cell death. Copyright © 2011 S. Karger AG, Basel.

  5. Hyperthermia enhances radiosensitivity of colorectal cancer cells through ROS inducing autophagic cell death.

    Science.gov (United States)

    Ba, Ming-Chen; Long, Hui; Wang, Shuai; Wu, Yin-Bing; Zhang, Bo-Huo; Yan, Zhao-Fei; Yu, Fei-Hong; Cui, Shu-Zhong

    2018-04-01

    Hyperthermia (HT) enhances the anti-cancer effects of radiotherapy (RT), but the precise biochemical mechanisms involved are unclear. This study was aim to investigate if mild HT sensitizes colorectal cancer cells to RT through reactive oxygen species (ROS)-inducing autophagic cell death in a mice model of HCT116 human colorectal cancer. HCT116 mice model were randomly divided into five groups: mock group, hyperthermia group (HT), radiotherapy group (RT), HT + RT group, and HT + RT +N-acetyl L-cysteine (NAC) group (HT + CT + NAC). After four weeks of treatment, cancer growth inhibition, rate and mitochondrial membrane potential were measured with MTT and JC-1 assays, respectively, while ROS were estimated fluorimetrically. The relationship of these parameters to expressions of autophagy-related genes Beclin1, LC3B, and mTOR was analyzed. Gene expression was measured by Real-Time polymerase chain reaction (RT-PCR). There were significant increases in ROS levels and mitochondrial membrane potential in the HT + RT group. ROS levels in the HT + RT group increased more significantly than in any other group. In contrast, ROS levels in the HT + RT + NAC group were significantly decreased relative to the HT + RT group. The number of autophagic bodies in HT + RT group was higher than that of mock group. There were significant increases in the expression of Beclin1 and LC3B genes, while mTOR expression was significantly decreased in the HT + CT group. Treatment with NAC reversed the pattern of these changes. These results indicate that HT enhances the radiosensitivity of colorectal cancer cells to RT through ROS inducing autophagic cell death. © 2017 Wiley Periodicals, Inc.

  6. A critical role for ethylene in hydrogen peroxide release during programmed cell death in tomato suspension cells

    NARCIS (Netherlands)

    Jong, de A.J.; Yakimova, E.T.; Kapchina, V.M.; Woltering, E.J.

    2002-01-01

    Camptothecin, a topo isomerase-I inhibitor used in cancer therapy, induces apoptosis in animal cells. In tomato (Lycopersicon esculentum Mill.) suspension cells, camptothecin induces cell death that is accompanied by the characteristic nuclear morphological changes such as chromatin condensation and

  7. The antimicrobial peptide nisin Z induces selective toxicity and apoptotic cell death in cultured melanoma cells.

    Science.gov (United States)

    Lewies, Angélique; Wentzel, Johannes Frederik; Miller, Hayley Christy; Du Plessis, Lissinda Hester

    2018-01-01

    Reprogramming of cellular metabolism is now considered one of the hallmarks of cancer. Most malignant cells present with altered energy metabolism which is associated with elevated reactive oxygen species (ROS) generation. This is also evident for melanoma, the leading cause of skin cancer related deaths. Altered mechanisms affecting mitochondrial bioenergetics pose attractive targets for novel anticancer therapies. Antimicrobial peptides have been shown to exhibit selective anticancer activities. In this study, the anti-melanoma potential of the antimicrobial peptide, nisin Z, was evaluated in vitro. Nisin Z was shown to induce selective toxicity in melanoma cells compared to non-malignant keratinocytes. Furthermore, nisin Z was shown to negatively affect the energy metabolism (glycolysis and mitochondrial respiration) of melanoma cells, increase reactive oxygen species generation and cause apoptosis. Results also indicate that nisin Z can decrease the invasion and proliferation of melanoma cells demonstrating its potential use against metastasis associated with melanoma. As nisin Z seems to place a considerable extra burden on the energy metabolism of melanoma cells, combination therapies with known anti-melanoma agents may be effective treatment options. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  8. Cell-permeable gomesin peptide promotes cell death by intracellular Ca(2+) overload.

    Science.gov (United States)

    Paredes-Gamero, Edgar J; Casaes-Rodrigues, Rafael L; Moura, Gioconda E D D; Domingues, Tatiana M; Buri, Marcus V; Ferreira, Victor H C; Trindade, Edvaldo S; Moreno-Ortega, Ana J; Cano-Abad, María F; Nader, Helena B; Ferreira, Alice T; Miranda, Antonio; Justo, Giselle Z; Tersariol, Ivarne L S

    2012-09-04

    In recent years, the antitumoral activity of antimicrobial peptides (AMPs) has been the goal of many research studies. Among AMPs, gomesin (Gm) displays antitumor activity by unknown mechanisms. Herein, we studied the cytotoxicity of Gm in the Chinese hamster ovary (CHO) cell line. Furthermore, we investigated the temporal ordering of organelle changes and the dynamics of Ca(2+) signaling during Gm-induced cell death. The results indicated that Gm binds to the plasma membrane and rapidly translocates into the cytoplasm. Moreover, 20 μM Gm increases the cytosolic Ca(2+) and induces membrane permeabilization after 30 min of treatment. Direct Ca(2+) measurements in CHO cells transfected with the genetically encoded D1-cameleon to the endoplasmic reticulum (ER) revealed that Gm induces ER Ca(2+) depletion, which in turn resulted in oscillatory mitochondrial Ca(2+) signal, as measured in cells expressing the genetically encoded probe to the mitochondrial matrix (mit)Pericam. This leads to mitochondria disruption, loss of mitochondrial membrane potential and increased reactive oxygen species prior to membrane permeabilization. Gm-induced membrane permeabilization by a Ca(2+)-dependent pathway involving Gm translocation into the cell, ER Ca(2+) depletion and disruption, mitochondrial Ca(2+) overload and oxidative stress.

  9. The intersection between DNA damage response and cell death pathways.

    Science.gov (United States)

    Nowsheen, S; Yang, E S

    2012-10-01

    Apoptosis is a finely regulated process that serves to determine the fate of cells in response to various stresses. One such stress is DNA damage, which not only can signal repair processes but is also intimately involved in regulating cell fate. In this review we examine the relationship between the DNA damage/repair response in cell survival and apoptosis following insults to the DNA. Elucidating these pathways and the crosstalk between them is of great importance, as they eventually contribute to the etiology of human disease such as cancer and may play key roles in determining therapeutic response. This article is part of a Special Issue entitled "Apoptosis: Four Decades Later".

  10. Nitric oxide production is not required for dihydrosphingosine-induced cell death in tobacco BY-2 cells.

    Science.gov (United States)

    Da Silva, Daniel; Lachaud, Christophe; Cotelle, Valérie; Brière, Christian; Grat, Sabine; Mazars, Christian; Thuleau, Patrice

    2011-05-01

    Sphinganine or dihydrosphingosine (d18:0, DHS), one of the most abundant free sphingoid Long Chain Base (LCB) in plants, is known to induce a calcium dependent programmed cell death (PCD) in tobacco BY-2 cells. In addition, we have recently shown that DHS triggers a production of H2O2, via the activation of NADPH oxidase(s). However, this production of H2O2 is not correlated with the DHS-induced cell death but would rather be associated with basal cell defense mechanisms. In the present study, we extend our current knowledge of the DHS signaling pathway, by demonstrating that DHS also promotes a production of nitric oxide (NO) in tobacco BY-2 cells. As for H2O2, this NO production is not necessary for cell death induction. 

  11. Exosomal lipids impact notch signaling and induce death of human pancreatic tumoral SOJ-6 cells.

    Directory of Open Access Journals (Sweden)

    Sadia Beloribi

    Full Text Available Exosomes are of increasing interest as alternative mode of cell-to-cell communication. We previously reported that exosomes secreted by human SOJ-6 pancreatic tumor cells induce (glycoprotein ligand-independent cell death and inhibit Notch-1 pathway, this latter being particularly active during carcinogenesis and in cancer stem cells. Therefore, we asked whether exosomal lipids were key-elements for cell death and hypothesized that cholesterol-rich membrane microdomains were privileged sites of exosome interactions with tumor cells. To address these questions and based on the lipid composition of exosomes from SOJ-6 cells (Ristorcelli et al. (2008 FASEB J. 22; 3358-3369 enriched in cholesterol and sphingomyelin (lipids forming liquid-ordered phase, Lo and depleted in phospholipids (lipids forming liquid-disordered phase, Ld, we designed Synthetic Exosome-Like Nanoparticles (SELN with ratios Lo/Ld from 3.0 to 6.0 framing that of SOJ-6 cell exosomes. SELN decreased tumor cell survival, the higher the Lo/Ld ratio, the lower the cell survival. This decreased survival was due to activation of cell death with inhibition of Notch pathway. FRET analyses indicated fusions/exchanges of SELN with cell membranes. Fluorescent SELN co-localized with the ganglioside GM1 then with Rab5A, markers of lipid microdomains and of early endosomes, respectively. These interactions occurred at lipid microdomains of plasma and/or endosome membranes where the Notch-1 pathway matures. We thus demonstrated a major role for lipids in interactions between SELN and tumor cells, and in the ensued cell death. To our knowledge this is the first report on such effects of lipidic nanoparticles on tumor cell behavior. This may have implications in tumor progression.

  12. Ebselen Induced C6 Glioma Cell Death in Oxygen and Glucose Deprivation

    OpenAIRE

    Shi, Honglian; Liu, Shimin; Miyake, Minoru; Liu, Ke Jian

    2006-01-01

    Studies have shown that ebselen is an anti-inflammatory and antioxidative agent. Its protective effect has been investigated in oxidative stress related diseases such as cerebral ischemia in recent years. However, experimental evidence also shows that ebselen causes cell death in several different cell types. Whether ebselen will have beneficial or detrimental effect on cells under ischemic condition is not known. Herein, we studied the effect of ebselen on C6 glioma cell under oxygen and glu...

  13. Membrane phospholipids and radiation-induced death of mammalian cells

    International Nuclear Information System (INIS)

    Wolters, H.

    1987-01-01

    Radiation-induced cell killing is generally believed to be a consequence of residual DNA damage or damage that is mis-repaired. However, besides this DNA damage, damage to other molecules or structures of the cell may be involved in the killing. Especially membranes have been suggested as a determinant in cellular radiosensitivity. In this thesis experiments are described, dealing with the possible involvement of membranes in radiation-induced killing of mammalian cells. A general treatise of membrane structure is followed by information concerning deleterious effects of radiation on membranes. Consequences of damage to structure and function of membranes are reviewed. Thereafter evidence relating to the possible involvement of membranes in radiation-induced cell killing is presented. (Auth.)

  14. A CRISPR-Based Screen Identifies Genes Essential for West-Nile-Virus-Induced Cell Death.

    Science.gov (United States)

    Ma, Hongming; Dang, Ying; Wu, Yonggan; Jia, Gengxiang; Anaya, Edgar; Zhang, Junli; Abraham, Sojan; Choi, Jang-Gi; Shi, Guojun; Qi, Ling; Manjunath, N; Wu, Haoquan

    2015-07-28

    West Nile virus (WNV) causes an acute neurological infection attended by massive neuronal cell death. However, the mechanism(s) behind the virus-induced cell death is poorly understood. Using a library containing 77,406 sgRNAs targeting 20,121 genes, we performed a genome-wide screen followed by a second screen with a sub-library. Among the genes identified, seven genes, EMC2, EMC3, SEL1L, DERL2, UBE2G2, UBE2J1, and HRD1, stood out as having the strongest phenotype, whose knockout conferred strong protection against WNV-induced cell death with two different WNV strains and in three cell lines. Interestingly, knockout of these genes did not block WNV replication. Thus, these appear to be essential genes that link WNV replication to downstream cell death pathway(s). In addition, the fact that all of these genes belong to the ER-associated protein degradation (ERAD) pathway suggests that this might be the primary driver of WNV-induced cell death. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  15. Cytotoxic T lymphocyte-mediated cytolysis: an example of programmed cell death in the immune system

    International Nuclear Information System (INIS)

    Duke, R.C.

    1985-01-01

    Target cells are programmed to die following interaction with cytotoxic T lymphocytes (CTLs). Within minutes of exposure to CTL the target cell's nuclear DNA is fragmented. Target cell lysis, as measured by 51 Cr release, occurs about 60 minutes after induction of DNA fragmentation. DNA fragmentation results from the action of an endonuclease which cleaves DNA in the linker region between nucleosomes. The origin of this nuclease, whether transferred to the target by the CTL or endogenous to the target cell, has not been resolved. DNA fragmentation occurs only when appropriately sensitized CTL are used and is not merely the result of cell death because killing of target cells by extreme deviation from homeostasis, by interruption of energy production, or by lysis with antibody and complement does not induce DNA cleavage. When Triton X-100 is added to target cells which have interacted with CTL, the DNA fragments do not remain in association with the nucleus. This observation suggests that breakdown of overall nuclear structure is induced concomitantly with DNA fragmentation. Morphologically, disruption of nuclear structure and DNA fragmentation are observed as widespread chromatin condensation (apoptosis). Apoptosis is observed in metabolically active target cells and is not a consequence of cell death. A cell whose DNA is extensively fragmented is condemmed to die. Induction of oligonucleosome-sized DNA is also an early event in glucocorticoid-induced thymocyte death and death of T cells upon removal of growth factor. Several similarities exist between these systems and CTL-mediated cytolysis suggesting a final common biochemical pathway for all three types of cell death

  16. Increased anion channel activity is an unavoidable event in ozone-induced programmed cell death.

    Directory of Open Access Journals (Sweden)

    Takashi Kadono

    Full Text Available BACKGROUND: Ozone is a major secondary air pollutant often reaching high concentrations in urban areas under strong daylight, high temperature and stagnant high-pressure systems. Ozone in the troposphere is a pollutant that is harmful to the plant. PRINCIPAL FINDINGS: By exposing cells to a strong pulse of ozonized air, an acute cell death was observed in suspension cells of Arabidopsis thaliana used as a model. We demonstrated that O(3 treatment induced the activation of a plasma membrane anion channel that is an early prerequisite of O(3-induced cell death in A. thaliana. Our data further suggest interplay of anion channel activation with well known plant responses to O(3, Ca(2+ influx and NADPH-oxidase generated reactive oxygen species (ROS in mediating the oxidative cell death. This interplay might be fuelled by several mechanisms in addition to the direct ROS generation by O(3; namely, H(2O(2 generation by salicylic and abscisic acids. Anion channel activation was also shown to promote the accumulation of transcripts encoding vacuolar processing enzymes, a family of proteases previously reported to contribute to the disruption of vacuole integrity observed during programmed cell death. SIGNIFICANCE: Collectively, our data indicate that anion efflux is an early key component of morphological and biochemical events leading to O(3-induced programmed cell death. Because ion channels and more specifically anion channels assume a crucial position in cells, an understanding about the underlying role(s for ion channels in the signalling pathway leading to programmed cell death is a subject that warrants future investigation.

  17. Trypanosoma cruzi response to sterol biosynthesis inhibitors: morphophysiological alterations leading to cell death.

    Directory of Open Access Journals (Sweden)

    Rafael Luis Kessler

    Full Text Available The protozoan parasite Trypanosoma cruzi displays similarities to fungi in terms of its sterol lipid biosynthesis, as ergosterol and other 24-alkylated sterols are its principal endogenous sterols. The sterol pathway is thus a potential drug target for the treatment of Chagas disease. We describe here a comparative study of the growth inhibition, ultrastructural and physiological changes leading to the death of T. cruzi cells following treatment with the sterol biosynthesis inhibitors (SBIs ketoconazole and lovastatin. We first calculated the drug concentration inhibiting epimastigote growth by 50% (EC(50/72 h or killing all cells within 24 hours (EC(100/24 h. Incubation with inhibitors at the EC(50/72 h resulted in interesting morphological changes: intense proliferation of the inner mitochondrial membrane, which was corroborated by flow cytometry and confocal microscopy of the parasites stained with rhodamine 123, and strong swelling of the reservosomes, which was confirmed by acridine orange staining. These changes to the mitochondria and reservosomes may reflect the involvement of these organelles in ergosterol biosynthesis or the progressive autophagic process culminating in cell lysis after 6 to 7 days of treatment with SBIs at the EC(50/72 h. By contrast, treatment with SBIs at the EC(100/24 h resulted in rapid cell death with a necrotic phenotype: time-dependent cytosolic calcium overload, mitochondrial depolarization and reservosome membrane permeabilization (RMP, culminating in cell lysis after a few hours of drug exposure. We provide the first demonstration that RMP constitutes the "point of no return" in the cell death cascade, and propose a model for the necrotic cell death of T. cruzi. Thus, SBIs trigger cell death by different mechanisms, depending on the dose used, in T. cruzi. These findings shed new light on ergosterol biosynthesis and the mechanisms of programmed cell death in this ancient protozoan parasite.

  18. Protective Effects of Mouse Bone Marrow Mesenchymal Stem Cell Soup on Staurosporine Induced Cell Death in PC12 and U87 Cell Lines

    Directory of Open Access Journals (Sweden)

    Hossein Zhaleh

    2016-11-01

    Full Text Available Mouse bone marrow mesenchymal stem cells (mBMSCs soup is promising tool for the treatment of neurodegenerative diseases. mBMSCs soup is easily obtained and is capable of transplantation without rejection. We investigated the effects of mBMSC soup on staurosporine-induced cell death in PC12 and U87 cells lines. The percentage of cell viability, cell death, NO concentration, total neurite length (TNL and fraction of cell differentiation (f% were assessed. Viability assay showed that mBM soup (24 and 48h in time dependent were increased cell viability (p<0.05 and also cell death assay showed that cell death in time dependent were decreased, respectively (p<0.05. TNL and fraction of cell differentiation significantly were increased compared with treatment1 (p<0.05. Our data showed that mBM Soup protects cells, increases cell viability, suppresses cell death and improvement the neurite elongation. We concluded that Mouse bone marrow mesenchymal stem cell soup plays an important protective role in staurosporine-induced cell death in PC12 and U87 cell lines.

  19. Immunogenic Cell Death Induced by Ginsenoside Rg3: Significance in Dendritic Cell-based Anti-tumor Immunotherapy.

    Science.gov (United States)

    Son, Keum-Joo; Choi, Ki Ryung; Lee, Seog Jae; Lee, Hyunah

    2016-02-01

    Cancer is one of the leading causes of morbidity and mortality worldwide; therefore there is a need to discover new therapeutic modules with improved efficacy and safety. Immune-(cell) therapy is a promising therapeutic strategy for the treatment of intractable cancers. The effectiveness of certain chemotherapeutics in inducing immunogenic tumor cell death thus promoting cancer eradication has been reported. Ginsenoside Rg3 is a ginseng saponin that has antitumor and immunomodulatory activity. In this study, we treated tumor cells with Rg3 to verify the significance of inducing immunogenic tumor cell death in antitumor therapy, especially in DC-based immunotherapy. Rg3 killed the both immunogenic (B16F10 melanoma cells) and non-immunogenic (LLC: Lewis Lung Carcinoma cells) tumor cells by inducing apoptosis. Surface expression of immunogenic death markers including calreticulin and heat shock proteins and the transcription of relevant genes were increased in the Rg3-dying tumor. Increased calreticulin expression was directly related to the uptake of dying tumor cells by dendritic cells (DCs): the proportion of CRT(+) CD11c(+) cells was increased in the Rg3-treated group. Interestingly, tumor cells dying by immunogenic cell death secreted IFN-γ, an effector molecule for antitumor activity in T cells. Along with the Rg3-induced suppression of pro-angiogenic (TNF-α) and immunosuppressive cytokine (TGF-β) secretion, IFN-γ production from the Rg3-treated tumor cells may also indicate Rg3 as an effective anticancer immunotherapeutic strategy. The data clearly suggests that Rg3-induced immunogenic tumor cell death due its cytotoxic effect and its ability to induce DC function. This indicates that Rg3 may be an effective immunotherapeutic strategy.

  20. Mitochondria-targeted vitamin E analogs inhibit breast cancer cell energy metabolism and promote cell death

    International Nuclear Information System (INIS)

    Cheng, Gang; Zielonka, Jacek; McAllister, Donna M; Mackinnon, A Craig Jr; Joseph, Joy; Dwinell, Michael B; Kalyanaraman, Balaraman

    2013-01-01

    Recent research has revealed that targeting mitochondrial bioenergetic metabolism is a promising chemotherapeutic strategy. Key to successful implementation of this chemotherapeutic strategy is the use of new and improved mitochondria-targeted cationic agents that selectively inhibit energy metabolism in breast cancer cells, while exerting little or no long-term cytotoxic effect in normal cells. In this study, we investigated the cytotoxicity and alterations in bioenergetic metabolism induced by mitochondria-targeted vitamin E analog (Mito-chromanol, Mito-ChM) and its acetylated ester analog (Mito-ChMAc). Assays of cell death, colony formation, mitochondrial bioenergetic function, intracellular ATP levels, intracellular and tissue concentrations of tested compounds, and in vivo tumor growth were performed. Both Mito-ChM and Mito-ChMAc selectively depleted intracellular ATP and caused prolonged inhibition of ATP-linked oxygen consumption rate in breast cancer cells, but not in non-cancerous cells. These effects were significantly augmented by inhibition of glycolysis. Mito-ChM and Mito-ChMAc exhibited anti-proliferative effects and cytotoxicity in several breast cancer cells with different genetic background. Furthermore, Mito-ChM selectively accumulated in tumor tissue and inhibited tumor growth in a xenograft model of human breast cancer. We conclude that mitochondria-targeted small molecular weight chromanols exhibit selective anti-proliferative effects and cytotoxicity in multiple breast cancer cells, and that esterification of the hydroxyl group in mito-chromanols is not a critical requirement for its anti-proliferative and cytotoxic effect

  1. Transformation-associated changes in sphingolipid metabolism sensitize cells to lysosomal cell death induced by inhibitors of acid sphingomyelinase

    DEFF Research Database (Denmark)

    Petersen, Nikolaj H T; Olsen, Ole D; Groth-Pedersen, Line

    2013-01-01

    Lysosomal membrane permeabilization and subsequent cell death may prove useful in cancer treatment, provided that cancer cell lysosomes can be specifically targeted. Here, we identify acid sphingomyelinase (ASM) inhibition as a selective means to destabilize cancer cell lysosomes. Lysosome......-destabilizing experimental anticancer agent siramesine inhibits ASM by interfering with the binding of ASM to its essential lysosomal cofactor, bis(monoacylglycero)phosphate. Like siramesine, several clinically relevant ASM inhibitors trigger cancer-specific lysosomal cell death, reduce tumor growth in vivo, and revert...

  2. Depletion of the AP-1 repressor JDP2 induces cell death similar to apoptosis

    DEFF Research Database (Denmark)

    Lerdrup, Mads; Holmberg, Christian Henrik; Dietrich, Nikolaj

    2005-01-01

    JDP2 is a ubiquitously expressed nuclear protein that efficiently represses the activity of the transcription factor AP-1. Thus far, all studies of JDP2 function have relied on the ectopic expression of the protein. In this study, we use a different approach: depletion of JDP2 from cells. Specific...... depletion of JDP2 resulted in p53-independent cell death that resembles apoptosis and was evident at 72 h. The death mechanism was caspase dependent as the cells could be rescued by treatment with caspase inhibitor zVAD. Our studies suggest that JDP2 functions as a general survival protein, not only...

  3. Inflammatory cytokines protect retinal pigment epithelial cells from oxidative stress-induced death

    DEFF Research Database (Denmark)

    Juel, Helene B; Faber, Carsten; Svendsen, Signe Goul

    2013-01-01

    -mediated induction of the anti-oxidative stress response, upregulating protective anti-oxidant pathway(s). These findings suggest caution for the clinical use of anti-inflammatory agents in the management of immune-associated eye diseases such as age-related macular degeneration....... protected from cell death by the addition of PCM. This protection was conferred, at least in part, by IFNγ and TNFα. Cell death induced by H2O2 or NaIO3 was preceded by mitochondrial dysfunction and by p62 upregulation, both of which were attenuated by PCM and/or by IFNγ+TNFα. RPE cells co...

  4. XIAP Restricts TNF- and RIP3-Dependent Cell Death and Inflammasome Activation

    DEFF Research Database (Denmark)

    Yabal, Monica; Müller, Nicole; Adler, Heiko

    2014-01-01

    of XIAP or deletion of its RING domain lead to excessive cell death and IL-1β secretion from dendritic cells triggered by diverse Toll-like receptor stimuli. Aberrant IL-1β secretion is TNF dependent and requires RIP3 but is independent of cIAP1/cIAP2. The observed cell death also requires TNF and RIP3...... but proceeds independently of caspase-1/caspase-11 or caspase-8 function. Loss of XIAP results in aberrantly elevated ubiquitylation of RIP1 outside of TNFR complex I. Virally infected Xiap(-/-) mice present with symptoms reminiscent of XLP-2. Our data show that XIAP controls RIP3-dependent cell death and IL-1...

  5. Role and regulation of apoptotic cell death in the kidney. Y2K update.

    Science.gov (United States)

    Ortiz, A; Lorz, C; Catalan, M P; Justo, P; Egido, J

    2000-08-01

    Apoptosis is an active form of cell death that, in balance with mitosis, regulates cell number. Cell number abnormalities are a frequent feature of renal disease. We now review current concepts on the molecular regulation of apoptotic cell death, including the influence of survival and lethal factors from the extracellular microenvironment as well as the role of intracellular regulators of apoptosis, such as death receptors, proapoptotic and antiapoptotic bcl2-related proteins, the mitochondria and caspases. In addition the role of apoptosis in the genesis, persistence and progression and remodeling and resolution of renal injury is discussed. Information on the expression and function of apoptosis regulatory proteins in specific renal syndromes is summarized. Finally, future perspectives in research and clinical intervention are discussed.

  6. Lysosomal membrane permeabilization in cell death: new evidence and implications for health and disease.

    Science.gov (United States)

    Serrano-Puebla, Ana; Boya, Patricia

    2016-05-01

    Recent studies have demonstrated that, in addition to their central role in cellular catabolic reactions, lysosomes are implicated in many cellular processes, including metabolism, membrane repair, and cell death. Lysosomal membrane permeabilization (LMP) has emerged as a pathway by which cell demise is regulated under physiological conditions and contributes to cell death in many pathological situations. Here, we review the latest evidence on LMP-mediated cell death, the upstream and downstream signals involved, and the role of LMP in the normal physiology of organisms. We also discuss the contributions of lysosomal damage and LMP to the pathogenic features of several disease states, such as lysosomal storage disorders and other neurodegenerative conditions. © 2015 New York Academy of Sciences.

  7. Romo1 expression contributes to oxidative stress-induced death of lung epithelial cells

    International Nuclear Information System (INIS)

    Shin, Jung Ar; Chung, Jin Sil; Cho, Sang-Ho; Kim, Hyung Jung; Yoo, Young Do

    2013-01-01

    Highlights: •Romo1 mediates oxidative stress-induced mitochondrial ROS production. •Romo1 induction by oxidative stress plays an important role in oxidative stress-induced apoptosis. •Romo1 overexpression correlates with epithelial cell death in patients with IPF. -- Abstract: Oxidant-mediated death of lung epithelial cells due to cigarette smoking plays an important role in pathogenesis in lung diseases such as idiopathic pulmonary fibrosis (IPF). However, the exact mechanism by which oxidants induce epithelial cell death is not fully understood. Reactive oxygen species (ROS) modulator 1 (Romo1) is localized in the mitochondria and mediates mitochondrial ROS production through complex III of the mitochondrial electron transport chain. Here, we show that Romo1 mediates mitochondrial ROS production and apoptosis induced by oxidative stress in lung epithelial cells. Hydrogen peroxide (H 2 O 2 ) treatment increased Romo1 expression, and Romo1 knockdown suppressed the cellular ROS levels and cell death triggered by H 2 O 2 treatment. In immunohistochemical staining of lung tissues from patients with IPF, Romo1 was mainly localized in hyperplastic alveolar and bronchial epithelial cells. Romo1 overexpression was detected in 14 of 18 patients with IPF. TUNEL-positive alveolar epithelial cells were also detected in most patients with IPF but not in normal controls. These findings suggest that Romo1 mediates apoptosis induced by oxidative stress in lung epithelial cells

  8. A tomato metacaspase gene is upregulated during programmed cell death in Botrytis cinerea-infected leaves

    NARCIS (Netherlands)

    Hoeberichts, F.A.; Have, ten A.; Woltering, E.J.

    2003-01-01

    Programmed cell death (PCD) in plant cells is often accompanied by biochemical and morphological hallmarks similar to those of animal apoptosis. However, orthologs of animal caspases, cysteinyl aspartate-specific proteases that constitute the core component of animal apoptosis, have not yet been

  9. Apoptosis and Vocal Fold Disease: Clinically Relevant Implications of Epithelial Cell Death

    Science.gov (United States)

    Novaleski, Carolyn K.; Carter, Bruce D.; Sivasankar, M. Preeti; Ridner, Sheila H.; Dietrich, Mary S.; Rousseau, Bernard

    2017-01-01

    Purpose: Vocal fold diseases affecting the epithelium have a detrimental impact on vocal function. This review article provides an overview of apoptosis, the most commonly studied type of programmed cell death. Because apoptosis can damage epithelial cells, this article examines the implications of apoptosis on diseases affecting the vocal fold…

  10. Heat shock transcription factors regulate heat induced cell death in a ...

    Indian Academy of Sciences (India)

    2007-03-29

    Mar 29, 2007 ... Heat shock transcription factors regulate heat induced cell death in a rat ... the synthesis of heat shock proteins (Hsps) which is strictly regulated by ... The lack of Hsp synthesis in these cells was due to a failure in HSF1 DNA ...

  11. Romo1 expression contributes to oxidative stress-induced death of lung epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Jung Ar [Department of Internal Medicine, Yonsei University College of Medicine, Yonsei University Health System, Seoul 135-270 (Korea, Republic of); Chung, Jin Sil [Laboratory of Molecular Cell Biology, College of Life Sciences and Biotechnology, Korea University, Seoul 136-713 (Korea, Republic of); Cho, Sang-Ho [Department of Pathology, Pochon CHA University, College of Medicine, Gyeonggi-do (Korea, Republic of); Kim, Hyung Jung, E-mail: khj57@yuhs.ac.kr [Department of Internal Medicine, Yonsei University College of Medicine, Yonsei University Health System, Seoul 135-270 (Korea, Republic of); Yoo, Young Do, E-mail: ydy1130@korea.ac.kr [Laboratory of Molecular Cell Biology, College of Life Sciences and Biotechnology, Korea University, Seoul 136-713 (Korea, Republic of)

    2013-09-20

    Highlights: •Romo1 mediates oxidative stress-induced mitochondrial ROS production. •Romo1 induction by oxidative stress plays an important role in oxidative stress-induced apoptosis. •Romo1 overexpression correlates with epithelial cell death in patients with IPF. -- Abstract: Oxidant-mediated death of lung epithelial cells due to cigarette smoking plays an important role in pathogenesis in lung diseases such as idiopathic pulmonary fibrosis (IPF). However, the exact mechanism by which oxidants induce epithelial cell death is not fully understood. Reactive oxygen species (ROS) modulator 1 (Romo1) is localized in the mitochondria and mediates mitochondrial ROS production through complex III of the mitochondrial electron transport chain. Here, we show that Romo1 mediates mitochondrial ROS production and apoptosis induced by oxidative stress in lung epithelial cells. Hydrogen peroxide (H{sub 2}O{sub 2}) treatment increased Romo1 expression, and Romo1 knockdown suppressed the cellular ROS levels and cell death triggered by H{sub 2}O{sub 2} treatment. In immunohistochemical staining of lung tissues from patients with IPF, Romo1 was mainly localized in hyperplastic alveolar and bronchial epithelial cells. Romo1 overexpression was detected in 14 of 18 patients with IPF. TUNEL-positive alveolar epithelial cells were also detected in most patients with IPF but not in normal controls. These findings suggest that Romo1 mediates apoptosis induced by oxidative stress in lung epithelial cells.

  12. Pekinenin E Inhibits the Growth of Hepatocellular Carcinoma by Promoting Endoplasmic Reticulum Stress Mediated Cell Death

    Directory of Open Access Journals (Sweden)

    Lu Fan

    2017-06-01

    Full Text Available Hepatocellular carcinoma (HCC is a malignant primary liver cancer with poor prognosis. In the present study, we report that pekinenin E (PE, a casbane diterpenoid derived from the roots of Euphorbia pekinensis, has a strong antitumor activity against human HCC cells both in vitro and in vivo. PE suppressed the growth of human HCC cells Hep G2 and SMMC-7721. In addition, PE-mediated endoplasmic reticulum (ER stress caused increasing expressions of C/EBP homologous protein (CHOP, leading to apoptosis in HCC cells both in vitro and in vivo. Inhibition of ER stress with CHOP small interfering RNA or 4-phenyl-butyric acid partially reversed PE-induced cell death. Furthermore, PE induced S cell cycle arrest, which could also be partially reversed by CHOP knockdown. In all, these findings suggest that PE causes ER stress-associated cell death and cell cycle arrest, and it may serve as a potent agent for curing human HCC.

  13. Nitric oxide and DOPAC-induced cell death: from GSH depletion to mitochondrial energy crisis.

    Science.gov (United States)

    Nunes, Carla; Barbosa, Rui M; Almeida, Leonor; Laranjinha, João

    2011-09-01

    The molecular mechanisms inherent to cell death associated with Parkinson's disease are not clearly understood. Diverse pathways, sequence of events and models have been explored in several studies. Recently, we have proposed an integrative mechanism, encompassing the interaction of nitric oxide (•NO) and a major dopamine metabolite, dihydroxyphenylacetic (DOPAC), leading to a synergistic mitochondrial dysfunction and cell death that may be operative in PD. In this study, we have studied the sequence of events underlying the mechanisms of cell death in PC12 cells exposed to •NO and DOPAC in terms of: a) free radical production; b) modulation by glutathione (GSH); c) energetic status and d) outer membrane mitochondria permeability. Using Electron Paramagnetic Resonance (EPR) it is shown the early production of oxygen free radicals followed by a depletion of GSH reflected by an increase of GSSG/GSH ratio in the cells treated with the mixture of •NO/DOPAC, as compared with the cells individually exposed to each of the stimulus. Glutathione ethyl ester (GSH-EE) and N-acetylcysteine (N