Oxidative damage and cell-programmed death induced in Zea mays L. by allelochemical stress.

Science.gov (United States)

Ciniglia, Claudia; Mastrobuoni, Francesco; Scortichini, Marco; Petriccione, Milena

2015-05-01

The allelochemical stress on Zea mays was analyzed by using walnut husk washing waters (WHWW), a by-product of Juglans regia post-harvest process, which possesses strong allelopathic potential and phytotoxic effects. Oxidative damage and cell-programmed death were induced by WHWW in roots of maize seedlings. Treatment induced ROS burst, with excess of H2O2 content. Enzymatic activities of catalase were strongly increased during the first hours of exposure. The excess in malonildialdehyde following exposure to WHWW confirmed that oxidative stress severely damaged maize roots. Membrane alteration caused a decrease in NADPH oxidase activity along with DNA damage as confirmed by DNA laddering. The DNA instability was also assessed through sequence-related amplified polymorphism assay, thus suggesting the danger of walnut processing by-product and focusing the attention on the necessity of an efficient treatment of WHWW.

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.

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)

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)

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

ALKBH7 drives a tissue and sex-specific necrotic cell death response following alkylation-induced damage

Science.gov (United States)

Jordan, Jennifer J; Chhim, Sophea; Margulies, Carrie M; Allocca, Mariacarmela; Bronson, Roderick T; Klungland, Arne; Samson, Leona D; Fu, Dragony

2017-01-01

Regulated necrosis has emerged as a major cell death mechanism in response to different forms of physiological and pharmacological stress. The AlkB homolog 7 (ALKBH7) protein is required for regulated cellular necrosis in response to chemotherapeutic alkylating agents but its role within a whole organism is unknown. Here, we show that ALKBH7 modulates alkylation-induced cellular death through a tissue and sex-specific mechanism. At the whole-animal level, we find that ALKBH7 deficiency confers increased resistance to MMS-induced toxicity in male but not female mice. Moreover, ALKBH7-deficient mice exhibit protection against alkylation-mediated cytotoxicity in retinal photoreceptor and cerebellar granule cells, two cell types that undergo necrotic death through the initiation of the base excision repair pathway and hyperactivation of the PARP1/ARTD1 enzyme. Notably, the protection against alkylation-induced cerebellar degeneration is specific to ALKBH7-deficient male but not female mice. Our results uncover an in vivo role for ALKBH7 in mediating a sexually dimorphic tissue response to alkylation damage that could influence individual responses to chemotherapies based upon alkylating agents. PMID:28726787

THAP5 is a DNA-binding transcriptional repressor that is regulated in melanoma cells during DNA damage-induced cell death

Energy Technology Data Exchange (ETDEWEB)

Balakrishnan, Meenakshi P.; Cilenti, Lucia; Ambivero, Camilla [Biomolecular Science Center, Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL (United States); Goto, Yamafumi [Department of Dermatology, Shinshu University School of Medicine, Matsumoto (Japan); Takata, Minoru [Department of Dermatology, Okayama University Graduate School of Medical Dentistry and Pharmaceutical Sciences, Okayama (Japan); Turkson, James; Li, Xiaoman Shawn [Biomolecular Science Center, Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL (United States); Zervos, Antonis S., E-mail: azervos@mail.ucf.edu [Biomolecular Science Center, Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL (United States)

2011-01-07

Research highlights: {yields} THAP5 is a DNA-binding protein and a transcriptional repressor. {yields} THAP5 is induced in melanoma cells upon exposure to UV or treatment with cisplatin. {yields} THAP5 induction correlates with the degree of apoptosis in melanoma cell population. {yields} THAP5 is a pro-apoptotic protein involved in melanoma cell death. -- Abstract: THAP5 was originally isolated as a specific interactor and substrate of the mitochondrial pro-apoptotic Omi/HtrA2 protease. It is a human zinc finger protein characterized by a restricted pattern of expression and the lack of orthologs in mouse and rat. The biological function of THAP5 is unknown but our previous studies suggest it could regulate G2/M transition in kidney cells and could be involved in human cardiomyocyte cell death associated with coronary artery disease (CAD). In this report, we expanded our studies on the properties and function of THAP5 in human melanoma cells. THAP5 was expressed in primary human melanocytes as well as in all melanoma cell lines that were tested. THAP5 protein level was significantly induced by UV irradiation or cisplatin treatment, conditions known to cause DNA damage. The induction of THAP5 correlated with a significant increase in apoptotic cell death. In addition, we show that THAP5 is a nuclear protein that could recognize and bind a specific DNA motif. THAP5 could also repress the transcription of a reporter gene in a heterologous system. Our work suggests that THAP5 is a DNA-binding protein and a transcriptional repressor. Furthermore, THAP5 has a pro-apoptotic function and it was induced in melanoma cells under conditions that promoted cell death.

THAP5 is a DNA-binding transcriptional repressor that is regulated in melanoma cells during DNA damage-induced cell death

International Nuclear Information System (INIS)

Balakrishnan, Meenakshi P.; Cilenti, Lucia; Ambivero, Camilla; Goto, Yamafumi; Takata, Minoru; Turkson, James; Li, Xiaoman Shawn; Zervos, Antonis S.

2011-01-01

Research highlights: → THAP5 is a DNA-binding protein and a transcriptional repressor. → THAP5 is induced in melanoma cells upon exposure to UV or treatment with cisplatin. → THAP5 induction correlates with the degree of apoptosis in melanoma cell population. → THAP5 is a pro-apoptotic protein involved in melanoma cell death. -- Abstract: THAP5 was originally isolated as a specific interactor and substrate of the mitochondrial pro-apoptotic Omi/HtrA2 protease. It is a human zinc finger protein characterized by a restricted pattern of expression and the lack of orthologs in mouse and rat. The biological function of THAP5 is unknown but our previous studies suggest it could regulate G2/M transition in kidney cells and could be involved in human cardiomyocyte cell death associated with coronary artery disease (CAD). In this report, we expanded our studies on the properties and function of THAP5 in human melanoma cells. THAP5 was expressed in primary human melanocytes as well as in all melanoma cell lines that were tested. THAP5 protein level was significantly induced by UV irradiation or cisplatin treatment, conditions known to cause DNA damage. The induction of THAP5 correlated with a significant increase in apoptotic cell death. In addition, we show that THAP5 is a nuclear protein that could recognize and bind a specific DNA motif. THAP5 could also repress the transcription of a reporter gene in a heterologous system. Our work suggests that THAP5 is a DNA-binding protein and a transcriptional repressor. Furthermore, THAP5 has a pro-apoptotic function and it was induced in melanoma cells under conditions that promoted cell death.

Dietary broccoli sprouts protect against myocardial oxidative damage and cell death during ischemia-reperfusion.

Science.gov (United States)

Akhlaghi, Masoumeh; Bandy, Brian

2010-09-01

Cruciferous vegetables are known for antioxidant and anti-carcinogenic effects. In the current study we asked whether dietary broccoli sprouts can protect the heart from ischemia-reperfusion. Rats were fed either control diet (sham and control groups) or a diet mixed with 2% dried broccoli sprouts for 10 days. After 10 days the isolated hearts were subjected to ischemia for 20 min and reperfusion for 2 h, and evaluated for cell death, oxidative damage, and Nrf2-regulated phase 2 enzyme activities. Broccoli sprouts feeding inhibited markers of necrosis (lactate dehydrogenase release) and apoptosis (caspase-3 activity) by 78-86%, and decreased indices of oxidative stress (thiobarbituric acid reactive substances and aconitase inactivation) by 82-116%. While broccoli sprouts increased total glutathione and activities of the phase 2 enzymes glutamate cysteine ligase and quinone reductase in liver, they did not affect these in ischemic-reperfused heart. While the mechanism is not clear, the results show that a relatively short dietary treatment with broccoli sprouts can strongly protect the heart against oxidative stress and cell death caused by ischemia-reperfusion.

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.

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.

DNA damage and cellular death in oral mucosa cells of children who have undergone panoramic dental radiography

Energy Technology Data Exchange (ETDEWEB)

Angelieri, Fernanda; Oliveira, Gabriela R. de [Sao Paulo Metodista University (UMESP), Department of Orthodontics, Sao Bernardo do Campo, Sao Paulo (Brazil); Sannomiya, Eduardo K. [Sao Paulo Metodista University (UMESP), Department of Dento-Maxillofacial Radiology, Sao Bernardo do Campo, Sao Paulo (Brazil); Ribeiro, Daniel A. [Federal University of Sao Paulo (UNIFESP), Department of Health Sciences, Santos, Sao Paulo (Brazil); Universidade Federal de Sao Paulo (UNIFESP), Departamento de Ciencias da Saude, Santos, Sao Paulo (Brazil)

2007-06-15

Despite wide use as a diagnostic tool in medical and dental practice, radiography can induce cytotoxic effects and genetic damage. To evaluate DNA damage (micronucleus) and cellular death (pyknosis, karyolysis and karyorrhexis) in exfoliated buccal mucosa cells taken from healthy children following exposure to radiation during dental radiography. A total of 17 children who had undergone panoramic dental radiography were included. We found no statistically significant differences (P > 0.05) between micronucleated oral mucosa cells in children before and after exposure to radiation. On the other hand, radiation did cause other nuclear alterations closely related to cytotoxicity including karyorrhexis, pyknosis and karyolysis. Taken together, these results indicate that panoramic dental radiography might not induce chromosomal damage, but may be cytotoxic. Overall, the results reinforce the importance of evaluating the health side effects of radiography and contribute to the micronucleus database, which will improve our understanding and practice of this methodology in children. (orig.)

DNA damage and cellular death in oral mucosa cells of children who have undergone panoramic dental radiography

International Nuclear Information System (INIS)

Angelieri, Fernanda; Oliveira, Gabriela R. de; Sannomiya, Eduardo K.; Ribeiro, Daniel A.

2007-01-01

Despite wide use as a diagnostic tool in medical and dental practice, radiography can induce cytotoxic effects and genetic damage. To evaluate DNA damage (micronucleus) and cellular death (pyknosis, karyolysis and karyorrhexis) in exfoliated buccal mucosa cells taken from healthy children following exposure to radiation during dental radiography. A total of 17 children who had undergone panoramic dental radiography were included. We found no statistically significant differences (P > 0.05) between micronucleated oral mucosa cells in children before and after exposure to radiation. On the other hand, radiation did cause other nuclear alterations closely related to cytotoxicity including karyorrhexis, pyknosis and karyolysis. Taken together, these results indicate that panoramic dental radiography might not induce chromosomal damage, but may be cytotoxic. Overall, the results reinforce the importance of evaluating the health side effects of radiography and contribute to the micronucleus database, which will improve our understanding and practice of this methodology in children. (orig.)

Targeting Ongoing DNA Damage in Multiple Myeloma: Effects of DNA Damage Response Inhibitors on Plasma Cell Survival

Directory of Open Access Journals (Sweden)

Ana Belén Herrero

2017-05-01

Full Text Available Human myeloma cell lines (HMCLs and a subset of myeloma patients with poor prognosis exhibit high levels of replication stress (RS, leading to DNA damage. In this study, we confirmed the presence of DNA double-strand breaks (DSBs in several HMCLs by measuring γH2AX and RAD51 foci and analyzed the effect of various inhibitors of the DNA damage response on MM cell survival. Inhibition of ataxia telangiectasia and Rad3-related protein (ATR, the main kinase mediating the response to RS, using the specific inhibitor VE-821 induced more cell death in HMCLs than in control lymphoblastoid cells and U266, an HMCL with a low level of DNA damage. The absence of ATR was partially compensated by ataxia telangiectasia-mutated protein (ATM, since chemical inhibition of both kinases using VE-821 and KU-55933 significantly increased the death of MM cells with DNA damage. We found that ATM and ATR are involved in DSB repair by homologous recombination (HR in MM. Inhibition of both kinases resulted in a stronger inhibition that may underlie cell death induction, since abolition of HR using two different inhibitors severely reduced survival of HMCLs that exhibit DNA damage. On the other hand, inhibition of the other route involved in DSB repair, non-homologous end joining (NHEJ, using the DNA-PK inhibitor NU7441, did not affect MM cell viability. Interestingly, we found that NHEJ inhibition did not increase cell death when HR was simultaneously inhibited with the RAD51 inhibitor B02, but it clearly increased the level of cell death when HR was inhibited with the MRE11 inhibitor mirin, which interferes with recombination before DNA resection takes place. Taken together, our results demonstrate for the first time that MM cells with ongoing DNA damage rely on an intact HR pathway, which thereby suggests therapeutic opportunities. We also show that inhibition of HR after the initial step of end resection might be more appropriate for inducing MM cell death, since it

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)

Photodynamic Treatment of Cultured Human Malignant Melanoma cells and Assessment of Resultant Cell Death and Inflicted Bio molecular Damage As Determined by Synchrotron I.R. Radiations

International Nuclear Information System (INIS)

Mamoon, A.; Ruppel, M.; Miller, L.M.; Smith, S.; Tsang, T.; Miller, L.M.

2008-01-01

Malignant melanoma is a very serious skin cancer that if not discovered early and treated by surgery can become fatal. Photodynamic treatment involves the use of a photosensitive dye that is not toxic by itself and is taken up by all cells normal and tumor cells. However it is released from normal cells in a short time while it is kept inside tumor cells for a longer time. A laser light of wave length that is maximally absorbed by the used dye is then used to illuminate tumor cells, still having the dye, and a reaction takes place resulting in the liberation of s inglet oxygen , a very active form of oxygen that damages important biomolecules and results eventually in cell death. The photosensitive dye I ndocyanine green a nd a Ti - Sapphire laser (780 nm wave length ) and power density of 55 m Watt/ cm 2 were used. The percentage of cell death increased slowly with the strength of the PDT until it reached 75% death of the exposed cells at a net dye concentration of 150 u M and laser exposure dose of 60 minute duration.Synchrotron infrared imaging was carried out on control and experimental cultures at the national synchrotron light source (BNL) using FTIR spectro microscopy to reveal the I.R. absorption characteristics of protein, lipids and nucleic acids biomolecules. It was found that increasing the strength of the PDT had an increasingly damaging effect on the concentration of cellular biomolecules, the largest effect being in the protein, lipids and nucleic acid components of the cell. More experiments are planned involving changes in the strengths of the PDT treatments for eventually reaching 100% melanoma cell death

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.

Paraquat initially damages cochlear support cells leading to anoikis-like hair cell death.

Science.gov (United States)

Zhang, Jianhui; Sun, Hong; Salvi, Richard; Ding, Dalian

2018-07-01

Paraquat (PQ), one of the most widely used herbicides, is extremely dangerous because it generates the highly toxic superoxide radical. When paraquat was applied to cochlear organotypic cultures, it not only damaged the outer hair cells (OHCs) and inner hair cells (IHCs), but also caused dislocation of the hair cell rows. We hypothesized that the dislocation arose from damage to the support cells (SCs) that anchors hair cells within the epithelium. To test this hypothesis, rat postnatal cochlear cultures were treated with PQ. Shortly after PQ treatment, the rows of OHCs separated from one another and migrated radially away from IHCs suggesting loss of cell-cell adhesion that hold the hair cells in proper alignment. Hair cells dislocation was associated with extensive loss of SCs in the organ of Corti, loss of tympanic border cells (TBCs) beneath the basilar membrane, the early appearance of superoxide staining and caspase-8 labeling in SCs below the OHCs and disintegration of E-cadherin and β-catenin in the organ of Corti. Damage to the TBCs and SCs occurred prior to loss of OHC or IHC loss suggesting a form of detachment-induced apoptosis referred to as anoikis. Copyright © 2018 Elsevier B.V. All rights reserved.

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

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".

Mechanisms of dealing with DNA damage in terminally differentiated cells

Energy Technology Data Exchange (ETDEWEB)

Fortini, P. [Department of Environment and Primary Prevention, Istituto Superiore di Sanita, Viale Regina Elena 299, 00161 Rome (Italy); Dogliotti, E., E-mail: eugenia.dogliotti@iss.it [Department of Environment and Primary Prevention, Istituto Superiore di Sanita, Viale Regina Elena 299, 00161 Rome (Italy)

2010-03-01

To protect genomic integrity living cells that are continuously exposed to DNA-damaging insults are equipped with an efficient defence mechanism termed the DNA damage response. Its function is to eliminate DNA damage through DNA repair and to remove damaged cells by apoptosis. The DNA damage response has been investigated mainly in proliferating cells, in which the cell cycle machinery is integrated with the DNA damage signalling. The current knowledge of the mechanisms of DNA repair, DNA damage signalling and cell death of post-mitotic cells that have undergone irreversible cell cycle withdrawal will be reviewed. Evidence will be provided that the protection of the genome integrity in terminally differentiated cells is achieved by different strategies than in proliferating cells.

Mechanisms of dealing with DNA damage in terminally differentiated cells

International Nuclear Information System (INIS)

Fortini, P.; Dogliotti, E.

2010-01-01

To protect genomic integrity living cells that are continuously exposed to DNA-damaging insults are equipped with an efficient defence mechanism termed the DNA damage response. Its function is to eliminate DNA damage through DNA repair and to remove damaged cells by apoptosis. The DNA damage response has been investigated mainly in proliferating cells, in which the cell cycle machinery is integrated with the DNA damage signalling. The current knowledge of the mechanisms of DNA repair, DNA damage signalling and cell death of post-mitotic cells that have undergone irreversible cell cycle withdrawal will be reviewed. Evidence will be provided that the protection of the genome integrity in terminally differentiated cells is achieved by different strategies than in proliferating cells.

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

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)

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

Delayed cell death, giant cell formation and chromosome instability induced by X-irradiation in human embryo cells

International Nuclear Information System (INIS)

Roy, K.; Kodama, Seiji; Suzuki, Keiji; Watanabe, Masami

1999-01-01

We studied X-ray-induced delayed cell death, delayed giant cell formation and delayed chromosome aberrations in normal human embryo cells to explore the relationship between initial radiation damage and delayed effect appeared at 14 to 55 population doubling numbers (PDNs) after X-irradiation. The delayed effect was induced in the progeny of X-ray survivors in a dose-dependent manner and recovered with increasing PDNs after X-irradiation. Delayed plating for 24 h post-irradiation reduced both acute and delayed lethal damage, suggesting that potentially lethal damage repair (PLDR) can be effective for relieving the delayed cell death. The chromosome analysis revealed that most of the dicentrics (more than 90%) observed in the progeny of X-ray survivors were not accompanied with fragments, in contrast with those observed in the first mitosis after X-irradiation. The present results indicate that the potentiality of genetic instability is determined during the repair process of initial radiation damage and suggest that the mechanism for formation of delayed chromosome aberrations by radiation might be different from that of direct radiation-induced chromosome aberrations. (author)

Inhibition of exportin-1 function results in rapid cell cycle-associated DNA damage in cancer cells.

Science.gov (United States)

Burke, Russell T; Marcus, Joshua M; Orth, James D

2017-06-13

Selective inhibitors of nuclear export (SINE) are small molecules in development as anti-cancer agents. The first-in-class SINE, selinexor, is in clinical trials for blood and solid cancers. Selinexor forms a covalent bond with exportin-1 at cysteine-528, and blocks its ability to export cargos. Previous work has shown strong cell cycle effects and drug-induced cell death across many different cancer-derived cell lines. Here, we report strong cell cycle-associated DNA double-stranded break formation upon the treatment of cancer cells with SINE. In multiple cell models, selinexor treatment results in the formation of clustered DNA damage foci in 30-40% of cells within 8 hours that is dependent upon cysteine-528. DNA damage strongly correlates with G1/S-phase and decreased DNA replication. Live cell microscopy reveals an association between DNA damage and cell fate. Cells that form damage in G1-phase more often die or arrest, while those damaged in S/G2-phase frequently progress to cell division. Up to half of all treated cells form damage foci, and most cells that die after being damaged, were damaged in G1-phase. By comparison, non-transformed cell lines show strong cell cycle effects but little DNA damage and less death than cancer cells. Significant drug combination effects occur when selinexor is paired with different classes of agents that either cause DNA damage or that diminish DNA damage repair. These data present a novel effect of exportin-1 inhibition and provide a strong rationale for multiple combination treatments of selinexor with agents that are currently in use for the treatment of different solid cancers.

Senescence, apoptosis or autophagy? When a damaged cell must decide its path--a mini-review.

Science.gov (United States)

Vicencio, José Miguel; Galluzzi, Lorenzo; Tajeddine, Nicolas; Ortiz, Carla; Criollo, Alfredo; Tasdemir, Ezgi; Morselli, Eugenia; Ben Younes, Amena; Maiuri, Maria Chiara; Lavandero, Sergio; Kroemer, Guido

2008-01-01

Many features of aging result from the incapacity of cells to adapt to stress conditions. When damage accumulates irreversibly, mitotic cells from renewable tissues rely on either of two mechanisms to avoid replication. They can permanently arrest the cell cycle (cellular senescence) or trigger cell death programs. Apoptosis (self-killing) is the best-described form of programmed cell death, but autophagy (self-eating), which is a lysosomal degradation pathway essential for homeostasis, reportedly contributes to cell death as well. Unlike mitotic cells, postmitotic cells like neurons or cardiomyocytes cannot become senescent since they are already terminally differentiated. The fate of these cells entirely depends on their ability to cope with stress. Autophagy then operates as a major homeostatic mechanism to eliminate damaged organelles, long-lived or aberrant proteins and superfluous portions of the cytoplasm. In this mini-review, we briefly summarize the molecular networks that allow damaged cells either to adapt to stress or to engage in programmed-cell-death pathways. (c) 2008 S. Karger AG, Basel.

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

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

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.

Role of apoptosis and necrosis in cell death induced by nanoparticle-mediated photothermal therapy

International Nuclear Information System (INIS)

Pattani, Varun P.; Shah, Jay; Atalis, Alexandra; Sharma, Anirudh; Tunnell, James W.

2015-01-01

Current cancer therapies can cause significant collateral damage due to a lack of specificity and sensitivity. Therefore, we explored the cell death pathway response to gold nanorod (GNR)-mediated photothermal therapy as a highly specific cancer therapeutic to understand the role of apoptosis and necrosis during intense localized heating. By developing this, we can optimize photothermal therapy to induce a maximum of ‘clean’ cell death pathways, namely apoptosis, thereby reducing external damage. GNRs were targeted to several subcellular localizations within colorectal tumor cells in vitro, and the cell death pathways were quantitatively analyzed after photothermal therapy using flow cytometry. In this study, we found that the cell death response to photothermal therapy was dependent on the GNR localization. Furthermore, we demonstrated that nanorods targeted to the perinuclear region irradiated at 37.5 W/cm 2 laser fluence rate led to maximum cell destruction with the ‘cleaner’ method of apoptosis, at similar percentages as other anti-cancer targeted therapies. We believe that this indicates the therapeutic potential for GNR-mediated photothermal therapy to treat cancer effectively without causing damage to surrounding tissue

Role of apoptosis and necrosis in cell death induced by nanoparticle-mediated photothermal therapy

Energy Technology Data Exchange (ETDEWEB)

Pattani, Varun P., E-mail: varun.pattani@utexas.edu; Shah, Jay; Atalis, Alexandra; Sharma, Anirudh; Tunnell, James W. [The University of Texas at Austin, Department of Biomedical Engineering (United States)

2015-01-15

Current cancer therapies can cause significant collateral damage due to a lack of specificity and sensitivity. Therefore, we explored the cell death pathway response to gold nanorod (GNR)-mediated photothermal therapy as a highly specific cancer therapeutic to understand the role of apoptosis and necrosis during intense localized heating. By developing this, we can optimize photothermal therapy to induce a maximum of ‘clean’ cell death pathways, namely apoptosis, thereby reducing external damage. GNRs were targeted to several subcellular localizations within colorectal tumor cells in vitro, and the cell death pathways were quantitatively analyzed after photothermal therapy using flow cytometry. In this study, we found that the cell death response to photothermal therapy was dependent on the GNR localization. Furthermore, we demonstrated that nanorods targeted to the perinuclear region irradiated at 37.5 W/cm{sup 2} laser fluence rate led to maximum cell destruction with the ‘cleaner’ method of apoptosis, at similar percentages as other anti-cancer targeted therapies. We believe that this indicates the therapeutic potential for GNR-mediated photothermal therapy to treat cancer effectively without causing damage to surrounding tissue.

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)

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.

Mechanisms of Sensorineural Cell Damage, Death and Survival in the Cochlea

Directory of Open Access Journals (Sweden)

Allen Frederic Ryan

2015-04-01

Full Text Available The majority of acquired hearing loss, including presbycusis, is caused by irreversible damage to the sensorineural tissues of the cochlea. This article reviews the intracellular mechanisms that contribute to sensorineural damage in the cochlea, as well as the survival signaling pathways that can provide endogenous protection and tissue rescue. These data have primarily been generated in hearing loss not directly related to age. However, there is evidence that similar mechanisms operate in presbycusis. Moreover, accumulation of damage from other causes can contribute to age-related hearing loss. Potential therapeutic interventions to balance opposing but interconnected cell damage and survival pathways, such as antioxidants, anti-apoptotics, and pro-inflammatory cytokine inhibitors, are also discussed.

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

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.

Mitochondrion-mediated cell death: dissecting yeast apoptosis for a better understanding of neurodegeneration

Energy Technology Data Exchange (ETDEWEB)

Braun, Ralf J., E-mail: ralf.braun@uni-bayreuth.de [Institut für Zellbiologie, Universität Bayreuth, Bayreuth (Germany)

2012-11-28

Mitochondrial damage and dysfunction are common hallmarks for neurodegenerative disorders, including Alzheimer, Parkinson, Huntington diseases, and the motor neuron disorder amyotrophic lateral sclerosis. Damaged mitochondria pivotally contribute to neurotoxicity and neuronal cell death in these disorders, e.g., due to their inability to provide the high energy requirements for neurons, their generation of reactive oxygen species (ROS), and their induction of mitochondrion-mediated cell death pathways. Therefore, in-depth analyses of the underlying molecular pathways, including cellular mechanisms controlling the maintenance of mitochondrial function, is a prerequisite for a better understanding of neurodegenerative disorders. The yeast Saccharomyces cerevisiae is an established model for deciphering mitochondrial quality control mechanisms and the distinct mitochondrial roles during apoptosis and programmed cell death. Cell death upon expression of various human neurotoxic proteins has been characterized in yeast, revealing neurotoxic protein-specific differences. This review summarizes how mitochondria are affected in these neurotoxic yeast models, and how they are involved in the execution and prevention of cell death. I will discuss to which extent this mimics the situation in other neurotoxic model systems, and how this may contribute to a better understanding of the mitochondrial roles in the human disorders.

Mitochondrion-mediated cell death: dissecting yeast apoptosis for a better understanding of neurodegeneration

International Nuclear Information System (INIS)

Braun, Ralf J.

2012-01-01

Mitochondrial damage and dysfunction are common hallmarks for neurodegenerative disorders, including Alzheimer, Parkinson, Huntington diseases, and the motor neuron disorder amyotrophic lateral sclerosis. Damaged mitochondria pivotally contribute to neurotoxicity and neuronal cell death in these disorders, e.g., due to their inability to provide the high energy requirements for neurons, their generation of reactive oxygen species (ROS), and their induction of mitochondrion-mediated cell death pathways. Therefore, in-depth analyses of the underlying molecular pathways, including cellular mechanisms controlling the maintenance of mitochondrial function, is a prerequisite for a better understanding of neurodegenerative disorders. The yeast Saccharomyces cerevisiae is an established model for deciphering mitochondrial quality control mechanisms and the distinct mitochondrial roles during apoptosis and programmed cell death. Cell death upon expression of various human neurotoxic proteins has been characterized in yeast, revealing neurotoxic protein-specific differences. This review summarizes how mitochondria are affected in these neurotoxic yeast models, and how they are involved in the execution and prevention of cell death. I will discuss to which extent this mimics the situation in other neurotoxic model systems, and how this may contribute to a better understanding of the mitochondrial roles in the human disorders.

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.

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

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

Sensitization of melanoma cells to alkylating agent-induced DNA damage and cell death via orchestrating oxidative stress and IKKβ inhibition

Directory of Open Access Journals (Sweden)

Anfernee Kai-Wing Tse

2017-04-01

Full Text Available Nitrosourea represents one of the most active classes of chemotherapeutic alkylating agents for metastatic melanoma. Treatment with nitrosoureas caused severe systemic side effects which hamper its clinical use. Here, we provide pharmacological evidence that reactive oxygen species (ROS induction and IKKβ inhibition cooperatively enhance nitrosourea-induced cytotoxicity in melanoma cells. We identified SC-514 as a ROS-inducing IKKβ inhibitor which enhanced the function of nitrosoureas. Elevated ROS level results in increased DNA crosslink efficiency triggered by nitrosoureas and IKKβ inhibition enhances DNA damage signals and sensitizes nitrosourea-induced cell death. Using xenograft mouse model, we confirm that ROS-inducing IKKβ inhibitor cooperates with nitrosourea to reduce tumor size and malignancy in vivo. Taken together, our results illustrate a new direction in nitrosourea treatment, and reveal that the combination of ROS-inducing IKKβ inhibitors with nitrosoureas can be potentially exploited for melanoma therapy.

Differential expression of the klf6 tumor suppressor gene upon cell damaging treatments in cancer cells

International Nuclear Information System (INIS)

Gehrau, Ricardo C.; D'Astolfo, Diego S.; Andreoli, Veronica; Bocco, Jose L.; Koritschoner, Nicolas P.

2011-01-01

The mammalian Krueppel-like factor 6 (KLF6) is involved in critical roles such as growth-related signal transduction, cell proliferation and differentiation, development, apoptosis and angiogenesis. Also, KLF6 appears to be an emerging key factor during cancer development and progression. Its expression is thoroughly regulated by several cell-damaging stimuli. DNA damaging agents at lethal concentrations induce a p53-independent down-regulation of the klf6 gene. To investigate the impact of external stimuli on human klf6 gene expression, its mRNA level was analyzed using a cancer cell line profiling array system, consisting in an assortment of immobilized cDNAs from multiple cell lines treated with several cell-damaging agents at growth inhibitory concentrations (IC 50 ). Cell-damaging agents affected the klf6 expression in 62% of the cDNA samples, though the expression pattern was not dependent on the cell origin type. Interestingly, significant differences (p 50 concentrations of physical and chemical stimuli in a p53-dependent manner. Most of these agents are frequently used in cancer therapy. Induction of klf6 expression in the absence of functional p53 directly correlates with cell death triggered by these compounds, whereas it is down-regulated in p53+/+ cells. Hence, klf6 expression level could represent a valuable marker for the efficiency of cell death upon cancer treatment.

Sensitization of melanoma cells to alkylating agent-induced DNA damage and cell death via orchestrating oxidative stress and IKKβ inhibition.

Science.gov (United States)

Tse, Anfernee Kai-Wing; Chen, Ying-Jie; Fu, Xiu-Qiong; Su, Tao; Li, Ting; Guo, Hui; Zhu, Pei-Li; Kwan, Hiu-Yee; Cheng, Brian Chi-Yan; Cao, Hui-Hui; Lee, Sally Kin-Wah; Fong, Wang-Fun; Yu, Zhi-Ling

2017-04-01

Nitrosourea represents one of the most active classes of chemotherapeutic alkylating agents for metastatic melanoma. Treatment with nitrosoureas caused severe systemic side effects which hamper its clinical use. Here, we provide pharmacological evidence that reactive oxygen species (ROS) induction and IKKβ inhibition cooperatively enhance nitrosourea-induced cytotoxicity in melanoma cells. We identified SC-514 as a ROS-inducing IKKβ inhibitor which enhanced the function of nitrosoureas. Elevated ROS level results in increased DNA crosslink efficiency triggered by nitrosoureas and IKKβ inhibition enhances DNA damage signals and sensitizes nitrosourea-induced cell death. Using xenograft mouse model, we confirm that ROS-inducing IKKβ inhibitor cooperates with nitrosourea to reduce tumor size and malignancy in vivo. Taken together, our results illustrate a new direction in nitrosourea treatment, and reveal that the combination of ROS-inducing IKKβ inhibitors with nitrosoureas can be potentially exploited for melanoma therapy. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

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

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.

Cancer cells recovering from damage exhibit mitochondrial restructuring and increased aerobic glycolysis

Energy Technology Data Exchange (ETDEWEB)

Akakura, Shin; Ostrakhovitch, Elena; Sanokawa-Akakura, Reiko [Frontiers in Bioscience Research Institute in Aging and Cancer, University of California, Irvine, CA (United States); Tabibzadeh, Siamak, E-mail: fbs@bioscience.org [Frontiers in Bioscience Research Institute in Aging and Cancer, University of California, Irvine, CA (United States); Dept of Oncologic Radiology, University of California, Irvine, CA (United States)

2014-06-13

Highlights: • Some cancer cells recover from severe damage that causes cell death in majority of cells. • Damage-Recovered (DR) cancer cells show reduced mitochondria, mDNA and mitochondrial enzymes. • DR cells show increased aerobic glycolysis, ATP, cell proliferation, and resistance to damage. • DR cells recovered from in vivo damage also show increased glycolysis and proliferation rate. - Abstract: Instead of relying on mitochondrial oxidative phosphorylation, most cancer cells rely heavily on aerobic glycolysis, a phenomenon termed as “the Warburg effect”. We considered that this effect is a direct consequence of damage which persists in cancer cells that recover from damage. To this end, we studied glycolysis and rate of cell proliferation in cancer cells that recovered from severe damage. We show that in vitro Damage-Recovered (DR) cells exhibit mitochondrial structural remodeling, display Warburg effect, and show increased in vitro and in vivo proliferation and tolerance to damage. To test whether cancer cells derived from tumor microenvironment can show similar properties, we isolated Damage-Recovered (T{sup DR}) cells from tumors. We demonstrate that T{sup DR} cells also show increased aerobic glycolysis and a high proliferation rate. These findings show that Warburg effect and its consequences are induced in cancer cells that survive severe damage.

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.

Differential expression of the klf6 tumor suppressor gene upon cell damaging treatments in cancer cells

Energy Technology Data Exchange (ETDEWEB)

Gehrau, Ricardo C.; D' Astolfo, Diego S.; Andreoli, Veronica [Centro de Investigaciones en Bioquimica Clinica e Inmunologia (CIBICI-CONICET), Departamento de Bioquimica Clinica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Haya de la Torre y Medina Allende, Ciudad Universitaria, 5000 Cordoba (Argentina); Bocco, Jose L., E-mail: jbocco@fcq.unc.edu.ar [Centro de Investigaciones en Bioquimica Clinica e Inmunologia (CIBICI-CONICET), Departamento de Bioquimica Clinica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Haya de la Torre y Medina Allende, Ciudad Universitaria, 5000 Cordoba (Argentina); Koritschoner, Nicolas P. [Centro de Investigaciones en Bioquimica Clinica e Inmunologia (CIBICI-CONICET), Departamento de Bioquimica Clinica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Haya de la Torre y Medina Allende, Ciudad Universitaria, 5000 Cordoba (Argentina)

2011-02-10

The mammalian Krueppel-like factor 6 (KLF6) is involved in critical roles such as growth-related signal transduction, cell proliferation and differentiation, development, apoptosis and angiogenesis. Also, KLF6 appears to be an emerging key factor during cancer development and progression. Its expression is thoroughly regulated by several cell-damaging stimuli. DNA damaging agents at lethal concentrations induce a p53-independent down-regulation of the klf6 gene. To investigate the impact of external stimuli on human klf6 gene expression, its mRNA level was analyzed using a cancer cell line profiling array system, consisting in an assortment of immobilized cDNAs from multiple cell lines treated with several cell-damaging agents at growth inhibitory concentrations (IC{sub 50}). Cell-damaging agents affected the klf6 expression in 62% of the cDNA samples, though the expression pattern was not dependent on the cell origin type. Interestingly, significant differences (p < 0.0001) in KLF6 mRNA levels were observed depending on the cellular p53 status upon cell damage. KLF6 expression was significantly increased in 63% of p53-deficient cells (122/195). Conversely, KLF6 mRNA level decreased nearly 4 fold in more than 70% of p53+/+ cells. In addition, klf6 gene promoter activity was down-regulated by DNA damaging agents in cells expressing the functional p53 protein whereas it was moderately increased in the absence of functional p53. Consistent results were obtained for the endogenous KLF6 protein level. Results indicate that human klf6 gene expression is responsive to external cell damage mediated by IC{sub 50} concentrations of physical and chemical stimuli in a p53-dependent manner. Most of these agents are frequently used in cancer therapy. Induction of klf6 expression in the absence of functional p53 directly correlates with cell death triggered by these compounds, whereas it is down-regulated in p53+/+ cells. Hence, klf6 expression level could represent a valuable

DNA-repair, cell killing and normal tissue damage

International Nuclear Information System (INIS)

Dahm-Daphi, J.; Dikomey, E.; Brammer, I.

1998-01-01

Background: Side effects of radiotherapy in normal tissue is determined by a variety of factors of which cellular and genetic contributions are described here. Material and methods: Review. Results: Normal tissue damage after irradiation is largely due to loss of cellular proliferative capacity. This can be due to mitotic cell death, apoptosis, or terminal differentiation. Dead or differentiated cells release cytokines which additionally modulate the tissue response. DNA damage, in particular non-reparable or misrepaired double-strand breaks are considered the basic lesion leading to G1-arrest and ultimately to cell inactivation. Conclusion: Evidence for genetic bases of normal tissue response, cell killing and DNA-repair capacity is presented. However, a direct link of all 3 endpoints has not yet been proved directly. (orig.) [de

Hypoxia-ischemia and retinal ganglion cell damage

Directory of Open Access Journals (Sweden)

Charanjit Kaur

2008-08-01

Full Text Available Charanjit Kaur1, Wallace S Foulds2, Eng-Ang Ling11Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; 2Singapore Eye Research Institute, SingaporeAbstract: Retinal hypoxia is the potentially blinding mechanism underlying a number of sight-threatening disorders including central retinal artery occlusion, ischemic central retinal vein thrombosis, complications of diabetic eye disease and some types of glaucoma. Hypoxia is implicated in loss of retinal ganglion cells (RGCs occurring in such conditions. RGC death occurs by apoptosis or necrosis. Hypoxia-ischemia induces the expression of hypoxia inducible factor-1α and its target genes such as vascular endothelial growth factor (VEGF and nitric oxide synthase (NOS. Increased production of VEGF results in disruption of the blood retinal barrier leading to retinal edema. Enhanced expression of NOS results in increased production of nitric oxide which may be toxic to the cells resulting in their death. Excess glutamate release in hypoxic-ischemic conditions causes excitotoxic damage to the RGCs through activation of ionotropic and metabotropic glutamate receptors. Activation of glutamate receptors is thought to initiate damage in the retina by a cascade of biochemical effects such as neuronal NOS activation and increase in intracellular Ca2+ which has been described as a major contributing factor to RGC loss. Excess production of proinflammatory cytokines also mediates cell damage. Besides the above, free-radicals generated in hypoxic-ischemic conditions result in RGC loss because of an imbalance between antioxidant- and oxidant-generating systems. Although many advances have been made in understanding the mediators and mechanisms of injury, strategies to improve the damage are lacking. Measures to prevent neuronal injury have to be developed.Keywords: retinal hypoxia, retinal ganglion cells, glutamate receptors, neuronal injury, retina

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.

TRAIL enhances paracetamol-induced liver sinusoidal endothelial cell death in a Bim- and Bid-dependent manner

Science.gov (United States)

Badmann, A; Langsch, S; Keogh, A; Brunner, T; Kaufmann, T; Corazza, N

2012-01-01

Paracetamol (acetaminophen, APAP) is a universally used analgesic and antipyretic agent. Considered safe at therapeutic doses, overdoses cause acute liver damage characterized by centrilobular hepatic necrosis. One of the major clinical problems of paracetamol-induced liver disease is the development of hemorrhagic alterations. Although hepatocytes represent the main target of the cytotoxic effect of paracetamol overdose, perturbations within the endothelium involving morphological changes of liver sinusoidal endothelial cells (LSECs) have also been described in paracetamol-induced liver disease. Recently, we have shown that paracetamol-induced liver damage is synergistically enhanced by the TRAIL signaling pathway. As LSECs are constantly exposed to activated immune cells expressing death ligands, including TRAIL, we investigated the effect of TRAIL on paracetamol-induced LSEC death. We here demonstrate for the first time that TRAIL strongly enhances paracetamol-mediated LSEC death with typical features of apoptosis. Inhibition of caspases using specific inhibitors resulted in a strong reduction of cell death. TRAIL appears to enhance paracetamol-induced LSEC death via the activation of the pro-apoptotic BH3-only proteins Bid and Bim, which initiate the mitochondrial apoptotic pathway. Taken together this study shows that the liver endothelial layer, mainly LSECs, represent a direct target of the cytotoxic effect of paracetamol and that activation of TRAIL receptor synergistically enhances paracetamol-induced LSEC death via the mitochondrial apoptotic pathway. TRAIL-mediated acceleration of paracetamol-induced cell death may thus contribute to the pathogenesis of paracetamol-induced liver damage. PMID:23254290

Nuclear DAMP complex-mediated RAGE-dependent macrophage cell death

Energy Technology Data Exchange (ETDEWEB)

Chen, Ruochan [Department of Surgery, University of Pittsburgh, Pittsburgh, PA 15213 (United States); Department of Infectious Diseases and State Key Lab of Viral Hepatitis, Xiangya Hospital, Central South University, Changsha, Hunan 410008 (China); Fu, Sha; Fan, Xue-Gong [Department of Infectious Diseases and State Key Lab of Viral Hepatitis, Xiangya Hospital, Central South University, Changsha, Hunan 410008 (China); Lotze, Michael T.; Zeh, Herbert J. [Department of Surgery, University of Pittsburgh, Pittsburgh, PA 15213 (United States); Tang, Daolin, E-mail: tangd2@upmc.edu [Department of Surgery, University of Pittsburgh, Pittsburgh, PA 15213 (United States); Kang, Rui, E-mail: kangr@upmc.edu [Department of Surgery, University of Pittsburgh, Pittsburgh, PA 15213 (United States)

2015-03-13

High mobility group box 1 (HMGB1), histone, and DNA are essential nuclear components involved in the regulation of chromosome structure and function. In addition to their nuclear function, these molecules act as damage-associated molecular patterns (DAMPs) alone or together when released extracellularly. The synergistic effect of these nuclear DNA-HMGB1-histone complexes as DAMP complexes (nDCs) on immune cells remains largely unexplored. Here, we demonstrate that nDCs limit survival of macrophages (e.g., RAW264.7 and peritoneal macrophages) but not cancer cells (e.g., HCT116, HepG2 and Hepa1-6). nDCs promote production of inflammatory tumor necrosis factor α (TNFα) release, triggering reactive oxygen species-dependent apoptosis and necrosis. Moreover, the receptor for advanced glycation end products (RAGE), but not toll-like receptor (TLR)-4 and TLR-2, was required for Akt-dependent TNFα release and subsequent cell death following treatment with nDCs. Genetic depletion of RAGE by RNAi, antioxidant N-Acetyl-L-cysteine, and TNFα neutralizing antibody significantly attenuated nDC-induced cell death. These findings provide evidence supporting novel signaling mechanisms linking nDCs and inflammation in macrophage cell death. - Highlights: • Nuclear DAMP complexes (nDCs) selectively induce cell death in macrophages, but not cancer cells. • TNFα-mediated oxidative stress is required for nDC-induced death. • RAGE-mediated Akt activation is required for nDC-induced TNFα release. • Blocking RAGE and TNFα inhibits nDC-induced macrophage cell death.

The influence of the surface chemistry of silver nanoparticles on cell death

International Nuclear Information System (INIS)

Sur, Ilknur; Altunbek, Mine; Kahraman, Mehmet; Culha, Mustafa

2012-01-01

The influence of the surface chemistry of silver nanoparticles (AgNPs) on p53 mediated cell death was evaluated using human dermal fibroblast (HDF) and lung cancer (A549) cells. The citrate reduced AgNPs (C-AgNPs) were modified with either lactose (L-AgNPs) or a 12-base long oligonucleotide (O-AgNPs). Both unmodified and modified AgNPs showed increased concentration and time dependent cytotoxicity and genotoxicity causing an increased p53 up-regulation within 6 h and led to apoptotic or necrotic cell deaths. The C-AgNPs induced more cytotoxicity and cellular DNA damage than the surface modified AgNPs. Modifying the C-AgNPs with lactose or the oligonucleotide reduced both necrotic and apoptotic cell deaths in the HDF cells. The C-AgNPs caused an insignificant necrosis in A549 cells whereas the modified AgNPs caused necrosis and apoptosis in both cell types. Compared to the O-AgNPs, the L-AgNPs triggered more cellular DNA damage, which led to up-regulation of p53 gene inducing apoptosis in A549 cells compared to HDF cells. This suggests that the different surface chemistries of the AgNPs cause different cellular responses that may be important not only for their use in medicine but also for reducing their toxicity. (paper)

Mycolactone cytotoxicity in Schwann cells could explain nerve damage in Buruli ulcer.

Directory of Open Access Journals (Sweden)

Junichiro En

2017-08-01

Full Text Available Buruli ulcer is a chronic painless skin disease caused by Mycobacterium ulcerans. The local nerve damage induced by M. ulcerans invasion is similar to the nerve damage evoked by the injection of mycolactone in a Buruli ulcer mouse model. In order to elucidate the mechanism of this nerve damage, we tested and compared the cytotoxic effect of synthetic mycolactone A/B on cultured Schwann cells, fibroblasts and macrophages. Mycolactone induced much higher cell death and apoptosis in Schwann cell line SW10 than in fibroblast line L929. These results suggest that mycolactone is a key substance in the production of nerve damage of Buruli ulcer.

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

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

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

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.

Cigarette smoke-induced cell death of a spermatocyte cell line can be prevented by inactivating the Aryl hydrocarbon receptor

Science.gov (United States)

Esakky, P; Hansen, D A; Drury, A M; Cusumano, A; Moley, K H

2015-01-01

Cigarette smoke exposure causes germ cell death during spermatogenesis. Our earlier studies demonstrated that cigarette smoke condensate (CSC) causes spermatocyte cell death in vivo and growth arrest of the mouse spermatocyte cell line (GC-2spd(ts)) in vitro via the aryl hydrocarbon receptor (AHR). We hypothesize here that inactivation of AHR could prevent the CSC-induced cell death in spermatocytes. We demonstrate that CSC exposure generates oxidative stress, which differentially regulates mitochondrial apoptosis in GC-2spd(ts) and wild type (WT) and AHR knockout (AHR-KO) mouse embryonic fibroblasts (MEFs). SiRNA-mediated silencing of Ahr augments the extent of CSC-mediated cellular damage while complementing the AHR-knockout condition. Pharmacological inhibition using the AHR-antagonist (CH223191) modulates the CSC-altered expression of apoptotic proteins and significantly abrogates DNA fragmentation though the cleavage of PARP appears AHR independent. Pretreatment with CH223191 at concentrations above 50 μM significantly prevents the CSC-induced activation of caspase-3/7 and externalization of phosphatidylserine in the plasma membrane. However, MAPK inhibitors alone or together with CH223191 could not prevent the membrane damage upon CSC addition and the caspase-3/7 activation and membrane damage in AHR-deficient MEF indicates the interplay of multiple cell signaling and cytoprotective ability of AHR. Thus the data obtained on one hand signifies the protective role of AHR in maintaining normal cellular homeostasis and the other, could be a potential prophylactic therapeutic target to promote cell survival and growth under cigarette smoke exposed environment by receptor antagonism via CH223191-like mechanism. Antagonist-mediated inactivation of the aryl hydrocarbon receptor blocks downstream events leading to cigarette smoke-induced cell death of a spermatocyte cell line. PMID:27551479

miR-Let7A Controls the Cell Death and Tight Junction Density of Brain Endothelial Cells under High Glucose Condition.

Science.gov (United States)

Song, Juhyun; Yoon, So Ra; Kim, Oh Yoen

2017-01-01

Hyperglycemia-induced stress in the brain of patients with diabetes triggers the disruption of blood-brain barrier (BBB), leading to diverse neurological diseases including stroke and dementia. Recently, the role of microRNA becomes an interest in the research for deciphering the mechanism of brain endothelial cell damage under hyperglycemia. Therefore, we investigated whether mircoRNA Let7A (miR-Let7A) controls the damage of brain endothelial (bEnd.3) cells against high glucose condition. Cell viability, cell death marker expressions (p-53, Bax, and cleaved poly ADP-ribose polymerase), the loss of tight junction proteins (ZO-1 and claudin-5), proinflammatory response (interleukin-6, tumor necrosis factor- α ), inducible nitric oxide synthase, and nitrite production were confirmed using MTT, reverse transcription-PCR, quantitative-PCR, Western blotting, immunofluorescence, and Griess reagent assay. miR-Let7A overexpression significantly prevented cell death and loss of tight junction proteins and attenuated proinflammatory response and nitrite production in the bEnd.3 cells under high glucose condition. Taken together, we suggest that miR-Let7A may attenuate brain endothelial cell damage by controlling cell death signaling, loss of tight junction proteins, and proinflammatory response against high glucose stress. In the future, the manipulation of miR-Let7A may be a novel solution in controlling BBB disruption which leads to the central nervous system diseases.

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)

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.

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

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

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.

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.

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.

BH3-mimetics- and cisplatin-induced cell death proceeds through different pathways depending on the availability of death-related cellular components.

Directory of Open Access Journals (Sweden)

Vicente Andreu-Fernández

Full Text Available BACKGROUND: Owing to their important function in regulating cell death, pharmacological inhibition of Bcl-2 proteins by dubbed BH3-mimetics is a promising strategy for apoptosis induction or sensitization to chemotherapy. However, the role of Apaf-1, the main protein constituent of the apoptosome, in the process has yet not been analyzed. Furthermore as new chemotherapeutics develop, the possible chemotherapy-induced toxicity to rapidly dividing normal cells, especially sensitive differentiated cells, has to be considered. Such undesirable effects would probably be ameliorated by selectively and locally inhibiting apoptosis in defined sensitive cells. METHODOLOGY AND PRINCIPAL FINDINGS: Mouse embryonic fibroblasts (MEFS from Apaf-1 knock out mouse (MEFS KO Apaf-1 and Bax/Bak double KO (MEFS KO Bax/Bak, MEFS from wild-type mouse (MEFS wt and human cervix adenocarcinoma (HeLa cells were used to comparatively investigate the signaling cell death-induced pathways of BH3-mimetics, like ABT737 and GX15-070, with DNA damage-inducing agent cisplatin (cis-diammineplatinum(II dichloride, CDDP. The study was performed in the absence or presence of apoptosis inhibitors namely, caspase inhibitors or apoptosome inhibitors. BH3-mimetic ABT737 required of Apaf-1 to exert its apoptosis-inducing effect. In contrast, BH3-mimetic GX15-070 and DNA damage-inducing CDDP induced cell death in the absence of both Bax/Bak and Apaf-1. GX15-070 induced autophagy-based cell death in all the cell lines analyzed. MEFS wt cells were protected from the cytotoxic effects of ABT737 and CDDP by chemical inhibition of the apoptosome through QM31, but not by using general caspase inhibitors. CONCLUSIONS: BH3-mimetic ABT737 not only requires Bax/Bak to exert its apoptosis-inducing effect, but also Apaf-1, while GX15-070 and CDDP induce different modalities of cell death in the absence of Bax/Bak or Apaf-1. Inclusion of specific Apaf-1 inhibitors in topical and well

DNA Damages and White Blood Cell Death Processes in Victims with Severe Injury

Directory of Open Access Journals (Sweden)

V. V. Moroz

2014-01-01

Full Text Available Objective. To study the mechanisms of posttraumatic changes in the blood cells, by investigating DNA damages associat ed with hypoxia caused by massive blood loss (BL in severe injury.Subjects and methods. Ninetyfive patients aged 40.6±16.5 years (from 20 to 79 years who had sustained severe mechanical injury with different BL volumes (BLV (from 100 to 4000 ml and hemodynamic disorders were examined to study DNA damages and white blood cell necrotic and apop totic processes. In terms of the victims' weight, the mean BL was 21.5±16.5 ml/kg (from 1.4 to 61.5 ml/kg. The victimswere divided into 4 groups according to BLV: 1 26 victims whose BLV was less than 750 ml (5.93±2.41 ml/kg (grade I BL; 2 23 victims whose BLV was 750—1500 ml (11.5±1.5 ml/kg (grade 2 BL; 3 23 victims whose BLV was 1500—2000 ml (23.8±4.0 ml/kg (grade 3 BL; 4 23 victims whose BLV was over 2000 ml (45.6±10.1 ml/kg (grade 4 BL, according to the type of injury: 1 severe skeletal injury (SSI (n=17; 2 brain injury (BI (n=43; 3 a concurrence of SSI and BI (SSI+BI (n=35; according to the development of infectious complications: 1 69 victims who developed infectious com plications on days 5—7 postinjury; 2 26 victims who did not. To evaluate the impact of hypoxia on DNA damages, white blood cell apoptotic and necrotic processes, the victims were divided into 2 groups: 1 hypoxia (18 of the 95 victims who had 4 altered indicators, such as capillary blood pO2, plasma lactate levels, pH, and BE; 2 no hypoxia (10 of the 95 victims whose indicators were within the normal range. DNA damages and necrotic and apoptotic changes in the white blood cells were assessed by the DNA comet assay. The plasma concentration of extracellular DNA was fluorometrically determined using a QuantiTTM HS DNA Assay Kit (Invitrogen, USA. That of 8hydroxy2deoxyguanosine was estimated by enzyme immunoassay employing an 8hydroxy2deoxyGuanosine EIA Kit (Cayman Chemical, USA. The levels of cas

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

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…

Dehydroabietic Acid Derivative QC4 Induces Gastric Cancer Cell Death via Oncosis and Apoptosis

Directory of Open Access Journals (Sweden)

Dongjun Luo

2016-01-01

Full Text Available Aim. QC4 is the derivative of rosin’s main components dehydroabietic acid (DHA. We investigated the cytotoxic effect of QC4 on gastric cancer cells and revealed the mechanisms beneath the induction of cell death. Methods. The cytotoxic effect of QC4 on gastric cancer cells was evaluated by CCK-8 assay and flow cytometry. The underlying mechanisms were tested by administration of cell death related inhibitors and detection of apoptotic and oncosis related proteins. Cytomembrane integrity and organelles damage were confirmed by lactate dehydrogenase (LDH leakage assay, mitochondrial function test, and cytosolic free Ca2+ concentration detection. Results. QC4 inhibited cell proliferation dose- and time-dependently and destroyed cell membrane integrity, activated calpain-1 autolysis, and induced apoptotic protein cleavage in gastric cancer cells. The detection of decreased ATP and mitochondrial membrane potential, ROS accumulation, and cytosolic free Ca2+ elevation confirmed organelles damage in QC4-treated gastric cancer cells. Conclusions. DHA derivative QC4 induced the damage of cytomembrane and organelles which finally lead to oncosis and apoptosis in gastric cancer cells. Therefore, as a derivative of plant derived small molecule DHA, QC4 might become a promising agent in gastric cancer therapy.

Disruptive environmental chemicals and cellular mechanisms that confer resistance to cell death.

Science.gov (United States)

Narayanan, Kannan Badri; Ali, Manaf; Barclay, Barry J; Cheng, Qiang Shawn; D'Abronzo, Leandro; Dornetshuber-Fleiss, Rita; Ghosh, Paramita M; Gonzalez Guzman, Michael J; Lee, Tae-Jin; Leung, Po Sing; Li, Lin; Luanpitpong, Suidjit; Ratovitski, Edward; Rojanasakul, Yon; Romano, Maria Fiammetta; Romano, Simona; Sinha, Ranjeet K; Yedjou, Clement; Al-Mulla, Fahd; Al-Temaimi, Rabeah; Amedei, Amedeo; Brown, Dustin G; Ryan, Elizabeth P; Colacci, Annamaria; Hamid, Roslida A; Mondello, Chiara; Raju, Jayadev; Salem, Hosni K; Woodrick, Jordan; Scovassi, A Ivana; Singh, Neetu; Vaccari, Monica; Roy, Rabindra; Forte, Stefano; Memeo, Lorenzo; Kim, Seo Yun; Bisson, William H; Lowe, Leroy; Park, Hyun Ho

2015-06-01

Cell death is a process of dying within biological cells that are ceasing to function. This process is essential in regulating organism development, tissue homeostasis, and to eliminate cells in the body that are irreparably damaged. In general, dysfunction in normal cellular death is tightly linked to cancer progression. Specifically, the up-regulation of pro-survival factors, including oncogenic factors and antiapoptotic signaling pathways, and the down-regulation of pro-apoptotic factors, including tumor suppressive factors, confers resistance to cell death in tumor cells, which supports the emergence of a fully immortalized cellular phenotype. This review considers the potential relevance of ubiquitous environmental chemical exposures that have been shown to disrupt key pathways and mechanisms associated with this sort of dysfunction. Specifically, bisphenol A, chlorothalonil, dibutyl phthalate, dichlorvos, lindane, linuron, methoxychlor and oxyfluorfen are discussed as prototypical chemical disruptors; as their effects relate to resistance to cell death, as constituents within environmental mixtures and as potential contributors to environmental carcinogenesis. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

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...

Vitamin D and Death by Sunshine

Directory of Open Access Journals (Sweden)

Rebecca S. Mason

2013-01-01

Full Text Available Exposure to sunlight is the major cause of skin cancer. Ultraviolet radiation (UV from the sun causes damage to DNA by direct absorption and can cause skin cell death. UV also causes production of reactive oxygen species that may interact with DNA to indirectly cause oxidative DNA damage. UV increases accumulation of p53 in skin cells, which upregulates repair genes but promotes death of irreparably damaged cells. A benefit of sunlight is vitamin D, which is formed following exposure of 7-dehydrocholesterol in skin cells to UV. The relatively inert vitamin D is metabolized to various biologically active compounds, including 1,25-dihydroxyvitamin D3. Therapeutic use of vitamin D compounds has proven beneficial in several cancer types, but more recently these compounds have been shown to prevent UV-induced cell death and DNA damage in human skin cells. Here, we discuss the effects of vitamin D compounds in skin cells that have been exposed to UV. Specifically, we examine the various signaling pathways involved in the vitamin D-induced protection of skin cells from UV.

Damaging and protective cell signalling in the untargeted effects of ionizing radiation

International Nuclear Information System (INIS)

Coates, Philip J.; Lorimore, Sally A.; Wright, Eric G.

2004-01-01

The major adverse consequences of radiation exposures are attributed to DNA damage in irradiated cells that has not been correctly restored by metabolic repair processes. However, the dogma that genetic alterations are restricted to directly irradiated cells has been challenged by observations in which effects of ionizing radiation arise in non-irradiated cells. These, so called, untargeted effects are demonstrated in cells that are the descendants of irradiated cells either directly or via media transfer (radiation-induced genomic instability) or in cells that have communicated with irradiated cells (radiation-induced bystander effects). Radiation-induced genomic instability is characterized by a number of delayed responses including chromosomal abnormalities, gene mutations and cell death. Bystander effects include increases or decreases in damage-inducible and stress-related proteins, increases or decreases in reactive oxygen and nitrogen species, cell death or cell proliferation, cell differentiation, radioadaptation, induction of mutations and chromosome aberrations and chromosomal instability. The phenotypic expression of untargeted effects and the potential consequences of these effects in tissues reflect a balance between the type of bystander signals produced and the responses of cell populations to such signals, both of which may be significantly influenced by cell type and genotype. Thus, in addition to targeted effects of damage induced directly in cells by irradiation, a variety of untargeted effects may also make important short-term and long-term contributions to determining overall outcome after radiation exposures

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.

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.

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.

Cobalt oxide nanoparticles aggravate DNA damage and cell death in eggplant via mitochondrial swelling and NO signaling pathway.

Science.gov (United States)

Faisal, Mohammad; Saquib, Quaiser; Alatar, Abdulrahman A; Al-Khedhairy, Abdulaziz A; Ahmed, Mukhtar; Ansari, Sabiha M; Alwathnani, Hend A; Dwivedi, Sourabh; Musarrat, Javed; Praveen, Shelly

2016-03-18

Despite manifold benefits of nanoparticles (NPs), less information on the risks of NPs to human health and environment has been studied. Cobalt oxide nanoparticles (Co3O4-NPs) have been reported to cause toxicity in several organisms. In this study, we have investigated the role of Co3O4-NPs in inducing phytotoxicity, cellular DNA damage and apoptosis in eggplant (Solanum melongena L. cv. Violetta lunga 2). To the best of our knowledge, this is the first report on Co3O4-NPs showing phytotoxicity in eggplant. The data revealed that eggplant seeds treated with Co3O4-NPs for 2 h at a concentration of 1.0 mg/ml retarded root length by 81.5 % upon 7 days incubation in a moist chamber. Ultrastructural analysis by transmission electron microscopy (TEM) demonstrated the uptake and translocation of Co3O4-NPs into the cytoplasm. Intracellular presence of Co3O4-NPs triggered subcellular changes such as degeneration of mitochondrial cristae, abundance of peroxisomes and excessive vacuolization. Flow cytometric analysis of Co3O4-NPs (1.0 mg/ml) treated root protoplasts revealed 157, 282 and 178 % increase in reactive oxygen species (ROS), membrane potential (ΔΨm) and nitric oxide (NO), respectively. Besides, the esterase activity in treated protoplasts was also found compromised. About 2.4-fold greater level of DNA damage, as compared to untreated control was observed in Comet assay, and 73.2 % of Co3O4-NPs treated cells appeared apoptotic in flow cytometry based cell cycle analysis. This study demonstrate the phytotoxic potential of Co3O4-NPs in terms of reduction in seed germination, root growth, greater level of DNA and mitochondrial damage, oxidative stress and cell death in eggplant. The data generated from this study will provide a strong background to draw attention on Co3O4-NPs environmental hazards to vegetable crops.

Difference in cellular damage and cell death in thermal death time disks and high hydrostatic pressure treated Salmonella Enteritidis (ATCC13076) in liquid whole egg

Science.gov (United States)

Differences in membrane damage including leakage of intracellular UV-materials and loss of viability of Salmonella Enteritidis (ATCC13076) in liquid whole egg (LWE) following thermal-death-time (TDT) disk and high hydrostatic pressure treatments were examined. Salmonella enteritidis was inoculated ...

Primary radiation damage and disturbance in cell divisions

International Nuclear Information System (INIS)

Kim, Jin Kyu; Lee, Yun-Jong; Kim, Jae-Hun; Petin, Vladislav G.; Nili, Mohammad

2008-01-01

damage which finally results in cell death. (author)

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.

Autoradiographic studies on the cell kinetics after the whole body X-irradiation. 2. Regularities of the post-irradiation death of differentiating and proliferating cells of the rat brain subependimal zone

International Nuclear Information System (INIS)

Gracheva, N.D.

1982-01-01

A wave-like character of death of proliferating and differentiating (D) cells is shown autoradiographically using 3 H-thymidine introduced 60-80 min before the whole body X-ray irradiation in doses of 50, 150 or 300 R on subependymal cells of rat brain. Lethally damaged cells irradiated in G 2 and S-phases, resulted in 4 peaks of death in mitosis by following the first postradiational mitotic cycle (MC). Lethally damaged cells irradiated in G 1 -phase lost ability for DNA synthesis as cells irradiated in a dose of 300 R did not include additionally introduced (3 hrs before death) 14 C-thymidine from 12 to 17 hrs after 3 H-thymidine injection. However, in the first 4 hrs after irradiation there were no cells irradiated in G 1 -phase among dead ones, as indirec showed the calculations of data obtained tly/ while studying Pliss lymphosarcoma. A supposition is made that the death of cells irradiated in G 1 -phase is attributed to mitotic phase of the first MC after irradiation. Waves of death of lethally damaged D-cells repeated the peaks of death and corresponded to the mitotic peaks of proliferating cells, which permitted to presuppose the presence of ''short cycle'' (SC) in D-cells, which have the rhythm similar to MC and their death has been attributed to the final SC phase, which corresponds to MC mitotic phase in time. According to the peaks of cell death position of one hour block independent of dose in six MC(SC) points is determined. The cells have experienced the block in the point of MC(SC) in subphase of which they were caught by irradiation. Dose effect is manifested in the number of dead cells

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.

Fungicidal Drugs Induce a Common Oxidative-Damage Cellular Death Pathway

Directory of Open Access Journals (Sweden)

Peter Belenky

2013-02-01

Full Text Available Amphotericin, miconazole, and ciclopirox are antifungal agents from three different drug classes that can effectively kill planktonic yeast, yet their complete fungicidal mechanisms are not fully understood. Here, we employ a systems biology approach to identify a common oxidative-damage cellular death pathway triggered by these representative fungicides in Candida albicans and Saccharomyces cerevisiae. This mechanism utilizes a signaling cascade involving the GTPases Ras1 and Ras2 and protein kinase A, and it culminates in death through the production of toxic reactive oxygen species in a tricarboxylic-acid-cycle- and respiratory-chain-dependent manner. We also show that the metabolome of C. albicans is altered by antifungal drug treatment, exhibiting a shift from fermentation to respiration, a jump in the AMP/ATP ratio, and elevated production of sugars; this coincides with elevated mitochondrial activity. Lastly, we demonstrate that DNA damage plays a critical role in antifungal-induced cellular death and that blocking DNA-repair mechanisms potentiates fungicidal activity.

Relationship between radiation damage on biomembranes and the cell killing

International Nuclear Information System (INIS)

Sato, Chikako

1978-01-01

Death of unproliferated mammalian erythrocytes causes an increase of ion permeability as membranous damage after x-ray irradiation and hemolysis, and production of peroxides in membrane and an effect of SH base are thought as the causes. As a mechanism of death of small lymphocytes with high radiosensitivity, the following three assumptions were reported: disorder of ATP synthesis in nucleus and cytoplasms, self-digestion by flowing out of proteinase from lysozyme by membranous disorder, and catalysis of DNA-protein complex. Death of proliferated cells causes loss of colony formation ability, and it was explained by colony method using Escherichia coli and mammalian cells and by dose-survival rate. Changes in membranous structure by cellular electrophoretic degree and the relationship between these changes and inhibition of cellular proliferation were mentioned as problems. (Tsunoda, M.)

Methylglyoxal-bis(guanylhydrazone), a polyamine analogue, sensitized γ-radiation-induced cell death in HL-60 leukemia cells Sensitizing effect of MGBG on γ-radiation-induced cell death.

Science.gov (United States)

Kim, Jin Sik; Lee, Jin; Chung, Hai Won; Choi, Han; Paik, Sang Gi; Kim, In Gyu

2006-09-01

Methylglyoxal-bis(guanylhydrazone) (MGBG), a polyamine analogue, has been known to inhibit the biosynthesis of polyamines, which are important in cell proliferation. We showed that MGBG treatment significantly affected γ-radiation-induced cell cycle transition (G(1)/G(0)→S→G(2)/M) and thus γ-radiation-induced cell death. As determined by micronuclei and comet assay, we showed that it sensitized the cytotoxic effect induced by γ-radiation. One of the reasons is that polyamine depletion by MGBG treatment did not effectively protect against the chemical (OH) or physical damage to DNA caused by γ-radiation. Through in vitro experiment, we confirmed that DNA strand breaks induced by γ-radiation was prevented more effectively in the presence of polyamines (spermine and spermidine) than in the absence of polyamines. MGBG also blocks the cell cycle transition caused by γ-radiation (G(2) arrest), which helps protect cells by allowing time for DNA repair before entry into mitosis or apoptosis, via the down regulation of cyclin D1, which mediates the transition from G(1) to S phase of cell cycle, and ataxia telangiectasia mutated, which is involved in the DNA sensing, repair and cell cycle check point. Therefore, the abrogation of G(2) arrest sensitizes cells to the effect of γ-radiation. As a result, γ-radiation-induced cell death increased by about 2.5-3.0-fold in cells treated with MGBG. However, exogenous spermidine supplement partially relieved this γ-radiation-induced cytotoxicity and cell death. These findings suggest a potentially therapeutic strategy for increasing the cytotoxic efficacy of γ-radiation.

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

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.

Radiobiological Effects of Alpha-Particles from Astatine-211: From DNA Damage to Cell Death

Energy Technology Data Exchange (ETDEWEB)

Claesson, Kristina

2011-05-15

In recent years, the use of high linear energy transfer (LET) radiation for radiotherapeutic applications has gained increased interest. Astatine-211 (211At) is an alpha-particle emitting radionuclide, promising for targeted radioimmunotherapy of isolated tumor cells and microscopic clusters. To improve development of safe radiotherapy using 211At it is important to increase our knowledge of the radiobiological effects in cells. During radiotherapy, both tumors and adjacent normal tissue will be irradiated and therefore, it is of importance to understand differences in the radio response between proliferating and resting cells. The aim of this thesis was to investigate effects in fibroblasts with different proliferation status after irradiation with alpha-particles from 211At or X-rays, from inflicted DNA damage, to cellular responses and biological consequences. Throughout this work, irradiation was performed with alpha-particles from 211A or X-rays. The induction and repair of double-strand breaks (DSBs) in human normal fibroblasts were investigated using pulsed-field gel electrophoresis and fragment analysis. The relative biological effectiveness (RBE) of 211At for DSB induction varied between 1.4 and 3.1. A small increase of DSBs was observed in cycling cells compared to stationary cells. The repair kinetics was slower after 211At and more residual damage was found after 24 h. Comparison between cells with different proliferation status showed that the repair was inefficient in cycling cells with more residual damage, regardless of radiation quality. Activation of cell cycle arrests was investigated using immunofluorescent labeling of the checkpoint kinase Chk2 and by measuring cell cycle distributions with flow cytometry analysis. After alpha-particle irradiation, the average number of Chk2-foci was larger and the cells had a more affected cell cycle progression for several weeks compared with X-irradiated cells, indicating a more powerful arrest after 211At

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

Inhibition of HAS2 induction enhances the radiosensitivity of cancer cells via persistent DNA damage

International Nuclear Information System (INIS)

Shen, Yan Nan; Shin, Hyun-Jin; Joo, Hyun-Yoo; Park, Eun-Ran; Kim, Su-Hyeon; Hwang, Sang-Gu; Park, Sang Jun; Kim, Chun-Ho; Lee, Kee-Ho

2014-01-01

Highlights: •HAS2 may be a promising target for the radiosensitization of human cancer. •HAS2 is elevated (up to ∼10-fold) in irradiated radioresistant and -sensitive cancer cells. •HAS2 knockdown sensitizes cancer cells to radiation. •HAS2 knockdown potentiates irradiation-induced DNA damage and apoptotic death. •Thus, the irradiation-induced up-regulation of HAS2 contributes to the radioresistance of cancer cells. -- Abstract: Hyaluronan synthase 2 (HAS2), a synthetic enzyme for hyaluronan, regulates various aspects of cancer progression, including migration, invasion and angiogenesis. However, the possible association of HAS2 with the response of cancer cells to anticancer radiotherapy, has not yet been elucidated. Here, we show that HAS2 knockdown potentiates irradiation-induced DNA damage and apoptosis in cancer cells. Upon exposure to radiation, all of the tested human cancer cell lines exhibited marked (up to 10-fold) up-regulation of HAS2 within 24 h. Inhibition of HAS2 induction significantly reduced the survival of irradiated radioresistant and -sensitive cells. Interestingly, HAS2 depletion rendered the cells to sustain irradiation-induced DNA damage, thereby leading to an increase of apoptotic death. These findings indicate that HAS2 knockdown sensitizes cancer cells to radiation via persistent DNA damage, further suggesting that the irradiation-induced up-regulation of HAS2 contributes to the radioresistance of cancer cells. Thus, HAS2 could potentially be targeted for therapeutic interventions aimed at radiosensitizing cancer cells

Profound Endothelial Damage Predicts Impending Organ Failure and Death in Sepsis

DEFF Research Database (Denmark)

Johansen, Maria E; Johansson, Pär I.; Ostrowski, Sisse R

2015-01-01

levels at enrollment predicted risk of multiple organ failure during follow-up (HR [> 14 ng/mL vs. organ failure and death in septic......Endothelial damage contributes to organ failure and mortality in sepsis, but the extent of the contribution remains poorly quantified. Here, we examine the association between biomarkers of superficial and profound endothelial damage (syndecan-1 and soluble thrombomodulin [sTM], respectively......), organ failure, and death in sepsis. The data from a clinical trial, including critically ill patients predominantly suffering sepsis (Clinicaltrials.gov: NCT00271752) were studied. Syndecan-1 and sTM levels at the time of study enrollment were determined. The predictive ability of biomarker levels...

Cellular Responses to Cisplatin-Induced DNA Damage

Directory of Open Access Journals (Sweden)

Alakananda Basu

2010-01-01

Full Text Available Cisplatin is one of the most effective anticancer agents widely used in the treatment of solid tumors. It is generally considered as a cytotoxic drug which kills cancer cells by damaging DNA and inhibiting DNA synthesis. How cells respond to cisplatin-induced DNA damage plays a critical role in deciding cisplatin sensitivity. Cisplatin-induced DNA damage activates various signaling pathways to prevent or promote cell death. This paper summarizes our current understandings regarding the mechanisms by which cisplatin induces cell death and the bases of cisplatin resistance. We have discussed various steps, including the entry of cisplatin inside cells, DNA repair, drug detoxification, DNA damage response, and regulation of cisplatin-induced apoptosis by protein kinases. An understanding of how various signaling pathways regulate cisplatin-induced cell death should aid in the development of more effective therapeutic strategies for the treatment of cancer.

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

Ultra-violet B (UVB)-induced skin cell death occurs through a cyclophilin D intrinsic signaling pathway.

Science.gov (United States)

Ji, Chao; Yang, Bo; Yang, Zhi; Tu, Ying; Yang, Yan-li; He, Li; Bi, Zhi-Gang

2012-09-07

UVB-induced skin cell damage involves the opening of mitochondrial permeability transition pore (mPTP), which leads to both apoptotic and necrotic cell death. Cyclophilin D (Cyp-D) translocation to the inner membrane of mitochondrion acts as a key component to open the mPTP. Our Western-Blot results in primary cultured human skin keratinocytes and in HaCaT cell line demonstrated that UVB radiation and hydrogen peroxide (H(2)O(2)) induced Cyp-D expression, which was inhibited by anti-oxidant N-acetyl cysteine (NAC). We created a stable Cyp-D deficiency skin keratinocytes by expressing Cyp-D-shRNA through lentiviral infection. Cyp-D-deficient cells were significantly less susceptible than their counterparts to UVB- or H(2)O(2)-induced cell death. Further, cyclosporine A (Cs-A), a Cyp-D inhibitor, inhibited UVB- or H(2)O(2)-induced keratinocytes cell death. Reversely, over-expression of Cyp-D in primary keratinocytes caused spontaneous keratinocytes cell death. These results suggest Cyp-D's critical role in UVB/oxidative stress-induced skin cell death. Copyright © 2012 Elsevier Inc. All rights reserved.

Combinatorial DNA Damage Pairing Model Based on X-Ray-Induced Foci Predicts the Dose and LET Dependence of Cell Death in Human Breast Cells

Energy Technology Data Exchange (ETDEWEB)

Vadhavkar, Nikhil [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Pham, Christopher [University of Texas, Houston, TX (United States). MD Anderson Cancer Center; Georgescu, Walter [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Life Sciences Div.; Deschamps, Thomas [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Life Sciences Div.; Heuskin, Anne-Catherine [Univ. of Namur (Belgium). Namur Research inst. for Life Sciences (NARILIS), Research Center for the Physics of Matter and Radiation (PMR); Tang, Jonathan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Life Sciences Div.; Costes, Sylvain V. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Life Sciences Div.

2014-09-01

In contrast to the classic view of static DNA double-strand breaks (DSBs) being repaired at the site of damage, we hypothesize that DSBs move and merge with each other over large distances (m). As X-ray dose increases, the probability of having DSB clusters increases as does the probability of misrepair and cell death. Experimental work characterizing the X-ray dose dependence of radiation-induced foci (RIF) in nonmalignant human mammary epithelial cells (MCF10A) is used here to validate a DSB clustering model. We then use the principles of the local effect model (LEM) to predict the yield of DSBs at the submicron level. Two mechanisms for DSB clustering, namely random coalescence of DSBs versus active movement of DSBs into repair domains are compared and tested. Simulations that best predicted both RIF dose dependence and cell survival after X-ray irradiation favored the repair domain hypothesis, suggesting the nucleus is divided into an array of regularly spaced repair domains of ~;;1.55 m sides. Applying the same approach to high-linear energy transfer (LET) ion tracks, we are able to predict experimental RIF/m along tracks with an overall relative error of 12percent, for LET ranging between 30 350 keV/m and for three different ions. Finally, cell death was predicted by assuming an exponential dependence on the total number of DSBs and of all possible combinations of paired DSBs within each simulated RIF. Relative biological effectiveness (RBE) predictions for cell survival of MCF10A exposed to high-LET showed an LET dependence that matches previous experimental results for similar cell types. Overall, this work suggests that microdosimetric properties of ion tracks at the submicron level are sufficient to explain both RIF data and survival curves for any LET, similarly to the LEM assumption. Conversely, high-LET death mechanism does not have to infer linear-quadratic dose formalism as done in the LEM. In addition, the size of repair domains derived in our model

DNA damage and DNA damage response in human bronchial epithelial BEAS-2B cells following exposure to 2-nitrobenzanthrone and 3-nitrobenzanthrone: role in apoptosis.

Science.gov (United States)

Oya, Elisabeth; Ovrevik, Johan; Arlt, Volker M; Nagy, Eszter; Phillips, David H; Holme, Jørn A

2011-11-01

Nitro-polycyclic aromatic hydrocarbons (nitro-PAHs) are mutagenic and carcinogenic environmental pollutants found in diesel exhaust and on urban air pollution particles. In the present study, human bronchial epithelial BEAS-2B cells were exposed to 2-nitrobenzanthrone (2-NBA) and 3-nitrobenzanthrone (3-NBA). DNA damage responses were compared to those observed after exposure to 1-nitropyrene (1-NP) and benzo[a]pyrene (B[a]P). Examination by microscopy revealed that 3-NBA was the most potent toxic compound while weaker responses were observed with 1-NP and B[a]P. Most interestingly, 2-NBA did not induce cell death or any other stress-related responses. 3-NBA induced a typical apoptotic cell death judged by nuclear condensation and little plasma membrane damage as well as cleavage of caspase 3 and poly-(ADP-ribose) polymerase (PARP). Exposure to 3-NBA resulted in an accumulation of cells in S-phase, and further analysis by Western blotting, immunocytochemistry and flow cytometry revealed that 3-NBA induced a DNA damage response characterized by phosphorylation of ATM (ataxia-telangiectasia mutated), checkpoint kinase (Chk) 2/Chk1, H2AX and p53. The p53 inhibitor pifithrin-α inhibited 3-NBA-induced apoptosis while small effects were seen using pifithrin-μ, suggesting that 3-NBA-induced cell death is a result of transcriptional activation of p53. In conclusion, 3-NBA is a potent inducer of apoptosis, which seemed to be triggered by the DNA damage response. Furthermore, a change of the nitro-group to the second position (i.e. 2-NBA) dramatically changed the cellular reactivity of the compound.

Eosinophilic Otitis Media: the Aftermath of Eosinophil Extracellular Trap Cell Death.

Science.gov (United States)

Ueki, Shigeharu; Ohta, Nobuo; Takeda, Masahide; Konno, Yasunori; Hirokawa, Makoto

2017-05-01

Eosinophilic otitis media (EOM) is a refractory disease characterized by the accumulation of eosinophils in middle ear effusion and mucosa. We summarize current knowledge regarding the clinical characteristics and management of EOM. Although eosinophil activation in inflamed foci is involved in the pathogenesis of EOM, little is known about the fate of the eosinophils and aftermath of their cell death. We discuss the possibility that eosinophils undergo non-apoptotic cell death that worsens tissue damage and increases effusion viscosity. Unlike chronic otitis media, EOM is strongly associated with an allergic background. Corticosteroids are currently the only effective pharmacological treatment, and surgical intervention is often required. Mucosal eosinophils infiltrate extensively into the middle ear cavity where they are stimulated by locally produced activators including interleukin-5 and eotaxin. The eosinophils undergo cytolysis in the effusion, which represents a major fate of activated eosinophils in vivo. Recent data revealed cytolysis could be renamed as extracellular trap cell death (ETosis). ETosis represents suicidal cell death involving total cell degranulation and development of sticky chromatin structures (extracellular traps (ETs)). The characteristics of eosinophil- and neutrophil-derived ET polymers might contribute to the difference in viscosity of secretions between EOM and common chronic otitis media. The extracellular products remaining after eosinophil ETosis are an important aspect of EOM pathology. The concept of ETosis also has novel implications for potential therapeutic modalities in various eosinophilic disorders.

PARP-1 cleavage fragments: signatures of cell-death proteases in neurodegeneration

Directory of Open Access Journals (Sweden)

Alexander Jonathan S

2010-12-01

Full Text Available Abstract The normal function of poly (ADP-ribose polymerase-1 (PARP-1 is the routine repair of DNA damage by adding poly (ADP ribose polymers in response to a variety of cellular stresses. Recently, it has become widely appreciated that PARP-1 also participates in diverse physiological and pathological functions from cell survival to several forms of cell death and has been implicated in gene transcription, immune responses, inflammation, learning, memory, synaptic functions, angiogenesis and aging. In the CNS, PARP inhibition attenuates injury in pathologies like cerebral ischemia, trauma and excitotoxicity demonstrating a central role of PARP-1 in these pathologies. PARP-1 is also a preferred substrate for several 'suicidal' proteases and the proteolytic action of suicidal proteases (caspases, calpains, cathepsins, granzymes and matrix metalloproteinases (MMPs on PARP-1 produces several specific proteolytic cleavage fragments with different molecular weights. These PARP-1 signature fragments are recognized biomarkers for specific patterns of protease activity in unique cell death programs. This review focuses on specific suicidal proteases active towards PARP-1 to generate signature PARP-1 fragments that can identify key proteases and particular forms of cell death involved in pathophysiology. The roles played by some of the PARP-1 fragments and their associated binding partners in the control of different forms of cell death are also discussed.

Camptothecin and khat (Catha edulis Forsk. induced distinct cell death phenotypes involving modulation of c-FLIPL, Mcl-1, procaspase-8 and mitochondrial function in acute myeloid leukemia cell lines

Directory of Open Access Journals (Sweden)

Fossan Kjell O

2009-11-01

Full Text Available Abstract Background An organic extract of the recreational herb khat (Catha edulis Forsk. triggers cell death in various leukemia cell lines in vitro. The chemotherapeutics camptothecin, a plant alkaloid topoisomerase I inhibitor, was tested side-by-side with khat in a panel of acute myeloid leukemia cell lines to elucidate mechanisms of toxicity. Results Khat had a profound effect on MOLM-13 cells inducing mitochondrial damage, chromatin margination and morphological features of autophagy. The effects of khat on mitochondrial ultrastructure in MOLM-13 correlated with strongly impaired routine respiration, an effect neither found in the khat-resistant MV-4-11 cells nor in camptothecin treated cells. Enforced expression of anti-apoptotic Bcl-2 protein provided protection against camptothecin-induced cell death and partly against khat toxicity. Khat-induced cell death in MOLM-13 cells included reduced levels of anti-apoptotic Mcl-1 protein, while both khat and camptothecin induced c-FLIPL cleavage and procaspase-8 activation. Conclusion Khat activated a distinct cell death pathway in sensitive leukemic cells as compared to camptothecin, involving mitochondrial damage and morphological features of autophagy. This suggests that khat should be further explored in the search for novel experimental therapeutics.

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.

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.

Critical role of poly(ADP-ribose) polymerase-1 in modulating the mode of cell death caused by continuous oxidative stress.

Science.gov (United States)

Son, Young-Ok; Kook, Sung-Ho; Jang, Yong-Suk; Shi, Xianglin; Lee, Jeong-Chae

2009-11-01

Continuously generated hydrogen peroxide (H(2)O(2)) inhibits typical apoptosis and instead initiates a caspase-independent, apoptosis-inducing factor (AIF)-mediated pyknotic cell death. This may be related to H(2)O(2)-mediated DNA damage and subsequent ATP depletion, although the exact mechanisms by which the mode of cell death is decided after H(2)O(2) exposure are still unclear. Accumulated evidence and our previous data led us to hypothesize that continuously generated H(2)O(2), not an H(2)O(2) bolus, induces severe DNA damage, signaling poly(ADP-ribose) polymerase-1 (PARP-1) activation, ATP depletion, and eventually caspase-independent cell death. Results from the present study support that H(2)O(2) generated continuously by glucose oxidase causes excessive DNA damage and PARP-1 activation. Blockage of PARP-1 by a siRNA transfection or by pharmacological inhibitor resulted in the significant inhibition of ATP depletion, loss of mitochondrial membrane potential, nuclear translocation of AIF and endonuclease G, and eventually conversion to caspase-dependent apoptosis. Overall, the current study demonstrates the different roles of PARP-1 inhibition in modulation of cell death according to the method of H(2)O(2) exposure, that is, continuous generation versus a direct addition. (c) 2009 Wiley-Liss, Inc.

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

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...

Ursodeoxycholic acid suppresses mitochondria-dependent programmed cell death induced by sodium nitroprusside in SH-SY5Y cells

International Nuclear Information System (INIS)

Chun, Hong Sung; Low, Walter C.

2012-01-01

Although ursodeoxycholic acid (UDCA) and its highly water-soluble formula (Yoo's solution; YS) have been shown to prevent neuronal damage, the effects of UDCA or YS against Parkinson's disease (PD)-related dopaminergic cell death has not been studied. This study investigated the protective effects of UDCA and YS on sodium nitroprusside (SNP)-induced cytotoxicity in human dopaminergic SH-SY5Y cells. Both UDCA (50–200 μM) and YS (100–200 μM) dose-dependently prevented SNP (1 mM)-induced cell death. Results showed that both UDCA and YS effectively attenuated the production of total reactive oxygen species (ROS), peroxynitrite (ONOO − ) and nitric oxide (NO), and markedly inhibited the mitochondrial membrane potential (MMP) loss and intracellular reduced glutathione (GSH) depletion. SNP-induced programmed cell death events, such as nuclear fragmentation, caspase-3/7 and -9 activation, Bcl-2/Bax ratio decrease, and cytochrome c release, were significantly attenuated by both UDCA and YS. Furthermore, selective inhibitor of phosphatidylinositiol-3-kinase (PI3K), LY294002, and Akt/PKB inhibitor, triciribine, reversed the preventive effects of UDCA on the SNP-induced cytotoxicity and Bax translocation. These results suggest that UDCA can protect SH-SY5Y cells under programmed cell death process by regulating PI3K-Akt/PKB pathways.

Melatonin pre-treatment mitigates SHSY-5Y cells against oxaliplatin induced mitochondrial stress and apoptotic cell death

Science.gov (United States)

Choudhury, Arnab; Kar, Sudeshna; Tabassum, Heena

2017-01-01

Oxaliplatin (Oxa) treatment to SH-SY5Y human neuroblastoma cells has been shown by previous studies to induce oxidative stress, which in turn modulates intracellular signaling cascades resulting in cell death. While this phenomenon of Oxa-induced neurotoxicity is known, the underlying mechanisms involved in this cell death cascade must be clarified. Moreover, there is still little known regarding the roles of neuronal mitochondria and cytosolic compartments in mediating Oxa-induced neurotoxicity. With a better grasp of the mechanisms driving neurotoxicity in Oxa-treated SH-SY5Y cells, we can then identify certain pathways to target in protecting against neurotoxic cell damage. Therefore, the purpose of this study was to determine whether one such agent, melatonin (Mel), could confer protection against Oxa-induced neurotoxicity in SH-SY5Y cells. Results from the present study found Oxa to significantly reduce SH-SY5Y cell viability in a dose-dependent manner. Alternatively, we found Mel pre-treatment to SH-SY5Y cells to attenuate Oxa-induced toxicity, resulting in a markedly increased cell viability. Mel exerted its protective effects by regulating reactive oxygen species (ROS) production and reducing superoxide radicals inside Oxa-exposed. In addition, we observed pre-treatment with Mel to rescue Oxa-treated cells by protecting mitochondria. As Oxa-treatment alone decreases mitochondrial membrane potential (Δψm), resulting in an altered Bcl-2/Bax ratio and release of sequestered cytochrome c, so Mel was shown to inhibit these pathways. Mel was also found to inhibit proteolytic activation of caspase 3, inactivation of Poly (ADP Ribose) polymerase, and DNA damage, thereby allowing SH-SY5Y cells to resist apoptotic cell death. Collectively, our results suggest a role for melatonin in reducing Oxa induced neurotoxicity. Further studies exploring melatonin’s protective effects may prove successful in eliciting pathways to further alter the neurotoxic pathways of

Melatonin pre-treatment mitigates SHSY-5Y cells against oxaliplatin induced mitochondrial stress and apoptotic cell death.

Directory of Open Access Journals (Sweden)

Mohammad Waseem

Full Text Available Oxaliplatin (Oxa treatment to SH-SY5Y human neuroblastoma cells has been shown by previous studies to induce oxidative stress, which in turn modulates intracellular signaling cascades resulting in cell death. While this phenomenon of Oxa-induced neurotoxicity is known, the underlying mechanisms involved in this cell death cascade must be clarified. Moreover, there is still little known regarding the roles of neuronal mitochondria and cytosolic compartments in mediating Oxa-induced neurotoxicity. With a better grasp of the mechanisms driving neurotoxicity in Oxa-treated SH-SY5Y cells, we can then identify certain pathways to target in protecting against neurotoxic cell damage. Therefore, the purpose of this study was to determine whether one such agent, melatonin (Mel, could confer protection against Oxa-induced neurotoxicity in SH-SY5Y cells. Results from the present study found Oxa to significantly reduce SH-SY5Y cell viability in a dose-dependent manner. Alternatively, we found Mel pre-treatment to SH-SY5Y cells to attenuate Oxa-induced toxicity, resulting in a markedly increased cell viability. Mel exerted its protective effects by regulating reactive oxygen species (ROS production and reducing superoxide radicals inside Oxa-exposed. In addition, we observed pre-treatment with Mel to rescue Oxa-treated cells by protecting mitochondria. As Oxa-treatment alone decreases mitochondrial membrane potential (Δψm, resulting in an altered Bcl-2/Bax ratio and release of sequestered cytochrome c, so Mel was shown to inhibit these pathways. Mel was also found to inhibit proteolytic activation of caspase 3, inactivation of Poly (ADP Ribose polymerase, and DNA damage, thereby allowing SH-SY5Y cells to resist apoptotic cell death. Collectively, our results suggest a role for melatonin in reducing Oxa induced neurotoxicity. Further studies exploring melatonin's protective effects may prove successful in eliciting pathways to further alter the neurotoxic

Systematic Analysis of the Crosstalk between Mitosis and DNA Damage by a Live Cell siRNA Screen

DEFF Research Database (Denmark)

Pedersen, Ronni Sølvhøi

Recent research has shown, that the biological processes of DNA replication, DNA damage, cell cycle and mitosis cannot be considered as isolated cellular functions but are mechanistically linked in many ways. For instance, when cells are exposed to replication stress and enter mitosis...... propose that this strong p53 response, which often occurs without detectable increase in DNA damage, is caused by the acute increase in chromosomal aneuploidy. Finally, our systematic approach to the DNA damage-mitosis crosstalk reveals widespread cell death in response to mitotic pertubations, showing...

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

Mouse embryonic stem cells undergo charontosis, a novel programmed cell death pathway dependent upon cathepsins, p53, and EndoG, in response to etoposide treatment.

Science.gov (United States)

Tichy, Elisia D; Stephan, Zachary A; Osterburg, Andrew; Noel, Greg; Stambrook, Peter J

2013-05-01

Embryonic stem cells (ESCs) are hypersensitive to many DNA damaging agents and can rapidly undergo cell death or cell differentiation following exposure. Treatment of mouse ESCs (mESCs) with etoposide (ETO), a topoisomerase II poison, followed by a recovery period resulted in massive cell death with characteristics of a programmed cell death pathway (PCD). While cell death was both caspase- and necroptosis-independent, it was partially dependent on the activity of lysosomal proteases. A role for autophagy in the cell death process was eliminated, suggesting that ETO induces a novel PCD pathway in mESCs. Inhibition of p53 either as a transcription factor by pifithrin α or in its mitochondrial role by pifithrin μ significantly reduced ESC death levels. Finally, EndoG was newly identified as a protease participating in the DNA fragmentation observed during ETO-induced PCD. We coined the term charontosis after Charon, the ferryman of the dead in Greek mythology, to refer to the PCD signaling events induced by ETO in mESCs. Copyright © 2013 Elsevier B.V. All rights reserved.

Ultra-violet B (UVB)-induced skin cell death occurs through a cyclophilin D intrinsic signaling pathway

International Nuclear Information System (INIS)

Ji, Chao; Yang, Bo; Yang, Zhi; Tu, Ying; Yang, Yan-li; He, Li; Bi, Zhi-Gang

2012-01-01

Highlights: ► UVB radiated skin keratinocytes show cyclophilin D (Cyp-D) upregulation. ► NAC inhibits UVB induced Cyp-D expression, while H 2 O 2 facilitates it. ► Cyp-D-deficient cells are significantly less susceptible to UVB induced cell death. ► Over-expression of Cyp-D causes spontaneous keratinocytes cell death. -- Abstract: UVB-induced skin cell damage involves the opening of mitochondrial permeability transition pore (mPTP), which leads to both apoptotic and necrotic cell death. Cyclophilin D (Cyp-D) translocation to the inner membrane of mitochondrion acts as a key component to open the mPTP. Our Western-Blot results in primary cultured human skin keratinocytes and in HaCaT cell line demonstrated that UVB radiation and hydrogen peroxide (H 2 O 2 ) induced Cyp-D expression, which was inhibited by anti-oxidant N-acetyl cysteine (NAC). We created a stable Cyp-D deficiency skin keratinocytes by expressing Cyp-D-shRNA through lentiviral infection. Cyp-D-deficient cells were significantly less susceptible than their counterparts to UVB- or H 2 O 2 -induced cell death. Further, cyclosporine A (Cs-A), a Cyp-D inhibitor, inhibited UVB- or H 2 O 2 -induced keratinocytes cell death. Reversely, over-expression of Cyp-D in primary keratinocytes caused spontaneous keratinocytes cell death. These results suggest Cyp-D’s critical role in UVB/oxidative stress-induced skin cell death.

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.

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.

AtMMS21, an SMC5/6 complex subunit, is involved in stem cell niche maintenance and DNA damage responses in Arabidopsis roots.

Science.gov (United States)

Xu, Panglian; Yuan, Dongke; Liu, Ming; Li, Chunxin; Liu, Yiyang; Zhang, Shengchun; Yao, Nan; Yang, Chengwei

2013-04-01

Plants maintain stem cells in meristems to sustain lifelong growth; these stem cells must have effective DNA damage responses to prevent mutations that can propagate to large parts of the plant. However, the molecular links between stem cell functions and DNA damage responses remain largely unexplored. Here, we report that the small ubiquitin-related modifier E3 ligase AtMMS21 (for methyl methanesulfonate sensitivity gene21) acts to maintain the root stem cell niche by mediating DNA damage responses in Arabidopsis (Arabidopsis thaliana). Mutation of AtMMS21 causes defects in the root stem cell niche during embryogenesis and postembryonic stages. AtMMS21 is essential for the proper expression of stem cell niche-defining transcription factors. Moreover, mms21-1 mutants are hypersensitive to DNA-damaging agents, have a constitutively increased DNA damage response, and have more DNA double-strand breaks (DSBs) in the roots. Also, mms21-1 mutants exhibit spontaneous cell death within the root stem cell niche, and treatment with DSB-inducing agents increases this cell death, suggesting that AtMMS21 is required to prevent DSB-induced stem cell death. We further show that AtMMS21 functions as a subunit of the STRUCTURAL MAINTENANCE OF CHROMOSOMES5/6 complex, an evolutionarily conserved chromosomal ATPase required for DNA repair. These data reveal that AtMMS21 acts in DSB amelioration and stem cell niche maintenance during Arabidopsis root development.

Enniatin B-induced cell death and inflammatory responses in RAW 267.4 murine macrophages

Energy Technology Data Exchange (ETDEWEB)

Gammelsrud, A. [Norwegian Veterinary Institute, P.O. Box 750, Centrum, N-0106 Oslo (Norway); Department of Air Pollution and Noise, Division of Environmental Medicine, Norwegian Institute of Public Health, N-0403 Oslo (Norway); Solhaug, A. [Norwegian Veterinary Institute, P.O. Box 750, Centrum, N-0106 Oslo (Norway); Dendelé, B. [EA 4427 SeRAIC, IRSET, Université de Rennes 1, IFR 140, Rennes (France); Sandberg, W.J. [Department of Air Pollution and Noise, Division of Environmental Medicine, Norwegian Institute of Public Health, N-0403 Oslo (Norway); Ivanova, L. [Norwegian Veterinary Institute, P.O. Box 750, Centrum, N-0106 Oslo (Norway); Kocbach Bølling, A. [Department of Air Pollution and Noise, Division of Environmental Medicine, Norwegian Institute of Public Health, N-0403 Oslo (Norway); Lagadic-Gossmann, D. [EA 4427 SeRAIC, IRSET, Université de Rennes 1, IFR 140, Rennes (France); Refsnes, M.; Becher, R. [Department of Air Pollution and Noise, Division of Environmental Medicine, Norwegian Institute of Public Health, N-0403 Oslo (Norway); Eriksen, G. [Norwegian Veterinary Institute, P.O. Box 750, Centrum, N-0106 Oslo (Norway); Holme, J.A., E-mail: jorn.holme@fhi.no [Department of Air Pollution and Noise, Division of Environmental Medicine, Norwegian Institute of Public Health, N-0403 Oslo (Norway)

2012-05-15

The mycotoxin enniatin B (EnnB) is predominantly produced by species of the Fusarium genera, and often found in grain. The cytotoxic effect of EnnB has been suggested to be related to its ability to form ionophores in cell membranes. The present study examines the effects of EnnB on cell death, differentiation, proliferation and pro-inflammatory responses in the murine monocyte–macrophage cell line RAW 264.7. Exposure to EnnB for 24 h caused an accumulation of cells in the G0/G1-phase with a corresponding decrease in cyclin D1. This cell cycle-arrest was possibly also linked to the reduced cellular ability to capture and internalize receptors as illustrated by the lipid marker ganglioside GM1. EnnB also increased the number of apoptotic, early apoptotic and necrotic cells, as well as cells with elongated spindle-like morphology. The Neutral Red assay indicated that EnnB induced lysosomal damage; supported by transmission electron microscopy (TEM) showing accumulation of lipids inside the lysosomes forming lamellar structures/myelin bodies. Enhanced levels of activated caspase-1 were observed after EnnB exposure and the caspase-1 specific inhibitor ZYVAD-FMK reduced EnnB-induced apoptosis. Moreover, EnnB increased the release of interleukin-1beta (IL-1β) in cells primed with lipopolysaccharide (LPS), and this response was reduced by both ZYVAD-FMK and the cathepsin B inhibitor CA-074Me. In conclusion, EnnB was found to induce cell cycle arrest, cell death and inflammation. Caspase-1 appeared to be involved in the apoptosis and release of IL-1β and possibly activation of the inflammasome through lysosomal damage and leakage of cathepsin B. -- Highlights: ► The mycotoxin EnnB induced cell cycle arrest, cell death and inflammation. ► The G0/G1-arrest was linked to a reduced ability to internalize receptors. ► EnnB caused lysosomal damage, leakage of cathepsin B and caspase-1 cleavage. ► Caspase-1 was partly involved in both apoptosis and release of IL-1�

Enniatin B-induced cell death and inflammatory responses in RAW 267.4 murine macrophages

International Nuclear Information System (INIS)

Gammelsrud, A.; Solhaug, A.; Dendelé, B.; Sandberg, W.J.; Ivanova, L.; Kocbach Bølling, A.; Lagadic-Gossmann, D.; Refsnes, M.; Becher, R.; Eriksen, G.; Holme, J.A.

2012-01-01

The mycotoxin enniatin B (EnnB) is predominantly produced by species of the Fusarium genera, and often found in grain. The cytotoxic effect of EnnB has been suggested to be related to its ability to form ionophores in cell membranes. The present study examines the effects of EnnB on cell death, differentiation, proliferation and pro-inflammatory responses in the murine monocyte–macrophage cell line RAW 264.7. Exposure to EnnB for 24 h caused an accumulation of cells in the G0/G1-phase with a corresponding decrease in cyclin D1. This cell cycle-arrest was possibly also linked to the reduced cellular ability to capture and internalize receptors as illustrated by the lipid marker ganglioside GM1. EnnB also increased the number of apoptotic, early apoptotic and necrotic cells, as well as cells with elongated spindle-like morphology. The Neutral Red assay indicated that EnnB induced lysosomal damage; supported by transmission electron microscopy (TEM) showing accumulation of lipids inside the lysosomes forming lamellar structures/myelin bodies. Enhanced levels of activated caspase-1 were observed after EnnB exposure and the caspase-1 specific inhibitor ZYVAD-FMK reduced EnnB-induced apoptosis. Moreover, EnnB increased the release of interleukin-1beta (IL-1β) in cells primed with lipopolysaccharide (LPS), and this response was reduced by both ZYVAD-FMK and the cathepsin B inhibitor CA-074Me. In conclusion, EnnB was found to induce cell cycle arrest, cell death and inflammation. Caspase-1 appeared to be involved in the apoptosis and release of IL-1β and possibly activation of the inflammasome through lysosomal damage and leakage of cathepsin B. -- Highlights: ► The mycotoxin EnnB induced cell cycle arrest, cell death and inflammation. ► The G0/G1-arrest was linked to a reduced ability to internalize receptors. ► EnnB caused lysosomal damage, leakage of cathepsin B and caspase-1 cleavage. ► Caspase-1 was partly involved in both apoptosis and release of IL-1�

Tributyltin chloride induced testicular toxicity by JNK and p38 activation, redox imbalance and cell death in sertoli-germ cell co-culture.

Science.gov (United States)

Mitra, Sumonto; Srivastava, Ankit; Khandelwal, Shashi

2013-12-06

The widespread use of tributyltin (TBT) as biocides in antifouling paints and agricultural chemicals has led to environmental and marine pollution. Human exposure occurs mainly through TBT contaminated seafood and drinking water. It is a well known endocrine disruptor in mammals, but its molecular mechanism in testicular damage is largely unexplored. This study was therefore, designed to ascertain effects of tributyltin chloride (TBTC) on sertoli-germ cell co-culture in ex-vivo and in the testicular tissue in-vivo conditions. An initial Ca(2+) rise followed by ROS generation and glutathione depletion resulted in oxidative damage and cell death. We observed p38 and JNK phosphorylation, stress proteins (Nrf2, MT and GST) induction and mitochondrial depolarization leading to caspase-3 activation. Prevention of TBTC reduced cell survival and cell death by Ca(2+) inhibitors and free radical scavengers specify definitive role of Ca(2+) and ROS. Sertoli cells were found to be more severely affected which in turn can hamper germ cells functionality. TBTC exposure in-vivo resulted in increased tin content in the testis with enhanced Evans blue leakage into the testicular tissue indicating blood-testis barrier disruption. Tesmin levels were significantly diminished and histopathological studies revealed marked tissue damage. Our data collectively indicates the toxic manifestations of TBTC on the male reproductive system and the mechanisms involved. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Benzyl isothiocyanate alters the gene expression with cell cycle regulation and cell death in human brain glioblastoma GBM 8401 cells.

Science.gov (United States)

Tang, Nou-Ying; Chueh, Fu-Shin; Yu, Chien-Chih; Liao, Ching-Lung; Lin, Jen-Jyh; Hsia, Te-Chun; Wu, King-Chuen; Liu, Hsin-Chung; Lu, Kung-Wen; Chung, Jing-Gung

2016-04-01

Glioblastoma multiforme (GBM) is a highly malignant devastating brain tumor in adults. Benzyl isothiocyanate (BITC) is one of the isothiocyanates that have been shown to induce human cancer cell apoptosis and cell cycle arrest. Herein, the effect of BITC on cell viability and apoptotic cell death and the genetic levels of human brain glioblastoma GBM 8401 cells in vitro were investigated. We found that BITC induced cell morphological changes, decreased cell viability and the induction of cell apoptosis in GBM 8401 cells was time-dependent. cDNA microarray was used to examine the effects of BITC on GBM 8401 cells and we found that numerous genes associated with cell death and cell cycle regulation in GBM 8401 cells were altered after BITC treatment. The results show that expression of 317 genes was upregulated, and two genes were associated with DNA damage, the DNA-damage-inducible transcript 3 (DDIT3) was increased 3.66-fold and the growth arrest and DNA-damage-inducible α (GADD45A) was increased 2.34-fold. We also found that expression of 182 genes was downregulated and two genes were associated with receptor for cell responses to stimuli, the EGF containing fibulin-like extracellular matrix protein 1 (EFEMP1) was inhibited 2.01-fold and the TNF receptor-associated protein 1 (TRAP1) was inhibited 2.08-fold. BITC inhibited seven mitochondria ribosomal genes, the mitochondrial ribosomal protein; tumor protein D52 (MRPS28) was inhibited 2.06-fold, the mitochondria ribosomal protein S2 (MRPS2) decreased 2.07-fold, the mitochondria ribosomal protein L23 (MRPL23) decreased 2.08-fold, the mitochondria ribosomal protein S2 (MRPS2) decreased 2.07-fold, the mitochondria ribosomal protein S12 (MRPS12) decreased 2.08-fold, the mitochondria ribosomal protein L12 (MRPL12) decreased 2.25-fold and the mitochondria ribosomal protein S34 (MRPS34) was decreased 2.30-fold in GBM 8401 cells. These changes of gene expression can provide the effects of BITC on the genetic level and are

3-Nitrobenzanthrone and 3-aminobenzanthrone induce DNA damage and cell signalling in Hepa1c1c7 cells.

Science.gov (United States)

Landvik, N E; Arlt, V M; Nagy, E; Solhaug, A; Tekpli, X; Schmeiser, H H; Refsnes, M; Phillips, D H; Lagadic-Gossmann, D; Holme, J A

2010-02-03

3-Nitrobenzanthrone (3-NBA) is a mutagenic and carcinogenic environmental pollutant found in diesel exhaust and urban air pollution. In the present work we have characterised the effects of 3-NBA and its metabolite 3-aminobenzanthrone (3-ABA) on cell death and cytokine release in mouse hepatoma Hepa1c1c7 cells. These effects were related to induced DNA damage and changes in cell signalling pathways. 3-NBA resulted in cell death and caused most DNA damage as judged by the amount of DNA adducts ((32)P-postlabelling assay), single strand (ss)DNA breaks and oxidative DNA lesions (comet assay) detected. An increased phosphorylation of H2AX, chk1, chk2 and partly ATM was observed using flow cytometry and/or Western blotting. Both compounds increased phosphorylation of p53 and MAPKs (ERK, p38 and JNK). However, only 3-NBA caused an accumulation of p53 in the nucleus and a translocation of Bax to the mitochondria. The p53 inhibitor pifithrin-alpha inhibited 3-NBA-induced apoptosis, indicating that cell death was a result of the triggering of DNA signalling pathways. The highest phosphorylation of Akt and degradation of IkappaB-alpha (suggesting activation of NF-kappaB) were also seen after treatment with 3-NBA. In contrast 3-ABA increased IL-6 release, but caused little or no toxicity. Cytokine release was inhibited by PD98059 and curcumin, suggesting that ERK and NF-kappaB play a role in this process. In conclusion, 3-NBA seems to have a higher potency to induce DNA damage compatible with its cytotoxic effects, while 3-ABA seems to have a greater effect on the immune system. Copyright 2009 Elsevier B.V. All rights reserved.

3-Nitrobenzanthrone and 3-aminobenzanthrone induce DNA damage and cell signalling in Hepa1c1c7 cells

Energy Technology Data Exchange (ETDEWEB)

Landvik, N.E. [Division of Environmental Medicine, Norwegian Institute of Public Health, P.O. Box 404 Torshov N-4303 Oslo (Norway); Arlt, V.M.; Nagy, E. [Section of Molecular Carcinogenesis, Institute of Cancer Research, Brookes Lawley Building, Sutton, Surrey SM2 5NG (United Kingdom); Solhaug, A. [Section for Toxicology, Department of Feed and Food Safety, National Veterinary Institute Pb 750 Sentrum, N-0106 Oslo (Norway); Tekpli, X. [EA SeRAIC, Equipe labellisee Ligue contre le Cancer, IFR 140, Universite de Rennes 1, Rennes (France); Schmeiser, H.H. [Research Group Genetic Alteration in Carcinogenesis, German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Refsnes, M. [Division of Environmental Medicine, Norwegian Institute of Public Health, P.O. Box 404 Torshov N-4303 Oslo (Norway); Phillips, D.H. [Section of Molecular Carcinogenesis, Institute of Cancer Research, Brookes Lawley Building, Sutton, Surrey SM2 5NG (United Kingdom); Lagadic-Gossmann, D. [EA SeRAIC, Equipe labellisee Ligue contre le Cancer, IFR 140, Universite de Rennes 1, Rennes (France); Holme, J.A., E-mail: jorn.holme@fhi.no [Division of Environmental Medicine, Norwegian Institute of Public Health, P.O. Box 404 Torshov N-4303 Oslo (Norway)

2010-02-03

3-Nitrobenzanthrone (3-NBA) is a mutagenic and carcinogenic environmental pollutant found in diesel exhaust and urban air pollution. In the present work we have characterised the effects of 3-NBA and its metabolite 3-aminobenzanthrone (3-ABA) on cell death and cytokine release in mouse hepatoma Hepa1c1c7 cells. These effects were related to induced DNA damage and changes in cell signalling pathways. 3-NBA resulted in cell death and caused most DNA damage as judged by the amount of DNA adducts ({sup 32}P-postlabelling assay), single strand (ss)DNA breaks and oxidative DNA lesions (comet assay) detected. An increased phosphorylation of H2AX, chk1, chk2 and partly ATM was observed using flow cytometry and/or Western blotting. Both compounds increased phosphorylation of p53 and MAPKs (ERK, p38 and JNK). However, only 3-NBA caused an accumulation of p53 in the nucleus and a translocation of Bax to the mitochondria. The p53 inhibitor pifithrin-alpha inhibited 3-NBA-induced apoptosis, indicating that cell death was a result of the triggering of DNA signalling pathways. The highest phosphorylation of Akt and degradation of I{kappa}B-{alpha} (suggesting activation of NF-{kappa}B) were also seen after treatment with 3-NBA. In contrast 3-ABA increased IL-6 release, but caused little or no toxicity. Cytokine release was inhibited by PD98059 and curcumin, suggesting that ERK and NF-{kappa}B play a role in this process. In conclusion, 3-NBA seems to have a higher potency to induce DNA damage compatible with its cytotoxic effects, while 3-ABA seems to have a greater effect on the immune system.

Causes and Consequences of Sensory Hair Cell Damage and Recovery in Fishes.

Science.gov (United States)

Smith, Michael E; Monroe, J David

2016-01-01

Sensory hair cells are the mechanotransductive receptors that detect gravity, sound, and vibration in all vertebrates. Damage to these sensitive receptors often results in deficits in vestibular function and hearing. There are currently two main reasons for studying the process of hair cell loss in fishes. First, fishes, like other non-mammalian vertebrates, have the ability to regenerate hair cells that have been damaged or lost via exposure to ototoxic chemicals or acoustic overstimulation. Thus, they are used as a biomedical model to understand the process of hair cell death and regeneration and find therapeutics that treat or prevent human hearing loss. Secondly, scientists and governmental natural resource managers are concerned about the potential effects of intense anthropogenic sounds on aquatic organisms, including fishes. Dr. Arthur N. Popper and his students, postdocs and research associates have performed pioneering experiments in both of these lines of fish hearing research. This review will discuss the current knowledge regarding the causes and consequences of both lateral line and inner ear hair cell damage in teleost fishes.

The novel anthraquinone derivative IMP1338 induces death of human cancer cells by p53-independent S and G2/M cell cycle arrest.

Science.gov (United States)

Choi, Hyun Kyung; Ryu, Hwani; Son, A-Rang; Seo, Bitna; Hwang, Sang-Gu; Song, Jie-Young; Ahn, Jiyeon

2016-04-01

To identify novel small molecules that induce selective cancer cell death, we screened a chemical library containing 1040 compounds in HT29 colon cancer and CCD18-Co normal colon cells, using a phenotypic cell-based viability assay system with the Cell Counting Kit-8 (CCK-8). We discovered a novel anthraquinone derivative, N-(4-[{(9,10-dioxo-9,10-dihydro-1-anthracenyl)sulfonyl}amino]phenyl)-N-methylacetamide (IMP1338), which was cytotoxic against the human colon cancer cells tested. The MTT cell viability assay showed that treatment with IMP1338 selectively inhibited HCT116, HCT116 p53(-/-), HT29, and A549 cancer cell proliferation compared to that of Beas2B normal epithelial cells. To elucidate the cellular mechanism underlying the cytotoxicity of IMP1338, we examined the effect of IMP1338 on the cell cycle distribution and death of cancer cells. IMP1338 treatment significantly arrested the cell cycle at S and G2/M phases by DNA damage and led to apoptotic cell death, which was determined using FACS analysis with Annexin V/PI double staining. Furthermore, IMP1338 increased caspase-3 cleavage in wild-type p53, p53 knockout HCT116, and HT29 cells as determined using immunoblotting. In addition, IMP1338 markedly induced the phosphorylation of histone H2AX and Chk1 in both cell lines while the combination of 5-fluorouracil (5-FU) and radiation inhibited the viability of HCT116, HCT116 p53(-/-), and HT29 cells compared to 5-FU or radiation alone. Our findings indicated that IMP1338 induced p53-independent cell death through S and G2/M phase arrest as well as DNA damage. These results provide a basis for future investigations assessing the promising anticancer properties of IMP1338. Copyright © 2016. Published by Elsevier Masson SAS.

Edaravone, an ROS Scavenger, Ameliorates Photoreceptor Cell Death after Experimental Retinal Detachment

Science.gov (United States)

Roh, Mi In; Murakami, Yusuke; Thanos, Aristomenis; Miller, Joan W.

2011-01-01

Purpose. To investigate whether edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one), a free radical scavenger, would be neuroprotective against photoreceptor cell death in a rat model of retinal detachment (RD). Methods. RD was induced in adult Brown Norway rats by subretinal injection of sodium hyaluronate. Edaravone (3, 5, or 10 mg/kg) or physiologic saline was administered intraperitoneally once a day until death on day 3 or 5. Oxidative stress in the retina was assessed by 4-hydroxynonenal staining or ELISA for protein carbonyl content. Photoreceptor death was assessed by TUNEL and measurement of the outer nuclear layer thickness. Western blot analysis and caspase activity assays were performed. Inflammatory cytokine secretion and inflammatory cell infiltration were evaluated by ELISA and immunostaining, respectively. Results. RD resulted in increased generation of ROS. Treatment with 5 mg/kg edaravone significantly reduced the ROS level, along with a decrease in TUNEL-positive cells in the photoreceptor layer. A caspase assay also confirmed decreased activation of caspase-3, -8, and -9 in RD treated with edaravone. The level of the antiapoptotic Bcl-2 was increased in detached retinas after edaravone treatment, whereas the levels of the stress-activated p-ERK1/2 were decreased. In addition, edaravone treatment resulted in a significant decrease in the levels of TNF-α, MCP-1, and macrophage infiltration. Conclusions. Oxidative stress plays an important role in photoreceptor cell death after RD. Edaravone treatment may aid in preventing photoreceptor cell death after RD by suppressing ROS-induced photoreceptor damage. PMID:21310909

NADPH oxidase-mediated generation of reactive oxygen species: A new mechanism for X-ray-induced HeLa cell death

International Nuclear Information System (INIS)

Liu Qing; He Xiaoqing; Liu Yongsheng; Du Bingbing; Wang Xiaoyan; Zhang Weisheng; Jia Pengfei; Dong Jingmei; Ma Jianxiu; Wang Xiaohu; Li Sha; Zhang Hong

2008-01-01

Oxidative damage is an important mechanism in X-ray-induced cell death. Radiolysis of water molecules is a source of reactive oxygen species (ROS) that contribute to X-ray-induced cell death. In this study, we showed by ROS detection and a cell survival assay that NADPH oxidase has a very important role in X-ray-induced cell death. Under X-ray irradiation, the upregulation of the expression of NADPH oxidase membrane subunit gp91 phox was dose-dependent. Meanwhile, the cytoplasmic subunit p47 phox was translocated to the cell membrane and localized with p22 phox and gp91 phox to form reactive NADPH oxidase. Our data suggest, for the first time, that NADPH oxidase-mediated generation of ROS is an important contributor to X-ray-induced cell death. This suggests a new target for combined gene transfer and radiotherapy.

Ultra-violet B (UVB)-induced skin cell death occurs through a cyclophilin D intrinsic signaling pathway

Energy Technology Data Exchange (ETDEWEB)

Ji, Chao [Department of Dermatology, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210024, Jiangsu (China); Yang, Bo [Department of Dermatology, Huashan Hospital, Fudan University, Shanghai 200040 (China); Yang, Zhi; Tu, Ying [Department of Dermatology, The First Affiliated Hospital of Kunming Medical University, Yunnan Provincial Institute of Dermatology, Kunming 650032, Yunnan (China); Yang, Yan-li [Department of Otorhinolaryngology, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210024, Jiangsu (China); He, Li, E-mail: heli2662@yahoo.com.cn [Department of Otorhinolaryngology, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210024, Jiangsu (China); Bi, Zhi-Gang, E-mail: eltonbibenqhospital@yahoo.com.cn [Department of Dermatology, BenQ Medical Center, Nanjing Medical University, Nanjing 210019, Jiangsu (China)

2012-09-07

Highlights: Black-Right-Pointing-Pointer UVB radiated skin keratinocytes show cyclophilin D (Cyp-D) upregulation. Black-Right-Pointing-Pointer NAC inhibits UVB induced Cyp-D expression, while H{sub 2}O{sub 2} facilitates it. Black-Right-Pointing-Pointer Cyp-D-deficient cells are significantly less susceptible to UVB induced cell death. Black-Right-Pointing-Pointer Over-expression of Cyp-D causes spontaneous keratinocytes cell death. -- Abstract: UVB-induced skin cell damage involves the opening of mitochondrial permeability transition pore (mPTP), which leads to both apoptotic and necrotic cell death. Cyclophilin D (Cyp-D) translocation to the inner membrane of mitochondrion acts as a key component to open the mPTP. Our Western-Blot results in primary cultured human skin keratinocytes and in HaCaT cell line demonstrated that UVB radiation and hydrogen peroxide (H{sub 2}O{sub 2}) induced Cyp-D expression, which was inhibited by anti-oxidant N-acetyl cysteine (NAC). We created a stable Cyp-D deficiency skin keratinocytes by expressing Cyp-D-shRNA through lentiviral infection. Cyp-D-deficient cells were significantly less susceptible than their counterparts to UVB- or H{sub 2}O{sub 2}-induced cell death. Further, cyclosporine A (Cs-A), a Cyp-D inhibitor, inhibited UVB- or H{sub 2}O{sub 2}-induced keratinocytes cell death. Reversely, over-expression of Cyp-D in primary keratinocytes caused spontaneous keratinocytes cell death. These results suggest Cyp-D's critical role in UVB/oxidative stress-induced skin cell death.

Parainfluenza Virus Infection Sensitizes Cancer Cells to DNA-Damaging Agents: Implications for Oncolytic Virus Therapy.

Science.gov (United States)

Fox, Candace R; Parks, Griffith D

2018-04-01

A parainfluenza virus 5 (PIV5) with mutations in the P/V gene (P/V-CPI - ) is restricted for spread in normal cells but not in cancer cells in vitro and is effective at reducing tumor burdens in mouse model systems. Here we show that P/V-CPI - infection of HEp-2 human laryngeal cancer cells results in the majority of the cells dying, but unexpectedly, over time, there is an emergence of a population of cells that survive as P/V-CPI - persistently infected (PI) cells. P/V-CPI - PI cells had elevated levels of basal caspase activation, and viability was highly dependent on the activity of cellular inhibitor-of-apoptosis proteins (IAPs) such as Survivin and XIAP. In challenge experiments with external inducers of apoptosis, PI cells were more sensitive to cisplatin-induced DNA damage and cell death. This increased cisplatin sensitivity correlated with defects in DNA damage signaling pathways such as phosphorylation of Chk1 and translocation of damage-specific DNA binding protein 1 (DDB1) to the nucleus. Cisplatin-induced killing of PI cells was sensitive to the inhibition of wild-type (WT) p53-inducible protein 1 (WIP1), a phosphatase which acts to terminate DNA damage signaling pathways. A similar sensitivity to cisplatin was seen with cells during acute infection with P/V-CPI - as well as during acute infections with WT PIV5 and the related virus human parainfluenza virus type 2 (hPIV2). Our results have general implications for the design of safer paramyxovirus-based vectors that cannot establish PI as well as the potential for combining chemotherapy with oncolytic RNA virus vectors. IMPORTANCE There is intense interest in developing oncolytic viral vectors with increased potency against cancer cells, particularly those cancer cells that have gained resistance to chemotherapies. We have found that infection with cytoplasmically replicating parainfluenza virus can result in increases in the killing of cancer cells by agents that induce DNA damage, and this is linked

Induction of cancer cell death by proton beam in tumor hypoxic region

International Nuclear Information System (INIS)

Lee, Y. M.; Heo, T. R.; Lee, K. B.; Jang, K. H.; Kim, H. N.; Lee, S. H.; Jeong, M. H.

2008-04-01

Proton beam has been applied to treat various tumor patients in clinical studies. However, it is still undefined whether proton radiation can inhibit the blood vessel formation and induce the cell death in vascular endothelial cells in growing organs. The aim of this study are first, to develop an optimal animal model for the observation of blood vessel development with low dose of proton beam and second, to investigate the effect of low dose proton beam on the inhibition of blood vessel formation induced by hypoxic conditions. In this study, flk1-GFP transgenic zebrafish embryos were used to directly visualize and determine the inhibition of blood vessels by low dose (1, 2, 5 Gy) of proton beam with spread out Bragg peak (SOBP). And we observed cell death by acridine orange staining at 96 hours post fertilization (hpf) stage of embryos after proton irradiation. We also compared the effects of proton beam with those of gamma-ray. An antioxidant, N-acetyl cystein (NAC) was used to investigate whether reactive oxygen species (ROS) were involved in the cell deaths induced by proton irradiation. Irradiated flk-1-GFP transgenic embryos with proton beam irradiation (35 MeV, spread out Bragg peak, SOBP) demonstrated a marked inhibition of embryonic growth and an altered fluorescent blood vessel development in the trunk region. When the cells with DNA damage in the irradiated zebrafish were stained with acridine orange, green fluorescent cell death spots were increased in trunk regions compared to non-irradiated control embryos. Proton beam also significantly increased the cell death rate in human umbilical vein endothelial cells (HUVEC), but pretreatment of N-acetyl cystein (NAC), an antioxidant, recovered the proton-induced cell death rate (p<0.01). Moreover, pretreatment of NAC abrogated the effect of proton beam on the inhibition of trunk vessel development and malformation of trunk truncation. From this study, we found that proton radiation therapy can inhibit the

Ochratoxin A: induction of (oxidative) DNA damage, cytotoxicity and apoptosis in mammalian cell lines and primary cells

International Nuclear Information System (INIS)

Kamp, Hennicke G.; Eisenbrand, Gerhard; Schlatter, Josef; Wuerth, Kirsten; Janzowski, Christine

2005-01-01

Ochratoxin A (OTA) is a nephrotoxic/-carcinogenic mycotoxin, produced by several Aspergillus- and Penicillium-strains. Humans are exposed to OTA via food contamination, a causal relationship of OTA to human endemic Balkan nephropathy is still under debate. Since DNA-adducts of OTA or its metabolites could not be identified unambiguously, its carcinogenic effectiveness might be related to secondary effects, such as oxidative cell damage or cell proliferation. In this study, OTA mediated induction of (oxidative) DNA damage, cytotoxicity (necrosis, growth inhibition, apoptosis) and modulation of glutathione were investigated in cell lines (V79, CV-1) and primary rat kidney cells. After 24 h incubation, viability of V79 cells was strongly decreased by OTA concentrations >2.5 μmol/L, whereas CV-1 cells were clearly less sensitive. Strong growth inhibition occurred in both cell lines (IC 50 ∼2 μmol/L). Apoptosis, detected with an immunochemical test and with flow cytometry, was induced by >1 μmol/L OTA. Oxidative DNA damage, detected by comet assay after additional treatment with repair enzymes, was induced in all cell systems already at five-fold lower concentrations. Glutathione in CV-1 cells was depleted after 1 h incubation (>100 μmol/L). In contrast, an increase was measured after 24 h incubation (>0.5 μmol/L). In conclusion, OTA induces oxidative DNA damage at low, not yet cytotoxic concentrations. Oxidative DNA damage might initiate cell transformation eventually in connection with proliferative response following cytotoxic cell death. Both events might represent pivotal factors in the chain of cellular events leading into nephro-carcinogenicity of OTA

Apoptosis-like death, an extreme SOS response in Escherichia coli.

Science.gov (United States)

Erental, Ariel; Kalderon, Ziva; Saada, Ann; Smith, Yoav; Engelberg-Kulka, Hanna

2014-07-15

In bacteria, SOS is a global response to DNA damage, mediated by the recA-lexA genes, resulting in cell cycle arrest, DNA repair, and mutagenesis. Previously, we reported that Escherichia coli responds to DNA damage via another recA-lexA-mediated pathway resulting in programmed cell death (PCD). We called it apoptosis-like death (ALD) because it is characterized by membrane depolarization and DNA fragmentation, which are hallmarks of eukaryotic mitochondrial apoptosis. Here, we show that ALD is an extreme SOS response that occurs only under conditions of severe DNA damage. Furthermore, we found that ALD is characterized by additional hallmarks of eukaryotic mitochondrial apoptosis, including (i) rRNA degradation by the endoribonuclease YbeY, (ii) upregulation of a unique set of genes that we called extensive-damage-induced (Edin) genes, (iii) a decrease in the activities of complexes I and II of the electron transport chain, and (iv) the formation of high levels of OH˙ through the Fenton reaction, eventually resulting in cell death. Our genetic and molecular studies on ALD provide additional insight for the evolution of mitochondria and the apoptotic pathway in eukaryotes. Importance: The SOS response is the first described and the most studied bacterial response to DNA damage. It is mediated by a set of two genes, recA-lexA, and it results in DNA repair and thereby in the survival of the bacterial culture. We have shown that Escherichia coli responds to DNA damage by an additional recA-lexA-mediated pathway resulting in an apoptosis-like death (ALD). Apoptosis is a mode of cell death that has previously been reported only in eukaryotes. We found that E. coli ALD is characterized by several hallmarks of eukaryotic mitochondrial apoptosis. Altogether, our results revealed that recA-lexA is a DNA damage response coordinator that permits two opposite responses: life, mediated by the SOS, and death, mediated by the ALD. The choice seems to be a function of the degree

[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.

Recent Insights in Islet Amyloid Polypeptide-Induced Membrane Disruption and Its Role in β-Cell Death in Type 2 Diabetes Mellitus

Directory of Open Access Journals (Sweden)

Lucie Khemtémourian

2008-01-01

Full Text Available The presence of fibrillar protein deposits (amyloid of human islet amyloid polypeptide (hIAPP in the pancreatic islets of Langerhans is thought to be related to death of the insulin-producing islet β-cells in type 2 diabetes mellitus (DM2. The mechanism of hIAPP-induced β-cell death is not understood. However, there is growing evidence that hIAPP-induced disruption of β-cell membranes is the cause of hIAPP cytotoxicity. Amyloid cytotoxicity by membrane damage has not only been suggested for hIAPP, but also for peptides and proteins related to other misfolding diseases, like Alzheimer’s disease, Parkinson’s disease, and prion diseases. Here we review the interaction of hIAPP with membranes, and discuss recent progress in the field, with a focus on hIAPP structure and on the proposed mechanisms of hIAPP-induced membrane damage in relation to β-cell death in DM2.

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.

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.

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.

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.

Reproductive-phase and interphase lethal cell damage after irradiation and treatment with cytostatics

International Nuclear Information System (INIS)

Hagemann, G.

1979-01-01

After X-ray irradiation of manual cells, two lethal fractions occur due to reproductive and interphase death under low and high radiation doses. The damage kinetics on which this fact is based is compared with hypothetical tumour frequencies and leucemia induction caused in experiments. The reproductive-lethal damage can be manifested by means of colony size spectrometry, with the median colony size class differences (MCD) serving as measure for the damage found. The simultaneous effects of the cytostatics BLEOMYCIN or ICRF 159 and X-rays on reproductive lethal and interphase-lethal damage are measured by means of MCD and survival fraction, and the additive and intensifying effect' is judged with the help of suitably defined terms. This shows that the clinically used ICRF 159 has an additive effect on interphase-lethal and a sub-additive effect on reproductive-lethal cell damage. Thus, favourable results may be expected for the electivity factor in fractionated irradiation and with regard to delayed damage in healthy tissue. (orig.) 891 MG/orig. 892 RDG [de

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.

In vitro and in vivo study of endothelial cells radio-induced death modulation by Sphingosine-1-Phosphate

International Nuclear Information System (INIS)

Bonnaud, St.

2007-01-01

Protecting the vasculature from radiation-induced death is a major concern in tissue radioprotection. Developing a model of endothelial cells radiosensitivity, we proved that HMEC-1 undergo 2 waves of death after exposure to 15 Gy: an early pre mitotic apoptosis dependent of ceramide generation and a delayed DNA damage-induced mitotic death. Sphingosine-1-Phosphate (S1P), a ceramide antagonist, protects HMEC-1 only from early apoptosis, but not from mitotic death. We confirmed in vivo the S1P radioprotection from ceramide-mediated radio-induced apoptosis, and that S1P radioprotection is partially mediated by S1Ps receptors. Segregation between these 2 types of death may give the opportunity to define a new class of radioprotectors for normal tissue where quiescent endothelium represent the most sensitive target, while excluding malignant tumor containing pro-proliferating angiogenic endothelial cells, sensitive to mitotic death. (author)

Ku70 inhibits gemcitabine-induced DNA damage and pancreatic cancer cell apoptosis

International Nuclear Information System (INIS)

Ma, Jiali; Hui, Pingping; Meng, Wenying; Wang, Na; Xiang, Shihao

2017-01-01

The current study focused on the role of Ku70, a DNA-dependent protein kinase (DNA-PK) complex protein, in pancreatic cancer cell resistance to gemcitabine. In both established cell lines (Mia-PaCa-2 and PANC-1) and primary human pancreatic cancer cells, shRNA/siRNA-mediated knockdown of Ku70 significantly sensitized gemcitabine-induced cell death and proliferation inhibition. Meanwhile, gemcitabine-induced DNA damage and subsequent pancreatic cancer cell apoptosis were also potentiated with Ku70 knockdown. On the other hand, exogenous overexpression of Ku70 in Mia-PaCa-2 cells suppressed gemcitabine-induced DNA damage and subsequent cell apoptosis. In a severe combined immune deficient (SCID) mice Mia-PaCa-2 xenograft model, gemcitabine-induced anti-tumor activity was remarkably pontificated when combined with Ku70 shRNA knockdown in the xenografts. The results of this preclinical study imply that Ku70 might be a primary resistance factor of gemcitabine, and Ku70 silence could significantly chemo-sensitize gemcitabine in pancreatic cancer cells. - Highlights: • Ku70 knockdown sensitizes gemcitabine-induced killing of pancreatic cancer cells. • Ku70 knockdown facilitates gemcitabine-induced DNA damage and cell apoptosis. • Ku70 overexpression deceases gemcitabine's sensitivity in pancreatic cancer cells. • Ku70 knockdown sensitizes gemcitabine-induced anti-tumor activity in vivo.

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.

Oxidative Stress Facilitates IFN-γ-Induced Mimic Extracellular Trap Cell Death in A549 Lung Epithelial Cancer Cells.

Science.gov (United States)

Lin, Chiou-Feng; Chen, Chia-Ling; Chien, Shun-Yi; Tseng, Po-Chun; Wang, Yu-Chih; Tsai, Tsung-Ting

2016-01-01

We previously demonstrated that IFN-γ induces an autophagy-regulated mimic extracellular trap cell death (ETosis) in A549 human lung cancer cells. Regarding reactive oxygen species (ROS) are involved in ETosis, this study investigated the role of oxidative stress. After IFN-γ stimulation, a necrosis-like cell death mimic ETosis occurred accompanied by the inhibition of cell growth, aberrant nuclear staining, and nucleosome release. ROS were generated in a time-dependent manner with an increase in NADPH oxidase component protein expression. STAT1-mediated IFN regulatory factor-1 activation was essential for upregulating ROS production. By genetically silencing p47phox, IFN-γ-induced ROS and mimic ETosis were significantly attenuated. This mechanistic study indicated that ROS may mediate DNA damage followed by histone H3 citrullination. Furthermore, ROS promoted IFN-γ-induced mimic ETosis in cooperation with autophagy. These findings further demonstrate that ROS regulates IFN-γ-induced mimic ETosis in lung epithelial malignancy.

Tauroursodeoxycholic acid attenuates gentamicin-induced cochlear hair cell death in vitro.

Science.gov (United States)

Jia, Zhanwei; He, Qiang; Shan, Chunguang; Li, Fengyi

2018-09-15

Gentamycin is one of the most clinically used aminoglycoside antibiotics which induce intrinsic apoptosis of hair cells. Tauroursodeoxycholic acid (TUDCA) is known as safe cell-protective agent in disorders associated with apoptosis. We aimed to investigate the protective effects of TUDCA against gentamicin-induced ototoxicity. House Ear Institute-Organ of Corti 1(HEI-OC1) cells and explanted cochlear tissue were treated with gentamicin and TUDCA, followed by serial analyses including cell viability assay, hair cell staining, qPCR, ELISA and western blotting to determine the cell damage by the parameters relevant to cell apoptosis and endoplasmic reticulum stress. TUDCA significantly attenuated gentamicin-induced cell damage in cultured HEI-OC1 cells and explanted cochlear hair cells. TUDCA alleviated gentamicin-induced cell apoptosis, supported by the decreased Bax/Bcl2 ratio compared with that of gentamicin treated alone. TUDCA decreased gentamicin-induced nitric oxide production and protein nitration in both models. In addition, TUDCA suppressed gentamicin-induced endoplasmic reticulum stress as reflected by inversing the expression levels of Binding immunoglobulin protein (Bip), CCAAT/-enhancer-binding protein homologous protein (CHOP) and Caspase 3. TUDCA attenuated gentamicin-induced hair cell death by inhibiting protein nitration activation and ER stress, providing new insights into the new potential therapies for sensorineural deafness. Copyright © 2018 Elsevier B.V. All rights reserved.

Synergistic antitumor cytotoxic actions of ascorbate and menadione on human prostate (DU145) cancer cells in vitro: nucleus and other injuries preceding cell death by autoschizis.

Science.gov (United States)

Gilloteaux, Jacques; Jamison, James M; Neal, Deborah; Summers, Jack L

2014-04-01

Scanning (SEM) and transmission electron microscopy (TEM) were used to characterize the cytotoxic effects of ascorbate (VC), menadione (VK3), or a VC:VK3 combination on a human prostate carcinoma cell line (DU145) following a 1-h vitamin treatment and a subsequent 24-h incubation in culture medium. Cell alterations examined by light and electron microscopy were treatment-dependent with VC + VK3 >VK3 > VC > Sham. Oxidative stress-induced damage was found in most organelles. This report describes injuries in the tumor cell nucleus (chromatin and nucleolus), mitochondria, endomembranes, lysosomal bodies (autophagocytoses) and inclusions. Morphologic alterations suggest that cytoskeleton damage is likely responsible for the superficial cytoplasmic changes, including major changes in cell shape and size and the self-excising phenomena. Unlike apoptotic bodies, the excised pieces contain ribonucleoproteins, but not organelles. These deleterious events cause a progressive, significant reduction in the tumor cell size. During nuclear alterations, the nuclei maintain their envelope during chromatolysis and karyolysis until cell death, while nucleoli undergo a characteristic segregation of their components. In addition, changes in fat and glycogen storage are consistent the cytotoxic and metabolic alterations caused by the respective treatments. All cellular ultrastructural changes are consistent with cell death by autoschizis and not apoptosis or other kinds of cell death.

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)

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.

ROS-mediated apoptotic cell death in prostate cancer LNCaP cells induced by biosurfactant stabilized CdS quantum dots.

Science.gov (United States)

Singh, Braj R; Singh, Brahma N; Khan, W; Singh, H B; Naqvi, A H

2012-08-01

Cadmium sulfide (CdS) quantum dots (QDs) have raised great attention because of their superior optical properties and wide utilization in biological and biomedical studies. However, little is known about the cell death mechanisms of CdS QDs in human cancer cells. This study was designed to investigate the possible mechanisms of apoptosis induced by biosurfactant stabilized CdS QDs (denoted as "bsCdS QDs") in human prostate cancer LNCaP cells. It was also noteworthy that apoptosis correlated with reactive oxygen species (ROS) production, mitochondrial damage, oxidative stress and chromatin condensation in a dose- and time-dependent manner. Results also showed involvement of caspases, Bcl-2 family proteins, heat shock protein 70, and a cell-cycle checkpoint protein p53 in apoptosis induction by bsCdS QDs in LNCaP cells. Moreover, pro-apoptotic protein Bax was upregulated and the anti-apoptotic proteins, survivin and NF-κB were downregulated in bsCdS QDs exposed cells. Protection of N-acetyl cysteine (NAC) against ROS clearly suggested the implication of ROS in hyper-activation of apoptosis and cell death. It is encouraging to conclude that biologically stabilized CdS QDs bear the potential of its applications in biomedicine, such as tumor therapy specifically by inducing caspase-dependent apoptotic cell death of human prostate cancer LNCaP cells. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

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...

DNA damage repair and radiosensitivity

International Nuclear Information System (INIS)

Suzuki, Norio

2003-01-01

Tailored treatment is not new in radiotherapy; it has been the major subject for the last 20-30 years. Radiation responses and RBE (relative biological effectiveness) depend on assay systems, endpoints, type of tissues and tumors, radiation quality, dose rate, dose fractionation, physiological and environmental factors etc, Latent times to develop damages also differ among tissues and endpoints depending on doses and radiation quality. Recent progress in clarification of radiation induced cell death, especially of apoptotic cell death, is quite important for understanding radiosensitivity of tumor cure process as well as of tumorigenesis. Apoptotic cell death as well as dormant cells had been unaccounted and missed into a part of reproductive cell death. Another area of major progress has been made in clarifying repair mechanisms of radiation damage, i.e., non-homologous end joining (NHEJ) and homologous recombinational repair (HRR). New approaches and developments such as cDNA or protein micro arrays and so called informatics in addition to basic molecular biological analysis are expected to aid identifying molecules and their roles in signal transduction pathways, which are multi-factorial and interactive each other being involved in radiation responses. (authors)

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.

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.

Caspase-3 activation as a bifurcation point between plasticity and cell death

Institute of Scientific and Technical Information of China (English)

Shikha Snigdha; Erica D Smith; G Aleph Prieto; Carl W Cotman

2012-01-01

Death-mediating proteases such as caspases and caspase-3 in particular,have been implicated in neurodegenerative processes,aging and Alzheimer's disease.However,emerging evidence suggests that in addition to their classical role in cell death,caspases play a key role in modulating synaptic function.It is remarkable that active caspases-3,which can trigger widespread damage and degeneration,aggregates in structures as delicate as synapses and persists in neurons without causing acute cell death.Here,we evaluate this dichotomy,and discuss the hypothesis that caspase-3 may be a bifurcation point in cellular signaling,able to orient the neuronal response to stress down either pathological/apoptotic pathways or towards physiological cellular remodeling.We propose that temporal,spatial and other regulators of caspase activity are key determinants of the ultimate effect of caspase-3 activation in neurons.This concept has implications for differential roles of caspase-3 activation across the lifespan.Specifically,we propose that limited caspase-3 activation is critical for synaptic function in the healthy adult brain while chronic activation is involved in degenerative processes in the aging brain.

Molecular mechanisms in radiation damage to DNA

International Nuclear Information System (INIS)

Osman, R.

1991-01-01

The objectives of this work are to elucidate the molecular mechanisms that are responsible for radiation-induced DNA damage. The overall goal is to understand the relationship between the chemical and structural changes produced by ionizing radiation in DNA and the resulting impairment of biological function expressed as carcinogenesis or cell death. The studies are based on theoretical explorations of possible mechanisms that link initial radiation damage in the form of base and sugar damage to conformational changes in DNA. These mechanistic explorations should lead to the formulation of testable hypothesis regarding the processes of impairment of regulation of gene expression, alternation in DNA repair, and damage to DNA structure involved in cell death or cancer

Mechanisms of cell death in canine parvovirus-infected cells provide intuitive insights to developing nanotools for medicine

Directory of Open Access Journals (Sweden)

Jonna Nykky

2010-06-01

Full Text Available Jonna Nykky, Jenni E Tuusa, Sanna Kirjavainen, Matti Vuento, Leona GilbertNanoscience Center and Department of Biological and Environmental Science, University of Jyväskylä, FinlandAbstract: Viruses have great potential as nanotools in medicine for gene transfer, targeted gene delivery, and oncolytic cancer virotherapy. Here we have studied cell death mechanisms of canine parvovirus (CPV to increase the knowledge on the CPV life cycle in order to facilitate the development of better parvovirus vectors. Morphological studies of CPV-infected Norden laboratory feline kidney (NLFK cells and canine fibroma cells (A72 displayed characteristic apoptotic events. Apoptosis was further confirmed by activation of caspases and cellular DNA damage. However, results from annexin V-propidium iodide (PI labeling and membrane polarization assays indicated disruption of the plasma membrane uncommon to apoptosis. These results provide evidence that secondary necrosis followed apoptosis. In addition, two human cancer cell lines were found to be infected by CPV. This necrotic event over apoptotic cell death and infection in human cells provide insightful information when developing CPV as a nanotool for cancer treatments.Keywords: canine parvovirus, apoptosis, necrosis, nanoparticle, virotherapy

The effectiveness of small doses of ionizing radiations for the induction of cell reproductive death, chromosomal changes and malignant transformation

International Nuclear Information System (INIS)

Barendsen, G.W.

1976-01-01

For reproductive death of mammalian cells, accumulation of damage induced by two or more particles is frequently predominant at doses of X-rays or γ-rays in excess of 500 rad. For doses of less than 100 rad of X-rays, damage due to single particles generally provides the largest contribution to cell lethality, but the relative effectiveness depends strongly on the type of cell investigated and on the conditions of exposure and environment. In addition, a marked dependence on LET is observed. For LET values at which the relative contribution of accumulation of damage has become negligible, a significant influence of dose-modifying factors such as the presence of oxygen may still be evident. This implies that 'single particle damage' is not necessarily independent of modifying factors. A similar conclusion can be derived from data on some types of micro-organisms. For the induction of chromosome aberrations, published data show that the relative contributions of the two types of mechanisms mentioned, may depend on the type of aberration studied. For tumor induction the relative contributions of the two mechanisms cannot in general be derived from incidence versus dose relations because of the influence of promoting, permitting and inhibiting conditions and the influence of cell reproductive death

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.

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.

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.

Alkylation induced cerebellar degeneration dependent on Aag and Parp1 does not occur via previously established cell death mechanisms.

Directory of Open Access Journals (Sweden)

Carrie M Margulies

Full Text Available Alkylating agents are ubiquitous in our internal and external environments, causing DNA damage that contributes to mutations and cell death that can result in aging, tissue degeneration and cancer. Repair of methylated DNA bases occurs primarily through the base excision repair (BER pathway, a multi-enzyme pathway initiated by the alkyladenine DNA glycosylase (Aag, also known as Mpg. Previous work demonstrated that mice treated with the alkylating agent methyl methanesulfonate (MMS undergo cerebellar degeneration in an Aag-dependent manner, whereby increased BER initiation by Aag causes increased tissue damage that is dependent on activation of poly (ADP-ribose polymerase 1 (Parp1. Here, we dissect the molecular mechanism of cerebellar granule neuron (CGN sensitivity to MMS using primary ex vivo neuronal cultures. We first established a high-throughput fluorescent imaging method to assess primary neuron sensitivity to treatment with DNA damaging agents. Next, we verified that the alkylation sensitivity of CGNs is an intrinsic phenotype that accurately recapitulates the in vivo dependency of alkylation-induced CGN cell death on Aag and Parp1 activity. Finally, we show that MMS-induced CGN toxicity is independent of all the cellular events that have previously been associated with Parp-mediated toxicity, including mitochondrial depolarization, AIF translocation, calcium fluxes, and NAD+ consumption. We therefore believe that further investigation is needed to adequately describe all varieties of Parp-mediated cell death.

Alkylation induced cerebellar degeneration dependent on Aag and Parp1 does not occur via previously established cell death mechanisms.

Science.gov (United States)

Margulies, Carrie M; Chaim, Isaac Alexander; Mazumder, Aprotim; Criscione, June; Samson, Leona D

2017-01-01

Alkylating agents are ubiquitous in our internal and external environments, causing DNA damage that contributes to mutations and cell death that can result in aging, tissue degeneration and cancer. Repair of methylated DNA bases occurs primarily through the base excision repair (BER) pathway, a multi-enzyme pathway initiated by the alkyladenine DNA glycosylase (Aag, also known as Mpg). Previous work demonstrated that mice treated with the alkylating agent methyl methanesulfonate (MMS) undergo cerebellar degeneration in an Aag-dependent manner, whereby increased BER initiation by Aag causes increased tissue damage that is dependent on activation of poly (ADP-ribose) polymerase 1 (Parp1). Here, we dissect the molecular mechanism of cerebellar granule neuron (CGN) sensitivity to MMS using primary ex vivo neuronal cultures. We first established a high-throughput fluorescent imaging method to assess primary neuron sensitivity to treatment with DNA damaging agents. Next, we verified that the alkylation sensitivity of CGNs is an intrinsic phenotype that accurately recapitulates the in vivo dependency of alkylation-induced CGN cell death on Aag and Parp1 activity. Finally, we show that MMS-induced CGN toxicity is independent of all the cellular events that have previously been associated with Parp-mediated toxicity, including mitochondrial depolarization, AIF translocation, calcium fluxes, and NAD+ consumption. We therefore believe that further investigation is needed to adequately describe all varieties of Parp-mediated cell death.

Umbelliferone arrest cell cycle at G0/G1 phase and induces apoptosis in human oral carcinoma (KB) cells possibly via oxidative DNA damage.

Science.gov (United States)

Vijayalakshmi, Annamalai; Sindhu, Ganapathy

2017-08-01

Umbelliferone (UMB) has widespread pharmacological activity, comprising anti-inflammatory, anti-oxidant, anti-genotoxic and anti-immunomodulatory but the anticancer activity remains unknown in human oral carcinoma (HOC) KB cells. MTT assay determinations was revealed that treatment of KB cells with UMB, prevent and reduce the cell proliferation with the IC 50 - 200μM as well as induces loss of cell viability, morphology change and internucleosomal DNA fragmentation in a concentration dependent manner. Acridine orange and ethidium bromide dual staining assay established that UMB induced apoptosis in KB cells in a dose dependent manner. Alkaline comet assay determination revealed UMB has the potential to increase oxidative DNA damage in KB cells through DNA tail formation significantly (pKB cells. Similarly, we observed increased DNA damage stimulated apoptotic morphological changes in UMB treated cells. Taken together, the present study suggests that UMB exhibits anticancer effect on KB cell line with the increased generation of intracellular ROS, triggered oxidative stress mediated depolarization of mitochondria, which contributes cell death via DNA damage as well as cell cycle arrest at G0/G1 phase. The results have also provided us insight in the pharmacological backgrounds for the potential use of UMB, to target divergent pathways of cell survival and cell death. To conclude UMB could develop as a novel candidate for cancer chemoprevention and therapy, which is our future focus and to develop a connectivity map between in vivo and in vitro activity. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

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.

Minocycline attenuates both OGD-induced HMGB1 release and HMGB1-induced cell death in ischemic neuronal injury in PC12 cells

Energy Technology Data Exchange (ETDEWEB)

Kikuchi, Kiyoshi [Division of Laboratory and Vascular Medicine, Field of Cardiovascular and Respiratory Disorders, Department of Advanced Therapeutics, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8520 (Japan); Department of Neurosurgery, Omuta City General Hospital, 2-19-1 Takarazaka, Omuta-City, Fukuoka 836-8567 (Japan); Kawahara, Ko-ichi; Biswas, Kamal Krishna; Ito, Takashi [Division of Laboratory and Vascular Medicine, Field of Cardiovascular and Respiratory Disorders, Department of Advanced Therapeutics, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8520 (Japan); Tancharoen, Salunya [Department of Pharmacology, Faculty of Dentistry, Mahidol University, 6 Yothe Rd., Rajthevee Bangkok 10400 (Thailand); Morimoto, Yoko [Department of Periodontology, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8544 (Japan); Matsuda, Fumiyo [Division of Physical Therapy, School of Health Sciences, Faculty of Medicine, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima 890-8560 (Japan); Oyama, Yoko; Takenouchi, Kazunori [Division of Laboratory and Vascular Medicine, Field of Cardiovascular and Respiratory Disorders, Department of Advanced Therapeutics, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8520 (Japan); Miura, Naoki [Laboratory of Veterinary Diagnostic Imaging, Department of Veterinary Medicine, Faculty of Agriculture, Kagoshima University, 1-21-24 Korimoto, Kagoshima 890-0065 (Japan); Arimura, Noboru; Nawa, Yuko; Meng, Xiaojie; Shrestha, Binita; Arimura, Shinichiro [Division of Laboratory and Vascular Medicine, Field of Cardiovascular and Respiratory Disorders, Department of Advanced Therapeutics, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8520 (Japan); and others

2009-07-24

High mobility group box-1 (HMGB1), a non-histone DNA-binding protein, is massively released into the extracellular space from neuronal cells after ischemic insult and exacerbates brain tissue damage in rats. Minocycline is a semisynthetic second-generation tetracycline antibiotic which has recently been shown to be a promising neuroprotective agent. In this study, we found that minocycline inhibited HMGB1 release in oxygen-glucose deprivation (OGD)-treated PC12 cells and triggered the activation of p38mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinases (ERK1/2). The ERK kinase (MEK)1/2 inhibitor U-0126 and p38MAPK inhibitor SB203580 blocked HMGB1 release in response to OGD. Furthermore, HMGB1 triggered cell death in a dose-dependent fashion. Minocycline significantly rescued HMGB1-induced cell death in a dose-dependent manner. In light of recent observations as well as the good safety profile of minocycline in humans, we propose that minocycline might play a potent neuroprotective role through the inhibition of HMGB1-induced neuronal cell death in cerebral infarction.

Minocycline attenuates both OGD-induced HMGB1 release and HMGB1-induced cell death in ischemic neuronal injury in PC12 cells

International Nuclear Information System (INIS)

Kikuchi, Kiyoshi; Kawahara, Ko-ichi; Biswas, Kamal Krishna; Ito, Takashi; Tancharoen, Salunya; Morimoto, Yoko; Matsuda, Fumiyo; Oyama, Yoko; Takenouchi, Kazunori; Miura, Naoki; Arimura, Noboru; Nawa, Yuko; Meng, Xiaojie; Shrestha, Binita; Arimura, Shinichiro

2009-01-01

High mobility group box-1 (HMGB1), a non-histone DNA-binding protein, is massively released into the extracellular space from neuronal cells after ischemic insult and exacerbates brain tissue damage in rats. Minocycline is a semisynthetic second-generation tetracycline antibiotic which has recently been shown to be a promising neuroprotective agent. In this study, we found that minocycline inhibited HMGB1 release in oxygen-glucose deprivation (OGD)-treated PC12 cells and triggered the activation of p38mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinases (ERK1/2). The ERK kinase (MEK)1/2 inhibitor U-0126 and p38MAPK inhibitor SB203580 blocked HMGB1 release in response to OGD. Furthermore, HMGB1 triggered cell death in a dose-dependent fashion. Minocycline significantly rescued HMGB1-induced cell death in a dose-dependent manner. In light of recent observations as well as the good safety profile of minocycline in humans, we propose that minocycline might play a potent neuroprotective role through the inhibition of HMGB1-induced neuronal cell death in cerebral infarction.

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....

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.

Ongoing cell death and immune influences on regeneration in the vestibular sensory organs

Science.gov (United States)

Warchol, M. E.; Matsui, J. I.; Simkus, E. L.; Ogilive, J. M.

2001-01-01

Hair cells in the vestibular organs of birds have a relatively short life span. Mature hair cells appear to die spontaneously and are then quickly replaced by new hair cells that arise from the division of epithelial supporting cells. A similar regenerative mechanism also results in hair cell replacement after ototoxic damage. The cellular basis of hair cell turnover in the avian ear is not understood. We are investigating the signaling pathways that lead to hair cell death and the relationship between ongoing cell death and cell production. In addition, work from our lab and others has demonstrated that the avian inner ear contains a resident population of macrophages and that enhanced numbers of macrophages are recruited to sites of hair cells lesions. Those observations suggest that macrophages and their secretory products (cytokines) may be involved in hair cell regeneration. Consistent with that suggestion, we have found that treatment with the anti-inflammatory drug dexamethasone reduces regenerative cell proliferation in the avian ear, and that certain macrophage-secreted cytokines can influence the proliferation of vestibular supporting cells and the survival of statoacoustic neurons. Those results suggest a role for the immune system in the process of sensory regeneration in the inner ear.

Radioprotection against DNA damage by an extract of Indian green mussel, Perna viridis (L.)

Digital Repository Service at National Institute of Oceanography (India)

Kumaran, S.P.; Kutty, B.C.; Chatterji, A.; Parameswaran, P.S.; Mishra, K.P.

-irradiation Prevention of DNA damage both in plasmid and lymphocytes and cell death in lymphocytes appears correlated with reduction of oxidatively generated free radicals It is concluded that protection against radiation-induced cell death and DNA damage by MH...

Choline and/or folic acid deficiency is associated with genomic damage and cell death in human lymphocytes in vitro.

Science.gov (United States)

Lu, Lin; Ni, Juan; Zhou, Tao; Xu, Weijiang; Fenech, Michael; Wang, Xu

2012-04-01

Choline and folate are interrelated methyl donors. Previous studies showed that folate prevents genomic damage in human lymphocytes in vitro; however, the association between choline and human genomic stability is uncertain. To explore the genotoxicity, cytotoxicity, and cytostatic effects and possible interactions of choline and/or folate deficiency on the human genome, lymphocytes from 6 volunteers were cultured in 18 combinations of choline (CC) and folic acid (FA) media for 9 days. The genotoxicity was evaluated by micronuclei, nucleoplasmic bridges, and nuclear buds in the binucleated cell; the cytotoxicity indices included apoptosis and necrosis, and the cytostatic effects were indicated by nuclear division index (NDI). Across all choline concentrations, the frequencies of all biomarkers except NDI were diminished when FA concentration was more than or equal to 120 nmol/L. The frequencies of micronuclei, buds, and necrosis were significantly higher at lower levels of CC (0-6 μmol/L) compared with higher concentrations of CC (12-21.5 μmol/L) while maintaining the same FA concentration. We concluded that both choline and folate significantly impact genomic stability and cell death, although effects of folate were 2.5- to 6.2-fold greater, depending on the biomarker and dose. A combination of 12 μmol/L CC and 120 nmol/L FA appears to be optimal for genomic integrity in vitro.

Effect of cell cycle stage, dose rate and repair of sublethal damage of radiation-induced apoptosis in F9 teratocarcinoma cells

International Nuclear Information System (INIS)

Langley, R.E.; Quartuccio, S.G.; Kennealey, P.T.

1995-01-01

There are at least two different models of cell death after treatment with ionizing radiation. The first is a failure to undergo sustained cell division despite metabolic survival, and we refer to this end point as open-quotes classical reproductive cell death.close quotes The second is a process that results in loss of cell integrity. This second category includes cellular necrosis as well as apoptosis. Earlier studies in our laboratory showed that the predominant mechanism of cell death for irradiated F9 cell is apoptosis, and there is no indication that these cells die by necrosis. We have therefore used cells of this cell line to reassess basic radiobiological principles with respect to apoptosis. Classical reproductive cell death was determined by staining colonies derived from irradiated cells and scoring colonies of less than 50 cells as reproductively dead and colonies of more than 50 cells as survivors. Cells that failed to produce either type of colony (detached from the plate or disintegrated) were scored as having undergone apoptosis. Using these criteria we found that the fraction of the radiation-killed F9 cells that died by apoptosis did not vary when cells were irradiated at different stages of the cell cycle despite large variations in overall survival. This suggests that the factors that influence radiation sensitivity throughout the cell cycle have an equal impact on apoptosis and classical reproductive cell death. There was no difference in cell survival between split doses and single doses of X rays, suggesting that sublethal damage repair is not a factor in radiation-induced apoptosis of F9 cells. Apoptosis was not affected by changes in dose rate in the range of 0.038-4.96 Gy/min. 48 refs., 6 figs., 1 tab

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...

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.

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.

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

The sirtuin 1/2 inhibitor tenovin-1 induces a nonlinear apoptosis-inducing factor-dependent cell death in a p53 null Ewing's sarcoma cell line.

Science.gov (United States)

Marx, Christian; Marx-Blümel, Lisa; Lindig, Nora; Thierbach, René; Hoelzer, Doerte; Becker, Sabine; Wittig, Susan; Lehmann, Roland; Slevogt, Hortense; Heinzel, Thorsten; Wang, Zhao-Qi; Beck, James F; Sonnemann, Jürgen

2018-06-01

The sirtuin 1/2 inhibitor tenovin-1 activates p53 and may have potential in the management of cancer. Here, we investigated the responsiveness of Ewing's sarcoma cells to tenovin-1. We examined its effects in two Ewing's sarcoma cell lines with different p53 status, i.e. in p53 wild-type and p53 null cells. Effects were assessed by flow cytometric analyses of cell death, mitochondrial membrane depolarization and reactive oxygen species (ROS) generation, by caspase 3/7 activity measurement, by mRNA expression profiling and by immunoblotting. Tenovin-1 elicited caspase-mediated cell death in p53 wild-type cells, but caspase-independent cell death in p53 null cells. Remarkably, it induced a nonlinear concentration response in the latter: low concentrations of tenovin-1 were much more effective than were higher concentrations. Tenovin-1's effects in p53 null cells involved gene expression changes of Bcl-2 family members, mitochondrial membrane depolarization, nuclear translocation of apoptosis-inducing factor, ROS formation and DNA damage; all these effects followed a bell-shaped pattern. In conclusion, our results provide new insights into tenovin-1's mode of action by demonstrating that it can induce different pathways of cell death.

Lovastatin prevents cisplatin-induced activation of pro-apoptotic DNA damage response (DDR) of renal tubular epithelial cells

Energy Technology Data Exchange (ETDEWEB)

Krüger, Katharina; Ziegler, Verena; Hartmann, Christina; Henninger, Christian [Institute of Toxicology, Medical Faculty, Heinrich Heine University Düsseldorf, 40225 Düsseldorf (Germany); Thomale, Jürgen [Institute of Cell Biology, University Duisburg-Essen, 45122 Essen (Germany); Schupp, Nicole [Institute of Toxicology, Medical Faculty, Heinrich Heine University Düsseldorf, 40225 Düsseldorf (Germany); Fritz, Gerhard, E-mail: fritz@uni-duesseldorf.de [Institute of Toxicology, Medical Faculty, Heinrich Heine University Düsseldorf, 40225 Düsseldorf (Germany)

2016-02-01

The platinating agent cisplatin (CisPt) is commonly used in the therapy of various types of solid tumors. The anticancer efficacy of CisPt largely depends on the formation of bivalent DNA intrastrand crosslinks, which stimulate mechanisms of the DNA damage response (DDR), thereby triggering checkpoint activation, gene expression and cell death. The clinically most relevant adverse effect associated with CisPt treatment is nephrotoxicity that results from damage to renal tubular epithelial cells. Here, we addressed the question whether the HMG-CoA-reductase inhibitor lovastatin affects the DDR of renal cells by employing rat renal proximal tubular epithelial (NRK-52E) cells as in vitro model. The data show that lovastatin has extensive inhibitory effects on CisPt-stimulated DDR of NRK-52E cells as reflected on the levels of phosphorylated ATM, Chk1, Chk2, p53 and Kap1. Mitigation of CisPt-induced DDR by lovastatin was independent of the formation of DNA damage as demonstrated by (i) the analysis of Pt-(GpG) intrastrand crosslink formation by Southwestern blot analyses and (ii) the generation of DNA strand breaks as analyzed on the level of nuclear γH2AX foci and employing the alkaline comet assay. Lovastatin protected NRK-52E cells from the cytotoxicity of high CisPt doses as shown by measuring cell viability, cellular impedance and flow cytometry-based analyses of cell death. Importantly, the statin also reduced the level of kidney DNA damage and apoptosis triggered by CisPt treatment of mice. The data show that the lipid-lowering drug lovastatin extensively counteracts pro-apoptotic signal mechanisms of the DDR of tubular epithelial cells following CisPt injury. - Highlights: • Lovastatin blocks ATM/ATR-regulated DDR of tubular cells following CisPt treatment. • Lovastatin attenuates CisPt-induced activation of protein kinase ATM in vitro. • Statin-mediated DDR inhibition is independent of initial DNA damage formation. • Statin-mediated blockage of Cis

Lovastatin prevents cisplatin-induced activation of pro-apoptotic DNA damage response (DDR) of renal tubular epithelial cells

International Nuclear Information System (INIS)

Krüger, Katharina; Ziegler, Verena; Hartmann, Christina; Henninger, Christian; Thomale, Jürgen; Schupp, Nicole; Fritz, Gerhard

2016-01-01

The platinating agent cisplatin (CisPt) is commonly used in the therapy of various types of solid tumors. The anticancer efficacy of CisPt largely depends on the formation of bivalent DNA intrastrand crosslinks, which stimulate mechanisms of the DNA damage response (DDR), thereby triggering checkpoint activation, gene expression and cell death. The clinically most relevant adverse effect associated with CisPt treatment is nephrotoxicity that results from damage to renal tubular epithelial cells. Here, we addressed the question whether the HMG-CoA-reductase inhibitor lovastatin affects the DDR of renal cells by employing rat renal proximal tubular epithelial (NRK-52E) cells as in vitro model. The data show that lovastatin has extensive inhibitory effects on CisPt-stimulated DDR of NRK-52E cells as reflected on the levels of phosphorylated ATM, Chk1, Chk2, p53 and Kap1. Mitigation of CisPt-induced DDR by lovastatin was independent of the formation of DNA damage as demonstrated by (i) the analysis of Pt-(GpG) intrastrand crosslink formation by Southwestern blot analyses and (ii) the generation of DNA strand breaks as analyzed on the level of nuclear γH2AX foci and employing the alkaline comet assay. Lovastatin protected NRK-52E cells from the cytotoxicity of high CisPt doses as shown by measuring cell viability, cellular impedance and flow cytometry-based analyses of cell death. Importantly, the statin also reduced the level of kidney DNA damage and apoptosis triggered by CisPt treatment of mice. The data show that the lipid-lowering drug lovastatin extensively counteracts pro-apoptotic signal mechanisms of the DDR of tubular epithelial cells following CisPt injury. - Highlights: • Lovastatin blocks ATM/ATR-regulated DDR of tubular cells following CisPt treatment. • Lovastatin attenuates CisPt-induced activation of protein kinase ATM in vitro. • Statin-mediated DDR inhibition is independent of initial DNA damage formation. • Statin-mediated blockage of Cis

Glutamine deficiency induces DNA alkylation damage and sensitizes cancer cells to alkylating agents through inhibition of ALKBH enzymes.

Directory of Open Access Journals (Sweden)

Thai Q Tran

2017-11-01

Full Text Available Driven by oncogenic signaling, glutamine addiction exhibited by cancer cells often leads to severe glutamine depletion in solid tumors. Despite this nutritional environment that tumor cells often experience, the effect of glutamine deficiency on cellular responses to DNA damage and chemotherapeutic treatment remains unclear. Here, we show that glutamine deficiency, through the reduction of alpha-ketoglutarate, inhibits the AlkB homolog (ALKBH enzymes activity and induces DNA alkylation damage. As a result, glutamine deprivation or glutaminase inhibitor treatment triggers DNA damage accumulation independent of cell death. In addition, low glutamine-induced DNA damage is abolished in ALKBH deficient cells. Importantly, we show that glutaminase inhibitors, 6-Diazo-5-oxo-L-norleucine (DON or CB-839, hypersensitize cancer cells to alkylating agents both in vitro and in vivo. Together, the crosstalk between glutamine metabolism and the DNA repair pathway identified in this study highlights a potential role of metabolic stress in genomic instability and therapeutic response in cancer.

Glutamine deficiency induces DNA alkylation damage and sensitizes cancer cells to alkylating agents through inhibition of ALKBH enzymes.

Science.gov (United States)

Tran, Thai Q; Ishak Gabra, Mari B; Lowman, Xazmin H; Yang, Ying; Reid, Michael A; Pan, Min; O'Connor, Timothy R; Kong, Mei

2017-11-01

Driven by oncogenic signaling, glutamine addiction exhibited by cancer cells often leads to severe glutamine depletion in solid tumors. Despite this nutritional environment that tumor cells often experience, the effect of glutamine deficiency on cellular responses to DNA damage and chemotherapeutic treatment remains unclear. Here, we show that glutamine deficiency, through the reduction of alpha-ketoglutarate, inhibits the AlkB homolog (ALKBH) enzymes activity and induces DNA alkylation damage. As a result, glutamine deprivation or glutaminase inhibitor treatment triggers DNA damage accumulation independent of cell death. In addition, low glutamine-induced DNA damage is abolished in ALKBH deficient cells. Importantly, we show that glutaminase inhibitors, 6-Diazo-5-oxo-L-norleucine (DON) or CB-839, hypersensitize cancer cells to alkylating agents both in vitro and in vivo. Together, the crosstalk between glutamine metabolism and the DNA repair pathway identified in this study highlights a potential role of metabolic stress in genomic instability and therapeutic response in cancer.

Patterns of DNA damage response in intracranial germ cell tumors versus glioblastomas reflect cell of origin rather than brain environment

DEFF Research Database (Denmark)

Bartkova, Jirina; Hoei-Hansen, Christina E; Krizova, Katerina

2014-01-01

The DNA damage response (DDR) machinery becomes commonly activated in response to oncogenes and during early stages of development of solid malignancies, with an exception of testicular germ cell tumors (TGCTs). The active DDR signaling evokes cell death or senescence but this anti-tumor barrier ...... checkpoints in intracranial tumorigenesis, with implications for the differential biological responses of diverse tumor types to endogenous stress as well as to genotoxic treatments such as ionizing radiation or chemotherapy....

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.

Effects of γ (60Co) and β (90Sr) radiations in Chinese hamster ovarian cells (CHO-K1): induction of micronuclei and cell death

International Nuclear Information System (INIS)

Murakami, Daniella

2003-01-01

Among various types of ionising radiation, the beta emitter radionuclides are involved in many sectors of human activity, such as nuclear medicine, nuclear industries and biomedicine, with a consequent increased risk of accidental, occupational or therapeutic exposure. Despite their recognized importance, there is little information about the effect of beta particles at the cellular level when compared to other types of ionizing radiation. Thus, the objective of the present study was to evaluate the genotoxic and cytotoxic effects of 90 Sr, a pure, highly energetic beta source, on CHO-K1 cells and to compare them with data obtained with 60 Co. CHO-K1 cells irradiated with different doses (1.0, 2.5, 5.0, 7.5 Gy) of 60 Co (0.34 Gy.min -1 ) and 90 Sr (0.23 Gy.min -1 ) were processed for analysis of clonogenic death, induction of micronuclei (MN) and necrotic and apoptotic death. The survival curves obtained for both types of radiation were better fitted by the linear-quadratic model and were similar. However, the cytogenetic results showed that both the proportion of micronucleated cells and the magnitude of radioinduced lesions demonstrated by the analysis of MN distribution were significantly higher in cells irradiated with 60 Co than in cells irradiated with 90 Sr, whereas 90 Sr was more damaging than 60 Co in terms of cell death induction. Necrosis was the major type of death observed in CHO-K1 cells. The data obtained suggest that the low incidence of micronucleated cells after exposure to 90 Sr may be a consequence of selective elimination of severely damaged cells from the population by the necrotic process at a higher rate than observed with 60 Co exposure. The data obtained also demonstrated the need to use several parameters for a better estimate of cellular sensitivity to the action of genotoxic agents, which would be important in terms of radiobiology, oncology and therapeutics. (author)

A chalcone-related small molecule that induces methuosis, a novel form of non-apoptotic cell death, in glioblastoma cells.

Science.gov (United States)

Overmeyer, Jean H; Young, Ashley M; Bhanot, Haymanti; Maltese, William A

2011-06-06

Methuosis is a unique form of non-apoptotic cell death triggered by alterations in the trafficking of clathrin-independent endosomes, ultimately leading to extreme vacuolization and rupture of the cell. Here we describe a novel chalcone-like molecule, 3-(2-methyl-1H- indol-3-yl)-1-(4-pyridinyl)-2-propen-1-one (MIPP) that induces cell death with the hallmarks of methuosis. MIPP causes rapid accumulation of vacuoles derived from macropinosomes, based on time-lapse microscopy and labeling with extracellular fluid phase tracers. Vacuolization can be blocked by the cholesterol-interacting compound, filipin, consistent with the origin of the vacuoles from non-clathrin endocytic compartments. Although the vacuoles rapidly acquire some characteristics of late endosomes (Rab7, LAMP1), they remain distinct from lysosomal and autophagosomal compartments, suggestive of a block at the late endosome/lysosome boundary. MIPP appears to target steps in the endosomal trafficking pathway involving Rab5 and Rab7, as evidenced by changes in the activation states of these GTPases. These effects are specific, as other GTPases (Rac1, Arf6) are unaffected by the compound. Cells treated with MIPP lose viability within 2-3 days, but their nuclei show no evidence of apoptotic changes. Inhibition of caspase activity does not protect the cells, consistent with a non-apoptotic death mechanism. U251 glioblastoma cells selected for temozolomide resistance showed sensitivity to MIPP-induced methuosis that was comparable to the parental cell line. MIPP might serve as a prototype for new drugs that could be used to induce non-apoptotic death in cancers that have become refractory to agents that work through DNA damage and apoptotic mechanisms.

A chalcone-related small molecule that induces methuosis, a novel form of non-apoptotic cell death, in glioblastoma cells

Directory of Open Access Journals (Sweden)

Bhanot Haymanti

2011-06-01

Full Text Available Abstract Background Methuosis is a unique form of non-apoptotic cell death triggered by alterations in the trafficking of clathrin-independent endosomes, ultimately leading to extreme vacuolization and rupture of the cell. Results Here we describe a novel chalcone-like molecule, 3-(2-methyl-1H- indol-3-yl-1-(4-pyridinyl-2-propen-1-one (MIPP that induces cell death with the hallmarks of methuosis. MIPP causes rapid accumulation of vacuoles derived from macropinosomes, based on time-lapse microscopy and labeling with extracellular fluid phase tracers. Vacuolization can be blocked by the cholesterol-interacting compound, filipin, consistent with the origin of the vacuoles from non-clathrin endocytic compartments. Although the vacuoles rapidly acquire some characteristics of late endosomes (Rab7, LAMP1, they remain distinct from lysosomal and autophagosomal compartments, suggestive of a block at the late endosome/lysosome boundary. MIPP appears to target steps in the endosomal trafficking pathway involving Rab5 and Rab7, as evidenced by changes in the activation states of these GTPases. These effects are specific, as other GTPases (Rac1, Arf6 are unaffected by the compound. Cells treated with MIPP lose viability within 2-3 days, but their nuclei show no evidence of apoptotic changes. Inhibition of caspase activity does not protect the cells, consistent with a non-apoptotic death mechanism. U251 glioblastoma cells selected for temozolomide resistance showed sensitivity to MIPP-induced methuosis that was comparable to the parental cell line. Conclusions MIPP might serve as a prototype for new drugs that could be used to induce non-apoptotic death in cancers that have become refractory to agents that work through DNA damage and apoptotic mechanisms.

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...

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

there are a number of pathways that are affected with genistein and vorinostat treatment such as Wnt, TNF, G2/M DNA damage checkpoint, and androgen signaling pathways. In addition, genistein cooperates with vorinostat to induce cell death in prostate cancer cell lines with a greater effect on early stage prostate cancer.

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.

Radiation and thermal characteristics of L5178Y-sensitive cells and usefulness of eosin staining method to detect heat-induced cell death

Energy Technology Data Exchange (ETDEWEB)

Nishioka, Yasuji (Hiroshima Univ. (Japan). School of Medicine)

1990-08-01

Radiosensitivity, thermosensitivity, drug sensitivity and their combined effects were investigated in mouse L5178Y-wild cells (LY-W) and L5178Y-sensitive cells (LY-S). The following results were obtained: LY-S were more radiosensitive than LY-W but were similar in their thermosensitivity. Thermotolerance induction was similar but the decay was faster in LY-W which had a shorter doubling time. The radiosensitizing effect of heating was similar in both cell lines. The thermal enhancement ratio was higher for a longer duration of heating at 42degC than for a shorter duration at 44degC, both of which exhibited a similar level of survival when applied alone. The eosin staining method was useful to detect heat-induced interphase death and thermal sensitizing effects of drugs. In LY-W, interphase death was the main mode of hyperthermic cell killing and was independent of the hyperthermic temperature, whereas in LY-S, the percentage of interphase death increased with the hyperthermic temperature. Procaine and bleomycin sensitized both cells to heat. Survival estimated by the eosin staining method shifted towards that obtained by colony forming method in heated LY-S after procaine. Sensitization to heat by procaine suggests that interphase death after hyperthermia is probably due to membrane damage. Comparison of the present work with previous ones, further suggests that with an increase in thermosensitivity, there is an increase in heat-induced interphase death. (author) 67 refs.

Radiation and thermal characteristics of L5178Y-sensitive cells and usefulness of eosin staining method to detect heat-induced cell death

International Nuclear Information System (INIS)

Nishioka, Yasuji

1990-01-01

Radiosensitivity, thermosensitivity, drug sensitivity and their combined effects were investigated in mouse L5178Y-wild cells (LY-W) and L5178Y-sensitive cells (LY-S). The following results were obtained: LY-S were more radiosensitive than LY-W but were similar in their thermosensitivity. Thermotolerance induction was similar but the decay was faster in LY-W which had a shorter doubling time. The radiosensitizing effect of heating was similar in both cell lines. The thermal enhancement ratio was higher for a longer duration of heating at 42degC than for a shorter duration at 44degC, both of which exhibited a similar level of survival when applied alone. The eosin staining method was useful to detect heat-induced interphase death and thermal sensitizing effects of drugs. In LY-W, interphase death was the main mode of hyperthermic cell killing and was independent of the hyperthermic temperature, whereas in LY-S, the percentage of interphase death increased with the hyperthermic temperature. Procaine and bleomycin sensitized both cells to heat. Survival estimated by the eosin staining method shifted towards that obtained by colony forming method in heated LY-S after procaine. Sensitization to heat by procaine suggests that interphase death after hyperthermia is probably due to membrane damage. Comparison of the present work with previous ones, further suggests that with an increase in thermosensitivity, there is an increase in heat-induced interphase death. (author) 67 refs

Acrolein preferentially damages nucleolus eliciting ribosomal stress and apoptosis in human cancer cells.

Science.gov (United States)

Wang, Hsiang-Tsui; Chen, Tzu-Ying; Weng, Ching-Wen; Yang, Chun-Hsiang; Tang, Moon-Shong

2016-12-06

Acrolein (Acr) is a potent cytotoxic and DNA damaging agent which is ubiquitous in the environment and abundant in tobacco smoke. Acr is also an active cytotoxic metabolite of the anti-cancer drugs cyclophosphamide and ifosfamide. The mechanisms via which Acr exerts its anti-cancer activity and cytotoxicity are not clear. In this study, we found that Acr induces cytotoxicity and cell death in human cancer cells with different activities of p53. Acr preferentially binds nucleolar ribosomal DNA (rDNA) to form Acr-deoxyguanosine adducts, and induces oxidative damage to both rDNA and ribosomal RNA (rRNA). Acr triggers ribosomal stress responses, inhibits rRNA synthesis, reduces RNA polymerase I binding to the promoter of rRNA gene, disrupts nucleolar integrity, and impairs ribosome biogenesis and polysome formation. Acr causes an increase in MDM2 levels and phosphorylation of MDM2 in A549 and HeLa cells which are p53 active and p53 inactive, respectively. It enhances the binding of ribosomal protein RPL11 to MDM2 and reduces the binding of p53 and E2F-1 to MDM2 resulting in stabilization/activation of p53 in A549 cells and degradation of E2F-1 in A549 and HeLa cells. We propose that Acr induces ribosomal stress which leads to activation of MDM2 and RPL11-MDM2 binding, consequently, activates p53 and enhances E2F-1 degradation, and that taken together these two processes induce apoptosis and cell death.

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

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.

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.

Homeostatic Mass Control in Gastric Non-Neoplastic Epithelia under Infection of Helicobacter pylori: An Immunohistochemical Analysis of Cell Growth, Stem Cells and Programmed Cell Death

International Nuclear Information System (INIS)

Kato, Kenji; Hasui, Kazuhisa; Wang, Jia; Kawano, Yoshifumi; Aikou, Takashi; Murata, Fusayoshi

2008-01-01

We evaluated homeostatic mass control in non-neoplastic gastric epithelia under Helicobacter pylori (HP) infection in the macroscopically normal-appearing mucosa resected from the stomach with gastric cancer, immunohistochemically analyzing the proliferation, kinetics of stem cells and programmed cell death occurring in them. Ki67 antigen-positive proliferating cells were found dominantly in the elongated neck portion, sparsely in the fundic areas and sporadically in the stroma with chronic infiltrates. CD117 could monitor the kinetics of gastric stem cells and showed its expression in two stages of gastric epithelial differentiation, namely, in transient cells from the gastric epithelial stem cells to the foveolar and glandular cells in the neck portion and in what are apparently progenitor cells from the gastric stem cells in the stroma among the infiltrates. Most of the nuclei were positive for ssDNA in the almost normal mucosa, suggesting DNA damage. Cleaved caspase-3-positive foveolar cells were noted under the surface, suggesting the suppression of apoptosis in the surface foveolar cells. Besides such apoptosis of the foveolar cells, in the severely inflamed mucosa apoptotic cells were found in the neck portion where most of the cells were Ki67 antigen-positive proliferating cells. Beclin-1 was recognized in the cytoplasm and in a few nuclei of the fundic glandular cells, suggesting their autophagic cell death and mutated beclin-1 in the nuclei. Taken together, the direct and indirect effects of HP infection on the gastric epithelial proliferation, differentiation and programmed cell death suggested the in-situ occurrence of gastric cancer under HP infection

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.

Diphtheria Toxin-Induced Cell Death Triggers Wnt-Dependent Hair Cell Regeneration in Neonatal Mice.

Science.gov (United States)

Hu, Lingxiang; Lu, Jingrong; Chiang, Hao; Wu, Hao; Edge, Albert S B; Shi, Fuxin

2016-09-07

Cochlear hair cells (HCs), the sensory cells that respond to sound, do not regenerate after damage in adult mammals, and their loss is a major cause of deafness. Here we show that HC regeneration in newborn mouse ears occurred spontaneously when the original cells were ablated by treatment with diphtheria toxin (DT) in ears that had been engineered to overexpress the DT receptor, but was not detectable when HCs were ablated in vivo by the aminoglycoside antibiotic neomycin. A variety of Wnts (Wnt1, Wnt2, Wnt2b, Wnt4, Wnt5a, Wnt7b, Wnt9a, Wnt9b, and Wnt11) and Wnt pathway component Krm2 were upregulated after DT damage. Nuclear β-catenin was upregulated in HCs and supporting cells of the DT-damaged cochlea. Pharmacological inhibition of Wnt decreased spontaneous regeneration, confirming a role of Wnt signaling in HC regeneration. Inhibition of Notch signaling further potentiated supporting cell proliferation and HC differentiation that occurred spontaneously. The absence of new HCs in the neomycin ears was correlated to less robust Wnt pathway activation, but the ears subjected to neomycin treatment nonetheless showed increased cell division and HC differentiation after subsequent forced upregulation of β-catenin. These studies suggest, first, that Wnt signaling plays a key role in regeneration, and, second, that the outcome of a regenerative response to damage in the newborn cochlea is determined by reaching a threshold level of Wnt signaling rather than its complete absence or presence. Sensory HCs of the inner ear do not regenerate in the adult, and their loss is a major cause of deafness. We found that HCs regenerated spontaneously in the newborn mouse after diphtheria toxin (DT)-induced, but not neomycin-induced, HC death. Regeneration depended on activation of Wnt signaling, and regeneration in DT-treated ears correlated to a higher level of Wnt activation than occurred in nonregenerating neomycin-treated ears. This is significant because insufficient

Essential Function of Dicer in Resolving DNA Damage in the Rapidly Dividing Cells of the Developing and Malignant Cerebellum

Directory of Open Access Journals (Sweden)

Vijay Swahari

2016-01-01

Full Text Available Maintenance of genomic integrity is critical during neurodevelopment, particularly in rapidly dividing cerebellar granule neuronal precursors that experience constitutive replication-associated DNA damage. As Dicer was recently recognized to have an unexpected function in the DNA damage response, we examined whether Dicer was important for preserving genomic integrity in the developing brain. We report that deletion of Dicer in the developing mouse cerebellum resulted in the accumulation of DNA damage leading to cerebellar progenitor degeneration, which was rescued with p53 deficiency; deletion of DGCR8 also resulted in similar DNA damage and cerebellar degeneration. Dicer deficiency also resulted in DNA damage and death in other rapidly dividing cells including embryonic stem cells and the malignant cerebellar progenitors in a mouse model of medulloblastoma. Together, these results identify an essential function of Dicer in resolving the spontaneous DNA damage that occurs during the rapid proliferation of developmental progenitors and malignant cells.

Inducing death in tumor cells: roles of the inhibitor of apoptosis proteins.

Science.gov (United States)

Finlay, Darren; Teriete, Peter; Vamos, Mitchell; Cosford, Nicholas D P; Vuori, Kristiina

2017-01-01

The heterogeneous group of diseases collectively termed cancer results not just from aberrant cellular proliferation but also from a lack of accompanying homeostatic cell death. Indeed, cancer cells regularly acquire resistance to programmed cell death, or apoptosis, which not only supports cancer progression but also leads to resistance to therapeutic agents. Thus, various approaches have been undertaken in order to induce apoptosis in tumor cells for therapeutic purposes. Here, we will focus our discussion on agents that directly affect the apoptotic machinery itself rather than on drugs that induce apoptosis in tumor cells indirectly, such as by DNA damage or kinase dependency inhibition. As the roles of the Bcl-2 family have been extensively studied and reviewed recently, we will focus in this review specifically on the inhibitor of apoptosis protein (IAP) family. IAPs are a disparate group of proteins that all contain a baculovirus IAP repeat domain, which is important for the inhibition of apoptosis in some, but not all, family members. We describe each of the family members with respect to their structural and functional similarities and differences and their respective roles in cancer. Finally, we also review the current state of IAPs as targets for anti-cancer therapeutics and discuss the current clinical state of IAP antagonists.

Molecular mechanisms in radiation damage to DNA. Progress report

International Nuclear Information System (INIS)

Osman, R.

1994-01-01

The objectives of this work are to elucidate the molecular mechanisms that are responsible for radiation-induced DNA damage. The overall goal is to understand the relationship between the chemical and structural changes produced by ionizing radiation in DNA and the resulting impairment of biological function expressed as carcinogenesis or cell death. The studies are based on theoretical explorations of possible mechanisms that link initial radiation damage in the form of base and sugar damage to conformational changes in DNA. These mechanistic explorations should lead to the formulation of testable hypotheses regarding the processes of impairment of regulation of gene expression, alteration in DNA repair, and damage to DNA structure involved in cell death or cancer

A review on radiation damage of erythrocyte membranes

International Nuclear Information System (INIS)

Wang Junling; Wang Weidong; Qin Guangyong

2007-01-01

Biomembrane has very important biological function. Its damage will seriously disturb the directivity, the orderly nature and coordination of cell metabolism, and finally causes the cell death. This paper reviewed the effects of radiation damage on erythrocyte membrane in membrane composition, membrane function and oxidation resistance system. (authors)

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.

alpha-Tocopheryl succinate promotes selective cell death induced by vitamin K3 in combination with ascorbate.

Science.gov (United States)

Tomasetti, M; Strafella, E; Staffolani, S; Santarelli, L; Neuzil, J; Guerrieri, R

2010-04-13

A strategy to reduce the secondary effects of anti-cancer agents is to potentiate the therapeutic effect by their combination. A combination of vitamin K3 (VK3) and ascorbic acid (AA) exhibited an anti-cancer synergistic effect, associated with extracellular production of H(2)O(2) that promoted cell death. The redox-silent vitamin E analogue alpha-tocopheryl succinate (alpha-TOS) was used in combination with VK3 and AA to evaluate their effect on prostate cancer cells. Prostate cancer cells were sensitive to alpha-TOS and VK3 treatment, but resistant to AA upto 3.2 mM. When combined, a synergistic effect was found for VK3-AA, whereas alpha-TOS-VK3 and alpha-TOS-AA combination showed an antagonist and additive effect, respectively. However, sub-lethal doses of AA-VK3 combination combined with a sub-toxic dose of alpha-TOS showed to induce efficient cell death that resembles autoschizis. Associated with this cell demise, lipid peroxidation, DNA damage, cytoskeleton alteration, lysosomal-mitochondrial perturbation, and release of cytochrome c without caspase activation were observed. Inhibition of lysosomal proteases did not attenuate cell death induced by the combined agents. Furthermore, cell deaths by apoptosis and autoschizis were detected. These finding support the emerging idea that synergistic combinations of some agents can overcome toxicity and other side-effects associated with high doses of single drugs creating the opportunity for therapeutically relevant selectivity.

Cell damage evaluation of mammalian cells in cell manipulation by amplified femtosecond ytterbium laser

Science.gov (United States)

Hong, Z.-Y.; Iino, T.; Hagihara, H.; Maeno, T.; Okano, K.; Yasukuni, R.; Hosokawa, Y.

2018-03-01

A micrometer-scale explosion with cavitation bubble generation is induced by focusing a femtosecond laser in an aqueous solution. We have proposed to apply the explosion as an impulsive force to manipulate mammalian cells especially in microfluidic chip. Herein, we employed an amplified femtosecond ytterbium laser as an excitation source for the explosion and evaluated cell damage in the manipulation process to clarify the application potential. The damage of C2C12 myoblast cell prepared as a representative mammalian cell was investigated as a function of distance between cell and laser focal point. Although the cell received strong damage on the direct laser irradiation condition, the damage sharply decreased with increasing distance. Since the threshold distance, above which the cell had no damage, was consistent with radius of the cavitation bubble, impact of the cavitation bubble would be a critical factor for the cell damage. The damage had strong nonlinearity in the pulse energy dependence. On the other hand, cell position shift by the impact of the cavitation bubble was almost proportional to the pulse energy. In balance between the cell viability and the cell position shift, we elucidated controllability of the cell manipulation in microfluidic chip.

Mitochondrial protection impairs BET bromodomain inhibitor-mediated cell death and provides rationale for combination therapeutic strategies.

Science.gov (United States)

Lasorsa, E; Smonksey, M; Kirk, J S; Rosario, S; Hernandez-Ilizaliturri, F J; Ellis, L

2015-12-10

Inhibitors of the bromodomain and extraterminal domain family (BETI) have recently entered phase I clinical trials. In patients with advanced leukemia's, potent antileukemia activity was displayed with minimum dose-limiting toxicity. In preclinical models of hematological malignancies, including aggressive B-cell lymphomas, BETI induced cell-cycle arrest and apoptosis. However, the underlying cell death mechanisms are still not well understood. Dissecting the mechanisms required by BETI to mediate cell death would provide strong direction on how to best utilize BETI to treat patients with aggressive hematological malignancies. Herein, we provide understanding of the molecular mechanisms underlying BETI-mediated cell death using I-BET762. Induction of cell death occurred in primary murine and human B-cell lymphomas through apoptosis. Genetic dissection using Eμ-myc B-cell lymphoma compound mutants demonstrated that I-BET762-induced apoptosis does not require the p53 pathway. Furthermore, deletion of Apaf1, and thus the absence of a functional apoptosome, is associated with a delayed drug response but do not provide long-term resistance. Prolonged treatment of this model in fact fails to suppress the therapeutic efficacy of the drug and is associated with biochemical features of autophagy. However, lack of mitochondrial permeability completely inhibited I-BET762-mediated tumor cell death, indicating mitochondrial damage as key events for its activity. Combination of I-BET762 with BH3-only mimetics ABT-263 or obatoclax, restored sensitivity to I-BET762 lymphoma killing; however, success was determined by expression of Bcl-2 family antiapoptotic proteins. Our study provides critical insight for clinical decisions regarding the appropriate strategy for using BETI as a single agent or in combination to treat patients with aggressive B-cell lymphomas.

EGFR-targeted plasmonic magnetic nanoparticles suppress lung tumor growth by abrogating G2/M cell-cycle arrest and inducing DNA damage

Directory of Open Access Journals (Sweden)

Kuroda S

2014-08-01

Full Text Available Shinji Kuroda,1 Justina Tam,2 Jack A Roth,1 Konstantin Sokolov,2 Rajagopal Ramesh3–5 1Department of Thoracic and Cardiovascular Surgery, 2Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA; 3Department of Pathology, 4Graduate Program in Biomedical Sciences, 5Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA Background: We have previously demonstrated the epidermal growth factor receptor (EGFR-targeted hybrid plasmonic magnetic nanoparticles (225-NP produce a therapeutic effect in human lung cancer cell lines in vitro. In the present study, we investigated the molecular mechanism of 225-NP-mediated antitumor activity both in vitro and in vivo using the EGFR-mutant HCC827 cell line. Methods: The growth inhibitory effect of 225-NP on lung tumor cells was determined by cell viability and cell-cycle analysis. Protein expression related to autophagy, apoptosis, and DNA-damage were determined by Western blotting and immunofluorescence. An in vivo efficacy study was conducted using a human lung tumor xenograft mouse model. Results: The 225-NP treatment markedly reduced tumor cell viability at 72 hours compared with the cell viability in control treatment groups. Cell-cycle analysis showed the percentage of cells in the G2/M phase was reduced when treated with 225-NP, with a concomitant increase in the number of cells in Sub-G1 phase, indicative of cell death. Western blotting showed LC3B and PARP cleavage, indicating 225-NP-treatment activated both autophagy- and apoptosis-mediated cell death. The 225-NP strongly induced γH2AX and phosphorylated histone H3, markers indicative of DNA damage and mitosis, respectively. Additionally, significant γH2AX foci formation was observed in 225-NP-treated cells compared with control treatment groups, suggesting 225-NP induced cell death by triggering DNA damage. The 225-NP-mediated DNA damage involved abrogation of the

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.

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

Directory of Open Access Journals (Sweden)

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.

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

DNA damage and autophagy

International Nuclear Information System (INIS)

Rodriguez-Rocha, Humberto; Garcia-Garcia, Aracely; Panayiotidis, Mihalis I.; Franco, Rodrigo

2011-01-01

Both exogenous and endogenous agents are a threat to DNA integrity. Exogenous environmental agents such as ultraviolet (UV) and ionizing radiation, genotoxic chemicals and endogenous byproducts of metabolism including reactive oxygen species can cause alterations in DNA structure (DNA damage). Unrepaired DNA damage has been linked to a variety of human disorders including cancer and neurodegenerative disease. Thus, efficient mechanisms to detect DNA lesions, signal their presence and promote their repair have been evolved in cells. If DNA is effectively repaired, DNA damage response is inactivated and normal cell functioning resumes. In contrast, when DNA lesions cannot be removed, chronic DNA damage triggers specific cell responses such as cell death and senescence. Recently, DNA damage has been shown to induce autophagy, a cellular catabolic process that maintains a balance between synthesis, degradation, and recycling of cellular components. But the exact mechanisms by which DNA damage triggers autophagy are unclear. More importantly, the role of autophagy in the DNA damage response and cellular fate is unknown. In this review we analyze evidence that supports a role for autophagy as an integral part of the DNA damage response.

Nek1 silencing slows down DNA repair and blocks DNA damage-induced cell cycle arrest.

Science.gov (United States)

Pelegrini, Alessandra Luíza; Moura, Dinara Jaqueline; Brenner, Bethânia Luise; Ledur, Pitia Flores; Maques, Gabriela Porto; Henriques, João Antônio Pegas; Saffi, Jenifer; Lenz, Guido

2010-09-01

Never in mitosis A (NIMA)-related kinases (Nek) are evolutionarily conserved proteins structurally related to the Aspergillus nidulans mitotic regulator NIMA. Nek1 is one of the 11 isoforms of the Neks identified in mammals. Different lines of evidence suggest the participation of Nek1 in response to DNA damage, which is also supported by the interaction of this kinase with proteins involved in DNA repair pathways and cell cycle regulation. In this report, we show that cells with Nek1 knockdown (KD) through stable RNA interference present a delay in DNA repair when treated with methyl-methanesulfonate (MMS), hydrogen peroxide (H(2)O(2)) and cisplatin (CPT). In particular, interstrand cross links induced by CPT take much longer to be resolved in Nek1 KD cells when compared to wild-type (WT) cells. In KD cells, phosphorylation of Chk1 in response to CPT was strongly reduced. While WT cells accumulate in G(2)/M after DNA damage with MMS and H(2)O(2), Nek1 KD cells do not arrest, suggesting that G(2)/M arrest induced by the DNA damage requires Nek1. Surprisingly, CPT-treated Nek1 KD cells arrest with a 4N DNA content similar to WT cells. This deregulation in cell cycle control in Nek1 KD cells leads to an increased sensitivity to genotoxic agents when compared to WT cells. These results suggest that Nek1 is involved in the beginning of the cellular response to genotoxic stress and plays an important role in preventing cell death induced by DNA damage.

Cytotoxicity of Portland cement with different radiopacifying agents: a cell death study.

Science.gov (United States)

Gomes Cornélio, Ana Lívia; Salles, Loise Pedrosa; Campos da Paz, Mariana; Cirelli, Joni Augusto; Guerreiro-Tanomaru, Juliane Maria; Tanomaru Filho, Mário

2011-02-01

The aim of this study was to investigate the cytotoxicity of white Portland cement (PC) alone or associated with bismuth oxide (PCBi), zirconium oxide (PCZir), and calcium tungstate (PCCa) in 2 cell lineages. Murine periodontal ligament cells (mPDL) and rat osteosarcoma cells (ROS 17/2.8) were exposed for 24 hours to specific concentrations of fresh PC and PC associations with radiopacifiers. Zinc oxide-eugenol cement and hydrogen peroxide treatment were applied as cytotoxic positive controls. Cell viability after incubation with the cements was assessed by mitochondrial dehydrogenase enzymatic assay. Cell morphology was microscopically analyzed by cresyl violet staining, and the mechanism of cell death was determined by acridine orange/ethidium bromide methodology. All data were analyzed statistically by analysis of variance and Tukey post hoc test (P cement elutes. PC alone was not cytotoxic, even at 100 mg/mL. Microscopic images showed that none of the PC formulations caused damage to any cell lines. Statistical analysis of apoptosis/necrosis data demonstrated that PC and PC plus radiopacifying agents promoted significant necrosis cell death only at 100 mg/mL. The mPDL cells were more sensitive than ROS17/2.8. The results showed that PC associated with bismuth oxide, zirconium oxide, or calcium tungstate is not cytotoxic to mPDL or ROS17/2.8. Zirconium oxide and calcium tungstate might be good alternatives as radiopacifying agents. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Tat-PRAS40 prevent hippocampal HT-22 cell death and oxidative stress induced animal brain ischemic insults.

Science.gov (United States)

Shin, Min Jea; Kim, Dae Won; Jo, Hyo Sang; Cho, Su Bin; Park, Jung Hwan; Lee, Chi Hern; Yeo, Eun Ji; Choi, Yeon Joo; Kim, Ji An; Hwang, Jung Soon; Sohn, Eun Jeong; Jeong, Ji-Heon; Kim, Duk-Soo; Kwon, Hyeok Yil; Cho, Yong-Jun; Lee, Keunwook; Han, Kyu Hyung; Park, Jinseu; Eum, Won Sik; Choi, Soo Young

2016-08-01

Proline rich Akt substrate (PRAS40) is a component of mammalian target of rapamycin complex 1 (mTORC1) and is known to play an important role against reactive oxygen species-induced cell death. However, the precise function of PRAS40 in ischemia remains unclear. Thus, we investigated whether Tat-PRAS40, a cell-permeable fusion protein, has a protective function against oxidative stress-induced hippocampal neuronal (HT-22) cell death in an animal model of ischemia. We showed that Tat-PRAS40 transduced into HT-22 cells, and significantly protected against cell death by reducing the levels of H2O2 and derived reactive species, and DNA fragmentation as well as via the regulation of Bcl-2, Bax, and caspase 3 expression levels in H2O2 treated cells. Also, we showed that transduced Tat-PARS40 protein markedly increased phosphorylated RRAS40 expression levels and 14-3-3σ complex via the Akt signaling pathway. In an animal ischemia model, Tat-PRAS40 effectively transduced into the hippocampus in animal brain and significantly protected against neuronal cell death in the CA1 region. We showed that Tat-PRAS40 protein effectively transduced into hippocampal neuronal cells and markedly protected against neuronal cell damage. Therefore, we suggest that Tat-PRAS40 protein may be used as a therapeutic protein for ischemia and oxidative stress-induced brain disorders. Copyright © 2016 Elsevier Inc. All rights reserved.

The Flaxseed-Derived Lignan Phenolic Secoisolariciresinol Diglucoside (SDG) Protects Non-Malignant Lung Cells from Radiation Damage.

Science.gov (United States)

Velalopoulou, Anastasia; Tyagi, Sonia; Pietrofesa, Ralph A; Arguiri, Evguenia; Christofidou-Solomidou, Melpo

2015-12-22

Plant phenolic compounds are common dietary antioxidants that possess antioxidant and anti-inflammatory properties. Flaxseed (FS) has been reported to be radioprotective in murine models of oxidative lung damage. Flaxseed's protective properties are attributed to its main biphenolic lignan, secoisolariciresinol diglucoside (SDG). SDG is a free radical scavenger, shown in cell free systems to protect DNA from radiation-induced damage. The objective of this study was to investigate the in vitro radioprotective efficacy of SDG in murine lung cells. Protection against irradiation (IR)-induced DNA double and single strand breaks was assessed by γ-H2AX labeling and alkaline comet assay, respectively. The role of SDG in modulating the levels of cytoprotective enzymes was evaluated by qPCR and confirmed by Western blotting. Additionally, effects of SDG on clonogenic survival of irradiated cells were evaluated. SDG protected cells from IR-induced death and ameliorated DNA damage by reducing mean comet tail length and percentage of γ-H2AX positive cells. Importantly, SDG significantly increased gene and protein levels of antioxidant HO-1, GSTM1 and NQO1. Our results identify the potent radioprotective properties of the synthetic biphenolic SDG, preventing DNA damage and enhancing the antioxidant capacity of normal lung cells; thus, rendering SDG a potential radioprotector against radiation exposure.

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

Cadmium Chloride Induces DNA Damage and Apoptosis of Human Liver Carcinoma Cells via Oxidative Stress

Directory of Open Access Journals (Sweden)

Anthony Skipper

2016-01-01

Full Text Available Cadmium is a heavy metal that has been shown to cause its toxicity in humans and animals. Many documented studies have shown that cadmium produces various genotoxic effects such as DNA damage and chromosomal aberrations. Ailments such as bone disease, renal damage, and several forms of cancer are attributed to overexposure to cadmium.  Although there have been numerous studies examining the effects of cadmium in animal models and a few case studies involving communities where cadmium contamination has occurred, its molecular mechanisms of action are not fully elucidated. In this research, we hypothesized that oxidative stress plays a key role in cadmium chloride-induced toxicity, DNA damage, and apoptosis of human liver carcinoma (HepG2 cells. To test our hypothesis, cell viability was determined by MTT assay. Lipid hydroperoxide content stress was estimated by lipid peroxidation assay. Genotoxic damage was tested by the means of alkaline single cell gel electrophoresis (Comet assay. Cell apoptosis was measured by flow cytometry assessment (Annexin-V/PI assay. The result of MTT assay indicated that cadmium chloride induces toxicity to HepG2 cells in a concentration-dependent manner, showing a 48 hr-LD50 of 3.6 µg/mL. Data generated from lipid peroxidation assay resulted in a significant (p < 0.05 increase of hydroperoxide production, specifically at the highest concentration tested. Data obtained from the Comet assay indicated that cadmium chloride causes DNA damage in HepG2 cells in a concentration-dependent manner. A strong concentration-response relationship (p < 0.05 was recorded between annexin V positive cells and cadmium chloride exposure. In summary, these in vitro studies provide clear evidence that cadmium chloride induces oxidative stress, DNA damage, and programmed cell death in human liver carcinoma (HepG2 cells.

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

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.

A Single Nucleotide Polymorphism in the Bax Gene Promoter Affects Transcription and Influences Retinal Ganglion Cell Death

Directory of Open Access Journals (Sweden)

Sheila J Semaan

2010-03-01

Full Text Available Pro-apoptotic Bax is essential for RGC (retinal ganglion cell death. Gene dosage experiments in mice, yielding a single wild-type Bax allele, indicated that genetic background was able to influence the cell death phenotype. DBA/2J Bax+/− mice exhibited complete resistance to nerve damage after 2 weeks (similar to Bax −/− mice, but 129B6 Bax+/− mice exhibited significant cell loss (similar to wild-type mice. The different cell death phenotype was associated with the level of Bax expression, where 129B6 neurons had twice the level of endogenous Bax mRNA and protein as DBA/2J neurons. Sequence analysis of the Bax promoters between these strains revealed a single nucleotide polymorphism (T129B6 to CDBA/2J at position −515. A 1.5- to 2.5-fold increase in transcriptional activity was observed from the 129B6 promoter in transient transfection assays in a variety of cell types, including RGC5 cells derived from rat RGCs. Since this polymorphism occurred in a p53 half-site, we investigated the requirement of p53 for the differential transcriptional activity. Differential transcriptional activity from either 129B6 or DBA/2J Bax promoters were unaffected in p53−/− cells, and addition of exogenous p53 had no further effect on this difference, thus a role for p53 was excluded. Competitive electrophoretic mobility-shift assays identified two DNA-protein complexes that interacted with the polymorphic region. Those forming Complex 1 bound with higher affinity to the 129B6 polymorphic site, suggesting that these proteins probably comprised a transcriptional activator complex. These studies implicated quantitative expression of the Bax gene as playing a possible role in neuronal susceptibility to damaging stimuli.

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.

Autophagy induced by purple pitanga (Eugenia uniflora L.) extract triggered a cooperative effect on inducing the hepatic stellate cell death.

Science.gov (United States)

Denardin, Cristiane C; Martins, Leo A M; Parisi, Mariana M; Vieira, Moema Queiroz; Terra, Silvia R; Barbé-Tuana, Florencia M; Borojevic, Radovan; Vizzotto, Márcia; Emanuelli, Tatiana; Guma, Fátima Costa Rodrigues

2017-04-01

Activated hepatic stellate cells (HSC) are the major source of collagen I in liver fibrosis. Eugenia uniflora L. is a tree species that is widely distributed in South America. E. uniflora L. fruit-popularly known as pitanga-has been shown to exert beneficial properties. Autophagy contributes to the maintenance of cellular homeostasis and survival under stress situation, but it has also been suggested to be an alternative cell death pathway. Mitochondria play a pivotal role on signaling cell death. Mitophagy of damaged mitochondria is an important cell defense mechanism against organelle-mediated cell death signaling. We previously found that purple pitanga extract induced mitochondrial dysfunction, cell cycle arrest, and death by apoptosis and necrosis in GRX cells, a well-established activated HSC line. We evaluated the effects of 72-h treatment with crescent concentrations of purple pitanga extract (5 to 100 μg/mL) on triggering autophagy in GRX cells, as this is an important mechanism to cells under cytotoxic conditions. We found that all treated cells presented an increase in the mRNA expression of autophagy-related protein 7 (ATG7). Concomitantly, flow cytometry and ultrastructural analysis of treated cells revealed an increase of autophagosomes/autolysosomes that consequentially led to an increased mitophagy. As purple pitanga extract was previously found to be broadly cytotoxic to GRX cells, we postulated that autophagy contributes to this scenario, where cell death seems to be an inevitable fate. Altogether, the effectiveness on inducing activated HSC death can make purple pitanga extract a good candidate on treating liver fibrosis.

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.

PKC 412 sensitizes U1810 non-small cell lung cancer cells to DNA damage

International Nuclear Information System (INIS)

Hemstroem, Therese H.; Joseph, Bertrand; Schulte, Gunnar; Lewensohn, Rolf; Zhivotovsky, Boris

2005-01-01

Non-small cell lung carcinoma (NSCLC) is characterized by resistance to drug-induced apoptosis, which might explain the survival of lung cancer cells following treatment. Recently we have shown that the broad-range kinase inhibitor staurosporine (STS) reactivates the apoptotic machinery in U1810 NSCLC cells [Joseph et al., Oncogene 21 (2002) 65]. Lately, several STS analogs that are more specific in kinase inhibition have been suggested for tumor treatment. In this study the apoptosis-inducing ability of the STS analogs PKC 412 and Ro 31-8220 used alone or in combination with DNA-damaging agents in U1810 cells was investigated. In these cells Ro 31-8220 neither induced apoptosis when used alone, nor sensitized cells to etoposide treatment. PKC 412 as a single agent induced death of a small number of U1810 cells, whereas it efficiently triggered a dose- and time-dependent apoptosis in U1285 small cell lung carcinoma cells. In both cell types PKC 412 triggered release of mitochondrial proteins followed by caspase activation. However, concomitant activation of a caspase-independent pathway was essential to kill NSCLC cells. Importantly, PKC 412 was able to sensitize etoposide- and radiation-induced death of U1810 cells. The best sensitization was achieved when PKC 412 was administered 24 h after treatments. In U1810 cells, Ro 31-8220 decreased PMA-induced ERK phosphorylation as efficiently as PKC 412, indicating that the failure of Ro 31-8220 to induce apoptosis was not due to weaker inhibition of conventional and novel PKC isoforms. However, Ro 31-8220 increased the basal level of ERK and Akt phosphorylation in both cell lines, whereas Akt phosphorylation was suppressed in the U1810 cells, which might influence apoptosis. These results suggest that PKC 412 could be a useful tool in increasing the efficiency of therapy of NSCLC

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.

The antineoplastic agent α-bisabolol promotes cell death by inducing pores in mitochondria and lysosomes.

Science.gov (United States)

Rigo, Antonella; Vinante, Fabrizio

2016-08-01

The sesquiterpene α-bisabolol (α-BSB) has been shown to be an effective cytotoxic agent for a variety of human cancer cells in culture and animal models. However, much of its intracellular action remains elusive. We evaluated the cytotoxic action of α-BSB against CML-T1, Jurkat and HeLa cell lines, as preclinical models for myeloid, lymphoid and epithelial neoplasias. The approach included single cell analysis (flow cytometry, immunocytology) combined with cytotoxicity and proliferation assays to characterize organelle damage, autophagy, cytostatic effect, and apoptosis. The study focuses on the relevant steps in the cytotoxic cascade triggered by α-BSB: (1) the lipid rafts through which α-BSB enters the cells, (2) the opening of pores in the mitochondria and lysosomes, (3) the activation of both caspase-dependent and caspase-independent cell death pathways, (4) the induction of autophagy and (5) apoptosis. The effectiveness of α-BSB as an agent against tumor cells is grounded on its capability to act on different layers of cell regulation to elicit different concurrent death signals, thereby neutralizing a variety of aberrant survival mechanisms leading to treatment resistance in neoplastic cell.

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.

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.

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

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

Propofol prevents autophagic cell death following oxygen and glucose deprivation in PC12 cells and cerebral ischemia-reperfusion injury in rats.

Directory of Open Access Journals (Sweden)

Derong Cui

Full Text Available Propofol exerts protective effects on neuronal cells, in part through the inhibition of programmed cell death. Autophagic cell death is a type of programmed cell death that plays elusive roles in controlling neuronal damage and metabolic homeostasis. We therefore studied whether propofol could attenuate the formation of autophagosomes, and if so, whether the inhibition of autophagic cell death mediates the neuroprotective effects observed with propofol.The cell model was established by depriving the cells of oxygen and glucose (OGD for 6 hours, and the rat model of ischemia was introduced by a transient two-vessel occlusion for 10 minutes. Transmission electron microscopy (TEM revealed that the formation of autophagosomes and autolysosomes in both neuronal PC12 cells and pyramidal rat hippocampal neurons after respective OGD and ischemia/reperfusion (I/R insults. A western blot analysis revealed that the autophagy-related proteins, such as microtubule-associated protein 1 light chain 3 (LC3-II, Beclin-1 and class III PI3K, were also increased accordingly, but cytoprotective Bcl-2 protein was decreased. The negative effects of OGD and I/R, including the formation of autophagosomes and autolysosomes, the increase in LC3-II, Beclin-1 and class III PI3K expression and the decline in Bcl-2 production were all inhibited by propofol and specific inhibitors of autophagy, such as 3-methyladenine (3-MA, LY294002 and Bafilomycin A1 (Baf,. Furthermore, in vitro OGD cultures and in vivo I/R rats showed an increase in cell survival following the administration of propofol, as assessed by an MTT assay or histochemical analyses.Our data suggest that propofol can markedly attenuate autophagic processes via the decreased expression of autophagy-related proteins in vitro and in vivo. This inhibition improves cell survival, which provides a novel explanation for the pleiotropic effects of propofol that benefit the nervous system.

Increasing RpoS expression causes cell death in Borrelia burgdorferi.

Directory of Open Access Journals (Sweden)

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.

Targeting Werner syndrome protein sensitizes U-2 OS osteosarcoma cells to selenium-induced DNA damage response and necrotic death

DEFF Research Database (Denmark)

Cheng, Wen-Hsing; Wu, Ryan T Y; Wu, Min

2012-01-01

to MSeA-induced necrotic death. Co-treatment with the ataxia-telangiectasia mutated (ATM) kinase inhibitor KU55933 desensitized the control shRNA cells, but not WRN shRNA cells, to MSeA treatment. WRN did not affect MSeA-induced ATM phosphorylation on Ser-1981 or H2A.X phosphorylation on Ser-139...

Vanadium toxicity in chickpea (Cicer arietinum L.) grown in red soil: Effects on cell death, ROS and antioxidative systems.

Science.gov (United States)

Imtiaz, Muhammad; Ashraf, Muhammad; Rizwan, Muhammad Shahid; Nawaz, Muhammad Amjad; Rizwan, Muhammad; Mehmood, Sajid; Yousaf, Balal; Yuan, Yuan; Ditta, Allah; Mumtaz, Muhammad Ali; Ali, Muhammad; Mahmood, Sammina; Tu, Shuxin

2018-04-17

The agricultural soil contaminated with heavy metals induces toxic effects on plant growth. The present study was conducted to evaluate the effects of vanadium (V) on growth, H 2 O 2 and enzyme activities, cell death, ion leakage, and at which concentration; V induces the toxic effects in chickpea plants grown in red soil. The obtained results indicated that the biomass (fresh and dry) and lengths of roots and shoots were significantly decreased by V application, and roots accumulated more V than shoots. The enzyme activities (SOD, CAT, and POD) and ion leakage were increased linearly with increasing V concentrations. However, the protein contents, and tolerance indices were significantly declined with the increasing levels of V. The results about the cell death indicated that the cell viability was badly damaged when plants were exposed to higher V, and induction of H 2 O 2 might be involved in this cell death. In conclusion, all the applied V levels affected the enzymatic activities, and induced the cell death of chickpea plants. Furthermore, our results also confirmed that vanadium ≥ 130 mg kg -1 induced detrimental effects on chickpea plants. Additional investigation is needed to clarify the mechanistic explanations of V toxicity at the molecular level and gene expression involved in plant cell death. Copyright © 2018 Elsevier Inc. All rights reserved.

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.

Harnessing the p53-PUMA Axis to Overcome DNA Damage Resistance in Renal Cell Carcinoma

Directory of Open Access Journals (Sweden)

Xiaoguang Zhou

2014-12-01

Full Text Available Resistance to DNA damage–induced apoptosis is a hallmark of cancer and a major cause of treatment failure and lethal disease outcome. A tumor entity that is largely resistant to DNA-damaging therapies including chemo- or radiotherapy is renal cell carcinoma (RCC. This study was designed to explore the underlying molecular mechanisms of DNA damage resistance in RCC to develop strategies to resensitize tumor cells to DNA damage–induced apoptosis. Here, we show that apoptosis-resistant RCC cells have a disconnect between activation of p53 and upregulation of the downstream proapoptotic protein p53 upregulated modulator of apoptosis (PUMA. We demonstrate that this disconnect is not caused by gene-specific repression through CCCTC-binding factor (CTCF but instead by aberrant chromatin compaction. Treatment with an HDAC inhibitor was found to effectively reactivate PUMA expression on the mRNA and protein level and to revert resistance to DNA damage–induced cell death. Ectopic expression of PUMA was found to resensitize a panel of RCC cell lines to four different DNA-damaging agents tested. Remarkably, all RCC cell lines analyzed were wild-type for p53, and a knockdown was likewise able to sensitize RCC cells to acute genotoxic stress. Taken together, our results indicate that DNA damage resistance in RCC is reversible, involves the p53-PUMA axis, and is potentially targetable to improve the oncological outcomes of RCC patients.

Amelioration of streptozotocin‑induced pancreatic β cell damage by morin: Involvement of the AMPK‑FOXO3‑catalase signaling pathway.

Science.gov (United States)

Wang, Ning; Zhang, Jiahui; Qin, Mengting; Yi, Wenjing; Yu, Shuang; Chen, Yi; Guan, Jing; Zhang, Rui

2018-03-01

Pancreatic β cells are sensitive to oxidative stress, which is one of the predominant causes of cell damage and the emergence of diabetes. The identification of effective therapeutic strategies to protect pancreatic cells from oxidative stress has increased interest in the screening of antioxidants from natural products. The present study aimed to investigate the protective effects of morin against streptozotocin (STZ)‑induced cell damage in a rat insulinoma cell line (RINm5F pancreatic β cells) and to identify the underlying mechanisms. The results indicated that morin inhibited the increase in intracellular reactive oxygen species, attenuated the activity of poly (ADP‑ribose) polymerase, restored intracellular nicotinamide adenine dinucleotide levels and reduced the apoptotic cell death of STZ‑treated pancreatic β cells. Treatment with morin significantly upregulated catalase in pancreatic β cells, and ameliorated the STZ‑induced loss of catalase at the genetic, protein and enzymatic level. In further experiments, morin induced the phosphorylation of 5' adenosine monophosphate‑activated protein kinase (AMPK), which subsequently promoted the translocation of forkhead box O3 (FOXO3) to the nucleus. Specific small interfering RNAs (siRNAs) against AMPK and FOXO3 suppressed morin‑induced catalase expression. Furthermore, catalase‑specific siRNA abolished the protective effects of morin against STZ‑stimulated cell death. Taken together, these results indicated that morin protected RINm5F cells from STZ‑induced cell damage by triggering the phosphorylation of AMPK, thus resulting in subsequent activation of FOXO3 and induction of catalase.

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

Apricot melanoidins prevent oxidative endothelial cell death by counteracting mitochondrial oxidation and membrane depolarization.

Directory of Open Access Journals (Sweden)

Annalisa Cossu

Full Text Available The cardiovascular benefits associated with diets rich in fruit and vegetables are thought to be due to phytochemicals contained in fresh plant material. However, whether processed plant foods provide the same benefits as unprocessed ones is an open question. Melanoidins from heat-processed apricots were isolated and their presence confirmed by colorimetric analysis and browning index. Oxidative injury of endothelial cells (ECs is the key step for the onset and progression of cardiovascular diseases (CVD, therefore the potential protective effect of apricot melanoidins on hydrogen peroxide-induced oxidative mitochondrial damage and cell death was explored in human ECs. The redox state of cytoplasmic and mitochondrial compartments was detected by using the redox-sensitive, fluorescent protein (roGFP, while the mitochondrial membrane potential (MMP was assessed with the fluorescent dye, JC-1. ECs exposure to hydrogen peroxide, dose-dependently induced mitochondrial and cytoplasmic oxidation. Additionally detected hydrogen peroxide-induced phenomena were MMP dissipation and ECs death. Pretreatment of ECs with apricot melanoidins, significantly counteracted and ultimately abolished hydrogen peroxide-induced intracellular oxidation, mitochondrial depolarization and cell death. In this regard, our current results clearly indicate that melanoidins derived from heat-processed apricots, protect human ECs against oxidative stress.

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.

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

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.

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.

Chronic inflammatory cells and damaged limbal cells in pterygium ...

African Journals Online (AJOL)

Background: Chronic inflammation in pterygium occurrence has not been explained. Whether damaged limbal basal epithelial cells are associated with pterygium occurrence in black Africans is not clear. Objective: To explain chronic inflammation in pterygium, and to clarify whether damaged limbal basal epithelial cells ...

Repair of radiation damage in mammalian cells

Energy Technology Data Exchange (ETDEWEB)

Setlow, R.B.

1981-01-01

The responses, such as survival, mutation, and carcinogenesis, of mammalian cells and tissues to radiation are dependent not only on the magnitude of the damage to macromolecular structures - DNA, RNA, protein, and membranes - but on the rates of macromolecular syntheses of cells relative to the half-lives of the damages. Cells possess a number of mechanisms for repairing damage to DNA. If the repair systems are rapid and error free, cells can tolerate much larger doses than if repair is slow or error prone. It is important to understand the effects of radiation and the repair of radiation damage because there exist reasonable amounts of epidemiological data that permits the construction of dose-response curves for humans. The shapes of such curves or the magnitude of the response will depend on repair. Radiation damage is emphasized because: (a) radiation dosimetry, with all its uncertainties for populations, is excellent compared to chemical dosimetry; (b) a number of cancer-prone diseases are known in which there are defects in DNA repair and radiation results in more chromosomal damage in cells from such individuals than in cells from normal individuals; (c) in some cases, specific radiation products in DNA have been correlated with biological effects, and (d) many chemical effects seem to mimic radiation effects. A further reason for emphasizing damage to DNA is the wealth of experimental evidence indicating that damages to DNA can be initiating events in carcinogenesis.

Repair of radiation damage in mammalian cells

International Nuclear Information System (INIS)

Setlow, R.B.

1981-01-01

The responses, such as survival, mutation, and carcinogenesis, of mammalian cells and tissues to radiation are dependent not only on the magnitude of the damage to macromolecular structures - DNA, RNA, protein, and membranes - but on the rates of macromolecular syntheses of cells relative to the half-lives of the damages. Cells possess a number of mechanisms for repairing damage to DNA. If the repair systems are rapid and error free, cells can tolerate much larger doses than if repair is slow or error prone. It is important to understand the effects of radiation and the repair of radiation damage because there exist reasonable amounts of epidemiological data that permits the construction of dose-response curves for humans. The shapes of such curves or the magnitude of the response will depend on repair. Radiation damage is emphasized because: (a) radiation dosimetry, with all its uncertainties for populations, is excellent compared to chemical dosimetry; (b) a number of cancer-prone diseases are known in which there are defects in DNA repair and radiation results in more chromosomal damage in cells from such individuals than in cells from normal individuals; (c) in some cases, specific radiation products in DNA have been correlated with biological effects, and (d) many chemical effects seem to mimic radiation effects. A further reason for emphasizing damage to DNA is the wealth of experimental evidence indicating that damages to DNA can be initiating events in carcinogenesis

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.

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

The Flaxseed-Derived Lignan Phenolic Secoisolariciresinol Diglucoside (SDG Protects Non-Malignant Lung Cells from Radiation Damage

Directory of Open Access Journals (Sweden)

Anastasia Velalopoulou

2015-12-01

Full Text Available Plant phenolic compounds are common dietary antioxidants that possess antioxidant and anti-inflammatory properties. Flaxseed (FS has been reported to be radioprotective in murine models of oxidative lung damage. Flaxseed’s protective properties are attributed to its main biphenolic lignan, secoisolariciresinol diglucoside (SDG. SDG is a free radical scavenger, shown in cell free systems to protect DNA from radiation-induced damage. The objective of this study was to investigate the in vitro radioprotective efficacy of SDG in murine lung cells. Protection against irradiation (IR-induced DNA double and single strand breaks was assessed by γ-H2AX labeling and alkaline comet assay, respectively. The role of SDG in modulating the levels of cytoprotective enzymes was evaluated by qPCR and confirmed by Western blotting. Additionally, effects of SDG on clonogenic survival of irradiated cells were evaluated. SDG protected cells from IR-induced death and ameliorated DNA damage by reducing mean comet tail length and percentage of γ-H2AX positive cells. Importantly, SDG significantly increased gene and protein levels of antioxidant HO-1, GSTM1 and NQO1. Our results identify the potent radioprotective properties of the synthetic biphenolic SDG, preventing DNA damage and enhancing the antioxidant capacity of normal lung cells; thus, rendering SDG a potential radioprotector against radiation exposure.

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.

miR-181a and miR-630 regulate cisplatin-induced cancer cell death.

Science.gov (United States)

Galluzzi, Lorenzo; Morselli, Eugenia; Vitale, Ilio; Kepp, Oliver; Senovilla, Laura; Criollo, Alfredo; Servant, Nicolas; Paccard, Caroline; Hupé, Philippe; Robert, Thomas; Ripoche, Hugues; Lazar, Vladimir; Harel-Bellan, Annick; Dessen, Philippe; Barillot, Emmanuel; Kroemer, Guido

2010-03-01

MicroRNAs (miRNA) are noncoding RNAs that regulate multiple cellular processes, including proliferation and apoptosis. We used microarray technology to identify miRNAs that were upregulated by non-small cell lung cancer (NSCLC) A549 cells in response to cisplatin (CDDP). The corresponding synthetic miRNA precursors (pre-miRNAs) per se were not lethal when transfected into A549 cells yet affected cell death induction by CDDP, C2-ceramide, cadmium, etoposide, and mitoxantrone in an inducer-specific fashion. Whereas synthetic miRNA inhibitors (anti-miRNAs) targeting miR-181a and miR-630 failed to modulate the response of A549 to CDDP, pre-miR-181a and pre-miR-630 enhanced and reduced CDDP-triggered cell death, respectively. Pre-miR-181a and pre-miR-630 consistently modulated mitochondrial/postmitochondrial steps of the intrinsic pathway of apoptosis, including Bax oligomerization, mitochondrial transmembrane potential dissipation, and the proteolytic maturation of caspase-9 and caspase-3. In addition, pre-miR-630 blocked early manifestations of the DNA damage response, including the phosphorylation of the ataxia-telangiectasia mutated (ATM) kinase and of two ATM substrates, histone H2AX and p53. Pharmacologic and genetic inhibition of p53 corroborated the hypothesis that pre-miR-630 (but not pre-miR-181a) blocks the upstream signaling pathways that are ignited by DNA damage and converge on p53 activation. Pre-miR-630 arrested A549 cells in the G0-G1 phase of the cell cycle, correlating with increased levels of the cell cycle inhibitor p27(Kip1) as well as with reduced proliferation rates and resulting in greatly diminished sensitivity of A549 cells to the late S-G2-M cell cycle arrest mediated by CDDP. Altogether, these results identify miR-181a and miR-630 as novel modulators of the CDDP response in NSCLC.

Tat-antioxidant 1 protects against stress-induced hippocampal HT-22 cells death and attenuate ischaemic insult in animal model.

Science.gov (United States)

Kim, So Mi; Hwang, In Koo; Yoo, Dae Young; Eum, Won Sik; Kim, Dae Won; Shin, Min Jea; Ahn, Eun Hee; Jo, Hyo Sang; Ryu, Eun Ji; Yong, Ji In; Cho, Sung-Woo; Kwon, Oh-Shin; Lee, Keun Wook; Cho, Yoon Shin; Han, Kyu Hyung; Park, Jinseu; Choi, Soo Young

2015-06-01

Oxidative stress-induced reactive oxygen species (ROS) are responsible for various neuronal diseases. Antioxidant 1 (Atox1) regulates copper homoeostasis and promotes cellular antioxidant defence against toxins generated by ROS. The roles of Atox1 protein in ischaemia, however, remain unclear. In this study, we generated a protein transduction domain fused Tat-Atox1 and examined the roles of Tat-Atox1 in oxidative stress-induced hippocampal HT-22 cell death and an ischaemic injury animal model. Tat-Atox1 effectively transduced into HT-22 cells and it protected cells against the effects of hydrogen peroxide (H2O2)-induced toxicity including increasing of ROS levels and DNA fragmentation. At the same time, Tat-Atox1 regulated cellular survival signalling such as p53, Bad/Bcl-2, Akt and mitogen-activate protein kinases (MAPKs). In the animal ischaemia model, transduced Tat-Atox1 protected against neuronal cell death in the hippocampal CA1 region. In addition, Tat-Atox1 significantly decreased the activation of astrocytes and microglia as well as lipid peroxidation in the CA1 region after ischaemic insult. Taken together, these results indicate that transduced Tat-Atox1 protects against oxidative stress-induced HT-22 cell death and against neuronal damage in animal ischaemia model. Therefore, we suggest that Tat-Atox1 has potential as a therapeutic agent for the treatment of oxidative stress-induced ischaemic damage. © 2015 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

Alpha-phellandrene-induced DNA damage and affect DNA repair protein expression in WEHI-3 murine leukemia cells in vitro.

Science.gov (United States)

Lin, Jen-Jyh; Wu, Chih-Chung; Hsu, Shu-Chun; Weng, Shu-Wen; Ma, Yi-Shih; Huang, Yi-Ping; Lin, Jaung-Geng; Chung, Jing-Gung

2015-11-01

Although there are few reports regarding α-phellandrene (α-PA), a natural compound from Schinus molle L. essential oil, there is no report to show that α-PA induced DNA damage and affected DNA repair associated protein expression. Herein, we investigated the effects of α-PA on DNA damage and repair associated protein expression in murine leukemia cells. Flow cytometric assay was used to measure the effects of α-PA on total cell viability and the results indicated that α-PA induced cell death. Comet assay and 4,6-diamidino-2-phenylindole dihydrochloride staining were used for measuring DNA damage and condensation, respectively, and the results indicated that α-PA induced DNA damage and condensation in a concentration-dependent manner. DNA gel electrophoresis was used to examine the DNA damage and the results showed that α-PA induced DNA damage in WEHI-3 cells. Western blotting assay was used to measure the changes of DNA damage and repair associated protein expression and the results indicated that α-PA increased p-p53, p-H2A.X, 14-3-3-σ, and MDC1 protein expression but inhibited the protein of p53, MGMT, DNA-PK, and BRCA-1. © 2014 Wiley Periodicals, Inc.

The relationships between RBE and LET for different types of lethal damage in mammalian cells: biophysical and molecular mechanisms

NARCIS (Netherlands)

Barendsen, G. W.

1994-01-01

The relative biological effectiveness (RBE) of radiations as a function of linear energy transfer (LET) is analyzed for different types of damage causing reproductive death of mammalian cells. Survival curves are evaluated assuming a linear-quadratic dose dependence of the induction of reproductive

DNA damage response in nephrotoxic and ischemic kidney injury

Energy Technology Data Exchange (ETDEWEB)

Yan, Mingjuan; Tang, Chengyuan [Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011 (China); Ma, Zhengwei [Department of Cellular Biology & Anatomy, Medical College of Georgia at Augusta University and Charlie Norwood VA Medical Center, Augusta, GA 30912 (United States); Huang, Shuang [Department of Anatomy and Cell Biology, University of Florida College of Medicine, Gainesville, FL (United States); Dong, Zheng, E-mail: zdong@augusta.edu [Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011 (China); Department of Cellular Biology & Anatomy, Medical College of Georgia at Augusta University and Charlie Norwood VA Medical Center, Augusta, GA 30912 (United States)

2016-12-15

DNA damage activates specific cell signaling cascades for DNA repair, cell cycle arrest, senescence, and/or cell death. Recent studies have demonstrated DNA damage response (DDR) in experimental models of acute kidney injury (AKI). In cisplatin-induced AKI or nephrotoxicity, the DDR pathway of ATR/Chk2/p53 is activated and contributes to renal tubular cell apoptosis. In ischemic AKI, DDR seems more complex and involves at least the ataxia telangiectasia mutated (ATM), a member of the phosphatidylinositol 3-kinase-related kinase (PIKK) family, and p53; however, while ATM may promote DNA repair, p53 may trigger cell death. Targeting DDR for kidney protection in AKI therefore relies on a thorough elucidation of the DDR pathways in various forms of AKI.

Neuroprotective effects of corn silk maysin via inhibition of H2O2-induced apoptotic cell death in SK-N-MC cells.

Science.gov (United States)

Choi, Doo Jin; Kim, Sun-Lim; Choi, Ji Won; Park, Yong Il

2014-07-25

Neuroprotective effects of maysin, which is a flavone glycoside that was isolated from the corn silk (CS, Zea mays L.) of a Korean hybrid corn Kwangpyeongok, against oxidative stress (H2O2)-induced apoptotic cell death of human neuroblastoma SK-N-MC cells were investigated. Maysin cytotoxicity was determined by measuring cell viability using MTT and lactate dehydrogenase (LDH) assays. Intracellular reactive oxygen species (ROS) were measured using a 2,7-dichlorofluorescein diacetate (DCF-DA) assay. Apoptotic cell death was monitored by annexin V-FITC/PI double staining and by a TUNEL assay. Antioxidant enzyme mRNA levels were determined by real-time PCR. The cleavage of poly (ADP-ribose) polymerase (PARP) was measured by western blotting. Maysin pretreatment reduced the cytotoxic effect of H2O2 on SK-N-MC cells, as shown by the increase in cell viability and by reduced LDH release. Maysin pretreatment also dose-dependently reduced the intracellular ROS level and inhibited PARP cleavage. In addition, DNA damage and H2O2-induced apoptotic cell death were significantly attenuated by maysin pretreatment. Moreover, maysin pretreatment (5-50 μg/ml) for 2h significantly and dose-dependently increased the mRNA levels of antioxidant enzymes (CAT, GPx-1, SOD-1, SOD-2 and HO-1) in H2O2 (200 μM)-insulted cells. These results suggest that CS maysin has neuroprotective effects against oxidative stress (H2O2)-induced apoptotic death of human brain SK-N-MC cells through its antioxidative action. This report is the first regarding neuroprotective health benefits of corn silk maysin by its anti-apoptotic action and by triggering the expression of intracellular antioxidant enzyme systems in SK-N-MC cells. Copyright © 2014 Elsevier Inc. All rights reserved.

The serine protease inhibitor TLCK attenuates intrinsic death pathways in neurons upstream of mitochondrial demise.

Science.gov (United States)

Reuther, C; Ganjam, G K; Dolga, A M; Culmsee, C

2014-11-01

It is well-established that activation of proteases, such as caspases, calpains and cathepsins are essential components in signaling pathways of programmed cell death (PCD). Although these proteases have also been linked to mechanisms of neuronal cell death, they are dispensable in paradigms of intrinsic death pathways, e.g. induced by oxidative stress. However, emerging evidence implicated a particular role for serine proteases in mechanisms of PCD in neurons. Here, we investigated the role of trypsin-like serine proteases in a model of glutamate toxicity in HT-22 cells. In these cells glutamate induces oxytosis, a form of caspase-independent cell death that involves activation of the pro-apoptotic protein BH3 interacting-domain death agonist (Bid), leading to mitochondrial demise and ensuing cell death. In this model system, the trypsin-like serine protease inhibitor Nα-tosyl-l-lysine chloromethyl ketone hydrochloride (TLCK) inhibited mitochondrial damage and cell death. Mitochondrial morphology alterations, the impairment of the mitochondrial membrane potential and ATP depletion were prevented and, moreover, lipid peroxidation induced by glutamate was completely abolished. Strikingly, truncated Bid-induced cell death was not affected by TLCK, suggesting a detrimental activity of serine proteases upstream of Bid activation and mitochondrial demise. In summary, this study demonstrates the protective effect of serine protease inhibition by TLCK against oxytosis-induced mitochondrial damage and cell death. These findings indicate that TLCK-sensitive serine proteases play a crucial role in cell death mechanisms upstream of mitochondrial demise and thus, may serve as therapeutic targets in diseases, where oxidative stress and intrinsic pathways of PCD mediate neuronal cell death.

Magnetic Hyperthermia and Oxidative Damage to DNA of Human Hepatocarcinoma Cells.

Science.gov (United States)

Cellai, Filippo; Munnia, Armelle; Viti, Jessica; Doumett, Saer; Ravagli, Costanza; Ceni, Elisabetta; Mello, Tommaso; Polvani, Simone; Giese, Roger W; Baldi, Giovanni; Galli, Andrea; Peluso, Marco E M

2017-04-29

Nanotechnology is addressing major urgent needs for cancer treatment. We conducted a study to compare the frequency of 3-(2-deoxy-β-d-erythro-pentafuranosyl)pyrimido[1,2-α]purin-10(3 H )-one deoxyguanosine (M₁dG) and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) adducts, biomarkers of oxidative stress and/or lipid peroxidation, on human hepatocarcinoma HepG2 cells exposed to increasing levels of Fe₃O₄-nanoparticles (NPs) versus untreated cells at different lengths of incubations, and in the presence of increasing exposures to an alternating magnetic field (AMF) of 186 kHz using 32 P-postlabeling. The levels of oxidative damage tended to increase significantly after ≥24 h of incubations compared to controls. The oxidative DNA damage tended to reach a steady-state after treatment with 60 μg/mL of Fe₃O₄-NPs. Significant dose-response relationships were observed. A greater adduct production was observed after magnetic hyperthermia, with the highest amounts of oxidative lesions after 40 min exposure to AMF. The effects of magnetic hyperthermia were significantly increased with exposure and incubation times. Most important, the levels of oxidative lesions in AMF exposed NP treated cells were up to 20-fold greater relative to those observed in nonexposed NP treated cells. Generation of oxidative lesions may be a mechanism by which magnetic hyperthermia induces cancer cell death.

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

[Sea urchin embryo, DNA-damaged cell cycle checkpoint and the mechanisms initiating cancer development].

Science.gov (United States)

Bellé, Robert; Le Bouffant, Ronan; Morales, Julia; Cosson, Bertrand; Cormier, Patrick; Mulner-Lorillon, Odile

2007-01-01

Cell division is an essential process for heredity, maintenance and evolution of the whole living kingdom. Sea urchin early development represents an excellent experimental model for the analysis of cell cycle checkpoint mechanisms since embryonic cells contain a functional DNA-damage checkpoint and since the whole sea urchin genome is sequenced. The DNA-damaged checkpoint is responsible for an arrest in the cell cycle when DNA is damaged or incorrectly replicated, for activation of the DNA repair mechanism, and for commitment to cell death by apoptosis in the case of failure to repair. New insights in cancer biology lead to two fundamental concepts about the very first origin of cancerogenesis. Cancers result from dysfunction of DNA-damaged checkpoints and cancers appear as a result of normal stem cell (NCS) transformation into a cancer stem cell (CSC). The second aspect suggests a new definition of "cancer", since CSC can be detected well before any clinical evidence. Since early development starts from the zygote, which is a primary stem cell, sea urchin early development allows analysis of the early steps of the cancerization process. Although sea urchins do not develop cancers, the model is alternative and complementary to stem cells which are not easy to isolate, do not divide in a short time and do not divide synchronously. In the field of toxicology and incidence on human health, the sea urchin experimental model allows assessment of cancer risk from single or combined molecules long before any epidemiologic evidence is available. Sea urchin embryos were used to test the worldwide used pesticide Roundup that contains glyphosate as the active herbicide agent; it was shown to activate the DNA-damage checkpoint of the first cell cycle of development. The model therefore allows considerable increase in risk evaluation of new products in the field of cancer and offers a tool for the discovery of molecular markers for early diagnostic in cancer biology

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...

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

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.

Radiation-induced damage of membranes

International Nuclear Information System (INIS)

Yonei, Shuji

1977-01-01

An outline of membranous structure was stated, and radiation-induced damage of membranes were surveyed. By irradiation, permeability of membranes, especially passive transportation mechanism, was damaged, and glycoprotein in the surface layers of cells and the surface layer structures were changed. The intramembranous damage was induced by decrease of electrophoresis of nuclear mambranes and a quantitative change of cytochrome P450 of microsomal membranes of the liver, and peroxidation of membranous lipid and SH substitute damage of membranous protein were mentioned as the mechanism of membranous damage. Recovery of membranous damage depends on radiation dose and temperature, and membranous damage participates largely in proliferation death. (tsunoda, M.)

The machinery of Nod-like receptors: refining the paths to immunity and cell death.

Science.gov (United States)

Saleh, Maya

2011-09-01

One of the fundamental aspects of the innate immune system is its capacity to discriminate between self and non-self or altered self, and to quickly respond by eliciting effector mechanisms that act in concert to restore normalcy. This capacity is determined by a set of evolutionarily conserved pattern recognition receptors (PRRs) that sense the presence of microbial motifs or endogenous danger signals, including tissue damage, cellular transformation or metabolic perturbation, and orchestrate the nature, duration and intensity of the innate immune response. Nod-like receptors (NLRs), a group of intracellular PRRs, are particularly essential as evident by the high incidence of genetic variations in their genes in various diseases of homeostasis. Here, I overview the signaling mechanisms of NLRs and discuss the mounting evidence of evolutionary conservation between their pathways and the cell death machinery. I also describe their effector functions that link the sensing of danger to the induction of inflammation, autophagy or cell death. © 2011 John Wiley & Sons A/S.

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.

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.

[Linezolid-induced Apoptosis through Mitochondrial Damage and Role of Superoxide Dismutase-1 in Human Monocytic Cell Line U937].

Science.gov (United States)

Fujii, Satoshi; Muraoka, Sanae; Miyamoto, Atsushi; Sakurai, Koichi

2018-01-01

 Cytopenia is a major adverse event associated with linezolid therapy. The objective of this study was to examine whether the cytotoxicity of linezolid to eukaryotic cells was associated with mitochondrial dysfunction and apoptosis-like cell death in human leukemic monocyte lymphoma cell line U937. Apoptosis-like cell death was clearly observed when cells were incubated with linezolid, depending on the duration and linezolid concentration. Mitochondrial membrane potential of cells treated with linezolid collapsed in a short period of time, but the number of mitochondria did not decrease. Cytotoxicity of linezolid was relieved by the knockdown of superoxide dismutase-1 in U937 cells. On the other hand, no autophagy was observed in cells treated with linezolid. These results suggest that mitochondrial damages would be linked to the induction of apoptosis in U937 cells treated with linezolid and that its mechanism does not involve autophagy.

Salubrinal protects human skin fibroblasts against UVB-induced cell death by blocking endoplasmic reticulum (ER) stress and regulating calcium homeostasis.

Science.gov (United States)

Ji, Chao; Yang, Bo; Huang, Shu-Ying; Huang, Jin-Wen; Cheng, Bo

2017-12-02

The role of UVB in skin photo damages has been widely reported. Overexposure to UVB will induce severe DNA damages in epidermal cells and cause most cytotoxic symptoms. In the present study, we tested the potential activity of salubrinal, a selective inhibitor of Eukaryotic Initiation Factor 2 (eIF2) -alpha phosphatase, against UV-induced skin cell damages. We first exposed human fibroblasts to UVB radiation and evaluated the cytosolic Ca 2+ level as well as the induction of ER stress. We found that UVB radiation induced the depletion of ER Ca 2+ and increased the expression of ER stress marker including phosphorylated PERK, CHOP, and phosphorylated IRE1α. We then determined the effects of salubrinal in skin cell death induced by UVB radiation. We observed that cells pre-treated with salubrinal had a higher survival rate compared to cells treated with UVB alone. Pre-treatment with salubrinal successfully re-established the ER function and Ca 2+ homeostasis. Our results suggest that salubrinal can be a potential therapeutic agents used in preventing photoaging and photo damages. Copyright © 2017 Elsevier Inc. All rights reserved.

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

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.)

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.

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)

Phytometabolite Dehydroleucodine Induces Cell Cycle Arrest, Apoptosis, and DNA Damage in Human Astrocytoma Cells through p73/p53 Regulation.

Science.gov (United States)

Bailon-Moscoso, Natalia; González-Arévalo, Gabriela; Velásquez-Rojas, Gabriela; Malagon, Omar; Vidari, Giovanni; Zentella-Dehesa, Alejandro; Ratovitski, Edward A; Ostrosky-Wegman, Patricia

2015-01-01

Accumulating evidence supports the idea that secondary metabolites obtained from medicinal plants (phytometabolites) may be important contributors in the development of new chemotherapeutic agents to reduce the occurrence or recurrence of cancer. Our study focused on Dehydroleucodine (DhL), a sesquiterpene found in the provinces of Loja and Zamora-Chinchipe. In this study, we showed that DhL displayed cytostatic and cytotoxic activities on the human cerebral astrocytoma D384 cell line. With lactone isolated from Gynoxys verrucosa Wedd, a medicinal plant from Ecuador, we found that DhL induced cell death in D384 cells by triggering cell cycle arrest and inducing apoptosis and DNA damage. We further found that the cell death resulted in the increased expression of CDKN1A and BAX proteins. A marked induction of the levels of total TP73 and phosphorylated TP53, TP73, and γ-H2AX proteins was observed in D384 cells exposed to DhL, but no increase in total TP53 levels was detected. Overall these studies demonstrated the marked effect of DhL on the diminished survival of human astrocytoma cells through the induced expression of TP73 and phosphorylation of TP73 and TP53, suggesting their key roles in the tumor cell response to DhL treatment.

Apatone® induces endometrioid ovarian carcinoma (MDAH 2774 cells to undergo karyolysis and cell death by autoschizis: A potent and safe anticancer treatment

Directory of Open Access Journals (Sweden)

Jacques Gilloteaux

2015-12-01

Full Text Available Ovarian cancers are still the most lethal gynecologic malignancy. As a novel strategy against this poor outcome cytotoxic alterations induced by a pro-oxidant treatment on human ovarian endometrioid carcinoma (MDAH 2774 cells are revisited by using light, scanning and transmission electron microscopy. A series of sequential and concomitant cellular and organelle injuries induced by ascorbate: menadione combination (VC: VK3 or Apatone® is emphasized. This adjuvant or treatment is able to kill majority of these tumor cells through ‘autoschizic cell death’, a mode of cell death different than apoptosis. Autoschizic cell death is significant after a short period of treatment to decrease the ovarian tumor cell population through induced injuries that proceed from membranes to most organelles: karyolysis with nucleolar segregation and fragmentation, autophagy of mitochondria, lysosome and other organelles as well as cytoskeletal defects. The cytoskeletal damages are evidenced by morphology changes that included auto- or self-excised pieces of cytoplasm lacking organelles apparently facilitated by grouping of vacuolated endoplasm. These results obtained against this endometrioid ovary cell line are comforted by other studies using Apatone® against other carcinomas in vitro and in vivo. Altogether these reports support Apatone® as a new drug that can favorably be used as a novel potent, safe, and inexpensive clinical adjuvant or treatment against ovarian cancers. Keywords: Ascorbate, Menadione, Endometrioid ovarian cancer MDAH 2774, Autoschizis cell death, DNA

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.