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Sample records for cells undergoing apoptosis

  1. Kinetics of plasma membrane and mitochondrial alterations in cells undergoing apoptosis

    SciTech Connect

    Lizard, G.; Fournel, S.; Genestier, L.; Dhedin, N.

    1995-11-01

    Programmed cell death or apoptosis is characterized by typical morphological alterations. By transmission electron microscopy, apoptotic cells are identified by condensation of the chromatin in tight apposition to the nuclear envelope, alteration of the nuclear envelope and fragmentation of the nucleus, whereas integrity of the plasma membrane and organelles is preserved. Conversely cells undergoing necrosis display and early desintegration of cytoplasmic membrane and swelling of mitochondria. In this study we assessed by flow cytometry the sequential alterations of forward angle light scatter, 90{degrees} light scatter, and fluorescence associated with fluorescein diacetate, rhodamine 123, and propidium iodide in two human B cell lines undergoing apoptosis induced by the topoisomerase II inhibitor VP-16. The kinetics of these modifications were compared to those of cells undergoing necrosis induced by the topoisomerase II inhibitor VP-16. The kinetics of these modifications were compared to those of cells undergoing necrosis induced by sodium azide. At the same time intervals, cells were examined by transmission electron microscopy and by UV microscopy after staining with Hoechst 33342. We report that sequential changes in light scatters and fluorescein diacetate are similar in cells undergoing apoptosis or necrosis, whereas apoptosis is characterized by a slightly delayed decrease of mitochondrial activity as assessed by rhodamine 123 staining. Surprisingly, a part of cells undergoing apoptosis displayed an early uptake of propidium iodide followed by a condensation and then a fragmentation of their nuclei. It is concluded that uptake of propidium iodide is a very early marker of cell death which does not discriminate between necrosis and apoptosis. Along with biochemical criteria, nuclear morphology revealed by staining with Hoechst 33342 would seem to be of the most simple and most discriminative assay of apoptosis. 33 refs., 5 figs., 1 tab.

  2. Expression of the vault RNA protects cells from undergoing apoptosis

    PubMed Central

    Amort, Melanie; Nachbauer, Birgit; Tuzlak, Selma; Kieser, Arnd; Schepers, Aloys; Villunger, Andreas; Polacek, Norbert

    2015-01-01

    Non-protein-coding RNAs are a functionally versatile class of transcripts exerting their biological roles on the RNA level. Recently, we demonstrated that the vault complex-associated RNAs (vtRNAs) are significantly upregulated in Epstein–Barr virus (EBV)-infected human B cells. Very little is known about the function(s) of the vtRNAs or the vault complex. Here, we individually express latent EBV-encoded proteins in B cells and identify the latent membrane protein 1 (LMP1) as trigger for vtRNA upregulation. Ectopic expression of vtRNA1-1, but not of the other vtRNA paralogues, results in an improved viral establishment and reduced apoptosis, a function located in the central domain of vtRNA1-1. Knockdown of the major vault protein has no effect on these phenotypes revealing that vtRNA1-1 and not the vault complex contributes to general cell death resistance. This study describes a NF-κB-mediated role of the non-coding vtRNA1-1 in inhibiting both the extrinsic and intrinsic apoptotic pathways. PMID:25952297

  3. Heat-shock protein expression on the membrane of T cells undergoing apoptosis.

    PubMed Central

    Poccia, F; Piselli, P; Vendetti, S; Bach, S; Amendola, A; Placido, R; Colizzi, V

    1996-01-01

    Heat-shock proteins (hsp) represent a highly conserved family of proteins, normally localized in the cytoplasm and nucleus, whose expression is induced in situations involving cell stress. This paper reports the unusual translocation of hsp to the cell membrane of T cells undergoing apoptosis. We observed that glucocorticosteroid-induced thymocyte death is associated to the surface expression of hsp 60 and hsp 70 in a discrete fraction of apoptotic cells. hsp surface expression is closely related to a thymic subset of immature CD3low/- T cells. The expression of surface hsp 60 appears early after treatment with dexamethasone (3 hr) whereas the membrane expression of hsp 70 follows different kinetics and peaks later. Morphological analysis of the hsp+ apoptotic cells suggest that this subset represents late-stage apoptotic cells at their minimal volume before fragmentation into apoptotic bodies. Membrane expression of hsp is also associated with apoptosis in peripheral blood mononuclear cells from AIDS patients cultured in vitro. Altogether, we show that a discrete fraction of cells undergoing apoptosis expresses membrane hsp 60 and hsp 70, supporting the hypothesis that apoptosis causes a radical alteration in the expression of cell surface molecules. Surface hsp expressed during apoptosis may constitute a novel immune-context able to generate packages of self- and exogenous antigens, originating from degradation of altered cells. Images Figure 1 Figure 3 PMID:8707351

  4. Activation of AIFM2 enhances apoptosis of human lung cancer cells undergoing toxicological stress.

    PubMed

    Lu, Jun; Chen, Jian; Xu, Nianjun; Wu, Jun; Kang, Yani; Shen, Tingting; Kong, Hualei; Ma, Chao; Cheng, Ming; Shao, Zhifeng; Xu, Ling; Zhao, Xiaodong

    2016-09-01

    Application of cisplatin (DDP) for treating lung cancer is restricted due to its toxicity and lung cancer's drug resistance. In this study, we examined the effect of Jinfukang (JFK), an effective herbal medicine against lung cancer, on DDP-induced cytotoxicity in lung cancer cells. Morphologically, we observed that JFK increases DDP-induced pro-apoptosis in A549 cells in a synergistic manner. Transcriptome profiling analysis indicated that the combination of JFK and DDP regulates genes involved in apoptosis-related signaling pathways. Moreover, we found that the combination of JFK and DDP produces synergistic pro-apoptosis effect in other lung cancer cell lines, such as NCI-H1975, NCI-H1650, and NCI-H2228. Particularly, we demonstrated that AIFM2 is activated by the combined treatment of JFK and DDP and partially mediates the synergistic pro-apoptosis effect. Collectively, this study not only offered the first evidence that JFK promotes DDP-induced cytotoxicity, and activation of AIFM2 enhances apoptosis of human lung cancer cells undergoing toxicological stress, but also provided a novel insight for improving cytotoxicity by combining JFK with DDP to treat lung cancer cells. PMID:27392435

  5. Tissue transglutaminase-dependent posttranslational modification of the retinoblastoma gene product in promonocytic cells undergoing apoptosis.

    PubMed Central

    Oliverio, S; Amendola, A; Di Sano, F; Farrace, M G; Fesus, L; Nemes, Z; Piredda, L; Spinedi, A; Piacentini, M

    1997-01-01

    The retinoblastoma gene product (pRB) plays an important role in controlling both cell release from the G1 phase and apoptosis. We show here that in the early phases of apoptosis, pRB is posttranslationally modified by a tissue transglutaminase (tTG)-catalyzed reaction. In fact, by employing a novel haptenized lysis synthetic substrate which allows the isolation of glutaminyl-tTG substrates in vivo, we identified pRB as a potential tTG substrate in U937 cells undergoing apoptosis. In keeping with this finding, we showed that apoptosis of U937 cells is characterized by the rapid disappearance of the 105,000- to 110,000-molecular-weight pRB forms concomitantly with the appearance of a smear of immunoreactive products with a molecular weight of greater than 250,000. The shift in pRB molecular weight was reproduced by adding exogenous purified tTG to extracts obtained from viable U937 cells and was prevented by dansylcadaverine, a potent enzyme inhibitor. The effect of the pRB posttranslational modification during apoptosis was investigated by determining the E2F-1 levels and by isolating and characterizing pRB-null clones from U937 cells. Notably, the lack of pRB in these U937-derived clones renders these p53-null cells highly resistant to apoptosis induced by serum withdrawal, calphostin C, and ceramide. Taken together, these data suggest that tTG, acting on the pRB protein, might play an important role in the cell progression through the death program. PMID:9315663

  6. Elemene injection induced autophagy protects human hepatoma cancer cells from starvation and undergoing apoptosis.

    PubMed

    Lin, Yan; Wang, Keming; Hu, Chunping; Lin, Lin; Qin, Shukui; Cai, Xueting

    2014-01-01

    Elemene, a compound found in an herb used in traditional Chinese medicine, has shown promising anticancer effects against a broad spectrum of tumors. In an in vivo experiment, we found that apatinib, a tyrosine kinase inhibitor that selectively inhibits VEGFR2, combined with elemene injection (Ele) for the treatment of H22 solid tumor in mice resulted in worse effectiveness than apatinib alone. Moreover, Ele could protect HepG2 cells from death induced by serum-free starvation. Further data on the mechanism study revealed that Ele induced protective autophagy and prevented human hepatoma cancer cells from undergoing apoptosis. Proapoptosis effect of Ele was enhanced when proautophagy effect was inhibited by hydroxychloroquine. Above all, Ele has the effect of protecting cancer cells from death either in apatinib induced nutrient deficient environment or in serum-free induced starvation. A combination of elemene injection with autophagy inhibitor might thus be a useful therapeutic option for hepatocellular carcinoma. PMID:25152762

  7. Fine mapping of 28S rRNA sites specifically cleaved in cells undergoing apoptosis.

    PubMed Central

    Houge, G; Robaye, B; Eikhom, T S; Golstein, J; Mellgren, G; Gjertsen, B T; Lanotte, M; Døskeland, S O

    1995-01-01

    Bona fide apoptosis in rat and human leukemia cells, rat thymocytes, and bovine endothelial cells was accompanied by limited and specific cleavage of polysome-associated and monosome-associated 28S rRNA, with 18S rRNA being spared. Specific 28S rRNA cleavage was observed in all instances of apoptotic death accompanied by internucleosomal DNA fragmentation, with cleavage of 28S rRNA and of DNA being linked temporally. This indicates that 28S rRNA fragmentation may be as general a feature of apoptosis as internucleosomal DNA fragmentation and that concerted specific cleavage of intra- and extranuclear polynucleotides occurs in apoptosis. Apoptosis-associated cleavage sites were mapped to the 28S rRNA divergent domains D2, D6 (endothelial cells), and D8. The D2 cuts occurred in hairpin loop junctions considered to be buried in the intact ribosome, suggesting that this rRNA region becomes a target for RNase attack in apoptotic cells. D8 was cleaved in two exposed UU(U) sequences in bulge loops. Treatment with agents causing necrotic cell death or aging of cell lysates failed to produce any detectable limited D2 cleavage but did produce a more generalized cleavage in the D8 region. Of potential functional interest was the finding that the primary cuts in D2 exactly flanked a 0.3-kb hypervariable subdomain (D2c), allowing excision of the latter. The implication of hypervariable rRNA domains in apoptosis represents the first association of any functional process with these enigmatic parts of the ribosomes. PMID:7891700

  8. Insulin-like growth factor-I (IGF-I) protects cultured equine Leydig cells from undergoing apoptosis.

    PubMed

    Yoon, M J; Roser, J F

    2010-12-01

    Leydig cells located in the interstitial space of the testicular parenchyma produce testosterone which plays a critical role in the maintenance and restoration of spermatogenesis in many species, including horses. For normal spermatogenesis, maintaining Leydig cells is critical to provide an optimal and constant level of testosterone. Recently, an anti-apoptotic effect of IGF-I in testicular cells in rats has been reported, but a similar effect of IGF-I on equine Leydig cells remains to be elucidated. If IGF-I also protects stallion testicular cells from undergoing apoptosis, then IGF-I may have potential as a treatment regime to prevent testicular degeneration. The present study was designed to evaluate the anti-apoptotic effect of IGF-I on cultured equine Leydig cells. Testes were collected from 5 post-pubertal stallions (2-4 years old) during routine castrations. A highly purified preparation of equine Leydig cells was obtained from a discontinuous Percoll gradient. Purity of equine Leydig cells was assessed using histochemical 3β-HSD staining. Equine Leydig cells and selected doses of recombinant human IGF-1 (rhIGF-I; Parlow A.F., National Hormone and Peptide Program, Harbor-UCLA Medical Center) were added to wells of 24 or 96 well culture plates in triplicate and cultured for 24 or 48 h under 95% air:5% CO(2) at 34°C. After 24 or 48 h incubation, apoptotic rate was assessed using a Cell Death Detection ELISA kit. Significantly lower apoptotic rates were observed in equine Leydig cells cultured with 5, 10, or 50ng/ml of rhIGF-I compared with control cells cultured without rhIGF-I for 24h. Exposure to 1, 5, 10 or 50 ng/ml of rhIGF-I significantly decreased apoptotic rate in equine Leydig cells cultured for 48 h. After 48 h incubation, cells were labeled with Annexin V and propodium iodine to determine the populations of healthy, apoptotic, and necrotic cells by counting stained cells using a Nikon Eclipse inverted fluorescence microscope. As a percentage of

  9. Bcl2-low-expressing MCF7 cells undergo necrosis rather than apoptosis upon staurosporine treatment.

    PubMed Central

    Poliseno, Laura; Bianchi, Laura; Citti, Lorenzo; Liberatori, Sabrina; Mariani, Laura; Salvetti, Alessandra; Evangelista, Monica; Bini, Luca; Pallini, Vitaliano; Rainaldi, Giuseppe

    2004-01-01

    We present a ribozyme-based strategy for studying the effects of Bcl2 down-regulation. The anti-bcl2 hammerhead ribozyme Rz-bcl2 was stably transfected into MCF7 cancer cells and the cleavage of Bcl2 mRNA was demonstrated using a new assay for cleavage product detection, while Western blot analysis showed a concomitant depletion of Bcl2 protein. Rz-bcl2-expressing cells were more sensitive to staurosporine than control cells. Moreover, both molecular and cellular read-outs indicated that staurosporine-induced cell death was necrosis rather than apoptosis in these cells. The study of the effects of Bcl2 down-regulation was extended to the global MCF7 protein expression profile, exploiting a proteomic approach. Two reference electro-pherograms of Rz-bcl2-transfected cells, one with the ribozyme in a catalytically active form and the other with the ribozyme in a catalytically inactive form, were obtained. When comparing the two-dimensional maps, 53 differentially expressed spots were found, four of which were identified by MALDI-TOF (matrix-assisted laser-desorption ionization-time-of-flight) MS as calreticulin, nucleophosmin, phosphoglycerate kinase and pyruvate kinase. How the up-regulation of these proteins might help to explain the modification of Bcl2 activity is discussed. PMID:14748742

  10. Dendritic Cells Regulate GPR34 through Mitogenic Signals and Undergo Apoptosis in Its Absence.

    PubMed

    Jäger, Elisabeth; Schulz, Angela; Lede, Vera; Lin, Chen-Ching; Schöneberg, Torsten; Le Duc, Diana

    2016-03-15

    Dendritic cells (DCs) are specifically equipped with the G protein-coupled receptor 34 (GPR34). Tight regulation of GPR34 gene expression seems highly important for proper immunological functions, because the absence of this receptor leads to an alteration of the immune response, whereas overexpression was reported to be involved in neuroinflammation. However, the regulatory mechanism of GPR34 expression has not yet been investigated. Whole-transcriptome RNA sequencing analysis from spleens and DCs of GPR34 knockout and wild-type mice, combined with protein-protein interaction data, revealed functional modules affected by the absence of this receptor. Among these, NF-κB, MAPK, and apoptosis-signaling pathways showed high significance. Using murine DCs we experimentally show that NF-κB and MAPK pathways are involved in the downregulation of GPR34. DCs lacking GPR34 have a higher caspase-3/7 activity and increased apoptosis levels. Our study reveals a novel role of GPR34 in the fate of DCs and identifies a regulatory mechanism that could be relevant for treatment of GPR34-overexpressing pathologies, such as neuroinflammatory or cancer conditions. PMID:26851221

  11. Inducible peroxidases mediate nitration of anopheles midgut cells undergoing apoptosis in response to Plasmodium invasion.

    PubMed

    Kumar, Sanjeev; Gupta, Lalita; Han, Yeon Soo; Barillas-Mury, Carolina

    2004-12-17

    Plasmodium berghei invasion of Anopheles stephensi midgut cells causes severe damage, induces expression of nitric-oxide synthase, and leads to apoptosis. The present study indicates that invasion results in tyrosine nitration, catalyzed as a two-step reaction in which nitric-oxide synthase induction is followed by increased peroxidase activity. Ookinete invasion induced localized expression of peroxidase enzymes, which catalyzed protein nitration in vitro in the presence of nitrite and H(2)O(2). Histochemical stainings revealed that when a parasite migrates laterally and invades more than one cell, the pattern of induced peroxidase activity is similar to that observed for tyrosine nitration. In Anopheles gambiae, ookinete invasion elicited similar responses; it induced expression of 5 of the 16 peroxidase genes predicted by the genome sequence and decreased mRNA levels of one of them. One of these inducible peroxidases has a C-terminal oxidase domain homologous to the catalytic moiety of phagocyte NADPH oxidase and could provide high local levels of superoxide anion (O(2)), that when dismutated would generate the local increase in H(2)O(2) required for nitration. Chemically induced apoptosis of midgut cells also activated expression of four ookinete-induced peroxidase genes, suggesting their involvement in general apoptotic responses. The two-step nitration reaction provides a mechanism to precisely localize and circumscribe the toxic products generated by defense reactions involving nitration. The present study furthers our understanding of the biochemistry of midgut defense reactions to parasite invasion and how these may influence the efficiency of malaria transmission by anopheline mosquitoes. PMID:15456781

  12. Real-time investigation of cytochrome c release profiles in living neuronal cells undergoing amyloid beta oligomer-induced apoptosis

    NASA Astrophysics Data System (ADS)

    Lee, Jae Young; Park, Younggeun; Pun, San; Lee, Sung Sik; Lo, Joe F.; Lee, Luke P.

    2015-06-01

    Intracellular Cyt c release profiles in living human neuroblastoma undergoing amyloid β oligomer (AβO)-induced apoptosis, as a model Alzheimer's disease-associated pathogenic molecule, were analysed in a real-time manner using plasmon resonance energy transfer (PRET)-based spectroscopy.Intracellular Cyt c release profiles in living human neuroblastoma undergoing amyloid β oligomer (AβO)-induced apoptosis, as a model Alzheimer's disease-associated pathogenic molecule, were analysed in a real-time manner using plasmon resonance energy transfer (PRET)-based spectroscopy. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr02390d

  13. The content of DNA and RNA in microparticles released by Jurkat and HL-60 cells undergoing in vitro apoptosis

    SciTech Connect

    Reich, Charles F.; Pisetsky, David S.

    2009-03-10

    Microparticles are small membrane-bound vesicles that are released from apoptotic cells during blebbing. These particles contain DNA and RNA and display important functional activities, including immune system activation. Furthermore, nucleic acids inside the particle can be analyzed as biomarkers in a variety of disease states. To elucidate the nature of microparticle nucleic acids, DNA and RNA released in microparticles from the Jurkat T and HL-60 promyelocytic cell lines undergoing apoptosis in vitro were studied. Microparticles were isolated from culture media by differential centrifugation and characterized by flow cytometry and molecular approaches. In these particles, DNA showed laddering by gel electrophoresis and was present in a form that allowed direct binding by a monoclonal anti-DNA antibody, suggesting antigen accessibility even without fixation. Analysis of RNA by gel electrophoresis showed intact 18s and 28s ribosomal RNA bands, although lower molecular bands consistent with 28s ribosomal RNA degradation products were also present. Particles also contained messenger RNA as shown by RT-PCR amplification of sequences for {beta}-actin and GAPDH. In addition, gel electrophoresis showed the presence of low molecular weight RNA in the size range of microRNA. Together, these results indicate that microparticles from apoptotic Jurkat and HL-60 cells contain diverse nucleic acid species, indicating translocation of both nuclear and cytoplasmic DNA and RNA as particle release occurs during death.

  14. Balance of unidirectional monovalent ion fluxes in cells undergoing apoptosis: why does Na+/K+ pump suppression not cause cell swelling?

    PubMed

    Yurinskaya, Valentina E; Rubashkin, Andrey A; Vereninov, Alexey A

    2011-05-01

    Cells dying according to the apoptotic program, unlike cells dying via an unprogrammed mode, are able to avoid swelling and osmotic bursting with membrane disruption.There are indications that apoptosis is accompanied by suppression of the Na+/K+ pump and changes in the K+ and Cl− channels. It remains unclear how ion fluxes through individual ion pathways are integrated so as to induce loss of intracellular ions and concomitant apoptotic volume decrease. A decrease in activity of the sodium pump during apoptosis should cause cell swelling rather than shrinkage. We have made the first systemic analysis of the monovalent ion flux balance in apoptotic cells. Experimental data were obtained for human U937 cells treated with staurosporine for 4–5 h, which is known to induce apoptosis. The data include cellular Cl− content and fluxes, K+, Na+, water content and ouabain-sensitive and -resistant Rb+ fluxes.Unidirectional monovalent ion fluxeswere calculated using these data and a cell model comprising the double Donnan system with the Na+/K+ pump, Cl−, K+, Na+ channels, the Na+–K+–2Cl−cotransporter (NKCC), the Na+–Cl− cotransporter (NC), and the equivalent Cl−/Cl− exchange.Apoptotic cell shrinkage was found to be caused, depending on conditions, either by an increase in the integral channel permeability of membrane for K+ or by suppression of the pump coupledwith a decrease in the integral channel permeability of membrane for Na+. The decrease in the channel permeability of membrane for Na+ plays a crucial role in cell dehydration in apoptosis accompanied by suppression of the pump. Supplemental Table S1 is given for easy calculating flux balance under specified conditions. PMID:21486767

  15. Labdane type diterpenes down-regulate the expression of c-Myc protein, but not of Bcl-2, in human leukemia T-cells undergoing apoptosis.

    PubMed

    Dimas, K; Demetzos, C; Vaos, V; Ioannidis, P; Trangas, T

    2001-06-01

    Sclareol (1) and ent-3beta-hydroxy-13-epi-manoyl oxide (2) belong to the labdane type diterpenes. They were isolated from the leaves and from the fruits of Cistus creticus subsp. creticus, and were found to be active against human leukemic cell lines. Compound 2 was converted to its thiomidazolide derivative (3). Compounds 1 and 3 were found to induce apoptotic cell death in human T-cell leukemia lines and to interfere with their cell cycle, arresting cells at G(0/1) phase. Apoptosis can involve the activation and/or suppression of critical genes such as c-myc whose reduction or its inappropriate expression can be associated with induction of cell death and bcl-2 whose activation prevents apoptosis in the latter case. In order to detect any concomitant effect (1 and 3) upon c-myc and bcl-2 oncogene expression, we performed Western blot analysis to determine the levels of expression of these two genes upon treatment with the above compounds. Western blot analysis showed that of c-myc proto-oncogene levels were markedly reduced before massive apoptosis ensued in H33AJ-JA1 and MOLT3 cells, while bcl-2 expression remained unaffected. Thus, induction of apoptosis due to compounds 1 and 3 in these T-cell leukemic cell lines is preceded by c-myc down regulation and furthermore sustained bcl-2 expression does not rescue cells from apoptosis under the conditions used. PMID:11337016

  16. Impaired Hepatitis C Virus (HCV)-Specific Effector CD8+ T Cells Undergo Massive Apoptosis in the Peripheral Blood during Acute HCV Infection and in the Liver during the Chronic Phase of Infection▿

    PubMed Central

    Radziewicz, Henry; Ibegbu, Chris C.; Hon, Huiming; Osborn, Melissa K.; Obideen, Kamil; Wehbi, Mohammad; Freeman, Gordon J.; Lennox, Jeffrey L.; Workowski, Kimberly A.; Hanson, Holly L.; Grakoui, Arash

    2008-01-01

    A majority of patients infected with hepatitis C virus (HCV) do not sustain an effective T-cell response, and viremia persists. The mechanism leading to failure of the HCV-specific CD8+ T-cell response in patients developing chronic infection is unclear. We investigated apoptosis susceptibility of HCV-specific CD8+ T cells during the acute and chronic stages of infection. Although HCV-specific CD8+ T cells in the blood during the acute phase of infection and in the liver during the chronic phase were highly activated and expressed an effector phenotype, the majority was undergoing apoptosis. In contrast, peripheral blood HCV-specific CD8+ T cells during the chronic phase expressed a resting memory phenotype. Apoptosis susceptibility of HCV-specific CD8+ T cells was associated with very high levels of programmed death-1 (PD-1) and low CD127 expression and with significant functional T-cell deficits. Further evaluation of the “death phase” of HCV-specific CD8+ T cells during acute HCV infection showed that the majority of cells were dying by a process of cytokine withdrawal, mediated by activated caspase 9. Contraction during the acute phase occurred rapidly via this process despite the persistence of the virus. Remarkably, in the chronic phase of HCV infection, at the site of infection in the liver, a substantial frequency of caspase 9-mediated T-cell death was also present. This study highlights the importance of cytokine deprivation-mediated apoptosis with consequent down-modulation of the immune response to HCV during acute and chronic infections. PMID:18667503

  17. ATM-deficient human fibroblast cells are resistant to low levels of DNA double-strand break induced apoptosis and subsequently undergo drug-induced premature senescence

    SciTech Connect

    Park, Jun; Jo, Yong Hwa; Cho, Chang Hoon; Choe, Wonchae; Kang, Insug; Baik, Hyung Hwan; Yoon, Kyung-Sik

    2013-01-04

    Highlights: Black-Right-Pointing-Pointer A-T cells were not hypersensitive to low levels of DNA DSBs. Black-Right-Pointing-Pointer A-T cells have enhanced Akt but defect in activation of p53 and apoptotic proteins. Black-Right-Pointing-Pointer A-T cells underwent premature senescence after DNA damage accumulated. Black-Right-Pointing-Pointer Chemotherapeutic effect in cancer therapy may be associated with premature senescence. -- Abstract: DNA DSBs are induced by IR or radiomimetic drugs such as doxorubicin. It has been indicated that cells from ataxia-telangiectasia patients are highly sensitive to radiation due to defects in DNA repair, but whether they have impairment in apoptosis has not been fully elucidated. A-T cells showed increased sensitivity to high levels of DNA damage, however, they were more resistant to low doses. Normal cells treated with combination of KU55933, a specific ATM kinase inhibitor, and doxorubicin showed increased resistance as they do in a similar manner to A-T cells. A-T cells have higher viability but more DNA breaks, in addition, the activations of p53 and apoptotic proteins (Bax and caspase-3) were deficient, but Akt expression was enhanced. A-T cells subsequently underwent premature senescence after treatment with a low dose of doxorubicin, which was confirmed by G2 accumulation, senescent morphology, and SA-{beta}-gal positive until 15 days repair incubation. Finally, A-T cells are radio-resistant at low doses due to its defectiveness in detecting DNA damage and apoptosis, but the accumulation of DNA damage leads cells to premature senescence.

  18. Actinobacillus actinomycetemcomitans induces apoptosis in human monocytic THP-1 cells.

    PubMed

    Kato, Satsuki; Sugimura, Norihiko; Nakashima, Keisuke; Nishihara, Tatsuji; Kowashi, Yusuke

    2005-03-01

    It has previously been reported that the murine macrophage cell line J774.1 and the human oral epithelial cell line KB undergo apoptosis as a result of Actinobacillus actinomycetemcomitans infection. Recent studies have demonstrated that apoptosis regulation is modulated by multiple phosphorylation of several different protein kinases, including the major subtypes of the mitogen-activated protein kinase (MAPK) family. The MAPK family promotes cell survival and/or proliferation in response to growth factor stimulation, or apoptosis in response to various stress stimuli. The primary objective of the present investigation was to clarify whether human immune cells undergo apoptosis following A. actinomycetemcomitans infection and, if so, to establish the involvement of the MAPK family. Human monocytic THP-1 cells were infected with A. actinomycetemcomitans in microtubes. Lactate dehydrogenase release into the culture supernatant and DNA fragmentation in the cells were monitored. DNA fragmentation was also identified by agarose gel electrophoresis. Cell death following A. actinomycetemcomitans infection occurred by apoptosis, shown by an increase in the proportion of fragmented DNA and the typical ladder pattern of DNA fragmentation indicative of apoptosis. Furthermore, p38 MAPK activity and tumour necrosis factor alpha (TNF-alpha) levels increased following A. actinomycetemcomitans infection. In contrast, cell death and TNF-alpha levels in infected cells decreased upon addition of a p38 inhibitor or an anti-TNF-alpha antibody. However, exogenous TNF-alpha could not induce apoptosis in uninfected THP-1 cells. Interestingly, p38 MAPK activity diminished in the presence of anti-TNF-alpha antibody. These findings indicated that A. actinomycetemcomitans infection induces apoptosis in THP-1 cells and that p38 MAPK activity is directly involved in apoptosis. TNF-alpha may play an indirect role in apoptosis via enhanced p38 MAPK activity. A. actinomycetemcomitans

  19. Mitochondria in human pluripotent stem cell apoptosis.

    PubMed

    TeSlaa, Tara; Setoguchi, Kiyoko; Teitell, Michael A

    2016-04-01

    Human pluripotent stem cells (hPSCs) have great potential in regenerative medicine because they can differentiate into any cell type in the body. Genome integrity is vital for human development and for high fidelity passage of genetic information across generations through the germ line. To ensure genome stability, hPSCs maintain a lower rate of mutation than somatic cells and undergo rapid apoptosis in response to DNA damage and additional cell stresses. Furthermore, cellular metabolism and the cell cycle are also differentially regulated between cells in pluripotent and differentiated states and can aid in protecting hPSCs against DNA damage and damaged cell propagation. Despite these safeguards, clinical use of hPSC derivatives could be compromised by tumorigenic potential and possible malignant transformation from failed to differentiate cells. Since hPSCs and mature cells differentially respond to cell stress, it may be possible to specifically target undifferentiated cells for rapid apoptosis in mixed cell populations to enable safer use of hPSC-differentiated cells in patients. PMID:26828436

  20. C-terminal Binding Proteins are Essential Pro-survival Factors that Undergo Caspase-dependent Downregulation during Neuronal Apoptosis

    PubMed Central

    Kelsey, Natalie A.; Bouchard, Ron J.; Linseman, Daniel A.

    2013-01-01

    C-terminal binding proteins (CtBPs) are transcriptional co-repressors that are subject to proteasome-dependent downregulation during apoptosis. Alternative mechanisms that regulate CtBP expression are currently under investigation and the role of CtBPs in neuronal survival is largely unexplored. Here, we show that CtBPs are downregulated in cerebellar granule neurons (CGNs) induced to undergo apoptosis by a variety of stressors. Moreover, antisense-mediated downregulation of CtBP1 is sufficient to cause CGN apoptosis. Similarly, the CtBP inhibitor, 4-methylthio-2-oxobutyric acid, induces expression of the CtBP target Noxa and causes actinomycin-sensitive CGN apoptosis. Unexpectedly, we found that the mechanism of CtBP downregulation in CGNs undergoing apoptosis varies in a stimulus-specific manner involving either the proteasome or caspases. In the case of CGNs deprived of depolarizing potassium (5K apoptotic condition), caspases appear to play a dominant role in CtBP downregulation. However, incubation in 5K does not enhance the kinetics of CtBP1 degradation and recombinant CtBP1 is not cleaved in vitro by caspase-3. In addition, 5K has no significant effect on CtBP transcript expression. Finally, mouse embryonic stem cells display caspase-dependent downregulation of CtBP1 following exposure to staurosporine, an effect that is not observed in DGCR8 knockout cells which are deficient in miRNA processing. These data identify caspase-dependent downregulation of CtBPs as an alternative mechanism to the proteasome for regulation of these transcriptional co-repressors in neurons undergoing apoptosis. Moreover, caspases appear to regulate CtBP expression indirectly, at a post-transcriptional level, and via a mechanism that is dependent upon miRNA processing. We conclude that CtBPs are essential pro-survival proteins in neurons and their downregulation contributes significantly to neuronal apoptosis via the de-repression of pro-apoptotic genes. PMID:23859824

  1. C-terminal binding proteins are essential pro-survival factors that undergo caspase-dependent downregulation during neuronal apoptosis.

    PubMed

    Stankiewicz, Trisha R; Schroeder, Emily K; Kelsey, Natalie A; Bouchard, Ron J; Linseman, Daniel A

    2013-09-01

    C-terminal binding proteins (CtBPs) are transcriptional co-repressors that are subject to proteasome-dependent downregulation during apoptosis. Alternative mechanisms that regulate CtBP expression are currently under investigation and the role of CtBPs in neuronal survival is largely unexplored. Here, we show that CtBPs are downregulated in cerebellar granule neurons (CGNs) induced to undergo apoptosis by a variety of stressors. Moreover, antisense-mediated downregulation of CtBP1 is sufficient to cause CGN apoptosis. Similarly, the CtBP inhibitor, 4-methylthio-2-oxobutyric acid, induces expression of the CtBP target Noxa and causes actinomycin-sensitive CGN apoptosis. Unexpectedly, we found that the mechanism of CtBP downregulation in CGNs undergoing apoptosis varies in a stimulus-specific manner involving either the proteasome or caspases. In the case of CGNs deprived of depolarizing potassium (5K apoptotic condition), caspases appear to play a dominant role in CtBP downregulation. However, incubation in 5K does not enhance the kinetics of CtBP1 degradation and recombinant CtBP1 is not cleaved in vitro by caspase-3. In addition, 5K has no significant effect on CtBP transcript expression. Finally, mouse embryonic stem cells display caspase-dependent downregulation of CtBP1 following exposure to staurosporine, an effect that is not observed in DGCR8 knockout cells which are deficient in miRNA processing. These data identify caspase-dependent downregulation of CtBPs as an alternative mechanism to the proteasome for regulation of these transcriptional co-repressors in neurons undergoing apoptosis. Moreover, caspases appear to regulate CtBP expression indirectly, at a post-transcriptional level, and via a mechanism that is dependent upon miRNA processing. We conclude that CtBPs are essential pro-survival proteins in neurons and their downregulation contributes significantly to neuronal apoptosis via the de-repression of pro-apoptotic genes. PMID:23859824

  2. Analysis of Residual DSBs in Ataxia-Telangiectasia Lymphoblast Cells Initiating Apoptosis

    PubMed Central

    Anglada, Teresa; Terradas, Mariona; Hernández, Laia; Genescà, Anna; Martín, Marta

    2016-01-01

    In order to examine the relationship between accumulation of residual DNA double-strand breaks (DSBs) and cell death, we have used a control and an ATM (Ataxia-Telangiectasia Mutated) defective cell line, as Ataxia-Telangiectasia (AT) cells tend to accumulate residual DSBs at long times after damage infliction. After irradiation, AT cells showed checkpoint impairment and a fraction of cells displayed an abnormal centrosome number and tetraploid DNA content, and this fraction increased along with apoptosis rates. At all times analyzed, AT cells displayed a significantly higher rate of radiation-induced apoptosis than normal cells. Besides apoptosis, 70–85% of the AT viable cells (TUNEL-negative) carried ≥10 γH2AX foci/cell, while only 12–27% of normal cells did. The fraction of AT and normal cells undergoing early and late apoptosis were isolated by flow cytometry and residual DSBs were concretely scored in these populations. Half of the γH2AX-positive AT cells undergoing early apoptosis carried ≥10 γH2AX foci/cell and this fraction increased to 75% in late apoptosis. The results suggest that retention of DNA damage-induced γH2AX foci is an indicative of lethal DNA damage, as cells undergoing apoptosis are those accumulating more DSBs. Scoring of residual γH2AX foci might function as a predictive tool to assess radiation-induced apoptosis. PMID:27057549

  3. Thrombospondin cooperates with CD36 and the vitronectin receptor in macrophage recognition of neutrophils undergoing apoptosis.

    PubMed Central

    Savill, J; Hogg, N; Ren, Y; Haslett, C

    1992-01-01

    We have investigated the cell surface recognition mechanisms used by human monocyte-derived macrophages (M phi) in phagocytosis of intact aging human neutrophils (PMNs) undergoing apoptosis. This study shows that the adhesive protein thrombospondin (TSP) was present in the interaction, both associated with the M phi surface and in solution at a mean concentration of 0.59 micrograms/ml. The interaction was inhibited by treatment of M phi (but not aged PMN) with cycloheximide, but could be "rescued" by replenishment with exogenous TSP. Under control conditions, M phi recognition of aged PMNs was specifically potentiated by purified platelet TSP at 5 micrograms/ml, present either in the interaction or if preincubated with either cell type, suggesting that TSP might act as a "molecular bridge" between the two cell types. In support, both aged PMN and M phi were found to adhere to TSP, and phagocytosis of aged PMN was specifically inhibited by (a) excess soluble TSP; (b) antibodies to TSP that also inhibit TSP-mediated adhesion to aged PMN; and (c) down-regulation of M phi receptors for TSP by plating M phi on TSP-coated surfaces. Furthermore, inhibition with mAbs/Arg-Gly-Asp-Ser peptide of the candidate M phi receptors for TSP, CD36, and alpha v beta 3 exerted synergistic effects on both M phi recognition of aged PMN and M phi adhesion to TSP, indicating that "two point" adhesion of TSP to these M phi structures is involved in phagocytosis of aged PMN. Our findings indicate newly defined roles for TSP and CD36 in phagocytic clearance of senescent neutrophils, which may limit inflammatory tissue injury and promote resolution. Images PMID:1383273

  4. Optogenetic apoptosis: light-triggered cell death.

    PubMed

    Hughes, Robert M; Freeman, David J; Lamb, Kelsey N; Pollet, Rebecca M; Smith, Weston J; Lawrence, David S

    2015-10-01

    An optogenetic Bax has been designed that facilitates light-induced apoptosis. We demonstrate that mitochondrial recruitment of a genetically encoded light-responsive Bax results in the release of mitochondrial proteins, downstream caspase-3 cleavage, changes in cellular morphology, and ultimately cell death. Mutagenesis of a key phosphorylatable residue or modification of the C-terminus mitigates background (dark) levels of apoptosis that result from Bax overexpression. The mechanism of optogenetic Bax-mediated apoptosis was explored using a series of small molecules known to interfere with various steps in programmed cell death. Optogenetic Bax appears to form a mitochondrial apoptosis-induced channel analogous to that of endogenous Bax. PMID:26418181

  5. Cilostazol suppresses angiotensin II-induced apoptosis in endothelial cells

    PubMed Central

    SHI, MIAO-QIAN; SU, FEI-FEI; XU, XUAN; LIU, XIONG-TAO; WANG, HONG-TAO; ZHANG, WEI; LI, XUE; LIAN, CHENG; ZHENG, QIANG-SUN; FENG, ZHI-CHUN

    2016-01-01

    Patients with essential hypertension undergo endothelial dysfunction, particularly in the conduit arteries. Cilostazol, a type III phosphodiesterase inhibitor, serves a role in the inhibition of platelet aggregation and it is widely used in the treatment of peripheral vascular diseases. Previous studies have suggested that cilostazol suppresses endothelial dysfunction; however, it remains unknown whether cilostazol protects the endothelial function in essential hypertension. The aim of the present study was to investigate whether, and how, cilostazol suppresses angiotensin II (angII)-induced endothelial dysfunction. Human umbilical vein endothelial cells (HUVECs) and Sprague Dawley rats were exposed to angII and treated with cilostazol. Endothelial cell apoptosis and function, nitric oxide and superoxide production, phosphorylation (p) of Akt, and caspase-3 protein expression levels were investigated. AngII exposure resulted in the apoptosis of endothelial cells in vitro and in vivo. In vitro, cilostazol significantly suppressed the angII-induced apoptosis of HUVECs; however, this effect was reduced in the presence of LY294002, a phosphoinositide 3 kinase (PI3K) inhibitor. Furthermore, cilostazol suppressed the angII-induced p-Akt downregulation and cleaved caspase-3 upregulation. These effects were also alleviated by LY294002. In vivo, cilostazol suppressed the angII-induced endothelial cell apoptosis and dysfunction. Cilostazol was also demonstrated to partially reduced the angII-induced increase in superoxide production. The results of the present study suggested that cilostazol suppresses endothelial apoptosis and dysfunction by modulating the PI3K/Akt pathway. PMID:26862035

  6. Umbelliprenin Induces Apoptosis in CLL Cell Lines

    PubMed Central

    Ziai, Seyed Ali; Gholami, Omid; Iranshahi, Mehrdad; Zamani, Amir Hassan; Jeddi-Tehrani, Mahmood

    2012-01-01

    Chronic lymphocytic leukemia (CLL) remains an incurable disease that requires innovative new approaches to improve therapeutic outcome. Many Ferula species, including F. asa-foetida, synthesize terpenyloxy coumarins. One of these coumarins is umbelliprenin, which has been implicated with induction of apoptosis in some cancer cell lines. In this study induction of apoptosis by umbelliprenin on Jurkat T-CLL and Raji B-CLL cell lines was studied. In this regard, cells were incubated with various concentrations of umbelliprenin in-vitro for different times and assayed for apoptosis with annexin V–FITC/PI double staining flowcytometry method. Results showed that umbelliprenin induced apoptosis in leukemic cells in a dose- and time-dependent manner and that CLL cells were more susceptible to umbelliprenin induced cell death than normal peripheral blood mononuclear cell (PBMCs). Moreover, we study the induction of apoptosis in Jurkat cells by umbelliprenin in the presence of interleukin 4 (IL-4) as an agent that causes resistance to apoptosis in CLL cells, was also student. We showed that IL-4 can not reduce apoptotic effect of umbelliprenin. The preferential toxicity of umbelliprenin for CLL cells, supports the hypothesis that oral administration of umbelliprenin in the form of foods or folk medicines containing this coumarin, might enhance protection against the development of CLL in man with little side effects. In conclusion, umbelliprenin may be an effective therapeutic agent in the treatment of CLL, and thus clinical studies with umbelliprenin may be appropriate. PMID:24250490

  7. Senescence and apoptosis: dueling or complementary cell fates?

    PubMed Central

    Childs, Bennett G; Baker, Darren J; Kirkland, James L; Campisi, Judith; van Deursen, Jan M

    2014-01-01

    In response to a variety of stresses, mammalian cells undergo a persistent proliferative arrest known as cellular senescence. Many senescence-inducing stressors are potentially oncogenic, strengthening the notion that senescence evolved alongside apoptosis to suppress tumorigenesis. In contrast to apoptosis, senescent cells are stably viable and have the potential to influence neighboring cells through secreted soluble factors, which are collectively known as the senescence-associated secretory phenotype (SASP). However, the SASP has been associated with structural and functional tissue and organ deterioration and may even have tumor-promoting effects, raising the interesting evolutionary question of why apoptosis failed to outcompete senescence as a superior cell fate option. Here, we discuss the advantages that the senescence program may have over apoptosis as a tumor protective mechanism, as well as non-neoplastic functions that may have contributed to its evolution. We also review emerging evidence for the idea that senescent cells are present transiently early in life and are largely beneficial for development, regeneration and homeostasis, and only in advanced age do senescent cells accumulate to an organism’s detriment. PMID:25312810

  8. Caspases indirectly regulate cleavage of the mitochondrial fusion GTPase OPA1 in neurons undergoing apoptosis

    PubMed Central

    Loucks, F. Alexandra; Schroeder, Emily K.; Zommer, Amelia E.; Hilger, Shea; Kelsey, Natalie A.; Bouchard, Ron J.; Blackstone, Craig; Brewster, Jay L.; Linseman, Daniel A.

    2009-01-01

    The critical processes of mitochondrial fission and fusion are regulated by members of the dynamin family of GTPases. Imbalances in mitochondrial fission and fusion contribute to neuronal cell death. For example, increased fission mediated by the dynamin-related GTPase, Drp1, or decreased fusion resulting from inactivating mutations in the OPA1 GTPase, cause neuronal apoptosis and/or neurodegeneration. Recent studies indicate that post-translational processing regulates OPA1 function in non-neuronal cells and moreover, aberrant processing of OPA1 is induced during apoptosis. To date, the post-translational processing of OPA1 during neuronal apoptosis has not been examined. Here, we show that cerebellar granule neurons (CGNs) or neuroblastoma cells exposed to pro-apoptotic stressors display a novel N-terminal cleavage of OPA1 which is blocked by either pan-caspase or caspase-8 selective inhibitors. OPA1 cleavage occurs concurrently with mitochondrial fragmentation and cytochrome c release in CGNs deprived of depolarizing potassium (5K condition). Although a caspase-8 selective inhibitor prevents both 5K-induced OPA1 cleavage and mitochondrial fragmentation, recombinant caspase-8 fails to cleave OPA1 in vitro. In marked contrast, either caspase-8 or caspase-3 stimulates OPA1 cleavage in digitonin-permeabilized rat brain mitochondria, suggesting that OPA1 is cleaved by an intermembrane space protease which is regulated by active caspases. Finally, the N-terminal truncation of OPA1 induced during neuronal apoptosis removes an essential residue (K301) within the GTPase domain. These data are the first to demonstrate OPA1 cleavage during neuronal apoptosis and they implicate caspases as indirect regulators of OPA1 processing in degenerating neurons. PMID:19046944

  9. Induction of T-cell apoptosis by human herpesvirus 6.

    PubMed Central

    Inoue, Y; Yasukawa, M; Fujita, S

    1997-01-01

    The mechanisms of cell death in CD4+ T cells mediated by human herpesvirus 6 (HHV-6) were investigated. The frequency of cell death in the human CD4+ T-cell line JJHAN, which had been inoculated with HHV-6 variant A or B, appeared to be augmented by tumor necrosis factor alpha (TNF-alpha). Agarose gel electrophoresis of DNA from HHV-6-inoculated cells showed DNA fragmentation in multiples of the oligonucleosome length unit. The degree of DNA fragmentation increased when HHV-6-inoculated cells were cultured in the presence of TNF-alpha. Flow cytometry and Scatchard analysis of TNF receptors revealed an increase in the number of the p55 form of TNF receptors on JJHAN cells after HHV-6 inoculation. It also appeared that treatment with anti-Fas monoclonal antibody (MAb) induced marked apoptosis in HHV-6-inoculated cells. Transmission electron microscopy showed characteristics of apoptosis, such as chromatin condensation and fragmentation of nuclei, but virus particles were hardly detected in apoptotic cells. Two-color flow cytometric analysis using anti-HHV-6 MAb and propidium iodide revealed that DNA fragmentation was present predominantly in uninfected cells but not in productively HHV-6-infected cells. In addition, JJHAN cells incubated with UV light-irradiated and ultracentrifuged culture supernatant of HHV-6-infected cells appeared to undergo apoptosis. The present study demonstrated that both HHV-6 variants A and B induce apoptosis in CD4+ T cells by indirect mechanisms, as reported recently in human immunodeficiency virus type 1 infection. PMID:9094650

  10. Solamargine triggers hepatoma cell death through apoptosis

    PubMed Central

    XIE, XIAODONG; ZHU, HAITAO; YANG, HUIJIAN; HUANG, WENSI; WU, YINGYING; WANG, YING; LUO, YANLING; WANG, DONGQING; SHAO, GENBAO

    2015-01-01

    Solamargine (SM), a steroidal alkaloid glycoside extracted from the traditional Chinese herb Solanum incanum, has been evidenced to inhibit the growth and induce apoptosis in a number of human cancer cell lines. In the present study, the anticancer effect of SM and underlying molecular mechanism of SM-induced apoptosis were investigated on the human hepatocellular carcinoma cells, SMMC7721 and HepG2. The proliferation effects of SM on the SMMC7721 and HepG2 cell lines were evaluated using MTT and colony formation assays. In addition, the percentage of apoptosis was measured using an Annexin V/propidium iodide staining method and the cell cycle distribution mediated by SM was analyzed using flow cytometry. The expression levels of B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X protein (Bax), caspase-3, caspase-9, proliferating cell nuclear antigen (pcna) and Ki67 proteins were examined to further demonstrate the proliferate and apoptosis effects of SM on the hepatoma cells. The results indicated that SM effectively inhibited hepatoma cell proliferation and promoted apoptosis. SM resulted in cell cycle arrest at the G2/M phase in the two cell lines. In addition, SM downregulated the levels of proliferation-associated (Ki67 and pcna) and anti-apoptotic (Bcl-2) proteins, and promoted the activity of apoptosis-associated proteins (Bax, caspase-3 and caspase-9). Therefore, the activation of the Bcl-2/Bax and caspase signaling pathways may be involved in the SM-induced apoptosis of hepatoma cells. PMID:26170994

  11. Cardiomyocytes undergo apoptosis in human immunodeficiency virus cardiomyopathy through mitochondrion- and death receptor-controlled pathways

    PubMed Central

    Twu, Cheryl; Liu, Nancy Q.; Popik, Waldemar; Bukrinsky, Michael; Sayre, James; Roberts, Jaclyn; Rania, Shammas; Bramhandam, Vishnu; Roos, Kenneth P.; MacLellan, W. Robb; Fiala, Milan

    2002-01-01

    We investigated 18 AIDS hearts (5 with and 13 without cardiomyopathy) by using immunocytochemistry and computerized image analysis regarding the roles of HIV-1 proteins and tumor necrosis factor ligands in HIV cardiomyopathy (HIVCM). HIVCM and cardiomyocyte apoptosis were significantly related to each other and to the expression by inflammatory cells of gp120 and tumor necrosis factor-α. In HIVCM heart, active caspase 9, a component of the mitochondrion-controlled apoptotic pathway, and the elements of the death receptor-mediated pathway, tumor necrosis factor-α and Fas ligand, were expressed strongly on macrophages and weakly on cardiomyocytes. HIVCM showed significantly greater macrophage infiltration and cardiomyocyte apoptosis rate compared with non-HIVCM. HIV-1 entered cultured neonatal rat ventricular myocytes by macropinocytosis but did not replicate. HIV-1- or gp120-induced apoptosis of rat myocytes through a mitochondrion-controlled pathway, which was inhibited by heparin, AOP-RANTES, or pertussis toxin, suggesting that cardiomyocyte apoptosis is induced by signaling through chemokine receptors. In conclusion, in patients with HIVCM, cardiomyocytes die through both mitochondrion- and death receptor-controlled apoptotic pathways. PMID:12379743

  12. Apoptosis and Beyond: Cytometry in Studies of Programmed Cell Death

    PubMed Central

    Wlodkowic, Donald; Telford, William; Skommer, Joanna; Darzynkiewicz, Zbigniew

    2012-01-01

    A cell undergoing apoptosis demonstrates multitude of characteristic morphological and biochemical features, which vary depending on the inducer of apoptosis, cell type and the “time window” at which the process of apoptosis is observed. Because the gross majority of apoptotic hallmarks can be revealed by flow and image cytometry, the cytometric methods become a technology of choice in diverse studies of cellular demise. Variety of cytometric methods designed to identify apoptotic cells, detect particular events of apoptosis and probe mechanisms associated with this mode of cell death have been developed during the past two decades. In the present review, we outline commonly used methods that are based on the assessment of mitochondrial transmembrane potential, activation of caspases, DNA fragmentation, and plasma membrane alterations. We also present novel developments in the field such as the use of cyanine SYTO and TO-PRO family of probes. Strategies of selecting the optimal multiparameter approaches, as well as potential difficulties in the experimental procedures, are thoroughly summarized. PMID:21722800

  13. NMR exposure sensitizes tumor cells to apoptosis.

    PubMed

    Ghibelli, L; Cerella, C; Cordisco, S; Clavarino, G; Marazzi, S; De Nicola, M; Nuccitelli, S; D'Alessio, M; Magrini, A; Bergamaschi, A; Guerrisi, V; Porfiri, L M

    2006-03-01

    NMR technology has dramatically contributed to the revolution of image diagnostic. NMR apparatuses use combinations of microwaves over a homogeneous strong (1 Tesla) static magnetic field. We had previously shown that low intensity (0.3-66 mT) static magnetic fields deeply affect apoptosis in a Ca2+ dependent fashion (Fanelli et al., 1999 FASEBJ., 13;95-102). The rationale of the present study is to examine whether exposure to the static magnetic fields of NMR can affect apoptosis induced on reporter tumor cells of haematopoietic origin. The impressive result was the strong increase (1.8-2.5 fold) of damage-induced apoptosis by NMR. This potentiation is due to cytosolic Ca2+ overload consequent to NMR-promoted Ca2+ influx, since it is prevented by intracellular (BAPTA-AM) and extracellular (EGTA) Ca2+ chelation or by inhibition of plasma membrane L-type Ca2+ channels. Three-days follow up of treated cultures shows that NMR decrease long term cell survival, thus increasing the efficiency of cytocidal treatments. Importantly, mononuclear white blood cells are not sensitised to apoptosis by NMR, showing that NMR may increase the differential cytotoxicity of antitumor drugs on tumor vs normal cells. This strong, differential potentiating effect of NMR on tumor cell apoptosis may have important implications, being in fact a possible adjuvant for antitumor therapies. PMID:16528477

  14. Apoptosis and proliferation of oligodendrocyte progenitor cells in the irradiated rodent spinal cord

    SciTech Connect

    Atkinson, Shelley L.; Li Yuqing; Wong, C. Shun . E-mail: shun.wong@sw.ca

    2005-06-01

    Purpose: Oligodendrocytes undergo early apoptosis after irradiation. The aim of this study was to determine the relationship between oligodendroglial apoptosis and proliferation of oligodendrocyte progenitor cells (OPC) in the irradiated central nervous system. Methods and Materials: Adult rats and p53 transgenic mice were given single doses of 2 Gy, 8 Gy, or 22 Gy to the cervical spinal cord. Apoptosis was assessed using TUNEL (Tdt-mediated dUTP terminal nick-end labeling) staining or by examining nuclear morphology. Oligodendrocyte progenitor cells were identified with an NG2 antibody or by in situ hybridization for platelet-derived growth factor receptor {alpha}. Proliferation of OPC was assessed by in vivo bromodeoxyuridine (BrdU) labeling and subsequent immunohistochemistry. Because radiation-induced apoptosis of oligodendroglial cells is p53 dependent, p53 transgenic mice were used to study the relationship between apoptosis and cell proliferation. Results: Oligodendrocyte progenitor cells underwent apoptosis within 24 h of irradiation in the rat. That did not result in a change in OPC density at 24 h. Oligodendrocyte progenitor cell density was significantly reduced by 2-4 weeks, but showed recovery by 6 weeks after irradiation. An increase in BrdU-labeled cells was observed at 2 weeks after 8 Gy or 22 Gy, and proliferating cells in the rat spinal cord were immunoreactive for NG2. The mouse spinal cord showed a similar early cell proliferation after irradiation. No difference was observed in the proliferation response in the spinal cord of p53 -/- mice compared with wild type animals. Conclusions: Oligodendroglial cells undergo early apoptosis and OPC undergo early proliferation after ionizing radiation. However, apoptosis is not likely to be the trigger for early proliferation of OPC in the irradiated central nervous system.

  15. Apoptosis induced by dioscin in Hela cells.

    PubMed

    Cai, Jing; Liu, Mingjie; Wang, Zhao; Ju, Yong

    2002-02-01

    Dioscin, a saponin extracted from the root of Polygonatum Zanlanscianense Pamp, markedly inhibited proliferation of Hela cells. The results indicated that Hela cells underwent apoptosis in dose- and time-dependent manners when treated with Dioscin. Caspase-3, -8 and -9 activities were also detected. The low enzymatic activity of caspase-8 and high activity of caspase-9 showed that the mitochondrial pathway was activated in apoptosis. The reduced expression of the survival protein Bcl-2 also confirmed this result. These studies may be significant in finding a new drug to treat human cervical cancer. PMID:11853164

  16. Cord Blood Stem Cell-Mediated Induction of Apoptosis in Glioma Downregulates X-Linked Inhibitor of Apoptosis Protein (XIAP)

    PubMed Central

    Dasari, Venkata Ramesh; Velpula, Kiran Kumar; Kaur, Kiranpreet; Fassett, Daniel; Klopfenstein, Jeffrey D.; Dinh, Dzung H.; Gujrati, Meena; Rao, Jasti S.

    2010-01-01

    Background XIAP (X-linked inhibitor of apoptosis protein) is one of the most important members of the apoptosis inhibitor family. XIAP is upregulated in various malignancies, including human glioblastoma. It promotes invasion, metastasis, growth and survival of malignant cells. We hypothesized that downregulation of XIAP by human umbilical cord blood mesenchymal stem cells (hUCBSC) in glioma cells would cause them to undergo apoptotic death. Methodology/Principal Findings We observed the effect of hUCBSC on two malignant glioma cell lines (SNB19 and U251) and two glioma xenograft cell lines (4910 and 5310). In co-cultures of glioma cells with hUCBSC, proliferation of glioma cells was significantly inhibited. This is associated with increased cytotoxicity of glioma cells, which led to glioma cell death. Stem cells induced apoptosis in glioma cells, which was evaluated by TUNEL assay, FACS analyses and immunoblotting. The induction of apoptosis is associated with inhibition of XIAP in co-cultures of hUCBSC. Similar results were obtained by the treatment of glioma cells with shRNA to downregulate XIAP (siXIAP). Downregulation of XIAP resulted in activation of caspase-3 and caspase-9 to trigger apoptosis in glioma cells. Apoptosis is characterized by the loss of mitochondrial membrane potential and upregulation of mitochondrial apoptotic proteins Bax and Bad. Cell death of glioma cells was marked by downregulation of Akt and phospho-Akt molecules. We observed similar results under in vivo conditions in U251- and 5310-injected nude mice brains, which were treated with hUCBSC. Under in vivo conditions, Smac/DIABLO was found to be colocalized in the nucleus, showing that hUCBSC induced apoptosis is mediated by inhibition of XIAP and activation of Smac/DIABLO. Conclusions/Significance Our results indicate that downregulation of XIAP by hUCBSC treatment induces apoptosis, which led to the death of the glioma cells and xenograft cells. This study demonstrates the therapeutic

  17. Primary and liver metastasis-derived cell lines from KRasG12D; Trp53R172H; Pdx-1 Cre animals undergo apoptosis in response to triptolide

    PubMed Central

    Sangwan, Veena; Banerjee, Sulagna; Jensen, Kelsey; Chen, Zhiyu; Chugh, Rohit; Dudeja, Vikas; Vickers, Selwyn M.; Saluja, Ashok K.

    2015-01-01

    Objectives Pancreatic cancer has a five year survival rate of less than 5%, partly due to limited chemotherapeutic options, thereby highlighting the need for novel therapies. Triptolide, a diterpene triepoxide derived from a Chinese herb has shown great promise in preclinical testing against pancreatic cancer using immune compromised animals. Results In this study, we tested the ability of triptolide to induce cell death in cell lines derived from a primary tumor and adjacent liver metastases of immuno-competent animals (KRasG12D; Trp52R172H; Pdx-1 Cre (KPC)). Both cell lines were more aggressive in their ability to form tumors when compared to other pancreatic cancer cell lines, and showed constitutive activation of the NFkB pathway. Triptolide induced apoptotic cell death in both cell lines, as evidenced by decreased cell viability and increased caspase 3/7 activity, Annexin V positivity, and increased TUNEL positivity in tumors from KPC animals treated with Minnelide. Additionally, triptolide decreased levels of HSP70, its transcription factor HSF1, and the anti-apoptotic proteins Bcl-xL, Bcl-2 and Mcl-1, known to be up-regulated in pancreatic cancer. Conclusion The ability of triptolide to cause cell death in cell lines derived from immune-competent animals further validates its potential as a novel agent against pancreatic cancer. PMID:25875797

  18. Apoptosis in male germ cells in response to cyclin A1-deficiency and cell cycle arrest.

    PubMed

    Salazar, Glicella; Liu, Dong; Liao, Ching; Batkiewicz, Leah; Arbing, Rachel; Chung, Sanny S W; Lele, Karen; Wolgemuth, Debra J

    2003-10-15

    Male mice homozygous for a mutated allele of the cyclin A1 gene (Ccna1) are sterile due to a block in cell cycle progression before the first meiotic division. Meiosis arrest in Ccna1(-/-) spermatocytes is associated with desynapsis abnormalities, lowered MPF activity, and apoptosis as evidenced by TUNEL-positive staining. With time, adult testicular tubules exhibit severe degeneration: some tubules in the older animals are almost devoid of germ cells at various stages of spermatogenesis. The mechanisms by which the cells sense the cell cycle arrest and the regulation of the decision to undergo cell death are under investigation. PMID:14555236

  19. Oxidative status in granulosa cells of infertile women undergoing IVF.

    PubMed

    Karuputhula, Narendra Babu; Chattopadhyay, Ratna; Chakravarty, Baidyanath; Chaudhury, Koel

    2013-04-01

    Studies on elevated reactive oxygen species (ROS) levels in granulosa cells (GC) and its subsequent effect on fertilization are limited. Oxidative stress (OS) mediated alterations in GC of infertile women undergoing in vitro fertilization (IVF) and embryo transfer (ET) was investigated. GC were obtained from 28 women with endometriosis (Group A), 26 women with polycystic ovary syndrome (PCOS) (Group B), and 32 women with tubal factor infertility (Group C). GC characteristics including cell count, viability, morphology and number of oocytes retrieved, and oocyte quality were assessed. OS parameters such as ROS, mitochondrial membrane potential (MMP), and DNA fragmentation were also studied and IVF outcome parameters assessed. An ∼20 fold increase in GC ROS generation was observed in Group B as compared to Group C. Though not as high as Group B, Group A also showed significantly high ROS levels compared with Group C. More than 100-fold decrease in MMP in Group B compared with Group C was observed. A similar trend was observed in Group A, where MMP decreased 7 fold. Significant apoptosis was evident in Groups A and B supported by depolarization of MMP and significant increase in DNA damage. IVF outcome parameters including fertilization rate, good quality embryo formation rate, and pregnancy outcome were adversely affected in Group B. It is hypothesized that ∼20 fold increase in ROS generation in GC of PCOS women plays an adverse role in affecting the IVF success rate. It was of note that the IVF outcome parameters of women with endometriosis were not affected. PMID:23278116

  20. Control of apoptosis by asymmetric cell division.

    PubMed

    Hatzold, Julia; Conradt, Barbara

    2008-04-01

    Asymmetric cell division and apoptosis (programmed cell death) are two fundamental processes that are important for the development and function of multicellular organisms. We have found that the processes of asymmetric cell division and apoptosis can be functionally linked. Specifically, we show that asymmetric cell division in the nematode Caenorhabditis elegans is mediated by a pathway involving three genes, dnj-11 MIDA1, ces-2 HLF, and ces-1 Snail, that directly control the enzymatic machinery responsible for apoptosis. Interestingly, the MIDA1-like protein GlsA of the alga Volvox carteri, as well as the Snail-related proteins Snail, Escargot, and Worniu of Drosophila melanogaster, have previously been implicated in asymmetric cell division. Therefore, C. elegans dnj-11 MIDA1, ces-2 HLF, and ces-1 Snail may be components of a pathway involved in asymmetric cell division that is conserved throughout the plant and animal kingdoms. Furthermore, based on our results, we propose that this pathway directly controls the apoptotic fate in C. elegans, and possibly other animals as well. PMID:18399720

  1. Apoptosis as a mechanism of cytolysis of tumor cells by a pathogenic free-living amoeba.

    PubMed Central

    Alizadeh, H; Pidherney, M S; McCulley, J P; Niederkorn, J Y

    1994-01-01

    Previous studies have shown that trophozoites of the pathogenic free-living amoeba Acanthamoeba castellanii rapidly lysed a variety of tumor cells in vitro. Tumor cells undergoing parasite-mediated lysis displayed characteristic cell membrane blebbing reminiscent of apoptosis. The present investigation examined the role of apoptosis (programmed cell death) in Acanthamoeba-mediated tumor cell lysis. The results showed that more than 70% of tumor cell DNA was fragmented following exposure to Acanthamoeba cell extracts. By contrast, only 7% of untreated control cells underwent DNA fragmentation. DNA fragmentation increased significantly in a dose-dependent fashion following concentration of the parasite extract. Apoptosis was also confirmed by DNA ladder formation. Characteristic DNA ladders, consisting of multimers of approximately 180 to 200 bp, were produced by tumor cells exposed to Acanthamoeba cell extracts. The morphology of tumor cell lysis was examined by light and scanning electron microscopy. Tumor cells exposed to parasite extract displayed morphological features characteristic of apoptosis including cell shrinkage, cell membrane blebbing, formation of apoptotic bodies, and nuclear condensation. By contrast, similar effects were not found in tumor cells exposed to extract similarly prepared from normal mammalian cells (i.e., human keratocytes). The results suggest that at least one species of pathogenic free-living amoeba is able to lyse tumor cells by a process that culminates in apoptosis. Images PMID:8132336

  2. Ambivalent Outcomes of Cell Apoptosis: A Barrier or Blessing in Malaria Progression

    PubMed Central

    Kakani, Parik; Suman, Sneha; Gupta, Lalita; Kumar, Sanjeev

    2016-01-01

    The life cycle of Plasmodium in two evolutionary distant hosts, mosquito, and human, is a complex process. It is regulated at various stages of developments by a number of diverged mechanisms that ultimately determine the outcome of the disease. During the development processes, Plasmodium invades a variety of cells in two hosts. The invaded cells tend to undergo apoptosis and are subsequently removed from the system. This process also eliminates numerous parasites along with these apoptotic cells as a part of innate defense against the invaders. Plasmodium should escape the invaded cell before it undergoes apoptosis or it should manipulate host cell apoptosis for its survival. Interestingly, both these phenomena are evident in Plasmodium at different stages of development. In addition, the parasite also exhibits altruistic behavior and triggers its own killing for the selection of the best ‘fit’ progeny, removal of the ‘unfit’ parasites to conserve the nutrients and to support the host survival. Thus, the outcomes of cell apoptosis are ambivalent, favorable as well as unfavorable during malaria progression. Here we discuss that the manipulation of host cell apoptosis might be helpful in the regulation of Plasmodium development and will open new frontiers in the field of malaria research. PMID:27014225

  3. Wavelength-dependent backscattering measurements for quantitative real-time monitoring of apoptosis in living cells

    NASA Astrophysics Data System (ADS)

    Mulvey, Christine S.; Sherwood, Carly A.; Bigio, Irving J.

    2009-11-01

    Apoptosis-programmed cell death-is a cellular process exhibiting distinct biochemical and morphological changes. An understanding of the early morphological changes that a cell undergoes during apoptosis can provide the opportunity to monitor apoptosis in tissue, yielding diagnostic and prognostic information. There is avid interest regarding the involvement of apoptosis in cancer. The initial response of a tumor to successful cancer treatment is often massive apoptosis. Current apoptosis detection methods require cell culture disruption. Our aim is to develop a nondisruptive optical method to monitor apoptosis in living cells and tissues. This would allow for real-time evaluation of apoptotic progression of the same cell culture over time without alteration. Elastic scattering spectroscopy (ESS) is used to monitor changes in light-scattering properties of cells in vitro due to apoptotic morphology changes. We develop a simple instrument capable of wavelength-resolved ESS measurements from cell cultures in the backward direction. Using Mie theory, we also develop an algorithm that extracts the size distribution of scatterers in the sample. The instrument and algorithm are validated with microsphere suspensions. For cell studies, Chinese hamster ovary (CHO) cells are cultured to confluence on plates and are rendered apoptotic with staurosporine. Backscattering measurements are performed on pairs of treated and control samples at a sequence of times up to 6-h post-treatment. Initial results indicate that ESS is capable of discriminating between treated and control samples as early as 10- to 15-min post-treatment, much earlier than is sensed by standard assays for apoptosis. Extracted size distributions from treated and control samples show a decrease in Rayleigh and 150-nm scatterers, relative to control samples, with a corresponding increase in 200-nm particles. Work continues to correlate these size distributions with underlying morphology. To our knowledge, this

  4. Resistance to etoposide-induced apoptosis in a Burkitt's lymphoma cell line.

    PubMed

    Zhao, E G; Song, Q; Cross, S; Misko, I; Lees-Miller, S P; Lavin, M F

    1998-08-31

    Burkitt's lymphoma cells that vary in their phenotypic characteristics show significantly different degrees of susceptibility to radiation-induced apoptosis. Propensity to undergo apoptosis is reflected in the degradation of substrates such as DNA-dependent protein kinase but the status of bcl-2, c-myc and p53 has been uninformative. In this study, we have focused on 2 Epstein-Barr virus (EBV)-associated Burkitt's cell lines, one (WW2) susceptible and the other (BL29) resistant to etoposide-induced apoptosis. Differences in expression of BHRF1, an EBV gene that is homologous to the Bcl-2 proto-oncogene and known to inhibit apoptosis, or changes in apoptosis inhibitory proteins (IAPs), did not appear to account for the difference in susceptibility in the 2 cell lines. Cytoplasmic extracts from etoposide-treated WW2 cells caused apoptotic changes in nuclei isolated from either BL29 or WW2 cells, whereas extracts from BL29 cells failed to do so. In addition, extracts from etoposide-treated WW2 cells degraded the catalytic subunit of DNA-dependent protein kinase (DNA-PKcs), an important indicator of apoptosis, but this protein was resistant to degradation by BL29 extracts. It appears likely that caspase 3 (CPP32) is involved in this degradation since it was activated only in the apoptosis susceptible cells and the pattern of cleavage of DNA-PKcs was similar to that reported previously with recombinant caspase 3. As observed previously, addition of caspase 3 to nuclei failed to induce morphological changes indicative of apoptosis, but addition of caspase 3 to nuclei in the presence of extract from the resistant cells led to apoptotic changes. We conclude that resistance to apoptosis in BL29 cells is due to a failure of etoposide to activate upstream effectors of caspase activity. PMID:9688310

  5. Is Hydrogen Peroxide a Suitable Apoptosis Inducer for All Cell Types?

    PubMed Central

    Xiang, Jinmei; Wan, Chunyun; Guo, Rui

    2016-01-01

    Hydrogen peroxide is currently the most widely used apoptosis inducer due to its broad cytotoxic efficacy against nearly all cell types. However, equivalent cytotoxicity is achieved over a wide range of doses, although the reasons for this differential sensitivity are not always clear. In this study, three kinds of cells, the 293T cell line, primary fibroblasts, and terminally differentiated myocardial cells, were treated with a wide range of H2O2 doses. Times to apoptosis initiation and end were measured cytochemically and the changes in expression of caspase-9, P53, NF-κB, and RIP were determined by RT-PCR. The 293T cell line was the most sensitive to H2O2, undergoing necroptosis and/or apoptosis at all concentrations from 0.1 to 1.6 mM. At > 0.4 mM, H2O2 also caused necroptosis in primary cells. At < 0.4 mM, however, primary cells exhibited classic signs of apoptosis, although they tended to survive for 36 hours in < 0.2 mM H2O2. Thus, H2O2 is a broadly effective apoptosis inducer, but the dose range differs by cell type. For cell lines, a low dose is required and the exposure time must be reduced compared to primary cells to avoid cell death primarily by necroptosis or necrosis. PMID:27595106

  6. Infection of human fallopian tube epithelial cells with Neisseria gonorrhoeae protects cells from tumor necrosis factor alpha-induced apoptosis.

    PubMed

    Morales, Priscilla; Reyes, Paz; Vargas, Macarena; Rios, Miguel; Imarai, Mónica; Cardenas, Hugo; Croxatto, Horacio; Orihuela, Pedro; Vargas, Renato; Fuhrer, Juan; Heckels, John E; Christodoulides, Myron; Velasquez, Luis

    2006-06-01

    Following infection with Neisseria gonorrhoeae, bacteria may ascend into the Fallopian tubes (FT) and induce salpingitis, a major cause of infertility. In the FT, interactions between mucosal epithelial cells and gonococci are pivotal events in the pathogen's infection cycle and the inflammatory response. In the current study, primary FT epithelial cells were infected in vitro with different multiplicities of infection (MOI) of Pil+ Opa+ gonococci. Bacteria showed a dose-dependent association with cells and induced the secretion of tumor necrosis factor alpha (TNF-alpha). A significant finding was that gonococcal infection (MOI = 1) induced apoptosis in approximately 30% of cells, whereas increasing numbers of bacteria (MOI = 10 to 100) did not induce apoptosis. Apoptosis was observed in only 11% of cells with associated bacteria, whereas >84% of cells with no adherent bacteria were apoptotic. TNF-alpha was a key contributor to apoptosis, since (i) culture supernatants from cells infected with gonococci (MOI = 1) induced apoptosis in naïve cultures, suggesting that a soluble factor was responsible; (ii) gonococcal infection-induced apoptosis was inhibited with anti-TNF-alpha antibodies; and (iii) the addition of exogenous TNF-alpha induced apoptosis, which was inhibited by the presence of increasing numbers of bacteria (MOI = 10 to 100). These data suggest that TNF-alpha-mediated apoptosis of FT epithelial cells is likely a primary host defense mechanism to prevent pathogen colonization. However, epithelial cell-associated gonococci have evolved a mechanism to protect the cells from undergoing TNF-alpha-mediated apoptosis, and this modulation of the host innate response may contribute to establishment of infection. Understanding the antiapoptotic mechanisms used by Neisseria gonorrhoeae will inform the pathogenesis of salpingitis and could suggest new intervention strategies for prevention and treatment of the disease. PMID:16714596

  7. Monitoring drug induced apoptosis and treatment sensitivity in non-small cell lung carcinoma using dielectrophoresis.

    PubMed

    Taruvai Kalyana Kumar, Rajeshwari; Liu, Shanshan; Minna, John D; Prasad, Shalini

    2016-09-01

    Non-invasive real time methods for characterizing biomolecular events that contribute towards apoptotic kinetics would be of significant importance in the field of cancer biology. Effective drug-induced apoptosis is an important factor for establishing the relationship between cancer genetics and treatment sensitivity. The objective of this study was to develop a non-invasive technique to characterize cancer cells that are undergoing drug-induced apoptosis. We used dielectrophoresis to determine apoptotic cells as early as 2h post drug treatment as compared to 24h with standard flow cytometry method using non-small cell lung cancer (NSCLC) adenocarcinoma cell line (HCC1833) as a study model. Our studies have shown significant differences in apoptotic cells by chromatin condensation, formation of apoptotic bodies and exposure of phosphatidylserine (PS) on the extracellular surface when the cells where treated with a potent Bcl-2 family inhibitor drug (ABT-263). Time lapse dielectrophoretic studies were performed over 24h period after exposure to ABT-263 at clinically relevant concentrations. The dielectrophoretic studies were compared to Annexin-V FITC flow assay for the detection of PS in mid-stage apoptosis using flow cytometry. As a result of physical and biochemical changes, inherent dielectric properties of cells undergoing varying stages of apoptosis showed amplified changes in their cytoplasmic and membrane capacitance. In addition, zeta potential of these fixed isolated cells was measured to obtain direct correlation to biomolecular events. PMID:27262539

  8. Adipose-derived stromal cells inhibit prostate cancer cell proliferation inducing apoptosis

    SciTech Connect

    Takahara, Kiyoshi; Ii, Masaaki; Inamoto, Teruo; Komura, Kazumasa; Ibuki, Naokazu; Minami, Koichiro; Uehara, Hirofumi; Hirano, Hajime; Nomi, Hayahito; Kiyama, Satoshi; Asahi, Michio; Azuma, Haruhito

    2014-04-18

    Highlights: • AdSC transplantation exhibits inhibitory effect on tumor progressions of PCa cells. • AdSC-induced PCa cell apoptosis may occur via the TGF-β signaling pathway. • High expression of the TGF-β1 gene in AdSCs. - Abstract: Mesenchymal stem cells (MSCs) have generated a great deal of interest in the field of regenerative medicine. Adipose-derived stromal cells (AdSCs) are known to exhibit extensive proliferation potential and can undergo multilineage differentiation, sharing similar characteristics to bone marrow-derived MSCs. However, as the effect of AdSCs on tumor growth has not been studied sufficiently, we assessed the degree to which AdSCs affect the proliferation of prostate cancer (PCa) cell. Human AdSCs exerted an inhibitory effect on the proliferation of androgen-responsive (LNCaP) and androgen-nonresponsive (PC3) human PCa cells, while normal human dermal fibroblasts (NHDFs) did not, and in fact promoted PCa cell proliferation to a degree. Moreover, AdSCs induced apoptosis of LNCaP cells and PC3 cells, activating the caspase3/7 signaling pathway. cDNA microarray analysis suggested that AdSC-induced apoptosis in both LNCaP and PC3 cells was related to the TGF-β signaling pathway. Consistent with our in vitro observations, local transplantation of AdSCs delayed the growth of tumors derived from both LNCaP- and PC3-xenografts in immunodeficient mice. This is the first preclinical study to have directly demonstrated that AdSC-induced PCa cell apoptosis may occur via the TGF-β signaling pathway, irrespective of androgen-responsiveness. Since autologous AdSCs can be easily isolated from adipose tissue without any ethical concerns, we suggest that therapy with these cells could be a novel approach for patients with PCa.

  9. Active Akt and functional p53 modulate apoptosis in Abelson virus-transformed pre-B cells.

    PubMed

    Gong, Li; Unnikrishnan, Indira; Raghavan, Anuradha; Parmar, Kalindi; Rosenberg, Naomi

    2004-02-01

    Suppression of apoptosis is an important feature of the Abelson murine leukemia virus (Ab-MLV) transformation process. During multistep transformation, Ab-MLV-infected pre-B cells undergo p53-dependent apoptosis during the crisis phase of transformation. Even once cells are fully transformed, an active v-Abl protein tyrosine kinase is required to suppress apoptosis because cells transformed by temperature-sensitive (ts) kinase mutants undergo rapid apoptosis after a shift to the nonpermissive temperature. However, inactivation of the v-Abl protein by a temperature shift interrupts signals transmitted via multiple pathways, making it difficult to identify those that are critically important for the suppression of apoptosis. To begin to dissect these pathways, we tested the ability of an SH2 domain Ab-MLV mutant, P120/R273K, to rescue aspects of the ts phenotype of pre-B cells transformed by the conditional kinase domain mutant. The P120/R273K mutant suppressed apoptosis at the nonpermissive temperature, a phenotype correlated with its ability to activate Akt. Apoptosis also was suppressed at the nonpermissive temperature by constitutively active Akt and in p53-null pre-B cells transformed with the ts kinase domain mutant. These data indicate that an intact Src homology 2 (SH2) domain is not critical for apoptosis suppression and suggest that signals transmitted through Akt and p53 play an important role in the response. PMID:14747529

  10. Artesunate induces AIF-dependent apoptosis in A549 cells

    NASA Astrophysics Data System (ADS)

    Zhou, Chen-juan; Chen, Tong-Sheng

    2012-03-01

    Artesunate (ART), a semi-synthetic derivative of the sesquiterpene artemisinin extracted from the Chinese herb Artemisia annua, exerts a broad spectrum of clinical activity against human cancers. It has been shown that ART induces cancer cells death through apoptosis pathway. This study investigated whether ART treatment induced reactive oxygen species (ROS)-dependent cell death in the apoptosis fashion in human lung adenocarconoma A549 cell line and the proapoptotic protein apoptosis inducing factor (AIF) is involved in ART-induced apoptosis. Cells treated with ART exhibited typical apoptotic morphology as chromatin condensation, margination and shrunken nucleus. ART treatment also induced a loss of mitochondrial membrane potential and AIF release from mitochondria. Silencing AIF can remarkable attenuated ART-induced apoptosis. Collectively, ART induces apoptosis by caspase-independent intrinsic pathway in A549 cells.

  11. Suppression of Apoptosis by Basement Membrane Requires three-dimensional Tissue Organization and Withdrawal from the Cell Cycle

    SciTech Connect

    Boudreau, N.; Werb, Z.; Bissell, M.J.

    1995-12-28

    The basement membrane (BM) extracellular matrix induces differentiation and suppresses apoptosis in mammary epithelial cells, whereas cells lacking BM lose their differentiated phenotype and undergo apoptosis. Addition of purified BM components, which are known to induce {beta}-casein expression, did not prevent apoptosis, indicating that a more complex BM was necessary. A comparison of culture conditions where apoptosis would or would not occur allowed us to relate inhibition of apoptosis to a complete withdrawal from the cell cycle, which was observed only when cells acquired a three-dimensional alveolar structure in response to BM. In the absence of this morphology, both the G1 cyclin kinase inhibitor p21/WAF-I and positive proliferative signals including c-myc and cyclin Dl were expressed and the retinoblastoma protein (Rb) continued to be hyperphosphorylated. When we overexpressed either c-myc in quiescent cells or p21 when cells were still cycling, apoptosis was induced. In the absence of three-dimensional alveolar structures, mammary epithelial cells secrete a number of factors including transforming growth factor a and tenascin, which when added exogenously to quiescent cells induced expression of c-myc and interleukin-{beta}1-converting enzyme (ICE) mRNA and led to apoptosis. These experiments demonstrate that a correct tissue architecture is crucial for long-range homeostasis, suppression of apoptosis, and maintenance of differentiated phenotype.

  12. Vimentin Is Involved in Peptidylarginine Deiminase 2-Induced Apoptosis of Activated Jurkat Cells

    PubMed Central

    Hsu, Pei-Chen; Liao, Ya-Fan; Lin, Chin-Li; Lin, Wen-Hao; Liu, Guang-Yaw; Hung, Hui-Chih

    2014-01-01

    Peptidylarginine deiminase type 2 (PADI2) deiminates (or citrullinates) arginine residues in protein to citrulline residues in a Ca2+-dependent manner, and is found in lymphocytes and macrophages. Vimentin is an intermediate filament protein and a well-known substrate of PADI2. Citrullinated vimentin is found in ionomycin-induced macrophage apoptosis. Citrullinated vimentin is the target of anti-Sa antibodies, which are specific to rheumatoid arthritis, and play a critical role in the pathogenesis of the disease. To investigate the role of PADI2 in apoptosis, we generated a Jurkat cell line that overexpressed the PADI2 transgene from a tetracycline-inducible promoter, and used a combination of 12-O-tetradecanoylphorbol-13-acetate and ionomycin to activate Jurkat cells. We found that PADI2 overexpression reduced the cell viability of activated Jurkat cells in a dose- and time-dependent manner. The PADI2-overexpressed and -activated Jurkat cells presented typical manifestations of apoptosis, and exhibited greater levels of citrullinated proteins, including citrullinated vimentin. Vimentin overexpression rescued a portion of the cells from apoptosis. In conclusion, PADI2 overexpression induces apoptosis in activated Jurkat cells. Vimentin is involved in PADI2-induced apoptosis. Moreover, PADI2-overexpressed Jurkat cells secreted greater levels of vimentin after activation, and expressed more vimentin on their cell surfaces when undergoing apoptosis. Through artificially highlighting PADI2 and vimentin, we demonstrated that PADI2 and vimentin participate in the apoptotic mechanisms of activated T lymphocytes. The secretion and surface expression of vimentin are possible ways of autoantigen presentation to the immune system. PMID:24850148

  13. Ethanol promotes T cell apoptosis through the mitochondrial pathway

    PubMed Central

    Kapasi, Aditi A; Patel, Geeta; Goenka, Anuj; Nahar, Nilay; Modi, Neeraj; Bhaskaran, Madhu; Reddy, Krishna; Franki, Nicholas; Patel, Jaimita; Singhal, Pravin C

    2003-01-01

    Clinical reports suggest that acute ethanol intoxication is often associated with lymphopenia. Previously, ethanol was reported to invoke thymocyte apoptosis. We studied the effect of ethanol on T cell apoptosis. In addition, we evaluated the molecular mechanism of ethanol-induced T cell apoptosis. Human T cells harvested from healthy subjects after an alcohol drinking binge showed enhanced T cell apoptosis (before, 0·4 ± 0·2% versus after, 19·6 ± 2·5% apoptotic lymphocytes/field; P < 0·001). In in vitro studies, ethanol in a concentration of 50 mm and higher enhanced the apoptosis of Jurkat cells. DNA isolated from ethanol-treated Jurkat cells displayed integer multiples of 180 base pairs. Ethanol decreased Jurkat cell expression of Bcl-2, whereas ethanol increased Jurkat cell expression of Bax. Jurkat cells treated with ethanol also showed translocation of cytochrome C into cytosol. Moreover, a caspase-9 inhibitor partially inhibited ethanol-induced Jurkat cell apoptosis. In in vivo studies, after binge drinking, T cell expression of Bcl-2 also decreased. In addition, binge drinking induced the cleavage of caspase-3, suggesting activation of caspase-3 in T cells. These results suggest that ethanol promotes T cell apoptosis through the activation of intrinsic or mitochondrial pathway. PMID:12603597

  14. X-ray-induced cell death: Apoptosis and necrosis

    SciTech Connect

    Nakano, Hisako; Shinohara, Kunio

    1994-10-01

    X-ray-induced cell death in MOLT-4N1, a subclone of MOLT-4 cells, and M10 cells was studied with respect to their modes of cell death, apoptosis and necrosis. MOLT-4N1 cells showed radiosensitivity similar to that of M10 cells, a radiosensitive mutant of L5178Y, as determined by the colony formation assay. Analysis of cell size demonstrated that MOLT-4N1 cells increased in size at an early stage after irradiation and then decreased to a size smaller than that of control cells, whereas the size of irradiated M10 cells increased continuously. Apoptosis detected by morphological changes and DNA ladder formation (the cleavage of DNA into oligonucleosomal fragments) occurred in X-irradiated MOLT-4N1 cells but not in M10 cells. Pulsed-field gel electrophoresis showed that the ladder formation involved an intermediate-sized DNA (about 20 kbp). Most of the DNA was detected at the origin in both methods of electrophoresis in the case of M10 cells, though a trace amount of ladder formation was observed. Heat treatment of M10 cells induced apoptosis within 30 min after treatment, in contrast to MOLT-4N1 cells. The results suggest that apoptosis and necrosis are induced by X rays in a manner which is dependent on the cell line irrespective of the capability of the cells to develop apoptosis. DNA fragmentation was the earliest change observed in the development of apoptosis. 27 refs., 8 figs., 1 tab.

  15. Inhibition of PKR protects against tunicamycin-induced apoptosis in neuroblastoma cells.

    PubMed

    Vaughn, Lauren S; Snee, Brittany; Patel, Rekha C

    2014-02-15

    Endoplasmic reticulum (ER) dysfunction is thought to play a significant role in several neurological disorders, including Alzheimer's disease, Parkinson's disease, Huntington's disease, multiple sclerosis, amyotrophic lateral sclerosis, cerebral ischemia, and the prion diseases. ER dysfunction can be mimicked by cellular stress signals such as disruption of calcium homeostasis, inhibition of protein glycosylation, and reduction of disulfide bonds, which results in accumulation of misfolded proteins in the ER and leads to cell death by apoptosis. Tunicamycin, which is an inhibitor of protein glycosylation, induces ER stress and apoptosis. In this study, we examined the involvement of double stranded (ds) RNA-activated protein kinase PKR in tunicamycin-induced apoptosis. We used overexpression of the trans-dominant negative, catalytically inactive mutant K296R to inhibit PKR activity in neuroblastoma cells. We demonstrate that inhibition of PKR activation in response to tunicamycin protects neuronal cells from undergoing apoptosis. Furthermore, K296R overexpressing cells show defective PKR activation, delayed eIF2α phosphorylation, dramatically delayed ATF4 expression. In addition, both caspase-3 activation and C/EBP homologous protein (CHOP, also known as GADD153) induction, which are markers of apoptotic cells, are absent from K296R overexpression cells in response to tunicamycin. These results establish that PKR activation plays a major regulatory role in induction of apoptosis in response to ER stress and indicates the potential of PKR as possible target for neuroprotective therapeutics. PMID:24334130

  16. Short-chain fatty acid-initiated cell cycle arrest and apoptosis of colonic epithelial cells is linked to mitochondrial function.

    PubMed

    Heerdt, B G; Houston, M A; Augenlicht, L H

    1997-05-01

    Butyrate, a short-chain fatty acid produced during microbial fermentation of fiber, induces growth arrest, differentiation, and apoptosis of colonic epithelial cells in vitro, and our prior work has shown that this induction is tightly linked to mitochondrial activity. Here we demonstrate that 12 h following induction, SW620 human colonic carcinoma cells accumulate simultaneously in G0-G1 and G2-M of the cell cycle. Four h later, during this G0-G1 to G2-M arrest, cells begin to undergo apoptosis. Using a series of unrelated agents that modulate mitochondrial functions, we demonstrate that mitochondrial electron transport and membrane potential are critical in initiation of this butyrate-mediated growth arrest and apoptosis. Colonic tumorigenesis is characterized by abnormalities in proliferation, apoptosis, and mitochondrial activities. Thus, butyrate may reduce risk for colon cancer by inducing a pathway that enhances mitochondrial function, ultimately resulting in initiation of growth arrest and apoptosis of colonic epithelial cells. PMID:9149903

  17. Regulation of T cell apoptosis via T cell receptors and steroid receptors.

    PubMed

    Iwata, M; Ohoka, Y; Kuwata, T; Asada, A

    1996-11-01

    Less than 5% of immature CD4/CD8 double-positive (DP) thymocytes are positively selected to survive and differentiate into single-positive CD4 and CD8 T cells, while self-reactive DP thymocytes undergo apoptosis (negative selection). Both positive and negative selection events are active processes that involve signaling through the T cell receptors (TCRs) and through some accessory molecules. The two events differ quantitatively in the strength of the interaction between TCR and peptide/major histocompatibility complex molecules. We established an in vitro model of positive selection that can be analyzed quantitatively. Positive selection is likely to inhibit glucocorticoid-induced apoptosis in DP thymocytes. Proper crosslinking of TCR together with CD4, CD8, or LFA-1 inhibits the death, and its inhibitory activity is mimicked by proper combinations of ionomycin, a calcium ionophore, and phorbol myristate acetate (PMA), a protein kinase C (PKC) activator. The drug concentrations are within narrow ranges, and are lower than those which are required for the proliferation of mature T cells. Transient stimulation with the combinations of ionomycin and PMA induces differentiation and commitment of isolated DP thymocytes to the CD4 or CD8 T cell lineage in suspension cultures. The level of PKC activity appears to determine the lineage to commit. Functional mature T cells are induced from the committed cells upon secondary stimulation. Activation of calcineurin, a Ca2+/calmodulin-dependent protein phosphatase, also appears to be essential for positive selection as well as for the inhibition of glucocorticoid-induced apoptosis. Negative selection and the regulation of mature T cell apoptosis through TCR and steroid receptors are also discussed. PMID:8948021

  18. Select forms of tumor cell apoptosis induce dendritic cell maturation.

    PubMed

    Demaria, Sandra; Santori, Fabio R; Ng, Bruce; Liebes, Leonard; Formenti, Silvia C; Vukmanovic, Stanislav

    2005-03-01

    Dendritic cells (DC) play a crucial role in initiating immune responses to tumors. DC can efficiently present antigens from apoptotic tumor cells, but apoptotic cells are thought to lack the inflammatory signals required to induce DC maturation. Here, we show that apoptosis of 67NR mouse carcinoma cells via the Fas (CD95) pathway or induced by the anticancer drug bortezomib (PS-341) but not by ultraviolet irradiation is associated with the production of maturation signals for DC. These data have important implications for the effects of chemotherapy on antitumor immunity in solid and hematologic malignancies. PMID:15569694

  19. Apoptosis, oncosis, and necrosis. An overview of cell death.

    PubMed Central

    Majno, G.; Joris, I.

    1995-01-01

    The historical development of the cell death concept is reviewed, with special attention to the origin of the terms necrosis, coagulation necrosis, autolysis, physiological cell death, programmed cell death, chromatolysis (the first name of apoptosis in 1914), karyorhexis, karyolysis, and cell suicide, of which there are three forms: by lysosomes, by free radicals, and by a genetic mechanism (apoptosis). Some of the typical features of apoptosis are discussed, such as budding (as opposed to blebbing and zeiosis) and the inflammatory response. For cell death not by apoptosis the most satisfactory term is accidental cell death. Necrosis is commonly used but it is not appropriate, because it does not indicate a form of cell death but refers to changes secondary to cell death by any mechanism, including apoptosis. Abundant data are available on one form of accidental cell death, namely ischemic cell death, which can be considered an entity of its own, caused by failure of the ionic pumps of the plasma membrane. Because ischemic cell death (in known models) is accompanied by swelling, the name oncosis is proposed for this condition. The term oncosis (derived from ónkos, meaning swelling) was proposed in 1910 by von Reckling-hausen precisely to mean cell death with swelling. Oncosis leads to necrosis with karyolysis and stands in contrast to apoptosis, which leads to necrosis with karyorhexis and cell shrinkage. Images Figure 1 Figure 2 Figure 3 Figure 5 Figure 6 Figure 7 Figure 8 PMID:7856735

  20. Nonautonomous Apoptosis Is Triggered by Local Cell Cycle Progression during Epithelial Replacement in Drosophila ▿ †

    PubMed Central

    Nakajima, Yu-ichiro; Kuranaga, Erina; Sugimura, Kaoru; Miyawaki, Atsushi; Miura, Masayuki

    2011-01-01

    Tissue remodeling involves collective cell movement, and cell proliferation and apoptosis are observed in both development and disease. Apoptosis and proliferation are considered to be closely correlated, but little is known about their coordinated regulation in physiological tissue remodeling in vivo. The replacement of larval abdominal epidermis with adult epithelium in Drosophila pupae is a simple model of tissue remodeling. During this process, larval epidermal cells (LECs) undergo apoptosis and are replaced by histoblasts, which are adult precursor cells. By analyzing caspase activation at the single-cell level in living pupae, we found that caspase activation in LECs is induced at the LEC/histoblast boundary, which expands as the LECs die. Manipulating histoblast proliferation at the LEC/histoblast boundary, either genetically or by UV illumination, indicated that local interactions with proliferating histoblasts triggered caspase activation in the boundary LECs. Finally, by monitoring the spatiotemporal dynamics of the S/G2/M phase in histoblasts in vivo, we found that the transition from S/G2 phases is necessary to induce nonautonomous LEC apoptosis at the LEC/histoblast boundary. The replacement boundary, formed as caspase activation is regulated locally by cell-cell communication, may drive the dynamic orchestration of cell replacement during tissue remodeling. PMID:21482673

  1. NLRP3 regulates a non-canonical platform for caspase-8 activation during epithelial cell apoptosis.

    PubMed

    Chung, H; Vilaysane, A; Lau, A; Stahl, M; Morampudi, V; Bondzi-Simpson, A; Platnich, J M; Bracey, N A; French, M-C; Beck, P L; Chun, J; Vallance, B A; Muruve, D A

    2016-08-01

    Nod-like receptor, pyrin containing 3 (NLRP3) is characterized primarily as a canonical caspase-1 activating inflammasome in macrophages. NLRP3 is also expressed in the epithelium of the kidney and gut; however, its function remains largely undefined. Primary mouse tubular epithelial cells (TEC) lacking Nlrp3 displayed reduced apoptosis downstream of the tumor necrosis factor (TNF) receptor and CD95. TECs were identified as type II apoptotic cells that activated caspase-8, tBid and mitochondrial apoptosis via caspase-9, responses that were reduced in Nlrp3-/- cells. The activation of caspase-8 during extrinsic apoptosis induced by TNFα/cycloheximide (TNFα/CHX) was dependent on adaptor protein apoptosis-associated speck-like protein containing a CARD (ASC) and completely independent of caspase-1 or caspase-11. TECs and primary human proximal tubular epithelial cells (HPTC) did not activate a canonical inflammasome, caspase-1, or IL-1β secretion in response to TNFα/CHX or NLRP3-dependent triggers, such as ATP or nigericin. In cell fractionation studies and by confocal microscopy, NLRP3 colocalized with ASC and caspase-8 in speck-like complexes at the mitochondria during apoptosis. The formation of NLRP3/ASC/caspase-8 specks in response to TNFα/CHX was downstream of TNFR signaling and dependent on potassium efflux. Epithelial ASC specks were present in enteroids undergoing apoptosis and in the injured tubules of wild-type but not Nlrp3-/- or ASC-/- mice following ureteric unilateral obstruction in vivo. These data show that NLRP3 and ASC form a conserved non-canonical platform for caspase-8 activation, independent of the inflammasome that regulates apoptosis within epithelial cells. PMID:26891693

  2. Morphological and cytochemical determination of cell death by apoptosis

    PubMed Central

    Sobel, Burton E.; Budd, Ralph C.

    2007-01-01

    Several modes of cell death are now recognized, including necrosis, apoptosis, and autophagy. Oftentimes the distinctions between these various modes may not be apparent, although the precise mode may be physiologically important. Accordingly, it is often desirable to be able to classify the mode of cell death. Apoptosis was originally defined by structural alterations in cells observable by transmitted light and electron microscopy. Today, a wide variety of imaging and cytochemical techniques are available for the investigation of apoptosis. This review will highlight many of these methods, and provide a critique on the advantages and disadvantages associated with them for the specific identification of apoptotic cells in culture and tissues. PMID:18000678

  3. T-Cell Apoptosis in Inflammatory Brain Lesions

    PubMed Central

    Bauer, Jan; Bradl, Monika; Hickey, William F.; Forss-Petter, Sonja; Breitschopf, Helene; Linington, Chris; Wekerle, Hartmut; Lassmann, Hans

    1998-01-01

    Elimination of inflammatory T cells by apoptosis appears to play an important role in the down-regulation of inflammation in the central nervous system. Here we report that apoptosis of T lymphocytes occurs to a similar extent in different models of autoimmune encephalomyelitis. Apoptosis is restricted to cells located in the neuroectodermal parenchyma, thereby leaving T cells present in the brain’s connective tissue compartments unharmed. Death of T cells in the parenchyma does not depend on antigen presentation by resident microglial cells or astrocytes. Adoptive transfer experiments with T lymphocytes carrying a specific genetic marker revealed that in the central nervous system these cells are destroyed regardless of their antigen specificity or state of activation. Although many of both antigen-dependent and -independent mechanisms in the induction of T-cell apoptosis may act simultaneously, our results suggest that the nervous system harbors a specific, currently undefined, mechanism that effectively eliminates infiltrating T lymphocytes. PMID:9736022

  4. [Cell shrinkage during apoptosis is not obligatory. Apoptosis of U937 cells induced by staurosporine and etoposide].

    PubMed

    Vereninov, A A; Goriachaia, T S; Matveev, V V; Moshkov, A V; Rozanov, Iu M; Sakuta, G A; Shirokova, A V; Iurinskaia, V E

    2004-01-01

    A study was made of apoptotic cell shrinkage, which is generally believed to be a hallmark of apoptosis. The two conventional models of apoptosis were used for examination of changes in cell water balance--one is apoptosis caused in human lymphoma cell line U937 by staurosporine, and the other by etoposide. Intracellular water was determined by measuring buoyant density of cells in continuous Percoll gradient. Apoptosis was recognized by microscopy and flow cytometry. Apoptosis caused by staurosporine (1 microM, 4 h) was found to be associated with a decrease in cell water content by almost 24%. In contrast, no decrease in cell water content was observed in U937 cells incubated with etoposide (50 microM, 4 h), in spite of the number of features suggesting the presence of apoptosis, such as the appearance of apoptotic bodies, chromatin condensation and fragmentation and disappearance of S-phase cells in DNA histogram. It is concluded that definition of apoptosis as "shrinkage-necrosis" (Kerr, 1971) needs correcting: the distinction of apoptotic cells involves the absence of swelling, rather than cell shrinkage. PMID:15473371

  5. Responses of insect cells to baculovirus infection: protein synthesis shutdown and apoptosis.

    PubMed Central

    Du, X; Thiem, S M

    1997-01-01

    Protein synthesis is globally shut down at late times postinfection in the baculovirus Autographa californica M nuclear polyhedrosis virus (AcMNPV)-infected gypsy moth cell line Ld652Y. A single gene, hrf-1, from another baculovirus, Lymantria dispar M nucleopolyhedrovirus, is able to preclude protein synthesis shutdown and ensure production of AcMNPV progeny in Ld652Y cells (S. M. Thiem, X. Du, M. E. Quentin, and M. M. Berner, J. Virol. 70:2221-2229, 1996; X. Du and S. M. Thiem, Virology 227:420-430, 1997). AcMNPV contains a potent antiapoptotic gene, p35, and protein synthesis arrest was reported in apoptotic insect cells induced by infection with AcMNPV lacking p35. In exploring the function of host range factor 1 (HRF-1) and the possible connection between protein synthesis shutdown and apoptosis, a series of recombinant AcMNPVs with different complements of p35 and hrf-1 were employed in apoptosis and protein synthesis assays. We found that the apoptotic suppressor AcMNPV P35 was translated prior to protein synthesis shutdown and functioned to prevent apoptosis. HRF-1 prevented protein synthesis shutdown even when the cells were undergoing apoptosis, but HRF-1 could not functionally substitute for P35. The DNA synthesis inhibitor aphidicolin could block both apoptosis and protein synthesis shutdown in Ld652Y cells infected with p35 mutant AcMNPVs but not the protein synthesis shutdown in wild-type AcMNPV-infected Ld652Y cells. These data suggest that protein synthesis shutdown and apoptosis are separate responses of Ld652Y cells to AcMNPV infection and that P35 is involved in inducing a protein synthesis shutdown response in the absence of late viral gene expression in Ld652Y cells. A model was developed for these responses of Ld652Y cells to AcMNPV infection. PMID:9311875

  6. Induction of apoptosis in frog virus 3-infected cells.

    PubMed

    Chinchar, V G; Bryan, Locke; Wang, J; Long, Scott; Chinchar, G D

    2003-02-15

    The ability of frog virus 3 (FV3), the type species of the family Iridoviridae, to induce apoptosis was examined by monitoring DNA cleavage, chromatin condensation, and cell-surface expression of phosphotidylserine (PS) in fathead minnow (FHM) and baby hamster kidney (BHK) cells. In productively infected FHM cells, DNA fragmentation was first noted at 6-7 h postinfection and was clearly seen by 17 h postinfection, while chromatin condensation was detected at 8.5 h postinfection. As with some other viruses, FV3-induced apoptosis did not require de novo viral gene expression as both heat-inactivated and UV-inactivated virus readily triggered DNA fragmentation in FHM cells. Moreover, FV3-induced apoptosis was blocked in FHM cells by the pan-caspase inhibitor Z-VAD-FMK, suggesting that virus infection triggers programmed cell death through activation of the caspase cascade. FV3 infection also triggered apoptosis in BHK cells as monitored by TUNEL and annexin V binding assays. To determine whether FV3, similar to other large DNA viruses, encoded proteins that block or delay apoptosis, mock- and FV3-infected FHM cells were osmotically shocked and assayed for DNA fragmentation 3 hours later. DNA fragmentation was clearly seen whether or not shocked cells were previously infected with FV3, indicating that infection with FV3 did not block apoptosis induced by osmotic shock in FHM cells. The above results demonstrate that iridoviruses triggered apoptosis and that the induction of programmed cell death did not require viral gene expression. However, it remains to be determined if virion attachment to target cells is sufficient to induce cell death, or if apoptosis is triggered directly or indirectly by one or more virion-associated proteins. PMID:12642103

  7. Characterization of radiation-induced Apoptosis in rodent cell lines

    SciTech Connect

    Guo, Min; Chen, Changhu; Ling, C.C.

    1997-03-01

    For REC:myc(ch1), Rat1 and Rat1:myc{sub b} cells, we determined the events in the development of radiation-induced apoptosis to be in the following order: cell division followed by chromatin condensation, membrane blebbing, loss of adhesion and the uptake of vital dye. Experimental data which were obtained using {sup 4}He ions of well defined energies and which compared the dependence of apoptosis and clonogenic survival on {sup 4}He range strongly suggested that in our cells both apoptosis and loss of clonogenic survival resulted from radiation damage to the cell nucleus. Corroboratory evidence was that BrdU incorporation sensitized these cells to radiation-induced apoptosis. Comparing the dose response for apoptosis and the clonogenic survival curves for Rat1 and Rat1:myc{sub b} cells, we concluded that radiation-induced cell inactivation as assayed by clonogenic survival, and that a modified linear-quadratic model, proposed previously, modeled such a contribution effectively. In the same context, the selective increase in radiation-induced apoptosis. Comparing the dose response for apoptosis and the clonogenic survival curves for Rat1 and Rat1:myc{sub b} cells, we concluded that radiation-induced apoptosis contributed to the overall radiation-induced cell inactivation as assayed by clonogenic survival, and that a modified linear-quadratic model, proposed previously, modeled such a contribution effectively. In the same context, the selective increase in radiation-induced apoptosis during late S and G{sub 2} phases reduced the relative radioresistance observed for clonogenic survival during late S and G{sub 2} phases. 30 refs., 8 figs.

  8. Apoptosis in vascular cells induced by cold atmospheric plasma treatment

    NASA Astrophysics Data System (ADS)

    Sladek, Raymond; Stoffels, Eva

    2006-10-01

    Apoptosis is a natural mechanism of cellular self-destruction. It can be triggered by moderate, yet irreversible damage. Apoptosis plays a major role in tissue renewal. Artificial apoptosis induction will become a novel therapy that meets all requirements for tissue-saving surgery. Diseased tissues can disappear without inflammation and scarring. This is particularly important in treatment of blockages in body tracts (e.g. cardiovascular diseases). Artificial induction of apoptosis can be achieved by means of cold plasma treatment. In this work an atmospheric micro-plasma operated in helium/air has been used to induce apoptosis in vascular cells. Parametric studies of apoptosis induction have been conducted; the efficiency is almost 100%. The apoptotic factors are ROS/RNS (reactive oxygen and nitrogen species). Their densities in the plasma have been measured by mass spectrometry. For apoptosis induction, RNS seem to be more important than ROS, because of their relative abundance. Moreover, addition of a ROS scavenger (ascorbic acid) to the cell culture medium does not reduce the occurrence of apoptosis. Cold plasma is a very efficient tool for fundamental studies of apoptosis, and later, for controlled tissue removal in vivo.

  9. Apoptosis signal-regulating kinase 1 mediates denbinobin-induced apoptosis in human lung adenocarcinoma cells

    PubMed Central

    Kuo, Chen-Tzu; Chen, Bing-Chang; Yu, Chung-Chi; Weng, Chih-Ming; Hsu, Ming-Jen; Chen, Chien-Chih; Chen, Mei-Chieh; Teng, Che-Ming; Pan, Shiow-Lin; Bien, Mauo-Ying; Shih, Chung-Hung; Lin, Chien-Huang

    2009-01-01

    In the present study, we explore the role of apoptosis signal-regulating kinase 1 (ASK1) in denbinobin-induced apoptosis in human lung adenocarcinoma (A549) cells. Denbinobin-induced cell apoptosis was attenuated by an ASK1 dominant-negative mutant (ASK1DN), two antioxidants (N-acetyl-L-cysteine (NAC) and glutathione (GSH)), a c-Jun N-terminal kinase (JNK) inhibitor (SP600125), and an activator protein-1 (AP-1) inhibitor (curcumin). Treatment of A549 cells with denbinobin caused increases in ASK1 activity and reactive oxygen species (ROS) production, and these effects were inhibited by NAC and GSH. Stimulation of A549 cells with denbinobin caused JNK activation; this effect was markedly inhibited by NAC, GSH, and ASK1DN. Denbinobin induced c-Jun phosphorylation, the formation of an AP-1-specific DNA-protein complex, and Bim expression. Bim knockdown using a bim short interfering RNA strategy also reduced denbinobin-induced A549 cell apoptosis. The denbinobin-mediated increases in c-Jun phosphorylation and Bim expression were inhibited by NAC, GSH, SP600125, ASK1DN, JNK1DN, and JNK2DN. These results suggest that denbinobin might activate ASK1 through ROS production to cause JNK/AP-1 activation, which in turn induces Bim expression, and ultimately results in A549 cell apoptosis. PMID:19405983

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

    PubMed Central

    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-apoptosis

  11. Intracellular Staphylococcus aureus Escapes the Endosome and Induces Apoptosis in Epithelial Cells

    PubMed Central

    Bayles, Kenneth W.; Wesson, Carla A.; Liou, Linda E.; Fox, Lawrence K.; Bohach, Gregory A.; Trumble, W. R.

    1998-01-01

    We examined the invasion of an established bovine mammary epithelial cell line (MAC-T) by a Staphylococcus aureus mastitis isolate to study the potential role of intracellular survival in the persistence of staphylococcal infections. S. aureus cells displayed dose-dependent invasion of MAC-T cells and intracellular survival. An electron microscopic examination of infected cells indicated that the bacteria induced internalization via a mechanism involving membrane pseudopod formation and then escaped into the cytoplasm following lysis of the endosomal membrane. Two hours after the internalization of S. aureus, MAC-T cells exhibited detachment from the matrix, rounding, a mottled cell membrane, and vacuolization of the cytoplasm, all of which are indicative of cells undergoing programmed cell death (apoptosis). By 18 h, the majority of the MAC-T cell population exhibited an apoptotic morphology. Other evidence for apoptosis was the generation of MAC-T cell DNA fragments differing in size by increments of approximately 180 bp and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling of the fragmented nuclear DNA of the infected host cells. These results demonstrate that after internalization S. aureus escapes the endosome and induces apoptosis in nonprofessional phagocytes. PMID:9423876

  12. A novel histone deacetylase inhibitor Chidamide induces apoptosis of human colon cancer cells

    SciTech Connect

    Liu, Lin; Chen, Baoan; Qin, Shukui; Li, Suyi; He, Xiangming; Qiu, Shaomin; Zhao, Wei; Zhao, Hong

    2010-02-05

    Many studies have demonstrated that histone deacetylase (HDAC) inhibitors induce various tumor cells to undergo apoptosis, and such inhibitors have been used in different clinical trials against different human cancers. In this study, we designed and synthesized a novel HDAC inhibitor, Chidamide. We showed that Chidamide was able to increase the acetylation levels of histone H3 and to inhibit the PI3K/Akt and MAPK/Ras signaling pathways, which resulted in arresting colon cancer cells at the G1 phase of the cell cycle and promoting apoptosis. As a result, the proliferation of colon cancer cells was suppressed in vitro. Our data support the potential application of Chidamide as an anticancer agent in treating colon cancer. Future studies are needed to demonstrate its in vivo efficacy.

  13. Inhibition of apoptosis in human immunodeficiency virus-infected cells enhances virus production and facilitates persistent infection.

    PubMed Central

    Antoni, B A; Sabbatini, P; Rabson, A B; White, E

    1995-01-01

    Apoptosis is one of several mechanisms by which human immunodeficiency virus type 1 (HIV-1) exerts its cytopathic effects. CD4+ Jurkat T-cell lines overexpressing the adenovirus E1B 19K protein, a potent inhibitor of apoptosis, were used to examine the consequences of inhibition of apoptosis during acute and chronic HIV-1 infections. E1B 19K protein expression inhibited HIV-induced apoptosis, enhanced virus production, and established high levels of persistent viral infection. One E1B 19K-expressing line appeared to undergo HIV-induced death via a nonapoptotic mechanism, illustrating that HIV infection results in lymphocyte depletion through multiple pathways. Increased virus production associated with sustained cell viability suggests that therapeutic approaches involving inhibition of HIV-induced programmed cell death may be problematic. PMID:7884884

  14. Triggering Apoptosis in Hematopoietic Cells with Cytotoxic Drugs.

    PubMed

    Crowley, Lisa C; Marfell, Brooke J; Scott, Adrian P; Waterhouse, Nigel J

    2016-01-01

    Cytotoxic agents are commonly added to cultured cells in the laboratory to investigate their efficacy, mechanism of action, and therapeutic potential. Most of these agents trigger cell death by apoptosis, which is also the most common form of cell death during development, aging, homeostasis, and eradication of disease. Treatment of cells with cytotoxic agents is therefore useful for investigating basic mechanisms of cell death in the human body. Actinomycin D, a cytotoxic agent isolated from Streptomyces, induces apoptosis in a variety of cell lines including the histiocytic lymphoma cell line U937. Treatment of U937 cells with actinomycin D provides an ideal model of drug-induced apoptosis that can also be used as a positive control for comparison with other treatments. PMID:27371592

  15. Mutations in ribosomal proteins: Apoptosis, cell competition, and cancer.

    PubMed

    Baker, Nicholas E; Kale, Abhijit

    2016-01-01

    Mutations affecting multiple ribosomal proteins are implicated in cancer. Using genetic mosaics in the fruit fly Drosophila, we describe 3 apoptotic mechanisms that affect Rp/Rp homozygous mutant cells, Rp/+ heterozygous cells, or Rp/+ heterozygous cells in competition with nearby wild type cells, and discuss how apoptosis might be related to cancer predisposition. PMID:27308545

  16. Mutations in ribosomal proteins: Apoptosis, cell competition, and cancer

    PubMed Central

    Baker, Nicholas E.; Kale, Abhijit

    2016-01-01

    Mutations affecting multiple ribosomal proteins are implicated in cancer. Using genetic mosaics in the fruit fly Drosophila, we describe 3 apoptotic mechanisms that affect Rp/Rp homozygous mutant cells, Rp/+ heterozygous cells, or Rp/+ heterozygous cells in competition with nearby wild type cells, and discuss how apoptosis might be related to cancer predisposition. PMID:27308545

  17. Cathepsin B Activity Initiates Apoptosis via Digestive Protease Activation in Pancreatic Acinar Cells and Experimental Pancreatitis.

    PubMed

    Sendler, Matthias; Maertin, Sandrina; John, Daniel; Persike, Maria; Weiss, F Ulrich; Krüger, Burkhard; Wartmann, Thomas; Wagh, Preshit; Halangk, Walter; Schaschke, Norbert; Mayerle, Julia; Lerch, Markus M

    2016-07-01

    Pancreatitis is associated with premature activation of digestive proteases in the pancreas. The lysosomal hydrolase cathepsin B (CTSB) is a known activator of trypsinogen, and its deletion reduces disease severity in experimental pancreatitis. Here we studied the activation mechanism and subcellular compartment in which CTSB regulates protease activation and cellular injury. Cholecystokinin (CCK) increased the activity of CTSB, cathepsin L, trypsin, chymotrypsin, and caspase 3 in vivo and in vitro and induced redistribution of CTSB to a secretory vesicle-enriched fraction. Neither CTSB protein nor activity redistributed to the cytosol, where the CTSB inhibitors cystatin-B/C were abundantly present. Deletion of CTSB reduced and deletion of cathepsin L increased intracellular trypsin activation. CTSB deletion also abolished CCK-induced caspase 3 activation, apoptosis-inducing factor, as well as X-linked inhibitor of apoptosis protein degradation, but these depended on trypsinogen activation via CTSB. Raising the vesicular pH, but not trypsin inhibition, reduced CTSB activity. Trypsin inhibition did not affect apoptosis in hepatocytes. Deletion of CTSB affected apoptotic but not necrotic acinar cell death. In summary, CTSB in pancreatitis undergoes activation in a secretory, vesicular, and acidic compartment where it activates trypsinogen. Its deletion or inhibition regulates acinar cell apoptosis but not necrosis in two models of pancreatitis. Caspase 3-mediated apoptosis depends on intravesicular trypsinogen activation induced by CTSB, not CTSB activity directly, and this mechanism is pancreas-specific. PMID:27226576

  18. The vitronectin RGD motif regulates TGF-β-induced alveolar epithelial cell apoptosis.

    PubMed

    Wheaton, Amanda K; Velikoff, Miranda; Agarwal, Manisha; Loo, Tiffany T; Horowitz, Jeffrey C; Sisson, Thomas H; Kim, Kevin K

    2016-06-01

    Transforming growth factor-β (TGF-β) is a critical driver of acute lung injury and fibrosis. Injury leads to activation of TGF-β, which regulates changes in the cellular and matrix makeup of the lung during the repair and fibrosis phase. TGF-β can also initiate alveolar epithelial cell (AEC) apoptosis. Injury leads to destruction of the laminin-rich basement membrane, which is replaced by a provisional matrix composed of arginine-glycine-aspartate (RGD) motif-containing plasma matrix proteins, including vitronectin and fibronectin. To determine the role of specific matrix proteins on TGF-β-induced apoptosis, we studied primary AECs cultured on different matrix conditions and utilized mice with deletion of vitronectin (Vtn(-/-)) or mice in which the vitronectin RGD motif is mutated to nonintegrin-binding arginine-glycine-glutamate (RGE) (Vtn(RGE/RGE)). We found that AECs cultured on fibronectin and vitronectin or in wild-type mouse serum are resistant to TGF-β-induced apoptosis. In contrast, AECs cultured on laminin or in serum from Vtn(-/-) or Vtn(RGE/RGE) mice undergo robust TGF-β-induced apoptosis. Plasminogen activator inhibitor-1 (PAI-1) sensitizes AECs to greater apoptosis by disrupting AEC engagement to vitronectin. Inhibition of integrin-associated signaling proteins augments AEC apoptosis. Mice with transgenic deletion of PAI-1 have less apoptosis after bleomycin, but deletion of vitronectin or disruption of the vitronectin RGD motif reverses this protection, suggesting that the proapoptotic function of PAI-1 is mediated through vitronectin inhibition. Collectively, these data suggest that integrin-matrix signaling is an important regulator of TGF-β-mediated AEC apoptosis and that PAI-1 functions as a natural regulator of this interaction. PMID:27106291

  19. Interleukin-24 mediates apoptosis in human B-cells through early activation of cell cycle arrest followed by late induction of the mitochondrial apoptosis pathway.

    PubMed

    Hadife, Nader; Nemos, Christophe; Frippiat, Jean-Pol; Hamadé, Tala; Perrot, Aurore; Dalloul, Ali

    2013-03-01

    Interleukin (IL)-24 has death-promoting effects on various proliferating cells including B-cells from chronic lymphocytic leukemia (CLL) and germinal center B-cells, but its molecular mechanisms are poorly understood. Using a B-cell differentiation model and mRNA profiling, we found that recombinant (r)IL-24 stimulated genes of the mitochondrial apoptotic pathway (Bax, Bid, Casp8, COX6C, COX7B) after 36 h, whereas the transcription of genes involved in DNA replication and metabolism was inhibited within 6 h. Unexpectedly, insulin-like growth factor 1 (IGF1), a hormone known to promote cell growth, was stimulated by IL-24. Activated B-cells express receptor for IGF1, to which they become sensitized and undergo apoptosis, a mechanism similar in this respect to IL-24-induced cell death. Furthermore, inhibition of the IGF1 pathway reversed the effects of IL-24. IL-24-mediated apoptosis was also antagonized by pifithrin-alpha, an inhibitor of p53 transactivation. Altogether, these results disclose sequential molecular signals generated by IL-24 in activated B-cells. PMID:22860893

  20. Apaf1 inhibition promotes cell recovery from apoptosis.

    PubMed

    Gortat, Anna; Sancho, Mónica; Mondragón, Laura; Messeguer, Àngel; Pérez-Payá, Enrique; Orzáez, Mar

    2015-11-01

    The protein apoptotic protease activating factor 1 (Apaf1) is the central component of the apoptosome, a multiprotein complex that activates procaspase-9 after cytochrome c release from the mitochondria in the intrinsic pathway of apoptosis. We have developed a vital method that allows fluorescence-activated cell sorting of cells at different stages of the apoptotic pathway and demonstrated that upon pharmacological inhibition of Apaf1, cells recover from doxorubicin- or hypoxia-induced early apoptosis to normal healthy cell. Inhibiting Apaf1 not only prevents procaspase-9 activation but delays massive mitochondrial damage allowing cell recovery. PMID:26361785

  1. Dendrosomal curcumin nanoformulation modulate apoptosis-related genes and protein expression in hepatocarcinoma cell lines.

    PubMed

    Montazeri, Maryam; Sadeghizadeh, Majid; Pilehvar-Soltanahmadi, Yones; Zarghami, Faraz; Khodi, Samaneh; Mohaghegh, Mina; Sadeghzadeh, Hadi; Zarghami, Nosratollah

    2016-07-25

    The side-effects observed in conventional therapies have made them unpromising in curing Hepatocellular carcinoma; therefore, developing novel treatments can be an overwhelming significance. One of such novel agents is curcumin which can induce apoptosis in various cancerous cells, however, its poor solubility is restricted its application. To overcome this issue, this paper employed dendrosomal curcumin (DNC) was employed to in prevent hepatocarcinoma in both RNA and protein levels. Hepatocarcinoma cells, p53 wild-type HepG2 and p53 mutant Huh7, were treated with DNC and investigated for toxicity study using MTT assay. Cell cycle distribution and apoptosis were analyzed using Flow-cytometry and Annexin-V-FLUOS/PI staining. Real-time PCR and Western blot were employed to analyze p53, BAX, Bcl-2, p21 and Noxa in DNC-treated cells. DNC inhibited the growth in the form of time-dependent manner, while the carrier alone was not toxic to the cell. Flow-cytometry data showed the constant concentration of 20μM DNC during the time significantly increases cell population in SubG1 phase. Annexin-V-PI test showed curcumin-induced apoptosis was enhanced in Huh7 as well as HepG2, compared to untreated cells. Followed by treatment, mRNA expression of p21, BAX, and Noxa increased, while the expression of Bcl-2 decreased, and unlike HepG2, Huh7 showed down-regulation of p53. In summary, DNC-treated hepatocellular carcinoma cells undergo apoptosis by changing the expression of genes involved in the apoptosis and proliferation processes. These findings suggest that DNC, as a plant-originated therapeutic agent, could be applied in cancer treatment. PMID:27234697

  2. HIV/SIV Infection Primes Monocytes and Dendritic Cells for Apoptosis

    PubMed Central

    Monceaux, Valérie; Cumont, Marie-Christine; Hurtrel, Bruno; Corbeil, Jacques; Zaunders, John

    2011-01-01

    Subversion or exacerbation of antigen-presenting cells (APC) death modulates host/pathogen equilibrium. We demonstrated during in vitro differentiation of monocyte-derived macrophages and monocyte-derived dendritic cells (DCs) that HIV sensitizes the cells to undergo apoptosis in response to TRAIL and FasL, respectively. In addition, we found that HIV-1 increased the levels of pro-apoptotic Bax and Bak molecules and decreased the levels of anti-apoptotic Mcl-1 and FLIP proteins. To assess the relevance of these observations in the context of an experimental model of HIV infection, we investigated the death of APC during pathogenic SIV-infection in rhesus macaques (RMs). We demonstrated increased apoptosis, during the acute phase, of both peripheral blood DCs and monocytes (CD14+) from SIV+RMs, associated with a dysregulation in the balance of pro- and anti-apoptotic molecules. Caspase-inhibitor and death receptors antagonists prevented apoptosis of APCs from SIV+RMs. Furthermore, increased levels of FasL in the sera of pathogenic SIV+RMs were detected, compared to non-pathogenic SIV infection of African green monkey. We suggest that inappropriate apoptosis of antigen-presenting cells may contribute to dysregulation of cellular immunity early in the process of HIV/SIV infection. PMID:21731488

  3. Evaluation of apoptosis induction in human peripheral blood mononuclear cells and synovial cells in patients with rheumatoid arthritis.

    PubMed

    Demian, Soheir R; Abo-Shousha, Seham A; Sultan, Hussein E; Zarka, Wael El

    2005-01-01

    Rheumatoid arthritis (RA) is a chronic inflammatory destructive disease involving the joint and characterized by T-lymphocyte accumulation within the synovial compartment. It is dominated by the presence of macrophages, plasma cells and synovial fibroblasts which are the main pathogenic factors leading to the destruction of bone and cartilage. The survival of these cells may be promoted by inadequate apoptosis leading to synovial hyperplasia. So, the aim of the present study was to evaluate the apoptosis levels before and after induction of apoptosis using anti-Fas mAb, both in peripheral blood (PB) and synovial fluid (SF) infiltrating mononuclear cells (MCs) of patients with RA. CD4+ T cell subsets and cell survival assays were also done to investigate correlations between these parameters. The study was conducted on 15 patients with RA, 10 individual volunteers as a control group and 10 patients with osteoarthritis (OA) as a control group for SF evaluations (have defective Fas expression on their cells). Results of this work revealed that in vitro induction of apoptosis by anti-Fas mAb resulted in increase of: percent (%) reduction of cell viability in PBMCs and SFMCs, % reduction of CD4+ T cell subsets and apoptotic cell % in all studied groups than before induction. The increase in the three parameters is only significant in SF of RA group compared to PB while it is non significant in OA group due to the defective Fas expression on OA cells. Our results also showed a significant positive correlation between CD4+ T cell and viability percentages before induction of apoptosis in SF of RA and between apoptosis levels and CD4+ T cell percentage after induction of apoptosis in the SF of RA group. In conclusion, activated T cells infiltrating SF of RA patients have functional Fas antigen which enable them to undergo in vitro apoptosis using anti-Fas mAb. The cytotoxicity of which is more specific to local lesion such as SF of RA patients suggesting that local

  4. Apoptosis transcriptional mechanism of feline infectious peritonitis virus infected cells.

    PubMed

    Shuid, Ahmad Naqib; Safi, Nikoo; Haghani, Amin; Mehrbod, Parvaneh; Haron, Mohd Syamsul Reza; Tan, Sheau Wei; Omar, Abdul Rahman

    2015-11-01

    Apoptosis has been postulated to play an important role during feline infectious peritonitis virus (FIPV) infection; however, its mechanism is not well characterized. This study is focused on apoptosis and transcriptional profiling of FIPV-infected cells following in vitro infection of CRFK cells with FIPV 79-1146 WSU. Flow cytometry was used to determine mode of cell death in first 42 h post infection (hpi). FIPV infected cells underwent early apoptosis at 9 hpi (p < 0.05) followed by late apoptosis at 12 hpi (p < 0.05) and necrosis from 24 hpi (p < 0.05). Then, next generation sequencing was performed on 9 hpi and control uninfected cells by Illumina analyzer. An aggregate of 4546 genes (2229 down-regulated and 2317 up-regulated) from 17 cellular process, 11 molecular functions and 130 possible biological pathways were affected by FIPV. 131 genes from apoptosis cluster (80 down-regulated and 51 up-regulated) along with increase of apoptosis, p53, p38 MAPK, VEGF and chemokines/cytokines signaling pathways were probably involved in apoptosis process. Six of the de-regulated genes expression (RASSF1, BATF2, MAGEB16, PDCD5, TNFα and TRAF2) and TNFα protein concentration were analyzed by RT-qPCR and ELISA, respectively, at different time-points. Up-regulations of both pro-apoptotic (i.e. PDCD5) and anti-apoptotic (i.e. TRAF2) were detected from first hpi and continuing to deregulate during apoptosis process in the infected cells. PMID:26386572

  5. Autophagy Regulates Colistin-Induced Apoptosis in PC-12 Cells

    PubMed Central

    Zhang, Ling; Zhao, Yonghao; Ding, Wenjian; Jiang, Guozheng; Lu, Ziyin; Li, Li; Wang, Jinli

    2015-01-01

    Colistin is a cyclic cationic polypeptide antibiotic with activity against multidrug-resistant Gram-negative bacteria. Our recent study demonstrated that colistin induces apoptosis in primary chick cortex neurons and PC-12 cells. Although apoptosis and autophagy have different impacts on cell fate, there is a complex interaction between them. Autophagy plays an important role as a homeostasis regulator by removing excessive or unnecessary proteins and damaged organelles. The aim of the present study was to investigate the modulation of autophagy and apoptosis regulation in PC-12 cells in response to colistin treatment. PC-12 cells were exposed to colistin (125 to 250 μg/ml), and autophagy was detected by visualization of monodansylcadaverine (MDC)-labeled vacuoles, LC3 (microtubule-associated protein 1 light chain 3) immunofluorescence microscopic examination, and Western blotting. Apoptosis was measured by flow cytometry, Hoechst 33258 staining, and Western blotting. Autophagosomes were observed after treatment with colistin for 12 h, and the levels of LC3-II gene expression were determined; observation and protein levels both indicated that colistin induced a high level of autophagy. Colistin treatment also led to apoptosis in PC-12 cells, and the level of caspase-3 expression increased over the 24-h period. Pretreatment of cells with 3-methyladenine (3-MA) increased colistin toxicity in PC-12 cells remarkably. However, rapamycin treatment significantly increased the expression levels of LC3-II and beclin 1 and decreased the rate of apoptosis of PC-12 cells. Our results demonstrate that colistin induced autophagy and apoptosis in PC-12 cells and that the latter was affected by the regulation of autophagy. It is very likely that autophagy plays a protective role in the reduction of colistin-induced cytotoxicity in neurons. PMID:25645826

  6. Effect of storage media on human periodontal ligament cell apoptosis.

    PubMed

    Chamorro, Mónica M; Regan, John D; Opperman, Lynne A; Kramer, Phillip R

    2008-02-01

    The ability of storage media to preserve periodontal ligament (PDL) cell vitality has been previously evaluated. However, the mechanisms by which different storage conditions alter the functional status of PDL cells have not been determined. The purpose of the present study was to investigate, in vitro, the level of programed cell death or apoptosis in a population of PDL cells following storage under different conditions. Primary human PDL cells were plated into 24-well-culture plates and allowed to attach for 24 h. Cells were then exposed for 1 h to milk, Hank's balanced salt solution (HBSS), Soft Wear contact lens solution or Gatorade at room temperature or on ice. Culture medium was used as a negative control. Apoptosis was evaluated at 24, 48, and 72 h after treatment on quadruplicate samples by using the ST 160 ApopTag Fluorescein Direct In Situ Detection Kit. The total number of cells and the total number of apoptotic cells were counted. The results indicated that at 24 and 72 h, PDL treated with Gatorade and the contact lens solution displayed the highest percentages of apoptotic cells when compared with the other treatment groups at room temperature. Overall, cells treated on ice showed significantly lower levels of apoptosis when compared with treatments at room temperature. In conclusion, the results indicated that apoptosis plays a major role in cell death in cells treated with Gatorade and contact lens solutions in comparison to other storage solutions and that storage on ice can inhibit programed cell death. PMID:18173658

  7. Cancer cell death by design: apoptosis, autophagy and glioma virotherapy.

    PubMed

    Tyler, Matthew A; Ulasov, Ilya V; Lesniak, Maciej S

    2009-08-01

    Autophagy has been defined as a mechanism by which oncolytic adenoviruses mediate cell killing in some cancers, including malignant glioma. Until recently, however, adenovirus replication was regarded as a process that induced classical apoptosis in the infected cell. We have assessed the method of conditionally replicating adenovirus (CRAd) death in a model of malignant glioma, considering both autophagy and apoptosis as possible mechanisms of virally-induced cell death. Our initial investigations indicated that autophagy was the predominant system in CRAd-induced cell death in glioma. This appeared to be the case in vitro; however, further investigation in vivo shows that CRAds are capable of inducing both apoptotic and autophagic cell death. In this punctum, we summarize our latest research to uncover the method of oncolytic adenovirus-induced cell death in malignant glioma. Elucidating the relationship between autophagy and apoptosis in glioma virotherapy has significant implications for the design of optimal viral vectors. PMID:19430207

  8. Plasma-activated medium induced apoptosis on tumor cells

    NASA Astrophysics Data System (ADS)

    Hori, Masaru; Tanaka, Hiromasa; Mizuno, Masaaki; Nakamura, Kae; Kajiyama, Hiroaki; Takeda, Keigo; Ishikawa, Kenji; Kano, Hiroyuki; Kikkawa, Fumitaka

    2013-09-01

    The non-equilibrium atmospheric pressure plasma (NEAPP) has attracted attention in cancer therapy. In this study, the fresh medium was treated with our developed NEAPP, ultra-high electron density (approximately 2 × 1016 cm-3). The medium called the plasma-activated medium (PAM) killed not normal cells but tumor cells through induction of apoptosis. Cell proliferation assays showed that the tumor cells were selectively killed by the PAM. Those cells induced apoptosis using an apoptotic molecular marker, cleaved Caspase3/7. The molecular mechanisms of PAM-mediated apoptosis in the tumor cells were also found that the PAM downregulated the expression of AKT kinase, a marker molecule in a survival signal transduction pathway. These results suggest that PAM may be a promising tool for tumor therapy by downregulating the survival signals in cancers.

  9. Redox active copper chelate overcomes multidrug resistance in T-lymphoblastic leukemia cell by triggering apoptosis.

    PubMed

    Ganguly, Avishek; Basu, Soumya; Banerjee, Kaushik; Chakraborty, Paramita; Sarkar, Avijit; Chatterjee, Mitali; Chaudhuri, Soumitra Kumar

    2011-05-01

    Multidrug resistance (MDR) mediated by the over expression of drug efflux protein P-glycoprotein (P-gp) is one of the major impediments to successful treatment of cancer. P-gp acts as an energy-dependent drug efflux pump and reduces the intracellular concentration of structurally unrelated drugs inside the cells. Therefore, there is an urgent need for development of new molecules that are less toxic to normal cell and preferentially effective against drug resistant malignant cells. In this preclinical study we report the apoptotic potential of copper N-(2-hydroxyacetophenone) glycinate (CuNG) on doxorubicin resistant T lymphoblastic leukaemia cells (CEM/ADR5000). To evaluate the cytotoxic effect of CuNG, we used different normal cell lines (NIH 3T3, Chang liver and human PBMC) and cancerous cell lines (CEM/ADR5000, parental sensitive CCRF-CEM, SiHa and 3LL) and conclude that CuNG preferentially kills cancerous cells, especially both leukemic cell types irrespective of their MDR status, while leaving normal cell totally unaffected. Moreover, CuNG involves reactive oxygen species (ROS) for induction of apoptosis in CEM/ADR5000 cells through the intrinsic apoptotic pathway. This is substantiated by our observation that antioxidant N-acetyle-cysteine (NAC) and PEG catalase could completely block ROS generation and, subsequently, abrogates CuNG induced apoptosis. On the other hand, uncomplexed ligand N-(2-hydroxyacetophenone) glycinate (NG) fails to generate a significant amount of ROS and concomitant induction of apoptosis in CEM/ADR5000 cells. Therefore, CuNG induces drug resistant leukemia cells to undergo apoptosis and proves to be a molecule having therapeutic potential to overcome MDR in cancer. PMID:21409205

  10. Bartonella henselae inhibits apoptosis in Mono Mac 6 cells.

    PubMed

    Kempf, Volkhard A J; Schairer, Annette; Neumann, Diana; Grassl, Guntram A; Lauber, Kirsten; Lebiedziejewski, Maria; Schaller, Martin; Kyme, Pierre; Wesselborg, Sebastian; Autenrieth, Ingo B

    2005-01-01

    Bartonella henselae causes the vasculoproliferative disorders bacillary angiomatosis and peliosis probably resulting from the release of vasculoendothelial growth factor (VEGF) from infected epithelial or monocytic host cells. Here we demonstrate that B. henselae in addition to VEGF induction was also capable of inhibiting the endogenous sucide programme of monocytic host cells. Our results show that B. henselae inhibits pyrrolidine dithiocarbamate (PDTC)-induced apoptosis in Mono Mac 6 cells. B. henselae was observed to be present in a vacuolic compartment of Mono Mac 6 cells. Direct contact of B. henselae with Mono Mac 6 cells was crucial for inhibition of apoptosis as shown by the use of a two-chamber model. Inhibition of apoptosis was paralleled by diminished caspase-3 activity which was significantly reduced in PDTC-stimulated and B. henselae-infected cells. The anti-apoptotic effect of B. henselae was accompanied by (i) the activation of the transcription factor NF-kappaB and (ii) the induction of cellular inhibitor of apoptosis proteins-1 and -2 (cIAP-1, -2). Our results suggest a new synergistic mechanism in B. henselae pathogenicity by (i) inhibition of host cell apoptosis via activation of NF-kappaB and (ii) induction of host cell VEGF secretion. PMID:15617526

  11. Buthionine sulfoximine sensitizes antihormone-resistant human breast cancer cells to estrogen-induced apoptosis

    PubMed Central

    Lewis-Wambi, Joan S; Kim, Helen R; Wambi, Chris; Patel, Roshani; Pyle, Jennifer R; Klein-Szanto, Andres J; Jordan, V Craig

    2008-01-01

    Introduction Estrogen deprivation using aromatase inhibitors is one of the standard treatments for postmenopausal women with estrogen receptor (ER)-positive breast cancer. However, one of the consequences of prolonged estrogen suppression is acquired drug resistance. Our group is interested in studying antihormone resistance and has previously reported the development of an estrogen deprived human breast cancer cell line, MCF-7:5C, which undergoes apoptosis in the presence of estradiol. In contrast, another estrogen deprived cell line, MCF-7:2A, appears to have elevated levels of glutathione (GSH) and is resistant to estradiol-induced apoptosis. In the present study, we evaluated whether buthionine sulfoximine (BSO), a potent inhibitor of glutathione (GSH) synthesis, is capable of sensitizing antihormone resistant MCF-7:2A cells to estradiol-induced apoptosis. Methods Estrogen deprived MCF-7:2A cells were treated with 1 nM 17β-estradiol (E2), 100 μM BSO, or 1 nM E2 + 100 μM BSO combination in vitro, and the effects of these agents on cell growth and apoptosis were evaluated by DNA quantitation assay and annexin V and terminal deoxynucleotidyl transferase dUTP nick end-labeling (TUNEL) staining. The in vitro results of the MCF-7:2A cell line were further confirmed in vivo in a mouse xenograft model. Results Exposure of MCF-7:2A cells to 1 nM E2 plus 100 μM BSO combination for 48 to 96 h produced a sevenfold increase in apoptosis whereas the individual treatments had no significant effect on growth. Induction of apoptosis by the combination treatment of E2 plus BSO was evidenced by changes in Bcl-2 and Bax expression. The combination treatment also markedly increased phosphorylated c-Jun N-terminal kinase (JNK) levels in MCF-7:2A cells and blockade of the JNK pathway attenuated the apoptotic effect of E2 plus BSO. Our in vitro findings corroborated in vivo data from a mouse xenograft model in which daily administration of BSO either as a single agent or in

  12. Taurine induces the apoptosis of breast cancer cells by regulating apoptosis-related proteins of mitochondria.

    PubMed

    Zhang, Xiali; Lu, Hongfei; Wang, Yibing; Liu, Chunju; Zhu, Weifeng; Zheng, Shuangyan; Wan, Fusheng

    2015-01-01

    Taurine (Tau), the most abundant free amino acid in humans has numerous potential health benefits through its antioxidant and anti-inflammatory properties. However, limited studies have assessed its effect on tumors and the antitumor mechanism remains unknown. The present study investigated the cellular and molecular changes induced by Tau, leading to the induction of apoptosis in human breast cancer cell lines MCF-7 and MDA-MB-231. MCF-7 is p53 proficient (p53+/+) and MDA-MB-231 is a p53 null mutant (p53-/-). Cell proliferation and viability were assessed by MTT. Flow cytometry and hoechst33342 fluorescent staining were employed to detect apoptosis. Spectrophotometry was used to detect caspase-3 activity. Reverse transcription-polymerase chain reaction and western blot analysis were used to detect the levels of mRNA and proteins of p53-upregulated modulator of apoptosis (PUMA), Bax and Bcl-2. Finally, the affect of Tau on the growth of MDA-MB-231-cell-nude mice xenografts was examined. In the study, Tau inhibited growth and induced apoptosis of the two cell lines in a concentration- and time-dependent manner. Notably, the inhibitory effect of Tau on p53-/- cancer cells was clearly significant compared to the p53+/+ cancer cells. Further studies showed that Tau promoted apoptosis in human breast cancer cells and inhibited the growth of tumor in nude mice by inducing the expression of PUMA, which further up- and downregulated the expression of Bax and Bcl-2 protein, giving rise to increased activation of caspase-3. Collectively, these results indicate that Tau is a potent candidate for the chemotherapy of breast cancer through increasing the PUMA expression independent of p53 status. PMID:25395275

  13. Comparison of Types of Cell Death: Apoptosis and Necrosis.

    ERIC Educational Resources Information Center

    Manning, Francis; Zuzel, Katherine

    2003-01-01

    Cell death is an essential factor in many biological processes including development. Discusses two types of cell death: (1) necrosis (induced by sodium azide); and (2) apoptosis (induced by sodium chromate). Illustrates key features that differ between these two types of cells death including loss of membrane integrity and internucleosomal DNA…

  14. Antioxidants induce apoptosis of rat ovarian theca-interstitial cells.

    PubMed

    Rzepczynska, Izabela J; Foyouzi, Nastaran; Piotrowski, Piotr C; Celik-Ozenci, Ciler; Cress, Amanda; Duleba, Antoni J

    2011-01-01

    Regulation of growth of ovarian theca-interstitial tissues is essential for normal ovarian development and function. Reactive oxygen species are involved in modulation of signal transduction pathways, including regulation of tissue growth and apoptosis. Previously, we have demonstrated that antioxidants inhibit proliferation of theca-interstitial cells. This report evaluates the effects of antioxidants on apoptosis of rat theca-interstitial cells. The cells were cultured in chemically defined media without or with vitamin E succinate and ebselen. Apoptosis was evaluated by cytochemical assessment of nuclear morphology, activity of executioner caspases 3 and 7, and determination of staining with annexin V in combination with propidium iodide. Both tested antioxidants induced significant morphological changes consistent with apoptosis, including chromatin condensation, nuclear shrinkage, and pyknosis. Antioxidants also induced other hallmarks of apoptosis including increased activity of caspases 3/7 as well as increased staining with annexin V. The present findings demonstrate that antioxidants with distinctly different mechanisms of action induce a series of events consistent with the process of apoptosis in ovarian mesenchyme. These observations may be of translational-clinical relevance, providing mechanistic support for the use of antioxidants in the treatment of PCOS, a condition associated with excessive growth and activity of theca-interstitial cells. PMID:20844276

  15. Purkinje cell apoptosis in arabian horses with cerebellar abiotrophy.

    PubMed

    Blanco, A; Moyano, R; Vivo, J; Flores-Acuña, R; Molina, A; Blanco, C; Monterde, J G

    2006-08-01

    Purkinje cerebellar cells were studied in three Arabian horses aged between 6 and 8 months with clinical disorders in their movements, tremors and ataxia; the occurrence of apoptosis in this cell population was investigated by the (terminal deoxynucleotidyl transferase biotin-dUTP nick-end labelling (TUNEL) method. Both optical and electron microscopical images showed a scant number of Purkinje cells, most of them with morphological features of apoptosis such as condensation of the nucleus and cytoplasm as well as segregation and fragmentation of the nucleus into apoptotic bodies. The TUNEL technique revealed a substantial number (65%) of positive immunoreactive Purkinje cells. PMID:16901270

  16. DNA polymerase eta undergoes alternative splicing, protects against UV sensitivity and apoptosis, and suppresses Mre11-dependent recombination.

    PubMed

    Thakur, M; Wernick, M; Collins, C; Limoli, C L; Crowley, E; Cleaver, J E

    2001-11-01

    Polymerase eta (pol eta) is a low-fidelity DNA polymerase that is the product of the gene, POLH, associated with the human XP variant disorder in which there is an extremely high level of solar-induced skin carcinogenesis. The complete human genomic sequence spans about 40 kb containing 10 coding exons and a cDNA of 2.14 kb; exon I is untranslated and is 6 kb upstream from the first coding exon. Using bacterial artificial chromosomes (BACs), the gene was mapped to human chromosome band 6p21 and mouse band 17D. The gene is expressed in most tissues, except for very low or undetectable levels in peripheral lymphocytes, fetal spleen, and adult muscle; exon II, however, is frequently spliced out in normal cells and in almost half the transcripts in the testis and fetal liver. Expression of POLH in a multicopy episomal vector proved nonviable, suggesting that overexpression is toxic. Expression from chromosomally integrated linear copies using either an EF1-alpha or CMV promoter was functional, resulting in cell lines with low or high levels of pol eta protein, respectively. Point mutations in the center of the gene and in a C-terminal cysteine and deletion of exon II resulted in inactivation, but addition of a terminal 3 amino acid C-terminal tag, or an N- or C-terminal green fluorescent protein, had no effect on function. A low level of expression of pol eta eliminated hMre11 recombination and partially restored UV survival, but did not prevent UV-induced apoptosis, which required higher levels of expression. Polymerase eta is therefore involved in S-phase checkpoint and signal transduction pathways that lead to arrest in S, apoptosis, and recombination. In normal cells, the predominant mechanism of replication of UV damage involves pol eta-dependent bypass, and Mre11-dependent recombination that acts is a secondary, backup mechanism when cells are severely depleted of pol eta. PMID:11579462

  17. Retinoic Acid-Treated Pluripotent Stem Cells Undergoing Neurogenesis Present Increased Aneuploidy and Micronuclei Formation

    PubMed Central

    Sartore, Rafaela C.; Campos, Priscila B.; Trujillo, Cleber A.; Ramalho, Bia L.; Negraes, Priscilla D.; Paulsen, Bruna S.; Meletti, Tamara; Costa, Elaine S.; Chicaybam, Leonardo; Bonamino, Martin H.; Ulrich, Henning; Rehen, Stevens K.

    2011-01-01

    The existence of loss and gain of chromosomes, known as aneuploidy, has been previously described within the central nervous system. During development, at least one-third of neural progenitor cells (NPCs) are aneuploid. Notably, aneuploid NPCs may survive and functionally integrate into the mature neural circuitry. Given the unanswered significance of this phenomenon, we tested the hypothesis that neural differentiation induced by all-trans retinoic acid (RA) in pluripotent stem cells is accompanied by increased levels of aneuploidy, as previously described for cortical NPCs in vivo. In this work we used embryonal carcinoma (EC) cells, embryonic stem (ES) cells and induced pluripotent stem (iPS) cells undergoing differentiation into NPCs. Ploidy analysis revealed a 2-fold increase in the rate of aneuploidy, with the prevalence of chromosome loss in RA primed stem cells when compared to naïve cells. In an attempt to understand the basis of neurogenic aneuploidy, micronuclei formation and survivin expression was assessed in pluripotent stem cells exposed to RA. RA increased micronuclei occurrence by almost 2-fold while decreased survivin expression by 50%, indicating possible mechanisms by which stem cells lose their chromosomes during neural differentiation. DNA fragmentation analysis demonstrated no increase in apoptosis on embryoid bodies treated with RA, indicating that cell death is not the mandatory fate of aneuploid NPCs derived from pluripotent cells. In order to exclude that the increase in aneuploidy was a spurious consequence of RA treatment, not related to neurogenesis, mouse embryonic fibroblasts were treated with RA under the same conditions and no alterations in chromosome gain or loss were observed. These findings indicate a correlation amongst neural differentiation, aneuploidy, micronuclei formation and survivin downregulation in pluripotent stem cells exposed to RA, providing evidence that somatically generated chromosomal variation accompanies

  18. Massage for Children Undergoing Hematopoietic Cell Transplantation: A Qualitative Report

    PubMed Central

    Ackerman, Sara L.; Lown, E. Anne; Dvorak, Christopher C.; Dunn, Elizabeth A.; Abrams, Donald I.; Horn, Biljana N.; Degelman, Marcia; Cowan, Morton J.; Mehling, Wolf E.

    2012-01-01

    Background. No in-depth qualitative research exists about the effects of therapeutic massage with children hospitalized to undergo hematopoietic cell transplantation (HCT). The objective of this study is to describe parent caregivers' experience of the effects of massage/acupressure for their children undergoing HCT. Methods. We conducted a qualitative analysis of open-ended interviews with 15 parents of children in the intervention arm of a massage/acupressure trial. Children received both practitioner and parent-provided massage/acupressure. Results. Parents reported that their child experienced relief from pain and nausea, relaxation, and greater ease falling asleep. They also reported increased caregiver competence and closeness with their child as a result of learning and performing massage/acupressure. Parents supported a semistandardized massage protocol. Conclusion. Massage/acupressure may support symptom relief and promote relaxation and sleep among pediatric HCT patients if administered with attention to individual patients' needs and hospital routines and may relieve stress among parents, improve caregiver competence, and enhance the sense of connection between parent and child. PMID:22474526

  19. Do all programmed cell deaths occur via apoptosis?

    PubMed Central

    Schwartz, L M; Smith, S W; Jones, M E; Osborne, B A

    1993-01-01

    During development, large numbers of cells die by a nonpathological process referred to as programmed cell death. In many tissues, dying cells display similar changes in morphology and chromosomal DNA organization, which has been termed apoptosis. Apoptosis is such a widely documented phenomenon that many authors have assumed all programmed cell deaths occur by this process. Two well-characterized model systems for programmed cell death are (i) the death of T cells during negative selection in the mouse thymus and (ii) the loss of intersegmental muscles of the moth Manduca sexta at the end of metamorphosis. In this report we compare the patterns of cell death displayed by T cells and the intersegmental muscles and find that they differ in terms of cell-surface morphology, nuclear ultrastructure, DNA fragmentation, and polyubiquitin gene expression. Unlike the T cells, which are known to die via apoptosis, we find that the intersegmental muscles display few of the features that characterize apoptosis. These data suggest that more than one cell death mechanism is used during development. Images PMID:8430112

  20. MG132, a proteasome inhibitor, induces apoptosis in tumor cells.

    PubMed

    Guo, Na; Peng, Zhilan

    2013-03-01

    The balance between cell proliferation and apoptosis is critical for normal development and for the maintenance of homeostasis in adult organisms. Disruption of this balance has been implicated in a large number of disease processes, ranging from autoimmunity and neurodegenerative disorders to cancer. The ubiquitin-proteasome pathway, responsible for mediating the majority of intracellular proteolysis, plays a crucial role in the regulation of many normal cellular processes, including the cell cycle, differentiation and apoptosis. Apoptosis in cancer cells is closely connected with the activity of ubiquitin-proteasome pathway. The peptide-aldehyde proteasome inhibitor MG132 (carbobenzoxyl-L-leucyl-L-leucyl-L-leucine) induces the apoptosis of cells by a different intermediary pathway. Although the pathway of induction of apoptosis is different, it plays a crucial role in anti-tumor treatment. There are many cancer-related molecules in which the protein levels present in cells are regulated by a proteasomal pathway; for example, tumor inhibitors (P53, E2A, c-Myc, c-Jun, c-Fos), transcription factors (transcription factor nuclear factor-kappa B, IκBα, HIFI, YYI, ICER), cell cycle proteins (cyclin A and B, P27, P21, IAP1/3), MG132 induces cell apoptosis through formation of reactive oxygen species or the upregulation and downregulation of these factors, which is ultimately dependent upon the activation of the caspase family of cysteine proteases. In this article we review the mechanism of the induction of apoptosis in order to provide information required for research. PMID:22897979

  1. The Roles of ROS and Caspases in TRAIL-Induced Apoptosis and Necroptosis in Human Pancreatic Cancer Cells

    PubMed Central

    Zhang, Min; Harashima, Nanae; Moritani, Tamami; Huang, Weidong; Harada, Mamoru

    2015-01-01

    Death signaling provided by tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) can induce death in cancer cells with little cytotoxicity to normal cells; this cell death has been thought to involve caspase-dependent apoptosis. Reactive oxygen species (ROS) are also mediators that induce cell death, but their roles in TRAIL-induced apoptosis have not been elucidated fully. In the current study, we investigated ROS and caspases in human pancreatic cancer cells undergoing two different types of TRAIL-induced cell death, apoptosis and necroptosis. TRAIL treatment increased ROS in two TRAIL-sensitive pancreatic cancer cell lines, MiaPaCa-2 and BxPC-3, but ROS were involved in TRAIL-induced apoptosis only in MiaPaCa-2 cells. Unexpectedly, inhibition of ROS by either N-acetyl-L-cysteine (NAC), a peroxide inhibitor, or Tempol, a superoxide inhibitor, increased the annexin V-/propidium iodide (PI)+ early necrotic population in TRAIL-treated cells. Additionally, both necrostatin-1, an inhibitor of receptor-interacting protein kinase 1 (RIP1), and siRNA-mediated knockdown of RIP3 decreased the annexin V-/PI+ early necrotic population after TRAIL treatment. Furthermore, an increase in early apoptosis was induced in TRAIL-treated cancer cells under inhibition of either caspase-2 or -9. Caspase-2 worked upstream of caspase-9, and no crosstalk was observed between ROS and caspase-2/-9 in TRAIL-treated cells. Together, these results indicate that ROS contribute to TRAIL-induced apoptosis in MiaPaCa-2 cells, and that ROS play an inhibitory role in TRAIL-induced necroptosis of MiaPaCa-2 and BxPC-3 cells, with caspase-2 and -9 playing regulatory roles in this process. PMID:26000607

  2. The role of cytochrome c on apoptosis induced by Anagrapha falcifera multiple nuclear polyhedrosis virus in insect Spodoptera litura cells.

    PubMed

    Liu, Kaiyu; Shu, Duanyang; Song, Na; Gai, Zhongchao; Yuan, Yuan; Li, Juan; Li, Min; Guo, Shuying; Peng, Jianxin; Hong, Huazhu

    2012-01-01

    There are conflicting reports on the role of cytochrome c during insect apoptosis. Our previous studies have showed that cytochrome c released from the mitochondria was an early event by western blot analysis and caspase-3 activation was closely related to cytochrome c release during apoptosis induced by baculovirus in Spodoptera litura cells (Sl-1 cell line). In the present study, alteration in mitochondrial morphology was observed by transmission electron microscopy, and cytochrome c release from mitochondria in apoptotic Sl-1 cells induced with Anagrapha falcifera multiple nuclear polyhedrosis virus (AfMNPV) has further been confirmed by immunofluoresence staining protocol, suggesting that structural disruption of mitochondria and the release of cytochrome c are important events during Lepidoptera insect cell apoptosis. We also used Sl-1 cell-free extract system and the technique of RNA interference to further investigate the role of cytochrome c in apoptotic Sl-1 cells induced by AfMNPV. Caspase-3 activity in cell-free extracts supplemented with exogenous cytochrome c was determined and showed an increase with the extension of incubation time. DsRNA-mediated silencing of cytochrome c resulted in the inhibition of apoptosis and protected the cells from AfMNPV-induced cell death. Silencing of expression of cytochrome c had a remarkable effect on pro-caspase-3 and pro-caspase-9 activation and resulted in the reduction of caspase-3 and caspase-9 activity in Sl-1 cells undergoing apoptosis. Caspase-9 inhibitor could inhibit activation of pro-caspase-3, and the inhibition of the function of Apaf-1 with FSBA blocked apoptosis, hinting that Apaf-1 could be involved in Sl-1 cell apoptosis induced by AfMNPV. Taken together, these results strongly demonstrate that cytochrome c plays an important role in apoptotic signaling pathways in Lepidopteran insect cells. PMID:22952575

  3. Induction of apoptosis in human endothelial cells by nanodiamond particles.

    PubMed

    Solarska, K; Gajewska, A; Bartosz, G; Mitura, K

    2012-06-01

    Carbon nanoparticles are a promising material which finds application in different fields in industry and medicine. For medical applications, biocompatibility of nanoparticles is of critical importance because a lot of medical implants are coated by carbon coating. Our previous results showed that nanoparticles may induce increased production of ROS by the cells so we decided to checked if nanopowders can induce apoptosis. Apoptosis was quantified by double-staining with acridine orange and ethidium bromide. For comparison, we identified apoptotic cells with annexin V-FITC/propidium iodide. Our data demonstrate that treatment of the cells with diamond nanopowders may induce apoptosis and necrosis and this effect is dependent on the time of treatment and concentration of the nanopowders. The highest level of apoptotic cells was observed after incubation with Ultrananocrystalline Detonation Diamond (UDD) suggesting that the size is the main determinant of nanoparticle cytotoxicity. PMID:22905588

  4. Neuropeptide Y directly affects ovarian cell proliferation and apoptosis.

    PubMed

    Sirotkin, Alexander V; Kardošová, Diana; Alwasel, Saleh Hamad; Harrath, Abdel Halim

    2015-12-01

    The effects of neuropeptide Y (NPY; 0, 10, 100 and 1000 ng/mL) on the expression of PCNA, bax and p53 were examined by immunocytochemistry in porcine luteinized granulosa cells. NPY inhibited proliferation as well as promoted apoptosis and accumulation of p53 in the cells. This is the first report to demonstrate the direct action of NPY on ovarian cell proliferation and apoptosis. The results of the study suggest that the effect is mediated by transcription factor p53. PMID:26679167

  5. Taxol produced from endophytic fungi induces apoptosis in human breast, cervical and ovarian cancer cells.

    PubMed

    Wang, Xin; Wang, Chao; Sun, Yu-Ting; Sun, Chuan-Zhen; Zhang, Yue; Wang, Xiao-Hua; Zhao, Kai

    2015-01-01

    Currently, taxol is mainly extracted from the bark of yews; however, this method can not meet its increasing demand on the market because yews grow very slowly and are a rare and endangered species belonging to first- level conservation plants. Recently, increasing efforts have been made to develop alternative means of taxol production; microbe fermentation would be a very promising method to increase the production scale of taxol. To determine the activities of the taxol extracted from endophytic fungus N. sylviforme HDFS4-26 in inhibiting the growth and causing the apoptosis of cancer cells, on comparison with the taxol extracted from the bark of yew, we used cellular morphology, cell counting kit (CCK-8) assay, staining (HO33258/PI and Giemsa), DNA agarose gel electrophoresis and flow cytometry (FCM) analyses to determine the apoptosis status of breast cancer MCF-7 cells, cervical cancer HeLa cells and ovarian cancer HO8910 cells. Our results showed that the fungal taxol inhibited the growth of MCF-7, HeLa and HO8910 cells in a dose-and time-dependent manner. IC50 values of fungal taxol for HeLa, MCF-7 and HO8910 cells were 0.1-1.0 μg/ml, 0.001-0.01 μg/ml and 0.01- 0.1 μg/ml, respectively. The fungal taxol induced these tumor cells to undergo apoptosis with typical apoptotic characteristics, including morphological changes for chromatin condensation, chromatin crescent formation, nucleus fragmentation, apoptotic body formation and G2/M cell cycle arrest. The fungal taxol at the 0.01-1.0 μg/ ml had significant effects of inducing apoptosis between 24-48 h, which was the same as that of taxol extracted from yews. This study offers important information and a new resource for the production of an important anticancer drug by endofungus fermentation. PMID:25640339

  6. Effect of oxysterol-induced apoptosis of vascular smooth muscle cells on experimental hypercholesterolemia.

    PubMed

    Perales, Sonia; Alejandre, M José; Palomino-Morales, Rogelio; Torres, Carolina; Iglesias, Jose; Linares, Ana

    2009-01-01

    Smooth muscle cells (SMCs) undergo changes related to proliferation and apoptosis in the physiological remodeling of vessels and in diseases such as atherosclerosis and restenosis. Recent studies also have demonstrated the vascular cell proliferation and programmed cell death contribute to changes in vascular architecture in normal development and in disease. The present study was designed to investigate the apoptotic pathways induced by 25-hydroxycholesterol in SMCs cultures, using an in vivo/in vitro cell model in which SMCs were isolated and culture from chicken exposed to an atherogenic cholesterol-rich diet (SMC-Ch) and/or an antiatherogenic fish oil-rich diet (SMC-Ch-FO). Cells were exposed in vitro to 25-hydroxycholesterol to study levels of apoptosis and apoptotic proteins Bcl-2, Bcl-X(L) and Bax and the expression of bcl-2 and bcl-x(L), genes. The quantitative real-time reverse transcriptase-polymerase chain reaction and the Immunoblotting western blot analysis showed that 25-hydroxycholesterol produces apoptosis in SMCs, mediated by a high increase in Bax protein and Bax gene expression. These changes were more marked in SMC-Ch than in SMC-Ch-FO, indicating that dietary cholesterol produces changes in SMCs that make them more susceptible to 25-hydroxycholesterol-mediated apoptosis. Our results suggest that the replacement of a cholesterol-rich diet with a fish oil-rich diet produces some reversal of cholesterol-induced changes in the apoptotic pathways induced by 25-hydroxycholesterol in SMCs cultures, making SMCs more resistant to apoptosis. PMID:19727411

  7. Parkia javanica Extract Induces Apoptosis in S-180 Cells via the Intrinsic Pathway of Apoptosis.

    PubMed

    Patra, Kartick; Jana, Samarjit; Sarkar, Arnab; Karmakar, Subrata; Jana, Jagannath; Gupta, Mradu; Mukherjee, Gopeswar; De, Utpal Chandra; Mandal, Deba Prasad; Bhattacharjee, Shamee

    2016-01-01

    Parkia javanica is a leguminous tree, various parts of which are used as food and folklore medicine by the ethnic groups of northeastern India. The present study investigates the in vitro and in vivo anticancer effect of aqueous methanol extract of P. javanica fruit (PJE). HPLC analysis was done to establish the fingerprint chromatogram of PJE and its in vitro radical scavenging activity was measured. PJE caused significant cytotoxicity in sarcoma-180 (S-180), A549, AGS, and MDA-MB435S cancer cells in vitro. Exploration of the mechanistic details in S-180 cells suggested that the reduced cell viability was mediated by induction of apoptosis. Increased expression of proapoptotic proteins such as p53, p21, Bax/Bcl2, cytochrome c (Cyt c), caspase 9, and cleaved poly(ADP-ribose) polymerase, and decrease in proliferative and antiapoptotic markers (Ki-67, Proliferating Cell Nuclear Antigen [PCNA], Bcl-2) validated the anticancer effect of PJE. A decline in the relative fluorescence emission upon staining S-180 cells with Rhodamine 123 (Rh 123), enhanced expression of cytosolic Cyt c and mitochondrial Bax, and inhibition of apoptosis in the presence of caspase-9 inhibitor in PJE-treated cells indicated intrinsic pathway of apoptosis. Liver function test and hepatic antioxidant enzymes demonstrated non-toxicity of PJE. Finally, the detection of PJE in sera by HPLC confirmed its bioavailability. PMID:27144503

  8. Cooperative interactions between RB and p53 regulate cell proliferation, cell senescence, and apoptosis in human vascular smooth muscle cells from atherosclerotic plaques.

    PubMed

    Bennett, M R; Macdonald, K; Chan, S W; Boyle, J J; Weissberg, P L

    1998-04-01

    Compared with vascular smooth muscle cells (VSMCs) from normal vessels, VSMCs from human atherosclerotic plaques proliferate more slowly, undergo earlier senescence, and demonstrate higher levels of apoptosis in culture. The tumor suppressor genes p105RB (retinoblastoma, acting through the E2F transcription factor family) and p53 regulate cell proliferation, cell senescence, and apoptosis in many cell types. We have therefore determined whether these stable growth properties of plaque VSMCs reflect altered activity of RB and/or p53. VSMCs were derived from coronary atherectomies or from normal coronary arteries from transplant recipients. Compared with normal VSMCs, plaque VSMCs showed a higher ratio of the active (hypophosphorylated) to the inactive (phosphorylated) form of RB and a lower level of E2F transcriptional activity. Cells were stably transfected with retrovirus constructs that inhibited RB or p53 alone or in combination. Suppression of RB alone increased rates of cell proliferation and apoptosis and inhibited cell senescence in normal VSMCs. Suppression of p53 and RB together had similar effects but, additionally, resulted in immortalization of normal VSMC cultures. In contrast, inhibition of RB binding to E2F or ectopic expression of E2F-1 in plaque VSMCs induced massive apoptosis, which required suppression of p53 to rescue cells. Suppression of RB and p53 together increased cell proliferation and delayed senescence but failed to immortalize plaque VSMCs. Inhibition of p53 alone had minimal effects on plaque VSMCs but increased the lifespan of normal VSMCs. We conclude that human plaque VSMCs have slower rates of cell proliferation and earlier senescence than do cells from normal vessels because of a defect in phosphorylation of RB. Furthermore, both disruption of RB/E2F and inhibition of p53 are required for plaque VSMCs to proliferate without apoptosis. This observation may explain the relatively low level of cell proliferation and high level of

  9. The CD8+ granzyme B+ T-cell subset in peripheral blood from healthy individuals contains activated and apoptosis-prone cells.

    PubMed Central

    Wever, P C; Van Der Vliet, H J; Spaeny, L H; Wolbink, A M; Van Diepen, F N; Froelich, C J; Hack, C E; ten Berge, I J

    1998-01-01

    Granzyme B (GrB) has been implicated in induction of apoptosis in target cells. The presence of GrB in peripheral blood CD8+ T cells from healthy individuals was analysed in immunocytochemical and flow cytometric studies. Furthermore, CD8+ GrB- T cells and CD8+ GrB+ T cells were compared regarding phenotypical characteristics and susceptibility to both spontaneous and Fasmediated apoptosis. GrB was expressed by approximately one-fifth of CD8+ T cells. Compared with the CD8+ GrB- T-cell subset, the CD8+ GrB+ T-cell subset contained cells that were relatively more activated and more prone to spontaneous apoptosis. Culturing of cells with immunoglobulin M (IgM) anti-Fas monoclonal antibody had no additional effect on the number of CD8+ GrB+ T cells undergoing apoptosis. We suggest that the presence of CD8+ GrB+ T cells in peripheral blood from healthy individuals results from immune surveillance or contact with infectious agents, and that spontaneous apoptosis of these cells might serve as a mechanism for their eventual clearance. Images Figure 1 PMID:9640249

  10. Mutant cystic fibrosis transmembrane conductance regulator inhibits acidification and apoptosis in C127 cells: possible relevance to cystic fibrosis.

    PubMed Central

    Gottlieb, R A; Dosanjh, A

    1996-01-01

    We have shown elsewhere that acidification is an early event in apoptosis, preceding DNA cleavage. Cells expressing the most common mutation (delF508) of the cystic fibrosis transmembrane regulator (CFTR) exhibit a higher resting intracellular pH and are unable to secrete chloride and bicarbonate in response to cAMP. We hypothesized that defective acidification in cells expressing delF508 CFTR would interfere with the acidification that accompanies apoptosis, which in turn, would prevent endonuclease activation and cleavage of DNA. We therefore determined whether the function of the CFTR would affect the process of apoptosis in mouse mammary epithelial C127 cells stably transfected with the wild-type CFTR (C127/wt) or the delF508 mutation of the CFTR (C127/508). C127 cells possessed an acid endonuclease capable of DNA degradation at low pH. Sixteen hours after treatment with cycloheximide, C127/wt cells underwent cytoplasmic acidification. In contrast, C127/508 cells failed to demonstrate acidification. Furthermore, the C127/508 cells did not show nuclear condensation or DNA fragmentation detected by in situ nick-end labeling after treatment with cycloheximide or etoposide, in contrast to the characteristic features of apoptosis demonstrated by the C127/wt cells. Measurement of cell viability indicated a preservation of cell viability in C127/508 cells but not in C127/wt cells. That this resistance to the induction of apoptosis depended upon the loss of CFTR activity is shown by the finding that inhibition of the CFTR with diphenylamine carboxylate in C127/wt cells conferred similar protection. These findings suggest a role for the CFTR in acidification during the initiation of apoptosis in epithelial cells and imply that a failure to undergo programmed cell death could contribute to the pathogenesis of cystic fibrosis. Images Fig. 1 Fig. 2 Fig. 3 PMID:8622979

  11. An increase of granulosa cell apoptosis mediates aqueous neem (Azadirachta indica) leaf extract-induced oocyte apoptosis in rat

    PubMed Central

    Tripathi, Anima; Shrivastav, Tulsidas G; Chaube, Shail K

    2013-01-01

    Objective: Neem plant (Azadirachta indica) has been extensively used in Ayurvedic system of medicine for female fertility regulation for a long time, but its mechanism of action remains poorly understood. Hence, the present study was aimed to determine whether an increase of granulosa cell apoptosis is associated with aqueous neem leaf extract (NLE)-induced oocyte apoptosis. Materials and Methods: Sexually immature female rats of 20 days old were fed NLE (50 mg/day) for 10 days and then subjected to superovulation induction protocol. The morphological changes in cumulus oocyte complexes (COCs), rate of oocyte apoptosis, hydrogen peroxide (H2O2), total nitrite, and cytochrome c concentrations, inducible nitric oxide synthase (iNOS), cytochrome c, p53, Bcl2 and Bax expressions, deoxyribonucleic acid (DNA) fragmentation, and estradiol 17β level in granulosa cells collected from preovulatory COCs were analyzed. Results: Aqueous NLE increased H2O2 concentration and decreased catalase activity, increased iNOS expression and total nitrite concentration, increased p53, Bax, and p53 expressions but decreased Bcl2 expression, increased cytochrome c concentration and induced DNA fragmentation in granulosa cells. An increased granulosa cell apoptosis resulted in reduced estradiol 17β concentration and induced apoptosis in ovulated oocytes. Conclusion: We conclude that aqueous NLE-induced granulosa cell apoptosis through the mitochondria-mediated pathway, reduced estradiol 17β concentration and induced apoptosis in ovulated oocytes. Thus, granulosa cell apoptosis mediates NLE-induced oocyte apoptosis during female fertility regulation in rat. PMID:23776837

  12. Daxx Upregulation within the Cytoplasm of Reovirus-Infected Cells Is Mediated by Interferon and Contributes to Apoptosis

    PubMed Central

    Dionne, Kalen R.; Zhuang, Yonghua; Leser, J. Smith; Tyler, Kenneth L.

    2013-01-01

    Reovirus infection is a well-characterized experimental system for the study of viral pathogenesis and antiviral immunity within the central nervous system (CNS). We have previously shown that c-Jun N-terminal kinase (JNK) and the Fas death receptor each play a role in neuronal apoptosis occurring in reovirus-infected brains. Death-associated protein 6 (Daxx) is a cellular protein that mechanistically links Fas signaling to JNK signaling in several models of apoptosis. In the present study, we demonstrate that Daxx is upregulated in reovirus-infected brain tissue through a type I interferon-mediated mechanism. Daxx upregulation is limited to brain regions that undergo reovirus-induced apoptosis and occurs in the cytoplasm and nucleus of neurons. Cytoplasmic Daxx is present in Fas-expressing cells during reovirus encephalitis, suggesting a role for Daxx in Fas-mediated apoptosis following reovirus infection. Further, in vitro expression of a dominant negative form of Daxx (DN-Daxx), which binds to Fas but which does not transmit downstream signaling, inhibits apoptosis of reovirus-infected cells. In contrast, in vitro depletion of Daxx results in increased expression of caspase 3 and apoptosis, suggesting that Daxx plays an antiapoptotic role in the nucleus. Overall, these data imply a regulatory role for Daxx in reovirus-induced apoptosis, depending on its location in the nucleus or cytoplasm. PMID:23302889

  13. Tocotrienol-rich fraction of palm oil induces cell cycle arrest and apoptosis selectively in human prostate cancer cells

    SciTech Connect

    Srivastava, Janmejai K.; Gupta, Sanjay . E-mail: sanjay.gupta@case.edu

    2006-07-28

    One of the requisite of cancer chemopreventive agent is elimination of damaged or malignant cells through cell cycle inhibition or induction of apoptosis without affecting normal cells. In this study, employing normal human prostate epithelial cells (PrEC), virally transformed normal human prostate epithelial cells (PZ-HPV-7), and human prostate cancer cells (LNCaP, DU145, and PC-3), we evaluated the growth-inhibitory and apoptotic effects of tocotrienol-rich fraction (TRF) extracted from palm oil. TRF treatment to PrEC and PZ-HPV-7 resulted in almost identical growth-inhibitory responses of low magnitude. In sharp contrast, TRF treatment resulted in significant decreases in cell viability and colony formation in all three prostate cancer cell lines. The IC{sub 5} values after 24 h TRF treatment in LNCaP, PC-3, and DU145 cells were in the order 16.5, 17.5, and 22.0 {mu}g/ml. TRF treatment resulted in significant apoptosis in all the cell lines as evident from (i) DNA fragmentation (ii) fluorescence microscopy, and (iii) cell death detection ELISA, whereas the PrEC and PZ-HPV-7 cells did not undergo apoptosis, but showed modestly decreased cell viability only at a high dose of 80 {mu}g/ml. In cell cycle analysis, TRF (10-40 {mu}g/ml) resulted in a dose-dependent G0/G1 phase arrest and sub G1 accumulation in all three cancer cell lines but not in PZ-HPV-7 cells. These results suggest that the palm oil derivative TRF is capable of selectively inhibiting cellular proliferation and accelerating apoptotic events in prostate cancer cells. TRF offers significant promise as a chemopreventive and/or therapeutic agent against prostate cancer.

  14. Sphingosine enhances apoptosis of radiation-resistant prostate cancer cells.

    PubMed

    Nava, V E; Cuvillier, O; Edsall, L C; Kimura, K; Milstien, S; Gelmann, E P; Spiegel, S

    2000-08-15

    Ceramide has been implicated as an important component of radiation-induced apoptosis of human prostate cancer cells. We examined the role of the sphingolipid metabolites--ceramide, sphingosine, and sphingosine-1-phosphate--in susceptibility to radiation-induced apoptosis in prostate cancer cell lines with different sensitivities to gamma-irradiation. Exposure of radiation-sensitive TSU-Pr1 cells to 8-Gy irradiation led to a sustained increase in ceramide, beginning after 12 h of treatment and increasing to 2.5- to 3-fold within 48 h. Moreover, irradiation of TSU-Pr1 cells also produced a marked and rapid 50% decrease in the activity of sphingosine kinase, the enzyme that phosphorylates sphingosine to form sphingosine-1-phosphate. In contrast, the radiation-insensitive cell line, LNCaP, had sustained sphingosine kinase activity and did not produce elevated ceramide levels on 8-Gy irradiation. Although LNCaP cells are highly resistant to gamma-irradiation-induced apoptosis, they are sensitive to the death-inducing effects of tumor necrosis factor alpha, which also increases ceramide levels in these cells (K. Kimura et al., Cancer Res., 59: 1606-1614, 1999). Moreover, we found that although irradiation alone did not increase sphingosine levels in LNCaP cells, tumor necrosis factor alpha plus irradiation induced significantly higher sphingosine levels and markedly reduced intracellular levels of sphingosine-1-phosphate. The elevation of sphingosine levels either by exogenous sphingosine or by treatment with the sphingosine kinase inhibitor N,N-dimethylsphingosine induced apoptosis and also sensitized LNCaP cells to gamma-irradiation-induced apoptosis. Our data suggest that the relative levels of sphingolipid metabolites may play a role in determining the radiosensitivity of prostate cancer cells, and that the enhancement of ceramide and sphingosine generation could be of therapeutic value. PMID:10969794

  15. Thyroid hormone and anti-apoptosis in tumor cells.

    PubMed

    Lin, Hung-Yun; Glinsky, Gennadi V; Mousa, Shaker A; Davis, Paul J

    2015-06-20

    The principal secretory product of the thyroid gland, L-thyroxine (T4), is anti-apoptotic at physiological concentrations in a number of cancer cell lines. Among the mechanisms of anti-apoptosis activated by the hormone are interference with the Ser-15 phosphorylation (activation) of p53 and with TNFα/Fas-induced apoptosis. The hormone also decreases cellular abundance and activation of proteolytic caspases and of BAX and causes increased expression of X-linked inhibitor of apoptosis (XIAP). The anti-apoptotic effects of thyroid hormone largely are initiated at a cell surface thyroid hormone receptor on the extracellular domain of integrin αvβ3 that is amply expressed and activated in cancer cells. Tetraiodothyroacetic acid (tetrac) is a T4 derivative that, in a model of resveratrol-induced p53-dependent apoptosis in glioma cells, blocks the anti-apoptotic action of thyroid hormone, permitting specific serine phosphorylation of p53 and apoptosis to proceed. In a nanoparticulate formulation limiting its action to αvβ3, tetrac modulates integrin-dependent effects on gene expression in human cancer cell lines that include increased expression of a panel of pro-apoptotic genes and decreased transcription of defensive anti-apoptotic XIAP and MCL1 genes. By a variety of mechanisms, thyroid hormone (T4) is an endogenous anti-apoptotic factor that may oppose chemotherapy-induced apoptosis in αvβ3-expressing cancer cells. It is possible to decrease this anti-apoptotic activity pharmacologically by reducing circulating levels of T4 or by blocking effects of T4 that are initiated at αvβ3. PMID:26041883

  16. Thyroid hormone and anti-apoptosis in tumor cells

    PubMed Central

    Lin, Hung-Yun; Glinsky, Gennadi V.; Mousa, Shaker A.; Davis, Paul J.

    2015-01-01

    The principal secretory product of the thyroid gland, L-thyroxine (T4), is anti-apoptotic at physiological concentrations in a number of cancer cell lines. Among the mechanisms of anti-apoptosis activated by the hormone are interference with the Ser-15 phosphorylation (activation) of p53 and with TNFα/Fas-induced apoptosis. The hormone also decreases cellular abundance and activation of proteolytic caspases and of BAX and causes increased expression of X-linked inhibitor of apoptosis (XIAP). The anti-apoptotic effects of thyroid hormone largely are initiated at a cell surface thyroid hormone receptor on the extracellular domain of integrin αvβ3 that is amply expressed and activated in cancer cells. Tetraiodothyroacetic acid (tetrac) is a T4 derivative that, in a model of resveratrol-induced p53-dependent apoptosis in glioma cells, blocks the anti-apoptotic action of thyroid hormone, permitting specific serine phosphorylation of p53 and apoptosis to proceed. In a nanoparticulate formulation limiting its action to αvβ3, tetrac modulates integrin-dependent effects on gene expression in human cancer cell lines that include increased expression of a panel of pro-apoptotic genes and decreased transcription of defensive anti-apoptotic XIAP and MCL1 genes. By a variety of mechanisms, thyroid hormone (T4) is an endogenous anti-apoptotic factor that may oppose chemotherapy-induced apoptosis in αvβ3-expressing cancer cells. It is possible to decrease this anti-apoptotic activity pharmacologically by reducing circulating levels of T4 or by blocking effects of T4 that are initiated at αvβ3. PMID:26041883

  17. GNE Myopathy and Cell Apoptosis: A Comparative Mutation Analysis.

    PubMed

    Singh, Reema; Arya, Ranjana

    2016-07-01

    In a number of genetic disorders such as GNE myopathy, it is not clear how mutations in target genes result in disease phenotype. GNE myopathy is a progressive neuro-degenerative disorder associated with homozygous or compound heterozygous missense mutations in either epimerase or kinase domain of UDP-GlcNAc 2-epimerase/ManNAc kinase (GNE). This bifunctional enzyme catalyses the rate limiting step in sialic acid biosynthesis. Many mechanisms have been suggested as possible cause of muscle degeneration. These include hyposialylation of critical proteins, defects in cytoskeletal network, sarcomere organization and apoptosis. In order to elucidate the role of GNE in cell apoptosis, we have used HEK cell-based model system overexpressing pathologically relevant GNE mutations. These cells display a reduction in the levels of sialic acid-bound glycoconjugates. These mutants GNE overexpressing cells have defect in cell proliferation as compared to vector or wild-type GNE (wtGNE) controls. Moreover, effect of different GNE mutations on cell apoptosis was also observed using staining with annexin V-FITC and TUNEL assay. The downstream apoptosis signalling pathway involving activation of caspases and increased PARP cleavage were observed in all GNE mutant cell lines. In addition, morpho-structural changes in mitochondria in cells overexpressing different GNE mutants were noticed by transmission electron microscopy, and mitochondrial transmembrane potential was found to be altered in absence of functional GNE. Our results clearly indicate role of GNE in mitochondria-dependent cell apoptosis and provide insights into the pathomechanism of GNE myopathy. PMID:25976366

  18. Dracorhodin perchlorate induces the apoptosis of glioma cells.

    PubMed

    Chen, Xin; Luo, Junjie; Meng, Linghu; Pan, Taifeng; Zhao, Binjie; Tang, Zhen-Gang; Dai, Yongjian

    2016-04-01

    Dracorhodin perchlorate (Dp), a synthetic analogue of the antimicrobial anthocyanin red pigment, has recently been shown to induce apoptotic cell death in various types of cancer cells. Yet, the inhibitory effect of Dp on human glioma cells remains uninvestigated. Therefore, in the present study, 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry were used to detect cell viability and cell cycle progression in glioma U87MG and T98G cells, respectively. Annexin V-FITC/propidium iodide double staining and JC-1 staining were separately applied to determine cellular apoptosis and mitochondrial membrane potential damage in the cells. The expression levels of associated proteins involved in cell cycle progression and apoptosis were measured by western blotting. The activities of caspase‑9/-3 were determined by Caspase-Glo-9/3 assay. The results indicated that Dp treatment significantly inhibited cell proliferation in a dose- and time-dependent manner, and blocked cell cycle progression at the G1/S phase in the U87MG and T98G cells via the upregulation of p53 and p21 protein expression, and simultaneous downregulation of Cdc25A, Cdc2 and P-Cdc2 protein expression. Additionally, Dp treatment led to the loss of cellular mitochondrial membrane potential, and the release of cytochrome c, and strongly induced the occurence of apoptosis. Increased expression levels of Bim and Bax protein and the downregulated expression of Bcl-2 protein were observed. Caspase-9/-3 were activated and their activities were elevated after Dp treatment. These findings indicate that Dp inhibits cell proliferation, induces cell cycle arrest and apoptosis in glioma cells, and is a possible candidate for glioma treatment. PMID:26846469

  19. Regulation of apoptosis of rbf mutant cells during Drosophila development

    PubMed Central

    Tanaka-Matakatsu, Miho; Xu, Jinhua; Cheng, Leping; Du, Wei

    2008-01-01

    Inactivation of the retinoblastoma gene Rb leads to defects in cell proliferation, differentiation, or apoptosis, depending on specific cell or tissue types. To gain insights into the genes that can modulate the consequences of Rb inactivation, we carried out a genetic screen in Drosophila to identify mutations that affected apoptosis induced by inactivation of the Retinoblastoma-family protein (rbf) and identified a mutation that blocked apoptosis induced by rbf. We found this mutation to be a new allele of head involution defective (hid) and showed that hid expression is deregulated in rbf mutant cells in larval imaginal discs. We identified an enhancer that regulates hid expression in response to developmental cues as well as to radiation and demonstrated that this hid enhancer is directly repressed by RBF through an E2F binding site. These observations indicate that apoptosis of rbf mutant cells is mediated by an upregulation of hid. Finally, we showed that bantam, a miRNA that regulates hid translation, is expressed in the interommatidial cells in the larval eye discs and modulates the survival of rbf mutant cells. PMID:19100727

  20. Inhibition of Single Minded 2 gene expression mediates tumor-selective apoptosis and differentiation in human colon cancer cells.

    PubMed

    Aleman, Mireille J; DeYoung, Maurice Phil; Tress, Matthew; Keating, Patricia; Perry, Gary W; Narayanan, Ramaswamy

    2005-09-01

    A Down's syndrome associated gene, Single Minded 2 gene short form (SIM2-s), is specifically expressed in colon tumors but not in the normal colon. Antisense inhibition of SIM2-s in a RKO-derived colon carcinoma cell line causes growth inhibition, apoptosis, and inhibition of tumor growth in a nude mouse tumoriginicity model. The mechanism of cell death in tumor cells is unclear. In the present study, we investigated the pathways underlying apoptosis. Apoptosis was seen in a tumor cell-specific manner in RKO cells but not in normal renal epithelial cells, despite inhibition of SIM2-s expression in both of these cells by the antisense. Apoptosis was depended on WT p53 status and was caspase-dependent; it was inhibited by a pharmacological inhibitor of mitogen-activated protein kinase activity. Expression of a key stress response gene, growth arrest and DNA damage gene (GADD)45alpha, was up-regulated in antisense-treated tumor cells but not in normal cells. In an isogenic RKO cell line expressing stable antisense RNA to GADD45alpha, a significant protection of the antisense-induced apoptosis was seen. Whereas antisense-treated RKO cells did not undergo cell cycle arrest, several markers of differentiation were deregulated, including alkaline phosphatase activity, a marker of terminal differentiation. Protection of apoptosis and block of differentiation showed a correlation in the RKO model. Our results support the tumor cell-selective nature of SIM2-s gene function, provide a direct link between SIM2-s and differentiation, and may provide a model to identify SIM2-s targets. PMID:16129820

  1. Apoptosis by Direct Current Treatment in Tumor Cells and Tissues

    NASA Astrophysics Data System (ADS)

    Kim, Hongbae; Sim, Sungbo; Ahn, Saeyoung

    2003-10-01

    Electric field induces cell fusion, electroporation on biological cells, including apoptosis. Apoptosis is expressed in a series of natural enzymatic reactions for the natural elimination of unhealthy, genetically damaged, or otherwise aberrant cells that are not needed or not advantageous to the well-being of the organism. Its markers involve cell shrinkage, activation of intracellular caspase proteases, externalization of phosphatidylserine at the plasma membrane, and fragmentation of DNA. Direct electric fields using direct current have been exploited recently to investigate its effects on tumor cells and tissues, but the mechanism of direct electric fields has not been exhibited clearly other than by electroosmosis or pH changes. Direct electric field induces apoptosis in tumor cells cultured and tumor tissues as indicated by cell shrinkage, DNA fragmentation and tumor suppression. In our experiment that direct electric field was applied to tumor tissues via two needle electrodes inserted into tumor tissue 5mm at distance in parallel, pH changes resulted from electrochemical reaction, exhibiting about pH 9.0, 1.83, 2.0 in the vicinity of cathodic and anodic electrode, and at their mid-point, respectively. DNA fragmentation of tumor tissues destructed by direct electric field was analyzed by Tunel assay by ApopTag technology. As a result of this analysis, it showed that apoptosis in tumor tissue destructed was increased up to 59.1normal(control) tissues, showing 41.1, 31.1cathodic tissues. In vitro cell survival was exhibited that it was decreased with enhancing electric current intensity in the same condition of electrical charge 5C having different time applied. We will show results of apoptosis analyzed by flow cytometry in vitro.

  2. Apoptosis Process in Mouse Leydig Cells during Postnatal Development

    NASA Astrophysics Data System (ADS)

    Salles Faria, Maria José; Simões, Zilá Paulino; Luz; Orive Lunardi, Laurelucia; Hartfelder, Klaus

    2003-02-01

    The development of Leydig cells in mammals has been widely described as a biphasic pattern with two temporally mature Leydig cell populations, fetal stage followed by the adult generation beginning at puberty. In the present study, mouse Leydig cells were examined for apoptosis during postnatal testis development using electron microscopy and in situ DNA fragmentation by terminal deoxynucleotidyl transferase staining (TdT). Both the morphological study and the DNA fragmentation analysis showed that cellular death by apoptosis did not occur in Leydig cells during the neonatal, prepubertal, puberty, and adult periods. From these results, we suggest that the remaining fetal Leydig cells in the neonatal testis are associated with the involution or degeneration processes. In contrast, in the prepubertal and puberty stages, fragmentation of apoptotic DNA was detected in germ cells present in some seminiferous tubules.

  3. Apoptosis of postovulatory cumulus granulosa cells of the rat.

    PubMed

    Szołtys, M; Tabarowski, Z; Pawlik, A

    2000-12-01

    The process of apoptosis in the postovulatory cumulus granulosa cells was investigated in pregnant rats. Mature female Wistar rats, exhibiting a regular 4-day oestrous cycle, were placed with males on the day of pro-oestrus. The following day, on which spermatozoa were found in vaginal smears, was designated day 1 of pregnancy. The animals were killed just before ovulation (24.00 hours), on days 1 (5.00, 11.00, and 18.00 hours), and 2 ( 11.00 hours) of pregnancy. Excised ovaries and oviducts were submitted to a routine histological procedure and paraplast sections were subjected to detection of apoptotic cells using the TUNEL method. The cumulus granulosa cells of preovulatory follicles (24.00 hours) were negative for apoptotic staining. However, 5 h later a positive staining was observed in the oviduct ampulla and included the cumulus granulosa cells lying in the peripheral parts of postovulatory cumuli oophori, and the oviductal epithelial cells of this region. On the evening of day 1 almost all cumulus granulosa cells showed strong immunostaining while on day 2 at 11.00 hours only immunonegative clusters of remnants of cumulus granulosa cells were present in the distended ampulla region, while naked, two or more cell embryos were present in the further parts of oviduct. These results indicate that in the rat apoptosis of cumulus granulosa cells starts shortly after ovulation in the peripheral region. Epithelial ampullary cells surrounding ovulated cumuli show a massive apoptosis. PMID:11131018

  4. BRMS1 regulates apoptosis in non-small cell lung cancer cells.

    PubMed

    You, Jijun; He, Xuejun; Ding, Haibing; Zhang, Tingrong

    2015-01-01

    Breast cancer metastasis suppressor 1 (BRMS1) was originally identified as a metastasis suppressor gene in human breast cancer. Previous studies have reported that loss of BRMS1 expression correlates with tumor progression, and poor prognosis in NSCLC. However, the role of BRMS1 in NSCLC is not fully understood. In this study, we found that expression of BRMS1 in A549 cells did not affect cell growth under normal culture conditions but sensitized cells to apoptosis induced by serum deprivation. Consistently, knockdown of endogenous BRMS1 expression in H1299 cells suppressed cell apoptosis. We identified that BRMS1 regulate apoptosis in NSCLC cells by modulating Stat3 activation. Taken together, our results show that BRMS1 sensitizes NSCLC cells to apoptosis through Stat3 signaling pathway, suggesting a potential role of BRMS1 in regulating NSCLC apoptosis and metastasis. PMID:25182004

  5. Diffusion-weighted MRI for imaging cell death after cytotoxic or apoptosis-inducing therapy

    PubMed Central

    Papaevangelou, E; Almeida, G S; Jamin, Y; Robinson, S P; deSouza, N M

    2015-01-01

    Background: Non-invasive serial imaging is desirable to detect processes such as necrotic and apoptotic cell death in cancer patients undergoing treatment. This study investigated the use of diffusion-weighted (DW-) magnetic resonance imaging (MRI) for imaging cell death induced by either a cytotoxic drug (irinotecan), or the apoptosis-inducing agent birinapant, in human tumour xenografts in vivo. Methods: Nude mice bearing human SW620 colon carcinoma xenografts were treated with vehicle, irinotecan (50 mg kg−1) or birinapant (30 mg kg−1) for up to 5 days. DW-MRI was performed prior to and on days 1, 3 and 5 during treatment. Assessment of tumour apoptosis and necrosis ex vivo was used to validate the imaging findings. Results: Both irinotecan and birinapant induced significant tumour growth delay. Irinotecan induced a small increase in the tumour apparent diffusion coefficient (ADC) after 1 day, with a 20 and 30% increase at days 3 and 5 respectively. ADC was unchanged in the vehicle- and birinapant-treated tumours despite a growth delay in the latter. Histological analysis showed that irinotecan increased necrosis at days 3 and 5, and induced apoptosis after 1 day, compared with vehicle. Birinapant induced apoptosis after day 3, but had no effect on tumour necrosis. Conclusions: Tumour ADC changes after irinotecan treatment were associated with the induction of a mixture of necrotic and apoptotic cell death, whereas induction of apoptosis alone with birinapant was not sufficient to induce changes in tissue microstructure that were detectable with DW-MRI. ADC is a useful non-invasive biomarker for early detection of response to cytotoxic drugs, but false negatives may arise while detecting apoptotic response to birinapant. PMID:25880014

  6. Intravenous immunoglobulin replacement therapy in common variable immunodeficiency induces B cell depletion through differentiation into apoptosis-prone CD21(low) B cells.

    PubMed

    Mitrevski, Milica; Marrapodi, Ramona; Camponeschi, Alessandro; Lazzeri, Cristina; Todi, Laura; Quinti, Isabella; Fiorilli, Massimo; Visentini, Marcella

    2014-12-01

    Intravenous immunoglobulin (IVIG), besides its use as replacement therapy in patients with antibody deficiencies, is broadly used as an immunomodulatory agent for the treatment of autoimmune and inflammatory disorders. The mechanisms of action of IVIG include Fc receptor blockade, inhibition of cytokines and growth factors, modulation of macrophages and dendritic cells, enhancement of regulatory T cells, and modulation of B cells through the FcγRIIB receptor and CD22. Recent studies suggest that in vitro exposure of human B cells to IVIG determines functional changes reminiscent of anergy and that IVIG treatment of patients with common variable immunodeficiency (CVID) induces in B cells ERK activation, a feature of anergy. Here, we show that IVIG therapy drives the B cells of patients with CVID to down-regulate CD21 expression and to assume the peculiar phenotype of the anergic-like, apoptosis-prone CD21(low) B cells that are spontaneously expanded in a subset of CVID and in some other immunological disorders. The CD21(low) B cells newly generated after IVIG infusion undergo spontaneous apoptosis upon in vitro culture. Furthermore, IVIG infusion is rapidly followed by a significant, although discrete, decrease in the number of circulating B cells, but not of T cells or of natural killer cells. These findings suggest that IVIG therapy may constrain antibody responses by inducing B cell depletion through differentiation into CD21(low) B cells that undergo accelerated apoptosis. PMID:25407649

  7. Cimetidine induces apoptosis of human salivary gland tumor cells.

    PubMed

    Fukuda, Masakatsu; Tanaka, Shin; Suzuki, Seiji; Kusama, Kaoru; Kaneko, Tadayoshi; Sakashita, Hideaki

    2007-03-01

    It has been reported that cimetidine, a histamine type-2 receptor (H2R) antagonist, inhibits the growth of glandular tumors such as colorectal cancer. However, its effects against salivary gland tumors are still unknown. We demonstrated previously that human salivary gland tumor (HSG) cells spontaneously express the neural cell adhesion molecule (NCAM) and also that HSG cell proliferation could be controlled via a homophilic (NCAM-NCAM) binding mechanism and that NCAM may be associated with perineural invasion by malignant salivary gland tumors. In the present study, we investigated the effects of cimetidine via the expression of NCAM on tumor growth and perineural/neural invasion in salivary gland tumor cells. Expression of both NCAM mRNA and protein was found to decrease in a dose-dependent manner upon treatment with cimetidine for 24 h. The MTT assay and confocal laser microscopy clearly showed that HSG cells underwent apoptosis after treatment with cimetidine. Activation of caspases 3, 7, 8 and 9 was observed in HSG cells after cimetidine treatment, thus confirming that the apoptosis was induced by the activated caspases. Apaf-1 activity was also detected in HSG cells in a dose-dependent manner after treatment with cimetidine. We also found that the cimetidine-mediated down-regulation of NCAM expression in HSG cells did not occur via blocking of the histamine receptor, even though H2R expression was observed on HSG cells, as two other H2R antagonists, famotidine and ranitidine, did not show similar effects. We demonstrated for the first time that cimetidine can induce significant apoptosis of salivary gland tumor cells, which express NCAM, at least in part by down-regulation of NCAM expression on the cells. These findings suggest that the growth, development and perineural/neural invasion of salivary gland tumor cells can be blocked by cimetidine administration through down-regulation of NCAM expression, as well as induction of apoptosis. PMID:17273750

  8. Retinal Endothelial Cell Apoptosis Stimulates Recruitment of Endothelial Progenitor Cells

    PubMed Central

    Bhatwadekar, Ashay D.; Glenn, Josephine V.; Curtis, Tim M.; Grant, Maria B.; Stitt, Alan W.; Gardiner, Tom A.

    2013-01-01

    Purpose Bone marrow–derived endothelial progenitor cells (EPCs) contribute to vascular repair although it is uncertain how local endothelial cell apoptosis influences their reparative function. This study was conducted to determine how the presence of apoptotic bodies at sites of endothelial damage may influence participation of EPCs in retinal microvascular repair. Methods Microlesions of apoptotic cell death were created in monolayers of retinal microvascular endothelial cells (RMECs) by using the photodynamic drug verteporfin. The adhesion of early-EPCs to these lesions was studied before detachment of the apoptotic cells or after their removal from the wound site. Apoptotic bodies were fed to normal RMECs and mRNA levels for adhesion molecules were analyzed. Results Endothelial lesions where apoptotic bodies were left attached at the wound site showed a fivefold enhancement in EPC recruitment (P < 0.05) compared with lesions where the apoptotic cells had been removed. In intact RMEC monolayers exposed to apoptotic bodies, expression of ICAM, VCAM, and E-selectin was upregulated by 5- to 15-fold (P < 0.05– 0.001). EPCs showed a characteristic chemotactic response (P < 0.05) to conditioned medium obtained from apoptotic bodies, whereas analysis of the medium showed significantly increased levels of VEGF, IL-8, IL-6, and TNF-α when compared to control medium; SDF-1 remained unchanged. Conclusions The data indicate that apoptotic bodies derived from retinal capillary endothelium mediate release of proangiogenic cytokines and chemokines and induce adhesion molecule expression in a manner that facilitates EPC recruitment. PMID:19474402

  9. Signaling through C/EBP homologous protein and death receptor 5 and calpain activation differentially regulate THP-1 cell maturation-dependent apoptosis induced by Shiga toxin type 1.

    PubMed

    Lee, Moo-Seung; Cherla, Rama P; Lentz, Erin K; Leyva-Illades, Dinorah; Tesh, Vernon L

    2010-08-01

    Shiga toxins (Stxs) induce apoptosis via activation of the intrinsic and extrinsic pathways in many cell types. Toxin-mediated activation of the endoplasmic reticulum (ER) stress response was shown to be instrumental in initiating apoptosis in THP-1 myeloid leukemia cells. THP-1 cells responded to Shiga toxin type 1 (Stx1) in a cell maturation-dependent manner, undergoing rapid apoptosis in the undifferentiated state but reduced and delayed apoptosis in differentiated cells. The onset of apoptosis was associated with calpain activation and changes in expression of C/EBP homologous protein (CHOP), Bcl-2 family members, and death receptor 5 (DR5). Ligation of DR5 by tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) activates the extrinsic pathway of apoptosis. We show here that expression of TRAIL and DR5 is increased by Stx1 treatment. Addition of exogenous TRAIL enhances, and anti-TRAIL antibodies inhibit, Stx1-induced apoptosis of THP-1 cells. Silencing of CHOP or DR5 expression selectively prevented caspase activation, loss of mitochondrial membrane potential, and Stx1-induced apoptosis of macrophage-like THP-1 cells. In contrast, the rapid kinetics of apoptosis induction in monocytic THP-1 cells correlated with rates of calpain cleavage. The results suggest that CHOP-DR5 signaling and calpain activation differentially contribute to cell maturation-dependent Stx1-induced apoptosis. Inhibition of these signaling pathways may protect cells from Stx cytotoxicity. PMID:20515924

  10. Infrasound sensitizes human glioblastoma cells to cisplatin-induced apoptosis.

    PubMed

    Rachlin, Kenneth; Moore, Dan H; Yount, Garret

    2013-11-01

    The development of nontoxic agents that can selectively enhance the cytotoxicity of chemotherapy is an important aim in oncology. This study evaluates the ability of infrasound exposure to sensitize glioblastoma cells to cisplatin-induced apoptosis. The infrasound was delivered using a device designed to replicate the unique infrasound emissions measured during external Qigong treatments. Human glioblastoma cell lines harboring wild-type p53 (U87) or mutant p53 (U251, SF210, and SF188) were treated in culture with cisplatin, infrasound emissions, or the combination of the 2 agents. Induction of apoptosis was quantified after 24 hours by flow cytometry following annexin V/propidium iodide staining. Infrasound emissions alone, delivered at moderate levels (~10 mPa) with dynamic frequency content (7-13 Hz), did not induce apoptosis, yet combining infrasound with cisplatin augmented the induction of apoptosis by cisplatin in all the 4 cell lines (P < .05). Increased cellular uptake of the fluorophore calcein associated with infrasound exposure was quantified by fluorescence microscopy as well as flow cytometry, demonstrating increased cell membrane permeability. The 4 cell lines differed in the degree to which infrasound exposure increased calcein uptake, and these differences were predictive of the extent to which infrasound enhanced cisplatin-induced apoptosis. When exposed to specific frequencies, membrane permeabilization also appeared to be differentially responsive for each cell line, suggesting the potential for selective targeting of tissue types using isolated infrasonic frequencies. Additionally, the pressure amplitudes used in this study were several orders of magnitude less than those used in similar studies involving ultrasound and shock waves. The results of this study provide support for using infrasound to enhance the chemotherapeutic effects of cisplatin in a clinical setting. PMID:23165942

  11. Capsaicin induces apoptosis in PC12 cells through ER stress.

    PubMed

    Krizanova, Olga; Steliarova, Iveta; Csaderova, Lucia; Pastorek, Michal; Hudecova, Sona

    2014-02-01

    Capsaicin, the pungent agent in chili peppers, has been shown to act as a tumor-suppressor in cancer. In our previous study, capsaicin was shown to induce apoptosis in the rat pheochromocytoma cell line (PC12 cells). Thus, the aim of the present study was to determine the potential mechanism by which capsaicin induces apoptosis. We treated PC12 cells with 50, 100 and 500 µM capsaicin and measured the reticular calcium content and expression of the reticular calcium transport systems. These results were correlated with endoplasmic reticulum (ER) stress markers CHOP, ATF4 and X-box binding protein 1 (XBP1), as well as with apoptosis induction. We observed that capsaicin decreased reticular calcium in a concentration-dependent manner. Simultaneously, expression levels of the sarco/endoplasmic reticulum pump and ryanodin receptor of type 2 were modified. These changes were accompanied by increased ER stress, as documented by increased stress markers. Thus, from these results we propose that in PC12 cells capsaicin induces apoptosis through increased ER stress. PMID:24337105

  12. Tocilizumab unmasks a stage-dependent interleukin-6 component in statin-induced apoptosis of metastatic melanoma cells.

    PubMed

    Minichsdorfer, Christoph; Wasinger, Christine; Sieczkowski, Evelyn; Atil, Bihter; Hohenegger, Martin

    2015-08-01

    The interleukin (IL)-6 inhibits the growth of early-stage melanoma cells, but not metastatic cells. Metastatic melanoma cells are susceptible to statin-induced apoptosis, but this is not clear for early-stage melanoma cells. This study aimed to investigate the IL-6 susceptibility of melanoma cells from different stages in the presence of simvastatin to overcome loss of growth arrest. ELISA was used to detect secreted IL-6 in human melanoma cells. The effects of IL-6 were measured by western blots for STAT3 and Bcl-2 family proteins. Apoptosis and proliferation were measured by caspase 3 activity, Annexin V staining, cell cycle analysis, and a wound-healing assay. Human metastatic melanoma cells A375 and 518A2 secrete high amounts of IL-6, in contrast to early-stage WM35 cells. Canonical IL-6 signaling is intact in these cells, documented by transient phosphorylation of STAT3. Although WM35 cells are highly resistant to simvastatin-induced apoptosis, coadministration with IL-6 enhanced the susceptibility to undergo apoptosis. This proapoptotic effect of IL-6 might be explained by a downregulation of Bcl-XL, observed only in WM35 cells. Furthermore, the IL-6 receptor blocking antibody tocilizumab was coadministered and unmasked an IL-6-sensitive proportion in the simvastatin-induced caspase 3 activity of metastatic melanoma cells. These results confirm that simvastatin facilitates apoptosis in combination with IL-6. Although endogenous IL-6 secretion is sufficient in metastatic melanoma cells, exogenously added IL-6 is needed for WM35 cells. This effect may explain the failure of simvastatin to reduce melanoma incidence in clinical trials and meta-analyses. PMID:26020489

  13. Cytotoxicity and apoptosis induced by nanobacteria in human breast cancer cells

    PubMed Central

    Zhang, Ming-jun; Liu, Sheng-nan; Xu, Ge; Guo, Ya-nan; Fu, Jian-nan; Zhang, De-chun

    2014-01-01

    Background The existing evidence that nanobacteria (NB) are closely associated with human disease is overwhelming. However, their potential toxicity against cancer cells has not yet been reported. The objective of this study was to investigate the cytotoxic effects of NB and nanohydroxyapatites (nHAPs) against human breast cancer cells and to elucidate the mechanisms of action underlying their cytotoxicity. Methodology/principal findings NB were isolated from calcified placental tissue, and nHAPs were artificially synthesized. The viability of the MDA-MB-231 human breast cancer cell line was tested by using the Kit-8 cell counting kit assay. Apoptosis was examined by transmission electron microscopy and flow cytometry. The endocytosis of NB and nHAPs by MDA-MB-231 cells was initially confirmed by microscopy. Although both NB and nHAPs significantly decreased MDA-MB-231 cell viability and increased the population of apoptotic cells, NB were more potent than nHAPs. After 72 hours, NB also caused ultrastructural changes typical of apoptosis, such as chromatin condensation, nuclear fragmentation, nuclear dissolution, mitochondrial swelling, and the formation of apoptotic bodies. Conclusion/significance In MDA-MB-231 human breast cancer cells, NB and nHAPs exerted cytotoxic effects that were associated with the induction of apoptosis. The effects exerted by NB were more potent than those induced by nHAPs. NB cytotoxicity probably emerged from toxic metabolites or protein components, rather than merely the hydroxyapatite shells. NB divided during culturing, and similar to cells undergoing binary fission, many NB particles were observed in culture by transmission electron microscopy, suggesting they are live microorganisms. PMID:24403832

  14. Ouabain Enhances ADPKD Cell Apoptosis via the Intrinsic Pathway

    PubMed Central

    Venugopal, Jessica; Blanco, Gustavo

    2016-01-01

    Progression of autosomal dominant polycystic kidney disease (ADPKD) is highly influenced by factors circulating in blood. We have shown that the hormone ouabain enhances several characteristics of the ADPKD cystic phenotype, including the rate of cell proliferation, fluid secretion and the capacity of the cells to form cysts. In this work, we found that physiological levels of ouabain (3 nM) also promote programmed cell death of renal epithelial cells obtained from kidney cysts of patients with ADPKD (ADPKD cells). This was determined by Alexa Fluor 488 labeled-Annexin-V staining and TUNEL assay, both biochemical markers of apoptosis. Ouabain-induced apoptosis also takes place when ADPKD cell growth is blocked; suggesting that the effect is not secondary to the stimulatory actions of ouabain on cell proliferation. Ouabain alters the expression of BCL family of proteins, reducing BCL-2 and increasing BAX expression levels, anti- and pro-apoptotic mediators respectively. In addition, ouabain caused the release of cytochrome c from mitochondria. Moreover, ouabain activates caspase-3, a key “executioner” caspase in the cell apoptotic pathway, but did not affect caspase-8. This suggests that ouabain triggers ADPKD cell apoptosis by stimulating the intrinsic, but not the extrinsic pathway of programmed cell death. The apoptotic effects of ouabain are specific for ADPKD cells and do not occur in normal human kidney cells (NHK cells). Taken together with our previous observations, these results show that ouabain causes an imbalance in cell growth/death, to favor growth of the cystic cells. This event, characteristic of ADPKD, further suggests the importance of ouabain as a circulating factor that promotes ADPKD progression. PMID:27047392

  15. Ouabain Enhances ADPKD Cell Apoptosis via the Intrinsic Pathway.

    PubMed

    Venugopal, Jessica; Blanco, Gustavo

    2016-01-01

    Progression of autosomal dominant polycystic kidney disease (ADPKD) is highly influenced by factors circulating in blood. We have shown that the hormone ouabain enhances several characteristics of the ADPKD cystic phenotype, including the rate of cell proliferation, fluid secretion and the capacity of the cells to form cysts. In this work, we found that physiological levels of ouabain (3 nM) also promote programmed cell death of renal epithelial cells obtained from kidney cysts of patients with ADPKD (ADPKD cells). This was determined by Alexa Fluor 488 labeled-Annexin-V staining and TUNEL assay, both biochemical markers of apoptosis. Ouabain-induced apoptosis also takes place when ADPKD cell growth is blocked; suggesting that the effect is not secondary to the stimulatory actions of ouabain on cell proliferation. Ouabain alters the expression of BCL family of proteins, reducing BCL-2 and increasing BAX expression levels, anti- and pro-apoptotic mediators respectively. In addition, ouabain caused the release of cytochrome c from mitochondria. Moreover, ouabain activates caspase-3, a key "executioner" caspase in the cell apoptotic pathway, but did not affect caspase-8. This suggests that ouabain triggers ADPKD cell apoptosis by stimulating the intrinsic, but not the extrinsic pathway of programmed cell death. The apoptotic effects of ouabain are specific for ADPKD cells and do not occur in normal human kidney cells (NHK cells). Taken together with our previous observations, these results show that ouabain causes an imbalance in cell growth/death, to favor growth of the cystic cells. This event, characteristic of ADPKD, further suggests the importance of ouabain as a circulating factor that promotes ADPKD progression. PMID:27047392

  16. Minerval induces apoptosis in Jurkat and other cancer cells

    PubMed Central

    Llado, Victoria; Gutierrez, Antonio; Martínez, Jordi; Casas, Jesús; Terés, Silvia; Higuera, Mónica; Galmés, Antonio; Saus, Carles; Besalduch, Joan; Busquets, Xavier; Escribá, Pablo V

    2010-01-01

    Abstract Minerval is an oleic acid synthetic analogue that impairs lung cancer (A549) cell proliferation upon modulation of the plasma membrane lipid structure and subsequent regulation of protein kinase C localization and activity. However, this mechanism does not fully explain the regression of tumours induced by this drug in animal models of cancer. Here we show that Minerval also induced apoptosis in Jurkat T-lymphoblastic leukaemia and other cancer cells. Minerval inhibited proliferation of Jurkat cells, concomitant with a decrease of cyclin D3 and cdk2 (cyclin-dependent kinase2). In addition, the changes that induced on Jurkat cell membrane organization caused clustering (capping) of the death receptor Fas (CD95), caspase-8 activation and initiation of the extrinsic apoptosis pathway, which finally resulted in programmed cell death. The present results suggest that the intrinsic pathway (associated with caspase-9 function) was activated downstream by caspase-8. In a xenograft model of human leukaemia, Minerval also inhibited tumour progression and induced tumour cell death. Studies carried out in a wide variety of cancer cell types demonstrated that apoptosis was the main molecular mechanism triggered by Minerval. This is the first report on the pro-apoptotic activity of Minerval, and in part explains the effectiveness of this non-toxic anticancer drug and its wide spectrum against different types of cancer. PMID:19413889

  17. Mitotic arrest-associated apoptosis induced by sodium arsenite in A375 melanoma cells is BUBR1-dependent

    SciTech Connect

    McNeely, Samuel C.; Taylor, B. Frazier; States, J. Christopher

    2008-08-15

    A375 human malignant melanoma cells undergo mitotic arrest-associated apoptosis when treated with pharmacological concentrations of sodium arsenite, a chemotherapeutic for acute promyelocytic leukemia. Our previous studies indicated that decreased arsenite sensitivity correlated with reduced mitotic spindle checkpoint function and reduced expression of the checkpoint protein BUBR1. In the current study, arsenite induced securin and cyclin B stabilization, BUBR1 phosphorylation, and spindle checkpoint activation. Arsenite also increased activating cyclin dependent kinase 1 (CDK1) Thr{sup 161} phosphorylation but decreased inhibitory Tyr15 phosphorylation. Mitotic arrest resulted in apoptosis as indicated by colocalization of mitotic phospho-Histone H3 with active caspase 3. Apoptosis was associated with BCL-2 Ser70 phosphorylation. Inhibition of CDK1 with roscovitine in arsenite-treated mitotic cells inhibited spindle checkpoint maintenance as inferred from reduced BUBR1 phosphorylation, reduced cyclin B expression, and diminution of mitotic index. Roscovitine also reduced BCL-2 Ser70 phosphorylation and protected against apoptosis, suggesting mitotic arrest caused by hyperactivation of CDK1 directly or indirectly leads to BCL-2 phosphorylation and apoptosis. In addition, suppression of BUBR1 with siRNA prevented arsenite-induced mitotic arrest and apoptosis. These findings provide insight into the mechanism of arsenic's chemotherapeutic action and indicate a functional spindle checkpoint may be required for arsenic-sensitivity.

  18. Overexpression of DDB2 enhances the sensitivity of human ovarian cancer cells to cisplatin by augmenting cellular apoptosis

    PubMed Central

    Barakat, Bassant M.; Wang, Qi-En; Han, Chunhua; Milum, Keisha; Yin, De-Tao; Zhao, Qun; Wani, Gulzar; Arafa, El-Shaimaa A.; El-Mahdy, Mohamed A.; Wani, Altaf A.

    2014-01-01

    Cisplatin is one of the most widely used anticancer agents, displaying activity against a wide variety of tumors. However, development of drug resistance presents a challenging barrier to successful cancer treatment by cisplatin. To understand the mechanism of cisplatin resistance, we investigated the role of damaged DNA binding protein complex subunit 2 (DDB2) in cisplatin-induced cytotoxicity and apoptosis. We show that DDB2 is not required for the repair of cisplatin-induced DNA damage, but can be induced by cisplatin treatment. DDB2-deficient noncancer cells exhibit enhanced resistance to cell growth inhibition and apoptosis induced by cisplatin than cells with fully restored DDB2 function. Moreover, DDB2 expression in cisplatin-resistant ovarian cancer cell line CP70 and MCP2 was lower than their cisplatin-sensitive parental A2780 cells. Overexpression of DDB2 sensitized CP70 cells to cisplatin-induced cytotoxicity and apoptosis via activation of the caspase pathway and downregulation of antiapoptotic Bcl-2 protein. Further analysis indicates that the overexpression of DDB2 in CP70 cells downregulates Bcl-2 expression through decreasing Bcl-2 mRNA level. These results suggest that ovarian cancer cells containing high level of DDB2 become susceptible to cisplatin by undergoing enhanced apoptosis. PMID:20013802

  19. Epithelial cell apoptosis causes acute lung injury masquerading as emphysema.

    PubMed

    Mouded, Majd; Egea, Eduardo E; Brown, Matthew J; Hanlon, Shane M; Houghton, A McGarry; Tsai, Larry W; Ingenito, Edward P; Shapiro, Steven D

    2009-10-01

    Theories of emphysema traditionally revolved around proteolytic destruction of extracellular matrix. Models have recently been developed that show airspace enlargement with the induction of pulmonary cell apoptosis. The purpose of this study was to determine the mechanism by which a model of epithelial cell apoptosis caused airspace enlargement. Mice were treated with either intratracheal microcystin (MC) to induce apoptosis, intratracheal porcine pancreatic elastase (PPE), or their respective vehicles. Mice from all groups were inflated and morphometry was measured at various time points. Physiology measurements were performed for airway resistance, tissue elastance, and lung volumes. The groups were further analyzed by air-saline quasistatic measurements, surfactant staining, and surfactant functional studies. Mice treated with MC showed evidence of reversible airspace enlargement. In contrast, PPE-treated mice showed irreversible airspace enlargement. The airspace enlargement in MC-treated mice was associated with an increase in elastic recoil due to an increase in alveolar surface tension. PPE-treated mice showed a loss of lung elastic recoil and normal alveolar surface tension, a pattern more consistent with human emphysema. Airspace enlargement that occurs with the MC model of pulmonary epithelial cell apoptosis displays physiology distinct from human emphysema. Reversibility, restrictive physiology due to changes in surface tension, and alveolar enlargement associated with heterogeneous alveolar collapse are most consistent with a mild acute lung injury. Inflation near total lung capacity gives the appearance of enlarged alveoli as neighboring collapsed alveoli exert tethering forces. PMID:19188661

  20. miR-23a and miR-27a promote human granulosa cell apoptosis by targeting SMAD5.

    PubMed

    Nie, Mingyue; Yu, Song; Peng, Sha; Fang, Ying; Wang, Hongmei; Yang, Xiaokui

    2015-10-01

    In mammals, follicular atresia can be partially triggered by granulosa cell apoptosis. However, very little is known about the functions of miRNAs in granulosa cell apoptosis. We previously reported that hsa-mir-23a (miR-23a) and hsa-mir-27a (miR-27a) were highly expressed in the plasma of patients with premature ovarian failure, but the action of these two miRNAs in follicular development was unclear. In this study, we explored the roles of miR-23a and miR-27a in the granulosa cells of women undergoing in vitro fertilization/embryo transfer. Using Hoechst staining, we found that miR-23a and miR-27a promoted apoptosis in human granulosa cells. In addition, the Western blotting results suggested that the miR-23a/miR-27a-mediated apoptosis occurred via the FasL-Fas pathway. Based on the results of a luciferase-reporter assay and quantitative RT-PCR and Western blotting analyses, we found that SMAD5 is a target gene of both miR-23a and miR-27a. Furthermore, knocking down SMAD5 expression increased the rate of apoptosis, as well as the levels of Fas, FasL, cleaved caspase-8, and cleaved caspase-3 protein. Taken together, these data suggest that miR-23a and miR-27a target SMAD5 and regulate apoptosis in human granulosa cells via the FasL-Fas pathway. These findings provide an improved understanding of the mechanisms underlying granulosa cell apoptosis, which could potentially be used for future clinical applications. PMID:26400397

  1. Coxsackievirus A16 Infection Induces Neural Cell and Non-Neural Cell Apoptosis In Vitro

    PubMed Central

    Liu, Li; Wei, Zhenhong; Ehrlich, Elana S.; Liu, Guanchen; Li, Jingliang; Liu, Xin; Wang, Hong; Yu, Xiao-fang; Zhang, Wenyan

    2014-01-01

    Coxsackievirus A16 (CA16) is one of the main causative pathogens of hand, foot and mouth disease (HFMD). Viral replication typically results in host cell apoptosis. Although CA16 infection has been reported to induce apoptosis in the human rhabdomyosarcoma (RD) cell line, it remains unclear whether CA16 induces apoptosis in diverse cell types, especially neural cells which have important clinical significance. In the current study, CA16 infection was found to induce similar apoptotic responses in both neural cells and non-neural cells in vitro, including nuclear fragmentation, DNA fragmentation and phosphatidylserine translocation. CA16 generally is not known to lead to serious neurological symptoms in vivo. In order to further clarify the correlation between clinical symptoms and cell apoptosis, two CA16 strains from patients with different clinical features were investigated. The results showed that both CA16 strains with or without neurological symptoms in infected patients led to neural and muscle cell apoptosis. Furthermore, mechanistic studies showed that CA16 infection induced apoptosis through the same mechanism in both neural and non-neural cells, namely via activation of both the mitochondrial (intrinsic) pathway-related caspase 9 protein and the Fas death receptor (extrinsic) pathway-related caspase 8 protein. Understanding the mechanisms by which CA16 infection induces apoptosis in both neural and non-neural cells will facilitate a better understanding of CA16 pathogenesis. PMID:25350381

  2. A Ribonuclease Isolated from Wild Ganoderma Lucidum Suppressed Autophagy and Triggered Apoptosis in Colorectal Cancer Cells.

    PubMed

    Dan, Xiuli; Liu, Wenlong; Wong, Jack H; Ng, Tzi B

    2016-01-01

    The mushroom Ganoderma lucidum (G. lucidum) has been consumed in China as a medicine for promoting health and longevity for thousands of years. Due to its paramount and multiple pharmaceutical effects, G. lucidum has received considerable attention from researchers and its chemical constituents as well as their respective functions were gradually unveiled by using modern research methods. Herein, we reported the isolation of a protein (Ganoderma lucidum ribonuclease, GLR) with anti-colorectal cancer activities from G. lucidum. This protein is a 17.4-kDa RNA degrading enzyme (ribonuclease) and was purified by using liquid chromatography procedures. GLR manifested potent anti-proliferative and anti-colony formation activities on HT29 and HCT116 colorectal cancer cells by inducing cell cycle arrest in G1 phase through the regulation of cyclin D1 and P53 expression. GLR was demonstrated to induce cell apoptosis in HCT116 cells by activating unfolded protein response and caspase-9 regulated pathways. Besides, the ability to undergo autophagy which is a stress adaption mechanism to cope with metabolic crisis was significantly suppressed by GLR treatment in HCT116 cells. The activation of apoptosis in GLR-treated HT29 cells was, however, independent of caspase-9 and the suppression of autophagy was also relatively minor. Thus the apoptosis of HT29 cells triggered by GLR was much milder than that in HCT116 cells. Our findings show that the RNase from G. lucidum may be one of the bioactive components that contribute to the anti-colorectal cancer activity of G. lucidum. PMID:27504094

  3. A Ribonuclease Isolated from Wild Ganoderma Lucidum Suppressed Autophagy and Triggered Apoptosis in Colorectal Cancer Cells

    PubMed Central

    Dan, Xiuli; Liu, Wenlong; Wong, Jack H.; Ng, Tzi B.

    2016-01-01

    The mushroom Ganoderma lucidum (G. lucidum) has been consumed in China as a medicine for promoting health and longevity for thousands of years. Due to its paramount and multiple pharmaceutical effects, G. lucidum has received considerable attention from researchers and its chemical constituents as well as their respective functions were gradually unveiled by using modern research methods. Herein, we reported the isolation of a protein (Ganoderma lucidum ribonuclease, GLR) with anti-colorectal cancer activities from G. lucidum. This protein is a 17.4-kDa RNA degrading enzyme (ribonuclease) and was purified by using liquid chromatography procedures. GLR manifested potent anti-proliferative and anti-colony formation activities on HT29 and HCT116 colorectal cancer cells by inducing cell cycle arrest in G1 phase through the regulation of cyclin D1 and P53 expression. GLR was demonstrated to induce cell apoptosis in HCT116 cells by activating unfolded protein response and caspase-9 regulated pathways. Besides, the ability to undergo autophagy which is a stress adaption mechanism to cope with metabolic crisis was significantly suppressed by GLR treatment in HCT116 cells. The activation of apoptosis in GLR-treated HT29 cells was, however, independent of caspase-9 and the suppression of autophagy was also relatively minor. Thus the apoptosis of HT29 cells triggered by GLR was much milder than that in HCT116 cells. Our findings show that the RNase from G. lucidum may be one of the bioactive components that contribute to the anti-colorectal cancer activity of G. lucidum. PMID:27504094

  4. Apoptosis as the focus of an authentic research experience in a cell physiology laboratory.

    PubMed

    Byrd, Shere K

    2016-06-01

    Curriculum-embedded independent research is a high-impact teaching practice that has been shown to increase student engagement and learning. This article describes a multiweek laboratory project for an upper-division undergraduate cell physiology laboratory using apoptosis via the mitochondrial pathway as the overarching theme. Students did literature research on apoptotic agents that acted via the mitochondrial pathway. Compounds ranged from natural products such as curcumin to synthetic compounds such as etoposide. Groups of two to three students planned a series of experiments using one of three cultured cell lines that required them to 1) learn to culture cells; 2) determine treatment conditions, including apoptotic agent solubility and concentration ranges that had been reported in the literature; 3) choose two methods to validate/quantify apoptotic capacity of the reagent; and 4) attempt to "rescue" cells from undergoing apoptosis using one of several available compounds/methods. In essence, given some reagent and equipment constraints, students designed an independent experiment to highlight the effects of different apoptotic agents on cells in culture. Students presented their experimental designs as in a laboratory group meeting and their final findings as a classroom "symposium." This exercise can be adapted to many different types of laboratories with greater or lesser equipment and instrumentation constraints, incorporates several core cell physiology methods, and encourages key experimental design and critical thinking components of independent research. PMID:27231261

  5. Fractionated stem cell infusions for patients with plasma cell myeloma undergoing autologous hematopoietic cell transplantation.

    PubMed

    Landau, Heather; Wood, Kevin; Chung, David J; Koehne, Guenther; Lendvai, Nikoletta; Hassoun, Hani; Lesokhin, Alexander; Hoover, Elizabeth; Zheng, Junting; Devlin, Sean M; Giralt, Sergio

    2016-08-01

    We conducted a phase II trial investigating the impact of fractionated hematopoietic cell infusions on engraftment kinetics and symptom burden in patients with plasma cell myeloma (PCM) undergoing autologous hematopoietic cell transplant (AHCT). We hypothesized that multiple hematopoietic cell infusions would reduce duration of neutropenia and enhance immune recovery resulting in a better tolerated procedure. Twenty-six patients received high-dose melphalan followed by multiple cell infusions (Days 0, +2, +4, +6) and were compared to PCM patients (N = 77) who received high-dose melphalan and a single infusion (Day 0) (concurrent control group). The primary endpoint was number of days with ANC <500K/mcL. Symptom burden was assessed using the MSK-modified MD Anderson Symptom Inventory. Median duration of neutropenia was similar in study (4 days, range 3-5) and control patients (4 days, range 3-9) (p = 0.654). There was no significant difference in the number of red cell or platelet transfusions, days of fever, diarrhea, antibiotics, number of documented infections, or length of admission. Symptom burden surveys showed that AHCT was well-tolerated in both study and control patients. We conclude that fractionated stem cell infusions following high-dose melphalan do not enhance engraftment kinetics or significantly alter patients' clinical course following AHCT in PCM. PMID:26758672

  6. TUCAN/CARDINAL/CARD8 and apoptosis resistance in non-small cell lung cancer cells

    PubMed Central

    Checinska, Agnieszka; Giaccone, Giuseppe; Hoogeland, Bas SJ; Ferreira, Carlos G; Rodriguez, Jose A; Kruyt, Frank AE

    2006-01-01

    Background Activation of caspase-9 in response to treatment with cytotoxic drugs is inhibited in NSCLC cells, which may contribute to the clinical resistance to chemotherapy shown in this type of tumor. The aim of the present study was to investigate the mechanism of caspase-9 inhibition, with a focus on a possible role of TUCAN as caspase-9 inhibitor and a determinant of chemosensitivity in NSCLC cells. Methods Caspase-9 processing and activation were investigated by Western blot and by measuring the cleavage of the fluorogenic substrate LEHD-AFC. Proteins interaction assays, and RNA interference in combination with cell viability and apoptosis assays were used to investigate the involvement of TUCAN in inhibition of caspase-9 and chemosensitivity NSCLC. Results Analysis of the components of the caspase-9 activation pathway in a panel of NSCLC and SCLC cells revealed no intrinsic defects. In fact, exogenously added cytochrome c and dATP triggered procaspase-9 cleavage and activation in lung cancer cell lysates, suggesting the presence of an inhibitor. The reported inhibitor of caspase-9, TUCAN, was exclusively expressed in NSCLC cells. However, interactions between TUCAN and procaspase-9 could not be demonstrated by any of the assays used. Furthermore, RNA interference-mediated down-regulation of TUCAN did not restore cisplatin-induced caspase-9 activation or affect cisplatin sensitivity in NSCLC cells. Conclusion These results indicate that procaspase-9 is functional and can undergo activation and full processing in lung cancer cell extracts in the presence of additional cytochrome c/dATP. However, the inhibitory protein TUCAN does not play a role in inhibition of procaspase-9 and in determining the sensitivity to cisplatin in NSCLC. PMID:16796750

  7. Implications of Sertoli cell induced germ cell apoptosis to testicular pathology

    PubMed Central

    Murphy, Caitlin J; Richburg, John H

    2014-01-01

    After exposure to toxicants, degenerating germ cells represents the most common testicular histopathological alteration, regardless of the mechanism of toxicity. Therefore, deciphering the primary toxicant cellular target and mechanism of action can be extremely difficult. However, most testicular toxicants display a cell-specific and a stage-specific pattern of damage, which is the best evidence for identifying the primary cellular target (i.e. germ cell, Sertoli cell, peritubular myoid cell, or Leydig cell). Some toxicant-induced Sertoli cell injury presents with germ cell apoptosis occurring primarily in spermatocytes in rats in stages XI-XIV, I and II. Although some toxicants result in spermatid degeneration and apoptosis, it is still unclear if spermatid apoptosis is a result of Sertoli cell-selective apoptosis or a direct effect of toxicants on spermatids, therefore if this is seen as the earliest change, one cannot infer the mechanism of apoptosis. This review summarizes some of the distinguishing features of Sertoli cell-induced germ cell apoptosis and the associated mechanisms of cell death to provide the toxicologist observing similar cell death, with evidence about a potential mode of action. PMID:26413394

  8. Wnt and the Cancer Niche: Paracrine Interactions with Gastrointestinal Cancer Cells Undergoing Asymmetric Cell Division

    PubMed Central

    Xin, Hong-Wu; Ambe, Chenwi M.; Ray, Satyajit; Kim, Bo-Kyu; Koizumi, Tomotake; Wiegand, Gordon W.; Hari, Danielle; Mullinax, John E.; Jaiswal, Kshama R.; Garfield, Susan H.; Stojadinovic, Alexander; Rudloff, Udo; Thorgeirsson, Snorri S.; Avital, Itzhak

    2013-01-01

    Objective: Stem-like cancer cells contribute to cancer initiation and maintenance. Stem cells can self-renew by asymmetric cell division (ACD). ACD with non-random chromosomal cosegregation (ACD-NRCC) is one possible self-renewal mechanism. There is a paucity of evidence supporting ACD-NRCC in human cancer. Our aim was to investigate ACD-NRCC and its potential interactions with the cancer niche (microenvironment) in gastrointestinal cancers. Design: We used DNA double and single labeling approaches with FACS to isolate live cells undergoing ACD-NRCC. Results: Gastrointestinal cancers contain rare subpopulations of cells capable of ACD-NRCC. ACD-NRCC was detected preferentially in subpopulations of cells previously suggested to be stem-like/tumor-initiating cancer cells. ACD-NRCC was independent of cell-to-cell contact, and was regulated by the cancer niche in a heat-sensitive paracrine fashion. Wnt pathway genes and proteins are differentially expressed in cells undergoing ACD-NRCC vs. symmetric cell division. Blocking the Wnt pathway with IWP2 (WNT antagonist) or siRNA-TCF4 resulted in suppression of ACD-NRCC. However, using a Wnt-agonist did not increase the relative proportion of cells undergoing ACD-NRCC. Conclusion: Gastrointestinal cancers contain subpopulations of cells capable of ACD-NRCC. Here we show for the first time that ACD-NRCC can be regulated by the Wnt pathway, and by the cancer niche in a paracrine fashion. However, whether ACD-NRCC is exclusively associated with stem-like cancer cells remains to be determined. Further study of these findings might generate novel insights into stem cell and cancer biology. Targeting the mechanism of ACD-NRCC might engender novel approaches for cancer therapy. PMID:23901343

  9. Pulse mode of laser photodynamic treatment induced cell apoptosis.

    PubMed

    Klimenko, Vladimir V; Knyazev, Nickolay A; Moiseenko, Fedor V; Rusanov, Anatoliy A; Bogdanov, Alexey A; Dubina, Michael V

    2016-03-01

    One of the factors limiting photodynamic therapy (PDT) is hypoxia in tumor cells during photodynamic action. PDT with pulse mode irradiation and appropriate irradiation parameters could be more effective in the singlet oxygen generation and tissue re-oxygenation than continuous wave (CW) mode. We theoretically demonstrate differences between the cumulative singlet oxygen concentration in PDT using pulse mode and CW mode of laser irradiation. In vitro experimental results show that photodynamic treatment with pulse mode irradiation has similar cytotoxicity to CW mode and induces mainly cell apoptosis, whereas CW mode induces necrotic cell death. We assume that the cumulative singlet oxygen concentration and the temporal distribution of singlet oxygen are important in photodynamic cytotoxicity and apoptosis initiation. We expect our research may improve irradiation protocols and photodynamic therapy efficiency. PMID:26790610

  10. Impact of simulated microgravity on microvascular endothelial cell apoptosis.

    PubMed

    Kang, Chun-Yan; Zou, Lin; Yuan, Ming; Wang, Yang; Li, Tian-Zhi; Zhang, Ye; Wang, Jun-Feng; Li, Yan; Deng, Xiao-Wei; Liu, Chang-Ting

    2011-09-01

    Cardiovascular deconditioning is known to occur in astronauts exposed to microgravity. Endothelial dysfunction at microcirculatory sites might contribute to cardiovascular deconditioning induced by weightlessness. Recent studies have reported changes in the morphology and gene expression of endothelial cells exposed to conditions of simulated microgravity. The present study was aimed at examining the effects of microgravity on the apoptosis of microvascular endothelial cells and the mechanism underlying these effects. We simulated a microgravity environment and found that microgravity induced microvascular endothelial cell apoptosis and that this effect was correlated with the downregulation of the PI3K/Akt pathway, increased expression of NF-κB, and depolymerization of F-actin. These findings may provide important insights into the origin of the adverse physiological changes occurring due to exposure to microgravity conditions. PMID:21287193

  11. Magnetic Fe₃O₄ nanoparticles and chemotherapy agents interact synergistically to induce apoptosis in lymphoma cells.

    PubMed

    Jing, Hongmei; Wang, Jing; Yang, Ping; Ke, Xiaoyan; Xia, Guohua; Chen, Baoan

    2010-01-01

    The purpose of this study was to investigate the potential effects of combination therapy using magnetic nanoparticles of Fe₃O₄ (MNP-Fe₃O₄) and chemotherapeutic drugs on lymphoma cells. Proliferation, inhibition, and viability of Raji cells were detected by MTT and trypan blue exclusion. The percentage of cells undergoing apoptosis was detected by flow cytometry using fluorescein isothiocyanate-annexin V and propidium iodide staining. p53 and nuclear factor-κB (NF-κB) protein levels were measured by Western blot. The results showed that proliferation of Raji cells was inhibited by adriamycin or daunorubicin in a dose-and time-dependent manner. Cell sensitivity was improved and the 50% inhibitory concentrations of adriamycin and daunorubicin decreased when combined with a MNP-Fe₃O₄ carrier. Interestingly, increased apoptosis in Raji lymphoma cells was accompanied by upregulation of p53 protein and downregulation of NF-κB protein. Furthermore, the combination of MNP-Fe₃O₄ with adriamycin or daunorubicin increased p53 protein levels and decreased NF-κB protein levels more than adriamycin or daunorubicin alone, indicating that MNP-Fe₃O₄ could enhance the effect of chemotherapeutic drugs on p53 and NF-κB. Similar results for cell apoptosis and protein expression were not observed for the groups treated with dexamethasone ± MNP-Fe₃O₄ (P > 0.05). These findings suggest a potential clinical application for MNP-Fe₃O₄ in combination with daunorubicin or adriamycin in the treatment of lymphoma. PMID:21187919

  12. Intracellular GTP level determines cell's fate toward differentiation and apoptosis

    SciTech Connect

    Meshkini, Azadeh; Yazdanparast, Razieh Nouri, Kazem

    2011-06-15

    Since the adequate supply of guanine nucleotides is vital for cellular activities, limitation of their syntheses would certainly result in modulation of cellular fate toward differentiation and apoptosis. The aim of this study was to set a correlation between the intracellular level of GTP and the induction of relevant signaling pathways involved in the cell's fate toward life or death. In that regard, we measured the GTP level among human leukemia K562 cells exposed to mycophenolic acid (MPA) or 3-hydrogenkwadaphnin (3-HK) as two potent inosine monophosphate dehydrogenase inhibitors. Our results supported the maturation of the cells when the intracellular GTP level was reduced by almost 30-40%. Under these conditions, 3-HK and/or MPA caused up-regulation of PKC{alpha} and PI3K/AKT pathways. Furthermore, co-treatment of cells with hypoxanthine plus 3-HK or MPA, which caused a reduction of about 60% in the intracellular GTP levels, led to apoptosis and activation of mitochondrial pathways through inverse regulation of Bcl-2/Bax expression and activation of caspase-3. Moreover, our results demonstrated that attenuation of GTP by almost 60% augmented the intracellular ROS and nuclear localization of p21 and subsequently led to cell death. These results suggest that two different threshold levels of GTP are needed for induction of differentiation and/or ROS-associated apoptosis. - Graphical abstract: Display Omitted

  13. TGFβ signaling promotes juvenile granulosa cell tumorigenesis by suppressing apoptosis.

    PubMed

    Mansouri-Attia, Nadéra; Tripurani, Swamy K; Gokul, Nisha; Piard, Hermann; Anderson, Matthew L; Eldin, Karen; Pangas, Stephanie A

    2014-11-01

    Molecular changes that give rise to granulosa cell tumors of the ovary are not well understood. Previously, we showed that deletion in granulosa cells of the bone morphogenetic protein receptor-signaling transcription factors, Smad1 and Smad5, causes development of metastatic granulosa cell tumors that phenocopy the juvenile form of granulosa cell tumors (JGCTs) in humans. The TGFβ-SMAD2/3 pathway is active in JGCTs, but its role is unknown. We tested the in vivo contribution of TGFβ-SMAD signaling to JGCT development by genetically deleting the common Smad4 from Smad1/5 double knockout mice. Smad1/5/4 triple knockout mice were sterile and had significantly increased survival and delayed tumor development compared to those for the Smad1/5 double knockout mice. The few tumors that did develop were smaller, showed no evidence of metastasis, and had increased apoptosis. In the human JGCT cell line COV434, TGFβ1 increased viability by inhibiting apoptosis through a TGFβ type I receptor-dependent repression of caspase activity and inhibition of poly(ADP-ribose) polymerase cleavage. These data support a tumor-promoting function of TGFβ in JGCTs through its ability to repress apoptosis. PMID:25243859

  14. Effect of the polyamine analogue N1,N11-diethylnorspermine on cell survival and susceptibility to apoptosis of human chondrocytes.

    PubMed

    Stanic, Ivana; Cetrullo, Silvia; Facchini, Annalisa; Stefanelli, Claudio; Borzì, Rosa Maria; Tantini, Benedetta; Guarnieri, Carlo; Caldarera, Claudio Marcello; Flamigni, Flavio

    2008-07-01

    Chondrocyte survival is closely linked to cartilage integrity, and forms of chondrocyte apoptotic death can contribute to cartilage degeneration in articular diseases. Since growing evidence also implicates polyamines in the control of cell death, we have been investigating the role of polyamine metabolism in chondrocyte survival and apoptosis. Treatment of human C-28/I2 chondrocytes with N(1),N(11)-diethylnorspermine (DENSPM), a polyamine analogue with clinical relevance as an experimental anticancer agent, inhibited polyamine biosynthesis and induced polyamine catabolism, thus rapidly depleting all main polyamines. DENSPM did not increase significantly caspase activity, but provoked a late cell death associated to DNA fragmentation. A short treatment with DENSPM did not reduce cell viability when given alone, but enhanced caspase-3 and -9 activation in chondrocytes exposed to tumor necrosis factor-alpha (TNF) and cycloheximide (CHX). A longer treatment with DENSPM however reduced caspase response to TNF plus CHX. Depletion of all polyamines obtained by specific inhibitors of polyamine biosynthesis did not cause cell death and contrasted apoptosis by decreasing caspase activities. In conclusion, following DENSPM treatment, C-28/I2 chondrocytes are initially sensitized to caspase 9-dependent apoptosis in the presence of TNF and CHX and may eventually undergo a late and mainly caspase-independent cell death in the absence of other stimuli. Moreover, these results indicate that a reduction of polyamine levels not only leads to inhibition of cell proliferation, but also of caspase-mediated pathways of chondrocyte apoptosis. PMID:18231987

  15. Liriodenine, an aporphine alkaloid from Enicosanthellum pulchrum, inhibits proliferation of human ovarian cancer cells through induction of apoptosis via the mitochondrial signaling pathway and blocking cell cycle progression.

    PubMed

    Nordin, Noraziah; Majid, Nazia Abdul; Hashim, Najihah Mohd; Rahman, Mashitoh Abd; Hassan, Zalila; Ali, Hapipah Mohd

    2015-01-01

    Enicosanthellum pulchrum is a tropical plant from Malaysia and belongs to the Annonaceae family. This plant is rich in isoquinoline alkaloids. In the present study, liriodenine, an isoquinoline alkaloid, was examined as a potential anticancer agent, particularly in ovarian cancer. Liriodenine was isolated by preparative high-performance liquid chromatography. Cell viability was performed to determine the cytotoxicity, whilst the detection of morphological changes was carried out by acridine orange/propidium iodide assay. Initial and late apoptosis was examined by Annexin V-fluorescein isothiocyanate and DNA laddering assays, respectively. The involvement of pathways was detected via caspase-3, caspase-8, and caspase-9 analyses. Confirmation of pathways was further performed in mitochondria using a cytotoxicity 3 assay. Apoptosis was confirmed at the protein level, including Bax, Bcl-2, and survivin, while interruption of the cell cycle was used for final validation of apoptosis. The result showed that liriodenine inhibits proliferation of CAOV-3 cells at 37.3 μM after 24 hours of exposure. Changes in cell morphology were detected by the presence of cell membrane blebbing, chromatin condensation, and formation of apoptotic bodies. Early apoptosis was observed by Annexin V-fluorescein isothiocyanate bound to the cell membrane as early as 24 hours. Liriodenine activated the intrinsic pathway by induction of caspase-3 and caspase-9. Involvement of the intrinsic pathway in the mitochondria could be seen, with a significant increase in mitochondrial permeability and cytochrome c release, whereas the mitochondrial membrane potential was decreased. DNA fragmentation occurred at 72 hours upon exposure to liriodenine. The presence of DNA fragmentation indicates the CAOV-3 cells undergo late apoptosis or final stage of apoptosis. Confirmation of apoptosis at the protein level showed overexpression of Bax and suppression of Bcl-2 and survivin. Liriodenine inhibits progression

  16. Liriodenine, an aporphine alkaloid from Enicosanthellum pulchrum, inhibits proliferation of human ovarian cancer cells through induction of apoptosis via the mitochondrial signaling pathway and blocking cell cycle progression

    PubMed Central

    Nordin, Noraziah; Majid, Nazia Abdul; Hashim, Najihah Mohd; Rahman, Mashitoh Abd; Hassan, Zalila; Ali, Hapipah Mohd

    2015-01-01

    Enicosanthellum pulchrum is a tropical plant from Malaysia and belongs to the Annonaceae family. This plant is rich in isoquinoline alkaloids. In the present study, liriodenine, an isoquinoline alkaloid, was examined as a potential anticancer agent, particularly in ovarian cancer. Liriodenine was isolated by preparative high-performance liquid chromatography. Cell viability was performed to determine the cytotoxicity, whilst the detection of morphological changes was carried out by acridine orange/propidium iodide assay. Initial and late apoptosis was examined by Annexin V-fluorescein isothiocyanate and DNA laddering assays, respectively. The involvement of pathways was detected via caspase-3, caspase-8, and caspase-9 analyses. Confirmation of pathways was further performed in mitochondria using a cytotoxicity 3 assay. Apoptosis was confirmed at the protein level, including Bax, Bcl-2, and survivin, while interruption of the cell cycle was used for final validation of apoptosis. The result showed that liriodenine inhibits proliferation of CAOV-3 cells at 37.3 μM after 24 hours of exposure. Changes in cell morphology were detected by the presence of cell membrane blebbing, chromatin condensation, and formation of apoptotic bodies. Early apoptosis was observed by Annexin V-fluorescein isothiocyanate bound to the cell membrane as early as 24 hours. Liriodenine activated the intrinsic pathway by induction of caspase-3 and caspase-9. Involvement of the intrinsic pathway in the mitochondria could be seen, with a significant increase in mitochondrial permeability and cytochrome c release, whereas the mitochondrial membrane potential was decreased. DNA fragmentation occurred at 72 hours upon exposure to liriodenine. The presence of DNA fragmentation indicates the CAOV-3 cells undergo late apoptosis or final stage of apoptosis. Confirmation of apoptosis at the protein level showed overexpression of Bax and suppression of Bcl-2 and survivin. Liriodenine inhibits progression

  17. Assessment of apoptosis occurring in spleen cells from nitrogen mustard-treated or gamma-irradiated mice.

    PubMed

    Hugel, B; Weltin, D; Holl, V; Marchal, J; Dufour, P; Freyssinet, J M; Bischoff, P L

    1998-01-01

    The short-term consequences on spleen cells of the intraperitoneal administration of nitrogen mustard (HN-2) to mice or of a whole-body gamma irradiation have been evaluated. Experiments were designed to assess the induction of apoptosis in spleen cells following exposure to these agents. The occurrence of this type of cell death was analysed by several methods, in particular the quantification in the blood of phosphotidylserine-bearing microparticles shed by apoptotic cells. In response to HN-2 or radiations, spleens undergo a rapid involution of their weight and cellularity. Ex vivo apoptosis occurs within 24 hours in cultured lymphocytes in a dose-dependent manner after both treatments. As compared with untreated controls, circulating microparticles increased 3-fold after the injection of 5 mg/kg of HN-2. PMID:9858897

  18. A Small Molecule Inhibitor Selectively Induces Apoptosis in Cells Transformed by High Risk Human Papilloma Viruses.

    PubMed

    Sheaffer, Amy K; Lee, Min S; Qi, Huilin; Chaniewski, Susan; Zheng, Xiaofan; Farr, Glen A; Esposito, Kim; Harden, David; Lei, Ming; Schweizer, Liang; Friborg, Jacques; Agler, Michele; McPhee, Fiona; Gentles, Robert; Beno, Brett R; Chupak, Lou; Mason, Stephen

    2016-01-01

    A phenotypic high-throughput cell culture screen was performed to identify compounds that prevented proliferation of the human Papilloma virus type 16 (HPV-16) transformed cell line Ca Ski. A series of quinoxaline compounds exemplified by Compound 1 was identified. Testing against a panel of cell lines demonstrated that Compound 1 selectively inhibited replication of all HPV-16, HPV-18, and HPV-31 transformed cell lines tested with 50% Inhibitory Concentration (IC50) values of 2 to 8 μM relative to IC50 values of 28 to 73 μM in HPV-negative cell lines. Treatment with Compound 1 resulted in a cascade of multiple apoptotic events, including selective activation of effector caspases 3 and 7, fragmentation of cellular DNA, and PARP (poly(ADP-ribose) polymerase) cleavage in HPV-positive cells relative to HPV-negative cells. Unregulated proliferation of HPV transformed cells is dependent on the viral oncogenes, E6 and E7. Treatment with Compound 1 resulted in a decrease in HPV E7 protein in Ca Ski cells. However, the timing of this reduction relative to other effects of compound treatment suggests that this was a consequence, rather than a cause, of the apoptotic cascade. Likewise, compound treatment resulted in no obvious effects on the E6- and E7- mediated down regulation of p53 and Rb, or their downstream effectors, p21 or PCNA. Further investigation of apoptotic signals induced by Compound 1 revealed cleavage of Caspase-8 in HPV-positive cells as early as 2 hours post-treatment, suggesting the compound initiates apoptosis through the extrinsic, death receptor-mediated, pathway of cell death. These studies provide proof of concept that cells transformed by oncogenic Papillomaviruses can be selectively induced to undergo apoptosis by compound treatment. PMID:27280728

  19. Cadmium overkill: autophagy, apoptosis and necrosis signalling in endothelial cells exposed to cadmium.

    PubMed

    Messner, Barbara; Türkcan, Adrian; Ploner, Christian; Laufer, Günther; Bernhard, David

    2016-04-01

    Apoptosis, necrosis, or autophagy-it is the mode of cell demise that defines the response of surrounding cells and organs. In case of one of the most toxic substances known to date, cadmium (Cd), and despite a large number of studies, the mode of cell death induced is still unclear. As there exists conflicting data as to which cell death mode is induced by Cd both across various cell types and within a single one, we chose to analyse Cd-induced cell death in primary human endothelial cells by investigating all possibilities that a cell faces in undergoing cell death. Our results indicate that Cd-induced death signalling starts with the causation of DNA damage and a cytosolic calcium flux. These two events lead to an apoptosis signalling-related mitochondrial membrane depolarisation and a classical DNA damage response. Simultaneously, autophagy signalling such as ER stress and phagosome formation is initiated. Importantly, we also observed lysosomal membrane permeabilization. It is the integration of all signals that results in DNA degradation and a disruption of the plasma membrane. Our data thus suggest that Cd causes the activation of multiple death signals in parallel. The genotype (for example, p53 positive or negative) as well as other factors may determine the initiation and rate of individual death signals. Differences in the signal mix and speed may explain the differing results recorded as to the Cd-induced mode of cell death thus far. In human endothelial cells it is the sum of most if not all of these signals that determine the mode of Cd-induced cell death: programmed necrosis. PMID:26588916

  20. A Small Molecule Inhibitor Selectively Induces Apoptosis in Cells Transformed by High Risk Human Papilloma Viruses

    PubMed Central

    Lee, Min S.; Qi, Huilin; Chaniewski, Susan; Zheng, Xiaofan; Farr, Glen A.; Esposito, Kim; Harden, David; Lei, Ming; Schweizer, Liang; Friborg, Jacques; Agler, Michele; McPhee, Fiona; Gentles, Robert; Beno, Brett R.; Chupak, Lou; Mason, Stephen

    2016-01-01

    A phenotypic high-throughput cell culture screen was performed to identify compounds that prevented proliferation of the human Papilloma virus type 16 (HPV-16) transformed cell line Ca Ski. A series of quinoxaline compounds exemplified by Compound 1 was identified. Testing against a panel of cell lines demonstrated that Compound 1 selectively inhibited replication of all HPV-16, HPV-18, and HPV-31 transformed cell lines tested with 50% Inhibitory Concentration (IC50) values of 2 to 8 μM relative to IC50 values of 28 to 73 μM in HPV-negative cell lines. Treatment with Compound 1 resulted in a cascade of multiple apoptotic events, including selective activation of effector caspases 3 and 7, fragmentation of cellular DNA, and PARP (poly(ADP-ribose) polymerase) cleavage in HPV-positive cells relative to HPV-negative cells. Unregulated proliferation of HPV transformed cells is dependent on the viral oncogenes, E6 and E7. Treatment with Compound 1 resulted in a decrease in HPV E7 protein in Ca Ski cells. However, the timing of this reduction relative to other effects of compound treatment suggests that this was a consequence, rather than a cause, of the apoptotic cascade. Likewise, compound treatment resulted in no obvious effects on the E6- and E7- mediated down regulation of p53 and Rb, or their downstream effectors, p21 or PCNA. Further investigation of apoptotic signals induced by Compound 1 revealed cleavage of Caspase-8 in HPV-positive cells as early as 2 hours post-treatment, suggesting the compound initiates apoptosis through the extrinsic, death receptor-mediated, pathway of cell death. These studies provide proof of concept that cells transformed by oncogenic Papillomaviruses can be selectively induced to undergo apoptosis by compound treatment. PMID:27280728

  1. Catalase Inhibits Ionizing Radiation-Induced Apoptosis in Hematopoietic Stem and Progenitor Cells

    PubMed Central

    Xiao, Xia; Luo, Hongmei; Vanek, Kenneth N.; LaRue, Amanda C.; Schulte, Bradley A.

    2015-01-01

    Hematologic toxicity is a major cause of mortality in radiation emergency scenarios and a primary side effect concern in patients undergoing chemo-radiotherapy. Therefore, there is a critical need for the development of novel and more effective approaches to manage this side effect. Catalase is a potent antioxidant enzyme that coverts hydrogen peroxide into hydrogen and water. In this study, we evaluated the efficacy of catalase as a protectant against ionizing radiation (IR)-induced toxicity in hematopoietic stem and progenitor cells (HSPCs). The results revealed that catalase treatment markedly inhibits IR-induced apoptosis in murine hematopoietic stem cells and hematopoietic progenitor cells. Subsequent colony-forming cell and cobble-stone area-forming cell assays showed that catalase-treated HSPCs can not only survive irradiation-induced apoptosis but also have higher clonogenic capacity, compared with vehicle-treated cells. Moreover, transplantation of catalase-treated irradiated HSPCs results in high levels of multi-lineage and long-term engraftments, whereas vehicle-treated irradiated HSPCs exhibit very limited hematopoiesis reconstituting capacity. Mechanistically, catalase treatment attenuates IR-induced DNA double-strand breaks and inhibits reactive oxygen species. Unexpectedly, we found that the radioprotective effect of catalase is associated with activation of the signal transducer and activator of transcription 3 (STAT3) signaling pathway and pharmacological inhibition of STAT3 abolishes the protective activity of catalase, suggesting that catalase may protect HSPCs against IR-induced toxicity via promoting STAT3 activation. Collectively, these results demonstrate a previously unrecognized mechanism by which catalase inhibits IR-induced DNA damage and apoptosis in HSPCs. PMID:25603016

  2. The effects of proinflammatory cytokines on the apoptosis of corneal endothelial cells following argon laser iridotomy.

    PubMed

    Eom, Youngsub; Kwon, Junki; Heo, Jeong-Hwa; Yun, Cheolmin; Kang, Su-Yeon; Kim, Hyo Myung; Song, Jong Suk

    2016-04-01

    The aim of this study was to evaluate the relationship between the expression of proinflammatory cytokines and the apoptosis of corneal endothelial cells after argon laser iridotomy (ALI). ALI was performed on each quadrant of the iris in the right eye of mice (ALI1 group). Left eyes were used as control group. The levels of interleukin (IL)-1β, tumor necrosis factor (TNF)-α, transforming growth factor (TGF)-β, and interferon (IFN)-γ in mice eyes were measured, and TUNEL staining was performed 12 h after ALI. Mice in the ALI-Dexa group were pretreated daily with an intraperitoneal injection of dexamethasone for 4 days before undergoing ALI and compared with mice without dexamethasone pretreatment (ALI2 group). Twelve corneas from six rabbits were incubated ex vivo with (n = 6) or without (n = 6) IL-1β. TUNEL staining was performed 24 h after ex vivo incubation. In the mice experiment, the levels of IL-1β, TNF-α, TGF-β, and IFN-γ were increased in the ALI1 group compared to the control group. Although many TUNEL-positive cells were observed in the ALI1 group, those were not detected in the control group. Dexamethasone pretreatment inhibited the increase in the levels of all four proinflammatory cytokines and reduced TUNEL-positive cells. In the rabbit experiment, TUNEL-positive cells were increased in the incubated corneas with IL-1β compared to those without IL-1β. Expression of proinflammatory cytokines following ALI seems to play a role in the apoptosis of corneal endothelial cells after ALI. Dexamethasone pretreatment inhibited increases in proinflammatory cytokines and reduced the apoptosis of corneal endothelial cells. PMID:26657139

  3. SMC3 knockdown triggers genomic instability and p53-dependent apoptosis in human and zebrafish cells

    PubMed Central

    Ghiselli, Giancarlo

    2006-01-01

    Background The structural maintenance of chromosome 3 (SMC3) protein is a constituent of a number of nuclear multimeric protein complexes that are involved in DNA recombination and repair in addition to chromosomal segregation. Overexpression of SMC3 activates a tumorigenic cascade through which mammalian cells acquire a transformed phenotype. This has led us to examine in depth how SMC3 level affects cell growth and genomic stability. In this paper the effect of SMC3 knockdown has been investigated. Results Mammalian cells that are SMC3 deficient fail to expand in a clonal population. In order to shed light on the underlying mechanism, experiments were conducted in zebrafish embryos in which cell competence to undergo apoptosis is acquired at specific stages of development and affects tissue morphogenesis. Zebrafish Smc3 is 95% identical to the human protein, is maternally contributed, and is expressed ubiquitously at all developmental stages. Antisense-mediated loss of Smc3 function leads to increased apoptosis in Smc3 expressing cells of the developing tail and notocord causing morphological malformations. The apoptosis and the ensuing phenotype can be suppressed by injection of a p53-specific MO that blocks the generation of endogenous p53 protein. Results in human cells constitutively lacking p53 or BAX, confirmed that a p53-dependent pathway mediates apoptosis in SMC3-deficient cells. A population of aneuploid cells accumulated in zebrafish embryos following Smc3-knockdown whereas in human cells the transient downregulation of SMC3 level lead to the generation of cells with amplified centrosome number. Conclusion Smc3 is required for normal embryonic development. Its deficiency affects the morphogenesis of tissues with high mitotic index by triggering an apoptotic cascade involving p53 and the downstream p53 target gene bax. Cells with low SMC3 level display centrosome abnormalities that can lead to or are the consequence of dysfunctional mitosis and

  4. Inhibition of the proteasome induces cell cycle arrest and apoptosis in mantle cell lymphoma cells.

    PubMed

    Bogner, Christian; Ringshausen, Ingo; Schneller, Folker; Fend, Falko; Quintanilla-Martinez, Leticia; Häcker, Georg; Goetze, Katharina; Oostendorp, Robert; Peschel, Christian; Decker, Thomas

    2003-07-01

    Mantle cell lymphoma (MCL) is a distinctive non-Hodgkin's lymphoma subtype, characterized by overexpression of cyclin D1 as a consequence of the chromosomal translocation t(11;14)(q13;q32). MCL remains an incurable disease, combining the unfavourable clinical features of aggressive and indolent lymphomas. The blastic variant of MCL, which is often associated with additional cytogenetic alterations, has an even worse prognosis and new treatment options are clearly needed. The present study investigated the effect of a specific proteasome inhibitor, lactacystin, on cell cycle progression and apoptosis in two lymphoma cell lines harbouring the t(11;14)(q13;q32) and additional cytogenetic alterations, including p53 mutation (NCEB) and p16 deletion (Granta 519). Granta cells were more susceptible to inhibition of the proteasome with respect to inhibition of proliferation and apoptosis induction. No changes were observed in the expression levels of the G1 regulatory molecules cyclin D1 and cdk4, but cell cycle arrest and apoptosis induction was accompanied by accumulation of the cdk inhibitor p21 in both cell lines. Increased p53 expression was only observed in Granta cells with wild-type p53. Cleavage of procaspase-3 and -9 was observed but cleavage of procaspase-8 was not involved in apoptosis induction. The proapoptotic effect of lactacystin was reversed by pretreatment with the pancaspase inhibitor zVAD.fmk. Lactacystin was also effective in inducing apoptosis in lymphoma cells from MCL patients. We conclude that inhibition of the proteasome might be a promising therapeutic approach for this incurable disease. PMID:12846895

  5. Cupressus lusitanica (Cupressaceae) leaf extract induces apoptosis in cancer cells.

    PubMed

    Lopéz, L; Villavicencio, M A; Albores, A; Martínez, M; de la Garza, J; Meléndez-Zajgla, J; Maldonado, V

    2002-05-01

    A crude ethanolic extract of Cupressus lusitanica Mill. leaves demonstrate cytotoxicity in a panel of cancer cell lines. Cell death was due to apoptosis, as assessed by morphologic features (chromatin condensation and apoptotic bodies formation) and specific DNA fragmentation detected by in situ end-labeling of DNA breaks (TUNEL). The apoptotic cell death was induced timely in a dose-dependent manner. Despite the absence of changes in the expression levels of antiapoptotic protein Bcl-2, proapoptotic Bax protein variants omega and delta were increased. These results warrant further research of possible antitumor compounds in this plant. PMID:12007700

  6. Oridonin phosphate-induced autophagy effectively enhances cell apoptosis of human breast cancer cells.

    PubMed

    Li, Yue; Wang, Ying; Wang, Suihai; Gao, Yanjun; Zhang, Xuefeng; Lu, Chunhua

    2015-01-01

    Oridonin is an active diterpenoid, which was extracted from traditional Chinese herbs and had been widely used in clinical treatment nowadays. Oridonin phosphate is one of the derivatives of oridonin. In the present study, we explored its anti-tumor effect and investigated the molecular mechanism of oridonin phosphate in breast cancer cell lines. Firstly, cell viability was analyzed by MTT assay. The breast cancer cells were treated with increasing concentrations of oridonin phosphate for 24, 48 and 72 h, respectively. The results demonstrated that oridonin phosphate inhibited the proliferation of MDA-MB-436 and MDA-MB-231 cells in a dose- and time-dependent manner. Next, cell apoptosis rate was detected in oridonin phosphate-treated breast cancer cells by Annexin V-FITC/PI dual staining analysis and the data demonstrated that oridonin phosphate induced cell apoptosis of breast cancer cells in time- and dose-dependent manner. Moreover, apoptosis-related proteins were detected by Western blotting analysis. The results showed that the expression level of Bax was up-regulated and the expression level of Bcl-2 was down-regulated. Meanwhile, the level of cleaved caspase-9 was significantly increased when the cells were treated with 40 μM of oridonin phosphate for 48 h, although the expression level of pro-caspase-9 was not obviously changed. All of the data revealed that mitochondrial apoptosis pathway may be involved in the cell apoptosis induced by oridonin phosphate in breast cancer cells. Importantly, the expression levels of autophagy-related protein beclin-1 and LC3-II were significantly higher in oridonin phosphate-treated breast cancer cell lines MDA-MB-436 and MDA-MB-231 for 48 h. Additionally, we further explored the relationship between apoptosis and autophagy specifically induced by oridonin phosphate in breast cancer cells. The result showed that inhibition of autophagy suppressed the cell apoptosis in oridonin phosphate-treated MDA-MB-436 cells. Taken

  7. Inhibition of TLR8 mediated signaling promotes BCG induced apoptosis in THP-1 cells.

    PubMed

    Tang, Jun; Zhan, Lingjun; Qin, Chuan

    2016-04-01

    Apoptosis was considered as one of the important host defense mechanisms against mycobacteria infection. In macrophage, the main target cell of Mycobacterium tuberculosis, apoptosis after infection could help kill the bacillus inside and process the antigens for further presentation and proper immune response. Here, we identified a role of TLR8 during the apoptosis induced by Bacillus Calmette Guérin (BCG) infection in THP-1 cells. Knockdown TLR8 further increased the apoptosis induced by BCG infection, and this enhanced apoptosis was caspase-dependent. During this process, Erk1/2, JNK and NFκB pathways were negatively affected and contributed to the enhanced apoptosis. PMID:26657720

  8. Mechanism of cell death during warm hepatic ischemia-reperfusion in rats: apoptosis or necrosis?

    PubMed

    Gujral, J S; Bucci, T J; Farhood, A; Jaeschke, H

    2001-02-01

    Reperfusion injury can cause liver dysfunction after cold storage and warm ischemia. Recently it has been suggested that more than 50% of hepatocytes and sinusoidal endothelial cells (SEC) are undergoing apoptosis during the first 24 hours of reperfusion. The aim of our study was to quantify apoptotic and necrotic hepatocytes and apoptotic SEC after 60 or 120 minutes of warm, partial no-flow ischemia and 0 to 24 hours reperfusion in male SD rats. Apoptotic cells were identified by TUNEL assay in combination with morphological criteria. After 60 minutes of ischemia and 1 hour of reperfusion there was a significant increase of apoptotic hepatocytes (0.7 +/- 0.1% vs. 0.3 +/- 0.1% in controls) and SEC (1.5 +/- 0.6% vs. 0.3 +/- 0.1% in controls). The number of apoptotic SEC and hepatocytes was not different from controls at 6 hours or 24 hours of reperfusion. In contrast, the number of necrotic hepatocytes was quantified as 12 +/- 2% at 1 hour, 34 +/- 6% at 6 hours, and 57 +/- 11% at 24 hours. These results correlated with the increase in plasma ALT levels at these time points. Longer (120 min) ischemia times did not affect the number of apoptotic cells but increased hepatocellular necrosis to 58 +/- 4% at 6 hours reperfusion. No significant increase in caspase-3 activity and processing was detectable in any of these livers. Moreover, the caspase inhibitor Z-Asp-cmk (2 mg/kg IV) had no significant effect on reperfusion injury. Our results suggest that only a small minority of SEC and hepatocytes undergo apoptosis after 60 to 120 minutes of warm ischemia followed by 0 to 24 hours of reperfusion. Oncotic necrosis appears to be the principal mechanism of cell death for both cell types. PMID:11172341

  9. Antiplatelet drugs induce apoptosis in cultured cancer cells.

    PubMed

    Chen, W H; Yin, H L; Chang, Y Y; Lan, M Y; Hsu, H Y; Liu, J S

    1997-10-01

    In order to understand if antiplatelet drugs possess direct antineoplastic property, we tested the apoptotic effect of 5 popularly marketed antiplatelet drugs in Taiwan in 6 cultured cancer cell lines (Hep 3B hepatocarcinoma, U87-MG malignant glioma, PC-3 prostate adenocarcinoma, HeLa cervical adenocarcinoma, HL-60 preleukemia and K-562 chronic myelogenous leukemia). While acetylsalicylate and flunarizine exerted no effect on these cancer cells, pentoxifyline (PTX), dipyridamole (DYA) and ticlopidine hydrochloride (T. HCl) displayed a time and dose-dependent apoptotic effect on them except for HL-60 and K-562 cells. PTX induced apoptosis in U87-MG, Hep 3B and HeLa cells, DYA in HeLa cells, while T. HCl in U87-MG, Hep 3B, PC-3 and HeLa cells. Adriamycin also provoked apoptotic effect in all 6 cell lines but neither PTX, DYA nor T. HCl acted synergy with adriamycin to HeLa cells, implicating that they may share a similar pathway for inducing apoptosis. Therefore, our results show that the antiplatelet drugs do possess antineoplastic property in vitro. A co-administration of antiplatelet drugs is noteworthy for an alternative adjunctive therapy in cancer patients. PMID:9385774

  10. Piperlongumine Suppresses Proliferation of Human Oral Squamous Cell Carcinoma through Cell Cycle Arrest, Apoptosis and Senescence.

    PubMed

    Chen, San-Yuan; Liu, Geng-Hung; Chao, Wen-Ying; Shi, Chung-Sheng; Lin, Ching-Yen; Lim, Yun-Ping; Lu, Chieh-Hsiang; Lai, Peng-Yeh; Chen, Hau-Ren; Lee, Ying-Ray

    2016-01-01

    Oral squamous cell carcinoma (OSCC), an aggressive cancer originating in the oral cavity, is one of the leading causes of cancer deaths in males worldwide. This study investigated the antitumor activity and mechanisms of piperlongumine (PL), a natural compound isolated from Piper longum L., in human OSCC cells. The effects of PL on cell proliferation, the cell cycle, apoptosis, senescence and reactive oxygen species (ROS) levels in human OSCC cells were investigated. PL effectively inhibited cell growth, caused cell cycle arrest and induced apoptosis and senescence in OSCC cells. Moreover, PL-mediated anti-human OSCC behavior was inhibited by an ROS scavenger N-acetyl-l-cysteine (NAC) treatment, suggesting that regulation of ROS was involved in the mechanism of the anticancer activity of PL. These findings suggest that PL suppresses tumor growth by regulating the cell cycle and inducing apoptosis and senescence and is a potential chemotherapy agent for human OSCC cells. PMID:27120594

  11. Piperlongumine Suppresses Proliferation of Human Oral Squamous Cell Carcinoma through Cell Cycle Arrest, Apoptosis and Senescence

    PubMed Central

    Chen, San-Yuan; Liu, Geng-Hung; Chao, Wen-Ying; Shi, Chung-Sheng; Lin, Ching-Yen; Lim, Yun-Ping; Lu, Chieh-Hsiang; Lai, Peng-Yeh; Chen, Hau-Ren; Lee, Ying-Ray

    2016-01-01

    Oral squamous cell carcinoma (OSCC), an aggressive cancer originating in the oral cavity, is one of the leading causes of cancer deaths in males worldwide. This study investigated the antitumor activity and mechanisms of piperlongumine (PL), a natural compound isolated from Piper longum L., in human OSCC cells. The effects of PL on cell proliferation, the cell cycle, apoptosis, senescence and reactive oxygen species (ROS) levels in human OSCC cells were investigated. PL effectively inhibited cell growth, caused cell cycle arrest and induced apoptosis and senescence in OSCC cells. Moreover, PL-mediated anti-human OSCC behavior was inhibited by an ROS scavenger N-acetyl-l-cysteine (NAC) treatment, suggesting that regulation of ROS was involved in the mechanism of the anticancer activity of PL. These findings suggest that PL suppresses tumor growth by regulating the cell cycle and inducing apoptosis and senescence and is a potential chemotherapy agent for human OSCC cells. PMID:27120594

  12. Effect of quercetin on apoptosis of PANC-1 cells

    PubMed Central

    Lee, Joo Hyun; Lee, Han-Beom; Jung, Gum O; Oh, Jung Taek; Park, Dong Eun

    2013-01-01

    Purpose To investigate the chemotherapeutic effect of quercetin against cancer cells, signaling pathway of apoptosis was explored in human pancreatic cells. Methods Various anticancer drugs including adriamycin, cisplatin, 5-fluorouracil (5-FU) and gemcitabine were used. Cell viability was measured by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphe-nyltetra zolium bromide assay. Apoptosis was determined by 4'-6-diamidino-2-phenylindole nuclei staining and flow cytometry in PANC-1 cells treated with 50 µg/mL quercetin for 24 hours. Expression of endoplas mic reticulum (ER) stress mediators including, Grp78/Bip, p-PERK, PERK, ATF4, ATF6 and GADD153/CHOP proteins were measured by Western blot analysis. Mitochondrial membrane potential was measured by fluorescence staining with JC-1, rhodamine 123. Quercetin induced the apoptosis of PANC-1, which was characterized as nucleic acid and genomic DNA fragmentation, chromatin condensation, and sub-G0/G1 fraction of cell cycle increase. But not adriamycin, cisplatin, gemcitabine, and 5-FU. PANC-1 cells were markedly sensitive to quercetin. Results Treatment with quercetin resulted in the increased accumulation of intracellular Ca2+ ion. Treatment with quercetin also increased the expression of Grp78/Bip and GADD153/CHOP protein and induced mitochondrial dysfunction. Quercetin exerted cytotoxicity against human pancreatic cancer cells via ER stress-mediated apoptotic signaling including reactive oxygen species production and mitochondrial dysfunction. Conclusion These data suggest that quercetin may be an important modulator of chemosensitivity of cancer cells against anticancer chemotherapeutic agents. PMID:24368982

  13. Down-regulation of Mcl-1 through GSK-3β activation contributes to arsenic trioxide-induced apoptosis in acute myeloid leukemia cells

    PubMed Central

    Wang, Rui; Xia, Lijuan; Gabrilove, Janice; Waxman, Samuel; Jing, Yongkui

    2012-01-01

    Arsenic trioxide (ATO) induces disease remission in acute promyelocytic leukemia (APL) patients, but not in non-APL acute myeloid leukemia (AML) patients. ATO at therapeutic concentrations (1-2 μM) induce APL NB4, but not non-APL HL-60, cells to undergo apoptosis through the mitochondrial pathway. The role of antiapoptotic protein Mcl-1 in ATO-induced apoptosis was determined. The levels of Mcl-1 were decreased in NB4, but not in HL-60, cells after ATO treatment through proteasomal degradation. Both GSK3β inhibitor SB216763 and siRNA blocked ATO-induced Mcl-1 reduction as well as attenuated ATO-induced apoptosis in NB4 cells. Silencing Mcl-1 sensitized HL-60 cells to ATO-induced apoptosis. Both ERK and AKT inhibitors decreased Mcl-1 levels and enhanced ATO-induced apoptosis in HL-60 cells. Sorafenib, a Raf inhibitor, activated GSK3β by inhibiting its phosphorylation, decreased Mcl-1 levels, and decreased intracellular glutathione levels in HL-60 cells. Sorafenib plus ATO augmented ROS production and apoptosis induction in HL-60 cells and in primary AML cells. These results indicate that ATO induces Mcl-1 degradation through activation of GSK3β in APL cells and provide a rationale for utilizing ATO in combination with sorafenib for the treatment of non-APL AML patients. PMID:22751450

  14. Pharmacological induction of cell surface GRP78 contributes to apoptosis in triple negative breast cancer cells.

    PubMed

    Raiter, Annat; Yerushalmi, Rinat; Hardy, Britta

    2014-11-30

    Breast cancer tumor with triple-negative receptors (estrogen, progesterone and Her 2, receptors) is the most aggressive and deadly subtype, with high rates of disease recurrence and poor survival. Here, we show that induction in cell surface GRP78 by doxorubicin and tunicamycin was associated with CHOP/GADD153 upregulation and increase in apoptosis in triple negative breast cancer tumor cells. GRP78 is a major regulator of the stress induced unfolded protein response pathway and CHOP/GADD153 is a pro-apoptotic transcription factor associated exclusively with stress induced apoptosis. The blocking of cell surface GRP78 by anti-GRP78 antibody prevented apoptosis, suggesting that induction of cell surface GRP78 by doxorubicin and tunicamycin is required for apoptosis. A better understanding of stress induction of apoptotic signaling in triple negative breast cancer cells may help to define new therapeutic strategies. PMID:25360516

  15. Alpha-1 Antitrypsin and Lung Cell Apoptosis.

    PubMed

    Serban, Karina A; Petrache, Irina

    2016-04-01

    Discovery of alpha-1 antitrypsin (A1AT) as the principal circulating inhibitor of neutrophil elastase was critical to the appreciation of protease/antiprotease imbalance involvement in the pathogenesis of emphysema. Additional targets of A1AT have been uncovered, along with their contribution to alveolar wall destruction induced by cigarette smoke exposure. We highlight in this report mechanisms of A1AT antiapoptotic effects on structural lung endothelial cells. This function was largely dependent on uptake of the protein from the circulation via clathrin- and, in part, caveolae-mediated endocytosis and on specific interactions with cysteine proteases such as capsase-3, -6, and -7. Exposures to cigarette smoke diminished A1AT intracellular uptake and its anticaspase action, suggesting that even in A1AT-suficient individuals, cigarette smoke may weaken the serpin's endothelial prosurvival effect. In addition, cigarette smoke exposure or genetic mutations known to induce posttranslational modifications such as oxidation or polymerization may alter A1AT bidirectional intracellular traffic in endothelial cells and thus determine its functional bioavailability in certain lung compartments. Uncovering and harnessing the A1AT canonical and noncanonical mechanisms will advance our understanding of the pathogenesis of emphysema and may provide means to improve the effectiveness of therapies in both A1AT-sufficient and A1AT-deficient individuals. PMID:27115949

  16. PDT-induced apoptosis in arterial smooth muscles cells

    NASA Astrophysics Data System (ADS)

    Nyamekye, Isaac; Renick, R.; Gilbert, C.; McEwan, Jean R.; Evan, G.; Bishop, Christopher C. R.; Bown, Stephen G.

    1995-03-01

    PDT kills smooth muscle cells (SMC) in vivo and thus prevents intimal hyperplasia after angioplasty. It causes little inflammation and structural integrity of the artery is not compromised. We have studied the process of the SMC death in vitro. Cultured rat SMC (cell line sv40 ATCC) were sensitized with aluminum disulphonated phthalocyanine (AlS2Pc), and then irradiated with 675 nm laser light (2.5 J/cm2). Controls were studied using only sensitizer or laser for treatment. The cells were incubated and the dying process observed with a time lapse video and microscope system. PDT caused a characteristic pattern of death. Cells lost contact with neighbors, shrank, and showed hyperactivity and membrane ruffling. The cells imploded into active and condensed membrane bound vesicles which were terminally reduced to residual bodies. These are the morphological changes of apoptosis. The control cells which were given AlS2Pc alone or laser alone showed no death. PDT induced cultured arterial SMC death by apoptosis rather than necrosis. An apoptotic mechanism of cell death in vivo would explain the relative lack of inflammation and local tissue destruction in the face of massive death.

  17. Inhibition of proliferation and differentiation and promotion of apoptosis by cyclin L2 in mouse embryonic carcinoma P19 cells

    SciTech Connect

    Zhuo, Lili; Gong, Jie; Yang, Rong; Sheng, Yanhui; Zhou, Lei; Kong, Xiangqing; Cao, Kejiang

    2009-12-18

    Cyclin L2 (CCNL2) is a novel member of the cyclin gene family. In a previous study, we demonstrated that CCNL2 expression was upregulated in ventricular septum tissues from patients with ventricular septal defect compared to healthy controls. In the present study, we established a stable CCNL2-overexpressing P19 cell line that can differentiate to myocardial cells when treated with 1% dimethyl sulfoxide (DMSO). Our data showed that stable CCNL2-overexpressing P19 cells were less differentiated after treatment with 1% DMSO and that expression of myocardial cell differentiation-related genes (such as cardiac actin, GATA4, Mef2C, Nkx2.5, and BNP) were reduced compared to vector-only transfected P19. Moreover, P19 cells overexpressing the CCNL2 gene had a reduced growth rate and a remarkably decreased S phase. We also found that these cells underwent apoptosis, as detected by two different apoptosis assays. The anti-apoptotic Bcl-2 protein was also downregulated in these cells. In addition, real-time PCR analysis revealed that expression of Wnt and {beta}-catenin was suppressed and GSK3{beta} was induced in the CCNL2-overexpressing P19 cells. These data suggest that overexpression of CCNL2 inhibited proliferation and differentiation of mouse embryonic carcinoma P19 cells and induced them to undergo apoptosis, possibly through the Wnt signal transduction pathway.

  18. In vivo and in vitro studies on apoptosis in OSE cells and inclusion cysts of pregnant heifers

    PubMed Central

    Saddick, Salina Y.

    2013-01-01

    Elevated progesterone concentration during pregnancy and use of progesterone-like contraceptives are known to reduce ovarian cancers. This study was undertaken to decipher whether or not there is any relationship between progesterone (also oestrogen)-mediated ovarian surface epithelium (OSE) apoptosis and expression of p53, a cell-cycle arresting protein and potential tumour suppressor. Immunohistochemical staining with cytokeratin confirmed epithelial nature of the cells in the OSE layer and inclusion cysts that invaginate inside stroma after ovulation takes place. The in situ apoptosis index was determined during oestrus, and at mid and late-pregnancy stages in heifers. Epithelia of both tissues exhibited significantly high nuclear staining, suggesting that these cells are aiming to apoptotic destruction. To further establish a role of progesterone, the OSE cells were exposed in vitro to two concentrations of oestrogen and progesterone. It was revealed that progesterone at both concentrations and oestrogen only at high concentration converted a large proportion of these cells apoptotic. The stimulatory effect of progesterone (and to some extent oestrogen) was also seen on p53 expression in the same cultivated OSE cells. The steroid dosage dependence for apoptosis and p53 expression was also somewhat similar. Assuming that progesterone action is mediated through p53-caused apoptosis as a mechanism to evade malignant transformation of OSE cells, p53 expression at mRNA and protein level was investigated in the OSE layer in proximity to stroma, antrum and corpus luteum (CL). In cycling animals CL produces a large amount of progesterone and also oestrogen to maintain the post-ovulatory cycle and to suppress the gonadotropin production. Hence, cells undergoing re-epithelialization and which are in contact with CL were expected to undergo maximum apoptotic modification. Indeed we got the maximum p53/p53 gene expression in these cells. We conclude that progesterone

  19. Metformin prevents methylglyoxal-induced apoptosis of mouse Schwann cells

    SciTech Connect

    Ota, Kimiko; Nakamura, Jiro; Li, Weiguo; Kozakae, Mika; Watarai, Atsuko; Nakamura, Nobuhisa; Yasuda, Yutaka; Nakashima, Eirtaro; Naruse, Keiko; Watabe, Kazuhiko; Kato, Koichi; Oiso, Yutaka; Hamada, Yoji . E-mail: yhama@med.nagoya-u.ac.jp

    2007-05-25

    Methylglyoxal (MG) is involved in the pathogenesis of diabetic complications via the formation of advanced glycation end products (AGEs) and reactive oxygen species (ROS). To clarify whether the antidiabetic drug metformin prevents Schwann cell damage induced by MG, we cultured mouse Schwann cells in the presence of MG and metformin. Cell apoptosis was evaluated using Hoechst 33342 nuclear staining, caspase-3 activity, and c-Jun-N-terminal kinase (JNK) phosphorylation. Intracellular ROS formation was determined by flow cytometry, and AMP-activated kinase (AMPK) phosphorylation was also examined. MG treatment resulted in blunted cell proliferation, an increase in the number of apoptotic cells, and the activation of caspase-3 and JNK along with enhanced intracellular ROS formation. All of these changes were significantly inhibited by metformin. No significant activation of AMPK by MG or metformin was observed. Taken together, metformin likely prevents MG-induced apoptotic signals in mouse Schwann cells by inhibiting the formation of AGEs and ROS.

  20. Connexins protect mouse pancreatic β cells against apoptosis.

    PubMed

    Klee, Philippe; Allagnat, Florent; Pontes, Helena; Cederroth, Manon; Charollais, Anne; Caille, Dorothée; Britan, Aurore; Haefliger, Jacques-Antoine; Meda, Paolo

    2011-12-01

    Type 1 diabetes develops when most insulin-producing β cells of the pancreas are killed by an autoimmune attack. The in vivo conditions modulating the sensitivity and resistance of β cells to this attack remain largely obscure. Here, we show that connexin 36 (Cx36), a trans-membrane protein that forms gap junctions between β cells in the pancreatic islets, protects mouse β cells against both cytotoxic drugs and cytokines that prevail in the islet environment at the onset of type 1 diabetes. We documented that this protection was at least partially dependent on intercellular communication, which Cx36 and other types of connexin channels establish within pancreatic islets. We further found that proinflammatory cytokines decreased expression of Cx36 and that experimental reduction or augmentation of Cx36 levels increased or decreased β cell apoptosis, respectively. Thus, we conclude that Cx36 is central to β cell protection from toxic insults. PMID:22056383

  1. Connexins protect mouse pancreatic β cells against apoptosis

    PubMed Central

    Klee, Philippe; Allagnat, Florent; Pontes, Helena; Cederroth, Manon; Charollais, Anne; Caille, Dorothée; Britan, Aurore; Haefliger, Jacques-Antoine; Meda, Paolo

    2011-01-01

    Type 1 diabetes develops when most insulin-producing β cells of the pancreas are killed by an autoimmune attack. The in vivo conditions modulating the sensitivity and resistance of β cells to this attack remain largely obscure. Here, we show that connexin 36 (Cx36), a trans-membrane protein that forms gap junctions between β cells in the pancreatic islets, protects mouse β cells against both cytotoxic drugs and cytokines that prevail in the islet environment at the onset of type 1 diabetes. We documented that this protection was at least partially dependent on intercellular communication, which Cx36 and other types of connexin channels establish within pancreatic islets. We further found that proinflammatory cytokines decreased expression of Cx36 and that experimental reduction or augmentation of Cx36 levels increased or decreased β cell apoptosis, respectively. Thus, we conclude that Cx36 is central to β cell protection from toxic insults. PMID:22056383

  2. Metformin impairs growth of endometrial cancer cells via cell cycle arrest and concomitant autophagy and apoptosis

    PubMed Central

    2014-01-01

    Background Effective therapies for early endometrial cancer usually involve surgical excision and consequent infertility Therefore, new treatment approaches that preserve fertility should be developed. Metformin, a well-tolerated anti-diabetic drug, can inhibit cancer cell growth. However, the mechanism of metformin action is not well understood. Here we investigate the roles of autophagy and apoptosis in the anti-cancer effects of metformin on endometrial cancer cells. Methods Ishikawa endometrial cancer cells were treated with metformin. WST-8 assays, colony formation assays, flow cytometry, caspase luminescence measurement, immunofluorescence, and western blots were used to assess the effects of metformin on cell viability, proliferation, cell cycle progression, apoptosis, and autophagy. Results Metformin-treated cells exhibited significantly lower viability and proliferation and significantly more cell cycle arrest in G1 and G2/M than control cells. These cells also exhibited significantly more apoptosis via both intrinsic and extrinsic pathways. In addition, metformin treatment induced autophagy. Inhibition of autophagy, either by Beclin1 knockdown or by 3-methyladenine-mediated inhibition of caspase-3/7, suppressed the anti-proliferative effects of metformin on endometrial cancer cells. These findings indicate that the anti-proliferative effects and apoptosis caused by metformin are partially or completely dependent on autophagy. Conclusions We showed that metformin suppresses endometrial cancer cell growth via cell cycle arrest and concomitant autophagy and apoptosis. PMID:24966801

  3. A novel method for detecting apoptosis shows that hepatocytes undergo a time dependent increase in DNA cleavage and chromatin condensation which is augmented after TGF-beta 1 treatment.

    PubMed

    Cain, K; Inayat-Hussain, S H; Couet, C; Qin, H M; Oberhammer, F A

    1996-04-01

    This study describes a new method for quantitating apoptosis in hepatocyte monolayers in which nuclei were isolated from the cells and DNA strand breaks detected by in situ end-labeling and flow cytometry. Most (97%) nuclei from untreated hepatocytes had low end-labelling and were derived from non-apoptotic cells. Approximately 2-3% of the nuclei had high end-labelling and originated from apoptotic hepatocytes. The numbers of these nuclei increased linearly from 3 to 85% between 0 and 48 h after treatment with transforming growth factor-beta 1 (TGF-beta 1). However, a morphological assessment of apoptosis with Hoechst H33258 showed that the proportion of apoptotic nuclei plateaued at 18-19% between 24 and 48 h after TGF-beta 1 treatment. Thus, the in situ end-labeling technique also detected DNA cleavage in nuclei which did not have an obvious apoptotic morphology. Confocal microscopy of low and high end-labelled nuclei which had been separated by fluorescent cell sorting showed that nuclei with high levels of end-labeling exhibited a wide diversity of morphologies. These included nuclei with little or no chromatin condensation and nuclei with characteristic apoptotic morphology. In addition, nuclei from untreated hepatocytes contained low levels of DNA cleavage, which were localized in areas of condensed chromatin and increased according to the time in culture. Thus, hepatocytes undergo a progressive and cumulative process of DNA cleavage/chromatin condensation which is markedly enhanced by TGF-beta 1. PMID:8900474

  4. Liver Fibrosis and Protection Mechanisms Action of Medicinal Plants Targeting Apoptosis of Hepatocytes and Hepatic Stellate Cells

    PubMed Central

    Moreno-Cuevas, Jorge E.; González-Garza, Maria Teresa; Rodríguez-Montalvo, Carlos; Cruz-Vega, Delia Elva

    2014-01-01

    Following chronic liver injury, hepatocytes undergo apoptosis leading to activation of hepatic stellate cells (HSC). Consequently, activated HSC proliferate and produce excessive extracellular matrix, responsible for the scar formation. The pandemic trend of obesity, combined with the high incidence of alcohol intake and viral hepatitis infections, highlights the urgent need to find accessible antifibrotic therapies. Treatment strategies should take into account the versatility of its pathogenesis and act on all the cell lines involved to reduce liver fibrosis. Medicinal plants are achieving popularity as antifibrotic agents, supported by their safety, cost-effectiveness, and versatility. This review will describe the role of hepatocytes and HSC in the pathogenesis of liver fibrosis and detail the mechanisms of modulation of apoptosis of both cell lines by twelve known hepatoprotective plants in order to reduce liver fibrosis. PMID:25505905

  5. Prostaglandin F2α promotes muscle cell survival and growth through upregulation of the inhibitor of apoptosis protein BRUCE

    PubMed Central

    Jansen, Katie M.; Pavlath, Grace K.

    2009-01-01

    During skeletal muscle growth and regeneration, the majority of differentiating myoblasts undergoes cell-cell fusion to form multinucleated myofibers, while a proportion of myoblasts undergoes apoptosis. The treatment of myoblasts with prostaglandin F2α (PGF2α) during myogenesis in vitro leads to the formation of large myotubes, but the mechanism by which PGF2α promotes myotube growth has not been investigated. Here, we demonstrate that PGF2α reduces cell death during myogenesis in vitro and in vivo. In addition, we show that PGF2α increases expression of the inhibitor of apoptosis protein (IAP) BRUCE through a pathway dependent upon the nuclear factor of activated T cell 2 (NFATC2) transcription factor. Importantly, PGF2α-mediated reduction in muscle cell death is dependent upon BRUCE, and overexpression of BRUCE is sufficient to promote muscle cell survival and growth. These results establish a previously unrecognized link between NFAT signaling and regulation of IAP expression and are the first to identify a signaling pathway that increases BRUCE expression. In addition, our results provide evidence that increasing the pool of muscle cells available for fusion by inhibiting cell death enhances myotube growth. PMID:18566603

  6. The absence of Prep1 causes p53-dependent apoptosis of mouse pluripotent epiblast cells.

    PubMed

    Fernandez-Diaz, Luis C; Laurent, Audrey; Girasoli, Sara; Turco, Margherita; Longobardi, Elena; Iotti, Giorgio; Jenkins, Nancy A; Fiorenza, Maria Teresa; Copeland, Neal G; Blasi, Francesco

    2010-10-01

    Disruption of mouse Prep1, which codes for a homeodomain transcription factor, leads to embryonic lethality during post-implantation stages. Prep1(-/-) embryos stop developing after implantation and before anterior visceral endoderm (AVE) formation. In Prep1(-/-) embryos at E6.5 (onset of gastrulation), the AVE is absent and the proliferating extra-embryonic ectoderm and epiblast, marked by Bmp4 and Oct4, respectively, are reduced in size. At E.7.5, Prep1(-/-) embryos are small and very delayed, showing no evidence of primitive streak or of differentiated embryonic lineages. Bmp4 is expressed residually, while the reduced number of Oct4-positive cells is constant up to E8.5. At E6.5, Prep1(-/-) embryos retain a normal mitotic index but show a major increase in cleaved caspase 3 and TUNEL staining, indicating apoptosis. Therefore, the mouse embryo requires Prep1 when undergoing maximal expansion in cell number. Indeed, the phenotype is partially rescued in a p53(-/-), but not in a p16(-/-), background. Apoptosis is probably due to DNA damage as Atm downregulation exacerbates the phenotype. Despite this early lethal phenotype, Prep1 is not essential for ES cell establishment. A differential embryonic expression pattern underscores the unique function of Prep1 within the Meis-Prep family. PMID:20826531

  7. Effect of 5alpha-dihydrotestosterone and testosterone on apoptosis in human dermal papilla cells.

    PubMed

    Winiarska, A; Mandt, N; Kamp, H; Hossini, A; Seltmann, H; Zouboulis, C C; Blume-Peytavi, U

    2006-01-01

    Pathogenetic mechanisms in androgenetic alopecia are not yet fully understood; however, it is commonly accepted that androgens like testosterone (T) and 5alpha-dihydrotestosterone (5alpha-DHT) inhibit hair follicle activity with early induction of the catagen. Thus, we investigated the influence of T and 5alpha-DHT on proliferation, cell death and bcl-2/bax expression in cultured dermal papilla cells (DPC) from nonbalding scalp regions of healthy volunteers. T and 5alpha-DHT induced apoptosis in DPC in a dose-dependent and time-related manner; in addition a necrotic effect due to T at 10(-5) M was found. Interestingly, bcl-2 protein expression was decreased in T- and 5alpha-DHT-treated cells, leading to an increase in the bax/bcl-2 ratio. In addition, T and 5alpha-DHT induced proteolytic cleavage of caspase 8 and inhibited proliferation of DPC at 10(-5) M. High concentrations of T and 5alpha-DHT were needed to induce apoptotic effects in DPC. These data suggest that DPC from nonbalding scalp regions do have the capacity to undergo apoptosis, but need a high androgen stimulus. The present study provides an interesting new pathogenetic approach in androgenetic alopecia. PMID:16931898

  8. Apoptosis like cell death in Raillietina echinobothrida induced by resveratrol.

    PubMed

    Giri, Bikash Ranjan; Roy, Bishnupada

    2015-08-01

    Northeast India is geographically nestled as one of the biodiversity hotspots, rich in traditionally used medicinal plants. Resveratrol, a naturally occurring phytoalexin found in berries, peanuts, grapes, red wine and also in numerous anthelmintic plants, has attracted wide interest because of its diverse pharmacological characteristics. Recently, anthelmintic potential of the compound is established. The present study was carried out to understand the possible mechanism of action of resveratrol on poultry tapeworm Raillietina echinobothrida. Resveratrol showed excellent cestocidal activity in a dose dependent manner as revealed through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction assay. The progressive ultrastructural alterations followed by complete disruption of nuclear membrane, chromosomal condensation and in situ DNA fragmentation confirm the occurrence of apoptosis like cell death. Increased pro-apoptotic caspase activity and significant decreases in mitochondrial membrane potential in R. echinobothrida exposed to resveratrol confirm the involvement of mitochondria in the process of apoptosis. PMID:26267101

  9. Tumor-initiating label-retaining cancer cells in human gastrointestinal cancers undergo asymmetric cell division.

    PubMed

    Xin, Hong-Wu; Hari, Danielle M; Mullinax, John E; Ambe, Chenwi M; Koizumi, Tomotake; Ray, Satyajit; Anderson, Andrew J; Wiegand, Gordon W; Garfield, Susan H; Thorgeirsson, Snorri S; Avital, Itzhak

    2012-04-01

    Label-retaining cells (LRCs) have been proposed to represent adult tissue stem cells. LRCs are hypothesized to result from either slow cycling or asymmetric cell division (ACD). However, the stem cell nature and whether LRC undergo ACD remain controversial. Here, we demonstrate label-retaining cancer cells (LRCCs) in several gastrointestinal (GI) cancers including fresh surgical specimens. Using a novel method for isolation of live LRCC, we demonstrate that a subpopulation of LRCC is actively dividing and exhibits stem cells and pluripotency gene expression profiles. Using real-time confocal microscopic cinematography, we show live LRCC undergoing asymmetric nonrandom chromosomal cosegregation LRC division. Importantly, LRCCs have greater tumor-initiating capacity than non-LRCCs. Based on our data and that cancers develop in tissues that harbor normal-LRC, we propose that LRCC might represent a novel population of GI stem-like cancer cells. LRCC may provide novel mechanistic insights into the biology of cancer and regenerative medicine and present novel targets for cancer treatment. PMID:22331764

  10. microRNA-22 attenuates neuronal cell apoptosis in a cell model of traumatic brain injury

    PubMed Central

    Ma, Ji; Shui, Shaofeng; Han, Xinwei; Guo, Dong; Li, Tengfei; Yan, Lei

    2016-01-01

    Traumatic brain injury (TBI) is a major cause of injury-related deaths, and the mechanism of TBI has become a research focus, but little is known about the mechanism of microRNAs in TBI. The aim of this study is the role of microRNA-22 (miR-22) in TBI-induced neuronal cell apoptosis. Rat cortical neurons were cultured and the TBI model was induced by scratch injury in vitro, before which miR-22 level was altered by transfection of agomir or antagomir. Lactate dehydrogenase (LDH) release and TUNEL assays were performed to examine neuronal cell injury and apoptosis. The activity of caspase 3 (CASP3) and level changes of several apoptosis factors including B-cell lymphoma 2 (BCL2), BCL2-associated X protein (BAX), phosphatase and tensin homolog (PTEN) and v-AKT murine thymoma viral oncogene homolog 1 (AKT1) were detected. Results showed that TBI model cells possessed a downregulated miR-22 level (P < 0.001) and more LDH release and apoptotic cells indicating the aggravated neuronal cell injury and apoptosis induced by TBI. miR-22 agomir attenuated neuronal cell injury and apoptosis of the TBI model. It also caused the corresponding changes in CASP3 activity and other apoptosis factors, with cleaved CASP3, BAX and PTEN inhibited and BCL2 and phosphorylated AKT1 promoted, while miR-22 antagomir had the opposite effects. So miR-22 has neuroprotective roles of attenuating neuronal cell injury and apoptosis induced by TBI, which may be associated with its regulation on apoptosis factors. This study reveals miR-22 as a potential approach to TBI treatment and detailed mechanism remains to be uncovered. PMID:27186313

  11. Suppression of ICE and Apoptosis in Mammary Epithelial Cells by Extracellular Matrix

    SciTech Connect

    Boudreau, Nancy; Sympson, C. J.; Werb, Zena; Bissell, Mina J.

    1994-12-01

    Apoptosis (programmed cell death) plays a major role in development and tissue regeneration. Basement membrane extracellular matrix (ECM), but not fibronectin or collagen, was shown to suppress apoptosis of mammary epithelial cells in tissue culture and in vivo. Apoptosis was induced by antibodies to beta 1 integrins or by overexpression of stromelysin-1, which degrades ECM. Expression of interleukin-1 beta converting enzyme (ICE) correlated with the loss of ECM, and inhibitors of ICE activity prevented apoptosis. These results suggest that ECM regulates apoptosis in mammary epithelial cells through an integrin-dependent negative regulation of ICE expression.

  12. Apoptosis and calcification of vascular endothelial cell under hyperhomocysteinemia.

    PubMed

    Fang, Kuaifa; Chen, Zhujun; Liu, Meng; Peng, Jian; Wu, Pingsheng

    2015-01-01

    In recent years, it is found that increase in Hcy level in blood can directly or indirectly cause vascular endothelial cell injury and induce vascular calcification. However, the mechanism of vascular endothelial cell injury and vascular calcification has not been studied thoroughly. This paper carried out experiment for research aiming at discussing the effect and action mechanism of Hhcy on endothelial cells and vascular calcification. Firstly, human umbilical vein endothelial cells (HUVECs) were cultured and then intervened by Hcy of different concentrations (0, 0.01, 0.1, 1.0, 3.0, 5.0 mmol/L) and at different action time (3, 6, 12, 24 h). Then apoptosis rate and reactive oxygen were detected by flow cytometry. At the same time, the model for the culture of rat vascular calcification was set up and induced into Hhcy so as to detect the total plasma Hcy level and judge vascular calcification degree. The results showed that with the increase in Hcy concentration and extension of action period, the apoptosis rate and generation of reactive oxygen of HUVECs all significantly increased, and the differences were all statistically significant (P < 0.01). In animal calcification model, mass of black particle deposition was seen after Von Kossa staining of rat vessels in calcification group. Compared with the control group, the vascular calcium content, alkaline phosphatase activity and osteocalcin content in calcification group all increased (P < 0.01). The content of plasma lipid conjugated olefine from highest to lowest wasas follows: calcification plus homoetheionin, homoetheionin, and calcification group. There was no significant difference between the calcification group and control group. All these findings suggested that Hcy could induce the apoptosis of endothelial cells and its effect degree depended on its concentration and action period; Hhcy could promote the calcification of blood vessels, and its mechanism might relate with the strengthening of

  13. Apoptosis Induction in Cancer Cells by Ultrasound Exposure

    NASA Astrophysics Data System (ADS)

    Watanabe, Akihiro; Kawai, Kazuaki; Sato, Toshio; Nishimura, Hiroyuki; Kawashima, Norimichi; Takeuchi, Shinichi

    2004-05-01

    The methods of suppressing cancer cell proliferation by ultrasound exposure were investigated to develop a new minimally invasive cancer treatment. A stainless-steel diaphragm with a bolt-clamped Langevin-type transducer (BLT) was attached to the bottom of a water tank in the ultrasound exposure system used in this study. Cancer cells of a mouse T lymphoma (EL-4) in a flask were exposed to ultrasound under various conditions of exposure time, ultrasound frequency, ultrasound waveform, and so forth. The number of cancer cells exposed to ultrasound decreased during the culturing process. In this study, it was proved by electrophoresis, enzyme activity measurement and morphological observation that cancer cell proliferation can be suppressed by apoptosis induction in cancer cells by ultrasound exposure.

  14. Saving cells from ultrasound-induced apoptosis: quantification of cell death and uptake following sonication and effects of targeted calcium chelation

    PubMed Central

    Hutcheson, J.D.; Schlicher, R.K.; Hicks, H.K.; Prausnitz, M.R.

    2010-01-01

    Applications of ultrasound for non-invasive drug and gene delivery have been limited by associated cell death due to sonication. In this study, we sought to quantify the distribution of cellular bioeffects caused by low-frequency ultrasound (24 kHz) and test the hypothesis that Ca2+ chelation after sonication can shift this distribution by saving cells from death by apoptosis. Using flow cytometry, we quantitatively categorized sonicated cells among four populations: (1) cells that appear largely unaffected, (2) cells reversibly permeabilized, (3) cells rendered nonviable during sonication and (4) cells that appear to be viable shortly after sonication, but later undergo apoptosis and die. By monitoring cells for 6 h after ultrasound exposure, we found that up to 15% of intact cells fell into this final category. Those apoptotic cells initially had the highest levels of uptake of a marker compound, calcein; also had highly elevated levels of intracellular Ca2+; and contained an estimated plasma membrane wound radius of 100 – 300 nm. Finally, we showed that chelation of intracellular Ca2+ after sonication reduced apoptosis by up to 44%, thereby providing a strategy to save cells. We conclude that cells can be saved from ultrasound-induced death by appropriate selection of ultrasound conditions and Ca2+ chelation after sonication. PMID:20447754

  15. Vanadium induced ultrastructural changes and apoptosis in male germ cells.

    PubMed

    Aragón, M A; Ayala, M E; Fortoul, T I; Bizarro, P; Altamirano-Lozano, M

    2005-01-01

    Vanadium is a transition metal that is emitted to the atmosphere during combustion of fossil fuels. In the environment, vanadium occurs in the (V) oxidized form, but in the body it is found exclusively in the (IV) oxidized form. Vanadium tetraoxide is an inorganic chemical species in the (IV) oxidized form that has been shown to induce toxic effects in vitro and in vivo. The reproductive toxicity of vanadium in males was studied through monitoring germ cell apoptosis during spermatogenesis. We analyzed ultrastructural damage, and testosterone and progesterone concentrations following vanadium tetraoxide administered to male mice for 60 days. Spermatogenesis stages I-III and X-XII frequently showed apoptotic germ cells in control and treated animals; vanadium tetraoxide treatment induced an increase in the number of germ cell apoptosis in stages I-III and XII at 9.4 and 18.8 mg/kg, respectively. Although spermatogenesis is regulated by testosterone, in our study this hormone level was not modified by vanadium administration; thus, germ cell death was not related with testosterone concentration. At the ultrastructural level, we observed inclusion structures that varied as to location and content in the Sertoli and germ cells. PMID:15808796

  16. Reversine Induced Multinucleated Cells, Cell Apoptosis and Autophagy in Human Non-Small Cell Lung Cancer Cells

    PubMed Central

    Lin, Ching-Yen; Chen, Yih-Yuan; Chen, Ping-Tzu; Tseng, Ya-Shih

    2016-01-01

    Reversine, an A3 adenosine receptor antagonist, has been shown to induce differentiated myogenic-lineage committed cells to become multipotent mesenchymal progenitor cells. We and others have reported that reversine has an effect on human tumor suppression. This study revealed anti-tumor effects of reversine on proliferation, apoptosis and autophagy induction in human non-small cell lung cancer cells. Treatment of these cells with reversine suppressed cell growth in a time- and dosage-dependent manner. Moreover, polyploidy occurred after reversine treatment. In addition, caspase-dependent apoptosis and activation of autophagy by reversine in a dosage-dependent manner were also observed. We demonstrated in this study that reversine contributes to growth inhibition, apoptosis and autophagy induction in human lung cancer cells. Therefore, reversine used as a potential therapeutic agent for human lung cancer is worthy of further investigation. PMID:27385117

  17. Tetrahydrocurcumin induces G2/M cell cycle arrest and apoptosis involving p38 MAPK activation in human breast cancer cells.

    PubMed

    Kang, Ning; Wang, Miao-Miao; Wang, Ying-Hui; Zhang, Zhe-Nan; Cao, Hong-Rui; Lv, Yuan-Hao; Yang, Yang; Fan, Peng-Hui; Qiu, Feng; Gao, Xiu-Mei

    2014-05-01

    Curcumin (CUR) is a major naturally-occurring polyphenol of Curcuma species, which is commonly used as a yellow coloring and flavoring agent in foods. In recent years, it has been reported that CUR exhibits significant anti-tumor activity in vivo. However, the pharmacokinetic features of CUR have indicated poor oral bioavailability, which may be related to its extensive metabolism. The CUR metabolites might be responsible for the antitumor pharmacological effects in vivo. Tetrahydrocurcumin (THC) is one of the major metabolites of CUR. In the present study, we examined the efficacy and associated mechanism of action of THC in human breast cancer MCF-7 cells for the first time. Here, THC exhibited significant cell growth inhibition by inducing MCF-7 cells to undergo mitochondrial apoptosis and G2/M arrest. Moreover, co-treatment of MCF-7 cells with THC and p38 MAPK inhibitor, SB203580, effectively reversed the dissipation in mitochondrial membrane potential (Δψm), and blocked THC-mediated Bax up-regulation, Bcl-2 down-regulation, caspase-3 activation as well as p21 up-regulation, suggesting p38 MAPK might mediate THC-induced apoptosis and G2/M arrest. Taken together, these results indicate THC might be an active antitumor form of CUR in vivo, and it might be selected as a potentially effective agent for treatment of human breast cancer. PMID:24593988

  18. β-Arrestin1 inhibits chemotherapy-induced intestinal stem cell apoptosis and mucositis.

    PubMed

    Zhan, Y; Xu, C; Liu, Z; Yang, Y; Tan, S; Yang, Y; Jiang, J; Liu, H; Chen, J; Wu, B

    2016-01-01

    The mechanism of chemotherapy-induced gastrointestinal (GI) syndrome (CIGIS) is still controversial, and it is unclear whether chemotherapy induces intestinal stem cell (ISC) apoptosis. β-Arrestins are regulators and mediators of G protein-coupled receptor signaling in cell apoptosis, division and growth. In this study, we aimed to investigate whether chemotherapy induces ISC apoptosis to contribute to mucositis in CIGIS and whether β-arrestin1 (β-arr1) is involved in this apoptosis. Different chemotherapeutic agents were used to generate a CIGIS model. Lgr5-EGFP-IRES-creERT2(+/-) knock-in mice were used as a CIGIS model to investigate ISC apoptosis. β-arr1 knockout mice were used to determine whether β-arr1 is involved in the apoptosis in CIGIS. Intestinal histology was performed, the ISC apoptosis was analyzed and the mucosal barrier was examined. The effects of β-arr1 in apoptosis were investigated in the samples from humans and mice as well as in cell lines. Here, we demonstrate that chemotherapy induced intestinal mucositis by promoting crypt cell apoptosis, especially in Lgr5+ stem cells and Paneth cells but not in goblet cells, epithelial cells or vascular endothelial cells. Furthermore, β-arr1 deficiency exacerbated the Lgr5+ stem cell apoptosis, but not Paneth cell apoptosis, in CIGIS. In addition, the data showed that β-arr1 reduced the chemotherapy-induced Lgr5+ stem cell apoptosis by inhibiting endoplasmic reticulum stress-mediated mitochondrial apoptotic signaling. Our study indicates that β-arr1 inhibits chemotherapy-induced ISC apoptosis to alleviate intestinal mucositis in CIGIS. PMID:27195676

  19. β-Arrestin1 inhibits chemotherapy-induced intestinal stem cell apoptosis and mucositis

    PubMed Central

    Zhan, Y; Xu, C; Liu, Z; Yang, Y; Tan, S; Yang, Y; Jiang, J; Liu, H; Chen, J; Wu, B

    2016-01-01

    The mechanism of chemotherapy-induced gastrointestinal (GI) syndrome (CIGIS) is still controversial, and it is unclear whether chemotherapy induces intestinal stem cell (ISC) apoptosis. β-Arrestins are regulators and mediators of G protein-coupled receptor signaling in cell apoptosis, division and growth. In this study, we aimed to investigate whether chemotherapy induces ISC apoptosis to contribute to mucositis in CIGIS and whether β-arrestin1 (β-arr1) is involved in this apoptosis. Different chemotherapeutic agents were used to generate a CIGIS model. Lgr5-EGFP-IRES-creERT2+/− knock-in mice were used as a CIGIS model to investigate ISC apoptosis. β-arr1 knockout mice were used to determine whether β-arr1 is involved in the apoptosis in CIGIS. Intestinal histology was performed, the ISC apoptosis was analyzed and the mucosal barrier was examined. The effects of β-arr1 in apoptosis were investigated in the samples from humans and mice as well as in cell lines. Here, we demonstrate that chemotherapy induced intestinal mucositis by promoting crypt cell apoptosis, especially in Lgr5+ stem cells and Paneth cells but not in goblet cells, epithelial cells or vascular endothelial cells. Furthermore, β-arr1 deficiency exacerbated the Lgr5+ stem cell apoptosis, but not Paneth cell apoptosis, in CIGIS. In addition, the data showed that β-arr1 reduced the chemotherapy-induced Lgr5+ stem cell apoptosis by inhibiting endoplasmic reticulum stress-mediated mitochondrial apoptotic signaling. Our study indicates that β-arr1 inhibits chemotherapy-induced ISC apoptosis to alleviate intestinal mucositis in CIGIS. PMID:27195676

  20. A methylene chloride fraction of Saururus chinensis induces apoptosis through the activation of caspase-3 in prostate and breast cancer cells.

    PubMed

    Kim, Han-Young; Choi, Tae Won; Kim, Hyun Jung; Kim, Sung-Moo; Park, Kyung-Ran; Jang, Hyeung-Jin; Lee, Eun Ha; Kim, Chul Young; Jung, Sang Hoon; Shim, Bum Sang; Ahn, Kwang Seok

    2011-05-15

    The aerial parts of Saururus chinensis (SC) have been used for the treatment of edema, fever, jaundice, and inflammatory diseases in Korean folk medicine for centuries. However, the mechanism by which SC exerts these anti-tumorigenic activities in human prostate and breast cancer cells has not yet been fully understood. In this study, we report on the methylene chloride fraction from SC exerting cytotoxicity against prostate and breast cancer cells in a dose-dependent manner. Specifically, SC exerted the most potent cytotoxicity in LNCaP and MCF-7 cells. SC was shown to down-regulate various angiogenetic (VEGF), proliferative (Cyclin D₁, anti-apoptotic (Bcl-2) gene products in these cells. SC also increased the number of annexin V-positive apoptotic bodies and the sub-G1 DNA contents of the cell cycle undergoing apoptosis through caspase-3 activation in both LNCaP and MCF-7 cells. We further confirmed that caspase-3 plays an important role in SC-induced apoptosis in LNCaP and MCF-7 cells through the use of the caspase-3 inhibitor. Moreover, we observed that SC potentiated paclitaxel-induced apoptosis in MCF-7 cells and sauchinone is a major active constituent of SC, which could induce apoptosis in the cells. Taken together, our data provide the evidence that SC induces apoptosis depending on caspase-3 activation and overcomes the natural biological resistance to chemotherapy found in human prostate and breast cancer cells. PMID:21111586

  1. [The origin of eukaryotic cells and origination of apoptosis].

    PubMed

    Galitskiĭ, V A

    2005-01-01

    The unified conception of the origin of eukaryotic cells has been proposed. In the author's opinion, evolutionary transformation of prokaryotic cell into eukaryotic cell took place 3.3-1.4 billion years ago and involved the next four stages: 1) the appearance of intracellular membranes due to prokaryotic cell plasmalemma invaginating into its cytoplasm; 2) the cell nucleus formation by the double sheet of intracellular membrane surrounding and sequestrating genetic material of the cell; 3) the appearance of cytoskeleton in parallel with mitotic spindle formation and gradual transition from prokaryotic way of cell division to mitosis; 4) the establishment of symbiosis between the evolving nucleated cell and prokaryotic microorganicsms that subsequently transform into mitochondria and chloroplasts. Apoptosis of cells of the present day multicellular eukaryotic organisms is supposed to be an evolutionary altered response of mitochondrian predecessors to the influence of factors, which are able to damage eukaryotic host cell. The initial biological significance of this reaction pertained to attempts of endosymbionts to leave the host cell as soon as possible, if the probability of its irreversible injury was very high, and by this to escape from their death. It is possible that numerous proteins, known as sensors or transducers of proapoptotic signals in Bcl-2--p53-dependent apoptotic pathway, were initially encoded by mitochondrial genome, whereas antiapoptotic factors and also components of receptor-mediated and granzyme B perforin dependent apoptotic pathways have cellular origin. PMID:16706173

  2. Cytokines and Mycobacterium leprae induce apoptosis in human Schwann cells.

    PubMed

    Oliveira, Rosane B; Sampaio, Elizabeth P; Aarestrup, Fernando; Teles, Rosane M B; Silva, Tatiana P; Oliveira, Ariane L; Antas, Paulo R Z; Sarno, Euzenir N

    2005-10-01

    The development of deformities during the course of leprosy disease is a major public health concern worldwide. It is possible that cytokine production and apoptosis of Schwann cells (SCs) directly affect nerve degeneration and regeneration leading to injury of the myelin sheath and axon. In the present study, the expression of TNFalpha, TGFbeta, and their receptors, in addition to cell death triggered by cytokines or whole Mycobacterium leprae were investigated in a human SC line. The results showed the presence of TNF-Rs and TGF-RII on the SC membrane and the shedding of TNF-Rs during the culture period. Evaluation of cell death was performed through TUNEL and flow cytometry techniques. TNFalpha/TGFbeta combination as well as M. leprae infection triggered an increase in the apoptosis rate in the cultured SC. Moreover, reverse transcriptase-polymerase chain reaction assay revealed that M. leprae upregulated the expression of such cytokines and their receptors on the SC line. Despite the detection of TNFalpha mRNA, no protein was found in the culture supernatants. The data indicate that induction of SC death after cell interaction with M. leprae may, in fact, be implicated in the pathogenesis of nerve damage, which can most likely be modulated by in vivo cytokine production. PMID:16215460

  3. Aloe-emodin-induced apoptosis in human gastric carcinoma cells.

    PubMed

    Chen, Sheng-Hsuan; Lin, Kai-Yuan; Chang, Chun-Chao; Fang, Chia-Lang; Lin, Chih-Ping

    2007-11-01

    The purpose of this study was to investigate the anticancer effect of aloe-emodin, an anthraquinone compound present in the leaves of Aloe vera, on two distinct human gastric carcinoma cell lines, AGS and NCI-N87. We demonstrate that aloe-emodin induced cell death in a dose- and time-dependent manner. Noteworthy is that the AGS cells were generally more sensitive than the NCI-N87 cells. Aloe-emodin caused the release of apoptosis-inducing factor and cytochrome c from mitochondria, followed by the activation of caspase-3, leading to nuclear shrinkage and apoptosis. In addition, exposure to aloe-emodin suppressed the casein kinase II activity in a time-dependent manner and was accompanied by a reduced phosphorylation of Bid, a downstream substrate of casein kinase II and a pro-apoptotic molecule. These preclinical studies suggest that aloe-emodin represents a suitable and novel chemotherapeutic drug candidate for the treatment of human gastric carcinoma. PMID:17637488

  4. Citral inhibits cell proliferation and induces apoptosis and cell cycle arrest in MCF-7 cells.

    PubMed

    Chaouki, Wahid; Leger, David Y; Liagre, Bertrand; Beneytout, Jean-Louis; Hmamouchi, Mohamed

    2009-10-01

    Many natural components of plants extract are studied for their beneficial effects on health and particularly on carcinogenesis chemoprevention. In this study, we investigated the effect of citral (3,7-dimethyl-2,6-octadienal), a key component of essential oils extracted from several herbal plants, on the proliferation rate, cell cycle distribution, and apoptosis of the human breast cancer cell line MCF-7. The effects of this compound were also tested on cyclo-oxygenase activity. Citral treatment caused inhibition of MCF-7 cell growth (IC(50)-48 h: 18 x 10(-5)m), with a cycle arrest in G(2)/M phase and apoptosis induction. Moreover, we observed a decrease in prostaglandin E(2) synthesis 48 h after citral treatment. These findings suggest that citral has a potential chemopreventive effect. PMID:19656204

  5. 5-Ene-4-thiazolidinones induce apoptosis in mammalian leukemia cells.

    PubMed

    Senkiv, Julia; Finiuk, Nataliya; Kaminskyy, Danylo; Havrylyuk, Dmytro; Wojtyra, Magdalena; Kril, Iryna; Gzella, Andrzej; Stoika, Rostyslav; Lesyk, Roman

    2016-07-19

    The article presents the synthesis of 5-ene-4-thiazolidinone derivatives with pyrazole core linked by enamine group. The structure and purity of compounds were confirmed by analytical and spectral data including X-ray analysis. Target compounds were screened for their anticancer activity and selective antileukemic action was confirmed. 5-[5-(2-Hydroxyphenyl)-3-phenyl-4,5-dihydropyrazol-1-ylmethylene]-3-(3-acetoxyphenyl)-2-thioxothiazolidin-4-one (compound 1) was selected as most active agent against HL-60 and HL-60/ADR cell lines; IC50 = 118 nM/HL-60 with low toxicity towards pseudonormal cells. The mitochondria-depended apoptosis was identified as the main mode of 1 action. Moreover compound's effect induces G0/G1 arrest of the treated cells and causes inhibition of cell division and is related with activation of ROS production. PMID:27089210

  6. Anticancer effect of arsenite on cell migration, cell cycle and apoptosis in human pancreatic cancer cells

    PubMed Central

    HORIBE, YOHEI; ADACHI, SEIJI; YASUDA, ICHIRO; YAMAUCHI, TAKAHIRO; KAWAGUCHI, JUNJI; KOZAWA, OSAMU; SHIMIZU, MASAHITO; MORIWAKI, HISATAKA

    2016-01-01

    The standard treatment for advanced pancreatic cancer is chemotherapy, but its clinical outcome remains unsatisfactory. Therefore, the development of novel treatments for this malignancy is urgently required. In the present study, the anticancer effect of arsenite on platelet-derived growth factor (PDGF)-BB-induced migration, cell cycle and apoptosis was investigated in pancreatic cancer cells (AsPC-1 and BxPC-3), and compared with the effect on normal pancreatic epithelial (PE) cells. In the cell migration assay, arsenite clearly inhibited PDGF-BB-induced cell migration in AsPC-1 cells, but not in BxPC-3 or PE cells. Arsenite also caused cell apoptosis in AsPC-1 cells, but not in BxPC-3 or PE cells. In AsPC-1 cells, the levels of cyclin D1 and phosphorylated retinoblastoma protein decreased following treatment with arsenite, but this was not observed in BxPC-3 cells. To further examine the differences between these two cell lines, the effect of arsenite on upstream p44/p42 mitogen-activated protein kinase (MAPK) and Akt was investigated. PDGF-BB caused phosphorylation of p44/p42 MAPK and Akt in both cell lines. Pretreatment with arsenite significantly suppressed PDGF-BB-induced phosphorylation of Akt, but not of p44/p42 MAPK in AsPC-1 cells. By contrast, arsenite did not affect these molecules in BxPC-3 cells. Since the inhibition of the Akt signaling pathway markedly reduced PDGF-BB-induced migration in AsPC-1 cells, the present results strongly suggest that arsenite inhibits PDGF-BB-induced migration by suppressing the Akt signaling pathway in AsPC-1 cells. Therefore, arsenite may be a useful tool for the treatment of patients with certain types of pancreatic cancer, without causing adverse effects on normal pancreatic cells. PMID:27347121

  7. Salidroside induces cell-cycle arrest and apoptosis in human breast cancer cells

    SciTech Connect

    Hu, Xiaolan; Zhang, Xianqi; Qiu, Shuifeng; Yu, Daihua; Lin, Shuxin

    2010-07-16

    Research highlights: {yields} Salidroside inhibits the growth of human breast cancer cells. {yields} Salidroside induces cell-cycle arrest of human breast cancer cells. {yields} Salidroside induces apoptosis of human breast cancer cell lines. -- Abstract: Recently, salidroside (p-hydroxyphenethyl-{beta}-D-glucoside) has been identified as one of the most potent compounds isolated from plants of the Rhodiola genus used widely in traditional Chinese medicine, but pharmacokinetic data on the compound are unavailable. We were the first to report the cytotoxic effects of salidroside on cancer cell lines derived from different tissues, and we found that human breast cancer MDA-MB-231 cells (estrogen receptor negative) were sensitive to the inhibitory action of low-concentration salidroside. To further investigate the cytotoxic effects of salidroside on breast cancer cells and reveal possible ER-related differences in response to salidroside, we used MDA-MB-231 cells and MCF-7 cells (estrogen receptor-positive) as models to study possible molecular mechanisms; we evaluated the effects of salidroside on cell growth characteristics, such as proliferation, cell cycle duration, and apoptosis, and on the expression of apoptosis-related molecules. Our results demonstrated for the first time that salidroside induces cell-cycle arrest and apoptosis in human breast cancer cells and may be a promising candidate for breast cancer treatment.

  8. Loss of Drosophila pseudouridine synthase triggers apoptosis-induced proliferation and promotes cell-nonautonomous EMT

    PubMed Central

    Vicidomini, R; Di Giovanni, A; Petrizzo, A; Iannucci, L F; Benvenuto, G; Nagel, A C; Preiss, A; Furia, M

    2015-01-01

    Many developing tissues display regenerative capability that allows them to compensate cell loss and preserve tissue homeostasis. Because of their remarkable regenerative capability, Drosophila wing discs are extensively used for the study of regenerative phenomena. We thus used the developing wing to investigate the role played in tissue homeostasis by the evolutionarily conserved eukaryotic H/ACA small nucleolar ribonucleoprotein pseudouridine synthase. Here we show that localized depletion of this enzyme can act as an endogenous stimulus capable of triggering apoptosis-induced proliferation, and that context-dependent effects are elicited in different sub-populations of the silenced cells. In fact, some cells undergo apoptosis, whereas those surrounding the apoptotic foci, although identically depleted, overproliferate. This overproliferation correlates with ectopic induction of the Wg and JAK-STAT (Janus kinase-signal transducer and activator of transcription) mitogenic pathways. Expression of a p35 transgene, which blocks the complete execution of the death program and generates the so-called ‘undead cells', amplifies the proliferative response. Pseudouridine synthase depletion also causes loss of apicobasal polarity, disruption of adherens cell junctions and ectopic induction of JNK (c-Jun N-terminal kinase) and Mmp1 (matrix metalloproteinase-1) activity, leading to a significant epithelial reorganization. Unexpectedly, cell-nonautonomous effects, such as epithelial mesenchymal transition in the contiguous unsilenced squamous epithelium, are also promoted. Collectively, these data point out that cell–cell communication and long-range signaling can take a relevant role in the response to pseudouridine synthase decline. Considering that all the affected pathways are highly conserved throughout evolution, it is plausible that the response to pseudouridine synthase depletion has been widely preserved. On this account, our results can add new light on the

  9. Apoptosis, paraptosis, necrosis, and cell regeneration in posttraumatic cerebral arteries.

    PubMed

    Danaila, L; Popescu, I; Pais, V; Riga, D; Riga, S; Pais, E

    2013-01-01

    This study is to understand the nature and functional significance of the activated cell death programs and rehabilitation signs during late vascular changes after brain injury. We used light and transmission electron microscopy to describe changes of cells within the vascular endothelium and tunica media of the cortical arteries four weeks after craniocerebral traumatism. Within tunica media of the posttraumatic damaged artery, apoptotic and paraptotic phenotypes were identified as well as some early ultrastructural signs of smooth muscle cells regeneration, these cell highlighting a remarkable degree of plasticity. Surprisingly, some endothelial cells showed an extensive rough endoplasmic reticulum development, whereas other endothelial cells showed typical necrosis. In conclusion, two groups of suicidal cells apoptotic and paraptotic cells were encountered in the same lesional vascular wall after neurotrauma, showing also signs of cell regeneration. The pathophysiologic significance of the coexisting double cell death programs and cell regeneration seems to be in relation with late cell survival, after arterial damage when some cells disappear and other cells try to survive undergoing reversible injury. PMID:23790779

  10. Anemone altaica Induces Apoptosis in Human Osteosarcoma Cells.

    PubMed

    Chang, I-Chang; Chiang, Tsay-I; Lo, Chun; Lai, Yi-Hua; Yue, Chia-Herng; Liu, Jer-Yuh; Hsu, Li-Sung; Lee, Chia-Jen

    2015-01-01

    In the past decade, no significant improvement has been made in chemotherapy for osteosarcoma (OS). To develop improved agents against OS, we screened 70 species of medicinal plants and treated two human OS cell lines with different agent concentrations. We then examined cell viability using the MTT assay. Results showed that a candidate plant, particularly the rhizomes of Anemone altaica Fisch. ex C. A. Mey aqueous extract (AAE), suppressed the viability of HOS and U2OS cells in a concentration-dependent manner. Flow cytometry analysis revealed that AAE significantly increased the amount of cell shrinkage (Sub-G1 fragments) in HOS and U2OS cells. Moreover, AAE increased cytosolic cytochrome c and Bax, but decreased Bcl-2. The amount of cleaved caspase-3 and poly-(ADP-ribose) polymerase-1 (PARP-1) were significantly increased. AAE suppressed the growth of HOS and U2OS through the intrinsic apoptotic pathway. Data suggest that AAE is cytotoxic to HOS and U2OS cells and has no significant influence on human osteoblast hFOB cells. The high mRNA levels of apoptosis-related factors (PPP1R15A, SQSTM1, HSPA1B, and DDIT4) and cellular proliferation markers (SKA2 and BUB1B) were significantly altered by the AAE treatment of HOS and U2OS cells. Results show that the anticancer activity of AAE could up-regulate the expression of a cluster of genes, especially those in the apoptosis-related factor family and caspase family. Thus, AAE has great potential as a useful therapeutic drug for human OS. PMID:26224029

  11. Polydatin inhibits growth of lung cancer cells by inducing apoptosis and causing cell cycle arrest.

    PubMed

    Zhang, Yusong; Zhuang, Zhixiang; Meng, Qinghui; Jiao, Yang; Xu, Jiaying; Fan, Saijun

    2014-01-01

    Polydatin (PD), a small natural compound from Polygonum cuspidatum, has a number of biological functions. However, the anticancer activity of PD has been poorly investigated. In the present study, thiazolyl blue tetrazolium bromide assay was used to evaluate the inhibitory effect of PD on cell growth. Cell cycle distribution and apoptosis were investigated by flow cytometry. In addition, the expression of several proteins associated with apoptosis and cell cycle were analyzed by western blot analysis. The results demonstrated that PD significantly inhibits the proliferation of A549 and NCI-H1975 lung cancer cell lines and causes dose-dependent apoptosis. Cell cycle analysis revealed that PD induces S phase cell cycle arrest. Western blot analysis showed that the expression of Bcl-2 decreased as that of Bax increased, and the expression of cyclin D1 was also suppressed. The results suggest that PD has potential therapeutic applications in the treatment of lung cancer. PMID:24348867

  12. Mitophagy switches cell death from apoptosis to necrosis in NSCLC cells treated with oncolytic measles virus.

    PubMed

    Xia, Mao; Meng, Gang; Jiang, Aiqin; Chen, Aiping; Dahlhaus, Meike; Gonzalez, Patrick; Beltinger, Christian; Wei, Jiwu

    2014-06-15

    Although apoptotic phenomena have been observed in malignant cells infected by measles virus vaccine strain Edmonston B (MV-Edm), the precise oncolytic mechanisms are poorly defined. In this study we found that MV-Edm induced autophagy and sequestosome 1-mediated mitophagy leading to decreased cytochrome c release, which blocked the pro-apoptotic cascade in non-small cell lung cancer cells (NSCLCs). The decrease of apoptosis by mitophagy favored viral replication. Persistent viral replication sustained by autophagy ultimately resulted in necrotic cell death due to ATP depletion. Importantly, when autophagy was impaired in NSCLCs MV-Edm-induced cell death was significantly abrogated despite of increased apoptosis. Taken together, our results define a novel oncolytic mechanism by which mitophagy switches cell death from apoptosis to more efficient necrosis in NSCLCs following MV-Edm infection. This provides a foundation for future improvement of oncolytic virotherapy or antiviral therapy. PMID:25004098

  13. Mechanisms of cyclic AMP/protein kinase A- and glucocorticoid-mediated apoptosis using S49 lymphoma cells as a model system

    PubMed Central

    Keshwani, Malik M.; Kanter, Joan R.; Ma, Yuliang; Wilderman, Andrea; Darshi, Manjula; Insel, Paul A.; Taylor, Susan S.

    2015-01-01

    Cyclic AMP/protein kinase A (cAMP/PKA) and glucocorticoids promote the death of many cell types, including cells of hematopoietic origin. In wild-type (WT) S49 T-lymphoma cells, signaling by cAMP and glucocorticoids converges on the induction of the proapoptotic B-cell lymphoma-family protein Bim to produce mitochondria-dependent apoptosis. Kin–, a clonal variant of WT S49 cells, lacks PKA catalytic (PKA-Cα) activity and is resistant to cAMP-mediated apoptosis. Using sorbitol density gradient fractionation, we show here that in kin– S49 cells PKA-Cα is not only depleted but the residual PKA-Cα mislocalizes to heavier cell fractions and is not phosphorylated at two conserved residues (Ser338 or Thr197). In WT S49 cells, PKA-regulatory subunit I (RI) and Bim coimmunoprecipitate upon treatment with cAMP analogs and forskolin (which increases endogenous cAMP concentrations). By contrast, in kin– cells, expression of PKA-RIα and Bim is prominently decreased, and increases in cAMP do not increase Bim expression. Even so, kin– cells undergo apoptosis in response to treatment with the glucocorticoid dexamethasone (Dex). In WT cells, glucorticoid-mediated apoptosis involves an increase in Bim, but in kin– cells, Dex-promoted cell death appears to occur by a caspase 3-independent apoptosis-inducing factor pathway. Thus, although cAMP/PKA-Cα and PKA-R1α/Bim mediate apoptotic cell death in WT S49 cells, kin– cells resist this response because of lower levels of PKA-Cα and PKA-RIα subunits as well as Bim. The findings for Dex-promoted apoptosis imply that these lymphoma cells have adapted to selective pressure that promotes cell death by altering canonical signaling pathways. PMID:26417071

  14. Raman spectrum reveals the cell cycle arrest of Triptolide-induced leukemic T-lymphocytes apoptosis

    NASA Astrophysics Data System (ADS)

    Zhang, Daosen; Feng, Yanyan; Zhang, Qinnan; Su, Xin; Lu, Xiaoxu; Liu, Shengde; Zhong, Liyun

    2015-04-01

    Triptolide (TPL), a traditional Chinese medicine extract, possesses anti-inflammatory and anti-tumor properties. Though some research results have implicated that Triptolide (TPL) can be utilized in the treatment of leukemia, it remains controversial about the mechanism of TPL-induced leukemic T-lymphocytes apoptosis. In this study, combining Raman spectroscopic data, principal component analysis (PCA) and atomic force microscopy (AFM) imaging, both the biochemical changes and morphological changes during TPL-induced cell apoptosis were presented. In contrast, the corresponding data during Daunorubicin (DNR)-induced cell apoptosis was also exhibited. The obtained results showed that Raman spectral changes during TPL-induced cell apoptosis were greatly different from DNR-induced cell apoptosis in the early stage of apoptosis but revealed the high similarity in the late stage of apoptosis. Moreover, above Raman spectral changes were respectively consistent with the morphological changes of different stages during TPL-induced apoptosis or DNR-induced apoptosis, including membrane shrinkage and blebbing, chromatin condensation and the formation of apoptotic bodies. Importantly, it was found that Raman spectral changes with TPL-induced apoptosis or DNR-induced apoptosis were respectively related with the cell cycle G1 phase arrest or G1 and S phase arrest.

  15. Involvement of the Up-regulated FoxO1 Expression in Follicular Granulosa Cell Apoptosis Induced by Oxidative Stress*

    PubMed Central

    Shen, Ming; Lin, Fei; Zhang, Jiaqing; Tang, Yiting; Chen, Wei-Kang; Liu, Honglin

    2012-01-01

    Follicular atresia is common in female mammalian ovaries, where most follicles undergo degeneration at any stage of growth and development. Oxidative stress gives rise to triggering granulosa cell apoptosis, which has been suggested as a major cause of follicular atresia. However, the underlying mechanism by which the oxidative stress induces follicular atresia remains unclear. FoxO transcription factors are known as critical mediators in the regulation of oxidative stress and apoptosis. In this study, the involvement of FoxO1 in oxidative stress-induced apoptosis of mouse follicular granulosa cells (MGCs) was investigated in vivo and in vitro. It was observed that increased apoptotic signals correlated with elevated expression of FoxO1 in MGCs when mice were treated with the oxidant. Correspondingly, the expressions of FoxO1 target genes, such as proapoptotic genes and antioxidative genes, were also up-regulated. In primary cultured MGCs, treatment with H2O2 led to FoxO1 nuclear translocation. Further studies with overexpression and knockdown of FoxO1 demonstrated the critical role of FoxO1 in the induction of MGC apoptosis by oxidative stress. Finally, inactivation of FoxO1 by insulin treatment confirmed that FoxO1 induced by oxidative stress played a pivotal role in up-regulating the expression of downstream apoptosis-related genes in MGCs. Our results suggest that up-regulation of FoxO1 by oxidative stress leads to apoptosis of granulosa cells, which eventually results in follicular atresia in mice. PMID:22669940

  16. Linalool Induces Cell Cycle Arrest and Apoptosis in Leukemia Cells and Cervical Cancer Cells through CDKIs

    PubMed Central

    Chang, Mei-Yin; Shieh, Den-En; Chen, Chung-Chi; Yeh, Ching-Sheng; Dong, Huei-Ping

    2015-01-01

    Plantaginaceae, a popular traditional Chinese medicine, has long been used for treating various diseases from common cold to cancer. Linalool is one of the biologically active compounds that can be isolated from Plantaginaceae. Most of the commonly used cytotoxic anticancer drugs have been shown to induce apoptosis in susceptible tumor cells. However, the signaling pathway for apoptosis remains undefined. In this study, the cytotoxic effect of linalool on human cancer cell lines was investigated. Water-soluble tetrazolium salts (WST-1) based colorimetric cellular cytotoxicity assay, was used to test the cytotoxic ability of linalool against U937 and HeLa cells, and flow cytometry (FCM) and genechip analysis were used to investigate the possible mechanism of apoptosis. These results demonstrated that linalool exhibited a good cytotoxic effect on U937 and HeLa cells, with the IC50 value of 2.59 and 11.02 μM, respectively, compared with 5-FU with values of 4.86 and 12.31 μM, respectively. After treating U937 cells with linalool for 6 h, we found an increased sub-G1 peak and a dose-dependent phenomenon, whereby these cells were arrested at the G0/G1 phase. Furthermore, by using genechip analysis, we observed that linalool can promote p53, p21, p27, p16, and p18 gene expression. Therefore, this study verified that linalool can arrest the cell cycle of U937 cells at the G0/G1 phase and can arrest the cell cycle of HeLa cells at the G2/M phase. Its mechanism facilitates the expression of the cyclin-dependent kinases inhibitors (CDKIs) p53, p21, p27, p16, and p18, as well as the non-expression of cyclin-dependent kinases (CDKs) activity. PMID:26703569

  17. Treatment of mouse melanoma cells with phorbol 12-myristate 13-acetate counteracts mannosylerythritol lipid-induced growth arrest and apoptosis.

    PubMed

    Zhao, X; Geltinger, C; Kishikawa, S; Ohshima, K; Murata, T; Nomura, N; Nakahara, T; Yokoyama, K K

    2000-07-01

    Mannosylerythritol lipid (MEL), an extracellularglycolipid from yeast, induces the differentiation ofHL-60 promyelocytic leukemia cells towardsgranulocytes. We show here that MEL is also a potentinhibitor of the proliferation of mouse melanoma B16cells. Flow-cytometric analysis of the cell cycle ofMEL-treated B16 cells revealed the accumulation ofcells in the sub-G(0)/G(1) phase, which is a hallmark ofcells undergoing apoptosis. Treatment of B16 cellsfor 24 h with phorbol 12-myristate 13-acetate (PMA),an activator of protein kinase C (PKC), did notinterfere with the growth and survival of the cells,but it effectively counteracted the MEL-induced growtharrest and apoptosis. The activity of PKC was reducedin B16 cells treated with MEL at a concentration atwhich MEL induced apoptosis. However, incubation withPMA in addition to MEL reversed this reduction in theactivity of PKC. These results suggest thatconverging signaling pathways are triggeredindependently by MEL and PMA and that the signalsmight both be mediated by PKC. PMID:19002819

  18. Hrk/DP5 contributes to the apoptosis of select neuronal populations but is dispensable for haematopoietic cell apoptosis.

    PubMed

    Coultas, Leigh; Terzano, Susanna; Thomas, Tim; Voss, Anne; Reid, Kate; Stanley, Edouard G; Scott, Clare L; Bouillet, Philippe; Bartlett, Perry; Ham, Jonathan; Adams, Jerry M; Strasser, Andreas

    2007-06-15

    The pro-apoptotic BH3-only members of the Bcl2 family, crucial initiators of cell death, are activated by a diverse array of developmental cues or experimentally applied stress stimuli. We have investigated, through gene targeting in mice, the biological roles for the BH3-only family member HRK (also known as DP5) in apoptosis regulation. Hrk gene expression was found to be restricted to cells and tissues of the central and peripheral nervous systems. Sensory neurons from mice lacking Hrk were less sensitive to apoptosis induced by nerve growth factor (NGF) withdrawal, consistent with the induction of Hrk following NGF deprivation. By contrast, cerebellar granule neurons that upregulate Hrk upon transfer to low-K+ medium underwent apoptosis normally under these conditions in the absence of Hrk. Furthermore, loss of Hrk was not sufficient to rescue the neuronal degeneration in lurcher mutant mice. Despite previous reports, no evidence was found for Hrk expression or induction in growth-factor-dependent haematopoietic cell lines following withdrawal of their requisite cytokine, and haematopoietic progenitors lacking HRK died normally in response to cytokine deprivation. These results demonstrate that HRK contributes to apoptosis signalling elicited by trophic factor withdrawal in certain neuronal populations but is dispensable for apoptosis of haematopoietic cells. PMID:17535852

  19. Hrk/DP5 contributes to the apoptosis of select neuronal populations but is dispensable for haematopoietic cell apoptosis

    PubMed Central

    Coultas, Leigh; Terzano, Susanna; Thomas, Tim; Voss, Anne; Reid, Kate; Stanley, Edouard G.; Scott, Clare L.; Bouillet, Philippe; Bartlett, Perry; Ham, Jonathan; Adams, Jerry M.; Strasser, Andreas

    2009-01-01

    Summary The pro-apoptotic BH3-only members of the Bcl2 family, crucial initiators of cell death, are activated by a diverse array of developmental cues or experimentally applied stress stimuli. We have investigated, through gene targeting in mice, the biological roles for the BH3-only family member HRK (also known as DP5) in apoptosis regulation. Hrk gene expression was found to be restricted to cells and tissues of the central and peripheral nervous systems. Sensory neurons from mice lacking Hrk were less sensitive to apoptosis induced by nerve growth factor (NGF) withdrawal, consistent with the induction of Hrk following NGF deprivation. By contrast, cerebellar granule neurons that upregulate Hrk upon transfer to low-K+ medium underwent apoptosis normally under these conditions in the absence of Hrk. Furthermore, loss of Hrk was not sufficient to rescue the neuronal degeneration in lurcher mutant mice. Despite previous reports, no evidence was found for Hrk expression or induction in growth-factor-dependent haematopoietic cell lines following withdrawal of their requisite cytokine, and haematopoietic progenitors lacking HRK died normally in response to cytokine deprivation. These results demonstrate that HRK contributes to apoptosis signalling elicited by trophic factor withdrawal in certain neuronal populations but is dispensable for apoptosis of haematopoietic cells. PMID:17535852

  20. Regulation of cell proliferation and apoptosis by bioactive lipid mediators.

    PubMed

    Clària, Joan

    2006-11-01

    Bioactive lipid mediators are increasingly being recognized as important endogenous regulators of cell activation, signaling, apoptosis and proliferation. Most of these lipid mediators are originated from cleavage of constituents of cellular membranes under the activity of phospholipases and sphingomyelinases. One of the major cascades of bioactive lipid mediator production involves the release of arachidonic acid from membrane phospholipids followed by the formation of eicosanoids (i.e. prostaglandins, leukotrienes and lipoxins). These biologically active metabolites of arachidonic acid are emerging as key regulators of cell proliferation and neo-angiogenesis and agents that specifically target these lipid mediators are being investigated as potential anticancer drugs. On the other hand, the lysophospholipid family, which includes members of the sphingomyelin-ceramide-sphingosine-1-phosphate and lysophosphatidic acid subfamilies, has evolved as an important group of lipid signaling molecules implicated in cellular differentiation, cell growth and apoptosis. This article reviews the most recent patents in this field of research, covering the following strategies based on the modulation of bioactive lipid mediators: (1) prostaglandin H synthase-2 inhibitors, (2) lipoxin analogs and aspirin-triggered lipid mediators, and (3) lysophosphatidic acid and other lysophospholipids. PMID:18221047

  1. Physical contact with endothelial cells through β1- and β2- integrins rescues chronic lymphocytic leukemia cells from spontaneous and drug-induced apoptosis and induces a peculiar gene expression profile in leukemic cells

    PubMed Central

    Maffei, Rossana; Fiorcari, Stefania; Bulgarelli, Jenny; Martinelli, Silvia; Castelli, Ilaria; Deaglio, Silvia; Debbia, Giulia; Fontana, Marcella; Coluccio, Valeria; Bonacorsi, Goretta; Zucchini, Patrizia; Narni, Franco; Torelli, Giuseppe; Luppi, Mario; Marasca, Roberto

    2012-01-01

    Background Chronic lymphocytic leukemia B cells display prolonged survival in vivo, but when cultured in vitro rapidly undergo spontaneous apoptosis. We hypothesize that interactions with endothelial cells in infiltrated tissues and during recirculation may have a pathogenic role in chronic lymphocytic leukemia. Design and Methods We evaluated apoptosis of leukemic cells after co-culture on a monolayer of human umbilical vein endothelial cells with addition of fludarabine and antibodies that block adhesion. Then, we compared microarray-based gene expression profiles between leukemic cells at baseline and after co-culture. Results We found that the endothelial layer protected leukemic cells from apoptosis inducing a 2-fold mean decrement in apoptotic cells after 2 days of co-culture. Moreover, the endothelial layer decreased the sensitivity of chronic lymphocytic leukemia B cells to fludarabine-induced apoptosis. Physical contact with endothelium mediated by both β1- and β2- integrins is essential for the survival advantage of leukemic cells. In particular, blocking CD106 on endothelial cells or CD18 on leukemic B cells led to the almost complete abrogation of the survival advantage (>70% inhibition of viability). However, a reduction of apoptosis was also measured in leukemic cells cultured in conditioned medium collected after 2 days of co-culture, implying that survival is partially mediated by soluble factors. Overall, the contact with endothelial cells modulated 1,944 genes in chronic lymphocytic leukemia B cells, establishing a peculiar gene expression profile: up-regulation of angiogenesis-related genes, an increase of genes involved in TGFβ and Wnt signaling pathways, secretion of cytokines recruiting stromal cells and macrophages and up-regulation of anti-apoptotic molecules such as Bcl2 and Survivin. Conclusions Our study supports the notion that endothelial cells are major players in the chronic lymphocytic leukemia microenvironment. Adhesion to

  2. Maduramicin Inhibits Proliferation and Induces Apoptosis in Myoblast Cells

    PubMed Central

    Chen, Xin; Gu, Ying; Singh, Karnika; Shang, Chaowei; Barzegar, Mansoureh; Jiang, Shanxiang; Huang, Shile

    2014-01-01

    Maduramicin, a polyether ionophore antibiotic derived from the bacterium Actinomadura yumaensis, is currently used as a feed additive against coccidiosis in poultry worldwide. It has been clinically observed that maduramicin can cause skeletal muscle and heart cell damage, resulting in skeletal muscle degeneration, heart failure, and even death in animals and humans, if improperly used. However, the mechanism of its toxic action in myoblasts is not well understood. Using mouse myoblasts (C2C12) and human rhabdomyosarcoma (RD and Rh30) cells as an experimental model for myoblasts, here we found that maduramicin inhibited cell proliferation and induced cell death in a concentration-dependent manner. Further studies revealed that maduramicin induced accumulation of the cells at G0/G1 phase of the cell cycle, and induced apoptosis in the cells. Concurrently, maduramicin downregulated protein expression of cyclin D1, cyclin-dependent kinases (CDK4 and CDK6), and CDC25A, and upregulated expression of the CDK inhibitors (p21Cip1 and p27Kip1), resulting in decreased phosphorylation of Rb. Maduramicin also induced expression of BAK, BAD, DR4, TRADD and TRAIL, leading to activation of caspases 8, 9 and 3 as well as cleavage of poly ADP ribose polymerase (PARP). Taken together, our results suggest that maduramicin executes its toxicity in myoblasts at least by inhibiting cell proliferation and inducing apoptotic cell death. PMID:25531367

  3. Maduramicin inhibits proliferation and induces apoptosis in myoblast cells.

    PubMed

    Chen, Xin; Gu, Ying; Singh, Karnika; Shang, Chaowei; Barzegar, Mansoureh; Jiang, Shanxiang; Huang, Shile

    2014-01-01

    Maduramicin, a polyether ionophore antibiotic derived from the bacterium Actinomadura yumaensis, is currently used as a feed additive against coccidiosis in poultry worldwide. It has been clinically observed that maduramicin can cause skeletal muscle and heart cell damage, resulting in skeletal muscle degeneration, heart failure, and even death in animals and humans, if improperly used. However, the mechanism of its toxic action in myoblasts is not well understood. Using mouse myoblasts (C2C12) and human rhabdomyosarcoma (RD and Rh30) cells as an experimental model for myoblasts, here we found that maduramicin inhibited cell proliferation and induced cell death in a concentration-dependent manner. Further studies revealed that maduramicin induced accumulation of the cells at G0/G1 phase of the cell cycle, and induced apoptosis in the cells. Concurrently, maduramicin downregulated protein expression of cyclin D1, cyclin-dependent kinases (CDK4 and CDK6), and CDC25A, and upregulated expression of the CDK inhibitors (p21Cip1 and p27Kip1), resulting in decreased phosphorylation of Rb. Maduramicin also induced expression of BAK, BAD, DR4, TRADD and TRAIL, leading to activation of caspases 8, 9 and 3 as well as cleavage of poly ADP ribose polymerase (PARP). Taken together, our results suggest that maduramicin executes its toxicity in myoblasts at least by inhibiting cell proliferation and inducing apoptotic cell death. PMID:25531367

  4. VMP1 related autophagy and apoptosis in colorectal cancer cells: VMP1 regulates cell death

    SciTech Connect

    Qian, Qinyi; Zhou, Hao; Chen, Yan; Shen, Chenglong; He, Songbing; Zhao, Hua; Wang, Liang; Wan, Daiwei; Gu, Wen

    2014-01-17

    Highlights: •This research confirmed VMP1 as a regulator of autophagy in colorectal cancer cell lines. •We proved the pro-survival role of VMP1-mediated autophagy in colorectal cancer cell lines. •We found the interaction between VMP1 and BECLIN1 also existing in colorectal cancer cell lines. -- Abstract: Vacuole membrane protein 1 (VMP1) is an autophagy-related protein and identified as a key regulator of autophagy in recent years. In pancreatic cell lines, VMP1-dependent autophagy has been linked to positive regulation of apoptosis. However, there are no published reports on the role of VMP1 in autophagy and apoptosis in colorectal cancers. Therefore, to address this gap of knowledge, we decided to interrogate regulation of autophagy and apoptosis by VMP1. We have studied the induction of autophagy by starvation and rapamycin treatment in colorectal cell lines using electron microscopy, immunofluorescence, and immunoblotting. We found that starvation-induced autophagy correlated with an increase in VMP1 expression, that VMP1 interacted with BECLIN1, and that siRNA mediated down-regulation of VMP1-reduced autophagy. Next, we examined the relationship between VMP1-dependent autophagy and apoptosis and found that VMP1 down-regulation sensitizes cells to apoptosis and that agents that induce apoptosis down-regulate VMP1. In conclusion, similar to its reported role in other cell types, VMP1 is an important regulator of autophagy in colorectal cell lines. However, in contrast to its role in pancreatic cell lines, in colorectal cancer cells, VMP1-dependent autophagy appears to be pro-survival rather than pro-cell death.

  5. EB1089, a synthetic analogue of vitamin D, induces apoptosis in breast cancer cells in vivo and in vitro

    PubMed Central

    James, Sharon Y; Mercer, Elizabeth; Brady, Matthew; Binderup, Lise; Colston, Kay W

    1998-01-01

    Effects of the synthetic vitamin D analogue EB1089 on indices of apoptosis in cultured human breast cancer cells and in nitrosomethylurea-induced rat mammary tumours in vivo were investigated.At a dose of 0.5 μg kg−1 body weight, EB1089 caused significant inhibition of tumour progression over the 28 day treatment period in the absence of a significant increase in serum calcium concentration. Higher doses of EB1089 (1 and 2.5 μg kg−1) produced substantial regression of the experimental tumours which was accompanied by a striking change in the histological appearance of tumours consistent with induction of tumour cell death.Fragmentation of genomic DNA is a characteristic feature of apoptosis. With the terminal transferase (TdT) assay, 3′ DNA breaks indicative of DNA fragmentation were detected histochemically in mammary tumour cells from animals treated with EB1089 (2.5 μg kg−1) for 14 days.Effects of the vitamin D analogue on induction of apoptosis were examined in vitro using the MCF-7 human breast cancer cell line. Using the TUNEL method, positive nuclear staining indicative of DNA fragmentation was detected in cells treated for 4 days with 10 nM EB1089. Apoptosis was also quantitated using a cell death ELISA which revealed a time and dose dependent induction of apoptosis by EB1089.The effects of EB1089 on the expression of two oncoproteins which may regulate apoptosis, bcl-2 and bax were examined by Western analysis. In MCF-7 cell cultures treated with 1,25(OH)2D3 or EB1089 (1×10−8 M), bcl-2 protein levels were decreased in a time-dependent manner relative to control levels. In contrast bax protein was not markedly regulated by these compounds. Densitometric analyses indicate that the vitamin D compounds lower the bcl-2/bax ratio favouring increased susceptibility of MCF-7 cells to undergo apoptosis.These results suggest that the synthetic vitamin D analogue EB1089 may promote tumour regression by inducing active cell death. PMID

  6. Inhibition of proliferation and induction of apoptosis in soft tissue sarcoma cells by interferon-α and retinoids

    PubMed Central

    Brodowicz, T; Wiltschke, C; Kandioler-Eckersberger, D; Grunt, T W; Rudas, M; Schneider, S M; Hejna, M; Budinsky, A; Zielinski, C C

    1999-01-01

    Uncontrolled proliferation and a defect of apoptosis constitute crucial elements in the development and progression of tumours. Among many other biological response modifiers known to influence these mechanisms, the efficacy of retinoids and interferons in the treatment of various malignant entities is currently matter of discussion. In the present study, we have investigated the effects of 9-cis-retinoic acid (9cRA), 13-cis-retinoic acid (13cRA), all-trans-retinoic acid (tRA) and interferon-α on proliferation and apoptosis of human soft tissue sarcoma (STS) cell lines HTB-82 (rhabdomyosarcoma), HTB-91 (fibrosarcoma), HTB-92 (liposarcoma), HTB-93 (synovial sarcoma) and HTB-94 (chondrosarcoma) in relation to p53 genotype as well as p53 expression. HTB-91, HTB-92 and HTB-94 STS cells exhibited mutant p53, whereas wild-type p53 was found in HTB-93 STS cells, and a normal p53 status in HTB-82 STS cells, carrying a silent point mutation only. Interferon-α, irrespective of p53 status, inhibited the proliferation of all five cell lines dose- and time-dependently. Similarly, 9cRA, 13cRA and tRA decreased the proliferation of HTB-82 and HTB-93 STS cells, whereas the proliferation of p53-mutated HTB-91, HTB-92 and HTB-94 STS cells remained unchanged. Furthermore, only 9cRA and tRA were capable of inducing apoptosis in HTB-82 and HTB-93 STS cells, whereas HTB-91, HTB-92 and HTB-94 STS cells did not undergo apoptosis under the influence of 9cRA or tRA. Retinoic acid receptor (RAR)-α and RAR-β mRNA were not detectable by Northern blot analysis in the five STS cell lines, whereas mRNA for the universal retinoic acid receptor, RAR-γ, was expressed in all STS cell lines indicating that retinoid resistance was not associated with a lack of RAR expression. Apoptosis was not induced by interferon-α or 13cRA in any of the five STS cell lines tested. Our results indicate that within the panel of tested STS cell lines, inhibition of proliferation and induction of apoptosis result

  7. Demethoxycurcumin Retards Cell Growth and Induces Apoptosis in Human Brain Malignant Glioma GBM 8401 Cells

    PubMed Central

    Huang, Tzuu-Yuan; Hsu, Che-Wen; Chang, Weng-Cheng; Wang, Miin-Yau; Wu, June-Fu; Hsu, Yi-Chiang

    2012-01-01

    Demethoxycurcumin (DMC; a curcumin-related demethoxy compound) has been recently shown to display antioxidant and antitumor activities. It has also produced a potent chemopreventive action against cancer. In the present study, the antiproliferation (using the MTT assay, DMC was found to have cytotoxic activities against GBM 8401 cell with IC50 values at 22.71 μM) and induced apoptosis effects of DMC have been investigated in human brain malignant glioma GBM 8401 cells. We have studied the mitochondrial membrane potential (MMP), DNA fragmentation, caspase activation, and NF-κB transcriptional factor activity. By these approaches, our results indicated that DMC has produced an inhibition of cell proliferation as well as the activation of apoptosis in GBM 8401 cells. Both effects were observed to increase in proportion with the dosage of DMC treatment, and the apoptosis was induced by DMC in human brain malignant glioma GBM 8401 cells via mitochondria- and caspase-dependent pathways. PMID:22454662

  8. Docosahexaenoic Acid Induces Apoptosis in Primary Chronic Lymphocytic Leukemia Cells

    PubMed Central

    Gyan, Emmanuel; Tournilhac, Olivier; Halty, Christelle; Veyrat-Masson, Richard; Akil, Saïda; Berger, Marc; Hérault, Olivier; Callanan, Mary; Bay, Jacques-Olivier

    2015-01-01

    Chronic lymphocytic leukemia is an indolent disorder with an increased infectious risk remaining one of the main causes of death. Development of therapies with higher safety profile is thus a challenging issue. Docosahexaenoic acid (DHA, 22:6) is an omega-3 fatty acid, a natural compound of normal cells, and has been shown to display antitumor potency in cancer. We evaluated the potential in vitro effect of DHA in primary CLL cells. DHA induces high level of in vitro apoptosis compared to oleic acid in a dose-dependent and time-dependent manner. Estimation of IC50 was only of 4.813 µM, which appears lower than those reported in solid cancers. DHA is highly active on CLL cells in vitro. This observation provides a rationale for further studies aiming to understand its mechanisms of action and its potent in vivo activity. PMID:26734128

  9. Effects of LG268 on Cell Proliferation and Apoptosis of NB4 Cells

    PubMed Central

    Xu, Ting; Zhong, Liang; Gan, Liu-Gen; Xiao, Chun-Lan; Shan, Zhi-Ling; Yang, Rong; Song, Hao; Li, Liu; Liu, Bei-Zhong

    2016-01-01

    Aims: To investigate the effect of LG100268 (LG268) on cell proliferation and apoptosis in NB4 cells. Methods: NB4 cells were treated with LG268 for 24 h or 48 h. The effect of LG268 on cell proliferation was assessed by the CCK-8 assay and colony-forming assay. Apoptosis and cell cycle were evaluated by flow cytometry. The protein expression levels of Survivin, PARP, c-Myc, cyclin D1, ERK, p-ERK, p38 MAPK, and p- p38 MAPK were detected by western blot. Results: We found that LG268 inhibited the proliferation of NB4 cells in a dose-dependent manner. Flow cytometry analysis showed that LG268 accelerated apoptosis in NB4 cells in a time- dependent manner and that LG268 treatment led to cell cycle arrest at G0/G1 phase. Moreover, LG268 significantly decreased the protein levels of Survivin, c-Myc, and cyclinD1. Cleaved PARP was observed in the LG268 treatment group but not in the control group. In addition, LG268 increased the phosphorylation level of p38 MAPK and decreased the phosphorylation level of ERK. Conclusions: LG268 inhibited cell proliferation and promoted cell apoptosis in NB4 cells. PMID:27429588

  10. Smac mimetic sensitizes renal cell carcinoma cells to interferon-α-induced apoptosis.

    PubMed

    Reiter, Michael; Eckhardt, Ines; Haferkamp, Axel; Fulda, Simone

    2016-05-28

    The prognosis of metastatic or relapsed renal cell carcinoma (RCC) is still very poor, highlighting the need for new treatment strategies. Here, we identify a cooperative antitumor activity of interferon-α (IFNα) together with the Smac mimetic BV6 that antagonizes antiapoptotic IAP proteins. BV6 and IFNα act together to reduce cell viability and to induce apoptosis in various RCC cell lines. Molecular studies revealed that BV6/IFNα co-treatment triggers apoptosis independently of autocrine/paracrine Tumor Necrosis Factor (TNF)α signaling, since the TNFα-blocking antibody Enbrel fails to rescue cell death. Importantly, knockdown of Receptor-Interacting Protein (RIP)1 significantly decreases BV6/IFNα-mediated apoptosis, whereas the RIP1 kinase inhibitor necrostatin-1 (Nec-1) provides no protection. This demonstrates that RIP1 protein is critically required for BV6/IFNα-induced apoptosis, while RIP1 kinase activity is dispensable, pointing to a scaffold function of RIP1. Consistently, BV6 and IFNα cooperate to trigger the interaction of RIP1, Fas-Associated Death Domain protein (FADD) and caspase-8 to form a cytosolic cell death complex that drives caspase activation. Addition of the broad-range caspase inhibitor N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (zVAD.fmk) significantly protects RCC cells against BV6/IFNα-induced apoptosis, demonstrating that caspase activity is required for apoptosis. In conclusion, the combination approach of IFNα and BV6 represents a promising strategy for cooperative induction of apoptosis in RCC cells, which warrants further investigation. PMID:26912071

  11. Nucleotide excision repair deficiency increases levels of acrolein-derived cyclic DNA adduct and sensitizes cells to apoptosis induced by docosahexaenoic acid and acrolein.

    PubMed

    Pan, Jishen; Sinclair, Elizabeth; Xuan, Zhuoli; Dyba, Marcin; Fu, Ying; Sen, Supti; Berry, Deborah; Creswell, Karen; Hu, Jiaxi; Roy, Rabindra; Chung, Fung-Lung

    2016-07-01

    The acrolein derived cyclic 1,N(2)-propanodeoxyguanosine adduct (Acr-dG), formed primarily from ω-3 polyunsaturated fatty acids such as docosahexaenoic acid (DHA) under oxidative conditions, while proven to be mutagenic, is potentially involved in DHA-induced apoptosis. The latter may contribute to the chemopreventive effects of DHA. Previous studies have shown that the levels of Acr-dG are correlated with apoptosis induction in HT29 cells treated with DHA. Because Acr-dG is shown to be repaired by the nucleotide excision repair (NER) pathway, to further investigate the role of Acr-dG in apoptosis, in this study, NER-deficient XPA and its isogenic NER-proficient XAN1 cells were treated with DHA. The Acr-dG levels and apoptosis were sharply increased in XPA cells, but not in XAN1 cells when treated with 125μM of DHA. Because DHA can induce formation of various DNA damage, to specifically investigate the role of Acr-dG in apoptosis induction, we treated XPA knockdown HCT116+ch3 cells with acrolein. The levels of both Acr-dG and apoptosis induction increased significantly in the XPA knockdown cells. These results clearly demonstrate that NER deficiency induces higher levels of Acr-dG in cells treated with DHA or acrolein and sensitizes cells to undergo apoptosis in a correlative manner. Collectively, these results support that Acr-dG, a ubiquitously formed mutagenic oxidative DNA adduct, plays a role in DHA-induced apoptosis and suggest that it could serve as a biomarker for the cancer preventive effects of DHA. PMID:27036235

  12. Vanadate induces apoptosis in epidermal JB6 P+ cells via hydrogen peroxide-mediated reactions.

    PubMed

    Ye, J; Ding, M; Leonard, S S; Robinson, V A; Millecchia, L; Zhang, X; Castranova, V; Vallyathan, V; Shi, X

    1999-12-01

    Apoptosis is a physiological mechanism for the control of DNA integrity in mammalian cells. Vanadium induces both DNA damage and apoptosis. It is suggested that vanadium-induced apoptosis serves to eliminate DNA-damaged cells. This study is designed to clarify a role of reactive oxygen species in the mechanism of apoptosis induced by vanadium. We established apoptosis model with murine epidermal JB6 P+ cells in the response to vanadium stimulation. Apoptosis was detected by a cell death ELISA assay and morphological analysis. The result shows that apoptosis induced by vanadate is dose-dependent, reaching its saturation level at a concentration of 100 microM vanadate. Vanadyl (IV) can also induce apoptosis albeit with lesser potency. A role of reactive oxygen species was analyzed by multiple reagents including specific scavengers of different reactive oxygen species. The result shows that vanadate-induced apoptosis is enhanced by NADPH, superoxide dismutase and sodium formate, but was inhibited by catalase and deferoxamine. Cells exposed to vanadium consume more molecular oxygen and at the same time, produce more H2O2 as measured by the change in fluorescence of scopoletin in the presence of horseradish peroxidase. This change in oxygen consumption and H2O2 production is enhanced by NADPH. Taken together, these results show that vanadate induces apoptosis in epidermal cells and H2O2 induced by vanadate plays a major role in this process. PMID:10705990

  13. Transfusion strategies in patients undergoing stem-cell transplantation.

    PubMed

    Radia, Rohini; Pamphilon, Derwood

    2011-04-01

    Hemopoietic stem-cell transplant patients may require intensive blood component support. Complications of transfusions include transmission of viral and bacterial infections, transfusion-associated graft-versus-host disease and transfusion-related acute lung injury. Alloimmunization to red cell antigens may cause difficulties in selecting compatible blood, while alloimmunization to HLA expressed on platelets may cause subsequent platelet transfusion refractoriness. It is essential to define robust transfusion policies and procedures and these should be regularly audited. This article reviews blood component transfusion in the setting of hemopoietic stem-cell transplant and specifically discusses the management of ABO-mismatched transplants, the prevention of cytomegalovirus transmission, the prevention of transfusion-associated graft-versus-host disease and the use of granulocyte transfusions. PMID:21495930

  14. Influence of cytochrome c on apoptosis induced by Anagrapha (Syngrapha) falcifera multiple nuclear polyhedrosis virus (AfMNPV) in insect Spodoptera litura cells.

    PubMed

    Liu, Lijun; Peng, Jianxin; Liu, Kaiyu; Yang, Hong; Li, Yi; Hong, Huazhu

    2007-09-01

    We investigated the influence of cytochrome c on apoptosis induced by Anagrapha (Syngrapha) falcifera multiple nuclear polyhedrosis virus (AfMNPV). Microscopic observation revealed that infection of SL-1 cells with AfMNPV resulted in apoptosis, displaying apoptotic bodies in fluorescent-stained nuclei of AfMNPV-infected SL-1cells. Western blot analysis demonstrated that AfMNPV-induced apoptosis in insect SL-1 cells was significantly inhibited by cyclosporin A which blocked a translocation of cytochrome c from the mitochondria to the cytosol. As determined by using AC-DEVD-AFC as substrate, the activity of caspase-3 in AfMNPV-induced cells was detected as early as 4h post infection, gradually increased with time extension, and reached a highest level after 16h of infection. However, activity of caspase-3 in apoptotic cells decreased in the presence of cyclosporin A (30microM), indicating that activation of caspase-3 in SfaMNPV-induced cells was dependent on the release of cytochrome c from the mitochondria. In addition, cyclosporin A could markedly inhibit mitochondrial transmembrane potential (DeltaPsim) disruption in undergoing apoptotic cells. These data indicate that cytochrome c plays a key role in AfMNPV-induced apoptosis in S. litura cells and may be required for caspase activation during the induction of apoptosis. PMID:17478109

  15. Upregulation of erythropoietin receptor in UT-7/EPO cells inhibits simulated microgravity-induced cell apoptosis

    NASA Astrophysics Data System (ADS)

    Zou, Li-xue; Cui, Shao-yan; Zhong, Jian; Yi, Zong-chun; Sun, Yan; Fan, Yu-bo; Zhuang, Feng-yuan

    2011-07-01

    Hematopoietic progenitor cell proliferation can be altered in either spaceflight or under simulated microgravity experiments on the ground, however, the underlying mechanism remains unknown. Our previous study showed that exposure of the human erythropoietin (EPO)-dependent leukemia cell line UT-7/EPO to conditions of simulated microgravity significantly inhibited the cellular proliferation rate and induced cell apoptosis. We postulated that the downregulation of the erythropoietin receptor (EPOR) expression in UT-7/EPO cells under simulated microgravity may be a possible reason for microgravity triggered apoptosis. In this paper, a human EPOR gene was transferred into UT-7/EPO cells and the resulting expression of EPOR on the surface of UT-7/EPO cells increased approximately 61% ( p < 0.05) as selected by the antibiotic G418. It was also shown through cytometry assays and morphological observations that microgravity-induced apoptosis markedly decreased in these UT-7/EPO-EPOR cells. Thus, we concluded that upregulation of EPOR in UT-7/EPO cells could inhibit the simulated microgravity-induced cell apoptosis in this EPO dependent cell line.

  16. Induction of apoptosis and cell-cycle arrest in human colon cancer cells by meclizine.

    PubMed

    Lin, Jiunn-Chang; Ho, Yuan-Soon; Lee, Jie-Jen; Liu, Chien-Liang; Yang, Tsen-Long; Wu, Chih-Hsiung

    2007-06-01

    Meclizine (MEC), a histamine H1 antagonist, is used for the treatment of motion sickness and vertigo. In this study, we demonstrate that MEC dose-dependently induced apoptosis in human colon cancer cell lines (COLO 205 and HT 29 cells). Results of a DNA ladder assay revealed that DNA ladders appeared with MEC treatment in COLO 205 cells at dosage of >50 microM. In addition, the total cell number decreased dose-dependently after treatment with MEC in COLO 205 and HT 29 cells. Using flow cytometry, the percentage of COLO 205 cells arrested at G0/G1 phase increased dose-dependently. Analysis of changes in cell-cycle arrest-associated proteins with Western blotting showed that p53 and p21 were upregulated after treatment with MEC. The kinase activities of cyclin-dependent kinase 2 (CDK2) and CDK4 were suppressed in MEC-treated cells. As for apoptosis, MEC may induce upregulation of p53 and downregulation of Bcl-2, thus causing the release of cytochrome C from mitochondria and the translocation of apoptosis-inducing factor (AIF) to the nucleus. This resulted in the activation of caspase 3, 8, and 9. Our results provide the molecular basis of MEC-induced apoptosis and cell-cycle arrest in human colon cancer cells. PMID:17222494

  17. Effect of dicycloplatin, a novel platinum chemotherapeutical drug, on inhibiting cell growth and inducing cell apoptosis.

    PubMed

    Li, Guang-quan; Chen, Xing-gui; Wu, Xing-ping; Xie, Jing-dun; Liang, Yong-ju; Zhao, Xiao-qin; Chen, Wei-qiang; Fu, Li-wu

    2012-01-01

    Dicycloplatin, a new supramolecular platinum-based antitumor drug, has been approved by the State Food and Administration (SFDA) of China. In this study, we investigated the anticancer activity of dicycloplatin in cancer cells and signaling pathways involved in dicycloplatin-induced apoptosis. Dicycloplatin inhibited the proliferation of cancer cells and increased the percentage of apoptosis in a concentration-dependent manner. Besides, some apoptosis related events were observed after treatment with dicycloplatin, including increase of reactive oxygen species (ROS), collapse of mitochondrial membrane potential (Δψm), release of cytochrome c from the mitochondria to the cytosol, upregulation of p53, which were accompanied by activation of caspase-9, caspase-3, caspase-8, and poly (ADP-ribose) polymerase cleavage in a concentration-dependent manner. The role of apoptosis in dicycloplatin-mediated cell death was further confirmed by the concomitant treatment with caspase-8 or caspase-9 inhibitors, which inhibited apoptosis and PARP cleavage. Intracellular glutathione (GSH) was also found to inhibit the cytotoxic effect of dicycloplatin. In conclusion, these findings suggest that dicycloplatin induces apoptosis through ROS stress-mediated death receptor pathway and mitochondrial pathway which is similar to carboplatin. PMID:23152837

  18. Tangeretin induces cell cycle arrest and apoptosis through upregulation of PTEN expression in glioma cells.

    PubMed

    Ma, Li-Li; Wang, Da-Wei; Yu, Xu-Dong; Zhou, Yan-Ling

    2016-07-01

    Tangeretin (TANG), present in peel of citrus fruits, has been shown to various medicinal properties such as chemopreventive and neuroprotective. However, the chemopreventive effect of TANG on glioblastoma cells has not been examined. The present study was designed to explore the anticancer potential of TANG in glioblastoma cells and to investigate the related mechanism. Human glioblastoma U-87MG and LN-18 cells were treated with 45μM concentration of TANG and cell growth was measured by MTT assay. The cell cycle distribution and cell death were measured by flow cytometry. The expression of cell cycle and apoptosis related genes were analyzed by quantitative RT-PCR and western blot. The cells treated with TANG were significantly increased cell growth suppression and cell death effects than vehicle treated cells. Further, TANG treatment increases G2/M arrest and apoptosis by modulating PTEN and cell-cycle regulated genes such as cyclin-D and cdc-2 mRNA and protein expressions. Moreover, the ability of TANG to decrease cell growth and to induce cell death was compromised when PTEN was knockdown by siRNA. Taken together, the chemopreventive effect of TANG is associated with regulation of cell-cycle and apoptosis in glioblastoma, thereby attenuating glioblastoma cell growth. Hence, the present findings suggest that TANG may be a therapeutic agent for glioblastoma treatment. PMID:27261630

  19. Denbinobin induces apoptosis by apoptosis-inducing factor releasing and DNA damage in human colorectal cancer HCT-116 cells.

    PubMed

    Chen, Tzu-Hsuan; Pan, Shiow-Lin; Guh, Jih-Hwa; Chen, Chien-Chih; Huang, Yao-Ting; Pai, Hui-Chen; Teng, Che-Ming

    2008-11-01

    Denbinobin is a phenanthraquinone derivative present in the stems of Ephemerantha lonchophylla. We showed that denbinobin induces apoptosis in human colorectal cancer cells (HCT-116) in a concentration-dependent manner. The addition of a pan-caspase inhibitor (zVAD-fmk) did not suppress the denbinobin-induced apoptotic effect, and denbinobin-induced apoptosis was not accompanied by processing of procaspase-3, -6, -7, -9, and -8. However, denbinobin triggered the translocation of the apoptosis-inducing factor (AIF) from the mitochondria into the nucleus. Small interfering RNA targeting of AIF effectively protected HCT-116 cells against denbinobin-induced apoptosis. Denbinobin treatment also caused DNA damage, activation of the p53 tumor suppressor gene, and upregulation of numerous downstream effectors (p21WAF1/CIP1, Bax, PUMA, and NOXA). A HCT-116 xenograft model demonstrated the in vivo efficacy and low toxicity of denbinobin. Taken together, our findings suggest that denbinobin induces apoptosis of human colorectal cancer HCT-116 cells via DNA damage and an AIF-mediated pathway. These results indicate that denbinobin has potential as a novel anticancer agent. PMID:18607570

  20. Baculovirus p35 increases pancreatic {beta}-cell resistance to apoptosis

    SciTech Connect

    Hollander, Kenneth; Bar-Chen, Michal; Efrat, Shimon . E-mail: sefrat@post.tau.ac.il

    2005-07-01

    {beta}-cells die by apoptosis in type 1 diabetes as a result of autoimmune attack mediated by cytokines, and in type 2 diabetes by various perpetrators including human islet amyloid polypeptide (hIAPP). The cascade of apoptotic events induced by cytokines and hIAPP is mediated through caspases and reactive oxygen species. The baculovirus p35 protein is a potent anti-apoptotic agent shown to be effective in a variety of species and able to inhibit a number of apoptotic pathways. Here, we aimed at determining the protective potential of p35 in {beta}-cells exposed to cytokines and hIAPP, as well as the effects of p35 on {beta}-cell function. The p35 gene was introduced into {beta}TC-tet cells, a differentiated murine {beta}-cell line capable of undergoing inducible growth-arrest. Both proliferating and growth-arrested cells expressing p35 manifested increased resistance to cytokines and hIAPP, compared with control cells, as judged by cell viability, DNA fragmentation, and caspase-3 activity assays. p35 was significantly more protective in growth-arrested, compared with proliferating, cells. No significant differences were observed in proliferation and insulin content between cells expressing p35 and control cells. In contrast, p35 manifested a perturbing effect on glucose-induced insulin secretion. These findings suggest that p35 could be incorporated as part of a multi-pronged approach of immunoprotective strategies to provide protection from recurring autoimmunity for transplanted {beta}-cells, as well as in preventive gene therapy in type 1 diabetes. p35 may also be protective from {beta}-cell damage caused by hIAPP in type 2 diabetes.

  1. Protein Isoaspartate Methyltransferase Prevents Apoptosis Induced by Oxidative Stress in Endothelial Cells: Role of Bcl-Xl Deamidation and Methylation

    PubMed Central

    Cimmino, Amelia; Capasso, Rosanna; Muller, Fabbri; Sambri, Irene; Masella, Lucia; Raimo, Marianna; De Bonis, Maria Luigia; D'Angelo, Stefania; Zappia, Vincenzo; Galletti, Patrizia; Ingrosso, Diego

    2008-01-01

    Background Natural proteins undergo in vivo spontaneous post-biosynthetic deamidation of specific asparagine residues with isoaspartyl formation. Deamidated-isomerized molecules are both structurally and functionally altered. The enzyme isoaspartyl protein carboxyl-O-methyltransferase (PCMT; EC 2.1.1.77) has peculiar substrate specificity towards these deamidated proteins. It catalyzes methyl esterification of the free α-carboxyl group at the isoaspartyl site, thus initiating the repair of these abnormal proteins through the conversion of the isopeptide bond into a normal α-peptide bond. Deamidation occurs slowly during cellular and molecular aging, being accelerated by physical-chemical stresses brought to the living cells. Previous evidence supports a role of protein deamidation in the acquisition of susceptibility to apoptosis. Aim of this work was to shed a light on the role of PCMT in apoptosis clarifying the relevant mechanism(s). Methodology/Principal Findings Endothelial cells transiently transfected with various constructs of PCMT, i.e. overexpressing wild type PCMT or negative dominants, were used to investigate the role of protein methylation during apoptosis induced by oxidative stress (H2O2; 0.1–0.5 mM range). Results show that A) Cells overexpressing “wild type” human PCMT were resistant to apoptosis, whereas overexpression of antisense PCMT induces high sensitivity to apoptosis even at low H2O2 concentrations. B) PCMT protective effect is specifically due to its methyltransferase activity rather than to any other non-enzymatic interactions. In fact negative dominants, overexpressing PCMT mutants devoid of catalytic activity do not prevent apoptosis. C) Cells transfected with antisense PCMT, or overexpressing a PCMT mutant, accumulate isoaspartyl-containing damaged proteins upon H2O2 treatment. Proteomics allowed the identification of proteins, which are both PCMT substrates and apoptosis effectors, whose deamidation occurs under oxidative

  2. Transient axonal glycoprotein-1 induces apoptosis-related gene expression without triggering apoptosis in U251 glioma cells

    PubMed Central

    Chang, Haigang; Song, Shanshan; Chen, Zhongcan; Wang, Yaxiao; Yang, Lujun; Du, Mouxuan; Ke, Yiquan; Xu, Ruxiang; Jin, Baozhe; Jiang, Xiaodan

    2014-01-01

    Previous studies show that transient axonal glycoprotein-1, a ligand of amyloid precursor protein, increases the secretion of amyloid precursor protein intracellular domain and is involved in apoptosis in Alzheimer's disease. In this study, we examined the effects of transient axonal glycoprotein-1 on U251 glioma cells. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay showed that transient axonal glycoprotein-1 did not inhibit the proliferation of U251 cells, but promoted cell viability. The terminal deoxynucleotidyl transferase dUTP nick end labeling assay showed that transient axonal glycoprotein-1 did not induce U251 cell apoptosis. Real-time PCR revealed that transient axonal glycoprotein-1 substantially upregulated levels of amyloid precursor protein intracellular C-terminal domain, and p53 and epidermal growth factor receptor mRNA expression. Thus, transient axonal glycoprotein-1 increased apoptosis-related gene expression in U251 cells without inducing apoptosis. Instead, transient axonal glycoprotein-1 promoted the proliferation of these glioma cells. PMID:25206849

  3. Endonucleases induced TRAIL-insensitive apoptosis in ovarian carcinoma cells

    SciTech Connect

    Geel, Tessa M.; Meiss, Gregor; Gun, Bernardina T. van der; Kroesen, Bart Jan; Leij, Lou F. de; Zaremba, Mindaugas; Silanskas, Arunas; Kokkinidis, Michael; Ruiters, Marcel H.; McLaughlin, Pamela M.; Rots, Marianne G.

    2009-09-10

    TRAIL induced apoptosis of tumor cells is currently entering phase II clinical settings, despite the fact that not all tumor types are sensitive to TRAIL. TRAIL resistance in ovarian carcinomas can be caused by a blockade upstream of the caspase 3 signaling cascade. We explored the ability of restriction endonucleases to directly digest DNA in vivo, thereby circumventing the caspase cascade. For this purpose, we delivered enzymatically active endonucleases via the cationic amphiphilic lipid SAINT-18{sup Registered-Sign }:DOPE to both TRAIL-sensitive and insensitive ovarian carcinoma cells (OVCAR and SKOV-3, respectively). Functional nuclear localization after delivery of various endonucleases (BfiI, PvuII and NucA) was indicated by confocal microscopy and genomic cleavage analysis. For PvuII, analysis of mitochondrial damage demonstrated extensive apoptosis both in SKOV-3 and OVCAR. This study clearly demonstrates that cellular delivery of restriction endonucleases holds promise to serve as a novel therapeutic tool for the treatment of resistant ovarian carcinomas.

  4. A B-Cell Superantigen Induces the Apoptosis of Murine and Human Malignant B Cells.

    PubMed

    Lorenzo, Daniela; Duarte, Alejandra; Mundiñano, Juliana; Berguer, Paula; Nepomnaschy, Irene; Piazzon, Isabel

    2016-01-01

    B-cell superantigens (Sags) bind to conserved sites of the VH or VL regions of immunoglobulin molecules outside their complementarity-determining regions causing the apoptosis of normal cognate B cells. No attempts to investigate whether B-cell Sags are able to induce the apoptosis of cognate malignant B cells were reported. In the present study we show that protein L (PpL), secreted by Finegoldia magna, a B-cell Sag which interacts with κ+ bearing cells, induces the apoptosis of murine and human κ+ lymphoma B cells both in vitro and in vivo. Apoptosis was not altered by caspase-8 inhibitor. No alterations in the levels of Bid, Fas and Fas-L were found suggesting that PpL does not activate the extrinsic pathway of apoptosis. The involvement of the intrinsic pathway was clearly indicated by: i) alterations in mitochondrial membrane potential (ΔΨm) both in murine and human lymphoma cells exposed to PpL; ii) decreased levels of apoptosis in the presence of caspase-9 inhibitor; iii) significant increases of Bim and Bax protein levels and downregulation of Bcl-2; iv) the translocation from the cytoplasm to the mitochondria of Bax and Bim pro-apoptotic proteins and its inhibition by caspase-9 inhibitor but not by caspase-8 inhibitor and v) the translocation of Bcl-2 protein from the mitochondria to the cytosol and its inhibition by caspase-9 inhibitor but not by caspase-8 inhibitor. The possibility of a therapeutic use of Sags in lymphoma/leukemia B cell malignancies is discussed. PMID:27603942

  5. Real-Time In Vivo Imaging of Retinal Cell Apoptosis after Laser Exposure

    PubMed Central

    Schmitz-Valckenberg, Steffen; Guo, Li; Maass, Annelie; Cheung, William; Vugler, Anthony; Moss, Stephen E.; Munro, Peter M. G.; Fitzke, Frederick W.; Cordeiro, M. Francesca

    2008-01-01

    Purpose To investigate whether the detection of apoptosing retinal cells (DARC) could detect cells undergoing apoptosis in a laser model of retinal damage. Methods Laser lesions were placed, with the use of a frequency-doubled Nd:YAG laser, on the retina in 34 eyes of anesthetized Dark Agouti rats. Lesion size and laser-induced retinal elevation were analyzed using in vivo reflectance imaging. Development of retinal cell apoptosis was assessed using intravitreal fluorescence-labeled annexin 5 in vivo with DARC technology from baseline until 90 minutes after laser application. Histologic analysis of retinal flat mounts and cross-sections was performed. Results The lateral and anteroposterior depth extension of the zone of laser damage was significantly larger for higher exposure settings. A strong diffuse signal, concentrated at the outer retina, was seen with DARC for low exposures (<300 ms and <300 mW). In comparison, higher exposures (>300 ms and >300 mW) resulted in detectable hyperfluorescent spots, mainly at the level of the inner retinal layers. Dose-dependent effects on spot density and positive correlation of spot density between lesion size (P < 0.0001) and retinal elevation (P < 0.0001) were demonstrated. Histology confirmed the presence of apoptosing retinal cells in the inner nuclear and the ganglion cell layers. Conclusions This is the first time that DARC has been used to determine apoptotic effects in the inner nuclear layer. The ability to monitor changes spatially and temporally in vivo promises to be a major advance in the real-time assessment of retinal diseases and treatment effects. PMID:18281610

  6. Propofol Decreases Endoplasmic Reticulum Stress–Mediated Apoptosis in Retinal Pigment Epithelial Cells

    PubMed Central

    Xu, Yue; Zhang, Ting; Zhang, Shaochong

    2016-01-01

    Age-related macular degeneration (AMD) is the major cause of loss of sight globally. There is currently no effective treatment available. Retinal pigment epithelial (RPE) cells are an important part of the outer blood-retina barrier and their death is a determinant of AMD. Propofol, a common clinically used intravenous anesthetic agent, has been shown to act as an efficacious neuroprotective agent with antioxidative and anti-inflammatory properties in vivo and in vitro. However, little is known about its effects on RPE cells. The purpose of our research was to investigate whether propofol could protect RPE cells from apoptosis through endoplasmic reticulum (ER) stress–dependent pathways. To this end, prior to stimulation with thapsigargin (TG), ARPE-19 cells were pretreated with varying concentrations of propofol. A protective effect of propofol in TG-treated ARPE-9 was apparent, TUNEL and flow cytometric assays showed decreased apoptosis. We further demonstrated that propofol pretreatment attenuated or inhibited the effects caused by TG, such as upregulation of Bax, BiP, C/EBP homologous protein (CHOP), active caspase 12, and cleaved caspase 3, and downregulation of Bcl2. It also decreased the TG-induced levels of ER stress–related molecules such as p-PERK, p-eIF2α, and ATF4. Furthermore, it downregulated the expression of nuclear factor κB (NF-κB). This study elucidated novel propofol-induced cellular mechanisms for antiapoptotic activities in RPE cells undergoing ER stress and demonstrated the potential value of using propofol in the treatment of AMD. PMID:27311010

  7. IARS2 silencing induces non-small cell lung cancer cells proliferation inhibition, cell cycle arrest and promotes cell apoptosis.

    PubMed

    Yin, J; Liu, W; Li, R; Liu, J; Zhang, Y; Tang, W; Wang, K

    2016-01-01

    The purpose of this study was to investigate the potential role of Ileucyl-tRNA synthetase (IARS2) silencing in non-small cell lung cancer (NSCLC). The silencing of IARS2 in H1299 cells and A549 cells were performed by lentivirus encoding shRNAs. The efficiency of IARS2 silencing was detected by quantitative real time PCR and western blot. The effects of IARS2 silencing on cell growth, cell apoptosis, cell cycle and cell colony formation ability were assessed by cells counting, MTT assay, flow cytometer analysis and soft agar colony formation assay, respectively. Compared with negative control group, IARS2 was significantly knockdown by transfection with lentivirus encoding shRNA of IARS2. The IARS2 silencing significantly inhibited the cells proliferation and cells colony formation ability, induced cell cycle arrest at G1/S phase and promoted cell apoptosis. IARS2 silencing induced NSCLC cells growth inhibition, cell cycle arrest and promoted cell apoptosis. These results suggest that IARS2 may be a novel target for the treatment of NSCLC. PMID:26639235

  8. Astaxanthin Inhibits Proliferation and Induces Apoptosis and Cell Cycle Arrest of Mice H22 Hepatoma Cells

    PubMed Central

    Shao, Yiye; Ni, Yanbo; Yang, Jing; Lin, Xutao; Li, Jun; Zhang, Lixia

    2016-01-01

    Background It is widely recognized that astaxanthin (ASX), a member of the carotenoid family, has strong biological activities including antioxidant, anti-inflammation, and immune-modulation activities. Previous studies have confirmed that ASX can effectively inhibit hepatoma cells in vitro. Material/Methods MTT was used to assay proliferation of mice H22 cells, and flow cytometry was used to determine apoptosis and cell cycle arrest of H22 cells in vitro and in vivo. Moreover, anti-tumor activity of ASX was observed in mice. Results ASX inhibited the proliferation of H22 cells, promoted cell necrosis, and induced cell cycle arrest in G2 phase in vitro and in vivo. Conclusions This study indicated that ASX can inhibit proliferation and induce apoptosis and cell cycle arrest in mice H22 hepatoma cells in vitro and in vivo. PMID:27333866

  9. Astaxanthin Inhibits Proliferation and Induces Apoptosis and Cell Cycle Arrest of Mice H22 Hepatoma Cells.

    PubMed

    Shao, Yiye; Ni, Yanbo; Yang, Jing; Lin, Xutao; Li, Jun; Zhang, Lixia

    2016-01-01

    BACKGROUND It is widely recognized that astaxanthin (ASX), a member of the carotenoid family, has strong biological activities including antioxidant, anti-inflammation, and immune-modulation activities. Previous studies have confirmed that ASX can effectively inhibit hepatoma cells in vitro. MATERIAL AND METHODS MTT was used to assay proliferation of mice H22 cells, and flow cytometry was used to determine apoptosis and cell cycle arrest of H22 cells in vitro and in vivo. Moreover, anti-tumor activity of ASX was observed in mice. RESULTS ASX inhibited the proliferation of H22 cells, promoted cell necrosis, and induced cell cycle arrest in G2 phase in vitro and in vivo. CONCLUSIONS This study indicated that ASX can inhibit proliferation and induce apoptosis and cell cycle arrest in mice H22 hepatoma cells in vitro and in vivo. PMID:27333866

  10. Gravisensing, apoptosis, and drug recovery in Taxus cell suspensions

    NASA Technical Reports Server (NTRS)

    Durzan, D. J.

    1999-01-01

    Haploid and diploid cell suspensions of Taxus spp. were examined for their adaptive plasticity in response to simulated microgravity, unit gravity, and hypergravity. Cell suspensions produced the taxane, paclitaxel, (TAXOL (R)), which is useful for the treatment of various cancers. Amyloplasts contributed to taxane ring biosynthesis and to drug release at the cell wall. Drug-producing cells reacted as gravisensing osmotic tensiometers. In stressed cells, amyloplasts docked and fused in clusters to sites on the plasmalemma before taxane discharge into the culture medium. In simulated microgravity and compared to all other treatments, taxane production was reduced nearly 100-fold. The percent paclitaxel of total taxanes remained 3-to 6-fold greater, and biomass doubled. When p53-independent programmed cell death was induced, taxanes were released into the culture medium as free molecules (soluble and insoluble) or bound to membranes, nuclear fragments, xylan residues, and other particulate materials. Unit gravity and especially hypergravity promoted xylogenesis and significant drug overproduction. A model relating families of >touch = (TCH), taxane early response (TER), nuclear cycling, and apoptosis-regulating genes to gravisensing, cell wall modifications, and to taxane recovery accounted for most but not all of the observations.

  11. Cell responses to FGFR3 signalling: growth, differentiation and apoptosis

    SciTech Connect

    L'Hote, Corine G.M. . E-mail: Corine.LHote@cancer.org.uk; Knowles, Margaret A.

    2005-04-01

    FGFR3 is a receptor tyrosine kinase (RTK) of the FGF receptor family, known to have a negative regulatory effect on long bone growth. Fgfr3 knockout mice display longer bones and, accordingly, most germline-activating mutations in man are associated with dwarfism. Somatically, some of the same activating mutations are associated with the human cancers multiple myeloma, cervical carcinoma and carcinoma of the bladder. How signalling through FGFR3 can lead to either chondrocyte apoptosis or cancer cell proliferation is not fully understood. Although FGFR3 can be expressed as two main splice isoforms (IIIb or IIIc), there is no apparent link with specific cell responses, which may rather be associated with the cell type or its differentiation status. Depending on cell type, differential activation of STAT proteins has been observed. STAT1 phosphorylation seems to be involved in inhibition of chondrocyte proliferation while activation of the ERK pathway inhibits chondrocyte differentiation and B-cell proliferation (as in multiple myeloma). The role of FGFR3 in epithelial cancers (bladder and cervix) is not known. Some of the cell specificity may arise via modulation of signalling by crosstalk with other signalling pathways. Recently, inhibition of the ERK pathway in achondroplastic mice has provided hope for an approach to the treatment of dwarfism. Further understanding of the ability of FGFR3 to trigger different responses depending on cell type and cellular context may lead to treatments for both skeletal dysplasias and cancer.

  12. Rapid onset of nucleolar disintegration preceding cell cycle arrest in roscovitine-induced apoptosis of human MCF-7 breast cancer cells.

    PubMed

    Wojciechowski, Jacek; Horky, Marcel; Gueorguieva, Marieta; Wesierska-Gadek, Józefa

    2003-09-10

    The aim of our study was to explore the antiproliferative and pro-apoptotic action of roscovitine (ROSC) on human breast cancer MCF-7 cells. We examined the effect of ROSC on cell proliferation, cell cycle progression, nucleolar morphology, posttranslational modifications of histones as well as on induction of apoptosis. The effects of ROSC on the argyrophilic nucleolar organizer regions (AgNORs) and nucleolar RNA of MCF-7 cells were marked: ROSC treatment changed the pattern of AgNORs in a time-dependent manner. The disintegration of nucleoli manifested by increasing number of nucleolar fragments already began at 6 hr posttreatment. This was accompanied by a redistribution of the nucleolin from the nucleolus beginning after 6 hr and preceded a decrease of histone acetylation and phosphorylation. Inhibition of DNA synthesis and accumulation of G(2)/M-arrested cells starting 6 hr posttreatment coincided with a strong increase of the p53 level and with an appearance of a few cells committed to undergo apoptosis. However, all these changes preceded the main wave of apoptosis, which occurred after 24 hr ROSC treatment as assessed by determination of the frequency of Annexin binding, activation of caspases as well as of DNA fragmentation. Onset of PARP-1 cleavage detected by immunoblotting and by immunohistochemistry 6 hr or 9 hr posttreatment, respectively, preceded for a few hours the DNA fragmentation detected in situ by TUNEL assay. Reconstitution of MCF-7 cells with caspase-3 did not change the kinetics of ROSC-induced apoptosis. Our results show that disintegration of nucleoli is an early marker of ROSC-induced changes. Cell cycle arrest precedes the main wave of apoptosis. PMID:12845642

  13. Src kinase inhibitors induce apoptosis and mediate cell cycle arrest in lymphoma cells.

    PubMed

    Nowak, Daniel; Boehrer, Simone; Hochmuth, Simone; Trepohl, Bettina; Hofmann, Wencke; Hoelzer, Dieter; Hofmann, Wolf-Karsten; Mitrou, Paris S; Ruthardt, Martin; Chow, Kai Uwe

    2007-10-01

    Src kinases are involved in multiple cellular contexts such as proliferation, adhesion, tumor invasiveness, angiogenesis, cell cycle control and apoptosis. We here demonstrate that three newly developed dual selective Src/Abl kinase inhibitors (SrcK-I) (AZM559756, AZD0530 and AZD0424) are able to induce apoptosis and cell cycle arrest in BCR-ABL, c-KIT and platelet-derived growth factor-negative lymphoma cell lines. Treatment of DOHH-2, WSU-NHL, Raji, Karpas-299, HUT78 and Jurkat cells with SrcK-I revealed that the tested substances were effective on these parameters in the cell lines DOHH-2 and WSU-NHL, whereas the other tested cell lines remained unaffected. Phosphorylation of Lyn and in particular Lck were affected most heavily by treatment with the SrcK-I. Extrinsic as well as intrinsic apoptosis pathways were activated and elicited unique expressional patterns of apoptosis-relevant proteins such as downregulation of survivin, Bcl-XL and c-FLIP. Protein levels of c-abl were downregulated and Akt phosphorylation was decreased by treatment with SrcK-I. Basal expression levels of c-Myc were notably lower in sensitive cell lines as compared with nonsensitive cell lines, possibly providing an explanation for sensitivity versus resistance against these novel substances. This study provides the first basis for establishing novel SrcK-I as weapons in the arsenal against lymphoma cells. PMID:17704648

  14. Trauma patients’ elevated Tumor Necrosis Related Apoptosis Inducing Ligand (TRAIL) contributes to increased T cell apoptosis

    PubMed Central

    Bandyopadhyay, Gautam; Bankey, Paul E.; Miller-Graziano, Carol L.

    2012-01-01

    Immunosuppression resulting from excessive post-trauma apoptosis of hyperactivated Tcells is controversial. TRAIL mediated Tcell apoptosis decreases highly activated Tcells’ responses. Caspase-10, a particular TRAIL target, was increased in trauma patients’ Tcells with concomitantly elevated plasma TRAIL levels. These patients’ Tcells developed anergy, implicating increased TRAIL-mediated Tcell apoptosis in post-trauma Tcell anergy. Control Tcells cultured with patients’ sera containing high TRAIL levels increased their Caspase-10 activity and apoptosis. Stimulated primary Tcells are TRAIL apoptosis resistant. Increased plasma Thrombospondin-1 and Tcell expression of CD47, a Thrombospondin-1 receptor, preceded patients’ Tcell anergy. CD47 triggering of Tcells increased their sensitivity to TRAIL-induced apoptosis. Augmentation of Tcell TRAIL-induced apoptosis was secondary to CD47 triggered activation of the Src homology-containing phosphatase-1(SHP-1) and was partially blocked by a SHP-1 inhibitor. We suggest that combined post-trauma CD47 triggering, SHP-1 mediated NFκB suppression, and elevated TRAIL levels increase patients’ CD47 expressing Tcell apoptosis, thus contributing to subsequent Tcell anergy. PMID:22926077

  15. Loss of α(E)-catenin promotes Fas mediated apoptosis in tubular epithelial cells

    PubMed Central

    Wang, Xinhui; Parrish, Alan R.

    2015-01-01

    The aging kidney undergoes structural and functional alterations which make it more susceptible to drug-induced acute kidney injury (AKI). Previous studies in our lab have shown that the expression of α(E)-catenin is decreased in aged kidney and loss of α(E)-catenin potentiates AKI-induced apoptosis, but not necrosis, in renal tubular epithelial cells (NRK-52E cells). However, the specific apoptotic pathway underlying the increased AKI-induced cell death is not yet understood. In this study, cells were challenged with nephrotoxicant cisplatin to induce AKI. A ~5.5-fold increase in Fas expression in C2 (stable α(E)-catenin knockdown) relative to NT3 (non-targeted control) cells was seen. Increased caspase-8 and -9 activation was induced by cisplatin in C2 as compared to NT3 cells. In addition, decreased Bcl-2 expression and increased BID cleavage and cytochrome C release were detected in C2 cells after cisplatin challenge. Treating the cells with cisplatin, in combination with a Bcl-2 inhibitor, decreased the viability of NT3 cells to the same level as C2 cells after cisplatin. Furthermore, caspase-3/-7 activation is blocked by Fas, caspase-8, caspase-9 and pan-caspase inhibitors. These inhibitors also completely abolished the difference in viability between NT3 and C2 cells in response to cisplatin. These results demonstrate a Fas-mediated apoptotic signaling pathway that is enhanced by the age-dependent loss of α(E)-catenin in renal tubule epithelial cells. PMID:25894537

  16. miR-26b Promotes Granulosa Cell Apoptosis by Targeting ATM during Follicular Atresia in Porcine Ovary

    PubMed Central

    Lin, Fei; Li, Ran; Pan, Zeng xiang; Zhou, Bo; Yu, De bing; Wang, Xu guang; Ma, Xue shan; Han, Jing; Shen, Ming; Liu, Hong lin

    2012-01-01

    More than 99% of ovarian follicles undergo atresia in mammals, but the mechanism of follicular atresia remains to be elucidated. In this study, we explored microRNA (miRNA) regulation of follicular atresia in porcine ovary. A miRNA expression profile was constructed for healthy, early atretic, and progressively atretic follicles, and the differentially expressed miRNAs were selected and analyzed. We found that miR-26b, which was upregulated during follicular atresia, increased the number of DNA breaks and promoted granulosa cell apoptosis by targeting the ataxia telangiectasia mutated gene directly in vitro. PMID:22737216

  17. Impact of apoptosis on the on-line measured dielectric properties of CHO cells.

    PubMed

    Zalai, Dénes; Tobak, Teodóra; Putics, Ákos

    2015-12-01

    Apoptosis is a common type of cell death in biopharmaceutical cell culture processes which causes decrease in viable cell density and product yield. The progression of apoptosis has been reported to influence the dielectric properties of mammalian cells; however, the on-line detection of these effects has been rarely described. This study provides a comprehensive analysis of the on-line detectability of dielectric changes upon apoptosis induction in an industrial fed-batch process of CHO cells expressing a recombinant monoclonal antibody. Using capacitance signals, measured at 25 frequencies, the impact of apoptosis on the dielectric spectra was investigated in eight bioreactor cultivations in which various process conditions were combined with two different apoptosis induction strategies (camptothecin treatment and glucose starvation). To differentiate the apoptosis-related information from the cell concentration-associated variance in the multivariate capacitance datasets, principal component analysis (PCA) was used. A second principal component, explaining an explicit proportion (>20%) of the variance, was identified to be related to dielectric changes induced by apoptosis. Furthermore, the analysis of caspase-3 and -7 activation and DNA fragmentation showed that the detected dielectric change occurred in the early phase of apoptosis. The presented results verify that apoptosis has a considerable impact on the dielectric features of CHO cells and it can be monitored on-line with the introduced tool-set combining capacitance measurement with multivariate data analysis. PMID:26440966

  18. Efficacy of an AC sinusoidal electric field for apoptosis induction in lung carcinoma cells (A549)

    NASA Astrophysics Data System (ADS)

    Park, Hyoun-Hyang; Lee, Seung S.; Hoon Lee, Dae

    2012-08-01

    An AC sinusoidal electric field was applied to lung carcinoma cells for the induction of apoptosis. The occurrence of apoptosis was determined by analysis of Annexin V/PI and DNA fragmentation. Additional evidence of apoptosis was confirmed by caspase-3 cleavage and disruption of mitochondrial membrane potential. These results demonstrated that the expression of apoptosis can be controlled by varying the magnitude and the duration of the field, and that the application of an AC electric field can stimulate the apoptosis via mitochondria-mediated pathway.

  19. Targeting hedgehog signalling by arsenic trioxide reduces cell growth and induces apoptosis in rhabdomyosarcoma.

    PubMed

    Boehme, Karen A; Zaborski, Julian J; Riester, Rosa; Schweiss, Sabrina K; Hopp, Ulrike; Traub, Frank; Kluba, Torsten; Handgretinger, Rupert; Schleicher, Sabine B

    2016-02-01

    Rhabdomyosarcomas (RMS) are soft tissue tumours treated with a combination of surgery and chemotherapy. However, mortality rates remain high in case of recurrences and metastatic disease due to drug resistance and failure to undergo apoptosis. Therefore, innovative approaches targeting specific signalling pathways are urgently needed. We analysed the impact of different hedgehog (Hh) pathway inhibitors on growth and survival of six RMS cell lines using MTS assay, colony formation assay, 3D spheroid cultures, flow cytometry and western blotting. Especially the glioma-associated oncogene family (GLI) inhibitor arsenic trioxide (ATO) effectively reduced viability as well as clonal growth and induced cell death in RMS cell lines of embryonal, alveolar and sclerosing, spindle cell subtype, whereas normal skeletal muscle cells were hardly compromised by ATO. Combination of ATO with itraconazole potentiated the reduction of colony formation and spheroid size. These results show that ATO is a promising substance for treatment of relapsed and refractory RMS by directly targeting GLI transcription factors. The combination with itraconazole or other chemotherapeutic drugs has the opportunity to enforce the treatment efficiency of resistant and recurrent RMS. PMID:26676886

  20. Annexin A2 mediates secretion of collagen VI, pulmonary elasticity and apoptosis of bronchial epithelial cells

    PubMed Central

    Dassah, MaryAnn; Almeida, Dena; Hahn, Rebecca; Bonaldo, Paolo; Worgall, Stefan; Hajjar, Katherine A.

    2014-01-01

    ABSTRACT The annexins are an evolutionarily conserved family of phospholipid-binding proteins of largely unknown function. We observed that the AnxA2−/− lung basement membrane specifically lacks collagen VI (COL6), and postulated that ANXA2 directs bronchial epithelial cell secretion of COL6, an unusually large multimeric protein. COL6 serves to anchor cells to basement membranes and, unlike other collagens, undergoes multimerization prior to secretion. Here, we show that AnxA2−/− mice have reduced exercise tolerance with impaired lung tissue elasticity, which was phenocopied in Col6a1−/− mice. In vitro, AnxA2−/− fibroblasts retained COL6 within intracellular vesicles and adhered poorly to their matrix unless ANXA2 expression was restored. In vivo, AnxA2−/− bronchial epithelial cells underwent apoptosis and disadhesion. Immunoprecipitation and immunoelectron microscopy revealed that ANXA2 associates with COL6 and the SNARE proteins SNAP-23 and VAMP2 at secretory vesicle membranes of bronchial epithelial cells, and that absence of ANXA2 leads to retention of COL6 in a late-Golgi, VAMP2-positive compartment. These results define a new role for ANXA2 in the COL6 secretion pathway, and further show that this pathway establishes cell–matrix interactions that underlie normal pulmonary function and epithelial cell survival. PMID:24357721

  1. FLIP switches Fas-mediated glucose signaling in human pancreatic cells from apoptosis to cell replication

    NASA Astrophysics Data System (ADS)

    Maedler, Kathrin; Fontana, Adriano; Ris, Frédéric; Sergeev, Pavel; Toso, Christian; Oberholzer, José; Lehmann, Roger; Bachmann, Felix; Tasinato, Andrea; Spinas, Giatgen A.; Halban, Philippe A.; Donath, Marc Y.

    2002-06-01

    Type 2 diabetes mellitus results from an inadequate adaptation of the functional pancreatic cell mass in the face of insulin resistance. Changes in the concentration of glucose play an essential role in the regulation of cell turnover. In human islets, elevated glucose concentrations impair cell proliferation and induce cell apoptosis via up-regulation of the Fas receptor. Recently, it has been shown that the caspase-8 inhibitor FLIP may divert Fas-mediated death signals into those for cell proliferation in lymphatic cells. We observed expression of FLIP in human pancreatic cells of nondiabetic individuals, which was decreased in tissue sections of type 2 diabetic patients. In vitro exposure of islets from nondiabetic organ donors to high glucose levels decreased FLIP expression and increased the percentage of apoptotic terminal deoxynucleotidyltransferase-mediated UTP end labeling (TUNEL)-positive cells; FLIP was no longer detectable in such TUNEL-positive cells. Up-regulation of FLIP, by incubation with transforming growth factor or by transfection with an expression vector coding for FLIP, protected cells from glucose-induced apoptosis, restored cell proliferation, and improved cell function. The beneficial effects of FLIP overexpression were blocked by an antagonistic anti-Fas antibody, indicating their dependence on Fas receptor activation. The present data provide evidence for expression of FLIP in the human cell and suggest a novel approach to prevent and treat diabetes by switching Fas signaling from apoptosis to proliferation.

  2. SAMHD1 controls cell cycle status, apoptosis and HIV-1 infection in monocytic THP-1 cells.

    PubMed

    Bonifati, Serena; Daly, Michele B; St Gelais, Corine; Kim, Sun Hee; Hollenbaugh, Joseph A; Shepard, Caitlin; Kennedy, Edward M; Kim, Dong-Hyun; Schinazi, Raymond F; Kim, Baek; Wu, Li

    2016-08-01

    SAMHD1 limits HIV-1 infection in non-dividing myeloid cells by decreasing intracellular dNTP pools. HIV-1 restriction by SAMHD1 in these cells likely prevents activation of antiviral immune responses and modulates viral pathogenesis, thus highlighting a critical role of SAMHD1 in HIV-1 physiopathology. Here, we explored the function of SAMHD1 in regulating cell proliferation, cell cycle progression and apoptosis in monocytic THP-1 cells. Using the CRISPR/Cas9 technology, we generated THP-1 cells with stable SAMHD1 knockout. We found that silencing of SAMHD1 in cycling cells stimulates cell proliferation, redistributes cell cycle population in the G1/G0 phase and reduces apoptosis. These alterations correlated with increased dNTP levels and more efficient HIV-1 infection in dividing SAMHD1 knockout cells relative to control. Our results suggest that SAMHD1, through its dNTPase activity, affects cell proliferation, cell cycle distribution and apoptosis, and emphasize a key role of SAMHD1 in the interplay between cell cycle regulation and HIV-1 infection. PMID:27183329

  3. Effect of silencing HOXA5 gene expression using RNA interference on cell cycle and apoptosis in Jurkat cells

    PubMed Central

    HUANG, HUI-PING; LIU, WEN-JUN; GUO, QU-LIAN; BAI, YONG-QI

    2016-01-01

    Acute lymphocytic leukemia (ALL) is a common malignant tumor with a high morbidity rate among children, accounting for approximately 80% of leukemia cases. Although there have been improvements in the treatment of patients frequent relapse lead to a poor prognosis. The aim of the present study was to determine whether HOXA5 may be used as a target for gene therapy in leukemia in order to provide a new treatment. Mononuclear cells were extracted from the bone marrow according to the clinical research aims. After testing for ALL in the acute stage, the relative mRNA and protein expression of HOXA5 was detected in the ALL remission groups (n=25 cases per group) and the control group [n=20 cases, immune thrombocytopenia (ITP)]. Gene silencing by RNA interference (RNAi) was used to investigate the effect of silencing HOXA5 after small interfering RNA (siRNA) transfection to Jurkat cells. The HOXA5-specific siRNA was transfected to Jurkat cells using lipofectamine. The experiment was divided into the experimental group (liposomal transfection of HOXA5 targeting siRNA), the negative control group (liposomal transfection of cells with negative control siRNA) and the control group (plus an equal amount of cells and culture media only). Western blotting and quantitative fluorescent polymerase chain reaction (QF-PCR) were used to detect the relative HOXA5 mRNA expression and protein distribution in each cell group. Cell distribution in the cell cycle and the rate of cells undergoing apoptosis were determined using flow cytometry. The expression of HOXA5 at the mRNA and protein levels in the acute phase of ALL was significantly higher than that in ALL in the remission and control groups. In cells transfected with HOXA5-specific siRNA, the expression of HOXA5 at the mRNA and protein levels decreased significantly (P<0.05). The distribution of cells in the cell cycle was also altered. Specifically, more cells were present in the G0/G1 phase compared to the S phase (P<0.05). In

  4. Hyperthermia Induces Apoptosis of 786-O Cells through Suppressing Ku80 Expression

    PubMed Central

    Qi, Defeng; Hu, Yuan; Li, Jinhui; Peng, Tao; Su, Jialin; He, Yun; Ji, Weidong

    2015-01-01

    Hyperthermia as an anticancer method has been paid increasing attention in recent years. Several studies have shown that hyperthermia can kill tumor cells by inducing apoptosis. However, the underlying molecular mechanisms of hyperthermia-induced apoptosis are largely unknown. To investigate the effects and molecular mechanism of hyperthermia on the apoptosis in renal carcinoma 786-O cells, we firstly examined apoptosis and Ku expression in 786-O cell line treated with heat exposure (42°C for 0-4 h). The results showed that hyperthermia induced apoptosis of 786-O cells, and suppressed significantly Ku80 expression, but not Ku70 expression. Next, we knock-down Ku80 in 786-O cells, generating stable cell line 786-O-shKu80, and detected apoptosis, cell survival and cell cycle distribution. Our data showed higher apoptotic rate and lower surviving fraction in the stable cell line 786-O-shKu80 compared with those in control cells, exposed to the same heat stress (42°C for 0-4 h). Moreover, the results also showed suppression of Ku80 led to G2/M phase arrest in the stable cell line 786-O-shKu80 following heat treatment. Together, these findings indicate that Ku80 may play an important role in hyperthermia-induced apoptosis and heat-sensitivity of renal carcinoma cells through influencing the cell cycle distribution. PMID:25902193

  5. Prolonged insulin treatment sensitizes apoptosis pathways in pancreatic β cells.

    PubMed

    Bucris, E; Beck, A; Boura-Halfon, S; Isaac, R; Vinik, Y; Rosenzweig, T; Sampson, S R; Zick, Y

    2016-09-01

    Insulin resistance results from impaired insulin signaling in target tissues that leads to increased levels of insulin required to control plasma glucose levels. The cycle of hyperglycemia and hyperinsulinemia eventually leads to pancreatic cell deterioration and death by a mechanism that is yet unclear. Insulin induces ROS formation in several cell types. Furthermore, death of pancreatic cells induced by oxidative stress could be potentiated by insulin. Here, we investigated the mechanism underlying this phenomenon. Experiments were done on pancreatic cell lines (Min-6, RINm, INS-1), isolated mouse and human islets, and on cell lines derived from nonpancreatic sources. Insulin (100nM) for 24h selectively increased the production of ROS in pancreatic cells and isolated pancreatic islets, but only slightly affected the expression of antioxidant enzymes. This was accompanied by a time- and dose-dependent decrease in cellular reducing power of pancreatic cells induced by insulin and altered expression of several ER stress response elements including a significant increase in Trb3 and a slight increase in iNos The effect on iNos did not increase NO levels. Insulin also potentiated the decrease in cellular reducing power induced by H2O2 but not cytokines. Insulin decreased the expression of MCL-1, an antiapoptotic protein of the BCL family, and induced a modest yet significant increase in caspase 3/7 activity. In accord with these findings, inhibition of caspase activity eliminated the ability of insulin to increase cell death. We conclude that prolonged elevated levels of insulin may prime apoptosis and cell death-inducing mechanisms as a result of oxidative stress in pancreatic cells. PMID:27411561

  6. Overexpression of X chromosome-linked inhibitor of apoptosis by inhibiting microRNA-24 protects periodontal ligament cells against hydrogen peroxide-induced cell apoptosis.

    PubMed

    Liu, C; Chen, Z; Wang, J; Hu, H

    2016-01-01

    Hydrogen peroxide (H2O2), a common oral clinical drug for the tooth bleaching, induces severe cell apoptosis of periodontal ligament cells (PDLCs). The excessive cell apoptosis of PDLCs impairs periodontal tissue damage and repair. However, the underlying mechanism is incompletely understood. Here, we showed that microRNA-24 (miR-24) played an important role in regulating H2O2-induced cell apoptosis of PDLCs. We found that miR-24 expression was increased in PDLCs in response to H2O2 treatment. Down-regulation of miR-24 obviously rescued H2O2-induced cell apoptosis in PDLCs. By bioinformatic analysis, X chromosome-linked inhibitor of apoptosis (XIAP) was identified as a candidate target gene of miR-24, which was further verified by the dual-luciferase reporter assay. Furthermore, the protein expression level of phosphatase and tensin homolog deleted on chromosome ten was significantly decreased by miR-24 silencing, whereas the phosphorylation of Akt was remarkably increased by miR-24 silencing. In addition, the gene silencing of XIAP significantly reduced Akt activity and blocked the protective effect of the miR-24 inhibitor against H2O2-induced cell apoptosis. Overall, our findings suggest that miR-24 plays an important role in regulating the cell survival of PDLCs through targeting XIAP. PMID:27188727

  7. Cell Survival and Apoptosis Signaling as Therapeutic Target for Cancer: Marine Bioactive Compounds

    PubMed Central

    Kalimuthu, Senthilkumar; Se-Kwon, Kim

    2013-01-01

    Inhibition of apoptosis leads to activation of cell survival factors (e.g., AKT) causes continuous cell proliferation in cancer. Apoptosis, the major form of cellular suicide, is central to various physiological processes and the maintenance of homeostasis in multicellular organisms. A number of discoveries have clarified the molecular mechanism of apoptosis, thus clarifying the link between apoptosis and cell survival factors, which has a therapeutic outcome. Induction of apoptosis and inhibition of cell survival by anticancer agents has been shown to correlate with tumor response. Cellular damage induces growth arrest and tumor suppression by inducing apoptosis, necrosis and senescence; the mechanism of cell death depends on the magnitude of DNA damage following exposure to various anticancer agents. Apoptosis is mainly regulated by cell survival and proliferating signaling molecules. As a new therapeutic strategy, alternative types of cell death might be exploited to control and eradicate cancer cells. This review discusses the signaling of apoptosis and cell survival, as well as the potential contribution of marine bioactive compounds, suggesting that new therapeutic strategies might follow. PMID:23348928

  8. Activation of protease-activated receptor 2 reduces glioblastoma cell apoptosis

    PubMed Central

    2014-01-01

    Background The pathogenesis of glioma is unclear. The disturbance of the apoptosis process plays a critical role in glioma growth. Factors regulating the apoptosis process are to be further understood. This study aims to investigate the role of protease activated receptor-2 (PAR2) in regulation the apoptosis process in glioma cells. Results The results showed that U87 cells and human glioma tissue expressed PAR2. Exposure to tryptase, or the PAR2 active peptide, increased STAT3 phosphorylation in the radiated U87 cells, reduced U87 cell apoptosis, suppressed the expression of p53 in U87 cells. Conclusions Activation of PAR2 can reduce the radiated U87 cell apoptosis via modulating the expression of p53. The results implicate that PAR2 may be a novel therapeutic target in the treatment of glioma. PMID:24670244

  9. Tissue Inhibitor of Metalloproteinase-4 Triggers Apoptosis in Cervical Cancer Cells

    PubMed Central

    Lizarraga, Floria; Ceballos-Cancino, Gisela; Espinosa, Magali; Vazquez-Santillan, Karla; Maldonado, Vilma; Melendez-Zajgla, Jorge

    2015-01-01

    Tissue inhibitor of metalloproteinase-4 (TIMP-4) is a member of extracellular matrix (ECM) metalloproteinases inhibitors that has pleiotropic functions. However, TIMP-4 roles in carcinogenesis are not well understood. Cell viability and flow cytometer assays were employed to evaluate cell death differences between H-Vector and H-TIMP-4 cell lines. Immunobloting and semi-quantitative RT-PCR were used to evaluate the expression of apoptosis regulators. We showed that TIMP-4 has apoptosis-sensitizing effects towards several death stimuli. Consistent with these findings, regulators of apoptosis from Inhibitors of Apoptosis Proteins (IAP), FLICE-like inhibitor proteins (FLIP) and Bcl-2 family members were modulated by TIMP-4. In addition, TIMP-4 knockdown resulted in cell survival increase after serum deprivation, as assessed by clonogenic cell analyses. This report shows that TIMP-4 regulates carcinogenesis through apoptosis activation in cervical cancer cells. Understanding TIMP-4 effects in tumorigenesis may provide clues for future therapies. PMID:26291714

  10. Apoptosis of human pancreatic carcinoma cell-1 cells induced by Yin Chen Hao Decoction

    PubMed Central

    Zhou, Hai-Bo; Chen, Jing-Ming; Shao, Li-Ming; Chen, Zhi-Gang

    2015-01-01

    AIM: To evaluate human pancreatic carcinoma cell line (PANC-1) cells apoptosis and Bcl-2 and Bax expression induced by Yin Chen Hao Decoction (YCHD). METHODS: The cell growth inhibitory rate was determined by MTT assay. Apoptosis of PANC-1 cells before and after treatment with YCHD was determined by TUNEL staining. Expression of the apoptosis-associated genes, Bcl-2 and Bax, was detected by immunohistochemical staining and reverse transcription -PCR. RESULTS: YCHD inhibited the growth of PANC-1 cells. Following treatment with YCHD for 24-96 h, the apoptotic rate of PANC-1 cells increased with time. In addition, the positive rate of Bcl-2 protein expression decreased in a time-dependent manner, whereas the positive rate of Bax protein expression increased in a time-dependent manner. Following treatment of with YCHD for 24-96h, expression of BAX mRNA increased gradually and BCL-2 mRNA reduced gradually with time. CONCLUSION: YCHD induces apoptosis of PANC-1 cells mediated in part via up-regulation of BAX and down-regulation of BCL-2. PMID:26217086

  11. Ultrasonication processed Panax ginseng berry extract induces apoptosis through an intrinsic apoptosis pathway in HepG2 cells.

    PubMed

    Jung, Hyunwoo; Bae, Jinhyung; Ko, Sung Kwon; Sohn, Uy Dong

    2016-06-01

    Ginseng's major active components, ginsenosides, have been known to show anti-cancer, neuroprotective, and anti-inflammatory activities. Ultrasonication processed Panax ginseng berry extract (UGB) contains various ginsenosides. The components are different from Panax ginseng berry extract (GBE). This study was aimed to investigate the cytotoxic mechanism of UGB in HepG2 cells, human hepatocellular carcinoma cell line. HepG2 cells were treated with UGB (0, 10, 20 μg/ml). Cell growth and cellular apoptosis were evaluated by MTT assay and Annexin V/Pi staining, respectively. Intracellular Reactive oxygen species (ROS) levels were also determined by 2', 7'-dichlorofluorescin diacetate (DCFDA) staining. The expressions of Bax, Bcl-2 and caspase-3, the apoptotic markers, were evaluated by Western Blot. UGB dose-dependently inhibited cell growth and induced apoptotic cell death. Intracellular ROS levels were increased. UGB increased the expression of the cleaved form of caspase-3. Furthermore, UGB induced apoptosis of HepG2 cells through Bax activation and Bcl-2 inhibition. In conclusion, UGB induced apoptosis through an intrinsic pathway in HepG2 cells suggesting that UGB might play a role as a novel substance for anti-cancer effect. PMID:27233905

  12. Induction of apoptosis by Citrus paradisi essential oil in human leukemic (HL-60) cells.

    PubMed

    Hata, Tomona; Sakaguchi, Ikuyo; Mori, Masahiro; Ikeda, Norikazu; Kato, Yoshiko; Minamino, Miki; Watabe, Kazuhito

    2003-01-01

    Limonene is a primary component of citrus essential oils (EOs) and has been reported to induce apoptosis on tumor cells. Little is known about induction of apoptosis by citrus EOs. In this study, we examined induction of apoptosis by Citrus aurantium var. dulcis (sweet orange) EO, Citrus paradisi (grapefruit) EO and Citrus limon (lemon) EO. These EOs induced apoptosis in HL-60 cells and the apoptosis activities were related to the limonene content of the EOs. Moreover, sweet orange EO and grapefruit EO may contain components besides limonene that have apoptotic activity. To identify the components with apoptotic activity, grapefruit EO was fractionated using silica gel columns, and the components were analyzed by GC-MS. The n-hexane fraction contained limonene, and the dichloromethane fraction (DF) contained aldehyde compounds and nootkatone. Decanal, octanal and citral in the DF showed strong apoptotic activity, suggesting that the aldehyde compounds induced apoptosis strongly in HL-60 cells. PMID:14758720

  13. Niclosamide inhibits the proliferation of human osteosarcoma cell lines by inducing apoptosis and cell cycle arrest.

    PubMed

    Li, Zonghuan; Yu, Yifeng; Sun, Shaoxing; Qi, Baiwen; Wang, Weiyang; Yu, Aixi

    2015-04-01

    Niclosamide, used as an antihelminthic, has demonstrated some properties of anticancer effects. However, its role in osteosarcoma remains to be determined. The aim of this study was to determine the effect of niclosamide on human osteosarcoma cell lines. The human MG-63 and U2OS osteosarcoma cell lines were treated with different concentrations of niclosamide. The cell inhibitory rate was calculated by CCK-8 assay. Cell cycle was detected by flow cytometry. Cell apoptosis was determined by Hoechst 33324 staining, flow cytometry and fluorescence microscope, respectively. The expression of bcl-2, bax and pro-caspase-3 were measured by western blotting. Niclosamide exerted an inhibitory effect on the two cell lines in a time- and dose-dependent manner. Niclosamide was found to induce the arrest of S and G2/M phase in U2OS cells and G2/M in MG-63 cells. Moreover, niclosamide induced apoptosis in MG-63 and U2OS cells. The bax/bcl-2 ratio increased while the expression of pro‑caspase-3 decreased significantly in the two cell lines. The results indicated that niclosamide inhibits proliferation, and induces apoptosis and cell cycle arrest in human osteosarcoma cell lines. PMID:25634333

  14. Ethyl acetate extracts of Fructus Ligustri Lucide induce cell apoptosis in human neuroglioma cell

    PubMed Central

    Guo, Yun-Bao; Shao, Yi-Meng; Chen, Jing; Xu, Song-Bai; Zhang, Xing-Dong; Liu, Hai-Yan

    2015-01-01

    Objective: Previous studies have shown that Fructus Ligustri Lucide (FLL) can be used to improve the tumor cells sensitivity to chemotherapeutics and promote cell death. However, the mechanism by which FLL mediate this effect is unclear. In the present study, ethyl acetate extracts of FLL induced cell apoptosis in human neuroglioma cell was investigated. Methods: The cell viability was detected by the CCK8 assay. The cell apoptosis was assessed by annexin V-PI double-labeling staining and hoechst 33342 staining. The protein expression of cell cycle regulators and tumor suppressors were analyzed by western blotting. Results: Treatment of human neuroglioma cell with FLL induced cell death in a dose-and time-dependent manner by using CCK8 assay. Consistent with the CCK8 assay, the flow cytometry results showed that the proportion of the early and terminal phase of apoptosis cells had gained after FLL treatment as compared to untreatment group. Moreover, human neuroglioma cells were exposed to the ethyl acetate extracts of FLL for 48 h, which resulted in an accumulation of cells in G2/Mphase. Apoptotic bodies were clearly observed in human neuroglioma cells that had been treated with FLL for 48 h and then stained with Hochest 33342. The expression of Cyclin B1, CDC2 and cdc25C were downregulated upon FLL treatment in human neuroglioma cells. The expression level of Cyclin B1, CDC2 and cdc25C was negatively correlated with the time of treatment by FLL. In contrast, p53, p21 and p16 were obviously upregulated by FLL treatment in a time-dependent manner. Conclusions: These results confirmed that FLL could induce apoptosis in human neuroglioma cells, the underlying molecular mechanisms, at least partially, through activation p21/p53 and suppression CDC2/cdc25C signaling in vitro. PMID:26064281

  15. Peroxiredoxin III protects pancreatic ß cells from apoptosis.

    PubMed

    Wolf, Gabriele; Aumann, Nicole; Michalska, Marta; Bast, Antje; Sonnemann, Jürgen; Beck, James F; Lendeckel, Uwe; Newsholme, Philip; Walther, Reinhard

    2010-11-01

    Type 1 diabetes mellitus is characterized by a progressive autoimmune destruction of insulin-producing β cells. Macrophages and T lymphocytes release cytokines, which induce the synthesis of oxygen and nitrogen radicals in the pancreatic islets. The resulting cellular and mitochondrial damage promotes β cell death. β cells are very sensitive to the autoimmune free radical-dependent attack due to their low content of antioxidant enzymes such as glutathione peroxidase and catalase. A focal point of β cell protection should be the control of the mitochondrial redox status, which will result in the preservation of metabolic stimulus-secretion coupling. For this reason, there is a considerable interest in the mitochondrial peroxiredoxin III (PRX III), a thioredoxin-dependent peroxide reductase, which was shown to be able to protect against both oxidative and nitrosative stress. Using the Tet-On-system, we generated stably transfected rat insulinoma cells over- or under-expressing PRX III in a doxycyclin-dependent manner to analyze the effect of increased or decreased amounts of cellular PRX III, following treatment with several stressors. We provide evidence that PRX III protects pancreatic β cells from cell stress induced by accumulation of hydrogen peroxide, or the induction of inducible nitric oxide synthase or caspase-9 and -3 by pro-inflammatory cytokines or streptozotocin. Basal insulin secretion was markedly decreased in cells expressing lower levels of PRX III. We suggest PRX III may be a suitable target for promoting deceleration or even prevention of stress-associated apoptosis in pancreatic β cells and the manifestation of insulin-dependent diabetes mellitus. PMID:20807727

  16. Calretinin mediates apoptosis in small cell lung cancer cells expressing tetraspanin CD9☆

    PubMed Central

    He, Ping; Kuhara, Hanako; Tachibana, Isao; Jin, Yingji; Takeda, Yoshito; Tetsumoto, Satoshi; Minami, Toshiyuki; Kohmo, Satoshi; Hirata, Haruhiko; Takahashi, Ryo; Inoue, Koji; Nagatomo, Izumi; Kida, Hiroshi; Kijima, Takashi; Naka, Tetsuji; Morii, Eiichi; Kawase, Ichiro; Kumanogoh, Atsushi

    2013-01-01

    A majority of small cell lung cancer (SCLC) cells lack a metastasis suppressor, tetraspanin CD9, and CD9 expression promotes their apoptosis. By a proteomics-based approach, we compared an SCLC cell line with its CD9 transfectant and found that a calcium-binding neuronal protein, calretinin, is upregulated in CD9-positive SCLC cells. Ectopic or anticancer drug-induced CD9 expression upregulated calretinin, whereas CD9 knockdown down-regulated calretinin in SCLC cells. When calretinin was knocked down, CD9-positive SCLC cells revealed increased Akt phosphorylation and decreased apoptosis. These results suggest that CD9 positively regulates the expression of calretinin that mediates proapoptotic effect in SCLC cells. PMID:23772398

  17. α-Mangostin Induces Apoptosis and Cell Cycle Arrest in Oral Squamous Cell Carcinoma Cell

    PubMed Central

    Kwak, Hyun-Ho; Park, Bong-Soo

    2016-01-01

    Mangosteen has long been used as a traditional medicine and is known to have antibacterial, antioxidant, and anticancer effects. Although the effects of α-mangostin, a natural compound extracted from the pericarp of mangosteen, have been investigated in many studies, there is limited data on the effects of the compound in human oral squamous cell carcinoma (OSCC). In this study, α-mangostin was assessed as a potential anticancer agent against human OSCC cells. α-Mangostin inhibited cell proliferation and induced cell death in OSCC cells in a dose- and time-dependent manner with little to no effect on normal human PDLF cells. α-Mangostin treatment clearly showed apoptotic evidences such as nuclear fragmentation and accumulation of annexin V and PI-positive cells on OSCC cells. α-Mangostin treatment also caused the collapse of mitochondrial membrane potential and the translocation of cytochrome c from the mitochondria into the cytosol. The expressions of the mitochondria-related proteins were activated by α-mangostin. Treatment with α-mangostin also induced G1 phase arrest and downregulated cell cycle-related proteins (CDK/cyclin). Hence, α-mangostin specifically induces cell death and inhibits proliferation in OSCC cells via the intrinsic apoptosis pathway and cell cycle arrest at the G1 phase, suggesting that α-mangostin may be an effective agent for the treatment of OSCC. PMID:27478478

  18. Caspase-dependent inhibition of store-operated Ca{sup 2+} entry into apoptosis-committed Jurkat cells

    SciTech Connect

    Onopiuk, Marta; Wierzbicka, Katarzyna; Brutkowski, Wojciech; Szczepanowska, Joanna; Zablocki, Krzysztof

    2010-08-20

    Activation of T-cells triggers store-operated Ca{sup 2+} entry, which begins a signaling cascade leading to induction of appropriate gene expression and eventually lymphocyte proliferation and differentiation. The simultaneous enhancement of Fas ligand gene expression in activated cells allows the immune response to be limited by committing the activated cells to apoptosis. In apoptotic cells the store-operated calcium entry is significantly inhibited. It has been documented that moderate activation of Fas receptor may cause reversible inhibition of store-operated channels by ceramide released from hydrolyzed sphingomyelin. Here we show that activation of Fas receptor in T-cells results in caspase-dependent decrease of cellular STIM1 and Orai1 protein content. This effect may be responsible for the substantial inhibition of Ca{sup 2+} entry into Jurkat cells undergoing apoptosis. In turn, this inhibition might prevent overloading of cells with calcium and protect them against necrosis. -- Research highlights: {yields} Fas activation reduces STIM1 and Orai1 protein content in caspase dependent manner. {yields} Fas activation partially reduces mitochondrial potential in caspase dependent manner. {yields} Fas stimulation inhibits of store-operated Ca{sup 2+} entry in caspase dependent manner. {yields} Inhibition of Ca{sup 2+} entry in apoptotic cells may protect them from secondary necrosis.

  19. Knockdown of DDX46 inhibits proliferation and induces apoptosis in esophageal squamous cell carcinoma cells.

    PubMed

    Li, Bin; Li, Yu-Min; He, Wen-Ting; Chen, Hao; Zhu, Hong-Wen; Liu, Tao; Zhang, Jian-Hua; Song, Tie-Niu; Zhou, Ya-Li

    2016-07-01

    Esophageal squamous cell carcinoma (ESCC) is the most common type of esophageal carcinoma and remains the leading cause of cancer-related death worldwide. DEAD-box RNA helicases play critical roles in cellular metabolism and in many cases have been implicated in cellular proliferation and neoplastic transformation. DDX46 belongs to DEAD-box helicase family, the expression pattern of DDX46 in ESCC tissues and the biologic role in ESCC progression have not been implicated previously. In this study, DDX46 expression in human ESCC and adjacent normal tissues were explored using immunohistochemistry, and ESCC cell lines compared with normal esophageal epithelium cell were quantified using real‑time PCR. Next, lentivirus-mediated RNA interference was applied to silence DDX46 in TE-1 and Eca-109 cells. Cell growth was monitored using high content screening. Cell viability was measured by MTT assay. Cell colony-forming capacity was measured by colony formation assay. Cell cycle progression and apoptosis were determined by flow cytometry. Further, the stress and apoptosis signaling antibody array kit was used to detect the changes of signaling molecules in TE-1 cells after DDX46 knockdown. We found that DDX46 was significantly upregulated in ESCC tissues and cells compared with normal tissues and cells. DDX46 knockdown led to decreased proliferation and increased apoptosis in TE-1 and Eca-109 cells. Moreover, DDX46 silencing resulted in apoptotic induction via decreased phosphorylation of Akt and IκBα, as well as negative regulation of NF-κB signaling. In conclusion, these results demonstrate that DDX46 knockdown inhibited cell growth, and induced apoptosis, suggest that DDX46 is critical for ESCC cells proliferation. In addition, this study provides a foundation for further study into the clinical potential diagnosis and novel therapeutic target for ESCC. PMID:27176873

  20. Quinolinic acid induces cell apoptosis in PC12 cells through HIF-1-dependent RTP801 activation.

    PubMed

    Huang, Xiaojia; Yang, Kaiyong; Zhang, Yi; Wang, Qiang; Li, Yongjin

    2016-04-01

    Neurological disease comprises a series of disorders featuring brain dysfunction and neuronal cell death. Among the factors contributing to neuronal death, excitotoxicity induced by excitatory amino acids, such as glutamate, plays a critical role. However, the mechanisms about how the excitatory amino acids induce neuronal death remain elucidated. In this study, we investigated the role of HIF-1α (hypoxia inducible factor-1α) and RTP801 in cell apoptosis induced by quinolinic acid (QUIN), a glutamatergic agonist, in PC12 cells. We found that QUIN at 5 μM increased the expression of HIF-1α significantly with a peak at 24 h. After the treatment with QUIN (5-20 μM) for 24 h, the cells exhibited decreased viability and cell apoptosis with a concomitant increased expression of apoptosis related proteins. QUIN treatment also induced the generation of intracellular reactive oxygen species and RTP801 up-regulation in a HIF-1α-dependent manner that were inhibited by 2-methoxyestradiol, a HIF-1α inhibitor. Importantly, HIF-1 or RTP801 invalidation by siRNA rescued the cell apoptosis induced by QUIN or cobalt chloride, a chemical inducer of HIF-1. Taken together, these findings support the concept that neurotoxicity induced by QUIN is associated with HIF-1-dependent RTP801 activation and provide insight into the potential of RTP801 inhibitor in treatment of neurological disorders. PMID:26738727

  1. GRP78 is required for cell proliferation and protection from apoptosis in chicken embryo fibroblast cells.

    PubMed

    Jeon, M; Choi, H; Lee, S I; Kim, J S; Park, M; Kim, K; Lee, S; Byun, S J

    2016-05-01

    Chicken serum has been suggested as a supplement to promote chicken cell proliferation and development. However, the molecular mechanisms by which chicken serum stimulates chicken cell proliferation remain unknown. Here, we evaluated the effects of chicken serum supplementation on chicken embryo fibroblast (CEF) and DF-1 cell proliferation. We also sought to elucidate the molecular pathways involved in mediating the effects of chicken serum on fibroblasts and DF-1 cells by overexpression of chicken 78 kDa glucose-regulated protein (chGRP78), which is important for cell growth and the prevention of apoptosis. Our data demonstrated that the addition of 5% chicken serum significantly enhanced fibroblast proliferation. Moreover, knockdown of chGRP78 using siRNA decreased fibroblast proliferation and increased apoptosis. Based on these results, we suggest that the chGRP78-mediated signaling pathway plays a critical role in chicken serum-stimulated fibroblast survival and anti-apoptosis. Therefore, our findings have important implications for the maintenance of chicken fibroblast cells through the inhibition of apoptosis and may lead to the development of new treatments for avian disease. PMID:26944959

  2. Nrdp1-mediated degradation of BRUCE decreases cell viability and induces apoptosis in human 786-O renal cell carcinoma cells

    PubMed Central

    Chen, Shao-Jun; Lin, Jian-Hai; Yao, Xu-Dong; Peng, Bo; Xu, Yun-Fei; Liu, Min; Zheng, Jun-Hua

    2016-01-01

    Neuregulin receptor degradation protein-1 (Nrdp1) is involved in a plethora of cellular processes and plays an essential role in the development and progression of human cancers. However, its role in renal cell carcinoma (RCC) remains unclear. Therefore, the present study aimed to explore the biological significance of Nrdp1 in RCC. Western blot analyses of tissue samples from 24 patients with primary RCC revealed lower Nrdp1 and higher baculovirus inhibitor of apoptosis repeat-containing ubiquitin-conjugating enzyme (BRUCE) protein levels in RCC tissues compared with adjacent normal tissues. In addition, MTT and apoptosis assays demonstrated that Nrdp1 overexpression resulted in decreased cell viability and enhanced apoptosis in RCC 786-O cells; conversely, Nrdp1 knockdown increased 786-O cell viability and inhibited apoptosis. Further analysis showed that BRUCE downregulation partially attenuated the effects of Nrdp1 knockdown on RCC cell viability and apoptosis. Moreover, an inverse association was obtained between BRUCE and Nrdp1 protein levels. These findings suggest that Nrdp1-mediated degradation of BRUCE decreases cell viability and induces apoptosis in RCC cells, highlighting Nrdp1 as a potential target for RCC treatment.

  3. p53 upregulated modulator of apoptosis sensitizes drug-resistant U251 glioblastoma stem cells to temozolomide through enhanced apoptosis

    PubMed Central

    MIAO, WANG; LIU, XIAODONG; WANG, HONGQIN; FAN, YIMIN; LIAN, SHIZHONG; YANG, XIN; WANG, XINXING; GUO, GENG; LI, QICHAO; WANG, SIFEI

    2015-01-01

    Malignant glioma is a highly aggressive brain tumor with a poor prognosis. Chemotherapy has been observed to prolong overall survival rate and temozolomide (TMZ), a promising chemotherapeutic agent for treating glioblastoma (GBM), possesses the most effective clinical activity at present, although drug resistance limits its clinical outcome. Growing evidence supports the concept that initial and recurrent GBM may derive from glioblastoma stem cells, which may be responsible for drug resistance. However, the molecular mechanisms underlying this resistance remain to be elucidated. In the present study, a TMZ-resistant GBM cell line, U251R, was developed and subsequently divided into two subpopulations according to the CD133 immunophenotype. No significant difference was identified in the expression of O6-methylguanine-DNA-methyltransferase (MGMT) between CD133+ U251R cells and CD133− U251R cells, whereas the CD133+ cell population was more resistant to TMZ-induced growth inhibition and cell death. TMZ achieves its cytotoxic effect by inducing DNA lesions and p53 upregulated modulator of apoptosis (PUMA) is an essential mediator of DNA damage-induced apoptosis independently of p53 status. Therefore, whether PUMA effectively enhances growth suppression and induces apoptosis when combined with TMZ was investigated. Consequently, it was found that adenoviruses expressing wild-type-PUMA not only lead to the apoptosis of CD133+ U251R cells alone, but also significantly increase their sensitivity toward TMZ by elevating the Bcl-2-associated X protein/B-cell lymphoma-2 ratio without alterations in MGMT expression. Therefore, PUMA may be a suitable target for intervention to improve the therapeutic efficacy of TMZ. PMID:25625235

  4. DNA damage and mitochondria dysfunction in cell apoptosis induced by nonthermal air plasma

    SciTech Connect

    Kim, G. J.; Lee, J. K.; Kim, W.; Kim, K. T.

    2010-01-11

    Nonthermal plasma is known to induce animal cell death but the mechanism is not yet clear. Here, cellular and biochemical regulation of cell apoptosis is demonstrated for plasma treated cells. Surface type nonthermal air plasma triggered apoptosis of B16F10 mouse melanoma cancer cells causing DNA damage and mitochondria dysfunction. Plasma treatment activated caspase-3, apoptosis executioner. The plasma treated cells also accumulated gamma-H2A.X, marker for DNA double strand breaks, and p53 tumor suppressor gene as a response to DNA damage. Interestingly, cytochrome C was released from mitochondria and its membrane potential was changed significantly.

  5. DNA damage and mitochondria dysfunction in cell apoptosis induced by nonthermal air plasma

    NASA Astrophysics Data System (ADS)

    Kim, G. J.; Kim, W.; Kim, K. T.; Lee, J. K.

    2010-01-01

    Nonthermal plasma is known to induce animal cell death but the mechanism is not yet clear. Here, cellular and biochemical regulation of cell apoptosis is demonstrated for plasma treated cells. Surface type nonthermal air plasma triggered apoptosis of B16F10 mouse melanoma cancer cells causing DNA damage and mitochondria dysfunction. Plasma treatment activated caspase-3, apoptosis executioner. The plasma treated cells also accumulated gamma-H2A.X, marker for DNA double strand breaks, and p53 tumor suppressor gene as a response to DNA damage. Interestingly, cytochrome C was released from mitochondria and its membrane potential was changed significantly.

  6. Depletion of histone N-terminal-acetyltransferase Naa40 induces p53-independent apoptosis in colorectal cancer cells via the mitochondrial pathway.

    PubMed

    Pavlou, Demetria; Kirmizis, Antonis

    2016-03-01

    Protein N-terminal acetylation is an abundant post-translational modification in eukaryotes implicated in various fundamental cellular and biochemical processes. This modification is catalysed by evolutionarily conserved N-terminal acetyltransferases (NATs) whose deregulation has been linked to cancer development and thus, are emerging as useful diagnostic and therapeutic targets. Naa40 is a highly selective NAT that acetylates the amino-termini of histones H4 and H2A and acts as a sensor of cell growth in yeast. In the present study, we examine the role of Naa40 in cancer cell survival. We demonstrate that depletion of Naa40 in HCT116 and HT-29 colorectal cancer cells decreases cell survival by enhancing apoptosis, whereas Naa40 reduction in non-cancerous mouse embryonic fibroblasts has no effect on cell viability. Specifically, Naa40 knockdown in colon cancer cells activates the mitochondrial caspase-9-mediated apoptotic cascade. Consistent with this, we show that caspase-9 activation is required for the induced apoptosis because treatment of cells with an irreversible caspase-9 inhibitor impedes apoptosis when Naa40 is depleted. Furthermore, the effect of Naa40-depletion on cell-death is mediated through a p53-independent mechanism since p53-null HCT116 cells still undergo apoptosis upon reduction of the acetyltransferase. Altogether, these findings reveal an anti-apoptotic role for Naa40 and exhibit its potential as a therapeutic target in colorectal cancers. PMID:26666750

  7. Human Adipose Derived Stem Cells Induced Cell Apoptosis and S Phase Arrest in Bladder Tumor

    PubMed Central

    Yu, Xi; Su, Boxing; Ge, Peng; Wang, Zicheng; Li, Sen; Huang, Bingwei; Gong, Yanqing; Lin, Jian

    2015-01-01

    The aim of this study was to determine the effect of human adipose derived stem cells (ADSCs) on the viability and apoptosis of human bladder cancer cells. EJ and T24 cells were cocultured with ADSCs or cultured with conditioned medium of ADSCs (ADSC-CM), respectively. The cell counting and colony formation assay showed ADSCs inhibited the proliferation of EJ and T24 cells. Cell viability assessment revealed that the secretions of ADSCs, in the form of conditioned medium, were able to decrease cancer cell viability. Wound-healing assay suggested ADSC-CM suppressed migration of T24 and EJ cells. Moreover, the results of the flow cytometry indicated that ADSC-CM was capable of inducing apoptosis of T24 cells and inducing S phase cell cycle arrest. Western blot revealed ADSC-CM increased the expression of cleaved caspase-3 and cleaved PARP, indicating that ADSC-CM induced apoptosis in a caspase-dependent way. PTEN/PI3K/Akt pathway and Bcl-2 family proteins were involved in the mechanism of this reaction. Our study indicated that ADSCs may provide a promising and practicable manner for bladder tumor therapy. PMID:25691904

  8. miRNA143 Induces K562 Cell Apoptosis Through Downregulating BCR-ABL

    PubMed Central

    Liang, Bing; Song, Yanbin; Zheng, Wenling; Ma, Wenli

    2016-01-01

    Background Leukemia seriously threats human health and life. MicroRNA regulates cell growth, proliferation, apoptosis, and cell cycle. Whether microRNA could be treated as a target for leukemia is still unclear and the mechanism by which microRNA143 regulates K562 cells needs further investigation. Material/Methods miRNA143 and its scramble miRNA were synthesized and transfected to K562 cells. MTT assay was used to detect K562 cell proliferation. Flow cytometry and a caspase-3 activity detection kit were used to test K562 cell apoptosis. Western blot analysis was performed to determine breakpoint cluster region-Abelson (BCR-ABL) expression. BCR-ABL overexpression and siRNA were used to change BCR-ABL level, and cell apoptosis was detected again after lipofection transfection. Results miRNA143 transfection inhibited K562 cell growth and induced its apoptosis. miRNA143 transfection decreased BCR-ABL expression. BCR-ABL overexpression suppressed miRNA143-induced K562 cell apoptosis, while its reduction enhanced miRNA143-induced apoptosis. Conclusions miRNA143 induced K562 cell apoptosis through downregulating BCR-ABL. miRNA143 might be a target for a new leukemia therapy. PMID:27492780

  9. The Mitochondria-Mediate Apoptosis of Lepidopteran Cells Induced by Azadirachtin

    PubMed Central

    Huang, Jingfei; Lv, Chaojun; Hu, Meiying; Zhong, Guohua

    2013-01-01

    Mitochondria have been shown to play an important role in apoptosis using mammalian cell lines. However, this seems not to be the case in Drosophila, an insect model organism; thus more in-depth studies of insect cell apoptosis are necessary. In the present study, mitochondrial involvement during azadirachtin- and camptothecin-induced apoptosis in Spodoptera frugiperda Sf9 cells (isolated from Spodoptera frugiperda pupal ovarian tissue) was investigated. The results showed that both azadirachtin and camptothecin could induce apoptosis in Sf9 cells. Reactive oxygen species (ROS) generation, activation of mitochondrial permeability transition pores (MPTPs) and loss of mitochondrial membrane potential (MMP) were observed very early during apoptosis and were followed subsequently by the release of cytochrome-c from the mitochondria. Furthermore, the results also revealed that the opening of MPTPs and the loss of MMP induced by azadirachtin could be significantly inhibited by the permeability transition pore (PTP) inhibitor cyclosporin A (CsA), which was used to identify the key role of mitochondria in the apoptosis of Sf9 cells. However, in camptothecin-treated Sf9 cells, CsA could not suppress the opening of MPTPs and the loss of MMP when apoptosis was induced. The data from caspase-3 and caspase-9 activity assays and detection of apoptosis by morphological observation and flow cytometry also uncovered the different effect of CsA on the two botanical apoptosis inducers. Although different mechanisms of apoptosis induction exist, our study revealed that mitochondria play a crucial role in insect cell line apoptosis. PMID:23516491

  10. Ceramide-Induced Apoptosis in Renal Tubular Cells: A Role of Mitochondria and Sphingosine-1-Phoshate

    PubMed Central

    Ueda, Norishi

    2015-01-01

    Ceramide is synthesized upon stimuli, and induces apoptosis in renal tubular cells (RTCs). Sphingosine-1 phosphate (S1P) functions as a survival factor. Thus, the balance of ceramide/S1P determines ceramide-induced apoptosis. Mitochondria play a key role for ceramide-induced apoptosis by altered mitochondrial outer membrane permeability (MOMP). Ceramide enhances oligomerization of pro-apoptotic Bcl-2 family proteins, ceramide channel, and reduces anti-apoptotic Bcl-2 proteins in the MOM. This process alters MOMP, resulting in generation of reactive oxygen species (ROS), cytochrome C release into the cytosol, caspase activation, and apoptosis. Ceramide regulates apoptosis through mitogen-activated protein kinases (MAPKs)-dependent and -independent pathways. Conversely, MAPKs alter ceramide generation by regulating the enzymes involving ceramide metabolism, affecting ceramide-induced apoptosis. Crosstalk between Bcl-2 family proteins, ROS, and many signaling pathways regulates ceramide-induced apoptosis. Growth factors rescue ceramide-induced apoptosis by regulating the enzymes involving ceramide metabolism, S1P, and signaling pathways including MAPKs. This article reviews evidence supporting a role of ceramide for apoptosis and discusses a role of mitochondria, including MOMP, Bcl-2 family proteins, ROS, and signaling pathways, and crosstalk between these factors in the regulation of ceramide-induced apoptosis of RTCs. A balancing role between ceramide and S1P and the strategy for preventing ceramide-induced apoptosis by growth factors are also discussed. PMID:25751724

  11. Isthmin targets cell-surface GRP78 and triggers apoptosis via induction of mitochondrial dysfunction.

    PubMed

    Chen, M; Zhang, Y; Yu, V C; Chong, Y-S; Yoshioka, T; Ge, R

    2014-05-01

    Isthmin (ISM) is a secreted 60-kDa protein that potently induces endothelial cell (EC) apoptosis. It suppresses tumor growth and angiogenesis in mice when stably overexpressed in cancer cells. Although αvβ5 integrin serves as a low-affinity receptor for ISM, the mechanism by which ISM mediates antiangiogenesis and apoptosis in ECs remain to be fully resolved. In this work, we report the identification of cell-surface glucose-regulated protein 78 kDa (GRP78) as a high-affinity receptor for ISM (Kd=8.6 nM). We demonstrated that ISM-GRP78 interaction triggers apoptosis not only in activated ECs but also in cancer cells expressing high level of cell-surface GRP78. Normal cells and benign tumor cells tend to express low level of cell-surface GRP78 and are resistant to ISM-induced apoptosis. Upon binding to GRP78, ISM is internalized into ECs through clathrin-dependent endocytosis that is essential for its proapoptotic activity. Once inside the cell, ISM co-targets with GRP78 to mitochondria where it interacts with ADP/ATP carriers on the inner membrane and blocks ATP transport from mitochondria to cytosol, thereby causing apoptosis. Hence, ISM is a novel proapoptotic ligand that targets cell-surface GRP78 to trigger apoptosis by inducing mitochondrial dysfunction. The restricted and high-level expression of cell-surface GRP78 on cancer cells and cancer ECs make them uniquely susceptible to ISM-targeted apoptosis. Indeed, systemic delivery of recombinant ISM potently suppressed subcutaneous 4T1 breast carcinoma and B16 melanoma growth in mice by eliciting apoptosis selectively in the cancer cells and cancer ECs. Together, this work reveals a novel ISM-GRP78 apoptosis pathway and demonstrates the potential of ISM as a cancer-specific and dual-targeting anticancer agent. PMID:24464222

  12. Adenoviral modification of mouse brain derived endothelial cells, bEnd3, to induce apoptosis by vascular endothelial growth factor.

    PubMed

    Mitsuuchi, Y; Powell, D R; Gallo, J M

    2006-02-01

    A second generation genetically-engineered cell-based drug delivery system, referred to as apoptotic-induced drug delivery (AIDD), was developed using endothelial cells (ECs) that undergo apoptosis upon binding of vascular endothelial growth factor (VEGF) to a Flk-1:Fas fusion protein (FF). This new AIDD was redesigned using mouse brain derived ECs, bEnd3 cells, and an adenovirus vector in order to enhance and control the expression of FF. The FF was tagged with a HA epitope (FFHA) and designed to be coexpressed with green fluorescence protein (GFP) by the regulation of cytomegalovirus promoters in the adenovirus vector. bEnd3 cells showed favorable coexpression of FFHA and GFP consistent with the multiplicity of infection of the adenovirus. Immunofluorescence analysis demonstrated that FFHA was localized at the plasma membrane, whereas GFP was predominantly located in the cytoplasm of ECs. Cell death was induced by VEGF, but not by platelet derived growth factor or fibroblast growth factor in a dose-dependent manner (range 2-20 ng/ml), and revealed caspase-dependent apoptotic profiles. The FFHA expressing bEnd3 cells underwent apoptosis when cocultured with a glioma cell (SF188V+) line able to overexpress VEGF. The combined data indicated that the FFHA adenovirus system can induce apoptotic signaling in ECs in response to VEGF, and thus, is an instrumental modification to the development of AIDD. PMID:16247462

  13. The DREAM complex mediates GIST cell quiescence and is a novel therapeutic target to enhance imatinib-induced apoptosis.

    PubMed

    Boichuk, Sergei; Parry, Joshua A; Makielski, Kathleen R; Litovchick, Larisa; Baron, Julianne L; Zewe, James P; Wozniak, Agnieszka; Mehalek, Keith R; Korzeniewski, Nina; Seneviratne, Danushka S; Schöffski, Patrick; Debiec-Rychter, Maria; DeCaprio, James A; Duensing, Anette

    2013-08-15

    Gastrointestinal stromal tumors (GIST) can be successfully treated with imatinib mesylate (Gleevec); however, complete remissions are rare and patients frequently achieve disease stabilization in the presence of residual tumor masses. The clinical observation that discontinuation of treatment can lead to tumor progression suggests that residual tumor cells are, in fact, quiescent and, therefore, able to re-enter the cell-division cycle. In line with this notion, we have previously shown that imatinib induces GIST cell quiescence in vitro through the APC(CDH1)-SKP2-p27(Kip1) signaling axis. Here, we provide evidence that imatinib induces GIST cell quiescence in vivo and that this process also involves the DREAM complex, a multisubunit complex that has recently been identified as an additional key regulator of quiescence. Importantly, inhibition of DREAM complex formation by depletion of the DREAM regulatory kinase DYRK1A or its target LIN52 was found to enhance imatinib-induced cell death. Our results show that imatinib induces apoptosis in a fraction of GIST cells while, at the same time, a subset of cells undergoes quiescence involving the DREAM complex. Inhibition of this process enhances imatinib-induced apoptosis, which opens the opportunity for future therapeutic interventions to target the DREAM complex for more efficient imatinib responses. PMID:23786773

  14. Apoptosis and inhibition of proliferation of cancer cells induced by cordycepin

    PubMed Central

    TIAN, XUEWEN; LI, YUJIAN; SHEN, YINYU; LI, QIAOQIAO; WANG, QINGLU; FENG, LIANSHI

    2015-01-01

    Cordycepin, a 3-deoxyadenosine, is the predominant functional component of the fungus Cordyceps militaris, a traditional Chinese medicine. Previous studies investigating the inhibition of cancer cells by cordycepin identified that it not only promotes cell apoptosis, but also controls cell proliferation. Furthermore, studies have elucidated the molecular mechanisms of inhibiting cell proliferation by cordycepin binding the A3 adenosine receptor, activating G protein, inhibiting cAMP formation, decreasing glycogen synthase kinase-3β/β-catenin activation and suppressing cyclin D1 and c-myc expression. The most significant signaling pathway in which cell apoptosis is induced by cordycepin is the caspase pathway. Cordycepin induces cell apoptosis via binding the DR3 receptor and consequently activating caspase-8/-3. Taken together, these studies demonstrate that cordycepin may be used as a natural medicine, as it can not only control tumor cell proliferation, but also induce cancer cell apoptosis. PMID:26622539

  15. Isoalantolactone Inhibits UM-SCC-10A Cell Growth via Cell Cycle Arrest and Apoptosis Induction

    PubMed Central

    Wu, Minjun; Zhang, Hua; Hu, Jiehua; Weng, Zhiyong; Li, Chenyuan; Li, Hong; Zhao, Yan; Mei, Xifan; Ren, Fu; Li, Lihua

    2013-01-01

    Isoalantolactone is a sesquiterpene lactone compound isolated from the roots of Inula helenium L. Previous studies have demonstrated that isoalantolactone possesses antifungal, anti-bacterial, anti-helminthic and anti-proliferative properties in a variety of cells, but there are no studies concerning its effects on head and neck squamous cell carcinoma (HNSCC). In the present study, an MTT assay demonstrated that isoalantolactone has anti-proliferative activity against the HNSCC cell line (UM-SCC-10A). Immunostaining identified that this compound induced UM-SCC-10A cell apoptosis but not necrosis. To explain the molecular mechanisms underlying its effects, flow cytometry and western blot analysis showed that the apoptosis was associated with cell cycle arrest during the G1 phase, up-regulation of p53 and p21, and down-regulation of cyclin D. Furthermore, our results revealed that induction of apoptosis through a mitochondrial pathway led to up-regulation of pro-apoptotic protein expression (Bax), down-regulation of anti-apoptotic protein expression (Bcl-2), mitochondrial release of cytochrome c (Cyto c), reduction of mitochondrial membrane potential (MMP) and activation of caspase-3 (Casp-3). Involvement of the caspase apoptosis pathway was confirmed using caspase inhibitor Z-VAD-FMK pretreatment. Together, our findings suggest that isoalantolactone induced caspase-dependent apoptosis via a mitochondrial pathway and was associated with cell cycle arrest in the G1 phase in UM-SCC-10A cells. Therefore, isoalantolactone may become a potential drug for treating HNSCC. PMID:24098753

  16. Par-4/NF-κB Mediates the Apoptosis of Islet β Cells Induced by Glucolipotoxicity.

    PubMed

    QiNan, Wu; XiaGuang, Gan; XiaoTian, Lei; WuQuan, Deng; Ling, Zhang; Bing, Chen

    2016-01-01

    Apoptosis of islet β cells is a primary pathogenic feature of type 2 diabetes, and ER stress and mitochondrial dysfunction play important roles in this process. Previous research has shown that prostate apoptosis response-4 (Par-4)/NF-κB induces cancer cell apoptosis through endoplasmic reticulum (ER) stress and mitochondrial dysfunction. However, the mechanism by which Par-4/NF-κB induces islet β cell apoptosis remains unknown. We used a high glucose/palmitate intervention to mimic type 2 diabetes in vitro. We demonstrated that the high glucose/palmitate intervention induced the expression and secretion of Par-4. It also causes increased expression and activation of NF-κB, which induced NIT-1 cell apoptosis and dysfunction. Overexpression of Par-4 potentiates these effects, whereas downregulation of Par-4 attenuates them. Inhibition of NF-κB inhibited the Par-4-induced apoptosis. Furthermore, these effects occurred through the ER stress cell membrane and mitochondrial pathway of apoptosis. Our findings reveal a novel role for Par-4/NF-κB in islet β cell apoptosis and type 2 diabetes. PMID:27340675

  17. Par-4/NF-κB Mediates the Apoptosis of Islet β Cells Induced by Glucolipotoxicity

    PubMed Central

    QiNan, Wu; XiaGuang, Gan; XiaoTian, Lei; WuQuan, Deng; Ling, Zhang; Bing, Chen

    2016-01-01

    Apoptosis of islet β cells is a primary pathogenic feature of type 2 diabetes, and ER stress and mitochondrial dysfunction play important roles in this process. Previous research has shown that prostate apoptosis response-4 (Par-4)/NF-κB induces cancer cell apoptosis through endoplasmic reticulum (ER) stress and mitochondrial dysfunction. However, the mechanism by which Par-4/NF-κB induces islet β cell apoptosis remains unknown. We used a high glucose/palmitate intervention to mimic type 2 diabetes in vitro. We demonstrated that the high glucose/palmitate intervention induced the expression and secretion of Par-4. It also causes increased expression and activation of NF-κB, which induced NIT-1 cell apoptosis and dysfunction. Overexpression of Par-4 potentiates these effects, whereas downregulation of Par-4 attenuates them. Inhibition of NF-κB inhibited the Par-4-induced apoptosis. Furthermore, these effects occurred through the ER stress cell membrane and mitochondrial pathway of apoptosis. Our findings reveal a novel role for Par-4/NF-κB in islet β cell apoptosis and type 2 diabetes. PMID:27340675

  18. Suppression of PAX6 promotes cell proliferation and inhibits apoptosis in human retinoblastoma cells.

    PubMed

    Meng, Bo; Wang, Yisong; Li, Bin

    2014-08-01

    The aim of this study was to investigate the role of the transcription factor, PAX6, in the development of retinoblastoma. The expression of endogenous PAX6 was knocked down using PAX6-specific lentivirus in two human retinoblastoma cell lines, SO-Rb50 and Y79. Cell proliferation functional assays and apoptotic assays were performed on the cells in which PAX6 was knocked down. The results revealed that PAX6 knockdown efficiency was significant (P<0.01, n=3) in the SO-Rb50 and Y79 cells. The inhibition of PAX6 reduced tumor cell apoptosis (P<0.05, n=3), but induced cell cycle S phase arrest (SO-Rb50; P<0.05, n=3) and G2/M phase arrest (Y79; P<0.05, n=3). Western blot analysis indicated that the inhibition of PAX6 increased the levels of the anti-apoptotic proteins, Bcl-2, proliferating cell nuclear antigen (PCNA) and CDK1, but reduced the levels of the pro-apoptotic proteins, BAX and p21. In conclusion, our data demonstrate that the suppression of PAX6 increases proliferation and decreases apoptosis in human retinoblastoma cells by regulating several cell cycle and apoptosis biomarkers. PMID:24939714

  19. Suppression of PAX6 promotes cell proliferation and inhibits apoptosis in human retinoblastoma cells

    PubMed Central

    MENG, BO; WANG, YISONG; LI, BIN

    2014-01-01

    The aim of this study was to investigate the role of the transcription factor, PAX6, in the development of retinoblastoma. The expression of endogenous PAX6 was knocked down using PAX6-specific lentivirus in two human retinoblastoma cell lines, SO-Rb50 and Y79. Cell proliferation functional assays and apoptotic assays were performed on the cells in which PAX6 was knocked down. The results revealed that PAX6 knockdown efficiency was significant (P<0.01, n=3) in the SO-Rb50 and Y79 cells. The inhibition of PAX6 reduced tumor cell apoptosis (P<0.05, n=3), but induced cell cycle S phase arrest (SO-Rb50; P<0.05, n=3) and G2/M phase arrest (Y79; P<0.05, n=3). Western blot analysis indicated that the inhibition of PAX6 increased the levels of the anti-apoptotic proteins, Bcl-2, proliferating cell nuclear antigen (PCNA) and CDK1, but reduced the levels of the pro-apoptotic proteins, BAX and p21. In conclusion, our data demonstrate that the suppression of PAX6 increases proliferation and decreases apoptosis in human retinoblastoma cells by regulating several cell cycle and apoptosis biomarkers. PMID:24939714

  20. Distinct protease pathways control cell shape and apoptosis in v-src-transformed quail neuroretina cells

    SciTech Connect

    Neel, Benjamin D.; Gillet, Germain . E-mail: g.gillet@ibcp.fr

    2005-11-15

    Intracellular proteases play key roles in cell differentiation, proliferation and apoptosis. In nerve cells, little is known about their relative contribution to the pathways which control cell physiology, including cell death. Neoplastic transformation of avian neuroretina cells by p60 {sup v-src} tyrosine kinase results in dramatic morphological changes and deregulation of apoptosis. To identify the proteases involved in the cellular response to p60 {sup v-src}, we evaluated the effect of specific inhibitors of caspases, calpains and the proteasome on cell shape changes and apoptosis induced by p60 {sup v-src} inactivation in quail neuroretina cells transformed by tsNY68, a thermosensitive strain of Rous sarcoma virus. We found that the ubiquitin-proteasome pathway is recruited early after p60 {sup v-src} inactivation and is critical for morphological changes, whereas caspases are essential for cell death. This study provides evidence that distinct intracellular proteases are involved in the control of the morphology and fate of v-src-transformed cells.

  1. Xanthohumol induces apoptosis and S phase cell cycle arrest in A549 non-small cell lung cancer cells

    PubMed Central

    Yong, Wai Kuan; Ho, Yen Fong; Malek, Sri Nurestri Abd

    2015-01-01

    Background: Xanthohumol, a major prenylated chalcone found in female hop plant, Humulus lupulus, was reported to have various chemopreventive and anti-cancer properties. However, its apoptotic effect on human alveolar adenocarcinoma cell line (A549) of non-small cell lung cancer (NSCLC) was unknown. Objective: This study aimed to investigate the effects of xanthohumol on apoptosis in A549 human NSCLC cells. Materials and Methods: A549 cell proliferation was determined by sulforhodamine B assay. Morphological changes of the cells were studied via phase contrast and fluorescent microscopy. Induction of apoptosis was assessed by Annexin-V fluorescein isothiocyanate/propidium iodide (Annexin V-FITC/PI) staining, DNA fragmentation (TUNEL) assay mitochondrial membrane potential assay, cell cycle analysis, and caspase activity studies. Results: Xanthohumol was found to decrease cell proliferation in A549 cells but had relatively low cytotoxicity on normal human lung fibroblast cell line (MRC-5). Typical cellular and nuclear apoptotic features were also observed in A549 cells treated with xanthohumol. Onset of apoptosis in A549 cells was further confirmed by externalization of phosphatidylserine, changes in mitochondrial membrane potential, and DNA fragmentation in the cells after treatment. Xanthohumol induced accumulation of cells in sub G1 and S phase based on cell cycle analysis and also increased the activities of caspase-3, -8, and -9. Conclusion: This work suggests that xanthohumol as an apoptosis inducer, may be a potent therapeutic compound for NSCLC. PMID:26664015

  2. Zinc Induces Apoptosis of Human Melanoma Cells, Increasing Reactive Oxygen Species, p53 and FAS Ligand.

    PubMed

    Provinciali, Mauro; Pierpaoli, Elisa; Bartozzi, Beatrice; Bernardini, Giovanni

    2015-10-01

    The aim of this study was to examine the in vitro effect of zinc on the apoptosis of human melanoma cells, by studying the zinc-dependent modulation of intracellular levels of reactive oxygen species (ROS) and of p53 and FAS ligand proteins. We showed that zinc concentrations ranging from 33.7 μM to 75 μM Zn(2+) induced apoptosis in the human melanoma cell line WM 266-4. This apoptosis was associated with an increased production of intracellular ROS, and of p53 and FAS ligand protein. Treatment of tumor cells with the antioxidant N-acetylcysteine was able to prevent Zn(2+)-induced apoptosis, as well as the increase of p53 and FAS ligand protein induced by zinc. Zinc induces apoptosis in melanoma cells by increasing ROS and this effect may be mediated by the ROS-dependent induction of p53 and FAS/FAS ligand. PMID:26408691

  3. Targeting early B-cell receptor signaling induces apoptosis in leukemic mantle cell lymphoma

    PubMed Central

    2013-01-01

    Background We previously showed that B-cell receptor (BCR) signaling pathways are important for in vitro survival of mantle cell lymphoma (MCL) cells. To further identify early BCR-activated signaling pathways involved in MCL cell survival, we focused our study on BCR-proximal kinases such as LYN whose dysregulations could contribute to the aggressive course of MCL. Methods Primary MCL cells were isolated from 14 leukemic patients. Early BCR-induced genes were identified by qRT-PCR array. The basal and BCR-induced phosphorylation of LYN and JNK were evaluated by immunoblottting. Cell survival signals were evaluated by apoptosis using flow cytometry. Results We showed that LYN was constitutively phosphorylated in MCL cell lines and in 9/10 leukemic MCL cases. Treatment with dasatinib or with a specific inhibitor of Src kinases such as PP2 suppressed constitutive LYN activation and increased in vitro spontaneous apoptosis of primary MCL cells. BCR engagement resulted in an increase of LYN phosphorylation leading to activation of c-JUN NH2-terminal kinase (JNK) and over-expression of the early growth response gene-1 (EGR-1). Inhibition of JNK with SP600125 induced apoptosis and reduced level of basal and BCR-induced expression of EGR-1. Furthermore, decreasing EGR1 expression by siRNA reduced BCR-induced cell survival. Treatment with PP2 or with dasatinib suppressed BCR-induced LYN and JNK phosphorylation as well as EGR-1 upregulation and is associated with a decrease of cell survival in all cases analysed. Conclusions This study highlights the importance of BCR signaling in MCL cell survival and points out to the efficiency of kinase inhibitors in suppressing proximal BCR signaling events and in inducing apoptosis. PMID:23422267

  4. Wavelength-dependent backscattering measurements for quantitative monitoring of apoptosis, Part 1: early and late spectral changes are indicative of the presence of apoptosis in cell cultures

    NASA Astrophysics Data System (ADS)

    Mulvey, Christine S.; Zhang, Kexiong; Liu, Wei-Han Bobby; Waxman, David J.; Bigio, Irving J.

    2011-11-01

    Apoptosis, a form of programmed cell death with unique morphological and biochemical features, is dysregulated in cancer and is activated by many cancer chemotherapeutic drugs. Noninvasive assays for apoptosis in cell cultures can aid in screening of new anticancer agents. We have previously demonstrated that elastic scattering spectroscopy can monitor apoptosis in cell cultures. In this report we present data on monitoring the detailed time-course of scattering changes in a Chinese hamster ovary (CHO) and PC-3 prostate cancer cells treated with staurosporine to induce apoptosis. Changes in the backscattering spectrum are detectable within 10 min, and continue to progress up to 48 h after staurosporine treatment, with the magnitude and kinetics of scattering changes dependent on inducer concentration. Similar responses were observed in CHO cells treated with several other apoptosis-inducing protocols. Early and late scattering changes were observed under conditions shown to induce apoptosis via caspase activity assay and were absent under conditions where apoptosis was not induced. Finally, blocking caspase activity and downstream apoptotic morphology changes prevented late scattering changes. These observations demonstrate that early and late changes in wavelength-dependent backscattering correlate with the presence of apoptosis in cell cultures and that the late changes are specific to apoptosis.

  5. Amyloid beta-peptide induces cell monolayer albumin permeability, impairs glucose transport, and induces apoptosis in vascular endothelial cells.

    PubMed

    Blanc, E M; Toborek, M; Mark, R J; Hennig, B; Mattson, M P

    1997-05-01

    Amyloid beta-peptide (A beta) is deposited as insoluble fibrils in the brain parenchyma and cerebral blood vessels in Alzheimer's disease (AD). In addition to neuronal degeneration, cerebral vascular alterations indicative of damage to vascular endothelial cells and disruption of the blood-brain barrier occur in AD. Here we report that A beta25-35 can impair regulatory functions of endothelial cells (ECs) from porcine pulmonary artery and induce their death. Subtoxic exposures to A beta25-35 induced albumin transfer across EC monolayers and impaired glucose transport into ECs. Cell death induced by A beta25-35 was of an apoptotic form, characterized by DNA condensation and fragmentation, and prevented by inhibitors of macromolecular synthesis and endonucleases. The effects of A beta25-35 were specific because A beta1-40 also induced apoptosis in ECs with the apoptotic cells localized to the microenvironment of A beta1-40 aggregates and because astrocytes did not undergo similar changes after exposure to A beta25-35. Damage and death of ECs induced by A beta25-35 were attenuated by antioxidants, a calcium channel blocker, and a chelator of intracellular calcium, indicating the involvement of free radicals and dysregulation of calcium homeostasis. The data show that A beta induces increased permeability of EC monolayers to macromolecules, impairs glucose transport, and induces apoptosis. If similar mechanisms are operative in vivo, then A beta and other amyloidogenic peptides may be directly involved in vascular EC damage documented in AD and other disorders that involve vascular amyloid accumulation. PMID:9109512

  6. Apaf-1 and caspase-9 are required for cytokine withdrawal-induced apoptosis of mast cells but dispensable for their functional and clonogenic death.

    PubMed

    Marsden, Vanessa S; Kaufmann, Thomas; O'reilly, Lorraine A; Adams, Jerry M; Strasser, Andreas

    2006-03-01

    Cytokines promote survival of mast cells by inhibiting apoptotic pathways regulated by the Bcl-2 protein family. We previously showed that lymphocyte apoptosis can proceed via a Bcl-2-inhibitable pathway independent of the canonical initiator caspase, caspase-9, and its adaptor, Apaf-1. Here we report that mast cells lacking caspase-9 or Apaf-1 are refractory to apoptosis after cytotoxic insults but still lose effector function and ability to proliferate. In response to cytokine deprivation or DNA damage, fetal liver-derived mast cells lacking Apaf-1 or caspase-9 failed to undergo apoptosis. Nevertheless, the cytokine-starved cells were not functionally alive, because, unlike those overexpressing Bcl-2, they could not degranulate on Fcepsilon receptor stimulation or resume proliferation on re-addition of cytokine. Furthermore, mast cells lacking Apaf-1 or caspase-9 had no survival advantage over wild-type counterparts in vivo. These results indicate that the Apaf-1/caspase-9-independent apoptotic pathway observed in lymphocytes is ineffective in cytokine-deprived mast cells. However, although Apaf-1 and caspase-9 are essential for mast cell apoptosis, neither is required for the functional or clonogenic death of the cells, which may be due to mitochondrial dysfunction. PMID:16291596

  7. In vivo effects of thyroid hormone, corticosteroids and prolactin on cell proliferation and apoptosis in the anterior intestine of the euryhaline mudskipper (Periophthalmus modestus).

    PubMed

    Takahashi, Hideya; Takahashi, Akiyoshi; Sakamoto, Tatsuya

    2006-10-01

    We have previously shown that anterior intestinal epithelium of the euryhaline mudskipper (Periophthalmus modestus) undergoes apoptosis during seawater (SW) acclimation, whereas elevated cell proliferation was observed in freshwater (FW)-acclimated fish. To understand the possible endocrine regulation of the gastrointestinal cell turnover during salinity acclimation, we examined the ratios of apoptotic and proliferating cells in the anterior intestine of one-third SW-acclimated mudskipper treated with triiodothyronine (T3), cortisol, 11-deoxycorticosterone (DOC, the putative teleostean mineralocorticoid), or prolactin (PRL). In situ nick end labeling of genomic DNA (TUNEL) and immunohistochemistry of proliferating cells nuclear antigen (PCNA) were used as indicators of apoptosis and cell proliferations, respectively. Cortisol significantly elevated apoptosis (P<0.05) in the epithelia and connective tissues and also stimulated the epithelial cell proliferation (P<0.05). PRL induced epithelial cell proliferation (P<0.05), but did not affect apoptotic status of the intestinal epithelium. Neither T3 nor DOC had any impact on cell proliferation or apoptosis. Together, our results suggest a role for cortisol and PRL in the regulation of anterior intestinal epithelial turnover during salinity acclimation in this species. PMID:16857212

  8. Emodin induces apoptosis of human breast cancer cells by modulating the expression of apoptosis-related genes

    PubMed Central

    ZU, CONG; ZHANG, MINGDI; XUE, HUI; CAI, XIAOPENG; ZHAO, LEI; HE, ANNING; QIN, GUANGYUAN; YANG, CHUNSHU; ZHENG, XINYU

    2015-01-01

    The aim of this study was to investigate the effects of emodin on the proliferation of human breast cancer cells Bcap-37 and ZR-75-30. Cell viability following emodin treatment was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The effects of emodin on apoptosis were determined by flow cytometry using Annexin V-fluorescein isothiocyanate and propidium iodide staining. Quantitative polymerase chain reaction and western blot analysis were used to determine changes in the expression of apoptotic genes and protein, respectively. The effect of emodin on the invasiveness of breast cancer cells was evaluated by Matrigel invasion assay. Treatment of breast cancer cells Bcap-37 and ZR-75-30 with emodin was observed to inhibit the growth and induced apoptosis in a time- and dose-dependent manner. Emodin reduced the level of Bcl-2 and increased levels of cleaved caspase-3, PARP, p53 and Bax. These findings indicate that emodin induces growth inhibition and apoptosis in human breast cancer cells. Emodin may be a potential therapeutic agent for the treatment of breast cancer. PMID:26722264

  9. Protease nexin 1 induces apoptosis of prostate tumor cells through inhibition of X-chromosome-linked inhibitor of apoptosis protein

    PubMed Central

    Zhou, Jianfeng; Li, Chunrui; Huang, Liang; Xin, Xiangke; He, Jing; Allen, Joshua E.; El-Deiry, Wafik S.; Cao, Yunhong; Muschel, Ruth J.; Xu, Danmei

    2015-01-01

    Protease nexin 1 (PN1) is an endogenous serine protease inhibitor (SERPIN), expressed at high levels in the prostate, and capable of inhibiting the proliferation of prostate cancer cells. We previously showed that PN1-uPA complexes inhibited Sonic Hedgehog (SHH) signalling through engagement of the LRP receptor. Here, we describe an alternative anti-proliferative mechanism through which PN1 expression leads to apoptosis. In prostate cancer cells, increased expression of PN1 led to substantial reduction of XIAP levels and apoptosis mediated through the uPAR, but not the LRP receptor. The alterations in XIAP were effected in two ways 1) via alteration in the NF-κB pathway, a pathway known to signal XIAP transcription and 2) by promoting XIAP instability. The AKT pathway is known to phosphorylate XIAP at serine 87 leading to protein stability and PN1 expression is shown to interfere with this process. As a result of both mechanisms, programmed cell death is substantially increased. Consistent with these observations, reduced PN1 protein correlated with elevated p65/XIAP expression and with higher Gleason scores in human prostate tissue arrays. Thus, PN1 expression appears to differentially down-regulate distinct oncogenic pathways depending upon the cell surface receptor engaged by its complexes and demonstrates a novel molecular mechanism by which the protein can promote tumor cell apoptosis. PMID:25686839

  10. Human monocyte-derived macrophages infected with virulent Shigella flexneri in vitro undergo a rapid cytolytic event similar to oncosis but not apoptosis.

    PubMed Central

    Fernandez-Prada, C M; Hoover, D L; Tall, B D; Venkatesan, M M

    1997-01-01

    Infection of human monocyte-derived macrophages in vitro with virulent Shigella flexneri resulted in cell death which involved rupture of the plasma membrane, cell swelling, disintegration of ultrastructure, and generalized karyolysis. These features bore resemblance to oncosis and are in striking contrast to previously described observations of mouse macrophages, where a similar infection by virulent Shigella resulted in cell death by apoptosis. Cell death by oncosis in human macrophages was confirmed by lactate dehydrogenase release, light microscopy, electron microscopy, terminal deoxynucleotidyltransferase end labeling of DNA ends, DNA fragmentation assays, and fluorescence-activated cell sorter analysis of propidium-labeled nuclei. Thus, the phenomena of cell death induced by virulent Shigella in human and mouse macrophages reflect different biochemical pathways. Interleukin-1beta (IL-1beta) was released in culture supernatants of human macrophages infected with virulent bacteria. Inhibition with IL-1beta-converting enzyme inhibitors indicated, however, that this release occurred as a passive event of cell lysis. The patterns of intracellular survival of Shigella strains within human and mouse macrophages reflect differences that exist not only between Shigella serotypes but also between the two different macrophage cell types. PMID:9119491

  11. The Effect of NRAGE on cell cycle and apoptosis of human dental pulp cells and MDPC-23

    PubMed Central

    Wu, Qi; Qi, Shengcai; Ma, Ji; Chen, Fubo; Chen, Jing; Li, Jing; Zhang, Xu; Xu, Yuanzhi; Pan, Qiuhui; Wang, Raorao

    2015-01-01

    Objectives: Neurotrophin receptor-mediated melanoma antigen-encoding gene homology (NRAGE) is an important regulator of proliferation, cell cycle arrest and apoptosis. Our previous study showed that NRAGE is an important regulator of proliferation and odontogenic differentiation of mouse dental pulp cells. This study aimed to investigate the effects of NRAGE on the cell cycle and apoptosis on human dental pulp cells (hDPCs) and MDPC-23. Materials and methods: Cells were infected by recombinant lentivirus to stably knockdown the expression of NRAGE, then the biological effects of NRAGE on the MDPC-23 was detected. The cell cycle distributions and apoptosis of hDPCs and MCPC-23 were performed by flow cytometric analysis. Simultaneously, the cell cycle and apoptosis were also detected after cells treated with IKK inhibitor. Results: The mRNA and protein levels of NRAGE decreased significantly after infected by recombinant lentivirus. Knockdown of NRAGE inhibited the apoptosis in hDPCs and MCPC-23. Knockdown of NRAGE show significantly G0G1 arrest in hDPCs, while no significantly difference in MDPC-23. Meanwhile, Knockdown of NRAGE activated the NF-κB signaling pathway. After treated with IKK inhibitor, the effect of NRAGE knockdown on apoptosis was reversed in both hDPCs and MDPC-23. Conclusion: NRAGE is a potent regulator for cell cycle and apoptosis of hDPCs. Knockdown of NRAGE inhibited apoptosis of hDPCs and MDPC-23 through the NF-κB signaling pathway. PMID:26379857

  12. Cyclophosphamide-induced apoptosis in COV434 human granulosa cells involves oxidative stress and glutathione depletion.

    PubMed

    Tsai-Turton, Miyun; Luong, Brian T; Tan, Youming; Luderer, Ulrike

    2007-07-01

    The anticancer drug cyclophosphamide induces granulosa cell apoptosis and is detoxified by glutathione (GSH) conjugation. We previously showed that both cyclophosphamide treatment and GSH depletion induced granulosa cell apoptosis in rats, but the role of GSH in apoptosis in human ovarian cells has not been studied. Using the COV434 human granulosa cell line, we tested the hypotheses that (1) GSH depletion or treatment with 4-hydroperoxycyclophosphamide (4HC), a preactivated form of cyclophosphamide, induces apoptosis, (2) GSH depletion potentiates 4HC-induced apoptosis, and (3) 4HC-induced apoptosis is mediated by GSH depletion and oxidative stress. Cells were treated with buthionine sulfoximine (BSO), a specific inhibitor of GSH synthesis, with or without follicle stimulating hormone (FSH) or serum. A significant increase in the number of apoptotic cells, assessed by terminal deoxynucleotidyl transferase-mediated deoxy-uridine triphosphate nick-end labeling (TUNEL) and Hoechst 33342 staining, occurred with BSO treatment. Treatment with 4HC dose-dependently induced apoptosis by TUNEL, Hoechst staining, and caspase 3 activation. Treatment with 4HC caused an increase in reactive oxygen species generation, measured by dichlorofluorescein fluorescence, oxidative DNA damage, measured by 8-hydroxyguanosine immunostaining, and an oxidation of the redox potential for the oxidized glutathione/reduced glutathione couple. Total intracellular GSH declined after 4HC treatment, preceding the onset of cell death. Treatment with antioxidants inhibited 4HC-induced apoptosis. Combined treatment with BSO and 4HC caused greater induction of apoptosis than either treatment alone. These findings are consistent with roles for oxidative stress and GSH depletion in mediating the induction of apoptosis in COV434 cells by cyclophosphamide. PMID:17434952

  13. TGEV nucleocapsid protein induces cell cycle arrest and apoptosis through activation of p53 signaling

    SciTech Connect

    Ding, Li; Huang, Yong; Du, Qian; Dong, Feng; Zhao, Xiaomin; Zhang, Wenlong; Xu, Xingang; Tong, Dewen

    2014-03-07

    Highlights: • TGEV N protein reduces cell viability by inducing cell cycle arrest and apoptosis. • TGEV N protein induces cell cycle arrest and apoptosis by regulating p53 signaling. • TGEV N protein plays important roles in TGEV-induced cell cycle arrest and apoptosis. - Abstract: Our previous studies showed that TGEV infection could induce cell cycle arrest and apoptosis via activation of p53 signaling in cultured host cells. However, it is unclear which viral gene causes these effects. In this study, we investigated the effects of TGEV nucleocapsid (N) protein on PK-15 cells. We found that TGEV N protein suppressed cell proliferation by causing cell cycle arrest at the S and G2/M phases and apoptosis. Characterization of various cellular proteins that are involved in regulating cell cycle progression demonstrated that the expression of N gene resulted in an accumulation of p53 and p21, which suppressed cyclin B1, cdc2 and cdk2 expression. Moreover, the expression of TGEV N gene promoted translocation of Bax to mitochondria, which in turn caused the release of cytochrome c, followed by activation of caspase-3, resulting in cell apoptosis in the transfected PK-15 cells following cell cycle arrest. Further studies showed that p53 inhibitor attenuated TGEV N protein induced cell cycle arrest at S and G2/M phases and apoptosis through reversing the expression changes of cdc2, cdk2 and cyclin B1 and the translocation changes of Bax and cytochrome c induced by TGEV N protein. Taken together, these results demonstrated that TGEV N protein might play an important role in TGEV infection-induced p53 activation and cell cycle arrest at the S and G2/M phases and apoptosis occurrence.

  14. Confocal Raman data analysis enables identifying apoptosis of MCF-7 cells caused by anticancer drug paclitaxel

    NASA Astrophysics Data System (ADS)

    Salehi, Hamideh; Middendorp, Elodie; Panayotov, Ivan; Dutilleul, Pierre-Yves Collard; Vegh, Attila-Gergely; Ramakrishnan, Sathish; Gergely, Csilla; Cuisinier, Frederic

    2013-05-01

    Confocal Raman microscopy is a noninvasive, label-free imaging technique used to study apoptosis of live MCF-7 cells. The images are based on Raman spectra of cells components, and their apoptosis is monitored through diffusion of cytochrome c in cytoplasm. K-mean clustering is used to identify mitochondria in cells, and correlation analysis provides the cytochrome c distribution inside the cells. Our results demonstrate that incubation of cells for 3 h with 10 μM of paclitaxel does not induce apoptosis in MCF-7 cells. On the contrary, incubation for 30 min at a higher concentration (100 μM) of paclitaxel induces gradual release of the cytochrome c into the cytoplasm, indicating cell apoptosis via a caspase independent pathway.

  15. Antiproliferative and cell apoptosis-inducing activities of compounds from Buddleja davidii in Mgc-803 cells

    PubMed Central

    2012-01-01

    Background Buddleja davidii is widely distributed in the southwestern region of China. We have undertaken a systematic analysis of B. davidii as a Chinese traditional medicine with anticancer activity by isolating natural products for their activity against the human gastric cancer cell line Mgc-803 and the human breast cancer cell line Bcap-37. Results Ten compounds were extracted and isolated from B. davidii, among which colchicine was identified in B. davidii for the first time. The inhibitory activities of these compounds were investigated in Mgc-803, Bcap-37 cells in vitro by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay, and the results showed that luteolin and colchicine had potent inhibitory activities against the growth of Mgc-803 cells. Subsequent fluorescence staining and flow cytometry analysis indicated that these two compounds could induce apoptosis in Mgc-803 cells. The results also showed that the percentages of early apoptotic cells (Annexin V+/PI-, where PI is propidium iodide) and late apoptotic cells (Annexin V+/PI+) increased in a dose- and time-dependent manner. After 36 h of incubation with luteolin at 20 μM, the percentages of cells were approximately 15.4% in early apoptosis and 43.7% in late apoptosis; after 36 h of incubation with colchicine at 20 μM, the corresponding values were 7.7% and 35.2%, respectively. Conclusions Colchicine and luteolin from B. davidii have potential applications as adjuvant therapies for treating human carcinoma cells. These compounds could also induce apoptosis in tumor cells. PMID:22938042

  16. The molecular signature of CD8+ T cells undergoing deletional tolerance

    PubMed Central

    Rao, Sudha; Smyth, Gordon K.; Juelich, Torsten; Denyer, Gareth S.; Davey, Gayle M.; Strasser, Andreas

    2009-01-01

    Peripheral tolerance induction is critical for the maintenance of self-tolerance and can be mediated by immunoregulatory T cells or by direct induction of T-cell anergy or deletion. Although the molecular processes underlying anergy have been extensively studied, little is known about the molecular basis for peripheral T-cell deletion. Here, we determined the gene expression signature of peripheral CD8+ T cells undergoing deletional tolerance, relative to those undergoing immunogenic priming or lymphopenia-induced proliferation. From these data, we report the first detailed molecular signature of cells undergoing deletion. Consistent with defective cytolysis, these cells exhibited deficiencies in granzyme up-regulation. Furthermore, they showed antigen-driven Bcl-2 down-regulation and early up-regulation of the proapoptotic protein Bim, consistent with the requirement of this BH3-only protein for peripheral T-cell deletion. Bim up-regulation was paralleled by defective interleukin-7 receptor α (IL-7Rα) chain reexpression, suggesting that Bim-dependent death may be triggered by loss of IL-7/IL-7R signaling. Finally, we observed parallels in molecular signatures between deletion and anergy, suggesting that these tolerance pathways may not be as molecularly distinct as previously surmised. PMID:19204323

  17. Glycoprotein of Nonpathogenic Rabies Viruses Is a Key Determinant of Human Cell Apoptosis

    PubMed Central

    Préhaud, Christophe; Lay, Stéphanie; Dietzschold, Bernhard; Lafon, Monique

    2003-01-01

    We showed that, unlike pathogenic rabies virus (RV) strain CVS, attenuated RV strain ERA triggers the caspase-dependent apoptosis of human cells. Furthermore, we observed that the induction of apoptosis is correlated with a particular virus antigen distribution: the overexpression of the viral G protein on the cell surface, with continuous localization on the cytoplasmic membrane, and large cytoplasmic inclusions of the N protein. To determine whether one of these two major RV proteins (G and N proteins) triggers apoptosis, we constructed transgenic Jurkat T-cell lines that drive tetracycline-inducible gene expression to produce the G and N proteins of ERA and CVS individually. The induction of ERA G protein (G-ERA) expression but not of ERA N protein expression resulted in apoptosis, and G-ERA was more efficient at triggering apoptosis than was CVS G protein. To test whether other viral proteins participated in the induction of apoptosis, human cells were infected with recombinant RV in which the G protein gene from the attenuated strain had been replaced by its virulent strain counterpart (CVS). Only RV containing the G protein from the nonpathogenic RV strain was able to trigger the apoptosis of human cells. Thus, the ability of RV strains to induce apoptosis is largely determined by the viral G protein. PMID:12970438

  18. Agarol, an ergosterol derivative from Agaricus blazei, induces caspase-independent apoptosis in human cancer cells.

    PubMed

    Shimizu, Takamitsu; Kawai, Junya; Ouchi, Kenji; Kikuchi, Haruhisa; Osima, Yoshiteru; Hidemi, Rikiishi

    2016-04-01

    Agaricus blazei (A. blazei) is a mushroom with many biological effects and active ingredients. We purified a tumoricidal substance from A. blazei, an ergosterol derivative, and named it 'Agarol'. Cytotoxic effects of Agarol were determined by the MTT assay using A549, MKN45, HSC-3, and HSC-4 human carcinoma cell lines treated with Agarol. Apoptosis was detected by flow cytometry analysis. Reactive oxygen species (ROS) levels and mitochondria membrane potential (∆ψm) were also determined by flow cytometry. Western blot analysis was used to quantify the expression of apoptosis-related proteins. Agarol predominantly induced apoptosis in two p53-wild cell lines (A549 and MKN45) compared to the other p53-mutant cell lines (HSC-3 and HSC-4). Further mechanistic studies revealed that induction of apoptosis is associated with increased generation of ROS, reduced ∆ψm, release of apoptosis-inducing factor (AIF) from the mitochondria to the cytosol, upregulation of Bax, and downregulation of Bcl-2. Caspase-3 activities did not increase, and z-VAD-fmk, a caspase inhibitor, did not inhibit the Agarol-induced apoptosis. These findings indicate that Agarol induces caspase-independent apoptosis in human carcinoma cells through a mitochondrial pathway. The in vivo anticancer activity of Agarol was confirmed in a xenograft murine model. This study suggests a molecular mechanism by which Agarol induces apoptosis in human carcinoma cells and indicates the potential use of Agarol as an anticancer agent. PMID:26893131

  19. Zinc protects human kidney cells from depleted uranium-induced apoptosis.

    PubMed

    Hao, Yuhui; Ren, Jiong; Liu, Cong; Li, Hong; Liu, Jing; Yang, Zhangyou; Li, Rong; Su, Yongping

    2014-03-01

    Depleted uranium (DU) is a weak radioactive heavy metal, and zinc (Zn) is an effective antidote to heavy metal poisoning. However, the effect of Zn on DU-induced cytotoxicity and apoptosis is not completely understood. The purpose of this study was to evaluate the effect of Zn on DU-induced cell apoptosis in human kidney cells (HK-2) and explore its molecular mechanism. Pre-treatment with Zn significantly inhibited DU-induced apoptosis. It reduced the formation of reactive oxygen species in the cells, increased the catalase (CAT) and glutathione (GSH) concentrations, suppressed the DU-induced soluble Fas receptor (sFasR) and soluble Fas ligand (sFasL) overexpression, suppressed the release of cytochrome c and apoptosis inhibitor factor (AIF) from mitochondria to cytoplasm, inhibited the activation of caspase-9, caspase-8 and caspase-3, and induced metallothionein (MT) expression. Furthermore, exogenous MT effectively inhibited DU-induced cell apoptosis. In conclusion, mitochondrial and FasR-mediated apoptosis pathways contribute to DU-induced apoptosis in HK-2 cells. Through independent mechanisms, such as indirect antioxidant effects, inhibition of the activation of caspase-9, caspase-8 and caspase-3, and induction of MT expression, Zn inhibits DU-induced apoptosis. PMID:24330236

  20. Interferon-gamma sensitizes colonic epithelial cell lines to physiological and therapeutic inducers of colonocyte apoptosis.

    PubMed

    O'Connell, J; Bennett, M W; Nally, K; O'Sullivan, G C; Collins, J K; Shanahan, F

    2000-12-01

    Homeostasis in the colonic epithelium is achieved by a continuous cycle of proliferation and apoptosis, in which imbalances are associated with disease. Inflammatory bowel disease (IBD) and colon cancer are associated with either excessive or insufficient apoptosis of colonic epithelial cells, respectively. By using two colonic epithelial cell lines, HT29 and SW620, we investigated how the epithelial cell's sensitivity to apoptosis was regulated by the proinflammatory cytokine interferon-gamma (IFN-gamma). We found that IFN-gamma sensitized HT29 cells, and to a lesser extent SW620, to diverse inducers of apoptosis of physiologic or therapeutic relevance to the colon. These apoptosis inducers included Fas (CD95/APO-1) ligand (FasL), short-chain fatty acids, and chemotherapeutic drugs. The extent of IFN-gamma-mediated apoptosis sensitization in these two cell lines correlated well with the degree of IFN-gamma-mediated upregulation of the proapoptotic protease caspase-1. Although IFN-gamma alone effectively sensitized HT29 cells to apoptosis, inclusion of the protein synthesis inhibitor cyclohexamide (CHX) during apoptotic challenge was necessary for maximal sensitization of SW620. The requirement of CHX to sensitize SW620 cells to apoptosis implies a need to inhibit translation of antiapoptotic proteins absent from HT29. In particular, the antiapoptotic protein Bcl-2 was strongly expressed in SW620 cells but absent from HT29. Our results indicate that IFN-gamma increases the sensitivity of colonic epithelial cells to diverse apoptotic stimuli in concert, via upregulation of caspase-1. Our findings implicate caspase-1 and Bcl-2 as important central points of control determining the general sensitivity of colonic epithelial cells to apoptosis. PMID:11056003

  1. N-acetyl-L-cysteine inhibits bleomycin induced apoptosis in malignant testicular germ cell tumors.

    PubMed

    Kucuksayan, Ertan; Cort, Aysegul; Timur, Mujgan; Ozdemir, Evrim; Yucel, Suleyman Gultekin; Ozben, Tomris

    2013-07-01

    Antioxidants may prevent apoptosis of cancer cells via inhibiting reactive oxygen species (ROS). However, to date no study has been carried out to elucidate the effects of strong antioxidant N-acetylcysteine (NAC) on Bleomycin induced apoptosis in human testicular cancer (NTERA-2, NT2) cells. For this reason, we studied the effects of Bleomycin and NAC alone and in combination on apoptotic signaling pathways in NT2 cell line. We determined the cytotoxic effect of bleomycin on NT2 cells and measured apoptosis markers such as Caspase-3, -8, -9 activities and Bcl-2, Bax, Cyt-c, Annexin V-FTIC and PI levels in NT2 cells incubated with different agents for 24 h. Early apoptosis was determined using FACS assay. We found half of the lethal dose (LD50) of Bleomycin on NT2 cell viability as 400, 100, and 20 µg/ml after incubations for 24, 48, and 72 h, respectively. Incubation with bleomycin (LD50 ) and H2O2 for 24 h increased Caspase-3, -8, -9 activities, Cyt-c and Bax levels and decreased Bcl-2 levels. The concurrent incubation of NT2 cells with bleomycin/H2O2 and NAC (5 mM) for 24 h abolished bleomycin/H2O2-dependent increases in Caspase-3, -8, -9 activities, Bax and Cyt-c levels and bleomycin/H2O2-dependent decrease in Bcl-2 level. Our results indicate that bleomycin/H2O2 induce apoptosis in NT2 cells by activating mitochondrial pathway of apoptosis, while NAC diminishes bleomycin/H2O2 induced apoptosis. We conclude that NAC has antagonistic effects on Bleomycin-induced apoptosis in NT2 cells and causes resistance to apoptosis which is not a desired effect in eliminating cancer cells. PMID:23386420

  2. Interaction of TIM4 and TIM3 induces T helper 1 cell apoptosis.

    PubMed

    Ge, Rong-Ti; Zeng, Lu; Mo, Li-Hua; Xu, Ling-Zhi; Zhang, Huan-Ping; Yu, Hai-Qiong; Zhang, Min; Liu, Zhi-Gang; Liu, Zhan-Ju; Yang, Ping-Chang

    2016-04-01

    The T helper 1 (Th1) polarization plays a critical role in the pathogenesis of a number of inflammatory disorders in the body; the remedies in the correction of polarized Th1 cells are limited. This study aims to investigate the role of T cell immunoglobulin mucin domain molecule 4 (TIM4) in the induction of Th1 cell apoptosis. In this study, polarized Th1 cells were generated from naive Th1 cells from the mouse spleen. Recombinant TIM4 was added to the culture to stimulate the polarized Th1 cells. The apoptosis of Th1 cells was assessed by flow cytometry. The expression of FasL was analyzed by chromatin immunoprecipitation, real time RT-PCR, and Western blotting. The results showed that the polarized Th1 cells expressed high levels of TIM3. After exposure of the polarized Th1 cells to TIM4 in the culture, a complex of TIM3 and TIM4 was detected on the surface of Th1 cells, which induced the Th1 cell apoptosis. The engagement of TIM3 by TIM4 increased p300 phosphorylation in Th1 cells, which further increased the levels of Fas ligand in the cells and induced Th1 cell apoptosis. In conclusion, TIM4 binds TIM3 on the surface of polarized Th1 cells to induce Th1 cell apoptosis, which may contribute to the development of Th2-dominant immune disorders. PMID:26403707

  3. Huaier polysaccharide induces apoptosis in hepatocellular carcinoma cells through p38 MAPK

    PubMed Central

    Bao, Haidong; Liu, Peng; Jiang, Ke; Zhang, Xianbin; Xie, Long; Wang, Zhongyu; Gong, Peng

    2016-01-01

    The underlying mechanism of the antitumor activity of Huaier polysaccharide (HP) remains to be explored. The present study aimed to investigate the inhibitory effect of HP on hepatocellular carcinoma (HCC) cells, and to explore the possible mechanisms of its anticancer effect. Cell viability was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, while apoptotic nuclear changes were observed using Hoechst 33258 staining. The distribution of cell cycle and apoptosis were analyzed by flow cytometry, and western blotting was used to test the apoptotic pathways. Apoptosis and mitogen-activated protein kinase (MAPK) inhibitors were used to investigate the mechanism of apoptosis. HP triggered cell cycle arrest and apoptosis in HepG2 and Huh7 cells. Both the extrinsic and intrinsic apoptotic pathways were activated after HP treatment. Furthermore, HP enhanced the three major MAPK pathways (extracellular signal-regulated kinase, c-Jun N-terminal kinase and p38 MAPK) and inhibited the AKT/mechanistic target of rapamycin signaling pathway in HCC cells. Notably, the inactivation of p38 MAPK impaired the HP-induced cell death. HP exerted its antitumor effect on HCC cells through the regulation of the expression of the apoptosis-related proteins B-cell lymphoma (Bcl)-2, Bcl-2-associated X protein and survivin. The present study provides evidence that HP induces apoptosis in HCC cells and demonstrated the role of p38 MAPK in HP-triggered cancer cell death.

  4. Protection against apoptosis in chicken bursa and thymus cells by phorbol ester in vitro

    SciTech Connect

    Asakawa, J.; Thorbecke, G.J. )

    1991-03-15

    Programmed suicide or apoptosis, due to activation of endogenous nucleases, occurs in immature CD4{sup {minus}}85{sup {minus}} mammalian thymus cells. Like the thymus, the bursa of Fabricius is a site of massive lymphopoiesis accompanied by cell death in vivo. In the present study the authors have, therefore, examined whether chicken bursa and thymus cells exhibit apoptosis. Bursa and thymus cells from SC chickens, 4-10 weeks of age, were incubated for 8-24 hrs with various reagents. Genomic DNA was isolated, electrophoresed in 3% Nusieve agarose gels, and examined for patterns of DNA fragmentation. A laddering of DNA in multiples of 200 base pairs, indicative of apoptosis, was observed with both bursa and thymus cells. These patterns of DNA fragmentation from bursa cells could be prevented by adding phorbol myristic acetate during culture and, more effectively, by PMA plus ionomycin, but not by ionomycin alone or by anti-{mu}. PMA did not affect the patterns of DNA fragmentation seen with spleen cells. Addition of the protein kinase C inhibitor staurosporin inhibited the preventive effect of PMA on apoptosis. PMA also greatly promoted the survival of bursa cells in culture, as assayed by percentage cell death and by {sup 3}H-thymidine incorporation. It is concluded that bursa and thymus cells from the chicken exhibit apoptosis. The data further suggest that protein kinase C activation protects apoptosis in cultured bursa cells.

  5. Apoptosis Cell Death Effect of Scrophularia Variegata on Breast Cancer Cells via Mitochondrial Intrinsic Pathway

    PubMed Central

    Azadmehr, Abbas; Hajiaghaee, Reza; Baradaran, Behzad; Haghdoost-Yazdi, Hashem

    2015-01-01

    Purpose: Scrophularia variegata M. Beib. (Scrophulariaceae) is an Iranian medicinal plant which is used for various inflammatory disorders in traditional medicine. In this study we evaluated the anti-cancer and cytotoxic effects of the Scrophularia variegata (S. variegata) ethanolic extract on the human breast cancer cell line. Methods: The cytotoxicity effect of the extract on MCF-7 cells was evaluated by MTT assay. In addition, Caspase activity, DNA ladder and Cell death were evaluated by ELISA, gel electrophoresis and Annexin V-FITC/PI staining, respectively. Results: The S. variegata extract showed significant effect cytotoxicity on MCF-7 human breast cancer cell line. Treatment with the extract induced apoptosis on the breast cancer cells by cell cycle arrest in G2/M phase. The results indicated that cytotoxicity activity was associated with an increase of apoptosis as demonstrated by DNA fragmentation as well as an increase of the amount of caspase 3 and caspase 9. In addition, the phytochemical assay showed that the extract had antioxidant capacity and also flavonoids, phenolic compounds and phenyl propanoids were presented in the extract. Conclusion: Our findings indicated that S. variegata extract induced apoptosis via mitochondrial intrinsic pathway on breast cancer by cell cycle arrest in G2/M phase and an increase of caspase 3 and caspase 9. However future studies are needed. PMID:26504768

  6. Matrine-induced autophagy counteracts cell apoptosis via the ERK signaling pathway in osteosarcoma cells

    PubMed Central

    Ma, Kun; Huang, Man-Yu; Guo, Yan-Xing; Hu, Guo-Qiang

    2016-01-01

    The aim of the present study was to observe whether autophagy was induced by matrine, and to investigate the role of autophagy in the antitumor effects of matrine on human osteosarcoma MG-63 cells and its underlying mechanism. MG-63 cells were cultured in vitro in matrine at a concentration of 0.6, 0.8, 1.0 and 1.2 g/l for 0, 24, 48 and 72 h. A MTT assay was used to evaluate the proliferation inhibition of MG-63 cells by matrine, and Annexin V-fluorescein isothiocyanate/propidum iodide (PI) staining flow cytometry was used to analyze the apoptotic rate. Alterations in cell morphology was assessed by PI and Hoechst 33258 cell staining. Matrine-induced autophagy in MG-63 cells was confirmed by green fluorescent protein-microtubule-associated protein 1-light chain 3 (LC3) b transfection and fluorescence microscopy, and cell viability was investigated by MTT assay following inhibition of autophagy by chloroquine (CQ) pretreatment. The expression level of apoptosis-associated proteins B-cell lymphoma-2 (Bcl-2) and Bcl-2-like protein 4 (Bax), autophagy-associated LC3II protein, and the activation of extracellular signal-regulated kinase (ERK) was detected by western blotting. Cell proliferation was clearly inhibited by matrine in a dose- and time-dependent manner. Flow cytometry and Hoechst 33258/PI staining verified that matrine induced apoptosis in a time-dependent manner when cells were exposed to 1.1 g/l matrine; fluorescence microscopy demonstrated that green fluorescence puncta were enhanced with prolonged time of matrine incubation. Western blotting confirmed that the expression of pro-apoptosis-associated proteins Bax and LC3II, and phosphorylated-ERK were upregulated, and anti-apoptosis protein Bcl-2 was downregulated in a time-dependent manner following treatment with matrine. The cell viability of the matrine + CQ group was increased compared with the matrine group alone, which revealed that matrine treatment alone induced protective autophagy in MG-63 cells

  7. Induction of apoptosis in pancreatic cancer cells by vesicular stomatitis virus

    PubMed Central

    Felt, Sébastien A.; Moerdyk-Schauwecker, Megan J.; Grdzelishvili, Valery Z.

    2014-01-01

    Effective oncolytic virus (OV) therapy is dependent on the ability of replication-competent viruses to kill infected cancer cells. We previously showed that human pancreatic ductal adenocarcinoma (PDAC) cell lines are highly heterogeneous in their permissiveness to vesicular stomatitis virus (VSV), in part due to differences in type I interferon (IFN) signaling. Here, using ten human PDAC cell lines and three different VSV recombinants (expressing ΔM51 or wild type matrix protein), we examined cellular and viral factors affecting VSV-mediated apoptosis activation in PDACs. In most cell lines VSVs activated both extrinsic and intrinsic apoptosis pathways, and VSV-ΔM51 primarily activated the type II extrinsic pathway. In cells with defective IFN signaling, all VSV recombinants induced robust apoptosis, whereas VSV-ΔM51 was a more effective apoptosis activator in PDACs with virus-inducible IFN signaling. Three cell lines constitutively expressing high levels of IFN-stimulated genes (ISGs) were resistant to apoptosis under most experimental conditions, even when VSV replication levels were dramatically increased by Jak inhibitor I treatment. Two of these cell lines also poorly activated apoptosis when treated with Fas activating antibody, suggesting a general defect in apoptosis. PMID:25463614

  8. Bupivacaine induces apoptosis through caspase-dependent and -independent pathways in canine mammary tumor cells.

    PubMed

    Chiu, Yi-Shu; Cheng, Yeong-Hsiang; Lin, Sui-Wen; Chang, Te-Sheng; Liou, Chian-Jiun; Lai, Yu-Shen

    2015-06-01

    Local anesthetics have been reported to induce apoptosis in various cell lines. In this study, we showed that bupivacaine also induced apoptosis in DTK-SME cells, a vimentin(+)/AE1(+)/CK7(+)/HSP27(+), tumorigenic, immortalized, canine mammary tumor cell line. Bupivacaine induced apoptosis in DTK-SME cells in a time- and concentration-dependent manner. Apoptosis-associated morphological changes, including cell shrinkage and rounding, chromatin condensation, and formation of apoptotic bodies, were observed in the bupivacaine-treated DTK-SME cells. Apoptosis was further confirmed with annexin V staining, TUNEL staining, and DNA laddering assays. At the molecular level, the activation of caspases-3, -8, and -9 corresponded well to the degree of DNA fragmentation triggered by bupivacaine. We also demonstrated that the pan-caspase inhibitor, z-VAD-fmk, only partially inhibited the apoptosis induced by bupivacaine. Moreover, treated cells increased expression of endonuclease G, a death effector that acts independently of caspases. Our data suggested that bupivacaine-induced apoptosis occurs through both caspase-dependent and caspase-independent apoptotic pathways. PMID:25843897

  9. Leaf extracts from Nitraria retusa promote cell population growth of human cancer cells by inducing apoptosis

    PubMed Central

    2011-01-01

    Background In this report the phytochemical profile of Nitraria. Retusa (N. Retusa) leaf extracts were identified and their ability to induce apoptosis in human chronic myelogenous erythroleukaemia (K562) was evaluated. Methods Apoptosis of the human chronic myelogenous erythroleukaemia (K562) was evidenced by investigating DNA fragmentation, PARP cleavage and caspases 3 and 8 inducing activities, in the presence of N. retusa extracts. Results Our study revealed that the tested extracts from N. Retusa contain many useful bioactive compounds. They induced in a time-dependent manner the apoptosis the tested cancerous our cell line. This result was confirmed by ladder DNA fragmentation profile and PARP cleavage, as well as a release in caspase-3 and caspase-8 level. Conclusion Our results indicate that the tested compounds have a significant antiproliferative effect which may be due to their involvement in the induction of the extrinsic apoptosic pathway. PMID:22040460

  10. Induction of apoptosis by (-)-gossypol-enriched cottonseed oil in human breast cancer cells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Induction of apoptosis is one of the mechanisms of chemotherapeutic agents against breast cancer. In addition, recent studies have shown that diets containing polyphenolic components possess anticancer activities either in vitro or in vivo by inhibiting cell proliferation and inducing apoptosis. T...

  11. DHA induces apoptosis by altering the expression and cellular location of GRP78 in colon cancer cell lines.

    PubMed

    Fasano, Elena; Serini, Simona; Piccioni, Elisabetta; Toesca, Amelia; Monego, Giovanni; Cittadini, Achille R; Ranelletti, Franco O; Calviello, Gabriella

    2012-11-01

    n-3 polyunsaturated fatty acids exert growth-inhibitory and pro-apoptotic effects in colon cancer cells. We hypothesized that the anti-apoptotic glucose related protein of 78kDa (GRP78), originally described as a component of the unfolded protein response in endoplasmic reticulum (ER), could be a molecular target for docosahexaenoic acid (DHA) in these cells. GRP78 total and surface overexpression was previously associated with a poor prognosis in several cancers, whereas its down-regulation with decreased cancer growth in animal models. DHA treatment induced apoptosis in three colon cancer cell lines (HT-29, HCT116 and SW480), and inhibited their total and surface GRP78 expression. The cell ability to undergo DHA-induced apoptosis was inversely related to their level of GRP78 expression. The transfection of the low GRP78-expressing SW480 cells with GRP78-GFP cDNA significantly induced cell growth and inhibited the DHA-driven apoptosis, thus supporting the essential role of GRP78 in DHA pro-apoptotic effect. We suggest that pERK1/2 could be the first upstream target for DHA, and demonstrate that, downstream of GRP78, DHA may exert its proapoptotic role by augmenting the expression of the ER resident factors ERdj5 and inhibiting the phosphorylation of PKR-like ER kinase (PERK), known to be both physically associated with GRP78, and by activating caspase-4. Overall, the regulation of cellular GRP78 expression and location is suggested as a possible route through which DHA can exert pro-apoptotic and antitumoral effects in colon cancer cells. PMID:22898250

  12. Risks of packed red blood cell transfusion in patients undergoing cardiac surgery.

    PubMed

    Gerber, David R

    2012-12-01

    Packed red blood cell (PRBC) transfusion is common in patients undergoing cardiac surgery. Evidence has accumulated demonstrating that such patients can tolerate relatively low hemoglobins, and an extensive body of literature has developed demonstrating that patients undergoing such surgery who receive PRBC are at risk for several adverse outcomes including increased mortality, atrial fibrillation, and more postoperative infections, as well as numerous other complications. The PubMed database was searched for the English language literature on the topic of PRBC transfusion and outcomes in patients undergoing cardiac surgery, as well as alternatives to this intervention. Data were reviewed to assess the impact of transfusion in patients undergoing cardiac surgery on mortality, cardiac, infectious, and pulmonary, as well as a variety of miscellaneous complications. Patients receiving PRBC were consistently identified as being at higher risk for complications in all categories. The limited prospective data were consistent with the retrospective data, which comprised most of the literature. The preponderance of the literature suggests that patients undergoing cardiac surgery can tolerate lower hemoglobin/hematocrit values than traditionally appreciated. Most published data also indicate that PRBC transfusion should be reserved for patients with an identifiable clinical/physiologic indication fir this intervention, consistent with recent specialty society guidelines. PMID:22762927

  13. Impact of Mitochondria-Mediated Apoptosis in U251 Cell Cycle Arrest in G1 Stage and Caspase Activation

    PubMed Central

    Zhang, Lei; Liang, Peng; Zhang, Rui

    2015-01-01

    Background Most mitochondria-mediated apoptosis has some relevance to the cell cycle, but there is still a lack of investigations about U251 cell cycle in human brain glioma cells. In this study, we aimed to clarify the correlation of mitochondria-mediated apoptosis with the U251 cell cycle and its influence on apoptosis, through observing the impact of mitochondria-mediated apoptosis in U251cell specificity cycle arrest and Caspase activation. Material/Methods AnnexinV/PI and API were used to label the brain glioma cells for flow cytometry analysis of U251 cell apoptosis and cell cycle. RT-PCR and Western blot were performed to detect Caspase-3 and Caspase-9 activation. Results Peripheral blood in stationary phase is not sensitive to apoptosis induction, but U251 cells have obvious apoptosis. Mitochondria-mediated apoptosis mainly occurs in the G1 phase of the cell cycle. Caspase-3 and Caspase-9 mRNAs and proteins expression increased significantly after the cells were treated by mitochondrial apoptosis-related gene Bax induction. Conclusions Mitochondria-mediated apoptosis is related to the U251 cell cycle with specific G1 stage arrest. Caspase activation occurs in the process of cell apoptosis. PMID:26594875

  14. Evaluation of Circulating Tumor Cells and Serological Cell Death Biomarkers in Small Cell Lung Cancer Patients Undergoing Chemotherapy

    PubMed Central

    Hou, Jian-Mei; Greystoke, Alastair; Lancashire, Lee; Cummings, Jeff; Ward, Tim; Board, Ruth; Amir, Eitan; Hughes, Sarah; Krebs, Matthew; Hughes, Andrew; Ranson, Malcolm; Lorigan, Paul; Dive, Caroline; Blackhall, Fiona H.

    2009-01-01

    Serological cell death biomarkers and circulating tumor cells (CTCs) have potential uses as tools for pharmacodynamic blood-based assays and their subsequent application to early clinical trials. In this study, we evaluated both the expression and clinical significance of CTCs and serological cell death biomarkers in patients with small cell lung cancer. Blood samples from 88 patients were assayed using enzyme-linked immunosorbent assays for various cytokeratin 18 products (eg, M65, cell death, M30, and apoptosis) as well as nucleosomal DNA. CTCs (per 7.5 ml of blood) were quantified using Veridex CellSearch technology. Before therapeutic treatment, cell death biomarkers were elevated in patients compared with controls. CTCs were detected in 86% of patients; additionally, CD56 was detectable in CTCs, confirming their neoplastic origin. M30 levels correlated with the percentage of apoptotic CTCs. M30, M65, lactate dehydrogenase, and CTC number were prognostic for patient survival as determined by univariate analysis. Using multivariate analysis, both lactate dehydrogenase and M65 levels remained significant. CTC number fell following chemotherapy, whereas levels of serological cell death biomarkers peaked at 48 hours and fell by day 22, mirroring the tumor response. A 48-hour rise in nucleosomal DNA and M30 levels was associated with early response and severe toxicity, respectively. Our results provide a rationale to include the use of serological biomarkers and CTCs in early clinical trials of new agents for small cell lung cancer. PMID:19628770

  15. [Label-free monitoring 5-FU induced SW 620 cells apoptosis using FTIR microspectroscopy].

    PubMed

    Liu, Dong; Sun, Xue-Jun; Zhang, Chao; He, Sai; Du, Jun-Kai; Huo, Xiong-Wei; Zheng, Jian-Bao; Zhang, Shi-Yun; Zhang, Yuan-Fuz; Xu, Yi-Zhuang; Wu, Jin-Guang

    2013-12-01

    The aim of the present study was to evaluate Fourier transform infrared spectroscopy (FTIR) monitoring of biochemical changes in apoptosis cells. Different concentrations of 5-fluorouracil (5-FU) treated colon cancer cell lines SW620 were used to determine the optimum concentration of 5-FU IC50 by means of MTT assay. Cell starvation and 5-Fu synergistic cell cycle arrest was in G1 and S phase. FTIR combined with flow cytometry was applied to analysis of SW 620 cells and SW620 cells treated with 5-FU for 12h, 24h (early apoptosis) and 48 h (late apoptosis) respectively. The peak position and the intensity of all bands were measured and comparison was made between the SW620 and apoptotic SW620 cells. Apoptosis cells have following characteristics compared with SW620 cells (1) The band at 1 740 cm-1 is an C=O stretching vibration. Changes in these bands can reflect lipid changes, and relative peak intensity ratio 11740/11460 significantly increased (p<0. 05), indicating that the relative contents of lipid in apoptosis cells increased. (2) The band at the 1 410 cm-1 peak represents that C-H stretching related was increased to amino acid residues and shifted to higher wave numbers compared to other groups. I1410o/I 460 at early and late death phase was significantly increased, which suggests that the relative contents of amino acid residues in apoptosis cells increased (p <0. 05). New vibrational bands at 1 120 cm-1 appeared at 24 h and increased at 48 h compared with other groups. The 1 120 cm-1 absorption band is mainly due to ser, serine and threonine C-O(H) stretching vibration, and I1120/I 1460 significantly increased (p<0. 05), indicating that the relative quantity of amino acid residues in apoptosis cells increased due to that DNA unwinds the double helix. (3) 1 240 cm-1 is mainly due to the asymmetric stretching modes of phosphodiester groups shifting to higher wave number, illustrating that nucleic acid conformation was changed in apoptosis cells. (4) The band

  16. Genome surveillance in pluripotent stem cells: Low apoptosis threshold and efficient antioxidant defense

    PubMed Central

    Dannenmann, Benjamin; Lehle, Simon; Essmann, Frank; Schulze-Osthoff, Klaus

    2016-01-01

    ABSTRACT Pluripotent stem cells must be endowed with efficient genome surveillance. Here we describe the multiple mechanisms that ensure their genome integrity, including high susceptibility to apoptosis and efficient prevention of DNA lesions. In induced pluripotent stem cells, apoptosis hypersensitivity is mediated by increased expression of proapoptotic BCL-2 protein, whereas DNA damage is prevented by the upregulation of several antioxidant enzymes. Antioxidants might be therefore employed for safer stem cell therapies. PMID:27308586

  17. Nucleostemin Knockdown Sensitizes Hepatocellular Carcinoma Cells to Ultraviolet and Serum Starvation-Induced Apoptosis.

    PubMed

    Yuan, Fuwen; Cheng, Qian; Li, Guodong; Tong, Tanjun

    2015-01-01

    Nucleostemin (NS) is a GTP-binding protein that is predominantly expressed in embryonic and adult stem cells but not in terminally differentiated cells. NS plays an essential role in maintaining the continuous proliferation of stem cells and some types of cancer cells. However, the role of NS in hepatocellular carcinoma (HCC) remains unclear. Therefore, this study aimed to clarify the role of NS in HCC. First, we demonstrated high expression of NS in most HCC cell lines and liver cancer tissues. NS knockdown induced a severe decline in cell viability of MHCC97H cells as detected by MTT and cell proliferation assays. Next, we used ultraviolet (UV) and serum starvation-induced apoptosis models to investigate whether NS suppression or up-regulation affects HCC cell apoptosis. After UV treatment or serum starvation, apoptosis was strongly enhanced in MHCC97H and Bel7402 cells transfected with small interfering RNA against NS, whereas NS overexpression inhibited UV- and serum-induced apoptosis of HCC cells. Furthermore, after UV irradiation, inhibition of NS increased the expression of pro-apoptosis protein caspase 3 and decreased the expression of anti-apoptosis protein Bcl-2. A caspase 3 inhibitor could obviously prevent NS knockdown-induced apoptosis. In conclusion, our study demonstrated overexpression of NS in most HCC tissues compared with their matched surrounding tissues, and silencing NS promoted UV- and serum starvation-induced apoptosis of MHCC97H and Bel7402 cells. Therefore, the NS gene might be a potential therapeutic target of HCC. PMID:26517370

  18. Nucleostemin Knockdown Sensitizes Hepatocellular Carcinoma Cells to Ultraviolet and Serum Starvation-Induced Apoptosis

    PubMed Central

    Li, Guodong; Tong, Tanjun

    2015-01-01

    Nucleostemin (NS) is a GTP-binding protein that is predominantly expressed in embryonic and adult stem cells but not in terminally differentiated cells. NS plays an essential role in maintaining the continuous proliferation of stem cells and some types of cancer cells. However, the role of NS in hepatocellular carcinoma (HCC) remains unclear. Therefore, this study aimed to clarify the role of NS in HCC. First, we demonstrated high expression of NS in most HCC cell lines and liver cancer tissues. NS knockdown induced a severe decline in cell viability of MHCC97H cells as detected by MTT and cell proliferation assays. Next, we used ultraviolet (UV) and serum starvation-induced apoptosis models to investigate whether NS suppression or up-regulation affects HCC cell apoptosis. After UV treatment or serum starvation, apoptosis was strongly enhanced in MHCC97H and Bel7402 cells transfected with small interfering RNA against NS, whereas NS overexpression inhibited UV- and serum-induced apoptosis of HCC cells. Furthermore, after UV irradiation, inhibition of NS increased the expression of pro-apoptosis protein caspase 3 and decreased the expression of anti-apoptosis protein Bcl-2. A caspase 3 inhibitor could obviously prevent NS knockdown-induced apoptosis. In conclusion, our study demonstrated overexpression of NS in most HCC tissues compared with their matched surrounding tissues, and silencing NS promoted UV- and serum starvation-induced apoptosis of MHCC97H and Bel7402 cells. Therefore, the NS gene might be a potential therapeutic target of HCC. PMID:26517370

  19. Immunotoxin BL22 induces apoptosis in mantle cell lymphoma (MCL) cells dependent on Bcl-2 expression.

    PubMed

    Bogner, Christian; Dechow, Tobias; Ringshausen, Ingo; Wagner, Michaela; Oelsner, Madlen; Lutzny, Gloria; Licht, Thomas; Peschel, Christian; Pastan, Ira; Kreitman, Robert J; Decker, Thomas

    2010-01-01

    Mantle cell lymphoma (MCL) is an incurable mature B cell proliferation, combining the unfavourable clinical features of aggressive and indolent lymphomas. The blastic variant of MCL has an even worse prognosis and new treatment options are clearly needed. We analysed the effects of BL22, an immunotoxin composed of the Fv portion of an anti- CD22 antibody fused to a 38-kDa Pseudomonas exotoxin-A fragment on four MCL cell lines as well as on primary cells of four MCL patients. Apoptosis induction by BL22 was much more pronounced in MCL cell lines with low Bcl-2 expression (NCEB-1, JeKo-1 and JVM-2) compared to Granta-519 cells with high Bcl-2 expression. While the expression of the antiapoptotic protein Mcl-1 declined (NCEB-1, Granta-519), Bcl-2 levels remained unchanged in Granta-519 cells. However transfection of BCL2 cDNA into NCEB-1, JeKo-1 and JVM-2 cells significantly reduced BL22-mediated toxicity. Accordingly we examined the effects of Bcl-2 inactivation in Granta-519 cells using siRNA. Indeed, apoptosis induction was strongly enhanced in Granta-519 cells with silenced Bcl-2. Our results were confirmed in freshly isolated MCL-cells from patients with leukaemic MCL. We conclude that Bcl-2 expression is important for mediating resistance against the immunotoxin BL22 in MCL cells. PMID:19821820

  20. TRAP1 regulates cell cycle and apoptosis in thyroid carcinoma cells.

    PubMed

    Palladino, Giuseppe; Notarangelo, Tiziana; Pannone, Giuseppe; Piscazzi, Annamaria; Lamacchia, Olga; Sisinni, Lorenza; Spagnoletti, Girolamo; Toti, Paolo; Santoro, Angela; Storto, Giovanni; Bufo, Pantaleo; Cignarelli, Mauro; Esposito, Franca; Landriscina, Matteo

    2016-09-01

    Tumor necrosis factor receptor-associated protein 1 (TRAP1) is a heat shock protein 90 (HSP90) molecular chaperone upregulated in several human malignancies and involved in protection from apoptosis and drug resistance, cell cycle progression, cell metabolism and quality control of specific client proteins. TRAP1 role in thyroid carcinoma (TC), still unaddressed at present, was investigated by analyzing its expression in a cohort of 86 human TCs and evaluating its involvement in cancer cell survival and proliferation in vitro Indeed, TRAP1 levels progressively increased from normal peritumoral thyroid gland, to papillary TCs (PTCs), follicular variants of PTCs (FV-PTCs) and poorly differentiated TCs (PDTCs). By contrast, anaplastic thyroid tumors exhibited a dual pattern, the majority being characterized by high TRAP1 levels, while a small subgroup completely negative. Consistently with a potential involvement of TRAP1 in thyroid carcinogenesis, TRAP1 silencing resulted in increased sensitivity to paclitaxel-induced apoptosis, inhibition of cell cycle progression and attenuation of ERK signaling. Noteworthy, the inhibition of TRAP1 ATPase activity by pharmacological agents resulted in attenuation of cell proliferation, inhibition of ERK signaling and reversion of drug resistance. These data suggest that TRAP1 inhibition may be regarded as potential strategy to target specific features of human TCs, i.e., cell proliferation and resistance to apoptosis. PMID:27422900

  1. Signal transduction and metabolic changes during tumor cell apoptosis following phthalocyanine-sensitized photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Oleinick, Nancy L.; Agarwal, Munna L.; Berger, Nathan A.; Cheng, Ming-Feng; Chatterjee, Satadel; He, Jin; Kenney, Malcolm E.; Larkin, Hedy E.; Mukhter, Hasan; Rihter, Boris D.; Zaidi, Syed I. A.

    1993-06-01

    Mechanisms of cell death have been explored in cells and tumors treated with photodynamic therapy (PDT). Photosensitizers used for these studies were Photofrin, tetrasulfonated and nonsulfonated aluminum phthalocyanine, and a new silicon phthalocyanine [SiPc(OH)OSi(CH3)2(CH2)3N(CH3)2], referred to as PcIV. In mouse lymphoma L5178Y cells, a dose of PDT sensitized by PcIV which causes a 90% loss of cell survival induces apoptosis (programmed cell death) over a several-hour time course, beginning within 10 minutes of irradiation. Apoptosis is a metabolic process initiated by PDT-induced damage to membranes and triggered by the activation of phospholipases A2 and C and the release of Ca++ from intracellular stores. An endogenous endonuclease is activated and cleaves nuclear DNA in the internucleosomal region of chromatin. Subsequent metabolic events now appear to cause the loss of cellular NAD and ATP, the former a result of the activation of a second nuclear enzyme, poly(ADP-ribose) polymerase, by the endonucleolytically generated DNA strand breaks. Loss of ATP follows upon the loss of NAD needed for energy metabolism. Although the induction of apoptosis is efficiently produced by direct PDT damage to L5178Y cells, we now find that apoptosis is also produced by treatment of certain other lymphoid-derived cells and cells of epithelial origin. Under the limited set of conditions tested, there was no evidence for PDT-induced apoptosis in a fibroblast cell line, in mouse fibrosarcoma RIF-1 and L929 cells, in human adenocarcinoma A549 cells, or in human squamous cell carcinoma cells in culture. The evidence suggests that apoptosis, a form of metabolic cell death, is an important mechanism of tumor ablation in PDT-treated tumors, and that the induction of apoptosis may involve the interaction of direct PDT damage to malignant cells with factors produced by PDT action on vascular and other host cells.

  2. Fast apoptosis and erythroid differentiation induced by imatinib mesylate in JURL-MK1 cells.

    PubMed

    Kuzelová, Katerina; Grebenová, Dana; Marinov, Iuri; Hrkal, Zbynek

    2005-05-15

    We compare the effects of Imatinib mesylate (Glivec) on chronic myeloid leukemia derived cell lines K562 and JURL-MK1. In both cell lines, the cell cycle arrests in G(1)/G(0) phase within 24 h after the addition of 1 microM Imatinib. This is followed by a decrease of Ki-67 expression and the induction of apoptosis. In JURL-MK1 cells, the apoptosis is faster in comparison with K562 cells: the caspase-3 activity reaches the peak value (20 to 30 fold of the control) after about 40 h and the apoptosis proceeds to its culmination point, the DNA fragmentation, within 48 h following 1 microM Imatinib addition. Unlike K562 cells, JURL-MK1 cells possess a probably functional p53 protein inducible by TPA (tetradecanoyl phorbol acetate) or UV-B irradiation. However, no increase in p53 expression was observed in Imatinib-treated JURL-MK1 cells indicating that the difference in the apoptosis rate between the two cell lines is not due to the lack of p53 in K562 cells. Imatinib also triggers erythroid differentiation both in JURL-MK1 and K562 cells. Glycophorin A expression occurred simultaneously with the apoptosis, even at the single cell level. In K562 cells, but not in JURL-MK1 cells, the differentiation process involved increased hemoglobin synthesis. However, during spontaneous evolution of JURL-MK1 cells in culture, the effects produced by Imatinib progressively changed from the fast apoptosis to the more complete erythroid differentiation. We suggest that the apoptosis and the erythroid differentiation are parallel effects of Imatinib and their relative contributions, kinetics and completeness are related to the differentiation stage of the treated cells. PMID:15770664

  3. TAT-apoptin is efficiently delivered and induces apoptosis in cancer cells.

    PubMed

    Guelen, Lars; Paterson, Hugh; Gäken, Joop; Meyers, Michelle; Farzaneh, Farzin; Tavassoli, Mahvash

    2004-02-01

    Apoptin has been described to induce apoptosis in various human cancer cell lines, but not in normal cells, thus making it an interesting candidate for the development of novel therapeutic strategies. Apoptin was generated and cloned into several mammalian expression vectors. Transfection or microinjection of apoptin cDNA resulted in its expression, initially in the cytoplasm with a filamentous pattern. Subsequently, apoptin entered the nucleus and efficiently induced apoptosis in several cancer cell lines. Nuclear localization was shown to be required for induction of apoptosis. Apoptin expression level was found to be an important determinant of the efficiency of induction of apoptosis. Surprisingly, expression of apoptin or GFP-apoptin cDNA induced apoptosis in some normal cells. When fused to the HIV-TAT protein transduction domain and delivered as a protein, TAT-apoptin was transduced efficiently (>90%) into normal and tumour cells. However, TAT-apoptin remained in the cytoplasm and did not kill normal 6689 and 1BR3 fibroblasts. In contrast TAT-apoptin migrated from the cytoplasm to the nucleus of Saos-2 and HSC-3 cancer cells resulting in apoptosis after 24 h. This study shows that apoptin is a powerful apoptosis-inducing protein with a potential for cancer therapy. PMID:14691460

  4. Model for Osteosarcoma-9 as a potent factor in cell survival and resistance to apoptosis

    NASA Astrophysics Data System (ADS)

    Vourvouhaki, Ekaterini; Carvalho, Carla; Aguiar, Paulo

    2007-07-01

    In this paper we use a simple model to explore the function of the gene Osteosarcoma-9 (OS-9). We are particularly interested in understanding the role of this gene as a potent anti-apoptotic factor. The theoretical description is constrained by experimental data from induction of apoptosis in cells where OS-9 is overexpressed. The data available suggest that OS-9 promotes cell viability and confers resistance to apoptosis, potentially implicating OS-9 in the survival of cancer cells. Three different apoptosis-inducing mechanisms were tested and are modeled here. A more complex and realistic model is also discussed.

  5. Both necrosis and apoptosis contribute to HIV-1-induced killing of CD4 cells

    NASA Technical Reports Server (NTRS)

    Plymale, D. R.; Tang, D. S.; Comardelle, A. M.; Fermin, C. D.; Lewis, D. E.; Garry, R. F.

    1999-01-01

    BACKGROUND: Data currently available on HIV-1-induced cytopathology is unclear regarding the mechanism of cell killing. OBJECTIVE: To clarify the extent to which apoptosis or necrosis is involved in HIV-1-induced cell death in view of conflicting existing data. METHODS: T lymphoblastoid cells or peripheral blood mononuclear cells were infected by various strains of HIV-1 and the numbers of apoptotic or necrotic cells were quantified at various times after infection using video-image analysis techniques; the results were compared with the amount of fragmented DNA using a quantitative method. Measurement of mitochondrial transmembrane potential (deltapsi(m)) and intracellular calcium concentrations [Ca2+]i was performed with fluorescent probes and fluorescence concentration analysis (FCA). RESULTS: Although lymphoblastoid and monocytoid cells acutely infected by HIV-1 had increased levels of fragmented DNA, a marker of apoptotic cell death, few (<12%) had condensed chromatin and fragmented nuclei, the morphological features of apoptosis. The predominant alterations in acutely infected cells were distended endoplasmic reticulum and abnormal mitochondria; these ultrastructural changes are consistent with necrosis, although some infected cells simultaneously displayed features of both necrosis and apoptosis. Viability of cells persistently infected by HIV-1 was only minimally reduced from that of uninfected cells. This reduction was accounted for by an increased propensity of the persistently infected cells to die by apoptosis. Alterations in [Ca2+]i and deltapsi(m) occurred in both acutely and persistently infected cells. CONCLUSION: Both necrosis and apoptosis contribute to HIV-1-induced killing of CD4 cells.

  6. Bim contributes to phenethyl isothiocyanate-induced apoptosis in breast cancer cells.

    PubMed

    Hahm, Eun-Ryeong; Singh, Shivendra V

    2012-06-01

    Phenethyl isothiocyanate (PEITC) is a highly promising cancer chemopreventive constituent of cruciferous vegetables (e.g., watercress) with in vivo efficacy in experimental rodent cancer models. Research thus far implicates apoptosis induction in cancer chemopreventive response to PEITC, but the mechanism of proapoptotic effect is not fully understood. The present study demonstrates that p53 upregulated modulator of apoptosis (PUMA)-independent apoptosis by PEITC is mediated by B-cell lymphoma 2 interacting mediator of cell death (Bim). Exposure of a cell line (BRI-JM04) derived from spontaneously developing mammary tumor of a MMTV-neu transgenic mouse to pharmacological concentrations of PEITC resulted in decreased cell viability coupled with apoptosis induction, characterized by release of histone-associated DNA fragments into the cytosol and cleavage of poly-(ADP-ribose)-polymerase and procaspase-3. The PEITC-induced apoptosis in BRI-JM04 cells was associated with up-regulation of Bak, PUMA, and Bim (long and short forms of Bim), increased S65 phosphorylation of BimEL (extra-long form), and down-regulation of Bcl-xL and Bcl-2. On the other hand, a non-tumorigenic human mammary epithelial cell line (MCF-10A) was significantly more resistant to PEITC-induced apoptosis compared with BRI-JM04 despite induction of Bax and PUMA due to concomitant overexpression of anti-apoptotic proteins, including Bcl-xL, Bcl-2, and Mcl-1. Wild-type HCT-116 cells and its isogenic PUMA knockout variant exhibited comparable sensitivity to PEITC-induced apoptosis. On the other hand, small interfering RNA knockdown of Bim protein imparted partial but statistically significant protection against PEITC-induced apoptosis in BRI-JM04, MCF-7, and MDA-MB-231 cells. In conclusion, the present study provides novel insight into the mechanism of PEITC-induced apoptosis involving Bim. PMID:21739479

  7. Resistance to ursolic acid-induced apoptosis through involvement of melanogenesis and COX-2/PGE2 pathways in human M4Beu melanoma cancer cells.

    PubMed

    Hassan, Lama; Pinon, Aline; Limami, Youness; Seeman, Josiane; Fidanzi-Dugas, Chloe; Martin, Frederique; Badran, Bassam; Simon, Alain; Liagre, Bertrand

    2016-07-01

    Melanoma is one of the most aggressive forms of cancer with a continuously growing incidence worldwide and is usually resistant to chemotherapy agents, which is due in part to a strong resistance to apoptosis. Previously, we had showed that B16-F0 murine melanoma cells undergoing apoptosis are able to delay their own death induced by ursolic acid (UA), a natural pentacyclic triterpenoid compound. We had demonstrated that tyrosinase and TRP-1 up-regulation in apoptotic cells and the subsequent production of melanin were implicated in an apoptosis resistance mechanism. Several resistance mechanisms to apoptosis have been characterized in melanoma such as hyperactivation of DNA repair mechanisms, drug efflux systems, and reinforcement of survival signals (PI3K/Akt, NF-κB and Raf/MAPK pathways). Otherwise, other mechanisms of apoptosis resistance involving different proteins, such as cyclooxygenase-2 (COX-2), have been described in many cancer types. By using a strategy of specific inhibition of each ways, we suggested that there was an interaction between melanogenesis and COX-2/PGE2 pathway. This was characterized by analyzing the COX-2 expression and activity, the expression of tyrosinase and melanin production. Furthermore, we showed that anti-proliferative and proapoptotic effects of UA were mediated through modulation of multiple signaling pathways including Akt and ERK-1/2 proteins. Our study not only uncovers underlying molecular mechanisms of UA action in human melanoma cancer cells but also suggest its great potential as an adjuvant in treatment and cancer prevention. PMID:27262506

  8. Rhizoma Paridis Saponins Induces Cell Cycle Arrest and Apoptosis in Non-Small Cell Lung Carcinoma A549 Cells

    PubMed Central

    Zhang, Jue; Yang, Yixi; Lei, Lei; Tian, Mengliang

    2015-01-01

    Background As a traditional Chinese medicine herb, Chonglou (Paris polyphylla var. chinensis) has been used as anticancer medicine in China in recent decades, as it can induce cell cycle arrest and apoptosis in numerous cancer cells. The saponins extract from the rhizoma of Chonglou [Rhizoma Paridis saponins (RPS)] is known as the main active component for anticancer treatment. However, the molecular mechanism of the anticancer effect of RPS is unknown. Material/Methods The present study evaluated the effect of RPS in non-small-cell lung cancer (NSCLC) A549 cells using the 3-(4,5-dimethylthiazol-2-yl) -2,5-diphenyl tetrazolium bromide (MTT) assay and flow cytometry. Subsequently, the expression of several genes associated with cell cycle and apoptosis were detected by reverse transcription-quantitative polymerase chain reaction (qRT-PCR) and Western blotting. Results RPS was revealed to inhibit cell growth, causing a number of cells to accumulate in the G 1 phase of the cell cycle, leading to apoptosis. In addition, the effect was dose-dependent. Moreover, the results of qRT-PCR and Western blotting showed that p53 and cyclin-dependent kinase 2 (CDK2) were significantly downregulated, and that BCL2, BAX, and p21 were upregulated, by RPS treatment. Conclusions We speculated that the RPS could act on a pathway, including p53, p21, BCL2, BAX, and CDK2, and results in G1 cell cycle arrest and apoptosis in NSCLC cells. PMID:26311066

  9. PU.1 induces apoptosis in myeloma cells through direct transactivation of TRAIL

    PubMed Central

    Ueno, S; Tatetsu, H; Hata, H; Iino, T; Niiro, H; Akashi, K; Tenen, DG.; Mitsuya, H; Okuno, Y

    2010-01-01

    We previously reported that PU.1 was down-regulated in myeloma cell lines and myeloma cells in a subset of myeloma patients, and that conditional PU.1 expression in PU.1-negative myeloma cell lines, U266 and KMS12PE, induced growth arrest and apoptosis. To elucidate the molecular mechanisms of the growth arrest and apoptosis, we performed DNA microarray analyses to compare the difference in gene expression before and after PU.1 induction in U266 cells. Among cell cycle-related genes, cyclin A2, cyclin B1, CDK2 and CDK4 were down-regulated and p21 was up-regulated, while among apoptosis-related genes, TRAIL was found highly up-regulated. When TRAIL was knocked down by siRNAs, apoptosis of PU-1-expressing cells was inhibited, suggesting that TRAIL plays a critical role in PU.1-induced apoptosis in both U266 and KMS12PE myeloma cells. In both U266 and KMS12PE cells expressing PU.1, PU.1 directly bound to a region 30 bp downstream of the transcription start site of the TRAIL gene. Up-regulation of PU.1 induced transactivation of the TRAIL promoter in reporter assays, and disruption of the PU.1-binding site in the TRAIL promoter eliminated this transactivation. Therefore, we conclude that PU.1 is capable of inducing apoptosis in certain myeloma cells by direct transactivation of TRAIL. PMID:19749795

  10. Metformin promotes autophagy and apoptosis in esophageal squamous cell carcinoma by downregulating Stat3 signaling

    PubMed Central

    Feng, Y; Ke, C; Tang, Q; Dong, H; Zheng, X; Lin, W; Ke, J; Huang, J; Yeung, S-CJ; Zhang, H

    2014-01-01

    The antidiabetic drug metformin exerts chemopreventive and antineoplastic effects in many types of malignancies. However, the mechanisms responsible for metformin actions appear diverse and may differ in different types of cancer. Understanding the molecular and cellular mechanisms specific for different cancers is important to optimize strategy for metformin treatment in different cancer types. Here, we investigate the in vitro and in vivo effects of metformin on esophageal squamous cell carcinoma (ESCC) cells. Metformin selectively inhibited cell growth in ESCC tumor cells but not immortalized noncancerous esophageal epithelial cells. In addition to apoptosis, metformin triggered autophagy. Pharmacological or genetic inhibition of autophagy sensitized ESCC cells to metformin-induced apoptotic cell death. Mechanistically, signal transducer and activator of transcription 3 (Stat3) and its downstream target Bcl-2 was inactivated by metformin treatment. Accordingly, small interfering RNA (siRNA)-mediated Stat3 knockdown enhanced metformin-induced autophagy and apoptosis, and concomitantly enhanced the inhibitory effect of metformin on cell viability. Similarly, the Bcl-2 proto-oncogene, an inhibitor of both apoptosis and autophagy, was repressed by metformin. Ectopic expression of Bcl-2 protected cells from metformin-mediated autophagy and apoptosis. In vivo, metformin downregulated Stat3 activity and Bcl-2 expression, induced apoptosis and autophagy, and inhibited tumor growth. Together, inactivation of Stat3-Bcl-2 pathway contributes to metformin-induced growth inhibition of ESCC by facilitating crosstalk between apoptosis and autophagy. PMID:24577086

  11. Relationship between Eimeria tenella development and host cell apoptosis in chickens.

    PubMed

    Zhang, Yan; Zheng, Ming-xue; Xu, Zhi-yong; Xu, Huan-cheng; Cui, Xiao-zhen; Yang, Sha-sha; Zhao, Wen-long; Li, Shan; Lv, Qiang-hua; Bai, Rui

    2015-12-01

    Coccidiosis causes considerable economic losses in the poultry industry. At present, the pathology of coccidiosis is preventable with anticoccidials and vaccination, although at considerable cost to the international poultry industry. The purpose of the present study was to elucidate the relationship between Eimeria tenella development and host cell apoptosis in chickens, which provides a theoretical basis for further study of the injury mechanism of E. tenella and the prevention and treatment of coccidiosis. Cecal epithelial cells from chick embryo were used as host cells in vitro. In addition, flow cytometry, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (dUTP) nick-end labeling, and histopathological assays were used to detect the dynamic changes in E. tenella infection rates, DNA injury rates, and apoptosis rates in groups treated with and without the caspase-9 inhibitor Z-LEHD-FMK. Following E. tenella infection, we demonstrated that untreated cells had less apoptosis at 4 h and, inversely, more apoptosis at 24 to 120 h compared with control cells. Furthermore, after the application of Z-LEHD-FMK, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assays, and translation of phosphatidyl serines to the host cell plasma membrane surface, the treated group chick embryo cecal epithelial cells exhibited decreased apoptosis and DNA injuries (P<0.01) at 24 to 120 h. However, light microscopy showed that E. tenella infection rates of treated cells were higher (P<0.01) than untreated cells during the whole experimental period. Together, these observations suggest that E. tenella can protect host cells from apoptosis at early stages of development but can promote apoptosis during the middle to late stages. In addition, the inhibition of host cell apoptosis can be beneficial to the intracellular growth and development of E. tenella. PMID:26467006

  12. Farnesyltransferase inhibitor R115777 inhibits cell growth and induces apoptosis in mantle cell lymphoma

    PubMed Central

    Rolland, Delphine; Camara-Clayette, Valérie; Barbarat, Aurélie; Salles, Gilles; Coiffier, Bertrand; Ribrag, Vincent; Thieblemont, Catherine

    2008-01-01

    The cytotoxic activity of the farnesyltranseferase inhibitor R115777 was evaluated in cell lines representative of mantle cell lymphoma (MCL). Cell growth, proliferation, and apoptosis were analyzed in four human MCL cell lines (Granta, NCEB, REC, and UPN1) in presence of R115777, alone or in combination with vincristin, doxorubicin, bortezomib, cisplatin and cytarabine. Inhibition of farnesylation was determined by the appearance of prelamin A. The antitumor activity of R115777, administered p.o. at 100, 250 and 500mg/kg, was determined in vivo in nude mice xenografted with UPN1 cells. R115777 inhibited the growth of MCL cell lines in vitro with inhibitory concentrations ranging between 2 and 15nM. A fifty percent decrease of cell viability was observed at concentrations comprised between 0.08 and 17μM. Apoptosis, evaluated by annexin V and activated caspase 3 staining, was induced in all cell lines, in 40 to 71% of the cells depending on the cell lines. In addition, R115777 significantly increased the cytotoxic effect of vincristine, doxorubicin, bortezomib, cisplatin and cytarabine (p=0.001, p=0.016, p=0.006, p=0.014 and p=0.007 respectively). Exposure of MCL cell lines to R115777 during 72 hours resulted in inhibition of protein farnesylation. R115777 administered p.o. twice daily for 8 consecutive days to mice bearing established s.c. UPN1 xenograft displayed cytostatic activity at the 500 mg/kg dosage. We have demonstrated that inhibition of farnesyltransferase by R115777 was associated with growth inhibition and apoptosis of MCL cell lines in vitro and tumor xenograft stability in vivo. PMID:17639395

  13. Digital control circuitry of cancer cell and its apoptosis.

    PubMed

    Ardito Marretta, R M; Barbaraci, G

    2009-09-01

    This study, through a typical aerospace systems architecture, suggests an engineering design of a human cancer cell circuitry in which a digital optimal control matrix is assigned to repair the DNA damage level and/or to trigger its apoptosis. Here, the conceived machinery is proposed taking into account the state of the art in cancer investigation. However, it could be further generalized. The most recent studies on cancer pathologies give a predominant role to the oncosuppressor protein p53 and its antagonist, the oncogene Mdm2. Experimental and theoretical approaches are in agreement in deducing a "digital" response of the p53 when genomic integrity is damaged. Once DNA damage is present, the mutual influence of p53 and its antagonist, the Mdm2 oncogene, is closed in a feedback loop. In this work, starting from these current results, a novel molecular mechanism is proposed, based on a digital optimal control law, whereby p53 and Mdm2 proteins activities can be represented by appropriate circuitry and governed by the optimal control law of digital systems. This procedure obtains a real-time sequence evaluation of protein oscillations and an unexpected and relevant acceleration in the DNA repairing when suitable digital control matrix is implemented. Those effects suggest interesting perspectives for future scientific investigations. First of all, the proposed digital circuitry, receiving the p53 signal from a damaged cell, is able to repair the current level of genomic alteration. Moreover, the cell fate is newly conceived and bound by the modified pulsing mechanism of p53. PMID:19670827

  14. Parthenolide induces apoptosis via TNFRSF10B and PMAIP1 pathways in human lung cancer cells

    PubMed Central

    2014-01-01

    Background Parthenolide (PTL) is a sesquiterpene lactone which can induce apoptosis in cancer cells and eradicate cancer stem cells such as leukemia stem cells, prostate tumor-initiating cells and so on. However, the mechanism remains largely unclear. Methods Lung cancer cells were treated with parthenolide and the cell lysates were prepared to detect the given proteins by Western Blot analysis, and the cell survival was assayed by SRB and MTT assay. Cell cycle was evaluated by DNA flow cytometry analysis. TNFRSF10B, PMAIP1, ATF4 and DDIT3 genes were knocked down by siRNA technique. Apoptosis was evaluated by using Annexin V-FITC/PI staining and flow cytometry analysis. Results Parthenolide (PTL) induces apoptosis and cell cycle arrest in human lung cancer cells. Moreover, PTL treatment in NSCLC cells increases expression of TNFRSF10B/DR5 and PMAIP1/NOXA. Silencing of TNFRSF10B or PMAIP1 or overexpression of CFLAR /c-FLIP (long form) could protect cells from PTL-induced apoptosis. Furthermore, PTL could increase the levels of endoplasmic reticulum stress hallmarks such as ERN1, HSPA5, p-EIF2A, ATF4 and DDIT3. Knockdown of ATF4 and DDIT3 abrogated PTL-induced apoptosis, which suggested that PTL induced apoptosis in NSCLC cells through activation of endoplasmic reticulum stress pathway. More importantly, we found that ATF4, DDIT3, TNFRSF10B and PMAIP1 were up-regulated more intensively, while CFLAR and MCL1 were down-regulated more dramatically by PTL in A549/shCDH1 cells than that in control cells, suggesting that PTL preferred to kill cancer stem cell-like cells by activating more intensive ER stress response in cancer stem cell-like cells. Conclusion We showed that parthenolide not only triggered extrinsic apoptosis by up-regulating TNFRSF10B and down-regulating CFLAR, but also induced intrinsic apoptosis through increasing the expression of PMAIP1 and decreasing the level of MCL1 in NSCLC cells. In addition, parthenolide triggered stronger ER stress response in

  15. Apoptosis induction by aluminum phthalocyanine tetrasulfonate-based sonodynamic therapy in HL-60 cells

    NASA Astrophysics Data System (ADS)

    Iwase, Yumiko; Yumita, Nagahiko; Nishi, Koji; Kuwahara, Hiroyuki; Fukai, Toshio; Ikeda, Toshihiko; Chen, Fu-shih; Momose, Yasunori; Umemura, Shin-ichiro

    2015-07-01

    The present study aims to investigate sonodynamically-induced apoptosis using the phthalocyanine, chloroaluminum phthalocyanine tetrasulfonate (AlPcTS). HL-60 cells were exposed to ultrasound for up to 3 min in the absence and presence of AlPcTS. Apoptosis was analyzed by cell morphology, DNA fragmentation, and caspase-3 activity. Electron spin resonance was used to measure reactive oxygen species. The number of apoptotic cells showing membrane blebbing and cell shrinkage after combined treatment (ultrasound and AlPcTS) was significantly higher than following other treatments, including ultrasound alone and AlPcTS alone. Furthermore, DNA ladder formation, caspase-3 activation and enhanced nitroxide generation were observed in cells treated with ultrasound and AlPcTS. Sonodynamically induced apoptosis, caspase-3 activation, and nitroxide generation were significantly suppressed by histidine. The significant reduction by histidine indicated that ultrasonically generated reactive oxygen species, such as singlet oxygen, is an important mediator of sonodynamically-induced apoptosis.

  16. Phloroglucinol induces apoptosis via apoptotic signaling pathways in HT-29 colon cancer cells

    PubMed Central

    KANG, MI-HYE; KIM, IN-HYE; NAM, TAEK-JEO NG

    2014-01-01

    Phloroglucinol is a polyphenolic compound that is used to treat and prevent several human diseases, as it exerts beneficial biological activities, including anti-oxidant, anti-inflammatory and anticancer properties. The aim of the present study was to investigate the effects of phloroglucinol on apoptotic signaling pathways in HT-29 colon cancer cells. The results indicated that phloroglucinol suppressed cell viability and induced apoptosis in HT-29 cells in a concentration-dependent manner. Phloroglucinol treatment of HT-29 cells resulted in characteristic apoptosis-related changes: altered Bcl-2 family proteins, cytochrome c release, and activation of caspase-3 and caspase-8. This study also showed that proteins involved in apoptosis were stimulated by treatment with phloroglucinol. These findings demonstrated that phloroglucinol exerts anticancer activity in HT-29 colon cancer cells through induction of apoptosis. PMID:25070748

  17. Deficiency in glutamine but not glucose induces MYC-dependent apoptosis in human cells

    PubMed Central

    Yuneva, Mariia; Zamboni, Nicola; Oefner, Peter; Sachidanandam, Ravi; Lazebnik, Yuri

    2007-01-01

    The idea that conversion of glucose to ATP is an attractive target for cancer therapy has been supported in part by the observation that glucose deprivation induces apoptosis in rodent cells transduced with the proto-oncogene MYC, but not in the parental line. Here, we found that depletion of glucose killed normal human cells irrespective of induced MYC activity and by a mechanism different from apoptosis. However, depletion of glutamine, another major nutrient consumed by cancer cells, induced apoptosis depending on MYC activity. This apoptosis was preceded by depletion of the Krebs cycle intermediates, was prevented by two Krebs cycle substrates, but was unrelated to ATP synthesis or several other reported consequences of glutamine starvation. Our results suggest that the fate of normal human cells should be considered in evaluating nutrient deprivation as a strategy for cancer therapy, and that understanding how glutamine metabolism is linked to cell viability might provide new approaches for treatment of cancer. PMID:17606868

  18. Ethanol Mediates Cell Cycle Arrest and Apoptosis in SK-N-SH Neuroblastoma Cells

    PubMed Central

    Lee, Maria; Song, Byoung-Joon; Kwon, Yongil

    2014-01-01

    Background: The mechanisms of cell or organ damage by chronic alcohol consumption are still poorly understood. The present study aimed to investigate the role of the mitogen-activated protein kinases during ethanol-induced damage to SK-N-SH neuroblastoma cells. Methods: Cells were treated with ethanol and subsequently analyzed for cell morphology, viability, and DNA fragmentation. Immunoblot analysis was performed to assess various proteins levels associated with cell cycle arrest and apoptosis after ethanol exposure. Results: Ethanol induced time- and dose-dependent cell death in SK-N-SH cells and increased c-Jun N-terminal protein kinase (JNK) activity in a time- and concentration dependent manner. In contrast, p38 kinase activity increased transiently. After treatment with JNK or p38 kinase inhibitors, ethanol-induced cell death significantly reduced. Ethanol-induced cell death was accompanied by increased cytochrome c release and caspase 3 activity observed at 12 h. In contrast, the level of anti-apoptotic Bcl-2 protein did not change. Ethanol also increased the phosphorylation of p53 and p53 activation was followed by an increase in the p21 tumor suppressor protein accompanied by a gradual decrease in phospho-Rb protein. Conclusion: Our results suggest that ethanol mediates apoptosis of neuroblastoma cells by stimulating p53-related cell cycle arrest mediated through activation of the JNK-related pathway. PMID:25337571

  19. Research on effect of minor bupleurum decoction of proliferation and apoptosis of esophageal cancer cell strain eca-109 cell.

    PubMed

    Li, Xiaofang; Sun, Miaomiao; Zhao, Zhihua; Yang, Jianping; Chen, Kuisheng

    2014-09-01

    The research protocol is MTT (Methyl Thiazolyl Tetrazolium) method, Hoechst33342 staining method and flow cytometry detection to observe the effect of minor bupleurum decoction on proliferation inhibition and apoptosis-inducing of esophageal cancer cell strain Eca-109 cell and its purpose is to discuss the effect. The result of MTT method shows that minor buplerum decoction can obviously inhibit proliferation of esophageal cancer cell strain Eca-109 cell. Apoptosis number of esophageal cancer cell increased with the increase of concentration of tetrandrine by the Hoechst 35528 staining experiment of cancer cell in three different concentrations. Flow cytometry detection result showed that cells in cell cycle G0/G1 of esophageal cancer cell strain Eca-109 cell increased obviously and cell in s period decreased significantly. This research proved that minor bupleurum decoction had anti-tumor effect and can influent proliferation and apoptosis of esophageal cancer cell strain Eca-109 cell. PMID:25262517

  20. Boron neutron capture therapy induces cell cycle arrest and cell apoptosis of glioma stem/progenitor cells in vitro

    PubMed Central

    2013-01-01

    Background Glioma stem cells in the quiescent state are resistant to clinical radiation therapy. An almost inevitable glioma recurrence is due to the persistence of these cells. The high linear energy transfer associated with boron neutron capture therapy (BNCT) could kill quiescent and proliferative cells. Methods The present study aimed to evaluate the effects of BNCT on glioma stem/progenitor cells in vitro. The damage induced by BNCT was assessed using cell cycle progression, apoptotic cell ratio and apoptosis-associated proteins expression. Results The surviving fraction and cell viability of glioma stem/progenitor cells were decreased compared with differentiated glioma cells using the same boronophenylalanine pretreatment and the same dose of neutron flux. BNCT induced cell cycle arrest in the G2/M phase and cell apoptosis via the mitochondrial pathway, with changes in the expression of associated proteins. Conclusions Glioma stem/progenitor cells, which are resistant to current clinical radiotherapy, could be effectively killed by BNCT in vitro via cell cycle arrest and apoptosis using a prolonged neutron irradiation, although radiosensitivity of glioma stem/progenitor cells was decreased compared with differentiated glioma cells when using the same dose of thermal neutron exposure and boronophenylalanine pretreatment. Thus, BNCT could offer an appreciable therapeutic advantage to prevent tumor recurrence, and may become a promising treatment in recurrent glioma. PMID:23915425

  1. Effect of arsenic, cadmium and lead on the induction of apoptosis of normal human mononuclear cells

    PubMed Central

    DE LA FUENTE, H; PORTALES-PÉREZ, D; BARANDA, L; DÍAZ-BARRIGA, F; SAAVEDRA-ALANÍS, V; LAYSECA, E; GONZÁLEZ-AMARO, R

    2002-01-01

    The aim of this work was to investigate the effect of cadmium, lead and arsenic on the apoptosis of human immune cells. Peripheral blood mononuclear cells (MNC) were incubated with increasing concentrations of these metals and then cellular apoptosis was determined by flow cytometry and by DNA electrophoresis. We found that arsenic induced a significant level of apoptosis at 15 μm after 48h of incubation. Cadmium had a similar effect, but at higher concentrations (65 μm). In addition, cadmium exerted a cytotoxic effect on MNC that seemed to be independent of the induction of apoptosis. In contrast, concentrations of lead as high as 500 μm were nontoxic and did not induce a significant degree of apoptosis. Additional experiments showed that arsenic at concentrations as low as 1·0 μm had a significant pro-apoptotic effect when cells were cultured in the presence of this pollutant for more than 72. Non-T cells were more susceptible than T lymphocytes to the effect of arsenic and cadmium. Interestingly, MNC from children chronically exposed to arsenic showed a high basal rate of apoptosis and a diminished in vitro sensibility to this metalloid. Our results indicate that both arsenic and cadmium are able to induce apoptosis of lymphoid cells, and suggest that this phenomenon may contribute to their immunotoxic effect in vivo. PMID:12100024

  2. Inhibition of Granzyme B by PI-9 protects prostate cancer cells from apoptosis

    PubMed Central

    Ray, Manisha; Hostetter, Daniel R.; Loeb, Carly RK; Simko, Jeffry; Craik, Charles S.

    2012-01-01

    Background In order for tumors to grow and proliferate, they must avoid recognition by immune cells and subsequent death by apoptosis. Granzyme B, a protease located in natural killer cells, initiates apoptosis in target cells. Inhibition of Granzyme B by PI-9, its natural inhibitor, can prevent apoptosis. Here we investigate whether PI-9 protects prostate cancer cells from apoptosis. Methods The expression of PI-9 was quantified by qPCR in several prostate cancer cell lines, and Granzyme B activity was tested in each cell line. PI-9 was overexpressed in LNCaP cells, which lack endogenous PI-9. Apoptosis was induced by natural killer cells in LNCaP cells that either contained or lacked PI-9, and the percent cell death in was quantified. Lastly, PI-9 levels were examined by qPCR and immunohistochemistry in prostate tumor tissue. Results Prostate cancer cell lines that expressed PI-9 could inhibit Granzyme B. Overexpression of PI-9 protected LNCaP cells from natural killer cell-mediated apoptosis. Examination of the levels of PI-9 in tissue from prostate tumors showed that PI-9 could be upregulated in low grade tumors and stochastically dysregulated in high grade tumors. Additionally, PI-9 is found consistently in high grade prostatic intraepithelial neoplasia and atrophic lesions. Conclusions These results indicate that overexpression of PI-9 can protect prostate cancer cells from apoptosis, and this effect may occur in human prostate tumors. These findings imply that early prostatic inflammation may trigger this increase in PI-9. This suggests that PI-9 upregulation is needed early in tumor progression, before additional protective mechanisms are in place. PMID:21919028

  3. Tocilizumab inhibits neuronal cell apoptosis and activates STAT3 in cerebral infarction rat model

    PubMed Central

    Wang, Shaojun; Zhou, Jun; Kang, Weijie; Dong, Zhaoni; Wang, Hezuo

    2016-01-01

    Cerebral infarction is a severe hypoxic ischemic necrosis with accelerated neuronal cell apoptosis in the brain. As a monoclonal antibody against interleukin 6, tocilizumab (TCZ) is widely used in immune diseases, whose function in cerebral infarction has not been studied. This study aims to reveal the role of TCZ in regulating neuronal cell apoptosis in cerebral infarction. The cerebral infarction rat model was constructed by middle cerebral artery occlusion and treated with TCZ. Cell apoptosis in hippocampus and cortex of the brain was examined with TUNEL method. Rat neuronal cells cultured in oxygen-glucose deprivation (OGD) conditions and treated with TCZ were used to compare cell viability and apoptosis. Apoptosis-related factors including B-cell lymphoma extra large (Bcl-xL) and Caspase 3, as well as the phosphorylated signal transducer and activator of transcription 3 (p-STAT3) in brain cortex were analyzed from the protein level. Results indicated that TCZ treatment could significantly prevent the promoted cell apoptosis caused by cerebral infarction or OGD (P < 0.05 or P < 0.01). In brain cortex of the rat model, TCZ up-regulated Bcl-xL and down-regulated Caspase 3, consistent with the inhibited cell apoptosis. It also promoted tyrosine 705 phosphorylation of STAT3, which might be the potential regulatory mechanism of TCZ in neuronal cells. This study provided evidence for the protective role of TCZ against neuronal cell apoptosis in cerebral infarction. Based on these fundamental data, TCZ is a promising option for treating cerebral infarction, but further investigations on related mechanisms are still necessary. PMID:26773188

  4. Cell-permeable intrinsic cellular inhibitors of apoptosis protect and rescue intestinal epithelial cells from radiation-induced cell death.

    PubMed

    Matsuzaki-Horibuchi, Shiori; Yasuda, Takeshi; Sakaguchi, Nagako; Yamaguchi, Yoshihiro; Akashi, Makoto

    2015-01-01

    One of the important mechanisms for gastrointestinal (GI) injury following high-dose radiation exposure is apoptosis of epithelial cells. X-linked inhibitor of apoptosis (XIAP) and cellular IAP2 (cIAP2) are intrinsic cellular inhibitors of apoptosis. In order to study the effects of exogenously added IAPs on apoptosis in intestinal epithelial cells, we constructed bacterial expression plasmids containing genes of XIAP (full-length, BIR2 domain and BIR3-RING domain with and without mutations of auto-ubiquitylation sites) and cIAP2 proteins fused to a protein-transduction domain (PTD) derived from HIV-1 Tat protein (TAT) and purified these cell-permeable recombinant proteins. When the TAT-conjugated IAPs were added to rat intestinal epithelial cells IEC6, these proteins were effectively delivered into the cells and inhibited apoptosis, even when added after irradiation. Our results suggest that PTD-mediated delivery of IAPs may have clinical potential, not only for radioprotection but also for rescuing the GI system from radiation injuries. PMID:25359904

  5. AMID Mediates Adenosine-Induced Caspase-Independent HuH-7 Cell Apoptosis

    PubMed Central

    Yang, Dongqin; Yaguchi, Takahiro; Nagata, Tetsu; Gotoh, Akinobu; Dovat, Sinisa; Song, Chunhua; Nishizaki, Tomoyuki

    2011-01-01

    Background/Aims: The mechanism underlying extracellular adenosine-induced caspase-independent apoptosis in HuH-7 human hepatoma cells is not fully understood. The present study investigated the role for apoptosis-inducing factor (AIF)-homologous mitochondrion-associated inducer of death (AMID) in the pathway. Methods: To see the implication of AMID in adenosine-induced HuH-7 cell apoptosis, real-time reverse transcription-polymerase chain reaction (RT-PCR), immunofluorescent cytochemistry, time-laps GFP monitoring, cell cycle analysis, flow cytometry, Western blotting, cell viability assay, and TUNEL staining were carried out. Results: Adenosine upregulated AMID expression in HuH-7 cells, and translocated AMID from the cytosol into the nucleus. Adenosine induced HuH-7 cell apoptosis, and the effect was further enhanced by overexpressing AMID. Adenosine-induced HuH-7 cell apoptosis, alternatively, was inhibited by knocking-down AMID. Conclusion: The results of the present study provide evidence for AMID as a critical factor for adenosine-induced caspase-independent HuH-7 cell apoptosis. PMID:21325820

  6. Noscapine induces mitochondria-mediated apoptosis in human colon cancer cells in vivo and in vitro.

    PubMed

    Yang, Zi-Rong; Liu, Meng; Peng, Xiu-Lan; Lei, Xiao-Fei; Zhang, Ji-Xiang; Dong, Wei-Guo

    2012-05-11

    Noscapine, a phthalide isoquinoline alkaloid derived from opium, has been widely used as a cough suppressant for decades. Noscapine has recently been shown to potentiate the anti-cancer effects of several therapies by inducing apoptosis in various malignant cells without any detectable toxicity in cells or tissues. However, the mechanism by which noscapine induces apoptosis in colon cancer cells remains unclear. The signaling pathways by which noscapine induces apoptosis were investigated in colon cancer cell lines treated with various noscapine concentrations for 72 h, and a dose-dependent inhibition of cell viability was observed. Noscapine effectively inhibited the proliferation of LoVo cells in vitro (IC(50)=75 μM). This cytotoxicity was reflected by cell cycle arrest at G(2)/M and subsequent apoptosis, as indicated by increased chromatin condensation and fragmentation, the upregulation of Bax and cytochrome c (Cyt-c), the downregulation of survivin and Bcl-2, and the activation of caspase-3 and caspase-9. Moreover, in a xenograft tumor model in mice, noscapine injection clearly inhibited tumor growth via the induction of apoptosis, which was demonstrated using a TUNEL assay. These results suggest that noscapine induces apoptosis in colon cancer cells via mitochondrial pathways. Noscapine may be a safe and effective chemotherapeutic agent for the treatment of human colon cancer. PMID:22546556

  7. Asymmetric dimethylarginine (ADMA) treatment induces apoptosis in cultured rat mesangial cells via endoplasmic reticulum stress activation.

    PubMed

    Park, Min-Jung; Oh, Ki-Seok; Nho, Jong-Hyun; Kim, Gye-Yeop; Kim, Dong-Il

    2016-06-01

    Asymmetric dimethylarginine (ADMA), a high risk factor for endothelial dysfunction and cardiovascular disease (CVD), has been reported to promote cellular dysfunction via endoplasmic reticulum (ER) stress activation in various cells. Additionally, increased serum ADMA levels have been observed in incipient kidney diseases. Previously, we reported that activated ER stress is associated with mesangial cell apoptosis, observed mainly in overt nephropathy or chronic kidney disease (CKD). However, the effect of ADMA on mesangial cell apoptosis is unknown. Thus, we investigated the effects of ADMA on mesangial cell apoptosis and ER stress signaling. ADMA treatment increased caspase-3 activity and activated three branches of ER stress signaling (PERK, IRE1, and ATF6) that induce mesangial cell apoptosis. Pharmacological inhibitors of ER stress (inhibitors of PERK, IRE1, and S1P) attenuated ADMA-induced cleavage of caspase-3 and induced a decrease in the mitochondrial membrane potential. Furthermore, these inhibitors diminished the number of apoptotic cells induced by ADMA treatment. Taken together, our results indicated that ADMA treatment induces mesangial cell apoptosis via ER stress signaling. These results suggest that ADMA-induced mesangial cell apoptosis could contribute to the progression of overt nephropathy and CKD. PMID:26992443

  8. Low intensity-pulsed ultrasound induced apoptosis of human hepatocellular carcinoma cells in vitro.

    PubMed

    Shi, Mingfang; Liu, Bangzhong; Liu, Guanghua; Wang, Ping; Yang, Mingzhen; Li, Yun; Zhou, Jian

    2016-01-01

    The present study was conducted to determine whether low intensity-pulsed ultrasound (LIPUS) could induce apoptosis of human hepatocellular carcinoma cells, SMMC-7721, and to define the mechanism of ultrasound-induced apoptosis, in vitro. MTT assay was used to measure cell proliferation. Apoptosis was investigated by multiple methods such as flow cytometry, DNA fragmentation, Ca(2+) mobilizations, pro- and anti-apoptotic protein expression, and light as well as ultramicroscopic morphology. The results provide evidence that LIPUS induced a dose-dependent effect on cell viability and apoptosis of SMMC-7721 cells. Specifically, exposure of cells to >0.5 W/cm(2) intensity significantly increased cell apoptosis, caused shifts in cell cycle phase, and induced structural changes. Ultrasound significantly increased intracellular Ca(2+) concentrations and modulated expression of caspase-3, Bcl-2 and Bax. The findings suggest that this novel technology can be used to induce SMMC-7721 apoptosis via the Ca(2+)/mitochondrial pathway and could potentially be of clinical use for the treatment of hepatocellular carcinoma (SMMC-7721 cell line) and other cancers. PMID:26231998

  9. Low-power laser irradiation inhibits amyloid beta-induced cell apoptosis

    NASA Astrophysics Data System (ADS)

    Zhang, Heng; Wu, Shengnan

    2011-03-01

    The deposition and accumulation of amyloid-β-peptide (Aβ) in the brain are considered a pathological hallmark of Alzheimer's disease(AD). Apoptosis is a contributing pathophysiological mechanism of AD. Low-power laser irradiation (LPLI), a non-damage physical therapy, which has been used clinically for decades of years, is shown to promote cell proliferation and prevent apoptosis. Recently, low-power laser irradiation (LPLI) has been applied to moderate AD. In this study, Rat pheochromocytoma (PC12) cells were treated with amyloid beta 25-35 (Aβ25-35) for induction of apoptosis before LPLI treatment. We measured cell viability with CCK-8 according to the manufacture's protocol, the cell viability assays show that low fluence of LPLI (2 J/cm2 ) could inhibit the cells apoptosis. Then using statistical analysis of proportion of apoptotic cells by flow cytometry based on Annexin V-FITC/PI, the assays also reveal that low fluence of LPLI (2 J/cm2 ) could inhibit the Aβ-induced cell apoptosis. Taken together, we demonstrated that low fluence of LPLI (2 J/cm2 ) could inhibit the Aβ-induced cell apoptosis, these results directly point to a therapeutic strategy for the treatment of AD through LPLI.

  10. A COMPREHENSIVE STUDY ON APOPTOSIS INDUCTION BY AZADIRACHTIN IN Spodoptera frugiperda CULTURED CELL LINE Sf9.

    PubMed

    Shu, Benshui; Wang, Wenxiang; Hu, Qingbo; Huang, Jingfei; Hu, Meiying; Zhong, Guohua

    2015-07-01

    The induction of apoptosis by azadirachtin, a well-known botanical tetranortriterpenoid isolated from the neem tree (Azadirachta indica A. Juss) and other members of the Meliaceae, was investigated in Spodoptera frugiperda cultured cell line (Sf9). Morphological changes in Sf9 cells treated by various concentrations of azadirachtin were observed at different times under light microscopy. Morphological and biochemical analysis indicated that Sf9 cells treated by 1.5 μg/mL azadirachtin showed typical morphological changes, which were indicative of apoptosis and a clear DNA ladder. The flow cytometry analysis showed the apoptosis rate reached a maximum value of 32.66% at 24 h with 1.5 μg/mL azadirachtin in Sf9 cells. The inhibition of Sf9 cell proliferation suggested that the effect of azadirachtin was dose dependent and the EC50 at 48 and 72 h was 2.727 × 10(-6) and 6.348 × 10(-9) μg/mL, respectively. The treatment of azadirachtin in Sf9 cells could significantly increase the activity of Sf caspase-1, but showed no effect on the activity of Topo I, suggesting that the apoptosis induced by azadirachtinin Sf9 cells is through caspase-dependent pathway. These results provided not only a series of morphological, biochemical, and toxicological comprehensive evidences for induction of apoptosis by azadirachtin, but also a reference model for screening insect cell apoptosis inducers from natural compounds. PMID:25828604

  11. THE PROS AND CONS OF APOPTOSIS ASSAYS FOR USE IN THE STUDY OF CELLS, TISSUES AND ORGANS

    EPA Science Inventory

    Abstract
    Programmed cell death or apoptosis occurs in many tissues during normal development and in the normal homeostasis of adult tissues. Apoptosis also plays a significant role in abnormal development and disease. Increased interest in apoptosis and cell death in general...

  12. Apoptosis and modulation of cell cycle control by bile acids in human leukemia T cells.

    PubMed

    Fimognari, Carmela; Lenzi, Monia; Cantelli-Forti, Giorgio; Hrelia, Patrizia

    2009-08-01

    Depending on the nature of chemical structures, different bile acids exhibit distinct biological effects. Their therapeutic efficacy has been widely demonstrated in various liver diseases, suggesting that they might protect hepatocytes against common mechanisms of liver damage. Although it has been shown to prevent apoptotic cell death in certain cell lines, bile acids significantly inhibited cell growth and induced apoptosis in cancer cells. To better understand the pharmacological potential of bile acids in cancer cells, we investigated and compared the effects of deoxycholic acid (DCA), ursodeoxycholic acid (UDCA), and their taurine-derivatives [taurodeoxycholic acid (TDCA) and tauroursodeoxycholic acid (TUDCA), respectively] on the induction of apoptosis and inhibition of cell proliferation of a human T leukemia cell line (Jurkat cells). All the bile acids tested induced a delay in cell cycle progression. Moreover, DCA markedly increased the fraction of apoptotic cells. The effects of TDCA, UDCA, and TUDCA were different from those observed for DCA. Their primary effect was the induction of necrosis. These distinctive features suggest that the hydrophobic properties of DCA play a role in its cytotoxic potential and indicate that it is possible to create new drugs useful for cancer therapy from bile acid derivatives as lead compounds. PMID:19723064

  13. Clinostat rotation induces apoptosis in luteal cells of the pregnant rat

    NASA Technical Reports Server (NTRS)

    Yang, Hyunwon; Bhat, Ganapathy K.; Sridaran, Rajagopala

    2002-01-01

    Recent studies have shown that microgravity induces changes at the cellular level, including apoptosis. However, it is unknown whether microgravity affects luteal cell function. This study was performed to assess whether microgravity conditions generated by clinostat rotation induce apoptosis and affect steroidogenesis by luteal cells. Luteal cells isolated from the corpora lutea of Day 8 pregnant rats were placed in equal numbers in slide flasks (chamber slides). One slide flask was placed in the clinostat and the other served as a stationary control. At 48 h in the clinostat, whereas the levels of progesterone and total cellular protein decreased, the number of shrunken cells increased. To determine whether apoptosis occurred in shrunken cells, Comet and TUNEL assays were performed. At 48 h, the percentage of apoptotic cells in the clinostat increased compared with that in the control. To investigate how the microgravity conditions induce apoptosis, the active mitochondria in luteal cells were detected with JC-1 dye. Cells in the control consisted of many active mitochondria, which were evenly distributed throughout the cell. In contrast, cells in the clinostat displayed fewer active mitochondria, which were distributed either to the outer edge of the cell or around the nucleus. These results suggest that mitochondrial dysfunction induced by clinostat rotation could lead to apoptosis in luteal cells and suppression of progesterone production.

  14. The nonstructural protein NP1 of human bocavirus 1 induces cell cycle arrest and apoptosis in Hela cells

    SciTech Connect

    Sun, Bin; Cai, Yingyue; Li, Yongshu; Li, Jingjing; Liu, Kaiyu; Li, Yi; Yang, Yongbo

    2013-05-25

    Human bocavirus type 1 (HBoV1) is a newly identified pathogen associated with human respiratory tract illnesses. Previous studies demonstrated that proteins of HBoV1 failed to cause cell death, which is considered as a possible common feature of bocaviruses. However, our work showed that the NP1 of HBoV1 induced apoptotic cell death in Hela cells in the absence of viral genome replication and expression of other viral proteins. Mitochondria apoptotic pathway was involved in the NP1-induced apoptosis that was confirmed by apoptotic characteristics including morphological changes, DNA fragmentation and caspase activation. We also demonstrated that the cell cycle of NP1-transfected Hela cells was transiently arrested at G2/M phase followed by rapid appearance of apoptosis and that the N terminal domain of NP1 was critical to its nuclear localization and function in apoptosis induction in Hela cells. These findings might provide alternative information for further study of mechanism of HBoV1 pathogenesis. - Highlights: ► NP1 protein of HBoV1 induced apoptosis in Hela cells was first reported. ► NP1 induced-apoptosis followed the cell cycle arrest at G2/M phase. ► The NP1 induced-apoptosis was mediated by mitochondrion apoptotic pathway. ► N terminal of NP1 was critical for apoptosis induction and nuclear localization.

  15. Effect of vascular endothelial growth factor and interleukin-1beta on apoptosis in endometrial cell cultures from patients with endometriosis and controls.

    PubMed

    Bilotas, Mariela; Meresman, Gabriela; Buquet, Ricardo; Sueldo, Carlos; Barañao, Rosa Inés

    2010-03-01

    The aim of this study was to evaluate the effect of vascular endothelial growth factor (VEGF) and interleukin-1beta (IL-1beta) on apoptosis induced by leuprolide acetate (LA) in endometrial epithelial cell cultures from patients with endometriosis. Primary endometrial epithelial cell cultures were obtained from uterine endometrial biopsies of patients with endometriosis and control women. Endometrial epithelial cells were incubated with LA; a combination of LA and VEGF; a combination of LA and IL-1beta; or in basal conditions. LA was added 3h prior to addition of VEGF and IL-1beta. After stimulation, the percentage of apoptotic cells was evaluated by the acridine orange-ethidium bromide technique and Bax expression was assessed by western blot. Treatment with LA enhanced the percentage of apoptotic cells in endometrial epithelial cells from subjects with endometriosis and control subjects. Addition of either VEGF or IL-1beta after exposure to LA restored the percentage of apoptotic cells to basal levels. Moreover, treatment with LA increased Bax expression in endometrial epithelial cells from patients with endometriosis. This effect was reverted by the addition of either VEGF or IL-1beta. Our results show that VEGF and IL-1beta reduce apoptosis and decrease Bax expression in endometrial epithelial cells from patients with endometriosis. This study suggests that VEGF and IL-1beta may protect endometriotic cells from undergoing apoptosis in addition to exerting their pro-angiogenic role. PMID:20137818

  16. Effect of lycopene isolated from Chlorella marina on proliferation and apoptosis in human prostate cancer cell line PC-3.

    PubMed

    Renju, G L; Muraleedhara Kurup, G; Bandugula, Venkata Reddy

    2014-11-01

    Even though the role of lycopene from tomato (trans form) in controlling prostate cancer was reported, lycopene (cis and trans 60:40) isolated from green algae Chlorella marina was not reported so far. The present study aimed to assess the anti-proliferative and apoptotic effect of lycopene from a new source and to compare the activity with available trans lycopene by using androgen-independent human prostate cancer cell lines. Exposure of PC-3 and DU-145 cell lines to algal lycopene (AL) at a dose of 20 and 50 μM significantly inhibited the growth and colony formation, and the percentage of inhibition was higher than tomatal lycopene (TL)-treated groups. The stability of AL in cell culture medium was high, when compared to TL under standard cell culture conditions. The level of lycopene was not detected in PC-3 cell lines cultured in medium lacking lycopene. Staining cells with acridine orange and ethidium bromide, the PC-3 control cells showed largely non-fragmented intact nucleoid. Stronger apoptosis signal was induced with higher concentrations (50 μM) of algal lycopene. Increased DNA damage was observed in AL- and TL-treated cells which appear as comet during single-cell gel electrophoresis. Flow cytometry results revealed that AL caused PC-3 cells to accumulate in the G0/G1 phase and to undergo apoptosis. The effect was higher in AL groups than TL-treated groups. Algal lycopene showed very significant anti-proliferative and apoptotic effect in human prostate cancer cell lines. Therefore, algal lycopene from C.marina would be recommended for the treatment of prostate cancer. PMID:25073513

  17. Che-1 modulates the decision between cell cycle arrest and apoptosis by its binding to p53

    PubMed Central

    Desantis, A; Bruno, T; Catena, V; De Nicola, F; Goeman, F; Iezzi, S; Sorino, C; Gentileschi, M P; Germoni, S; Monteleone, V; Pellegrino, M; Kann, M; De Meo, P D; Pallocca, M; Höpker, K; Moretti, F; Mattei, E; Reinhardt, H C; Floridi, A; Passananti, C; Benzing, T; Blandino, G; Fanciulli, M

    2015-01-01

    The tumor suppressor p53 is mainly involved in the transcriptional regulation of a large number of growth-arrest- and apoptosis-related genes. However, a clear understanding of which factor/s influences the choice between these two opposing p53-dependent outcomes remains largely elusive. We have previously described that in response to DNA damage, the RNA polymerase II-binding protein Che-1/AATF transcriptionally activates p53. Here, we show that Che-1 binds directly to p53. This interaction essentially occurs in the first hours of DNA damage, whereas it is lost when cells undergo apoptosis in response to posttranscriptional modifications. Moreover, Che-1 sits in a ternary complex with p53 and the oncosuppressor Brca1. Accordingly, our analysis of genome-wide chromatin occupancy by p53 revealed that p53/Che1 interaction results in preferential transactivation of growth arrest p53 target genes over its pro-apoptotic target genes. Notably, exposure of Che-1+/− mice to ionizing radiations resulted in enhanced apoptosis of thymocytes, compared with WT mice. These results confirm Che-1 as an important regulator of p53 activity and suggest Che-1 to be a promising yet attractive drug target for cancer therapy. PMID:25996291

  18. Proteomic analysis of enriched lysosomes at early phase of camptothecin-induced apoptosis in human U-937 cells

    PubMed Central

    Parent, Nicolas; Winstall, Eric; Beauchemin, Myriam; Paquet, Claudie; Poirier, Guy G.; Bertrand, Richard

    2013-01-01

    A lysosomal pathway, characterized by partial rupture or labilization of lysosomal membranes and cathepsin activation, is evoked during camptothecin-induced apoptosis in human cancer cells, including human histiocytic lymphoma U-937 cells. These lysosomal events begin rapidly and simultaneously with mitochondrial permeabilization and caspase activation within 3 h after drug treatment. In this study, comparative and quantitative proteome analyses were performed to identify early changes in lysosomal protein expression/localization from U-937 cells undergoing apoptosis. In 2 independent experiments, among a total of more than 538 proteins putatively identified and quantitated by iTRAQ isobaric labeling and LC-ESI-MS/MS, 18 proteins were found to be upregulated and 9 downregulated in lysosomes purified from early apoptotic compared to control cells. Protein expression was validated by Western blotting on enriched lysosome fractions, and protein localization confirmed by fluorescence confocal microscopy of representative protein candidates, whose functions are associated with lysosomal membrane fluidity and dynamics. These include sterol-4-alpha-carboxylate 3-dehydrogenase (NSDHL), prosaposin (PSAP) and protein kinase C delta (PKC-δ). This comparative proteome analysis provides the basis for novel hypothesis and rationale functional experimentation, where the 3 validated candidate proteins are associated with lysosomal membrane fluidity and dynamics, particularly cholesterol, sphingolipid and glycosphingolipid metabolism. PMID:19393779

  19. Dynamic interaction between 14-3-3zeta and bax during TNF-α-induced apoptosis in living cells

    NASA Astrophysics Data System (ADS)

    Gao, Xuejuan; Xing, Da; Chen, Tongsheng

    2006-09-01

    Bax, a proapoptotic member of the Bcl-2 family, localizes largely in the cytoplasm but redistributes to mitochondria and undergoes oligomerization to induce the release of apoptogenic factors such as cytochrome c in response to apoptotic stimuli. Cytoplasmic protein 14-3-3zeta binds to Bax and, upon apoptotic stimulation, releases Bax by a caspase-independent mechanism. However, the direct interaction of the cytoplasmic 14-3-3zeta and Bax in living cells has not been observed. In present study, to monitor the dynamic interaction between 14-3-3zeta and Bax in living cells in real time during apoptosis induced by tumor necrosis factor (TNF-α), DsRed-14-3-3zeta plasmid is constructed. By cotransfecting DsRed- 14-3-3zeta and GFP-Bax plasmids into human lung adenocarcinoma cells (ASTC-a-1), we observe the dynamic interaction between Bax and 14-3-3zeta using fluorescence resonance energy transfer (FRET) technique on laser scanning confocal microscope. The results show that 14-3-3zeta remains in the cytoplasm but GFP-Bax translocates to mitochondria completely after TNF-α stimulation. These results reveal that 14-3-3zeta binds directly to Bax in healthy cells, and that 14-3-3zeta negatively regulates Bax translocation to mitochondria during TNF-α-induced apoptosis.

  20. Highly pathogenic porcine reproductive and respiratory syndrome virus infection and induction of apoptosis in bone marrow cells of infected piglets.

    PubMed

    Wang, Gang; Li, Li; Yu, Ying; Tu, Yabin; Tong, Jie; Zhang, Chong; Liu, Yonggang; Li, Yuming; Han, Zifeng; Jiang, Chenggang; Wang, Shujie; Zhou, En-Min; He, Xijun; Cai, Xuehui

    2016-06-01

    Highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) has been shown to have a wide range of tissue tropism, and can directly and indirectly induce cellular apoptosis. However, the impact of HP-PRRSV infection on the bone marrow (BM) of piglets remains unclear. In this study, we investigated the BM as a novel site of infection by the HP-PRRSV strain in piglets. HP-PRRSV infected SWC3+SWC8- cells in the BM and induced BM cells to undergo apoptosis. The number of apoptotic cells highlights the striking effects of HP-PRRSV on the central immune organs (BM and thymus) that may enhance the susceptibility of pigs to secondary infections and lead to high mortality. This study is, to the best of our knowledge, the first to report the impact of HP-PRRSV on the BM and implicate the depletion of BM cells during HP-PRRSV infection in the development of immunosuppression in this disease. PMID:26963602

  1. Carnosic acid induces apoptosis associated with mitochondrial dysfunction and Akt inactivation in HepG2 cells.

    PubMed

    Xiang, Qisen; Ma, Yunfang; Dong, Jilin; Shen, Ruiling

    2015-02-01

    Carnosic acid (CA), a phenolic diterpene isolated from rosemary, shows potential benefits in health promotion and disease prevention. In the present study, the cytotoxic and apoptotic-inducing effects of CA on human hepatocellular carcinoma HepG2 cells were investigated. The MTT assay results indicated that CA decreased cell viability in HepG2 cells in a dose-dependent manner. Treatment with CA caused a rapid Caspase-3 activation and subsequently proteolytic cleavage of poly (ADP-ribose) polymerase (PARP), both of which were markers of cells undergoing apoptosis. CA also dissipated mitochondrial membrane potential and decreased the ratio of Bcl-2/Bax protein, which mediated cytosolic translocation of cytochrome c from the mitochondria. Furthermore, CA reduced the phosphorylation of Akt, which was partially inhibited by insulin, an activator of phosphatidylinositol 3-kinase (PI3K)/Akt signalling pathway. In conclusion, our data suggest that the mitochondrial dysfunction and deactivation of Akt may contribute to the apoptosis-inducing effects of CA. PMID:25265205

  2. Mipu1 overexpression protects macrophages from oxLDL-induced foam cell formation and cell apoptosis.

    PubMed

    Qu, Shun-Lin; Fan, Wen-Jing; Zhang, Chi; Guo, Fang; Han, Dan; Pan, Wen-Jun; Li, Wei; Feng, Da-Ming; Jiang, Zhi-Sheng

    2014-12-01

    Mipu1 (myocardial ischemic preconditioning upregulated protein 1) is a novel N-terminal Kruppel-associated box (KRAB)/C2H2 zinc finger superfamily protein, that displays a powerful effect in protecting H9c2 cells from oxidative stress-induced cell apoptosis. The present study aims to investigate the effect of Mipu1 overexpression on oxidized low-density lipoprotein (oxLDL)-induced foam cell formation, cell apoptosis, and its possible mechanisms. New Zealand healthy rabbits were used to establish atherosclerosis model, and serum levels of triglycerides, total cholesterol, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol were detected by an automatic biochemical analyzer. Sudan IV staining was used to detect atherosclerotic lesions. The RAW264.7 macrophage cell line was selected as the experimental material. Oil red O staining, high-performance liquid chromatography, and Dil-labeled lipoprotein were used to detect cholesterol accumulation qualitatively and quantitatively, respectively. Flow cytometry was used to determine cell apoptosis. Real-time quantitative polymerase chain reaction (PCR) was used to detect the mRNA expression of the main proteins that are associated with the transport of cholesterol, such as ABCA1, ABCG1, SR-BI, and CD36. Western blot analysis was used to detect the protein expression of Mipu1. There were atherosclerotic lesions in the high-fat diet group with Sudan IV staining. High-fat diet decreased Mipu1 expression and increased CD36 expression significantly at the 10th week compared with standard-diet rabbits. Mipu1 overexpression decreased oxLDL-induced cholesterol accumulation, oxLDL uptake, cell apoptosis, and cleaved caspase-3. Mipu1 overexpression inhibited the oxLDL-induced CD36 mRNA and protein expression, but it did not significantly inhibit the mRNA expression of ABCA1, ABCG1, and SR-BI. Mipu1 overexpression inhibits oxLDL-induced foam cell formation and cell apoptosis. Mipu1 overexpression reduces the

  3. Observing real-time molecular event dynamics of apoptosis in living cancer cells using nuclear-targeted plasmonically enhanced Raman nanoprobes.

    PubMed

    Kang, Bin; Austin, Lauren A; El-Sayed, Mostafa A

    2014-05-27

    Apoptosis is a biological process that plays important roles in embryogenesis, aging, and various diseases. During the process of apoptosis, cells undergo a series of morphological and molecular events such as blebbing, cell shrinkage, proteolysis, and nuclear DNA fragmentation. Investigating these events on a molecular level is crucial for gaining a more complete understanding of the intricate mechanism of apoptosis; however, the simultaneous direct observation of morphological and molecular events in real-time on a single living cell scale still remains a challenge. Herein, we directly monitored morphological and molecular events during cellular apoptosis in real-time after the treatment of an apoptosis-inducing agent, by utilizing our previously described plasmonically enhanced Rayleigh/Raman spectroscopic technique. Spectroscopic analysis of the DNA/protein composition around the cell nucleus revealed the occurrence and dynamics of three apoptotic molecular events: protein denaturation, proteolysis, and DNA fragmentation. The molecular event dynamics were used to create a temporal profile of apoptotic events in single cells. It is found that the sequence of events occurring in the apoptotic process induced by hydrogen peroxide addition is protein denaturation through disulfide bond breakage as well as DNA fragmentation, followed in time by protein unraveling with hydrophobic amino acid exposure, and finally protein degradation. These results demonstrate the potential of using this time-dependent plasmonically enhanced vibrational imaging technique to study the detailed mechanism of other apoptosis molecular pathways induced by different agents (e.g., anticancer drugs). A note is given in the conclusion discussing the expected large difference between the SERS spectrum of biological molecules in solution and that observed in live cells which are enhanced by the plasmonic field of the aggregated nanoparticles. PMID:24708404

  4. Perfluorooctanesulfonate Mediates Renal Tubular Cell Apoptosis through PPARgamma Inactivation

    PubMed Central

    Chou, Hsiu-Chu; Chang, Chih-Cheng; Lo, Hau-Yin; Juan, Shu-Hui

    2016-01-01

    Perfluorinated chemicals (PFCs) are ubiquitously distributed in the environments including stainless pan-coating, raincoat, fire extinguisher, and semiconductor products. The PPAR family has been shown to contribute to the toxic effects of PFCs in thymus, immune and excretory systems. Herein, we demonstrated that perfluorooctanesulfonate (PFOS) caused cell apoptosis through increasing ratio of Bcl-xS/xL, cytosolic cytochrome C, and caspase 3 activation in renal tubular cells (RTCs). In addition, PFOS increased transcription of inflammatory cytokines (i.e., TNFα, ICAM1, and MCP1) by NFκB activation. Conversely, PFOS reduced the mRNA levels of antioxidative enzymes, such as glutathione peroxidase, catalase, and superoxide dismutase, as a result of reduced PPARγ transactivational activity by using reporter and chromatin immuoprecipitation (ChIP) assays. PFOS reduced the protein interaction between PPARγ and PPARγ coactivator-1 alpha (PGC1α) by PPARγ deacetylation through Sirt1 upregulation, of which the binding of PPARγ and PGC1α to a peroxisome proliferator response element (PPRE) in the promoter regions of these antioxidative enzymes was alleviated in the ChIP assay. Furthermore, Sirt1 also deacetylated p53 and then increased the binding of p53 to Bax, resulting in increased cytosolic cytochrome C. The effect of PPARγ inactivation by PFOS was validated using the PPARγ antagonist GW9662, whereas the adverse effects of PFOS were prevented by PPARγ overexpression and activators, rosiglitozone and L-carnitine, in RTCs. The in vitro finding of protective effect of L-carnitine was substantiated in vivo using Balb/c mice model subjected to PFOS challenge. Altogether, we provide in vivo and in vitro evidence for the protective mechanism of L-carnitine in eliminating PFOS-mediated renal injury, at least partially, through PPARγ activation. PMID:27171144

  5. Perfluorooctanesulfonate Mediates Renal Tubular Cell Apoptosis through PPARgamma Inactivation.

    PubMed

    Wen, Li-Li; Lin, Chien-Yu; Chou, Hsiu-Chu; Chang, Chih-Cheng; Lo, Hau-Yin; Juan, Shu-Hui

    2016-01-01

    Perfluorinated chemicals (PFCs) are ubiquitously distributed in the environments including stainless pan-coating, raincoat, fire extinguisher, and semiconductor products. The PPAR family has been shown to contribute to the toxic effects of PFCs in thymus, immune and excretory systems. Herein, we demonstrated that perfluorooctanesulfonate (PFOS) caused cell apoptosis through increasing ratio of Bcl-xS/xL, cytosolic cytochrome C, and caspase 3 activation in renal tubular cells (RTCs). In addition, PFOS increased transcription of inflammatory cytokines (i.e., TNFα, ICAM1, and MCP1) by NFκB activation. Conversely, PFOS reduced the mRNA levels of antioxidative enzymes, such as glutathione peroxidase, catalase, and superoxide dismutase, as a result of reduced PPARγ transactivational activity by using reporter and chromatin immuoprecipitation (ChIP) assays. PFOS reduced the protein interaction between PPARγ and PPARγ coactivator-1 alpha (PGC1α) by PPARγ deacetylation through Sirt1 upregulation, of which the binding of PPARγ and PGC1α to a peroxisome proliferator response element (PPRE) in the promoter regions of these antioxidative enzymes was alleviated in the ChIP assay. Furthermore, Sirt1 also deacetylated p53 and then increased the binding of p53 to Bax, resulting in increased cytosolic cytochrome C. The effect of PPARγ inactivation by PFOS was validated using the PPARγ antagonist GW9662, whereas the adverse effects of PFOS were prevented by PPARγ overexpression and activators, rosiglitozone and L-carnitine, in RTCs. The in vitro finding of protective effect of L-carnitine was substantiated in vivo using Balb/c mice model subjected to PFOS challenge. Altogether, we provide in vivo and in vitro evidence for the protective mechanism of L-carnitine in eliminating PFOS-mediated renal injury, at least partially, through PPARγ activation. PMID:27171144

  6. Adult-born hippocampal dentate granule cells undergoing maturation modulate learning and memory in the brain

    PubMed Central

    Deng, Wei; Saxe, Michael D.; Gallina, Iryna S.; Gage, Fred H.

    2009-01-01

    Adult-born dentate granule cells (DGCs) contribute to learning and memory, yet it remains unknown when adult-born DGCs become involved in the cognitive processes. During neurogenesis, immature dentate granule cells (DGCs) display distinctive physiological characteristics while undergoing morphological maturation before final integration into the neural circuits. The survival and activity of the adult-born DGCs can be influenced by the experience of the animal during a critical period when newborn DGCs are still immature. To assess the temporal importance of adult neurogenesis, we developed a transgenic mouse model that allowed us to transiently reduce the numbers of adult-born DGCs in a temporally regulatable manner. We found that mice with a reduced population of adult-born DGCs at the immature stage were deficient in forming robust, long-term spatial memory and displayed impaired performance in extinction tasks. These results suggest that immature DGCs that undergo maturation make important contributions to learning and memory. PMID:19864566

  7. Apigenin Induces the Apoptosis and Regulates MAPK Signaling Pathways in Mouse Macrophage ANA-1 Cells

    PubMed Central

    Liao, Yuexia; Shen, Weigan; Kong, Guimei; Lv, Houning; Tao, Wenhua; Bo, Ping

    2014-01-01

    Apigenin is a naturally occurring plant flavonoid that possesses antioxidant, anti-cancer and anti-inflammatory properties. However, there are few reports has been done on the ability of apigenin to induce apoptosis in macrophages. In this study, mouse macrophage ANA-1 cells were incubated with different concentrations of apigenin. The cell viability was determined by an MTT assay. The cell apoptosis were analyzed by flow cytometric analysis. Apoptosis were also analyzed using a TUNEL assay and a DNA ladder. The level of intracellular ROS was detected using a dichlorofluorescein -diacetate probe. The expression levels of apoptosis-related proteins were detected by western blot analysis. The results showed that apigenin decreased the viability of ANA-1 cells and induced apoptosis in a dose- and time-dependent manner. Apigenin increased the level of intracellular ROS, downregulated the expression of Bcl-2 and upregulated the expression of caspase-3 and caspase-8 in ANA-1 cells. Furthermore, apigenin downregulated the expression of phospho-ERK and phospho-JNK, upregulated the expression of phospho-p38 and had no significant effect on the expression of Bax, ERK, JNK and p38. The results suggested that apigenin induced cell apoptosis in mouse macrophage ANA-1 cells may via increasing intracellular ROS, regulating the MAPK pathway, and then inhibiting Bcl-2 expression. PMID:24646936

  8. MiRNA-1469 promotes lung cancer cells apoptosis through targeting STAT5a

    PubMed Central

    Xu, Chengshan; Zhang, Ling; Li, Hengheng; Liu, Zhihua; Duan, Lianning; Lu, Chengrong

    2015-01-01

    MicroRNAs play key roles in cell growth, differentiation, and apoptosis. In this study, we described the regulation and function of miR-1469 in apoptosis of lung cancer cells (A549 and NCI-H1650). Expression analysis verified that miR-1469 expression significantly increased in apoptotic cells. Overexpression of miR-1469 in lung cancer cells increased cell apoptosis induced by etoposide. Additionally, we identified that Stat5a is a downstream target of miR-1469, which can bind directly to the 3’-untranslated region of the Stat5a, subsequently reducing both the mRNA and protein levels of Stat5a. Finally, co-expression of miR-1469 and Stat5a in A549 and NCI-H1650 cells partially abrogated the effect of miR-1469 on cell apoptosis. Our results show that miR-1469 functions as an apoptosis enhancer to regulate lung cancer apoptosis through targeting Stat5a and may become a critical therapeutic target in lung cancer. PMID:26045996

  9. Apoptosis of human gastric carcinoma cells induced by Euphorbia esula latex

    PubMed Central

    Fu, Zhao-Ying; Han, Xiao-Dong; Wang, Ai-Hong; Liu, Xiao-Bin

    2016-01-01

    AIM: To investigate the effect of Euphorbia esula (E. esula) extract in inhibiting proliferation and inducing apoptosis in SGC-7901 cells. METHODS: E. esula extract at different concentrations was used to inhibit proliferation and induce apoptosis of human gastric carcinoma SGC-7901 cells. Inhibition of proliferation was detected with thiazolyl blue assay, and apoptosis was detected with fluorescence microscopy, transmission electron microscopy, and flow cytometry. The mechanisms were studied by measurement of caspase-3 and caspase-8 activities and Bax and Bcl2 mRNA expression. RESULTS: The thiazolyl blue assay showed that SGC-7901 cell viability and proliferation were inhibited significantly by E. esula extract in a time- and concentration-dependent manner. Fluorescence microscopy revealed that the cell nuclei showed the characteristic changes of apoptosis, such as uneven staining and chromatin marginalization. Some key features of apoptosis were also observed under transmission electron microscopy, which included cellular shrinkage and the foaming or bubbling phenomenon. When the cells were analyzed by flow cytometry, a sub-G1 peak could be seen clearly. Spectrophotometric assay of caspase-3 and caspase-8 activities in the treated cells showed an approximately two-fold increase. Reverse transcription polymerase chain reaction showed that Bax mRNA expression was upregulated, while Bcl2 mRNA expression was downregulated. CONCLUSION: E. esula extract inhibited proliferation and induced apoptosis in SGC-7901 cells, in a caspase-dependent manner, involving upregulation of Bax and downregulation of Bcl2. PMID:27053848

  10. Chloride channel protein 2 prevents glutamate-induced apoptosis in retinal ganglion cells

    PubMed Central

    Bi, Miao-Miao; Hong, Sen; Ma, Ling-Jun; Zhou, Hong-Yan; Lu, Jia; Zhao, Jing; Zheng, Ya-Juan

    2016-01-01

    Objective(s): The purpose of this study was to investigate the role of chloride channel protein 2 (ClC-2) in glutamate-induced apoptosis in the retinal ganglion cell line (RGC-5). Materials and Methods: RGC-5 cells were treated with 1 mM glutamate for 24 hr. The expression of ClC-2, Bax, and Bcl-2 was detected by western blot analysis. Cell survival and apoptosis were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometry assays, respectively. Caspase-3 and -9 activities were determined by a colorimetric assay. The roles of ClC-2 in glutamate-induced apoptosis were examined by using ClC-2 complementary deoxyribonucleic acid (cDNA) and small inference ribonucleic acid (RNA) transfection technology. Results: Overexpression of ClC-2 in RGC-5 cells significantly decreased glutamate-induced apoptosis and increased cell viability, whereas silencing of ClC-2 with short hairpin (sh) RNA produced opposite effects. ClC-2 overexpression increased the expression of Bcl-2, decreased the expression of Bax, and decreased caspase-3 and -9 activation in RGC-5 cells treated with glutamate, but silencing of ClC-2 produced opposite effects. Conclusion: Our data suggest that ClC-2 chloride channels might play a protective role in glutamate-induced apoptosis in retinal ganglion cells via the mitochondria-dependent apoptosis pathway.

  11. Depletion of mitochondrial fission factor DRP1 causes increased apoptosis in human colon cancer cells

    SciTech Connect

    Inoue-Yamauchi, Akane; Oda, Hideaki

    2012-04-27

    Highlights: Black-Right-Pointing-Pointer DRP1 is required for mitochondrial fission in colon cancer cells. Black-Right-Pointing-Pointer DRP1 participates in inhibition of colon cancer cell apoptosis. Black-Right-Pointing-Pointer DRP1 can inhibit apoptosis through the regulation of cytochrome c release. -- Abstract: Mitochondria play a critical role in regulation of apoptosis, a form of programmed cell death, by releasing apoptogenic factors including cytochrome c. Growing evidence suggests that dynamic changes in mitochondrial morphology are involved in cellular apoptotic response. However, whether DRP1-mediated mitochondrial fission is required for induction of apoptosis remains speculative. Here, we show that siRNA-mediated DRP1 knockdown promoted accumulation of elongated mitochondria in HCT116 and SW480 human colon cancer cells. Surprisingly, DRP1 down-regulation led to decreased proliferation and increased apoptosis of these cells. A higher rate of cytochrome c release and reductions in mitochondrial membrane potential were also revealed in DRP1-depleted cells. Taken together, our present findings suggest that mitochondrial fission factor DRP1 inhibits colon cancer cell apoptosis through the regulation of cytochrome c release and mitochondrial membrane integrity.

  12. MiRNA-1469 promotes lung cancer cells apoptosis through targeting STAT5a.

    PubMed

    Xu, Chengshan; Zhang, Ling; Li, Hengheng; Liu, Zhihua; Duan, Lianning; Lu, Chengrong

    2015-01-01

    MicroRNAs play key roles in cell growth, differentiation, and apoptosis. In this study, we described the regulation and function of miR-1469 in apoptosis of lung cancer cells (A549 and NCI-H1650). Expression analysis verified that miR-1469 expression significantly increased in apoptotic cells. Overexpression of miR-1469 in lung cancer cells increased cell apoptosis induced by etoposide. Additionally, we identified that Stat5a is a downstream target of miR-1469, which can bind directly to the 3'-untranslated region of the Stat5a, subsequently reducing both the mRNA and protein levels of Stat5a. Finally, co-expression of miR-1469 and Stat5a in A549 and NCI-H1650 cells partially abrogated the effect of miR-1469 on cell apoptosis. Our results show that miR-1469 functions as an apoptosis enhancer to regulate lung cancer apoptosis through targeting Stat5a and may become a critical therapeutic target in lung cancer. PMID:26045996

  13. MDA-7 results in downregulation of AKT concomitant with apoptosis and cell cycle arrest in breast cancer cells

    PubMed Central

    Valero, V; Wingate, H; Chada, S; Liu, Y; Palalon, F; Mills, G; Keyomarsi, K; Hunt, KK

    2013-01-01

    The melanoma differentiation-associated gene-7 (mda-7) is a known mediator of apoptosis in cancer cells but not in normal cells. We hypothesized that MDA-7 interferes with the prosurvival signaling pathways that are commonly altered in cancer cells to induce growth arrest and apoptosis. We also identified the cell signaling pathways that are antagonized by MDA-7 leading to apoptosis. Using an adenoviral expression system, mda-7 was introduced into the breast cancer cell lines SKBr3, MCF-7 and MDA-MB-468, each with a different estrogen receptor (ER) and HER-2 receptor status. Downstream targets of MDA-7 were assessed by reverse phase protein array analysis, western blot analysis and immunofluorescence confocal microscopy. Our results show that MDA-7-induced apoptosis was mediated by caspases in all cell lines tested. However, MDA-7 modulates additional pathways in SKBr3 (HER-2 positive) and MCF-7 (ER positive) cells including downregulation of AKT-GSK3β and upregulation of cyclin-dependent kinase inhibitors in the nucleus. This leads to cell cycle arrest in addition to apoptosis. In conclusion, MDA-7 abrogates tumor-promoting pathways including the activation of caspase-dependent signaling pathways ultimately leading to apoptosis. In addition, depending on the phenotype of the breast cancer cell, MDA-7 modulates cell cycle regulating pathways to mediate cell cycle arrest. PMID:21546925

  14. Gamma Tocopherol and Lovastatin Additively Induced Apoptosis in Human Colorectal Carcinoma Cell Line (HT29)

    PubMed Central

    Zeidooni, Leila; Rezaei, Mohsen; Hashemi Tabar, Mahmood

    2012-01-01

    Background Programmed cell death (apoptosis) is a physiological process needed to remove unwanted or damaged cells. It has been hypothesized that any failure of programmed cell death leads to the development of neoplasm. Identifying new agents which induce apoptosis in tumor cells is of great significance in treatment of neoplasms. Numerous studies suggest that exposure of tumor cells to statins and gamma tocopherol can lead to cell death. Objectives The aim of this study was to evaluate the cell death induced by gamma tocopherol and lovastatin in human colorectal carcinoma cell line (HT29) using flow cytometry. Material and Methods HT29 cells were grown in DMEM medium, exposed to different concentrations of lovastatin (10,20,40,100μM ) and gamma tocopherol (25,50,100,200μM) for 48 and 72 hours, individually and in combination (100μM both, 48 h). Phenotype of apoptosis was determined by means of flow cytometry. Results All Concentrations of lovastatin (10, 20, 40, 100 μM) and gamma tocopherol (25, 50, 100, 200 μM) induced an apoptotic response in HT29 cells. In combination, a significant increase in apoptosis phenotype was also demonstrated (P < 0.05). Conclusions This study showed that lovastatin when combined with gamma tocopherol, could induce apoptosis in HT29 cells more potently than each agent alone, which uncovers the significance of targeting the proliferative signaling in different points of the pathway. PMID:24624174

  15. Lentiviral Delivery of HIV-1 Vpr Protein Induces Apoptosis in Transformed Cells

    NASA Astrophysics Data System (ADS)

    Stewart, Sheila A.; Poon, Betty; Jowett, Jeremy B. M.; Xie, Yiming; Chen, Irvin S. Y.

    1999-10-01

    Most current anticancer therapies act by inducing tumor cell stasis followed by apoptosis. HIV-1 Vpr effectively induces apoptosis of T cells after arrest of cells at a G2/M checkpoint. Here, we investigated whether this property of Vpr could be exploited for use as a potential anticancer agent. As a potentially safer alternative to transfer of genes encoding Vpr, we developed a method to efficiently introduce Vpr protein directly into cells. Vpr packaged into HIV-1 virions lacking a genome induced efficient cell cycle arrest and apoptosis. Introduction of Vpr into tumor cell lines of various tissue origin, including those bearing predisposing mutations in p53, XPA, and hMLH1, induced cell cycle arrest and apoptosis with high efficiency. Significantly, apoptosis mediated by virion-associated Vpr was more effective on rapidly dividing cells compared with slow-growing cells, thus, in concept, providing a potential differential effect between some types of tumor cells and surrounding normal cells. This model system provides a rationale and proof of concept for the development of potential cancer therapeutic agents based on the growth-arresting and apoptotic properties of Vpr.

  16. Methylanthraquinone from Hedyotis diffusa WILLD induces Ca(2+)-mediated apoptosis in human breast cancer cells.

    PubMed

    Liu, Zheng; Liu, Ming; Liu, Miao; Li, Jianchun

    2010-02-01

    Methylanthraquinone from Hedyotis diffusa WILLD exhibited potent anticancer activity in many kinds of cancer cells. However, the exact mechanism and signaling pathway involved in methylanthraquinone-induced apoptosis have not been fully elucidated. Therefore, we explored the mechanisms of methylanthraquinone-mediated apoptosis in MCF-7 human breast cancer cells. When MCF-7 cells were co-incubated with methylanthraquinone, the percentage of apoptotic cell and S phase of cell cycle was markedly increased. In addition, a rise in intracellular calcium levels, phosphorylation of JNK and activation of calpain were found in MCF-7 cells after exposure to methylanthraquinone. With the methylanthraquinone-mediated reduction of mitochondrial membrane potential, cytochrome c was released from mitochondria to cytosol. Moreover, methylanthraquinone strongly induced cleavage of caspase-4, caspase-9 and caspase-7 in MCF-7 cells. These results suggested that methylanthraquinone from Hedyotis diffusa WILLD induced MCF-7 cells apoptosis via Ca(2+)/calpain/caspase-4 pathway. PMID:19686834

  17. Expression of cell cycle and apoptosis regulators in thymus and thymic epithelial tumors.

    PubMed

    Papoudou-Bai, Alexandra; Barbouti, Alexandra; Galani, Vassiliki; Stefanaki, Kalliopi; Rontogianni, Dimitra; Kanavaros, Panagiotis

    2016-05-01

    The human thymus supports the production of self-tolerant T cells with competent and regulatory functions. Various cellular components of the thymic microenvironment such as thymic epithelial cells (TEC) and dendritic cells play essential roles in thymic T cell differentiation. The multiple cellular events occurring during thymic T cell and TEC differentiation involve proteins regulating cell cycle and apoptosis. Dysregulation of the cell cycle and apoptosis networks is involved in the pathogenesis of thymic epithelial tumors (TET) which are divided into two broad categories, thymomas and thymic carcinomas. The present review focuses on the usefulness of the analysis of the expression patterns of major cell cycle and apoptosis regulators in order to gain insight in the histophysiology of thymus and the histopathology, the clinical behavior and the biology of TET. PMID:25794494

  18. Diosgenin induces G2/M cell cycle arrest and apoptosis in human hepatocellular carcinoma cells.

    PubMed

    Li, Yongjian; Wang, Xiaorong; Cheng, Silu; Du, Juan; Deng, Zhengting; Zhang, Yani; Liu, Qun; Gao, Jingdong; Cheng, Binbin; Ling, Changquan

    2015-02-01

    Diosgenin is a major compound of Dioscoreaceae plants such as yam, which is used as a drug in Traditional Chinese Medicine, and a common vegetable worldwide. The anticancer effect of diosgenin has been reported in various tumor cells, including leukemia, gastric, colorectal, and breast cancer. However, the activity of diosgenin on hepatocellular carcinoma (HCC) and the underlying mechanism have not been completely investigated. Therefore, we investigated the efficacy and associated mechanisms of diosgenin in HCC cells. Flow cytometric analysis was performed to determine the presence of cell cycle arrest and apopotic cells. Diosgenin significantly inhibited the growth of Bel-7402, SMMC-7721 and HepG2 HCC cells in a concentration-dependent manner. Diosgenin treatment for 24 h induced G2/M cell cycle arrest and apoptosis of hepatoma cells. Diosgenin inhibited Akt phosphorylation and upregulated p21 and p27 expression, but did not alter the expression of p53, suggesting diosgenin-induced upregulation of p21 and p57 is p53-independent in HCC cells. Diosgenin induced HCC cell apoptosis by activating caspase cascades -3, -8 and -9. However, diosgenin did not affect Bcl-2 and Bax levels. In conclusion, results of the present study suggest that diosgenin may be an active anti-HCC agent obtained from natural plants and provide new insights in understanding the mechanisms of diosgenin. PMID:25434486

  19. Fusarochromanone Induces G1 Cell Cycle Arrest and Apoptosis in COS7 and HEK293 Cells

    PubMed Central

    Gu, Ying; Chen, Xin; Shang, Chaowei; Singh, Karnika; Barzegar, Mansoureh; Mahdavian, Elahe; Salvatore, Brian A.; Jiang, Shanxiang; Huang, Shile

    2014-01-01

    Fusarochromanone (FC101), a mycotoxin produced by the fungus Fusarium equiseti, is frequently observed in the contaminated grains and feedstuffs, which is toxic to animals and humans. However, the underlying molecular mechanism remains to be defined. In this study, we found that FC101 inhibited cell proliferation and induced cell death in COS7 and HEK293 cells in a concentration-dependent manner. Flow cytometric analysis showed that FC101 induced G1 cell cycle arrest and apoptosis in the cells. Concurrently, FC101 downregulated protein expression of cyclin D1, cyclin-dependent kinases (CDK4 and CDK6), and Cdc25A, and upregulated expression of the CDK inhibitors (p21Cip1 and p27Kip1), resulting in hypophosphorylation of Rb. FC101 also inhibited protein expression of Bcl-2, Bcl-xL, Mcl-1 and survivin, and induced expression of BAD, leading to activation of caspase 3 and cleavage of PARP, indicating caspase-dependent apoptosis. However, Z-VAD-FMK, a pan-caspase inhibitor, only partially prevented FC101-induced cell death, implying that FC101 may induce cell death through both caspase-dependent and -independent mechanisms. Our results support the notion that FC101 executes its toxicity at least by inhibiting cell proliferation and inducing cell death. PMID:25384025

  20. Endothelial nitric oxide synthase deficiency influences normal cell cycle progression and apoptosis in trabecular meshwork cells

    PubMed Central

    Liao, Qiong; Huang, Yan-Ming; Fan, Wei; Li, Chan; Yang, Hong

    2016-01-01

    AIM To clarify how the endothelial nitric oxide synthase (eNOS, NOS3) make effect on outflow facility through the trabecular meshwork (TM). METHODS Inhibition of NOS3 gene expression in human TM cells were conducted by three siRNAs. Then the mRNA and protein levels of NOS3 in siRNA-treated and negative control (NC) cells were determined, still were the collagen, type IV, alpha 1 (COL4A1) and fibronectin 1 by real-time PCR and Western blot analysis. In addition, NOS3 concentrations in culture supernatant fluids of TM cells were measured. Cell cycle and cell apoptosis analysis were performed using flow cytometry. RESULTS The mRNA level of NOS3 was decreased by three different siRNA interference, similar results were obtained not only of the relative levels of NOS3 protein, but also the expression levels of COL4A1 and fibronectin 1. The number of cells in S phase was decreased, while contrary result was obtained in G2 phase. The number of apoptotic cells in siRNA-treated groups were significant increased compared to the NC samples. CONCLUSION Abnormal NOS3 expression can make effects on the proteins levels of extracellular matrix component (e.g. fibronectin 1 and COL4A1). Reduced NOS3 restrains the TM cell cycle progression at the G2/M-phase transition and induced cell apoptosis. PMID:27366677

  1. A Novel Isoform of the B Cell Tyrosine Kinase BTK Protects Breast Cancer Cells from Apoptosis

    PubMed Central

    Eifert, Cheryl; Wang, Xianhui; Kokabee, Leila; Kourtidis, Antonis; Jain, Ritu; Gerdes, Michael J.; Conklin, Douglas S.

    2016-01-01

    Tyrosine kinases orchestrate key cellular signaling pathways and their dysregulation is often associated with cellular transformation. Several recent cases in which inhibitors of tyrosine kinases have been successfully used as anticancer agents have underscored the importance of this class of proteins in the development of targeted cancer therapies. We have carried out a large-scale loss-of-function analysis of the human tyrosine kinases using RNA interference to identify novel survival factors for breast cancer cells. In addition to kinases with known roles in breast and other cancers, we identified several kinases that were previously unknown to be required for breast cancer cell survival. The most surprising of these was the cytosolic, nonreceptor tyrosine kinase, Bruton’s tyrosine kinase (BTK), which has been extensively studied in B cell development. Down regulation of this protein with RNAi or inhibition with pharmacological inhibitors causes apoptosis; overexpression inhibits apoptosis induced by Doxorubicin in breast cancer cells. Our results surprisingly show that BTK is expressed in several breast cancer cell lines and tumors. The predominant form of BTK found in tumor cells is transcribed from an alternative promoter and results in a protein with an amino-terminal extension. This alternate form of BTK is expressed at significantly higher levels in tumorigenic breast cells than in normal breast cells. Since this protein is a survival factor for these cells, it represents both a potential marker and novel therapeutic target for breast cancer. PMID:23913792

  2. Puerarin Induces Mitochondria-Dependent Apoptosis in Hypoxic Human Pulmonary Arterial Smooth Muscle Cells

    PubMed Central

    Chen, Chan; Chen, Chun; Wang, Zhiyi; Wang, Liangxing; Yang, Lehe; Ding, Minjiao; Ding, Cheng; Sun, Yu; Lin, Quan; Huang, Xiaoying; Du, Xiaohong; Zhao, Xiaowei; Wang, Chuangyi

    2012-01-01

    Background Pulmonary vascular medial hypertrophy in hypoxic pulmonary arterial hypertension (PAH) is caused in part by decreased apoptosis in pulmonary artery smooth muscle cells (PASMCs). Puerarin, an isoflavone purified from the Chinese medicinal herb kudzu, ameliorates chronic hypoxic PAH in animal models. Here we investigated the effects of puerarin on apoptosis of hypoxic human PASMCs (HPASMCs), and to determine the possible underlying mechanisms. Methodology/Principal Findings HPASMCs were cultured for 24 h in normoxia or hypoxia (5% O2) conditions with and without puerarin. Cell number and viability were determined with a hemacytometer or a cell counting kit. Apoptosis was detected with a TUNEL test, rhodamine-123 (R-123) fluorescence, a colorimetric assay, western blots, immunohistochemical staining and RT-PCR. Hypoxia inhibited mitochondria-dependent apoptosis and promoted HPASMC growth. In contrast, after puerarin (50 µM or more) intervention, cell growth was inhibited and apoptosis was observed. Puerarin-induced apoptosis in hypoxic HPASMCs was accompanied by reduced mitochondrial membrane potential, cytochrome c release from the mitochondria, caspase-9 activation, and Bcl-2 down-regulation with concurrent Bax up-regulation. Conclusions/Significance Puerarin promoted apoptosis in hypoxic HPASMCs by acting on the mitochondria-dependent pathway. These results suggest a new mechanism of puerarin relevant to the management of clinical hypoxic pulmonary hypertension. PMID:22457823

  3. An increase in epithelial cell apoptosis is associated with chronic intestinal nematode infection.

    PubMed

    Cliffe, Laura J; Potten, Christopher S; Booth, Catherine E; Grencis, Richard K

    2007-04-01

    It is well established that homeostasis of the intestinal epithelium becomes dysregulated during gastrointestinal helminth infection and is under immune control. An increase in both enterocyte proliferation and the subsequent generation of crypt hyperplasia are hallmarks of chronic infection with Trichuris muris, a large intestinal dwelling nematode. The effect of this parasitic infection on apoptosis induction in the large intestine and its regulation has been neglected. To address this, mice of resistant and susceptible phenotypes were infected with different doses of T. muris, and the levels of epithelial cell apoptosis were determined. It is clear that apoptosis is induced during chronic T. muris infection. This occurs mainly at the base of the cecal crypt, within the stem cell region. The level of apoptosis induced is independent of worm number, suggesting that it is not a consequence of worm-induced damage but rather a mechanism for controlling cell number within the crypt. Neutralization of both gamma interferon and tumor necrosis factor alpha caused a significant reduction in the levels of apoptosis, showing that proinflammatory cytokines generated in response to chronic infection play an important role in apoptosis induction in this system. It is proposed that the generation of proinflammatory cytokines during chronic T. muris infection may play a positive role, by promoting intestinal epithelial cell apoptosis, to counter infection-induced epithelial hyperplasia. PMID:17242061

  4. Sensing lymphoma cells based on a cell-penetrating/apoptosis-inducing/electron-transfer peptide probe.

    PubMed

    Sugawara, Kazuharu; Shinohara, Hiroki; Kadoya, Toshihiko; Kuramitz, Hideki

    2016-06-14

    To electrochemically sense lymphoma cells (U937), we fabricated a multifunctional peptide probe that consists of cell-penetrating/apoptosis-inducing/electron-transfer peptides. Electron-transfer peptides derive from cysteine residue combined with the C-terminals of four tyrosine residues (Y4). A peptide whereby Y4C is bound to the C-terminals of protegrin 1 (RGGRLCYCRRRFCVCVGR-NH2) is known to be an apoptosis-inducing agent against U937 cells, and is referred to as a peptide-1 probe. An oxidation response of the peptide-1 probe has been observed due to a phenolic hydroxyl group, and this response is decreased by the uptake of the peptide probe into the cells. To improve the cell membrane permeability against U937 cells, the RGGR at the N-terminals of the peptide-1 probe was replaced by RRRR (peptide-2 probe). In contrast, RNRCKGTDVQAWY4C (peptide-3 probe), which recognizes ovalbumin, was constructed as a control. Compared with the other probes, the change in the peak current of the peptide-2 probe was the greatest at low concentrations and occurred in a short amount of time. Therefore, the cell membrane permeability of the peptide-2 probe was increased based on the arginine residues and the apoptosis-inducing peptides. The peak current was linear and ranged from 100 to 1000 cells/ml. The relative standard deviation of 600 cells/ml was 5.0% (n = 5). Furthermore, the membrane permeability of the peptide probes was confirmed using fluorescent dye. PMID:27181650

  5. Sodium arsenite accelerates TRAIL-mediated apoptosis in melanoma cells through upregulation of TRAIL-R1/R2 surface levels and downregulation of cFLIP expression

    SciTech Connect

    Ivanov, Vladimir N. . E-mail: vni3@columbia.edu; Hei, Tom K.

    2006-12-10

    AP-1/cJun, NF-{kappa}B and STAT3 transcription factors control expression of numerous genes, which regulate critical cell functions including proliferation, survival and apoptosis. Sodium arsenite is known to suppress both the IKK-NF-{kappa}B and JAK2-STAT3 signaling pathways and to activate the MAPK/JNK-cJun pathways, thereby committing some cancers to undergo apoptosis. Indeed, sodium arsenite is an effective drug for the treatment of acute promyelocytic leukemia with little nonspecific toxicity. Malignant melanoma is highly refractory to conventional radio- and chemotherapy. In the present study, we observed strong effects of sodium arsenite treatment on upregulation of TRAIL-mediated apoptosis in human and mouse melanomas. Arsenite treatment upregulated surface levels of death receptors, TRAIL-R1 and TRAIL-R2, through increased translocation of these proteins from cytoplasm to the cell surface. Furthermore, activation of cJun and suppression of NF-{kappa}B by sodium arsenite resulted in upregulation of the endogenous TRAIL and downregulation of the cFLIP gene expression (which encodes one of the main anti-apoptotic proteins in melanomas) followed by cFLIP protein degradation and, finally, by acceleration of TRAIL-induced apoptosis. Direct suppression of cFLIP expression by cFLIP RNAi also accelerated TRAIL-induced apoptosis in these melanomas, while COX-2 suppression substantially increased levels of both TRAIL-induced and arsenite-induced apoptosis. In contrast, overexpression of permanently active AKTmyr inhibited TRAIL-mediated apoptosis via downregulation of TRAIL-R1 levels. Finally, AKT overactivation increased melanoma survival in cell culture and dramatically accelerated growth of melanoma transplant in vivo, highlighting a role of AKT suppression for effective anticancer treatment.

  6. Clioquinol and pyrrolidine dithiocarbamate complex with copper to form proteasome inhibitors and apoptosis inducers in human breast cancer cells

    PubMed Central

    Daniel, Kenyon G; Chen, Di; Orlu, Shirley; Cui, Qiuzhi Cindy; Miller, Fred R; Dou, Q Ping

    2005-01-01

    similar to those found in patients, when treated with just CQ or PDTC alone, but not TM, undergo proteasome inhibition and apoptosis. Conclusion The feature of breast cancer cells and tissues to accumulate copper can be used as a targeting method for anticancer therapy through treatment with novel compounds such as CQ and PDTC that become active proteasome inhibitors and breast cancer cell killers in the presence of copper. PMID:16280039

  7. Modulation of tumor necrosis factor-related apoptosis-inducing ligand-induced apoptosis by chemotherapy in thyroid cancer cell lines.

    PubMed

    Park, Jin-Woo; Wong, Mariwil G; Lobo, Margaret; Hyun, William C; Duh, Quan-Yang; Clark, Orlo H

    2003-12-01

    Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces apoptosis in many human cancer cells but not in normal cells. Thyroid cancer cells, however, appear to be relatively resistant to TRAIL-induced apoptosis. We therefore investigated the effect of chemotherapy on TRAIL-induced apoptosis in thyroid cancer cells. We used six thyroid cancer cell lines: TPC-1, FTC-133, FTC-236, FTC-238, XTC-1, and ARO82-1. We used flow cytometry to measure apoptosis, dimethyl-thiazol-diphenyltetrazolium bromide (MTT) assay to measure antiproliferation effects and Western blot to determine the expression of Bcl family proteins. Troglitazone, paclitaxel, geldanamycin, and cycloheximide were used for pretreatment. We used the Student's t test and analysis of variance (ANOVA) for statistical analysis. All thyroid cancer cell lines, except the TPC-1 cell line, were resistant to TRAIL, and growth inhibition was less than 20% at concentration of 800 ng/mL of TRAIL. In both TPC-1 (TRAIL-sensitive) and FTC-133 (TRAIL-resistant) thyroid cancer cell lines, pretreatment with troglitazone, cycloheximide, and paclitaxel enhanced TRAIL-induced cell death significantly but pretreatment with geldanamycin did not. There were no significant changes in Bcl-2, Bcl-xl, and Bax protein expression after troglitazone treatment. In conclusion, TRAIL in combination with troglitazone, paclitaxel, and cycloheximide induces apoptosis in thyroid cancer cells at suboptimal concentrations that cannot be achieved using TRAIL alone. PMID:14751030

  8. p53 modulates the AMPK inhibitor compound C induced apoptosis in human skin cancer cells

    SciTech Connect

    Huang, Shi-Wei; Wu, Chun-Ying; Wang, Yen-Ting; Kao, Jun-Kai; Lin, Chi-Chen; Chang, Chia-Che; Mu, Szu-Wei; Chen, Yu-Yu; Chiu, Husan-Wen; Chang, Chuan-Hsun; Liang, Shu-Mei; Chen, Yi-Ju; Huang, Jau-Ling; Shieh, Jeng-Jer

    2013-02-15

    Compound C, a well-known inhibitor of the intracellular energy sensor AMP-activated protein kinase (AMPK), has been reported to cause apoptotic cell death in myeloma, breast cancer cells and glioma cells. In this study, we have demonstrated that compound C not only induced autophagy in all tested skin cancer cell lines but also caused more apoptosis in p53 wildtype skin cancer cells than in p53-mutant skin cancer cells. Compound C can induce upregulation, phosphorylation and nuclear translocalization of the p53 protein and upregulate expression of p53 target genes in wildtype p53-expressing skin basal cell carcinoma (BCC) cells. The changes of p53 status were dependent on DNA damage which was caused by compound C induced reactive oxygen species (ROS) generation and associated with activated ataxia-telangiectasia mutated (ATM) protein. Using the wildtype p53-expressing BCC cells versus stable p53-knockdown BCC sublines, we present evidence that p53-knockdown cancer cells were much less sensitive to compound C treatment with significant G2/M cell cycle arrest and attenuated the compound C-induced apoptosis but not autophagy. The compound C induced G2/M arrest in p53-knockdown BCC cells was associated with the sustained inactive Tyr15 phosphor-Cdc2 expression. Overall, our results established that compound C-induced apoptosis in skin cancer cells was dependent on the cell's p53 status. - Highlights: ► Compound C caused more apoptosis in p53 wildtype than p53-mutant skin cancer cells. ► Compound C can upregulate p53 expression and induce p53 activation. ► Compound C induced p53 effects were dependent on ROS induced DNA damage pathway. ► p53-knockdown attenuated compound C-induced apoptosis but not autophagy. ► Compound C-induced apoptosis in skin cancer cells was dependent on p53 status.

  9. Antiaging Gene Klotho Attenuates Pancreatic β-Cell Apoptosis in Type 1 Diabetes.

    PubMed

    Lin, Yi; Sun, Zhongjie

    2015-12-01

    Apoptosis is the major cause of death of insulin-producing β-cells in type 1 diabetes mellitus (T1DM). Klotho is a recently discovered antiaging gene. We found that the Klotho gene is expressed in pancreatic β-cells. Interestingly, halplodeficiency of Klotho (KL(+/-)) exacerbated streptozotocin (STZ)-induced diabetes (a model of T1DM), including hyperglycemia, glucose intolerance, diminished islet insulin storage, and increased apoptotic β-cells. Conversely, in vivo β-cell-specific expression of mouse Klotho gene (mKL) attenuated β-cell apoptosis and prevented STZ-induced diabetes. mKL promoted cell adhesion to collagen IV, increased FAK and Akt phosphorylation, and inhibited caspase 3 cleavage in cultured MIN6 β-cells. mKL abolished STZ- and TNFα-induced inhibition of FAK and Akt phosphorylation, caspase 3 cleavage, and β-cell apoptosis. These promoting effects of Klotho can be abolished by blocking integrin β1. Therefore, these cell-based studies indicated that Klotho protected β-cells by inhibiting β-cell apoptosis through activation of the integrin β1-FAK/Akt pathway, leading to inhibition of caspase 3 cleavage. In an autoimmune T1DM model (NOD), we showed that in vivo β-cell-specific expression of mKL improved glucose tolerance, attenuated β-cell apoptosis, enhanced insulin storage in β-cells, and increased plasma insulin levels. The beneficial effect of Klotho gene delivery is likely due to attenuation of T-cell infiltration in pancreatic islets in NOD mice. Overall, our results demonstrate for the first time that Klotho protected β-cells in T1DM via attenuating apoptosis. PMID:26340932

  10. Disruption of pairing and synapsis of chromosomes causes stage-specific apoptosis of male meiotic cells.

    PubMed

    Hamer, G; Novak, I; Kouznetsova, A; Höög, C

    2008-02-01

    During meiosis, DNA replication is followed by two successive rounds of chromosome segregation (meiosis I and II), which give rise to genetically diverse haploid gametes. The prophase of the first meiotic division is highly regulated and alignment and synapsis of the homologous chromosomes during this stage are mediated by the synaptonemal complex. Incorrect assembly of the synaptonemal complex results in cell death, impaired meiotic recombination and aneuploidy. Oocytes with meiotic defects often survive the first meiotic prophase and give rise to aneuploid gametes. Similarly affected spermatocytes, on the other hand, almost always undergo apoptosis at a male-specific meiotic checkpoint, located specifically at epithelial stage IV during spermatogenesis. Many examples of this stage IV-specific arrest have been described for several genetic mouse models in which DNA repair or meiotic recombination are abrogated. Interestingly, in C. elegans, meiotic recombination and synapsis are monitored by two separate checkpoint pathways. Therefore we studied spermatogenesis in several knockout mice (Sycp1(-/-), Sycp3(-/-), Smc1beta(-/-) and Sycp3/Sycp1 and Sycp3/Smc1beta double-knockouts) that are specifically defective in meiotic pairing and synapsis. Like for recombination defects, we found that all these genotypes also specifically arrest at epithelial stage IV. It seems that the epithelial stage IV checkpoint eliminates spermatocytes that fail a certain quality check, being either synapsis or DNA damage related. PMID:17997150

  11. Akt inhibition improves irinotecan treatment and prevents cell emergence by switching the senescence response to apoptosis

    PubMed Central

    Vétillard, Alexandra; Jonchère, Barbara; Moreau, Marie; Toutain, Bertrand; Henry, Cécile; Fontanel, Simon; Bernard, Anne-Charlotte; Campone, Mario; Guette, Catherine; Coqueret, Olivier

    2015-01-01

    Activated in response to chemotherapy, senescence is a tumor suppressive mechanism that induces a permanent loss of proliferation. However, in response to treatment, it is not really known how cells can escape senescence and how irreversible or incomplete this pathway is. We have recently described that cells that escape senescence are more transformed than non-treated parental cells, they resist anoikis and rely on Mcl-1. In this study, we further characterize this emergence in response to irinotecan, a first line treatment used in colorectal cancer. Our results indicate that Akt was activated as a feedback pathway during the early step of senescence. The inhibition of the kinase prevented cell emergence and improved treatment efficacy, both in vitro and in vivo. This improvement was correlated with senescence inhibition, p21waf1 downregulation and a concomitant activation of apoptosis due to Noxa upregulation and Mcl-1 inactivation. The inactivation of Noxa prevented apoptosis and increased the number of emergent cells. Using either RNA interference or p21waf1-deficient cells, we further confirmed that an intact p53-p21-senescence pathway favored cell emergence and that its downregulation improved treatment efficacy through apoptosis induction. Therefore, although senescence is an efficient suppressive mechanism, it also generates more aggressive cells as a consequence of apoptosis inhibition. We therefore propose that senescence-inducing therapies should be used sequentially with drugs favoring cell death such as Akt inhibitors. This should reduce cell emergence and tumor relapse through a combined induction of senescence and apoptosis. PMID:26485768

  12. Multiple effects of TRAIL in human carcinoma cells: Induction of apoptosis, senescence, proliferation, and cytokine production

    SciTech Connect

    Levina, Vera; Marrangoni, Adele M.; DeMarco, Richard; Gorelik, Elieser; Lokshin, Anna E.

    2008-04-15

    TRAIL is a death ligand that induces apoptosis in malignant but not normal cells. Recently the ability of TRAIL to induce proliferation in apoptosis-resistant normal and malignant cells was reported. In this study, we analyzed TRAIL effects in apoptosis sensitive MCF7, OVCAR3 and H460 human tumor cell lines. TRAIL at low concentrations preferentially induced cell proliferation. At 100 ng/ml, apoptotic death was readily observed, however surviving cells acquired higher proliferative capacity. TRAIL-stimulated production of several cytokines, IL-8, RANTES, MCP-1 and bFGF, and activation of caspases 1 and 8 was essential for this effect. Antibodies to IL-8, RANTES, and bFGF blocked TRAIL-induced cell proliferation and further stimulated apoptosis. For the first time, we report that high TRAIL concentrations induced cell senescence as determined by the altered morphology and expression of several senescence markers: SA-{beta}-gal, p21{sup Waf1/Cip1}, p16{sup INK4a}, and HMGA. Caspase 9 inhibition protected TRAIL-treated cells from senescence, whereas inhibition of caspases 1 and 8 increased the yield of SLP cells. In conclusion, in cultured human carcinoma cells, TRAIL therapy results in three functional outcomes, apoptosis, proliferation and senescence. TRAIL-induced proapoptotic and prosurvival responses correlate with the strength of signaling. TRAIL-induced cytokine production is responsible for its proliferative and prosurvival effects.

  13. Non-cell autonomous control of apoptosis by ligand-independent Hedgehog signaling in Drosophila

    PubMed Central

    Christiansen, A E; Ding, T; Fan, Y; Graves, H K; Herz, H-M; Lindblad, J L; Bergmann, A

    2013-01-01

    Hedgehog (Hh) signaling is important for development and homeostasis in vertebrates and invertebrates. Ligand-independent, deregulated Hh signaling caused by loss of negative regulators such as Patched causes excessive cell proliferation, leading to overgrowth in Drosophila and tumors in humans, including basal-cell carcinoma and medulloblastoma. We show that in Drosophila deregulated Hh signaling also promotes cell survival by increasing the resistance to apoptosis. Surprisingly, cells with deregulated Hh activity do not protect themselves from apoptosis; instead, they promote cell survival of neighboring wild-type cells. This non-cell autonomous effect is mediated by Hh-induced Notch signaling, which elevates the protein levels of Drosophila inhibitor of apoptosis protein-1 (Diap-1), conferring resistance to apoptosis. In summary, we demonstrate that deregulated Hh signaling not only promotes proliferation but also cell survival of neighboring cells. This non-cell autonomous control of apoptosis highlights an underappreciated function of deregulated Hh signaling, which may help to generate a supportive micro-environment for tumor development. PMID:23018595

  14. Humanin protects against chemotherapy-induced stage-specific male germ cell apoptosis in rats.

    PubMed

    Surampudi, P; Chang, I; Lue, Y; Doumit, T; Jia, Y; Atienza, V; Liu, P Y; Swerdloff, R S; Wang, C

    2015-05-01

    Humanin (HN) has cytoprotective action on male germ cells after testicular stress induced by heat and hormonal deprivation. To examine whether HN has protective effects on chemotherapy-induced male germ cell apoptosis, we treated four groups of adult rats with (i) vehicle (control), (ii) HN, (iii) cyclophosphamide (CP); or (iv) HN+CP. To investigate whether the protective effects of HN on germ cells require the presence of Leydig cells, another four groups of rats were pre-treated with ethane dimethanesulfonate (EDS), a Leydig cell toxicant, to eliminate Leydig cells. After 3 days, when Leydig cells were depleted by EDS, we administered: (i) vehicle, (ii) HN, (iii) CP; or (iv) HN+CP to rats. All rats were killed 12 h after the injection of HN and/or CP. Germ cell apoptosis was detected by TUNEL assay and quantified by numerical count. Compared with control and HN (alone), CP significantly increased germ cell apoptosis; HN +CP significantly reduced CP-induced apoptosis at early (I-VI) and late stages (IX-XIV) but not at middle stages (VII-VIII) of the seminiferous epithelial cycle. Pre-treatment with EDS markedly suppressed serum and intratesticular testosterone (T) levels, and significantly increased germ cell apoptosis at the middle (VII-VIII) stages. CP did not further increase germ cell apoptosis in the EDS-pre-treated rats. HN significantly attenuated germ cell apoptosis at the middle stages in EDS pre-treated rats. To investigate whether HN has any direct effects on Leydig cell function, adult Leydig cells were isolated and treated with ketoconazole (KTZ) to block testosterone synthesis. HN was not effective in preventing the reduction of T production by KTZ in vitro. We conclude that HN decreases CP and/or EDS-induced germ cell apoptosis in a stage-specific fashion. HN acts directly on germ cells to protect against EDS-induced apoptosis in the absence of Leydig cells and intratesticular testosterone levels are very low. PMID:25891800

  15. Cancer cell(s) cycle sequencing reveals universal mechanisms of apoptosis.

    PubMed

    Marretta, R M Ardito; Ales, F

    2010-12-01

    In this paper, cell cycle in higher eukaryotes and their molecular networks signals both in G1/S and G2/M transitions are replicated in silico. Biochemical kinetics, converted into a set of differential equations, and system control theory are employed to design multi-nested digital layers to simulate protein-to-protein activation and inhibition for cell cycle dynamics in the presence of damaged genomes. Sequencing and controlling the digital process of four micro-scale species networks (p53/Mdm2/DNA damage, p21mRNA/cyclin-CDK complex, CDK/CDC25/weel/SKP2/APC/CKI and apoptosis target genes system) not only allows the comprehension of the mechanisms of these molecule interactions but paves the way for unraveling the participants and their by-products, until now quite unclear, which have the task of carrying out (or not) cell death. Whatever the running simulations (e.g., different species signals, mutant cells and different DNA damage levels), the results of the proposed cell digital multi-layers give reason to believe in the existence of a universal apoptotic mechanism. As a consequence, we identified and selected cell check points, sizers, timers and specific target genes dynamic both for influencing mitotic process and avoiding cancer proliferation as much as for leading the cancer cell(s) to collapse into a steady stable apoptosis phase. PMID:21141676

  16. Octamer 4 small interfering RNA results in cancer stem cell-like cell apoptosis.

    PubMed

    Hu, Tingsong; Liu, Shanrong; Breiter, Deborah R; Wang, Fang; Tang, Ying; Sun, Shuhan

    2008-08-15

    Octamer 4 (Oct4), a member of the POU family of transcription factors, plays a key role in the maintenance of pluripotency and proliferation potential of embryonic stem cells. Cancer stem cell-like cells (CSCLC) are reported to be a minor population in tumors or even in tumor cell lines which also express Oct4. The role of Oct4 in CSCLCs still remains to be defined. In our study, we show that, in vitro, almost all murine Lewis lung carcinoma 3LL cells and human breast cancer MCF7 cells express Oct4 at high levels. This expression of Oct4 is successfully reduced by small interfering RNA, which eventually results in cell apoptosis. The signal pathway Oct4/Tcl1/Akt1 has been observed to be involved in this event. The repression of Oct4 reduces Tcl1 expression and further down-regulates the level of p-Ser.473-Akt1. In vivo, only approximately 5% of tumor cells were detected to express Oct4 in established 3LL and MCF7 tumor models, respectively. Small interfering RNA against Oct4 successfully decreases the CSCLCs and markedly inhibits tumor growth. In summary, we show that Oct4 might maintain the survival of CSCLCs partly through Oct4/Tcl1/Akt1 by inhibiting apoptosis, which strongly indicates that targeting Oct4 may have important clinical applications in cancer therapy. PMID:18701476

  17. SK053 triggers tumor cells apoptosis by oxidative stress-mediated endoplasmic reticulum stress.

    PubMed

    Muchowicz, Angelika; Firczuk, Małgorzata; Wachowska, Małgorzata; Kujawa, Marek; Jankowska-Steifer, Ewa; Gabrysiak, Magdalena; Pilch, Zofia; Kłossowski, Szymon; Ostaszewski, Ryszard; Golab, Jakub

    2015-02-15

    Thioredoxins (Trx) together with thioredoxin reductases (TrxR) participate in the maintenance of protein thiol homeostasis and play cytoprotective roles in tumor cells. Therefore, thioredoxin-thioredoxin reductase system is considered to be a promising therapeutic target in cancer treatment. We have previously reported that SK053, a peptidomimetic compound targeting the thioredoxin-thioredoxin reductase system, induces oxidative stress and demonstrates antitumor activity in mice. In this study, we investigated the mechanisms of SK053-mediated tumor cell death. Our results indicate that SK053 induces apoptosis of Raji cells accompanied by the activation of the endoplasmic reticulum (ER) stress and induction of unfolded protein response. Incubation of tumor cells with SK053 induces increase in BiP, CHOP, and spliced XBP-1 levels, which precede induction of apoptosis. CHOP-deficient (CHOP(-/-)) mouse embryonic fibroblasts are more resistant to SK053-induced apoptosis as compared with normal fibroblasts indicating that the apoptosis of tumor cells depends on the expression of this transcription factor. Additionally, the ER-stress-induced apoptosis, caused by SK053, is strongly related with Trx expression levels. Altogether, our results indicate that SK053 induces ER stress-associated apoptosis and reveal a link between thioredoxin inhibition and induction of UPR in tumor cells. PMID:25573101

  18. Evaluation of the antiproliferative activity of diterpene isonitriles from the sponge Pseudoaxinella flava in apoptosis-sensitive and apoptosis-resistant cancer cell lines.

    PubMed

    Lamoral-Theys, Delphine; Fattorusso, Ernesto; Mangoni, Alfonso; Perinu, Cristina; Kiss, Robert; Costantino, Valeria

    2011-10-28

    One new (1) and three known (2-4) isonitrile diterpenes, isolated from the Caribbean sponge Pseudoaxinella flava, were assayed in human cancer cell lines in vitro using an MTT colorimetric assay and quantitative videomicroscopy. Compounds 1-4 displayed activity for human PC3 prostate apoptosis-sensitive cancer cell lines. Compounds 3 and 4 demonstrated similar growth inhibitory effects for three apoptosis-sensitive and three apoptosis-resistant cancer cell lines. Quantitative videomicroscopy analysis revealed that compounds 1 and 2 exerted their activity through cytotoxic effects, and compounds 3 and 4 through cytostatic effects. These results identify marine diterpene isonitriles as potential lead compounds for anticancer drug discovery. PMID:21985105

  19. Differential sensitivity of naive and memory CD8+ T cells to apoptosis in vivo.

    PubMed

    Grayson, Jason M; Harrington, Laurie E; Lanier, J Gibson; Wherry, E John; Ahmed, Rafi

    2002-10-01

    Apoptosis is a critical regulator of homeostasis in the immune system. In this study we demonstrate that memory CD8(+) T cells are more resistant to apoptosis than naive cells. After whole body irradiation of mice, both naive and memory CD8(+) T cells decreased in number, but the reduction in the number of naive cells was 8-fold greater than that in memory CD8(+) T cells. In addition to examining radiation-induced apoptosis, we analyzed the expansion and contraction of naive and memory CD8(+) T cells in vivo following exposure to Ag. We found that memory CD8(+) T cells not only responded more quickly than naive cells after viral infection, but that secondary effector cells generated from memory cells underwent much less contraction compared with primary effectors generated from naive cells (3- to 5-fold vs 10- to 20-fold decrease). Increased numbers of secondary memory cells were observed in both lymphoid and non-lymphoid tissues. When naive and memory cells were transferred into the same animal, secondary effectors underwent less contraction than primary effector cells. These experiments analyzing apoptosis of primary and secondary effectors in the same animal show unequivocally that decreased downsizing of the secondary response reflects an intrinsic property of the memory T cells and is not simply due to environmental effects. These findings have implications for designing prime/boost vaccine strategies and also for optimizing immunotherapeutic regimens for treatment of chronic infections. PMID:12244170

  20. Thymosin Beta-4 Recombinant Adeno-associated Virus Enhances Human Nucleus Pulposus Cell Proliferation and Reduces Cell Apoptosis and Senescence

    PubMed Central

    Wang, Yuan-Yi; Zhu, Qing-San; Wang, Yi-Wei; Yin, Ruo-Feng

    2015-01-01

    Background: Thymosin beta-4 (TB-4) is considered key roles in tissue development, maintenance and pathological processes. The study aimed to prove TB-4 positive biological function on nucleus pulposus (NP) cell apoptosis and slowing the process of cell aging while increasing the cell proliferation. Methods: TB-4 recombinant adeno-associated virus (AAV) was constructed and induced to human NP cells. Cell of same group were cultured without gene modification as controlled group. Proliferation capacity and cell apoptosis were observed during 6 passages of the cells. Morphology and expression of the TB-4 gene were documented as parameter of cell activity during cell passage. Results: NP cells with TB-4 transfection has normal TB-4 expression and exocytosis. NP cells with TB-4 transfection performed significantly higher cell activity than that at the control group in each generation. TB-4 recombinant AAV-transfected human NP cells also show slower cell aging, lower cell apoptosis and higher cell proliferation than control group. Conclusions: TB-4 can prevent NP cell apoptosis, slow NP cell aging and promote NP cell proliferation. AAV transfection technique was able to highly and stably express TB-4 in human NP cells, which may provide a new pathway for innovation in the treatment of intervertebral disc degenerative diseases. PMID:26021512