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Sample records for ab-dependent cellular cytotoxicity

  1. Antibody-dependent cellular cytotoxicity and skin disease

    SciTech Connect

    Norris, D.A.; Lee, L.A.

    1985-07-01

    Antibody dependent cellular cytotoxicity (ADCC) is a recently described mechanism of immunologic lysis in which cellular targets sensitized by specific antibodies are efficiently and selectively lysed by Fc receptor (FcR) bearing nonspecific effectors. Immunoglobulins of various classes (IgG, IgM, IgA, IgE) and various cellular effectors (large granular lymphocytes, monocyte/macrophages, T lymphocytes, neutrophils, and eosinophils) can induce ADCC in vitro, and the importance of ADCC in vivo is being tested experimentally in resistance to viral, bacterial, and parasitic infection, in tumor surveillance, in allograft rejection, and in inflammatory diseases. There is much indirect evidence that ADCC may be the mechanism of damage of different cellular targets in skin diseases, but the best direct evidence concerns immunologic keratinocyte damage, especially in cutaneous lupus erythematosus (LE). The authors have shown that keratinocytes of several species are highly susceptible to lymphocyte and monocyte-mediated ADCC, but not to neutrophil or eosinophil ADCC in vitro using two different cytotoxicity assays. In contrast, complement was a relatively ineffective mediator of lysis of metabolically intact keratinocyte targets. Patients with certain cutaneous lupus syndromes have serum antibodies capable of inducing monocyte and lymphocyte ADCC of targets coated with extractable nuclear antigens. The authors have shown that these antigens apparently move to the cell membrane of keratinocytes in vitro following ultraviolet irradiation. In an animal model, they have shown that antibodies to SSA/Ro bind to human keratinocytes in vivo, especially after ultraviolet irradiation.

  2. Synthesis of New Styrylquinoline Cellular Dyes, Fluorescent Properties, Cellular Localization and Cytotoxic Behavior

    PubMed Central

    Dulski, Mateusz; Mrozek-Wilczkiewicz, Anna; Cieslik, Wioleta; Spaczyńska, Ewelina; Bartczak, Piotr; Ratuszna, Alicja; Polanski, Jaroslaw; Musiol, Robert

    2015-01-01

    New styrylquinoline derivatives with their photophysical constants are described. The synthesis was achieved via Sonogashira coupling using the newly developed heterogeneous nano-Pd/Cu catalyst system, which provides an efficient synthesis of high purity products. The compounds were tested in preliminary fluorescent microscopy studies to in order to identify their preferable cellular localization, which appeared to be in the lipid cellular organelles. The spectroscopic properties of the compounds were measured and theoretical TD-DFT calculations were performed. A biological analysis of the quinolines that were tested consisted of cytotoxicity assays against normal human fibroblasts and colon adenocarcinoma cells. All of the compounds that were studied appeared to be safe and indifferent to cells in a high concentration range. The presented results suggest that the quinoline compounds that were investigated in this study may be valuable structures for development as fluorescent dyes that could have biological applications. PMID:26114446

  3. Cutting edge: An antibody recognizing ancestral endogenous virus glycoproteins mediates antibody-dependent cellular cytotoxicity on HIV-1-infected cells.

    PubMed

    Michaud, Henri-Alexandre; SenGupta, Devi; de Mulder, Miguel; Deeks, Steven G; Martin, Jeffrey N; Kobie, James J; Sacha, Jonah B; Nixon, Douglas F

    2014-08-15

    The failure of antiviral vaccines is often associated with rapid viral escape from specific immune responses. In the past, conserved epitope or algorithmic epitope selections, such as mosaic vaccines, have been designed to diversify immunity and to circumvent potential viral escape. An alternative approach is to identify conserved stable non-HIV-1 self-epitopes present exclusively in HIV-1-infected cells. We showed previously that human endogenous retroviral (HERV) mRNA transcripts and protein are found in cells of HIV-1-infected patients and that HERV-K (HML-2)-specific T cells can eliminate HIV-1-infected cells in vitro. In this article, we demonstrate that a human anti-HERV-K (HML-2) transmembrane protein Ab binds specifically to HIV-1-infected cells and eliminates them through an Ab-dependent cellular cytotoxicity mechanism in vitro. Thus, Abs directed against epitopes other than HIV-1 proteins may have a role in eliminating HIV-1-infected cells and could be targeted in novel vaccine approaches or immunotherapeutic modalities. PMID:25024383

  4. Murine cellular cytotoxicity to syngeneic and xenogeneic herpes simplex virus-infected cells.

    PubMed Central

    Kohl, S; Drath, D B; Loo, L S

    1982-01-01

    Cellular cytotoxicity of C57BL/6 adult mice peritoneal cells to xenogeneic (Chang liver) and syngeneic (BL/6-WT3) herpes simplex virus (HSV)-infected cells was analyzed in a 6-h 51Cr release assay. There was no difference in antibody-dependent cellular cytotoxicity to either target. There was no natural killer cytotoxicity to targets with cells from uninfected mice except at very high effector cell ratios. HSV-infected (2 X 10(4) PFU intraperitoneally 1 day previously) mice mediated significantly higher antibody-dependent cellular cytotoxicity and required less antibody (10(-5) versus 10(-2) dilution), fewer cells, and less time to kill than cells from uninfected mice. HSV-infected mice mediated natural killer cytotoxicity but preferentially killed syngeneic HSV-infected cells. Stimulation of cytotoxicity was not virus specific since influenza-infected mice mediated similar levels of cytotoxicity to HSV-infected targets. There was no difference in morphology (95% macrophage) or in the percentage of FcR-positive cells, but infected mice had more peritoneal cells and generated higher levels of superoxide in response to opsonized zymosan or phorbolmyristate acetate. These data demonstrate nonspecific virus-stimulated metabolic and effector cell function which may enhance clearance of virus in an infected host. PMID:6295943

  5. Murine cellular cytotoxicity to syngeneic and xenogeneic herpes simplex virus-infected cells.

    PubMed

    Kohl, S; Drath, D B; Loo, L S

    1982-12-01

    Cellular cytotoxicity of C57BL/6 adult mice peritoneal cells to xenogeneic (Chang liver) and syngeneic (BL/6-WT3) herpes simplex virus (HSV)-infected cells was analyzed in a 6-h 51Cr release assay. There was no difference in antibody-dependent cellular cytotoxicity to either target. There was no natural killer cytotoxicity to targets with cells from uninfected mice except at very high effector cell ratios. HSV-infected (2 X 10(4) PFU intraperitoneally 1 day previously) mice mediated significantly higher antibody-dependent cellular cytotoxicity and required less antibody (10(-5) versus 10(-2) dilution), fewer cells, and less time to kill than cells from uninfected mice. HSV-infected mice mediated natural killer cytotoxicity but preferentially killed syngeneic HSV-infected cells. Stimulation of cytotoxicity was not virus specific since influenza-infected mice mediated similar levels of cytotoxicity to HSV-infected targets. There was no difference in morphology (95% macrophage) or in the percentage of FcR-positive cells, but infected mice had more peritoneal cells and generated higher levels of superoxide in response to opsonized zymosan or phorbolmyristate acetate. These data demonstrate nonspecific virus-stimulated metabolic and effector cell function which may enhance clearance of virus in an infected host. PMID:6295943

  6. Cytotoxicity of metal and semiconductor nanoparticles indicated by cellular micromotility.

    PubMed

    Tarantola, Marco; Schneider, David; Sunnick, Eva; Adam, Holger; Pierrat, Sebastien; Rosman, Christina; Breus, Vladimir; Sönnichsen, Carsten; Basché, Thomas; Wegener, Joachim; Janshoff, Andreas

    2009-01-27

    In the growing field of nanotechnology, there is an urgent need to sensitively determine the toxicity of nanoparticles since many technical and medical applications are based on controlled exposure to particles, that is, as contrast agents or for drug delivery. Before the in vivo implementation, in vitro cell experiments are required to achieve a detailed knowledge of toxicity and biodegradation as a function of the nanoparticles' physical and chemical properties. In this study, we show that the micromotility of animal cells as monitored by electrical cell-substrate impedance analysis (ECIS) is highly suitable to quantify in vitro cytotoxicity of semiconductor quantum dots and gold nanorods. The method is validated by conventional cytotoxicity testing and accompanied by fluorescence and dark-field microscopy to visualize changes in the cytoskeleton integrity and to determine the location of the particles within the cell. PMID:19206269

  7. Human antibody-dependent cellular cytotoxicity and natural killer cytotoxicity to herpes simplex virus-infected autologous and allogeneic cells.

    PubMed Central

    Kohl, S; Moore, C M

    1983-01-01

    Using cultured skin shavings, human cellular cytotoxicity to uninfected and herpes simplex virus (HSV)-infected autologous and allogeneic fibroblasts and Chang liver cells was analysed in a 51Cr release assay. The effector cell requirements and characterization, time kinetics and antibody requirements were similar using each HSV-infected target cell in an antibody-dependent cellular cytotoxicity (ADCC) system. There was lower natural killer cytotoxicity (NKC) to uninfected autologous cells than unrelated cells in an 18 hr assay. NKC to infected autologous and unrelated fibroblasts was similar to that mediated against Chang liver cells. Thus NKC to uninfected fibroblasts correlated with the relationship of effector and target cells while NKC to infected cells correlated with the intrinsic lytic potential of the effector cells. The autologous system offers little advantage in the analysis of ADCC or NKC in normal individuals to virus-infected cells, but is probably crucial for the detection of HLA-restricted T-cell cytotoxicity. The demonstration of autologous anti-viral ADCC and NKC lends further credence to the in vivo importance of the mechanisms. PMID:6848451

  8. The cellular mechanisms of neuronal swelling underlying cytotoxic edema.

    PubMed

    Rungta, Ravi L; Choi, Hyun B; Tyson, John R; Malik, Aqsa; Dissing-Olesen, Lasse; Lin, Paulo J C; Cain, Stuart M; Cullis, Pieter R; Snutch, Terrance P; MacVicar, Brian A

    2015-04-23

    Cytotoxic brain edema triggered by neuronal swelling is the chief cause of mortality following brain trauma and cerebral infarct. Using fluorescence lifetime imaging to analyze contributions of intracellular ionic changes in brain slices, we find that intense Na(+) entry triggers a secondary increase in intracellular Cl(-) that is required for neuronal swelling and death. Pharmacological and siRNA-mediated knockdown screening identified the ion exchanger SLC26A11 unexpectedly acting as a voltage-gated Cl(-) channel that is activated upon neuronal depolarization to membrane potentials lower than -20 mV. Blockade of SLC26A11 activity attenuates both neuronal swelling and cell death. Therefore cytotoxic neuronal edema occurs when sufficient Na(+) influx and depolarization is followed by Cl(-) entry via SLC26A11. The resultant NaCl accumulation causes subsequent neuronal swelling leading to neuronal death. These findings shed light on unique elements of volume control in excitable cells and lay the ground for the development of specific treatments for brain edema. PMID:25910210

  9. Cellular Targets and Mechanisms in the Cytotoxic Action of Non-biodegradable Engineered Nanoparticles

    PubMed Central

    Fröhlich, Eleonore

    2013-01-01

    The use of nanoparticles (NPs) has improved the quality of many industrial, pharmaceutical, and medical products. Increased surface reactivity, a major reason for the positive effects of NPs, may, on the other hand, also cause adverse biological effects. Almost all non-biodegradable NPs cause cytotoxic effects but employ quite different modes of action. The relation of biodegradable or loaded NPs to cytotoxic mechanism is more difficult to identify because effects may by caused by the particles or degradation products thereof. This review introduces problems of NPs in conventional cytotoxicity testing (changes of particle parameters in biological fluids, cellular dose, cell line and assay selection). Generation of reactive oxygen and nitrogen species by NPs and of metal ions due to dissolution of the NPs is discussed as a cause for cytotoxicity. The effects of NPs on plasma membrane, mitochondria, lysosomes, nucleus, and intracellular proteins as cellular targets for cytotoxicity are summarized. The comparison of the numerous studies on the mechanism of cellular effects shows that, although some common targets have been identified, other effects are unique for particular NPs or groups of NPs. While titanium dioxide NPs appear to act mainly by generation of reactive oxygen and nitrogen species, biological effects of silver and iron oxide are caused by both reactive species and free metal ions. NPs lacking heavy metals, such as carbon nanotubes and polystyrene particles, interfere with cell metabolism mainly by binding to macromolecules. PMID:24160294

  10. Cellular Uptake and Cytotoxicity of Drug-Peptide Conjugates Regulated by Conjugation Site

    PubMed Central

    Zhang, Pengcheng; Cheetham, Andrew G.; Lock, Lye Lin; Cui, Honggang

    2013-01-01

    Conjugation of anticancer drugs to hydrophilic peptides such as Tat is a widely adopted strategy to improve the drug’s solubility, cellular uptake and potency against cancerous cells. Here we report that attachment of an anticancer drug doxorubicin to the N- or C-terminal of the Tat peptide can have a significant impact on their cellular uptake, cytotoxicity against both drug-sensitive and drug-resistant cancer cells. We observed higher cellular uptake by both cell lines for C-terminal conjugate relative to the N-terminal analogue. Our results reveal that the C-terminal conjugate partially overcame the multi-drug resistance of cervical cancer cells, while the N-terminal conjugate showed no significant improvement in cytotoxicity when compared with free doxorubicin. We also found that both N- and C- conjugates offers a mechanism to circumvent drug efflux associated with multidrug resistance. PMID:23514455

  11. Evaluation of the cytotoxicity of cigarette smoke condensate by a cellular impedance biosensor.

    PubMed

    Chen, Huan; Cui, Lin; Jiang, Xing-Yi; Pang, Yong-Qiang; Tang, Gang-Ling; Hou, Hong-Wei; Jiang, Jian-Hui; Hu, Qing-Yuan

    2012-03-01

    In this study, a cytotoxicity assay was developed for profiling the cytotoxicity of cigarette smoke condensates (CSCs) base on a cellular impedance biosensor (CIB). Compared with the traditional in vitro cytotoxicity assays, this CIB-based method offered distinct advantages in real-time kinetic measurement which provided a comprehensive understanding of cellular responses for the entire duration of the experiment and prediction of the potential mechanism of action of a given treatment. The time-dependent cell response profiles provided valid evidences for optimization of cell number per well, cell quality control, and identification of the optimal time points for compound treatment and endpoint assays. According to the time dependent IC50 values, the CIB could provide dynamic information that can be used to identify maximum toxicity of cigarette smoke and reversibility of the toxic effects which are difficult to achieve by the endpoint assays. The comparative IC50 values indicated that the as-developed biosensor offered analytical results in good consistency with the commonly used NRU method. The features of the CIB-based cytotoxicity assay, such as no cell labeling, automatic detection, and easy operation, give this assay potential to become routine setting for evaluating the cytotoxicity of CSCs. PMID:22142689

  12. The marginating-pulmonary immune compartment in mice exhibits increased NK cytotoxicity and unique cellular characteristics.

    PubMed

    Benish, Marganit; Melamed, Rivka; Rosenne, Ella; Neeman, Elad; Sorski, Liat; Levi, Ben; Shaashua, Lee; Matzner, Pini; Ben-Eliyahu, Shamgar

    2014-01-01

    To test whether marginating-pulmonary (MP) leukocytes in mice have a unique potential to identify and destroy aberrant circulating cells, we compared MP to circulating leukocytes with respect to natural killer (NK) cytotoxicity, proinflammatory characteristics, molecular determinants of activation, and response to IL-12 immunostimulation. Cytotoxicity was assessed employing the YAC-1, B16F10, and 3LL target lines. C57BL/6 mice were injected with either saline or murine IL-12 (0.1 or 0.5 µg/mouse), either once or three times 48-h apart. Twenty-four hours after last injection, cardiac blood was withdrawn and MP leukocytes were collected by forced lung perfusion. NK cytotoxicity, cellular composition, and surface molecular markers were studied. MP leukocytes exhibited greater NK cytotoxicity than circulating leukocytes against the syngeneic B16F10 and 3LL tumor lines, but not against the allogeneic YAC-1 line. NKG2D and IL-12 receptor expression predicted NK cytotoxicity in circulating leukocytes, but not in MP leukocytes. IFNγ-receptor, IL-12-receptor, CD69, CD11a, and CD11b showed different patterns of expression in the two leukocyte populations, suggesting pro-inflammatory characteristics of the MP compartment. IL-12 stimulation caused differential effects on these markers and also elevated cytotoxicity in both compartments, but in different effector: target ratio-dependent patterns. MP leukocytes may play a critical role in eliminating aberrant circulating cells due to their enhanced NK cytotoxicity and given their strategic location in the lungs vasculature, which forces physical interactions with all circulating aberrant cells. MP-NK cells are unique in their cytotoxic mechanisms against syngeneic targets and in their activation profile and response to immunostimulatory agents. PMID:24132552

  13. Cellular uptake behaviour, photothermal therapy performance, and cytotoxicity of gold nanorods with various coatings

    NASA Astrophysics Data System (ADS)

    Zhu, Xiao-Ming; Fang, Caihong; Jia, Henglei; Huang, Yu; Cheng, Christopher H. K.; Ko, Chun-Hay; Chen, Zhiyi; Wang, Jianfang; Wang, Yi-Xiang J.

    2014-09-01

    With the development of Au nanorods for a number of biomedical applications, understanding their cellular responses has become increasingly important. In this study, we systematically evaluated the cellular uptake behaviour and cytotoxicity of Au nanorods with various surface coatings, including organic cetyltrimethylammonium bromide (CTAB), poly(sodium 4-styrenesulfonate) (PSS), and poly(ethylene glycol) (PEG), and inorganic mesoporous silica (mSiO2), dense silica (dSiO2), and titanium dioxide (TiO2). The cellular behaviour of Au nanorods was found to be highly dependent on both the surface coating and the cell type. CTAB-, PSS-, and mSiO2-coated Au nanorods exhibit notable cytotoxicity, while PEG-, dSiO2-, and TiO2-coated Au nanorods do not induce cell injury. Optical imaging studies indicated that the cell type plays a preferential role in Au nanorod cellular uptake. Higher cellular uptake of Au nanorods was seen in U-87 MG, PC-3, MDA-MB-231, and RAW 264.7 cells, as opposed to HepG2 and HT-29 cells. In addition, Au nanorod cellular uptake is also highly affected by serum protein binding to the surface coating. mSiO2-, dSiO2-, and TiO2-coated Au nanorods show significantly higher cellular uptake than PSS- and PEG-coated ones, which results in a better photothermal ablation effect for Au nanorods with the inorganic surface coatings. Our study provides valuable insights into the effects of the surface modification on the biocompatibility, cellular uptake, as well as biomedical functions of Au nanorods.With the development of Au nanorods for a number of biomedical applications, understanding their cellular responses has become increasingly important. In this study, we systematically evaluated the cellular uptake behaviour and cytotoxicity of Au nanorods with various surface coatings, including organic cetyltrimethylammonium bromide (CTAB), poly(sodium 4-styrenesulfonate) (PSS), and poly(ethylene glycol) (PEG), and inorganic mesoporous silica (mSiO2), dense silica (d

  14. Cellular distribution and cytotoxicity of graphene quantum dots with different functional groups

    PubMed Central

    2014-01-01

    Graphene quantum dots (GQDs) have been developed as promising optical probes for bioimaging due to their excellent photoluminescent properties. Additionally, the fluorescence spectrum and quantum yield of GQDs are highly dependent on the surface functional groups on the carbon sheets. However, the distribution and cytotoxicity of GQDs functionalized with different chemical groups have not been specifically investigated. Herein, the cytotoxicity of three kinds of GQDs with different modified groups (NH2, COOH, and CO-N (CH3)2, respectively) in human A549 lung carcinoma cells and human neural glioma C6 cells was investigated using thiazoyl blue colorimetric (MTT) assay and trypan blue assay. The cellular apoptosis or necrosis was then evaluated by flow cytometry analysis. It was demonstrated that the three modified GQDs showed good biocompatibility even when the concentration reached 200 μg/mL. The Raman spectra of cells treated with GQDs with different functional groups also showed no distinct changes, affording molecular level evidence for the biocompatibility of the three kinds of GQDs. The cellular distribution of the three modified GQDs was observed using a fluorescence microscope. The data revealed that GQDs randomly dispersed in the cytoplasm but not diffused into nucleus. Therefore, GQDs with different functional groups have low cytotoxicity and excellent biocompatibility regardless of chemical modification, offering good prospects for bioimaging and other biomedical applications. PMID:24597852

  15. The role of surface charge in cellular uptake and cytotoxicity of medical nanoparticles

    PubMed Central

    Fröhlich, Eleonore

    2012-01-01

    Many types of nanoparticles (NPs) are tested for use in medical products, particularly in imaging and gene and drug delivery. For these applications, cellular uptake is usually a prerequisite and is governed in addition to size by surface characteristics such as hydrophobicity and charge. Although positive charge appears to improve the efficacy of imaging, gene transfer, and drug delivery, a higher cytotoxicity of such constructs has been reported. This review summarizes findings on the role of surface charge on cytotoxicity in general, action on specific cellular targets, modes of toxic action, cellular uptake, and intracellular localization of NPs. Effects of serum and intercell type differences are addressed. Cationic NPs cause more pronounced disruption of plasma-membrane integrity, stronger mitochondrial and lysosomal damage, and a higher number of autophagosomes than anionic NPs. In general, nonphagocytic cells ingest cationic NPs to a higher extent, but charge density and hydrophobicity are equally important; phagocytic cells preferentially take up anionic NPs. Cells do not use different uptake routes for cationic and anionic NPs, but high uptake rates are usually linked to greater biological effects. The different uptake preferences of phagocytic and nonphagocytic cells for cationic and anionic NPs may influence the efficacy and selectivity of NPs for drug delivery and imaging. PMID:23144561

  16. Fc-optimized NKG2D-Fc constructs induce NK cell antibody-dependent cellular cytotoxicity against breast cancer cells independently of HER2/neu expression status.

    PubMed

    Raab, Stefanie; Steinbacher, Julia; Schmiedel, Benjamin J; Kousis, Philaretos C; Steinle, Alexander; Jung, Gundram; Grosse-Hovest, Ludger; Salih, Helmut R

    2014-10-15

    The ability of NK cells to mediate Ab-dependent cellular cytotoxicity (ADCC) largely contributes to the clinical success of antitumor Abs, including trastuzumab, which is approved for the treatment of breast cancer with HER2/neu overexpression. Notably, only ∼25% of breast cancer patients overexpress HER2/neu. Moreover, HER2/neu is expressed on healthy cells, and trastuzumab application is associated with side effects. In contrast, the ligands of the activating immunoreceptor NKG2D (NKG2DL) are selectively expressed on malignant cells. In this study, we took advantage of the tumor-associated expression of NKG2DL by using them as target Ags for NKG2D-IgG1 fusion proteins optimized by amino acid exchange S239D/I332E in their Fc part. Compared to constructs with wild-type Fc parts, fusion proteins carrying the S239D/I332E modification (NKG2D-Fc-ADCC) mediated highly enhanced degranulation, ADCC, and IFN-γ production of NK cells in response to breast cancer cells. NKG2D-Fc-ADCC substantially enhanced NK reactivity also against HER2/neu-low targets that were unaffected by trastuzumab, as both compounds mediated their immunostimulatory effects in strict dependence of target Ag expression levels. Thus, in line with the hierarchically organized potential of the various activating receptors governing NK reactivity and due to its highly increased affinity to CD16, NKG2D-Fc-ADCC potently enhances NK cell reactivity despite the inevitable reduction of activating signals upon binding to NKG2DL. Due to the tumor-restricted expression of NKG2DL, NKG2D-Fc-ADCC may constitute an attractive means for immunotherapy especially of HER2/neu-low or -negative breast cancer. PMID:25217158

  17. Health and Cellular Impacts of Air Pollutants: From Cytoprotection to Cytotoxicity

    PubMed Central

    Andreau, Karine; Leroux, Melanie; Bouharrour, Aida

    2012-01-01

    Air pollution as one of the ravages of our modern societies is primarily linked to urban centers, industrial activities, or road traffic. These atmospheric pollutants have been incriminated in deleterious health effects by numerous epidemiological and in vitro studies. Environmental air pollutants are a heterogeneous mixture of particles suspended into a liquid and gaseous phase which trigger the disruption of redox homeostasis—known under the term of cellular oxidative stress—in relation with the establishment of inflammation and cell death via necrosis, apoptosis, or autophagy. Activation or repression of the apoptotic process as an adaptative response to xenobiotics might lead to either acute or chronic toxicity. The purpose of this paper is to highlight the central role of oxidative stress induced by air pollutants and to focus on the subsequent cellular impacts ranging from cytoprotection to cytotoxicity by decreasing or stimulating apoptosis, respectively. PMID:22550588

  18. Silicon dioxide nanoparticles increase macrophage atherogenicity: Stimulation of cellular cytotoxicity, oxidative stress, and triglycerides accumulation.

    PubMed

    Petrick, Lauren; Rosenblat, Mira; Paland, Nicole; Aviram, Michael

    2016-06-01

    Nanoparticle research has focused on their toxicity in general, while increasing evidence points to additional specific adverse effects on atherosclerosis development. Arterial macrophage cholesterol and triglyceride (TG) accumulation and foam cell formation are the hallmark of early atherogenesis, leading to cardiovascular events. To investigate the in vitro atherogenic effects of silicon dioxide (SiO2 ), J774.1 cultured macrophages (murine cell line) were incubated with SiO2 nanoparticle (SP, d = 12 nm, 0-20 µg/mL), followed by cellular cytotoxicity, oxidative stress, TG and cholesterol metabolism analyses. A significant dose-dependent increase in oxidative stress (up to 164%), in cytotoxicity (up to 390% measured by lactate dehydrogenase (LDH) release), and in TG content (up to 63%) was observed in SiO2 exposed macrophages compared with control cells. A smaller increase in macrophage cholesterol mass (up to 22%) was noted. TG accumulation in macrophages was not due to a decrease in TG cell secretion or to an increased TG biosynthesis rate, but was the result of attenuated TG hydrolysis secondary to decreased lipase activity and both adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL) protein expression (by 42 and 25%, respectively). Overall, SPs showed pro-atherogenic effects on macrophages as observed by cytotoxicity, increased oxidative stress and TG accumulation. © 2014 Wiley Periodicals, Inc. Environ Toxicol 31: 713-723, 2016. PMID:25448404

  19. Verapamil potentiation of melphalan cytotoxicity and cellular uptake in murine fibrosarcoma and bone marrow.

    PubMed Central

    Robinson, B. A.; Clutterbuck, R. D.; Millar, J. L.; McElwain, T. J.

    1985-01-01

    Growth delay by melphalan of two fibrosarcomas in CBA mice was prolonged by intraperitoneal (i.p.) verapamil, 10 mg kg-1. Verapamil also increased the area under the blood concentration time curve and the gastrointestinal toxicity of melphalan. Verapamil promoted melphalan cytotoxicity to murine bone marrow both in vivo, by CFU-S assay, and in vitro, by CFU-GM assay. In 1 microgram ml-1 [14C]-melphalan, verapamil (10 micrograms ml-1) increased by 1.5 times the [14C]-melphalan accumulation by murine bone marrow, reversibly and independently of external calcium. Efflux of [14C]-melphalan from murine bone marrow was retarded by verapamil. Verapamil increased [14C]-melphalan uptake by disaggregated fibrosarcoma cells but had no effect on melphalan accumulation and cytotoxicity in human bone marrow. Although verapamil affected melphalan pharmacokinetics, enhancement of cellular melphalan uptake by verapamil in murine fibrosarcoma and bone marrow appeared to account for much of the increase in melphalan cytotoxicity. The lack of potentiation of melphalan by verapamil in human marrow suggests differences in melphalan transport or in verapamil membrane interactions in mouse and man. PMID:4074636

  20. Enhanced cellular uptake and cytotoxicity of folate decorated doxorubicin loaded PLA-TPGS nanoparticles

    NASA Astrophysics Data System (ADS)

    Nguyen, Hoai Nam; Nhung Hoang, Thi My; Thu Trang Mai, Thi; Quynh Trang Nguyen, Thi; Doan Do, Hai; Hien Pham, Thi; Lap Nguyen, Thi; Thu Ha, Phuong

    2015-01-01

    Doxorubicin (DOX) is one of the most effective anticancer drugs for treating many types of cancer. However, the clinical applications of DOX were hindered because of serious side-effects resulting from the unselective delivery to cancer cell including congestive heart failure, chronic cardiomyopathy and drug resistance. Recently, it has been demonstrated that loading anti-cancer drugs onto drug delivery nanosystems helps to maximize therapeutic efficiency and minimize unwanted side-effects via passive and active targeting mechanisms. In this study we prepared folate decorated DOX loaded PLA-TPGS nanoparticles with the aim of improving the potential as well as reducing the side-effects of DOX. Characteristics of nanoparticles were investigated by field emission scanning electron microscopy (FESEM), dynamic light scattering (DLS) method and Fourier transform infrared spectroscopy (FTIR). Anticancer activity of the nanoparticles was evaluated through cytotoxicity and cellular uptake assays on HeLa and HT29 cancer cell lines. The results showed that prepared drug delivery system had size around 100 nm and exhibited higher cytotoxicity and cellular uptake on both tested HeLa and HT29 cells.

  1. Unambiguous Identification of β-Tubulin as the Direct Cellular Target Responsible for the Cytotoxicity of Chalcone by Photoaffinity Labeling.

    PubMed

    Zhou, Bo; Yu, Xingxin; Zhuang, Chunlin; Villalta, Peter; Lin, Yong; Lu, Junxuan; Xing, Chengguo

    2016-07-01

    Chalcone is a simple and potentially privileged structure in medicinal chemistry with a diverse repertoire of biological activities, among which cytotoxicity is of particular interest. The sharp structure-activity relationship (SAR) for chalcone's cytotoxicity suggests structure-specific target interactions. Despite the numerous putative targets proposed, evidence for direct target interactions in cells is unavailable. In this study, guided by the sharp cytotoxic SAR, we developed a cytotoxic chalcone-based photoaffinity labeling (PAL) probe, (E)-3-(3-azidophenyl)-1-[3,5-dimethoxy-4-(prop-2-yn-1-yloxy)phenyl]-2-methylprop-2-en-1-one (C95; IC50 : 0.38±0.01 μm), along with two structurally similar non-cytotoxic probes. These probes were used to search for the direct cellular target responsible for chalcone's cytotoxicity through intact cell-based PAL experiments, in which β-tubulin was identified to specifically interact with the cytotoxic probe (i.e., C95) but not the non-cytotoxic probes. A set of phenotypical and biochemical assays further reinforced β-tubulin as the cytotoxic target of chalcones. Peptide mass quantitation by mass spectrometric analysis revealed one peptide potentially labeled by C95, providing information on chalcone's binding site on β-tubulin. PMID:27203512

  2. An integrated cellular model to evaluate cytotoxic effects in mammalian cell lines.

    PubMed

    Fernández Freire, P; Peropadre, A; Pérez Martín, J M; Herrero, O; Hazen, M J

    2009-12-01

    The ever growing anthropogenic pressure to the environment has lead in 2007 to the revision of the existing legislation and the approval of the new European law regarding the production and importation of chemicals, known as REACH. This new legal framework supports the development of alternative methods to animal experimentation encouraging the improvement and/or design of new methodological strategies for the toxicological evaluation of chemical compounds. Even though cytotoxicity studies are a reductionist approach to acute toxicity in vivo, they offer the best agreement between obtaining relevant information about the mechanism of toxic action and the use of alternative methods. Following this trend, this work presents an integrated cellular strategy in order to know the toxicity and mechanism of action of chemical compounds, using simple and reproducible in vitro systems. The experimental procedures are performed in two steps. The first one involves the systematic analysis of the main cellular targets using proliferation, viability and morphological probes. The second step relies upon the results obtained in the first step, including specific assays that focus on the mechanism of toxic action and the cellular response. The benefits of this strategy are exemplified with two real cases: pentachlorophenol and rotenone. PMID:19540333

  3. Monitoring cellular uptake and cytotoxicity of copper(II) complex using a fluorescent anthracene thiosemicarbazone ligand.

    PubMed

    Kate, Anup N; Kumbhar, Anupa A; Khan, Ayesha A; Joshi, Pranaya V; Puranik, Vedavati G

    2014-01-15

    The thiosemicarbazone derivative of anthracene (ATSC, anthracene thiosemicarbazone 1) and its copper(II) complex (CuATSC, 2) were synthesized and characterized by spectroscopic, electrochemical, and crystallographic techniques. Interaction of 1 and 2 with calf thymus (CT) DNA was explored using absorption and emission spectral methods, and viscosity measurements reveal a partial-intercalation binding mode. Their protein binding ability was monitored by the quenching of tryptophan emission using bovine serum albumin (BSA) as a model protein. Furthermore, their cellular uptake, in vitro cytotoxicity testing on the HeLa cell line, and flow cytometric analysis were carried out to ascertain the mode of cell death. Cell cycle analysis indicated that 1 and 2 cause cell cycle arrest in sub-G1 phase. PMID:24328322

  4. Physical exercise increases natural cellular-mediated tumor cytotoxicity in elderly women.

    PubMed

    Crist, D M; Mackinnon, L T; Thompson, R F; Atterbom, H A; Egan, P A

    1989-01-01

    The influence of acute treadmill exercise on natural killer (NK) cell tumor cytotoxicity in vitro was studied in elderly women after participation in a program of physical exercise training (PET) (n = 7) or after participation in a paralleling nonexercise control (NEC) condition (n = 7). The two study groups were equated (p greater than 0.05) according to age, percent total body fat, functional status as measured by multi-inventory ranking, and exercise capacity. After the experimental period, the PET subjects had a greater basal level of NK activity than the NEC subjects (PET 38.2 percent specific lysis, %SL, vs. NEC 28.8 %SL; p less than 0.05). Both groups experienced an increase in NK activity after acute treadmill exercise (PET 38.2-57.4 %SL, p less than 0.01; NEC 28.8-37.8 %SL, p less than 0.05), but the increase in the PET subjects was significantly (p less than 0.05) greater than that observed in the NEC subjects. We conclude that natural cellular-mediated tumor cytotoxicity is increased in response to acute exercise and long-term PET in elderly women. PMID:2792786

  5. Cellular Uptake and Cytotoxicity of β-Lactoglobulin Nanoparticles: The Effects of Particle Size and Surface Charge

    PubMed Central

    Ha, Ho-Kyung; Kim, Jin Wook; Lee, Mee-Ryung; Jun, Woojin; Lee, Won-Jae

    2015-01-01

    It is necessary to understand the cellular uptake and cytotoxicity of food-grade delivery systems, such as β-lactoglobulin (β-lg) nanoparticles, for the application of bioactive compounds to functional foods. The objectives of this study were to investigate the relationships between the physicochemical properties of β-lg nanoparticles, such as particle size and zeta-potential value, and their cellular uptakes and cytotoxicity in Caco-2 cells. Physicochemical properties of β-lg nanoparticles were evaluated using particle size analyzer. Flow cytometry and confocal laser scanning microscopy were used to investigate cellular uptake and cytotoxicity of β-lg nanoparticles. The β-lg nanoparticles with various particle sizes (98 to 192 nm) and zeta-potential values (−14.8 to −17.6 mV) were successfully formed. A decrease in heating temperature from 70°C to 60°C resulted in a decrease in the particle size and an increase in the zeta-potential value of β-lg nanoparticles. Non-cytotoxicity was observed in Caco-2 cells treated with β-lg nanoparticles. There was an increase in cellular uptake of β-lg nanoparticles with a decrease in particle size and an increase in zeta-potential value. Cellular uptake β-lg nanoparticles was negatively correlated with particle size and positively correlated with zeta-potential value. Therefore, these results suggest that the particle size and zeta-potential value of β-lg nanoparticles play an important role in the cellular uptake. The β-lg nanoparticles can be used as a delivery system in foods due to its high cellular uptake and non-cytotoxicity. PMID:25656189

  6. Photorelease and Cellular Delivery of Mitocurcumin from Its Cytotoxic Cobalt(III) Complex in Visible Light.

    PubMed

    Garai, Aditya; Pant, Ila; Banerjee, Samya; Banik, Bhabatosh; Kondaiah, Paturu; Chakravarty, Akhil R

    2016-06-20

    Ternary cobalt(III) complexes of curcumin (Hcur) and mitocurcumin [Hmitocur, a dicationic bis(triphenylphosphonium) derivative of curcumin] having a tetradentate phenolate-based ligand (H2L), namely, [Co(cur)(L)] (1) and [Co(mitocur)(L)]Cl2 (2), were prepared and structurally characterized, and their photoinduced cytotoxicity was studied. The diamagnetic cobalt(III) complexes show an irreversible Co(III)-Co(II) redox response and a quasireversible curcuminoid-based reduction near -1.45 and -1.74 V SCE, respectively, in DMF/0.1 M [(n)Bu4N](ClO4). The complexes exhibit a curcumin/mitocurcumin-based absorption band near 420 nm. Complex 1 was structurally characterized by X-ray crystallography. The structure contains the metal in a CoN2O4 distorted octahedral coordination arrangement with curcumin binding to the metal in its enolic form. Binding to cobalt(III) increases the hydrolytic stability of curcumin. Complex 2, having a dicationic curcuminoid, shows significant cellular uptake and photoinduced cytotoxicity compared to its curcumin analogue 1. The dicationic cobalt(III) complex 2 has significantly better cellular uptake and bioactivity than the neutral species 1. Complex 2 with mitochondrial localization releases the mitocurcumin dye upon exposure to visible light (400-700 nm) in human breast cancer MCF-7 cells through photoreduction of cobalt(III) to cobalt(II). Complex 2 displays a remarkable photodynamic therapy (PDT) effect, giving an IC50 value of ∼3.9 μM in visible light (400-700 nm) in MCF-7 cells while being much less toxic in the dark (>50 μM). The released mitocurcumin acts as a phototoxin, generating intracellular reactive oxygen species (ROSs). The overall process leads to light-controlled delivery of a curcuminoid (mitocur) into the tumor cells while the dye alone suffers from hydrolytic instability and poor bioavailability. PMID:27244480

  7. Luminescent pentafluorophenyl-cycloplatinated complexes: synthesis, characterization, photophysics, cytotoxicity and cellular imaging.

    PubMed

    Berenguer, J R; Pichel, J G; Giménez, N; Lalinde, E; Moreno, M T; Piñeiro-Hermida, S

    2015-11-21

    Luminescent mono(pentafluorophenyl) cycloplatinated complexes [Pt(C^N-κC,N)(HC^N-κN)(C6F5)] [HC^N = Hthpy (2-(2-thienyl)pyridine) 2a, Hbt (2-phenylbenzothiazole) 2b, Hpq (2-phenylquinoline) 2c] have been prepared by C–H activation of a HC^N ligand in the corresponding [Pt(HC^N-κN)2(C6F5)2] (1a, 1b, 1c) complexes. Complexes 2 evolve in DMSO solution into solvate complexes and we present here successful routes for the synthesis of [Pt(C^N)(C6F5)(DMSO)] (C^N = thpy 3a, bt 3b). They have been fully characterized (X-ray for 1a, 1c, 2b, 3a and 3b), their electronic absorption and emission properties have been investigated and DFT and TD-DFT calculations for 1a, 1c, 2b and 3a have been carried out. Complexes 3a, 3b and [Pt(ppy)(C6F5)(DMSO)] 4 (Hppy = 2-phenylpyridine) show remarkable stability in a mixed DMSO-cellular medium and their cytotoxicity towards the human lung tumor (A549) and bronchial epithelial non-tumorigenic (NL20) cell lines has been evaluated by MTS assays. Their cellular localization in A549 and NL20 human cells and in mouse embryonic fibroblasts obtained from lungs (LMEFs) has also been investigated by fluorescence microscopy. PMID:26462143

  8. New water-soluble ruthenium(II) cytotoxic complex: biological activity and cellular distribution.

    PubMed

    Morais, Tânia S; Santos, Filipa C; Jorge, Tiago F; Côrte-Real, Leonor; Madeira, Paulo J Amorim; Marques, Fernanda; Robalo, M Paula; Matos, António; Santos, Isabel; Garcia, M Helena

    2014-01-01

    A novel water soluble organometallic compound, [RuCp(mTPPMSNa)(2,2'-bipy)][CF3SO3] (TM85, where Cp=η(5)-cyclopentadienyl, mTPPMS=diphenylphosphane-benzene-3-sulfonate and 2,2'-bipy=2,2'-bipyridine) is presented herein. Studies of interactions with relevant proteins were performed to understand the behavior and mode of action of this complex in the biological environment. Electrochemical and fluorescence studies showed that TM85 strongly binds to albumin. Studies carried out to study the formation of TM85 which adducts with ubiquitin and cytochrome c were performed by electrospray ionization mass spectrometry (ESI-MS). Antitumor activity was evaluated against a variety of human cancer cell lines, namely A2780, A2780cisR, MCF7, MDAMB231, HT29, PC3 and V79 non-tumorigenic cells and compared with the reference drug cisplatin. TM85 cytotoxic effect was reduced in the presence of endocytosis modulators at low temperatures, suggesting an energy-dependent mechanism consistent with endocytosis. Ultrastructural analysis by transmission electron microscopy (TEM) revealed that TM85 targets the endomembranar system disrupting the Golgi and also affects the mitochondria. Disruption of plasma membrane observed by flow cytometry could lead to cellular damage and cell death. On the whole, the biological activity evaluated herein combined with the water solubility property suggests that complex TM85 could be a promising anticancer agent. PMID:24145065

  9. Fc-galactosylation modulates antibody-dependent cellular cytotoxicity of therapeutic antibodies.

    PubMed

    Thomann, Marco; Reckermann, Katharina; Reusch, Dietmar; Prasser, Jessica; Tejada, Max L

    2016-05-01

    The therapeutic activity of monoclonal antibodies can involve immune cell mediated effector functions including antibody-dependent cellular cytotoxicity (ADCC), an activity that is modulated by the structure of Fc-glycans, and in particular the lack of core fucose. The heterogeneity of these glycostructures and the inherent variability of traditional PBMC-based in vitro ADCC assays, have made it challenging to quantitatively assess the impact of other glycostructures on ADCC activity. We applied a quantitative NK cell based assay to generate a database consisting of Fc-glycostructure and ADCC data from 54 manufacturing batches of a CHO-derived monoclonal antibody. Explorative analysis of the data indicated that, apart from afucosylation, galactosylation levels could influence ADCC activity. We confirmed this hypothesis by demonstrating enhanced ADCC upon enzymatic hypergalactosylation of four different monoclonal antibodies derived using standard CHO manufacturing processes. Furthermore we quantitatively compare the effects of galactosylation and afucosylation in the context of glycan heterogeneity and demonstrate that while galactose can influence ADCC activity, afucosylation remains the primary driver of this activity. PMID:27058641

  10. Compromised NK Cell-Mediated Antibody-Dependent Cellular Cytotoxicity in Chronic SIV/SHIV Infection

    PubMed Central

    He, Xuan; Li, Dan; Luo, Zhenwu; Liang, Hua; Peng, Hong; Zhao, Yangyang; Wang, Nidan; Liu, Donghua; Qin, Chuan; Wei, Qiang; Yan, Huimin; Shao, Yiming

    2013-01-01

    Increasing evidence indicates that antibody-dependent cellular cytotoxicity (ADCC) contributes to the control of HIV/SIV infection. However, little is known about the ADCC function of natural killer (NK) cells in non-human primate model. Here we demonstrated that ADCC function of NK cells was significantly compromised in chronic SIV/SHIV infection, correlating closely with the expression of FcγRIIIa receptor (CD16) on NK cells. CD32, another class of IgG Fc receptors, was identified on NK cells with higher expression in the infected macaques and the blockade of CD32 impacted the ability of NK cells to respond to antibody-coated target cells. The inhibition of matrix metalloproteases (MMPs), a group of enzymes normally involved in tissue/receptor remodeling, could restore NK cell-mediated ADCC with increased CD16 expression on macaque NK cells. These data offer a clearer understanding of NK cell-mediated ADCC in rhesus macaques, which will allow us to evaluate the ADCC repertoire arising from preclinical vaccination studies in non-human primates and inform us in the future design of effective HIV vaccination strategies. PMID:23424655

  11. An improved assay for antibody dependent cellular cytotoxicity based on time resolved fluorometry.

    PubMed

    Patel, A K; Boyd, P N

    1995-07-17

    A new and faster assay for antibody dependent cellular cytotoxicity based on release of europium from target cells is described. This has a number of important advantages over the traditional assays based on release of chromium-51 (51Cr). The new method involves labelling of Wein 133 target cells (B cell non-Hodgkin's lymphoma cells) which express the antigen, CDw52, with the chelate europium diethylenetriaminopentaacetic acid (EuDTPA) according to the method of Blomberg et al. (1986). Labelled cells are sensitised (coated) with the anti-lymphocytic monoclonal antibody, Campath-1H. Human peripheral blood mononuclear cells are added to mediate lysis of EuDTPA labelled Wein 133 cells by ADCC. Release of EuDTPA from lysed cells is determined by mixing supernatants with enhancement solution containing 2-naphthoyl trifluoroacetone, 2-NTA, to form a highly fluorescent chelate which is measured using time resolved fluorometry. Results obtained with the new EuDPTA release assays were comparable to traditional assays based on the release of the radioisotope 51Cr. It is anticipated that this assay will have a widespread application among laboratories performing ADCC assays. The method is non-hazardous and has been used routinely for over 2 years to monitor production and purification of Campath-1H. PMID:7622867

  12. Systemic induction of cells mediating antibody-dependent cellular cytotoxicity following administration of interleukin 2.

    PubMed

    Eisenthal, A; Rosenberg, S A

    1989-12-15

    We have previously demonstrated that incubation of murine cells in vitro in interleukin 2 (IL-2) induced antibody-dependent cellular cytotoxicity (ADCC) and that these cells were derived from the NK/LAK, FcR+ cell population. In the present study we show that in vivo administration of IL-2 to mice induces cells which exhibit ADCC activity in the peritoneal cavity, liver, lungs, and to a lesser degree in the bone marrow, spleen, mesenteric lymph nodes, and thymus. A gradual increase in ADCC activity and the number of Fc-receptor-positive cells was seen 1 to 3 days after starting IL-2 treatment. The cells mediating ADCC are closely related to LAK cells since they expressed Thy1.2 antigens and are derived from asialo GM1-positive, Lyt2/L3T4-negative, radiosensitive cells. These results demonstrate that IL-2 can systemically induce cells with ADCC activity and that this ability may be useful in the establishment of therapeutic models against disseminated cancer when combined with specific antitumor monoclonal antibodies. PMID:2573425

  13. c-Abl Modulates Tumor Cell Sensitivity to Antibody-Dependent Cellular Cytotoxicity (ADCC)

    PubMed Central

    Murray, Joseph C.; Aldeghaither, Dalal; Wang, Shangzi; Nasto, Rochelle E.; Jablonski, Sandra A.; Tang, Yong; Weiner, Louis M.

    2014-01-01

    Monoclonal antibodies can modulate cancer cell signal transduction and recruit antitumor immune effector mechanisms – including antibody-dependent cellular cytotoxicity (ADCC). Although several clinically effective antibodies can promote ADCC, therapeutic resistance is common. We hypothesized that oncogenic signaling networks within tumor cells affect their sensitivity to ADCC. We developed a screening platform and targeted 60 genes derived from an EGFR gene network using RNA interference (RNAi) in an in vitro ADCC model system. Knockdown of GRB7, PRKCE, and ABL1 enhanced ADCC by primary and secondary screens. ABL1 knockdown also reduced cell proliferation, independent of its ADCC enhancement effects. c-Abl overexpression decreased ADCC sensitivity and rescued the effects of ABL1 knockdown. Imatinib inhibition of c-Abl kinase activity also enhanced ADCC – phenocopying ABL1 knockdown – against several EGFR-expressing head-and-neck squamous cell carcinoma (HNSCC) cell lines by ex vivo primary NK cells. Our findings suggest that combining c-Abl inhibition with ADCC-promoting antibodies, such as cetuximab, could translate into increased therapeutic efficacy of monoclonal antibodies. PMID:25300860

  14. Epitope specificity of human immunodeficiency virus-1 antibody dependent cellular cytotoxicity [ADCC] responses.

    PubMed

    Pollara, Justin; Bonsignori, Mattia; Moody, M Anthony; Pazgier, Marzena; Haynes, Barton F; Ferrari, Guido

    2013-07-01

    Antibody dependent cellular cytotoxicity [ADCC] has been suggested to play an important role in control of Human Immunodeficiency Virus-1 [HIV-1] viral load and protection from infection. ADCC antibody responses have been mapped to multiple linear and conformational epitopes within the HIV-1 envelope glycoproteins gp120 and gp41. Many epitopes targeted by antibodies that mediate ADCC overlap with those recognized by antibodies capable of virus neutralization. In addition, recent studies conducted with human monoclonal antibodies derived from HIV-1 infected individuals and HIV-1 vaccine-candidate vaccinees have identified a number of antibodies that lack the ability to capture primary HIV-1 isolates or mediate neutralizing activity, but are able to bind to the surface of infected CD4+ T cells and mediate ADCC. Of note, the conformational changes in the gp120 that may not exclusively relate to binding of the CD4 molecule are important in exposing epitopes recognized by ADCC responses. Here we discuss the HIV-1 envelope epitopes targeted by ADCC antibodies in the context of the potential protective capacities of ADCC. PMID:24191939

  15. Natural killer cell cytotoxicity of breast cancer targets is enhanced by two distinct mechanisms of antibody-dependent cellular cytotoxicity against LFA-3 and HER2/neu.

    PubMed

    Cooley, S; Burns, L J; Repka, T; Miller, J S

    1999-10-01

    Treatment of advanced breast cancer with autologous stem cell transplantation is limited by a high probability of disease relapse. In clinical trials, interleukin 2 (IL-2) alone can expand natural killer (NK) cells in vivo and increase their cytotoxic activity against breast cancer cell lines, but this increase is modest. Understanding the mechanisms that mediate NK cell lysis of breast cancer targets may lead to improvements of current immunotherapy strategies. NK cells from normal donors or patients receiving subcutaneous IL-2 were tested in cytotoxicity assays against five breast cancer cell lines. The role of adhesion molecules and antibodies that interact through Fc receptors on NK cells was explored. NK cell lysis of breast cancer targets is variable and is partially dependent on recognition through ICAM-1 and CD18. While blocking CD2 slightly decreased cytotoxicity, contrary to expectations, an antibody against CD58 (the ligand for CD2), failed to block killing and instead mediated an increased cytotoxicity that correlated with target density of CD58. The CD58 antibody-enhanced killing was dependent not only on FcRgammaIII but also on CD2 and ICAM-1/CD18. To further elucidate the mechanism of this CD58 antibody-dependent cellular cytotoxicity (ADCC), another antibody was tested. Trastuzumab (Herceptin), a humanized antibody against HER2/neu, mediated potent ADCC against all the HER2/neu positive breast cancer targets. Unlike CD58 antibody-mediated ADCC, Herceptin ADCC was minimally affected by blocking antibodies to CD2 or ICAM-1/CD18, which suggests a different mechanism of action. This study shows that multiple mechanisms are involved in NK cell lysis of breast cancer targets, that none of the targets are inherently resistant to killing, and that two distinct mechanisms of ADCC can target immunotherapy to breast cancer cells. PMID:10517495

  16. Redirected cellular cytotoxicity by infection of effector cells with a recombinant vaccinia virus encoding a tumor-specific monoclonal antibody.

    PubMed

    Paul, S; Bizouarne, N; Dott, K; Ruet, L; Dufour, P; Acres, R B; Kieny, M P

    2000-04-01

    Cytotoxicity is an important function of the immune system that results in the destruction of cellular targets by humoral and/or cellular mechanisms. We wanted to assess the possibility of targeting the lytic function of immune cells toward cancer cells, which express the gene coding for a known tumor antigen (Ag) (GA733-2/epithelial cell adhesion molecule), using a viral vector encoding a monoclonal antibody (mAb) specific for said tumor Ag (CO17-1A). To this end, we have constructed recombinant vaccinia viruses expressing the sequences corresponding to mAb CO17-1A, which recognizes a specific Ag (GA733-2) that is present on the surface of most gastrointestinal carcinomas. The recombinant vectors encoding either a secreted or membrane-anchored form of CO17-1A mAb were used to infect effector cells, which were subsequently assessed for their cytotoxic activity. The recombinant viruses were able to infect both granulocyte-macrophage colony-stimulating factor-activated human macrophages and Ag-stimulated murine cytotoxic T lymphocytes. Infected granulocyte-macrophage colony-stimulating factor-activated macrophages were found to be able to kill GA733-2-expressing tumor cells. Likewise, infected cytotoxic T lymphocytes, although conserving their original alloreactivity, gained the capability of killing GA733-2-expressing cancer cells. PMID:10811480

  17. Cellular uptake and cytotoxic potential of respirable bentonite particles with different quartz contents and chemical modifications in human lung fibroblasts.

    PubMed

    Geh, Stefan; Yücel, Raif; Duffin, Rodger; Albrecht, Catrin; Borm, Paul J A; Armbruster, Lorenz; Raulf-Heimsoth, Monika; Brüning, Thomas; Hoffmann, Eik; Rettenmeier, Albert W; Dopp, Elke

    2006-02-01

    Considering the biological reactivity of pure quartz in lung cells, there is a strong interest to clarify the cellular effects of respirable siliceous dusts, like bentonites. In the present study, we investigated the cellular uptake and the cytotoxic potential of bentonite particles (Ø< 10 microm) with an alpha-quartz content of up to 6% and different chemical modifications (activation: alkaline, acidic, organic) in human lung fibroblasts (IMR90). Additionally, the ability of the particles to induce apoptosis in IMR90-cells and the hemolytic activity was tested. All bentonite samples were tested for endotoxins with the in vitro-Pyrogen test and were found to be negative. Cellular uptake of particles by IMR90-cells was studied by transmission electron microscopy (TEM). Cytotoxicity was analyzed in IMR90-cells by determination of viable cells using flow cytometry and by measuring of the cell respiratory activity. Induced apoptotic cells were detected by AnnexinV/Propidiumiodide-staining and gel electrophoresis. Our results demonstrate that activated bentonite particles are better taken up by IMR90-cells than untreated (native) bentonite particles. Also, activated bentonite particles with a quartz content of 5-6% were more cytotoxic than untreated bentonites or bentonites with a quartz content lower than 4%. The bentonite samples induced necrotic as well as apoptotic cell death. In general, bentonites showed a high membrane-damaging potential shown as hemolytic activity in human erythrocytes. We conclude that cellular effects of bentonite particles in human lung cells are enhanced after chemical treatment of the particles. The cytotoxic potential of the different bentonites is primarily characterized by a strong lysis of the cell membrane. PMID:16059726

  18. Pharmacological Modulation of Cytotoxicity and Cellular Uptake of Anti-cancer Drugs by PDE5 Inhibitors in Lung Cancer Cells

    PubMed Central

    LI, QING; SHU, YAN

    2013-01-01

    Purpose Previous research has led to the recognition of a cGMP signaling pathway governing drug transport. This study is to investigate whether inhibitors of phosphodiesterase type 5 (PDE5), which increase intracellular cGMP levels, modulate the cytotoxicity and uptake of anti-cancer drugs in cancer cells. Methods The experiments were conducted with and without PDE5 inhibitors: dipyridamole, vardenafil, and/or sildenafil. The cytotoxicity of doxorubicin, cisplatin and oxaliplatin was determined in multiple cancer cell lines derived from different tissues. The cellular uptake of structurally diverse compounds was further examined in lung cancer cells with and without various endocytotic inhibitors. The tumor accumulation and the anti-tumor effect of trastuzumab were examined in a lung cancer xenograft mouse model. Results Dipyridamole could modulate the cytotoxicity of doxorubicin, cisplatin, and oxaliplatin in cancer cells. Particularly, PDE5 inhibitors increased cellular uptake of structurally diverse compounds into lung cancer cells both in vitro and in vivo. The effect of vardenafil on drug uptake could be blocked by endocytotic inhibitors. The growth of lung cancer xenograft in nude mice was significantly suppressed by addition of vardenafil to trastuzumab treatment. Conclusion PDE5 inhibitors may increase the efficacy of anti-cancer drugs by increasing endocytosis-mediated cellular drug uptake, and thus serve as adjuvant therapy for certain cancers such as lung cancer. PMID:23884568

  19. Systematic adjustment of charge densities and size of polyglycerol amines reduces cytotoxic effects and enhances cellular uptake.

    PubMed

    Hellmund, Markus; Achazi, Katharina; Neumann, Falko; Thota, Bala N S; Ma, Nan; Haag, Rainer

    2015-11-01

    Excessive cationic charge density of polyplexes during cellular uptake is still a major hurdle in the field of non-viral gene delivery. The most efficient cationic vectors such as polyethylene imine (PEI) or polyamidoamine (PAMAM) can be highly toxic and may induce strong side effects due to their high cationic charge densities. Alternatives like polyethylene glycol (PEG) are used to 'shield' these charges and thus to reduce the cytotoxic effects known for PEI/PEG-core-shell architectures. In this study, we compared the ability of hyperbranched polyglycerol amines (hPG amines) with different amine densities and molecular weights as non-viral cationic vectors for DNA delivery. By adjusting the hydroxyl to amine group ratio on varying molecular weights, we were able to perform a systematic study on the cytotoxic effects caused by the effective charge density in correlation to size. We could demonstrate that carriers with moderate charge density have a higher potential for effective DNA delivery as compared to high/low charged ones independent of their size, but the final efficiency can be optimized by the molecular weight. We analyzed the physicochemical properties and cellular uptake capacity as well as the cytotoxicity and transfection efficiency of these new vector systems. PMID:26244171

  20. Different cellular response mechanisms contribute to the length-dependent cytotoxicity of multi-walled carbon nanotubes.

    PubMed

    Liu, Dun; Wang, Lijun; Wang, Zhigang; Cuschieri, Alfred

    2012-01-01

    To date, there has not been an agreement on the best methods for the characterisation of multi-walled carbon nanotube (MWCNT) toxicity. The length of MWCNTs has been identified as a factor in in vitro and in vivo studies, in addition to their purity and biocompatible coating. Another unresolved issue relates to the variable toxicity of MWCNTs on different cell types. The present study addressed the effects of MWCNTs' length on mammalian immune and epithelial cancer cells RAW264.7 and MCF-7, respectively. Our data confirm that MWCNTs induce cytotoxicity in a length- and cell type-dependent manner. Whereas, longer (3 to 14 μm) MWCNTs exert high toxicity, especially to RAW264.7 cells, shorter (1.5 μm) MWCNTs are significantly less cytotoxic. These findings confirm that the degree of biocompatibility of MWCNTs is closely related to their length and that immune cells appear to be more susceptible to damage by MWCNTs. Our study also indicates that MWCNT nanotoxicity should be analysed for various components of cellular response, and cytotoxicity data should be validated by the use of more than one assay system. Results from chromogenic-based assays should be confirmed by trypan blue exclusion. PMID:22748010

  1. Luciferase mRNA Transfection of Antigen Presenting Cells Permits Sensitive Nonradioactive Measurement of Cellular and Humoral Cytotoxicity.

    PubMed

    Omokoko, Tana A; Luxemburger, Uli; Bardissi, Shaheer; Simon, Petra; Utsch, Magdalena; Breitkreuz, Andrea; Türeci, Özlem; Sahin, Ugur

    2016-01-01

    Immunotherapy is rapidly evolving as an effective treatment option for many cancers. With the emerging fields of cancer vaccines and adoptive cell transfer therapies, there is an increasing demand for high-throughput in vitro cytotoxicity assays that efficiently analyze immune effector functions. The gold standard (51)Cr-release assay is very accurate but has the major disadvantage of being radioactive. We reveal the development of a versatile and nonradioactive firefly luciferase in vitro transcribed (IVT) RNA-based assay. Demonstrating high efficiency, consistency, and excellent target cell viability, our optimized luciferase IVT RNA is used to transfect dividing and nondividing primary antigen presenting cells. Together with the long-lasting expression and minimal background, the direct measurement of intracellular luciferase activity of living cells allows for the monitoring of killing kinetics and displays paramount sensitivity. The ability to cotransfect the IVT RNA of the luciferase reporter and the antigen of interest into the antigen presenting cells and its simple read-out procedure render the assay high-throughput in nature. Results generated were comparable to the (51)Cr release and further confirmed the assay's ability to measure antibody-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity. The assay's combined simplicity, practicality, and efficiency tailor it for the analysis of antigen-specific cellular and humoral effector functions during the development of novel immunotherapies. PMID:27057556

  2. Luciferase mRNA Transfection of Antigen Presenting Cells Permits Sensitive Nonradioactive Measurement of Cellular and Humoral Cytotoxicity

    PubMed Central

    Omokoko, Tana A.; Luxemburger, Uli; Bardissi, Shaheer; Simon, Petra; Utsch, Magdalena; Breitkreuz, Andrea; Türeci, Özlem; Sahin, Ugur

    2016-01-01

    Immunotherapy is rapidly evolving as an effective treatment option for many cancers. With the emerging fields of cancer vaccines and adoptive cell transfer therapies, there is an increasing demand for high-throughput in vitro cytotoxicity assays that efficiently analyze immune effector functions. The gold standard 51Cr-release assay is very accurate but has the major disadvantage of being radioactive. We reveal the development of a versatile and nonradioactive firefly luciferase in vitro transcribed (IVT) RNA-based assay. Demonstrating high efficiency, consistency, and excellent target cell viability, our optimized luciferase IVT RNA is used to transfect dividing and nondividing primary antigen presenting cells. Together with the long-lasting expression and minimal background, the direct measurement of intracellular luciferase activity of living cells allows for the monitoring of killing kinetics and displays paramount sensitivity. The ability to cotransfect the IVT RNA of the luciferase reporter and the antigen of interest into the antigen presenting cells and its simple read-out procedure render the assay high-throughput in nature. Results generated were comparable to the 51Cr release and further confirmed the assay's ability to measure antibody-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity. The assay's combined simplicity, practicality, and efficiency tailor it for the analysis of antigen-specific cellular and humoral effector functions during the development of novel immunotherapies. PMID:27057556

  3. Different cellular response mechanisms contribute to the length-dependent cytotoxicity of multi-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Liu, Dun; Wang, Lijun; Wang, Zhigang; Cuschieri, Alfred

    2012-07-01

    To date, there has not been an agreement on the best methods for the characterisation of multi-walled carbon nanotube (MWCNT) toxicity. The length of MWCNTs has been identified as a factor in in vitro and in vivo studies, in addition to their purity and biocompatible coating. Another unresolved issue relates to the variable toxicity of MWCNTs on different cell types. The present study addressed the effects of MWCNTs' length on mammalian immune and epithelial cancer cells RAW264.7 and MCF-7, respectively. Our data confirm that MWCNTs induce cytotoxicity in a length- and cell type-dependent manner. Whereas, longer (3 to 14 μm) MWCNTs exert high toxicity, especially to RAW264.7 cells, shorter (1.5 μm) MWCNTs are significantly less cytotoxic. These findings confirm that the degree of biocompatibility of MWCNTs is closely related to their length and that immune cells appear to be more susceptible to damage by MWCNTs. Our study also indicates that MWCNT nanotoxicity should be analysed for various components of cellular response, and cytotoxicity data should be validated by the use of more than one assay system. Results from chromogenic-based assays should be confirmed by trypan blue exclusion.

  4. Size-dependent cytotoxicity of silver nanoparticles in human lung cells: the role of cellular uptake, agglomeration and Ag release

    PubMed Central

    2014-01-01

    Background Silver nanoparticles (AgNPs) are currently one of the most manufactured nanomaterials. A wide range of toxicity studies have been performed on various AgNPs, but these studies report a high variation in toxicity and often lack proper particle characterization. The aim of this study was to investigate size- and coating-dependent toxicity of thoroughly characterized AgNPs following exposure of human lung cells and to explore the mechanisms of toxicity. Methods BEAS-2B cells were exposed to citrate coated AgNPs of different primary particle sizes (10, 40 and 75 nm) as well as to 10 nm PVP coated and 50 nm uncoated AgNPs. The particle agglomeration in cell medium was investigated by photon cross correlation spectroscopy (PCCS); cell viability by LDH and Alamar Blue assay; ROS induction by DCFH-DA assay; genotoxicity by alkaline comet assay and γH2AX foci formation; uptake and intracellular localization by transmission electron microscopy (TEM); and cellular dose as well as Ag release by atomic absorption spectroscopy (AAS). Results The results showed cytotoxicity only of the 10 nm particles independent of surface coating. In contrast, all AgNPs tested caused an increase in overall DNA damage after 24 h assessed by the comet assay, suggesting independent mechanisms for cytotoxicity and DNA damage. However, there was no γH2AX foci formation and no increased production of intracellular reactive oxygen species (ROS). The reasons for the higher toxicity of the 10 nm particles were explored by investigating particle agglomeration in cell medium, cellular uptake, intracellular localization and Ag release. Despite different agglomeration patterns, there was no evident difference in the uptake or intracellular localization of the citrate and PVP coated AgNPs. However, the 10 nm particles released significantly more Ag compared with all other AgNPs (approx. 24 wt% vs. 4–7 wt%) following 24 h in cell medium. The released fraction in cell medium did not induce any

  5. Data supporting the physico-chemical characterization, cellular uptake and cytotoxicity of lipid nanocapsules

    PubMed Central

    Sánchez-Moreno, P.; Ortega-Vinuesa, J.L.; Boulaiz, H.; Marchal, J.A.; Peula-García, J.M.

    2015-01-01

    The aim of this data article is to provide data for a basic knowledge of the properties of lipid nanocapsules, a new colloidal system with very promising applications in drug delivery. Firstly, we pay attention on how it is possible to determine their surface composition by means of electrokinetics measurements. On the other hand, we provide experimental evidences for a better understanding of the factors that determine the interactions of these nanoparticles with cells as a necessary step to guide the design of the most effective formulations. Additionally, we supply information about encapsulation efficiency of docetaxel, a potent chemotherapy drug, inside nanocapsules supporting the experimental cytotoxicity results of these nanosystems. PMID:26217803

  6. Sesquiterpene lactones: Mechanism of antineoplastic activity; relationship of cellular glutathione to cytotoxicity; and disposition

    SciTech Connect

    Grippo, A.A.

    1987-01-01

    Helenalin, a sesquiterpene lactone, inhibited the growth of P388 lymphocytic and L1210 lymphoid leukemia, and Ehrlich ascites and KB carcinoma cells. The L1210 leukemia cells were most sensitive to the cytotoxic effects of helenalin. Helenalin's antineoplastic effects were due to inhibition of DNA synthesis by suppressing the activities of enzymes involved in this biosynthetic pathway; i.e., IMP dehydrogenase, ribonucleoside diphosphate reductase, thioredoxin complex, GSH disulfide oxidoreductase and DNA polymerase {alpha} activities. The relationship of reduced glutathione (GSH) to the cytotoxic effects of helanalin was evaluated. L1210 cells, which were more sensitive to helenalin's toxicity, contained lower basal concentrations of GSH. Helenalin decreased the concentration of reduced glutathione in both L1210 and P388 leukemia cells. Concurrent administration of helanalin with agents reported to raise GSH concentrations did not substantially effect GSH levels, nor were survival times of tumor-bearing mice enhanced. Following intraperitoneal administration of {sup 3}H-plenolin, no radioactive drug and/or metabolite was sequestered in the organs of BDF{sub 1} mice. Approximately 50% of {sup 3}H-plenolin and/or its metabolites were eliminated via urine while lesser amounts of radioactive drug and/or metabolites were eliminated in the feces.

  7. DNA-binding, cytotoxicity, cellular uptake, apoptosis and photocleavage studies of Ru(II) complexes.

    PubMed

    N Deepika; C Shobha Devi; Y Praveen Kumar; K Laxma Reddy; P Venkat Reddy; D Anil Kumar; Surya S Singh; S Satyanarayana

    2016-07-01

    Two Ru(II) complexes [Ru(phen)2bppp](ClO4)2 (1) and [Ru(phen)27-Br-dppz](ClO4)2 (2) [phen=1,10 phenanthroline, 7-Br-dppz=7-fluorodipyrido[3,2-a:2',3'-c]phenazine, bppp=11-bromo-pyrido[2',3':5,6]pyrazino[2,3-f] [1,10]phenanthroline] have been synthesized and characterized by elemental analysis, ES-MS, (1)H-NMR, (13)C-NMR and IR. The in vitro cytotoxicity of the complexes examined against a panel of cancer cell lines (HeLa, Du145 and A549) by MTT method, both complexes show prominent anticancer activity against various cancer cells. Live cell imaging study and flow cytometric analysis demonstrate that both the complexes 1 and 2 could cross the cell membrane accumulating in the nucleus. Further, flow cytometry experiments showed that the cytotoxic Ru(II) complexes 1 and 2 induced apoptosis of HeLa tumor cell lines. Photo induced DNA cleavage studies have been performed and results indicate that both the complexes efficiently photo cleave pBR322 DNA. The binding properties of two complexes toward CT-DNA were investigated by various optical methods and viscosity measurements. The experimental results suggested that both Ru(II) complexes can intercalate into DNA base pairs. The complexes were docked into DNA-base pairs using the GOLD docking program. PMID:27107334

  8. Evaluating Cytotoxicity and Cellular Uptake from the Presence of Variously Processed Ti02 Nanostructured Morphologies

    SciTech Connect

    Chen, J.; Wong, S.; Zhou, H.; Santull, A.C.

    2010-05-01

    We evaluated the cytotoxicity of various morphological classes of TiO{sub 2} nanostructures (including 0-D nanoparticles, 1-D nanorods, and 3-D assemblies) toward living cells. These TiO{sub 2} nanostructures were modified with fluorescent dye molecules, mediated via a dopamine linkage, in order to facilitate a confocal study of their internalization. Specifically, we noted that both TiO{sub 2} 1-D nanorods and 0-D nanoparticles could internalize into cells after 24 h of incubation time. However, only incubation with TiO{sub 2} 1-D nanorods and 3-D micrometer-scale sea urchin-like assemblies at concentrations of up to 125 {mu}g/mL yielded data suggestive of cell viabilities of close to 100%. Moreover, upon irradiation with UV light for periods of a few minutes at energy densities of up to 1 J/cm{sub 2}, we observed up to 60% mortality rates, indicative of the cytotoxic potential of photoirradiated TiO{sub 2} nanostructures due to the generation of reactive oxygen species.

  9. Different hydroxyapatite magnetic nanoparticles for medical imaging: Its effects on hemostatic, hemolytic activity and cellular cytotoxicity.

    PubMed

    Laranjeira, Marta S; Moço, Ana; Ferreira, Jorge; Coimbra, Susana; Costa, Elísio; Santos-Silva, Alice; Ferreira, Paulo J; Monteiro, Fernando J

    2016-10-01

    Magnetic nanoparticles (MNPs) should be highly biocompatible, stable and safely eliminated from the body, and can therefore be successfully used in modern medicine. Synthetic hydroxyapatite (HAP) has well established biocompatible and non-inflammatory properties, as well as a highly stable and flexible structure that allows for an easy incorporation of magnetic ions. This study characterized and compared the in vitro cytotoxicity and hemocompatibility of hydroxyapatite MNPs doped with different ions (Gd(3+/)Fe(2+)/Fe(3+)/Co(2+)). HAP doped with 10% of Gd and Fe(III) presented the highest magnetic moments. Our results showed that Gd doped HAP nanoparticles are non-cytotoxic, hemocompatible, non-hemolytic and non-thrombogenic, in contrast with Fe(III) doped HAP that can be considered thrombogenic. For these reasons we propose that, Gd doped HAP nanoparticles have the most potential for application as a MRI contrast agents. However, use of Fe (III) doped HAP as MRI contrast agents should be further investigated. PMID:27388965

  10. Comparing high-throughput methods to measure NK cell-mediated antibody dependent cellular cytotoxicity during HIV-infection.

    PubMed

    Konstantinus, Iyaloo N; Gamieldien, Hoyam; Mkhize, Nonhlanhla N; Kriek, Jean-Mari; Passmore, Jo-Ann S

    2016-07-01

    HIV-specific binding antibody responses, including those mediating antibody-dependent cellular cytotoxicity (ADCC), provided the best functional correlate of lower risk of infection in the RV144 HIV-1 vaccine clinical trial. The aim of this study was to compare two high-throughput flow cytometry based methods to measure HIV-specific ADCC responses, the GranToxilux and PanToxilux assays. Plasma from nine HIV-1 seropositive individuals was screened for binding antibody titres against HIV-1 subtype C gp120 by ELISA and western blot. Plasma from six HIV-negative individuals was included as controls. Both ADCC assays used subtype C gp120-coated CEM.NKRCCR5 cells as targets. The PanToxilux assay (which measured both granzyme B and caspase activity) measured higher levels of direct natural killer (NK) cell killing of K562 tumour cells than the GranToxilux assay (granzyme B alone; p<0.05). In ADCC assays in which NK cell killing was directed against gp120-coated CEM.NKRCCR5 cells in an antibody-dependent manner, plasma from HIV-positive individuals yielded significantly higher levels of ADCC activity than the HIV-negative controls. In contrast to direct killing, the GranToxilux assay measured similar levels of ADCC killing as the PanToxilux assay but had significantly lower background cytotoxicity against target cells coated with HIV negative serum. In conclusion, the PanToxilux assay was more sensitive for detecting direct NK cell killing of K562 cells than the GranToxilux assay, although the GranToxilux assay performed better at detecting HIV-specific ADCC activity, because of lower background cytotoxicity from HIV-negative serum. This is the first study to compare GranToxilux and PanToxilux ability to detect ADCC during HIV infection. PMID:27094485

  11. Cytotoxicity and variant cellular internalization behavior of water-soluble sulfonated nanographene sheets in liver cancer cells

    PubMed Central

    2013-01-01

    Highly exfoliated sulfonated graphene sheets (SGSs), an alternative to graphene oxide and graphene derivatives, were synthesized, characterized, and applied to liver cancer cells in vitro. Cytotoxicity profiles were obtained using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, WST-1[2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium, and lactate dehydrogenase release colorimetric assays. These particles were found to be non-toxic across the concentration range of 0.1 to 10 μg/ml. Internalization of SGSs was also studied by means of optical and electron microscopy. Although not conclusive, high-resolution transmission and scanning electron microscopy revealed variant internalization behaviors where some of the SGS became folded and compartmentalized into tight bundles within cellular organelles. The ability for liver cancer cells to internalize, fold, and compartmentalize graphene structures is a phenomenon not previously documented for graphene cell biology and should be further investigated. PMID:23639042

  12. Cellular and complement-dependent cytotoxicity of Ep-CAM-specific monoclonal antibody MT201 against breast cancer cell lines

    PubMed Central

    Prang, N; Preithner, S; Brischwein, K; Göster, P; Wöppel, A; Müller, J; Steiger, C; Peters, M; Baeuerle, P A; da Silva, A J

    2005-01-01

    MT201 is a fully human monoclonal IgG1 antibody with moderate affinity for epithelial cell adhesion molecule (Ep-CAM) being clinically developed for the treatment of carcinomas. Like many other clinically validated IgG1 monoclonal antibodies, MT201 primarily acts by antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC). Here, we analysed ADCC and CDC induced by MT201 and, as reference, trastuzumab against a panel of nine human breast cancer cell lines expressing distinct surface levels of Ep-CAM and human epithelial growth factor receptor type 2 antigen. Maximal cell lysis by ADCC by MT201 and trastuzumab in the presence of peripheral mononuclear cells did not significantly differ when averaged over the nine cell lines, but showed marked differences with respect to individual cell lines. The extent of cell lysis at intermediate surface target density was highly variable, suggesting a dominant influence of other susceptibility factors. Only one breast cancer cell line was eliminated via CDC, but only by MT201. Resistance to CDC appeared to correlate with high expression levels of complement resistance factors. Our present data as well as recent data on the prevalence and prognostic relevance of Ep-CAM expression in metastatic breast cancer suggest that Ep-CAM-specific monoclonal IgG1 antibodies may have a significant therapeutic potential in the treatment of breast cancer. PMID:15655555

  13. The cytotoxicity of polycationic iron oxide nanoparticles: Common endpoint assays and alternative approaches for improved understanding of cellular response mechanism

    PubMed Central

    2012-01-01

    Background Iron oxide magnetic nanoparticles (MNP's) have an increasing number of biomedical applications. As such in vitro characterisation is essential to ensure the bio-safety of these particles. Little is known on the cellular interaction or effect on membrane integrity upon exposure to these MNPs. Here we synthesised Fe3O4 and surface coated with poly(ethylenimine) (PEI) and poly(ethylene glycol) (PEG) to achieve particles of varying surface positive charges and used them as model MNP's to evaluate the relative utility and limitations of cellular assays commonly applied for nanotoxicity assessment. An alternative approach, atomic force microscopy (AFM), was explored for the analysis of membrane structure and cell morphology upon interacting with the MNPs. The particles were tested in vitro on human SH-SY5Y, MCF-7 and U937 cell lines for reactive oxygen species (ROS) production and lipid peroxidation (LPO), LDH leakage and their overall cytotoxic effect. These results were compared with AFM topography imaging carried out on fixed cell lines. Results Successful particle synthesis and coating were characterised using FTIR, PCS, TEM and ICP. The particle size from TEM was 30 nm (−16.9 mV) which increased to 40 nm (+55.6 mV) upon coating with PEI and subsequently 50 nm (+31.2 mV) with PEG coating. Both particles showed excellent stability not only at neutral pH but also in acidic environment of pH 4.6 in the presence of sodium citrate. The higher surface charge MNP-PEI resulted in increased cytotoxic effect and ROS production on all cell lines compared with the MNP-PEI-PEG. In general the effect on the cell membrane integrity was observed only in SH-SY5Y and MCF-7 cells by MNP-PEI determined by LDH leakage and LPO production. AFM topography images showed consistently that both the highly charged MNP-PEI and the less charged MNP-PEI-PEG caused cell morphology changes possibly due to membrane disruption and cytoskeleton remodelling. Conclusions Our findings

  14. Oxidation of cellular amino acid pools leads to cytotoxic mistranslation of the genetic code

    PubMed Central

    Bullwinkle, Tammy J; Reynolds, Noah M; Raina, Medha; Moghal, Adil; Matsa, Eleftheria; Rajkovic, Andrei; Kayadibi, Huseyin; Fazlollahi, Farbod; Ryan, Christopher; Howitz, Nathaniel; Faull, Kym F; Lazazzera, Beth A; Ibba, Michael

    2014-01-01

    Aminoacyl-tRNA synthetases use a variety of mechanisms to ensure fidelity of the genetic code and ultimately select the correct amino acids to be used in protein synthesis. The physiological necessity of these quality control mechanisms in different environments remains unclear, as the cost vs benefit of accurate protein synthesis is difficult to predict. We show that in Escherichia coli, a non-coded amino acid produced through oxidative damage is a significant threat to the accuracy of protein synthesis and must be cleared by phenylalanine-tRNA synthetase in order to prevent cellular toxicity caused by mis-synthesized proteins. These findings demonstrate how stress can lead to the accumulation of non-canonical amino acids that must be excluded from the proteome in order to maintain cellular viability. DOI: http://dx.doi.org/10.7554/eLife.02501.001 PMID:24891238

  15. NK Cell and Ig Interplay in Defense against Herpes Simplex Virus Type 1: Epistatic Interaction of CD16A and IgG1 Allotypes of Variable Affinities Modulates Antibody-Dependent Cellular Cytotoxicity and Susceptibility to Clinical Reactivation.

    PubMed

    Moraru, Manuela; Black, Laurel E; Muntasell, Aura; Portero, Francisca; López-Botet, Miguel; Reyburn, Hugh T; Pandey, Janardan P; Vilches, Carlos

    2015-08-15

    HSV-1 latently infects most humans, causing a variable clinical picture that depends, in part, on host genetic factors. Both IgG and its cellular FcRs, CD16A and CD32A-C (encoded by FCGR3A and FCGR2A-C, respectively, on chromosome 1), display polymorphisms that could affect their defensive function. Of potential relevance are a FCGR3A dimorphism resulting in CD16A-valine/phenylalanine-158 allotypes with different IgG affinity, variations conditioning NK cell expression of CD32B or CD32C, and IgG1 H chain (IGHG1) and kappa-chain (IGKC) polymorphisms determining allotypes designated G1m and Km. In this study, we assessed the contribution of Ig genetic variations and their interaction with FcR polymorphism to HSV-1 susceptibility, as well as their impact on NK cell-mediated Ab-dependent cellular cytotoxicity (ADCC). Our results show an epistatic interaction between IGHG1 and FCGR3A such that the higher affinity CD16A-158V/V genotype associates with an asymptomatic course of HSV-1 infection only in homozygotes for G1m3. Furthermore, CD16A-158V and G1m3 allotypes enhanced ADCC against opsonized HSV-1-infected fibroblasts. Conversely, Km allotypes and CD32B or CD32C expression on NK cells did not significantly influence HSV-1 susceptibility or ADCC. NK cells degranulating against immune serum-opsonized HSV-1-infected fibroblasts had heterogeneous phenotypes. Yet, enhanced ADCC was observed among NK cells showing a differentiated, memory-like phenotype (NKG2C(bright)NKG2A(-)CD57(+)FcRγ(-)), which expand in response to human CMV. These results extend our knowledge on the importance of immunogenetic polymorphisms and NK cell-Ab interplay in the host response against HSV-1 and point to the relevance of interactions between immune responses elicited during chronic coinfection by multiple herpesviruses. PMID:26179905

  16. The cytotoxicity and cellular stress by temperature-fabricated polyshaped gold nanoparticles using marine macroalgae, Padina gymnospora.

    PubMed

    Singh, Manoj; Saurav, Kumar; Majouga, Alexander; Kumari, Mamta; Kumar, Manish; Manikandan, S; Kumaraguru, A K

    2015-01-01

    Bioreduction of metal ions for the synthesis of stable nanoparticles (NPs) in physiological environment has been a great challenge in the field of nanotechnology and its application. In the present study, well-defined biofunctionalized gold nanoparticles (AuNPs) were developed following a biomimetic approach for an enhanced anticancer activity. The fucoxanthins-capped crystalline AuNPs showed a particle size of 14 nm. The temperature-mediated biosynthesized NPs were characterized by UV-vis, dynamic light scattering, high-resolution transmission electron microscopy, and energy-dispersive X-ray spectroscopy. The cytotoxicity of the NPs was analyzed on liver (HepG2) and lung (A549) cancerous cells. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay infers that the biofunctionalized polyshaped AuNPs synthesized with an aqueous macroalgae extract showed a satisfactory anticancer effect on the cell lines, as evaluated by changes in cell morphology, cell viability, and metabolic activity. An altered cellular function and the morphology of cancer cell lines suggest a potential for in vivo application of AuNPs and the need to understand the interactions between nanomaterials, biomolecules, and cellular components. With continued improvements, these NPs may prove to be potential drug delivery vehicles for cancer therapy. PMID:25041078

  17. Impaired antibody-dependent cellular cytotoxicity mediated by herceptin in patients with gastric cancer.

    PubMed

    Kono, Koji; Takahashi, Akihiro; Ichihara, Fumiko; Sugai, Hidemitsu; Fujii, Hideki; Matsumoto, Yoshirou

    2002-10-15

    The humanized monoclonal antibody Herceptin, which specifically targets HER-2/neu, exhibits growth inhibitory activity against HER-2/neu-overexpressing tumors and is approved for therapeutic use with proved survival benefit in patients with HER-2/neu-positive breast cancer. In the present study, we investigated whether Herceptin could affect the HER-2/neu-overexpressing gastric cancer cells based on antibody-dependent cell-mediated cytotoxicity (ADCC) and compared immune effector cells from gastric cancer patients with normal individuals on ADCC. HER-2/neu-expressing gastric cancer cells could be killed by Herceptin-mediated ADCC and the Herceptin-induced ADCC correlated with the degree of HER-2/neu expression on the gastric cancer cells. However, the Herceptin-mediated ADCC was significantly impaired in peripheral blood mononuclear cells from advanced disease patients (n = 10) compared with that in early disease (n = 12; P = 0.04) or healthy individuals (n = 10, P = 0.02). Moreover, natural killer (NK) cells purified from patients with advanced disease indicated less Herceptin-mediated ADCC in comparison with that from healthy donors (P = 0.04), whereas monocytes purified from the patients showed an almost equal amount of Herceptin-mediated ADCC in comparison with that from healthy individuals, indicating that NK cell dysfunction contributed to the impaired Herceptin-mediated ADCC in gastric cancer patients. Furthermore, the NK-cell dysfunction on Herceptin-mediated ADCC correlated with the down-regulation of CD16zeta expression in the patients, and interleukin 2 ex vivo treatment of NK cells could restore the impairment of Herceptin-mediated ADCC, concomitant to the normalization of the expression of CD16zeta molecules. Thus, some modalities such as interleukin 2 treatment aimed at reversing NK dysfunction may be necessary for successful Herceptin treatment of gastric cancer. PMID:12384543

  18. Cellular cytotoxicity mediated by isotype-switch variants of a monoclonal antibody to human neuroblastoma.

    PubMed Central

    d'Uscio, C. H.; Jungi, T. W.; Blaser, K.

    1991-01-01

    The biological property of an antibody is determined by its antigen binding characteristics and its isotype-related effector functions. We have established monoclonal antibodies of different isotypes by stepwise selection and cloning of the hybridoma CE7. The original CE7 secretes an IgG1/kappa (CE7 gamma 1) antibody that recognises a 185 kD cell surface glycoprotein expressed on all human sympatho-adrenomedullary cells. Isotype-switch variants were isolated in the following sequence: from the original CE7 gamma 1, CE7 gamma 2b variants were isolated, and from a CE7 gamma 2b variant CE7 gamma 2a variants were isolated. The antibodies of three different isotype variant cell lines possess identical antigen binding characteristics, but display distinct effector functions as demonstrated by antibody dependent cell-mediated cytotoxicity (ADCC). ADCC was performed with the neuroblastoma line IMR-32 as the target cells, and different FcR gamma positive cells were either freshly isolated from human peripheral blood leukocytes or cultured for 6-10 days and tested as potential effector cells. Tumour lysis mediated by monocyte-derived macrophages depended on the presence of CE7 gamma 2a antibodies; antibodies from the CE7 hybridomas of gamma 2b and gamma 1 isotypes were virtually inactive in ADCC assay. Pre-exposure of macrophages to rIFN-gamma enhanced their ADCC activity, a result that is compatible with the notion that the high affinity Fc IgG receptor (FcR gamma I/CD64) is involved in the triggering of ADCC in macrophages. In contrast to macrophages, mononuclear cells, nonadherent cells and monocytes displayed considerable non-specific lytic activity, which was little influenced by the presence of antibody regardless of the isotype added. PMID:1911183

  19. NK Cell-Mediated Antibody-Dependent Cellular Cytotoxicity in Cancer Immunotherapy

    PubMed Central

    Wang, Wei; Erbe, Amy K.; Hank, Jacquelyn A.; Morris, Zachary S.; Sondel, Paul M.

    2015-01-01

    Natural killer (NK) cells play a major role in cancer immunotherapies that involve tumor-antigen targeting by monoclonal antibodies (mAbs). NK cells express a variety of activating and inhibitory receptors that serve to regulate the function and activity of the cells. In the context of targeting cells, NK cells can be “specifically activated” through certain Fc receptors that are expressed on their cell surface. NK cells can express FcγRIIIA and/or FcγRIIC, which can bind to the Fc portion of immunoglobulins, transmitting activating signals within NK cells. Once activated through Fc receptors by antibodies bound to target cells, NK cells are able to lyse target cells without priming, and secrete cytokines like interferon gamma to recruit adaptive immune cells. This antibody-dependent cell-mediated cytotoxicity (ADCC) of tumor cells is utilized in the treatment of various cancers overexpressing unique antigens, such as neuroblastoma, breast cancer, B cell lymphoma, and others. NK cells also express a family of receptors called killer immunoglobulin-like receptors (KIRs), which regulate the function and response of NK cells toward target cells through their interaction with their cognate ligands that are expressed on tumor cells. Genetic polymorphisms in KIR and KIR-ligands, as well as FcγRs may influence NK cell responsiveness in conjunction with mAb immunotherapies. This review focuses on current therapeutic mAbs, different strategies to augment the anti-tumor efficacy of ADCC, and genotypic factors that may influence patient responses to antibody-dependent immunotherapies. PMID:26284063

  20. Cytotoxicity and cellular uptake of ZnS:Mn nanocrystals biofunctionalized with chitosan and aminoacids

    NASA Astrophysics Data System (ADS)

    Sajimol Augustine, M.; Anas, Abdulaziz; Das, Ani V.; Sreekanth, S.; Jayalekshmi, S.

    2015-02-01

    Highly luminescent, manganese doped, zinc sulphide (ZnS:Mn) nanocrystals biofunctionalized with chitosan and various aminoacids such as L-citrulline, L-lysine, L-arginine, L-serine, L-histidine and glycine were synthesized by chemical capping co-precipitation method at room temperature, which is a simple and cost effective technique. The synthesized nanocrystals were structurally characterized by TEM, XRD, EDXS and FT-IR spectroscopy techniques. They possess high colloidal stability with strong orange red photoluminescence emission at 598 nm. The intensity of orange red emission has been observed to be maximum in L-citrulline capped ZnS:Mn nanocrystals in which the emission at 420 nm is effectively quenched by surface passivation due to capping. Taking into consideration the prospects of these highly luminescent, bio-compatible ZnS:Mn nanocrystals in bio-imaging applications, cytotoxicity studies were conducted to identify the capping combination which would accomplish minimum toxic effects. ZnS:Mn nanocrystals biofunctionalized with chitosan, L-citrulline, glycine, L-artginine, L-serine and L-histidine showed least toxicity up to 10 nM concentrations in mouse fibroblast L929 cells, which further confirms their cytocompatibility. Also the ZnS:Mn nanocrystals biofunctionalized with L-arginine showed maximum uptake in in vitro studies carried out in human embryonic kidney cells, HEK-293T, which shows the significant role of this particular amino acid in fetoplacental nutrition. The present study highlights the suitability of aminoacid conjugated ZnS:Mn nanocrystals, as promising candidates for biomedical applications.

  1. Cytotoxic effects of Mn(III) N-alkylpyridylporphyrins in the presence of cellular reductant, ascorbate

    PubMed Central

    Ye, Xiaodong; Fels, Diane; Tovmasyan, Artak; Aird, Katherine M.; Dedeugd, Casey; Allensworth, Jennifer L.; Kos, Ivan; Park, Won; Spasojevic, Ivan; Devi, Gayathri R.; Dewhirst, Mark W.; Leong, Kam W.; Batinic-Haberle, Ines

    2012-01-01

    Due to the ability to easily accept and donate electrons Mn(III) N-alkylpyridylporphyrins (MnPs) can dismute O2˙−, reduce peroxynitrite, but also generate reactive species and behave as pro-oxidants if conditions favour such action. Herein two ortho isomers, MnTE-2-PyP5+, MnTnHex-2-PyP5+, and a meta isomer MnTnHex-3-PyP5+, which differ greatly with regard to their metal-centered reduction potential, E1/2 (MnIIIP/MnIIP) and lipophilicity, were explored. Employing MnIIIP/MnIIP redox system for coupling with ascorbate, these MnPs catalyze ascorbate oxidation and thus peroxide production. Consequently, cancer oxidative burden may be enhanced, which in turn would suppress its growth. Cytotoxic effects on Caco-2, Hela, 4T1, HCT116 and SUM149 were studied. When combined with ascorbate, MnPs killed cancer cells via peroxide produced outside of the cell. MnTE-2-PyP5+ was the most efficacious catalyst for peroxide production, while MnTnHex-3-PyP5+ is most prone to oxidative degradation with H2, and thus the least efficacious. A 4T1 breast cancer mouse study of limited scope and success was conducted. The tumour oxidative stress was enhanced and its microvessel density reduced when mice were treated either with ascorbate or MnP/ascorbate; the trend towards tumour growth suppression was detected. PMID:21859376

  2. Shape and surface chemistry effects on the cytotoxicity and cellular uptake of metallic nanorods and nanospheres.

    PubMed

    Favi, Pelagie Marlene; Valencia, Mariana Morales; Elliott, Paul Robert; Restrepo, Alejandro; Gao, Ming; Huang, Hanchen; Pavon, Juan Jose; Webster, Thomas Jay

    2015-12-01

    Metallic nanoparticles (such as gold and silver) have been intensely studied for wound healing applications due to their ability to be easily functionalized, possess antibacterial properties, and their strong potential for targeted drug release. In this study, rod-shaped silver nanorods (AgNRs) and gold nanorods (AuNRs) were fabricated by electron beam physical vapor deposition (EBPVD), and their cytotoxicity toward human skin fibroblasts were assessed and compared to sphere-shaped silver nanospheres (AgNSs) and gold nanospheres (AuNSs). Results showed that the 39.94 nm AgNSs showed the greatest toxicity with fibroblast cells followed by the 61.06 nm AuNSs, ∼556 nm × 47 nm (11.8:1 aspect ratio) AgNRs, and the ∼534 nm × 65 nm (8.2:1 aspect ratio) AuNRs demonstrated the least amount of toxicity. The calculated IC50 (50% inhibitory concentration) value for the AgNRs exposed to fibroblasts was greater after 4 days of exposure (387.3 μg mL(-1)) compared to the AgNSs and AuNSs (4.3 and 23.4 μg mL(-1), respectively), indicating that these spherical metallic nanoparticles displayed a greater toxicity to fibroblast cells. The IC50 value could not be measured for the AuNRs due to an incomplete dose response curve. The reduced cell toxicity with the presently developed rod-shaped nanoparticles suggests that they may be promising materials for use in numerous biomedical applications. PMID:26053238

  3. Cetuximab-mediated cellular cytotoxicity is inhibited by HLA-E membrane expression in colon cancer cells.

    PubMed

    Levy, Estrella Mariel; Sycz, Gabriela; Arriaga, Juan Martin; Barrio, María Marcela; von Euw, Erika María; Morales, Sergio Bayo; González, Mariana; Mordoh, José; Bianchini, Michele

    2009-04-01

    Cetuximab, an anti-epidermal growth factor receptor monoclonal antibody, has been shown to increase the median survival of colorectal cancer patients. We previously reported that the expression of HLA-E is significantly increased in primary human colorectal cancer, perhaps contributing to tumour escape from immune surveillance. To establish if HLA-E could be a factor that renders colorectal cancer cells less susceptible to antibody-dependent cellular cytotoxicity (ADCC), in the present study we analysed Cetuximab-mediated cytotoxicity against several colorectal cancer cell lines expressing, or not, HLA-E at the cell surface. We first observed that colorectal cancer cells treated with Cetuximab were killed more efficiently by ADCC. Interestingly, treatment of target cells with recombinant human-beta2-microglobulin inhibits Cetuximab-mediated ADCC through HLA-E membrane stabilization. The specific immunosuppressive role of HLA-E was confirmed using an anti-NKG2A monoclonal antibody, that restored the ability of immune cells to kill their target. This result demonstrates that HLA-E at the cell surface can reliably suppress the ADCC effect. On the other hand, Cetuximab induced a direct growth inhibition but only at high concentrations; furthermore, the CDC effect was quite moderate, and we failed to observe a pro-apoptotic effect. Taking into account that our findings suggest that ADCC activity is the main anti-tumour effect observed at clinically achievable concentrations of Cetuximab at the tumour site, we suggest that determination of HLA-E in colorectal cancer could be relevant to predict success of Cetuximab treatment. PMID:19318419

  4. Cellular uptake and cytotoxicity of a near-IR fluorescent corrole-TiO2 nanoconjugate.

    PubMed

    Blumenfeld, Carl M; Sadtler, Bryce F; Fernandez, G Esteban; Dara, Lily; Nguyen, Cathie; Alonso-Valenteen, Felix; Medina-Kauwe, Lali; Moats, Rex A; Lewis, Nathan S; Grubbs, Robert H; Gray, Harry B; Sorasaenee, Karn

    2014-11-01

    We are investigating the biological and biomedical imaging roles and impacts of fluorescent metallocorrole-TiO2 nanoconjugates as potential near-infrared optical contrast agents in vitro in cancer and normal cell lines. The TiO2 nanoconjugate labeled with the small molecule 2,17-bis(chlorosulfonyl)-5,10,15-tris(pentafluorophenyl)corrolato aluminum(III) (1-Al-TiO2) was prepared. The nanoparticle 1-Al-TiO2 was characterized by transmission electron microscopy (TEM) and integrating-sphere electronic absorption spectroscopy. TEM images of three different samples of TiO2 nanoparticles (bare, H2O2 etched, and 1-Al functionalized) showed similarity in shapes and sizes with an average diameter of 29nm for 1-Al-TiO2. Loading of 1-Al on the TiO2 surfaces was determined to be ca. 20-40mg 1-Al/g TiO2. Confocal fluorescence microscopy (CFM) studies of luciferase-transfected primary human glioblastoma U87-Luc cells treated with the nanoconjugate 1-Al-TiO2 as the contrast agent in various concentrations were performed. The CFM images revealed that 1-Al-TiO2 was found inside the cancer cells even at low doses (0.02-2μg/mL) and localized in the cytosol. Bioluminescence studies of the U87-Luc cells exposed to various amounts of 1-Al-TiO2 showed minimal cytotoxic effects even at higher doses (2-2000μg/mL) after 24h. A similar observation was made using primary mouse hepatocytes (PMH) treated with 1-Al-TiO2 at low doses (0.0003-3μg/mL). Longer incubation times (after 48 and 72h for U87-Luc) and higher doses (>20μg/mL 1-Al-TiO2 for U87-Luc and >3μg/mL 1-Al-TiO2 for PMH) showed decreased cell viability. PMID:25061689

  5. Synthesis of Carbohydrate Capped Silicon Nanoparticles and their Reduced Cytotoxicity, In Vivo Toxicity, and Cellular Uptake.

    PubMed

    Ahire, Jayshree H; Behray, Mehrnaz; Webster, Carl A; Wang, Qi; Sherwood, Victoria; Saengkrit, Nattika; Ruktanonchai, Uracha; Woramongkolchai, Noppawan; Chao, Yimin

    2015-08-26

    The development of smart targeted nanoparticles (NPs) that can identify and deliver drugs at a sustained rate directly to cancer cells may provide better efficacy and lower toxicity for treating primary and advanced metastatic tumors. Obtaining knowledge of the diseases at the molecular level can facilitate the identification of biological targets. In particular, carbohydrate-mediated molecular recognitions using nano-vehicles are likely to increasingly affect cancer treatment methods, opening a new area in biomedical applications. Here, silicon NPs (SiNPs) capped with carbohydrates including galactose, glucose, mannose, and lactose are successfully synthesized from amine terminated SiNPs. The MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] analysis shows an extensive reduction in toxicity of SiNPs by functionalizing with carbohydrate moiety both in vitro and in vivo. Cellular uptake is investigated with flow cytometry and confocal fluorescence microscope. The results show the carbohydrate capped SiNPs can be internalized in the cells within 24 h of incubation, and can be taken up more readily by cancer cells than noncancerous cells. Moreover, these results reinforce the use of carbohydrates for the internalization of a variety of similar compounds into cancer cells. PMID:26121084

  6. Biocompatible transferrin-conjugated sodium hexametaphosphate-stabilized gold nanoparticles: synthesis, characterization, cytotoxicity and cellular uptake

    NASA Astrophysics Data System (ADS)

    Parab, Harshala J.; Huang, Jing-Hong; Lai, Tsung-Ching; Jan, Yi-Hua; Liu, Ru-Shi; Wang, Jui-Ling; Hsiao, Michael; Chen, Chung-Hsuan; Hwu, Yeu-Kuang; Tsai, Din Ping; Chuang, Shih-Yi; Pang, Jong-Hwei S.

    2011-09-01

    The feasibility of using gold nanoparticles (AuNPs) for biomedical applications has led to considerable interest in the development of novel synthetic protocols and surface modification strategies for AuNPs to produce biocompatible molecular probes. This investigation is, to our knowledge, the first to elucidate the synthesis and characterization of sodium hexametaphosphate (HMP)-stabilized gold nanoparticles (Au-HMP) in an aqueous medium. The role of HMP, a food additive, as a polymeric stabilizing and protecting agent for AuNPs is elucidated. The surface modification of Au-HMP nanoparticles was carried out using polyethylene glycol and transferrin to produce molecular probes for possible clinical applications. In vitro cell viability studies performed using as-synthesized Au-HMP nanoparticles and their surface-modified counterparts reveal the biocompatibility of the nanoparticles. The transferrin-conjugated nanoparticles have significantly higher cellular uptake in J5 cells (liver cancer cells) than control cells (oral mucosa fibroblast cells), as determined by inductively coupled plasma mass spectrometry. This study demonstrates the possibility of using an inexpensive and non-toxic food additive, HMP, as a stabilizer in the large-scale generation of biocompatible and monodispersed AuNPs, which may have future diagnostic and therapeutic applications.

  7. Neutralizing Antibody Response and Antibody-Dependent Cellular Cytotoxicity in HIV-1-Infected Individuals from Guinea-Bissau and Denmark.

    PubMed

    Borggren, Marie; Jensen, Sanne Skov; Heyndrickx, Leo; Palm, Angelica A; Gerstoft, Jan; Kronborg, Gitte; Hønge, Bo Langhoff; Jespersen, Sanne; da Silva, Zacarias José; Karlsson, Ingrid; Fomsgaard, Anders

    2016-05-01

    The development of therapeutic and prophylactic HIV vaccines for African countries is urgently needed, but the question of what immunogens to use needs to be answered. One approach is to include HIV envelope immunogens derived from HIV-positive individuals from a geographically concentrated epidemic with more limited viral genetic diversity for a region-based vaccine. To address if there is a basis for a regional selected antibody vaccine, we have screened two regionally separate cohorts from Guinea-Bissau and Denmark for neutralizing antibody activity and antibody-dependent cellular cytotoxicity (ADCC) against local and nonlocal circulating HIV-1 strains. The neutralizing activity did not demonstrate higher potential against local circulating strains according to geography and subtype determination, but the plasma from Danish individuals demonstrated significantly higher inhibitory activity than that from Guinea-Bissau individuals against both local and nonlocal virus strains. Interestingly, an opposite pattern was observed with ADCC activity, where Guinea-Bissau individual plasma demonstrated higher activity than Danish plasma and was specifically against the local circulating subtype. Thus, on basis of samples from these two cohorts, no local-specific neutralizing activity was detected, but a local ADCC response was identified in the Guinea-Bissau samples, suggesting potential use of regional immunogens for an ADCC-inducing vaccine. PMID:26621287

  8. Brief Report: Seminal Plasma Anti-HIV Antibodies Trigger Antibody-dependent Cellular Cytotoxicity: Implications for HIV Transmission.

    PubMed

    Parsons, Matthew S; Madhavi, Vijaya; Ana-Sosa-Batiz, Fernanda; Center, Rob J; Wilson, Kim M; Bunupuradah, Torsak; Ruxrungtham, Kiat; Kent, Stephen J

    2016-01-01

    Recent evidence from HIV vaccine trials in humans and non-human primates suggests that nonneutralizing antibody functions, such as antibody-dependent cellular cytotoxicity (ADCC), are an important component of vaccine-mediated protection. Whether anti-HIV ADCC antibodies are present in seminal fluid, however, is not known. We assessed whether anti-HIV antibodies within seminal plasma mediate ADCC and activate natural killer (NK) cells. Using matched blood and seminal plasma samples, we detected anti-HIV IgG within samples from all 11 HIV-infected donors. Furthermore, anti-HIV antibodies within the seminal plasma triggered detectable ADCC in 9 of 11 donors and activated NK cells in 6 of 11 donors. The ability of seminal plasma-derived IgG to activate NK cells in an anti-HIV antibody-dependent manner was enhanced when IgG were enriched and other seminal plasma components were removed. These observations have relevance for understanding natural immunity to HIV infection and provide assistance with HIV vaccine design. PMID:26761269

  9. Correlation of particle properties with cytotoxicity and cellular uptake of hydroxyapatite nanoparticles in human gastric cancer cells.

    PubMed

    Cui, Xinhui; Liang, Tong; Liu, Changsheng; Yuan, Yuan; Qian, Jiangchao

    2016-10-01

    Three types of hydroxyapatite nanoparticles (HAPNs) were synthesized employing a sonochemistry-assisted microwave method by changing microwave power (from 200 to 300W) or using calcination treatment: L200 (200W, lyophilization), L300 (300W, lyophilization) and C200 (200W, lyophilization & calcination). Their physiochemical properties were characterized and correlated with cytotoxicity to human gastric cancer cells (MGC80-3). The major differences among these HAPN preparations were their size and specific surface area, with the L200 showing a smaller size and higher specific surface area. Although all HAPNs inhibited cell proliferation and induced apoptosis of cancer cells, L200 exhibited the greatest toxicity. All types of HAPNs were internalized through energy-dependent pathways, but the L200 nanoparticles were more efficiently uptaken by MGC80-3 cells. Inhibitor studies with dynasore and methyl-β-cyclodextrin suggested that caveolae-mediated endocytosis and, to a much lesser extent, clathrin-mediated endocytosis, were involved in cellular uptake of the various preparations, whereas the inhibition of endocytosis was more obvious for L200. Using fluorescein isothiocyanate-labeled HAPNs and laser-scanning confocal microscopy, we found that all forms of nanoparticles were present in the cytoplasm, and some L200 HAPNs were even found within nuclei. Treatment with all HAPN preparations led to the increase in the intracellular calcium level with the highest level detected for L200. PMID:27287142

  10. A Highly Conserved Residue of the HIV-1 gp120 Inner Domain Is Important for Antibody-Dependent Cellular Cytotoxicity Responses Mediated by Anti-cluster A Antibodies

    PubMed Central

    Ding, Shilei; Veillette, Maxime; Coutu, Mathieu; Prévost, Jérémie; Scharf, Louise; Bjorkman, Pamela J.; Ferrari, Guido; Robinson, James E.; Stürzel, Christina; Hahn, Beatrice H.; Sauter, Daniel; Kirchhoff, Frank; Lewis, George K.; Pazgier, Marzena

    2015-01-01

    Previous studies have shown that sera from HIV-1-infected individuals contain antibodies able to mediate antibody-dependent cellular cytotoxicity (ADCC). These antibodies preferentially recognize envelope glycoprotein (Env) epitopes induced upon CD4 binding. Here, we show that a highly conserved tryptophan at position 69 of the gp120 inner domain is important for ADCC mediated by anti-cluster A antibodies and sera from HIV-1-infected individuals. PMID:26637462

  11. Asymmetrical Fc Engineering Greatly Enhances Antibody-dependent Cellular Cytotoxicity (ADCC) Effector Function and Stability of the Modified Antibodies*

    PubMed Central

    Liu, Zhi; Gunasekaran, Kannan; Wang, Wei; Razinkov, Vladimir; Sekirov, Laura; Leng, Esther; Sweet, Heather; Foltz, Ian; Howard, Monique; Rousseau, Anne-Marie; Kozlosky, Carl; Fanslow, William; Yan, Wei

    2014-01-01

    Antibody-dependent cellular cytotoxicity (ADCC) is mediated through the engagement of the Fc segment of antibodies with Fcγ receptors (FcγRs) on immune cells upon binding of tumor or viral antigen. The co-crystal structure of FcγRIII in complex with Fc revealed that Fc binds to FcγRIII asymmetrically with two Fc chains contacting separate regions of the FcγRIII by utilizing different residues. To fully explore this asymmetrical nature of the Fc-FcγR interaction, we screened more than 9,000 individual clones in Fc heterodimer format in which different mutations were introduced at the same position of two Fc chains using a high throughput competition AlphaLISA® assay. To this end, we have identified a panel of novel Fc variants with significant binding improvement to FcγRIIIA (both Phe-158 and Val-158 allotypes), increased ADCC activity in vitro, and strong tumor growth inhibition in mice xenograft human tumor models. Compared with previously identified Fc variants in conventional IgG format, Fc heterodimers with asymmetrical mutations can achieve similar or superior potency in ADCC-mediated tumor cell killing and demonstrate improved stability in the CH2 domain. Fc heterodimers also allow more selectivity toward activating FcγRIIA than inhibitory FcγRIIB. Afucosylation of Fc variants further increases the affinity of Fc to FcγRIIIA, leading to much higher ADCC activity. The discovery of these Fc variants will potentially open up new opportunities of building the next generation of therapeutic antibodies with enhanced ADCC effector function for the treatment of cancers and infectious diseases. PMID:24311787

  12. X-linked inhibitor of apoptosis protein mediates tumor cell resistance to antibody-dependent cellular cytotoxicity

    PubMed Central

    Evans, M K; Sauer, S J; Nath, S; Robinson, T J; Morse, M A; Devi, G R

    2016-01-01

    Inflammatory breast cancer (IBC) is the deadliest, distinct subtype of breast cancer. High expression of epidermal growth factor receptors [EGFR or human epidermal growth factor receptor 2 (HER2)] in IBC tumors has prompted trials of anti-EGFR/HER2 monoclonal antibodies to inhibit oncogenic signaling; however, de novo and acquired therapeutic resistance is common. Another critical function of these antibodies is to mediate antibody-dependent cellular cytotoxicity (ADCC), which enables immune effector cells to engage tumors and deliver granzymes, activating executioner caspases. We hypothesized that high expression of anti-apoptotic molecules in tumors would render them resistant to ADCC. Herein, we demonstrate that the most potent caspase inhibitor, X-linked inhibitor of apoptosis protein (XIAP), overexpressed in IBC, drives resistance to ADCC mediated by cetuximab (anti-EGFR) and trastuzumab (anti-HER2). Overexpression of XIAP in parental IBC cell lines enhances resistance to ADCC; conversely, targeted downregulation of XIAP in ADCC-resistant IBC cells renders them sensitive. As hypothesized, this ADCC resistance is in part a result of the ability of XIAP to inhibit caspase activity; however, we also unexpectedly found that resistance was dependent on XIAP-mediated, caspase-independent suppression of reactive oxygen species (ROS) accumulation, which otherwise occurs during ADCC. Transcriptome analysis supported these observations by revealing modulation of genes involved in immunosuppression and oxidative stress response in XIAP-overexpressing, ADCC-resistant cells. We conclude that XIAP is a critical modulator of ADCC responsiveness, operating through both caspase-dependent and -independent mechanisms. These results suggest that strategies targeting the effects of XIAP on caspase activation and ROS suppression have the potential to enhance the activity of monoclonal antibody-based immunotherapy. PMID:26821068

  13. X-linked inhibitor of apoptosis protein mediates tumor cell resistance to antibody-dependent cellular cytotoxicity.

    PubMed

    Evans, M K; Sauer, S J; Nath, S; Robinson, T J; Morse, M A; Devi, G R

    2016-01-01

    Inflammatory breast cancer (IBC) is the deadliest, distinct subtype of breast cancer. High expression of epidermal growth factor receptors [EGFR or human epidermal growth factor receptor 2 (HER2)] in IBC tumors has prompted trials of anti-EGFR/HER2 monoclonal antibodies to inhibit oncogenic signaling; however, de novo and acquired therapeutic resistance is common. Another critical function of these antibodies is to mediate antibody-dependent cellular cytotoxicity (ADCC), which enables immune effector cells to engage tumors and deliver granzymes, activating executioner caspases. We hypothesized that high expression of anti-apoptotic molecules in tumors would render them resistant to ADCC. Herein, we demonstrate that the most potent caspase inhibitor, X-linked inhibitor of apoptosis protein (XIAP), overexpressed in IBC, drives resistance to ADCC mediated by cetuximab (anti-EGFR) and trastuzumab (anti-HER2). Overexpression of XIAP in parental IBC cell lines enhances resistance to ADCC; conversely, targeted downregulation of XIAP in ADCC-resistant IBC cells renders them sensitive. As hypothesized, this ADCC resistance is in part a result of the ability of XIAP to inhibit caspase activity; however, we also unexpectedly found that resistance was dependent on XIAP-mediated, caspase-independent suppression of reactive oxygen species (ROS) accumulation, which otherwise occurs during ADCC. Transcriptome analysis supported these observations by revealing modulation of genes involved in immunosuppression and oxidative stress response in XIAP-overexpressing, ADCC-resistant cells. We conclude that XIAP is a critical modulator of ADCC responsiveness, operating through both caspase-dependent and -independent mechanisms. These results suggest that strategies targeting the effects of XIAP on caspase activation and ROS suppression have the potential to enhance the activity of monoclonal antibody-based immunotherapy. PMID:26821068

  14. Cytotoxicity of quantum dots used for in vitro cellular labeling: role of QD surface ligand, delivery modality, cell type, and direct comparison to organic fluorophores.

    PubMed

    Bradburne, Christopher E; Delehanty, James B; Boeneman Gemmill, Kelly; Mei, Bing C; Mattoussi, Hedi; Susumu, Kimihiro; Blanco-Canosa, Juan B; Dawson, Philip E; Medintz, Igor L

    2013-09-18

    Interest in taking advantage of the unique spectral properties of semiconductor quantum dots (QDs) has driven their widespread use in biological applications such as in vitro cellular labeling/imaging and sensing. Despite their demonstrated utility, concerns over the potential toxic effects of QD core materials on cellular proliferation and homeostasis have persisted, leaving in question the suitability of QDs as alternatives for more traditional fluorescent materials (e.g., organic dyes, fluorescent proteins) for in vitro cellular applications. Surprisingly, direct comparative studies examining the cytotoxic potential of QDs versus these more traditional cellular labeling fluorophores remain limited. Here, using CdSe/ZnS (core/shell) QDs as a prototypical assay material, we present a comprehensive study in which we characterize the influence of QD dose (concentration and incubation time), QD surface capping ligand, and delivery modality (peptide or cationic amphiphile transfection reagent) on cellular viability in three human cell lines representing various morphological lineages (epithelial, endothelial, monocytic). We further compare the effects of QD cellular labeling on cellular proliferation relative to those associated with a panel of traditionally employed organic cell labeling fluorophores that span a broad spectral range. Our results demonstrate the important role played by QD dose, capping ligand structure, and delivery agent in modulating cellular toxicity. Further, the results show that at the concentrations and time regimes required for robust QD-based cellular labeling, the impact of our in-house synthesized QD materials on cellular proliferation is comparable to that of six commercial cell labeling fluorophores. Cumulatively, our results demonstrate that the proper tuning of QD dose, surface ligand, and delivery modality can provide robust in vitro cell labeling reagents that exhibit minimal impact on cellular viability. PMID:23879393

  15. Env-Specific IgA from Viremic HIV-Infected Subjects Compromises Antibody-Dependent Cellular Cytotoxicity

    PubMed Central

    Ruiz, María Julia; Ghiglione, Yanina; Falivene, Juliana; Laufer, Natalia; Holgado, María Pía; Socías, María Eugenia; Cahn, Pedro; Sued, Omar; Giavedoni, Luis; Salomón, Horacio; Gherardi, María Magdalena; Rodríguez, Ana María

    2015-01-01

    ABSTRACT Elucidating the factors that modulate HIV-specific antibody-dependent cellular cytotoxicity (ADCC) will help in understanding its role in HIV immunity. The aim of this study was to determine whether IgA could modify the magnitude of ADCC in HIV infection, abrogating its protective role. Plasma samples from 20 HIV-positive (HIV+) subjects enrolled during primary HIV infection (PHI), 10 chronically infected subjects (chronic), and 7 elite controllers (EC) were used. ADCC was determined by using a fluorometric ADCC assay, before and after removal of plasma IgA. Data were analyzed by using nonparametric statistics. ADCC was documented in 80% of PHI enrollment samples and in 100% of PHI 12-month, chronic, and EC samples; it peaked after acute infection, reached a plateau in chronic infection, and decreased after initiation of antiretroviral treatment (ART). Significant associations between ADCC and disease progression were found only after removal of plasma IgA from 12-month PHI samples: the magnitude of ADCC not only increased after IgA removal but also correlated with CD4+ T-cell preservation. This work provides evidence that gp120-specific IgA was capable of modifying ADCC responses during natural HIV infection for the first time and adds to similar evidence provided in other settings. Furthermore, it underscores the complexity of the ADCC phenomenon and will help in an understanding of its underlying mechanisms. IMPORTANCE Although the induction of ADCC-mediating antibodies in HIV-infected subjects has been extensively documented, the association of these antibodies with protection from disease progression is poorly understood. Here, we demonstrate that plasma IgA is a factor capable of modifying the magnitude of IgG-mediated ADCC in HIV infection, mitigating its beneficial effect. These results help in understanding why previous studies failed to demonstrate correlations between ADCC and disease progression, and they also contribute to the notion that an

  16. Synthesis of Mg-Fe-Cl hydrotalcite-like nanoplatelets as an oral phosphate binder: evaluations of phosphorus intercalation activity and cellular cytotoxicity

    PubMed Central

    Lung, Yung-Feng; Sun, Ying-Sui; Lin, Chun-Kai; Uan, Jun-Yen; Huang, Her-Hsiung

    2016-01-01

    The patients with end-stage of renal disease (ESRD) need to take oral phosphate binder. Traditional phosphate binders may leave the disadvantage of aluminum intoxication or cardiac calcification. Herein, Mg-Fe-Cl hydrotalcite-like nanoplatelet (HTln) is for the first time characterized as potential oral phosphate binder, with respect to its phosphorus uptake capacity in cow milk and cellular cytotoxicity. A novel method was developed for synthesizing the Mg-Fe-Cl HTln powder in different Mg2+: Fe3+ ratios where the optimization was 2.8:1. Addition of 0.5 g Mg-Fe-Cl HTln in cow milk could reduce its phosphorus content by 40% in 30 min and by 65% in 90 min. In low pH environment, the Mg-Fe-Cl HTln could exhibit relatively high performance for uptaking phosphorus. During a 90 min reaction of the HTln in milk, no phosphorus restoration occurred. In-vitro cytotoxicity assay of Mg-Fe-Cl HTln revealed no potential cellular cytotoxicity. The cells that were cultured in the HTln extract-containing media were even more viable than cells that were cultured in extract-free media (blank control). The Mg-Fe-Cl HTln extract led to hundred ppm of Mg ion and some ppm of Fe ion in the media, should be a positive effect on the good cell viability. PMID:27581184

  17. Synthesis of Mg-Fe-Cl hydrotalcite-like nanoplatelets as an oral phosphate binder: evaluations of phosphorus intercalation activity and cellular cytotoxicity.

    PubMed

    Lung, Yung-Feng; Sun, Ying-Sui; Lin, Chun-Kai; Uan, Jun-Yen; Huang, Her-Hsiung

    2016-01-01

    The patients with end-stage of renal disease (ESRD) need to take oral phosphate binder. Traditional phosphate binders may leave the disadvantage of aluminum intoxication or cardiac calcification. Herein, Mg-Fe-Cl hydrotalcite-like nanoplatelet (HTln) is for the first time characterized as potential oral phosphate binder, with respect to its phosphorus uptake capacity in cow milk and cellular cytotoxicity. A novel method was developed for synthesizing the Mg-Fe-Cl HTln powder in different Mg(2+): Fe(3+) ratios where the optimization was 2.8:1. Addition of 0.5 g Mg-Fe-Cl HTln in cow milk could reduce its phosphorus content by 40% in 30 min and by 65% in 90 min. In low pH environment, the Mg-Fe-Cl HTln could exhibit relatively high performance for uptaking phosphorus. During a 90 min reaction of the HTln in milk, no phosphorus restoration occurred. In-vitro cytotoxicity assay of Mg-Fe-Cl HTln revealed no potential cellular cytotoxicity. The cells that were cultured in the HTln extract-containing media were even more viable than cells that were cultured in extract-free media (blank control). The Mg-Fe-Cl HTln extract led to hundred ppm of Mg ion and some ppm of Fe ion in the media, should be a positive effect on the good cell viability. PMID:27581184

  18. DNA Binding and Photocleavage Properties, Cellular Uptake and Localization, and in-Vitro Cytotoxicity of Dinuclear Ruthenium(II) Complexes with Varying Lengths in Bridging Alkyl Linkers.

    PubMed

    Liu, Ping; Wu, Bao-Yan; Liu, Jin; Dai, Yong-Cheng; Wang, You-Jun; Wang, Ke-Zhi

    2016-02-15

    Two new dinuclear Ru(II) polypyridyl complexes containing three and ten methylene chains in their bridging linkers are synthesized and characterized. Their calf thymus DNA-binding and plasmid DNA photocleavage behaviors are comparatively studied with a previously reported, six-methylene-containing analog by absorption and luminescence spectroscopy, steady-state emission quenching by [Fe(CN)6](4-), DNA competitive binding with ethidium bromide, DNA viscosity measurements, DNA thermal denaturation, and agarose gel electrophoresis analyses. Theoretical calculations applying the density functional theory (DFT) method for the three complexes are also performed to understand experimentally observed DNA binding properties. The results show that the two complexes partially intercalate between the base pairs of DNA. Cellular uptake and colocalization studies have demonstrated that the complexes could enter HeLa cells efficiently and localize within lysosomes. The in-vitro antitumor activity against HeLa and MCF-7 tumor cells of the complexes are studied by MTT cytotoxic analysis. A new method, high-content analysis (HCA), is also used to assess cytotoxicity, apoptosis and cell cycle arrest of the three complexes. The results show that the lengths of the alkyl linkers could effectively tune their biological properties and that HCA is suitable for rapidly identifying cytotoxicity and can be substituted for MTT assays to evaluate the cell cytotoxicity of chemotherapeutic agents. PMID:26811966

  19. Separation of effector cells mediating antibody-dependent cellular cytotoxicity (ADC) to erythrocyte targets from those mediating ADC to tumor targets.

    PubMed

    Pollack, S B; Nelson, K; Grausz, J D

    1976-04-01

    Murine spleen cells mediate antibody-dependent cellular cytotoxicity (ADC) both to erythrocyte targets in a 51Cr release assay and to syngeneic tumor targets in a microcytotoxicity assay. The effector cells active in the two ADC assays can be separated by passage of the spleen cells through columns of Sephadex G-10 at 37 degrees C. Cells mediating ADC to sarcoma cells did not adhere to the G-10 and were recovered in the column effluent. These nonadherent cells were not cytotoxic to antibody-coated chicken red blood cells. Spleen cells which mediated ADC in a 51Cr release assay to the red cell targets adhered to G-10. Adherent effector cells could subsequently be recovered from the columns by elution with 5 X 10(-4) M EDTA. PMID:815438

  20. Cellular Uptake and Cytotoxic Effect of Epidermal Growth Factor Receptor Targeted and Plitidepsin Loaded Co-Polymeric Polymersomes on Colorectal Cancer Cell Lines.

    PubMed

    Goñi-de-Cerio, Felipe; Thevenot, Julie; Oliveira, Hugo; Pérez-Andrés, Encarnación; Berra, Edurne; Masa, Marc; Suárez-Merino, Blanca; Lecommandoux, Sébastien; Heredia, Pedro

    2015-11-01

    Encapsulating chemotherapy drugs in targeted nanodelivery systems is one of the most promising approaches to tackle cancer disease, avoiding side effects of common treatment. In the last decade, several nanocarriers with different nature have been tested, but polypeptide-based copolymers have attracted considerable attention for their biocompatibility, controlled and slow biodegradability as well as their low toxicity. In this work, we synthesized, characterized and evaluated poly(trimethylene carbonate)-bock-poly(L-glutamic acid) derived polymersomes, targeted to epidermal growth factor receptor (EGFR), loaded with plitidepsin and ultimately tested in HT29 and LS174T colorectal cancer cell lines for specificity and efficacy. Furthermore, morphology, physico-chemical properties and plitidepsin loading were carefully investigated. A thorough in vitro cytotoxicity analysis of the unloaded polymersomes was carried out for biocompatibility check, studying viability, cell membrane asymmetry and reactive oxygen species levels. Those cytotoxicity assays showed good biocompatibility for plitidepsin-unloaded polymersomes. Cellular uptake and cytotoxic effect of EGFR targeted and plitidepsin loaded polymersome indicated that colorectal cancer cell lines were.more sensitive to anti-EGFR-drug-loaded than untargeted drug-loaded polymersomes. Also, in both cell lines, the use of untargeted polymersomes greatly reduced plitidepsin cytotoxicity as well as the cellular uptake, indicating that the use of this targeted nanocarrier is a promising approach to tackle colorectal cancer disease and avoid the undesired effects of the usual treatment. Furthermore, in vivo assays support the in vitro conclusions that EGFR targeted polymersomes could be a good drug delivery system. This work provides a proof of concept for the use of encapsulated targeted drugs as future therapeutic treatments for cancer. PMID:26554161

  1. APOL1 kidney disease risk variants cause cytotoxicity by depleting cellular potassium and inducing stress-activated protein kinases

    PubMed Central

    Olabisi, Opeyemi A.; Zhang, Jia-Yue; VerPlank, Lynn; Zahler, Nathan; DiBartolo, Salvatore; Heneghan, John F.; Schlöndorff, Johannes S.; Suh, Jung Hee; Yan, Paul; Alper, Seth L.; Friedman, David J.; Pollak, Martin R.

    2016-01-01

    Two specific genetic variants of the apolipoprotein L1 (APOL1) gene are responsible for the high rate of kidney disease in people of recent African ancestry. Expression in cultured cells of these APOL1 risk variants, commonly referred to as G1 and G2, results in significant cytotoxicity. The underlying mechanism of this cytotoxicity is poorly understood. We hypothesized that this cytotoxicity is mediated by APOL1 risk variant-induced dysregulation of intracellular signaling relevant for cell survival. To test this hypothesis, we conditionally expressed WT human APOL1 (G0), the APOL1 G1 variant, or the APOL1 G2 variant in human embryonic kidney cells (T-REx-293) using a tetracycline-mediated (Tet-On) system. We found that expression of either G1 or G2 APOL1 variants increased apparent cell swelling and cell death compared with G0-expressing cells. These manifestations of cytotoxicity were preceded by G1 or G2 APOL1-induced net efflux of intracellular potassium as measured by X-ray fluorescence, resulting in the activation of stress-activated protein kinases (SAPKs), p38 MAPK, and JNK. Prevention of net K+ efflux inhibited activation of these SAPKs by APOL1 G1 or G2. Furthermore, inhibition of SAPK signaling and inhibition of net K+ efflux abrogated cytotoxicity associated with expression of APOL1 risk variants. These findings in cell culture raise the possibility that nephrotoxicity of APOL1 risk variants may be mediated by APOL1 risk variant-induced net loss of intracellular K+ and subsequent induction of stress-activated protein kinase pathways. PMID:26699492

  2. A new cell line for high throughput HIV-specific antibody-dependent cellular cytotoxicity (ADCC) and cell-to-cell virus transmission studies.

    PubMed

    Orlandi, Chiara; Flinko, Robin; Lewis, George K

    2016-06-01

    Several lines of evidence indicate that antibody-dependent cellular cytotoxicity (Wren et al., 2013) is important in the pathogenesis of HIV-1 infection. Namely, ADCC is induced during natural HIV-1 infection or in HIV-1 vaccine studies, the latter demonstrated by the RV144 vaccine trial. To expedite the assessment of ADCC in studies of HIV, we have developed a high throughput assay. We have optimized the rapid fluorometric antibody-mediated cytotoxicity assay (RFADCC) by transfecting the EGFP-CEM-NKr cell line to constitutively express SNAP-tagged CCR5. This cell line can then serve as a source of HIV-specific targets when coated with monomeric gp120, spinoculated with inactivated intact virions, infected by cell-free viral diffusion or infected by cell-to-cell transmission of virus. The optimized strategy has two significant advantages over the original RFADCC method: First, the preparation of detectable target cells is less labor intensive and faster as it does not rely on multiple staining and washing steps for target cells. Second, because the target cell markers GFP and SNAP are constitutively expressed, the assay provides highly reproducible data. These strengths make the optimized RFADCC assay suitable not only for studies of HIV-1 specific cytotoxicity but also for studies of cell-cell transmission of virus. In conclusion, this assay provides a new generation T cell line that can expedite large clinical studies as well as research studies in humans or non-human primates. PMID:26969387

  3. Cellular Uptake, DNA Binding and Apoptosis Induction of Cytotoxic Trans-[PtCl2(N,N-dimethylamine)(Isopropylamine)] in A2780cisR Ovarian Tumor Cells

    PubMed Central

    Pérez, José M.; Montero, Eva I.; Quiroga, Adoración G.; Fuertes, Miguel A; Alonso, Carlos

    2001-01-01

    Trans-[PtCl2(N,N-dimethylamine)(isopropylamine)] is a novel trans-platinum compound that shows cytotoxic activity in several cisplatin resistant cell lines. The aim of this paper was to analyse, by means of molecular cell biology techniques and total reflection X-ray fluorescence (TXRF), the cytotoxic activity, the induction of apoptosis, the cellular uptake and the DNA binding of trans-[PtCl2(N,N-dimethylamine)(isopropylamine)] in the cisplatin resistant cell line A2780cisR. The results show that this drug is more cytotoxic and induces a higher amount of apoptotic cells than cisplatin in A2780cisR cells. However, the intracellular accumulation and extent of binding to DNA of trans-[PtCl2(N,N-dimethylamine)( isopropylamine)] is lower than that of cis-DDP. Moreover, trans-[PtCl2(N,N-dimethylamine)(isopropylaminae)] is partially inactivated by intracellular levels of glulathione. The result suggest that circumvention of ciplatin resistance by trans-[PtCl2(N,N-dimethylamine)(isopropylamine)] in A2780cisR cells might be related with the ability of this drug to induce apoptosis. PMID:18475973

  4. A new cell line for high throughput HIV-specific antibody-dependent cellular cytotoxicity (ADCC) and cell-to-cell virus transmission studies

    PubMed Central

    Orlandi, Chiara; Flinko, Robin; Lewis, George K.

    2016-01-01

    Several lines of evidence indicate that antibody-dependent cellular cytotoxicity (Wren et al., 2013) is important in the pathogenesis of HIV-1 infection. Namely, ADCC is induced during natural HIV-1 infection or in HIV-1 vaccine studies, the latter demonstrated by the RV144 vaccine trial. To expedite the assessment of ADCC in studies of HIV, we have developed a high throughput assay. We have optimized the rapid fluorometric antibody-mediated cytotoxicity assay (RFADCC) by transfecting the EGFP-CEM-NKr cell line to constitutively express SNAP-tagged CCR5. This cell line can then serve as a source of HIV-specific targets when coated with monomeric gp120, spinoculated with inactivated intact virions, infected by cell-free viral diffusion or infected by cell-to-cell transmission of virus. The optimized strategy has two significant advantages over the original RFADCC method: First, the preparation of detectable target cells is less labor intensive and faster as it does not rely on multiple staining and washing steps for target cells. Second, because the target cell markers GFP and SNAP are constitutively expressed, the assay provides highly reproducible data. These strengths make the optimized RFADCC assay suitable not only for studies of HIV-1 specific cytotoxicity but also for studies of cell–cell transmission of virus. In conclusion, this assay provides a new generation T cell line that can expedite large clinical studies as well as research studies in humans or non-human primates. PMID:26969387

  5. Mechanisms of corticosteroid action on lymphocyte subpopulations. III. Differential effects of dexamethasone administration on subpopulations of effector cells mediating cellular cytotoxicity in man

    PubMed Central

    Parrillo, J. E.; Fauci, A. S.

    1978-01-01

    The present study investigated the effect of dexamethasone (DEX) administration on different populations of mononuclear cells and neutrophils mediating antibody-dependent cellular cytotoxicity (ADCC) against different target cells. Mononuclear cells (lymphocytes and monocytes) and neutrophils were obtained from twenty-seven normal volunteers at 0, 4, 24 and 48 hr after oral administration of 21 mg of DEX. ADCC was determined utilizing the following targets: human red blood cells (HRBC), Chang liver cells (Ch) and human heart cells (HHC). The predominant mononuclear effector in HRBC killing was shown to be a monocyte and in Ch and HHC killing, a K cell. As previously shown, DEX produced a profound monocytopenia and lymphocytopenia at 4 hr with a return of lymphocyte counts to normal and monocyte counts to supra-normal at 24 hr. At the point of maximal monocytopenia, monocyte-mediated HRBC killing decreased from a geometric mean of 14 to 4 lytic units per 108 effector cells (P<0·05) and rebounded at 24 hr to a mean of 39 lytic units (P<0·02) with the rebound monocytosis. At the point of absolute lymphopenia (4 hr), there was a relative enrichment in the proportion of lymphocytes bearing an Fc receptor (K cells, P<0·01). Concomitant with this was an increase in ADCC against Ch and HHC from geometric means of 1121 to 7172 lytic units and 939 to 7354 lytic units (P<0·001) respectively. Thus, a major action of DEX administration on mononuclear ADCC was to differentially enrich or deplete different effector cells to and from the circulation, causing changes in cytotoxicity. Since the cytotoxicity paralleled the proportion of effector cells, the cells remaining in the circulation following DEX administration retained normal antibody-dependent cytotoxic capabilities. Neutrophil-mediated ADCC against HRBC significantly increased at 4 hr from a geometric mean of 3785 to 20142 lytic units (P<0·02) concomitant with the blood neutrophilia and remained elevated for 72 hr

  6. Protein coronas on gold nanorods passivated with amphiphilic ligands affect cytotoxicity and cellular response to penicillin/streptomycin.

    PubMed

    Kah, James Chen Yong; Grabinski, Christin; Untener, Emily; Garrett, Carol; Chen, John; Zhu, David; Hussain, Saber M; Hamad-Schifferli, Kimberly

    2014-05-27

    We probe how amphiphilic ligands (ALs) of four different types affect the formation of protein coronas on gold nanorods (NRs) and their impact on cellular response. NRs coated with cetyltrimethylammonium bromide were ligand exchanged with polyoxyethylene[10]cetyl ether, oligofectamine, and phosphatidylserine (PS). Protein coronas from equine serum (ES) were formed on these NR-ALs, and their colloidal stability, as well as cell uptake, proliferation, oxidative stress, and gene expression, were examined. We find that the protein corona that forms and its colloidal stability are affected by AL type and that the cellular response to these NR-AL-coronas (NR-AL-ES) is both ligand and corona dependent. We also find that the presence of common cell culture supplement penicillin/streptomycin can impact the colloidal stability and cellular response of NR-AL and NR-AL-ES, showing that the cell response is not necessarily inert to pen/strep when in the presence of nanoparticles. Although the protein corona is what the cells see, the underlying surface ligands evidently play an important role in shaping and defining the physical characteristics of the corona, which ultimately impacts the cellular response. Further, the results of this study suggest that the cellular behavior toward NR-AL is mediated by not only the type of AL and the protein corona it forms but also its resulting colloidal stability and interaction with cell culture supplements. PMID:24758495

  7. Cellular mechanisms of the cytotoxicity of the anticancer drug elesclomol and its complex with Cu(II).

    PubMed

    Hasinoff, Brian B; Wu, Xing; Yadav, Arun A; Patel, Daywin; Zhang, Hui; Wang, De-Shen; Chen, Zhe-Sheng; Yalowich, Jack C

    2015-02-01

    The potent anticancer drug elesclomol, which forms an extremely strong complex with copper, is currently undergoing clinical trials. However, its mechanism of action is not well understood. Treatment of human erythroleukemic K562 cells with either elesclomol or Cu(II)-elesclomol caused an immediate halt in cell growth which was followed by a loss of cell viability after several hours. Treatment of K562 cells also resulted in induction of apoptosis as measured by annexin V binding. Elesclomol or Cu(II)-elesclomol treatment caused a G1 cell cycle block in synchronized Chinese hamster ovary cells. Elesclomol and Cu(II)-elesclomol induced DNA double strand breaks in K562 cells, suggesting that they may also have exerted their cytotoxicity by damaging DNA. Cu(II)-elesclomol also weakly inhibited DNA topoisomerase I (5.99.1.2) but was not active against DNA topoisomerase IIα (5.99.1.3). Elesclomol or Cu(II)-elesclomol treatment had little effect on the mitochondrial membrane potential of viable K562 cells. NCI COMPARE analysis showed that Cu(II)-elesclomol exerted its cytotoxicity by mechanisms similar to other cytotoxic copper chelating compounds. Experiments with cross-resistant cell lines overexpressing several ATP-binding cassette (ABC) type efflux transporters showed that neither elesclomol nor Cu(II)-elesclomol were cross-resistant to cells overexpressing either ABCB1 (Pgp) or ABCG2 (BCRP), but that cells overexpressing ABCC1 (MRP1) were slightly cross-resistant. In conclusion, these results showed that elesclomol caused a rapid halt in cell growth, induced apoptosis, and may also have inhibited cell growth, in part, through its ability to damage DNA. PMID:25550273

  8. Cellular Uptake and Photo-Cytotoxicity of a Gadolinium(III)-DOTA-Naphthalimide Complex "Clicked" to a Lipidated Tat Peptide.

    PubMed

    O'Malley, William I; Rubbiani, Riccardo; Aulsebrook, Margaret L; Grace, Michael R; Spiccia, Leone; Tuck, Kellie L; Gasser, Gilles; Graham, Bim

    2016-01-01

    A new bifunctional macrocyclic chelator featuring a conjugatable alkynyl-naphthalimide fluorophore pendant group has been prepared and its Gd(III) complex coupled to a cell-penetrating lipidated azido-Tat peptide derivative using Cu(I)-catalysed "click" chemistry. The resulting fluorescent conjugate is able to enter CAL-33 tongue squamous carcinoma cells, as revealed by confocal microscopy, producing a very modest anti-proliferative effect (IC50 = 93 µM). Due to the photo-reactivity of the naphthalimide moiety, however, the conjugate's cytotoxicity is significantly enhanced (IC50 = 16 µM) upon brief low-power UV-A irradiation. PMID:26861271

  9. No evident dose-response relationship between cellular ROS level and its cytotoxicity--a paradoxical issue in ROS-based cancer therapy.

    PubMed

    Zhu, Chunpeng; Hu, Wei; Wu, Hao; Hu, Xun

    2014-01-01

    Targeting cancer via ROS-based mechanism has been proposed as a radical therapeutic approach. Cancer cells exhibit higher endogenous oxidative stress than normal cells and pharmacological ROS insults via either enhancing ROS production or inhibiting ROS-scavenging activity can selectively kill cancer cells. In this study, we randomly chose 4 cancer cell lines and primary colon or rectal cancer cells from 4 patients to test the hypothesis and obtained following paradoxical results: while piperlongumin (PL) and β-phenylethyl isothiocyanate (PEITC), 2 well-defined ROS-based anticancer agents, induced an increase of cellular ROS and killed effectively the tested cells, lactic acidosis (LA), a common tumor environmental factor that plays multifaceted roles in promoting cancer progression, induced a much higher ROS level in the tested cancer cells than PL and PEITC, but spared them; L-buthionine sulfoximine (L-BSO, 20 μM) depleted cellular GSH more effectively and increased higher ROS level than PL or PEITC but permitted progressive growth of the tested cancer cells. No evident dose-response relationship between cellular ROS level and cytotoxicity was observed. If ROS is the effecter, it should obey the fundamental therapeutic principle - the dose-response relationship. This is a major concern. PMID:24848642

  10. γδ T Cell-Mediated Antibody-Dependent Cellular Cytotoxicity with CD19 Antibodies Assessed by an Impedance-Based Label-Free Real-Time Cytotoxicity Assay.

    PubMed

    Seidel, Ursula Jördis Eva; Vogt, Fabian; Grosse-Hovest, Ludger; Jung, Gundram; Handgretinger, Rupert; Lang, Peter

    2014-01-01

    γδ T cells are not MHC restricted, elicit cytotoxicity against various malignancies, are present in early post-transplant phases in novel stem cell transplantation strategies and have been shown to mediate antibody-dependent cellular cytotoxicity (ADCC) with monoclonal antibodies (mAbs). These features make γδ T cells promising effector cells for antibody-based immunotherapy in pediatric patients with B-lineage acute lymphoblastic leukemia (ALL). To evaluate combination of human γδ T cells with CD19 antibodies for immunotherapy of B-lineage ALL, γδ T cells were expanded after a GMP-compliant protocol and ADCC of both primary and expanded γδ T cells with an Fc-optimized CD19 antibody (4G7SDIE) and a bi-specific antibody with the specificities CD19 and CD16 (N19-C16) was evaluated in CD107a-degranulation assays and intracellular cytokine staining. CD107a, TNFα, and IFNγ expression of primary γδ T cells were significantly increased and correlated with CD16-expression of γδ T cells. γδ T cells highly expressed CD107a after expansion and no further increased expression by 4G7SDIE and N19-C16 was measured. Cytotoxicity of purified expanded γδ T cells targeting CD19-expressing cells was assessed in both europium-TDA release and in an impedance-based label-free method (using the xCELLigence system) measuring γδ T cell lysis in real-time. Albeit in the 2 h end-point europium-TDA release assay no increased lysis was observed, in real-time xCELLigence assays both significant antibody-independent cytotoxicity and ADCC of γδ T cells were observed. The xCELLigence system outperformed the end-point europium-TDA release assay in sensitivity and allows drawing of conclusions to lysis kinetics of γδ T cells over prolonged periods of time periods. Combination of CD19 antibodies with primary as well as expanded γδ T cells exhibits a promising approach, which may enhance clinical outcome of patients with pediatric B-lineage ALL and requires clinical

  11. Generation of new peptide-Fc fusion proteins that mediate antibody-dependent cellular cytotoxicity against different types of cancer cells

    PubMed Central

    Sioud, Mouldy; Westby, Phuong; Olsen, Julie Kristine E.; Mobergslien, Anne

    2015-01-01

    Antibody-dependent cellular cytotoxicity (ADCC), a key effector function for the clinical effectiveness of monoclonal antibodies, is triggered by the engagement of the antibody Fc domain with the Fcγ receptors expressed by innate immune cells such as natural killer (NK) cells and macrophages. Here, we fused cancer cell-binding peptides to the Fc domain of human IgG1 to engineer novel peptide-Fc fusion proteins with ADCC activity. The designed fusion proteins were expressed in human embryonic kidney 293T cells, followed by purification and characterization by western blots. One of the engineered variants (WN-Fc), bound with high affinity to a wide range of solid tumor cell lines (e.g., colon, lung, prostate, skin, ovarian, and mammary tumors). Treatment of cancer cells with the engineered peptide-Fc fusions in the presence of effector NK cells potentially enhanced cytotoxicity, degranulation, and interferon-γ production by NK cells when compared to cells treated with the Fc control. The presence of competing peptides inhibited NK cell activation. Furthermore, a bispecific peptide-Fc fusion protein activated NK cells against HER-1- and/or HER-2-expressing cancer cells. Collectively, the engineered peptide-Fc fusions constitute a new promising strategy to recruit and activate NK cells against tumor cells, a primary goal of cancer immunotherapy. PMID:26605373

  12. HIV-Specific Antibody-Dependent Cellular Cytotoxicity (ADCC) -Mediating Antibodies Decline while NK Cell Function Increases during Antiretroviral Therapy (ART)

    PubMed Central

    Jensen, Sanne Skov; Fomsgaard, Anders; Borggren, Marie; Tingstedt, Jeanette Linnea; Gerstoft, Jan; Kronborg, Gitte; Rasmussen, Line Dahlerup; Pedersen, Court; Karlsson, Ingrid

    2015-01-01

    Understanding alterations in HIV-specific immune responses during antiretroviral therapy (ART), such as antibody-dependent cellular cytotoxicity (ADCC), is important in the development of novel strategies to control HIV-1 infection. This study included 53 HIV-1 positive individuals. We evaluated the ability of effector cells and antibodies to mediate ADCC separately and in combination using the ADCC-PanToxiLux assay. The ability of the peripheral blood mononuclear cells (PBMCs) to mediate ADCC was significantly higher in individuals who had been treated with ART before seroconversion, compared to the individuals initiating ART at a low CD4+ T cell count (<350 cells/μl blood) and the ART-naïve individuals. The frequency of CD16 expressing natural killer (NK) cells correlated with both the duration of ART and Granzyme B (GzB) activity. In contrast, the plasma titer of antibodies mediating ADCC declined during ART. These findings suggest improved cytotoxic function of the NK cells if initiating ART early during infection, while the levels of ADCC mediating antibodies declined during ART. PMID:26696395

  13. Methyl 6-Amino-6-deoxy-d-pyranoside-Conjugated Platinum(II) Complexes for Glucose Transporter (GLUT)-Mediated Tumor Targeting: Synthesis, Cytotoxicity, and Cellular Uptake Mechanism.

    PubMed

    Li, Taoli; Gao, Xiangqian; Yang, Liu; Shi, Yunli; Gao, Qingzhi

    2016-05-19

    Methyl 6-aminodeoxy-d-pyranoside-derived platinum(II) glycoconjugates were designed and synthesized based on the clinical drug oxaliplatin for glucose transporter (GLUT)-mediated tumor targeting. In addition to a substantial improvement in water solubility, the conjugates exhibited cytotoxicity similar to or higher than that of oxaliplatin in six different human cancer cell lines. GLUT-mediated transport of the complexes was investigated with a cell-based fluorescence competition assay and GLUT-inhibitor-mediated cytotoxicity analysis in a GLUT-overexpressing human colorectal adenocarcinoma (HT29) cell line. The antitumor effect of the aminodeoxypyranoside-conjugated platinum(II) complexes was found to depend significantly on the GLUT inhibitor, and the cellular uptake of the molecules was regulated by GLUT-mediated transport. The results from this study demonstrate the potential advantages of aminodeoxypyranosides as sugar motifs for glycoconjugation for Warburg-effect-targeted drug design. These fundamental results also support the potential of aminodeoxypyranoside-conjugated platinum(II) complexes as lead compounds for further preclinical evaluation. PMID:27135196

  14. Lenalidomide enhances antibody-dependent cellular cytotoxicity of solid tumor cells in vitro: influence of host immune and tumor markers.

    PubMed

    Wu, Lei; Parton, Anastasia; Lu, Ling; Adams, Mary; Schafer, Peter; Bartlett, J Blake

    2011-01-01

    We evaluated the effect of combining lenalidomide with therapeutic antibodies on antibody-dependant cell-mediated cytotoxicity (ADCC) of solid tumor cells, and the requirement for expression of natural killer (NK) cell-activating receptors and their solid tumor surface ligands. Twenty-three human tumor cell lines (colon, breast, lung, head and neck, ovary, and bone sarcoma) were analyzed. NK effector cells were isolated from healthy donors, pre-treated with and without lenalidomide, and incubated with antibody-coated tumor cells to determine ADCC. In blocking experiments, NK cells were pre-incubated with anti-DNAM-1 or anti-NKG2D antibodies, and target colorectal cells were pre-incubated with anti-CD155 (PVR), anti-MIC-A/B, or anti-ULBP 3 antibodies. Differences between groups were assessed using unpaired and paired Student's t test and one-way ANOVA. Lenalidomide enhanced NK cell-mediated ADCC of trastuzumab- and cetuximab-coated tumor cells. Activity against colorectal cancer cells was dependent on target antigen expression, but independent of KRAS status and FcγRIIIa genotype. The extent of ADCC and its enhancement by lenalidomide correlated with NK cell expression of NKG2D and DNAM-1, and tumor cell expression of PVR and MIC-A. Blocking of NKG2D and, to a lesser extent, DNAM-1 inhibited ADCC. Anti-MIC-A/B monoclonal antibody blocked natural cytotoxicity, but not ADCC. Lenalidomide enhances the ability of IgG1-isotype antibodies to mediate ADCC of solid tumor cells, the extent of which is largely dependent on NKG2D-NKG2D ligand interactions, but appears to be independent of MIC-A/B. This provides a rationale for exploratory clinical studies and an assessment of potential biomarkers predictive of clinical benefit. PMID:20848094

  15. The role of the equatorial ligands for the redox behavior, mode of cellular accumulation and cytotoxicity of platinum(IV) prodrugs.

    PubMed

    Göschl, Simone; Varbanov, Hristo P; Theiner, Sarah; Jakupec, Michael A; Galanski, Markus; Keppler, Bernhard K

    2016-07-01

    The current study aims to elucidate the possible reasons for the significantly different pharmacological behavior of platinum(IV) complexes with cisplatin-, carboplatin- or nedaplatin-like cores and how this difference can be related to their main physicochemical properties. Chlorido-containing complexes are reduced fast (within hours) by ascorbate and are able to unwind plasmid DNA in the presence of ascorbate, while their tri- and tetracarboxylato analogs are generally inert under the same conditions. Comparison of the lipophilicity, cellular accumulation and cytotoxicity of the investigated platinum compounds revealed the necessity to define new structure-property/activity relationships (SPRs and SARs). The higher activity and improved accumulation of platinum(IV) complexes bearing Cl(-) in equatorial position cannot only be attributed to passive diffusion facilitated by their lipophilicity. Therefore, further platinum accumulation experiments under conditions where active/facilitated transport mechanisms are suppressed were performed. Under hypothermic conditions (4°C), accumulation of dichloridoplatinum(IV) complexes is reduced down to 10% of the amount determined at 37°C. These findings suggest the involvement of active and/or facilitated transport in cellular uptake of platinum(IV) complexes with a cisplatin-like core. Studies with ATP depletion mediated by oligomycin and low glucose partially confirmed these observations, but their feasibility was severely limited in the adherent cell culture setting. PMID:27055943

  16. Cellular Oxidative Stress and the Control of Apoptosis by Wild-Type p53, Cytotoxic Compounds, and Cytokines

    NASA Astrophysics Data System (ADS)

    Lotem, Joseph; Peled-Kamar, Mira; Groner, Yoram; Sachs, Leo

    1996-08-01

    Apoptosis induced by wild-type p53 or cytotoxic compounds in myeloid leukemic cells can be inhibited by the cytokines interleukin 6, interleukin 3, granulocyte-macrophage colony-stimulating factor, and interferon γ and by antioxidants. The antioxidants and cytokines showed a cooperative protective effect against induction of apoptosis. Cells with a higher sensitivity to induction of apoptosis and required a higher cytokine concentration to inhibit apoptosis. Decreasing the intrinsic oxidative stress in cells by antioxidants thus inhibited apoptosis, whereas increasing this intrinsic stress by adding H2O2 enhanced apoptosis. Induction of apoptosis by wild-type p53 was not preceded by increased peroxide production or lipid peroxidation and the protective effect of cytokines was not associated with a decrease in these properties. The results indicate that the intrinsic degree of oxidative stress can regulate cell susceptibility to wild-type p53-dependent and p53-independent induction of apoptosis and the ability of cytokines to protect cells against apoptosis.

  17. A Phase I Trial to Evaluate Antibody-Dependent Cellular Cytotoxicity of Cetuximab and Lenalidomide in Advanced Colorectal and Head and Neck Cancer.

    PubMed

    Bertino, Erin M; McMichael, Elizabeth L; Mo, Xiaokui; Trikha, Prashant; Davis, Melanie; Paul, Bonnie; Grever, Michael; Carson, William E; Otterson, Gregory A

    2016-09-01

    mAbs can induce antibody-dependent cellular cytotoxicity (ADCC) via the innate immune system's ability to recognize mAb-coated cancer cells and activate immune effector cells. Lenalidomide is an immunomodulatory agent with the capacity to stimulate immune cell cytokine production and ADCC activity. This phase I trial evaluated the combination of cetuximab with lenalidomide for the treatment of advanced colorectal and head and neck squamous cell cancers (HNSCC). This trial included patients with advanced colorectal cancer or HNSCC. Treatment consisted of cetuximab 500 mg/m(2) i.v. every two weeks with lenalidomide given orally days 1-21 on a 28-day cycle. Three dose levels of lenalidomide were evaluated (15, 20, 25 mg). Correlative studies included measurement of ADCC, FcγRIIIA polymorphism genotyping, measurement of serum cytokine levels, and flow cytometric analysis of immune cell subtypes. Twenty-two patients were enrolled (19 colorectal cancer, 3 HNSCC). Fatigue was the only dose-limiting toxicity. One partial response was observed and 8 patients had stable disease at least 12 weeks. The recommended phase II dose is cetuximab 500 mg/m(2) with lenalidomide 25 mg daily, days 1-21. Correlative studies demonstrated a dose-dependent increase in natural killer cytotoxic activity with increasing doses of lenalidomide. Cetuximab and lenalidomide were well tolerated. There was a lenalidomide dose-dependent increase in ADCC with higher activity in patients enrolled in cohort 3 than those enrolled in cohorts 1/2. Although response was not a primary endpoint, there was evidence of antitumor activity for the combination therapy. Further investigation of lenalidomide as an immunomodulator in solid tumors is warranted. Mol Cancer Ther; 15(9); 2244-50. ©2016 AACR. PMID:27458141

  18. Extensive expansion of primary human gamma delta T cells generates cytotoxic effector memory cells that can be labeled with Feraheme for cellular MRI.

    PubMed

    Siegers, Gabrielle M; Ribot, Emeline J; Keating, Armand; Foster, Paula J

    2013-03-01

    Gamma delta T cells (GDTc) comprise a small subset of cytolytic T cells shown to kill malignant cells in vitro and in vivo. We have developed a novel protocol to expand GDTc from human blood whereby GDTc were initially expanded in the presence of alpha beta T cells (ABTc) that were then depleted prior to use. We achieved clinically relevant expansions of up to 18,485-fold total GDTc, with 18,849-fold expansion of the Vδ1 GDTc subset over 21 days. ABTc depletion yielded 88.1 ± 4.2 % GDTc purity, and GDTc continued to expand after separation. Immunophenotyping revealed that expanded GDTc were mostly CD27-CD45RA- and CD27-CD45RA+ effector memory cells. GDTc cytotoxicity against PC-3M prostate cancer, U87 glioblastoma and EM-2 leukemia cells was confirmed. Both expanded Vδ1 and Vδ2 GDTc were cytotoxic to PC-3M in a T cell antigen receptor- and CD18-dependent manner. We are the first to label GDTc with ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles for cellular MRI. Using protamine sulfate and magnetofection, we achieved up to 40 % labeling with clinically approved Feraheme (Ferumoxytol), as determined by enumeration of Perls' Prussian blue-stained cytospins. Electron microscopy at 2,800× magnification verified the presence of internalized clusters of iron oxide; however, high iron uptake correlated negatively with cell viability. We found improved USPIO uptake later in culture. MRI of GDTc in agarose phantoms was performed at 3 Tesla. The signal-to-noise ratios for unlabeled and labeled cells were 56 and 21, respectively. Thus, Feraheme-labeled GDTc could be readily detected in vitro via MRI. PMID:23100099

  19. Impact of food components during in vitro digestion of silver nanoparticles on cellular uptake and cytotoxicity in intestinal cells.

    PubMed

    Lichtenstein, Dajana; Ebmeyer, Johanna; Knappe, Patrick; Juling, Sabine; Böhmert, Linda; Selve, Sören; Niemann, Birgit; Braeuning, Albert; Thünemann, Andreas F; Lampen, Alfonso

    2015-11-01

    Because of the rising application of nanoparticles in food and food-related products, we investigated the influence of the digestion process on the toxicity and cellular uptake of silver nanoparticles for intestinal cells. The main food components--carbohydrates, proteins and fatty acids--were implemented in an in vitro digestion process to simulate realistic conditions. Digested and undigested silver nanoparticle suspensions were used for uptake studies in the well-established Caco-2 model. Small-angle X-ray scattering was used to estimate particle core size, size distribution and stability in cell culture medium. Particles proved to be stable and showed radii from 3.6 to 16.0 nm. Undigested particles and particles digested in the presence of food components were comparably taken up by Caco-2 cells, whereas the uptake of particles digested without food components was decreased by 60%. Overall, these findings suggest that in vivo ingested poly (acrylic acid)-coated silver nanoparticles may reach the intestine in a nanoscaled form even if enclosed in a food matrix. While appropriate for studies on the uptake into intestinal cells, the Caco-2 model might be less suited for translocation studies. Moreover, we show that nanoparticle digestion protocols lacking food components may lead to misinterpretation of uptake studies and inconclusive results. PMID:26040006

  20. Cytotoxicity, cytocompatibility, cell-labeling efficiency, and in vitro cellular magnetic resonance imaging of gadolinium-catalyzed single-walled carbon nanotubes

    PubMed Central

    Avti, Pramod K.; Caparelli, Elisabeth D.; Sitharaman, Balaji

    2013-01-01

    Cell tracking by magnetic resonance imaging (MRI) is an emerging technique that typically requires the use of MRI contrast agents (CAs). A MRI CA for cellular imaging should label cells efficiently at potentially safe concentrations, have high relaxivity, and not affect the cellular machinery. In this article, we report the cytotoxicity, cytocompatibility, and cell labeling efficiency in NIH/3T3 fibroblasts of novel, single-walled carbon nanotubes synthesized using gadolinium nano-particles as catalysts (Gd-SWCNTs). Cells incubated with the Gd-SWCNT showed a dose- (50–100 μg/mL nanotube concentration) and time- (12–48 h) dependent decrease in viability. 30% cell death was observed for cells incubated with Gd-SWCNTs at the maximum dose of 100 μg/mL for 48 h. Cells incubated with the Gd-SWCNTs at concentrations between 1–10 μg/mL for 48 h showed no change in viability or proliferation compared to untreated controls. Additionally, at these potentially safe concentrations, up to 48 h, the cells showed no phosphatidyl serine externalization (pre-apoptotic condition), caspase-3 activity (point of no return for apoptosis), genetic damage, or changes in their division cycle. Localization of Gd-SWCNTs within the cells was confirmed by transmission electron microscopy (TEM) and Raman microscopy, and these results show 100% cell labeling efficiency. Elemental analysis also indicates significant uptake of Gd-SWCNTs by the cells (108–109 Gd3+ ions per cell). Finally, T1-weighted MRI at 3 T of Gd-SWCNT-labelled cells show up to a four-fold increase in MR signal intensities as compared to untreated cells. These results indicate that Gd-SWCNTs label cells efficiently at potentially safe concentrations, and enhance MRI contrast without any structural damage to the cells. PMID:23686792

  1. Interleukin-6 (IL-6) and IL-17 Synergistically Promote Viral Persistence by Inhibiting Cellular Apoptosis and Cytotoxic T Cell Function

    PubMed Central

    Hou, Wanqiu; Jin, Young-Hee; Kang, Hyun Seok

    2014-01-01

    ABSTRACT Interleukin-6 (IL-6) plays an important role in the development and progression of inflammatory responses, autoimmune diseases, and cancers. Many viral infections, including Theiler's murine encephalomyelitis virus (TMEV), result in the vigorous production of IL-6. However, the role of IL-6 in the development of virus-induced inflammatory responses is unclear. The infection of susceptible mice with TMEV induces the development of chronic demyelinating disease, which is considered a relevant infectious model for multiple sclerosis. In this study, we demonstrate that resistant C57BL/6 mice carrying an IL-6 transgene (IL-6 Tg) develop a TMEV-induced demyelinating disease accompanied by an increase in viral persistence and an elevated Th17 cell response in the central nervous system. Either IL-6 or IL-17 induced the expression of Bcl-2 and Bcl-xL at a high concentration. The upregulated expression of prosurvival molecules in turn inhibited target cell destruction by virus-specific CD8+ T cells. More interestingly, IL-6 and IL-17 synergistically promoted the expression of these prosurvival molecules, preventing cellular apoptosis at a much lower (<5-fold) concentration. The signals involved in the synergy appear to include the activation of both STAT3 and NF-κB via distinct cytokine-dependent pathways. Thus, the excessive IL-6 promotes the generation of Th17 cells, and the resulting IL-6 and IL-17 synergistically promote viral persistence by protecting virus-infected cells from apoptosis and CD8+ T cell-mediated target destruction. These results suggest that blocking both IL-6 and IL-17 functions are important considerations for therapies of chronic viral diseases, autoimmune diseases, and cancers. IMPORTANCE This study indicates that an excessive level of IL-6 cytokine produced following viral infection promotes the development of IL-17-producing pathogenic helper T cells. We demonstrate here for the first time that IL-6 together with IL-17 synergistically

  2. DNA binding, antioxidant, cytotoxicity (MTT, lactate dehydrogenase, NO), and cellular uptake studies of structurally different nickel(II) thiosemicarbazone complexes: synthesis, spectroscopy, electrochemistry, and X-ray crystallography.

    PubMed

    Prabhakaran, R; Kalaivani, P; Huang, R; Poornima, P; Vijaya Padma, V; Dallemer, F; Natarajan, K

    2013-02-01

    Three new nickel(II) thiosemicarbazone complexes have been synthesized and characterized by analytical, spectral, and single-crystal X-ray diffraction studies. In complex 1, the ligand 2-hydroxy-1-naphthaldehydethiosemicarbazone coordinated as a monobasic tridentate donor, whereas in complexes 2 and 3, the ligands salicylaldehyde-4(N)-ethylthiosemicarbazone and 2-hydroxy-1-naphthaldehyde-4(N)-ethylthiosemicarbazone coordinated as a dibasic tridentate donor. The DNA binding ability of the complexes in calf thymus DNA was explored by absorption and emission titration experiments. The antioxidant property of the new complexes was evaluated to test their free-radical scavenging ability. In vitro cytotoxicity assays were performed for the new complexes in A549 and HepG2 cell lines. The new compounds overcome cisplatin resistance in the A549 cell line and they were also active in the HepG2 cell line. The cellular uptake study showed the accumulation of the complexes in tumor cells depended on the nature of the ligand attached to the nickel ion. PMID:23274397

  3. Spontaneous and antibody-dependent cellular cytotoxicity by lymphocyte subpopulations in peripheral blood and spleen from adult untreated patients with Hodgkin's disease.

    PubMed Central

    Gupta, S; Fernandes, G

    1981-01-01

    Subpopulations of lymphocytes in the peripheral blood and spleen from adult untreated patients with Hodgkin's disease were studied for spontaneous (SCMC) and antibody-dependent cellular cytotoxicities (ADCC). Peripheral blood from seven of 24 patients demonstrated abnormally low T cell-mediated SCMC when compared to age- and sex-matched healthy controls. Only two of these patients also demonstrated low T cell ADCC and non-T cell-mediated SCMC and ADCC. T cell ADCC in the peripheral blood of patients with involved spleen was significantly higher (P less than 0.05) when compared to those in whom spleen was not involved. When SCMC and ADCC were compared between peripheral blood and splenic lymphocytes with regard to involvement of spleen by Hodgkin's disease, non-T cell SCMC in the involved spleen was significantly lower (P less than 0.05) than their peripheral blood non-T cell SCMC. SCMC and ADCC tended to be higher in patients with stages III and IV of Hodgkin's disease when compared to those with stages I and II. However, the differences were not statistically significant. No direct relationship was observed between T and SCMC or ADCC and the proportion of T cells with IgG Fc receptors (T gamma). The significance of these observations is discussed. PMID:6975681

  4. Anti-CS1 humanized monoclonal antibody HuLuc63 inhibits myeloma cell adhesion and induces antibody-dependent cellular cytotoxicity in the bone marrow milieu.

    PubMed

    Tai, Yu-Tzu; Dillon, Myles; Song, Weihua; Leiba, Merav; Li, Xian-Feng; Burger, Peter; Lee, Alfred I; Podar, Klaus; Hideshima, Teru; Rice, Audie G; van Abbema, Anne; Jesaitis, Lynne; Caras, Ingrid; Law, Debbie; Weller, Edie; Xie, Wanling; Richardson, Paul; Munshi, Nikhil C; Mathiot, Claire; Avet-Loiseau, Hervé; Afar, Daniel E H; Anderson, Kenneth C

    2008-08-15

    Currently, no approved monoclonal antibody (mAb) therapies exist for human multiple myeloma (MM). Here we characterized cell surface CS1 as a novel MM antigen and further investigated the potential therapeutic utility of HuLuc63, a humanized anti-CS1 mAb, for treating human MM. CS1 mRNA and protein was highly expressed in CD138-purified primary tumor cells from the majority of MM patients (more than 97%) with low levels of circulating CS1 detectable in MM patient sera, but not in healthy donors. CS1 was expressed at adhesion-promoting uropod membranes of polarized MM cells, and short interfering RNA (siRNA) targeted to CS1 inhibited MM cell adhesion to bone marrow stromal cells (BMSCs). HuLuc63 inhibited MM cell binding to BMSCs and induced antibody-dependent cellular cytotoxicity (ADCC) against MM cells in dose-dependent and CS1-specific manners. HuLuc63 triggered autologous ADCC against primary MM cells resistant to conventional or novel therapies, including bortezomib and HSP90 inhibitor; and pretreatment with conventional or novel anti-MM drugs markedly enhanced HuLuc63-induced MM cell lysis. Administration of HuLuc63 significantly induces tumor regression in multiple xenograft models of human MM. These results thus define the functional significance of CS1 in MM and provide the preclinical rationale for testing HuLuc63 in clinical trials, either alone or in combination. PMID:17906076

  5. Long-term preservation of antibody-dependent cellular cytotoxicity (ADCC) of natural killer cells amplified in vitro from the peripheral blood of breast cancer patients after chemotherapy.

    PubMed

    Clémenceau, Béatrice; Gallot, Géraldine; Vivien, Régine; Gaschet, Joëlle; Campone, Mario; Vié, Henri

    2006-01-01

    Twenty percent of breast cancer adenocarcinomas overexpress the oncogene c-erb-2 that is recognized by the humanized anti-Her2/neu monoclonal antibody Herceptin. Results from clinical studies suggest that antibody-dependent cellular cytotoxicity (ADCC) is involved in the clinical response of Herceptin-treated patients. The purpose of the current study was to evaluate the possibility of amplifying in vitro the CD3-/CD16+ natural killer (NK) cell subset that mediates ADCC from breast cancer patients after chemotherapy. Peripheral blood mononuclear cells from six breast cancer patients taken 2 months after chemotherapy completion were co-cultured with an autologous irradiated Epstein-Barr virus-transformed B-lymphoblastoid cell line (LCL) in the presence of interleukin-2 (IL-2) for 4-6 weeks. These LCL + IL2 activated cultures (ACs) were tested for ADCC potential, and their CD3/CD16 NK proportion was quantified. Among the ACs, the proportion of CD3-/CD16+ NK cells increased up to 64% over the first 2 weeks of culture and the ACs continued to expand for 1 month thereafter. Control and patient ACs displayed ADCC activity (tested in the presence of Rituximab against the autologous LCL to take into account any possible effect of inhibitory NK receptors) as well as against the MCF-7(Her2/neu) breast cancer cell line in the presence of Herceptin. This ADCC activity was maintained during the entire culture period. In conclusion, chemotherapy in breast cancer patients does not obviate the possibility of amplifying in vitro the NK cell subset that mediates ADCC. Consequently, adoptive transfer of lymphocytes mediating ADCC can be considered using this protocol to test its benefit in patients under Herceptin treatment. PMID:16365600

  6. High concentrations of therapeutic IgG1 antibodies are needed to compensate for inhibition of antibody-dependent cellular cytotoxicity by excess endogenous immunoglobulin G.

    PubMed

    Preithner, Susanne; Elm, Stefanie; Lippold, Sandra; Locher, Mathias; Wolf, Andreas; da Silva, Antonio J; Baeuerle, Patrick A; Prang, Nadja S

    2006-03-01

    A common feature of human IgG1 antibodies used for cancer treatment is that their anti-tumour efficacy requires high serum trough levels and continued therapy for several months. Treatment cycles, thereby, consume several grams of IgG1 translating into significant drug needs and costs. The basis for the low in vivo efficacy, which is in contrast to high in vitro antibody-dependent cellular cytotoxicity (ADCC), is not well understood. Here, we have explored factors contributing to this discrepancy using adecatumumab (MT201), a fully human monoclonal IgG1 against epithelial cell adhesion molecule (Ep-CAM) and trastuzumab (Herceptin), a humanized IgG1 with specificity for the human epithelial growth factor receptor type 2 (HER-2) antigen. We found that physiological levels of human sera strongly inhibited ADCC of both IgG1 antibodies. Effects showed some dependence on the density of Ep-CAM and HER-2 targets, the tumour cell line tested and on effector cell and serum donors. Removal of IgG by affinity chromatography abolished the inhibitory effect of a serum pool. Inhibition of ADCC was fully restored by adding back the IgG fraction or by an equal amount of IgG from a commercial source. We further demonstrate that CD56-positive lymphocytes within human PBMC contributed >90% to ADCC and that normal serum levels of IgG effectively competed for in vitro binding of an IgG1 antibody to low-affinity Fcgamma receptor type III (CD16), as is present on natural killer (NK) cells. Competition of serum IgG for binding of therapeutic IgG1 to NK cell may be one important reason why high antibody doses are required in the clinic for treatment of cancer by an ADCC-based mechanism. PMID:16102830

  7. miR-143 or miR-145 overexpression increases cetuximab-mediated antibody-dependent cellular cytotoxicity in human colon cancer cells

    PubMed Central

    Gomes, Sofia E.; Simões, André E. S.; Pereira, Diane M.; Castro, Rui E.; Rodrigues, Cecília M. P.; Borralho, Pedro M.

    2016-01-01

    miR-143 and miR-145 are downregulated in colon cancer. Here, we tested the effect of restoring these miRNAs on sensitization to cetuximab in mutant KRAS (HCT116 and SW480) and wild-type KRAS (SW48) colon cancer cells. We evaluated cetuximab-mediated antibody-dependent cellular cytotoxicity (ADCC) and the modulation of signaling pathways involved in immune effector cell-mediated elimination of cancer cells. Stable miR-143 or miR-145 overexpression increased cell sensitivity to cetuximab, resulting in a significant increase of cetuximab-mediated ADCC independently of KRAS status. Importantly, HCT116 cells overexpressing these miRNAs triggered apoptosis in result of cetuximab-mediated ADCC, effected by peripheral blood mononuclear cells (p < 0.01). This was associated with increased apoptosis and caspase-3/7 activity, and reduced Bcl-2 protein expression (p < 0.01). In addition, caspase inhibition abrogated cetuximab-mediated ADCC in HCT116 cells overexpressing either miR-143 or miR-145 (p < 0.01). Furthermore, Bcl-2 silencing led to high level of cetuximab-mediated ADCC, compared to control siRNA (p < 0.05). Importantly, granzyme B inhibition, abrogated cetuximab-mediated ADCC, reducing caspase-3/7 activity (p < 0.01). Collectively, our data suggests that re-introduction of miR-143 or miR-145 may provide a new approach for development of therapeutic strategies to re-sensitize colon cancer cells to cetuximab by stimulating cetuximab-dependent ADCC to induce cell death. PMID:26824186

  8. Antibody-Dependent Cellular Cytotoxicity-Mediating Antibodies from an HIV-1 Vaccine Efficacy Trial Target Multiple Epitopes and Preferentially Use the VH1 Gene Family

    PubMed Central

    Pollara, Justin; Moody, M. Anthony; Alpert, Michael D.; Chen, Xi; Hwang, Kwan-Ki; Gilbert, Peter B.; Huang, Ying; Gurley, Thaddeus C.; Kozink, Daniel M.; Marshall, Dawn J.; Whitesides, John F.; Tsao, Chun-Yen; Kaewkungwal, Jaranit; Nitayaphan, Sorachai; Pitisuttithum, Punnee; Rerks-Ngarm, Supachai; Kim, Jerome H.; Michael, Nelson L.; Tomaras, Georgia D.; Montefiori, David C.; Lewis, George K.; DeVico, Anthony; Evans, David T.; Ferrari, Guido; Liao, Hua-Xin; Haynes, Barton F.

    2012-01-01

    The ALVAC-HIV/AIDSVAX-B/E RV144 vaccine trial showed an estimated efficacy of 31%. RV144 secondary immune correlate analysis demonstrated that the combination of low plasma anti-HIV-1 Env IgA antibodies and high levels of antibody-dependent cellular cytotoxicity (ADCC) inversely correlate with infection risk. One hypothesis is that the observed protection in RV144 is partially due to ADCC-mediating antibodies. We found that the majority (73 to 90%) of a representative group of vaccinees displayed plasma ADCC activity, usually (96.2%) blocked by competition with the C1 region-specific A32 Fab fragment. Using memory B-cell cultures and antigen-specific B-cell sorting, we isolated 23 ADCC-mediating nonclonally related antibodies from 6 vaccine recipients. These antibodies targeted A32-blockable conformational epitopes (n = 19), a non-A32-blockable conformational epitope (n = 1), and the gp120 Env variable loops (n = 3). Fourteen antibodies mediated cross-clade target cell killing. ADCC-mediating antibodies displayed modest levels of V-heavy (VH) chain somatic mutation (0.5 to 1.5%) and also displayed a disproportionate usage of VH1 family genes (74%), a phenomenon recently described for CD4-binding site broadly neutralizing antibodies (bNAbs). Maximal ADCC activity of VH1 antibodies correlated with mutation frequency. The polyclonality and low mutation frequency of these VH1 antibodies reveal fundamental differences in the regulation and maturation of these ADCC-mediating responses compared to VH1 bNAbs. PMID:22896626

  9. Antibody-dependent cellular cytotoxicity-mediating antibodies from an HIV-1 vaccine efficacy trial target multiple epitopes and preferentially use the VH1 gene family.

    PubMed

    Bonsignori, Mattia; Pollara, Justin; Moody, M Anthony; Alpert, Michael D; Chen, Xi; Hwang, Kwan-Ki; Gilbert, Peter B; Huang, Ying; Gurley, Thaddeus C; Kozink, Daniel M; Marshall, Dawn J; Whitesides, John F; Tsao, Chun-Yen; Kaewkungwal, Jaranit; Nitayaphan, Sorachai; Pitisuttithum, Punnee; Rerks-Ngarm, Supachai; Kim, Jerome H; Michael, Nelson L; Tomaras, Georgia D; Montefiori, David C; Lewis, George K; DeVico, Anthony; Evans, David T; Ferrari, Guido; Liao, Hua-Xin; Haynes, Barton F

    2012-11-01

    The ALVAC-HIV/AIDSVAX-B/E RV144 vaccine trial showed an estimated efficacy of 31%. RV144 secondary immune correlate analysis demonstrated that the combination of low plasma anti-HIV-1 Env IgA antibodies and high levels of antibody-dependent cellular cytotoxicity (ADCC) inversely correlate with infection risk. One hypothesis is that the observed protection in RV144 is partially due to ADCC-mediating antibodies. We found that the majority (73 to 90%) of a representative group of vaccinees displayed plasma ADCC activity, usually (96.2%) blocked by competition with the C1 region-specific A32 Fab fragment. Using memory B-cell cultures and antigen-specific B-cell sorting, we isolated 23 ADCC-mediating nonclonally related antibodies from 6 vaccine recipients. These antibodies targeted A32-blockable conformational epitopes (n = 19), a non-A32-blockable conformational epitope (n = 1), and the gp120 Env variable loops (n = 3). Fourteen antibodies mediated cross-clade target cell killing. ADCC-mediating antibodies displayed modest levels of V-heavy (VH) chain somatic mutation (0.5 to 1.5%) and also displayed a disproportionate usage of VH1 family genes (74%), a phenomenon recently described for CD4-binding site broadly neutralizing antibodies (bNAbs). Maximal ADCC activity of VH1 antibodies correlated with mutation frequency. The polyclonality and low mutation frequency of these VH1 antibodies reveal fundamental differences in the regulation and maturation of these ADCC-mediating responses compared to VH1 bNAbs. PMID:22896626

  10. Multiple low-dose streptozotocin-induced diabetes in the mouse. Evidence for stimulation of a cytotoxic cellular immune response against an insulin-producing beta cell line.

    PubMed Central

    McEvoy, R C; Andersson, J; Sandler, S; Hellerström, C

    1984-01-01

    Mice were examined for the presence of splenocytes specifically cytotoxic for a rat insulinoma cell line (RIN) during the induction of diabetes by streptozotocin (SZ) in multiple low doses (Multi-Strep). Cytotoxicity was quantitated by the release of 51Cr from damaged cells. A low but statistically significant level of cytolysis (5%) by splenocytes was first detectable on day 8 after the first dose of SZ. The cytotoxicity reached a maximum of approximately 9% on day 10 and slowly decreased thereafter, becoming undetectable 42 d after SZ was first given. The time course of the in vitro cytotoxic response correlated with the degree of insulitis demonstrable in the pancreata of the Multi-Strep mice. The degree of cytotoxicity after Multi-Strep was related to the number of effector splenocytes to which the target RIN cells were exposed and was comparable to that detectable after immunization by intraperitoneal injection of RIN cells in normal mice. The cytotoxicity was specific for insulin-producing cells; syngeneic, allogeneic, and xenogeneic lymphocytes and lymphoblasts, 3T3 cells, and a human keratinocyte cell line were not specifically lysed by the splenocytes of the Multi-Strep mice. This phenomenon was limited to the Multi-Strep mice. Splenocytes from mice made diabetic by a single, high dose of SZ exhibited a very low level of cytotoxicity against the RIN cells. The cytotoxic response was also quantitated in splenocytes from control and Multi-Strep mice (10 d after the first dose of SZ) before and after culture with mitomycin-treated RIN cells in the presence of T cell growth factor (TCGF). The cytotoxicity of the Multi-Strep splenocytes was enhanced more than fivefold after such culture, suggesting the proliferation of an effector cell that could be stimulated and supported in vitro by TCGF. These results support the hypothesis that cell-mediated anti-beta cell autoimmunity may play a role in the destruction of the beta cells in this animal model. The

  11. Differential modulation of the lipid metabolism as a model for cellular resistance to fumonisin B1-induced cytotoxic effects in vitro.

    PubMed

    Riedel, S; Abel, S; Burger, H-M; van der Westhuizen, L; Swanevelder, S; Gelderblom, W C A

    2016-06-01

    Differential sensitivity of primary hepatocytes and Chang cells to the cancer promoter fumonisin B1 (FB1)-induced cytotoxic effects were investigated in relation to changes in membrane lipid distribution. In contrast to primary hepatocytes, Chang cells were resistant to FB1-induced cytotoxic effects. This was associated with a high cholesterol (Chol) and sphingomyelin (SM) and low phosphatidylcholine (PC) content, resulting in a significant (P<0.05) decrease in phosphatidylethanolamine (PE)/PC ratio, increased Chol/total phosphoglyceride (TPG) ratios and low total polyunsaturated fatty acids (PUFA) content in PC and PE, suggesting a more rigid membrane structure. High levels of C18:1 and reduced polyunsaturated fatty acid (PUFA) levels are likely to provide selective resistance to FB1-induced oxidative stress. FB1-associated lipid changes included decreases in SM and Chol, increases in sphinganine (Sa) and PE with the increases in key saturated, monounsaturated, and PUFAs in PE as key role players in the differential responses to FB1-induced cell growth responses in cells. PMID:27269712

  12. Camptothecin-Loaded Liposomes with α-Melanocyte-Stimulating Hormone Enhance Cytotoxicity Toward and Cellular Uptake by Melanomas: An Application of Nanomedicine on Natural Product

    PubMed Central

    Lin, Chih-Hung; Al-Suwayeh, Saleh A.; Hung, Chih-Feng; Chen, Chih-Chieh; Fang, Jia-You

    2013-01-01

    In this study, we attempted to develop functional liposomes loaded with camptothecin and attached to α-melanocyte-stimulating hormone (α-MSH) to target melanoma cells. The liposomes were mainly composed of phosphatidylcholine, cholesterol, and stearylamine, and were characterized by the vesicle size, zeta potential, camptothecin encapsulation efficiency, and release behavior. Results revealed that α-MSH liposomes possessed an average size of approximately 250 nm with a surface charge of 60 mV. Camptothecin was successfully entrapped by the targeted liposomes with an encapsulation percentage of nearly 95%. The liposomes provided sustained and controlled camptothecin release. Non-targeted liposomes with the drug exerted superior cytotoxicity against melanomas compared to the free control. Cell viability was reduced from 48% to 32% compared to conventional liposomes. Peptide ligand conjugation further promoted cytotoxicity to 18% viability, which was a 2.7-fold decrease versus the free control. According to the images of fluorescence microscopy, α-MSH liposomes exhibited greater cell endocytosis than did non-targeted liposomes and the free control. α-MSH liposomes were predominantly internalized in the cytoplasm. These findings demonstrate that α-MSH liposomes could enhance the anti-melanoma activity of camptothecin owing to their targeting ability and controlled drug delivery. PMID:24716164

  13. Cellular Adjuvant Properties, Direct Cytotoxicity of Re-differentiated Vα24 Invariant NKT-like Cells from Human Induced Pluripotent Stem Cells

    PubMed Central

    Kitayama, Shuichi; Zhang, Rong; Liu, Tian-Yi; Ueda, Norihiro; Iriguchi, Shoichi; Yasui, Yutaka; Kawai, Yohei; Tatsumi, Minako; Hirai, Norihito; Mizoro, Yasutaka; Iwama, Tatsuaki; Watanabe, Akira; Nakanishi, Mahito; Kuzushima, Kiyotaka; Uemura, Yasushi; Kaneko, Shin

    2016-01-01

    Summary Vα24 invariant natural killer T (iNKT) cells are a subset of T lymphocytes implicated in the regulation of broad immune responses. They recognize lipid antigens presented by CD1d on antigen-presenting cells and induce both innate and adaptive immune responses, which enhance effective immunity against cancer. Conversely, reduced iNKT cell numbers and function have been observed in many patients with cancer. To recover these numbers, we reprogrammed human iNKT cells to pluripotency and then re-differentiated them into regenerated iNKT cells in vitro through an IL-7/IL-15-based optimized cytokine combination. The re-differentiated iNKT cells showed proliferation and IFN-γ production in response to α-galactosylceramide, induced dendritic cell maturation and downstream activation of both cytotoxic T lymphocytes and NK cells, and exhibited NKG2D- and DNAM-1-mediated NK cell-like cytotoxicity against cancer cell lines. The immunological features of re-differentiated iNKT cells and their unlimited availability from induced pluripotent stem cells offer a potentially effective immunotherapy against cancer. PMID:26862702

  14. Augmentation of natural killer cell and antibody-dependent cellular cytotoxicity in BALB/c mice by sulforaphane, a naturally occurring isothiocyanate from broccoli through enhanced production of cytokines IL-2 and IFN-gamma.

    PubMed

    Thejass, P; Kuttan, G

    2006-01-01

    Effect of sulforaphane on cell-mediated immune (CMI) response was studied in normal as well as Ehrlich ascites tumor-bearing BALB/c mice. Administration of sulforaphane significantly enhanced natural killer (NK) cell activity in both normal as well as tumor-bearing animals, and the activity was observed earlier than in tumor-bearing control animals. Antibody-dependent cellular cytotoxicity (ADCC) also was enhanced significantly in both normal as well as tumor-bearing animals after sulforaphane administration compared with untreated control tumor-bearing animals. An early antibody-dependent complement-mediated cytotoxicity (ACC) also was observed in sulforaphane-treated normal and tumor-bearing animals. Administration of sulforaphane significantly enhanced the production of Interleukin-2 and Interferon-gamma in normal as well as tumor-bearing animals. In addition, sulforaphane significantly enhanced the proliferation of splenocytes, bone marrow cells, and thymocytes by stimulating the mitogenic potential of various mitogens such as concanavalin A, phytohaemagglutinin, poke weed mitogen, and lipopolysaccharide. PMID:16997793

  15. Does photocatalytic activity of TiO2 nanoparticles correspond to photo-cytotoxicity? Cellular uptake of TiO2 nanoparticles is important in their photo-cytotoxicity.

    PubMed

    Horie, Masanori; Sugino, Sakiko; Kato, Haruhisa; Tabei, Yosuke; Nakamura, Ayako; Yoshida, Yasukazu

    2016-05-01

    Titanium dioxide (TiO2) nanoparticles are important industrial nano-objects with wide applications, including as photocatalysts and sunscreen components. Recently, the phototoxicity of TiO2 nanoparticles has been a concern. However, phototoxicity caused by photocatalytic activity may differ between anatase and rutile nanoparticles. In the present study, we compared the phototoxicity of anatase and rutile nanoparticles. Human keratinocyte HaCaT cells were treated with stable TiO2 nanoparticle suspensions. Without UVA irradiation, TiO2 nanoparticles did not affect mitochondrial activity or cell membranes. However, exposure to rutile nanoparticle suspensions inhibited cell growth and induced HO-1 gene expression without UVA irradiation. These effects may be explained by the hydrophobic surface of rutile nanoparticles. Next, TiO2-exposed cells were irradiated with UVA for 4 h and effects of TiO2 nanoparticles on cells were examined. The rutile nanoparticles did not show any cellular effects after UVA irradiation. However, the anatase nanoparticles caused strong phototoxicity. Decreased mitochondrial activity, cell membrane damage and the induction of oxidative stress were observed in the cells exposed to anatase nanoparticles with UVA irradiation. Cellular uptake of the nanoparticles was observed in both anatase- and rutile-exposed cells. These results suggest that internalized anatase nanoparticles are important for phototoxicity. Additionally, the exposure of a 3D skin model to TiO2 nanoparticles did not result in significant toxicity. In conclusion, rutile nanoparticles used in sunscreen did not exhibit phototoxic activity. Despite the strong phototoxic activity of anatase nanoparticles in cell cultures, they demonstrated no phototoxicity using a 3D skin model. PMID:27142467

  16. Cytotoxicity and expression of genes involved in the cellular stress response and apoptosis in mammalian fibroblast exposed to cotton cellulose nanofibers

    NASA Astrophysics Data System (ADS)

    Pereira, M. M.; Raposo, N. R. B.; Brayner, R.; Teixeira, E. M.; Oliveira, V.; Quintão, C. C. R.; Camargo, L. S. A.; Mattoso, L. H. C.; Brandão, H. M.

    2013-02-01

    Cellulose nanofibers (CNF) have mechanical properties that make them very attractive for applications in the construction of polymeric matrices, drug delivery and tissue engineering. However, little is known about their impact on mammalian cells. The objective of this study was to evaluate the cytotoxicity of CNF and their effect on gene expression of fibroblasts cultured in vitro. The morphology of CNF was analyzed by transmission electron microscopy and the surface charge by Zeta potential. Cell viability was analyzed by flow cytometry assay and gene expression of biomarkers focused on cell stress response such as Heat shock protein 70.1 (HSP70.1) and Peroxiredoxin 1 (PRDX1) and apoptosis as B-cell leukemia (BCL-2) and BCL-2 associated X protein (BAX) by RT-PCR assay. Low concentrations of CNF (0.02-100 μg ml-1) did not cause cell death; however, at concentrations above 200 μg ml-1, the nanofibers significantly decreased cell viability (86.41 ± 5.37%). The exposure to high concentrations of CNF (2000 and 5000 μg ml-1) resulted in increased HSP70.1, PRDX1 and BAX gene expression. The current study concludes that, under the conditions tested, high concentrations (2000 and 5000 μg ml-1) of CNF cause decreased cell viability and affect the expression of stress- and apoptosis-associated molecular markers.

  17. Combined use of anti-ErbB monoclonal antibodies and erlotinib enhances antibody-dependent cellular cytotoxicity of wild-type erlotinib-sensitive NSCLC cell lines

    PubMed Central

    2012-01-01

    Background The epidermal growth factor receptor (EGFR) is an established target for anti-cancer treatment in different tumour types. Two different strategies have been explored to inhibit this pivotal molecule in epithelial cancer development: small molecules TKIs and monoclonal antibodies. ErbB/HER-targeting by monoclonal antibodies such as cetuximab and trastuzumab or tyrosine-kinase inhibitors as gefitinib or erlotinib has been proven effective in the treatment of advanced NSCLC. Results In this study we explored the potential of combining either erlotinib with cetuximab or trastuzumab to improve the efficacy of EGFR targeted therapy in EGFR wild-type NSCLC cell lines. Erlotinib treatment was observed to increase EGFR and/or HER2 expression at the plasma membrane level only in NSCLC cell lines sensitive to the drug inducing protein stabilization. The combined treatment had marginal effect on cell proliferation but markedly increased antibody-dependent, NK mediated, cytotoxicity in vitro. Moreover, in the Calu-3 xenograft model, the combination significantly inhibited tumour growth when compared with erlotinib and cetuximab alone. Conclusion Our results indicate that erlotinib increases surface expression of EGFR and/or HER2 only in EGFR-TKI sensitive NSCLC cell lines and, in turns, leads to increased susceptibility to ADCC both in vitro and in a xenograft models. The combination of erlotinib with monoclonal antibodies represents a potential strategy to improve the treatment of wild-type EGFR NSCLC patients sensitive to erlotinib. PMID:23234355

  18. Characterization and cellular localization of nucleophosmin/B23 in HeLa cells treated with selected cytotoxic agents (studies of B23-translocation mechanism).

    PubMed

    Chan, P K

    1992-11-01

    Previous studies indicated that nucleophosmin/B23, an abundant nucleolar phosphoprotein, accumulated in the nucleoplasm (B23-translocation) of cells after exposure to selected cytotoxic drugs. Attempts were made to understand the B23-translocation mechanism. This paper reports that: (1) B23-translocation is a reversible process. Upon removal of camptothecin, which induced B23-translocation in HeLa cells, nucleophosmin/B23 relocalized into nucleoli within 2 h. Relocation occurs in the presence of cycloheximide which inhibits new protein synthesis. There is no reduction or degradation of nucleophosmin/B23 detected during drug treatments. Nucleophosmin/B23 has a half-life of 18-20 h. Taken together, these results indicate that B23-translocation is a reversible process. Drug treatment causes redistribution of nucleophosmin/B23 in nucleoplasm. (2) Inhibition of RNA synthesis does not cause the B23-translocation. Over 80% of RNA synthesis was inhibited in HeLa cells by treatment with actinomycin D, camptothecin, and methotrexate. While actinomycin D and camptothecin cause B23-translocation in all cells, 40% of methotrexate-treated cells remain untranslocated. (3) There is no significant change of phosphorylation in nucleophosmin/B23 during drug treatment. An identical oligomeric cross-linkage pattern was obtained in drug-treated cells. (4) HeLa cells treated with B23-translocation effective drugs have small and round nucleoli while control cells have large and irregular-shaped nucleoli. PMID:1426041

  19. Preparation and evaluation of charged solid lipid nanoparticles of tetrandrine for ocular drug delivery system: pharmacokinetics, cytotoxicity and cellular uptake studies.

    PubMed

    Li, Jiawei; Guo, Xiujun; Liu, Zhidong; Okeke, Chukwunweike Ikechukwu; Li, Nan; Zhao, Hainan; Aggrey, Mike Okweesi; Pan, Weisan; Wu, Tao

    2014-07-01

    In this study, tetrandrine-loaded cationic solid lipid nanoparticles (TET-CNP) and solid lipid nanoparticles (TET-NP) were prepared by the emulsion evaporation-solidification at low temperature method. The particle size, zeta potential, and entrapment efficiency of TET-CNP and TET-NP were characterized. The results showed that the TET-CNP and TET-NP had average diameters of (15.29 ± 1.34) nm and (18.77 ± 1.23) nm with zeta potentials of (5.11 ± 1.03) mV and (-8.71 ± -1.23) mV and entrapment efficiencies of (94.1 ± 2.37)% and (95.6 ± 2.43)%, respectively. In vitro release studies indicated that the TET-CNP and TET-NP retained the drug entity better than tetrandrine ophthalmic solutions (TET-SOL). In the pharmacokinetics studies, the AUC values of TET-CNP and TET-NP were 1.96-fold and 2.00-fold higher than that of TET-SOL ( p < 0.05); the Cmax values of TET-CNP and TET-NP were 2.45-fold and 2.53-fold higher than that of the TET-SOL (p < 0.05), respectively. Cytotoxicity study showed that TET-CNP and TET-NP had no significant toxicity at low concentrations. Flow cytometry studies and confocal microscopy analysis demonstrated that calcein labeled NP (CA-NP) uptake by SRA 01/04 cells was much higher than those of calcein labeled CNP (CA-CNP) and calcein solution (CA-SOL). PMID:23662696

  20. Synthesis, DNA binding, cellular DNA lesion and cytotoxicity of a series of new benzimidazole-based Schiff base copper(II) complexes.

    PubMed

    Paul, Anup; Anbu, Sellamuthu; Sharma, Gunjan; Kuznetsov, Maxim L; Koch, Biplob; Guedes da Silva, M Fátima C; Pombeiro, Armando J L

    2015-12-14

    A series of new benzimidazole containing compounds 2-((1-R-1-H-benzimidazol-2-yl)phenyl-imino)naphthol HL(1-3) (R = methyl, ethyl or propyl, respectively) have been synthesized by Schiff base condensation of 2-(1-R-1-H-benzo[d]imidazol-2-yl)aniline and 2-hydroxy-1-naphthaldehyde. The reactions of HL(1-3) with Cu(NO3)2·2.5H2O led to the corresponding copper(II) complexes [Cu(L)(NO3)] 1-3. All the compounds were characterized by conventional analytical techniques and, for 1 and 3, also by single-crystal X-ray analysis. The interactions of complexes 1-3 with calf thymus DNA were studied by absorption and fluorescence spectroscopic techniques and the calculated binding constants (K(b)) are in the range of 3.5 × 10(5) M(-1)-3.2 × 10(5) M(-1). Complexes 1-3 effectively bind DNA through an intercalative mode, as proved by molecular docking studies. The binding affinity of the complexes decreases with the size increase of the N-alkyl substituent, in the order of 1 > 2 > 3, which is also in accord with the calculated LUMO(complex) energies. They show substantial in vitro cytotoxic effect against human lung (A-549), breast (MDA-MB-231) and cervical (HeLa) cancer cell lines. Complex 1 exhibits a significant inhibitory effect on the proliferation of the A-549 cancer cells. The antiproliferative efficacy of 1 has also been analysed by a DNA fragmentation assay, fluorescence activated cell sorting (FACS) and nuclear morphology using a fluorescence microscope. The possible mode for the apoptosis pathway of 1 has also been evaluated by a reactive oxygen species (ROS) generation study. PMID:26523453

  1. Real-time analysis of the detailed sequence of cellular events in mAb-mediated complement-dependent cytotoxicity of B-cell lines and of chronic lymphocytic leukemia B-cells.

    PubMed

    Lindorfer, Margaret A; Cook, Erika M; Tupitza, Jillian C; Zent, Clive S; Burack, Richard; de Jong, Rob N; Beurskens, Frank J; Schuurman, Janine; Parren, Paul W H I; Taylor, Ronald P

    2016-02-01

    Complement-dependent cytotoxicity is an important mechanism of action of certain mAbs used in cancer immunotherapy, including ofatumumab and rituximab. However, the detailed sequence of cellular changes that occur in nucleated cells attacked by mAb and complement has not been delineated. Recently developed CD20 mAbs, engineered to form hexamers on binding to cells, react with B-cells in serum, chelate C1q, and then activate complement and promote cell killing considerably more effectively than their wild-type precursors. We used these engineered mAbs as a model to investigate the sequence of events that occur when mAbs bind to B-cell lines and to primary cells from patients with chronic lymphocytic leukemia and then activate complement. Based on four-color confocal microscopy real-time movies and high resolution digital imaging, we find that after CD20 mAb binding and C1q uptake, C3b deposits on cells, followed by Ca(2+) influx, revealed by bright green signals generated on cells labeled with FLUO-4, a Ca(2+) indicator. The bright FLUO-4/Ca(2+) signal fades, replaced by punctate green signals in mitochondria, indicating Ca(2+) localization. This step leads to mitochondrial poisoning followed by cell death. The entire sequence is completed in <2 min for hexamerization-enhanced CD20 mAb-mediated killing. To our knowledge this is the first time the entire process has been characterized in detail in real time. By identifying multiple discrete steps in the cytotoxic pathway for nucleated cells our findings may inform future development and more effective application of complement-fixing mAbs to cancer treatment. PMID:26690706

  2. Evaluation of in-vitro cytotoxicity and cellular uptake efficiency of zidovudine-loaded solid lipid nanoparticles modified with Aloe Vera in glioma cells.

    PubMed

    K S, Joshy; Sharma, Chandra P; Kalarikkal, Nandakumar; Sandeep, K; Thomas, Sabu; Pothen, Laly A

    2016-09-01

    Zidovudine loaded solid lipid nanoparticles of stearic acid modified with Aloe Vera (AV) have been prepared via simple emulsion solvent evaporation method which showed excellent stability at room temperature and refrigerated condition. The nanoparticles were examined by Fourier transform infrared spectroscopy (FT-IR), which revealed the overlap of the AV absorption peak with the absorption peak of modified stearic acid nanoparticles. The inclusion of AV to stearic acid decreased the crystallinity and improved the hydrophilicity of lipid nanoparticles and thereby improved the drug loading efficacy of lipid nanoparticles. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) imaging revealed that, the average particle size of unmodified (bare) nanoparticles was 45.66±12.22nm and modified solid lipid nanoparticles showed an average size of 265.61±80.44nm. Solid lipid nanoparticles with well-defined morphology were tested in vitro for their possible application in drug delivery. Cell culture studies using C6 glioma cells on the nanoparticles showed enhanced growth and proliferation of cells without exhibiting any toxicity. In addition, normal cell morphology and improved uptake were observed by fluorescence microscopy images of rhodamine labeled modified solid lipid nanoparticles compared with unmodified nanoparticles. The cellular uptake study suggested that these nanoparticles could be a promising drug delivery system to enhance the uptake of antiviral drug by brain cells and it could be a suitable drug carrier system for the treatment of HIV. PMID:27207037

  3. E-cadherin expression on human carcinoma cell affects trastuzumab-mediated antibody-dependent cellular cytotoxicity through killer cell lectin-like receptor G1 on natural killer cells.

    PubMed

    Yamauchi, Chisako; Fujii, Satoshi; Kimura, Taichi; Kuwata, Takeshi; Wada, Noriaki; Mukai, Hirofumi; Matsumoto, Naoki; Fukayama, Masashi; Ochiai, Atsushi

    2011-05-01

    Trastuzumab is a recombinant antibody drug that is widely used for the treatment of HER2-overexpressing breast carcinoma. Despite encouraging clinical results, many HER2-overexpressing carcinomas are primarily resistant to trastuzumab. We attempted to explain trastuzumab resistance and search for solutions. Since the killer cell lectin-like receptor G1 (KLRG1), an inhibitory receptor expressed on subsets of natural killer (NK) cells recognizes E-cadherin as ligands and may inhibit immune responses by regulating the effector function of NK cells, we used HER2-overexpressing carcinoma cells which were expressing E-cadherin to investigate the role of antibody-dependent cellular cytotoxicity (ADCC) through KLRG1 on NK cells in vitro and vivo. The results indicated that HER2-overexpressing carcinoma cells were killed by trastuzumab-mediated ADCC and the ADCC activity was reflected the degree of E-cadherin expression on carcinoma cells. We found that expression of E-cadherin was shown to be a predictor of response to trastuzumab-based treatment for HER2-overexpressing carcinomas, furthermore, trastuzumab-mediated ADCC was markedly enhanced by KLRG1-negative peripheral blood mononuclear cells (PBMCs(KLRG1(-))). PMID:21387286

  4. Analysis of the role of antibody-dependent cellular cytotoxic antibody activity in murine neonatal herpes simplex virus infection with antibodies to synthetic peptides of glycoprotein D and monoclonal antibodies to glycoprotein B.

    PubMed Central

    Kohl, S; Strynadka, N C; Hodges, R S; Pereira, L

    1990-01-01

    The role of antibody in neonatal herpes simplex virus (HSV) infection remains controversial. A battery of well-characterized monoclonal antibodies to HSV glycoprotein B (gB), and polyclonal antibodies against synthetic peptides of predicted epitopes of HSV glycoprotein D (gD) were used to determine in vitro functional activity and association with protection against lethal infection in a murine model of neonatal HSV disease. Antiviral neutralization activity of HSV was not associated with antibody-dependent cellular cytotoxicity (ADCC) activity to HSV-infected cells in vitro. In a model of high dose challenge (10(4) PFU), protection was not afforded by any antibody alone, but was by antibody plus human mononuclear cells, and highly associated with ADCC functional activity (P less than 0.001). In a low dose challenge model, neutralizing activity of antibody alone was associated with protection in vivo (P less than 0.001). Of the nine neutralizing epitopes of gD in vitro, eight were predicted surface regions. Four of the five epitopic sites of gD (2-21, 267-276, 288-297, and 303-312) that were determined to be important targets of ADCC and in vivo protection were also predicted to be surface regions. The only exception was the antiserum to region 52-61 which was predicted to be buried and also showed these activities. ADCC as well as neutralizing antibody activity are important in protection against neonatal HSV infection. PMID:2164044

  5. Cytotoxicity of alkylating agents towards sensitive and resistant strains of Escherichia coli in relation to extent and mode of alkylation of cellular macromolecules and repair of alkylation lesions in deoxyribonucleic acids

    PubMed Central

    Lawley, P. D.; Brookes, P.

    1968-01-01

    1. A quantitative study was made of the relationship between survival of colony-forming ability in Escherichia coli strains B/r and Bs–1 and the extents of alkylation of cellular DNA, RNA and protein after treatment with mono- or di-functional sulphur mustards, methyl methanesulphonate or iodoacetamide. 2. The mustards and methyl methanesulphonate react with nucleic acids in the cells, in the same way as found previously from chemical studies in vitro, and with proteins. Iodoacetamide reacts only with protein, principally with the thiol groups of cysteine residues. 3. The extents of alkylation of cellular constituents required to prevent cell division vary widely according to the strain of bacteria and the nature of the alkylating agent. 4. The extents of alkylation of the sensitive and resistant strains at a given dose of alkylating agent do not differ significantly. 5. Removal of alkyl groups from DNA of cells of the resistant strains B/r and 15T− after alkylation with difunctional sulphur mustard was demonstrated; the product di(guanin-7-ylethyl) sulphide, characteristic of di- as opposed to mono-functional alkylation, was selectively removed; the time-scale of this effect suggests an enzymic rather than a chemical mechanism. 6. The sensitive strain Bs–1 removed alkyl groups from DNA in this way only at very low extents of alkylation. When sensitized to mustard action by treatment with iodoacetamide, acriflavine or caffeine, the extent of alkylation of cellular DNA corresponding to a mean lethal dose was decreased to approximately 3 molecules of di(guanin-7-ylethyl) sulphide in the genome of this strain. 7. Relatively large numbers of monofunctional alkylations per genome can be withstood by this sensitive strain. Iodoacetamide had the weakest cytotoxic action of the agents investigated; methyl methanesulphonate was significantly weaker in effect than the monofunctional sulphur mustard, which was in turn weaker than the difunctional sulphur mustard. 8

  6. Glycoengineered Monoclonal Antibodies with Homogeneous Glycan (M3, G0, G2, and A2) Using a Chemoenzymatic Approach Have Different Affinities for FcγRIIIa and Variable Antibody-Dependent Cellular Cytotoxicity Activities

    PubMed Central

    Kurogochi, Masaki; Mori, Masako; Osumi, Kenji; Tojino, Mami; Sugawara, Shu-ichi; Takashima, Shou; Hirose, Yuriko; Tsukimura, Wataru; Mizuno, Mamoru; Amano, Junko; Matsuda, Akio; Tomita, Masahiro; Takayanagi, Atsushi; Shoda, Shin-Ichiro; Shirai, Takashi

    2015-01-01

    Many therapeutic antibodies have been developed, and IgG antibodies have been extensively generated in various cell expression systems. IgG antibodies contain N-glycans at the constant region of the heavy chain (Fc domain), and their N-glycosylation patterns differ during various processes or among cell expression systems. The Fc N-glycan can modulate the effector functions of IgG antibodies, such as antibody-dependent cellular cytotoxicity (ADCC) and complement dependent cytotoxicity (CDC). To control Fc N-glycans, we performed a rearrangement of Fc N-glycans from a heterogeneous N-glycosylation pattern to homogeneous N-glycans using chemoenzymatic approaches with two types of endo-β-N-acetyl glucosaminidases (ENG’ases), one that works as a hydrolase to cleave all heterogeneous N-glycans, another that is used as a glycosynthase to generate homogeneous N-glycans. As starting materials, we used an anti-Her2 antibody produced in transgenic silkworm cocoon, which consists of non-fucosylated pauci-mannose type (Man2-3GlcNAc2), high-mannose type (Man4-9GlcNAc2), and complex type (Man3GlcNAc3-4) N-glycans. As a result of the cleavage of several ENG’ases (endoS, endoM, endoD, endoH, and endoLL), the heterogeneous glycans on antibodies were fully transformed into homogeneous-GlcNAc by a combination of endoS, endoD, and endoLL. Next, the desired N-glycans (M3; Man3GlcNAc1, G0; GlcNAc2Man3GlcNAc1, G2; Gal2GlcNAc2Man3GlcNAc1, A2; NeuAc2Gal2GlcNAc2Man3GlcNAc1) were transferred from the corresponding oxazolines to the GlcNAc residue on the intact anti-Her2 antibody with an ENG’ase mutant (endoS-D233Q), and the glycoengineered anti-Her2 antibody was obtained. The binding assay of anti-Her2 antibody with homogenous N-glycans with FcγRIIIa-V158 showed that the glycoform influenced the affinity for FcγRIIIa-V158. In addition, the ADCC assay for the glycoengineered anti-Her2 antibody (mAb-M3, mAb-G0, mAb-G2, and mAb-A2) was performed using SKBR-3 and BT-474 as target cells

  7. Protein Kinase CK2 Inhibition Down Modulates the NF-κB and STAT3 Survival Pathways, Enhances the Cellular Proteotoxic Stress and Synergistically Boosts the Cytotoxic Effect of Bortezomib on Multiple Myeloma and Mantle Cell Lymphoma Cells

    PubMed Central

    Manni, Sabrina; Brancalion, Alessandra; Mandato, Elisa; Tubi, Laura Quotti; Colpo, Anna; Pizzi, Marco; Cappellesso, Rocco; Zaffino, Fortunato; Di Maggio, Speranza Antonia; Cabrelle, Anna; Marino, Filippo; Zambello, Renato; Trentin, Livio; Adami, Fausto; Gurrieri, Carmela; Semenzato, Gianpietro; Piazza, Francesco

    2013-01-01

    CK2 is a pivotal pro-survival protein kinase in multiple myeloma that may likely impinge on bortezomib-regulated cellular pathways. In the present study, we investigated CK2 expression in multiple myeloma and mantle cell lymphoma, two bortezomib-responsive B cell tumors, as well as its involvement in bortezomib-induced cytotoxicity and signaling cascades potentially mediating bortezomib resistance. In both tumors, CK2 expression correlated with that of its activated targets NF-κB and STAT3 transcription factors. Bortezomib-induced proliferation arrest and apoptosis were significantly amplified by the simultaneous inhibition of CK2 with two inhibitors (CX-4945 and K27) in multiple myeloma and mantle cell lymphoma cell lines, in a model of multiple myeloma bone marrow microenvironment and in cells isolated from patients. CK2 inhibition empowered bortezomib-triggered mitochondrial-dependent cell death. Phosphorylation of NF-κB p65 on Ser529 (a CK2 target site) and rise of the levels of the endoplasmic reticulum stress kinase/endoribonuclease Ire1α were markedly reduced upon CK2 inhibition, as were STAT3 phospho Ser727 levels. On the contrary, CK2 inhibition increased phospho Ser51 eIF2α levels and enhanced the bortezomib-dependent accumulation of poly-ubiquitylated proteins and of the proteotoxic stress-associated chaperone Hsp70. Our data suggest that CK2 over expression in multiple myeloma and mantle cell lymphoma cells might sustain survival signaling cascades and can antagonize bortezomib-induced apoptosis at different levels. CK2 inhibitors could be useful in bortezomib-based combination therapies. PMID:24086494

  8. Cellular resilience.

    PubMed

    Smirnova, Lena; Harris, Georgina; Leist, Marcel; Hartung, Thomas

    2015-01-01

    Cellular resilience describes the ability of a cell to cope with environmental changes such as toxicant exposure. If cellular metabolism does not collapse directly after the hit or end in programmed cell death, the ensuing stress responses promote a new homeostasis under stress. The processes of reverting "back to normal" and reversal of apoptosis ("anastasis") have been studied little at the cellular level. Cell types show astonishingly similar vulnerability to most toxicants, except for those that require a very specific target, metabolism or mechanism present only in specific cell types. The majority of chemicals triggers "general cytotoxicity" in any cell at similar concentrations. We hypothesize that cells differ less in their vulnerability to a given toxicant than in their resilience (coping with the "hit"). In many cases, cells do not return to the naive state after a toxic insult. The phenomena of "pre-conditioning", "tolerance" and "hormesis" describe this for low-dose exposures to toxicants that render the cell more resistant to subsequent hits. The defense and resilience programs include epigenetic changes that leave a "memory/scar" - an alteration as a consequence of the stress the cell has experienced. These memories might have long-term consequences, both positive (resistance) and negative, that contribute to chronic and delayed manifestations of hazard and, ultimately, disease. This article calls for more systematic analyses of how cells cope with toxic perturbations in the long-term after stressor withdrawal. A technical prerequisite for these are stable (organotypic) cultures and a characterization of stress response molecular networks. PMID:26536287

  9. Manipulation of cellular GSH biosynthetic capacity via TAT-mediated protein transduction of wild-type or a dominant-negative mutant of glutamate cysteine ligase alters cell sensitivity to oxidant-induced cytotoxicity

    SciTech Connect

    Backos, Donald S.; Brocker, Chad N.; Franklin, Christopher C.

    2010-02-15

    The glutathione (GSH) antioxidant defense system plays a central role in protecting mammalian cells against oxidative injury. Glutamate cysteine ligase (GCL) is the rate-limiting enzyme in GSH biosynthesis and is a heterodimeric holoenzyme composed of catalytic (GCLC) and modifier (GCLM) subunits. As a means of assessing the cytoprotective effects of enhanced GSH biosynthetic capacity, we have developed a protein transduction approach whereby recombinant GCL protein can be rapidly and directly transferred into cells when coupled to the HIV TAT protein transduction domain. Bacterial expression vectors encoding TAT fusion proteins of both GCL subunits were generated and recombinant fusion proteins were synthesized and purified to near homogeneity. The TAT-GCL fusion proteins were capable of heterodimerization and formation of functional GCL holoenzyme in vitro. Exposure of Hepa-1c1c7 cells to the TAT-GCL fusion proteins resulted in the time- and dose-dependent transduction of both GCL subunits and increased cellular GCL activity and GSH levels. A heterodimerization-competent, enzymatically deficient GCLC-TAT mutant was also generated in an attempt to create a dominant-negative suppressor of GCL. Transduction of cells with a catalytically inactive GCLC(E103A)-TAT mutant decreased cellular GCL activity in a dose-dependent manner. TAT-mediated manipulation of cellular GCL activity was also functionally relevant as transduction with wild-type GCLC(WT)-TAT or mutant GCLC(E103A)-TAT conferred protection or enhanced sensitivity to H{sub 2}O{sub 2}-induced cell death, respectively. These findings demonstrate that TAT-mediated transduction of wild-type or dominant-inhibitory mutants of the GCL subunits is a viable means of manipulating cellular GCL activity to assess the effects of altered GSH biosynthetic capacity.

  10. Antiatherogenic and antitumoral properties of Opuntia cladodes: inhibition of low density lipoprotein oxidation by vascular cells, and protection against the cytotoxicity of lipid oxidation product 4-hydroxynonenal in a colorectal cancer cellular model.

    PubMed

    Keller, Julia; Camaré, Caroline; Bernis, Corinne; Astello-García, Marizel; de la Rosa, Ana-Paulina Barba; Rossignol, Michel; del Socorro Santos Díaz, María; Salvayre, Robert; Negre-Salvayre, Anne; Guéraud, Françoise

    2015-09-01

    Opuntia species have been used for thousands of years as a folk medicine in the treatment of diseases. However, the components and protective mechanisms are still unclear. We make the hypothesis that Opuntia species may protect the development of oxidative stress-associated diseases, such as atherosclerosis or colon cancer, via their antioxidant properties. We investigated the protective effect of Opuntia cladode powder against the oxidation of low-density lipoprotein (LDL) evoked by vascular endothelial cells, an important risk factor for atherosclerosis development, and the toxicity of 4-hydroxynonenal (a major lipid peroxidation product) on normal (Apc +/+) and preneoplastic (Apc min/+) immortalized epithelial colon cells. Various Opuntia species classified according to their degree of domestication, from the wildest (Opuntia streptacantha, Opuntia hyptiacantha, Opuntia megacantha), medium (Opuntia albicarpa), to the most domesticated (Opuntia ficus-indica) were tested. Cladode powders prepared from these Opuntia species significantly inhibited LDL oxidation induced by incubation with murine endothelial cells and the subsequent foam cell formation of RAW 264.7 murine macrophages and cytotoxicity on murine endothelial cells. Moreover, Opuntia cladode powder blocked the promotion of colon cancer development on an in vitro model of colonocytes. It may be noted that the phenolic acid and flavonoids content, the antioxidant capacity, and the protective effect were relatively similar in all the cladode powders from wild (O. streptacantha) and domesticated Opuntia. Altogether, these data confirm the therapeutic potential of Opuntia cladodes in diseases associated with oxidative stress. PMID:25840808

  11. Paclitaxel-Loaded TPGS-b-PCL Nanoparticles: In Vitro Cytotoxicity and Cellular Uptake in MCF-7 and MDA-MB-231 Cells versus mPEG-b-PCL Nanoparticles and Abraxane®.

    PubMed

    Bernabeu, Ezequiel; Gonzalez, Lorena; Legaspi, Maria J; Moretton, Marcela A; Chiappetta, Diego A

    2016-01-01

    Nanomedicines have become an attractive platform for the development of novel drug delivery systems in cancer chemotherapy. Polymeric nanoparticles (NPs) represent one of the best well-investigated nanosized carriers for delivery of antineoplastic compounds. The "Pegylation strategy" of drug delivery systems has been used in order to improve carrier biodistribution, however, some nanosized systems with PEG on their surface have exhibited poorly-cellular drug internalization. In this context, the purpose of the present study was to compare in vitro performance of two paclitaxel (PTX)-loaded NPs systems based on two biocompatible copolymers of alpha tocopheryl polyethylene glycol 1000 succinate-block-poly(ε-caprolactone) (TPGS-b-PCL) and methoxyPEG- block-poly(ε-caprolactone) (mPEG-b-PCL) in terms of citotoxicity and PTX cellular uptake. Fur- thermore, TPGS-b-PCL NPs were also copared with the commercially available PTX nano-sized formulation Abraxane®. Both TPGS-b-PCL and mPEG-b-PCL derivates were synthesized by ring opening polymerization of ε-caprolactone employing microwaved radiation. NPs were obtained by a solvent evaporation technique where the PTX content was determined by reverse-phase HPLC. The resulting NPs had an average size between 200 and 300 nm with a narrow size distribution. Also both NPs systems showed a spherical shape. The in vitro PTX release profile from the NPs was characterized employing the dialysis membrane method where all drug-loaded formulations showed a sustained and slow release of PTX. Finally, in vitro assays demonstrated that PTX-loaded TPGS- b-PCL exhibited a significant higher antitumor activity than PTX-loaded mPEG-b-PCL NPs and Abraxane® against an estrogen-dependent (MCF-7) and an estrogen independent (MDA-MB-231) breast cancer cells lines. Furthermore TPGS-b-PCL NPs showed a significant increase on PTX cellular uptake, for both breast cell lines, in comparison with mPEG-b-PCL NPs and Abraxane®. Overall findings confirmed

  12. Natural deep eutectic solvents: cytotoxic profile.

    PubMed

    Hayyan, Maan; Mbous, Yves Paul; Looi, Chung Yeng; Wong, Won Fen; Hayyan, Adeeb; Salleh, Zulhaziman; Mohd-Ali, Ozair

    2016-01-01

    The purpose of this study was to investigate the cytotoxic profiles of different ternary natural deep eutectic solvents (NADESs) containing water. For this purpose, five different NADESs were prepared using choline chloride as a salt, alongside five hydrogen bond donors (HBD) namely glucose, fructose, sucrose, glycerol, and malonic acid. Water was added as a tertiary component during the eutectics preparation, except for the malonic acid-based mixture. Coincidentally, the latter was found to be more toxic than any of the water-based NADESs. A trend was observed between the cellular requirements of cancer cells, the viscosity of the NADESs, and their cytotoxicity. This study also highlights the first time application of the conductor-like screening model for real solvent (COSMO-RS) software for the analysis of the cytotoxic mechanism of NADESs. COSMO-RS simulation of the interactions between NADESs and cellular membranes' phospholipids suggested that NADESs strongly interacted with cell surfaces and that their accumulation and aggregation possibly defined their cytotoxicity. This reinforced the idea that careful selection of NADESs components is necessary, as it becomes evident that organic acids as HBD highly contribute to the increasing toxicity of these neoteric mixtures. Nevertheless, NADESs in general seem to possess relatively less acute toxicity profiles than their DESs parents. This opens the door for future large scale utilization of these mixtures. PMID:27386357

  13. Toxicology and cellular effect of manufactured nanomaterials

    DOEpatents

    Chen, Fanqing

    2014-07-22

    The increasing use of nanotechnology in consumer products and medical applications underlies the importance of understanding its potential toxic effects to people and the environment. Herein are described methods and assays to predict and evaluate the cellular effects of nanomaterial exposure. Exposing cells to nanomaterials at cytotoxic doses induces cell cycle arrest and increases apoptosis/necrosis, activates genes involved in cellular transport, metabolism, cell cycle regulation, and stress response. Certain nanomaterials induce genes indicative of a strong immune and inflammatory response within skin fibroblasts. Furthermore, the described multiwall carbon nanoonions (MWCNOs) can be used as a therapeutic in the treatment of cancer due to its cytotoxicity.

  14. Cytotoxicity and intracellular dissolution of nickel nanowires.

    PubMed

    Perez, Jose E; Contreras, Maria F; Vilanova, Enrique; Felix, Laura P; Margineanu, Michael B; Luongo, Giovanni; Porter, Alexandra E; Dunlop, Iain E; Ravasi, Timothy; Kosel, Jürgen

    2016-09-01

    The assessment of cytotoxicity of nanostructures is a fundamental step for their development as biomedical tools. As widely used nanostructures, nickel nanowires (Ni NWs) seem promising candidates for such applications. In this work, Ni NWs were synthesized and then characterized using vibrating sample magnetometry, energy dispersive X-Ray analysis, and electron microscopy. After exposure to the NWs, cytotoxicity was evaluated in terms of cell viability, cell membrane damage, and induced apoptosis/necrosis on the model human cell line HCT 116. The influence of NW to cell ratio (10:1 to 1000:1) and exposure times up to 72 hours was analyzed for Ni NWs of 5.4 μm in length, as well as for Ni ions. The results show that cytotoxicity markedly increases past 24 hours of incubation. Cellular uptake of NWs takes place through the phagocytosis pathway, with a fraction of the dose of NWs dissolved inside the cells. Cell death results from a combination of apoptosis and necrosis, where the latter is the outcome of the secondary necrosis pathway. The cytotoxicity of Ni ions and Ni NWs dissolution studies suggest a synergistic toxicity between NW aspect ratio and dissolved Ni, with the cytotoxic effects markedly increasing after 24 hours of incubation. PMID:26692167

  15. Ethanol cytotoxic effect on trophoblast cells.

    PubMed

    Clave, S; Joya, X; Salat-Batlle, J; Garcia-Algar, O; Vall, O

    2014-03-01

    Prenatal ethanol exposure may cause both, altered fetal neurodevelopment and impaired placental function. These disturbances can lead to growth retardation, which is one of the most prevalent features in Fetal Alcohol Syndrome (FAS). It is not known whether there is a specific pattern of cytotoxicity caused by ethanol that can be extrapolated to other cell types. The aim of this study was to determine the cytotoxic effects caused by sustained exposure of trophoblast cells to ethanol. The cytotoxic effect of sustained exposure to standard doses of ethanol on an in vitro human trophoblast cell line, JEG3, was examined. Viable cell count by exclusion method, total protein concentration, lactate dehydrogenase (LDH) activity and activation of apoptotic markers (P-H2AX, caspase-3 and PARP-1) were determined. Sustained exposure to ethanol decreased viable cell count and total protein concentration. LDH activity did not increased in exposed cells but apoptotic markers were detected. In addition, there was a dose-dependent relationship between ethanol concentration and apoptotic pathways activation. Sustained ethanol exposure causes cellular cytotoxicity by apoptotic pathways induction as a result of DNA damage. This apoptotic induction may partially explain the altered function of placental cells and the damage previously detected in other tissues. PMID:24374569

  16. Evaluation of cytotoxicity of different tobacco product preparations.

    PubMed

    Arimilli, Subhashini; Damratoski, Brad E; Bombick, Betsy; Borgerding, Michael F; Prasad, G L

    2012-12-01

    Acute exposure to cigarette smoke or its components triggers diverse cellular effects, including cytotoxicity. However, available data regarding the potential cytotoxic effects of smokeless tobacco (ST) extracts lack consensus. Here, we investigated the relative biological effects of 2S3 reference ST, and whether ST elicits differential cellular/molecular responses compared to combustible tobacco product preparations (TPPs) prepared from 3R4F cigarettes. Total particulate matter (TPM) and whole smoke conditioned medium (WS-CM) were employed as combustible TPPs, while the ST extract was used as non-combustible TPP. HL60, THP1 cells and human PBMCs were used to examine the effects of TPPs in short-term cell culture. Corresponding EC(50) values, normalized for nicotine content of the TPPs, suggest that combustible TPPs induced higher cytotoxicity as follows: WS-CM TPM ≥ ≫ST extract>nicotine. While all three TPPs induced detectable levels of DNA damage and IL8 secretion, the combustible TPPs were significantly more potent than the ST preparation. The major PBMC subsets showed differential cytotoxicity to combustible TPPs as follows: CD4>CD8>monocytes>NK cells. These findings suggest that, relative cytotoxic and other cell biological effects of TPPs are dose-dependent, and that ST extract is the least cytotoxic TPP tested in this study. PMID:22996032

  17. EFFECTS OF SELECTED ASBESTOS FIBERS ON CELLULAR AND MOLECULAR PARAMETERS

    EPA Science Inventory

    Embryonic cultures were used to compare the effects of five asbestos materials on a cellular, biochemical and molecular basis. Chrysotile was found to be the most cytotoxic followed by crocidolite, tremolite, amosite, and silica. Results of tests involving cellular ratios of cycl...

  18. A study on the cytotoxicity of carbon-based materials.

    PubMed

    Saha, Dipendu; Heldt, Caryn L; Gencoglu, Maria F; Vijayaragavan, K Saagar; Chen, Jihua; Saksule, Ashish

    2016-11-01

    With an aim to understand the origin and key contributing factors towards carbon-induced cytotoxicity, we have studied five different carbon samples with diverse surface area, pore width, shape and size, conductivity and surface functionality. All the carbon materials were characterized with surface area and pore size distribution, X-ray photoelectron spectroscopy (XPS) and electron microscopic imaging. We performed cytotoxicity study in Caco-2 cells by colorimetric assay, oxidative stress analysis by reactive oxygen species (ROS) detection, cellular metabolic activity measurement by adenosine triphosphate (ATP) depletion and visualization of cellular internalization by TEM imaging. The carbon materials demonstrated a varying degree of cytotoxicity in contact with Caco-2 cells. The lowest cell survival rate was observed for nanographene, which possessed the minimal size amongst all the carbon samples under this study. None of the carbons induced oxidative stress to the cells as indicated by the ROS generation results. Cellular metabolic activity study revealed that the carbon materials caused ATP depletion in cells and nanographene caused the highest depletion. Visual observation by TEM imaging indicated the cellular internalization of nanographene. This study confirmed that the size is the key cause of carbon-induced cytotoxicity and it is probably caused by the ATP depletion within the cell. PMID:27524001

  19. Determination of Cytotoxicity.

    PubMed

    2016-01-01

    Cytotoxicity assays are used for drug screening and cytotoxicity tests of chemicals. Nowadays, various reagents are used for cell viability detection. They are based on various cell functions such as enzyme activity, cell membrane permeability, cell adherence, ATP production, co-enzyme production and nucleotide uptake activity. Many have established methods such as colony formation method, crystal violet method, tritium-labelled thymidine uptake method, MTT and WST methods, which are used for counting the number of live cells. Moreover, trypan blue is a widely used assay for staining dead cells. In this method, cell viability must be determined by counting the unstained cells with a microscope or other instruments. This chapter is a collection of all these methods to be followed by researchers in a sequential manner. PMID:26939283

  20. Cytotoxicity of Vinca minor.

    PubMed

    Khanavi, Mahnaz; Pourmoslemi, Shabnam; Farahanikia, Behnaz; Hadjiakhoondi, Abbas; Ostad, Seyed Nasser

    2010-01-01

    Vinca minor L. (Apocynaceae) is a medicinal plant that has long been used to treat cerebral and memory disorders in European folk medicine. Furthermore, it contains more than 50 alkaloids, some of them having bisindole structure such as the antineoplastic alkaloids present in Catharanthus roseus (L.) G. Don (Apocynaceae). In this study, the plant's alkaloid extract was divided into three fractions and the cytotoxic effects on cell proliferation of HT-29, Caco-2, T47D, and NIH/3T3 cell lines were examined. All alkaloid fractions showed a dose-dependent cytotoxic effect on the cell lines. IC(50) values confirmed that the growth and proliferation of NIH/3T3 cells were less affected in comparison to other cell lines. PMID:20645762

  1. Fluorinated Nanocarbons Cytotoxicity.

    PubMed

    Teo, Wei Zhe; Chua, Chun Kiang; Sofer, Zdenek; Pumera, Martin

    2015-09-01

    As the research in nanotechnology progresses, there will eventually be an influx in the number of commercial products containing different types of nanomaterials. This phenomenon might damage our health and environment if the nanomaterials used are found to be toxic and they are released into the waters when the products degrade. In this study, we investigated the cytotoxicity of fluorinated nanocarbons (CXFs), a group of nanomaterials which can find applications in solid lubricants and lithium primary batteries. Our cell viability findings indicated that the toxicological effects induced by the CXF are dependent on the dose, size, shape, and fluorine content of the CXF. In addition, we verified that CXFs have insignificant interactions with the cell viability assays-methylthiazolyldiphenyl-tetrazolium bromide (MTT) and water-soluble tetrazolium salt (WST-8), thus suggesting that the cytotoxicity data obtained are unlikely to be affected by CXF-induced artifacts and the results will be reliable. PMID:26215131

  2. Polychlorinated biphenyls (PCBs) depress allogeneic natural cytotoxicity by earthworm coelomocytes

    SciTech Connect

    Suzuki, M.M.; Cooper, E.L.; Eyambe, G.S.; Goven, A.J.; Fitzpatrick, L.C.; Venables, B.J. |

    1995-10-01

    Coelomocytes of the earthworm Lumbricus terrestris caused significant spontaneous allogeneic cytotoxicity in a 24-h trypan blue assay, but not in an assay using lactate dehydrogenase (LDH) release. Allogeneic cytotoxicity assays using cells from worms exposed to polychlorinated biphenyls (PCBs) suggest that PCBs can suppress a natural killing (NK-like) reaction. The implications of this work are twofold: understanding the evolution of natural killing (NK-like) activity and providing preliminary information on how spontaneous killing, a component of cellular immunity, may be compromised by pollutants.

  3. Autoxidation and cytotoxicity

    SciTech Connect

    Borg, D C; Schaich, K M; Elmore, Jr, J J

    1980-01-01

    A comprehensive synthesis, or reaction schema, to relate autoxidations of non-lipid compounds to lipid chain peroxidation in vivo is presented. This is done in the context of cytotoxic autoxidation reactions, and it is concluded that hydroxyl radicals produced by iron-dependent Fenton reactions serve as both primary toxicants and as sources of secondary toxicants. The latter stem from lipid chain peroxidation initiated by the Fenton-derived hydroxyl radicals, which are visualized as the obligate coupling step linking enzyme-dependent and non-enzymic autoxidations to potentially toxic outcomes.

  4. Variant antigenic peptide promotes cytotoxic T lymphocyte adhesion to target cells without cytotoxicity

    PubMed Central

    Shotton, David M.; Attaran, Amir

    1998-01-01

    Timelapse video microscopy has been used to record the motility and dynamic interactions between an H-2Db-restricted murine cytotoxic T lymphocyte clone (F5) and Db-transfected L929 mouse fibroblasts (LDb) presenting normal or variant antigenic peptides from human influenza nucleoprotein. F5 cells will kill LDb target cells presenting specific antigen (peptide NP68: ASNENMDAM) after “browsing” their surfaces for between 8 min and many hours. Cell death is characterized by abrupt cellular rounding followed by zeiosis (vigorous “boiling” of the cytoplasm and blebbing of the plasma membrane) for 10–20 min, with subsequent cessation of all activity. Departure of cytotoxic T lymphocytes from unkilled target cells is rare, whereas serial killing is sometimes observed. In the absence of antigenic peptide, cytotoxic T lymphocytes browse target cells for much shorter periods, and readily leave to encounter other targets, while never causing target cell death. Two variant antigenic peptides, differing in nonamer position 7 or 8, also act as antigens, albeit with lower efficiency. A third variant peptide NP34 (ASNENMETM), which differs from NP68 in both positions and yet still binds Db, does not stimulate F5 cytotoxicity. Nevertheless, timelapse video analysis shows that NP34 leads to a significant modification of cell behavior, by up-regulating F5–LDb adhesive interactions. These data extend recent studies showing that partial agonists may elicit a subset of the T cell responses associated with full antigen stimulation, by demonstrating that TCR interaction with variant peptide antigens can trigger target cell adhesion and surface exploration without activating the signaling pathway that results in cytotoxicity. PMID:9861010

  5. Cytotoxicity of denture adhesives.

    PubMed

    de Gomes, Pedro Sousa; Figueiral, Maria Helena; Fernandes, Maria Helena R; Scully, Crispian

    2011-12-01

    Ten commercially available denture adhesives, nine soluble formulations (six creams, three powders) and one insoluble product (pad), were analyzed regarding the cytotoxicity profile in direct and indirect assays using L929 fibroblast cells. In the direct assay, fibroblasts were seeded over the surface of a thick adhesive gel (5%, creams; 2.5%, powders and pad). In the indirect assay, cells were cultured in the presence of adhesive extracts prepared in static and dynamic conditions (0.5-2%, creams; 0.25-1%, powders and pad). Cell toxicity was assessed for cell viability/proliferation (MTT assay) and cell morphology (observation of the F-actin cytoskeleton organization by confocal laser scanning microscopy). Direct contact of the L929 fibroblasts with the thick adhesive gels caused no, or only a slight, decrease in cell viability/proliferation. The adhesive extracts (especially those prepared in dynamic conditions) caused significantly higher growth inhibition of fibroblasts and, in addition, caused dose- and time-dependent effects, throughout the 6-72 h exposure time. Also, dose-dependent effects on cell morphology, with evident disruption of the F-actin cytoskeleton organization, were seen in the presence of most adhesives. In conclusion, the adhesives possessed different degrees of cytotoxicity, but similar dose- and time-dependent biological profiles. PMID:20844908

  6. Enhancement of antibody-dependent cell mediated cytotoxicity: a new era in cancer treatment

    PubMed Central

    Rajasekaran, Narendiran; Chester, Cariad; Yonezawa, Atsushi; Zhao, Xing; Kohrt, Holbrook E

    2015-01-01

    The therapeutic efficacy of some anti-tumor monoclonal antibodies (mAbs) depends on the capacity of the mAb to recognize the tumor-associated antigen and induce cytotoxicity via a network of immune effector cells. This process of antibody-dependent cell-mediated cytotoxicity (ADCC) against tumor cells is triggered by the interaction of the fragment crystallizable (Fc) portion of the mAb with the Fc receptors on effector cells like natural killer cells, macrophages, γδ T cells, and dendritic cells. By augmenting ADCC, the antitumor activity of mAbs can be significantly increased. Currently, identifying and developing therapeutic agents that enhance ADCC is a growing area of research. Combining existing tumor-targeting mAbs and ADCC-promoting agents that stimulate effector cells will translate to greater clinical responses. In this review, we discuss strategies for enhancing ADCC and emphasize the potential of combination treatments that include US Food and Drug Administration-approved mAbs and immunostimulatory therapeutics.

  7. Gold Nanoparticles Cytotoxicity

    NASA Astrophysics Data System (ADS)

    Mironava, Tatsiana

    Over the last two decades gold nanoparticles (AuNPs) have been used for many scientific applications and have attracted attention due to the specific chemical, electronic and optical size dependent properties that make them very promising agents in many fields such as medicine, imagine techniques and electronics. More specifically, biocompatible gold nanoparticles have a huge potential for use as the contrast augmentation agent in X-ray Computed Tomography and Photo Acoustic Tomography for early tumor diagnostic as well these nanoparticles are extensively researched for enhancing the targeted cancer treatment effectiveness such as photo-thermal and radiotherapy. In most biomedical applications biocompatible gold nanoparticles are labeled with specific tumor or other pathology targeting antibodies and used for site specific drug delivery. However, even though gold nanoparticles poses very high level of anti cancer properties, the question of their cytotoxicity ones they are released in normal tissue has to be researched. Moreover, the huge amount of industrially produced gold nanoparticles raises the question of these particles being a health hazard, since the penetration is fairly easy for the "nano" size substances. This study focuses on the effect of AuNPs on a human skin tissue, since it is fall in both categories -- the side effects for biomedical applications and industrial workers and users' exposure during production and handling. Therefore, in the present project, gold nanoparticles stabilized with the biocompatible agent citric acid were generated and characterized by Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM). The cytotoxic effect of AuNPs release to healthy skin tissue was modeled on 3 different cell types: human keratinocytes, human dermal fibroblasts, and human adipose derived stromal (ADS) cells. The AuNPs localization inside the cell was found to be cell type dependent. Overall cytotoxicity was found to be dependent

  8. Cytotoxicity of halogenated graphenes

    NASA Astrophysics Data System (ADS)

    Teo, Wei Zhe; Khim Chng, Elaine Lay; Sofer, Zdeněk; Pumera, Martin

    2013-12-01

    Graphene and its family of derivatives possess unique and remarkable physicochemical properties which make them valuable materials for applications in many areas like electronics, energy storage and biomedicine. In response to the possibility of its large-scale manufacturing as commercial products in the future, an investigation was conducted to determine the cytotoxicity of one particular family of graphene derivatives, the halogenated graphenes, for the first time. Halogenated graphenes were prepared through thermal exfoliation of graphite oxide in gaseous chlorine, bromine or iodine atmospheres to yield chlorine- (TRGO-Cl), bromine- (TRGO-Br) and iodine-doped graphene (TRGO-I) respectively. 24 h exposure of human lung carcinoma epithelial cells (A549) to the three halogenated graphenes and subsequent cell viability assessments using methylthiazolyldiphenyl-tetrazolium bromide (MTT) and water-soluble tetrazolium salt (WST-8) assays revealed that all the halogenated graphenes examined are rather cytotoxic at the concentrations tested (3.125 μg mL-1 to 200 μg mL-1) and the effects are dose-dependent, with TRGO-Cl reducing the cell viability to as low as 25.7% at the maximum concentration of 200 μg mL-1. Their levels of cytotoxicity can be arranged in the order of TRGO-Cl > TRGO-Br > TRGO-I, and it is suggested that the amount of halogen present in the graphene material is the determining factor for the observed trend. Control experiments were carried out to test for possible nanomaterial-induced interference as a consequence of reaction between the halogenated graphenes and the viability markers (MTT/WST-8 reagent) or binding of the formazan products under cell-free conditions. The data obtained eliminate the probability of significant influence by these interferents as the change in the normalized percentage of formazan formed is relatively small and thorough washings were performed prior to the viability assessments to reduce the amount of halogenated

  9. Calcium modulation of doxorubicin cytotoxicity in yeast and human cells.

    PubMed

    Nguyen, Thi Thuy Trang; Lim, Ying Jun; Fan, Melanie Hui Min; Jackson, Rebecca A; Lim, Kim Kiat; Ang, Wee Han; Ban, Kenneth Hon Kim; Chen, Ee Sin

    2016-03-01

    Doxorubicin is a widely used chemotherapeutic agent, but its utility is limited by cellular resistance and off-target effects. To understand the molecular mechanisms regulating chemotherapeutic responses to doxorubicin, we previously carried out a genomewide search of doxorubicin-resistance genes in Schizosaccharomyces pombe fission yeast and showed that these genes are organized into networks that counteract doxorubicin cytotoxicity. Here, we describe the identification of a subgroup of doxorubicin-resistance genes that, when disrupted, leads to reduced tolerance to exogenous calcium. Unexpectedly, we observed a suppressive effect of calcium on doxorubicin cytotoxicity, where concurrent calcium and doxorubicin treatment resulted in significantly higher cell survival compared with cells treated with doxorubicin alone. Conversely, inhibitors of voltage-gated calcium channels enhanced doxorubicin cytotoxicity in the mutants. Consistent with these observations in fission yeast, calcium also suppressed doxorubicin cytotoxicity in human breast cancer cells. Further epistasis analyses in yeast showed that this suppression of doxorubicin toxicity by calcium was synergistically dependent on Rav1 and Vph2, two regulators of vacuolar-ATPase assembly; this suggests potential modulation of the calcium-doxorubicin interaction by fluctuating proton concentrations within the cellular environment. Thus, the modulatory effects of drugs or diet on calcium concentrations should be considered in doxorubicin treatment regimes. PMID:26891792

  10. Nanomaterial cytotoxicity is composition, size, and cell type dependent

    PubMed Central

    2010-01-01

    Background Despite intensive research efforts, reports of cellular responses to nanomaterials are often inconsistent and even contradictory. Additionally, relationships between the responding cell type and nanomaterial properties are not well understood. Using three model cell lines representing different physiological compartments and nanomaterials of different compositions and sizes, we have systematically investigated the influence of nanomaterial properties on the degrees and pathways of cytotoxicity. In this study, we selected nanomaterials of different compositions (TiO2 and SiO2 nanoparticles, and multi-wall carbon nanotubes [MWCNTs]) with differing size (MWCNTs of different diameters < 8 nm, 20-30 nm, > 50 nm; but same length 0.5-2 μm) to analyze the effects of composition and size on toxicity to 3T3 fibroblasts, RAW 264.7 macrophages, and telomerase-immortalized (hT) bronchiolar epithelial cells. Results Following characterization of nanomaterial properties in PBS and serum containing solutions, cells were exposed to nanomaterials of differing compositions and sizes, with cytotoxicity monitored through reduction in mitochondrial activity. In addition to cytotoxicity, the cellular response to nanomaterials was characterized by quantifying generation of reactive oxygen species, lysosomal membrane destabilization and mitochondrial permeability. The effect of these responses on cellular fate - apoptosis or necrosis - was then analyzed. Nanomaterial toxicity was variable based on exposed cell type and dependent on nanomaterial composition and size. In addition, nanomaterial exposure led to cell type dependent intracellular responses resulting in unique breakdown of cellular functions for each nanomaterial: cell combination. Conclusions Nanomaterials induce cell specific responses resulting in variable toxicity and subsequent cell fate based on the type of exposed cell. Our results indicate that the composition and size of nanomaterials as well as the target

  11. Fibril Fragmentation Enhances Amyloid Cytotoxicity*♦

    PubMed Central

    Xue, Wei-Feng; Hellewell, Andrew L.; Gosal, Walraj S.; Homans, Steve W.; Hewitt, Eric W.; Radford, Sheena E.

    2009-01-01

    Fibrils associated with amyloid disease are molecular assemblies of key biological importance, yet how cells respond to the presence of amyloid remains unclear. Cellular responses may not only depend on the chemical composition or molecular properties of the amyloid fibrils, but their physical attributes such as length, width, or surface area may also play important roles. Here, we report a systematic investigation of the effect of fragmentation on the structural and biological properties of amyloid fibrils. In addition to the expected relationship between fragmentation and the ability to seed, we show a striking finding that fibril length correlates with the ability to disrupt membranes and to reduce cell viability. Thus, despite otherwise unchanged molecular architecture, shorter fibrillar samples show enhanced cytotoxic potential than their longer counterparts. The results highlight the importance of fibril length in amyloid disease, with fragmentation not only providing a mechanism by which fibril load can be rapidly increased but also creating fibrillar species of different dimensions that can endow new or enhanced biological properties such as amyloid cytotoxicity. PMID:19808677

  12. Characterization of the Fluorescence Properties of 4-Dialkylaminochalcones and Investigation of the Cytotoxic Mechanism of Chalcones.

    PubMed

    Zhou, Bo; Jiang, Peixin; Lu, Junxuan; Xing, Chengguo

    2016-07-01

    Understanding the mechanisms responsible for the various biological activities of chalcones, particularly the direct cellular targets, presents an unmet challenge. Here, we prepared a series of fluorescent chalcone derivatives as chemical probes for their mechanistic investigation. Upon systematic physicochemical characterization, we explored their potential to elucidate the mode of action of chalcones' cytotoxicity. The fluorescence of the chalcones was found to be highly sensitive to structural and environmental factors. Structurally, a 4-dialkylamino group on the B ring, suitable electronic properties of the A ring substituents, and the planar conformation of the chalcone's core structure were essential for optimal fluorescence. Environmental factors influencing fluorescence included solvent polarity, pH, and the interactions of the chalcones with proteins and detergents. It was found that 18 chalcones showed a fluorescent brightness greater than 6000 M(-1)  cm(-1) in DMSO. However, water dramatically quenched the fluorescence, although it could be partially recovered in the presence of BSA or detergents. As expected, these fluorescent chalcones showed a sharp structure-activity relationship in their cellular cytotoxicity, leading to the identification of structurally similar cytotoxic and non-cytotoxic fluorescent chalcones as chemical probes. Confocal microscopy results revealed the co-localization of the cytotoxic probe C8 and tubulin in cells, supporting tubulin as the direct cellular target responsible for the cytotoxicity of chalcones. PMID:27214789

  13. EFFECTS OF SELECTED WATERBORNE PARTICULATES ON CELLULAR AND MOLECULAR PARAMETERS

    EPA Science Inventory

    Embryonic cultures were used to compare the effects of six particulate samples, some filtered directly from drinking water on a cellular, biochemical and molecular basis. Cytotoxicity was exhibited in human cells for all agents tested at the highest concentration used (10 mg/ml)....

  14. Cellular membrane collapse by atmospheric-pressure plasma jet

    SciTech Connect

    Kim, Kangil; Sik Yang, Sang E-mail: ssyang@ajou.ac.kr; Jun Ahn, Hak; Lee, Jong-Soo E-mail: ssyang@ajou.ac.kr; Lee, Jae-Hyeok; Kim, Jae-Ho

    2014-01-06

    Cellular membrane dysfunction caused by air plasma in cancer cells has been studied to exploit atmospheric-pressure plasma jets for cancer therapy. Here, we report that plasma jet treatment of cervical cancer HeLa cells increased electrical conductivity across the cellular lipid membrane and caused simultaneous lipid oxidation and cellular membrane collapse. We made this finding by employing a self-manufactured microelectrode chip. Furthermore, increased roughness of the cellular lipid membrane and sequential collapse of the membrane were observed by atomic force microscopy following plasma jet treatment. These results suggest that the cellular membrane catastrophe occurs via coincident altered electrical conductivity, lipid oxidation, and membrane roughening caused by an atmospheric-pressure plasma jet, possibly resulting in cellular vulnerability to reactive species generated from the plasma as well as cytotoxicity to cancer cells.

  15. Cytotoxicity of Hymenocallis expansa alkaloids.

    PubMed

    Antoun, M D; Mendoza, N T; Ríos, Y R; Proctor, G R; Wickramaratne, D B; Pezzuto, J M; Kinghorn, A D

    1993-08-01

    From the bulbs and leaves of Hymenocallis expansa (Amaryllidaceae), three alkaloid constituents were identified: (+)-tazettine, (+)-hippeastrine, and (-)-haemanthidine. These alkaloids demonstrated significant cytotoxicity when tested against a panel of human and murine tumor cell lines. PMID:8229020

  16. CELLULAR PATHOGENESIS OF DIABETIC GASTROENTEROPATHY

    PubMed Central

    Ördög, Tamás; Hayashi, Yujiro; Gibbons, Simon J.

    2010-01-01

    SUMMARY Gastroenteropathy manifesting in upper gastrointestinal symptoms, delayed gastric emptying, constipation, diarrhea and fecal incontinence occurs frequently in patients with diabetes mellitus and represents a significant health care burden. Current treatments are largely symptomatic and ineffective. Better understanding of the cellular and molecular pathogenesis of these disorders is required for the development of more effective therapies. Recent advances in our understanding of the inherent, high-level complexities of the control systems that execute and regulate gastrointestinal motility, together with the utilization of new experimental models and sophisticated physiological, morphological and molecular techniques have lead to the realization that diabetic gastroenteropathies cannot be ascribed to any singular defect or dysfunction. In fact, these disorders are multifactorial and involve a spectrum of metabolic and dystrophic changes that can potentially affect all key components of motor control including the systemic autonomic and enteric nervous systems, interstitial cells of Cajal and smooth muscle cells. Candidate pathomechanisms are also varied and include imbalance between pro- and anti-oxidative factors, altered trophic stimuli to mature cells and their progenitors, and, possibly, autoimmune factors. The goal of this paper is to review the cellular changes underlying diabetic gastroenteropathies and their potential causes, with particular focus on functional interactions between various cell types. It is proposed that diabetic gastroenteropathies should be considered a form of gastrointestinal neuromuscular dystrophy rather than a “functional” disorder. Future research should identify ways to block cytotoxic factors, support the regeneration of damaged cells and translate the experimental findings into new treatment modalities. PMID:19829287

  17. Cytotoxic activity of Staphylococcus hyicus.

    PubMed

    Allaker, R P; Whitlock, M; Lloyd, D H

    1991-01-01

    Culture supernatants from a number of Staphylococcus hyicus strains caused toxic effects to both murine fibroblast and porcine keratinocyte cells in culture. The extent of cytotoxicity was shown to differ between strains and may provide an indication of strain virulence. Purification of cytotoxic activity produced by S. hyicus (strain P119) using preparative isoelectric-focussing demonstrated it to be cytolytic, haemolytic and non-proteolytic. The cytotoxin demonstrates certain properties in common with the delta haemolysin of Staphylococcus aureus. PMID:2024438

  18. Calcium signaling and cytotoxicity.

    PubMed Central

    Kass, G E; Orrenius, S

    1999-01-01

    The divalent calcium cation Ca(2+) is used as a major signaling molecule during cell signal transduction to regulate energy output, cellular metabolism, and phenotype. The basis to the signaling role of Ca(2+) is an intricate network of cellular channels and transporters that allow a low resting concentration of Ca(2+) in the cytosol of the cell ([Ca(2+)]i) but that are also coupled to major dynamic and rapidly exchanging stores. This enables extracellular signals from hormones and growth factors to be transduced as [Ca(2+)]i spikes that are amplitude and frequency encoded. There is considerable evidence that a number of toxic environmental chemicals target these Ca(2+) signaling processes, alter them, and induce cell death by apoptosis. Two major pathways for apoptosis will be considered. The first one involves Ca(2+)-mediated expression of ligands that bind to and activate death receptors such as CD95 (Fas, APO-1). In the second pathway, Ca(2+) has a direct toxic effect and its primary targets include the mitochondria and the endoplasmic reticulum (ER). Mitochondria may respond to an apoptotic Ca(2+) signal by the selective release of cytochrome c or through enhanced production of reactive oxygen species and opening of an inner mitochondrial membrane pore. Toxic agents such as the environmental pollutant tributyltin or the natural plant product thapsigargin, which deplete the ER Ca(2+) stores, will induce as a direct result of this effect the opening of plasma membrane Ca(2+) channels and an ER stress response. In contrast, under some conditions, Ca(2+) signals may be cytoprotective and antagonize the apoptotic machinery. Images Figure 1 Figure 2 Figure 3 PMID:10229704

  19. Cellular Stress Responses and Monitored Cellular Activities.

    PubMed

    Sawa, Teiji; Naito, Yoshifumi; Kato, Hideya; Amaya, Fumimasa

    2016-08-01

    To survive, organisms require mechanisms that enable them to sense changes in the outside environment, introduce necessary responses, and resist unfavorable distortion. Consequently, through evolutionary adaptation, cells have become equipped with the apparatus required to monitor their fundamental intracellular processes and the mechanisms needed to try to offset malfunction without receiving any direct signals from the outside environment. It has been shown recently that eukaryotic cells are equipped with a special mechanism that monitors their fundamental cellular functions and that some pathogenic proteobacteria can override this monitoring mechanism to cause harm. The monitored cellular activities involved in the stressed intracellular response have been researched extensively in Caenorhabditis elegans, where discovery of an association between key mitochondrial activities and innate immune responses was named "cellular associated detoxification and defenses (cSADD)." This cellular surveillance pathway (cSADD) oversees core cellular activities such as mitochondrial respiration and protein transport into mitochondria, detects xenobiotics and invading pathogens, and activates the endocrine pathways controlling behavior, detoxification, and immunity. The cSADD pathway is probably associated with cellular responses to stress in human inflammatory diseases. In the critical care field, the pathogenesis of lethal inflammatory syndromes (e.g., respiratory distress syndromes and sepsis) involves the disturbance of mitochondrial respiration leading to cell death. Up-to-date knowledge about monitored cellular activities and cSADD, especially focusing on mitochondrial involvement, can probably help fill a knowledge gap regarding the pathogenesis of lethal inflammatory syndromes in the critical care field. PMID:26954943

  20. Cellular Phone Towers

    MedlinePlus

    ... the call. How are people exposed to the energy from cellular phone towers? As people use cell ... where people can be exposed to them. The energy from a cellular phone tower antenna, like that ...

  1. Evaluation of nanoencapsulated verteporfin's cytotoxicity using a microfluidic system.

    PubMed

    Tokarska, Katarzyna; Bułka, Magdalena; Bazylińska, Urszula; Jastrzębska, Elżbieta; Chudy, Michał; Dybko, Artur; Wilk, Kazimiera A; Brzózka, Zbigniew

    2016-08-01

    A new-generation of nanoencapsulated photosensitizers could be a good solution to perform effective photodynamic therapy (PDT). In this paper, we present physicochemical characterization and cellular investigation of newly prepared long-sustained release oil-core polyelectrolyte nanocarriers loaded with verteporfin (nano VP) in relation to free VP. For this purpose, a macroscale multiwell plates and multifunctional microfluidic system (for three types of cell cultures: monoculture, coculture and mixed culture) were used. A physical analysis of nano VP showed its high stability, monodispersity with unimodal shape and highly positive charge, what made them good candidates for cancer treatment. Biological properties (cellular internalization and uptake as well as cytotoxicity) of nano and free VP were evaluated using both carcinoma (A549) and normal (MRC-5) human lung cells. It was investigated that verteporfin was accumulated in cancer cells preferentially. Low cytotoxicity of the tested photosensitizer was observed in both macro, and microscale. However, in experiments performed in the microsystem, nano VP allowed the reduction of cytotoxic effect, especially in relation to the normal cells. It could result from the specific environment of cell growth in the microsystem which can quite closely mimic the in vivo conditions. Our results suggest that the presented microsystem could be a very useful microtool for testing of new generation of photosensitizers in various configurations of cell cultures, which are difficult to perform in the macroscale. Moreover, the prepared nano VP could be successfully used for further research i.e. evaluation of PDT procedures. PMID:26997162

  2. CYP3A5 mediates bioactivation and cytotoxicity of tetrandrine.

    PubMed

    Tian, Ye; Shen, Shuijie; Jiang, Yan; Shen, Qi; Zeng, Su; Zheng, Jiang

    2016-07-01

    Tetrandrine is a diaryl ether-type bisbenzylisoquinoline alkaloid and has shown multiple pharmacological activities. Our early work demonstrated that tetrandrine produced acute pulmonary toxicity and that tetrandrine was biotransformed to a quinone methide-derived metabolite mediated by CYP3A enzymes. The formation of the reactive intermediate is suggested to be responsible for the pulmonary toxicity induced by tetrandrine. In the present study, a WI-38-based Cyp3a5 transgenic cell line (WI-38/Cyp3a5) was established to investigate the role of CYP3A5 in tetrandrine-induced cytotoxicity. The transgenic cells were found to be more susceptible to the cytotoxicity of tetrandrine than the wild-type cells (WI-38/Vector). WI-38/Cyp3a5 cells showed higher cellular ROS levels, higher LDH activities in culture media, but lower cellular GSH contents than those observed in WI-38/Vector cells after exposure to tetrandrine. And severer apoptosis were observed in WI-38/Cyp3a5 cells after treatment with tetrandrine: WI-38/Cyp3a5 cells had higher proportion of early and late apoptotic cells, higher expression levels of caspase-3, but lower level of Bcl-2 than WI-38/Vector cells. This study provided strong evidence that CYP3A5 participated in tetrandrine-induced cytotoxicity. PMID:26302866

  3. Cytotoxicity and immunotoxicity of cyclopiazonic acid on human cells.

    PubMed

    Hymery, Nolwenn; Masson, Floriane; Barbier, Georges; Coton, Emmanuel

    2014-08-01

    In this study, in vitro cytotoxicity and immunotoxicity of the mycotoxin cyclopiazonic acid (CPA) was evaluated on human cells. To evaluate cytoxicity, several cellular targets were used (CD34+, monocytes, THP-1 and Caco-2). Monocytes were more sensitive to CPA than the THP-1 monocytic cell line after 48h of incubation in the tested conditions. Half maximal inhibitory concentration (IC50) were determined to be 8.5 × 10(-8) and 1.75 × 10(-7)M for monocytes and THP1, respectively, while IC50>1.25 × 10(-7)M was observed for Caco-2 and CD34+ cells. The CPA effect on macrophage differentiation was also examined at non-cytotoxic concentrations. The monocyte differentiation process was markedly disturbed in the presence of CPA. After 6 days of culture, CD71 expression was downregulated, while CD14 and CD11a expressions did not change. Moreover, activated macrophages showed a raised burst activity and TNF-α secretion. Overall, the results indicated that CPA exhibited toxicity on various human cellular models. Moreover, at non-cytotoxic concentrations, CPA disturbed human monocytes differentiation into macrophages. This work contributes to understanding the immunosuppressive properties of this food-related toxin. PMID:24747294

  4. Hierarchical cellular materials

    SciTech Connect

    Gibson, L.J.

    1991-01-01

    In this paper a method for estimating the contributions of both the composite and the cellular microstructures to the overall material properties and the mechanical efficiency of natural cellular solids will be described. The method will be demonstrated by focusing on the Young's modulus; similar techniques can be used for other material properties. The results suggest efficient microstructures for engineered cellular materials.

  5. Hierarchical cellular materials

    SciTech Connect

    Gibson, L.J.

    1991-12-31

    In this paper a method for estimating the contributions of both the composite and the cellular microstructures to the overall material properties and the mechanical efficiency of natural cellular solids will be described. The method will be demonstrated by focusing on the Young`s modulus; similar techniques can be used for other material properties. The results suggest efficient microstructures for engineered cellular materials.

  6. Cytotoxicity and Pharmacogenomics of Medicinal Plants from Traditional Korean Medicine

    PubMed Central

    Kuete, Victor; Seo, Ean-Jeong; Krusche, Benjamin; Oswald, Mira; Schröder, Sven; Greten, Henry Johannes; Lee, Ik-Soo; Efferth, Thomas

    2013-01-01

    Aim. The present study was designed to investigate the cytotoxicity of a panel of 280 Korean medicinal plants belonging to 73 families and 198 species against human CCRF-CEM leukemia cells. Selected phytochemicals were investigated in more detail for their mode of action. Methods. The resazurin assay was used to determine cytotoxicity of the plant extracts. Microarray-based mRNA expression profiling, COMPARE, and hierarchical cluster analyses were applied to identify which genes correlate with sensitivity or resistance to selected phytochemicals of the Korean plants. Results. The results of the resazurin assay showed that cytotoxicity extracts tested at 10 μg/mL from 13 samples inhibited proliferation more than 50% (IC50 < 10 μg/mL) and the most active plants are Sedum middendorffianum (15.33%) and Lycoris radiata (17.61%). Out of 13 selected phytochemicals from these plants, hopeaphenol and deoxynarciclasine were the most cytotoxic ones. Genes from various functional groups (transcriptional or translational regulation, signal transduction, cellular proliferation, intracellular trafficking, RNA metabolism, endoplasmic/sarcoplasmic reticulum function, etc.) were significantly correlated with response of tumor cell lines to these two compounds. Conclusion. The results provide evidence on the possible use of selected Korean medicinal plants and chemical constituents derived from them for the treatment of tumors. PMID:23935662

  7. Helicobacter pylori antigens as potential modulators of lymphocytes' cytotoxic activity.

    PubMed

    Rudnicka, Karolina; Włodarczyk, Marcin; Moran, Anthony P; Rechciński, Tomasz; Miszczyk, Eliza; Matusiak, Agnieszka; Szczęsna, Ewelina; Walencka, Maria; Rudnicka, Wiesława; Chmiela, Magdalena

    2012-01-01

    Helicobacter pylori (H.p) colonizes human gastric mucosa and causes gastric and duodenal ulcer disease or gastric cancer. Various H.p compounds may modulate the host immune response in regards to tolerance of the infection or disease development. The aim of this study was to determine whether H.p lipopolysaccharide (LPS) and glycine acid extract antigens (GE) or E. coli LPS influence the cytotoxic activity of peripheral blood lymphocytes from H.p infected - H.p (+) or uninfected - H.p (-) individuals, in the presence or absence of exogenous interleukin (IL)12. Individual H.p status was defined by the urea breath test. Lymphocytes, stimulated or not with H.p, and control antigens, with or without IL-12, were used as effector cells and epithelial HeLa cells as targets. The cytotoxicity of lymphocytes was expressed as the percentage of dead target cells unable to reduce tetrazolium salt. The supernatants from HeLa/lymphocyte cultures were used for detection of the cellular cytotoxicity markers granzyme B and caspase 8. The natural cytotoxic activity of lymphocytes from H.p (+) was less than that of H.p (-) donors. This may have been due to fewer natural killer cells of CD3(-) CD56(+) Nkp46(+) phenotype in H.p (+) in comparison to H.p (-) subjects. H.p GE and standard E. coli LPS enhanced the cytotoxicity of lymphocytes towards target cells whereas H.p LPS downregulated this activity. The decrease in lymphocyte cytotoxicity in response to H.p LPS correlated with a lack of IL-2 and IL-12 production, inhibition of interferon-γ production, and low IL-10 secretion by mononuclear leukocytes. IL-12 significantly enhanced the natural as well as H.p LPS and H.p GE driven cytotoxic capacity of lymphocytes. In conclusion, H.p LPS may negatively modulate natural cytotoxic activity and cytokine secretion by immunocompetent cells and thus be involved in the maintenance of infection and development of gastric pathologies. PMID:22040089

  8. Mechanistic Study on the Reduction of SWCNT-induced Cytotoxicity by Albumin Coating

    PubMed Central

    Liu, Yang; Ren, Lei; Yan, Dong

    2014-01-01

    Single walled carbon nanotubes (SWCNTs) are utilized in many areas, accompanied with the ever rising safety concerns. Coating the SWCNTs by serum albumin has shown promises in reduction of their cytotoxicity. The cause of toxicity reduction could be due to the blockage of cellular protein adsorption by bovine serum albumin (BSA). Here, our study explored the mechanism of toxicity reduction from the point of view of protein adsorption. Different loadings of BSA led to varied surface coverage of the SWCNTs, which was positively related to the level of cytotoxicity. In addition, the BSA-coated SWCNTs were tested for their surface morphology change, cellular uptake, and adsorption of cellular proteins. BSA could be competed off the SWCNT surface by the cytosol proteins, and thus a higher BSA loading was needed to provide better protection to the cells. Cellular uptake was also reduced with a higher BSA loading. Moreover, the BSA coating changed the surface property of SWCNTs, and as a consequence, altered the types of proteins adsorbed by the SWCNTs. Our results support that adsorption of BSA reduces cellular uptake of SWCNTs as well as adsorption of cellular proteins on SWCNTs, both contributing to the much lower cytotoxicity observed for the BSA-coated SWCNTs. PMID:25580058

  9. Proteomic approach to study the cytotoxicity of dioscin (saponin).

    PubMed

    Wang, Ying; Cheung, Yim Hing; Yang, Zhiqi; Chiu, Jen-Fu; Che, Chi-Ming; He, Qing-Yu

    2006-04-01

    Dioscin, extracted from the root of Polygonatum zanlanscianense pamp, exhibits cytotoxicity towards human myeloblast leukemia HL-60 cells. Proteomic analysis revealed that the expression of mitochondrial associated proteins was substantially altered in HL-60 cells corresponding to the dioscin treatment, suggesting that mitochondria are the major cellular target of dioscin. Mitochondrial functional studies validated that mitochondrial apoptotic pathway was initiated by dioscin treatment. Changes in proteome other than mitochondrial related proteins implicate that other mechanisms were also involved in dioscin-induced apoptosis in HL-60 cells, including the activity impairment in protein synthesis, alterations of phosphatases in cell signaling, and deregulation of oxidative stress and cell proliferation. Current study of protein alterations in dioscin-treated HL-60 cells suggested that dioscin exerts cytotoxicity through multiple apoptosis-inducing pathways. PMID:16548062

  10. Deoxynivalenol induces cytotoxicity and genotoxicity in animal primary cell culture.

    PubMed

    Singh, Shweta; Banerjee, Subham; Chattopadhyay, Pronobesh; Borthakur, Sashin Kumar; Veer, Vijay

    2015-03-01

    Deoxynivalenol (DON), a mycotoxin produced by Fusarium graminearum, is widely found as a contaminant of food. DON is responsible for a wide range of toxic activities, including gastro-intestinal, lymphoid, bone-marrow and cardiotoxicity. But, the complete explorations of toxicity in terms of hepatotoxicity, nephrotoxicity, cytotoxicity and genotoxicity as well have not been documented well. Again, the mechanisms through which DON damages the DNA and promotes cellular toxicity are not well established. Considering the above fact, this research article is focused on the effects of DON-induced toxicities on experimental animal model as well as its effects on cellular level via various toxicological investigations. DON treatment showed cytotoxicity and DNA damage. Further, flow cytometric analysis of hepatocytes showed cellular apoptosis, suggesting that DON-induced hepatotoxicity is, may be partly, mediated by apoptosis. Moreover, significant differences were found in each haematology and clinical chemistry value, either (p > 0.05). No abnormality of any organ was found during histopathological examination. Hence, it can be concluded that DON induces oxidative DNA damage and increases the formation of centromere positive micronuclei due to aneugenic activity. PMID:25578892

  11. Differential cytotoxicity of copper ferrite nanoparticles in different human cells.

    PubMed

    Ahmad, Javed; Alhadlaq, Hisham A; Alshamsan, Aws; Siddiqui, Maqsood A; Saquib, Quaiser; Khan, Shams T; Wahab, Rizwan; Al-Khedhairy, Abdulaziz A; Musarrat, Javed; Akhtar, Mohd Javed; Ahamed, Maqusood

    2016-10-01

    Copper ferrite nanoparticles (NPs) have the potential to be applied in biomedical fields such as cell labeling and hyperthermia. However, there is a lack of information concerning the toxicity of copper ferrite NPs. We explored the cytotoxic potential of copper ferrite NPs in human lung (A549) and liver (HepG2) cells. Copper ferrite NPs were crystalline and almost spherically shaped with an average diameter of 35 nm. Copper ferrite NPs induced dose-dependent cytotoxicity in both types of cells, evident by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide and neutral red uptake assays. However, we observed a quite different susceptibility in the two kinds of cells regarding toxicity of copper ferrite NPs. Particularly, A549 cells showed higher susceptibility against copper ferrite NP exposure than those of HepG2 cells. Loss of mitochondrial membrane potential due to copper ferrite NP exposure was observed. The mRNA level as well as activity of caspase-3 enzyme was higher in cells exposed to copper ferrite NPs. Cellular redox status was disturbed as indicated by induction of reactive oxygen species (oxidant) generation and depletion of the glutathione (antioxidant) level. Moreover, cytotoxicity induced by copper ferrite NPs was efficiently prevented by N-acetylcysteine treatment, which suggests that reactive oxygen species generation might be one of the possible mechanisms of cytotoxicity caused by copper ferrite NPs. To the best of our knowledge, this is the first report showing the cytotoxic potential of copper ferrite NPs in human cells. This study warrants further investigation to explore the mechanisms of differential toxicity of copper ferrite NPs in different types of cells. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26918645

  12. Reducing ZnO nanoparticle cytotoxicity by surface modification

    NASA Astrophysics Data System (ADS)

    Luo, Mingdeng; Shen, Cenchao; Feltis, Bryce N.; Martin, Lisandra L.; Hughes, Anthony E.; Wright, Paul F. A.; Turney, Terence W.

    2014-05-01

    Nanoparticulate zinc oxide (ZnO) is one of the most widely used engineered nanomaterials and its toxicology has gained considerable recent attention. A key aspect for controlling biological interactions at the nanoscale is understanding the relevant nanoparticle surface chemistry. In this study, we have determined the disposition of ZnO nanoparticles within human immune cells by measurement of total Zn, as well as the proportions of extra- and intracellular dissolved Zn as a function of dose and surface coating. From this mass balance, the intracellular soluble Zn levels showed little difference in regard to dose above a certain minimal level or to different surface coatings. PEGylation of ZnO NPs reduced their cytotoxicity as a result of decreased cellular uptake arising from a minimal protein corona. We conclude that the key role of the surface properties of ZnO NPs in controlling cytotoxicity is to regulate cellular nanoparticle uptake rather than altering either intracellular or extracellular Zn dissolution.Nanoparticulate zinc oxide (ZnO) is one of the most widely used engineered nanomaterials and its toxicology has gained considerable recent attention. A key aspect for controlling biological interactions at the nanoscale is understanding the relevant nanoparticle surface chemistry. In this study, we have determined the disposition of ZnO nanoparticles within human immune cells by measurement of total Zn, as well as the proportions of extra- and intracellular dissolved Zn as a function of dose and surface coating. From this mass balance, the intracellular soluble Zn levels showed little difference in regard to dose above a certain minimal level or to different surface coatings. PEGylation of ZnO NPs reduced their cytotoxicity as a result of decreased cellular uptake arising from a minimal protein corona. We conclude that the key role of the surface properties of ZnO NPs in controlling cytotoxicity is to regulate cellular nanoparticle uptake rather than

  13. Saponins as cytotoxic agents: a review

    PubMed Central

    Galanty, Agnieszka; Sobolewska, Danuta

    2010-01-01

    Saponins are natural glycosides which possess a wide range of pharmacological properties including cytotoxic activity. In this review, the recent studies (2005–2009) concerning the cytotoxic activity of saponins have been summarized. The correlations between the structure and the cytotoxicity of both steroid and triterpenoid saponins have been described as well as the most common mechanisms of action. PMID:20835386

  14. Cellular Uptake of Aminoglycosides

    ERIC Educational Resources Information Center

    Steyger, Peter S.

    2005-01-01

    Aminoglycosides exert their cytotoxic effect at three different locations: at the cell surface, in the cytosol, or in the nucleus. At the cell surface, aminoglycoside binding can cause temporary hearing loss, motor paralysis at the neuromuscular junction, ion wasting in kidneys, or analgesia in mechano- and nocioreceptors (touch and pain sensory…

  15. Cytotoxicity of carbon nanotube variants: a comparative in vitro exposure study with A549 epithelial and J774 macrophage cells.

    PubMed

    Kumarathasan, Prem; Breznan, Dalibor; Das, Dharani; Salam, Mohamed A; Siddiqui, Yunus; MacKinnon-Roy, Christine; Guan, Jingwen; de Silva, Nimal; Simard, Benoit; Vincent, Renaud

    2015-03-01

    While production of engineered carbon nanotubes (CNTs) has escalated in recent years, knowledge of risk associated with exposure to these materials remains unclear. We report on the cytotoxicity of four CNT variants in human lung epithelial cells (A549) and murine macrophages (J774). Morphology, metal content, aggregation/agglomeration state, pore volume, surface area and modifications were determined for the pristine and oxidized single-walled (SW) and multi-walled (MW) CNTs. Cytotoxicity was evaluated by cellular ATP content, BrdU incorporation, lactate dehydrogenase (LDH) release, and CellTiter-Blue (CTB) reduction assays. All CNTs were more cytotoxic than respirable TiO2 and SiO2 reference particles. Oxidation of CNTs removed most metallic impurities but introduced surface polar functionalities. Although slopes of fold changes for cytotoxicity endpoints were steeper with J774 compared to A549 cells, CNT cytotoxicity ranking in both cell types was assay-dependent. Based on CTB reduction and BrdU incorporation, the cytotoxicity of the polar oxidized CNTs was higher compared to the pristine CNTs. In contrast, pristine CNTs were more cytotoxic than oxidized CNTs when assessed for cellular ATP and LDH. Correlation analyses between CNTs' physico-chemical properties and average relative potency revealed the impact of metal content and surface area on the potency values estimated using ATP and LDH assays, while surface polarity affected the potency values estimated from CTB and BrdU assays. We show that in order to reliably estimate the risk posed by these materials, in vitro toxicity assessment of CNTs should be conducted with well characterized materials, in multiple cellular models using several cytotoxicity assays that report on distinct cellular processes. PMID:24713075

  16. Modelling cellular behaviour

    NASA Astrophysics Data System (ADS)

    Endy, Drew; Brent, Roger

    2001-01-01

    Representations of cellular processes that can be used to compute their future behaviour would be of general scientific and practical value. But past attempts to construct such representations have been disappointing. This is now changing. Increases in biological understanding combined with advances in computational methods and in computer power make it possible to foresee construction of useful and predictive simulations of cellular processes.

  17. Impaired culture generated cytotoxicity with preservation of spontaneous natural killer-cell activity in cartilage-hair hypoplasia

    SciTech Connect

    Pierce, G.F.; Brovall, C.; Schacter, B.Z.; Polmar, S.H.

    1983-06-01

    Recent studies of cartilage-hair hypoplasia (CHH), a form of short-limbed dwarfism, have shown that all affected individuals have a cellular proliferation defect that results in a cellular immunodeficiency. However, only a minority of CHH individuals suffer from severe, life-threatening infections. For this reason, relevant immune defense mechanisms that may be responsible for maintaining intact host defenses in the majority of CHH individuals were studied. Spontaneous and allogeneic culture-induced (mixed lymphocyte response-MLR) specific and nonspecific (NK-like) cytotoxic mechanisms were analyzed and correlated with lymphocyte subpopulations present in CHH and normal individuals. Spontaneous natural-killer (NK) activity was present at or above normal levels, but culture-induced specific cytotoxicity and NK-like cytotoxicity as well as NK-like activity by T cell lines were significantly reduced in CHH individuals. The generation of radiation-resistant cytotoxicity, which normally occurs during allogeneic MLR, was markedly diminished in CHH, and was correlated with the decreased proliferation observed in CHH cultures. Preservation of spontaneous NK activity and loss of all forms of culture-induced cytotoxicity was associated with an increase in the proportion of lymphocytes bearing a thymic independent NK phenotype, and a significant decrease in thymic derived cytolytic T cell sub-populations in CHH individuals. Therefore, an intact cellular cytotoxic effector mechanism has been identified in CHH (i.e., NK activity).

  18. Oleandrin: A cardiac glycosides with potent cytotoxicity

    PubMed Central

    Kumar, Arvind; De, Tanmoy; Mishra, Amrita; Mishra, Arun K.

    2013-01-01

    Cardiac glycosides are used in the treatment of congestive heart failure and arrhythmia. Current trend shows use of some cardiac glycosides in the treatment of proliferative diseases, which includes cancer. Nerium oleander L. is an important Chinese folk medicine having well proven cardio protective and cytotoxic effect. Oleandrin (a toxic cardiac glycoside of N. oleander L.) inhibits the activity of nuclear factor kappa-light-chain-enhancer of activated B chain (NF-κB) in various cultured cell lines (U937, CaOV3, human epithelial cells and T cells) as well as it induces programmed cell death in PC3 cell line culture. The mechanism of action includes improved cellular export of fibroblast growth factor-2, induction of apoptosis through Fas gene expression in tumor cells, formation of superoxide radicals that cause tumor cell injury through mitochondrial disruption, inhibition of interleukin-8 that mediates tumorigenesis and induction of tumor cell autophagy. The present review focuses the applicability of oleandrin in cancer treatment and concerned future perspective in the area. PMID:24347921

  19. Cytotoxic effects of tebufenozide in vitro bioassays.

    PubMed

    Yu, Xiaoqin; Zhang, Yang; Yang, Mingjun; Guo, Junfu; Xu, Wenping; Gao, Jufang; Li, Yaxiao; Tao, Liming

    2016-07-01

    Tebufenozide is considered an environmentally friendly pesticide due to its specificity on target insects, but the effects on human are well studied. Studies on the toxicity of tebufenozide at molecular and cellular level is poorly understood. The present study reveals non-selective cytotoxic effects of tebufenozide, and the apoptotic mechanism induced by tebufenozide on HeLa and Tn5B1-4 cells. We demonstrate that the viability of HeLa and Tn5B1-4 cells is inhibited by tebufenozide in a time- and concentration-dependent manner. Intracellular biochemical assays showed that tebufenozide-induced apoptosis of two cell lines concurrent with a decrease in the mitochondrial membrane potential and an increase reactive oxygen species generation, the release of cytochrome-c into the cytosol and a marked activation of caspase-3. These results indicate that a mitochondrial-dependent intrinsic pathway contributes to tebufenozide induced apoptosis in HeLa and Tn5B1-4 cells and suggests potential threats to ecosystems and human health. PMID:27043174

  20. Mode of action classification of chemicals using multi-concentration time-dependent cellular response profiles.

    PubMed

    Xi, Zhankun; Khare, Swanand; Cheung, Aaron; Huang, Biao; Pan, Tianhong; Zhang, Weiping; Ibrahim, Fadi; Jin, Can; Gabos, Stephan

    2014-04-01

    In this paper, we present a new statistical pattern recognition method for classifying cytotoxic cellular responses to toxic agents. The advantage of the proposed method is to quickly assess the toxicity level of an unclassified toxic agent on human health by bringing cytotoxic cellular responses with similar patterns (mode of action, MoOA) into the same class. The proposed method is a model-based hierarchical classification approach incorporating principal component analysis (PCA) and functional data analysis (FDA). The cytotoxic cell responses are represented by multi-concentration time-dependent cellular response profiles (TCRPs) which are dynamically recorded by using the xCELLigence real-time cell analysis high-throughput (RTCA HT) system. The classification results obtained using our algorithm show satisfactory discrimination and are validated using biological facts by examining common chemical mechanisms of actions with treatment on human hepatocellular carcinoma cells (HepG2). PMID:24583602

  1. Unambiguous observation of shape effects on cellular fate of nanoparticles

    NASA Astrophysics Data System (ADS)

    Chu, Zhiqin; Zhang, Silu; Zhang, Bokai; Zhang, Chunyuan; Fang, Chia-Yi; Rehor, Ivan; Cigler, Petr; Chang, Huan-Cheng; Lin, Ge; Liu, Renbao; Li, Quan

    2014-03-01

    Cellular fate of nanoparticles is vital to application of nanoparticles to cell imaging, bio-sensing, drug delivery, suppression of drug resistance, gene delivery, and cytotoxicity analysis. However, the current studies on cellular fate of nanoparticles have been controversial due to complications of interplay between many possible factors. By well-controlled experiments, we demonstrated unambiguously that the morphology of nanoparticles independently determined their cellular fate. We found that nanoparticles with sharp shapes, regardless of their surface chemistry, size, or composition, could pierce the membranes of endosomes that carried them into the cells and escape to the cytoplasm, which in turn significantly reduced the cellular excretion rate of the nanoparticles. Such features of sharp-shaped nanoparticles are essential for drug delivery, gene delivery, subcellular targeting, and long-term tracking. This work opens up a controllable, purely geometrical and hence safe, degree of freedom for manipulating nanoparticle-cell interaction, with numerous applications in medicine, bio-imaging, and bio-sensing.

  2. Pyridalyl inhibits cellular protein synthesis in insect, but not mammalian, cell lines.

    PubMed

    Moriya, Koko; Hirakura, Setsuko; Kobayashi, Jun; Ozoe, Yoshihisa; Saito, Shigeru; Utsumi, Toshihiko

    2008-09-01

    To gain insight into the mechanism of action and selectivity of the insecticidal activity of pyridalyl, the cytotoxicity of pyridalyl against various insect and mammalian cell lines was characterized by measuring the inhibition of cellular protein synthesis. When the effect of pyridalyl on the cellular protein synthesis in Sf9 cells was evaluated by measuring the incorporation of [(3)H]leucine, rapid and significant inhibition of protein synthesis was observed. However, pyridalyl did not inhibit protein synthesis in a cell-free protein synthesis system, indicating that pyridalyl does not directly inhibit protein synthesis. No obvious cytotoxicity was observed against any of the mammalian cell lines tested. In the case of insect cell lines, remarkable differences in the cytotoxicity of pyridalyl were observed: the highest cytotoxicity (IC50 mM) was found against Sf9 cells derived from Spodoptera frugiperda, whereas no obvious cytotoxicity was observed against BmN4 cells derived from Bombyx mori. Measurements of the insecticidal activity of pyridalyl against Spodoptera litura and B. mori revealed a correlation between the cytotoxicity against cultured cell lines and the insecticidal activity. From these observations, it was concluded that the selective inhibition of cellular protein synthesis by pyridalyl might contribute significantly to the insecticidal activity and the selectivity of this compound. PMID:18454491

  3. Cytotoxic geranylflavonoids from Bonannia graeca

    PubMed Central

    Rosselli, Sergio; Bruno, Maurizio; Maggio, Antonella; Raccuglia, Rosa Angela; Safder, Muhammad; Lai, Chin-Yu; Bastow, Kenneth F.; Lee, Kuo-Hsiung

    2011-01-01

    The analysis of the aerial parts of Bonannia graeca led to the isolation and characterization of two new polar geranylated flavonoids (6 and 7). The structure elucidation was performed by extensive spectroscopic methods (1D and 2D NMR) and comparison with literature data. All natural flavonoids isolated from B. graeca (1–7) and some synthetic derivatives (8–11) were tested for cytotoxic activity against four human tumor cell lines. Preliminary structure-activity relationship correlations are discussed. PMID:21459391

  4. Cytotoxic diterpenes from Scoparia dulcis.

    PubMed

    Ahsan, Monira; Islam, S K N; Gray, Alexander I; Stimson, William H

    2003-07-01

    Four new labdane-derived diterpenes, iso-dulcinol (1), 4-epi-scopadulcic acid B (2), dulcidiol (4), and scopanolal (5), together with two known diterpenes, dulcinol/scopadulciol (3) and scopadiol (6), were isolated from the aerial parts of Scoparia dulcis. The structures were determined by extensive NMR studies. The crude extracts as well as the pure diterpenes showed cytotoxicity against a panel of six human stomach cancer cell lines. PMID:12880314

  5. Cytotoxic Compounds from Brucea mollis

    PubMed Central

    Tung, Mai Hung Thanh; Đuc, Ho Viet; Huong, Tran Thu; Duong, Nguyen Thanh; Phuong, Do Thi; Thao, Do Thi; Tai, Bui Huu; Kim, Young Ho; Bach, Tran The; Cuong, Nguyen Manh

    2013-01-01

    Ten compounds, including soulameanone (1), isobruceine B (2), 9-methoxy-canthin-6-one (3), bruceolline F (4), niloticine (5), octatriacontan-1-ol (6), bombiprenone (7), α-tocopherol (8), inosine (9), and apigenin 7-O-β-D-glucopyranoside (10), were isolated from the leaves, stems, and roots of Brucea mollis Wall. ex Kurz. Their structures were determined using one-and two-dimensional NMR spectroscopy and mass spectrometry. All compounds were evaluated for their cytotoxic activity against KB (human carcinoma of the mouth), LU-1 (human lung adenocarcinoma), LNCaP (human prostate adeno-carcinoma), and HL-60 (human promyelocytic leukemia) cancer cell lines. Compound 2 showed significant cytotoxic activity against KB, LU-1, LNCaP, and HL-60 cancer cells with IC50 values of 0.39, 0.40, 0.34, and 0.23 μg/mL, respectively. In addition, compounds 3 and 5 showed significant cytotoxic activity against KB, LU-1, LNCaP, and HL-60 cancer cells with IC50 values around 1–4 μg/mL. Compounds 9-methoxycanthin-6-one (3) and niloticine (5) have been discovered for the first time from the Brucea genus. PMID:24106661

  6. Cytotoxic effects of aggregated nanomaterials.

    PubMed

    Soto, Karla; Garza, K M; Murr, L E

    2007-05-01

    This study deals with cytotoxicity assays performed on an array of commercially manufactured inorganic nanoparticulate materials, including Ag, TiO(2), Fe(2)O(3), Al(2)O(3), ZrO(2), Si(3)N(4), naturally occurring mineral chrysotile asbestos and carbonaceous nanoparticulate materials such as multiwall carbon nanotube aggregates and black carbon aggregates. The nanomaterials were characterized by TEM, as the primary particles, aggregates or long fiber dimensions ranged from 2nm to 20microm. Cytotoxicological assays of these nanomaterials were performed utilizing a murine alveolar macrophage cell line and human macrophage and epithelial lung cell lines as comparators. The nanoparticulate materials exhibited varying degrees of cytoxicity for all cell lines and the general trends were similar for both the murine and human macrophage cell lines. These findings suggest that representative cytotoxic responses for humans might be obtained by nanoparticulate exposures to simple murine macrophage cell line assays. Moreover, these results illustrate the utility in performing rapid in vitro assays for cytotoxicity assessments of nanoparticulate materials as a general inquiry of potential respiratory health risks in humans. PMID:17275430

  7. Synergistic effects of ascorbate and sorafenib in hepatocellular carcinoma: New insights into ascorbate cytotoxicity.

    PubMed

    Rouleau, Lauren; Antony, Anil Noronha; Bisetto, Sara; Newberg, Andrew; Doria, Cataldo; Levine, Mark; Monti, Daniel A; Hoek, Jan B

    2016-06-01

    We investigated the mechanism of selective ascorbate-induced cytotoxicity in tumor cells, including Hep G2 cells, compared to primary hepatocytes. H2O2 formation was required for ascorbate cytotoxicity, as extracellular catalase treatment protected tumor cells. H2O2 generated by glucose oxidase treatment also caused cell killing, but treatment with a pharmacologic dose (5-20mM) of ascorbate was significantly more cytotoxic at comparable rates of H2O2 production, suggesting that ascorbate enhanced H2O2 cytotoxicity. This was further supported by the finding that ascorbate at a non-cytotoxic dose (1mM) enhanced cell killing caused by glucose oxidase. Consistent with this conclusion, ascorbate treatment caused deregulation of cellular calcium homeostasis, resulting in massive mitochondrial calcium accumulation. Ascorbate acted synergistically with the chemotherapeutic sorafenib in killing Hep G2 cells, but not primary hepatocytes, suggesting adjuvant ascorbate treatment can broaden sorafenib's therapeutic range. Sorafenib caused mitochondrial depolarization and prevented mitochondrial calcium sequestration. Subsequent ascorbate addition further deregulated cellular calcium homeostasis promoting cell death. Additionally, we present the case of a patient with hepatocellular carcinoma (HCC) who had prolonged regression of a rib metastasis upon combination treatment with ascorbate and sorafenib, indicating that these studies have direct clinical relevance. PMID:27036367

  8. Antibody-directed natural cytotoxicity results in enhanced killing of HIV gp120-coated CEMNKR cells.

    PubMed

    Liu, M; Roberts, R L; Ank, B J; Marmet, J G; Stiehm, E R

    1997-05-01

    Cellular cytotoxicity may be an important defense in the control of HIV progression. In the present study antibodies were attached to peripheral blood mononuclear cells (PBMC) by exposing them to polyethylene glycol and phthalate oil in the presence of HIV human hyperimmune IVIG (HIVIG). The attachment procedure is known as "franking" and the resultant cytotoxicity is termed "antibody-directed." The majority of the cells that are franked with attached HIVIG are CD16+ (Fc gamma RIII), placing them in the natural killer cell population. Franking increased the cytotoxicity of PBMC from both healthy controls and HIV-seropositive patients approximately fourfold compared to conventional antibody-dependent cellular cytotoxicity using CEM cells coated with HIV gp120 antigen as targets. Use of anti-HIV monoclonal antibodies for franking was less efficient than polyclonal HIVIG. The HIVIG-franked PBMC suppressed p24 production of in vitro HIV IIIb-infected human PBMC. The ability of HIVIG to enhance and direct cytotoxicity to HIV targets may suggest a new therapeutic approach to HIV control. PMID:9143374

  9. Comparative cytotoxicity of gambierol versus other marine neurotoxins.

    PubMed

    Cagide, E; Louzao, M C; Espiña, B; Ares, I R; Vieytes, M R; Sasaki, M; Fuwa, H; Tsukano, C; Konno, Y; Yotsu-Yamashita, M; Paquette, L A; Yasumoto, T; Botana, L M

    2011-06-20

    Many microalgae produce compounds that exhibit potent biological activities. Ingestion of marine organisms contaminated with those toxins results in seafood poisonings. In many cases, the lack of toxic material turns out to be an obstacle to make the toxicological investigations needed. In this study, we evaluate the cytotoxicity of several marine toxins on neuroblastoma cells, focusing on gambierol and its effect on cytosolic calcium levels. In addition, we compared the effects of this toxin with ciguatoxin, brevetoxin, and gymnocin-A, with which gambierol shares a similar ladder-like backbone, as well as with polycavernoside A analogue 5, a glycosidic macrolide toxin. For this purpose, different fluorescent dyes were used: Fura-2 to monitor variations in cytosolic calcium levels, Alamar Blue to detect cytotoxicity, and Oregon Green 514 Phalloidin to quantify and visualize modifications in the actin cytoskeleton. Data showed that, while gambierol and ciguatoxin were successful in producing a calcium influx in neuroblastoma cells, gymnocin-A was unable to modify this parameter. Nevertheless, none of the toxins induced morphological changes or alterations in the actin assembly. Although polycavernoside A analogue 5 evoked a sharp reduction of the cellular metabolism of neuroblastoma cells, gambierol scarcely reduced it, and ciguatoxin, brevetoxin, and gymnocin-A failed to produce any signs of cytotoxicity. According to this, sharing a similar polycyclic ether backbone is not enough to produce the same effects on neuroblastoma cells; therefore, more studies should be carried out with these toxins, whose effects may be being underestimated. PMID:21517028

  10. Evaluation of Cytotoxicity and Genotoxicity of Acacia aroma Leaf Extracts

    PubMed Central

    Mattana, C. M.; Cangiano, M. A.; Alcaráz, L. E.; Sosa, A.; Escobar, F.; Sabini, C.; Sabini, L.; Laciar, A. L.

    2014-01-01

    Acacia aroma, native plant from San Luis, Argentina, is commonly used as antiseptic and for healing of wounds. The present study was conducted to investigate the in vitro cytotoxicity and genotoxicity of hot aqueous extract (HAE) and ethanolic extract (EE) of A. aroma. The cytotoxic activity was assayed by neutral red uptake assay on Vero cell. Cell treatment with a range from 100 to 5000 μg/mL of HAE and EE showed that 500 μg/mL and 100 μg/mL were the maximum noncytotoxic concentrations, respectively. The CC50 was 658 μg/mL for EE and 1020 μg/mL for HAE. The genotoxicity was tested by the single-cell gel electrophoresis comet assay. The results obtained in the evaluation of DNA cellular damage exposed to varied concentrations of the HAE showed no significant genotoxic effect at range of 1–20 mg/mL. The EE at 20 mg/mL showed moderate genotoxic effect related to the increase of the DNA percentage contained in tail of the comet; DNA was classified in category 2. At concentrations below 5 mg/mL, the results of cytotoxicity and genotoxicity of aqueous and ethanolic extracts of Acacia aroma guarantee the safety at cell and genomic level. However further studies are needed for longer periods including animal models to confirm the findings. PMID:25530999

  11. Effects of in vivo hydrocortisone on lymphocyte-mediated cytotoxicity

    SciTech Connect

    Katz, P.; Zaytoun, A.M.; Lee, J.H. Jr.

    1984-01-01

    To examine the effects of in vivo hydrocortisone sodium succinate (HC) on natural killer (NK) cell and antibody-dependent cellular cytotoxicity (ADCC), 11 normal adults received a single intravenous bolus of 400 mg hydrocortisone. Lymphocytes were tested for NK activity and ADCC using 51chromium (51Cr)-release and single cell cytotoxicity assays against Molt-4 and sensitized RL O leads to target cells, respectively. Four hours after injection, both NK and ADCC activity were transiently increased in the 51Cr-release system. At 4 hours, there was a twofold increase in the relative frequency of potentially cytotoxic target binding cells but the absolute number of these cells did not change. However, the percentage lysis of bound targets at 4 hours was not altered. These data suggest that: 1) lymphocytes participating in NK and ADCC reactions are refractory to the kinetic and functional effects of HC; 2) the increased lytic activity observed at 4 hours is due to a selective depletion of noncytotoxic cells from the circulation; and 3) NK and ADCC activity did not differ in their responses to HC.

  12. Controlled DNA condensation and targeted cellular imaging by ligand exchange in a polysaccharide-quantum dot conjugate.

    PubMed

    Zhang, Yu-Hui; Zhang, Ying-Ming; Yang, Yang; Chen, Li-Xia; Liu, Yu

    2016-05-01

    A multicomponent supramolecular nanoparticle composed of a polysaccharide-quantum dot conjugate was successfully constructed using a ligand-exchange method, which possessed low cellular cytotoxicity and showed controlled DNA condensation and targeted cellular imaging abilities toward cancer cells. PMID:27064053

  13. Cellular Reflectarray Antenna

    NASA Technical Reports Server (NTRS)

    Romanofsky, Robert R.

    2010-01-01

    The cellular reflectarray antenna is intended to replace conventional parabolic reflectors that must be physically aligned with a particular satellite in geostationary orbit. These arrays are designed for specified geographical locations, defined by latitude and longitude, each called a "cell." A particular cell occupies nominally 1,500 square miles (3,885 sq. km), but this varies according to latitude and longitude. The cellular reflectarray antenna designed for a particular cell is simply positioned to align with magnetic North, and the antenna surface is level (parallel to the ground). A given cellular reflectarray antenna will not operate in any other cell.

  14. Metabolism and cytotoxic effects of phosphatidylcholine hydroperoxide in human hepatoma HepG2 cells.

    PubMed

    Suzuki, Yuuri; Nakagawa, Kiyotaka; Kato, Shunji; Tatewaki, Naoto; Mizuochi, Shunsuke; Ito, Junya; Eitsuka, Takahiro; Nishida, Hiroshi; Miyazawa, Teruo

    2015-03-20

    In this study, we investigated cellular uptake and metabolism of phosphatidylcholine hydroperoxide (PCOOH) in human hepatoma HepG2 cells by high performance liquid chromatography-tandem mass spectrometry, and then evaluated whether PCOOH or its metabolites cause pathophysiological effects such as cytotoxicity and apoptosis. Although we found that most PCOOH was reduced to PC hydroxide in HepG2 cells, the remaining PCOOH caused cytotoxic effects that may be mediated through an unusual apoptosis pathway. These results will enhance our fundamental understanding of how PCOOH, which is present in oxidized low density lipoproteins, is involved in the development of atherosclerosis. PMID:25704087

  15. Investigation of the cytotoxic effects of titanate nanotubes on Caco-2 cells.

    PubMed

    Fenyvesi, Ferenc; Kónya, Zoltán; Rázga, Zsolt; Vecsernyés, Miklós; Kása, Péter; Pintye-Hódi, Klára; Bácskay, Ildikó

    2014-08-01

    Titanate nanotubes can be used as drug delivery systems, but limited information is available on their interactions with intestinal cells. In this study, we investigated the cytotoxicity and cellular uptake of titanate nanotubes on Caco-2 monolayers and found that up to 5 mg/ml concentration, these nanotubes are not cytotoxic and not able to permeate through the intestinal cell layer. Transmission electron microscopic experiments showed that titanate nanotubes are not taken up by cells, only caused a high-density granulation on the surface of the endoplasmic reticulum. According to these results, titanate nanotubes are suitable systems for intestinal drug delivery. PMID:24700297

  16. CELLULAR MAGNESIUM HOMEOSTASIS

    PubMed Central

    Romani, Andrea M.P.

    2011-01-01

    Magnesium, the second most abundant cellular cation after potassium, is essential to regulate numerous cellular functions and enzymes, including ion channels, metabolic cycles, and signaling pathways, as attested by more than 1000 entries in the literature. Despite significant recent progress, however, our understanding of how cells regulate Mg2+ homeostasis and transport still remains incomplete. For example, the occurrence of major fluxes of Mg2+ in either direction across the plasma membrane of mammalian cells following metabolic or hormonal stimuli has been extensively documented. Yet, the mechanisms ultimately responsible for magnesium extrusion across the cell membrane have not been cloned. Even less is known about the regulation in cellular organelles. The present review is aimed at providing the reader with a comprehensive and up-to-date understanding of the mechanisms enacted by eukaryotic cells to regulate cellular Mg2+ homeostasis and how these mechanisms are altered under specific pathological conditions. PMID:21640700

  17. Cytotoxic activity of Origanum dictamnus.

    PubMed

    Chinou, Ioanna; Liolios, Christos; Moreau, Dimitri; Roussakis, Christos

    2007-07-01

    Several extracts of Origanum dictamnus, an endemic plant of Greece growing only in the island of Crete and the bioassay-directed isolated ursolic acid, were tested in vitro against the P388 (murine leukemia) and the human bronchial epidermoid cancer NSCLC-N6 (non small cell lung cancer) cell lines. Both the initial dichloromethane extract and the isolated from it ursolic acid exhibited cytotoxic activity. Ursolic acid was also tested in vivo, on murine ascite leukemia P388, where it exhibited at a dose of 50 mg/kg a marginal antileukemic activity. PMID:17507178

  18. Short-term exposure to engineered nanomaterials affects cellular epigenome

    PubMed Central

    Lu, Xiaoyan; Miousse, Isabelle R.; Pirela, Sandra V.; Melnyk, Stepan; Koturbash, Igor; Demokritou, Philip

    2015-01-01

    Extensive incorporation of engineered nanomaterials (ENMs) into industrial and biomedical applications increases the risks of exposure to these potentially hazardous materials. While the geno- and cytotoxic effects of ENMs have been investigated, the potential of ENMs to target the cellular epigenome remains largely unknown. Our goal was to determine whether or not industry relevant ENMs can affect the epigenome at low cytotoxic doses. A panel of cells relevant to inhalation exposures such as human and murine macrophages (THP-1 and RAW264.7, respectively) and human small airway epithelial cells (SAEC) were exposed to printer-emitted engineered nanoparticles (PEPs), mild steel welding fumes (MS-WF), copper oxide (CuO), and titanium dioxide (TiO2) nanoparticles. Toxicological effects, including cytotoxicity, oxidative stress, and inflammatory responses were assessed, taking into consideration in-vitro dosimetry. The effects of ENMs on cellular epigenome were determined by addressing the global and transposable elements (TEs)-associated DNA methylation and expression of DNA methylation machinery and TEs. The percentage of ENMs-induced cytotoxicity for all cell lines was in the range of 0-15%. Oxidative stress was evident in SAEC after exposure to PEPs and in THP-1 when exposed to CuO. Additionally, exposure to ENMs resulted in modest alterations in DNA methylation of two most abundant TEs in mammalian genomes, LINE-1 and Alu/SINE, their transcriptional reactivation, and decreased expression of DNA methylation machinery in a cell-, dose-, and ENM-dependent manner. These results indicate that exposure to ENMs at environmentally relevant concentrations, aside from the geno- and cytotoxic effects, can also affect the epigenome of target cells. PMID:25938281

  19. Short-term exposure to engineered nanomaterials affects cellular epigenome.

    PubMed

    Lu, Xiaoyan; Miousse, Isabelle R; Pirela, Sandra V; Melnyk, Stepan; Koturbash, Igor; Demokritou, Philip

    2016-01-01

    Extensive incorporation of engineered nanomaterials (ENMs) into industrial and biomedical applications increases the risks of exposure to these potentially hazardous materials. While the geno- and cytotoxic effects of ENMs have been investigated, the potential of ENMs to target the cellular epigenome remains largely unknown. Our goal was to determine whether industry relevant ENMs can affect the epigenome at low cytotoxic doses. A panel of cells relevant to inhalation exposures such as human and murine macrophages (THP-1 and RAW264.7, respectively) and human small airway epithelial cells (SAEC) were exposed to printer-emitted engineered nanoparticles (PEPs), mild steel welding fumes (MS-WF), copper oxide (CuO) and titanium dioxide nanoparticles. Toxicological effects, including cytotoxicity, oxidative stress and inflammatory responses were assessed, taking into consideration in vitro dosimetry. The effects of ENMs on cellular epigenome were determined by addressing the global and transposable elements (TEs)-associated DNA methylation and expression of DNA methylation machinery and TEs. The percentage of ENMs-induced cytotoxicity for all cell lines was in the range of 0-15%. Oxidative stress was evident in SAEC after exposure to PEPs and in THP-1 when exposed to CuO. In addition, exposure to ENMs resulted in modest alterations in DNA methylation of two most abundant TEs in mammalian genomes, LINE-1 and Alu/SINE, their transcriptional reactivation, and decreased expression of DNA methylation machinery in a cell-, dose- and ENM-dependent manner. These results indicate that exposure to ENMs at environmentally relevant concentrations, aside from the geno- and cytotoxic effects, can also affect the epigenome of target cells. PMID:25938281

  20. Cellular Homeostasis and Aging.

    PubMed

    Hartl, F Ulrich

    2016-06-01

    Aging and longevity are controlled by a multiplicity of molecular and cellular signaling events that interface with environmental factors to maintain cellular homeostasis. Modulation of these pathways to extend life span, including insulin-like signaling and the response to dietary restriction, identified the cellular machineries and networks of protein homeostasis (proteostasis) and stress resistance pathways as critical players in the aging process. A decline of proteostasis capacity during aging leads to dysfunction of specific cell types and tissues, rendering the organism susceptible to a range of chronic diseases. This volume of the Annual Review of Biochemistry contains a set of two reviews addressing our current understanding of the molecular mechanisms underlying aging in model organisms and humans. PMID:27050288

  1. Architected Cellular Materials

    NASA Astrophysics Data System (ADS)

    Schaedler, Tobias A.; Carter, William B.

    2016-07-01

    Additive manufacturing enables fabrication of materials with intricate cellular architecture, whereby progress in 3D printing techniques is increasing the possible configurations of voids and solids ad infinitum. Examples are microlattices with graded porosity and truss structures optimized for specific loading conditions. The cellular architecture determines the mechanical properties and density of these materials and can influence a wide range of other properties, e.g., acoustic, thermal, and biological properties. By combining optimized cellular architectures with high-performance metals and ceramics, several lightweight materials that exhibit strength and stiffness previously unachievable at low densities were recently demonstrated. This review introduces the field of architected materials; summarizes the most common fabrication methods, with an emphasis on additive manufacturing; and discusses recent progress in the development of architected materials. The review also discusses important applications, including lightweight structures, energy absorption, metamaterials, thermal management, and bioscaffolds.

  2. Irregular Cellular Learning Automata.

    PubMed

    Esnaashari, Mehdi; Meybodi, Mohammad Reza

    2015-08-01

    Cellular learning automaton (CLA) is a recently introduced model that combines cellular automaton (CA) and learning automaton (LA). The basic idea of CLA is to use LA to adjust the state transition probability of stochastic CA. This model has been used to solve problems in areas such as channel assignment in cellular networks, call admission control, image processing, and very large scale integration placement. In this paper, an extension of CLA called irregular CLA (ICLA) is introduced. This extension is obtained by removing the structure regularity assumption in CLA. Irregularity in the structure of ICLA is needed in some applications, such as computer networks, web mining, and grid computing. The concept of expediency has been introduced for ICLA and then, conditions under which an ICLA becomes expedient are analytically found. PMID:25291810

  3. The anticancer natural product ophiobolin A induces cytotoxicity by covalent modification of phosphatidylethanolamine.

    PubMed

    Chidley, Christopher; Trauger, Sunia A; Birsoy, Kıvanç; O'Shea, Erin K

    2016-01-01

    Phenotypic screens allow the identification of small molecules with promising anticancer activity, but the difficulty in characterizing the mechanism of action of these compounds in human cells often undermines their value as drug leads. Here, we used a loss-of-function genetic screen in human haploid KBM7 cells to discover the mechanism of action of the anticancer natural product ophiobolin A (OPA). We found that genetic inactivation of de novo synthesis of phosphatidylethanolamine (PE) mitigates OPA cytotoxicity by reducing cellular PE levels. OPA reacts with the ethanolamine head group of PE in human cells to form pyrrole-containing covalent cytotoxic adducts and these adducts lead to lipid bilayer destabilization. Our characterization of this unusual cytotoxicity mechanism, made possible by unbiased genetic screening in human cells, suggests that the selective antitumor activity displayed by OPA may be due to altered membrane PE levels in cancer cells. PMID:27403889

  4. Antibody-Dependent Cell-Mediated Cytotoxicity to Hemagglutinin of Influenza A Viruses After Influenza Vaccination in Humans

    PubMed Central

    Zhong, Weimin; Liu, Feng; Wilson, Jason R.; Holiday, Crystal; Li, Zhu-Nan; Bai, Yaohui; Tzeng, Wen-Pin; Stevens, James; York, Ian A.; Levine, Min Z.

    2016-01-01

    Background. Detection of neutralizing antibodies (nAbs) to influenza A virus hemagglutinin (HA) antigens by conventional serological assays is currently the main immune correlate of protection for influenza vaccines However, current prepandemic avian influenza vaccines are poorly immunogenic in inducing nAbs despite considerable protection conferred. Recent studies show that Ab-dependent cell-mediated cytotoxicity (ADCC) to HA antigens are readily detectable in the sera of healthy individuals and patients with influenza infection. Methods. Virus neutralization and ADCC activities of serum samples from individuals who received either seasonal or a stock-piled H5N1 avian influenza vaccine were evaluated by hemagglutination inhibition assay, microneutralization assay, and an improved ADCC natural killer (NK) cell activation assay. Results. Immunization with inactivated seasonal influenza vaccine led to strong expansion of both nAbs and ADCC-mediating antibodies (adccAbs) to H3 antigen of the vaccine virus in 24 postvaccination human sera. In sharp contrast, 18 individuals vaccinated with the adjuvanted H5N1 avian influenza vaccine mounted H5-specific antibodies with strong ADCC activities despite moderate virus neutralization capacity. Strength of HA-specific ADCC activities is largely associated with the titers of HA-binding antibodies and not with the fine antigenic specificity of anti-HA nAbs. Conclusions. Detection of both nAbs and adccAbs may better reflect protective capacity of HA-specific antibodies induced by avian influenza vaccines.

  5. Screening ToxCast™ Phase I Chemicals in a Mouse Embryonic Stem Cell Adherent Cell Differentiation and Cytotoxicity (ACDC) Assay

    EPA Science Inventory

    An Adherent Cell Differentiation and Cytotoxicity (ACDC) in vitro assay with mouse embryonic stem cells was used to screen the ToxCast Phase I chemical library for effects on cellular differentiation and cell number. The U.S. Environmental Protection Agency (EPA) established the ...

  6. Genetic Dominance & Cellular Processes

    ERIC Educational Resources Information Center

    Seager, Robert D.

    2014-01-01

    In learning genetics, many students misunderstand and misinterpret what "dominance" means. Understanding is easier if students realize that dominance is not a mechanism, but rather a consequence of underlying cellular processes. For example, metabolic pathways are often little affected by changes in enzyme concentration. This means that…

  7. Teaching cellular engineering.

    PubMed

    Hammer, Daniel A; Waugh, Richard E

    2006-02-01

    Cellular engineering is one of the fastest growing subdisciplines in the field of Biomedical Engineering. It involves the application of engineering analysis to understand and control cellular behavior, with the ultimate objective of developing novel therapeutic or diagnostic approaches for the clinic or harnessing cellular function for commercial applications. Well-educated students in this area need strong foundational knowledge in engineering science, chemistry, and cell and molecular biology. In undergraduate curricula, the challenge is to include essential engineering skills plus appropriate levels of training in chemistry and biology while satisfying accreditation-mandated breadth in engineering training. At the graduate level, educators must accommodate students with diverse backgrounds and provide them with both a state-of-the-art understanding of the life sciences and the most advanced engineering skills. Engineering curricular content should include mechanics and materials, physical chemistry, transport phenomena, and control theory. Training from faculty with appointments and research programs in the life sciences is generally recommended, and additional life science content should also be integrated within the engineering curriculum. A capstone course in cellular engineering that includes opportunities for students to have hands-on experiences with state-of-the-art laboratory techniques is highly recommended. PMID:16450196

  8. Auxin and Cellular Elongation.

    PubMed

    Velasquez, Silvia Melina; Barbez, Elke; Kleine-Vehn, Jürgen; Estevez, José M

    2016-03-01

    Auxin is a crucial growth regulator in plants. However, a comprehensive understanding of how auxin induces cell expansion is perplexing, because auxin acts in a concentration- and cell type-dependent manner. Consequently, it is desirable to focus on certain cell types to exemplify the underlying growth mechanisms. On the other hand, plant tissues display supracellular growth (beyond the level of single cells); hence, other cell types might compromise the growth of a certain tissue. Tip-growing cells do not display neighbor-induced growth constraints and, therefore, are a valuable source of information for growth-controlling mechanisms. Here, we focus on auxin-induced cellular elongation in root hairs, exposing a mechanistic view of plant growth regulation. We highlight a complex interplay between auxin metabolism and transport, steering root hair development in response to internal and external triggers. Auxin signaling modules and downstream cascades of transcription factors define a developmental program that appears rate limiting for cellular growth. With this knowledge in mind, the root hair cell is a very suitable model system in which to dissect cellular effectors required for cellular expansion. PMID:26787325

  9. The New Cellular Immunology

    ERIC Educational Resources Information Center

    Claman, Henry N.

    1973-01-01

    Discusses the nature of the immune response and traces many of the discoveries that have led to the present state of knowledge in immunology. The new cellular immunology is directing its efforts toward improving health by proper manipulation of the immune mechanisms of the body. (JR)

  10. Cell specific cytotoxicity and uptake of graphene nanoribbons.

    PubMed

    Mullick Chowdhury, Sayan; Lalwani, Gaurav; Zhang, Kevin; Yang, Jeong Y; Neville, Kayla; Sitharaman, Balaji

    2013-01-01

    The synthesis of oxidized graphene nanoribbons (O-GNR) via longitudinal unzipping of carbon nanotubes opens avenues for their further development for a variety of biomedical applications. Evaluation of the cyto- and bio-compatibility is necessary to develop any new material for in vivo biomedical applications. In this study, we report the cytotoxicity screening of O-GNRs water-solubilized with PEG-DSPE (1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino(polyethylene glycol)]), using six different assays, in four representative cell lines; Henrietta Lacks cells (HeLa) derived from cervical cancer tissue, National Institute of Health 3T3 mouse fibroblast cells (NIH-3T3), Sloan Kettering breast cancer cells (SKBR3) and Michigan cancer foundation-7 breast cancer cells (MCF7). These cell lines significantly differed in their response to O-GNR-PEG-DSPE formulations; assessed and evaluated using various endpoints (lactate dehydrogenase (LDH) release, cellular metabolism, lysosomal integrity and cell proliferation) for cytotoxicity. In general, all the cells showed a dose-dependent (10-400 μg/ml) and time-dependent (12-48 h) decrease in cell viability. However, the degree of cytotoxicity was significantly lower in MCF7 or SKBR3 cells compared to HeLa cells. These cells were 100% viable upto 48 h, when incubated at 10 μg/ml O-GNR-PEG-DSPE concentration, and showed decrease in cell viability above this concentration with ~78% of cells viable at the highest concentration (400 μg/ml). In contrast, significant cell death (5-25% cell death depending on the time point, and the assay) was observed for HeLa cells even at a low concentration of 10 μg/ml. The decrease in cell viability was steep with increase in concentration with the CD(50) values ≥ 100 μg/ml depending on the assay, and time point. Transmission electron microscopy of the various cells treated with the O-GNR solutions show higher uptake of the O-GNR-PEG-DSPEs into HeLa cells compared to other cell types

  11. Cell Specific Cytotoxicity and Uptake of Graphene Nanoribbons

    PubMed Central

    Chowdhury, Sayan Mullick; Lalwani, Gaurav; Zhang, Kevin; Yang, Jeong Yun; Neville, Kayla; Sitharaman, Balaji

    2012-01-01

    The synthesis of oxidized graphene nanoribbons (O-GNR) via longitudinal unzipping of carbon nanotubes opens avenues for their further development for a variety of biomedical applications. Evaluation of the cyto- and bio-compatibility is necessary to develop any new material for in vivo biomedical applications. In this study, we report the cytotoxicity screening of O-GNRs water-solubilized with PEG-DSPE (1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino(polyethylene glycol)]), using six different assays, in four representative cell lines; Henrietta Lacks cells (HeLa) derived from cervical cancer tissue, National Institute of Health 3T3 mouse fibroblast cells (NIH-3T3), Sloan Kettering breast cancer cells (SKBR3) and Michigan cancer foundation-7 breast cancer cells (MCF7). These cell lines significantly differed in their response to O-GNR-PEG-DSPE formulations; assessed and evaluated using various endpoints (lactate dehydrogenase (LDH) release, cellular metabolism, lysosomal integrity and cell proliferation) for cytotoxicity. In general, all the cells showed a dose-dependent (10–400 μg/ml) and time-dependent (12–48 h) decrease in cell viability. However, the degree of cytotoxicity was significantly lower in MCF7 or SKBR3 cells compared to HeLa cells. These cells were 100% viable upto 48 hours, when incubated at 10μg/ml O-GNR-PEG-DSPE concentration, and showed decrease in cell viability above this concentration with ~78% of cells viable at the highest concentration (400 μg/ml). In contrast, significant cell death (5–25% cell death depending on the time point, and the assay) was observed for HeLa cells even at a low concentration of 10μg/ml. The decrease in cell viability was steep with increase in concentration with the CD50 values ≥ 100μg/ml depending on the assay, and time point. Transmission electron microscopy of the various cells treated with the O-GNR solutions show higher uptake of the O-GNR-PEG-DSPEs into HeLa cells compared to other cell

  12. Developmental cell death programs license cytotoxic cells to eliminate histocompatible partners.

    PubMed

    Corey, Daniel M; Rosental, Benyamin; Kowarsky, Mark; Sinha, Rahul; Ishizuka, Katherine J; Palmeri, Karla J; Quake, Stephen R; Voskoboynik, Ayelet; Weissman, Irving L

    2016-06-01

    In a primitive chordate model of natural chimerism, one chimeric partner is often eliminated in a process of allogeneic resorption. Here, we identify the cellular framework underlying loss of tolerance to one partner within a natural Botryllus schlosseri chimera. We show that the principal cell type mediating chimeric partner elimination is a cytotoxic morula cell (MC). Proinflammatory, developmental cell death programs render MCs cytotoxic and, in collaboration with activated phagocytes, eliminate chimeric partners during the "takeover" phase of blastogenic development. Among these genes, the proinflammatory cytokine IL-17 enhances cytotoxicity in allorecognition assays. Cellular transfer of FACS-purified MCs from allogeneic donors into recipients shows that the resorption response can be adoptively acquired. Transfer of 1 × 10(5) allogeneic MCs eliminated 33 of 78 (42%) recipient primary buds and 20 of 76 (20.5%) adult parental adult organisms (zooids) by 14 d whereas transfer of allogeneic cell populations lacking MCs had only minimal effects on recipient colonies. Furthermore, reactivity of transferred cells coincided with the onset of developmental-regulated cell death programs and disproportionately affected developing tissues within a chimera. Among chimeric partner "losers," severe developmental defects were observed in asexually propagating tissues, reflecting a pathologic switch in gene expression in developmental programs. These studies provide evidence that elimination of one partner in a chimera is an immune cell-based rejection that operates within histocompatible pairs and that maximal allogeneic responses involve the coordination of both phagocytic programs and the "arming" of cytotoxic cells. PMID:27217570

  13. Multivariate SAR and QSAR of cucurbitacin derivatives as cytotoxic compounds in a human lung adenocarcinoma cell line.

    PubMed

    Lang, Karen L; Silva, Izabella T; Machado, Vanessa R; Zimmermann, Lara A; Caro, Miguel S B; Simões, Cláudia M O; Schenkel, Eloir P; Durán, Fernando J; Bernardes, Lílian S C; de Melo, Eduardo B

    2014-03-01

    This article describes structure-activity relationship (SAR/QSAR) studies on the cytotoxic activity in a human lung adenocarcinoma cell line (A549) of 43 cucurbitacin derivatives. Modeling was performed using the methods partial least squares with discriminant analysis (PLS-DA) and PLS. For both studies, the variables were selected using the ordered predictor selection (OPS) algorithm. The SAR study demonstrated that the presence or absence of cytotoxic activity of the cucurbitacins could be described using information derived from their chemical structures. The QSAR study displayed suitable internal and external predictivity, and the selected descriptors indicated that the observed activity might be related to electrophilic attack on cellular structures or genetic material. This study provides improves the understanding of the cytotoxic activity of cucurbitacins and could be used to propose new cytotoxic agents. PMID:24378396

  14. Cytotoxic Aporphines from Artabotrys crassifolius.

    PubMed

    Kwan, Tan Kok; Shipton, Fiona; Azman, Nadiah Syafiqah Nor; Hossan, Shahadat; Jin, Khoo Ten; Wiart, Christophe

    2016-03-01

    Artabotrys crassifolius Hook. f. & Thomson is a medicinal plant used in Malaysia. The cytotoxic effects of the hexane, chloroform and ethanol extracts of the leaves and bark were examined in vitro against MCF-7, MDA-468 and HCT-116 cells. The chloroform extract of the bark inhibited the growth of all cell lines with GI₅₀ values ranging from 4.2 µg/mL to 9.4 µg/mL. Silica gel column chromatography of this extract yielded artabotrine, liridine, atherospermidine and lysicamine. Artabotrine and lysicamine inhibited the growth of HCT-116 and MCF-7 cells with GI₅₀ values ranging from 3.3 µM to 3.9 µM. These alkaloids were not toxic to human embryonic kidney cells (HEK297) up to a concentration of 50 µg/mL. PMID:27169188

  15. Carbohydrate-based inducers of cellular stress for targeting cancer cells.

    PubMed

    Ndombera, Fidelis T; VanHecke, Garrett C; Nagi, Shima; Ahn, Young-Hoon

    2016-03-01

    Small molecules that block the altered metabolism in cancer or increase the production of reactive oxygen species (ROS) are emerging as potential anti-cancer agents. Considering that various carbohydrates can be used for cellular energetics or protein N-glycosylation of which interruption can lead to cellular stress, we have synthesized and evaluated a library of N-aryl glycosides for induction of ROS and cytotoxicity in H1299 cancer cell line. Two N-aryl glycosides (K8 and H8) were identified that induce about 2-fold induction of ROS and cytotoxicity in H1299 cells. We further showed that the acetylated form of K8 (K8A) activates AMPK, and stabilizes p53 in HEK293 cells, and induce a higher cytotoxicity than 2-deoxy-d-glucose in H1299 cell line. PMID:26832785

  16. Characterization of cadmium uptake and cytotoxicity in human osteoblast-like MG-63 cells

    SciTech Connect

    Levesque, Martine; Martineau, Corine; Jumarie, Catherine; Moreau, Robert

    2008-09-15

    Since bone mass is maintained constant by the balance between osteoclastic bone resorption and osteoblastic bone formation, alterations in osteoblast proliferation and differentiation may disturb the equilibrium of bone remodeling. Exposure to cadmium (Cd) has been associated with the alteration of bone metabolism and the development of osteoporosis. Because little information is available about the direct effects of Cd on osteoblastic cells, we have characterized in vitro the cellular accumulation and cytotoxicity of Cd in human osteoblastic cells. Incubation of osteoblast-like MG-63 cells with increasing concentrations of Cd in serum-free culture medium reduced cell viability in a time- and concentration-dependent manner, suggesting that Cd accumulates in osteoblasts. Consequently, an uptake time-course could be characterized for the cellular accumulation of {sup 109}Cd in serum-free culture medium. In order to characterize the mechanisms of Cd uptake, experiments have been conducted under well-defined metal speciation conditions in chloride and nitrate transport media. The results revealed a preferential uptake of Cd{sup 2+} species. The cellular accumulation and cytotoxicity of Cd increased in the absence of extracellular calcium (Ca), suggesting that Cd may enter the cells in part through Ca channels. However, neither the cellular accumulation nor the cytotoxicity of Cd was modified by voltage-dependent Ca channel (VDCC) modulators or potassium-induced depolarization. Moreover, exposure conditions activating or inhibiting capacitative Ca entry (CCE) failed to modify the cellular accumulation and cytotoxicity of Cd, which excludes the involvement of canonical transient receptor potential (TRPC) channels. The cellular accumulation and cytotoxicity of Cd were reduced by 2-APB, a known inhibitor of the Mg and Ca channel TRPM7 and were increased in the absence of extracellular magnesium (Mg). The inhibition of Cd uptake by Mg and Ca was not additive, suggesting

  17. Exposure to ZnO nanoparticles induces oxidative stress and cytotoxicity in human colon carcinoma cells

    SciTech Connect

    De Berardis, Barbara; Civitelli, Gabriele; Condello, Maria; Lista, Pasquale; Pozzi, Roberta; Arancia, Giuseppe; Meschini, Stefania

    2010-08-01

    Engineered nanoparticles offer great promise in many industrial and biomedical applications, however little information is available about gastrointestinal toxicity. The purpose of this study was to assess the cytotoxicity, oxidative stress, apoptosis and proinflammatory mediator release induced by ZnO nanoparticles on human colon carcinoma LoVo cells. The biological activity of these particles was related to their physico-chemical characteristics. The physico-chemical characteristics were evaluated by analytical electron microscopy. The cytotoxicity was determined by growth curves and water-soluble tetrazolium assay. The reactive oxygen species production, cellular glutathione content, changes of mitochondrial membrane potential and apoptosis cell death were quantified by flow cytometry. The inflammatory cytokines were evaluated by enzyme-linked immunoadsorbent assay. Treatment with ZnO (5 {mu}g/cm{sup 2} corresponding to 11.5 {mu}g/ml) for 24 h induced on LoVo cells a significant decrease of cell viability, H{sub 2}O{sub 2}/OH{center_dot} increase, O2{sup -{center_dot}} and GSH decrease, depolarization of inner mitochondrial membranes, apoptosis and IL-8 release. Higher doses induced about 98% of cytotoxicity already after 24 h of treatment. The experimental data show that oxidative stress may be a key route in inducing the cytotoxicity of ZnO nanoparticles in colon carcinoma cells. Moreover, the study of the relationship between toxicological effects and physico-chemical characteristics of particles suggests that surface area does not play a primary role in the cytotoxicity.

  18. Chemical and enzymatic reductive activation of acylfulvene to isomeric cytotoxic reactive intermediates

    PubMed Central

    Pietsch, Kathryn E.; Neels, James F.; Yu, Xiang; Gong, Jiachang; Sturla, Shana J.

    2011-01-01

    Acylfulvenes, a class of semisynthetic analogues of the sesquiterpene natural product illudin S, are cytotoxic towards cancer cells. The minor structural changes between illudin S and AFs translate to an improved therapeutic window in preclinical cell-based assays and xenograft models. AFs are, therefore, unique tools for addressing the chemical and biochemical basis of cytotoxic selectivity. AFs elicit cytotoxic responses by alkylation of biological targets, including DNA. While AFs are capable of direct alkylation, cytosolic reductive bioactivation to an electrophilic intermediate is correlated with enhanced cytotoxicity. Data obtained in this study illustrates chemical aspects of the process of AF activation. By tracking reaction mechanisms with stable isotope-labeled reagents, enzymatic versus chemical activation pathways for AF were compared for reactions involving the NADPH-dependent enzyme prostaglandin reductase 1 (PTGR1) or sodium borohydride, respectively. These two processes resulted in isomeric products that appear to give rise to similar patterns of DNA modification. The chemically activated isomer has been newly isolated and chemically characterized in this study, including an assessment of its relative stereochemistry, and stability at varying pH and under bioassay conditions. In mammalian cancer cells, this chemically activated analog was shown to not rely on further cellular activation to significantly enhance cytotoxic potency, in contrast to the requirements of AF. On the basis of this study, we anticipate that the chemically activated form of AF will serve as a useful chemical probe for evaluating biomolecular interactions independent of enzyme-mediated activation. PMID:21939268

  19. In vitro cytotoxicity assessment of ulvan, a polysaccharide extracted from green algae.

    PubMed

    Alves, Anabela; Sousa, Rui A; Reis, Rui L

    2013-08-01

    Sustainable exploitation and valorization of natural marine resources represents a highly interesting platform for the development of novel biomaterials, with both economic and environmental benefits. In this context, toxicity data is regarded as a crucial and fundamental knowledge prior to any advances in the application development of natural derived polymers. In the present work, cytotoxicity of ulvan extracted from green algae Ulva lactuca was assessed by means of standard in vitro cytotoxicity assays. Fibroblast-like cells were incubated in the presence of this green algae's polysaccharide, and cell viability was assayed through 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium test. In addition, double stranded DNA and total protein were quantified in order to assess cell number. In order to establish ulvan's non-cytotoxic behaviour, the effect of this polysaccharide on cellular metabolic activity and cell number was directly compared to hyaluronic acid (HA), used as a non-cytotoxic control material. In this study, ulvan demonstrated promising results in terms of cytotoxicity, comparable to the currently used HA, which suggests that ulvan can be considered as non-toxic in the range of concentrations studied. PMID:22972627

  20. New Approach to Investigate the Cytotoxicity of Nanomaterials Using Single Cell Mechanics

    PubMed Central

    2015-01-01

    Current in vitro methods to assess nanomaterial cytotoxicity involve various assays to monitor specific cellular dysfunction, such as metabolic imbalance or inflammation. Although high throughput, fast, and animal-free, these in vitro methods suffer from unreliability and lack of relevance to in vivo situations. New approaches, especially with the potential to reliably relate to in vivo studies directly, are in critical need. This work introduces a new approach, single cell mechanics, derived from atomic force microscopy-based single cell compression. The single cell based approach is intrinsically advantageous in terms of being able to directly correlate to in vivo investigations. Its reliability and potential to measure cytotoxicity is evaluated using known systems: zinc oxide (ZnO) and silicon dioxide (SiO2) nanoparticles (NP) on human aortic endothelial cells (HAECs). This investigation clearly indicates the reliability of single cell compression. For example, ZnO NPs cause significant changes in force vs relative deformation profiles, whereas SiO2 NPs do not. New insights into NPs–cell interactions pertaining to cytotoxicity are also revealed from this single cell mechanics approach, in addition to a qualitative cytotoxicity conclusion. The advantages and disadvantages of this approach are also compared with conventional cytotoxicity assays. PMID:24417356

  1. Structural modification of berberine alkaloids in relation to cytotoxic activity in vitro.

    PubMed

    Orfila, L; Rodríguez, M; Colman, T; Hasegawa, M; Merentes, E; Arvelo, F

    2000-08-01

    The cytotoxicity of two protoberberine alkaloids: berberine and lincangenine, their 8-hydroxy-7,8-dihydro-derivatives and tetrahydroprotoberberine:thaicanine, was evaluated. The cellular responses through the [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide] (MTT) method were measured in Hela (uterus carcinoma), SVKO3 (ovary carcinoma), Hep-2 (larynx carcinoma), primary culture from mouse embryon, and human fibroblast cells at the concentration: 10-1000 ppm (microg/ml) for 24 h. Berberine showed the highest cytotoxicity among the compounds tested, giving LC50 values for all cell lines at the concentration of 10 ppm. The results indicated that the cytotoxicity was notably decreased by structural changes, i.e. by modulation of the planarity caused by the introduction of hydroxyl group at C-8 and concomitant saturation of double bond between N-C8 in protoberberine molecules. In the case of berberine, the cytotoxic effect changed from 98.8 (berberine) to 39% for 8-hydroxydihydroberberine at the concentration of 100 ppm in Hela cells line. The same effect was observed with lincangenine and 8-OH-lincangenine (cytotoxicities 70 and 25%, respectively, at 1000 ppm in SVKO3 cells). On the other hand, these compounds showed a low selectivity for the different human cancer cell lines tested. PMID:10940582

  2. Fabrication of cellular materials

    NASA Astrophysics Data System (ADS)

    Prud'homme, Robert K.; Aksay, Ilhan A.; Garg, Rajeev

    1996-02-01

    Nature uses cellular materials in applications requiring strength while, simultaneously, minimizing raw materials requirements. Minimizing raw materials is efficient both in terms of the energy expended by the organism to synthesize the structure and in terms of the strength- to-weight ratio of the structure. Wood is the most obvious example of cellular bio-materials, and it is the focus of other presentations in this symposium. The lightweight bone structure of birds is another excellent example where weight is a key criterion. The anchoring foot of the common muscle [Mytilus edulis] whereby it attaches itself to objects is a further example of a biological system that uses a foam to fill space and yet conserve on raw materials. In the case of the muscle the foam is water filled and the foot structure distributes stress over a larger area so that the strength of the byssal thread from which it is suspended is matched to the strength of interfacial attachment of the foot to a substrate. In these examples the synthesis and fabrication of the cellular material is directed by intercellular, genetically coded, biochemical reactions. The resulting cell sizes are microns in scale. Cellular materials at the next larger scale are created by organisms at the next higher level of integration. For example an African tree frog lays her eggs in a gas/fluid foam sack she builds on a branch overhanging a pond. The outside of the foam sack hardens in the sun and prevents water evaporation. The foam structure minimizes the amount of fluid that needs to be incorporated into the sack and minimizes its weight. However, as far as the developing eggs are concerned, they are in an aqueous medium, i.e. the continuous fluid phase of the foam. After precisely six days the eggs hatch, and the solidified outer wall re-liquefies and dumps the emerging tadpoles into the pond below. The bee honeycomb is an example of a cellular material with exquisite periodicity at millimeter length scales. The

  3. Cytotoxicity and genotoxicity of urban particulate matter in mammalian cells

    PubMed Central

    Dumax-Vorzet, Audrey F.; Tate, M.; Walmsley, Richard; Elder, Rhod H.; Povey, Andrew C.

    2015-01-01

    Ambient air particulate matter (PM)-associated reactive oxygen species (ROS) have been linked to a variety of altered cellular outcomes. In this study, three different PM samples from diesel exhaust particles (DEPs), urban dust standard reference material SRM1649a and air collected in Manchester have been tested for their ability to oxidise DNA in a cell-free assay, to increase intracellular ROS levels and to induce CYP1A1 gene expression in mammalian cells. In addition, the cytotoxicity and genotoxicity of PM were assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and alkaline comet assay, respectively. All PM samples catalysed the Fenton reaction in a cell-free assay, but only DEP resulted in the generation of ROS as measured by dichlorodihydrofluorescein diacetate oxidation in mammalian cells. However, there was no evidence that increased ROS was a consequence of polycyclic aromatic hydrocarbon metabolism via CYP1A1 induction as urban dust, the Manchester dust samples but not DEP-induced CYP1A1 expression. Urban dust was more cytotoxic in murine embryonic fibroblasts (MEFs) than the other PM samples and also induced expression of GADD45a in the GreenScreen Human Cell assay without S9 activation suggesting the presence of a direct-acting genotoxicant. Urban dust and DEP produced comparable levels of DNA damage, as assessed by the alkaline comet assay, in MEFs at higher levels than those induced by Manchester PM. In conclusion, results from the cytotoxic and genotoxic assays are not consistent with ROS production being the sole determinant of PM-induced toxicity. This suggests that the organic component can contribute significantly to this toxicity and that further work is required to better characterise the extent to which ROS and organic components contribute to PM-induced toxicity. PMID:26113525

  4. Cytotoxicity of methoctramine and methoctramine-related polyamines.

    PubMed

    Zini, Maddalena; Passariello, Catherine L; Gottardi, Davide; Cetrullo, Silvia; Flamigni, Flavio; Pignatti, Carla; Minarini, Anna; Tumiatti, Vincenzo; Milelli, Andrea; Melchiorre, Carlo; Stefanelli, Claudio

    2009-10-30

    Methoctramine and its analogues are polymethylene tetramines that selectively bind to a variety of receptor sites. Although these compounds are widely used as pharmacological tools for receptor characterization, the toxicological properties of these polyamine-based structures are largely unknown. We have evaluated the cytotoxic effects of methoctramine and related symmetrical analogues differing in polymethylene chain length between the inner nitrogens against a panel of cell lines. Methoctramine caused cell death only at high micromolar concentrations, whereas its pharmacological action is exerted at nanomolar level. Increasing the spacing between the inner nitrogen atoms resulted in a significative increase in cytotoxicity. In particular, an elevated cytotoxicity is associated to a methylene chain length of 12 units dividing the inner amine functions (compound 5). H9c2 cardiomyoblasts were the most sensitive cells, followed by SH-SY5Y neuroblastoma, whereas HL60 leukaemia cells were much more resistant. Methoctramine and related compounds down-regulated ornithine decarboxylase, the first enzyme of polyamine biosynthesis even at non-toxic concentration. Further, methoctramine and compound 5 caused a limited up-regulation of spermine/spermidine N-acetyltransferase, suggesting that interference in polyamine metabolism is not a primary mechanism of toxicity. Methoctramine and its analogues bound to DNA with a higher affinity than spermine, but the correlation with their toxic effect was poor. The highly toxic compound 5 killed the cells in the absence of caspase activation and caused an increase in p53 expression and ERK1/2 phosphorylation. Compound 5 was directly oxidized by cell homogenates producing hydrogen peroxide and its toxic effect was partially subdued by the inhibition of its uptake, by the NMDA ligand MK-801, and by the antioxidant N-acetylcysteine, suggesting that compound 5 can act at different cellular levels and lead to oxidative stress. PMID:19576191

  5. Susceptibility of rhabdomyosarcoma cells to macrophage-mediated cytotoxicity.

    PubMed

    Herrmann, Delia; Seitz, Guido; Fuchs, Jörg; Armeanu-Ebinger, Sorin

    2012-05-01

    The prognosis of advanced stage rhabdomyosarcoma (RMS) is still sobering. In recent years, outcome has not been further improved by conventional therapy. Therefore, novel treatment options such as macrophage-directed immunotherapy have to be investigated. The aim of this study was to analyze the phagocytosis of RMS cells by macrophages and to modulate the susceptibility using monoclonal antibodies and cytotoxic drugs.   Expression of the macrophage activating ligand calreticulin and CD47, the counterpart of the inhibitory receptor SIRPα, was analyzed with Affymetrix mRNA expression arrays and immunohistochemistry on 11 primary RMS samples. Results were verified in two RMS cell lines using flow cytometry and immunocytochemistry. Macrophage cytotoxic activity was quantified by a MTT colorimetric assay in co-culture experiments of RMS cells with monocyte-derived, GM-CSF stimulated macrophages. Gene expression analysis and immunohistochemistry revealed a high expression of CD47 and calreticulin in alveolar and embryonal RMS tissue specimens. Extracellular expression of CD47 on RMS cell lines was confirmed by flow cytometry, whereas calreticulin was exclusively detected in the endoplasmatic reticulum. After co-culturing of RMS cells with macrophages, viability dropped to 50-60%. Macrophage-mediated cytotoxicity was not influenced by a blocking antibody against CD47. However, susceptibility was significantly enhanced after pre-treatment of RMS cells with the anthracycline drug doxorubicin. Furthermore, translocation of calreticulin onto the cell surface was detected by flow cytometry. The immunologic effect of doxorubicin may improve the efficacy of adoptive cellular immunotherapy and chemotherapy of childhood RMS. PMID:22737603

  6. Cellular growth in biofilms

    SciTech Connect

    Wood, B.D.; Whitaker, S.

    1999-09-20

    In this paper the authors develop a macroscopic evolutionary equation for the growth of the cellular phase starting from a microscopic description of mass transport and a simple structured model for product formation. The methods of continuum mechanics and volume averaging are used to develop the macroscopic representation by carefully considering the fluxes of chemical species that pertain to cell growth. The concept of structured models is extended to include the transport of reacting chemical species at the microscopic scale. The resulting macroscopic growth model is similar in form to previously published models for the transport of a single substrate and electron donor and for the production of cellular mass and exopolymer. The method of volume averaging indicated under what conditions the developed growth model is valid and provides an explicit connection between the relevant microscopic model parameters and their corresponding macroscopic counterparts.

  7. Cytotoxic and antitumour principles from Ixora coccinea flowers.

    PubMed

    Latha, P G; Panikkar, K R

    1998-08-14

    The antitumour activity of Ixora coccinea L. (Rubiaceae) flowers was studied in comparison to intraperitoneally transplanted Dalton's lymphoma (ascitic and solid tumours) and Ehrlich ascites carcinoma (EAC) tumours in mice. Intraperitoneal administration of 200 mg/kg of the active fraction (AF) of the I. coccinea flower increased the life-span of DLA and EAC ascitic tumour-bearing mice by 113 and 68%, respectively. The AF showed less activity against solid tumours (DLA) as compared to ascitic tumours. The same active fraction showed 50% cytotoxicity to DLA, EAC and Sarcoma-180 (S-180) cells in vitro at concentrations of 18, 60 and 25 microg/ml, respectively. It was not toxic to normal lymphocytes, whereas it was toxic to transformed lymphocytes from leukaemic patients, acute lymphoblastic leukaemia (ALL) and chronic myelogenous leukaemia (CML) and K-562 suspension cell cultures. The AF inhibited tritiated thymidine incorporation in cellular DNA. PMID:9751274

  8. Cytotoxic T cell adjuvant effects of three Salmonella enterica flagellins

    PubMed Central

    Braga, Catarina J.M.; Massis, Liliana M.; Alencar, Bruna C.G.; Rodrigues, Maurício M.; Sbrogio-Almeida, M.E.; Ferreira, Luís C.S.

    2008-01-01

    Bacterial flagellins are important virulence-associated factors and strong inducers of inflammatory responses in mammalian hosts. Flagellins have also been investigated as potential vaccine adjuvants, either for induction of humoral or cellular immune responses, to different target antigens. In this study we investigated the adjuvant properties of three Salmonella enterica flagellins types (FliCd, FliCi and FljB) to an ovalbumin-derived CD8+ T cell-restricted epitope (OVA257–264). Although mice immunized with the three tested flagellins elicited antigen-specific activated CD8+ T cells, only animals immunized with FliCi and FliCd flagellins admixed with ovalbumin mounted specific in vivo cytotoxic responses to peptide-pulsed target cells. The present results indicate that Salmonella flagellins are endowed with type-specific adjuvant effects toward murine CD8+ T cells, a feature that may impact their use as adjuvants for prophylatic or therapeutic vaccines. PMID:24031176

  9. Cellular dysfunction in sepsis.

    PubMed

    Singer, Mervyn

    2008-12-01

    Cellular dysfunction is a commonplace sequelum of sepsis and other systemic inflammatory conditions. Impaired energy production (related to mitochondrial inhibition, damage, and reduced protein turnover) appears to be a core mechanism underlying the development of organ dysfunction. The reduction in energy availability appears to trigger a metabolic shutdown that impairs normal functioning of the cell. This may well represent an adaptive mechanism analogous to hibernation that prevents a massive degree of cell death and thus enables eventual recovery in survivors. PMID:18954700

  10. Radiolabeled cellular blood elements

    SciTech Connect

    Thakur, M.L.; Ezikowitz, M.D.; Hardeman, M.R.

    1985-01-01

    This book contains papers delivered by guest lectures and participants at the Advanced Study Institute's colloquium on Radiolabeled Cellular Blood Elements at Maratea, Italy on August 29, to September 9, 1982. The book includes chapters on basic cell physiology and critical reviews of data and experience in the preparation and use of radiolabeled cells, as well as reports on very recent developments, from a faculty that included experts on cell physiology in health and disease and on the technology of in vivo labeling.

  11. Cytotoxic components of bardanae fructus (goboshi).

    PubMed

    Moritani, S; Nomura, M; Takeda, Y; Miyamoto, K

    1996-11-01

    Bardanae Furctus (Goboshi) extract showed potent in vitro cytotoxicity and in vivo antitumor activity against human hepatoma HepG2 cells and mouse sarcoma 180 cells, respectively. In this study, the cytotoxicities of four fractions and three major components (arctiin, arctigenin, and chlorogenic acid) isolated from Goboshi extract were examined. Arctiin and arctigenin, which were contained in the ethylacetate fraction and n-butanol fraction, respectively, showed strong cytotoxicity against HepG2 cells, but little toxicity against Chang liver cells. Chlorogenic acid isolated from the water fraction did not affect the viability of these cells. The cytotoxicity of arctigenin against Chang liver cells was markedly potentiated by treatment with glutathione (GSH) synthesis inhibitor, L-buthionine-(S,R)-sulfoximine (BSO). On the other hand, in HepG2 cells, the cytotoxicity of arctigenin was hardly changed by BSO. The cytotoxicity of arctigenin against HepG2 cells increased in an exposure-time dependent manner. These characteristics of arctigenin were similar to those of Goboshi extract, as previously observed. We therefore conclude that the principal cytotoxic components of Goboshi extract are arctiin and its aglycone arctigenin. PMID:8951177

  12. Cytotoxic effects of bangladeshi medicinal plant extracts.

    PubMed

    Uddin, Shaikh J; Grice, I Darren; Tiralongo, Evelin

    2011-01-01

    To investigate the cytotoxic effect of some Bangladeshi medicinal plant extracts, 16 Bangladeshi medicinal plants were successively extracted with n-hexane, dichloromethane, methanol and water. The methanolic and aqueous extracts were screened for cytotoxic activity against healthy mouse fibroblasts (NIH3T3) and three human cancer-cell lines (gastric: AGS; colon: HT-29; and breast: MDA-MB-435S) using the MTT assay. Two methanolic extracts (Hygrophila auriculata and Hibiscus tiliaceous) and one aqueous extract (Limnophila indica) showed no toxicity against healthy mouse fibroblasts, but selective cytotoxicity against breast cancer cells (IC(50) 1.1-1.6 mg mL(-1)). Seven methanolic extracts from L. indica, Clerodendron inerme, Cynometra ramiflora, Xylocarpus moluccensis, Argemone mexicana, Ammannia baccifera and Acrostichum aureum and four aqueous extracts from Hygrophila auriculata, Bruguiera gymnorrhiza, X. moluccensis and Aegiceras corniculatum showed low toxicity (IC(50) > 2.5 mg mL(-1)) against mouse fibroblasts but selective cytotoxicity (IC(50) 0.2-2.3 mg mL(-1)) against different cancer cell lines. The methanolic extract of Blumea lacera showed the highest cytotoxicity (IC(50) 0.01-0.08 mg mL(-1)) against all tested cell lines among all extracts tested in this study. For some of the plants their traditional use as anticancer treatments correlates with the cytotoxic results, whereas for others so far unknown cytotoxic activities were identified. PMID:19706693

  13. Cytotoxic Effects of Bangladeshi Medicinal Plant Extracts

    PubMed Central

    Uddin, Shaikh J.; Grice, I. Darren; Tiralongo, Evelin

    2011-01-01

    To investigate the cytotoxic effect of some Bangladeshi medicinal plant extracts, 16 Bangladeshi medicinal plants were successively extracted with n-hexane, dichloromethane, methanol and water. The methanolic and aqueous extracts were screened for cytotoxic activity against healthy mouse fibroblasts (NIH3T3) and three human cancer-cell lines (gastric: AGS; colon: HT-29; and breast: MDA-MB-435S) using the MTT assay. Two methanolic extracts (Hygrophila auriculata and Hibiscus tiliaceous) and one aqueous extract (Limnophila indica) showed no toxicity against healthy mouse fibroblasts, but selective cytotoxicity against breast cancer cells (IC50 1.1–1.6 mg mL−1). Seven methanolic extracts from L. indica, Clerodendron inerme, Cynometra ramiflora, Xylocarpus moluccensis, Argemone mexicana, Ammannia baccifera and Acrostichum aureum and four aqueous extracts from Hygrophila auriculata, Bruguiera gymnorrhiza, X. moluccensis and Aegiceras corniculatum showed low toxicity (IC50 > 2.5 mg mL−1) against mouse fibroblasts but selective cytotoxicity (IC50 0.2–2.3 mg mL−1) against different cancer cell lines. The methanolic extract of Blumea lacera showed the highest cytotoxicity (IC50 0.01–0.08 mg mL−1) against all tested cell lines among all extracts tested in this study. For some of the plants their traditional use as anticancer treatments correlates with the cytotoxic results, whereas for others so far unknown cytotoxic activities were identified. PMID:19706693

  14. Predictability in cellular automata.

    PubMed

    Agapie, Alexandru; Andreica, Anca; Chira, Camelia; Giuclea, Marius

    2014-01-01

    Modelled as finite homogeneous Markov chains, probabilistic cellular automata with local transition probabilities in (0, 1) always posses a stationary distribution. This result alone is not very helpful when it comes to predicting the final configuration; one needs also a formula connecting the probabilities in the stationary distribution to some intrinsic feature of the lattice configuration. Previous results on the asynchronous cellular automata have showed that such feature really exists. It is the number of zero-one borders within the automaton's binary configuration. An exponential formula in the number of zero-one borders has been proved for the 1-D, 2-D and 3-D asynchronous automata with neighborhood three, five and seven, respectively. We perform computer experiments on a synchronous cellular automaton to check whether the empirical distribution obeys also that theoretical formula. The numerical results indicate a perfect fit for neighbourhood three and five, which opens the way for a rigorous proof of the formula in this new, synchronous case. PMID:25271778

  15. Probabilistic cellular automata.

    PubMed

    Agapie, Alexandru; Andreica, Anca; Giuclea, Marius

    2014-09-01

    Cellular automata are binary lattices used for modeling complex dynamical systems. The automaton evolves iteratively from one configuration to another, using some local transition rule based on the number of ones in the neighborhood of each cell. With respect to the number of cells allowed to change per iteration, we speak of either synchronous or asynchronous automata. If randomness is involved to some degree in the transition rule, we speak of probabilistic automata, otherwise they are called deterministic. With either type of cellular automaton we are dealing with, the main theoretical challenge stays the same: starting from an arbitrary initial configuration, predict (with highest accuracy) the end configuration. If the automaton is deterministic, the outcome simplifies to one of two configurations, all zeros or all ones. If the automaton is probabilistic, the whole process is modeled by a finite homogeneous Markov chain, and the outcome is the corresponding stationary distribution. Based on our previous results for the asynchronous case-connecting the probability of a configuration in the stationary distribution to its number of zero-one borders-the article offers both numerical and theoretical insight into the long-term behavior of synchronous cellular automata. PMID:24999557

  16. Quantum cellular automata

    NASA Astrophysics Data System (ADS)

    Porod, Wolfgang; Lent, Craig S.; Bernstein, Gary H.

    1994-06-01

    The Notre Dame group has developed a new paradigm for ultra-dense and ultra-fast information processing in nanoelectronic systems. These Quantum Cellular Automata (QCA's) are the first concrete proposal for a technology based on arrays of coupled quantum dots. The basic building block of these cellular arrays is the Notre Dame Logic Cell, as it has been called in the literature. The phenomenon of Coulomb exclusion, which is a synergistic interplay of quantum confinement and Coulomb interaction, leads to a bistable behavior of each cell which makes possible their use in large-scale cellular arrays. The physical interaction between neighboring cells has been exploited to implement logic functions. New functionality may be achieved in this fashion, and the Notre Dame group invented a versatile majority logic gate. In a series of papers, the feasibility of QCA wires, wire crossing, inverters, and Boolean logic gates was demonstrated. A major finding is that all logic functions may be integrated in a hierarchial fashion which allows the design of complicated QCA structures. The most complicated system which was simulated to date is a one-bit full adder consisting of some 200 cells. In addition to exploring these new concepts, efforts are under way to physically realize such structures both in semiconductor and metal systems. Extensive modeling work of semiconductor quantum dot structures has helped identify optimum design parameters for QCA experimental implementations.

  17. In vitro interaction of lithotripter shock waves and cytotoxic drugs.

    PubMed Central

    Gambihler, S.; Delius, M.

    1992-01-01

    The effect of a combination of lithotripter shock waves and cytotoxic drugs was examined in vitro. L1210 cells in suspension were exposed to shock waves during incubation with cislatin, doxorubicin, daunorubicin, THP-doxorubicin, or aclacinomycin. Proliferation was determined using the 3-4,5 dimethylthiazol-2,5 diphenyl tetrazolium bromide assay. Dose enhancement ratios were calculated for each drug in order to determine the effect of the additional exposure to shock waves. In addition, partition coefficients and IC50s of the drugs were determined. It was found, that the dose enhancement ratios increased for the drugs with decreasing cytotoxicity. The effect of all five drugs was enhanced by shock waves to a higher degree at 7 min incubation as compared to 50 min incubation. The effect of cisplatin was most significantly enhanced, with a dose enhancement ratio of 6.7 at 7 min incubation. The enhancement increased with the operating voltage used for generating the shock waves, and was only present when cells were exposed to shock waves during the incubation with the drug. An increase in cellular membrane permeability is proposed as the mechanism of interaction between shock waves and drugs. PMID:1637679

  18. Cytotoxicity of Salvia miltiorrhiza Against Multidrug-Resistant Cancer Cells.

    PubMed

    Wu, Ching-Fen; Bohnert, Stefan; Thines, Eckhard; Efferth, Thomas

    2016-01-01

    Salvia miltiorrhiza Bunge (Lamiaceae) is a well-known Chinese herb that possesses numerous therapeutic activities, including anticancer effects. In this study, the cytotoxicity and the biological mechanisms of S. miltiorrhiza (SM) root extract on diverse resistant and sensitive cancer cell lines were investigated. CEM/ADR5000 cells were 1.68-fold resistant to CCRF-CEM cells, while HCT116 (p53[Formula: see text] and U87.MG[Formula: see text]EGFR cells were hypersensitive (collateral sensitive) compared to their parental cells. SM root extract stimulated ROS generation, cell cycle S phase arrest and apoptosis. The induction of the intrinsic apoptotic pathway was validated by increased cleavage of caspase 3, 7, 9 and poly ADP-ribose polymerase (PARP). MAP kinases including JNK, ERK1/2 and p38 were obviously phosphorylated and nuclear P65 was downregulated upon SM treatment. Transcriptome-wide COMPARE analysis revealed that the expression of encoding genes with diverse functions were associated with the cellular response to cryptotanshinone, one of the main constituents of SM root extract. In conclusion, SM root extract exerted profound cytotoxicity towards various sensitive and resistant cancer cells and induced the intrinsic apoptotic pathway. PMID:27222067

  19. Lipopolysaccharide Attenuates the Cytotoxicity of Resveratrol in Transformed Mouse Macrophages.

    PubMed

    Achy-Brou, Christelle A Adiabouah; Billack, Blase

    2016-09-01

    Resveratrol and pterostilbene are natural products that are present in plants and have been incorporated into various dietary supplements. Numerous beneficial pharmacologic effects have been reported for these stilbenes; however, the mechanism by which these compounds exert a cytotoxic effect in RAW 264.7 macrophages has not been well characterized. We have previously described that resveratrol is toxic to these tumor-derived macrophages and that stimulation with lipopolysaccharide (LPS) reduces resveratrol toxicity via a mechanism that involves activation of toll like receptor 4. In the present work, we examined the cellular and molecular effects of resveratrol and the related compound pterostilbene by determining cell viability and caspase 3 activity in control and LPS-stimulated RAW 264.7 macrophages incubated with these stilbenes for 24 h. We found that LPS stimulation reduced the cytotoxicity of resveratrol but not of pterostilbene in these cells. When examined for effects on caspase 3 activation after a 24 h incubation, resveratrol and pterostilbene were each found to separately and significantly increase caspase 3 activity in these cells. LPS stimulation prevented caspase 3 activation by pterostilbene and reduced caspase 3 activation by resveratrol in RAW 264.7 macrophages. The data presented here indicate that LPS induces a phenotype switch in tumor-derived RAW 264.7 macrophages in which cells experiencing LPS in the presence of resveratrol or pterostilbene become less likely to activate the pro-apoptotic factor caspase 3. PMID:27277074

  20. In vitro cytotoxicity and phototoxicity study of cosmetics colorants.

    PubMed

    Tomankova, K; Kejlova, K; Binder, S; Daskova, A; Zapletalova, J; Bendova, H; Kolarova, H; Jirova, D

    2011-09-01

    The aim of the work was early identification of preventable risk factors connected with the consumers usage of products of everyday use, such as cosmetics, toys and children products, and other materials intended for contact with human skin. The risk factor is represented by substances with irritation potential and subsequent possible sensitisation, resulting in negative impact on human physical and psychical health with social and societal consequences. The legislation for cosmetics, chemical substances and other products requires for hazard identification the application of alternative toxicological methods in vitro without the use of animals. For this reason we used a battery of alternative assays in vitro, based on cell cultures. Progressive methods of molecular biology, based on fluorimetry and fluorescence, were employed for identification of early morphological and functional changes on cellular level. Four colorants frequently used in cosmetics (P-WS Caramel, Chlorophyllin, Unicert Red K 7054-J and Unicert Red K 7008-J) were tested on cell line NIH3T3 (mouse fibroblast cell) and 3T3 Balb/c with/without UV irradiation (dose 5 J cm(-2)). Fluorescence methods for the study of cell damage using fluorescence probes offer results for the evaluation of cytotoxicity and cell viability of adherent cells. We detected intracellular production of ROS investigated by molecular probe CM-H(2)DCFDA, which is primarily sensitive to the increased production of hydrogen peroxide or its downstream products. Toxic effects on the cellular level were identified by viability tests using Neutral Red uptake and MTT assay, where the live cells reduce yellow soluble 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) to insoluble formazan crystals. The reaction was investigated on mitochondrial membrane of living cells and the type of cell death was determined using Apoptosis detection kit. Cytotoxicity tests revealed health risks of using Chlorophyllin and Unicert Red

  1. Cytotoxicity of monodispersed chitosan nanoparticles against the Caco-2 cells

    SciTech Connect

    Loh, Jing Wen; Saunders, Martin; Lim, Lee-Yong

    2012-08-01

    Published toxicology data on chitosan nanoparticles (NP) often lack direct correlation to the in situ size and surface characteristics of the nanoparticles, and the repeated NP assaults as experienced in chronic use. The aim of this paper was to breach these gaps. Chitosan nanoparticles synthesized by spinning disc processing were characterised for size and zeta potential in HBSS and EMEM at pHs 6.0 and 7.4. Cytotoxicity against the Caco-2 cells was evaluated by measuring the changes in intracellular mitochondrial dehydrogenase activity, TEER and sodium fluorescein transport data and cell morphology. Cellular uptake of NP was observed under the confocal microscope. Contrary to established norms, the collective data suggest that the in vitro cytotoxicity of NP against the Caco-2 cells was less influenced by positive surface charges than by the particle size. Particle size was in turn determined by the pH of the medium in which the NP was dispersed, with the mean size ranging from 25 to 333 nm. At exposure concentration of 0.1%, NP of 25 ± 7 nm (zeta potential 5.3 ± 2.8 mV) was internalised by the Caco-2 cells, and the particles were observed to inflict extensive damage to the intracellular organelles. Concurrently, the transport of materials along the paracellular pathway was significantly facilitated. The Caco-2 cells were, however, capable of recovering from such assaults 5 days following NP removal, although a repeat NP exposure was observed to produce similar effects to the 1st exposure, with the cells exhibiting comparable resiliency to the 2nd assault. -- Highlights: ► Chitosan nanoparticles reduced mitochondrial dehydrogenase activity. ► Cellular uptake of chitosan nanoparticles was observed. ► Chitosan nanoparticles inflicted extensive damage to the cell morphology. ► The transport of materials along the paracellular pathway was facilitated.

  2. Sensitive colorimetric cytotoxicity measurement using alarmar blue.

    PubMed

    Page, B; Page, M

    1995-01-01

    Cytotoxicity testing of anticancer drugs requires techniques which are sensitive, reproductible and applicable to large scale testing using automated instruments. End point staining of cells or viability stains are reliable but they are often not sensitive enough or not suitable for automation. We have already described a fluorometric cytotoxicity assay using a non fluorescent substrate, Alarmar Blue, which upon reduction in living cells, yields a fluorescent product. This assay is sensitive and highly reproductible but it is limited since automated fluorescent plate readers are not found frequently in laboratories. The conditions are now described for using Alamar Blue as a substrate in a colorimetric cytotoxicity assay. This new economical assay could be used with advantage for large scale screening of cytotoxic agents in microtitration plates. PMID:21597689

  3. Cell Death Mechanisms Induced by Cytotoxic Lymphocytes

    PubMed Central

    Chávez-Galán, L; Arenas-Del Angel, M C; Zenteno, E; Chávez, R; Lascurain, R

    2009-01-01

    One of the functions of the immune system is to recognize and destroy abnormal or infected cells to maintain homeostasis. This is accomplished by cytotoxic lymphocytes. Cytotoxicity is a highly organized multifactor process. Here, we reviewed the apoptosis pathways induced by the two main cytotoxic lymphocyte subsets, natural killer (NK) cells and CD8+ T cells. In base to recent experimental evidence, we reviewed NK receptors involved in recognition of target-cell, as well as lytic molecules such as perforin, granzymes-A and -B, and granulysin. In addition, we reviewed the Fas-FasL intercellular linkage mediated pathway, and briefly the cross-linking of tumor necrosis factor (TNF) and TNF receptor pathway. We discussed three models of possible molecular interaction between lytic molecules from effector cytotoxic cells and target-cell membrane to induction of apoptosis. PMID:19254476

  4. Formin’ cellular structures

    PubMed Central

    Bogdan, Sven; Schultz, Jörg; Grosshans, Jörg

    2014-01-01

    Members of the Diaphanous (Dia) protein family are key regulators of fundamental actin driven cellular processes, which are conserved from yeast to humans. Researchers have uncovered diverse physiological roles in cell morphology, cell motility, cell polarity, and cell division, which are involved in shaping cells into tissues and organs. The identification of numerous binding partners led to substantial progress in our understanding of the differential functions of Dia proteins. Genetic approaches and new microscopy techniques allow important new insights into their localization, activity, and molecular principles of regulation. PMID:24719676

  5. Control of cellular automata

    NASA Astrophysics Data System (ADS)

    Bagnoli, Franco; Rechtman, Raúl; El Yacoubi, Samira

    2012-12-01

    We study the problem of master-slave synchronization and control of totalistic cellular automata. The synchronization mechanism is that of setting a fraction of sites of the slave system equal to those of the master one (pinching synchronization). The synchronization observable is the distance between the two configurations. We present three control strategies that exploit local information (the number of nonzero first-order Boolean derivatives) in order to choose the sites to be synchronized. When no local information is used, we speak of simple pinching synchronization. We find the critical properties of control and discuss the best control strategy compared with simple synchronization.

  6. Cellular mechanics and motility

    NASA Astrophysics Data System (ADS)

    Hénon, Sylvie; Sykes, Cécile

    2015-10-01

    The term motility defines the movement of a living organism. One widely known example is the motility of sperm cells, or the one of flagellar bacteria. The propulsive element of such organisms is a cilium(or flagellum) that beats. Although cells in our tissues do not have a flagellum in general, they are still able to move, as we will discover in this chapter. In fact, in both cases of movement, with or without a flagellum, cell motility is due to a dynamic re-arrangement of polymers inside the cell. Let us first have a closer look at the propulsion mechanism in the case of a flagellum or a cilium, which is the best known, but also the simplest, and which will help us to define the hydrodynamic general conditions of cell movement. A flagellum is sustained by cellular polymers arranged in semi-flexible bundles and flagellar beating generates cell displacement. These polymers or filaments are part of the cellular skeleton, or "cytoskeleton", which is, in this case, external to the cellular main body of the organism. In fact, bacteria move in a hydrodynamic regime in which viscosity dominates over inertia. The system is thus in a hydrodynamic regime of low Reynolds number (Box 5.1), which is nearly exclusively the case in all cell movements. Bacteria and their propulsion mode by flagella beating are our unicellular ancestors 3.5 billion years ago. Since then, we have evolved to form pluricellular organisms. However, to keep the ability of displacement, to heal our wounds for example, our cells lost their flagellum, since it was not optimal in a dense cell environment: cells are too close to each other to leave enough space for the flagella to accomplish propulsion. The cytoskeleton thus developed inside the cell body to ensure cell shape changes and movement, and also mechanical strength within a tissue. The cytoskeleton of our cells, like the polymers or filaments that sustain the flagellum, is also composed of semi-flexible filaments arranged in bundles, and also in

  7. Cellular injury evidenced by impedance technology and infrared microspectroscopy

    NASA Astrophysics Data System (ADS)

    le Roux, K.; Prinsloo, L. C.; Meyer, D.

    2015-03-01

    Fourier Transform Infrared (FTIR) spectroscopy is finding increasing biological application, for example in the analysis of diseased tissues and cells, cell cycle studies and investigating the mechanisms of action of anticancer drugs. Cancer treatment studies routinely define the types of cell-drug responses as either total cell destruction by the drug (all cells die), moderate damage (cell deterioration where some cells survive) or reversible cell cycle arrest (cytostasis). In this study the loss of viability and related chemical stress experienced by cells treated with the medicinal plant, Plectranthus ciliatus, was investigated using real time cell electronic sensing (RT-CES) technology and FTIR microspectroscopy. The use of plants as medicines is well established and ethnobotany has proven that crude extracts can serve as treatments against various ailments. The aim of this study was to determine whether FTIR microspectroscopy would successfully distinguish between different types of cellular injury induced by a potentially anticancerous plant extract. Cervical adenocarcinoma (HeLa) cells were treated with a crude extract of Pciliatus and cells monitored using RT-CES to characterize the type of cellular responses induced. Cell populations were then investigated using FTIR microspectroscopy and statistically analysed using One-way Analysis of Variance (ANOVA) and Principal Component Analysis (PCA). The plant extract and a cancer drug control (actinomycin D) induced concentration dependent cellular responses ranging from nontoxic, cytostatic or cytotoxic. Thirteen spectral peaks (915 cm-1, 933 cm-1, 989 cm-1, 1192 cm-1, 1369 cm-1, 1437 cm-1, 1450 cm-1, 1546 cm-1, 1634 cm-1, 1679 cm-1 1772 cm-1, 2874 cm-1 and 2962 cm-1) associated with cytotoxicity were significantly (p value < 0.05, one way ANOVA, Tukey test, Bonferroni) altered, while two of the bands were also indicative of early stress related responses. In PCA, poor separation between nontoxic and cytostatic

  8. Cytotoxic and transforming effects of silica particles with different surface properties in Syrian hamster embryo (SHE) cells.

    PubMed

    Elias, Z; Poirot, O; Danière, M C; Terzetti, F; Marande, A M; Dzwigaj, S; Pezerat, H; Fenoglio, I; Fubini, B

    2000-10-01

    Several crystalline and amorphous silica dusts (two quartz of natural origin, one cristobalite of natural and two of biogenic origin, three amorphous diatomite earths and one pyrogenic amorphous silica) were studied in the SHE cell transformation assay, in order to compare their cytotoxic and transforming potencies and examine the role of the structure and of the state of the surface on these effects. Some samples were modified by grinding, etching and heating with the aim of establishing relationships between single surface properties and biological responses. The results showed that some quartz and cristobalite dusts (crystalline) as well as the diatomaceous earths (amorphous), but not the pyrogenic amorphous silica, were cytotoxic and induced morphological transformation of SHE cells in a concentration-dependent manner. The ranking in cytotoxicity was different from that in transforming potency, suggesting two separate molecular mechanisms for the two effects. The cytotoxic and transforming potencies were different from one dust to another, even among the same structural silicas. The type of crystalline structure (quartz vs cristobalite) and the crystalline vs biogenic amorphous form did not correlate with cytotoxic or transforming potency of silica dusts. Comparison of cellular effects induced by original and surface modified samples revealed that several surface functionalities modulate cytotoxic and transforming potencies. The cytotoxic effects appeared to be related to the distribution and abundance of silanol groups and to the presence of trace amounts of iron on the silica surface. Silica particles with fractured surfaces and/or iron-active sites, able to generate reactive oxygen species, induced SHE cell transformation. The results show that the activity of silica at the cellular level is sensitive to the composition and structure of surface functionalities and confirm that the biological response to silica is a surface originated phenomenon. PMID

  9. Naphthalene metabolism in relation to target tissue anatomy, physiology, cytotoxicity and tumorigenic mechanism of action

    PubMed Central

    Bogen, Kenneth T.; Benson, Janet M.; Yost, Garold S.; Morris, John B.; Dahl, Alan R.; Clewell, Harvey J.; Krishnan, Kannan; Omiecinski, Curtis J.

    2014-01-01

    This report provides a summary of deliberations conducted under the charge for members of Module C Panel participating in the Naphthalene State-of-the-Science Symposium (NS3), Monterey, CA, October 9–12, 2006. The panel was charged with reviewing the current state of knowledge and uncertainty about naphthalene metabolism in relation to anatomy, physiology and cytotoxicity in tissues observed to have elevated tumor incidence in these rodent bioassays. Major conclusions reached concerning scientific claims of high confidence were that: (1) rat nasal tumor occurrence was greatly enhanced, if not enabled, by adjacent, histologically related focal cellular proliferation; (2) elevated incidence of mouse lung tumors occurred at a concentration (30 ppm) cytotoxic to the same lung region at which tumors occurred, but not at a lower and less cytotoxic concentration (tumorigenesis NOAEL = 10 ppm); (3) naphthalene cytotoxicity requires metabolic activation (unmetabolized naphthalene is not a proximate cause of observed toxicity or tumors); (4) there are clear regional and species differences in naphthalene bioactivation; and (5) target tissue anatomy and physiology is sufficiently well understood for rodents, non-human primates and humans to parameterize species-specific physiologically based pharmacokinetic (PBPK) models for nasal and lung effects. Critical areas of uncertainty requiring resolution to enable improved human cancer risk assessment were considered to be that: (1) cytotoxic naphthalene metabolites, their modes of cytotoxic action, and detailed low-dose dose–response need to be clarified, including in primate and human tissues, and neonatal tissues; (2) mouse, rat, and monkey inhalation studies are needed to better define in vivo naphthalene uptake and metabolism in the upper respiratory tract; (3) in vivo validation studies are needed for a PBPK model for monkeys exposed to naphthalene by inhalation, coupled to cytotoxicity studies referred to above; and (4

  10. Pingyangmycin and Bleomycin Share the Same Cytotoxicity Pathway.

    PubMed

    He, Yanli; Lan, Ying; Liu, Yong; Yu, Haibo; Han, Zhangrun; Li, Xiulian; Zhang, Lijuan

    2016-01-01

    Pingyangmycin is an anticancer drug known as bleomycin A5 (A5), discovered in the Pingyang County of Zhejiang Province of China. Bleomycin (BLM) is a mixture of mainly two compounds (A2 and B2), which is on the World Health Organization's list of essential medicines. Both BLM and A5 are hydrophilic molecules that depend on transporters or endocytosis receptors to get inside of cells. Once inside, the anticancer activities rely on their abilities to produce DNA breaks, thus leading to cell death. Interestingly, the half maximal inhibitory concentration (IC50) of BLMs in different cancer cell lines varies from nM to μM ranges. Different cellular uptake, DNA repair rate, and/or increased drug detoxification might be some of the reasons; however, the molecules and signaling pathways responsible for these processes are largely unknown. In the current study, we purified the A2 and B2 from the BLM and tested the cytotoxicities and the molecular mechanisms of each individual compound or in combination with six different cell lines, including a Chinese hamster ovary (CHO) cell line defective in glycosaminoglycan biosynthesis. Our data suggested that glycosaminoglycans might be involved in the cellular uptake of BLMs. Moreover, both BLM and A5 shared similar signaling pathways and are involved in cell cycle and apoptosis in different cancer cell lines. PMID:27376254

  11. Anti-tumour cytotoxicity of poly(A)-containing messenger RNA isolated from tumour-specific immunogenic RNA.

    PubMed

    Greenup, C J; Vallera, D A; Pennline, K J; Kolodziej, B J; Dodd, M C

    1978-07-01

    The transfer of tumour-specific cytotoxicity against a murine fibrosar-coma has been demonstrated in vitro using xenogeneic RNA extracted from tumour-cell-immune animals. Poly(A)-tailed messenger RNA from immunogenic RNA was isolated by passage through an oligo(dT)-cellulose column, and evaluated to determine whether the same tumour-specific cytotoxicity could be transferred. Aliquots of normal C3H mouse lymphocytes were treated with poly(A)-containing immune RNA, whole-cell immune RNA lacking poly(A) and total cellular immune RNA. Treated cells were tested in vitro using an adaptation of the Takasugi and Klein microcytotoxicity assay. Percent cytotoxicity was calculted using cells treated with fractions of normal RNA as control. An increase in tumour cytotoxicity was found with poly(A)-containing immune RNA. The optimum dose of poly(A)-tailed immune RNA was estimated as 6.5 microgram of RNA per 4 x 10(6) lymphocytes. Populations of lymphocytes were separated using glass and nylon wool. T- and B-enriched populations were treated with various RNA components. The adherent cell population showed no significant cytotoxicity, whilst treatment of the nonadherent population with poly(A)-tailed immune RNA produced high levels of cytotoxicity. PMID:687518

  12. Anti-tumour cytotoxicity of poly(A)-containing messenger RNA isolated from tumour-specific immunogenic RNA.

    PubMed Central

    Greenup, C. J.; Vallera, D. A.; Pennline, K. J.; Kolodziej, B. J.; Dodd, M. C.

    1978-01-01

    The transfer of tumour-specific cytotoxicity against a murine fibrosar-coma has been demonstrated in vitro using xenogeneic RNA extracted from tumour-cell-immune animals. Poly(A)-tailed messenger RNA from immunogenic RNA was isolated by passage through an oligo(dT)-cellulose column, and evaluated to determine whether the same tumour-specific cytotoxicity could be transferred. Aliquots of normal C3H mouse lymphocytes were treated with poly(A)-containing immune RNA, whole-cell immune RNA lacking poly(A) and total cellular immune RNA. Treated cells were tested in vitro using an adaptation of the Takasugi and Klein microcytotoxicity assay. Percent cytotoxicity was calculted using cells treated with fractions of normal RNA as control. An increase in tumour cytotoxicity was found with poly(A)-containing immune RNA. The optimum dose of poly(A)-tailed immune RNA was estimated as 6.5 microgram of RNA per 4 x 10(6) lymphocytes. Populations of lymphocytes were separated using glass and nylon wool. T- and B-enriched populations were treated with various RNA components. The adherent cell population showed no significant cytotoxicity, whilst treatment of the nonadherent population with poly(A)-tailed immune RNA produced high levels of cytotoxicity. PMID:687518

  13. Effects of folic acid deficiency and MTHFRC677T polymorphisms on cytotoxicity in human peripheral blood lymphocytes

    SciTech Connect

    Wu Xiayu; Liang Ziqing; Zou Tianning; Wang Xu

    2009-02-13

    Apoptosis (APO) and necrosis (NEC) are two different types of cell death occurring in response to cellular stress factors. Cells with DNA damage may undergo APO or NEC. Folate is an essential micronutrient associated with DNA synthesis, repair and methylation. Methylenetetrahydrofolate reductase (MTHFR) regulates intracellular folate metabolism. Folate deficiency and MTHFR C677T polymorphisms have been shown to be related to DNA damage. To verify the cytotoxic effects of folate deficiency on cells with different MTHFR C677T genotypes, 15 human peripheral lymphocyte cases with different MTHFR C677T genotypes were cultured in folic acid (FA)-deficient and -sufficient media for 9 days. Cytotoxicity was quantified using the frequencies of APO and NEC as endpoints, the nuclear division index (NDI), and the number of viable cells (NVC). These results showed that FA is an important factor in reducing cytotoxicity and increasing cell proliferation. Lymphocytes with the TT genotype proliferated easily under stress and exhibited different responses to FA deficiency than lymphocytes with the CC and CT genotypes. A TT individual may accumulate more cytotoxicity under cytotoxic stress, suggesting that the effects of FA deficiency on cytotoxicity are greater than the effects in individuals with the other MTHFR C677T variants.

  14. Cyclodextrin modulates the cytotoxic effects of chlorhexidine on microrganisms and cells in vitro.

    PubMed

    Teixeira, K I R; Denadai, A M L; Sinisterra, R D; Cortés, M E

    2015-05-01

    Although several studies have shown that chlorhexidine (Cx) has bactericidal activity and exerts toxic effects on periodontal tissues a few studies evaluated mechanisms to reduce its adverse effects maintaining the antimicrobial properties. Therefore, the aim of the present study was to investigate the in vitro antimicrobial activity and cellular cytotoxicity of Cx included on cyclodextrins (Cd), α, β or Hp-β-cyclodextrins (Hp-β-Cd). The influence of Cds was determined by increasing its molar rate 1:1 to 1:4 in relation with free Cx. The minimal inhibitory concentrations (MICs) for Candida albicans, Aggregatibacter actinomycetemcomitans actinomycemcomitans and Streptococcus mutans were determined. An ergosterol solubilization assay was carried out using the C. albicans model and osteoblasts, fibroblasts and tumoral Caco-2 cells for cytotoxicity assay. The antimicrobial activity results in a significant growth inhibition of C. albicans when it was treated with Cx:α-Cd complexes, whereas Cx:β-Cd was more effective for A. actinomycetemcomitans, and Cx:Hp-β-Cd complexes was for S. mutans when compared to the other complexes. The cytotoxicity for fibroblasts and osteoblasts decreased in relation with each kind of Cd been β-Cd ≤ Hp-β-Cd ≤ α-Cd. Although the Hp-β-Cd inclusion complexes had more severe effects on Caco-2 cells, all complexes exhibited less cytotoxicity than free Cx. The α-Cd, β-Cd and Hp-β-Cd increase the antimicrobial activity of Cx, but decrease its cytotoxic effects on mammalian cells. Taken together these findings suggest that cyclodextrins are a tool for modulation of effects of Cx. It could be useful to design Cx/Cd delivery systems with high efficacy and minimum cytotoxic effects. PMID:24491181

  15. Cytotoxicity Induced by Engineered Silver Nanocrystallites is Dependent on Surface Coatings and Cell Types

    SciTech Connect

    Suresh, Anil K; Pelletier, Dale A; Wang, Wei; Morrell-Falvey, Jennifer L; Doktycz, Mitchel John

    2012-01-01

    Due to their unique antimicrobial properties silver nanocrystallites have garnered substantial recognition and are used extensively in biomedical applications such as wound dressing, surgical instruments and as bone substitute material. They are also released into unintended locations such as the environment or biosphere. Therefore it is imperative to understand the potential interactions, fate and transport of nanoparticles with environmental biotic systems. Although numerous factors including the composition, size, shape, surface charge and capping molecule of nanoparticles are known to influence the cell cytotoxicity, our results demonstrate for the first time that surface coatings are a major determinant in eliciting the potential cytotoxicity and cell interactions of silver nanoparticles. In the present investigation, silver nanocrystallites with nearly uniform size and shape distribution but with different surface coatings, imparting overall high negativity to high positivity, were synthesized. These nanoparticles were poly (diallyldimethylammonium) chloride-Ag, biogenic-Ag, colloidal-Ag (uncoated) and oleate-Ag with zeta potentials +45 5 mV, -12 2 mV, -42 5 mV and -45 5 mV respectively; the particles were thoroughly purified so as to avoid false cytotoxicity interpretations. A systematic investigation on the cytotoxic effects, cellular response and membrane damage caused by these four different silver nanoparticles were evaluated using multiple toxicity measurements on mouse macrophage (RAW-264.7) and lung epithelial (C-10) cell lines. From a toxicity perspective, our results clearly indicated that the cytotoxicity was depend on various factors such as synthesis procedure, surface coat or surface charge and the cell-type for the different silver nanoparticles that were investigated. Poly (diallyldimethylammonium) chloride -Ag was found to be the most toxic, followed by biogenic-Ag and oleate-Ag, whereas uncoated-Ag was found to be least toxic to both

  16. A rapid and sensitive fluorometric microassay for determining cell mediated cytotoxicity to adherent growing cell lines.

    PubMed

    Krüger-Krasagakes, S; Garbe, C; Kossman, P; Orfanos, C E

    1992-11-25

    In order to measure cell mediated cytotoxicity to adherent growing cell lines in vitro more rapidly and conveniently, a fluorometric microassay was developed and results were compared with those obtained by the 51Cr release assay. The fluorometric method is based on the hydrolysis of the fluorochrome 4-methylumbelliferyl heptanoate (MUH) by intracellular esterases of viable cells. Melanoma cell monolayers were incubated with lymphokine activated killer (LAK) cells for 4 h at various effector: target (E:T) cell ratios (E:T = 16, 8, 4, 2:1). Thereafter surviving adherent melanoma cells were stained with MUH for 30 min and fluorescence was measured directly in a 96 well plate reader. For the calculation of LAK cell cytotoxicity fluorescence values were corrected for the number of nonspecifically detached tumor cells during the washes and the number of nonspecifically adherent LAK cells. Using identical target and effector cell preparations both assays showed a nearly proportional increase of percentage cytotoxicity with rising numbers of lymphocytes. Compared with the 51Cr release assay, however, higher cytotoxicity values were obtained with the fluorometric MUH microassay: 57% with MUH versus 26% with 51Cr and 39% versus 14% for cell lines StML-11 and SKMel-28, respectively (E:T ratio = 16:1). The higher cytotoxicity rates obtained with the fluorometric MUH microassay were not due to the additional 30 min staining with MUH or due to nonspecific hydrolysis of MUH by extracellular esterases released from damaged cells, as could be shown by a series of experiments. In conclusion, a simple and rapid fluorometric microassay has been developed showing reliable reproducibility and a higher sensitivity compared with the 51Cr release assay for the determination of cellular cytotoxicity to adherent growing cell lines, avoiding hazardous radioactive labels. PMID:1431156

  17. Cellular Contraction and Polarization Drive Collective Cellular Motion.

    PubMed

    Notbohm, Jacob; Banerjee, Shiladitya; Utuje, Kazage J C; Gweon, Bomi; Jang, Hwanseok; Park, Yongdoo; Shin, Jennifer; Butler, James P; Fredberg, Jeffrey J; Marchetti, M Cristina

    2016-06-21

    Coordinated motions of close-packed multicellular systems typically generate cooperative packs, swirls, and clusters. These cooperative motions are driven by active cellular forces, but the physical nature of these forces and how they generate collective cellular motion remain poorly understood. Here, we study forces and motions in a confined epithelial monolayer and make two experimental observations: 1) the direction of local cellular motion deviates systematically from the direction of the local traction exerted by each cell upon its substrate; and 2) oscillating waves of cellular motion arise spontaneously. Based on these observations, we propose a theory that connects forces and motions using two internal state variables, one of which generates an effective cellular polarization, and the other, through contractile forces, an effective cellular inertia. In agreement with theoretical predictions, drugs that inhibit contractility reduce both the cellular effective elastic modulus and the frequency of oscillations. Together, theory and experiment provide evidence suggesting that collective cellular motion is driven by at least two internal variables that serve to sustain waves and to polarize local cellular traction in a direction that deviates systematically from local cellular velocity. PMID:27332131

  18. Integrated cellular systems

    NASA Astrophysics Data System (ADS)

    Harper, Jason C.

    The generation of new three-dimensional (3D) matrices that enable integration of biomolecular components and whole cells into device architectures, without adversely altering their morphology or activity, continues to be an expanding and challenging field of research. This research is driven by the promise that encapsulated biomolecules and cells can significantly impact areas as diverse as biocatalysis, controlled delivery of therapeutics, environmental and industrial process monitoring, early warning of warfare agents, bioelectronics, photonics, smart prosthetics, advanced physiological sensors, portable medical diagnostic devices, and tissue/organ replacement. This work focuses on the development of a fundamental understanding of the biochemical and nanomaterial mechanisms that govern the cell directed assembly and integration process. It was shown that this integration process relies on the ability of cells to actively develop a pH gradient in response to evaporation induced osmotic stress, which catalyzes silica condensation within a thin 3D volume surrounding the cells, creating a functional bio/nano interface. The mechanism responsible for introducing functional foreign membrane-bound proteins via proteoliposome addition to the silica-lipid-cell matrix was also determined. Utilizing this new understanding, 3D cellular immobilization capabilities were extended using sol-gel matrices endowed with glycerol, trehalose, and media components. The effects of these additives, and the metabolic phase of encapsulated S. cerivisiase cells, on long-term viability and the rate of inducible gene expression was studied. This enabled the entrapment of cells within a novel microfluidic platform capable of simultaneous colorimetric, fluorescent, and electrochemical detection of a single analyte, significantly improving confidence in the biosensor output. As a complementary approach, multiphoton protein lithography was utilized to engineer 3D protein matrices in which to

  19. The cytotoxicity study of praziquantel enantiomers

    PubMed Central

    Sun, Qian; Mao, Ruifeng; Wang, Dongling; Hu, Changyan; Zheng, Yang; Sun, Dequn

    2016-01-01

    Praziquantel (PZQ) is prescribed as a racemic mixture (racemic-PZQ, rac-PZQ), which is composed of (R)-PZQ and (S)-PZQ. In this work, the cytotoxicity of rac-PZQ and its two enantiomers (R)-PZQ and (S)-PZQ on eight cell lines (L-02, HepG2, prf-plc-5, SH-SY5Y, HUVEC, A549, HCT-15, Raw264.7) was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphe-nyltetrazolium bromide and lactate dehydrogenase assays. The morphology of apoptotic cells was studied by fluorescence microscope using Hoechst 33342 staining, and the cytotoxicity of the compounds was also tested by lactate dehydrogenase assay. Results revealed that (R)-PZQ had negligible cytotoxicity against L-02, SH-SY5Y, HUVEC, A549, HCT-15, and Raw264.7 cells but selectively inhibited tumor cell lines (prf-plc-5 and HepG2). However, in contrast to (R)-PZQ, the (S)-isomer showed higher cytotoxicity against L-02 cells and lower inhibition on prf-plc-5 and HepG2 cells. Besides, (R)-PZQ showed lower cytotoxicity on SH-SY5Y cells than (S)-PZQ. Meanwhile, (R)-PZQ at <80 μM concentration could promote proliferation of macrophage cells (Raw264.7). Our research revealed that (R)-PZQ has lower cytotoxicity than (S)-PZQ and has similar cytotoxicity with rac-PZQ. (S)-PZQ is the principal enantiomer to cause side effects on human definitive hosts. These findings gave the reasonable reasons for World Health Organization to produce (R)-PZQ as a replacement for rac-PZQ for the treatment of schistosomiasis. PMID:27445457

  20. The cytotoxicity study of praziquantel enantiomers.

    PubMed

    Sun, Qian; Mao, Ruifeng; Wang, Dongling; Hu, Changyan; Zheng, Yang; Sun, Dequn

    2016-01-01

    Praziquantel (PZQ) is prescribed as a racemic mixture (racemic-PZQ, rac-PZQ), which is composed of (R)-PZQ and (S)-PZQ. In this work, the cytotoxicity of rac-PZQ and its two enantiomers (R)-PZQ and (S)-PZQ on eight cell lines (L-02, HepG2, prf-plc-5, SH-SY5Y, HUVEC, A549, HCT-15, Raw264.7) was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphe-nyltetrazolium bromide and lactate dehydrogenase assays. The morphology of apoptotic cells was studied by fluorescence microscope using Hoechst 33342 staining, and the cytotoxicity of the compounds was also tested by lactate dehydrogenase assay. Results revealed that (R)-PZQ had negligible cytotoxicity against L-02, SH-SY5Y, HUVEC, A549, HCT-15, and Raw264.7 cells but selectively inhibited tumor cell lines (prf-plc-5 and HepG2). However, in contrast to (R)-PZQ, the (S)-isomer showed higher cytotoxicity against L-02 cells and lower inhibition on prf-plc-5 and HepG2 cells. Besides, (R)-PZQ showed lower cytotoxicity on SH-SY5Y cells than (S)-PZQ. Meanwhile, (R)-PZQ at <80 μM concentration could promote proliferation of macrophage cells (Raw264.7). Our research revealed that (R)-PZQ has lower cytotoxicity than (S)-PZQ and has similar cytotoxicity with rac-PZQ. (S)-PZQ is the principal enantiomer to cause side effects on human definitive hosts. These findings gave the reasonable reasons for World Health Organization to produce (R)-PZQ as a replacement for rac-PZQ for the treatment of schistosomiasis. PMID:27445457

  1. Engineering Cellular Metabolism.

    PubMed

    Nielsen, Jens; Keasling, Jay D

    2016-03-10

    Metabolic engineering is the science of rewiring the metabolism of cells to enhance production of native metabolites or to endow cells with the ability to produce new products. The potential applications of such efforts are wide ranging, including the generation of fuels, chemicals, foods, feeds, and pharmaceuticals. However, making cells into efficient factories is challenging because cells have evolved robust metabolic networks with hard-wired, tightly regulated lines of communication between molecular pathways that resist efforts to divert resources. Here, we will review the current status and challenges of metabolic engineering and will discuss how new technologies can enable metabolic engineering to be scaled up to the industrial level, either by cutting off the lines of control for endogenous metabolism or by infiltrating the system with disruptive, heterologous pathways that overcome cellular regulation. PMID:26967285

  2. Cellular Morphogenesis In Silico

    PubMed Central

    Shinbrot, Troy; Chun, Young; Caicedo-Carvajal, Carlos; Foty, Ramsey

    2009-01-01

    Abstract We describe a model that simulates spherical cells of different types that can migrate and interact either attractively or repulsively. We find that both expected morphologies and previously unreported patterns spontaneously self-assemble. Among the newly discovered patterns are a segmented state of alternating discs, and a “shish-kebab” state, in which one cell type forms a ring around a second type. We show that these unique states result from cellular attraction that increases with distance (e.g., as membranes stretch viscoelastically), and would not be seen in traditional, e.g., molecular, potentials that diminish with distance. Most of the states found computationally have been observed in vitro, and it remains to be established what role these self-assembled states may play in in vivo morphogenesis. PMID:19686642

  3. Cytotoxicity evaluation of a copaiba oil-based root canal sealer compared to three commonly used sealers in endodontics

    PubMed Central

    Garrido, Angela Delfina Bittencourt; de Cara, Sueli Patricia Harumi Miyagi; Marques, Marcia Martins; Sponchiado, Emílio Carlos; Garcia, Lucas da Fonseca Roberti; de Sousa-Neto, Manoel Damião

    2015-01-01

    Background: The constant development of new root canal sealers has allowed the solution of a large number of clinical cases in endodontics, however, cytotoxicity of such sealers must be tested before their validation as filling materials. The aim of this study was to evaluate the cytotoxic effect of a new Copaiba oil-based root canal sealer (Biosealer [BS]) on osteoblast-like Osteo-1 cells. Materials and Methods: The experimental groups were formed according to the culture medium conditioned with the tested sealers, as follows: Control group (CG) (culture medium without conditioning); Sealer 26 (S26) - culture medium + S26; Endofill (EF) - culture medium + EF; AH Plus (AHP) - culture medium + AHP; and BS - culture medium + BS (Copaiba oil-based sealer). The conditioned culture medium was placed in contact with 2 × 104 cells cultivated on 60 mm diameter Petri dishes for 24 h. Then, hemocytometer count was performed to evaluate cellular viability, using Trypan Blue assay. The normal distribution of data was tested by the Kolmogorov-Smirnov test and the values obtained for cellular viability were statistically analyzed (1-way ANOVA, Tukey's test - P < 0.05), with a significance level of 5%. Results: S26, EF and AHP presented decreased cellular viability considerably, with statistical significance compared with CG (P < 0.05). BS maintained cellular viability similar to CG (P > 0.05). Conclusion: The Copaiba oil-based root canal sealer presented promising results in terms of cytotoxicity which indicated its usefulness as a root canal sealer. PMID:25878676

  4. Nanosecond pulsed electric field (nsPEF) enhance cytotoxicity of cisplatin to hepatocellular cells by microdomain disruption on plasma membrane.

    PubMed

    Yin, Shengyong; Chen, Xinhua; Xie, Haiyang; Zhou, Lin; Guo, Danjing; Xu, Yuning; Wu, Liming; Zheng, Shusen

    2016-08-15

    Previous studies showed nanosecond pulsed electric field (nsPEF) can ablate solid tumors including hepatocellular carcinoma (HCC) but its effect on cell membrane is not fully understood. We hypothesized nsPEF disrupt the microdomains on outer-cellular membrane with direct mechanical force and as a result the plasma membrane permeability increases to facilitate the small molecule intake. Three HCC cells were pulsed one pulse per minute, an interval longer than nanopore resealing time. The cationized ferritin was used to mark up the electronegative microdomains, propidium iodide (PI) for membrane permeabilization, energy dispersive X-ray spectroscopy (EDS) for the negative cell surface charge and cisplatin for inner-cellular cytotoxicity. We demonstrated that the ferritin marked-microdomain and negative cell surface charge were disrupted by nsPEF caused-mechanical force. The cell uptake of propidium and cytotoxicity of DNA-targeted cisplatin increased with a dose effect. Cisplatin gains its maximum inner-cellular cytotoxicity when combining with nsPEF stimulation. We conclude that nsPEF disrupt the microdomains on the outer cellular membrane directly and increase the membrane permeabilization for PI and cisplatin. The microdomain disruption and membrane infiltration changes are caused by the mechanical force from the changes of negative cell surface charge. PMID:27375200

  5. Immunotherapy against HPV16/18 generates potent TH1 and cytotoxic cellular immune responses.

    PubMed

    Bagarazzi, Mark L; Yan, Jian; Morrow, Matthew P; Shen, Xuefei; Parker, R Lamar; Lee, Jessica C; Giffear, Mary; Pankhong, Panyupa; Khan, Amir S; Broderick, Kate E; Knott, Christine; Lin, Feng; Boyer, Jean D; Draghia-Akli, Ruxandra; White, C Jo; Kim, J Joseph; Weiner, David B; Sardesai, Niranjan Y

    2012-10-10

    Despite the development of highly effective prophylactic vaccines against human papillomavirus (HPV) serotypes 16 and 18, prevention of cervical dysplasia and cancer in women infected with high-risk HPV serotypes remains an unmet medical need. We report encouraging phase 1 safety, tolerability, and immunogenicity results for a therapeutic HPV16/18 candidate vaccine, VGX-3100, delivered by in vivo electroporation (EP). Eighteen women previously treated for cervical intraepithelial neoplasia grade 2 or 3 (CIN2/3) received a three-dose (intramuscular) regimen of highly engineered plasmid DNA encoding HPV16 and HPV18 E6/E7 antigens followed by EP in a dose escalation study (0.3, 1, and 3 mg per plasmid). Immunization was well tolerated with reports of mild injection site reactions and no study-related serious or grade 3 and 4 adverse events. No dose-limiting toxicity was noted, and pain was assessed by visual analog scale, with average scores decreasing from 6.2/10 to 1.4 within 10 min. Average peak interferon-γ enzyme-linked immunospot magnitudes were highest in the 3 mg cohort in comparison to the 0.3 and 1 mg cohorts, suggesting a trend toward a dose effect. Flow cytometric analysis revealed the induction of HPV-specific CD8(+) T cells that efficiently loaded granzyme B and perforin and exhibited full cytolytic functionality in all cohorts. These data indicate that VGX-3100 is capable of driving robust immune responses to antigens from high-risk HPV serotypes and could contribute to elimination of HPV-infected cells and subsequent regression of the dysplastic process. PMID:23052295

  6. Effects of ethanolamine and choline on thiotepa cellular accumulation and cytotoxicity in L1210 cells

    SciTech Connect

    Egorin, M.J.; Snyder, S.W.; Wietharn, B.E. )

    1990-07-15

    The amino alcohols, ethanolamine and choline, were studied for their effects on (a) L1210 cell growth, (b) N,N{prime},N{double prime}-triethylenetheiphosphoramide (thiotepa)-induced growth inhibition of L1210 cells, and (c) 14C accumulation by L1210 cells incubated with (14C)thiotepa. Ethanolamine, at concentrations up to 300 microM, had no effect on L1210 cell growth but, at concentrations greater than 300 microM, produced a dose-dependent reduction in cell growth. Choline, at concentrations up to 20 mM, had no effect on L1210 cell growth. Neither ethanolamine, at 250 microM, nor choline, at 10 mM, altered the ability of thiotepa to reduce L1210 cell growth. Neither ethanolamine, at 250 microM, nor choline, at 10 mM, affected the rapid phase of 14C accumulation by L1210 cells incubated with (14C)thiotepa. The slow phase of 14C accumulation by L1210 cells incubated with 5 microM (14C)thiotepa, a process which is 80-85% due to production of (14C)phosphatidylethanolamine, was not affected by 250 microM choline. In contrast, ethanolamine produced a dose-dependent reduction in this slow rate of 14C accumulation. The reduction in the slow rate of 14C accumulation produced by ethanolamine was due almost entirely to a decrease in the accumulation of nonexchangeable 14C. Kinetic analysis of the inhibition of 14C accumulation produced by 25, 100, and 250 microM ethanolamine was compatible with competitive inhibition. Thin layer chromatography of cell extracts showed that the ability of ethanolamine to reduce 14C accumulation by L1210 cells incubated with (14C)thiotepa was due solely to reduction in production of (14C)phosphatidylethanolamine. These results are all compatible with and predicted by our previously described scheme wherein thiotepa enters cells by simple diffusion and serves as a prodrug for aziridine.

  7. Paclitaxel molecularly imprinted polymer-PEG-folate nanoparticles for targeting anticancer delivery: Characterization and cellular cytotoxicity.

    PubMed

    Esfandyari-Manesh, Mehdi; Darvishi, Behrad; Ishkuh, Fatemeh Azizi; Shahmoradi, Elnaz; Mohammadi, Ali; Javanbakht, Mehran; Dinarvand, Rassoul; Atyabi, Fatemeh

    2016-05-01

    The aim of this work was to synthesize molecularly imprinted polymer-poly ethylene glycol-folic acid (MIP-PEG-FA) nanoparticles for use as a controlled release carrier for targeting delivery of paclitaxel (PTX) to cancer cells. MIP nanoparticles were synthesized by a mini-emulsion polymerization technique and then PEG-FA was conjugated to the surface of nanoparticles. Nanoparticles showed high drug loading and encapsulation efficiency, 15.6 ± 0.8 and 100%, respectively. The imprinting efficiency of MIPs was evaluated by binding experiments in human serum. Good selective binding and recognition were found in MIP nanoparticles. In vitro drug release studies showed that MIP-PEG-FA have a controlled release of PTX, because of the presence of imprinted sites in the polymeric structure, which makes it is suitable for sustained drug delivery. The drug release from polymeric nanoparticles was indeed higher at acidic pH. The molecular structure of MIP-PEG-FA was confirmed by Hydrogen-Nuclear Magnetic Resonance (H NMR), Fourier Transform InfraRed (FT-IR), and Attenuated Total Reflection (ATR) spectroscopy, and their thermal behaviors by Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). Scanning Electron Microscopy (SEM) and Photon Correlation Spectroscopy (PCS) results showed that nanoparticles have a smooth surface and spherical shape with an average size of 181 nm. MIP-PEG-FA nanoparticles showed a greater amount of intracellular uptake in folate receptor-positive cancer cells (MDA-MB-231 cells) in comparison with the non-folate nanoparticles and free PTX, with half maximal inhibitory concentrations (IC50) of 4.9 ± 0.9, 7.4 ± 0.5 and 32.8 ± 3.8 nM, respectively. These results suggest that MIP-PEG-FA nanoparticles could be a potentially useful drug carrier for targeting drug delivery to cancer cells. PMID:26952466

  8. Synthesis, antiviral activity, cytotoxicity and cellular pharmacology of l-3'-azido-2',3'-dideoxypurine nucleosides.

    PubMed

    Zhang, Hong-Wang; Detorio, Mervi; Herman, Brian D; Solomon, Sarah; Bassit, Leda; Nettles, James H; Obikhod, Aleksandr; Tao, Si-Jia; Mellors, John W; Sluis-Cremer, Nicolas; Coats, Steven J; Schinazi, Raymond F

    2011-09-01

    Microwave-assisted optimized transglycosylation reactions were used to prepare eleven modified l-3'-azido-2',3'-dideoxypurine nucleosides. These l-nucleoside analogs were evaluated against HIV and hepatitis B virus. The l-3'-azido-2',3'-dideoxypurines nucleosides were metabolized to nucleoside 5'-triphosphates in primary human lymphocytes, but exhibited weak or no antiviral activity against HIV-1. The nucleosides were also inactive against HBV in HepG2 cells. Pre-steady state kinetic experiments demonstrated that the l-3'-azido-2',3'-dideoxypurine triphosphates could be incorporated by purified HIV-1 reverse transcriptase, although their catalytic efficiency (k(pol)/K(d)) of incorporation was low. Interestingly, a phosphoramidate prodrug of l-3'-azido-2',3'-dideoxyadenosine exhibited anti-HIV-1 activity without significant toxicity. PMID:21700368

  9. Bispecific antibodies and retargeted cellular cytotoxicity: novel approaches to cancer therapy.

    PubMed

    Wunderlich, J R; Mezzanzanica, D; Garrido, M A; Neblock, D S; Daddona, P E; Andrew, S M; Zurawski, V R; Canevari, S; Colnaghi, M I; Segal, D M

    1992-01-01

    We have used a relatively new technology to increase the number of human lymphocytes that will react with human ovarian carcinoma cells. This technology, often called "retargeting of the immune system," can temporarily redirect the activity of immune cells that were originally committed to react with foreign substances other than cancer cells. In the example presented here, the antitumor effects of retargeted human T lymphocytes, collected from normal donors, were tested in immunodeficient mice with a human ovarian carcinoma line growing intraperitoneally. We retargeted T cells in vitro with a bispecific antibody that reacted with the T cell receptor complex and with a cell-surface antigen expressed by the ovarian carcinoma cells. Retargeted lymphocytes, injected intraperitoneally into mice 4 days after intraperitoneal injection of the tumor cells, impeded tumor growth and doubled the host survival time. These findings provide support for the concept that treatment of ovarian cancer patients with retargeted T cells could prove beneficial. PMID:1633315

  10. Cytotoxicity and morphological effects induced by carvacrol and thymol on the human cell line Caco-2.

    PubMed

    Llana-Ruiz-Cabello, María; Gutiérrez-Praena, Daniel; Pichardo, Silvia; Moreno, F Javier; Bermúdez, José María; Aucejo, Susana; Cameán, Ana María

    2014-02-01

    Essential oils used as additives in the food industry due to its flavour, antimicrobial and antioxidant properties. Therefore, human can be exposed orally to these compounds through the ingestion of foods. In this sense, the present work aims to assess toxicological effects of oregano essential oil on the digestive tract. In concrete, the cytotoxic effects of two components of the oregano essential oils, carvacrol and thymol, and their mixture, on the intestinal cells line Caco-2 after 24 and 48 h of exposure are studied. The basal cytotoxicity endpoints assayed (total protein content, neutral red uptake and the tetrazolium salt reduction) and the annexin/propidium iodide staining indicated that carvacrol and the mixture carvacrol/thymol induced toxic effects. Moreover, a morphological study was performed in order to determine the ultrastructural cellular damages caused by these substances. The main morphological alterations were vacuolated cytoplasm, altered organelles and finally cell death. In addition, although no cytotoxic effects were recorded for thymol at any concentration and time of exposure, ultrastructural changes evidenced cellular damage such as lipid degeneration, mitochondrial damage, nucleolar segregation and apoptosis. PMID:24326232

  11. Cytotoxic activity of a synthetic deoxypodophyllotoxin derivative with an opened D-ring.

    PubMed

    Chen, Chuan; Wang, Cui-Cui; Wang, Zhong; Geng, Wen-Yue; Xu, Hui; Song, Xiao-Mei; Luo, Du-Qiang

    2016-05-01

    Podophyllotoxin and its synthetic derivatives are valuable medicinal agents that have antitumor, insecticidal, and antifungal properties. We previously synthesized a deoxypodophyllotoxin derivative with an opened D-ring (DPD) exhibiting potent insecticidal activity. This article was firstly performed to identify the cytotoxicity of DPD toward human cancer cell lines (SGC7901, HeLa, and A549) and normal cell line (HEK293T) using MTT assay. DPD showed potent cytotoxicity against human cancer lines (HeLa and A549) and less cytotoxicity against normal cell lines HEK293T. DPD could also induce the cell cycle arrest at G2/M phase in HeLa cells and significantly increase the phosphorylation (Tyr 15) of CDC2 leading to inactivation of CDC2. The effects of DPD on cellular microtubule networks were detected using immunofluorescence technique in HeLa cells. The immunofluorescence results showed DPD influenced the arrangement and organization of cellular microtubule networks in HeLa cells. Microtubules are long, hollow cylinders made up of polymerized tubulin dimers. Total microtubules were separated after DPD treatment. Western blot results showed that the free polymerized tubulin dimers were obviously increased after DPD treatment. DPD may be a good drug candidate with the therapeutic potential to human cancer by affecting microtubule polymerization. PMID:27123550

  12. Overview of molecular, cellular, and genetic neurotoxicology.

    PubMed

    Wallace, David R

    2005-05-01

    /toxin combinations is they can be detected and measured shortly following exposure and before overt neuroanatomic damage or lesions. Intervention at this point, shortly following exposure, may prevent or at least attenuate further damage to the individual. The use of peripheral biomarkers to assess toxin damage in the CNS has numerous advantages: time-course analysis may be performed, ethical concerns with the use of human subjects can partially be avoided, procedures to acquire samples are less invasive, and in general, peripheral studies are easier to perform. Genetic neurotoxicology comprises two focuses--toxin-induced alterations in genetic expression and genetic alterations that affect toxin metabolism, distribution, and clearance. These differences can be beneficial or toxic. Polymorphisms have been shown to result in altered metabolism of certain toxins (paraoxonase and paraoxon). Conversely, it is possible that some polymorphisms may be beneficial and help prevent the formation of a toxic by-product of an exogenous agent (resistance to ozone-induced lung inflammation). It has also become clear that interactions of potential toxins are not straightforward as interactions with DNA, causing mutations. There are numerous agents that cause epigenetic responses (cellular alterations that are not mutagenic or cytotoxic). This finding suggests that many agents that may originally have been thought of as nontoxic should be re-examined for potential "indirect" toxicity. With the advancement of the human genome project and the development of a human genome map, the effects of potential toxins on single or multiple genes can be identified. Although collectively, the field of neurotoxicology has recently come a long way, it still has a long way to go reach its full potential. As technology and methodology advances continue and cooperation with other disciplines such as neuroscience, biochemistry, neurophysiology, and molecular biology is improved, the mechanisms of toxin action will be

  13. Cytotoxic and genotoxic effects of abamectin, chlorfenapyr, and imidacloprid on CHOK1 cells.

    PubMed

    Al-Sarar, Ali S; Abobakr, Yasser; Bayoumi, Alaa E; Hussein, Hamdy I

    2015-11-01

    The cytotoxicity and genotoxicity of abamectin, chlorfenapyr, and imidacloprid have been evaluated on the Chinese hamster ovary (CHOK1) cells. Neutral red incorporation (NRI), total cellular protein content (TCP), and methyl tetrazolium (MTT) assays were followed to estimate the mid-point cytotoxicity values, NRI50, TCP50, and MTT50, respectively. The effects of the sublethal concentration (NRI25) on glutathione S-transferase (GST), glutathione reductase (GRD), glutathione peroxidase (GPX), and total glutathione content have been evaluated in the presence and absence of reduced glutathione (GSH), vitamin C, and vitamin E. The genotoxicity was evaluated using chromosomal aberrations (CA), micronucleus (MN) formation, and DNA fragmentation techniques in the presence and absence of the metabolic activation system, S9 mix. Abamectin was the most cytotoxic pesticide followed by chlorfenapyr, while imidacloprid was the least cytotoxic one. The glutathione redox cycle components were altered by the tested pesticides in the absence and presence of the tested antioxidants. The results of genotoxicity indicate that abamectin, chlorfenapyr, and imidacloprid have potential genotoxic effects on CHOK1 cells under the experimental conditions. PMID:26122579

  14. Artifacts by marker enzyme adsorption on nanomaterials in cytotoxicity assays with tissue cultures

    NASA Astrophysics Data System (ADS)

    Wohlleben, Wendel; Kolle, Susanne N.; Hasenkamp, Laura-Carolin; Böser, Alexander; Vogel, Sandra; von Vacano, Bernhard; van Ravenzwaay, Ben; Landsiedel, Robert

    2011-07-01

    We used precision cut lung slices (PCLS) to study the cytotoxicity of cobalt ferrite nanomaterials with and without bovine serum albumin (BSA) stabilization. Using mitochondrial activity as an indicator of cytotoxicity (WST-1 assay) increasing concentrations of cobalt ferrite nanomaterial caused increasing levels of cytotoxicity in PCLS irrespective of BSA stabilization. However, there was no increase in released lactate dehydrogenase (LDH) levels caused by BSA stabilized nanomaterial indicating concentration depended cytotoxictiy. Moreover, non-stabilized nanomaterial caused a decrease of background LDH levels in the PCLS culture supernatant confirmed by complementary methods. Direct characterization of the protein corona of extracted nanomaterial shows that the LDH decrease is due to adsorption of LDH onto the surface of the non-stabilized nanomaterial, correlated with strong agglomeration. Preincubation with serum protein blocks the adsorption of LDH and stabilizes the nanomaterial at low agglomeration. We have thus demonstrated the cytotoxicity of nanomaterials in PCLS does not correlate with disrupted membrane integrity followed by LDH release. Furthermore, we found that intracellular enzymes such as the marker enzyme LDH are able to bind onto surfaces of nanomaterial and thereby adulterate the detection of toxic effects. A replacement of BSA by LDH or a secondary LDH-on-BSA-corona were not observed, confirming earlier indications that the protein corona exchange rate are slow or vanishing on inorganic nanomaterial. Thus, the method(s) to assess nanomaterial-mediated effects have to be carefully chosen based on the cellular effect and possible nano-specific artifacts.

  15. HDAC6 regulates the dynamics of lytic granules in cytotoxic T lymphocytes.

    PubMed

    Núñez-Andrade, Norman; Iborra, Salvador; Trullo, Antonio; Moreno-Gonzalo, Olga; Calvo, Enrique; Catalán, Elena; Menasche, Gaël; Sancho, David; Vázquez, Jesús; Yao, Tso-Pang; Martín-Cófreces, Noa Beatriz; Sánchez-Madrid, Francisco

    2016-04-01

    HDAC6 is a tubulin deacetylase involved in many cellular functions related to cytoskeleton dynamics, including cell migration and autophagy. In addition, HDAC6 affects antigen-dependent CD4(+)T cell activation. In this study, we show that HDAC6 contributes to the cytotoxic function of CD8(+)T cells. Immunization studies revealed defective cytotoxic activityin vivoin the absence of HDAC6. Adoptive transfer of wild-type orHdac6(-/-)CD8(+)T cells toRag1(-/-)mice demonstrated specific impairment in CD8(+)T cell responses against vaccinia infection. Mechanistically, HDAC6-deficient cytotoxic T lymphocytes (CTLs) showed defectivein vitrocytolytic activity related to altered dynamics of lytic granules, inhibited kinesin-1-dynactin-mediated terminal transport of lytic granules to the immune synapse and deficient exocytosis, but not to target cell recognition, T cell receptor (TCR) activation or interferon (IFN)γ production. Our results establish HDAC6 as an effector of the immune cytotoxic response that acts by affecting the dynamics, transport and secretion of lytic granules by CTLs. PMID:26869226

  16. Novel optical approaches for label-free quantification of nano-cytotoxic effects

    NASA Astrophysics Data System (ADS)

    Mues, Sarah; Antunovic, Jan; Ketelhut, Steffi; Kemper, Björn; Schnekenburger, Jürgen

    2016-03-01

    Commonly used cytotoxicity assays to determine the formation of reactive oxygen species, cell viability or cell death are often affected by applied nanomaterials, which lead to false-positive or false-negative results. Thus, novel nanomaterial toxicity testing strategies that allow for high nanomaterial doses to determine Low Effect Levels (LOEL) even of low toxic materials are of high interest. We demonstrate novel approaches to quantify cytotoxic effects with new parameter sets such as cellular refractive index, volume, density and dry mass that are obtained by digital holographic microscopy (DHM). Furthermore, we correlate results obtained from spherical (NM 300) and rod shaped (NM 302) silver nanomaterials with established cell viability and cell death assays. Moreover, in a label-free flow cytometry configuration, cell-nanoparticle-interaction-kinetics were determined by side scatter signal analysis. We demonstrate that silver spheres show a higher cytotoxicity than silver rods and found that this effect correlates with a decrease of the intracellular refractive index and a decreased temporal development of dry mass and cell covered surface area indicating reduced cell viability and increased cell death. Results from side scatter analysis suggest a dose-dependent uptake kinetics of both materials that correlates with cytotoxicity data of the established assays. Taken together, our results demonstrate DHM and flow cytometry as promising novel label-free tools for nanomaterial toxicity and cell particle interaction studies.

  17. Dendrimer-curcumin conjugate: a water soluble and effective cytotoxic agent against breast cancer cell lines.

    PubMed

    Debnath, Shawon; Saloum, Darin; Dolai, Sukanta; Sun, Chong; Averick, Saadyah; Raja, Krishnaswami; Fata, Jimmie E

    2013-12-01

    Curcumin, which is derived from the plant Curcuma longa, has received considerable attention as a possible anti-cancer agent. In cell culture, curcumin is capable of inducing apoptosis in cancer cells at concentrations that do not affect normal cells. One draw-back holding curcumin back from being an effective anti-cancer agent in humans is that it is almost completely insoluble in water and therefore has poor absorption and subsequently poor bioavailability. Here we have generated a number of curcumin derivatives (tetrahydro-curcumin, curcumin mono-carboxylic acid, curcumin mono-galactose, curcumin mono-alkyne and dendrimer-curcumin conjugate) to test whether any of them display both cytotoxicity and water solubility. Of those tested only dendrimer-curcumin conjugate exhibited both water solubility and cytotoxicity against SKBr3 and BT549 breast cancer cells. When compared to curcumin dissolved in DMSO, dendrimer-curcumin conjugate dissolved in water was significantly more effective in inducing cytotoxicity, as measured by the MTT assay and effectively induced cellular apoptosis measured by caspase-3 activation. Since dendrimer-curcumin conjugate is water soluble and capable of inducing potent cytotoxic effects on breast cancer cell lines, it may prove to be an effective anti-cancer therapy to be used in humans. PMID:23387971

  18. Safe handling of cytotoxics: guideline recommendations

    PubMed Central

    Easty, A.C.; Coakley, N.; Cheng, R.; Cividino, M.; Savage, P.; Tozer, R.; White, R.E.

    2015-01-01

    Background This evidence-based practice guideline was developed to update and address new issues in the handling of cytotoxics, including the use of oral cytotoxics; the selection and use of personal protective equipment; and treatment in diverse settings, including the home setting. Methods The guideline was developed primarily from an adaptation and endorsement of an existing guideline and from three systematic reviews. Before publication, the guideline underwent a series of peer and external reviews to gather feedback. All comments were addressed, and the guideline was amended when required. The guideline applies to health care workers who could come into contact with cytotoxic drugs at any point in the medication circuit. The intended users are hospital administrators, educators, and managers; occupational health and safety services; and pharmacy and health care workers. Results The recommendations represent a reasonable and practical set of procedures that the intended users of this guideline should implement to minimize opportunities for accidental exposure. They are not limited to just the point of care; they cover the entire chain of cytotoxics handling from the time such agents enter the institution until they leave in the patient or as waste. Conclusions Reducing the likelihood of accidental exposure to cytotoxic agents within the medication circuit is the main objective of this evidenced-based guideline. The recommendations differ slightly from earlier guidelines because of the availability of new evidence. PMID:25684994

  19. Isoflavanones from Desmodium oxyphyllum and their cytotoxicity.

    PubMed

    Li, Yan-Ping; Li, Yin-Ke; Du, Gang; Yang, Hai-Yin; Gao, Xue-Mei; Hu, Qiu-Fen

    2014-01-01

    Two new isoflavanones, (3R)-7-hydroxy-4'-methoxy-5-methoxycarbonyl-isoflavanone (1) and (3R)-8-hydroxy-4'-methoxy-7-methoxycarbonyl-isoflavanone (2), together with seven known isoflavanones (3-9) were isolated from Desmodium oxyphyllum of the Leguminosae family. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compound 1 showed good cytotoxicity against NB4 and SHSY5Y cell lines with IC50 values of 3.1 and 2.5 μM; compound 2 exhibited cytotoxicity against PC3 cell lines with a IC50 value of 3.6 μM; compound 4 showed cytotoxicity against A549 and SHSY5Y cell lines with IC50 values of 3.6 and 2.8 μM; and compound 5 displayed cytotoxicity against NB4, SHSY5Y, and MCF7 cell lines with IC50 values of 2.6, 3.8, and 2.8 μM, respectively. Other compounds also showed moderate cytotoxicity for some tested cell lines with IC50 values between 5.4 and 8.8 μM. PMID:24749537

  20. Investigation of cellular responses upon interaction with silver nanoparticles

    PubMed Central

    Subbiah, Ramesh; Jeon, Seong Beom; Park, Kwideok; Ahn, Sang Jung; Yun, Kyusik

    2015-01-01

    In order for nanoparticles (NPs) to be applied in the biomedical field, a thorough investigation of their interactions with biological systems is required. Although this is a growing area of research, there is a paucity of comprehensive data in cell-based studies. To address this, we analyzed the physicomechanical responses of human alveolar epithelial cells (A549), mouse fibroblasts (NIH3T3), and human bone marrow stromal cells (HS-5), following their interaction with silver nanoparticles (AgNPs). When compared with kanamycin, AgNPs exhibited moderate antibacterial activity. Cell viability ranged from ≤80% at a high AgNPs dose (40 µg/mL) to >95% at a low dose (10 µg/mL). We also used atomic force microscopy-coupled force spectroscopy to evaluate the biophysical and biomechanical properties of cells. This revealed that AgNPs treatment increased the surface roughness (P<0.001) and stiffness (P<0.001) of cells. Certain cellular changes are likely due to interaction of the AgNPs with the cell surface. The degree to which cellular morphology was altered directly proportional to the level of AgNP-induced cytotoxicity. Together, these data suggest that atomic force microscopy can be used as a potential tool to develop a biomechanics-based biomarker for the evaluation of NP-dependent cytotoxicity and cytopathology. PMID:26346562

  1. Antioxidant Cerium Oxide Nanoparticle Hydrogels for Cellular Encapsulation

    PubMed Central

    Weaver, Jessica D; Stabler, Cherie L

    2015-01-01

    Oxidative stress and the resulting radical by-products cause significant toxicity and graft loss in cellular transplantation. Here, the engineering of an auto-catalytic, antioxidant, self-renewing cerium oxide nanoparticle (CONP)-composite hydrogel is reported. This enzyme-mimetic material ubiquitously scavenges ambient free radicals, with the potential to provide indefinite antioxidant protection. Here, we evaluated the potential of this system to enhance the protection of encapsulated beta cells. Co-incubation of CONPs, free in solution with beta cells, demonstrated potent cytoprotection from superoxide exposure; however, phagocytosis of the CONPs by the beta cells resulted in cytotoxicity at concentrations as low as 1 mM. When CONPs were embedded within alginate hydrogels, the composite hydrogel provided cytoprotection to encapsulated beta cells from free radical attack without cytotoxicity, even up to 10 mM concentrations. This nanocomposite hydrogel has wide applicability in cellular transplantation, with the unique advantage of localization of these potent antioxidant CONPs and their capacity for sustained, long-term scavenging. PMID:25620795

  2. [Synthesis and cytotoxicity of allobetulin derivatives].

    PubMed

    Kazakova, O B; Smirnova, I E; Khusnutdinova, E F; Zhukova, O S; Fetisova, L V; Apryshko, G N; Medvedeva, N I; Iamansarov, E Iu; Baĭkova, I P; Nguen, Thanh Tra; Thu, Do Thi H

    2014-01-01

    The synthesis and screening of antitumor activity in vitro (cytotoxicity) of various oxygen, nitrogen, sulfur and platinum-containing derivatives of allobetulin, including different arrangements of the double bonds in the A and B rings, penta- and hexacyclic ring A, 21-acetyl-20,28-epoxy-18α,19βH-ursane-isomeric cycle E, was carry out. (3R,5R)-19β,28-Epoxy-4,5-seco-18α-olean-3(5)-ozonide and 2,3-indolo-21β-acetyl-20β,28-epoxy-18α, H-19β-ursane showed significant cytotoxic activity against melanoma MeWo and Leukemia SR cells, appropriately. (3S,5S)-Diastereomer of the first compound showed no cytotoxicity. PMID:25895356

  3. Spectrum and Possible Mechanism of Carrageenan Cytotoxicity

    PubMed Central

    Catanzaro, Phillip J.; Schwartz, Howard J.; Graham, Richard C.

    1971-01-01

    Carrageenan, a sulfated polygalactose which suppresses established delayed hypersensitivity in vivo, is shown to be cytotoxic to macrophages but not to lymphocytes in vitro. This cytotoxicity depends on the carrageenan concentration and degree of lysosomal differentiation but is independent of serum. Survival of macrophages in the presence of carrageenan can be enhanced temporarily by corticosteroids. Ultrastructural studies reveal that carrageenan is readily taken up by macrophages and stored in lysosomes, which subsequently swell and rupture, apparently resulting in cell death. The presence of corticosteroids temporarily retards lysosome swelling. It is suggested that carrageenan may exert its cytotoxic effect by causing osmotic rupture of lysosomes. The possible immunologic significance of these findings is discussed. ImagesFig 3Fig 4Fig 2Fig 5Fig 6Fig 1 PMID:5142272

  4. Cytotoxic triterpenoid saponins from Clematis tangutica.

    PubMed

    Zhao, Min; Da-Wa, Zhuo-Ma; Guo, Da-Le; Fang, Dong-Mei; Chen, Xiao-Zhen; Xu, Hong-Xi; Gu, Yu-Cheng; Xia, Bing; Chen, Lei; Ding, Li-Sheng; Zhou, Yan

    2016-10-01

    Eight previously undescribed oleanane-type triterpenoid saponins, clematangoticosides A-H, together with eight known saponins, were isolated from the whole plants of Clematis tangutica (Maxim.) Korsh. Their structures were elucidated by extensive spectroscopic analysis, in combination with chemical methods (acid hydrolysis and mild alkaline hydrolysis). Clematangoticosides D-G were found to be unusual 23, 28-bidesmosidic glycosides. The cytotoxic activities of all of the isolated saponins were evaluated against the four human cancer cell lines SGC-7901, HepG2, HL-60 and U251MG. Clematoside S, sapindoside B, kalopanax saponin A, and koelreuteria saponin A exhibited cytotoxicity against all of the test cancer cell lines with IC50 values in the range of 1.88-27.20 μM, while clematangoticoside D and F showed selective cytotoxicity against SGC-7901 with IC50 values of 24.22 and 21.35 μM, respectively. PMID:27262876

  5. Cellular energy metabolism

    SciTech Connect

    Glaser, M.

    1991-06-01

    Studies have been carried out on adenylate kinase which is an important enzyme in determining the concentrations of the adenine nucleotides. An efficient method has been developed to clone mutant adenylate kinase genes in E. coli. Site-specific mutagenesis of the wild type gene also has been used to obtain forms of adenylate kinase with altered amino acids. The wild type and mutant forms of adenylate kinase have been overexpressed and large quantities were readily isolated. The kinetic and fluorescence properties of the different forms of adenylate kinase were characterized. This has led to a new model for the location of the AMP and ATP bindings sites on the enzyme and a proposal for the mechanism of substrate inhibition. Crystals of the wild type enzyme were obtained that diffract to at least 2.3 {angstrom} resolution. Experiments were also initiated to determine the function of adenylate kinase in vivo. In one set of experiments, E. coli strains with mutations in adenylate kinase showed large changes in cellular nucleotides after reaching the stationary phase in a low phosphate medium. This was caused by selective proteolytic degradation of the mutant adenylate kinase caused by phosphate starvation.

  6. Molecular and Cellular Biophysics

    NASA Astrophysics Data System (ADS)

    Jackson, Meyer B.

    2006-01-01

    Molecular and Cellular Biophysics provides advanced undergraduate and graduate students with a foundation in the basic concepts of biophysics. Students who have taken physical chemistry and calculus courses will find this book an accessible and valuable aid in learning how these concepts can be used in biological research. The text provides a rigorous treatment of the fundamental theories in biophysics and illustrates their application with examples. Conformational transitions of proteins are studied first using thermodynamics, and subsequently with kinetics. Allosteric theory is developed as the synthesis of conformational transitions and association reactions. Basic ideas of thermodynamics and kinetics are applied to topics such as protein folding, enzyme catalysis and ion channel permeation. These concepts are then used as the building blocks in a treatment of membrane excitability. Through these examples, students will gain an understanding of the general importance and broad applicability of biophysical principles to biological problems. Offers a unique synthesis of concepts across a wide range of biophysical topics Provides a rigorous theoretical treatment, alongside applications in biological systems Author has been teaching biophysics for nearly 25 years

  7. Electrosurgery with cellular precision.

    PubMed

    Palanker, Daniel V; Vankov, Alexander; Huie, Philip

    2008-02-01

    Electrosurgery, one of the most-often used surgical tools, is a robust but somewhat crude technology that has changed surprisingly little since its invention almost a century ago. Continuous radiofrequency is still used for tissue cutting, with thermal damage extending to hundreds of micrometers. In contrast, lasers developed 70 years later, have been constantly perfected, and the laser-tissue interactions explored in great detail, which has allowed tissue ablation with cellular precision in many laser applications. We discuss mechanisms of tissue damage by electric field, and demonstrate that electrosurgery with properly optimized waveforms and microelectrodes can rival many advanced lasers. Pulsed electric waveforms with burst durations ranging from 10 to 100 micros applied via insulated planar electrodes with 12 microm wide exposed edges produced plasma-mediated dissection of tissues with the collateral damage zone ranging from 2 to 10 microm. Length of the electrodes can vary from micrometers to centimeters and all types of soft tissues-from membranes to cartilage and skin could be dissected in liquid medium and in a dry field. This technology may allow for major improvements in outcomes of the current surgical procedures and development of much more refined surgical techniques. PMID:18270030

  8. Active Cellular Nematics

    NASA Astrophysics Data System (ADS)

    Duclos, Guillaume; Erlenkaemper, Christoph; Garcia, Simon; Yevick, Hannah; Joanny, Jean-François; Silberzan, Pascal; Biology inspired physics at mesoscales Team; Physical approach of biological problems Team

    We study the emergence of a nematic order in a two-dimensional tissue of apolar elongated fibroblast cells. Initially, these cells are very motile and the monolayer is characterized by giant density fluctuations, a signature of far-from-equilibrium systems. As the cell density increases because of proliferation, the cells align with each other forming large perfectly oriented domains while the cellular movements slow down and eventually freeze. Therefore topological defects characteristic of nematic phases remain trapped at long times, preventing the development of infinite domains. By analogy with classical non-active nematics, we have investigated the role of boundaries and we have shown that cells confined in stripes of width smaller than typically 500 µm are perfectly aligned in the stripe direction. Experiments performed in cross-shaped patterns show that both the number of cells and the degree of alignment impact the final orientation. Reference: Duclos G., Garcia S., Yevick H.G. and Silberzan P., ''Perfect nematic order in confined monolayers of spindle-shaped cells'', Soft Matter, 10, 14, 2014

  9. Structure-property relationship in cytotoxicity and cell uptake of poly(2-oxazoline) amphiphiles

    PubMed Central

    Luxenhofer, Robert; Sahay, Gaurav; Schulz, Anita; Alakhova, Daria; Bronich, Tatiana K.; Jordan, Rainer; Kabanov, Alexander V.

    2011-01-01

    The family of poly(2-oxazoline)s (POx) is being increasingly investigated in the context of biomedical applications. We tested the relative cytotoxicity of POx and were able to confirm that these polymers are typically not cytotoxic even at high concentrations. Furthermore, we report structure-uptake relationships of a series of amphiphilic POx block copolymers that have different architectures, molar mass and chain termini. The rate of endocytosis can be fine-tuned over a broad range by changing the polymer structure. The cellular uptake increases with the hydrophobic character of the polymers and is observed even at nanomolar concentrations. Considering the structural versatility of this class of polymers, the relative ease of preparation and their stability underlines the potential of POx as a promising platform candidate for the preparation of next-generation polymer therapeutics. PMID:21513750

  10. Protein-binding, cytotoxicity in vitro and cell cycle arrest of ruthenium(II) polypyridyl complexes

    NASA Astrophysics Data System (ADS)

    Liu, Si-Hong; Zhu, Jian-Wei; Xu, Hui-Hua; Wang, Yan; Liu, Ya-Min; Liang, Jun-Bo; Zhang, Gui-Qiang; Cao, Di-Hua; Lin, Yang-Yang; Wu, Yong; Guo, Qi-Feng

    2016-05-01

    The cytotoxic activity of two Ru(II) complexes against A549, BEL-7402, HeLa, PC-12, SGC-7901 and SiHa cell lines was investigated by MTT method. Complexes 1 and 2 show moderate cytotoxicity toward BEL-7402 cells with an IC50 value of 53.9 ± 3.4 and 39.3 ± 2.1 μM. The effects of the complexes inducing apoptosis, cellular uptake, reactive oxygen species and mitochondrial membrane potential in BEL-7402 cells have been studied by fluorescence microscopy. The percentages of apoptotic and necrotic cells and cell cycle arrest were studied by flow cytometry. The BSA-binding behaviors were investigated by UV/visible and fluorescent spectra.

  11. Glutathione and S-nitrosoglutathione in alginate/chitosan nanoparticles: Cytotoxicity

    NASA Astrophysics Data System (ADS)

    Marcato, P. D.; Adami, L. F.; Melo, P. S.; de Paula, L. B.; Durán, N.; Seabra, A. B.

    2011-07-01

    Nitric oxide (NO) is involved in several physiological processes, such as the control of vascular tone, the immune response and the wound healing process. Thus, there is a great interest in the development of NO-releasing drugs and in matrices which are able to stabilize and release NO locally in different tissues. Thiols, such as glutathione (GSH), are ready nitrosated to form the NO donors S-nitrosothiols (RSNOs). In this work, GSH, a precursor of the NO donor S-nitrosoglutathione (GSNO), was encapsulated into a mucoadhesive combination of alginate/chitosan nanoparticles. The encapsulated GSH was nitrosated in the alginate/chitosan nanoparticles by adding sodium nitrite, leading to the formation of encapsulated GSNO. The cytotoxicity characterization of the nanoparticles containing either GSH or GSNO showed that these materials were completely non cytotoxic to cellular viability. These results show that this novel nanostructure biomaterial has a great potential to be use in biomedical applications where NO has a therapeutical effect.

  12. Suppression of nanoparticle cytotoxicity approaching in vivo serum concentrations: limitations of in vitro testing for nanosafety

    NASA Astrophysics Data System (ADS)

    KimPresent Address: Institute Of Pharmaceutical Sciences, Department Of Chemistry; Applied Biosciences, Eth Zurich, Vladimir-Prelog-Weg 1-5/10, 8093 Zurich, Switzerland., Jong Ah; SalvatiPresent Address: Division Of Pharmacokinetics, Toxicology; Targeting, Department Of Pharmacy, Antonius Deusinglaan 1, 9713 Av Groningen, The Netherlands., Anna; ÅbergPresent Address: Groningen Institute Of Biomolecular Sciences; Biotechnology, University Of Groningen, Nijenborgh 4, 9747 Ag Groningen, The Netherlands., Christoffer; Dawson, Kenneth A.

    2014-11-01

    Nanomaterials challenge paradigms of in vitro testing because unlike molecular species, biomolecules in the dispersion medium modulate their interactions with cells. Exposing cells to nanoparticles known to cause cell death, we observed cytotoxicity suppression by increasing the amount of serum in the dispersion medium towards in vivo-relevant conditions.Nanomaterials challenge paradigms of in vitro testing because unlike molecular species, biomolecules in the dispersion medium modulate their interactions with cells. Exposing cells to nanoparticles known to cause cell death, we observed cytotoxicity suppression by increasing the amount of serum in the dispersion medium towards in vivo-relevant conditions. Electronic supplementary information (ESI) available: Experimental procedures; cell viability, proliferation and endocytosis levels of cultures grown in the relevant media; cellular uptake and physicochemical characterisation by DCS of silica nanoparticles; physicochemical characterisation by DLS of the amino-modified polystyrene nanoparticles used in the relevant biological media. See DOI: 10.1039/c4nr04970e

  13. Daunomycin-loaded superparamagnetic iron oxide nanoparticles: Preparation, magnetic targeting, cell cytotoxicity, and protein delivery research.

    PubMed

    Liu, Min-Chao; Jin, Shu-Fang; Zheng, Min; Wang, Yan; Zhao, Peng-Liang; Tang, Ding-Tong; Chen, Jiong; Lin, Jia-Qi; Wang, Xia-Hong; Zhao, Ping

    2016-08-01

    The clinical use of daunomycin is restricted by dose-dependent toxicity and low specificity against cancer cells. In the present study, modified superparamagnetic iron oxide nanoparticles were employed to load daunomycin and the drug-loaded nanospheres exhibited satisfactory size and smart pH-responsive release. The cellular uptake efficiency, targeted cell accumulation, and cell cytotoxicity experimental results proved that the superparamagnetic iron oxide nanoparticle-loading process brings high drug targeting without decreasing the cytotoxicity of daunomycin. Moreover, a new concern for the evaluation of nanophase drug delivery's effects was considered, with monitoring the interactions between human serum albumin and the drug-loaded nanospheres. Results from the multispectroscopic techniques and molecular modeling calculation elucidate that the drug delivery has detectable deleterious effects on the frame conformation of protein, which may affect its physiological function. PMID:27288463

  14. CdTe and CdSe Quantum Dots Cytotoxicity: A Comparative Study on Microorganisms

    PubMed Central

    Gomes, Suzete A.O.; Vieira, Cecilia Stahl; Almeida, Diogo B.; Santos-Mallet, Jacenir R.; Menna-Barreto, Rubem F. S.; Cesar, Carlos L.; Feder, Denise

    2011-01-01

    Quantum dots (QDs) are colloidal semiconductor nanocrystals of a few nanometers in diameter, being their size and shape controlled during the synthesis. They are synthesized from atoms of group II–VI or III–V of the periodic table, such as cadmium telluride (CdTe) or cadmium selenium (CdSe) forming nanoparticles with fluorescent characteristics superior to current fluorophores. The excellent optical characteristics of quantum dots make them applied widely in the field of life sciences. Cellular uptake of QDs, location and translocation as well as any biological consequence, such as cytotoxicity, stimulated a lot of scientific research in this area. Several studies pointed to the cytotoxic effect against micoorganisms. In this mini-review, we overviewed the synthesis and optical properties of QDs, and its advantages and bioapplications in the studies about microorganisms such as protozoa, bacteria, fungi and virus. PMID:22247686

  15. Cytotoxicity of a GalNAc-specific C-type lectin CEL-I toward various cell lines.

    PubMed

    Kuramoto, Takuya; Uzuyama, Hitomi; Hatakeyama, Tomomitsu; Tamura, Tadashi; Nakashima, Takuji; Yamaguchi, Kenichi; Oda, Tatsuya

    2005-01-01

    We found that CEL-I was a potent cytotoxic lectin. MDCK, HeLa, and XC cells were highly sensitive to CEL-I cytotoxicity and killed in a dose-dependent manner, whereas CHO, L929, and RAW264.7 cells were relatively resistant to CEL-I, and no significant toxicity was observed up to 10 microg/ml. Among these cell lines, MDCK cells showed the highest susceptibility to CEL-I cytotoxicity. A binding study using FITC-labeled CEL-I (F-CEL-I) revealed that the amounts of bound F-CEL-I on the sensitive cell lines were evidently greater than those on the resistant cell lines, suggesting that the different susceptibility of the cell lines to CEL-I cytotoxicity is partly explained by different efficiencies of binding of CEL-I to these cell lines. Interestingly, the cytotoxicity of CEL-I toward MDCK cells was more potent than those of other lectins such as WGA, PHA-L, and Con A, even though these lectins were capable of binding to MDCK cells at comparable levels to CEL-I. Since the cytotoxicity of CEL-I was strongly inhibited by GalNAc, the binding to cell surface specific carbohydrates is essential for the CEL-I cytotoxicity. The trypan blue dye exclusion test indicated that CEL-I caused a disorder of plasma membrane integrity as a relatively early event. CEL-I failed to induce the release of carboxyfluorescein (CF) from CF-loaded MDCK cells as seen for pore-forming hemolytic isolectin CEL-III, suggesting that the primary cellular target of CEL-I may be the plasma membrane, but its action mechanism differs from that of CEL-III. Although CEL-I induced dramatic cellular morphological changes in MDCK cells, neither typical apoptotic nuclear morphological changes nor DNA fragmentation was observed in CEL-I-treated MDCK cells even after such cellular changes. Our results demonstrated that CEL-I showed a potent cytotoxic effect, especially on MDCK cells, by causing plasma membrane disorder without induction of apoptosis. PMID:15713882

  16. Cytotoxic and antiplasmodial xanthones from Pentadesma butyracea.

    PubMed

    Zelefack, Fabien; Guilet, David; Fabre, Nicolas; Bayet, Christine; Chevalley, Séverine; Ngouela, Silvère; Lenta, Bruno Ndjakou; Valentin, Alexis; Tsamo, Etienne; Dijoux-Franca, Marie-Geneviève

    2009-05-22

    Four new xanthones, butyraxanthones A-D (1-4), were isolated from the stem bark of Pentadesma butyracea, together with six known xanthones (5-10) and a triterpenoid (lupeol). The structures of 1-4 were established by spectroscopic methods. Compounds 1-10 were tested in vitro for antiplasmodial activity against a Plasmodium falciparum chloroquine-resistant strain and for cytotoxicity against a human breast cancer cell line (MCF-7). Nearly all of these xanthones exhibited good antiplasmodial activity, and some of them also demonstrated potent cytotoxicity. PMID:19296616

  17. Cytotoxic Terpene Quinones from Marine Sponges

    PubMed Central

    Gordaliza, Marina

    2010-01-01

    The 1,4-benzoquinone moiety is a common structural feature in a large number of compounds that have received considerable attention owing to their broad spectrum of biological activities. The cytotoxic and antiproliferative properties of many natural sesquiterpene quinones and hydroquinones from sponges of the order Dictyoceratida, such as avarol, avarone, illimaquinone, nakijiquinone and bolinaquinone, offer promising opportunities for the development of new antitumor agents. The present review summarizes the structure and cytotoxicity of natural terpenequinones/hydroquinones and their bioactive analogues and derivatives. PMID:21339953

  18. Nucleotide chloramines and neutrophil-mediated cytotoxicity.

    PubMed

    Bernofsky, C

    1991-03-01

    Hypochlorite is a reactive oxidant formed as an end product of the respiratory burst in activated neutrophils. It is responsible for killing bacteria and has been implicated in neutrophil-mediated tissue injury associated with the inflammatory process. Although hypochlorite is a potent cytotoxic agent, the primary mechanism by which it exerts its effect is unclear. This review examines evidence that the primary event in hypochlorite cytotoxicity is the loss of adenine nucleotides from the target cell. This loss appears to be mediated by the formation of adenine nucleotide chloramines which are reactive intermediates with a free radical character and are capable of forming stable ligands with proteins and nucleic acids. PMID:1848195

  19. Cytotoxic polycyclic polyprenylated acylphloroglucinols from Hypericum attenuatum.

    PubMed

    Zhou, Zhong-bo; Zhang, Yang-mei; Pan, Ke; Luo, Jian-guang; Kong, Ling-yi

    2014-06-01

    Six new polycyclic polyprenylated acylphloroglucinols, attenuatumiones A-F (1-6), together with twelve known analogs (7-18) were isolated from the whole plant of Hypericum attenuatum. Their structures were elucidated by spectroscopic methods, and the absolute configuration of C-13 in attenuatumione C (3) was deduced via the circular dichroism datum of the in situ formed [Rh2(OCOCF3)4] complexes. All isolates were evaluated for the cytotoxic activities on three human cancer cell lines. Compound 3 showed moderate cytotoxic activities with IC50 values of 10.12 and 10.56 μM against SMMC7721 and U2OS, respectively. PMID:24603092

  20. Cellular proliferation, cellular viability, and biocompatibility of HA-ZnO composites.

    PubMed

    Saha, Naresh; Dubey, Ashutosh K; Basu, Bikramjit

    2012-01-01

    One of the important issues in the development of hydroxyapatite (HA)-based biomaterials is the prosthetic infection, which limits wider use of monolithic HA despite superior cellular response. Recently, we reported that ZnO addition to HA can induce bactericidal property. It is therefore important to assess how ZnO addition influences the cytotoxicity property and cell adhesion/proliferation on HA-ZnO composite surfaces in vitro. In the above perspective, the objective of this study is to investigate the cell type and material composition dependent cellular proliferation and viability of pressureless sintered HA-ZnO composites. The combination of cell viability data as well as morphological observations of cultured human osteoblast-like SaOS2 cells and mouse fibroblast L929 cells suggests that HA-ZnO composites containing 10 Wt % or lower ZnO exhibit the ability to support cell adhesion and proliferation. Both SaOS2 and L929 cells exhibit extensive multidirectional network of actin cytoskeleton and cell flattening on the lower ZnO containing (≤10 Wt %) HA-ZnO composites. The in vitro results illustrate how variation in ZnO content can influence significantly the cell vitality, as evaluated using MTT biochemical assay. Also, the critical statistical analysis reveals that ZnO addition needs to be carefully tailored to ensure good in vitro cytocompatibility. The underlying reasons for difference in biological properties are analyzed. It is suggested that surface wettability as well as dissolution of ZnO, both contribute to the observed differences in cellular viability and proliferation. PMID:22102555

  1. [Cellular immunity state assessed in bronchial and alveolar lavage for experimental animals exposed to the rubber dust].

    PubMed

    Zhumabekova, B K; Karabalin, S K; Bakirova, R E

    2004-01-01

    Experiments on 21 rats helped to study influence of mechanical rubber dust on cellular immunity state in bronchial and alveolar lavage, efficiency of Ruvimine for prophylaxis. Findings are that mechanical rubber dust is strongly cytotoxic. Ruvimine administration during the whole experiment demonstrates therapeutic and prophylactic effect and normalizes local pulmonary phagocytosis. PMID:15318451

  2. 47 CFR 22.909 - Cellular markets.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Cellular markets. 22.909 Section 22.909... Cellular Radiotelephone Service § 22.909 Cellular markets. Cellular markets are standard geographic areas used by the FCC for administrative convenience in the licensing of cellular systems. Cellular...

  3. 47 CFR 22.909 - Cellular markets.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Cellular markets. 22.909 Section 22.909... Cellular Radiotelephone Service § 22.909 Cellular markets. Cellular markets are standard geographic areas used by the FCC for administrative convenience in the licensing of cellular systems. Cellular...

  4. Transmission electron microscopic analysis of malathion-induced cytotoxicity in granulosa cells of caprine antral follicles.

    PubMed

    Bhardwaj, Jitender Kumar; Saraf, Priyanka

    2016-01-01

    Malathion, one of the most abundantly used organophosphate pesticides, has immoderate potency as a cytotoxic and genotoxic compound that induces toxicity in granulosa cells, resulting in its apoptosis. Thus, the present study aims to employ ultrastructural analysis for assessing the cytotoxicity of malathion at nanomolar concentrations (1 nM and 10 nM) in granulosa cells of caprine antral follicles at different exposure durations. Transmission electron microscopy revealed diminished cell-cell contact and cellular integrity, presence of crescent-shaped nucleus, chromatin condensation, and pyknosis with nuclear membrane folding, accumulation of lipid droplets with occurrence of cytoplasmic protrusions in granulosa cells treated with 1 nM malathion, whereas at 10 nM concentration, along with apoptotic attributes, prominent association of nucleus, endoplasmic reticulum, mitochondria and lipid droplets, nucleus invagination into lipid droplets, apical localization of lipid bodies, and occurrence of autophagic body were observed as compared to healthy granulosa cells in control with normal intact cellular integrity, well-developed cellular association, and doubled membrane nuclear lamina with homogenously dispersed chromatin surrounded by intact mitochondria with well-developed cristae. Thus, the results of ultrastructural analysis clearly suggest that nanomolar concentration of malathion induces apoptotic hallmarks within the granulosa cells of antral follicles that play a consequential role in increasing the incidence of follicular atresia, thereby affecting the overall fertility. PMID:26513701

  5. Nanostructures Control the Hepatocellular Responses to a Cytotoxic Agent “Cisplatin”

    PubMed Central

    Abdellatef, Shimaa A.; Tange, Riho; Sato, Takeshi; Ohi, Akihiko; Nabatame, Toshihide; Taniguchi, Akiyoshi

    2015-01-01

    In drug discovery programs, the alteration between in vivo and in vitro cellular responses to drug represents one of the main challenges. Since the variation in the native extracellular matrix (ECM) between in vivo and 2D in vitro conditions is one of the key reasons for such discrepancies, thus the utilization of substrate that likely mimics ECM characteristics (topography, stiffness, and chemical composition) is needed to overcome such problem. Here, we investigated the role of substrate nanotopography as one of the major determinants of hepatic cellular responses to a chemotherapeutic agent “cisplatin.” We studied the substratum induced variations in cisplatin cytotoxicity; a higher cytotoxic response to cisplatin was observed for cells cultured on the nanopattern relative to a flat substrate. Moreover, the nanofeatures with grating shapes that mimic the topography of major ECM protein constituents (collagen) induced alterations in the cellular orientation and chromatin condensation compared to flat surfaces. Accordingly, the developments of biomimetic substrates with a particular topography could have potentials in drug development analyses to reflect more physiological mimicry conditions in vitro. PMID:26247032

  6. In vitro cytotoxicity assessment based on KC(50) with real-time cell analyzer (RTCA) assay.

    PubMed

    Pan, Tianhong; Khare, Swanand; Ackah, Fred; Huang, Biao; Zhang, Weiping; Gabos, Stephan; Jin, Can; Stampfl, Melinda

    2013-12-01

    Technological advances in cytotoxicity analysis have now made it possible to obtain real time data on changes in cell growth, morphology and cell death. This type of testing has a great potential for reducing and refining traditional in vivo toxicology tests. By monitoring the dynamic response profile of living cells via the xCELLigence real-time cell analyzer for high-throughput (RTCA HT) system, cellular changes including cell number (cell index, CI) are recorded and analyzed. A special scaled index defined as normalized cell index (NCI) is used in the analysis which reduces the influence of inter-experimental variations. To assess the extent of exposure of the tested chemicals, a two-exponent model is presented to describe rate of cell growth and death. This model is embodied in the time and concentration-dependent cellular response curves, and the parameters k1 and k2 in this model are used to describe the rate of cell growth and death. Based on calculated k2 values and the corresponding concentrations, a concentration-response curve is fitted. As a result, a cytotoxicity assessment named KC50 is calculated. The validation of the proposed method is demonstrated by exposing six cell lines to 14 chemical compounds. Our findings suggest that the proposed KC50-based toxicity assay can be an alternative to the traditional single time-point assay such as LC50 (the concentration at which 50% of the cells are killed). The proposed index has a potential for routine evaluation of cytotoxicities. Another advantage of the proposed index is that it extracts cytotoxicity information when CI fails to detect the low toxicity. PMID:24055763

  7. Biotinylated Platinum(II) Ferrocenylterpyridine Complexes for Targeted Photoinduced Cytotoxicity.

    PubMed

    Mitra, Koushambi; Shettar, Abhijith; Kondaiah, Paturu; Chakravarty, Akhil R

    2016-06-01

    Biotinylated platinum(II) ferrocenylterpyridine (Fc-tpy) complexes [Pt(Fc-tpy)(L(1))]Cl (1) and [Pt(Fc-tpy)(L(2))]Cl (2), where HL(1) and HL(2) are biotin-containing ligands, were prepared, and their targeted photoinduced cytotoxic effect in cancer cells over normal cells was studied. A nonbiotinylated complex, [Pt(Fc-tpy)(L(3))]Cl (3), was prepared as a control to study the role of the biotin moiety in cellular uptake properties of the complexes. Three platinum(II) phenylterpyridine (Ph-tpy) complexes, viz., [Pt(Ph-tpy)(L(1))]Cl (4), [Pt(Ph-tpy)(L(2))]Cl (5), and [Pt(Ph-tpy)(L(3))]Cl (6), were synthesized and explored to understand the role of a metal-bound Fc-tpy ligand over Ph-tpy as a photoinitiator. The Fc-tpy complexes displayed an intense absorption band near 640 nm, which was absent in their Ph-tpy analogues. The Fc-tpy complexes (1 mM in 0.1 M TBAP) showed an irreversible cyclic voltammetric anodic response of the Fc/Fc(+) couple near 0.25 V. The Fc-tpy complexes displayed photodegradation in red light of 647 nm involving the formation of a ferrocenium ion (Fc(+)) and reactive oxygen species (ROS). Photoinduced release of the biotinylated ligands was observed from spectral measurements, and this possibly led to the controlled generation of an active platinum(II) species, which binds to the calf-thymus DNA used for this study. The biotinylated photoactive Fc-tpy complexes showed significant photoinduced cytotoxicity, giving a IC50 value of ∼7 μM in visible light of 400-700 nm with selective uptake in BT474 cancer cells over HBL-100 normal cells. Furthermore, ferrocenyl complexes resulted in light-induced ROS-mediated apoptosis, as indicated by DCFDA, annexin V/FITC staining, and sub-G1 DNA content determined by fluorescent activated cell sorting analysis. The phenyl analogues 4 and 5 were photostable, served as DNA intercalators, and demonstrated selective cytotoxicity in the cancer cells, giving IC50 values of ∼4 μM. PMID:27171926

  8. Interaction of Eu(III) with mammalian cells: Cytotoxicity, uptake, and speciation as a function of Eu(III) concentration and nutrient composition.

    PubMed

    Sachs, Susanne; Heller, Anne; Weiss, Stephan; Bok, Frank; Bernhard, Gert

    2015-10-01

    In case of the release of lanthanides and actinides into the environment, knowledge about their behavior in biological systems is necessary to assess and prevent adverse health effects for humans. We investigated the interaction of europium with FaDu cells (human squamous cell carcinoma cell line) combining analytical methods, spectroscopy, and thermodynamic modeling with in-vitro cell experiments under defined conditions. Both the cytotoxicity of Eu(III) onto FaDu cells and its cellular uptake are mainly concentration-dependent. Moreover, they are governed by its chemical speciation in the nutrient medium. In complete cell culture medium, i.e., in the presence of fetal bovine serum, Eu(III) is stabilized in solution in a wide concentration range by complexation with serum proteins resulting in low cytotoxicity and cellular Eu(III) uptake. In serum-free medium, Eu(III) precipitates as hardly soluble phosphate species, exhibiting a significantly higher cytotoxicity and slightly higher cellular uptake. The presence of a tenfold excess of citrate in serum-free medium causes the formation of Eu(HCit)2(3-) complexes in addition to the dominating Eu(III) phosphate species, resulting in a decreased Eu(III) cytotoxicity and cellular uptake. The results of this study underline the crucial role of a metal ion's speciation for its toxicity and bioavailability. PMID:26055652

  9. Effects of Iron-Oxide Nanoparticle Surface Chemistry on Uptake Kinetics and Cytotoxicity in CHO-K1 Cells

    PubMed Central

    Hanot, Camille C.; Choi, Young Suk; Anani, Tareq B.; Soundarrajan, Dharsan; David, Allan E.

    2015-01-01

    Superparamagnetic iron-oxide nanoparticles (SPIONs) show great promise for multiple applications in biomedicine. While a number of studies have examined their safety profile, the toxicity of these particles on reproductive organs remains uncertain. The goal of this study was to evaluate the cytotoxicity of starch-coated, aminated, and PEGylated SPIONs on a cell line derived from Chinese Hamster ovaries (CHO-K1 cells). We evaluated the effect of particle diameter (50 and 100 nm) and polyethylene glycol (PEG) chain length (2k, 5k and 20k Da) on the cytotoxicity of SPIONs by investigating cell viability using the tetrazolium dye 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and sulforhodamine B (SRB) assays. The kinetics and extent of SPION uptake by CHO-K1 cells was also studied, as well as the resulting generation of intracellular reactive oxygen species (ROS). Cell toxicity profiles of SPIONs correlated strongly with their cellular uptake kinetics, which was strongly dependent on surface properties of the particles. PEGylation caused a decrease in both uptake and cytotoxicity compared to aminated SPIONs. Interestingly, 2k Da PEG-modifed SPIONs displayed the lowest cellular uptake and cytotoxicity among all studied particles. These results emphasize the importance of surface coatings when engineering nanoparticles for biomedical applications. PMID:26729108

  10. MSAT and cellular hybrid networking

    NASA Technical Reports Server (NTRS)

    Baranowsky, Patrick W., II

    1993-01-01

    Westinghouse Electric Corporation is developing both the Communications Ground Segment and the Series 1000 Mobile Phone for American Mobile Satellite Corporation's (AMSC's) Mobile Satellite (MSAT) system. The success of the voice services portion of this system depends, to some extent, upon the interoperability of the cellular network and the satellite communication circuit switched communication channels. This paper will describe the set of user-selectable cellular interoperable modes (cellular first/satellite second, etc.) provided by the Mobile Phone and described how they are implemented with the ground segment. Topics including roaming registration and cellular-to-satellite 'seamless' call handoff will be discussed, along with the relevant Interim Standard IS-41 Revision B Cellular Radiotelecommunications Intersystem Operations and IOS-553 Mobile Station - Land Station Compatibility Specification.

  11. Cytotoxicity and cell cycle effects of novel indolo[2,3-b]quinoline derivatives.

    PubMed

    Humeniuk, Rita; Kaczmarek, Lukasz; Peczyńska-Czoch, Wanda; Marcinkowska, Ewa

    2003-01-01

    Cellular effects of novel indolo[2,3-b]quinoline derivatives were studied. These compounds are synthetic analogs of plant alkaloid neocryptolepine (5-methyl-5H-indolo[2,3-b]quinoline) present in extracts from Cryptolepis sanguinolenta. They are traditionally used in natural medicine in Central and West Africa. Previous molecular and computational studies indicated that these compounds were DNA intercalators and inhibitors of topoisomerase II. We have extended our studies on their mode of action to the cellular level. Past experiments have shown that these compounds were active in vitro against cell lines derived from solid tumors, so for the present studies we selected leukemic cell lines. Jurkat acute T cell, CCRF-CEM T lymphoblastoid, THP-1 acute monocytic, HL-60 acute promyelocytic leukemias, and HL-60/MX2 subline with reduced expression of topoisomerase II were used. We evaluated the cytotoxicity and cell cycle effects of the indolo[2,3-b]quinoline compounds. We also tested if these compounds were able to induce apoptosis in the cells. Our studies revealed that novel indolo[2,3-b]quinoline derivatives were more cytotoxic to all cell lines than etoposide (used as a reference topoisomerase II inhibitor), and that their cytotoxicity depended on the substituents introduced to the indolo[2,3-b]quinoline core. Surprisingly, our studies have shown that HL-60/MX2 cell line and also THP-1 cell line, resistant to etoposide, were susceptible to methyl- and methoxy-substituted indolo[2,3-b]quinoline derivatives. In parallel to the evaluation of cytotoxicity we studied cell cycle effects of these compounds. Treatment of HL-60 cells with etoposide in subcytotoxic concentrations resulted in a massive accumulation of the cells in the G2/M phase of the cell cycle. When we used subcytotoxic concentrations of our novel indolo[2,3-b]quinoline derivatives the cell cycle progression of HL-60 cells was not affected. Moreover, the cell cycle of HL-60/MX2 cells was not influenced by

  12. New cytotoxic cucurbitacins from Wilbrandia ebracteata Cogn.

    PubMed

    Lang, Karen L; da Rosa Guimarães, Tatiana; Rocha Machado, Vanessa; Zimmermann, Lara A; Silva, Izabella T; Teixeira, Marina R; Durán, Fernando J; Palermo, Jorge A; Simões, Cláudia M O; Caro, Miguel S B; Schenkel, Eloir P

    2011-09-01

    Chemical investigation of the roots of Wilbrandia ebracteata Cogn. (Cucurbitaceae) led to the isolation of two new (1- 2) and four known (3- 6) cucurbitacins. Their structures were elucidated by NMR and MS and compared with related compounds. The in vitro cytotoxicity of isolated compounds was evaluated against RD, KB, HCT-8, and A549 cell lines showing strong activity. PMID:21472651

  13. Cytotoxic activity of four Mexican medicinal plants.

    PubMed

    Vega-Avila, Elisa; Espejo-Serna, Adolfo; Alarcón-Aguilar, Francisco; Velasco-Lezama, Rodolfo

    2009-01-01

    Ibervillea sonorae Greene, Cucurbita ficifolia Bouché, Tagetes lucida Cav and Justicia spicigera Scheltdd are Mexican native plants used in the treatment of different illnesses. The ethanolic extract of J. spicigera and T. lucida as well as aqueous extracts from I. sonorae, C. ficifolia, T. lucida and J. spicigera were investigated using sulforhodamine B assay. These extracts were assessed using two cell line: T47D (Human Breast cancer) and HeLa (Human cervix cancer). Colchicine was used as the positive control. Data are presented as the dose that inhibited 50% control growth (ED50). All of the assessed extracts were cytotoxic (ED50 < 20 microg/ml) against T47D cell line, meanwhile only the aqueous extract from T. lucida and the ethanolic extract from J. spicigera were cytotoxic to HeLa cell line. Ethanolic extract from J. spicigera presented the best cytotoxic effect. The cytotoxic activity of J. spicigera correlated with one of the popular uses, the treatment of cancer. PMID:22128430

  14. Cytotoxicity potentials of eleven Bangladeshi medicinal plants.

    PubMed

    Khatun, Amina; Rahman, Mahmudur; Haque, Tania; Rahman, Md Mahfizur; Akter, Mahfuja; Akter, Subarna; Jhumur, Afrin

    2014-01-01

    Various forms of cancer are rising all over the world, requiring newer therapy. The quest of anticancer drugs both from natural and synthetic sources is the demand of time. In this study, fourteen extracts of different parts of eleven Bangladeshi medicinal plants which have been traditionally used for the treatment of different types of carcinoma, tumor, leprosy, and diseases associated with cancer were evaluated for their cytotoxicity for the first time. Extraction was conceded using methanol. Phytochemical groups like reducing sugars, tannins, saponins, steroids, gums, flavonoids, and alkaloids were tested using standard chromogenic reagents. Plants were evaluated for cytotoxicity by brine shrimp lethality bioassay using Artemia salina comparing with standard anticancer drug vincristine sulphate. All the extracts showed potent to moderate cytotoxicity ranging from LC50 2 to 115 µg/mL. The highest toxicity was shown by Hygrophila spinosa seeds (LC50 = 2.93 µg/mL) and the lowest by Litsea glutinosa leaves (LC50 = 114.71 µg/mL) in comparison with standard vincristine sulphate (LC50 = 2.04 µg/mL). Among the plants, the plants traditionally used in different cancer and microbial treatments showed highest cytotoxicity. The results support their ethnomedicinal uses and require advanced investigation to elucidate responsible compounds as well as their mode of action. PMID:25431796

  15. Cytotoxicity Potentials of Eleven Bangladeshi Medicinal Plants

    PubMed Central

    Haque, Tania; Akter, Mahfuja; Akter, Subarna; Jhumur, Afrin

    2014-01-01

    Various forms of cancer are rising all over the world, requiring newer therapy. The quest of anticancer drugs both from natural and synthetic sources is the demand of time. In this study, fourteen extracts of different parts of eleven Bangladeshi medicinal plants which have been traditionally used for the treatment of different types of carcinoma, tumor, leprosy, and diseases associated with cancer were evaluated for their cytotoxicity for the first time. Extraction was conceded using methanol. Phytochemical groups like reducing sugars, tannins, saponins, steroids, gums, flavonoids, and alkaloids were tested using standard chromogenic reagents. Plants were evaluated for cytotoxicity by brine shrimp lethality bioassay using Artemia salina comparing with standard anticancer drug vincristine sulphate. All the extracts showed potent to moderate cytotoxicity ranging from LC50 2 to 115 µg/mL. The highest toxicity was shown by Hygrophila spinosa seeds (LC50 = 2.93 µg/mL) and the lowest by Litsea glutinosa leaves (LC50 = 114.71 µg/mL) in comparison with standard vincristine sulphate (LC50 = 2.04 µg/mL). Among the plants, the plants traditionally used in different cancer and microbial treatments showed highest cytotoxicity. The results support their ethnomedicinal uses and require advanced investigation to elucidate responsible compounds as well as their mode of action. PMID:25431796

  16. Cytotoxicity of the rhizome of medicinal plants

    PubMed Central

    Hossain, Shakhawoat; Kader, Golam; Nikkon, Farjana; Yeasmin, Tanzima

    2012-01-01

    Objective To investigate the cytotoxicity of the crude ethanol extract of the rhizome of Zingiber zerumbet (Z. zerumbet) (L) Smith. and Curcuma zedoaria (C. zedoaria) Rosc. against Artemia salina Leach. Methods Fresh rhizomes of Z. zerumbet (L) Smith. and C. zedoaria Rosc. were extracted separately in cold with ethanol (2.5 L) and after concentration a brownish syrupy suspension of ethanol extracts of Z. zerumbet (L) Smith. and C. zedoaria Rosc. was obtained. The cytotoxic effect of the crude ethanol extracts of both plants was determined by brine shrimp lethality bioassay. Results Crude ethanol extracts of the rhizome of Z. zerumbet (L) Smith. showed the highest cytotoxicity (LC50 was 1.24 µg/mL) against brine shrimp nauplii as compared with C. zedoaria Rosc. (LC50 was 33.593 µg/mL) after 24 h of exposure. Conclusions It can be concluded that the rhizome of Z. zerumbet (L) Smith. and C. zedoaria Rosc. can be used as a source of cytotoxic agent. PMID:23569881

  17. Size-dependent cytotoxicity of Fe3O4 nanoparticles induced by biphasic regulation of oxidative stress in different human hepatoma cells

    PubMed Central

    Xie, Yuexia; Liu, Dejun; Cai, Chenlei; Chen, Xiaojing; Zhou, Yan; Wu, Liangliang; Sun, Yongwei; Dai, Huili; Kong, Xianming; Liu, Peifeng

    2016-01-01

    The application of Fe3O4 nanoparticles (NPs) has made great progress in the diagnosis of disease and in the drug delivery system for cancer therapy, but the relative mechanisms of potential toxicity induced by Fe3O4 have not kept pace with its development in the application, which has hampered its further clinical application. In this article, we used two kinds of human hepatoma cell lines, SK-Hep-1 and Hep3B, to investigate the cytotoxic effects and the involved mechanisms of small Fe3O4 NPs with different diameters (6 nm, 9 nm, and 14 nm). Results showed that the size of NPs effectively influences the cytotoxicity of hepatoma cells: 6 nm Fe3O4 NPs exhibited negligible cytotoxicity and 9 nm Fe3O4 NPs affected cytotoxicity via cellular mitochondrial dysfunction and by inducing necrosis mediated through the mitochondria-dependent intracellular reactive oxygen species generation. Meanwhile, 14 nm Fe3O4 NPs induced cytotoxicity by impairing the integrity of plasma membrane and promoting massive lactate dehydrogenase leakage. These results explain the detailed mechanism of different diameters of small Fe3O4 NPs-induced cytotoxicity. We anticipate that this study will provide different insights into the cytotoxicity mechanism of Fe3O4 NPs, so as to make them safer to use in clinical application. PMID:27536098

  18. Size-dependent cytotoxicity of Fe3O4 nanoparticles induced by biphasic regulation of oxidative stress in different human hepatoma cells.

    PubMed

    Xie, Yuexia; Liu, Dejun; Cai, Chenlei; Chen, Xiaojing; Zhou, Yan; Wu, Liangliang; Sun, Yongwei; Dai, Huili; Kong, Xianming; Liu, Peifeng

    2016-01-01

    The application of Fe3O4 nanoparticles (NPs) has made great progress in the diagnosis of disease and in the drug delivery system for cancer therapy, but the relative mechanisms of potential toxicity induced by Fe3O4 have not kept pace with its development in the application, which has hampered its further clinical application. In this article, we used two kinds of human hepatoma cell lines, SK-Hep-1 and Hep3B, to investigate the cytotoxic effects and the involved mechanisms of small Fe3O4 NPs with different diameters (6 nm, 9 nm, and 14 nm). Results showed that the size of NPs effectively influences the cytotoxicity of hepatoma cells: 6 nm Fe3O4 NPs exhibited negligible cytotoxicity and 9 nm Fe3O4 NPs affected cytotoxicity via cellular mitochondrial dysfunction and by inducing necrosis mediated through the mitochondria-dependent intracellular reactive oxygen species generation. Meanwhile, 14 nm Fe3O4 NPs induced cytotoxicity by impairing the integrity of plasma membrane and promoting massive lactate dehydrogenase leakage. These results explain the detailed mechanism of different diameters of small Fe3O4 NPs-induced cytotoxicity. We anticipate that this study will provide different insights into the cytotoxicity mechanism of Fe3O4 NPs, so as to make them safer to use in clinical application. PMID:27536098

  19. Leucocyte cellular adhesion molecules.

    PubMed

    Yong, K; Khwaja, A

    1990-12-01

    Leucocytes express adhesion promoting receptors which mediate cell-cell and cell-matrix interactions. These adhesive interactions are crucial to the regulation of haemopoiesis and thymocyte maturation, the direction and control of leucocyte traffic and migration through tissues, and in the development of immune and non-immune inflammatory responses. Several families of adhesion receptors have been identified (Table). The leucocyte integrin family comprises 3 alpha beta heterodimeric membrane glycoproteins which share a common beta subunit, designated CD18. The alpha subunits of each of the 3 members, lymphocyte function associated antigen-1 (LFA-1), macrophage antigen-1 (Mac-1) and p150,95 are designated CD11a, b and c respectively. These adhesion molecules play a critical part in the immune and inflammatory responses of leucocytes. The leucocyte integrin family is, in turn, part of the integrin superfamily, members of which are evolutionally, structurally and functionally related. Another Integrin subfamily found on leucocytes is the VLA group, so-called because the 'very late activation antigens' VLA-1 and VLA-2 were originally found to appear late in T-cell activation. Members of this family function mainly as extracellular matrix adhesion receptors and are found both on haemopoietic and non-haemopoietic cells. They play a part in diverse cellular functions including tissue organisation, lymphocyte recirculation and T-cell immune responses. A third integrin subfamily, the cytoadhesins, are receptors on platelets and endothelial cells which bind extracellular matrix proteins. A second family of adhesion receptors is the immunoglobulin superfamily, members of which include CD2, LFA-3 and ICAM-1, which participate in T-cell adhesive interactions, and the antigen-specific receptors of T and B cells, CD4, CD8 and the MHC Class I and II molecules. A recently recognised family of adhesion receptors is the selectins, characterised by a common lectin domain. Leucocyte

  20. Keynote address: cellular reduction of nitroimidazole drugs: potential for selective chemotherapy and diagnosis of hypoxic cells.

    PubMed

    Chapman, J D; Lee, J; Meeker, B E

    1989-04-01

    Nitroimidazole drugs were initially developed as selective radiosensitizers of hypoxic cells and, consequently, as adjuvants to improve the local control probabilities of current radiotherapies. Misonidazole (MISO), the prototype radiosensitizing drug, was found in Phase I clinical studies to cause dose-limiting neurotoxicities (mainly peripheral neuropathies). MISO was also found to be cytotoxic in the absence of radiation and to covalently bind to cellular molecules, both processes demonstrating rates much higher in hypoxic compared with oxygenated cells. It is likely that neurotoxicity, cellular cytotoxicity and adduct formation results from reactions between reduction intermediates of MISO and cellular target molecules. Spin-offs from radiosensitizer research include the synthesis and characterization of more potent hypoxic cytotoxins and the exploitation of sensitizer-adducts as probes for measuring cellular and tissue oxygen levels. Current developments in hypoxic cell cytotoxin and hypoxic cell marker research are reviewed with specific examples from studies which characterize the cellular reduction of TF-MISO, (1-(2-nitro-1-imidazolyl)-3[2,2,2-trifluoroethoxy]-2-propanol). PMID:2649465

  1. The design of redox active thiol peroxidase mimics: Dihydrolipoic acid recognition correlates with cytotoxicity and prooxidant action.

    PubMed

    Zadehvakili, B; McNeill, S M; Fawcett, J P; Giles, G I

    2016-03-15

    Redox active molecules containing organoselenium or organotellurium groups catalyse the oxidation of cellular thiols by hydrogen peroxide and are currently being developed as therapeutic agents. Potentially these synthetic thiol peroxidase (TPx) mimics can protect cells from oxidative stress by catalysing the reduction of reactive oxygen species by the cellular thiol glutathione, an activity which mimics the function of the antioxidant enzyme glutathione peroxidase. Alternatively they can act as prooxidants by catalysing the oxidation of essential thiol species within the cell. However the structure-activity relationships which determine the choice of thiol substrate, and hence the overall antioxidant or prooxidant outcome of drug administration, remain unknown. We report the first study that relates the pharmacological properties of TPx mimics with their solubility and catalytic activity using different thiol substrates. We used a series of structurally related compounds PhMCnH2n+1 (M=Se, Te; n=4-7) and investigated their ability to catalyse the oxidation of the cellular thiols glutathione and dihydrolipoic acid by hydrogen peroxide. The resulting rate constants (kobs) were then related to compound cytotoxicity and antioxidant versus prooxidant action in A549 cancer cells. The results show that the dihydrolipoic acid kobs values correlate with both cytotoxicity and prooxidant function. This enabled us to define a relationship, IC50=10+280e(-5(DHLA) (kobs)), which allows the prediction of TPx mimic cytotoxicity. In contrast, hydrophobicity and glutathione kobs were unrelated to the compounds' redox pharmacology. PMID:26801688

  2. Cytotoxicity of electrophilic iron(II)-clathrochelates in human promyelocytic leukemia cell line.

    PubMed

    Blechinger, Jenny; Varzackii, Oleg A; Kovalska, Vladyslava; Zelinskii, Genrikh E; Voloshin, Yan Z; Kinski, Elisa; Mokhir, Andriy

    2016-01-15

    We observed that electrophilic iron(II)-clathrochelates exhibit significant cytotoxicity in human promyelocytic leukemia cells (IC50=6.5±4.6μM), which correlates with the enhancement of intracellular oxidative stress (17-fold increase with respect to the cells treated with the solvent only). Based on in vitro studies we suggested that this effect is caused by alkylation of glutathione leading to inhibition of the cellular antioxidative system and by catalytic generation of reactive oxygen species by products of the alkylation reaction. PMID:26631314

  3. Resistance to Degradation and Cellular Distribution are Important Features for the Antitumor Activity of Gomesin

    PubMed Central

    Buri, Marcus V.; Domingues, Tatiana M.; Paredes-Gamero, Edgar J.; Casaes-Rodrigues, Rafael L.; Rodrigues, Elaine Guadelupe; Miranda, Antonio

    2013-01-01

    Many reports have shown that antimicrobial peptides exhibit anticancer abilities. Gomesin (Gm) exhibits potent cytotoxic activity against cancer cells by a membrane pore formation induced after well-orchestrated intracellular mechanisms. In this report, the replacements of the Cys by Ser or Thr, and the use D-amino acids in the Gm structure were done to investigate the importance of the resistance to degradation of the molecule with its cytotoxicity. [Thr2,6,11,15]-Gm, and [Ser2,6,11,15]-Gm exhibits low cytotoxicity, and low resistance to degradation, and after 24 h are present in localized area near to the membrane. Conversely, the use of D-amino acids in the analogue [D-Thr2,6,11,15]-D-Gm confers resistance to degradation, increases its potency, and maintained this peptide spread in the cytosol similarly to what happens with Gm. Replacements of Cys by Thr and Gln by L- or D-Pro ([D-Thr2,6,11,15, Pro9]-D-Gm, and [Thr2,6,11,15, D-Pro9]-Gm), which induced a similar β-hairpin conformation, also increase their resistance to degradation, and cytotoxicity, but after 24 h they are not present spread in the cytosol, exhibiting lower cytotoxicity in comparison to Gm. Additionally, chloroquine, a lysosomal enzyme inhibitor potentiated the effect of the peptides. Furthermore, the binding and internalization of peptides was determined, but a direct correlation among these factors was not observed. However, cholesterol ablation, which increase fluidity of cellular membrane, also increase cytotoxicity and internalization of peptides. β-hairpin spatial conformation, and intracellular localization/target, and the capability of entry are important properties of gomesin cytotoxicity. PMID:24312251

  4. Gold Nanoparticles Inhibit Matrix Metalloproteases without Cytotoxicity.

    PubMed

    Hashimoto, M; Sasaki, J I; Yamaguchi, S; Kawai, K; Kawakami, H; Iwasaki, Y; Imazato, S

    2015-08-01

    Nanoparticles (NPs) are currently the focus of considerable attention for dental applications; however, their biological effects have not been fully elucidated. The long-term, slow release of matrix metalloproteases (MMPs) digests collagen fibrils within resin-dentin bonds. Therefore, MMP inhibitors can prolong the durability of resin-dentin bonds. However, there have been few reports evaluating the combined effect of MMP inhibition and the cytotoxic effects of NPs for dentin bonding. The aim of this study was to evaluate MMP inhibition and cytotoxic responses to gold (AuNPs) and platinum nanoparticles (PtNPs) stabilized by polyvinylpyrrolidone (PVP) in cultured murine macrophages (RAW264) by using MMP inhibition assays, measuring cell viability and inflammatory responses (quantitative reverse transcription polymerase chain reaction [RT-qPCR]), and conducting a micromorphological analysis by fluorescence and transmission electron microscopy. Cultured RAW264 cells were exposed to metal NPs at various concentrations (1, 10, 100, and 400 µg/mL). AuNPs and PtNPs markedly inhibited MMP-8 and MMP-9 activity. Although PtNPs were cytotoxic at high concentrations (100 and 400 µg/mL), no cytotoxic effects were observed for AuNPs at any concentration. Transmission electron microscopy images showed a significant nonrandom intercellular distribution for AuNPs and PtNPs, which were mostly observed to be localized in lysosomes but not in the nucleus. RT-qPCR analysis demonstrated inflammatory responses were not induced in RAW264 cells by AuNPs or PtNPs. The cytotoxicity of nanoparticles might depend on the core metal composition and arise from a "Trojan horse" effect; thus, MMP inhibition could be attributed to the surface charge of PVP, which forms the outer coating of NPs. The negative charge of the surface coating of PVP binds to Zn(2+) from the active center of MMPs by chelate binding and results in MMP inhibition. In summary, AuNPs are attractive NPs that effectively

  5. Cellular compartmentalization of secondary metabolism

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fungal secondary metabolism is often considered apart from the essential housekeeping functions of the cell. However, there are clear links between fundamental cellular metabolism and the biochemical pathways leading to secondary metabolite synthesis. Besides utilizing key biochemical precursors sh...

  6. Cellular therapy for haematological malignancies.

    PubMed

    Roddie, P H; Turner, M L

    2002-11-01

    The aim of this review was to summarize the recent progress made in the field of cellular therapeutics in haematological malignancy. The review also examined the role that the National Transfusion Services might play in the manufacture of new cellular therapeutic agents, given both their expertise in the safe provision of blood products and their possession of accredited cell manipulation facilities. Cellular therapy is entering an era in which novel cellular products will find increasing clinical use, particularly in the areas of haematopoietic stem cell transplantation and immunotherapy. The production of novel cell-based therapies, both in Europe and North America, is now under strict regulatory control and therefore collaboration with the National Transfusion Services in the manufacture of these agents may well be beneficial if the production standards demanded by the regulatory authorities are to be fulfilled. PMID:12437515

  7. Recombinant lipoproteins reinforce cytotoxicity of doxorubicin to hepatocellular carcinoma.

    PubMed

    Wang, Baolong; Yuan, Yuan; Han, Lei; Ye, Li; Shi, Xunlong; Feng, Meiqing

    2014-01-01

    Cancer nanotherapeutics are changing the landscape of tumor treatment and used to circumvent limitations of conventional chemotherapy, such as non-specificity and low bioavailability. Reconstituted high density lipoproteins (rHDL) system is one of the most promising targeting delivery systems of chemotherapeutic drugs toward tumors. Here, we developed recombined high-density lipoprotein which can be functionalized to deliver doxorubicin intracellular with a higher efficiency. The cellular viability assay showed that the rHDL/Dox nanovectors had an enhanced efficiency in inhibiting the cell viability of hepatocellular carcinoma cell lines HepG2 and SMMC-7721. FACS and confocal microscopy was used to observe the doxorubicin delivery into cancer cells. Intracellular drug accumulation analysis confirmed that treatment of rHDL/Dox nanovectors resulted in higher intracellular doxorubicin concentration to the levels exceeding that of free drug. On the premise of efficient drug delivery, rHDL/Dox nanovectors have been preliminarily demonstrated effective inducing of cytotoxic effect and cell apoptosis to both of the cell lines in vitro. Tissue distribution experiment showed that rHDL/Dox nanovectors could also deliver doxorubicin to liver effectively. So, we proposed that this lipoprotein-based strategy holds promise for a safer and more efficient delivery of chemotherapeutic agents in the treatment of hepatocellular carcinoma. PMID:24093636

  8. Cytotoxicity assessment of porous silicon microparticles for ocular drug delivery.

    PubMed

    Korhonen, Eveliina; Rönkkö, Seppo; Hillebrand, Satu; Riikonen, Joakim; Xu, Wujun; Järvinen, Kristiina; Lehto, Vesa-Pekka; Kauppinen, Anu

    2016-03-01

    Porous silicon (PSi) is a promising material for the delivery and sustained release of therapeutic molecules in various tissues. Due to the constant rinsing of cornea by tear solution as well as the short half-life of intravitreal drugs, the eye is an attractive target for controlled drug delivery systems, such as PSi microparticles. Inherent barriers ensure that PSi particles are retained in the eye, releasing drugs at the desired speed until they slowly break down into harmless silicic acid. Here, we have examined the in vitro cytotoxicity of positively and negatively charged thermally oxidized (TOPSi) and thermally carbonized (TCPSi) porous silicon microparticles on human corneal epithelial (HCE) and retinal pigment epithelial (ARPE-19) cells. In addition to ocular assessment under an inverted microscope, cellular viability was evaluated using the CellTiter Blue™, CellTiter Fluor™, and lactate dehydrogenase (LDH) assays. CellTiter Fluor proved to be a suitable assay but due to non-specific and interfering responses, neither CellTiter Blue nor LDH assays should be used when evaluating PSi particles. Our results suggest that the toxicity of PSi particles is concentration-dependent, but at least at concentrations less than 200μg/ml, both positively and negatively charged PSi particles are well tolerated by human corneal and retinal epithelial cells and therefore applicable for delivering drug molecules into ocular tissues. PMID:26686646

  9. In vitro evaluation of corrosion and cytotoxicity of orthodontic brackets.

    PubMed

    Costa, M T; Lenza, M A; Gosch, C S; Costa, I; Ribeiro-Dias, F

    2007-05-01

    The corrosion resistance of AISI 304 stainless steel (AISI 304 SS) and manganese stainless steel (low-nickel SS) brackets in artificial saliva was investigated. The cytotoxic effects of their corrosion products on L929 cell culture were compared by two assays, crystal violet, to evaluate cell viability, and MTT (3-[4,5-dimethylthiazol-2-yl]2,5-diphenyltetrazolium bromide), for cell metabolism and proliferation. The atomic absorption spectroscopic analysis of the corrosion products demonstrated that nickel and manganese ion concentrations were higher for the AISI 304 SS-bracket immersion solution as compared with the low-nickel SS brackets. Scanning electron microscopy and energy-dispersive spectroscopy demonstrated less corrosion resistance for the AISI 304 SS brackets. Although none of the bracket extracts altered L929 cell viability or morphology, the AISI 304 SS-bracket extracts decreased cellular metabolism slightly. The results indicated that the low-nickel SS presents better in vitro biocompatibility than AISI 304 SS brackets. Abbreviations used: AISI, American Iron and Steel Institute; EDS, energy-dispersive spectroscopy; OD, optical density; ISO, International Organization for Standardization; MTT, (3-{4,5 dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; NiSO(4), nickel sulfate; SEM, standard error of the mean; WHO, World Health Organization; and TNF, tumor necrosis factor. PMID:17452565

  10. Characterization of crude Echis carinatus venom-induced cytotoxicity in HEK 293T cells

    PubMed Central

    Pierce, Rebecca D; Kim, Ethan S; Girton, Lance W; McMurry, Jonathan L; Francis, Joshua W; Albrecht, Eric A

    2011-01-01

    Echis carinatus (saw-scaled viper) produces potent hemorrhagic venom that causes the development of apoptotic and necrotic tissues. In this study, we used polyethyleneimine (PEI) to enhance cellular adherence, and to determine whether the substrate attachment influenced the survival of cells treated with crude E. carinatus venom. Human embryonic kidney (HEK) 293T cells were grown for 18hr in tissue culture plates with or without polyethyleneimine (PEI), and were then stimulated with crude E. carinatus venom for 3 or 12hr. HEK 293T cells grown without PEI displayed a robust oxidative response to corresponding substrate detachment, loss of plasma membrane integrity and decreased cell viability. Cells grown on PEI adsorbed substrates demonstrated prolonged substrate attachment resulting in significantly higher cell viabilities. These observations suggest that the cytotoxicity of crude E. carinatus venom is dependent upon cellular detachment. PMID:22331993

  11. Characterization of crude Echis carinatus venom-induced cytotoxicity in HEK 293T cells.

    PubMed

    Pierce, Rebecca D; Kim, Ethan S; Girton, Lance W; McMurry, Jonathan L; Francis, Joshua W; Albrecht, Eric A

    2011-01-01

    Echis carinatus (saw-scaled viper) produces potent hemorrhagic venom that causes the development of apoptotic and necrotic tissues. In this study, we used polyethyleneimine (PEI) to enhance cellular adherence, and to determine whether the substrate attachment influenced the survival of cells treated with crude E. carinatus venom. Human embryonic kidney (HEK) 293T cells were grown for 18hr in tissue culture plates with or without polyethyleneimine (PEI), and were then stimulated with crude E. carinatus venom for 3 or 12hr. HEK 293T cells grown without PEI displayed a robust oxidative response to corresponding substrate detachment, loss of plasma membrane integrity and decreased cell viability. Cells grown on PEI adsorbed substrates demonstrated prolonged substrate attachment resulting in significantly higher cell viabilities. These observations suggest that the cytotoxicity of crude E. carinatus venom is dependent upon cellular detachment. PMID:22331993

  12. Mathematical Modeling of Cellular Metabolism.

    PubMed

    Berndt, Nikolaus; Holzhütter, Hermann-Georg

    2016-01-01

    Cellular metabolism basically consists of the conversion of chemical compounds taken up from the extracellular environment into energy (conserved in energy-rich bonds of organic phosphates) and a wide array of organic molecules serving as catalysts (enzymes), information carriers (nucleic acids), and building blocks for cellular structures such as membranes or ribosomes. Metabolic modeling aims at the construction of mathematical representations of the cellular metabolism that can be used to calculate the concentration of cellular molecules and the rates of their mutual chemical interconversion in response to varying external conditions as, for example, hormonal stimuli or supply of essential nutrients. Based on such calculations, it is possible to quantify complex cellular functions as cellular growth, detoxification of drugs and xenobiotic compounds or synthesis of exported molecules. Depending on the specific questions to metabolism addressed, the methodological expertise of the researcher, and available experimental information, different conceptual frameworks have been established, allowing the usage of computational methods to condense experimental information from various layers of organization into (self-) consistent models. Here, we briefly outline the main conceptual frameworks that are currently exploited in metabolism research. PMID:27557541

  13. Cellular uptake and covalent binding of nitroso-chloramphenicol

    SciTech Connect

    Murray, T.; Yunis, A.A.

    1981-09-01

    A comparative study of the cellular transport of CAP and its nitroso derivative (NO-CAP) was carried out in Raji cells, a transformed human lymphoblastoid cell line. Both agents were concentrated by the cells by a factor of 3 (cellular/extracellular concentration ratio). The cellular uptake of NO-CAP, like that of CAP, was found to be rapid and temperature-independent. Thus the greater cytotoxicity of NO-CAP is apparently not due to an enhanced uptake of the nitroso derivative relative to CAP. In contrast to the similarity of uptake, NO-CAP becomes covalently bound to both Raji cells and freshly isolated human bone marrow cells to a much higher extent (15-fold). Also, cells previously loaded with CAP or NO-CAP retain three times as much of the nitroso compound during a 24 hr dialysis against a drug-free isotonic solution. The increased binding of NO-CAP to human hematopoietic cells attests to the greater reactivity of the p-substituted aromatic nitroso group and is consistent with the postulate that reduction products of the nitro group of CAP may be responsible for CAP-induced aplastic anemia.

  14. Asplatin enhances drug efficacy by altering the cellular response.

    PubMed

    Cheng, Qinqin; Shi, Hongdong; Wang, Hongxia; Wang, Jun; Liu, Yangzhong

    2016-07-13

    Aspirin, a widely used anti-inflammatory drug, has been shown to be effective for the prevention and remission of cancers (Science, 2012, 337(21) 1471-1473). Asplatin, a Pt(iv) prodrug of cisplatin with the ligation of aspirin (c,c,t-[PtCl2(NH3)2(OH)(aspirin)]), demonstrates significantly higher cytotoxicity than cisplatin towards tumor cells and almost fully overcomes the drug resistance of cisplatin resistant cells. In this work, we have studied the molecular mechanism of asplatin by investigating the cellular response to this compound in order to understand the prominent inhibitory effect on the proliferation of cancer cells. The apoptosis analyses and the related gene expression measurements show that aspirin released from asplatin significantly modulates the cellular response to the platinum agent. Asplatin promotes the apoptosis via the BCL-2 associated mitochondrial pathway. The down-regulation of BCL-2 along with the up-regulation of BAX and BAK enhances the mitochondrial outer membrane permeability, resulting in the cytochrome c release from mitochondria into the cytosol. This event promotes the apoptosis by activation of caspase processing. Consequently, the ligation of aspirin significantly enhances the drug efficacy of the platinum complex in the low micromolar range. The alteration of the cellular response is probably responsible for the circumvention of the cisplatin resistance by asplatin. These results provide an insight into the mechanism of asplatin and provide information for designing new classic platinum drugs. PMID:27125788

  15. In Vivo Cellular Imaging for Translational Medical Research

    PubMed Central

    Arbab, Ali S; Janic, Branislava; Haller, Jodi; Pawelczyk, Edyta; Liu, Wei; Frank, Joseph A

    2009-01-01

    Personalized treatment using stem, modified or genetically engineered, cells is becoming a reality in the field of medicine, in which allogenic or autologous cells can be used for treatment and possibly for early diagnosis of diseases. Hematopoietic, stromal and organ specific stem cells are under evaluation for cell-based therapies for cardiac, neurological, autoimmune and other disorders. Cytotoxic or genetically altered T-cells are under clinical trial for the treatment of hematopoietic or other malignant diseases. Before using stem cells in clinical trials, translational research in experimental animal models are essential, with a critical emphasis on developing noninvasive methods for tracking the temporal and spatial homing of these cells to target tissues. Moreover, it is necessary to determine the transplanted cell’s engraftment efficiency and functional capability. Various in vivo imaging modalities are in use to track the movement and incorporation of administered cells. Tagging cells with reporter genes, fluorescent dyes or different contrast agents transforms them into cellular probes or imaging agents. Recent reports have shown that magnetically labeled cells can be used as cellular magnetic resonance imaging (MRI) probes, demonstrating the cell trafficking to target tissues. In this review, we will discuss the methods to transform cells into probes for in vivo imaging, along with their advantages and disadvantages as well as the future clinical applicability of cellular imaging method and corresponding imaging modality. PMID:19768136

  16. Cytotoxic activity of selected Nigerian plants.

    PubMed

    Sowemimo, A; van de Venter, M; Baatjies, L; Koekemoer, T

    2009-01-01

    Cancer is one of the most prominent human diseases which has stimulated scientific and commercial interest in the discovery of new anticancer agents from natural sources. The current study investigates the cytotoxic activity of ethanolic extracts of sixteen Nigerian plants used locally for the treatment of cancer using the MTT assay on the HeLa cell line. Sapium ellipticum leaves showed activity comparable to the reference compound Cisplatin and greater cytotoxic activity than Combretum paniculatum, Celosia trigyna, Drymaria cordata, Cyathula achyranthoides and Cyathula prostata. Justica extensa, Pupalia lappacea, Hedranthera barteri leaves, Alternanthera sessilis, Ethulia conyzoides leaves, Combretum zenkeri root, Sapium ellipticum stembark and Lannea nigritana stembark showed very low activity while Combretum molle, Adenanthera parvoniana and Lannea acida showed no activity. The results justify the use of Sapium, Combretum, Celosia, Drymaria and Cyathula in traditional treatment of cancer. PMID:20606772

  17. Cytotoxic diterpenoids from Rabdosia lophanthoides var. gerardianus.

    PubMed

    Lin, Chao-Zhan; Zhao, Wei; Feng, Xiu-Li; Liu, Fang-Le; Zhu, Chen-Chen

    2016-03-01

    Two new abietane diterpenoids, Gerardianin B (1) and Gerardianin C (2), one new lignan glycoside, Gerardianin D (3) and one new lupane-type triterpenoid, Gerardianol A (4), together with seven known abietane diterpenoids were isolated from the aerial parts of Rabdosia lophanthoides var. gerardianus. Their structures were determined by 1D and 2D NMR spectroscopic data. The cytotoxic activities of the nine diterpenoids were evaluated on human cancer cell lines. Compounds 6-11 exhibited significant cytotoxic activities against HepG2 cell lines with IC50 from 4.68 to 9.43μM and HCF-8 cell lines with IC50 from 9.12 to 13.53μM. PMID:26608401

  18. Cytotoxic steroidal saponins from Agave sisalana.

    PubMed

    Chen, Pi-Yu; Chen, Chin-Hui; Kuo, Ching-Chuan; Lee, Tzong-Huei; Kuo, Yueh-Hsiung; Lee, Ching-Kuo

    2011-06-01

    Two new steroidal saponins, 8 and 10, along with 7 known steroidal sapogenins and saponins (1-7) and a furostanol saponin (9) were isolated from Agave sisalana Perrine ex Engelm. The structures of these two new compounds were identified and characterized by 1D and 2D NMR spectroscopy and mass spectrometry. In addition, acid hydrolysis and GC-FID were used to confirm the sugar moieties of 8 and 10. The cytotoxic effects of 1-10 on MCF-7, NCI-H460, and SF-268 cancer cells were evaluated, and among them, compound 10 proved to be the most cytotoxic with IC₅₀ values of 1.2, 3.8, and 1.5 µM, respectively. PMID:21243587

  19. Cytotoxic activity of Vitex trifolia purpurea extracts.

    PubMed

    El-Sayed, Mortada M; El-Hashash, Maher M; Mohamed, Mona A; Korany, Tamer M

    2011-08-01

    Defatted 85% crude hot aqueous methanol extract of Vitex trifolia purpurea (AME) successively extracted with, chloroform and ethyl acetate. Cytotoxicity of (AME), chloroform methanol extract (CE), ethyl acetate methanol extract (EE) and the residue obtained from methanol extract after successive extraction (RME) have been evaluated on brine shrimp (Artemia salina) and Hep-G2 cell lines as well. In brine shrimp lethality bioassay the results revealed that the (RME) is the most potent one with LC50 value 173 microg/ml while LC50 values of (AME), (CE) and (EE) was 180, 199 and 286 microg/ml, respectively. As well as the results of cytotoxic assay against Hep-G2 cell lines are in full agreement with previous results, with IC50 values 6, 10.7, 20.8 and 65.8 microg/ml for (RME), (AME), (CE) and (EE), respectively. PMID:21980779

  20. Cytotoxic farnesyl glycosides from Pittosporum pancheri.

    PubMed

    Eparvier, Véronique; Thoison, Odile; Bousserouel, Hadjira; Guéritte, Françoise; Sévenet, Thierry; Litaudon, Marc

    2007-03-01

    Bioassay guided purification of the ethanolic extract of the bark of New Caledonian Pittosporum pancheri Brongn. and Gris (Pittosporaceae) led to the isolation and characterization of two new farnesyl monoglycosides, pancherins A and B. The structure of these compounds were determined on the basis of spectroscopic studies. The new compounds displayed a significant activity in the in vitro cytotoxic assay against KB cancer cell line, and pancherin A inhibits weakly farnesyl protein transferase. PMID:17174992

  1. Four new cytotoxic xanthones from Garcinia nujiangensis.

    PubMed

    Tang, Zhong-Yan; Xia, Zheng-Xiang; Qiao, Shi-Ping; Jiang, Chao; Shen, Guo-Rong; Cai, Mei-Xiang; Tang, Xiao-Yan

    2015-04-01

    Bioassay-guided fractionation of the acetone extract of the twigs of Garcinia nujiangensis resulted in the isolation of four new prenylated xanthones, nujiangexanthones C-F (1-4), and ten known related analogues. The structures of compounds 1-4 were elucidated by interpretation of their spectroscopic data. The compounds isolated were evaluated for their cytotoxic effects against three cancer cell lines, the test substances demonstrated selectivity toward the cancer cells. PMID:25727735

  2. Cytotoxicity screening of some South American Solanaceae.

    PubMed

    Moreno-Murillo, B; Fajardo, V M; Suárez, M

    2001-08-01

    Alcoholic extracts of seven plants belonging to the Solanaceae family were phytochemically screened and evaluated for their cytotoxic activity by Brine Shrimp Test (BST) with Artemia salina larvae, Inhibition of Cell Division Test (ICDT) on sea urchin Loxechinus albus fertilized eggs and inhibition of crown gall tumors on Potato Disk Bioassay (PDB). From Salpichroa diffusa, bioassay-guided chromatographic separation afforded some active fractions from which epi-katonic acid was identified. PMID:11543969

  3. Synthesis and cytotoxic activity of acetogenin analogues.

    PubMed

    Rodier, S; Le Huérou, Y; Renoux, B; Doyon, J; Renard, P; Pierré, A; Gesson, J P; Grée, R

    2000-06-19

    A set of 16 new simplified analogues of acetogenins has been designed based on: (i) the replacement of the bis THF moiety of these natural products by an ethylene glycol bis ether unit; (ii) the introduction of different lipophilic side chains (alkyl, aryl, dialkylamino, O-cholesteryl); (iii) the presence of the same terminal isolactone. In vitro cytotoxic activity against L1210 leukemia is reported. PMID:10890167

  4. Mycoplasma pneumoniae induces cytotoxic activity in guinea pig bronchoalveolar cells

    SciTech Connect

    Kist, M.; Koester, H.; Bredt, W.

    1985-06-01

    Precultured guinea pig alveolar macrophages (AM) and freshly harvested alveolar cells (FHAC) activated by interaction with Mycoplasma pneumoniae were cytotoxic for xenogeneic /sup 75/selenomethionine-labeled tumor target cells. Phagocytosis of whole opsonized or nonopsonized M. pneumoniae cells was more effective in eliciting cytotoxicity than uptake of sonicated microorganisms. The addition of living mycoplasma cells to the assay system enhanced the cytotoxic effect considerably. Target cells were significantly more susceptible to the cytotoxic action of phagocytes if they were coated with mycoplasma antigen or cocultured together with M. pneumoniae. The activation of the phagocytes could be inhibited by 2-deoxy-D-glucose but not by antimicrobial substances suppressing mycoplasma protein synthesis. It was accompanied by /sup 51/Cr release without detectable signs of cell damage. The supernatants of activated cells were cytotoxic for approximately 24 h. Inhibition, release, and cytotoxic activity indicate the necessity of an intact metabolism of the effector cells and suggest a secretion of cytotoxic substances.

  5. Initial cytotoxicity of novel titanium alloys.

    PubMed

    Koike, M; Lockwood, P E; Wataha, J C; Okabe, T

    2007-11-01

    We assessed the biological response to several novel titanium alloys that have promising physical properties for biomedical applications. Four commercial titanium alloys [Super-TIX(R) 800, Super-TIX(R) 51AF, TIMETAL(R) 21SRx, and Ti-6Al-4V (ASTM grade 5)] and three experimental titanium alloys [Ti-13Cr-3Cu, Ti-1.5Si and Ti-1.5Si-5Cu] were tested. Specimens (n = 6; 5.0 x 5.0 x 3.0 mm(3)) were cast in a centrifugal casting machine using a MgO-based investment and polished to 600 grit, removing 250 mum from each surface. Commercially pure titanium (CP Ti: ASTM grade 2) and Teflon (polytetrafluoroethylene) were used as positive controls. The specimens were cleaned and disinfected, and then each cleaned specimen was placed in direct contact with Balb/c 3T3 fibroblasts for 72 h. The cytotoxicity [succinic dehydrogenase (SDH) activity] of the extracts was assessed using the MTT method. Cytotoxicity of the metals tested was not statistically different compared to the CP Ti and Teflon controls (p > 0.05). These novel titanium alloys pose cytotoxic risks no greater than many other commonly used alloys, including commercially pure titanium. The promising short-term biocompatibility of these Ti alloys is probably due to their excellent corrosion resistance under static conditions, even in biological environments. PMID:17385227

  6. Iron oxide nanoparticle enhancement of radiation cytotoxicity

    NASA Astrophysics Data System (ADS)

    Mazur, Courtney M.; Tate, Jennifer A.; Strawbridge, Rendall R.; Gladstone, David J.; Hoopes, P. Jack

    2013-02-01

    Iron oxide nanoparticles (IONPs) have been investigated as a promising means for inducing tumor cell-specific hyperthermia. Although the ability to generate and use nanoparticles that are biocompatible, tumor specific, and have the ability to produce adequate cytotoxic heat is very promising, significant preclinical and clinical development will be required for clinical efficacy. At this time it appears using IONP-induced hyperthermia as an adjunct to conventional cancer therapeutics, rather than as an independent treatment, will provide the initial IONP clinical treatment. Due to their high-Z characteristics, another option is to use intracellular IONPs to enhance radiation therapy without excitation with AMF (production of heat). To test this concept IONPs were added to cell culture media at a concentration of 0.2 mg Fe/mL and incubated with murine breast adenocarcinoma (MTG-B) cells for either 48 or 72 hours. Extracellular iron was then removed and all cells were irradiated at 4 Gy. Although samples incubated with IONPs for 48 hrs did not demonstrate enhanced post-irradiation cytotoxicity as compared to the non-IONP-containing cells, cells incubated with IONPs for 72 hours, which contained 40% more Fe than 48 hr incubated cells, showed a 25% decrease in clonogenic survival compared to their non-IONP-containing counterparts. These results suggest that a critical concentration of intracellular IONPs is necessary for enhancing radiation cytotoxicity.

  7. Mutagenic and cytotoxic activities of benfuracarb insecticide.

    PubMed

    Eren, Yasin; Erdoğmuş, Sevim Feyza; Akyıl, Dilek; Özkara, Arzu

    2016-08-01

    Benfuracarb is a carbamate insecticide used to control insect pests in vegetables and it has anti-acetylcholinesterase activity lower than other carbamates. Cytotoxic effects of benfuracarb were evaluated by using root growth inhibition (EC50), mitotic index (MI), and mitotic phase determinations on the root meristem cells of Allium cepa and mutagenic effects were determined in Salmonella typhymurium Ames test by TA98 and TA100 strains with and without metabolic activation. In Allium test, 1 % DMSO was used as negative control group and 10 ppm MMS was used as positive control group. 75 ppm concentration of benfuracarb was found as EC50. In MI and mitotic phases determination study, 37.5, 75 and 150 ppm doses of benfuracarb were used. Dose-dependent cytotoxic activity was found by root growth inhibition and MI studies. It was identified that mitotic inhibition activity of benfuracarb was higher than 10 ppm MMS. In Ames test, mutagenic activity was not observed and over 200 µg/plate of benfuracarb was determined as cytotoxic to S. typhymurium strains. Benfuracarb can be called as "mitotic inhibitor" but not called as mutagen. PMID:25381170

  8. Propolis Varnish: Antimicrobial Properties against Cariogenic Bacteria, Cytotoxicity, and Sustained-Release Profile

    PubMed Central

    De Luca, Mariana P.; Franca, Juçara R.; Macedo, Filipe Augusto F. F.; Cortes, Maria Esperanza; Faraco, André Augusto G.; Moreira, Allyson N.; Santos, Vagner R.

    2014-01-01

    Varnishes are preparations that differ in the polymeric matrix and therapeutical agents. In dentistry they are used to prevent caries. In this study we developed a propolis varnish, considering propolis properties against cariogenic bacteria. To a chitosan polymeric base (CHV) was added ethanolic propolis extract in different concentrations: PV1 (5%), PV2 (10%), and PV3 (15%). Antimicrobial activity was carried out against Streptococcus mutans (SM), Streptococcus sanguinis (SG), Streptococcus salivarius (SS), and Lactobacillus casei (LC) through agar diffusion method. The three propolis concentrations incorporated were effective in inhibiting the growth of all microorganisms, but without significant difference between the zones of inhibition observed. Cytotoxicity assay was done by MTT method. Data were analyzed by one-way ANOVA and Bonferroni test. None of the varnishes were cytotoxic, keeping 80% of viable cells, while CHV allowed cellular proliferation (120%). Sustained-release test was carried out by applying 40 μL of each varnish in the buccal surface of bovine teeth and kept in an ethanol/water solution removed in regular times. According to the “independent model approach,” the release profiles were distinct from each varnish and the most prolonged was PV3 (8 weeks). Varnish formulations had satisfactory antimicrobial activity against cariogenic bacteria and have a low cytotoxicity (<50%). PMID:24949436

  9. Cytotoxic Helix-Rich Oligomer Formation by Melittin and Pancreatic Polypeptide

    PubMed Central

    Singh, Pradeep K.; Ghosh, Dhiman; Tewari, Debanjan; Mohite, Ganesh M.; Carvalho, Edmund; Jha, Narendra Nath; Jacob, Reeba S.; Sahay, Shruti; Banerjee, Rinti; Bera, Amal K.; Maji, Samir K.

    2015-01-01

    Conversion of amyloid fibrils by many peptides/proteins involves cytotoxic helix-rich oligomers. However, their toxicity and biophysical studies remain largely unknown due to their highly dynamic nature. To address this, we chose two helical peptides (melittin, Mel and pancreatic polypeptide, PP) and studied their aggregation and toxicity. Mel converted its random coil structure to oligomeric helical structure upon binding to heparin; however, PP remained as helix after oligomerization. Interestingly, similar to Parkinson’s associated α-synuclein (AS) oligomers, Mel and PP also showed tinctorial properties, higher hydrophobic surface exposure, cellular toxicity and membrane pore formation after oligomerization in the presence of heparin. We suggest that helix-rich oligomers with exposed hydrophobic surface are highly cytotoxic to cells irrespective of their disease association. Moreover as Mel and PP (in the presence of heparin) instantly self-assemble into stable helix-rich amyloidogenic oligomers; they could be represented as models for understanding the biophysical and cytotoxic properties of helix-rich intermediates in detail. PMID:25803428

  10. Cytotoxicity and reactive oxygen species generation from aggregated carbon and carbonaceous nanoparticulate materials.

    PubMed

    Garza, Kristine M; Soto, Karla F; Murr, Lawrence E

    2008-01-01

    We have investigated the cytotoxicity and reactive oxygen species (ROS) generation for indoor and outdoor soots: candle, wood, diesel, tire, and natural gas burner soots--along with surrogate black carbon, various multiwall carbon nanotube aggregate materials, TiO2 (anatase) and chrysotile asbestos as reference materials. All soots were observed utilizing TEM and FESEM to be composed of aggregated, primary spherules (20-80 nm diameter) forming complex, branched fractal structures. These spherules were composed of intercalated, turbostratic arrangements of curved graphene fragments with varying concentrations ofpolycyclic aromatic hydrocarbon (PAH) isomers. In vitro cultures with an immortalized human lung epithelial carcinoma cell line (A549) treated with these materials showed decreased cell viability and variations in ROS production, with no correlations to PAH content. The data demonstrate that soots are cytotoxic and that cytotoxicity is not related to PAH content but is related to ROS generation, suggesting that soot induces cellular oxidative stress and that cell viability assays can be indicators of ROS production. PMID:18488419

  11. Rhaphidophora korthalsii modulates peripheral blood natural killer cell proliferation, cytokine secretion and cytotoxicity

    PubMed Central

    2013-01-01

    Background Rhaphidophora korthalsii (Araceae) is a root-climber plant which has been widely used in Chinese traditional medicine for cancer and skin disease treatment. Previous reports have recorded its immunomodulatory effects on mice splenocyte and human peripheral blood. This study investigated the potential immunostimulatory effect of Rhaphidophora korthalsii on human PBMC enriched NK cell. Methods PBMC was exposed to various concentrations of R. korthalsii extract and the T and NK cell population in the control and extract treated PBMC were identified by immunophenotyping. Intracellular perforin and granzyme B expressions were detected by flow cytometry and extra-cellular Granzyme B, IFN-γ and TNF-α production in the isolated NK cells were determined by ELISA. The cytotoxicity of effector NK cell towards target K562 cell was assessed by CytoTox 96 assay. Results Rhaphidophora korthalsii methanol extract significantly increased PBMC NK cell population and intracellular perforin and granzyme B expressions. Moreover, the extract also enhanced the secretion of IFN-γ and TNF-α which subsequently enhanced the cytotoxicity of NK cell against the NK sensitive target K562 cell line. NK cell enriched with extract treated PBMC showed better activation than NK cell directly treated with the extract. Conclusion Our findings indicated a potential IL-2 free immunotherapy through direct and indirect R. korthalsii stimulation on NK cell activation. PMID:23800124

  12. Epigallocatechin-3-Gallate Reduces Cytotoxic Effects Caused by Dental Monomers: A Hypothesis.

    PubMed

    Jiao, Yang; Ma, Sai; Wang, Yirong; Li, Jing; Shan, Lequn; Chen, Jihua

    2015-01-01

    Resin monomers from dental composite materials leached due to incomplete polymerization or biodegradation may cause contact allergies and damage dental pulp. The cytotoxicity of dental resin monomers is due to a disturbance of intracellular redox equilibrium, characterized by an overproduction of reactive oxygen species (ROS) and depletion of reduced glutathione (GSH). Oxidative stress caused by dental resin monomers leads to the disturbance of vital cell functions and induction of cell apoptosis in affected cells. The nuclear factor-erythroid 2-related factor 2 (Nrf2) pathway plays a key role in the cellular defense system against oxidative and electrophilic stress. Epigallocatechin-3-gallate (EGCG) can activate the Nrf2 pathway and induce expression of a multitude of antioxidants and phase II enzymes that can restore redox homeostasis. Therefore, here, we tested the hypothesis that EGCG-mediated protection against resin monomer cytotoxicity is mediated by activation of the Nrf2 pathway. This study will help to elucidate the mechanism of resin monomer cytotoxicity and provide information that will be helpful in improving the biocompatibility of dental resin materials. PMID:26489899

  13. Cytotoxicity and reactive oxygen species generation from aggregated carbon and carbonaceous nanoparticulate materials

    PubMed Central

    Garza, Kristine M; Soto, Karla F; Murr, Lawrence E

    2008-01-01

    We have investigated the cytotoxicity and reactive oxygen species (ROS) generation for indoor and outdoor soots: candle, wood, diesel, tire, and natural gas burner soots – along with surrogate black carbon, various multiwall carbon nanotube aggregate materials, TiO2 (anatase) and chrysotile asbestos as reference materials. All soots were observed utilizing TEM and FESEM to be composed of aggregated, primary spherules (20–80 nm diameter) forming complex, branched fractal structures. These spherules were composed of intercalated, turbostratic arrangements of curved graphene fragments with varying concentrations of polycyclic aromatic hydrocarbon (PAH) isomers. In vitro cultures with an immortalized human lung epithelial carcinoma cell line (A549) treated with these materials showed decreased cell viability and variations in ROS production, with no correlations to PAH content. The data demonstrate that soots are cytotoxic and that cytotoxicity is not related to PAH content but is related to ROS generation, suggesting that soot induces cellular oxidative stress and that cell viability assays can be indicators of ROS production. PMID:18488419

  14. Combined cytotoxic effects of pesticide mixtures present in the Chinese diet on human hepatocarcinoma cell line.

    PubMed

    Ma, Mengmeng; Chen, Chen; Yang, Guiling; Li, Yun; Chen, Zhijun; Qian, Yongzhong

    2016-09-01

    Consumers might be simultaneously exposed to several pesticide residues contained in their food. Based on the results of previous studies, 20 pesticides were selected due to their high exposure levels to which the Chinese population is likely exposed through the diet. The purpose of this study was to measure the cytotoxicity of these pesticides in HepG2 cells in vitro, as an alternative approach to assess the toxicity of chemicals. Then, the pesticides and some of the mixtures with comparatively high cell-proliferating inhibitory activities were selected to test the cellular ROS level and apoptosis-related protein Caspase-3/7 content in HepG2 cells. The combined effects of these pesticide mixtures with the prediction was based on a combination index (CI)-isobologram equation and the pesticide combinations exhibited various types of interactions (synergism, antagonism, and additivity). Two individuals, one binary combinations, and three uniform design (UD) mixtures of the pesticides were found to have significant cytotoxic effects, along with significant time- and dose-dependent induction of caspase-3/7 activity in vitro, indicating that cytotoxicity caused by these pesticides might be attributed to the pro-oxidative and apoptosis induced potential. PMID:27300773

  15. Human immunodeficiency-causing mutation defines CD16 in spontaneous NK cell cytotoxicity

    PubMed Central

    Grier, Jennifer T.; Forbes, Lisa R.; Monaco-Shawver, Linda; Oshinsky, Jennifer; Atkinson, T. Prescott; Moody, Curtis; Pandey, Rahul; Campbell, Kerry S.; Orange, Jordan S.

    2012-01-01

    The Fc receptor on NK cells, FcγRIIIA (CD16), has been extensively studied for its role in mediating antibody-dependent cellular cytotoxicity (ADCC). A homozygous missense mutation in CD16 (encoding a L66H substitution) is associated with severe herpesvirus infections in rare patients. Here, we identified a new patient with this CD16 mutation and compared the patient’s NK cells to those of the originally reported patient. Patients with the L66H mutation had intact ADCC, but deficient spontaneous NK cell cytotoxicity and decreased surface expression of CD2, a coactivation receptor. Mechanistic studies in a human NK cell line, NK-92, demonstrated that CD16 expression correlated with CD2 surface levels and enabled killing of a melanoma cell line typically resistant to CD16-deficient NK-92 cells. An association between CD16 and CD2 was identified biochemically and at the immunological synapse, which elicited CD16 signaling after CD2 engagement. Stable expression of CD16 L66H in NK-92 cells recapitulated the patient phenotype, abrogating association of CD16 with CD2 as well as CD16 signaling after CD2 ligation. Thus, CD16 serves a role in NK cell–mediated spontaneous cytotoxicity through a specific association with CD2 and represents a potential mechanism underlying a human congenital immunodeficiency. PMID:23006327

  16. Identification of an epithelial cell receptor responsible for Clostridium difficile TcdB-induced cytotoxicity

    PubMed Central

    LaFrance, Michelle E.; Farrow, Melissa A.; Chandrasekaran, Ramyavardhanee; Sheng, Jinsong; Rubin, Donald H.; Lacy, D. Borden

    2015-01-01

    Clostridium difficile is the leading cause of hospital-acquired diarrhea in the United States. The two main virulence factors of C. difficile are the large toxins, TcdA and TcdB, which enter colonic epithelial cells and cause fluid secretion, inflammation, and cell death. Using a gene-trap insertional mutagenesis screen, we identified poliovirus receptor-like 3 (PVRL3) as a cellular factor necessary for TcdB-mediated cytotoxicity. Disruption of PVRL3 expression by gene-trap mutagenesis, shRNA, or CRISPR/Cas9 mutagenesis resulted in resistance of cells to TcdB. Complementation of the gene-trap or CRISPR mutants with PVRL3 resulted in restoration of TcdB-mediated cell death. Purified PVRL3 ectodomain bound to TcdB by pull-down. Pretreatment of cells with a monoclonal antibody against PVRL3 or prebinding TcdB to PVRL3 ectodomain also inhibited cytotoxicity in cell culture. The receptor is highly expressed on the surface epithelium of the human colon and was observed to colocalize with TcdB in both an explant model and in tissue from a patient with pseudomembranous colitis. These data suggest PVRL3 is a physiologically relevant binding partner that can serve as a target for the prevention of TcdB-induced cytotoxicity in C. difficile infection. PMID:26038560

  17. Effect of Intensified Decellularization of Equine Carotid Arteries on Scaffold Biomechanics and Cytotoxicity.

    PubMed

    Böer, Ulrike; Hurtado-Aguilar, Luis G; Klingenberg, Melanie; Lau, Skadi; Jockenhoevel, Stefan; Haverich, Axel; Wilhelmi, Mathias

    2015-11-01

    Decellularized equine carotid arteries (dEAC) are suggested to represent an alternative for alloplastic vascular grafts in haemodialysis patients to achieve vascular access. Recently it was shown that intensified detergent treatment completely removed cellular components from dEAC and thereby significantly reduced matrix immunogenicity. However, detergents may also affect matrix composition and stability and render scaffolds cytotoxic. Therefore, intensively decellularized carotids (int-dEAC) were now evaluated for their biomechanical characteristics (suture retention strength, burst pressure and circumferential compliance at arterial and venous systolic and diastolic pressure), matrix components (collagen and glycosaminoglycan content) and indirect and direct cytotoxicity (WST-8 assay and endothelial cell seeding) and compared with native (n-EAC) and conventionally decellularized carotids (con-dEAC). Both decellularization protocols comparably reduced matrix compliance (venous pressure compliance: 32.2 and 27.4% of n-EAC; p < 0.01 and arterial pressure compliance: 26.8 and 23.7% of n-EAC, p < 0.01) but had no effect on suture retention strength and burst pressure. Matrix characterization revealed unchanged collagen contents but a 39.0% (con-dEAC) and 26.4% (int-dEAC, p < 0.01) reduction of glycosaminoglycans, respectively. Cytotoxicity was not observed in either dEAC matrix which was also displayed by an intact endothelial lining after seeding. Thus, even intensified decellularization generates matrix scaffolds highly suitable for vascular tissue engineering purposes, e.g., the generation of haemodialysis shunts. PMID:25921001

  18. Evaluating Cytotoxicity of Hyaluronate Targeted Solid Lipid Nanoparticles of Etoposide on SK-OV-3 Cells

    PubMed Central

    Varshosaz, Jaleh; Sadeghi Aliabadi, Hojatollah

    2014-01-01

    The epithelial ovarian carcinoma is one of the most fatal gynecological cancers. Etoposide is used in treating platinum-resistant ovarian cancer. Sodium hyaluronate is a substance that binds to the CD44 receptors overexpressed in SK-OV-3 cells of epithelial ovarian carcinoma. The aim of the present work was to study the cytotoxicity effect of hyaluronate targeted solid lipid nanoparticles (SLNs) of etoposide on SK-OV-3 cells. The cytotoxicity of the targeted and nontargeted SLNs of etoposide was compared to free drug on the SK-OV-3 cells by MTT assay method. The cellular uptake of the targeted and nontargeted nanoparticles containing sodium fluorescein was also studied. The difference of cell vitality between nontargeted nanoparticles and also targeted nanoparticles with free drug was significant. Targeted nanoparticles also caused more toxicity than nontargeted nanoparticles (P < 0.05). After 4 hours of incubating, the fluorescence was remarkably higher in the cells treated by targeted SLNs rather than nontargeted ones, and there was no observable fluorescence in cells incubated with pure sodium fluorescein. Hyaluronate targeted SLNs containing etoposide increased the cytotoxicity of etoposide on SK-OV-3 cells which may be a worthwhile potential method for reducing the prescribed dose and systemic side effects of this drug in epithelial ovarian carcinoma. PMID:24868467

  19. Epigallocatechin-3-Gallate Reduces Cytotoxic Effects Caused by Dental Monomers: A Hypothesis

    PubMed Central

    Jiao, Yang; Ma, Sai; Wang, Yirong; Li, Jing; Shan, Lequn; Chen, Jihua

    2015-01-01

    Resin monomers from dental composite materials leached due to incomplete polymerization or biodegradation may cause contact allergies and damage dental pulp. The cytotoxicity of dental resin monomers is due to a disturbance of intracellular redox equilibrium, characterized by an overproduction of reactive oxygen species (ROS) and depletion of reduced glutathione (GSH). Oxidative stress caused by dental resin monomers leads to the disturbance of vital cell functions and induction of cell apoptosis in affected cells. The nuclear factor-erythroid 2-related factor 2 (Nrf2) pathway plays a key role in the cellular defense system against oxidative and electrophilic stress. Epigallocatechin-3-gallate (EGCG) can activate the Nrf2 pathway and induce expression of a multitude of antioxidants and phase II enzymes that can restore redox homeostasis. Therefore, here, we tested the hypothesis that EGCG-mediated protection against resin monomer cytotoxicity is mediated by activation of the Nrf2 pathway. This study will help to elucidate the mechanism of resin monomer cytotoxicity and provide information that will be helpful in improving the biocompatibility of dental resin materials. PMID:26489899

  20. Comparative in vitro cytotoxicity of volcanic ashes from Mount St. Helens, El Chichon, and Galunggung.

    PubMed

    Vallyathan, V; Robinson, V; Reasor, M; Stettler, L; Bernstein, R

    1984-01-01

    Dry sedimented volcanic ash samples from each of three widely separated volcanoes of the "Circum Pacific" region have been subjected to mineralogic analysis and in vitro tests for cytotoxicity. The ash samples from the three different volcanoes varied in particle size, surface area, and concentration of silica. Total crystalline silica in the respirable fraction of ashes was 1.5% (Mount St. Helens, Moses Lake); 1.36% (Galunggung, Bandung-1); 1.95% (Gallunggung, Bandung-2); and 1.72% (El Chichon, Tuxtla). Hemolysis as an index of cytotoxicity was measured by in vitro tests on sheep blood erythrocytes and indicated wide differences in hemolytic activity among ash samples. Alveolar macrophage cytosolic (lactate dehydrogenase) and lysosomal (beta-glucuronidase and beta-N-acetyl glucosaminidase) enzymes were measured as an index of cellular integrity following dust exposure. Hemolysis and release of enzymes from alveolar macrophages were greater with volcanic ash from Galunggung (Bandung-1) and El Chichon (Tuxtla) than the other ashes. Although crystalline silica induced an effect similar to volcanic ash from Galunggung (Bandung-1) on the release of enzymes from alveolar macrophages, the hemolytic potency of silica was much greater. Light and electron microscopic observations of dust-exposed alveolar macrophages indicated that the ash particles were readily phagocytized. These results indicate that volcanic ash is moderately cytotoxic and that exposure may lead to overt reactions and the exacerbation of preexisting chronic inflammatory processes. PMID:6097694

  1. Deoxysphingolipids, novel biomarkers for type 2 diabetes, are cytotoxic for insulin-producing cells.

    PubMed

    Zuellig, Richard A; Hornemann, Thorsten; Othman, Alaa; Hehl, Adrian B; Bode, Heiko; Güntert, Tanja; Ogunshola, Omolara O; Saponara, Enrica; Grabliauskaite, Kamile; Jang, Jae-Hwi; Ungethuem, Udo; Wei, Yu; von Eckardstein, Arnold; Graf, Rolf; Sonda, Sabrina

    2014-04-01

    Irreversible failure of pancreatic β-cells is the main culprit in the pathophysiology of diabetes, a disease that is now a global epidemic. Recently, elevated plasma levels of deoxysphingolipids, including 1-deoxysphinganine, have been identified as a novel biomarker for the disease. In this study, we analyzed whether deoxysphingolipids directly compromise the functionality of insulin-producing Ins-1 cells and primary islets. Treatment with 1-deoxysphinganine induced dose-dependent cytotoxicity with senescent, necrotic, and apoptotic characteristics and compromised glucose-stimulated insulin secretion. In addition, 1-deoxysphinganine altered cytoskeleton dynamics, resulting in intracellular accumulation of filamentous actin and activation of the Rho family GTPase Rac1. Moreover, 1-deoxysphinganine selectively upregulated ceramide synthase 5 expression and was converted to 1-deoxy-dihydroceramides without altering normal ceramide levels. Inhibition of intracellular 1-deoxysphinganine trafficking and ceramide synthesis improved the viability of the cells, indicating that the intracellular metabolites of 1-deoxysphinganine contribute to its cytotoxicity. Analyses of signaling pathways identified Jun N-terminal kinase and p38 mitogen-activated protein kinase as antagonistic effectors of cellular senescence. The results revealed that 1-deoxysphinganine is a cytotoxic lipid for insulin-producing cells, suggesting that the increased levels of this sphingolipid observed in diabetic patients may contribute to the reduced functionality of pancreatic β-cells. Thus, targeting deoxysphingolipid synthesis may complement the currently available therapies for diabetes. PMID:24379346

  2. The anticancer natural product ophiobolin A induces cytotoxicity by covalent modification of phosphatidylethanolamine

    PubMed Central

    Chidley, Christopher; Trauger, Sunia A; Birsoy, Kıvanç; O'Shea, Erin K

    2016-01-01

    Phenotypic screens allow the identification of small molecules with promising anticancer activity, but the difficulty in characterizing the mechanism of action of these compounds in human cells often undermines their value as drug leads. Here, we used a loss-of-function genetic screen in human haploid KBM7 cells to discover the mechanism of action of the anticancer natural product ophiobolin A (OPA). We found that genetic inactivation of de novo synthesis of phosphatidylethanolamine (PE) mitigates OPA cytotoxicity by reducing cellular PE levels. OPA reacts with the ethanolamine head group of PE in human cells to form pyrrole-containing covalent cytotoxic adducts and these adducts lead to lipid bilayer destabilization. Our characterization of this unusual cytotoxicity mechanism, made possible by unbiased genetic screening in human cells, suggests that the selective antitumor activity displayed by OPA may be due to altered membrane PE levels in cancer cells. DOI: http://dx.doi.org/10.7554/eLife.14601.001 PMID:27403889

  3. Synthesis, characterization and cytotoxic evaluation of chitosan nanoparticles: in vitro liver cancer model

    NASA Astrophysics Data System (ADS)

    Loutfy, Samah A.; Alam El-Din, Hanaa M.; Elberry, Mostafa H.; Allam, Nanis G.; Hasanin, M. T. M.; Abdellah, Ahmed M.

    2016-09-01

    To evaluate the cytotoxic effect of chitosan nanoparticles (CS-NPs) on an in vitro human liver cancer cell model (HepG2) and their possible application as a drug delivery system, we synthesized water-soluble CS-NPs, investigated their properties and extensively evaluated their cytotoxic activity on the cellular and molecular levels. A human liver cancer cell line was used as a model of human liver cancer. The CS-NPs were characterized using transmission electron microscopy, Fourier transform infrared spectroscopy, and zeta analysis. The cytotoxic effects of the CS-NPs on HepG2 cells were monitored by sulforhodamine B colorimetric assays for cytotoxicity screening and flow cytometric analysis. Molecular investigations including DNA fragmentation and the expression of some apoptotic genes on the transcriptional RNA level were conducted. Treatment of HepG2 with different concentrations of 150 nm diameter CS-NPs did not show alteration of cell morphology after 24 h of cell exposure. Also, when cells were treated with 100 μg ml‑1 of CS-NPs, 12% of them were killed and IC50 reached 239 μg ml‑1 after 48 h of cell exposure. Flow cytometry evaluation of the CS-NPs revealed mild accumulation in the G2/M phase followed by cellular DNA fragmentation after 48 h of cell exposure. Extensive evaluation of the cytotoxic effect of the CS-NPs showed messenger RNA (mRNA) apoptotic gene expression (p53, Bak, Caspase3) after 24 h of cell exposure with no expression of the mRNA of the caspase 3 gene after 48 h of cell exposure, suggesting the involvement of an intrinsic apoptotic caspase-independent pathway by increasing the exposure time of 100 μg ml‑1 of the CS-NPs. The engineered CS-NPs were controlled to a 150 nm size and charges of 40 mV and a concentration of 100 μg ml‑1 revealed a genotoxic effect on HepG2 after 48 h of cell exposure through intrinsic apoptotic caspase-independent mechanisms. Further quantitative analysis on the molecular and protein levels is still

  4. Cytotoxicity and Initial Biocompatibility of Endodontic Biomaterials (MTA and Biodentine™) Used as Root-End Filling Materials

    PubMed Central

    Escobar-García, Diana María; Aguirre-López, Eva; Méndez-González, Verónica

    2016-01-01

    Objective. The aim of this study was to evaluate the cytotoxicity and cellular adhesion of Mineral Trioxide Aggregate (MTA) and Biodentine (BD) on periodontal ligament fibroblasts (PDL). Methods. PDL cells were obtained from nonerupted third molars and cultured; MTS cellular profusion test was carried out in two groups: MTA and BD, with respective controls at different time periods. Also, the LIVE/DEAD assay was performed at 24 h. For evaluation of cellular adhesion, immunocytochemistry was conducted to discern the expression of Integrin β1 and Vinculin at 12 h and 24 h. Statistical analysis was performed by the Kruskal-Wallis and Mann-Whitney U tests. Results. MTA and BD exhibited living cells up to 7 days. More expressions of Integrin β1 and Vinculin were demonstrated in the control group, followed by BD and MTA, which also showed cellular loss and morphological changes. There was a significant difference in the experimental groups cultured for 5 and 7 days compared with the control, but there was no significant statistical difference between both cements. Conclusions. Neither material was cytotoxic during the time evaluated. There was an increase of cell adhesion through the expression of focal contacts observed in the case of BD, followed by MTA, but not significantly. PMID:27595108

  5. A new generation of sterile and radiopaque impression materials: an in vitro cytotoxicity study.

    PubMed

    Coppi, Chiara; Paolinelli Devincenzi, Chiara; Bortolini, Sergio; Consolo, Ugo; Tiozzo, Roberta

    2007-07-01

    Impression materials are largely used to record the geometry of dental tissue. Hence, the assessment of their possible cytotoxicity is a necessary step in the evaluation of their biocompatibility. The present study is carried out to evaluate the cytotoxicity of a new elastomeric sterile and radiopaque impression material. Human gingival fibroblasts, cultured in vitro are exposed directly to Elite Implant in three different viscosities, heavy, medium, and light. At 3, 9, 24, 48, and 72 h, the cellular proliferation is evaluated. In parallel, human gingival fibroblasts are exposed indirectly by means of fluid extracts of Elite Implant. The cellular viability is evaluated by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide, (MTT) assay (Sigma, St Louis, Mo). The gingival fibroblasts proliferation and viability are unaffected by the presence of Elite Implant. This new impression material may represent a safe medical device for clinical and surgical applications. In addition, this material is radiopaque and, thus, can be identified radiographically. PMID:17065163

  6. Role of vitamin D in cytotoxic T lymphocyte immunity to pathogens and cancer.

    PubMed

    Sarkar, Surojit; Hewison, Martin; Studzinski, George P; Li, Yan Chun; Kalia, Vandana

    2016-04-01

    The discovery of vitamin D receptor (VDR) expression in immune cells has opened up a new area of research into immunoregulation by vitamin D, a niche that is distinct from its classical role in skeletal health. Today, about three decades since this discovery, numerous cellular and molecular targets of vitamin D in the immune system have been delineated. Moreover, strong clinical associations between vitamin D status and the incidence/severity of many immune-regulated disorders (e.g. infectious diseases, cancers and autoimmunity) have prompted the idea of using vitamin D supplementation to manipulate disease outcome. While much is known about the effects of vitamin D on innate immune responses and helper T (TH) cell immunity, there has been relatively limited progress on the frontier of cytotoxic T lymphocyte (CTL) immunity - an arm of host cellular adaptive immunity that is crucial for the control of such intracellular pathogens as human immunodeficiency virus (HIV), tuberculosis (TB), malaria, and hepatitis C virus (HCV). In this review, we discuss the strong historical and clinical link between vitamin D and infectious diseases that involves cytotoxic T lymphocyte (CTL) immunity, present our current understanding as well as critical knowledge gaps in the realm of vitamin D regulation of host CTL responses, and highlight potential regulatory connections between vitamin D and effector and memory CD8 T cell differentiation events during infections. PMID:26479950

  7. Natural phenylpropanoids protect endothelial cells against oxidized LDL-induced cytotoxicity.

    PubMed

    Martin-Nizard, Françoise; Sahpaz, Sevser; Furman, Christophe; Fruchart, Jean-Charles; Duriez, Patrick; Bailleul, François

    2003-03-01

    There is increasing evidence that oxidized low-density lipoproteins (Ox-LDL) might be involved in the pathogenesis of atherosclerosis and it has been reported that polyphenols inhibit LDL peroxidation and atherosclerosis. Minimally oxidized LDL (mOx-LDL) induce cytotoxicity in cultured bovine aortic endothelial cells (BAEC). The goal of this study was to test the protective effect of five natural polyphenols isolated from the aerial parts of Marrubium vulgare L. against mOx-LDL-induced cytotoxicity in BAEC. Four phenylpropanoid glycosides (acteoside 1, forsythoside B 2, arenarioside 3, ballotetroside 4) and one non-glycosidic derivative (caffeoyl-l-malic acid 5) were tested. These compounds inhibited both copper (Cu 2+)- and 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced in vitro LDL oxidation and preserved the morphological aspects of BAEC during their incubation with mOx-LDL. Furthermore, they reduced the accumulation of aldehydes in the cultured medium during the incubation of BAEC with mOx-LDL and prevented cellular LDH leakage during this period. These data suggest that natural phenylpropanoids inhibit mOx-LDL-induced cellular toxicity and that inhibition of lipid peroxidation could be a key mechanism in the cytoprotective effect of these molecules. PMID:12677522

  8. Cytotoxicity and Characterization of Particles Collected From an Indium–Tin Oxide Production Facility

    PubMed Central

    Badding, Melissa A.; Stefaniak, Aleksandr B.; Fix, Natalie R.; Cummings, Kristin J.; Leonard, Stephen S.

    2014-01-01

    Occupational exposure to indium compound particles has recently been associated with lung disease among workers in the indium–tin oxide (ITO) industry. Previous studies suggested that excessive alveolar surfactant and reactive oxygen species (ROS) may play a role in the development of pulmonary lesions following exposure to indium compounds. However, toxicity at the cellular level has not been comprehensively evaluated. Thus, the aim of this study was to assess which, if any, compounds encountered during ITO production are toxic to cultured cells and ultimately contribute to the pathogenesis of indium lung disease. The compounds used in this study were collected from eight different processing stages at an ITO production facility. Enhanced dark field imaging showed 5 of the compounds significantly associated with cells within 1 h, suggesting that cellular reactions to the compound particles may be occurring rapidly. To examine the potential cytotoxic effects of these associations, ROS generation, cell viability, and apoptosis were evaluated following exposures in RAW 264.7 mouse monocyte macrophage and BEAS-2B human bronchial epithelial cell lines. Both exhibited reduced viability with exposures, while apoptosis only occurred in RAW 264.7 cells. Our results suggested that excessive ROS production is likely not the predominant mechanism underlying indium-induced lung disease. However, the effects on cell viability reveal that several of the compounds are cytotoxic, and therefore, exposures need to be carefully monitored in the industrial setting. PMID:25208660

  9. Cytotoxicity of CD56-positive lymphocytes against autologous B-cell precursor acute lymphoblastic leukemia cells

    PubMed Central

    Fei, Fei; Lim, Min; George, Aswathi A.; Kirzner, Jonathan; Lee, Dean; Seeger, Robert; Groffen, John; Abdel-Azim, Hisham; Heisterkamp, Nora

    2014-01-01

    Precursor B-lineage acute lymphoblastic leukemia (pre-B ALL) affects hematopoietic development and therefore is associated with immune deficiencies that can be further exacerbated by chemotherapy. It is unclear if and when monoclonal antibodies (mAbs) that stimulate antibody-mediated cellular cytotoxicity (ADCC) can be used for treatment because this depends on the presence of functional effector cells. Here, we used flow cytometry to determine that patient samples at diagnosis, post-induction and relapse contain detectable numbers of CD56+ cells. We were able to selectively expand CD56+ immune effector cells from bone marrow and peripheral blood samples at diagnosis and at various stages of treatment by co-culture with artificial antigen-presenting K562 clone 9.mbIL-21 cells. Amplified CD56+CD3- cells had spontaneous and anti-BAFF-R mAb-stimulated ADCC activity against autologous ALL cells, which could be further enhanced by IL15. Importantly, matched CD56+ effector cells also killed autologous ALL cells grown out from leukemia samples of the same patient, through both spontaneous as well as antibody-dependent cellular cytotoxicity. Since autologous cell therapy will not be complicated by graft-versus-host disease, our results show that expanded CD56+ cells could be applied for treatment of pre-B-ALL without transplantation, or for purging of bone marrow in the setting of autologous bone marrow transplants. PMID:25134458

  10. Continuum representations of cellular solids

    SciTech Connect

    Neilsen, M.K.

    1993-09-01

    Cellular materials consist of interconnected struts or plates which form cells. The struts or plates are constructed from a variety of metals, polymers, ceramics and wood products. Cellular materials are often used in impact limiters for shipping containers to protect the contents from accidental impact events. These materials exhibit a variety of complex behavior when subjected to crushing loads. This research focuses on the development of continuum representations of cellular solids that can be used in the finite element analysis of shipping container accidents. A significant portion of this work is the development of a new methodology to relate localized deformations to appropriate constitutive descriptions. This methodology provides the insight needed to select constitutive descriptions for cellular solids that capture the localized deformations that are observed experimentally. Constitutive relations are developed for two different cellular materials, aluminum honeycomb and polyurethane foam. These constitutive relations are based on plasticity and continuum damage theories. Plasticity is used to describe the permanent deformation exhibited by both aluminum honeycomb and polyurethane foam. Continuum damage is needed to capture the change in elastic parameters due to cracking of the polyurethane cell wall materials. The new constitutive description of polyurethane foam is implemented in both static and dynamic finite element codes, and analytical and numerical predictions are compared with available experimental data.

  11. Different mechanisms are involved in DNA damage, bacterial mutagenicity and cytotoxicity induced by 1,2-dibromo-3-chloropropane in suspensions of rat liver cells.

    PubMed

    Holme, J A; Søderlund, E J; Brunborg, G; Omichinski, J G; Bekkedal, K; Trygg, B; Nelson, S D; Dybing, E

    1989-01-01

    1,2-Dibromo-3-chloropropane (DBCP) induced DNA damage, measured by an automated alkaline elution method, in suspensions of rat liver parenchymal cells at low concentrations (1-10 microM). At much higher concentrations (0.5-2.5 mM), DBCP was metabolized to products that were mutagenic to Salmonella typhimurium TA100 co-incubated with the liver cells. At these higher concentrations a marked depletion of cellular glutathione was seen and at 2.5 mM DBCP was cytotoxic. Perdeuterated DBCP (D5-DBCP) caused less DNA damage in the liver cells than DBCP, most likely because of decrease in cytochrome P-450 dependent metabolism. A more pronounced decrease in mutagenicity occurred with D5-DBCP compared to DBCP, whereas the two compounds were equally cytotoxic. Preincubation of the liver cells with diethylmaleate or buthionine sulfoximine, to lower cellular levels of glutathione, decreased DBCP induced DNA damage. The decrease in DNA damage was proportional to the decrease in cellular glutathione levels. In contrast, diethylmaleate enhanced DBCP-induced bacterial mutagenicity and cellular cytotoxicity. The cytotoxic effect could be partly blocked by addition of ascorbate. From the data presented we suggest that: (i) cytochrome P-450 dependent oxidation as well as glutathione conjugation are involved in DBCP induced DNA damage, (ii) cytochrome P-450 dependent oxidation leads to formation of products mutagenic to bacteria and (iii) the cytotoxicity induced by DBCP in the liver cells in vitro is caused by oxidative damage following glutathione depletion and/or direct membrane damage. PMID:2642751

  12. N-substituted 4-aminobenzamides (procainamide analogs): an assessment of multiple cellular effects concerning ion trapping.

    PubMed

    Morissette, Guillaume; Moreau, Emmanuel; C-Gaudreault, René; Marceau, François

    2005-12-01

    Procainamide and related triethylamine-substituted 4-aminobenzamides, such as metoclopramide and declopramide, exert cellular effects potentially exploitable in oncology at millimolar concentrations (DNA demethylation, nuclear factor-kappaB inhibition, apoptosis) and display anti-inflammatory properties. However, these drugs induce massive cell vacuolization at similar concentrations, a response initiated by vacuolar (V-) ATPase-dependent ion trapping into and osmotic swelling of acidic organelles. We have examined whether this overlooked response might be related to the effects on cell proliferation and viability using cultured vascular smooth muscle cells and tumor-derived cell lines (Morris 7777 hepatoma, HT-1080 fibrosarcoma). Giant vacuole formation, of confirmed trans-Golgi origin (labeled with C5-ceramide, p230, golgin-97), is a cellular response to all tested amines in the series (> or = 2.5 mM), including triethylamine. These drugs and the V-ATPase inhibitor bafilomycin A1 inhibited smooth muscle cell proliferation, suggesting that acidification of a cellular compartment is essential to cell division. The cytotoxicity was maximal with metoclopramide, and this effect was minimally influenced by bafilomycin A1; furthermore, metoclopramide (2.5 mM) induced apoptosis in tumor cells as judged by poly(ADP-ribose)polymerase (PARP) cleavage. Triethylamine and procainamide exhibit a low level of cytotoxicity variably reduced by bafilomycin co-treatment. In Morris cells, the secretion of alpha-fetoprotein is inhibited by amines, consistent with the impairment of the secretory pathway. The most highly substituted 4-aminobenzamides are significant NF-kappaB inhibitors in smooth muscle cells. Although some effects of 4-aminobenzamides are independent of V-ATPase-driven ion trapping (inhibition of NF-kappaB nuclear translocation, agent-specific cytotoxicity, PARP cleavage), other effects are dependent on this phenomenon (vacuolization, a component of the cytotoxicity

  13. Inhibition of hypochlorous acid-induced cellular toxicity by nitrite

    NASA Astrophysics Data System (ADS)

    Whiteman, Matthew; Hooper, D. Craig; Scott, Gwen S.; Koprowski, Hilary; Halliwell, Barry

    2002-09-01

    Chronic inflammation results in increased nitrogen monoxide (NO) formation and the accumulation of nitrite (NO). Neutrophils stimulated by various inflammatory mediators release myeloperoxidase to produce the cytotoxic agent hypochlorous acid (HOCl). Exposure of chondrocytic SW1353 cells to HOCl resulted in a concentration- and time-dependent loss in viability, ATP, and glutathione levels. Treatment of cells with NO but not nitrate (NO) substantially decreased HOCl-dependent cellular toxicity even when NO was added at low (μM) concentrations. In contrast, NO alone (even at 1 mM concentrations) did not affect cell viability or ATP and glutathione levels. These data suggest that NO accumulation at chronic inflammatory sites, where both HOCl and NO are overproduced, may be cytoprotective against damage caused by HOCl. We propose that this is because HOCl is removed by reacting with NO to give nitryl chloride (NO2Cl), which is less damaging in our cell system. inflammation | cell toxicity | nitryl chloride | nitric oxide | arthritis

  14. Study of Stevia rebaudiana Bertoni antioxidant activities and cellular properties.

    PubMed

    Bender, Cecilia; Graziano, Sara; Zimmermann, Benno F

    2015-01-01

    The aim of our study was to determine the antioxidant activities, cytotoxicity and proliferative properties in Stevia rebaudiana leaves and stems. Leaves extracts exhibited a higher antioxidant activity than stems extract, through oxygen radical absorbance capacity (ORAC) and cellular antioxidant activity (CAA) assays. Stevioside and rebaudioside A, the main sweetening metabolites in stevia leaves, exhibited a low ORAC value in comparison with plant extracts, while did not elicit any CAA. Stevia rebaudiana did not exhibit toxicity against HepG2 (hepatocellular carcinoma) human cells. No proliferative nor catalase modulations were observed in cells treated with such extracts. Our findings support the promising role of stevia that, apart from its sweetness, can act as a source of antioxidants, even at the intracellular level. This activity makes S. rebaudiana crude extract an interesting resource of natural sweetness with antioxidant properties which may find numerous applications in foods and nutritional supplements industries. PMID:26008718

  15. Serglycin determines secretory granule repertoire and regulates natural killer cell and cytotoxic T lymphocyte cytotoxicity.

    PubMed

    Sutton, Vivien R; Brennan, Amelia J; Ellis, Sarah; Danne, Jill; Thia, Kevin; Jenkins, Misty R; Voskoboinik, Ilia; Pejler, Gunnar; Johnstone, Ricky W; Andrews, Daniel M; Trapani, Joseph A

    2016-03-01

    The anionic proteoglycan serglycin is a major constituent of secretory granules in cytotoxic T lymphocyte (CTL)/natural killer (NK) cells, and is proposed to promote the safe storage of the mostly cationic granule toxins, granzymes and perforin. Despite the extensive defects of mast cell function reported in serglycin gene-disrupted mice, no comprehensive study of physiologically relevant CTL/NK cell populations has been reported. We show that the cytotoxicity of serglycin-deficient CTL and NK cells is severely compromised but can be partly compensated in both cell types when they become activated. Reduced intracellular granzyme B levels were noted, particularly in CD27(+) CD11b(+) mature NK cells, whereas serglycin(-/-) TCR-transgenic (OTI) CD8 T cells also had reduced perforin stores. Culture supernatants from serglycin(-/-) OTI T cells and interleukin-2-activated NK contained increased granzyme B, linking reduced storage with heightened export. By contrast, granzyme A was not significantly reduced in cells lacking serglycin, indicating differentially regulated trafficking and/or storage for the two granzymes. A quantitative analysis of different granule classes by transmission electronmicroscopy showed a selective loss of dense-core granules in serglycin(-/-) CD8(+) CTLs, although other granule types were maintained quantitatively. The findings of the present study show that serglycin plays a critical role in the maturation of dense-core cytotoxic granules in cytotoxic lymphocytes and the trafficking and storage of perforin and granzyme B, whereas granzyme A is unaffected. The skewed retention of cytotoxic effector molecules markedly reduces CTL/NK cell cytotoxicity, although this is partly compensated for as a result of activating the cells by physiological means. PMID:26756195

  16. Uptake and cytotoxic effects of multi-walled carbon nanotubes in human bronchial epithelial cells

    SciTech Connect

    Hirano, Seishiro; Fujitani, Yuji; Furuyama, Akiko; Kanno, Sanae

    2010-11-15

    Carbon nanotubes (CNT) are cytotoxic to several cell types. However, the mechanism of CNT toxicity has not been fully studied, and dosimetric analyses of CNT in the cell culture system are lacking. Here, we describe a novel, high throughput method to measure cellular uptake of CNT using turbimetry. BEAS-2B, a human bronchial epithelial cell line, was used to investigate cellular uptake, cytotoxicity, and inflammatory effects of multi-walled CNT (MWCNT). The cytotoxicity of MWCNT was higher than that of crocidolite asbestos in BEAS-2B cells. The IC{sub 50} of MWCNT was 12 {mu}g/ml, whereas that of asbestos (crocidolite) was 678 {mu}g/ml. Over the course of 5 to 8 h, BEAS-2B cells took up 17-18% of the MWCNT when they were added to the culture medium at a concentration of 10 {mu}g/ml. BEAS-2B cells were exposed to 2, 5, or 10 {mu}g/ml of MWCNT, and total RNA was extracted for cytokine cDNA primer array assays. The culture supernatant was collected for cytokine antibody array assays. Cytokines IL-6 and IL-8 increased in a dose dependent manner at both the mRNA and protein levels. Migration inhibitory factor (MIF) also increased in the culture supernatant in response to MWCNT. A phosphokinase array study using lysates from BEAS-2B cells exposed to MWCNT indicated that phosphorylation of p38, ERK1, and HSP27 increased significantly in response to MWCNT. Results from a reporter gene assays using the NF-{kappa}B or AP-1 promoter linked to the luciferase gene in transiently transfected CHO-KI cells revealed that NF-{kappa}B was activated following MWCNT exposure, while AP-1 was not changed. Collectively, MWCNT activated NF-{kappa}B, enhanced phosphorylation of MAP kinase pathway components, and increased production of proinflammatory cytokines in human bronchial epithelial cells.

  17. Colorectal carcinogenesis: a cellular response to sustained risk environment.

    PubMed

    Fung, Kim Y C; Ooi, Cheng Cheng; Zucker, Michelle H; Lockett, Trevor; Williams, Desmond B; Cosgrove, Leah J; Topping, David L

    2013-01-01

    The current models for colorectal cancer (CRC) are essentially linear in nature with a sequential progression from adenoma through to carcinoma. However, these views of CRC development do not explain the full body of published knowledge and tend to discount environmental influences. This paper proposes that CRC is a cellular response to prolonged exposure to cytotoxic agents (e.g., free ammonia) as key events within a sustained high-risk colonic luminal environment. This environment is low in substrate for the colonocytes (short chain fatty acids, SCFA) and consequently of higher pH with higher levels of free ammonia and decreased mucosal oxygen supply as a result of lower visceral blood flow. All of these lead to greater and prolonged exposure of the colonic epithelium to a cytotoxic agent with diminished aerobic energy availability. Normal colonocytes faced with this unfavourable environment can transform into CRC cells for survival through epigenetic reprogramming to express genes which increase mobility to allow migration and proliferation. Recent data with high protein diets confirm that genetic damage can be increased, consistent with greater CRC risk. However, this damage can be reversed by increasing SCFA supply by feeding fermentable fibre as resistant starch or arabinoxylan. High protein, low carbohydrate diets have been shown to alter the colonic environment with lower butyrate levels and apparently greater mucosal exposure to ammonia, consistent with our hypothesis. Evidence is drawn from in vivo and in vitro genomic and biochemical studies to frame experiments to test this proposition. PMID:23807509

  18. Cytotoxic activity against human neuroblastoma and melanoma cells mediated by IgM antibodies derived from peripheral blood of healthy donors.

    PubMed

    Devarapu, Satish Kumar; Mamidi, Srinivas; Plöger, Frank; Dill, Othmar; Blixt, Ola; Kirschfink, Michael; Schwartz-Albiez, Reinhard

    2016-06-15

    A small percentage of healthy donors identified in the Western population carry antibodies in their peripheral blood which convey cytotoxic activity against certain human melanoma and neuroblastoma cell lines. We measured the cytotoxic activity of sera and plasmas from healthy donors on the human neuroblastoma cell line Kelly and various melanoma cell lines. Antibodies of IgM isotype, presumably belonging to the class of naturally occurring antibodies, exerted cytotoxic activity in a complement-dependent fashion. Apart from complement-dependent tumor cell lysis, we observed C3 opsonization in all tumor cell lines upon treatment with cytotoxic plasmas. Cell lines tested primarily expressed membrane complement regulatory proteins (mCRP) CD46, CD55 and CD59 to various extents. Blocking of mCRPs by monoclonal antibodies enhanced cell lysis and opsonization, though some melanoma cells remained resistant to complement attack. Epitopes recognized by cytotoxic antibodies were represented by gangliosides such as GD2 and GD3, as evidenced by cellular sialidase pretreatment and enhanced expression of distinct gangliosides. It remains to be clarified why only a small fraction of healthy persons carry these antitumor cytotoxic antibodies. PMID:26830059

  19. Jadomycin breast cancer cytotoxicity is mediated by a copper-dependent, reactive oxygen species–inducing mechanism

    PubMed Central

    Hall, Steven R; Blundon, Heather L; Ladda, Matthew A; Robertson, Andrew W; Martinez-Farina, Camilo F; Jakeman, David L; Goralski, Kerry B

    2015-01-01

    Jadomycins are natural products biosynthesized by the bacteria Streptomyces venezuelae which kill drug-sensitive and multidrug-resistant breast cancer cells in culture. Currently, the mechanisms of jadomycin cytotoxicity are poorly understood; however, reactive oxygen species (ROS)–induced DNA cleavage is suggested based on bacterial plasmid DNA cleavage studies. The objective of this study was to determine if and how ROS contribute to jadomycin cytotoxicity in drug-sensitive MCF7 (MCF7-CON) and taxol-resistant MCF7 (MCF7-TXL) breast cancer cells. As determined using an intracellular, fluorescent, ROS-detecting probe, jadomycins B, S, SPhG, and F dose dependently increased intracellular ROS activity 2.5- to 5.9-fold. Cotreatment with the antioxidant N-acetyl cysteine lowered ROS concentrations to below baseline levels and decreased the corresponding cytotoxic potency of the four jadomycins 1.9- to 3.3-fold, confirming a ROS-mediated mechanism. Addition of CuSO4 enhanced, whereas addition of the Cu(II)-chelator d-penicillamine reduced, the ROS generation and cytotoxicity of each jadomycin. Specific inhibitors of the antioxidant enzymes, superoxide dismutase 1, glutathione S-transferase, and thioredoxin reductase, but not catalase, enhanced jadomycin-mediated ROS generation and anticancer activity. In conclusion, the results indicate that jadomycin cytotoxicity involves the generation of cytosolic superoxide via a Cu(II)-jadomycin reaction, a mechanism common to all jadomycins tested and observed in MCF7-CON and drug-resistant MCF7-TXL cells. The superoxide dismutase 1, glutathione, and peroxiredoxin/thioredoxin cellular antioxidant enzyme pathways scavenged intracellular ROS generated by jadomycin treatment. Blocking these antioxidant pathways could serve as a strategy to enhance jadomycin cytotoxic potency in drug-sensitive and multidrug-resistant breast cancers. PMID:25729577

  20. Aging, Cellular Senescence, and Cancer

    PubMed Central

    Campisi, Judith

    2014-01-01

    For most species, aging promotes a host of degenerative pathologies that are characterized by debilitating losses of tissue or cellular function. However, especially among vertebrates, aging also promotes hyperplastic pathologies, the most deadly of which is cancer. In contrast to the loss of function that characterizes degenerating cells and tissues, malignant (cancerous) cells must acquire new (albeit aberrant) functions that allow them to develop into a lethal tumor. This review discusses the idea that, despite seemingly opposite characteristics, the degenerative and hyperplastic pathologies of aging are at least partly linked by a common biological phenomenon: a cellular stress response known as cellular senescence. The senescence response is widely recognized as a potent tumor suppressive mechanism. However, recent evidence strengthens the idea that it also drives both degenerative and hyper-plastic pathologies, most likely by promoting chronic inflammation. Thus, the senescence response may be the result of antagonistically pleiotropic gene action. PMID:23140366

  1. Aging, cellular senescence, and cancer.

    PubMed

    Campisi, Judith

    2013-01-01

    For most species, aging promotes a host of degenerative pathologies that are characterized by debilitating losses of tissue or cellular function. However, especially among vertebrates, aging also promotes hyperplastic pathologies, the most deadly of which is cancer. In contrast to the loss of function that characterizes degenerating cells and tissues, malignant (cancerous) cells must acquire new (albeit aberrant) functions that allow them to develop into a lethal tumor. This review discusses the idea that, despite seemingly opposite characteristics, the degenerative and hyperplastic pathologies of aging are at least partly linked by a common biological phenomenon: a cellular stress response known as cellular senescence. The senescence response is widely recognized as a potent tumor suppressive mechanism. However, recent evidence strengthens the idea that it also drives both degenerative and hyperplastic pathologies, most likely by promoting chronic inflammation. Thus, the senescence response may be the result of antagonistically pleiotropic gene action. PMID:23140366

  2. Fracture mechanics of cellular glass

    NASA Technical Reports Server (NTRS)

    Zwissler, J. G.; Adams, M. A.

    1981-01-01

    The fracture mechanics of cellular glasses (for the structural substrate of mirrored glass for solr concentrator reflecting panels) are discussed. Commercial and developmental cellular glasses were tested and analyzed using standard testing techniques and models developed from linear fracture mechanics. Two models describing the fracture behavior of these materials were developed. Slow crack growth behavior in cellular glass was found to be more complex than that encountered in dense glasses or ceramics. The crack velocity was found to be strongly dependent upon water vapor transport to the tip of the moving crack. The existence of a static fatigue limit was not conclusively established, however, it is speculated that slow crack growth behavior in Region 1 may be slower, by orders of magnitude, than that found in dense glasses.

  3. Cellular-based preemption system

    NASA Technical Reports Server (NTRS)

    Bachelder, Aaron D. (Inventor)

    2011-01-01

    A cellular-based preemption system that uses existing cellular infrastructure to transmit preemption related data to allow safe passage of emergency vehicles through one or more intersections. A cellular unit in an emergency vehicle is used to generate position reports that are transmitted to the one or more intersections during an emergency response. Based on this position data, the one or more intersections calculate an estimated time of arrival (ETA) of the emergency vehicle, and transmit preemption commands to traffic signals at the intersections based on the calculated ETA. Additional techniques may be used for refining the position reports, ETA calculations, and the like. Such techniques include, without limitation, statistical preemption, map-matching, dead-reckoning, augmented navigation, and/or preemption optimization techniques, all of which are described in further detail in the above-referenced patent applications.

  4. Correlation of nucleoside and nucleobase transporter gene expression with antimetabolite drug cytotoxicity.

    PubMed

    Lu, Xin; Gong, Shimei; Monks, Anne; Zaharevitz, Daniel; Moscow, Jeffrey A

    2002-01-01

    Antimetabolite drugs that inhibit nucleic acid metabolism are widely used in cancer chemotherapy. Nucleoside and nucleobase transporters are important for the cellular uptake of nucleic acids and their corresponding anticancer analogue drugs. Thus, these transporters may play a role both in antimetabolite drug sensitivity, by mediating the uptake of nucleoside analogues, and in antimetabolite drug resistance, by mediating the uptake of endogenous nucleosides that may rescue cells from toxicity. Therefore, we examined the relation of the expression of nucleoside and nucleobase transporters to antimetabolite cytotoxicity. We measured the RNA levels of all eight known nucleoside and nucleobase transporters in 50 cell lines included in the National Cancer Institute's Anticancer Drug Screen panel. RNA levels of concentrative nucleoside transporters (CNTs), equilibrative nucleoside transporters (ENTs) and nucleobase transporters (NCBTs) were determined by quantitative RT-PCR using real-time fluorescence acquisition. This method was validated by measuring the expression of the MDR1 gene, and correlating our results with independently determined measurements of MDR1 RNA levels and protein function in these cell lines. We then correlated the pattern of RNA levels to the pattern of cytotoxicity of anticancer drugs in the NCI drug screen database using the COMPARE analysis. Several hypothesized relations between transporter gene expression and cytotoxicity, based upon known interactions between certain nucleoside analogues and transporter proteins, were not observed, suggesting that expression of individual transporters may not be a significant determinant of the cytotoxicity of these drugs. The most closely correlated drug cytotoxicity patterns to transporter gene expression patterns (where increased expression corresponds to increase sensitivity) included those between CNT1 and O6-methylguanine and between ENT2 and hydroxyurea. We also observed that p53 status influenced

  5. Cocaine elicits autophagic cytotoxicity via a nitric oxide-GAPDH signaling cascade.

    PubMed

    Guha, Prasun; Harraz, Maged M; Snyder, Solomon H

    2016-02-01

    Cocaine exerts its behavioral stimulant effects by facilitating synaptic actions of neurotransmitters such as dopamine and serotonin. It is also neurotoxic and broadly cytotoxic, leading to overdose deaths. We demonstrate that the cytotoxic actions of cocaine reflect selective enhancement of autophagy, a process that physiologically degrades metabolites and cellular organelles, and that uncontrolled autophagy can also lead to cell death. In brain cultures, cocaine markedly increases levels of LC3-II and depletes p62, both actions characteristic of autophagy. By contrast, cocaine fails to stimulate cell death processes reflecting parthanatos, monitored by cleavage of poly(ADP ribose)polymerase-1 (PARP-1), or necroptosis, assessed by levels of phosphorylated mixed lineage kinase domain-like protein. Pharmacologic inhibition of autophagy protects neurons against cocaine-induced cell death. On the other hand, inhibition of parthanatos, necroptosis, or apoptosis did not change cocaine cytotoxicity. Depletion of ATG5 or beclin-1, major mediators of autophagy, prevents cocaine-induced cell death. By contrast, depleting caspase-3, whose cleavage reflects apoptosis, fails to alter cocaine cytotoxicity, and cocaine does not alter caspase-3 cleavage. Moreover, depleting PARP-1 or RIPK1, key mediators of parthanatos and necroptosis, respectively, did not prevent cocaine-induced cell death. Autophagic actions of cocaine are mediated by the nitric oxide-glyceraldehyde-3-phosphate dehydrogenase signaling pathway. Thus, cocaine-associated autophagy is abolished by depleting GAPDH via shRNA; by the drug CGP3466B, which prevents GAPDH nitrosylation; and by mutating cysteine-150 of GAPDH, its site of nitrosylation. Treatments that selectively influence cocaine-associated autophagy may afford therapeutic benefit. PMID:26787898

  6. Suppressing the cytotoxicity of CuO nanoparticles by uptake of curcumin/BSA particles.

    PubMed

    Zhang, Wenjing; Jiang, Pengfei; Chen, Ying; Luo, Peihua; Li, Guanqun; Zheng, Botuo; Chen, Wei; Mao, Zhengwei; Gao, Changyou

    2016-05-01

    The adverse effects of metal-based nanoparticles on human beings and the environment have received extensive attention recently. It is urgently required to develop a simple and effective method to suppress the toxicity of metal-based nanomaterials. In this study, a hydrophobic antioxidant and a chelation agent curcumin (CUR) were encapsulated into bovine serum albumin (BSA) particles by a simple co-precipitation method, and followed by glutaraldehyde cross-linking. The CUR/BSA particles had an average size of 300 nm in diameter with a negatively charged surface and sustained curcumin release properties. The cellular uptake and cytotoxicity of CUR/BSA particles were followed on A549 cells, HepG2 cells and RAW264.7 cells. The CUR/BSA particles had higher intracellular accumulation and lower cytotoxicity compared with the free curcumin at the same drug concentration. The CUR/BSA particles could suppress the cytotoxicity generated by CuO nanoparticles as a result of decrease of both the intracellular reactive oxygen species (ROS) level and Cu(2+) concentration, while the free curcumin did not show any obvious detoxicating effect. The detoxicating effects of CUR/BSA particles were further studied in an intratracheal instillation model in vivo, demonstrating significant reduction of toxicity and inflammatory response in rat lungs induced by CuO nanoparticles. The concept-proving study demonstrates the potential of the CUR/BSA particles in suppressing cytotoxicity of metal-based nanomaterials, which is a paramount requirement for the safe application of nanotechnology. PMID:27098928

  7. Cocaine elicits autophagic cytotoxicity via a nitric oxide-GAPDH signaling cascade

    PubMed Central

    Guha, Prasun; Harraz, Maged M.; Snyder, Solomon H.

    2016-01-01

    Cocaine exerts its behavioral stimulant effects by facilitating synaptic actions of neurotransmitters such as dopamine and serotonin. It is also neurotoxic and broadly cytotoxic, leading to overdose deaths. We demonstrate that the cytotoxic actions of cocaine reflect selective enhancement of autophagy, a process that physiologically degrades metabolites and cellular organelles, and that uncontrolled autophagy can also lead to cell death. In brain cultures, cocaine markedly increases levels of LC3-II and depletes p62, both actions characteristic of autophagy. By contrast, cocaine fails to stimulate cell death processes reflecting parthanatos, monitored by cleavage of poly(ADP ribose)polymerase-1 (PARP-1), or necroptosis, assessed by levels of phosphorylated mixed lineage kinase domain-like protein. Pharmacologic inhibition of autophagy protects neurons against cocaine-induced cell death. On the other hand, inhibition of parthanatos, necroptosis, or apoptosis did not change cocaine cytotoxicity. Depletion of ATG5 or beclin-1, major mediators of autophagy, prevents cocaine-induced cell death. By contrast, depleting caspase-3, whose cleavage reflects apoptosis, fails to alter cocaine cytotoxicity, and cocaine does not alter caspase-3 cleavage. Moreover, depleting PARP-1 or RIPK1, key mediators of parthanatos and necroptosis, respectively, did not prevent cocaine-induced cell death. Autophagic actions of cocaine are mediated by the nitric oxide-glyceraldehyde-3-phosphate dehydrogenase signaling pathway. Thus, cocaine-associated autophagy is abolished by depleting GAPDH via shRNA; by the drug CGP3466B, which prevents GAPDH nitrosylation; and by mutating cysteine-150 of GAPDH, its site of nitrosylation. Treatments that selectively influence cocaine-associated autophagy may afford therapeutic benefit. PMID:26787898

  8. Suppressing the cytotoxicity of CuO nanoparticles by uptake of curcumin/BSA particles

    NASA Astrophysics Data System (ADS)

    Zhang, Wenjing; Jiang, Pengfei; Chen, Ying; Luo, Peihua; Li, Guanqun; Zheng, Botuo; Chen, Wei; Mao, Zhengwei; Gao, Changyou

    2016-05-01

    The adverse effects of metal-based nanoparticles on human beings and the environment have received extensive attention recently. It is urgently required to develop a simple and effective method to suppress the toxicity of metal-based nanomaterials. In this study, a hydrophobic antioxidant and a chelation agent curcumin (CUR) were encapsulated into bovine serum albumin (BSA) particles by a simple co-precipitation method, and followed by glutaraldehyde cross-linking. The CUR/BSA particles had an average size of 300 nm in diameter with a negatively charged surface and sustained curcumin release properties. The cellular uptake and cytotoxicity of CUR/BSA particles were followed on A549 cells, HepG2 cells and RAW264.7 cells. The CUR/BSA particles had higher intracellular accumulation and lower cytotoxicity compared with the free curcumin at the same drug concentration. The CUR/BSA particles could suppress the cytotoxicity generated by CuO nanoparticles as a result of decrease of both the intracellular reactive oxygen species (ROS) level and Cu2+ concentration, while the free curcumin did not show any obvious detoxicating effect. The detoxicating effects of CUR/BSA particles were further studied in an intratracheal instillation model in vivo, demonstrating significant reduction of toxicity and inflammatory response in rat lungs induced by CuO nanoparticles. The concept-proving study demonstrates the potential of the CUR/BSA particles in suppressing cytotoxicity of metal-based nanomaterials, which is a paramount requirement for the safe application of nanotechnology.

  9. Cell-Specific Oxidative Stress and Cytotoxicity after Wildfire Coarse Particulate Matter Instillation into Mouse Lung

    PubMed Central

    Williams, Keisha M.; Franzi, Lisa M.; Last, Jerold A.

    2012-01-01

    Our previous work has shown that coarse particulate matter (PM10-2.5) from wildfire smoke is more toxic to lung macrophages on an equal dose (by mass) basis than coarse PM isolated from normal ambient air, as evidenced by decreased numbers of macrophages in lung lavage fluid 6 and 24 hours after PM instillation into mouse lungs in vivo and by cytotoxicity to a macrophage cell line observed directly in vitro. We hypothesized that pulmonary macrophages from mice instilled with wildfire coarse PM would undergo more cytotoxicity than macrophages from controls, and that there would be an increase in oxidative stress in their lungs. Cytotoxicity was quantified as decreased viable macrophages and increased percentages of dead macrophages in the bronchoalveolar lavage fluid (BALF) of mice instilled with wildfire coarse PM. At one hour after PM instillation, we observed both decreased numbers of viable macrophages and increased dead macrophage percentages as compared to controls. An increase in free isoprostanes, an indicator of oxidative stress, from control values of 28.1±3.2 pg/mL to 83.9±12.2 pg/mL was observed a half-hour after PM instillation. By one hour after PM instillation, isoprostane values had returned to 30.4±7.6pg/mL, not significantly different from control concentrations. Lung sections from mice instilled with wildfire coarse PM showed rapid Clara cell responses, with decreased intracellular staining for the Clara cell secretory protein CCSP 1 hour after wildfire PM instillation. In conclusion, very rapid cytotoxicity occurs in pulmonary macrophages and oxidative stress responses are seen 0.5-1 hour after wildfire coarse PM instillation. These results define early cellular and biochemical events occurring in vivo and support the hypothesis that oxidative stress-mediated macrophage toxicity plays a key role in the initial response of the mouse lung to wildfire PM exposure. PMID:23142465

  10. Cell-specific oxidative stress and cytotoxicity after wildfire coarse particulate matter instillation into mouse lung.

    PubMed

    Williams, Keisha M; Franzi, Lisa M; Last, Jerold A

    2013-01-01

    Our previous work has shown that coarse particulate matter (PM(10-2.5)) from wildfire smoke is more toxic to lung macrophages on an equal dose (by mass) basis than coarse PM isolated from normal ambient air, as evidenced by decreased numbers of macrophages in lung lavage fluid 6 and 24hours after PM instillation into mouse lungs in vivo and by cytotoxicity to a macrophage cell line observed directly in vitro. We hypothesized that pulmonary macrophages from mice instilled with wildfire coarse PM would undergo more cytotoxicity than macrophages from controls, and that there would be an increase in oxidative stress in their lungs. Cytotoxicity was quantified as decreased viable macrophages and increased percentages of dead macrophages in the bronchoalveolar lavage fluid (BALF) of mice instilled with wildfire coarse PM. At 1hour after PM instillation, we observed both decreased numbers of viable macrophages and increased dead macrophage percentages as compared to controls. An increase in free isoprostanes, an indicator of oxidative stress, from control values of 28.1±3.2pg/mL to 83.9±12.2pg/mL was observed a half-hour after PM instillation. By 1hour after PM instillation, isoprostane values had returned to 30.4±7.6pg/mL, not significantly different from control concentrations. Lung sections from mice instilled with wildfire coarse PM showed rapid Clara cell responses, with decreased intracellular staining for the Clara cell secretory protein CCSP 1hour after wildfire PM instillation. In conclusion, very rapid cytotoxicity occurs in pulmonary macrophages and oxidative stress responses are seen 0.5-1hour after wildfire coarse PM instillation. These results define early cellular and biochemical events occurring in vivo and support the hypothesis that oxidative stress-mediated macrophage toxicity plays a key role in the initial response of the mouse lung to wildfire PM exposure. PMID:23142465

  11. Proteomic Analysis of Cellular Response Induced by Multi-Walled Carbon Nanotubes Exposure in A549 Cells

    PubMed Central

    Zhang, Xing; Jia, Zhenyu; Gao, Xiangjing; Jiang, Ying; Yan, Chunlan; Duerksen-Hughes, Penelope J.; Chen, Fanqing Frank; Li, Hongjuan; Zhu, Xinqiang; Yang, Jun

    2014-01-01

    The wide application of multi-walled carbon nanotubes (MWCNT) has raised serious concerns about their safety on human health and the environment. However, the potential harmful effects of MWCNT remain unclear and contradictory. To clarify the potentially toxic effects of MWCNT and to elucidate the associated underlying mechanisms, the effects of MWCNT on human lung adenocarcinoma A549 cells were examined at both the cellular and the protein level. Cytotoxicity and genotoxicity were examined, followed by a proteomic analysis (2-DE coupled with LC-MS/MS) of the cellular response to MWCNT. Our results demonstrate that MWCNT induces cytotoxicity in A549 cells only at relatively high concentrations and longer exposure time. Within a relatively low dosage range (30 µg/ml) and short time period (24 h), MWCNT treatment does not induce significant cytotoxicity, cell cycle changes, apoptosis, or DNA damage. However, at these low doses and times, MWCNT treatment causes significant changes in protein expression. A total of 106 proteins show altered expression at various time points and dosages, and of these, 52 proteins were further identified by MS. Identified proteins are involved in several cellular processes including proliferation, stress, and cellular skeleton organization. In particular, MWCNT treatment causes increases in actin expression. This increase has the potential to contribute to increased migration capacity and may be mediated by reactive oxygen species (ROS). PMID:24454774

  12. Mechanism of cellular response to nanoscale aggregates of small molecules

    NASA Astrophysics Data System (ADS)

    Kuang, Yi

    This dissertation research focused on the illustration of the molecular mechanism of cellular response to nanoscale aggregates formed by small molecules. There are five chapters in this dissertation. Chapter 1 summarizes the current research on the evaluation of cell response (i.e., biocompatibility/cytotoxicity) to small molecular hydrogelators. Chapter 2 describes an interesting phenomenon that supramolecular hydrogelators consisting of N-terminated dipeptides, which exhibit selective inhibitory effects against cancer cells. This study calls for the development of a new approach for identification of protein targets of the hydrogelators. Chapter 3 describes the evaluation of interactions between cytosol proteins of a mammalian cell line and morphologically different nanoscale molecular aggregates formed by small peptidic molecules. Chapter 4 describes the research on the mechanism of a type of molecular aggregates, which cluster short microtubules to prevent the growth of microtubule. This unprecedented mechanism of "self-assembly to interfere with self-organization " contributes to inhibiting growth of cancer cells in several mammalian cell based assays and a xenograft tumor mice model. At the end, Chapter 5 reports a novel supramolecular hydrogelator, which consists of fluorene and the pentapeptide epitope (TIGYG) of potassium ion (K+) channels, to self-assemble in water to form the tunable, hierarchical nanostructures dictated by the concentration of K+. In conclusion, this dissertation research demonstrates a new approach for investigating cellular target and molecular mechanism of self-assembled aggregates formed by small peptide derivatives based hydrogelators, which will make contribution to the development of supramolecular hydrogelators as biomaterials. Moreover, the differential cytotoxicity of molecular aggregates illustrated in this research promises a new direction for developing anti-cancer drug based on interactions between molecular aggregates and

  13. Role of the sodium-dependent phosphate co-transporters and of the phosphate complexes of uranyl in the cytotoxicity of uranium in LLC-PK{sub 1} cells

    SciTech Connect

    Muller, D. . E-mail: dany.muller@kcl.ac.uk; Houpert, P. . E-mail: pascale.houpert@irsn.fr; Cambar, J. . E-mail: marie-helene.napoli@cea.fr

    2006-07-15

    Although uranium is a well-characterized nephrotoxic agent, very little is known at the cellular and molecular level about the mechanisms underlying the uptake and toxicity of this element in proximal tubule cells. The aim of this study was thus to characterize the species of uranium that are responsible for its cytotoxicity and define the mechanism which is involved in the uptake of the cytotoxic fraction of uranium using two cell lines derived from kidney proximal (LLC-PK{sub 1}) and distal (MDCK) tubule as in vitro models. Treatment of LLC-PK{sub 1} cells with colchicine, cytochalasin D, concanavalin A and PMA increased the sodium-dependent phosphate co-transport and the cytotoxicity of uranium. On the contrary, replacement of the extra-cellular sodium with N-methyl-D-glucamine highly reduced the transport of phosphate and the cytotoxic effect of uranium. Uranium cytotoxicity was also dependent upon the extra-cellular concentration of phosphate and decreased in a concentration-dependent manner by 0.1-10 mM phosphonoformic acid, a competitive inhibitor of phosphate uptake. Consistent with these observations, over-expression of the rat proximal tubule sodium-dependent phosphate co-transporter NaPi-IIa in stably transfected MDCK cells significantly increased the cytotoxicity of uranium, and computer modeling of uranium speciation showed that uranium cytotoxicity was directly dependent on the presence of the phosphate complexes of uranyl UO{sub 2}(PO{sub 4}){sup -} and UO{sub 2}(HPO{sub 4}){sub aq}. Taken together, these data suggest that the cytotoxic fraction of uranium is a phosphate complex of uranyl whose uptake is mediated by a sodium-dependent phosphate co-transporter system.

  14. Synthetic biology in cellular immunotherapy

    PubMed Central

    Chakravarti, Deboki; Wong, Wilson W.

    2015-01-01

    The adoptive transfer of genetically engineered T cells with cancer-targeting receptors has shown tremendous promise for eradicating tumors in clinical trials. This form of cellular immunotherapy presents a unique opportunity to incorporate advanced systems and synthetic biology approaches to create cancer therapeutics with novel functions. Here, we first review the development of synthetic receptors, switches, and circuits to control the location, duration, and strength of T cell activity against tumors. In addition, we discuss the cellular engineering and genome editing of host cells (or the chassis) to improve the efficacy of cell-based cancer therapeutics, and to reduce the time and cost of manufacturing. PMID:26088008

  15. Global properties of cellular automata

    SciTech Connect

    Jen, E.

    1986-04-01

    Cellular automata are discrete mathematical systems that generate diverse, often complicated, behavior using simple deterministic rules. Analysis of the local structure of these rules makes possible a description of the global properties of the associated automata. A class of cellular automata that generate infinitely many aperoidic temporal sequences is defined,a s is the set of rules for which inverses exist. Necessary and sufficient conditions are derived characterizing the classes of ''nearest-neighbor'' rules for which arbitrary finite initial conditions (i) evolve to a homogeneous state; (ii) generate at least one constant temporal sequence.

  16. Cellular automaton for chimera states

    NASA Astrophysics Data System (ADS)

    García-Morales, Vladimir

    2016-04-01

    A minimalistic model for chimera states is presented. The model is a cellular automaton (CA) which depends on only one adjustable parameter, the range of the nonlocal coupling, and is built from elementary cellular automata and the majority (voting) rule. This suggests the universality of chimera-like behavior from a new point of view: Already simple CA rules based on the majority rule exhibit this behavior. After a short transient, we find chimera states for arbitrary initial conditions, the system spontaneously splitting into stable domains separated by static boundaries, some synchronously oscillating and the others incoherent. When the coupling range is local, nontrivial coherent structures with different periodicities are formed.

  17. Adaptive stochastic cellular automata: Applications

    NASA Astrophysics Data System (ADS)

    Qian, S.; Lee, Y. C.; Jones, R. D.; Barnes, C. W.; Flake, G. W.; O'Rourke, M. K.; Lee, K.; Chen, H. H.; Sun, G. Z.; Zhang, Y. Q.; Chen, D.; Giles, C. L.

    1990-09-01

    The stochastic learning cellular automata model has been applied to the problem of controlling unstable systems. Two example unstable systems studied are controlled by an adaptive stochastic cellular automata algorithm with an adaptive critic. The reinforcement learning algorithm and the architecture of the stochastic CA controller are presented. Learning to balance a single pole is discussed in detail. Balancing an inverted double pendulum highlights the power of the stochastic CA approach. The stochastic CA model is compared to conventional adaptive control and artificial neural network approaches.

  18. Cellular senescence in aging primates.

    PubMed

    Herbig, Utz; Ferreira, Mark; Condel, Laura; Carey, Dee; Sedivy, John M

    2006-03-01

    The aging of organisms is characterized by a gradual functional decline of all organ systems. Mammalian somatic cells in culture display a limited proliferative life span, at the end of which they undergo an irreversible cell cycle arrest known as replicative senescence. Whether cellular senescence contributes to organismal aging has been controversial. We investigated telomere dysfunction, a recently discovered biomarker of cellular senescence, and found that the number of senescent fibroblasts increases exponentially in the skin of aging baboons, reaching >15% of all cells in very old individuals. In addition, the same cells contain activated ataxia-telangiectasia mutated kinase and heterochromatinized nuclei, confirming their senescent status. PMID:16456035

  19. Cellular basis of Alzheimer's disease.

    PubMed

    Bali, Jitin; Halima, Saoussen Ben; Felmy, Boas; Goodger, Zoe; Zurbriggen, Sebastian; Rajendran, Lawrence

    2010-12-01

    Alzheimer's disease (AD) is the most common form of neurodegenerative disease. A characteristic feature of the disease is the presence of amyloid-β (Aβ) which either in its soluble oligomeric form or in the plaque-associated form is causally linked to neurodegeneration. Aβ peptide is liberated from the membrane-spanning -amyloid precursor protein by sequential proteolytic processing employing β- and γ-secretases. All these proteins involved in the production of Aβ peptide are membrane associated and hence, membrane trafficking and cellular compartmentalization play important roles. In this review, we summarize the key cellular events that lead to the progression of AD. PMID:21369424

  20. Comparison of cytotoxicity and wound healing effect of carboxymethylcellulose and hyaluronic acid on human corneal epithelial cells

    PubMed Central

    Lee, Jong Soo; Lee, Seung Uk; Che, Cheng-Ye; Lee, Ji-Eun

    2015-01-01

    AIM To investigate the cytotoxic effect on human corneal epithelial cells (HCECs) and the ability to faciliate corneal epithelial wound healing of carboxymethylcellulose (CMC) and hyaluronic acid (HA). METHODS HCECs were exposed to 0.5% CMC (Refresh plus®, Allergan, Irvine, California, USA) and 0.1% and 0.3% HA (Kynex®, Alcon, Seoul, Korea, and Hyalein mini®, Santen, Osaka, Japan) for the period of 30min, and 4, 12, and 24h. Methyl thiazolyl tetrazolium (MTT)-based calorimetric assay was performed to assess the metabolic activity of cellular proliferation and lactate dehydrogenase (LDH) leakage assay to assess the cytotoxicity. Apoptotic response was evaluated with flow cytometric analysis and fluorescence staining with Annexin V and propiodium iodide. Cellular morphology was evaluated by inverted phase-contrast light microscopy and electron microscopy. The wound widths were measured 24h after confluent HCECs were scratch wounded. RESULTS The inhibitory effect of human corneal epithelial proliferation and cytotoxicity showed the time-dependent response but no significant effect. Apoptosis developed in flow cytometry and apoptotic cells were demonstrated in fluorescent micrograph. The damaged HCECs were detached from the bottom of the dish and showed the well-developed vacuole formations. Both CMC and HA stimulated reepithehlialization of HCECs scratched, which were more observed in CMC. CONCLUSION CMC and HA, used in artificial tear formulation, could be utilized without any significant toxic effect on HCECs. Both significantly stimulated HCEC reepithelialization of corneal wounds. PMID:25938030

  1. Involvement of oxidative stress and mitochondrial/lysosomal cross-talk in olanzapine cytotoxicity in freshly isolated rat hepatocytes.

    PubMed

    Eftekhari, Aziz; Azarmi, Yadollah; Parvizpur, Alireza; Eghbal, Mohammad Ali

    2016-04-01

    1. Olanzapine (OLZ) is a widely used atypical antipsychotic agent for the treatment of schizophrenia and other disorders. Serious hepatotoxicity and elevated liver enzymes have been reported in patients receiving OLZ. However, the cellular and molecular mechanisms of the OLZ hepatotoxicity are unknown. 2. In this study, the cytotoxic effect of OLZ on freshly isolated rat hepatocytes was assessed. Our results showed that the cytotoxicity of OLZ in hepatocytes is mediated by overproduction of reactive oxygen species (ROS), mitochondrial potential collapse, lysosomal membrane leakiness, GSH depletion and lipid peroxidation preceding cell lysis. All the aforementioned OLZ-induced cellular events were significantly (p < 0.05) prevented by ROS scavengers, antioxidants, endocytosis inhibitors and adenosine triphosphate generators. Also, the present results demonstrated that CYP450 is involved in OLZ-induced oxidative stress and cytotoxicity mechanism. 3. It is concluded that OLZ hepatotoxicity is associated with both mitochondrial/lysosomal involvement following the initiation of oxidative stress in hepatocytes. PMID:26364812

  2. Investigation of an SPR biosensor for determining the influence of connexin 43 expression on the cytotoxicity of cisplatin.

    PubMed

    Wang, Yijia; Zhang, Shiwu; Zhang, Chunze; Zhao, Zhenying; Zheng, Xiaoli; Xue, Lihua; Liu, Jun; Yuan, X-C

    2016-05-23

    The real-time and label free detection abilities of surface plasmon resonance (SPR) biosensors provide a way of evaluating the influence of some genes' expression on anti-tumor drug cytotoxicity. However, studies in this field are lacking. Connexin 43 is a tumor suppressor gene and the mechanism of its effect in cisplatin cytotoxicity is still unclear. A phase SPR biosensor was used to determine the influence of connexin 43 expression on cisplatin cytotoxicity in three cancer cell lines. The results showed that the SPR signal curves have two stages. In the first hour, the SPR signal shows dramatic changes which are related to connexin 43 expression. In the subsequent stage, the SPR signal slowly declines and is related to apoptosis. Comparison of SPR measurements from several conventional biological assays showed that connexin 43 expression can affect cellular response to cisplatin in the period of oxidative stress, and results in the cells being more sensitive to cisplatin. The conclusion is further confirmed by long-term SPR measurement results and cellular morphological changes. PMID:27140873

  3. Cytotoxic activities of several geranyl-substituted flavanones.

    PubMed

    Smejkal, Karel; Svacinová, Jana; Slapetová, Tereza; Schneiderová, Kristýna; Dall'acqua, Stefano; Innocenti, Gabbriella; Závalová, Veronika; Kollár, Peter; Chudík, Stanislav; Marek, Radek; Julínek, Ondrej; Urbanová, Marie; Kartal, Murat; Csöllei, Marek; Dolezal, Karel

    2010-04-23

    Nine geranylated flavanones isolated from the fruits of Paulownia tomentosa (4-12) and two from the roots of Morus alba (13 and 14) were examined for cytotoxicity to selected human cancer cell lines and normal human fibroblasts. Cytotoxicity was determined in vitro using a calcein AM cytotoxicity assay. Cytotoxicity for the THP-1 monocytic leukemia cell line was tested using erythrosin B cell staining. The geranylated compounds tested were compared with the known simple flavanone standards taxifolin (1), naringenin (2), and hesperetin (3) and with the standard anticancer drugs olomoucine II, diaziquone, and oxaliplatin and the antineoplastic compound camptothecin, and showed different levels of cytotoxicity. The effects of structural changes on cytotoxic activity, including geranyl substitution of the flavanone skeleton and the oxidation pattern of ring B of the flavanones, are discussed. PMID:20192247

  4. Lectin-dependent neutrophil-mediated cytotoxicity. I. Characteristics.

    PubMed Central

    Simchowitz, L; Schur, P H

    1976-01-01

    Isolated normal human peripheral neutrophils became cytotoxic to chicken red blood cells (CRBC) in the presence of phytohaemagglutinin (PHA) and concanavalin A (Con A), a phenomenon which we have termed lectin-dependent neutrophilmediated cytotoxicity (LDNMC). Substantial cytotoxicity could be demonstrated by 1 h of incubation at 37 degrees. Isolated human peripheral lymphocytes were not cytotoxic to CRBC in the presence of these lectins, even after 18 h of incubation. Both PHA and Con A exhibited dose responses over a wide concentration range and displayed progressive, time-dependent cytotoxicity. Cytotoxicity for both PHA and Con A was greater at 37 degrees than at 22 degrees, and was undetectable at 4 degrees. CRBC as target cells were much more readily lysed than either sheep or human erythrocytes. Erythrophagocytosis did not appear to play a role. Images Figure 1 PMID:955680

  5. Cytotoxic Effects of Fucoidan Nanoparticles against Osteosarcoma

    PubMed Central

    Kimura, Ryuichiro; Rokkaku, Takayoshi; Takeda, Shinji; Senba, Masachika; Mori, Naoki

    2013-01-01

    In this study, we analyzed the size-dependent bioactivities of fucoidan by comparing the cytotoxic effects of native fucoidan and fucoidan lipid nanoparticles on osteosarcoma in vitro and in vivo. In vitro experiments indicated that nanoparticle fucoidan induced apoptosis of an osteosarcoma cell line more efficiently than native fucoidan. The more potent effects of nanoparticle fucoidan, relative to native fucoidan, were confirmed in vivo using a xenograft osteosarcoma model. Caco-2 cell transport studies showed that permeation of nanoparticle fucoidan was higher than native fucoidan. The higher bioactivity and superior bioavailability of nanoparticle fucoidan could potentially be utilized to develop novel therapies for osteosarcoma. PMID:24177673

  6. Cytotoxic constituents of the lichen Diploicia canescens.

    PubMed

    Millot, Marion; Tomasi, Sophie; Studzinska, Elisabeth; Rouaud, Isabelle; Boustie, Joël

    2009-12-01

    A new diphenyl ether (1), along with 12 known compounds, was isolated from the lichen Diploicia canescens. The structure of compound 1 was elucidated by spectroscopic data analysis, and the biosynthetic origin of this product is discussed. Secalonic acids B (7), D (8), and F (9) were isolated for the first time from D. canescens. The cytotoxic activities of 1-3, 6-8, and 10 against the B16 murine melanoma and HaCaT human keratinocyte cell lines were evaluated. PMID:19919064

  7. Cytotoxic Polyisoprenyl Benzophenonoids from Garcinia subelliptica

    PubMed Central

    Zhang, Li-Jie; Chiou, Chun-Tang; Cheng, Jing-Jy; Huang, Hui-Chi; Yang Kuo, Li-Ming; Liao, Chia-Chin; Bastow, Kenneth F.; Lee, Kuo-Hsiung; Kuo, Yao-Haur

    2010-01-01

    Six new polyisoprenyl benzophenonoids, (±)-garcinialiptone A (1, 2), garcinialiptone B (3), (−)-cycloxanthochymol (4), garcinialiptone C (5), and garcinialiptone D (6), along with three known compounds, xanthochymol (7), isoxanthochymol (8), and cycloxanthochymol (9), were isolated from the fruits of Garcinia subelliptica. The structures of 1–6 were elucidated by spectroscopic analysis. Biological evaluation showed that all compounds 1–9 exhibited cytotoxic activity against a small panel of human tumor cell lines (A549, DU145, KB, vincristine-resistant KB). PMID:20232858

  8. Cytotoxic phorbol esters of Croton tiglium.

    PubMed

    Zhang, Xiao-Long; Wang, Lun; Li, Fu; Yu, Kai; Wang, Ming-Kui

    2013-05-24

    Chemical investigation of the seeds of Croton tiglium afforded eight new phorbol diesters (three phorbol diesters, 1-3, and five 4-deoxy-4α-phorbol diesters, 4-8), together with 11 known phorbol diesters (nine phorbol diesters, 9-17, and two 4-deoxy-4α-phorbol diesters, 18 and 19). The structures of compounds 1-8 were determined by spectroscopic data information and chemical degradation experiments. The cytotoxic activities of the phorbol diesters were evaluated against the SNU387 hepatic tumor cell line, and compound 3 exhibited the most potent activity (IC50 1.2 μM). PMID:23701597

  9. New Cytotoxic Tigliane Diterpenoids from Croton caudatus.

    PubMed

    Chen, Ying-Ying; Yang, Kun-Xian; Yang, Xing-Wei; Khan, Afsar; Liu, Lu; Wang, Bei; Zhao, Yun-Li; Liu, Ya-Ping; Li, Yan; Luo, Xiao-Dong

    2016-05-01

    Three new tigliane-type diterpenoids were isolated from the methanolic extract of the twigs and leaves of Croton caudatus, trivially named crotusins A-C (1-3). The structures of compounds 1-3 were elucidated on the basis of extensive spectral methods. These new compounds were highly oxygenated and heavily substituted. Cytotoxic activity against five human tumor cell lines was assessed for compounds 1-3 of which compound 3 showed significant inhibitory activity with IC50 values ranging from 0.49 to 4.19 µM against these cells, while crotusins A and B exhibited moderate activity. PMID:27002392

  10. Synthesis and cytotoxic evaluation of combretafurazans.

    PubMed

    Tron, Gian Cesare; Pagliai, Francesca; Del Grosso, Erika; Genazzani, Armando A; Sorba, Giovanni

    2005-05-01

    Combretastatin A-4 is an antitumoral and antitubulin agent that is active only in its cis configuration. In the present manuscript, we have synthesized cis-locked combretastatins embodying a furazan ring (combretafurazans). To achieve this, we have developed a new strategy that exploits the dehydration of vicinal dioximes using the Mitsunobu reaction. Among the advantages of following such a strategy are the mild conditions used for the construction of the diarylfurazan derivatives, allowing for the presence of highly functionalized substrates and deactivated aromatic rings. Combretafurazans are more potent in vitro cytotoxic compounds compared to combretastatins in neuroblastoma cells, yet maintaining similar structure-activity relationship and pharmacodynamic profiles. PMID:15857132

  11. Protein corona mitigates the cytotoxicity of graphene oxide by reducing its physical interaction with cell membrane

    NASA Astrophysics Data System (ADS)

    Duan, Guangxin; Kang, Seung-Gu; Tian, Xin; Garate, Jose Antonio; Zhao, Lin; Ge, Cuicui; Zhou, Ruhong

    2015-09-01

    Many recent studies have shown that the way nanoparticles interact with cells and biological molecules can vary greatly in the serum-containing or serum-free culture medium. However, the underlying molecular mechanisms of how the so-called ``protein corona'' formed in serum medium affects nanoparticles' biological responses are still largely unresolved. Thus, it is critical to understand how absorbed proteins on the surfaces of nanoparticles alter their biological effects. In this work, we have demonstrated with both experimental and theoretical approaches that protein BSA coating can mitigate the cytotoxicity of graphene oxide (GO) by reducing its cell membrane penetration. Our cell viability and cellular uptake experiments showed that protein corona decreased cellular uptake of GO, thus significantly mitigating the potential cytotoxicity of GO. The electron microscopy images also confirmed that protein corona reduced the cellular morphological damage by limiting GO penetration into the cell membrane. Further molecular dynamics (MD) simulations validated the experimental results and revealed that the adsorbed BSA in effect weakened the interaction between the phospholipids and graphene surface due to a reduction of the available surface area plus an unfavorable steric effect, thus significantly reducing the graphene penetration and lipid bilayer damaging. These findings provide new insights into the underlying molecular mechanism of this important graphene protein corona interaction with cell membranes, and should have implications in future development of graphene-based biomedical applications.Many recent studies have shown that the way nanoparticles interact with cells and biological molecules can vary greatly in the serum-containing or serum-free culture medium. However, the underlying molecular mechanisms of how the so-called ``protein corona'' formed in serum medium affects nanoparticles' biological responses are still largely unresolved. Thus, it is critical

  12. CALOTROPIN, A CYTOTOXIC PRINCIPLE ISOLATED FROM ASCLEPIAS CURASSAVICA L.

    PubMed

    KUPCHAN, S M; KNOX, J R; KELSEY, J E; SAENZRENAULD, J A

    1964-12-25

    An alcoholic extract of Asclepias curassavica L., a plant widely used in folk medicine for treating cancer and warts, shows cytotoxic activity when tested in vitro against cells derived from human carcinoma of the nasopharynx. Systematic fractionation of the extract has led to isolation and characterization of calotropin as a cytotoxic principle. Calotropin is similar in structure to two cardiac glycosides recently shown to be responsible for the cytotoxicity of Apocynum cannabinum L. PMID:14224519

  13. Differential cytotoxicity of long-chain bases for human oral gingival epithelial keratinocytes, oral fibroblasts, and dendritic cells.

    PubMed

    Mehalick, Leslie A; Poulsen, Christopher; Fischer, Carol L; Lanzel, Emily A; Bates, Amber M; Walters, Katherine S; Cavanaugh, Joseph E; Guthmiller, Janet M; Johnson, Georgia K; Wertz, Philip W; Brogden, Kim A

    2015-12-01

    Long-chain bases, found in the oral cavity, have potent antimicrobial activity against oral pathogens. In an article associated with this dataset, Poulson and colleagues determined the cytotoxicities of long-chain bases (sphingosine, dihydrosphingosine, and phytosphingosine) for human oral gingival epithelial (GE) keratinocytes, oral gingival fibroblasts (GF), dendritic cells (DC), and squamous cell carcinoma (SCC) cell lines [1]. Poulson and colleagues found that GE keratinocytes were more resistant to long-chain bases as compared to GF, DC, and SCC cell lines [1]. In this study, we assess the susceptibility of DC to lower concentrations of long chain bases. 0.2-10.0 µM long-chain bases and GML were not cytotoxic to DC; 40.0-80.0 µM long-chain bases, but not GML, were cytotoxic for DC; and 80.0 µM long-chain bases were cytotoxic to DC and induced cellular damage and death in less than 20 mins. Overall, the LD50 of long-chain bases for GE keratinocytes, GF, and DC were considerably higher than their minimal inhibitory concentrations for oral pathogens, a finding important to pursuing their future potential in treating periodontal and oral infections. PMID:26550599

  14. ACAT1 deletion in murine macrophages associated with cytotoxicity and decreased expression of collagen type 3A1

    SciTech Connect

    Rodriguez, Annabelle . E-mail: arodrig5@jhmi.edu; Ashen, M. Dominique; Chen, Edward S.

    2005-05-27

    In contrast to some published studies of murine macrophages, we previously showed that ACAT inhibitors appeared to be anti-atherogenic in primary human macrophages in that they decreased foam cell formation without inducing cytotoxicity. Herein, we examined foam cell formation and cytotoxicity in murine ACAT1 knockout (KO) macrophages in an attempt to resolve the discrepancies. Elicited peritoneal macrophages from normal C57BL6 and ACAT1 KO mice were incubated with DMEM containing acetylated LDL (acLDL, 100 {mu}g protein/ml) for 48 h. Cells became cholesterol enriched and there were no differences in the total cholesterol mass. Esterified cholesterol mass was lower in ACAT1 KO foam cells compared to normal macrophages (p < 0.04). Cytotoxicity, as measured by the cellular release of [{sup 14}C]adenine from macrophages, was approximately 2-fold greater in ACAT1 KO macrophages as compared to normal macrophages (p < 0.0001), and this was independent of cholesterol enrichment. cDNA microarray analysis showed that ACAT1 KO macrophages expressed substantially less collagen type 3A1 (26-fold), which was confirmed by RT-PCR. Total collagen content was also significantly reduced (57%) in lung homogenates isolated from ACAT1 KO mice (p < 0.02). Thus, ACAT1 KO macrophages show biochemical changes consistent with increased cytotoxicity and also a novel association with decreased expression of collagen type 3A1.

  15. In vitro genotoxicity and cytotoxicity in murine fibroblasts exposed to EDTA, NaOCl, MTAD and citric acid.

    PubMed

    Marins, Juliana Soares Roter; Sassone, Luciana Moura; Fidel, Sandra Rivera; Ribeiro, Daniel Araki

    2012-01-01

    The aim of the present study was to evaluate the capacity of some root canal irrigants to induce genetic damage and/or cellular death in vitro. Murine fibroblast cells were exposed to ethylenediaminetetraacetic acid (EDTA), sodium hypochlorite (NaOCl), MTAD™ and citric acid in increasing concentrations for 3 h at 37ºC. The negative control group was treated with vehicle control (phosphate buffer solution - PBS) for 3 h at 37°C, and the positive control group was treated with methylmetanesulfonate, 1 μM. for 3 h at 37°C. Cytotoxicity was assessed by the trypan blue test and genotoxicity was evaluated by the single cell gel (comet) assay. The results showed that exposure to 2.5% and 5% NaOCl and 8.5% citric acid resulted in a significant cytotoxic effect. NaOCl, EDTA and citric acid did not produce genotoxic effects with respect to the comet assay data for all evaluated concentrations. Although MTAD was not a cytotoxic agent, it showed significant genotoxic effects at all tested concentrations (ANOVA and Tukey's test; p<0.05). NaOCl, EDTA and citric acid were found to be cytotoxic in a dose-dependent manner, but they were not genotoxic. MTAD did not cause cell death, but presented genotoxic effects. PMID:23306229

  16. FCRL6 distinguishes mature cytotoxic lymphocytes and is upregulated in patients with B cell chronic lymphocytic leukemia

    PubMed Central

    Schreeder, Daniel M.; Pan, Jicun; Li, Fu Jun; Vivier, Eric; Davis, Randall S.

    2009-01-01

    Fc receptor-like 6 (FCRL6), the most recently characterized member of the FCRL family, is a cell surface glycoprotein with tyrosine-based regulatory potential. An extensive survey of human hematopoietic tissues disclosed that FCRL6 expression by NK and T cell subpopulations increases as a function of differentiation and is remarkably restricted to mature lymphocytes with cytotoxic capability. In particular, FCRL6 distinguishes perforin-expressing CD56dim NK cells, Vδ1+ and Vδ2+ γδ T cells, effector and effector memory CD8+ T cells, and rare cytotoxic CD4+ T cells in adult tissues. Analysis of this receptor in B cell chronic lymphocytic leukemia (CLL) was also performed. FCRL6 was found to mark significantly expanded populations of cytotoxic CD8+ T, CD4+ T, and NK cells in patients with CLL. Despite sequence homology with the known Fc receptors for IgG and IgE, FCRL6 did not bind immunoglobulin. Although FCRL6 can be tyrosine-phosphorylated, its antibody-mediated ligation was unable to influence cellular activation. Collectively these results demonstrate that FCRL6 is a distinct indicator of cytotoxic effector lymphocytes that is upregulated in diseases characterized by chronic immune stimulation. PMID:18991291

  17. Wrinkling in Cellular Structured Composites

    NASA Astrophysics Data System (ADS)

    Kaynia, Narges; Li, Yaning; Boyce, Mary C.

    2013-03-01

    Many structured composites found in nature possess undulating and wrinkled interfacial layers that regulate mechanical, chemical, acoustic, adhesive, thermal, electrical and optical functions of the material. This research focused on the formation of wrinkling patterns in cellular structured composites and the effect of the wrinkling pattern on the overall structural response. The cellular composites consisted of stiffer interfacial layers constructing a network submerged in a soft matrix. Analytical and finite element models were developed to capture various aspects of the wrinkling mechanism. The characteristics of the undulation patterns and the instability modes were investigated as functions of model geometry and material composition. Mechanical experiments were designed to further explore the modeling results. The cellular composite samples were fabricated by using different types of elastomers and by varying the geometry and the material properties. The experimental and numerical results were consistent with the analytical predictions. The results in this research improve understanding of the mechanisms governing the undulation pattern formation in cellular composites and can be used to enable on-demand tunability of different functions to provide, among others, active control of wave propagation, mechanical stiffness and deformation, and material swelling and growth.

  18. Cellular Automata and the Humanities.

    ERIC Educational Resources Information Center

    Gallo, Ernest

    1994-01-01

    The use of cellular automata to analyze several pre-Socratic hypotheses about the evolution of the physical world is discussed. These hypotheses combine characteristics of both rigorous and metaphoric language. Since the computer demands explicit instructions for each step in the evolution of the automaton, such models can reveal conceptual…

  19. High content analysis at single cell level identifies different cellular responses dependent on nanomaterial concentrations

    NASA Astrophysics Data System (ADS)

    Manshian, Bella B.; Munck, Sebastian; Agostinis, Patrizia; Himmelreich, Uwe; Soenen, Stefaan J.

    2015-09-01

    A mechanistic understanding of nanomaterial (NM) interaction with biological environments is pivotal for the safe transition from basic science to applied nanomedicine. NM exposure results in varying levels of internalized NM in different neighboring cells, due to variances in cell size, cell cycle phase and NM agglomeration. Using high-content analysis, we investigated the cytotoxic effects of fluorescent quantum dots on cultured cells, where all effects were correlated with the concentration of NMs at the single cell level. Upon binning the single cell data into different categories related to NM concentration, this study demonstrates, for the first time, that quantum dots activate both cytoprotective and cytotoxic mechanisms, resulting in a zero net result on the overall cell population, yet with significant effects in cells with higher cellular NM levels. Our results suggest that future NM cytotoxicity studies should correlate NM toxicity with cellular NM numbers on the single cell level, as conflicting mechanisms in particular cell subpopulations are commonly overlooked using classical toxicological methods.

  20. In vitro cytotoxicity of metallic ions released from dental alloys.

    PubMed

    Milheiro, Ana; Nozaki, Kosuke; Kleverlaan, Cornelis J; Muris, Joris; Miura, Hiroyuki; Feilzer, Albert J

    2016-05-01

    The cytotoxicity of a dental alloy depends on, but is not limited to, the extent of its corrosion behavior. Individual ions may have effects on cell viability that are different from metals interacting within the alloy structure. We aimed to investigate the cytotoxicity of individual metal ions in concentrations similar to those reported to be released from Pd-based dental alloys on mouse fibroblast cells. Metal salts were used to prepare seven solutions (concentration range 100 ppm-1 ppb) of the transition metals, such as Ni(II), Pd(II), Cu(II), and Ag(I), and the metals, such as Ga(III), In(III), and Sn(II). Cytotoxicity on mouse fibroblasts L929 was evaluated using the MTT assay. Ni, Cu, and Ag are cytotoxic at 10 ppm, Pd and Ga at 100 ppm. Sn and In were not able to induce cytotoxicity at the tested concentrations. Transition metals were able to induce cytotoxic effects in concentrations similar to those reported to be released from Pd-based dental alloys. Ni, Cu, and Ag were the most cytotoxic followed by Pd and Ga; Sn and In were not cytotoxic. Cytotoxic reactions might be considered in the etiopathogenesis of clinically observed local adverse reactions. PMID:25549610

  1. Curcumin-cyclodextrin encapsulated chitosan nanoconjugates with enhanced solubility and cell cytotoxicity.

    PubMed

    Popat, Amirali; Karmakar, Surajit; Jambhrunkar, Siddharth; Xu, Chun; Yu, Chengzhong

    2014-05-01

    Curcumin (CUR), a naturally derived anti-cancer cocktail is arguably the most widely studied neutraceutical. Despite a lot of promises, it is yet to reach the market as an active anti-cancer formulation. In the present study, we have prepared highly soluble (3 mg/ml) CUR-γ-hydroxypropyl cyclodextrin (CUR-CD) hollow spheres. CUR-CD hollow spheres were prepared by a novel and scalable spray drying method. CUR-CD was then encapsulated into positively charged biodegradable chitosan (CUR-CD-CS) nanoparticles. The CUR-CD-CS nanoparticles were characterised by TEM, SEM, DLS, drug loading and in vitro release. We tested the efficacy of these CUR-CD-CS nanoparticles in SCC25 cell lines using MTT assay and investigated its cellular uptake mechanism. We also studied Oligo DNA loading in CUR-CD-CS nanoparticles and its delivery via confocal imaging and FACS analysis. Our results demonstrated that CUR-CD-CS nanoparticles showed superior in vitro release performance and higher cytotoxicity in SCC25 cell line amongst all tested formulations. The cytotoxicity results were corroborated by cell cycle analysis and apoptosis test, showing nearly 100% apoptotic cell death in the case of CUR-CD-CS nanoparticles. Compared to CS nanoparticles, CS-CD nanoformulation showed higher cellular delivery of Cy3-Oligo DNA which was tested quantitatively using flowcytometry analysis, indicating that CD not only enhanced CUR solubility but also boosted the cellular uptake. Our study shows that rationally designed bio-degradable natural biomaterials have great potential as next generation nano-carriers for hydrophobic drug delivery such as CUR with potential of dual drug-gene delivery. PMID:24698148

  2. Catalase ameliorates polychlorinated biphenyl-induced cytotoxicity in non-malignant human breast epithelial cells

    PubMed Central

    Venkatesha, Venkatasubbaiah A.; Venkataraman, Sujatha; Sarsour, Ehab H.; Kalen, Amanda L.; Buettner, Garry R.; Robertson, Larry W.; Lehmler, Hans-Joachim; Goswami, Prabhat C.

    2008-01-01

    Polychlorinated biphenyls (PCBs) are environmental chemical contaminants believed to adversely affect cellular processes. We investigated the hypothesis that PCB-induced changes in the levels of cellular reactive oxygen species (ROS) induce DNA damage resulting in cytotoxicity. Exponentially growing cultures of human non-malignant breast epithelial cells (MCF10A) were incubated with PCBs for 3 days and assayed for cell number, ROS levels, DNA damage, and cytotoxicity. Exposure to 2,2',4,4',5,5'-hexachlorobiphenyl (PCB153) or 2-(4-chlorophenyl)benzo-1,4-quinone (4-Cl-BQ), a metabolite of 4-chlorobiphenyl (PCB3) significantly decreased cell number, MTS reduction, and increased the percentage of cells with sub G1 DNA content. Results from electron paramagnetic resonance (EPR) spectroscopy showed a 4-fold increase in the steady-state levels of ROS, which was suppressed in cells pre-treated with catalase. EPR measurements in cells treated with 4-Cl-BQ detected the presence of a semiquinone radical, suggesting that the increased levels of ROS could be due to the redox-cycling of 4-Cl-BQ. A dose-dependent increase in micronuclei frequency was observed in PCB-treated cells, consistent with an increase in histone 2AX-phosphorylation. Treatment of cells with catalase blunted the PCB-induced increase in micronuclei frequency and H2AX phosphorylation that was consistent with an increase in cell survival. Our results demonstrate a PCB-induced increase in cellular levels of ROS causing DNA damage, resulting in cell killing. PMID:18691649

  3. Cytotoxicity of Cheese and Cheddar Cheese food flavorings on Allim cepa L root meristems.

    PubMed

    Moura, A G; Santana, G M; Ferreira, P M P; Sousa, J M C; Peron, A P

    2016-06-01

    Despite their great importance for the food industry, flavorings, in general, raise a number of questions regarding their cytotoxicity, mutagenicity and carcinogenicity, since, in the literature, there are few studies found evaluating the toxicity on the systemic and cellular level, of these chemical compounds. The root meristems of Allium cepa (onion) are widely used for the assessment of toxicity of chemical compounds of interest. Thus, this study aimed to evaluate, in A. cepa meristematic cells, individually and in combination at the cellular level, the toxicity of synthetic Cheese and Cheddar Cheese food flavorings, identical to the natural, at doses of 1.0 and 2.0 mL, at exposure times of 24 and 48 hours. In combination we used 0.5 mL of Cheese flavor associated with 0.5 mL of Cheddar flavor; and 1.0 mL of Cheese flavor associated with 1.0 mL of Cheddar flavor, at exposure times of 24 and 48 hours. For these evaluations, we used groups of five onion bulbs, which were first embedded in distilled water and then transferred to their respective doses. The root tips were collected and fixed in acetic acid (3:1) for 24 hours. The slides were prepared by crushing and were stained with 2% acetic orcein. Cells were analyzed throughout the cell cycle, totaling 5,000 for each control and exposure time. The mitotic indices calculated and cellular aberrations observed were subjected to statistical analysis using the chi-square test (p <0.05). No chromosomal abnormalities nor those of mitotic spindle were observed for the treatments performed. The results, both individually and in combination, showed that the flavorings under study significantly reduced the cell division rate of the test system cells used. Therefore, under the conditions studied, the two flavorings were cytotoxic. PMID:26959949

  4. MULTIVALENT DISPLAY OF PENDANT PRO-APOPTOTIC PEPTIDES INCREASES CYTOTOXIC ACTIVITY

    PubMed Central

    Chu, David S.H.; Bocek, Michael J.; Shi, Julie; Ta, Anh; Ngambenjawong, Chayanon; Rostomily, Robert C.; Pun, Suzie H.

    2015-01-01

    Several cationic antimicrobial peptides have been investigated as potential anti-cancer drugs due to their demonstrated selective toxicity towards cancer cells relative to normal cells. For example, intracellular delivery of KLA, a pro-apoptotic peptide, results in toxicity against a variety of cancer cell lines; however, the relatively low activity and small size leads to rapid renal excretion when applied in vivo, limiting its therapeutic potential. In this work, apoptotic peptide-polymer hybrid materials were developed to increase apoptotic peptide activity via multivalent display. Multivalent peptide materials were prepared with comb-like structure by RAFT copolymerization of peptide macromonomers with N-(2-hydroxypropyl) methacrylamide (HPMA). Polymers displayed a GKRK peptide sequence for targeting p32, a protein often overexpressed on the surface of cancer cells, either fused with or as a comonomer to a KLA macromonomer. In three tested cancer cell lines, apoptotic polymers were significantly more cytotoxic than free peptides as evidenced by an order of magnitude decrease in IC50 values for the polymers compared to free peptide. The uptake efficiency and intracellular trafficking of one polymer construct was determined by radiolabeling and subcellular fractionation. Despite their more potent cytotoxic profile, polymeric KLA constructs have poor cellular uptake efficiency (<1%). A significant fraction (20%) of internalized constructs localize with intact mitochondrial fractions. In an effort to increase cellular uptake, polymer amines were converted to guanidines by reaction with O-methylisourea. Guanidinylated polymers disrupted function of isolated mitochondria more than their lysine-based analogs, but overall toxicity was decreased, likely due to inefficient mitochondrial trafficking. Thus, while multivalent KLA polymers are more potent than KLA peptides, these materials can be substantially improved by designing next generation materials with improved

  5. Preparing cytotoxic agents in an isolator.

    PubMed

    Favier, M; Hansel, S; Bressolle, F

    1993-11-01

    The design of an isolator and its use by an oncology satellite pharmacy for preparing cytotoxic drugs are described. The isolator (Iso Concept, Boulogne, France) is a totally enclosed ventilated biological-safety cabinet of class III polyvinyl chloride (PVC) with positive air pressure, a half-suit with a rotating seal, and attached neoprene gloves. There are three work-stations, one for the half-suit and two along one side of the isolator. The ventilation and air filtration system consists of one entry pipe with a full ventilation-filtration box fitted with one prefilter, one blower, one ball valve, one high-efficiency particulate air (HEPA) filter, one airtight nipple connected to an automatic sterilizer, alarms, and one exhaust pipe protected by a HEPA filter. The air lock consists of a rigid, transparent Plexiglas pass-through. The chamber is sterilized with heated compressed air mixed with 3.5% peracetic acid. Maintenance includes regular changing of gloves and HEPA filters; checking of the integrity of the PVC, half-suit, and gloves; and washing and decontamination procedures. Preparation of cytotoxics is planned in advance with prescription data and manufacturing sheets. In the half-suit, a pharmacy technician reads the label, supervises preparation of the sterile admixture, and writes a label. The operators on the side of the unit read the manufacturing sheet and prepare the dose identified by the label.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8266957

  6. Cytotoxic isoferulic acidamide from Myricaria germanica (Tamaricaceae)

    PubMed Central

    Nawwar, Mahmoud A.; Swilam, Noha F.; Hashim, Amani N.; Al-Abd, Ahmed M.; Abdel-Naim, Ashraf B.; Lindequist, Ulrike

    2013-01-01

    Tamgermanitin, a unique N-trans-Isoferuloyltyramine, together with the hitherto unknown polyphenolics, 2,4-di-O-galloyl-(α/β)-glucopyranose and kaempferide 3,7-disulphate have been isolated from the leaf aqueous ethanol extract of the false tamarisk, Myricaria germanica DESV. In addition, 18 known phenolics were also separated and characterized. All structures were elucidated on the basis of detailed analysis of 1D- 1H and 13C NMR, COSY, HSQC, HMBC and HRFTESIMS spectral data. The extract, its chromatographic column fractions and the isolated isoferuloyltyramine, tamgermanetin demonstrated potential cytotoxic effect against three different tumor cell lines, namely liver (Huh-7), breast (MCF-7) and prostate (PC-3). The IC50''s were found to be substantially low with low-resistance possibility. DNA flow-cytometic analysis indicated that column fractions and tamgermanetin enhanced pre-G apoptotic fraction. Both materials showed inhibiting activity against PARP enzyme activity. In conclusion, we report the isolation and identification of a novel compound, tamgermanitin, from the aqueous ethanol extract of Myricaria germanica leaves. Further, different fractions of the extract and tamgermanitin exhibit potent cytotoxic activities which warrant further investigations. PMID:23123452

  7. Study of Cytotoxic Effects of Benzonitrile Pesticides

    PubMed Central

    Lovecka, Petra; Thimova, Marketa; Grznarova, Petra; Lipov, Jan; Knejzlik, Zdenek; Stiborova, Hana; Nindhia, Tjokorda Gde Tirta; Demnerova, Katerina; Ruml, Tomas

    2015-01-01

    The benzonitrile herbicides bromoxynil, chloroxynil, dichlobenil, and ioxynil have been used actively worldwide to control weeds in agriculture since 1970s. Even though dichlobenil is prohibited in EU since 2008, studies addressing the fate of benzonitrile herbicides in the environment show that some metabolites of these herbicides are very persistent. We tested the cytotoxic effects of benzonitrile herbicides and their microbial metabolites using two human cell lines, Hep G2 and HEK293T, representing liver and kidneys as potential target organs in humans. The cell viability and proliferation were determined by MTT test and RTCA DP Analyzer system, respectively. The latter allows real-time monitoring of the effect of added substances. As the cytotoxic compounds could compromise cell membrane integrity, the lactate dehydrogenase test was performed as well. We observed high toxic effects of bromoxynil, chloroxynil, and ioxynil on both tested cell lines. In contrast, we determined only low inhibition of cell growth in presence of dichlobenil and microbial metabolites originating from the tested herbicides. PMID:26339609

  8. Cytotoxic isoferulic acidamide from Myricaria germanica (Tamaricaceae).

    PubMed

    Nawwar, Mahmoud A; Swilam, Noha F; Hashim, Amani N; Al-Abd, Ahmed M; Abdel-Naim, Ashraf B; Lindequist, Ulrike

    2013-01-01

    Tamgermanitin, a unique N-trans-Isoferuloyltyramine, together with the hitherto unknown polyphenolics, 2,4-di-O-galloyl-(α/β)-glucopyranose and kaempferide 3,7-disulphate have been isolated from the leaf aqueous ethanol extract of the false tamarisk, Myricaria germanica DESV. In addition, 18 known phenolics were also separated and characterized. All structures were elucidated on the basis of detailed analysis of 1D- (1)H and (13)C NMR, COSY, HSQC, HMBC and HRFTESIMS spectral data. The extract, its chromatographic column fractions and the isolated isoferuloyltyramine, tamgermanetin demonstrated potential cytotoxic effect against three different tumor cell lines, namely liver (Huh-7), breast (MCF-7) and prostate (PC-3). The IC 50''s were found to be substantially low with low-resistance possibility. DNA flow-cytometic analysis indicated that column fractions and tamgermanetin enhanced pre-G apoptotic fraction. Both materials showed inhibiting activity against PARP enzyme activity. In conclusion, we report the isolation and identification of a novel compound, tamgermanitin, from the aqueous ethanol extract of Myricaria germanica leaves. Further, different fractions of the extract and tamgermanitin exhibit potent cytotoxic activities which warrant further investigations. PMID:23123452

  9. Study of Cytotoxic Effects of Benzonitrile Pesticides.

    PubMed

    Lovecka, Petra; Thimova, Marketa; Grznarova, Petra; Lipov, Jan; Knejzlik, Zdenek; Stiborova, Hana; Nindhia, Tjokorda Gde Tirta; Demnerova, Katerina; Ruml, Tomas

    2015-01-01

    The benzonitrile herbicides bromoxynil, chloroxynil, dichlobenil, and ioxynil have been used actively worldwide to control weeds in agriculture since 1970s. Even though dichlobenil is prohibited in EU since 2008, studies addressing the fate of benzonitrile herbicides in the environment show that some metabolites of these herbicides are very persistent. We tested the cytotoxic effects of benzonitrile herbicides and their microbial metabolites using two human cell lines, Hep G2 and HEK293T, representing liver and kidneys as potential target organs in humans. The cell viability and proliferation were determined by MTT test and RTCA DP Analyzer system, respectively. The latter allows real-time monitoring of the effect of added substances. As the cytotoxic compounds could compromise cell membrane integrity, the lactate dehydrogenase test was performed as well. We observed high toxic effects of bromoxynil, chloroxynil, and ioxynil on both tested cell lines. In contrast, we determined only low inhibition of cell growth in presence of dichlobenil and microbial metabolites originating from the tested herbicides. PMID:26339609

  10. Cytotoxicity of occupationally and environmentally relevant mycotoxins.

    PubMed

    Bünger, Jürgen; Westphal, Götz; Mönnich, Angelika; Hinnendahl, Britta; Hallier, Ernst; Müller, Michael

    2004-10-01

    Mycotoxins can cause various toxic effects in humans. Acute and chronic respiratory diseases were reported after inhalation of organic dust containing toxigenic moulds and mycotoxins, respectively. To gain first insights into health effects from airborne exposure to these compounds, five toxigenic airborne moulds of the genera Aspergillus and Penicillium collected at composting plants and eight reference mycotoxins were tested for cytotoxicity in four established cell lines as a surrogate of tissues known or suspected to be targets of toxic effects of mycotoxins. The known mycotoxins sterigmatocystin, fumagillin, verruculogen, penitrem A, and roquefortine C were detected in extracts of the moulds. All five extracts caused serious toxic effects in the cell lines. Sterigmatocystin caused a 80-fold higher toxicity in the A-549 lung cell line compared to Hep-G2 liver cells indicating a specific susceptibility of A-549 to this agent. Since only a minor part of the toxic effects of the extracts in A-549 cells and--to a lesser extent--in the other cell lines could be explained by contents of the identified mycotoxins, the presence of additional mycotoxins or other toxic principles is assumed in the mould extracts. However, the detected mycotoxins in the mould extracts and their distinctive cytotoxicity support the hypothesis that mycotoxins may be involved in the aetiology of lung diseases due to the inhalation of organic dust. PMID:15337583

  11. Cytotoxicity and genotoxicity of biogenic silver nanoparticles

    NASA Astrophysics Data System (ADS)

    Lima, R.; Feitosa, L. O.; Ballottin, D.; Marcato, P. D.; Tasic, L.; Durán, N.

    2013-04-01

    Biogenic silver nanoparticles with 40.3 ± 3.5 nm size and negative surface charge (- 40 mV) were prepared with Fusarium oxysporum. The cytotoxicity of 3T3 cell and human lymphocyte were studied by a TaliTM image-based cytometer and the genotoxicity through Allium cepa and comet assay. The results of BioAg-w (washed) and BioAg-nw (unwashed) biogenic silver nanoparticles showed cytotoxicity exceeding 50 μg/mL with no significant differences of response in 5 and 10 μg/mL regarding viability. Results of genotoxicity at concentrations 5.0 and 10.0 ug/mL show some response, but at concentrations 0.5 and 1.0 μg/mL the washed and unwashed silver nanoparticles did not present any effect. This in an important result since in tests with different bacteria species and strains, including resistant, MIC (minimal inhibitory concentration) had good answers at concentrations less than 1.9 μg/mL. This work concludes that biogenic silver nanoparticles may be a promising option for antimicrobial use in the range where no cyto or genotoxic effect were observed. Furthermore, human cells were found to have a greater resistance to the toxic effects of silver nanoparticles in comparison with other cells.

  12. Cytotoxicity of silver dressings on diabetic fibroblasts.

    PubMed

    Zou, Shi-Bo; Yoon, Won-Young; Han, Seung-Kyu; Jeong, Seong-Ho; Cui, Zheng-Jun; Kim, Woo-Kyung

    2013-06-01

    A large number of silver-based dressings are commonly used in the management of chronic wounds that are at risk of infection, including diabetic foot ulcers. However, there are still controversies regarding the toxicity of silver dressings on wound healing. The purpose of this study was to objectively test the cytotoxicity of silver dressings on human diabetic fibroblasts. Human diabetic fibroblasts were obtained from the foot skin of four diabetic foot ulcer patients and cultured. The effect of five silver-containing dressing products (Aquacel Ag, Acticoat*Absorbent, Medifoam Ag, Biatain Ag and PolyMem Ag) and their comparable silver-free dressing products on morphology, proliferation and collagen synthesis of the cultured human diabetic fibroblasts were compared in vitro. In addition, extracts of each dressing were tested in order to examine the effect of other chemical components found in the dressings on cytotoxicity. The diabetic fibroblasts cultured with each silver-free dressing adopted the typical dendritic and fusiform shape. On the other hand, the diabetic fibroblasts did not adopt this typical morphology when treated with the different silver dressings. All silver dressings tested in the study reduced the viability of the diabetic fibroblasts and collagen synthesis by 54-70 and 48-68%, respectively, when compared to silver-free dressings. Silver dressings significantly changed the cell morphology and decreased cell proliferation and collagen synthesis of diabetic fibroblasts. Therefore, silver dressings should be used with caution when treating diabetic wounds. PMID:22533495

  13. Cytotoxic benzophenone and triterpene from Garcinia hombroniana.

    PubMed

    Jamila, Nargis; Khairuddean, Melati; Yaacob, Nik Soriani; Kamal, Nik Nur Syazni Nik Mohamed; Osman, Hasnah; Khan, Sadiq Noor; Khan, Naeem

    2014-06-01

    Garcinia hombroniana (seashore mangosteen) in Malaysia is used to treat itching and as a protective medicine after child birth. This study was aimed to investigate the bioactive chemical constituents of the bark of G. hombroniana. Ethyl acetate and dichloromethane extracts of G. hombroniana yielded two new (1, 9) and thirteen known compounds which were characterized by the spectral techniques of NMR, UV, IR and EI/ESI-MS, and identified as; 2,3',4,5'-tetrahydroxy-6-methoxybenzophenone(1), 2,3',4,4'-tetrahydroxy-6-methoxybenzophenone (2), 2,3',4,6-tetrahydroxybenzophenone (3), 1,3,6,7-tetrahydroxyxanthone (4), 3,3',4',5,7-pentahydroxyflavone (5),3,3',5,5',7-pentahydroxyflavanone (6), 3,3',4',5,5',7-hexahydroxyflavone (7), 4',5,7-trihydroxyflavanone-7-rutinoside (8), 18(13→17)-abeo-3β-acetoxy-9α,13β-lanost-24E-en-26-oic acid (9), garcihombronane B (10), garcihombronane D (11), friedelan-3-one (12), lupeol (13), stigmasterol (14) and stigmasterol glucoside (15). In the in vitro cytotoxicity against MCF-7, DBTRG, U2OS and PC-3 cell lines, compounds 1 and 9 displayed good cytotoxic effects against DBTRG cancer cell lines. Compounds 1-8 were also found to possess significant antioxidant activities. Owing to these properties, this study can be further extended to explore more significant bioactive components of this plant. PMID:24813683

  14. Thirdhand tobacco smoke: procedures to evaluate cytotoxicity in cell cultures.

    PubMed

    Figueiró, Luciana Rizzieri; Dantas, Denise Conceição Mesquita; Linden, Rafael; Ziulkoski, Ana Luiza

    2016-06-01

    The risks associated to tobacco smoking are not ceased with smoke extinction. Many toxic compounds remain in the environment after the cigarette is extinguished and accumulated in the air or on surfaces. However, little is known about the risks of this exposure. The aim of this study was to evaluate procedures to collect thirdhand smoke (THS) and prepare the samples to perform three in vitro toxicity tests. Cellulose papers and cotton wipes were used to impregnate with nicotine solution and smoke cigarette in a chamber or in smoker's home. Samples were immersed in methanol or Dulbecco's modified Eagle's medium (DMEM) to expose Hep-2 cells. MTT, neutral red uptake (NRU) and trypan blue assays were performed. The concentration of nicotine in DMEM extract of THS in paper and cotton was similar to those in methanol extract (p > 0.05). Alterations in the mitochondrial and lysosomal functions were found in both paper and cotton samples; however, the cytotoxic effect was not always observed. There was a decrease of 21-31% in MTT assay and 38-56% in NRU assay (p < 0.003). There was a dose-response relationship between the amount of cigarettes and lysosomal viability; the correlation was higher for cotton samples (r = -0.843, p < 0.001). As a dose-response relationship was found only in NRU assay, this test may be a more suitable choice rather than the MTT assay. Paper and wipe sampling can be reliable markers of tobacco smoke contamination. Moreover, these materials, if properly prepared, can be used as substrate providers to perform cellular assays. PMID:27268319

  15. Uncovering the polymerase-induced cytotoxicity of an oxidized nucleotide

    NASA Astrophysics Data System (ADS)

    Freudenthal, Bret D.; Beard, William A.; Perera, Lalith; Shock, David D.; Kim, Taejin; Schlick, Tamar; Wilson, Samuel H.

    2015-01-01

    Oxidative stress promotes genomic instability and human diseases. A common oxidized nucleoside is 8-oxo-7,8-dihydro-2'-deoxyguanosine, which is found both in DNA (8-oxo-G) and as a free nucleotide (8-oxo-dGTP). Nucleotide pools are especially vulnerable to oxidative damage. Therefore cells encode an enzyme (MutT/MTH1) that removes free oxidized nucleotides. This cleansing function is required for cancer cell survival and to modulate Escherichia coli antibiotic sensitivity in a DNA polymerase (pol)-dependent manner. How polymerases discriminate between damaged and non-damaged nucleotides is not well understood. This analysis is essential given the role of oxidized nucleotides in mutagenesis, cancer therapeutics, and bacterial antibiotics. Even with cellular sanitizing activities, nucleotide pools contain enough 8-oxo-dGTP to promote mutagenesis. This arises from the dual coding potential where 8-oxo-dGTP(anti) base pairs with cytosine and 8-oxo-dGTP(syn) uses its Hoogsteen edge to base pair with adenine. Here we use time-lapse crystallography to follow 8-oxo-dGTP insertion opposite adenine or cytosine with human pol β, to reveal that insertion is accommodated in either the syn- or anti-conformation, respectively. For 8-oxo-dGTP(anti) insertion, a novel divalent metal relieves repulsive interactions between the adducted guanine base and the triphosphate of the oxidized nucleotide. With either templating base, hydrogen-bonding interactions between the bases are lost as the enzyme reopens after catalysis, leading to a cytotoxic nicked DNA repair intermediate. Combining structural snapshots with kinetic and computational analysis reveals how 8-oxo-dGTP uses charge modulation during insertion that can lead to a blocked DNA repair intermediate.

  16. Cytotoxicity of surface-functionalized silicon and germanium nanoparticles: the dominant role of surface charges

    NASA Astrophysics Data System (ADS)

    Bhattacharjee, Sourav; Rietjens, Ivonne M. C. M.; Singh, Mani P.; Atkins, Tonya M.; Purkait, Tapas K.; Xu, Zejing; Regli, Sarah; Shukaliak, Amber; Clark, Rhett J.; Mitchell, Brian S.; Alink, Gerrit M.; Marcelis, Antonius T. M.; Fink, Mark J.; Veinot, Jonathan G. C.; Kauzlarich, Susan M.; Zuilhof, Han

    2013-05-01

    Although it is frequently hypothesized that surface (like surface charge) and physical characteristics (like particle size) play important roles in cellular interactions of nanoparticles (NPs), a systematic study probing this issue is missing. Hence, a comparative cytotoxicity study, quantifying nine different cellular endpoints, was performed with a broad series of monodisperse, well characterized silicon (Si) and germanium (Ge) NPs with various surface functionalizations. Human colonic adenocarcinoma Caco-2 and rat alveolar macrophage NR8383 cells were used to clarify the toxicity of this series of NPs. The surface coatings on the NPs appeared to dominate the cytotoxicity: the cationic NPs exhibited cytotoxicity, whereas the carboxylic acid-terminated and hydrophilic PEG- or dextran-terminated NPs did not. Within the cationic Si NPs, smaller Si NPs were more toxic than bigger ones. Manganese-doped (1% Mn) Si NPs did not show any added toxicity, which favors their further development for bioimaging. Iron-doped (1% Fe) Si NPs showed some added toxicity, which may be due to the leaching of Fe3+ ions from the core. A silica coating seemed to impart toxicity, in line with the reported toxicity of silica. Intracellular mitochondria seem to be the target for the toxic NPs since a dose-, surface charge- and size-dependent imbalance of the mitochondrial membrane potential was observed. Such an imbalance led to a series of other cellular events for cationic NPs, like decreased mitochondrial membrane potential (ΔΨm) and ATP production, induction of ROS generation, increased cytoplasmic Ca2+ content, production of TNF-α and enhanced caspase-3 activity. Taken together, the results explain the toxicity of Si NPs/Ge NPs largely by their surface characteristics, provide insight into the mode of action underlying the observed cytotoxicity, and give directions on synthesizing biocompatible Si and Ge NPs, as this is crucial for bioimaging and other applications in for example

  17. Herpesvirus ateles and herpesvirus saimiri transform marmoset T cells into continuously proliferating cell lines that can mediate natural killer cell-like cytotoxicity.

    PubMed Central

    Johnson, D R; Jondal, M

    1981-01-01

    Herpesvirus ateles (HVA) and herpesvirus saimiri (HVS) have the capacity to transform cotton-topped marmoset T lymphocytes into continuously proliferating cell lines that retain some functions associated with cell-mediated immunity. In the present paper, we demonstrate that HVA/HVS-transformed T cell lines are cytotoxic in a short-term 51Cr release assay and that this killing resembles killing by marmoset natural killer (NK) cells. The relationship between NK cells and HVA/HVS-transformed killer cell lines is discussed in view of present knowledge of the origin and function of the NK system. It is suggested that the described cytotoxic cell lines may be useful for further defining cellular cytotoxicity with regard to cell surface recognition, regulatory events, and lytic mechanisms. PMID:6273869

  18. Mechanism of cellular uptake of genotoxic silica nanoparticles

    PubMed Central

    2012-01-01

    Mechanisms for cellular uptake of nanoparticles have important implications for nanoparticulate drug delivery and toxicity. We have explored the mechanism of uptake of amorphous silica nanoparticles of 14 nm diameter, which agglomerate in culture medium to hydrodynamic diameters around 500 nm. In HT29, HaCat and A549 cells, cytotoxicity was observed at nanoparticle concentrations ≥ 1 μg/ml, but DNA damage was evident at 0.1 μg/ml and above. Transmission electron microscopy (TEM) combined with energy-dispersive X-ray spectroscopy confirmed entry of the silica particles into A549 cells exposed to 10 μg/ml of nanoparticles. The particles were observed in the cytoplasm but not within membrane bound vesicles or in the nucleus. TEM of cells exposed to nanoparticles at 4°C for 30 minutes showed particles enter cells when activity is low, suggesting a passive mode of entry. Plasma lipid membrane models identified physical interactions between the membrane and the silica NPs. Quartz crystal microbalance experiments on tethered bilayer lipid membrane systems show that the nanoparticles strongly bind to lipid membranes, forming an adherent monolayer on the membrane. Leakage assays on large unilamellar vesicles (400 nm diameter) indicate that binding of the silica NPs transiently disrupts the vesicles which rapidly self-seal. We suggest that an adhesive interaction between silica nanoparticles and lipid membranes could cause passive cellular uptake of the particles. PMID:22823932

  19. Membrane organization and regulation of cellular Cholesterol homeostasis

    PubMed Central

    Jaureguiberry, María S.; Tricerri, M. Alejandra; Sanchez, Susana A; Garda, Horacio A; Finarelli, Gabriela S.; Gonzalez, Marina C.; Rimoldi, Omar J.

    2010-01-01

    An excess of intracellular free Cholesterol (Chol) is cytotoxic, and its homeostasis is crucial for cell viability. Apolipoprotein A–I (apoA-I) is a highly efficient Chol acceptor as it activates complex cellular pathways that tend to mobilize and export Chol from cellular depots. Here we hypothesize that membrane composition and/or organization is strongly involved in Chol homeostasis. To test this hypothesis, we constructed a cell line over expressing Stearoyl CoA desaturase (SCD-cells), which modifies plasma membrane (PM) composition by the enrichment of monounsaturated fatty,acids and determined this effect on membrane properties, cell viability and cholesterol homeostasis. PM in SCD-cells has a higher phospholipids/sphingomyelin ratio and is slightly enriched in Chol. These cells showed an increase in the cholesteryl esters/free Chol ratio, they were more resistant to Chol toxicity and in addition, they exported more caveolin than Control cells. The data suggest that cell functionality is preserved by regulating membrane fluidity and Chol exportation and storage. PMID:20336284

  20. Plasmodium cellular effector mechanisms and the hepatic microenvironment

    PubMed Central

    Frevert, Ute; Krzych, Urszula

    2015-01-01

    Plasmodium falciparum malaria remains one of the most serious health problems globally. Immunization with attenuated parasites elicits multiple cellular effector mechanisms capable of eliminating Plasmodium liver stages. However, malaria liver stage (LS) immunity is complex and the mechanisms effector T cells use to locate the few infected hepatocytes in the large liver in order to kill the intracellular LS parasites remain a mystery to date. Here, we review our current knowledge on the behavior of CD8 effector T cells in the hepatic microvasculature, in malaria and other hepatic infections. Taking into account the unique immunological and lymphogenic properties of the liver, we discuss whether classical granule-mediated cytotoxicity might eliminate infected hepatocytes via direct cell contact or whether cytokines might operate without cell–cell contact and kill Plasmodium LSs at a distance. A thorough understanding of the cellular effector mechanisms that lead to parasite death hence sterile protection is a prerequisite for the development of a successful malaria vaccine to protect the 40% of the world’s population currently at risk of Plasmodium infection. PMID:26074888

  1. Humoral and Cellular Immune Response in Canine Hypothyroidism.

    PubMed

    Miller, J; Popiel, J; Chełmońska-Soyta, A

    2015-07-01

    Hypothyroidism is one of the most common endocrine diseases in dogs and is generally considered to be autoimmune in nature. In human hypothyroidism, the thyroid gland is destroyed by both cellular (i.e. autoreactive helper and cytotoxic T lymphocytes) and humoral (i.e. autoantibodies specific for thyroglobulin, thyroxine and triiodothyronine) effector mechanisms. Other suggested factors include impaired peripheral immune suppression (i.e. the malfunction of regulatory T cells) or an additional pro-inflammatory effect of T helper 17 lymphocytes. The aim of this study was to evaluate immunological changes in canine hypothyroidism. Twenty-eight clinically healthy dogs, 25 hypothyroid dogs without thyroglobulin antibodies and eight hypothyroid dogs with these autoantibodies were enrolled into the study. There were alterations in serum proteins in hypothyroid dogs compared with healthy controls (i.e. raised concentrations of α-globulins, β2- and γ-globulins) as well as higher concentration of acute phase proteins and circulating immune complexes. Hypothyroid animals had a lower CD4:CD8 ratio in peripheral blood compared with control dogs and diseased dogs also had higher expression of interferon γ (gene and protein expression) and CD28 (gene expression). Similar findings were found in both groups of hypothyroid dogs. Canine hypothyroidism is therefore characterized by systemic inflammation with dominance of a cellular immune response. PMID:25958183

  2. Preparation and Photoacoustic Analysis of Cellular Vehicles Containing Gold Nanorods.

    PubMed

    Cavigli, Lucia; Tatini, Francesca; Borri, Claudia; Ratto, Fulvio; Centi, Sonia; Cini, Alberto; Lelli, Beatrice; Matteini, Paolo; Pini, Roberto

    2016-01-01

    Gold nanorods are attractive for a range of biomedical applications, such as the photothermal ablation and the photoacoustic imaging of cancer, thanks to their intense optical absorbance in the near-infrared window, low cytotoxicity and potential to home into tumors. However, their delivery to tumors still remains an issue. An innovative approach consists of the exploitation of the tropism of tumor-associated macrophages that may be loaded with gold nanorods in vitro. Here, we describe the preparation and the photoacoustic inspection of cellular vehicles containing gold nanorods. PEGylated gold nanorods are modified with quaternary ammonium compounds, in order to achieve a cationic profile. On contact with murine macrophages in ordinary Petri dishes, these particles are found to undergo massive uptake into endocytic vesicles. Then these cells are embedded in biopolymeric hydrogels, which are used to verify that the stability of photoacoustic conversion of the particles is retained in their inclusion into cellular vehicles. We are confident that these results may provide new inspiration for the development of novel strategies to deliver plasmonic particles to tumors. PMID:27167995

  3. Thermodynamics of cellular statistical inference

    NASA Astrophysics Data System (ADS)

    Lang, Alex; Fisher, Charles; Mehta, Pankaj

    2014-03-01

    Successful organisms must be capable of accurately sensing the surrounding environment in order to locate nutrients and evade toxins or predators. However, single cell organisms face a multitude of limitations on their accuracy of sensing. Berg and Purcell first examined the canonical example of statistical limitations to cellular learning of a diffusing chemical and established a fundamental limit to statistical accuracy. Recent work has shown that the Berg and Purcell learning limit can be exceeded using Maximum Likelihood Estimation. Here, we recast the cellular sensing problem as a statistical inference problem and discuss the relationship between the efficiency of an estimator and its thermodynamic properties. We explicitly model a single non-equilibrium receptor and examine the constraints on statistical inference imposed by noisy biochemical networks. Our work shows that cells must balance sample number, specificity, and energy consumption when performing statistical inference. These tradeoffs place significant constraints on the practical implementation of statistical estimators in a cell.

  4. Optofluidic Detection for Cellular Phenotyping

    PubMed Central

    Tung, Yi-Chung; Huang, Nien-Tsu; Oh, Bo-Ram; Patra, Bishnubrata; Pan, Chi-Chun; Qiu, Teng; Paul, K. Chu; Zhang, Wenjun; Kurabayashi, Katsuo

    2012-01-01

    Quantitative analysis of the output of processes and molecular interactions within a single cell is highly critical to the advancement of accurate disease screening and personalized medicine. Optical detection is one of the most broadly adapted measurement methods in biological and clinical assays and serves cellular phenotyping. Recently, microfluidics has obtained increasing attention due to several advantages, such as small sample and reagent volumes, very high throughput, and accurate flow control in the spatial and temporal domains. Optofluidics, which is the attempt to integrate optics with microfluidic, shows great promise to enable on-chip phenotypic measurements with high precision, sensitivity, specificity, and simplicity. This paper reviews the most recent developments of optofluidic technologies for cellular phenotyping optical detection. PMID:22854915

  5. Hox Targets and Cellular Functions

    PubMed Central

    Sánchez-Herrero, Ernesto

    2013-01-01

    Hox genes are a group of genes that specify structures along the anteroposterior axis in bilaterians. Although in many cases they do so by modifying a homologous structure with a different (or no) Hox input, there are also examples of Hox genes constructing new organs with no homology in other regions of the body. Hox genes determine structures though the regulation of targets implementing cellular functions and by coordinating cell behavior. The genetic organization to construct or modify a certain organ involves both a genetic cascade through intermediate transcription factors and a direct regulation of targets carrying out cellular functions. In this review I discuss new data from genome-wide techniques, as well as previous genetic and developmental information, to describe some examples of Hox regulation of different cell functions. I also discuss the organization of genetic cascades leading to the development of new organs, mainly using Drosophila melanogaster as the model to analyze Hox function. PMID:24490109

  6. Peroxisome Metabolism and Cellular Aging

    PubMed Central

    Titorenko, Vladimir I.; Terlecky, Stanley R.

    2010-01-01

    The essential role of peroxisomes in fatty acid oxidation, anaplerotic metabolism, and hydrogen peroxide turnover is well established. Recent findings suggest these and other related biochemical processes governed by the organelle may also play a critical role in regulating cellular aging. The goal of this review is to summarize and integrate into a model, the evidence that peroxisome metabolism actually helps define the replicative and chronological age of a eukaryotic cell. In this model, peroxisomal reactive oxygen species (ROS) are seen as altering organelle biogenesis and function, and eliciting changes in the dynamic communication networks that exist between peroxisomes and other cellular compartments. At low levels, peroxisomal ROS activate an anti-aging program in the cell; at concentrations beyond a specific threshold, a pro-aging course is triggered. PMID:21083858

  7. Cellular solidification of transparent monotectics

    NASA Technical Reports Server (NTRS)

    Kaulker, W. F.

    1986-01-01

    Understanding how liquid phase particles are engulfed or pushed during freezing of a monotectic is addressed. The additional complication is that the solid-liquid interface is nonplanar due to constitutional undercooling. Some evidence of particle pushing where the particles are the liquid phase of the montectic was already observed. Cellular freezing of the succinonitrile-glycerol system also occurred. Only a few compositions were tested at that time. The starting materials were not especially pure so that cellular interface observed was likely due to the presence of unkown impurities, the major portion of which was water. Topics addressed include: the effort of modeling the particle pushing process using the computer, establishing an apparatus for the determination of phase diagrams, and the measurement of the temperature gradients with a specimen which will solidify on the temperature gradient microscope stage.

  8. Activating Transcription Factor 3 regulates in part the enhanced tumour cell cytotoxicity of the histone deacetylase inhibitor M344 and cisplatin in combination

    PubMed Central

    2010-01-01

    Background Activating Transcription Factor (ATF) 3 is a key regulator of the cellular integrated stress response whose expression has also been correlated with pro-apoptotic activities in tumour cell models. Combination treatments with chemotherapeutic drugs, such as cisplatin, and histone deacetylase (HDAC) inhibitors have been demonstrated to enhance tumour cell cytotoxicity. We recently demonstrated a role for ATF3 in regulating cisplatin-induced apoptosis and others have shown that HDAC inhibition can also induce cellular stress. In this study, we evaluated the role of ATF3 in regulating the co-operative cytotoxicity of cisplatin in combination with an HDAC inhibitor. Results The HDAC inhibitor M344 induced ATF3 expression at the protein and mRNA level in a panel of human derived cancer cell lines as determined by Western blot and quantitative RT-PCR analyses. Combination treatment with M344 and cisplatin lead to increased induction of ATF3 compared with cisplatin alone. Utilizing the MTT cell viability assay, M344 treatments also enhanced the cytotoxic effects of cisplatin in these cancer cell lines. The mechanism of ATF3 induction by M344 was found to be independent of MAPKinase pathways and dependent on ATF4, a known regulator of ATF3 expression. ATF4 heterozygote (+/-) and knock out (-/-) mouse embryonic fibroblast (MEF) as well as chromatin immunoprecipitation (ChIP) assays were utilized in determining the mechanistic induction of ATF3 by M344. We also demonstrated that ATF3 regulates the enhanced cytotoxicity of M344 in combination with cisplatin as evidenced by attenuation of cytotoxicity in shRNAs targeting ATF3 expressing cells. Conclusion This study identifies the pro-apoptotic factor, ATF3 as a novel target of M344, as well as a mediator of the co-operative effects of cisplatin and M344 induced tumour cell cytotoxicity. PMID:20828393

  9. Xtoys: Cellular automata on xwindows

    SciTech Connect

    Creutz, M.

    1995-08-15

    Xtoys is a collection of xwindow programs for demonstrating simulations of various statistical models. Included are xising, for the two dimensional Ising model, xpotts, for the q-state Potts model, xautomalab, for a fairly general class of totalistic cellular automata, xsand, for the Bak-Tang-Wiesenfield model of self organized criticality, and xfires, a simple forest fire simulation. The programs should compile on any machine supporting xwindows.

  10. In vitro macrophage cytotoxicity of five calcium silicates.

    PubMed Central

    Skaug, V; Davies, R; Gylseth, B

    1984-01-01

    Five calcium silicate minerals (two naturally occurring and three synthetic compounds) with defined morphology and chemical composition were compared for their cytotoxic and lysosomal enzyme releasing effects on unstimulated mouse peritoneal macrophages in vitro. One synthetic material, a fibrous tobermorite, was cytotoxic towards the cells, and two naturally occurring wollastonites induced selective release of beta-glucuronidase from the cells. Images PMID:6318798

  11. [Study of cytotoxic and antiviral effects of some eye drops].

    PubMed

    Dediulescu, Lucreţia; Dediulescu, Daniela Florentina

    2008-01-01

    The study of the cytotoxic and antiviral effect of six commercial mixtures, eye drops type, underlined the advantages of using eye drops with Indomethacin for Herpetic Keratitis, due to the antiviral effect and also for the lack of cytotoxicity. PMID:19354165

  12. New cytotoxic steroids from the soft coral Clavularia viridis.

    PubMed

    Duh, Chang-Yih; Lo, I-Wen; Wang, Shang-Kwei; Dai, Chang-Feng

    2007-06-01

    Ten new cytotoxic steroids, stoloniferones H-Q (1-10) were isolated from the methylene chloride solubles of the soft coral Clavularia viridis. The structures of the metabolites were elucidated on the basis of spectroscopic (IR, MS, and 1D and 2D NMR) analysis and their cytotoxicity against selected cancer cells was measured in vitro. PMID:17485104

  13. Competitive potential of cellular mobile telecommunications

    SciTech Connect

    Ware, H.

    1983-02-03

    The Federal Communications Commission (FCC) has recently issued rules for the commercial operation of a telecommunications technology not previously in commercial use: the cellular mobile radio. The author has carefully considered the potential for competition between cellular systems and for competition between cellular radio and alternative communications technologies under the regulatory scheme which has been adopted by the FCC. He finds that competition between cellular and wire-line services can be viable if cellular cost and demand data are carefully tracked to avoid market congestion and if cellular or other techniques are not allowed to undercut selected local exchange rates.

  14. Cyclosporine A and palmitic acid treatment synergistically induce cytotoxicity in HepG2 cells

    SciTech Connect

    Luo, Yi Rana, Payal; Will, Yvonne

    2012-06-01

    Immunosuppressant cyclosporine A (CsA) treatment can cause severe side effects. Patients taking immunosuppressant after organ transplantation often display hyperlipidemia and obesity. Elevated levels of free fatty acids have been linked to the etiology of metabolic syndromes, nonalcoholic fatty liver and steatohepatitis. The contribution of free fatty acids to CsA-induced toxicity is not known. In this study we explored the effect of palmitic acid on CsA-induced toxicity in HepG2 cells. CsA by itself at therapeutic exposure levels did not induce detectible cytotoxicity in HepG2 cells. Co-treatment of palmitic acid and CsA resulted in a dose dependent increase in cytotoxicity, suggesting that fatty acid could sensitize cells to CsA-induced cytotoxicity at the therapeutic doses of CsA. A synergized induction of caspase-3/7 activity was also observed, indicating that apoptosis may contribute to the cytotoxicity. We demonstrated that CsA reduced cellular oxygen consumption which was further exacerbated by palmitic acid, implicating that impaired mitochondrial respiration might be an underlying mechanism for the enhanced toxicity. Inhibition of c-Jun N-terminal kinase (JNK) attenuated palmitic acid and CsA induced toxicity, suggesting that JNK activation plays an important role in mediating the enhanced palmitic acid/CsA-induced toxicity. Our data suggest that elevated FFA levels, especially saturated FFA such as palmitic acid, may be predisposing factors for CsA toxicity, and patients with underlying diseases that would elevate free fatty acids may be susceptible to CsA-induced toxicity. Furthermore, hyperlipidemia/obesity resulting from immunosuppressive therapy may aggravate CsA-induced toxicity and worsen the outcome in transplant patients. -- Highlights: ► Palmitic acid and cyclosporine (CsA) synergistically increased cytotoxicity. ► The impairment of mitochondrial functions may contribute to the enhanced toxicity. ► Inhibition of JNK activity attenuated

  15. Internalization and cytotoxicity effects of carbon-encapsulated iron nanoparticles in murine endothelial cells: Studies on internal dosages due to loaded mass agglomerates.

    PubMed

    Cywinska, Monika A; Bystrzejewski, Michal; Poplawska, Magdalena; Kosmider, Anita; Zdanowski, Robert; Lewicki, Slawomir; Fijalek, Zbigniew; Ostrowska, Agnieszka; Bamburowicz, Magdalena; Cieszanowski, Andrzej; Grudzinski, Ireneusz P

    2016-08-01

    Carbon-encapsulated iron nanoparticles (CEINs) qualified as metal-inorganic hybrid nanomaterials offer a potential scope for an increasing number of biomedical applications. In this study, we have focused on the investigation of cellular fate and resulting cytotoxic effects of CEINs synthesized using a carbon arc route and studied in murine endothelial (HECa-10) cells. The CEIN samples were characterized as pristine (the mean diameter between 47 and 56nm) and hydrodynamic (the mean diameter between 270 and 460nm) forms and tested using a battery of methods to determine the cell internalization extent and cytotoxicity effects upon to the exposures (0.0001-100μg/ml) in HECa-10 cells. Our studies evidenced that the incubation with CEINs for 24h is accompanied with substantial changes of Zeta potential in cells which can be considered as a key factor for affecting the membrane transport, cellular distribution and cytotoxicity of these nanoparticles. The results demonstrate that CEINs have entered the endothelial cell through the endocytic pathway rather than by passive diffusion and they were mainly loaded as agglomerates on the cell membrane and throughout the cytoplasm, mitochondria and nucleus. The studies show that CEINs induce the mitochondrial and cell membrane cytotoxicities in a dose-dependent manner resulting from the internal dosages due to CEIN agglomerates. Our results highlight the importance of the physicochemical characterization of CEINs in studying the magnetic nanoparticle-endothelial cell interactions because the CEIN mass agglomerates can sediment more or less rapidly in culture models. PMID:27107485

  16. Size dependent cytotoxicity of fly ash particles

    SciTech Connect

    Liu, W.K.; Tam, J.S.K.; Wong, M.H.

    1988-01-01

    Fly ash samples were collected from the electrostatic precipitator of a coal-fired power plant in Hong Kong. The particles of the respirable range (smaller than 10 {mu}m) were divided into 4 groups according to their particle size (mass median aerodynamic diameters). The surface morphology and the metal contents (Fe, Mn, Al and Zn) of fly ash particles were examined by a scanning electron microscopy and an inductively coupled plasma spectrophotometer, respectively. The particles were very heterogeneous in size and shape as well as the concentration of metals. The cytotoxicity of these four groups of fly ash particles were evaluated using an in vitro rat alveolar macrophages culture assay. The viability of alveolar macrophages was lower when incubated with smaller size particles. This relationship was also reflected by the damage of the surface morphology of the cells and the release of cytoplasmic (lactate dehydrogenase) and lysosomal (acid phosphatase and {beta}-glucuronidase) marker enzymes into the culture media.

  17. Synthesis and cytotoxic properties of tryptamine derivatives.

    PubMed

    Salikov, Rinat F; Belyy, Aleksandr Yu; Khusnutdinova, Nailya S; Vakhitova, Yulia V; Tomilov, Yury V

    2015-09-01

    The cyclopropyliminium and subsequent Grandberg rearrangements of cyclopropylketone hydrozones lead to the formation of tryptamines, which were additionally substituted at either the aromatic ring atoms or the amino group. The products were tested for their cytotoxic properties against HepG2, Jurkat and HEK293 cell lines using MTT assay. The highest activity as well as the highest selectivity was found amongst the compounds derived with one benzyl substituent at the amino group. The flow cytometry technique revealed cell-type specificity in terms of the mechanism of viability inhibition. Thus, the compounds were found to induce mainly apoptosis in HEK293 and HepG2 cells, while Jurkat cells displayed late apoptotic and necrotic responses. The apoptosis pathway is most likely to include mitochondrial damage. PMID:26174553

  18. Stability and cytotoxicity of crystallin amyloid nanofibrils.

    PubMed

    Kaur, Manmeet; Healy, Jackie; Vasudevamurthy, Madhusudan; Lassé, Moritz; Puskar, Ljiljana; Tobin, Mark J; Valery, Celine; Gerrard, Juliet A; Sasso, Luigi

    2014-11-01

    Previous work has identified crystallin proteins extracted from fish eye lenses as a cheap and readily available source for the self-assembly of amyloid nanofibrils. However, before exploring potential applications, the biophysical aspects and safety of this bionanomaterial need to be assessed so as to ensure that it can be effectively and safely used. In this study, crude crystallin amyloid fibrils are shown to be stable across a wide pH range, in a number of industrially relevant solvents, at both low and high temperatures, and in the presence of proteases. Crystallin nanofibrils were compared to well characterised insulin and whey protein fibrils using Thioflavin T assays and TEM imaging. Cell cytotoxicity assays suggest no adverse impact of both mature and fragmented crystallin fibrils on cell viability of Hec-1a endometrial cells. An IR microspectroscopy study supports long-term structural integrity of crystallin nanofibrils. PMID:25255060

  19. Fluid dynamics of cytotoxic safety cabinets.

    PubMed

    Braconnier, R; Bonthoux, F

    2010-03-01

    This study investigated the specific fluid dynamics characteristics of cytotoxic safety cabinets (CSC), particularly those used in cancer drug reconstitution operations. Measurements taken on site were used to derive characteristic data for these cabinets. An in-depth laboratory investigation of airflows inside another CSC was also conducted. Anemometric values recorded on these two installations enabled the experimental validation of computational fluid dynamics methods applied to CSC. The digital flow simulations conducted provide a better understanding of the detailed flow structure inside a CSC and made it possible to study the influence of different operating parameters on the air velocity distribution inside the cabinet front opening: recycled air temperature, product protection airflow rate, suction openings spatial distribution, air compensation mode and draughts, operator arm penetration, and operator presence in front of the cabinet. PMID:20007340

  20. Cell signaling and cytotoxicity by peroxynitrite.

    PubMed Central

    Cantoni, Orazio; Palomba, Letizia; Guidarelli, Andrea; Tommasini, Ilaria; Cerioni, Liana; Sestili, Piero

    2002-01-01

    Reactive nitrogen species are now considered to play an important role in various pathologies. Although the pathological significance of these molecules, peroxynitrite in particular, has long been attributed to their abilities to react with any component of the cells, including lipids, proteins, and DNA, a paradigm shift has recently been occurring whereby reactive nitrogen species are appreciated as signaling molecules. The question therefore arises as to whether nitrosative stress is indeed the result of a random (stochastic) process of cell damage, as it has traditionally been viewed, or rather is a consequence of the specific activation of a cascade of signaling events. The above considerations have provided the bases for the research work performed in our laboratory, and the results obtained are illustrated in the present article. In particular, our results indicate that some effects of peroxynitrite are not directly mediated by the oxidant; rather, it appears that peroxynitrite triggers a signaling pathway that finally leads to cytotoxicity. PMID:12426139

  1. Cytotoxic indole alkaloids from Tabernaemontana divaricata.

    PubMed

    Bao, Mei-Fen; Yan, Ju-Ming; Cheng, Gui-Guang; Li, Xing-Yao; Liu, Ya-Ping; Li, Yan; Cai, Xiang-Hai; Luo, Xiao-Dong

    2013-08-23

    Five new vobasinyl-ibogan-type bisindole alkaloids, tabernaricatines A-E (1-5), two new monomers, tabernaricatines F and G (6 and 7), and 24 known indole alkaloids were isolated from the aerial parts of Tabernaemontana divaricata. Alkaloids 1 and 2 are the first vobasinyl-ibogan-type alkaloids possessing a six-membered ring via an ether linkage between C-17 and C-21. All compounds except for 3 were evaluated for their cytotoxicity against five human cancer cell lines; conophylline showed significant bioactivity against HL-60, SMMC-7721, A-549, MCF-7, and SW480 cells with IC₅₀ values of 0.17, 0.35, 0.21, 1.02, and 1.49 μM, respectively. PMID:23944995

  2. Cytotoxic withanolide constituents of Physalis longifolia.

    PubMed

    Zhang, Huaping; Samadi, Abbas K; Gallagher, Robert J; Araya, Juan J; Tong, Xiaoqin; Day, Victor W; Cohen, Mark S; Kindscher, Kelly; Gollapudi, Rao; Timmermann, Barbara N

    2011-12-27

    Fourteen new withanolides, 1-14, named withalongolides A-N, respectively, were isolated from the aerial parts of Physalis longifolia together with eight known compounds (15-22). The structures of compounds 1-14 were elucidated through spectroscopic techniques and chemical methods. In addition, the structures of withanolides 1, 2, 3, and 6 were confirmed by X-ray crystallographic analysis. Using a MTS viability assay, eight withanolides (1, 2, 3, 7, 8, 15, 16, and 19) and four acetylated derivatives (1a, 1b, 2a, and 2b) showed potent cytotoxicity against human head and neck squamous cell carcinoma (JMAR and MDA-1986), melanoma (B16F10 and SKMEL-28), and normal fetal fibroblast (MRC-5) cells with IC₅₀ values in the range between 0.067 and 9.3 μM. PMID:22098611

  3. Cytotoxic Withanolide Constituents of Physalis longifolia

    PubMed Central

    Zhang, Huaping; Samadi, Abbas K.; Gallagher, Robert J.; Araya, Juan J.; Tong, Xiaoqin; Day, Victor W.; Cohen, Mark S.; Kindscher, Kelly; Gollapudi, Rao; Timmermann, Barbara N.

    2011-01-01

    Fourteen new withanolides 1-14, named withalongolides A-N, respectively, were isolated from the aerial parts of Physalis longifolia together with eight known compounds (15-22). The structures of compounds 1-14 were elucidated through spectroscopic techniques and chemical methods. In addition, the structures of withanolides 1, 2, 3, and 6 were confirmed by X-ray crystallographic analysis. Using a MTS viability assays, eight withanolides (1, 2, 3, 7, 8, 15, 16, and 19) and four acetylated derivatives (1a, 1b, 2a, and 2b) showed potent cytotoxicity against human head and neck squamous cell carcinoma (JMAR and MDA-1986), melanoma (B16F10 and SKMEL-28), and normal fetal fibroblast (MRC-5) cells with IC50 values in the range between 0.067 and 9.3 μM. PMID:22098611

  4. Cytotoxic Activities of Flavonoids from Centaurea scoparia

    PubMed Central

    Ahmed, Sayed A.; Kamel, Emadeldin M.

    2014-01-01

    Phytochemical studies on the ethanolic extract of the aerial parts of Centaurea scoparia led to the isolation of two new flavonoids, 3′,4′-dihydroxy-(3′′,4′′-dihydro-3′′-hydroxy-4′′-acetoxy)-2′′,2′′-dimethylpyrano-(5′′,6′′:7,8)-flavone-3-O-β-D-glucopyranoside (1) and 3,3′,4′-trihydroxy-(3′′,4′′-dihydro-3′′,4′′-dihydroxy)-2′′,2′′-dimethylpyrano-(5′′,6′′:7,8)-flavone (2), along with eight known flavonoids isolated for the first time from this plant, cynaroside (3), Apigetrin (4), centaureidin (5), oroxylin A (6), 5,7-dihydroxy-3′,4′,5′-trimethoxyflavone (7), atalantoflavone (8), 5-hydroxy-3′,4′,8-trimethoxy-2′′,2′′-dimethylpyrano (5′′,6′′:6,7)-flavone (9), and 3′,4′,5,8-tetramethoxy-2′′,2′′-dimethylpyrano (5′′,6′′:6,7)-flavone (10). The structures of the isolated compounds were elucidated by means of spectroscopic tools including 1D and 2D NMR, UV, IR, and mass spectroscopy. Cytotoxic activities of the isolated compounds were evaluated against human cervical carcinoma HeLa, human hepatocellular carcinoma HepG2, and human breast carcinoma MCF-7. Compound 2 was the most potent cytotoxic agent against HeLa cells with an IC50 0.079 μM. PMID:25114960

  5. Synthesis and cytotoxic activities of semisynthetic zearalenone analogues.

    PubMed

    Tadpetch, Kwanruthai; Kaewmee, Benyapa; Chantakaew, Kittisak; Kantee, Kawalee; Rukachaisirikul, Vatcharin; Phongpaichit, Souwalak

    2016-08-01

    Zearalenone is a β-resorcylic acid macrolide with various biological activities. Herein we report the synthesis and cytotoxic activities of 34 zearalenone analogues against human oral epidermoid carcinoma (KB) and human breast adenocarcinoma (MCF-7) cells as well as noncancerous Vero cells. Some zearalenone analogues showed moderately enhanced cytotoxic activities against the two cancer cell lines. We have discovered the potential lead compounds with diminished or no cytotoxicity to Vero cells. Preliminary structure-activity relationship studies revealed that the double bond at the 1' and 2' positions of zearalenone core was crucial for cytotoxic activities on both cell lines. In addition, for zearalenol analogues, the unprotected hydroxyl group at C-2 and an alkoxy substituent at C-4 played key roles on cytotoxic effects of both cell lines. PMID:27311894

  6. Immunohistochemical identification of cytotoxic lymphocytes using human perforin monoclonal antibody.

    PubMed Central

    Hameed, A.; Olsen, K. J.; Cheng, L.; Fox, W. M.; Hruban, R. H.; Podack, E. R.

    1992-01-01

    Perforin is a potent cytolytic pore-forming protein expressed in cytoplasmic granules of cytotoxic T lymphocytes and natural killer cells. A new monoclonal antibody raised against human perforin was used to detect both in vitro and in vivo perforin expression in cytotoxic cells. Immunohistochemical analysis of human peripheral blood mononuclear cells cultured in recombinant interleukin-2 (rIL-2) showed strong granular cytoplasmic staining of the IL-2 activated cytotoxic cells. Fresh-frozen tissue sections from patients with heart allograft rejection were also stained. Strong granular cytoplasmic staining of the mononuclear inflammatory infiltrate characteristic for perforin in cardiac allograft rejection was observed. The detection and quantitative analysis of perforin-associated cytotoxic cells by the human anti-perforin monoclonal antibody will help to evaluate the significance of these functionally distinct cytotoxic cells in human tissue. Images Figure 1 PMID:1374586

  7. pH-Responsive Theranostic Polymer-Caged Nanobins (PCNs): Enhanced Cytotoxicity and T1 MRI Contrast by Her2-Targeting

    PubMed Central

    Hong, Bong Jin; Swindell, Elden P.; MacRenaris, Keith W.; Hankins, Patrick L.; Chipre, Anthony J.; Mastarone, Daniel J.; Ahn, Richard W.; Meade, Thomas J.; O’Halloran, Thomas V.

    2014-01-01

    A PCN theranostic platform comprises a doxorubicin (DXR)-loaded liposomal core and an acid-sensitive polymer shell that is functionalized with Herceptin and GdIII-based MRI contrast agents. In vitro testing reveals a 14-fold increase in DXR-based cytotoxicity versus a non-targeted analogue and an 120-fold improvement in cellular GdIII–uptake in comparison with clinically approved DOTA-GdIII, leading to significant T1 MRI contrast enhancement. PMID:24516291

  8. Effects of extracellular pH and hypoxia on the function and development of antigen-specific cytotoxic T lymphocytes.

    PubMed

    Nakagawa, Yohko; Negishi, Yasuyuki; Shimizu, Masumi; Takahashi, Megumi; Ichikawa, Masao; Takahashi, Hidemi

    2015-10-01

    The major effector cells for cellular adaptive immunity are CD8(+) cytotoxic T lymphocytes (CTLs), which can recognize and kill virus-infected cells and tumor cells. Although CTLs exhibit strong cytolytic activity against target cells in vitro, a number of studies have demonstrated that their function is often impaired within tumors. Nevertheless, CTLs can regain their cytotoxic ability after escaping from the tumor environment, suggesting that the milieu created by tumors may affect the function of CTLs. As for the tumor environment, the patho-physiological situation present in vivo has been shown to differ from in vitro experimental conditions. In particular, low pH and hypoxia are the most important microenvironmental factors within growing tumors. In the present study, to determine the effect of these factors on CTL function in vivo, we examined the cytolytic activity of CTLs against their targets using murine CTL lines and the induction of these cells from memory cells under low pH or hypoxic conditions using antigen-primed spleen cells. The results indicated that both cytotoxic activity and the induction of functional CTLs were markedly inhibited under low pH. In contrast, in hypoxic conditions, although cytotoxic activity was almost unchanged, the induction of CTLs in vitro showed a slight enhancement, which was completely abrogated in low pH conditions. Therefore, antigen-specific CTL functions may be more vulnerable to low pH than to the oxygen concentration in vivo. The findings shown here provide new therapeutic approaches for controlling tumor growth by retaining CTL cytotoxicity through the maintenance of higher pH conditions. PMID:26209187

  9. Cytotoxic effects of oxysterols produced during ozonolysis of cholesterol in murine GT1-7 hypothalamic neurons.

    PubMed

    Sathishkumar, K; Murthy, Subramanyam N; Uppu, Rao M

    2007-01-01

    Ozone present in the photochemical smog or generated at the inflammatory sites is known to oxidize cholesterol and its 3-acyl esters. The oxidation results in the formation of multiple "ozone-specific" oxysterols, some of which are known to cause abnormalities in the metabolism of cholesterol and exert cytotoxicity. The ozone-specific oxysterols have been shown to favor the formation of atherosclerotic plaques and amyloid fibrils involving pro-oxidant processes. In the present communication, cultured murine GT1-7 hypothalamic neurons were studied in the context of cholesterol metabolism, formation of reactive oxygen species, intracellular Ca2 + levels and cytotoxicity using two most commonly occurring cholesterol ozonolysis products, 3beta- hydroxy-5-oxo-5,6-secocholestan-6-al (ChSeco) and 5beta, 6beta-epoxy-cholesterol (ChEpo). It was found that ChSeco elicited cytotoxicity at lower concentration (IC50 = 21 +/- 2.4 microM) than did ChEpo (IC50 = 43 +/- 3.7 microM). When tested at their IC50 concentrations in GT1-7 cells, both ChSeco and ChEpo resulted in the generation of ROS, the magnitude of which was comparable. N-acetyl-l-cysteine and Trolox attenuated the cytotoxic effects of ChSeco and ChEpo. The intracellular Ca2 + levels were not altered by either ChSeco or ChEpo. Methyl-beta-cyclodextrins, which cause depletion of cellular cholesterol, prevented ChSeco- but not ChEpo-induced cytotoxicity. The cell death caused by ChEpo, but not ChSeco, was prevented by exogenous cholesterol. Although oxidative stress plays a significant role, the results of the present study indicate differences in the pathways of cell death induced by ChSeco and ChEpo in murine GT1-7 hypothalamic neurons. PMID:17164181

  10. Assessment of cytotoxicity of (N-isopropyl acrylamide) and poly(N-isopropyl acrylamide)-coated surfaces.

    PubMed

    Cooperstein, Marta A; Canavan, Heather E

    2013-12-01

    Poly(N-isopropyl acrylamide) (pNIPAM) is one of the most popular stimulus-responsive polymers for research. It is especially of great interest in the field of tissue engineering. While it is known that the NIPAM monomer is toxic, there is little conclusive research on the cytotoxicity of the polymer. In this work, the relative biocompatibility of the NIPAM monomer, pNIPAM, and pNIPAM-coated substrates prepared using different polymerization (free radical and plasma polymerization) and deposition (spin coating and plasma polymerization) techniques was evaluated using appropriate cytotoxicity tests (MTS, Live/Dead, plating efficiency). Four different mammalian cell types (endothelial, epithelial, smooth muscle, and fibroblasts) were used for the cytotoxicity testing. The pNIPAM-coated surfaces were evaluated for their thermoresponse and surface chemistry using X-ray photoelectron spectroscopy and goniometry. We found that while cell viability on pNIPAM surfaces decreases when compared to controls, the viability also seems to be deposition type dependent, with sol-gel based pNIPAM surfaces being the least biocompatible. Long term experiments proved that all pNIPAM-coated surfaces were not cytotoxic to the four cell types evaluated in a direct contact test. Plating efficiency experiments did not show cytotoxicity. Cellular sensitivity to pNIPAM and to the NIPAM monomer varied depending on cell type. Endothelial cells consistently showed decreased viability after 48 hours of exposure to pNIPAM extracts and were more sensitive than the other cell lines to impurities in the polymer. PMID:24706136

  11. Label-free and quantitative evaluation of cytotoxicity based on surface nanostructure and biophysical property of cells utilizing AFM.

    PubMed

    Lee, Young Ju; Lee, Gi-Ja; Kang, Sung Wook; Cheong, Youjin; Park, Hun-Kuk

    2013-06-01

    In this study, the four commonly used cytotoxicity assays and the mechanical properties as evaluated by atomic force microscopy (AFM) were compared in a cellular system. A cytotoxicity assay is the first and most essential test to evaluate biocompatibility of various toxic substances. Many of the cytotoxicity methods require complicated and labor-intensive process, as well as introduce experimental error. In addition, these methods cannot provide instantaneous and quantitative cell viability information. AFM has become an exciting analytical tool in medical, biological, and biophysical research due to its unique abilities. AFM-based force-distance curve measurements precisely measure the changes in the biophysical properties of the cell. Therefore, we observed the morphological changes and mechanical property changes in L929 cells following sodium lauryl sulfate (SLS) treatment utilizing AFM. AFM imaging showed that the toxic effects of SLS changed not only the spindle-like shape of L929 cells into a round shape, but also made a rough cell surface. As the concentration of SLS was increased, the surface roughness of L929 cell was increased, and stiffness decreased. We confirmed that inhibition of proliferation clearly increased with increases in SLS concentration based on results from MTT, WST, neutral red uptake, and LIVE/DEAD viability/cytotoxicity assays. The estimated IC₅₀ value by AFM analysis was similar to those of other conventional assays and was included within the 95% confidence interval range. We suggest that an AFM quantitative analysis of the morphological and biophysical changes in cells can be utilized as a new method for evaluating cytotoxicity. PMID:23582483

  12. Reduced cytotoxicity and enhanced bioactivity of cationic antimicrobial peptides liposomes in cell cultures and 3D epidermis model against HSV.

    PubMed

    Ron-Doitch, Sapir; Sawodny, Beate; Kühbacher, Andreas; David, Mirjam M Nordling; Samanta, Ayan; Phopase, Jaywant; Burger-Kentischer, Anke; Griffith, May; Golomb, Gershon; Rupp, Steffen

    2016-05-10

    Cationic antimicrobial peptides (AMPs) are part of the innate immunity, and act against a wide variety of pathogenic microorganisms by perturbation of the microorganism's plasma membrane. Although attractive for clinical applications, these agents suffer from limited stability and activity in vivo, as well as non-specific interaction with host biological membranes, leading to cytotoxic adverse effects. We hypothesized that encapsulation of AMPs within liposomes could result in reduced cytotoxicity, and with enhanced stability as well as bioactivity against herpes simplex virus 1 (HSV-1). We formulated nano-sized liposomal formulations of LL-37 and indolicidin, and their physicochemical properties, cellular uptake, in vitro cytotoxicity and antiviral efficacy have been determined. Lower cytotoxicity of LL-37 liposomes was found in comparison to indolicidin liposomes attributed to the superior physicochemical properties, and to the different degree of interaction with the liposomal membrane. The disc-like shaped LL-37 liposomes (106.8±10.1nm, shelf-life stability of >1year) were taken up more rapidly and to a significantly higher extent than the free peptide by human keratinocyte cell line (HaCaT), remained intact within the cells, followed by release of the active peptide within the cytoplasm and migration of the vesicles' lipids to the plasma membrane. LL-37 liposomes were found significantly less toxic than both the free agent and liposomal indolicidin. In the new 3D epidermis model (immortalized primary keratinocytes) liposomal LL-37 treatment (>20μM), but not free LL-37, efficiently protected the epidermis, inhibiting HSV-1 infection. This positive antiviral effect was obtained with no cytotoxicity even at very high concentrations (400μM). Thus, the antiviral activity of encapsulated LL-37 was significantly improved, expanding its therapeutic window. Liposomal LL-37 appears to be a promising delivery system for HSV therapy. PMID:27012977

  13. Molecular Characterization of the Cytotoxic Mechanism of Multiwall Carbon Nanotubes and Nano-Onions on Human Skin Fibroblast

    PubMed Central

    Ding, Lianghao; Stilwell, Jackie; Zhang, Tingting; Elboudwarej, Omeed; Jiang, Huijian; Selegue, John P.; Cooke, Patrick A.; Gray, Joe W.; Chen, Fanqing Frank

    2009-01-01

    The increasing use of nanotechnology in consumer products and medical applications underlies the importance of understanding its potential toxic effects to people and the environment. Although both fullerene and carbon nanotubes have been demonstrated to accumulate to cytotoxic levels within organs of various animal models and cell types and carbon nanomaterials have been exploited for cancer therapies, the molecular and cellular mechanisms for cytotoxicity of this class of nanomaterial are not yet fully apparent. To address this question, we have performed whole genome expression array analysis and high content image analysis based phenotypic measurements on human skin fibroblast cell populations exposed to multiwall carbon nano-onions (MWCNOs) and multiwall carbon nanotubes (MWCNTs). Here we demonstrate that exposing cells to MWCNOs and MWCNTs at cytotoxic doses induces cell cycle arrest and increases apoptosis/necrosis. Expression array analysis indicates that multiple cellular pathways are perturbed after exposure to these nanomaterials at these doses, with material-specific toxigenomic profiles observed. Moreover, there are also distinct qualitative and quantitative differences in gene expression profiles, with each material at different dosage levels (6 and 0.6 μg/mL for MWCNO and 0.6 and 0.06 μg/mL for MWCNT). MWCNO and MWCNT exposure activates genes involved in cellular transport, metabolism, cell cycle regulation, and stress response. MWCNTs induce genes indicative of a strong immune and inflammatory response within skin fibroblasts, while MWCNO changes are concentrated in genes induced in response to external stimuli. Promoter analysis of the microarray results demonstrate that interferon and p38/ERK-MAPK cascades are critical pathway components in the induced signal transduction contributing to the more adverse effects observed upon exposure to MWCNTs as compared to MWCNOs. PMID:16351195

  14. Resistance of cytotoxic T lymphocytes to lysis by a clone of cytotoxic T lymphocytes.

    PubMed Central

    Kranz, D M; Eisen, H N

    1987-01-01

    To investigate how cytotoxic T lymphocytes (CTL) avoid killing themselves when they destroy target cells, we compared 20 different cell lines as target cells, including several CTL cell lines, for their susceptibility to lysis by CTL. Variations in recognition of this diverse set of target cells was circumvented by attaching to all of them a monoclonal antibody to the antigen-specific receptor of a cloned CTL cell line (clone 2C) and using the 2C cell line as the standard aggressor or effector cell. All of the nine tumor cell lines and the four noncytolytic T-helper cell lines tested as targets were highly susceptible to lysis by the aggressor CTL, but seven cytotoxic T-cell lines (six CTL and one T-helper cell line with cytotoxic activity) were largely resistant. These results, and the use of the lectin Con A as an alternative means for triggering CTL activity, point clearly to a level of resistance that could enable CTL to avoid their own destruction when they lyse target cells. The resistance of the cytolytic T cells did not appear to be accompanied by a similar resistance to complement-mediated lysis, indicating that mechanisms of CTL-mediated and complement-mediated lysis are not identical. PMID:2953028

  15. Nitric oxide-releasing prodrug triggers cancer cell death through deregulation of cellular redox balance.

    PubMed

    Maciag, Anna E; Holland, Ryan J; Robert Cheng, Y-S; Rodriguez, Luis G; Saavedra, Joseph E; Anderson, Lucy M; Keefer, Larry K

    2013-01-01

    JS-K is a nitric oxide (NO)-releasing prodrug of the O (2)-arylated diazeniumdiolate family that has demonstrated pronounced cytotoxicity and antitumor properties in a variety of cancer models both in vitro and in vivo. The current study of the metabolic actions of JS-K was undertaken to investigate mechanisms of its cytotoxicity. Consistent with model chemical reactions, the activating step in the metabolism of JS-K in the cell is the dearylation of the diazeniumdiolate by glutathione (GSH) via a nucleophilic aromatic substitution reaction. The resulting product (CEP/NO anion) spontaneously hydrolyzes, releasing two equivalents of NO. The GSH/GSSG redox couple is considered to be the major redox buffer of the cell, helping maintain a reducing environment under basal conditions. We have quantified the effects of JS-K on cellular GSH content, and show that JS-K markedly depletes GSH, due to JS-K's rapid uptake and cascading release of NO and reactive nitrogen species. The depletion of GSH results in alterations in the redox potential of the cellular environment, initiating MAPK stress signaling pathways, and inducing apoptosis. Microarray analysis confirmed signaling gene changes at the transcriptional level and revealed alteration in the expression of several genes crucial for maintenance of cellular redox homeostasis, as well as cell proliferation and survival, including MYC. Pre-treating cells with the known GSH precursor and nucleophilic reducing agent N-acetylcysteine prevented the signaling events that lead to apoptosis. These data indicate that multiplicative depletion of the reduced glutathione pool and deregulation of intracellular redox balance are important initial steps in the mechanism of JS-K's cytotoxic action. PMID:24024144

  16. Nitric oxide-releasing prodrug triggers cancer cell death through deregulation of cellular redox balance☆

    PubMed Central

    Maciag, Anna E.; Holland, Ryan J.; Robert Cheng, Y.-S.; Rodriguez, Luis G.; Saavedra, Joseph E.; Anderson, Lucy M.; Keefer, Larry K.

    2013-01-01

    JS-K is a nitric oxide (NO)-releasing prodrug of the O2-arylated diazeniumdiolate family that has demonstrated pronounced cytotoxicity and antitumor properties in a variety of cancer models both in vitro and in vivo. The current study of the metabolic actions of JS-K was undertaken to investigate mechanisms of its cytotoxicity. Consistent with model chemical reactions, the activating step in the metabolism of JS-K in the cell is the dearylation of the diazeniumdiolate by glutathione (GSH) via a nucleophilic aromatic substitution reaction. The resulting product (CEP/NO anion) spontaneously hydrolyzes, releasing two equivalents of NO. The GSH/GSSG redox couple is considered to be the major redox buffer of the cell, helping maintain a reducing environment under basal conditions. We have quantified the effects of JS-K on cellular GSH content, and show that JS-K markedly depletes GSH, due to JS-K's rapid uptake and cascading release of NO and reactive nitrogen species. The depletion of GSH results in alterations in the redox potential of the cellular environment, initiating MAPK stress signaling pathways, and inducing apoptosis. Microarray analysis confirmed signaling gene changes at the transcriptional level and revealed alteration in the expression of several genes crucial for maintenance of cellular redox homeostasis, as well as cell proliferation and survival, including MYC. Pre-treating cells with the known GSH precursor and nucleophilic reducing agent N-acetylcysteine prevented the signaling events that lead to apoptosis. These data indicate that multiplicative depletion of the reduced glutathione pool and deregulation of intracellular redox balance are important initial steps in the mechanism of JS-K's cytotoxic action. PMID:24024144

  17. Cellular immune responses to HIV

    NASA Astrophysics Data System (ADS)

    McMichael, Andrew J.; Rowland-Jones, Sarah L.

    2001-04-01

    The cellular immune response to the human immunodeficiency virus, mediated by T lymphocytes, seems strong but fails to control the infection completely. In most virus infections, T cells either eliminate the virus or suppress it indefinitely as a harmless, persisting infection. But the human immunodeficiency virus undermines this control by infecting key immune cells, thereby impairing the response of both the infected CD4+ T cells and the uninfected CD8+ T cells. The failure of the latter to function efficiently facilitates the escape of virus from immune control and the collapse of the whole immune system.

  18. Quantum cellular automata without particles

    NASA Astrophysics Data System (ADS)

    Meyer, David A.; Shakeel, Asif

    2016-01-01

    Quantum cellular automata (QCA) constitute space and time homogeneous discrete models for quantum field theories (QFTs). Although QFTs are defined without reference to particles, computations are done in terms of Feynman diagrams, which are explicitly interpreted in terms of interacting particles. Similarly, the easiest QCA to construct are quantum lattice gas automata (QLGA). A natural question then is, which QCA are not QLGA? Here we construct a nontrivial example of such a QCA; it provides a simple model in 1 +1 dimensions with no particle interpretation at the scale where the QCA dynamics are homogeneous.

  19. Universal map for cellular automata

    NASA Astrophysics Data System (ADS)

    García-Morales, V.

    2012-08-01

    A universal map is derived for all deterministic 1D cellular automata (CAs) containing no freely adjustable parameters and valid for any alphabet size and any neighborhood range (including non-symmetrical neighborhoods). The map can be extended to an arbitrary number of dimensions and topologies and to arbitrary order in time. Specific CA maps for the famous Conway's Game of Life and Wolfram's 256 elementary CAs are given. An induction method for CAs, based in the universal map, allows mathematical expressions for the orbits of a wide variety of elementary CAs to be systematically derived.

  20. Therapeutic cloning and cellular reprogramming.

    PubMed

    Rodriguez, Ramon M; Ross, Pablo J; Cibelli, Jose B

    2012-01-01

    Embryonic stem cells are capable of differentiating into any cell-type present in an adult organism, and constitute a renewable source of tissue for regenerative therapies. The transplant of allogenic stem cells is challenging due to the risk of immune rejection. Nevertheless, somatic cell reprogramming techniques allow the generation of isogenic embryonic stem cells, genetically identical to the patient. In this chapter we will discuss the cellular reprogramming techniques in the context of regenerative therapy and the biological and technical barriers that they will need to overcome before clinical use. PMID:22457116

  1. Symmetry analysis of cellular automata

    NASA Astrophysics Data System (ADS)

    García-Morales, V.

    2013-01-01

    By means of B-calculus [V. García-Morales, Phys. Lett. A 376 (2012) 2645] a universal map for deterministic cellular automata (CAs) has been derived. The latter is shown here to be invariant upon certain transformations (global complementation, reflection and shift). When constructing CA rules in terms of rules of lower range a new symmetry, “invariance under construction” is uncovered. Modular arithmetic is also reformulated within B-calculus and a new symmetry of certain totalistic CA rules, which calculate the Pascal simplices modulo an integer number p, is then also uncovered.

  2. Primitive control of cellular metabolism

    NASA Technical Reports Server (NTRS)

    Mitz, M. A.

    1974-01-01

    It is pointed out that control substances must have existed from the earliest times in the evolution of life and that the same control mechanisms must exist today. The investigation reported is concerned with the concept that carbon dioxide is a primitive regulator of cell function. The effects of carbon dioxide on cellular materials are examined, taking into account questions of solubilization, dissociation, changes of charge, stabilization, structural changes, wettability, the exclusion of other gases, the activation of compounds, changes in plasticity, and changes in membrane permeability.

  3. The Cellular Basis of Aging

    PubMed Central

    Scoggin, Charles H.

    1981-01-01

    Normal cells have only a finite life span before they die. The process known as aging may occur as a result of continued damage to the cell or as a result of expression of predetermined information within the genetic structure of the cell. Both processes lead to progressive cellular dysfunction which is evidenced by the organs of the body as aging. By understanding how individual cells age we will gain insight into how the body as a whole ages. The impact of such knowledge on science and society is a matter of both conjecture and concern. PMID:7336718

  4. Protein accounting in the cellular economy

    PubMed Central

    Vázquez-Laslop, Nora; Mankin, Alexander S.

    2014-01-01

    Knowing the copy number of cellular proteins is critical for understanding cell physiology. By being able to measure the absolute synthesis rates of the majority of cellular proteins, Li et al. (2014) gain insights into key aspects of translation regulation and fundamental principles of cellular strategies to adjust protein synthesis according to the needs. PMID:24766801

  5. Protein accounting in the cellular economy.

    PubMed

    Vázquez-Laslop, Nora; Mankin, Alexander S

    2014-04-24

    Knowing the copy number of cellular proteins is critical for understanding cell physiology. By being able to measure the absolute synthesis rates of the majority of cellular proteins, Li et al. gain insights into key aspects of translation regulation and fundamental principles of cellular strategies to adjust protein synthesis according to the functional needs. PMID:24766801

  6. Anesthetic propofol overdose causes endothelial cytotoxicity in vitro and endothelial barrier dysfunction in vivo

    SciTech Connect

    Lin, Ming-Chung; Chen, Chia-Ling; Yang, Tsan-Tzu; Choi, Pui-Ching; Hsing, Chung-Hsi; Lin, Chiou-Feng

    2012-12-01

    An overdose and a prolonged treatment of propofol may cause cellular cytotoxicity in multiple organs and tissues such as brain, heart, kidney, skeletal muscle, and immune cells; however, the underlying mechanism remains undocumented, particularly in vascular endothelial cells. Our previous studies showed that the activation of glycogen synthase kinase (GSK)-3 is pro-apoptotic in phagocytes during overdose of propofol treatment. Regarding the intravascular administration of propofol, we therefore hypothesized that propofol overdose also induces endothelial cytotoxicity via GSK-3. Propofol overdose (100 μg/ml) inhibited growth in human arterial and microvascular endothelial cells. After treatment, most of the endothelial cells experienced caspase-independent necrosis-like cell death. The activation of cathepsin D following lysosomal membrane permeabilization (LMP) determined necrosis-like cell death. Furthermore, propofol overdose also induced caspase-dependent apoptosis, at least in part. Caspase-3 was activated and acted downstream of mitochondrial transmembrane potential (MTP) loss; however, lysosomal cathepsins were not required for endothelial cell apoptosis. Notably, activation of GSK-3 was essential for propofol overdose-induced mitochondrial damage and apoptosis, but not necrosis-like cell death. Intraperitoneal administration of a propofol overdose in BALB/c mice caused an increase in peritoneal vascular permeability. These results demonstrate the cytotoxic effects of propofol overdose, including cathepsin D-regulated necrosis-like cell death and GSK-3-regulated mitochondrial apoptosis, on endothelial cells in vitro and the endothelial barrier dysfunction by propofol in vivo. Highlights: ► Propofol overdose causes apoptosis and necrosis in endothelial cells. ► Propofol overdose triggers lysosomal dysfunction independent of autophagy. ► Glycogen synthase kinase-3 facilitates propofol overdose-induced apoptosis. ► Propofol overdose causes an increase

  7. Sorafenib enhances proteasome inhibitor-mediated cytotoxicity via inhibition of unfolded protein response and keratin phosphorylation

    SciTech Connect

    Honma, Yuichi; Harada, Masaru

    2013-08-15

    Hepatocellular carcinoma (HCC) is highly resistant to conventional systemic therapies and prognosis for advanced HCC patients remains poor. Recent studies of the molecular mechanisms responsible for tumor initiation and progression have identified several potential molecular targets in HCC. Sorafenib is a multi-kinase inhibitor shown to have survival benefits in advanced HCC. It acts by inhibiting the serine/threonine kinases and the receptor type tyrosine kinases. In preclinical experiments sorafenib had anti-proliferative activity in hepatoma cells and it reduced tumor angiogenesis and increased apoptosis. Here, we demonstrate for the first time that the cytotoxic mechanisms of sorafenib include its inhibitory effects on protein ubiquitination, unfolded protein response (UPR) and keratin phosphorylation in response to endoplasmic reticulum (ER) stress. Moreover, we show that combined treatment with sorafenib and proteasome inhibitors (PIs) synergistically induced a marked increase in cell death in hepatoma- and hepatocyte-derived cells. These observations may open the way to potentially interesting treatment combinations that may augment the effect of sorafenib, possibly including drugs that promote ER stress. Because sorafenib blocked the cellular defense mechanisms against hepatotoxic injury not only in hepatoma cells but also in hepatocyte-derived cells, we must be careful to avoid severe liver injury. -- Graphical abstract: Display Omitted -- Highlights: •We examined the cytotoxic mechanisms of sorafenib in hepatoma cells. •Sorafenib induces cell death via apoptotic and necrotic fashion. •Sorafenib inhibits protein ubiquitination and unfolded protein response. •Autophagy induced by sorafenib may affect its cytotoxicity. •Sorafenib inhibits keratin phosphorylation and cytoplasmic inclusion formation.

  8. Cytotoxicity of mitochondria-targeted resveratrol derivatives: interactions with respiratory chain complexes and ATP synthase.

    PubMed

    Sassi, Nicola; Mattarei, Andrea; Azzolini, Michele; Szabo', Ildiko'; Paradisi, Cristina; Zoratti, Mario; Biasutto, Lucia

    2014-10-01

    We recently reported that mitochondria-targeted derivatives of resveratrol are cytotoxic in vitro, selectively inducing mostly necrotic death of fast-growing and tumoral cells when supplied in the low μM range (N. Sassi et al., Curr. Pharm. Des. 2014). Cytotoxicity is due to H2O2 produced upon accumulation of the compounds into mitochondria. We investigate here the mechanisms underlying ROS generation and mitochondrial depolarization caused by these agents. We find that they interact with the respiratory chain, especially complexes I and III, causing superoxide production. "Capping" free hydroxyls with acetyl or methyl groups increases their effectiveness as respiratory chain inhibitors, promoters of ROS generation and cytotoxic agents. Exposure to the compounds also induces an increase in the occurrence of short transient [Ca(2+)] "spikes" in the cells. This increase is unrelated to ROS production, and it is not the cause of cell death. These molecules furthermore inhibit the F0F1 ATPase. When added to oligomycin-treated cells, the acetylated/methylated ones cause a recovery of the cellular oxygen consumption rates depressed by oligomycin. Since a protonophoric futile cycle which might account for the uncoupling effect is impossible, we speculate that the compounds may cause the transformation of the ATP synthase and/or respiratory chain complex(es) into a conduit for uncoupled proton translocation. Only in the presence of excess oligomycin the most effective derivatives appear to induce the mitochondrial permeability transition (MPT) within the cells. This may be considered to provide circumstantial support for the idea that the ATP synthase is the molecular substrate for the MPT pore. PMID:24997425

  9. A Cytoplasmic Form of Gaussia luciferase Provides a Highly Sensitive Test for Cytotoxicity

    PubMed Central

    Tsuji, Saori; Ohbayashi, Tetsuya; Yamakage, Kohji; Oshimura, Mitsuo; Tada, Masako

    2016-01-01

    The elimination of unfavorable chemicals from our environment and commercial products requires a sensitive and high-throughput in vitro assay system for drug-induced hepatotoxicity. Some previous methods for evaluating hepatotoxicity measure the amounts of cytoplasmic enzymes secreted from damaged cells into the peripheral blood or culture medium. However, most of these enzymes are proteolytically digested in the extracellular milieu, dramatically reducing the sensitivity and reliability of such assays. Other methods measure the decrease in cell viability following exposure to a compound, but such endpoint assays are often confounded by proliferation of surviving cells that replace dead or damaged cells. In this study, with the goal of preventing false-negative diagnoses, we developed a sensitive luminometric cytotoxicity test using a stable form of luciferase. Specifically, we converted Gaussia luciferase (G-Luc) from an actively secreted form to a cytoplasmic form by adding an ER-retention signal composed of the four amino acids KDEL. The bioluminescent signal was >30-fold higher in transgenic HepG2 human hepatoblastoma cells expressing G-Luc+KDEL than in cells expressing wild-type G-Luc. Moreover, G-Luc+KDEL secreted from damaged cells was stable in culture medium after 24 hr at 37°C. We evaluated the accuracy of our cytotoxicity test by subjecting identical samples obtained from chemically treated transgenic HepG2 cells to the G-Luc+KDEL assay and luminometric analyses based on secretion of endogenous adenylate kinase or cellular ATP level. Time-dependent accumulation of G-Luc+KDEL in the medium increased the sensitivity of our assay above those of existing tests. Our findings demonstrate that strong and stable luminescence of G-Luc+KDEL in human hepatocyte-like cells, which have high levels of metabolic activity, make it suitable for use in a high-throughput screening system for monitoring time-dependent cytotoxicity in a limited number of cells. PMID

  10. Metabolic Imaging to Assess Treatment Response to Cytotoxic and Cytostatic Agents

    PubMed Central

    Serkova, Natalie J.; Eckhardt, S. Gail

    2016-01-01

    For several decades, cytotoxic chemotherapeutic agents were considered the basis of anticancer treatment for patients with metastatic tumors. A decrease in tumor burden, assessed by volumetric computed tomography and magnetic resonance imaging, according to the response evaluation criteria in solid tumors (RECIST), was considered as a radiological response to cytotoxic chemotherapies. In addition to RECIST-based dimensional measurements, a metabolic response to cytotoxic drugs can be assessed by positron emission tomography (PET) using 18F-fluoro-thymidine (FLT) as a radioactive tracer for drug-disrupted DNA synthesis. The decreased 18FLT-PET uptake is often seen concurrently with increased apparent diffusion coefficients by diffusion-weighted imaging due to chemotherapy-induced changes in tumor cellularity. Recently, the discovery of molecular origins of tumorogenesis led to the introduction of novel signal transduction inhibitors (STIs). STIs are targeted cytostatic agents; their effect is based on a specific biological inhibition with no immediate cell death. As such, tumor size is not anymore a sensitive end point for a treatment response to STIs; novel physiological imaging end points are desirable. For receptor tyrosine kinase inhibitors as well as modulators of the downstream signaling pathways, an almost immediate inhibition in glycolytic activity (the Warburg effect) and phospholipid turnover (the Kennedy pathway) has been seen by metabolic imaging in the first 24 h of treatment. The quantitative imaging end points by magnetic resonance spectroscopy and metabolic PET (including 18F-fluoro-deoxy-glucose, FDG, and total choline) provide an early treatment response to targeted STIs, before a reduction in tumor burden can be seen. PMID:27471678

  11. Involvement of ER stress and activation of apoptotic pathways in fisetin induced cytotoxicity in human melanoma.

    PubMed

    Syed, Deeba N; Lall, Rahul K; Chamcheu, Jean Christopher; Haidar, Omar; Mukhtar, Hasan

    2014-12-01

    The prognosis of malignant melanoma remains poor in spite of recent advances in therapeutic strategies for the deadly disease. Fisetin, a dietary flavonoid is currently being investigated for its growth inhibitory properties in various cancer models. We previously showed that fisetin inhibited melanoma growth in vitro and in vivo. Here, we evaluated the molecular basis of fisetin induced cytotoxicity in metastatic human melanoma cells. Fisetin treatment induced endoplasmic reticulum (ER) stress in highly aggressive A375 and 451Lu human melanoma cells, as revealed by up-regulation of ER stress markers including IRE1α, XBP1s, ATF4 and GRP78. Time course analysis indicated that the ER stress was associated with activation of the extrinsic and intrinsic apoptotic pathways. Fisetin treated 2-D melanoma cultures displayed autophagic response concomitant with induction of apoptosis. Prolonged treatment (16days) with fisetin in a 3-D reconstituted melanoma model resulted in inhibition of melanoma progression with significant apoptosis, as evidenced by increased staining of cleaved Caspase-3 in the treated constructs. However, no difference in the expression of autophagic marker LC-3 was noted between treated and control groups. Fisetin treatment to 2-D melanoma cultures resulted in phosphorylation and activation of the multifunctional AMP-activated protein kinase (AMPK) involved in the regulation of diverse cellular processes, including autophagy and apoptosis. Silencing of AMPK failed to prevent cell death indicating that fisetin induced cytotoxicity is mediated through both AMPK-dependent and -independent mechanisms. Taken together, our studies confirm apoptosis as the primary mechanism through which fisetin inhibits melanoma cell growth and that activation of both extrinsic and intrinsic pathways contributes to fisetin induced cytotoxicity. PMID:25016296

  12. Intracellular expression of a single domain antibody reduces cytotoxicity of 15-acetyldeoxynivalenol in yeast.

    PubMed

    Doyle, Patrick J; Saeed, Hanaa; Hermans, Anne; Gleddie, Steve C; Hussack, Greg; Arbabi-Ghahroudi, Mehdi; Seguin, Charles; Savard, Marc E; Mackenzie, C Roger; Hall, J Christopher

    2009-12-11

    15-Acetyldeoxynivalenol (15-AcDON) is a low molecular weight sesquiterpenoid trichothecene mycotoxin associated with Fusarium ear rot of maize and Fusarium head blight of small grain cereals. The accumulation of mycotoxins such as deoxynivalenol (DON) and 15-AcDON within harvested grain is subject to stringent regulation as both toxins pose dietary health risks to humans and animals. These toxins inhibit peptidyltransferase activity, which in turn limits eukaryotic protein synthesis. To assess the ability of intracellular antibodies (intrabodies) to modulate mycotoxin-specific cytotoxocity, a gene encoding a camelid single domain antibody fragment (V(H)H) with specificity and affinity for 15-AcDON was expressed in the methylotropic yeast Pichia pastoris. Cytotoxicity and V(H)H immunomodulation were assessed by continuous measurement of cellular growth. At equivalent doses, 15-AcDON was significantly more toxic to wild-type P. pastoris than was DON. In turn, DON was orders of magnitude more toxic than 3-acetyldeoxynivalenol. Intracellular expression of a mycotoxin-specific V(H)H within P. pastoris conveyed significant (p = 0.01) resistance to 15-AcDON cytotoxicity at doses ranging from 20 to 100 mug.ml(-1). We also documented a biochemical transformation of DON to 15-AcDON to account for the attenuation of DON cytotoxicity at 100 and 200 mug.ml(-1). The proof of concept established within this eukaryotic system suggests that in planta V(H)H expression may lead to enhanced tolerance to mycotoxins and thereby limit Fusarium infection of commercial agricultural crops. PMID:19783651

  13. Short chain fatty acids and cadmium cytotoxicity in ROS 17/2. 8 cells

    SciTech Connect

    Thomas, D.J.; Angle, C.R.; Swanson, S.A. )

    1991-03-11

    ROS 17/2.8 rat osteosarcoma cells are extremely sensitive to the cytotoxic effects of Cd. In naive cells, sensitivity to Cd is associated with poor inducibility of metallothionein (MT). Treatment of ROS 17/2.8 cells with Na butyrate (NaB) results in increased resistance to Cd cytotoxicity and increased MT gene expression. The relation between the structure of short chain fatty acids and the alterations of Cd cytotoxicity in ROS 17/2.8 cells was investigated by culture of cells in the presence of 1 or 5 mM Na acetate, NaB, methyl butyrate, isobutyric acid, methyl isobutyrate and caproic acid. Among these compounds, only 5 mM NaB significantly increased the survival of ROS cells exposed to 0.1 to 10 {mu}M Cd and only NaB treatment was effective in increasing MT gene inducibility. The role of inhibition of DNA replication by NaB in cell resistance to Cd was examined. Among compounds tested, only 5 mM NaB significantly inhibited DNA synthesis. However, in cells in which DNA synthesis is inhibited by exposure to hydroxyurea, addition and removal of NaB from culture medium modulates cellular resistance to Cd. Hence, the effectiveness of NaB as a modifier of cell response to Cd is not due entirely to changes in cell proliferation. Additionally, rigid structural constraints for effectiveness dictate that only NaB is a potent modifier of resistance to Cd.

  14. Protection against hydrogen peroxide-induced cytotoxicity in PC12 cells by scutellarin.

    PubMed

    Hong, Hao; Liu, Guo-Qing

    2004-04-30

    The present study investigated the protective actions of the antioxidant scutellarin against the cytotoxicity produced by exposure to H2O2 in PC12 cells. This was done by assaying for MTT (3,(4,5-dimethylthiazole-2-yl)2,5-diphenyl-tetrazolium bromide) reduction and lactate dehydrogenase (LDH) release. Reactive oxygen species (ROS) and Ca2+ in cells were evaluated by fluorescent microplate reader using DCFH and Fura 2-AM, respectively, as probes. Lipid peroxidation was quantified using thiobarbituric acid-reactive substances (TBARS). Mitochondrial membrane potential (MMP) was assessed by the retention of rhodamine123 (Rh123), a specific fluorescent cationic dye that is readily sequestered by active mitochondria, depending on their transmembra