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Sample records for natural cellular cytotoxicity

  1. Malignant monoblasts can function as effector cells in natural killer cell and antibody-dependent cellular cytotoxicity assays

    DEFF Research Database (Denmark)

    Hokland, P; Hokland, M; Ellegaard, J

    1981-01-01

    This is the first report describing natural killer (NK) and antibody-dependent cellular cytotoxicity (ADCC) of malignant monoblasts. Pure acute monoblastic leukemia was diagnosed in bone marrow aspirations from two patients by use of conventional cytochemical methods as well as multiple immunolog...... no modulation was seen in ADCC. These findings are discussed in the light of our present knowledge of lymphoid NK cells. Udgivelsesdato: 1981-May...

  2. Simultaneous development of antibody-dependent cellular cytotoxicity (ADCC) and natural killer (NK) activity in irradiated mice reconstituted with bone marrow cells

    International Nuclear Information System (INIS)

    Sihvola, M.; Hurme, M.

    1987-01-01

    Spleen cells from irradiated, bone marrow-reconstituted mice were tested for their ability to mediate antibody-dependent cellular cytotoxicity against P815 target (ADCC-P815), ADCC against sheep red blood cells (ADCC-SRBC), and natural killer (NK) activity judged as YAC-1 lysis at different times after bone marrow reconstitution. Donor-derived ADCC-P815 effectors were found to appear in the spleens 10-12 days after bone marrow reconstitution simultaneously with the appearance of donor-derived NK cells. NK cells recently derived from bone marrow are known to express the Thy-1 antigen; the phenotype of the ''early'' ADCC-P815 effectors was found to be the same as that of NK cells, i.e., Thy-1+, asialo-GM1+. These data suggest that ADCC-P815 effector cells belong to the NK cell population. ADCC-SRBC, in contrast to ADCC-P815 and NK activity, was already high on Day 7 after bone marrow reconstitution. However, it was mediated partly by recipient-derived effectors. ADCC-SRBC effectors were characterized to be different from ADCC-P815 effectors

  3. Antibody-dependent cellular cytotoxicity and skin disease

    International Nuclear Information System (INIS)

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

    1985-01-01

    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

  4. Differential effects of IL-2 and IL-21 on expansion of the CD4+ CD25+ Foxp3+ T regulatory cells with redundant roles in natural killer cell mediated antibody dependent cellular cytotoxicity in chronic lymphocytic leukemia.

    Science.gov (United States)

    Gowda, Aruna; Ramanunni, Asha; Cheney, Carolyn; Rozewski, Darlene; Kindsvogel, Wayne; Lehman, Amy; Jarjoura, David; Caligiuri, Michael; Byrd, John C; Muthusamy, Natarajan

    2010-01-01

    CD4(+) CD25(+) regulatory T cells are expanded in solid and hematological malignancies including chronic lymphocytic leukemia (CLL). Several cytokines and co-stimulatory molecules are required for generation, survival and maintenance of their suppressive effect. We and others have shown direct cytotoxic effect of the novel common gamma chain cytokine interleukin (IL)-21 on primary B cells from CLL patients. Since members of this family of cytokines are known to exhibit their effects on diverse immune cells, we have examined the effects of IL-21 on CLL patient derived regulatory T cell (Treg) induction, expansion and the inhibitory effect on natural killer cells in vitro. We demonstrate here the expression of IL-21 receptor in CD4(+)CD25(High) regulatory cells from CLL patients. In contrast to IL-2, the IL-21 cytokine failed to mediate expansion of regulatory T cells or induced expression of Foxp3 in CD4(+)CD25(Intermediate) or CD4(+)CD25(Dim/-) T cells in whole blood derived from CLL patients. Interestingly, in contrast to their differential effects on expansion of the CD4(+)CD25(+)Foxp3(+)T cells, IL-2 and IL-21 exhibited a redundant role in Treg mediated suppression of NK cell mediated antibody dependent cytotoxicity function. Given the infusion related toxicities and pro-survival effect of IL-2 in CLL, these studies provide a rationale to explore IL-21 as an alternate gamma chain cytokine in CLL therapy.

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

    Science.gov (United States)

    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.

  6. The cellular basis of skin injury after cytotoxic insult

    International Nuclear Information System (INIS)

    Potten, C.S.

    1986-01-01

    It is concluded that although the major target in terms of radiation damage is undoubtedly the epidermis, the skin is a complex tissue made up of many inter-dependent components each of which may constitute an important secondary target. Damage to each component has been considered at the cellular level. The precise inter-relationships and interdependencies remain somewhat obscure. Even within one site, the epidermis, a comprehensive cellular explanation of the various post-irradiation changes is difficult. Substantial bibliography. (UK)

  7. Environmentally persistent free radicals amplify ultrafine particle mediated cellular oxidative stress and cytotoxicity

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    Balakrishna Shrilatha

    2009-04-01

    Full Text Available Abstract Background Combustion generated particulate matter is deposited in the respiratory tract and pose a hazard to the lungs through their potential to cause oxidative stress and inflammation. We have previously shown that combustion of fuels and chlorinated hydrocarbons produce semiquinone-type radicals that are stabilized on particle surfaces (i.e. environmentally persistent free radicals; EPFRs. Because the composition and properties of actual combustion-generated particles are complex, heterogeneous in origin, and vary from day-to-day, we have chosen to use surrogate particle systems. In particular, we have chosen to use the radical of 2-monochlorophenol (MCP230 as the EPFR because we have previously shown that it forms a EPFR on Cu(IIO surfaces and catalyzes formation of PCDD/F. To understand the physicochemical properties responsible for the adverse pulmonary effects of combustion by-products, we have exposed human bronchial epithelial cells (BEAS-2B to MCP230 or the CuO/silica substrate. Our general hypothesis was that the EPFR-containing particle would have greater toxicity than the substrate species. Results Exposure of BEAS-2B cells to our combustion generated particle systems significantly increased reactive oxygen species (ROS generation and decreased cellular antioxidants resulting in cell death. Resveratrol treatment reversed the decline in cellular glutathione (GSH, glutathione peroxidase (GPx, and superoxide dismutase (SOD levels for both types of combustion-generated particle systems. Conclusion The enhanced cytotoxicity upon exposure to MCP230 correlated with its ability to generate more cellular oxidative stress and concurrently reduce the antioxidant defenses of the epithelial cells (i.e. reduced GSH, SOD activity, and GPx. The EPFRs in MCP230 also seem to be of greater biological concern due to their ability to induce lipid peroxidation. These results are consistent with the oxidizing nature of the CuO/silica ultrafine

  8. Cellular Transport Mechanisms of Cytotoxic Metallodrugs: An Overview beyond Cisplatin

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    Sarah Spreckelmeyer

    2014-09-01

    Full Text Available The field of medicinal inorganic chemistry has grown consistently during the past 50 years; however, metal-containing coordination compounds represent only a minor proportion of drugs currently on the market, indicating that research in this area has not yet been thoroughly realized. Although platinum-based drugs as cancer chemotherapeutic agents have been widely studied, exact knowledge of the mechanisms governing their accumulation in cells is still lacking. However, evidence suggests active uptake and efflux mechanisms are involved; this may be involved also in other experimental metal coordination and organometallic compounds with promising antitumor activities in vitro and in vivo, such as ruthenium and gold compounds. Such knowledge would be necessary to elucidate the balance between activity and toxicity profiles of metal compounds. In this review, we present an overview of the information available on the cellular accumulation of Pt compounds from in vitro, in vivo and clinical studies, as well as a summary of reports on the possible accumulation mechanisms for different families of experimental anticancer metal complexes (e.g., Ru Au and Ir. Finally, we discuss the need for rationalization of the investigational approaches available to study metallodrug cellular transport.

  9. Cellular uptake and cytotoxicity of positively charged chitosan gold nanoparticles in human lung adenocarcinoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Seon Young; Jang, Soo Hwa [Seoul National University, Laboratory of Veterinary Pharmacology, College of Veterinary Medicine and Institute for Veterinary Science (Korea, Republic of); Park, Jin; Jeong, Saeromi; Park, Jin Ho; Ock, Kwang Su [Soongsil University, Department of Chemistry (Korea, Republic of); Lee, Kangtaek [Yonsei University, Department of Chemical and Biomolecular Engineering (Korea, Republic of); Yang, Sung Ik [Kyung Hee University, College of Environment and Applied Chemistry (Korea, Republic of); Joo, Sang-Woo, E-mail: sjoo@ssu.ac.kr [Soongsil University, Department of Chemistry (Korea, Republic of); Ryu, Pan Dong; Lee, So Yeong, E-mail: leeso@snu.ac.kr [Seoul National University, Laboratory of Veterinary Pharmacology, College of Veterinary Medicine and Institute for Veterinary Science (Korea, Republic of)

    2012-12-15

    Cellular uptake, cytotoxicity, and mechanisms of cytotoxicity of the positively charged Au nanoparticles (NPs) were examined in A549 cells, which are one of the most characterized pulmonary cellular systems. Positively charged Au NPs were prepared by chemical reduction using chitosan. The dimension and surface charge of Au NPs were examined by transmission electron microscopy (TEM), dynamic light scattering, and zeta potential measurements. The uptake of Au NPs into A549 cells was also monitored using TEM and dark-field microscopy (DFM) and z-stack confocal microRaman spectroscopy. DFM live cell imaging was also performed to monitor the entry of chitosan Au NPs in real time. The cytotoxic assay, using both methylthiazol tetrazolium and lactate dehydrogenase assays revealed that positively charged Au NPs decreased cell viability. Flow cytometry, DNA fragmentation, real-time PCR, and western blot analysis suggest that positively charged chitosan Au NPs provoke cell damage through both apoptotic and necrotic pathways.

  10. Cellular uptake and cytotoxicity of positively charged chitosan gold nanoparticles in human lung adenocarcinoma cells

    International Nuclear Information System (INIS)

    Choi, Seon Young; Jang, Soo Hwa; Park, Jin; Jeong, Saeromi; Park, Jin Ho; Ock, Kwang Su; Lee, Kangtaek; Yang, Sung Ik; Joo, Sang-Woo; Ryu, Pan Dong; Lee, So Yeong

    2012-01-01

    Cellular uptake, cytotoxicity, and mechanisms of cytotoxicity of the positively charged Au nanoparticles (NPs) were examined in A549 cells, which are one of the most characterized pulmonary cellular systems. Positively charged Au NPs were prepared by chemical reduction using chitosan. The dimension and surface charge of Au NPs were examined by transmission electron microscopy (TEM), dynamic light scattering, and zeta potential measurements. The uptake of Au NPs into A549 cells was also monitored using TEM and dark-field microscopy (DFM) and z-stack confocal microRaman spectroscopy. DFM live cell imaging was also performed to monitor the entry of chitosan Au NPs in real time. The cytotoxic assay, using both methylthiazol tetrazolium and lactate dehydrogenase assays revealed that positively charged Au NPs decreased cell viability. Flow cytometry, DNA fragmentation, real-time PCR, and western blot analysis suggest that positively charged chitosan Au NPs provoke cell damage through both apoptotic and necrotic pathways.

  11. Natural cytolytic activity in mice with natural or induced cellular defects. I. Differential ability of in vitro interleukin-2 addition to augment natural cytolytic function

    International Nuclear Information System (INIS)

    Ades, E.W.; Hinson, A.; Butler, L.D.

    1986-01-01

    The ability of in vitro addition of recombinant interleukin 2 (rIL-2) to differentially enhance natural cytotoxicity was assessed using cells from mice with natural and induced cellular defects. In vivo treatment with most immunosuppressive or cytoreductive agents, anti-asialo-GM1 antibody, or gamma irradiation dramatically reduced in vitro cytotoxicity against natural killer (NK) sensitive targets by direct reduction in either percentage specific lysis or lytic units per spleen. In most cases, in vitro addition of rIL-2 (at concentrations causing augmented NK function in cells from naive Balb/C mice) enhanced cytotoxic activity of cells from treatment groups to a normal value but not within the rIL-2-enhanced range of nontreated animals. Additionally, cytotoxic activity of cells from animals treated with certain drugs or gamma irradiation could be augmented by rIL-2 when measured by percentage lysis but not lytic units per spleen. In vivo treatment with cyclosporin A did not affect natural cytotoxic activity and addition of rIL-2 augmented the NK activity in a similar fashion to the profile of naive cells. In experiments using cells from beige (C57Bl/6-bg) mice which have a natural defect in NK activity against YAC-1 targets, addition of rIL-2 (at concentrations causing augmented natural cytotoxic function in cells from C57Bl/6 mice) could not effectively enhance in vitro natural cytotoxic function

  12. Natural cytolytic activity in mice with natural or induced cellular defects. I. Differential ability of in vitro interleukin-2 addition to augment natural cytolytic function

    Energy Technology Data Exchange (ETDEWEB)

    Ades, E.W.; Hinson, A.; Butler, L.D.

    1986-08-01

    The ability of in vitro addition of recombinant interleukin 2 (rIL-2) to differentially enhance natural cytotoxicity was assessed using cells from mice with natural and induced cellular defects. In vivo treatment with most immunosuppressive or cytoreductive agents, anti-asialo-GM1 antibody, or gamma irradiation dramatically reduced in vitro cytotoxicity against natural killer (NK) sensitive targets by direct reduction in either percentage specific lysis or lytic units per spleen. In most cases, in vitro addition of rIL-2 (at concentrations causing augmented NK function in cells from naive Balb/C mice) enhanced cytotoxic activity of cells from treatment groups to a normal value but not within the rIL-2-enhanced range of nontreated animals. Additionally, cytotoxic activity of cells from animals treated with certain drugs or gamma irradiation could be augmented by rIL-2 when measured by percentage lysis but not lytic units per spleen. In vivo treatment with cyclosporin A did not affect natural cytotoxic activity and addition of rIL-2 augmented the NK activity in a similar fashion to the profile of naive cells. In experiments using cells from beige (C57Bl/6-bg) mice which have a natural defect in NK activity against YAC-1 targets, addition of rIL-2 (at concentrations causing augmented natural cytotoxic function in cells from C57Bl/6 mice) could not effectively enhance in vitro natural cytotoxic function.

  13. Cytotoxicity and cellular uptake of tri-block copolymer nanoparticles with different size and surface characteristics

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    Bhattacharjee Sourav

    2012-04-01

    Full Text Available Abstract Background Polymer nanoparticles (PNP are becoming increasingly important in nanomedicine and food-based applications. Size and surface characteristics are often considered to be important factors in the cellular interactions of these PNP, although systematic investigations on the role of surface properties on cellular interactions and toxicity of PNP are scarce. Results Fluorescent, monodisperse tri-block copolymer nanoparticles with different sizes (45 and 90 nm and surface charges (positive and negative were synthesized, characterized and studied for uptake and cytotoxicity in NR8383 and Caco-2 cells. All types of PNP were taken up by the cells. The positive smaller PNP45 (45 nm showed a higher cytotoxicity compared to the positive bigger PNP90 (90 nm particles including reduction in mitochondrial membrane potential (ΔΨm, induction of reactive oxygen species (ROS production, ATP depletion and TNF-α release. The negative PNP did not show any cytotoxic effect. Reduction in mitochondrial membrane potential (ΔΨm, uncoupling of the electron transfer chain in mitochondria and the resulting ATP depletion, induction of ROS and oxidative stress may all play a role in the possible mode of action for the cytotoxicity of these PNP. The role of receptor-mediated endocytosis in the intracellular uptake of different PNP was studied by confocal laser scanning microscopy (CLSM. Involvement of size and charge in the cellular uptake of PNP by clathrin (for positive PNP, caveolin (for negative PNP and mannose receptors (for hydroxylated PNP were found with smaller PNP45 showing stronger interactions with the receptors than bigger PNP90. Conclusions The size and surface characteristics of polymer nanoparticles (PNP; 45 and 90 nm with different surface charges play a crucial role in cellular uptake. Specific interactions with cell membrane-bound receptors (clathrin, caveolin and mannose leading to cellular internalization were observed to depend on

  14. Cellular distribution of inorganic mercury and its relation to cytotoxicity in bovine kidney cell cultures

    International Nuclear Information System (INIS)

    Bracken, W.M.; Sharma, R.P.; Bourcier, D.R.

    1984-01-01

    A bovine kidney cell culture system was used to assess what relationship mercuric chloride (HgCl 2 ) uptake and subcellular distribution had to cytotoxicity. Twenty-four-hour incubations with 0.05-50 μM HgCl 2 elicited a concentration-related cytotoxicity. Cellular accumulation of 203 Hg was also concentration-related, with 1.0 nmol/10 6 cells at the IC50. Measurement of Hg uptake over the 24-h exposure period revealed a multiphasic process. Peak accumulation was attained by 1 h and was followed by extrusion and plateauing of intracellular Hg levels. Least-squares regression analysis of the cytotoxicity and cellular uptake data indicated a potential relationship between the Hg uptake and cytotoxicity. However, the subcellular distribution of Hg was not concentration-related. Mitochondria and soluble protein fractions accounted for greater than 65% of the cell-associated Hg at all concentrations. The remaining Hg was distributed between the microsomal (6-10%) and nuclear and cell debris (11-22%) fractions at all concentrations tested. Less than 20% of the total cell-associated Hg was bound with metallothionein-like protein. 31 references, 4 figures, 3 tables

  15. Cytotoxic Natural Products from Marine Sponge-Derived Microorganisms

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    Huawei Zhang

    2017-03-01

    Full Text Available A growing body of evidence indicates that marine sponge-derived microbes possess the potential ability to make prolific natural products with therapeutic effects. This review for the first time provides a comprehensive overview of new cytotoxic agents from these marine microbes over the last 62 years from 1955 to 2016, which are assorted into seven types: terpenes, alkaloids, peptides, aromatics, lactones, steroids, and miscellaneous compounds.

  16. Poly-L-arginine: Enhancing Cytotoxicity and Cellular Uptake of Doxorubicin and Necrotic Cell Death.

    Science.gov (United States)

    Movafegh, Bahareh; Jalal, Razieh; Mohammadi, Zobeideh; Aldaghi, Seyyede Araste

    2018-04-11

    Cell resistance to doxorubicin and its toxicity to healthy tissue reduce its efficiency. The use of cell penetrating peptides as drug delivery system along with doxorubicin is a strategy to reduce its side effects. In this study, the influence of poly-L-arginine on doxorubicin cytotoxicity, its cellular uptake and doxorubicin-induced apoptosis on human prostate cancer DU145 cells are assessed. The cytotoxicity of doxorubicin and poly-L-arginine, alone and in combination, in DU145 cells was evaluated at different exposure times using MTT assay. The influence of poly-L-arginine on doxorubicin delivery into cells was evaluated by fluorescence microscopy and ultraviolet spectroscopy. DAPI and ethidium bromide-acridine orange stainings, flow cytometry using annexin V/propidium iodide, western blot analysis with anti-p21 antibody and caspase-3 activity were used to examine the influence of poly-L-arginine on doxorubicin-induced cell death. Poly-L-arginine had no cytotoxicity at low concentrations and short exposure times. Poly-L-arginine increased the cytotoxic effect of doxorubicin in DU145 cells in a time-dependent manner. But no significant reduction was found in HFF cell viability. Poly-L-arginine seems to facilitate doxorubicin uptake and increase its intracellular concentration. 24 h combined treatment of cells with doxorubicin (0.5 μM) and poly-L-arginine (1 μg ml-1) caused a small increase in doxorubicin-induced apoptosis and significant elevated necrosis in DU145 cells as compared to each agent alone. Conlusion: Our results indicate that poly-L-arginine at lowest and highest concentrations act as proliferation-inducing and antiproliferative agents, respectively. Between these concentrations, poly-L-arginine increases the cellular uptake of doxorubicin and its cytotoxicity through induction of necrosis. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  17. Cellular cytotoxic response induced by highly purified multi-wall carbon nanotube in human lung cells.

    Science.gov (United States)

    Tsukahara, Tamotsu; Haniu, Hisao

    2011-06-01

    Carbon nanotubes, a promising nanomaterial with unique characteristics, have applications in a variety of fields. The cytotoxic effects of carbon nanotubes are partially due to the induction of oxidative stress; however, the detailed mechanisms of nanotube cytotoxicity and their interaction with cells remain unclear. In this study, the authors focus on the acute toxicity of vapor-grown carbon fiber, HTT2800, which is one of the most highly purified multi-wall carbon nanotubes (MWCNT) by high-temperature thermal treatment. The authors exposed human bronchial epithelial cells (BEAS-2B) to HTT2800 and measured the cellular uptake, mitochondrial function, cellular LDH release, apoptotic signaling, reactive oxygen species (ROS) generation and pro-inflammatory cytokine release. The HTT2800-exposed cells showed cellular uptake of the carbon nanotube, increased cell death, enhanced DNA damage, and induced cytokine release. However, the exposed cells showed no obvious intracellular ROS generation. These cellular and molecular findings suggest that HTT2800 could cause a potentially adverse inflammatory response in BEAS-2B cells.

  18. Antimycobacterial and cytotoxicity activity of synthetic and natural compounds

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    Ana O. de Souza

    2007-01-01

    Full Text Available Antimycobacterial and cytotoxicity activity of synthetic and natural compounds. Secondary metabolites from Curvularia eragrostidis and Drechslera dematioidea, Clusia sp. floral resin, alkaloids from Pilocarpus alatus, salicylideneanilines, piperidine amides, the amine 1-cinnamylpiperazine and chiral pyridinium salts were assayed on Mycobacterium tuberculosis H37Rv. N-(salicylidene-2-hydroxyaniline was the most effective compound with a minimal inhibitory concentration (MIC of 8 µmol/L. Dihydrocurvularin was moderately effective with a MIC of 40 µmol/L. Clusia sp. floral resin and a gallocatechin-epigallocatechin mixture showed MIC of 0.02 g/L and 38 µmol/L, respectively. The cytotoxicity was evaluated for N-(salicylidene-2-hydroxyaniline, curvularin, dihydrocurvularin and Clusia sp. floral resin, and the selectivity indexes were > 125, 0.47, 0.75 and 5, respectively.

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

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    Fröhlich E

    2012-11-01

    Full Text Available Eleonore FröhlichCenter for Medical Research, Medical University of Graz, Graz, AustriaAbstract: 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.Keywords: endocytosis, plasma membrane, lysosomes, polystyrene particles, quantum dots, dendrimers

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

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    Karine Andreau

    2012-01-01

    Full Text Available 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.

  1. Natural lipids in nanostructured lipid carriers and its cytotoxicity

    Science.gov (United States)

    Lima, Paula A.; Rampazo, Caroline A. D.; Costa, Amanda F.; Rodrigues, Tiago; Watashi, Carolina M.; Durán, Nelson

    2017-06-01

    Nanostructured lipid carriers (NLCs) are active carrier systems which modulate the sustained release of actives and protect unstable compounds against degradation. NLCs can also protect skin from sun light, due to its particulates nature, which gives them intrinsic scattering properties. In this work, we present the preparation of NLCs using natural lipids and its cytotoxicity profile. It was used a vegetal butter with melting point (m.p.) ~32-40°C, an animal wax (m.p. 35-40°C) and a vegetal oil (boiling point ~120-150°C). NLCs were prepared by hot high pressure homogenization method and particles were characterized by average size (Zave), polydispersity index (PDI) and zeta potential (PZ) (Fig.1). The thermal behavior of the NLCs was studied using Differential Scanning Calorimetry (DSC). All the formulations were followed up for 60 days in order to evaluate their stability. NLCs exhibited a Zave around 150-200 nm, PDI less than 0.2 and PZ varying from -25 to -40 mV. The m.p. for the lyophilized NLCs was about 40-56°C. Cytotoxicity of the formulations were evaluated for human keratinocytes (HaCaT) and melanocytes (Melan-A) in the exponential growth phase. Cell viability was used as indicator of cytotoxicity and determined after 4 days of culture by MTT assay. It was found that the NLC formulations were not toxic against HaCaT and Melan-A cells. Results showed that the NLCs produced are potential carriers for nanocosmetics and sunscreen products.

  2. Antibody-dependent cellular cytotoxicity and cytokine/chemokine secretion by KHYG-1 cells stably expressing FcγRIIIA.

    Science.gov (United States)

    Kobayashi, Eiji; Motoi, Sotaro; Sugiura, Masahito; Kajikawa, Masunori; Kojima, Shuji; Kohroki, Junya; Masuho, Yasuhiko

    2014-09-01

    Antibody-dependent cellular cytotoxicity (ADCC) mediated by natural killer (NK) cells is a major mechanism of tumor therapy with antibodies. NK cells not only manifest cytotoxicity but also secrete a variety of cytokines/chemokines that regulate immune responses. Using a retroviral vector, in this study we established a KHYG-1 cell line that stably expresses FcγRIIIA (CD16A). The KHYG-1/FcγRIIIA cells exerted potent antibody concentration-dependent ADCC, whereas parental KHYG-1 cells did not. In contrast, without antibody, the natural killer activity of KHYG-1/FcγRIIIA cells was less potent than that of parental KHYG-1 cells. During the course of ADCC, KHYG-1/FcγRIIIA cells secreted IFN-γ and MIP-1α dependent upon antibody concentration, but parental KHYG-1 cells did not. These results suggest that KHYG-1/FcγRIIIA cells would be useful in studies to elucidate the function of NK cells and the mechanism of ADCC. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Augmentation of natural cytotoxicity by chronic low-dose ionizing radiation in murine natural killer cells primed by IL-2

    International Nuclear Information System (INIS)

    Sonn, Chung-Hee; Choi, Jong-Rip; Kim, Tae-Jin

    2012-01-01

    The possible beneficial effects of chronic low-dose irradiation (LDR) and its mechanism of action in a variety of pathophysiological processes such as cancer are a subject of intense investigation. While animal studies involving long-term exposure to LDR have yielded encouraging results, the influence of LDR at the cellular level has been less well defined. We reasoned that since natural killer (NK) cells constitute an early responder to exogenous stress, NK cells may reveal sentinel alterations in function upon exposure to LDR. When purified NK cells received LDR at 4.2 mGy/h for a total of 0.2 Gy in vitro, no significant difference in cell viability was observed. Likewise, no functional changes were detected in LDR-exposed NK cells, demonstrating that LDR alone was insufficient to generate changes at the cellular level. Nonetheless, significant augmentation of cytotoxic, but not proliferative, function was detected when NK cells were stimulated with low-dose IL-2 prior to irradiation. This enhancement of NK cytotoxicity was not due to alterations in NK-activating receptors, NK1.1, NKG2D, CD69 and 2B4, or changes in the rate of early or late apoptosis. Therefore, LDR, in the presence of suboptimal cytokine levels, can facilitate anti-tumor cytotoxicity of NK cells without influencing cellular proliferation or apoptosis. Whether these results translate to in vivo consequences remains to be seen; however, our data provide initial evidence that exposure to LDR can lead to subtle immune-enhancing effects on NK cells and may explain, in part, the functional basis underlying, diverse beneficial effects seen in the animals chronically exposed to LDR. (author)

  4. Natural Cytotoxicity Receptors: Pattern Recognition and Involvement of Carbohydrates

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    Angel Porgador

    2005-01-01

    Full Text Available Natural cytotoxicity receptors (NCRs, expressed by natural killer (NK cells, trigger NK lysis of tumor and virus-infected cells on interaction with cell-surface ligands of these target cells. We have determined that viral hemagglutinins expressed on the surface of virus-infected cells are involved in the recognition by the NCRs, NKp44 and NKp46. Recognition of tumor cells by the NCRs NKp30 and NKp46 involves heparan sulfate epitopes expressed on the tumor cell membrane. Our studies provide new evidence for the identity of the ligands for NCRs and indicate that a broader definition should be applied to pathological patterns recognized by innate immune receptors. Since nonmicrobial endogenous carbohydrate structures contribute significantly to this recognition, there is an imperative need to develop appropriate tools for the facile sequencing of carbohydrate moieties.

  5. Evaluation of the Cytotoxicity and Genotoxicity of Flavonolignans in Different Cellular Models

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    Michal Bijak

    2017-12-01

    Full Text Available Flavonolignans are the main components of silymarin, which represents 1.5–3% of the dry fruit weight of Milk thistle (Silybum marianum L. Gaernt.. In ancient Greece and Romania, physicians and herbalists used the Silybum marianum to treat a range of liver diseases. Besides their hepatoprotective action, silymarin flavonolignans have many other healthy properties, such as anti-platelet and anti-inflammatory actions. The aim of this study was to evaluate the toxic effect of flavonolignans on blood platelets, peripheral blood mononuclear cells (PBMCs and human lung cancer cell line—A549—using different molecular techniques. We established that three major flavonolignans: silybin, silychristin and silydianin, in concentrations of up to 100 µM, have neither a cytotoxic nor genotoxic effect on blood platelets, PMBCs and A549. We also saw that silybin and silychristin have a protective effect on cellular mitochondria, observed as a reduction of spontaneous mitochondrial DNA (mtDNA damage in A549, measured as mtDNA copies, and mtDNA lesions in ND1 and ND5 genes. Additionally, we observed that flavonolignans increase the blood platelets’ mitochondrial membrane potential and reduce the generation of reactive oxygen species in blood platelets. Our current findings show for the first time that the three major flavonolignans, silybin, silychristin and silydianin, do not have any cytotoxicity and genotoxicity in various cellular models, and that they actually protect cellular mitochondria. This proves that the antiplatelet and anti-inflammatory effect of these compounds is part of our molecular health mechanisms.

  6. Quantum features of natural cellular automata

    International Nuclear Information System (INIS)

    Elze, Hans-Thomas

    2016-01-01

    Cellular automata can show well known features of quantum mechanics, such as a linear rule according to which they evolve and which resembles a discretized version of the Schrödinger equation. This includes corresponding conservation laws. The class of “natural” Hamiltonian cellular automata is based exclusively on integer-valued variables and couplings and their dynamics derives from an Action Principle. They can be mapped reversibly to continuum models by applying Sampling Theory. Thus, “deformed” quantum mechanical models with a finite discreteness scale l are obtained, which for l → 0 reproduce familiar continuum results. We have recently demonstrated that such automata can form “multipartite” systems consistently with the tensor product structures of nonrelativistic many-body quantum mechanics, while interacting and maintaining the linear evolution. Consequently, the Superposition Principle fully applies for such primitive discrete deterministic automata and their composites and can produce the essential quantum effects of interference and entanglement. (paper)

  7. ZnO nanofluids for the improved cytotoxicity and cellular uptake of doxorubicin

    Directory of Open Access Journals (Sweden)

    Safoura Soleymani

    2018-01-01

    Full Text Available Objective(s: Combination anticancer therapy holds promise for improving the therapeutic efficacy of chemotherapy drugs such as doxorubicin (DOX as well as decreasing their dose-limiting side effects. Overcoming the side effects of doxorubicin (DOX is a major challenge to the effective treatment of cancer. Zinc oxide nanoparticles (ZnO NPs are emerging as potent tools for a wide variety of biomedical applications. The aim of this study was to develop a combinatorial approach for enhancing the anticancer efficacy and cellular uptake of DOX. Materials and Methods: ZnO NPs were synthesized by the solvothermal method and were characterized by X-ray diffraction (XRD, dynamic light scattering (DLS and transmission electron microscopy (TEM. ZnO NPs were dispersed in 10% bovine serum albumin (BSA and the cytotoxic effect of the resulting ZnO nanofluids was evaluated alone and in combination with DOX on DU145 cells. The influence of ZnO nanofluids on the cellular uptake of DOX and DOX-induced catalase mRNA expression were investigated by fluorescence microscopy and semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR, respectively. Results: The MTT results revealed that ZnO nanofluids decreased the cell viability of DU145 cells in a timeand dose-dependent manner. Simultaneous combination treatment of DOX and ZnO nanofluid showed a significant increase in anticancer activity and the cellular uptake of DOX compared to DOX alone. Also, a time-dependent reduction of catalase mRNA expression was observed in the cells treated with ZnO nanofluids and DOX, alone and in combination with each other. Conclusion: These results indicate the role of ZnO nanofluid as a growth-inhibitory agent and a drug delivery system for DOX in DU145 cells. Thus, ZnO nanofluid could be a candidate for combination chemotherapy.

  8. Cellular internalisation kinetics and cytotoxic properties of statistically designed and optimised neo-geometric copper nanocrystals.

    Science.gov (United States)

    Murugan, Karmani; Choonara, Yahya E; Kumar, Pradeep; du Toit, Lisa C; Pillay, Viness

    2017-09-01

    This study aimed to highlight a statistic design to precisely engineer homogenous geometric copper nanoparticles (CuNPs) for enhanced intracellular drug delivery as a function of geometrical structure. CuNPs with a dual functionality comprising geometric attributes for enhanced cell uptake and exerting cytotoxic activity on proliferating cells were synthesized as a novel drug delivery system. This paper investigated the defined concentrations of two key surfactants used in the reaction to mutually control and manipulate nano-shape and optimisation of the geometric nanosystems. A statistical experimental design comprising a full factorial model served as a refining factor to achieve homogenous geometric nanoparticles using a one-pot method for the systematic optimisation of the geometric CuNPs. Shapes of the nanoparticles were investigated to determine the result of the surfactant variation as the aim of the study and zeta potential was studied to ensure the stability of the system and establish a nanosystem of low aggregation potential. After optimisation of the nano-shapes, extensive cellular internalisation studies were conducted to elucidate the effect of geometric CuNPs on uptake rates, in addition to the vital toxicity assays to further understand the cellular effect of geometric CuNPs as a drug delivery system. In addition to geometry; volume, surface area, orientation to the cell membrane and colloidal stability is also addressed. The outcomes of the study demonstrated the success of homogenous geometric NP formation, in addition to a stable surface charge. The findings of the study can be utilized for the development of a drug delivery system for promoted cellular internalisation and effective drug delivery. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Enhancement of antibody-dependent cellular cytotoxicity of cetuximab by a chimeric protein encompassing interleukin-15.

    Science.gov (United States)

    Ochoa, Maria Carmen; Minute, Luna; López, Ascensión; Pérez-Ruiz, Elisabeth; Gomar, Celia; Vasquez, Marcos; Inoges, Susana; Etxeberria, Iñaki; Rodriguez, Inmaculada; Garasa, Saray; Mayer, Jan-Peter Andreas; Wirtz, Peter; Melero, Ignacio; Berraondo, Pedro

    2018-01-01

    Enhancement of antibody-dependent cellular cytotoxicity (ADCC) may potentiate the antitumor efficacy of tumor-targeted monoclonal antibodies. Increasing the numbers and antitumor activity of NK cells is a promising strategy to maximize the ADCC of standard-of-care tumor-targeted antibodies. For this purpose, we have preclinically tested a recombinant chimeric protein encompassing the sushi domain of the IL15Rα, IL-15, and apolipoprotein A-I (Sushi-IL15-Apo) as produced in CHO cells. The size-exclusion purified monomeric fraction of this chimeric protein was stable and retained the IL-15 and the sushi domain bioactivity as measured by CTLL-2 and Mo-7e cell proliferation and STAT5 phosphorylation in freshly isolated human NK and CD8 + T cells. On cell cultures, Sushi-IL15-Apo increases NK cell proliferation and survival as well as spontaneous and antibody-mediated cytotoxicity. Scavenger receptor class B type I (SR-B1) is the receptor for ApoA-I and is expressed on the surface of tumor cells. SR-B1 can adsorb the chimeric protein on tumor cells and can transpresent IL-15 to NK and CD8 + T cells. A transient NK-humanized murine model was developed to test the increase of ADCC attained by the chimeric protein in vivo . The EGFR + human colon cancer cell line HT-29 was intraperitoneally inoculated in immune-deficient Rag2 -/- γc -/- mice that were reconstituted with freshly isolated PBMCs and treated with the anti-EGFR mAb cetuximab. The combination of the Sushi-IL15-Apo protein and cetuximab reduced the number of remaining tumor cells in the peritoneal cavity and delayed tumor engraftment in the peritoneum. Furthermore, Sushi-IL15-Apo increased the anti-tumor effect of a murine anti-EGFR mAb in Rag1 -/- mice bearing subcutaneous MC38 colon cancer transfected to express EGFR. Thus, Sushi-IL15-Apo is a potent tool to increase the number and the activation of NK cells to promote the ADCC activity of antibodies targeting tumor antigens.

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

    Energy Technology Data Exchange (ETDEWEB)

    Geh, Stefan; Rettenmeier, Albert W.; Dopp, Elke [University Hospital, Institute of Hygiene and Occupational Medicine, Essen (Germany); Yuecel, Raif [University Hospital, Institute of Cell Biology (Cancer Research), Essen (Germany); Duffin, Rodger [Institute of Environmental Health Research (IUF), Duesseldorf (Germany); University of Edinburgh, ELEGI COLT Lab, Scotland (United Kingdom); Albrecht, Catrin; Borm, Paul J.A. [Institute of Environmental Health Research (IUF), Duesseldorf (Germany); Armbruster, Lorenz [Verein fuer Technische Sicherheit und Umweltschutz e.V., Gotha (Germany); Raulf-Heimsoth, Monika; Bruening, Thomas [Research Institute for Occupational Medicine of the Institutions for Statutory Accident Insurance and Prevention (BGFA), Bochum (Germany); Hoffmann, Eik [University of Rostock, Institute of Biology, Department of Cell Biology and Biosystems Technology, Rostock (Germany)

    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 (Oe< 10 {mu}m) 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. (orig.)

  11. Immunomodulatory Effect of Rhaphidophora korthalsii on Natural Killer Cell Cytotoxicity

    Directory of Open Access Journals (Sweden)

    Swee Keong Yeap

    2012-01-01

    Full Text Available The in vivo immunomodulatory effect of ethanolic extracts from leaves of Rhaphidophora korthalsii was determined via immune cell proliferation, T/NK cell phenotyping, and splenocyte cytotoxicity of BALB/c mice after 5 consecutive days of i.p. administration at various concentrations. Splenocyte proliferation index, cytotoxicity, peripheral blood T/NK cell population, and plasma cytokine (IL-2 and IFN-γ in mice were assessed on day 5 and day 15. High concentration of extract (350 μg/mice/day for 5 consecutive days was able to stimulate immune cell proliferation, peripheral blood NK cell population, IL-2, and IFN- γ cytokines, as well as splenocyte cytotoxicity against Yac-1 cell line. Unlike rIL-2 which degraded rapidly, the stimulatory effect from the extract managed to last until day 15. These results suggested the potential of this extract as an alternative immunostimulator, and they encourage further study on guided fractionation and purification to identify the active ingredients that contribute to this in vitro and in vivo immunomodulatory activity.

  12. Enhancement of human natural cytotoxicity by Plasmodium falciparum antigen activated lymphocytes

    DEFF Research Database (Denmark)

    Theander, T G; Pedersen, B K; Bygbjerg, I C

    1987-01-01

    Mononuclear cells (MNC) isolated from malaria immune donors and from donors never exposed to malaria were stimulated in vitro with soluble purified Plasmodium falciparum antigens (SPag) or PPD. After 7 days of culture the proliferative response and the cytotoxic activity against the natural killer...... were preincubated with interleukin 2 (IL-2) for one hour before the start of the cytotoxic assay. SPag activation did not enhance the cytotoxic activity of MNC which did not respond to the antigen in the proliferation assay, and preincubation of these cells with IL-2 did not increase the activity. PPD...

  13. Ex-vivo expanded human NK cells express activating receptors that mediate cytotoxicity of allogeneic and autologous cancer cell lines by direct recognition and antibody directed cellular cytotoxicity

    Directory of Open Access Journals (Sweden)

    Campana Dario

    2010-10-01

    Full Text Available Abstract Background The possibility that autologous NK cells could serve as an effective treatment modality for solid tumors has long been considered. However, implementation is hampered by (i the small number of NK cells in peripheral blood, (ii the difficulties associated with large-scale production of GMP compliant cytolytic NK cells, (iii the need to activate the NK cells in order to induce NK cell mediated killing and (iv the constraints imposed by autologous inhibitory receptor-ligand interactions. To address these issues, we determined (i if large numbers of NK cells could be expanded from PBMC and GMP compliant cell fractions derived by elutriation, (ii their ability to kill allogeneic and autologous tumor targets by direct cytotoxitiy and by antibody-mediated cellular cytotoxicity and (iii defined NK cell specific receptor-ligand interactions that mediate tumor target cell killing. Methods Human NK cells were expanded during 14 days. Expansion efficiency, NK receptor repertoire before and after expansion, expression of NK specific ligands, cytolytic activity against allogeneic and autologous tumor targets, with and without the addition of chimeric EGFR monoclonal antibody, were investigated. Results Cell expansion shifted the NK cell receptor repertoire towards activation and resulted in cytotoxicity against various allogeneic tumor cell lines and autologous gastric cancer cells, while sparing normal PBMC. Blocking studies confirmed that autologous cytotoxicity is established through multiple activating receptor-ligand interactions. Importantly, expanded NK cells also mediated ADCC in an autologous and allogeneic setting by antibodies that are currently being used to treat patients with select solid tumors. Conclusion These data demonstrate that large numbers of cytolytic NK cells can be generated from PBMC and lymphocyte-enriched fractions obtained by GMP compliant counter current elutriation from PBMC, establishing the preclinical

  14. Antiglycopeptide Mouse Monoclonal Antibody LpMab-21 Exerts Antitumor Activity Against Human Podoplanin Through Antibody-Dependent Cellular Cytotoxicity and Complement-Dependent Cytotoxicity.

    Science.gov (United States)

    Kato, Yukinari; Kunita, Akiko; Fukayama, Masashi; Abe, Shinji; Nishioka, Yasuhiko; Uchida, Hiroaki; Tahara, Hideaki; Yamada, Shinji; Yanaka, Miyuki; Nakamura, Takuro; Saidoh, Noriko; Yoshida, Kanae; Fujii, Yuki; Honma, Ryusuke; Takagi, Michiaki; Ogasawara, Satoshi; Murata, Takeshi; Kaneko, Mika K

    2017-02-01

    The interaction between podoplanin (PDPN) and C-type lectin-like receptor 2 (CLEC-2) is involved in tumor malignancy. We have established many monoclonal antibodies (mAbs) against human podoplanin using the cancer-specific mAb (CasMab) technology. LpMab-21, one of the mouse antipodoplanin mAbs, is of the IgG 2a subclass, and its minimum epitope was determined to be Thr76-Arg79 of the human podoplanin. Importantly, sialic acid is linked to Thr76; therefore, LpMab-21 is an antiglycopeptide mAb (GpMab). In this study, we investigated whether LpMab-21 shows antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) against human podoplanin-expressing cancer cell lines in vitro and also studied its antitumor activities using a xenograft model. LpMab-21 showed high ADCC and CDC activities against not only podoplanin-expressing Chinese hamster ovary cells but also LN319 glioblastoma cells and PC-10 lung cancer cells, both of which endogenously express podoplanin. Furthermore, LpMab-21 decreased tumor growth in vivo, indicating that LpMab-21 could be useful for antibody therapy against human podoplanin-expressing cancers.

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

    Science.gov (United States)

    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.

  16. Rapid kinetics of lysis in human natural cell-mediated cytotoxicity: some implications

    International Nuclear Information System (INIS)

    Bloom, E.T.; Babbitt, J.T.

    1983-01-01

    The entire lytic process of natural cell-mediated cytotoxicity against sensitive target cells can occur rapidly, within minutes. This was demonstrated by 51 chromium release and in single-cell assays. At the cellular level, most of the target cell lysis occurred within 15-30 min after binding to effector cells. The enriched natural killer cell subpopulation of lymphocytes obtained by Percoll density gradient centrifugation (containing greater than 70% large granular lymphocytes (LGL)) was the most rapidly lytic population by 51 chromium release. However, in the single-cell assay, the rate of lysis of bound target cells was quite similar for the LGL-enriched effector subpopulation and the higher density subpopulation of effector cells recognized previously. Both the light and dense effector cells contained similar numbers of target binding cells. Therefore, that the light subpopulation effected lysis more rapidly and to a greater extent than the dense subpopulation suggested that the low-density effector cells probably recycled more rapidly than those of higher density. This was corroborated by the finding that when conjugates were formed at 29 degrees C for the single-cell assay, a significant number of dead unconjugated targets could be observed only on the slides made with the LGL-enriched effector cells but not on those made with dense effector cell. Lysis continued to increase in the chromium-release assay probably because of recycling, recruitment, and/or heterogeneity of the effector cells, and/or because of heterogeneity or delayed death of the target cells

  17. Cellular pharmacodynamics of the cytotoxic guanidino-containing drug CHS 828. Comparison with methylglyoxal-bis(guanylhydrazone).

    Science.gov (United States)

    Ekelund, S; Sjöholm, A; Nygren, P; Binderup, L; Larsson, R

    2001-04-20

    N-(6-(4-chlorophenoxy)hexyl)-N'-cyano-N"-4-pyridylguanidine (CHS 828) is a new guanidino-containing compound with antitumoral activity both in vitro and in vivo. Its activity profile differs from those of standard cytotoxic drugs but the mechanism of action is not yet fully understood. CHS 828 is presently in early phase I and II clinical trials. In the present study, the pharmacodynamic effects at the cellular level of CHS 828 was compared to another compound containing two guanidino groups, methylglyoxal-bis(guanylhydrazone) (MGBG). MGBG is known to inhibit the synthesis of polyamines, which are important in, e.g., proliferation and macromolecular synthesis. The concentration-response relationship of CHS 828 closely resembled that of MGBG and the drugs were similar with respect to inhibition of DNA and protein synthesis. On the other hand, CHS 828 induced a significant increase in cellular metabolism while MGBG did not. The cytotoxic effect of MGBG was reversed by the addition of exogenous polyamines, while that of CHS 828 was unaffected. Unlike MGBG, there was also no effect of CHS 828 on the levels of decarboxylating enzymes in the polyamine biosynthesis. In conclusion, CHS 828 does not appear to share any major mechanisms of action with the polyamine synthesis inhibitor MGBG. Further studies will be required to define the exact mechanism of action of CHS 828.

  18. Natural agents: cellular and molecular mechanisms of photoprotection.

    Science.gov (United States)

    Afaq, Farrukh

    2011-04-15

    The skin is the largest organ of the body that produces a flexible and self-repairing barrier and protects the body from most common potentially harmful physical, environmental, and biological insults. Solar ultraviolet (UV) radiation is one of the major environmental insults to the skin and causes multi-tiered cellular and molecular events eventually leading to skin cancer. The past decade has seen a surge in the incidence of skin cancer due to changes in life style patterns that have led to a significant increase in the amount of UV radiation that people receive. Reducing excessive exposure to UV radiation is desirable; nevertheless this approach is not easy to implement. Therefore, there is an urgent need to develop novel strategies to reduce the adverse biological effects of UV radiation on the skin. A wide variety of natural agents have been reported to possess substantial skin photoprotective effects. Numerous preclinical and clinical studies have elucidated that natural agents act by several cellular and molecular mechanisms to delay or prevent skin cancer. In this review article, we have summarized and discussed some of the selected natural agents for skin photoprotection. Copyright © 2010 Elsevier Inc. All rights reserved.

  19. Cellular and humoral immunity after vaccination or natural mumps infection.

    Science.gov (United States)

    Terada, Kihei; Hagihara, Kimiko; Oishi, Tomohiro; Miyata, Ippei; Akaike, Hiroto; Ogita, Satoko; Ohno, Naoki; Ouchi, Kazunobu

    2017-08-01

    This study measured cell-mediated immunity (CMI) and serum antibody to clarify the basis of breakthrough after vaccination and reinfection after mumps. From a pool of 54 college students, 17 seronegative subjects and 14 subjects with intermediate level of antibodies against mumps were vaccinated with a monovalent mumps vaccine, and CMI was assessed using interferon-γ release assay. CMI positivity according to pre-existing antibody level, defined as titer  0.05), respectively. Vaccination or even natural mumps infection did not always induce both cellular and humoral immunity. © 2017 Japan Pediatric Society.

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

    Digital Repository Service at National Institute of Oceanography (India)

    Augustine, M.S.; Anas, A.; Das, A.V.; Sreekanth, S.; Jayalekshmi, S.

    into solution and by generating free radical species. In animal experiments, QDs preferentially enter the liver and spleen follow-ing intravascular injection which undergo minimal excretion if lar-ger than 6 nm, and appear to be safe to the animal. The present... recently on toxicity studies of quantum dots (QDs) in cells and animals [49,50]. Cell culture experiments have shown that QDs undergo design- dependent intracellular localiza-tion which can cause cytotoxicity by releasing free toxic materials...

  1. Biocompatibility index of antiseptic agents by parallel assessment of antimicrobial activity and cellular cytotoxicity.

    Science.gov (United States)

    Müller, Gerald; Kramer, Axel

    2008-06-01

    To assess the suitability of an antiseptic agent, both the microbicidal activity and the cytotoxic effect must be taken into consideration to derive biocompatible antibacterial agents. We defined the biocompatibility index (BI) by measuring the antibacterial activity against the test organisms Escherichia coli and Staphylococcus aureus and, in parallel, the cytotoxicity on cultured murine fibroblasts. The antiseptic agents tested were benzalkonium chloride (BAC), cetylpyridinium chloride (CPC), chlorhexidine digluconate (CHX), mild silver protein (MSP), octenidine dihydrochloride (OCT), polyhexamethylene biguanide (PHMB), povidone iodine in solution [PVP-I(s)], povidone iodine in ointment [PVP-I(o)], silver nitrate (AgNO(3)), silver (I) sulfadiazine (SSD) and triclosan (TRI). Assays were carried out for 30 min of exposure at 37 degrees C in the presence of cell culture medium containing 10% fetal bovine serum. The resulting dimensionless BI was defined as the ratio of the concentration at which 50% of the murine fibroblasts are damaged and the microbicidal effect producing at least 3 log(10) (99.9%) reduction. The resulting rank ordering of BI for the ratio of fibroblast cytotoxicity to E. coli toxicity was OCT > PHMB > CHX > PVP-I(o) > PVP-I(s) > BAC > CPC > TRI > MSP and that to S. aureus was OCT > PHMB > CHX > CPC > PVP-I(o) > BAC > PVP(s) > TRI > MSP. OCT and PHMB were the most suitable agents with a BI greater than 1. The BI presented may be a useful tool to evaluate antiseptic agents for use in clinical practice.

  2. Suppression of natural killer cell cytotoxicity in postpartum women: time course and potential mechanisms.

    Science.gov (United States)

    Groer, Maureen W; El-Badri, Nagwa; Djeu, Julie; Williams, S Nicole; Kane, Bradley; Szekeres, Karoly

    2014-07-01

    Little is known about the recovery of the immune system from normal pregnancy and whether the postpartum period is a uniquely adapted immune state. This report extends previous observations from our group of decreased natural killer (NK) cell cytotoxicity in the postpartum period. NK cytotoxicity was measured from 1 week through 9 months postpartum. In addition, NK cytotoxicity was assayed in the presence or absence of pooled plasmas collected from either postpartum or nonpostpartum women. Samples of cells were stained for inhibitory receptors and analyzed by flow cytometry. NK cytotoxicity remained decreased in postpartum women compared to controls through the first 6 postpartum months, returned to normal levels by 9 months, and remained normal at 12 months. NK cytotoxicity during the first 6 months was further inhibited by the addition of pooled plasma to NK cultures from postpartum women, but the addition of pooled plasma from the control group did not affect that group's NK cultures. There were differences in inhibitory receptor staining between the two groups, with decreased CD158a and CD158b and increased NKG2A expression on postpartum NK cells during the first 3 postpartum months. These data suggest that NK cytotoxicity postpartum inhibition lasts 6 months and is influenced by unidentified postpartum plasma components. The effect may also involve receptors on NK cells. © The Author(s) 2013.

  3. KHYG-1, a model for the study of enhanced natural killer cell cytotoxicity.

    Science.gov (United States)

    Suck, Garnet; Branch, Donald R; Smyth, Mark J; Miller, Richard G; Vergidis, Joanna; Fahim, Soad; Keating, Armand

    2005-10-01

    To compare the cytotoxicity of KHYG-1 with other natural killer (NK)/NK T-cell lines and identify molecules that may be associated with enhanced cytotoxicity, thereby eventually leading to improved NK cell-mediated cancer immunotherapy. NK/NK T-cell lines KHYG-1, NK-92, YT, and SNT-8 were compared with a novel flow cytometric cytotoxicity assay under different culture conditions. Transcription, expression, and phosphorylation studies were performed using polymerase chain reaction sequence-specific primers, reverse transcription polymerase chain reaction, immunoblotting, and flow cytometry. KHYG-1 is a highly cytotoxic cell line, exceeding the cytolytic capacity of the other cell lines against K562. KHYG-1 is also highly cytotoxic against the leukemia cell lines EM2, EM3, and HL60. The novel activation receptor NKp44 and its adaptor, DAP12, NKG2D, and constitutively phosphorylated ERK2 may be associated with the enhanced cytotoxicity of KHYG-1. This cell line most likely mediates cytolysis by granzyme M (but not granzymes A and B) together with perforin, which is constitutively fully cleaved to the 60-kD form, in contrast to the other cell lines. KHYG-1 is a valuable model for the study of enhanced cytotoxicity by NK cells. In addition to the activation of NKp44, KHYG-1 may induce apoptosis of tumor cells by the newly described granzyme M/perforin pathway. Targeted modifications of effector molecules demonstrated in this model could generate NK cells with even greater killing ability that may be particularly attractive for clinical application. Moreover, our demonstration of greater cytotoxicity of KHYG-1 versus NK-92 cells, already in clinical trials, suggests a direct therapeutic role for KHYG-1.

  4. A rapid fluorometric method for semiautomated determination of cytotoxicity and cellular proliferation of human tumor cell lines in microculture.

    Science.gov (United States)

    Larsson, R; Nygren, P

    1989-01-01

    A fluorometric method for the determination of cellular growth and cytotoxicity of human tumor cell lines in 96-well microculture plates is described. The assay is based on the combined use of the DNA-binding dye Hoechst 33342 and the fluorogenic substrate fluorescein diacetate (FDA). Hoechst 33342 undergoes a dramatic enhancement of fluorescence when specifically intercalated with cellular DNA, whereas the FDA fluorescence is dependent on cellular hydrolysis of the non-fluorescent substrate into its fluorescent product. Fluorescence from both dyes was linearly related to the density of freshly seeded cells (6 x 10(3)-1 x 10(5)/well) and correlated well with physical cell count of cells under normal culture conditions as well as in response to the vinca alkaloid vincristine. However, the amount of FDA fluorescence produces and retained by the cultures was clearly dependent on the fraction of intact and viable cells, whereas the fluorescence reported by Hoechst 33342 was not. The assay was found to be simple, reliable and many samples could be analysed in a short period of time with minimal waste of cells and biological reagents. Apart from giving an estimate of cell density, the protocol described also provides a separate index of viability which in certain situations may be of importance for distinguishing between cytocidal and cytostatic drug actions. The method may be well suited for several applications, including the large scale screening for antitumor activity of compounds with potential cytocidal or cytostatic actions.

  5. Synthesis, cytotoxicity, cellular uptake and influence on eicosanoid metabolism of cobalt-alkyne modified fructoses in comparison to auranofin and the cytotoxic COX inhibitor Co-ASS.

    Science.gov (United States)

    Ott, Ingo; Koch, Thao; Shorafa, Hashem; Bai, Zhenlin; Poeckel, Daniel; Steinhilber, Dieter; Gust, Ronald

    2005-06-21

    Propargylhexacarbonyldicobalt complexes with fructopyranose ligands were prepared and investigated for cytotoxicity in the MCF-7 human breast cancer cell line. The antiproliferative effects depended on the presence of isopropylidene protecting groups in the carbohydrate ligand and correlated with the cellular concentration of the complexes. IC(50) values of > 20 microM demonstrated that the fructose derivatives were only moderately active compared to the references auranofin and the aspirin (ASS) derivative [2-acetoxy(2-propynyl)benzoate]hexacarbonyldicobalt (Co-ASS). In continuation of our studies on the mode of action of cobalt-alkyne complexes we studied the influence of the compounds on the formation of 12-HHT (COX-1 product) and 12-HETE (12-LOX product) by human platelets as an indication of the interference in the eicosanoid metabolism, which is discussed as a target system of cytostatics. Co-ASS was an efficient COX-1 inhibitor without LOX inhibitory activity and auranofin inhibited both COX-1 and 12-LOX eicosanoid production. The missing activity of the fructopyranose complexes at the 12-LOX and the only moderate effects at COX-1 indicate that COX/LOX inhibition may be in part responsible for the pharmacological effects of auranofin and Co-ASS but not for those of the fructopyranose complexes.

  6. Reduced antibody-dependent cellular cytotoxicity to herpes simplex virus-infected cells of salivary polymorphonuclear leukocytes and inhibition of peripheral blood polymorphonuclear leukocyte cytotoxicity by saliva.

    Science.gov (United States)

    Ashkenazi, M; Kohl, S

    1990-06-15

    Blood polymorphonuclear leukocytes (BPMN) have been shown to mediate antibody-dependent cellular cytotoxicity (ADCC) against HSV-infected cells. Although HSV infections are frequently found in the oral cavity, the ADCC capacity of salivary PMN (SPMN) has not been studied, mainly because methods to isolate SPMN were not available. We have recently developed a method to isolate SPMN, and in this study have evaluated their ADCC activity against HSV-infected cells. SPMN were obtained by repeated washings of the oral cavity, and separated from epithelial cells by nylon mesh filtration. ADCC was quantitatively determined by 51Cr release from HSV-infected Chang liver cells. SPMN in the presence of antibody were able to destroy HSV-infected cells, but SPMN were much less effective in mediating ADCC than BPMN (3.4% vs 40.7%, p less than 0.0001). In the presence of antiviral antibody, SPMN were able to adhere to HSV-infected cells, but less so than BPMN (34% vs 67%), and specific antibody-induced adherence was significantly lower in SPMN (p less than 0.04). The spontaneous adherence to HSV-infected cells was higher for SPMN than BPMN. SPMN demonstrated up-regulation of the adhesion glycoprotein CD18, but down-regulation of the FcRIII receptor. Incubation with saliva decreased ADCC capacity of BPMN, up-regulated CD18 expression, and down-regulated FcRIII expression.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    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 α 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 3 H-plenolin, no radioactive drug and/or metabolite was sequestered in the organs of BDF 1 mice. Approximately 50% of 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

  9. Natural mineral particles are cytotoxic to rainbow trout gill epithelial cells in vitro.

    Directory of Open Access Journals (Sweden)

    Christian Michel

    Full Text Available Worldwide increases in fluvial fine sediment are a threat to aquatic animal health. Fluvial fine sediment is always a mixture of particles whose mineralogical composition differs depending on the sediment source and catchment area geology. Nonetheless, whether particle impact in aquatic organisms differs between mineral species remains to be investigated. This study applied an in vitro approach to evaluate cytotoxicity and uptake of four common fluvial mineral particles (quartz, feldspar, mica, and kaolin; concentrations: 10, 50, 250 mg L(-1 in the rainbow trout epithelial gill cell line RTgill-W1. Cells were exposed for 24, 48, 72, and 96 h. Cytotoxicity assays for cell membrane integrity (propidium iodide assay, oxidative stress (H2DCF-DA assay, and metabolic activity (MTT assay were applied. These assays were complemented with cell counts and transmission electron microscopy. Regardless of mineral species, particles ≤ 2 µm in diameter were taken up by the cells, suggesting that particles of all mineral species came into contact and interacted with the cells. Not all particles, however, caused strong cytotoxicity: Among all assays the tectosilicates quartz and feldspar caused sporadic maximum changes of 0.8-1.2-fold compared to controls. In contrast, cytotoxicity of the clay particles was distinctly stronger and even differed between the two particle types: mica induced concentration-dependent increases in free radicals, with consistent 1.6-1.8-fold-changes at the 250 mg L(-1 concentration, and a dilated endoplasmic reticulum. Kaolin caused concentration-dependent increases in cell membrane damage, with consistent 1.3-1.6-fold increases at the 250 mg L(-1 concentration. All effects occurred in the presence or absence of 10% fetal bovine serum. Cell numbers per se were marginally affected. Results indicate that (i. natural mineral particles can be cytotoxic to gill epithelial cells, (ii. their cytotoxic potential differs between mineral

  10. Biocompatibility of a fish scale-derived artificial cornea: Cytotoxicity, cellular adhesion and phenotype, and in vivo immunogenicity.

    Science.gov (United States)

    van Essen, T H; van Zijl, L; Possemiers, T; Mulder, A A; Zwart, S J; Chou, C-H; Lin, C C; Lai, H J; Luyten, G P M; Tassignon, M J; Zakaria, N; El Ghalbzouri, A; Jager, M J

    2016-03-01

    To determine whether a fish scale-derived collagen matrix (FSCM) meets the basic criteria to serve as an artificial cornea, as determined with in vitro and in vivo tests. Primary corneal epithelial and stromal cells were obtained from human donor corneas and used to examine the (in)direct cytotoxicity effects of the scaffold. Cytotoxicity was assessed by an MTT assay, while cellular proliferation, corneal cell phenotype and adhesion markers were assessed using an EdU-assay and immunofluorescence. For in vivo-testing, FSCMs were implanted subcutaneously in rats. Ologen(®) Collagen Matrices were used as controls. A second implant was implanted as an immunological challenge. The FSCM was implanted in a corneal pocket of seven New Zealand White rabbits, and compared to sham surgery. The FSCM was used as a scaffold to grow corneal epithelial and stromal cells, and displayed no cytotoxicity to these cells. Corneal epithelial cells displayed their normal phenotypical markers (CK3/12 and E-cadherin), as well as cell-matrix adhesion molecules: integrin-α6 and β4, laminin 332, and hemi-desmosomes. Corneal stromal cells similarly expressed adhesion molecules (integrin-α6 and β1). A subcutaneous implant of the FSCM in rats did not induce inflammation or sensitization; the response was comparable to the response against the Ologen(®) Collagen Matrix. Implantation of the FSCM in a corneal stromal pocket in rabbits led to a transparent cornea, healthy epithelium, and, on histology, hardly any infiltrating immune cells. The FSCM allows excellent cell growth, is not immunogenic and is well-tolerated in the cornea, and thus meets the basic criteria to serve as a scaffold to reconstitute the cornea. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Hoskins Clare

    2012-04-01

    Full Text Available Abstract 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

  12. In vitro cytotoxicity and genotoxicity of composite mixtures of natural rubber and leather residues used for textile applications.

    Science.gov (United States)

    Cavalcante, Dalita Gsm; Gomes, Andressa S; Dos Reis, Elton Ap; Danna, Caroline S; Kerche-Silva, Leandra E; Yoshihara, Eidi; Job, Aldo E

    2017-06-01

    A novel composite material has been developed from natural rubber and leather waste, and a corresponding patent has been filed. This new material may be incorporated into textile and footwear products. However, as leather waste contains chromium, the biocompatibility of this new material and its safety for use in humans must be investigated. The aim of the present study was to investigate the presence of chromium in this new material, determine the amount of each form of chromium present (trivalent or hexavalent), and evaluate the potential cytotoxic and genotoxic effects of the novel composite in two cell lines. The cellular viability was quantified using the MTT3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction method and neutral red uptake assay, and genotoxic damage was analyzed using the comet assay. Our findings indicated that the extracts obtained from the composite were severely cytotoxic to both cell lines tested, and additionally highly genotoxic to MRC-5 cells. These biological responses do not appear to be attributable to the presence of chromium, as the trivalent form was predominantly found to be present in the extracts, indicating that hexavalent chromium is not formed during the production of the novel composite. The incorporation of this new material in applications that do not involve direct contact with the human skin is thus indicated, and it is suggested that the chain of production of this material be studied in order to improve its biocompatibility so that it may safely be used in the textile and footwear industries.

  13. A cellular uptake and cytotoxicity properties study of gallic acid-loaded mesoporous silica nanoparticles on Caco-2 cells

    Science.gov (United States)

    Rashidi, Ladan; Vasheghani-Farahani, Ebrahim; Soleimani, Masoud; Atashi, Amir; Rostami, Khosrow; Gangi, Fariba; Fallahpour, Masoud; Tahouri, Mohammad Taher

    2014-03-01

    In this study, the effects of intracellular delivery of various concentrations of gallic acid (GA) as a semistable antioxidant, gallic acid-loaded mesoporous silica nanoparticles (MSNs-GA), and cellular uptake of nanoparticles into Caco-2 cells were investigated. MSNs were synthesized and loaded with GA, then characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy, N2 adsorption isotherms, X-ray diffraction, and thermal gravimetric analysis. The cytotoxicity of MSNs and MSNs-GA at low and high concentrations were studied by means of 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) test and flow cytometry. MSNs did not show significant toxicity in various concentrations (0-500 μg/ml) on Caco-2 cells. For MSNs-GA, cell viability was reduced as a function of incubation time and different concentrations of nanoparticles. The in vitro GA release from MSNs-GA exhibited the same antitumor properties as free GA on Caco-2 cells. Flow cytometry results confirmed those obtained using MTT assay. TEM and fluorescent microscopy confirmed the internalization of MSNs by Caco-2 cells through nonspecific cellular uptake. MSNs can easily internalize into Caco-2 cells without deleterious effects on cell viability. The cell viability of Caco-2 cells was affected during MSNs-GA uptake. MSNs could be designed as suitable nanocarriers for antioxidants delivery.

  14. Paucity of natural killer and cytotoxic T cells in human neuromyelitis optica lesions

    Science.gov (United States)

    Saadoun, Samira; Bridges, Leslie R.; Verkman, A. S.; Papadopoulos, Marios C.

    2013-01-01

    Neuromyelitis optica is a severe inflammatory demyelinating disease of the central nervous system. Most patients with neuromyelitis optica have circulating immunoglobulin G (IgG) antibodies against the astrocytic water channel protein aquaporin-4 (AQP4), which are pathogenic. Anti-AQP4 IgG-mediated complement-dependent astrocyte toxicity is a key mechanism of central nervous system damage in neuromyelitis optica, but the role of natural killer and cytotoxic T cells is unknown. Our objective was to determine whether natural killer and cytotoxic T cells play a role in human neuromyelitis optica lesions. We immunostained four actively demyelinating lesions, obtained from patients with anti-AQP4 IgG positive neuromyelitis optica, for Granzyme B and Perforin. The inflammatory cells were perivascular neutrophils, eosinophils and macrophages, with only occasional Granzyme B+ or Perforin + cells. Greater than 95% of inflamed vessels in each lesion had no surrounding Granzyme B+ or Perforin + cells. Granzyme B+ or Perforin+ cells were abundant in human spleen (positive control). Although natural killer cells produce central nervous system damage in mice injected with anti-AQP4 IgG, our findings here indicate that natural killer-mediated and T cell-mediated cytotoxicity are probably not involved in central nervous system damage in human neuromyelitis optica. PMID:23108041

  15. In-vitro cytotoxicity and cellular uptake studies of luminescent functionalized core-shell nanospheres

    Directory of Open Access Journals (Sweden)

    Anees A. Ansari

    2017-09-01

    Full Text Available Monodispersed luminescent functionalized core-shell nanospheres (LFCSNs were successfully synthesized and investigated for their cyto-toxic effect on human liver hepatocellular carcinoma cell line (HepG2 cells by adopting MTT, DNA Ladder, TUNEL assay and qPCR based gene expressions through mRNA quantifications. The TUNEL and DNA ladder assays suggested an insignificant apoptosis in HepG2 cells due to the LFCSNs treatment. Further, the qPCR results also show that the mRNA expressions of cell cycle checkpoint gene p53 and apoptosis related gene (caspase-9 was up-regulated, while the antiapoptotic gene BCl-2 and apoptosis related genes FADD and CAS-3 (apoptosis effecter gene were down-regulated in the LFCSNs treated cells. The nanospheres that were loaded into the cells confirm their intracellular uptake by light and fluorescent spectro-photometry and microscopy imaging analysis. The loaded nanospheres demonstrate an absolute resistance to photo-bleaching, which were applied for dynamic imaging to real-time tracking in-vitro cell migratory activity for continuous 24 and 48 h durations using a time-lapsed fluorescent microscope. These properties of LFCSNs could therefore promote applications in the area of fluorescent protein biolabeling and drug-delivery.

  16. Lactic Acid Bacteria from Kefir Increase Cytotoxicity of Natural Killer Cells to Tumor Cells.

    Science.gov (United States)

    Yamane, Takuya; Sakamoto, Tatsuji; Nakagaki, Takenori; Nakano, Yoshihisa

    2018-03-27

    The Japanese fermented beverage, homemade kefir, contains six lactic acid bacteria: Lactococcus. lactis subsp. Lactis , Lactococcus . lactis subsp. Cremoris , Lactococcus. Lactis subsp. Lactis biovar diacetylactis , Lactobacillus plantarum , Leuconostoc meseuteroides subsp. Cremoris and Lactobacillus casei . In this study, we found that a mixture of the six lactic acid bacteria from kefir increased the cytotoxicity of human natural killer KHYG-1 cells to human chronic myelogenous leukemia K562 cells and colorectal tumor HCT116 cells. Furthermore, levels of mRNA expression and secretion of IFN-γ (interferon gamma) increased in KHYG-1 cells that had been treated with the six lactic acid bacteria mixture from kefir. The results suggest that the six lactic acid bacteria mixture from kefir has strong effects on natural immunity and tumor cell cytotoxicity.

  17. Lactic Acid Bacteria from Kefir Increase Cytotoxicity of Natural Killer Cells to Tumor Cells

    Directory of Open Access Journals (Sweden)

    Takuya Yamane

    2018-03-01

    Full Text Available The Japanese fermented beverage, homemade kefir, contains six lactic acid bacteria: Lactococcus. lactis subsp. Lactis, Lactococcus. lactis subsp. Cremoris, Lactococcus. Lactis subsp. Lactis biovar diacetylactis, Lactobacillus plantarum, Leuconostoc meseuteroides subsp. Cremoris and Lactobacillus casei. In this study, we found that a mixture of the six lactic acid bacteria from kefir increased the cytotoxicity of human natural killer KHYG-1 cells to human chronic myelogenous leukemia K562 cells and colorectal tumor HCT116 cells. Furthermore, levels of mRNA expression and secretion of IFN-γ (interferon gamma increased in KHYG-1 cells that had been treated with the six lactic acid bacteria mixture from kefir. The results suggest that the six lactic acid bacteria mixture from kefir has strong effects on natural immunity and tumor cell cytotoxicity.

  18. Immunization with Clinical HIV-1 Env Proteins Induces Broad Antibody Dependent Cellular Cytotoxicity-Mediating Antibodies in a Rabbit Vaccination Model

    DEFF Research Database (Denmark)

    Karlsson, Ingrid; Borggren, Marie; Jensen, Sanne Skov

    2018-01-01

    The induction of both neutralizing antibodies and non-neutralizing antibodies with effector functions, for example, antibody-dependent cellular cytotoxicity (ADCC), is desired in the search for effective vaccines against HIV-1. In the pursuit of novel immunogens capable of inducing an efficient a...

  19. Lactic Acid Bacteria from Kefir Increase Cytotoxicity of Natural Killer Cells to Tumor Cells

    OpenAIRE

    Takuya Yamane; Tatsuji Sakamoto; Takenori Nakagaki; Yoshihisa Nakano

    2018-01-01

    The Japanese fermented beverage, homemade kefir, contains six lactic acid bacteria: Lactococcus. lactis subsp. Lactis, Lactococcus. lactis subsp. Cremoris, Lactococcus. Lactis subsp. Lactis biovar diacetylactis, Lactobacillus plantarum, Leuconostoc meseuteroides subsp. Cremoris and Lactobacillus casei. In this study, we found that a mixture of the six lactic acid bacteria from kefir increased the cytotoxicity of human natural killer KHYG-1 cells to human chronic myelogenous leukemia K562 cell...

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

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Xinhui [State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237 (China); Liang, Tong [Engineering Research Center for Biomedical Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China); Liu, Changsheng [State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237 (China); Engineering Research Center for Biomedical Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China); Yuan, Yuan, E-mail: yyuan@ecust.edu.cn [Engineering Research Center for Biomedical Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China); Qian, Jiangchao, E-mail: jiangchaoqian@ecust.edu.cn [State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237 (China)

    2016-10-01

    Three types of hydroxyapatite nanoparticles (HAPNs) were synthesized employing a sonochemistry-assisted microwave method by changing microwave power (from 200 to 300 W) or using calcination treatment: L200 (200 W, lyophilization), L300 (300 W, lyophilization) and C200 (200 W, 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. - Highlights: • Three types of HAPNs (L200, L300 and C200) were synthesized employing a sonochemistry-assisted microwave method. • L200 exhibited the greatest cytotoxicity to human gastric cancer (MGC80-3) cells. • L200 showed a smaller size and higher specific surface area. • The L200 nanoparticles were more efficiently uptaken by MGC80-3 cells through energy-dependent pathways. • L200 caused the most significant increase in the intracellular calcium level.

  1. Association of Angiotensin-Converting Enzyme (ACE Gene Polymorphism with Inflammation and Cellular Cytotoxicity in Vitiligo Patients.

    Directory of Open Access Journals (Sweden)

    Laila Rashed

    Full Text Available Vitiligo is a disorder with profound heterogeneity in its aetio-pathophysiology. Angiotensin converting enzyme (ACE plays an important role in the physiology of the vasculature, blood pressure and inflammation. An insertion/deletion (I/D polymorphism of the ACE gene was reported be associated with the development of vitiligo.Our aim was to evaluate the ACE I/D polymorphism in vitiligo patients and controls. Our second aim was to find a possible association between ACE gene polymorphism and inflammatory mediators (as interleukin (IL-6 and/or cellular cytotoxicity induced by serum nitrite (as a breakdown product of the cytotoxic nitric oxide in vitiligo patients.This case-control study included 74 vitiligo patients and 75 apparently healthy controls. The distribution of ACE gene I/D genotype was investigated using PCR. Serum ACE, IL-6 and nitrite were measured by colorimetric method, ELISA and Griess assay respectively.The ACE allele frequency was significantly different between vitiligo patients and healthy controls (P = 0.026. However there was no significant difference between the ACE genotyping frequency in both groups (P = 0.115. There were statistically significant higher VIDA score (P = 0.007, and serum IL-6 (P < 0.001 in patients with the DD genotype when compared to other genotypes. Serum nitrite in patients with the DD genotype was significantly higher (P = 0.007 when compared to patients with II genotype. Serum levels of ACE, IL-6 and nitrite in vitiligo patients were statistically significantly higher than those in controls.As a conclusion, ACE gene polymorphism might grant susceptibility to develop vitiligo. Serum IL-6 and nitrite levels might have an important role in the pathogenesis of vitiligo. Targeting these two factors might have an implication in the treatment of some resistant cases.

  2. Association of Angiotensin-Converting Enzyme (ACE) Gene Polymorphism with Inflammation and Cellular Cytotoxicity in Vitiligo Patients.

    Science.gov (United States)

    Rashed, Laila; Abdel Hay, Rania; Mahmoud, Rania; Hasan, Nermeen; Zahra, Amr; Fayez, Salwa

    2015-01-01

    Vitiligo is a disorder with profound heterogeneity in its aetio-pathophysiology. Angiotensin converting enzyme (ACE) plays an important role in the physiology of the vasculature, blood pressure and inflammation. An insertion/deletion (I/D) polymorphism of the ACE gene was reported be associated with the development of vitiligo. Our aim was to evaluate the ACE I/D polymorphism in vitiligo patients and controls. Our second aim was to find a possible association between ACE gene polymorphism and inflammatory mediators (as interleukin (IL)-6) and/or cellular cytotoxicity induced by serum nitrite (as a breakdown product of the cytotoxic nitric oxide) in vitiligo patients. This case-control study included 74 vitiligo patients and 75 apparently healthy controls. The distribution of ACE gene I/D genotype was investigated using PCR. Serum ACE, IL-6 and nitrite were measured by colorimetric method, ELISA and Griess assay respectively. The ACE allele frequency was significantly different between vitiligo patients and healthy controls (P = 0.026). However there was no significant difference between the ACE genotyping frequency in both groups (P = 0.115). There were statistically significant higher VIDA score (P = 0.007), and serum IL-6 (P ACE, IL-6 and nitrite in vitiligo patients were statistically significantly higher than those in controls. As a conclusion, ACE gene polymorphism might grant susceptibility to develop vitiligo. Serum IL-6 and nitrite levels might have an important role in the pathogenesis of vitiligo. Targeting these two factors might have an implication in the treatment of some resistant cases.

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

    International Nuclear Information System (INIS)

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

    2011-01-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Parab, Harshala J; Huang, Jing-Hong; Liu, Ru-Shi [Department of Chemistry, National Taiwan University, Taipei 106, Taiwan (China); Lai, Tsung-Ching; Jan, Yi-Hua; Wang, Jui-Ling; Hsiao, Michael; Chen, Chung-Hsuan [Genomics Research Center, Academia Sinica, Taipei 115, Taiwan (China); Hwu, Yeu-Kuang [Institute of Physics, Academia Sinica, Taipei 115, Taiwan (China); Tsai, Din Ping [Department of Physics, National Taiwan University, Taipei 106, Taiwan (China); Chuang, Shih-Yi; Pang, Jong-Hwei S, E-mail: rsliu@ntu.edu.tw, E-mail: mhsiao@gate.sinica.edu.tw [Graduate Institute of Clinical Medical Sciences, Chang Gung University, Tao-Yuan, Taiwan (China)

    2011-09-30

    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.

  5. Cytotoxicity and cellular uptake of different sized gold nanoparticles in ovarian cancer cells

    Science.gov (United States)

    Kumar, Dhiraj; Mutreja, Isha; Chitcholtan, Kenny; Sykes, Peter

    2017-11-01

    Nanomedicine has advanced the biomedical field with the availability of multifunctional nanoparticles (NPs) systems that can target a disease site enabling drug delivery and helping to monitor the disease. In this paper, we synthesised the gold nanoparticles (AuNPs) with an average size 18, 40, 60 and 80 nm, and studied the effect of nanoparticles size, concentration and incubation time on ovarian cancer cells namely, OVCAR5, OVCAR8, and SKOV3. The size measured by transmission electron microscopy images was slightly smaller than the hydrodynamic diameter; measured size by ImageJ as 14.55, 38.13, 56.88 and 78.56 nm. The cellular uptake was significantly controlled by the AuNPs size, concentration, and the cell type. The nanoparticles uptake increased with increasing concentration, and 18 and 80 nm AuNPs showed higher uptake ranging from 1.3 to 5.4 μg depending upon the concentration and cell type. The AuNPs were associated with a temporary reduction in metabolic activity, but metabolic activity remained more than 60% for all sample types; NPs significantly affected the cell proliferation activity in first 12 h. The increase in nanoparticle size and concentration induced the production of reactive oxygen species in 24 h.

  6. Study on the cytotoxicity of natural killer cells induced by endothelial cells in vitro in the model of xenotransplantation

    International Nuclear Information System (INIS)

    Huang Haoyue; Shen Zhenya; Liu Hongcheng; Meng Zili; Teng Xiaomei

    2004-01-01

    Objective: To explore the change of the cytotoxicity of natural killer cells induced by vascular endothelial cells in vitro and the relationship between this change and the variety of cytokine level. Methods: After fixed by paraformaldehyde, vascular endothelial cells from pigs were co-cultured in vitro with natural killer cells from Chinese monkeys at different ratios. The change of the cytotoxicity of natural killer cells occurring after this contact and the content of IFN-γ and TNF-α in the supernatants were detected. Results: The cytotoxicity of natural killer cells improved gradually in accordance with the co-culture ratio after co-cultured with fixed vascular endothelial cells. The secretion of INF-γ and TNF-α also improved gradually. Conclusion: After contact with xeno-target cells, the cytotoxicity of natural killer cells and the secretion of cytokines are related to the ratio of effective cells and target cells

  7. Fast intracellular dissolution and persistent cellular uptake of silver nanoparticles in CHO-K1 cells: implication for cytotoxicity

    DEFF Research Database (Denmark)

    Jiang, Xiumei; Miclaus, Teodora; Wang, Liming

    2015-01-01

    . Subsequent cytotoxicity studies show that Ag NPs decrease cell viability and increase ROS production. Pre-incubation with N-acetyl-l-cysteine, an efficient antioxidant and Ag+ chelator, diminished the cytotoxicity caused by Ag NPs or Ag+ exposure. Our study suggests that the cytotoxicity mechanism of Ag NPs...

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

    International Nuclear Information System (INIS)

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

    2016-01-01

    showed high drug loading and encapsulation efficiency, 15.57 ± 0.84 and 100%, respectively. • Nanoparticles demonstrated a superior cellular uptake over non-targeted nanoparticles. • IC_5_0 of nanoparticles and IC_5_0 of free paclitaxel were 4.86 ± 0.91 and 32.80 ± 3.80 nM, respectively. • The imprinted nanoparticles showed high affinity to paclitaxel in biological samples.

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

    Energy Technology Data Exchange (ETDEWEB)

    Esfandyari-Manesh, Mehdi [Nanotechnology Research Center,Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Department of Chemistry, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Darvishi, Behrad [Nanotechnology Research Center,Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Ishkuh, Fatemeh Azizi [Department of Chemistry, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Shahmoradi, Elnaz [Department of Chemical Engineering, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Mohammadi, Ali [Nanotechnology Research Center,Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Department of Drug and Food Control, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Javanbakht, Mehran [Department of Chemistry, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Dinarvand, Rassoul [Nanotechnology Research Center,Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Atyabi, Fatemeh, E-mail: atyabifa@tums.ac.ir [Nanotechnology Research Center,Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2016-05-01

    showed high drug loading and encapsulation efficiency, 15.57 ± 0.84 and 100%, respectively. • Nanoparticles demonstrated a superior cellular uptake over non-targeted nanoparticles. • IC{sub 50} of nanoparticles and IC{sub 50} of free paclitaxel were 4.86 ± 0.91 and 32.80 ± 3.80 nM, respectively. • The imprinted nanoparticles showed high affinity to paclitaxel in biological samples.

  10. Antibody-dependent cellular cytotoxicity and neutralizing activity in sera of HIV-1-infected mothers and their children.

    Science.gov (United States)

    Broliden, K; Sievers, E; Tovo, P A; Moschese, V; Scarlatti, G; Broliden, P A; Fundaro, C; Rossi, P

    1993-01-01

    The prognostic and protective role of antibodies mediating cellular cytotoxicity (ADCC) and neutralization was evaluated in sera of HIV-1-infected mothers and their consecutively followed children. The presence and titres of ADCC mediating and/or neutralizing antibodies in maternal sera did not predict HIV-1 infection in their respective children. No significant difference in the sera from the children was seen when comparing the presence of neutralizing antibodies between the uninfected and infected children. Stratification of the infected group according to clinical status revealed differences. Only one of 24 AIDS patients had a high neutralizing titre against IIIB. Four patients had a very low titre and the remaining had no detectable neutralizing antibodies at all. In contrast, 10/17 infected non-AIDS children had neutralizing antibodies. Similarly, no significant difference was seen when comparing the presence of ADCC-mediating antibodies between the uninfected and the infected group of children. However, a significantly higher frequency of ADCC was seen in the seropositive non-AIDS children compared with the AIDS children. This study clearly shows that the presence of antibodies mediating ADCC and neutralization in infected children, 0-2 years old, is associated with a better clinical status and delayed disease progression. PMID:8324904

  11. Cellular changes in motor neuron cell culture produced by cytotoxic cerebrospinal fluid from patients with amyotrophic lateral sclerosis.

    Science.gov (United States)

    Gomez-Pinedo, U; Yáñez, M; Matías-Guiu, J; Galán, L; Guerrero-Sola, A; Benito-Martin, M S; Vela, A; Arranz-Tagarro, J A; García, A G

    2014-01-01

    The neurotoxic effects of cerebrospinal fluid (CSF) from patients with amyotrophic lateral sclerosis (ALS) have been reported by various authors who have attributed this neurotoxicity to the glutamate in CSF-ALS. Cultures of rat embryonic cortical neurons were exposed to CSF from ALS patients during an incubation period of 24 hours. Optical microscopy was used to compare cellular changes to those elicited by exposure to 100μm glutamate, and confocal microscopy was used to evaluate immunohistochemistry for caspase-3, TNFα, and peripherin. In the culture exposed to CSF-ALS, we observed cells with nuclear fragmentation and scarce or null structural modifications to the cytoplasmic organelles or to plasma membrane maintenance. This did not occur in the culture exposed to glutamate. The culture exposed to CSF-ALS also demonstrated increases in caspase-3, TNFα, and in peripherin co-locating with caspase-3, but not with TNFα, suggesting that TNFα may play an early role in the process of apoptosis. CFS-ALS cytotoxicity is not related to glutamate. It initially affects the nucleus without altering the cytoplasmic membrane. It causes cytoplasmic apoptosis that involves an increase in caspase-3 co-located with peripherin, which is also overexpressed. Copyright © 2013 Sociedad Española de Neurología. Published by Elsevier Espana. All rights reserved.

  12. 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.

    Science.gov (United States)

    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.

  13. Humanised IgG1 antibody variants targeting membrane-bound carcinoembryonic antigen by antibody-dependent cellular cytotoxicity and phagocytosis.

    Science.gov (United States)

    Ashraf, S Q; Umana, P; Mössner, E; Ntouroupi, T; Brünker, P; Schmidt, C; Wilding, J L; Mortensen, N J; Bodmer, W F

    2009-11-17

    The effect of glycoengineering a membrane specific anti-carcinoembryonic antigen (CEA) (this paper uses the original term CEA for the formally designated CEACAM5) antibody (PR1A3) on its ability to enhance killing of colorectal cancer (CRC) cell lines by human immune effector cells was assessed. In vivo efficacy of the antibody was also tested. The antibody was modified using EBNA cells cotransfected with beta-1,4-N-acetylglucosaminyltransferase III and the humanised hPR1A3 antibody genes. The resulting alteration of the Fc segment glycosylation pattern enhances the antibody's binding affinity to the FcgammaRIIIa receptor on human immune effector cells but does not alter the antibody's binding capacity. Antibody-dependent cellular cytotoxicity (ADCC) is inhibited in the presence of anti-FcgammaRIII blocking antibodies. This glycovariant of hPR1A3 enhances ADCC 10-fold relative to the parent unmodified antibody using either unfractionated peripheral blood mononuclear or natural killer (NK) cells and CEA-positive CRC cells as targets. NK cells are far more potent in eliciting ADCC than either freshly isolated monocytes or granulocytes. Flow cytometry and automated fluorescent microscopy have been used to show that both versions of hPR1A3 can induce antibody-dependent cellular phagocytosis (ADCP) by monocyte-derived macrophages. However, the glycovariant antibody did not mediate enhanced ADCP. This may be explained by the relatively low expression of FcgammaRIIIa on cultured macrophages. In vivo studies show the efficacy of glycoengineered humanised IgG1 PR1A3 in significantly improving survival in a CRC metastatic murine model. The greatly enhanced in vitro ADCC activity of the glycoengineered version of hPR1A3 is likely to be clinically beneficial.

  14. Cytotoxicity and cellular uptake of doxorubicin and its formamidine derivatives in HL60 sensitive and HL60/MX2 resistant cells.

    Science.gov (United States)

    Kik, Krzysztof; Wasowska-Lukawska, Malgorzata; Oszczapowicz, Irena; Szmigiero, Leszek

    2009-04-01

    In this work a comparison was made of the cytotoxicity and cellular uptake of doxorubicin (DOX) and two of its derivatives containing a formamidino group (-N=CH-N<) at the 3' position with morpholine (DOXM) or hexamethyleneimine (DOXH) ring. All tests were performed in doxorubicin-sensitive HL60 and -resistant HL60/MX2 cells which are known for the presence of altered topoisomerase II. Cytotoxic activity of DOX toward HL60/MX2 cells was about 195 times lower when compared with the sensitive HL60 cell line. DOXM and DOXH were approximately 20 times more active in resistant cells than DOX. It was found that the uptake of DOX was lower in resistant cells by about 16%, while that of DOXM and DOXH was lower by about 36% and 19%, respectively. Thus the changes in the cellular uptake of anthracyclines are not associated with the fact that cytotoxicity of DOXM and DOXH exceed the cytotoxicity of DOX. Experiments in cell-free system containing human topoisomerase II showed that topoisomerase II is not inhibited by DOXM and DOXH. Formamidinoanthracyclines may be more useful than parent drugs in therapy against tumor cells with altered topoisomerase II activity.

  15. Radiation prevulcanized natural rubber latex: Cytotoxicity and safety evaluation on animal

    Energy Technology Data Exchange (ETDEWEB)

    Keong, C C; Zin, W M Wan; Ibrahim, P; Ibrahim, S, E-mail: chai@nuclearmalaysia.gov.my [Malaysian Nuclear Agency, Bangi, 43000 Kajang, Selangor (Malaysia)

    2010-05-15

    Radiation prevulcanized natural rubber latex (RVNRL) was claimed to be more user friendly than natural rubber latex prevulcanized by sulphur curing system. The absence of Type IV allergy inducing chemicals in RVNRL make it a suitable material for manufacturing of many kinds of latex products, especially those come into direct contact with users. This paper reveals and discusses the findings of cytotoxicity test and safety evaluation on animal for RVNRL. The test was done on RVNRL films prepared by coagulant dipping method and RVNRL dipped products produced by latex dipped product manufacturers. Cytotocixity test was carried out on mammalian cell culture American Type Culture Collection CCL 81, Vero. Results indicated that no cytotoxic effect from RVNRL films and products was found on the cell culture. Two animal studies, namely dermal sensitization study and primary skin irritation study, were done on gloves made from RVNRL. Albino white guinea pigs were used as test subjects in dermal sensitization study and results showed no sensitization induced by the application of test material in the guinea pigs. Primary skin irritation study was done on New Zealand white rabbits and results showed that the product tested was not corrosive and was not a primary irritant

  16. Radiation prevulcanized natural rubber latex: Cytotoxicity and safety evaluation on animal

    International Nuclear Information System (INIS)

    Keong, C C; Zin, W M Wan; Ibrahim, P; Ibrahim, S

    2010-01-01

    Radiation prevulcanized natural rubber latex (RVNRL) was claimed to be more user friendly than natural rubber latex prevulcanized by sulphur curing system. The absence of Type IV allergy inducing chemicals in RVNRL make it a suitable material for manufacturing of many kinds of latex products, especially those come into direct contact with users. This paper reveals and discusses the findings of cytotoxicity test and safety evaluation on animal for RVNRL. The test was done on RVNRL films prepared by coagulant dipping method and RVNRL dipped products produced by latex dipped product manufacturers. Cytotocixity test was carried out on mammalian cell culture American Type Culture Collection CCL 81, Vero. Results indicated that no cytotoxic effect from RVNRL films and products was found on the cell culture. Two animal studies, namely dermal sensitization study and primary skin irritation study, were done on gloves made from RVNRL. Albino white guinea pigs were used as test subjects in dermal sensitization study and results showed no sensitization induced by the application of test material in the guinea pigs. Primary skin irritation study was done on New Zealand white rabbits and results showed that the product tested was not corrosive and was not a primary irritant

  17. Reducing the Cytotoxicity of Lipid Nanoparticles Associated with a Fusogenic Cationic Lipid in a Natural Killer Cell Line by Introducing a Polycation-Based siRNA Core.

    Science.gov (United States)

    Nakamura, Takashi; Yamada, Koharu; Fujiwara, Yuki; Sato, Yusuke; Harashima, Hideyoshi

    2018-06-04

    Introducing siRNA into human immune cells by an artificial delivery system continues to be a challenging issue. We previously developed a multifunctional envelope-type nanodevice (MEND) containing the YSK12-C4, a fusogenic cationic lipid, (YSK12-MEND) and succeeded in the efficient delivery of siRNA into human immune cell lines. Significant cytotoxicity, however, was observed at siRNA doses needed for gene silencing in NK-92 cells. NK-92 cells, a unique natural killer (NK) cell line, would be applicable for use in clinical NK therapy. Thus, reducing the cytotoxicity of the YSK12-MEND in NK-92 cells would strengthen the efficacy of NK-92 cell-based therapy. The amount of the YSK12-C4 in the MEND needed to be reduced to reduce the cytotoxicity, because the cytotoxicity was directly associated with the YSK12-C4. In the present study, we decreased the total amount of lipid, including the YSK12-C4, by introducing a core formed by electrostatic interactions of siRNA with a polycation (protamine) (siRNA core), which led to a decrease in cytotoxicity in NK-92 cells. We prepared a YSK12-MEND containing an siRNA core (YSK12-MEND/core) at charge ratios (CR: YSK12-C4/siRNA) of 10, 5, 3, and 2.5 and compared the YSK12-MEND/core with that for a YSK12-MEND (CR16.9). Cell viability was increased by more than 2 times at a CR5 or less. On the other hand, the YSK12-MEND/core (CR5) maintained the same gene silencing efficiency (60%) as the YSK12-MEND. Interestingly, the cellular uptake efficiency and hemolytic activity of the YSK12-MEND/core (CR5) was reduced compared to that for the YSK12-MEND. In calculating the silencing activity per cellular uptake efficiency and hemolytic activity, the value for the YSK12-MEND/core (CR5) was more than 2 times as high as that of the YSK12-MEND. The fact indicates that after endosomal escape, the process can be enhanced by using a YSK12-MEND/core (CR5). Thus, introducing an siRNA core into lipid nanoparticles can be a potent strategy for decreasing

  18. Irradiated KHYG-1 retains cytotoxicity: potential for adoptive immunotherapy with a natural killer cell line.

    Science.gov (United States)

    Suck, G; Branch, D R; Keating, A

    2006-05-01

    To evaluate gamma-irradiation on KHYG-1, a highly cytotoxic natural killer (NK) cell line and potential candidate for cancer immunotherapy. The NK cell line KHYG-1 was irradiated at 1 gray (Gy) to 50 Gy with gamma-irradiation, and evaluated for cell proliferation, cell survival, and cytotoxicity against tumor targets. We showed that a dose of at least 10 Gy was sufficient to inhibit proliferation of KHYG-1 within the first day but not its cytolytic activity. While 50 Gy had an apoptotic effect in the first hours after irradiation, the killing of K562 and HL60 targets was not different from non-irradiated cells but was reduced for the Ph + myeloid leukemia lines, EM-2 and EM-3. gamma-irradiation (at least 10 Gy) of KHYG-1 inhibits cell proliferation but does not diminish its enhanced cytolytic activity against several tumor targets. This study suggests that KHYG-1 may be a feasible immunotherapeutic agent in the treatment of cancers.

  19. Decreased Cytotoxicity of Peripheral and Peritoneal Natural Killer Cell in Endometriosis.

    Science.gov (United States)

    Jeung, InCheul; Cheon, Keunyoung; Kim, Mee-Ran

    2016-01-01

    Endometriosis causes significant chronic pelvic pain, dysmenorrhea, and infertility and affects 10% of all women. In endometriosis, ectopic endometrium surviving after retrograde menstruation exhibits an abnormal immune response characterized by increased levels of activated macrophages and inflammatory cytokines. Particularly, dysfunctional natural killer (NK) cells play an important role in the pathogenesis of the disease by either facilitating or inhibiting the survival, implantation, and proliferation of endometrial cells. NK cells in the peritoneum and peritoneal fluid exhibit reduced levels of cytotoxicity in women with endometriosis. Several cytokines and inhibitory factors in the serum and peritoneal fluid also dysregulate NK cell cytotoxicity. Additionally, increased numbers of immature peripheral NK cells and induction of NK cell apoptosis are evident in the peritoneal fluid of women with endometriosis. The high rate of endometriosis recurrence after pharmaceutical or surgical treatment, which is associated with dysfunctional NK cells, indicates that new immunomodulatory management strategies are required. A good understanding of immune dysfunction would enable improvement of current treatments for endometriosis.

  20. Decreased Cytotoxicity of Peripheral and Peritoneal Natural Killer Cell in Endometriosis

    Directory of Open Access Journals (Sweden)

    InCheul Jeung

    2016-01-01

    Full Text Available Endometriosis causes significant chronic pelvic pain, dysmenorrhea, and infertility and affects 10% of all women. In endometriosis, ectopic endometrium surviving after retrograde menstruation exhibits an abnormal immune response characterized by increased levels of activated macrophages and inflammatory cytokines. Particularly, dysfunctional natural killer (NK cells play an important role in the pathogenesis of the disease by either facilitating or inhibiting the survival, implantation, and proliferation of endometrial cells. NK cells in the peritoneum and peritoneal fluid exhibit reduced levels of cytotoxicity in women with endometriosis. Several cytokines and inhibitory factors in the serum and peritoneal fluid also dysregulate NK cell cytotoxicity. Additionally, increased numbers of immature peripheral NK cells and induction of NK cell apoptosis are evident in the peritoneal fluid of women with endometriosis. The high rate of endometriosis recurrence after pharmaceutical or surgical treatment, which is associated with dysfunctional NK cells, indicates that new immunomodulatory management strategies are required. A good understanding of immune dysfunction would enable improvement of current treatments for endometriosis.

  1. All-trans retinoic acid negatively regulates cytotoxic activities of nature killer cell line 92

    International Nuclear Information System (INIS)

    Li Ang; He Meilan; Wang Hui; Qiao Bin; Chen Ping; Gu Hua; Zhang Mengjie; He Shengxiang

    2007-01-01

    NK cells are key components of innate immune systems and their activities are regulated by cytokines and hormones. All-trans retinoic acid (ATRA), as a metabolite of vitamin A and an immunomodulatory hormone, plays an important role in regulating immune responses. In the present study, we investigated the effect of ATRA on human NK cell line NK92. We found that ATRA dose-dependently suppressed cytotoxic activities of NK92 cells without affecting their proliferation. To explore the mechanisms underlying the ATRA influence on NK92 cells, we examined the production of cytokines (TNF-α, IFN-γ), gene expression of cytotoxic-associated molecules (perforin, granzyme B, nature killer receptors (NCRs), and NKG2D), and the activation of NF-κB pathways related with immune response. Our results demonstrated that ATRA suppressed NF-κB activity and prevented IκBα degradation in a dose-dependent way, inhibited IFN-γ production and gene expression of granzyme B and NKp46. Our findings suggest that ATRA is a negative regulator of NK92 cell activation and may act as a potential regulator of anti-inflammatory functions in vivo

  2. Classification of human natural killer cells based on migration behavior and cytotoxic response.

    Science.gov (United States)

    Vanherberghen, Bruno; Olofsson, Per E; Forslund, Elin; Sternberg-Simon, Michal; Khorshidi, Mohammad Ali; Pacouret, Simon; Guldevall, Karolin; Enqvist, Monika; Malmberg, Karl-Johan; Mehr, Ramit; Önfelt, Björn

    2013-02-21

    Despite intense scrutiny of the molecular interactions between natural killer (NK) and target cells, few studies have been devoted to dissection of the basic functional heterogeneity in individual NK cell behavior. Using a microchip-based, time-lapse imaging approach allowing the entire contact history of each NK cell to be recorded, in the present study, we were able to quantify how the cytotoxic response varied between individual NK cells. Strikingly, approximately half of the NK cells did not kill any target cells at all, whereas a minority of NK cells was responsible for a majority of the target cell deaths. These dynamic cytotoxicity data allowed categorization of NK cells into 5 distinct classes. A small but particularly active subclass of NK cells killed several target cells in a consecutive fashion. These "serial killers" delivered their lytic hits faster and induced faster target cell death than other NK cells. Fast, necrotic target cell death was correlated with the amount of perforin released by the NK cells. Our data are consistent with a model in which a small fraction of NK cells drives tumor elimination and inflammation.

  3. Discovery of DNA Topoisomerase I Inhibitors with Low-Cytotoxicity Based on Virtual Screening from Natural Products

    Directory of Open Access Journals (Sweden)

    Lan-Ting Xin

    2017-07-01

    Full Text Available Currently, DNA topoisomerase I (Topo I inhibitors constitute a family of antitumor agents with demonstrated clinical effects on human malignancies. However, the clinical uses of these agents have been greatly limited due to their severe toxic effects. Therefore, it is urgent to find and develop novel low toxic Topo I inhibitors. In recent years, during our ongoing research on natural antitumor products, a collection of low cytotoxic or non-cytotoxic compounds with various structures were identified from marine invertebrates, plants, and their symbiotic microorganisms. In the present study, new Topo I inhibitors were discovered from low cytotoxic and non-cytotoxic natural products by virtual screening with docking simulations in combination with bioassay test. In total, eight potent Topo I inhibitors were found from 138 low cytotoxic or non-cytotoxic compounds from coral-derived fungi and plants. All of these Topo I inhibitors demonstrated activities against Topo I-mediated relaxation of supercoiled DNA at the concentrations of 5–100 µM. Notably, the flavonoids showed higher Topo I inhibitory activities than other compounds. These newly discovered Topo I inhibitors exhibited structurally diverse and could be considered as a good starting point for the development of new antitumor lead compounds.

  4. Luminescent cyclometalated iridium(III) polypyridine indole complexes--synthesis, photophysics, electrochemistry, protein-binding properties, cytotoxicity, and cellular uptake.

    Science.gov (United States)

    Lau, Jason Shing-Yip; Lee, Pui-Kei; Tsang, Keith Hing-Kit; Ng, Cyrus Ho-Cheong; Lam, Yun-Wah; Cheng, Shuk-Han; Lo, Kenneth Kam-Wing

    2009-01-19

    A series of luminescent cyclometalated iridium(III) polypyridine indole complexes, [Ir(N--C)(2)(N--N)](PF(6)) (HN--C = 2-phenylpyridine (Hppy), N--N = 4-((2-(indol-3-yl)ethyl)aminocarbonyl)-4'-methyl-2,2'-bipyridine (bpy-ind) (1a), N--N = 4-((5-((2-(indol-3-yl)ethyl)aminocarbonyl)pentyl)aminocarbonyl)-4'-methyl-2,2'-bipyridine (bpy-C6-ind) (1b); HN--C = 7,8-benzoquinoline (Hbzq), N--N = bpy-ind (2a), N--N = bpy-C6-ind (2b); and HN--C = 2-phenylquinoline (Hpq), N--N = bpy-ind (3a), N--N = bpy-C6-ind (3b)), have been synthesized, characterized, and their photophysical and electrochemical properties and lipophilicity investigated. Photoexcitation of the complexes in fluid solutions at 298 K and in alcohol glass at 77 K resulted in intense and long-lived luminescence (lambda(em) = 540-616 nm, tau(o) = 0.13-5.15 mus). The emission of the complexes has been assigned to a triplet metal-to-ligand charge-transfer ((3)MLCT) (dpi(Ir) --> pi*(N--N)) excited state, probably with some mixing of triplet intraligand ((3)IL) (pi --> pi*) (pq) character for complexes 3a,b. Electrochemical measurements revealed that all the complexes showed an irreversible indole oxidation wave at ca. +1.1 V versus SCE, a quasi-reversible iridium(IV/III) couple at ca. +1.3 V, and a reversible diimine reduction couple at ca. -1.3 V. The interactions of these complexes with an indole-binding protein, bovine serum albumin (BSA), have been studied by emission titrations, and the K(a) values are on the order of 10(4) M(-1). Additionally, the cytotoxicity of the complexes toward human cervix epithelioid carcinoma (HeLa) cells has been examined by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyltetrazolium bromide (MTT) assay. The IC(50) values of the complexes ranged from 1.1 to 6.3 microM, which are significantly smaller than that of cisplatin (30.7 microM) under the same experimental conditions. Furthermore, the cellular uptake of the complexes has been investigated by flow cytometry and laser

  5. ChLpMab-23: Cancer-Specific Human-Mouse Chimeric Anti-Podoplanin Antibody Exhibits Antitumor Activity via Antibody-Dependent Cellular Cytotoxicity.

    Science.gov (United States)

    Kaneko, Mika K; Nakamura, Takuro; Kunita, Akiko; Fukayama, Masashi; Abe, Shinji; Nishioka, Yasuhiko; Yamada, Shinji; Yanaka, Miyuki; Saidoh, Noriko; Yoshida, Kanae; Fujii, Yuki; Ogasawara, Satoshi; Kato, Yukinari

    2017-06-01

    Podoplanin is expressed in many cancers, including oral cancers and brain tumors. The interaction between podoplanin and its receptor C-type lectin-like receptor 2 (CLEC-2) has been reported to be involved in cancer metastasis and tumor malignancy. We previously established many monoclonal antibodies (mAbs) against human podoplanin using the cancer-specific mAb (CasMab) technology. LpMab-23 (IgG 1 , kappa), one of the mouse anti-podoplanin mAbs, was shown to be a CasMab. However, we have not shown the usefulness of LpMab-23 for antibody therapy against podoplanin-expressing cancers. In this study, we first determined the minimum epitope of LpMab-23 and revealed that Gly54-Leu64 peptide, especially Gly54, Thr55, Ser56, Glu57, Asp58, Arg59, Tyr60, and Leu64 of podoplanin, is a critical epitope of LpMab-23. We further produced human-mouse chimeric LpMab-23 (chLpMab-23) and investigated whether chLpMab-23 exerts antibody-dependent cellular cytotoxicity (ADCC) and antitumor activity. In flow cytometry, chLpMab-23 showed high sensitivity against a podoplanin-expressing glioblastoma cell line, LN319, and an oral cancer cell line, HSC-2. chLpMab-23 also showed ADCC activity against podoplanin-expressing CHO cells (CHO/podoplanin). In xenograft models with HSC-2 and CHO/podoplanin, chLpMab-23 exerts antitumor activity using human natural killer cells, indicating that chLpMab-23 could be useful for antibody therapy against podoplanin-expressing cancers.

  6. Structural Basis for Degenerate Recognition of Natural HIV Peptide Variants by Cytotoxic Lymphocytes

    International Nuclear Information System (INIS)

    Martinez-Hackert, E.; Anikeeva, N.; Kalams, S.; Walker, B.; Hendrickson, W.; Sykulev, Y.

    2006-01-01

    It is well established that even small changes in amino acid side chains of antigenic peptide bound to MHC protein may completely abrogate recognition of the peptide-MHC (pMHC) complex by the T-cell receptor (TCR). Often, however, several non-conservative substitutions in the peptide antigen are accommodated and do not impair its recognition by TCR. For example, a preponderance of natural sequence variants of the HIV p17 Gag-derived peptide SLYNTVATL (SL9) are recognized by cytotoxic T lymphocytes (CTL), which implies that interactions with SL9 variants are degenerate both with respect to the class I MHC molecule and with respect to TCR. Here we study the molecular basis for this degenerate recognition of SL9 variants. We show that several SL9 variants bind comparably well to soluble HLA-A2 and to a particular soluble TCR and that these variants are active in the cognate cytotoxicity assay. Natural SL9 variation is restricted by its context in the HIV p17 matrix protein, and we have used synthetic variants to explore the wider spectrum of recognition. High-resolution crystal structures of seven selected SL9 variants bound to HLA-A2 all have remarkably similar peptide conformations and side-chain dispositions outside sites of substitution. This preservation of the peptide conformation despite epitope variations suggests a mechanism for the observed degeneracy in pMHC recognition by TCR, and may contribute to the persistence of SL9-mediated immune responses in chronically infected individuals

  7. Cytotoxicity and cellular uptake of pyrimidine nucleosides for imaging herpes simplex type-1 thymidine kinase (HSV-1 TK) expression in mammalian cells

    Energy Technology Data Exchange (ETDEWEB)

    Morin, Kevin W.; Duan Weili; Xu Lihua; Zhou Aihua; Moharram, Sameh; Knaus, Edward E.; McEwan, Alexander J.B.; Wiebe, Leonard I. E-mail: leonard.wiebe@ualberta.ca

    2004-07-01

    In vivo transfer of the herpes simplex virus type-1 thymidine kinase (HSV-1 TK) gene, with subsequent administration of antiviral drugs such as ganciclovir, has emerged as a promising gene therapy protocol for treating proliferative disorders. The in vitro cytotoxicities (IC{sub 50}) for two series of 5-iodo- and (E)-5-(2-iodovinyl)-substituted 2'-deoxy- and 2'-deoxy-2'-fluoro-pyrimidine nucleosides ranged from millimolar to low nanomolar concentrations in mammalian tumor cell lines (KBALB; R-970-5; 143B; EMT-6) and their counterparts engineered to express HSV-1 TK (KBALB-STK; 143B-LTK). Their HSV-1 TK selectivity indices ranged from one (nonselective) to one million (highly selective) based on cytotoxicity, with FIRU being the least toxic to all cell lines, and FIAU being most toxic. HSV-1 TK selectivity, based on uptake, ranged from 10 to 140, with IVDU being most selective for HSV-1 TK expressing cells, followed by IVFRU, FIRU, FIAU, IVFAU and finally IUDR. Phosphorylation of [{sup 125}I]FIAU led to incorporation of the radiolabel into nucleic acids, whereas IVFRU and FIRU radioactivity was trapped primarily in the nucleotide pool. These data indicate that cytotoxicity does not depend on initial metabolic trapping (e.g., phosphorylation), but on elaboration of the mononucleotides to more cytotoxic anabolites. Lipophilicities and nucleoside transport rates of the six nucleosides tested were within narrow ranges. This supports the premise that cellular biochemistry, and not cellular bioavailability, is responsible for the observed broad range of cytotoxicity and trapping. In vivo biodistribution studies with 5-[{sup 125}I]iodo-2'-fluoro-2'-deoxyribouridine (FIRU), 5-[{sup 125}I]iodo-2'-fluoro-2'-deoxyarabinouridine (FIAU) and (E)-5-(2-[{sup 125}I]iodovinyl)-2'-fluoro-2'-deoxyuridine (IVFRU) demonstrate selective accumulation of all three radiotracers in HSV-1 TK-expressing KBABK-STK tumors, compared to their very low

  8. Natural cytotoxicity in immunodeficiency diseases: preservation of natural killer activity and the in vivo appearance of radioresistant killing

    International Nuclear Information System (INIS)

    Pierce, G.F.; Polmar, S.H.; Schacter, B.Z.; Brovall, C.; Hornick, D.L.; Sorensen, R.U.

    1986-01-01

    We studied spontaneous natural killer (NK) cell activity and radiation-resistant NK mediated cytotoxicity in four patients with clinically documented severe combined immune deficiency disease (SCID), and in one subject each with intestinal lymphangiectasia and cartilage-hair hypoplasia. We observed the preservation of spontaneous NK activity in all patients despite the presence of profound B- and T-lymphocytopenia and clinical immunodeficiency. NK activity was associated with relatively normal circulating numbers of OKM1+ lymphocytes, a population known to contain NK effectors. Spontaneous NK activity resistant to 3000 rad was increased in all patients, indicating the presence of activated natural killer cells in vivo. The concept of a chronically activated immune system in these patients was further supported by the presence of increased Ia positive T cells in all subjects tested, suggesting that radioresistant NK activity may be a useful parameter to measure when assessing in vivo immune activation. Our data, as well as that of others, supports the hypothesis that at least one population of NK cells is a distinct lineage arising at the differentiation level of myeloid and lymphoid stem cells in the bone marrow

  9. The Effectiveness of Natural Diarylheptanoids against Trypanosoma cruzi: Cytotoxicity, Ultrastructural Alterations and Molecular Modeling Studies.

    Directory of Open Access Journals (Sweden)

    Vitor Sueth-Santiago

    Full Text Available Curcumin (CUR is the major constituent of the rhizomes of Curcuma longa and has been widely investigated for its chemotherapeutic properties. The well-known activity of CUR against Leishmania sp., Trypanosoma brucei and Plasmodium falciparum led us to investigate its activity against Trypanosoma cruzi. In this work, we tested the cytotoxic effects of CUR and other natural curcuminoids on different forms of T. cruzi, as well as the ultrastructural changes induced in epimastigote form of the parasite. CUR was verified as the curcuminoid with more significant trypanocidal properties (IC50 10.13 μM on epimastigotes. Demethoxycurcumin (DMC was equipotent to CUR (IC50 11.07 μM, but bisdemethoxycurcumin (BDMC was less active (IC50 45.33 μM and cyclocurcumin (CC was inactive. In the experiment with infected murine peritoneal macrophages all diarylheptanoids were more active than the control in the inhibition of the trypomastigotes release. The electron microscopy images showed ultrastructural changes associated with the cytoskeleton of the parasite, indicating tubulin as possible target of CUR in T. cruzi. The results obtained by flow cytometry analysis of DNA content of the parasites treated with natural curcuminoids suggested a mechanism of action on microtubules related to the paclitaxel`s mode of action. To better understand the mechanism of action highlighted by electron microscopy and flow cytometry experiments we performed the molecular docking of natural curcuminoids on tubulin of T. cruzi in a homology model and the results obtained showed that the observed interactions are in accordance with the IC50 values found, since there CUR and DMC perform similar interactions at the binding site on tubulin while BDMC do not realize a hydrogen bond with Lys163 residue due to the absence of methoxyl groups. These results indicate that trypanocidal properties of CUR may be related to the cytoskeletal alterations.

  10. In vitro evaluation of the cytotoxicity and cellular uptake of CMCht/PAMAM dendrimer nanoparticles by glioblastoma cell models

    Energy Technology Data Exchange (ETDEWEB)

    Pojo, M., E-mail: martapojo@ecsaude.uminho.pt; Cerqueira, S. R.; Mota, T.; Xavier-Magalhaes, A.; Ribeiro-Samy, S. [University of Minho, Life and Health Sciences Research Institute (ICVS), School of Health Sciences (Portugal); Mano, J. F.; Oliveira, J. M., E-mail: miguel.oliveira@dep.uminho.pt; Reis, R. L. [ICVS/3Bs, PT Government Associated Laboratory (Portugal); Sousa, N.; Costa, B. M.; Salgado, A. J. [University of Minho, Life and Health Sciences Research Institute (ICVS), School of Health Sciences (Portugal)

    2013-05-15

    Glioblastoma (GBM) is simultaneously the most common and most malignant subtype tumor of the central nervous system. These are particularly dramatic diseases ranking first among all human tumor types for tumor-related average years of life lost and for which curative therapies are not available. Recently, the use of nanoparticles as drug delivery systems (DDS) for tumor treatment has gained particular interest. In an attempt to evaluate the potential of carboxymethylchitosan/poly(amidoamine) (CMCht/PAMAM) dendrimer nanoparticles as a DDS, we aimed to evaluate its cytotoxicity and internalization efficiency in GBM cell models. CMCht/PAMAM-mediated cytotoxicity was evaluated in a GBM cell line (U87MG) and in human immortalized astrocytes (hTERT/E6/E7) by MTS and double-stranded DNA quantification. CMCht/PAMAM internalization was assessed by double fluorescence staining. Both cells lines present similar internalization kinetics when exposed to a high dose (400 {mu}g/mL) of these nanoparticles. However, the internalization rate was higher in tumor GBM cells as compared to immortalized astrocytes when cells were exposed to lower doses (200 {mu}g/mL) of CMCht/PAMAM for short periods (<24 h). After 48 h of exposure, both cell lines present {approx}100% of internalization efficiency for the tested concentrations. Importantly, short-term exposures (1, 6, 12, 24, and 48 h) did not show cytotoxicity, and long-term exposures (7 days) to CMCht/PAMAM induced only low levels of cytotoxicity in both cell lines ({approx}20% of decrease in metabolic activity). The high efficiency and rate of internalization of CMCht/PAMAM we show here suggest that these nanoparticles may be an attractive DDS for brain tumor treatment in the future.

  11. Cytotoxicity Study of Cyclopentapeptide Analogues of Marine Natural Product Galaxamide towards Human Breast Cancer Cells

    Directory of Open Access Journals (Sweden)

    Jignesh Lunagariya

    2017-01-01

    Full Text Available Herein, we report the cytotoxicity of cyclopentapeptide analogues of marine natural product galaxamide towards breast carcinoma cells and the underlying mechanisms. We examined the effect of the novel galaxamide analogues on cancer cell proliferation by MTT assay and also further examined the most active compound for morphological changes using Hoechst33342 staining technique, induction of apoptosis, cell cycle phases, mitochondrial membrane potential (MMP, and reactive oxygen species (ROS generation using flow cytometry in human breast cancer MCF-7 cells in vitro. Galaxamide and its analogues effectively induced toxicity in human hepatocellular carcinoma HepG2, human breast carcinoma MCF-7, human epitheloid cervix carcinoma HeLa, and human breast carcinoma MB-MDA-231 cell lines. Amongst them, compound 3 exhibited excellent toxicity towards MCF-7 cells. This galaxamide analogue significantly induced apoptosis in a dose-dependent manner in MCF-7 cells involves cell cycle arrest in the G1 phase, a reduction of MMP, and a marked increase in generation of ROS. Particularly, compound 3 of galaxamide analogues might be a potential candidate for the treatment of breast cancer.

  12. The Natural Killer Cell Cytotoxic Function Is Modulated by HIV-1 Accessory Proteins

    Directory of Open Access Journals (Sweden)

    Edward Barker

    2011-07-01

    Full Text Available Natural killer (NK cells’ major role in the control of viruses is to eliminate established infected cells. The capacity of NK cells to kill virus-infected cells is dependent on the interactions between ligands on the infected cell and receptors on the NK cell surface. Because of the importance of ligand-receptor interactions in modulating the NK cell cytotoxic response, HIV has developed strategies to regulate various NK cell ligands making the infected cell surprisingly refractory to NK cell lysis. This is perplexing because the HIV-1 accessory protein Vpr induces expression of ligands for the NK cell activating receptor, NKG2D. In addition, the accessory protein Nef removes the inhibitory ligands HLA-A and -B. The reason for the ineffective killing by NK cells despite the strong potential to eliminate infected cells is due to HIV-1 Vpu’s ability to down modulate the co-activation ligand, NTB-A, from the cell surface. Down modulation of NTB-A prevents efficient NK cell degranulation. This review will focus on the mechanisms through which the HIV-1 accessory proteins modulate their respective ligands, and its implication for NK cell killing of HIV-infected cells.

  13. Determination of spectral markers of cytotoxicity and genotoxicity using in vitro Raman microspectroscopy: cellular responses to polyamidoamine dendrimer exposure.

    Science.gov (United States)

    Efeoglu, Esen; Casey, Alan; Byrne, Hugh J

    2017-10-09

    Although consumer exposure to nanomaterials is ever increasing, with potential increased applications in areas such as drug and/or gene delivery, contrast agents and diagnosis, the determination of the cyto- and geno-toxic effects of nanomaterials on human health and the environment still remains challenging. Although many techniques have been established and adapted to determine the cytotoxicity and genotoxicity of nano-sized materials, these techniques remain limited by the number of assays required, total cost, and use of labels and they struggle to explain the underlying interaction mechanisms. In this study, Raman microspectroscopy is employed as an in vitro label-free, high content screening technique to observe toxicological changes within the cell in a multi-parametric fashion. The evolution of spectral markers as a function of time and applied dose has been used to elucidate the mechanism of action of polyamidoamine (PAMAM) dendrimers associated with cytotoxicity and their impact on nuclear biochemistry. PAMAM dendrimers are chosen as a model nanomaterial due to their widely studied cytotoxic and genotoxic properties and commercial availability. Point spectra were acquired from the cytoplasm to monitor the cascade of toxic events occurring in the cytoplasm upon nanoparticle exposure, whereas the spectra acquired from the nucleus and the nucleolus were used to explore PAMAM-nuclear material interaction as well as genotoxic responses.

  14. Dopamine receptors modulate cytotoxicity of natural killer cells via cAMP-PKA-CREB signaling pathway.

    Directory of Open Access Journals (Sweden)

    Wei Zhao

    Full Text Available Dopamine (DA, a neurotransmitter in the nervous system, has been shown to modulate immune function. We have previously reported that five subtypes of DA receptors, including D1R, D2R, D3R, D4R and D5R, are expressed in T lymphocytes and they are involved in regulation of T cells. However, roles of these DA receptor subtypes and their coupled signal-transduction pathway in modulation of natural killer (NK cells still remain to be clarified. The spleen of mice was harvested and NK cells were isolated and purified by negative selection using magnetic activated cell sorting. After NK cells were incubated with various drugs for 4 h, flow cytometry measured cytotoxicity of NK cells against YAC-1 lymphoma cells. NK cells expressed the five subtypes of DA receptors at mRNA and protein levels. Activation of D1-like receptors (including D1R and D5R with agonist SKF38393 enhanced NK cell cytotoxicity, but activation of D2-like receptors (including D2R, D3R and D4R with agonist quinpirole attenuated NK cells. Simultaneously, SKF38393 elevated D1R and D5R expression, cAMP content, and phosphorylated cAMP-response element-binding (CREB level in NK cells, while quinpirole reduced D3R and D4R expression, cAMP content, and phosphorylated CREB level in NK cells. These effects of SKF38393 were blocked by SCH23390, an antagonist of D1-like receptors, and quinpirole effects were abolished by haloperidol, an antagonist of D2-like receptors. In support these results, H89, an inhibitor of phosphokinase A (PKA, prevented the SKF38393-dependent enhancement of NK cells and forskolin, an activator of adenylyl cyclase (AC, counteracted the quinpirole-dependent suppression of NK cells. These findings show that DA receptor subtypes are involved in modulation of NK cells and suggest that D1-like receptors facilitate NK cells by stimulating D1R/D5R-cAMP-PKA-CREB signaling pathway and D2-like receptors suppress NK cells by inhibiting D3R/D4R-cAMP-PKA-CREB signaling pathway. The

  15. Killing defect of natural killer cells with the absence of natural killer cytotoxic factors in a child with Hodgkin's disease

    International Nuclear Information System (INIS)

    Komiyama, A.; Kawai, H.; Yamada, S.; Kato, M.; Yanagisawa, M.; Miyagawa, Y.; Akabane, T.

    1987-01-01

    A killing defect of natural killer (NK) cells in the absence of NK cytotoxic factors (NKCF) was first demonstrated in a child with Hodgkin's disease. The patient lacked detectable NK cell activity in every phase of the disease as measured by a four-hour 51 Cr-release assay using K562 cells as a target. The percent lysis at a 40:1 effector:target ratio by the patient's lymphocytes was persistently below 0.3% as compared with the normal lymphocyte value of 46.2% +/- 5.8% (mean +/- SD). NK cell activity was not detectable at effector:target ratios of 10:1 to 80:1 and by prolongation of the incubation time, and the NK cell defect was not restored or improved by lymphocyte stimulation with polyinosinic-polycytidilic acid, interferon (IFN)-alpha, or interleukin 2 (IL 2). The numbers of Leu-7+ cells and Leu-11+ cells were normal as counted by flow cytometry. A single cell-in-agarose assay demonstrated normal numbers of target binding cells (TBCs), and they showed the morphology of large granular lymphocytes. However, there were no TBCs with dead targets. These results indicated that the patient's lymphocytes contained normal numbers of NK cells that were capable of recognizing and binding to a target but were incapable of killing the bound target cell. The patient's lymphocytes were then studied for their release of NKCF upon interaction with K562 cells. The patient's cells did not release NKCF, and the NK cell defect was not restored or improved by stimulation of the cells with IFN or IL 2. It is suggested that the deficient release of NKCF may have been related to the killing defect of the NK cells in this patient

  16. Membrane adsorption and binding, cellular uptake and cytotoxicity of cell-penetrating peptidomimetics with α-peptide/β-peptoid backbone

    DEFF Research Database (Denmark)

    Jing, Xiaona; Yang, Mingjun; Kasimova, Marina Robertovna

    2012-01-01

    to evaluate the effect of α-chirality in the β-peptoid residues and the presence of guanidinium groups in the α-amino acid residues on membrane interaction. The molecular properties of the peptidomimetics in solution (surface and intramolecular hydrogen bonding, aqueous diffusion rate and molecular size) were...... studied along with their adsorption to lipid bilayers, cellular uptake, and toxicity. The surface hydrogen bonding ability of the peptidomimetics reflected their adsorbed amounts onto lipid bilayers as well as with their cellular uptake, indicating the importance of hydrogen bonding for their membrane...

  17. Role of IL-2 and interferon in the generation of natural cytotoxic activity in influenza virus-stimulated PBL cultures: analysis with the use of prednisolone

    NARCIS (Netherlands)

    Braakman, E.; Treep-van Leeuwen, P.; ten Berge, R. J.; Schellekens, P. T.; Lucas, C. J.

    1988-01-01

    We have examined the role of interleukin 2, interferon-gamma and interferon-alpha in the generation of natural cytotoxic (NC) activity and cytotoxic T-lymphocyte (CTL) activity in peripheral blood lymphocyte cultures stimulated with influenza virus, using the immunosuppressive effects of

  18. PLGA-soya lecithin based micelles for enhanced delivery of methotrexate: Cellular uptake, cytotoxic and pharmacokinetic evidences.

    Science.gov (United States)

    Singh, Anupama; Thotakura, Nagarani; Kumar, Rajendra; Singh, Bhupinder; Sharma, Gajanand; Katare, Om Prakash; Raza, Kaisar

    2017-02-01

    Biocompatible and biodegradable polymers like PLGA have revolutionized the drug delivery approaches. However, poor drug loading and substantially high lipophilicity, pave a path for further tailing of this promising agent. In this regard, PLGA was feathered with biocompatible phospholipid and polymeric micelles were developed for delivery of Methotrexate (MTX) to cancer cells. The nanocarriers (114.6nm±5.5nm) enhanced the cytotoxicity of MTX by 2.13 folds on MDA-MB-231 cells. Confocal laser scanning microscopy confirmed the increased intracellular delivery. The carrier decreased the protein binding potential and enhanced the bioavailable fraction of MTX. Pharmacokinetic studies vouched substantial enhancement in AUC and bioresidence time, promising an ideal carrier to effectively deliver the drug to the site of action. The developed nanocarriers offer potential to deliver the drug in the interiors of cancer cells in an effective manner for improved therapeutic action. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Extending in silico mechanism-of-action analysis by annotating targets with pathways: application to cellular cytotoxicity readouts.

    Science.gov (United States)

    Liggi, Sonia; Drakakis, Georgios; Koutsoukas, Alexios; Cortes-Ciriano, Isidro; Martínez-Alonso, Patricia; Malliavin, Thérèse E; Velazquez-Campoy, Adrian; Brewerton, Suzanne C; Bodkin, Michael J; Evans, David A; Glen, Robert C; Carrodeguas, José Alberto; Bender, Andreas

    2014-01-01

    An in silico mechanism-of-action analysis protocol was developed, comprising molecule bioactivity profiling, annotation of predicted targets with pathways and calculation of enrichment factors to highlight targets and pathways more likely to be implicated in the studied phenotype. The method was applied to a cytotoxicity phenotypic endpoint, with enriched targets/pathways found to be statistically significant when compared with 100 random datasets. Application on a smaller apoptotic set (10 molecules) did not allowed to obtain statistically relevant results, suggesting that the protocol requires modification such as analysis of the most frequently predicted targets/annotated pathways. Pathway annotations improved the mechanism-of-action information gained by target prediction alone, allowing a better interpretation of the predictions and providing better mapping of targets onto pathways.

  20. Shedding of Ebola Virus Surface Glycoprotein Is a Mechanism of Self-regulation of Cellular Cytotoxicity and Has a Direct Effect on Virus Infectivity.

    Science.gov (United States)

    Dolnik, Olga; Volchkova, Valentina A; Escudero-Perez, Beatriz; Lawrence, Philip; Klenk, Hans-Dieter; Volchkov, Viktor E

    2015-10-01

    The surface glycoprotein (GP) is responsible for Ebola virus (EBOV) attachment and membrane fusion during virus entry. Surface expression of highly glycosylated GP causes marked cytotoxicity via masking of a wide range of cellular surface molecules, including integrins. Considerable amounts of surface GP are shed from virus-infected cells in a soluble truncated form by tumor necrosis factor α-converting enzyme. In this study, the role of GP shedding was investigated using a reverse genetics approach by comparing recombinant viruses possessing amino acid substitutions at the GP shedding site. Virus with an L635V substitution showed a substantial decrease in shedding, whereas a D637V substitution resulted in a striking increase in the release of shed GP. Variations in shedding efficacy correlated with observed differences in the amounts of shed GP in the medium, GP present in virus-infected cells, and GP present on virions. An increase in shedding appeared to be associated with a reduction in viral cytotoxicity, and, vice versa, the virus that shed less was more cytotoxic. An increase in shedding also resulted in a reduction in viral infectivity, whereas a decrease in shedding efficacy enhanced viral growth characteristics in vitro. Differences in shedding efficacy and, as a result, differences in the amount of mature GP available for incorporation into budding virions did not equate to differences in overall release of viral particles. Likewise, data suggest that the resulting differences in the amount of mature GP on the cell surface led to variations in the GP content of released particles and, as a consequence, in infectivity. In conclusion, fine-tuning of the levels of EBOV GP expressed at the surface of virus-infected cells via GP shedding plays an important role in EBOV replication by orchestrating the balance between optimal virion GP content and cytotoxicity caused by GP. © The Author 2015. Published by Oxford University Press on behalf of the Infectious

  1. Chimeric Anti-Human Podoplanin Antibody NZ-12 of Lambda Light Chain Exerts Higher Antibody-Dependent Cellular Cytotoxicity and Complement-Dependent Cytotoxicity Compared with NZ-8 of Kappa Light Chain.

    Science.gov (United States)

    Kaneko, Mika K; Abe, Shinji; Ogasawara, Satoshi; Fujii, Yuki; Yamada, Shinji; Murata, Takeshi; Uchida, Hiroaki; Tahara, Hideaki; Nishioka, Yasuhiko; Kato, Yukinari

    2017-02-01

    Podoplanin (PDPN), a type I transmembrane 36-kDa glycoprotein, is expressed not only in normal cells, such as renal epithelial cells (podocytes), lymphatic endothelial cells, and pulmonary type I alveolar cells, but also in cancer cells, including brain tumors and lung squamous cell carcinomas. Podoplanin activates platelet aggregation by binding to C-type lectin-like receptor-2 (CLEC-2) on platelets, and the podoplanin/CLEC-2 interaction facilitates blood/lymphatic vessel separation. We previously produced neutralizing anti-human podoplanin monoclonal antibody (mAb), clone NZ-1 (rat IgG 2a , lambda), which neutralizes the podoplanin/CLEC-2 interaction and inhibits platelet aggregation and cancer metastasis. Human-rat chimeric antibody, NZ-8, was previously developed using variable regions of NZ-1 and human constant regions of heavy chain (IgG 1 ) and light chain (kappa chain). Although NZ-8 showed high antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) against human podoplanin-expressing cancer cells, the binding affinity of NZ-8 was lower than that of NZ-1. Herein, we produced a novel human-rat chimeric antibody, NZ-12, the constant regions of which consist of IgG 1 heavy chain and lambda light chain. Using flow cytometry, we demonstrated that the binding affinity of NZ-12 was much higher than that of NZ-8. Furthermore, ADCC and CDC activities of NZ-12 were significantly increased against glioblastoma cell lines (LN319 and D397) and lung cancer cell line (PC-10). These results suggested that NZ-12 could become a promising therapeutic antibody against podoplanin-expressing brain tumors and lung cancers.

  2. The Fanconi anemia proteins FAA and FAC function in different cellular compartments to protect against cross-linking agent cytotoxicity.

    Science.gov (United States)

    Kruyt, F A; Youssoufian, H

    1998-10-01

    Fanconi anemia (FA) is an autosomal recessive disease characterized by chromosomal instability, bone marrow failure, and a high risk of developing malignancies. Although the disorder is genetically heterogeneous, all FA cells are defined by their sensitivity to the apoptosis-inducing effect of cross-linking agents, such as mitomycin C (MMC). The cloned FA disease genes, FAC and FAA, encode proteins with no homology to each other or to any known protein. We generated a highly specific antibody against FAA and found the protein in both the cytoplasm and nucleus of mammalian cells. By subcellular fractionation, FAA is also associated with intracellular membranes. To identify the subcellular compartment that is relevant for FAA activity, we appended nuclear export and nuclear localization signals to the carboxy terminus of FAA and enriched its localization in either the cytoplasm or the nucleus. Nuclear localization of FAA was both necessary and sufficient to correct MMC sensitivity in FA-A cells. In addition, we found no evidence for an interaction between FAA and FAC either in vivo or in vitro. Together with a previous finding that FAC is active in the cytoplasm but not in the nucleus, our results indicate that FAA and FAC function in separate subcellular compartments. Thus, FAA and FAC, if functionally linked, are more likely to be in a linear pathway rather than form a macromolecular complex to protect against cross-linker cytotoxicity.

  3. Antibody dependent cellular phagocytosis (ADCP) and antibody dependent cellular cytotoxicity (ADCC) of breast cancer cells mediated by bispecific antibody, MDX-210.

    Science.gov (United States)

    Watanabe, M; Wallace, P K; Keler, T; Deo, Y M; Akewanlop, C; Hayes, D F

    1999-02-01

    MDX-210 is a bispecific antibody (BsAb) with specificity for both the proto-oncogene product of HER-2/neu (c-erbB-2) and FcgammaRI (CD64). HER-2/neu is overexpressed in malignant tissue of approximately 30% of patients with breast cancer, and FcgammaRI is expressed on human monocytes, macrophages, and IFN-gamma activated granulocytes. We investigated phagocytosis and cytolysis of cultured human breast cancer cells by human monocyte-derived macrophages (MDM) mediated by BsAb MDX-210, its partially humanized derivative (MDX-H210), and its parent MoAb 520C9 (anti-HER-2/neu) under various conditions. Purified monocytes were cultured with GM-CSF, M-CSF, or no cytokine for five or six days. Antibody dependent cellular phagocytosis (ADCP) and cytolysis (ADCC) assays were performed with the MDM and HER-2/neu positive target cells (SK-BR-3). ADCP was measured by two-color fluorescence flow cytometry using PKH2 (green fluorescent dye) and phycoerythrin-conjugated (red) monoclonal antibodies (MoAb) against human CD14 and CD11b. ADCC was measured with a non-radioactive LDH detection kit. Both BsAb MDX-210 (via FcgammaRI) and MoAb 520C9 (mouse IgG1, via FcgammaRII) mediated similar levels of ADCP and ADCC. ADCP mediated by BsAb MDX-H210 was identical to that mediated by BsAb MDX-210. Confocal microscopy demonstrated that dual-labeled cells represented true phagocytosis. Both ADCP and ADCC were higher when MDM were pre-incubated with GM-CSF than when incubated with M-CSF. BsAb MDX-210 is as active in vitro as the parent MoAb 520C9 in inducing both phagocytosis and cytolysis of MDM. MDX-210 and its partially humanized derivative, MDX-H210, mediated similar levels of ADCP. GM-CSF appears to superior to M-CSF in inducing MDM-mediated ADCC and ADCP. These studies support the ongoing clinical investigations of BsAb MDX-210 and its partially humanized derivative.

  4. Synthesis and biological activity of chimeric structures derived from the cytotoxic natural compounds dolastatin 10 and dolastatin 15.

    Science.gov (United States)

    Poncet, J; Busquet, M; Roux, F; Pierré, A; Atassi, G; Jouin, P

    1998-04-23

    The natural cytotoxic compounds dolastatins 10 and 15 exhibit great similarities in structure and in their biological activity profiles. Two compounds (1 and 2) formed by interchanging the dolaisoleuine residue of dolastatin 10 and the MeVal-Pro dipeptide of dolastatin 15 were synthesized in order to evaluate the possible equivalence of these units. These compounds can be considered as chimeras of dolastatins 10 and 15 formed by the N-terminal part of the former and the C-terminal part of the latter and vice versa. Both analogues exhibited a marked decrease in their cytotoxic activity but showed similar differential cytotoxicity with regard to the cell lines assayed compared with the parent compounds. HT-29 cell line was the least sensitive one. However, this activity was in the nanomolar level and close to that of vincristine. The differences in their effect on tubulin polymerization were less pronounced. We confirmed the already known crucial role of the Dil residue in this assay. The nonequivalence of the Dil unit and the MeVal-Pro dipeptide probably reflects modification in the relative positions of the N-dimethylamino and the phenyl moieties.

  5. Antitumor activity of chLpMab-2, a human-mouse chimeric cancer-specific antihuman podoplanin antibody, via antibody-dependent cellular cytotoxicity.

    Science.gov (United States)

    Kaneko, Mika K; Yamada, Shinji; Nakamura, Takuro; Abe, Shinji; Nishioka, Yasuhiko; Kunita, Akiko; Fukayama, Masashi; Fujii, Yuki; Ogasawara, Satoshi; Kato, Yukinari

    2017-04-01

    Human podoplanin (hPDPN), a platelet aggregation-inducing transmembrane glycoprotein, is expressed in different types of tumors, and it binds to C-type lectin-like receptor 2 (CLEC-2). The overexpression of hPDPN is involved in invasion and metastasis. Anti-hPDPN monoclonal antibodies (mAbs) such as NZ-1 have shown antitumor and antimetastatic activities by binding to the platelet aggregation-stimulating (PLAG) domain of hPDPN. Recently, we developed a novel mouse anti-hPDPN mAb, LpMab-2, using the cancer-specific mAb (CasMab) technology. In this study we developed chLpMab-2, a human-mouse chimeric anti-hPDPN antibody, derived from LpMab-2. chLpMab-2 was produced using fucosyltransferase 8-knockout (KO) Chinese hamster ovary (CHO)-S cell lines. By flow cytometry, chLpMab-2 reacted with hPDPN-expressing cancer cell lines including glioblastomas, mesotheliomas, and lung cancers. However, it showed low reaction with normal cell lines such as lymphatic endothelial and renal epithelial cells. Moreover, chLpMab-2 exhibited high antibody-dependent cellular cytotoxicity (ADCC) against PDPN-expressing cells, despite its low complement-dependent cytotoxicity. Furthermore, treatment with chLpMab-2 abolished tumor growth in xenograft models of CHO/hPDPN, indicating that chLpMab-2 suppressed tumor development via ADCC. In conclusion, chLpMab-2 could be useful as a novel antibody-based therapy against hPDPN-expressing tumors. © 2017 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

  6. Industrial grade 2D molybdenum disulphide (MoS2): an in vitro exploration of the impact on cellular uptake, cytotoxicity, and inflammation

    Science.gov (United States)

    Moore, Caroline; Movia, Dania; Smith, Ronan J.; Hanlon, Damien; Lebre, Filipa; Lavelle, Ed C.; Byrne, Hugh J.; Coleman, Jonathan N.; Volkov, Yuri; McIntyre, Jennifer

    2017-06-01

    The recent surge in graphene research, since its liquid phase monolayer isolation and characterization in 2004, has led to advancements which are accelerating the exploration of alternative 2D materials such as molybdenum disulphide (MoS2), whose unique physico-chemical properties can be exploited in applications ranging from cutting edge electronic devices to nanomedicine. However, to assess any potential impact on human health and the environment, the need to understand the bio-interaction of MoS2 at a cellular and sub-cellular level is critical. Notably, it is important to assess such potential impacts of materials which are produced by large scale production techniques, rather than research grade materials. The aim of this study was to explore cytotoxicity, cellular uptake and inflammatory responses in established cell-lines that mimic different potential exposure routes (inhalation, A549; ingestion, AGS; monocyte, THP-1) following incubation with MoS2 flakes of varying sizes (50 nm, 117 nm and 177 nm), produced by liquid phase exfoliation. Using high content screening (HCS) and Live/Dead assays, it was established that 1 µg ml-1 (for the three different MoS2 sizes) did not induce toxic effects on any of the cell-lines. Confocal microscopy images revealed a normal cellular morphology in all cases. Transmission electron microscopy (TEM) confirmed the uptake of all MoS2 nanomaterials in all the cell-lines, the MoS2 ultimately locating in single membrane vesicles. At such sub-lethal doses, inflammatory responses are observed, however, associated, at least partially, with the presence of lipopolysaccharide endotoxin in nanomaterial suspensions and surfactant samples. Therefore, the inflammatory response of the cells to the MoS2 or endotoxin contamination was interrogated using a 10-plex ELISA which illustrates cytokine production. The experiments carried out using wild-type and endotoxin hyporesponsive bone marrow derived dendritic cells confirmed that the

  7. Modulation in vitro and in vivo of cytotoxicity but not cellular levels of doxorubicin by the calmodulin inhibitor trifluoperazine is dependent on the level of resistance.

    Science.gov (United States)

    Ganapathi, R.; Schmidt, H.; Grabowski, D.; Melia, M.; Ratliff, N.

    1988-01-01

    The role of the calmodulin inhibitor trifluoperazine (TFP) in modulating the cellular levels and cytotoxicity in vitro and antitumour effects in vivo of doxorubicin (DOX), was evaluated in progressively DOX-resistant (5- to 40-fold) sublines of B16-BL6 mouse melanoma. In parental-sensitive B16-BL6 cells treated for 3 h, the IC50 of DOX was 0.1 microgram ml-1, and a less than 2-fold enhancement in DOX cell kill in the presence of a noncytotoxic concentration of 5 microM TFP was observed. However, in the DOX-resistant sublines, the IC50 was 0.7 to 5.0 micrograms ml-1 DOX in the absence of 5 microM TFP and 0.3 to 0.7 microgram ml-1 DOX in the presence of 5 microM TFP. The 2- to 7.5-fold decrease in the IC50 of DOX in the presence of 5 microM TFP, was dependent on the level of DOX-resistance in the various sublines. Compared to parental-sensitive cells, a 2-fold decrease in DOX-accumulation was evident only in the 40-fold DOX-resistant subline. Further, maximal enhancement (50%) of cellular DOX accumulation in the presence of 5 microM TFP was observed only in the 40-fold resistant cells treated with 5.0 micrograms ml-1 DOX. Retention of DOX in the 40-fold resistant subline was only 20% lower than similarly treated sensitive cells, and the inclusion of TFP increased DOX retention less than 10-15%. Antitumour studies in mice with experimental pulmonary metastases revealed that although DOX and DOX plus TFP had similar antitumour activity with the parental sensitive B16-BL6 cells, the combination of DOX plus TFP was significantly more effective than DOX alone with the DOX-resistant sublines. No overt toxicity was observed in normal mice treated with doses of TFP, DOX or DOX plus TFP used for in vivo chemotherapy studies. Results from this study suggest that gross cellular DOX levels do not appear to correlate with the magnitude of resistance, and the effects of TFP in modulating DOX resistance is possibly due to mechanisms other than mere alterations in cellular drug

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

    Directory of Open Access Journals (Sweden)

    Shuichi Kitayama

    2016-02-01

    Full Text Available 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.

  9. The Impact of HLA Class I-Specific Killer Cell Immunoglobulin-Like Receptors on Antibody-Dependent Natural Killer Cell-Mediated Cytotoxicity and Organ Allograft Rejection.

    Science.gov (United States)

    Rajalingam, Raja

    2016-01-01

    Natural killer (NK) cells of the innate immune system are cytotoxic lymphocytes that play an important roles following transplantation of solid organs and hematopoietic stem cells. Recognition of self-human leukocyte antigen (HLA) class I molecules by inhibitory killer cell immunoglobulin-like receptors (KIRs) is involved in the calibration of NK cell effector capacities during the developmental stage, allowing the subsequent recognition and elimination of target cells with decreased expression of self-HLA class I (due to virus infection or tumor transformation) or HLA class I disparities (in the setting of allogeneic transplantation). NK cells expressing an inhibitory KIR-binding self-HLA can be activated when confronted with allografts lacking a ligand for the inhibitory receptor. Following the response of the adaptive immune system, NK cells can further destroy allograft endothelium by antibody-dependent cell-mediated cytotoxicity (ADCC), triggered through cross-linking of the CD16 Fc receptor by donor-specific antibodies bound to allograft. Upon recognizing allogeneic target cells, NK cells also secrete cytokines and chemokines that drive maturation of dendritic cells to promote cellular and humoral adaptive immune responses against the allograft. The cumulative activating and inhibitory signals generated by ligation of the receptors regulates mature NK cell killing of target cells and their production of cytokines and chemokines. This review summarizes the role of NK cells in allograft rejection and proposes mechanistic concepts that indicate a prominent role for KIR-HLA interactions in facilitating NK cells for Fc receptor-mediated ADCC effector function involved in antibody-mediated rejection of solid organ transplants.

  10. The impact of HLA class I-specific killer cell immunoglobulin-like receptors on antibody-dependent natural killer cell-mediated cytotoxicity and organ allograft rejection

    Directory of Open Access Journals (Sweden)

    Raja Rajalingam

    2016-12-01

    Full Text Available Natural killer (NK cells of the innate immune system are cytotoxic lymphocytes that play important roles following transplantation of solid organs and hematopoietic stem cells. Recognition of self HLA class I molecules by inhibitory killer cell immunoglobulin-like receptors (KIR is involved in the calibration of NK cell effector capacities during a developmental stage, allowing the subsequent recognition and elimination of target cells with decreased expression of self HLA class I (due to virus infection or tumor transformation or HLA class I disparities (in the setting of allogeneic transplantation. NK cells expressing an inhibitory KIR binding self HLA can be activated when confronted with allografts lacking a ligand for the inhibitory receptor. Following the response of the adaptive immune system, NK cells can further destroy allograft endothelium by antibody-dependent cell-mediated cytotoxicity (ADCC, triggered through cross-linking of the CD16 Fc receptor by donor-specific antibodies bound to allograft. Upon recognizing allogeneic target cells, NK cells also secrete cytokines and chemokines that drive maturation of dendritic cells to promote cellular and humoral adaptive immune responses against the allograft. The cumulative activating and inhibitory signals generated by ligation of the receptors regulates mature NK cell killing of target cells and their production of cytokines and chemokines. This review summarizes the role of NK cells in allograft rejection and proposes mechanistic concepts that indicate a prominent role for KIR-HLA interactions in facilitating NK cells for Fc receptor-mediated ADCC effector function involved in antibody-mediated rejection of solid organ transplants.

  11. Noscapinoids bearing silver nanocrystals augmented drug delivery, cytotoxicity, apoptosis and cellular uptake in B16F1, mouse melanoma skin cancer cells.

    Science.gov (United States)

    Soni, Naina; Jyoti, Kiran; Jain, Upendra Kumar; Katyal, Anju; Chandra, Ramesh; Madan, Jitender

    2017-06-01

    Noscapine (Nos) and reduced brominated analogue of noscapine (Red-Br-Nos) prevent cellular proliferation and induce apoptosis in cancer cells either alone or in combination with other chemotherapeutic drugs. However, owing to poor physicochemical properties, Nos and Red-Br-Nos have demonstrated their anticancer activity at higher and multiple doses. Therefore, in present investigation, silver nanocrystals of noscapinoids (Nos-Ag 2+ nanocrystals and Red-Br-Nos-Ag 2+ nanocrystals) were customized to augment drug delivery, cytotoxicity, apoptosis and cellular uptake in B16F1 mouse melanoma cancer cells. Nos-Ag 2+ nanocrystals and Red-Br-Nos-Ag 2+ nanocrystals were prepared separately by precipitation method. The mean particle size of Nos-Ag 2+ nanocrystals was measured to be 25.33±3.52nm, insignificantly (P>0.05) different from 27.43±4.51nm of Red-Br-Nos-Ag 2+ nanocrystals. Furthermore, zeta-potential of Nos-Ag 2+ nanocrystals was determined to be -25.3±3.11mV significantly (Pcellular uptake. The Nos-Ag 2+ nanocrystals and Red-Br-Nos-Ag 2+ nanocrystals exhibited an IC 50 of 16.6μM and 6.5μM, significantly (Pcellular morphological alterations in B16F1 cells upon internalization of Nos-Ag 2+ nanocrystals and Red-Br-Nos-Ag 2+ nanocrystals provided the evidences for accumulation within membrane-bound cytoplasmic vacuoles and in enlarged lysosomes and thus triggered mitochondria mediated apoptosis via caspase activation. Preliminary investigations substantiated that Nos-Ag 2+ nanocrystals and Red-Br-Nos-Ag 2+ nanocrystals must be further explored and utilized for the delivery of noscapinoids to melanoma cancer cells. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  12. Cellular determinants involving mitochondrial dysfunction, oxidative stress and apoptosis correlate with the synergic cytotoxicity of epigallocatechin-3-gallate and menadione in human leukemia Jurkat T cells.

    Science.gov (United States)

    Tofolean, Ioana Teodora; Ganea, Constanta; Ionescu, Diana; Filippi, Alexandru; Garaiman, Alexandru; Goicea, Alexandru; Gaman, Mihnea-Alexandru; Dimancea, Alexandru; Baran, Irina

    2016-01-01

    We have investigated the growth-suppressive action of epigallocatechin-3-gallate (EGCG) on human leukemia Jurkat T cells. Results show a strong correlation between the dose-dependent reduction of clonogenic survival following acute EGCG treatments and the EGCG-induced decline of the mitochondrial level of Ca(2+). The cell killing ability of EGCG was synergistically enhanced by menadione. In addition, the cytotoxic effect of EGCG applied alone or in combination with menadione was accompanied by apoptosis induction. We also observed that in acute treatments EGCG displays strong antioxidant properties in the intracellular milieu, but concurrently triggers some oxidative stress generating mechanisms that can fully develop on a longer timescale. In parallel, EGCG dose-dependently induced mitochondrial depolarization during exposure, but this condition was subsequently reversed to a persistent hyperpolarized mitochondrial state that was dependent on the activity of respiratory Complex I. Fluorimetric measurements suggest that EGCG is a mitochondrial Complex III inhibitor and indicate that EGCG evokes a specific cellular fluorescence with emission at 400nm and two main excitation bands (at 330nm and 350nm) that may originate from a mitochondrial supercomplex containing dimeric Complex III and dimeric ATP-synthase, and therefore could provide a valuable means to characterize the functional properties of the respiratory chain. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. A King Bolete, Boletus edulis (Agaricomycetes), RNA Fraction Stimulates Proliferation and Cytotoxicity of Natural Killer Cells Against Myelogenous Leukemia Cells.

    Science.gov (United States)

    Lemieszek, Marta Kinga; Nunes, Fernando Herminio Ferreira Milheiro; Sawa-Wejksza, Katarzyna; Rzeski, Wojciech

    2017-01-01

    Numerous studies indicate the crucial role of natural killer (NK) cells in the prevention of tumor growth and inhibition of their metastasis, which suggests the possibility of their use in cancer treatment. This therapeutic strategy required finding a selective NK cell stimulator that, upon administration, did not disturb organism homeostasis, unlike natural activators (interleukin-2 or interleukin-12). Because the majority of anticancer agents derived from Basidiomycetes are able to stimulate lymphocytes, we describe the influence of Boletus edulis RNA on a human NK cell line (NK92). Our studies showed that a B. edulis RNA fraction was not toxic against NK92 cells. Furthermore, the tested fraction significantly stimulated NK92 cell proliferation and their cytotoxicity against tumor cells. We demonstrate here, to our knowledge for the first time, that B. edulis RNA enhances NK cell activity and possesses immunomodulatory potential.

  14. Natural mutations in a Staphylococcus aureus virulence regulator attenuate cytotoxicity but permit bacteremia and abscess formation

    Science.gov (United States)

    Das, Sudip; Lindemann, Claudia; Young, Bernadette C.; Muller, Julius; Österreich, Babett; Ternette, Nicola; Winkler, Ann-Cathrin; Paprotka, Kerstin; Reinhardt, Richard; Allen, Elizabeth; Flaxman, Amy; Yamaguchi, Yuko; Rollier, Christine S.; van Diemen, Pauline; Blättner, Sebastian; Remmele, Christian W.; Selle, Martina; Dittrich, Marcus; Müller, Tobias; Vogel, Jörg; Ohlsen, Knut; Crook, Derrick W.; Massey, Ruth; Wilson, Daniel J.; Rudel, Thomas; Wyllie, David H.; Fraunholz, Martin J.

    2016-01-01

    Staphylococcus aureus is a major bacterial pathogen, which causes severe blood and tissue infections that frequently emerge by autoinfection with asymptomatically carried nose and skin populations. However, recent studies report that bloodstream isolates differ systematically from those found in the nose and skin, exhibiting reduced toxicity toward leukocytes. In two patients, an attenuated toxicity bloodstream infection evolved from an asymptomatically carried high-toxicity nasal strain by loss-of-function mutations in the gene encoding the transcription factor repressor of surface proteins (rsp). Here, we report that rsp knockout mutants lead to global transcriptional and proteomic reprofiling, and they exhibit the greatest signal in a genome-wide screen for genes influencing S. aureus survival in human cells. This effect is likely to be mediated in part via SSR42, a long-noncoding RNA. We show that rsp controls SSR42 expression, is induced by hydrogen peroxide, and is required for normal cytotoxicity and hemolytic activity. Rsp inactivation in laboratory- and bacteremia-derived mutants attenuates toxin production, but up-regulates other immune subversion proteins and reduces lethality during experimental infection. Crucially, inactivation of rsp preserves bacterial dissemination, because it affects neither formation of deep abscesses in mice nor survival in human blood. Thus, we have identified a spontaneously evolving, attenuated-cytotoxicity, nonhemolytic S. aureus phenotype, controlled by a pleiotropic transcriptional regulator/noncoding RNA virulence regulatory system, capable of causing S. aureus bloodstream infections. Such a phenotype could promote deep infection with limited early clinical manifestations, raising concerns that bacterial evolution within the human body may contribute to severe infection. PMID:27185949

  15. Cytotoxicity, anti-angiogenic, apoptotic effects and transcript profiling of a naturally occurring naphthyl butenone, guieranone A

    Directory of Open Access Journals (Sweden)

    Kuete Victor

    2012-06-01

    Full Text Available Abstract Background Malignant diseases are responsible of approximately 13% of all deaths each year in the world. Natural products represent a valuable source for the development of novel anticancer drugs. The present study was aimed at evaluating the cytotoxicity of a naphtyl butanone isolated from the leaves of Guiera senegalensis, guieranone A (GA. Results The results indicated that GA was active on 91.67% of the 12 tested cancer cell lines, the IC50 values below 4 μg/ml being recorded on 83.33% of them. In addition, the IC50 values obtained on human lymphoblastic leukemia CCRF-CEM (0.73 μg/ml and its resistant subline CEM/ADR5000 (1.01 μg/ml and on lung adenocarcinoma A549 (0.72 μg/ml cell lines were closer or lower than that of doxorubicin. Interestingly, low cytotoxicity to normal hepatocyte, AML12 cell line was observed. GA showed anti-angiogenic activity with up to 51.9% inhibition of the growth of blood capillaries on the chorioallantoic membrane of quail embryo. Its also induced apotosis and cell cycle arrest. Ingenuity Pathway Analysis identified several pathways in CCRF-CEM cells and functional group of genes regulated upon GA treatment (P , the Cell Cycle: G2/M DNA Damage Checkpoint Regulation and ATM Signaling pathways being amongst the four most involved functional groups. Conclusion The overall results of this work provide evidence of the cytotoxic potential of GA and supportive data for its possible use in cancer chemotherapy.

  16. Anti-podocalyxin antibody exerts antitumor effects via antibody-dependent cellular cytotoxicity in mouse xenograft models of oral squamous cell carcinoma.

    Science.gov (United States)

    Itai, Shunsuke; Ohishi, Tomokazu; Kaneko, Mika K; Yamada, Shinji; Abe, Shinji; Nakamura, Takuro; Yanaka, Miyuki; Chang, Yao-Wen; Ohba, Shun-Ichi; Nishioka, Yasuhiko; Kawada, Manabu; Harada, Hiroyuki; Kato, Yukinari

    2018-04-27

    Podocalyxin (PODXL) overexpression is associated with progression, metastasis, and poor outcomes in cancers. We recently produced the novel anti-PODXL monoclonal antibody (mAb) PcMab-47 (IgG 1 , kappa). Herein, we engineered PcMab-47 into 47-mG 2a , a mouse IgG 2a -type mAb, to add antibody-dependent cellular cytotoxicity (ADCC). We further developed 47-mG 2a -f, a core fucose-deficient type of 47-mG 2a to augment its ADCC. Immunohistochemical analysis of oral cancer tissues using PcMab-47 and 47-mG 2a revealed that the latter stained oral squamous cell carcinoma (OSCC) cells in a cytoplasmic pattern at a much lower concentration. PcMab-47 and 47-mG 2a detected PODXL in 163/201 (81.1%) and in 197/201 (98.0%) OSCC samples, respectively. 47-mG 2a -f also detected PODXL in OSCCs at a similar frequency as 47-mG 2a . In vitro analysis revealed that both 47-mG 2a and 47-mG 2a -f exhibited strong complement-dependent cytotoxicity (CDC) against CHO/hPODXL cells. In contrast, 47-mG 2a -f exhibited much stronger ADCC than 47-mG 2a against OSCC cells, indicating that ADCC and CDC of those anti-PODXL mAbs depend on target cells. In vivo analysis revealed that both 47-mG 2a and 47-mG 2a -f exerted antitumor activity in CHO/hPODXL xenograft models at a dose of 100 μg or 500 μg/mouse/week administered twice. 47-mG 2a -f, but not 47-mG 2a , exerted antitumor activity in SAS and HSC-2 xenograft models at a dose of 100 μg/mouse/week administered three times. Although both 47-mG 2a and 47-mG 2a -f exerted antitumor activity in HSC-2 xenograft models at a dose of 500 μg/mouse/week administered twice, 47-mG 2a -f also showed higher antitumor activity than 47-mG 2a . These results suggested that a core fucose-deficient anti-PODXL mAb could be useful for antibody-based therapy against PODXL-expressing OSCCs.

  17. Cytotoxicity and cellular mechanisms involved in the toxicity of CdS quantum dots in hemocytes and gill cells of the mussel Mytilus galloprovincialis

    Energy Technology Data Exchange (ETDEWEB)

    Katsumiti, A. [CBET Research Group, Dept. Zoology and Animal Cell Biology, Faculty of Science and Technology and Research Centre for Experimental Marine Biology and Biotechnology PIE, University of the Basque Country UPV/EHU, Basque Country (Spain); Gilliland, D. [EU Commission–Joint Research Centre, Institute of Health and Consumer Protection, NSB Unit, Ispra (Italy); Arostegui, I. [Department of Applied Mathematics, Statistics and Operations Research, Faculty of Science and Technology, University of the Basque Country UPV/EHU, Leioa (Spain); Cajaraville, M.P., E-mail: mirenp.cajaraville@ehu.es [CBET Research Group, Dept. Zoology and Animal Cell Biology, Faculty of Science and Technology and Research Centre for Experimental Marine Biology and Biotechnology PIE, University of the Basque Country UPV/EHU, Basque Country (Spain)

    2014-08-15

    Highlights: • CdS QDs were cytotoxic for mussel hemocytes and gill cells in vitro. • Ionic Cd was the most toxic form, followed by CdS QDs and bulk CdS. • CdS QDs altered oxidative balance and caused DNA damage in mussel cells. • CdS QDs caused a particle-specific immunostimulation on phagocytosis of hemocytes. • Conceptual models for cellular handling and toxicity of CdS QDs are proposed. - Abstract: CdS quantum dots (QDs) show a great promise for treatment and diagnosis of cancer and for targeted drug delivery, due to their size-tunable fluorescence and ease of functionalization for tissue targeting. In spite of their advantages it is important to determine if CdS QDs can exert toxicity on biological systems. In the present work, cytotoxicity of CdS QDs (5 nm) at a wide range of concentrations (0.001–100 mg Cd/L) was screened using neutral red (NR) and thiazolyl blue tetrazolium bromide (MTT) assays in isolated hemocytes and gill cells of mussels (Mytilus galloprovincialis). The mechanisms of action of CdS QDs were assessed at sublethal concentrations (0.31–5 mg Cd/L) in the same cell types through a series of functional in vitro assays: production of reactive oxygen species (ROS), catalase (CAT) activity, DNA damage, lysosomal acid phosphatase (AcP) activity, multixenobiotic resistance (MXR) transport activity, Na-K-ATPase activity (only in gill cells) and phagocytic activity and damage to actin cytoskeleton (only in hemocytes). Exposures to CdS QDs lasted for 24 h and were performed in parallel with exposures to bulk CdS and ionic Cd. Ionic Cd was the most toxic form to both cell types, followed by CdS QDs and bulk CdS. ROS production, DNA damage, AcP activity and MXR transport were significantly increased in both cell types exposed to the 3 forms of Cd. CAT activity increased in hemocytes exposed to the three forms of Cd while in gill cells only in those exposed to ionic Cd. No effects were found on hemocytes cytoskeleton integrity. Effects on

  18. Different cellular responses evoked by natural and stoichiometric synthetic chrysotile asbestos

    International Nuclear Information System (INIS)

    Gazzano, Elena; Foresti, Elisabetta; Lesci, Isidoro Giorgio; Tomatis, Maura; Riganti, Chiara; Fubini, Bice; Roveri, Norberto; Ghigo, Dario

    2005-01-01

    The carcinogenic potency of asbestos, including chrysotile, is well established. Several physico-chemical features of the fibers appear implied, such as fibrous habit, size, crystallinity, morphology, and surface active metal ions, where free radical generation may take place. In contrast to other asbestos forms, iron is not a stoichiometric component of chrysotile, but is only present together with other extraneous ions as a magnesium- and silicon-replacing contaminant. To determine the role played by contaminating ions and morphological features of the fibers, a stoichiometric chrysotile with constant structure and morphology was synthesized in hydrothermal conditions. Free radical generation and the effects of these fibers on human lung epithelial A549 cells have been compared to that elicited by a well known toxic natural chrysotile (UICC A, from Rhodesia). After a 24-h incubation, the natural, but not the synthetic, form exerted a cytotoxic effect, detected as leakage of lactate dehydrogenase. Homolytic rupture of a C-H bond and lipoperoxidation in A549 cells took place in the presence of the natural, but not of the synthetic, chrysotile. Antioxidant systems were also affected differently. The pentose phosphate pathway and its regulatory enzyme glucose 6-phosphate dehydrogenase were markedly inhibited only by the natural specimen, which also caused a depletion of intracellular reduced glutathione in A549 cells. These results suggest that metal ions, fiber size and state of the surface play a crucial role in the oxidative stress caused by chrysotile asbestos. Stoichiometric synthetic fibers may thus be proposed as a reference standard (negative control) for toxicological studies

  19. 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.

    Science.gov (United States)

    Lawley, P D; Brookes, P

    1968-09-01

    1. A quantitative study was made of the relationship between survival of colony-forming ability in Escherichia coli strains B/r and B(s-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 B(s-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

  20. Immunization with Clinical HIV-1 Env Proteins Induces Broad Antibody Dependent Cellular Cytotoxicity-Mediating Antibodies in a Rabbit Vaccination Model.

    Science.gov (United States)

    Karlsson, Ingrid; Borggren, Marie; Jensen, Sanne Skov; Heyndrickx, Leo; Stewart-Jones, Guillaume; Scarlatti, Gabriella; Fomsgaard, Anders

    2017-11-17

    The induction of both neutralizing antibodies and non-neutralizing antibodies with effector functions, for example, antibody-dependent cellular cytotoxicity (ADCC), is desired in the search for effective vaccines against HIV-1. In the pursuit of novel immunogens capable of inducing an efficient antibody response, rabbits were immunized with selected antigens using different prime-boost strategies. We immunized 35 different groups of rabbits with Env antigens from clinical HIV-1 subtypes A and B, including immunization with DNA alone, protein alone, and DNA prime with protein boost. The rabbit sera were screened for ADCC activity using a GranToxiLux-based assay with human peripheral blood mononuclear cells as effector cells and CEM.NKR CCR5 cells coated with HIV-1 envelope as target cells. The groups with the highest ADCC activity were further characterized for cross-reactivity between HIV-1 subtypes. The immunogen inducing the most potent and broadest ADCC response was a trimeric gp140. The ADCC activity was highest against the HIV-1 subtype corresponding to the immunogen. The ADCC activity did not necessarily reflect neutralizing activity in the pseudovirus-TZMbl assay, but there was an overall correlation between the two antiviral activities. We present a rabbit vaccination model and an assay suitable for screening HIV-1 vaccine candidates for the induction of ADCC-mediating antibodies in addition to neutralizing antibodies. The antigens and/or immunization strategies capable of inducing antibodies with ADCC activity did not necessarily induce neutralizing activity and vice versa. Nevertheless, we identified vaccine candidates that were able to concurrently induce both types of responses and that had ADCC activity that was cross-reactive between different subtypes. When searching for an effective vaccine candidate, it is important to evaluate the antibody response using a model and an assay measuring the desired function.

  1. Targeting Multiple Tumors Using T-Cells Engineered to Express a Natural Cytotoxicity Receptor 2-Based Chimeric Receptor

    Directory of Open Access Journals (Sweden)

    Vasyl Eisenberg

    2017-09-01

    Full Text Available Recent developments in cancer treatment are demonstrating the increasing and powerful potential of immunotherapeutic strategies. In this regard, the adoptive transfer of tumor-specific T-lymphocytes approaches can lead to tumor regression in cancer patients. More recently, the use of T-cells genetically engineered to express cancer-specific receptors such as the anti-CD19 chimeric antigen receptor (CAR continues to show promise for the treatment of hematological malignancies. Still, there is a crucial need to develop efficient CAR-T cell approaches for the treatment of solid tumors. It has been shown that other lymphocytes such as natural killer (NK cells can demonstrate potent antitumor function—nonetheless, their use in immunotherapy is rather limited due to difficulties in expanding these cells to therapeutically relevant numbers and to suppression by endogenous inhibitory mechanisms. Cancer recognition by NK cells is partly mediated by molecules termed natural cytotoxicity receptors (NCRs. In the present study, we hypothesize that it is possible to endow T-cells with an NK recognition pattern, providing them with a mean to recognize tumor cells, in a non-MHC restricted way. To test this, we genetically modified human T-cells with different chimeric receptors based on the human NCR2 molecule and then assessed their antitumor activity in vitro and in vivo. Our results show that expression in primary lymphocytes of an NCR2-derived CAR, termed s4428z, confers T-cells with the ability to specifically recognize heterogeneous tumors and to mediate tumor cytotoxicity in a mouse model. This study demonstrates the benefit of combining tumor recognition capability of NK cells with T cell effectiveness to improve cancer immunotherapy.

  2. Human CD1d-Restricted Natural Killer T (NKT) Cell Cytotoxicity Against Myeloid Cells

    National Research Council Canada - National Science Library

    Chen, Xiuxu; Gumperz, Jenny E

    2006-01-01

    CD1d-restricted natural killer T cells (NKT cells) are a unique subpopulation of T lymphocytes that have been shown to be able to promote potent anti-tumor responses in a number of different murine (mouse...

  3. The Murine Natural Cytotoxic Receptor NKp46/NCR1 Controls TRAIL Protein Expression in NK Cells and ILC1s

    Directory of Open Access Journals (Sweden)

    Sam Sheppard

    2018-03-01

    Full Text Available Summary: TRAIL is an apoptosis-inducing ligand constitutively expressed on liver-resident type 1 innate lymphoid cells (ILC1s and a subset of natural killer (NK cells, where it contributes to NK cell anti-tumor, anti-viral, and immunoregulatory functions. However, the intrinsic pathways involved in TRAIL expression in ILCs remain unclear. Here, we demonstrate that the murine natural cytotoxic receptor mNKp46/NCR1, expressed on ILC1s and NK cells, controls TRAIL protein expression. Using NKp46-deficient mice, we show that ILC1s lack constitutive expression of TRAIL protein and that NK cells activated in vitro and in vivo fail to upregulate cell surface TRAIL in the absence of NKp46. We show that NKp46 regulates TRAIL expression in a dose-dependent manner and that the reintroduction of NKp46 in mature NK cells deficient for NKp46 is sufficient to restore TRAIL surface expression. These studies uncover a link between NKp46 and TRAIL expression in ILCs with potential implications in pathologies involving NKp46-expressing cells. : Sheppard et al. find that mice deficient in the activating receptor NCR1/NKp46 (Ncr1−/− fail to express the apoptosis-inducing ligand TRAIL at the surface of group 1 innate lymphoid cells (ILC1s. Keywords: NK cell, natural killer cell, NKp46, ILC1, TRAIL, IL-15, IL-2

  4. Direct anti-atherosclerotic therapy; development of natural anti-atherosclerotic drugs preventing cellular cholesterol retention.

    Science.gov (United States)

    Orekhov, Alexander N

    2013-01-01

    The results of numerous clinical trials with statins and other drugs have demonstrated the principal possibility of the prevention and regression of atherosclerosis by pharmacotherapy. This review describes the use of cultured human arterial cells for the mass screening of anti-atherosclerotic substances, the investigation of the mechanisms responsible for their atherosclerosis-related effects, and the optimization of anti-atherosclerotic and anti-atherogenic drug and dietary therapies. Natural products can be considered promising drugs for anti-atherosclerotic therapy. Our basic studies have shown that cellular lipidosis is the principal event in the genesis of atherosclerotic lesions. Using cellular models and natural products, we have developed an approach to prevent lipid accumulation in arterial cells. Based on our knowledge of atherosclerosis, we developed drugs that possess direct anti-atherosclerotic activity. Two-year treatment with allicor (garlic powder) has a direct anti-atherosclerotic effect on carotid atherosclerosis in asymptomatic men. Inflaminat (calendula, elder, and violet), which possesses anti-cytokine activity, has been shown to cause the regression of carotid atherosclerosis following the treatment of asymptomatic men for one year. The phytoestrogen-rich drug karinat (garlic powder, extract of grape seeds, green tea leaves, hop cones, β-carotene, α-tocopherol, and ascorbic acid) prevents the development of carotid atherosclerosis in postmenopausal women. Thus, our basic findings were successfully translated into clinical practice. Because of this translation, a novel approach to antiatherosclerotic therapy was developed. Our clinical trial confirmed the efficacy of both the novel approach and the novel drugs.

  5. Degradation of natural organic matter by UV/chlorine oxidation: Molecular decomposition, formation of oxidation byproducts and cytotoxicity.

    Science.gov (United States)

    Wang, Wen-Long; Zhang, Xue; Wu, Qian-Yuan; Du, Ye; Hu, Hong-Ying

    2017-11-01

    The degradation of natural organic matters (NOMs) by the combination of UV and chlorine (UV/chlorine) was investigated in this study. UV/chlorine oxidation can effectively degrade NOMs, with the degradation of chromophores (∼80%) and fluorophores (76.4-80.8%) being more efficient than that of DOC (15.1-18.6%). This effect was attributed to the chromophores and fluorophores (double bonds, aromatic groups and phenolic groups) being preferentially degraded by UV/chlorine oxidation, particularly reactive groups with high electron donating capacity. Radical species •OH and •Cl were generated during UV/chlorine oxidation, with the contribution of •OH 1.4 times as high as that of •Cl. The degradation kinetics of different molecular weight (MW) fractions suggests that UV/chlorine oxidation degrades high MW fractions into low MW fractions, with the degradation rates of high MW fractions (>3000 Da) 4.5 times of those of medium MW fractions (1000-3000 Da). In comparison with chlorination alone, UV/chlorine oxidation did not increase the formation (30 min) and formation potential (24 h) of trihalomethanes, but instead promoted the formation and formation potential of haloacetic acids and chloral hydrate. Adsorbable organic halogen (AOX) formed from UV/chlorine oxidation of NOM were 0.8 times higher than those formed from chlorination. Cytotoxicity studies indicated that the cytotoxicity of NOM increased after both chlorination and UV/chlorine oxidation, which may be due to the formation of AOX. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Structure-cytotoxicity relationships of a series of natural and semi-synthetic simple coumarins as assessed in two human tumour cell lines

    NARCIS (Netherlands)

    Kolodziej, H; Kayser, O; Woerdenbag, HJ; vanUden, W; Pras, N

    1997-01-01

    The cytotoxicity of 22 natural and semi-synthetic simple coumarins was evaluated in GLC(4), a human small cell lung carcinoma cell line, and in COLO 320, a human colorectal cancer cell line, using the microculture tetrazolium (MTT) assay. With IC50 values > 100 mu M, following a continuous (96h)

  7. The pharmaceutical exploration of cold water ascidians from the Netherlands : a possible source of new cytotoxic natural products

    NARCIS (Netherlands)

    Koulman, A; Pruijn, L.M C; Sandstra, T.C A; Woerdenbag, H.J.; Pras, N.

    1999-01-01

    Six ascidian species from the Dutch North Sea coast were screened for cytotoxic activity, Freeze-dried biological material was extracted with solvents of different polarity followed by determination of the cytotoxicity. The most active extracts were further separated using different chromatographic

  8. Special Issue: Redox Active Natural Products and Their Interaction with Cellular Signalling Pathways

    Directory of Open Access Journals (Sweden)

    Claus Jacob

    2014-11-01

    Full Text Available During the last decade, research into natural products has experienced a certain renaissance. The urgent need for more and more effective antibiotics in medicine, the demand for ecologically friendly plant protectants in agriculture, “natural” cosmetics and the issue of a sustainable and healthy nutrition in an ageing society have fuelled research into Nature’s treasure chest of “green gold”. Here, redox active secondary metabolites from plants, fungi, bacteria and other (micro-organisms often have been at the forefront of the most interesting developments. These agents provide powerful means to interfere with many, probably most cellular signaling pathways in humans, animals and lower organisms, and therefore can be used to protect, i.e., in form of antioxidants, and to frighten off or even kill, i.e., in form of repellants, antibiotics, fungicides and selective, often catalytic “sensor/effector” anticancer agents. Interestingly, whilst natural product research dates back many decades, in some cases even centuries, and compounds such as allicin and various flavonoids have been investigated thoroughly in the past, it has only recently become possible to investigate their precise interactions and mode(s of action inside living cells. Here, fluorescent staining and labelling on the one side, and appropriate detection, either qualitatively under the microscope or quantitatively in flow cytometers and plate readers, on the other, enable researchers to obtain the various pieces of information necessary to construct a fairly complete puzzle of how such compounds act and interact in living cells. Complemented by the more traditional activity assays and Western Blots, and increasingly joined by techniques such as proteomics, chemogenetic screening and mRNA profiling, these cell based bioanalytical techniques form a powerful platform for “intracellular diagnostics”. In the case of redox active compounds, especially of Reactive Sulfur

  9. Antigen Presenting Cells and Stromal Cells Trigger Human Natural Killer Lymphocytes to Autoreactivity: Evidence for the Involvement of Natural Cytotoxicity Receptors (NCR and NKG2D

    Directory of Open Access Journals (Sweden)

    Alessandro Poggi

    2006-01-01

    Full Text Available Human natural killer (NK lymphocytes should not damage autologous cells due to the engagement of inhibitory receptor superfamily (IRS members by HLA-I. Nevertheless, NK cells kill self cells expressing low levels or lacking HLA-I, as it may occur during viral infections (missing-self hypothesis. Herein, we show that human NK cells can be activated upon binding with self antigen presenting cells or stromal cells despite the expression of HLA-I. Indeed, NK cells can kill and produce pro-inflammatory and regulating cytokines as IFN-γ, TNF-α and IL10 during interaction with autologous dendritic cells or bone marrow stromal cells or skin fibroblasts. The killing of antigen presenting and stromal cells is dependent on LFA1/ICAM1 interaction. Further, the natural cytotoxicity receptors (NCR NKp30 and NKp46 are responsible for the delivery of lethal hit to DC, whereas NKG2D activating receptor, the ligand of the MHC-related molecule MIC-A and the UL16 binding protein, is involved in stromal cell killing. These findings indicate that different activating receptors are involved in cell to self cell interaction. Finally, NK cells can revert the veto effect of stromal cells on mixed lymphocyte reaction further supporting the idea that NK cells may alter the interaction between T lymphocytes and microenvironment leading to autoreactivity.

  10. The cellular distribution of extracellular superoxide dismutase in macrophages is altered by cellular activation but unaffected by the natural occurring R213G substitution

    DEFF Research Database (Denmark)

    Gottfredsen, Randi Heidemann; Goldstrohm, David; Hartney, John

    2014-01-01

    and associated with the cell surface via the extracellular matrix (ECM)-binding region. Upon cellular activation induced by lipopolysaccharide, EC-SOD is relocated and detected both in the cell culture medium and in lipid raft structures. Although the secreted material presented a significantly reduced ligand......-binding capacity, this could not be correlated to proteolytic removal of the ECM-binding region, because the integrity of the material recovered from the medium was comparable to that of the cell surface-associated protein. The naturally occurring R213G amino acid substitution located in the ECM-binding region...

  11. Monte Carlo N-Particle (MCNP) Modeling of the Cellular Dosimetry of 64Cu: Comparison with MIRDcell S Values and Implications for Studies of Its Cytotoxic Effects.

    Science.gov (United States)

    Cai, Zhongli; Kwon, Yongkyu Luke; Reilly, Raymond M

    2017-02-01

    64 Cu emits positrons as well as β - particles and Auger and internal conversion electrons useful for radiotherapy. Our objective was to model the cellular dosimetry of 64 Cu under different geometries commonly used to study the cytotoxic effects of 64 Cu. Monte Carlo N-Particle (MCNP) was used to simulate the transport of all particles emitted by 64 Cu from the cell surface (CS), cytoplasm (Cy), or nucleus (N) of a single cell; monolayer in a well (radius = 0.32-1.74 cm); or a sphere (radius = 50-6,000 μm) of cells to calculate S values. The radius of the cell and N ranged from 5 to 12 μm and 2 to 11 μm, respectively. S values were obtained by MIRDcell for comparison. MCF7/HER2-18 cells were exposed in vitro to 64 Cu-labeled trastuzumab. The subcellular distribution of 64 Cu was measured by cell fractionation. The surviving fraction was determined in a clonogenic assay. The relative differences of MCNP versus MIRDcell self-dose S values (S self ) for 64 Cu ranged from -0.2% to 3.6% for N to N (S N←N ), 2.3% to 8.6% for Cy to N (S N←Cy ), and -12.0% to 7.3% for CS to N (S N←CS ). The relative differences of MCNP versus MIRDcell cross-dose S values were 25.8%-30.6% for a monolayer and 30%-34% for a sphere, respectively. The ratios of S N←N versus S N←Cy and S N←Cy versus S N←CS decreased with increasing ratio of the N of the cell versus radius of the cell and the size of the monolayer or sphere. The surviving fraction of MCF7 /: HER2-18 cells treated with 64 Cu-labeled trastuzumab (0.016-0.368 MBq/μg, 67 nM) for 18 h versus the absorbed dose followed a linear survival curve with α = 0.51 ± 0.05 Gy -1 and R 2 = 0.8838. This is significantly different from the linear quadratic survival curve of MCF7 /: HER2-18 cells exposed to γ-rays. MCNP- and MIRDcell-calculated S values agreed well. 64 Cu in the N increases the dose to the N in isolated single cells but has less effect in a cell monolayer or small cluster of cells simulating a micrometastasis

  12. Activation of human natural killer cells by the soluble form of cellular prion protein

    Energy Technology Data Exchange (ETDEWEB)

    Seong, Yeon-Jae [Laboratory of Immunology and Infectious Diseases, Graduate School of Medical Science and Engineering, KAIST, Daejeon (Korea, Republic of); Hafis Clinic, Seoul (Korea, Republic of); Sung, Pil Soo; Jang, Young-Soon; Choi, Young Joon [Laboratory of Immunology and Infectious Diseases, Graduate School of Medical Science and Engineering, KAIST, Daejeon (Korea, Republic of); Park, Bum-Chan [Aging Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon (Korea, Republic of); Park, Su-Hyung [Laboratory of Translational Immunology and Vaccinology, Graduate School of Medical Science and Engineering, KAIST, Daejeon (Korea, Republic of); Park, Young Woo [Aging Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon (Korea, Republic of); Shin, Eui-Cheol, E-mail: ecshin@kaist.ac.kr [Laboratory of Immunology and Infectious Diseases, Graduate School of Medical Science and Engineering, KAIST, Daejeon (Korea, Republic of)

    2015-08-21

    Cellular prion protein (PrP{sup C}) is widely expressed in various cell types, including cells of the immune system. However, the specific roles of PrP{sup C} in the immune system have not been clearly elucidated. In the present study, we investigated the effects of a soluble form of recombinant PrP{sup C} protein on human natural killer (NK) cells. Recombinant soluble PrP{sup C} protein was generated by fusion of human PrP{sup C} with the Fc portion of human IgG{sub 1} (PrP{sup C}-Fc). PrP{sup C}-Fc binds to the surface of human NK cells, particularly to CD56{sup dim} NK cells. PrP{sup C}-Fc induced the production of cytokines and chemokines and the degranulation of granzyme B from NK cells. In addition, PrP{sup C}-Fc facilitated the IL-15-induced proliferation of NK cells. PrP{sup C}-Fc induced phosphorylation of ERK-1/2 and JNK in NK cells, and inhibitors of the ERK or the JNK pathways abrogated PrP{sup C}-Fc-induced cytokine production in NK cells. In conclusion, the soluble form of recombinant PrP{sup C}-Fc protein activates human NK cells via the ERK and JNK signaling pathways. - Highlights: • Recombinant soluble PrP{sup C} (PrP{sup C}-Fc) was generated by fusion of human PrP{sup C} with IgG1 Fc portion. • PrP{sup C}-Fc protein induces the production of cytokines and degranulation from human NK cells. • PrP{sup C}-Fc protein enhances the IL-15-induced proliferation of human NK cells. • PrP{sup C}-Fc protein activates human NK cells via the ERK and JNK signaling pathways.

  13. Activation of human natural killer cells by the soluble form of cellular prion protein

    International Nuclear Information System (INIS)

    Seong, Yeon-Jae; Sung, Pil Soo; Jang, Young-Soon; Choi, Young Joon; Park, Bum-Chan; Park, Su-Hyung; Park, Young Woo; Shin, Eui-Cheol

    2015-01-01

    Cellular prion protein (PrP C ) is widely expressed in various cell types, including cells of the immune system. However, the specific roles of PrP C in the immune system have not been clearly elucidated. In the present study, we investigated the effects of a soluble form of recombinant PrP C protein on human natural killer (NK) cells. Recombinant soluble PrP C protein was generated by fusion of human PrP C with the Fc portion of human IgG 1 (PrP C -Fc). PrP C -Fc binds to the surface of human NK cells, particularly to CD56 dim NK cells. PrP C -Fc induced the production of cytokines and chemokines and the degranulation of granzyme B from NK cells. In addition, PrP C -Fc facilitated the IL-15-induced proliferation of NK cells. PrP C -Fc induced phosphorylation of ERK-1/2 and JNK in NK cells, and inhibitors of the ERK or the JNK pathways abrogated PrP C -Fc-induced cytokine production in NK cells. In conclusion, the soluble form of recombinant PrP C -Fc protein activates human NK cells via the ERK and JNK signaling pathways. - Highlights: • Recombinant soluble PrP C (PrP C -Fc) was generated by fusion of human PrP C with IgG1 Fc portion. • PrP C -Fc protein induces the production of cytokines and degranulation from human NK cells. • PrP C -Fc protein enhances the IL-15-induced proliferation of human NK cells. • PrP C -Fc protein activates human NK cells via the ERK and JNK signaling pathways

  14. Dynamic changes of cytotoxic T lymphocytes (CTLs, natural killer (NK cells, and natural killer T (NKT cells in patients with acute hepatitis B infection

    Directory of Open Access Journals (Sweden)

    Liu Bo

    2011-05-01

    Full Text Available Abstract Background The goal of this study is to observe changes in HBcAg-specific cytotoxic T lymphocytes (CTLs, natural killer (NK and natural killer T (NKT cells from peripheral blood and to relate such changes on viral clearance and liver injury in patients with acute hepatitis B (AHB. Methods Dynamic profiles on the frequency of HLA-A0201-restricted HBcAg18-27 pentamer complex (MHC-Pentamer-specific CTLs and lymphocyte subsets in AHB patients were analyzed in addition to liver function tests, HBV serological markers, and HBV DNA levels. ELISPOT was used to detect interferon-gamma (INF-γ secretion in specific CTLs stimulated with known T cell epitope peptides associated with HBV surface protein, polymerase, and core protein. Results HBV-specific CTL frequencies in AHB patients were much higher than in patients with chronic hepatitis B (CHB (p +CD8+ T cell numbers in AHB patients was more than observed in the healthy control group from the first to the fourth week after admission (p = 0.008 and 0.01, respectively; the number of CD3+CD8+ T cells and frequency of HBcAg18-27-specific CTLs in AHB patients reached peak levels at the second week after admission. NK and NKT cell numbers were negatively correlated with the frequency of HBcAg-specific CTLs (r = -0.266, p = 0.05. Conclusions Patients with AHB possess a higher frequency of HBcAg-specific CTLs than CHB patients. The frequency of specific CTLs in AHB patients is correlated with HBeAg clearance indicating that HBV-specific CTLs play an important role in viral clearance and the self-limited process of the disease. Furthermore, NK and NKT cells are likely involved in the early, non-specific immune response to clear the virus.

  15. LC–MS characterization, anti-kinetoplastide and cytotoxic activities of natural products from Eugenia jambolana Lam. and Eugenia uniflora

    Directory of Open Access Journals (Sweden)

    Celestina Elba Sobral de Souza

    2017-09-01

    Conclusions: The species E. jambolana and E. uniflora presented antiparasitic activity against all tested parasite strains, indicating that these species can serve as an alternative therapy as they were efficient in the tests performed. The E. uniflora extract and the E. jambolana flavonoid fraction presented a low cytotoxicity, opening the floor for new biological studies.

  16. Antibody-dependent cellular cytotoxicity (ADCC) activity of a novel anti-PD-L1 antibody avelumab (MSB0010718C) on human tumor cells

    OpenAIRE

    Boyerinas, Benjamin; Jochems, Caroline; Fantini, Massimo; Heery, Christopher R.; Gulley, James L.; Tsang, Kwong Yok; Schlom, Jeffrey

    2015-01-01

    Several anti-PD1/PD-L1 monoclonal antibodies (MAb) are currently providing evidence of clinical benefit in subsets of cancer patients. The mode of action of these MAbs is to inhibit PD1 on immune cells interacting with PD-L1 on tumor cells. These MAbs are either designed or engineered to eliminate antibody-dependent cell-mediated cytotoxicity (ADCC), which, however, has been implicated as an important mechanism in several highly effective MAb-mediated cancer therapies. A fully human anti-PD-L...

  17. Cellular Uptake and Photo-Cytotoxicity of a Gadolinium(III-DOTA-Naphthalimide Complex “Clicked” to a Lipidated Tat Peptide

    Directory of Open Access Journals (Sweden)

    William I. O’Malley

    2016-02-01

    Full Text Available 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.

  18. Cellular uptake, nuclear localization and cytotoxicity of 125I-labelled DNA minor groove binding ligands in K562, human erythroleukaemia cells

    International Nuclear Information System (INIS)

    Karagiannis, T.C.; Lobachevsky, P.N.; Martin, R.F.

    2000-01-01

    Full text: Iodine-125 decays by orbital electron capture and internal conversion resulting in the emission of numerous Auger electrons which produce a highly localised radiochemical damage in the immediate vicinity of the site of decay. Given the requirement to deliver 125 I to the nuclear DNA, a minor groove binding bibenzimidazole, 125 I-iodoHoechst 33258 was investigated. It has been noted that this analogue may be prone to de-iodination in vitro and in vivo, given the presence of an orthoiodophenol moiety which is analogous to that in thyroxins. Therefore, an 125 I -iodoHoechst analogue without the hydroxyl group was also studied. The 125 I -iodoHoechst 33258 analogue was prepared by direct iodination of Hoechst 33258 and 125 I iodoHoechst was prepared by demetallation of a trimethylstannyl precursor. DNA binding studies indicated that both iodo-analogues bind to calf thymus DNA, K D = 89 ± 30nM, n = 0.018 bp - 1 for iodoHoechst 33258 and K D = 121 ± 31nM, n = 0.024 bp -1 for iodoHoechst. Similarly, nuclear localization following incubation with 5μM of either ligand at 37 deg C was observed in K562 cells by fluorescence microscopy. Flow cytometry was used to investigate the kinetics of drug uptake and efflux in K562 cells. The results indicated that when 10 6 cells were incubated with 5μM ligand at 37 deg C, the uptake reached a plateau at approximately 43 minutes for iodoHoechst 33258 and approximately 52 minutes for iodoHoechst. Ligand efflux results indicated two-phase kinetics. The initial phase which involves 50-60% of drug was characterised by a half-life time (t 1/2 ) of 55.4 minutes for efflux of iodoHoechst 33258 and a t 1/2 of 10.3 minutes for efflux of iodoHoechst, at 37 deg C. Furthermore, the results suggested that the DNA binding sites in a 10 6 cell/ml suspension were saturated by incubation with 3μM iodoHoechst 33258 and 5μM iodoHoechst. In the initial cytotoxicity experiments using 125 I-iodoHoechst 33258, K562 cells were incubated for 1

  19. NK-cell-dependent killing of colon carcinoma cells is mediated by natural cytotoxicity receptors (NCRs) and stimulated by parvovirus infection of target cells

    International Nuclear Information System (INIS)

    Bhat, Rauf; Rommelaere, Jean

    2013-01-01

    Investigating how the immune system functions during malignancies is crucial to developing novel therapeutic strategies. Natural killer (NK) cells, an important component of the innate immune system, play a vital role in immune defense against tumors and virus-infected cells. The poor survival rate in colon cancer makes it particularly important to develop novel therapeutic strategies. Oncolytic viruses, in addition to lysing tumor cells, may have the potential to augment antitumor immune responses. In the present study, we investigate the role of NK cells and how parvovirus H-1PV can modulate NK-cell mediated immune responses against colon carcinoma. Human NK cells were isolated from the blood of healthy donors. The cytotoxicity and antibody-mediated inhibition of NK cells were measured in chromium release assays. Phenotypic assessment of colon cancer and dendritic cells was done by FACS. The statistical significance of the results was calculated with Student’s t test (*p <0.05; **, p < 0.01; ***, p < 0.001). We show that IL-2-activated human NK cells can effectively kill colon carcinoma cells. Killing of colon carcinoma cells by NK cells was further enhanced upon infection of the former cells with parvovirus H-1PV. H-1PV has potent oncolytic activity against various tumors, yet its direct killing effect on colon carcinoma cells is limited. The cytotoxicity of NK cells towards colon carcinoma cells, both mock- and H-1PV-infected, was found to be mostly mediated by a combination of natural cytotoxicity receptors (NCRs), namely NKp30, 44, and 46. Colon carcinoma cells displayed low to moderate expression of NK cell ligands, and this expression was modulated upon H-1PV infection. Lysates of H-1PV-infected colon carcinoma cells were found to increase MHC class II expression on dendritic cells. Altogether, these data suggest that IL-2-activated NK cells actively kill colon carcinoma cells and that this killing is mediated by several natural cytotoxicity receptors

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

    Directory of Open Access Journals (Sweden)

    Cavazzoni Andrea

    2012-12-01

    Full Text Available Abstract 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.

  1. Multi-cellular natural killer (NK) cell clusters enhance NK cell activation through localizing IL-2 within the cluster

    Science.gov (United States)

    Kim, Miju; Kim, Tae-Jin; Kim, Hye Mi; Doh, Junsang; Lee, Kyung-Mi

    2017-01-01

    Multi-cellular cluster formation of natural killer (NK) cells occurs during in vivo priming and potentiates their activation to IL-2. However, the precise mechanism underlying this synergy within NK cell clusters remains unclear. We employed lymphocyte-laden microwell technologies to modulate contact-mediated multi-cellular interactions among activating NK cells and to quantitatively assess the molecular events occurring in multi-cellular clusters of NK cells. NK cells in social microwells, which allow cell-to-cell contact, exhibited significantly higher levels of IL-2 receptor (IL-2R) signaling compared with those in lonesome microwells, which prevent intercellular contact. Further, CD25, an IL-2R α chain, and lytic granules of NK cells in social microwells were polarized toward MTOC. Live cell imaging of lytic granules revealed their dynamic and prolonged polarization toward neighboring NK cells without degranulation. These results suggest that IL-2 bound on CD25 of one NK cells triggered IL-2 signaling of neighboring NK cells. These results were further corroborated by findings that CD25-KO NK cells exhibited lower proliferation than WT NK cells, and when mixed with WT NK cells, underwent significantly higher level of proliferation. These data highlights the existence of IL-2 trans-presentation between NK cells in the local microenvironment where the availability of IL-2 is limited.

  2. Cellular responses to modified Plasmodium falciparum MSP119 antigens in individuals previously exposed to natural malaria infection

    Directory of Open Access Journals (Sweden)

    Awobode Henrietta O

    2009-11-01

    Full Text Available Abstract Background MSP1 processing-inhibitory antibodies bind to epitopes on the 19 kDa C-terminal region of the Plasmodium falciparum merozoite surface protein 1 (MSP119, inhibiting erythrocyte invasion. Blocking antibodies also bind to this antigen but prevent inhibitory antibodies binding, allowing invasion to proceed. Recombinant MSP119 had been modified previously to allow inhibitory but not blocking antibodies to continue to bind. Immunization with these modified proteins, therefore, has the potential to induce more effective protective antibodies. However, it was unclear whether the modification of MSP119 would affect critical T-cell responses to epitopes in this antigen. Methods The cellular responses to wild-type MSP119 and a panel of modified MSP119 antigens were measured using an in-vitro assay for two groups of individuals: the first were malaria-naïve and the second had been naturally exposed to Plasmodium falciparum infection. The cellular responses to the modified proteins were examined using cells from malaria-exposed infants and adults. Results Interestingly, stimulation indices (SI for responses induced by some of the modified proteins were at least two-fold higher than those elicited by the wild-type MSP119. A protein with four amino acid substitutions (Glu27→Tyr, Leu31→Arg, Tyr34→Ser and Glu43→Leu had the highest stimulation index (SI up to 360 and induced large responses in 64% of the samples that had significant cellular responses to the modified proteins. Conclusion This study suggests that specific MSP119 variants that have been engineered to improve their antigenicity for inhibitory antibodies, retain T-cell epitopes and the ability to induce cellular responses. These proteins are candidates for the development of MSP1-based malaria vaccines.

  3. Antibody-Dependent Cellular Cytotoxicity Activity of a Novel Anti-PD-L1 Antibody Avelumab (MSB0010718C) on Human Tumor Cells.

    Science.gov (United States)

    Boyerinas, Benjamin; Jochems, Caroline; Fantini, Massimo; Heery, Christopher R; Gulley, James L; Tsang, Kwong Yok; Schlom, Jeffrey

    2015-10-01

    Several anti-PD-1/PD-L1 monoclonal antibodies (mAb) are currently providing evidence of clinical benefit in subsets of cancer patients. The mode of action of these mAbs is to inhibit PD-1 on immune cells interacting with PD-L1 on tumor cells. These mAbs are either designed or engineered to eliminate antibody-dependent cell-mediated cytotoxicity (ADCC), which, however, has been implicated as an important mechanism in several highly effective mAb-mediated cancer therapies. A fully human anti-PD-L1 mAb would potentially be able to block PD-1/PD-L1 interactions and also mediate the ADCC lysis of tumor cells. MSB0010718C (designated avelumab) is a fully human IgG1 anti-PD-L1 mAb. The studies reported here demonstrate (i) the ability of avelumab to lyse a range of human tumor cells in the presence of PBMC or NK effectors; (ii) IFNγ can enhance tumor cell PD-L1 expression and, in some cases, enhance ADCC tumor cell lysis; (iii) purified NK cells are potent effectors for avelumab; (iv) similar levels of avelumab-mediated ADCC lysis of tumor cells are seen using purified NK as effectors from either healthy donors or cancer patients; (v) very low levels of avelumab-mediated lysis are seen using whole PBMCs as targets; this finding complements results seen in analyses of PBMC subsets of patients receiving avelumab; and (vi) the addition of IL12 to NK cells greatly enhances avelumab-mediated ADCC. These studies thus provide an additional mode of action for an anti-PD-L1 mAb and support the rationale for further studies to enhance avelumab-mediated ADCC activity. ©2015 American Association for Cancer Research.

  4. Antibody-dependent cellular cytotoxicity (ADCC) activity of a novel anti-PD-L1 antibody avelumab (MSB0010718C) on human tumor cells

    Science.gov (United States)

    Fantini, Massimo; Heery, Christopher R.; Gulley, James L.; Tsang, Kwong Yok; Schlom, Jeffrey

    2015-01-01

    Several anti-PD1/PD-L1 monoclonal antibodies (MAb) are currently providing evidence of clinical benefit in subsets of cancer patients. The mode of action of these MAbs is to inhibit PD1 on immune cells interacting with PD-L1 on tumor cells. These MAbs are either designed or engineered to eliminate antibody-dependent cell-mediated cytotoxicity (ADCC), which, however, has been implicated as an important mechanism in several highly effective MAb-mediated cancer therapies. A fully human anti-PD-L1 MAb would potentially be able to block PD-L1/PD1 interactions and also mediate the ADCC lysis of tumor cells. MSB0010718C (designated avelumab) is a fully human IgG1 anti-PD-L1 MAb. The studies reported here demonstrate (a) the ability of avelumab to lyse a range of human tumor cells in the presence of PBMC or NK effectors; (b) IFNγ can enhance tumor cell PD-L1 expression and in some cases enhance ADCC tumor cell lysis; (c) purified NK cells are potent effectors for avelumab; (d) similar levels of avelumab-mediated ADCC lysis of tumor cells are seen using purified NK as effectors from either healthy donors or cancer patients; (e) very low levels of avelumab-mediated lysis are seen using whole PBMCs as targets; this finding complements results seen in analyses of PBMC subsets of patients receiving avelumab; and (f) the addition of IL12 to NK cells greatly enhances avelumab-mediated ADCC. These studies thus provide an additional mode of action for an anti-PD-L1 MAb and support the rationale for further studies to enhance avelumab-mediated ADCC activity. PMID:26014098

  5. Stable curcumin-loaded polymeric micellar formulation for enhancing cellular uptake and cytotoxicity to FLT3 overexpressing EoL-1 leukemic cells.

    Science.gov (United States)

    Tima, Singkome; Anuchapreeda, Songyot; Ampasavate, Chadarat; Berkland, Cory; Okonogi, Siriporn

    2017-05-01

    The present study aims to develop a stable polymeric micellar formulation of curcumin (CM) with improved solubility and stability, and that is suitable for clinical applications in leukemia patients. CM-loaded polymeric micelles (CM-micelles) were prepared using poloxamers. The chemical structure of the polymers influenced micellar properties. The best formulation of CM-micelles, namely CM-P407, was obtained from poloxamer 407 at drug to polymer ratio of 1:30 and rehydrated with phosphate buffer solution pH 7.4. CM-P407 exhibited the smallest size of 30.3±1.3nm and highest entrapment efficiency of 88.4±4.1%. When stored at -80°C for 60days, CM-P407 retained high protection of CM and had no significant size change. In comparison with CM solution in dimethyl sulfoxide (CM-DMSO), CM kinetic degradation in both formulations followed a pseudo-first-order reaction, but the half-life of CM in CM-P407 was approx. 200 times longer than in CM-DMSO. Regarding the activity against FLT3 overexpressing EoL-1 leukemic cells, CM-P407 showed higher cytotoxicity than CM-DMSO. Moreover, intracellular uptake to leukemic cells of CM-P407 was 2-3 times greater than that of CM-DMSO. These promising results for CM-P407 will be further investigated in rodents and in clinical studies for leukemia treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Expression weighted cell type enrichments reveal genetic and cellular nature of major brain disorders

    Directory of Open Access Journals (Sweden)

    Nathan Gerald Skene

    2016-01-01

    Full Text Available The cell types that trigger the primary pathology in many brain diseases remain largely unknown. One route to understanding the primary pathological cell type for a particular disease is to identify the cells expressing susceptibility genes. Although this is straightforward for monogenic conditions where the causative mutation may alter expression of a cell type specific marker, methods are required for the common polygenic disorders. We developed the Expression Weighted Cell Type Enrichment (EWCE method that uses single cell transcriptomes to generate the probability distribution associated with a gene list having an average level of expression within a cell type. Following validation, we applied EWCE to human genetic data from cases of epilepsy, Schizophrenia, Autism, Intellectual Disability, Alzheimer’s disease, Multiple Sclerosis and anxiety disorders. Genetic susceptibility primarily affected microglia in Alzheimer’s and Multiple Sclerosis; was shared between interneurons and pyramidal neurons in Autism and Schizophrenia; while intellectual disabilities and epilepsy were attributable to a range of cell-types, with the strongest enrichment in interneurons. We hypothesised that the primary cell type pathology could trigger secondary changes in other cell types and these could be detected by applying EWCE to transcriptome data from diseased tissue. In Autism, Schizophrenia and Alzheimer’s disease we find evidence of pathological changes in all of the major brain cell types. These findings give novel insight into the cellular origins and progression in common brain disorders. The methods can be applied to any tissue and disorder and have applications in validating mouse models.

  7. Human NK cells selective targeting of colon cancer-initiating cells: A role for natural cytotoxicity receptors and MHC class i molecules

    KAUST Repository

    Tallerico, Rossana

    2013-01-23

    Tumor cell populations have been recently proposed to be composed of two compartments: tumor-initiating cells characterized by a slow and asymmetrical growth, and the "differentiated" cancer cells with a fast and symmetrical growth. Cancer stem cells or cancer-initiating cells (CICs) play a crucial role in tumor recurrence. The resistance of CICs to drugs and irradiation often allows them to survive traditional therapy. NK cells are potent cytotoxic lymphocytes that can recognize tumor cells. In this study, we have analyzed the NK cell recognition of tumor target cells derived from the two cancer cell compartments of colon adenocarcinoma lesions. Our data demonstrate that freshly purified allogeneic NK cells can recognize and kill colorectal carcinoma- derived CICs whereas the non-CIC counterpart of the tumors (differentiated tumor cells), either autologous or allogeneic, is less susceptible to NK cells. This difference in the NK cell susceptibility correlates with higher expression on CICs of ligands for NKp30 and NKp44 in the natural cytotoxicity receptor (NCR) group of activating NK receptors. In contrast, CICs express lower levels of MHC class I, known to inhibit NK recognition, on their surface than do the "differentiated" tumor cells. These data have been validated by confocal microscopy where NCR ligands and MHC class I molecule membrane distribution have been analyzed. Moreover, NK cell receptor blockade in cytotoxicity assays demonstrates that NCRs play a major role in the recognition of CIC targets. This study strengthens the idea that biology-based therapy harnessing NK cells could be an attractive opportunity in solid tumors. Copyright © 2013 by The American Association of Immunologists, Inc. All rights reserved.

  8. Human NK cells selective targeting of colon cancer-initiating cells: A role for natural cytotoxicity receptors and MHC class i molecules

    KAUST Repository

    Tallerico, Rossana; Todaro, Matilde; Di Franco, Simone; MacCalli, Cristina; Garofalo, Cinzia; Sottile, Rosa; Palmieri, Camillo; Tirinato, Luca; Pangigadde, Pradeepa N.; La Rocca, Rosanna; Mandelboim, Ofer; Stassi, Giorgio; Di Fabrizio, Enzo M.; Parmiani, Giorgio; Moretta, Alessandro; Dieli, Francesco; Kã rre, Klas; Carbone, Ennio

    2013-01-01

    Tumor cell populations have been recently proposed to be composed of two compartments: tumor-initiating cells characterized by a slow and asymmetrical growth, and the "differentiated" cancer cells with a fast and symmetrical growth. Cancer stem cells or cancer-initiating cells (CICs) play a crucial role in tumor recurrence. The resistance of CICs to drugs and irradiation often allows them to survive traditional therapy. NK cells are potent cytotoxic lymphocytes that can recognize tumor cells. In this study, we have analyzed the NK cell recognition of tumor target cells derived from the two cancer cell compartments of colon adenocarcinoma lesions. Our data demonstrate that freshly purified allogeneic NK cells can recognize and kill colorectal carcinoma- derived CICs whereas the non-CIC counterpart of the tumors (differentiated tumor cells), either autologous or allogeneic, is less susceptible to NK cells. This difference in the NK cell susceptibility correlates with higher expression on CICs of ligands for NKp30 and NKp44 in the natural cytotoxicity receptor (NCR) group of activating NK receptors. In contrast, CICs express lower levels of MHC class I, known to inhibit NK recognition, on their surface than do the "differentiated" tumor cells. These data have been validated by confocal microscopy where NCR ligands and MHC class I molecule membrane distribution have been analyzed. Moreover, NK cell receptor blockade in cytotoxicity assays demonstrates that NCRs play a major role in the recognition of CIC targets. This study strengthens the idea that biology-based therapy harnessing NK cells could be an attractive opportunity in solid tumors. Copyright © 2013 by The American Association of Immunologists, Inc. All rights reserved.

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

    Science.gov (United States)

    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. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Natural and semi-synthetic clerodanes of Croton cajucara and their cytotoxic effects against ehrlich carcinoma and human K562 leukemia cells

    Energy Technology Data Exchange (ETDEWEB)

    Maciel, Maria Aparecida M. [Universidade Federal do Rio Grande do Norte, Natal, RN (Brazil). Dept. de Quimica; Martins, Jenilce R.; Pinto, Angelo C.; Kaiser, Carlos R. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Quimica; Esteves-Souza, Andressa; Echevarria, Aurea [Universidade Federal Rural do Rio de Janeiro, Seropedica, RJ (Brazil). Dept. de Quimica]. E-mail: echevarr@ufrrj.br

    2007-03-15

    The clerodane-type diterpene, trans-dehydrocrotonin (1) the major component of Croton cajucara has shown striking correlation with its therapeutic use in traditional folk medicine. Phytochemical investigations led to the isolation of the metabolites 1, cajucarinolide (6), isocajucarinolide (7), trans-crotonin (2), trans-cajucarin B (3), cis-cajucarin B (4), trans-cajucarin A (5), N-methyltyrosine, vanillic acid and 4-hydroxy-benzoic acid. 6 and 7 were synthesized in good yield by regiospecific oxidation of 1 using singlet-oxygen. All clerodanes were studied for their cytotoxic effects against human K562 leukemia and Ehrlich carcinoma cells. Ehrlich carcinoma assays with IC{sub 50} = 166 {mu}M (1), 164 {mu}M (2), 65 {mu}M (6) and 10 {mu}M (7) related to cell growth inhibitory effects were dose dependent. Furthermore, moderate cytotoxic activity against K562 leukemia cells was observed with IC{sub 50} = 38 {mu}M (3), 33 {mu}M (5), 36 {mu}M (6) and 43 {mu}M (7). The semi-synthetic 2, 6 and 7 showed similar results when compared to the corresponding natural clerodanes. (author)

  11. Natural and semi-synthetic clerodanes of Croton cajucara and their cytotoxic effects against ehrlich carcinoma and human K562 leukemia cells

    International Nuclear Information System (INIS)

    Maciel, Maria Aparecida M.; Martins, Jenilce R.; Pinto, Angelo C.; Kaiser, Carlos R.; Esteves-Souza, Andressa; Echevarria, Aurea

    2007-01-01

    The clerodane-type diterpene, trans-dehydrocrotonin (1) the major component of Croton cajucara has shown striking correlation with its therapeutic use in traditional folk medicine. Phytochemical investigations led to the isolation of the metabolites 1, cajucarinolide (6), isocajucarinolide (7), trans-crotonin (2), trans-cajucarin B (3), cis-cajucarin B (4), trans-cajucarin A (5), N-methyltyrosine, vanillic acid and 4-hydroxy-benzoic acid. 6 and 7 were synthesized in good yield by regiospecific oxidation of 1 using singlet-oxygen. All clerodanes were studied for their cytotoxic effects against human K562 leukemia and Ehrlich carcinoma cells. Ehrlich carcinoma assays with IC 50 = 166 μM (1), 164 μM (2), 65 μM (6) and 10 μM (7) related to cell growth inhibitory effects were dose dependent. Furthermore, moderate cytotoxic activity against K562 leukemia cells was observed with IC 50 = 38 μM (3), 33 μM (5), 36 μM (6) and 43 μM (7). The semi-synthetic 2, 6 and 7 showed similar results when compared to the corresponding natural clerodanes. (author)

  12. Oxaliplatin regulates expression of stress ligands in ovarian cancer cells and modulates their susceptibility to natural killer cell-mediated cytotoxicity.

    Science.gov (United States)

    Siew, Yin-Yin; Neo, Soek-Ying; Yew, Hui-Chuing; Lim, Shun-Wei; Ng, Yi-Cheng; Lew, Si-Min; Seetoh, Wei-Guang; Seow, See-Voon; Koh, Hwee-Ling

    2015-12-01

    Selected cytotoxic chemicals can provoke the immune system to recognize and destroy malignant tumors. Most of the studies on immunogenic cell death are focused on the signals that operate on a series of receptors expressed by dendritic cells to induce tumor antigen-specific T-cell responses. Here, we explored the effects of oxaliplatin, an immunogenic cell death inducer, on the induction of stress ligands and promotion of natural killer (NK) cell-mediated cytotoxicity in human ovarian cancer cells. The results indicated that treatment of tumor cells with oxaliplatin induced the production of type I interferons and chemokines and enhanced the expression of major histocompatibility complex class I-related chains (MIC) A/B, UL16-binding protein (ULBP)-3, CD155 and TNF-related apoptosis-inducing ligand (TRAIL)-R1/R2. Furthermore, oxaliplatin but not cisplatin treatment enhanced susceptibility of ovarian cancer cells to NK cell-mediated cytolysis. In addition, activated NK cells completely abrogated the growth of cancer cells that were pretreated with oxaliplatin. However, cancer cells pretreated with the same concentration of oxaliplatin alone were capable of potentiating regrowth over a period of time. These results suggest an advantage in combining oxaliplatin and NK cell-based therapy in the treatment of ovarian cancer. Further investigation on such potential combination therapy is warranted. © The Japanese Society for Immunology. 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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

    Energy Technology Data Exchange (ETDEWEB)

    Joshy, K.S. [Department of Chemistry, CMS College Kottayam, Kerala (India); International and Inter University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam 686 560, Kerala (India); Sharma, Chandra P. [Division of Biosurface Technology, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Science and Technology, Poojappura, Thiruvananthapuram, Kerala (India); Kalarikkal, Nandakumar [International and Inter University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam 686 560, Kerala (India); School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam 686 560, Kerala (India); Sandeep, K. [International and Inter University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam 686 560, Kerala (India); Thomas, Sabu, E-mail: sabuchathukulam@yahoo.co.uk [International and Inter University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam 686 560, Kerala (India); School of Chemical Sciences, Mahatma Gandhi University, Kottayam 686 560, Kerala (India); Pothen, Laly A. [Department of Chemistry, Bishop Moore College, Mavelikkara, Kerala (India)

    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 ± 12.22 nm and modified solid lipid nanoparticles showed an average size of 265.61 ± 80.44 nm. 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. - Highlights: • SLN of AZT-SA, AZT-SA-AV was developed • Better drug loading efficacy • Good uptake.

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

    International Nuclear Information System (INIS)

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

    2016-01-01

    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 ± 12.22 nm and modified solid lipid nanoparticles showed an average size of 265.61 ± 80.44 nm. 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. - Highlights: • SLN of AZT-SA, AZT-SA-AV was developed • Better drug loading efficacy • Good uptake

  15. Large-Scale Culture and Genetic Modification of Human Natural Killer Cells for Cellular Therapy.

    Science.gov (United States)

    Lapteva, Natalia; Parihar, Robin; Rollins, Lisa A; Gee, Adrian P; Rooney, Cliona M

    2016-01-01

    Recent advances in methods for the ex vivo expansion of human natural killer (NK) cells have facilitated the use of these powerful immune cells in clinical protocols. Further, the ability to genetically modify primary human NK cells following rapid expansion allows targeting and enhancement of their immune function. We have successfully adapted an expansion method for primary NK cells from peripheral blood mononuclear cells or from apheresis products in gas permeable rapid expansion devices (G-Rexes). Here, we describe an optimized protocol for rapid and robust NK cell expansion as well as a method for highly efficient retroviral transduction of these ex vivo expanded cells. These methodologies are good manufacturing practice (GMP) compliant and could be used for clinical-grade product manufacturing.

  16. Zinc in Cellular Regulation: The Nature and Significance of "Zinc Signals".

    Science.gov (United States)

    Maret, Wolfgang

    2017-10-31

    In the last decade, we witnessed discoveries that established Zn 2+ as a second major signalling metal ion in the transmission of information within cells and in communication between cells. Together with Ca 2+ and Mg 2+ , Zn 2+ covers biological regulation with redox-inert metal ions over many orders of magnitude in concentrations. The regulatory functions of zinc ions, together with their functions as a cofactor in about three thousand zinc metalloproteins, impact virtually all aspects of cell biology. This article attempts to define the regulatory functions of zinc ions, and focuses on the nature of zinc signals and zinc signalling in pathways where zinc ions are either extracellular stimuli or intracellular messengers. These pathways interact with Ca 2+ , redox, and phosphorylation signalling. The regulatory functions of zinc require a complex system of precise homeostatic control for transients, subcellular distribution and traffic, organellar homeostasis, and vesicular storage and exocytosis of zinc ions.

  17. Structure-cytotoxicity relationships for dietary flavonoids

    DEFF Research Database (Denmark)

    Breinholt, V.; Dragsted, L.O.

    1998-01-01

    The cytotoxicity of a large series of dietary flavonoids was tested in a non-tumorigenic mouse and two human cancer cell lines, using the neutral red dye exclusion assay. All compounds tested exhibited a concentration-dependent cytotoxic action in the employed cell lines. The relative cytotoxicity...... of the flavonoids, however, Tvas found to vary greatly among the different cell Lines. With a few exceptions, the investigated flavonoids were more cytotoxic to the human cancer cell lines, than the mouse cell line. The differences in cytotoxicity were accounted for in part by differences in cellular uptake...... and metabolic capacity among the different cell types. In 3T3 cells fairly consistent structure-cytotoxicity relationships were found. The most cytotoxic structures tested in 3T3 cells were flavonoids with adjacent 3',4' hydroxy groups on the B-ring, such as luteolin, quercetin, myricetin, fisetin, eriodictyol...

  18. Preparation and evaluation of the cytotoxic nature of TiO2 nanoparticles by direct contact method

    Directory of Open Access Journals (Sweden)

    Chellappa M

    2015-10-01

    Full Text Available M Chellappa,1 U Anjaneyulu,1 Geetha Manivasagam,2 U Vijayalakshmi1 1School of Advanced Sciences, Materials Chemistry Division, 2Centre for Biomaterials Science and Technology, School of Mechanical and Building Sciences, VIT University, Vellore, Tamil Nadu, India Abstract: The purpose of this study is to prepare and evaluate the effect of synthesized titanium dioxide (TiO2 nanoparticles for their biocompatibility on physiological body fluids and the effect of cell toxicity to produce osteointegration when used as implantable materials. For the past few decades, the number of researches done to understand the importance of the biocompatibility of bioceramics, metals, and polymers and their effect on clinical settings of biomedical devices has increased. Hence, the total concept of biocompatibility encourages researchers to actively engage in the investigation of the most compatible materials in living systems by analyzing them using suitable physical, chemical, and biological (bioassay methods. The ceramic material nano TiO2 was prepared by sol-gel method and analyzed for its functional group and phase formation by Fourier transform infrared spectroscopy and powder X-ray diffraction. Furthermore, the particle size, shape, surface topography, and morphological behavior were analyzed by dynamic light scattering, zeta potential, scanning electron microscopy–energy dispersive X-ray analysis, and transmission electron microscopy analysis. In addition to this, the cytotoxicity and cytocompatibility were determined on MG63 cell lines with varying doses of concentrations such as 1 µg/mL, 10 µg/mL, 25 µg/mL, 50 µg/mL, and 100 µg/mL with different time periods such as 24 hours and 48 hours. The results have not shown any toxicity, whereas, it improved the cell viability/proliferation at various concentrations. Hence, these findings indicate that the nano TiO2 material acts as a good implantable material when used in the biomedical field as a

  19. 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.

    Directory of Open Access Journals (Sweden)

    Masaki Kurogochi

    Full Text Available 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

  20. 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.

    Science.gov (United States)

    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, and

  1. Biocompatible coated magnetosome minerals with various organization and cellular interaction properties induce cytotoxicity towards RG-2 and GL-261 glioma cells in the presence of an alternating magnetic field.

    Science.gov (United States)

    Hamdous, Yasmina; Chebbi, Imène; Mandawala, Chalani; Le Fèvre, Raphael; Guyot, François; Seksek, Olivier; Alphandéry, Edouard

    2017-10-17

    Biologics magnetics nanoparticles, magnetosomes, attract attention because of their magnetic characteristics and potential applications. The aim of the present study was to develop and characterize novel magnetosomes, which were extracted from magnetotactic bacteria, purified to produce apyrogen magnetosome minerals, and then coated with Chitosan, Neridronate, or Polyethyleneimine. It yielded stable magnetosomes designated as M-Chi, M-Neri, and M-PEI, respectively. Nanoparticle biocompatibility was evaluated on mouse fibroblast cells (3T3), mouse glioblastoma cells (GL-261) and rat glioblastoma cells (RG-2). We also tested these nanoparticles for magnetic hyperthermia treatment of tumor in vitro on two tumor cell lines GL-261 and RG-2 under the application of an alternating magnetic field. Heating, efficacy and internalization properties were then evaluated. Nanoparticles coated with chitosan, polyethyleneimine and neridronate are apyrogen, biocompatible and stable in aqueous suspension. The presence of a thin coating in M-Chi and M-PEI favors an arrangement in chains of the magnetosomes, similar to that observed in magnetosomes directly extracted from magnetotactic bacteria, while the thick matrix embedding M-Neri leads to structures with an average thickness of 3.5 µm 2 per magnetosome mineral. In the presence of GL-261 cells and upon the application of an alternating magnetic field, M-PEI and M-Chi lead to the highest specific absorption rates of 120-125 W/g Fe . Furthermore, while M-Chi lead to rather low rates of cellular internalization, M-PEI strongly associate to cells, a property modulated by the application of an alternating magnetic field. Coating of purified magnetosome minerals can therefore be chosen to control the interactions of nanoparticles with cells, organization of the minerals, as well as heating and cytotoxicity properties, which are important parameters to be considered in the design of a magnetic hyperthermia treatment of tumor.

  2. Anti-Glycoprotein G Antibodies of Herpes Simplex Virus 2 Contribute to Complete Protection after Vaccination in Mice and Induce Antibody-Dependent Cellular Cytotoxicity and Complement-Mediated Cytolysis

    Directory of Open Access Journals (Sweden)

    Staffan Görander

    2014-11-01

    Full Text Available We investigated the role of antibodies against the mature portion of glycoprotein G (mgG-2 of herpes simplex virus 2 (HSV-2 in protective immunity after vaccination. Mice were immunized intramuscularly with mgG-2 and oligodeoxynucleotides containing two CpG motifs plus alum as adjuvant. All C57BL/6 mice survived and presented no genital or systemic disease. High levels of immunoglobulin G subclass 1 (IgG1 and IgG2 antibodies were detected and re-stimulated splenic CD4+ T cells proliferated and produced IFN-γ. None of the sera from immunized mice exhibited neutralization, while all sera exerted antibody-dependent cellular cytotoxicity (ADCC and complement-mediated cytolysis (ACMC activity. Passive transfer of anti-mgG-2 monoclonal antibodies, or immune serum, to naive C57BL/6 mice did not limit disease progression. Immunized B‑cell KO mice presented lower survival rate and higher vaginal viral titers, as compared with vaccinated B-cell KO mice after passive transfer of immune serum and vaccinated C57BL/6 mice. Sera from mice that were vaccinated subcutaneously and intranasally with mgG-2 presented significantly lower titers of IgG antibodies and lower ADCC and ACMC activity. We conclude that anti-mgG-2 antibodies were of importance to limit genital HSV‑2 infection. ADCC and ACMC activity are potentially important mechanisms in protective immunity, and could tentatively be evaluated in future animal vaccine studies and in clinical trials.

  3. Stress-Induced In Vivo Recruitment of Human Cytotoxic Natural Killer Cells Favors Subsets with Distinct Receptor Profiles and Associates with Increased Epinephrine Levels.

    Directory of Open Access Journals (Sweden)

    Marc B Bigler

    Full Text Available Acute stress drives a 'high-alert' response in the immune system. Psychoactive drugs induce distinct stress hormone profiles, offering a sought-after opportunity to dissect the in vivo immunological effects of acute stress in humans.3,4-methylenedioxymethamphetamine (MDMA, methylphenidate (MPH, or both, were administered to healthy volunteers in a randomized, double-blind, placebo-controlled crossover-study. Lymphocyte subset frequencies, natural killer (NK cell immune-phenotypes, and changes in effector function were assessed, and linked to stress hormone levels and expression of CD62L, CX3CR1, CD18, and stress hormone receptors on NK cells.MDMA/MPH > MDMA > MPH robustly induced an epinephrine-dominant stress response. Immunologically, rapid redistribution of peripheral blood lymphocyte-subsets towards phenotypically mature NK cells occurred. NK cytotoxicity was unaltered, but they expressed slightly reduced levels of the activating receptor NKG2D. Preferential circulation of mature NK cells was associated with high epinephrine receptor expression among this subset, as well as expression of integrin ligands previously linked to epinephrine-induced endothelial detachment.The acute epinephrine-induced stress response was characterized by rapid accumulation of mature and functional NK cells in the peripheral circulation. This is in line with studies using other acute stressors and supports the role of the acute stress response in rapidly mobilizing the innate immune system to counteract incoming threats.

  4. Biomechanics of cellular solids.

    Science.gov (United States)

    Gibson, Lorna J

    2005-03-01

    Materials with a cellular structure are widespread in nature and include wood, cork, plant parenchyma and trabecular bone. Natural cellular materials are often mechanically efficient: the honeycomb-like microstructure of wood, for instance, gives it an exceptionally high performance index for resisting bending and buckling. Here we review the mechanics of a wide range of natural cellular materials and examine their role in lightweight natural sandwich structures (e.g. iris leaves) and natural tubular structures (e.g. plant stems or animal quills). We also describe two examples of engineered biomaterials with a cellular structure, designed to replace or regenerate tissue in the body.

  5. Determination of the absolute configurations of natural products via density functional theory calculations of optical rotation, electronic circular dichroism, and vibrational circular dichroism: the cytotoxic sesquiterpene natural products quadrone, suberosenone, suberosanone, and suberosenol A acetate.

    Science.gov (United States)

    Stephens, P J; McCann, D M; Devlin, F J; Smith, A B

    2006-07-01

    The determination of the absolute configurations (ACs) of chiral molecules using the chiroptical techniques of optical rotation (OR), electronic circular dichroism (ECD), and vibrational circular dichroism (VCD) has been revolutionized by the development of density functional theory (DFT) methods for the prediction of these properties. Here, we demonstrate the significance of these advances for the stereochemical characterization of natural products. Time-dependent DFT (TDDFT) calculations of the specific rotations, [alpha](D), of four cytotoxic natural products, quadrone (1), suberosenone (2), suberosanone (3), and suberosenol A acetate (4), are used to assign their ACs. TDDFT calculations of the ECD of 1 are used to assign its AC. The VCD spectrum of 1 is reported and also used, together with DFT calculations, to assign its AC. The ACs of 1 derived from its [alpha](D), ECD, and VCD are identical and in agreement with the AC previously determined via total synthesis. The previously undetermined ACs of 2-4, derived from their [alpha](D) values, have absolute configurations of their tricyclic cores identical to that of 1. Further studies of the ACs of these molecules using ECD and, especially, VCD are recommended to establish more definitively this finding. Our studies of the OR, ECD, and VCD of quadrone are the first to utilize DFT calculations of all three properties for the determination of the AC of a chiral natural product molecule.

  6. A novel antibody-dependent cellular cytotoxicity epitope in gp120 is identified by two monoclonal antibodies isolated from a long-term survivor of human immunodeficiency virus type 1 infection.

    Science.gov (United States)

    Alsmadi, O; Herz, R; Murphy, E; Pinter, A; Tilley, S A

    1997-01-01

    Two monoclonal antibodies (MAbs), 42F and 43F, were isolated some 14 months apart from a single long-term survivor of human immunodeficiency virus type 1 (HIV-1) infection. These MAbs were found to be indistinguishable in terms of their isotypes, specificities, affinities, and biological activities. Both 42F and 43F directed substantial antibody-dependent cellular cytotoxicity (ADCC) against cells infected with four divergent lab-adapted strains of HIV-1, but no neutralizing activity against these strains was detectable. The ability of MAbs 42F and 43F, as well as that of MAbs against two other gp120 epitopes, to direct ADCC against uninfected CD4+ cells to which recombinant gp120SF2 had been adsorbed (i.e., "innocent bystanders") was demonstrated to be less efficient by at least an order of magnitude than their ability to direct ADCC against HIV-1-infected cells. Flow cytometry analyses showed that 42F and 43F also bind to native primary isolate Envs from clades B and E expressed on cell surfaces. By direct binding and competition assays, it was demonstrated that the 42F/43F epitope lies in a domain of gp120 outside the previously described CD4-binding site and V3 loop ADCC epitope clusters. Immunoblot analysis revealed that the 42F/43F epitope is not dependent on disulfide bonds or N-linked glycans in gp120. Epitope mapping of 42F and 43F by binding to linear peptides demonstrated specificity of these MAbs for a sequence of 10 amino acids in the C5 domain comprising residues 491 to 500 (Los Alamos National Laboratory numbering for the HXB2 strain). Thus, 42F and 43F define a new ADCC epitope in gp120. Because of the relative conservation of this epitope and the fact that it appears to have been significantly immunogenic in the individual from which these MAbs were derived, it may prove to be a useful component of HIV vaccines. Furthermore, these MAbs may be used as tools to probe the potential importance of ADCC as an antiviral activity in HIV-1 infection. PMID

  7. A New Natural Product Analog of Blasticidin S Reveals Cellular Uptake Facilitated by the NorA Multidrug Transporter.

    Science.gov (United States)

    Davison, Jack R; Lohith, Katheryn M; Wang, Xiaoning; Bobyk, Kostyantyn; Mandadapu, Sivakoteswara R; Lee, Su-Lin; Cencic, Regina; Nelson, Justin; Simpkins, Scott; Frank, Karen M; Pelletier, Jerry; Myers, Chad L; Piotrowski, Jeff; Smith, Harold E; Bewley, Carole A

    2017-06-01

    The permeation of antibiotics through bacterial membranes to their target site is a crucial determinant of drug activity but in many cases remains poorly understood. During screening efforts to discover new broad-spectrum antibiotic compounds from marine sponge samples, we identified a new analog of the peptidyl nucleoside antibiotic blasticidin S that exhibited up to 16-fold-improved potency against a range of laboratory and clinical bacterial strains which we named P10. Whole-genome sequencing of laboratory-evolved strains of Staphylococcus aureus resistant to blasticidin S and P10, combined with genome-wide assessment of the fitness of barcoded Escherichia coli knockout strains in the presence of the antibiotics, revealed that restriction of cellular access was a key feature in the development of resistance to this class of drug. In particular, the gene encoding the well-characterized multidrug efflux pump NorA was found to be mutated in 69% of all S. aureus isolates resistant to blasticidin S or P10. Unexpectedly, resistance was associated with inactivation of norA , suggesting that the NorA transporter facilitates cellular entry of peptidyl nucleosides in addition to its known role in the efflux of diverse compounds, including fluoroquinolone antibiotics. Copyright © 2017 American Society for Microbiology.

  8. Sensitive Detection of the Natural Killer Cell-Mediated Cytotoxicity of Anti-CD20 Antibodies and Its Impairment by B-Cell Receptor Pathway Inhibitors

    Directory of Open Access Journals (Sweden)

    Floyd Hassenrück

    2018-01-01

    Full Text Available The antibody-dependent cell-mediated cytotoxicity (ADCC of the anti-CD20 monoclonal antibodies (mAbs rituximab and obinutuzumab against the cell line Raji and isolated CLL cells and its potential impairment by kinase inhibitors (KI was determined via lactate dehydrogenase release or calcein retention, respectively, using genetically modified NK92 cells expressing CD16-176V as effector cells. Compared to peripheral blood mononuclear cells, recombinant effector cell lines showed substantial alloreactivity-related cytotoxicity without addition of mAbs but afforded determination of ADCC with reduced interassay variability. The cytotoxicity owing to alloreactivity was less susceptible to interference by KI than the ADCC of anti-CD20 mAbs, which was markedly diminished by ibrutinib, but not by idelalisib. Compared to rituximab, the ADCC of obinutuzumab against primary CLL cells showed approximately 30% higher efficacy and less interference with KI. Irreversible BTK inhibitors at a clinically relevant concentration of 1 μM only weakly impaired the ADCC of anti-CD20 mAbs, with less influence in combinations with obinutuzumab than with rituximab and by acalabrutinib than by ibrutinib or tirabrutinib. In summary, NK cell line-based assays permitted the sensitive detection of ADCC of therapeutic anti-CD20 mAbs against CLL cells and of the interference of KI with this important killing mechanism.

  9. Adoptive transfer of natural antibodies to non-immunized chickens affects subsequent antigen-specific humoral and cellular immune responses

    NARCIS (Netherlands)

    Lammers, A.; Klomp, M.E.V.; Nieuwland, M.G.B.; Savelkoul, H.F.J.; Parmentier, H.K.

    2004-01-01

    To determine a regulatory function of natural antibodies in the immune response of chickens, pooled plasma obtained from non-immunized (naive) 15 months old hens was subjected to keyhole limpet hemocyanin (KLH) antigen-affinity chromatography. Purified KLH-binding antibodies were adoptively

  10. The effect of natural and synthetic fatty acids on membrane structure, microdomain organization, cellular functions and human health.

    Science.gov (United States)

    Ibarguren, Maitane; López, David J; Escribá, Pablo V

    2014-06-01

    This review deals with the effects of synthetic and natural fatty acids on the biophysical properties of membranes, and on their implication on cell function. Natural fatty acids are constituents of more complex lipids, like triacylglycerides or phospholipids, which are used by cells to store and obtain energy, as well as for structural purposes. Accordingly, natural and synthetic fatty acids may modify the structure of the lipid membrane, altering its microdomain organization and other physical properties, and provoking changes in cell signaling. Therefore, by modulating fatty acids it is possible to regulate the structure of the membrane, influencing the cell processes that are reliant on this structure and potentially reverting pathological cell dysfunctions that may provoke cancer, diabetes, hypertension, Alzheimer's and Parkinson's disease. The so-called Membrane Lipid Therapy offers a strategy to regulate the membrane composition through drug administration, potentially reverting pathological processes by re-adapting cell membrane structure. Certain fatty acids and their synthetic derivatives are described here that may potentially be used in such therapies, where the cell membrane itself can be considered as a target to combat disease. This article is part of a Special Issue entitled: Membrane Structure and Function: Relevance in the Cell's Physiology, Pathology and Therapy. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Ganoderma lucidum stimulates NK cell cytotoxicity by inducing NKG2D/NCR activation and secretion of perforin and granulysin.

    Science.gov (United States)

    Chang, Chih-Jung; Chen, Yi-Yuan M; Lu, Chia-Chen; Lin, Chuan-Sheng; Martel, Jan; Tsai, Sheng-Hui; Ko, Yun-Fei; Huang, Tsung-Teng; Ojcius, David M; Young, John D; Lai, Hsin-Chih

    2014-04-01

    Ganoderma lucidum (G. lucidum) is a medicinal mushroom long used in Asia as a folk remedy to promote health and longevity. Recent studies indicate that G. lucidum activates NK cells, but the molecular mechanism underlying this effect has not been studied so far. To address this question, we prepared a water extract of G. lucidum and examined its effect on NK cells. We observed that G. lucidum treatment increases NK cell cytotoxicity by stimulating secretion of perforin and granulysin. The mechanism of activation involves an increased expression of NKG2D and natural cytotoxicity receptors (NCRs), as well as increased phosphorylation of intracellular MAPKs. Our results indicate that G. lucidum induces NK cell cytotoxicity against various cancer cell lines by activating NKG2D/NCR receptors and MAPK signaling pathways, which together culminate in exocytosis of perforin and granulysin. These observations provide a cellular and molecular mechanism to account for the reported anticancer effects of G. lucidum extracts in humans.

  12. DIFFERENTIAL BINDING OF HUMAN INTERLEUKIN-1 (IL-1) RECEPTOR ANTAGONIST TO NATURAL AND RECOMBINANT SOLUBLE AND CELLULAR IL-1 TYPE-I RECEPTORS

    DEFF Research Database (Denmark)

    Svenson, Morten; Nedergaard, Susanne; Heegaard, Peter M. H.

    1995-01-01

    antagonist (IL-1ra). Recombinant soluble human IL-1RI expressed in COS cells (sIL-1RI) consists of the extracellular part of the receptor and binds all three known IL-1 species but preferentially to IL-1ra. We further characterized the sizes and binding of IL-1raBF and sIL-1RI to IL-1ra by polyacrylamide gel...... electrophoresis in the presence of sodium dodecylsulfate, ligand binding interference analyses, N-glycosidase treatment, concanavalin A affinity chromatography, and with the use of monoclonal antibodies (mAb) to human recombinant IL-1ra. We also evaluated the binding of IL-1ra to cellular IL-1RI on MRC5...... binding of both molecules to IL-1ra. Both factors blocked binding of IL-1ra to cellular IL-1RI, as did mAb to IL-1ra, but the sites on IL-1ra which bound to the mAb, and to IL-1raBF and sIL-1RI, differed. We conclude that there are important differences between the natural and recombinant forms of soluble...

  13. Cellular and molecular effects of natural background radiation on human population in Kerala coast, India: from chromosome ends to transcriptome

    Energy Technology Data Exchange (ETDEWEB)

    Das, Birajalaxmi; Jain, Vinay; Saini, Divyalakshmi; Ghosh, Anu; Seshadri, M. [Radiation Biology and Health Sciences Division, Bio-Medical Group, Bhabha Atomic Research Centre, Mumbai (India); Sandhya Kiran, P. [Ocimum Biosolutions India Limited, Hyderabad (India)

    2010-07-01

    Venous blood samples of 32 male volunteers (age group 35-45 years) from different background dose groups. Factors like life style, smoking, drinking alcohol, chewing, previous exposure to radiation and medical history etc. were properly recorded. Microarray analysis was performed using Affymetrix FlGU133 plus 2.0 chip and the expression level of 54,675 genes were obtained for each sample. In order to assess the effect of chronic natural background radiation we have categorized our samples into four groups. To derive genes that are differentially regulated between these four groups, 'Exposed group versus Control' was set up and the linear model was fitted to each gene using the expression data on samples. A fold change threshold of 1.3, 1.5 and 2.0 and an adjusted p-value threshold of 0.05 was set in the study. Analysis was done using 'limma' library of R and Genowiz.

  14. Cellular and molecular effects of natural background radiation on human population in Kerala coast, India: from chromosome ends to transcriptome

    International Nuclear Information System (INIS)

    Das, Birajalaxmi; Jain, Vinay; Saini, Divyalakshmi; Ghosh, Anu; Seshadri, M.; Sandhya Kiran, P.

    2010-01-01

    Venous blood samples of 32 male volunteers (age group 35-45 years) from different background dose groups. Factors like life style, smoking, drinking alcohol, chewing, previous exposure to radiation and medical history etc. were properly recorded. Microarray analysis was performed using Affymetrix FlGU133 plus 2.0 chip and the expression level of 54,675 genes were obtained for each sample. In order to assess the effect of chronic natural background radiation we have categorized our samples into four groups. To derive genes that are differentially regulated between these four groups, 'Exposed group versus Control' was set up and the linear model was fitted to each gene using the expression data on samples. A fold change threshold of 1.3, 1.5 and 2.0 and an adjusted p-value threshold of 0.05 was set in the study. Analysis was done using 'limma' library of R and Genowiz

  15. Production of proinflammatory cytokines without invocation of cytotoxic effects by an Epstein-Barr virus-infected natural killer cell line established from a patient with hypersensitivity to mosquito bites.

    Science.gov (United States)

    Suzuki, Daisuke; Tsuji, Kazuhide; Yamamoto, Takenobu; Fujii, Kazuyasu; Iwatsuki, Keiji

    2010-10-01

    Cumulative evidence supports that Epstein-Barr virus (EBV)-infected natural killer (NK) cells induce severe systemic and cutaneous inflammation in patients with hypersensitivity to mosquito bites (HMB). In order to understand the pathogenesis of HMB, we established an EBV-infected cell line and characterized the cytological profiles. A novel EBV-infected NK-cell line, designated NKED, was established from a patient with HMB and used for the present study along with two other NK-cell lines, KAI3 and KHYG-1. NKED expressed the latency II-related transcripts. NKED cells were positive for CD2 and CD161 antigens, and negative for CD3, CD16, CD34, CD56, and T-cell receptor α/β and γ/δ antigens. Although NKED cells contained several cytotoxic molecules, the cells had an extremely poor cytotoxic activity. The majority of NKED cells were negative for perforin, major histocompatibility complex class I-restricted NK-cell receptors, CD94 and KIR2D, and an activating receptor, NKG2D. NKED cells, however, secreted higher levels of tumor necrosis factor-α. Stimulation with phorbol 12-myristate 13-acetate or tumor necrosis factor-α induced expression of BZLF1 messenger RNA in the NKED and KAI3 cells, indicating the transition from the latent- to the lytic-cycle infection. These data suggested that NKED cells revealed a very low cytotoxic effect probably because of the low expression levels of perforin, but had the ability to release proinflammatory cytokines. NKED cells did not reflect the characteristics of HMB, as they were different from pathogenic NK cells proliferating in the HMB patient, but the difference indicated that pathogenic NK cells could change their character in the presence of interleukin-2. Copyright © 2010 ISEH - Society for Hematology and Stem Cells. Published by Elsevier Inc. All rights reserved.

  16. The Natural Flavonoid Fisetin Inhibits Cellular Proliferation of Hepatic, Colorectal, and Pancreatic Cancer Cells through Modulation of Multiple Signaling Pathways.

    Science.gov (United States)

    Youns, Mаhmoud; Abdel Halim Hegazy, Wael

    2017-01-01

    Digestive cancers are major causes of mortality and morbidity worldwide. Fisetin, a naturally occurring flavonoid, has been previously shown anti-proliferative, anti-cancer, neuroprotective, and antioxidant activities. In our study, the anti-tumor activities in addition to regulatory effects of fisetin on some cancer cell lines were investigated. Data presented here showed that fisetin induces growth inhibition, and apoptosis in hepatic (HepG-2), colorectal (Caco-2) and pancreatic (Suit-2) cancer cell lines. Gene expression results showed that 1307 genes were significantly regulated in their expression in hepatic and pancreatic cell lines. 350 genes were commonly up-regulated and 353 genes were commonly down-regulated. Additionally, 604 genes were oppositely expressed in both tumor cells. CDK5 signaling, NRF2-mediated oxidative stress response, glucocorticoid signaling, and ERK/MAPK signaling were among most prominent signaling pathways modulating the growth inhibitory effects of fisetin on hepatic and pancreatic cancer cells. The present analysis showed, for the first time, that the anti-tumor effect of fisetin was mediated mainly through modulation of multiple signaling pathways and via activation of CDKN1A, SEMA3E, GADD45B and GADD45A and down-regulation of TOP2A, KIF20A, CCNB2 and CCNB1 genes.

  17. The Natural Flavonoid Fisetin Inhibits Cellular Proliferation of Hepatic, Colorectal, and Pancreatic Cancer Cells through Modulation of Multiple Signaling Pathways.

    Directory of Open Access Journals (Sweden)

    Mаhmoud Youns

    Full Text Available Digestive cancers are major causes of mortality and morbidity worldwide. Fisetin, a naturally occurring flavonoid, has been previously shown anti-proliferative, anti-cancer, neuroprotective, and antioxidant activities. In our study, the anti-tumor activities in addition to regulatory effects of fisetin on some cancer cell lines were investigated. Data presented here showed that fisetin induces growth inhibition, and apoptosis in hepatic (HepG-2, colorectal (Caco-2 and pancreatic (Suit-2 cancer cell lines. Gene expression results showed that 1307 genes were significantly regulated in their expression in hepatic and pancreatic cell lines. 350 genes were commonly up-regulated and 353 genes were commonly down-regulated. Additionally, 604 genes were oppositely expressed in both tumor cells. CDK5 signaling, NRF2-mediated oxidative stress response, glucocorticoid signaling, and ERK/MAPK signaling were among most prominent signaling pathways modulating the growth inhibitory effects of fisetin on hepatic and pancreatic cancer cells. The present analysis showed, for the first time, that the anti-tumor effect of fisetin was mediated mainly through modulation of multiple signaling pathways and via activation of CDKN1A, SEMA3E, GADD45B and GADD45A and down-regulation of TOP2A, KIF20A, CCNB2 and CCNB1 genes.

  18. The Natural Flavonoid Fisetin Inhibits Cellular Proliferation of Hepatic, Colorectal, and Pancreatic Cancer Cells through Modulation of Multiple Signaling Pathways

    Science.gov (United States)

    Youns, Mаhmoud; Abdel Halim Hegazy, Wael

    2017-01-01

    Digestive cancers are major causes of mortality and morbidity worldwide. Fisetin, a naturally occurring flavonoid, has been previously shown anti-proliferative, anti-cancer, neuroprotective, and antioxidant activities. In our study, the anti-tumor activities in addition to regulatory effects of fisetin on some cancer cell lines were investigated. Data presented here showed that fisetin induces growth inhibition, and apoptosis in hepatic (HepG-2), colorectal (Caco-2) and pancreatic (Suit-2) cancer cell lines. Gene expression results showed that 1307 genes were significantly regulated in their expression in hepatic and pancreatic cell lines. 350 genes were commonly up-regulated and 353 genes were commonly down-regulated. Additionally, 604 genes were oppositely expressed in both tumor cells. CDK5 signaling, NRF2-mediated oxidative stress response, glucocorticoid signaling, and ERK/MAPK signaling were among most prominent signaling pathways modulating the growth inhibitory effects of fisetin on hepatic and pancreatic cancer cells. The present analysis showed, for the first time, that the anti-tumor effect of fisetin was mediated mainly through modulation of multiple signaling pathways and via activation of CDKN1A, SEMA3E, GADD45B and GADD45A and down-regulation of TOP2A, KIF20A, CCNB2 and CCNB1 genes. PMID:28052097

  19. A Daily Dose of 5 mg Folic Acid for 90 Days Is Associated with Increased Serum Unmetabolized Folic Acid and Reduced Natural Killer Cell Cytotoxicity in Healthy Brazilian Adults.

    Science.gov (United States)

    Paniz, Clovis; Bertinato, Juliano Felix; Lucena, Maylla Rodrigues; De Carli, Eduardo; Amorim, Patrícia Mendonça da Silva; Gomes, Guilherme Wataru; Palchetti, Cecília Zanin; Figueiredo, Maria Stella; Pfeiffer, Christine M; Fazili, Zia; Green, Ralph; Guerra-Shinohara, Elvira Maria

    2017-09-01

    Background: The effects of high-dose folic acid (FA) supplementation in healthy individuals on blood folate concentrations and immune response are unknown. Objective: The aim of the study was to evaluate the effects of daily consumption of a tablet containing 5 mg FA on serum folate; number and cytotoxicity of natural killer (NK) cells; mRNA expression of dihydrofolate reductase ( DHFR ), methylenetetrahydrofolate reductase ( MTHFR ), interferon γ ( IFNG ), tumor necrosis factor α ( TNFA ), and interleukin 8 ( IL8 ) genes; and concentrations of serum inflammatory markers. Methods: This prospective clinical trial was conducted in 30 healthy Brazilian adults (15 women), aged 27.7 y (95% CI: 26.4, 29.1 y), with a body mass index (in kg/m 2 ) of 23.1 (95% CI: 22.0, 24.3). Blood was collected at baseline and after 45 and 90 d of the intervention. Serum folate concentrations were measured by microbiological assay and HPLC-tandem mass spectrometry [folate forms, including unmetabolized folic acid (UMFA)]. We used real-time polymerase chain reaction to assess mononuclear leukocyte mRNA expression and flow cytometry to measure the number and cytotoxicity of NK cells. Results: Serum folate concentrations increased by ∼5-fold after the intervention ( P 1.12 nmol/L) in 29 (96.6%) participants at day 45 and in 26 (86.7%) participants at day 90. We observed significant reductions in the number ( P < 0.001) and cytotoxicity ( P = 0.003) of NK cells after 45 and 90 d. Compared with baseline, DHFR mRNA expression was higher at 90 d ( P = 0.006) and IL8 and TNFA mRNA expressions were higher at 45 and 90 d ( P = 0.001 for both). Conclusion: This noncontrolled intervention showed that healthy adults responded to a high-dose FA supplement with increased UMFA concentrations, changes in cytokine mRNA expression, and reduced number and cytotoxicity of NK cells. This trial was registered at www.ensaiosclinicos.gov.br as RBR-2pr7zp. © 2017 American Society for Nutrition.

  20. Inhibition of NFκB by the natural product Withaferin A in cellular models of Cystic Fibrosis inflammation

    Directory of Open Access Journals (Sweden)

    Huang Shan

    2009-05-01

    Full Text Available Abstract Cystic Fibrosis (CF is one of the most common autosomal genetic disorders in humans. This disease is caused by mutations within a single gene, coding for the cystic fibrosis transmembrane conductance regulator (CFTR protein. The phenotypic hallmark of CF is chronic lung infection and associated inflammation from opportunistic microbes such as Pseudomonas aeruginosa (PA, Haemophilus influenzae, and Staphylococcus aureus. This eventually leads to deterioration of lung function and death in most CF patients. Unfortunately, there is no approved therapy for correcting the genetic defect causal to the disease. Hence, controlling inflammation and infection in CF patients are critical to disease management. Accordingly, anti-inflammatory agents and antibiotics are used to manage chronic inflammation and infection in CF patients. However, most of the anti-inflammatory agents in CF have severe limitations due to adverse side effects, and resistance to antibiotics is becoming an even more prominent problem. Thus, new agents that can be used to control chronic inflammation in CF are needed in the absence of a cure for the disease. Activation of the transcription factor NFκB through Toll-like receptors (TLR following bacterial infection is principally involved in regulating lung inflammation in CF. NFκB regulates the transcription of several genes that are involved in inflammation, anti-apoptosis and anti-microbial activity, and hyper-activation of this transcription factor leads to a potent inflammatory response. Thus, NFκB is a potential anti-inflammatory drug target in CF. Screening of several compounds from natural sources in an in vitro model of CF-related inflammation wherein NFκB is activated by filtrates of a clinically isolated strain of PA (PAF led us to Withaferin A (WFA, a steroidal lactone from the plant Withania Somnifera L. Dunal. Our data demonstrate that WFA blocks PAF-induced activation of NFκB as determined using reporter

  1. Inhibition of NFkappaB by the natural product Withaferin A in cellular models of Cystic Fibrosis inflammation.

    Science.gov (United States)

    Maitra, Rangan; Porter, Melissa A; Huang, Shan; Gilmour, Brian P

    2009-05-13

    Cystic Fibrosis (CF) is one of the most common autosomal genetic disorders in humans. This disease is caused by mutations within a single gene, coding for the cystic fibrosis transmembrane conductance regulator (CFTR) protein. The phenotypic hallmark of CF is chronic lung infection and associated inflammation from opportunistic microbes such as Pseudomonas aeruginosa (PA), Haemophilus influenzae, and Staphylococcus aureus. This eventually leads to deterioration of lung function and death in most CF patients. Unfortunately, there is no approved therapy for correcting the genetic defect causal to the disease. Hence, controlling inflammation and infection in CF patients are critical to disease management. Accordingly, anti-inflammatory agents and antibiotics are used to manage chronic inflammation and infection in CF patients. However, most of the anti-inflammatory agents in CF have severe limitations due to adverse side effects, and resistance to antibiotics is becoming an even more prominent problem. Thus, new agents that can be used to control chronic inflammation in CF are needed in the absence of a cure for the disease. Activation of the transcription factor NFkappaB through Toll-like receptors (TLR) following bacterial infection is principally involved in regulating lung inflammation in CF. NFkappaB regulates the transcription of several genes that are involved in inflammation, anti-apoptosis and anti-microbial activity, and hyper-activation of this transcription factor leads to a potent inflammatory response. Thus, NFkappaB is a potential anti-inflammatory drug target in CF. Screening of several compounds from natural sources in an in vitro model of CF-related inflammation wherein NFkappaB is activated by filtrates of a clinically isolated strain of PA (PAF) led us to Withaferin A (WFA), a steroidal lactone from the plant Withania Somnifera L. Dunal. Our data demonstrate that WFA blocks PAF-induced activation of NFkappaB as determined using reporter assays, IL

  2. Influence of immunomodulators of natural origin on cellular immunity indices in blood of broiler chicken under stress

    Directory of Open Access Journals (Sweden)

    S. Grabovskyi

    2015-03-01

    Full Text Available The paper deals with researching of T- and B-lymphocytes relative quantity and functional activity in broiler chicken blood after using of animal origin immunomodulators in conditions of pre-slaughter stress. The authors determined the relative amount of T- and B-lymphocytes and their individual populations in the reaction of spontaneous rоsetting with the sheep erythrocytes in blood. Besides, the differentiated count of rоsetting lymphocytes with the various degree of functional activity was conducted. The spleen extract (70% alcohol solution in volume of 1.4 ml per chicken was added to the diet of broiler chicken of experimental groups by aerosol method. This extract was obtained with/ without ultrasound application. 70% alcohol solution in the same volume and using the same method was added to the diet of broiler chicken of the control group five days before slaughter. The authors have not established probable increase of T-lymphocytes general quantity in broiler chicken blood in both experimental groups. It is shown that pre-slaughter stress in broiler chicken caused by weaning has immuno-suppressive effect on T- and B-lymphocytes in blood, which is accompanied by their quantity and functional activity decrease. T- and B-lymphocytes amount and functional activity of T- and B-cell immunity was stimulated after adding immunomodulators of natural origin to broiler chicken diet. Spleen extract polyamines as immunomodulators and antistressors most effectively influenced on some of cell immunity indices before slaughter – it is necessary to note the increase in T-helper lymphocytes in the broiler chickens blood caused by lymphocytes with medium (6–10 – by 18% (Р < 0.05 and high density receptors (М – by 35% (Р < 0.05 compared to the control. It is shown that decrease of T-lymphocytes quantity in broiler chicken blood is caused by lymphocytes with law (3–5 – by 22% (Р < 0.01 and high (M – by 11% (Р < 0.05 density receptors with

  3. Anti-Trypanosoma, anti-Leishmania and cytotoxic activities of natural products from Psidium brownianum Mart. ex DC. and Psidium guajava var. Pomifera analysed by LC-MS.

    Science.gov (United States)

    de Souza, Celestina Elba Sobral; da Silva, Ana Raquel Pereira; Gomez, Maria Celeste Vega; Rolóm, Míriam; Coronel, Cathia; da Costa, José Galberto Martins; Sousa, Amanda K; Rolim, Larissa A; de Souza, Francisco Hugo Sobral; Coutinho, Henrique Douglas Melo

    2017-12-01

    Neglected diseases are those that are prevalent in developing countries, even with a rich biodiversity. These diseases still persist because of the lack of scientific studies, government negligence or failures of the public health system. This study aims to identify the composition of extracts and fractions from Psidium brownianum and Psidium guajava through LC-MS, to evaluate its in vitro anti-parasitic and cytotoxic activity against Trypanosoma cruzi, Leishmania brasiliensis and L. infantum epismastigote and promastigote forms, as well as mammalian cells. The results showed the presence of chemical constituents in the two Psidium species as quercetin, myricetin and gallic acid derivatives. The P. brownianum extract and fractions showed low toxicity at all tested concentrations and all samples were effective at the concentration of 1000μg/mL against the parasites, with the extract being the most efficient against the L. infantum promastigote form. The ethanolic extract, and the flavonoid and tannic fractions, from P. guajava showed low toxicity for the fibroblasts. All samples showed effectiveness at the highest concentration tested and the extract was more effective against the promastigote forms tested. The results showed that the species Psidium brownianum and Psidium guajava demonstrated an anti-parasitic activity against the T. cruzi, L. brasiliensis and L. infantum parasite cell lines indicating these species as an alternative therapy given their efficacy in the in vitro assays performed, opening the possibility for new biological studies to further this knowledge through in vivo assays. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Antiplasmodial, cytotoxic activities and characterization of a new naturally occurring quinone methide pentacyclic triterpenoid derivative isolated from Salacia leptoclada Tul. (Celastraceae) originated from Madagascar.

    Science.gov (United States)

    Ruphin, Fatiany Pierre; Baholy, Robijaona; Emmanue, Andrianarivo; Amelie, Raharisololalao; Martin, Marie-Therese; Koto-te-Nyiwa, Ngbolua

    2013-10-01

    To validate scientifically the traditional use of Salacia leptoclada Tul. (Celastraceae) (S. leptoclada) and to isolate and elucidate the structure of the biologically active compound. Bioassay-guided fractionation of the acetonic extract of the stem barks of S. leptoclada was carried out by a combination of chromatography technique and biological experiments in viro using Plasmodium falciparum and P388 leukemia cell lines as models. The structure of the biologically active pure compound was elucidated by 1D and 2D NMR spectroscopy and mass spectrometry. Biological screening of S. leptoclada extracts resulted in the isolation of a pentacyclic triterpenic quinone methide. The pure compound exhibited both in vitro a cytotoxic effect on murine P388 leukemia cells with IC50 value of (0.041±0.020) μg/mL and an antiplasmodial activity against the chloroquine-resistant strain FC29 of Plasmodium falciparum with an IC50 value of (0.052±0.030) μg/mL. Despite this interesting anti-malarial property of the lead compound, the therapeutic index was weak (0.788). In the best of our knowledge, the quinone methide pentacyclic triterpenoid derivative compound is reported for the first time in S. leptoclada. The results suggest that furthers studies involving antineoplastic activity is needed for the development of this lead compound as anticancer drug. Copyright © 2013 Asian Pacific Tropical Biomedical Magazine. Published by Elsevier B.V. All rights reserved.

  5. Prevention of growth and metastasis of murine melanoma through enhanced natural-killer cytotoxicity by fatty acid-conjugate of protopanaxatriol.

    Science.gov (United States)

    Hasegawa, Hideo; Suzuki, Ryuichi; Nagaoka, Takema; Tezuka, Yasuhiro; Kadota, Shigetoshi; Saiki, Ikuo

    2002-07-01

    Ginsenosides, the glycosides of Panax ginseng, are metabolized (deglycosylated) by intestinal bacteria after oral administration. 20(S)-Protopanaxatriol (M4) is the main bacterial metabolite of protopanaxatriol-type ginsenosides and mediates their antitumor effects. To clarify the mechanism of the M4-mediated antitumor effect, the antitumor activity and metabolism of M4 was examined, using the C57BL/6 mice implanted with B16-BL6 melanoma. The chronic oral administration of M4 inhibited the growth of B16-BL6 melanoma at the implanted site. Analyses using TLC, HPLC, MS and NMR suggest that orally administered M4 was absorbed from the small intestine into the mesenteric lymphatics followed by the rapid esterification of M4 with fatty acids and its accumulation in the tissues including the liver and lung. The administration of M4 prior to the intravenous injection of B16-BL6 cells abrogated the enhanced lung metastasis in the mice pretreated with 2-chloroadenosine more effectively than in those pretreated with anti-asialo GM1. The esterified M4 (EM4) did not directly affect tumor growth in vitro, whereas it stimulated splenic NK cells to become cytotoxic to tumor cells. These results indicate that the antitumor activity of M4 is based on the NK cell-mediated tumor lysis enhanced by EM4.

  6. Daily intake of probiotics with high IFN-γ/IL-10 ratio increases the cytotoxicity of human natural killer cells: a personalized probiotic approach.

    Science.gov (United States)

    Ho, Yu-Hsuan; Lu, Yu-Chiu; Chang, Hung-Cheng; Lee, Shin-Yi; Tsai, Min-Fen; Huang, Yu-Ting; Hsu, Ting-Yuan

    2014-01-01

    A personalized probiotic microfluidic chip system has been established and used to screen the probiotics which had the highest value of IFN-γ/IL-10 or IL-10/IFN-γ among six probiotics, including L. paracasei BRAP01, L. acidophilus AD300, B. longum BA100, E. faecium BR0085, L. rhamnosus AD500, and L. reuteri BR101. One hundred volunteers were included and their PBMCs were collected and stimulated by the six probiotics. People who belonged to the IFN-γ group took the probiotics that exerted the highest ratio of IFN-γ/IL-10 and vice versa in IL-10 group. A significant increase in NK cytotoxicity of 69 volunteers in the IFN-γ group was observed compared to the IL-10 group (n = 21) and control group (n = 10). The result also showed that L. paracasei BRAP01 and L. acidophilus AD300 were the two dominant inducers in IFN-γ group which yielded higher value of IFN-γ/IL-10 than the other 4 probiotics, while L. reuteri BR101 was the most effective agent on the ratio of IL-10/IFN-γ in the IL-10 group. Our finding highlighted the concept of personalized probiotics and also provided a good foundation to investigate the probiotics with NK activity.

  7. Cellular gravity

    NARCIS (Netherlands)

    F.C. Gruau; J.T. Tromp (John)

    1999-01-01

    textabstractWe consider the problem of establishing gravity in cellular automata. In particular, when cellular automata states can be partitioned into empty, particle, and wall types, with the latter enclosing rectangular areas, we desire rules that will make the particles fall down and pile up on

  8. Molecular cytotoxic mechanisms of anticancer hydroxychalcones.

    Science.gov (United States)

    Sabzevari, Omid; Galati, Giuseppe; Moridani, Majid Y; Siraki, Arno; O'Brien, Peter J

    2004-06-30

    Chalcones are being considered as anticancer agents as they are natural compounds that are particularly cytotoxic towards K562 leukemia or melanoma cells. In this study, we have investigated phloretin, isoliquiritigenin, and 10 other hydroxylated chalcones for their cytotoxic mechanisms towards isolated rat hepatocytes. All hydroxychalcones partly depleted hepatocyte GSH and oxidized GSH to GSSG. These chalcones also caused a collapse of mitochondrial membrane potential and increased oxygen uptake. Furthermore, glycolytic or citric acid cycle substrates prevented cytotoxicity and mitochondrial membrane potential collapse. The highest pKa chalcones were the most effective at collapsing the mitochondrial membrane potential which suggests that the cytotoxic activity of hydroxychalcones are likely because of their ability to uncouple mitochondria.

  9. Cytotoxicity and intracellular dissolution of nickel nanowires

    KAUST Repository

    Perez, Jose E.

    2015-12-22

    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.

  10. Cytotoxicity and intracellular dissolution of nickel nanowires.

    Science.gov (United States)

    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.

  11. Cytotoxicity and intracellular dissolution of nickel nanowires

    KAUST Repository

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

    2015-01-01

    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.

  12. Acute pain induces an instant increase in natural killer cell cytotoxicity in humans and this response is abolished by local anaesthesia

    DEFF Research Database (Denmark)

    Greisen, J.; Hokland, Marianne; Grøfte, Thorbjørn

    1999-01-01

    We have investigated the effect of pain without tissue injury on natural killer (NK) cell activity in peripheral blood in humans and the effect of local anaesthesia on the response. Ten subjects were investigated during two sessions. First, self-controlled painful electric stimulation was applied...

  13. New palladium(II) and platinum(II) 5,5-diethylbarbiturate complexes with 2-phenylpyridine, 2,2'-bipyridine and 2,2'-dipyridylamine: synthesis, structures, DNA binding, molecular docking, cellular uptake, antioxidant activity and cytotoxicity.

    Science.gov (United States)

    Icsel, Ceyda; Yilmaz, Veysel T; Kaya, Yunus; Samli, Hale; Harrison, William T A; Buyukgungor, Orhan

    2015-04-21

    Novel palladium(ii) and platinum(ii) complexes of 5,5-diethylbarbiturate (barb) with 2-phenylpyridine (Hppy), 2,2'-bipyridine (bpy) and 2,2'-dipyridylamine (dpya) have been prepared and characterized by elemental analysis, IR, UV-Vis, NMR and ESI-MS. Single-crystal diffraction measurements show that complex consists of binuclear [Pd2(μ-barb-κN,O)2(ppy-κN,C)2] moieties, while complexes are mononuclear, [M(barb-κN)2(L-κN,N')] (L = bpy or dpya). has a composition of [Pt(dpya-κN,N')2][Ag(barb-κN)2]2·4H2O and was assumed to have a structure of [Pt(barb-κN)(Hppy-κN)(ppy-κN,C)]·3H2O. The complexes were found to exhibit significant DNA binding affinity by a non-covalent binding mode, in accordance with molecular docking studies. In addition, complexes and displayed strong binding with supercoiled pUC19 plasmid DNA. Cellular uptake studies were performed to assess the subcellular localization of the selected complexes. A moderate radical scavenging activity of and was confirmed by DPPH and ABTS tests. Complexes , , and showed selectivity against HT-29 (colon) cell line.

  14. Natural CD8{sup +}25{sup +} regulatory T cell-secreted exosomes capable of suppressing cytotoxic T lymphocyte-mediated immunity against B16 melanoma

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Yufeng; Zhang, Xueshu; Zhao, Tuo; Li, Wei; Xiang, Jim, E-mail: jim.xiang@saskcancer.ca

    2013-08-16

    Highlights: •CD8{sup +}25{sup +} regulatory T cells secrete tolerogenic exosomes. •CD8{sup +}25{sup +} regulatory T cell-derived exosomes exhibit immunosuppressive effect. •CD8{sup +}25{sup +} regulatory T cell-derived exosomes inhibit antitumor immunity. -- Abstract: Natural CD4{sup +}25{sup +} and CD8{sup +}25{sup +} regulatory T (Tr) cells have been shown to inhibit autoimmune diseases. Immune cells secrete exosomes (EXOs), which are crucial for immune regulation. However, immunomodulatory effect of natural Tr cell-secreted EXOs is unknown. In this study, we purified natural CD8{sup +}25{sup +} Tr cells from C57BL/6 mouse naive CD8{sup +} T cells, and in vitro amplified them with CD3/CD28 beads. EXOs (EXO{sub Tr}) were purified from Tr cell’s culture supernatants by differential ultracentrifugation and analyzed by electron microscopy, Western blot and flow cytometry. Our data showed that EXO{sub Tr} had a “saucer” or round shape with 50–100 nm in diameter, contained EXO-associated markers LAMP-1 and CD9, and expressed natural Tr cell markers CD25 and GITR. To assess immunomodulatory effect, we i.v. immunized C57BL/6 mice with ovalbumin (OVA)-pulsed DCs (DC{sub OVA}) plus Tr cells or EXO{sub Tr}, and then assessed OVA-specific CD8{sup +} T cell responses using PE-H-2K{sup b}/OVA tetramer and FITC-anti-CD8 antibody staining by flow cytometry and antitumor immunity in immunized mice with challenge of OVA-expressing BL6–10{sub OVA} melanoma cells. We demonstrated that DC{sub OVA}-stimulated CD8{sup +} T cell responses and protective antitumor immunity significantly dropped from 2.52% to 1.08% and 1.81% (p < 0.05), and from 8/8 to 2/8 and 5/8 mice DC{sub OVA} (p < 0.05) in immunized mice with co-injection of Tr cells and EXO{sub Tr}, respectively. Our results indicate that natural CD8{sup +}25{sup +} Tr cell-released EXOs, alike CD8{sup +}25{sup +} Tr cells, can inhibit CD8{sup +} T cell responses and antitumor immunity. Therefore, EXOs derived from

  15. Natural CD8+25+ regulatory T cell-secreted exosomes capable of suppressing cytotoxic T lymphocyte-mediated immunity against B16 melanoma

    International Nuclear Information System (INIS)

    Xie, Yufeng; Zhang, Xueshu; Zhao, Tuo; Li, Wei; Xiang, Jim

    2013-01-01

    Highlights: •CD8 + 25 + regulatory T cells secrete tolerogenic exosomes. •CD8 + 25 + regulatory T cell-derived exosomes exhibit immunosuppressive effect. •CD8 + 25 + regulatory T cell-derived exosomes inhibit antitumor immunity. -- Abstract: Natural CD4 + 25 + and CD8 + 25 + regulatory T (Tr) cells have been shown to inhibit autoimmune diseases. Immune cells secrete exosomes (EXOs), which are crucial for immune regulation. However, immunomodulatory effect of natural Tr cell-secreted EXOs is unknown. In this study, we purified natural CD8 + 25 + Tr cells from C57BL/6 mouse naive CD8 + T cells, and in vitro amplified them with CD3/CD28 beads. EXOs (EXO Tr ) were purified from Tr cell’s culture supernatants by differential ultracentrifugation and analyzed by electron microscopy, Western blot and flow cytometry. Our data showed that EXO Tr had a “saucer” or round shape with 50–100 nm in diameter, contained EXO-associated markers LAMP-1 and CD9, and expressed natural Tr cell markers CD25 and GITR. To assess immunomodulatory effect, we i.v. immunized C57BL/6 mice with ovalbumin (OVA)-pulsed DCs (DC OVA ) plus Tr cells or EXO Tr , and then assessed OVA-specific CD8 + T cell responses using PE-H-2K b /OVA tetramer and FITC-anti-CD8 antibody staining by flow cytometry and antitumor immunity in immunized mice with challenge of OVA-expressing BL6–10 OVA melanoma cells. We demonstrated that DC OVA -stimulated CD8 + T cell responses and protective antitumor immunity significantly dropped from 2.52% to 1.08% and 1.81% (p OVA (p Tr , respectively. Our results indicate that natural CD8 + 25 + Tr cell-released EXOs, alike CD8 + 25 + Tr cells, can inhibit CD8 + T cell responses and antitumor immunity. Therefore, EXOs derived from natural CD4 + 25 + and CD8 + 25 + Tr cells may become an alternative for immunotherapy of autoimmune diseases

  16. Toxicology and cellular effect of manufactured nanomaterials

    Science.gov (United States)

    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.

  17. Cytotoxic Compounds from Aloe megalacantha

    Directory of Open Access Journals (Sweden)

    Negera Abdissa

    2017-07-01

    Full Text Available Phytochemical investigation of the ethyl acetate extract of the roots of Aloe megalacantha led to the isolation of four new natural products—1,8-dimethoxynepodinol (1, aloesaponarin III (2, 10-O-methylchrysalodin (3 and methyl-26-O-feruloyl-oxyhexacosanate (4—along with ten known compounds. All purified metabolites were characterized by NMR, mass spectrometric analyses and comparison with literature data. The isolates were evaluated for their cytotoxic activity against a human cervix carcinoma cell line KB-3-1 and some of them exhibited good activity, with aloesaponarin II (IC50 = 0.98 µM being the most active compound.

  18. Task Group 7B: Cellular and Molecular Mechanisms of Biological Aging: The Roles of Nature, Nurture and Chance in the Maintenance of Human Healthspan

    Energy Technology Data Exchange (ETDEWEB)

    Weier, Heinz-Ulrich; Arya, Suresh; Grant, Christine; Miller, Linda; Ono, Santa Jeremy; Patil, Chris; Shay, Jerry; Topol, Eric; Torry, Michael; Weier, Heinz-Ulrich G.; Tse, Iris; Lin, Su-Ju; Miller, Richard

    2007-11-14

    The degree to which an individual organism maintains healthspan and lifespan is a function of complex interactions between genetic inheritance ('nature'), environment, including cultural inheritance (nurture) and stochastic events ('luck' or 'chance'). This task group will focus upon the role of chance because it is so poorly understood and because it appears to be of major importance in the determination of individual variations in healthspan and lifespan within species. The major factor determining variations in healthspan and lifespan between species is genetic inheritance. Broader aspects of cellular and molecular mechanisms of biological aging will also be considered, given their importance for understanding the cellular and molecular basis of successful aging. The task force will consider the cellular and molecular basis for nature, nurture and chance in healthspan and life span determination. On the basis of comparisons between identical and non-identical twins, geneticists have estimated that genes control no more than about a quarter of the inter-individual differences in lifespan (Herskind 1996). Twin studies of very old individuals, however, show substantially greater genetic contributions to Healthspan (McClearn 2004; Reed 2003). The environment clearly plays an important role in the length and the quality of life. Tobacco smoke, for example has the potential to impact upon multiple body systems in ways that appear to accelerate the rates at which those systems age (Bernhard 2007). To document the role of chance events on aging, one must rigorously control both the genetic composition of an organism and its environment. This has been done to a remarkable degree in a species of nematodes, Caenorhabditis elegans (Vanfleteren 1998). The results confirm hundreds of previous studies with a wide range of species, especially those with inbred rodents housed under apparently identical but less well controlled environments. One

  19. The New Cellular Immunology

    Science.gov (United States)

    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)

  20. Total asymmetric synthesis of the putative structure of the cytotoxic diterpenoid (-)-sclerophytin a and of the authentic natural sclerophytins A and B.

    Science.gov (United States)

    Bernardelli, P; Moradei, O M; Friedrich, D; Yang, J; Gallou, F; Dyck, B P; Doskotch, R W; Lange, T; Paquette, L A

    2001-09-19

    An enantioselective synthetic route to the thermodynamically most stable diastereomer of the structure assigned to sclerophytin A (5) has been realized. The required tricyclic ketone 33 was prepared by sequential Tebbe-Claisen rearrangement of lactones 29 and 30, which originated from the Diels-Alder cycloaddition of Danishefsky's diene to (5S)-5-(d-menthyloxy)-2(5H)-furanone (14). An allyl and a cyano group were introduced into the resulting adduct by means of stereocontrolled allylindation under aqueous Barbier-like conditions and by way of cyanotrimethylsilane, respectively. Following stereocontrolled nucleophilic addition of a methyl group to 33, ring A was elaborated by formation of the silyl enol ether, ytterbium triflate-catalyzed condensation with formaldehyde, O-silylation, and Cu(I)-promoted 1,4-addition of isopropylmagnesium chloride. The superfluous ketone carbonyl was subsequently removed and the second ether bridge introduced by means of oxymercuration chemistry. Only then was the exocyclic methylene group unmasked via elimination. An alternative approach to the alpha-carbinol diastereomer proceeds by initial alpha-oxygenation of 37 and ensuing 1,2-carbonyl transposition. Neither this series of steps nor the Wittig olefination to follow induced epimerization at C10. Through deployment of oxymercuration chemistry, it was again possible to elaborate the dual oxygen-bridge network of the target ring system. Oxidation of the organomercurial products with O(2) in the presence of sodium borohydride furnished 72, which was readily separated from its isomer 73 after oxidation to 61. Hydride attack on this ketone proceeded with high selectivity from the beta-direction to deliver (-)-60. Comparison of the high-field (1)H and (13)C NMR properties and polarity of synthetic 5 with natural material required that structural revision be made. Following a complete spectral reassessment of the structural assignments to many sclerophytin diterpenes, a general approach

  1. CD56 marks human dendritic cell subsets with cytotoxic potential

    NARCIS (Netherlands)

    Roothans, D.; Smits, E.; Lion, E.; Tel, J.; Anguille, S.

    2013-01-01

    Human plasmacytoid and myeloid dendritic cells (DCs), when appropriately stimulated, can express the archetypal natural killer (NK)-cell surface marker CD56. In addition to classical DC functions, CD56(+) DCs are endowed with an unconventional cytotoxic capacity.

  2. Monoclonal Antibodies, Derived from Humans Vaccinated with the RV144 HIV Vaccine Containing the HVEM Binding Domain of Herpes Simplex Virus (HSV) Glycoprotein D, Neutralize HSV Infection, Mediate Antibody-Dependent Cellular Cytotoxicity, and Protect Mice from Ocular Challenge with HSV-1.

    Science.gov (United States)

    Wang, Kening; Tomaras, Georgia D; Jegaskanda, Sinthujan; Moody, M Anthony; Liao, Hua-Xin; Goodman, Kyle N; Berman, Phillip W; Rerks-Ngarm, Supachai; Pitisuttithum, Punnee; Nitayapan, Sorachai; Kaewkungwal, Jaranit; Haynes, Barton F; Cohen, Jeffrey I

    2017-10-01

    The RV144 HIV vaccine trial included a recombinant HIV glycoprotein 120 (gp120) construct fused to a small portion of herpes simplex virus 1 (HSV-1) glycoprotein D (gD) so that the first 40 amino acids of gp120 were replaced by the signal sequence and the first 27 amino acids of the mature form of gD. This region of gD contains most of the binding site for HVEM, an HSV receptor important for virus infection of epithelial cells and lymphocytes. RV144 induced antibodies to HIV that were partially protective against infection, as well as antibodies to HSV. We derived monoclonal antibodies (MAbs) from peripheral blood B cells of recipients of the RV144 HIV vaccine and showed that these antibodies neutralized HSV-1 infection in cells expressing HVEM, but not the other major virus receptor, nectin-1. The MAbs mediated antibody-dependent cellular cytotoxicity (ADCC), and mice that received the MAbs and were then challenged by corneal inoculation with HSV-1 had reduced eye disease, shedding, and latent infection. To our knowledge, this is the first description of MAbs derived from human recipients of a vaccine that specifically target the HVEM binding site of gD. In summary, we found that monoclonal antibodies derived from humans vaccinated with the HVEM binding domain of HSV-1 gD (i) neutralized HSV-1 infection in a cell receptor-specific manner, (ii) mediated ADCC, and (iii) reduced ocular disease in virus-infected mice. IMPORTANCE Herpes simplex virus 1 (HSV-1) causes cold sores and neonatal herpes and is a leading cause of blindness. Despite many trials, no HSV vaccine has been approved. Nectin-1 and HVEM are the two major cellular receptors for HSV. These receptors are expressed at different levels in various tissues, and the role of each receptor in HSV pathogenesis is not well understood. We derived human monoclonal antibodies from persons who received the HIV RV144 vaccine that contained the HVEM binding domain of HSV-1 gD fused to HIV gp120. These antibodies were

  3. Cellular metabolism

    International Nuclear Information System (INIS)

    Hildebrand, C.E.; Walters, R.A.

    1977-01-01

    Progress is reported on the following research projects: chromatin structure; the use of circular synthetic polydeoxynucleotides as substrates for the study of DNA repair enzymes; human cellular kinetic response following exposure to DNA-interactive compounds; histone phosphorylation and chromatin structure in cell proliferation; photoaddition products induced in chromatin by uv light; pollutants and genetic information transfer; altered RNA metabolism as a function of cadmium accumulation and intracellular distribution in cultured cells; and thymidylate chromophore destruction by water free radicals

  4. Cytotoxicity of fluorographene

    Czech Academy of Sciences Publication Activity Database

    Teo, W. Z.; Sofer, Z.; Šembera, Filip; Janoušek, Zbyněk; Pumera, M.

    2015-01-01

    Roč. 5, č. 129 (2015), s. 107158-107165 ISSN 2046-2069 R&D Projects: GA ČR(CZ) GA15-09001S Institutional support: RVO:61388963 Keywords : fluorinated graphene * viability assays * cytotoxicity Subject RIV: CC - Organic Chemistry Impact factor: 3.289, year: 2015

  5. Evaluation of the cytotoxic and antimutagenic effects of biflorin, an antitumor 1,4 o-naphthoquinone isolated from Capraria biflora L.

    Science.gov (United States)

    Vasconcellos, Marne C; Moura, Dinara J; Rosa, Renato M; Machado, Miriana S; Guecheva, Temenouga N; Villela, Izabel; Immich, Bruna F; Montenegro, Raquel C; Fonseca, Aluísio M; Lemos, Telma L G; Moraes, Maria Elisabete A; Saffi, Jenifer; Costa-Lotufo, Letícia V; Moraes, Manoel O; Henriques, João A P

    2010-10-01

    Biflorin is a natural quinone isolated from Capraria biflora L. Previous studies demonstrated that biflorin inhibits in vitro and in vivo tumor cell growth and presents potent antioxidant activity. In this paper, we report concentration-dependent cytotoxic, genotoxic, antimutagenic, and protective effects of biflorin on Salmonella tiphymurium, yeast Saccharomyces cerevisiae, and V79 mammalian cells, using different approaches. In the Salmonella/microsome assay, biflorin was not mutagenic to TA97a TA98, TA100, and TA102 strains. However, biflorin was able to induce cytotoxicity in haploid S. cerevisiae cells in stationary and exponential phase growth. In diploid yeast cells, biflorin did not induce significant mutagenic and recombinogenic effects at the employed concentration range. In addition, the pre-treatment with biflorin prevented the mutagenic and recombinogenic events induced by hydrogen peroxide (H(2)O(2)) in S. cerevisiae. In V79 mammalian cells, biflorin was cytotoxic at higher concentrations. Moreover, at low concentrations biflorin pre-treatment protected against H(2)O(2)-induced oxidative damage by reducing lipid peroxidation and DNA damage as evaluated by normal and modified comet assay using DNA glycosylases. Our results suggest that biflorin cellular effects are concentration dependent. At lower concentrations, biflorin has significant antioxidant and protective effects against the cytotoxicity, genotoxicity, mutagenicity, and intracellular lipid peroxidation induced by H(2)O(2) in yeast and mammalian cells, which can be attributed to its hydroxyl radical-scavenging property. However, at higher concentrations, biflorin is cytotoxic and genotoxic.

  6. Curcumin-cyclodextrin encapsulated chitosan nanoconjugates with enhanced solubility and cell cytotoxicity.

    Science.gov (United States)

    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. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Study of Stevia rebaudiana Bertoni antioxidant activities and cellular properties.

    Science.gov (United States)

    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.

  8. Potentiation of luteolin cytotoxicity by flavonols fisetin and quercetin in human chronic lymphocytic leukemia cell lines.

    Science.gov (United States)

    Sak, Katrin; Kasemaa, Kristi; Everaus, Hele

    2016-09-14

    Despite numerous studies chronic lymphocytic leukemia (CLL) still remains an incurable disease. Therefore, all new compounds and novel strategies which are able to eradicate CLL cells should be considered as valuable clues for a potential future remedy against this malignancy. In the present study, the cytotoxic profiles of natural flavonoids were described in two human CLL cell lines, HG-3 and EHEB, indicating the flavone luteolin as the most potent flavonoid with half-maximal inhibitory constants (IC50) of 37 μM and 26 μM, respectively. Luteolin significantly increased the apoptotic cell population in both cell lines by increasing the activities of caspases-3 and -9 and triggering the intrinsic apoptotic pathway. Two flavonols, fisetin and quercetin, were somewhat less efficient in suppressing cellular viability, whereas baicalein, chrysin, (+)-catechin and hesperetin exerted only a small or no response at doses as high as 100 μM. Both fisetin and quercetin were able to augment the cytotoxic activity of luteolin in both cell lines by reducing the IC50 values up to four fold. As a result of this, luteolin displayed cytotoxicity activity already at low micromolar concentrations that could potentially be physiologically achievable through oral ingestion. No other tested flavonoids were capable of sensitizing CLL cells to luteolin pointing to a specific binding of fisetin and quercetin to the cellular targets which interfere with the signaling pathways induced by luteolin. Although further molecular studies to unravel this potentiating mechanism are certainly needed, this phenomenon could contribute to future remedies for prevention and treatment of chronic lymphocytic leukemia.

  9. Ni(ii)/Cu(ii)/Zn(ii) 5,5-diethylbarbiturate complexes with 1,10-phenanthroline and 2,2'-dipyridylamine: synthesis, structures, DNA/BSA binding, nuclease activity, molecular docking, cellular uptake, cytotoxicity and the mode of cell death.

    Science.gov (United States)

    Yilmaz, Veysel T; Icsel, Ceyda; Suyunova, Feruza; Aygun, Muhittin; Aztopal, Nazlihan; Ulukaya, Engin

    2016-06-21

    New 5,5-diethylbarbiturate (barb) complexes of Ni(ii), Cu(ii) and Zn(ii) with 1,10-phenanthroline (phen) and 2,2'-dipyridylamine (dpya), namely [Ni(phen-κN,N')3]Cl(barb)·7H2O (), [Cu(barb-κN)(barb-κ(2)N,O)(phen-κN,N')]·H2O (), [Cu(barb-κN)2(phen-κN,N')] (), [Zn(barb-κN)2(phen-κN,N')]·H2O (), [Ni(barb-κ(2)N,O)(dpya-κN,N')2]Cl·2H2O (), [Cu(barb-κ(2)N,O)2(dpya-κN,N')]·2H2O () and [Zn(barb-κN)2(dpya-κN,N')] (), were synthesized and characterized by elemental analysis, UV-vis, FT-IR and ESI-MS. The structures of the complexes were determined by X-ray crystallography. Notably, and were fluorescent in MeOH : H2O at rt. The interaction of the complexes with fish sperm (FS) DNA and bovine serum albumin (BSA) was investigated in detail by various techniques. The complexes exhibited groove binding along with a partial intercalative interaction with DNA, while the hydrogen bonding and hydrophobic interactions played a major role in binding to BSA. It is noteworthy that exhibited the highest affinity towards DNA and BSA. Enzyme inhibition assay showed that show a preference for both A/T and G/C rich sequences in pUC19 DNA, while and display a binding specificity to the G/C and A/T rich regions, respectively. These findings were further supported by molecular docking. The cellular uptake studies suggested that was deposited mostly in the membrane fraction of the cells. Among the present complexes, exhibited a very strong cytotoxic effect on A549, MCF-7, HT-29 and DU-145 cancer cells, being more potent than cisplatin. Moreover, induces cell death through the apoptotic mode obtained by flow cytometry.

  10. Electromagnetic cellular interactions.

    Science.gov (United States)

    Cifra, Michal; Fields, Jeremy Z; Farhadi, Ashkan

    2011-05-01

    Chemical and electrical interaction within and between cells is well established. Just the opposite is true about cellular interactions via other physical fields. The most probable candidate for an other form of cellular interaction is the electromagnetic field. We review theories and experiments on how cells can generate and detect electromagnetic fields generally, and if the cell-generated electromagnetic field can mediate cellular interactions. We do not limit here ourselves to specialized electro-excitable cells. Rather we describe physical processes that are of a more general nature and probably present in almost every type of living cell. The spectral range included is broad; from kHz to the visible part of the electromagnetic spectrum. We show that there is a rather large number of theories on how cells can generate and detect electromagnetic fields and discuss experimental evidence on electromagnetic cellular interactions in the modern scientific literature. Although small, it is continuously accumulating. Copyright © 2010 Elsevier Ltd. All rights reserved.

  11. Cytotoxicity potentials of eleven Bangladeshi medicinal plants.

    Science.gov (United States)

    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.

  12. Cytotoxicity Potentials of Eleven Bangladeshi Medicinal Plants

    Directory of Open Access Journals (Sweden)

    Amina Khatun

    2014-01-01

    Full Text Available 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.

  13. An intrinsic poperty of memory of the Cellular automaton infrastructure of Nature leading to the organization of the physical world as an Internet o things; TOE = IOT

    Science.gov (United States)

    Berkovich, Simon

    2015-04-01

    The undamental advantage of a Cellular automaton construction foris that it can be viewed as an undetectable absolute frame o reference, in accordance with Lorentz-Poincare's interpretation.. The cellular automaton model for physical poblems comes upon two basic hurdles: (1) How to find the Elemental Rule that, and how to get non-locality from local transformations. Both problems are resolved considering the transfomation rule of mutual distributed synchronization Actually any information proessing device starts with a clocking system. and it turns out that ``All physical phenomena are different aspects of the high-level description of distributed mutual synchronization in a network of digital clocks''. Non-locality comes from two hugely different time-scales of signaling.. The universe is acombinines information and matter processes, These fast spreading diffusion wave solutions create the mechanism of the Holographic Universe. And thirdly Disengaged from synchronization, circular counters can perform memory functions by retaining phases of their oscillations, an idea of Von Neumann'. Thus, the suggested model generates the necessary constructs for the physical world as an Internet of Things. Life emerges due to the specifics of macromolecules that serve as communication means, with the holographic memory...

  14. natural

    Directory of Open Access Journals (Sweden)

    Elías Gómez Macías

    2006-01-01

    Full Text Available Partiendo de óxido de magnesio comercial se preparó una suspensión acuosa, la cual se secó y calcinó para conferirle estabilidad térmica. El material, tanto fresco como usado, se caracterizó mediante DRX, área superficial BET y SEM-EPMA. El catalizador mostró una matriz de MgO tipo periclasa con CaO en la superficie. Las pruebas de actividad catalítica se efectuaron en lecho fijo empacado con partículas obtenidas mediante prensado, trituración y clasificación del material. El flujo de reactivos consistió en mezclas gas natural-aire por debajo del límite inferior de inflamabilidad. Para diferentes flujos y temperaturas de entrada de la mezcla reactiva, se midieron las concentraciones de CH4, CO2 y CO en los gases de combustión con un analizador de gases tipo infrarrojo no dispersivo (NDIR. Para alcanzar conversión total de metano se requirió aumentar la temperatura de entrada al lecho a medida que se incrementó el flujo de gases reaccionantes. Los resultados obtenidos permiten desarrollar un sistema de combustión catalítica de bajo costo con un material térmicamente estable, que promueva la alta eficiencia en la combustión de gas natural y elimine los problemas de estabilidad, seguridad y de impacto ambiental negativo inherentes a los procesos de combustión térmica convencional.

  15. Autonomously bioluminescent mammalian cells for continuous and real-time monitoring of cytotoxicity.

    Science.gov (United States)

    Xu, Tingting; Close, Dan M; Webb, James D; Ripp, Steven A; Sayler, Gary S

    2013-10-28

    Mammalian cell-based in vitro assays have been widely employed as alternatives to animal testing for toxicological studies but have been limited due to the high monetary and time costs of parallel sample preparation that are necessitated due to the destructive nature of firefly luciferase-based screening methods. This video describes the utilization of autonomously bioluminescent mammalian cells, which do not require the destructive addition of a luciferin substrate, as an inexpensive and facile method for monitoring the cytotoxic effects of a compound of interest. Mammalian cells stably expressing the full bacterial bioluminescence (luxCDABEfrp) gene cassette autonomously produce an optical signal that peaks at 490 nm without the addition of an expensive and possibly interfering luciferin substrate, excitation by an external energy source, or destruction of the sample that is traditionally performed during optical imaging procedures. This independence from external stimulation places the burden for maintaining the bioluminescent reaction solely on the cell, meaning that the resultant signal is only detected during active metabolism. This characteristic makes the lux-expressing cell line an excellent candidate for use as a biosentinel against cytotoxic effects because changes in bioluminescent production are indicative of adverse effects on cellular growth and metabolism. Similarly, the autonomous nature and lack of required sample destruction permits repeated imaging of the same sample in real-time throughout the period of toxicant exposure and can be performed across multiple samples using existing imaging equipment in an automated fashion.

  16. Algorithm for cellular reprogramming.

    Science.gov (United States)

    Ronquist, Scott; Patterson, Geoff; Muir, Lindsey A; Lindsly, Stephen; Chen, Haiming; Brown, Markus; Wicha, Max S; Bloch, Anthony; Brockett, Roger; Rajapakse, Indika

    2017-11-07

    The day we understand the time evolution of subcellular events at a level of detail comparable to physical systems governed by Newton's laws of motion seems far away. Even so, quantitative approaches to cellular dynamics add to our understanding of cell biology. With data-guided frameworks we can develop better predictions about, and methods for, control over specific biological processes and system-wide cell behavior. Here we describe an approach for optimizing the use of transcription factors (TFs) in cellular reprogramming, based on a device commonly used in optimal control. We construct an approximate model for the natural evolution of a cell-cycle-synchronized population of human fibroblasts, based on data obtained by sampling the expression of 22,083 genes at several time points during the cell cycle. To arrive at a model of moderate complexity, we cluster gene expression based on division of the genome into topologically associating domains (TADs) and then model the dynamics of TAD expression levels. Based on this dynamical model and additional data, such as known TF binding sites and activity, we develop a methodology for identifying the top TF candidates for a specific cellular reprogramming task. Our data-guided methodology identifies a number of TFs previously validated for reprogramming and/or natural differentiation and predicts some potentially useful combinations of TFs. Our findings highlight the immense potential of dynamical models, mathematics, and data-guided methodologies for improving strategies for control over biological processes. Copyright © 2017 the Author(s). Published by PNAS.

  17. Cytotoxicity Testing: Cell Experiments

    Science.gov (United States)

    Grünert, Renate; Westendorf, Aron; Buczkowska, Magdalena; Hänsch, Mareike; Grüunert, Sybil; Bednarski, Patrick J.

    Screening for new anticancer agents has traditionally been done with in vitro cell culture methods. Even in the genomic era of target-driven drug design, screening for cytotoxic activity is still a standard tool in the search for new anticancer agents, especially if the mode of action of a substance is not yet known. A wide variety of cell culture methods with unique end-points are available for testing the anticancer potential of a substance. Each has its advantages and disadvantages, which must be weighed in the decision to use a particular method. Often several complementary methods are used to gain information on the mode of action of a substance.

  18. Cytotoxicity of Cheese and Cheddar Cheese food flavorings on Allim cepa L root meristems

    Directory of Open Access Journals (Sweden)

    A. G. Moura

    Full Text Available Abstract 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.

  19. Cellular dosimetry

    International Nuclear Information System (INIS)

    Humm, J.L.; Chin, L.M.

    1989-01-01

    Radiation dose is a useful predictive parameter for describing radiation toxicity in conventional radiotherapy. Traditionally, in vitro radiation biology dose-effect relations are expressed in the form of cell survival curves, a semilog plot of cell survival versus dose. However, the characteristic linear or linear quadratic survival curve shape, for high- and low-LET radiations respectively, is only strictly valid when the radiation dose is uniform across the entire target population. With an external beam of 60 Co gamma rays or x-rays, a uniform field may be readily achievable. When radionuclides are incorporated into a cell milieu, several new problems emerge which can result in a departure from uniformity in energy deposition throughout a cell population. This nonuniformity can have very important consequences for the shape of the survival curve. Cases in which perturbations of source uniformity may arise include: 1. Elemental sources may equilibrate in the cell medium with partition coefficients between the extracellular, cytosol, and nuclear compartments. The effect of preferential cell internalization or binding to cell membrane of some radionuclides can increase or decrease the slope of the survival curve. 2. Radionuclides bound to antibodies, hormones, metabolite precursors, etc., may result in a source localization pattern characteristic of the carrier agent, i.e., the sources may bind to cell surface receptors or antigens, be internalized, bind to secreted antigen concentrated around a fraction of the cell population, or become directly incorporated into the cell DNA. We propose to relate the distribution of energy deposition in cell nuclei to biological correlates of cellular inactivation. The probability of each cell's survival is weighted by its individual radiation burden, and the summation of these probabilities for the cell population can be used to predict the number or fraction of cell survivors

  20. Reducing ZnO nanoparticle cytotoxicity by surface modification.

    Science.gov (United States)

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

    2014-06-07

    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.

  1. Cytotoxicity of Phenol Red in Toxicity Assays for Carbon Nanoparticles

    Directory of Open Access Journals (Sweden)

    Chunhai Fan

    2012-09-01

    Full Text Available To explore the novel properties of carbon nanoparticles (CNPs in nanotoxicity assays, the adsorption of phenol red (a pH indicator for culture medium by multi-walled carbon nanotubes (MWNTs and three kinds of carbon blacks (CBs with nanosize, and its effects on cytotoxicity were studied. Results indicated that the phenol red adsorbed and delivered into cells by CBs was responsible for the toxicity to Hela cells in the medium without serum. The cellular uptake of phenol red was verified using 125I-labeling techniques. The size-dependent cytotoxicity of CBs was found to closely correlate to adsorption of phenol red, cellular uptake of phenol red-CB complexes and the amount of phenol red delivered into the cells by CBs. Although the CBs were either nontoxic or slightly toxic, as vehicles of phenol red, they played an essential role in the cytotoxicity induced by phenol red. However, MWNTs showed an intrinsic cytotoxicity independent of phenol red. The implications associated with these findings are discussed.

  2. Supplementary Material for: Cytotoxicity and intracellular dissolution of nickel nanowires

    KAUST Repository

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

    2016-01-01

    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.

  3. Analysis of cytotoxic effects of nickel on human blood lymphocytes.

    Science.gov (United States)

    Zarei, Mohammad Hadi; Hosseini Shirazi, Seyed Farshad; Aghvami, Marjan; Salimi, Ahmad; Pourahmad, Jalal

    2018-02-01

    Nickel compounds possess many applications in different industrial processes. Human beings are exposed to nickel commonly through occupational exposure and food. Although a few studies so far have investigated the effects of nickel compounds on human lymphocytes, the complete mechanism of cytotoxicity of this metal on human lymphocytes is yet to be determined. The intention of this paper was to determine the cytotoxicity mechanism of water soluble NiCl 2 toward human lymphocytes using the accelerated cytotoxicity mechanisms screening (ACMS) technique. Human lymphocytes were isolated from the blood of healthy subjects based on Ficoll-Paque PLUS standard method. For the assessment of cell viability, lymphocytes were incubated with 0.05-1 mM NiCl 2 for 12 h. Determination of mechanistic parameters was performed 2, 4 and 6 h after treatment of cells with ½ EC50 12h , EC50 12h and 2EC50 12h of NiCl 2 . Our results demonstrate that cytotoxicity of NiCl 2 on human lymphocytes is associated with increased ROS formation, mitochondrial membrane potential collapse, glutathione depletion, lysosomal membrane damage, cellular proteolysis and activation of caspase-3 before cytotoxicity ensued.

  4. Paramecium aurelia as a cellular model used for studies of the biological effects of natural ionizing radiation or chronic low-level irradiation

    International Nuclear Information System (INIS)

    Planel, H.; Soleilhavoup, J.P.; Tixador, R.; Croute, F.; Richoilley, G.

    1979-01-01

    Paramecium aurelia appears to be a very suitable object for investigating the biological effects of natural ionizing radiation or the influence of low doses of radiation. The biological effects of ionizing radiation on cell proliferation kinetics were tested. It is shown that radio-protection or chronic exposure to very low doses of 60 Co gamma rays induce different changes in cell growth rate. Special experimental techniques can help to obtain more obvious results using cells more sensitive to the stimulating effects of low doses of ionizing radiation. (author)

  5. Enantioselective Cytotoxicity Profile of o,p’-DDT in PC 12 Cells

    Science.gov (United States)

    Zhang, Chunlong; Wen, Yuezhong; Liu, Weiping

    2012-01-01

    Background The continued uses of dichlordiphenyltrichloroethane (DDT) for indoor vector control in some developing countries have recently fueled intensive debates toward the global ban of this persistent legacy contaminant. Current approaches for ecological and health risk assessment has ignored the chiral nature of DDT. In this study by employing an array of cytotoxicity related endpoints, we investigated the enantioselective cytotoxicity of o,p’-DDT. Principal Findings we demonstrated for the first time that R-(−)-o,p’-DDT caused more neuron cell death by inducing more severe oxidative stress, which selectively imbalanced the transcription of stress-related genes (SOD1, SOD2, HSP70) and enzyme (superoxide dismutase and lactate dehydrogenase) activities, and greater cellular apoptosis compared to its enantiomer S-(+)-o,p’-DDT at the level comparable to malaria area exposure (parts per million). We further elucidated enantioselective modes of action using microarray combined with enzyme-linked immunosorbent assay. The enantioselective apoptosis might involve three signaling pathways via caspase 3, tumor protein 53 (p53) and NFkB. Conclusions Based on DDT stereochemistry and results reported for other chiral pesticides, our results pointed to the same directional enantioselectivity of chiral DDT toward mammalian cells. We proposed that risk assessment on DDT should consider the enantiomer ratio and enantioselectivities. PMID:22937105

  6. Involvement of enniatins-induced cytotoxicity in human HepG2 cells.

    Science.gov (United States)

    Juan-García, Ana; Manyes, Lara; Ruiz, María-José; Font, Guillermina

    2013-04-12

    Enniatins (ENNs) are mycotoxins found in Fusarium fungi and they appear in nature as mixtures of cyclic depsipeptides. The ability to form ionophores in the cell membrane is related to their cytotoxicity. Changes in ion distribution between inner and outer phases of the mitochondria affect to their metabolism, proton gradient, and chemiosmotic coupling, so a mitochondrial toxicity analysis of enniatins is highly recommended because they host the homeostasis required for cellular survival. Two ENNs, ENN A and ENN B on hepatocarcinoma cells (HepG2) at 1.5 and 3 μM and three exposure times (24, 48 and 72 h) were studied. Flow cytometry was used to examine their effects on cell proliferation, to characterize at which phase of the cell cycle progression the cells were blocked and to study the role of the mitochondrial in ENNs-induced apoptosis. In conclusion, apoptosis induction on HepG2 cells allowed to compare cytotoxic effects caused by both ENNs, A and B. It is reported the possible mechanism observed in MMP changes, cell cycle analysis and apoptosis/necrosis, identifying ENN B more toxic than ENN A. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  7. Characterization of CD4+ T cell-mediated cytotoxicity in patients with multiple myeloma.

    Science.gov (United States)

    Zhang, Xiaole; Gao, Lei; Meng, Kai; Han, Chunting; Li, Qiang; Feng, Zhenjun; Chen, Lei

    2018-05-01

    Multiple myeloma (MM) is an incurable cancer characterized by the development of malignant plasma cells. The CD8 T cell-mediated cytotoxicity is considered a major player in antitumor immunity, but in MM patients, the CD8 T cells displayed senescence markers and were functionally impaired. To investigate whether cytotoxic CD4 T cells could act as a treatment alternative in MM, we examined the frequency and function of naturally occurring cytotoxic CD4 T cells in MM patients. The cytotoxic CD4 T cells were identified as granzyme-A, granzyme B-, and perforin-expressing CD4 T cells, and their frequencies were significantly upregulated in MM patients when compared with healthy controls. The frequencies of cytotoxic CD4 T cells in MM patients were not associated with the frequencies of cytotoxic CD8 T cells, but were negatively associated with disease severity. Interestingly, the expression levels of inhibitory molecules, including PD-1 and CTLA-4, were significantly lower in cytotoxic CD4 T cells than in cytotoxic CD8 T cells. When co-incubated with autologous CD38 + CD138 + plasma cells, CD4 T cells were capable of eliminating plasma cells with varying degrees of efficacy. In MM patients, the frequency of circulating plasma cells was negatively correlated with the frequency of cytotoxic CD4 T cells. Therefore, CD4 T cell-mediated cytotoxicity existed naturally in MM patients and could potentially act as an option in antitumor therapies. Copyright © 2018 Elsevier Inc. All rights reserved.

  8. Isotope release cytotoxicity assay applicable to human tumors: the use of 111-indium

    Energy Technology Data Exchange (ETDEWEB)

    Frost, P; Wiltrout, R; Maciorowski, Z; Rose, N R

    1977-01-01

    We have demonstrated that human tumors can be labelled efficiently with the 111indium-oxine chelate. Subsequently, this isotope can be released by cytotoxic lymphoid cells. Both natural and induced cytotoxicity can be demonstrated utilizing this isotope release method. Because of the slow spontaneous release of 111indium and its efficient labelling of human tumor cells, this isotope release assay can be utilized in long-term cytotoxic assays in the study of human tumor immunology.

  9. Are diamond nanoparticles cytotoxic?

    Science.gov (United States)

    Schrand, Amanda M; Huang, Houjin; Carlson, Cataleya; Schlager, John J; Omacr Sawa, Eiji; Hussain, Saber M; Dai, Liming

    2007-01-11

    Finely divided carbon particles, including charcoal, lampblack, and diamond particles, have been used for ornamental and official tattoos since ancient times. With the recent development in nanoscience and nanotechnology, carbon-based nanomaterials (e.g., fullerenes, nanotubes, nanodiamonds) attract a great deal of interest. Owing to their low chemical reactivity and unique physical properties, nanodiamonds could be useful in a variety of biological applications such as carriers for drugs, genes, or proteins; novel imaging techniques; coatings for implantable materials; and biosensors and biomedical nanorobots. Therefore, it is essential to ascertain the possible hazards of nanodiamonds to humans and other biological systems. We have, for the first time, assessed the cytotoxicity of nanodiamonds ranging in size from 2 to 10 nm. Assays of cell viability such as mitochondrial function (MTT) and luminescent ATP production showed that nanodiamonds were not toxic to a variety of cell types. Furthermore, nanodiamonds did not produce significant reactive oxygen species. Cells can grow on nanodiamond-coated substrates without morphological changes compared to controls. These results suggest that nanodiamonds could be ideal for many biological applications in a diverse range of cell types.

  10. High-content, high-throughput screening for the identification of cytotoxic compounds based on cell morphology and cell proliferation markers.

    Directory of Open Access Journals (Sweden)

    Heather L Martin

    Full Text Available Toxicity is a major cause of failure in drug discovery and development, and whilst robust toxicological testing occurs, efficiency could be improved if compounds with cytotoxic characteristics were identified during primary compound screening. The use of high-content imaging in primary screening is becoming more widespread, and by utilising phenotypic approaches it should be possible to incorporate cytotoxicity counter-screens into primary screens. Here we present a novel phenotypic assay that can be used as a counter-screen to identify compounds with adverse cellular effects. This assay has been developed using U2OS cells, the PerkinElmer Operetta high-content/high-throughput imaging system and Columbus image analysis software. In Columbus, algorithms were devised to identify changes in nuclear morphology, cell shape and proliferation using DAPI, TOTO-3 and phosphohistone H3 staining, respectively. The algorithms were developed and tested on cells treated with doxorubicin, taxol and nocodazole. The assay was then used to screen a novel, chemical library, rich in natural product-like molecules of over 300 compounds, 13.6% of which were identified as having adverse cellular effects. This assay provides a relatively cheap and rapid approach for identifying compounds with adverse cellular effects during screening assays, potentially reducing compound rejection due to toxicity in subsequent in vitro and in vivo assays.

  11. Antioxidant Activity of Lawsonia inermis Extracts Inhibits Chromium(VI-Induced Cellular and DNA Toxicity

    Directory of Open Access Journals (Sweden)

    Gunjan Guha

    2011-01-01

    Full Text Available Hexavalent chromium Cr(VI is a very strong oxidant which consequently causes high cytotoxicity through oxidative stress. Prevention of Cr(VI-induced cellular damage has been sought in this study in aqueous and methanolic extracts of Lawsonia inermis Linn. (Lythraceae, commonly known as Henna. The extracts showed significant (P < .05 potential in scavenging free radicals (DPPH• and ABTS•+ and Fe3+, and in inhibiting lipid peroxidation. DNA damage caused by exposure of pBR322 to Cr(VI-UV is markedly inhibited by both extracts in varying degrees. A distinct decline in Cr(VI-induced cytotoxicity was noticed in MDA-MB-435S (human breast carcinoma cells with an increase in dosage of both extracts individually. Furthermore, both extracts proved to contain a high content of phenolic compounds which were found to have a strong and significant (P < .05 positive correlation to the radical scavenging potential, lipid peroxidation inhibition capacity and cyto-protective efficiency against Cr(VI-induced oxidative cellular damage. HPLC analysis identified some of the major phenolic compounds in both extracts, which might be responsible for the antioxidant potential and the properties of DNA and cyto-protection. This study contributes to the search for natural resources that might yield potent therapeutic drugs against Cr(VI-induced oxidative cell damage.

  12. Novel molecular, cytotoxical, and immunological study on promising and selective anticancer activity of Mung bean sprouts

    Directory of Open Access Journals (Sweden)

    Hafidh Rand R

    2012-11-01

    Full Text Available Abstract Background The anticancer and immunomodulatory activity of mung bean sprouts (MBS and the underlying mechanisms against human cervical and hepatocarcinoma cancer cells were explored. Methods MBS cytotoxicity and MBS-induced anticancer cytokines, TNF-α and IFN-β from cancer cells, and immunological cytokines, IL-4, IFN-γ, and IL-10 from peripheral mononuclear cells (PMNC were assessed by MTS and ELISA assays. Apoptotic cells were investigated by flow cytometry. The expression level of apoptotic genes (Bax, BCL-2, Capsases 7–9 and cell cycle regulatory genes (cyclin D, E, and A and tumor suppressor proteins (p27, p21, and p53 was assessed by real-time qPCR in the cancer cells treated with extract IC50. Results The cytotoxicity on normal human cells was significantly different from HeLa and HepG2 cells, 163.97 ± 5.73, 13.3 ± 0.89, and 14.04 ± 1.5 mg/ml, respectively. The selectivity index (SI was 12.44 ± 0.83 for HeLa and 11.94 ± 1.2 for HepG2 cells. Increased levels of TNF-α and IFN-β were observed in the treated HeLa and HepG2 culture supernatants when compared with untreated cells. MBS extract was shown to be an immunopolarizing agent by inducing IFNγ and inhibiting IL-4 production by PBMC; this leads to triggering of CMI and cellular cytotoxicity. The extract induced apoptosis, in a dose and time dependent manner, in treated HeLa and HepG2, but not in untreated, cells (P Conclusion MBS extract was shown to be a potent anticancer agent granting new prospects of anticancer therapy using natural products.

  13. The potential of mycelium and culture broth of Lignosus rhinocerotis as substitutes for the naturally occurring sclerotium with regard to antioxidant capacity, cytotoxic effect, and low-molecular-weight chemical constituents.

    Directory of Open Access Journals (Sweden)

    Beng Fye Lau

    Full Text Available Previous studies on the nutritional and nutraceutical properties of Lignosus rhinocerotis focused mainly on the sclerotium; however, the supply of wild sclerotium is limited. In this investigation, the antioxidant capacity and cytotoxic effect of L. rhinocerotis cultured under different conditions of liquid fermentation (shaken and static were compared to the sclerotium produced by solid-substrate fermentation. Aqueous methanol extracts of the mycelium (LR-MH, LR-MT and culture broth (LR-BH, LR-BT demonstrated either higher or comparable antioxidant capacities to the sclerotium extract (LR-SC based on their radical scavenging abilities, reducing properties, metal chelating activities, and inhibitory effects on lipid peroxidation. All extracts exerted low cytotoxicity (IC50>200 µg/ml, 72 h against selected mammalian cell lines. Several low-molecular-weight compounds, including sugars, fatty acids, methyl esters, sterols, amides, amino acids, phenolics, and triterpenoids, were identified using GC-MS and UHPLC-ESI-MS/MS. The presence of proteins (<40 kDa in the extracts was confirmed by SDS-PAGE and SELDI-TOF-MS. Principal component analysis revealed that the chemical profiles of the mycelial extracts under shaken and static conditions were distinct from those of the sclerotium. Results from bioactivity evaluation and chemical profiling showed that L. rhinocerotis from liquid fermentation merits consideration as an alternative source of functional ingredients and potential substitute for the sclerotium.

  14. Dysregulated cellular functions and cell stress pathways provide critical cues for activating and targeting natural killer cells to transformed and infected cells.

    Science.gov (United States)

    Raulet, David H; Marcus, Assaf; Coscoy, Laurent

    2017-11-01

    Natural killer (NK) cells recognize and kill cancer cells and infected cells by engaging cell surface ligands that are induced preferentially or exclusively on these cells. These ligands are recognized by activating receptors on NK cells, such as NKG2D. In addition to activation by cell surface ligands, the acquisition of optimal effector activity by NK cells is driven in vivo by cytokines and other signals. This review addresses a developing theme in NK cell biology: that NK-activating ligands on cells, and the provision of cytokines and other signals that drive high effector function in NK cells, are driven by abnormalities that arise from transformation or the infected state. The pathways include genomic damage, which causes self DNA to be exposed in the cytosol of affected cells, where it activates the DNA sensor cGAS. The resulting signaling induces NKG2D ligands and also mobilizes NK cell activation. Other key pathways that regulate NKG2D ligands include PI-3 kinase activation, histone acetylation, and the integrated stress response. This review summarizes the roles of these pathways and their relevance in both viral infections and cancer. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. Vascular Wall-Resident Multipotent Stem Cells of Mesenchymal Nature within the Process of Vascular Remodeling: Cellular Basis, Clinical Relevance, and Implications for Stem Cell Therapy.

    Science.gov (United States)

    Klein, Diana

    2016-01-01

    Until some years ago, the bone marrow and the endothelial cell compartment lining the vessel lumen (subendothelial space) were thought to be the only sources providing vascular progenitor cells. Now, the vessel wall, in particular, the vascular adventitia, has been established as a niche for different types of stem and progenitor cells with the capacity to differentiate into both vascular and nonvascular cells. Herein, vascular wall-resident multipotent stem cells of mesenchymal nature (VW-MPSCs) have gained importance because of their large range of differentiation in combination with their distribution throughout the postnatal organism which is related to their existence in the adventitial niche, respectively. In general, mesenchymal stem cells, also designated as mesenchymal stromal cells (MSCs), contribute to the maintenance of organ integrity by their ability to replace defunct cells or secrete cytokines locally and thus support repair and healing processes of the affected tissues. This review will focus on the central role of VW-MPSCs within vascular reconstructing processes (vascular remodeling) which are absolute prerequisite to preserve the sensitive relationship between resilience and stability of the vessel wall. Further, a particular advantage for the therapeutic application of VW-MPSCs for improving vascular function or preventing vascular damage will be discussed.

  16. Cytotoxicity of cadmium-containing quantum dots based on a study using a microfluidic chip

    International Nuclear Information System (INIS)

    Zheng Xiannuo; Weng Lixing; Tian Jing; Wang Lianhui; Wu Lei; Jin Qinghui; Zhao Jianlong

    2012-01-01

    There is a lack of reliable nanotoxicity assays available for monitoring and quantifying multiple cellular events in cultured cells. In this study, we used a microfluidic chip to systematically investigate the cytotoxicity of three kinds of well-characterized cadmium-containing quantum dots (QDs) with the same core but different shell structures, including CdTe core QDs, CdTe/CdS core–shell QDs, and CdTe/CdS/ZnS core–shell–shell QDs, in HEK293 cells. Using the microfluidic chip combined with fluorescence microscopy, multiple QD-induced cellular events including cell morphology, viability, proliferation, and QD uptake were simultaneously analysed. The three kinds of QDs showed significantly different cytotoxicities. The CdTe QDs, which are highly toxic to HEK293 cells, resulted in remarkable cellular and nuclear morphological changes, a dose-dependent decrease in cell viability, and strong inhibition of cell proliferation; the CdTe/CdS QDs were moderately toxic but did not significantly affect the proliferation of HEK293 cells; while the CdTe/CdS/ZnS QDs had no detectable influence on cytotoxicity with respect to cell morphology, viability, and proliferation. Our data indicated that QD cytotoxicity was closely related to their surface structures and specific physicochemical properties. This study also demonstrated that the microfluidic chip could serve as a powerful tool to systematically evaluate the cytotoxicity of nanoparticles in multiple cellular events. (paper)

  17. Cytotoxicity of cadmium-containing quantum dots based on a study using a microfluidic chip

    Science.gov (United States)

    Zheng, Xiannuo; Tian, Jing; Weng, Lixing; Wu, Lei; Jin, Qinghui; Zhao, Jianlong; Wang, Lianhui

    2012-02-01

    There is a lack of reliable nanotoxicity assays available for monitoring and quantifying multiple cellular events in cultured cells. In this study, we used a microfluidic chip to systematically investigate the cytotoxicity of three kinds of well-characterized cadmium-containing quantum dots (QDs) with the same core but different shell structures, including CdTe core QDs, CdTe/CdS core-shell QDs, and CdTe/CdS/ZnS core-shell-shell QDs, in HEK293 cells. Using the microfluidic chip combined with fluorescence microscopy, multiple QD-induced cellular events including cell morphology, viability, proliferation, and QD uptake were simultaneously analysed. The three kinds of QDs showed significantly different cytotoxicities. The CdTe QDs, which are highly toxic to HEK293 cells, resulted in remarkable cellular and nuclear morphological changes, a dose-dependent decrease in cell viability, and strong inhibition of cell proliferation; the CdTe/CdS QDs were moderately toxic but did not significantly affect the proliferation of HEK293 cells; while the CdTe/CdS/ZnS QDs had no detectable influence on cytotoxicity with respect to cell morphology, viability, and proliferation. Our data indicated that QD cytotoxicity was closely related to their surface structures and specific physicochemical properties. This study also demonstrated that the microfluidic chip could serve as a powerful tool to systematically evaluate the cytotoxicity of nanoparticles in multiple cellular events.

  18. On Elementary and Algebraic Cellular Automata

    Science.gov (United States)

    Gulak, Yuriy

    In this paper we study elementary cellular automata from an algebraic viewpoint. The goal is to relate the emergent complex behavior observed in such systems with the properties of corresponding algebraic structures. We introduce algebraic cellular automata as a natural generalization of elementary ones and discuss their applications as generic models of complex systems.

  19. A perillyl alcohol-conjugated analog of 3-bromopyruvate without cellular uptake dependency on monocarboxylate transporter 1 and with activity in 3-BP-resistant tumor cells.

    Science.gov (United States)

    Chen, Thomas C; Yu, Jiali; Nouri Nigjeh, Eslam; Wang, Weijun; Myint, Phyo Thazin; Zandi, Ebrahim; Hofman, Florence M; Schönthal, Axel H

    2017-08-01

    The anticancer agent 3-bromopyruvate (3-BP) is viewed as a glycolytic inhibitor that preferentially kills glycolytic cancer cells through energy depletion. However, its cytotoxic activity is dependent on cellular drug import through transmembrane monocarboxylate transporter 1 (MCT-1), which restricts its anticancer potential to MCT-1-positive tumor cells. We created and characterized an MCT-1-independent analog of 3-BP, called NEO218. NEO218 was synthesized by covalently conjugating 3-BP to perillyl alcohol (POH), a natural monoterpene. The responses of various tumor cell lines to treatment with either compound were characterized in the presence or absence of supplemental pyruvate or antioxidants N-acetyl-cysteine (NAC) and glutathione (GSH). Drug effects on glyceraldehyde 3-phosphate dehydrogenase (GAPDH) enzyme activity were investigated by mass spectrometric analysis. The development of 3-BP resistance was investigated in MCT-1-positive HCT116 colon carcinoma cells in vitro. Our results show that NEO218: (i) pyruvylated GAPDH on all 4 of its cysteine residues and shut down enzymatic activity; (ii) severely lowered cellular ATP content below life-sustaining levels, and (iii) triggered rapid necrosis. Intriguingly, supplemental antioxidants effectively prevented cytotoxic activity of NEO218 as well as 3-BP, but supplemental pyruvate powerfully protected cells only from 3-BP, not from NEO218. Unlike 3-BP, NEO218 exerted its potent cytotoxic activity irrespective of cellular MCT-1 status. Treatment of HCT116 cells with 3-BP resulted in prompt development of resistance, based on the emergence of MCT-1-negative cells. This was not the case with NEO218, and highly 3-BP-resistant cells remained exquisitely sensitive to NEO218. Thus, our study identifies a mechanism by which tumor cells develop rapid resistance to 3-BP, and presents NEO218 as a superior agent not subject to this cellular defense. Furthermore, our results offer alternative interpretations of previously

  20. In vitro cytotoxicity of biosynthesized titanium dioxide nanoparticles ...

    African Journals Online (AJOL)

    The FT-IR spectrum of C. tamala leaf extract showed that the biomolecules were potentially involved in reduction processes. The negative zeta potential of -14 mV indicated that the NPs were stable and discrete while their crystalline nature was confirmed by XRD. Cytotoxicity analysis showed that the TiO2 NPs exhibit a ...

  1. Cytotoxic and toxicogenomic effects of silibinin in bladder cancer

    Indian Academy of Sciences (India)

    Silibinin is a natural phenol found in the seeds of the milk thistle plant. Recent data have shown its effectiveness forpreventing/treating bladder tumours. Therefore, in this study we investigated the cytotoxic and toxicogenetic activityof silibinin in bladder cancer cells with different TP53 statuses. Two bladder urothelial ...

  2. Cytotoxicity against MCF-7 breast cancer cell line and interaction ...

    African Journals Online (AJOL)

    N6-furfuryladenine (kinetin) is a cytokinin growth factor with several biological effects observed in human cells and fruit flies. Kinetin exists naturally in the DNA of almost all organisms tested so far, including human cells and various plants. The cytotoxicity effect of kinetin on MCF-7 breast cancer cell lines was measured by ...

  3. Fc gamma receptor activation induces the tyrosine phosphorylation of both phospholipase C (PLC)-gamma 1 and PLC-gamma 2 in natural killer cells

    OpenAIRE

    1992-01-01

    Crosslinking of the low affinity immunoglobulin G (IgG) Fc receptor (Fc gamma R type III) on natural killer (NK) cells initiates antibody- dependent cellular cytotoxicity. During this process, Fc gamma R stimulation results in the rapid activation of phospholipase C (PLC), which hydrolyzes membrane phosphoinositides, generating inositol-1,4,5- trisphosphate and sn-1,2-diacylglycerol as second messengers. We have recently reported that PLC activation after Fc gamma R stimulation can be inhibit...

  4. Genipin-induced inhibition of uncoupling protein-2 sensitizes drug-resistant cancer cells to cytotoxic agents.

    Directory of Open Access Journals (Sweden)

    Ryan J Mailloux

    2010-10-01

    Full Text Available Uncoupling protein-2 (UCP2 is known to suppress mitochondrial reactive oxygen species (ROS production and is employed by drug-resistant cancer cells to mitigate oxidative stress. Using the drug-sensitive HL-60 cells and the drug-resistant MX2 subline as model systems, we show that genipin, a UCP2 inhibitor, sensitizes drug-resistant cells to cytotoxic agents. Increased MX2 cell death was observed upon co-treatment with genipin and different doses of menadione, doxorubicin, and epirubicin. DCFH-DA fluorimetry revealed that the increase in MX2 cell death was accompanied by enhanced cellular ROS levels. The drug-induced increase in ROS was linked to genipin-mediated inhibition of mitochondrial proton leak. State 4 and resting cellular respiratory rates were higher in the MX2 cells in comparison to the HL-60 cells, and the increased respiration was readily suppressed by genipin in the MX2 cells. UCP2 accounted for a remarkable 37% of the resting cellular oxygen consumption indicating that the MX2 cells are functionally reliant on this protein. Higher amounts of UCP2 protein were detected in the MX2 versus the HL-60 mitochondria. The observed effects of genipin were absent in the HL-60 cells pointing to the selectivity of this natural product for drug-resistant cells. The specificity of genipin for UCP2 was confirmed using CHO cells stably expressing UCP2 in which genipin induced an ∼22% decrease in state 4 respiration. These effects were absent in empty vector CHO cells expressing no UCP2. Thus, the chemical inhibition of UCP2 with genipin sensitizes multidrug-resistant cancer cells to cytotoxic agents.

  5. Klebsiella pneumoniae triggers a cytotoxic effect on airway epithelial cells

    Directory of Open Access Journals (Sweden)

    Llobet-Brossa Enrique

    2009-08-01

    Full Text Available Abstract Background Klebsiella pneumoniae is a capsulated Gram negative bacterial pathogen and a frequent cause of nosocomial infections. Despite its clinical relevance, little is known about the features of the interaction between K. pneumoniae and lung epithelial cells on a cellular level, neither about the role of capsule polysaccharide, one of its best characterised virulence factors, in this interaction. Results The interaction between Klebsiella pneumoniae and cultured airway epithelial cells was analysed. K. pneumoniae infection triggered cytotoxicity, evident by cell rounding and detachment from the substrate. This effect required the presence of live bacteria and of capsule polysaccharide, since it was observed with isolates expressing different amounts of capsule and/or different serotypes but not with non-capsulated bacteria. Cytotoxicity was analysed by lactate dehydrogenase and formazan measurements, ethidium bromide uptake and analysis of DNA integrity, obtaining consistent and complementary results. Moreover, cytotoxicity of non-capsulated strains was restored by addition of purified capsule during infection. While a non-capsulated strain was avirulent in a mouse infection model, capsulated K. pneumoniae isolates displayed different degrees of virulence. Conclusion Our observations allocate a novel role to K. pneumoniae capsule in promotion of cytotoxicity. Although this effect is likely to be associated with virulence, strains expressing different capsule levels were not equally virulent. This fact suggests the existence of other bacterial requirements for virulence, together with capsule polysaccharide.

  6. Cellular strategies to cope with protein aggregation

    NARCIS (Netherlands)

    Scior, Annika; Juenemann, Katrin; Kirstein, Janine

    2016-01-01

    Nature has evolved several mechanisms to detoxify intracellular protein aggregates that arise upon proteotoxic challenges. These include the controlled deposition of misfolded proteins at distinct cellular sites, the protein disaggregation and refolding by molecular chaperones and/or degradation of

  7. Cytotoxic and cytoprotective activities of curcumin. Effects on paracetamol-induced cytotoxicity, lipid peroxidation and glutathione depletion in rat hepatocytes

    NARCIS (Netherlands)

    Donatus, I A; Sardjoko,; Vermeulen, N P

    1990-01-01

    The cytoprotective effect of curcumin, a natural constituent of Curcuma longa, on the cytotoxicity of paracetamol in rat hepatocytes was studied. Paracetamol was selected as a model-toxin, since it is known to be bioactivated by 3-methylcholanthrene inducible cytochromes P450 presumably to

  8. Cellular glutathione prevents cytolethality of monomethylarsonic acid

    International Nuclear Information System (INIS)

    Sakurai, Teruaki; Kojima, Chikara; Ochiai, Masayuki; Ohta, Takami; Sakurai, Masumi H.; Waalkes, Michael P.; Fujiwara, Kitao

    2004-01-01

    Inorganic arsenicals are clearly toxicants and carcinogens in humans. In mammals, including humans, inorganic arsenic often undergoes methylation, forming compounds such as monomethylarsonic acid (MMAs V ) and dimethylarsinic acid (DMAs V ). However, much less information is available on the in vitro toxic potential or mechanisms of these methylated arsenicals, especially MMAs V . We studied the molecular mechanisms of in vitro cytolethality of MMAs V using a rat liver epithelial cell line (TRL 1215). MMAs V was not cytotoxic in TRL 1215 cells even at concentrations exceeding 10 mM, but it became weakly cytotoxic and induced both necrotic and apoptotic cell death when cellular reduced glutathione (GSH) was depleted with the glutathione synthase inhibitor, L-buthionine-[S,R]-sulfoximine (BSO), or the glutathione reductase inhibitor, carmustine. Similar results were observed in the other mammalian cells, such as human skin TIG-112 cells, chimpanzee skin CRT-1609 cells, and mouse metallothionein (MT) positive and MT negative embryonic cells. Ethacrynic acid (EA), an inhibitor of glutathione S-transferase (GST) that catalyses GSH-substrate conjugation, also enhanced the cytolethality of MMAs V , but aminooxyacetic acid (AOAA), an inhibitor of β-lyase that catalyses the final breakdown of GSH-substrate conjugates, had no effect. Both the cellular GSH levels and the cellular GST activity were increased by the exposure to MMAs V in TRL 1215 cells. On the other hand, the addition of exogenous extracellular GSH enhanced the cytolethality of MMAs V , although cellular GSH levels actually prevented the cytolethality of combined MMAs V and exogenous GSH. These findings indicate that human arsenic metabolite MMAs V is not a highly toxic compound in mammalian cells, and the level of cellular GSH is critical to its eventual toxic effects

  9. Cytotoxic drug sensitivity testing of tumor cells from patients with ovarian carcinoma using the fluorometric microculture cytotoxicity assay (FMCA).

    Science.gov (United States)

    Csoka, K; Larsson, R; Tholander, B; Gerdin, E; de la Torre, M; Nygren, P

    1994-08-01

    The automated fluorometric microculture cytotoxicity assay (FMCA) is based on the measurement of fluorescence generated from cellular hydrolysis of fluorescein diacetate (FDA) to fluorescein by viable cells after a 72-hr culture period in microtiter plates. The FMCA was adopted for chemosensitivity testing of tumor cells from patients with ovarian carcinoma. Thirty-seven samples of solid tumors and malignant effusions were obtained from 35 patients at diagnosis or relapse. Tumor cells from solid samples and effusions were prepared by enzymatic digestion and centrifugation, respectively, followed by Percoll or Ficoll purification. The fluorescence was proportional to the number of cells/well and considerably higher in tumor cells than in contaminating normal cells. The effect of up to 19 cytotoxic drugs was successfully assessed in 70% of the samples and there was a good correlation between drug sensitivity data reported by the FMCA and the DiSC assay performed in parallel. The overall drug sensitivity pattern in vitro corresponded well to the clinical experience. The effect of cisplatin varied considerably between patients and resistance was found also in cases not previously exposed to cytotoxic drugs. The FMCA is a rapid and simple method that seems to report clinically relevant cytotoxic drug sensitivity data in ovarian carcinomas. In the future, this method may contribute to optimizing chemotherapy by assisting in individualized drug selection and new drug development.

  10. Antioxidant and cytotoxicity effects of seed oils from edible fruits

    OpenAIRE

    Olubunmi Atolani; Joshua Omere; C.A. Otuechere; A. Adewuyi

    2012-01-01

    Objective: To propose a natural remedy for the some acute diseases the fatty acids profile, antioxidant and cytotoxicity potentials of seed oils from natural sources have been examined. Methods: The fatty acids profile of seed oils from sweet orange, grape, lime and watermelon obtained by soxhlet extraction were trans-esterified and examined by gas chromatography-mass spectrometry (GC-MS). The antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl assay were examined and compared with ga...

  11. Cytotoxic and radioprotective effects of Podophyllum hexandrum.

    Science.gov (United States)

    Shukla, Sandeep Kumar; Chaudhary, Pankaj; Prem Kumar, Indracanti; Afrin, Farhat; Puri, Satish Chandra; Qazi, Ghulam Nabi; Sharma, Rakesh Kumar

    2006-07-01

    Podophyllum hexandrum, a herb thriving in Himalayas has already been reported to exhibit antitumor and radioprotective properties. Present study was undertaken to unravel the possible mechanism responsible for the cytotoxic and radioprotective properties of REC-2001, a fraction isolated from the rhizome of P. hexandrum using murine peritoneal macrophages and plasmid DNA as model systems. Cell death, levels of intracellular reactive oxygen species (ROS) and apoptosis were studied employing trypan blue exclusion assay, dichlorofluorescein diacetate and DNA fragmentation assay, respectively. Superoxide anions, hydroxyl radicals and DNA damage were estimated following nitroblue tetrazolium, 2-deoxyribose degradation and plasmid DNA relaxation assays, respectively. Pre-irradiation administration of REC-2001 to peritoneal macrophages in the concentration range of 25-200μg/ml significantly reduced radiation induced ROS generation, DNA damage, apoptosis and cell killing in comparison to radiation control group indicating radioprotective potential. Studies with plasmid DNA indicated the ability of REC-2001 to inhibit 20Gy induced single and double strand breaks further supporting the antioxidative potential. However, REC-2001 in a dose-dependent fashion induced cell death, ROS and DNA fragmentation indicating the cytotoxic nature. REC-2001, in presence of 100μM copper sulfate, generated significant amount of hydroxyl radicals and superoxide anions indicating ability to act as a pro-oxidant in presence of metal ions. The superoxide anion generation was found to be sensitive to metal chelators like EDTA and deferoxamine mesylate (DFR). These results suggest that the ability of REC-2001 to act as a pro-oxidant in presence of metal ions and antioxidant in presence of free radicals might be responsible for cytotoxic and radioprotective properties.

  12. Cytotoxicity of an 125I-labelled DNA ligand

    International Nuclear Information System (INIS)

    Karagiannis, T.C.; Lobachevsky, P.N.; Martin, R.F.

    2000-01-01

    The subcellular distribution and cytotoxicity of a DNA-binding ligand [ 125 I]-Hoechst 33258 following incubation of K562 cells with the drug was investigated. The ability of a radical scavenger, dimethyl sulphoxide, to protect cells from the 125 I-decay induced cell death was also studied. Three different concentrations and specific activities of the drug were used to provide different ligand : DNA binding ratios. The results demonstrated a trend toward improved delivery of the ligand to the nucleus and to chromatin at higher ligand concentrations, with concomitant increased sensitivity to 125 I-decay induced cytotoxicity and decreased protection by dimethyl sulphoxide. This correlation of radiobiological parameters with subcellular drug distribution is consistent with the classical dogma that attributes cytotoxicity to DNA double-stranded breakage in the vicinity of the site of decay, where the high LET nature of the damage confers minimal sensitivity to radical scavenging

  13. Ceramide binding to anandamide increases its half-life and potentiates its cytotoxicity in human neuroblastoma cells.

    Science.gov (United States)

    Di Scala, Coralie; Mazzarino, Morgane; Yahi, Nouara; Varini, Karine; Garmy, Nicolas; Fantini, Jacques; Chahinian, Henri

    2017-06-01

    Anandamide (AEA) is a ubiquitous lipid that exerts neurotransmitter functions but also controls important biological functions such as proliferation, survival, or programmed cell death. The latter effects are also regulated by ceramide, a lipid enzymatically generated from sphingomyelin hydrolysis by sphingomyelinase. Ceramide has been shown to increase the cellular toxicity of AEA, but the mechanisms controlling this potentiating effect remained unclear. Here we have used a panel of in silico, physicochemical, biochemical and cellular approaches to study the crosstalk between AEA and ceramide apoptotic pathways. Molecular dynamics simulations indicated that AEA and ceramide could form a stable complex in phosphatidylcholine membranes. Consistent with these data, we showed that AEA can specifically insert into ceramide monolayers whereas it did not penetrate into sphingomyelin membranes. Then we have studied the effects of ceramide on AEA-induced toxicity of human neuroblastoma cells. In these experiments, the cells have been either naturally enriched in ceramide by neutral sphingomyelinase pre-incubation or treated with C2-ceramide, a biologically active ceramide analog. Both treatments significantly increased the cytotoxicity of AEA as assessed by the MTS mitochondrial toxicity assay. This effect was correlated with the concomitant accumulation of natural ceramide (or its synthetic analog) and AEA in the cells. A kinetic study of AEA hydrolysis showed that ceramide inhibited the fatty acid amino hydrolase (FAAH) activity in cell extracts. Taken together, these data suggested that ceramide binds to AEA, increases its half-life and potentiates its cytotoxicity. Overall, these mechanisms account for a functional cross-talk between AEA and ceramide apoptotic pathways. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. In vitro preliminary cytotoxicity testing of vegetal extracts, using colorimetric methods

    Directory of Open Access Journals (Sweden)

    Claudia Patricia Cordero Camacho

    2002-01-01

    Full Text Available To advance in the study of the Colombian vegetal biodiversity, considered as a potential source of pharmacologically active products, the establishment of biological activity evaluation systems is necessary, which allow the detection of active products against pathologies with high social and economical impact, such as cancer. This work describes the implementation of a preliminary in vitro methodology for the determination of potential anticancer activity in vegetal extracts, by cytotoxicity testing upon human tumor cell lines, measuring the cellular mass indirectly with the colorimetric assays of MTT (methyl tetrazolium tiazole reduction and SRB (sulforhodamine Bstaining. HT-29, MCF-7, SiHa and HEp-2 cell lines cultures were adapted, MTT concentration, cellular density and treatment period parameters for the cytotoxicity assay were selected. Cell lines sensitivity to the chemotherapeutic agent Doxorubicin HCl was determined. Colombian vegetal species extracts cytotoxicity was tested and usefulness of the assay as a tool to bioguide the search of active products was evidenced.

  15. In vitro preliminary cytotoxicity testing of vegetal extracts, using colorimetric methods

    Directory of Open Access Journals (Sweden)

    Claudia Patricia Cordero Camacho

    2011-12-01

    Full Text Available To advance in the study of the Colombian vegetal biodiversity, considered as a potential source of pharmacologically active products, the establishment of biological activity evaluation systems is necessary, which allow the detection of active products against pathologies with high social and economical impact, such as cancer. This work describes the implementation of a preliminary in vitro methodology for the determination of potential anticancer activity in vegetal extracts, by cytotoxicity testing upon human tumor cell lines, measuring the cellular mass indirectly with the colorimetric assays of MTT (methyl tetrazolium tiazole reduction and SRB (sulforhodamine Bstaining. HT-29, MCF-7, SiHa and HEp-2 cell lines cultures were adapted, MTT concentration, cellular density and treatment period parameters for the cytotoxicity assay were selected. Cell lines sensitivity to the chemotherapeutic agent Doxorubicin HCl was determined. Colombian vegetal species extracts cytotoxicity was tested and usefulness of the assay as a tool to bioguide the search of active products was evidenced.

  16. Recombinant IgG1 Fc hexamers block cytotoxicity and pathological changes in experimental in vitro and rat models of neuromyelitis optica.

    Science.gov (United States)

    Tradtrantip, Lukmanee; Felix, Christian M; Spirig, Rolf; Morelli, Adriana Baz; Verkman, A S

    2018-05-01

    Intravenous human immunoglobulin G (IVIG) may have therapeutic benefit in neuromyelitis optica spectrum disorders (herein called NMO), in part because of the anti-inflammatory properties of the IgG Fc region. Here, we evaluated recombinant Fc hexamers consisting of the IgM μ-tailpiece fused with the Fc region of human IgG1. In vitro, the Fc hexamers prevented cytotoxicity in aquaporin-4 (AQP4) expressing cells and in rat spinal cord slice cultures exposed to NMO anti-AQP4 autoantibody (AQP4-IgG) and complement, with >500-fold greater potency than IVIG or monomeric Fc fragments. Fc hexamers at low concentration also prevented antibody-dependent cellular cytotoxicity produced by AQP4-IgG and natural killer cells. Serum from rats administered a single intravenous dose of Fc hexamers at 50 mg/kg taken at 8 h did not produce complement-dependent cytotoxicity when added to AQP4-IgG-treated AQP4-expressing cell cultures. In an experimental rat model of NMO produced by intracerebral injection of AQP4-IgG, Fc hexamers at 50 mg/kg administered before and at 12 h after AQP4-IgG fully prevented astrocyte injury, complement activation, inflammation and demyelination. These results support the potential therapeutic utility of recombinant IgG1 Fc hexamers in AQP4-IgG seropositive NMO. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. ROLE OF MEMBRANE LIPID-COMPOSITION IN THE CYTOTOXICITY OF THE SESQUITERPENE LACTONE EUPATORIOPICRIN

    NARCIS (Netherlands)

    VANDERLINDE, JCC; WOERDENBAG, HJ; MALINGRE, TM; KAMPINGA, HH; KONINGS, AWT

    1993-01-01

    The aim of the present study was to investigate a possible role of lipid peroxidation in the cytotoxicity of eupatoriopicrin, the principal sesquiterpene lactone from Eupatorum cannabinum L. Incorporation of arachidonic acid acyl chains in the phospholipids of cellular membranes of mouse fibroblast

  18. Pattern of CD4 T‑lymphocyte Values in Cancer Patients on Cytotoxic ...

    African Journals Online (AJOL)

    Background: Assessment of patients prior to cytotoxic chemotherapy usually includes absolute neutrophils count. Other cellular markers of susceptibility to infection as well as immunocompetence include the T Helper lymphocyte count. In cancer patients, decrease in these lymphocytes has been observed to be associated ...

  19. Cytotoxic glucosphingolipid from Celtis Africana.

    Science.gov (United States)

    Perveen, Shagufta; Al-Taweel, Areej Mohammad; Fawzy, Ghada Ahmed; El-Shafae, Azza Muhammed; Khan, Afsar; Proksch, Peter

    2015-05-01

    Literature survey proved the use of the powdered sun-dried bark and roots of Celtis africana for the treatment of cancer in South Africa. The aim of this study was to do further isolation work on the ethyl acetate fraction and to investigate the cytotoxic activities of the various fractions and isolated compound. Cytotoxicity of petroleum ether, chloroform, ethyl acetate, n-butanol fractions and compound 1 were tested on mouse lymphoma cell line L5178Y using the microculture tetrazolium assay. One new glucosphingolipid 1 was isolated from the aerial parts of C. africana. The structure of the new compound was determined by extensive analysis by one-dimensional and two-dimensional nuclear magnetic resonance spectroscopy and mass spectrometry. The ethyl acetate fraction and compound 1 showed strong cytotoxic activity with an EC50 value of 8.3 μg/mL and 7.8 μg/mL, respectively, compared with Kahalalide F positive control (6.3 μg/mL). This is the first report of the occurrence of a cytotoxic glucosphingolipid in family Ulmaceae.

  20. Cellular dynamics in the draining lymph nodes during sensitization and elicitation phases of contact hypersensitivity

    DEFF Research Database (Denmark)

    Larsen, Jeppe Madura; Geisler, Carsten; Nielsen, Martin Weiss

    2007-01-01

    BACKGROUND: The different role of various immunological effector cells in contact hypersensitivity (CHS) is receiving increased attention. During the past decade, the involvement of different cell types in CHS has been investigated by the use of antibody-induced depletion of specific subtypes...... of immunological cells and by studying knockout mice lacking one or more of these immunological cell populations. OBJECTIVES: To develop a method for studying the collective cellular dynamics of immune cells in the draining lymph nodes during CHS in intact animals. PATIENTS/METHODS: Mice were sensitized and....../or challenged with 2,4-dinitrofluorobenzene or oxazolone. Using multi-parameter flow cytometry we determined the proliferation, activation state, and absolute number of helper T cells, cytotoxic T cells, B cells, and natural killer cells in the draining lymph nodes. RESULTS: The presented method can be applied...

  1. The antioxidant properties, cytotoxicity and monoamine oxidase ...

    African Journals Online (AJOL)

    ajl yemi

    2011-11-28

    Nov 28, 2011 ... and the nitroblue tetrazolium (NBT) assay. The cytotoxicity ... The antioxidant activity and cytotoxic effect of the extracts increased with increase ... supplements are concoctions of plants and/or plant .... In vitro antioxidant assay.

  2. Actin retrograde flow controls natural killer cell response by regulating the conformation state of SHP-1.

    Science.gov (United States)

    Matalon, Omri; Ben-Shmuel, Aviad; Kivelevitz, Jessica; Sabag, Batel; Fried, Sophia; Joseph, Noah; Noy, Elad; Biber, Guy; Barda-Saad, Mira

    2018-03-01

    Natural killer (NK) cells are a powerful weapon against viral infections and tumor growth. Although the actin-myosin (actomyosin) cytoskeleton is crucial for a variety of cellular processes, the role of mechanotransduction, the conversion of actomyosin mechanical forces into signaling cascades, was never explored in NK cells. Here, we demonstrate that actomyosin retrograde flow (ARF) controls the immune response of primary human NK cells through a novel interaction between β-actin and the SH2-domain-containing protein tyrosine phosphatase-1 (SHP-1), converting its conformation state, and thereby regulating NK cell cytotoxicity. Our results identify ARF as a master regulator of the NK cell immune response. Since actin dynamics occur in multiple cellular processes, this mechanism might also regulate the activity of SHP-1 in additional cellular systems. © 2018 The Authors.

  3. Norartocarpetin from a folk medicine Artocarpus communis plays a melanogenesis inhibitor without cytotoxicity in B16F10 cell and skin irritation in mice.

    Science.gov (United States)

    Ko, Horng-Huey; Tsai, Yi-Ting; Yen, Ming-Hong; Lin, Chun-Ching; Liang, Chan-Jung; Yang, Tsung-Han; Lee, Chiang-Wen; Yen, Feng-Lin

    2013-12-10

    Many natural products used in preventive medicine have also been developed as cosmeceutical ingredients in skin care products, such as Scutellaria baicalensis and Gardenia jasminoides. Norartocarpetin is one of the antioxidant and antityrosinase activity compound in Artocarpus communis; however, the cytotoxicity, skin irritation and antimelanogenesis mechanisms of norartocarpetin have not been investigated yet. In the present study, cell viability in vitro and skin irritation in vivo are used to determine the safety of norartocarpetin. The melanogenesis inhibition of norartocarpetin was determined by cellular melanin content and tyrosinase in B16F10 melanoma cell. Moreover, we examined the related-melanogenesis protein by western blot analysis for elucidating the antimelanogenesis mechanism of norartocarpin. The result of the present study demonstrated that norartocarpetin not only present non-cytotoxic in B16F10 and human fibroblast cells but also non-skin irritation in mice. Moreover, our result also first found that norartocarpetin downregulated phospho-cAMP response element-binding (phospho-CREB) and microphthalmia-associated transcription factor (MITF) expression, which in turn decreased both synthesis of tyrosinases (TRP-1 and TRP-2) and cellular melanin content. This process is dependent on norartocarpetin phosphorylation by mitogen-activated protein kinases such as phospho-JNK and phospho-p38, and it results in decreased melanogenesis. The present study suggests that norartocarpetin could be used as a whitening agent in medicine and/or cosmetic industry and need further clinical study.

  4. Silver Nanoparticle-Mediated Cellular Responses in Various Cell Lines: An in Vitro Model

    Directory of Open Access Journals (Sweden)

    Xi-Feng Zhang

    2016-09-01

    Full Text Available Silver nanoparticles (AgNPs have attracted increased interest and are currently used in various industries including medicine, cosmetics, textiles, electronics, and pharmaceuticals, owing to their unique physical and chemical properties, particularly as antimicrobial and anticancer agents. Recently, several studies have reported both beneficial and toxic effects of AgNPs on various prokaryotic and eukaryotic systems. To develop nanoparticles for mediated therapy, several laboratories have used a variety of cell lines under in vitro conditions to evaluate the properties, mode of action, differential responses, and mechanisms of action of AgNPs. In vitro models are simple, cost-effective, rapid, and can be used to easily assess efficacy and performance. The cytotoxicity, genotoxicity, and biocompatibility of AgNPs depend on many factors such as size, shape, surface charge, surface coating, solubility, concentration, surface functionalization, distribution of particles, mode of entry, mode of action, growth media, exposure time, and cell type. Cellular responses to AgNPs are different in each cell type and depend on the physical and chemical nature of AgNPs. This review evaluates significant contributions to the literature on biological applications of AgNPs. It begins with an introduction to AgNPs, with particular attention to their overall impact on cellular effects. The main objective of this review is to elucidate the reasons for different cell types exhibiting differential responses to nanoparticles even when they possess similar size, shape, and other parameters. Firstly, we discuss the cellular effects of AgNPs on a variety of cell lines; Secondly, we discuss the mechanisms of action of AgNPs in various cellular systems, and try to elucidate how AgNPs interact with different mammalian cell lines and produce significant effects; Finally, we discuss the cellular activation of various signaling molecules in response to AgNPs, and conclude with

  5. Surface Dynamic Process Simulation with the Use of Cellular Automata

    International Nuclear Information System (INIS)

    Adamska-Szatko, M.; Bala, J.

    2010-01-01

    Cellular automata are known for many applications, especially for physical and biological simulations. Universal cellular automata can be used for modelling complex natural phenomena. The paper presents simulation of surface dynamic process. Simulation uses 2-dimensional cellular automata algorithm. Modelling and visualisation were created by in-house developed software with standard OpenGL graphic library. (authors)

  6. Wireless Cellular Mobile Communications

    OpenAIRE

    Zalud, V.

    2002-01-01

    In this article is briefly reviewed the history of wireless cellular mobile communications, examined the progress in current second generation (2G) cellular standards and discussed their migration to the third generation (3G). The European 2G cellular standard GSM and its evolution phases GPRS and EDGE are described somewhat in detail. The third generation standard UMTS taking up on GSM/GPRS core network and equipped with a new advanced access network on the basis of code division multiple ac...

  7. The fluorometric microculture cytotoxicity assay.

    Science.gov (United States)

    Lindhagen, Elin; Nygren, Peter; Larsson, Rolf

    2008-01-01

    The fluorometric microculture cytotoxicity assay (FMCA) is a nonclonogenic microplate-based cell viability assay used for measurement of the cytotoxic and/or cytostatic effect of different compounds in vitro. The assay is based on hydrolysis of the probe, fluorescein diacetate (FDA) by esterases in cells with intact plasma membranes. The assay is available as both a semiautomated 96-well plate setup and a 384-well plate version fully adaptable to robotics. Experimental plates are prepared with a small amount of drug solution and can be stored frozen. Cells are seeded on the plates and cell viability is evaluated after 72 h. The protocol described here is applicable both for cell lines and freshly prepared tumor cells from patients and is suitable both for screening in drug development and as a basis for a predictive test for individualization of anticancer drug therapy.

  8. Cytotoxic diterpenes from Scoparia dulcis.

    Science.gov (United States)

    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.

  9. Comparative cytotoxicity of periodontal bacteria

    International Nuclear Information System (INIS)

    Stevens, R.H.; Hammond, B.F.

    1988-01-01

    The direct cytotoxicity of sonic extracts (SE) from nine periodontal bacteria for human gingival fibroblasts (HGF) was compared. Equivalent dosages (in terms of protein concentration) of SE were used to challenge HGF cultures. The cytotoxic potential of each SE was assessed by its ability to (1) inhibit HGF proliferation, as measured by direct cell counts; (2) inhibit 3H-thymidine incorporation in HGF cultures; or (3) cause morphological alterations of the cells in challenged cultures. The highest concentration (500 micrograms SE protein/ml) of any of the SEs used to challenge the cells was found to be markedly inhibitory to the HGFs by all three of the criteria of cytotoxicity. At the lowest dosage tested (50 micrograms SE protein/ml); only SE from Actinobacillus actinomycetemcomitans, Bacteroides gingivalis, and Fusobacterium nucleatum caused a significant effect (greater than 90% inhibition or overt morphological abnormalities) in the HGFs as determined by any of the criteria employed. SE from Capnocytophaga sputigena, Eikenella corrodens, or Wolinella recta also inhibited cell proliferation and thymidine incorporation at this dosage; however, the degree of inhibition (5-50%) was consistently, clearly less than that of the first group of three organisms named above. The SE of the three other organisms tested (Actinomyces odontolyticus, Bacteroides intermedius, and Streptococcus sanguis) had little or no effect (0-10% inhibition) at this concentration. The data suggest that the outcome of the interaction between bacterial components and normal resident cells of the periodontium is, at least in part, a function of the bacterial species

  10. Cytotoxicity of graphene: recent advances and future perspective.

    Science.gov (United States)

    Zhou, Ruhong; Gao, Huajian

    2014-01-01

    Graphene, a unique two-dimensional single-atom-thin nanomaterial with exceptional structural, mechanical, and electronic properties, has spurred an enormous interest in many fields, including biomedical applications, which at the same time ignites a growing concern on its biosafety and potential cytotoxicity to human and animal cells. In this review, we present a summary of some very recent studies on this important subject with both experimental and theoretical approaches. The molecular interactions of graphene with proteins, DNAs, and cell membranes (both bacteria and mammalian cells) are discussed in detail. Severe distortions in structures and functions of these biomacromolecules by graphene are identified and characterized. For example, the graphene is shown to disrupt bacteria cell membranes by insertion/cutting as well as destructive extraction of lipid molecules directly. More interestingly, this cytotoxicity has been shown to have implications in de novo design of nanomedicine, such as graphene-based band-aid, a potential 'green' antibiotics due to its strong physical-based (instead of chemical-based) antibacterial capability. These studies have provided a better understanding of graphene nanotoxicity at both cellular and molecular levels, and also suggested therapeutic potential by using graphene's cytotoxicity against bacteria cells. © 2014 Wiley Periodicals, Inc.

  11. Modification of the cytotoxic activity of mitomycin C

    International Nuclear Information System (INIS)

    Marshall, R.S.; Rauth, A.M.

    1985-01-01

    Utilizing a system in which oxygen levels could be altered and monitored during acute drug exposures, the authors have begun to characterize the cellular and molecular damage produced by MMC in CHO cells. The cytotoxic activity of MMC decreases sharply from 0 to 0.1% oxygen in solution, while from 0.1 to 20.0% there is little change. DNA crosslinking in cells was examined under these conditions by alkaline elution and found to be directly correlated with cell killing. While hypoxia increased crosslinking, significant levels were still observed under aerobic conditions. A cell-free assay for alkylation confirmed that overall levels increase in the absence of oxygen; however, negligible alkylation was observed under aerobic conditions. It was also noted that ascorbic acid present in the exposure medium (0.284 mM) increased the aerobic cytotoxicity without altering the hypoxic cytotoxicity. The present data suggest that MMC can be activated to an alkylating species by two mechanisms, one oxygen sensitive and one oxygen insensitive and that these two mechanisms may be independently modified

  12. Study of Galfenol direct cytotoxicity and remote microactuation in cells.

    Science.gov (United States)

    Vargas-Estevez, Carolina; Blanquer, Andreu; Dulal, Prabesh; Pérez Del Real, Rafael; Duch, Marta; Ibáñez, Elena; Barrios, Leonardo; Murillo, Gonzalo; Torras, Núria; Nogués, Carme; Stadler, Bethanie J H; Plaza, José A; Esteve, Jaume

    2017-09-01

    Remote microactuators are of great interest in biology and medicine as minimally-invasive tools for cellular stimulation. Remote actuation can be achieved by active magnetostrictive transducers which are capable of changing shape in response to external magnetic fields thereby creating controlled displacements. Among the magnetostrictive materials, Galfenol, the multifaceted iron-based smart material, offers high magnetostriction with robust mechanical properties. In order to explore these capabilities for biomedical applications, it is necessary to study the feasibility of material miniaturization in standard fabrication processes as well as evaluate the biocompatibility. Here we develop a technology to fabricate, release, and suspend Galfenol-based microparticles, without affecting the integrity of the material. The morphology, composition and magnetic properties of the material itself are characterized. The direct cytotoxicity of Galfenol is evaluated in vitro using human macrophages, osteoblast and osteosarcoma cells. In addition, cytotoxicity and actuation of Galfenol microparticles in suspension are evaluated using human macrophages. The biological parameters analyzed indicate that Galfenol is not cytotoxic, even after internalization of some of the particles by macrophages. The microparticles were remotely actuated forming intra- and extracellular chains that did not impact the integrity of the cells. The results propose Galfenol as a suitable material to develop remote microactuators for cell biology studies and intracellular applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    C. M. Mattana

    2014-01-01

    Full Text Available 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.

  14. Anticancer Activity of Chloroform Extract and Sub-fractions of Nepeta deflersiana on Human Breast and Lung Cancer Cells: An In vitro Cytotoxicity Assessment.

    Science.gov (United States)

    Al-Oqail, Mai M; Al-Sheddi, Ebtesam S; Siddiqui, Maqsood A; Musarrat, Javed; Al-Khedhairy, Abdulaziz A; Farshori, Nida N

    2015-10-01

    Cancer is one of the major causes of death worldwide. The plant-derived natural products have received considerable attention in recent years due to their diverse pharmacological properties including anticancer effects. Nepeta deflersiana (ND) is used in the folk medicine as antiseptic, carminative, antimicrobial, antioxidant, and for treating rheumatic disorders. However, the anticancer activity of ND chloroform extract has not been explored so far. The present study was aimed to investigate the anticancer activities of chloroform Nepeta deflersiana extract and various sub-fractions (ND-1-ND-15) of ND against human breast cancer cells (MCF-7) and human lung cancer cells (A-549). The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide and neutral red uptake assays, and cellular morphological alterations using phase contrast light microscope were studied. Cells were exposed with 10-1000 μg/ml of sub-fractions of ND for 24 h. Results showed that selected sub-fractions of the chloroform extract significantly reduced the cell viability of MCF-7 and A-549 cells, and altered the cellular morphology in a concentration-dependent manner. Among the sub-fractions, ND-10 fraction showed relatively higher cytotoxicity compared to other fractions whereas, ND-1 did not cause any cytotoxicity even at higher concentrations. The A-549 cells were found to be more sensitive to growth inhibition by all the extracts as compared to the MCF-7 cells. The present study provides preliminary screening of anticancer activities of chloroform extract and sub-fractions of ND, which can be further used for the development of a potential therapeutic anticancer agent. Nepeta deflersiana extract exhibit cytotoxicity and altered the cellular morphology. Sub-fractions of the chloroform extract of Nepeta deflersiana reduced the cell viability of MCF-7 and A-549 cells. Among the sub-fractions, ND-10 fraction showed relatively higher cytotoxicity. The A-549 cells were found to be more sensitive

  15. Anticancer agent CHS-828 inhibits cellular synthesis of NAD

    DEFF Research Database (Denmark)

    Olesen, U.H.; Christensen, M.K.; Bjorkling, F.

    2008-01-01

    Malignant cells display increased demands for energy production and DNA repair. Nicotinamide adenine dinucleotide (NAD) is required for both processes and is also continuously degraded by cellular enzymes. Nicotinamide phosphoribosyltransferase (Nampt) is a crucial factor in the resynthesis of NAD......, and thus in cancer cell survival. Here, we establish the cytotoxic mechanism of action of the small molecule inhibitor CHS-828 to result from impaired synthesis of NAD. Initially, we detected cross-resistance in cells between CHS-828 and a known inhibitor of Nampt, FK866, a compound of a structurally...... different class. We then showed that nicotinamide protects against CHS-828-mediated cytotoxicity. Finally, we observed that treatment with CHS-828 depletes cellular NAD levels in sensitive cancer cells. In conclusion, these results strongly suggest that, like FK866, CHS-828 kills cancer cells by depleting...

  16. Linearizable cellular automata

    International Nuclear Information System (INIS)

    Nobe, Atsushi; Yura, Fumitaka

    2007-01-01

    The initial value problem for a class of reversible elementary cellular automata with periodic boundaries is reduced to an initial-boundary value problem for a class of linear systems on a finite commutative ring Z 2 . Moreover, a family of such linearizable cellular automata is given

  17. Real-time impedimetric monitoring of Poly(ethylenimine)s-mediated cytotoxicity during gene transfection

    DEFF Research Database (Denmark)

    Caviglia, Claudia; Carminati, Marco; Heiskanen, Arto

    Poly(ethylenimine)s (PEIs) are able to condense DNA and RNA into stable toroidal and globular nanostructures (polyplexes) and are among the most efficient and promising synthetic transfectants, but they induce severe cytotoxicity. The mechanisms of PEI-mediated cytotoxicity have not been fully...... delineated but PEI toxicity appears to predominantly depend on membrane perturbing effects in cellular compartments in which they accumulate. Electrochemical Impedance Spectroscopy (EIS) is used as a non-invasive biophysical approach for the investigation of the electrical properties of biological materials...

  18. Altered effector function of peripheral cytotoxic cells in COPD

    Directory of Open Access Journals (Sweden)

    Corne Jonathan M

    2009-06-01

    Full Text Available Abstract Background There is mounting evidence that perforin and granzymes are important mediators in the lung destruction seen in COPD. We investigated the characteristics of the three main perforin and granzyme containing peripheral cells, namely CD8+ T lymphocytes, natural killer (NK; CD56+CD3- cells and NKT-like (CD56+CD3+ cells. Methods Peripheral blood mononuclear cells (PBMCs were isolated and cell numbers and intracellular granzyme B and perforin were analysed by flow cytometry. Immunomagnetically selected CD8+ T lymphocytes, NK (CD56+CD3- and NKT-like (CD56+CD3+ cells were used in an LDH release assay to determine cytotoxicity and cytotoxic mechanisms were investigated by blocking perforin and granzyme B with relevant antibodies. Results The proportion of peripheral blood NKT-like (CD56+CD3+ cells in smokers with COPD (COPD subjects was significantly lower (0.6% than in healthy smokers (smokers (2.8%, p +CD3- cells from COPD subjects were significantly less cytotoxic than in smokers (16.8% vs 51.9% specific lysis, p +CD3+ cells (16.7% vs 52.4% specific lysis, p +CD3- and NKT-like (CD56+CD3+ cells from smokers and HNS. Conclusion In this study, we show that the relative numbers of peripheral blood NK (CD56+CD3- and NKT-like (CD56+CD3+ cells in COPD subjects are reduced and that their cytotoxic effector function is defective.

  19. Heterogeneous cellular networks

    CERN Document Server

    Hu, Rose Qingyang

    2013-01-01

    A timely publication providing coverage of radio resource management, mobility management and standardization in heterogeneous cellular networks The topic of heterogeneous cellular networks has gained momentum in industry and the research community, attracting the attention of standardization bodies such as 3GPP LTE and IEEE 802.16j, whose objectives are looking into increasing the capacity and coverage of the cellular networks. This book focuses on recent progresses,  covering the related topics including scenarios of heterogeneous network deployment, interference management i

  20. Cellular decomposition in vikalloys

    International Nuclear Information System (INIS)

    Belyatskaya, I.S.; Vintajkin, E.Z.; Georgieva, I.Ya.; Golikov, V.A.; Udovenko, V.A.

    1981-01-01

    Austenite decomposition in Fe-Co-V and Fe-Co-V-Ni alloys at 475-600 deg C is investigated. The cellular decomposition in ternary alloys results in the formation of bcc (ordered) and fcc structures, and in quaternary alloys - bcc (ordered) and 12R structures. The cellular 12R structure results from the emergence of stacking faults in the fcc lattice with irregular spacing in four layers. The cellular decomposition results in a high-dispersion structure and magnetic properties approaching the level of well-known vikalloys [ru

  1. Cellular Reflectarray Antenna

    Science.gov (United States)

    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.

  2. Treatment of a solid tumor using engineered drug-resistant immunocompetent cells and cytotoxic chemotherapy.

    Science.gov (United States)

    Dasgupta, Anindya; Shields, Jordan E; Spencer, H Trent

    2012-07-01

    Multimodal therapy approaches, such as combining chemotherapy agents with cellular immunotherapy, suffers from potential drug-mediated toxicity to immune effector cells. Overcoming such toxic effects of anticancer cellular products is a potential critical barrier to the development of combined therapeutic approaches. We are evaluating an anticancer strategy that focuses on overcoming such a barrier by genetically engineering drug-resistant variants of immunocompetent cells, thereby allowing for the coadministration of cellular therapy with cytotoxic chemotherapy, a method we refer to as drug-resistant immunotherapy (DRI). The strategy relies on the use of cDNA sequences that confer drug resistance and recombinant lentiviral vectors to transfer nucleic acid sequences into immunocompetent cells. In the present study, we evaluated a DRI-based strategy that incorporates the immunocompetent cell line NK-92, which has intrinsic antitumor properties, genetically engineered to be resistant to both temozolomide and trimetrexate. These immune effector cells efficiently lysed neuroblastoma cell lines, which we show are also sensitive to both chemotherapy agents. The antitumor efficacy of the DRI strategy was demonstrated in vivo, whereby neuroblastoma-bearing NOD/SCID/γ-chain knockout (NSG) mice treated with dual drug-resistant NK-92 cell therapy followed by dual cytotoxic chemotherapy showed tumor regression and significantly enhanced survival compared with animals receiving either nonengineered cell-based therapy and chemotherapy, immunotherapy alone, or chemotherapy alone. These data show there is a benefit to using drug-resistant cellular therapy when combined with cytotoxic chemotherapy approaches.

  3. In vitro assessment of cytotoxic activities of Lachesis muta muta snake venom.

    Directory of Open Access Journals (Sweden)

    Stephanie Stransky

    2018-04-01

    Full Text Available Envenomation by the bushmaster snake Lachesis muta muta is considered severe, characterized by local effects including necrosis, the main cause of permanent disability. However, cellular mechanisms related to cell death and tissue destruction, triggered by snake venoms, are poorly explored. The purpose of this study was to investigate the cytotoxic effect caused by L. m. muta venom in normal human keratinocytes and to identify the cellular processes involved in in cellulo envenomation. In order to investigate venom effect on different cell types, Alamar Blue assay was performed to quantify levels of cellular metabolism as a readout of cell viability. Apoptosis, necrosis and changes in mitochondrial membrane potential were evaluated by flow cytometry, while induction of autophagy was assessed by expression of GFP-LC3 and analyzed using fluorescence microscopy. The cytotoxic potential of the venom is shown by reduced cell viability in a concentration-dependent manner. It was also observed the sequential appearance of cells undergoing autophagy (by 6 hours, apoptosis and necrosis (12 and 24 hours. Morphologically, incubation with L. m. muta venom led to a significant cellular retraction and formation of cellular aggregates. These results indicate that L. m. muta venom is cytotoxic to normal human keratinocytes and other cell lines, and this toxicity involves the integration of distinct modes of cell death. Autophagy as a cell death mechanism, in addition to apoptosis and necrosis, can help to unravel cellular pathways and mechanisms triggered by the venom. Understanding the mechanisms that underlie cellular damage and tissue destruction will be useful in the development of alternative therapies against snakebites.

  4. In vitro antimycobacterial and cytotoxic data on medicinal plants used to treat tuberculosis

    Directory of Open Access Journals (Sweden)

    Joseph M. Nguta

    2016-06-01

    Full Text Available This article contains data on in vitro antimycobacterial activity and cytotoxicity of hydroethanolic crude extracts from five selected medicinal plant species traditionally used to treat tuberculosis in Ghanaian ethnomedicine, see “Medicinal plants used to treat TB in Ghana” [1]. The interpretation and discussion of these data and further extensive insights into drug discovery against tuberculosis from natural products of plant biodiversity can be found in “Antimycobacterial and cytotoxic activity of selected medicinal plant extracts” [2].

  5. Magnetohydrodynamics cellular automata

    International Nuclear Information System (INIS)

    Hatori, Tadatsugu.

    1990-02-01

    There has been a renewal of interest in cellular automata, partly because they give an architecture for a special purpose computer with parallel processing optimized to solve a particular problem. The lattice gas cellular automata are briefly surveyed, which are recently developed to solve partial differential equations such as hydrodynamics or magnetohydrodynamics. A new model is given in the present paper to implement the magnetic Lorentz force in a more deterministic and local procedure than the previous one. (author)

  6. Epigenetics and Cellular Metabolism

    OpenAIRE

    Wenyi Xu; Fengzhong Wang; Zhongsheng Yu; Fengjiao Xin

    2016-01-01

    Living eukaryotic systems evolve delicate cellular mechanisms for responding to various environmental signals. Among them, epigenetic machinery (DNA methylation, histone modifications, microRNAs, etc.) is the hub in transducing external stimuli into transcriptional response. Emerging evidence reveals the concept that epigenetic signatures are essential for the proper maintenance of cellular metabolism. On the other hand, the metabolite, a main environmental input, can also influence the proce...

  7. Modeling cellular systems

    CERN Document Server

    Matthäus, Franziska; Pahle, Jürgen

    2017-01-01

    This contributed volume comprises research articles and reviews on topics connected to the mathematical modeling of cellular systems. These contributions cover signaling pathways, stochastic effects, cell motility and mechanics, pattern formation processes, as well as multi-scale approaches. All authors attended the workshop on "Modeling Cellular Systems" which took place in Heidelberg in October 2014. The target audience primarily comprises researchers and experts in the field, but the book may also be beneficial for graduate students.

  8. Magnetohydrodynamic cellular automata

    Energy Technology Data Exchange (ETDEWEB)

    Hatori, Tadatsugu [National Inst. for Fusion Science, Nagoya (Japan)

    1990-03-01

    There has been a renewal of interest in cellular automata, partly because they give an architecture for a special purpose computer with parallel processing optimized to solve a particular problem. The lattice gas cellular automata are briefly surveyed, which are recently developed to solve partial differential equations such as hydrodynamics or magnetohydrodynamics. A new model is given in the present paper to implement the magnetic Lorentz force in a more deterministic and local procedure than the previous one. (author).

  9. Magnetohydrodynamic cellular automata

    International Nuclear Information System (INIS)

    Hatori, Tadatsugu

    1990-01-01

    There has been a renewal of interest in cellular automata, partly because they give an architecture for a special purpose computer with parallel processing optimized to solve a particular problem. The lattice gas cellular automata are briefly surveyed, which are recently developed to solve partial differential equations such as hydrodynamics or magnetohydrodynamics. A new model is given in the present paper to implement the magnetic Lorentz force in a more deterministic and local procedure than the previous one. (author)

  10. Cystatin F as a regulator of immune cell cytotoxicity.

    Science.gov (United States)

    Kos, Janko; Nanut, Milica Perišić; Prunk, Mateja; Sabotič, Jerica; Dautović, Esmeralda; Jewett, Anahid

    2018-05-10

    Cysteine cathepsins are lysosomal peptidases involved in the regulation of innate and adaptive immune responses. Among the diverse processes, regulation of granule-dependent cytotoxicity of cytotoxic T-lymphocytes (CTLs) and natural killer (NK) cells during cancer progression has recently gained significant attention. The function of cysteine cathepsins is regulated by endogenous cysteine protease inhibitors-cystatins. Whereas other cystatins are generally cytosolic or extracellular proteins, cystatin F is present in endosomes and lysosomes and is thus able to regulate the activity of its target directly. It is delivered to endosomal/lysosomal vesicles as an inactive, disulphide-linked dimer. Proteolytic cleavage of its N-terminal part leads to the monomer, the only form that is a potent inhibitor of cathepsins C, H and L, involved in the activation of granzymes and perforin. In NK cells and CTLs the levels of active cathepsin C and of granzyme B are dependent on the concentration of monomeric, active cystatin F. In tumour microenvironment, inactive dimeric cystatin F can be secreted from tumour cells or immune cells and further taken up by the cytotoxic cells. Subsequent monomerization and inhibition of cysteine cathepsins within the endosomal/lysosomal vesicles impairs granzyme and perforin activation, and provokes cell anergy. Further, the glycosylation pattern has been shown to be important in controlling secretion of cystatin F from target cells, as well as internalization by cytotoxic cells and trafficking to endosomal/lysosomal vesicles. Cystatin F is therefore an important mediator used by bystander cells to reduce NK and T-cell cytotoxicity.

  11. Cellular MR Imaging

    Directory of Open Access Journals (Sweden)

    Michel Modo

    2005-07-01

    Full Text Available Cellular MR imaging is a young field that aims to visualize targeted cells in living organisms. In order to provide a different signal intensity of the targeted cell, they are either labeled with MR contrast agents in vivo or prelabeled in vitro. Either (ultrasmall superparamagnetic iron oxide [(USPIO] particles or (polymeric paramagnetic chelates can be used for this purpose. For in vivo cellular labeling, Gd3+- and Mn2+- chelates have mainly been used for targeted hepatobiliary imaging, and (USPIO-based cellular imaging has been focused on imaging of macrophage activity. Several of these magneto-pharmaceuticals have been FDA-approved or are in late-phase clinical trials. As for prelabeling of cells in vitro, a challenge has been to induce a sufficient uptake of contrast agents into nonphagocytic cells, without affecting normal cellular function. It appears that this issue has now largely been resolved, leading to an active research on monitoring the cellular biodistribution in vivo following transplantation or transfusion of these cells, including cell migration and trafficking. New applications of cellular MR imaging will be directed, for instance, towards our understanding of hematopoietic (immune cell trafficking and of novel guided (stem cell-based therapies aimed to be translated to the clinic in the future.

  12. Genome-wide assessment of the carriers involved in the cellular uptake of drugs: a model system in yeast.

    Science.gov (United States)

    Lanthaler, Karin; Bilsland, Elizabeth; Dobson, Paul D; Moss, Harry J; Pir, Pınar; Kell, Douglas B; Oliver, Stephen G

    2011-10-24

    The uptake of drugs into cells has traditionally been considered to be predominantly via passive diffusion through the bilayer portion of the cell membrane. The recent recognition that drug uptake is mostly carrier-mediated raises the question of which drugs use which carriers. To answer this, we have constructed a chemical genomics platform built upon the yeast gene deletion collection, using competition experiments in batch fermenters and robotic automation of cytotoxicity screens, including protection by 'natural' substrates. Using these, we tested 26 different drugs and identified the carriers required for 18 of the drugs to gain entry into yeast cells. As well as providing a useful platform technology, these results further substantiate the notion that the cellular uptake of pharmaceutical drugs normally occurs via carrier-mediated transport and indicates that establishing the identity and tissue distribution of such carriers should be a major consideration in the design of safe and effective drugs.

  13. Antibody dependent cellular phagocytosis by macrophages is a novel mechanism of action of elotuzumab.

    Science.gov (United States)

    Kurdi, Ahmed T; Glavey, Siobhan V; Bezman, Natalie A; Jhatakia, Amy; Guerriero, Jennifer L; Manier, Salomon; Moschetta, Michele; Mishima, Yuji; Roccaro, Aldo; Detappe, Alexandre; Liu, Chia-Jen; Sacco, Antonio; Huynh, Daisy; Tai, Yu-Tzu; Robbins, Michael D; Azzi, Jamil; Ghobrial, Irene M

    2018-04-13

    Elotuzumab, a recently approved antibody for the treatment of multiple myeloma (MM), has been shown to stimulate Fcγ receptor (FcγR)-mediated antibody-dependent cellular cytotoxicity (ADCC) by natural killer (NK) cells towards myeloma cells. The modulatory effects of elotuzumab on other effector cells in the tumor microenvironment, however, has not been fully explored. Antibody dependent cellular phagocytosis (ADCP) is a mechanism by which macrophages contribute to anti-tumor potency of monoclonal antibodies. Herein, we studied the NK cell independent effect of elotuzumab on tumor associated macrophages (TAMs) using a xenograft tumor model deficient in NK and adaptive immune cells. We demonstrate significant anti-tumor efficacy of single agent elotuzumab in immunocompromised xenograft models of multiple myeloma, which is in part mediated by Fc-FcγR interaction of elotuzumab with macrophages. Elotuzumab is shown in this study to induce phenotypic activation of macrophages in-vivo and mediates ADCP of myeloma cells though a FcγR dependent manner in-vitro. Together, these findings propose a novel immune mediated mechanism by which elotuzumab exerts anti-myeloma activity and helps to provide rationale for combination therapies that can enhance macrophage activity. Copyright ©2018, American Association for Cancer Research.

  14. Microchip screening platform for single cell assessment of NK cell cytotoxicity

    Directory of Open Access Journals (Sweden)

    Karolin eGuldevall

    2016-04-01

    Full Text Available Here we report a screening platform for assessment of the cytotoxic potential of individual natural killer (NK cells within larger populations. Human primary NK cells were distributed across a silicon-glass microchip containing 32 400 individual microwells loaded with target cells. Through fluorescence screening and automated image analysis the numbers of NK and live or dead target cells in each well could be assessed at different time points after initial mixing. Cytotoxicity was also studied by time-lapse live-cell imaging in microwells quantifying the killing potential of individual NK cells. Although most resting NK cells (≈75% were non-cytotoxic against the leukemia cell line K562, some NK cells were able to kill several (≥3 target cells within the 12 hours long experiment. In addition, the screening approach was adapted to increase the chance to find and evaluate serial killing NK cells. Even if the cytotoxic potential varied between donors it was evident that a small fraction of highly cytotoxic NK cells were responsible for a substantial portion of the killing. We demonstrate multiple assays where our platform can be used to enumerate and characterize cytotoxic cells, such as NK or T cells. This approach could find use in clinical applications, e.g. in the selection of donors for stem cell transplantation or generation of highly specific and cytotoxic cells for adoptive immunotherapy.

  15. Evaluation of the Cytotoxicity of Structurally Correlated p-Menthane Derivatives

    Directory of Open Access Journals (Sweden)

    Luciana Nalone Andrade

    2015-07-01

    Full Text Available Compounds isolated from essential oils play an important role in the prevention and treatment of cancer. Monoterpenes are natural products, and the principal constituents of many essential oils. The aim of this study was to investigate the cytotoxic potential of p-menthane derivatives. Additionally, analogues of perillyl alcohol, a monoterpene with known anticancer activity, were evaluated to identify the molecular characteristics which contribute to their cytotoxicity, which was tested against OVCAR-8, HCT-116, and SF-295 human tumor cell lines, using the MTT assay. The results of this study showed that (−-perillaldehyde 8,9-epoxide exhibited the highest percentage inhibition of cell proliferation (GI = 96.32%–99.89%. Perillyl alcohol exhibited high cytotoxic activity (90.92%–95.82%, while (+-limonene 1,2-epoxide (GI = 58.48%–93.10%, (−-perillaldehyde (GI = 59.28%–83.03%, and (−-8-hydroxycarvotanacetone (GI = 61.59%–94.01% showed intermediate activity. All of the compounds tested were less cytotoxic than perillyl alcohol, except (−-perillaldehyde 8,9-epoxide (IC50 = 1.75–1.03 µL/mg. In general, replacement of C-C double bonds by epoxide groups in addition to the aldehyde group increases cytotoxicity. Furthermore, stereochemistry seems to play an important role in cytotoxicity. We have demonstrated the cytotoxic influence of chemical substituents on the p-menthane structure, and analogues of perillyl alcohol.

  16. Microchip Screening Platform for Single Cell Assessment of NK Cell Cytotoxicity

    Science.gov (United States)

    Guldevall, Karolin; Brandt, Ludwig; Forslund, Elin; Olofsson, Karl; Frisk, Thomas W.; Olofsson, Per E.; Gustafsson, Karin; Manneberg, Otto; Vanherberghen, Bruno; Brismar, Hjalmar; Kärre, Klas; Uhlin, Michael; Önfelt, Björn

    2016-01-01

    Here, we report a screening platform for assessment of the cytotoxic potential of individual natural killer (NK) cells within larger populations. Human primary NK cells were distributed across a silicon–glass microchip containing 32,400 individual microwells loaded with target cells. Through fluorescence screening and automated image analysis, the numbers of NK and live or dead target cells in each well could be assessed at different time points after initial mixing. Cytotoxicity was also studied by time-lapse live-cell imaging in microwells quantifying the killing potential of individual NK cells. Although most resting NK cells (≈75%) were non-cytotoxic against the leukemia cell line K562, some NK cells were able to kill several (≥3) target cells within the 12-h long experiment. In addition, the screening approach was adapted to increase the chance to find and evaluate serial killing NK cells. Even if the cytotoxic potential varied between donors, it was evident that a small fraction of highly cytotoxic NK cells were responsible for a substantial portion of the killing. We demonstrate multiple assays where our platform can be used to enumerate and characterize cytotoxic cells, such as NK or T cells. This approach could find use in clinical applications, e.g., in the selection of donors for stem cell transplantation or generation of highly specific and cytotoxic cells for adoptive immunotherapy. PMID:27092139

  17. Myrtus comunis and Eucalyptus camaldulensis cytotoxicity on breast cancer cells

    Directory of Open Access Journals (Sweden)

    Hrubik Jelena D.

    2012-01-01

    Full Text Available In vitro cytotoxicity of methanol, ethyl acetate, n-buthanol, and water extracts of Myrtus communis L. and Eucalyptus camaldulensis Dehnh. was examined against two human breast cancer cell lines (MCF 7 and MDA-MB-231 using MTT and SRB assays. The results showed significant cytotoxic potential of examined extracts, with IC50 values ranging from 7 to 138 μg/ml for M. communis and 3-250 μg/ml for E. camaldulensis. The two plants generally expressed similar activity, and no significant difference in cell line’s sensitivity towards extracts was observed. The results indicate to M. communis and E. camaldulensis as candidates for thorough chemical analyses for identification of active compounds, and eventually for attention in the process of discovery of new natural products in the control of cancer. [Projekat Ministarstva nauke Republike Srbije, br. 173037 i br. 172058

  18. Cytotoxicity study of pyrazole derivatives

    Directory of Open Access Journals (Sweden)

    Nusrat Binta Ahasan

    2007-06-01

    Full Text Available Pyrazolone heterocyclic compound, 3-methyl-1-phenyl-2-pyrazoline-5-one 2(a was synthesized by condensation reaction between ethyl acetoacetate and phenyl hydrazine and was converted into their corresponding heterocyclic derivatives 2(b to 2(f2 . Their cytotoxicity effects were measured by brine shrimp lethality bioassay. Among them the compounds 2(b , 2(f1 , and 2(f2 were highly active according to IC50 values 19.50, 19.50 and 20 ppm respectively. The rest of compounds 2(a , 2(c , 2(d1 , and 2(d2 having IC50 values 38, 33.50, 37.50, 36, 37.50 and 36 ppm in that order, were moderately active.

  19. Cytotoxicity study of pyrazole derivatives

    Directory of Open Access Journals (Sweden)

    Nusrat Binta Ahasan and Md. Rabiul Islam

    2007-12-01

    Full Text Available Pyrazolone heterocyclic compound, 3-methyl-1-phenyl-2-pyrazoline-5-one 2(a was synthesized by condensation reaction between ethyl acetoacetate and phenyl hydrazine and was converted into their corresponding heterocyclic derivatives 2(b to 2(f2. Their cytotoxicity effects were measured by brine shrimp lethality bioassay. Among them the compounds 2(b, 2(f1, and 2(f2 were highly active according to IC50 values 19.50, 19.50 and 20 ppm respectively. The rest of compounds 2(a, 2(c, 2(d1, and 2(d2 having IC50 values 38, 33.50, 37.50, 36, 37.50 and 36 ppm in that order, were moderately active.

  20. Cytotoxicity and Effects on Cell Viability of Nickel Nanowires

    KAUST Repository

    Rodriguez, Jose E.

    2013-05-01

    Recently, magnetic nanoparticles are finding an increased use in biomedical applications and research. Nanobeads are widely used for cell separation, biosensing and cancer therapy, among others. Due to their properties, nanowires (NWs) are gaining ground for similar applications and, as with all biomaterials, their cytotoxicity is an important factor to be considered before conducting biological studies with them. In this work, the cytotoxic effects of nickel NWs (Ni NWs) were investigated in terms of cell viability and damage to the cellular membrane. Ni NWs with an average diameter of 30-34 nm were prepared by electrodeposition in nanoporous alumina templates. The templates were obtained by a two-step anodization process with oxalic acid on an aluminum substrate. Characterization of NWs was done using X-Ray diffraction (XRD) and energy dispersive X-Ray analysis (EDAX), whereas their morphology was observed with scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Cell viability studies were carried out on human colorectal carcinoma cells HCT 116 by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) cell proliferation colorimetric assay, whereas the lactate dehydrogenase (LDH) homogenous membrane fluorimetric assay was used to measure the degree of cell membrane rupture. The density of cell seeding was calculated to obtain a specific cell number and confluency before treatment with NWs. Optical readings of the cell-reduced MTT products were measured at 570 nm, whereas fluorescent LDH membrane leakage was recorded with an excitation wavelength of 525 nm and an emission wavelength of 580 - 640 nm. The effects of NW length, cell exposure time, as well as NW:cell ratio, were evaluated through both cytotoxic assays. The results show that cell viability due to Ni NWs is affected depending on both exposure time and NW number. On the other hand, membrane rupture and leakage was only significant at later exposure times. Both

  1. Cytotoxicity and inhibitory properties against topoisomerase II of doxorubicin and its formamidine derivatives.

    Science.gov (United States)

    Kik, Krzysztof; Studzian, Kazimierz; Wasowska-Łukawska, Małgorzata; Oszczapowicz, Irena; Szmigiero, Leszek

    2009-01-01

    This work was undertaken to compare cytotoxicity, DNA damaging properties and effect on DNA cleavage by topoisomerase II of the anthracycline drug doxorubicin (DOX) and its two derivatives with a formamidino group containing a cyclic amine moiety such as morpholine (DOXM) or hexamethyleneimine (DOXH). The tetrazolium dye colorimetric assay was used to determine the cytotoxic activity of anthracyclines toward L1210 leukemia cells. DNA damage was measured by alkaline elution technique. The effect of anthracyclines on DNA cleavage was studied in a cell-free system containing supercoiled pBR322 DNA and purified human topoisomerase II. The cytotoxicity data and the results of studies on the mechanism of DNA break formation by anthracyclines at the cellular level and in the cell-free system showed that the presence of the formamidino group in the doxorubicin molecule reduced its ability to stimulate DNA cleavage by DNA topoisomerase II. DNA topoisomerase II is not a primary cellular target for DOXM or DOXH. An advantageous feature of formamidinoanthracyclines is their mechanism of cytotoxic action which is not related to the inhibition of DNA topoisomerase II. Therefore this class of anthracyclines seems to be a good source for selection of an anticancer drug directed toward cancer cells with the developed multidrug resistance attributed to the presence of altered DNA topoisomerase II.

  2. Glycoengineering of therapeutic antibodies enhances monocyte/macrophage-mediated phagocytosis and cytotoxicity.

    Science.gov (United States)

    Herter, Sylvia; Birk, Martina C; Klein, Christian; Gerdes, Christian; Umana, Pablo; Bacac, Marina

    2014-03-01

    Therapeutic Abs possess several clinically relevant mechanisms of action including perturbation of tumor cell signaling, activation of complement-dependent cytotoxicity, Ab-dependent cellular cytotoxicity (ADCC), Ab-dependent cellular phagocytosis (ADCP), and induction of adaptive immunity. In view of the important role of phagocytic lineage cells in the mechanism of action of therapeutic Abs, we analyzed FcγR receptor-dependent effector functions of monocytes and macrophages triggered by glycoengineered (GE) Abs (having enhanced FcγRIIIa [CD16a] binding affinity) versus their wild-type (WT) counterparts under different experimental conditions. We first defined the precise FcγR repertoire on classical and nonclassical intermediate monocytes--M1 and M2c macrophage populations. We further show that WT and GE Abs display comparable binding and induce similar effector functions (ADCC and ADCP) in the absence of nonspecific, endogenous IgGs. However, in the presence of these IgGs (i.e., in a situation that more closely mimics physiologic conditions), GE Abs display significantly superior binding and promote stronger monocyte and macrophage activity. These data show that in addition to enhancing CD16a-dependent NK cell cytotoxicity, glycoengineering also enhances monocyte and macrophage phagocytic and cytotoxic activities through enhanced binding to CD16a under conditions that more closely resemble the physiologic setting.

  3. Cellularized Cellular Solids via Freeze-Casting.

    Science.gov (United States)

    Christoph, Sarah; Kwiatoszynski, Julien; Coradin, Thibaud; Fernandes, Francisco M

    2016-02-01

    The elaboration of metabolically active cell-containing materials is a decisive step toward the successful application of cell based technologies. The present work unveils a new process allowing to simultaneously encapsulate living cells and shaping cell-containing materials into solid-state macroporous foams with precisely controlled morphology. Our strategy is based on freeze casting, an ice templating materials processing technique that has recently emerged for the structuration of colloids into macroporous materials. Our results indicate that it is possible to combine the precise structuration of the materials with cellular metabolic activity for the model organism Saccharomyces cerevisiae. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Epigenetics and Cellular Metabolism

    Directory of Open Access Journals (Sweden)

    Wenyi Xu

    2016-01-01

    Full Text Available Living eukaryotic systems evolve delicate cellular mechanisms for responding to various environmental signals. Among them, epigenetic machinery (DNA methylation, histone modifications, microRNAs, etc. is the hub in transducing external stimuli into transcriptional response. Emerging evidence reveals the concept that epigenetic signatures are essential for the proper maintenance of cellular metabolism. On the other hand, the metabolite, a main environmental input, can also influence the processing of epigenetic memory. Here, we summarize the recent research progress in the epigenetic regulation of cellular metabolism and discuss how the dysfunction of epigenetic machineries influences the development of metabolic disorders such as diabetes and obesity; then, we focus on discussing the notion that manipulating metabolites, the fuel of cell metabolism, can function as a strategy for interfering epigenetic machinery and its related disease progression as well.

  5. Increased Peripheral Blood Pro-Inflammatory/Cytotoxic Lymphocytes in Children with Bronchiectasis.

    Directory of Open Access Journals (Sweden)

    G Hodge

    Full Text Available Bronchiectasis (BE in children is common in some communities including Indigenous children in Australia. Relatively little is known about the nature of systemic inflammation in these children, especially the contribution of specific pro-inflammatory and cytotoxic lymphocyte subsets: T-cells, natural killer (NK cells and NKT-like cells. We have shown that these cells produce increased cytotoxic (granzyme b and perforin and inflammatory (IFNγ and TNFα mediators in several adult chronic lung diseases and hypothesised that similar changes would be evident in children with BE.Intracellular cytotoxic mediators perforin and granzyme b and pro-inflammatory cytokines were measured in T cell subsets, NKT-like and NK cells from blood and bronchoalveolar samples from 12 children with BE and 10 aged-matched control children using flow cytometry.There was a significant increase in the percentage of CD8+ T cells and T and NKT-like subsets expressing perforin/granzyme and IFNγ and TNFα in blood in BE compared with controls. There was a further increase in the percentage of pro-inflammatory cytotoxic T cells in Indigenous compared with non-Indigenous children. There was no change in any of these mediators in BAL.Childhood bronchiectasis is associated with increased systemic pro-inflammatory/cytotoxic lymphocytes in the peripheral blood. Future studies need to examine the extent to which elevated levels of pro-inflammatory cytotoxic cells predict future co-morbidities.

  6. Cytotoxic Activity of Selected Iranian Traditional Medicinal Plants on Colon, Colorectal and Breast Cancer Cell Lines

    Directory of Open Access Journals (Sweden)

    Leila Mohammad Taghizadeh Kashani

    2014-11-01

    Full Text Available Background: Many natural products from plants have been recognized to exert anticancer activity. In this study, ethanolic extracts of selected medicinal herbs from Iranian flora including Alyssum homolocarpum Fisch. (from seeds, Urtica dioica L. (from aerial parts, Cichorium intybus L. (from roots and Solanum nigrum L. (from fruits, were evaluated for their cytotoxic effect on different cell lines.Methods: Cytotoxic effect of these extracts was studied on three different cancer cell lines; colon carcinoma (HT-29, colorectal adenocarcinoma (Caco-2 and breast ductal carcinoma (T47D. In addition, Swiss mouse embryo fibroblasts (NIH 3T3 were used as normal nonmalignant cells. MTT assay (3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide was utilized for calculating the cytotoxicity of extracts on cell lines.Results: Results showed the potent cytotoxic activity of U. dioica ethanolic extract against T47D cell line with IC50 value of 46.14±4.55 µg/ml. Other extracts showed poor activity with IC50>100 µg/ml.Conclusions: Cytotoxic activity recorded in the present study revealed high potential antiproliferative activity of U. dioica ethanolic extract against T47D cell line. The real IC50 values of this extract may be considerably lower than the IC50 measured in our study if its pharmacological active compounds become pure. The results emphasize the importance of studies on U. dioica ethanolic extract to characterize potential components as cytotoxic natural medicines.

  7. Overview of cellular automaton models for corrosion

    International Nuclear Information System (INIS)

    Perez-Brokate, Cristian Felipe; De Lamare, Jacques; Dung di Caprio; Feron, Damien; Chausse, Annie

    2014-01-01

    A review of corrosion process modeling using cellular automata methods is presented. This relatively new and growing approach takes into account the stochastic nature of the phenomena and uses physico-chemical rules to make predictions at a mesoscopic scale. Milestone models are analyzed and perspectives are established. (authors)

  8. Acrolein cytotoxicity in hepatocytes involves endoplasmic reticulum stress, mitochondrial dysfunction and oxidative stress

    OpenAIRE

    Mohammad, Mohammad K; Avila, Diana; Zhang, Jingwen; Barve, Shirish; Arteel, Gavin; McClain, Craig; Joshi-Barve, Swati

    2012-01-01

    Acrolein is a common environmental, food and water pollutant and a major component of cigarette smoke. Also, it is produced endogenously via lipid peroxidation and cellular metabolism of certain amino acids and drugs. Acrolein is cytotoxic to many cell types including hepatocytes; however the mechanisms are not fully understood. We examined the molecular mechanisms underlying acrolein hepatotoxicity in primary human hepatocytes and hepatoma cells. Acrolein, at pathophysiological concentration...

  9. Wireless Cellular Mobile Communications

    Directory of Open Access Journals (Sweden)

    V. Zalud

    2002-12-01

    Full Text Available In this article is briefly reviewed the history of wireless cellularmobile communications, examined the progress in current secondgeneration (2G cellular standards and discussed their migration to thethird generation (3G. The European 2G cellular standard GSM and itsevolution phases GPRS and EDGE are described somewhat in detail. Thethird generation standard UMTS taking up on GSM/GPRS core network andequipped with a new advanced access network on the basis of codedivision multiple access (CDMA is investigated too. A sketch of theperspective of mobile communication beyond 3G concludes this article.

  10. Effects of daratumumab on natural killer cells and impact on clinical outcomes in relapsed or refractory multiple myeloma

    DEFF Research Database (Denmark)

    Casneuf, Tineke; Xu, Xu Steven; Adams, Homer C

    2017-01-01

    Daratumumab, a human CD38 imunoglobulin G 1κ monoclonal antibody, has demonstrated clinical activity and a manageable safety profile in monotherapy and combination therapy clinical trials in relapsed and/or refractory multiple myeloma. CD38 is expressed at high levels on myeloma cells and......, to a lesser extent, on immune effector cells, including natural killer (NK) cells, which are important for daratumumab-mediated antibody-dependent cellular cytotoxicity (ADCC). Here, the pharmacodynamic effects of daratumumab monotherapy on NK cells, and the effect of NK cell dynamics on daratumumab efficacy...

  11. Dynamics and mechanisms of quantum dot nanoparticle cellular uptake

    Directory of Open Access Journals (Sweden)

    Telford William G

    2010-06-01

    Full Text Available Abstract Background The rapid growth of the nanotechnology industry and the wide application of various nanomaterials have raised concerns over their impact on the environment and human health. Yet little is known about the mechanism of cellular uptake and cytotoxicity of nanoparticles. An array of nanomaterials has recently been introduced into cancer research promising for remarkable improvements in diagnosis and treatment of the disease. Among them, quantum dots (QDs distinguish themselves in offering many intrinsic photophysical properties that are desirable for targeted imaging and drug delivery. Results We explored the kinetics and mechanism of cellular uptake of QDs with different surface coatings in two human mammary cells. Using fluorescence microscopy and laser scanning cytometry (LSC, we found that both MCF-7 and MCF-10A cells internalized large amount of QD655-COOH, but the percentage of endocytosing cells is slightly higher in MCF-7 cell line than in MCF-10A cell line. Live cell fluorescent imaging showed that QD cellular uptake increases with time over 40 h of incubation. Staining cells with dyes specific to various intracellular organelles indicated that QDs were localized in lysosomes. Transmission electron microscopy (TEM images suggested a potential pathway for QD cellular uptake mechanism involving three major stages: endocytosis, sequestration in early endosomes, and translocation to later endosomes or lysosomes. No cytotoxicity was observed in cells incubated with 0.8 nM of QDs for a period of 72 h. Conclusions The findings presented here provide information on the mechanism of QD endocytosis that could be exploited to reduce non-specific targeting, thereby improving specific targeting of QDs in cancer diagnosis and treatment applications. These findings are also important in understanding the cytotoxicity of nanomaterials and in emphasizing the importance of strict environmental control of nanoparticles.

  12. Chlorpromazine inhibits tumour necrosis factor synthesis and cytotoxicity in vitro.

    Science.gov (United States)

    Zinetti, M; Galli, G; Demitri, M T; Fantuzzi, G; Minto, M; Ghezzi, P; Alzani, R; Cozzi, E; Fratelli, M

    1995-11-01

    Chlorpromazine (CPZ) has been previously shown to protect against endotoxin [lipopolysaccharide (LPS)] lethality and inhibit the release of tumour necrosis factor in vivo. We investigated at the cellular level whether this was due to direct inhibition of tumour necrosis factor-alpha (TNF-alpha) synthesis, using LPS-stimulated THP-1 human monocytic leukemia cells. We also studied the effect of CPZ on human TNF-alpha action by assessing TNF-alpha cytotoxicity on mouse fibrosarcoma L929 cells. CPZ (1-100 microM) inhibited TNF-alpha production in THP-1 cells in a dose dependent manner by a maximum of 80%. This effect was comparable to that of two well-known inhibitory drugs, dexamethasone and cyclicAMP. Inhibition was also evident at the mRNA level. On the other hand CPZ (10-25 microM) also inhibited TNF-alpha activity: in fact it reduced the cytotoxicity of TNF-alpha on L929 cells (EC50 was increased four times) and could provide protection even as a post-treatment. CPZ inhibited TNF-induced apoptosis in L929 cells, as detected by analysis of nuclear morphology. However, since we showed that apoptosis was very limited, and was not the main mode of cell death in our conditions, this could not explain the overall protection. Since CPZ did not interfere with either the oligomerization state of TNF-alpha or its receptor binding, our data suggest that it reduced cytotoxicity by inhibiting some steps in the TNF-alpha signalling pathways.

  13. In vitro cytotoxity of silver: implication for clinical wound care.

    Science.gov (United States)

    Poon, Vincent K M; Burd, Andrew

    2004-03-01

    In this study, we look at the cytotoxic effects of silver on keratinocytes and fibroblasts. We have assessed the viability of monolayer cultures using the MTT and BrdU assays. The composition of the culture medium and also the culture technique were modified to assess the effects of culture 'environment' on the susceptibility of the cells to the toxic action of silver. Further in vitro, experiments were performed using tissue culture models to allow cellular behavior in three dimensional planes which more closely simulated in vivo behavior. The silver source was both silver released from silver nitrate solution but also nanocrystalline silver released from a commercially available dressing. The results show that silver is highly toxic to both keratinocytes and fibroblasts in monolayer culture. When using optimized and individualized culture the fibroblasts appear to be more sensitive to silver than keratinocytes. However, when both cell types were grown in the same medium their viability was the same. Using tissue culture models again indicated an 'environmental effect' with decreased sensitivity of the cells to the cytotoxic effects of the silver. Nevertheless in these studies the toxic dose of skin cells ranging from 7 x 10(-4) to 55 x 10(-4)% was similar to that of bacteria. These results suggest that consideration of the cytotoxic effects of silver and silver-based products should be taken when deciding on dressings for specific wound care strategies. This is important when using keratinocyte culture, in situ, which is playing an increasing role in contemporary wound and burn care.

  14. Cytotoxic Effects of Bangladeshi Medicinal Plant Extracts

    Directory of Open Access Journals (Sweden)

    Shaikh J. Uddin

    2011-01-01

    Full Text Available 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.

  15. Radiolabelled cellular blood elements

    International Nuclear Information System (INIS)

    Sinzinger, H.

    1990-01-01

    This book reports on radiolabelled cellular blood elements, covering new advances made during the past several years, in particular the use of Tc-99 as a tracer for blood elements. Coverage extends to several radiolabelled monoclonal antibodies that are specific for blood components and may label blood elements in vivo

  16. Building synthetic cellular organization

    OpenAIRE

    Polka, Jessica K.; Silver, Pamela A.

    2013-01-01

    The elaborate spatial organization of cells enhances, restricts, and regulates protein–protein interactions. However, the biological significance of this organization has been difficult to study without ways of directly perturbing it. We highlight synthetic biology tools for engineering novel cellular organization, describing how they have been, and can be, used to advance cell biology.

  17. Genetic Dominance & Cellular Processes

    Science.gov (United States)

    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…

  18. Artocarpin Induces Apoptosis in Human Cutaneous Squamous Cell Carcinoma HSC-1 Cells and Its Cytotoxic Activity Is Dependent on Protein-Nutrient Concentration

    Directory of Open Access Journals (Sweden)

    Stephen Chu-Sung Hu

    2015-01-01

    Full Text Available Artocarpin, a natural prenylated flavonoid, has been shown to have various biological properties. However, its effects on human cutaneous squamous cell carcinoma (SCC have not been previously investigated. We set out to determine whether artocarpin has cytotoxic effects on SCC cells and whether its pharmacological activity is dependent on protein-nutrient concentration. Our results showed that treatment of HSC-1 cells (a human cutaneous SCC cell line with artocarpin decreased cell viability and induced cell apoptosis by increasing caspase 3/7 activity. These effects were more pronounced at low fetal bovine serum (FBS concentrations. Artocarpin induced an increase in the level of phospho-p38 and a decrease in the levels of phospho-ERK, phospho-JNK, phospho-Akt, phospho-mTOR, and phospho-S6K. High FBS concentrations in the culture media inhibited and delayed the uptake of artocarpin from the extracellular compartment (culture media into the intracellular compartment, as determined by high performance liquid chromatography (HPLC analysis. In conclusion, artocarpin induces apoptosis in HSC-1 cells through modulation of MAPK and Akt/mTOR pathways. Binding of artocarpin to proteins in the FBS may inhibit cellular uptake and reduce the cytotoxic activity of artocarpin on HSC-1 cells. Therefore, artocarpin may have potential use in the future as a form of treatment for cutaneous SCC.

  19. Characteristics and cytotoxicity of folate-modified curcumin-loaded PLA-PEG micellar nano systems with various PLA:PEG ratios.

    Science.gov (United States)

    Phan, Quoc Thong; Le, Mai Huong; Le, Thi Thu Huong; Tran, Thi Hong Ha; Xuan, Phuc Nguyen; Ha, Phuong Thu

    2016-06-30

    Targeting delivery system use natural drugs for tumor cells is an appealing platform help to reduce the side effects and enhance the therapeutic effects of the drug. In this study, we synthesized curcumin (Cur) loaded (D, L Poly lactic - Poly ethylenglycol) micelle (Cur/PLA-PEG) with the ratio of PLA/PEG of 3:1 2:1 1:1 1:2 and 1:3 (w/w) and another micelle modified by folate (Cur/PLA-PEG-Fol) for targeting cancer therapy. The PLA-PEG copolymer was synthesized by ring opening polymerization method. After loading onto the micelle, solubility of Cur increased from 0.38 to 0.73mgml(-1). The average size of prepared Cur/PLA-PEG micelles was from 60 to 69nm (corresponding to the ratio difference of PLA/PEG) and the drug encapsulating efficiency was from 48.8 to 91.3%. Compared with the Cur/PLA-PEG micelles, the size of Cur/PLA-PEG-Fol micelles were from 80 to 86nm and showed better in vitro cellular uptake and cytotoxicity towards HepG2 cells. The cytotoxicity of the NPs however depends much on the PEG component. The results demonstrated that Folate-modified micelles could serve as a potential nano carrier to improve solubility, anti-cancer activity of Cur and targeting ability of the system. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Cellular structures in a system of interacting particles

    International Nuclear Information System (INIS)

    Lev, B.I.

    2009-01-01

    The general description of the formation of a cellular structure in the system of interacting particles is proposed. The analytical results for possible cellular structures in the usual colloidal systems, systems of particles immersed in a liquid crystal, and gravitational systems have been presented. It is shown that the formation of a cellular structure in all systems of interacting particles at different temperatures and concentrations of particles has the same physical nature

  1. Synthesis, Characterization, and Cytotoxicity of Iron Oxide Nanoparticles

    Directory of Open Access Journals (Sweden)

    S. Kanagesan

    2013-01-01

    Full Text Available In order to study the response of human breast cancer cells' exposure to nanoparticle, iron oxide (α-Fe2O3 nanoparticles were synthesized by a simple low temperature combustion method using Fe(NO33·9H2O as raw material. X-ray diffraction studies confirmed that the resultant powders are pure α-Fe2O3. Transmission electron microscopy study revealed the spherical shape of the primary particles, and the size of the iron oxide nanoparticles is in the range of 19 nm. The magnetic hysteresis loops demonstrated that the sample exposed ferromagnetic behaviors with a relatively low coercivity. The cytotoxicity of α-Fe2O3 nanoparticle was also evaluated on human breast cancer cells to address the current deficient knowledge of cellular response to nanoparticle exposure.

  2. Cytotoxic effects of nickel nanowires in human fibroblasts

    KAUST Repository

    Felix Servin, Laura P.

    2016-03-09

    The increasing interest in the use of magnetic nanostructures for biomedical applications necessitates rigorous studies to be carried out in order to determine their potential toxicity. This work attempts to elucidate the cytotoxic effects of nickel nanowires (NWs) in human fibroblasts WI-38 by a colorimetric assay (MTT) under two different parameters: NW concentration and exposure time. This was complemented with TEM and confocal images to assess the NWs internalization and to identify any changes in the cell morphology. Ni NWs were fabricated by electrodeposition using porous alumina templates. Energy dispersive X-Ray analysis, scanning electron microscopy and transmission electron microscopy imaging were used for NW characterization. The results showed decreased cell metabolic activity for incubation times longer than 24 hours and no negative effects for exposure times shorter than that. The cytotoxicity effects for human fibroblasts were then compared with those reported for HCT 116 cells, and the findings point out that it is relevant to consider the cellular size. In addition, the present study compares the toxic effects of equivalent amounts of nickel in the form of its salt to those of NWs and shows that the NWs are more toxic than the salts. Internalized NWs were found in vesicles inside of the cells where their presence induced inflammation of the endoplasmic reticulum.

  3. A Cytotoxic Hydroperoxy Sterol from the Brown Alga, Nizamuddinia Zanardinii

    Directory of Open Access Journals (Sweden)

    Abdolhossein Rustaiyan

    2013-03-01

    Full Text Available Background:The marine environment is a unique source of bioactive natural products, of which Nizamuddinia zanardinii is an important brown algae distributed in Oman Sea. Literature revealed that there is no report on phytochemistry and pharmacology of this valuable algae.Methods:Bioguided fractionation of the methanolic extract of Nizamuddinia zanardinii, collected from Oman Sea, led to the isolation of a hydroperoxy sterol. Its structure was determined by analysis of the spectroscopic data as 24-hydroperoxy-24-vinyl cholesterol (HVC. In vitro cytotoxic activity of this compound was evaluated against HT29, MCF7, A549, HepG2 and MDBK cell lines.Results:Although 24(R-hydroproxy-24-vinylcholesterol has been previously reported from Sargassum and Padina species, it is the first report on the presence of this compound from N. zanardinii. This compound exhibited cytotoxicity in all cell lines (IC50, 3.62, 9.09, 17.96, 32.31 and 37.31 μg/mL respectively. HVC was also evaluated for apoptotic activity and demonstrated positive results in terminal deoxynucleotidyl transferase dUTP Nick End labeling (TUNEL assay suggesting it a candidate for further apoptotic studies.Conclusions:Nizamuddinia zanardinii, a remarkable brown algae of Oman Sea, is a good source of hydroproxy sterols with promising cytotoxic on various cell lines particularly human colon adenocarcinoma.

  4. In vitro cytotoxic screening of selected Saudi medicinal plants.

    Science.gov (United States)

    Almehdar, Hussein; Abdallah, Hossam M; Osman, Abdel-Moneim M; Abdel-Sattar, Essam A

    2012-04-01

    Many natural products from plants have been identified to exert anticancer activity. It might be expected to be a challenge to look at the Saudi plants in order to discover new sources for new molecules which may have anticancer activity. The methanolic extracts of forty species of plants traditionally used in Saudi Arabia for the treatment of a variety of diseases were tested in vitro for their potential anticancer activity on different human cancer cell lines. The cytotoxic activity of the methanolic extracts of the tested plants were determined using three human cancer cell lines, namely, breast cancer (MCF7), hepatocellular carcinoma (HEPG2), and cervix cancer (HELA) cells. In addition, human normal melanocyte (HFB4) was used as normal nonmalignant cells. Sulforhodamine B colorimetric assay was used to evaluate the in vitro cytotoxic activity of the different extracts. The growth inhibition of 50% (IC(50)) for each extract was calculated from the optical density of treated and untreated cells. Doxorubicin, a broad-spectrum anticancer drug, was used as the positive control. Nine plant extracts were chosen for further fractionation based on their activity and availability. Interesting cytotoxic activity was observed for Hypoestes forskaolii, Withania somnifera, Solanum glabratum, Adenium obesum, Pistacia vera oleoresin, Caralluma quadrangula, Eulophia petersii, Phragmanthera austroarabica, and Asparagus officinalis. Other extracts showed poor activity.

  5. Antioxidant, Antitubercular and Cytotoxic Activities of Piper imperiale

    Directory of Open Access Journals (Sweden)

    Sanjib Bhakta

    2012-04-01

    Full Text Available Phenolic compounds are widely distributed in Nature and act as pharmacologically active constituents in many herbal medicines. They have multiple biological properties, most notably antioxidant, antibacterial and cytotoxic activities. In the present study an attempt to correlate the phenolic composition of leaf, flower and wood extracts of Piper imperiale, with antioxidant, antitubercular and cytotoxic activities was undertaken. The total phenol content ranged from 1.98 to 6.94 mg GAE/gDW among ethanolic extracts, and gallic acid, catechin, epicatechin, ferulic acid, resveratrol and quercetin were identified and quantified by HPLC. DPPH and ABTS assays showed high antioxidant activity of the leaf extract (EC50ABTS = 15.6 µg/mL, EC50DPPH = 27.3 µg/mL with EC50 in the same order of magnitude as the hydroxyquinone (EC50ABTS = 10.2 µg/mL, EC50DPPH = 15.7 µg/mL. The flower extract showed strong antimicrobial activity against Mycobacterium tuberculosis H37Rv. All the extracts exhibited dose-dependent cytotoxic effects against MCF-7 cancer cells. This is the first time that a Piper extract has been found to be highly active against M. tuberculosis. This study shows the biological potential of Piper imperiale extracts and gives way to bio-guided studies with well-defined biological activities.

  6. Cytotoxic diterpenoids from the roots of Salvia lachnocalyx

    Directory of Open Access Journals (Sweden)

    Hossein Hadavand Mirzaei

    Full Text Available ABSTRACT Salvia lachnocalyx Hedge, Lamiaceae, is an endemic sage which grows naturally in the Fars Province of Iran. The phytochemical analyses of the roots of S. lachnocalyx led to the isolation of five known diterpenoids: ferruginol (1, taxodione (2, sahandinone (3, 4-dehydrosalvilimbinol (4 and labda-7,14-dien-13-ol (5. Their chemical structures were elucidated using one (1H and 13C and two dimensional (COSY, HSQC and HMBC NMR spectroscopic data as well as electron impact mass spectra. The cytotoxicity of the purified compounds was evaluated against three human cancer cell lines; MOLT-4 (acute lymphoblastic leukemia, HT-29 (colorectal adenocarcinoma and MCF7 (breast adenocarcinoma and all of the isolated compounds showed considerable cytotoxic activity against these cell lines. Compounds 2 and 3 (IC50 range: 0.41–3.87 µg/ml with endocyclic α,β-unsaturated carbonyl functional group, exhibited the highest cytotoxic activities compared to the other compounds (IC50 range: 6.85–17.23 µg/ml. In conclusion, compounds 2 and 3 are presented as compounds that deserve further investigation of their biological activities.

  7. Antioxidant Capacity, Cytotoxicity, and Acute Oral Toxicity of Gynura bicolor

    Directory of Open Access Journals (Sweden)

    Wuen Yew Teoh

    2013-01-01

    Full Text Available Gynura bicolor (Compositae which is widely used by the locals as natural remedies in folk medicine has limited scientific studies to ensure its efficacy and nontoxicity. The current study reports the total phenolic content, antioxidant capacity, cytotoxicity, and acute oral toxicity of crude methanol and its fractionated extracts (hexane, ethyl acetate, and water of G. bicolor leaves. Five human colon cancer cell lines (HT-29, HCT-15, SW480, Caco-2, and HCT 116, one human breast adenocarcinoma cell line (MCF7, and one human normal colon cell line (CCD-18Co were used to evaluate the cytotoxicity of G. bicolor. The present findings had clearly demonstrated that ethyl acetate extract of G. bicolor with the highest total phenolic content among the extracts showed the strongest antioxidant activity (DPPH radical scavenging assay and metal chelating assay, possessed cytotoxicity, and induced apoptotic and necrotic cell death, especially towards the HCT 116 and HCT-15 colon cancer cells. The acute oral toxicity study indicated that methanol extract of G. bicolor has negligible level of toxicity when administered orally and has been regarded as safe in experimental rats. The findings of the current study clearly established the chemoprevention potential of G. bicolor and thus provide scientific validation on the therapeutic claims of G. bicolor.

  8. Natural Killer Dendritic Cells Enhance Immune Responses Elicited by α-Galactosylceramide-Stimulated Natural Killer T Cells

    Directory of Open Access Journals (Sweden)

    Sung Won Lee

    2013-01-01

    Full Text Available Natural killer dendritic cells (NKDCs possess potent anti-tumor activity, but the cellular effect of NKDC interactions with other innate immune cells is unclear. In this study, we demonstrate that the interaction of NKDCs and natural killer T (NKT cells is required for the anti-tumor immune responses that are elicited by α-galactosylceramide (α-GC in mice. The rapid and strong expression of interferon-γ by NKDCs after α-GC stimulation was dependent on NKT cells. Various NK and DC molecular markers and cytotoxic molecules were up-regulated following α-GC administration. This up-regulation could improve NKDC presentation of tumor antigens and increase cytotoxicity against tumor cells. NKDCs were required for the stimulation of DCs, NK cells, and NKT cells. The strong anti-tumor immune responses elicited by α-GC may be due to the down-regulation of regulatory T cells. Furthermore, the depletion of NKDCs dampened the tumor clearance mediated by α-GC-stimulated NKT cells in vivo. Taken together, these results indicate that complex interactions of innate immune cells might be required to achieve optimal anti-tumor immune responses during the early stages of tumorigenesis.

  9. Early spatiotemporal-specific changes in intermediate signals are predictive of cytotoxic sensitivity to TNFα and co-treatments

    Science.gov (United States)

    Loo, Lit-Hsin; Bougen-Zhukov, Nicola Michelle; Tan, Wei-Ling Cecilia

    2017-03-01

    Signaling pathways can generate different cellular responses to the same cytotoxic agents. Current quantitative models for predicting these differential responses are usually based on large numbers of intracellular gene products or signals at different levels of signaling cascades. Here, we report a study to predict cellular sensitivity to tumor necrosis factor alpha (TNFα) using high-throughput cellular imaging and machine-learning methods. We measured and compared 1170 protein phosphorylation events in a panel of human lung cancer cell lines based on different signals, subcellular regions, and time points within one hour of TNFα treatment. We found that two spatiotemporal-specific changes in an intermediate signaling protein, p90 ribosomal S6 kinase (RSK), are sufficient to predict the TNFα sensitivity of these cell lines. Our models could also predict the combined effects of TNFα and other kinase inhibitors, many of which are not known to target RSK directly. Therefore, early spatiotemporal-specific changes in intermediate signals are sufficient to represent the complex cellular responses to these perturbations. Our study provides a general framework for the development of rapid, signaling-based cytotoxicity screens that may be used to predict cellular sensitivity to a cytotoxic agent, or identify co-treatments that may sensitize or desensitize cells to the agent.

  10. Cellular Automata Ideas in Digital Circuits and Switching Theory.

    Science.gov (United States)

    Siwak, Pawel P.

    1985-01-01

    Presents two examples which illustrate the usefulness of ideas from cellular automata. First, Lee's algorithm is recalled and its cellular nature shown. Then a problem from digraphs, which has arisen from analyzing predecessing configurations in the famous Conway's "game of life," is considered. (Author/JN)

  11. Cytotoxic Autophagy in Cancer Therapy

    Directory of Open Access Journals (Sweden)

    Khushboo Sharma

    2014-06-01

    Full Text Available Autophagy is a process of cellular self-digestion, whereby the cell degrades subcellular materials in order to generate energy and metabolic precursors in order to prolong survival, classically under conditions of nutrient deprivation. Autophagy can also involve the degradation of damaged or aged organelles, and misfolded or damaged proteins to eliminate these components that might otherwise be deleterious to cellular survival. Consequently, autophagy has generally been considered a prosurvival response. Many, if not most chemotherapeutic drugs and radiation also promote autophagy, which is generally considered a cytoprotective response, in that its inhibition frequently promotes apoptotic cells death. Furthermore, it has been shown that conventional chemotherapeutic drugs and radiation alone rarely induce a form of autophagy that leads to cell death. However, there are multiple examples in the literature where newer chemotherapeutic agents, drug combinations or drugs in combination with radiation promote autophagic cell death. This review will describe autophagic cell death induced in breast tumor cells, lung cancer cells as well as glioblastoma, demonstrating that it cannot be concluded that stress induced autophagy is, of necessity, cytoprotective in function.

  12. A Mathematical Model for Cisplatin Cellular Pharmacodynamics

    Directory of Open Access Journals (Sweden)

    Ardith W. El-Kareh

    2003-03-01

    Full Text Available A simple theoretical model for the cellular pharmacodynamics of cisplatin is presented. The model, which takes into account the kinetics of cisplatin uptake by cells and the intracellular binding of the drug, can be used to predict the dependence of survival (relative to controls on the time course of extracellular exposure. Cellular pharmacokinetic parameters are derived from uptake data for human ovarian and head and neck cancer cell lines. Survival relative to controls is assumed to depend on the peak concentration of DNA-bound intracellular platinum. Model predictions agree well with published data on cisplatin cytotoxicity for three different cancer cell lines, over a wide range of exposure times. In comparison with previously published mathematical models for anticancer drug pharmacodynamics, the present model provides a better fit to experimental data sets including long exposure times (∼100 hours. The model provides a possible explanation for the fact that cell kill correlates well with area under the extracellular concentration-time curve in some data sets, but not in others. The model may be useful for optimizing delivery schedules and for the dosing of cisplatin for cancer therapy.

  13. Molecular, cellular, and tissue engineering

    CERN Document Server

    Bronzino, Joseph D

    2015-01-01

    Known as the bible of biomedical engineering, The Biomedical Engineering Handbook, Fourth Edition, sets the standard against which all other references of this nature are measured. As such, it has served as a major resource for both skilled professionals and novices to biomedical engineering. Molecular, Cellular, and Tissue Engineering, the fourth volume of the handbook, presents material from respected scientists with diverse backgrounds in molecular biology, transport phenomena, physiological modeling, tissue engineering, stem cells, drug delivery systems, artificial organs, and personalized medicine. More than three dozen specific topics are examined, including DNA vaccines, biomimetic systems, cardiovascular dynamics, biomaterial scaffolds, cell mechanobiology, synthetic biomaterials, pluripotent stem cells, hematopoietic stem cells, mesenchymal stem cells, nanobiomaterials for tissue engineering, biomedical imaging of engineered tissues, gene therapy, noninvasive targeted protein and peptide drug deliver...

  14. Gold Nanocluster-Mediated Cellular Death under Electromagnetic Radiation.

    Science.gov (United States)

    Cifuentes-Rius, Anna; Ivask, Angela; Das, Shreya; Penya-Auladell, Nuria; Fabregas, Laura; Fletcher, Nicholas L; Houston, Zachary H; Thurecht, Kristofer J; Voelcker, Nicolas H

    2017-11-29

    Gold nanoclusters (Au NCs) have become a promising nanomaterial for cancer therapy because of their biocompatibility and fluorescent properties. In this study, the effect of ultrasmall protein-stabilized 2 nm Au NCs on six types of mammalian cells (fibroblasts, B-lymphocytes, glioblastoma, neuroblastoma, and two types of prostate cancer cells) under electromagnetic radiation is investigated. Cellular association of Au NCs in vitro is concentration-dependent, and Au NCs have low intrinsic toxicity. However, when Au NC-incubated cells are exposed to a 1 GHz electromagnetic field (microwave radiation), cell viability significantly decreases, thus demonstrating that Au NCs exhibit specific microwave-dependent cytotoxicity, likely resulting from localized heating. Upon i.v. injection in mice, Au NCs are still present at 24 h post administration. Considering the specific microwave-dependent cytotoxicity and low intrinsic toxicity, our work suggests the potential of Au NCs as effective and safe nanomedicines for cancer therapy.

  15. Cytotoxicity of leukocytes from normal and Shigella-susceptible (opium-treated) guinea pigs against virulent Shigella sonnei.

    Science.gov (United States)

    Morgan, D R; DuPont, H L; Wood, L V; Kohl, S

    1984-01-01

    Intraepithelial lymphocytes were collected from the ileum of adult Hartley strain guinea pigs and used as effector cells in a 60-min bactericidal assay with virulent Shigella sonnei as target cells. Natural killer cytotoxicity (NKC) and antibody-dependent cellular cytotoxicity (ADCC) were measured and correlated with the resistance of the animals to infection by S. sonnei. Normal guinea pig intraepithelial lymphocytes exhibited mean NKC and ADCC values of 22.8 +/- 5.0 and 34.1 +/- 13.6, respectively. These animals were resistant to oral challenge with virulent S. sonnei. Intraepithelial lymphocytes from guinea pigs which were fasted for 4 days demonstrated NKC and ADCC values similar to those of normal animals (31.0 +/- 8.1 and 41.7 +/- 6.7, respectively). These animals also were resistant to oral challenge. Intraepithelial lymphocytes from guinea pigs which were given 1 ml of deodorized tincture of opium 2 h before cell collection demonstrated deficient NKC (4.7 +/- 4.2) and ADCC (5.3 +/- 4.9) values but remained resistant to infection by S. sonnei. When guinea pigs were fasted for 4 days and given opium, deficient NKC (2.0 +/- 2.0) and ADCC (1.3 +/- 1.3) values were demonstrated; this group of animals was susceptible to infection by S. sonnei (P less than 0.04). These experiments demonstrated that opium treatment depresses one form of gut immunity. When combined with starvation, opium treatment may increase susceptibility to infection by shigellae by modulation of immunity in addition to the effects on gut motility and bacterial flora. PMID:6384044

  16. IGF-1 promotes the development and cytotoxic activity of human NK cells

    OpenAIRE

    Ni, Fang; Sun, Rui; Fu, Binqing; Wang, Fuyan; Guo, Chuang; Tian, Zhigang; Wei, Haiming

    2013-01-01

    Insulin-like growth factor 1 (IGF-1) is a critical regulator of many physiological functions, ranging from longevity to immunity. However, little is known about the role of IGF-1 in natural killer cell development and function. Here, we identify an essential role for IGF-1 in the positive regulation of human natural killer cell development and cytotoxicity. Specifically, we show that human natural killer cells have the ability to produce IGF-1 and that differential endogenous IGF-1 expression...

  17. HPLC Quantification of Cytotoxic Compounds from Aspergillus niger

    Directory of Open Access Journals (Sweden)

    Paula Karina S. Uchoa

    2017-01-01

    Full Text Available A high-performance liquid chromatography method was developed and validated for the quantification of the cytotoxic compounds produced by a marine strain of Aspergillus niger. The fungus was grown in malt peptone dextrose (MPD, potato dextrose yeast (PDY, and mannitol peptone yeast (MnPY media during 7, 14, 21, and 28 days, and the natural products were identified by standard compounds. The validation parameters obtained were selectivity, linearity (coefficient of correlation > 0.99, precision (relative standard deviation below 5%, and accuracy (recovery > 96.

  18. Cytotoxic Metabolites from the Soil-Derived Fungus Exophiala Pisciphila

    Directory of Open Access Journals (Sweden)

    Xiu-Kun Lin

    2011-03-01

    Full Text Available A new polyketide compound 1 and a new naturally occurring chromone derivative 2, along with two known indole alkaloids 3–4 were characterized from the ethyl acetate extract of a soil-derived fungal strain, Exophiala pisciphila PHF-9. The structures of compounds 1–4 were established by detailed spectroscopic analysis and comparison with literature data. The absolute configuration of 1 was determined by a modified Mosher’s method. Compound 1 exhibited moderate cytotoxicity against A-549, Hela, PANC-28 and BEL-7402 cell lines.

  19. Molecular and Cellular Signaling

    CERN Document Server

    Beckerman, Martin

    2005-01-01

    A small number of signaling pathways, no more than a dozen or so, form a control layer that is responsible for all signaling in and between cells of the human body. The signaling proteins belonging to the control layer determine what kinds of cells are made during development and how they function during adult life. Malfunctions in the proteins belonging to the control layer are responsible for a host of human diseases ranging from neurological disorders to cancers. Most drugs target components in the control layer, and difficulties in drug design are intimately related to the architecture of the control layer. Molecular and Cellular Signaling provides an introduction to molecular and cellular signaling in biological systems with an emphasis on the underlying physical principles. The text is aimed at upper-level undergraduates, graduate students and individuals in medicine and pharmacology interested in broadening their understanding of how cells regulate and coordinate their core activities and how diseases ...

  20. Nested cellular automata

    International Nuclear Information System (INIS)

    Quasthoff, U.

    1985-07-01

    Cellular automata by definition consist of a finite or infinite number of cells, say of unit length, with each cell having the same transition function. These cells are usually considered as the smallest elements and so the space filled with these cells becomes discrete. Nevertheless, large pictures created by such cellular automata look very fractal. So we try to replace each cell by a couple of smaller cells, which have the same transition functions as the large ones. There are automata where this replacement does not destroy the macroscopic structure. In these cases this nesting process can be iterated. The paper contains large classes of automata with the above properties. In the case of one dimensional automata with two states and next neighbour interaction and a nesting function of the same type a complete classification is given. (author)

  1. Development of in vitro models for cellular and molecular studies in toxicology and chemoprevention

    Energy Technology Data Exchange (ETDEWEB)

    Mace, K.; Offord, E.A.; Harris, C.C.; Pfeifer, A.M.A. [Nestle Research Center, Lausanne (Switzerland)

    1998-12-31

    Many natural dietary phytochemicals found compounds found in fruits, vegetables, spices and tea have been shown in recent years to be protective against cancer in various animal models. In the light of the potential impact of these compounds on human health it is important to elucidate the mechanisms involved. We therefore developed and characterized relevant in vitro models using immortalized human epithelial cell lines derived from target tissues in carcinogenesis, such as lung, liver and colon. Assays were established, allowing the evaluation of the cytotoxic and genotoxic effects of various procarcinogens, including nitrosamines, mycotoxins and heterocyclic amines on these metabolically-competent human epithelial cell lines. These cellular models appeared to be a useful tool to study the capacity of certain food components to block the initiation stage of carcinogenesis. The ability of carnosol and carnosic acid from rosemary as well as the synthetic dithiolethione, oltipraz, to block the formation of DNA adducts, and their effects on the expression of phase I and phase II enzymes was investigated. We have observed that both rosemary extracts and oltiprax inhibited benzo(a)pyrene- or aflatoxin B{sub 1}-induced DNA adduct formation by strongly inhibiting CYP{sub 450} activities and inducing the expression of glutathione S-transferase. These results in human cell models give some insight into the different mechanisms involved in the chemopreventive action of both natural and synthetic compounds in relation to phase I and phase II enzymes. (orig.)

  2. Analysis of the Effects of Cell Stress and Cytotoxicity on In ...

    Science.gov (United States)

    Chemical toxicity can arise from disruption of specific biomolecular functions or through more generalized cell stress and cytotoxicity-mediated processes. Here, concentration-dependent responses of 1063 chemicals including pharmaceuticals, natural products, pesticidals, consumer, and industrial chemicals across a diverse battery of 821 in vitro assay endpoints from 7 high-throughput assay technology platforms were analyzed in order to better distinguish between these types of activities. Both cell-based and cell-free assays showed a rapid increase in the frequency of responses at concentrations where cell stress / cytotoxicity responses were observed in cell-based assays. Chemicals that were positive on at least two viability/cytotoxicity assays within the concentration range tested (typically up to 100 M) activated a median of 12% of assay endpoints while those that were not cytotoxic in this concentration range activated 1.3% of the assays endpoints. The results suggest that activity can be broadly divided into: (1) specific biomolecular interactions against one or more targets (e.g., receptors or enzymes) at concentrations below which overt cytotoxicity-associated activity is observed; and (2) activity associated with cell stress or cytotoxicity, which may result from triggering of specific cell stress pathways, chemical reactivity, physico-chemical disruption of proteins or membranes, or broad low-affinity non-covalent interactions. Chemicals showing a g

  3. Cytotoxic activity of some medicinal plants from hamedan district of iran.

    Science.gov (United States)

    Behzad, Sahar; Pirani, Atefeh; Mosaddegh, Mahmoud

    2014-01-01

    Medicinal plants have been investigated for possible anti-cancer effects. The aim of the present study was to examine the cytotoxic activity of several medicinal plants on different tumor cell lines. 11 selected plant species which have been used in folkloric prescriptions were collected from different sites of Hamedan district of Iran. The methanolic extracts of the plants were prepared and their cytotoxic effects on four human cancer cell lines (A549, human lung adenocarcinoma; MCF7, human breast adenocarcinoma; HepG2, hepatocellular carcinoma and HT-29, human colon carcinoma) and one normal cell line (MDBK, bovine kidney) were examined using the MTT assay. Three of these were exhibited antiproliferative activity against one or more of the cell lines. The extract from Primula auriculata demonstrated the highest cytotoxicity with IC50 of 25.79, 35.79 and 43.34 μg.mL-1 against MCF7, HepG2 and HT- 29 cells, respectively. For some of the plants, their traditional use was correlated with the cytotoxic results, whereas for others the results may support the non-cytotoxicity of species used traditionally as natural remedies. The cytotoxic species could be considered as potential of anticancer compounds.

  4. Predictability in cellular automata.

    Science.gov (United States)

    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.

  5. Probabilistic cellular automata.

    Science.gov (United States)

    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.

  6. Wavefront cellular learning automata.

    Science.gov (United States)

    Moradabadi, Behnaz; Meybodi, Mohammad Reza

    2018-02-01

    This paper proposes a new cellular learning automaton, called a wavefront cellular learning automaton (WCLA). The proposed WCLA has a set of learning automata mapped to a connected structure and uses this structure to propagate the state changes of the learning automata over the structure using waves. In the WCLA, after one learning automaton chooses its action, if this chosen action is different from the previous action, it can send a wave to its neighbors and activate them. Each neighbor receiving the wave is activated and must choose a new action. This structure for the WCLA is necessary in many dynamic areas such as social networks, computer networks, grid computing, and web mining. In this paper, we introduce the WCLA framework as an optimization tool with diffusion capability, study its behavior over time using ordinary differential equation solutions, and present its accuracy using expediency analysis. To show the superiority of the proposed WCLA, we compare the proposed method with some other types of cellular learning automata using two benchmark problems.

  7. Wavefront cellular learning automata

    Science.gov (United States)

    Moradabadi, Behnaz; Meybodi, Mohammad Reza

    2018-02-01

    This paper proposes a new cellular learning automaton, called a wavefront cellular learning automaton (WCLA). The proposed WCLA has a set of learning automata mapped to a connected structure and uses this structure to propagate the state changes of the learning automata over the structure using waves. In the WCLA, after one learning automaton chooses its action, if this chosen action is different from the previous action, it can send a wave to its neighbors and activate them. Each neighbor receiving the wave is activated and must choose a new action. This structure for the WCLA is necessary in many dynamic areas such as social networks, computer networks, grid computing, and web mining. In this paper, we introduce the WCLA framework as an optimization tool with diffusion capability, study its behavior over time using ordinary differential equation solutions, and present its accuracy using expediency analysis. To show the superiority of the proposed WCLA, we compare the proposed method with some other types of cellular learning automata using two benchmark problems.

  8. Pterostilbene-induced tumor cytotoxicity

    DEFF Research Database (Denmark)

    Mena, Salvador; Rodríguez, María L; Ponsoda, Xavier

    2012-01-01

    The phenolic phytoalexin resveratrol is well known for its health-promoting and anticancer properties. Its potential benefits are, however, limited due to its low bioavailability. Pterostilbene, a natural dimethoxylated analog of resveratrol, presents higher anticancer activity than resveratrol. ...

  9. Oxidative Mechanisms of Monocyte-Mediated Cytotoxicity

    Science.gov (United States)

    Weiss, Stephen J.; Lobuglio, Albert F.; Kessler, Howard B.

    1980-01-01

    Human monocytes stimulated with phorbol myristate acetate were able to rapidly destroy autologous erythrocyte targets. Monocyte-mediated cytotoxicity was related to phorbol myristate acetate concentration and monocyte number. Purified preparations of lymphocytes were incapable of mediating erythrocyte lysis in this system. The ability of phorbol myristate acetate-stimulated monocytes to lyse erythrocyte targets was markedly impaired by catalase or superoxide dismutase but not by heat-inactivated enzymes or albumin. Despite a simultaneous requirement for superoxide anion and hydrogen peroxide in the cytotoxic event, a variety of hydroxyl radical and singlet oxygen scavengers did not effect cytolysis. However, tryptophan significantly inhibited cytotoxicity. The myeloperoxidase inhibitor cyanide enhanced erythrocyte destruction, whereas azide reduced it modestly. The inability of cyanide to reduce cytotoxicity coupled with the protective effect of superoxide dismutase suggests that cytotoxicity is independent of the classic myeloperoxidase system. We conclude that monocytes, stimulated with phorbol myristate acetate, generate superoxide anion and hydrogen peroxide, which together play an integral role in this cytotoxic mechanism.

  10. Environment Aware Cellular Networks

    KAUST Repository

    Ghazzai, Hakim

    2015-02-01

    The unprecedented rise of mobile user demand over the years have led to an enormous growth of the energy consumption of wireless networks as well as the greenhouse gas emissions which are estimated currently to be around 70 million tons per year. This significant growth of energy consumption impels network companies to pay huge bills which represent around half of their operating expenditures. Therefore, many service providers, including mobile operators, are looking for new and modern green solutions to help reduce their expenses as well as the level of their CO2 emissions. Base stations are the most power greedy element in cellular networks: they drain around 80% of the total network energy consumption even during low traffic periods. Thus, there is a growing need to develop more energy-efficient techniques to enhance the green performance of future 4G/5G cellular networks. Due to the problem of traffic load fluctuations in cellular networks during different periods of the day and between different areas (shopping or business districts and residential areas), the base station sleeping strategy has been one of the main popular research topics in green communications. In this presentation, we present several practical green techniques that provide significant gains for mobile operators. Indeed, combined with the base station sleeping strategy, these techniques achieve not only a minimization of the fossil fuel consumption but also an enhancement of mobile operator profits. We start with an optimized cell planning method that considers varying spatial and temporal user densities. We then use the optimal transport theory in order to define the cell boundaries such that the network total transmit power is reduced. Afterwards, we exploit the features of the modern electrical grid, the smart grid, as a new tool of power management for cellular networks and we optimize the energy procurement from multiple energy retailers characterized by different prices and pollutant

  11. Acinetobacter baumannii and A. pittii clinical isolates lack adherence and cytotoxicity to lung epithelial cells in vitro.

    Science.gov (United States)

    Lázaro-Díez, María; Navascués-Lejarza, Teresa; Remuzgo-Martínez, Sara; Navas, Jesús; Icardo, José Manuel; Acosta, Felix; Martínez-Martínez, Luis; Ramos-Vivas, José

    2016-09-01

    The molecular and genetic basis of Acinetobacter baumannii and Acinetobacter pittii virulence remains poorly understood, and there is still lack of knowledge in host cell response to these bacteria. In this study, we have used eleven clinical Acinetobacter strains (A. baumannii n = 5; A. pittii n = 6) to unravel bacterial adherence, invasion and cytotoxicity to human lung epithelial cells. Our results showed that adherence to epithelial cells by Acinetobacter strains is scarce and cellular invasion was not truly detected. In addition, all Acinetobacter strains failed to induce any cytotoxic effect on A549 cells. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  12. Pingyangmycin and Bleomycin Share the Same Cytotoxicity Pathway

    Directory of Open Access Journals (Sweden)

    Yanli He

    2016-06-01

    Full Text Available 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.

  13. Cosserat modeling of cellular solids

    NARCIS (Netherlands)

    Onck, P.R.

    Cellular solids inherit their macroscopic mechanical properties directly from the cellular microstructure. However, the characteristic material length scale is often not small compared to macroscopic dimensions, which limits the applicability of classical continuum-type constitutive models. Cosserat

  14. Evaluation of Structural Cellular Glass

    Science.gov (United States)

    Adams, M. A.; Zwissler, J. G.

    1984-01-01

    Preliminary design information presented. First report discusses state of structural-cellular-glass programs as of June 1979. Second report gives further details of program to develop improved cellular glasses and to characterize properties of glasses and commercially available materials.

  15. Cytotoxicity of Cerastes cerastes snake venom: Involvement of imbalanced redox status.

    Science.gov (United States)

    Kebir-Chelghoum, Hayet; Laraba-Djebari, Fatima

    2017-09-01

    Envenomation caused by Cerastes cerastes snake venom is characterized by a local and a systemic tissue damage due to myonecrosis, hemorrhage, edema and acute muscle damage. The present study aimed to evaluate the relationship between the pro/anti-oxidants status and the cytotoxicity of C. cerastes snake venom. The in vivo cytotoxicity analysis was undertaken by the injection of C. cerastes venom (48μg/20g body weight) by i.p. route, mice were then sacrificed at 3, 24 and 48h post injection, organs were collected for further analysis. In vitro cytotoxicity analysis was investigated on cultured PBMC, hepatocytes and isolated liver. The obtained results showed a significant cell infiltration characterized by a significant increase of myeloperoxidase (MPO) and eosinoperoxidase (EPO) activities. These results showed also a potent oxidative activity of C. cerastes venom characterized by increased levels of residual nitrites and lipid peroxidation associated with a significant decrease of glutathione and catalase activity in sera and tissues (heart, lungs, liver and kidneys). The in vitro cytotoxicity of C. cerastes venom on PBMC seems to be dose-dependent (IC50 of 21μg/ml/10 6 cells) and correlated with an imbalanced redox status at high doses of venom. However, in the case of cultured hepatocytes, the LDH release and oxidative stress were observed only at high doses of the venom. The obtained results of in vivo study were confirmed by the culture of isolated liver. Therefore, these results suggest that the venom induces a direct cytotoxic effect which alters the membrane integrity causing a leakage of the cellular contents. This cytotoxic effect can lead indirectly to inflammatory response and oxidative stress. These data suggest that an early anti-inflammatory and antioxidant treatment could be useful in the management of envenomed victims. Copyright © 2017. Published by Elsevier B.V.

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

    International Nuclear Information System (INIS)

    Wu Xiayu; Liang Ziqing; Zou Tianning; Wang Xu

    2009-01-01

    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.

  17. Cellular communication through light.

    Directory of Open Access Journals (Sweden)

    Daniel Fels

    Full Text Available Information transfer is a fundamental of life. A few studies have reported that cells use photons (from an endogenous source as information carriers. This study finds that cells can have an influence on other cells even when separated with a glass barrier, thereby disabling molecule diffusion through the cell-containing medium. As there is still very little known about the potential of photons for intercellular communication this study is designed to test for non-molecule-based triggering of two fundamental properties of life: cell division and energy uptake. The study was performed with a cellular organism, the ciliate Paramecium caudatum. Mutual exposure of cell populations occurred under conditions of darkness and separation with cuvettes (vials allowing photon but not molecule transfer. The cell populations were separated either with glass allowing photon transmission from 340 nm to longer waves, or quartz being transmittable from 150 nm, i.e. from UV-light to longer waves. Even through glass, the cells affected cell division and energy uptake in neighboring cell populations. Depending on the cuvette material and the number of cells involved, these effects were positive or negative. Also, while paired populations with lower growth rates grew uncorrelated, growth of the better growing populations was correlated. As there were significant differences when separating the populations with glass or quartz, it is suggested that the cell populations use two (or more frequencies for cellular information transfer, which influences at least energy uptake, cell division rate and growth correlation. Altogether the study strongly supports a cellular communication system, which is different from a molecule-receptor-based system and hints that photon-triggering is a fine tuning principle in cell chemistry.

  18. Cellular injury evidenced by impedance technology and infrared microspectroscopy

    Science.gov (United States)

    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

  19. Engineering Cellular Metabolism

    DEFF Research Database (Denmark)

    Nielsen, Jens; Keasling, Jay

    2016-01-01

    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...... 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....

  20. Cellular mechanics and motility

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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. Copyright © 2016 Elsevier Inc. All rights reserved.

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

    International Nuclear Information System (INIS)

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

    2016-01-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Shengyong; Chen, Xinhua; Xie, Haiyang; Zhou, Lin [Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, 310003 Hangzhou (China); Key Laboratory of Combined Multi-organ Transplantation, Ministry of Public Health and Key Laboratory of Organ Transplantation of Zhejiang Province, The Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University, Hangzhou 310003 (China); Guo, Danjing; Xu, Yuning [Key Laboratory of Combined Multi-organ Transplantation, Ministry of Public Health and Key Laboratory of Organ Transplantation of Zhejiang Province, The Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University, Hangzhou 310003 (China); Wu, Liming, E-mail: wlm@zju.edu.cn [Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, 310003 Hangzhou (China); Key Laboratory of Combined Multi-organ Transplantation, Ministry of Public Health and Key Laboratory of Organ Transplantation of Zhejiang Province, The Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University, Hangzhou 310003 (China); Zheng, Shusen, E-mail: shusenzheng@zju.edu.cn [Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, 310003 Hangzhou (China); Key Laboratory of Combined Multi-organ Transplantation, Ministry of Public Health and Key Laboratory of Organ Transplantation of Zhejiang Province, The Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University, Hangzhou 310003 (China)

    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.

  4. Trypanocide, cytotoxic, and antifungal activities of Momordica charantia.

    Science.gov (United States)

    Santos, Karla K A; Matias, Edinardo F F; Sobral-Souza, Celestina E; Tintino, Saulo R; Morais-Braga, Maria F B; Guedes, Glaucia M M; Santos, Francisco A V; Sousa, Ana Carla A; Rolón, Miriam; Vega, Celeste; de Arias, Antonieta Rojas; Costa, José G M; Menezes, Irwin R A; Coutinho, Henrique D M

    2012-02-01

    Chagas disease, caused by Trypanosoma cruzi, is a public health problem. Currently, chemotherapy is the only available treatment for this disease, and the drugs used, nifurtimox and benzonidazol, present high toxicity levels. An alternative for replacing these drugs are natural extracts from Momordica charantia L. (Cucurbitaceae) used in traditional medicine because of their antimicrobial and biological activities. In this study, we evaluated the extract of M. charantia for its antiepimastigote, antifungal, and cytotoxic activities. An ethanol extract of leaves from M. charantia was prepared. To research in vitro antiepimastigote activity, T. cruzi CL-B5 clone was used. Epimastigotes were inoculated at a concentration of 1 × 10(5) cells/mL in 200 µl tryptose-liver infusion. For the cytotoxicity assay, J774 macrophages were used. The antifungal activity was evaluated by microdilution using strains of Candida albicans, Candida tropicalis, and Candida krusei. The effective concentration capable of killing 50% of parasites (IC(50)) was 46.06 µg/mL. The minimum inhibitory concentration (MIC) was ≤ 1024 µg/mL. Metronidazole showed a potentiation of its antifungal effect when combined with an extract of M. charantia. Our results indicate that M. charantia could be a source of plant-derived natural products with antiepimastigote and antifungal-modifying activity with moderate toxicity.

  5. The role of autophagy inhibition in the enhanced cytotoxicity of temozolomide on melanoma cell lines

    Directory of Open Access Journals (Sweden)

    O. O. Ryabaya

    2017-01-01

    Full Text Available Background. Despite advantages in treatment of metastatic melanoma it remains resistant to current therapy. Recent evidence indicates that tumor cells could overcome death through autophagy, a process that degrades cellular proteins and organelles to maintain cellular biosynthesis during nutrient deprivation or lack of energy. Objective: to investigate the involvement of autophagy inhibitors chloroquine (CQ and LY-294.002 (LY in temozolomide (TMZ cytotoxicity in human melanoma cell lines.Materials and methods. The study was performed on patient-derived melanoma cell lines Mel Z, Mel IL and Mel MTP. The antiproliferative activity of combined TMZ and autophagy inhibitors treatment was determined by MTT assay and colony-forming assay. Cell cycle analysis, apoptosis activation and expression analysis of key autophagy markers under combined treatment was evaluated.Results. CQ and LY enhanced the cytotoxicity of TMZ and reduced colony formation in 3 melanoma cell lines, moreover both inhibitors increased cell population in G0 / G1 phase of cell cycle in Mel Z, Mel IL cell lines, but not in Mel MTP. CQ and LY synergistically activated apoptosis in all cell lines. The matrix RNA expression analysis of key autophagy genes showed autophagy involvement in enhanced cytotoxicity.Conclusions. Thus, autophagy inhibition on different stages of this process could overcome resistance to TMZ and be applicable as potent target in metastatic melanoma treatment.

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

    Science.gov (United States)

    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. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Gold(III) bis(thiosemicarbazonate) compounds in breast cancer cells: Cytotoxicity and thioredoxin reductase targeting.

    Science.gov (United States)

    Rodríguez-Fanjul, Vanessa; López-Torres, Elena; Mendiola, M Antonia; Pizarro, Ana María

    2018-03-25

    Gold(III) compounds have received increasing attention in cancer research. Three gold complexes of general formula [Au III L]Cl, where L is benzil bis(thiosemicarbazonate), compound 1, benzil bis(4-methyl-3-thiosemicarbazonate), compound 2, or benzil bis(4-cyclohexyl-3-thiosemicarbazonate), compound 3, have been synthesized and fully characterized, including the X-ray crystal structure of compound 3, confirming square-planar geometry around the gold(III) centre. Compound 1 showed moderate cytotoxicity and accumulation in MCF7 breast cancer cells but did not inhibit thioredoxin reductase (TrxR) activity and did not induce reactive oxygen species (ROS) production. Compound 2, the least cytotoxic, was found to be capable of modestly inhibiting TrxR activity and produced low levels of ROS in the MCF7 cell line. The most cytotoxic compound, 3, had the highest cellular accumulation and its distribution pattern showed a clear preference for the cytosol and mitochondria of MCF7 cells. It readily hampered intracellular TrxR activity leading to a dramatic alteration of the cellular redox state and to the induction of cell death. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  8. Cellular-based sea level gauge

    Digital Repository Service at National Institute of Oceanography (India)

    Desai, R.G.P.; Joseph, A.

    treaties with greater transparency. Among the various communication technologies used for real-time transmission of sea-level data are the wired telephone connection, VHF/UHF transceivers, satellite transmit terminals and cellular connectivity. Wired... telephone connections are severely susceptible to loss of connectivity during natural disasters such as storm surges, primarily because of telephone line breakage. Communication via VHF/UHF transceivers is limited by line-of-sight distance between...

  9. Hypoxic cytotoxicity of chlorpromazine and the modification of radiation response in E. coli B/r

    International Nuclear Information System (INIS)

    Shenoy, M.A.; Singh, B.B.

    1978-01-01

    Chlorpromazine (0.1 mM) was cytotoxic to E. coli B/r cells under hypoxic but not euoxic conditions. Under nitrogen bubbling, there was no further enhancement in cellular lethality beyond 45 min contact time. The presence of the free drug seemed necessary for the cytocidal action to be demonstrated. Hypoxic cytotoxicity increased steadily with temperature between 30 and 37 0 C. Treatment of cells with N-ethyl maleimide (0.5 mM) completely abolished the subsequent hypoxic cytotoxicity of chlorpromazine (0.1 mM). Hypoxic gamma irradiation of cells pretreated for 45 min with chlorpromazine under nitrogen bubbling gave a DMF for survival of almost twice that produced by oxygen. Irradiation under aerobic conditions of cells subjected to the same pretreatment produced only the normal oxygen effect. The results indicate that the differential cytotoxicity of chlorpromazine is due to its effect on the changes induced in the membrane-associated biochemical state of the cells under euoxic and hypoxic conditions. (U.K.)

  10. Comparison of Cytotoxic Activity in Leukemic Lineages Reveals Important Features of β-Hairpin Antimicrobial Peptides.

    Science.gov (United States)

    Buri, Marcus V; Torquato, Heron F Vieira; Barros, Carlos Castilho; Ide, Jaime S; Miranda, Antonio; Paredes-Gamero, Edgar J

    2017-07-01

    Several reports described different modes of cell death triggered by antimicrobial peptides (AMPs) due to direct effects on membrane disruption, and more recently by apoptosis and necrosis-like patterns. Cytotoxic curves of four β-hairpin AMPs (gomesin, protegrin, tachyplesin, and polyphemusin) were obtained from several human leukemic lineages and normal monocytes and Two cell lines were then selected based on their cytotoxic sensitivity. One was sensitive to AMPs (K562) and the other resistant (KG-1) and their effect compared between these lineages. Thus, these lineages were chosen to further investigate biological features related with their cytotoxicities to AMPs. Stimulation with AMPs produced cell death, with activation of caspase-3, in K562 lineage. Increase on the fluidity of plasmatic membrane by reducing cholesterol potentiated cytotoxicity of AMPs in both lineages. Quantification of internal and external gomesin binding to the cellular membrane of both K562 and KG-1 cells showed that more peptide is accumulated inside of K562 cells. Additionally, evaluation of multi-drug resistant pumps activity showed that KG-1 has more activity than K562 lineage. A comparison of intrinsic gene patterns showed great differences between K562 and KG-1, but stimulation with gomesin promoted few changes in gene expression patterns. Differences in internalization process through the plasma membrane, multidrug resistance pumps activity, and gene expression pattern are important features to AMPs regulated cell death. J. Cell. Biochem. 118: 1764-1773, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  11. Biochemical studies of immune RNA using a cell-mediated cytotoxicity assay

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, G.D.; Sellin, H.G.; Novelli, G.D.

    1980-01-01

    Immune RNA (iRNA), a subcellular macromolecular species usually prepared by phenol extraction of lymphoid tissue, can confer some manifestation(s) of cellular immunity on naive lymphocytes. Experiments were done to develop an assay system to detect activation of lymphocytes by iRNA to become cytotoxic toward tumor cells, and to study certain properties of iRNA using this system. Guinea pigs were immunized with human mammary carcinoma cells and the iRNA, prepared from spleens of animals shown by prior assay to have blood lymphocytes highly cytotoxic against the tumor cells, was assayed by ability of iRNA-activated lymphocytes to lyse /sup 51/Cr-labelled tumor cells. The ability of iRNA to activate lymphocytes to tumor cytotoxicity could only be differentiated from a cytotoxic activation by RNA preparations from unimmunized animals at very low doses of RNA. The most active iRNA preparations were from cytoplasmic subcellular fractions, extracted by a cold phenol procedure, while iRNA isolated by hot phenol methods was no more active than control RNA prepared by the same techniques. Attempts to demonstrate poly(A) sequences in iRNA were inconclusive.

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

    International Nuclear Information System (INIS)

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

    2011-01-01

    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.

  13. Cytotoxic and phenotypic effects of uranium and lead on osteoblastic cellular models

    International Nuclear Information System (INIS)

    Milgram, S.

    2008-04-01

    This study is involved in the evaluation of bio-hazard associated with the use of uranium in nuclear activities and industrial research. The uranium, known in the literature as potentially carcinogenic or toxic for reproduction, can become a public health problem with the views of the various possibilities of human infections (military of the Gulf War, Finnish populations exposed to drinking water contaminated by example). The skeleton represents the organ of long-term storage of uranium and can be a target of its toxicity. Lead sharing this way of fixing in the bone matrix and have the same adverse effects on bone formation. The osteoblasts, cells responsible in bone formation, are specific targets of these two metals. The aim of this study was to evaluate the effects of acute toxicity of speciation controlled uranium and lead on osteoblasts culture. The intracellular accumulation, distribution and speciation were then studied to explain the observed toxicity. A cell death and phenotypic disorder were highlighted. The speciation is seen as crucial in biological effects of these metals. The most toxic species of both metals have been identified. The accumulation or cell distribution could not alone explain the impact of speciation on the toxicity observed. However, a phenomenon of intracellular precipitation of uranium and lead has been stressed and could be involved in a detoxification mechanism. (author)

  14. Synthesis and cellular cytotoxicities of new N-substituted indole-3 ...

    Indian Academy of Sciences (India)

    Administrator

    MS received 21 November 2008; revised 6 February 2009; accepted 10 February 2009. Abstract. A simple .... Yield (%) m.p. (°C). 3a. H. Allyl. 6. 80⋅0. 4. 91. 73–74 b. 3b. H. Benzyl. 6. 79. 4. 95. 105–107 b. 3c ..... Slight degradation in DNA was ...

  15. Ultrastructural studies of time-course and cellular specificity of interleukin-1 mediated islet cytotoxicity

    DEFF Research Database (Denmark)

    Mandrup-Poulsen, T; Egeberg, J; Nerup, J

    1987-01-01

    of incubation and examined by electron microscopy in a blinded fashion. Already after 30 min, accumulation of opaque intracytoplasmic bodies without apparent surrounding membranes, and autophagic vacuoles were seen in about 20% of the beta cells examined in rat islets exposed to interleukin-1. After 16 h...

  16. Pathogen-mimicking vaccine delivery system designed with a bioactive polymer (inulin acetate) for robust humoral and cellular immune responses.

    Science.gov (United States)

    Kumar, Sunny; Kesharwani, Siddharth S; Kuppast, Bhimanna; Bakkari, Mohammed Ali; Tummala, Hemachand

    2017-09-10

    New and improved vaccines are needed against challenging diseases such as malaria, tuberculosis, Ebola, influenza, AIDS, and cancer. The majority of existing vaccine adjuvants lack the ability to significantly stimulate the cellular immune response, which is required to prevent the aforementioned diseases. This study designed a novel particulate based pathogen-mimicking vaccine delivery system (PMVDS) to target antigen-presenting-cells (APCs) such as dendritic cells. The uniqueness of PMVDS is that the polymer used to prepare the delivery system, Inulin Acetate (InAc), activates the innate immune system. InAc was synthesized from the plant polysaccharide, inulin. PMVDS provided improved and persistent antigen delivery to APCs as an efficient vaccine delivery system, and simultaneously, activated Toll-Like Receptor-4 (TLR-4) on APCs to release chemokine's/cytokines as an immune-adjuvant. Through this dual mechanism, PMVDS robustly stimulated both the humoral (>32 times of IgG1 levels vs alum) and the cell-mediated immune responses against the encapsulated antigen (ovalbumin) in mice. More importantly, PMVDS stimulated both cytotoxic T cells and natural killer cells of cell-mediated immunity to provide tumor (B16-ova-Melanoma) protection in around 40% of vaccinated mice and significantly delayed tumor progression in rest of the mice. PMVDS is a unique bio-active vaccine delivery technology with broader applications for vaccines against cancer and several intracellular pathogens, where both humoral and cellular immune responses are desired. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. iNKT cell cytotoxic responses control T-lymphoma growth in vitro and in vivo

    Science.gov (United States)

    Bassiri, Hamid; Das, Rupali; Guan, Peng; Barrett, David M.; Brennan, Patrick J.; Banerjee, Pinaki P.; Wiener, Susan J.; Orange, Jordan S.; Brenner, Michael B.; Grupp, Stephan A.; Nichols, Kim E.

    2013-01-01

    Invariant natural killer T (iNKT) cells comprise a lineage of CD1d-restricted glycolipid-reactive T lymphocytes with important roles in host immunity to cancer. iNKT cells indirectly participate in antitumor responses by inducing dendritic cell maturation and producing cytokines that promote tumor clearance by CD8+ T and NK cells. Although iNKT cells thereby act as potent cellular adjuvants, it is less clear whether they directly control the growth of tumors. To gain insights into the direct contribution of iNKT cells to tumor immune surveillance, we developed in vitro and in vivo systems to selectively examine the antitumor activity of iNKT cells in the absence of other cytolytic effectors. Using the EL4 T-lymphoma cell line as a model, we find that iNKT cells exert robust and specific lysis of tumor cells in vitro in a manner that is differentially-induced by iNKT cell agonists of varying TCR affinities, such as OCH, α-galactosyl ceramide and PBS44. In vitro blockade of CD1d-mediated lipid antigen presentation, disruption of T cell receptor (TCR) signaling, or loss of perforin expression significantly reduce iNKT cell killing. Consistent with these findings, iNKT cell reconstitution of T, B, and NK cell-deficient mice slows EL4 growth in vivo via TCR-CD1d and perforin-dependent mechanisms. Together, these observations establish that iNKT cells are sufficient to control the growth of T-lymphoma in vitro and in vivo. They also suggest that the induction of iNKT cell cytotoxic responses in situ might serve as a more effective strategy to prevent and/or treat CD1d+ cancers, such as T-lymphoma. PMID:24563871

  18. iNKT cell cytotoxic responses control T-lymphoma growth in vitro and in vivo .

    Science.gov (United States)

    Bassiri, Hamid; Das, Rupali; Guan, Peng; Barrett, David M; Brennan, Patrick J; Banerjee, Pinaki P; Wiener, Susan J; Orange, Jordan S; Brenner, Michael B; Grupp, Stephan A; Nichols, Kim E

    2014-01-01

    Invariant natural killer T (iNKT) cells comprise a lineage of CD1d-restricted glycolipid-reactive T lymphocytes with important roles in host immunity to cancer. iNKT cells indirectly participate in antitumor responses by inducing dendritic cell maturation and producing cytokines that promote tumor clearance by CD8+ T and NK cells. Although iNKT cells thereby act as potent cellular adjuvants, it is less clear whether they directly control the growth of tumors. To gain insights into the direct contribution of iNKT cells to tumor immune surveillance, we developed in vitro and in vivo systems to selectively examine the antitumor activity of iNKT cells in the absence of other cytolytic effectors. Using the EL4 T-lymphoma cell line as a model, we found that iNKT cells exert robust and specific lysis of tumor cells in vitro in a manner that is differentially induced by iNKT cell agonists of varying T-cell receptor (TCR) affinities, such as OCH, α-galactosyl ceramide, and PBS44. In vitro blockade of CD1d-mediated lipid antigen presentation, disruption of TCR signaling, or loss of perforin expression significantly reduce iNKT cell killing. Consistent with these findings, iNKT cell reconstitution of T, B, and NK cell–deficient mice slows EL4 growth in vivo via TCR-CD1d and perforin-dependent mechanisms. Together, these observations establish that iNKT cells are sufficient to control the growth of T lymphoma in vitro and in vivo. They also suggest that the induction of iNKT cell cytotoxic responses in situ might serve as a more effective strategy to prevent and/or treat CD1d+ cancers, such as T lymphoma. ©2013 AACR.

  19. IGF-1 promotes the development and cytotoxic activity of human NK cells

    Science.gov (United States)

    Ni, Fang; Sun, Rui; Fu, Binqing; Wang, Fuyan; Guo, Chuang; Tian, Zhigang; Wei, Haiming

    2013-01-01

    Insulin-like growth factor 1 (IGF-1) is a critical regulator of many physiological functions, ranging from longevity to immunity. However, little is known about the role of IGF-1 in natural killer cell development and function. Here, we identify an essential role for IGF-1 in the positive regulation of human natural killer cell development and cytotoxicity. Specifically, we show that human natural killer cells have the ability to produce IGF-1 and that differential endogenous IGF-1 expression leads to disparate cytotoxicity in human primary natural killer cells. Moreover, miR-483-3p is identified as a critical regulator of IGF-1 expression in natural killer cells. Overexpression of miR-483-3p has an effect similar to IGF-1 blockade and decreased natural killer cell cytotoxicity, whereas inhibition of miR-483-3p has the opposite effect, which is reversible with IGF-1 neutralizing antibody. These findings indicate that IGF-1 and miR-483-3p belong to a new class of natural killer cell functional modulators and strengthen the prominent role of IGF-1 in innate immunity. PMID:23403580

  20. Familial cancer: depressed NK-cell cytotoxicity in healthy and cancer affected members Câncer familiar: depressão da atividade citotóxica de células natural killer em indivíduos sadios e pacientes com diferentes tipos de câncer

    Directory of Open Access Journals (Sweden)

    Terezinha C.B. Montelli

    2001-03-01

    Full Text Available Depressed natural killer (NK cell activity has been showed in family members of patients with different types of cancer. The present work aimed to evaluate T cell subsets and NK cell cytotoxic activity in 15 members of a family with high incidence of tumors, such as glioblastoma, gastric, pancreas and colon rectal carcinoma, chronic myelocitic leukemia, melanoma and osteoblastoma. As controls, 19 healthy subjects with the age range equivalent were studied. The enumeration of CD3+ lymphocytes and their CD4+ and CD8+ subsets were defined by monoclonal antibodies and NK cell cytotoxicity towards K562 target cells were evaluated by single cell-assay. The results showed in family members low percentage of total T cells (CD3+, and their CD4+ subset and impairment of CD4/CD8 ratio in relation to control group. All family members presented percentage of NK-target cell conjugate formation bellow the minimum value observed in control group. Thirteen people were examined and followed up during five years, in order to assure that there was no undiagnosed or unsuspected disease at the moment of evaluation. One of them developed osteoblastoma and other malignant melanoma. Two cancer patients, with glioblastoma and chronic myelocytic leukemia were studied during illness. All the corresponding values were comparable. The persistence of low percentage of conjugate formation may be related to a defect on adhesion molecules expression in the surface of NK cells that was probably responsible for the low activity of these cells presented by the family group. Thus, the inheritance mechanism of low adherence of NK cells should have a prognostic value in determining the risk of developing tumors.Este estudo se reporta às funções de células natural killer (NK, como adesão, lise e citotoxicidade e de subpopulações de células T em uma família com alta prevalência de pacientes com câncer e que apresentaram: glioblastoma, leucemia mielóide cr

  1. Manzamine alkaloids: isolation, cytotoxicity, antimalarial activity and SAR studies.

    Science.gov (United States)

    Ashok, Penta; Ganguly, Swastika; Murugesan, Sankaranarayanan

    2014-11-01

    The infectious disease Malaria is caused by different species of the genus Plasmodium. Resistance to quinoline antimalarial drugs and decreased susceptibility to artemisinin-based combination therapy have increased the need for novel antimalarial agents. Historically, natural products have been used for the treatment of infectious diseases. Identification of natural products and their semi-synthetic derivatives with potent antimalarial activity is an important method for developing novel antimalarial agents. Manzamine alkaloids are a unique group of β-carboline alkaloids isolated from various species of marine sponge displaying potent antimalarial activity against drug-sensitive and -resistant strains of Plasmodium. In this review, we demonstrate antimalarial potency, cytotoxicity and antimalarial SAR of manzamine alkaloids. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Synthesis of geranylhydroquinone derivatives with potential cytotoxic activity

    Energy Technology Data Exchange (ETDEWEB)

    Baeza, Evelyn; Catalan, Karen; Pena-Cortes, Hugo; Espinoza, Luis, E-mail: luis.espinozac@usm.cl [Departamento de Quimica, Universidad Tecnica Federico Santa Maria, Valparaiso (Chile); Villena, Joan [Facultad de Medicina, Universidad de Valparaiso, Centro Regional de Estudios en Alimentos Saludables, Valparaiso (Chile); Carrasco, Hector [Departamento de Ciencias Quimicas, Universidad Andres Bello, Campus Vina del Mar (Chile)

    2012-07-01

    Natural geranylhydroquinone 1 and geranyl-p-methoxyphenol 2 were prepared by Electrophilic Aromatic Substitution (EAS) reactions between geraniol and 1,4-hydroquinone or p-methoxyphenol respectively, using BF{sub 3} {center_dot}Et{sub 2}O as a catalyst. Furthermore, natural geranylquinone 3, geranyl-1,4-dimethoxyquinone 4 and the new geranyl-4-methoxyphenyl acetate 5 were obtained by chemical transformations of 1 and 2. The compounds were evaluated for their in vitro cytotoxicity activities against cultured human cancer cells of PC-3 human prostate cancer, MCF-7 and MDA-MB-231 breast carcinoma, and Dermal Human ibroblasts DHF. IC{sub 50} values were in the {mu}M range. (author)

  3. Cytotoxic and Apoptotic Effect of Structurally Similar Flavonoids on Parental and Drug-Resistant Cells of a Human Cervical Carcinoma

    Directory of Open Access Journals (Sweden)

    Ksenija Durgo

    2009-01-01

    Full Text Available Flavonoids are phytochemicals characterized by a wide range of biological activities, including antioxidant activity, the ability to modulate enzyme or cell receptor activity patterns, and to interfere with essential biochemical pathways. Using HeLa cells of a human cervical carcinoma, and their drug-resistant HeLa CK subline, the effects of three structurally related flavonoids (quercetin, fisetin and luteolin have been examined, in terms of their: (i cytotoxicity, (ii influence on intracellular glutathione (GSH level, (iii influence on glutathione S-transferase (GST activity, and (iv influence on the expression of apoptosis-related genes (PARP, Bcl-2, survivin. Fisetin was more toxic to resistant HeLa CK cell line than to parental cell line, causing decreased expression of survivin in the same cell line. Concentrations of 5 μM of the examined flavonoids caused PARP degradation in parental cell line, leading HeLa cell line into apoptotic cell death. The same event was not determined in the resistant cell line. Fisetin and luteolin induce glutathione and GST in the resistant cell line, pointing to complex cellular effects which could be responsible for higher sensitivity of the resistant cell line in comparison with the parental cell line. Prooxidative nature of the investigated flavonoids was not detected, so free radical formation is not responsible for the induction of GSH, GST and proapoptotic enzymes.

  4. Discovery of a natural product-like iNOS inhibitor by molecular docking with potential neuroprotective effects in vivo.

    Directory of Open Access Journals (Sweden)

    Hai-Jing Zhong

    Full Text Available In this study, we applied structure-based virtual screening techniques to identify natural product or natural product-like inhibitors of iNOS. The iNOS inhibitory activity of the hit compounds was characterized using cellular assays and an in vivo zebrafish larvae model. The natural product-like compound 1 inhibited NO production in LPS-stimulated Raw264.7 macrophages, without exerting cytotoxic effects on the cells. Significantly, compound 1 was able to reverse MPTP-induced locomotion deficiency and neurotoxicity in an in vivo zebrafish larval model. Hence, compound 1 could be considered as a scaffold for the further development of iNOS inhibitors for potential anti-inflammatory or anti-neurodegenerative applications.

  5. Cellular image classification

    CERN Document Server

    Xu, Xiang; Lin, Feng

    2017-01-01

    This book introduces new techniques for cellular image feature extraction, pattern recognition and classification. The authors use the antinuclear antibodies (ANAs) in patient serum as the subjects and the Indirect Immunofluorescence (IIF) technique as the imaging protocol to illustrate the applications of the described methods. Throughout the book, the authors provide evaluations for the proposed methods on two publicly available human epithelial (HEp-2) cell datasets: ICPR2012 dataset from the ICPR'12 HEp-2 cell classification contest and ICIP2013 training dataset from the ICIP'13 Competition on cells classification by fluorescent image analysis. First, the reading of imaging results is significantly influenced by one’s qualification and reading systems, causing high intra- and inter-laboratory variance. The authors present a low-order LP21 fiber mode for optical single cell manipulation and imaging staining patterns of HEp-2 cells. A focused four-lobed mode distribution is stable and effective in optical...

  6. Modeling and cellular studies

    International Nuclear Information System (INIS)

    Anon.

    1982-01-01

    Testing the applicability of mathematical models with carefully designed experiments is a powerful tool in the investigations of the effects of ionizing radiation on cells. The modeling and cellular studies complement each other, for modeling provides guidance for designing critical experiments which must provide definitive results, while the experiments themselves provide new input to the model. Based on previous experimental results the model for the accumulation of damage in Chlamydomonas reinhardi has been extended to include various multiple two-event combinations. Split dose survival experiments have shown that models tested to date predict most but not all the observed behavior. Stationary-phase mammalian cells, required for tests of other aspects of the model, have been shown to be at different points in the cell cycle depending on how they were forced to stop proliferating. These cultures also demonstrate different capacities for repair of sublethal radiation damage

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

    KAUST Repository

    Luxenhofer, Robert

    2011-07-01

    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.

  8. Do Dental X-Rays Induce Genotoxicity and Cytotoxicity in Oral Mucosa Cells? A Critical Review.

    Science.gov (United States)

    Angelieri, Fernanda; Yujra, Veronica Quispe; Oshima, Celina Tizuko Fujiyama; Ribeiro, Daniel Araki

    2017-10-01

    Dental X-rays are widely used in clinical practice, since the technique is an important approach for diagnosing diseases in dental and periodontal tissues. However, it is widely known that radiation is capable of causing damage to cellular systems, such as genotoxicity or cytotoxicity. Thus, the aim of this review was to present a critical analysis regarding the studies published on genotoxicity and cytotoxicity induced by dental X-rays in oral mucosa cells. Such studies have revealed that some oral cell types are more sensitive than others following exposure to dental X-rays. Certainly, this review will contribute to a better understanding of this matter as well as to highlighting perspectives for further studies. Ultimately, such data will promote better safety for both patients and dental professionals. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  9. The enhanced cytotoxicity of misonidazole in the thiol depleted state - An oxygen dependent mechanism

    International Nuclear Information System (INIS)

    Tuttle, S.W.; Varnes, M.E.; Donahue, L.; Biaglow, J.E.

    1985-01-01

    Incubating A549 cells in the presence of L-buthionine-S, R-sulfoximine and misonidazole under aerobic conditions results in lowered rates of cell growth and greater cytotoxicity than is seen with either drug alone. The authors previously demonstrated the accumulation of hydrogen peroxide from cells treated with misonidazole following the inhibition of GSH-peroxidase with thiol depleting agents. They hypothesize that the enhancement of misonidazole toxicity by L-BSO results from the increased exposure to hydrogen peroxide, and the possible formation of the highly reactive hydroxyl radical in the presence of trace metals via Fenton chemistry. Support for this hypothesis comes from their observations that addition of radical scavengers (such as SOD and catalase) and nutritional antioxidants (vitamin E) to the culture medium will partially inhibit the cytotoxic effects. Further work is being done to measure the products of reaction of toxic oxygen species with cellular macromolecules, i.e. lipids

  10. Detection of tumor-specific cytotoxic drug activity in vitro using the fluorometric microculture cytotoxicity assay and primary cultures of tumor cells from patients.

    Science.gov (United States)

    Nygren, P; Fridborg, H; Csoka, K; Sundström, C; de la Torre, M; Kristensen, J; Bergh, J; Hagberg, H; Glimelius, B; Rastad, J

    1994-03-01

    The semi-automated fluorometric microculture cytotoxicity assay (FMCA), based on the measurement of fluorescence generated from cellular hydrolysis of fluorescein diacetate (FDA) by viable cells, was employed for cytotoxic drug sensitivity testing of tumor cells from patients with hematological or solid tumors. In total, 390 samples from 20 diagnoses were tested with up to 12 standard cytotoxic drugs. The technical success rate for different tumor types ranged from 67 to 95%. Fluorescence was linearly related to cell number but variably steep depending on tumor type. Samples from most solid tumors thus showed higher signal-to-noise ratios than hematological samples. A wide spectrum of in vitro drug activity was obtained, with acute leukemias and non-Hodgkin's lymphomas being sensitive to almost all tested drugs, whereas renal and adrenocortical carcinomas were essentially totally resistant. Between these extremes were samples of breast and ovarian carcinomas and sarcomas. When in vitro response was compared with known clinical response patterns, a good correspondence was observed. The results indicate that the FMCA is a rapid and efficient method for in vitro measurement of tumor-specific drug activity both in hematological and in solid tumors. The assay may be suitable for new drug development and direction of phase-2 trials to suitable patients.

  11. Antiadhesive and cytotoxic effect of Iranian Vipera lebetina snake venom on lung epithelial cancer cells.

    Science.gov (United States)

    Oghalaie, Akbar; Kazemi-Lomedasht, Fatemeh; Zareinejad, Mohammad Reza; Shahbazzadeh, Delavar

    2017-01-01

    Cancer is one of the major health problems worldwide. Hence, finding potent therapeutics from natural sources seems necessary. Snake venom of Vipera lebetina contains potential component with anticancer activities such as antiproliferation, migration, invasion, adhesion, and angiogenesis effect. Evaluation of cytotoxic and antiadhesive effect of V. lebetina venom on lung epithelial cancer tumor cell (TC-1) was the main aim of this study. Here, we purified snake venom of V. lebetina by fast protein liquid chromatography (FPLC) using Sephacryl S-200 hr column. The fractions collected and evaluated by SDS-PAGE analysis. The cytotoxicity and antiadhesive effect of crude venom and fractions on TC-1 cells were demonstrated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and adhesion assay, respectively. Our results showed six fractions in FPLC diagram. V. lebetina crude venom and fractions showed dose-dependent cytotoxic effect on TC-1 cells. Fractions 2 and 5 showed high cytotoxic effect with high IC50 value (IC50 = 6 μg/ml for fraction 2 and IC50 = 7.3 μg/ml for fraction 5). Fractions 2 and 5 selected for analysis antiadhesive effect on TC-1 cells. Furthermore, our results showed that both fractions 2 and 5 had antiadhesive effect on TC-1 cells. Because of potent cytotoxic and antiadhesive effect of V. lebetina fractions on lung epithelial cancer cell line, it could be promising tools for further analysis as anticancer therapeutic development.

  12. Antiadhesive and cytotoxic effect of Iranian Vipera lebetina snake venom on lung epithelial cancer cells

    Directory of Open Access Journals (Sweden)

    Akbar Oghalaie

    2017-01-01

    Full Text Available Background: Cancer is one of the major health problems worldwide. Hence, finding potent therapeutics from natural sources seems necessary. Snake venom of Vipera lebetina contains potential component with anticancer activities such as antiproliferation, migration, invasion, adhesion, and angiogenesis effect. Evaluation of cytotoxic and antiadhesive effect of V. lebetina venom on lung epithelial cancer tumor cell (TC-1 was the main aim of this study. Materials and Methods: Here, we purified snake venom of V. lebetina by fast protein liquid chromatography (FPLC using Sephacryl S-200 hr column. The fractions collected and evaluated by SDS-PAGE analysis. The cytotoxicity and antiadhesive effect of crude venom and fractions on TC-1 cells were demonstrated using 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide and adhesion assay, respectively. Results: Our results showed six fractions in FPLC diagram. V. lebetina crude venom and fractions showed dose-dependent cytotoxic effect on TC-1 cells. Fractions 2 and 5 showed high cytotoxic effect with high IC50 value (IC50 = 6 μg/ml for fraction 2 and IC50 = 7.3 μg/ml for fraction 5. Fractions 2 and 5 selected for analysis antiadhesive effect on TC-1 cells. Furthermore, our results showed that both fractions 2 and 5 had antiadhesive effect on TC-1 cells. Conclusion: Because of potent cytotoxic and antiadhesive effect of V. lebetina fractions on lung epithelial cancer cell line, it could be promising tools for further analysis as anticancer therapeutic development.

  13. Cytotoxicity effect of Zataria multiflora Boiss. on two human colon carcinoma cell lines

    Directory of Open Access Journals (Sweden)

    F. Sharififar

    2017-10-01

    Full Text Available Background and objectives: Natural products are one of the major sources for investigations of novel medicines. Zataria multiflora Boiss (ZM has shown pharmacological activities especially in gastrointestinal tract; however, there are limited studies about its cytotoxicity effects. In this study, the effect of Zataria multiflora was examined on two colon cancer cell lines (SW-48 and HT-29. Methods: Hydro-alcoholic extract of ZM and its fractions including chloroform, petroleum ether and methanol extract were prepared by warm maceration method. Different concentrations were prepared and examined on SW-48 and HT-29 cell lines using 2-(4, 5-dimethylthiazol-2-yl 2, 5-diphenyltetrazolium bromide (MTT assay. Results: The results of the present study have shown the cytotoxic effect of some fractions of ZM. The most considerable cytotoxic effect was shown against HT-29 cell line. Also, total ZM extract and the petroleum ether fraction demonstrated cytotoxic effects with IC50 values of 44.22 and 33.42 µg/ml on SW-48 and HT-29 cell lines, respectively. Conclusion: Zataria multiflora was cytotoxic to against colon cancer cell lines HT-29 and SW-48.

  14. Statistical mechanics of cellular automata

    International Nuclear Information System (INIS)

    Wolfram, S.

    1983-01-01

    Cellular automata are used as simple mathematical models to investigate self-organization in statistical mechanics. A detailed analysis is given of ''elementary'' cellular automata consisting of a sequence of sites with values 0 or 1 on a line, with each site evolving deterministically in discrete time steps according to p definite rules involving the values of its nearest neighbors. With simple initial configurations, the cellular automata either tend to homogeneous states, or generate self-similar patterns with fractal dimensions approx. =1.59 or approx. =1.69. With ''random'' initial configurations, the irreversible character of the cellular automaton evolution leads to several self-organization phenomena. Statistical properties of the structures generated are found to lie in two universality classes, independent of the details of the initial state or the cellular automaton rules. More complicated cellular automata are briefly considered, and connections with dynamical systems theory and the formal theory of computation are discussed

  15. Aberrantly glycosylated MUC1 is expressed on the surface of breast cancer cells and a target for antibody-dependent cell-mediated cytotoxicity

    DEFF Research Database (Denmark)

    Lavrsen, Kirstine; Madsen, Caroline B; Rasch, Morten G

    2013-01-01

    to Tn-MUC1 was investigated using BiaCore. The availability of Tn-MUC1 on the surface of breast cancer cells was evaluated by immunohistochemistry, confocal microscopy, and flow cytometry, followed by in vitro assessment of antibody-dependent cellular cytotoxicity by mAb 5E5. Biacore analysis...

  16. Diselenolane-mediated cellular uptake.

    Science.gov (United States)

    Chuard, Nicolas; Poblador-Bahamonde, Amalia I; Zong, Lili; Bartolami, Eline; Hildebrandt, Jana; Weigand, Wolfgang; Sakai, Naomi; Matile, Stefan

    2018-02-21

    The emerging power of thiol-mediated uptake with strained disulfides called for a move from sulfur to selenium. We report that according to results with fluorescent model substrates, cellular uptake with 1,2-diselenolanes exceeds uptake with 1,2-dithiolanes and epidithiodiketopiperazines with regard to efficiency as well as intracellular localization. The diselenide analog of lipoic acid performs best. This 1,2-diselenolane delivers fluorophores efficiently to the cytosol of HeLa Kyoto cells, without detectable endosomal capture as with 1,2-dithiolanes or dominant escape into the nucleus as with epidithiodiketopiperazines. Diselenolane-mediated cytosolic delivery is non-toxic (MTT assay), sensitive to temperature but insensitive to inhibitors of endocytosis (chlorpromazine, methyl-β-cyclodextrin, wortmannin, cytochalasin B) and conventional thiol-mediated uptake (Ellman's reagent), and to serum. Selenophilicity, the extreme CSeSeC dihedral angle of 0° and the high but different acidity of primary and secondary selenols might all contribute to uptake. Thiol-exchange affinity chromatography is introduced as operational mimic of thiol-mediated uptake that provides, in combination with rate enhancement of DTT oxidation, direct experimental evidence for existence and nature of the involved selenosulfides.

  17. Quantum Dots Encapsulated with Canine Parvovirus-Like Particles Improving the Cellular Targeted Labeling.

    Directory of Open Access Journals (Sweden)

    Dan Yan

    Full Text Available Quantum dots (QDs have a promising prospect in live-cell imaging and sensing because of unique fluorescence features. QDs aroused significant interest in the bio-imaging field through integrating the fluorescence properties of QDs and the delivery function of biomaterial. The natural tropism of Canine Parvovirus (CPV to the transferrin receptor can target specific cells to increase the targeting ability of QDs in cell imaging. CPV virus-like particles (VLPs from the expression of the CPV-VP2 capsid protein in a prokaryotic expression system were examined to encapsulate the QDs and deliver to cells with an expressed transferrin receptor. CPV-VLPs were used to encapsulate QDs that were modified using 3-mercaptopropionic acid. Gel electrophoresis, fluorescence spectrum, particle size, and transmission electron microscopy verified the conformation of a complex, in which QDs were encapsulated in CPV-VLPs (CPV-VLPs-QDs. When incubated with different cell lines, CPV-VLPs-QDs significantly reduced the cytotoxicity of QDs and selectively labeled the cells with high-level transferrin receptors. Cell-targeted labeling was achieved by utilizing the specific binding between the CPV capsid protein VP2 of VLPs and cellular receptors. CPV-VLPs-QDs, which can mimic the native CPV infection, can recognize and attach to the transferrin receptors on cellular membrane. Therefore, CPV-VLPs can be used as carriers to facilitate the targeted delivery of encapsulated nanomaterials into cells via receptor-mediated pathways. This study confirmed that CPV-VLPs can significantly promote the biocompatibility of nanomaterials and could expand the application of CPV-VLPs in biological medicine.

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

    Directory of Open Access Journals (Sweden)

    Camille C. Hanot

    2015-12-01

    Full Text Available 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.

  19. GoldiRunx and Remembering Cytotoxic Memory.

    Science.gov (United States)

    Mikami, Yohei; Kanno, Yuka

    2018-04-17

    The molecular basis for T cell memory differentiation remains elusive. Wang et al. (2018) identify Runx3 as an initiating transcription factor that specifies regulatory regions required for cytotoxic T cell (CTL) memory differentiation early after TCR signaling and constrains the ability of T-bet to drive terminal effector generation. Published by Elsevier Inc.

  20. SYNTHESIS AND CYTOTOXICITY OF NOVEL LIGNANS

    NARCIS (Netherlands)

    Middel, O; Woerdenbag, H.J.; van Uden, W.; van Oeveren, A.; Jansen, J.F.G.A.; Feringa, B.L.; Konings, A.WT; Pras, N.; Kellogg, R.M

    1995-01-01

    In this study the syntheses of 11 novel lignans are described. Their cytotoxicities are studied in GLC(4), a human small cell lung carcinoma cell line, using the microculture tetrazolium (MTT) assay. Ten of these compounds were substituted with a menthyloxy group on the 5-position of the lactone.

  1. Synthesis and Cytotoxicity of Novel Hexahydrothienocycloheptapyridazinone Derivatives

    Directory of Open Access Journals (Sweden)

    Irene Marchesi

    2009-09-01

    Full Text Available Designed as a new group of tricyclic molecules containing the thienocycloheptapyridazinone ring system, a number of 2N-substituted-hexahydrothienocycloheptapyridazinone derivatives were synthesized and their biological activity evaluated. Among the synthesized compounds, derivatives 7d and 7h were found to possess cytotoxic activity against non-small cell lung cancer and central nervous system cancer cell lines, respectively.

  2. Cytotoxic activity of four Mexican medicinal plants.

    Science.gov (United States)

    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.

  3. Cytotoxic human CD4(+) T cells

    NARCIS (Netherlands)

    van de Berg, Pablo J.; van Leeuwen, Ester M.; ten Berge, Ineke J.; van Lier, Rene

    2008-01-01

    The induction of adaptive immune responses critically depends on helper signals provided by CD4(+) T cells. These signals not only license antigen presenting cells (APC) to activate naïve CD8(+) T cells leading to the formation of vast numbers of cytotoxic T lymphocytes but also support the

  4. Randomized anticancer and cytotoxicity activities of Guibourtia ...

    African Journals Online (AJOL)

    Materials and Methods: The plants were screened for the presence of coumarins, alkaloids, flavonoids, anthraquinones, steroids and terpenoids using thin layer chromatography. Anticancer screening was performed on a panel of three cancer cell lines, while cytotoxicity was determined using a human fibroblast cell line, ...

  5. Cytotoxicity of poly(p-phenylenediamine)

    Czech Academy of Sciences Publication Activity Database

    Kuceková, Z.; Rejmontová, P.; Humpolíček, P.; Kašpárková, V.; Bober, Patrycja; Sáha, P.; Stejskal, Jaroslav

    2017-01-01

    Roč. 71, č. 2 (2017), s. 367-372 ISSN 0366-6352 R&D Projects: GA ČR(CZ) GA13-00270S Institutional support: RVO:61389013 Keywords : cytotoxicity * poly(p-phenylenediamine) * mouse embryonic fibroblasts Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 1.258, year: 2016

  6. Cytotoxicity of Nanoliposomal Cisplatin Coated with Synthesized ...

    African Journals Online (AJOL)

    Purpose: To evaluate the cytotoxicity of pegylated nanoliposomal cisplatin on human ovarian cancer cell line A2780CP. Methods: Synthesized methoxypolyethylene glycol (mPEG) propionaldehyde was characterized by 1Hnuclear magnetic resonance (1H-NMR) and Fourier transform infrared spectroscopy (FTIR) and used ...

  7. The antioxidant properties, cytotoxicity and monoamine oxidase ...

    African Journals Online (AJOL)

    Tarchonanthus camphoratus (camphor bush) has been widely used for numerous medicinal purposes. The aim of the present study was to evaluate the antioxidant properties, cytotoxicity and monoamine oxidase inhibition activities of the crude dichloromethane leaf extract of T. camphoratus. The antioxidant activities were ...

  8. Complex Automata: Multi-scale Modeling with Coupled Cellular Automata

    NARCIS (Netherlands)

    Hoekstra, A.G.; Caiazzo, A.; Lorenz, E.; Falcone, J.-L.; Chopard, B.; Hoekstra, A.G.; Kroc, J.; Sloot, P.M.A.

    2010-01-01

    Cellular Automata (CA) are generally acknowledged to be a powerful way to describe and model natural phenomena [1-3]. There are even tempting claims that nature itself is one big (quantum) information processing system, e.g. [4], and that CA may actually be nature’s way to do this processing [5-7].

  9. Cellular mechanisms in drug - radiation interaction

    International Nuclear Information System (INIS)

    Trott, K.R.

    1979-01-01

    Some cytotoxic drugs, especially those belonging to the group of antibiotics and antimetabolites, sensitize the cells having survived drug treatment to the subsequent irradiation by either increasing the slope of the radiation dose response curves or by decreasing extrapolation number. Bleomycin was found to interact with radiation in L-cells and FM3A cells, but not in HeLa-cells. The data with EMT-6 cells suggest that the interaction depends on drug dose: no interaction occurred after the exposure to bleomycin which killed only 20 - 40% of the cells; yet the exposure to bleomycin which killed 90% of the cells in addition sensitized the surviving cells by the DMF of 1.3. The sensitization found 24 hr after the exposure of HeLa cells to methotrexate was due to cell synchronization. Other cytostatic drugs were found to synchronize proliferating cells even better. Therefore, the fluctuation of radiosensitivity has been commonly observed after the termination of exposure to these drugs. Preirradiation may lead to the change in drug dose response curves. The recruitment of resting cells into cycle occurs hours or days later, in some irradiated normal and malignant tissues. Since many cytostatic drugs are far more active in proliferating cells than in resting cells, the recruitment after irradiation may lead to the sudden increase in drug sensitivity, days after the irradiation. No single, simple theory seems to exist to classify and predict the cellular response to combined modality treatment. (Yamashita, S.)

  10. HBV-specific CD4+ cytotoxic T cells in hepatocellular carcinoma are less cytolytic toward tumor cells and suppress CD8+ T cell-mediated antitumor immunity.

    Science.gov (United States)

    Meng, Fanzhi; Zhen, Shoumei; Song, Bin

    2017-08-01

    In East Asia and sub-Saharan Africa, chronic infection is the main cause of the development of hepatocellular carcinoma, an aggressive cancer with low survival rate. Cytotoxic T cell-based immunotherapy is a promising treatment strategy. Here, we investigated the possibility of using HBV-specific CD4 + cytotoxic T cells to eliminate tumor cells. The naturally occurring HBV-specific cytotoxic CD4 + and CD8 + T cells were identified by HBV peptide pool stimulation. We found that in HBV-induced hepatocellular carcinoma patients, the HBV-specific cytotoxic CD4 + T cells and cytotoxic CD8 + T cells were present at similar numbers. But compared to the CD8 + cytotoxic T cells, the CD4 + cytotoxic T cells secreted less cytolytic factors granzyme A (GzmA) and granzyme B (GzmB), and were less effective at eliminating tumor cells. In addition, despite being able to secrete cytolytic factors, CD4 + T cells suppressed the cytotoxicity mediated by CD8 + T cells, even when CD4 + CD25 + regulator T cells were absent. Interestingly, we found that interleukin 10 (IL-10)-secreting Tr1 cells were enriched in the cytotoxic CD4 + T cells. Neutralization of IL-10 abrogated the suppression of CD8 + T cells by CD4 + CD25 - T cells. Neither the frequency nor the absolute number of HBV-specific CD4 + cytotoxic T cells were correlated with the clinical outcome of advanced stage hepatocellular carcinoma patients. Together, this study demonstrated that in HBV-related hepatocellular carcinoma, CD4 + T cell-mediated cytotoxicity was present naturally in the host and had the potential to exert antitumor immunity, but its capacity was limited and was associated with immunoregulatory properties. © 2017 APMIS. Published by John Wiley & Sons Ltd.

  11. Phenolics, Antiradical Assay and Cytotoxicity of Processed Mango ...

    African Journals Online (AJOL)

    Phenolics, Antiradical Assay and Cytotoxicity of Processed Mango ( Mangifera indica ) and Bush Mango ( Irvingia gabonensis ) Kernels. ... Nigerian Food Journal ... Phenolic constituents (total phenols, flavonoids, tannins, and anthocyanins), comparative antiradical potency and cytotoxicity of processed mango (Mangifera ...

  12. Phytoconstituents with Radical Scavenging and Cytotoxic Activities from Diospyros shimbaensis

    Directory of Open Access Journals (Sweden)

    Per Aronsson

    2016-01-01

    Full Text Available As part of our search for natural products having antioxidant and anticancer properties, the phytochemical investigation of Diospyros shimbaensis (Ebenaceae, a plant belonging to a genus widely used in East African traditional medicine, was carried out. From its stem and root barks the new naphthoquinone 8,8′-oxo-biplumbagin (1 was isolated along with the known tetralones trans-isoshinanolone (2 and cis-isoshinanolone (3, and the naphthoquinones plumbagin (4 and 3,3′-biplumbagin (5. Compounds 2, 4, and 5 showed cytotoxicity (IC50 520–82.1 μM against MDA-MB-231 breast cancer cells. Moderate to low cytotoxicity was observed for the hexane, dichloromethane, and methanol extracts of the root bark (IC50 16.1, 29.7 and > 100 μg/mL, respectively, and for the methanol extract of the stem bark (IC50 59.6 μg/mL. The radical scavenging activity of the isolated constituents (1–5 was evaluated on the 2,2-diphenyl-1-picrylhydrazyl (DPPH radical scavenging assay. The applicability of the crude extracts and of the isolated constituents for controlling degenerative diseases is discussed.

  13. Phytoconstituents with Radical Scavenging and Cytotoxic Activities from Diospyros shimbaensis.

    Science.gov (United States)

    Aronsson, Per; Munissi, Joan J E; Gruhonjic, Amra; Fitzpatrick, Paul A; Landberg, Göran; Nyandoro, Stephen S; Erdelyi, Mate

    2016-01-15

    As part of our search for natural products having antioxidant and anticancer properties, the phytochemical investigation of Diospyros shimbaensis (Ebenaceae), a plant belonging to a genus widely used in East African traditional medicine, was carried out. From its stem and root barks the new naphthoquinone 8,8'-oxo-biplumbagin ( 1 ) was isolated along with the known tetralones trans -isoshinanolone ( 2 ) and cis -isoshinanolone ( 3 ), and the naphthoquinones plumbagin ( 4 ) and 3,3'-biplumbagin ( 5 ). Compounds 2 , 4 , and 5 showed cytotoxicity (IC 50 520-82.1 μM) against MDA-MB-231 breast cancer cells. Moderate to low cytotoxicity was observed for the hexane, dichloromethane, and methanol extracts of the root bark (IC 50 16.1, 29.7 and > 100 μg/mL, respectively), and for the methanol extract of the stem bark (IC 50 59.6 μg/mL). The radical scavenging activity of the isolated constituents ( 1 - 5 ) was evaluated on the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. The applicability of the crude extracts and of the isolated constituents for controlling degenerative diseases is discussed.

  14. Surface-dependent cytotoxicity on bacteria as a model for environmental stress of halloysite nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hyo-Jick, E-mail: hyojickchoi@gmail.com [National Institute for Nanotechnology, Nanotechnology Accelerator and Department of Chemical and Materials Engineering, University of Alberta (Canada); Stazak, Theodore J. [School of Energy, Environmental, Biological and Medical Engineering, University of Cincinnati (United States); Montemagno, Carlo D., E-mail: montemag@ualberta.ca [National Institute for Nanotechnology, Nanotechnology Accelerator and Department of Chemical and Materials Engineering, University of Alberta (Canada)

    2013-10-15

    This study examined the cytotoxicity of halloysite nanotubes (HNTs) by investigating physiological responses of Escherichia coli, from cell growth to protein expression. Surfaces of HNTs were modified by amine functionalization (NH{sub 2}-HNTs) or bovine serum albumin (BSA) coating and their cytotoxicity levels were compared with that of non-modified HNTs (Bare-HNTs). Bare- and NH{sub 2}-HNTs exhibited accelerated cell death rates at {>=}0.5 mg/ml of HNTs. It was also found that concentration as low as 0.01 mg/ml of HNTs exerted significant toxic effects on the bacterial cells. Cellular viability, metabolic activity, and DNA replication all decreased with increasing concentrations of Bare- and NH{sub 2}-HNTs. In contrast, 0.01 mg/ml of BSA-coated HNTs (BSA-HNTs) coated showed no evidence of cytotoxicity. Even at concentrations {<=}0.1 mg/ml, the cytocompatibility of BSA-HNTs was significantly better than those of Bare- and NH{sub 2}-HNTs, which was confirmed by the observation of (i) the same or similar levels of cell proliferation and cell viability to the control, and (ii) higher levels of metabolic activity and plasmid DNA replication than those of Bare- and NH{sub 2}-HNTs. In addition, higher ranaspumin-2 protein yield was observed from bacterial culture supplemented with BSA-HNTs (100, 83, and 80 % of yield at 0.01, 0.05, and 0.1 mg/ml, respectively, relative to the control). This work showed that the increase of bacterial cytotoxicity of HNTs correlated well with elevating HNT concentration and that surface modification of HNTs with amine functional group and BSA coating was an effective strategy to reduce cytotoxicity up to 0.1 mg/ml of HNTs.

  15. A cell impedance measurement device for the cytotoxicity assay dependent on the velocity of supplied toxic fluid

    Science.gov (United States)

    Kang, Yoon-Tae; Kim, Min-Ji; Cho, Young-Ho

    2018-04-01

    We present a cell impedance measurement chip capable of characterizing the toxic response of cells depending on the velocity of the supplied toxic fluid. Previous impedance-based devices using a single open-top chamber have been limited to maintaining a constant supply velocity, and devices with a single closed-top chamber present difficulties in simultaneous cytotoxicity assay for varying levels of supply velocities. The present device, capable of generating constant and multiple levels of toxic fluid velocity simultaneously within a single stepwise microchannel, performs a cytotoxicity assay dependent on toxic fluid velocity, in order to find the effective velocity of toxic fluid to cells for maximizing the cytotoxic effect. We analyze the cellular toxic response of 5% ethanol media supplied to cancer cells within a toxic fluid velocity range of 0-8.3 mm s-1. We observe the velocity-dependent cell detachment rate, impedance, and death rate. We find that the cell detachment rate decreased suddenly to 2.4% at a velocity of 4.4 mm s-1, and that the change rates of cell resistance and cell capacitance showed steep decreases to 8% and 41%, respectively, at a velocity of 5.7 mm s-1. The cell death rate and impedance fell steeply to 32% at a velocity of 5.7 mm s-1. We conclude that: (1) the present device is useful in deciding on the toxic fluid velocity effective to cytotoxicity assay, since the cellular toxic response is dependent on the velocity of toxic fluid, and; (2) the cell impedance analysis facilitates a finer cellular response analysis, showing better correlation with the cell death rate, compared to conventional visual observation. The present device, capable of performing the combinational analysis of toxic fluid velocity and cell impedance, has potential for application to the fine cellular toxicity assay of drugs with proper toxic fluid velocity.

  16. Cell-mediated immunity to Plasmodium falciparum infection: evidence against the involvement of cytotoxic lymphocytes

    DEFF Research Database (Denmark)

    Theander, T G; Andersen, B J; Pedersen, B K

    1988-01-01

    stimulated PBMC from malaria-immune donors by SPag and purified protein derivative (PPD) in culture for 7 days. The PBMC were then co-incubated with P. falciparum for 48 h, and parasitaemia was determined by microscopy. Parasite growth was only significantly impaired after incubation with PBMC stimulated...... by either SPag or PPD in the presence of immune serum. Studies on subpopulations of PBMC indicated that the inhibitory cells resided among the adherent cell fraction. Furthermore we tested PBMC for cytotoxic activity against P. falciparum-infected autologous or heterologous erythrocytes. Experiments were...... done both in the absence and the presence of immune serum. Neither fresh PBMC nor PBMC activated by SPag or PPD for 7 days prior to assay were cytotoxic, indicating that cytotoxic T cells, natural killer (NK) cells, and K cells did not possess cytotoxic activity directed against parasitized...

  17. 47 CFR 22.909 - Cellular markets.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 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 markets...

  18. A cytotoxic serine proteinase isolated from mouse submandibular gland.

    Science.gov (United States)

    Shimamura, T; Nagumo, N; Ikigai, H; Murakami, K; Okubo, S; Toda, M; Ohnishi, R; Tomita, M

    1989-08-01

    We have isolated a novel cytotoxic factor from the submandibular glands of male BALB/c mice by Sephadex G-50 gel filtration chromatography and reverse-phase HPLC. The cytotoxic factor is a serine proteinase, which belongs to the mouse glandular kallikrein (mGK) family, with an Mr of approximately 27,000. The purified serine proteinase showed cytotoxic activity against mouse thymocytes in a dose-dependent manner, and a serine proteinase inhibitor, diisopropyl fluorophosphate, blocked its cytotoxic activity.

  19. Rapid bioreduction of trivalent aurum using banana stem powder and its cytotoxicity against MCF-7 and HEK-293 cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Arunkumar, Pichaimani [Bharathidasan University, Cancer Genetics and Nanomedicine Laboratory, Department of Biomedical Science, School of Basic Medical Sciences (India); Vedagiri, Hemamalini [Bharathidasan University, Department of Biotechnology (India); Premkumar, Kumpati, E-mail: pkumpati@hotmail.com [Bharathidasan University, Cancer Genetics and Nanomedicine Laboratory, Department of Biomedical Science, School of Basic Medical Sciences (India)

    2013-03-15

    Bioreduction of metal ions for the synthesis of nanoparticles of well-defined shape and size has been a great challenge in the field of nanotechnology. In this study, we explored the reduction potential of banana stem powder (BSP) for the synthesis of gold nanoparticles (GNP). The kinetics of GNP synthesis was monitored using UV-Vis spectroscopy. The synthesized GNP was characterized using dynamic light scattering (DLS), transmission electron microscopy, and fourier transform infrared spectroscopy. In addition, the cytotoxic potential of the synthesized GNP was investigated using human breast cancer (MCF-7) and normal human embryonic kidney (HEK-293) cell lines, as evaluated by changes in cell morphology, cell viability (MTT), and metabolic activity. BSP exhibited a strong reduction of Au(III) to Au (0) at room temperature within 5 min of reaction time. The synthesized GNP was found to be spherical with an average diameter of 30 nm by DLS analysis. The cytotoxicity analysis reveals a direct dose-response relationship, indicating that the cytotoxicity increases with increasing concentrations of the GNP. Significant cytotoxicity was observed in cancer cells (MCF-7) compared to normal cells (HEK-293). Also the cellular uptake of GNP was more pronounced in MCF-7 cells than HEK-293 cells as evidenced by zeta potential, implicating the possible reason for differential cytotoxicity. Thus the present study demonstrates the importance of these unique, less time-consuming, and stable BSP-mediated GNP as potential drug delivery vehicles in the application of anticancer therapy.

  20. The cytotoxic effect of oxybuprocaine on human corneal epithelial cells by inducing cell cycle arrest and mitochondria-dependent apoptosis.

    Science.gov (United States)

    Fan, W-Y; Wang, D-P; Wen, Q; Fan, T-J

    2017-08-01

    Oxybuprocaine (OBPC) is a widely used topical anesthetic in eye clinic, and prolonged and repeated usage of OBPC might be cytotoxic to the cornea, especially to the outmost corneal epithelium. In this study, we characterized the cytotoxic effect of OBPC on human corneal epithelial (HCEP) cells and investigated its possible cellular and molecular mechanisms using an in vitro model of non-transfected HCEP cells. Our results showed that OBPC at concentrations ranging from 0.025% to 0.4% had a dose- and time-dependent cytotoxicity to HCEP cells. Moreover, OBPC arrested the cells at S phase and induced apoptosis of these cells by inducing plasma membrane permeability, phosphatidylserine externalization, DNA fragmentation, and apoptotic body formation. Furthermore, OBPC could trigger the activation of caspase-2, -3, and -9, downregulate the expression of Bcl-xL, upregulate the expression of Bax along with the cytoplasmic amount of mitochondria-released apoptosis-inducing factor, and disrupt mitochondrial transmembrane potential. Our results suggest that OBPC has a dose- and time-dependent cytotoxicity to HCEP cells by inducing cell cycle arrest and cell apoptosis via a death receptor-mediated mitochondria-dependent proapoptotic pathway, and this novel finding provides new insights into the acute cytotoxicity and its toxic mechanisms of OBPC on HCEP cells.

  1. Designing beauty the art of cellular automata

    CERN Document Server

    Martínez, Genaro

    2016-01-01

    This fascinating, colourful book offers in-depth insights and first-hand working experiences in the production of art works, using simple computational models with rich morphological behaviour, at the edge of mathematics, computer science, physics and biology. It organically combines ground breaking scientific discoveries in the theory of computation and complex systems with artistic representations of the research results. In this appealing book mathematicians, computer scientists, physicists, and engineers brought together marvelous and esoteric patterns generated by cellular automata, which are arrays of simple machines with complex behavior. Configurations produced by cellular automata uncover mechanics of dynamic patterns formation, their propagation and interaction in natural systems: heart pacemaker, bacterial membrane proteins, chemical rectors, water permeation in soil, compressed gas, cell division, population dynamics, reaction-diffusion media and self-organisation. The book inspires artists to tak...

  2. Cytotoxic effect of betulinic acid and betulinic acid acetate isolated ...

    African Journals Online (AJOL)

    Cytotoxic effect of betulinic acid and betulinic acid acetate isolated from Melaleuca cajuput on human myeloid leukemia (HL-60) cell line. ... The cytotoxic effect of betulinic acid (BA), isolated from Melaleuca cajuput a Malaysian plant and its four synthetic derivatives were tested for their cytotoxicity in various cell line or ...

  3. Elastomeric Cellular Structure Enhanced by Compressible Liquid Filler

    Science.gov (United States)

    Sun, Yueting; Xu, Xiaoqing; Xu, Chengliang; Qiao, Yu; Li, Yibing

    2016-05-01

    Elastomeric cellular structures provide a promising solution for energy absorption. Their flexible and resilient nature is particularly relevant to protection of human bodies. Herein we develop an elastomeric cellular structure filled with nanoporous material functionalized (NMF) liquid. Due to the nanoscale infiltration in NMF liquid and its interaction with cell walls, the cellular structure has a much enhanced mechanical performance, in terms of loading capacity and energy absorption density. Moreover, it is validated that the structure is highly compressible and self-restoring. Its hyper-viscoelastic characteristics are elucidated.

  4. In Vitro antibacterial and in Vivo cytotoxic activities of Grewia paniculata

    Directory of Open Access Journals (Sweden)

    Mahmuda Nasrin

    2015-02-01

    Full Text Available Objectives: Grewia paniculata (Family: Malvaceae has been used to treat inflammation, respiratory disorders and fever. It is additionally employed for other health conditions including colds, diarrhea and as an insecticide in Bangladesh. The aim of the present study was to investigate the antibacterial and cytotoxic activities of different extracts of Grewia paniculata. Materials and Methods: The antibacterial activity was evaluated against both gram negative and gram positive bacteria using disc diffusion method by determination of the diameter of zone of inhibition. Cytotoxic activity was performed by brine shrimp (Artemia salina lethality bioassay. Results: In disc diffusion method, all the natural products (400 μg/disc showed moderate to potent activity against all the tested bacteria. The ethanol extract of bark (EEB and ethanol fraction of bark (EFB (400 μg/disc exhibited highest activity against Shigella dysenteriae with a zone of inhibition of 23±1.63 mm and  23±1.77 mm respectively. In the brine shrimp lethality bioassay all the extracts showed moderate cytotoxic activity when compared with the standard drug vincristin sulphate. For example, LC50 value of the ethanol fraction of bark (EFB was 3.01 μg/ml while the LC50 of vincristine sulphate was 0.52 μg/ml. Conclusions: The results suggest that all the natural products possess potent antibacterial and moderate cytotoxic.

  5. MSAT and cellular hybrid networking

    Science.gov (United States)

    Baranowsky, Patrick W., II

    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.

  6. Cellular automata analysis and applications

    CERN Document Server

    Hadeler, Karl-Peter

    2017-01-01

    This book focuses on a coherent representation of the main approaches to analyze the dynamics of cellular automata. Cellular automata are an inevitable tool in mathematical modeling. In contrast to classical modeling approaches as partial differential equations, cellular automata are straightforward to simulate but hard to analyze. In this book we present a review of approaches and theories that allow the reader to understand the behavior of cellular automata beyond simulations. The first part consists of an introduction of cellular automata on Cayley graphs, and their characterization via the fundamental Cutis-Hedlund-Lyndon theorems in the context of different topological concepts (Cantor, Besicovitch and Weyl topology). The second part focuses on classification results: What classification follows from topological concepts (Hurley classification), Lyapunov stability (Gilman classification), and the theory of formal languages and grammars (Kůrka classification). These classifications suggest to cluster cel...

  7. MIMO Communication for Cellular Networks

    CERN Document Server

    Huang, Howard; Venkatesan, Sivarama

    2012-01-01

    As the theoretical foundations of multiple-antenna techniques evolve and as these multiple-input multiple-output (MIMO) techniques become essential for providing high data rates in wireless systems, there is a growing need to understand the performance limits of MIMO in practical networks. To address this need, MIMO Communication for Cellular Networks presents a systematic description of MIMO technology classes and a framework for MIMO system design that takes into account the essential physical-layer features of practical cellular networks. In contrast to works that focus on the theoretical performance of abstract MIMO channels, MIMO Communication for Cellular Networks emphasizes the practical performance of realistic MIMO systems. A unified set of system simulation results highlights relative performance gains of different MIMO techniques and provides insights into how best to use multiple antennas in cellular networks under various conditions. MIMO Communication for Cellular Networks describes single-user,...

  8. Cellular proliferation rate and insulin-like growth factor binding protein (IGFBP)-2 and IGFBP-3 and estradiol receptor alpha expression in the mammary gland of dairy heifers naturally infected with gastrointestinal nematodes during development.

    Science.gov (United States)

    Perri, A F; Dallard, B E; Baravalle, C; Licoff, N; Formía, N; Ortega, H H; Becú-Villalobos, D; Mejia, M E; Lacau-Mengido, I M

    2014-01-01

    Mammary ductal morphogenesis during prepuberty occurs mainly in response to insulin-like growth factor-1 (IGF-1) and estradiol stimulation. Dairy heifers infected with gastrointestinal nematodes have reduced IGF-1 levels, accompanied by reduced growth rate, delayed puberty onset, and lower parenchyma-stroma relationship in their mammary glands. Immunohistochemical studies were undertaken to determine variations in cell division rate, IGF-1 system components, and estradiol receptors (ESR) during peripubertal development in the mammary glands of antiparasitic-treated and untreated Holstein heifers naturally infected with gastrointestinal nematodes. Mammary biopsies were taken at 20, 30, 40, and 70 wk of age. Proliferating cell nuclear antigen immunolabeling, evident in nuclei, tended to be higher in the parenchyma of the glands from treated heifers than in those from untreated. Insulin-like growth factor binding proteins (IGFBP) type 2 and type 3 immunolabeling was cytoplasmic and was evident in stroma and parenchyma. The IGFBP2-labeled area was lower in treated than in untreated heifers. In the treated group, a maximal expression of this protein was seen at 40 wk of age, whereas in the untreated group the labeling remained constant. No differences were observed for IGFBP3 between treatment groups or during development. Immunolabeling for α ESR (ESR1) was evident in parenchymal nuclei and was higher in treated than in untreated heifers. In the treated group, ESR1 peaked at 30 wk of age and then decreased. These results demonstrate that the parasite burden in young heifers negatively influence mammary gland development, affecting cell division rate and parameters related to estradiol and IGF-1 signaling in the gland. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  9. Abundant tax protein expression in CD4+ T cells infected with human T-cell lymphotropic virus type I (HTLV-I) is prevented by cytotoxic T lymphocytes.

    Science.gov (United States)

    Hanon, E; Hall, S; Taylor, G P; Saito, M; Davis, R; Tanaka, Y; Usuku, K; Osame, M; Weber, J N; Bangham, C R

    2000-02-15

    The role of the cellular immune response in human T-cell leukemia virus type I (HTLV-I) infection is not fully understood. A persistently activated cytotoxic T lymphocyte (CTL) response to HTLV-I is found in the majority of infected individuals. However, it remains unclear whether this CTL response is protective or causes tissue damage. In addition, several observations paradoxically suggest that HTLV-I is transcriptionally silent in most infected cells and, therefore, not detectable by virus-specific CTLs. With the use of a new flow cytometric procedure, we show here that a high proportion of naturally infected CD4+ peripheral blood mononuclear cells (PBMC) (between 10% and 80%) are capable of expressing Tax, the immunodominant target antigen recognized by virus-specific CTLs. Furthermore, we provide direct evidence that autologous CD8+ T cells rapidly kill CD4+ cells naturally infected with HTLV-I and expressing Tax in vitro by a perforin-dependent mechanism. Consistent with these observations, we observed a significant negative correlation between the frequency of Tax(11-19)-specific CD8+ T cells and the percentage of CD4+ T cells in peripheral blood of patients infected with HTLV-I. Those results are in accordance with the view that virus-specific CTLs participate in a highly efficient immune surveillance mechanism that persistently destroys Tax-expressing HTLV-I-infected CD4+ T cells in vivo. (Blood. 2000;95:1386-1392)

  10. The entomopathogenic fungus Nomuraea rileyi impairs cellular immunity of its host Helicoverpa armigera.

    Science.gov (United States)

    Zhong, Ke; Liu, Zhan-Chi; Wang, Jia-Lin; Liu, Xu-Sheng

    2017-09-01

    In this study, we investigated the effect of the entomopathogenic fungus Nomuraea rileyi on Helicoverpa armigera cellular immune responses. Nomuraea rileyi infection had no effect on total hemocyte count (THC), but impaired hemocyte-mediated phagocytosis, nodulation, and encapsulation responses. Nomuraea rileyi infection led to a significant reduction in hemocyte spreading. An in vitro assay revealed that plasma from N. rileyi infected H. armigera larvae suppressed the spreading ability of hemocytes from naïve larvae. We infer that N. rileyi suppresses the cellular immune response of its host, possibly by secreting exogenous, cytotoxic compounds into the host's hemolymph. © 2017 Wiley Periodicals, Inc.

  11. Programmable cellular arrays. Faults testing and correcting in cellular arrays

    International Nuclear Information System (INIS)

    Cercel, L.

    1978-03-01

    A review of some recent researches about programmable cellular arrays in computing and digital processing of information systems is presented, and includes both combinational and sequential arrays, with full arbitrary behaviour, or which can realize better implementations of specialized blocks as: arithmetic units, counters, comparators, control systems, memory blocks, etc. Also, the paper presents applications of cellular arrays in microprogramming, in implementing of a specialized computer for matrix operations, in modeling of universal computing systems. The last section deals with problems of fault testing and correcting in cellular arrays. (author)

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

    International Nuclear Information System (INIS)

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

    1989-01-01

    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). 45 references

  13. MANUFACTURING NATURAL KILLER CELLS AS MEDICINAL PRODUCTS

    Directory of Open Access Journals (Sweden)

    Christian CHABANNON

    2016-11-01

    Full Text Available Natural Killer (NK cells are Innate Lymphoid Cells (ILC with cytotoxic and regulatory properties. Their functions are tightly regulated by an array of inhibitory and activating receptors, and their mechanisms of activation strongly differ from antigen recognition in the context of HLA presentation as needed for T-cell activation. NK cells thus offer unique opportunities for new and improved therapeutic manipulation, either in vivo or in vitro, in a variety of human diseases, including cancers. NK cell activity can possibly be modulated in vivo through direct or indirect actions exerted by small molecules or monoclonal antibodies. NK cells can also be adoptively transferred following more or less substantial modifications through cell and gene manufacturing, in order to empower them with new or improved functions and ensure their controlled persistence and activity in the recipient. In the present review, we will focus on the technological and regulatory challenges of NK cell manufacturing, and discuss conditions in which these innovative cellular therapies can be brought to the clinic.

  14. Measuring T cell-mediated cytotoxicity using fluorogenic caspase substrates.

    Science.gov (United States)

    Chahroudi, A; Silvestri, G; Feinberg, M B

    2003-10-01

    Cytotoxic T lymphocytes (CTLs) play a major role in the immune response against viruses and other intracellular pathogens. In addition, CTLs are implicated in the control of tumor cells in certain settings. Accurate measures of CTL function are of critical importance to study the pathogenesis of infectious diseases and to evaluate the efficacy of new vaccines and immunotherapies. To this end, we have recently developed a flow cytometry-based CTL (FCC) assay that measures the CTL-induced caspase activation within target cells using cell permeable fluorogenic caspase substrates. This novel assay reliably detects, by flow cytometry or fluorescence/confocal microscopy, antigen-specific CTLs in a wide variety of human and murine systems, and is safer and more informative than the standard 51Cr-release assay. In addition, the flow cytometric CTL (FCC) assay provides an alternative method that is often more sensitive and physiologically informative when compared to previously described FCC assays, as it measures a biological indicator of apoptosis within the target cell. The FCC assay may thus represent a useful tool to further understand the molecular and cellular mechanisms that underlie CTL-mediated killing during tumorigenesis or following infection with viruses or other intracellular pathogens.

  15. Cytotoxic and genotoxic effects of silver nanoparticles in testicular cells

    International Nuclear Information System (INIS)

    Asare, Nana; Instanes, Christine; Sandberg, Wiggo J.; Refsnes, Magne; Schwarze, Per; Kruszewski, Marcin; Brunborg, Gunnar

    2012-01-01

    Serious concerns have been expressed about potential risks of engineered nanoparticles. Regulatory health risk assessment of such particles has become mandatory for the safe use of nanomaterials in consumer products and medicines; including the potential effects on reproduction and fertility, are relevant for this risk evaluation. In this study, we examined effects of silver particles of nano- (20 nm) and submicron- (200 nm) size, and titanium dioxide nanoparticles (TiO 2 -NPs; 21 nm), with emphasis on reproductive cellular- and genotoxicity. Ntera2 (NT2, human testicular embryonic carcinoma cell line), and primary testicular cells from C57BL6 mice of wild type (WT) and 8-oxoguanine DNA glycosylase knock-out (KO, mOgg1 −/− ) genotype were exposed to the particles. The latter mimics the repair status of human testicular cells vs oxidative damage and is thus a suitable model for human male reproductive toxicity studies. The results suggest that silver nano- and submicron-particles (AgNPs) are more cytotoxic and cytostatic compared to TiO 2 -NPs, causing apoptosis, necrosis and decreased proliferation in a concentration- and time-dependent manner. The 200 nm AgNPs in particular appeared to cause a concentration-dependent increase in DNA-strand breaks in NT2 cells, whereas the latter response did not seem to occur with respect to oxidative purine base damage analysed with any of the particles tested.

  16. Cytotoxicity assessment of porous silicon microparticles for ocular drug delivery.

    Science.gov (United States)

    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. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Cytotoxic constituents of ethyl acetate fraction from Dianthus superbus.

    Science.gov (United States)

    Ding, Chengli; Zhang, Wu; Li, Jie; Lei, Jiachuan; Yu, Jianqing

    2013-01-01

    The ethyl acetate fraction (EE-DS) from Dianthus superbus was found to possess the cytotoxic activity against cancer cells in previous study. To investigate cytotoxic constituents, the bioassay-guided isolation of compounds from EE-DS was performed. Two dianthramides (1 and 2), three flavonoids (3-5), two coumarins (6 and 7) and three other compounds (8-10) were obtained. Structures of isolated compounds were identified by spectroscopic analysis. Cytotoxicity of the compounds against HepG2 cells was evaluated. Compound 1 showed the strongest cytotoxicity, compounds 10, 4, 3 and 5 had moderate cytotoxicity.

  18. Multi-scale modeling with cellular automata: The complex automata approach

    NARCIS (Netherlands)

    Hoekstra, A.G.; Falcone, J.-L.; Caiazzo, A.; Chopard, B.

    2008-01-01

    Cellular Automata are commonly used to describe complex natural phenomena. In many cases it is required to capture the multi-scale nature of these phenomena. A single Cellular Automata model may not be able to efficiently simulate a wide range of spatial and temporal scales. It is our goal to

  19. Lipid peroxidation and cytotoxicity induced by respirable volcanic ash

    Energy Technology Data Exchange (ETDEWEB)

    Cervini-Silva, Javiera, E-mail: jcervini@correo.cua.uam.mx [Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana Unidad Cuajimalpa, México City (Mexico); Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Nieto-Camacho, Antonio [Laboratorio de Pruebas Biológicas, Instituto de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, México City (Mexico); Gomez-Vidales, Virginia [Laboratorio de Resonancia Paramagnética Electrónica, Instituto de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, México City (Mexico); Ramirez-Apan, María Teresa [Laboratorio de Pruebas Biológicas, Instituto de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, México City (Mexico); Palacios, Eduardo; Montoya, Ascención [Dirección de Investigación y Posgrado, Instituto Mexicano del Petróleo (Mexico); Kaufhold, Stephan [BGR Bundesansaltfür Geowissenschaften und Rohstoffe, Stilleweg 2, D-30655 Hannover (Germany); and others

    2014-06-01

    Highlights: • Respirable volcanic ash induces oxidative degradation of lipids in cell membranes. • Respirable volcanic ash triggers cytotoxicity in murin monocyle/macrophage cells. • Oxidative stress is surface controlled but not restricted by surface- Fe{sup 3+}. • Surface Fe{sup 3+} acts as a stronger inductor in allophanes vs phyllosilicates or oxides. • Registered cell-viability values were as low as 68.5 ± 6.7%. - Abstract: This paper reports that the main component of respirable volcanic ash, allophane, induces lipid peroxidation (LP), the oxidative degradation of lipids in cell membranes, and cytotoxicity in murin monocyle/macrophage cells. Naturally-occurring allophane collected from New Zealand, Japan, and Ecuador was studied. The quantification of LP was conducted using the Thiobarbituric Acid Reactive Substances (TBARS) assay. The cytotoxic effect was determined by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide colorimetric assay. Electron-Paramagnetic Resonance (EPR) determinations of naturally-occurring allophane confirmed the incorporation in the structure and clustering of structural Fe{sup 3+}, and nucleation and growth of small-sized Fe (oxyhydr)oxide or gibbsite. LP induced by allophane varied with time, and solid concentration and composition, reaching 6.7 ± 0.2 nmol TBARS mg prot{sup −1}. LP was surface controlled but not restricted by structural or surface-bound Fe{sup 3+}, because redox processes induced by soluble components other than perferryl iron. The reactivity of Fe{sup 3+} soluble species stemming from surface-bound Fe{sup 3+} or small-sized Fe{sup 3+} refractory minerals in allophane surpassed that of structural Fe{sup 3+} located in tetrahedral or octahedral sites of phyllosilicates or bulk iron oxides. Desferrioxamine B mesylate salt (DFOB) or ethylenediaminetetraacetic acid (EDTA) inhibited LP. EDTA acted as a more effective inhibitor, explained by multiple electron transfer pathways. Registered cell

  20. Cytotoxicity of Poly(Alkyl Cyanoacrylate Nanoparticles

    Directory of Open Access Journals (Sweden)

    Einar Sulheim

    2017-11-01

    Full Text Available Although nanotoxicology has become a large research field, assessment of cytotoxicity is often reduced to analysis of one cell line only. Cytotoxicity of nanoparticles is complex and should, preferentially, be evaluated in several cell lines with different methods and on multiple nanoparticle batches. Here we report the toxicity of poly(alkyl cyanoacrylate nanoparticles in 12 different cell lines after synthesizing and analyzing 19 different nanoparticle batches and report that large variations were obtained when using different cell lines or various toxicity assays. Surprisingly, we found that nanoparticles with intermediate degradation rates were less toxic than particles that were degraded faster or more slowly in a cell-free system. The toxicity did not vary significantly with either the three different combinations of polyethylene glycol surfactants or with particle size (range 100–200 nm. No acute pro- or anti-inflammatory activity on cells in whole blood was observed.

  1. Improved cytotoxicity testing of magnesium materials

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Janine [Helmholtz-Zentrum Geesthacht, Institute of Materials Research, Department for Structural Research on Macromolecules, Max-Planck Str. 1, D - 21502 Geesthacht (Germany); Proefrock, Daniel [Helmholtz-Zentrum Geesthacht, Institute for Coastal Research, Department for Marine Bioanalytical Chemistry, Max-Planck Str. 1, D - 21502 Geesthacht (Germany); Hort, Norbert [Helmholtz-Zentrum Geesthacht, Institute of Materials Research, Department for Magnesium Processing, Max-Planck Str. 1, D - 21502 Geesthacht (Germany); Willumeit, Regine; Feyerabend, Frank [Helmholtz-Zentrum Geesthacht, Institute of Materials Research, Department for Structural Research on Macromolecules, Max-Planck Str. 1, D - 21502 Geesthacht (Germany)

    2011-06-25

    Metallic magnesium (Mg) and its alloys are highly suitable for medical applications as biocompatible and biodegradable implant materials. Magnesium has mechanical properties similar to bone, stimulates bone regeneration, is an essential non-toxic element for the human body and degrades completely within the body environment. In consequence, magnesium is a promising candidate as implant material for orthopaedic applications. Protocols using the guideline of current ISO standards should be carefully evaluated when applying them for the characterization of the cytotoxic potential of degradable magnesium materials. For as-cast material we recommend using 10 times more extraction medium than recommended by the ISO standards to obtain reasonable results for reliable cytotoxicity rankings of degradable materials in vitro. In addition primary isolated human osteoblasts or mesenchymal stem cells should be used to test magnesium materials.

  2. Improved cytotoxicity testing of magnesium materials

    International Nuclear Information System (INIS)

    Fischer, Janine; Proefrock, Daniel; Hort, Norbert; Willumeit, Regine; Feyerabend, Frank

    2011-01-01

    Metallic magnesium (Mg) and its alloys are highly suitable for medical applications as biocompatible and biodegradable implant materials. Magnesium has mechanical properties similar to bone, stimulates bone regeneration, is an essential non-toxic element for the human body and degrades completely within the body environment. In consequence, magnesium is a promising candidate as implant material for orthopaedic applications. Protocols using the guideline of current ISO standards should be carefully evaluated when applying them for the characterization of the cytotoxic potential of degradable magnesium materials. For as-cast material we recommend using 10 times more extraction medium than recommended by the ISO standards to obtain reasonable results for reliable cytotoxicity rankings of degradable materials in vitro. In addition primary isolated human osteoblasts or mesenchymal stem cells should be used to test magnesium materials.

  3. Characterization of non-dimer DNA lesions and cellular damages caused by ultraviolet light

    International Nuclear Information System (INIS)

    Nakao, Kumi

    1989-01-01

    To understand the mechanisms of carcinogenicity and cytotoxicity induced by ultraviolet (UV) light, non-dimer DNA damages produced by near UV light (wave-length: 290∼320 nm) were examined by alkaline elution using Chinese hamster V-79 cells. UV exposure produced a dose-dependent induction of DNA single strand breaks and DNA-protein crosslinks. However, neither of these DNA lesions were repaired within a 24 hr incubation of the cells following UV exposure. Rather the number of these lesions increased. Also, UV exposure inhibited DNA and RNA synthesis. In addition, UV induced both cytotoxicity and chromosomal aberration. Electron spin resornance (ESR) studies showed that the exposure of cells to UV light resulted in the appearance of an ESR signal at -120degC. The roles of glutathione, vitamin E and vitamin B 2 , which were celluar antioxidant, on the induction of cytotoxicity by UV exposure were also examined. Pretreatment with vitamin E reduced the cytotoxicty caused by UV, whereas neither preteatment with vitamin B 2 nor the alteration of cellular gluthaione content affected the cytotoxicity. These results suggest that non-dimer DNA damages, such as DNA single strand breaks and DNA-protein crosslinks play an important role in inducing UV-carcinogenicity and UV-cytotoxicity, and that the mechanisms of these damages may be associated with the generation of free radicals. (author)

  4. Annona muricata leaves have strongest cytotoxic activity against breast cancer cells

    Directory of Open Access Journals (Sweden)

    Susi Endrini

    2014-12-01

    Full Text Available Background Plant-derived herbal compounds have a long history of clinical use, better patient tolerance and acceptance. They are freely available natural compounds that can be safely used to prevent various ailments. Plants have been the basis of traditional medicine throughout the world for thousands of years and are providing mankind with new remedies. The objective of this study was to determine the cytotoxicity of soursop (Anona muricata Linn leaves and pearl grass (Hedyotis corymbosa (L. Lam. on the hormone-dependent human breast carcinoma Michigan Cancer Foundation-7 (MCF-7 cell line. Methods This study used two types of solvents (water and ethanol in the extraction process and two incubation times (24 hours and 48 hours in the MTT assays to analyze the cytotoxic effects of both plants. Results Preliminary results showed that the ethanolic extract of soursop leaves (SE displayed cytotoxic effects against MCF-7 on 24- and 48-hour incubation times with IC50 values of 88.788 ìg/ml and 14.678 mg/ml, respectively. Ethanolic pearl grass extract (PE showed similar results, with IC50 values of 65.011 mg/ml on 24-hour incubation time and 52.329 mg/ml on 48-hour incubation time against MCF-7 cell line. However, the water extract of both plants displayed lower cytotoxic effect against MCF-7 cell line. Conclusion The ethanolic extract of both plants displayed cytotoxic effect against MCF-7. Soursop (Anona muricata Linn leaves have the strongest cytotoxic activity against MCF-7 breast cancer cell line.

  5. A cytotoxic study of eugenol and its ortho dimer (bis-eugenol)

    Energy Technology Data Exchange (ETDEWEB)

    Kashiwagi, Yasushi [Meikai Univ., Sakado, Saitama (Japan). School of Dentistry

    2000-07-01

    Eugenol is widely used not only as a dental material such as pulp capping material, provisional cement, root canal sealer, and impression paste, but also as a perfume ingredients. Eugenol has antioxidant, bactericidal, and sedative activities, inhibits and non-enzymatic peroxidation. It was previously reported that eugenol exhibited the cytotoxic activity toward pulp cells and gingial fibroblasts and also that the cytotoxic activity was predominantly performed by radicals derived from the oxidation of eugenol. This study was based on the hypothesis that the toxicity of eugenol may be greately reduced if the radicalization of eugenol was diminished by the dimerization of eugenol. Thus, bis-eugenol, the dimer of eugenol, was synthesized to characterize the effect of this eugenol-related compound. The cytotoxic activity of bis-eugenol against human gingival fibroblasts (HGF cell) or human submandibular gland cancer cells (HSG cell) was studied in the presence or absence of light irradiation (visible or ultraviolet light), and compared with that of eugenol. The cytotoxic activity of eugenol was significantly greater than that of bis-eugenol. The cytotoxic activity of irradiated eugenol, but not that of irradiated bis-eugenol, was significantly higher than that of the non-irradiated counterpart. Bis-eugenol at a relatively low concentration declined the phototoxic activity of irradiation on living cells. Also, the generation of reactive oxygen in HSG cells in the ab-sence or the presence of irradiated bis-eugenol or eugenol was evaluated by an ACAS laser cytometry, and the results indicated that eugenol, but not bis-eugenol, generated reactive oxygen in the cells. The DPPH-radical scavenging activity of bis-eugenol was larger than that of eugenol. Furthermore, eugenol had a positive apoptosis-inducing effect on HSG cells. The structure-activity relationships of eugenol-related compounds showed that the nature of the substituent at the ortho or para-position of eugenol

  6. Annona muricata leaves have strongest cytotoxic activity against breast cancer cells

    Directory of Open Access Journals (Sweden)

    Susi Endrini

    2015-12-01

    Full Text Available BACKGROUND Plant-derived herbal compounds have a long history of clinical use, better patient tolerance and acceptance. They are freely available natural compounds that can be safely used to prevent various ailments. Plants have been the basis of traditional medicine throughout the world for thousands of years and are providing mankind with new remedies. The objective of this study was to determine the cytotoxicity of soursop (Anona muricata Linn leaves and pearl grass (Hedyotis corymbosa (L. Lam. on the hormone-dependent human breast carcinoma Michigan Cancer Foundation-7 (MCF-7 cell line. METHODS This study used two types of solvents (water and ethanol in the extraction process and two incubation times (24 hours and 48 hours in the MTT assays to analyze the cytotoxic effects of both plants. RESULTS Preliminary results showed that the ethanolic extract of soursop leaves (SE displayed cytotoxic effects against MCF-7 on 24- and 48-hour incubation times with IC50 values of 88.788 μg/ml and 14.678 μg/ml, respectively. Ethanolic pearl grass extract (PE showed similar results, with IC50 values of 65.011 μg/ ml on 24-hour incubation time and 52.329 μg/ml on 48-hour incubation time against MCF-7 cell line. However, the water extract of both plants displayed lower cytotoxic effect against MCF-7 cell line. CONCLUSION The ethanolic extract of both plants displayed cytotoxic effect against MCF-7. Soursop (Anona muricata Linn leaves have the strongest cytotoxic activity against MCF-7 breast cancer cell line.

  7. A cytotoxic study of eugenol and its ortho dimer (bis-eugenol)

    International Nuclear Information System (INIS)

    Kashiwagi, Yasushi

    2000-01-01

    Eugenol is widely used not only as a dental material such as pulp capping material, provisional cement, root canal sealer, and impression paste, but also as a perfume ingredients. Eugenol has antioxidant, bactericidal, and sedative activities, inhibits and non-enzymatic peroxidation. It was previously reported that eugenol exhibited the cytotoxic activity toward pulp cells and gingial fibroblasts and also that the cytotoxic activity was predominantly performed by radicals derived from the oxidation of eugenol. This study was based on the hypothesis that the toxicity of eugenol may be greately reduced if the radicalization of eugenol was diminished by the dimerization of eugenol. Thus, bis-eugenol, the dimer of eugenol, was synthesized to characterize the effect of this eugenol-related compound. The cytotoxic activity of bis-eugenol against human gingival fibroblasts (HGF cell) or human submandibular gland cancer cells (HSG cell) was studied in the presence or absence of light irradiation (visible or ultraviolet light), and compared with that of eugenol. The cytotoxic activity of eugenol was significantly greater than that of bis-eugenol. The cytotoxic activity of irradiated eugenol, but not that of irradiated bis-eugenol, was significantly higher than that of the non-irradiated counterpart. Bis-eugenol at a relatively low concentration declined the phototoxic activity of irradiation on living cells. Also, the generation of reactive oxygen in HSG cells in the ab-sence or the presence of irradiated bis-eugenol or eugenol was evaluated by an ACAS laser cytometry, and the results indicated that eugenol, but not bis-eugenol, generated reactive oxygen in the cells. The DPPH-radical scavenging activity of bis-eugenol was larger than that of eugenol. Furthermore, eugenol had a positive apoptosis-inducing effect on HSG cells. The structure-activity relationships of eugenol-related compounds showed that the nature of the substituent at the ortho or para-position of eugenol

  8. Resistance to degradation and cellular distribution are important features for the antitumor activity of gomesin.

    Directory of Open Access Journals (Sweden)

    Marcus V Buri

    Full Text Available 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. [Thr(2,6,11,15]-Gm, and [Ser(2,6,11,15]-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-Thr(2,6,11,15]-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-Thr(2,6,11,15, Pro(9]-D-Gm, and [Thr(2,6,11,15, D-Pro(9]-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.

  9. Resistance to degradation and cellular distribution are important features for the antitumor activity of gomesin.

    Science.gov (United States)

    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. [Thr(2,6,11,15)]-Gm, and [Ser(2,6,11,15)]-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-Thr(2,6,11,15)]-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-Thr(2,6,11,15), Pro(9)]-D-Gm, and [Thr(2,6,11,15), D-Pro(9)]-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.

  10. Resistance to Degradation and Cellular Distribution are Important Features for the Antitumor Activity of Gomesin

    Science.gov (United States)

    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

  11. Study of Cytotoxic Effects of Benzonitrile Pesticides

    OpenAIRE

    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, rep...

  12. Reduced LAK cytotoxicity of peripheral blood mononuclear cells in patients with bladder cancer: Decreased LAK cytotoxicity caused by a low incidence of CD56+ and CD57+ mononuclear blood cells

    International Nuclear Information System (INIS)

    Hermann, G.G.; Petersen, K.R.; Steven, K.; Zeuthen, J.

    1990-01-01

    The cytotoxicity of unstimulated peripheral blood mononuclear cells (US-PBMC), phytohemagglutinin (PHA)-stimulated PBMC (PS-PBMC) and interleukin-2 (IL-2)-activated PBMC (LAK cells) was assessed in patients with noninvasive and invasive transitional-cell bladder cancer and compared with those determined in healthy controls. The differences in the cytotoxicities were correlated with specific changes in the subsets of peripheral blood mononuclear cells (PBMC). PBMC from 37 patients and 13 healthy controls were tested against the bladder cancer cell line T24 in 51 Cr-release assays. The PBMC subsets were analyzed using monoclonal antibodies against T cells, natural killer (NK) -cells, monocytes, and activation markers. The cytotoxicities of US-PBMC, PS-PBMC, and LAK cells were all significantly lower in the cancer patients than in the controls (P less than 0.05). The percentages of PBMC positive for the NK-cell markers CD56 and CD57 were lowest in the patients and were correlated to the decrease in cytotoxicity. Depletion of CD56+ or CD57+ cells from PBMC prior to or after 2 days stimulation with IL-2 demonstrated that these cells are the major source of LAK-cell cytotoxicity and showed that the reduced ability of bladder cancer patient PBMC to develop LAK-cell cytotoxicity is a result of a low incidence of CD56+ and CD57+ cells in the blood. These findings indicate that IL-2 therapy alone might not be a sufficient therapy of bladder cancer patients

  13. Cytotoxic triterpenoid saponins from Clematis tangutica.

    Science.gov (United States)

    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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Cytotoxic and phytotoxic actions of Heliotropium strigosum.

    Science.gov (United States)

    Shah, Syed Majid; Hussain, Sajid; Khan, Arif-Ullah; Shah, Azhar-Ul-Haq Ali; Khan, Haroon; Ullah, Farhat; Barkatullah

    2015-05-01

    This study describes the cytotoxic and phytotoxic activities of the crude extract of Heliotropium strigosum and its resultant fractions. In brine shrimp toxicology assays, profound cytotoxicity was displayed by ethyl acetate (LD50 8.3 μg/ml) and chloroform (LD50 8.8 μg/ml) fractions, followed by relatively weak crude methanolic extract of H. strigosum (LD50 909 μg/ml) and n-hexane fraction (LD50 1000 μg/ml). In case of phytotoxicity activity against Lemna acquinoctialis, highest phytotoxic effect was showed by ethyl acetate fraction (LD50 91.0 μg/ml), while chloroform fraction, plant crude extract and n-hexane, respectively, caused 50%, 30.76 ± 1.1% and 30.7 ± 1.1% inhibitory action at maximum concentration used, that is, 1000 μg/ml. These data indicates that H. strigosum exhibits cytotoxic and phytotoxic potential, which explore its use as anticancer and herbicidal medicine. The ethyl acetate and chloroform fractions were more potent for the evaluated toxicity effects, thus recommended for isolation and identification of the active compounds. © The Author(s) 2012.

  15. Cytotoxic constituents of Soymida febrifuga from Myanmar.

    Science.gov (United States)

    Awale, Suresh; Miyamoto, Tatsuya; Linn, Thein Zaw; Li, Feng; Win, Nwet Nwet; Tezuka, Yasuhiro; Esumi, Hiroyasu; Kadota, Shigetoshi

    2009-09-01

    The 70% ethanol extract of Soymida febrifuga was found to kill PANC-1 human pancreatic cancer cells preferentially under nutrition-deprived conditions at a concentration of 10 microg/mL. Phytochemical investigation led to the isolation of 27 compounds including four new compounds [(3R)-6,4'-dihydroxy-8-methoxyhomoisoflavan (1), (2R)-7,4'-dihydroxy-5-methoxy-8-methylflavan (2), 7-hydroxy-6-methoxy-3-(4'-hydroxybenzyl)coumarin (3), and 6-hydroxy-7-methoxy-3-(4'-hydroxybenzyl)coumarin (4)]. 2',4'-Dihydroxychalcone (8) displayed the most potent preferential cytotoxicity (PC(50) 19.0 microM) against PANC-1 cells. In addition, the cytotoxic activity against colon 26-L5 carcinoma (colon 26-L5), B16-BL6 melanoma (B16-BL6), lung A549 adenocarcinoma (A549), cervix HeLa adenocarcinoma (HeLa), and HT-1080 fibrosarcoma (HT-1080) cell lines and their structure-activity relationship are discussed. The cytotoxic activity of 4'-hydroxy-3,5-dimethoxystilbene (6) against colon 26-L5 (IC(50) 2.96 microM) was found to be stronger than the positive control, doxorubicin, at IC(50) 3.12 microM.

  16. Top-down cellular pyramids

    Energy Technology Data Exchange (ETDEWEB)

    Wu, A Y; Rosenfeld, A

    1983-10-01

    A cellular pyramid is an exponentially tapering stack of arrays of processors (cells), where each cell is connected to its neighbors (siblings) on its own level, to a parent on the level above, and to its children on the level below. It is shown that in some situations, if information flows top-down only, from fathers to sons, then a cellular pyramid may be no faster than a one-level cellular array; but it may be possible to use simpler cells in the pyramid case. 23 references.

  17. Intractable problems in reversible cellular automata

    International Nuclear Information System (INIS)

    Vatan, F.

    1988-01-01

    The billiard ball model, a classical mechanical system in which all parameters are real variables, can perform all digital computations. An eight-state, 11-neighbor reversible cellular automaton (an entirely discrete system in which all parameters are integer variables) can simulate this model. One of the natural problems for this system is to determine the shape of a container so that they initial specific distribution of gas molecules eventually leads to a predetermined distribution. This problem if PSPACE-complete. Related intractable and decidable problems are discussed as well

  18. Comparative cytotoxicity assessments of some manufactured and anthropogenic nanoparticulate materials

    Science.gov (United States)

    Soto, Karla Fabiola

    Due to increasing diversity of newly engineered nanoparticles, it is important to consider the hazards of these materials. Very little is known regarding the potential toxicity of relatively new nanomaterials. However, beginning with several historical accounts of nanomaterials applications---chrysotile asbestos and silver---it was assumed that these examples would provide some awareness and guidelines for future nanomaterial and nanotechnology applications, especially health effects. In this study in vitro assays were performed on a murine alveolar macrophage cell line (RAW 264.7), human alveolar macrophage cell line (THB-1), and human epithelial lung cell line (A549) to assess the comparative cytotoxicity of a wide range of manufactured (Ag, TiO2, Fe2O3, Al2O3, ZrO2, black carbon, two different types of multiwall structures and chrysotile asbestos as the toxicity standard) and anthropogenic nanoparticulates. There are several parameters of nanoparticulates that are considered to trigger an inflammatory response (particularly respiratory) or cause toxicity. These parameters include: particle size, shape, specific surface area, transition metals in particulates, and organic compounds. Therefore, a wide variety of manufactured and anthropogenic nanoparticulates having different morphologies, sizes, specific surface area and chemistries as noted were tested. To determine the nanoparticulates' size and morphology, they were characterized by transmission electron microscopy, where it was observed that the commercial multiwall carbon nanotube aggregate had an identical morphology to chrysotile asbestos and combustion-formed carbon nanotubes, i.e.; those that form from natural gas combustion. Light optical microscopy was used to determine cell morphology upon exposure to nanoparticulates as an indication of cell death. Also, the polycyclic aromatic hydrocarbon (PAH) content of the collected nanoparticulates was analyzed and correlated with cytotoxic responses. For

  19. Anti-Melanogenic Activity and Cytotoxicity of Pistacia vera Hull on Human Melanoma SKMEL-3 Cells.

    Science.gov (United States)

    Sarkhail, Parisa; Salimi, Mona; Sarkheil, Pantea; Mostafapour Kandelous, Hirsa

    2017-07-01

    Pistacia vera seed is a common food and medicinal seed in Iran. It's hull (outer skin) as a significant byproduct of pistachio, is traditionally used as tonic, sedative and antidiarrheal and has been shown to be a rich source of antioxidants. The aim of the present study is to evaluate the anti-melanogenic activity of the pistachio hulls in order to discover a new alternative herbal agent to treat skin hyperpigmentation disorders. In this work, antioxidant and anti-tyrosinase activity of MeOH extract from Pistacia vera hull (MPH) were evaluated in vitro, respectively, by DPPH radical scavenging and mushroom tyrosinase activity assays. Then the effect of MPH on the melanin content, cellular tyrosinase activity and cytotoxicity (MTT assay) on human melanoma SKMEL-3 cell were determined followed by 72 h incubation. The results indicated that MPH had valuable DPPH radical scavenging effect and weak anti-tyrosinase activity when compared to the well-known antioxidant (BHT) and tyrosinase inhibitor (kojic acid), respectively. MPH, at a high dose (0.5 mg/mL), showed significant cytotoxic activity (~63%) and strong anti-melanogenic effect (~57%) on SKMEL-3 cells. The effect of MPH in the reduction of melanin content may be related to its cytotoxicity. The results obtained suggest that MPH can be used as an effective agent in the treatment of some skin hyperpigmentation disorders such as melanoma.

  20. Evaluating Cytotoxicity of Hyaluronate Targeted Solid Lipid Nanoparticles of Etoposide on SK-OV-3 Cells

    Directory of Open Access Journals (Sweden)

    Parviz Mohammadi Ghalaei

    2014-01-01

    Full Text Available 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.

  1. Mulberry Fruit Extract Affords Protection against Ethyl Carbamate-Induced Cytotoxicity and Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Wei Chen

    2017-01-01

    Full Text Available Ethyl carbamate (EC is a food and environmental toxicant and is a cause of concern for human exposure. Several studies indicated that EC-induced toxicity was associated with oxidative stress. Mulberry fruits are reported to have a wide range of bioactive compounds and pharmacological activities. The present study was therefore aimed to investigate the protective property of mulberry fruit extract (MFE on EC-induced cytotoxicity and oxidative stress. Chemical composition analysis showed that total phenolic content and total flavonoid content in MFE were 502.43 ± 5.10 and 219.12 ± 4.45 mg QE/100 g FW. Cyanidin-3-O-glucoside and cyanidin-3-O-rutinoside were the major anthocyanins in MFE. In vitro antioxidant studies (DPPH, ABTS, and FRAP assays jointly exhibited the potent antioxidant capacity of MFE. Further study indicated that MFE protected human liver HepG2 cells from EC-induced cytotoxicity by scavenging overproduced cellular ROS. EC treatment promoted intracellular glutathione (GSH depletion and caused mitochondrial membrane potential (MMP collapse, as well as mitochondrial membrane lipid peroxidation, whereas MFE pretreatment significantly inhibited GSH depletion and restored the mitochondrial membrane function. Overall, our study suggested that polyphenolic-rich MFE could afford a potent protection against EC-induced cytotoxicity and oxidative stress.

  2. HDACi: cellular effects, opportunities for restorative dentistry.

    LENUS (Irish Health Repository)

    Duncan, H F

    2011-12-01

    Acetylation of histone and non-histone proteins alters gene expression and induces a host of cellular effects. The acetylation process is homeostatically balanced by two groups of cellular enzymes, histone acetyltransferases (HATs) and histone deacetylases (HDACs). HAT activity relaxes the structure of the human chromatin, rendering it transcriptionally active, thereby increasing gene expression. In contrast, HDAC activity leads to gene silencing. The enzymatic balance can be \\'tipped\\' by histone deacetylase inhibitors (HDACi), leading to an accumulation of acetylated proteins, which subsequently modify cellular processes including stem cell differentiation, cell cycle, apoptosis, gene expression, and angiogenesis. There is a variety of natural and synthetic HDACi available, and their pleiotropic effects have contributed to diverse clinical applications, not only in cancer but also in non-cancer areas, such as chronic inflammatory disease, bone engineering, and neurodegenerative disease. Indeed, it appears that HDACi-modulated effects may differ between \\'normal\\' and transformed cells, particularly with regard to reactive oxygen species accumulation, apoptosis, proliferation, and cell cycle arrest. The potential beneficial effects of HDACi for health, resulting from their ability to regulate global gene expression by epigenetic modification of DNA-associated proteins, also offer potential for application within restorative dentistry, where they may promote dental tissue regeneration following pulpal damage.

  3. Cellular Kinetics of Perivascular MSC Precursors

    Directory of Open Access Journals (Sweden)

    William C. W. Chen

    2013-01-01

    Full Text Available Mesenchymal stem/stromal cells (MSCs and MSC-like multipotent stem/progenitor cells have been widely investigated for regenerative medicine and deemed promising in clinical applications. In order to further improve MSC-based stem cell therapeutics, it is important to understand the cellular kinetics and functional roles of MSCs in the dynamic regenerative processes. However, due to the heterogeneous nature of typical MSC cultures, their native identity and anatomical localization in the body have remained unclear, making it difficult to decipher the existence of distinct cell subsets within the MSC entity. Recent studies have shown that several blood-vessel-derived precursor cell populations, purified by flow cytometry from multiple human organs, give rise to bona fide MSCs, suggesting that the vasculature serves as a systemic reservoir of MSC-like stem/progenitor cells. Using individually purified MSC-like precursor cell subsets, we and other researchers have been able to investigate the differential phenotypes and regenerative capacities of these contributing cellular constituents in the MSC pool. In this review, we will discuss the identification and characterization of perivascular MSC precursors, including pericytes and adventitial cells, and focus on their cellular kinetics: cell adhesion, migration, engraftment, homing, and intercellular cross-talk during tissue repair and regeneration.

  4. Light Weight Biomorphous Cellular Ceramics from Cellulose Templates

    Science.gov (United States)

    Singh, Mrityunjay; Yee, Bo-Moon; Gray, Hugh R. (Technical Monitor)

    2003-01-01

    Bimorphous ceramics are a new class of materials that can be fabricated from the cellulose templates derived from natural biopolymers. These biopolymers are abundantly available in nature and are produced by the photosynthesis process. The wood cellulose derived carbon templates have three- dimensional interconnectivity. A wide variety of non-oxide and oxide based ceramics have been fabricated by template conversion using infiltration and reaction-based processes. The cellular anatomy of the cellulose templates plays a key role in determining the processing parameters (pyrolysis, infiltration conditions, etc.) and resulting ceramic materials. The processing approach, microstructure, and mechanical properties of the biomorphous cellular ceramics (silicon carbide and oxide based) have been discussed.

  5. Cellular senescence and organismal aging.

    Science.gov (United States)

    Jeyapalan, Jessie C; Sedivy, John M

    2008-01-01

    Cellular senescence, first observed and defined using in vitro cell culture studies, is an irreversible cell cycle arrest which can be triggered by a variety of factors. Emerging evidence suggests that cellular senescence acts as an in vivo tumor suppression mechanism by limiting aberrant proliferation. It has also been postulated that cellular senescence can occur independently of cancer and contribute to the physiological processes of normal organismal aging. Recent data have demonstrated the in vivo accumulation of senescent cells with advancing age. Some characteristics of senescent cells, such as the ability to modify their extracellular environment, could play a role in aging and age-related pathology. In this review, we examine current evidence that links cellular senescence and organismal aging.

  6. Origami interleaved tube cellular materials

    International Nuclear Information System (INIS)

    Cheung, Kenneth C; Tachi, Tomohiro; Calisch, Sam; Miura, Koryo

    2014-01-01

    A novel origami cellular material based on a deployable cellular origami structure is described. The structure is bi-directionally flat-foldable in two orthogonal (x and y) directions and is relatively stiff in the third orthogonal (z) direction. While such mechanical orthotropicity is well known in cellular materials with extruded two dimensional geometry, the interleaved tube geometry presented here consists of two orthogonal axes of interleaved tubes with high interfacial surface area and relative volume that changes with fold-state. In addition, the foldability still allows for fabrication by a flat lamination process, similar to methods used for conventional expanded two dimensional cellular materials. This article presents the geometric characteristics of the structure together with corresponding kinematic and mechanical modeling, explaining the orthotropic elastic behavior of the structure with classical dimensional scaling analysis. (paper)

  7. Origami interleaved tube cellular materials

    Science.gov (United States)

    Cheung, Kenneth C.; Tachi, Tomohiro; Calisch, Sam; Miura, Koryo

    2014-09-01

    A novel origami cellular material based on a deployable cellular origami structure is described. The structure is bi-directionally flat-foldable in two orthogonal (x and y) directions and is relatively stiff in the third orthogonal (z) direction. While such mechanical orthotropicity is well known in cellular materials with extruded two dimensional geometry, the interleaved tube geometry presented here consists of two orthogonal axes of interleaved tubes with high interfacial surface area and relative volume that changes with fold-state. In addition, the foldability still allows for fabrication by a flat lamination process, similar to methods used for conventional expanded two dimensional cellular materials. This article presents the geometric characteristics of the structure together with corresponding kinematic and mechanical modeling, explaining the orthotropic elastic behavior of the structure with classical dimensional scaling analysis.

  8. Cellular Angiofibroma of the Nasopharynx.

    Science.gov (United States)

    Erdur, Zülküf Burak; Yener, Haydar Murat; Yilmaz, Mehmet; Karaaltin, Ayşegül Batioğlu; Inan, Hakki Caner; Alaskarov, Elvin; Gozen, Emine Deniz

    2017-11-01

    Angiofibroma is a common tumor of the nasopharynx region but cellular type is extremely rare in head and neck. A 13-year-old boy presented with frequent epistaxis and nasal obstruction persisting for 6 months. According to the clinical symptoms and imaging studies juvenile angiofibroma was suspected. Following angiographic embolization total excision of the lesion by midfacial degloving approach was performed. Histological examination revealed that the tumor consisted of staghorn blood vessels and irregular fibrous stroma. Stellate fibroblasts with small pyknotic to large vesicular nuclei were seen in a highly cellular stroma. These findings identified cellular angiofibroma mimicking juvenile angiofibroma. This article is about a very rare patient of cellular angiofibroma of nasopharynx.

  9. Cytotoxicity and Initial Biocompatibility of Endodontic Biomaterials (MTA and Biodentine™) Used as Root-End Filling Materials.

    Science.gov (United States)

    Escobar-García, Diana María; Aguirre-López, Eva; Méndez-González, Verónica; Pozos-Guillén, Amaury

    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.

  10. Cytotoxic and biological effects of bulk fill composites on rat cortical neuron cells.

    Science.gov (United States)

    Kamalak, Hakan; Kamalak, Aliye; Taghizadehghalehjoughi, Ali; Hacımüftüoğlu, Ahmet; Nalcı, Kemal Alp

    2018-03-28

    The aim of this study was to investigate potential cellular responses and biological effects of new generation dental composites on cortical neuron cells in two different exposure times. The study group included five different bulk-fill flow able composites; Surefil SDR Flow, X-tra Base Flow, Venus Bulk Flow, Filtek Bulk Flow and Tetric-Evo Flow. They were filled in Teflon molds (Height: 4 mm, Width: 6 mm) and irradiated for 20 s. Cortical neuron cells were inoculated into 24-well plates. After 80% of the wells were coated, the 3 µm membrane was inserted and dental filling materials were added. The experiment was continued for 24 and 72 h. Cell viability measured by MTT assay test, total antioxidant and total oxidant status were examined using real assay diagnostic kits. The patterns of cell death (apoptosis) were analyzed using annexin V-FITC staining with flow cytometry. Β-defensins were quantitatively assessed by RT-PCR. IL-6, IL-8 and IL-10 cytokines were measured from the supernatants. All composites significantly affected analyses parameters during the exposure durations. Our data provide evidence that all dental materials tested are cytotoxic in acute phase and these effects are induced cellular death after different exposure periods. Significant cytotoxicity was detected in TE, XB, SS, FBF and VBF groups at 24 and 72 h, respectively.

  11. Rhodium metalloinsertor binding generates a lesion with selective cytotoxicity for mismatch repair-deficient cells.

    Science.gov (United States)

    Bailis, Julie M; Weidmann, Alyson G; Mariano, Natalie F; Barton, Jacqueline K

    2017-07-03

    The DNA mismatch repair (MMR) pathway recognizes and repairs errors in base pairing and acts to maintain genome stability. Cancers that have lost MMR function are common and comprise an important clinical subtype that is resistant to many standard of care chemotherapeutics such as cisplatin. We have identified a family of rhodium metalloinsertors that bind DNA mismatches with high specificity and are preferentially cytotoxic to MMR-deficient cells. Here, we characterize the cellular mechanism of action of the most potent and selective complex in this family, [Rh(chrysi)(phen)(PPO)] 2+ (Rh-PPO). We find that Rh-PPO binding induces a lesion that triggers the DNA damage response (DDR). DDR activation results in cell-cycle blockade and inhibition of DNA replication and transcription. Significantly, the lesion induced by Rh-PPO is not repaired in MMR-deficient cells, resulting in selective cytotoxicity. The Rh-PPO mechanism is reminiscent of DNA repair enzymes that displace mismatched bases, and is differentiated from other DNA-targeted chemotherapeutics such as cisplatin by its potency, cellular mechanism, and selectivity for MMR-deficient cells.

  12. Synthesis of racemic and chiral albicanol, albicanyl acetate and cyclozonarone: cytotoxic activity of ent-cyclozonarone

    International Nuclear Information System (INIS)

    Delgado, Virginia; Armstrong, Veronica; Cortes, Manuel; Barrero, Alejandro F.

    2008-01-01

    The total synthesis of racemic cyclozonarone ((±)-3) was achieved from E,E-farnesol (4) in an eight-step sequence in 6.6% overall yield. Albicanol ((±)-1) and its acetate ((±)-2) are intermediates. A similar sequence starting from natural (-)-drimenol (5) gave (+)-albicanol (1) and (+)-cyclozonarone (3) (42% and 11% yield, respectively). The cytotoxic activity of (+)-cyclozonarone was assayed and showed some selectivity towards MS-1 (mice endothelial cells). (author)

  13. Evaluation of the cytotoxicity of the Bithionol - cisplatin combination in a panel of human ovarian cancer cell lines.

    Science.gov (United States)

    Ayyagari, Vijayalakshmi N; Hsieh, Tsung-Han Jeff; Diaz-Sylvester, Paula L; Brard, Laurent

    2017-01-13

    Combination drug therapy appears a promising approach to overcome drug resistance and reduce drug-related toxicities in ovarian cancer treatments. In this in vitro study, we evaluated the antitumor efficacy of cisplatin in combination with Bithionol (BT) against a panel of ovarian cancer cell lines with special focus on cisplatin-sensitive and cisplatin-resistant cell lines. The primary objectives of this study are to determine the nature of the interactions between BT and cisplatin and to understand the mechanism(s) of action of BT-cisplatin combination. The cytotoxic effects of drugs either alone or in combination were evaluated using presto-blue assay. Cellular reactive oxygen species were measured by flow cytometry. Immunoblot analysis was carried out to investigate changes in levels of cleaved PARP, XIAP, bcl-2, bcl-xL, p21 and p27. Luminescent and colorimetric assays were used to test caspases 3/7 and ATX activity. The efficacy of the BT-cisplatin combination depends upon the cell type and concentrations of cisplatin and BT. In cisplatin-sensitive cell lines, BT and cisplatin were mostly antagonistic except when used at low concentrations, where synergy was observed. In contrast, in cisplatin-resistant cells, BT-cisplatin combination treatment displayed synergistic effects at most of the drug ratios/concentrations. Our results further revealed that the synergistic interaction was linked to increased reactive oxygen species generation and apoptosis. Enhanced apoptosis was correlated with loss of pro-survival factors (XIAP, bcl-2, bcl-xL), expression of pro-apoptotic markers (caspases 3/7, PARP cleavage) and enhanced cell cycle regulators p21 and p27. In cisplatin-resistant cell lines, BT potentiated cisplatin-induced cytotoxicity at most drug ratios via enhanced ROS generation and modulation of key regulators of apoptosis. Low doses of BT and cisplatin enhanced efficiency of cisplatin treatment in all the ovarian cancer cell lines tested. Our results suggest

  14. Identification of cytotoxic drugs that selectively target tumor cells with MYC overexpression.

    Directory of Open Access Journals (Sweden)

    Anna Frenzel

    Full Text Available Expression of MYC is deregulated in a wide range of human cancers, and is often associated with aggressive disease and poorly differentiated tumor cells. Identification of compounds with selectivity for cells overexpressing MYC would hence be beneficial for the treatment of these tumors. For this purpose we used cell lines with conditional MYCN or c-MYC expression, to screen a library of 80 conventional cytotoxic compounds for their ability to reduce tumor cell viability and/or growth in a MYC dependent way. We found that 25% of the studied compounds induced apoptosis and/or inhibited proliferation in a MYC-specific manner. The activities of the majority of these were enhanced both by c-MYC or MYCN over-expression. Interestingly, these compounds were acting on distinct cellular targets, including microtubules (paclitaxel, podophyllotoxin, vinblastine and topoisomerases (10-hydroxycamptothecin, camptothecin, daunorubicin, doxorubicin, etoposide as well as DNA, RNA and protein synthesis and turnover (anisomycin, aphidicholin, gliotoxin, MG132, methotrexate, mitomycin C. Our data indicate that MYC overexpression sensitizes cells to disruption of specific pathways and that in most cases c-MYC and MYCN overexpression have similar effects on the responses to cytotoxic compounds. Treatment of the cells with topoisomerase I inhibitors led to down-regulation of MYC protein levels, while doxorubicin and the small molecule MYRA-A was found to disrupt MYC-Max interaction. We conclude that the MYC pathway is only targeted by a subset of conventional cytotoxic drugs currently used in the clinic. Elucidating the mechanisms underlying their specificity towards MYC may be of importance for optimizing treatment of tumors with MYC deregulation. Our data also underscores that MYC is an attractive target for novel therapies and that cellular screenings of chemical libraries can be a powerful tool for identifying compounds with a desired biological activity.

  15. Uptake and cytotoxic effects of multi-walled carbon nanotubes in human bronchial epithelial cells

    International Nuclear Information System (INIS)

    Hirano, Seishiro; Fujitani, Yuji; Furuyama, Akiko; Kanno, Sanae

    2010-01-01

    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 50 of MWCNT was 12 μg/ml, whereas that of asbestos (crocidolite) was 678 μg/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 μg/ml. BEAS-2B cells were exposed to 2, 5, or 10 μg/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-κB or AP-1 promoter linked to the luciferase gene in transiently transfected CHO-KI cells revealed that NF-κB was activated following MWCNT exposure, while AP-1 was not changed. Collectively, MWCNT activated NF-κB, enhanced phosphorylation of MAP kinase pathway components, and increased production of proinflammatory cytokines in human bronchial epithelial cells.

  16. Comparison of UVA induced cytotoxicity by iodoHoechst isomers

    International Nuclear Information System (INIS)

    Karagiannis, T.C.; Lobachevsky, P.N.; Martin, R.F.

    2003-01-01

    Full text: Isomers of the DNA minor groove binding ligand, iodoHoechst, have been shown to sensitise DNA to cleavage by ultraviolet type A (UVA). The DNA damage has been attributed to formation of a carbon-centred radical upon UVA induced dehalogenation of the drugs. Comparison of the efficacy of the ligands in inducing DNA single strand breaks in plasmid DNA has indicated that the ortho isomer is more efficient than the para- and meta-isomers, mainly due to a greater cross-section for dehalogenation, and to some extent from increased efficiency of DNA damage per dehalogenation event. In the present study, the efficiency of dehalogenation and cytotoxicity of the three iodoHoechst isomers has been compared in human erythroleukemic, K562 cells. The uptake of the iodoHoechst compounds in K562 nuclei has been measured, and the photoefficiency of the cellular associated dehalogenation by UVA has been established for the three isomers. The results indicate that the sensitivity to UVA mediated dehalogenation is much higher for the ortho analogue compared to the para and meta-analogues. Values of the UVA D37 doses for the ortho, para and meta isomers are 49 ± 2, 327 ± 29 and 251 ± 32 J/m 2 , respectively. Clonogenic survival assays have been used to compare the efficiency of sensitisation of cells to UVA irradiation by the analogues. The ortho analogue exhibits higher efficiency compared to the meta and para analogues. The numbers of dehalogenation events required for cell kill have been calculated from the clonogenic survival at various levels of drug uptake, and the results for the ortho, para and meta isomers are 1.2x10 4 , 3.9x10 4 and 11.6x10 4 , respectively. These results indicate that the ortho analogue is the most efficient isomer in sensitising cell kill by UVA irradiation due to both the high quantum yield for dehalogenation and the higher cytotoxic efficiency of dehalogenation events

  17. In vitro Cytotoxic Activity of Four Plants Used in Persian Traditional Medicine

    Directory of Open Access Journals (Sweden)

    Fatemeh Zare Shahneh

    2013-08-01

    Full Text Available Purpose: The aim of this study was to investigate in vitro cytotoxic activity of four methanolic crude plant extracts against panel cell lines. Methods: Methanolic extracts were tested for their possible antitumor activity and cytotoxicity using the 3-(4,5-dimetylthiazol-2-yl-2,5- diphenyltetrazolium bromide (MTT assay on six cancer cell lines; non-Hodgkin’s B-cell lymphoma (Raji, human leukemic monocyte lymphoma (U937, human acute myelocytic leukemia (KG-1A, human breast carcinoma (MCF-7 cells, human Prostate Cancer (PC3 and mouse fibrosarcoma (WEHI-164 cell lines and one normal cell line; Human Umbilical Vein Endothelial Cells (HUVEC. Results: All species showed dose dependent inhibition of cell proliferation. IC50 values ranging from 25.66±1.2 to 205.11±1.3 μg/ml. The highest cytotoxic activity Chelidonium majus L> Ferulago Angulata DC> Echinophora platyloba DC> Salvia officinalis L, respectively. Conclusion: all extracts demonstrate promising cytotoxicity activity as a natural resource for future bio-guided fractionation and isolation of potential antitumor agents.

  18. Cytotoxic effect of Erythroxylum suberosum combined with radiotherapy in head and neck cancer cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Macedo, Taysa B.C.; Torres, Hianne M.; Yamamoto-Silva, Fernanda Paula; Silva, Maria Alves G. [Universidade Federal de Goias (UFG), Goiania, GO (Brazil). Escola de Odontologia; Elias, Silvia T.; Silveira, Damaris; Magalhaes, Perola O.; Lofrano-Porto, Adriana; Guerra, Eliete N.S., E-mail: elieteneves@unb.br [Universidade de Brasilia (UnB), Brasilia, DF (Brazil). Faculdade de Ciencias da Saude

    2016-01-15

    The mouth and oropharynx cancer is the 6{sup th} most common type of cancer in the world. The treatment may involve surgery, chemotherapy and radiotherapy. More than 50% of drugs against cancer were isolated from natural sources, such as Catharanthus roseus and epipodophyllotoxin, isolated from Podophyllum. The biggest challenge is to maximize the control of the disease, while minimizing morbidity and toxicity to the surrounding normal tissues. The Erythroxylum suberosum is a common plant in the Brazilian Cerrado biome and is popularly known as 'cabelo-de-negro'. The objective of this study was to evaluate the cytotoxic activity of Erythroxylum suberosum plant extracts of the Brazilian Cerrado biome associated with radiotherapy in human cell lines of oral and hypopharynx carcinomas. Cells were treated with aqueous, ethanolic and hexanic extracts of Erythroxylum suberosum and irradiated at 4 Gy, 6 Gy and 8 Gy. Cytotoxicity was evaluated by MTT assay and the absorbance was measured at 570 nm in a Beckman Counter reader. Cisplatin, standard chemotherapy, was used as positive control. The use of Erythroxylum suberosum extracts showed a possible radiosensitizing effect in vitro for head and neck cancer. The cytotoxicity effect in the cell lines was not selective and it is very similar to the effect of standard chemotherapy. The aqueous extract of Erythroxylum suberosum, combined with radiotherapy was the most cytotoxic extract to oral and hypopharynx carcinomas. (author)

  19. Binase Immobilized on Halloysite Nanotubes Exerts Enhanced Cytotoxicity toward Human Colon Adenocarcinoma Cells

    Directory of Open Access Journals (Sweden)

    Vera Khodzhaeva

    2017-09-01

    Full Text Available Many ribonucleases (RNases are considered as promising tools for antitumor therapy because of their selective cytotoxicity toward cancer cells. Binase, the RNase from Bacillus pumilus, triggers apoptotic response in cancer cells expressing RAS oncogene which is mutated in a large percentage of prevalent and deadly malignancies including colorectal cancer. The specific antitumor effect of binase toward RAS-transformed cells is due to its direct binding of RAS protein and inhibition of downstream signaling. However, the delivery of proteins to the intestine is complicated by their degradation in the digestive tract and subsequent loss of therapeutic activity. Therefore, the search of new systems for effective delivery of therapeutic proteins is an actual task. This study is aimed to the investigation of antitumor effect of binase immobilized on natural halloysite nanotubes (HNTs. Here, we have developed the method of binase immobilization on HNTs and optimized the conditions for the enzyme loading and release (i; we have found the non-toxic concentration of pure HNTs which allows to distinguish HNTs- and binase-induced cytotoxic effects (ii; using dark-field and fluorescent microscopy we have proved the absorption of binase-loaded HNTs on the cell surface (iii and demonstrated that binase-halloysite nanoformulations possessed twice enhanced cytotoxicity toward tumor colon cells as compared to the cytotoxicity of binase itself (iv. The enhanced antitumor activity of biocompatible binase-HNTs complex confirms the advisability of its future development for clinical practice.

  20. Cytotoxic Effects of Fascaplysin against Small Cell Lung Cancer Cell Lines

    Directory of Open Access Journals (Sweden)

    Gerhard Hamilton

    2014-03-01

    Full Text Available Fascaplysin, the natural product of a marine sponge, exhibits anticancer activity against a broad range of tumor cells, presumably through interaction with DNA, and/or as a highly selective cyclin-dependent kinase 4 (CDK4 inhibitor. In this study, cytotoxic activity of fascaplysin against a panel of small cell lung cancer (SCLC cell lines and putative synergism with chemotherapeutics was investigated. SCLC responds to first-line chemotherapy with platinum-based drugs/etoposide, but relapses early with topotecan remaining as the single approved therapeutic agent. Fascaplysin was found to show high cytotoxicity against SCLC cells and to induce cell cycle arrest in G1/0 at lower and S-phase at higher concentrations, respectively. The compound generated reactive oxygen species (ROS and induced apoptotic cell death in the chemoresistant NCI-H417 SCLC cell line. Furthermore, fascaplysin revealed marked synergism with the topoisomerase I-directed camptothecin and 10-hydroxy-camptothecin. The Poly(ADP-ribose-Polymerase 1 (PARP1 inhibitor BYK 204165 antagonized the cytotoxic activity of fascaplysin, pointing to the involvement of DNA repair in response to the anticancer activity of the drug. In conclusion, fascaplysin seems to be suitable for treatment of SCLC, based on high cytotoxic activity through multiple routes of action, affecting topoisomerase I, integrity of DNA and generation of ROS.

  1. Cytotoxic effect of Erythroxylum suberosum combined with radiotherapy in head and neck cancer cell lines

    International Nuclear Information System (INIS)

    Macedo, Taysa B.C.; Torres, Hianne M.; Yamamoto-Silva, Fernanda Paula; Silva, Maria Alves G.; Elias, Silvia T.; Silveira, Damaris; Magalhaes, Perola O.; Lofrano-Porto, Adriana; Guerra, Eliete N.S.

    2016-01-01

    The mouth and oropharynx cancer is the 6 th most common type of cancer in the world. The treatment may involve surgery, chemotherapy and radiotherapy. More than 50% of drugs against cancer were isolated from natural sources, such as Catharanthus roseus and epipodophyllotoxin, isolated from Podophyllum. The biggest challenge is to maximize the control of the disease, while minimizing morbidity and toxicity to the surrounding normal tissues. The Erythroxylum suberosum is a common plant in the Brazilian Cerrado biome and is popularly known as 'cabelo-de-negro'. The objective of this study was to evaluate the cytotoxic activity of Erythroxylum suberosum plant extracts of the Brazilian Cerrado biome associated with radiotherapy in human cell lines of oral and hypopharynx carcinomas. Cells were treated with aqueous, ethanolic and hexanic extracts of Erythroxylum suberosum and irradiated at 4 Gy, 6 Gy and 8 Gy. Cytotoxicity was evaluated by MTT assay and the absorbance was measured at 570 nm in a Beckman Counter reader. Cisplatin, standard chemotherapy, was used as positive control. The use of Erythroxylum suberosum extracts showed a possible radiosensitizing effect in vitro for head and neck cancer. The cytotoxicity effect in the cell lines was not selective and it is very similar to the effect of standard chemotherapy. The aqueous extract of Erythroxylum suberosum, combined with radiotherapy was the most cytotoxic extract to oral and hypopharynx carcinomas. (author)

  2. A Study on Genetic Analysis and Extract Cytotoxicity of Scolopendra subspinipes multilans L. Koch

    Directory of Open Access Journals (Sweden)

    Kim Sung-Nam

    2006-06-01

    Full Text Available Objective : The purpose of this study is to investigate nucleotide sequence and extract cytotoxicity of Scolopendrae corpus. The nature and taste of Scolopendrae corpus is hot, Warm and toxic, and the effect of this is dispelling wind, anti-spasmodic action and detoxication so it has been used for C.V.A, facial palsy, sensory disorder at extremities, wounds and arthritis. Methods : Scolopendrae corpus were collected by locality on the market. They were morphologically classified. Their nucleotide sequence was investigated and compared among them. In addition, the water-alcohol extract cytotoxicity of them was studied by MTT-based cytotoxicity assay. Results : It was shown that the each Scolopendrae corpus by locality is almost identical at genetic result and is identified as Scolopendra subspinipes mutilans L. Koch. Nucleotide sequence of Scolopendra subspinipes mutilans L. Koch in this study will help to discriminate other species of Scolopendrae corpus. The water-alcohol extract of Scolopendra subspinipes mutilans L. Koch did not induce cytotoxicity on Hep G2, L929 cell and peritoneal macrophages. Besides, it did not influence nitrite production of peritoneal macrophages. These results can be used as basic data for genetic discrimination with another species of scolopendrae corpus.

  3. Cytotoxic Effects of Fascaplysin against Small Cell Lung Cancer Cell Lines

    Science.gov (United States)

    Hamilton, Gerhard

    2014-01-01

    Fascaplysin, the natural product of a marine sponge, exhibits anticancer activity against a broad range of tumor cells, presumably through interaction with DNA, and/or as a highly selective cyclin-dependent kinase 4 (CDK4) inhibitor. In this study, cytotoxic activity of fascaplysin against a panel of small cell lung cancer (SCLC) cell lines and putative synergism with chemotherapeutics was investigated. SCLC responds to first-line chemotherapy with platinum-based drugs/etoposide, but relapses early with topotecan remaining as the single approved therapeutic agent. Fascaplysin was found to show high cytotoxicity against SCLC cells and to induce cell cycle arrest in G1/0 at lower and S-phase at higher concentrations, respectively. The compound generated reactive oxygen species (ROS) and induced apoptotic cell death in the chemoresistant NCI-H417 SCLC cell line. Furthermore, fascaplysin revealed marked synergism with the topoisomerase I-directed camptothecin and 10-hydroxy-camptothecin. The Poly(ADP-ribose)-Polymerase 1 (PARP1) inhibitor BYK 204165 antagonized the cytotoxic activity of fascaplysin, pointing to the involvement of DNA repair in response to the anticancer activity of the drug. In conclusion, fascaplysin seems to be suitable for treatment of SCLC, based on high cytotoxic activity through multiple routes of action, affecting topoisomerase I, integrity of DNA and generation of ROS. PMID:24608973

  4. Nanodiamonds act as Trojan horse for intracellular delivery of metal ions to trigger cytotoxicity.

    Science.gov (United States)

    Zhu, Ying; Zhang, Yu; Shi, Guosheng; Yang, Jinrong; Zhang, Jichao; Li, Wenxin; Li, Aiguo; Tai, Renzhong; Fang, Haiping; Fan, Chunhai; Huang, Qing

    2015-02-05

    Nanomaterials hold great promise for applications in the delivery of various molecules with poor cell penetration, yet its potential for delivery of metal ions is rarely considered. Particularly, there is limited insight about the cytotoxicity triggered by nanoparticle-ion interactions. Oxidative stress is one of the major toxicological mechanisms for nanomaterials, and we propose that it may also contribute to nanoparticle-ion complexes induced cytotoxicity. To explore the potential of nanodiamonds (NDs) as vehicles for metal ion delivery, we used a broad range of experimental techniques that aimed at getting a comprehensive assessment of cell responses after exposure of NDs, metal ions, or ND-ion mixture: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, Trypan blue exclusion text, optical microscope observation, synchrotron-based scanning transmission X-ray microscopy (STXM) and micro X-ray fluorescence (μXRF) microscopy, inductively coupled plasma-mass spectrometry (ICP-MS), reactive oxygen species (ROS) assay and transmission electron microscopy (TEM) observation. In addition, theoretical calculation and molecular dynamics (MD) computation were used to illustrate the adsorption properties of different metal ion on NDs as well as release profile of ion from ND-ion complexes at different pH values. The adsorption capacity of NDs for different metal ions was different, and the adsorption for Cu2+ was the most strong among divalent metal ions. These different ND-ion complexes then had different cytotoxicity by influencing the subsequent cellular responses. Detailed investigation of ND-Cu2+ interaction showed that the amount of released Cu2+ from ND-Cu2+ complexes at acidic lysosomal conditions was much higher than that at neutral conditions, leading to the elevation of intracellular ROS level, which triggered cytotoxicity. By theoretical approaches, we demonstrated that the functional carbon surface and cluster structures of NDs made them

  5. A novel multiparametric flow cytometry-based cytotoxicity assay simultaneously immunophenotypes effector cells: Comparisons to a 4 h 51Cr-release assay

    OpenAIRE

    Kim, GG; Donnenberg, VS; Donnenberg, AD; Gooding, W; Whiteside, TL

    2007-01-01

    Natural killer (NK) cell- or T cell-mediated cytotoxicity traditionally is measured in 4-16h 51Cr-release assays (CRA). A new four-color flow cytometry-based cytotoxicity assay (FCC) was developed to simultaneously measure NK cell cytotoxicity and NK cell phenotype (CD3−CD16+CD56+). Target cells, K562 or Daudi, were labeled with Cell Tracker Orange (CTO) prior to the addition of effector cells. Following co-incubation, 7 amino-actinomycin D (7-AAD) was added to measure death of target cells. ...

  6. 'Chocolate' silver nanoparticles: Synthesis, antibacterial activity and cytotoxicity.

    Science.gov (United States)

    Chowdhury, Neelika Roy; MacGregor-Ramiasa, Melanie; Zilm, Peter; Majewski, Peter; Vasilev, Krasimir

    2016-11-15

    Silver nanoparticles (AgNPs) have emerged as a powerful weapon against antibiotic resistant microorganisms. However, most conventional AgNPs syntheses require the use of hazardous chemicals and generate toxic organic waste. Hence, in recent year's, plant derived and biomolecule based synthetics have has gained much attention. Cacao has been used for years for its medicinal benefits and contains a powerful reducing agent - oxalic acid. We hypothesized that, due to the presence of oxalic acid, cacao extract is capable of reducing silver nitrate (AgNO3) to produce AgNPs. In this study, AgNPs were synthesized by using natural cacao extract as a reducing and stabilizing agent. The reaction temperature, time and reactant molarity were varied to optimize the synthesis yield. UV-visible spectroscopy (UV-vis), dynamic light scattering (DLS) and transmission electron microscopy (TEM) characterization demonstrated that the synthesized AgNPs were spherical particles ranging in size from 35 to 42.5nm. The synthesized AgNPs showed significant antibacterial activity against clinically relevant pathogens such as Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Staphylococcus epidermidis. Importantly, these green AgNPs are not cytotoxic to human dermal fibroblasts (HDFs) at concentrations below 32μg/ml. We conclude that cacao-based synthesis is a reproducible and sustainable method for the generation of stable antimicrobial silver nanoparticles with low cytotoxicity to human cells. The AgNPs synthesized in this work have promising properties for applications in the biomedical field. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Flavonoids of Calligonum polygonoides and their cytotoxicity.

    Science.gov (United States)

    Ahmed, Hayam; Moawad, Abeer; Owis, Asmaa; AbouZid, Sameh; Ahmed, Osama

    2016-10-01

    Context Calligonum polygonoides L. subsp. comosum L' Hér. (Polygonaceae), locally known as "arta", is a slow-growing small leafless desert shrub. Objective Isolation, structure elucidation and evaluation of cytotoxic activity of flavonoids from C. polygonoides aerial parts. Materials and methods Flavonoids in the hydroalcoholic extract of the of C. polygonoides were isolated and purified using column chromatography and preparative HPLC. The structures of the isolated flavonoids were elucidated on the basis of spectroscopic data including 2D NMR techniques. The cytotoxic activity of the isolated flavonoids (6.25, 25, 50 and 100 μg/mL) was evaluated against liver HepG2 and breast MCF-7 cancer cell lines using sulphorhodamine-B assay. Results A new flavonoid, kaempferol-3-O-β-D-(6″-n-butyl glucuronide) (1), and 13 known flavonoids, quercetin 3-O-β-D-(6″-n-butyl glucuronide) (2), kaempferol-3-O-β-D-(6″-methyl glucuronide) (3), quercetin-3-O-β-D-(6″-methyl glucuronide) (4), quercetin-3-O-glucuronide (5), kaempferol-3-O-glucuronide (6), quercetin-3-O-α-rhamnopyranoside (7), astragalin (8), quercetin-3-O-glucopyranoside