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Sample records for suppressed cell damage

  1. The suppressive effect of etoposide on recovery from sublethal radiation damage in Chinese hamster V 79 cells

    International Nuclear Information System (INIS)

    Saito, Tsutomu; Shimada, Yuji; Kawamori, Jiro; Kamata, Rikisaburo

    1992-01-01

    The combined effect of radiation and etoposide on the survival of cultured Chinese hamster V 79 cells was investigated. Cells in exponential growth phase were treated with various combinations of radiation and etoposide. The surviving fraction was assessed by colony formation. Etoposide significantly reduced so-called shoulder width, as expressed in Dq (quasithreshold dose), of radiation survival curves. The reduction depended on the increase of etoposide concentrations, although steepening of slopes of exponentially regressing portions of the radiation survival curves was slight. Split dose experiments showed that cells did not recover from sublethal radiation damage in the presence of low concentration of etoposide, although they did recover from sublethal radiation damage under a drug free condition. The results show the suppressive effect of etoposide on recovery from sublethal radiation damage. The effect of a sequential combination of radiation and etoposide was also investigated. The effect was more marked when the interval between radiation and etoposide was shorter regardless of the sequence. (author)

  2. Colored lenses suppress blue light-emitting diode light-induced damage in photoreceptor-derived cells.

    Science.gov (United States)

    Hiromoto, Kaho; Kuse, Yoshiki; Tsuruma, Kazuhiro; Tadokoro, Nobuyuki; Kaneko, Nobuyuki; Shimazawa, Masamitsu; Hara, Hideaki

    2016-03-01

    Blue light-emitting diodes (LEDs) in liquid crystal displays emit high levels of blue light, exposure to which is harmful to the retina. Here, we investigated the protective effects of colored lenses in blue LED light-induced damage to 661W photoreceptor-derived cells. We used eight kinds of colored lenses and one lens that reflects blue light. Moreover, we evaluated the relationship between the protective effects of the lens and the transmittance of lens at 464 nm. Lenses of six colors, except for the SY, PN, and reflective coating lenses, strongly decreased the reduction in cell damage induced by blue LED light exposure. The deep yellow lens showed the most protective effect from all the lenses, but the reflective coating lens and pink lens did not show any effects on photoreceptor-derived cell damage. Moreover, these results were correlated with the lens transmittance of blue LED light (464 nm). These results suggest that lenses of various colors, especially deep yellow lenses, may protect retinal photoreceptor cells from blue LED light in proportion to the transmittance for the wavelength of blue LED and the suppression of reactive oxygen species production and cell damage.

  3. Umbelliferone suppresses radiation induced DNA damage and apoptosis in hematopoietic cells of mice

    International Nuclear Information System (INIS)

    Jayakumar, S.; Bhilwade, H.N.; Chaubey, R.C.

    2012-01-01

    Radiotherapy is one of the major modes of treatment for different types of cancers. But the success of radiotherapy is limited by injury to the normal cells. Protection of the normal cells from radiation damage by radioprotectors can increase therapeutic efficiency. These radioprotectors can also be used during nuclear emergency situations. Umbelliferone (UMB) is a wide spread natural product of the coumarin family. It occurs in many plants from the Apiaceae family. In the present study radioprotective effect of UMB was investigated in vitro and in vivo. Anti genotoxic effect of Umbelliferone was tested by treating the splenic lymphocytes with various doses of UMB (6.5 μM - 50 μM) prior to radiation (6Gy) exposure. After the radiation exposure, extent of DNA damage was assessed by comet assay at 5 mm and two hours after radiation exposure. At both the time points, it was observed that the pretreatment of UMB reduced the radiation induced DNA damage to a significant extent in comparison to radiation control. UMB pretreatment also significantly reduced the radiation induced apoptosis enumerated by propidium iodide staining assay. Results of clonogenic survival assay using intestinal cell line showed that pretreatment with UMB significantly protected against radiation induced loss of colony forming units. To assess the anti genotoxic role of umbelliferone in vivo two different doses of UMB (20 mg/Kg and 40 mg/Kg of body weight) were injected into Swiss mice or with vehicle and exposed to radiation. Thirty minutes after the radiation comet assay was performed in peripheral leukocytes. Frequency of micro nucleated erythrocytes was scored in bone marrow cells. It was observed that UMB alone did not cause any significant increase in DNA damage in comparison to control. Animals which are exposed to radiation alone showed significant increase in DNA damage and micronuclei frequency. But animals treated with UMB prior to the radiation exposure showed significant decrease

  4. Astaxanthin Suppresses MPP+-Induced Oxidative Damage in PC12 Cells through a Sp1/NR1 Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Xiaochun Chen

    2013-03-01

    Full Text Available Objective: To investigate astaxanthin (ATX neuroprotection, and its mechanism, on a 1-methyl-4-phenyl-pyridine ion (MPP+-induced cell model of Parkinson’s disease. Methods: Mature, differentiated PC12 cells treated with MPP+ were used as an in vitro cell model. The MTT assay was used to investigate cell viability after ATX treatment, and western blot analysis was used to observe Sp1 (activated transcription factor 1 and NR1 (NMDA receptor subunit 1 protein expression, real-time PCR was used to monitor Sp1 and NR1 mRNA, and cell immunofluorescence was used to determine the location of Sp1 and NR1 protein and the nuclear translocation of Sp1. Results: PC12 cell viability was significantly reduced by MPP+ treatment. The expression of Sp1 and NR1 mRNA and protein were increased compared with the control (p < 0.01. Following co-treatment with ATX and MPP+, cell viability was significantly increased, and Sp1 and NR1 mRNA and protein were decreased, compared with the MPP+ groups (p < 0.01. In addition, mithracycin A protected PC12 cells from oxidative stress caused by MPP+ by specifically inhibiting the expression of Sp1. Moreover, cell immunofluorescence revealed that ATX could suppress Sp1 nuclear transfer. Conclusion: ATX inhibited oxidative stress induced by MPP+ in PC12 cells, via the SP1/NR1 signaling pathway.

  5. Systemic agonistic anti-CD40 treatment of tumor bearing mice modulates hepatic myeloid suppressive cells and causes immune-mediated liver damage

    Science.gov (United States)

    Medina-Echeverz, José; Ma, Chi; Duffy, Austin; Eggert, Tobias; Hawk, Nga; Kleiner, David E.; Korangy, Firouzeh; Greten, Tim F.

    2015-01-01

    Immune stimulatory monoclonal antibodies are currently evaluated as anti tumor agents. Although overall toxicity appears to be moderate, liver toxicities have been reported and are not completely understood. We studied the effect of systemic CD40 antibody treatment on myeloid cells in spleen and liver. Naïve and tumor-bearing mice were treated systemically with agonistic anti-CD40 antibody. Immune cell subsets in liver and spleen, serum transaminases and liver histologies were analyzed after antibody administration. Nox2−/−, Cd40−/− as well as bone marrow chimeric mice were used to study the mechanism by which agonistic anti-CD40 mediates its effects in vivo. Suppressor function of murine and human tumor-induced myeloid derived suppressive cells was studied upon CD40 ligation. Agonistic CD40 antibody caused liver damage within 24 hours after injection in two unrelated tumor models and mice strains. Using bone marrow chimeras we demonstrated that CD40 antibody-induced hepatitis in tumor-bearing mice was dependent on the presence of CD40-expressing hematopoietic cells. Agonistic CD40 ligation-dependent liver damage was induced by the generation of reactive oxygen species. Furthermore, agonistic CD40 antibody resulted in increased CD80 and CD40 positive liver CD11b+Gr-1+ immature myeloid cells. CD40 ligation on tumor-induced murine and human CD14+HLA-DRlow PBMC from cancer patients reduced their immune suppressor function. Collectively, agonistic CD40 antibody treatment activated tumor-induced, myeloid cells, caused myeloid dependent hepatotoxicity and ameliorated the suppressor function of murine and human MDSC. Collectively, our data suggests that CD40 may mature immunosuppressive myeloid cells and thereby cause liver damage in mice with an accumulation of tumor-induced hepatic MDSC. PMID:25637366

  6. Suppression of PC-1/PrLZ sensitizes prostate cancer cells to ionizing radiation by attenuating DNA damage repair and inducing autophagic cell death.

    Science.gov (United States)

    Shang, Zeng-Fu; Wei, Qiang; Yu, Lan; Huang, Fang; Xiao, Bei-Bei; Wang, Hongtao; Song, Man; Wang, Li; Zhou, Jianguang; Wang, Jian; Li, Shanhu

    2016-09-20

    Radiotherapy is promising and effective for treating prostate cancer but the addition of a tumor cell radiosensitizer would improve therapeutic outcomes. PC-1/PrLZ, a TPD52 protein family member is frequently upregulated in advanced prostate cancer cells and may be a biomarker of aggressive prostate cancer. Therefore, we investigated the potential role of PC-1/PrLZ for increasing radioresistance in human prostate cancer cell lines. Growth curves and survival assays after g-ray irradiation confirmed that depletion of endogenous PC-1/PrLZ significantly increased prostate cancer cell radiosensitivity. Irradiation (IR) increased PC-1/PrLZ expression in a dose- and time-dependent manner and increased radiosensitivity in PC-1/PrLZ-suppressed cells was partially due to decreased DNA double strand break (DBS) repair which was measured with comet and gH2AX foci assays. Furthermore, depletion of PC-1/PrLZ impaired the IR-induced G2/M checkpoint, which has been reported to be correlate with radioresistance in cancer cells. PC-1/PrLZ-deficient cells exhibited higher level of autophagy when compared with control cells. Thus, specific inhibition of PC-1/PrLZ might provide a novel therapeutic strategy for radiosensitizing prostate cancer cells.

  7. Suppression of PC-1/PrLZ sensitizes prostate cancer cells to ionizing radiation by attenuating DNA damage repair and inducing autophagic cell death

    OpenAIRE

    Shang, Zeng-Fu; Wei, Qiang; Yu, Lan; Huang, Fang; Xiao, Bei-Bei; Wang, Hongtao; Song, Man; Wang, Li; Zhou, Jianguang; Wang, Jian; Li, Shanhu

    2016-01-01

    Radiotherapy is promising and effective for treating prostate cancer but the addition of a tumor cell radiosensitizer would improve therapeutic outcomes. PC-1/PrLZ, a TPD52 protein family member is frequently upregulated in advanced prostate cancer cells and may be a biomarker of aggressive prostate cancer. Therefore, we investigated the potential role of PC-1/PrLZ for increasing radioresistance in human prostate cancer cell lines. Growth curves and survival assays after g-ray irradiation con...

  8. Membrane complement regulatory protein reduces the damage of transplanting autologous bone marrow mesenchymal stem cells by suppressing the activation of complement.

    Science.gov (United States)

    Xiao, Kai; Fang, Zhenhua; Gao, Xinfeng; Zhao, Jingjing; Huang, Ruokun; Xie, Ming

    2017-10-01

    There are few studies on the interaction of transplanting autologous bone marrow mesenchymal stem cells (BMSCs) and complement. In order to further explore the effect of complement on BMSCs, BMSCs were obtained from bone marrow of 20 cases clinical patients, and then experimented in vitro. The cytotoxicity of complement on the mesenchymal stem cells in autologous human serum (AHS) was measured by Europium cytotoxicity assay. The complement membrane attack complex (MAC) deposited on the membrane surface was detected by flow cytometry. Finally, the cytotoxicity on BMSCs was measured after mCRPs overexpression or knockdown. We found that more than 90% of cells derived from bone marrow were identified to be mesenchymal stem cells through detection of cell membrane surface markers by flow cytometry. BMSCs harvested from the 20 patients all had cytotoxicity after incubated with AHS, and the cytotoxicity was significant higher than that incubated with complement inactivated autologous human serum (iAHS). Complement attack complex (MAC) could be detected on the BMSCs incubated with AHS, which implied the complement activation. We also found that mCRPs CD55 and CD59 overexpressions can resist the cytotoxicity induced by complement activation, while mCRPs CD55 and CD59 knockdown can enhance the cytotoxicity. Thus, the results indicated that mCRPs could effectively protect BMSCs from attacking by complement by suppressing the activation of complement. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Carnosine attenuates cyclophosphamide-induced bone marrow suppression by reducing oxidative DNA damage

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    Jie Deng

    2018-04-01

    Full Text Available Oxidative DNA damage in bone marrow cells is the main side effect of chemotherapy drugs including cyclophosphamide (CTX. However, not all antioxidants are effective in inhibiting oxidative DNA damage. In this study, we report the beneficial effect of carnosine (β-alanyl-l-histidine, a special antioxidant with acrolein-sequestering ability, on CTX-induced bone marrow cell suppression. Our results show that carnosine treatment (100 and 200 mg/kg, i.p. significantly inhibited the generation of reactive oxygen species (ROS and 8-hydroxy-2′-deoxyguanosine (8-oxo-dG, and decreased chromosomal abnormalities in the bone marrow cells of mice treated with CTX (20 mg/kg, i.v., 24 h. Furthermore, carnosine evidently mitigated CTX-induced G2/M arrest in murine bone marrow cells, accompanied by reduced ratios of p-Chk1/Chk1 and p-p53/p53 as well as decreased p21 expression. In addition, cell apoptosis caused by CTX was also suppressed by carnosine treatment, as assessed by decreased TUNEL-positive cell counts, down-regulated expressions of Bax and Cyt c, and reduced ratios of cleaved Caspase-3/Caspase-3. These results together suggest that carnosine can protect murine bone marrow cells from CTX-induced DNA damage via its antioxidant activity. Keywords: Carnosine, Cyclophosphamide, Oxidative DNA damage, Sister chromatid exchange, Apoptosis, Cell cycle arrest

  10. Nifedipine, a calcium channel blocker, inhibits advanced glycation end product (AGE)-elicited mesangial cell damage by suppressing AGE receptor (RAGE) expression via peroxisome proliferator-activated receptor-gamma activation

    Energy Technology Data Exchange (ETDEWEB)

    Matsui, Takanori [Department of Pathophysiology and Therapeutics of Diabetic Vascular Complications, Kurume University School of Medicine, 67 Asahi-machi, Kurume 830-0011 (Japan); Yamagishi, Sho-ichi, E-mail: shoichi@med.kurume-u.ac.jp [Department of Pathophysiology and Therapeutics of Diabetic Vascular Complications, Kurume University School of Medicine, 67 Asahi-machi, Kurume 830-0011 (Japan); Takeuchi, Masayoshi [Department of Pathophysiological Science, Faculty of Pharmaceutical Science, Hokuriku University, Kanazawa (Japan); Ueda, Seiji; Fukami, Kei; Okuda, Seiya [Department of Medicine, Kurume University School of Medicine, Kurume (Japan)

    2009-07-24

    The interaction between advanced glycation end products (AGE) and their receptor RAGE mediates the progressive alteration in renal architecture and loss of renal function in diabetic nephropathy. Oxidative stress generation and inflammation also play a central role in diabetic nephropathy. This study investigated whether and how nifedipine, a calcium channel blocker (CCB), blocked the AGE-elicited mesangial cell damage in vitro. Nifedipine, but not amlodipine, a control CCB, down-regulated RAGE mRNA levels and subsequently reduced reactive oxygen species (ROS) generation in AGE-exposed mesangial cells. AGE increased mRNA levels of vascular cell adhesion molecule-1 (VCAM-1) and induced monocyte chemoattractant protein-1 (MCP-1) production in mesangial cells, both of which were prevented by the treatment with nifedipine, but not amlodipine. The beneficial effects of nifedipine on AGE-exposed mesangial cells were blocked by the simultaneous treatment of GW9662, an inhibitor of peroxisome proliferator-activated receptor-{gamma} (PPAR-{gamma}). Although nifedipine did not affect expression levels of PPAR-{gamma}, it increased the PPAR-{gamma} transcriptional activity in mesangial cells. Our present study provides a unique beneficial aspect of nifedipine on diabetic nephropathy; it could work as an anti-inflammatory agent against AGE by suppressing RAGE expression in cultured mesangial cells via PPAR-{gamma} activation.

  11. Transient p53 suppression increases reprogramming of human fibroblasts without affecting apoptosis and DNA damage

    DEFF Research Database (Denmark)

    Rasmussen, Mikkel Aabech; Holst, Bjørn; Tümer, Zeynep

    2014-01-01

    The discovery of human-induced pluripotent stem cells (iPSCs) has sparked great interest in the potential treatment of patients with their own in vitro differentiated cells. Recently, knockout of the Tumor Protein 53 (p53) gene was reported to facilitate reprogramming but unfortunately also led...... to genomic instability. Here, we report that transient suppression of p53 during nonintegrative reprogramming of human fibroblasts leads to a significant increase in expression of pluripotency markers and overall number of iPSC colonies, due to downstream suppression of p21, without affecting apoptosis...... and DNA damage. Stable iPSC lines generated with or without p53 suppression showed comparable expression of pluripotency markers and methylation patterns, displayed normal karyotypes, contained between 0 and 5 genomic copy number variations and produced functional neurons in vitro. In conclusion...

  12. IFNγ induces oxidative stress, DNA damage and tumor cell senescence via TGFβ/SMAD signaling-dependent induction of Nox4 and suppression of ANT2

    Czech Academy of Sciences Publication Activity Database

    Hubáčková, Soňa; Kučerová, Alena; Michlits, Georg; Kyjacová, Lenka; Reiniš, Milan; Korolov, Oleksandr; Bartek, Jiří; Hodný, Zdeněk

    2016-01-01

    Roč. 35, č. 10 (2016), s. 1236-1249 ISSN 0950-9232 R&D Projects: GA ČR GA13-17658S; GA MZd NT14461; GA AV ČR(CZ) L200521301 Institutional support: RVO:68378050 Keywords : IFNγ * DNA damage * TGFβ/SMAD signaling * Nox4 Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 7.519, year: 2016

  13. Insecticides suppress natural enemies and increase pest damage in cabbage.

    Science.gov (United States)

    Bommarco, Riccardo; Miranda, Freddy; Bylund, Helena; Björkman, Christer

    2011-06-01

    Intensive use of pesticides is common and increasing despite a growing and historically well documented awareness of the costs and hazards. The benefits from pesticides of increased yields from sufficient pest control may be outweighed by developed resistance in pests and killing of beneficial natural enemies. Other negative effects are human health problems and lower prices because of consumers' desire to buy organic products. Few studies have examined these trade-offs in the field. Here, we demonstrate that Nicaraguan cabbage (Brassica spp.) farmers may suffer economically by using insecticides as they get more damage by the main pest diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), at the same time as they spend economic resources on insecticides. Replicated similarly sized cabbage fields cultivated in a standardized manner were either treated with insecticides according common practice or not treated with insecticides over two seasons. Fields treated with insecticides suffered, compared with nontreated fields, equal or, at least in some periods of the seasons, higher diamondback moth pest attacks. These fields also had increased leaf damage on the harvested cabbage heads. Weight and size of the heads were not affected. The farmers received the same price on the local market irrespective of insecticide use. Rates of parasitized diamondback moth were consistently lower in the treated fields. Negative effects of using insecticides against diamondback moth were found for the density of parasitoids and generalist predatory wasps, and tended to affect spiders negatively. The observed increased leaf damages in insecticide-treated fields may be a combined consequence of insecticide resistance in the pest, and of lower predation and parasitization rates from naturally occurring predators that are suppressed by the insecticide applications. The results indicate biological control as a viable and economic alternative pest management strategy

  14. A Dual Role for Corneal Dendritic Cells in Herpes Simplex Keratitis: Local Suppression of Corneal Damage and Promotion of Systemic Viral Dissemination

    Science.gov (United States)

    Hu, Kai; Harris, Deshea L.; Yamaguchi, Takefumi; von Andrian, Ulrich H.; Hamrah, Pedram

    2015-01-01

    The cornea is the shield to the foreign world and thus, a primary site for peripheral infections. However, transparency and vision are incompatible with inflammation and scarring that may result from infections. Thus, the cornea is required to perform a delicate balance between fighting infections and preserving vision. To date, little is known about the specific role of antigen-presenting cells in viral keratitis. In this study, utilizing an established murine model of primary acute herpes simplex virus (HSV)-1 keratitis, we demonstrate that primary HSV keratitis results in increased conventional dendritic cells (cDCs) and macrophages within 24 hours after infection. Local depletion of cDCs in CD11c-DTR mice by subconjuntival diphtheria toxin injections, led to increased viral proliferation, and influx of inflammatory cells, resulting in increased scarring and clinical keratitis. In addition, while HSV infection resulted in significant corneal nerve destruction, local depletion of cDCs resulted in a much more severe loss of corneal nerves. Further, local cDC depletion resulted in decreased corneal nerve infection, and subsequently decreased and delayed systemic viral transmission in the trigeminal ganglion and draining lymph node, resulting in decreased mortality of mice. In contrast, sham depletion or depletion of macrophages through local injection of clodronate liposomes had neither a significant impact on the cornea, nor an effect on systemic viral transmission. In conclusion, we demonstrate that corneal cDCs may play a primary role in local corneal defense during viral keratitis and preserve vision, at the cost of inducing systemic viral dissemination, leading to increased mortality. PMID:26332302

  15. Suppression of alkali-induced oxidative injury in the cornea by mesenchymal stem cells growing on nanofiber scaffolds and transferred onto the damaged corneal surface

    Czech Academy of Sciences Publication Activity Database

    Čejková, Jitka; Trošan, Peter; Čejka, Čestmír; Lencová, A.; Zajícová, Alena; Javorková, Eliška; Kubinová, Šárka; Syková, Eva; Holáň, Vladimír

    2013-01-01

    Roč. 116, Nov. (2013), s. 312-323 ISSN 0014-4835 R&D Projects: GA ČR GAP304/11/0653; GA ČR(CZ) GAP301/11/1568 Grant - others:GA UK(CZ) 668012; GA MŠk(CZ) SVV 265211 Institutional research plan: CEZ:AV0Z50390512 Institutional support: RVO:68378041 Keywords : corneal oxidative injury * mesenchymal stem cells * nanofiber scaffolds Subject RIV: FF - HEENT, Dentistry Impact factor: 3.017, year: 2013

  16. Pharmacologic suppression of target cell recognition by engineered T cells expressing chimeric T-cell receptors.

    Science.gov (United States)

    Alvarez-Vallina, L; Yañez, R; Blanco, B; Gil, M; Russell, S J

    2000-04-01

    Adoptive therapy with autologous T cells expressing chimeric T-cell receptors (chTCRs) is of potential interest for the treatment of malignancy. To limit possible T-cell-mediated damage to normal tissues that weakly express the targeted tumor antigen (Ag), we have tested a strategy for the suppression of target cell recognition by engineered T cells. Jurkat T cells were transduced with an anti-hapten chTCR tinder the control of a tetracycline-suppressible promoter and were shown to respond to Ag-positive (hapten-coated) but not to Ag-negative target cells. The engineered T cells were then reacted with hapten-coated target cells at different effector to target cell ratios before and after exposure to tetracycline. When the engineered T cells were treated with tetracycline, expression of the chTCR was greatly decreased and recognition of the hapten-coated target cells was completely suppressed. Tetracycline-mediated suppression of target cell recognition by engineered T cells may be a useful strategy to limit the toxicity of the approach to cancer gene therapy.

  17. miR-7-5p overexpression suppresses cell proliferation and promotes apoptosis through inhibiting the ability of DNA damage repair of PARP-1 and BRCA1 in TK6 cells exposed to hydroquinone.

    Science.gov (United States)

    Luo, Hao; Liang, Hairong; Chen, Yuting; Chen, Shaoyun; Xu, Yongchun; Xu, Longmei; Liu, Jiaxian; Zhou, Kairu; Peng, Jucheng; Guo, Guoqiang; Lai, Bei; Song, Li; Yang, Hui; Liu, Linhua; Peng, Jianming; Liu, Zhidong; Tang, Lin; Chen, Wen; Tang, Huanwen

    2018-03-01

    Hydroquinone (HQ), one of the major metabolic products of benzene, is a carcinogen, which induces apoptosis and inhibit proliferation in lymphoma cells. microRNA-7-5p (miR-7-5p), a tumor suppressor, participates in various biological processes including cell proliferation and apoptosis regulation by repressing expression of specific oncogenic target genes. To explore whether miR-7-5p is involved in HQ-induced cell proliferation and apoptosis, we assessed the effect of miR-7-5p overexpression on induction of apoptosis analyzed by FACSCalibur flow cytometer in transfection of TK6 cells with miR-7-5p mimic (TK6- miR-7-5p). We observed an increased apoptosis by 25.43% and decreased proliferation by 28.30% in TK6-miR-7-5p cells compared to those negative control cells (TK6-shNC) in response to HQ treatment. Furthermore, HQ might active the apoptotic pathway via partly downregulation the expression of BRCA1 and PARP-1, followed by p53 activation, in TK6-miR-7-5p cells. In contrast, attenuated p53 and BRCA1 expression was observed in shPARP-1 cells than in NC cells after HQ treatment. Therefore, we conclude that HQ may activate apoptotic signals via inhibiting the tumor suppressive effects of miR-7-5p, which may be mediated partly by upregulating the expression of PARP-1 and BRCA1 in control cells. The increase of miR-7-5p expression further intensified downregulation of PARP-1 and BRCA1 in TK6-miR-7-5p cells, resulting in an increase of apoptosis and proliferation inhibited. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. Electronic cigarette aerosols suppress cellular antioxidant defenses and induce significant oxidative DNA damage.

    Directory of Open Access Journals (Sweden)

    Vengatesh Ganapathy

    Full Text Available Electronic cigarette (EC aerosols contain unique compounds in addition to toxicants and carcinogens traditionally found in tobacco smoke. Studies are warranted to understand the public health risks of ECs.The aim of this study was to determine the genotoxicity and the mechanisms induced by EC aerosol extracts on human oral and lung epithelial cells.Cells were exposed to EC aerosol or mainstream smoke extracts and DNA damage was measured using the primer anchored DNA damage detection assay (q-PADDA and 8-oxo-dG ELISA assay. Cell viability, reactive oxygen species (ROS and total antioxidant capacity (TAC were measured using standard methods. mRNA and protein expression were evaluated by RT-PCR and western blot, respectively.EC aerosol extracts induced DNA damage in a dose-dependent manner, but independently of nicotine concentration. Overall, EC aerosol extracts induced significantly less DNA damage than mainstream smoke extracts, as measured by q-PADDA. However, the levels of oxidative DNA damage, as indicated by the presence of 8-oxo-dG, a highly mutagenic DNA lesion, were similar or slightly higher after exposure to EC aerosol compared to mainstream smoke extracts. Mechanistically, while exposure to EC extracts significantly increased ROS, it decreased TAC as well as the expression of 8-oxoguanine DNA glycosylase (OGG1, an enzyme essential for the removal of oxidative DNA damage.Exposure to EC aerosol extracts suppressed the cellular antioxidant defenses and led to significant DNA damage. These findings emphasize the urgent need to investigate the potential long-term cancer risk of exposure to EC aerosol for vapers and the general public.

  19. Melatonin attenuated brain death tissue extract-induced cardiac damage by suppressing DAMP signaling.

    Science.gov (United States)

    Sung, Pei-Hsun; Lee, Fan-Yen; Lin, Ling-Chun; Chen, Kuan-Hung; Lin, Hung-Sheng; Shao, Pei-Lin; Li, Yi-Chen; Chen, Yi-Ling; Lin, Kun-Chen; Yuen, Chun-Man; Chang, Hsueh-Wen; Lee, Mel S; Yip, Hon-Kan

    2018-01-09

    We tested the hypothesis that melatonin prevents brain death (BD) tissue extract (BDEX)-induced cardiac damage by suppressing inflammatory damage-associated molecular pattern (DAMP) signaling in rats. Six hours after BD induction, levels of a DAMP component (HMGB1) and inflammatory markers (TLR-2, TLR-4, MYD88, IκB, NF-κB, IL-1β, IFN-γ, TNF-α and IL-6) were higher in brain tissue from BD animals than controls. Levels of HMGB1 and inflammatory markers were higher in BDEX-treated H9C2 cardiac myoblasts than in cells treated with healthy brain tissue extract. These increases were attenuated by melatonin but re-induced with luzindole (all P DAMP inflammatory axis.

  20. Cohesin Is limiting for the suppression of DNA damage-induced recombination between homologous chromosomes.

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    Shay Covo

    2010-07-01

    Full Text Available Double-strand break (DSB repair through homologous recombination (HR is an evolutionarily conserved process that is generally error-free. The risk to genome stability posed by nonallelic recombination or loss-of-heterozygosity could be reduced by confining HR to sister chromatids, thereby preventing recombination between homologous chromosomes. Here we show that the sister chromatid cohesion complex (cohesin is a limiting factor in the control of DSB repair and genome stability and that it suppresses DNA damage-induced interactions between homologues. We developed a gene dosage system in tetraploid yeast to address limitations on various essential components in DSB repair and HR. Unlike RAD50 and RAD51, which play a direct role in HR, a 4-fold reduction in the number of essential MCD1 sister chromatid cohesion subunit genes affected survival of gamma-irradiated G(2/M cells. The decreased survival reflected a reduction in DSB repair. Importantly, HR between homologous chromosomes was strongly increased by ionizing radiation in G(2/M cells with a single copy of MCD1 or SMC3 even at radiation doses where survival was high and DSB repair was efficient. The increased recombination also extended to nonlethal doses of UV, which did not induce DSBs. The DNA damage-induced recombinants in G(2/M cells included crossovers. Thus, the cohesin complex has a dual role in protecting chromosome integrity: it promotes DSB repair and recombination between sister chromatids, and it suppresses damage-induced recombination between homologues. The effects of limited amounts of Mcd1and Smc3 indicate that small changes in cohesin levels may increase the risk of genome instability, which may lead to genetic diseases and cancer.

  1. Drosophila clueless is highly expressed in larval neuroblasts, affects mitochondrial localization and suppresses mitochondrial oxidative damage.

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    Aditya Sen

    Full Text Available Mitochondria are critical for neuronal function due to the high demand of ATP in these cell types. During Drosophila development, neuroblasts in the larval brain divide asymmetrically to populate the adult central nervous system. While many of the proteins responsible for maintaining neuroblast cell fate and asymmetric cell divisions are known, little is know about the role of metabolism and mitochondria in neuroblast division and maintenance. The gene clueless (clu has been previously shown to be important for mitochondrial function. clu mutant adults have severely shortened lifespans and are highly uncoordinated. Part of their lack of coordination is due to defects in muscle, however, in this study we have identified high levels of Clu expression in larval neuroblasts and other regions of the dividing larval brain. We show while mitochondria in clu mutant neuroblasts are mislocalized during the cell cycle, surprisingly, overall brain morphology appears to be normal. This is explained by our observation that clu mutant larvae have normal levels of ATP and do not suffer oxidative damage, in sharp contrast to clu mutant adults. Mutations in two other genes encoding mitochondrial proteins, technical knockout and stress sensitive B, do not cause neuroblast mitochondrial mislocalization, even though technical knockout mutant larvae suffer oxidative damage. These results suggest Clu functions upstream of electron transport and oxidative phosphorylation, has a role in suppressing oxidative damage in the cell, and that lack of Clu's specific function causes mitochondria to mislocalize. These results also support the previous observation that larval development relies on aerobic glycolysis, rather than oxidative phosphorylation. Thus Clu's role in mitochondrial function is not critical during larval development, but is important for pupae and adults.

  2. Topical calcitriol protects from UV-induced genetic damage but suppresses cutaneous immunity in humans.

    Science.gov (United States)

    Damian, Diona L; Kim, Young Jin; Dixon, Katie M; Halliday, Gary M; Javeri, Arash; Mason, Rebecca S

    2010-08-01

    Calcitriol, the biologically active form of vitamin D, has been reported to cause both suppressive and protective immune effects in mice. Its immune effects in vivo in humans are unclear. We investigated the in vivo effects of topical calcitriol on minimal erythema dose and skin immune responses in healthy volunteers. We found that calcitriol did not protect from ultraviolet (UV)-induced erythema (sunburn) when applied either 24 h before or immediately after irradiation, although it decreased the density of sunburn cells and thymine dimers seen on biopsy when applied 24 h before and again immediately after irradiation. Using the Mantoux reaction as a model of skin immunity, we found that topical calcitriol applied at high total doses reduced the Mantoux responses of nearby untreated, unirradiated skin, suggesting a para-local or systemic immunosuppressive effect not observed with lower calcitriol doses. We then measured UV-induced suppression of Mantoux reactions at vehicle-treated sites and sites treated with low-dose calcitriol, and found that calcitriol neither reduced nor enhanced UV-induced immunosuppression. Despite calcitriol reducing UV-induced DNA damage, which should protect the immune system, it has immunosuppressive effects in our model which may help to explain the efficacy of analogues such as calcipotriol in the treatment of psoriasis.

  3. Repair of radiation damage in mammalian cells

    International Nuclear Information System (INIS)

    Setlow, R.B.

    1981-01-01

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

  4. p53-Dependent suppression of genome instability in germ cells

    Energy Technology Data Exchange (ETDEWEB)

    Otozai, Shinji [Department of Otorhinolaryngology and Head and Neck Surgery, Osaka University School of Medicine, Osaka 565-0871 (Japan); Ishikawa-Fujiwara, Tomoko [Department of Radiation Biology and Medical Genetics, Graduate School of Medicine, Osaka University, B4, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan); Oda, Shoji [Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8562 (Japan); Kamei, Yasuhiro [Department of Radiation Biology and Medical Genetics, Graduate School of Medicine, Osaka University, B4, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan); Ryo, Haruko [Nomura Project, National Institute of Biomedical Innovation, Osaka 565-0085 (Japan); Sato, Ayuko [Department of Pathology, Hyogo College of Medicine, Hyogo 663-8501 (Japan); Nomura, Taisei [Nomura Project, National Institute of Biomedical Innovation, Osaka 565-0085 (Japan); Mitani, Hiroshi [Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8562 (Japan); Tsujimura, Tohru [Department of Pathology, Hyogo College of Medicine, Hyogo 663-8501 (Japan); Inohara, Hidenori [Department of Otorhinolaryngology and Head and Neck Surgery, Osaka University School of Medicine, Osaka 565-0871 (Japan); Todo, Takeshi, E-mail: todo@radbio.med.osaka-u.ac.jp [Department of Radiation Biology and Medical Genetics, Graduate School of Medicine, Osaka University, B4, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan)

    2014-02-15

    Highlights: • Radiation-induced microsatellite instability (MSI) was investigated in medaka fish. • msh2{sup −/−} fish had a high frequency of spontaneous MSI. • p53{sup −/−} fish had a high frequency of radiation-induced MSI. • p53 and msh2 suppress MSI by different pathways: mismatch removal and apoptosis. - Abstract: Radiation increases mutation frequencies at tandem repeat loci. Germline mutations in γ-ray-irradiated medaka fish (Oryzias latipes) were studied, focusing on the microsatellite loci. Mismatch-repair genes suppress microsatellite mutation by directly removing altered sequences at the nucleotide level, whereas the p53 gene suppresses genetic alterations by eliminating damaged cells. The contribution of these two defense mechanisms to radiation-induced microsatellite instability was addressed. The spontaneous mutation frequency was significantly higher in msh2{sup −/−} males than in wild-type fish, whereas there was no difference in the frequency of radiation-induced mutations between msh2{sup −/−} and wild-type fish. By contrast, irradiated p53{sup −/−} fish exhibited markedly increased mutation frequencies, whereas their spontaneous mutation frequency was the same as that of wild-type fish. In the spermatogonia of the testis, radiation induced a high level of apoptosis both in wild-type and msh2{sup −/−} fish, but negligible levels in p53{sup −/−} fish. The results demonstrate that the msh2 and p53 genes protect genome integrity against spontaneous and radiation-induced mutation by two different pathways: direct removal of mismatches and elimination of damaged cells.

  5. Gallium arsenide solar cell radiation damage study

    Science.gov (United States)

    Maurer, R. H.; Herbert, G. A.; Kinnison, J. D.; Meulenberg, A.

    1989-01-01

    A thorough analysis has been made of electron- and proton- damaged GaAs solar cells suitable for use in space. It is found that, although some electrical parametric data and spectral response data are quite similar, the type of damage due to the two types of radiation is different. An I-V analysis model shows that electrons damage the bulk of the cell and its currents relatively more, while protons damage the junction of the cell and its voltages more. It is suggested that multiple defects due to protons in a strong field region such as a p/n junction cause the greater degradation in cell voltage, whereas the individual point defects in the quasi-neutral minority-carrier-diffusion regions due to electrons cause the greater degradation in cell current and spectral response.

  6. Apamin suppresses biliary fibrosis and activation of hepatic stellate cells.

    Science.gov (United States)

    Kim, Jung-Yeon; An, Hyun-Jin; Kim, Woon-Hae; Park, Yoon-Yub; Park, Kyung Duck; Park, Kwan-Kyu

    2017-05-01

    Cholestatic liver disease is characterized by the progressive destruction of biliary epithelial cells (BECs) followed by fibrosis, cirrhosis and liver failure. Activated hepatic stellate cells (HSCs) and portal fibroblasts are the major cellular effectors of enhanced collagen deposition in biliary fibrosis. Apamin, an 18 amino acid peptide neurotoxin found in apitoxin (bee venom), is known to block Ca2+-activated K+ channels and prevent carbon tetrachloride-induced liver fibrosis. In the present study, we aimed to ascertain whether apamin inhibits biliary fibrosis and the proliferation of HSCs. Cholestatic liver fibrosis was established in mouse models with 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) feeding. Cellular assays were performed on HSC-T6 cells (rat immortalized HSCs). DDC feeding led to increased hepatic damage and proinflammtory cytokine levels. Notably, apamin treatment resulted in decreased liver injury and proinflammatory cytokine levels. Moreover, apamin suppressed the deposition of collagen, proliferation of BECs and expression of fibrogenic genes in the DDC-fed mice. In HSCs, apamin suppressed activation of HSCs by inhibiting the Smad signaling pathway. These data suggest that apamin may be a potential therapeutic target in cholestatic liver disease.

  7. Impact damage resistance and damage suppression properties of shape memory alloys in hybrid composites—a review

    International Nuclear Information System (INIS)

    Angioni, S L; Meo, M; Foreman, A

    2011-01-01

    Composite materials are known to have a poor resistance to through-the-thickness impact loading. There are various methods for improving their impact damage tolerance, such as fiber toughening, matrix toughening, interface toughening, through-the-thickness reinforcements, and selective interlayers and hybrids. Hybrid composites with improved impact resistance are particularly useful in military and commercial civil applications. Hybridizing composites using shape memory alloys (SMA) is one solution since SMA materials can absorb the energy of the impact through superelastic deformation or recovery stress, reducing the effects of the impact on the composite structure. The SMA material may be embedded in the hybrid composites (SMAHC) in many different forms and also the characteristics of the fiber reinforcements may vary, such as SMA wires in woven laminates or SMA foils in unidirectional laminates, only to cite two examples. We will review the state of the art of SMAHC for the purpose of damage suppression. Both the active and passive damage suppression mechanisms will be considered. (topical review)

  8. Human renal tubular epithelial cells suppress alloreactive T cell proliferation.

    Science.gov (United States)

    Demmers, M W H J; Korevaar, S S; Roemeling-van Rhijn, M; van den Bosch, T P P; Hoogduijn, M J; Betjes, M G H; Weimar, W; Baan, C C; Rowshani, A T

    2015-03-01

    Renal tubular epithelial cells (TECs) are one of the main targets of alloreactive T cells during acute rejection. We hypothesize that TECs modulate the outcome of alloimmunity by executing immunosuppressive effects in order to dampen the local inflammation. We studied whether TECs possess immunosuppressive capacities and if indoleamine 2,3-dioxygenase (IDO) might play a role in suppressing T cell alloreactivity. Next, we studied the role of programmed death ligand 1 (PD-L1) and intercellular adhesion molecule-1 (ICAM-1 with regard to TEC-related immunomodulatory effects. CD3/CD28 and alloactivated peripheral blood mononuclear cells were co-cultured with activated TECs. We analysed CD4(+) and CD8(+) T cell proliferation and apoptosis in the absence or presence of IDO inhibitor 1-methyl-L-tryptophan (1-L-MT), anti-PD-L1 and anti-ICAM-1. Further, we examined whether inhibition of T cell proliferation was cell-cell contact-dependent. We found that TECs dose-dependently inhibited CD4(+) and CD8(+) T cell proliferation (Pcell proliferation was only partially restored or failed to restore using 1-L-MT. Activated TECs increased early and late apoptosis of proliferating CD4(+) and CD8(+) T cells; only CD4(+) T cell apoptosis was statistically affected by 1-L-MT. Transwell experiments revealed that TEC-mediated immunosuppression is cell-cell contact-dependent. We found that anti-ICAM-1 affected only CD4(+) T cell apoptosis and not T cell proliferation. Our data show that TECs suppress both CD4(+) and CD8(+) T cell proliferation contact dependently. Interestingly, inhibition of proliferation and enhancement of apoptosis of T cell subsets is differentially regulated by indoleamine 2,3-dioxygenase and ICAM-1, with no evidence for the involvement of PD-L1 in our system. © 2014 British Society for Immunology.

  9. Radiation damage of gallium arsenide production cells

    Science.gov (United States)

    Mardesich, N.; Joslin, D.; Garlick, J.; Lillington, D.; Gillanders, M.; Cavicchi, B.; Scott-Monck, J.; Kachare, R.; Anspaugh, B.

    1987-01-01

    High efficiency liquid phase epitaxy (LPE) gallium arsenide cells were irradiated with 1 Mev electrons up to fluences of 1 times 10 to the 16th power cm-2. Measurements of spectral response and dark and illuminated I-V data were made at each fluence and then, using computer codes, the experimental data was fitted to gallium arsenide cell models. In this way it was possible to determine the extent of the damage, and hence damage coefficients in both the emitter and base of the cell.

  10. Low-level light emitting diode (LED) therapy suppresses inflammasome-mediated brain damage in experimental ischemic stroke.

    Science.gov (United States)

    Lee, Hae In; Lee, Sae-Won; Kim, Nam Gyun; Park, Kyoung-Jun; Choi, Byung Tae; Shin, Yong-Il; Shin, Hwa Kyoung

    2017-11-01

    Use of photostimulation including low-level light emitting diode (LED) therapy has broadened greatly in recent years because it is compact, portable, and easy to use. Here, the effects of photostimulation by LED (610 nm) therapy on ischemic brain damage was investigated in mice in which treatment started after a stroke in a clinically relevant setting. The mice underwent LED therapy (20 min) twice a day for 3 days, commencing at 4 hours post-ischemia. LED therapy group generated a significantly smaller infarct size and improvements in neurological function based on neurologic test score. LED therapy profoundly reduced neuroinflammatory responses including neutrophil infiltration and microglia activation in the ischemic cortex. LED therapy also decreased cell death and attenuated the NLRP3 inflammasome, in accordance with down-regulation of pro-inflammatory cytokines IL-1β and IL-18 in the ischemic brain. Moreover, the mice with post-ischemic LED therapy showed suppressed TLR-2 levels, MAPK signaling and NF-kB activation. These findings suggest that by suppressing the inflammasome, LED therapy can attenuate neuroinflammatory responses and tissue damage following ischemic stroke. Therapeutic interventions targeting the inflammasome via photostimulation with LED may be a novel approach to ameliorate brain injury following ischemic stroke. Effect of post-ischemic low-level light emitting diode therapy (LED-T) on infarct reduction was mediated by inflammasome suppression. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. An Overview of Crop Hail Damage and Evaluation of Hail Suppression Efficiency in Bulgaria.

    Science.gov (United States)

    Simeonov, Petio

    1996-09-01

    The space time distribution of the crop hail loss-to-risk ratio over the whole. Bulgarian territory has been ascertained using the rank approach. The relationships between hailfall characteristics (sizes and kinetic energy) and the percentage of the crop damage for wheat, corn, and vines were obtained using field observations and hailpad data. A physical statistical method for evaluating the changes in damaged crop areas was tested over a 5000-km2 target area (numbers for three hail suppression ranges). Using a regression equation (worked out for 120 nonseeded days) for evaluation of the damaged area changes, reductions in damaged area of 34% 48% were obtained for 7 and 9 years of heavy hail. The magnitude of the reduction is comparable with the one obtained using double-mass ratio and bivariate test of loss-to-risk data in the control and target areas. Similar results were obtained in other hail suppression projects in France, North Dakota, and Greece. A short overview of the physical effects of cloud seeding is presented. The physical-statistical approach for severe hailstorms, based on the regression between thermodynamical indices of instability and damaged areas, shows promise as a perspective to evaluate the efficiency of the seeding operations in problematic cases.

  12. Chromatin Dynamics in Genome Stability: Roles in Suppressing Endogenous DNA Damage and Facilitating DNA Repair

    Science.gov (United States)

    Nair, Nidhi; Shoaib, Muhammad

    2017-01-01

    Genomic DNA is compacted into chromatin through packaging with histone and non-histone proteins. Importantly, DNA accessibility is dynamically regulated to ensure genome stability. This is exemplified in the response to DNA damage where chromatin relaxation near genomic lesions serves to promote access of relevant enzymes to specific DNA regions for signaling and repair. Furthermore, recent data highlight genome maintenance roles of chromatin through the regulation of endogenous DNA-templated processes including transcription and replication. Here, we review research that shows the importance of chromatin structure regulation in maintaining genome integrity by multiple mechanisms including facilitating DNA repair and directly suppressing endogenous DNA damage. PMID:28698521

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

    African Journals Online (AJOL)

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

  14. Metformin (dimethyl-biguanide induced DNA damage in mammalian cells

    Directory of Open Access Journals (Sweden)

    Rubem R. Amador

    2012-01-01

    Full Text Available Metformin (dimethyl-biguanide is an insulin-sensitizing agent that lowers fasting plasma-insulin concentration, wherefore it's wide use for patients with a variety of insulin-resistant and prediabetic states, including impaired glucose tolerance. During pregnancy it is a further resource for reducing first-trimester pregnancy loss in women with the polycystic ovary syndrome. We tested metformin genotoxicity in cells of Chinese hamster ovary, CHO-K1 (chromosome aberrations; comet assays and in mice (micronucleus assays. Concentrations of 114.4 µg/mL and 572 µg/mL were used in in vitro tests, and 95.4 mg/kg, 190.8 mg/kg and 333.9 mg/kg in assaying. Although the in vitro tests revealed no chromosome aberrations in metaphase cells, DNA damage was detected by comet assaying after 24 h of incubation at both concentrations. The frequency of DNA damage was higher at concentrations of 114.4 µg/mL. Furthermore, although mortality was not observed in in vitro tests, the highest dose of metformin suppressed bone marrow cells. However, no statistically significant differences were noted in micronuclei frequencies between treatments. In vitro results indicate that chronic metformin exposure may be potentially genotoxic. Thus, pregnant woman undergoing treatment with metformin should be properly evaluated beforehand, as regards vulnerability to DNA damage.

  15. NER enzymes maintain genome integrity and suppress homologous recombination in the absence of exogenously induced DNA damage in Pseudomonas putida.

    Science.gov (United States)

    Sidorenko, Julia; Ukkivi, Kärt; Kivisaar, Maia

    2015-01-01

    affected by the UvrA homologue UvrA2 neither in NER-proficient bacteria nor in the absence of UvrA, suggesting a minor role of UvrA2 in NER. Thus, we conclude that NER functions are important also without exogenously induced DNA damage in P. putida and both transcription-coupled and global genome NER act to suppress HR in growing cells, whereas UvrA and UvrB are involved in the maintenance of the genome integrity also in stationary-phase cells. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Knockdown of p53 suppresses Nanog expression in embryonic stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Abdelalim, Essam Mohamed, E-mail: emohamed@qf.org.qa [Qatar Biomedical Research Institute, Qatar Foundation, Doha 5825 (Qatar); Molecular Neuroscience Research Center, Shiga University of Medical Science, Setatsukinowa-cho, Otsu, Shiga 520-2192 (Japan); Department of Cytology and Histology, Faculty of Veterinary Medicine, Suez Canal University, Ismailia (Egypt); Tooyama, Ikuo [Molecular Neuroscience Research Center, Shiga University of Medical Science, Setatsukinowa-cho, Otsu, Shiga 520-2192 (Japan)

    2014-01-10

    Highlights: •We investigate the role of p53 in ESCs in the absence of DNA damage. •p53 knockdown suppresses ESC proliferation. •p53 knockdown downregulates Nanog expression. •p53 is essential for mouse ESC self-renewal. -- Abstract: Mouse embryonic stem cells (ESCs) express high levels of cytoplasmic p53. Exposure of mouse ESCs to DNA damage leads to activation of p53, inducing Nanog suppression. In contrast to earlier studies, we recently reported that chemical inhibition of p53 suppresses ESC proliferation. Here, we confirm that p53 signaling is involved in the maintenance of mouse ESC self-renewal. RNA interference-mediated knockdown of p53 induced downregulation of p21 and defects in ESC proliferation. Furthermore, p53 knockdown resulted in a significant downregulation in Nanog expression at 24 and 48 h post-transfection. p53 knockdown also caused a reduction in Oct4 expression at 48 h post-transfection. Conversely, exposure of ESCs to DNA damage caused a higher reduction of Nanog expression in control siRNA-treated cells than in p53 siRNA-treated cells. These data show that in the absence of DNA damage, p53 is required for the maintenance of mouse ESC self-renewal by regulating Nanog expression.

  17. Altered Gene Expressions and Cytogenetic Repair Efficiency in Cells with Suppressed Expression of XPA after Proton Exposure

    Science.gov (United States)

    Zhang, Ye; Rohde, Larry H.; Gridley, Daila S.; Mehta, Satish K.; Pierson, Duane L.; Wu, Honglu

    2009-01-01

    Cellular responses to damages from ionizing radiation (IR) exposure are influenced not only by the genes involved in DNA double strand break (DSB) repair, but also by non- DSB repair genes. We demonstrated previously that suppressed expression of several non-DSB repair genes, such as XPA, elevated IR-induced cytogenetic damages. In the present study, we exposed human fibroblasts that were treated with control or XPA targeting siRNA to 250 MeV protons (0 to 4 Gy), and analyzed chromosome aberrations and expressions of genes involved in DNA repair. As expected, after proton irradiation, cells with suppressed expression of XPA showed a significantly elevated frequency of chromosome aberrations compared with control siRNA treated (CS) cells. Protons caused more severe DNA damages in XPA knock-down cells, as 36% cells contained multiple aberrations compared to 25% in CS cells after 4Gy proton irradiation. Comparison of gene expressions using the real-time PCR array technique revealed that expressions of p53 and its regulated genes in irradiated XPA suppressed cells were altered similarly as in CS cells, suggesting that the impairment of IR induced DNA repair in XPA suppressed cells is p53-independent. Except for XPA, which was more than 2 fold down regulated in XPA suppressed cells, several other DNA damage sensing and repair genes (GTSE1, RBBP8, RAD51, UNG and XRCC2) were shown a more than 1.5 fold difference between XPA knock-down cells and CS cells after proton exposure. The possible involvement of these genes in the impairment of DNA repair in XPA suppressed cells will be further investigated.

  18. Salidroside Suppresses HUVECs Cell Injury Induced by Oxidative Stress through Activating the Nrf2 Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Yao Zhu

    2016-08-01

    Full Text Available Oxidative stress plays an important role in the pathogenesis of cardiovascular diseases. Salidroside (SAL, one of the main effective constituents of Rhodiola rosea, has been reported to suppress oxidative stress-induced cardiomyocyte injury and necrosis by promoting transcription of nuclear factor E2-related factor 2 (Nrf2-regulated genes such as heme oxygenase-1 (HO-1 and NAD(PH dehydrogenase (quinone1 (NQO1. However, it has not been indicated whether SAL might ameliorate endothelial injury induced by oxidative stress. Here, our study demonstrated that SAL might suppress HUVEC cell injury induced by oxidative stress through activating the Nrf2 signaling pathway. The results of our study indicated that SAL decreased the levels of intercellular reactive oxygen species (ROS and malondialdehyde (MDA, and improved the activities of superoxide dismutase (SOD and catalase (CAT, resulting in protective effects against oxidative stress-induced cell damage in HUVECs. It suppressed oxidative stress damage by inducing Nrf2 nuclear translocation and activating the expression of Nrf2-regulated antioxidant enzyme genes such as HO-1 and NQO1 in HUVECs. Knockdown of Nrf2 with siRNA abolished the cytoprotective effects against oxidative stress, decreased the expression of Nrf2, HO-1, and NQO1, and inhibited the nucleus translocation of Nrf2 in HUVECs. This study is the first to demonstrate that SAL suppresses HUVECs cell injury induced by oxidative stress through activating the Nrf2 signaling pathway.

  19. Mechanisms of dealing with DNA damage in terminally differentiated cells

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-03-01

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

  20. Mechanisms of dealing with DNA damage in terminally differentiated cells

    International Nuclear Information System (INIS)

    Fortini, P.; Dogliotti, E.

    2010-01-01

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

  1. Targeted elimination of senescent Ras-transformed cells by suppression of MEK/ERK pathway.

    Science.gov (United States)

    Kochetkova, Elena Y; Blinova, Galina I; Bystrova, Olga A; Martynova, Marina G; Pospelov, Valery A; Pospelova, Tatiana V

    2017-11-14

    The Ras-Raf-MEK-ERK pathway plays a central role in tumorigenesis and is a target for anticancer therapy. The successful strategy based on the activation of cell death in Ras-expressing cells is associated with the suppression of kinases involved in Ras pathway. However, activation of cytoprotective autophagy overcomes antiproliferative effect of the inhibitors and develops drug resistance. We studied whether cellular senescence induced by HDAC inhibitor sodium butyrate in E1a+cHa-Ras -transformed rat embryo fibroblasts (ERas) and A549 human Ki-Ras mutated lung adenocarcinoma cells would enhance the tumor suppressor effect of MEK/ERK inhibition. Treatment of control ERas cells with PD0325901 for 24 h results in mitochondria damage and apoptotic death of a part of cellular population. However, the activation of AMPK-dependent autophagy overcomes pro-apoptotic effects of MEK/ERK inhibitor and results in restoration of the mitochondria and rescue of viability. Senescent ERas cells do not develop cytoprotective autophagy upon inhibition of MEK/ERK pathway due to spatial dissociation of lysosomes and autophagosomes in the senescent cells. Senescent cells are unable to form the autophagolysosomes and to remove the damaged mitochondria resulting in apoptotic death. Our data show that suppression of MEK/ERK pathway in senescent cells provides a new strategy for elimination of Ras-expressing cells.

  2. Suppression of autophagy exacerbates Mefloquine-mediated cell death.

    Science.gov (United States)

    Shin, Ji Hyun; Park, So Jung; Jo, Yoon Kyung; Kim, Eun Sung; Kang, Hee; Park, Ji-Ho; Lee, Eunjoo H; Cho, Dong-Hyung

    2012-05-02

    Mefloquine is an effective treatment drug for malaria. However, it can cause several adverse side effects, and the precise mechanism associated with the adverse neurological effects of Mefloquine is not clearly understood. In this study, we investigated the effect of Mefloquine on autophagy in neuroblastoma cells. Mefloquine treatment highly induced the formation of autophagosomes and the conversion of LC3I into LC3II. Moreover, Mefloquine-induced autophagy was efficiently suppressed by an autophagy inhibitor and by down regulation of ATG6. The autophagy was also completely blocked in ATG5 deficient mouse embryonic fibroblast cells. Moreover, suppression of autophagy significantly intensified Mefloquine-mediated cytotoxicity in SH-SY5Y cells. Our findings suggest that suppression of autophagy may exacerbate Mefloquine toxicity in neuroblastoma cells. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  3. The p53 inhibitor, pifithrin-{alpha}, suppresses self-renewal of embryonic stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Abdelalim, Essam Mohamed, E-mail: essam_abdelalim@yahoo.com [Molecular Neuroscience Research Center, Shiga University of Medical Science, Setatsukinowa-cho, Otsu, Shiga 520-2192 (Japan); Department of Cytology and Histology, Faculty of Veterinary Medicine, Suez Canal University, Ismailia 41522 (Egypt); Tooyama, Ikuo [Molecular Neuroscience Research Center, Shiga University of Medical Science, Setatsukinowa-cho, Otsu, Shiga 520-2192 (Japan)

    2012-04-13

    Highlights: Black-Right-Pointing-Pointer We determine the role of p53 in ES cells under unstressful conditions. Black-Right-Pointing-Pointer PFT-{alpha} suppresses ES cell proliferation. Black-Right-Pointing-Pointer PFT-{alpha} induces ES cell cycle arrest. Black-Right-Pointing-Pointer PFT-{alpha} downregulates Nanog and cyclin D1. -- Abstract: Recent studies have reported the role of p53 in suppressing the pluripotency of embryonic stem (ES) cells after DNA damage and blocking the reprogramming of somatic cells into induced pluripotent stem (iPS) cells. However, to date no evidence has been presented to support the function of p53 in unstressed ES cells. In this study, we investigated the effect of pifithrin (PFT)-{alpha}, an inhibitor of p53-dependent transcriptional activation, on self-renewal of ES cells. Our results revealed that treatment of ES cells with PFT-{alpha} resulted in the inhibition of ES cell propagation in a dose-dependent manner, as indicated by a marked reduction in the cell number and colony size. Also, PFT-{alpha} caused a cell cycle arrest and significant reduction in DNA synthesis. In addition, inhibition of p53 activity reduced the expression levels of cyclin D1 and Nanog. These findings indicate that p53 pathway in ES cells rather than acting as an inactive gene, is required for ES cell proliferation and self-renewal under unstressful conditions.

  4. The p53 inhibitor, pifithrin-α, suppresses self-renewal of embryonic stem cells

    International Nuclear Information System (INIS)

    Abdelalim, Essam Mohamed; Tooyama, Ikuo

    2012-01-01

    Highlights: ► We determine the role of p53 in ES cells under unstressful conditions. ► PFT-α suppresses ES cell proliferation. ► PFT-α induces ES cell cycle arrest. ► PFT-α downregulates Nanog and cyclin D1. -- Abstract: Recent studies have reported the role of p53 in suppressing the pluripotency of embryonic stem (ES) cells after DNA damage and blocking the reprogramming of somatic cells into induced pluripotent stem (iPS) cells. However, to date no evidence has been presented to support the function of p53 in unstressed ES cells. In this study, we investigated the effect of pifithrin (PFT)-α, an inhibitor of p53-dependent transcriptional activation, on self-renewal of ES cells. Our results revealed that treatment of ES cells with PFT-α resulted in the inhibition of ES cell propagation in a dose-dependent manner, as indicated by a marked reduction in the cell number and colony size. Also, PFT-α caused a cell cycle arrest and significant reduction in DNA synthesis. In addition, inhibition of p53 activity reduced the expression levels of cyclin D1 and Nanog. These findings indicate that p53 pathway in ES cells rather than acting as an inactive gene, is required for ES cell proliferation and self-renewal under unstressful conditions.

  5. Cell damage by bilirubin and light

    International Nuclear Information System (INIS)

    Granli, T.

    1993-01-01

    Large doses of light are given to newborns during phototherapy for hyperbilirubinemia. Tissues containing concentrations of bilirubin almost in the mM range may be subjected to irradiation. Therefore it is of interest to study cellular effects of light and bilirubin on cells. In order to select the optimal wavelength, possible detrimental effects of light on cells must be taken into consideration among a number of other factors. In this study cellular effects of selected wavelengths of blue-green light are compared. It is not clear whether cullular damage occurs in vivo during phototherapy of newborns. Since a possibility exists that some adverse effects are caused by light, one should choose wavelengths where these effects are minimal without loosing therapeutic efficiency. Todays knowledge of the photochemical mechanisms of phototherapy, indicates that short waved light with wavelengths below 450 nm has a low therapeutic effect. The data in this paper indicate that the cellular damage is most severe at short wavelengths, and these should be reduced to a minimum in the spectra of phototherapy lamps. Further studies of possible side effects of phototherapy should be made. 64 refs., 34 figs., 1 tab

  6. Integrating transcriptomics and proteomics to show that tanshinone IIA suppresses cell growth by blocking glucose metabolism in gastric cancer cells.

    Science.gov (United States)

    Lin, Li-Ling; Hsia, Chieh-Ren; Hsu, Chia-Lang; Huang, Hsuan-Cheng; Juan, Hsueh-Fen

    2015-02-05

    Tanshinone IIA (TIIA) is a diterpene quinone extracted from the plant Danshen (Salvia miltiorrhiza) used in traditional Chinese herbal medicine. It has been reported to have anti-tumor potential against several kinds of cancer, including gastric cancer. In most solid tumors, a metabolic switch to glucose is a hallmark of cancer cells, which do this to provide nutrients for cell proliferation. However, the mechanism associated with glucose metabolism by which TIIA acts on gastric cancer cells remains to be elucidated. We found that TIIA treatment is able to significantly inhibit cell growth and the proliferation of gastric cancer in a dose-dependent manner. Using next-generation sequencing-based RNA-seq transcriptomics and quantitative proteomics-isobaric tags for relative and absolute quantification (iTRAQ), we characterized the mechanism of TIIA regulation in gastric cancer cell line AGS. In total, 16,603 unique transcripts and 102 proteins were identified. After enrichment analysis, we found that TIIA regulated genes are involved in carbohydrate metabolism, the cell cycle, apoptosis, DNA damage and cytoskeleton reorganization. Our proteomics data revealed the downregulation of intracellular ATP levels, glucose-6-phosphate isomerase and L-lactate dehydrogenase B chains by TIIA, which might work with disorders of glucose metabolism and extracellular lactate levels to suppress cell proliferation. The up-regulation of p53 and down-regulation of AKT was shown in TIIA- treated cells, which indicates the transformation of oncogenes. Severe DNA damage, cell cycle arrest at the G2/M transition and apoptosis with cytoskeleton reorganization were detected in TIIA-treated gastric cancer cells. Combining transcriptomics and proteomics results, we propose that TIIA treatment could lead cell stresses, including nutrient deficiency and DNA damage, by inhibiting the glucose metabolism of cancer cells. This study provides an insight into how the TIIA regulatory metabolism in

  7. Chronic inflammatory cells and damaged limbal cells in pterygium

    African Journals Online (AJOL)

    EB

    2013-09-03

    Sep 3, 2013 ... Objective: To explain chronic inflammation in pterygium, and to clarify whether damaged limbal basal epithelial cells were ..... Jiang Y, Goldberg ID, Shi YE. Complex roles of tissue inhibitors of metalloproteinases in cancer. Oncogene 2002; 21: 2245-2252. 6. Kato S, Aoshima H, Saitoh Y, Miwa N. Fullerene-.

  8. Interleukin-35 induces regulatory B cells that suppress autoimmune disease.

    Science.gov (United States)

    Wang, Ren-Xi; Yu, Cheng-Rong; Dambuza, Ivy M; Mahdi, Rashid M; Dolinska, Monika B; Sergeev, Yuri V; Wingfield, Paul T; Kim, Sung-Hye; Egwuagu, Charles E

    2014-06-01

    Interleukin-10 (IL-10)-producing regulatory B (Breg) cells suppress autoimmune disease, and increased numbers of Breg cells prevent host defense to infection and promote tumor growth and metastasis by converting resting CD4(+) T cells to regulatory T (Treg) cells. The mechanisms mediating the induction and development of Breg cells remain unclear. Here we show that IL-35 induces Breg cells and promotes their conversion to a Breg subset that produces IL-35 as well as IL-10. Treatment of mice with IL-35 conferred protection from experimental autoimmune uveitis (EAU), and mice lacking IL-35 (p35 knockout (KO) mice) or defective in IL-35 signaling (IL-12Rβ2 KO mice) produced less Breg cells endogenously or after treatment with IL-35 and developed severe uveitis. Adoptive transfer of Breg cells induced by recombinant IL-35 suppressed EAU when transferred to mice with established disease, inhibiting pathogenic T helper type 17 (TH17) and TH1 cells while promoting Treg cell expansion. In B cells, IL-35 activates STAT1 and STAT3 through the IL-35 receptor comprising the IL-12Rβ2 and IL-27Rα subunits. As IL-35 also induced the conversion of human B cells into Breg cells, these findings suggest that IL-35 may be used to induce autologous Breg and IL-35(+) Breg cells and treat autoimmune and inflammatory disease.

  9. Perinatal testosterone exposure potentiates vascular dysfunction by ERβ suppression in endothelial progenitor cells.

    Science.gov (United States)

    Xie, Weiguo; Ren, Mingming; Li, Ling; Zhu, Yin; Chu, Zhigang; Zhu, Zhigang; Ruan, Qiongfang; Lou, Wenting; Zhang, Haimou; Han, Zhen; Huang, Xiaodong; Xiang, Wei; Wang, Tao; Yao, Paul

    2017-01-01

    Recent clinical cohort study shows that testosterone therapy increases cardiovascular diseases in men with low testosterone levels, excessive circulating androgen levels may play a detrimental role in the vascular system, while the potential mechanism and effect of testosterone exposure on the vascular function in offspring is still unknown. Our preliminary results showed that perinatal testosterone exposure in mice induces estrogen receptor β (ERβ) suppression in endothelial progenitor cells (EPCs) in offspring but not mothers, while estradiol (E2) had no effect. Further investigation showed that ERβ suppression is due to perinatal testosterone exposure-induced epigenetic changes with altered DNA methylation on the ERβ promoter. During aging, EPCs with ERβ suppression mobilize to the vascular wall, differentiate into ERβ-suppressed mouse endothelial cells (MECs) with downregulated expression of SOD2 (mitochondrial superoxide dismutase) and ERRα (estrogen-related receptor α). This results in reactive oxygen species (ROS) generation and DNA damage, and the dysfunction of mitochondria and fatty acid metabolism, subsequently potentiating vascular dysfunction. Bone marrow transplantation of EPCs that overexpressed with either ERβ or a SIRT1 single mutant SIRT1-C152(D) that could modulate SIRT1 phosphorylation significantly ameliorated vascular dysfunction, while ERβ knockdown worsened the problem. We conclude that perinatal testosterone exposure potentiates vascular dysfunction through ERβ suppression in EPCs.

  10. Leptin Suppresses Mouse Taste Cell Responses to Sweet Compounds.

    Science.gov (United States)

    Yoshida, Ryusuke; Noguchi, Kenshi; Shigemura, Noriatsu; Jyotaki, Masafumi; Takahashi, Ichiro; Margolskee, Robert F; Ninomiya, Yuzo

    2015-11-01

    Leptin is known to selectively suppress neural and behavioral responses to sweet-tasting compounds. However, the molecular basis for the effect of leptin on sweet taste is not known. Here, we report that leptin suppresses sweet taste via leptin receptors (Ob-Rb) and KATP channels expressed selectively in sweet-sensitive taste cells. Ob-Rb was more often expressed in taste cells that expressed T1R3 (a sweet receptor component) than in those that expressed glutamate-aspartate transporter (a marker for Type I taste cells) or GAD67 (a marker for Type III taste cells). Systemically administered leptin suppressed taste cell responses to sweet but not to bitter or sour compounds. This effect was blocked by a leptin antagonist and was absent in leptin receptor-deficient db/db mice and mice with diet-induced obesity. Blocking the KATP channel subunit sulfonylurea receptor 1, which was frequently coexpressed with Ob-Rb in T1R3-expressing taste cells, eliminated the effect of leptin on sweet taste. In contrast, activating the KATP channel with diazoxide mimicked the sweet-suppressing effect of leptin. These results indicate that leptin acts via Ob-Rb and KATP channels that are present in T1R3-expressing taste cells to selectively suppress their responses to sweet compounds. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  11. Regulatory T cells: immune suppression and beyond

    OpenAIRE

    Wan, Yisong Y

    2010-01-01

    Foxp3-expressing regulatory T cells (Tregs) were originally identified as critical in maintaining self-tolerance and immune homeostasis. The immunosuppressive functions of Tregs are widely acknowledged and have been extensively studied. Recent studies have revealed many diverse roles of Tregs in shaping the immune system and the inflammatory response. This review will discuss our efforts as well as the efforts of others towards understanding the multifaceted function of Treg...

  12. Special regulatory T cell review: The suppression problem!

    Science.gov (United States)

    Waldmann, Herman

    2008-01-01

    The concept of T-cell mediated suppression evolved more than 30 years ago. At that time it spawned many claims that have not stood the test of time. The rediscovery of suppression phenomena and regulatory T cells over the past 15 years created schizophrenic responses amongst immunologists. Some claimed that the new proponents of suppression were, once again, bringing immunology into disrepute, whilst others have embraced the field with great enthusiasm and novel approaches to clarification. Without faithful repetition of the "old" experiments, it is difficult to establish what was right and what was wrong. Nevertheless, immunologists must now accept that a good number of the old claims were overstated, and reflected poor scientific discipline. "I speak not to disprove what Brutus spoke, But here I am to speak what I do know" Shakespeare. Julius Caesar Act 3, Scene 2.

  13. The effect of caffeine and adenine on radiation induced suppression of DNA synthesis, and cell survival

    International Nuclear Information System (INIS)

    Wilcoxson, L.T.; Griffiths, T.D.

    1984-01-01

    Exposure of cultured mammalian cells to ionizing radiation or UV light results in a transient decrease in the rate of DNA synthesis. This depression in synthetic rate may be attenuated or deferred via a post-irradiation treatment with caffeine or adenine. It has been suggested that this attenuation may increase the fixation of damage and, therefore, increase radiation sensitivity. However, it has been previously reported that, for V79 cells treated with caffeine or adenine, no correlation exists between the extent of depression and cell survival. The present investigation expands upon these findings by examining the effect of caffeine or adenine post-irradiation treatment on two cell lines with normal UV sensitivity, mouse 3T3 and CHO AA8 cells, and one UV sensitive cell line, CHO UV5 cells. Both caffeine and adenine have been found to reduce, or delay, the suppression in DNA synthesis in all three cell lines. Surprisingly, caffeine appeared to induced even the UV5 cells to recover DNA synthetic ability. The amount of reduction in suppression of DNA synthesis, however, varies between the different cell lines and no consistent relationship with cell survival has emerged

  14. Docosahexaenoic Acid Induces Oxidative DNA Damage and Apoptosis, and Enhances the Chemosensitivity of Cancer Cells.

    Science.gov (United States)

    Song, Eun Ah; Kim, Hyeyoung

    2016-08-03

    The human diet contains low amounts of ω-3 polyunsaturated fatty acids (PUFAs) and high amounts of ω-6 PUFAs, which has been reported to contribute to the incidence of cancer. Epidemiological studies have shown that a high consumption of fish oil or ω-3 PUFAs reduced the risk of colon, pancreatic, and endometrial cancers. The ω-3 PUFA, docosahexaenoic acid (DHA), shows anticancer activity by inducing apoptosis of some human cancer cells without toxicity against normal cells. DHA induces oxidative stress and oxidative DNA adduct formation by depleting intracellular glutathione (GSH) and decreasing the mitochondrial function of cancer cells. Oxidative DNA damage and DNA strand breaks activate DNA damage responses to repair the damaged DNA. However, excessive DNA damage beyond the capacity of the DNA repair processes may initiate apoptotic signaling pathways and cell cycle arrest in cancer cells. DHA shows a variable inhibitory effect on cancer cell growth depending on the cells' molecular properties and degree of malignancy. It has been shown to affect DNA repair processes including DNA-dependent protein kinases and mismatch repair in cancer cells. Moreover, DHA enhanced the efficacy of anticancer drugs by increasing drug uptake and suppressing survival pathways in cancer cells. In this review, DHA-induced oxidative DNA damage, apoptotic signaling, and enhancement of chemosensitivity in cancer cells will be discussed based on recent studies.

  15. Carvedilol suppresses circulating and hepatic IL-6 responsible for hepatocarcinogenesis of chronically damaged liver in rats

    International Nuclear Information System (INIS)

    Balaha, Mohamed; Kandeel, Samah; Barakat, Waleed

    2016-01-01

    Carvedilol is an anti-oxidant non-selective β-blocker used for reduction of portal blood pressure, prophylaxis of esophageal varices development and bleeding in chronic liver diseases. Recently, it exhibited potent anti-inflammatory, anti-fibrotic, anti-proliferative and anti-carcinogenic effects. In the present study, we evaluated the possible suppressive effect of carvedilol on circulating and hepatic IL-6 levels responsible for hepatocarcinogenesis in a rat model of hepatic cirrhosis. Besides, its effect on hepatic STAT-3 levels, function tests, oxidative stress markers, and hydroxyproline content, hepatic tissue histopathological changes and immunohistochemical expression of E & N-cadherin. Nine-week-old male Wistar rats injected intraperitoneal by 1 ml/kg 10% CCL 4 in olive oil three times/week (every other day) for 12 weeks to induce hepatic cirrhosis. Carvedilol (10 mg/kg/day suspended in 0.5% CMC orally), silymarin (50 mg/kg/day suspended in 0.5% CMC orally) or combination of both used to treat hepatic cirrhosis from 15th to 84th day. Our data showed that carvedilol and silymarin co-treatment each alone or in combination efficiently reduced the elevated serum IL-6, ALT, AST, ALP and BIL, hepatic IL-6, STAT-3, MDA levels and hydroxyproline content. In addition, it elevated the reduced serum ALB level, hepatic CAT activity and GSH level. Meanwhile, it apparently restored the normal hepatic architecture, collagen distribution and immunohistochemical E & N-cadherin expression. Furthermore, carvedilol was superior to silymarin in improving MDA level. Moreover, the combination of carvedilol and silymarin showed an upper hand in amelioration of the CCL 4 induced hepatotoxicity than each alone. Therefore, carvedilol could be promising in prevention of hepatocarcinogenesis in chronic hepatic injuries. - Highlights: • Chronic liver damage ends into hepatocellular carcinoma in 5% of patients. • Persistent elevation of IL-6 induces hepatocarcinogenesis in chronic

  16. Non-cell autonomous or secretory tumor suppression.

    Science.gov (United States)

    Chua, Christelle En Lin; Chan, Shu Ning; Tang, Bor Luen

    2014-10-01

    Many malignancies result from deletions or loss-of-function mutations in one or more tumor suppressor genes, the products of which curb unrestrained growth or induce cell death in those with dysregulated proliferative capacities. Most tumor suppressors act in a cell autonomous manner, and only very few proteins are shown to exert a non-cell autonomous tumor suppressor function on other cells. Examples of these include members of the secreted frizzled-related protein (SFRP) family and the secreted protein acidic and rich in cysteine (SPARC)-related proteins. Very recent findings have, however, considerably expanded our appreciation of non-cell autonomous tumor suppressor functions. Broadly, this may occur in two ways. Intracellular tumor suppressor proteins within cells could in principle inhibit aberrant growth of neighboring cells by conditioning an antitumor microenvironment through secreted factors. This is demonstrated by an apparent non-cell autonomous tumor suppressing property of p53. On the other hand, a tumor suppressor produced by a cell may be secreted extracellularly, and taken up by another cell with its activity intact. Intriguingly, this has been recently shown to occur for the phosphatase and tensin homolog (PTEN) by both conventional and unconventional modes of secretion. These recent findings would aid the development of therapeutic strategies that seek to reinstate tumor suppression activity in therapeutically recalcitrant tumor cells, which have lost it in the first place. © 2014 Wiley Periodicals, Inc.

  17. Docosahexaenoic Acid Induces Oxidative DNA Damage and Apoptosis, and Enhances the Chemosensitivity of Cancer Cells

    Directory of Open Access Journals (Sweden)

    Eun Ah Song

    2016-08-01

    Full Text Available The human diet contains low amounts of ω-3 polyunsaturated fatty acids (PUFAs and high amounts of ω-6 PUFAs, which has been reported to contribute to the incidence of cancer. Epidemiological studies have shown that a high consumption of fish oil or ω-3 PUFAs reduced the risk of colon, pancreatic, and endometrial cancers. The ω-3 PUFA, docosahexaenoic acid (DHA, shows anticancer activity by inducing apoptosis of some human cancer cells without toxicity against normal cells. DHA induces oxidative stress and oxidative DNA adduct formation by depleting intracellular glutathione (GSH and decreasing the mitochondrial function of cancer cells. Oxidative DNA damage and DNA strand breaks activate DNA damage responses to repair the damaged DNA. However, excessive DNA damage beyond the capacity of the DNA repair processes may initiate apoptotic signaling pathways and cell cycle arrest in cancer cells. DHA shows a variable inhibitory effect on cancer cell growth depending on the cells’ molecular properties and degree of malignancy. It has been shown to affect DNA repair processes including DNA-dependent protein kinases and mismatch repair in cancer cells. Moreover, DHA enhanced the efficacy of anticancer drugs by increasing drug uptake and suppressing survival pathways in cancer cells. In this review, DHA-induced oxidative DNA damage, apoptotic signaling, and enhancement of chemosensitivity in cancer cells will be discussed based on recent studies.

  18. Bacterial Cell Surface Damage Due to Centrifugal Compaction

    NARCIS (Netherlands)

    Peterson, Brandon W.; Sharma, Prashant K.; van der Mei, Henny C.; Busscher, Henk J.

    Centrifugal damage has been known to alter bacterial cell surface properties and interior structures, including DNA. Very few studies exist on bacterial damage caused by centrifugation because of the difficulty in relating centrifugation speed and container geometry to the damage caused. Here, we

  19. Change in the dibenzyldimethylammonium accumulation by irradiated Streptococcus cells caused by radiation damage modifiers

    International Nuclear Information System (INIS)

    Fomenko, B.S.; Leont'eva, G.A.

    1975-01-01

    Anoxia, concentrated cell suspension, glutathione (10 -4 -10 -2 M) or low concentrations of cysteine (10 -4 -10 -3 M) exerted a radioprotective effect and suppressed the accumulation of dibenzyldimethylammonium chloride (DDA + ) by γ-irradiated (40 krad) S. faecalis cells. Dilution of the cell suspensions and higher cysteine concentrations (>10 -3 M) increased the effects of irradiation on bacterial accumulation of DDA + and decreased the cell survival. The lethal action of irradiation apparently involves damage to the mechanisms which maintain a normal membrane potential

  20. Suppression of deuterium-induced blistering in pre-damaged tungsten exposed to short-duration deuterium plasma

    Science.gov (United States)

    Zhu, Xiu-Li; Zhang, Ying; Cheng, Long; Shi, Li-Qun; De Temmerman, Gregory; Yuan, Yue; Liu, Hui-Ping; Lu, Guang-Hong

    2018-03-01

    Effects of pre-damage by 500 keV argon ion implantation on deuterium-induced blistering in tungsten has been investigated. After low-energy (40 eV) and high-flux (∼1024 D/m2s) deuterium plasma exposure with short exposure duration (100 s), a large increase of deuterium retention is found in the pre-damaged tungsten, while surface blistering is significantly suppressed as compared to the un-damaged one. According to elastic recoil detection analysis, a local deuterium concentration peak is observed at a depth of ∼100 nm for the un-damaged tungsten, which is supposed to be related to the surface blistering with nanometer size. Comparison of deuterium retention in the near surface (within 300 nm) and in the bulk suggests that deuterium inward diffusion is more significant in the pre-damaged tungsten. It is speculated that the creation of deuterium trap-sites and enhancement of deuterium inward diffusion give rise to an increase of critical deuterium concentration for blistering and contribute to the suppressed deuterium-induced blistering on pre-damaged tungsten under the present exposure conditions.

  1. A novel telomerase activator suppresses lung damage in a murine model of idiopathic pulmonary fibrosis.

    Directory of Open Access Journals (Sweden)

    Claude Jourdan Le Saux

    Full Text Available The emergence of diseases associated with telomere dysfunction, including AIDS, aplastic anemia and pulmonary fibrosis, has bolstered interest in telomerase activators. We report identification of a new small molecule activator, GRN510, with activity ex vivo and in vivo. Using a novel mouse model, we tested the potential of GRN510 to limit fibrosis induced by bleomycin in mTERT heterozygous mice. Treatment with GRN510 at 10 mg/kg/day activated telomerase 2-4 fold both in hematopoietic progenitors ex vivo and in bone marrow and lung tissue in vivo, respectively. Telomerase activation was countered by co-treatment with Imetelstat (GRN163L, a potent telomerase inhibitor. In this model of bleomycin-induced fibrosis, treatment with GRN510 suppressed the development of fibrosis and accumulation of senescent cells in the lung via a mechanism dependent upon telomerase activation. Treatment of small airway epithelial cells (SAEC or lung fibroblasts ex vivo with GRN510 revealed telomerase activating and replicative lifespan promoting effects only in the SAEC, suggesting that the mechanism accounting for the protective effects of GRN510 against induced lung fibrosis involves specific types of lung cells. Together, these results support the use of small molecule activators of telomerase in therapies to treat idiopathic pulmonary fibrosis.

  2. Isolation of Treg cells and Treg cell suppression/death assay

    OpenAIRE

    sprotocols

    2015-01-01

    In vitro Treg suppression assays are performed to determine the functional effect of Treg cells on CD4 T cells. They are performed by co-culturing the responding population (Tresp) with the Treg cells or control CD4 cells (Tcon cells).

  3. Suppression of T cell-induced osteoclast formation

    Energy Technology Data Exchange (ETDEWEB)

    Karieb, Sahar; Fox, Simon W., E-mail: Simon.fox@plymouth.ac.uk

    2013-07-12

    Highlights: •Genistein and coumestrol prevent activated T cell induced osteoclast formation. •Anti-TNF neutralising antibodies prevent the pro-osteoclastic effect of activated T cells. •Phytoestrogens inhibit T cell derived TNF alpha and inflammatory cytokine production. •Phytoestrogens have a broader range of anti-osteoclastic actions than other anti-resorptives. -- Abstract: Inhibition of T cell derived cytokine production could help suppress osteoclast differentiation in inflammatory skeletal disorders. Bisphosphonates are typically prescribed to prevent inflammatory bone loss but are not tolerated by all patients and are associated with an increased risk of osteonecrosis of the jaw. In light of this other anti-resorptives such as phytoestrogens are being considered. However the effect of phytoestrogens on T cell-induced osteoclast formation is unclear. The effect of genistein and coumestrol on activated T cell-induced osteoclastogenesis and cytokine production was therefore examined. Concentrations of genistein and coumestrol (10{sup −7} M) previously shown to directly inhibit osteoclast formation also suppressed the formation of TRAP positive osteoclast induced by con A activated T cells, which was dependent on inhibition of T cell derived TNF-α. While both reduced osteoclast formation their mechanism of action differed. The anti-osteoclastic effect of coumestrol was associated with a dual effect on con A induced T cell proliferation and activation; 10{sup −7} M coumestrol significantly reducing T cell number (0.36) and TNF-α (0.47), IL-1β (0.23) and IL-6 (0.35) expression, whereas genistein (10{sup −7} M) had no effect on T cell number but a more pronounced effect on T cell differentiation reducing expression of TNF-α (0.49), IL-1β (0.52), IL-6 (0.71) and RANKL (0.71). Phytoestrogens therefore prevent the pro-osteoclastic action of T cells suggesting they may have a role in the control of inflammatory bone loss.

  4. Efficacy of Mesenchymal Stem Cells in Suppression of Hepatocarcinorigenesis in Rats: Possible Role of Wnt Signaling

    Directory of Open Access Journals (Sweden)

    Sabry Dina

    2011-05-01

    Full Text Available Abstract Background The present study was conducted to evaluate the tumor suppressive effects of bone marrow derived mesenchymal stem cells (MSCs in an experimental hepatocellular carcinoma (HCC model in rats and to investigate the possible role of Wnt signaling in hepato-carcinogenesis. Methods Ninety rats were included in the study and were divided equally into: Control group, rats which received MSCs only, rats which received MSCs vehicle only, HCC group induced by diethylnitroseamine (DENA and CCl4, rats which received MSCs after HCC induction, rats which received MSCs before HCC induction. Histopathological examination and gene expression of Wnt signaling target genes by real time, reverse transcription-polymerase chain reaction (RT-PCR in rat liver tissue, in addition to serum levels of ALT, AST and alpha fetoprotein were performed in all groups. Results Histopathological examination of liver tissue from animals which received DENA-CCl4 only, revealed the presence of anaplastic carcinoma cells and macro-regenerative nodules type II with foci of large and small cell dysplasia. Administration of MSCs into rats after induction of experimental HCC improved the histopathological picture which showed minimal liver cell damage, reversible changes, areas of cell drop out filled with stem cells. Gene expression in rat liver tissue demonstrated that MSCs downregulated β-catenin, proliferating cell nuclear antigen (PCNA, cyclin D and survivin genes expression in liver tissues after HCC induction. Amelioration of the liver status after administration of MSCs has been inferred by the significant decrease of ALT, AST and Alpha fetoprotein serum levels. Administration of MSCs before HCC induction did not show any tumor suppressive or protective effect. Conclusions Administration of MSCs in chemically induced HCC has tumor suppressive effects as evidenced by down regulation of Wnt signaling target genes concerned with antiapoptosis, mitogenesis, cell

  5. Efficacy of Mesenchymal Stem Cells in Suppression of Hepatocarcinorigenesis in Rats: Possible Role of Wnt Signaling

    LENUS (Irish Health Repository)

    Abdel Aziz, Mohamed T

    2011-05-05

    Abstract Background The present study was conducted to evaluate the tumor suppressive effects of bone marrow derived mesenchymal stem cells (MSCs) in an experimental hepatocellular carcinoma (HCC) model in rats and to investigate the possible role of Wnt signaling in hepato-carcinogenesis. Methods Ninety rats were included in the study and were divided equally into: Control group, rats which received MSCs only, rats which received MSCs vehicle only, HCC group induced by diethylnitroseamine (DENA) and CCl 4 , rats which received MSCs after HCC induction, rats which received MSCs before HCC induction. Histopathological examination and gene expression of Wnt signaling target genes by real time, reverse transcription-polymerase chain reaction (RT-PCR) in rat liver tissue, in addition to serum levels of ALT, AST and alpha fetoprotein were performed in all groups. Results Histopathological examination of liver tissue from animals which received DENA-CCl4 only, revealed the presence of anaplastic carcinoma cells and macro-regenerative nodules type II with foci of large and small cell dysplasia. Administration of MSCs into rats after induction of experimental HCC improved the histopathological picture which showed minimal liver cell damage, reversible changes, areas of cell drop out filled with stem cells. Gene expression in rat liver tissue demonstrated that MSCs downregulated β-catenin, proliferating cell nuclear antigen (PCNA), cyclin D and survivin genes expression in liver tissues after HCC induction. Amelioration of the liver status after administration of MSCs has been inferred by the significant decrease of ALT, AST and Alpha fetoprotein serum levels. Administration of MSCs before HCC induction did not show any tumor suppressive or protective effect. Conclusions Administration of MSCs in chemically induced HCC has tumor suppressive effects as evidenced by down regulation of Wnt signaling target genes concerned with antiapoptosis, mitogenesis, cell proliferation

  6. Phyllanthus emblica L. fruit extract induces chromosomal instability and suppresses necrosis in human colon cancer cells.

    Science.gov (United States)

    Guo, Xihan; Ni, Juan; Liu, Xuemin; Xue, Jinglun; Wang, Xu

    2013-01-01

    Phyllanthus emblica L. (PE) is an edible fruit indigenous to Southeast Asia. It has been considered as a potent functional food due to its numerous pharmacological applications, such as anti-oxidant, antimicrobial, anti-diabetic and protection for multiple organs. The aim of this study was to evaluate the effects of a water extract of PE fruit on genomic damage and cell death in the human colon adenocarcinoma cell line COLO320 using the cytokinesis-block micronucleus cytome assay. Cells were exposed to RPMI-1640 medium containing 0, 20, 40, 80, or 160 μg/mL PE for 24, 48, 72, or 96 hours. The results showed that PE induced a significant decrease in necrosis (p PE exposure, and the frequency of CIN was negatively correlated with NDI (r = - 0.640, p PE also significantly increased apoptosis (p PE suppresses necrosis and delays mitotic progression, which results in massive CIN followed by apoptosis in COLO320 cells.

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

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  8. Components of Streptococcus pneumoniae suppress allergic airways disease and NKT cells by inducing regulatory T cells.

    Science.gov (United States)

    Thorburn, Alison N; Foster, Paul S; Gibson, Peter G; Hansbro, Philip M

    2012-05-01

    Asthma is an allergic airways disease (AAD) caused by dysregulated immune responses and characterized by eosinophilic inflammation, mucus hypersecretion, and airway hyperresponsiveness (AHR). NKT cells have been shown to contribute to AHR in some mouse models. Conversely, regulatory T cells (Tregs) control aberrant immune responses and maintain homeostasis. Recent evidence suggests that Streptococcus pneumoniae induces Tregs that have potential to be harnessed therapeutically for asthma. In this study, mouse models of AAD were used to identify the S. pneumoniae components that have suppressive properties, and the mechanisms underlying suppression were investigated. We tested the suppressive capacity of type-3-polysaccharide (T3P), isolated cell walls, pneumolysoid (Ply) and CpG. When coadministered, T3P + Ply suppressed the development of: eosinophilic inflammation, Th2 cytokine release, mucus hypersecretion, and AHR. Importantly, T3P + Ply also attenuated features of AAD when administered during established disease. We show that NKT cells contributed to the development of AAD and also were suppressed by T3P + Ply treatment. Furthermore, adoptive transfer of NKT cells induced AHR, which also could be reversed by T3P + Ply. T3P + Ply-induced Tregs were essential for the suppression of NKT cells and AAD, which was demonstrated by Treg depletion. Collectively, our results show that the S. pneumoniae components T3P + Ply suppress AAD through the induction of Tregs that blocked the activity of NKT cells. These data suggest that S. pneumoniae components may have potential as a therapeutic strategy for the suppression of allergic asthma through the induction of Tregs and suppression of NKT cells.

  9. Metastasis suppressor NM23-H1 promotes repair of UV-induced DNA damage and suppresses UV-induced melanomagenesis.

    Science.gov (United States)

    Jarrett, Stuart G; Novak, Marian; Dabernat, Sandrine; Daniel, Jean-Yves; Mellon, Isabel; Zhang, Qingbei; Harris, Nathan; Ciesielski, Michael J; Fenstermaker, Robert A; Kovacic, Diane; Slominski, Andrzej; Kaetzel, David M

    2012-01-01

    Reduced expression of the metastasis suppressor NM23-H1 is associated with aggressive forms of multiple cancers. Here, we establish that NM23-H1 (termed H1 isoform in human, M1 in mouse) and two of its attendant enzymatic activities, the 3'-5' exonuclease and nucleoside diphosphate kinase, are novel participants in the cellular response to UV radiation (UVR)-induced DNA damage. NM23-H1 deficiency compromised the kinetics of repair for total DNA polymerase-blocking lesions and nucleotide excision repair of (6-4) photoproducts in vitro. Kinase activity of NM23-H1 was critical for rapid repair of both polychromatic UVB/UVA-induced (290-400 nm) and UVC-induced (254 nm) DNA damage, whereas its 3'-5' exonuclease activity was dominant in the suppression of UVR-induced mutagenesis. Consistent with its role in DNA repair, NM23-H1 rapidly translocated to sites of UVR-induced (6-4) photoproduct DNA damage in the nucleus. In addition, transgenic mice hemizygous-null for nm23-m1 and nm23-m2 exhibited UVR-induced melanoma and follicular infundibular cyst formation, and tumor-associated melanocytes displayed invasion into adjacent dermis, consistent with loss of invasion-suppressing activity of NM23 in vivo. Taken together, our data show a critical role for NM23 isoforms in limiting mutagenesis and suppressing UVR-induced melanomagenesis. ©2011 AACR.

  10. Analyses of the cell mechanical damage during microinjection.

    Science.gov (United States)

    Liu, Fei; Wu, Dan; Wu, Xiaoyong; Chen, Ken

    2015-02-04

    The microinjection is an essential technique to introduce foreign materials into biological cells. The soft cell is inevitably ruptured by the microinjector during microinjection. We discuss the way to reduce the mechanical damage by analyzing the control parameters during microinjection. The computational model is developed with the dissipative particle dynamics to simulate the soft mechanical properties of biological cells. The cell model contains the membrane networks, the internal cytoskeleton, crosslink proteins, motors and their functions. The weak power law rheology verifies our computational model. The number of ruptured bonds is used to describe the extent of the mechanical damage that the cell experiences during microinjection. Some experiments are conducted on the Zebrafish embryos. Both the simulation works and experimental results show that the size, shape of the microinjector tip, and the injection velocity have a significant influence on the cell damage. A small, sharp microinjector with a high velocity can reduce the mechanical damage.

  11. Track structure model of cell damage in space flight

    Science.gov (United States)

    Katz, Robert; Cucinotta, Francis A.; Wilson, John W.; Shinn, Judy L.; Ngo, Duc M.

    1992-01-01

    The phenomenological track-structure model of cell damage is discussed. A description of the application of the track-structure model with the NASA Langley transport code for laboratory and space radiation is given. Comparisons to experimental results for cell survival during exposure to monoenergetic, heavy-ion beams are made. The model is also applied to predict cell damage rates and relative biological effectiveness for deep-space exposures.

  12. Sarcophytols and protease inhibitors suppress H2O2 formation and oxidative DNA damage

    International Nuclear Information System (INIS)

    Frenkel, K.; Zhaojing Zhong; Rashid, K.; Fujiki, Hirota

    1991-01-01

    Active oxygen species (OS) can be generated by ionizing radiation as well as endogenously through a number of metabolic processes. These include activation of xenobiotics, such as polycyclic aromatic hydrocarbons, aromatic amines and nitrocompounds, induction of OS-generating enzymes by for example peroxisome proliferaters, action of tumor promoters, and inhibition of antioxidant defenses. All of these pathways have been implicated as playing a role in carcinogenic processes. Hence, treatments that would decrease production of such OS are likely to suppress tumor formation and play a role as anticarcinogens. Major cellular sources of active OS are polymorphonuclear leukocytes (PMNs), which are phagocytic cells whose main function is to recognize, phagocytize, and destroy bacteria and other opsonized particles. However, they can also be activated by inappropriate stimuli such as tumor promoters. Regardless of the type of stimulus, PMNs undergo an oxidative burst that is characterized by rapid consumption of molecular O 2 , followed in quick succession with the production of copious amounts of superoxide anion radicals (·O 2 - ), which dismutate spontaneously and enzymatically to H 2 O 2 . It is H 2 O 2 that is the immediate precursor of the actual bacteriocidal species hypochlorite (HOCl) and hydroxyl radicals (·OH). Formation of HOCl is mediated by myeloperoxidase, and that of ·OH by iron ions, which are kept in the reduced state by ·O 2 - . 43 refs., 4 figs., 3 tabs

  13. Repair of potentially lethal and sublethal radiation damage in x-irradiated ascites tumor cells

    International Nuclear Information System (INIS)

    Tsuboi, Atsushi; Okamoto, Mieko; Tsuchiya, Takehiko.

    1985-01-01

    The ability of cells to repair cellular radiation damage during the growth of TMT-3 ascites tumor and the effect of host reaction on the repair ability were examined by using an in vitro assay of cell clonogenicity after in situ irradiation of tumor cells. In single-dose experiments, the repair of potentially lethal radiation damage (PLD) was observed in stationary phase cells (12-day tumor) of the unirradiated host, but not in exponential phase cells (3-day tumor) of the unirradiated host animals. However, if previously irradiated host animals were used, even the exponentially growing tumor cells showed repair of PLD. In two-dose experiments, the ability to repair sublethal radiation damage (SLD) in exponential phase tumor cells was less than that of stationary phase cells in the unirradiated host. In the pre-irradiated host, the extent of the repair in exponential phase cells was somewhat enhanced. These results suggest that irradiation of host animals might suppress a factor that inhibits repair, resulting in enhancement of the repair capability of tumor cells. (author)

  14. Ketamine suppresses the proliferation of rat C6 glioma cells.

    Science.gov (United States)

    Niwa, Hidetomo; Furukawa, Ken-Ichi; Seya, Kazuhiko; Hirota, Kazuyoshi

    2017-10-01

    The present study investigated the effects of N-methyl-D-aspartate receptor (NMDAR) antagonist ketamine, on the growth of gliomas. To analyze the effects of ketamine treatment, rat C6 glioma cells arising from astrocytes, and RNB cells representing non-malignant astrocytes, were examined. In ketamine-treated C6 cells, the gene expression changes associated with cell proliferation following ketamine treatment were evaluated using a cDNA microarray. A cell proliferation assay was performed to analyze the dose-dependent proliferation of C6 glioma and RNB cells following culture (72 h) with ketamine treatment (0-100 µM). Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assays were performed following cell incubation with/without ketamine, to confirm if the ketamine-induced cell death of C6 glioma and RNB cells were due to apoptosis. In addition, cell proliferation and TUNEL assays were performed following cell incubations with a selective NMDAR antagonist, D-2-amino-5-phosphonovaleric acid (D-AP5). Analysis of the cDNA microarray indicated that the growth of C6 glioma cells were suppressed by the effects of ketamine. Furthermore, results of the proliferation assay confirmed that ketamine treatment inhibited C6 cell proliferation, most notably at a dose of 30 µM (n=7, 66.4%; Pcells, with a significant effect on the rate of death observed at all tested concentrations (3, 10, 30 and 100 µM). Results of the aforementioned proliferation and TUNEL assay experiments were reproduced when ketamine was replaced with a selective NMDAR antagonist, D-AP5. However, the NMDARantagonist-induced effects were not observed in RNB cell cultures. Although it would be premature to apply the results from the present study to human cases, these results indicated that ketamine is an anesthetic candidate providing potential benefit for glioma resection.

  15. miR-24-mediated down-regulation of H2AX suppresses DNA repair in terminally differentiated blood cells

    Science.gov (United States)

    Lal, Ashish; Pan, Yunfeng; Navarro, Francisco; Dykxhoorn, Derek M.; Moreau, Lisa; Meire, Eti; Bentwich, Zvi; Lieberman, Judy; Chowdhury, Dipanjan

    2010-01-01

    Terminally differentiated cells have reduced capacity to repair double strand breaks (DSB), but the molecular mechanism behind this down-regulation is unclear. Here we find that miR-24 is consistently up-regulated during post-mitotic differentiation of hematopoietic cell lines and regulates the histone variant H2AX, a key DSB repair protein that activates cell cycle checkpoint proteins and retains DSB repair factors at DSB foci. The H2AX 3’UTR contains conserved miR-24 binding sites regulated by miR-24. Both H2AX mRNA and protein are substantially reduced during hematopoietic cell terminal differentiation by miR-24 up-regulation both in in vitro differentiated cells and primary human blood cells. miR-24 suppression of H2AX renders cells hypersensitive to γ-irradiation and genotoxic drugs. Antagonizing miR-24 in differentiating cells protects them from DNA damage-induced cell death, while transfecting miR-24 mimics in dividing cells increases chromosomal breaks and unrepaired DNA damage and reduces viability in response to DNA damage. This DNA repair phenotype can be fully rescued by over-expressing miR-24-insensitive H2AX. Therefore, miR-24 up-regulation in post-replicative cells reduces H2AX and thereby renders them highly vulnerable to DNA damage. PMID:19377482

  16. Genistein suppresses aerobic glycolysis and induces hepatocellular carcinoma cell death.

    Science.gov (United States)

    Li, Sainan; Li, Jingjing; Dai, Weiqi; Zhang, Qinghui; Feng, Jiao; Wu, Liwei; Liu, Tong; Yu, Qiang; Xu, Shizan; Wang, Wenwen; Lu, Xiya; Chen, Kan; Xia, Yujing; Lu, Jie; Zhou, Yingqun; Fan, Xiaoming; Mo, Wenhui; Xu, Ling; Guo, Chuanyong

    2017-11-07

    Genistein is a natural isoflavone with many health benefits, including antitumour effects. Increased hypoxia-inducible factor 1 α (HIF-1α) levels and glycolysis in tumour cells are associated with an increased risk of mortality, cancer progression, and resistance to therapy. However, the effect of genistein on HIF-1α and glycolysis in hepatocellular carcinoma (HCC) is still unclear. Cell viability, apoptosis rate, lactate production, and glucose uptake were measured in HCC cell lines with genistein incubation. Lentivirus-expressed glucose transporter 1 (GLUT1) or/and hexokinase 2 (HK2) and siRNA of HIF-1α were used to test the direct target of genistein. Subcutaneous xenograft mouse models were used to measure in vivo efficacy of genistein and its combination with sorafenib. Genistein inhibited aerobic glycolysis and induced mitochondrial apoptosis in HCC cells. Neither inhibitors nor overexpression of HK2 or GLUTs enhance or alleviate this effect. Although stabiliser of HIF-1α reversed the effect of genistein, genistein no longer has effects on HIF-1α siRNA knockdown HCC cells. In addition, genistein enhanced the antitumour effect of sorafenib in sorafenib-resistant HCC cells and HCC-bearing mice. Genistein sensitised aerobic glycolytic HCC cells to apoptosis by directly downregulating HIF-1α, therefore inactivating GLUT1 and HK2 to suppress aerobic glycolysis. The inhibitory effect of genistein on tumour cell growth and glycolysis may help identify effective treatments for HCC patients at advanced stages.

  17. Potentially lethal damage versus sublethal damage: independent repair processes in actively growing Chinese hamster cells

    International Nuclear Information System (INIS)

    Utsumi, H.; Elkind, M.M.

    1979-01-01

    Actively growing V79 Chinese hamster cells, treated with anisotonic phosphate-buffered saline (PBS) after x irradiation, are more sensitive than cells treated with isotonic PBS or cells promptly incubated with complete medium immediately after irradiation. The sensitization of irradiated cells results from hypotonic as well as hypertonic NaCl concentrations in PBS, is strongly dependent on both temperature and time, and is mainly due to an increase in the final slope of the single-dose survival curve. After two x-ray dose fractions, the net response of cells sensitized after each fraction by anisotonic post-treatment is similar to that obtained for isotonically treated cells and indicates that sublethal damage repair is not influenced by the enhanced expression of lethal damage. Independence of the repair of damage which is potentially lethal from the repair of damage which is sublethal is further suggested by the more rapid rate of the former compared to that of the latter. The proposal is advanced that the enhanced expression of damage which, after x irradiation, can be shown to be potentially lethal results from a destabilization of the structural relationship between DNA and the nuclear envelope, and/or DNA and the nuclear protein matrix, as a consequence of osmotic changes produced by anisotonic treatment

  18. Modeling the role of p53 pulses in DNA damage- induced cell death decision

    Directory of Open Access Journals (Sweden)

    Cui Jun

    2009-06-01

    Full Text Available Abstract Background The tumor suppressor p53 plays pivotal roles in tumorigenesis suppression. Although oscillations of p53 have been extensively studied, the mechanism of p53 pulses and their physiological roles in DNA damage response remain unclear. Results To address these questions we presented an integrated model in which Ataxia-Telangiectasia Mutated (ATM activation and p53 oscillation were incorporated with downstream apoptotic events, particularly the interplays between Bcl-2 family proteins. We first reproduced digital oscillation of p53 as the response of normal cells to DNA damage. Subsequent modeling in mutant cells showed that high basal DNA damage is a plausible cause for sustained p53 pulses observed in tumor cells. Further computational analyses indicated that p53-dependent PUMA accumulation and the PUMA-controlled Bax activation switch might play pivotal roles to count p53 pulses and thus decide the cell fate. Conclusion The high levels of basal DNA damage are responsible for generating sustained pulses of p53 in the tumor cells. Meanwhile, the Bax activation switch can count p53 pulses through PUMA accumulation and transfer it into death signal. Our modeling provides a plausible mechanism about how cells generate and orchestrate p53 pulses to tip the balance between survival and death.

  19. ATP Release from Chemotherapy-Treated Dying Leukemia Cells Elicits an Immune Suppressive Effect by Increasing Regulatory T Cells and Tolerogenic Dendritic Cells.

    Science.gov (United States)

    Lecciso, Mariangela; Ocadlikova, Darina; Sangaletti, Sabina; Trabanelli, Sara; De Marchi, Elena; Orioli, Elisa; Pegoraro, Anna; Portararo, Paola; Jandus, Camilla; Bontadini, Andrea; Redavid, Annarita; Salvestrini, Valentina; Romero, Pedro; Colombo, Mario P; Di Virgilio, Francesco; Cavo, Michele; Adinolfi, Elena; Curti, Antonio

    2017-01-01

    Chemotherapy-induced immunogenic cell death can favor dendritic cell (DC) cross-priming of tumor-associated antigens for T cell activation thanks to the release of damage-associated molecular patterns, including ATP. Here, we tested the hypothesis that in acute myeloid leukemia (AML), ATP release, along with its well-known immune stimulatory effect, may also contribute to the generation of an immune suppressive microenvironment. In a cohort of AML patients, undergoing combined daunorubicin and cytarabine chemotherapy, a population of T regulatory cells (Tregs) with suppressive phenotype, expressing the immune checkpoint programmed cell death protein 1 (PD-1), was significantly increased. Moving from these results, initial in vitro data showed that daunorubicin was more effective than cytarabine in modulating DC function toward Tregs induction and such difference was correlated with the higher capacity of daunorubicin to induce ATP release from treated AML cells. DCs cultured with daunorubicin-treated AML cells upregulated indoleamine 2,3-dioxygenase 1 (IDO1), which induced anti-leukemia Tregs. These data were confirmed in vivo as daunorubicin-treated mice show an increase in extracellular ATP levels with increased number of Tregs, expressing PD-1 and IDO1 + CD39 + DCs. Notably, daunorubicin failed to induce Tregs and tolerogenic DCs in mice lacking the ATP receptor P2X7. Our data indicate that ATP release from chemotherapy-treated dying cells contributes to create an immune suppressive microenvironment in AML.

  20. ATP Release from Chemotherapy-Treated Dying Leukemia Cells Elicits an Immune Suppressive Effect by Increasing Regulatory T Cells and Tolerogenic Dendritic Cells

    Directory of Open Access Journals (Sweden)

    Mariangela Lecciso

    2017-12-01

    Full Text Available Chemotherapy-induced immunogenic cell death can favor dendritic cell (DC cross-priming of tumor-associated antigens for T cell activation thanks to the release of damage-associated molecular patterns, including ATP. Here, we tested the hypothesis that in acute myeloid leukemia (AML, ATP release, along with its well-known immune stimulatory effect, may also contribute to the generation of an immune suppressive microenvironment. In a cohort of AML patients, undergoing combined daunorubicin and cytarabine chemotherapy, a population of T regulatory cells (Tregs with suppressive phenotype, expressing the immune checkpoint programmed cell death protein 1 (PD-1, was significantly increased. Moving from these results, initial in vitro data showed that daunorubicin was more effective than cytarabine in modulating DC function toward Tregs induction and such difference was correlated with the higher capacity of daunorubicin to induce ATP release from treated AML cells. DCs cultured with daunorubicin-treated AML cells upregulated indoleamine 2,3-dioxygenase 1 (IDO1, which induced anti-leukemia Tregs. These data were confirmed in vivo as daunorubicin-treated mice show an increase in extracellular ATP levels with increased number of Tregs, expressing PD-1 and IDO1+CD39+ DCs. Notably, daunorubicin failed to induce Tregs and tolerogenic DCs in mice lacking the ATP receptor P2X7. Our data indicate that ATP release from chemotherapy-treated dying cells contributes to create an immune suppressive microenvironment in AML.

  1. The Limits of Linked Suppression for Regulatory T cells

    Directory of Open Access Journals (Sweden)

    Toshiro eIto

    2016-03-01

    Full Text Available Background: We have previously found that CD4+CD25+ regulatory T cells (T regs can adoptively transfer tolerance after its induction with co-stimulatory blockade in a mouse model of murine cardiac allograft transplantation. In these experiments, we tested an hypothesis with three components: 1 the T regs that transfer tolerance have the capacity for linked suppression, 2 the determinants that stimulate the T regs are expressed by the indirect pathway, and 3 the donor peptides contributing to these indirect determinants are derived from donor MHC antigens. Methods: 1st heart transplants were performed from the indicated donor strain to B10.D2 recipients along with co-stimulatory blockade treatment (250μg i.p. injection of MR1 on day 0 and 250μg i.p. injection of CTLA-4 Ig on day 2. At least 8 weeks later a 2nd heart transplant was performed to a new B10.D2 recipient that had been irradiated with 450 cGy. This recipient was given 40 x 106 naïve B10.D2 spleen cells plus 40 x 106 B10.D2 spleen cells from the first (tolerant recipient. We performed 3 different types of heart transplants with using various donor.Results: 1. T regs suppress the graft rejection in an antigen-specific manner. 2. T regs generated in the face of MHC disparities suppress the rejection of grafts expressing third party MHC along with tolerant MHC. Conclusion:The limits of linkage appear to be quantitative and not universally determined by either the indirect pathway or by peptides of donor MHC antigens.

  2. Mechanisms of cell damage in agitated microcarrier tissue culture reactors

    Science.gov (United States)

    Cherry, Robert S.; Papoutsakis, E. Terry

    1986-01-01

    Cells growing on microcarriers may be damaged by collisions of the microcarrier against another microcarrier or the reactor agitator. Bead-bead collisions are caused by small-scale turbulence, which can also cause high local shear stress on the cells. The cells are also exposed to 10-20 Hz cyclic shear stress by bead rotation.

  3. Novel DNA damage checkpoint in mitosis: Mitotic DNA damage induces re-replication without cell division in various cancer cells.

    Science.gov (United States)

    Hyun, Sun-Yi; Rosen, Eliot M; Jang, Young-Joo

    2012-07-06

    DNA damage induces multiple checkpoint pathways to arrest cell cycle progression until damage is repaired. In our previous reports, when DNA damage occurred in prometaphase, cells were accumulated in 4 N-DNA G1 phase, and mitosis-specific kinases were inactivated in dependent on ATM/Chk1 after a short incubation for repair. We investigated whether or not mitotic DNA damage causes cells to skip-over late mitotic periods under prolonged incubation in a time-lapse study. 4 N-DNA-damaged cells re-replicated without cell division and accumulated in 8 N-DNA content, and the activities of apoptotic factors were increased. The inhibition of DNA replication reduced the 8 N-DNA cell population dramatically. Induction of replication without cell division was not observed upon depletion of Chk1 or ATM. Finally, mitotic DNA damage induces mitotic slippage and that cells enter G1 phase with 4 N-DNA content and then DNA replication is occurred to 8 N-DNA content before completion of mitosis in the ATM/Chk1-dependent manner, followed by caspase-dependent apoptosis during long-term repair. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. Photooxidative damage to mammalian cells and proteins by visible light

    International Nuclear Information System (INIS)

    Packer, L.; Kellogg, E.W. III

    1980-01-01

    In the present article, studies carried out in our laboratory on the effects of visible irradiation and O 2 in a variety of target systems ranging from cultured mammalian cells to purified catalase are reviewed. We will relate these studies of photooxidative damage to a scheme for the propagation of intracellular damage which traces a number of the possible pro-oxidant and anti-oxidant pathways found in the cell

  5. Photooxidative damage to mammalian cells and proteins by visible light

    Energy Technology Data Exchange (ETDEWEB)

    Packer, L.; Kellogg, E.W. III

    1980-01-01

    In the present article, studies carried out in our laboratory on the effects of visible irradiation and O/sub 2/ in a variety of target systems ranging from cultured mammalian cells to purified catalase are reviewed. We will relate these studies of photooxidative damage to a scheme for the propagation of intracellular damage which traces a number of the possible pro-oxidant and anti-oxidant pathways found in the cell.

  6. Orally Administrated Ascorbic Acid Suppresses Neuronal Damage and Modifies Expression of SVCT2 and GLUT1 in the Brain of Diabetic Rats with Cerebral Ischemia-Reperfusion

    Directory of Open Access Journals (Sweden)

    Naohiro Iwata

    2014-04-01

    Full Text Available Diabetes mellitus is known to exacerbate cerebral ischemic injury. In the present study, we investigated antiapoptotic and anti-inflammatory effects of oral supplementation of ascorbic acid (AA on cerebral injury caused by middle cerebral artery occlusion and reperfusion (MCAO/Re in rats with streptozotocin-induced diabetes. We also evaluated the effects of AA on expression of sodium-dependent vitamin C transporter 2 (SVCT2 and glucose transporter 1 (GLUT1 after MCAO/Re in the brain. The diabetic state markedly aggravated MCAO/Re-induced cerebral damage, as assessed by infarct volume and edema. Pretreatment with AA (100 mg/kg, p.o. for two weeks significantly suppressed the exacerbation of damage in the brain of diabetic rats. AA also suppressed the production of superoxide radical, activation of caspase-3, and expression of proinflammatory cytokines (tumor necrosis factor-α and interleukin-1β in the ischemic penumbra. Immunohistochemical staining revealed that expression of SVCT2 was upregulated primarily in neurons and capillary endothelial cells after MCAO/Re in the nondiabetic cortex, accompanied by an increase in total AA (AA + dehydroascorbic acid in the tissue, and that these responses were suppressed in the diabetic rats. AA supplementation to the diabetic rats restored these responses to the levels of the nondiabetic rats. Furthermore, AA markedly upregulated the basal expression of GLUT1 in endothelial cells of nondiabetic and diabetic cortex, which did not affect total AA levels in the cortex. These results suggest that daily intake of AA attenuates the exacerbation of cerebral ischemic injury in a diabetic state, which may be attributed to anti-apoptotic and anti-inflammatory effects via the improvement of augmented oxidative stress in the brain. AA supplementation may protect endothelial function against the exacerbated ischemic oxidative injury in the diabetic state and improve AA transport through SVCT2 in the cortex.

  7. Suppression of lymphocyte proliferation by marijuana components is related to cell number and cell source

    Energy Technology Data Exchange (ETDEWEB)

    Klein, T.; Pross, S.; Newton, C.; Friedman, H.

    1986-03-05

    Conflicting reports have appeared concerning the effect of marijuana components on immune responsiveness. The authors have observed that the effect of cannabinoids on lymphocyte proliferation varied with both the concentration of the drug and the mitogen used. They now report that at a constant concentration of drug, the cannabinoid effect varied from no effect to suppression depending upon the number of cells in culture and the organ source of the cells. Dispersed cell suspensions of mouse lymph node, spleen, and thymus were prepared and cultured at varying cell numbers with either delta-9-tetrahydrocannabinol or 11-hydroxy-delta-9-tetrahydrocannabinol and various mitogens. Lymphocyte proliferation was analyzed by /sup 3/H-thymidine incorporation. T-lymphocyte mitogen responses in cultures containing high cell numbers were unaffected by the cannabinoids but as cell numbers were reduced a suppression of the response was observed. Furthermore, thymus cells were considerably more susceptible to cannabinoid suppression than cells from either lymph node or spleen. These results suggest that certain lymphocyte subpopulations are more sensitive to cannabinoid suppression and that in addition to drug concentration other variables such as cell number and cell source must be considered when analyzing cannabinoid effects.

  8. Suppression of lymphocyte proliferation by marijuana components is related to cell number and cell source

    International Nuclear Information System (INIS)

    Klein, T.; Pross, S.; Newton, C.; Friedman, H.

    1986-01-01

    Conflicting reports have appeared concerning the effect of marijuana components on immune responsiveness. The authors have observed that the effect of cannabinoids on lymphocyte proliferation varied with both the concentration of the drug and the mitogen used. They now report that at a constant concentration of drug, the cannabinoid effect varied from no effect to suppression depending upon the number of cells in culture and the organ source of the cells. Dispersed cell suspensions of mouse lymph node, spleen, and thymus were prepared and cultured at varying cell numbers with either delta-9-tetrahydrocannabinol or 11-hydroxy-delta-9-tetrahydrocannabinol and various mitogens. Lymphocyte proliferation was analyzed by 3 H-thymidine incorporation. T-lymphocyte mitogen responses in cultures containing high cell numbers were unaffected by the cannabinoids but as cell numbers were reduced a suppression of the response was observed. Furthermore, thymus cells were considerably more susceptible to cannabinoid suppression than cells from either lymph node or spleen. These results suggest that certain lymphocyte subpopulations are more sensitive to cannabinoid suppression and that in addition to drug concentration other variables such as cell number and cell source must be considered when analyzing cannabinoid effects

  9. B cells exposed to enterobacterial components suppress development of experimental colitis

    DEFF Research Database (Denmark)

    Schmidt, Esben Gjerløff Wedebye; Larsen, Hjalte List; Kristensen, Nanna Ny

    2012-01-01

    ). RESULTS: We demonstrate that splenic B cells exposed to ebx produce large amounts of IL-10 in vitro and express CD1d and CD5 previously known to be associated with regulatory B cells. In SCID mice transplanted with colitogenic CD4(+) CD25(-) T cells, co-transfer of ebx-B cells significantly suppressed...... development of colitis. Suppression was dependent on B cell-derived IL-10, as co-transfer of IL-10 knockout ebx-B cells failed to suppress colitis. Ebx-B cell-mediated suppression of colitis was associated with a decrease in interferon gamma (IFN-¿)-producing T(H) 1 cells and increased frequencies of Foxp3......-expressing T cells. CONCLUSIONS: These data demonstrate that splenic B cells exposed to enterobacterial components acquire immunosuppressive functions by which they can suppress development of experimental T cell-mediated colitis in an IL-10-dependent way. (Inflamm Bowel Dis 2011;)....

  10. Endogenous suppression of mast cell development and survival by IL-4 and IL-10.

    Science.gov (United States)

    Speiran, Kelly; Bailey, Daniel P; Fernando, Josephine; Macey, Matthew; Barnstein, Brian; Kolawole, Motunrayo; Curley, Dana; Watowich, Stephanie S; Murray, Peter J; Oskeritzian, Carole; Ryan, John J

    2009-05-01

    Mast cell development is an important component of atopic and chronic inflammatory diseases such as asthma, multiple sclerosis, rheumatoid arthritis, and atherosclerosis. In this study, we found that IL-4 and IL-10 were produced constitutively in cultures of developing mast cells, correlating with mast cell purity. Deletion of either gene increased mast cell numbers and Fc epsilon RI expression during culture in IL-3 + stem cell factor (SCF). By adding exogenous IL-4 and IL-10 to bone marrow (BM) cultures containing IL-3 + SCF, we found that IL-4 + IL-10 suppressed mast cell development through mechanisms not used by either cytokine alone. IL-4 + IL-10 elicited a rapid cell death coincidental with reduced Kit receptor expression and signaling and enhanced mitochondrial damage and caspase activation. IL-4 or IL-10 costimulation, unlike either cytokine alone, altered mast cell ontogeny to yield predominantly macrophages in cultures that typically produce mast cells. This effect was observed consistently with unseparated BM cells, purified mouse BM stem cells, and erythrocyte-depleted human umbilical cord blood cells. These experiments demonstrated a major role for Stat6 and Stat3, but not the Stat3-induced transcriptional repressor Ets variant gene 3. Genetic background was also a critical factor, as BALB/c-derived BM cells were completely resistant to IL-10-mediated killing and expressed lower levels of IL-10R. Collectively, these results support the theory that IL-4 and IL-10 function as endogenous regulators of mast cell progenitor development, consistent with a role in immune homeostasis. Loss of this homeostasis, perhaps via genetic polymorphism, could contribute to the etiology of mast cell-associated disease.

  11. CD137 signaling suppresses the suppressive function of treg cells of peripheral blood from breast cancer patients

    International Nuclear Information System (INIS)

    Lu Tian; Jiang Linhua; ZZhang Chi; Sun Xuewei; Ju Songguang

    2009-01-01

    Objective: To explore the biological effect of CD137 and its molecular mechanism on CD4 + CD25 + Treg cells. Methods: Anti-CD137 mAb was added to stimulate the T cells that isolated from peripheral blood of breast cancer patients and activated by PHA. T cell proliferation was determined by cell counting or by 3 H-TdR incorporation assessing at the 3rd. The phenotype of cells was determined by FACS, and Foxp3 analysis was performed after fixation and intracellular staining. Cytokine in the supernatant was quantified with ELISA. Results: CD137 expressed on CD4 + CD25 + Treg cells. Triggering CD137 signaling of CD4 + CD25 + Treg cells by anti-CD137 mAb could promote the proliferation of T cells form PBMCs of breast cancer patients and decrease the ratio of Foxp3 + Treg population and reduce Foxp3 expression of Treg cells, as well as the production of TGF-β1 and IL-10, and suppress the ability of Treg cells to inhibit proliferation of CD4 + CD25 - T cells. Conclusion: CD137 signaling could suppress the suppressive function of Treg cells, and CD137 might be a potential molecular target for the immunological interference. (authors)

  12. Gallium Arsenide solar cell radiation damage experiment

    Science.gov (United States)

    Maurer, R. H.; Kinnison, J. D.; Herbert, G. A.; Meulenberg, A.

    1991-01-01

    Gallium arsenide (GaAs) solar cells for space applications from three different manufactures were irradiated with 10 MeV protons or 1 MeV electrons. The electrical performance of the cells was measured at several fluence levels and compared. Silicon cells were included for reference and comparison. All the GaAs cell types performed similarly throughout the testing and showed a 36 to 56 percent power areal density advantage over the silicon cells. Thinner (8-mil versus 12-mil) GaAs cells provide a significant weight reduction. The use of germanium (Ge) substrates to improve mechanical integrity can be implemented with little impact on end of life performance in a radiation environment.

  13. Valvular interstitial cells suppress calcification of valvular endothelial cells

    NARCIS (Netherlands)

    Hjortnaes, Jesper; Shapero, Kayle; Goettsch, Claudia; Hutcheson, Joshua D; Keegan, Joshua; Kluin, J; Mayer, John E; Bischoff, Joyce; Aikawa, Elena

    BACKGROUND: Calcific aortic valve disease (CAVD) is the most common heart valve disease in the Western world. We previously proposed that valvular endothelial cells (VECs) replenish injured adult valve leaflets via endothelial-to-mesenchymal transformation (EndMT); however, whether EndMT contributes

  14. Mycoplasma Suppression of THP-1 Cell TLR Responses Is Corrected with Antibiotics

    OpenAIRE

    Zakharova, Ekaterina; Grandhi, Jaykumar; Wewers, Mark D.; Gavrilin, Mikhail A.

    2010-01-01

    Mycoplasma contamination of cultured cell lines is a serious problem in research, altering cellular response to different stimuli thus compromising experimental results. We found that chronic mycoplasma contamination of THP-1 cells suppresses responses of THP-1 cells to TLR stimuli. For example, E. coli LPS induced IL-1 beta was suppressed by 6 fold and IL-8 by 10 fold in mycoplasma positive THP-1 cells. Responses to live F. novicida challenge were suppressed by 50-fold and 40-fold respective...

  15. Aging of hematopoietic stem cells: DNA damage and mutations?

    Science.gov (United States)

    Moehrle, Bettina M; Geiger, Hartmut

    2016-10-01

    Aging in the hematopoietic system and the stem cell niche contributes to aging-associated phenotypes of hematopoietic stem cells (HSCs), including leukemia and aging-associated immune remodeling. Among others, the DNA damage theory of aging of HSCs is well established, based on the detection of a significantly larger amount of γH2AX foci and a higher tail moment in the comet assay, both initially thought to be associated with DNA damage in aged HSCs compared with young cells, and bone marrow failure in animals devoid of DNA repair factors. Novel data on the increase in and nature of DNA mutations in the hematopoietic system with age, the quality of the DNA damage response in aged HSCs, and the nature of γH2AX foci question a direct link between DNA damage and the DNA damage response and aging of HSCs, and rather favor changes in epigenetics, splicing-factors or three-dimensional architecture of the cell as major cell intrinsic factors of HSCs aging. Aging of HSCs is also driven by a strong contribution of aging of the niche. This review discusses the DNA damage theory of HSC aging in the light of these novel mechanisms of aging of HSCs. Copyright © 2016 ISEH - International Society for Experimental Hematology. Published by Elsevier Inc. All rights reserved.

  16. Expression of assayable residual stem cell damage in erythroid differentiation

    International Nuclear Information System (INIS)

    Huebner, G.E.; Miller, M.E.; Cronkite, E.P.

    1985-01-01

    In rodents, residual damage is inducible in hematopoietic stem cells by exposure to ionizing radiation or alkylating agents. This damage can b e assayed in mice by transferring bone marrow into lethally irradiated syngeneic recipients and subsequently measuring the incremental increase of-( 125 I)iodo-2'-deoxyuridine incorporation in spleens. In this study, bone marrow from mice treated 3 weeks previously with Methylnitrosourea (50 mg/kg) or 450 rad was injected into recipients in order to determine possible residual effects of treatment of erythroid cell differentiation following stem cell seeding. Such effects were detected by a reduced amount of 59 Fe incorporation into spleens, thus indicatin g transfer of residual stem cell damage to differentiating cells. (orig.)

  17. Primary radiation damage and disturbance in cell divisions

    International Nuclear Information System (INIS)

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

    2008-01-01

    Survived cells from a homogeneous population exposed to ionizing radiation form various colonies of different sizes and morphology on a solid nutrient medium, which appear at different time intervals after irradiation. Such a phenomenon agrees well with the modern theory of microdosimetry and classical hit-and-target models of radiobiology. According to the hit-principle, individual cells exposed to the same dose of radiation are damaged in different manners. It means that the survived cells can differ in the content of sublethal damage (hits) produced by the energy absorbed into the cell and which is not enough to give rise to effective radiation damage which is responsible for cell killing or inactivation. In diploid yeast cells, the growth rate of cells from 250 colonies of various sizes appeared at different time intervals after irradiation with 600 Gy of gamma radiation from a 60 Co isotopic source was analyzed. The survival rate after irradiation was 20%. Based on the analyses results, it was possible to categorize the clones grown from irradiated cells according to the number of sub-lesions from 1 to 4. The clones with various numbers of sub-lesions were shown to be different in their viability, radiosensitivity, sensitivity to environmental conditions, and the frequency of recombination and respiratory deficient mutations. Cells from unstable clones exhibited an enhanced radiosensitivity, and an increased portion of morphologically changed cells, nonviable cells and respiration mutants, as well. The degree of expression of the foregoing effects was higher if the number of primary sublethal lesions was greater in the originally irradiated cell. Disturbance in cell division can be characterized by cell inactivation or incorrect distribution of mitochondria between daughter cells. Thus, the suggested methodology of identification of cells with a definite number of primary sublethal lesions will promote further elucidation of the nature of primary radiation

  18. Ascorbate induces apoptosis in melanoma cells by suppressing Clusterin expression.

    Science.gov (United States)

    Mustafi, Sushmita; Sant, David W; Liu, Zhao-Jun; Wang, Gaofeng

    2017-06-16

    Pharmacological levels of ascorbate have long been suggested as a potential treatment of cancer. However, we observed that EC50 of ascorbate was at a similar level for cultured healthy melanocytes and melanoma cells, suggesting a limit of pharmacological ascorbate in treating cancer. Loss of 5-hydroxymethylcytosine (5 hmC) is an epigenetic hallmark of cancer and ascorbate promotes 5 hmC generation by serving as a cofactor for TET methylcytosine dioxygenases. Our previous work demonstrated that ascorbate treatment at physiological level (100 μM) increased 5 hmC content in melanoma cells toward the level of healthy melanocytes. Here we show that 100 µM of ascorbate induced apoptosis in A2058 melanoma cells. RNA-seq analysis revealed that expression of the Clusterin (CLU) gene, which is related to apoptosis, was downregulated by ascorbate. The suppression of CLU was verified at transcript level in different melanoma cell lines, and at protein level in A2058 cells. The anti-apoptotic cytoplasmic CLU was decreased, while the pro-apoptotic nuclear CLU was largely maintained, after ascorbate treatment. These changes in CLU subcellular localization were also associated with Bax and caspases activation, Bcl-xL sequestration, and cytochrome c release. Taken together, this study establishes an impending therapeutic role of physiological ascorbate to potentiate apoptosis in melanoma.

  19. Neuron-mediated generation of regulatory T cells from encephalitogenic T cells suppresses EAE

    DEFF Research Database (Denmark)

    Liu, Yawei; Teige, Ingrid; Birnir, Bryndis

    2006-01-01

    ) inflammation. Neurons induce the proliferation of activated CD4+ T cells through B7-CD28 and transforming growth factor (TGF)-beta1-TGF-beta receptor signaling pathways, resulting in amplification of T-cell receptor signaling through phosphorylated ZAP-70, interleukin (IL)-2 and IL-9. The interaction between......Neurons have been neglected as cells with a major immune-regulatory function because they do not express major histocompatibility complex class II. Our data show that neurons are highly immune regulatory, having a crucial role in governing T-cell response and central nervous system (CNS...... neurons and T cells results in the conversion of encephalitogenic T cells to CD25+ TGF-beta1+ CTLA-4+ FoxP3+ T regulatory (Treg) cells that suppress encephalitogenic T cells and inhibit experimental autoimmune encephalomyelitis. Suppression is dependent on cytotoxic T lymphocyte antigen (CTLA)-4...

  20. Protective effects of fluoroquinolones on UV-induced damage of cultured ocular cell lines.

    Science.gov (United States)

    Nishida, Takashi; Kuse, Yoshiki; Mochizuki, Kiyofumi; Shimazawa, Masamitsu; Yamamoto, Tetsuya; Hara, Hideaki

    2017-07-05

    Although the fluoroquinolones have strong antibacterial effects, some of them also have adverse ocular effects such as diplopia, uveitis, optic neuropathy, and retinal detachment. The purpose of this study was to determine whether low concentrations of fluoroquinolones can lessen the cytotoxic effects of ultraviolet (UV) light on different kinds of cultured ocular cells. We studied cultured human corneal endothelial cells (HCECs), a retinal ganglion cell line (RGC-5), a mouse-derived photoreceptor cell line (661W), a human adult retinal pigment epithelial cell line (ARPE-19), primary retinal cells, and primary human RPE cells. Levofloxacin, ciprofloxacin, and clinafloxacin were selected as the fluoroquinolones to test. The viabilities of the 661W, ARPE-19, and hRPE cells were assessed by Cell Counting Kit-8, and that of HCECs, 661W cells, and ARPE-19 cells by double fluorescent staining with Hoechst 33342 and propidium iodide (PI). Damage of retinal primary culture cells was assessed by immunostaining. Intracellular production of reactive oxygen species was measured in ARPE-19 cells by CM-H 2 DCFDA after UV light exposure. An activation of caspase by UV light in ARPE-19 cells was detected with a caspase-3/7 assay kit. UV exposure increased the number of dead cells, and the three fluoroquinolones tested suppressed this increase. Fluoroquinolones also protected the cells against the hydroxyperoxide (H 2 O 2 )-induced cell damage. Moreover, the fluoroquinolones decreased the production of reactive oxygen species and the activity of caspase-3/7, and low concentrations of fluoroquinolones reduced the oxidative stress in cultured ocular cell lines. We conclude that fluoroquinolones may have protective effects in these cells against UV exposure. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Burn injury suppresses human dermal dendritic cell and Langerhans cell function

    NARCIS (Netherlands)

    van den Berg, Linda M.; de Jong, Marein A. W. P.; Witte, Lot de; Ulrich, Magda M. W.; Geijtenbeek, Teunis B. H.

    2011-01-01

    Human skin contains epidermal Langerhans cells (LCs) and dermal dendritic cells (DCs) that are key players in induction of adaptive immunity upon infection. After major burn injury, suppressed adaptive immunity has been observed in patients. Here we demonstrate that burn injury affects adaptive

  2. Albumin Suppresses Human Hepatocellular Carcinoma Proliferation and the Cell Cycle

    Directory of Open Access Journals (Sweden)

    Shunsuke Nojiri

    2014-03-01

    (+, Prionex, respectively. The same results were obtained in HepG2. Cell proliferation was inhibited in 5 g/dL albumin medium in both HepG2 cells and Hep3B cells in 24 h culture by counting cell numbers. The presence of albumin in serum reduces the phosphorylation of Rb proteins and enhances the expression of p21 and p57, following an increase in the G0/G1 cell population, and suppresses cell proliferation. These results suggest that albumin itself suppresses the proliferation of hepatocellular carcinoma.

  3. Profiling of Sox4-dependent transcriptome in skin links tumour suppression and adult stem cell activation

    Directory of Open Access Journals (Sweden)

    Miguel Foronda

    2015-12-01

    Full Text Available Adult stem cells (ASCs reside in specific niches in a quiescent state in adult mammals. Upon specific cues they become activated and respond by self-renewing and differentiating into newly generated specialised cells that ensure appropriate tissue fitness. ASC quiescence also serves as a tumour suppression mechanism by hampering cellular transformation and expansion (White AC et al., 2014. Some genes restricted to early embryonic development and adult stem cell niches are often potent modulators of stem cell quiescence, and derailed expression of these is commonly associated to cancer (Vervoort SJ et al., 2013. Among them, it has been shown that recommissioned Sox4 expression facilitates proliferation, survival and migration of malignant cells. By generating a conditional Knockout mouse model in stratified epithelia (Sox4cKO mice, we demonstrated a delayed plucking-induced Anagen in the absence of Sox4. Skin global transcriptome analysis revealed a prominent defect in the induction of transcriptional networks that control hair follicle stem cell (HFSC activation such as those regulated by Wnt/Ctnnb1, Shh, Myc or Sox9, cell cycle and DNA damage response-associated pathways. Besides, Sox4cKO mice are resistant to skin carcinogenesis, thus linking Sox4 to both normal and pathological HFSC activation (Foronda M et al., 2014. Here we provide additional details on the analysis of Sox4-regulated transcriptome in Telogen and Anagen skin. The raw and processed microarray data is deposited in GEO under GSE58155.

  4. Radiation damage and repair in cells and cell components. Progress report, 1978-1979

    Energy Technology Data Exchange (ETDEWEB)

    Fluke, D.J.; Pollard, E.C.

    1979-01-01

    Special work during the year concentrated on induced repair of cellular radiation damage in a number of strains of Escherchia coli. Ultraviolet and x-radiation are considered for induction of cell damage. (PCS)

  5. Dietary compounds galangin and myricetin suppress ovarian cancer cell angiogenesis.

    Science.gov (United States)

    Huang, Haizhi; Chen, Allen Y; Rojanasakul, Yon; Ye, Xingqian; Rankin, Gary O; Chen, Yi Charlie

    2015-05-01

    Galangin and myricetin are flavonoids isolated from vegetables and fruits which exhibit anti-proliferative activity in human cancer cells. In this study, their anti-angiogenic effects were investigated with in vitro (HUVEC) and in vivo (CAM) models, which showed that galangin and myricetin inhibited angiogenesis induced by OVCAR-3 cells. The molecular mechanisms through which galangin and myricetin suppress angiogenesis were also studied. It was observed that galangin and myricetin inhibited secretion of the key angiogenesis mediator vascular endothelial growth factor (VEGF) and decreased levels of p-Akt, p-70S6K and hypoxia-inducible factor-1α (HIF-1α) proteins in A2780/CP70 and OVCAR-3 cells. Transient transfection experiments showed that galangin and myricetin inhibited secretion of VEGF by the Akt/p70S6K/ HIF-1α pathway. Moreover, a novel pathway, p21/HIF-1α/VEGF, was found to be involved in the inhibitory effect of myricetin on angiogenesis in OVCAR-3 cells. These data suggest that galangin and myricetin might serve as potential anti-angiogenic agents in the prevention of ovarian cancers dependent on new blood vessel networks.

  6. Recovery of cytogenetic damage in plant cells with unequal fractionation of damaging action. 2. Sparsely ionizing radiation effect

    Energy Technology Data Exchange (ETDEWEB)

    Stepanyan, N.S.; Seregina, T.V.; Krupnova, G.F.; Zhestyanikov, V.D. (AN SSSR, Leningrad. Inst. Tsitologii)

    1984-01-01

    In case of unequal fractionation of X-irradiation dose (1, 6 and 3 Gy) in Vicia faba cells the fractionation effect (decrease of chromosomal breaks frequency as compared with their frequency in case of non fractionated effect total in dose) takes place in cells being at the irradiation moment mostly in the S phase, but is not observed in case of irradiation of cells being mostly in the G/sub 2/ phase. Introduction in cells in the interval between fractions of chloramphenical protein synthesis inhibitor increases the chromosomal aberrations frequency in the G/sub 2/ phase cells (in the S phase in irradiated cells the antibiotic blocks up the advance of cells by cycle) only at irradiation in integral dose 1.6 Gy. The strengthening of damaging radiation effect by chloramphenicol is observed in case of its combination with caffeine, DNA reparation inhibitor, however on no account the combination effect exceeds the total sum of both agents effects. In case of non-uniform fractionation of gamma irradiation the treatment of V. faba cells by chloramphenicol in the interval between fractions leads to a slight but certain reparation attenuation of DNA one-strand ruptures. Inhibitor treatment before irradiation in non fractionated total dose sharply suppresses and after irradiation does not change the DNA one-strand breaks reparation. The data testify that in V faba cells in case of sparsely ionizing radiation effect probably the DNA inducible DNA reparation functionates which is responsible for elimination of a small number of DNA one-strand ruptures and a certain part of chromosomal aberrations.

  7. Development of rat embryonic spinal ganglion cells in damaged nerve.

    Science.gov (United States)

    Petrova, E S; Isaeva, E N; Korzhevskii, D E

    2014-09-01

    The development of dissociated cells from rat embryonic spinal ganglion after transplantation to damaged nerve of adult animals was studied using immunohistochemical differentiation markers of neural and glial cells. The cell suspension obtained after dissociation of rat embryonic spinal ganglia (embryonic day 15) was injected into the proximal segment of crushed sciatic nerve. The nerve was damaged by ligation for 40 sec. Progenitor cells were labeled with 5-bromo-2'-deoxyuridine (BrdU) before transplantation. BrdU-immunopositive cells were detected in the nerve trunks of recipients on days 1, 21, and 28 after transplantation. Dissociated cells of rat embryonic spinal ganglion (embryonic day 15) survived for at least 4 weeks after transplantation to the nerve and differentiate into NeuN-immunopositive neurons with morphological properties of sensory neurons and satellite cells containing S100 protein.

  8. Hyperglycemia induces oxidative damage in SW872 cells | Boyer ...

    African Journals Online (AJOL)

    Using real time quantitative PCR, enhanced HMGB1 mRNA expressions were evidenced in hyperglycemic-‐treated SW872 cell line. Our data clearly indicate that hyperglycemia treatments result in an increase in oxidative damage in SW872 cell lines that may affect its functionality. Oxidative stress drives the activation of ...

  9. Sunlight-induced DNA damage in human mononuclear cells

    DEFF Research Database (Denmark)

    Møller, Peter; Wallin, Hakan; Holst, Erik

    2002-01-01

    to blood sampling. The 3 and 6 day periods before sampling influenced DNA damage the most. The importance of sunlight was further emphasized by a positive association of the DNA damage level to the amount of time the subjects had spent in the sun over a 3 day period prior to the sampling. The effect......In this study of 301 blood samples from 21 subjects, we found markedly higher levels of DNA damage (nonpyrimidine dimer types) in the summer than in the winter detected by single-cell gel electrophoresis. The level of DNA damage was influenced by the average daily influx of sunlight ... of sunlight was comparable to the interindividual variation, indicating that sunlight exposure and the individual's background were the two most important determinants for the basal level of DNA damage. Influence of other lifestyle factors such as exercise, intake of foods, infections, and age could...

  10. Andrographolide sensitizes cisplatin-induced apoptosis via suppression of autophagosome-lysosome fusion in human cancer cells.

    Science.gov (United States)

    Zhou, Jing; Hu, Shuai-Er; Tan, Shi-Hao; Cao, Ruoxi; Chen, Yiyang; Xia, Dajing; Zhu, Xinqiang; Yang, Xing-Fen; Ong, Choon-Nam; Shen, Han-Ming

    2012-03-01

    Suppression of autophagy has been increasingly recognized as a novel cancer therapeutic approach. Andrographolide (Andro), a diterpenoid lactone isolated from an herbal plant Andrographis paniculata, is known to possess anti-inflammatory and anticancer activity. In this study, we sought to examine the effect of Andro on autophagy, and to evaluate whether such effect is relevant to the sensitization effect of Andro on apoptosis induced by DNA damage agents in cancer cells. First, we found that Andro is able to significantly enhance autophagic markers in various cancer cell lines, including GFP-LC3 puncta and LC3-II level. Interestingly, Andro treatment also led to marked increase of p62 protein level and addition of chloroquine (CQ) failed to further enhance either LC3-II or p62 level, indicating that Andro is likely to suppress autophagic flux at the maturation and degradation stage. Next, we provided evidence that Andro inhibits autophagosome maturation not by affecting the lysosomal function, but by impairing autophagosome-lysosome fusion. Lastly, we demonstrated that treatment with cisplatin, a DNA damage agent, induces autophagy in cancer cells. Importantly, Andro is capable of sensitizing cisplatin-induced cell killing determined with both short-term apoptosis assays and long-term clonogenic test, via suppression of autophagy, a process independent of p53. In summary, these observations collectively suggest that Andro could be a promising anti-cancer agent in combination therapy via its potent inhibitory effect on autophagy by disrupting autophagosome-lysosome fusion.

  11. Sulphonated hypocrellin B sensitized photo damage to ascetic hepatoma cells

    International Nuclear Information System (INIS)

    Yue Jiachang; Wang Tiandun; Pang Suzhen; An Jingyi; Jiang Lijing

    1994-01-01

    The cellular uptake of sulphonated hypocrellin (S-HB), as well as photo damage on cellular viability, lipid peroxidation and intrinsic fluorescence quenching of membrane protein was studied. It was found that S-HB suitable dissolved in aqueous solution, its cellular uptake is slower than HB. The photo damage on cellular viability both photo sensitizers was close to each other, however the photo sensitizers were different in physical and chemical properties. The HB photo damage target of cells was membrane, but the sulphonated HB photo damage target of cells may be part of organelles, besides the membrane. the experiments showed the sulphonated HB would be suggested as a potential advantage for photodynamic therapy of tumor in clinical application

  12. Induction of ROS Overload by Alantolactone Prompts Oxidative DNA Damage and Apoptosis in Colorectal Cancer Cells

    Directory of Open Access Journals (Sweden)

    Yushuang Ding

    2016-04-01

    Full Text Available Cancer cells typically display higher than normal levels of reactive oxygen species (ROS, which may promote cancer development and progression but may also render the cancer cells more vulnerable to further ROS insult. Indeed, many of the current anticancer therapeutics kill cancer cells via induction of oxidative stress, though they target both cancer and normal cells. Recently, alantolactone (ATL, a natural sesquiterpene lactone, has been shown to induce apoptosis by increasing ROS levels specifically in cancer cells; however, the molecular mechanisms linking ROS overproduction to apoptosis remain unclear. Here we show that the ATL-induced ROS overload in human SW480 and SW1116 colorectal cancer cells was followed by a prominent accumulation of cellular oxidized guanine (8-oxoG and immediate increase in the number of DNA strand breaks, indicating that increased ROS resulted in extensive oxidative DNA damage. Consequently, the G1/S-CDK suppresser CDKN1B (p21 and pro-apoptotic proteins Bax and activated caspase-3 were upregulated, while anti-apoptotic Bcl-2 was downregulated, which were followed by cell cycle arrest at G1 and marked apoptosis in ATL-treated cancer but not non-cancer cells. These results suggest that the ATL-induced ROS overload triggers cell death through induction of massive oxidative DNA damage and subsequent activation of the intrinsic apoptosis pathway.

  13. Continuous cytokine exposure of colonic epithelial cells induces DNA damage

    DEFF Research Database (Denmark)

    Seidelin, Jakob B; Nielsen, Ole Haagen

    2005-01-01

    Chronic inflammatory diseases of the intestinal tract are associated with an increased risk of colorectal cancer. As an example ulcerative colitis (UC) is associated with a production of reactive oxygen species (ROS), including nitrogen monoxide (NO), which is produced in high amounts by inducibl...... nitrogen oxide synthase (iNOS). NO as well as other ROS are potential DNA damaging agents. The aim was to determine the effect of long-term cytokine exposure on NO formation and DNA damage in epithelial cells....

  14. Bixin protects hepatocytes against 1,2-dimethylhydrazine-induced genotoxicity but does not suppress DNA damage and pre-neoplastic lesions in the colon of Wistar rats.

    Science.gov (United States)

    de Oliveira, Pollyanna Francielli; de Andrade, Kelly Jacqueline Barbosa; Paula, Marcela Cristina Ferreira; Oliveira Acésio, Nathália; da Silva Moraes, Thais; Borges, Priscilla Scalon Freitas; Barcelos, Gustavo Rafael Mazzaron; Tavares, Denise Crispim

    2014-01-01

    Bixin is a carotenoid found in the seeds of Bixa orellana L., a plant native to tropical America that is used in the food industry. The aim of this study was to investigate the effect of bixin on DNA damage and pre-neoplastic lesions induced by 1,2-dimethylhydrazine (DMH) in the liver and colon of Wistar rats. The animals received bixin at daily doses of 0.1, 1.0 and 10mg/kg body weight (bw) by gavage. For the assessment of DNA damage in hepatocytes and colon cells with the comet assay, the administration of bixin was for 7 days. The animals received a single subcutaneous injection of 25mg/kg bw of DMH, and were euthanized 4h later. For the evaluation of the frequency of aberrant crypt foci (ACF), the animals were treated with the different doses of bixin for 4 weeks. Four doses of 40mg/kg bw DMH, two doses in the first week and two doses in the second week, were administered and euthanasia occurred at 4 weeks after the beginning of treatment. Bixin reduced the frequency of DNA damage in hepatocytes at the highest two doses tested (1.0 and 10mg/kg bw). On the other hand, no differences in the frequency of DNA damage in colon cells were observed between animals treated with bixin plus DMH and those treated with DMH alone. In addition, the frequency of ACF did not differ significantly between the group treated with bixin plus DMH and the DMH group. The results suggest that bixin does not suppress the formation of ACF, indicating the absence of a protective effect against colon carcinogenesis. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Helichrysetin Induces DNA Damage that Triggers JNK-Mediated Apoptosis in Ca Ski Cells.

    Science.gov (United States)

    Fong, Ho Yen; Abd Malek, Sri Nurestri; Yee, Hui Shin; Karsani, Saiful Anuar

    2017-01-01

    Cervical cancer has become one of the most common cancers in women and currently available treatment options for cervical cancer are very limited. Naturally occurring chalcones and its derivatives have been studied extensively as a potential anticancer agent in different types of cancer and helichrysetin is naturally occurring chalcone that possess potent antiproliferative activity toward human cancer cells. Inhibitory activity of helichrysetin was evaluated at different concentrations. Ability of helichrysetin to induce apoptosis and its relation with c-Jun N-terminal kinase (JNK)-mediated mechanism of apoptosis was assessed using flow cytometry and Western blotting. Helichrysetin inhibited Ca Ski cells at half maximal inhibitory concentration 30.62 ± 0.38 μM. This compound has the ability to induce DNA damage, mitochondrial membrane disruption, and loss of cell membrane integrity. We have shown that apoptosis was induced through the activation of JNK-mediated apoptosis by DNA damage in the cells then triggering p53-downstream apoptotic pathway with increased expression of pro-apoptotic proteins, Bax and caspase 3, and suppression of Bcl-2 anti-apoptotic protein. DNA damage in the cells also caused phosphorylation of protein ataxia-telangiectasia mutated, an activator of DNA damage response. We conclude that helichrysetin can inhibit Ca Ski cells through DNA damage-induced JNK-mediated apoptotic pathway highlighting the potential of this compound as anticancer agent for cervical cancer. Helichrysetin induced DNA damage in Ca Ski cellsDNA damage caused JNK-mediated phosphorylation of p53 resulting in p53-mediated apoptosisHelichrysetin is a potential DNA damage inducing agent through JNK activation to kill human cervical carcinoma cells. Abbreviations used: ATM: Ataxia-telangiectasia mutated, DAPI: 4',6-diamidino-2-phenylindole, DMSO: Dimethyl sulfoxide, FITC: Fluorescein isothiocyanate, IC 50 : Half maximal inhibitory concentration, JC1-5,5',6,6'-Tetrachloro: 1

  16. Resveratrol Induces Premature Senescence in Lung Cancer Cells via ROS-Mediated DNA Damage

    Science.gov (United States)

    Luo, Hongmei; Yang, Aimin; Schulte, Bradley A.; Wargovich, Michael J.; Wang, Gavin Y.

    2013-01-01

    Resveratrol (RV) is a natural component of red wine and grapes that has been shown to be a potential chemopreventive and anticancer agent. However, the molecular mechanisms underlying RV's anticancer and chemopreventive effects are incompletely understood. Here we show that RV treatment inhibits the clonogenic growth of non-small cell lung cancer (NSCLC) cells in a dose-dependent manner. Interestingly, the tumor-suppressive effect of low dose RV was not associated with any significant changes in the expression of cleaved PARP and activated caspase-3, suggesting that low dose RV treatment may suppress tumor cell growth via an apoptosis-independent mechanism. Subsequent studies reveal that low dose RV treatment induces a significant increase in senescence-associated β–galactosidase (SA-β-gal) staining and elevated expression of p53 and p21 in NSCLC cells. Furthermore, we show that RV-induced suppression of lung cancer cell growth is associated with a decrease in the expression of EF1A. These results suggest that RV may exert its anticancer and chemopreventive effects through the induction of premature senescence. Mechanistically, RV-induced premature senescence correlates with increased DNA double strand breaks (DSBs) and reactive oxygen species (ROS) production in lung cancer cells. Inhibition of ROS production by N-acetylcysteine (NAC) attenuates RV-induced DNA DSBs and premature senescence. Furthermore, we show that RV treatment markedly induces NAPDH oxidase-5 (Nox5) expression in both A549 and H460 cells, suggesting that RV may increase ROS generation in lung cancer cells through upregulating Nox5 expression. Together, these findings demonstrate that low dose RV treatment inhibits lung cancer cell growth via a previously unappreciated mechanism, namely the induction of premature senescence through ROS-mediated DNA damage. PMID:23533664

  17. MRI assessment of suppression of structural damage in patients with rheumatoid arthritis receiving rituximab

    DEFF Research Database (Denmark)

    Peterfy, Charles; Emery, Paul; Tak, Paul P

    2016-01-01

    Objective. To evaluate changes in structural damage and joint inflammation assessed by MRI following rituximab treatment in a Phase 3 study of patients with active rheumatoid arthritis (RA) despite methotrexate (MTX) who were naive to biological therapy. Methods. Patients were randomised to receive...... baseline at week 24. Results. Patients treated with rituximab demonstrated significantly less progression in the mean MRI erosion score compared with those treated with placebo at weeks 24 (0.47, 0.18 and 1.60, respectively, p=0.003 and p=0.001 for the two rituximab doses vs placebo) and 52 (-0.30, 0...... further at weeks 24 and 52. Conclusions. This study demonstrated that rituximab significantly reduced erosion and cartilage loss at week 24 and week 52 in MTX-inadequate responder patients with active RA, suggesting that MRI is a valuable tool for assessing inflammatory and structural damage in patients...

  18. Hydroxytyrosol Protects against Oxidative DNA Damage in Human Breast Cells

    Directory of Open Access Journals (Sweden)

    José J. Gaforio

    2011-10-01

    Full Text Available Over recent years, several studies have related olive oil ingestion to a low incidence of several diseases, including breast cancer. Hydroxytyrosol and tyrosol are two of the major phenols present in virgin olive oils. Despite the fact that they have been linked to cancer prevention, there is no evidence that clarifies their effect in human breast tumor and non-tumor cells. In the present work, we present hydroxytyrosol and tyrosol’s effects in human breast cell lines. Our results show that hydroxytyrosol acts as a more efficient free radical scavenger than tyrosol, but both fail to affect cell proliferation rates, cell cycle profile or cell apoptosis in human mammary epithelial cells (MCF10A or breast cancer cells (MDA-MB-231 and MCF7. We found that hydroxytyrosol decreases the intracellular reactive oxygen species (ROS level in MCF10A cells but not in MCF7 or MDA-MB-231 cells while very high amounts of tyrosol is needed to decrease the ROS level in MCF10A cells. Interestingly, hydroxytyrosol prevents oxidative DNA damage in the three breast cell lines. Therefore, our data suggest that simple phenol hydroxytyrosol could contribute to a lower incidence of breast cancer in populations that consume virgin olive oil due to its antioxidant activity and its protection against oxidative DNA damage in mammary cells.

  19. Modification of the repair of potentially lethal damage in plateau-phase Chinese hamster cells by 2-chlorodeoxyadenosine

    International Nuclear Information System (INIS)

    Tanabe, Kiyoshi; Hiraoka, Wakako; Kuwabara, Mikinori; Matsuda, Akira; Ueda, Tohru; Sato, Fumiaki.

    1988-01-01

    The ability of 2-chlorodeoxyadenosine, a ribonucleotide reductase inhibitor, to inhibit the repair of potentially lethal damage was demonstrated in Chinese hamster V79 cells after X irradiation in plateau-phase cultures. This ability of the drug was completely diminished when deoxycytidine was added at the same time, though this was slightly affected by the addition of adenosine, suggesting that this drug was phosphorylated by deoxycytidine kinase to serve as an inhibitor of the repair of potentially lethal damage. Compared with hydroxyurea, another ribonucleotide reductase inhibitor, this drug appeared to contain its own activity which suppressed the repair of potentially lethal damage. A combined study of post-irradiation treatment with hypertonic salt solution and with this drug on the fixation of potentially lethal damage revealed that this drug inhibited the repair of hypertonic-insensitive potentially lethal damage. (author)

  20. Cell membrane damage by iron nanoparticles: an invitro study

    Directory of Open Access Journals (Sweden)

    Gelare Hajsalimi

    2016-12-01

    Full Text Available Application of nanotechnology in medicinal and biological fields has attracted a great interest in the recent yeras. In this paper the cell membrane leakage induced by iron nanoparticles (Fe-NP against PC12 cell line which is known as a model of nervous system cell line was investigated by the lactate dehydrogenase (LDH test. Therefore, PC12 cells were incubated with different concentration of Fe-NP and test was performed after 48h of incubation of the cells with Fe-NP. The resulting data showed that the Fe-NP induced the damage of PC12 cell membrane in a concentration dependent manner. Hence, it may be concluded that the different cytotoxicty effect of NPs may be referred to the concentration of NPs, type of the NPs and the cells. Indeed, the kind of cytotoxic impacts of NPs on the cells can be reduced by the considering of above-mentioned parameters. The resulting data showed that the Fe-NP induced the damage of PC12 cell membrane in a concentration dependent manner. Hence, it may be concluded that the different cytotoxicty effect of NPs may be referred to the concentration of NPs, type of the NPs and the cells. Indeed, the kind of cytotoxic impacts of NPs on the cells can be reduced by the considering of above-mentioned parameters.

  1. E2F/DP Prevents Cell-Cycle Progression in Endocycling Fat Body Cells by Suppressing dATM Expression.

    Science.gov (United States)

    Guarner, Ana; Morris, Robert; Korenjak, Michael; Boukhali, Myriam; Zappia, Maria Paula; Van Rechem, Capucine; Whetstine, Johnathan R; Ramaswamy, Sridhar; Zou, Lee; Frolov, Maxim V; Haas, Wilhelm; Dyson, Nicholas J

    2017-12-18

    To understand the consequences of the complete elimination of E2F regulation, we profiled the proteome of Drosophila dDP mutants that lack functional E2F/DP complexes. The results uncovered changes in the larval fat body, a differentiated tissue that grows via endocycles. We report an unexpected mechanism of E2F/DP action that promotes quiescence in this tissue. In the fat body, dE2F/dDP limits cell-cycle progression by suppressing DNA damage responses. Loss of dDP upregulates dATM, allowing cells to sense and repair DNA damage and increasing replication of loci that are normally under-replicated in wild-type tissues. Genetic experiments show that ectopic dATM is sufficient to promote DNA synthesis in wild-type fat body cells. Strikingly, reducing dATM levels in dDP-deficient fat bodies restores cell-cycle control, improves tissue morphology, and extends animal development. These results show that, in some cellular contexts, dE2F/dDP-dependent suppression of DNA damage signaling is key for cell-cycle control and needed for normal development. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. The Potent Humanin Analogue (HNG) Protects Germ Cells and Leucocytes While Enhancing Chemotherapy-Induced Suppression of Cancer Metastases in Male Mice.

    Science.gov (United States)

    Lue, YanHe; Swerdloff, Ronald; Wan, Junxiang; Xiao, Jialin; French, Samuel; Atienza, Vince; Canela, Victor; Bruhn, Kevin W; Stone, Brian; Jia, Yue; Cohen, Pinchas; Wang, Christina

    2015-12-01

    Humanin is a peptide that is cytoprotective against stresses in many cell types. We investigated whether a potent humanin analogue S14G-humanin (HNG) would protect against chemotherapy-induced damage to normal cells without interfering with the chemotherapy-induced suppression of cancer cells. Young adult male mice were inoculated iv with murine melanoma cells. After 1 week, cancer-bearing mice were randomized to receive either: no treatment, daily ip injection of HNG, a single ip injection of cyclophosphamide (CP), or CP+HNG and killed at the end of 3 weeks. HNG rescued the CP-induced suppression of leucocytes and protected germ cell from CP-induced apoptosis. Lung metastases were suppressed by HNG or CP alone, and further suppressed by CP+HNG treatment. Plasma IGF-1 levels were suppressed by HNG with or without CP treatment. To investigate whether HNG maintains its protective effects on spermatogonial stem cells, sperm output, and peripheral leucocytes after repeated doses of CP, normal adult male mice received: no treatment, daily sc injection of HNG, 6 ip injections of CP at 5-day intervals, and the same regimens of CP+HNG and killed at the end of 4 weeks of treatment. Cauda epididymal sperm counts were elevated by HNG and suppressed by CP. HNG rescued the CP-induced suppression of spermatogonial stem cells, sperm count and peripheral leucocytes. We conclude that HNG 1) protects CP-induced loss of male germ cells and leucocytes, 2) enhances CP-induced suppression of cancer metastases, and 3) acts as a caloric-restriction mimetic by suppressing IGF-1 levels. Our findings suggest that humanin analogues may be promising adjuvants to chemotherapy.

  3. Mesenchymal stem cells-regulated Treg cells suppress colitis-associated colorectal cancer.

    Science.gov (United States)

    Tang, Rui-jing; Shen, Su-nan; Zhao, Xiao-yin; Nie, Yun-zhong; Xu, Yu-jun; Ren, Jing; Lv, Ming-ming; Hou, Ya-yi; Wang, Ting-ting

    2015-04-13

    Previous studies have produced controversial results regarding whether mesenchymal stem cells (MSCs) promote or inhibit tumor development. Given the dual role of MSCs in inflammation and cancer, in this study the colitis-associated colorectal cancer (CAC) model was used to examine whether umbilical cord tissue-derived MSCs could prevent neoplasm by inhibiting chronic inflammation. MSCs were obtained and identified using flow cytometry. Colitis-associated colorectal cancer model was induced using azoxymethane (AOM) and dextran sulfate sodium (DSS) and MSCs were injected intravenously twice. Levels of immune cells in mesenteric lymph node including regulatory T (Treg) cells were detected using flow cytometry. Naïve T cells and Jurkat cells were co-cultured with MSCs and the effect of MSCs on Treg cells differentiation was evaluated. After injection through tail vein, MSCs could migrate to colon and suppress colitis-related neoplasm. This tumor suppressive effect was characterized by longer colon length, decreased tumor numbers and decreased expression of Ki-67. Moreover, MSCs alleviated the pathology of inflammation in the colitis stage of CAC model and inhibited inflammation cytokines both in colon and serum. Furthermore, Treg cells were accumulated in mesenteric lymph node of MSCs-treated mice while the percentage of T helper cells 2 (Th2) and Th17 were not changed. Of note, MSCs secreted transforming growth factor-β (TGF-β) enhanced the induction of Treg cells from naïve T cells. The conditioned medium of MSCs also activated Smad2 signaling, which has been reported to regulate Treg cells. These results proved that MSCs could migrate to colon tissues and induce the differentiation of Treg cells via Smad2 as so to inhibit the colitis and suppress the development of CAC.

  4. Obesity suppresses circulating level and function of endothelial progenitor cells and heart function

    Directory of Open Access Journals (Sweden)

    Tsai Tzu-Hsien

    2012-07-01

    Full Text Available Abstract Background and aim This study tested the hypothesis that obesity suppresses circulating number as well as the function of endothelial progenitor cells (EPCs and left ventricular ejection fraction (LVEF. Methods High fat diet (45 Kcal% fat was given to 8-week-old C57BL/6 J mice (n = 8 for 20 weeks to induce obesity (group 1. Another age-matched group (n = 8 were fed with control diet for 20 weeks as controls (group 2. The animals were sacrificed at the end of 20 weeks after obesity induction. Results By the end of study period, the heart weight, body weight, abdominal fat weight, serum levels of total cholesterol and fasting blood sugar were remarkably higher in group 1 than in group 2 (all p Conclusions Obesity diminished circulating EPC level, impaired the recovery of damaged endothelium, suppressed EPC angiogenesis ability and LVEF, and increased LV remodeling.

  5. IgA-binding factor suppresses synthesis of IgA in MOPC-315 plasmacytoma cells

    International Nuclear Information System (INIS)

    Darby, C.; Moore, J.S.; Muller, S.; Aaronsen, D.; Madianos, E.; Hoover, R.G.

    1986-01-01

    T cells with Fc receptors for IgA (T/sup α/ cells) and their products, IgA-binding factors (IgABF), have been implicated in the regulation of IgA expression by B cells. They have previously shown that an IgABF produced by IgA induced normal T cells or constitutively by the Fc/sup α/ R+ T cell lymphoma, BALENTL 8, is capable of suppressing the proliferation and the amount of secreted IgA by MOPC-315 cells. In the present studies, they demonstrate that: (a) suppression of proliferation and secretion requires surface membrane IgA on the target cell, (b) suppression exhibits rapid kinetics with maximal effect occurring by 3-4 hours, (c) suppression is reversible, and (d) suppression of secretion involves selective suppression of IgA synthesis as measured by 3 H-leucine incorporation into immunoprecipitable IgA(non-IgA protein is unaffected). These findings indicate that IgA-isotype-specific effector molecules interact directly with their B cell targets through surface membrane immunoglobulin and cause a down regulation of immunoglobulin synthesis by the target. Current studies are underway to address whether this selective suppression of IgA is mediated at the transcriptional, translational or post-translational level. The use of MOPC-315 tumor cells as targets of T cell produced, isotype-specific, effector molecules should provide a unique model for the further analysis of isotype regulation at the molecular level

  6. Lipopolysaccharide suppresses IgE-mast cell-mediated reactions.

    Science.gov (United States)

    Wang, N; McKell, M; Dang, A; Yamani, A; Waggoner, L; Vanoni, S; Noah, T; Wu, D; Kordowski, A; Köhl, J; Hoebe, K; Divanovic, S; Hogan, S P

    2017-12-01

    Clinical and experimental analyses have identified a central role for IgE/FcεRI/mast cells in promoting IgE-mediated anaphylaxis. Recent data from human studies suggest that bacterial infections can alter susceptibility to anaphylaxis. We examined the effect of LPS exposure on the induction of IgE-mast cell (MC) mediated reactions in mice. C57BL/6 WT, tlr4 -/- and IL10 -/- mice were exposed to LPS, and serum cytokines (TNF and IL-10) were measured. Mice were subsequently treated with anti-IgE, and the symptoms of passive IgE-mediated anaphylaxis, MC activation, Ca 2+ -mobilization and the expression of FcεRI on peritoneal MCs were quantitated. We show that LPS exposure of C57BL/6 WT mice constraints IgE-MC-mediated reactions. LPS-induced suppression of IgE-MC-mediated responses was TLR-4-dependent and associated with increased systemic IL-10 levels, decreased surface expression of FcεRI on MCs and loss of sensitivity to IgE activation. Notably, LPS-induced desensitization of MCs was short term with MC sensitivity to IgE reconstituted within 48 hours, which was associated with recapitulation of FcεRI expression on the MCs. Mechanistic analyses revealed a requirement for IL-10 in LPS-mediated decrease in MC FcεRI surface expression. Collectively, these studies suggest that LPS-induced IL-10 promotes the down-regulation of MC surface FcεRI expression and leads to desensitization of mice to IgE-mediated reactions. These studies indicate that targeting of the LPS-TLR-4-IL-10 pathway may be used as a therapeutic approach to prevent adverse IgE-mediated reactions. © 2017 John Wiley & Sons Ltd.

  7. Dental pulp stem cells promote regeneration of damaged neuron cells on the cellular model of Alzheimer's disease.

    Science.gov (United States)

    Wang, Feixiang; Jia, Yali; Liu, Jiajing; Zhai, Jinglei; Cao, Ning; Yue, Wen; He, Huixia; Pei, Xuetao

    2017-06-01

    Alzheimer's disease (AD) is an incurable neurodegenerative disease and many types of stem cells have been used in AD therapy with some favorable effects. In this study, we investigated the potential therapeutical effects of human dental pulp stem cells (hDPSCs) on AD cellular model which established by okadaic acid (OA)-induced damage to human neuroblastoma cell line, SH-SY5Y, in vitro for 24 h. After confirmed the AD cellular model, the cells were co-culture with hDPSCs by transwell co-culture system till 24 h for treatment. Then the cytomorphology of the hDPSCs-treated cells were found to restore gradually with re-elongation of retracted dendrites. Meanwhile, Cell Counting Kit-8 assay and Hoechst 33258 staining showed that hDPSCs caused significant increase in the viability and decrease in apoptosis of the model cells, respectively. Observation of DiI labeling also exhibited the prolongation dendrites in hDPSCs-treated cells which were obviously different from the retraction dendrites in AD model cells. Furthermore, specific staining of α-tubulin and F-actin demonstrated that the hDPSCs-treated cells had the morphology of restored neurons, with elongated dendrites, densely arranged microfilaments, and thickened microtubular fibrils. In addition, results from western blotting revealed that phosphorylation at Ser 396 of Tau protein was significantly suppressed by adding of hDPSCs. These results indicate that hDPSCs may promote regeneration of damaged neuron cells in vitro model of AD and may serve as a useful cell source for treatment of AD. © 2017 International Federation for Cell Biology.

  8. Butyl benzyl phthalate suppresses the ATP-induced cell proliferation in human osteosarcoma HOS cells

    International Nuclear Information System (INIS)

    Liu, P.-S.; Chen, C.-Y.

    2010-01-01

    Butyl benzyl phthalate (BBP), an endocrine disruptor present in the environment, exerts its genomic effects via intracellular steroid receptors and elicits non-genomic effects by interfering with membrane ion-channel receptors. We previously found that BBP blocks the calcium signaling coupled with P2X receptors in PC12 cells (Liu and Chen, 2006). Osteoblast P2X receptors were recently reported to play a role in cell proliferation and bone remodeling. In this present study, the effects of BBP on ATP-induced responses were investigated in human osteosarcoma HOS cells. These receptors mRNA had been detected, named P2X4, P2X7, P2Y2, P2Y4, P2Y5, P2Y9, and P2Y11, in human osteosarcoma HOS cells by RT-PCR. The enhancement of cell proliferation and the decrease of cytoviability had both been shown to be coupled to stimulation via different concentrations of ATP. BBP suppressed the ATP-induced calcium influx (mainly coupled with P2X) and cell proliferation but not the ATP-induced intracellular calcium release (mainly coupled with P2Y) and cytotoxicity in human osteosarcoma HOS cells. Suramin, a common P2 receptor's antagonist, blocked the ATP-induced calcium signaling, cell proliferation, and cytotoxicity. We suggest that P2X is mainly responsible for cell proliferation, and P2Y might be partially responsible for the observed cytotoxicity. BBP suppressed the calcium signaling coupled with P2X, suppressing cell proliferation. Since the importance of P2X receptors during bone metastasis has recently become apparent, the possible toxic risk of environmental BBP during bone remodeling is a public problem of concern.

  9. Gigantol Suppresses Cancer Stem Cell-Like Phenotypes in Lung Cancer Cells

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    Narumol Bhummaphan

    2015-01-01

    Full Text Available As cancer stem cells (CSCs contribute to malignancy, metastasis, and relapse of cancers, potential of compound in inhibition of CSCs has garnered most attention in the cancer research as well as drug development fields recently. Herein, we have demonstrated for the first time that gigantol, a pure compound isolated from Dendrobium draconis, dramatically suppressed stem-like phenotypes of human lung cancer cells. Gigantol at nontoxic concentrations significantly reduced anchorage-independent growth and survival of the cancer cells. Importantly, gigantol significantly reduced the ability of the cancer cells to form tumor spheroids, a critical hallmark of CSCs. Concomitantly, the treatment of the compound was shown to reduce well-known lung CSCs markers, including CD133 and ALDH1A1. Moreover, we revealed that gigantol decreased stemness in the cancer cells by suppressing the activation of protein kinase B (Akt signal which in turn decreased the cellular levels of pluripotency and self-renewal factors Oct4 and Nanog. In conclusion, gigantol possesses CSCs suppressing activity which may facilitate the development of this compound for therapeutic approaches by targeting CSCs.

  10. Damage to human lung cells by inhalation noxes

    Energy Technology Data Exchange (ETDEWEB)

    Ebert, W.; Mayer, D.; Vogt-Moykopf, I.; Horsch, F.; Filby, W.G.; Fund, N.; Gross, S.; Hanisch, B.; Kilz, E.; Seidel, A. (comps.)

    1988-04-01

    Cell mortality of cultivated human pneumocytes (A-549) was determined via trypan blue dying of damaged cells after application of toxic gases (ozone or nitrogen dioxide) to the cultures. Cytotoxicity could be reproducibly decreased by the addition of the following antioxidative compounds to culture media (HAM's F 12 K-medium): D,L-alpha-tocopherol (10 ..mu..g/ml), histidine (2 mM) and superoxide dismutase (100 units/ml). Whereas only tocopherol had a cytoprotective effect in regard to ozone immissions, reducing cell mortality by 12%, superoxide dismutase and histidine diminished mortality during NO/sub 2/-application (by 55% and 6%, respectively).

  11. Lgr4 Expression in Osteoblastic Cells Is Suppressed by Hydrogen Peroxide Treatment.

    Science.gov (United States)

    Pawaputanon Na Mahasarakham, Chantida; Izu, Yayoi; Nishimori, Katsuhiko; Izumi, Yuichi; Noda, Masaki; Ezura, Yoichi

    2017-07-01

    LGR4 is expressed in bone and has been shown to be involved in bone metabolism. Oxidative stress is one of the key issues in pathophysiology of osteoporosis. However, the link between Lgr4 and oxidative stress has not been known. Therefore, effects of hydrogen peroxide on Lgr4 expression in osteoblasts were examined. Hydrogen peroxide treatment suppressed the levels of Lgr4 mRNA expression in an osteoblastic cell line, MC3T3-E1. The suppressive effects were not obvious at 0.1 mM, while 1 mM hydrogen peroxide suppressed Lgr4 expression by more than 50%. Hydrogen peroxide treatment suppressed Lgr4 expression within 12 h and this suppression lasted at least up to 48 h. Hydrogen peroxide suppression of Lgr4 expression was still observed in the presence of a transcription inhibitor but was no longer observed in the presence of a protein synthesis inhibitor. Although Lgr4 expression in osteoblasts is enhanced by BMP2 treatment as reported before, hydrogen peroxide treatment suppressed Lgr4 even in the presence of BMP2. Finally, hydrogen peroxide suppressed Lgr4 expression in primary cultures of osteoblasts similarly to MC3T3-E1 cells. These date indicate that hydrogen peroxide suppresses Lgr4 expression in osteoblastic cells. J. Cell. Physiol. 232: 1761-1766, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  12. CTLA-4 (CD152) controls homeostasis and suppressive capacity of regulatory T cells in mice.

    Science.gov (United States)

    Kolar, Paula; Knieke, Karin; Hegel, J Kolja E; Quandt, Dagmar; Burmester, Gerd-R; Hoff, Holger; Brunner-Weinzierl, Monika C

    2009-01-01

    CD4+CD25+ regulatory T cells (known as Treg cells) suppress unwanted and autoreactive T cell responses. Treg cells express the costimulatory molecule CTLA-4 intracellularly, but the mechanisms by which Treg cells exploit CTLA-4 signaling remain unclear. The present study was undertaken to investigate the role of CTLA-4 in controlling the homeostasis and suppressive function of Treg cells. Murine Treg cells were analyzed by flow cytometry for coexpression of CTLA-4 and typical Treg cell-expressed molecules, and the influence of CTLA-4 on T cell proliferation, suppression, and apoptosis was investigated by in vitro assays. To analyze the importance of CTLA-4 in Treg cell-mediated suppression in vivo, wild-type Treg cells were transferred into CTLA-4-deficient mice displaying lymphoproliferation, and survival was monitored over time. A strong correlation between expression of forkhead box P3 and ex vivo expression of CTLA-4 in Treg cells was observed. Inhibition of CTLA-4 signaling in Treg cells during in vitro stimulation increased cell cycling and led to enhanced activation-induced cell death (AICD), which was mediated by CD95/CD95 ligand-induced activation of caspases. Blockade of CTLA-4 signaling resulted in impairment of the suppressive capacity of Treg cells. Despite these effects, high amounts of Treg cells persisted in CTLA-4-deficient mice. Results of transfer experiments in CTLA-4-deficient mice showed that the mice had a significantly prolonged lifespan when CTLA-4-competent Treg cells were injected. Expression of CTLA-4 on Treg cells serves to control T cell proliferation, to confer resistance against AICD, and to maintain the suppressive function of Treg cells.

  13. Damage-induced DNA repair processes in Escherichia coli cells

    International Nuclear Information System (INIS)

    Slezarikova, V.

    1986-01-01

    The existing knowledge is summed up of the response of Escherichia coli cells to DNA damage due to various factors including ultraviolet radiation. So far, three inducible mechanisms caused by DNA damage are known, viz., SOS induction, adaptation and thermal shock induction. Greatest attention is devoted to SOS induction. Its mechanism is described and the importance of the lexA recA proteins is shown. In addition, direct or indirect role is played by other proteins, such as the ssb protein binding the single-strand DNA sections. The results are reported of a study of induced repair processes in Escherichia coli cells repeatedly irradiated with UV radiation. A model of induction by repeated cell irradiation discovered a new role of induced proteins, i.e., the elimination of alkali-labile points in the daughter DNA synthetized on a damaged model. The nature of the alkali-labile points has so far been unclear. In the adaptation process, regulation proteins are synthetized whose production is induced by the presence of alkylation agents. In the thermal shock induction, new proteins synthetize in cells, whose function has not yet been clarified. (E.S.)

  14. Suppression of Th1-mediated autoimmunity by embryonic stem cell-derived dendritic cells.

    Directory of Open Access Journals (Sweden)

    Tokunori Ikeda

    Full Text Available We herein demonstrate the immune-regulatory effect of embryonic stem cell-derived dendritic cells (ES-DCs using two models of autoimmune disease, namely non-obese diabetic (NOD mice and experimental autoimmune encephalomyelitis (EAE. Treatment of pre-diabetic NOD mice with ES-DCs exerted almost complete suppression of diabetes development during the observation period for more than 40 weeks. The prevention of diabetes by ES-DCs was accompanied with significant reduction of insulitis and decreased number of Th1 and Th17 cells in the spleen. Development of EAE was also inhibited by the treatment with ES-DCs, and the therapeutic effect was obtained even if ES-DCs were administrated after the onset of clinical symptoms. Treatment of EAE-induced mice with ES-DCs reduced the infiltration of inflammatory cells into the spinal cord and suppressed the T cell response to the myelin antigen. Importantly, the ES-DC treatment did not affect T cell response to an exogenous antigen. As the mechanisms underlying the reduction of the number of infiltrating Th1 cells, we observed the inhibition of differentiation and proliferation of Th1 cells by ES-DCs. Furthermore, the expression of VLA-4α on Th1 cells was significantly inhibited by ES-DCs. Considering the recent advances in human induced pluripotent stem cell-related technologies, these results suggest a clinical application for pluripotent stem cell-derived dendritic cells as a therapy for T cell-mediated autoimmune diseases.

  15. Astrocytic gap junctional networks suppress cellular damage in an in vitro model of ischemia

    International Nuclear Information System (INIS)

    Shinotsuka, Takanori; Yasui, Masato; Nuriya, Mutsuo

    2014-01-01

    Highlights: • Astrocytes exhibit characteristic changes in [Ca 2+ ] i under OGD. • Astrocytic [Ca 2+ ] i increase is synchronized with a neuronal anoxic depolarization. • Gap junctional couplings protect neurons as well as astrocytes during OGD. - Abstract: Astrocytes play pivotal roles in both the physiology and the pathophysiology of the brain. They communicate with each other via extracellular messengers as well as through gap junctions, which may exacerbate or protect against pathological processes in the brain. However, their roles during the acute phase of ischemia and the underlying cellular mechanisms remain largely unknown. To address this issue, we imaged changes in the intracellular calcium concentration ([Ca 2+ ] i ) in astrocytes in mouse cortical slices under oxygen/glucose deprivation (OGD) condition using two-photon microscopy. Under OGD, astrocytes showed [Ca 2+ ] i oscillations followed by larger and sustained [Ca 2+ ] i increases. While the pharmacological blockades of astrocytic receptors for glutamate and ATP had no effect, the inhibitions of gap junctional intercellular coupling between astrocytes significantly advanced the onset of the sustained [Ca 2+ ] i increase after OGD exposure. Interestingly, the simultaneous recording of the neuronal membrane potential revealed that the onset of the sustained [Ca 2+ ] i increase in astrocytes was synchronized with the appearance of neuronal anoxic depolarization. Furthermore, the blockade of gap junctional coupling resulted in a concurrent faster appearance of neuronal depolarizations, which remain synchronized with the sustained [Ca 2+ ] i increase in astrocytes. These results indicate that astrocytes delay the appearance of the pathological responses of astrocytes and neurons through their gap junction-mediated intercellular network under OGD. Thus, astrocytic gap junctional networks provide protection against tissue damage during the acute phase of ischemia

  16. In vivo suppression of HIV by antigen specific T cells derived from engineered hematopoietic stem cells.

    Directory of Open Access Journals (Sweden)

    Scott G Kitchen

    Full Text Available The HIV-specific cytotoxic T lymphocyte (CTL response is a critical component in controlling viral replication in vivo, but ultimately fails in its ability to eradicate the virus. Our intent in these studies is to develop ways to enhance and restore the HIV-specific CTL response to allow long-term viral suppression or viral clearance. In our approach, we sought to genetically manipulate human hematopoietic stem cells (HSCs such that they differentiate into mature CTL that will kill HIV infected cells. To perform this, we molecularly cloned an HIV-specific T cell receptor (TCR from CD8+ T cells that specifically targets an epitope of the HIV-1 Gag protein. This TCR was then used to genetically transduce HSCs. These HSCs were then introduced into a humanized mouse containing human fetal liver, fetal thymus, and hematopoietic progenitor cells, and were allowed to differentiate into mature human CD8+ CTL. We found human, HIV-specific CTL in multiple tissues in the mouse. Thus, genetic modification of human HSCs with a cloned TCR allows proper differentiation of the cells to occur in vivo, and these cells migrate to multiple anatomic sites, mimicking what is seen in humans. To determine if the presence of the transgenic, HIV-specific TCR has an effect on suppressing HIV replication, we infected with HIV-1 mice expressing the transgenic HIV-specific TCR and, separately, mice expressing a non-specific control TCR. We observed significant suppression of HIV replication in multiple organs in the mice expressing the HIV-specific TCR as compared to control, indicating that the presence of genetically modified HIV-specific CTL can form a functional antiviral response in vivo. These results strongly suggest that stem cell based gene therapy may be a feasible approach in the treatment of chronic viral infections and provide a foundation towards the development of this type of strategy.

  17. High glucose suppresses embryonic stem cell differentiation into cardiomyocytes : High glucose inhibits ES cell cardiogenesis.

    Science.gov (United States)

    Yang, Penghua; Chen, Xi; Kaushal, Sunjay; Reece, E Albert; Yang, Peixin

    2016-12-09

    Babies born to mothers with pregestational diabetes have a high risk for congenital heart defects (CHD). Embryonic stem cells (ESCs) are excellent in vitro models for studying the effect of high glucose on cardiac lineage specification because ESCs can be differentiated into cardiomyocytes. ESC maintenance and differentiation are currently performed under high glucose conditions, whose adverse effects have never been clarified. We investigated the effect of high glucose on cardiomyocyte differentiation from a well-characterized ESC line, E14, derived from mouse blastocysts. E14 cells maintained under high glucose (25 mM) failed to generate any beating cardiomyocytes using the hanging-drop embryonic body method. We created a glucose-responsive E14 cell line (GR-E14) through a graduated low glucose adaptation. The expression of stem cell markers was similar in the parent E14 cells and the GR-E14 cells. Glucose transporter 2 gene was increased in GR-E14 cells. When GR-E14 cells were differentiated into cardiomyocytes under low (5 mM) or high (25 mM) glucose conditions, high glucose significantly delayed the appearance and reduced the number of TNNT2 (Troponin T Type 2)-positive contracting cardiomyocytes. High glucose suppressed the expression of precardiac mesoderm markers, cardiac transcription factors, mature cardiomyocyte markers, and potassium channel proteins. High glucose impaired the functionality of ESC-derived cardiomyocytes by suppressing the frequencies of Ca 2+ wave and contraction. Our findings suggest that high glucose inhibits ESC cardiogenesis by suppressing key developmental genes essential for the cardiac program.

  18. Protective Effects of Resveratrol against UVA-Induced Damage in ARPE19 Cells

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    Chi-Ming Chan

    2015-03-01

    Full Text Available Ultraviolet radiation, especially UVA, can penetrate the lens, reach the retina, and induce oxidative stress to retinal pigment epithelial (RPE cells. Even though it is weakly absorbed by protein and DNA, it may trigger the production of reactive oxygen species (ROS and generate oxidative injury; oxidative injury to the retinal pigment epithelium has been implicated to play a contributory role in age-related macular degeneration (AMD. Studies showed that resveratrol, an abundant and active component of red grapes, can protect several cell types from oxidative stress. In this study, adult RPE cells being treated with different concentrations of resveratrol were used to evaluate the protective effect of resveratrol on RPE cells against UVA-induced damage. Cell viability assay showed that resveratrol reduced the UVA-induced decrease in RPE cell viability. Through flow cytometry analysis, we found that the generation of intracellular H2O2 induced by UVA irradiation in RPE cells could be suppressed by resveratrol in a concentration-dependent manner. Results of Western blot analysis demonstrated that resveratrol lowered the activation of UVA-induced extracellular signal-regulated kinase, c-jun-NH2 terminal kinase and p38 kinase in RPE cells. In addition, there was also a reduction in UVA-induced cyclooxygenase-2 (COX-2 expression in RPE cells pretreated with resveratrol. Our observations suggest that resveratrol is effective in preventing RPE cells from being damaged by UVA radiation, and is worth considering for further development as a chemoprotective agent for the prevention of early AMD.

  19. Suppression of leukocyte inhibitory factor (LIF) production and [3H]thymidine incorporation by concanavalin A-activated mononuclear cells

    International Nuclear Information System (INIS)

    Lomnitzer, R.; Rabson, A.R.

    1979-01-01

    The capacity of human mononuclear (MN) cells pretreated with concanavalin A (Con A) to suppress the activity of fresh phytohemagglutinin (PHA)-pulsed mononuclear cells was assessed. Con A-pretreated MN cells suppressed leukocyte inhibitory factor (LIF) activity in supernatants of PHA-pulsed cell cultures and [ 3 H]thymidine incorporation by these cells. Suppression was obtained in both allogeneic and autologous systems with mitomycin-treated, irradiated, or untreated Con A-induced cells. Lymphocytes from two patients that, following treatment with Con A, did not suppress mitogen-induced proliferative response of normal cells also did not suppress LIF production

  20. Melanin photosensitizes ultraviolet light (UVC) DNA damage in pigmented cells

    International Nuclear Information System (INIS)

    Huselton, C.A.; Hill, H.Z.

    1990-01-01

    Melanins, pigments of photoprotection and camouflage, are very photoreactive and can both absorb and emit active oxygen species. Nevertheless, black skinned individuals rarely develop skin cancer and melanin is assumed to act as a solar screen. Since DNA is the target for solar carcinogenesis, the effect of melanin on Ultraviolet (UV)-induced thymine lesions was examined in mouse melanoma and carcinoma cells that varied in melanin content. Cells prelabeled with 14C-dThd were irradiated with UVC; DNA was isolated, purified, degraded to bases by acid hydrolysis and analyzed by HPLC. Thymine dimers were detected in all of the extracts of irradiated cells. Melanotic and hypomelanotic but not mammary carcinoma cell DNA from irradiated cells contained hydrophilic thymine derivatives. The quantity of these damaged bases was a function of both the UVC dose and the cellular melanin content. One such derivative was identified by gas chromatography-mass spectroscopy as thymine glycol. The other appears to be derived from thymine glycol by further oxidation during acid hydrolysis of the DNA. The finding of oxidative DNA damage in melanin-containing cells suggests that melanin may be implicated in the etiology of caucasian skin cancer, particularly melanoma. Furthermore, the projected decrease in stratospheric ozone could impact in an unanticipated deleterious manner on dark-skinned individuals

  1. DNA Damage by Radiation in Tradescantia Leaf Cells

    Energy Technology Data Exchange (ETDEWEB)

    Han, Min; Hyun, Kyung Man; Ryu, Tae Ho; Kim, Jin Kyu [Korea Atomic Energy Research Institute, Advanced Radiation Technology Institute, Jeongeup (Korea, Republic of); Nili, Mohammad [Dawnesh Radiation Research Institute, Barcelona (Spain)

    2010-04-15

    The comet assay is currently used in different areas of biological sciences to detect DNA damage. The comet assay, due to its simplicity, sensitivity and need of a few cells, is ideal as a short-term genotoxicity test. The comet assay can theoretically be applied to every type of eukaryotic cell, including plant cells. Plants are very useful as monitors of genetic effects caused by pollution in the atmosphere, water and soil. Tradescantia tests are very useful tools for screening the mutagenic potential in the environment. Experiments were conducted to study the genotoxic effects of ionizing radiations on the genome integrity, particularly of Tradescantia. The increasingly frequent use of Tradescantia as a sensitive environmental bioindicator of genotoxic effects. This study was designed to assess the genotoxicity of ionizing radiation using Tradescnatia-comet assay. The development of comet assay has enabled investigators to detect DNA damage at the levels of cells. To adapt this assay to plant cells, nuclei were directly obtained from Tradescantia leaf samples. A significant dose-dependent increase in the average tail moment values over the negative control was observed. Recently the adaptation of this technique to plant cells opens new possibilities for studies in variety area. The future applications of the comet assay could impact some other important areas, certainly, one of the limiting factors to its utility is the imagination of the investigator.

  2. Melanin photosensitizes ultraviolet light (UVC) DNA damage in pigmented cells

    Energy Technology Data Exchange (ETDEWEB)

    Huselton, C.A.; Hill, H.Z. (New Jersey Medical School, Newark (USA))

    1990-01-01

    Melanins, pigments of photoprotection and camouflage, are very photoreactive and can both absorb and emit active oxygen species. Nevertheless, black skinned individuals rarely develop skin cancer and melanin is assumed to act as a solar screen. Since DNA is the target for solar carcinogenesis, the effect of melanin on Ultraviolet (UV)-induced thymine lesions was examined in mouse melanoma and carcinoma cells that varied in melanin content. Cells prelabeled with 14C-dThd were irradiated with UVC; DNA was isolated, purified, degraded to bases by acid hydrolysis and analyzed by HPLC. Thymine dimers were detected in all of the extracts of irradiated cells. Melanotic and hypomelanotic but not mammary carcinoma cell DNA from irradiated cells contained hydrophilic thymine derivatives. The quantity of these damaged bases was a function of both the UVC dose and the cellular melanin content. One such derivative was identified by gas chromatography-mass spectroscopy as thymine glycol. The other appears to be derived from thymine glycol by further oxidation during acid hydrolysis of the DNA. The finding of oxidative DNA damage in melanin-containing cells suggests that melanin may be implicated in the etiology of caucasian skin cancer, particularly melanoma. Furthermore, the projected decrease in stratospheric ozone could impact in an unanticipated deleterious manner on dark-skinned individuals.

  3. Overexpression of human selenoprotein H in neuronal cells ameliorates ultraviolet irradiation-induced damage by modulating cell signaling pathways.

    Science.gov (United States)

    Mendelev, Natalia; Witherspoon, Sam; Li, P Andy

    2009-12-01

    Selenoprotein H (SelH) is one of the 25 so far identified selenoproteins. Selenoproteins may function as antioxidants, heavy metal antidotes, and neural survival factors. Previous studies have shown that overexpression of SelH in HT22 cells protected the cells from UVB irradiation-induced death by reducing superoxide formation. The objective of this study was to determine the effects of SelH on cell signaling pathways after UVB irradiation. We exposed both human SelH- and vector-transfected HT22 cells to UVB irradiation and collected samples at 5 and 17 h of recovery. Cell viability was assessed, as well as protein levels of caspase-3, -8, -9, apoptosis-inducing factor (AIF), P53, nuclear respiratory factor-1 (NRF-1) and heat shock protein 40 (HSP40). Mitochondrial membrane potential was determined by flow cytometry. Overexpression of SelH protected cells against UVB-induced injury by blockade of the mitochondria-initiated cell death pathway, prevention of mitochondrial membrane depolarization, and suppression of the increase of p53. Furthermore, overexpression of SelH increased levels of NRF-1, an antioxidant, and HSP40, a protein chaperone that repairs denatured protein. We conclude that SelH protects neurons against UVB-induced damage by inhibiting apoptotic cell death pathways, by preventing mitochondrial depolarization, and by promoting cell survival pathways.

  4. Hypoxia-ischemia and retinal ganglion cell damage

    Directory of Open Access Journals (Sweden)

    Charanjit Kaur

    2008-08-01

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

  5. 17-AAG enhances the cytotoxicity of flavopiridol in mantle cell lymphoma via autophagy suppression.

    Science.gov (United States)

    Xiao, Y; Guan, J

    2015-01-01

    Flavopiridol, a cyclin-dependent kinase inhibitor (CDKI), shows promising anti-tumor activity in hematologic malignancies. However, Flavopiridol-induced protective autophagy may lead to drug resistance. Here we found that Hsp90 inhibitor 17-AAG can sensitize mantle cell lymphoma (MCL) cells to flavopiridol by suppressing flavopiridol-triggered protective autophagy. The suppressing effect of 17-AAG on autophgy was mediated by Beclin1 degradation and ERK inactivation. Furthermore, 17-AAG enhanced flavopiridol-induced apoptosis and growth suppression in MCL cells. Our study may provide some insights into CDKI -targeted chemotherapies.

  6. Local stem cell depletion model for normal tissue damage

    International Nuclear Information System (INIS)

    Yaes, R.J.; Keland, A.

    1987-01-01

    The hypothesis that radiation causes normal tissue damage by completely depleting local regions of tissue of viable stem cells leads to a simple mathematical model for such damage. In organs like skin and spinal cord where destruction of a small volume of tissue leads to a clinically apparent complication, the complication probability is expressed as a function of dose, volume and stem cell number by a simple triple negative exponential function analogous to the double exponential function of Munro and Gilbert for tumor control. The steep dose response curves for radiation myelitis that are obtained with our model are compared with the experimental data for radiation myelitis in laboratory rats. The model can be generalized to include other types or organs, high LET radiation, fractionated courses of radiation, and cases where an organ with a heterogeneous stem cell population receives an inhomogeneous dose of radiation. In principle it would thus be possible to determine the probability of tumor control and of damage to any organ within the radiation field if the dose distribution in three dimensional space within a patient is known

  7. Roles for miR-375 in Neuroendocrine Differentiation and Tumor Suppression via Notch Pathway Suppression in Merkel Cell Carcinoma.

    Science.gov (United States)

    Abraham, Karan J; Zhang, Xiao; Vidal, Ricardo; Paré, Geneviève C; Feilotter, Harriet E; Tron, Victor A

    2016-04-01

    Dysfunction of key miRNA pathways regulating basic cellular processes is a common driver of many cancers. However, the biological roles and/or clinical applications of such pathways in Merkel cell carcinoma (MCC), a rare but lethal cutaneous neuroendocrine (NE) malignancy, have yet to be determined. Previous work has established that miR-375 is highly expressed in MCC tumors, but its biological role in MCC remains unknown. Herein, we show that elevated miR-375 expression is a specific feature of well-differentiated MCC cell lines that express NE markers. In contrast, miR-375 is strikingly down-regulated in highly aggressive, undifferentiated MCC cell lines. Enforced miR-375 expression in these cells induced NE differentiation, and opposed cancer cell viability, migration, invasion, and survival, pointing to tumor-suppressive roles for miR-375. Mechanistically, miR-375-driven phenotypes were caused by the direct post-transcriptional repression of multiple Notch pathway proteins (Notch2 and RBPJ) linked to cancer and regulation of cell fate. Thus, we detail a novel molecular axis linking tumor-suppressive miR-375 and Notch with NE differentiation and cancer cell behavior in MCC. Our findings identify miR-375 as a putative regulator of NE differentiation, provide insight into the cell of origin of MCC, and suggest that miR-375 silencing may promote aggressive cancer cell behavior through Notch disinhibition. Copyright © 2016 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  8. DNA damage in Human Limbal Epithelial Cells expanded ex vivo.

    Directory of Open Access Journals (Sweden)

    Yolanda Lorenzo Corrales

    2015-04-01

    Full Text Available Limbal stem cell deficiency, secondary to insults and diseases, may be treated by transplantation of ex vivo engineered epithelial grafts. We here present preliminary data on levels of cellular DNA damage in grafts produced in two different types of culture medium. Cultures were initiated using corneo-limbal donor tissue after removal of the central area for transplant purposes. Explants (approx. 2x2 mm were positioned epithelial side down on tissue culture treated polyester membranes and expanded for four weeks in Dulbecco’s Modified Eagle Medium F12 Nutrient Mixture (Ham [DMEM/F12 (1:1] with either (1 H. medium; 10% human serum or (2 COM; 5% fetal bovine serum (FBS, Epidermal Growth Factor (EGF, insulin-transferrin-sodiumselenzine (ITS , cholera toxin-A, dimethyl sulfoxide (DMSO and hydrocortisone. Cells were dissociated using Trypsin-EDTA (0.05% for 30 min., the enzyme activity was inhibited by medium and serum. The cell suspension was transferred to tubes on ice and processed using the Comet Assay. Duplicate samples from each culture were analyzed in each assay by visual scoring. Using a fluorescence microscope, 100 comets (50 from each gel were classified into five categories, 0-4, representing increasing relative tail intensities. Summing the scores (0-4 of 100 comets therefore gives an overall score of between 0 and 400 arbitrary units. Preliminary data show some levels of DNA damage in cells dissociated from the grafts regardless of the type of culture medium used. Anyway more experiments with other donors have to be done to have some conclusions. Recent studies have shown that medium with human serum equally support production of grafts containing differentiated as well as undifferentiated cells suitable for clinical transplantation. Preliminary data from our experiments indicate that levels of molecular damage to the DNA do not increase in cells cultured in H. medium despite its lacks of complexity.

  9. The Fanconi anemia pathway: Repairing the link between DNA damage and squamous cell carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Romick-Rosendale, Lindsey E. [Division of Oncology, Cancer and Blood Diseases Institute, Cincinnati Children' s Hospital Medical Center, Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229 (United States); Lui, Vivian W.Y.; Grandis, Jennifer R. [Department of Otolaryngology, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, PA 15213 (United States); Wells, Susanne I., E-mail: Susanne.Wells@cchmc.org [Division of Oncology, Cancer and Blood Diseases Institute, Cincinnati Children' s Hospital Medical Center, Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229 (United States)

    2013-03-15

    Fanconi anemia (FA) is a rare inherited recessive disease caused by mutations in one of fifteen genes known to encode FA pathway components. In response to DNA damage, nuclear FA proteins associate into high molecular weight complexes through a cascade of post-translational modifications and physical interactions, followed by the repair of damaged DNA. Hematopoietic cells are particularly sensitive to the loss of these interactions, and bone marrow failure occurs almost universally in FA patients. FA as a disease is further characterized by cancer susceptibility, which highlights the importance of the FA pathway in tumor suppression, and will be the focus of this review. Acute myeloid leukemia is the most common cancer type, often subsequent to bone marrow failure. However, FA patients are also at an extreme risk of squamous cell carcinoma (SCC) of the head and neck and gynecological tract, with an even greater incidence in those individuals who have received a bone marrow transplant and recovered from hematopoietic disease. FA tumor suppression in hematopoietic versus epithelial compartments could be mechanistically similar or distinct. Definition of compartment specific FA activities is now critical to assess the effects of today's bone marrow failure treatments on tomorrow's solid tumor development. It is our hope that current therapies can then be optimized to decrease the risk of malignant transformation in both hematopoietic and epithelial cells. Here we review our current understanding of the mechanisms of action of the Fanconi anemia pathway as it contributes to stress responses, DNA repair and squamous cell carcinoma susceptibility.

  10. A novel Meloidogyne enterolobii effector MeTCTP promotes parasitism by suppressing programmed cell death in host plants.

    Science.gov (United States)

    Zhuo, Kan; Chen, Jiansong; Lin, Borong; Wang, Jing; Sun, Fengxia; Hu, Lili; Liao, Jinling

    2017-01-01

    Meloidogyne enterolobii is one of the most important plant-parasitic nematodes that can overcome the Mi-1 resistance gene and damage many economically important crops. Translationally controlled tumour protein (TCTP) is a multifunctional protein that exists in various eukaryotes and plays an important role in parasitism. In this study, a novel M. enterolobii TCTP effector, named MeTCTP, was identified and functionally characterized. MeTCTP was specifically expressed within the dorsal gland and was up-regulated during M. enterolobii parasitism. Transient expression of MeTCTP in protoplasts from tomato roots showed that MeTCTP was localized in the cytoplasm of the host cells. Transgenic Arabidopsis thaliana plants overexpressing MeTCTP were more susceptible to M. enterolobii infection than wild-type plants in a dose-dependent manner. By contrast, in planta RNA interference (RNAi) targeting MeTCTP suppressed the expression of MeTCTP in infecting nematodes and attenuated their parasitism. Furthermore, MeTCTP could suppress programmed cell death triggered by the pro-apoptotic protein BAX. These results demonstrate that MeTCTP is a novel plant-parasitic nematode effector that promotes parasitism, probably by suppressing programmed cell death in host plants. © 2016 BSPP and John Wiley & Sons Ltd.

  11. Silencing of semaphorin 3C suppresses cell proliferation and migration in MCF-7 breast cancer cells.

    Science.gov (United States)

    Zhu, Xiaofang; Zhang, Xiangjian; Ye, Zhiqiang; Chen, Yizuo; Lv, Lin; Zhang, Xiaohua; Hu, Hongye

    2017-11-01

    Previous studies have suggested that semaphorin 3C (SEMA3C) is involved in the tumorigenesis and metastasis of a number of types of cancer. The aim of the present study was to investigate the role of SEMA3C in the proliferation and migration of MCF-7 breast cancer cells. Small interfering (si)RNA sequences targeting SEMA3C were constructed and transfected into MCF-7 cells in order to silence the expression of SEMA3C. Cell proliferation and migration were measured using CCK-8 and Transwell assays, respectively. Transfection with SEMA3C siRNA significantly downregulated the expression of SEMA3C in MCF-7 cells, and significantly suppressed cell proliferation and migration. Therefore, SEMA3C-targeted siRNA may be of potential use for the early diagnosis and treatment of breast cancer.

  12. Mycoplasma suppression of THP-1 Cell TLR responses is corrected with antibiotics.

    Science.gov (United States)

    Zakharova, Ekaterina; Grandhi, Jaykumar; Wewers, Mark D; Gavrilin, Mikhail A

    2010-03-25

    Mycoplasma contamination of cultured cell lines is a serious problem in research, altering cellular response to different stimuli thus compromising experimental results. We found that chronic mycoplasma contamination of THP-1 cells suppresses responses of THP-1 cells to TLR stimuli. For example, E. coli LPS induced IL-1 beta was suppressed by 6 fold and IL-8 by 10 fold in mycoplasma positive THP-1 cells. Responses to live F. novicida challenge were suppressed by 50-fold and 40-fold respectively for IL-1beta and IL-8. Basal TLR4 expression level in THP-1 cells was decreased by mycoplasma by 2.4-fold (p = 0.0003). Importantly, cell responses to pathogen associated molecular patterns are completely restored by mycoplasma clearance with Plasmocin. Thus, routine screening of cell lines for mycoplasma is important for the maintenance of reliable experimental data and contaminated cell lines can be restored to their baseline function with antibiotic clearance of mycoplasma.

  13. Mycoplasma suppression of THP-1 Cell TLR responses is corrected with antibiotics.

    Directory of Open Access Journals (Sweden)

    Ekaterina Zakharova

    2010-03-01

    Full Text Available Mycoplasma contamination of cultured cell lines is a serious problem in research, altering cellular response to different stimuli thus compromising experimental results. We found that chronic mycoplasma contamination of THP-1 cells suppresses responses of THP-1 cells to TLR stimuli. For example, E. coli LPS induced IL-1 beta was suppressed by 6 fold and IL-8 by 10 fold in mycoplasma positive THP-1 cells. Responses to live F. novicida challenge were suppressed by 50-fold and 40-fold respectively for IL-1beta and IL-8. Basal TLR4 expression level in THP-1 cells was decreased by mycoplasma by 2.4-fold (p = 0.0003. Importantly, cell responses to pathogen associated molecular patterns are completely restored by mycoplasma clearance with Plasmocin. Thus, routine screening of cell lines for mycoplasma is important for the maintenance of reliable experimental data and contaminated cell lines can be restored to their baseline function with antibiotic clearance of mycoplasma.

  14. DNA damage response (DDR) via NKX3.1 expression in prostate cells.

    Science.gov (United States)

    Erbaykent-Tepedelen, Burcu; Karamil, Selda; Gonen-Korkmaz, Ceren; Korkmaz, Kemal S

    2014-05-01

    It has been reported that NKX3.1 an androgen-regulated homeobox gene restricted to prostate and testicular tissues, encodes a homeobox protein, which transcriptionally regulates oxidative damage responses and enhances topoisomerase I re-ligation by a direct interaction with the ATM protein in prostate cells. In this study, we aimed to investigate the role of NKX3.1 in DNA double-strand break (DSB) repair. We demonstrate that the DNA damage induced by CPT-11 (irinotecan, a topo I inhibitor), doxorubicin (a topo II inhibitor), and H2O2 (a mediator of oxidative damage), but not by etoposide (another topo II inhibitor), is negatively influenced by NKX3.1 expression. We also examined γH2AX((S139)) foci formation and observed that the overexpression of NKX3.1 resulted a remarkable decrease in the formation of γH2AX((S139)) foci. Intriguingly, we observed in NKX3.1 silencing studies that the depletion of NKX3.1 correlated with a significant decrease in the levels of p-ATM((S1981)) and γH2AX((S139)). The data imply that the DNA damage response (DDR) can be altered, perhaps via a decrease in the topoisomerase I re-ligation function; this is consistent with the physical association of NKX3.1 with DDR mediators upon treatment of both PC-3 and LNCaP cells with CPT-11. Furthermore, the depletion of NKX3.1 resulted in a G1/S progression via the facilitation of an increase in E2F stabilization concurrent with the suppressed DDR. Thus, the topoisomerase I inhibitor-mediated DNA damage enhanced the physical association of NKX3.1 with γH2AX((S139)) on the chromatin in LNCaP cells, whereas NKX3.1 in the soluble fraction was associated with p-ATM((S1981)) and RAD50 in these cells. Overall, the data suggest that androgens and NKX3.1 expression regulate the progression of the cell cycle and concurrently activate the DDR. Therefore, androgen withdrawal may augment the development of an error-prone phenotype and, subsequently, the loss of DNA damage control during prostate cancer

  15. Polyphosphate is a key factor for cell survival after DNA damage in eukaryotic cells.

    Science.gov (United States)

    Bru, Samuel; Samper-Martín, Bàrbara; Quandt, Eva; Hernández-Ortega, Sara; Martínez-Laínez, Joan M; Garí, Eloi; Rafel, Marta; Torres-Torronteras, Javier; Martí, Ramón; Ribeiro, Mariana P C; Jiménez, Javier; Clotet, Josep

    2017-09-01

    Cells require extra amounts of dNTPs to repair DNA after damage. Polyphosphate (polyP) is an evolutionary conserved linear polymer of up to several hundred inorganic phosphate (Pi) residues that is involved in many functions, including Pi storage. In the present article, we report on findings demonstrating that polyP functions as a source of Pi when required to sustain the dNTP increment essential for DNA repair after damage. We show that mutant yeast cells without polyP produce less dNTPs upon DNA damage and that their survival is compromised. In contrast, when polyP levels are ectopically increased, yeast cells become more resistant to DNA damage. More importantly, we show that when polyP is reduced in HEK293 mammalian cell line cells and in human dermal primary fibroblasts (HDFa), these cells become more sensitive to DNA damage, suggesting that the protective role of polyP against DNA damage is evolutionary conserved. In conclusion, we present polyP as a molecule involved in resistance to DNA damage and suggest that polyP may be a putative target for new approaches in cancer treatment or prevention. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Suppression of Natural Killer Cell Activity by Regulatory NKT10 Cells Aggravates Alcoholic Hepatosteatosis

    Directory of Open Access Journals (Sweden)

    Kele Cui

    2017-10-01

    Full Text Available We and others have found that the functions of hepatic natural killer (NK cells are inhibited but invariant NKT (iNKT cells become activated after alcohol drinking, leaving a possibility that there exists interplay between NK cells and iNKT cells during alcoholic liver disease. Here, in a chronic plus single-binge ethanol consumption mouse model, we observed that NK cells and interferon-γ (IFN-γ protected against ethanol-induced liver steatosis, as both wild-type (WT mice treated with anti-asialo GM1 antibody and IFN-γ-deficient GKO mice developed more severe alcoholic fatty livers. As expected, IFN-γ could directly downregulate lipogenesis in primary hepatocytes in vitro. On the contrary, iNKT cell-deficient Jα18−/− or interleukin-10 (IL-10−/− mice showed fewer alcoholic steatosis, along with the recovered number and IFN-γ release of hepatic NK cells, and exogenous IL-10 injection was sufficient to compensate for iNKT cell deficiency. Furthermore, NK cell depletion in Jα18−/− or IL-10−/− mice caused more severe hepatosteatosis, implying NK cells are the direct effector cells to inhibit liver steatosis. Importantly, adoptive transfer of iNKT cells purified from normal but not IL-10−/− mice resulted in suppression of the number and functions of NK cells and aggravated alcoholic liver injury in Jα18−/− mice, indicating that IL-10-producing iNKT (NKT10 cells are the regulators on NK cells. Conclusion: Ethanol exposure-triggered NKT10 cells antagonize the protective roles of NK cells in alcoholic hepatosteatosis.

  17. Ultraviolet damage in solar cell assemblies with various UV filters

    Science.gov (United States)

    Meulenberg, A., Jr.

    1977-01-01

    Ultraviolet damage to the new violet and non-reflective type solar cell assemblies, was studied, and potential advantages of using coverslides with no filters or filters with cut-off wavelengths below 0.35 micron were determined. The experiments consisted of three types of tests on fused silica coverslides with 0.35- and 0.30-micron cut-off filters and no cut-off filters, as well as on ceria-doped microsheet coverslides. Ultraviolet irradiation for over 1500 hours at one sun conditions (AMO) was carried out under vacuum of about 1 million torr. Nearly identical results for non-reflective type cells with 0.35-micro cut-off filters or ceria-doped coverslides were obtained. The 0.30-um filtered cell shows greater than average degradation. The unfiltered cell shows an abrupt drop in the first 20 UVSH and very little subsequent degradation.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-06-13

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

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

    International Nuclear Information System (INIS)

    Akakura, Shin; Ostrakhovitch, Elena; Sanokawa-Akakura, Reiko; Tabibzadeh, Siamak

    2014-01-01

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

  20. HMGB1 enhances immune suppression by facilitating the differentiation and suppressive activity of myeloid-derived suppressor cells.

    Science.gov (United States)

    Parker, Katherine H; Sinha, Pratima; Horn, Lucas A; Clements, Virginia K; Yang, Huan; Li, Jianhua; Tracey, Kevin J; Ostrand-Rosenberg, Suzanne

    2014-10-15

    Chronic inflammation often precedes malignant transformation and later drives tumor progression. Likewise, subversion of the immune system plays a role in tumor progression, with tumoral immune escape now well recognized as a crucial hallmark of cancer. Myeloid-derived suppressor cells (MDSC) are elevated in most individuals with cancer, where their accumulation and suppressive activity are driven by inflammation. Thus, MDSCs may define an element of the pathogenic inflammatory processes that drives immune escape. The secreted alarmin HMGB1 is a proinflammatory partner, inducer, and chaperone for many proinflammatory molecules that MDSCs develop. Therefore, in this study, we examined HMGB1 as a potential regulator of MDSCs. In murine tumor systems, HMGB1 was ubiquitous in the tumor microenvironment, activating the NF-κB signal transduction pathway in MDSCs and regulating their quantity and quality. We found that HMGB1 promotes the development of MDSCs from bone marrow progenitor cells, contributing to their ability to suppress antigen-driven activation of CD4(+) and CD8(+) T cells. Furthermore, HMGB1 increased MDSC-mediated production of IL-10, enhanced crosstalk between MDSCs and macrophages, and facilitated the ability of MDSCs to downregulate expression of the T-cell homing receptor L-selectin. Overall, our results revealed a pivotal role for HMGB1 in the development and cancerous contributions of MDSCs. ©2014 American Association for Cancer Research.

  1. Reconstitution of the cellular response to DNA damage in vitro using damage-activated extracts from mammalian cells

    International Nuclear Information System (INIS)

    Roper, Katherine; Coverley, Dawn

    2012-01-01

    In proliferating mammalian cells, DNA damage is detected by sensors that elicit a cellular response which arrests the cell cycle and repairs the damage. As part of the DNA damage response, DNA replication is inhibited and, within seconds, histone H2AX is phosphorylated. Here we describe a cell-free system that reconstitutes the cellular response to DNA double strand breaks using damage-activated cell extracts and naïve nuclei. Using this system the effect of damage signalling on nuclei that do not contain DNA lesions can be studied, thereby uncoupling signalling and repair. Soluble extracts from G1/S phase cells that were treated with etoposide before isolation, or pre-incubated with nuclei from etoposide-treated cells during an in vitro activation reaction, restrain both initiation and elongation of DNA replication in naïve nuclei. At the same time, H2AX is phosphorylated in naïve nuclei in a manner that is dependent upon the phosphatidylinositol 3-kinase-like protein kinases. Notably, phosphorylated H2AX is not focal in naïve nuclei, but is evident throughout the nucleus suggesting that in the absence of DNA lesions the signal is not amplified such that discrete foci can be detected. This system offers a novel screening approach for inhibitors of DNA damage response kinases, which we demonstrate using the inhibitors wortmannin and LY294002. -- Highlights: ► A cell free system that reconstitutes the response to DNA damage in the absence of DNA lesions. ► Damage-activated extracts impose the cellular response to DNA damage on naïve nuclei. ► PIKK-dependent response impacts positively and negatively on two separate fluorescent outputs. ► Can be used to screen for inhibitors that impact on the response to damage but not on DNA repair. ► LY294002 and wortmannin demonstrate the system's potential as a pathway focused screening approach.

  2. Neuroprotective Effects of Butanol Fraction of Cordyceps cicadae on Glutamate-Induced Damage in PC12 Cells Involving Oxidative Toxicity.

    Science.gov (United States)

    Wang, Dan; Wang, Jibiao; Wang, Dujun; Yu, Xiaofeng; Olatunji, Opeyemi Joshua; Ouyang, Zhen; Wei, Yuan

    2018-01-01

    The current study was aimed at investigating the neuroprotective effects of the butanol fraction from Cordyceps cicadae (C BU ), which was responsible for the anti-aging effect of this medicine. Glutamate-induced PC12 cells were used as a model to determine the neuroprotective effect against oxidative cell death. Cell viability, cytotoxicity, flow cytometry, mitochondrial transmembrane potential (MMP), reactive oxygen species (ROS), glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) levels were analyzed to assess neuronal cell survival or death. The results obtained from the above evaluations showed that C BU was the most effective fraction and even better than pure compounds present in C. cicadae in terms of suppressing glutamate-induced damage in PC12 cells, increasing cell viability, decreasing lactase dehydrogenase (LDH) release, and reduction of apoptosis induced by exposure to glutamate. Furthermore, C BU protected cells against mitochondrial dysfunction and oxidative stress as indicated by the suppression of ROS accumulation and up regulation of the levels of GSH-Px and SOD. In summary, the above results showed that C BU exerted neuroprotective effect against oxidative damage, and this activity could be partly due to the action of nucleosides present in the C BU . © 2018 Wiley-VHCA AG, Zurich, Switzerland.

  3. Circulating endothelial cells: a potential parameter of organ damage in sickle cell anemia?

    NARCIS (Netherlands)

    Strijbos, Michiel H.; Landburg, Precious P.; Nur, Erfan; Teerlink, Tom; Leebeek, Frank W. G.; Rijneveld, Anita W.; Biemond, Bart J.; Sleijfer, Stefan; Gratama, Jan W.; Duits, Ashley J.; Schnog, John-John B.

    2009-01-01

    Objective laboratory tools are needed to monitor developing organ damage in sickle cell disease (SCD). Circulating endothelial cells (CECs) are indicative of vascular injury. We determined whether elevated CEC can be detected in asymptomatic SCD with the CellSearch system and whether the CEC count

  4. Sensitization of ultraviolet radiation damage in bacteria and mammalian cells

    International Nuclear Information System (INIS)

    Fisher, G.J.; Watts, M.E.; Patel, K.B.; Adams, G.E.

    1978-01-01

    Bacteria (Serratia marcescens) and mammalian cells (Chinese hamsters V79-379A) were irradiated in monolayers with ultraviolet light at 254 nm or 365 nm in the presence or absence of radiosensitizing drugs. At 254 nm, killing is very efficient (Dsub(37) approximately equal 1 J m -2 exposure, or approximately equal 6 x 10 4 photons absorbed by DNA per bacterium), and sensitizers have no effect. At 365 nm, cells are not killed in buffer, but are inactivated in the presence of nifurpipone or misonidazole. Lethal exposures (approximately equal 5 x 10 3 J m -2 at 10 nM misonidazole) correspond to about 10 7 photons absorbed by sensitizer molecules per bacterium. Toxicity of stable photoproducts of the drugs is not involved, nor is oxygen required. Hence the transient species formed by photo-excitation of radiosensitizer molecules are capable of killing cells in the absence of other types of radiation damage. (author)

  5. Carbon monoxide alleviates lipopolysaccharide-induced oxidative stress injury through suppressing the expression of Fis1 in NR8383 cells

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Jia [Department of Anesthesiology, Tianjin Nankai Hospital, Tianjin Medical University, Tianjin 300100 (China); Yu, Jian-bo, E-mail: yujianbo11@126.com [Department of Anesthesiology, Tianjin Nankai Hospital, Tianjin Medical University, Tianjin 300100 (China); Liu, Wei; Wang, Dan; Zhang, Yuan; Gong, Li-rong; Dong, Shu-an [Department of Anesthesiology, Tianjin Nankai Hospital, Tianjin Medical University, Tianjin 300100 (China); Liu, Da-quan [Department of Pharmacology, Institute of Acute Abdominal Diseases of Integrated Traditional Chinese and Western Medicine, Tianjin 300100 (China)

    2016-11-15

    Acute respiratory distress syndrome (ARDS) is one of the most devastating complications of sepsis lacking of effective therapy. Mitochondrial dynamics undergoing continuous fusion and fission play a crucial role in mitochondrial structure and function. Fis1, as a small protein located on the outer membrane of mitochondria, has been thought to be an important protein mediated mitochondrial fission. During ARDS, alveolar macrophages suffer from increased oxidative stress and apoptosis, and also accompanied by disrupted mitochondrial dynamics. In addition, as one of the products of heme degradation catalyzed by heme oxygenase, carbon monoxide (CO) possesses powerful protective properties in vivo or in vitro models, such as anti-inflammatory, antioxidant and anti-apoptosis function. However, there is little evidence that CO alleviates oxidative stress damage through altering mitochondrial fission in alveolar macrophages. In the present study, our results showed that CO increased cell vitality, improved mitochondrial SOD activity, reduced reactive oxygen species (ROS) production and inhibited cell apoptosis in NR8383 exposed to LPS. Meanwhile, CO decreased the expression of Fis1, increased mitochondrial membrane potential and sustained elongation of mitochondria in LPS-incubated NR8383. Overall, our study underscored a critical role of CO in suppressing the expression of Fis1 and alleviating LPS- induced oxidative stress damage in alveolar macrophages. - Highlights: • LPS exposure triggered cell injury in NR8383. • CO alleviated LPS-induced oxidative stress damage in alveolar macrophages. • CO inhibited Fis1 levels and improved mitochondrial function in LPS-induced NR8383.

  6. DNA Damage Response in Hematopoietic Stem Cell Ageing.

    Science.gov (United States)

    Li, Tangliang; Zhou, Zhong-Wei; Ju, Zhenyu; Wang, Zhao-Qi

    2016-06-01

    Maintenance of tissue-specific stem cells is vital for organ homeostasis and organismal longevity. Hematopoietic stem cells (HSCs) are the most primitive cell type in the hematopoietic system. They divide asymmetrically and give rise to daughter cells with HSC identity (self-renewal) and progenitor progenies (differentiation), which further proliferate and differentiate into full hematopoietic lineages. Mammalian ageing process is accompanied with abnormalities in the HSC self-renewal and differentiation. Transcriptional changes and epigenetic modulations have been implicated as the key regulators in HSC ageing process. The DNA damage response (DDR) in the cells involves an orchestrated signaling pathway, consisting of cell cycle regulation, cell death and senescence, transcriptional regulation, as well as chromatin remodeling. Recent studies employing DNA repair-deficient mouse models indicate that DDR could intrinsically and extrinsically regulate HSC maintenance and play important roles in tissue homeostasis of the hematopoietic system. In this review, we summarize the current understanding of how the DDR determines the HSC fates and finally contributes to organismal ageing. Copyright © 2016 The Authors. Production and hosting by Elsevier Ltd.. All rights reserved.

  7. Autophagy protects gastric mucosal epithelial cells from ethanol-induced oxidative damage via mTOR signaling pathway.

    Science.gov (United States)

    Chang, Weilong; Bai, Jie; Tian, Shaobo; Ma, Muyuan; Li, Wei; Yin, Yuping; Deng, Rui; Cui, Jinyuan; Li, Jinjin; Wang, Guobin; Zhang, Peng; Tao, Kaixiong

    2017-05-01

    Alcohol abuse is an important cause of gastric mucosal epithelial cell injury and gastric ulcers. A number of studies have demonstrated that autophagy, an evolutionarily conserved cellular mechanism, has a protective effect on cell survival. However, it is not known whether autophagy can protect gastric mucosal epithelial cells against the toxic effects of ethanol. In the present study, gastric mucosal epithelial cells (GES-1 cells) and Wistar rats were treated with ethanol to detect the adaptive response of autophagy. Our results demonstrated that ethanol exposure induced gastric mucosal epithelial cell damage, which was accompanied by the downregulation of mTOR signaling pathway and activation of autophagy. Suppression of autophagy with pharmacological agents resulted in a significant increase of GES-1 cell apoptosis and gastric mucosa injury, suggesting that autophagy could protect cells from ethanol toxicity. Furthermore, we evaluated the cellular oxidative stress response following ethanol treatment and found that autophagy induced by ethanol inhibited generation of reactive oxygen species and degradation of antioxidant and lipid peroxidation. In conclusion, these findings provide evidence that ethanol can activate autophagy via downregulation of the mTOR signaling pathway, serving as an adaptive mechanism to ameliorate oxidative damage induced by ethanol in gastric mucosal epithelial cells. Therefore, modifying autophagy may provide a therapeutic strategy against alcoholic gastric mucosa injury. Impact statement The effect and mechanism of autophagy on ethanol-induced cell damage remain controversial. In this manuscript, we report the results of our study demonstrating that autophagy can protect gastric mucosal epithelial cells against ethanol toxicity in vitro and in vivo. We have shown that ethanol can activate autophagy via downregulation of the mTOR signaling pathway, serving as an adaptive mechanism to ameliorate ethanol-induced oxidative damage in

  8. UV Damage-Induced Phosphorylation of HBO1 Triggers CRL4DDB2-Mediated Degradation To Regulate Cell Proliferation

    Science.gov (United States)

    Matsunuma, Ryoichi; Ohhata, Tatsuya; Kitagawa, Kyoko; Sakai, Satoshi; Uchida, Chiharu; Shiotani, Bunsyo; Matsumoto, Masaki; Nakayama, Keiichi I.; Ogura, Hiroyuki; Shiiya, Norihiko; Kitagawa, Masatoshi

    2015-01-01

    Histone acetyltransferase binding to ORC-1 (HBO1) is a critically important histone acetyltransferase for forming the prereplicative complex (pre-RC) at the replication origin. Pre-RC formation is completed by loading of the MCM2-7 heterohexameric complex, which functions as a helicase in DNA replication. HBO1 recruited to the replication origin by CDT1 acetylates histone H4 to relax the chromatin conformation and facilitates loading of the MCM complex onto replication origins. However, the acetylation status and mechanism of regulation of histone H3 at replication origins remain elusive. HBO1 positively regulates cell proliferation under normal cell growth conditions. Whether HBO1 regulates proliferation in response to DNA damage is poorly understood. In this study, we demonstrated that HBO1 was degraded after DNA damage to suppress cell proliferation. Ser50 and Ser53 of HBO1 were phosphorylated in an ATM/ATR DNA damage sensor-dependent manner after UV treatment. ATM/ATR-dependently phosphorylated HBO1 preferentially interacted with DDB2 and was ubiquitylated by CRL4DDB2. Replacement of endogenous HBO1 in Ser50/53Ala mutants maintained acetylation of histone H3K14 and impaired cell cycle regulation in response to UV irradiation. Our findings demonstrate that HBO1 is one of the targets in the DNA damage checkpoint. These results show that ubiquitin-dependent control of the HBO1 protein contributes to cell survival during UV irradiation. PMID:26572825

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

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  10. Complete suppression of in vivo growth of human leukemia cells by specific immunotoxins: nude mouse models

    International Nuclear Information System (INIS)

    Hara, H.; Seon, B.K.

    1987-01-01

    In this study, immunotoxins containing monoclonal anti-human T-cell leukemia antibodies are shown to be capable of completely suppressing the tumor growth of human T-cell leukemia cells in vivo without any overt undersirable toxicity. These immunotoxins were prepared by conjugating ricin A chain (RA) with our monoclonal antibodies, SN1 and SN2, directed specifically to the human T-cell leukemia cell surface antigens TALLA and GP37, respectively. The authors have shown that these monoclonal antibodies are highly specific for human T-cell leukemia cells and do not react with various normal cells including normal T and B cells, thymocytes, and bone marrow cells. Ascitic and solid human T-cell leukemia cell tumors were generated in nude mice. The ascitic tumor was generated by transplanting Ichikawa cells (a human T-cell leukemia cell) i.p. into nude mice, whereas the solid tumor was generated by transplanting s.c. MOLT-4 cells (a human T-cell leukemia cell line) and x-irradiated human fibrosarcoma cells into x-irradiated nude mice. To investigate the efficacy of specific immunotoxins in suppression the in vivo growth of the ascitic tumor, they divided 40 nude mice that were injected with Ichikawa cells into four groups. None of the mice in group 4 that were treated with SN1-RA and SN2-RA showed any signs of a tumor or undesirable toxic effects for the 20 weeks that they were followed after the transplantation. Treatment with SN1-RA plus SN2-RA completely suppressed solid tumor growth in 4 of 10 nude mice carrying solid tumors and partially suppressed the tumor growth in the remaining 6 nude mice. These results strongly suggest that SN1-RA and SN2-RA may be useful for clinical treatment

  11. Bergenin suppresses the growth of colorectal cancer cells by ...

    African Journals Online (AJOL)

    It also led to marked accumulation of intracellular reactive oxygen species (ROS), a breaker of DNA strand in HCT116 cells. ..... regulating cell proliferation described in the literature have been related to malignant transformation [12]. Thus, we assumed that bergenin-induced cell growth inhibition was due to cell cycle arrest.

  12. Bergenin suppresses the growth of colorectal cancer cells by ...

    African Journals Online (AJOL)

    Purpose: To investigate anticancer effects of bergenin on human colorectal cancer cell lines. Methods: Human colorectal adenocarcinoma cell line HCT116 was treated with various concentrations of bergenin for 24 and 48 h. Cell viability, apoptosis, cell cycle arrest and reactive oxygen species (ROS) level were analyzed ...

  13. Puerarin may protect against Schwann cell damage induced by glucose fluctuation.

    Science.gov (United States)

    Xue, Bing; Wang, Lin; Zhang, Zhe; Wang, Rui; Xia, Xin-Xin; Han, Ping-Ping; Cao, Li-Jun; Liu, Yong-Hui; Sun, Lian-Qing

    2017-07-01

    Puerarin is one of the major active ingredients in Gegen, a traditional Chinese herb that has been reported to have a wide variety of beneficial pharmacology functions. Previous studies have implicated that the damaging effects of hyperglycemia resulting from oxidative stress and glucose fluctuation may be more dangerous than constant high glucose in the development of diabetes-related complications. The present study focuses on the effects of puerarin on glucose fluctuation-induced oxidative stress-induced Schwann cell (SC) apoptosis in vitro. Primarily cultured SCs were exposed to different conditions and the effect of puerarin on cell viability was determined by MTT assays. Intracellular reactive oxygen species (ROS) generation and mitochondrial transmembrane potential were detected by flow cytometry analysis. Apoptosis was confirmed by the Annexin V-FITC/PI and TUNEL method. Quantitative real-time reverse transcriptase polymerase chain reaction was performed to analyze the expression levels of bax and bcl-2. Western blot was performed to analyze the expression levels of some important transcription factors and proteins. The results showed that incubating SCs with intermittent high glucose for 48 h decreased cell viability and increased the number of apoptotic cells whereas treating with puerarin protected SCs against glucose fluctuation-induced cell damage. Further study demonstrated that puerarin suppressed activation of apoptosis-related proteins including PARP and caspase-3, downregulation of bcl-2, and upregulation of intracellular distribution of bax from cytosol to mitochondria, which was induced by glucose fluctuation. Moreover, puerarin inhibited the elevation of intracellular ROS and mitochondrial depolarization induced by glucose fluctuation. These results suggest that puerarin may protect SCs against glucose fluctuation-induced cell injury through inhibiting apoptosis as well as oxidative stress.

  14. Coriandrum sativum Suppresses Aβ42-Induced ROS Increases, Glial Cell Proliferation, and ERK Activation.

    Science.gov (United States)

    Liu, Quan Feng; Jeong, Haemin; Lee, Jang Ho; Hong, Yoon Ki; Oh, Youngje; Kim, Young-Mi; Suh, Yoon Seok; Bang, Semin; Yun, Hye Sup; Lee, Kyungho; Cho, Sung Man; Lee, Sung Bae; Jeon, Songhee; Chin, Young-Won; Koo, Byung-Soo; Cho, Kyoung Sang

    2016-01-01

    Alzheimer's disease (AD), the most common neurodegenerative disease, has a complex and widespread pathology that is characterized by the accumulation of amyloid [Formula: see text]-peptide (A[Formula: see text]) in the brain and various cellular abnormalities, including increased oxidative damage, an amplified inflammatory response, and altered mitogen-activated protein kinase signaling. Based on the complex etiology of AD, traditional medicinal plants with multiple effective components are alternative treatments for patients with AD. In the present study, we investigated the neuroprotective effects of an ethanol extract of Coriandrum sativum (C. sativum) leaves on A[Formula: see text] cytotoxicity and examined the molecular mechanisms underlying the beneficial effects. Although recent studies have shown the benefits of the inhalation of C. sativum oil in an animal model of AD, the detailed molecular mechanisms by which C. sativum exerts its neuroprotective effects are unclear. Here, we found that treatment with C. sativum extract increased the survival of both A[Formula: see text]-treated mammalian cells and [Formula: see text]42-expressing flies. Moreover, C. sativum extract intake suppressed [Formula: see text]-induced cell death in the larval imaginal disc and brain without affecting A[Formula: see text]42 expression and accumulation. Interestingly, the increases in reactive oxygen species levels and glial cell number in AD model flies were reduced by C. sativum extract intake. Additionally, C. sativum extract inhibited the epidermal growth factor receptor- and A[Formula: see text]-induced phosphorylation of extracellular signal-regulated kinase (ERK). The constitutively active form of ERK abolished the protective function of C. sativum extract against the [Formula: see text]-induced eye defect phenotype in Drosophila. Taken together, these results suggest that C. sativum leaves have antioxidant, anti-inflammatory, and ERK signaling inhibitory properties that

  15. Suppression of the cell proliferation in stomach cancer cells by the ZNRD1 gene

    International Nuclear Information System (INIS)

    Hong Liu; Zhang Yumei; Liu Na; Liu Changjiang; Zhi Min; Pan Yanglin; Lan Mei; Sun Li; Fan Daiming

    2004-01-01

    Zinc ribbon domain-containing 1 (ZNRD1), a transcription-associated gene, was recently found to be downregulated in human gastric cancer tissues as compared to the matched adjacent nonneoplastic tissues. In this study, we constructed the siRNA eukaryotic expression vectors of ZNRD1 and transfected them into normal gastric epithelial cells (GES-1). We also introduced the ZNRD1 gene into gastric cancer cells that do (SGC7901) and do not (AGS) express ZNRD1 endogenously. GES-1 cells stably transfected with the ZNRD1-RNAi were found to exhibit significantly quicker proliferation than empty vector transfectants. AGS cells stably transfected with the ZNRD1 cDNA exhibited significantly decreased growth rate as compared to control vector transfectants, whereas SGC7901 cells did not. Furthermore, ZNRD1 suppresses growth of AGS cells in soft agar and tumor formation in athymic nude mice. This study clearly demonstrates that ZNRD1 may play an important role in the control of human gastric cancer development by regulating cell proliferation. These results provide new insights into the function of ZNRD1 and further validate ZNRD1 as a potential therapeutic target in gastric cancer

  16. Immunotherapy: Shifting the Balance of Cell-Mediated Immunity and Suppression in Human Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Tucker, Jo A.; Jochems, Caroline [Laboratory of Tumor Immunology and Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892 (United States); Gulley, James L. [Laboratory of Tumor Immunology and Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892 (United States); Medical Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892 (United States); Schlom, Jeffrey, E-mail: js141c@nih.gov; Tsang, Kwong Y. [Laboratory of Tumor Immunology and Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892 (United States)

    2012-12-11

    Active immunotherapy is dependent on the ability of the immune system to recognize and respond to tumors. Despite overwhelming evidence to support a cell-mediated immune response to prostate cancer, it is insufficient to eradicate the disease. This is likely due to a high level of suppression at the tumor site from a variety of sources, including immunosuppressive cells. Immune cells entering the tumor microenvironment may be inhibited directly by the tumor, stromal cells or other immune cells that have been induced to adopt a suppressive phenotype. The resurgence of interest in immunotherapy following the approval of sipuleucel-T and ipilimumab by the Food and Drug Administration has brought about new strategies for overcoming tumor-mediated suppression and bolstering anti-tumor responses. Improved understanding of the immune response to prostate cancer can lead to new combination therapies, such as the use of vaccine with small molecule and checkpoint inhibitors or other immunotherapies.

  17. Immunotherapy: Shifting the Balance of Cell-Mediated Immunity and Suppression in Human Prostate Cancer

    International Nuclear Information System (INIS)

    Tucker, Jo A.; Jochems, Caroline; Gulley, James L.; Schlom, Jeffrey; Tsang, Kwong Y.

    2012-01-01

    Active immunotherapy is dependent on the ability of the immune system to recognize and respond to tumors. Despite overwhelming evidence to support a cell-mediated immune response to prostate cancer, it is insufficient to eradicate the disease. This is likely due to a high level of suppression at the tumor site from a variety of sources, including immunosuppressive cells. Immune cells entering the tumor microenvironment may be inhibited directly by the tumor, stromal cells or other immune cells that have been induced to adopt a suppressive phenotype. The resurgence of interest in immunotherapy following the approval of sipuleucel-T and ipilimumab by the Food and Drug Administration has brought about new strategies for overcoming tumor-mediated suppression and bolstering anti-tumor responses. Improved understanding of the immune response to prostate cancer can lead to new combination therapies, such as the use of vaccine with small molecule and checkpoint inhibitors or other immunotherapies

  18. Relationship between radiation damage on biomembranes and the cell killing

    International Nuclear Information System (INIS)

    Sato, Chikako

    1978-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-02-10

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

  20. Veto cell suppression mechanisms in the prevention of allograft rejection

    DEFF Research Database (Denmark)

    Jacobsen, I M; Claesson, Mogens Helweg

    1998-01-01

    on the surface of the veto-active cell. Data from a large number of experimental and clinical studies strongly indicate that veto-active cells function in vivo and are capable of preventing allograft rejection. Thus, donor-cell-mediated veto activity is the most likely explanation for the well-known graft...

  1. iNKT cells suppress the CD8+ T cell response to a murine Burkitt's-like B cell lymphoma.

    Directory of Open Access Journals (Sweden)

    Ryan L Bjordahl

    Full Text Available The T cell response to B cell lymphomas differs from the majority of solid tumors in that the malignant cells themselves are derived from B lymphocytes, key players in immune response. B cell lymphomas are therefore well situated to manipulate their surrounding microenvironment to enhance tumor growth and minimize anti-tumor T cell responses. We analyzed the effect of T cells on the growth of a transplantable B cell lymphoma and found that iNKT cells suppressed the anti-tumor CD8(+ T cell response. Lymphoma cells transplanted into syngeneic wild type (WT mice or Jalpha18(-/- mice that specifically lack iNKT cells grew initially at the same rate, but only the mice lacking iNKT cells were able to reject the lymphoma. This effect was due to the enhanced activity of tumor-specific CD8(+ T cells in the absence of iNKT cells, and could be partially reversed by reconstitution of iNKT cells in Jalpha 18(-/- mice. Treatment of tumor-bearing WT mice with alpha -galactosyl ceramide, an activating ligand for iNKT cells, reduced the number of tumor-specific CD8(+ T cells. In contrast, lymphoma growth in CD1d1(-/- mice that lack both iNKT and type II NKT cells was similar to that in WT mice, suggesting that type II NKT cells are required for full activation of the anti-tumor immune response. This study reveals a tumor-promoting role for iNKT cells and suggests their capacity to inhibit the CD8(+ T cell response to B cell lymphoma by opposing the effects of type II NKT cells.

  2. Immunoregulatory adherent cells in human tuberculosis: radiation-sensitive antigen-specific suppression by monocytes

    Energy Technology Data Exchange (ETDEWEB)

    Kleinhenz, M.E.; Ellner, J.J.

    1985-07-01

    In human tuberculosis, adherent mononuclear cells (AMC) selectively depress in vitro responses to the mycobacterial antigen tuberculin purified protein derivative (PPD). The phenotype of this antigen-specific adherent suppressor cell was characterized by examining the functional activity of adherent cells after selective depletion of sheep erythrocyte-rosetting T cells or OKM1-reactive monocytes. Adherent cell suppression was studied in the (/sup 3/H)thymidine-incorporation microculture assay by using T cells rigorously depleted of T cells with surface receptors for the Fc portion of IgG (T gamma cells) as antigen-responsive cells. PPD-induced (/sup 3/H)thymidine incorporation by these non gamma T cells was uniformly reduced (mean, 42% +/- 10% (SD)) when autologous AMC were added to non gamma T cells at a ratio of 1:2. Antigen-specific suppression by AMC was not altered by depletion of sheep erythrocyte-rosetting T cells or treatment with indomethacin. However, AMC treated with OKM1 and complement or gamma irradiation (1,500 rads) no longer suppressed tuberculin responses in vitro. These studies identify the antigen-specific adherent suppressor cell in tuberculosis as an OKM1-reactive, non-erythrocyte-rosetting monocyte. The radiosensitivity of this monocyte immunoregulatory function may facilitate its further definition.

  3. Immunoregulatory adherent cells in human tuberculosis: radiation-sensitive antigen-specific suppression by monocytes

    International Nuclear Information System (INIS)

    Kleinhenz, M.E.; Ellner, J.J.

    1985-01-01

    In human tuberculosis, adherent mononuclear cells (AMC) selectively depress in vitro responses to the mycobacterial antigen tuberculin purified protein derivative (PPD). The phenotype of this antigen-specific adherent suppressor cell was characterized by examining the functional activity of adherent cells after selective depletion of sheep erythrocyte-rosetting T cells or OKM1-reactive monocytes. Adherent cell suppression was studied in the [ 3 H]thymidine-incorporation microculture assay by using T cells rigorously depleted of T cells with surface receptors for the Fc portion of IgG (T gamma cells) as antigen-responsive cells. PPD-induced [ 3 H]thymidine incorporation by these non gamma T cells was uniformly reduced (mean, 42% +/- 10% [SD]) when autologous AMC were added to non gamma T cells at a ratio of 1:2. Antigen-specific suppression by AMC was not altered by depletion of sheep erythrocyte-rosetting T cells or treatment with indomethacin. However, AMC treated with OKM1 and complement or gamma irradiation (1,500 rads) no longer suppressed tuberculin responses in vitro. These studies identify the antigen-specific adherent suppressor cell in tuberculosis as an OKM1-reactive, non-erythrocyte-rosetting monocyte. The radiosensitivity of this monocyte immunoregulatory function may facilitate its further definition

  4. Myeloid-derived suppressor cells mediate immune suppression in spinal cord injury.

    Science.gov (United States)

    Wang, Lei; Yu, Wei-bo; Tao, Lian-yuan; Xu, Qing

    2016-01-15

    Spinal cord injury (SCI) is characterized by the loss of motor and sensory functions in areas below the level of the lesion and numerous accompanying deficits. Previous studies have suggested that myeloid-derived suppressor cell (MDSC)-induced immune depression may play a pivotal role in the course of SCI. However, the concrete mechanism of these changes regarding immune suppression remains unknown. Here, we created an SCI mouse model to gain further evidence regarding the relationship between MDSCs following SCI and T lymphocyte suppression. We showed that in the SCI mouse model, the expanding MDSCs have the capacity to suppress T cell proliferation, and this suppression could be reversed by blocking the arginase. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Diallyl trisulfide (DATS) suppresses benzene-induced cytopenia by modulating haematopoietic cell apoptosis.

    Science.gov (United States)

    Han, Wenting; Wang, Shuo; Jiang, Lulu; Wang, Hui; Li, Ming; Wang, Xujing; Xie, Keqin

    2017-12-01

    Benzene is a well-known occupational and environmental toxicant associated with cytopenia, which is characterized by a disorder in the peripheral blood cell counts. However, no effective preventive strategy has been developed yet to tackle the exposure to benzene in daily life. The aim of this study was to evaluate the protective effects of diallyl trisulfide (DATS) on benzene-induced haematopoietic damage and to reveal its potential mechanisms of action. In our study, male Sprague-Dawley rats were divided into six groups. Rats were administered with benzene (1.3 g/kg BW by gavage) to establish the benzene poisoning model, while the DATS treatment groups were treated with benzene plus DATS (15 mg/kg, 30 mg/kg, 45 mg/kg, respectively, by gavage) for 28 days. Our results demonstrated that the counts of peripheral blood WBC and RBC decreased to 31.0% and 79.2%, respectively, in the benzene poisoning model group compared to the control. However, blood cell counts were restored by DATS treatment (30 mg/kg, 45 mg/kg). The apoptosis rates of peripheral blood mononuclear cells (PBMCs) and bone marrow cells (BMCs) were increased to 274% and 284%, respectively, following benzene exposure. Furthermore, expression levels of Bcl-2, PI3K and p-Akt were downregulated and those of Bax were upregulated in both cell types. Moreover, the oxidative parameters (oxygen species, malonaldehyde) were significantly increased, while the non-enzymatic GSH/GSSG ratios and the activities of enzymatic antioxidants (superoxide dismutase, glutathione peroxidase and catalase) were decreased. Interestingly, DATS treatment can restore the WBC number by 267.1% and 304.8% while RBC number by 108.6% and 117.7% in 30,45 mg/k DATS treated groups. In summary, we demonstrated that benzene-induced cytopenia was related to the apoptosis of PBMCs and BMCs, and DATS treatment could prevent benzene-induced cytopenia by suppressing oxidative stress-mediated cell apoptosis via the PI3K/Akt pathway. Copyright

  6. Endothelial Cell-Targeted Adenoviral Vector for Suppressing Breast Tumors

    National Research Council Canada - National Science Library

    Huang, Shuang

    2003-01-01

    .... We incorporated five previously published endothelial cell-specific peptide sequences into adenovirus capsid fiber sequence and the modified fibers were added to Beta-galactosidase- containing...

  7. Sparged animal cell bioreactors: mechanism of cell damage and Pluronic F-68 protection.

    Science.gov (United States)

    Murhammer, D W; Goochee, C F

    1990-01-01

    Pluronic F-68 is a widely used protective agent in sparged animal cell bioreactors. In this study, the attachment-independent Spodoptera frugiperda Sf9 insect cell line was used to explore the mechanism of this protective effect and the nature of cell damage in sparged bioreactors. First, bubble incorporation via cavitation or vortexing was induced by increasing the agitation rate in a surface-aerated bioreactor; insect cells were rapidly killed under these conditions of the absence of polyols. Supplementing the medium with 0.2% (w/v) Pluronic F-68, however, fully protected the cells. Next, cell growth was compared in two airlift bioreactors with similar geometry but different sparger design; one of these bioreactors consisted of a thin membrane distributor, while the other consisted of a porous stainless steel distributor. The flow rates and bubble sizes were comparable in the two bioreactors. Supplementing the medium with 0.2% (w/v) Pluronic F-68 provided full protection to cells growing in the bioreactor with the membrane distributor but provided essentially no protection in the bioreactor with the stainless steel distributor. These results strongly suggest that cell damage can occur in the vicinity of the gas distributor. In addition, these results demonstrate that bubble size and gas flow rate are not the only important considerations of cell damage in sparged bioreactors. A model of cell death in sparged bioreactors is presented.

  8. Odorants suppress voltage-gated currents in retinal horizontal cells in goldfish.

    Science.gov (United States)

    Kawai, F; Miyachi, E

    2000-03-10

    Odorants are known to suppress non-selectively voltage-gated currents in olfactory receptor cells. We found that odorants also suppress voltage-gated currents in neurons of outside of the olfactory system. Under voltage clamp, odorants such as amyl acetate, limonene, and acetophenone suppressed non-selectively voltage-gated currents (a Ca(2+) current, a delayed rectifier K(+) current, a fast transient K(+) current, and an anomalous rectifier K(+) current) in horizontal cells from the goldfish retina. An amyl acetate puff completely and immediately suppressed the Ca(2+) current (I(Ca)) and the delayed rectifier K(+) current induced by repetitive depolarizations, suggesting that amyl acetate is a closed-channel blocker. Odorants did not change significantly the activation curve of I(Ca), but made the slope of inactivation curve of I(Ca) gentler and shifted its half-inactivation voltage toward a negative voltage. These results are similar to the effects of odorants on voltage-gated currents in olfactory receptor cells. This suggests that odorants may suppress the voltage-gated currents in retinal horizontal cells by the same mechanism described in olfactory receptor cells.

  9. Inhibition of BRD4 Suppresses Cell Proliferation and Induces Apoptosis in Renal Cell Carcinoma

    Directory of Open Access Journals (Sweden)

    Xinchao Wu

    2017-04-01

    Full Text Available Background/Aims: Renal cell carcinoma (RCC remains an intractable genitourinary malignancy. Resistance to chemotherapy or targeted therapies in RCC is presumably due to the complicated underlying molecular mechanisms and insufficient understanding. The aim of this research was to assess the expression and role of bromodomain-4 protein (BRD4 in RCC and evaluate the effects of BRD4 inhibitor JQ1 for RCC treatment. Methods: BRD4 expressionlevels were assessed by qRT-PCR and western blot in RCC tissues and cells. The effects of BRD4 knockdown or JQ1 on RCC cells were assessed by MTT assay and flow cytometry. The effects of in vivo treatment were evaluated through xenograft experiments. Results: BRD4 is significantly overexpressed in RCC, and is related to tumor stage and lymph node metastasis. Inhibition of BRD4 suppressed RCC cell proliferation, induced cell apoptosis in vitro and repressed tumor growth in vivo. Inhibition of BRD4 decreased BCL2 and C-MYC expression while increased BAX and cleaved caspase3 expression, and strikingly diminished the recruitment of BRD4 to BCL2 promoter. Conclusions: Our research reveals that BRD4 probably play a critical role in RCC progression, and is a new promising target for pharmacological treatment directed against this intractable disease.

  10. Photodynamic damage of glial cells in crayfish ventral nerve cord

    Science.gov (United States)

    Kolosov, M. S.; Duz, E.; Uzdensky, A. B.

    2011-03-01

    Photodynamic therapy (PDT) is a promising method for treatment of brain tumors, the most of which are of glial origin. In the present work we studied PDT-mediated injury of glial cells in nerve tissue, specifically, in abdominal connectives in the crayfish ventral nerve cord. The preparation was photosensitized with alumophthalocyanine Photosens and irradiated 30 min with the diode laser (670 nm, 0.1 or 0.15 W/cm2). After following incubation in the darkness during 1- 10 hours it was fluorochromed with Hoechst 33342 and propidium iodide to reveal nuclei of living, necrotic and apoptotic cells. The chain-like location of the glial nuclei allowed visualization of those enveloping giant axons and blood vessels. The level of glial necrosis in control preparations was about 2-5 %. Apoptosis was not observed in control preparations. PDT significantly increased necrosis of glial cells to 52 or 67 % just after irradiation with 0.1 or 0.15 W/cm2, respectively. Apoptosis of glial cells was observed only at 10 hours after light exposure. Upper layers of the glial envelope of the connectives were injured stronger comparing to deep ones: the level of glial necrosis decreased from 100 to 30 % upon moving from the connective surface to the plane of the giant axon inside the connective. Survival of glial cells was also high in the vicinity of blood vessels. One can suggest that giant axons and blood vessels protect neighboring glial cells from photodynamic damage. The mechanism of such protective action remains to be elucidated.

  11. Osteoclast activated FoxP3+ CD8+ T-cells suppress bone resorption in vitro.

    Directory of Open Access Journals (Sweden)

    Zachary S Buchwald

    Full Text Available BACKGROUND: Osteoclasts are the body's sole bone resorbing cells. Cytokines produced by pro-inflammatory effector T-cells (T(EFF increase bone resorption by osteoclasts. Prolonged exposure to the T(EFF produced cytokines leads to bone erosion diseases such as osteoporosis and rheumatoid arthritis. The crosstalk between T-cells and osteoclasts has been termed osteoimmunology. We have previously shown that under non-inflammatory conditions, murine osteoclasts can recruit naïve CD8 T-cells and activate these T-cells to induce CD25 and FoxP3 (Tc(REG. The activation of CD8 T-cells by osteoclasts also induced the cytokines IL-2, IL-6, IL-10 and IFN-γ. Individually, these cytokines can activate or suppress osteoclast resorption. PRINCIPAL FINDINGS: To determine the net effect of Tc(REG on osteoclast activity we used a number of in vitro assays. We found that Tc(REG can potently and directly suppress bone resorption by osteoclasts. Tc(REG could suppress osteoclast differentiation and resorption by mature osteoclasts, but did not affect their survival. Additionally, we showed that Tc(REG suppress cytoskeletal reorganization in mature osteoclasts. Whereas induction of Tc(REG by osteoclasts is antigen-dependent, suppression of osteoclasts by Tc(REG does not require antigen or re-stimulation. We demonstrated that antibody blockade of IL-6, IL-10 or IFN-γ relieved suppression. The suppression did not require direct contact between the Tc(REG and osteoclasts. SIGNIFICANCE: We have determined that osteoclast-induced Tc(REG can suppress osteoclast activity, forming a negative feedback system. As the CD8 T-cells are activated in the absence of inflammatory signals, these observations suggest that this regulatory loop may play a role in regulating skeletal homeostasis. Our results provide the first documentation of suppression of osteoclast activity by CD8 regulatory T-cells and thus, extend the purview of osteoimmunology.

  12. Dexamethasone Suppresses Oxysterol-Induced Differentiation of Monocytic Cells

    Directory of Open Access Journals (Sweden)

    Yonghae Son

    2016-01-01

    Full Text Available Oxysterol like 27-hydroxycholesterol (27OHChol has been reported to induce differentiation of monocytic cells into a mature dendritic cell phenotype. We examined whether dexamethasone (Dx affects 27OHChol-induced differentiation using THP-1 cells. Treatment of monocytic cells with Dx resulted in almost complete inhibition of transcription and surface expression of CD80, CD83, and CD88 induced by 27OHChol. Elevated surface levels of MHC class I and II molecules induced by 27OHChol were reduced to basal levels by treatment with Dx. A decreased endocytosis ability caused by 27OHChol was recovered by Dx. We also examined effects of Dx on expression of CD molecules involved in atherosclerosis. Increased levels of surface protein and transcription of CD105, CD137, and CD166 by treatment with 27OHChol were significantly inhibited by cotreatment with Dx. These results indicate that Dx inhibits 27OHChol-induced differentiation of monocytic cells into a mature dendritic cell phenotype and expression of CD molecules whose levels are associated with atherosclerosis. In addition, we examined phosphorylation of AKT induced by 27OHChol and effect of Dx, where cotreatment with Dx inhibited the phosphorylation of AKT. The current study reports that Dx regulates oxysterol-mediated dendritic cell differentiation of monocytic cells.

  13. Suppression of vascular smooth muscle cells' proliferation and ...

    African Journals Online (AJOL)

    ajl yemi

    2011-12-26

    Dec 26, 2011 ... migration period, transwell chambers were fixed by methyl alcohol and stained by hematoxylin, and then the non-migrating cells were removed with a cotton swab from the upper surface. The number of cells that had migrated to the lower surface of the membrane was determined per ×200 high power field.

  14. Salmon cartilage proteoglycan suppresses mouse experimental colitis through induction of Foxp3+ regulatory T cells

    International Nuclear Information System (INIS)

    Mitsui, Toshihito; Sashinami, Hiroshi; Sato, Fuyuki; Kijima, Hiroshi; Ishiguro, Yoh; Fukuda, Shinsaku; Yoshihara, Shuichi; Hakamada, Ken-Ichi; Nakane, Akio

    2010-01-01

    Research highlights: → Salmon proteoglycan suppresses IL-10 -/- cell transfer-induced colitis progression. → Salmon proteoglycan suppresses Th1- and Th17-related factors in colitis mice. → Salmon proteoglycan enhances Foxp3 expression. -- Abstract: Proteoglycans (PGs) are complex glycohydrates which are widely distributed in extracellular matrix (ECM). PGs are involved in the construction of ECM, cell proliferation and differentiation. ECM components are involved in transduction of proinflammatory responses, but it is still unknown whether PGs are involved in inflammatory response. In this study, we investigated the effect of PG extracted from salmon cartilage on the progression of experimental colitis-induced in severe combined immunodeficiency mice by cell transfer from interleukin-10 (IL-10) -/- mice. IL-10 -/- cell-transferred mice showed weight loss, colon shortening and histological appearance of mild colitis. Daily oral administration of PG attenuated the clinical progression of colitis in a dose-dependent manner. Colitis-induced mice showed the elevated expression of IFN-γ, IL-12, TNF-α, IL-21, IL-23p19, IL-6, IL-17A and retinoic acid-related orphan receptor γt (RORγt) in lamina propria mononuclear cells (LPMCs) and oral administration of PG suppressed the expression of these factors. Conversely, expression of Foxp3 that induces CD4 + CD25 + regulatory T cells in LPMCs was enhanced by PG administration. These findings suggested that salmon PG attenuated the progression of colitis due to suppression of inflammatory response by enhancement of regulatory T cell induction.

  15. Gadolinium chloride suppresses hepatic oval cell proliferation in rats with biliary obstruction.

    OpenAIRE

    Olynyk, J. K.; Yeoh, G. C.; Ramm, G. A.; Clarke, S. L.; Hall, P. M.; Britton, R. S.; Bacon, B. R.; Tracy, T. F.

    1998-01-01

    Liver injury due to bile duct ligation (BDL) is histologically characterized by cholestasis, bile ductular proliferation, hepatocellular damage, portal fibrosis, and ultimately biliary cirrhosis. Stem cells within the liver may act as progenitor cells for small epithelial cells termed oval cells that can differentiate into bile duct cells or hepatocytes, whereas myofibroblasts are the principal source of collagen production in fibrosis. The aims of this study were to determine 1) whether BDL ...

  16. Reversal of Experimental Liver Damage after Transplantation of Stem-Derived Cells Detected by FTIR Spectroscopy

    Directory of Open Access Journals (Sweden)

    Danna Ye

    2017-01-01

    Full Text Available The transplantation of autologous BM-MSCs holds great potential for treating end-stage liver diseases. The aim of this study was to compare the efficiency of transplanted rBM-MSCs and rBM-MSC-derived differentiated stem cells (rBM-MSC-DSCs for suppression of dimethylnitrosamine-injured liver damage in rat model. Synchrotron radiation Fourier-transform infrared (SR-FTIR microspectroscopy was applied to investigate changes in the macromolecular composition. Transplantation of rBM-MSC-DSCs into liver-injured rats restored their serum albumin level and significantly suppressed transaminase activity as well as the morphological manifestations of liver disease. The regenerative effects of rBM-MSC-DSCs were corroborated unequivocally by the phenotypic difference analysis between liver tissues revealed by infrared spectroscopy. Spectroscopic changes in the spectral region from 1190–970 cm−1 (bands with absorbance maxima at 1150 cm−1, 1081 cm−1, and 1026 cm−1 indicated decreased levels of carbohydrates, in rBM-MSC-DSC-transplanted livers, compared with untreated and rBM-MSC--transplanted animals. Principal component analysis (PCA of spectra acquired from liver tissue could readily discriminate rBM-MSC-DSC-transplanted animals from the untreated and rBM-MSC-transplanted animals. We conclude that the transplantation of rBM-MSC-DSCs effectively treats liver disease in rats and SR-FTIR microspectroscopy provides important insights into the fundamental biochemical alterations induced by the stem-derived cell transplantation, including an objective “signature” of the regenerative effects of stem cell therapy upon liver injury.

  17. Reversing SKI-SMAD4-mediated suppression is essential for TH17 cell differentiation.

    Science.gov (United States)

    Zhang, Song; Takaku, Motoki; Zou, Liyun; Gu, Ai-di; Chou, Wei-Chun; Zhang, Ge; Wu, Bing; Kong, Qing; Thomas, Seddon Y; Serody, Jonathan S; Chen, Xian; Xu, Xiaojiang; Wade, Paul A; Cook, Donald N; Ting, Jenny P Y; Wan, Yisong Y

    2017-11-02

    T helper 17 (T H 17) cells are critically involved in host defence, inflammation, and autoimmunity. Transforming growth factor β (TGFβ) is instrumental in T H 17 cell differentiation by cooperating with interleukin-6 (refs 6, 7). Yet, the mechanism by which TGFβ enables T H 17 cell differentiation remains elusive. Here we reveal that TGFβ enables T H 17 cell differentiation by reversing SKI-SMAD4-mediated suppression of the expression of the retinoic acid receptor (RAR)-related orphan receptor γt (RORγt). We found that, unlike wild-type T cells, SMAD4-deficient T cells differentiate into T H 17 cells in the absence of TGFβ signalling in a RORγt-dependent manner. Ectopic SMAD4 expression suppresses RORγt expression and T H 17 cell differentiation of SMAD4-deficient T cells. However, TGFβ neutralizes SMAD4-mediated suppression without affecting SMAD4 binding to the Rorc locus. Proteomic analysis revealed that SMAD4 interacts with SKI, a transcriptional repressor that is degraded upon TGFβ stimulation. SKI controls histone acetylation and deacetylation of the Rorc locus and T H 17 cell differentiation via SMAD4: ectopic SKI expression inhibits H3K9 acetylation of the Rorc locus, Rorc expression, and T H 17 cell differentiation in a SMAD4-dependent manner. Therefore, TGFβ-induced disruption of SKI reverses SKI-SMAD4-mediated suppression of RORγt to enable T H 17 cell differentiation. This study reveals a critical mechanism by which TGFβ controls T H 17 cell differentiation and uncovers the SKI-SMAD4 axis as a potential therapeutic target for treating T H 17-related diseases.

  18. [Suppression of WIFI transcript and protein in non-small cell lung carcinomas].

    Science.gov (United States)

    Korobko, E V; Kalinichenko, S V; Shepelev, M V; Zborovskaia, I B; Allakhverdiev, A K; Zinov'eva, M V; Vinogradova, T V; Sverdlov, E D; Korobko, I V

    2007-01-01

    Changes in WIFI expression, an extracellular inhibitor of Wnt pathway, in non-small cell lung carcinomas were analyzed. Frequent (67% cases) suppression of WIFI transcript in non-small cell lung carcinomas were found. Our results, together with previously published data, suggest that inhibition of WIFI expression often occurs in squamous cell carcinomas and is less typical of adenocarcinomas. It was also found that a decrease in the WIFI transcript in tumors is parallel to concomitant suppression of the WIFI protein level. Our results provide further evidence that the WIFI suppression is a frequent event in the lung carcinogenesis, which might lead to disregulation of Wnt signaling pathway and contribute to tumor progression.

  19. Dutasteride and enzalutamide synergistically suppress prostate tumor cell proliferation

    NARCIS (Netherlands)

    Hamid, A.R.; Verhaegh, G.W.C.T.; Smit, F.P.; RIjt-van de Westerlo, C.; Armandari, I.; Brandt, A.; Sweep, F.C.; Sedelaar, J.P.M.; Schalken, J.A.

    2015-01-01

    PURPOSE: Dihydrotestosterone is the main active androgen in the prostate and it has a role in prostate cancer progression. After androgen deprivation therapy androgen receptor signaling is still active in tumor cells. Persistent intratumor steroidogenesis and androgen receptor changes are

  20. Endogenous DNA Damage and Risk of Testicular Germ Cell Tumors

    Energy Technology Data Exchange (ETDEWEB)

    Cook, M B; Sigurdson, A J; Jones, I M; Thomas, C B; Graubard, B I; Korde, L; Greene, M H; McGlynn, K A

    2008-01-18

    Testicular germ cell tumors (TGCT) are comprised of two histologic groups, seminomas and nonseminomas. We postulated that the possible divergent pathogeneses of these histologies may be partially explained by variable endogenous DNA damage. To assess our hypothesis, we conducted a case-case analysis of seminomas and nonseminomas using the alkaline comet assay to quantify single-strand DNA breaks and alkali-labile sites. The Familial Testicular Cancer study and the U.S. Radiologic Technologists cohort provided 112 TGCT cases (51 seminomas & 61 nonseminomas). A lymphoblastoid cell line was cultured for each patient and the alkaline comet assay was used to determine four parameters: tail DNA, tail length, comet distributed moment (CDM) and Olive tail moment (OTM). Odds ratios (OR) and 95% confidence intervals (95%CI) were estimated using logistic regression. Values for tail length, tail DNA, CDM and OTM were modeled as categorical variables using the 50th and 75th percentiles of the seminoma group. Tail DNA was significantly associated with nonseminoma compared to seminoma (OR{sub 50th percentile} = 3.31, 95%CI: 1.00, 10.98; OR{sub 75th percentile} = 3.71, 95%CI: 1.04, 13.20; p for trend=0.039). OTM exhibited similar, albeit statistically non-significant, risk estimates (OR{sub 50th percentile} = 2.27, 95%CI: 0.75, 6.87; OR{sub 75th percentile} = 2.40, 95%CI: 0.75, 7.71; p for trend=0.12) whereas tail length and CDM showed no association. In conclusion, the results for tail DNA and OTM indicate that endogenous DNA damage levels are higher in patients who develop nonseminoma compared with seminoma. This may partly explain the more aggressive biology and younger age-of-onset of this histologic subgroup compared with the relatively less aggressive, later-onset seminoma.

  1. SOCS3 in retinal neurons and glial cells suppresses VEGF signaling to prevent pathological neovascular growth.

    Science.gov (United States)

    Sun, Ye; Ju, Meihua; Lin, Zhiqiang; Fredrick, Thomas W; Evans, Lucy P; Tian, Katherine T; Saba, Nicholas J; Morss, Peyton C; Pu, William T; Chen, Jing; Stahl, Andreas; Joyal, Jean-Sébastien; Smith, Lois E H

    2015-09-22

    Neurons and glial cells in the retina contribute to neovascularization, or the formation of abnormal new blood vessels, in proliferative retinopathy, a condition that can lead to vision loss or blindness. We identified a mechanism by which suppressor of cytokine signaling 3 (SOCS3) in neurons and glial cells prevents neovascularization. We found that Socs3 expression was increased in the retinal ganglion cell and inner nuclear layers after oxygen-induced retinopathy. Mice with Socs3 deficiency in neuronal and glial cells had substantially reduced vaso-obliterated retinal areas and increased pathological retinal neovascularization in response to oxygen-induced retinopathy, suggesting that loss of neuronal/glial SOCS3 increased both retinal vascular regrowth and pathological neovascularization. Furthermore, retinal expression of Vegfa (which encodes vascular endothelial growth factor A) was higher in these mice than in Socs3 flox/flox controls, indicating that neuronal and glial SOCS3 suppressed Vegfa expression during pathological conditions. Lack of neuronal and glial SOCS3 resulted in greater phosphorylation and activation of STAT3, which led to increased expression of its gene target Vegfa, and increased endothelial cell proliferation. In summary, SOCS3 in neurons and glial cells inhibited the STAT3-mediated secretion of VEGF from these cells, which suppresses endothelial cell activation, resulting in decreased endothelial cell proliferation and angiogenesis. These results suggest that neuronal and glial cell SOCS3 limits pathological retinal angiogenesis by suppressing VEGF signaling. Copyright © 2015, American Association for the Advancement of Science.

  2. Allantoin ameliorates chemically-induced pancreatic β-cell damage through activation of the imidazoline I3 receptors

    Directory of Open Access Journals (Sweden)

    Marie Amitani

    2015-08-01

    Full Text Available Objective. Allantoin is the primary active compound in yams (Dioscorea spp.. Recently, allantoin has been demonstrated to activate imidazoline 3 (I3 receptors located in pancreatic tissues. Thus, the present study aimed to investigate the role of allantoin in the effect to improve damage induced in pancreatic β-cells by streptozotocin (STZ via the I3 receptors.Research Design and Methods. The effect of allantoin on STZ-induced apoptosis in pancreatic β-cells was examined using the ApoTox-Glo triplex assay, live/dead cell double staining assay, flow cytometric analysis, and Western blottings. The potential mechanism was investigated using KU14R: an I3 receptor antagonist, and U73122: a phospholipase C (PLC inhibitor. The effects of allantoin on serum glucose and insulin secretion were measured in STZ-treated rats.Results. Allantoin attenuated apoptosis and cytotoxicity and increased the viability of STZ-induced β-cells in a dose-dependent manner; this effect was suppressed by KU14R and U73112. Allantoin decreased the level of caspase-3 and increased the level of phosphorylated B-cell lymphoma 2 (Bcl-2 expression detected by Western blotting. The improvement in β-cells viability was confirmed using flow cytometry analysis. Daily injection of allantoin for 8 days in STZ-treated rats significantly lowered plasma glucose and increased plasma insulin levels. This action was inhibited by treatment with KU14R.Conclusion. Allantoin ameliorates the damage of β-cells induced by STZ. The blockade by pharmacological inhibitors indicated that allantoin can activate the I3 receptors through a PLC-related pathway to decrease this damage. Therefore, allantoin and related analogs may be effective in the therapy for β-cell damage.

  3. Caloric restriction suppresses apoptotic cell death in the mammalian cochlea and leads to prevention of presbycusis.

    Science.gov (United States)

    Someya, Shinichi; Yamasoba, Tatsuya; Weindruch, Richard; Prolla, Tomas A; Tanokura, Masaru

    2007-10-01

    Presbycusis is characterized by an age-related progressive decline of auditory function, and arises mainly from the degeneration of hair cells or spiral ganglion (SG) cells in the cochlea. Here we show that caloric restriction suppresses apoptotic cell death in the mouse cochlea and prevents late onset of presbycusis. Calorie restricted (CR) mice, which maintained body weight at the same level as that of young control (YC) mice, retained normal hearing and showed no cochlear degeneration. CR mice also showed a significant reduction in the number of TUNEL-positive cells and cleaved caspase-3-positive cells relative to middle-age control (MC) mice. Microarray analysis revealed that CR down-regulated the expression of 24 apoptotic genes, including Bak and Bim. Taken together, our findings suggest that loss of critical cells through apoptosis is an important mechanism of presbycusis in mammals, and that CR can retard this process by suppressing apoptosis in the inner ear tissue.

  4. Schistosoma mansoni-mediated suppression of allergic airway inflammation requires patency and Foxp3+ Treg cells.

    Directory of Open Access Journals (Sweden)

    Laura E Layland

    Full Text Available The continual rise of asthma in industrialised countries stands in strong contrast to the situation in developing lands. According to the modified Hygiene Hypothesis, helminths play a major role in suppressing bystander immune responses to allergens, and both epidemiological and experimental studies suggest that the tropical parasitic trematode Schistosoma mansoni elicits such effects. The focus of this study was to investigate which developmental stages of schistosome infection confer suppression of allergic airway inflammation (AAI using ovalbumin (OVA as a model allergen. Moreover, we assessed the functional role and localization of infection-induced CD4(+Foxp3(+ regulatory T cells (Treg in mediating such suppressive effects. Therefore, AAI was elicited using OVA/adjuvant sensitizations with subsequent OVA aerosolic challenge and was induced during various stages of infection, as well as after successful anti-helminthic treatment with praziquantel. The role of Treg was determined by specifically depleting Treg in a genetically modified mouse model (DEREG during schistosome infection. Alterations in AAI were determined by cell infiltration levels into the bronchial system, OVA-specific IgE and Th2 type responses, airway hyper-sensitivity and lung pathology. Our results demonstrate that schistosome infection leads to a suppression of OVA-induced AAI when mice are challenged during the patent phase of infection: production of eggs by fecund female worms. Moreover, this ameliorating effect does not persist after anti-helminthic treatment, and depletion of Treg reverts suppression, resulting in aggravated AAI responses. This is most likely due to a delayed reconstitution of Treg in infected-depleted animals which have strong ongoing immune responses. In summary, we conclude that schistosome-mediated suppression of AAI requires the presence of viable eggs and infection-driven Treg cells. These data provide evidence that helminth derived products

  5. Pattern-triggered immunity suppresses programmed cell death triggered by fumonisin b1.

    Directory of Open Access Journals (Sweden)

    Daisuke Igarashi

    Full Text Available Programmed cell death (PCD is a crucial process for plant innate immunity and development. In plant innate immunity, PCD is believed to prevent the spread of pathogens from the infection site. Although proper control of PCD is important for plant fitness, we have limited understanding of the molecular mechanisms regulating plant PCD. Plant innate immunity triggered by recognition of effectors (effector-triggered immunity, ETI is often associated with PCD. However pattern-triggered immunity (PTI, which is triggered by recognition of elicitors called microbe-associated molecular patterns (MAMPs, is not. Therefore we hypothesized that PTI might suppress PCD. Here we report that PCD triggered by the mycotoxin fumonisin B1 (FB1 can be suppressed by PTI in Arabidopsis. FB1-triggered cell death was suppressed by treatment with the MAMPs flg22 (a part of bacterial flagellin or elf18 (a part of the bacterial elongation factor EF-Tu but not chitin (a component of fungal cell walls. Although plant hormone signaling is associated with PCD and PTI, both FB1-triggered cell death and suppression of cell death by flg22 treatment were still observed in mutants deficient in jasmonic acid (JA, ethylene (ET and salicylic acid (SA signaling. The MAP kinases MPK3 and MPK6 are transiently activated and inactivated within one hour during PTI. We found that FB1 activated MPK3 and MPK6 about 36-48 hours after treatment. Interestingly, this late activation was attenuated by flg22 treatment. These results suggest that PTI suppression of FB1-triggered cell death may involve suppression of MPK3/MPK6 signaling but does not require JA/ET/SA signaling.

  6. Tussilagone suppresses colon cancer cell proliferation by promoting the degradation of β-catenin

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hua [College of Pharmacy and Research Center for Cell Fate Control, Sookmyung Women’s University, 52 Hyochangwon-Gil, Yongsan-Gu, Seoul 140-742 (Korea, Republic of); Lee, Hwa Jin [Department of Natural Medicine Resources, Semyung University, 65 Semyung-ro, Jecheon, Chungbuk 390-711 (Korea, Republic of); Ahn, Yeon Hwa; Kwon, Hye Jin; Jang, Chang-Young; Kim, Woo-Young [College of Pharmacy and Research Center for Cell Fate Control, Sookmyung Women’s University, 52 Hyochangwon-Gil, Yongsan-Gu, Seoul 140-742 (Korea, Republic of); Ryu, Jae-Ha, E-mail: ryuha@sookmyung.ac.kr [College of Pharmacy and Research Center for Cell Fate Control, Sookmyung Women’s University, 52 Hyochangwon-Gil, Yongsan-Gu, Seoul 140-742 (Korea, Republic of)

    2014-01-03

    Highlights: •Tussilagone (TSL) was purified from plant as an inhibitor of Wnt/β-catenin pathway. •TSL suppressed the β-catenin/T-cell factor transcriptional activity. •The proteasomal degradation of β-catenin was induced by TSL. •TSL suppressed the Wnt/β-catenin target genes, cyclin D1 and c-myc. •TSL inhibit the proliferation of colon cancer cells. -- Abstract: Abnormal activation of the Wnt/β-catenin signaling pathway frequently induces colon cancer progression. In the present study, we identified tussilagone (TSL), a compound isolated from the flower buds of Tussilago farfara, as an inhibitor on β-catenin dependent Wnt pathway. TSL suppressed β-catenin/T-cell factor transcriptional activity and down-regulated β-catenin level both in cytoplasm and nuclei of HEK293 reporter cells when they were stimulated by Wnt3a or activated by an inhibitor of glycogen synthase kinase-3β. Since the mRNA level was not changed by TSL, proteasomal degradation might be responsible for the decreased level of β-catenin. In SW480 and HCT116 colon cancer cell lines, TSL suppressed the β-catenin activity and also decreased the expression of cyclin D1 and c-myc, representative target genes of the Wnt/β-catenin signaling pathway, and consequently inhibited the proliferation of colon cancer cells. Taken together, TSL might be a potential chemotherapeutic agent for the prevention and treatment of human colon cancer.

  7. Cyclohexylmethyl Flavonoids Suppress Propagation of Breast Cancer Stem Cells via Downregulation of NANOG

    Directory of Open Access Journals (Sweden)

    Wen-Ying Liao

    2013-01-01

    Full Text Available Breast cancer stem cells (CSCs are highly tumorigenic and possess the capacity to self-renew. Recent studies indicated that pluripotent gene NANOG involves in regulating self-renewal of breast CSCs, and expression of NANOG is correlated with aggressiveness of poorly differentiated breast cancer. We initially confirmed that breast cancer MCF-7 cells expressed NANOG, and overexpression of NANOG enhanced the tumorigenicity of MCF-7 cells and promoted the self-renewal expansion of CD24−/lowCD44+ CSC subpopulation. In contrast, knockdown of NANOG significantly affected the growth of breast CSCs. Utilizing flow cytometry, we identified five cyclohexylmethyl flavonoids that can inhibit propagation of NANOG-positive cells in both breast cancer MCF-7 and MDA-MB231 cells. Among these flavonoids, ugonins J and K were found to be able to induce apoptosis in non-CSC populations and to reduce self-renewal growth of CD24−/lowCD44+ CSC population. Treatment with ugonin J significantly reduced the tumorigenicity of MCF-7 cells and efficiently suppressed formation of mammospheres. This suppression was possibly due to p53 activation and NANOG reduction as either addition of p53 inhibitor or overexpression of NANOG can counteract the suppressive effect of ugonin J. We therefore conclude that cyclohexylmethyl flavonoids can possibly be utilized to suppress the propagation of breast CSCs via reduction of NANOG.

  8. DNA Damage and Cell Cycle Arrest Induced by Protoporphyrin IX in Sarcoma 180 Cells

    Directory of Open Access Journals (Sweden)

    Qing Li

    2013-09-01

    Full Text Available Background: Porphyrin derivatives have been widely used in photodynamic therapy as effective sensitizers. Protoporphyrin IX (PpIX, a well-known hematoporphyrin derivative component, shows great potential to enhance light induced tumor cell damage. However, PpIX alone could also exert anti-tumor effects. The mechanisms underlying those direct effects are incompletely understood. This study thus investigated the putative mechanisms underlying the anti-tumor effects of PpIX on sarcoma 180 (S180 cells. Methods: S180 cells were treated with different concentrations of PpIX. Following the treatment, cell viability was evaluated by the 3-(4, 5- dimethylthiazol-2-yl-2, 5-diphenyltetrazoliumbromide (MTT assay; Disruption of mitochondrial membrane potential was measured by flow cytometry; The trans-location of apoptosis inducer factor (AIF from mitochondria to nucleus was visualized by confocal laser scanning microscopy; DNA damage was detected by single cell gel electrophoresis; Cell cycle distribution was analyzed by DNA content with flow cytometry; Cell cycle associated proteins were detected by western blotting. Results: PpIX (≥ 1 µg/ml significantly inhibited proliferation and reduced viability of S180 cells in a dose-dependent manner. PpIX rapidly and significantly triggered mitochondrial membrane depolarization, AIF (apoptosis inducer factor translocation from mitochondria to nucleus and DNA damage, effects partially relieved by the specific inhibitor of MPTP (mitochondrial permeability transition pore. Furthermore, S phase arrest and upregulation of the related proteins of P53 and P21 were observed following 12 and 24 h PpIX exposure. Conclusion: PpIX could inhibit tumor cell proliferation by induction of DNA damage and cell cycle arrest in the S phase.

  9. Adhesion and internalization differences of COM nanocrystals on Vero cells before and after cell damage

    Energy Technology Data Exchange (ETDEWEB)

    Gan, Qiong-Zhi; Sun, Xin-Yuan; Ouyang, Jian-Ming, E-mail: toyjm@jnu.edu.cn

    2016-02-01

    The adhesion and internalization between African green monkey kidney epithelial (Vero) cells (before and after oxidative damage by hydrogen peroxide) and calcium oxalate monohydrate (COM) nanocrystals (97 ± 35 nm) were investigated so as to discuss the molecular and cellular mechanism of kidney stone formation. Scanning electron microscope (SEM) was used to observe the Vero–COM nanocrystal adhesion; the nanocrystal-cell adhesion was evaluated by measuring the content of malonaldehyde (MDA), the activity of superoxide dismutase (SOD), the expression level of cell surface osteopontin (OPN) and the change of Zeta potential. Confocal microscopy and flow cytometry were used for the observation and quantitative analysis of crystal internalization. In the process of adhesion, the cell viability and the SOD activity declined, the MDA content, Zeta potential, and the OPN expression level increased. The adhesive capacity of injured Vero was obviously stronger than normal cells; in addition the injured cells promoted the aggregation of COM nanocrystals. The capacity of normal cells to internalize crystals was obviously stronger than that of injured cells. Cell injury increased adhesive sites on cell surface, thereby facilitating the aggregation of COM nanocrystals and their attachment, which results in enhanced risk of calcium oxalate stone formation. - Graphical abstract: The adhesion and internalization differences between Vero cells before and after oxidative damage and calcium oxalate monohydrate nanocrystals were comparatively studied. - Highlights: • Adhesion capacity of injured Vero cells was stronger than normal cells. • Internalization capacity of injured Vero cells was weaker than normal cells. • Injured cells promoted the aggregation of COM nanocrystals. • COM adhesion could aggravate cell injury in both normal and injured cells.

  10. DNA damage response in renal ischemia-reperfusion and ATP-depletion injury of renal tubular cells.

    Science.gov (United States)

    Ma, Zhengwei; Wei, Qingqing; Dong, Guie; Huo, Yuqing; Dong, Zheng

    2014-07-01

    Renal ischemia-reperfusion leads to acute kidney injury (AKI) that is characterized pathologically by tubular damage and cell death, followed by tubular repair, atrophy and interstitial fibrosis. Recent work suggested the possible presence of DNA damage response (DDR) in AKI. However, the evidence is sketchy and the role and regulation of DDR in ischemic AKI remain elusive. In this study, we demonstrated the induction of phosphorylation of ATM, H2AX, Chk2 and p53 during renal ischemia-reperfusion in mice, suggesting DDR in kidney tissues. DDR was also induced in vitro during the recovery or "reperfusion" of renal proximal tubular cells (RPTCs) after ATP depletion. DDR in RPTCs was abrogated by supplying glucose to maintain ATP via glycolysis, indicating that the DDR depends on ATP depletion. The DDR was also suppressed by the general caspase inhibitor z-VAD and the overexpression of Bcl-2, supporting a role of apoptosis-associated DNA damage in the DDR. N-acetylcysteine (NAC), an antioxidant, suppressed the phosphorylation of ATM and p53 and, to a less extent, Chk2, but NAC increased the phosphorylation and nuclear foci formation of H2AX. Interestingly, NAC increased apoptosis, which may account for the observed H2AX activation. Ku55933, an ATM inhibitor, blocked ATM phosphorylation and ameliorated the phosphorylation of Chk2 and p53, but it increased H2AX phosphorylation and nuclear foci formation. Ku55933 also increased apoptosis in RPTCs following ATP depletion. The results suggest that DDR occurs during renal ischemia-reperfusion in vivo and ATP-depletion injury in vitro. The DDR is partially induced by apoptosis and oxidative stress-related DNA damage. ATM, as a sensor in the DDR, may play a cytoprotective role against tubular cell injury and death. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Alisertib Induces Cell Cycle Arrest, Apoptosis, Autophagy and Suppresses EMT in HT29 and Caco-2 Cells

    Science.gov (United States)

    Ren, Bao-Jun; Zhou, Zhi-Wei; Zhu, Da-Jian; Ju, Yong-Le; Wu, Jin-Hao; Ouyang, Man-Zhao; Chen, Xiao-Wu; Zhou, Shu-Feng

    2015-01-01

    Colorectal cancer (CRC) is one of the most common malignancies worldwide with substantial mortality and morbidity. Alisertib (ALS) is a selective Aurora kinase A (AURKA) inhibitor with unclear effect and molecular interactome on CRC. This study aimed to evaluate the molecular interactome and anticancer effect of ALS and explore the underlying mechanisms in HT29 and Caco-2 cells. ALS markedly arrested cells in G2/M phase in both cell lines, accompanied by remarkable alterations in the expression level of key cell cycle regulators. ALS induced apoptosis in HT29 and Caco-2 cells through mitochondrial and death receptor pathways. ALS also induced autophagy in HT29 and Caco-2 cells, with the suppression of phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR), but activation of 5′ AMP-activated protein kinase (AMPK) signaling pathways. There was a differential modulating effect of ALS on p38 MAPK signaling pathway in both cell lines. Moreover, induction or inhibition of autophagy modulated basal and ALS-induced apoptosis in both cell lines. ALS potently suppressed epithelial to mesenchymal transition (EMT) in HT29 and Caco-2 cells. Collectively, it suggests that induction of cell cycle arrest, promotion of apoptosis and autophagy, and suppression of EMT involving mitochondrial, death receptor, PI3K/Akt/mTOR, p38 MAPK, and AMPK signaling pathways contribute to the cancer cell killing effect of ALS on CRC cells. PMID:26729093

  12. Alisertib Induces Cell Cycle Arrest, Apoptosis, Autophagy and Suppresses EMT in HT29 and Caco-2 Cells

    Directory of Open Access Journals (Sweden)

    Bao-Jun Ren

    2015-12-01

    Full Text Available Colorectal cancer (CRC is one of the most common malignancies worldwide with substantial mortality and morbidity. Alisertib (ALS is a selective Aurora kinase A (AURKA inhibitor with unclear effect and molecular interactome on CRC. This study aimed to evaluate the molecular interactome and anticancer effect of ALS and explore the underlying mechanisms in HT29 and Caco-2 cells. ALS markedly arrested cells in G2/M phase in both cell lines, accompanied by remarkable alterations in the expression level of key cell cycle regulators. ALS induced apoptosis in HT29 and Caco-2 cells through mitochondrial and death receptor pathways. ALS also induced autophagy in HT29 and Caco-2 cells, with the suppression of phosphoinositide 3-kinase (PI3K/protein kinase B (Akt/mammalian target of rapamycin (mTOR, but activation of 5′ AMP-activated protein kinase (AMPK signaling pathways. There was a differential modulating effect of ALS on p38 MAPK signaling pathway in both cell lines. Moreover, induction or inhibition of autophagy modulated basal and ALS-induced apoptosis in both cell lines. ALS potently suppressed epithelial to mesenchymal transition (EMT in HT29 and Caco-2 cells. Collectively, it suggests that induction of cell cycle arrest, promotion of apoptosis and autophagy, and suppression of EMT involving mitochondrial, death receptor, PI3K/Akt/mTOR, p38 MAPK, and AMPK signaling pathways contribute to the cancer cell killing effect of ALS on CRC cells.

  13. Sangivamycin induces apoptosis by suppressing Erk signaling in primary effusion lymphoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Wakao, Kazufumi [Department of Biotechnology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Kofu-shi 400-8511 (Japan); Watanabe, Tadashi [Department of Cell Biology, Kyoto Pharmaceutical University, Misasagi-Shichonocho 1, Yamashinaku, Kyoto 607-8412 (Japan); Takadama, Tadatoshi; Ui, Sadaharu [Department of Biotechnology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Kofu-shi 400-8511 (Japan); Shigemi, Zenpei; Kagawa, Hiroki [Department of Cell Biology, Kyoto Pharmaceutical University, Misasagi-Shichonocho 1, Yamashinaku, Kyoto 607-8412 (Japan); Higashi, Chizuka; Ohga, Rie; Taira, Takahiro [Department of Molecular Cell Biology, Faculty of Medicine, University of Yamanashi, Chuoh-shi 409-3898 (Japan); Fujimuro, Masahiro, E-mail: fuji2@mb.kyoto-phu.ac.jp [Department of Cell Biology, Kyoto Pharmaceutical University, Misasagi-Shichonocho 1, Yamashinaku, Kyoto 607-8412 (Japan)

    2014-02-07

    Highlights: • Sangivamycin induces the apoptosis of B cell lymphoma PEL cells. • Sangivamycin suppresses Erk signaling by inhibiting Erk phosphorylation in PEL cells. • The activation of Erk signaling is essential for PEL cell survival. • Sangivamycin induces the apoptosis of PEL cells without production of progeny virus. • Sangivamycin may serve as a novel drug for the treatment of PEL. - Abstract: Sangivamycin, a structural analog of adenosine and antibiotic exhibiting antitumor and antivirus activities, inhibits protein kinase C and the synthesis of both DNA and RNA. Primary effusion lymphoma (PEL) is an aggressive neoplasm caused by Kaposi’s sarcoma-associated herpesvirus (KSHV) in immunosuppressed patients and HIV-infected homosexual males. PEL cells are derived from post-germinal center B cells, and are infected with KSHV. Herein, we asked if sangivamycin might be useful to treat PEL. We found that sangivamycin killed PEL cells, and we explored the underlying mechanism. Sangivamycin treatment drastically decreased the viability of PEL cell lines compared to KSHV-uninfected B lymphoma cell lines. Sangivamycin induced the apoptosis of PEL cells by activating caspase-7 and -9. Further, sangivamycin suppressed the phosphorylation of Erk1/2 and Akt, thus inhibiting activation of the proteins. Inhibitors of Akt and MEK suppressed the proliferation of PEL cells compared to KSHV-uninfected cells. It is known that activation of Erk and Akt signaling inhibits apoptosis and promotes proliferation in PEL cells. Our data therefore suggest that sangivamycin induces apoptosis by inhibiting Erk and Akt signaling in such cells. We next investigated whether sangivamycin, in combination with an HSP90 inhibitor geldanamycin (GA) or valproate (valproic acid), potentiated the cytotoxic effects of the latter drugs on PEL cells. Compared to treatment with GA or valproate alone, the addition of sangivamycin enhanced cytotoxic activity. Our data thus indicate that

  14. Sangivamycin induces apoptosis by suppressing Erk signaling in primary effusion lymphoma cells

    International Nuclear Information System (INIS)

    Wakao, Kazufumi; Watanabe, Tadashi; Takadama, Tadatoshi; Ui, Sadaharu; Shigemi, Zenpei; Kagawa, Hiroki; Higashi, Chizuka; Ohga, Rie; Taira, Takahiro; Fujimuro, Masahiro

    2014-01-01

    Highlights: • Sangivamycin induces the apoptosis of B cell lymphoma PEL cells. • Sangivamycin suppresses Erk signaling by inhibiting Erk phosphorylation in PEL cells. • The activation of Erk signaling is essential for PEL cell survival. • Sangivamycin induces the apoptosis of PEL cells without production of progeny virus. • Sangivamycin may serve as a novel drug for the treatment of PEL. - Abstract: Sangivamycin, a structural analog of adenosine and antibiotic exhibiting antitumor and antivirus activities, inhibits protein kinase C and the synthesis of both DNA and RNA. Primary effusion lymphoma (PEL) is an aggressive neoplasm caused by Kaposi’s sarcoma-associated herpesvirus (KSHV) in immunosuppressed patients and HIV-infected homosexual males. PEL cells are derived from post-germinal center B cells, and are infected with KSHV. Herein, we asked if sangivamycin might be useful to treat PEL. We found that sangivamycin killed PEL cells, and we explored the underlying mechanism. Sangivamycin treatment drastically decreased the viability of PEL cell lines compared to KSHV-uninfected B lymphoma cell lines. Sangivamycin induced the apoptosis of PEL cells by activating caspase-7 and -9. Further, sangivamycin suppressed the phosphorylation of Erk1/2 and Akt, thus inhibiting activation of the proteins. Inhibitors of Akt and MEK suppressed the proliferation of PEL cells compared to KSHV-uninfected cells. It is known that activation of Erk and Akt signaling inhibits apoptosis and promotes proliferation in PEL cells. Our data therefore suggest that sangivamycin induces apoptosis by inhibiting Erk and Akt signaling in such cells. We next investigated whether sangivamycin, in combination with an HSP90 inhibitor geldanamycin (GA) or valproate (valproic acid), potentiated the cytotoxic effects of the latter drugs on PEL cells. Compared to treatment with GA or valproate alone, the addition of sangivamycin enhanced cytotoxic activity. Our data thus indicate that

  15. Oxidative Stress, Cell Death, and Other Damage to Alveolar Epithelial Cells Induced by Cigarette Smoke

    Directory of Open Access Journals (Sweden)

    Nagai A

    2003-09-01

    Full Text Available Abstract Cigarette smoking is a major risk factor in the development of various lung diseases, including pulmonary emphysema, pulmonary fibrosis, and lung cancer. The mechanisms of these diseases include alterations in alveolar epithelial cells, which are essential in the maintenance of normal alveolar architecture and function. Following cigarette smoking, alterations in alveolar epithelial cells induce an increase in epithelial permeability, a decrease in surfactant production, the inappropriate production of inflammatory cytokines and growth factors, and an increased risk of lung cancer. However, the most deleterious effect of cigarette smoke on alveolar epithelial cells is cell death, i.e., either apoptosis or necrosis depending on the magnitude of cigarette smoke exposure. Cell death induced by cigarette smoke exposure can largely be accounted for by an enhancement in oxidative stress. In fact, cigarette smoke contains and generates many reactive oxygen species that damage alveolar epithelial cells. Whether apoptosis and/or necrosis in alveolar epithelial cells is enhanced in healthy cigarette smokers is presently unclear. However, recent evidence indicates that the apoptosis of alveolar epithelial cells and alveolar endothelial cells is involved in the pathogenesis of pulmonary emphysema, an important cigarette smoke-induced lung disease characterized by the loss of alveolar structures. This review will discuss oxidative stress, cell death, and other damage to alveolar epithelial cells induced by cigarette smoke.

  16. Transplants of cells engineered to produce GABA suppress spontaneous seizures

    Czech Academy of Sciences Publication Activity Database

    Thompson, K. W.; Suchomelová, Lucie

    2004-01-01

    Roč. 45, č. 1 (2004), s. 4-12 ISSN 0013-9580 Grant - others:VA Greater Los Angeles Healthcare System Research Service(US) MREP Institutional research plan: CEZ:AV0Z5011922 Keywords : cell transplantation * epilepsy * seizures Subject RIV: FH - Neurology Impact factor: 3.329, year: 2004

  17. Suppression of vascular smooth muscle cells' proliferation and ...

    African Journals Online (AJOL)

    This study aimed to determine the effects of valsartan on the proliferation and migration of isolated rat vascular smooth muscle cells (VSMCs) and the expression of phospho-p42/44 mitogen-activated protein kinase (MAPK) promoted by angiotensin II (Ang II). VSMCs from the rat thoracic aorta were cultured by ...

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

    Science.gov (United States)

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

    2017-06-13

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

  19. Suppression of saccharin-induced mutagenicity by interferon-alpha in human RSa cells.

    Science.gov (United States)

    Suzuki, N; Suzuki, H

    1995-10-01

    Saccharin is an artificial sweetener commonly used in the formulation of foods and beverages. Sodium saccharin-induced mutagenicity is detectable in human RSa cells by estimation of cloning efficiency of ouabain-resistant mutant cells and determination of K-ras codon 12 mutation in genomic DNA, analyzed by PCR and differential dot-blot hybridization. However, in this study no phenotypic or genetic mutations were detected in RSa cells cultured with human IFN (HuIFN)-alpha before sodium saccharin treatment. The suppressive effect was lessened by transient treatment with antipain immediately after sodium saccharin treatment. Elevation of antipain-sensitive protease activity was found, furthermore, in RSa cells cultured with HuIFN-alpha and subsequently treated with sodium saccharin. Thus, antipain-sensitive protease induction in cells tested here may be involved in suppression of the mutagenicity of saccharin by HuIFN-alpha.

  20. New Insights into p53 Signaling and Cancer Cell Response to DNA Damage: Implications for Cancer Therapy

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    Razmik Mirzayans

    2012-01-01

    Full Text Available Activation of the p53 signaling pathway by DNA-damaging agents was originally proposed to result either in cell cycle checkpoint activation to promote survival or in apoptotic cell death. This model provided the impetus for numerous studies focusing on the development of p53-based cancer therapies. According to recent evidence, however, most p53 wild-type human cell types respond to ionizing radiation by undergoing stress-induced premature senescence (SIPS and not apoptosis. SIPS is a sustained growth-arrested state in which cells remain viable and secrete factors that may promote cancer growth and progression. The p21WAF1 (hereafter p21 protein has emerged as a key player in the p53 pathway. In addition to its well-studied role in cell cycle checkpoints, p21 regulates p53 and its upstream kinase (ATM, controls gene expression, suppresses apoptosis, and induces SIPS. Herein, we review these and related findings with human solid tumor-derived cell lines, report new data demonstrating dynamic behaviors of p53 and p21 in the DNA damage response, and examine the gain-of-function properties of cancer-associated p53 mutations. We point out obstacles in cancer-therapeutic strategies that are aimed at reactivating the wild-type p53 function and highlight some alternative approaches that target the apoptotic threshold in cancer cells with differing p53 status.

  1. Interferon-β Suppresses Murine Th1 Cell Function in the Absence of Antigen-Presenting Cells

    Science.gov (United States)

    Boivin, Nicolas; Baillargeon, Joanie; Doss, Prenitha Mercy Ignatius Arokia; Roy, Andrée-Pascale; Rangachari, Manu

    2015-01-01

    Interferon (IFN)-β is a front-line therapy for the treatment of the relapsing-remitting form of multiple sclerosis. However, its immunosuppressive mechanism of function remains incompletely understood. While it has been proposed that IFN-β suppresses the function of inflammatory myelin antigen-reactive T cells by promoting the release of immunomodulatory cytokines such as IL-27 from antigen-presenting cells (APCs), its direct effects on inflammatory CD4+ Th1 cells are less clear. Here, we establish that IFN-β inhibits mouse IFN-γ+ Th1 cell function in the absence of APCs. CD4+ T cells express the type I interferon receptor, and IFN-β can suppress Th1 cell proliferation under APC-free stimulation conditions. IFN-β-treated myelin antigen-specific Th1 cells are impaired in their ability to induce severe experimental autoimmune encephalomyelitis (EAE) upon transfer to lymphocyte-deficient Rag1-/- mice. Polarized Th1 cells downregulate IFN-γ and IL-2, and upregulate the negative regulatory receptor Tim-3, when treated with IFN-β in the absence of APCs. Further, IFN-β treatment of Th1 cells upregulates phosphorylation of Stat1, and downregulates phosphorylation of Stat4. Our data indicate that IFN-γ-producing Th1 cells are directly responsive to IFN-β and point to a novel mechanism of IFN-β-mediated T cell suppression that is independent of APC-derived signals. PMID:25885435

  2. Behavioral experience induces zif268 expression in mature granule cells but suppresses its expression in immature granule cells

    Science.gov (United States)

    Huckleberry, Kylie A.; Kane, Gary A.; Mathis, Rita J.; Cook, Sarah G.; Clutton, Jonathan E.; Drew, Michael R.

    2015-01-01

    Thousands of neurons are born each day in the dentate gyrus (DG), but many of these cells die before reaching maturity. Both death and survival of adult-born neurons are regulated by neuronal activity in the DG. The immediate-early gene (IEG) zif268 appears to be an important mediator of these effects, as its expression can be induced by neural activity and knockout of zif268 impairs survival of adult-born neurons (Richardson et al., 1992; Veyrac et al., 2013). Despite the apparent importance of zif268 for adult neurogenesis, its behavior-induced expression has not been fully characterized in adult-born neurons. Here we characterize behavior-evoked expression of zif268 in mature and newborn dentate granule cells (DGCs). We first quantified zif268 expression in doublecortin-positive (DCX+) immature neurons and in the general granule cell population after brief exposure to a novel environment (NE). In the general granule cell population, zif268 expression peaked 1 h after NE exposure and returned to baseline by 8 h post-exposure. However, in the DCX+ cells, zif268 expression was suppressed relative to home cage for at least 8 h post-exposure. We next asked whether suppression of zif268 in DCX+ immature cells occurs in other behavioral paradigms that recruit the hippocampus. Exposure to Morris water maze (MWM) training, an enriched environment, or a NE caused approximately equal suppression of zif268 expression in DCX+ cells and approximately equal activation of zif268 expression among the general granule cell population. The same behavioral procedures activated zif268 expression in 6-week-old BrdU-labeled adult-born neurons, indicating that zif268 suppression is specific to immature neurons. Finally, we asked whether zif268 suppression varied as a function of age within the DCX+ population, which ranges in age from 0 to approximately 4 weeks. NE exposure had no significant effect on zif268 expression in 2- or 4-week-old BrdU-labeled neurons, but it significantly

  3. The RhoGEF TEM4 Regulates Endothelial Cell Migration by Suppressing Actomyosin Contractility.

    Directory of Open Access Journals (Sweden)

    Natalia Mitin

    Full Text Available Persistent cellular migration requires efficient protrusion of the front of the cell, the leading edge where the actin cytoskeleton and cell-substrate adhesions undergo constant rearrangement. Rho family GTPases are essential regulators of the actin cytoskeleton and cell adhesion dynamics. Here, we examined the role of the RhoGEF TEM4, an activator of Rho family GTPases, in regulating cellular migration of endothelial cells. We found that TEM4 promotes the persistence of cellular migration by regulating the architecture of actin stress fibers and cell-substrate adhesions in protruding membranes. Furthermore, we determined that TEM4 regulates cellular migration by signaling to RhoC as suppression of RhoC expression recapitulated the loss-of-TEM4 phenotypes, and RhoC activation was impaired in TEM4-depleted cells. Finally, we showed that TEM4 and RhoC antagonize myosin II-dependent cellular contractility and the suppression of myosin II activity rescued the persistence of cellular migration of TEM4-depleted cells. Our data implicate TEM4 as an essential regulator of the actin cytoskeleton that ensures proper membrane protrusion at the leading edge of migrating cells and efficient cellular migration via suppression of actomyosin contractility.

  4. Selective Mitochondrial Uptake of MKT-077 Can Suppress Medullary Thyroid Carcinoma Cell Survival and

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    Dmytro Starenki

    2015-12-01

    Full Text Available BackgroundMedullary thyroid carcinoma (MTC is a neuroendocrine tumor mainly caused by mutations in the rearranged during transfection (RET proto-oncogene. Not all patients with progressive MTC respond to current therapy inhibiting RET, demanding additional therapeutic strategies. We recently demonstrated that disrupting mitochondrial metabolism using a mitochondria-targeted agent or by depleting a mitochondrial chaperone effectively suppressed human MTC cells in culture and in mouse xenografts by inducing apoptosis and RET downregulation. These observations led us to hypothesize that mitochondria are potential therapeutic targets for MTC. This study further tests this hypothesis using1-ethyl-2-[[3-ethyl-5-(3-methylbenzothiazolin-2-yliden]-4-oxothiazolidin-2-ylidenemethyl] pyridinium chloride (MKT-077, a water-soluble rhodocyanine dye analogue, which can selectively accumulate in mitochondria.MethodsThe effects of MKT-077 on cell proliferation, survival, expression of RET and tumor protein 53 (TP53, and mitochondrial activity were determined in the human MTC lines in culture and in mouse xenografts.ResultsMKT-077 induced cell cycle arrest in TT and MZ-CRC-1. Intriguingly, MKT-077 also induced RET downregulation and strong cell death responses in TT cells, but not in MZ-CRC-1 cells. This discrepancy was mainly due to the difference between the capacities of these cell lines to retain MKT-077 in mitochondria. The cytotoxicity of MKT-077 in TT cells was mainly attributed to oxidative stress while being independent of TP53. MKT-077 also effectively suppressed tumor growth of TT xenografts.ConclusionMKT-077 can suppress cell survival of certain MTC subtypes by accumulating in mitochondria and interfering with mitochondrial activity although it can also suppress cell proliferation via other mechanisms. These results consistently support the hypothesis that mitochondrial targeting has therapeutic potential for MTC.

  5. Mechanism of suppressive effect of low dose radiation on cancer cell dissemination in mice

    International Nuclear Information System (INIS)

    Fu Haiqing; Li Xiuyi; Chen Yubing; Zhang Yingchun; Liu Shuzheng

    1997-01-01

    Influence of low dose radiation on immunity in C57 BL/6 mice injected with cancer cells was studied. In mice given 75 mGy WBI 24 h before injection of Lewis lung carcinoma cells or B 16 melanoma cells, the percentage of S-phase thymocytes and CD 3+ thymocytes, the splenic NK cell activity, IL-2 secretion and γIFN secretion were found to be potentiated 2∼8 day after irradiation in comparison with the sham-irradiation mice. The results suggest that low dose radiation might suppress cancer cell dissemination via the enhancement of immune reactivity

  6. Alcoholic beverages and gastric epithelial cell viability: effect on oxidative stress-induced damage.

    Science.gov (United States)

    Loguercio, C; Tuccillo, C; Federico, A; Fogliano, V; Del Vecchio Blanco, C; Romano, M

    2009-12-01

    Alcohol is known to cause damage to the gastric epithelium independently of gastric acid secretion. Different alcoholic beverages exert different damaging effects in the stomach. However, this has not been systematically evaluated. Moreover, it is not known whether the non-alcoholic components of alcoholic beverages also play a role in the pathogenesis of gastric epithelial cell damage. Therefore, this study was designed to evaluate whether different alcoholic beverages, at a similar ethanol concentration, exerted different damaging effect in gastric epithelial cells in vitro. Moreover, we evaluated whether pre-treatment of gastric epithelial cells with alcoholic beverages prevented oxidative stress-induced damage to gastric cells. Cell damage was assessed, in MKN-28 gastric epithelial cells, by MTT assay. Oxidative stress was induced by incubating cells with xanthine and xanthine oxidase. Gastric cell viability was assessed following 30, 60, and 120 minutes incubation with ethanol 17.5-125 mg/ml(-1) or different alcoholic beverages (i.e., beer, white wine, red wine, spirits) at comparable ethanol concentration. Finally, we assessed whether pre-incubation with red wine (with or without ethanol) prevented oxidative stress-induced cell damage. Red wine caused less damage to gastric epithelial cells in vitro compared with other alcoholic beverages at comparable ethanol concentration. Pre-treatment with red wine, but not with dealcoholate red wine, significantly and time-dependently prevented oxidative stress-induced cell damage. 1) red wine is less harmful to gastric epithelial cells than other alcoholic beverages; 2) this seems related to the non-alcoholic components of red wine, because other alcoholic beverages with comparable ethanol concentration exerted more damage than red wine; 3) red wine prevents oxidative stress-induced cell damage and this seems to be related to its ethanol content.

  7. IL-1β directly suppress ghrelin mRNA expression in ghrelin-producing cells.

    Science.gov (United States)

    Bando, Mika; Iwakura, Hiroshi; Ueda, Yoko; Ariyasu, Hiroyuki; Inaba, Hidefumi; Furukawa, Yasushi; Furuta, Hiroto; Nishi, Masahiro; Akamizu, Takashi

    2017-05-15

    In animal models, ghrelin production is suppressed by LPS administration. To elucidate the detailed molecular mechanisms involved in the phenomenon, we investigated the effects of LPS and LPS-inducible cytokines, including TNF-α, IL-1β, and IL-6, on the expression of ghrelin in the ghrelin-producing cell line MGN3-1. These cells expressed IL-1R, and IL-1β significantly suppressed ghrelin mRNA levels. The suppressive effects of IL-1β were attenuated by knockdown of IKKβ, suggesting the involvement of the NF-κB pathway. These results suggested that IL-1β is a major regulator of ghrelin expression during inflammatory processes. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Effects of Radix Adenophorae and Cyclosporine A on an OVA-Induced Murine Model of Asthma by Suppressing to T Cells Activity, Eosinophilia, and Bronchial Hyperresponsiveness

    Directory of Open Access Journals (Sweden)

    Seong-Soo Roh

    2008-01-01

    Full Text Available The present study is performed to investigate the inhibitory effects of Radix Adenophorae extract (RAE on ovalbumin-induced asthma murine model. To study the anti-inflammatory and antiasthmatic effects of RAE, we examined the development of pulmonary eosinophilic inflammation and inhibitory effects of T cells in murine by RAE and cyclosporine A (CsA. We examined determination of airway hyperresponsiveness, flow cytometric analysis (FACS, enzyme-linked immunosorbent assay (ELISA, quantitative real time (PCR, hematoxylin-eosin staining, and Masson trichrome staining in lung tissue, lung weight, total cells, and eosinophil numbers in lung tissue. We demonstrated how RAE suppressed development on inflammation and decreased airway damage.

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

    Directory of Open Access Journals (Sweden)

    Ana Belén Herrero

    2017-05-01

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

  10. Knockdown of asparagine synthetase by RNAi suppresses cell growth in human melanoma cells and epidermoid carcinoma cells.

    Science.gov (United States)

    Li, Hui; Zhou, Fusheng; Du, Wenhui; Dou, Jinfa; Xu, Yu; Gao, Wanwan; Chen, Gang; Zuo, Xianbo; Sun, Liangdan; Zhang, Xuejun; Yang, Sen

    2016-05-01

    Melanoma, the most aggressive form of skin cancer, causes more than 40,000 deaths each year worldwide. And epidermoid carcinoma is another major form of skin cancer, which could be studied together with melanoma in several aspects. Asparagine synthetase (ASNS) gene encodes an enzyme that catalyzes the glutamine- and ATP-dependent conversion of aspartic acid to asparagine, and its expression is associated with the chemotherapy resistance and prognosis in several human cancers. The present study aims to explore the potential role of ASNS in melanoma cells A375 and human epidermoid carcinoma cell line A431. We applied a lentivirus-mediated RNA interference (RNAi) system to study its function in cell growth of both cells. The results revealed that inhibition of ASNS expression by RNAi significantly suppressed the growth of melanoma cells and epidermoid carcinoma cells, and induced a G0/G1 cell cycle arrest in melanoma cells. Knockdown of ASNS in A375 cells remarkably downregulated the expression levels of CDK4, CDK6, and Cyclin D1, and upregulated the expression of p21. Therefore, our study provides evidence that ASNS may represent a potential therapeutic target for the treatment of melanoma. © 2015 International Union of Biochemistry and Molecular Biology, Inc.

  11. Nanoformulation of curcumin protects HUVEC endothelial cells against ionizing radiation and suppresses their adhesion to monocytes: potential in prevention of radiation-induced atherosclerosis.

    Science.gov (United States)

    Soltani, Behrooz; Bodaghabadi, Narges; Mahpour, Gita; Ghaemi, Nasser; Sadeghizadeh, Majid

    2016-12-01

    To investigated the potential of a novel dendrosomal nanoformulation of curcumin (DNC) in blocking radiation-induced changes in irradiated human umbilical vein endothelial cells (HUVECs), and their adhesion to human THP-1 monocytoid cells. Co 60 gamma rays reduced viability, raised the expression of adhesion molecules, ICAM-1, VCAM-1 and E-selectin (mRNA and protein), augmented the adhesion of THP-1 cells to HUVECs, activated NF-κB binding, increased the release of pro-inflammatory cytokines (IL-6, IL-8 and MCP-1) and induced oxidative damage (reduced glutathione declined, while 8-OHdG and TBARS increased). 5 µM DNC significantly inhibited these radiation-induced changes, activated the Nrf-2 pathway, and effectively suppressed THP-1 adhesion to HUVECs, implicating p38 MAPK signaling. DNC treatment is a potential preventive method against inflammation and vascular damage from ionizing radiation.

  12. Abatacept (CTLA-4Ig) treatment reduces T cell apoptosis and regulatory T cell suppression in patients with rheumatoid arthritis.

    Science.gov (United States)

    Bonelli, Michael; Göschl, Lisa; Blüml, Stephan; Karonitsch, Thomas; Hirahara, Kiyoshi; Ferner, Elisabeth; Steiner, Carl-Walter; Steiner, Günter; Smolen, Josef S; Scheinecker, Clemens

    2016-04-01

    Abatacept (CTLA-4Ig) blocks CD28-mediated T cell activation by binding to the costimulatory B7 ligands CD80/CD86 on antigen presenting cells. Costimulatory molecules, however, can also be expressed on T cells upon activation. Therefore, the aim of our study was to investigate direct effects of CTLA-4Ig on distinct T cell subsets in RA patients. Phenotypic and functional analyses of CD4(+) T cells, including CD4(+) FoxP3(+) CD25(+) regulatory T cells (Treg), from RA patients were performed before and during CTLA-4Ig therapy. In addition T cells from healthy volunteers were analysed on in vitro culture with CTLA-4Ig or anti-CD80 and anti-CD86 antibodies. Apoptotic DNA fragmentation in CD4(+) and CD4(+) FoxP3(+) T cells was measured by TUNEL staining. We observed an increase in T cells, including Treg cells, after initiation of CTLA-4Ig therapy, which was linked to a downregulation of activation-associated marker molecules and CD95 on CD4(+) T cells and Treg cells. CTLA-4Ig decreased CD95-mediated cell death in vitro in a dose-dependent manner. Functional analysis of isolated Treg cells from RA patients further revealed a diminished suppression of responder T cell proliferation. This was found to be due to CTLA-4Ig-mediated blocking of CD80 and CD86 on responder T cells that led to a diminished susceptibility for Treg cell suppression. CTLA-4Ig therapy in RA patients exerts effects beyond the suppression of T cell activation, which has to be taken into account as an additional mechanism of CTLA-4Ig treatment. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. T cells suppress memory-dependent rapid mucous cell metaplasia in mouse airways

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    Hitendra S. Chand

    2016-10-01

    Full Text Available Abstract Background Airway epithelial cells (AECs are crucial for mucosal and adaptive immunity but whether these cells respond in a memory-dependent manner is poorly studied. Previously, we have reported that LPS intratracheal instillation in rodents causes extensive neutrophilic inflammation and airway epithelial cell hyperplasia accompanied by mucous cell metaplasia (MCM. And the resolution process required a period of 40 d for the inflammation to subside and the lung epithelia to resemble the non-exposed condition. Therefore, the present study investigated the memory-dependent response of airway epithelial cells to a secondary LPS challenge after the initial inflammation was resolved. Methods Airway epithelial and mucous cells were assessed in response to a secondary LPS challenge in F344/N rats, and in C57BL/6 wild-type (Foxn1WT and T cell-deficient athymic (Foxn1nu mice that were instilled with LPS or saline 40 d earlier. Epithelial expression of TLR4, EGFR, and phosphorylated-ERK1/2 (pERK were also analyzed. Results LPS-pretreated F344/N rats responded with elevated numbers of AECs after saline challenge and with 3-4-fold increased MCM following the LPS challenge in LPS- compared with saline-pretreated rats. LPS-pretreated rats showed 5-fold higher number of AECs expressing TLR4 apically than saline-pretreated rats. Also, the expression of EGFR was increased in LPS-pretreated rats along with the number of AECs with active or nuclear pERK, and the levels were further increased upon LPS challenge. LPS-pretreated Foxn1nu compared with Foxn1WT mice showed increased MCM and elevated levels of TLR4, EGFR, and nuclear pERK at 40 d after LPS instillation. LPS challenge further augmented MCM rapidly in Foxn1nu compared with Foxn1WT mice. Conclusion Together, these data suggest that AECs preserve an ‘innate memory’ that drives a rapid mucous phenotype via spatiotemporal regulation of TLR4 and EGFR. Further, T cells may suppress the sustained

  14. Phenotypically non-suppressive cells predominate among FoxP3-positive cells in oral lichen planus.

    Science.gov (United States)

    Schreurs, Olav; Karatsaidis, Andreas; Schenck, Karl

    2016-11-01

    Oral lichen planus (OLP) is a common T-cell-dominated oral chronic inflammatory disease occurring in periods of remission, quiescence, activity with pronounced inflammation, and acute ulceration. Cell infiltrates in OLP contain varying numbers of CD4 + T cells expressing the transcription factor FoxP3. FoxP3 + CD4 + T cells are, however, a heterogeneous cell population containing suppressive and non-suppressive cells, and their distribution in infiltrates from OLP is unknown. Biopsies were taken from normal oral mucosa (n = 8) and OLP lesions (n = 19), and a set of in situ methods for the determination of the functional phenotype of FoxP3 + CD4 + T cells was applied. Numbers of FoxP3 + CD4 + T cells were highest in the atrophic form of the disease, yet low in the ulcerative form. The main FoxP3 + CD4 + T-cell population observed was FoxP3 + CD45RA - CD25 + CD45RO + and CD15s - , a phenotype delineating a non-suppressive subset. Numbers of cells with an actively suppressing phenotype (FoxP3 + CD45RA - CD25 + CD45RO + and CD15s + ) were, however, about twice as high in reticular lesions as compared with the atrophic form. Many FoxP3 + CD4 + T cells expressed T-bet, the hallmark transcription factor for IFN-γ-producing T cells, indicating that they may enhance immune and inflammatory responses rather than suppress them. The absence of actively suppressing FoxP3 + CD4 + T cells may in part explain why OLP is a remarkably persisting condition, in spite of the presence of substantially high numbers of FoxP3 + CD4 + T cells. The findings emphasize that it is crucial to examine not only numbers but also functional phenotype of FoxP3 + CD4 + T cells in human tissues. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. ATP-sensitive potassium channel: a novel target for protection against UV-induced human skin cell damage.

    Science.gov (United States)

    Cao, Cong; Healey, Sarah; Amaral, Ashley; Lee-Couture, Avery; Wan, Shu; Kouttab, Nicola; Chu, Wenming; Wan, Yinsheng

    2007-07-01

    Ultraviolet radiation (UV) induces cell damages leading to skin photoaging and skin cancer. ATP-sensitive potassium (K(ATP)) channel openers (KCOs) have been shown to exert significant myocardial preservation and neuroprotection in vitro and in vivo, and yet the potential role of those KCOs in protection against UV-induced skin cell damage is unknown. We investigated the effects of pinacidil and diazoxide, two classical KCOs, on UV-induced cell death using cultured human keratinocytes (HaCat cells). Here, we demonstrated for the first time that Kir 6.1, Kir 6.2 and SUR2 subunits of K(ATP) channels are functionally expressed in HaCaT cells and both non-selective K(ATP) channel opener pinacidil and mitoK(ATP) (mitochondrial K(ATP)) channel opener diazoxide attenuated UV-induced keratinocytes cell death. The protective effects were abolished by both non-selective K(ATP) channel blocker glibenclamide and selective mitoK(ATP) channel blocker 5-hydroxydecanoate (5-HD). Also, activation of K(ATP) channel with pinacidil or diazoxide resulted in suppressive effects on UV-induced MAPK activation and reactive oxygen species (ROS) production. Unexpectedly, we found that the level of intracellular ROS was slightly elevated in HaCaT cells when treated with pinacidil or diazoxide alone. Furthermore, UV-induced mitochondrial membrane potential loss, cytochrome c release and ultimately apoptotic cell death were also inhibited by preconditioning with pinacidil and diazoxide, and their effects were reversed by glibenclamide and 5-HD. Taken together, we contend that mitoK(ATP) is likely to contribute the protection against UV-induced keratinocytes cell damage. Our findings suggest that K(ATP) openers such as pinacidil and diazoxide may be utilized to prevent from UV-induced skin aging.

  16. Erianin inhibits the proliferation of T47D cells by inhibiting cell cycles, inducing apoptosis and suppressing migration.

    Science.gov (United States)

    Sun, Jing; Fu, Xueqi; Wang, Yongsen; Liu, Ye; Zhang, Yu; Hao, Tian; Hu, Xin

    2016-01-01

    Erianin is a natural product extracted from Dendrobiumchrysotoxum. To investigate the antitumor activity of Erianin in estrogen receptor (ER) positive breast cancer, we treated T47D cells with Erianin and evaluated the effects of Erianin treatment on multiple cancer-associated pathways. Erianin inhibited the proliferation of T47D cells effectively. Erianin induced apoptosis in T47D cells through reducing Bcl-2 expression and activating caspase signaling. Furthermore, it also suppressed the expression of CDKs and caused cell cycle arrest. In addition, Erianin treatment suppressed the migration of T47D cells, most likely through regulating the homeostatic expression of MPP and TIMP. Meanwhile, Erianin did not affect the proliferation of normal breast epithelial cell line MCF10A. Together, these results demonstrated that Erianin might have the potential to be an effective drug to treat the ER positive breast cancer.

  17. Suppression of calpain expression by NSAIDs is associated with inhibition of cell migration in rat duodenum.

    Science.gov (United States)

    Silver, Kristopher; Littlejohn, A; Thomas, Laurel; Bawa, Bhupinder; Lillich, James D

    2017-05-15

    Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used for the alleviation of pain and inflammation, but these drugs are also associated with a suite of negative side effects. Gastrointestinal (GI) toxicity is particularly concerning since it affects an estimated 70% of individuals taking NSAIDs routinely, and evidence suggests the majority of toxicity is occurring in the small intestine. Traditionally, NSAID-induced GI toxicity has been associated with indiscriminate inhibition of cyclooxygenase isoforms, but other mechanisms, including inhibition of cell migration, intestinal restitution, and wound healing, are likely to contribute to toxicity. Previous efforts demonstrated that treatment of cultured intestinal epithelial cells (IEC) with NSAIDs inhibits expression and activity of calpain proteases, but the effects of specific inhibition of calpain expression in vitro or the effects of NSAIDs on intestinal cell migration in vivo remain to be determined. Accordingly, we examined the effect of suppression of calpain protease expression with siRNA on cell migration in cultured IECs and evaluated the effects of NSAID treatment on epithelial cell migration and calpain protease expression in rat duodenum. Our results show that calpain siRNA inhibits protease expression and slows migration in cultured IECs. Additionally, NSAID treatment of rats slowed migration up the villus axis and suppressed calpain expression in duodenal epithelial cells. Our results are supportive of the hypothesis that suppression of calpain expression leading to slowing of cell migration is a potential mechanism through which NSAIDs cause GI toxicity. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. FRK inhibits breast cancer cell migration and invasion by suppressing epithelial-mesenchymal transition.

    Science.gov (United States)

    Ogunbolude, Yetunde; Dai, Chenlu; Bagu, Edward T; Goel, Raghuveera Kumar; Miah, Sayem; MacAusland-Berg, Joshua; Ng, Chi Ying; Chibbar, Rajni; Napper, Scott; Raptis, Leda; Vizeacoumar, Frederick; Vizeacoumar, Franco; Bonham, Keith; Lukong, Kiven Erique

    2017-12-22

    The human fyn-related kinase (FRK) is a non-receptor tyrosine kinase known to have tumor suppressor activity in breast cancer cells. However, its mechanism of action has not been fully characterized. We generated FRK-stable MDA-MB-231 breast cancer cell lines and analyzed the effect on cell proliferation, migration, and invasiveness. We also used kinome analysis to identify potential FRK-regulated signaling pathways. We employed both immunoblotting and RT-PCR to identify/validate FRK-regulated targets (proteins and genes) in these cells. Finally, we interrogated the TCGA and GENT gene expression databases to determine the correlation between the expression of FRK and epithelial/mesenchymal markers. We observed that FRK overexpression suppressed cell proliferation, migration, and invasiveness, inhibited various JAK/STAT, MAPK and Akt signaling pathways, and suppressed the expression of some STAT3 target genes. Also, FRK overexpression increased the expression of epithelial markers including E-cadherin mRNA and down-regulated the transcript levels of vimentin, fibronectin, and slug. Finally, we observed an inverse correlation between FRK expression and mesenchymal markers in a large cohort of breast cancer cells. Our data, therefore, suggests that FRK represses cell proliferation, migration and invasiveness by suppressing epithelial to mesenchymal transition.

  19. Tankyrase inhibitors suppress hepatocellular carcinoma cell growth via modulating the Hippo cascade.

    Directory of Open Access Journals (Sweden)

    Jiaoyuan Jia

    Full Text Available Previous data indicate that Tankyrase inhibitors exert anti-growth functions in many cancer cell lines due to their ability to inactivate the YAP protooncogene. In the present manuscript, we investigated the effect of Tankyrase inhibitors on the growth of hepatocellular carcinoma (HCC cell lines and the molecular mechanisms involved. For this purpose, we performed cell proliferation assay by colony-forming ability in seven human HCC cells subjected to XAV-939 and G007-LK Tankyrase inhibitors. Noticeably, the two Tankyrase inhibitors suppressed the HCC cell growth in a dose-dependent manner. Furthermore, we found that Tankyrase inhibitors synergized with MEK and AKT inhibitors to suppress HCC cell proliferation. At the molecular level, Tankyrase inhibitors significantly decreased YAP protein levels, reduced the expression of YAP target genes, and inhibited YAP/TEAD luciferase reporter activity. In addition, Tankyrase inhibitors administration was accompanied by upregulation of Angiomotin-like 1 (AMOTL1 and Angiomotin-like 2 (AMOTL2 proteins, two major negative regulators of YAP. Altogether, the present data indicate that XAV-939 and G007-LK Tankyrase inhibitors could suppress proliferation of hepatocellular carcinoma cells and downregulate YAP/TAZ by stabilizing AMOTL1 and AMOTL2 proteins, thus representing new potential anticancer drugs against hepatocellular carcinoma.

  20. Melatonin suppresses activation of hepatic stellate cells through ROR alpha-mediated inhibition of 5-lipoxygenase

    NARCIS (Netherlands)

    Shajari, Shiva; Laliena, Almudena; Heegsma, Janette; Jesus Tunon, Maria; Moshage, Han; Faber, Klaas Nico

    2015-01-01

    Liver fibrosis is scar tissue resulting from an uncontrolled wound-healing process in response to chronic liver injury. Liver damage generates an inflammatory reaction that activates hepatic stellate cells (HSC) that transdifferentiate from quiescent cells that control retinol metabolism to

  1. Kaempferol induces DNA damage and inhibits DNA repair associated protein expressions in human promyelocytic leukemia HL-60 cells.

    Science.gov (United States)

    Wu, Lung-Yuan; Lu, Hsu-Feng; Chou, Yu-Cheng; Shih, Yung-Luen; Bau, Da-Tian; Chen, Jaw-Chyun; Hsu, Shu-Chun; Chung, Jing-Gung

    2015-01-01

    Numerous evidences have shown that plant flavonoids (naturally occurring substances) have been reported to have chemopreventive activities and protect against experimental carcinogenesis. Kaempferol, one of the flavonoids, is widely distributed in fruits and vegetables, and may have cancer chemopreventive properties. However, the precise underlying mechanism regarding induced DNA damage and suppressed DNA repair system are poorly understood. In this study, we investigated whether kaempferol induced DNA damage and affected DNA repair associated protein expression in human leukemia HL-60 cells in vitro. Percentages of viable cells were measured via a flow cytometry assay. DNA damage was examined by Comet assay and DAPI staining. DNA fragmentation (ladder) was examined by DNA gel electrophoresis. The changes of protein levels associated with DNA repair were examined by Western blotting. Results showed that kaempferol dose-dependently decreased the viable cells. Comet assay indicated that kaempferol induced DNA damage (Comet tail) in a dose-dependent manner and DAPI staining also showed increased doses of kaempferol which led to increased DNA condensation, these effects are all of dose-dependent manners. Western blotting indicated that kaempferol-decreased protein expression associated with DNA repair system, such as phosphate-ataxia-telangiectasia mutated (p-ATM), phosphate-ataxia-telangiectasia and Rad3-related (p-ATR), 14-3-3 proteins sigma (14-3-3σ), DNA-dependent serine/threonine protein kinase (DNA-PK), O(6)-methylguanine-DNA methyltransferase (MGMT), p53 and MDC1 protein expressions, but increased the protein expression of p-p53 and p-H2AX. Protein translocation was examined by confocal laser microscopy, and we found that kaempferol increased the levels of p-H2AX and p-p53 in HL-60 cells. Taken together, in the present study, we found that kaempferol induced DNA damage and suppressed DNA repair and inhibited DNA repair associated protein expression in HL-60

  2. Human Liver Stem Cells Suppress T-Cell Proliferation, NK Activity, and Dendritic Cell Differentiation

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    Stefania Bruno

    2016-01-01

    Full Text Available Human liver stem cells (HLSCs are a mesenchymal stromal cell-like population resident in the adult liver. Preclinical studies indicate that HLSCs could be a good candidate for cell therapy. The aim of the present study was to evaluate the immunogenicity and the immunomodulatory properties of HLSCs on T-lymphocytes, natural killer cells (NKs, and dendritic cells (DCs in allogeneic experimental settings. We found that HLSCs inhibited T-cell proliferation by a mechanism independent of cell contact and dependent on the release of prostaglandin E2 (PGE2 and on indoleamine 2,3-dioxygenase activity. When compared with mesenchymal stromal cells (MSCs, HLSCs were more efficient in inhibiting T-cell proliferation. At variance with MSCs, HLSCs did not elicit NK degranulation. Moreover, HLSCs inhibited NK degranulation against K562, a NK-sensitive target, by a mechanism dependent on HLA-G release. When tested on DC generation from monocytes, HLSCs were found to impair DC differentiation and DCs ability to induce T-cell proliferation through PGE2. This study shows that HLSCs have immunomodulatory properties similar to MSCs, but, at variance with MSCs, they do not elicit a NK response.

  3. Multi-walled carbon nanotubes suppress potassium channel activities in PC12 cells

    Science.gov (United States)

    Xu, Haifei; Bai, Juan; Meng, Jie; Hao, Wei; Xu, Haiyan; Cao, Ji-Min

    2009-07-01

    The advancement in nanotechnology has produced technological and conceptual breakthroughs but the effects nanomaterials have on organisms at the cellular level are poorly understood. Here we report that carboxyl-terminated multi-walled carbon nanotubes (MWCNTs) act as antagonists of three types of potassium channels as assessed by whole-cell patch clamp electrophysiology on undifferentiated pheochromocytoma (PC12) cells. Our results showed that carboxyl-terminated MWCNTs suppress the current densities of Ito, IK and IK1 in a time-dependent and irreversible manner. The suppressions were most distinct 24 h after incubation with MWCNTs. However, MWCNTs did not significantly change the expression levels of reactive oxygen species (ROS) or intracellular free calcium and also did not alter the mitochondrial membrane potential (ΔΨm) in PC12 cells. These results suggest that oxidative stress was not involved in the MWCNTs suppression of Ito, IK and IK1 current densities. Nonetheless, the suppression of potassium currents by MWCNTs will impact on electrical signaling of excitable cells such as neurons and muscles.

  4. Suppression of CCR impacts metabolite profile and cell wall composition in Pinus radiata tracheary elements.

    Science.gov (United States)

    Wagner, Armin; Tobimatsu, Yuki; Goeminne, Geert; Phillips, Lorelle; Flint, Heather; Steward, Diane; Torr, Kirk; Donaldson, Lloyd; Boerjan, Wout; Ralph, John

    2013-01-01

    Suppression of the lignin-related gene cinnamoyl-CoA reductase (CCR) in the Pinus radiata tracheary element (TE) system impacted both the metabolite profile and the cell wall matrix in CCR-RNAi lines. UPLC-MS/MS-based metabolite profiling identified elevated levels of p-coumaroyl hexose, caffeic acid hexoside and ferulic acid hexoside in CCR-RNAi lines, indicating a redirection of metabolite flow within phenylpropanoid metabolism. Dilignols derived from coniferyl alcohol such as G(8-5)G, G(8-O-4)G and isodihydrodehydrodiconiferyl alcohol (IDDDC) were substantially depleted, providing evidence for CCR's involvement in coniferyl alcohol biosynthesis. Severe CCR suppression almost halved lignin content in TEs based on a depletion of both H-type and G-type lignin, providing evidence for CCR's involvement in the biosynthesis of both lignin types. 2D-NMR studies revealed minor changes in the H:G-ratio and consequently a largely unchanged interunit linkage distribution in the lignin polymer. However, unusual cell wall components including ferulate and unsaturated fatty acids were identified in TEs by thioacidolysis, pyrolysis-GC/MS and/or 2D-NMR in CCR-RNAi lines, providing new insights into the consequences of CCR suppression in pine. Interestingly, CCR suppression substantially promoted pyrolytic breakdown of cell wall polysaccharides, a phenotype most likely caused by the incorporation of acidic compounds into the cell wall matrix in CCR-RNAi lines.

  5. Histamine suppresses regulatory T cells mediated by TGF-β in murine chronic allergic contact dermatitis.

    Science.gov (United States)

    Tamaka, Kyoko; Seike, Masahiro; Hagiwara, Tamio; Sato, Atsushi; Ohtsu, Hiroshi

    2015-04-01

    Regulatory T cells (Tregs) suppress effector T cells and ameliorate contact hypersensitivity (CH); however, the role of Tregs in chronic allergic contact dermatitis (CACD) has not been assessed. Repeated elicitation of CH has been used to produce CACD models in mice. We previously showed that the presence of histamine facilitates the creation of eczematous lesions in this model using histidine decarboxylase (HDC) (-/-) mice. Therefore, the effects of histamine on Tregs in the CACD model were investigated in this study. CACD was developed by repeated epicutaneous application of 2, 4, 6-trinitro-1-chlorobenzene (TNCB) on HDC (+/+) and HDC (-/-) murine skin to assess the effects of histamine in CACD. Histamine aggravated CACD in the murine model and suppressed the number of Tregs in the skin. Histamine also suppressed the level of TGF-β1 in this model. Recombinant TGF-β1 or anti-TGF-β1 antibody was injected into the dorsal dermis of HDC (+/+) mice daily just before TNCB challenge to determine the effects of histamine-regulated TGF-β on the Treg population in CACD. Recombinant TGF-β1 injection promoted the infiltration of Tregs in the skin and the production of IL-10; however, anti-TGF-β1 antibody injection suppressed the number of Tregs in the skin and the production of IL-10. Histamine suppresses the number of Tregs in CACD, and this effect is mediated by TGF-β. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. Curcumin activates autophagy and attenuates oxidative damage in EA.hy926 cells via the Akt/mTOR pathway.

    Science.gov (United States)

    Guo, Shouyu; Long, Mingzhi; Li, Xiuzhen; Zhu, Shushu; Zhang, Min; Yang, Zhijian

    2016-03-01

    Curcumin, which is the effective component of turmeric (Curcuma longa), has previously been shown to exert potent antioxidant, antitumor and anti‑inflammatory activities in vitro and in vivo. However, the mechanism underlying the protective effects of curcumin against oxidative damage in endothelial cells remains unclear. The present study aimed to examine the effects of curcumin on hydrogen peroxide (H2O2)‑induced apoptosis and autophagy in EA.hy926 cells, and to determine the underlying molecular mechanism. Cultured EA.hy926 cells were treated with curcumin (5‑20 µmol/l) 4 h prior to and for 4 h during exposure to H2O2 (200 µmol/l). Oxidative stress resulted in a significant increase in the rate of cell apoptosis, which was accompanied by an increase in the expression levels of caspase‑3 and B‑cell lymphoma 2 (Bcl‑2)‑associated X protein (Bax), and a decrease in the expression levels of Bcl‑2. Treatment with curcumin (5 or 20 µmol/l) significantly inhibited apoptosis, and reversed the alterations in caspase‑3, Bcl‑2 and Bax expression. Furthermore, curcumin induced autophagy and microtubule‑associated protein 1A/1B‑light chain 3‑Ⅱ expression, and suppressed the phosphorylation of Akt and mammalian target of rapamycin (mTOR). These results indicated that curcumin may protect cells against oxidative stress‑induced damage through inhibiting apoptosis and inducing autophagy via the Akt/mTOR pathway.

  7. Molecular mechanism of radioadaptive response: A cross-adaptive response for enhanced repair of DNA damage in adapted cells

    International Nuclear Information System (INIS)

    Takaji Ikushima

    1997-01-01

    The radioadaptive response (RAR) has been attributed to the induction of a repair mechanism by low doses of ionizing radiation, but the molecular nature of the mechanism is not yet elucidated. We have characterized RAR in a series of experiments in cultured Chinese hamster V79 cells. A 4-h interval is required for the full expression of RAR, which decays with the progression of cell proliferation. Treatments with inhibitors of poly(ADP-ribose) polymerase, protein- or RNA synthesis, and protein kinase C suppress the RAR expression. The RAR cross-reacts on clastogenic lesions induced by other physical and chemical DNA-damaging agents. The presence of newly synthesised proteins has been detected during the expression period. Experiments performed using single-cell gel electrophoresis provided more direct evidence for a faster and enhaced DNA repair rate in adapted cells. Here, using single-cell gel electrophoresis, a cross-adaptive response has been demonstrated for enhanced repair of DNA damage induced by neocarzinostatin in radio-adapted cells. (author)

  8. Quercetin Suppresses Twist to Induce Apoptosis in MCF-7 Breast Cancer Cells.

    Directory of Open Access Journals (Sweden)

    Santhalakshmi Ranganathan

    Full Text Available Quercetin is a dietary flavonoid which exerts anti-oxidant, anti-inflammatory and anti-cancer properties. In this study, we investigated the anti-proliferative effect of quercetin in two breast cancer cell lines (MCF-7 and MDA-MB-231, which differed in hormone receptor. IC50 value (37μM of quercetin showed significant cytotoxicity in MCF-7 cells, which was not observed in MDA-MB-231 cells even at 100μM of quercetin treatment. To study the response of cancer cells to quercetin, with respect to different hormone receptors, both the cell lines were treated with a fixed concentration (40μM of quercetin. MCF-7 cells on quercetin treatment showed more apoptotic cells with G1 phase arrest. In addition, quercetin effectively suppressed the expression of CyclinD1, p21, Twist and phospho p38MAPK, which was not observed in MDA-MB-231 cells. To analyse the molecular mechanism of quercetin in exerting an apoptotic effect in MCF-7 cells, Twist was over-expressed and the molecular changes were observed after quercetin administration. Quercetin effectively regulated the expression of Twist, in turn p16 and p21 which induced apoptosis in MCF-7 cells. In conclusion, quercetin induces apoptosis in breast cancer cells through suppression of Twist via p38MAPK pathway.

  9. Quercetin Suppresses Twist to Induce Apoptosis in MCF-7 Breast Cancer Cells

    Science.gov (United States)

    Ranganathan, Santhalakshmi; Halagowder, Devaraj; Sivasithambaram, Niranjali Devaraj

    2015-01-01

    Quercetin is a dietary flavonoid which exerts anti-oxidant, anti-inflammatory and anti-cancer properties. In this study, we investigated the anti-proliferative effect of quercetin in two breast cancer cell lines (MCF-7 and MDA-MB-231), which differed in hormone receptor. IC50 value (37μM) of quercetin showed significant cytotoxicity in MCF-7 cells, which was not observed in MDA-MB-231 cells even at 100μM of quercetin treatment. To study the response of cancer cells to quercetin, with respect to different hormone receptors, both the cell lines were treated with a fixed concentration (40μM) of quercetin. MCF-7 cells on quercetin treatment showed more apoptotic cells with G1 phase arrest. In addition, quercetin effectively suppressed the expression of CyclinD1, p21, Twist and phospho p38MAPK, which was not observed in MDA-MB-231 cells. To analyse the molecular mechanism of quercetin in exerting an apoptotic effect in MCF-7 cells, Twist was over-expressed and the molecular changes were observed after quercetin administration. Quercetin effectively regulated the expression of Twist, in turn p16 and p21 which induced apoptosis in MCF-7 cells. In conclusion, quercetin induces apoptosis in breast cancer cells through suppression of Twist via p38MAPK pathway. PMID:26491966

  10. Dormancy of cancer cells with suppression of AKT activity contributes to survival in chronic hypoxia.

    Directory of Open Access Journals (Sweden)

    Hiroko Endo

    Full Text Available A hypoxic microenvironment in tumors has been recognized as a cause of malignancy or resistance to various cancer therapies. In contrast to recent progress in understanding the acute response of cancer cells to hypoxia, the characteristics of tumor cells in chronic hypoxia remain elusive. We have identified a pancreatic cancer cell line, AsPC-1, that is exceptionally able to survive for weeks under 1% oxygen conditions while most tested cancer cell lines die after only some days under these conditions. In chronic hypoxia, AsPC-1 cells entered a state of dormancy characterized by no proliferation, no death, and metabolic suppression. They reversibly switched to active status after being placed again in optimal culture conditions. ATP turnover, an indicator of energy demand, was markedly decreased and accompanied by reduced AKT phosphorylation. Forced activation of AKT resulted in increased ATP turnover and massive cell death in vitro and a decreased number of dormant cells in vivo. In contrast to most cancer cell lines, primary-cultured colorectal cancer cells easily entered the dormant status with AKT suppression under hypoxia combined with growth factor-depleted conditions. Primary colorectal cancer cells in dormancy were resistant to chemotherapy. Thus, the ability to survive in a deteriorated microenvironment by entering into dormancy under chronic hypoxia might be a common property among cancer cells. Targeting the regulatory mechanism inducing this dormant status could provide a new strategy for treating cancer.

  11. Simian Immunodeficiency Virus-Producing Cells in Follicles Are Partially Suppressed by CD8+ Cells In Vivo

    Science.gov (United States)

    Li, Shengbin; Folkvord, Joy M.; Rakasz, Eva G.; Abdelaal, Hadia M.; Wagstaff, Reece K.; Kovacs, Katalin J.; Kim, Hyeon O.; Sawahata, Ryoko; MaWhinney, Samantha; Masopust, David; Connick, Elizabeth

    2016-01-01

    ABSTRACT Human immunodeficiency virus (HIV)- and simian immunodeficiency virus (SIV)-specific CD8+ T cells are typically largely excluded from lymphoid B cell follicles, where HIV- and SIV-producing cells are most highly concentrated, indicating that B cell follicles are somewhat of an immunoprivileged site. To gain insights into virus-specific follicular CD8+ T cells, we determined the location and phenotype of follicular SIV-specific CD8+ T cells in situ, the local relationship of these cells to Foxp3+ cells, and the effects of CD8 depletion on levels of follicular SIV-producing cells in chronically SIV-infected rhesus macaques. We found that follicular SIV-specific CD8+ T cells were able to migrate throughout follicular areas, including germinal centers. Many expressed PD-1, indicating that they may have been exhausted. A small subset was in direct contact with and likely inhibited by Foxp3+ cells, and a few were themselves Foxp3+. In addition, subsets of follicular SIV-specific CD8+ T cells expressed low to medium levels of perforin, and subsets were activated and proliferating. Importantly, after CD8 depletion, the number of SIV-producing cells increased in B cell follicles and extrafollicular areas, suggesting that follicular and extrafollicular CD8+ T cells have a suppressive effect on SIV replication. Taken together, these results suggest that during chronic SIV infection, despite high levels of exhaustion and likely inhibition by Foxp3+ cells, a subset of follicular SIV-specific CD8+ T cells are functional and suppress viral replication in vivo. These findings support HIV cure strategies that augment functional follicular virus-specific CD8+ T cells to enhance viral control. IMPORTANCE HIV- and SIV-specific CD8+ T cells are typically largely excluded from lymphoid B cell follicles, where virus-producing cells are most highly concentrated, suggesting that B cell follicles are somewhat of an immunoprivileged site where virus-specific CD8+ T cells are not

  12. Influence of heavy ions on cell survival, cytogenetic damage and mitochondrial function of human endothelial cells

    Science.gov (United States)

    Ritter, Sylvia; Helm, Alexander; Lee, Ryonfa; Pollet, Dieter; Durante, Marco

    There is increasing evidence that there is an elevated risk of cardiovascular disease among atomic bomb survivors and radiotherapy patients, typically developing with a long latency. However, essentially no information is available on the potential cardiovascular risks associated with space radiation, in particular heavy ions. To address this issue, we have chosen human umbilical vein endothelial cells (HUVEC) as a model system. Cells at an early passage number were irradiated with 0.1 to 4 Gy of either 9.8 MeV/u C-ions (LET=170 keV/µm), 91 MeV/u C-ions (LET=29 keV/µm) or 250 kV X-rays. Cells were regularly subcultured up to 40 days (20 population doublings) post-irradiation. Immediately after exposure cell inactivation was deter-mined by the colony forming assay. Furthermore, at selected time-points cytogenetic damage (formation of micronuclei in binucleated cells) and the mitochondrial membrane potential ΨM (flow cytometric analysis following JC-1 staining) were assessed. Measurement of the directly induced radiation damage showed that 9.8 MeV/u and 91 MeV/u C-ions were more effective than X-rays (i.e. about 3 and 2 times, respectively) with respect to cell inactivation or the in-duction of cytogenetic damage. At the subsequent days in the irradiated cultures the number of cells with micronuclei declined to the control level (3-5Altogether our data indicate that under the applied radiation conditions the integrity of mitochondria which play a significant role in the regulation of cardiovascular cell function is not impaired. With respect to directly induced genetic damage C-ions are more effective than X-rays as observed in other cell systems. If the effectiveness of charged particles for the occurrence of late chromosomal damage in endothelial cells is higher than that of sparsely ionizing radiation needs further clarification. The data obtained up to now indicate that sophisticated cytogenetic techniques have to be applied in order to draw any firm

  13. Identification of a single chromosome in the normal human genome essential for suppression of hamster cell transformation.

    OpenAIRE

    Stoler, A; Bouck, N

    1985-01-01

    Normal human fibroblasts were fused to carcinogen-transformed baby hamster kidney (BHK) cells and found to be able to suppress the anchorage-independent transformed phenotype of the hamster cells. This suppression was not due to interspecies incompatibility, for transformation could be effectively expressed in hybrids if either the human or the BHK parent had initially been transformed by a dominantly acting viral genome. Upon growth of suppressed hybrids, loss of human chromosomes was accomp...

  14. Eckol suppresses maintenance of stemness and malignancies in glioma stem-like cells

    International Nuclear Information System (INIS)

    Hyun, Kyung-Hwan; Yoon, Chang-Hwan; Kim, Rae-Kwon; Lim, Eun-Jung; An, Sungkwan; Park, Myung-Jin; Hyun, Jin-Won; Suh, Yongjoon; Kim, Min-Jung; Lee, Su-Jae

    2011-01-01

    A subpopulation of cancer cells with stem cell properties is responsible for tumor maintenance and progression, and may contribute to resistance to anticancer treatments. Thus, compounds that target cancer stem-like cells could be usefully applied to destroy cancer. In this study, we investigated the effect of Eckol, a phlorotannin compound, on stemness and malignancies in glioma stem-like cells. To determine whether Eckol targets glioma stem-like cells, we examined whether Eckol treatment could change the expression levels of glioma stem-like cell markers and self-renewal-related proteins as well as the sphere forming ability, and the sensitivity to anticancer treatments. Alterations in the malignant properties of sphere-derived cells by Eckol were also investigated by soft-agar colony forming assay, by xenograft assay in nude mice, and by cell invasion assay. Treatment of sphere-forming glioma cells with Eckol effectively decreased the sphere formation as well as the CD133 + cell population. Eckol treatment suppressed expression of the glioma stem-like cell markers and the self-renewal-related proteins without cell death. Moreover, treatment of glioma stem-like cells with Eckol significantly attenuated anchorage-independent growth on soft agar and tumor formation in xenograft mice. Importantly, Eckol treatment effectively reduced the resistance of glioma stem-like cells to ionizing radiation and temozolomide. Treatment of glioma stem-like cells with Eckol markedly blocked both phosphoinositide 3-kinase-Akt and Ras-Raf-1-Erk signaling pathways. These results indicate that the natural phlorotannin Eckol suppresses stemness and malignancies in glioma stem-like cells, and thereby makes glioma stem-like cells more sensitive to anticancer treatments, providing novel therapeutic strategies targeting specifically cancer stem-like cells.

  15. Curcumin suppresses growth of mesothelioma cells in vitro and in vivo, in part, by stimulating apoptosis.

    Science.gov (United States)

    Wang, Ying; Rishi, Arun K; Wu, Wenjuan; Polin, Lisa; Sharma, Sunita; Levi, Edi; Albelda, Steven; Pass, Harvey I; Wali, Anil

    2011-11-01

    Malignant pleural mesothelioma (MPM) is an aggressive, asbestos-related malignancy of the thoracic pleura. Although, platinum-based agents are the first line of therapy, there is an urgent need for second-line therapies to treat the drug-resistant MPM. Cell cycle as well as apoptosis pathways are frequently altered in MPM and thus remain attractive targets for intervention strategies. Curcumin, the major component in the spice turmeric, alone or in combination with other chemotherapeutics has been under investigation for a number of cancers. In this study, we investigated the biological and molecular responses of MPM cells to curcumin treatments and the mechanisms involved. Flow-cytometric analyses coupled with western immunoblotting and gene-array analyses were conducted to determine mechanisms of curcumin-dependent growth suppression of human (H2373, H2452, H2461, and H226) and murine (AB12) MPM cells. Curcumin inhibited MPM cell growth in a dose- and time-dependent manner while pretreatment of MPM cells with curcumin enhanced cisplatin efficacy. Curcumin activated the stress-activated p38 kinase, caspases 9 and 3, caused elevated levels of proapoptotic proteins Bax, stimulated PARP cleavage, and apoptosis. In addition, curcumin treatments stimulated expression of novel transducers of cell growth suppression such as CARP-1, XAF1, and SULF1 proteins. Oral administration of curcumin inhibited growth of murine MPM cell-derived tumors in vivo in part by stimulating apoptosis. Thus, curcumin targets cell cycle and promotes apoptosis to suppress MPM growth in vitro and in vivo. Our studies provide a proof-of-principle rationale for further in-depth analysis of MPM growth suppression mechanisms and their future exploitation in effective management of resistant MPM.

  16. Curcumin inhibits bladder cancer stem cells by suppressing Sonic Hedgehog pathway.

    Science.gov (United States)

    Wang, Dengdian; Kong, Xiaochuan; Li, Yuan; Qian, Weiwei; Ma, Jiaxing; Wang, Daming; Yu, Dexin; Zhong, Caiyun

    2017-11-04

    Cancer stem cells (CSCs) is responsible for the recurrence of human cancers. Thus, targeting CSCs is considered to be a valid way for human cancer treatment. Curcumin is a major component of phytochemicals that exerts potent anticancer activities. However, the effect of curcumin on bladder cancer stem cells (BCSCs) remains to be elucidated. In this study, we investigated the mechanism of curcumin suppressing bladder cancer stem cells. In this study, UM-UC-3 and EJ cells were cultured in serum-free medium (SFM) to form cell spheres that was characterized as BCSCs. Then cell spheres were separately treated with different concentrations of curcumin and purmorphamine. Cell cycle analysis were used to determine the percentage of cells in different phases. Western blot and quantitative real-time PCR analysis were used to detect the expression of relative molecules. Immunofluorescence staining analysis were also utilized to measure the protein level of CD44. We found that CSC markers, including CD44, CD133, ALDH1-A1, OCT-4 and Nanog, were obviously highly expressed in cell spheres. Moreover, we observed that curcumin reduced the cell spheres formation, decreased the expression of CSC markers, suppressed cell proliferation and induced cell apoptosis. We also found that curcumin inhibited the activation of Shh pathway, while the inhibitory effects of curcumin on BCSCs could be weakened by upregulation of Sonic Hedgehog (Shh) pathway. Altogether, these data suggested that curcumin inhibited the activities of BCSCs through suppressing Shh pathway, which might be an effective chemopreventive agent for bladder cancer intervention. Copyright © 2017. Published by Elsevier Inc.

  17. E2F1 enhances glycolysis through suppressing Sirt6 transcription in cancer cells.

    Science.gov (United States)

    Wu, Minghui; Seto, Edward; Zhang, Jingsong

    2015-05-10

    The fast proliferation of cancer cells requires reprogramming of its energy metabolism with aerobic glycolysis as a major energy source. Sirt6, a class III histone deacetylase, has been shown to down regulate glycolysis by inhibiting the expression of several key glycolytic genes. Based on the published study on the metabolic phenotype of E2F1 -/- mice and SIRT6 -/- mice, we hypothesize that E2F1 enhances glycolysis and inhibits the expression of Sirt6. Indeed, over-expressing of E2F1, but not its DNA binding deficient mutant, significantly enhanced glucose uptake and lactate production in bladder and prostate cancer cell lines. E2F1 over-expression also suppressed Sirt6 expression and function. Moreover, E2F1 directly bound to Sirt6 promoter and suppressed Sirt6 promoter activity under both normoxic and hypoxic culture conditions. E2F1 siRNA blocked the up-regulation of E2F1 under hypoxia, increased Sirt6 expression and decreased glycolysis compared to those of scrambled siRNA transected cells. Furthermore, HDAC1 deacetylated E2F1 and diminished its transcription suppression of Sirt6 promoter. Treatment with the HDAC inhibitor, trichostatin A (TSA), suppressed Sirt6 promoter activity with increased binding of acetylated E2F1 to Sirt6 promoter. Mutating the E2F1 binding site on the proximal Sirt6 promoter abolished the suppression of Sirt6 transcription by TSA. These data indicate a novel oncogenic role of E2F1, i.e. enhancing glycolysis by suppressing Sirt6 transcription.

  18. Bacillus thuringiensis membrane-damaging toxins acting on mammalian cells.

    Science.gov (United States)

    Celandroni, Francesco; Salvetti, Sara; Senesi, Sonia; Ghelardi, Emilia

    2014-12-01

    Bacillus thuringiensis is widely used as a biopesticide in forestry and agriculture, being able to produce potent species-specific insecticidal toxins and considered nonpathogenic to other animals. More recently, however, repeated observations are documenting the association of this microorganism with various infectious diseases in humans, such as food-poisoning-associated diarrheas, periodontitis, bacteremia, as well as ocular, burn, and wound infections. Similar to B. cereus, B. thuringiensis produces an array of virulence factors acting against mammalian cells, such as phosphatidylcholine- and phosphatidylinositol-specific phospholipase C (PC-PLC and PI-PLC), hemolysins, in particular hemolysin BL (HBL), and various enterotoxins. The contribution of some of these toxins to B. thuringiensis pathogenicity has been studied in animal models of infection, following intravitreous, intranasal, or intratracheal inoculation. These studies lead to the speculation that the activities of PC-PLC, PI-PLC, and HBL are responsible for most of the pathogenic properties of B. thuringiensis in nongastrointestinal infections in mammals. This review summarizes data regarding the biological activity, the genetic basis, and the structural features of these membrane-damaging toxins. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  19. Laminarin protects against hydrogen peroxide-induced oxidative damage in MRC-5 cells possibly via regulating NRF2.

    Science.gov (United States)

    Liu, Xue; Liu, Huaman; Zhai, Yi; Li, Yan; Zhu, Xue; Zhang, Wei

    2017-01-01

    Oxidative damage is a major cause of lung diseases, including pulmonary fibrosis. Laminarin is a kind of polysaccharide extracted from brown algae and plays vital roles in various biological processes. However, the functions and mechanisms of laminarin in pulmonary oxidative damage are poorly understood. This study aimed at investigating the protective effect of laminarin against pulmonary oxidative damage and underlying mechanisms. Human lung fibroblasts MRC-5 cells were treated with hydrogen peroxide to induce oxidative damage. Laminarin treatment was performed before or after hydrogen peroxide treatment, and then major indexes of oxidative damage, including superoxide dismutase (SOD), malondialdehyde (MDA), reduced glutathione (GSH) and catalase (CAT), were quantified by biochemical assays. The expression of oxidation-related factor, nuclear factor erythroid 2 like 2 (NRF2) was analyzed by qPCR, Western blot and immunofluorescence assay. NRF2 knockdown and overexpression were performed by cell transfection to reveal possible mechanisms. Results showed that laminarin treatment of 0.020 mg/mL for 24 h, especially the pre-treatment, could significantly relieve changes in SOD, MDA, GSH and CAT that were altered by hydrogen peroxide, and promote NRF2 mRNA ( P  < 0.001). NRF2 protein was also elevated by laminarin, and nuclear translocation was observed. Factors in NRF2 signaling pathways, including KEAP1, NQO1, GCLC and HO1, were all regulated by laminarin. Roles of NRF2 were tested, suggesting that NRF2 regulated the concentration of SOD, MDA, GSH and CAT, suppressed KEAP1, and promoted NQO1, GCLC and HO1. These findings suggested the protective role of laminarin against pulmonary oxidative damage, which might involve the regulation of NRF2 signaling pathways. This study provided information for the clinical application of laminarin to pulmonary diseases like pulmonary fibrosis.

  20. TRIM45 negatively regulates NF-κB-mediated transcription and suppresses cell proliferation

    International Nuclear Information System (INIS)

    Shibata, Mio; Sato, Tomonobu; Nukiwa, Ryota; Ariga, Tadashi; Hatakeyama, Shigetsugu

    2012-01-01

    Highlights: ► NF-κB plays an important role in cell survival and carcinogenesis. ► TRIM45 negatively regulates TNFα-induced NF-κB-mediated transcription. ► TRIM45 overexpression suppresses cell growth. ► TRIM45 acts as a repressor for the NF-κB signal and regulates cell growth. -- Abstract: The NF-κB signaling pathway plays an important role in cell survival, immunity, inflammation, carcinogenesis, and organogenesis. Activation of NF-κB is regulated by several posttranslational modifications including phosphorylation, neddylation and ubiquitination. The NF-κB signaling pathway is activated by two distinct signaling mechanisms and is strictly modulated by the ubiquitin–proteasome system. It has been reported that overexpression of TRIM45, one of the TRIM family ubiquitin ligases, suppresses transcriptional activities of Elk-1 and AP-1, which are targets of the MAPK signaling pathway. In this study, we showed that TRIM45 also negatively regulates TNFα-induced NF-κB-mediated transcription by a luciferase reporter assay and that TRIM45 lacking a RING domain also has an activity to inhibit the NF-κB signal. Moreover, we found that TRIM45 overexpression suppresses cell growth. These findings suggest that TRIM45 acts as a repressor for the NF-κB signal and regulates cell growth.

  1. Speckle noise suppression using a helix-free ferroelectric liquid crystal cell

    Energy Technology Data Exchange (ETDEWEB)

    Andreev, A L; Andreeva, T B; Kompanets, I N [P N Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation); Zalyapin, N V [National Research Nuclear University ' ' MEPhI' ' (Russian Federation)

    2014-12-31

    We have studied the method for suppressing speckle noise in patterns produced by a laser based on a fast-response electro-optical cell with a ferroelectric liquid crystal (FLC) in which helicoid is absent, i.e., compensated for. The character of smectic layer deformation in an electric field is considered along with the mechanism of spatially inhomogeneous phase modulation of a laser beam passing through the cell which is accompanied by the destruction of phase relations in the beam. Advantages of a helix-free FLC cell are pointed out as compared to helical crystal cells studied previously. (liquid crystal devices)

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

    Directory of Open Access Journals (Sweden)

    Junichiro En

    2017-08-01

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

  3. Cyclin F suppresses B-Myb activity to promote cell cycle checkpoint control

    DEFF Research Database (Denmark)

    Klein, Ditte Kjærsgaard; Hoffmann, Saskia; Ahlskog, Johanna K

    2015-01-01

    an important role in checkpoint control following ionizing radiation. Cyclin F-depleted cells initiate checkpoint signalling after ionizing radiation, but fail to maintain G2 phase arrest and progress into mitosis prematurely. Importantly, cyclin F suppresses the B-Myb-driven transcriptional programme...... that promotes accumulation of crucial mitosis-promoting proteins. Cyclin F interacts with B-Myb via the cyclin box domain. This interaction is important to suppress cyclin A-mediated phosphorylation of B-Myb, a key step in B-Myb activation. In summary, we uncover a regulatory mechanism linking the F-box protein...

  4. Chk1 suppresses bypass of mitosis and tetraploidization in p53-deficient cancer cells.

    Science.gov (United States)

    Wilsker, Deborah; Chung, Jon H; Bunz, Fred

    2012-04-15

    Many cancer cells are unable to maintain a numerically stable chromosome complement. It is well established that aberrant cell division can generate progeny with increased ploidy, but the genetic factors required for maintenance of diploidy are not well understood. Using an isogenic model system derived by gene targeting, we examined the role of Chk1 in p53-proficient and -deficient cancer cells. Targeted inactivation of a single CHK1 allele in stably diploid cells caused an elevated frequency of mitotic bypass if p53 was naturally mutated or experimentally disrupted by homologous recombination. CHK1-haploinsufficient, p53-deficient cells frequently underwent sequential rounds of DNA synthesis without an intervening mitosis. These aberrant cell cycles resulted in whole-genome endoreduplication and tetraploidization. The unscheduled bypass of mitosis could be suppressed by targeted reversion of a p53 mutation or by exogenous expression of Cdk1. In contrast, the number of tetraploid cells was not increased in isogenic cell populations that harbor hypomorphic ATR mutations, suggesting that suppression of unscheduled mitotic bypass is a distinct function of Chk1. These results are consistent with a recently described role for Chk1 in promoting the expression of genes that promote cell cycle transitions and demonstrate how Chk1 might prevent tetraploidization during the cancer cell cycle.

  5. Rapamycin Suppresses Tumor Growth and Alters the Metabolic Phenotype in T-Cell Lymphoma.

    Science.gov (United States)

    Kittipongdaja, Wasakorn; Wu, Xuesong; Garner, Justine; Liu, Xiping; Komas, Steven M; Hwang, Sam T; Schieke, Stefan M

    2015-09-01

    The mTOR pathway is a master regulator of cellular growth and metabolism. The biosynthetic and energetic demand of rapidly proliferating cells such as cancer cells is met by metabolic adaptations such as an increased glycolytic rate known as the Warburg effect. Herein, we characterize the anti-tumor effect of rapamycin in a mouse model of T-cell lymphoma and examine the metabolic effects in vitro. The murine T-cell lymphoma line, MBL2, and human cutaneous T-cell lymphoma (CTCL) lines, HH and Hut78, were used in syngeneic or standard NSG mouse models to demonstrate a marked suppression of tumor growth by rapamycin accompanied by inhibition of mTORC1/2. Analysis of the metabolic phenotype showed a substantial reduction in the glycolytic rate and glucose utilization in rapamycin-treated lymphoma cells. This was associated with reduced expression of glucose transporters and glycolytic enzymes in cultured cells and xenograft tumors. As a result of the decrease in glycolytic state, rapamycin-treated cells displayed reduced sensitivity to low-glucose conditions but continued to rely on mitochondrial oxidative phosphorylation (OXPHOS) with sensitivity to inhibition of OXPHOS. Taken together, we demonstrate that rapamycin suppresses growth of T-cell lymphoma tumors and leads to a reduction in aerobic glycolysis counteracting the Warburg effect of cancer cells.

  6. Targeting of the Hedgehog signal transduction pathway suppresses survival of malignant pleural mesothelioma cells in vitro.

    Science.gov (United States)

    You, Min; Varona-Santos, Javier; Singh, Samer; Robbins, David J; Savaraj, Niramol; Nguyen, Dao M

    2014-01-01

    The present study sought to determine whether the Hedgehog (Hh) pathway is active and regulates the cell growth of cultured malignant pleural mesothelioma (MPM) cells and to evaluate the efficacy of pathway blockade using smoothened (SMO) antagonists (SMO inhibitor GDC-0449 or the antifungal drug itraconazole [ITRA]) or Gli inhibitors (GANT61 or the antileukemia drug arsenic trioxide [ATO]) in suppressing MPM viability. Selective knockdown of SMO to inhibit Hh signaling was achieved by small interfering RNA in 3 representative MPM cells. The growth inhibitory effect of GDC-0449, ITRA, GANT61, and ATO was evaluated in 8 MPM lines, with cell viability quantified using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cell death was determined by annexinV/propidium iodide staining and flow cytometry. SMO small interfering RNA mediated a two- to more than fivefold reduction of SMO and Gli1 gene expression as determined by real-time quantitative reverse-transcriptase polymerase chain reaction, indicating significant Hh pathway blockade. This was associated with significantly reduced cell viability (34% ± 7% to 61% ± 14% of nontarget small interfering RNA controls; P = .0024 to P = .043). Treating MPM cells with Hh inhibitors resulted in a 1.5- to 4-fold reduction of Gli1 expression. These 4 Hh antagonists strongly suppressed MPM cell viability. More importantly, ITRA, ATO, GANT61 induced significant apoptosis in the representative MPM cells. Hh signaling is active in MPM and regulates cell viability. ATO and ITRA were as effective as the prototypic SMO inhibitor GDC-0449 and the Gli inhibitor GANT61 in suppressing Hh signaling in MPM cells. Pharmaceutical agents Food and Drug Administration-approved for other indications but recently found to have anti-Hh activity, such as ATO or ITRA, could be repurposed to treat MPM. Copyright © 2014 The American Association for Thoracic Surgery. All rights reserved.

  7. Maslinic acid inhibits proliferation of renal cell carcinoma cell lines and suppresses angiogenesis of endothelial cells

    Directory of Open Access Journals (Sweden)

    Parth Thakor

    2017-03-01

    Full Text Available Despite the introduction of many novel therapeutics in clinical practice, metastatic renal cell carcinoma (RCC remains a treatment-re-sistant cancer. As red and processed meat are considered risk factors for RCC, and a vegetable-rich diet is thought to reduce this risk, research into plant-based therapeutics may provide valuable complementary or alternative therapeutics for the management of RCC. Herein, we present the antiproliferative and antiangiogenic effects of maslinic acid, which occurs naturally in edible plants, particularly in olive fruits, and also in a variety of medicinal plants. Human RCC cell lines (ACHN, Caki-1, and SN12K1, endothelial cells (human umbilical vein endothelial cell line [HUVEC], and primary cultures of kidney proximal tubular epithelial cells (PTEC were treated with maslinic acid. Maslinic acid was relatively less toxic to PTEC when compared with RCC under similar experimental conditions. In RCC cell lines, maslinic acid induced a significant reduction in proliferation, proliferating cell nuclear antigen, and colony formation. In HUVEC, maslinic acid induced a significant reduction in capillary tube formation in vitro and vascular endothelial growth factor. This study provides a rationale for incorporating a maslinic acid–rich diet either to reduce the risk of developing kidney cancer or as an adjunct to existing antiangiogenic therapy to improve efficacy.

  8. Multifaceted effects of synthetic TLR2 ligand and Legionella pneumophilia on Treg-mediated suppression of T cell activation

    Directory of Open Access Journals (Sweden)

    Sutmuller Roger PM

    2011-03-01

    Full Text Available Abstract Background Regulatory T cells (Treg play a crucial role in maintaining immune homeostasis and self-tolerance. The immune suppressive effects of Tregs should however be limited in case effective immunity is required against pathogens or cancer cells. We previously found that the Toll-like receptor 2 (TLR2 agonist, Pam3CysSK4, directly stimulated Tregs to expand and temporarily abrogate their suppressive capabilities. In this study, we evaluate the effect of Pam3CysSK4 and Legionella pneumophila, a natural TLR2 containing infectious agent, on effector T (Teff cells and dendritic cells (DCs individually and in co-cultures with Tregs. Results TLR2 agonists can directly provide a co-stimulatory signal inducing enhanced proliferation and cytokine production of naive CD4+ Teff cells. With respect to cytokine production, DCs appear to be most sensitive to low amounts of TLR agonists. Using wild type and TLR2-deficient cells in Treg suppression assays, we accordingly show that all cells (e.g. Treg, Teff cells and DCs contributed to overcome Treg-mediated suppression of Teff cell proliferation. Furthermore, while TLR2-stimulated Tregs readily lost their ability to suppress Teff cell proliferation, cytokine production by Teff cells was still suppressed. Similar results were obtained upon stimulation with TLR2 ligand containing bacteria, Legionella pneumophila. Conclusions These findings indicate that both synthetic and natural TLR2 agonists affect DCs, Teff cells and Treg directly, resulting in multi-modal modulation of Treg-mediated suppression of Teff cells. Moreover, Treg-mediated suppression of Teff cell proliferation is functionally distinct from suppression of cytokine secretion.

  9. Human dental stem cells suppress PMN activity after infection with the periodontopathogens Prevotella intermedia and Tannerella forsythia.

    Science.gov (United States)

    Hieke, Cathleen; Kriebel, Katja; Engelmann, Robby; Müller-Hilke, Brigitte; Lang, Hermann; Kreikemeyer, Bernd

    2016-12-15

    Periodontitis is characterized by inflammation associated with the colonization of different oral pathogens. We here aimed to investigate how bacteria and host cells shape their environment in order to limit inflammation and tissue damage in the presence of the pathogen. Human dental follicle stem cells (hDFSCs) were co-cultured with gram-negative P. intermedia and T. forsythia and were quantified for adherence and internalization as well as migration and interleukin secretion. To delineate hDFSC-specific effects, gingival epithelial cells (Ca9-22) were used as controls. Direct effects of hDFSCs on neutrophils (PMN) after interaction with bacteria were analyzed via chemotactic attraction, phagocytic activity and NET formation. We show that P. intermedia and T. forsythia adhere to and internalize into hDFSCs. This infection decreased the migratory capacity of the hDFSCs by 50%, did not disturb hDFSC differentiation potential and provoked an increase in IL-6 and IL-8 secretion while leaving IL-10 levels unaltered. These environmental modulations correlated with reduced PMN chemotaxis, phagocytic activity and NET formation. Our results suggest that P. intermedia and T. forsythia infected hDFSCs maintain their stem cell functionality, reduce PMN-induced tissue and bone degradation via suppression of PMN-activity, and at the same time allow for the survival of the oral pathogens.

  10. Advanced Simulation Tool for Improved Damage Assessment 2) Water-Mist Suppression of Large Scale Compartment Fires

    National Research Council Canada - National Science Library

    Prasad, Kuldeep

    2000-01-01

    .... In this report, we focus on simulating water-mist suppression of fires in large enclosures. A two-continuum formulation is used in which the gas phase and the water-mist are both described by equations of the Eulerian form...

  11. Salmon cartilage proteoglycan suppresses mouse experimental colitis through induction of Foxp3{sup +} regulatory T cells

    Energy Technology Data Exchange (ETDEWEB)

    Mitsui, Toshihito [Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine, Zaifu-cho 5, Hirosaki, Aomori 036-8562 (Japan); Department of Digestive Surgery, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori 036-8562 (Japan); Sashinami, Hiroshi [Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine, Zaifu-cho 5, Hirosaki, Aomori 036-8562 (Japan); Sato, Fuyuki; Kijima, Hiroshi [Department of Pathology and Bioscience, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori 036-8562 (Japan); Ishiguro, Yoh; Fukuda, Shinsaku [Department of Digestive Internal Medicine, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori 036-8562 (Japan); Yoshihara, Shuichi [Department of Glycomedicine, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori 036-8562 (Japan); Hakamada, Ken-Ichi [Department of Digestive Surgery, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori 036-8562 (Japan); Nakane, Akio, E-mail: a27k03n0@cc.hirosaki-u.ac.jp [Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine, Zaifu-cho 5, Hirosaki, Aomori 036-8562 (Japan)

    2010-11-12

    Research highlights: {yields} Salmon proteoglycan suppresses IL-10{sup -/-} cell transfer-induced colitis progression. {yields} Salmon proteoglycan suppresses Th1- and Th17-related factors in colitis mice. {yields} Salmon proteoglycan enhances Foxp3 expression. -- Abstract: Proteoglycans (PGs) are complex glycohydrates which are widely distributed in extracellular matrix (ECM). PGs are involved in the construction of ECM, cell proliferation and differentiation. ECM components are involved in transduction of proinflammatory responses, but it is still unknown whether PGs are involved in inflammatory response. In this study, we investigated the effect of PG extracted from salmon cartilage on the progression of experimental colitis-induced in severe combined immunodeficiency mice by cell transfer from interleukin-10 (IL-10){sup -/-} mice. IL-10{sup -/-} cell-transferred mice showed weight loss, colon shortening and histological appearance of mild colitis. Daily oral administration of PG attenuated the clinical progression of colitis in a dose-dependent manner. Colitis-induced mice showed the elevated expression of IFN-{gamma}, IL-12, TNF-{alpha}, IL-21, IL-23p19, IL-6, IL-17A and retinoic acid-related orphan receptor {gamma}t (ROR{gamma}t) in lamina propria mononuclear cells (LPMCs) and oral administration of PG suppressed the expression of these factors. Conversely, expression of Foxp3 that induces CD4{sup +}CD25{sup +} regulatory T cells in LPMCs was enhanced by PG administration. These findings suggested that salmon PG attenuated the progression of colitis due to suppression of inflammatory response by enhancement of regulatory T cell induction.

  12. ShaPINg cell fate upon DNA damage:role of Pin1 isomerase in DNA damage-induced cell death and repair

    Directory of Open Access Journals (Sweden)

    Thomas G Hofmann

    2014-06-01

    Full Text Available The peptidyl-prolyl cis/trans isomerase Pin1 acts as a molecular timer in proline-directed Ser/Thr kinase signaling and shapes cellular responses based on recognition of phosphorylation marks and implementing conformational changes in its substrates. Accordingly, Pin1 has been linked to numerous phosphorylation-controlled signaling pathways and cellular processes such as cell cycle progression, proliferation and differentiation. In addition, Pin1 plays a pivotal role in DNA damage-triggered cell fate decisions. Whereas moderate DNA damage is balanced by DNA repair, cells confronted with massive genotoxic stress are eliminated by the induction of programmed cell death or cellular senescence. In this review we summarize and discuss the current knowledge on how Pin1 specifies cell fate through regulating key players of the apoptotic and the repair branch of the DNA damage response.

  13. DNA Damage, Cell Cycle Arrest, and Apoptosis Induction Caused by Lead in Human Leukemia Cells

    Directory of Open Access Journals (Sweden)

    Clement G. Yedjou

    2015-12-01

    Full Text Available In recent years, the industrial use of lead has been significantly reduced from paints and ceramic products, caulking, and pipe solder. Despite this progress, lead exposure continues to be a significant public health concern. The main goal of this research was to determine the in vitro mechanisms of lead nitrate [Pb(NO32] to induce DNA damage, apoptosis, and cell cycle arrest in human leukemia (HL-60 cells. To reach our goal, HL-60 cells were treated with different concentrations of Pb(NO32 for 24 h. Live cells and necrotic death cells were measured by the propidium idiode (PI assay using the cellometer vision. Cell apoptosis was measured by the flow cytometry and DNA laddering. Cell cycle analysis was evaluated by the flow cytometry. The result of the PI demonstrated a significant (p < 0.05 increase of necrotic cell death in Pb(NO32-treated cells, indicative of membrane rupture by Pb(NO32 compared to the control. Data generated from the comet assay indicated a concentration-dependent increase in DNA damage, showing a significant increase (p < 0.05 in comet tail-length and percentages of DNA cleavage. Data generated from the flow cytometry assessment indicated that Pb(NO32 exposure significantly (p < 0.05 increased the proportion of caspase-3 positive cells (apoptotic cells compared to the control. The flow cytometry assessment also indicated Pb(NO32 exposure caused cell cycle arrest at the G0/G1 checkpoint. The result of DNA laddering assay showed presence of DNA smear in the agarose gel with little presence of DNA fragments in the treated cells compared to the control. In summary, Pb(NO32 inhibits HL-60 cells proliferation by not only inducing DNA damage and cell cycle arrest at the G0/G1 checkpoint but also triggering the apoptosis through caspase-3 activation and nucleosomal DNA fragmentation accompanied by secondary necrosis. We believe that our study provides a new insight into the mechanisms of Pb(NO32 exposure and its associated adverse

  14. Resveratrol suppresses IGF-1 induced human colon cancer cell proliferation and elevates apoptosis via suppression of IGF-1R/Wnt and activation of p53 signaling pathways

    Directory of Open Access Journals (Sweden)

    Radhakrishnan Sridhar

    2010-05-01

    Full Text Available Abstract Background Obesity is a global phenomenon and is associated with various types of cancer, including colon cancer. There is a growing interest for safe and effective bioactive compounds that suppress the risk for obesity-promoted colon cancer. Resveratrol (trans-3, 4', 5,-trihydroxystilbene, a stilbenoid found in the skin of red grapes and peanuts suppresses many types of cancers by regulating cell proliferation and apoptosis through a variety of mechanisms, however, resveratrol effects on obesity-promoted colon cancer are not clearly established. Methods We investigated the anti-proliferative effects of resveratrol on HT-29 and SW480 human colon cancer cells in the presence and absence of insulin like growth factor-1 (IGF-1; elevated during obesity and elucidated the mechanisms of action using IGF-1R siRNA in HT-29 cells which represents advanced colon carcinogenesis. Results Resveratrol (100-150 μM exhibited anti-proliferative properties in HT-29 cells even after IGF-1 exposure by arresting G0/G1-S phase cell cycle progression through p27 stimulation and cyclin D1 suppression. Treatment with resveratrol suppressed IGF-1R protein levels and concurrently attenuated the downstream Akt/Wnt signaling pathways that play a critical role in cell proliferation. Targeted suppression of IGF-1R using IGF-1R siRNA also affected these signaling pathways in a similar manner. Resveratrol treatment induced apoptosis by activating tumor suppressor p53 protein, whereas IGF-1R siRNA treatment did not affect apoptosis. Our data suggests that resveratrol not only suppresses cell proliferation by inhibiting IGF-1R and its downstream signaling pathways similar to that of IGF-1R siRNA but also enhances apoptosis via activation of the p53 pathway. Conclusions For the first time, we report that resveratrol suppresses colon cancer cell proliferation and elevates apoptosis even in the presence of IGF-1 via suppression of IGF-1R/Akt/Wnt signaling pathways and

  15. Resveratrol suppresses IGF-1 induced human colon cancer cell proliferation and elevates apoptosis via suppression of IGF-1R/Wnt and activation of p53 signaling pathways

    International Nuclear Information System (INIS)

    Vanamala, Jairam; Reddivari, Lavanya; Radhakrishnan, Sridhar; Tarver, Chris

    2010-01-01

    Obesity is a global phenomenon and is associated with various types of cancer, including colon cancer. There is a growing interest for safe and effective bioactive compounds that suppress the risk for obesity-promoted colon cancer. Resveratrol (trans-3, 4', 5,-trihydroxystilbene), a stilbenoid found in the skin of red grapes and peanuts suppresses many types of cancers by regulating cell proliferation and apoptosis through a variety of mechanisms, however, resveratrol effects on obesity-promoted colon cancer are not clearly established. We investigated the anti-proliferative effects of resveratrol on HT-29 and SW480 human colon cancer cells in the presence and absence of insulin like growth factor-1 (IGF-1; elevated during obesity) and elucidated the mechanisms of action using IGF-1R siRNA in HT-29 cells which represents advanced colon carcinogenesis. Resveratrol (100-150 μM) exhibited anti-proliferative properties in HT-29 cells even after IGF-1 exposure by arresting G 0 /G 1 -S phase cell cycle progression through p27 stimulation and cyclin D1 suppression. Treatment with resveratrol suppressed IGF-1R protein levels and concurrently attenuated the downstream Akt/Wnt signaling pathways that play a critical role in cell proliferation. Targeted suppression of IGF-1R using IGF-1R siRNA also affected these signaling pathways in a similar manner. Resveratrol treatment induced apoptosis by activating tumor suppressor p53 protein, whereas IGF-1R siRNA treatment did not affect apoptosis. Our data suggests that resveratrol not only suppresses cell proliferation by inhibiting IGF-1R and its downstream signaling pathways similar to that of IGF-1R siRNA but also enhances apoptosis via activation of the p53 pathway. For the first time, we report that resveratrol suppresses colon cancer cell proliferation and elevates apoptosis even in the presence of IGF-1 via suppression of IGF-1R/Akt/Wnt signaling pathways and activation of p53, suggesting its potential role as a

  16. Spironolactone induces apoptosis in human mononuclear cells. Association between apoptosis and cytokine suppression

    DEFF Research Database (Denmark)

    Mikkelsen, Martin; Sønder, S U; Nersting, J

    2006-01-01

    Spironolactone (SPIR) has been described to suppress accumulation of pro-inflammatory cytokines. Here, the suppression of TNF-alpha in lipopolysaccharide (LPS)-stimulated mononuclear cell cultures was confirmed. However, SPIR was also found to induce apoptosis, prompting the investigations...... of a possible association between the two effects: The apoptosis-inducing and the cytokine-suppressive effects of SPIR correlated with regard to the effective concentration range. Also, pre-incubation experiments demonstrated a temporal separation of the two effects of ... preceding apoptosis. An association between the two effects was also seen when testing several SPIR analogues. Contrary to TNF-alpha, the levels of IL-1beta increased in SPIR-treated cultures. However, the amount of IL-1beta in the supernatants depended upon the order of SPIR and LPS addition, as IL-1beta...

  17. Dihydroavenanthramide D inhibits human breast cancer cell invasion through suppression of MMP-9 expression

    International Nuclear Information System (INIS)

    Lee, Young-Rae; Noh, Eun-Mi; Oh, Hyun Ju; Hur, Hyun; Kim, Jeong-Mi; Han, Ji-Hey; Hwang, Jin-Ki; Park, Byung-Hyun; Park, Jin-Woo; Youn, Hyun Jo; Jung, Sung Hoo; Kim, Byeong-Soo; Jung, Ji-Youn; Lee, Sung-Ho; Park, Chang-Sik; Kim, Jong-Suk

    2011-01-01

    Research highlights: → MMP-9 plays a pivotal role in the invasion of MCF-7 breast cancer cells. → TPA stimulates MMP-9 expression through activation of MAPK/NF-κB and MAPK/AP-1 pathways. → Dihydroavenanthramide D suppresses MMP-9 expression via inhibition of TPA-induced MAPK/NF-κB and MAPK/AP-1 activations. → Dihydroavenanthramide D blocks cell invasion of MCF-7 breast cancer cells. -- Abstract: Dihydroavenanthramide D (DHAvD) is a synthetic analog to naturally occurring avenanthramide, which is the active component of oat. Previous study demonstrates that DHAvD strongly inhibits activation of nuclear factor-kappa B (NF-κB), which is a major component in cancer cell invasion. The present study investigated whether DHAvD can modulate MMP-9 expression and cell invasion in MCF-7 human breast cancer cells. MMP-9 expression and cell invasion in response to 12-O-tetradecanoylphorbol-13-acetate (TPA) was increased, whereas these inductions were muted by DHAvD. DHAvD also suppressed activation of mitogen-activated protein kinase (MAPK), and MAPK-mediated nuclear factor-kappa B (NF-κB) and activator protein-1 (AP-1) activations in TPA-treated MCF-7 cells. The results indicate that DHAvD-mediated inhibition of TPA-induced MMP-9 expression and cell invasion involves the suppression of the MAPK/NF-κB and MAPK/AP-1 pathways in MCF-7 cells. DHAvD may have potential value in breast cancer metastasis.

  18. Fibulin-1 suppression of fibronectin-regulated cell adhesion and motility.

    Science.gov (United States)

    Twal, W O; Czirok, A; Hegedus, B; Knaak, C; Chintalapudi, M R; Okagawa, H; Sugi, Y; Argraves, W S

    2001-12-01

    Fibulin-1 is an extracellular matrix protein often associated with fibronectin (FN) in vivo. In this study, the ability of fibulin-1 to modulate adhesion, spreading and motility-promoting activities of FN was investigated. Fibulin-1 was found to have pronounced inhibitory effects on the cell attachment and spreading promoted by FN. Fibulin-1 was also found to inhibit the motility of a variety of cell types on FN substrata. For example, the FN-dependent haptotactic motility of breast carcinoma (MDA MB231) cells, epidermal carcinoma (A431), melanoma (A375 SM), rat pulmonary aortic smooth muscle cells (PAC1) and Chinese hamster ovary (CHO) cells was inhibited by the presence of fibulin-1 bound to FN-coated Boyden chamber membranes. Cells transfected to overproduce fibulin-1 displayed reduced velocity, distance of movement and persistence time on FN substrata. Similarly, the incorporation of fibulin-1 into FN-containing type I collagen gels inhibited the invasion of endocardial cushion mesenchymal cells migrating from cultured embryonic heart explants. By contrast, incorporation of fibulin-1 into collagen gels lacking FN had no effect on the migration of endocardial cushion cells. These results suggest that the motility-suppressive effects of fibulin-1 might be FN specific. Furthermore, such effects are cell-type specific, in that the migration of gingival fibroblasts and endothelial cells on FN substrata is not responsive to fibulin-1. Additional studies found that the mechanism for the motility-suppressive effects of fibulin-1 does not involve perturbations of interactions between alpha5beta1 or alpha4 integrins, or heparan sulfate proteoglycans with FN. However, fibulin-1 was found to inhibit extracellular signal regulated kinase (ERK) activation and to suppress phosphorylation of myosin heavy chain. This ability to influence signal transduction cascades that modulate the actin-myosin motor complex might be the basis for the effects of fibulin-1 on adhesion and

  19. Butyrate suppresses murine mast cell proliferation and cytokine production through inhibiting histone deacetylase.

    Science.gov (United States)

    Zhang, Hanying; Du, Min; Yang, Qiyuan; Zhu, Mei-Jun

    2016-01-01

    Beyond their nutritional impact to colonic epithelial cells, the intestinal microbiota metabolite butyrate has pleotropic effects to host cells and is known for its beneficial effects on intestinal homeostasis and metabolism. However, it remains unclear how it modulates mast cell function. Here, we demonstrate that butyrate profoundly inhibited proliferation of mouse mastocytoma P815 cells through inducing cell cycle arrest and apoptosis, as well as decreasing c-Kit activation. In addition, butyrate increased early- and late-stage apoptotic P815 cells. In murine bone marrow-derived mast cells (BMMC), butyrate-suppressed FcεRI-dependent tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6) release without affecting β-Hexosaminidase, but that was associated with decreased mitogen-activated protein kinase extracellular signal-regulated kinase 1/2, p38 and c-Jun N-terminal kinases activation. Butyrate treatment substantially enhanced histone 3 acetylation in both P815 and BMMC and decreased FcεRI-dependent mRNA expression of tnf-α and il-6 in BMMC, mimicking the effect of Trichostatin A, a known histone deacetylase inhibitor. Chromatin immunoprecipitation revealed that butyrate enhanced acetylation of the tnf-α and il-6 promoter regions but blocked RNA polymerase II binding to the promoters of tnf-α and il-6 genes, indicating suppressed transcription initiation. These phenotypes mimicked those of Trichostatin A treatment. In conclusion, butyrate inhibits cell proliferation and increases cell apoptosis in mastocytoma P815 cells and suppresses FcεRI-dependent cytokine production in murine primary BMMC, which are likely mediated by HDAC inhibition. Published by Elsevier Inc.

  20. Let-7b-mediated suppression of basigin expression and metastasis in mouse melanoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Tzu-Yen [Department of Animal Science, National Chung Hsing University, 250 Kuo Kuang Road, Taichung 40227, Taiwan (China); Chang, Chia-Che [Institute of Biomedical Sciences, National Chung Hsing University, 250 Kuo Kuang Road, Taichung 40227, Taiwan (China); Graduate Institute of Basic Medical Science, China Medical University, 91 Hsueh Shih Road, Taichung 40402, Taiwan (China); Lin, Chun-Ting [Department of Animal Science, National Chung Hsing University, 250 Kuo Kuang Road, Taichung 40227, Taiwan (China); Lai, Cong-Hao [Institute of Biomedical Sciences, National Chung Hsing University, 250 Kuo Kuang Road, Taichung 40227, Taiwan (China); Department of Life Sciences, National Chung Hsing University, 250 Kuo Kuang Road, Taichung 40227, Taiwan (China); Peng, Shao-Yu; Ko, Yi-Ju [Department of Animal Science, National Chung Hsing University, 250 Kuo Kuang Road, Taichung 40227, Taiwan (China); Tang, Pin-Chi, E-mail: pctang@dragon.nchu.edu.tw [Department of Animal Science, National Chung Hsing University, 250 Kuo Kuang Road, Taichung 40227, Taiwan (China)

    2011-02-15

    Basigin (Bsg), also called extracellular matrix metalloproteinase inducer (EMMPRIN), is highly expressed on the surface of tumor cells and stimulates adjacent fibroblasts or tumor cells to produce matrix metalloproteinases (mmps). It has been shown that Bsg plays an important role in growth, development, cell differentiation, and tumor progression. MicroRNAs (miRNAs) are a class of short endogenous non-protein coding RNAs of 20-25 nucleotides (nt) that function as post-transcriptional regulators of gene expression by base-pairing to their target mRNAs and thereby mediate cleavage of target mRNAs or translational repression. In this study, let-7b, one of the let-7 family members, was investigated for its effect on the growth and invasiveness of the mouse melanoma cell line B16-F10. We have shown that let-7b can suppress the expression of Bsg in B16-F10 cells and also provided evidence that this suppression could result in the indirect suppression of mmp-9. The ability of B16-F10 cells transfected with let-7b to invade or migrate was significantly reduced. In addition, let-7b transfected B16-F10 cells displayed an inhibition of both cellular proliferation and colony formation. Furthermore, it was shown that the overexpression of let-7b in B16-F10 cells could reduce lung metastasis. Taken together, the present study identifies let-7b as a tumor suppressor that represses cancer cell proliferation and migration as well as tumor metastasis in mouse melanoma cells.

  1. Protective effects of the extracts of Barringtonia racemosa shoots against oxidative damage in HepG2 cells

    Directory of Open Access Journals (Sweden)

    Kin Weng Kong

    2016-01-01

    Full Text Available Barringtonia racemosa is a tropical plant with medicinal values. In this study, the ability of the water extracts of the leaf (BLE and stem (BSE from the shoots to protect HepG2 cells against oxidative damage was studied. Five major polyphenolic compounds consisting of gallic acid, ellagic acid, protocatechuic acid, quercetin and kaempferol were identified using HPLC-DAD and ESI-MS. Cell viability assay revealed that BLE and BSE were non-cytotoxic (cell viabilities >80% at concentration less than 250 µg/ml and 500 µg/ml, respectively. BLE and BSE improved cellular antioxidant status measured by FRAP assay and protected HepG2 cells against H2O2-induced cytotoxicity. The extracts also inhibited lipid peroxidation in HepG2 cells as well as the production of reactive oxygen species. BLE and BSE could also suppress the activities of superoxide dismutase and catalase during oxidative stress. The shoots of B. racemosa can be an alternative bioactive ingredient in the prevention of oxidative damage.

  2. Mechanisms of CD8+ T cell-mediated suppression of HIV/SIV replication.

    Science.gov (United States)

    McBrien, Julia Bergild; Kumar, Nitasha A; Silvestri, Guido

    2018-02-10

    In this article, we summarize the role of CD8 + T cells during natural and antiretroviral therapy (ART)-treated HIV and SIV infections, discuss the mechanisms responsible for their suppressive activity, and review the rationale for CD8 + T cell-based HIV cure strategies. Evidence suggests that CD8 + T cells are involved in the control of virus replication during HIV and SIV infections. During early HIV infection, the cytolytic activity of CD8 + T cells is responsible for control of viremia. However, it has been proposed that CD8 + T cells also use non-cytolytic mechanisms to control SIV infection. More recently, CD8 + T cells were shown to be required to fully suppress virus production in ART-treated SIV-infected macaques, suggesting that CD8 + T cells are involved in the control of virus transcription in latently infected cells that persist under ART. A better understanding of the complex antiviral activities of CD8 + T cells during HIV/SIV infection will pave the way for immune interventions aimed at harnessing these functions to target the HIV reservoir. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Extracellular acidification by lactic acid suppresses glucose deprivation-induced cell death and autophagy in B16 melanoma cells.

    Science.gov (United States)

    Matsuo, Taisuke; Sadzuka, Yasuyuki

    2018-02-19

    In solid tumors, cancer cells survive and proliferate under conditions of microenvironment stress such as poor nutrients and hypoxia due to inadequate vascularization. These stress conditions in turn activate autophagy, which is important for cancer cell survival. However, autophagy has a contrary effect of inducing cell death in cancer cells cultured in vitro under conditions of glucose deprivation. In this study, we hypothesized that supplementation of lactic acid serves as a means of cell survival under glucose-deprived conditions. At neutral pH, cell death of B16 murine melanoma cells by autophagy under glucose-deprived conditions was observed. However, supplementation of lactic acid suppressed cell death and autophagy in B16 melanoma cells when cultured in glucose-deprived conditions. Sodium lactate, which does not change extracellular pH, did not inhibit cell death, while HCl-adjusted acidic pH suppressed cell death under glucose-deprived conditions. These results suggested that an acidic pH is crucial for cell survival under glucose-deprived conditions. Copyright © 2018 Elsevier Inc. All rights reserved.

  4. Trichostatin A Promotes the Generation and Suppressive Functions of Regulatory T Cells

    Directory of Open Access Journals (Sweden)

    Cristian Doñas

    2013-01-01

    Full Text Available Regulatory T cells are a specific subset of lymphocytes that suppress immune responses and play a crucial role in the maintenance of self-tolerance. They can be generated in the thymus as well as in the periphery through differentiation of naïve CD4+ T cells. The forkhead box P3 transcription factor (Foxp3 is a crucial molecule regulating the generation and function of Tregs. Here we show that the foxp3 gene promoter becomes hyperacetylated in in vitro differentiated Tregs compared to naïve CD4+ T cells. We also show that the histone deacetylase inhibitor TSA stimulated the in vitro differentiation of naïve CD4+ T cells into Tregs and that this induction was accompanied by a global increase in histone H3 acetylation. Importantly, we also demonstrated that Tregs generated in the presence of TSA have phenotypical and functional differences from the Tregs generated in the absence of TSA. Thus, TSA-generated Tregs showed increased suppressive activities, which could potentially be explained by a mechanism involving the ectonucleotidases CD39 and CD73. Our data show that TSA could potentially be used to enhance the differentiation and suppressive function of CD4+Foxp3+ Treg cells.

  5. Notch signaling is significantly suppressed in basal cell carcinomas and activation induces basal cell carcinoma cell apoptosis.

    Science.gov (United States)

    Shi, Feng-Tao; Yu, Mei; Zloty, David; Bell, Robert H; Wang, Eddy; Akhoundsadegh, Noushin; Leung, Gigi; Haegert, Anne; Carr, Nicholas; Shapiro, Jerry; McElwee, Kevin J

    2017-04-01

    A subset of basal cell carcinomas (BCCs) are directly derived from hair follicles (HFs). In some respects, HFs can be defined as 'ordered' skin appendage growths, while BCCs can be regarded as 'disordered' skin appendage growths. The aim of the present study was to examine HFs and BCCs to define the expression of common and unique signaling pathways in each skin appendage. Human nodular BCCs, along with HFs and non‑follicular skin epithelium from normal individuals, were examined using microarrays, qPCR, and immunohistochemistry. Subsequently, BCC cells and root sheath keratinocyte cells from HFs were cultured and treated with Notch signaling peptide Jagged1 (JAG1). Gene expression, protein levels, and cell apoptosis susceptibility were assessed using qPCR, immunoblotting, and flow cytometry, respectively. Specific molecular mechanisms were found to be involved in the process of cell self‑renewal in the HFs and BCCs, including Notch and Hedgehog signaling pathways. However, several key Notch signaling factors showed significant differential expression in BCCs compared with HFs. Stimulating Notch signaling with JAG1 induced apoptosis of BCC cells by increasing Fas ligand expression and downstream caspase-8 activation. The present study showed that Notch signaling pathway activity is suppressed in BCCs, and is highly expressed in HFs. Elements of the Notch pathway could, therefore, represent targets for the treatment of BCCs and potentially in hair follicle engineering.

  6. Protective effect of Nigella sativa and thymoquinone on serum/glucose deprivation-induced DNA damage in PC12 cells

    Directory of Open Access Journals (Sweden)

    Beheshteh Babazadeh

    2012-06-01

    Full Text Available Objective: The discovery and development of natural products with potent antioxidant properties has been one of the most interesting and promising approaches in the search for treatment of CNS injuries. The most significant consequence of the oxidative stress is thought to be the DNA modifications, which can become permanent via the formation of mutations and other types of genomic instability resulting cellular dysfunction. Serum/glucose deprivation (SGD has served as an excellent in vitro model for the understanding of the molecular mechanisms of neuronal damage during ischemia and for the development of neuroprotective drugs against ischemia-induced brain injury. Nigella sativa (N. sativa seeds and thymoquinone (TQ, its most abundant constituent, have been shown to possess anti-inflammatory, antioxidant, chemopreventive and anti-neoplastic effects both in vitro and in vivo. Therefore, in this study we investigated genoprotective effects of N. sativa and TQ on DNA damage of PC12 cells under SGD condition. Materials and Methods: PC12 cells were cultured in DMEM medium containing 10% (v/v fetal bovine serum, 100 units/ml penicillin, and 100 µg/ml streptomycin. Initially cells were pretreated with different concentrations of N. sativa extract (NSE, (10, 50, 250 µg/ml and TQ (1, 5, 10 µg/ml for 6 h and then deprived of serum/glucose (SGD for 18 h. The alkaline comet assay was used to evaluate the effect of these compounds on DNA damage following ischemic insult. The amount of DNA in the comet tail (% tail DNA was measured as an indicator of DNA damage. Results: A significant increase in the % tail DNA was seen in nuclei of cells following SGD induced DNA damage (p0.05. NSE and TQ pretreatment resulted in a significant decrease in DNA damage following ischemic insult (p<0.001. This suppression of DNA damage by NSE and TQ was found to be dose-dependent.Conclusion: These data indicate that NSE and TQ have a genoprotective property, as revealed by

  7. Immune Suppressive Effects of Tonsil-Derived Mesenchymal Stem Cells on Mouse Bone-Marrow-Derived Dendritic Cells

    Directory of Open Access Journals (Sweden)

    Minhwa Park

    2015-01-01

    Full Text Available Mesenchymal stem cells (MSCs are considered valuable sources for cell therapy because of their immune regulatory function. Here, we investigated the effects of tonsil-derived MSCs (T-MSCs on the differentiation, maturation, and function of dendritic cells (DCs. We examined the effect of T-MSCs on differentiation and maturation of bone-marrow- (BM- derived monocytes into DCs and we found suppressive effect of T-MSCs on DCs via direct contact as well as soluble mediators. Moreover, T cell proliferation, normally increased in the presence of DCs, was inhibited by T-MSCs. Differentiation of CD4+ T cell subsets by the DC-T cell interaction also was inhibited by T-MSCs. The soluble mediators suppressed by T-MSCs were granulocyte-macrophage colony-stimulating factor (GM-CSF, RANTES, interleukin-6 (IL-6, and monocyte chemoattractant protein-1 (MCP-1. Taken together, T-MSCs exert immune modulatory function via suppression of the differentiation, maturation, and function of BM-derived DCs. Our data suggests that T-MSCs could be used as a novel source of stem cell therapy as immune modulators.

  8. Silencing of poly(ADP-ribose) glycohydrolase sensitizes lung cancer cells to radiation through the abrogation of DNA damage checkpoint

    Energy Technology Data Exchange (ETDEWEB)

    Nakadate, Yusuke [Shien-Lab, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan); Department of Bioengineering, Graduate School of Engineering, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585 (Japan); Kodera, Yasuo; Kitamura, Yuka [Shien-Lab, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan); Tachibana, Taro [Department of Bioengineering, Graduate School of Engineering, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585 (Japan); Tamura, Tomohide [Division of Thoracic Oncology, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan); Koizumi, Fumiaki, E-mail: fkoizumi@ncc.go.jp [Division of Thoracic Oncology, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan)

    2013-11-29

    Highlights: •Radiosensitization by PARG silencing was observed in multiple lung cancer cells. •PAR accumulation was enhanced by PARG silencing after DNA damage. •Radiation-induced G2/M arrest and checkpoint activation were impaired by PARG siRNA. -- Abstract: Poly(ADP-ribose) glycohydrolase (PARG) is a major enzyme that plays a role in the degradation of poly(ADP-ribose) (PAR). PARG deficiency reportedly sensitizes cells to the effects of radiation. In lung cancer, however, it has not been fully elucidated. Here, we investigated whether PARG siRNA contributes to an increased radiosensitivity using 8 lung cancer cell lines. Among them, the silencing of PARG induced a radiosensitizing effect in 5 cell lines. Radiation-induced G2/M arrest was largely suppressed by PARG siRNA in PC-14 and A427 cells, which exhibited significantly enhanced radiosensitivity in response to PARG knockdown. On the other hand, a similar effect was not observed in H520 cells, which did not exhibit a radiosensitizing effect. Consistent with a cell cycle analysis, radiation-induced checkpoint signals were not well activated in the PC-14 and A427 cells when treated with PARG siRNA. These results suggest that the increased sensitivity to radiation induced by PARG knockdown occurs through the abrogation of radiation-induced G2/M arrest and checkpoint activation in lung cancer cells. Our findings indicate that PARG could be a potential target for lung cancer treatments when used in combination with radiotherapy.

  9. Thymidine selectively enhances growth suppressive effects of camptothecin/irinotecan in MSI+ cells and tumors containing a mutation of MRE11

    DEFF Research Database (Denmark)

    Rodriguez, Rene; Hansen, Lasse Tengbjerg; Phear, Geraldine

    2008-01-01

    PURPOSE: DNA synthesis inhibitors and damaging agents are widely used in cancer therapy; however, sensitivity of tumors to such agents is highly variable. The response of tumor cells in culture to these agents is strongly influenced by the status of DNA damage response pathways. Here, we attempt...... is not a direct result of MMR, p53, or p21 status. However MMR-deficient cell lines containing an intronic frameshift mutation of MRE11 show greatest sensitivity to these agents. Increased sensitivity to this combination is also evident in vivo as thymidine enhances irinotecan-induced growth suppression of MMR......-deficient tumors carrying the MRE11 mutation in mouse xenografts. CONCLUSION: Irinotecan-thymidine combinations may be particularly effective when targeted to MSI+ tumors containing this readily detectable MRE11 mutation....

  10. Cell wall degrading enzyme induced rice innate immune responses are suppressed by the type 3 secretion system effectors XopN, XopQ, XopX and XopZ of Xanthomonas oryzae pv. oryzae.

    Directory of Open Access Journals (Sweden)

    Dipanwita Sinha

    Full Text Available Innate immune responses are induced in plants and animals through perception of Damage Associated Molecular Patterns. These immune responses are suppressed by pathogens during infection. A number of studies have focussed on identifying functions of plant pathogenic bacteria that are involved in suppression of Pathogen Associated Molecular Pattern induced immune responses. In comparison, there is very little information on functions used by plant pathogens to suppress Damage Associated Molecular Pattern induced immune responses. Xanthomonasoryzae pv. oryzae, a gram negative bacterial pathogen of rice, secretes hydrolytic enzymes such as LipA (Lipase/Esterase that damage rice cell walls and induce innate immune responses. Here, we show that Agrobacterium mediated transient transfer of the gene for XopN, a X. oryzae pv. oryzae type 3 secretion (T3S system effector, results in suppression of rice innate immune responses induced by LipA. A xopN (- mutant of X. oryzae pv. oryzae retains the ability to suppress these innate immune responses indicating the presence of other functionally redundant proteins. In transient transfer assays, we have assessed the ability of 15 other X. oryzae pv. oryzae T3S secreted effectors to suppress rice innate immune responses. Amongst these proteins, XopQ, XopX and XopZ are suppressors of LipA induced innate immune responses. A mutation in any one of the xopN, xopQ, xopX or xopZ genes causes partial virulence deficiency while a xopN (- xopX (- double mutant exhibits a greater virulence deficiency. A xopN (- xopQ (- xopX (- xopZ (- quadruple mutant of X. oryzae pv. oryzae induces callose deposition, an innate immune response, similar to a X. oryzae pv. oryzae T3S(- mutant in rice leaves. Overall, these results indicate that multiple T3S secreted proteins of X. oryzae pv. oryzae can suppress cell wall damage induced rice innate immune responses.

  11. A Human Trypanosome Suppresses CD8+ T Cell Priming by Dendritic Cells through the Induction of Immune Regulatory CD4+ Foxp3+ T Cells.

    Science.gov (United States)

    Ersching, Jonatan; Basso, Alexandre Salgado; Kalich, Vera Lucia Garcia; Bortoluci, Karina Ramalho; Rodrigues, Maurício M

    2016-06-01

    Although CD4+ Foxp3+ T cells are largely described in the regulation of CD4+ T cell responses, their role in the suppression of CD8+ T cell priming is much less clear. Because the induction of CD8+ T cells during experimental infection with Trypanosoma cruzi is remarkably delayed and suboptimal, we raised the hypothesis that this protozoan parasite actively induces the regulation of CD8+ T cell priming. Using an in vivo assay that eliminated multiple variables associated with antigen processing and dendritic cell activation, we found that injection of bone marrow-derived dendritic cells exposed to T. cruzi induced regulatory CD4+ Foxp3+ T cells that suppressed the priming of transgenic CD8+ T cells by peptide-loaded BMDC. This newly described suppressive effect on CD8+ T cell priming was independent of IL-10, but partially dependent on CTLA-4 and TGF-β. Accordingly, depletion of Foxp3+ cells in mice infected with T. cruzi enhanced the response of epitope-specific CD8+ T cells. Altogether, our data uncover a mechanism by which T. cruzi suppresses CD8+ T cell responses, an event related to the establishment of chronic infections.

  12. A Human Trypanosome Suppresses CD8+ T Cell Priming by Dendritic Cells through the Induction of Immune Regulatory CD4+ Foxp3+ T Cells

    Science.gov (United States)

    Ersching, Jonatan; Basso, Alexandre Salgado; Kalich, Vera Lucia Garcia; Bortoluci, Karina Ramalho

    2016-01-01

    Although CD4+ Foxp3+ T cells are largely described in the regulation of CD4+ T cell responses, their role in the suppression of CD8+ T cell priming is much less clear. Because the induction of CD8+ T cells during experimental infection with Trypanosoma cruzi is remarkably delayed and suboptimal, we raised the hypothesis that this protozoan parasite actively induces the regulation of CD8+ T cell priming. Using an in vivo assay that eliminated multiple variables associated with antigen processing and dendritic cell activation, we found that injection of bone marrow-derived dendritic cells exposed to T. cruzi induced regulatory CD4+ Foxp3+ T cells that suppressed the priming of transgenic CD8+ T cells by peptide-loaded BMDC. This newly described suppressive effect on CD8+ T cell priming was independent of IL-10, but partially dependent on CTLA-4 and TGF-β. Accordingly, depletion of Foxp3+ cells in mice infected with T. cruzi enhanced the response of epitope-specific CD8+ T cells. Altogether, our data uncover a mechanism by which T. cruzi suppresses CD8+ T cell responses, an event related to the establishment of chronic infections. PMID:27332899

  13. Antibacterial agent triclosan suppresses RBL-2H3 mast cell function

    International Nuclear Information System (INIS)

    Palmer, Rachel K.; Hutchinson, Lee M.; Burpee, Benjamin T.; Tupper, Emily J.; Pelletier, Jonathan H.; Kormendy, Zsolt; Hopke, Alex R.; Malay, Ethan T.; Evans, Brieana L.; Velez, Alejandro; Gosse, Julie A.

    2012-01-01

    Triclosan is a broad-spectrum antibacterial agent, which has been shown previously to alleviate human allergic skin disease. The purpose of this study was to investigate the hypothesis that the mechanism of this action of triclosan is, in part, due to effects on mast cell function. Mast cells play important roles in allergy, asthma, parasite defense, and carcinogenesis. In response to various stimuli, mast cells degranulate, releasing allergic mediators such as histamine. In order to investigate the potential anti-inflammatory effect of triclosan on mast cells, we monitored the level of degranulation in a mast cell model, rat basophilic leukemia cells, clone 2H3. Having functional homology to human mast cells, as well as a very well defined signaling pathway leading to degranulation, this cell line has been widely used to gain insight into mast-cell driven allergic disorders in humans. Using a fluorescent microplate assay, we determined that triclosan strongly dampened the release of granules from activated rat mast cells starting at 2 μM treatment, with dose-responsive suppression through 30 μM. These concentrations were found to be non-cytotoxic. The inhibition was found to persist when early signaling events (such as IgE receptor aggregation and tyrosine phosphorylation) were bypassed by using calcium ionophore stimulation, indicating that the target for triclosan in this pathway is likely downstream of the calcium signaling event. Triclosan also strongly suppressed F-actin remodeling and cell membrane ruffling, a physiological process that accompanies degranulation. Our finding that triclosan inhibits mast cell function may explain the clinical data mentioned above and supports the use of triclosan or a mechanistically similar compound as a topical treatment for allergic skin disease, such as eczema. -- Highlights: ►The effects of triclosan on mast cell function using a murine mast cell model. ►Triclosan strongly inhibits degranulation of mast cells.

  14. Antibacterial agent triclosan suppresses RBL-2H3 mast cell function

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, Rachel K., E-mail: rachel.palmer@maine.edu [Graduate School of Biomedical Sciences, University of Maine, Orono, ME 04469 (United States); Department of Molecular and Biomedical Sciences, University of Maine, Orono, ME 04469 (United States); Hutchinson, Lee M.; Burpee, Benjamin T.; Tupper, Emily J.; Pelletier, Jonathan H.; Kormendy, Zsolt; Hopke, Alex R.; Malay, Ethan T.; Evans, Brieana L.; Velez, Alejandro [Department of Molecular and Biomedical Sciences, University of Maine, Orono, ME 04469 (United States); Gosse, Julie A., E-mail: julie.gosse@umit.maine.edu [Graduate School of Biomedical Sciences, University of Maine, Orono, ME 04469 (United States); Department of Molecular and Biomedical Sciences, University of Maine, Orono, ME 04469 (United States)

    2012-01-01

    Triclosan is a broad-spectrum antibacterial agent, which has been shown previously to alleviate human allergic skin disease. The purpose of this study was to investigate the hypothesis that the mechanism of this action of triclosan is, in part, due to effects on mast cell function. Mast cells play important roles in allergy, asthma, parasite defense, and carcinogenesis. In response to various stimuli, mast cells degranulate, releasing allergic mediators such as histamine. In order to investigate the potential anti-inflammatory effect of triclosan on mast cells, we monitored the level of degranulation in a mast cell model, rat basophilic leukemia cells, clone 2H3. Having functional homology to human mast cells, as well as a very well defined signaling pathway leading to degranulation, this cell line has been widely used to gain insight into mast-cell driven allergic disorders in humans. Using a fluorescent microplate assay, we determined that triclosan strongly dampened the release of granules from activated rat mast cells starting at 2 μM treatment, with dose-responsive suppression through 30 μM. These concentrations were found to be non-cytotoxic. The inhibition was found to persist when early signaling events (such as IgE receptor aggregation and tyrosine phosphorylation) were bypassed by using calcium ionophore stimulation, indicating that the target for triclosan in this pathway is likely downstream of the calcium signaling event. Triclosan also strongly suppressed F-actin remodeling and cell membrane ruffling, a physiological process that accompanies degranulation. Our finding that triclosan inhibits mast cell function may explain the clinical data mentioned above and supports the use of triclosan or a mechanistically similar compound as a topical treatment for allergic skin disease, such as eczema. -- Highlights: ►The effects of triclosan on mast cell function using a murine mast cell model. ►Triclosan strongly inhibits degranulation of mast cells.

  15. Sperm fucosyltransferase-5 mediates spermatozoa-oviductal epithelial cell interaction to protect human spermatozoa from oxidative damage.

    Science.gov (United States)

    Huang, Venus Wenxin; Lee, Cheuk-Lun; Lee, Yin-Lau; Lam, Kevin K W; Ko, Jennifer K Y; Yeung, William S B; Ho, Pak-Chung; Chiu, Philip C N

    2015-06-01

    Oxidative damage by reactive oxygen species (ROS) is a major cause of sperm dysfunction. Excessive ROS generation reduces fertilization and enhances DNA damage of spermatozoa. Interaction between spermatozoa and oviductal epithelial cells improves the fertilizing ability of and reduces chromatin damage in spermatozoa. Our previous data showed that oviductal epithelial cell membrane proteins interact with the human spermatozoa and protect them from ROS-induced reduction in sperm motility, membrane integrity and DNA integrity. Sperm fucosyltransferase-5 (sFUT5) is a membrane carbohydrate-binding protein on human spermatozoa. In this study, we demonstrate for the first time that sFUT5 is involved in human spermatozoa-oviduct interaction and the beneficial effects of such interaction on the fertilizing ability of human spermatozoa. Anti-sFUT5 antibody-treated spermatozoa had reduced binding to oviductal membrane proteins. It is consistent with the result that affinity-purified sFUT5 is bound to the epithelial lining of human oviduct and to the immortalized human oviductal epithelial cell line, OE-E6/E7. Pretreatment of spermatozoa with anti-sFUT5 antibody and oviductal membrane proteins with sFUT5 suppressed the protective action of oviductal membrane proteins against ROS/cryopreservation-induced oxidative damage in spermatozoa. Asialofetuin, a reported sFUT5 substrate, can partly mimic the protective effect of oviductal epithelial cell membrane proteins on sperm motility, membrane and DNA integrity. The results enhance our understanding on the protective mechanism of oviduct on sperm functions. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-12-01

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

  17. The herbal medicine compound falcarindiol from Notopterygii Rhizoma suppresses dendritic cell maturation.

    Science.gov (United States)

    Mitsui, Seika; Torii, Kan; Fukui, Hajime; Tsujimura, Kunio; Maeda, Akira; Nose, Mitsuhiko; Nagatsu, Akito; Mizukami, Hajime; Morita, Akimichi

    2010-06-01

    Dendritic cells (DCs) are important for regulating the immune response. We report an herbal medicine compound called falcarindiol that affects DC function. Ethanol extracts of 99 crude drugs that are the main components of 210 traditional Japanese medicines (Kampo medicine) approved by the Ministry of Health, Labor and Welfare in Japan were prepared and screened using the murine epidermal-derived Langerhans cell line XS106. Notopterygii Rhizoma strongly suppressed major histocompatibility complex (MHC) class II expression in XS106 cells. Activity-guided fractionation led to the isolation and identification of falcarindiol as a principal active compound in Notopterygii Rhizoma. Falcarindiol (1-5 microM) dose-dependently suppressed MHC II expression in XS106 cells. Fresh-isolated bone marrow-derived DCs were examined for the production of MHC II, CD80, CD86, interleukin (IL)-12p70, and IL-10. Treatment of bone marrow-derived DCs with 5 muM falcarindiol significantly inhibited lipopolysaccharide-induced phenotype activation and cytokine secretion and inhibited MHC II expression by CD40 ligation, but not phorbol 12-myristate 13-acetate + ionomycin or IL-12. Falcarindiol inhibited DC maturation by blocking the canonical pathway of nuclear factor-kappaB and phosphorylated p38. Topical application of 0.002 and 0.01% falcarindiol before sensitization dose-dependently suppressed delayed-type hypersensitivity to ovalbumin (p Falcarindiol induces immunosuppressive effects in vitro and in vivo and might be a novel therapy for autoimmune or allergic diseases.

  18. Lipocalin-2 inhibits osteoclast formation by suppressing the proliferation and differentiation of osteoclast lineage cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun-Ju, E-mail: biohjk@knu.ac.kr [Department of Molecular Medicine, Cell and Matrix Research Institute, Clinical Trial Center, BK21 Plus KNU Biomedical Convergence Program, School of Medicine, Kyungpook National University, Daegu 700-422 (Korea, Republic of); Yoon, Hye-Jin [Department of Molecular Medicine, Cell and Matrix Research Institute, Clinical Trial Center, BK21 Plus KNU Biomedical Convergence Program, School of Medicine, Kyungpook National University, Daegu 700-422 (Korea, Republic of); Yoon, Kyung-Ae [Department of Orthopedic Surgery, Skeletal Diseases Genome Research Center, School of Medicine, Kyungpook National University, Daegu 700-422 (Korea, Republic of); Gwon, Mi-Ri; Jin Seong, Sook [Department of Molecular Medicine, Cell and Matrix Research Institute, Clinical Trial Center, BK21 Plus KNU Biomedical Convergence Program, School of Medicine, Kyungpook National University, Daegu 700-422 (Korea, Republic of); Suk, Kyoungho [Department of Pharmacology, School of Medicine, Kyungpook National University, Daegu 700-422 (Korea, Republic of); Kim, Shin-Yoon [Department of Orthopedic Surgery, Skeletal Diseases Genome Research Center, School of Medicine, Kyungpook National University, Daegu 700-422 (Korea, Republic of); Yoon, Young-Ran, E-mail: yry@knu.ac.kr [Department of Molecular Medicine, Cell and Matrix Research Institute, Clinical Trial Center, BK21 Plus KNU Biomedical Convergence Program, School of Medicine, Kyungpook National University, Daegu 700-422 (Korea, Republic of)

    2015-06-10

    Lipocalin-2 (LCN2) is a member of the lipocalin superfamily and plays a critical role in the regulation of various physiological processes, such as inflammation and obesity. In this study, we report that LCN2 negatively modulates the proliferation and differentiation of osteoclast precursors, resulting in impaired osteoclast formation. The overexpression of LCN2 in bone marrow-derived macrophages or the addition of recombinant LCN2 protein inhibits the formation of multinuclear osteoclasts. LCN2 suppresses macrophage colony-stimulating factor (M-CSF)-induced proliferation of osteoclast precursor cells without affecting their apoptotic cell death. Interestingly, LCN2 decreases the expression of the M-CSF receptor, c-Fms, and subsequently blocks its downstream signaling cascades. In addition, LCN2 inhibits RANKL-induced osteoclast differentiation and attenuates the expression of c-Fos and nuclear factor of activated T cells c1 (NFATc1), which are important modulators in osteoclastogenesis. Mechanistically, LCN2 inhibits NF-κB signaling pathways, as demonstrated by the suppression of IκBα phosphorylation, nuclear translocation of p65, and NF-κB transcriptional activity. Thus, LCN2 is an anti-osteoclastogenic molecule that exerts its effects by retarding the proliferation and differentiation of osteoclast lineage cells. - Highlights: • LCN2 expression is regulated during osteoclast development. • LCN2 suppresses M-CSF-mediated osteoclast precursor proliferation. • LCN2 inhibits RANKL-induced osteoclast differentiation.

  19. Suppression, subversion and escape: the role of regulatory T cells in cancer progression.

    Science.gov (United States)

    Oleinika, K; Nibbs, R J; Graham, G J; Fraser, A R

    2013-01-01

    Regulatory T cells (T(regs) ) are crucial in mediating immune homeostasis and promoting the establishment and maintenance of peripheral tolerance. However, in the context of cancer their role is more complex, and they are thought to contribute to the progress of many tumours. As cancer cells express both self- and tumour-associated antigens, T(regs) are key to dampening effector cell responses, and therefore represent one of the main obstacles to effective anti-tumour responses. Suppression mechanisms employed by T(regs) are thought to contribute significantly to the failure of current therapies that rely on induction or potentiation of anti-tumour responses. This review will focus on the current evidence supporting the central role of T(regs) in establishing tumour-specific tolerance and promoting cancer escape. We outline the mechanisms underlying their suppressive function and discuss the potential routes of T(regs) accumulation within the tumour, including enhanced recruitment, in-situ or local proliferation, and de-novo differentiation. In addition, we review some of the cancer treatment strategies that act, at least in part, to eliminate or interfere with the function of T(regs) . The role of T(regs) is being recognized increasingly in cancer, and controlling the function of these suppressive cells in the tumour microenvironment without compromising peripheral tolerance represents a significant challenge for cancer therapies. © 2012 British Society for Immunology.

  20. Vorinostat, a histone deacetylase inhibitor, suppresses dendritic cell function and ameliorates experimental autoimmune encephalomyelitis.

    Science.gov (United States)

    Ge, Zhenzhen; Da, Yurong; Xue, Zhenyi; Zhang, Kai; Zhuang, Hao; Peng, Meiyu; Li, Yan; Li, Wen; Simard, Alain; Hao, Junwei; Yao, Zhi; Zhang, Rongxin

    2013-03-01

    Vorinostat, a histone deacetylase inhibitor, has been used clinically as an anticancer drug and also has immunosuppressive properties. However, the underlying mechanisms of effects of vorinostat on central nervous system (CNS) inflammatory diseases remain incomplete. Here, this study investigates the effects of vorinostat on human CD14(+) monocyte-derived dendritic cells (DCs) and mouse immature DC in vitro. Furthermore, we explore the therapeutic effects and cellular mechanisms of vorinostat on animal model of multiple sclerosis, experimental autoimmune encephalomyelitis (EAE) in vivo. Our findings demonstrate that vorinostat inhibited human CD14(+) monocyte-derived DCs differentiation, maturation, endocytosis, and further inhibited mDCs' stimulation of allogeneic T-cell proliferation. In addition, vorinostat inhibited DC-directed Th1- (Type 1T helper) and Th17-polarizing cytokine production. Furthermore, vorinostat ameliorated Th1- and Th17-mediated EAE by reducing CNS inflammation and demyelination. What's more, Th1 and Th17 cell functions were suppressed in vorinostat-treated EAE mice. Finally, vorinostat suppressed expression of costimulatory molecules of DC in EAE mice. These suggest therapeutic effects of vorinostat on EAE which may by suppress DCs and DCs-mediated Th1 and Th17 cell functions. Our findings warrant further investigation in the potential of vorinostat for the treatment of human multiple sclerosis. Copyright © 2012. Published by Elsevier Inc.

  1. Frequency, suppressive capacity, recruitment and induction mechanisms of regulatory T cells in sinonasal squamous cell carcinoma and nasal inverted papilloma.

    Directory of Open Access Journals (Sweden)

    Hongfei Lou

    Full Text Available Sinonasal squamous cell carcinoma (SSCC and nasal inverted papilloma (NIP represent the predominant type of malignant and benign tumors in sinonasal tract, respectively. CD4+ CD25+ Foxp3+ natural regulatory T (Treg cells might play critical role(s in the suppression of anti-tumor immune response and thus shed light on tumor progression from benign to malignant.This study aimed to evaluate the frequency and suppressive capacity of Treg cells in SSCC compared to NIP and further to explore the underlying mechanisms.Frequencies of Treg, Th1 and Th2 cells were evaluated by flow cytometry in tissue homogenate and peripheral blood from 31 SSCC patients, 32 NIP patients and 35 normal controls. Treg cells were tested for regulatory function by co-culture with effector T cells. CCR4 and its ligands, CCL22 and CCL17, were analyzed by flow cytometry and Luminex, respectively. The chemoattractant properties of CCR4/CCL22 and CCR4/CCL17 for Treg cells were assessed using the Boyden chamber technique, to elucidate the potential mechanisms of Treg recruitment in tumor microenvironment. Treg cells induction via TGF-β was assessed with transwells after local CD4+ Foxp3+ T cells were assessed by immunohistochemistry and TGF-β concentration was measured by Luminex.Tumor-infiltrating Treg cells increased significantly from normal to NIP to SSCC (P ≤ 0.001 for normal vs. NIP and P = 0.004 for NIP vs. SSCC. Significantly elevated frequency and enhanced suppression capacity of circulating Treg cells in SSCC were detected compared to NIP and healthy controls, concomitant with Th1 decrease and Th2 increase. Apparently increased CCL22 attracted CCR4-expressing Treg cells to tumor microenvironment in SSCC, compared to NIP. SSCC produced significantly more TGF-β than NIP and thus possessed greater potential for Treg cell induction.Frequency and suppressive capacity of Treg cells enhanced with progression of malignancy from NIP to SSCC. Circulating Treg cells were

  2. Curcumin suppresses proliferation of colon cancer cells by targeting CDK2.

    Science.gov (United States)

    Lim, Tae-Gyu; Lee, Sung-Young; Huang, Zunnan; Lim, Do Young; Chen, Hanyong; Jung, Sung Keun; Bode, Ann M; Lee, Ki Won; Dong, Zigang

    2014-04-01

    Curcumin, the yellow pigment of turmeric found in Southeast Indian food, is one of the most popular phytochemicals for cancer prevention. Numerous reports have demonstrated modulation of multiple cellular signaling pathways by curcumin and its molecular targets in various cancer cell lines. To identify a new molecular target of curcumin, we used shape screening and reverse docking to screen the Protein Data Bank against curcumin. Cyclin-dependent kinase 2 (CDK2), a major cell-cycle protein, was identified as a potential molecular target of curcumin. Indeed, in vitro and ex vivo kinase assay data revealed a dramatic suppressive effect of curcumin on CDK2 kinase activity. Furthermore, curcumin induced G1 cell-cycle arrest, which is regulated by CDK2 in HCT116 cells. Although the expression levels of CDK2 and its regulatory subunit, cyclin E, were not changed, the phosphorylation of retinoblastoma (Rb), a well-known CDK2 substrate, was reduced by curcumin. Because curcumin induced cell-cycle arrest, we investigated the antiproliferative effect of curcumin on HCT116 colon cancer cells. In this experiment, curcumin suppressed HCT116 cell proliferation effectively. To determine whether CDK2 is a direct target of curcumin, CDK2 expression was knocked down in HCT116 cells. As expected, HCT116 sh-CDK2 cells exhibited G1 arrest and reduced proliferation. Because of the low levels of CDK2 in HCT116 sh-CDK2 cells, the effects of curcumin on G1 arrest and cell proliferation were not substantially relative to HCT116 sh-control cells. From these results, we identified CDK2 as a direct target of curcumin in colon cancer cells.

  3. Plant polyphenols effectively protect HaCaT cells from ultraviolet C-triggered necrosis and suppress inflammatory chemokine expression.

    Science.gov (United States)

    Pastore, Saveria; Potapovich, Alla; Kostyuk, Vladimir; Mariani, Valentina; Lulli, Daniela; De Luca, Chiara; Korkina, Liudmila

    2009-08-01

    Oxidative stress is a common response of epidermal cells to a variety of noxious stimuli such as ultraviolet (UV) radiation from solar light and proinflammatory cytokines from skin-infiltrating leukocytes. Here, we report that two types of plant-derived antioxidants, the phenylpropanoid glycoside verbascoside as well as the flavonoids rutin and quercetin possess protective effects against UVC-induced cell damage and proinflammatory activation. The molecules under investigation were effective against the loss of cell integrity associated with necrosis in doses consistent with their antioxidant activity, whereas they did not significantly oppose UVC-induced proliferation arrest and apoptosis. By contrast, only verbascoside effectively inhibited cytokine-induced release of proinflammatory mediators in a dose-dependent fashion. Verbascoside and its homologue teupolioside dramatically impaired NF-kappaB and AP-1 DNA binding activity. These results suggest that plant polyphenols with antioxidant properties have distinct mechanisms in the suppression of oxidative stress induced in keratinocytes by different stimuli. Verbascoside and teupolioside are hence of potential interest in the protection of the skin from both environmental and inflammatory insults.

  4. Promotion or suppression of experimental metastasis of B16 melanoma cells after oral administration of lapachol.

    Science.gov (United States)

    Maeda, Masayo; Murakami, Manabu; Takegami, Tsutomu; Ota, Takahide

    2008-06-01

    Lapachol [2-hydroxy-3-(3-methyl-2-butenyl)-1,4-naphthoquinone] is a vitamin K antagonist with antitumor activity. The effect of lapachol on the experimental metastasis of murine B16BL6 melanoma cells was examined. A single oral administration of a high toxic dose of lapachol (80-100 mg/kg) 6 h before iv injection of tumor cells drastically promoted metastasis. This promotion of metastasis was also observed in T-cell-deficient mice and NK-suppressed mice. In vitro treatment of B16BL6 cells with lapachol promoted metastasis only slightly, indicating that lapachol promotes metastasis primarily by affecting host factors other than T cells and NK cells. A single oral administration of warfarin, the most commonly used vitamin K antagonist, 6 h before iv injection of tumor cells also drastically promoted the metastasis of B16BL6 cells. The promotion of metastasis by lapachol and warfarin was almost completely suppressed by preadministration of vitamin K3, indicating that the promotion of metastasis by lapachol was derived from vitamin K antagonism. Six hours after oral administration of lapachol or warfarin, the protein C level was reduced maximally, without elongation of prothrombin time. These observations suggest that a high toxic dose of lapachol promotes metastasis by inducing a hypercoagulable state as a result of vitamin K-dependent pathway inhibition. On the other hand, serial oral administration of low non-toxic doses of lapachol (5-20 mg/kg) weakly but significantly suppressed metastasis by an unknown mechanism, suggesting the possible use of lapachol as an anti-metastatic agent.

  5. Promotion or suppression of experimental metastasis of B16 melanoma cells after oral administration of lapachol

    International Nuclear Information System (INIS)

    Maeda, Masayo; Murakami, Manabu; Takegami, Tsutomu; Ota, Takahide

    2008-01-01

    Lapachol [2-hydroxy-3-(3-methyl-2-butenyl)-1,4-naphthoquinone] is a vitamin K antagonist with antitumor activity. The effect of lapachol on the experimental metastasis of murine B16BL6 melanoma cells was examined. A single oral administration of a high toxic dose of lapachol (80-100 mg/kg) 6 h before iv injection of tumor cells drastically promoted metastasis. This promotion of metastasis was also observed in T-cell-deficient mice and NK-suppressed mice. In vitro treatment of B16BL6 cells with lapachol promoted metastasis only slightly, indicating that lapachol promotes metastasis primarily by affecting host factors other than T cells and NK cells. A single oral administration of warfarin, the most commonly used vitamin K antagonist, 6 h before iv injection of tumor cells also drastically promoted the metastasis of B16BL6 cells. The promotion of metastasis by lapachol and warfarin was almost completely suppressed by preadministration of vitamin K3, indicating that the promotion of metastasis by lapachol was derived from vitamin K antagonism. Six hours after oral administration of lapachol or warfarin, the protein C level was reduced maximally, without elongation of prothrombin time. These observations suggest that a high toxic dose of lapachol promotes metastasis by inducing a hypercoagulable state as a result of vitamin K-dependent pathway inhibition. On the other hand, serial oral administration of low non-toxic doses of lapachol (5-20 mg/kg) weakly but significantly suppressed metastasis by an unknown mechanism, suggesting the possible use of lapachol as an anti-metastatic agent

  6. [Protective effect of Astragalus polysaccharide on MRC-5 cells from oxidative damage induced by hydrogen peroxide].

    Science.gov (United States)

    Chen, Juexiao; Wang, Guifen; Li, Li; Zhang, Pengxia

    2015-08-01

    To investigate the effects of Astragalus polysaccharide (APS) on the expressions of apurinic/apyrimidinic endonuclease/redox factor-1 (APE/Ref-1) and thioredoxin (TRX) in MRC-5 human embryo lung fibroblasts induced by hydrogen peroxide (H2O2) and explore the mechanism of APS protecting MRC-5 cells from oxidative damage. The MRC-5 cells were randomly divided into groups: the normal control group, groups induced by H2O2 of different concentrations, groups treated with 200, 400, 800 mg/L APS. The inhibitory rate of cell proliferation in H2O2-induced MRC-5 cells was measured by MTT assay to make sure the successful establishment of oxidative damage model. With the optimal concentration of H2O2 and different concentrations of APS on MRC-5 cells, we determined the optimal concentrate of APS to prevent oxidative damage in MRC-5 cells. The level of 8-hydroxy-2'-deoxyguanosine (8-OHdG) was detected by immunofluorescence staining. The apoptotic cells were identified by flow cytometry (FCM). The mRNA and protein levels of APE/Ref-1 and TRX were respectively detected by reverse transcription PCR and Western blotting. H2O2 induced oxidative damage in MRC-5 cells in a concentration-dependent manner. We chose the oxidative damage model induced by 800 μmol/L H2O2 for 24 hours to further study the protective mechanism of APS. Compared with H2O2 control groups, 200 mg/L APS significantly increased the protein level of APE/Ref-1 and TRX, decreased the content of 8-OHdG and the apoptosis of MRC-5 cells, and improved dramatically the cell viability. H2O2 can induce oxidative damage in MRC-5 cells. APS can promote APE/Ref-1 and TRX expressions in the damaged MRC-5 cells to relieve the oxidative damage and inhibit cell apoptosis.

  7. Zinc protects HepG2 cells against the oxidative damage and DNA damage induced by ochratoxin A

    International Nuclear Information System (INIS)

    Zheng, Juanjuan; Zhang, Yu; Xu, Wentao; Luo, YunBo; Hao, Junran; Shen, Xiao Li; Yang, Xuan; Li, Xiaohong; Huang, Kunlun

    2013-01-01

    Oxidative stress and DNA damage are the most studied mechanisms by which ochratoxin A (OTA) induces its toxic effects, which include nephrotoxicity, hepatotoxicity, immunotoxicity and genotoxicity. Zinc, which is an essential trace element, is considered a potential antioxidant. The aim of this paper was to investigate whether zinc supplement could inhibit OTA-induced oxidative damage and DNA damage in HepG2 cells and the mechanism of inhibition. The results indicated that that exposure of OTA decreased the intracellular zinc concentration; zinc supplement significantly reduced the OTA-induced production of reactive oxygen species (ROS) and decrease in superoxide dismutase (SOD) activity but did not affect the OTA-induced decrease in the mitochondrial membrane potential (Δψ m ). Meanwhile, the addition of the zinc chelator N,N,N′,N′-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) strongly aggravated the OTA-induced oxidative damage. This study also demonstrated that zinc helped to maintain the integrity of DNA through the reduction of OTA-induced DNA strand breaks, 8-hydroxy-2′-deoxyguanosine (8-OHdG) formation and DNA hypomethylation. OTA increased the mRNA expression of metallothionein1-A (MT1A), metallothionein2-A (MT2A) and Cu/Zn superoxide dismutase (SOD1). Zinc supplement further enhanced the mRNA expression of MT1A and MT2A, but it had no effect on the mRNA expression of SOD1 and catalase (CAT). Zinc was for the first time proven to reduce the cytotoxicity of OTA through inhibiting the oxidative damage and DNA damage, and regulating the expression of zinc-associated genes. Thus, the addition of zinc can potentially be used to reduce the OTA toxicity of contaminated feeds. - Highlights: ► OTA decreased the intracellular zinc concentration. ► OTA induced the formation of 8-OHdG in HepG2 cells. ► It was testified for the first time that OTA induced DNA hypomethylation. ► Zinc protects against the oxidative damage and DNA damage induced by OTA in

  8. Zinc protects HepG2 cells against the oxidative damage and DNA damage induced by ochratoxin A

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Juanjuan; Zhang, Yu [Laboratory of Food Safety and Molecular Biology, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083 (China); Xu, Wentao, E-mail: xuwentaoboy@sina.com [Laboratory of Food Safety and Molecular Biology, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083 (China); The Supervision, Inspection and Testing Center of Genetically Modified Organisms, Ministry of Agriculture, Beijing 100083 (China); Luo, YunBo [Laboratory of Food Safety and Molecular Biology, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083 (China); The Supervision, Inspection and Testing Center of Genetically Modified Organisms, Ministry of Agriculture, Beijing 100083 (China); Hao, Junran [Laboratory of Food Safety and Molecular Biology, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083 (China); Shen, Xiao Li [The Supervision, Inspection and Testing Center of Genetically Modified Organisms, Ministry of Agriculture, Beijing 100083 (China); Yang, Xuan [Laboratory of Food Safety and Molecular Biology, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083 (China); Li, Xiaohong [The Supervision, Inspection and Testing Center of Genetically Modified Organisms, Ministry of Agriculture, Beijing 100083 (China); Huang, Kunlun, E-mail: hkl009@163.com [Laboratory of Food Safety and Molecular Biology, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083 (China); The Supervision, Inspection and Testing Center of Genetically Modified Organisms, Ministry of Agriculture, Beijing 100083 (China)

    2013-04-15

    Oxidative stress and DNA damage are the most studied mechanisms by which ochratoxin A (OTA) induces its toxic effects, which include nephrotoxicity, hepatotoxicity, immunotoxicity and genotoxicity. Zinc, which is an essential trace element, is considered a potential antioxidant. The aim of this paper was to investigate whether zinc supplement could inhibit OTA-induced oxidative damage and DNA damage in HepG2 cells and the mechanism of inhibition. The results indicated that that exposure of OTA decreased the intracellular zinc concentration; zinc supplement significantly reduced the OTA-induced production of reactive oxygen species (ROS) and decrease in superoxide dismutase (SOD) activity but did not affect the OTA-induced decrease in the mitochondrial membrane potential (Δψ{sub m}). Meanwhile, the addition of the zinc chelator N,N,N′,N′-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) strongly aggravated the OTA-induced oxidative damage. This study also demonstrated that zinc helped to maintain the integrity of DNA through the reduction of OTA-induced DNA strand breaks, 8-hydroxy-2′-deoxyguanosine (8-OHdG) formation and DNA hypomethylation. OTA increased the mRNA expression of metallothionein1-A (MT1A), metallothionein2-A (MT2A) and Cu/Zn superoxide dismutase (SOD1). Zinc supplement further enhanced the mRNA expression of MT1A and MT2A, but it had no effect on the mRNA expression of SOD1 and catalase (CAT). Zinc was for the first time proven to reduce the cytotoxicity of OTA through inhibiting the oxidative damage and DNA damage, and regulating the expression of zinc-associated genes. Thus, the addition of zinc can potentially be used to reduce the OTA toxicity of contaminated feeds. - Highlights: ► OTA decreased the intracellular zinc concentration. ► OTA induced the formation of 8-OHdG in HepG2 cells. ► It was testified for the first time that OTA induced DNA hypomethylation. ► Zinc protects against the oxidative damage and DNA damage induced by

  9. Suppression of Cpn10 increases mitochondrial fission and dysfunction in neuroblastoma cells.

    Directory of Open Access Journals (Sweden)

    So Jung Park

    Full Text Available To date, several regulatory proteins involved in mitochondrial dynamics have been identified. However, the precise mechanism coordinating these complex processes remains unclear. Mitochondrial chaperones regulate mitochondrial function and structure. Chaperonin 10 (Cpn10 interacts with heat shock protein 60 (HSP60 and functions as a co-chaperone. In this study, we found that down-regulation of Cpn10 highly promoted mitochondrial fragmentation in SK-N-MC and SH-SY5Y neuroblastoma cells. Both genetic and chemical inhibition of Drp1 suppressed the mitochondrial fragmentation induced by Cpn10 reduction. Reactive oxygen species (ROS generation in 3-NP-treated cells was markedly enhanced by Cpn10 knock down. Depletion of Cpn10 synergistically increased cell death in response to 3-NP treatment. Furthermore, inhibition of Drp1 recovered Cpn10-mediated mitochondrial dysfunction in 3-NP-treated cells. Moreover, an ROS scavenger suppressed cell death mediated by Cpn10 knockdown in 3-NP-treated cells. Taken together, these results showed that down-regulation of Cpn10 increased mitochondrial fragmentation and potentiated 3-NP-mediated mitochondrial dysfunction in neuroblastoma cells.

  10. Hydroxysafflor yellow A suppresses oxidized low density lipoprotein induced proliferation of vascular smooth muscle cells

    Directory of Open Access Journals (Sweden)

    Lin Sheng

    2012-06-01

    Full Text Available To investigate the relationship between the suppression of Hydroxysafflor yellow A (HSYA on the oxidized low density lipoprotein (ox-LDL induced proliferation of vascular smooth muscle cells (VSMCs and the mRNA and protein expression of extracellular signal-regulated protein kinase 1/2 (ERK1/2 and mitogen activated protein kinase phospholipase-1 (MAKP-1, VSMCs were treated with HSYA at 10 ?mol/L and/or ox-LDL at 35 mg/L for 48 h. MTT assay was done to measure cell survival rate, flow cytometry to detect cell cycle, reverse transcription PCR and Western blot to detect the expression of ERK1/2 and MAKP-1. When compared to cells treated with ox-LDL alone, the survival rate of cells treated with two reagents was reduced and the proportion of cells in G0/G1 phase significantly increased, with increased MKP-1 expression. The study suggests HSYA can inhibit VSMC proliferation via increasing MKP-1 expression, reducing p-ERK1/2 activity and suppressing cell cycle.

  11. Controlling kinase activity during the cell cycle: from the DNA damage response to mitosis

    NARCIS (Netherlands)

    Bruinsma, W.

    2014-01-01

    The cell cycle is the process through which cells execute cell division. This is essential for many basal processes such as organismal development, tissue maintenance and reproduction. Disruption of the cell cycle, for example by damaged DNA, can have vast consequences and can lead to many diseases

  12. Cell Survival and DNA Damage in Normal Prostate Cells Irradiated Out-of-Field.

    LENUS (Irish Health Repository)

    Shields, L

    2014-10-31

    Interest in out-of-field radiation dose has been increasing with the introduction of new techniques, such as volumetric modulated arc therapy (VMAT). These new techniques offer superior conformity of high-dose regions to the target compared to conventional techniques, however more normal tissue is exposed to low-dose radiation with VMAT. There is a potential increase in radiobiological effectiveness associated with lower energy photons delivered during VMAT as normal cells are exposed to a temporal change in incident photon energy spectrum. During VMAT deliveries, normal cells can be exposed to the primary radiation beam, as well as to transmission and scatter radiation. The impact of low-dose radiation, radiation-induced bystander effect and change in energy spectrum on normal cells are not well understood. The current study examined cell survival and DNA damage in normal prostate cells after exposure to out-of-field radiation both with and without the transfer of bystander factors. The effect of a change in energy spectrum out-of-field compared to in-field was also investigated. Prostate cancer (LNCaP) and normal prostate (PNT1A) cells were placed in-field and out-of-field, respectively, with the PNT1A cells being located 1 cm from the field edge when in-field cells were being irradiated with 2 Gy. Clonogenic and γ-H2AX assays were performed postirradiation to examine cell survival and DNA damage. The assays were repeated when bystander factors from the LNCaP cells were transferred to the PNT1A cells and also when the PNT1A cells were irradiated in-field to a different energy spectrum. An average out-of-field dose of 10.8 ± 4.2 cGy produced a significant reduction in colony volume and increase in the number of γ-H2AX foci\\/cell in the PNT1A cells compared to the sham-irradiated control cells. An adaptive response was observed in the PNT1A cells having first received a low out-of-field dose and then the bystander factors. The PNT1A cells showed a significant

  13. Fanconi anemia cells with unrepaired DNA damage activate components of the checkpoint recovery process.

    Science.gov (United States)

    Rodríguez, Alfredo; Torres, Leda; Juárez, Ulises; Sosa, David; Azpeitia, Eugenio; García-de Teresa, Benilde; Cortés, Edith; Ortíz, Rocío; Salazar, Ana M; Ostrosky-Wegman, Patricia; Mendoza, Luis; Frías, Sara

    2015-09-18

    The FA/BRCA pathway repairs DNA interstrand crosslinks. Mutations in this pathway cause Fanconi anemia (FA), a chromosome instability syndrome with bone marrow failure and cancer predisposition. Upon DNA damage, normal and FA cells inhibit the cell cycle progression, until the G2/M checkpoint is turned off by the checkpoint recovery, which becomes activated when the DNA damage has been repaired. Interestingly, highly damaged FA cells seem to override the G2/M checkpoint. In this study we explored with a Boolean network model and key experiments whether checkpoint recovery activation occurs in FA cells with extensive unrepaired DNA damage. We performed synchronous/asynchronous simulations of the FA/BRCA pathway Boolean network model. FA-A and normal lymphoblastoid cell lines were used to study checkpoint and checkpoint recovery activation after DNA damage induction. The experimental approach included flow cytometry cell cycle analysis, cell division tracking, chromosome aberration analysis and gene expression analysis through qRT-PCR and western blot. Computational simulations suggested that in FA mutants checkpoint recovery activity inhibits the checkpoint components despite unrepaired DNA damage, a behavior that we did not observed in wild-type simulations. This result implies that FA cells would eventually reenter the cell cycle after a DNA damage induced G2/M checkpoint arrest, but before the damage has been fixed. We observed that FA-A cells activate the G2/M checkpoint and arrest in G2 phase, but eventually reach mitosis and divide with unrepaired DNA damage, thus resolving the initial checkpoint arrest. Based on our model result we look for ectopic activity of checkpoint recovery components. We found that checkpoint recovery components, such as PLK1, are expressed to a similar extent as normal undamaged cells do, even though FA-A cells harbor highly damaged DNA. Our results show that FA cells, despite extensive DNA damage, do not loss the capacity to express

  14. Anti-S100A4 antibody suppresses metastasis formation by blocking stroma cell invasion

    DEFF Research Database (Denmark)

    Klingelhöfer, Jörg; Grum-Schwensen, Birgitte; Beck, Mette K

    2012-01-01

    microenvironment, making it an attractive target for anti-cancer therapy. In this study, we produced a function-blocking anti-S100A4 monoclonal antibody with metastasis-suppressing activity. Antibody treatment significantly reduced metastatic burden in the lungs of experimental animals by blocking the recruitment......The small Ca-binding protein, S100A4, has a well-established metastasis-promoting activity. Moreover, its expression is tightly correlated with poor prognosis in patients with numerous types of cancer. Mechanistically, the extracellular S100A4 drives metastasis by affecting the tumor...... of T cells to the site of the primary tumor. In vitro studies demonstrated that this antibody efficiently reduced the invasion of T cells in a fibroblast monolayer. Moreover, it was capable of suppressing the invasive growth of human and mouse fibroblasts. We presume therefore that the antibody exerts...

  15. New steroidal aromatase inhibitors: Suppression of estrogen-dependent breast cancer cell proliferation and induction of cell death

    Directory of Open Access Journals (Sweden)

    Roleira Fernanda MF

    2008-07-01

    Full Text Available Abstract Background Aromatase, the cytochrome P-450 enzyme (CYP19 responsible for estrogen biosynthesis, is an important target for the treatment of estrogen-dependent breast cancer. In fact, the use of synthetic aromatase inhibitors (AI, which induce suppression of estrogen synthesis, has shown to be an effective alternative to the classical tamoxifen for the treatment of postmenopausal patients with ER-positive breast cancer. New AIs obtained, in our laboratory, by modification of the A and D-rings of the natural substrate of aromatase, compounds 3a and 4a, showed previously to efficiently suppress aromatase activity in placental microsomes. In the present study we have investigated the effects of these compounds on cell proliferation, cell cycle progression and induction of cell death using the estrogen-dependent human breast cancer cell line stably transfected with the aromatase gene, MCF-7 aro cells. Results The new steroids inhibit hormone-dependent proliferation of MCF-7aro cells in a time and dose-dependent manner, causing cell cycle arrest in G0/G1 phase and inducing cell death with features of apoptosis and autophagic cell death. Conclusion Our in vitro studies showed that the two steroidal AIs, 3a and 4a, are potent inhibitors of breast cancer cell proliferation. Moreover, it was also shown that the antiproliferative effects of these two steroids on MCF-7aro cells are mediated by disrupting cell cycle progression, through cell cycle arrest in G0/G1 phase and induction of cell death, being the dominant mechanism autophagic cell death. Our results are important for the elucidation of the cellular effects of steroidal AIs on breast cancer.

  16. Cross-activating invariant NKT cells and kupffer cells suppress cholestatic liver injury in a mouse model of biliary obstruction.

    Directory of Open Access Journals (Sweden)

    Caroline C Duwaerts

    Full Text Available Both Kupffer cells and invariant natural killer T (iNKT cells suppress neutrophil-dependent liver injury in a mouse model of biliary obstruction. We hypothesize that these roles are interdependent and require iNKT cell-Kupffer cell cross-activation. Female, wild-type and iNKT cell-deficient C57Bl/6 mice were injected with magnetic beads 3 days prior to bile duct ligation (BDL in order to facilitate subsequent Kupffer cell isolation. On day three post-BDL, the animals were euthanized and the livers dissected. Necrosis was scored; Kupffer cells were isolated and cell surface marker expression (flow cytometry, mRNA expression (qtPCR, nitric oxide (NO (. production (Griess reaction, and protein secretion (cytometric bead-array or ELISAs were determined. To address the potential role of NO (. in suppressing neutrophil accumulation, a group of WT mice received 1400W, a specific inducible nitric oxide synthase (iNOS inhibitor, prior to BDL. To clarify the mechanisms underlying Kupffer cell-iNKT cell cross-activation, WT animals were administered anti-IFN-γ or anti-lymphocyte function-associated antigen (LFA-1 antibody prior to BDL. Compared to their WT counterparts, Kupffer cells obtained from BDL iNKT cell-deficient mice expressed lower iNOS mRNA levels, produced less NO (. , and secreted more neutrophil chemoattractants. Both iNOS inhibition and IFN-γ neutralization increased neutrophil accumulation in the livers of BDL WT mice. Anti-LFA-1 pre-treatment reduced iNKT cell accumulation in these same animals. These data indicate that the LFA-1-dependent cross-activation of iNKT cells and Kupffer cells inhibits neutrophil accumulation and cholestatic liver injury.

  17. Chemokine CXCL16 Expression Suppresses Migration and Invasiveness and Induces Apoptosis in Breast Cancer Cells

    Directory of Open Access Journals (Sweden)

    Yeying Fang

    2014-01-01

    Full Text Available Background. Increasing evidence argues that soluble CXCL16 promotes proliferation, migration, and invasion of cancer cells in vitro. However, the role of transmembrane or cellular CXCL16 in cancer remains relatively unknown. In this study, we determine the function of cellular CXCL16 as tumor suppressor in breast cancer cells. Methods. Expression of cellular CXCL16 in breast cancer cell lines was determined at both RNA and protein levels. In vitro and in vivo studies that overexpressed or downregulated CXCL16 were conducted in breast cancer cells. Results. We report differential expression of cellular CXCL16 in breast cancer cell lines that was negatively correlated with cell invasiveness and migration. Overexpression of CXCL16 in MDA-MB-231 cells led to a decrease in cell invasion and migration and induced apoptosis of the cells; downregulation of CXCL16 in MCF-7 cells increased cell migration and invasiveness. Consistent with the in vitro data, CXCL16 overexpression inhibited tumorigenesis in vivo. Conclusions. Cellular CXCL16 suppresses invasion and metastasis of breast cancer cells in vitro and inhibits tumorigenesis in vivo. Targeting of cellular CXCL16 expression is a potential therapeutic strategy for breast cancer.

  18. Overexpression of SAMD9 suppresses tumorigenesis and progression during non small cell lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Qing; Yu, Tao; Ren, Yao-Yao; Gong, Ting; Zhong, Dian-Sheng, E-mail: zhongdsyx@126.com

    2014-11-07

    Highlights: • SAMD9 is down-regulated in human non-small cell lung cancer (NSCLC). • Knockdown of SAMD9 expression is increased the invasion, migration and proliferation in H1299 cells in vitro. • Overexpression of SAMD9 suppressed proliferation and invasion in A549 cells in vitro. • Depletion of SAMD9 increases tumor formation in vivo. - Abstract: The Sterile Alpha Motif Domain-containing 9 (SAMD9) gene has been recently emphasized during the discovery that it is expressed at a lower level in aggressive fibromatosis and some cases of breast and colon cancer, however, the underlying mechanisms are poorly understood. Here, we found that SAMD9 is down-regulated in human non-small cell lung cancer (NSCLC). Furthermore, knockdown of SAMD9 expression is increased the invasion, migration and proliferation in H1299 cells in vitro and overexpression of SAMD9 suppressed proliferation and invasion in A549 cells. Finally, depletion of SAMD9 increases tumor formation in vivo. Our results may provide a strategy for blocking NSCLC tumorigenesis and progression.

  19. Aloe-emodin suppresses esophageal cancer cell TE1 proliferation by inhibiting AKT and ERK phosphorylation

    Science.gov (United States)

    Chang, Xiaobin; Zhao, Jimin; Tian, Fang; Jiang, Yanan; Lu, Jing; Ma, Junfen; Zhang, Xiaoyan; Jin, Guoguo; Huang, Youtian; Dong, Zigang; Liu, Kangdong; Dong, Ziming

    2016-01-01

    Aberrant AKT and extracellular signal-regulated kinase (ERK) activation is often observed in various human cancers. Both AKT and ERK are important in the phosphoinositide 3-kinase/AKT and mitogen-activated protein kinase kinase/ERK signaling pathways, which play vital roles in cell proliferation, differentiation and survival. Compounds that are able to block these pathways have therefore a promising use in cancer treatment and prevention. The present study revealed that AKT and ERK are activated in esophageal cancer TE1 cells. Aloe-emodin, an anthraquinone present in aloe latex, can suppress TE1 cell proliferation and anchor-independent cell growth. Aloe-emodin can also reduce the number of TE1 cells in S phase. Protein analysis indicated that aloe-emodin inhibits the phosphorylation of AKT and ERK in a dose-dependent manner. Overall, the present data indicate that aloe-emodin can suppress TE1 cell growth by inhibiting AKT and ERK phosphorylation, and suggest its clinical use for cancer therapy. PMID:27602169

  20. Cell to Cell Variability of Radiation-Induced Foci: Relation between Observed Damage and Energy Deposition.

    Science.gov (United States)

    Gruel, Gaëtan; Villagrasa, Carmen; Voisin, Pascale; Clairand, Isabelle; Benderitter, Marc; Bottollier-Depois, Jean-François; Barquinero, Joan Francesc

    2016-01-01

    Most studies that aim to understand the interactions between different types of photon radiation and cellular DNA assume homogeneous cell irradiation, with all cells receiving the same amount of energy. The level of DNA damage is therefore generally determined by averaging it over the entire population of exposed cells. However, evaluating the molecular consequences of a stochastic phenomenon such as energy deposition of ionizing radiation by measuring only an average effect may not be sufficient for understanding some aspects of the cellular response to this radiation. The variance among the cells associated with this average effect may also be important for the behaviour of irradiated tissue. In this study, we accurately estimated the distribution of the number of radiation-induced γH2AX foci (RIF) per cell nucleus in a large population of endothelial cells exposed to 3 macroscopic doses of gamma rays from 60Co. The number of RIF varied significantly and reproducibly from cell to cell, with its relative standard deviation ranging from 36% to 18% depending on the macroscopic dose delivered. Interestingly, this relative cell-to-cell variability increased as the dose decreased, contrary to the mean RIF count per cell. This result shows that the dose effect, in terms of the number of DNA lesions indicated by RIF is not as simple as a purely proportional relation in which relative SD is constant with dose. To analyse the origins of this observed variability, we calculated the spread of the specific energy distribution for the different target volumes and subvolumes in which RIF can be generated. Variances, standard deviations and relative standard deviations all changed similarly from dose to dose for biological and calculated microdosimetric values. This similarity is an important argument that supports the hypothesis of the conservation of the association between the number of RIF per nucleus and the specific energy per DNA molecule. This comparison allowed us to

  1. Cell to Cell Variability of Radiation-Induced Foci: Relation between Observed Damage and Energy Deposition.

    Directory of Open Access Journals (Sweden)

    Gaëtan Gruel

    Full Text Available Most studies that aim to understand the interactions between different types of photon radiation and cellular DNA assume homogeneous cell irradiation, with all cells receiving the same amount of energy. The level of DNA damage is therefore generally determined by averaging it over the entire population of exposed cells. However, evaluating the molecular consequences of a stochastic phenomenon such as energy deposition of ionizing radiation by measuring only an average effect may not be sufficient for understanding some aspects of the cellular response to this radiation. The variance among the cells associated with this average effect may also be important for the behaviour of irradiated tissue. In this study, we accurately estimated the distribution of the number of radiation-induced γH2AX foci (RIF per cell nucleus in a large population of endothelial cells exposed to 3 macroscopic doses of gamma rays from 60Co. The number of RIF varied significantly and reproducibly from cell to cell, with its relative standard deviation ranging from 36% to 18% depending on the macroscopic dose delivered. Interestingly, this relative cell-to-cell variability increased as the dose decreased, contrary to the mean RIF count per cell. This result shows that the dose effect, in terms of the number of DNA lesions indicated by RIF is not as simple as a purely proportional relation in which relative SD is constant with dose. To analyse the origins of this observed variability, we calculated the spread of the specific energy distribution for the different target volumes and subvolumes in which RIF can be generated. Variances, standard deviations and relative standard deviations all changed similarly from dose to dose for biological and calculated microdosimetric values. This similarity is an important argument that supports the hypothesis of the conservation of the association between the number of RIF per nucleus and the specific energy per DNA molecule. This

  2. Cell damage and dye reduction in the quantitative nitroblue tetrazolium (NBT) test.

    Science.gov (United States)

    Segal, A W; Levi, A J

    1975-01-01

    Nitroblue tetrazolium (NBT) is toxic to neutrophils; an effect which is greatly enhanced by endotoxin and latex particles. Cell damage, measured by the release of the cytoplasmic marker enzyme lactate dehydrogenase (LDH), was closely related to dye reduction. This suggests that, in this test, dye reduction occurs largely as a result of contact between intracellular reducing compounds and NBT following damage of the outer cell membrane. The expression of dye reduction as a function of LDH release should enhance the sensitivity of the quantitative NBT test by correcting for the observed intersubject variation in cell damage. The relationship between cell damage and dye reduction is a measure of the reducing capacity of the cell. This was normal in immature, bone marrow neutrophils, but diminished in neutrophils of patients with chronic granulomatous disease. Images Fig. 3 PMID:1212802

  3. The characterisation of selective proton damage on GaAs solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Aliyu, Y.H. (School of Electrical, Electronic and Systems Engineering, Wales Univ., Cardiff (United Kingdom)); Morgan, D.V. (School of Electrical, Electronic and Systems Engineering, Wales Univ., Cardiff (United Kingdom)); Bunce, R.W. (School of Electrical, Electronic and Systems Engineering, Wales Univ., Cardiff (United Kingdom))

    1993-01-16

    Selective ion bombardment damage was induced on n/n[sup +] GaAs Schottky barrier solar cell structure using several proton energies and doses. The damage in the surface, interface, and the bulk regions were characterised by I-V, C-V, and thermally stimulated current technique (TSC). A correlation between the selective damages and the nature of the defects and their location was obtained. (orig.)

  4. Knockdown of Pokemon protein expression inhibits hepatocellular carcinoma cell proliferation by suppression of AKT activity.

    Science.gov (United States)

    Zhu, Xiaosan; Dai, Yichen; Chen, Zhangxin; Xie, Junpei; Zeng, Wei; Lin, Yuanyuan

    2013-01-01

    Overexpression of Pokemon, which is an erythroid myeloid ontogenic factor protein, occurs in different cancers, including hepatocellular carcinoma (HCC). Pokemon is also reported to have an oncogenic activity in various human cancers. This study investigated the effect of Pokemon knockdown on the regulation of HCC growth. POK shRNA suppressed the expression of Pokemon protein in HepG2 cells compared to the negative control vector-transfected HCC cells. Pokemon knockdown also reduced HCC cell viability and enhanced cisplatin-induced apoptosis in HCC cells. AKT activation and the expression of various cell cycle-related genes were inhibited following Pokemon knockdown. These data demonstrate that Pokemon may play a role in HCC progression, suggesting that inhibition of Pokemon expression using Pokemon shRNA should be further evaluated as a novel target for the control of HCC.

  5. Control of immune ligands by members of a cytomegalovirus gene expansion suppresses natural killer cell activation.

    Science.gov (United States)

    Fielding, Ceri A; Weekes, Michael P; Nobre, Luis V; Ruckova, Eva; Wilkie, Gavin S; Paulo, Joao A; Chang, Chiwen; Suárez, Nicolás M; Davies, James A; Antrobus, Robin; Stanton, Richard J; Aicheler, Rebecca J; Nichols, Hester; Vojtesek, Borek; Trowsdale, John; Davison, Andrew J; Gygi, Steven P; Tomasec, Peter; Lehner, Paul J; Wilkinson, Gavin W G

    2017-02-10

    The human cytomegalovirus (HCMV) US12 family consists of ten sequentially arranged genes (US12-21) with poorly characterized function. We now identify novel natural killer (NK) cell evasion functions for four members: US12, US14, US18 and US20. Using a systematic multiplexed proteomics approach to quantify ~1300 cell surface and ~7200 whole cell proteins, we demonstrate that the US12 family selectively targets plasma membrane proteins and plays key roles in regulating NK ligands, adhesion molecules and cytokine receptors. US18 and US20 work in concert to suppress cell surface expression of the critical NKp30 ligand B7-H6 thus inhibiting NK cell activation. The US12 family is therefore identified as a major new hub of immune regulation.

  6. High Concentration of Melatonin Regulates Leaf Development by Suppressing Cell Proliferation and Endoreduplication in Arabidopsis.

    Science.gov (United States)

    Wang, Qiannan; An, Bang; Shi, Haitao; Luo, Hongli; He, Chaozu

    2017-05-05

    N -acetyl-5-methoxytryptamine (Melatonin), as a crucial messenger in plants, functions in adjusting biological rhythms, stress tolerance, plant growth and development. Several studies have shown the retardation effect of exogenous melatonin treatment on plant growth and development. However, the in vivo role of melatonin in regulating plant leaf growth and the underlying mechanism are still unclear. In this study, we found that high concentration of melatonin suppressed leaf growth in Arabidopsis by reducing both cell size and cell number. Further kinetic analysis of the fifth leaves showed that melatonin remarkably inhibited cell division rate. Additionally, flow cytometic analysis indicated that melatonin negatively regulated endoreduplication during leaf development. Consistently, the expression analysis revealed that melatonin regulated the transcriptional levels of key genes of cell cycle and ribosome. Taken together, this study suggests that high concentration of melatonin negatively regulated the leaf growth and development in Arabidopsis , through modulation of endoreduplication and the transcripts of cell cycle and ribosomal key genes.

  7. Red blood cell damage from extracorporeal circulation in hemodialysis.

    Science.gov (United States)

    Polaschegg, Hans-Dietrich

    2009-01-01

    Blood damage is an unavoidable side effect of extracorporeal circulation. The effects of blood damage on patients' hematocrit and erythropoietin requirement as well as other potential side effects have not been studied for uneventful treatments. Comparing long nocturnal dialysis with regular 4-hour, three times per week dialysis allows for the conclusion that the influence of blood damage caused by extracorporeal circulation is small compared with biochemical effects. Acute hemolysis is one of the few remaining mechanical problems of dialysis. Acute hemolysis is caused by obstructions within the extracorporeal circuit caused by manufacturing errors, kinking of blood tubing or user errors, or by a combination of excessive flow and improper cannula or catheter dimensions. The risk of acute hemolysis can be further reduced by industrial quality control, better design of dialysis equipment, and hemodialysis machine control. Adverse effects caused by chronic mechanical hemolysis need to be studied.

  8. Zfp423 Maintains White Adipocyte Identity through Suppression of the Beige Cell Thermogenic Gene Program.

    Science.gov (United States)

    Shao, Mengle; Ishibashi, Jeff; Kusminski, Christine M; Wang, Qiong A; Hepler, Chelsea; Vishvanath, Lavanya; MacPherson, Karen A; Spurgin, Stephen B; Sun, Kai; Holland, William L; Seale, Patrick; Gupta, Rana K

    2016-06-14

    The transcriptional regulators Ebf2 and Prdm16 establish and maintain the brown and/or beige fat cell identity. However, the mechanisms operating in white adipocytes to suppress the thermogenic gene program and maintain an energy-storing phenotype are less understood. Here, we report that the transcriptional regulator Zfp423 is critical for maintaining white adipocyte identity through suppression of the thermogenic gene program. Zfp423 expression is enriched in white versus brown adipocytes and suppressed upon cold exposure. Doxycycline-inducible inactivation of Zfp423 in mature adipocytes, combined with β-adrenergic stimulation, triggers a conversion of differentiated adiponectin-expressing inguinal and gonadal adipocytes into beige-like adipocytes; this reprogramming event is sufficient to prevent and reverse diet-induced obesity and insulin resistance. Mechanistically, Zfp423 acts in adipocytes to inhibit the activity of Ebf2 and suppress Prdm16 activation. These data identify Zfp423 as a molecular brake on adipocyte thermogenesis and suggest a therapeutic strategy to unlock the thermogenic potential of white adipocytes in obesity. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Ginsenoside Rg3 induces DNA damage in human osteosarcoma cells and reduces MNNG-induced DNA damage and apoptosis in normal human cells.

    Science.gov (United States)

    Zhang, Yue-Hui; Li, Hai-Dong; Li, Bo; Jiang, Sheng-Dan; Jiang, Lei-Sheng

    2014-02-01

    Panax ginseng is a Chinese medicinal herb. Ginsenosides are the main bioactive components of P. ginseng, and ginsenoside Rg3 is the primary ginsenoside. Ginsenosides can potently kill various types of cancer cells. The present study was designed to evaluate the potential genotoxicity of ginsenoside Rg3 in human osteosarcoma cells and the protective effect of ginsenoside Rg3 with respect to N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced DNA damage and apoptosis in a normal human cell line (human fibroblasts). Four human osteosarcoma cell lines (MG-63, OS732, U-2OS and HOS cells) and a normal human cell line (human fibroblasts) were employed to investigate the cytotoxicity of ginsenosides Rg3 by MTT assay. Alkaline comet assay and γH2AX focus staining were used to detect the DNA damage in MG-63 and U-2OS cells. The extent of cell apoptosis was determined by flow cytometry and a DNA ladder assay. Our results demonstrated that the cytotoxicity of ginsenoside Rg3 was dose-dependent in the human osteosarcoma cell lines, and MG-63 and U-2OS cells were the most sensitive to ginsenoside Rg3. As expected, compared to the negative control, ginsenoside Rg3 significantly increased DNA damage in a concentration-dependent manner. In agreement with the comet assay data, the percentage of γH2AX-positive MG-63 and U-2OS cells indicated that ginsenoside Rg3 induced DNA double-strand breaks in a concentration-dependent manner. The results also suggest that ginsenoside Rg3 reduces the extent of MNNG-induced DNA damage and apoptosis in human fibroblasts.

  10. TRAF6 is essential for maintenance of regulatory T cells that suppress Th2 type autoimmunity.

    Directory of Open Access Journals (Sweden)

    Go Muto

    Full Text Available Regulatory T cells (Tregs maintain immune homeostasis by limiting inflammatory responses. TRAF6 plays a key role in the regulation of innate and adaptive immunity by mediating signals from various receptors including the T-cell receptor (TCR. T cell-specific deletion of TRAF6 has been shown to induce multiorgan inflammatory disease, but the role of TRAF6 in Tregs remains to be investigated. Here, we generated Treg-specific TRAF6-deficient mice using Foxp3-Cre and TRAF6-flox mice. Treg-specific TRAF6-deficient (cKO mice developed allergic skin diseases, arthritis, lymphadenopathy and hyper IgE phenotypes. Although TRAF6-deficient Tregs possess similar in vitro suppression activity compared to wild-type Tregs, TRAF6-deficient Tregs did not suppress colitis in lymphopenic mice very efficiently due to reduced number of Foxp3-positive cells. In addition, the fraction of TRAF6-deficient Tregs was reduced compared with wild-type Tregs in female cKO mice without inflammation. Moreover, adoptive transfer of Foxp3 (+ Tregs into Rag2(-/- mice revealed that TRAF6-deficient Tregs converted into Foxp3(- cells more rapidly than WT Tregs under lymphopenic conditions. Fate-mapping analysis also revealed that conversion of Tregs from Foxp3(+ to Foxp3(- (exFoxp3 cells was accelerated in TRAF6-deficient Tregs. These data indicate that TRAF6 in Tregs plays important roles in the maintenance of Foxp3 in Tregs and in the suppression of pathogenic Th2 type conversion of Tregs.

  11. TR4 nuclear receptor suppresses HCC cell invasion via downregulating the EphA2 expression.

    Science.gov (United States)

    Jin, Ren'an; Lin, Hui; Li, Gonghui; Xu, Junjie; Shi, Liang; Chang, Chawnshang; Cai, Xiujun

    2018-02-15

    Early studies indicated that testicular nuclear receptor 4 (TR 4 ) could function as a suppressor in the transcriptional regulation of the HBV core gene expression, which might then influence the development of hepatocellular carcinoma (HCC). The direct linkage between TR 4 and HCC progression, however, remained unclear. Here, via a human clinical sample survey, we found that 13 of the 18 HCC patients studied had lower TR 4 expression in metastatic lesions than in matched primary HCC lesions, suggesting that TR 4 may play a negative role in HCC metastasis. Results from in vitro cell migration/invasion studied confirmed that TR 4 could suppress HCC cell migration/invasion. Mechanism dissection revealed that TR 4 might function through downregulating ephrin type-A receptor 2 (EphA2) expression at the transcriptional level via direct binding to the TR 4 REs located on the 5' promoter of EphA2 to suppress HCC cell migration/invasion. Targeting the EphA2 via EphA2-siRNA partially reversed the enhanced HCC cell migration/invasion with confirmed TR 4 knockdown. Notably, results from preclinical studies using in vivo mouse model with orthotopic xenograft of HCC LM3 cells also confirmed the in vitro findings. Taking these findings together, preclinical studies using multiple in vitro HCC cell lines and an in vivo mouse model all led to the conclusion that TR 4 may function as a suppressor of HCC metastasis and that targeting this newly identified TR 4 -EphA2 signaling may improve our ability to suppress HCC metastasis.

  12. MiR-214 inhibits cell growth in hepatocellular carcinoma through suppression of {beta}-catenin

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiaojun [Liver Diseases Center, The First Affiliated Hospital of Fujian Medical University, Fuzhou (China); Chen, Ji [Department of Gastrointestinal Surgery, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai (China); Li, Feng [Department of Pathology, Fujian Provincial Hospital, Fuzhou (China); Lin, Yanting [Liver Diseases Center, The First Affiliated Hospital of Fujian Medical University, Fuzhou (China); Zhang, Xiaoping; Lv, Zhongwei [Department of Interventional Therapy, Shanghai 10th People' s Hospital, School of Medicine, Tongji University, Shanghai (China); Jiang, Jiaji, E-mail: jiang_jjcn@yahoo.com.cn [Liver Diseases Center, The First Affiliated Hospital of Fujian Medical University, Fuzhou (China)

    2012-11-30

    Highlights: Black-Right-Pointing-Pointer miR-214 is frequently downregulated in human HCC cell lines and tissues. Black-Right-Pointing-Pointer miR-214 overexpression inhibits HCC cell growth in vitro and in vivo. Black-Right-Pointing-Pointer miR-214 directly targets {beta}-catenin 3 Prime -UTR in HCC cells. Black-Right-Pointing-Pointer miR-214 regulates {beta}-catenin downstream signaling molecules. -- Abstract: Mounting evidence has shown that microRNAs (miRNAs) are implicated in carcinogenesis and can function as oncogenes or tumor suppressor genes in human cancers. Recent profile studies of miRNA expression have documented a deregulation of miRNA (miR-214) in hepatocellular carcinoma (HCC). However, its potential functions and underlying mechanisms in hepatocarcinogenesis remain largely unknown. Here, we confirmed that miR-214 is significantly downregulated in HCC cells and specimens. Ectopic overexpression of miR-214 inhibited proliferation of HCC cells in vitro and tumorigenicity in vivo. Further studies revealed that miR-214 could directly target the 3 Prime -untranslated region (3 Prime -UTR) of {beta}-catenin mRNA and suppress its protein expression. Similar to the restoring miR-214 expression, {beta}-catenin downregulation inhibited cell growth, whereas restoring the {beta}-catenin expression abolished the function of miR-214. Moreover, miR-214-mediated reduction of {beta}-catenin resulted in suppression of several downstream genes including c-Myc, cyclinD1, TCF-1, and LEF-1. These findings indicate that miR-214 serves as tumor suppressor and plays substantial roles in inhibiting the tumorigenesis of HCC through suppression of {beta}-catenin. Given these, miR-214 may serve as a useful prognostic or therapeutic target for treatment of HCC.

  13. Induction of Interleukin-10 Producing Dendritic Cells As a Tool to Suppress Allergen-Specific T Helper 2 Responses

    Directory of Open Access Journals (Sweden)

    Stefan Schülke

    2018-03-01

    Full Text Available Dendritic cells (DCs are gatekeepers of the immune system that control induction and polarization of primary, antigen-specific immune responses. Depending on their maturation/activation status, the molecules expressed on their surface, and the cytokines produced DCs have been shown to either elicit immune responses through activation of effector T cells or induce tolerance through induction of either T cell anergy, regulatory T cells, or production of regulatory cytokines. Among the cytokines produced by tolerogenic DCs, interleukin 10 (IL-10 is a key regulatory cytokine limiting und ultimately terminating excessive T-cell responses to microbial pathogens to prevent chronic inflammation and tissue damage. Because of their important role in preventing autoimmune diseases, transplant rejection, allergic reactions, or in controlling chronic inflammation DCs have become an interesting tool to modulate antigen-specific immune responses. For the treatment of allergic inflammation, the aim is to downregulate allergen-specific T helper 2 (Th2 responses and the associated clinical symptoms [allergen-driven Th2 activation, Th2-driven immunoglobulin E (IgE production, IgE-mediated mast cell and basophil activation, allergic inflammation]. Here, combining the presentation of allergens by DCs with a pro-tolerogenic, IL-10-producing phenotype is of special interest to modulate allergen-specific immune responses in the treatment of allergic diseases. This review discusses the reported strategies to induce DC-derived IL-10 secretion for the suppression of allergen-specific Th2-responses with a focus on IL-10 treatment, IL-10 transduction, and the usage of both whole bacteria and bacteria-derived components. Interestingly, while IL-10-producing DCs induced either by IL-10 treatment or IL-10 transduction are arrested in an immature/semi-mature state, treatment of DCs with live or killed bacteria as well as isolated bacterial components results in the induction of

  14. Clustered DNA damages induced in human hematopoietic cells by low doses of ionizing radiation

    Science.gov (United States)

    Sutherland, Betsy M.; Bennett, Paula V.; Cintron-Torres, Nela; Hada, Megumi; Trunk, John; Monteleone, Denise; Sutherland, John C.; Laval, Jacques; Stanislaus, Marisha; Gewirtz, Alan

    2002-01-01

    Ionizing radiation induces clusters of DNA damages--oxidized bases, abasic sites and strand breaks--on opposing strands within a few helical turns. Such damages have been postulated to be difficult to repair, as are double strand breaks (one type of cluster). We have shown that low doses of low and high linear energy transfer (LET) radiation induce such damage clusters in human cells. In human cells, DSB are about 30% of the total of complex damages, and the levels of DSBs and oxidized pyrimidine clusters are similar. The dose responses for cluster induction in cells can be described by a linear relationship, implying that even low doses of ionizing radiation can produce clustered damages. Studies are in progress to determine whether clusters can be produced by mechanisms other than ionizing radiation, as well as the levels of various cluster types formed by low and high LET radiation.

  15. DNA-Damage-Induced Type I Interferon Promotes Senescence and Inhibits Stem Cell Function

    Directory of Open Access Journals (Sweden)

    Qiujing Yu

    2015-05-01

    Full Text Available Expression of type I interferons (IFNs can be induced by DNA-damaging agents, but the mechanisms and significance of this regulation are not completely understood. We found that the transcription factor IRF3, activated in an ATM-IKKα/β-dependent manner, stimulates cell-autonomous IFN-β expression in response to double-stranded DNA breaks. Cells and tissues with accumulating DNA damage produce endogenous IFN-β and stimulate IFN signaling in vitro and in vivo. In turn, IFN acts to amplify DNA-damage responses, activate the p53 pathway, promote senescence, and inhibit stem cell function in response to telomere shortening. Inactivation of the IFN pathway abrogates the development of diverse progeric phenotypes and extends the lifespan of Terc knockout mice. These data identify DNA-damage-response-induced IFN signaling as a critical mechanism that links accumulating DNA damage with senescence and premature aging.

  16. Fenofibrate suppressed proliferation and migration of human neuroblastoma cells via oxidative stress dependent of TXNIP upregulation

    Energy Technology Data Exchange (ETDEWEB)

    Su, Cunjin; Shi, Aiming; Cao, Guowen [Department of Pharmacy, The Second Affiliated Hospital of Soochow University, Suzhou, 215004 (China); Tao, Tao [Department of Urology, Zhongda Hospital, Medical School of Southeast University, Nanjing, 210009 (China); Chen, Ruidong [Department of Gastroenterology, The Second Affiliated Hospital of Soochow University, Suzhou, 215004 (China); Hu, Zhanhong; Shen, Zhu; Tao, Hong; Cao, Bin [Department of Pharmacy, The Second Affiliated Hospital of Soochow University, Suzhou, 215004 (China); Hu, Duanmin, E-mail: hudmsdfey@sina.com [Department of Gastroenterology, The Second Affiliated Hospital of Soochow University, Suzhou, 215004 (China); Bao, Junjie, E-mail: baojjsdfey@sina.com [Department of Pharmacy, The Second Affiliated Hospital of Soochow University, Suzhou, 215004 (China)

    2015-05-15

    There are no appropriate drugs for metastatic neuroblastoma (NB), which is the most common extra-cranial solid tumor for childhood. Thioredoxin binding protein (TXNIP), the endogenous inhibitor of ROS elimination, has been identified as a tumor suppressor in various solid tumors. It reported that fenofibrate exerts anti-tumor effects in several human cancer cell lines. However, its detail mechanisms remain unclear. The present study assessed the effects of fenofibrate on NB cells and investigated TXNIP role in its anti-tumor mechanisms. We used MTT assay to detect cells proliferation, starch wound test to investigate cells migration, H{sub 2}DCF-DA to detect intracellular ROS, siRNA to interfere TXNIP and peroxisome proliferator-androgen receptor-alpha (PPAR-α) expression, western blot to determine protein levels, flow cytometry to analyze apoptosis. Fenofibrate suppressed proliferation and migration of NB cells, remarkably increased intracellular ROS, upregulated TXNIP expression, promoted cell apoptosis. Furthermore, inhibition of TXNIP expression attenuated anti-tumor effects of fenofibrate, while inhibition of PPAR-α had no influences. Our results indicated the anti-tumor role of fenofibrate on NB cells by exacerbating oxidative stress and inducing apoptosis was dependent on the upregulation of TXNIP. - Highlights: • We found that fenofibrate suppressed proliferation and migration of NB cells. • We found that fenofibrate remarkably increased intracellular ROS, upregulated TXNIP expression, and promoted cell apoptosis. • Inhibition of TXNIP expression attenuated anti-tumor effects of fenofibrate, while inhibition of PPAR-α had no influences. • Our results indicated the anti-tumor role of fenofibrate on NB cells was dependent on the upregulation of TXNIP.

  17. Fenofibrate suppressed proliferation and migration of human neuroblastoma cells via oxidative stress dependent of TXNIP upregulation

    International Nuclear Information System (INIS)

    Su, Cunjin; Shi, Aiming; Cao, Guowen; Tao, Tao; Chen, Ruidong; Hu, Zhanhong; Shen, Zhu; Tao, Hong; Cao, Bin; Hu, Duanmin; Bao, Junjie

    2015-01-01

    There are no appropriate drugs for metastatic neuroblastoma (NB), which is the most common extra-cranial solid tumor for childhood. Thioredoxin binding protein (TXNIP), the endogenous inhibitor of ROS elimination, has been identified as a tumor suppressor in various solid tumors. It reported that fenofibrate exerts anti-tumor effects in several human cancer cell lines. However, its detail mechanisms remain unclear. The present study assessed the effects of fenofibrate on NB cells and investigated TXNIP role in its anti-tumor mechanisms. We used MTT assay to detect cells proliferation, starch wound test to investigate cells migration, H 2 DCF-DA to detect intracellular ROS, siRNA to interfere TXNIP and peroxisome proliferator-androgen receptor-alpha (PPAR-α) expression, western blot to determine protein levels, flow cytometry to analyze apoptosis. Fenofibrate suppressed proliferation and migration of NB cells, remarkably increased intracellular ROS, upregulated TXNIP expression, promoted cell apoptosis. Furthermore, inhibition of TXNIP expression attenuated anti-tumor effects of fenofibrate, while inhibition of PPAR-α had no influences. Our results indicated the anti-tumor role of fenofibrate on NB cells by exacerbating oxidative stress and inducing apoptosis was dependent on the upregulation of TXNIP. - Highlights: • We found that fenofibrate suppressed proliferation and migration of NB cells. • We found that fenofibrate remarkably increased intracellular ROS, upregulated TXNIP expression, and promoted cell apoptosis. • Inhibition of TXNIP expression attenuated anti-tumor effects of fenofibrate, while inhibition of PPAR-α had no influences. • Our results indicated the anti-tumor role of fenofibrate on NB cells was dependent on the upregulation of TXNIP

  18. Tetrandrine suppresses proliferation, induces apoptosis, and inhibits migration and invasion in human prostate cancer cells

    Directory of Open Access Journals (Sweden)

    Wei Liu

    2015-01-01

    Full Text Available Tetrandrine (TET, a traditional Chinese medicine, exerts remarkable anticancer activity on various cancer cells. However, little is known about the effect of TET on human prostate cancer cells, and the mechanism of function of TET on prostate cancer has not yet been elucidated. To investigate the effects of TET on the suppression of proliferation, induction of apoptosis, and inhibition of migration and invasion in human prostate cancer cell lines, DU145 and PC-3. Inhibition of growth was determined by 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide assay and clone formation assay, and flow cytometry analysis was performed to detect the induction of apoptosis. Activation of poly (ADP-ribose polymerase, caspase-3, Akt, phospho-Akt, Bcl-2, and Bax was analyzed by Western blotting. Wound healing assay and transwell migration assay were used to evaluate the effect of TET on migration and invasion of cancer cells. TET inhibited the growth of DU145 and PC-3 cells in a dose- and time-dependent manner. Cell cloning was inhibited in the presence of TET in DU145 and PC-3 cells. TET suppressed the migration of DU145 and PC-3 cells. Transwell invasion assay showed that TET significantly weakened invasion capacity of DU145 and PC-3 cells. TET exhibited strong inhibitory effect on proliferation, migration, and invasion of prostate cancer cells. In addition, TET induced apoptosis in a dose-dependent manner by activating the caspase cascade and inhibiting phosphoinositide 3-kinase-Akt signal pathway. The accumulating evidence suggests that TET could be a potential therapeutic candidate against prostate cancer in a clinical setting.

  19. Microbiota promotes systemic T-cell survival through suppression of an apoptotic factor.

    Science.gov (United States)

    Soto, Raymond; Petersen, Charisse; Novis, Camille L; Kubinak, Jason L; Bell, Rickesha; Stephens, W Zac; Lane, Thomas E; Fujinami, Robert S; Bosque, Alberto; O'Connell, Ryan M; Round, June L

    2017-05-23

    Symbiotic microbes impact the severity of a variety of diseases through regulation of T-cell development. However, little is known regarding the molecular mechanisms by which this is accomplished. Here we report that a secreted factor, Erdr1, is regulated by the microbiota to control T-cell apoptosis. Erdr1 expression was identified by transcriptome analysis to be elevated in splenic T cells from germfree and antibiotic-treated mice. Suppression of Erdr1 depends on detection of circulating microbial products by Toll-like receptors on T cells, and this regulation is conserved in human T cells. Erdr1 was found to function as an autocrine factor to induce apoptosis through caspase 3. Consistent with elevated levels of Erdr1, germfree mice have increased splenic T-cell apoptosis. RNA sequencing of Erdr1-overexpressing cells identified the up-regulation of genes involved in Fas-mediated cell death, and Erdr1 fails to induce apoptosis in Fas-deficient cells. Importantly, forced changes in Erdr1 expression levels dictate the survival of auto-reactive T cells and the clinical outcome of neuro-inflammatory autoimmune disease. Cellular survival is a fundamental feature regulating appropriate immune responses. We have identified a mechanism whereby the host integrates signals from the microbiota to control T-cell apoptosis, making regulation of Erdr1 a potential therapeutic target for autoimmune disease.

  20. MiR-223 suppresses cell proliferation by targeting IGF-1R.

    Directory of Open Access Journals (Sweden)

    Cheng You Jia

    Full Text Available To study the roles of microRNA-223 (miR-223 in regulation of cell growth, we established a miR-223 over-expression model in HeLa cells infected with miR-223 by Lentivirus pLL3.7 system. We observed in this model that miR-223 significantly suppressed the proliferation, growth rate, colony formation of HeLa cells in vitro, and in vivo tumorigenicity or tumor formation in nude mice. To investigate the mechanisms involved, we scanned and examined the potential and putative target molecules of miR-223 by informatics, quantitative PCR and Western blot, and found that insulin-like growth factor-1 receptor (IGF-1R was the functional target of miR-223 inhibition of cell proliferation. Targeting IGF-1R by miR-223 was not only seen in HeLa cells, but also in leukemia and hepatoma cells. The downstream pathway, Akt/mTOR/p70S6K, to which the signal was mediated by IGF-1R, was inhibited as well. The relative luciferase activity of the reporter containing wild-type 3'UTR(3'untranslated region of IGF-1R was significantly suppressed, but the mutant not. Silence of IGF-1R expression by vector-based short hairpin RNA resulted in the similar inhibition with miR-223. Contrarily, rescued IGF-1R expression in the cells that over-expressed miR-223, reversed the inhibition caused by miR-223 via introducing IGF-1R cDNA that didn't contain the 3'UTR. Meanwhile, we also noted that miR-223 targeted Rasa1, but the downstream molecules mediated by Rasa1 was neither targeted nor regulated. Therefore we believed that IGF-1R was the functional target for miR-223 suppression of cell proliferation and its downstream PI3K/Akt/mTOR/p70S6K pathway suppressed by miR-223 was by targeting IGF-1R.

  1. AM251 Suppresses Epithelial-Mesenchymal Transition of Renal Tubular Epithelial Cells.

    Directory of Open Access Journals (Sweden)

    Tomoyo Yoshinaga

    Full Text Available Epithelial-mesenchymal transition (EMT of renal tubular epithelial cells is one of the causative mechanisms of kidney fibrosis. In our study, we screened lipophilic compounds using a lipid library including approximately 200 lipids to identify those that suppressed EMT induced by a transforming growth factor (TGF-β1 stimulus. Initial screening was performed with the immortalized HK-2 renal tubule epithelial cell line. The most promising compounds were further tested in RPTEC primary renal tubule epithelial cells. We found that the synthetic lipid AM251 suppressed two hallmark events associated with EMT, the upregulation of collagen 1A1 (COL1A1 and downregulation of E-cadherin. Though AM251 is known to act as an antagonist for the cannabinoid receptor type 1 (CB1 and an agonist for the G protein-coupled receptor 55 (GRP55, the suppression of EMT by AM251 was not mediated through either receptor. Microarray analyses revealed that AM251 inhibited induction of several EMT transcription factors such as SNAIL1, which is the key inducer of EMT, and the AP-1 transcription factors FOSB and JUNB. Activation of SMAD2/3 and p38 mitogen-activated protein kinase (MAPK was inhibited by AM251, with greater inhibition of the latter, indicating that AM251 acted upstream of SMAD/p38 MAPK in the TGF-β signaling pathway. Our findings regarding the effects of AM251 on the TGF-β signaling pathway may inform development of a novel therapeutic agent suppressing EMT, thus preventing kidney fibrosis.

  2. Antrodia camphorata Grown on Germinated Brown Rice Suppresses Melanoma Cell Proliferation by Inducing Apoptosis and Cell Differentiation and Tumor Growth

    Directory of Open Access Journals (Sweden)

    Minjung Song

    2013-01-01

    Full Text Available Antrodia camphorata grown on germinated brown rice (CBR was prepared to suppress melanoma development. CBR extracts were divided into hexane, EtOAc, BuOH, and water fractions. Among all the fractions, EtOAc fraction showed the best suppressive effect on B16F10 melanoma cell proliferation by CCK-8 assay. It also showed the increased cell death and the changed cellular morphology after CBR treatment. Annexin V-FITC/PI, flow cytometry, and western blotting were performed to elucidate anticancer activity of CBR. The results showed that CBR induced p53-mediated apoptotic cell death of B16F10. CBR EtOAc treatment increased melanin content and melanogenesis-related proteins of MITF and TRP-1 expressions, which supports its anticancer activity. Its potential as an anticancer agent was further investigated in tumor-xenografted mouse model. In melanoma-xenografted mouse model, melanoma tumor growth was significantly suppressed under CBR EtOAc fraction treatment. HPLC analysis of CBR extract showed peak of adenosine. In conclusion, CBR extracts notably inhibited B16F10 melanoma cell proliferation through the p53-mediated apoptosis induction and increased melanogenesis. These findings suggest that CBR EtOAc fraction can act as an effective anticancer agent to treat melanoma.

  3. The impact of impaired DNA damage responses on cells, tissues and organisms

    NARCIS (Netherlands)

    Yi, Xia

    2007-01-01

    Current cancer therapies rely mainly on DNA damaging insults (irradiation, DNA alkylating agents, DNA synthesis inhibitors etc.). The rationale behind these treatments is that rapidly growing cancer cells suffer more from DNA damaging insults. Unfortunately, the majority of current therapies fail to

  4. Radioadaptive response. Efficient repair of radiation-induced DNA damage in adapted cells

    International Nuclear Information System (INIS)

    Ikushima, Takaji; Aritomi, Hisako; Morisita, Jun

    1996-01-01

    To verify the hypothesis that the induction of a novel, efficient repair mechanism for chromosomal DNA breaks may be involved in the radioadaptive response, the repair kinetics of DNA damage has been studied in cultured Chinese hamster V79 cells with single-cell gel electrophoresis. The cells were adapted by priming exposure with 5 cGy of γ-rays and 4-h incubation at 37C. There were no indication of any difference in the initial yields of DNA double-strand breaks induced by challenging doses from non-adapted cells and from adapted cells. The rejoining of DNA double-strand breaks was monitored over 120 min after the adapted cells were challenged with 5 or 1.5 Gy, doses at the same level to those used in the cytogenetical adaptive response. The rate of DNA damage repair in adapted cells was higher than that in non-adapted cells, and the residual damage was less in adapted cells than in non-adapted cells. These results indicate that the radioadaptive response may result from the induction of a novel, efficient DNA repair mechanism which leads to less residual damage, but not from the induction of protective functions that reduce the initial DNA damage

  5. The proximal tubular cell, a key player in renal damage

    NARCIS (Netherlands)

    Timmeren, Mirjan Miranda van

    2008-01-01

    A decline in renal function is associated with the degree of proteinuria and with histological findings of glomerulosclerosis and interstitial fibrosis. Proteinuria is not only a marker of renal damage, but ultrafiltered proteins can be toxic to the kidney, thereby contributing to

  6. Circulating nucleic acids damage DNA of healthy cells by integrating ...

    Indian Academy of Sciences (India)

    2015-02-04

    Feb 4, 2015 ... DNAfs and Cfs are physiological, continuously arising, endogenous DNA damaging agents with implications to ageing and a multitude of human pathologies including initiation of cancer. [Mittra I, Khare NK, Raghuram GV, Chaubal R, Khambatti F, Gupta D, Gaikwad A, Prasannan P, Singh A, Iyer A, Singh A ...

  7. Synthetic lethal interaction between oncogenic KRAS dependency and STK33 suppression in human cancer cells.

    Science.gov (United States)

    Scholl, Claudia; Fröhling, Stefan; Dunn, Ian F; Schinzel, Anna C; Barbie, David A; Kim, So Young; Silver, Serena J; Tamayo, Pablo; Wadlow, Raymond C; Ramaswamy, Sridhar; Döhner, Konstanze; Bullinger, Lars; Sandy, Peter; Boehm, Jesse S; Root, David E; Jacks, Tyler; Hahn, William C; Gilliland, D Gary

    2009-05-29

    An alternative to therapeutic targeting of oncogenes is to perform "synthetic lethality" screens for genes that are essential only in the context of specific cancer-causing mutations. We used high-throughput RNA interference (RNAi) to identify synthetic lethal interactions in cancer cells harboring mutant KRAS, the most commonly mutated human oncogene. We find that cells that are dependent on mutant KRAS exhibit sensitivity to suppression of the serine/threonine kinase STK33 irrespective of tissue origin, whereas STK33 is not required by KRAS-independent cells. STK33 promotes cancer cell viability in a kinase activity-dependent manner by regulating the suppression of mitochondrial apoptosis mediated through S6K1-induced inactivation of the death agonist BAD selectively in mutant KRAS-dependent cells. These observations identify STK33 as a target for treatment of mutant KRAS-driven cancers and demonstrate the potential of RNAi screens for discovering functional dependencies created by oncogenic mutations that may enable therapeutic intervention for cancers with "undruggable" genetic alterations.

  8. Onbaekwon Suppresses Colon Cancer Cell Invasion by Inhibiting Expression of the CXC Chemokine Receptor 4.

    Science.gov (United States)

    Kim, Buyun; Yoon, Jaewoo; Yoon, Seong Woo; Park, Byoungduck

    2017-06-01

    Cysteine X cysteine (CXC) chemokine receptor 4 (CXCR4) and C-X-C motif chemokine 12 (CXCL12) were originally identified as chemoattractants between immune cells and sites of inflammation. Since studies have validated an increased level of CXCL12 and its receptor in patients with colorectal cancers, CXCL12/CXCR4 axis has been considered as a valuable marker of cancer metastasis. Therefore, identification of CXCR4 inhibitors has great potential to abrogate tumor metastasis. Onbaekwon (OBW) is a complex herbal formula that is derived from the literature of traditional Korean medicine Dongeuibogam. In this study, we demonstrated that OBW suppressed CXCR4 expression in various cancer cell types in a concentration- and time-dependent manner. Both proteasomal and lysosomal inhibitors had no effect to prevent the OBW-induced suppression of CXCR4, suggesting that the inhibitory effect of OBW was not due to proteolytic degradation but occurred at the transcriptional level. Electrophoretic mobility shift assay further confirmed that OBW could block endogenous activation of nuclear factor kappa B, a key transcription factor that regulates the expression of CXCR4 in colon cancer cells. Consistent with the aforementioned molecular basis, OBW abolished cell invasion induced by CXCL12 in colon cancer cells. Together, our results suggest that OBW, as a novel inhibitor of CXCR4, could be a promising therapeutic agent contributing to cancer treatment.

  9. Drosera rotundifolia and Drosera tokaiensis suppress the activation of HMC-1 human mast cells.

    Science.gov (United States)

    Fukushima, Kenji; Nagai, Kanji; Hoshi, Yoshikazu; Masumoto, Saeko; Mikami, Ichiho; Takahashi, Yumiko; Oike, Hideaki; Kobori, Masuko

    2009-08-17

    Several Northern Hemisphere Drosera species have been used in the therapy of respiratory tract infections as the traditional medicine Droserae Herba. To determine the anti-inflammatory effects of Drosera species and to investigate a substitute material for Droserae Herba, we examined the effect of extracts of Drosera rotundifolia, Drosera tokaiensis and Drosera spatulata on activated T cell membrane (aTc-m)-induced inflammatory gene expression in HMC-1 human mast cells. Drosera rotundifolia, Drosera spatulata and Drosera tokaiensis were collected in Japan. Herbs were extracted with 80% EtOH, and subsequently applied to OASIS HLB column. HMC-1 cells were treated with each Drosera column-adsorbed fraction for 15min, and subsequently added to aTc-m and incubated for 16h. Inflammatory gene and protein expressions were determined by DNA microarray, RT-PCR and Western blotting. Drosera rotundifolia and Drosera tokaiensis fractions, but not the Drosera spatulata fraction, suppressed inflammatory gene expression induced by aTc-m in HMC-1 cells. Drosera rotundifolia and Drosera tokaiensis suppressed activation of HMC-1 cells induced by aTc-m. Since the Drosera tokaiensis fraction was more effective than the traditionally used Drosera rotundifolia, Drosera tokaiensis is a likely substitute as a source of Droserae Herba.

  10. Growth suppression of Leydig TM3 cells mediated by aryl hydrocarbon receptor

    International Nuclear Information System (INIS)

    Iseki, Minoru; Ikuta, Togo; Kobayashi, Tetsuya; Kawajiri, Kaname

    2005-01-01

    Exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin induces developmental toxicity in reproductive organs. To elucidate the function of AhR, we generated stable transformants of TM3 cells overexpressing wild-type aryl hydrocarbon receptor (AhR) or its mutants which carried mutations in nuclear localization signal or nuclear export signal. In the presence of 3-methylcholanthrene (MC), proliferation of the cells transfected with wild-type AhR was completely suppressed, whereas cells expressing AhR mutants proliferated in a manner equivalent to control TM3 cells, suggesting AhR-dependent growth inhibition. The suppression was associated with up-regulation of cyclin-dependent kinase inhibitor p21 Cip1 , which was abolished by pretreatment with actinomycin D. A p38 MAPK specific inhibitor, SB203580, blocked the increase of p21 Cip1 mRNA in response to MC. Treatment with indigo, another AhR ligand, failed to increase of p21 Cip1 mRNA, although up-regulation of mRNA for CYP1A1 was observed. These data suggest AhR in Leydig cells mediates growth inhibition by inducing p21 Cip1

  11. Black Rice Anthocyanins Suppress Metastasis of Breast Cancer Cells by Targeting RAS/RAF/MAPK Pathway.

    Science.gov (United States)

    Chen, Xiang-Yan; Zhou, Jie; Luo, Li-Ping; Han, Bin; Li, Fei; Chen, Jing-Yao; Zhu, Yan-Feng; Chen, Wei; Yu, Xiao-Ping

    2015-01-01

    Overexpression of human epidermal growth factor receptor 2 (HER2) drives the biology of 30% of breast cancer cases. As a transducer of HER2 signaling, RAS/RAF/MAPK pathway plays a pivotal role in the development of breast cancer. In this study, we examined the molecular mechanisms underlying the chemopreventive effects of black rice anthocyanins (BRACs) extract and identified their molecular targets in HER2(+) breast cancer cells. Treatment of MDA-MB-453 cells (HER2(+)) with BRACs inhibited cell migration and invasion, suppressed the activation of mitogen-activated protein kinase kinase kinase (RAF), mitogen-activated protein kinase kinase (MEK), and c-Jun N-terminal kinase (JNK), and downregulated the secretion of matrix metalloproteinase 2 (MMP2) and MMP9. BRACs also weakened the interactions of HER2 with RAF, MEK, and JNK proteins, respectively, and decreased the mRNA expression of raf, mek, and jnk. Further, we found combined treatment with BRACs and RAF, MEK, or JNK inhibitors could enhance the antimetastatic activity, compared with that of each treatment. Transient transfection with small interfering RNAs (siRNAs) specific for raf, mek, and jnk inhibited their mRNA expression in MDA-MB-453 cells. Moreover, cotreatment with BRACs and siRNA induces a more remarkable inhibitory effect than that by either substance alone. In summary, our study suggested that BRACs suppress metastasis in breast cancer cells by targeting the RAS/RAF/MAPK pathway.

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

    Science.gov (United States)

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

    2010-01-01

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

  13. Actin as Deathly Switch? How Auxin Can Suppress Cell-Death Related Defence

    Science.gov (United States)

    Chang, Xiaoli; Riemann, Michael; Liu, Qiong; Nick, Peter

    2015-01-01

    Plant innate immunity is composed of two layers – a basal immunity, and a specific effector-triggered immunity, which is often accompanied by hypersensitive cell death. Initiation of cell death depends on a complex network of signalling pathways. The phytohormone auxin as central regulator of plant growth and development represents an important component for the modulation of plant defence. In our previous work, we showed that cell death is heralded by detachment of actin from the membrane. Both, actin response and cell death, are triggered by the bacterial elicitor harpin in grapevine cells. In this study we investigated, whether harpin-triggered actin bundling is necessary for harpin-triggered cell death. Since actin organisation is dependent upon auxin, we used different auxins to suppress actin bundling. Extracellular alkalinisation and transcription of defence genes as the basal immunity were examined as well as cell death. Furthermore, organisation of actin was observed in response to pharmacological manipulation of reactive oxygen species and phospholipase D. We find that induction of defence genes is independent of auxin. However, auxin can suppress harpin-induced cell death and also counteract actin bundling. We integrate our findings into a model, where harpin interferes with an auxin dependent pathway that sustains dynamic cortical actin through the activity of phospholipase D. The antagonism between growth and defence is explained by mutual competition for signal molecules such as superoxide and phosphatidic acid. Perturbations of the auxin-actin pathway might be used to detect disturbed integrity of the plasma membrane and channel defence signalling towards programmed cell death. PMID:25933033

  14. MiR-328 suppresses the survival of esophageal cancer cells by targeting PLCE1

    Energy Technology Data Exchange (ETDEWEB)

    Han, Na [Department of Oncology, The Second Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, 450014 (China); Zhao, Wenchao [Department of Physiology and Neurobiology, College of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan, 450001 (China); Zhang, Zhongmian [Department of Oncology, The Second Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, 450014 (China); Zheng, Pengyuan, E-mail: pengyuanzhengcn@163.com [No.3, Kangfuqian Street, Department of Gastroenterology, The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, 450052 (China); No.3, Kangfuqian Street, Medical Microecology and Clinical Nutrition Research Institute of Zhengzhou University, Zhengzhou, Henan, 450052 (China)

    2016-01-29

    Esophageal cancer (EC) is the sixth leading cause of death worldwide. Recent studies have highlighted the vital role of microRNAs (miRNAs) in EC development and diagnosis. In our study, qPCR analysis showed that miRNA-328 was expressed at significantly low levels in EC109 and EC9706 cells. The results also showed that overexpression of miR-328 by lentivirus-mediated gene transfer markedly inhibited cell proliferation and invasion, and enhanced apoptosis; whereas, inhibition of miR-328 significantly promoted cell proliferation and invasion, and suppressed apoptosis in EC109 and EC9706 cells. Dual-luciferase reporter assay confirmed that miR-328 directly targeted phospholipase C epsilon 1 (PLCE1) by binding to target sequences in the 3′-UTR. qPCR and Western blot analysis showed that the PLCE1 was overexpressed in EC109 and EC9706 cells. Additionally, we found that miR-328 overexpression decreased PLCE1 mRNA and protein levels, while miR-328 inhibition enhanced the PLCE1 expression. Further analysis showed that PLCE1 overexpression rescued the inhibitory effect of miR-328 on cell proliferation and invasion, and repressed the promotive effect of miR-328 on cell apoptosis. In conclusion, our results suggest that miR-328 suppresses the survival of EC cells by regulating PLCE1 expression, which might be a potential therapeutic method for EC. - Highlights: • PLCE1 was a target gene of miR-328. • MiR-328 overexpression decreased PLCE1 expression. • PLCE1 overexpression rescued the inhibitory effect of miR-328 on the survival of EC cells.

  15. Overexpression of Oct4 suppresses the metastatic potential of breast cancer cells via Rnd1 downregulation.

    Science.gov (United States)

    Shen, Long; Qin, Kunhua; Wang, Dekun; Zhang, Yan; Bai, Nan; Yang, Shengyong; Luo, Yunping; Xiang, Rong; Tan, Xiaoyue

    2014-11-01

    Although Oct4 is known as a critical transcription factor involved in maintaining "stemness", its role in tumor metastasis is still controversial. Herein, we overexpressed and silenced Oct4 expression in two breast cancer cell lines, MDA-MB-231 and 4T1, separately. Our data showed that ectopic overexpression of Oct4 suppressed cell migration and invasion in vitro and the formation of metastatic lung nodules in vivo. Conversely, Oct4 downregulation increased the metastatic potential of breast cancer cells both in vitro and in vivo. Furthermore, we identified Rnd1 as the downstream target of Oct4 by ribonucleic acid sequencing (RNA-seq) analysis, which was significantly downregulated upon Oct4 overexpression. Chromatin immunoprecipitation assays revealed the binding of Oct4 to the promoter region of Rnd1 by ectopic overexpression of Oct4. Dual luciferase assays indicated that Oct4 overexpression suppressed transcriptional activity of the Rnd1 promoter. Moreover, overexpression of Rnd1 partially rescued the inhibitory effects of Oct4 on the migration and invasion of breast cancer cells. Overexpression of Rnd1 counteracted the influence of Oct4 on the formation of cell adhesion and lamellipodia, which implied a potential underlying mechanism involving Rnd1. In addition, we also found that overexpression of Oct4 led to an elevation of E-cadherin expression, even in 4T1 cells that possess a relatively high basal level of E-cadherin. Rnd1 overexpression impaired the promoting effects of Oct4 on E-cadherin expression in MDA-MB-231 cells. These results suggest that Oct4 affects the metastatic potential of breast cancer cells through Rnd1-mediated effects that influence cell motility and E-cadherin expression. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. MiR-328 suppresses the survival of esophageal cancer cells by targeting PLCE1

    International Nuclear Information System (INIS)

    Han, Na; Zhao, Wenchao; Zhang, Zhongmian; Zheng, Pengyuan

    2016-01-01

    Esophageal cancer (EC) is the sixth leading cause of death worldwide. Recent studies have highlighted the vital role of microRNAs (miRNAs) in EC development and diagnosis. In our study, qPCR analysis showed that miRNA-328 was expressed at significantly low levels in EC109 and EC9706 cells. The results also showed that overexpression of miR-328 by lentivirus-mediated gene transfer markedly inhibited cell proliferation and invasion, and enhanced apoptosis; whereas, inhibition of miR-328 significantly promoted cell proliferation and invasion, and suppressed apoptosis in EC109 and EC9706 cells. Dual-luciferase reporter assay confirmed that miR-328 directly targeted phospholipase C epsilon 1 (PLCE1) by binding to target sequences in the 3′-UTR. qPCR and Western blot analysis showed that the PLCE1 was overexpressed in EC109 and EC9706 cells. Additionally, we found that miR-328 overexpression decreased PLCE1 mRNA and protein levels, while miR-328 inhibition enhanced the PLCE1 expression. Further analysis showed that PLCE1 overexpression rescued the inhibitory effect of miR-328 on cell proliferation and invasion, and repressed the promotive effect of miR-328 on cell apoptosis. In conclusion, our results suggest that miR-328 suppresses the survival of EC cells by regulating PLCE1 expression, which might be a potential therapeutic method for EC. - Highlights: • PLCE1 was a target gene of miR-328. • MiR-328 overexpression decreased PLCE1 expression. • PLCE1 overexpression rescued the inhibitory effect of miR-328 on the survival of EC cells.

  17. Targeting polo-like kinase 1 suppresses essential functions of alloreactive T cells.

    Science.gov (United States)

    Berges, Carsten; Chatterjee, Manik; Topp, Max S; Einsele, Hermann

    2016-06-01

    Acute graft-versus-host disease (aGvHD) is still a major cause of transplant-related mortality after allogeneic stem cell transplantation (ASCT). It requires immunosuppressive treatments that broadly abrogate T cell responses including beneficial ones directed against tumor cells or infective pathogens. Polo-like kinase 1 (PLK1) is overexpressed in many cancer types including leukemia, and clinical studies demonstrated that targeting PLK1 using selective PLK1 inhibitors resulted in inhibition of proliferation and induction of apoptosis predominantly in tumor cells, supporting the feasibility of PLK1 as target for anticancer therapy. Here, we show that activation of alloreactive T cells (Tallo) up-regulate expression of PLK1, suggesting that PLK1 is a potential new candidate for dual therapy of aGvHD and leukemia after ASCT. Inhibition of PLK1, using PLK1-specific inhibitor GSK461364A selectively depletes Tallo by preventing activation and by inducing apoptosis in already activated Tallo, while memory T cells are preserved. Activated Tallo cells which survive exposure to PLK1 undergo inhibition of proliferation by induction of G2/M cell cycle arrest, which is accompanied by accumulation of cell cycle regulator proteins p21(WAF/CIP1), p27(Kip1), p53 and cyclin B1, whereas abundance of CDK4 decreased. We also show that suppressive effects of PLK1 inhibition on Tallo were synergistically enhanced by concomitant inhibition of molecular chaperone Hsp90. Taken together, our data suggest that PLK1 inhibition represents a reasonable dual strategy to suppress residual tumor growth and efficiently deplete Tallo, and thus provide a rationale to selectively prevent and treat aGvHD.

  18. Regulatory T cells expanded from HIV-1-infected individuals maintain phenotype, TCR repertoire and suppressive capacity.

    Directory of Open Access Journals (Sweden)

    Mathieu Angin

    Full Text Available While modulation of regulatory T cell (Treg function and adoptive Treg transfer are being explored as therapeutic modalities in the context of autoimmune diseases, transplantation and cancer, their role in HIV-1 pathogenesis remains less well defined. Controversy persists regarding their beneficial or detrimental effects in HIV-1 disease, which warrants further detailed exploration. Our objectives were to investigate if functional CD4(+ Tregs can be isolated and expanded from HIV-1-infected individuals for experimental or potential future therapeutic use and to determine phenotype and suppressive capacity of expanded Tregs from HIV-1 positive blood and tissue. Tregs and conventional T cell controls were isolated from blood and gut-associated lymphoid tissue of individuals with HIV-1 infection and healthy donors using flow-based cell-sorting. The phenotype of expanded Tregs was assessed by flow-cytometry and quantitative PCR. T-cell receptor ß-chain (TCR-β repertoire diversity was investigated by deep sequencing. Flow-based T-cell proliferation and chromium release cytotoxicity assays were used to determine Treg suppressive function. Tregs from HIV-1 positive individuals, including infants, were successfully expanded from PBMC and GALT. Expanded Tregs expressed high levels of FOXP3, CTLA4, CD39 and HELIOS and exhibited a highly demethylated TSDR (Treg-specific demethylated region, characteristic of Treg lineage. The TCRß repertoire was maintained following Treg expansion and expanded Tregs remained highly suppressive in vitro. Our data demonstrate that Tregs can be expanded from blood and tissue compartments of HIV-1+ donors with preservation of Treg phenotype, function and TCR repertoire. These results are highly relevant for the investigation of potential future therapeutic use, as currently investigated for other disease states and hold great promise for detailed studies on the role of Tregs in HIV-1 infection.

  19. Haloperidol suppresses murine dendritic cell maturation and priming of the T helper 1-type immune response.

    Science.gov (United States)

    Matsumoto, Atsuhiro; Ohta, Noriyuki; Goto, Yukiko; Kashiwa, Yozo; Yamamoto, Shunsuke; Fujino, Yuji

    2015-04-01

    Haloperidol has immunomodulatory effects when used to treat patients with schizophrenia and also is used to sedate critically ill patients in the intensive care unit. Although the mechanism by which haloperidol affects immune function is unclear, one possibility is that it alters dendritic cell (DC) function. DCs are potent antigen-presenting cells that influence the activation and maturation of T lymphocytes. In this study, we investigated the in vitro and in vivo immunomodulatory effects of haloperidol on DC-mediated immune responses. Using bone marrow-derived DCs in cell culture, we evaluated the effect of haloperidol on expression of costimulatory molecules (CD80 and CD86), major histocompatibility complex class ΙІ molecules, and the DC maturation marker CD83. DC culture supernatants also were evaluated for interleukin-12 p40 levels. In addition, we analyzed the effect of haloperidol on a mixed cell culture containing DCs and lymphocytes and measured the secretion of interferon-γ in the culture supernatants. We also assessed the in vivo effects of haloperidol on hapten-induced contact hypersensitivity responses. Haloperidol inhibited the expression of CD80, CD86, major histocompatibility complex class ΙІ, and CD83 molecules on DCs and the secretion of interleukin-12p40 in DC culture supernatants. In mixed cell cultures containing both T cells (CD4 and CD8α) and DCs, haloperidol-treated DCs suppressed the proliferation of allogeneic T cells and effectively inhibited the production of interferon-γ. In vivo, haloperidol reduced hapten-induced contact hypersensitivity responses. Furthermore, an antagonist to D2-like receptor suppressed the maturation of DCs in a manner similar to haloperidol. The results of our study suggest that haloperidol suppresses the functional maturation of DCs and plays an important role in the inhibition of DC-induced T helper 1 immune responses in the whole animal. Furthermore, the effect of haloperidol on DCs may be mediated by

  20. Suppression of tumorigenicity and metastatic potential of melanoma cells by transduction of interferon gene

    Directory of Open Access Journals (Sweden)

    Lykhova A. A.

    2014-01-01

    Full Text Available The aim of this study was to investigate an inhibitory effect of baculovirus-mediated transduction of the murine interferon-beta gene on mouse melanoma in vitro and in vivo. Methods. Studies were performed on B16 mouse melanoma (MM-4 cell line. Transduction, immunocytochemical and tumor cell biology approaches have been used in this study. Results. Transduction of MM-4 cells by the recombinant baculovirus with IFN-beta gene is accompanied by morphological changes of tumor cells, suppression of cell proliferation, significant inhibition of platting efficiency of cells and their colonies formation in semisolid agar. Moreover, transduction of melanoma MM-4 cells by the baculovirus IFN-transgene leads to inhibition of tumorigenicity and metastatic ability of the cells in vivo. The intravenous administration of recombinant baculovirus vector with IFN gene inhibits growth of metastases induced in the lungs of mice by intravenously injected tumor cells. Conclusions. Transduction of mouse melanoma cells by the recombinant baculovirus with murine IFN-beta gene inhibits their proliferative potential, tumorigenicity and metastatic activity.

  1. Ndm, a coiled-coil domain protein that suppresses macropinocytosis and has effects on cell migration.

    Science.gov (United States)

    Kelsey, Jessica S; Fastman, Nathan M; Noratel, Elizabeth F; Blumberg, Daphne D

    2012-09-01

    The ampA gene has a role in cell migration in Dictyostelium discoideum. Cells overexpressing AmpA show an increase in cell migration, forming large plaques on bacterial lawns. A second-site suppressor of this ampA-overexpressing phenotype identified a previously uncharacterized gene, ndm, which is described here. The Ndm protein is predicted to contain a coiled-coil BAR-like domain-a domain involved in endocytosis and membrane bending. ndm-knockout and Ndm-monomeric red fluorescent protein-expressing cell lines were used to establish a role for ndm in suppressing endocytosis. An increase in the rate of endocytosis and in the number of endosomes was detected in ndm(-) cells. During migration ndm(-) cells formed numerous endocytic cups instead of the broad lamellipodia structure characteristic of moving cells. A second lamellipodia-based function-cell spreading-was also defective in the ndm(-) cells. The increase in endocytosis and the defect in lamellipodia formation were associated with reduced chemotaxis in ndm(-) cells. Immunofluorescence results and glutathione S-transferase pull-down assays revealed an association of Ndm with coronin and F-actin. The results establish ndm as a gene important in regulating the balance between formation of endocytic cups and lamellipodia structures.

  2. Prenylated Flavonoids from Cudrania tricuspidata Suppress Lipopolysaccharide-Induced Neuroinflammatory Activities in BV2 Microglial Cells

    Science.gov (United States)

    Kim, Dong-Cheol; Yoon, Chi-Su; Quang, Tran Hong; Ko, Wonmin; Kim, Jong-Su; Oh, Hyuncheol; Kim, Youn-Chul

    2016-01-01

    In Korea and China, Cudrania tricuspidata Bureau (Moraceae) is an important traditional medicinal plant used to treat lumbago, hemoptysis, and contusions. The C. tricuspidata methanol extract suppressed both production of NO and PGE2 in BV2 microglial cells. Cudraflavanone D (1), isolated from this extract, remarkably suppressed the protein expression of inducible NO synthase and cyclooxygenase-2, and decreased the levels of NO and PGE2 in BV2 microglial cells exposed to lipopolysaccharide. Cudraflavanone D (1) also decreased IL-6, TNF-α, IL-12, and IL-1β production, blocked nuclear translocation of NF-κB heterodimers (p50 and p65) by interrupting the degradation and phosphorylation of inhibitor of IκB-α, and inhibited NF-κB binding. In addition, cudraflavanone D (1) suppressed the phosphorylation of c-Jun N-terminal kinase (JNK) and p38 MAPK pathways. This study indicated that cudraflavanone D (1) can be a potential drug candidate for the cure of neuroinflammation. PMID:26907256

  3. Redundant mechanisms are involved in suppression of default cell fates during embryonic mesenchyme and notochord induction in ascidians.

    Science.gov (United States)

    Kodama, Hitoshi; Miyata, Yoshimasa; Kuwajima, Mami; Izuchi, Ryoichi; Kobayashi, Ayumi; Gyoja, Fuki; Onuma, Takeshi A; Kumano, Gaku; Nishida, Hiroki

    2016-08-01

    During embryonic induction, the responding cells invoke an induced developmental program, whereas in the absence of an inducing signal, they assume a default uninduced cell fate. Suppression of the default fate during the inductive event is crucial for choice of the binary cell fate. In contrast to the mechanisms that promote an induced cell fate, those that suppress the default fate have been overlooked. Upon induction, intracellular signal transduction results in activation of genes encoding key transcription factors for induced tissue differentiation. It is elusive whether an induced key transcription factor has dual functions involving suppression of the default fates and promotion of the induced fate, or whether suppression of the default fate is independently regulated by other factors that are also downstream of the signaling cascade. We show that during ascidian embryonic induction, default fates were suppressed by multifold redundant mechanisms. The key transcription factor, Twist-related.a, which is required for mesenchyme differentiation, and another independent transcription factor, Lhx3, which is dispensable for mesenchyme differentiation, sequentially and redundantly suppress the default muscle fate in induced mesenchyme cells. Similarly in notochord induction, Brachyury, which is required for notochord differentiation, and other factors, Lhx3 and Mnx, are likely to suppress the default nerve cord fate redundantly. Lhx3 commonly suppresses the default fates in two kinds of induction. Mis-activation of the autonomously executed default program in induced cells is detrimental to choice of the binary cell fate. Multifold redundant mechanisms would be required for suppression of the default fate to be secure. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Vorinostat induces reactive oxygen species and DNA damage in acute myeloid leukemia cells.

    Directory of Open Access Journals (Sweden)

    Luca A Petruccelli

    Full Text Available Histone deacetylase inhibitors (HDACi are promising anti-cancer agents, however, their mechanisms of action remain unclear. In acute myeloid leukemia (AML cells, HDACi have been reported to arrest growth and induce apoptosis. In this study, we elucidate details of the DNA damage induced by the HDACi vorinostat in AML cells. At clinically relevant concentrations, vorinostat induces double-strand breaks and oxidative DNA damage in AML cell lines. Additionally, AML patient blasts treated with vorinostat display increased DNA damage, followed by an increase in caspase-3/7 activity and a reduction in cell viability. Vorinostat-induced DNA damage is followed by a G2-M arrest and eventually apoptosis. We found that pre-treatment with the antioxidant N-acetyl cysteine (NAC reduces vorinostat-induced DNA double strand breaks, G2-M arrest and apoptosis. These data implicate DNA damage as an important mechanism in vorinostat-induced growth arrest and apoptosis in both AML cell lines and patient-derived blasts. This supports the continued study and development of vorinostat in AMLs that may be sensitive to DNA-damaging agents and as a combination therapy with ionizing radiation and/or other DNA damaging agents.

  5. Vorinostat Induces Reactive Oxygen Species and DNA Damage in Acute Myeloid Leukemia Cells

    Science.gov (United States)

    Pettersson, Filippa; Retrouvey, Hélène; Skoulikas, Sophia; Miller, Wilson H.

    2011-01-01

    Histone deacetylase inhibitors (HDACi) are promising anti-cancer agents, however, their mechanisms of action remain unclear. In acute myeloid leukemia (AML) cells, HDACi have been reported to arrest growth and induce apoptosis. In this study, we elucidate details of the DNA damage induced by the HDACi vorinostat in AML cells. At clinically relevant concentrations, vorinostat induces double-strand breaks and oxidative DNA damage in AML cell lines. Additionally, AML patient blasts treated with vorinostat display increased DNA damage, followed by an increase in caspase-3/7 activity and a reduction in cell viability. Vorinostat-induced DNA damage is followed by a G2-M arrest and eventually apoptosis. We found that pre-treatment with the antioxidant N-acetyl cysteine (NAC) reduces vorinostat-induced DNA double strand breaks, G2-M arrest and apoptosis. These data implicate DNA damage as an important mechanism in vorinostat-induced growth arrest and apoptosis in both AML cell lines and patient-derived blasts. This supports the continued study and development of vorinostat in AMLs that may be sensitive to DNA-damaging agents and as a combination therapy with ionizing radiation and/or other DNA damaging agents. PMID:21695163

  6. Ganoderma extract prevents albumin-induced oxidative damage and chemokines synthesis in cultured human proximal tubular epithelial cells.

    Science.gov (United States)

    Lai, Kar Neng; Chan, Loretta Y Y; Tang, Sydney C W; Leung, Joseph C K

    2006-05-01

    Ganoderma lucidum (Ganoderma or lingzhi) is widely used as an alternative medicine remedy to promote health and longevity. Recent studies have indicated that components extracted from Ganoderma have a wide range of pharmacological actions including suppressing inflammation and scavenging free radicals. We recently reported that tubular secretion of interleukin-8 (IL-8) induced by albumin is important in the pathogenesis of tubulointerstitial injury in the proteinuric state. In this study, we explored the protective effect of Ganoderma extract (LZ) on albumin-induced kidney epithelial injury. Growth arrested human proximal tubular epithelial cells (PTECs) were incubated with 0.625 to 10 mg/ml human serum albumin (HSA) for up to 72 h. HSA induced DNA damage and apoptosis in PTEC in a dose- and time-dependent manner. Co-incubation of PTEC with 4-64 microg/ml LZ significantly reduced the oxidative damage and cytotoxic effect of HSA in a dose-dependent manner (PGanoderma (16 microg/ml). To explore the components of LZ that exhibited most protective effect in HSA-induced PTEC damages, LZ was further separated into two sub-fractions, LZF1 (MW effective in reducing sICAM-1 released from HSA-activated PTEC whereas the high molecular weight LZ (unfractionated LZ) was more effective in diminishing IL-8 production. Our results suggest that Ganoderma significantly reduces oxidative damages and apoptosis in PTEC induced by HSA. The differential reduction of IL-8 or sICAM-1 released from HSA-activated PTEC by different components of the LZ implicates that components of Ganoderma with different molecular weights could play different roles and operate different mechanisms in preventing HSA-induced PTEC damage.

  7. Non-Destructive Detection and Separation of Radiation Damaged Cells in Miniaturized, Inexpensive Device Project

    Data.gov (United States)

    National Aeronautics and Space Administration — There is a clear and well-identified need for rapid, efficient, non-destructive detection and isolation of radiation damaged cells. Available commercial technologies...

  8. Non-Destructive Detection and Separation of Radiation Damaged Cells in Miniaturized, Inexpensive Device Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Our objective is to develop and demonstrate a novel microfluidic device for non-destructive identification, sorting and counting of radiation damaged cells. A major...

  9. Non-Destructive Detection and Separation of Radiation Damaged Cells in Miniaturized, Inexpensive Device, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — There is a clear and well-identified need for rapid, efficient, non-destructive detection and isolation of radiation damaged cells. Available commercial technologies...

  10. Targeted p53 activation by saRNA suppresses human bladder cancer cells growth and metastasis.

    Science.gov (United States)

    Wang, Chenghe; Ge, Qiangqiang; Zhang, Qingsong; Chen, Zhong; Hu, Jia; Li, Fan; Ye, Zhangqun

    2016-03-25

    Previous study showed that dsP53-285 has the capacity to induce tumor suppressor gene p53 expression by targeting promoter in non-human primates' cells. And it is well known that TP53 gene is frequently mutant or inactivated in human bladder cancer. Hereby, whether this small RNA can activate the expression of wild-type p53 and inhibit human bladder cancer cells remains to be elucidated. Oligonucleotide and lentivirus were used to overexpress dsP53-285 and dsControl. Real-time PCR and western blot were used to detect genes' mRNA and protein expression, respectively. Cell proliferation assay, colony formation, flow cytometry, transwell assay and wound healing assay were performed to determine the effects on bladder cancer cells proliferation and migration/invasion in vitro. Animal models were carried out to analyze the effects on cells growth and metastasis in vivo. Transfection of dsP53-285 into human bladder cancer cell lines T24 and EJ readily activate wild-type p53 expression by targeting promoter. Moreover, dsP53-285 exhibited robust capacity to inhibit cells proliferation and colony formation, induce cells G0/G1 arrest, suppress migration and invasion. Besides, the Cyclin-CDK genes (Cyclin D1 and CDK4/6) were down-regulated and the EMT-associated genes (E-cadherin, β-catenin, ZEB1 and Vimentin) were also expressed inversely after dsP53-285 treatment. In addition, dsP53-285 could also significantly suppress the growth of bladder cancer xenografts and metastasis in nude mice. Most importantly, the anti-tumor effects mediated by dsP53-285 were mainly achieved by manipulating wild-type p53 expression. Our findings indicate that the dsP53-285 can upregulate wild-type p53 expression in human bladder cancer cells through RNA activation, and suppresses cells proliferation and metastasis in vitro and in vivo.

  11. Arctigenin protects against liver injury from acute hepatitis by suppressing immune cells in mice.

    Science.gov (United States)

    Cheng, Xixi; Wang, Huafeng; Yang, Jinlai; Cheng, Yingnan; Wang, Dan; Yang, Fengrui; Li, Yan; Zhou, Dongmei; Wang, Yanxia; Xue, Zhenyi; Zhang, Lijuan; Zhang, Qi; Yang, Luhong; Zhang, Rongxin; Da, Yurong

    2018-03-23

    As a phenylpropanoid and dibenzylbutyrolactone lignan present in medical plants, such as those used in traditional Chinese herbal medicine, including Arctium lappa (Niubang), arctigenin exhibits antimicrobial, anti-inflammatory, and anticancer activities. In this study, we investigated the protective role of arctigenin in Concanavalin A (ConA)-induced acute hepatitis in mice. Arctigenin remarkably reduced the congestion and necroinflammation of livers, and improved hepatic function (ALT and AST) in ConA-induced acute hepatitis in vivo. The infiltration of CD4 T, NKT and macrophages into the livers was found to be reduced with arctigenin treatment. Arctigenin suppressed ConA-induced T lymphocyte proliferations that might have resulted from enhanced IL-10 production by macrophages and CD4 T cells. These results suggested that arctigenin could be a powerful drug candidate for acute hepatitis through immune suppression. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  12. Live cell microscopy of DNA damage response in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Pinela da Silva, Sonia Cristina; Gallina, Irene; Eckert-Boulet, Nadine Valerie

    2012-01-01

    live cell imaging allows for multiple cellular markers to be monitored over several hours. This chapter reviews useful fluorescent markers and genotoxic agents for studying the DNA damage response in living cells and provides protocols for live cell imaging, time-lapse microscopy, and for induction...

  13. Amifostine does not protect thyroid cancer cells in DNA damaging in vitro models

    Directory of Open Access Journals (Sweden)

    Joanna Klubo-Gwiezdzinska

    2017-09-01

    Full Text Available Background: Amifostine is a potent scavenger of reactive oxygen species that is used for the salivary gland protection during therapy with radioactive iodine for thyroid cancer. There are no data on the potential effect of amifostine on thyroid cancer cells. Methods: We investigated the effects of the active form of amifostine (WR-1065 on the response of thyroid cancer cells to treatment with DNA-damaging agents. WR-1065 was examined in human thyroid cancer cell lines (FTC133, TPC1, BCPAP and C643 and embryonic fibroblast cells NIH3T3. DNA damage was induced by exposure to H2O2 (0.1 mM, by treatment with the radiomimetic neocarzinostatin (NCS 250 ng/mL and by γ-radiation (6 Gy. DNA damage, cell viability and apoptosis were examined. Results: We demonstrated the selective action of WR-1065 (0.1 mM, which prevented oxidative stress–induced DNA damage in fibroblasts, but did not protect thyroid cancer cells from DNA damage and apoptosis documented by caspase-3 and PARP cleavage after exposure to H2O2, NCS and γ-radiation. Prolonged exposure to WR-1065 (0.1 mM for 24 h was toxic for thyroid cancer cells; this treatment decreased the number of viable cells by 8% in C643 cells, 47% in TPC cells, 92% in BCPAP cells and 82% in FTC 133 cells. The cytotoxic effects of WR-1065 were not associated with induction of apoptosis. Conclusions: Our data show that amifostine has no protective effect on thyroid cancer cells against DNA-damaging agents in vitro and suggest that amifostine will not attenuate the efficacy of radioiodine treatment in patients with thyroid cancer.

  14. Extracellular matrix induces doxorubicin-resistance in human osteosarcoma cells by suppression of p53 function.

    Science.gov (United States)

    Harisi, Revekka; Dudas, Jozsef; Nagy-Olah, Julia; Timar, Ferenc; Szendroi, Miklos; Jeney, Andras

    2007-08-01

    Osteosarcoma is the most common primary malignant bone tumor in childhood and adolescence. The several chemotherapy-resistant cases of osteosarcoma are at a higher risk of relapse and adverse outcome. The aim of the current study was to determine the role of extracellular matrix in the resistance developed against chemotherapeutic treatments of human osteosarcoma cells. A cell line, named OSCORT was established from the biopsy of a 17-year-old male patient with primary osteosarcoma. Cell proliferation, apoptosis and quantification of DNA damage after treatments with doxorubicin were investigated in classical and three-dimensional cell culture systems using an extracellular matrix gel. The experimental results were related to the clinical observations of the case. The cells cultured in extracellular matrix gel have shown resistance to doxorubicin similar to that seen in the clinical case, as demonstrated by their proliferation, apoptosis and doxorubicin-induced DNA damage characteristics. Among the extracellular matrix components, the heparan sulfate proteoglycan and-to a lesser extent-fibronectin were involved in the doxorubicin resistance. Laminin and nidogen did not decrease the cytoreductive effect of doxorubicin, while collagen IV even increased it. The extracellular matrix gel decreased the protein levels of p53 and abrogated its cell nuclear translocalization. The most frequent known mutations in the p53 gene were not found in OSCORT cells. The current study provides experimental evidence for an epigenetical, extracellular matrix-induced loss of p53 function, which lead to a potent chemotherapy resistance showing accordance with the clinical experience.

  15. miR-935 suppresses gastric signet ring cell carcinoma tumorigenesis by targeting Notch1 expression

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Chao [Department of General Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, 100730 (China); Yu, Jianchun, E-mail: yu_jchpumch@163.com [Department of General Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, 100730 (China); Kang, Weiming [Department of General Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, 100730 (China); Liu, Yuqin [Cell Culture Center, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100005 (China); Ma, Zhiqiang; Zhou, Li [Department of General Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, 100730 (China)

    2016-01-29

    Gastric signet ring cell carcinoma (GSRCC) is a unique pathological type of gastric carcinoma that is extremely invasive and has a poor prognosis. Expression of microRNAs (miRNAs) has been closely linked to the carcinogenesis of gastric cancer and has been considered as a powerful prognostic marker. The function of miR-935 has never been reported in cancer before. We found, using microRNA array, that expression of miR-935 in GSRCC cell lines is lower than in non-GSRCC cell lines, and enhanced expression of miR-935 in GSRCC cell-lines inhibit cell proliferation, migration and invasion. We also identified Notch1 as a direct target of miR-935. Knockdown of Notch1 reduced proliferation, migration/invasion of GSRCC cells, and overexpression Notch1's activated form (Notch intracellular domain) could rescue miR-935's tumor suppressive effect on GSRCC. Expression of miR-935 was lower in gastric carcinoma tissue than in paired normal tissue samples, and lower in GSRCC than in non-GSRCC. Our results demonstrate the inverse correlation between the expression of miR-935 and Notch1 in gastric tissues. We conclude that miR-935 inhibits gastric carcinoma cell proliferation, migration and invasion by targeting Notch1, suggesting potential applications of the miR-935-Notch1 pathway in gastric cancer clinical diagnosis and therapeutics, especially in gastric signet ring cell carcinoma. - Highlights: • The expression of miR-935 is lower in GC tissue than in paired normal tissue. • The expression of miR-935 is lower in GSRCC tissue than in non-GSRCC. • Enhanced expression of miR-935 suppresses tumorigenesis of GSRCC. • Notch1 is a direct target of miR-935.

  16. Transforming growth factor-β suppresses metastasis in a subset of human colon carcinoma cells

    International Nuclear Information System (INIS)

    Simms, Neka A K; Rajput, Ashwani; Sharratt, Elizabeth A; Ongchin, Melanie; Teggart, Carol A; Wang, Jing; Brattain, Michael G

    2012-01-01

    TGFβ signaling has typically been associated with suppression of tumor initiation while the role it plays in metastasis is generally associated with progression of malignancy. However, we present evidence here for an anti-metastatic role of TGFβ signaling. To test the importance of TGFβ signaling to cell survival and metastasis we compared human colon carcinoma cell lines that are either non-tumorigenic with TGFβ response (FET), or tumorigenic with TGFβ response (FETα) or tumorigenic with abrogated TGFβ response via introduction of dominant negative TGFβRII (FETα/DN) and their ability to metastasize. Metastatic competency was assessed by orthotopic transplantation. Metastatic colony formation was assessed histologically and by imaging. Abrogation of TGFβ signaling through introduction of a dominant negative TGFβ receptor II (TGFβRII) in non-metastatic FETα human colon cancer cells permits metastasis to distal organs, but importantly does not reduce invasive behavior at the primary site. Loss of TGFβ signaling in FETα-DN cells generated enhanced cell survival capabilities in response to cellular stress in vitro. We show that enhanced cellular survival is associated with increased AKT phosphorylation and cytoplasmic expression of inhibitor of apoptosis (IAP) family members (survivin and XIAP) that elicit a cytoprotective effect through inhibition of caspases in response to stress. To confirm that TGFβ signaling is a metastasis suppressor, we rescued TGFβ signaling in CBS metastatic colon cancer cells that had lost TGFβ receptor expression due to epigenetic repression. Restoration of TGFβ signaling resulted in the inhibition of metastatic colony formation in distal organs by these cells. These results indicate that TGFβ signaling has an important role in the suppression of metastatic potential in tumors that have already progressed to the stage of an invasive carcinoma. The observations presented here indicate a metastasis suppressor role for TGF

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

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    Xiuli Dan

    2016-07-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

  19. Behavioral experience induces zif268 expression in mature granule cells but suppresses its expression in immature granule cells

    Directory of Open Access Journals (Sweden)

    Kylie A. Huckleberry

    2015-08-01

    Full Text Available Thousands of neurons are born each day in the dentate gyrus (DG, but many of these cells die before reaching maturity. Both death and survival of adult-born neurons are regulated by neuronal activity in DG. The immediate-early gene (IEG zif268 is an important mediator of these effects, as its expression is induced by neural activity and knockout of zif268 impairs survival of adult-born neurons (Veyrac et al., 2013. Despite the apparent importance of zif268 for adult neurogenesis, its behavior-induced expression has not been fully characterized in adult-born neurons. Here we characterize behavior-evoked expression of zif268 in mature and newborn dentate granule cells (DGCs. In the general granule cell population, zif268 expression peaked 1 hour after novel environment exposure and returned to baseline by 8 hours post-exposure. However, in the doublecortin-positive (DCX+ immature neurons, zif268 expression was suppressed relative to home cage for at least 8 hours post-exposure. We next determined that exposure to water maze training, an enriched environment, or a novel environment caused approximately equal suppression of zif268 expression in DCX+ cells and approximately equal activation of zif268 in the general DGC population and in 6-week-old adult-born neurons. Finally, we asked whether zif268 suppression varied as a function of age within the DCX+ population, which ranges in age from 0 to approximately 4 weeks. Novel environment exposure had no significant effect on zif268 expression in 2- or 4-week-old BrdU-labeled neurons, but it significantly suppressed zif268 expression in 3-week-old neurons. In summary, behavioral experience transiently activated expression of zif268 in mature DGCs but caused a more long-lasting suppression of zif268 expression in immature, adult-born DGCs. We hypothesize that zif268 suppression inhibits memory-related synaptic plasticity in immature DGCs or mediates learning-induced apoptosis of immature adult

  20. Molecular mechanism of intracellular lipid accumulation: Suppressive effect of PycnogenolR in liver cells

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    Shoichiro Ikuyama

    2013-09-01

    Full Text Available ABSTRACTCells are physiologically ready to accumulate lipids such as triacylglycerides in the cytoplasm.Five classes of perilipin (PLIN family proteins are known to be involved in the process of intracellular lipid accumulation. PLIN2 is expressed ubiquitously including adipocytes, hepatocytes and macrophages. Over-expression of PLIN2 is demonstrated in the lesions of fatty liver diseases and atherosclerosis. Suppression of PLIN2 expression prevents from developing these pathological conditions in animal models, suggesting that PLIN2 could be a therapeutic target molecule for excessive intracellular lipid accumulation which leads to various metabolic derangements. The PLIN2 gene promoter has two important cis-acting elements in close proximity:AP-1 element which mediates inflammatory signals and PPRE which mediates free fatty acid effect. In NMuLi mouse liver cells, FFA such as oleic acid requires both functional AP-1 and PPRE simultaneously to stimulate the promoter activity, indicating the presence of intimate interaction of inflammatory and metabolic signals on this gene. PycnogenolR, French maritime pine bark extracts, suppressed the oleic acid-induced PLIN2 expression and lipid accumulation in NMuLi cells. We found that PycnogenolR did not suppress the PLIN2 promoter activity or AP-1 binding to DNA. Instead, PycnogenolRfacilitates the PLIN2 mRNA degradation, leading to suppression of lipid accumulation. This effect seems to be independent of antioxidant effect of PycnogenolR.We raise the idea that PLIN2 is a putative target molecule for prevention of pathological condition induced by excessive lipid accumulation, and this class of natural compounds could be putative therapeutic modalities.Key words: PycnogenolR, lipid droplet, perilipin, fatty liver disease

  1. Proapoptotic PUMA targets stem-like breast cancer cells to suppress metastasis

    Science.gov (United States)

    Sun, Qi; Lesperance, Jacqueline; Wettersten, Hiromi; Luterstein, Elaine; DeRose, Yoko S.; Welm, Alana; Cheresh, David A.; Desgrosellier, Jay S.

    2017-01-01

    Breast cancer cells with stem cell properties are key contributors to metastatic disease, and there remains a need to better understand and target these cells in human cancers. Here, we identified rare stem-like cells in patients’ tumors characterized by low levels of the proapoptotic molecule p53-upregulated modulator of apoptosis (PUMA) and showed that these cells play a critical role in tumor progression that is independent of clinical subtype. A signaling axis consisting of the integrin αvβ3, Src kinase, and the transcription factor Slug suppresses PUMA in these cells, promoting tumor stemness. We showed that genetic or pharmacological disruption of αvβ3/Src signaling drives PUMA expression, specifically depleting these stem-like tumor cells; increases their sensitivity to apoptosis; and reduces pulmonary metastasis, with no effect on primary tumor growth. Taken together, these findings point to PUMA as a key vulnerability of stem-like cells and suggest that pharmacological upregulation of PUMA via Src inhibition may represent a strategy to selectively target these cells in a wide spectrum of aggressive breast cancers. PMID:29227280

  2. Endothelial cells suppress monocyte activation through secretion of extracellular vesicles containing antiinflammatory microRNAs.

    Science.gov (United States)

    Njock, Makon-Sébastien; Cheng, Henry S; Dang, Lan T; Nazari-Jahantigh, Maliheh; Lau, Andrew C; Boudreau, Emilie; Roufaiel, Mark; Cybulsky, Myron I; Schober, Andreas; Fish, Jason E

    2015-05-14

    The blood contains high concentrations of circulating extracellular vesicles (EVs), and their levels and contents are altered in several disease states, including cardiovascular disease. However, the function of circulating EVs, especially the microRNAs (miRNAs) that they contain, are poorly understood. We sought to determine the effect of secreted vesicles produced by quiescent endothelial cells (ECs) on monocyte inflammatory responses and to assess whether transfer of microRNAs occurs between these cells. We observed that monocytic cells cocultured (but not in contact) with ECs were refractory to inflammatory activation. Further characterization revealed that endothelium-derived EVs (EC-EVs) suppressed monocyte activation by enhancing immunomodulatory responses and diminishing proinflammatory responses. EVs isolated from mouse plasma also suppressed monocyte activation. Importantly, injection of EC-EVs in vivo repressed monocyte/macrophage activation, confirming our in vitro findings. We found that several antiinflammatory microRNAs were elevated in EC-EV-treated monocytes. In particular, miR-10a was transferred to monocytic cells from EC-EVs and could repress inflammatory signaling through the targeting of several components of the NF-κB pathway, including IRAK4. Our findings reveal that ECs secrete EVs that can modulate monocyte activation and suggest that altered EV secretion and/or microRNA content may affect vascular inflammation in the setting of cardiovascular disease. © 2015 by The American Society of Hematology.

  3. TAp63 suppress metastasis via miR-133b in colon cancer cells.

    Science.gov (United States)

    Lin, C W; Li, X R; Zhang, Y; Hu, G; Guo, Y H; Zhou, J Y; Du, J; Lv, L; Gao, K; Zhang, Y; Deng, H

    2014-04-29

    TAp63 is a tumour-suppressor protein that is often underexpressed in various types of cancer. It has been shown to activate gene transcription depending on the transcription domain and to be closely related with metastasis. In this study, we demonstrate that TAp63 suppresses metastasis in colon cancer cells through microRNA-133b. We evaluated the correlation of TAp63 and miR-133b with HT-29 and SW-620 cells and investigated the roles of TAp63 in the expression of RhoA, E-cadherin and vimentin. We further investigated the roles of TAp63-mediated invasion and migration of colon cancer cells. TAp63 expression is downregulated in colon cancer, and microRNA-133b is a transcriptional target of TAp63. Furthermore, microRNA-133b is essential for the inhibitory effects of TAp63 on RhoA, E-cadherin and vimentin. Moreover, TAp63 inhibits cell migration and invasion through microRNA-133b. Correspondingly, the inhibitory effect of TAp63 on RhoA, E-cadherin, vimentin, migration and invasion can be blocked by the microRNA-133b inhibitor. TAp63 and microRNA-133b were able to suppress the metastasis of colon cancer. Both TAp63 and microRNA-133b may be potential biomarkers for diagnosis in colon cancer metastasis and may provide unique therapeutic targets for this common malignancy.

  4. Suppression of vapor cell temperature error for spin-exchange-relaxation-free magnetometer

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Jixi, E-mail: lujixi@buaa.edu.cn; Qian, Zheng; Fang, Jiancheng; Quan, Wei [School of Instrument Science and Opto-Electronics Engineering, Beihang University, Beijing 100191 (China)

    2015-08-15

    This paper presents a method to reduce the vapor cell temperature error of the spin-exchange-relaxation-free (SERF) magnetometer. The fluctuation of cell temperature can induce variations of the optical rotation angle, resulting in a scale factor error of the SERF magnetometer. In order to suppress this error, we employ the variation of the probe beam absorption to offset the variation of the optical rotation angle. The theoretical discussion of our method indicates that the scale factor error introduced by the fluctuation of the cell temperature could be suppressed by setting the optical depth close to one. In our experiment, we adjust the probe frequency to obtain various optical depths and then measure the variation of scale factor with respect to the corresponding cell temperature changes. Our experimental results show a good agreement with our theoretical analysis. Under our experimental condition, the error has been reduced significantly compared with those when the probe wavelength is adjusted to maximize the probe signal. The cost of this method is the reduction of the scale factor of the magnetometer. However, according to our analysis, it only has minor effect on the sensitivity under proper operating parameters.

  5. Emodin and Aloe-Emodin Suppress Breast Cancer Cell Proliferation through ERα Inhibition

    Science.gov (United States)

    Huang, Pao-Hsuan; Huang, Chih-Yang; Chen, Mei-Chih; Lee, Yueh-Tsung; Yue, Chia-Herng; Wang, Hsin-Yi

    2013-01-01

    The anthraquinones emodin and aloe-emodin are abundant in rhubarb. Several lines of evidence indicate that emodin and aloe-emodin have estrogenic activity as phytoestrogens. However, their effects on estrogen receptor α (ERα) activation and breast cancer cell growth remain controversial. The goal of this study is to investigate the effects and molecular mechanisms of emodin and aloe-emodin on breast cancer cell proliferation. Our results indicate that both emodin and aloe-emodin are capable of inhibiting breast cancer cell proliferation by downregulating ERα protein levels, thereby suppressing ERα transcriptional activation. Furthermore, aloe-emodin treatment led to the dissociation of heat shock protein 90 (HSP90) and ERα and increased ERα ubiquitination. Although emodin had similar effects to aloe-emodin, it was not capable of promoting HSP90/ERα dissociation and ERα ubiquitination. Protein fractionation results suggest that aloe-emodin tended to induce cytosolic ERα degradation. Although emodin might induce cytosolic ERα degradation, it primarily affected nuclear ERα distribution similar to the action of estrogen when protein degradation was blocked. In conclusion, our data demonstrate that emodin and aloe-emodin specifically suppress breast cancer cell proliferation by targeting ERα protein stability through distinct mechanisms. These findings suggest a possible application of anthraquinones in preventing or treating breast cancer in the future. PMID:23864887

  6. Tetrandrine suppresses pro-inflammatory mediators in PMA plus A23187-induced HMC-1 cells.

    Science.gov (United States)

    Kang, Ok-Hwa; An, Hyeon-Jin; Kim, Sung-Bae; Mun, Su-Hyun; Seo, Yun-Soo; Joung, Dae-Ki; Choi, Jang-Gi; Shin, Dong-Won; Kwon, Dong-Yeul

    2014-05-01

    Tetrandrine (TET), a bis-benzylisoquinoline alkaloid from the root of Stephania tetrandra, is known to possess antitumor activity in various malignant neoplasms. However, the precise mechanism of TET-mediated immune modulation remains to be clarified. One of the possible mechanisms for its protective properties is by downregulation of the inflammatory responses. In the present study, the human mast cell line (HMC-1) was used to investigate this effect. TET significantly inhibited the induction of inflammatory cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-8 by phorbol 12-myristate 13-acetate (PMA) plus A23187. Moreover, TET attenuated expression of cyclooxygenase (COX)-2. In activated HMC-1 cells, the phosphorylation of extra-signal response kinase (ERK1/2) and c-jun N-terminal Kinase (JNK1/2), but not p38 mitogen-activated protein kinase, was decreased by treatment of the cells with TET. TET inhibited PMA plus A23187-induced nuclear factor (NF)-κB activation, IκB degradation and phosphorylation. Furthermore, TET suppressed the expression of TNF-α, IL-8, IL-6 and COX-2 through suppression of the ERK1/2, JNK1/2, IκBα degradation and phosphorylation, and NF-κB activation. These results indicated that TET exerted a regulatory effect on inflammatory reactions mediated by mast cells.

  7. Ndel1 suppresses ciliogenesis in proliferating cells by regulating the trichoplein-Aurora A pathway.

    Science.gov (United States)

    Inaba, Hironori; Goto, Hidemasa; Kasahara, Kousuke; Kumamoto, Kanako; Yonemura, Shigenobu; Inoko, Akihito; Yamano, Shotaro; Wanibuchi, Hideki; He, Dongwei; Goshima, Naoki; Kiyono, Tohru; Hirotsune, Shinji; Inagaki, Masaki

    2016-02-15

    Primary cilia protrude from the surface of quiescent cells and disassemble at cell cycle reentry. We previously showed that ciliary reassembly is suppressed by trichoplein-mediated Aurora A activation pathway in growing cells. Here, we report that Ndel1, a well-known modulator of dynein activity, localizes at the subdistal appendage of the mother centriole, which nucleates a primary cilium. In the presence of serum, Ndel1 depletion reduces trichoplein at the mother centriole and induces unscheduled primary cilia formation, which is reverted by forced trichoplein expression or coknockdown of KCTD17 (an E3 ligase component protein for trichoplein). Serum starvation induced transient Ndel1 degradation, subsequent to the disappearance of trichoplein at the mother centriole. Forced expression of Ndel1 suppressed trichoplein degradation and axonemal microtubule extension during ciliogenesis, similar to trichoplein induction or KCTD17 knockdown. Most importantly, the proportion of ciliated and quiescent cells was increased in the kidney tubular epithelia of newborn Ndel1-hypomorphic mice. Thus, Ndel1 acts as a novel upstream regulator of the trichoplein-Aurora A pathway to inhibit primary cilia assembly. © 2016 Inaba et al.

  8. The Fusarium oxysporum effector Six6 contributes to virulence and suppresses I-2-mediated cell death.

    Science.gov (United States)

    Gawehns, F; Houterman, P M; Ichou, F Ait; Michielse, C B; Hijdra, M; Cornelissen, B J C; Rep, M; Takken, F L W

    2014-04-01

    Plant pathogens secrete effectors to manipulate their host and facilitate colonization. Fusarium oxysporum f. sp. lycopersici is the causal agent of Fusarium wilt disease in tomato. Upon infection, F. oxysporum f. sp. lycopersici secretes numerous small proteins into the xylem sap (Six proteins). Most Six proteins are unique to F. oxysporum, but Six6 is an exception; a homolog is also present in two Colletotrichum spp. SIX6 expression was found to require living host cells and a knockout of SIX6 in F. oxysporum f. sp. lycopersici compromised virulence, classifying it as a genuine effector. Heterologous expression of SIX6 did not affect growth of Agrobacterium tumefaciens in Nicotiana benthamiana leaves or susceptibility of Arabidopsis thaliana toward Verticillium dahliae, Pseudomonas syringae, or F. oxysporum, suggesting a specific function for F. oxysporum f. sp. lycopersici Six6 in the F. oxysporum f. sp. lycopersici- tomato pathosystem. Remarkably, Six6 was found to specifically suppress I-2-mediated cell death (I2CD) upon transient expression in N. benthamiana, whereas it did not compromise the activity of other cell-death-inducing genes. Still, this I2CD suppressing activity of Six6 does not allow the fungus to overcome I-2 resistance in tomato, suggesting that I-2-mediated resistance is independent from cell death.

  9. ATG7 deficiency suppresses apoptosis and cell death induced by lysosomal photodamage

    Science.gov (United States)

    Kessel, David H.; Price, Michael; Reiners, Jr., John J.

    2012-01-01

    Photodynamic therapy (PDT) involves photosensitizing agents that, in the presence of oxygen and light, initiate formation of cytotoxic reactive oxygen species (ROS). PDT commonly induces both apoptosis and autophagy. Previous studies with murine hepatoma 1c1c7 cells indicated that loss of autophagy-related protein 7 (ATG7) inhibited autophagy and enhanced the cytotoxicity of photosensitizers that mediate photodamage to mitochondria or the endoplasmic reticulum. In this study, we examined two photosensitizing agents that target lysosomes: the chlorin NPe6 and the palladium bacteriopheophorbide WST11. Irradiation of wild-type 1c1c7 cultures loaded with either photosensitizer induced apoptosis and autophagy, with a blockage of autophagic flux. An ATG7- or ATG5-deficiency suppressed the induction of autophagy in PDT protocols using either photosensitizer. Whereas ATG5-deficient cells were quantitatively similar to wild-type cultures in their response to NPe6 and WST11 PDT, an ATG7-deficiency suppressed the apoptotic response (as monitored by analyses of chromatin condensation and procaspase-3/7 activation) and increased the LD50 light dose by > 5-fold (as monitored by colony-forming assays). An ATG7-deficiency did not prevent immediate lysosomal photodamage, as indicated by loss of the lysosomal pH gradient. However, unlike wild-type and ATG5-deficient cells, the lysosomes of ATG7-deficient cells recovered this gradient within 4 h of irradiation, and never underwent permeabilization (monitored as release of endocytosed 10-kDa dextran polymers). We propose that the efficacy of lysosomal photosensitizers is in part due to both promotion of autophagic stress and suppression of autophagic prosurvival functions. In addition, an effect of ATG7 unrelated to autophagy appears to modulate lysosomal photodamage. PMID:22889762

  10. Micro RNA-98 suppresses interleukin-10 in peripheral B cells in patient post-cardio transplantation.

    Science.gov (United States)

    Song, Jiangping; Su, Wenjun; Chen, Xiao; Zhao, Qian; Zhang, Ningning; Li, Mao-Gang; Yang, Ping-Chang; Wang, Liqing

    2017-04-25

    The immune tolerance to the transplant heart survival is critical. Regulatory B cells are one of the major immune regulatory cell populations in the immune tolerance. Micro RNAs (miR) can regulate the activities of immune cells, such as the expression of interleukin (IL)-10 by B cells. This study tests a hypothesis that micro RNA (miR)-98 plays a role in the regulation of interleukin (IL)-10 expression in B cells (B10 cell) after heart transplantation. In this study, the peripheral blood samples were collected from patients before and after heart transplantation. The expression of miR-98 and IL-10 in B cells was assessed by real time RT-PCR. An allograft heart transplantation mouse model was developed. We observed that after heart transplantation, the frequency of peripheral B10 cell and the IL-10 mRNA levels in peripheral B cells were significantly decreased, the levels of miR-98 were increased in peripheral B cells and the serum levels of cortisol were increased in the patients. Treating naive B cells with cortisol in the culture suppressed the expression of IL-10 in B cells, which was abolished by knocking down the miR-98 gene. Administration with anti-miR-98, or cortisol inhibitor, or adoptive transfer with B10 cells, significantly enhanced the survival rate and time of mice received allograft heart transplantation. In conclusion, the enhancement of serum cortisol affects the immune tolerant feature of B cells, which can be attenuated by anti-miR-98-carrying liposomes.

  11. Suppression of a Natural Killer Cell Response by Simian Immunodeficiency Virus Peptides.

    Directory of Open Access Journals (Sweden)

    Jamie L Schafer

    2015-09-01

    Full Text Available Natural killer (NK cell responses in primates are regulated in part through interactions between two highly polymorphic molecules, the killer-cell immunoglobulin-like receptors (KIRs on NK cells and their major histocompatibility complex (MHC class I ligands on target cells. We previously reported that the binding of a common MHC class I molecule in the rhesus macaque, Mamu-A1*002, to the inhibitory receptor Mamu-KIR3DL05 is stabilized by certain simian immunodeficiency virus (SIV peptides, but not by others. Here we investigated the functional implications of these interactions by testing SIV peptides bound by Mamu-A1*002 for the ability to modulate Mamu-KIR3DL05+ NK cell responses. Twenty-eight of 75 SIV peptides bound by Mamu-A1*002 suppressed the cytolytic activity of primary Mamu-KIR3DL05+ NK cells, including three immunodominant CD8+ T cell epitopes previously shown to stabilize Mamu-A1*002 tetramer binding to Mamu-KIR3DL05. Substitutions at C-terminal positions changed inhibitory peptides into disinhibitory peptides, and vice versa, without altering binding to Mamu-A1*002. The functional effects of these peptide variants on NK cell responses also corresponded to their effects on Mamu-A1*002 tetramer binding to Mamu-KIR3DL05. In assays with mixtures of inhibitory and disinhibitory peptides, low concentrations of inhibitory peptides dominated to suppress NK cell responses. Consistent with the inhibition of Mamu-KIR3DL05+ NK cells by viral epitopes presented by Mamu-A1*002, SIV replication was significantly higher in Mamu-A1*002+ CD4+ lymphocytes co-cultured with Mamu-KIR3DL05+ NK cells than with Mamu-KIR3DL05- NK cells. These results demonstrate that viral peptides can differentially affect NK cell responses by modulating MHC class I interactions with inhibitory KIRs, and provide a mechanism by which immunodeficiency viruses may evade NK cell responses.

  12. Effect of superposed electromagnetic noise on DNA damage of lens epithelial cells induced by microwave radiation.

    Science.gov (United States)

    Yao, Ke; Wu, Wei; Yu, Yibo; Zeng, Qunli; He, Jiliang; Lu, Deqiang; Wang, Kaijun

    2008-05-01

    To investigate the influence of the 1.8-GHz radiofrequency fields (RFs) of the Global System for Mobile Communications on DNA damage, intracellular reactive oxygen species (ROS) formation, cell cycle, and apoptosis in human lens epithelial cells (hLECs) and whether the effects induced by RF could be blocked by superposing of electromagnetic noise. After 24-hour intermittent exposure at the specific absorption rate of 1 W/kg, 2 W/kg, 3 W/kg, and 4 W/kg, the DNA damage of hLECs was examined by alkaline comet assay and immunofluorescence microscope detection of the phosphorylated form of histone variant H2AX (gammaH2AX) foci, respectively. ROS production was quantified by the fluorescent probe 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA). Cell cycle and cell apoptosis were determined by flow cytometry. DNA damage examined by alkaline comet assay was significantly increased after 3 W/kg and 4 W/kg radiation (P radiation (P microwave radiation and sham exposure groups (P > 0.05). All the effects mentioned were blocked when the RF was superposed with 2 muT electromagnetic noise. Microwave radiation induced hLEC DNA damage after G(0)/G(1) arrest does not lead to cell apoptosis. The increased ROS observed may be associated with DNA damage. Superposed electromagnetic noise blocks microwave radiation-induced DNA damage, ROS formation, and cell cycle arrest.

  13. Depletion layer recombination effects on the radiation damage hardness of gallium arsenide cells

    Science.gov (United States)

    Garlick, G. F. J.

    1985-01-01

    The significant effect of junction depletion layer recombination on the efficiency of windowed GaAs cells was demonstrated. The effect becomes more pronounced as radiation damage occurs. The depletion is considered for 1 MeV electron fluences up to 10 to the 16th power e/sq m. The cell modeling separates damage in emitter and base or buffer layers using different damage coefficients is reported. The lower coefficient for the emitter predicts less loss of performance at fluences greater than 10 to the 15th power e/sq cm. A method for obtaining information on junction recombination effects as damage proceeds is described; this enables a more complete diagnosis of damage to be made.

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

  15. Morin, a flavonoid from Moraceae, suppresses growth and invasion of the highly metastatic breast cancer cell line MDA-MB‑231 partly through suppression of the Akt pathway.

    Science.gov (United States)

    Jin, Hana; Lee, Won Sup; Eun, So Young; Jung, Ji Hyun; Park, Hyeon-Soo; Kim, Gonsup; Choi, Yung Hyun; Ryu, Chung Ho; Jung, Jin Myung; Hong, Soon Chan; Shin, Sung Chul; Kim, Hye Jung

    2014-10-01

    Morin, a flavonoid found in figs and other Moraceae, displays a variety of biological actions, such as anti-oxidant, anti-inflammatory and anti-carcinogenic. However, the anticancer effects of morin and in particular its anti-metastatic effects are not well known. Therefore, in the present study, we investigated the anticancer effects of morin on highly metastatic human breast cancer cells. Our results showed that morin significantly inhibited the colony forming ability of highly metastatic MDA-MB‑231 breast cancer cells from low doses (50 µM) without cytotoxicity. In addition, morin changed MDA-MB‑231 cell morphology from mesenchymal shape to epithelial shape and inhibited the invasion of MDA-MB‑231 cells in a dose-dependent manner. Morin decreased matrix metalloproteinase-9 (MMP-9) secretion and expression of the mesenchymal marker N-cadherin of MDA-MB‑231 cells, suggesting that morin might suppress the EMT process. Furthermore, morin significantly decreased the phosphorylation of Akt, and inhibition of the Akt pathway significantly reduced MDA-MB‑231 invasion. In an in vivo xenograft mouse model, morin suppressed MDA-MB‑231 cancer cell progression. Taken together, our findings suggest that morin exhibits an inhibitory effect on the cancer progression and EMT process of highly metastatic breast cancer cells at least in part through inhibiting Akt activation. This study provides evidence that morin may have anticancer effects against metastatic breast cancer.

  16. Selenium supplementation restores the antioxidative capacity and prevents cell damage in bone marrow stromal cells in vitro

    DEFF Research Database (Denmark)

    Ebert, Regina; Ulmer, Matthias; Zeck, Sabine

    2006-01-01

    signaling, cumulative cell damage, senescence, and tumor development. Selenium-dependent (glutathione peroxidases [GPxs] and thioredoxin reductases [TrxRs]) and selenium-independent (superoxide dismutases [SODs] and catalase [CAT]) enzyme systems regulate cellular ROS steady state levels. SODs process...

  17. LIVER AND BONE MARROW STEM/PROGENITOR CELLS AS REGULATORS OF REPARATIVE REGENERATION OF DAMAGED LIVER

    Directory of Open Access Journals (Sweden)

    А. V. Lundup

    2010-01-01

    Full Text Available In this review the modern information about effectiveness of liver insufficiency treatment by stem/ progenitor cells of liver (oval cells and bone marrow (hemopoietic cells and mesenchymal cells was presented. It is shown that medical action of these cells is referred on normalization of liver cell interaction and reorganization of processes of a reparative regeneration in damaged liver. It is believed that application of mesenchymal stromal cells from an autological bone marrow is the most perspective strategy. However, for definitive judgement about regenerative possibilities of the autological bone marrow cells it is necessary to carry out large-scale double blind clinical researches. 

  18. Processing of radiation-induced clustered DNA damage generates DSB in mammalian cells

    International Nuclear Information System (INIS)

    Gulston, M.K.; De Lara, C.M.; Davis, E.L.; Jenner, T.J.; O'Neill, P.

    2003-01-01

    Full text: Clustered DNA damage sites, in which two or more lesions are formed within a few helical turns of the DNA after passage of a single radiation track, are signatures of DNA modifications induced by ionizing radiation in mammalian cell. With 60 Co-radiation, the abundance of clustered DNA damage induced in CHO cells is ∼4x that of prompt double strand breaks (DSB) determined by PFGE. Less is known about the processing of non-DSB clustered DNA damage induced in cells. To optimize observation of any additional DSB formed during processing of DNA damage at 37 deg C, xrs-5 cells deficient in non-homologous end joining were used. Surprisingly, ∼30% of the DSB induced by irradiation at 37 deg C are rejoined within 4 minutes in both mutant and wild type cells. No significant mis-repair of these apparent DSB was observed. It is suggested that a class of non-DSB clustered DNA damage is formed which repair correctly within 4 min but, if 'trapped' prior to repair, are converted into DSB during the lysis procedure of PFGE. However at longer times, a proportion of non-DSB clustered DNA damage sites induced by γ-radiation are converted into DSB within ∼30 min following post-irradiation incubation at 37 deg C. The corresponding formation of additional DSB was not apparent in wild type CHO cells. From these observations, it is estimated that only ∼10% of the total yield of non DSB clustered DNA damage sites are converted into DSB through cellular processing. The biological consequences that the majority of non-DSB clustered DNA damage sites are not converted into DSBs may be significant even at low doses, since a finite chance exists of these clusters being formed in a cell by a single radiation track

  19. Plasma Molecular Signatures in Hypertensive Patients With Renin-Angiotensin System Suppression: New Predictors of Renal Damage and De Novo Albuminuria Indicators.

    Science.gov (United States)

    Baldan-Martin, Montserrat; Mourino-Alvarez, Laura; Gonzalez-Calero, Laura; Moreno-Luna, Rafael; Sastre-Oliva, Tamara; Ruiz-Hurtado, Gema; Segura, Julian; Lopez, Juan Antonio; Vazquez, Jesus; Vivanco, Fernando; Alvarez-Llamas, Gloria; Ruilope, Luis M; de la Cuesta, Fernando; Barderas, Maria G

    2016-07-01

    Albuminuria is a risk factor strongly associated with cardiovascular disease, the first cause of death in the general population. It is well established that renin-angiotensin system suppressors prevent the development of new-onset albuminuria in naïf hypertensive patients and diminish its excretion, but we cannot forget the percentage of hypertensive patients who develop de novo albuminuria. Here, we applied multiple proteomic strategy with the purpose to elucidate specific molecular pathways involved in the pathogenesis and provide predictors and chronic organ damage indicators. Briefly, 1143 patients were followed up for a minimum period of 3 years. One hundred and twenty-nine hypertensive patients chronically renin-angiotensin system suppressed were recruited, classified in 3 different groups depending on their albuminuria levels (normoalbuminuria, de novo albuminuria, and sustained albuminuria), and investigated by multiple proteomic strategies. Our strategy allowed us to perform one of the deepest plasma proteomic analysis to date, which has shown 2 proteomic signatures: (1) with predictive value of de novo albuminuria and (2) sustained albuminuria indicator proteins. These proteins are involved in inflammation, immune as well as in the proteasome activation occurring in situations of endoplasmic reticulum stress. Furthermore, these results open the possibility of a future strategy based on anti-immune therapy to treat hypertension which could help to prevent the development of albuminuria and, hence, the progression of kidney damage. © 2016 American Heart Association, Inc.

  20. Antibody-mediated allotype suppression in adult mice: the role of antigen, effector isotype and regulatory T cells.

    Science.gov (United States)

    Curling, E M; Dresser, D W

    1984-10-01

    It has been reported (Contemp. Top. Immunobiol. 1974. 3:41) that allotype-specific T suppressor cells can be induced after monoclonal anti-allotype treatment of neonatal (BALB/c X SJL)F1 (Igha/b) mice. Here we show that (BALB/c X CB20)F1 adult-derived spleen cells (SC) are, by contrast, potently suppressed by monoclonal allotype-specific reagents, (when transferred into irradiated BALB/c recipients) in the absence of primary T suppressor cell induction. Such suppression is only induced in activated B cells [exposed to lipopolysaccharide or sheep red blood cells (SRBC)], and is probably dependent on the isotype of the anti-allotype sera administered. For example, two independently produced IgG1 monoclonal reagents raised against the Igh-1b allotype were poorly suppressive or nonsuppressive, whereas an IgG3 and an IgG2a monoclonal antibody induced a 90% suppression of the target allotype in transferred adult SC. It was found that suppression was not due to a depletion of antigen-specific T cell help since: (a) the addition of SRBC-educated T cells did not break suppression and (b) suppressed SC were as good a source of T cell help as normal SC, in the response of virgin or memory B cell (Thy-1-depleted) responses to SRBC in vivo. Suppression was maintained in suppressed cells which had been rechallenged with SRBC after transfer into a second irradiated recipient, but was not induced in normal SC when these were admixed with an equal number from this suppressed SC population. These findings point to a possible mechanism for the regulation of B cell expression, through the formation of an antibody-Ig receptor complex at the surface of the B lymphocyte. After complexing the target cell is either deleted or inactivated. The response to SRBC was reduced or ablated for at least 70 days after treatment with a single dose of anti-allotype serum.

  1. Cell type-specific suppression of mechanosensitive genes by audible sound stimulation.

    Science.gov (United States)

    Kumeta, Masahiro; Takahashi, Daiji; Takeyasu, Kunio; Yoshimura, Shige H

    2018-01-01

    Audible sound is a ubiquitous environmental factor in nature that transmits oscillatory compressional pressure through the substances. To investigate the property of the sound as a mechanical stimulus for cells, an experimental system was set up using 94.0 dB sound which transmits approximately 10 mPa pressure to the cultured cells. Based on research on mechanotransduction and ultrasound effects on cells, gene responses to the audible sound stimulation were analyzed by varying several sound parameters: frequency, wave form, composition, and exposure time. Real-time quantitative PCR analyses revealed a distinct suppressive effect for several mechanosensitive and ultrasound-sensitive genes that were triggered by sounds. The effect was clearly observed in a wave form- and pressure level-specific manner, rather than the frequency, and persisted for several hours. At least two mechanisms are likely to be involved in this sound response: transcriptional control and RNA degradation. ST2 stromal cells and C2C12 myoblasts exhibited a robust response, whereas NIH3T3 cells were partially and NB2a neuroblastoma cells were completely insensitive, suggesting a cell type-specific response to sound. These findings reveal a cell-level systematic response to audible sound and uncover novel relationships between life and sound.

  2. Total triterpenoids from Ganoderma Lucidum suppresses prostate cancer cell growth by inducing growth arrest and apoptosis.

    Science.gov (United States)

    Wang, Tao; Xie, Zi-ping; Huang, Zhan-sen; Li, Hao; Wei, An-yang; Di, Jin-ming; Xiao, Heng-jun; Zhang, Zhi-gang; Cai, Liu-hong; Tao, Xin; Qi, Tao; Chen, Di-ling; Chen, Jun

    2015-10-01

    In this study, one immortalized human normal prostatic epithelial cell line (BPH) and four human prostate cancer cell lines (LNCaP, 22Rv1, PC-3, and DU-145) were treated with Ganoderma Lucidum triterpenoids (GLT) at different doses and for different time periods. Cell viability, apoptosis, and cell cycle were analyzed using flow cytometry and chemical assays. Gene expression and binding to DNA were assessed using real-time PCR and Western blotting. It was found that GLT dose-dependently inhibited prostate cancer cell growth through induction of apoptosis and cell cycle arrest at G1 phase. GLT-induced apoptosis was due to activation of Caspases-9 and -3 and turning on the downstream apoptotic events. GLT-induced cell cycle arrest (mainly G1 arrest) was due to up-regulation of p21 expression at the early time and down-regulation of cyclin-dependent kinase 4 (CDK4) and E2F1 expression at the late time. These findings demonstrate that GLT suppresses prostate cancer cell growth by inducing growth arrest and apoptosis, which might suggest that GLT or Ganoderma Lucidum could be used as a potential therapeutic drug for prostate cancer.

  3. A DNA vector-based RNAi technology to suppress gene expression in mammalian cells.

    Science.gov (United States)

    Sui, Guangchao; Soohoo, Christina; Affar, El Bachir; Gay, Frédérique; Shi, Yujiang; Forrester, William C; Shi, Yang

    2002-04-16

    Double-stranded RNA-mediated interference (RNAi) has recently emerged as a powerful reverse genetic tool to silence gene expression in multiple organisms including plants, Caenorhabditis elegans, and Drosophila. The discovery that synthetic double-stranded, 21-nt small interfering RNA triggers gene-specific silencing in mammalian cells has further expanded the utility of RNAi into mammalian systems. Here we report a technology that allows synthesis of small interfering RNAs from DNA templates in vivo to efficiently inhibit endogenous gene expression. Significantly, we were able to use this approach to demonstrate, in multiple cell lines, robust inhibition of several endogenous genes of diverse functions. These findings highlight the general utility of this DNA vector-based RNAi technology in suppressing gene expression in mammalian cells.

  4. Flowers from Kalanchoe pinnata are a rich source of T cell-suppressive flavonoids.

    Science.gov (United States)

    Coutinho, Marcela A S; Muzitano, Michelle F; Cruz, Elaine A; Bergonzi, Maria C; Kaiser, Carlos R; Tinoco, Luzineide W; Bilia, Anna R; Vincieric, Franco F; Rossi-Bergmann, Bartira; Costa, Sônia S

    2012-02-01

    The chemical composition and immunosuppressive potential of the flowers from Kalanchoe pinnata (Crassulaceae) were investigated. We found that the aqueous flower extract was more active than the leaf extract in inhibiting murine T cell mitogenesis in vitro. Flavonoids isolated from the flower extract were identified and quantitated based on NMR and HPLC-DAD-MS analysis, respectively. Along with quercetin, four quercetin glycosyl conjugates were obtained, including quercetin 3-O-beta-D-glucuronopyranoside and quercetin 3-O-beta-D-glucopyranoside, which are described for the first time in K. pinnata. All flavonoids inhibited murine T cell mitogenesis and IL-2 and IL-4 production without cell toxicity. This is the first report on the pharmacological activity of flowers of a Kalanchoe species, which are not used for curative purposes. Our findings show that K. pinnata flowers are a rich source of T-suppressive flavonoids that may be therapeutically useful against inflammatory diseases.

  5. Spiclomazine induces apoptosis associated with the suppression of cell viability, migration and invasion in pancreatic carcinoma cells.

    Directory of Open Access Journals (Sweden)

    Wenjing Zhao

    Full Text Available The effective treatment for pancreatic carcinoma remains critically needed. Herein, this current study showed that spiclomazine treatment caused a reduction in viability in pancreatic carcinoma cell lines CFPAC-1 and MIA PaCa-2 in vitro. It was notable in this regard that, compared with pancreatic carcinoma cells, normal human embryonic kidney (HEK-293 and liver (HL-7702 cells were more resistant to the antigrowth effect of spiclomazine. Biochemically, spiclomazine treatment regulated the expression of protein levels in the apoptosis related pathways. Consistent with this effect, spiclomazine reduced the mitochondria membrane potential, elevated reactive oxygen species, and activated caspase-3/9. In addition, a key finding from this study was that spiclomazine suppressed migration and invasion of cancer cells through down-regulation of MMP-2/9. Collectively, the proposed studies did shed light on the antiproliferation effect of spiclomazine on pancreatic carcinoma cell lines, and further clarified the mechanisms that spiclomazine induced apoptosis associated with the suppression of migration and invasion.

  6. Exosomes from Human Dental Pulp Stem Cells Suppress Carrageenan-Induced Acute Inflammation in Mice.

    Science.gov (United States)

    Pivoraitė, Ugnė; Jarmalavičiūtė, Akvilė; Tunaitis, Virginijus; Ramanauskaitė, Giedrė; Vaitkuvienė, Aida; Kašėta, Vytautas; Biziulevičienė, Genė; Venalis, Algirdas; Pivoriūnas, Augustas

    2015-10-01

    The primary goal of this study was to examine the effects of human dental pulp stem cell-derived exosomes on the carrageenan-induced acute inflammation in mice. Exosomes were purified by differential ultracentrifugation from the supernatants of stem cells derived from the dental pulp of human exfoliated deciduous teeth (SHEDs) cultivated in serum-free medium. At 1 h post-carrageenan injection, exosomes derived from supernatants of 2 × 10(6) SHEDs were administered by intraplantar injection to BALB/c mice; 30 mg/kg of prednisolone and phosphate-buffered saline (PBS) were used as positive and negative controls, respectively. Edema was measured at 6, 24, and 48 h after carrageenan injection. For the in vivo imaging experiments, AngioSPARK750, Cat B 750 FAST, and MMPSense 750 FAST were administered into the mouse tail vein 2 h post-carrageenan injection. Fluorescence images were acquired at 6, 24, and 48 h after edema induction by IVIS Spectrum in vivo imaging system. Exosomes significantly reduced the carrageenan-induced edema at all the time points studied (by 39.5, 41.6, and 25.6% at 6, 24, and 48 h after injection, respectively), to similar levels seen with the positive control (prednisolone). In vivo imaging experiments revealed that, both exosomes and prednisolone suppress activities of cathepsin B and matrix metalloproteinases (MMPs) at the site of carrageenan-induced acute inflammation, showing more prominent effects of prednisolone at the early stages, while exosomes exerted their suppressive effects gradually and at later time points. Our study demonstrates for the first time that exosomes derived from human dental pulp stem cells suppress carrageenan-induced acute inflammation in mice.

  7. Secondary Metabolites from Fungal Endophytes of Echinacea purpurea Suppress Cytokine Secretion by Macrophage-Type Cells

    Science.gov (United States)

    Kaur, Amninder; Oberhofer, Martina; Juzumaite, Monika; Raja, Huzefa A.; Gulledge, Travis V.; Kao, Diana; Faeth, Stanley H.; Laster, Scott M.; Oberlies, Nicholas H.

    2017-01-01

    Botanical extracts of Echinacea purpurea have been widely used for the treatment of upper respiratory infections. We sought to chemically examine fungal endophytes inhabiting E. purpurea, and to identify compounds produced by these endophytes with in vitro cytokine-suppressive activity. Twelve isolates from surface sterilized seeds of E. purpurea were subjected to fractionation and major components were isolated. Sixteen secondary metabolites belonging to different structural classes were identified from these isolates based on NMR and mass spectrometry data. The compounds were tested for their influence on cytokine secretion by murine macrophage-type cells. Alternariol (1), O-prenylporriolide (4), porritoxin (10) β-zearalenol (13), and (S)-zearalenone (14) inhibited production of TNF-α from RAW 264.7 macrophages stimulated with LPS in the absence of any significant cytotoxicity. This is the first report of a cytokine-suppressive effect for 4. The results of this study are particularly interesting given that they show the presence of compounds with cytokine-suppressive activity in endophytes from a botanical used to treat inflammation. Future investigations into the role of fungal endophytes in the biological activity of E. purpurea dietary supplements may be warranted. PMID:28479944

  8. Obesity Suppresses Estrogen Receptor Beta Expression in Breast Cancer Cells via a HER2-Mediated Pathway.

    Science.gov (United States)

    Bowers, Laura W; Wiese, Megan; Brenner, Andrew J; Rossi, Emily L; Tekmal, Rajeshwar R; Hursting, Stephen D; deGraffenried, Linda A

    2015-01-01

    Obesity is associated with a worse breast cancer prognosis, while greater breast tumor estrogen receptor beta (ERβ) expression is correlated with improved therapy response and survival. The objective of this study was to determine the impact of obesity on breast cancer cell ERβ expression, which is currently unknown. We utilized an in vitro model of obesity in which breast cancer cells were exposed to patient serum pooled by body mass index category (obese (OB): ≥30 kg/m2; normal weight (N): 18.5-24.9 kg/m2). Four human mammary tumor cell lines representing the major breast cancer subtypes (SKBR3, MCF-7, ZR75, MDA-MB-231) and mammary tumor cells from MMTV-neu mice were used. ERβ expression, assessed by qPCR and western blotting, was suppressed in the two HER2-overexpressing cell lines (SKBR3, MMTV-neu) following OB versus N sera exposure, but did not vary in the other cell lines. Expression of Bcl-2 and cyclin D1, two genes negatively regulated by ERβ, was elevated in SKBR3 cells following exposure to OB versus N sera, but this difference was eliminated when the ERβ gene was silenced with siRNA. Herceptin, a HER2 antagonist, and siRNA to HER2 were used to evaluate the role of HER2 in sera-induced ERβ modulation. SKBR3 cell treatment with OB sera plus Herceptin increased ERβ expression three-fold. Similar results were obtained when HER2 expression was silenced with siRNA. OB sera also promoted greater SKBR3 cell viability and growth, but this variance was not present when ERβ was silenced or the cells were modified to overexpress ERβ. Based on this data, we conclude that obesity-associated systemic factors suppress ERβ expression in breast cancer cells via a HER2-mediated pathway, leading to greater cell viability and growth. Elucidation of the mechanism(s) mediating this effect could provide important insights into how ERβ expression is regulated as well as how obesity promotes a more aggressive disease.

  9. Obesity Suppresses Estrogen Receptor Beta Expression in Breast Cancer Cells via a HER2-Mediated Pathway.

    Directory of Open Access Journals (Sweden)

    Laura W Bowers

    Full Text Available Obesity is associated with a worse breast cancer prognosis, while greater breast tumor estrogen receptor beta (ERβ expression is correlated with improved therapy response and survival. The objective of this study was to determine the impact of obesity on breast cancer cell ERβ expression, which is currently unknown. We utilized an in vitro model of obesity in which breast cancer cells were exposed to patient serum pooled by body mass index category (obese (OB: ≥30 kg/m2; normal weight (N: 18.5-24.9 kg/m2. Four human mammary tumor cell lines representing the major breast cancer subtypes (SKBR3, MCF-7, ZR75, MDA-MB-231 and mammary tumor cells from MMTV-neu mice were used. ERβ expression, assessed by qPCR and western blotting, was suppressed in the two HER2-overexpressing cell lines (SKBR3, MMTV-neu following OB versus N sera exposure, but did not vary in the other cell lines. Expression of Bcl-2 and cyclin D1, two genes negatively regulated by ERβ, was elevated in SKBR3 cells following exposure to OB versus N sera, but this difference was eliminated when the ERβ gene was silenced with siRNA. Herceptin, a HER2 antagonist, and siRNA to HER2 were used to evaluate the role of HER2 in sera-induced ERβ modulation. SKBR3 cell treatment with OB sera plus Herceptin increased ERβ expression three-fold. Similar results were obtained when HER2 expression was silenced with siRNA. OB sera also promoted greater SKBR3 cell viability and growth, but this variance was not present when ERβ was silenced or the cells were modified to overexpress ERβ. Based on this data, we conclude that obesity-associated systemic factors suppress ERβ expression in breast cancer cells via a HER2-mediated pathway, leading to greater cell viability and growth. Elucidation of the mechanism(s mediating this effect could provide important insights into how ERβ expression is regulated as well as how obesity promotes a more aggressive disease.

  10. Surmounting tumor-induced immune suppression by frequent vaccination or immunization in the absence of B cells.

    Science.gov (United States)

    Oizumi, Satoshi; Deyev, Vadim; Yamazaki, Koichi; Schreiber, Taylor; Strbo, Natasa; Rosenblatt, Joseph; Podack, Eckhard R

    2008-05-01

    Tumor-induced immune suppression is one of the most difficult obstacles to the success of tumor immunotherapy. Here, we show that established tumors suppress CD8 T cell clonal expansion in vivo, which is normally observed in tumor-free mice upon antigen-specific glycoprotein (gp) 96-chaperone vaccination. Suppression of CD8 T-cell expansion by established tumors is independent of tumor-associated expression of the antigen that is recognized by the CD8-T-cell receptor. Vaccination of tumor-bearing mice is associated with increased cellular recruitment to the vaccine site compared with tumor-free mice. However, rejection of established, suppressive tumors required frequent (daily) gp96 vaccination. B cells are known to attenuate T helper cell-1 responses. We found that in B-cell deficient mice, tumor rejection of established tumors can be achieved by a single vaccination. Accordingly, in tumor-free B-cell deficient mice, cognate CD8 cytotoxic T lymphocyte clonal expansion is enhanced in response to gp96-chaperone vaccination. The data have implications for the study of tumor-induced immune suppression and for translation of tumor immunotherapy into the clinical setting. Frequent vaccination with cellular vaccines and concurrent B-cell depletion may greatly enhance the activity of anticancer vaccine therapy in patients.

  11. Berberine Suppresses Cell Motility Through Downregulation of TGF-β1 in Triple Negative Breast Cancer Cells

    Directory of Open Access Journals (Sweden)

    Sangmin Kim

    2018-01-01

    Full Text Available Background/Aims: Transforming growth factor-beta proteins (TGF-βs are multifunctional growth factors and powerful modulators of the epithelial-mesenchymal transition (EMT in a variety of cancer types including breast and lung cancer cells. Here, we demonstrated the inhibitory effect of berberine (BBR on tumor growth and metastasis of triple negative breast cancer (TNBC cells via suppression of TGF-β1 expression. Methods: The levels of mRNA expression were analyzed by real-time PCR. The levels of MMP-2, MMP-9 and TGF-β1 protein expression were analyzed by zymography and confocal microscopy, respectively. Cell migration was analyzed by wound healing assay. Tumorigenicity of TNBC cells such as tumor growth and metastasis was analyzed using xenograft models. Results: In a clinical data set, aberrant TGF-β1 expression was associated with poor prognosis of breast cancer patients. Our in vitro results using TNBC cells showed that the expression levels of matrix metalloproteinase (MMP-2 and MMP-9 and the capacity for cell migration were increased by TGF-β1 treatment. In contrast, basal levels of MMP-2 and MMP-9 were suppressed by a specific TGF-β receptor I inhibitor, SB431542. In addition, TGF-β1–induced MMP-2 and MMP-9 expression and cell migration were decreased by SB431542. Interestingly, we showed for the first time that BBR decreased the level of TGF-β1, but not TGF-β2, in TNBC cells. Furthermore, BBR significantly decreased the level of MMP-2 expression as well as the capacity for cell migration in TNBC cells. Finally, we examined the effect of BBR on in vivo tumor growth and lung metastasis in MDA-MB231 and 4T1 breast cancer xenograft models and showed that both were significantly decreased following BBR treatment. Conclusion: BBR suppresses tumorigenicity of TNBC cells through inhibition of TGF-β1 expression. Therefore, we demonstrate that BBR could be a promising drug for treatment of TNBC.

  12. Synergistic Effect of Hyperglycemia and Suppression on Adult Mouse Islet Beta Cell Replication

    Directory of Open Access Journals (Sweden)

    Szu-Tah Chen

    2012-01-01

    Full Text Available The complementary role of hyperglycemia and suppression on islet beta cell regeneration was investigated in a syngeneic mouse model. gene silencing was performed by infecting islets of C57BL/6 with shRNA lentiviral particles. At 54 hours after viral infection, protein content in cultured targeting islets was 22% of that in freshly isolated islets. Six days after transplantation to diabetic mice, targeting islet graft had considerably more cells with Ki67-staining nuclei than nontargeting islets. The mice in the targeting-islet group had a significantly shorter duration of temporary hyperglycaemia than mice in the non-targeting-islet group. The long-term ex vivo beneficial effect of silencing on graft function was also indicated by the significantly higher cumulative cure rate for diabetes in mice receiving 200 targeting islets than that in mice receiving 200 non-targeting islets. Our data suggest that hyperglycemia and persistent suppression have a synergistic effect on islet beta cell replication in adult mice.

  13. Non-canonical Glucocorticoid Receptor Transactivation of gilz by Alcohol Suppresses Cell Inflammatory Response

    Directory of Open Access Journals (Sweden)

    Hang Pong Ng

    2017-06-01

    Full Text Available Acute alcohol exposure suppresses cell inflammatory response. The underlying mechanism has not been fully defined. Here we report that alcohol was able to activate glucocorticoid receptor (GR signaling in the absence of glucocorticoids (GCs and upregulated glucocorticoid-induced leucine zipper (gilz, a prominent GC-responsive gene. Such a non-canonical activation of GR was not blocked by mifepristone, a potent GC competitor. The proximal promoter of gilz, encompassing five GC-responsive elements (GREs, was incorporated and tested in a luciferase reporter system. Deletion and/or mutation of the GREs abrogated the promoter responsiveness to alcohol. Thus, the GR–GRE interaction transduced the alcohol action on gilz. Alcohol induced GR nuclear translocation, which was enhanced by the alcohol dehydrogenase inhibitor fomepizole, suggesting that it was alcohol, not its metabolites, that engendered the effect. Gel mobility shift assay showed that unliganded GR was able to bind GREs and such interaction withstood clinically relevant levels of alcohol. GR knockout via CRISPR/Cas9 gene targeting or GILZ depletion via small RNA interference diminished alcohol suppression of cell inflammatory response to LPS. Thus, a previously unrecognized, non-canonical GR activation of gilz is involved in alcohol modulation of cell immune response.

  14. Disulfiram suppresses growth of the malignant pleural mesothelioma cells in part by inducing apoptosis.

    Directory of Open Access Journals (Sweden)

    Vino T Cheriyan

    Full Text Available Dithiocarbamate compound Disulfiram (DSF that binds with copper and functions as an inhibitor of aldehyde dehydrogenase is a Food and Drug Administration approved agent for treatment of alcoholism. Copper complexed DSF (DSF-Cu also possesses anti-tumor and chemosensitizing properties; however, its molecular mechanisms of action remain unclear. Here we investigated malignant pleural mesothelioma (MPM suppressive effects of DSF-Cu and the molecular mechanisms involved. DSF-Cu inhibited growth of the murine as well as human MPM cells in part by increasing levels of ubiquitinated proteins. DSF-Cu exposure stimulated apoptosis in MPM cells that involved activation of stress-activated protein kinases (SAPKs p38 and JNK1/2, caspase-3, and cleavage of poly-(ADP-ribose-polymerase, as well as increased expression of sulfatase 1 and apoptosis transducing CARP-1/CCAR1 protein. Gene-array based analyses revealed that DSF-Cu suppressed cell growth and metastasis-promoting genes including matrix metallopeptidase 3 and 10. DSF inhibited MPM cell growth and survival by upregulating cell cycle inhibitor p27Kip1, IGFBP7, and inhibitors of NF-κB such as ABIN 1 and 2 and Inhibitory κB (IκBα and β proteins. DSF-Cu promoted cleavage of vimentin, as well as serine-phosphorylation and lysine-63 linked ubiquitination of podoplanin. Administration of 50 mg/kg DSF-Cu by daily i.p injections inhibited growth of murine MPM cell-derived tumors in vivo. Although podoplanin expression often correlates with metastatic disease and poor prognosis, phosphorylation of serines in cytoplasmic domain of podoplanin has recently been shown to interfere with cellular motility and migration signaling. Post-translational modification of podoplanin and cleavage of vimentin by DSF-Cu underscore a metastasis inhibitory property of this agent and together with our in vivo studies underscore its potential as an anti-MPM agent.

  15. Betahistine attenuates murine collagen-induced arthritis by suppressing both inflammatory and Th17 cell responses.

    Science.gov (United States)

    Tang, Kuo-Tung; Chao, Ya-Hsuan; Chen, Der-Yuan; Lim, Yun-Ping; Chen, Yi-Ming; Li, Yi-Rong; Yang, Deng-Ho; Lin, Chi-Chen

    2016-10-01

    The objective of this study was to evaluate the potential therapeutic effects of betahistine dihydrochloride (betahistine) in a collagen-induced arthritis (CIA) mouse model. CIA was induced in DBA/1 male mice by primary immunization with 100μl of emulsion containing 2mg/ml chicken type II collagen (CII) mixed with complete Freund's adjuvant (CFA) in an 1:1 ratio, and booster immunization with 100μl of emulsion containing 2mg/ml CII mixed with incomplete Freund's adjuvant (IFA) in an 1:1 ratio. Immunization was performed subcutaneously at the base of the tail. After being boosted on day 21, betahistine (1 and 5mg/kg) was orally administered daily for 2weeks. The severity of CIA was determined by arthritic scores and assessment of histopathological joint destruction. Expression of cytokines in the paw and anti-CII antibodies in the serum was evaluated by ELISA. The proliferative response against CII in the lymph node cells was measured by (3)H-thymidine incorporation assay. The frequencies of different CII specific CD4(+) T cell subsets in the lymph node were determined by flow-cytometric analysis. Betahistine treatment attenuated the severity of arthritis and reduced the levels of pro-inflammatory cytokines, including TNF-α, IL-6, IL-23 and IL-17A, in the paw tissues of CIA mice. Lymph node cells from betahistine-treated mice showed a decrease in proliferation, as well as a lower frequency of Th17 cells. In vitro, betahistine suppressed CD4(+) T cell differentiation into Th17 cells. These results indicate that betahistine is effective in suppressing both inflammatory and Th17 responses in mouse CIA and that it may have therapeutic value as an adjunct treatment for rheumatoid arthritis. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Repeated exposures to roadside particulate matter extracts suppresses pulmonary defense mechanisms, resulting in lipid and protein oxidative damage.

    Science.gov (United States)

    Pardo, Michal; Porat, Ziv; Rudich, Assaf; Schauer, James J; Rudich, Yinon

    2016-03-01

    Exposure to particulate matter (PM) pollution in cities and urban canyons can be harmful to the exposed population. However, the underlying mechanisms that lead to health effects are not yet elucidated. It is postulated that exposure to repeated, small, environmentally relevant concentrations can affect lung homeostasis. This study examines the impact of repeated exposures to urban PM on mouse lungs with focus on inflammatory and oxidative stress parameters. Aqueous extracts from collected urban PM were administered to mice by 5 repeated intra-tracheal instillations (IT). Multiple exposures, led to an increase in cytokine levels in both bronchoalveolar lavage fluid and in the blood serum, indicating a systemic reaction. Lung mRNA levels of antioxidant/phase II detoxifying enzymes decreased by exposure to the PM extract, but not when metals were removed by chelation. Finally, disruption of lung tissue oxidant-inflammatory/defense balance was evidenced by increased levels of lipid and protein oxidation. Unlike response to a single IT exposure to the same dose and source of extract, multiple exposures result in lung oxidative damage and a systemic inflammatory reaction. These could be attributed to compromised capacity to activate the protective Nrf2 tissue defense system. It is suggested that water-soluble metals present in urban PM, potentially from break and tire wear, may constitute major drivers of the pulmonary and systemic responses to multiple exposure to urban PM. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Suppression of IL-8 production from airway cells by tiotropium bromide in vitro

    Directory of Open Access Journals (Sweden)

    Suzaki I

    2011-09-01

    Full Text Available Isao Suzaki1, Kazuhito Asano2, Yusuke Shikama3, Taisuke Hamasaki1, Ayako Kanei1, Harumi Suzaki11Department of Otorhinolaryngology, School of Medicine, Showa University, Tokyo, Japan; 2Division of Physiology, School of Nursing and Rehabilitation Sciences, Showa University, Yokohama, Japan; 3Department of Respiratory Diseases, Showa University Northern Yokohama Hospital, Yokohama, JapanBackground: COPD is characterized by persistent and progressive airway inflammation. Although neutrophilic airway inflammation is generally accepted to be a major factor in the pathogenesis of COPD, the influence of the agents used for the treatment of COPD on neutrophil functions such as chemotaxis is not fully understood.Purpose: The present study aimed to examine the influence of tiotropium bromide on the production of interleukin (IL-8 from human airway epithelial cells and lung fibroblasts (LFs after lipopolysaccharide (LPS stimulation in vitro.Methods: BEAS-2B cells, human bronchial epithelial cell line, and LFs, at a concentration of 5 × 105 cells/mL, were stimulated with LPS in the presence of various concentrations of tiotropium bromide. IL-8 in culture supernatants was examined by enzyme-linked immunosorbent assay (ELISA. IL-8 messenger ribonucleic acid (mRNA expression was examined by real-time polymerase chain reaction. The influence of tiotropium bromide on LPS-induced signaling pathways was also analyzed by examining nuclear factor-kappa (NF-κB activation and signaling protein phosphorylation by ELISA.Results: Tiotropium bromide at >15 pg/mL inhibited IL-8 production from both BEAS-2B cells and LFs after LPS stimulation. Tiotropium bromide also suppressed IL-8 mRNA expression through the inhibition of NF-κB activation and signaling protein, extracellular-signal-regulated kinase 1/2, and c-Jun N-terminal kinase, phosphorylation.Conclusion: The present results strongly suggest that tiotropium bromide exerts the inhibitory effect on neutrophilic

  18. DNA Damage in CD133-Positive Cells in Barrett’s Esophagus and Esophageal Adenocarcinoma

    Directory of Open Access Journals (Sweden)

    Raynoo Thanan

    2016-01-01

    Full Text Available Barrett’s esophagus (BE caused by gastroesophageal reflux is a major risk factor of Barrett’s esophageal adenocarcinoma (BEA, an inflammation-related cancer. Chronic inflammation and following tissue damage may activate progenitor cells under reactive oxygen/nitrogen species-rich environment. We previously reported the formation of oxidative/nitrative stress-mediated mutagenic DNA lesions, 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG and 8-nitroguanine, in columnar epithelial cells of BE tissues and cancer cells of BEA tissues. We investigated the mechanisms of BEA development in relation to oxidative/nitrative DNA damage and stem cell hypothesis. We examined 8-nitroguanine and 8-oxodG formation and the expression of stem cell marker (CD133 in biopsy specimens of patients with BE and BEA by immunohistochemical analysis in comparison with those of normal subjects. CD133 was detected at apical surface of columnar epithelial cells of BE and BEA tissues, and the cytoplasm and cell membrane of cancer cells in BEA tissues. DNA lesions and CD133 were colocalized in columnar epithelial cells and cancer cells. Their relative staining intensities in these tissues were significantly higher than those in normal subjects. Our results suggest that BE columnar epithelial cells with CD133 expression in apical surface undergo inflammation-mediated DNA damage, and mutated cells acquire the property of cancer stem cells with cytoplasmic CD133 expression.

  19. Vanillin Suppresses Cell Motility by Inhibiting STAT3-Mediated HIF-1α mRNA Expression in Malignant Melanoma Cells.

    Science.gov (United States)

    Park, Eun-Ji; Lee, Yoon-Mi; Oh, Taek-In; Kim, Byeong Mo; Lim, Beong-Ou; Lim, Ji-Hong

    2017-03-01

    Recent studies have shown that vanillin has anti-cancer, anti-mutagenic, and anti-metastatic activity; however, the precise molecular mechanism whereby vanillin inhibits metastasis and cancer progression is not fully elucidated. In this study, we examined whether vanillin has anti-cancer and anti-metastatic activities via inhibition of hypoxia-inducible factor-1α (HIF-1α) in A2058 and A375 human malignant melanoma cells. Immunoblotting and quantitative real time (RT)-PCR analysis revealed that vanillin down-regulates HIF-1α protein accumulation and the transcripts of HIF-1α target genes related to cancer metastasis including fibronectin 1 ( FN1 ), lysyl oxidase-like 2 ( LOXL2 ), and urokinase plasminogen activator receptor ( uPAR ). It was also found that vanillin significantly suppresses HIF-1α mRNA expression and de novo HIF-1α protein synthesis. To understand the suppressive mechanism of vanillin on HIF-1α expression, chromatin immunoprecipitation was performed. Consequently, it was found that vanillin causes inhibition of promoter occupancy by signal transducer and activator of transcription 3 (STAT3), but not nuclear factor-κB (NF-κB), on HIF1A . Furthermore, an in vitro migration assay revealed that the motility of melanoma cells stimulated by hypoxia was attenuated by vanillin treatment. In conclusion, we demonstrate that vanillin might be a potential anti-metastatic agent that suppresses metastatic gene expression and migration activity under hypoxia via the STAT3-HIF-1α signaling pathway.

  20. Chromosomal in situ suppression hybridization of immunologically classified mitotic cells in hematologic malignancies

    OpenAIRE

    Tiainen, Marianne; Knuutila, Sakari; Popp, Susanne; Emmerich, Patricia; Cremer, Thomas; Parlier, Valerie; Jotterand Bellomo, Martine; Ruutu, Tapani

    1992-01-01

    Chromosomal in situ suppression (CISS) hybridization was performed with library DNA from sorted human chromosomes 8, 9, 15, 17, 21, and 22 on immunologically stained bone marrow cells of four patients with a hematologic neoplasm, including two patients with myelodysplastic syndrome and trisomy 8, one patient with promyelocytic leukemia bearing the translocation t(15;17)(q22;q11-12), and one patient with chronic myeloid leukemia and the translocation t(9;22)(q34;q11). In all patients, the resu...

  1. Mefloquine damage vestibular hair cells in organotypic cultures.

    Science.gov (United States)

    Yu, Dongzhen; Ding, Dalian; Jiang, Haiyan; Stolzberg, Daniel; Salvi, Richard

    2011-07-01

    Mefloquine is an effective and widely used anti-malarial drug; however, some clinical reports suggest that it can cause dizziness, balance, and vestibular disturbances. To determine if mefloquine might be toxic to the vestibular system, we applied mefloquine to organotypic cultures of the macula of the utricle from postnatal day 3 rats. The macula of the utricle was micro-dissected out as a flat surface preparation and cultured with 10, 50, 100, or 200 μM mefloquine for 24 h. Specimens were stained with TRITC-conjugated phalloidin to label the actin in hair cell stereocilia and TO-PRO-3 to visualize cell nuclei. Some utricles were also labeled with fluorogenic caspase-3, -8, or -9 indicators to evaluate the mechanism of programmed cell death. Mefloquine treatment caused a dose-dependent loss of utricular hair cells. Treatment with 10 μM caused a slight reduction, 50 μM caused a significant reduction, and 200 μM destroyed nearly all the hair cells. Hair cell nuclei in mefloquine-treated utricles were condensed and fragmented, morphological features of apoptosis. Mefloquine-treated utricles were positive for the extrinsic initiator caspase-8 and intrinsic initiator caspase-9 and downstream executioner caspase-3. These results indicate that mefloquine can induce significant hair cell degeneration in the postnatal rat utricle and that mefloquine-induced hair cell death is initiated by both caspase-8 and caspase-9.

  2. Comparison of Genotoxic Damage in Monolayer Cell and Three-Dimensional Tissue-Like Cell Assemblies

    Science.gov (United States)

    Behravesh, E.; Emami, K.; Wu, H.; Gonda, S.

    Risk assessment for the biological effects of high-energy charged particles, ranging from protons to iron nuclei, encountered in space is essential for the success of long-term space exploration. While prokaryotic and eukaryotic cell models, developed in our lab and others, have advanced our understanding of many aspects of genotoxicity, there is a need for in vitro models to assess the risk to humans from space radiation insults that are representative of the cellular interactions present in tissues and capable of quantifying genotoxic damage. Toward this overall goal, the objective of this study is to examine the effect of the localized microenvironment of cells, either cultured as 2-dimensional monolayers (2D) or 3-dimensional aggregates (3D), on the rate and type of genotoxic damage, and to examine those effects after the normal cell repair processes. Rodent transgenic cell lines containing 50-70 copies of a transgene were utilized to provide the enhanced sensitivity required to enable the identification and quantification of the types of mutational events incurred from exposure to iron charged particles which makes up a significant portion of Space radiation. Although the LacI target of this system is ~1000 bps, each copy of the entire construct is over 45 kbps. The utilization of this system allows for the quantification of mutational frequency and type for the LacI target as well as assessment of DNA damage for the entire 45 kbp construct. The samples were exposed to high-LET iron charged particles at Brookhaven National Laboratory's AGS/NSRL facilities for a total dose of 0, 0.1, 0.25, 0.5, 1.0, and 2.0 Gy and recovered after 0, 1, and 7 days of tissue culture post-irradiation. The mutational frequency was found to be greater for the 3D samples when compared to the 2D samples at all doses. In addition, there was increased mutational frequency with 7 days culture post irradiation when compared to samples analyzed immediately after exposure. DNA sequencing of

  3. Cholera toxin inhibits human hepatocarcinoma cell proliferation in vitro via suppressing ATX/LPA axis.

    Science.gov (United States)

    Xia, Qi; Deng, An-mei; Wu, Shan-shan; Zheng, Min

    2011-08-01

    To investigate the antitumor effect of cholera toxin (CT) in hepatocellular carcinoma (HCC) in vitro and the mechanisms underlying the effect. Human hepatocellular carcinoma cell lines Hep3B and Huh7, which expressed moderate and high level of autotaxin (ATX), respectively, were used. Cytokine level in the cells was evaluated using ELISA assay, and cell proliferation was investigated using MTT assay. ATX expression was determined using Western blot. ATX/lyso-PLD activity in the conditioned medium was measured using FS-3, a fluorescent lysophosphatidylcholine (LPC) analogue, as substrate. Exposure to CT (7.5 and 10 ng/mL) significantly inhibited the cell growth, decreased secretion of proinflammatory cytokine TNF-α and promoted secretion of anti-inflammatory cytokines IL-4 and IL-10. CT at 10 ng/mL markedly suppressed ATX expression in Hep3B and Huh7 cells. Furthermore, ATX and lysophosphatidic acid (LPA) were found to be crucial for growth of the cancer cells. CT could inhibit TNF-α-induced expression and secretion of ATX that led to decreased activity of lysophospholipase D, thus decreasing the conversion of LPC to LPA. CT inhibits hepatocellular carcinoma cell growth in vitro via regulating the ATX-LPA pathway.

  4. Kaempferol suppresses bladder cancer tumor growth by inhibiting cell proliferation and inducing apoptosis.

    Science.gov (United States)

    Dang, Qiang; Song, Wenbin; Xu, Defeng; Ma, Yanmin; Li, Feng; Zeng, Jin; Zhu, Guodong; Wang, Xinyang; Chang, Luke S; He, Dalin; Li, Lei

    2015-09-01

    The effects of the flavonoid compound, kaempferol, which is an inhibitor of cancer cell proliferation and an inducer of cell apoptosis have been shown in various cancers, including lung, pancreatic, and ovarian, but its effect has never been studied in bladder cancer. Here, we investigated the effects of kaempferol on bladder cancer using multiple in vitro cell lines and in vivo mice studies. The MTT assay results on various bladder cancer cell lines showed that kaempferol enhanced bladder cancer cell cytotoxicity. In contrast, when analyzed by the flow cytometric analysis, DNA ladder experiment, and TUNEL assay, kaempferol significantly was shown to induce apoptosis and cell cycle arrest. These in vitro results were confirmed in in vivo mice studies using subcutaneous xenografted mouse models. Consistent with the in vitro results, we found that treating mice with kaempferol significant suppression in tumor growth compared to the control group mice. Tumor tissue staining results showed decreased expressions of the growth related markers, yet increased expressions in apoptosis markers in the kaempferol treated group mice tissues compared to the control group mice. In addition, our in vitro and in vivo data showed kaempferol can also inhibit bladder cancer invasion and metastasis. Further mechanism dissection studies showed that significant down-regulation of the c-Met/p38 signaling pathway is responsible for the kaempferol mediated cell proliferation inhibition. All these findings suggest kaempferol might be an effective and novel chemotherapeutic drug to apply for the future therapeutic agent to combat bladder cancer. © 2014 Wiley Periodicals, Inc.

  5. Toosendanin induces apoptosis through suppression of JNK signaling pathway in HL-60 cells.

    Science.gov (United States)

    Ju, Jianming; Qi, Zhichao; Cai, Xueting; Cao, Peng; Liu, Nan; Wang, Shuzhen; Chen, Yijun

    2013-02-01

    Toosendanin (TSN), a triterpenoid isolated from Melia toosendan Sieb. et Zucc., has been found to suppress proliferation and induce apoptosis in a variety of human cancer cells. However, the mechanism how TSN induces apoptosis remains poorly understood. In this study, we examined the effects of TSN on the growth, cell cycle arrest, induction of apoptosis and the involved signaling pathway in human promyelocytic leukemia HL-60 cells. Proli