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Sample records for activation induced cytidine

  1. Biological function of activation-induced cytidine deaminase (AID

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    Ritu Kumar

    2014-10-01

    Full Text Available Activation-induced Cytidine Deaminase (AID is an essential regulator of B cell diversification, but its full range of action has until recently been an enigma. Based on homology, it was originally proposed to be an RNA-editing enzyme, but so far, no RNA substrates are known. Rather, it functions by deaminating cytidine, and in this manner, coupled with base-excision repair or mismatch repair machinery, it is a natural mutator. This allows it to play a central role in adaptive immunity, whereby it initiates the processes of class switch recombination and somatic hypermutation to help generate a diverse and high-affinity repertoire of immunoglobulin isotypes. More recently, it has been appreciated that methylated cytidine, already known as a key epigenetic mark on DNA controlling gene expression, can also be a target for AID modification. Coupled with repair machinery, this can facilitate the active removal of methylated DNA. This activity can impact the process of cellular reprogramming, including transition of a somatic cell to pluripotency, which requires major reshuffling of epigenetic memory. Thus, seemingly disparate roles for AID in controlling immune diversity and epigenetic memory have a common mechanistic basis. However, the very activity that is so useful for B cell diversity and cellular reprogramming is dangerous for the integrity of the genome. Thus, AID expression and activity is tightly regulated, and deregulation is associated with diseases including cancer. Here, we review the range of AID functions with a focus on its mechanisms of action and regulation. Major questions remain to be answered concerning how and when AID is targeted to specific loci and how this impacts development and disease.

  2. Activation-induced cytidine deaminase induces reproducible DNA breaks at many non-Ig Loci in activated B cells

    NARCIS (Netherlands)

    Staszewski, Ori; Baker, Richard E.; Ucher, Anna J.; Martier, Raygene; Stavnezer, Janet; Guikema, Jeroen E. J.

    2011-01-01

    After immunization or infection, activation-induced cytidine deaminase (AID) initiates diversification of immunoglobulin (Ig) genes in B cells, introducing mutations within the antigen-binding V regions (somatic hypermutation, SHM) and double-strand DNA breaks (DSBs) into switch (S) regions, leading

  3. Involvement of activation-induced cytidine deaminase in skin cancer development.

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    Nonaka, Taichiro; Toda, Yoshinobu; Hiai, Hiroshi; Uemura, Munehiro; Nakamura, Motonobu; Yamamoto, Norio; Asato, Ryo; Hattori, Yukari; Bessho, Kazuhisa; Minato, Nagahiro; Kinoshita, Kazuo

    2016-04-01

    Most skin cancers develop as the result of UV light-induced DNA damage; however, a substantial number of cases appear to occur independently of UV damage. A causal link between UV-independent skin cancers and chronic inflammation has been suspected, although the precise mechanism underlying this association is unclear. Here, we have proposed that activation-induced cytidine deaminase (AID, encoded by AICDA) links chronic inflammation and skin cancer. We demonstrated that Tg mice expressing AID in the skin spontaneously developed skin squamous cell carcinoma with Hras and Trp53 mutations. Furthermore, genetic deletion of Aicda reduced tumor incidence in a murine model of chemical-induced skin carcinogenesis. AID was expressed in human primary keratinocytes in an inflammatory stimulus-dependent manner and was detectable in human skin cancers. Together, the results of this study indicate that inflammation-induced AID expression promotes skin cancer development independently of UV damage and suggest AID as a potential target for skin cancer therapeutics.

  4. Acquisition of Genetic Aberrations by Activation-Induced Cytidine Deaminase (AID) during Inflammation-Associated Carcinogenesis

    International Nuclear Information System (INIS)

    Takai, Atsushi; Marusawa, Hiroyuki; Chiba, Tsutomu

    2011-01-01

    Genetic abnormalities such as nucleotide alterations and chromosomal disorders that accumulate in various tumor-related genes have an important role in cancer development. The precise mechanism of the acquisition of genetic aberrations, however, remains unclear. Activation-induced cytidine deaminase (AID), a nucleotide editing enzyme, is essential for the diversification of antibody production. AID is expressed only in activated B lymphocytes under physiologic conditions and induces somatic hypermutation and class switch recombination in immunoglobulin genes. Inflammation leads to aberrant AID expression in various gastrointestinal organs and increased AID expression contributes to cancer development by inducing genetic alterations in epithelial cells. Studies of how AID induces genetic disorders are expected to elucidate the mechanism of inflammation-associated carcinogenesis

  5. Expression of activation-induced cytidine deaminase is confined to B-cell non-Hodgkin's lymphomas of germinal-center phenotype

    NARCIS (Netherlands)

    Smit, Laura A.; Bende, Richard J.; Aten, Jan; Guikema, Jeroen E. J.; Aarts, Wilhelmina M.; van Noesel, Carel J. M.

    2003-01-01

    Activation-induced cytidine deaminase (AID) is essential for somatic hypermutation and class switch recombination of the immunoglobulin (IG) genes in B cells. It has recently been proposed that AID, as the newly identified DNA mutator in man, may be instrumental in initiation and progression of

  6. Activation-induced cytidine deaminase deficiency causes organ-specific autoimmune disease.

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    Koji Hase

    Full Text Available Activation-induced cytidine deaminase (AID expressed by germinal center B cells is a central regulator of somatic hypermutation (SHM and class switch recombination (CSR. Humans with AID mutations develop not only the autosomal recessive form of hyper-IgM syndrome (HIGM2 associated with B cell hyperplasia, but also autoimmune disorders by unknown mechanisms. We report here that AID-/- mice spontaneously develop tertiary lymphoid organs (TLOs in non-lymphoid tissues including the stomach at around 6 months of age. At a later stage, AID-/- mice develop a severe gastritis characterized by loss of gastric glands and epithelial hyperplasia. The disease development was not attenuated even under germ-free (GF conditions. Gastric autoantigen -specific serum IgM was elevated in AID-/- mice, and the serum levels correlated with the gastritis pathological score. Adoptive transfer experiments suggest that autoimmune CD4+ T cells mediate gastritis development as terminal effector cells. These results suggest that abnormal B-cell expansion due to AID deficiency can drive B-cell autoimmunity, and in turn promote TLO formation, which ultimately leads to the propagation of organ-specific autoimmune effector CD4+ T cells. Thus, AID plays an important role in the containment of autoimmune diseases by negative regulation of autoreactive B cells.

  7. A Novel Regulator of Activation-Induced Cytidine Deaminase/APOBECs in Immunity and Cancer: Schrödinger’s CATalytic Pocket

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    Mani Larijani

    2017-04-01

    Full Text Available Activation-induced cytidine deaminase (AID and its relative APOBEC3 cytidine deaminases boost immune response by mutating immune or viral genes. Because of their genome-mutating activities, AID/APOBECs are also drivers of tumorigenesis. Due to highly charged surfaces, extensive non-specific protein–protein/nucleic acid interactions, formation of polydisperse oligomers, and general insolubility, structure elucidation of these proteins by X-ray crystallography and NMR has been challenging. Hence, almost all available AID/APOBEC structures are of mutated and/or truncated versions. In 2015, we reported a functional structure for AID using a combined computational–biochemical approach. In so doing, we described a new regulatory mechanism that is a first for human DNA/RNA-editing enzymes. This mechanism involves dynamic closure of the catalytic pocket. Subsequent X-ray and NMR studies confirmed our discovery by showing that other APOBEC3s also close their catalytic pockets. Here, we highlight catalytic pocket closure as an emerging and important regulatory mechanism of AID/APOBEC3s. We focus on three sub-topics: first, we propose that variable pocket closure rates across AID/APOBEC3s underlie differential activity in immunity and cancer and review supporting evidence. Second, we discuss dynamic pocket closure as an ever-present internal regulator, in contrast to other proposed regulatory mechanisms that involve extrinsic binding partners. Third, we compare the merits of classical approaches of X-ray and NMR, with that of emerging computational–biochemical approaches, for structural elucidation specifically for AID/APOBEC3s.

  8. Epstein-Barr Virus Lytic Reactivation Activates B Cells Polyclonally and Induces Activation-Induced Cytidine Deaminase Expression: A Mechanism Underlying Autoimmunity and Its Contribution to Graves' Disease.

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    Nagata, Keiko; Kumata, Keisuke; Nakayama, Yuji; Satoh, Yukio; Sugihara, Hirotsugu; Hara, Sayuri; Matsushita, Michiko; Kuwamoto, Satoshi; Kato, Masako; Murakami, Ichiro; Hayashi, Kazuhiko

    2017-04-01

    Graves' disease is an autoimmune disease that results in and is the most common cause of hyperthyroidism, and the reactivation of persisting Epstein-Barr virus (EBV) in B lymphocytes induces the differentiation of host B cells into plasma cells. We previously reported that some EBV-infected B cells had thyrotropin receptor antibodies (TRAbs) as surface immunoglobulins (Igs), and EBV reactivation induced these TRAb+EBV+ cells to produce TRAbs. EBV reactivation induces Ig production from host B cells. The purpose of the present study was to examine total Ig productions from B cell culture fluids and to detect activation-induced cytidine deaminase (AID), nuclear factor kappa B (NF-κB), and EBV latent membrane protein (LMP) 1 in culture B cells during EBV reactivation induction and then we discussed the mechanisms of EBV reactivation-induced Ig production in relation to autoimmunity. We showed that the EBV reactivation induces the production of every isotype of Ig and suggested that the Ig production was catalyzed by AID through LMP1 and NF-κB. The results that the amount of IgM was significantly larger compared with IgG suggested the polyclonal B cell activation due to LMP1. We proposed the pathway of EBV reactivation induced Ig production; B cells newly infected with EBV are activated by polyclonal B cell activation and produce Igs through plasma cell differentiation induced by EBV reactivation. LMP1-induced AID enabled B cells to undergo class-switch recombination to produce every isotype of Ig. According to this mechanism, EBV rescues autoreactive B cells to produce autoantibodies, which contribute to the development and exacerbation of autoimmune diseases.

  9. Activation-induced cytidine deaminase (AID) is localized to subnuclear domains enriched in splicing factors

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    Hu, Yi, E-mail: yihooyi@gmail.com; Ericsson, Ida, E-mail: ida.ericsson@ntnu.no; Doseth, Berit, E-mail: berit.doseth@ntnu.no; Liabakk, Nina B., E-mail: nina.beate.liabakk@ntnu.no; Krokan, Hans E., E-mail: hans.krokan@ntnu.no; Kavli, Bodil, E-mail: bodil.kavli@ntnu.no

    2014-03-10

    Activation-induced cytidine deaminase (AID) is the mutator enzyme in adaptive immunity. AID initiates the antibody diversification processes in activated B cells by deaminating cytosine to uracil in immunoglobulin genes. To some extent other genes are also targeted, which may lead to genome instability and B cell malignancy. Thus, it is crucial to understand its targeting and regulation mechanisms. AID is regulated at several levels including subcellular compartmentalization. However, the complex nuclear distribution and trafficking of AID has not been studied in detail previously. In this work, we examined the subnuclear localization of AID and its interaction partner CTNNBL1 and found that they associate with spliceosome-associated structures including Cajal bodies and nuclear speckles. Moreover, protein kinase A (PKA), which activates AID by phosphorylation at Ser38, is present together with AID in nuclear speckles. Importantly, we demonstrate that AID physically associates with the major spliceosome subunits (small nuclear ribonucleoproteins, snRNPs), as well as other essential splicing components, in addition to the transcription machinery. Based on our findings and the literature, we suggest a transcription-coupled splicing-associated model for AID targeting and activation. - Highlights: • AID and its interaction partner CTNNBL1 localize to Cajal bodies and nuclear speckles. • AID associates with its activating kinase PKA in nuclear speckles. • AID is linked to the splicing machinery in switching B-cells. • Our findings suggest a transcription-coupled splicing associated mechanism for AID targeting and activation.

  10. Autosomal recessive hyper IgM syndrome associated with activation-induced cytidine deaminase gene in three Turkish siblings presented with tuberculosis lymphadenitis - Case report.

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    Patiroglu, Turkan; Akar, H Haluk; van der Burg, Mirjam; Unal, Ekrem

    2015-09-01

    The hyper-immunoglobulin M (HIGM) syndrome is a heterogeneous group of genetic disorders characterized by recurrent infections, decreased serum levels of immunoglobulin G (IgG) and IgA, and normal/increased serum levels of IgM. Herein, we describe three Turkish siblings with HIGM syndrome who had a homozygous missense mutation (c.70C>T, p.Arg24Trp) in the activation-induced cytidine deaminase gene which results in autosomal recessive HIGM syndrome. Two of the siblings, sibling 1 and sibling 3, presented with cervical deep abscess and cervical tuberculosis lymphadenitis, respectively.

  11. SU-C-303-01: Activation-Induced Cytidine Deaminase Confers Cancer Resistance to Radiation Therapy

    International Nuclear Information System (INIS)

    Yi, S; La Count, S; Liu, J; Bai, X; Lu, L

    2015-01-01

    Purpose: To study the role of activation-induced cytidine deaminase (AID) in malignant cell resistance to radiation therapy. Methods: We first developed several small devices that could be used to adopt radiation beams from clinical high dose rate brachy therapy (HDR) or linac-based megavoltage machines to perform pre-clinical cell and mouse experiments. Then we used these devices to deliver radiation to AID-positive and AID-silenced cancer cells or tumors formed by these cells in mice. Cells and mice bearing tumors received the same dose under the same experimental conditions. For cells, we observed the apoptosis and the cell survival rate over time. For mice bearing tumors, we measured and recorded the tumor sizes every other day for 4 weeks. Results: For cell experiments, we found that the AID-positive cells underwent much less apoptosis compared with AID-silenced cells upon radiation. And for mouse experiments, we found that AID-positive tumors grew significantly faster than the AID-silenced tumors despite of receiving the same doses of radiation. Conclusion: Our study suggests that AID may confer cancer resistance to radiation therapy, and AID may be a significant biomarker predicting cancer resistance to radiation therapy for certain cancer types

  12. Cytidine triphosphate synthase activity and mRNA expression in normal human blood cells

    NARCIS (Netherlands)

    Verschuur, A. C.; van Gennip, A. H.; Muller, E. J.; Voûte, P. A.; Vreken, P.; van Kuilenburg, A. B.

    1999-01-01

    Cytidine triphosphate (CTP) synthase is one of the key enzymes in pyrimidine nucleotide anabolic pathways. The activity of this enzyme is elevated in various malignancies including acute lymphocytic leukemia (ALL). In this study we investigated the activity of CTP synthase in various human blood

  13. Expression of activation-induced cytidine deaminase gene in B lymphocytes of patients with common variable immunodeficiency.

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    Abolhassani, Hassan; Farrokhi, Amir Salek; Pourhamdi, Shabnam; Mohammadinejad, Payam; Sadeghi, Bamdad; Moazzeni, Seyed-Mohammad; Aghamohammadi, Asghar

    2013-08-01

    Common variable immunodeficiency (CVID) is a heterogeneous disorder characterized by reduced serum level of IgG, IgA or IgM and recurrent bacterial infections. Class switch recombination (CSR) as a critical process in immunoglobulin production is defective in a group of CVID patients. Activation-induced cytidine deaminase (AID) protein is an important molecule involving CSR process. The aim of this study was to investigate the AID gene mRNA production in a group of CVID patients indicating possible role of this molecule in this disorder. Peripheral blood mononuclear cells (PBMC) of 29 CVID patients and 21 healthy controls were isolated and stimulated by CD40L and IL-4 to induce AID gene expression. After 5 days AID gene mRNA production was investigated by real time polymerase chain reaction. AID gene was expressed in all of the studied patients. However the mean density of extracted AID mRNA showed higher level in CVID patients (230.95±103.04 ng/ml) rather than controls (210.00±44.72 ng/ml; P=0.5). CVID cases with lower level of AID had decreased total level of IgE (P=0.04) and stimulated IgE production (P=0.02); while cases with increased level of AID presented higher level of IgA (P=0.04) and numbers of B cells (P=0.02) and autoimmune disease (P=0.02). Different levels of AID gene expression may have important roles in dysregulation of immune system and final clinical presentation in CVID patients. Therefore investigating the expression of AID gene can help in classifying CVID patients.

  14. Hypermutation by intersegmental transfer of APOBEC3G cytidine deaminase.

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    Nowarski, Roni; Britan-Rosich, Elena; Shiloach, Tamar; Kotler, Moshe

    2008-10-01

    Deamination of cytidine residues in single-stranded DNA (ssDNA) is an important mechanism by which apolipoprotein B mRNA-editing, catalytic polypeptide-like (APOBEC) enzymes restrict endogenous and exogenous viruses. The dynamic process underlying APOBEC-induced hypermutation is not fully understood. Here we show that enzymatically active APOBEC3G can be detected in wild-type Vif(+) HIV-1 virions, albeit at low levels. In vitro studies showed that single enzyme-DNA encounters result in distributive deamination of adjacent cytidines. Nonlinear translocation of APOBEC3G, however, directed scattered deamination of numerous targets along the DNA. Increased ssDNA concentrations abolished enzyme processivity in the case of short, but not long, DNA substrates, emphasizing the key role of rapid intersegmental transfer in targeting the deaminase. Our data support a model by which APOBEC3G intersegmental transfer via monomeric binding to two ssDNA segments results in dispersed hypermutation of viral genomes.

  15. APOBEC3G enhances lymphoma cell radioresistance by promoting cytidine deaminase-dependent DNA repair.

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    Nowarski, Roni; Wilner, Ofer I; Cheshin, Ori; Shahar, Or D; Kenig, Edan; Baraz, Leah; Britan-Rosich, Elena; Nagler, Arnon; Harris, Reuben S; Goldberg, Michal; Willner, Itamar; Kotler, Moshe

    2012-07-12

    APOBEC3 proteins catalyze deamination of cytidines in single-stranded DNA (ssDNA), providing innate protection against retroviral replication by inducing deleterious dC > dU hypermutation of replication intermediates. APOBEC3G expression is induced in mitogen-activated lymphocytes; however, no physiologic role related to lymphoid cell proliferation has yet to be determined. Moreover, whether APOBEC3G cytidine deaminase activity transcends to processing cellular genomic DNA is unknown. Here we show that lymphoma cells expressing high APOBEC3G levels display efficient repair of genomic DNA double-strand breaks (DSBs) induced by ionizing radiation and enhanced survival of irradiated cells. APOBEC3G transiently accumulated in the nucleus in response to ionizing radiation and was recruited to DSB repair foci. Consistent with a direct role in DSB repair, inhibition of APOBEC3G expression or deaminase activity resulted in deficient DSB repair, whereas reconstitution of APOBEC3G expression in leukemia cells enhanced DSB repair. APOBEC3G activity involved processing of DNA flanking a DSB in an integrated reporter cassette. Atomic force microscopy indicated that APOBEC3G multimers associate with ssDNA termini, triggering multimer disassembly to multiple catalytic units. These results identify APOBEC3G as a prosurvival factor in lymphoma cells, marking APOBEC3G as a potential target for sensitizing lymphoma to radiation therapy.

  16. Activation-induced cytidine deaminase (AID)-dependent somatic hypermutation requires a splice isoform of the serine/arginine-rich (SR) protein SRSF1.

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    Kanehiro, Yuichi; Todo, Kagefumi; Negishi, Misaki; Fukuoka, Junji; Gan, Wenjian; Hikasa, Takuya; Kaga, Yoshiaki; Takemoto, Masayuki; Magari, Masaki; Li, Xialu; Manley, James L; Ohmori, Hitoshi; Kanayama, Naoki

    2012-01-24

    Somatic hypermutation (SHM) of Ig variable region (IgV) genes requires both IgV transcription and the enzyme activation-induced cytidine deaminase (AID). Identification of a cofactor responsible for the fact that IgV genes are much more sensitive to AID-induced mutagenesis than other genes is a key question in immunology. Here, we describe an essential role for a splice isoform of the prototypical serine/arginine-rich (SR) protein SRSF1, termed SRSF1-3, in AID-induced SHM in a DT40 chicken B-cell line. Unexpectedly, we found that SHM does not occur in a DT40 line lacking SRSF1-3 (DT40-ASF), although it is readily detectable in parental DT40 cells. Strikingly, overexpression of AID in DT40-ASF cells led to a large increase in nonspecific (off-target) mutations. In contrast, introduction of SRSF1-3, but not SRSF1, into these cells specifically restored SHM without increasing off-target mutations. Furthermore, we found that SRSF1-3 binds preferentially to the IgV gene and inhibits processing of the Ig transcript, providing a mechanism by which SRSF1-3 makes the IgV gene available for AID-dependent SHM. SRSF1 not only acts as an essential splicing factor but also regulates diverse aspects of mRNA metabolism and maintains genome stability. Our findings, thus, define an unexpected and important role for SRSF1, particularly for its splice variant, in enabling AID to function specifically on its natural substrate during SHM.

  17. In vitro optimization of non-small cell lung cancer activity with troxacitabine, L-1,3-dioxolane-cytidine, prodrugs

    NARCIS (Netherlands)

    Radi, Marco; Adema, Auke D.; Daft, Jonathan R.; Cho, Jong H.; Hoebe, Eveline K.; Alexander, Lou-Ella M. M.; Peters, Godefridus J.; Chu, Chung K.

    2007-01-01

    l-1,3-Dioxolane-cytidine, a potent anticancer agent against leukemia, has limited efficacy against solid tumors, perhaps due to its hydrophilicity. Herein, a library of prodrugs were synthesized to optimize in vitro antitumor activity against non-small cell lung cancer. N4-Substituted fatty acid

  18. Pyrimidine Pool Disequilibrium Induced by a Cytidine Deaminase Deficiency Inhibits PARP-1 Activity, Leading to the Under Replication of DNA.

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    Simon Gemble

    2015-07-01

    Full Text Available Genome stability is jeopardized by imbalances of the dNTP pool; such imbalances affect the rate of fork progression. For example, cytidine deaminase (CDA deficiency leads to an excess of dCTP, slowing the replication fork. We describe here a novel mechanism by which pyrimidine pool disequilibrium compromises the completion of replication and chromosome segregation: the intracellular accumulation of dCTP inhibits PARP-1 activity. CDA deficiency results in incomplete DNA replication when cells enter mitosis, leading to the formation of ultrafine anaphase bridges between sister-chromatids at "difficult-to-replicate" sites such as centromeres and fragile sites. Using molecular combing, electron microscopy and a sensitive assay involving cell imaging to quantify steady-state PAR levels, we found that DNA replication was unsuccessful due to the partial inhibition of basal PARP-1 activity, rather than slower fork speed. The stimulation of PARP-1 activity in CDA-deficient cells restores replication and, thus, chromosome segregation. Moreover, increasing intracellular dCTP levels generates under-replication-induced sister-chromatid bridges as efficiently as PARP-1 knockdown. These results have direct implications for Bloom syndrome (BS, a rare genetic disease combining susceptibility to cancer and genomic instability. BS results from mutation of the BLM gene, encoding BLM, a RecQ 3'-5' DNA helicase, a deficiency of which leads to CDA downregulation. BS cells thus have a CDA defect, resulting in a high frequency of ultrafine anaphase bridges due entirely to dCTP-dependent PARP-1 inhibition and independent of BLM status. Our study describes previously unknown pathological consequences of the distortion of dNTP pools and reveals an unexpected role for PARP-1 in preventing DNA under-replication and chromosome segregation defects.

  19. APOBEC3 cytidine deaminases in double-strand DNA break repair and cancer promotion.

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    Nowarski, Roni; Kotler, Moshe

    2013-06-15

    High frequency of cytidine to thymidine conversions was identified in the genome of several types of cancer cells. In breast cancer cells, these mutations are clustered in long DNA regions associated with single-strand DNA (ssDNA), double-strand DNA breaks (DSB), and genomic rearrangements. The observed mutational pattern resembles the deamination signature of cytidine to uridine carried out by members of the APOBEC3 family of cellular deaminases. Consistently, APOBEC3B (A3B) was recently identified as the mutational source in breast cancer cells. A3G is another member of the cytidine deaminases family predominantly expressed in lymphoma cells, where it is involved in mutational DSB repair following ionizing radiation treatments. This activity provides us with a new paradigm for cancer cell survival and tumor promotion and a mechanistic link between ssDNA, DSBs, and clustered mutations. Cancer Res; 73(12); 3494-8. ©2013 AACR. ©2013 AACR.

  20. Influence of x-rays on the deamination of cytidine compounds in yeasts

    International Nuclear Information System (INIS)

    Marutyan, S.V.; Navasardyan, A.L.; Arakelyan, L.R.; Navasardyan, L.A.

    2011-01-01

    The investigation of deamination of cytidine, cytosine, and cytidine nucleotides (CMP, CDP and CTP) was carried out on yeast Candida guilliermondii. It has been shown, that after exposure to X-ray the value of deamination of (CTD) was decreased, and the value of deamination of cytosine was increased. The increase of deamination level was detected in presence of all substrates besides cytidine after the post radiation repair of cells

  1. Enhanced Bacterial α(2,6-Sialyltransferase Reaction through an Inhibition of Its Inherent Sialidase Activity by Dephosphorylation of Cytidine-5'-Monophosphate.

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    Ji-Yeon Kang

    Full Text Available Bacterial α(2,6-sialyltransferases (STs from Photobacterium damsela, Photobacterium sp. JT-ISH-224, and P. leiognathi JT-SHIZ-145 were recombinantly expressed in Escherichia coli and their ST activities were compared directly using a galactosylated bi-antennary N-glycan as an acceptor substrate. In all ST reactions, there was an increase of sialylated glycans at shorter reaction times and later a decrease in prolonged reactions, which is related with the inherent sialidase activities of bacterial STs. These sialidase activities are greatly increased by free cytidine monophosphate (CMP generated from a donor substrate CMP-N-acetylneuraminic acid (CMP-Neu5Ac during the ST reactions. The decrease of sialylated glycans in prolonged ST reaction was prevented through an inhibition of sialidase activity by simple treatment of alkaline phosphatase (AP, which dephosphorylates CMP to cytidine. Through supplemental additions of AP and CMP-Neu5Ac to the reaction using the recombinant α(2,6-ST from P. leiognathi JT-SHIZ-145 (P145-ST, the content of bi-sialylated N-glycan increased up to ~98% without any decrease in prolonged reactions. This optimized P145-ST reaction was applied successfully for α(2,6-sialylation of asialofetuin, and this resulted in a large increase in the populations of multi-sialylated N-glycans compared with the reaction without addition of AP and CMP-Neu5Ac. These results suggest that the optimized reaction using the recombinant P145-ST readily expressed from E. coli has a promise for economic glycan synthesis and glyco-conjugate remodeling.

  2. Significance of determination of serum cytidine deaminase (CD) levels for diagnosis of active rheumatoid arthritis (RA)

    International Nuclear Information System (INIS)

    Xiao Chuangqing; Jang Xiaogong; He Yunnan

    2005-01-01

    Objective: To determine the clinical value of measurement of serum cytidine deaminase (CD) levels in patients with active rheumatoid arthritis (RA). Methods: Serum levels of CD were detected with spectrophotometry, in 33 patients with active RA and 60 controls. The erythrocyte sedimentation rate (ESR) and CRP content were also determined in both groups. Results: The ser- um CD contents in patients with active RA(14.80 ± 2.11U/ml) were significantly higher than those in controls(4.86±1.86 U/ml,P<0.01). The CRP contents (51.46 ± 20.43mg/L) and ESR readings(85.03 ± 27.6mm/h) in the patients were also significantly higher than those in the controls(3.40 ± 2.21mg/L and 13.04 ± 4.89mm/h respectively, all P<0.01). In the patients, the serum CD contents were linearly positively correlated with the ESR contents and CRP readings (r=0.6324 and 0.8013 respectively, P <0.01). Conclusion: Serum CD is an early biochemical marker for diagnosis of active rheumatoid arthritis and is also of prognostic value. (authors)

  3. Photoelectron and computational studies of the copper-nucleoside anionic complexes, Cu-(cytidine) and Cu-(uridine)

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    Li, Xiang; Ko, Yeon-Jae; Wang, Haopeng; Bowen, Kit H.; Guevara-García, Alfredo; Martínez, Ana

    2011-02-01

    The copper-nucleoside anions, Cu-(cytidine) and Cu-(uridine), have been generated in the gas phase and studied by both experimental (anion photoelectron spectroscopy) and theoretical (density functional calculations) methods. The photoelectron spectra of both systems are dominated by single, intense, and relatively narrow peaks. These peaks are centered at 2.63 and 2.71 eV for Cu-(cytidine) and Cu-(uridine), respectively. According to our calculations, Cu-(cytidine) and Cu-(uridine) species with these peak center [vertical detachment energy (VDE)] values correspond to structures in which copper atomic anions are bound to the sugar portions of their corresponding nucleosides largely through electrostatic interactions; the observed species are anion-molecule complexes. The combination of experiment and theory also reveal the presence of a slightly higher energy, anion-molecule complex isomer in the case of the Cu-(cytidine). Furthermore, our calculations found that chemically bond isomers of these species are much more stable than their anion-molecule complex counterparts, but since their calculated VDE values are larger than the photon energy used in these experiments, they were not observed.

  4. Photoelectron and computational studies of the copper-nucleoside anionic complexes, Cu(-)(cytidine) and Cu(-)(uridine).

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    Li, Xiang; Ko, Yeon-Jae; Wang, Haopeng; Bowen, Kit H; Guevara-García, Alfredo; Martínez, Ana

    2011-02-07

    The copper-nucleoside anions, Cu(-)(cytidine) and Cu(-)(uridine), have been generated in the gas phase and studied by both experimental (anion photoelectron spectroscopy) and theoretical (density functional calculations) methods. The photoelectron spectra of both systems are dominated by single, intense, and relatively narrow peaks. These peaks are centered at 2.63 and 2.71 eV for Cu(-)(cytidine) and Cu(-)(uridine), respectively. According to our calculations, Cu(-)(cytidine) and Cu(-)(uridine) species with these peak center [vertical detachment energy (VDE)] values correspond to structures in which copper atomic anions are bound to the sugar portions of their corresponding nucleosides largely through electrostatic interactions; the observed species are anion-molecule complexes. The combination of experiment and theory also reveal the presence of a slightly higher energy, anion-molecule complex isomer in the case of the Cu(-)(cytidine). Furthermore, our calculations found that chemically bond isomers of these species are much more stable than their anion-molecule complex counterparts, but since their calculated VDE values are larger than the photon energy used in these experiments, they were not observed.

  5. Intestinal absorption of cytidine diphosphate choline and its changes in the digestive tract

    International Nuclear Information System (INIS)

    Yashima, Keisuke; Takamatsu, Masatoshi; Okuda, Kunio

    1975-01-01

    Intestinal absorption of cytidine diphosphate choline (CDP-choline), its structural changes in the digestive tract, and hepatic uptake have been investigated in rats using 14 C-labeled ( 14 CH 3 attached to N of choline) and 3 H-labeled (at C 5 of pyrimidine) compounds. The results indicate that: 1) CDP-choline is relatively stable in the stomach, but is quickly degraded into cytidine and choline in the intestine; 2) The hepatic uptakes of 14 C and 3 H reach the maximum in two to three hours after oral administration; 3) Whereas the amount of 14 C remaining in the gut is inversely related to the hepatic uptake, no similar correlation is seen with 3 H-labeled CDP-choline, and 4) Extrahepatic uptake of 14 C and 3 H is very small. The possibility of phosphorylation in the mucosa of choline and cytidine has been discussed, based on the differences in relative amount of radioactivity in individual broken-down products in the intestinal lumen and mucosa. (auth.)

  6. Asymmetric Modification of Hepatitis B Virus (HBV) Genomes by an Endogenous Cytidine Deaminase inside HBV Cores Informs a Model of Reverse Transcription.

    Science.gov (United States)

    Nair, Smita; Zlotnick, Adam

    2018-05-15

    Cytidine deaminases inhibit replication of a broad range of DNA viruses by deaminating cytidines on single-stranded DNA (ssDNA) to generate uracil. While several lines of evidence have revealed hepatitis B virus (HBV) genome editing by deamination, it is still unclear which nucleic acid intermediate of HBV is modified. Hepatitis B virus has a relaxed circular double-stranded DNA (rcDNA) genome that is reverse transcribed within virus cores from a RNA template. The HBV genome also persists as covalently closed circular DNA (cccDNA) in the nucleus of an infected cell. In the present study, we found that in HBV-producing HepAD38 and HepG2.2.15 cell lines, endogenous cytidine deaminases edited 10 to 25% of HBV rcDNA genomes, asymmetrically with almost all mutations on the 5' half of the minus strand. This region corresponds to the last half of the minus strand to be protected by plus-strand synthesis. Within this half of the genome, the number of mutations peaks in the middle. Overexpressed APOBEC3A and APOBEC3G could be packaged in HBV capsids but did not change the amount or distribution of mutations. We found no deamination on pregenomic RNA (pgRNA), indicating that an intact genome is encapsidated and deaminated during or after reverse transcription. The deamination pattern suggests a model of rcDNA synthesis in which pgRNA and then newly synthesized minus-sense single-stranded DNA are protected from deaminase by interaction with the virus capsid; during plus-strand synthesis, when enough dsDNA has been synthesized to displace the remaining minus strand from the capsid surface, the single-stranded DNA becomes deaminase sensitive. IMPORTANCE Host-induced mutation of the HBV genome by APOBEC proteins may be a path to clearing the virus. We examined cytidine-to-thymidine mutations in the genomes of HBV particles grown in the presence or absence of overexpressed APOBEC proteins. We found that genomes were subjected to deamination activity during reverse transcription

  7. Of the Nine Cytidine Deaminase-Like Genes in Arabidopsis, Eight Are Pseudogenes and Only One Is Required to Maintain Pyrimidine Homeostasis in Vivo.

    Science.gov (United States)

    Chen, Mingjia; Herde, Marco; Witte, Claus-Peter

    2016-06-01

    CYTIDINE DEAMINASE (CDA) catalyzes the deamination of cytidine to uridine and ammonia in the catabolic route of C nucleotides. The Arabidopsis (Arabidopsis thaliana) CDA gene family comprises nine members, one of which (AtCDA) was shown previously in vitro to encode an active CDA. A possible role in C-to-U RNA editing or in antiviral defense has been discussed for other members. A comprehensive bioinformatic analysis of plant CDA sequences, combined with biochemical functionality tests, strongly suggests that all Arabidopsis CDA family members except AtCDA are pseudogenes and that most plants only require a single CDA gene. Soybean (Glycine max) possesses three CDA genes, but only two encode functional enzymes and just one has very high catalytic efficiency. AtCDA and soybean CDAs are located in the cytosol. The functionality of AtCDA in vivo was demonstrated with loss-of-function mutants accumulating high amounts of cytidine but also CMP, cytosine, and some uridine in seeds. Cytidine hydrolysis in cda mutants is likely caused by NUCLEOSIDE HYDROLASE1 (NSH1) because cytosine accumulation is strongly reduced in a cda nsh1 double mutant. Altered responses of the cda mutants to fluorocytidine and fluorouridine indicate that a dual specific nucleoside kinase is involved in cytidine as well as uridine salvage. CDA mutants display a reduction in rosette size and have fewer leaves compared with the wild type, which is probably not caused by defective pyrimidine catabolism but by the accumulation of pyrimidine catabolism intermediates reaching toxic concentrations. © 2016 American Society of Plant Biologists. All Rights Reserved.

  8. Preparation of alpha-5-aza-2'-deoxy-[6-3H]cytidine

    Czech Academy of Sciences Publication Activity Database

    Elbert, Tomáš; Černý, B.

    2008-01-01

    Roč. 73, č. 5 (2008), s. 701-704 ISSN 0010-0765 Institutional research plan: CEZ:AV0Z40550506 Keywords : alfa-5aza-2'-deoxy-cytidine Subject RIV: CC - Organic Chemistry Impact factor: 0.784, year: 2008

  9. Regulated production and anti-HIV type 1 activities of cytidine deaminases APOBEC3B, 3F, and 3G.

    Science.gov (United States)

    Rose, Kristine M; Marin, Mariana; Kozak, Susan L; Kabat, David

    2005-07-01

    APOBEC3G and 3F (A3G and A3F) cytidine deaminases incorporate into retroviral cores where they lethally hypermutate nascent DNA reverse transcripts. As substantiated here, the viral infectivity factor (Vif) encoded by human immunodeficiency virus type-1 (HIV-1) binds A3G and A3F and induces their degradation, thereby precluding their incorporation into viral progeny. Previous evidence suggested that A3G is expressed in H9 and other nonpermissive cells that contain this antiviral defense but not in several permissive cells, and that overexpression of A3G or A3F makes permissive cells nonpermissive. Using a broader panel of cell lines, we confirmed a correlation between A3G and cellular abilities to inactivate HIV-1(Deltavif). However, there was a quantitative discrepancy because several cells with weak antiviral activities had similar amounts of wild-type A3G mRNA and protein compared to H9 cells. Antiviral activity of H9 cells was also attenuated in some conditions. These quantitative discrepancies could not be explained by the presence of A3F or other A3G paralogs in some of the cell lines. Thus, A3A, A3B, and A3C had weak but significant anti-HIV-1 activities and did not dominantly interfere with A3G or A3F antiviral functions. Control of A3G synthesis by the protein kinase C/mitogen-activated protein kinase kinase/extracellular signal-regulated kinase pathway was also similar in permissive and nonpermissive cells. A3G in highly permissive cells is degraded by Vif, suggesting that it is not in a sequestered site, and is specifically incorporated in low amounts into HIV-1(Deltavif). Although A3G and/or A3F inactivate HIV-1(Deltavif) and are neutralized by Vif, the antiviral properties of cell lines are also influenced by other cellular and viral factors.

  10. Enzymatic conformational fluctuations along the reaction coordinate of cytidine deaminase

    OpenAIRE

    Noonan, Ryan C.; Carter, Charles W.; Bagdassarian, Carey K.

    2002-01-01

    Analysis of the crystal structures for cytidine deaminase complexed with substrate analog 3-deazacytidine, transition-state analog zebularine 3,4-hydrate, and product uridine establishes significant changes in the magnitude of atomic-scale fluctuations along the (approximate) reaction coordinate of this enzyme. Differences in fluctuations between the substrate analog complex, transition-state analog complex, and product complex are monitored via changes in corresponding crystallographic tempe...

  11. A terbium(III)-organic framework for highly selective sensing of cytidine triphosphate.

    Science.gov (United States)

    Zhao, Xi Juan; He, Rong Xing; Li, Yuan Fang

    2012-11-21

    Highly selective sensing of cytidine triphosphate (CTP) against other triphosphate nucleosides including ATP, GTP and UTP is successfully achieved with a luminescent terbium(III)-organic framework (TbOF) of [Tb(2)(2,3-pzdc)(2)(ox)(H(2)O)(2)](n) (2,3-pzdc(2-) = 2,3-pyrazinedicarboxylate, ox(2-) = oxalate).

  12. A Trojan-Horse Peptide-Carboxymethyl-Cytidine Antibiotic from Bacillus amyloliquefaciens.

    Science.gov (United States)

    Serebryakova, Marina; Tsibulskaya, Darya; Mokina, Olga; Kulikovsky, Alexey; Nautiyal, Manesh; Van Aerschot, Arthur; Severinov, Konstantin; Dubiley, Svetlana

    2016-12-07

    Microcin C and related antibiotics are Trojan-horse peptide-adenylates. The peptide part is responsible for facilitated transport inside the sensitive cell, where it gets processed to release a toxic warhead-a nonhydrolyzable aspartyl-adenylate, which inhibits aspartyl-tRNA synthetase. Adenylation of peptide precursors is carried out by MccB THIF-type NAD/FAD adenylyltransferases. Here, we describe a novel microcin C-like compound from Bacillus amyloliquefaciens. The B. amyloliquefaciens MccB demonstrates an unprecedented ability to attach a terminal cytidine monophosphate to cognate precursor peptide in cellular and cell free systems. The cytosine moiety undergoes an additional modification-carboxymethylation-that is carried out by the C-terminal domain of MccB and the MccS enzyme that produces carboxy-SAM, which serves as a donor of the carboxymethyl group. We show that microcin C-like compounds carrying terminal cytosines are biologically active and target aspartyl-tRNA synthetase, and that the carboxymethyl group prevents resistance that can occur due to modification of the warhead. The results expand the repertoire of known enzymatic modifications of peptides that can be used to obtain new biological activities while avoiding or limiting bacterial resistance.

  13. Cytidine deaminases from B. subtilis and E. coli: compensating effects of changing zinc coordination and quaternary structure.

    Science.gov (United States)

    Carlow, D C; Carter, C W; Mejlhede, N; Neuhard, J; Wolfenden, R

    1999-09-21

    Cytidine deaminase from E. coli is a dimer of identical subunits (M(r) = 31 540), each containing a single zinc atom. Cytidine deaminase from B. subtilis is a tetramer of identical subunits (M(r) = 14 800). After purification from an overexpressing strain, the enzyme from B. subtilis is found to contain a single atom of zinc per enzyme subunit by flame atomic absorption spectroscopy. Fluorescence titration indicates that each of the four subunits contains a binding site for the transition state analogue inhibitor 5-fluoro-3,4-dihydrouridine. A region of amino acid sequence homology, containing residues that are involved in zinc coordination in the enzyme from E. coli, strongly suggests that in the enzyme from B. subtilis, zinc is coordinated by the thiolate side chains of three cysteine residues (Cys-53, Cys-86, and Cys-89) [Song, B. H., and Neuhard, J. (1989) Mol. Gen. Genet. 216, 462-468]. This pattern of zinc coordination appears to be novel for a hydrolytic enzyme, and might be expected to reduce the reactivity of the active site substantially compared with that of the enzyme from E. coli (His-102, Cys-129, and Cys-132). Instead, the B. subtilis and E. coli enzymes are found to be similar in their activities, and also in their relative binding affinities for a series of structurally related inhibitors with binding affinities that span a range of 6 orders of magnitude. In addition, the apparent pK(a) value of the active site is shifted upward by less than 1 unit. Sequence alignments, together with model building, suggest one possible mechanism of compensation.

  14. The association constant of 5',8-cyclo-2'-deoxyguanosine with cytidine

    Directory of Open Access Journals (Sweden)

    Amedeo eCapobianco

    2015-03-01

    Full Text Available The association of 5',8-cyclo-2'-deoxyguanosine (cdG, a DNA tandem lesion, with its complementary base cytosine has been studied by voltammetry and NMR in chloroform, using properly silylated derivatives of the two nucleobases for increasing their solubilities. Both voltammetric data and NMR titrations indicated that the Watson-Crick complex of cytidine with cdG is weaker than that with guanosine, the difference being approximately of one order of magnitude between the two association constants.

  15. A putative antiviral role of plant cytidine deaminases [version 2; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Susana Martín

    2017-06-01

    Full Text Available Background: A mechanism of innate antiviral immunity operating against viruses infecting mammalian cells has been described during the last decade.  Host cytidine deaminases (e.g., APOBEC3 proteins edit viral genomes, giving rise to hypermutated nonfunctional viruses; consequently, viral fitness is reduced through lethal mutagenesis.  By contrast, sub-lethal hypermutagenesis may contribute to virus evolvability by increasing population diversity.  To prevent genome editing, some viruses have evolved proteins that mediate APOBEC3 degradation.  The model plant Arabidopsis thaliana genome encodes nine cytidine deaminases (AtCDAs, raising the question of whether deamination is an antiviral mechanism in plants as well. Methods: Here we tested the effects of expression of AtCDAs on the pararetrovirus Cauliflower mosaic virus (CaMV. Two different experiments were carried out. First, we transiently overexpressed each one of the nine A. thaliana AtCDA genes in Nicotiana bigelovii plants infected with CaMV, and characterized the resulting mutational spectra, comparing them with those generated under normal conditions.  Secondly, we created A. thaliana transgenic plants expressing an artificial microRNA designed to knock-out the expression of up to six AtCDA genes.  This and control plants were then infected with CaMV.  Virus accumulation and mutational spectra where characterized in both types of plants. Results:  We have shown that the A. thaliana AtCDA1 gene product exerts a mutagenic activity, significantly increasing the number of G to A mutations in vivo, with a concomitant reduction in the amount of CaMV genomes accumulated.  Furthermore, the magnitude of this mutagenic effect on CaMV accumulation is positively correlated with the level of AtCDA1 mRNA expression in the plant. Conclusions: Our results suggest that deamination of viral genomes may also work as an antiviral mechanism in plants.

  16. ESR study of irradiated single crystals of the cocrystalline complex of cytidine: Salicylic acid

    International Nuclear Information System (INIS)

    Close, D.M.; Sagstuen, E.

    1983-01-01

    Irradiation at 77 K of single crystals of the 1:1 complex of cytidine and salicylic acid produces a phenoxyl radical formed by oxidation of the salicylic acid. Anisotropic hyperfine coupling tensors have been determined for this radical which are associated with the para and ortho hydrogens. No cytidine oxidation products (alkoxy or hydroxyalkyl radicals) were observed at 77 K. Following the decay of the phenoxyl radical at room temperature, four radicals were detected. These include the cytosine 5--yl and 6--yl radicals, formed by H addition to the cytosine ring, and an anisotropic doublet. By UV irradiation at room temperature, it is possible to convert a significant fraction of 6-yl radicals into 5-yl radicals. Hyperfine coupling and g tensors determined for the anisotropic doublet indicate that this radical is formed in the C/sub 1'/-C/sub 2'/ region of the sugar moiety. These results indicate a shift in radiation damage away from the salicylic acid upon warming, and show that the radiation chemistry of the cocrystalline complex is different from that of the isolated bases

  17. The AID-induced DNA damage response in chromatin

    DEFF Research Database (Denmark)

    Daniel, Jeremy A; Nussenzweig, André

    2013-01-01

    Chemical modifications to the DNA and histone protein components of chromatin can modulate gene expression and genome stability. Understanding the physiological impact of changes in chromatin structure remains an important question in biology. As one example, in order to generate antibody diversity...... with somatic hypermutation and class switch recombination, chromatin must be made accessible for activation-induced cytidine deaminase (AID)-mediated deamination of cytosines in DNA. These lesions are recognized and removed by various DNA repair pathways but, if not handled properly, can lead to formation...... of oncogenic chromosomal translocations. In this review, we focus the discussion on how chromatin-modifying activities and -binding proteins contribute to the native chromatin environment in which AID-induced DNA damage is targeted and repaired. Outstanding questions remain regarding the direct roles...

  18. APOBEC3B-Mediated Cytidine Deamination Is Required for Estrogen Receptor Action in Breast Cancer

    Directory of Open Access Journals (Sweden)

    Manikandan Periyasamy

    2015-10-01

    Full Text Available Estrogen receptor α (ERα is the key transcriptional driver in a large proportion of breast cancers. We report that APOBEC3B (A3B is required for regulation of gene expression by ER and acts by causing C-to-U deamination at ER binding regions. We show that these C-to-U changes lead to the generation of DNA strand breaks through activation of base excision repair (BER and to repair by non-homologous end-joining (NHEJ pathways. We provide evidence that transient cytidine deamination by A3B aids chromatin modification and remodelling at the regulatory regions of ER target genes that promotes their expression. A3B expression is associated with poor patient survival in ER+ breast cancer, reinforcing the physiological significance of A3B for ER action.

  19. N3 and O2 Protonated Tautomeric Conformations of 2 '-Deoxycytidine and Cytidine Coexist in the Gas Phase

    NARCIS (Netherlands)

    Wu, R.R.; Yang, B.; Frieler, C.E.; Berden, G.; Oomens, J.; Rodgers, M.T.

    2015-01-01

    Infrared multiple photon dissociation action spectra of the protonated forms of the cytidyl nucleosides, 2'-deoxycytidine, [dCyd+H](+), and cytidine, [Cyd+H](+), are acquired over the IR fingerprint and hydrogen-stretching regions. Electronic structure calculations are performed at the

  20. Inducible tertiary lymphoid structures, autoimmunity, and exocrine dysfunction in a novel model of salivary gland inflammation in C57BL/6 mice.

    Science.gov (United States)

    Bombardieri, Michele; Barone, Francesca; Lucchesi, Davide; Nayar, Saba; van den Berg, Wim B; Proctor, Gordon; Buckley, Christopher D; Pitzalis, Costantino

    2012-10-01

    Salivary glands in patients with Sjögren's syndrome (SS) develop ectopic lymphoid structures (ELS) characterized by B/T cell compartmentalization, the formation of high endothelial venules, follicular dendritic cell networks, functional B cell activation with expression of activation-induced cytidine deaminase, as well as local differentiation of autoreactive plasma cells. The mechanisms that trigger ELS formation, autoimmunity, and exocrine dysfunction in SS are largely unknown. In this article, we present a novel model of inducible ectopic lymphoid tissue formation, breach of humoral self-tolerance, and salivary hypofunction after delivery of a replication-deficient adenovirus-5 in submandibular glands of C57BL/6 mice through retrograde excretory duct cannulation. In this model, inflammation rapidly and consistently evolves from diffuse infiltration toward the development of SS-like periductal lymphoid aggregates within 2 wk from AdV delivery. These infiltrates progressively acquire ELS features and support functional GL7(+)/activation-induced cytidine deaminase(+) germinal centers. Formation of ELS is preceded by ectopic expression of lymphoid chemokines CXCL13, CCL19, and lymphotoxin-β, and is associated with development of anti-nuclear Abs in up to 75% of mice. Finally, reduction in salivary flow was observed over 3 wk post-AdV infection, consistent with exocrine gland dysfunction as a consequence of the inflammatory response. This novel model has the potential to unravel the cellular and molecular mechanisms that regulate ELS formation and their role in exocrine dysfunction and autoimmunity in SS.

  1. Reduction of nucleotides by ionizing radiation: uridine 5' phosphate, and cytidine 3' phosphate

    International Nuclear Information System (INIS)

    Box, H.C.; Potter, W.R.; Budzinski, E.E.

    1974-01-01

    Anions formed by the addition of an electron to the uracil base were observed in single crystals of the barium salt of uridine 5' phosphate x irradiated at 4.2 0 K. The hyperfine coupling tensor for the C 6 -H proton was deduced from ENDOR measurements; the principal values are -59.12, -32.92 and -16.24 MHz. Similar measurements were made on single crystals of cytidine 3' phosphate. The principal values for the C 6 -H proton hyperfine coupling in the anion formed on the cytosine base are -59.26, -33.98 and -14.68 MHz. (U.S.)

  2. The reduction of nucleotides by ionizing radiation: uridine 5' phosphate and cytidine 3' phosphate

    International Nuclear Information System (INIS)

    Box, H.C.; Potter, W.R.; Budzinski, E.E.

    1975-01-01

    Anions formed by the addition of an electron to the uracil base were observed in single crystals of the barium salt of uridine 5' phosphate x-irradiated at 4.2 degreeK. The hyperfine coupling tensor for the C 6 --H proton was deduced from ENDOR measurements; the principal values are -59.12, -32.92, and -16.24 MHz. Similar measurements were made on single crystals of cytidine 3' phosphate. The principal values for the C 6 --H proton hyperfine coupling in the anion formed on the cytosine base are -59.26, -33.98, and -14.68 MHz

  3. AID-induced decrease in topoisomerase 1 induces DNA structural alteration and DNA cleavage for class switch recombination.

    Science.gov (United States)

    Kobayashi, Maki; Aida, Masatoshi; Nagaoka, Hitoshi; Begum, Nasim A; Kitawaki, Yoko; Nakata, Mikiyo; Stanlie, Andre; Doi, Tomomitsu; Kato, Lucia; Okazaki, Il-mi; Shinkura, Reiko; Muramatsu, Masamichi; Kinoshita, Kazuo; Honjo, Tasuku

    2009-12-29

    To initiate class switch recombination (CSR) activation-induced cytidine deaminase (AID) induces staggered nick cleavage in the S region, which lies 5' to each Ig constant region gene and is rich in palindromic sequences. Topoisomerase 1 (Top1) controls the supercoiling of DNA by nicking, rotating, and religating one strand of DNA. Curiously, Top1 reduction or AID overexpression causes the genomic instability. Here, we report that the inactivation of Top1 by its specific inhibitor camptothecin drastically blocked both the S region cleavage and CSR, indicating that Top1 is responsible for the S region cleavage in CSR. Surprisingly, AID expression suppressed Top1 mRNA translation and reduced its protein level. In addition, the decrease in the Top1 protein by RNA-mediated knockdown augmented the AID-dependent S region cleavage, as well as CSR. Furthermore, Top1 reduction altered DNA structure of the Smu region. Taken together, AID-induced Top1 reduction alters S region DNA structure probably to non-B form, on which Top1 can introduce nicks but cannot religate, resulting in S region cleavage.

  4. Re-editing the paradigm of Cytidine (C) to Uridine (U) RNA editing.

    Science.gov (United States)

    Fossat, Nicolas; Tam, Patrick P L

    2014-01-01

    Cytidine (C) to Uridine (U) RNA editing is a post-trancriptional modification that until recently was known to only affect Apolipoprotein b (Apob) RNA and minimally require 2 components of the C to U editosome, the deaminase APOBEC1 and the RNA-binding protein A1CF. Our latest work has identified a novel RNA-binding protein, RBM47, as a core component of the editosome, which can substitute A1CF for the editing of ApoB mRNA. In addition, new RNA species that are subjected to C to U editing have been identified. Here, we highlight these recent discoveries and discuss how they change our view of the composition of the C to U editing machinery and expand our knowledge of the functional attributes of C to U RNA editing.

  5. Nbs1 ChIP-Seq Identifies Off-Target DNA Double-Strand Breaks Induced by AID in Activated Splenic B Cells.

    Directory of Open Access Journals (Sweden)

    Lyne Khair

    2015-08-01

    Full Text Available Activation-induced cytidine deaminase (AID is required for initiation of Ig class switch recombination (CSR and somatic hypermutation (SHM of antibody genes during immune responses. AID has also been shown to induce chromosomal translocations, mutations, and DNA double-strand breaks (DSBs involving non-Ig genes in activated B cells. To determine what makes a DNA site a target for AID-induced DSBs, we identify off-target DSBs induced by AID by performing chromatin immunoprecipitation (ChIP for Nbs1, a protein that binds DSBs, followed by deep sequencing (ChIP-Seq. We detect and characterize hundreds of off-target AID-dependent DSBs. Two types of tandem repeats are highly enriched within the Nbs1-binding sites: long CA repeats, which can form Z-DNA, and tandem pentamers containing the AID target hotspot WGCW. These tandem repeats are not nearly as enriched at AID-independent DSBs, which we also identified. Msh2, a component of the mismatch repair pathway and important for genome stability, increases off-target DSBs, similar to its effect on Ig switch region DSBs, which are required intermediates during CSR. Most of the off-target DSBs are two-ended, consistent with generation during G1 phase, similar to DSBs in Ig switch regions. However, a minority are one-ended, presumably due to conversion of single-strand breaks to DSBs during replication. One-ended DSBs are repaired by processes involving homologous recombination, including break-induced replication repair, which can lead to genome instability. Off-target DSBs, especially those present during S phase, can lead to chromosomal translocations, deletions and gene amplifications, resulting in the high frequency of B cell lymphomas derived from cells that express or have expressed AID.

  6. Crystal structure of APOBEC3A bound to single-stranded DNA reveals structural basis for cytidine deamination and specificity.

    Science.gov (United States)

    Kouno, Takahide; Silvas, Tania V; Hilbert, Brendan J; Shandilya, Shivender M D; Bohn, Markus F; Kelch, Brian A; Royer, William E; Somasundaran, Mohan; Kurt Yilmaz, Nese; Matsuo, Hiroshi; Schiffer, Celia A

    2017-04-28

    Nucleic acid editing enzymes are essential components of the immune system that lethally mutate viral pathogens and somatically mutate immunoglobulins, and contribute to the diversification and lethality of cancers. Among these enzymes are the seven human APOBEC3 deoxycytidine deaminases, each with unique target sequence specificity and subcellular localization. While the enzymology and biological consequences have been extensively studied, the mechanism by which APOBEC3s recognize and edit DNA remains elusive. Here we present the crystal structure of a complex of a cytidine deaminase with ssDNA bound in the active site at 2.2 Å. This structure not only visualizes the active site poised for catalysis of APOBEC3A, but pinpoints the residues that confer specificity towards CC/TC motifs. The APOBEC3A-ssDNA complex defines the 5'-3' directionality and subtle conformational changes that clench the ssDNA within the binding groove, revealing the architecture and mechanism of ssDNA recognition that is likely conserved among all polynucleotide deaminases, thereby opening the door for the design of mechanistic-based therapeutics.

  7. Optimization of catalyst-solvent system for preparation of alpha-5,6-dihydro-5-aza-2'-deoxy-[6-3H]-cytidine

    Czech Academy of Sciences Publication Activity Database

    Elbert, Tomáš

    2011-01-01

    Roč. 54, č. 5 (2011), s. 285-285 ISSN 0362-4803. [Workshop of the International Isotope Society - Central European Division. The Synthesis and Applications of Isotopes and Isotopically Labelled Compounds /17./. 23.09.2010-24.09.2010, Bad Soden] Institutional research plan: CEZ:AV0Z40550506 Keywords : tritium * labelled compounds * alfa-5,6-dihydro-5-aza-2'-deoxy-cytidine Subject RIV: CC - Organic Chemistry

  8. Myeloprotection by Cytidine Deaminase Gene Transfer in Antileukemic Therapy

    Directory of Open Access Journals (Sweden)

    Nico Lachmann

    2013-03-01

    Full Text Available Gene transfer of drug resistance (CTX-R genes can be used to protect the hematopoietic system from the toxicity of anticancer chemotherapy and this concept recently has been proven by overexpression of a mutant O6-methylguaninemethyltransferase in the hematopoietic system of glioblastoma patients treated with temozolomide. Given its protection capacity against such relevant drugs as cytosine arabinoside (ara-C, gemcitabine, decitabine, or azacytidine and the highly hematopoiesis-specific toxicity profile of several of these agents, cytidine deaminase (CDD represents another interesting candidate CTX-R gene and our group recently has established the myeloprotective capacity of CDD gene transfer in a number of murine transplant studies. Clinically, CDD overexpression appears particularly suited to optimize treatment strategies for acute leukemias and myelodysplasias given the efficacy of ara-C (and to a lesser degree decitabine and azacytidine in these disease entities. This article will review the current state of the art with regard to CDD gene transfer and point out potential scenarios for a clinical application of this strategy. In addition, risks and potential side effects associated with this approach as well as strategies to overcome these problems will be highlighted.

  9. Ag(I)-mediated homo and hetero pairs of guanosine and cytidine: monitoring by circular dichroism spectroscopy.

    Science.gov (United States)

    Goncharova, Iryna

    2014-01-24

    Ag(I)-containing compounds are attractive as antibacterial and antifungal agents. The renewed interest in the application of silver(I) compounds has led to the need for detailed knowledge of the mechanism of their action. One of the possible ways is the coordination of Ag(I) to G-C pairs of DNA, where Ag(+) ions form Ag(I)-mediated base pairs and inhibit the transcription. Herein, a systematic chiroptical study on silver(I)-mediated homo and mixed pairs of the C-G complementary-base derivatives cytidine(C) and 5'-guanosine monophosphate(G) in water is presented. Ag(I)-mediated homo and hetero pairs of G and C and their self-assembled species were studied under two pH levels (7.0 and 10.0) by vibrational (VCD) and electronic circular dichroism(ECD). VCD was used for the first time in this field and showed itself to be a powerful method for obtaining specific structural information in solution. Based on results of the VCD experiments, the different geometries of the homo pairs were proposed under pH 7.0 and 10.0. ECD was used as a diagnostic tool to characterize the studied systems and as a contact point between the previously defined structures of the metal or proton mediated pairs of nucleobases and the systems studied here. On the basis of the obtained data, the formation of the self-assembled species of cytidine with a structure similar to the i-motif structure in DNA was proposed at pH 10.0. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Antigen receptors and somatic hypermutation in B-cell chronic lymphocytic leukemia with Richter's transformation

    NARCIS (Netherlands)

    Smit, Laura A.; van Maldegem, Febe; Langerak, Anton W.; van der Schoot, C. Ellen; de Wit, Mireille J.; Bea, Silvia; Campo, Elias; Bende, Richard J.; van Noesel, Carel J. M.

    2006-01-01

    BACKGROUND AND OBJECTIVES: Activation-induced cytidine deaminase is essential for somatic hypermutation and class switch recombination of the immunoglobulin genes in B cells. It has been proposed that aberrant targeting of the somatic hypermutation machinery is instrumental in initiation and

  11. Hypochlorite-induced damage to nucleosides

    DEFF Research Database (Denmark)

    Hawkins, C L; Davies, Michael Jonathan

    2001-01-01

    HOCl damage to DNA bases. We show that reaction of HOCl with the exocyclic -NH(2) groups of cytidine, adenosine, and guanosine, and the ring NH groups of all bases, yields chloramines (RNHCl/RR'NCl). These are the major initial products. Chloramine decay can be accelerated by UV light and metal ions...... for radical formation is cytidine > adenosine = guanosine > uridine = thymidine. These data are inconsistent with the selectivity of HOCl attack and the stability of the resulting chloramines, but can be rationalized if chlorine transfer between bases is rapid and yields the most stable chloramine...

  12. Development of a simple and efficient method for assaying cytidine monophosphate sialic acid synthetase activity using an enzymatic reduced nicotinamide adenine dinucleotide/oxidized nicotinamide adenine dinucleotide converting system.

    Science.gov (United States)

    Fujita, Akiko; Sato, Chihiro; Münster-Kühnel, Anja-K; Gerardy-Schahn, Rita; Kitajima, Ken

    2005-02-01

    A new reliable method to assay the activity of cytidine monophosphate sialic acid (CMP-Sia) synthetase (CSS) has been developed. The activation of sialic acids (Sia) to CMP-Sia is a prerequisite for the de novo synthesis of sialoglycoconjugates. In vertebrates, CSS has been cloned from human, mouse, and rainbow trout, and the crystal structure has been resolved for the mouse enzyme. The mouse and rainbow trout enzyme have been compared with respect to substrate specificity, demonstrating that the mouse enzyme exhibits a pronounced specificity for N-acetylneuraminic acid (Neu5Ac), while the rainbow trout CSS is equally active with either of three Sia species, Neu5Ac, N-glycolylneuraminic acid (Neu5Gc), and deaminoneuraminic acid (KDN). However, molecular details that explain the pronounced substrate specificities are unknown. Understanding the catalytic mechanisms of these enzymes is of major importance, since CSSs play crucial roles in cellular sialylation patterns and thus are potential drug targets in a number of pathophysiological situations. The availability of the cDNAs and the obtained structural data enable rational approaches; however, these efforts are limited by the lack of a reliable high-throughput assay system. Here we describe a new assay system that allows product quantification in a reduced nicotinamide adenine dinucleotide (NADH)-dependent color reaction. The activation reaction catalyzed by CSS, CTP+Sia-->CMP-Sia+pyrophosphate, was evaluated by a consumption of Sia, which corresponds to that of NADH on the following two successive reactions: (i) Sia-->pyruvate+ManNAc (or Man), catalyzed by a sialic acid lyase (SAL), and (ii) pyruvate+NADH-->lactate+oxidized nicotinamide adenine dinucleotide (NAD+), catalyzed by a lactate dehydrogenase (LDH). Consumption of NADH can be photometrically monitored on a microtiter plate reader for a number of test samples at the same time. Furthermore, based on the quantification of CSS used in the SAL/LDH assay

  13. Restriction of Equine Infectious Anemia Virus by Equine APOBEC3 Cytidine Deaminases ▿ †

    Science.gov (United States)

    Zielonka, Jörg; Bravo, Ignacio G.; Marino, Daniela; Conrad, Elea; Perković, Mario; Battenberg, Marion; Cichutek, Klaus; Münk, Carsten

    2009-01-01

    The mammalian APOBEC3 (A3) proteins comprise a multigene family of cytidine deaminases that act as potent inhibitors of retroviruses and retrotransposons. The A3 locus on the chromosome 28 of the horse genome contains multiple A3 genes: two copies of A3Z1, five copies of A3Z2, and a single copy of A3Z3, indicating a complex evolution of multiple gene duplications. We have cloned and analyzed for expression the different equine A3 genes and examined as well the subcellular distribution of the corresponding proteins. Additionally, we have tested the functional antiretroviral activity of the equine and of several of the human and nonprimate A3 proteins against the Equine infectious anemia virus (EIAV), the Simian immunodeficiency virus (SIV), and the Adeno-associated virus type 2 (AAV-2). Hematopoietic cells of horses express at least five different A3s: A3Z1b, A3Z2a-Z2b, A3Z2c-Z2d, A3Z2e, and A3Z3, whereas circulating macrophages, the natural target of EIAV, express only part of the A3 repertoire. The five A3Z2 tandem copies arose after three consecutive, recent duplication events in the horse lineage, after the split between Equidae and Carnivora. The duplicated genes show different antiviral activities against different viruses: equine A3Z3 and A3Z2c-Z2d are potent inhibitors of EIAV while equine A3Z1b, A3Z2a-Z2b, A3Z2e showed only weak anti-EIAV activity. Equine A3Z1b and A3Z3 restricted AAV and all equine A3s, except A3Z1b, inhibited SIV. We hypothesize that the horse A3 genes are undergoing a process of subfunctionalization in their respective viral specificities, which might provide the evolutionary advantage for keeping five copies of the original gene. PMID:19458006

  14. Selective induction of DNA repair pathways in human B cells activated by CD4+ T cells.

    Directory of Open Access Journals (Sweden)

    Xiaosheng Wu

    Full Text Available Greater than 75% of all hematologic malignancies derive from germinal center (GC or post-GC B cells, suggesting that the GC reaction predisposes B cells to tumorigenesis. Because GC B cells acquire expression of the highly mutagenic enzyme activation-induced cytidine deaminase (AID, GC B cells may require additional DNA repair capacity. The goal of this study was to investigate whether normal human B cells acquire enhanced expression of DNA repair factors upon AID induction. We first demonstrated that several DNA mismatch repair, homologous recombination, base excision repair, and ATR signaling genes were overexpressed in GC B cells relative to naïve and memory B cells, reflecting activation of a process we have termed somatic hyperrepair (SHR. Using an in vitro system, we next characterized activation signals required to induce AID expression and SHR. Although AID expression was induced by a variety of polyclonal activators, SHR induction strictly required signals provided by contact with activated CD4+ T cells, and B cells activated in this manner displayed reduced levels of DNA damage-induced apoptosis. We further show the induction of SHR is independent of AID expression, as GC B cells from AID-/-mice retained heightened expression of SHR proteins. In consideration of the critical role that CD4+ T cells play in inducing the SHR process, our data suggest a novel role for CD4+ T cells in the tumor suppression of GC/post-GC B cells.

  15. DNA-dependent protein kinase inhibits AID-induced antibody gene conversion.

    Directory of Open Access Journals (Sweden)

    Adam J L Cook

    2007-04-01

    Full Text Available Affinity maturation and class switching of antibodies requires activation-induced cytidine deaminase (AID-dependent hypermutation of Ig V(DJ rearrangements and Ig S regions, respectively, in activated B cells. AID deaminates deoxycytidine bases in Ig genes, converting them into deoxyuridines. In V(DJ regions, subsequent excision of the deaminated bases by uracil-DNA glycosylase, or by mismatch repair, leads to further point mutation or gene conversion, depending on the species. In Ig S regions, nicking at the abasic sites produced by AID and uracil-DNA glycosylases results in staggered double-strand breaks, whose repair by nonhomologous end joining mediates Ig class switching. We have tested whether nonhomologous end joining also plays a role in V(DJ hypermutation using chicken DT40 cells deficient for Ku70 or the DNA-dependent protein kinase catalytic subunit (DNA-PKcs. Inactivation of the Ku70 or DNA-PKcs genes in DT40 cells elevated the rate of AID-induced gene conversion as much as 5-fold. Furthermore, DNA-PKcs-deficiency appeared to reduce point mutation. The data provide strong evidence that double-strand DNA ends capable of recruiting the DNA-dependent protein kinase complex are important intermediates in Ig V gene conversion.

  16. DNA/RNA hybrid substrates modulate the catalytic activity of purified AID.

    Science.gov (United States)

    Abdouni, Hala S; King, Justin J; Ghorbani, Atefeh; Fifield, Heather; Berghuis, Lesley; Larijani, Mani

    2018-01-01

    Activation-induced cytidine deaminase (AID) converts cytidine to uridine at Immunoglobulin (Ig) loci, initiating somatic hypermutation and class switching of antibodies. In vitro, AID acts on single stranded DNA (ssDNA), but neither double-stranded DNA (dsDNA) oligonucleotides nor RNA, and it is believed that transcription is the in vivo generator of ssDNA targeted by AID. It is also known that the Ig loci, particularly the switch (S) regions targeted by AID are rich in transcription-generated DNA/RNA hybrids. Here, we examined the binding and catalytic behavior of purified AID on DNA/RNA hybrid substrates bearing either random sequences or GC-rich sequences simulating Ig S regions. If substrates were made up of a random sequence, AID preferred substrates composed entirely of DNA over DNA/RNA hybrids. In contrast, if substrates were composed of S region sequences, AID preferred to mutate DNA/RNA hybrids over substrates composed entirely of DNA. Accordingly, AID exhibited a significantly higher affinity for binding DNA/RNA hybrid substrates composed specifically of S region sequences, than any other substrates composed of DNA. Thus, in the absence of any other cellular processes or factors, AID itself favors binding and mutating DNA/RNA hybrids composed of S region sequences. AID:DNA/RNA complex formation and supporting mutational analyses suggest that recognition of DNA/RNA hybrids is an inherent structural property of AID. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Combined deficiency of MSH2 and Sμ region abolishes class switch recombination.

    Science.gov (United States)

    Leduc, Claire; Haddad, Dania; Laviolette-Malirat, Nathalie; Nguyen Huu, Ngoc-Sa; Khamlichi, Ahmed Amine

    2010-10-01

    Class switch recombination (CSR) is mediated by G-rich tandem repeated sequences termed switch regions. Transcription of switch regions generates single-stranded R loops that provide substrates for activation-induced cytidine deaminase. Mice deficient in MSH2 have a mild defect in CSR and analysis of their switch junctions has led to a model in which MSH2 is more critical for switch recombination events outside than within the tandem repeats. It is also known that deletion of the whole Sμ region severely impairs but does not abrogate CSR despite the lack of detectable R loops. Here, we demonstrate that deficiency of both MSH2 and the Sμ region completely abolishes CSR and that the abrogation occurs at the genomic level. This finding further supports the crucial role of MSH2 outside the tandem repeats. It also indicates that during CSR, MSH2 has access to activation-induced cytidine deaminase targets in R-loop-deficient Iμ-Cμ sequences rarely used in CSR, suggesting an MSH2-dependent DNA processing activity at the Iμ exon that may decrease with transcription elongation across the Sμ region.

  18. Lurbinectedin induces depletion of tumor-associated macrophages, an essential component of its in vivo synergism with gemcitabine, in pancreatic adenocarcinoma mouse models

    Science.gov (United States)

    Céspedes, María Virtudes; Guillén, María José; López-Casas, Pedro Pablo; Sarno, Francesca; Gallardo, Alberto; Álamo, Patricia; Cuevas, Carmen; Hidalgo, Manuel; Galmarini, Carlos María; Allavena, Paola; Avilés, Pablo; Mangues, Ramón

    2016-01-01

    ABSTRACT We explored whether the combination of lurbinectedin (PM01183) with the antimetabolite gemcitabine could result in a synergistic antitumor effect in pancreatic ductal adenocarcinoma (PDA) mouse models. We also studied the contribution of lurbinectedin to this synergism. This drug presents a dual pharmacological effect that contributes to its in vivo antitumor activity: (i) specific binding to DNA minor grooves, inhibiting active transcription and DNA repair; and (ii) specific depletion of tumor-associated macrophages (TAMs). We evaluated the in vivo antitumor activity of lurbinectedin and gemcitabine as single agents and in combination in SW-1990 and MIA PaCa-2 cell-line xenografts and in patient-derived PDA models (AVATAR). Lurbinectedin-gemcitabine combination induced a synergistic effect on both MIA PaCa-2 [combination index (CI)=0.66] and SW-1990 (CI=0.80) tumor xenografts. It also induced complete tumor remissions in four out of six patient-derived PDA xenografts. This synergism was associated with enhanced DNA damage (anti-γ-H2AX), cell cycle blockage, caspase-3 activation and apoptosis. In addition to the enhanced DNA damage, which is a consequence of the interaction of the two drugs with the DNA, lurbinectedin induced TAM depletion leading to cytidine deaminase (CDA) downregulation in PDA tumors. This effect could, in turn, induce an increase of gemcitabine-mediated DNA damage that was especially relevant in high-density TAM tumors. These results show that lurbinectedin can be used to develop ‘molecularly targeted’ combination strategies. PMID:27780828

  19. Lurbinectedin induces depletion of tumor-associated macrophages, an essential component of its in vivo synergism with gemcitabine, in pancreatic adenocarcinoma mouse models

    Directory of Open Access Journals (Sweden)

    María Virtudes Céspedes

    2016-12-01

    Full Text Available We explored whether the combination of lurbinectedin (PM01183 with the antimetabolite gemcitabine could result in a synergistic antitumor effect in pancreatic ductal adenocarcinoma (PDA mouse models. We also studied the contribution of lurbinectedin to this synergism. This drug presents a dual pharmacological effect that contributes to its in vivo antitumor activity: (i specific binding to DNA minor grooves, inhibiting active transcription and DNA repair; and (ii specific depletion of tumor-associated macrophages (TAMs. We evaluated the in vivo antitumor activity of lurbinectedin and gemcitabine as single agents and in combination in SW-1990 and MIA PaCa-2 cell-line xenografts and in patient-derived PDA models (AVATAR. Lurbinectedin-gemcitabine combination induced a synergistic effect on both MIA PaCa-2 [combination index (CI=0.66] and SW-1990 (CI=0.80 tumor xenografts. It also induced complete tumor remissions in four out of six patient-derived PDA xenografts. This synergism was associated with enhanced DNA damage (anti-γ-H2AX, cell cycle blockage, caspase-3 activation and apoptosis. In addition to the enhanced DNA damage, which is a consequence of the interaction of the two drugs with the DNA, lurbinectedin induced TAM depletion leading to cytidine deaminase (CDA downregulation in PDA tumors. This effect could, in turn, induce an increase of gemcitabine-mediated DNA damage that was especially relevant in high-density TAM tumors. These results show that lurbinectedin can be used to develop ‘molecularly targeted’ combination strategies.

  20. Structural and kinetic studies of the allosteric transition in Sulfolobus solfataricus uracil phosphoribosyltransferase: Permanent activation by engineering of the C-terminus

    DEFF Research Database (Denmark)

    Christoffersen, Stig; Kadziola, Anders; Johansson, Eva

    2009-01-01

    and PPi, in the other sites. Combined with three existing structures of uracil phosphoribosyltransferase in complex with UMP and the allosteric inhibitor cytidine triphosphate (CTP), these structures provide valuable insight into the mechanism of allosteric transition from inhibited to active enzyme...

  1. The enzymatic activity of CEM15/Apobec-3G is essential for the regulation of the infectivity of HIV-1 virion but not a sole determinant of its antiviral activity.

    Science.gov (United States)

    Shindo, Keisuke; Takaori-Kondo, Akifumi; Kobayashi, Masayuki; Abudu, Aierken; Fukunaga, Keiko; Uchiyama, Takashi

    2003-11-07

    Human immunodeficiency virus, type 1 (HIV-1) Vif protein plays an essential role in the regulation of the infectivity of HIV-1 virion. Vif functions to counteract an anti-HIV-1 cellular factor in non-permissive cells, CEM15/Apobec-3G, which shares a cytidine deaminase motif. CEM15/Apobec-3G deaminates dC to dU in the minus strand DNA of HIV-1, resulting in G to A hypermutation in the plus strand DNA. In this study, we have done the mutagenesis analysis on two cytidine deaminase motifs in CEM15/Apobec-3G and examined their antiviral functions as well as the DNA editing activity. Point mutations in the C-terminal active site such as E259Q and C291A almost completely abrogated the antiviral function, while those in the N-terminal active site such as E67Q and C100A retained this activity to a lesser extent as compared with that of the wild type. The DNA editing activities of E67Q and E259Q mutants were both retained but impaired to the same extent. This indicates that the enzymatic activity of this protein is essential but not a sole determinant of the antiviral activity. Furthermore, all the deletion mutants tested in this study lost the antiviral activity because of the loss of the activity for dimerization, suggesting that the entire protein structure is necessary for the antiviral function.

  2. Requirement of 8-mercaptoguanosine as a costimulus for IL-4-dependent μ to γ1 class switch recombination in CD38-activated B cells

    International Nuclear Information System (INIS)

    Tsukamoto, Yumiko; Uehara, Shoji; Mizoguchi, Chieko; Sato, Atsushi; Horikawa, Keisuke; Takatsu, Kiyoshi

    2005-01-01

    Mature B-2 cells expressing surface IgM and IgD proliferate upon stimulation by CD38, CD40 or lipopolysaccharide (LPS) and differentiate into IgG1-producing plasma cells in the presence of cytokines. The process of class switch recombination (CSR) from IgM to other isotypes is highly regulated by cytokines and activation-induced cytidine deaminase (AID). Blimp-1 and XBP-1 play an essential role in the terminal differentiation of switched B-2 cells to Ig-producing plasma cells. IL-5 induces AID and Blimp-1 expression in CD38- and CD40-activated B-2 cells, leading to μ to γ1 CSR at DNA level and IgG1 production. IL-4, a well-known IgG1-inducing factor, does not induce μ to γ1 CSR in CD38-activated B-2 cells or Blimp-1, while IL-4 induces μ to γ1 CSR, XBP-1 expression, and IgG1 production expression in CD40-activated B-2 cells. Interestingly, the addition of 8-mercaptoguanosine (8-SGuo) with IL-4 to the culture of CD38-activated B cells can induce μ to γ1 CSR, Blimp-1 expression, and IgG1 production. Intriguingly, 8-SGuo by itself induces AID expression in CD38-activated B cells. However, it does not induce μ to γ1 CSR. These results imply that the mode of B-cell activation for extracellular stimulation affects the outcome of cytokine stimulation with respect to the efficiency and direction of CSR, and the requirements of the transcriptional regulator and the generation of antibody-secreting cells. Furthermore, our data suggest the requirement of additional molecules in addition to AID for CSR

  3. Molecular Analysis of Activation-Induced Cytidine Deaminase Gene in Immunoglobulin-E Deficient Patients

    Directory of Open Access Journals (Sweden)

    Sergio Roa

    2008-01-01

    Full Text Available Understanding how class switch recombination (CSR is regulated to produce immunoglobulin E (IgE has become fundamental because of the dramatic increase in the prevalence of IgE-mediated hypersensitivity reactions. CSR requires the induction of the enzyme AICDA in B cells. Mutations in AICDA have been linked to Hyper-IgM syndrome (HIGM2, which shows absence of switching to IgE as well as to IgG and IgA. Although isolated IgE deficiency is a rare entity, here we show some individuals with normal serum IgM, IgG, and IgA levels that had undetectable total serum IgE levels. We have analyzed the AICDA gene in these individuals to determine if there are mutations in AICDA that could lead to selective IgE deficiency. Conformational sensitive gel electrophoresis (CSGE and sequencing analysis of AICDA coding sequences demonstrated sequence heterogeneity due to 5923A/G and 7888C/T polymorphisms, but did not reveal any novel mutation that might explain the selective IgE deficit.

  4. Enzymatically Active APOBEC3G Is Required for Efficient Inhibition of Human Immunodeficiency Virus Type 1▿

    OpenAIRE

    Miyagi, Eri; Opi, Sandrine; Takeuchi, Hiroaki; Khan, Mohammad; Goila-Gaur, Ritu; Kao, Sandra; Strebel, Klaus

    2007-01-01

    APOBEC3G (APO3G) is a cellular cytidine deaminase with potent antiviral activity. Initial studies of the function of APO3G demonstrated extensive mutation of the viral genome, suggesting a model in which APO3G's antiviral activity is due to hypermutation of the viral genome. Recent studies, however, found that deaminase-defective APO3G mutants transiently expressed in virus-producing cells exhibited significant antiviral activity, suggesting that the antiviral activity of APO3G could be disso...

  5. Pro-inflammatory activated Kupffer cells by lipids induce hepatic NKT cells deficiency through activation-induced cell death.

    Directory of Open Access Journals (Sweden)

    Tongfang Tang

    Full Text Available BACKGROUND: Dietary lipids play an important role in the progression of non-alcoholic fatty liver disease (NAFLD through alternation of liver innate immune response. AIMS: The present study was to investigate the effect of lipid on Kupffer cells phenotype and function in vivo and in vitro. And further to investigate the impact of lipid on ability of Kupffer cell lipid antigen presentation to activate NKT cells. METHODS: Wild type male C57BL/6 mice were fed either normal or high-fat diet. Hepatic steatosis, Kupffer cell abundance, NKT cell number and cytokine gene expression were evaluated. Antigen presentation assay was performed with Kupffer cells treated with certain fatty acids in vitro and co-cultured with NKT cells. RESULTS: High-fat diet induced hepatosteatosis, significantly increased Kupffer cells and decreased hepatic NKT cells. Lipid treatment in vivo or in vitro induced increase of pro-inflammatory cytokines gene expression and toll-like receptor 4 (TLR4 expression in Kupffer cells. Kupffer cells expressed high levels of CD1d on cell surface and only presented exogenous lipid antigen to activate NKT cells. Ability of Kupffer cells to present antigen and activate NKT cells was enhanced after lipid treatment. In addition, pro-inflammatory activated Kupffer cells by lipid treatment induced hepatic NKT cells activation-induced apoptosis and necrosis. CONCLUSION: High-fat diet increase Kupffer cells number and induce their pro-inflammatory status. Pro-inflammatory activated Kupfffer cells by lipid promote hepatic NKT cell over-activation and cell death, which lead to further hepatic NKT cell deficiency in the development of NAFLD.

  6. Pro-inflammatory activated Kupffer cells by lipids induce hepatic NKT cells deficiency through activation-induced cell death.

    Science.gov (United States)

    Tang, Tongfang; Sui, Yongheng; Lian, Min; Li, Zhiping; Hua, Jing

    2013-01-01

    Dietary lipids play an important role in the progression of non-alcoholic fatty liver disease (NAFLD) through alternation of liver innate immune response. The present study was to investigate the effect of lipid on Kupffer cells phenotype and function in vivo and in vitro. And further to investigate the impact of lipid on ability of Kupffer cell lipid antigen presentation to activate NKT cells. Wild type male C57BL/6 mice were fed either normal or high-fat diet. Hepatic steatosis, Kupffer cell abundance, NKT cell number and cytokine gene expression were evaluated. Antigen presentation assay was performed with Kupffer cells treated with certain fatty acids in vitro and co-cultured with NKT cells. High-fat diet induced hepatosteatosis, significantly increased Kupffer cells and decreased hepatic NKT cells. Lipid treatment in vivo or in vitro induced increase of pro-inflammatory cytokines gene expression and toll-like receptor 4 (TLR4) expression in Kupffer cells. Kupffer cells expressed high levels of CD1d on cell surface and only presented exogenous lipid antigen to activate NKT cells. Ability of Kupffer cells to present antigen and activate NKT cells was enhanced after lipid treatment. In addition, pro-inflammatory activated Kupffer cells by lipid treatment induced hepatic NKT cells activation-induced apoptosis and necrosis. High-fat diet increase Kupffer cells number and induce their pro-inflammatory status. Pro-inflammatory activated Kupfffer cells by lipid promote hepatic NKT cell over-activation and cell death, which lead to further hepatic NKT cell deficiency in the development of NAFLD.

  7. The effect of cytidine-diphosphate choline (CDP-choline) on brain lipid changes during aging

    International Nuclear Information System (INIS)

    De Medio, G.E.; Trovarelli, G.; Piccinin, G.L.; Porcellati, G.

    1984-01-01

    Lipid synthesis has been tested in vivo in different brain areas of 12-month-old male rats. Cortex, striatum, brainstem, and subcortex of brain have been examined. The cerebellum was discarded. Mixtures of (2- 3 H)glycerol and (Me- 14 C)choline were injected into the lateral ventricle of the brain as lipid precursors, and their incorporation into total lipid, water-soluble intermediates and choline-containing phospholipids was examined 1 hr after isotope injection. In another series of experiments cytidine-5'-diphosphate choline (CDP-choline) was injected intraventricularly to the aged rats 10 min before sacrifice with a simultaneous injection, and radioactivity assays were performed as above. Distribution of radioactivity content of CDP-choline among brain areas 10 min after its administration showed a noticeable enrichment of the nucleotide and water-soluble-related compounds in the examined areas, but to a lesser degree in the cerebral cortex. The incorporation of labelled glycerol, which is severely depressed in aged rats in all four areas [Gaiti et al, 1982, 1983], was increased only in the cortex, and apparently decreased in the other areas. This last result is probably due to a dilution effect brought about by the administered cold CDP-choline upon the ( 14 C)-containing water-soluble metabolites. As a consequence, the ( 3 H)/( 14 C) ratio in total lipid and in isolated phosphatidylcholine and choline plasmalogen increased after CDP-choline treatment

  8. Cyclopentenyl cytosine induces apoptosis and increases cytarabine-induced apoptosis in a T-lymphoblastic leukemic cell-line

    NARCIS (Netherlands)

    Verschuur, A. C.; Brinkman, J.; van Gennip, A. H.; Leen, R.; Vet, R. J.; Evers, L. M.; Voûte, P. A.; van Kuilenburg, A. B.

    2001-01-01

    Cyclopentenyl cytosine (CPEC) is a nucleoside-analogue that decreases the concentrations of cytidine triphosphate (CTP) and deoxycytidine triphosphate (dCTP) in leukemic cells by inhibiting the enzyme CTP synthetase, resulting in a decreased synthesis of RNA and DNA. Low concentrations of dCTP

  9. Analgesic effect of Minocycline in rat model of inflammation-induced visceral pain

    Science.gov (United States)

    Kannampalli, Pradeep; Pochiraju, Soumya; Bruckert, Mitchell; Shaker, Reza; Banerjee, Banani; Sengupta, Jyoti N.

    2014-01-01

    The present study investigates the analgesic effect of minocycline, a semi-synthetic tetracycline antibiotic, in a rat model of inflammation-induced visceral pain. Inflammation was induced in male rats by intracolonic administration of tri-nitrobenzenesulphonic acid (TNBS). Visceral hyperalgesia was assessed by comparing the viscero-motor response (VMR) to graded colorectal distension (CRD) prior and post 7 days after TNBS treatment. Electrophysiology recordings from CRD-sensitive pelvic nerve afferents (PNA) and lumbo-sacral (LS) spinal neurons were performed in naïve and inflamed rats. Colonic inflammation produced visceral hyperalgesia characterized by increase in the VMRs to CRD accompanied with simultaneous activation of microglia in the spinal cord and satellite glial cells (SGCs) in the dorsal root ganglions (DRGs). Selectively inhibiting the glial activation following inflammation by araC (Arabinofuranosyl Cytidine) prevented the development of visceral hyperalgesia. Intrathecal minocycline significantly attenuated the VMR to CRD in inflamed rats, whereas systemic minocycline produced a delayed effect. In electrophysiology experiments, minocycline significantly attenuated the mechanotransduction of CRD-sensitive PNAs and the responses of CRD-sensitive LS spinal neurons in TNBS-treated rats. While the spinal effect of minocycline was observed within 5 min of administration, systemic injection of the drug produced a delayed effect (60 min) in inflamed rats. Interestingly, minocycline did not exhibit analgesic effect in naïve, non-inflamed rats. The results demonstrate that intrathecal injection of minocycline can effectively attenuate inflammation-induced visceral hyperalgesia. Minocycline might as well act on neuronal targets in the spinal cord of inflamed rats, in addition to the widely reported glial inhibitory action to produce analgesia. PMID:24485889

  10. Distribution of induced activity in tungsten targets

    International Nuclear Information System (INIS)

    Donahue, R.J.; Nelson, W.R.

    1988-09-01

    Estimates are made of the induced activity created during high-energy electron showers in tungsten, using the EGS4 code. Photon track lengths, neutron yields and spatial profiles of the induced activity are presented. 8 refs., 9 figs., 1 tab

  11. Cytidine 5’-diphosphocholine administration prevents peripheral neuropathic pain after sciatic nerve crush injury in rats

    Directory of Open Access Journals (Sweden)

    Emril DR

    2016-05-01

    Full Text Available Dessy R Emril,1 Samekto Wibowo,2 Lucas Meliala,2 Rina Susilowati3 1Department of Neurology, Faculty of Medicine, Syiah Kuala University, Banda Aceh, 2Department of Neurology, 3Department of Histology and Cell Biology, Faculty of Medicine, Universitas Gadjah Mada, Yogyakarta, IndonesiaBackground: Cytidine 5’-diphosphocholine (citicoline has been shown to have beneficial effects in central nervous system injury as well as in motoric functional recovery after peripheral nerve injury. This study aimed to examine the effect of citicoline on prevention of neuropathic pain in a rat model of sciatic nerve crush injury.Methods: Forty experimental rats were divided into four groups. In three groups, the right sciatic nerves were crushed in the mid-thigh region, and a gelatin sponge moistened with 0.4 or 0.8 mL of 100 µmol/L citicoline, or saline 0.4 mL in the control group, was applied. The fourth group of rats was sham-operated, ie the sciatic nerve was exposed with no crush. Functional assessments were performed 4 weeks after crush injury. von Frey filaments (100 g threshold were used to assess neuropathic pain. In addition, the sciatic functional index and extensor postural thrust (EPT tests were used to assess motoric function.Results: The crush/citicoline 0.4 mL group had a lower percentage of pain (23.53%, n=17 compared with the crush/saline group (53.33%, n=15, P<0.005. The crush/citicoline 0.4 mL group also showed better motoric recovery, as seen in stronger EPT results (P<0.001. However, the sciatic functional index analysis did not show significant differences between groups (P=0.35. The crush/citicoline 0.8 mL group showed a higher percentage of pain (66.67%, n=18 and less EPT recovery. These results may be explained by more severe nerve injury due to compression with a larger administered volume.Conclusion: In situ administration of 0.4 mL of 100 μmol/L citicoline prevents the occurrence of neuropathic pain and induces motoric recovery

  12. A robust quantitative solid phase immunoassay for the acute phase protein C-reactive protein (CRP) based on cytidine 5 '-diphosphocholine coupled dendrimers

    DEFF Research Database (Denmark)

    Heegaard, Peter M. H.; Pedersen, H. G.; Jensen, A. L.

    2009-01-01

    C-reactive protein (CRP) is an important acute phase protein, being used as a sensitive indicator of inflammation and infection and is also associated with the risk of cardiovascular problems. The present paper describes a robust and sensitive ELISA for CRP, based on the affinity of CRP for phosp......C-reactive protein (CRP) is an important acute phase protein, being used as a sensitive indicator of inflammation and infection and is also associated with the risk of cardiovascular problems. The present paper describes a robust and sensitive ELISA for CRP, based on the affinity of CRP...... was applied to determination of pig and human CRP using commercially available antibodies against human CRP. The assay was shown to be more sensitive than previously published immunoassays employing albumin-coupled cytidine diphosphocholine. The coating was stable for at least 30 days at room temperature...

  13. Enhanced stimulus-induced gamma activity in humans during propofol-induced sedation.

    Directory of Open Access Journals (Sweden)

    Neeraj Saxena

    Full Text Available Stimulus-induced gamma oscillations in the 30-80 Hz range have been implicated in a wide number of functions including visual processing, memory and attention. While occipital gamma-band oscillations can be pharmacologically modified in animal preparations, pharmacological modulation of stimulus-induced visual gamma oscillations has yet to be demonstrated in non-invasive human recordings. Here, in fifteen healthy humans volunteers, we probed the effects of the GABAA agonist and sedative propofol on stimulus-related gamma activity recorded with magnetoencephalography, using a simple visual grating stimulus designed to elicit gamma oscillations in the primary visual cortex. During propofol sedation as compared to the normal awake state, a significant 60% increase in stimulus-induced gamma amplitude was seen together with a 94% enhancement of stimulus-induced alpha suppression and a simultaneous reduction in the amplitude of the pattern-onset evoked response. These data demonstrate, that propofol-induced sedation is accompanied by increased stimulus-induced gamma activity providing a potential window into mechanisms of gamma-oscillation generation in humans.

  14. Activating PTEN by COX-2 inhibitors antagonizes radiation-induced AKT activation contributing to radiosensitization

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Zhen [Central Laboratory, Peking University School and Hospital of Stomatology, 22 Zhongguancun Avenue South, Haidian District, Beijing 100081 (China); Department of Oral & Maxillofacial Surgery, Peking University School and Hospital of Stomatology, 22 Zhongguancun Avenue South, Haidian District, Beijing 100081 (China); Gan, Ye-Hua, E-mail: kqyehuagan@bjmu.edu.cn [Central Laboratory, Peking University School and Hospital of Stomatology, 22 Zhongguancun Avenue South, Haidian District, Beijing 100081 (China); Department of Oral & Maxillofacial Surgery, Peking University School and Hospital of Stomatology, 22 Zhongguancun Avenue South, Haidian District, Beijing 100081 (China)

    2015-05-01

    Radiotherapy is still one of the most effective nonsurgical treatments for many tumors. However, radioresistance remains a major impediment to radiotherapy. Although COX-2 inhibitors can induce radiosensitization, the underlying mechanism is not fully understood. In this study, we showed that COX-2 selective inhibitor celecoxib enhanced the radiation-induced inhibition of cell proliferation and apoptosis in HeLa and SACC-83 cells. Treatment with celecoxib alone dephosphorylated phosphatase and tensin homolog deleted on chromosome ten (PTEN), promoted PTEN membrane translocation or activation, and correspondingly dephosphorylated or inactivated protein kinase B (AKT). By contrast, treatment with radiation alone increased PTEN phosphorylation, inhibited PTEN membrane translocation and correspondingly activated AKT in the two cell lines. However, treatment with celecoxib or another COX-2 selective inhibitor (valdecoxib) completely blocked radiation-induced increase of PTEN phosphorylation, rescued radiation-induced decrease in PTEN membrane translocation, and correspondingly inactivated AKT. Moreover, celecoxib could also upregulate PTEN protein expression by downregulating Sp1 expression, thereby leading to the activation of PTEN transcription. Our results suggested that COX-2 inhibitors could enhance radiosensitization at least partially by activating PTEN to antagonize radiation-induced AKT activation. - Highlights: • COX-2 inhibitor, celecoxib, could enhance radiosensitization. • Radiation induced PTEN inactivation (phosphorylation) and AKT activation. • COX-2 inhibitor induced PTEN expression and activation, and inactivated AKT. • COX-2 inhibitor enhanced radiosensitization through activating PTEN.

  15. Synthesis, hybridization characteristics, and fluorescence properties of oligonucleotides modified with nucleobase-functionalized locked nucleic acid adenosine and cytidine monomers.

    Science.gov (United States)

    Kaura, Mamta; Kumar, Pawan; Hrdlicka, Patrick J

    2014-07-03

    Conformationally restricted nucleotides such as locked nucleic acid (LNA) are very popular as affinity-, specificity-, and stability-enhancing modifications in oligonucleotide chemistry to produce probes for nucleic acid targeting applications in molecular biology, biotechnology, and medicinal chemistry. Considerable efforts have been devoted in recent years to optimize the biophysical properties of LNA through additional modification of the sugar skeleton. We recently introduced C5-functionalization of LNA uridines as an alternative and synthetically more straightforward approach to improve the biophysical properties of LNA. In the present work, we set out to test the generality of this concept by studying the characteristics of oligonucleotides modified with four different C5-functionalized LNA cytidine and C8-functionalized LNA adenosine monomers. The results strongly suggest that C5-functionalization of LNA pyrimidines is indeed a viable approach for improving the binding affinity, target specificity, and/or enzymatic stability of LNA-modified ONs, whereas C8-functionalization of LNA adenosines is detrimental to binding affinity and specificity. These insights will impact the future design of conformationally restricted nucleotides for nucleic acid targeting applications.

  16. Solubility of disodium cytidine 5′-monophosphate in different binary mixtures from 288.15 K to 313.15 K

    International Nuclear Information System (INIS)

    Yu, Jin; Ma, Tianle; Li, An; Chen, Xiaochun; Chen, Yong; Xie, Jingjing; Wu, Jinglan; Ying, Hanjie

    2013-01-01

    Highlights: • Solubility of 5′-CMPNa 2 in different systems was measured the first time. • Experimental data were correlated by CNIBS/Redlich–Kister model and Apelblat model. • Good agreement has been observed between the calculated and the experimental data. • Enthalpy and entropy were calculated by the van’t Hoff equation and Gibbs equation. - Abstract: The solubility of disodium cytidine 5′-monophosphate (5′-CMPNa 2 ) in methanol + water and ethanol + water binary mixtures was measured experimentally at the temperatures ranging from 288.15 to 313.15 K. The results showed that the solubility of 5′-CMPNa 2 increased with the increasing of temperature and the mole fraction of water in different binary mixtures. The (CNIBS)/Redlich–Kister model and the semi-empirical Apelblat model were applied for the prediction of the experimental data. Both models could give satisfactory simulation results. In addition, the thermodynamic properties of the dissolution process such as Gibbs energy, enthalpy, and entropy were calculated using the van’t Hoff equation and the Gibbs equation. The results indicated that the dissolution process was endothermic

  17. Activating AMP-activated protein kinase by an α1 selective activator compound 13 attenuates dexamethasone-induced osteoblast cell death

    International Nuclear Information System (INIS)

    Guo, Shiguang; Mao, Li; Ji, Feng; Wang, Shouguo; Xie, Yue; Fei, Haodong; Wang, Xiao-dong

    2016-01-01

    Excessive glucocorticoid (GC) usage may lead to non-traumatic femoral head osteonecrosis. Dexamethasone (Dex) exerts cytotoxic effect to cultured osteoblasts. Here, we investigated the potential activity of Compound 13 (C13), a novel α1 selective AMP-activated protein kinase (AMPK) activator, against the process. Our data revealed that C13 pretreatment significantly attenuated Dex-induced apoptosis and necrosis in both osteoblastic-like MC3T3-E1 cells and primary murine osteoblasts. AMPK activation mediated C13′ cytoprotective effect in osteoblasts. The AMPK inhibitor Compound C, shRNA-mediated knockdown of AMPKα1, or dominant negative mutation of AMPKα1 (T172A) almost abolished C13-induced AMPK activation and its pro-survival effect in osteoblasts. On the other hand, forced AMPK activation by adding AMPK activator A-769662 or exogenous expression a constitutively-active (ca) AMPKα1 (T172D) mimicked C13's actions and inhibited Dex-induced osteoblast cell death. Meanwhile, A-769662 or ca-AMPKα1 almost nullified C13's activity in osteoblast. Further studies showed that C13 activated AMPK-dependent nicotinamide adenine dinucleotide phosphate (NADPH) pathway to inhibit Dex-induced reactive oxygen species (ROS) production in MC3T3-E1 cells and primary murine osteoblasts. Such effects by C13 were almost reversed by Compound C or AMPKα1 depletion/mutation. Together, these results suggest that C13 alleviates Dex-induced osteoblast cell death via activating AMPK signaling pathway. - Highlights: • Compound 13 (C13) attenuates dexamethasone (Dex)-induced osteoblast cell death. • C13-induced cytoprotective effect against Dex in osteoblasts requires AMPK activation. • Forced AMPK activation protects osteoblasts from Dex, nullifying C13's activities. • C13 increases NADPH activity and inhibits Dex-induced oxidative stress in osteoblasts.

  18. Activating AMP-activated protein kinase by an α1 selective activator compound 13 attenuates dexamethasone-induced osteoblast cell death

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Shiguang [Department of Intensive Care Unit, Huai' an First People' s Hospital, Nanjing Medical University, Huai' an (China); Mao, Li [Department of Endocrinology, Huai' an First People' s Hospital, Nanjing Medical University, Huai' an (China); Ji, Feng, E-mail: huaiaifengjidr@163.com [Department of Orthopedics, Huai' an First People' s Hospital, Nanjing Medical University, Huai' an (China); Wang, Shouguo; Xie, Yue; Fei, Haodong [Department of Orthopedics, Huai' an First People' s Hospital, Nanjing Medical University, Huai' an (China); Wang, Xiao-dong, E-mail: xiaodongwangsz@163.com [The Center of Diagnosis and Treatment for Children' s Bone Diseases, The Children' s Hospital Affiliated to Soochow University, Suzhou (China)

    2016-03-18

    Excessive glucocorticoid (GC) usage may lead to non-traumatic femoral head osteonecrosis. Dexamethasone (Dex) exerts cytotoxic effect to cultured osteoblasts. Here, we investigated the potential activity of Compound 13 (C13), a novel α1 selective AMP-activated protein kinase (AMPK) activator, against the process. Our data revealed that C13 pretreatment significantly attenuated Dex-induced apoptosis and necrosis in both osteoblastic-like MC3T3-E1 cells and primary murine osteoblasts. AMPK activation mediated C13′ cytoprotective effect in osteoblasts. The AMPK inhibitor Compound C, shRNA-mediated knockdown of AMPKα1, or dominant negative mutation of AMPKα1 (T172A) almost abolished C13-induced AMPK activation and its pro-survival effect in osteoblasts. On the other hand, forced AMPK activation by adding AMPK activator A-769662 or exogenous expression a constitutively-active (ca) AMPKα1 (T172D) mimicked C13's actions and inhibited Dex-induced osteoblast cell death. Meanwhile, A-769662 or ca-AMPKα1 almost nullified C13's activity in osteoblast. Further studies showed that C13 activated AMPK-dependent nicotinamide adenine dinucleotide phosphate (NADPH) pathway to inhibit Dex-induced reactive oxygen species (ROS) production in MC3T3-E1 cells and primary murine osteoblasts. Such effects by C13 were almost reversed by Compound C or AMPKα1 depletion/mutation. Together, these results suggest that C13 alleviates Dex-induced osteoblast cell death via activating AMPK signaling pathway. - Highlights: • Compound 13 (C13) attenuates dexamethasone (Dex)-induced osteoblast cell death. • C13-induced cytoprotective effect against Dex in osteoblasts requires AMPK activation. • Forced AMPK activation protects osteoblasts from Dex, nullifying C13's activities. • C13 increases NADPH activity and inhibits Dex-induced oxidative stress in osteoblasts.

  19. Effects of scallop shell extract on scopolamine-induced memory impairment and MK801-induced locomotor activity.

    Science.gov (United States)

    Hasegawa, Yasushi; Inoue, Tatsuro; Kawaminami, Satoshi; Fujita, Miho

    2016-07-01

    To evaluate the neuroprotective effects of the organic components of scallop shells (scallop shell extract) on memory impairment and locomotor activity induced by scopolamine or 5-methyl-10,11-dihydro-5H-dibenzo (a,d) cyclohepten-5,10-imine (MK801). Effect of the scallop shell extract on memory impairment and locomotor activity was investigated using the Y-maze test, the Morris water maze test, and the open field test. Scallop shell extract significantly reduced scopolamine-induced short-term memory impairment and partially reduced scopolamine-induced spatial memory impairment in the Morris water maze test. Scallop shell extract suppressed scopolamine-induced elevation of acetylcholine esterase activity in the cerebral cortex. Treatment with scallop shell extract reversed the increase in locomotor activity induced by scopolamine. Scallop shell extract also suppressed the increase in locomotor activity induced by MK801. Our results provide initial evidence that scallop shell extract reduces scopolamine-induced memory impairment and suppresses MK-801-induced hyperlocomotion. Copyright © 2016 Hainan Medical College. Production and hosting by Elsevier B.V. All rights reserved.

  20. Uracil DNA glycosylase counteracts APOBEC3G-induced hypermutation of hepatitis B viral genomes: excision repair of covalently closed circular DNA.

    Directory of Open Access Journals (Sweden)

    Kouichi Kitamura

    Full Text Available The covalently closed circular DNA (cccDNA of the hepatitis B virus (HBV plays an essential role in chronic hepatitis. The cellular repair system is proposed to convert cytoplasmic nucleocapsid (NC DNA (partially double-stranded DNA into cccDNA in the nucleus. Recently, antiviral cytidine deaminases, AID/APOBEC proteins, were shown to generate uracil residues in the NC-DNA through deamination, resulting in cytidine-to-uracil (C-to-U hypermutation of the viral genome. We investigated whether uracil residues in hepadnavirus DNA were excised by uracil-DNA glycosylase (UNG, a host factor for base excision repair (BER. When UNG activity was inhibited by the expression of the UNG inhibitory protein (UGI, hypermutation of NC-DNA induced by either APOBEC3G or interferon treatment was enhanced in a human hepatocyte cell line. To assess the effect of UNG on the cccDNA viral intermediate, we used the duck HBV (DHBV replication model. Sequence analyses of DHBV DNAs showed that cccDNA accumulated G-to-A or C-to-T mutations in APOBEC3G-expressing cells, and this was extensively enhanced by UNG inhibition. The cccDNA hypermutation generated many premature stop codons in the P gene. UNG inhibition also enhanced the APOBEC3G-mediated suppression of viral replication, including reduction of NC-DNA, pre-C mRNA, and secreted viral particle-associated DNA in prolonged culture. Enhancement of APOBEC3G-mediated suppression by UNG inhibition was not observed when the catalytic site of APOBEC3G was mutated. Transfection experiments of recloned cccDNAs revealed that the combination of UNG inhibition and APOBEC3G expression reduced the replication ability of cccDNA. Taken together, these data indicate that UNG excises uracil residues from the viral genome during or after cccDNA formation in the nucleus and imply that BER pathway activities decrease the antiviral effect of APOBEC3-mediated hypermutation.

  1. Shock-induced electrical activity in polymeric solids. A mechanically induced bond scission model

    International Nuclear Information System (INIS)

    Graham, R.A.

    1979-01-01

    When polymeric solids are subjected to high-pressure shock loading, two anomalous electrical phenomena, shock-induced conduction and shock-induced polarization, are observed. The present paper proposes a model of mechanically induced bond scission within the shock front to account for the effects. An experimental study of shock-induced polarization in poly(pyromellitimide) (Vespel SP-1) is reported for shock compressions from 17 to 23% (pressures from 2.5 to 5.4 GPa). Poly(pyromellitimide) is found to be a strong generator of such polarization and the polarization is found to reflect an irreversible or highly hysteretic process. The present measurements are combined with prior measurements to establish a correlation between monomer structure and strength of shock-induced polarization; feeble signals are observed in the simpler monomer repeat units of poly(tetrafluoroethylene) and polyethylene while the strongest signals are observed in more complex monomers of poly(methyl methacrylate) and poly(pyromellitimide). It is also noted that there is an apparent correlation between shock-induced conduction and shock-induced polarization. Such shock-induced electrical activity is also found to be well correlated with the propensity for mechanical bond scission observed in experiments carried out in conventional mechanochemical studies. The bond scission model can account for characteristics observed for electrical activity in shock-loaded polymers and their correlation to monomer structure. Localization of elastic energy within the monomer repeat unit or along the main chain leads to the different propensities for bond scission and resulting shock-induced electrical activity

  2. Activation of peripheral blood mononuclear cells by dengue virus infection depotentiates balapiravir.

    Science.gov (United States)

    Chen, Yen-Liang; Abdul Ghafar, Nahdiyah; Karuna, Ratna; Fu, Yilong; Lim, Siew Pheng; Schul, Wouter; Gu, Feng; Herve, Maxime; Yokohama, Fumiaki; Wang, Gang; Cerny, Daniela; Fink, Katja; Blasco, Francesca; Shi, Pei-Yong

    2014-02-01

    In a recent clinical trial, balapiravir, a prodrug of a cytidine analog (R1479), failed to achieve efficacy (reducing viremia after treatment) in dengue patients, although the plasma trough concentration of R1479 remained above the 50% effective concentration (EC(50)). Here, we report experimental evidence to explain the discrepancy between the in vitro and in vivo results and its implication for drug development. R1479 lost its potency by 125-fold when balapiravir was used to treat primary human peripheral blood mononuclear cells (PBMCs; one of the major cells targeted for viral replication) that were preinfected with dengue virus. The elevated EC(50) was greater than the plasma trough concentration of R1479 observed in dengue patients treated with balapiravir and could possibly explain the efficacy failure. Mechanistically, dengue virus infection triggered PBMCs to generate cytokines, which decreased their efficiency of conversion of R1479 to its triphosphate form (the active antiviral ingredient), resulting in decreased antiviral potency. In contrast to the cytidine-based compound R1479, the potency of an adenosine-based inhibitor of dengue virus (NITD008) was much less affected. Taken together, our results demonstrate that viral infection in patients before treatment could significantly affect the conversion of the prodrug to its active form; such an effect should be calculated when estimating the dose efficacious for humans.

  3. SRSF1-3 contributes to diversification of the immunoglobulin variable region gene by promoting accumulation of AID in the nucleus

    OpenAIRE

    Kawaguchi, Yuka; Nariki, Hiroaki; Kawamoto, Naoko; Kanehiro, Yuichi; Miyazaki, Satoshi; Suzuki, Mari; Magari, Masaki; Tokumitsu, Hiroshi; Kanayama, Naoki

    2017-01-01

     Activation-induced cytidine deaminase (AID) is essential for diversification of the Ig variable region (IgV). AID is excluded from the nucleus, where it normally functions. However, the molecular mechanisms responsible for regulating AID localization remain to be elucidated. The SR-protein splicing factor SRSF1 is a nucleocytoplasmic shuttling protein, a splicing isoform of which called SRSF1-3, has previously been shown to contribute to IgV diversification in chicken DT40 cells. In this stu...

  4. APOBEC3G inhibits HIV-1 RNA elongation by inactivating the viral trans-activation response element.

    Science.gov (United States)

    Nowarski, Roni; Prabhu, Ponnandy; Kenig, Edan; Smith, Yoav; Britan-Rosich, Elena; Kotler, Moshe

    2014-07-29

    Deamination of cytidine residues in viral DNA is a major mechanism by which APOBEC3G (A3G) inhibits vif-deficient human immunodeficiency virus type 1 (HIV-1) replication. dC-to-dU transition following RNase-H activity leads to viral cDNA degradation, production of non-functional proteins, formation of undesired stop codons and decreased viral protein synthesis. Here, we demonstrate that A3G provides an additional layer of defense against HIV-1 infection dependent on inhibition of proviral transcription. HIV-1 transcription elongation is regulated by the trans-activation response (TAR) element, a short stem-loop RNA structure required for elongation factors binding. Vif-deficient HIV-1-infected cells accumulate short viral transcripts and produce lower amounts of full-length HIV-1 transcripts due to A3G deamination of the TAR apical loop cytidine, highlighting the requirement for TAR loop integrity in HIV-1 transcription. We further show that free single-stranded DNA (ssDNA) termini are not essential for A3G activity and a gap of CCC motif blocked with juxtaposed DNA or RNA on either or 3'+5' ends is sufficient for A3G deamination. These results identify A3G as an efficient mutator and that deamination of (-)SSDNA results in an early block of HIV-1 transcription. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. CTP limitation increases expression of CTP synthase in Lactococcus lactis

    DEFF Research Database (Denmark)

    Jørgensen, C.M.; Hammer, Karin; Martinussen, Jan

    2003-01-01

    CTP synthase is encoded by the pyrG gene and catalyzes the conversion of UTP to CTP. A Lactococcus lactis pyrG mutant with a cytidine requirement was constructed, in which beta-galactosidase activity in a pyrG-lacLM transcriptional fusion was used to monitor gene expression of pyrG. A 10-fold...... decrease in the CTP pool induced by cytidine limitation was found to immediately increase expression of the L. lactis pyrG gene. The final level of expression of pyrG is 37-fold higher than the uninduced level. CTP limitation has pronounced effects on central cellular metabolism, and both RNA and protein...... for regulation of the pyrG gene. It is possible to fold the pyrG leader in an alternative structure that would prevent the formation of the terminator. We suggest a model for pyrG regulation in L. lactis, and probably in other gram-positive bacteria as well, in which pyrG expression is directly dependent...

  6. Activation of Nrf2 protects against triptolide-induced hepatotoxicity.

    Directory of Open Access Journals (Sweden)

    Jia Li

    Full Text Available Triptolide, the major active component of Tripterygium wilfordii Hook f. (TWHF, has a wide range of pharmacological activities. However, the toxicities of triptolide, particularly the hepatotoxicity, limit its clinical application. The hepatotoxicity of triptolide has not been well characterized yet. The aim of this study was to investigate the role of NF-E2-related factor 2 (Nrf2 in triptolide-induced toxicity and whether activation of Nrf2 could protect against triptolide-induced hepatotoxicity. The results showed that triptolide caused oxidative stress and cell damage in HepG2 cells, and these toxic effects could be aggravated by Nrf2 knockdown or be counteracted by overexpression of Nrf2. Treatment with a typical Nrf2 agonist, sulforaphane (SFN, attenuated triptolide-induced liver dysfunction, structural damage, glutathione depletion and decrease in antioxidant enzymes in BALB/C mice. Moreover, the hepatoprotective effect of SFN on triptolide-induced liver injury was associated with the activation of Nrf2 and its downstream targets. Collectively, these results indicate that Nrf2 activation protects against triptolide-induced hepatotoxicity.

  7. Activation of AMP-activated protein kinase by tributyltin induces neuronal cell death

    International Nuclear Information System (INIS)

    Nakatsu, Yusuke; Kotake, Yaichiro; Hino, Atsuko; Ohta, Shigeru

    2008-01-01

    AMP-activated protein kinase (AMPK), a member of the metabolite-sensing protein kinase family, is activated by energy deficiency and is abundantly expressed in neurons. The environmental pollutant, tributyltin chloride (TBT), is a neurotoxin, and has been reported to decrease cellular ATP in some types of cells. Therefore, we investigated whether TBT activates AMPK, and whether its activation contributes to neuronal cell death, using primary cultures of cortical neurons. Cellular ATP levels were decreased 0.5 h after exposure to 500 nM TBT, and the reduction was time-dependent. It was confirmed that most neurons in our culture system express AMPK, and that TBT induced phosphorylation of AMPK. Compound C, an AMPK inhibitor, reduced the neurotoxicity of TBT, suggesting that AMPK is involved in TBT-induced cell death. Next, the downstream target of AMPK activation was investigated. Nitric oxide synthase, p38 phosphorylation and Akt dephosphorylation were not downstream of TBT-induced AMPK activation because these factors were not affected by compound C, but glutamate release was suggested to be controlled by AMPK. Our results suggest that activation of AMPK by TBT causes neuronal death through mediating glutamate release

  8. EGFR Activation and Ultraviolet Light‐Induced Skin Carcinogenesis

    Directory of Open Access Journals (Sweden)

    Taghrid B. El-Abaseri

    2007-01-01

    Full Text Available The epidermal growth factor receptor (EGFR regulates the proliferation of keratinocytes through multiple mechanisms that differ depending on the localization of the cell within the skin. Ultraviolet (UV irradiation, the main etiologic factor in the development of skin cancer, also activates the receptor. In this review, we discuss how the UV-induced activation of EGFR regulates the response of the skin to UV. UV-induced EGFR activation increases keratinocyte proliferation, suppresses apoptosis, and augments and accelerates epidermal hyperplasia in response to UV. Pharmacological inhibition of the UV-induced activation of EGFR in a genetically initiated mouse skin tumorigenesis model suppresses tumorigenesis and the activation of mitogen-activated protein (MAP kinases and phosphatidyl inositol-3-kinase (PI3K/AKT signaling pathways. EGFR has pleiotropic, complex, and cell-type-specific functions in cutaneous keratinocytes; suggesting that the receptor is an appropriate target for the development of molecularly targeted therapies for skin cancer and other pathologies.

  9. Solubility of disodium cytidine 5′-monophosphate in different binary mixtures from 288.15 K to 313.15 K

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Jin [College of Biotechnology and Pharmaceutical Engineering, Nanjing University of Technology, Nanjing (China); National Engineering Technique Research Center for Biotechnology, Nanjing (China); Ma, Tianle; Li, An [National Engineering Technique Research Center for Biotechnology, Nanjing (China); State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing (China); Chen, Xiaochun; Chen, Yong; Xie, Jingjing [College of Biotechnology and Pharmaceutical Engineering, Nanjing University of Technology, Nanjing (China); National Engineering Technique Research Center for Biotechnology, Nanjing (China); Wu, Jinglan, E-mail: yinghanjie@njut.edu.cn [College of Biotechnology and Pharmaceutical Engineering, Nanjing University of Technology, Nanjing (China); National Engineering Technique Research Center for Biotechnology, Nanjing (China); Ying, Hanjie [College of Biotechnology and Pharmaceutical Engineering, Nanjing University of Technology, Nanjing (China); National Engineering Technique Research Center for Biotechnology, Nanjing (China); State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing (China)

    2013-08-10

    Highlights: • Solubility of 5′-CMPNa{sub 2} in different systems was measured the first time. • Experimental data were correlated by CNIBS/Redlich–Kister model and Apelblat model. • Good agreement has been observed between the calculated and the experimental data. • Enthalpy and entropy were calculated by the van’t Hoff equation and Gibbs equation. - Abstract: The solubility of disodium cytidine 5′-monophosphate (5′-CMPNa{sub 2}) in methanol + water and ethanol + water binary mixtures was measured experimentally at the temperatures ranging from 288.15 to 313.15 K. The results showed that the solubility of 5′-CMPNa{sub 2} increased with the increasing of temperature and the mole fraction of water in different binary mixtures. The (CNIBS)/Redlich–Kister model and the semi-empirical Apelblat model were applied for the prediction of the experimental data. Both models could give satisfactory simulation results. In addition, the thermodynamic properties of the dissolution process such as Gibbs energy, enthalpy, and entropy were calculated using the van’t Hoff equation and the Gibbs equation. The results indicated that the dissolution process was endothermic.

  10. Histone H3.3 promotes IgV gene diversification by?enhancing formation of AID?accessible single?stranded DNA

    OpenAIRE

    Romanello, Marina; Schiavone, Davide; Frey, Alexander; Sale, Julian E

    2016-01-01

    Abstract Immunoglobulin diversification is driven by activation?induced deaminase (AID), which converts cytidine to uracil within the Ig variable (IgV) regions. Central to the recruitment of AID to the IgV genes are factors that regulate the generation of single?stranded DNA (ssDNA), the enzymatic substrate of AID. Here, we report that chicken DT40 cells lacking variant histone H3.3 exhibit reduced IgV sequence diversification. We show that this results from impairment of the ability of AID t...

  11. High expression of AID and active class switch recombination might account for a more aggressive disease in unmutated CLL patients: link with an activated microenvironment in CLL disease.

    Science.gov (United States)

    Palacios, Florencia; Moreno, Pilar; Morande, Pablo; Abreu, Cecilia; Correa, Agustín; Porro, Valentina; Landoni, Ana Ines; Gabus, Raul; Giordano, Mirta; Dighiero, Guillermo; Pritsch, Otto; Oppezzo, Pablo

    2010-06-03

    Interaction of chronic lymphocytic leukemia (CLL) B cells with tissue microenvironment has been suggested to favor disease progression by promoting malignant B-cell growth. Previous work has shown expression in peripheral blood (PB) of CLL B cells of activation-induced cytidine deaminase (AID) among CLL patients with an unmutated (UM) profile of immunoglobulin genes and with ongoing class switch recombination (CSR) process. Because AID expression results from interaction with activated tissue microenvironment, we speculated whether the small subset with ongoing CSR is responsible for high levels of AID expression and could be derived from this particular microenvironment. In this work, we quantified AID expression and ongoing CSR in PB of 50 CLL patients and characterized the expression of different molecules related to microenvironment interaction. Our results show that among UM patients (1) high AID expression is restricted to the subpopulation of tumoral cells ongoing CSR; (2) this small subset expresses high levels of proliferation, antiapoptotic and progression markers (Ki-67, c-myc, Bcl-2, CD49d, and CCL3/4 chemokines). Overall, this work outlines the importance of a cellular subset in PB of UM CLL patients with a poor clinical outcome, high AID levels, and ongoing CSR, whose presence might be a hallmark of a recent contact with the microenvironment.

  12. Comparison of identical and functional Igh alleles reveals a nonessential role for Eμ in somatic hypermutation and class-switch recombination.

    Science.gov (United States)

    Li, Fubin; Yan, Yi; Pieretti, Joyce; Feldman, Danielle A; Eckhardt, Laurel A

    2010-11-15

    Somatic hypermutation (SHM), coupled with Ag selection, provides a mechanism for generating Abs with high affinity for invading pathogens. Class-switch recombination (CSR) ensures that these Abs attain pathogen-appropriate effector functions. Although the enzyme critical to both processes, activation-induced cytidine deaminase, has been identified, it remains unclear which cis-elements within the Ig loci are responsible for recruiting activation-induced cytidine deaminase and promoting its activity. Studies showed that Ig gene-transcription levels are positively correlated with the frequency of SHM and CSR, making the intronic, transcriptional enhancer Eμ a likely contributor to both processes. Tests of this hypothesis yielded mixed results arising, in part, from the difficulty in studying B cell function in mice devoid of Eμ. In Eμ's absence, V(H) gene assembly is dramatically impaired, arresting B cell development. The current study circumvented this problem by modifying the murine Igh locus through simultaneous insertion of a fully assembled V(H) gene and deletion of Eμ. The behavior of this allele was compared with that of a matched allele carrying the same V(H) gene but with Eμ intact. Although IgH transcription was as great or greater on the Eμ-deficient allele, CSR and SHM were consistently, but modestly, reduced relative to the allele in which Eμ remained intact. We conclude that Eμ contributes to, but is not essential for, these complex processes and that its contribution is not as a transcriptional enhancer but, rather, is at the level of recruitment and/or activation of the SHM/CSR machinery.

  13. Cold suppresses agonist-induced activation of TRPV1.

    Science.gov (United States)

    Chung, M-K; Wang, S

    2011-09-01

    Cold therapy is frequently used to reduce pain and edema following acute injury or surgery such as tooth extraction. However, the neurobiological mechanisms of cold therapy are not completely understood. Transient receptor potential vanilloid 1 (TRPV1) is a capsaicin- and heat-gated nociceptive ion channel implicated in thermosensation and pathological pain under conditions of inflammation or injury. Although capsaicin-induced nociception, neuropeptide release, and ionic currents are suppressed by cold, it is not known if cold suppresses agonist-induced activation of recombinant TRPV1. We demonstrate that cold strongly suppressed the activation of recombinant TRPV1 by multiple agonists and capsaicin-evoked currents in trigeminal ganglia neurons under normal and phosphorylated conditions. Cold-induced suppression was partially impaired in a TRPV1 mutant that lacked heat-mediated activation and potentiation. These results suggest that cold-induced suppression of TRPV1 may share a common molecular basis with heat-induced potentiation, and that allosteric inhibition may contribute, in part, to the cold-induced suppression. We also show that combination of cold and a specific antagonist of TRPV1 can produce an additive suppression. Our results provide a mechanistic basis for cold therapy and may enhance anti-nociceptive approaches that target TRPV1 for managing pain under inflammation and tissue injury, including that from tooth extraction.

  14. Activation of aryl hydrocarbon receptor reduces carbendazim-induced cell death

    International Nuclear Information System (INIS)

    Wei, Kuo-Liang; Chen, Fei-Yun; Lin, Chih-Yi; Gao, Guan-Lun; Kao, Wen-Ya; Yeh, Chi-Hui; Chen, Chang-Rong; Huang, Hao-Chun; Tsai, Wei-Ren; Jong, Koa-Jen; Li, Wan-Jung; Su, Jyan-Gwo Joseph

    2016-01-01

    Carbendazim inhibits microtubule assembly, thus blocking mitosis and inhibiting cancer cell proliferation. Accordingly, carbendazim is being explored as an anticancer drug. Data show that carbendazim increased mRNA and protein expressions and promoter activity of CYP1A1. In addition, carbendazim activated transcriptional activity of the aryl hydrocarbon response element, and induced nuclear translocation of the aryl hydrocarbon receptor (AhR), a sign the AhR is activated. Carbendazim-induced CYP1A1 expression was blocked by AhR antagonists, and was abolished in AhR signal-deficient cells. Results demonstrated that carbendazim activated the AhR, thereby stimulating CYP1A1 expression. In order to understand whether AhR-induced metabolic enzymes turn carbendazim into less-toxic metabolites, Hoechst 33342 staining to reveal carbendazim-induced nuclear changes and flow cytometry to reveal the subG 0 /G 1 population were applied to monitor carbendazim-induced cell apoptosis. Carbendazim induced less apoptosis in Hepa-1c1c7 cells than in AhR signal-deficient Hepa-1c1c7 mutant cells. Pretreatment with β-NF, an AhR agonist that highly induces CYP1A1 expression, decreased carbendazim-induced cell death. In addition, the lower the level of AhR was, the lower the vitality present in carbendazim-treated cells, including hepatoma cells and their derivatives with AhR RNA interference, also embryonic kidney cells, bladder carcinoma cells, and AhR signal-deficient Hepa-1c1c7 cells. In summary, carbendazim is an AhR agonist. The toxicity of carbendazim was lower in cells with the AhR signal. This report provides clues indicating that carbendazim is more potent at inducing cell death in tissues without than in those with the AhR signal, an important reference for applying carbendazim in cancer chemotherapy. - Highlights: • Carbendazim induced transcriptional activity of the aryl hydrocarbon response element. • Carbendazim induced nuclear translocation of the aryl hydrocarbon

  15. Activation of aryl hydrocarbon receptor reduces carbendazim-induced cell death

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Kuo-Liang [Division of Gastroenterology and Hepatology, Department of Internal Medicine, Chang Gung Memorial Hospital, Chiayi 61363, Taiwan, ROC (China); College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan, ROC (China); Chen, Fei-Yun; Lin, Chih-Yi [Department of Biochemical Science and Technology, National Chiayi University, Chiayi 60004, Taiwan, ROC (China); Gao, Guan-Lun [Department of Biochemical Science and Technology, National Chiayi University, Chiayi 60004, Taiwan, ROC (China); Department of Biological Resources, National Chiayi University, Chiayi, 60004, Taiwan, ROC (China); Kao, Wen-Ya [Department of Biochemical Science and Technology, National Chiayi University, Chiayi 60004, Taiwan, ROC (China); Yeh, Chi-Hui [Department of Environmental Engineering, College of Engineering, Da-Yeh University, Dacun, Changhua 51591, Taiwan, ROC (China); Chen, Chang-Rong [Department of Biochemical Science and Technology, National Chiayi University, Chiayi 60004, Taiwan, ROC (China); Huang, Hao-Chun [Division of Gastroenterology and Hepatology, Department of Internal Medicine, Chang Gung Memorial Hospital, Chiayi 61363, Taiwan, ROC (China); Tsai, Wei-Ren [Division of Applied Toxicology, Taiwan Agricultural Chemicals and Toxic Substances Research Institute, Council of Agriculture, Executive Yuan, Taichung 41358, Taiwan, ROC (China); Jong, Koa-Jen [Department of Biological Resources, National Chiayi University, Chiayi, 60004, Taiwan, ROC (China); Li, Wan-Jung [Department of Biochemical Science and Technology, National Chiayi University, Chiayi 60004, Taiwan, ROC (China); Su, Jyan-Gwo Joseph, E-mail: jgjsu@mail.ncyu.edu.tw [Department of Biochemical Science and Technology, National Chiayi University, Chiayi 60004, Taiwan, ROC (China)

    2016-09-01

    Carbendazim inhibits microtubule assembly, thus blocking mitosis and inhibiting cancer cell proliferation. Accordingly, carbendazim is being explored as an anticancer drug. Data show that carbendazim increased mRNA and protein expressions and promoter activity of CYP1A1. In addition, carbendazim activated transcriptional activity of the aryl hydrocarbon response element, and induced nuclear translocation of the aryl hydrocarbon receptor (AhR), a sign the AhR is activated. Carbendazim-induced CYP1A1 expression was blocked by AhR antagonists, and was abolished in AhR signal-deficient cells. Results demonstrated that carbendazim activated the AhR, thereby stimulating CYP1A1 expression. In order to understand whether AhR-induced metabolic enzymes turn carbendazim into less-toxic metabolites, Hoechst 33342 staining to reveal carbendazim-induced nuclear changes and flow cytometry to reveal the subG{sub 0}/G{sub 1} population were applied to monitor carbendazim-induced cell apoptosis. Carbendazim induced less apoptosis in Hepa-1c1c7 cells than in AhR signal-deficient Hepa-1c1c7 mutant cells. Pretreatment with β-NF, an AhR agonist that highly induces CYP1A1 expression, decreased carbendazim-induced cell death. In addition, the lower the level of AhR was, the lower the vitality present in carbendazim-treated cells, including hepatoma cells and their derivatives with AhR RNA interference, also embryonic kidney cells, bladder carcinoma cells, and AhR signal-deficient Hepa-1c1c7 cells. In summary, carbendazim is an AhR agonist. The toxicity of carbendazim was lower in cells with the AhR signal. This report provides clues indicating that carbendazim is more potent at inducing cell death in tissues without than in those with the AhR signal, an important reference for applying carbendazim in cancer chemotherapy. - Highlights: • Carbendazim induced transcriptional activity of the aryl hydrocarbon response element. • Carbendazim induced nuclear translocation of the aryl

  16. ORF Alignment: NC_004431 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available EDL933] pdb|1KDT|B Chain B, ... Cytidine Monophosphate Kinase From E.Coli In Complex ... With... 2',3'-Dideoxy-Cytidine Monophosphate pdb|1KDT|A ... Chain A, Cytidine Monophosphate Kinase From E.Coli...|1KDR|B Chain B, Cytidine Monophosphate Kinase From ... E.Coli In Complex With Ara-Cytidine Monophosp...hate ... pdb|1KDR|A Chain A, Cytidine Monophosphate Kinase From ... E.Coli In Complex With Ara

  17. ORF Alignment: NC_002655 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available EDL933] pdb|1KDT|B Chain B, ... Cytidine Monophosphate Kinase From E.Coli In Complex ... With... 2',3'-Dideoxy-Cytidine Monophosphate pdb|1KDT|A ... Chain A, Cytidine Monophosphate Kinase From E.Coli...|1KDR|B Chain B, Cytidine Monophosphate Kinase From ... E.Coli In Complex With Ara-Cytidine Monophosp...hate ... pdb|1KDR|A Chain A, Cytidine Monophosphate Kinase From ... E.Coli In Complex With Ara

  18. ORF Alignment: NC_002695 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available EDL933] pdb|1KDT|B Chain B, ... Cytidine Monophosphate Kinase From E.Coli In Complex ... With... 2',3'-Dideoxy-Cytidine Monophosphate pdb|1KDT|A ... Chain A, Cytidine Monophosphate Kinase From E.Coli...|1KDR|B Chain B, Cytidine Monophosphate Kinase From ... E.Coli In Complex With Ara-Cytidine Monophosp...hate ... pdb|1KDR|A Chain A, Cytidine Monophosphate Kinase From ... E.Coli In Complex With Ara

  19. ORF Alignment: NC_000913 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available EDL933] pdb|1KDT|B Chain B, ... Cytidine Monophosphate Kinase From E.Coli In Complex ... With... 2',3'-Dideoxy-Cytidine Monophosphate pdb|1KDT|A ... Chain A, Cytidine Monophosphate Kinase From E.Coli...|1KDR|B Chain B, Cytidine Monophosphate Kinase From ... E.Coli In Complex With Ara-Cytidine Monophosp...hate ... pdb|1KDR|A Chain A, Cytidine Monophosphate Kinase From ... E.Coli In Complex With Ara

  20. GSK621 activates AMPK signaling to inhibit LPS-induced TNFα production

    International Nuclear Information System (INIS)

    Wu, Yong-hong; Li, Quan; Li, Ping; Liu, Bei

    2016-01-01

    LPS stimulation in macrophages/monocytes induces TNFα production. We here tested the potential effect of GSK621, a novel AMP-activated protein kinase (AMPK) activator, against the process. In RAW264.7 macrophages, murine bone marrow-derived macrophages (BMDMs), and chronic obstructive pulmonary disease (COPD) patients' monocytes, GSK621 significantly inhibited LPS-induced TNFα protein secretion and mRNA synthesis. Inhibition of AMPK, through AMPKα shRNA knockdown or dominant negative mutation (T172A), almost abolished GSK621's suppression on TNFα in RAW264.7 cells. Reversely, forced-expression of a constitutively-active AMPKα (T172D) mimicked GSK621 actions and reduced LPS-induced TNFα production. Molecularly, GSK621 suppressed LPS-induced reactive oxygen species (ROS) production and nuclear factor kappa B (NFκB) activation. In vivo, GSK621 oral administration inhibited LPS-induced TNFα production and endotoxin shock in mice. In summary, GSK621 activates AMPK signaling to inhibit LPS-induced TNFα production in macrophages/monocytes. - Highlights: • GSK621 inhibits LPS-induced TNFα production/expression in RAW264.7 cells and BMDMs. • GSK621 inhibits LPS-induced TNFα production/expression in COPD patients' PBMCs. • GSK621's inhibition on TNFα production by LPS requires AMPK activation. • GSK621 inhibits LPS-induced ROS production and NFκB activation, dependent on AMPK. • GSK621 oral administration inhibits LPS-induced TNFα production and endotoxin shock in mice.

  1. Salicylate-induced abnormal activity in the inferior colliculus of rats.

    Science.gov (United States)

    Chen, G D; Jastreboff, P J

    1995-02-01

    The evaluation of the spontaneous activity of 471 units from the external nucleus of the IC revealed that salicylate induces an increase of the spontaneous activity and the emergence of a bursting type of activity longer than 4 spikes. For sharply tuned units, the affected cells were from the frequency range of 10-16 kHz, which corresponds to the behaviorally measured pitch of salicylate-induced tinnitus in rats. An exogenous calcium supplement, provided under the conditions shown to attenuate the behavioral manifestation of salicylate-induced tinnitus, abolished the modification of the spontaneous activity induced by salicylate. Finally, profound changes of activity were observed for cells not responding to contralateral sound. We propose that the observed long bursts of discharges represent tinnitus-related neuronal activity. The results are consistent with the hypothesis that GABA-mediated disinhibition is involved in the processing of tinnitus-related neuronal activity.

  2. Effects of Parecoxib and Fentanyl on nociception-induced cortical activity

    Directory of Open Access Journals (Sweden)

    Wang Ying-Wei

    2010-01-01

    Full Text Available Abstract Background Analgesics, including opioids and non-steroid anti-inflammatory drugs reduce postoperative pain. However, little is known about the quantitative effects of these drugs on cortical activity induced by nociceptive stimulation. The aim of the present study was to determine the neural activity in response to a nociceptive stimulus and to investigate the effects of fentanyl (an opioid agonist and parecoxib (a selective cyclooxygenase-2 inhibitor on this nociception-induced cortical activity evoked by tail pinch. Extracellular recordings (electroencephalogram and multi-unit signals were performed in the area of the anterior cingulate cortex while intracellular recordings were made in the primary somatosensory cortex. The effects of parecoxib and fentanyl on induced cortical activity were compared. Results Peripheral nociceptive stimulation in anesthetized rats produced an immediate electroencephalogram (EEG desynchronization resembling the cortical arousal (low-amplitude, fast-wave activity, while the membrane potential switched into a persistent depolarization state. The induced cortical activity was abolished by fentanyl, and the fentanyl's effect was reversed by the opioid receptor antagonist, naloxone. Parecoxib, on the other hand, did not significantly affect the neural activity. Conclusion Cortical activity was modulated by nociceptive stimulation in anesthetized rats. Fentanyl showed a strong inhibitory effect on the nociceptive-stimulus induced cortical activity while parecoxib had no significant effect.

  3. A single intranasal immunization with a subunit vaccine formulation induces higher mucosal IgA production than live respiratory syncytial virus

    International Nuclear Information System (INIS)

    Garg, Ravendra; Theaker, Michael; Martinez, Elisa C.; Drunen Littel-van den Hurk, Sylvia van

    2016-01-01

    Respiratory syncytial virus (RSV) causes serious respiratory illness in infants and elderly. RSV infection induces short-lived immunity, which leaves people prone to re-infection. In contrast, the RSV fusion (F) protein formulated with a novel adjuvant (∆F/TriAdj) elicits long term protective immunity. A comparison of RSV-immunized mice to mice vaccinated with a single dose of ∆F/TriAdj showed no difference in IgG1 and IgG2a production; however, local IgA secreting memory B cell development and B cell IgA production were significantly lower in RSV vaccinated mice than in ∆F/TriAdj-immunized mice. This indicates a potential reason as to why long-term immunity is not induced by RSV infection. The comparison also revealed that germinal center lymphocyte populations were higher in ∆F/TriAdj-vaccinated mice. Furthermore, ∆F/TriAdj induced higher gene expression of activation-induced cytidine deaminase (AID), as well as IL-6, IL-21, TGF-β cytokines, which are key players in IgA class switch recombination, ultimately leading to a sustained long-term memory response. - Highlights: •Immune responses to adjuvanted RSV F protein, ∆F/TriAdj, and RSV were compared. •∆F/TriAdj stimulates more local IgA production than RSV. •∆F/TriAdj induces more local IgA secreting memory B cells than RSV. •Germinal center lymphocyte populations are higher in ∆F/TriAdj-vaccinated mice. •∆F/TriAdj induces higher gene expression of AID, IL-6, IL-21, and TGF-β than RSV.

  4. A single intranasal immunization with a subunit vaccine formulation induces higher mucosal IgA production than live respiratory syncytial virus

    Energy Technology Data Exchange (ETDEWEB)

    Garg, Ravendra [VIDO-InterVac, University of Saskatchewan, Saskatoon, SK S7N 5E3 (Canada); Theaker, Michael [Microbiology & Immunology, University of Saskatchewan, Saskatoon, SK S7N 5E3 (Canada); Martinez, Elisa C. [VIDO-InterVac, University of Saskatchewan, Saskatoon, SK S7N 5E3 (Canada); Microbiology & Immunology, University of Saskatchewan, Saskatoon, Canada SK S7N 5E3 (Canada); Drunen Littel-van den Hurk, Sylvia van, E-mail: sylvia.vandenhurk@usask.ca [VIDO-InterVac, University of Saskatchewan, Saskatoon, SK S7N 5E3 (Canada); Microbiology & Immunology, University of Saskatchewan, Saskatoon, SK S7N 5E3 (Canada)

    2016-12-15

    Respiratory syncytial virus (RSV) causes serious respiratory illness in infants and elderly. RSV infection induces short-lived immunity, which leaves people prone to re-infection. In contrast, the RSV fusion (F) protein formulated with a novel adjuvant (∆F/TriAdj) elicits long term protective immunity. A comparison of RSV-immunized mice to mice vaccinated with a single dose of ∆F/TriAdj showed no difference in IgG1 and IgG2a production; however, local IgA secreting memory B cell development and B cell IgA production were significantly lower in RSV vaccinated mice than in ∆F/TriAdj-immunized mice. This indicates a potential reason as to why long-term immunity is not induced by RSV infection. The comparison also revealed that germinal center lymphocyte populations were higher in ∆F/TriAdj-vaccinated mice. Furthermore, ∆F/TriAdj induced higher gene expression of activation-induced cytidine deaminase (AID), as well as IL-6, IL-21, TGF-β cytokines, which are key players in IgA class switch recombination, ultimately leading to a sustained long-term memory response. - Highlights: •Immune responses to adjuvanted RSV F protein, ∆F/TriAdj, and RSV were compared. •∆F/TriAdj stimulates more local IgA production than RSV. •∆F/TriAdj induces more local IgA secreting memory B cells than RSV. •Germinal center lymphocyte populations are higher in ∆F/TriAdj-vaccinated mice. •∆F/TriAdj induces higher gene expression of AID, IL-6, IL-21, and TGF-β than RSV.

  5. Methylphenidate Actively Induces Emergence from General Anesthesia

    Science.gov (United States)

    Solt, Ken; Cotten, Joseph F.; Cimenser, Aylin; Wong, Kin F.K.; Chemali, Jessica J.; Brown, Emery N.

    2011-01-01

    Background Although accumulating evidence suggests that arousal pathways in the brain play important roles in emergence from general anesthesia, the roles of monoaminergic arousal circuits are unclear. In this study we tested the hypothesis that methylphenidate (an inhibitor of dopamine and norepinephrine transporters) induces emergence from isoflurane anesthesia. Methods Using adult rats we tested the effect of methylphenidate IV on time to emergence from isoflurane anesthesia. We then performed experiments to test separately for methylphenidate-induced changes in arousal and changes in minute ventilation. A dose-response study was performed to test for methylphenidate–induced restoration of righting during continuous isoflurane anesthesia. Surface electroencephalogram recordings were performed to observe neurophysiological changes. Plethysmography recordings and arterial blood gas analysis were performed to assess methylphenidate-induced changes in respiratory function. Droperidol IV was administered to test for inhibition of methylphenidate's actions. Results Methylphenidate decreased median time to emergence from 280 to 91 s. The median difference in time to emergence without compared to with methylphenidate was 200 [155, 331] s (median, [95% confidence interval]). During continuous inhalation of isoflurane, methylphenidate induced return of righting in a dose-dependent manner, induced a shift in electroencephalogram power from delta to theta, and induced an increase in minute ventilation. Administration of droperidol (0.5 mg/kg IV) prior to methylphenidate (5 mg/kg IV) largely inhibited methylphenidate-induced emergence behavior, electroencephalogram changes, and changes in minute ventilation. Conclusions Methylphenidate actively induces emergence from isoflurane anesthesia by increasing arousal and respiratory drive, possibly through activation of dopaminergic and adrenergic arousal circuits. Our findings suggest that methylphenidate may be clinically

  6. Ethanol-Induced Neurodegeneration and Glial Activation in the Developing Brain

    Directory of Open Access Journals (Sweden)

    Mariko Saito

    2016-08-01

    Full Text Available Ethanol induces neurodegeneration in the developing brain, which may partially explain the long-lasting adverse effects of prenatal ethanol exposure in fetal alcohol spectrum disorders (FASD. While animal models of FASD show that ethanol-induced neurodegeneration is associated with glial activation, the relationship between glial activation and neurodegeneration has not been clarified. This review focuses on the roles of activated microglia and astrocytes in neurodegeneration triggered by ethanol in rodents during the early postnatal period (equivalent to the third trimester of human pregnancy. Previous literature indicates that acute binge-like ethanol exposure in postnatal day 7 (P7 mice induces apoptotic neurodegeneration, transient activation of microglia resulting in phagocytosis of degenerating neurons, and a prolonged increase in glial fibrillary acidic protein-positive astrocytes. In our present study, systemic administration of a moderate dose of lipopolysaccharides, which causes glial activation, attenuates ethanol-induced neurodegeneration. These studies suggest that activation of microglia and astrocytes by acute ethanol in the neonatal brain may provide neuroprotection. However, repeated or chronic ethanol can induce significant proinflammatory glial reaction and neurotoxicity. Further studies are necessary to elucidate whether acute or sustained glial activation caused by ethanol exposure in the developing brain can affect long-lasting cellular and behavioral abnormalities observed in the adult brain.

  7. Targeting APOBEC3A to the viral nucleoprotein complex confers antiviral activity

    Directory of Open Access Journals (Sweden)

    Strebel Klaus

    2007-08-01

    Full Text Available Abstract Background APOBEC3 (A3 proteins constitute a family of cytidine deaminases that provide intracellular resistance to retrovirus replication and to transposition of endogenous retroelements. A3A has significant homology to the C-terminus of A3G but has only a single cytidine deaminase active site (CDA, unlike A3G, which has a second N-terminal CDA previously found to be important for Vif sensitivity and virus encapsidation. A3A is packaged into HIV-1 virions but, unlike A3G, does not have antiviral properties. Here, we investigated the reason for the lack of A3A antiviral activity. Results Sequence alignment of A3G and A3A revealed significant homology of A3A to the C-terminal region of A3G. However, while A3G co-purified with detergent-resistant viral nucleoprotein complexes (NPC, virus-associated A3A was highly detergent-sensitive leading us to speculate that the ability to assemble into NPC may be a property conveyed by the A3G N-terminus. To test this model, we constructed an A3G-3A chimeric protein, in which the N-terminal half of A3G was fused to A3A. Interestingly, the A3G-3A chimera was packaged into HIV-1 particles and, unlike A3A, associated with the viral NPC. Furthermore, the A3G-3A chimera displayed strong antiviral activity against HIV-1 and was sensitive to inhibition by HIV-1 Vif. Conclusion Our results suggest that the A3G N-terminal domain carries determinants important for targeting the protein to viral NPCs. Transfer of this domain to A3A results in A3A targeting to viral NPCs and confers antiviral activity.

  8. Histamine induces microglia activation and dopaminergic neuronal toxicity via H1 receptor activation.

    Science.gov (United States)

    Rocha, Sandra M; Saraiva, Tatiana; Cristóvão, Ana C; Ferreira, Raquel; Santos, Tiago; Esteves, Marta; Saraiva, Cláudia; Je, Goun; Cortes, Luísa; Valero, Jorge; Alves, Gilberto; Klibanov, Alexander; Kim, Yoon-Seong; Bernardino, Liliana

    2016-06-04

    Histamine is an amine widely known as a peripheral inflammatory mediator and as a neurotransmitter in the central nervous system. Recently, it has been suggested that histamine acts as an innate modulator of microglial activity. Herein, we aimed to disclose the role of histamine in microglial phagocytic activity and reactive oxygen species (ROS) production and to explore the consequences of histamine-induced neuroinflammation in dopaminergic (DA) neuronal survival. The effect of histamine on phagocytosis was assessed both in vitro by using a murine N9 microglial cell line and primary microglial cell cultures and in vivo. Cells were exposed to IgG-opsonized latex beads or phosphatidylserine (PS) liposomes to evaluate Fcγ or PS receptor-mediated microglial phagocytosis, respectively. ROS production and protein levels of NADPH oxidases and Rac1 were assessed as a measure of oxidative stress. DA neuronal survival was evaluated in vivo by counting the number of tyrosine hydroxylase-positive neurons in the substantia nigra (SN) of mice. We found that histamine triggers microglial phagocytosis via histamine receptor 1 (H1R) activation and ROS production via H1R and H4R activation. By using apocynin, a broad NADPH oxidase (Nox) inhibitor, and Nox1 knockout mice, we found that the Nox1 signaling pathway is involved in both phagocytosis and ROS production induced by histamine in vitro. Interestingly, both apocynin and annexin V (used as inhibitor of PS-induced phagocytosis) fully abolished the DA neurotoxicity induced by the injection of histamine in the SN of adult mice in vivo. Blockade of H1R protected against histamine-induced Nox1 expression and death of DA neurons in vivo. Overall, our results highlight the relevance of histamine in the modulation of microglial activity that ultimately may interfere with neuronal survival in the context of Parkinson's disease (PD) and, eventually, other neurodegenerative diseases which are accompanied by microglia-induced

  9. Inducible tertiary lymphoid structures, autoimmunity and exocrine dysfunction in a novel model of salivary gland inflammation in C57BL/6 mice§

    Science.gov (United States)

    Bombardieri, Michele; Barone, Francesca; Lucchesi, Davide; Nayar, Saba; van den Berg, Wim B; Proctor, Gordon; Buckley, Christopher D; Pitzalis, Costantino

    2012-01-01

    Salivary glands in patients with Sjögren’s syndrome (SS) develop ectopic lymphoid structures (ELS) characterized by B/T cell compartmentalization, the formation of high endothelial venules (HEV), follicular dendritic cell networks (FDCs), functional B cell activation with expression of activation-induced cytidine deaminase (AID) as well as local differentiation of autoreactive plasma cells. The mechanisms triggering ELS formation, autoimmunity and exocrine dysfunction in SS are largely unknown. Here we present a novel model of inducible ectopic lymphoid tissue formation, breach of humoral self-tolerance and salivary hypofunction following delivery of a replication-deficient adenovirus-5 (AdV5) in submandibular glands of C57BL/6 mice through retrograde excretory duct cannulation. In this model, inflammation rapidly and consistently evolves from diffuse infiltration towards the development of SS-like periductal lymphoid aggregates within 2 weeks from AdV delivery. These infiltrates progressively acquire ELS features and support functional GL7+/AID+ germinal centers. Formation of ELS is preceded by ectopic expression of lymphoid chemokines CXCL13, CCL19 and lymphotoxin-β and is associated with development of anti-nuclear antibodies in up to 75% of mice. Finally, reduction in salivary flow was observed over 3 weeks post AdV infection consistent with exocrine gland dysfunction as a consequence of the inflammatory response. This novel model has the potential to unravel the cellular and molecular mechanisms regulating ELS formation and their role in exocrine dysfunction and autoimmunity in SS. PMID:22942425

  10. Misconceptions about mirror-induced motor cortex activation.

    NARCIS (Netherlands)

    Praamstra, P.; Torney, L.; Rawle, C.J.; Miall, R.C.

    2011-01-01

    Observation of self-produced hand movements through a mirror, creating an illusion of the opposite hand moving, was recently reported to induce ipsilateral motor cortex activation, that is, motor cortex activation for the hand in rest. The reported work goes far beyond earlier work on motor cortex

  11. Gastroprotective activity of polysaccharide from Hericium erinaceus against ethanol-induced gastric mucosal lesion and pylorus ligation-induced gastric ulcer, and its antioxidant activities.

    Science.gov (United States)

    Wang, Xiao-Yin; Yin, Jun-Yi; Zhao, Ming-Ming; Liu, Shi-Yu; Nie, Shao-Ping; Xie, Ming-Yong

    2018-04-15

    The gastroprotective activity of Hericium erinaceus polysaccharide was investigated in rats. The antioxidant activities were also evaluated. Pre-treatment of polysaccharide could reduce ethanol-induced gastric mucosal lesion and pylorus ligation-induced gastric ulcer. The polysaccharide exhibited scavenging activities of 1, 1-diphenyl-2-picryl-hydrozyl and hydroxyl radicals, and ferrous ion-chelating ability. In the pylorus ligation-induced model, gastric secretions (volume of gastric juice, gastric acid, pepsin and mucus) of ulcer rats administrated with polysaccharide were regulated. Levels of tumor necrosis factor-α and interleukins-1β in serum, and myeloperoxidase activity of gastric tissue were reduced, while antioxidant status of gastric tissue was improved. Defensive factors (nitric oxide, prostaglandin E2, epidermal growth factor) in gastric tissue were increased. These results indicate that Hericium erinaceus polysaccharide possess gastroprotective activity, and the possible mechanisms are related to its regulations of gastric secretions, improvements of anti-inflammatory and antioxidant status, as well as increments of defensive factors releases. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. Activity deprivation induces neuronal cell death: mediation by tissue-type plasminogen activator.

    Directory of Open Access Journals (Sweden)

    Eldi Schonfeld-Dado

    Full Text Available Spontaneous activity is an essential attribute of neuronal networks and plays a critical role in their development and maintenance. Upon blockade of activity with tetrodotoxin (TTX, neurons degenerate slowly and die in a manner resembling neurodegenerative diseases-induced neuronal cell death. The molecular cascade leading to this type of slow cell death is not entirely clear. Primary post-natal cortical neurons were exposed to TTX for up to two weeks, followed by molecular, biochemical and immunefluorescence analysis. The expression of the neuronal marker, neuron specific enolase (NSE, was down-regulated, as expected, but surprisingly, there was a concomitant and striking elevation in expression of tissue-type plasminogen activator (tPA. Immunofluorescence analysis indicated that tPA was highly elevated inside affected neurons. Transfection of an endogenous tPA inhibitor, plasminogen activator inhibitor-1 (PAI-1, protected the TTX-exposed neurons from dying. These results indicate that tPA is a pivotal player in slowly progressing activity deprivation-induced neurodegeneration.

  13. NOX2-Induced Activation of Arginase and Diabetes-Induced Retinal Endothelial Cell Senescence

    Directory of Open Access Journals (Sweden)

    Modesto Rojas

    2017-06-01

    Full Text Available Increases in reactive oxygen species (ROS and decreases in nitric oxide (NO have been linked to vascular dysfunction during diabetic retinopathy (DR. Diabetes can reduce NO by increasing ROS and by increasing activity of arginase, which competes with nitric oxide synthase (NOS for their commons substrate l-arginine. Increased ROS and decreased NO can cause premature endothelial cell (EC senescence leading to defective vascular repair. We have previously demonstrated the involvement of NADPH oxidase 2 (NOX2-derived ROS, decreased NO and overactive arginase in DR. Here, we investigated their impact on diabetes-induced EC senescence. Studies using diabetic mice and retinal ECs treated with high glucose or H2O2 showed that increases in ROS formation, elevated arginase expression and activity, and decreased NO formation led to premature EC senescence. NOX2 blockade or arginase inhibition prevented these effects. EC senescence was also increased by inhibition of NOS activity and this was prevented by treatment with a NO donor. These results indicate that diabetes/high glucose-induced activation of arginase and decreases in NO bioavailability accelerate EC senescence. NOX2-generated ROS contribute importantly to this process. Blockade of NOX2 or arginase represents a strategy to prevent diabetes-induced premature EC senescence by preserving NO bioavailability.

  14. Sphingosine-1-phosphate mediates epidermal growth factor-induced muscle satellite cell activation

    Energy Technology Data Exchange (ETDEWEB)

    Nagata, Yosuke, E-mail: cynagata@mail.ecc.u-tokyo.ac.jp; Ohashi, Kazuya; Wada, Eiji; Yuasa, Yuki; Shiozuka, Masataka; Nonomura, Yoshiaki; Matsuda, Ryoichi

    2014-08-01

    Skeletal muscle can regenerate repeatedly due to the presence of resident stem cells, called satellite cells. Because satellite cells are usually quiescent, they must be activated before participating in muscle regeneration in response to stimuli such as injury, overloading, and stretch. Although satellite cell activation is a crucial step in muscle regeneration, little is known of the molecular mechanisms controlling this process. Recent work showed that the bioactive lipid sphingosine-1-phosphate (S1P) plays crucial roles in the activation, proliferation, and differentiation of muscle satellite cells. We investigated the role of growth factors in S1P-mediated satellite cell activation. We found that epidermal growth factor (EGF) in combination with insulin induced proliferation of quiescent undifferentiated mouse myoblast C2C12 cells, which are also known as reserve cells, in serum-free conditions. Sphingosine kinase activity increased when reserve cells were stimulated with EGF. Treatment of reserve cells with the D-erythro-N,N-dimethylsphingosine, Sphingosine Kinase Inhibitor, or siRNA duplexes specific for sphingosine kinase 1, suppressed EGF-induced C2C12 activation. We also present the evidence showing the S1P receptor S1P2 is involved in EGF-induced reserve cell activation. Moreover, we demonstrated a combination of insulin and EGF promoted activation of satellite cells on single myofibers in a manner dependent on SPHK and S1P2. Taken together, our observations show that EGF-induced satellite cell activation is mediated by S1P and its receptor. - Highlights: • EGF in combination with insulin induces proliferation of quiescent C2C12 cells. • Sphingosine kinase activity increases when reserve cells are stimulated with EGF. • EGF-induced activation of reserve cells is dependent on sphingosine kinase and ERK. • The S1P receptor S1P2 is involved in EGF-induced reserve cell activation. • EGF-induced reserve cell activation is mediated by S1P and its

  15. Sphingosine-1-phosphate mediates epidermal growth factor-induced muscle satellite cell activation

    International Nuclear Information System (INIS)

    Nagata, Yosuke; Ohashi, Kazuya; Wada, Eiji; Yuasa, Yuki; Shiozuka, Masataka; Nonomura, Yoshiaki; Matsuda, Ryoichi

    2014-01-01

    Skeletal muscle can regenerate repeatedly due to the presence of resident stem cells, called satellite cells. Because satellite cells are usually quiescent, they must be activated before participating in muscle regeneration in response to stimuli such as injury, overloading, and stretch. Although satellite cell activation is a crucial step in muscle regeneration, little is known of the molecular mechanisms controlling this process. Recent work showed that the bioactive lipid sphingosine-1-phosphate (S1P) plays crucial roles in the activation, proliferation, and differentiation of muscle satellite cells. We investigated the role of growth factors in S1P-mediated satellite cell activation. We found that epidermal growth factor (EGF) in combination with insulin induced proliferation of quiescent undifferentiated mouse myoblast C2C12 cells, which are also known as reserve cells, in serum-free conditions. Sphingosine kinase activity increased when reserve cells were stimulated with EGF. Treatment of reserve cells with the D-erythro-N,N-dimethylsphingosine, Sphingosine Kinase Inhibitor, or siRNA duplexes specific for sphingosine kinase 1, suppressed EGF-induced C2C12 activation. We also present the evidence showing the S1P receptor S1P2 is involved in EGF-induced reserve cell activation. Moreover, we demonstrated a combination of insulin and EGF promoted activation of satellite cells on single myofibers in a manner dependent on SPHK and S1P2. Taken together, our observations show that EGF-induced satellite cell activation is mediated by S1P and its receptor. - Highlights: • EGF in combination with insulin induces proliferation of quiescent C2C12 cells. • Sphingosine kinase activity increases when reserve cells are stimulated with EGF. • EGF-induced activation of reserve cells is dependent on sphingosine kinase and ERK. • The S1P receptor S1P2 is involved in EGF-induced reserve cell activation. • EGF-induced reserve cell activation is mediated by S1P and its

  16. Obesity-induced vascular inflammation involves elevated arginase activity.

    Science.gov (United States)

    Yao, Lin; Bhatta, Anil; Xu, Zhimin; Chen, Jijun; Toque, Haroldo A; Chen, Yongjun; Xu, Yimin; Bagi, Zsolt; Lucas, Rudolf; Huo, Yuqing; Caldwell, Ruth B; Caldwell, R William

    2017-11-01

    Obesity-induced vascular dysfunction involves pathological remodeling of the visceral adipose tissue (VAT) and increased inflammation. Our previous studies showed that arginase 1 (A1) in endothelial cells (ECs) is critically involved in obesity-induced vascular dysfunction. We tested the hypothesis that EC-A1 activity also drives obesity-related VAT remodeling and inflammation. Our studies utilized wild-type and EC-A1 knockout (KO) mice made obese by high-fat/high-sucrose (HFHS) diet. HFHS diet induced increases in body weight, fasting blood glucose, and VAT expansion. This was accompanied by increased arginase activity and A1 expression in vascular ECs and increased expression of tumor necrosis factor-α (TNF-α), monocyte chemoattractant protein-1 (MCP-1), interleukin-10 (IL-10), vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1) mRNA and protein in both VAT and ECs. HFHS also markedly increased circulating inflammatory monocytes and VAT infiltration by inflammatory macrophages, while reducing reparative macrophages. Additionally, adipocyte size and fibrosis increased and capillary density decreased in VAT. These effects of HFHS, except for weight gain and hyperglycemia, were prevented or reduced in mice lacking EC-A1 or treated with the arginase inhibitor 2-( S )-amino-6-boronohexanoic acid (ABH). In mouse aortic ECs, exposure to high glucose (25 mM) and Na palmitate (200 μM) reduced nitric oxide production and increased A1, TNF-α, VCAM-1, ICAM-1, and MCP-1 mRNA, and monocyte adhesion. Knockout of EC-A1 or ABH prevented these effects. HFHS diet-induced VAT inflammation is mediated by EC-A1 expression/activity. Limiting arginase activity is a possible therapeutic means of controlling obesity-induced vascular and VAT inflammation.

  17. Dihydrotestosterone Potentiates EGF-Induced ERK Activation by Inducing SRC in Fetal Lung Fibroblasts

    Science.gov (United States)

    Smith, Susan M.; Murray, Sandy; Pham, Lucia D.; Minoo, Parviz; Nielsen, Heber C.

    2014-01-01

    Lung maturation is regulated by interactions between mesenchymal and epithelial cells, and is delayed by androgens. Fibroblast–Type II cell communications are dependent on extracellular signal-regulated kinases (ERK) 1/2 activation by the ErbB receptor ligands epidermal growth factor (EGF), transforming growth factor (TGF)-α, and neuregulin (Nrg). In other tissues, dihydrotestosterone (DHT) has been shown to activate SRC by a novel nontranscriptional mechanism, which phosphorylates EGF receptors to potentiate EGF-induced ERK1/2 activation. This study sought to determine if DHT potentiates EGFR signaling by a nontranscriptional mechanism. Embryonic day (E)17 fetal lung cells were isolated from dams treated with or without DHT since E12. Cells were exposed to 30 ng/ml DHT for periods of 30 minutes to 3 days before being stimulated with 100 ng/ml EGF, TGF-α, or Nrg for up to 30 minutes. Lysates were immunoblotted for ErbB and SRC pathway signaling intermediates. DHT increased ERK1/2 activation by EGF, TGF-α, and Nrg in fibroblasts and Type II cells. Characterization in fibroblasts showed that potentiation of the EGF pathway was significant after 60 minutes of DHT exposure and persisted in the presence of the translational inhibitor cycloheximide. SRC and EGF receptor phosphorylation was increased by DHT, as was EGF-induced SHC1 phosphorylation and subsequent association with GRB2. Finally, SRC silencing, SRC inhibition with PP2, and overexpression of a dominant-negative SRC each prevented DHT from increasing EGF-induced ERK1/2 phosphorylation. These results suggest that DHT activates SRC to potentiate the signaling pathway leading from the EGF receptor to ERK activation in primary fetal lung fibroblasts. PMID:24484548

  18. Protease-activated receptor 1 and 2 contribute to angiotensin II-induced activation of adventitial fibroblasts from rat aorta

    Energy Technology Data Exchange (ETDEWEB)

    He, Rui-Qing; Tang, Xiao-Feng; Zhang, Bao-Li [State Key Laboratory of Medical Genetics, Shanghai Key Laboratory of Hypertension and Department of Hypertension, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine (China); Shanghai Institute of Hypertension, Shanghai (China); Li, Xiao-Dong [State Key Laboratory of Medical Genetics, Shanghai Key Laboratory of Hypertension and Department of Hypertension, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine (China); Laboratory of Vascular Biology, Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai (China); Shanghai Institute of Hypertension, Shanghai (China); Hong, Mo-Na [State Key Laboratory of Medical Genetics, Shanghai Key Laboratory of Hypertension and Department of Hypertension, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine (China); Shanghai Institute of Hypertension, Shanghai (China); Chen, Qi-Zhi [Shanghai Institute of Hypertension, Shanghai (China); Han, Wei-Qing, E-mail: whan020@gmail.com [State Key Laboratory of Medical Genetics, Shanghai Key Laboratory of Hypertension and Department of Hypertension, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine (China); Laboratory of Vascular Biology, Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai (China); Shanghai Institute of Hypertension, Shanghai (China); Gao, Ping-Jin, E-mail: gaopingjin@sibs.ac.cn [State Key Laboratory of Medical Genetics, Shanghai Key Laboratory of Hypertension and Department of Hypertension, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine (China); Laboratory of Vascular Biology, Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai (China); Shanghai Institute of Hypertension, Shanghai (China)

    2016-04-29

    Adventitial fibroblasts (AFs) can be activated by angiotensin II (Ang II) and exert pro-fibrotic and pro-inflammatory effects in vascular remodeling. Protease-activated receptor (PAR) 1 and 2 play a significant role in fibrogenic and inflammatory diseases. The present study hypothesized that PAR1 and PAR2 are involved in Ang II-induced AF activation and contribute to adventitial remodeling. We found that direct activation of PAR1 and PAR2 with PAR1-AP and PAR2-AP led to AF activation, including proliferation and differentiation of AFs, extracellular matrix synthesis, as well as production of pro-fibrotic cytokine TGF-β and pro-inflammatory cytokines IL-6 and MCP-1. Furthermore, PAR1 and PAR2 mediated Ang II-induced AF activation, since both PAR1 and PAR2 antagonists inhibited Ang II-induced proliferation, migration, differentiation, extracellular matrix synthesis and production of pro-fibrotic and pro-inflammatory cytokines in AFs. Finally, mechanistic study showed that Ang II, via Ang II type I receptor (AT1R), upregulated both PAR1 and PAR2 expression, and transactivated PAR1 and PAR2, as denoted by internalization of both proteins. In conclusion, our results suggest that PAR1 and PAR2 play a critical role in Ang II-induced AF activation, and this may contribute to adventitia-related pathological changes. - Highlights: • Direct activation of PAR1 and PAR2 led to adventitial fibroblast (AF) activation. • PAR1 and PAR2 antagonists attenuated Ang II-induced AF activation. • Ang II induced the upregulation and transactivation of PAR1/PAR2 in AFs.

  19. Protease-activated receptor 1 and 2 contribute to angiotensin II-induced activation of adventitial fibroblasts from rat aorta

    International Nuclear Information System (INIS)

    He, Rui-Qing; Tang, Xiao-Feng; Zhang, Bao-Li; Li, Xiao-Dong; Hong, Mo-Na; Chen, Qi-Zhi; Han, Wei-Qing; Gao, Ping-Jin

    2016-01-01

    Adventitial fibroblasts (AFs) can be activated by angiotensin II (Ang II) and exert pro-fibrotic and pro-inflammatory effects in vascular remodeling. Protease-activated receptor (PAR) 1 and 2 play a significant role in fibrogenic and inflammatory diseases. The present study hypothesized that PAR1 and PAR2 are involved in Ang II-induced AF activation and contribute to adventitial remodeling. We found that direct activation of PAR1 and PAR2 with PAR1-AP and PAR2-AP led to AF activation, including proliferation and differentiation of AFs, extracellular matrix synthesis, as well as production of pro-fibrotic cytokine TGF-β and pro-inflammatory cytokines IL-6 and MCP-1. Furthermore, PAR1 and PAR2 mediated Ang II-induced AF activation, since both PAR1 and PAR2 antagonists inhibited Ang II-induced proliferation, migration, differentiation, extracellular matrix synthesis and production of pro-fibrotic and pro-inflammatory cytokines in AFs. Finally, mechanistic study showed that Ang II, via Ang II type I receptor (AT1R), upregulated both PAR1 and PAR2 expression, and transactivated PAR1 and PAR2, as denoted by internalization of both proteins. In conclusion, our results suggest that PAR1 and PAR2 play a critical role in Ang II-induced AF activation, and this may contribute to adventitia-related pathological changes. - Highlights: • Direct activation of PAR1 and PAR2 led to adventitial fibroblast (AF) activation. • PAR1 and PAR2 antagonists attenuated Ang II-induced AF activation. • Ang II induced the upregulation and transactivation of PAR1/PAR2 in AFs.

  20. Acupuncture inhibits cue-induced heroin craving and brain activation.

    Science.gov (United States)

    Cai, Xinghui; Song, Xiaoge; Li, Chuanfu; Xu, Chunsheng; Li, Xiliang; Lu, Qi

    2012-11-25

    Previous research using functional MRI has shown that specific brain regions associated with drug dependence and cue-elicited heroin craving are activated by environmental cues. Craving is an important trigger of heroin relapse, and acupuncture may inhibit craving. In this study, we performed functional MRI in heroin addicts and control subjects. We compared differences in brain activation between the two groups during heroin cue exposure, heroin cue exposure plus acupuncture at the Zusanli point (ST36) without twirling of the needle, and heroin cue exposure plus acupuncture at the Zusanli point with twirling of the needle. Heroin cue exposure elicited significant activation in craving-related brain regions mainly in the frontal lobes and callosal gyri. Acupuncture without twirling did not significantly affect the range of brain activation induced by heroin cue exposure, but significantly changed the extent of the activation in the heroin addicts group. Acupuncture at the Zusanli point with twirling of the needle significantly decreased both the range and extent of activation induced by heroin cue exposure compared with heroin cue exposure plus acupuncture without twirling of the needle. These experimental findings indicate that presentation of heroin cues can induce activation in craving-related brain regions, which are involved in reward, learning and memory, cognition and emotion. Acupuncture at the Zusanli point can rapidly suppress the activation of specific brain regions related to craving, supporting its potential as an intervention for drug craving.

  1. Chronophin activation is necessary in Doxorubicin-induced actin cytoskeleton alteration.

    Science.gov (United States)

    Lee, Su Jin; Park, Jeen Woo; Kang, Beom Sik; Lee, Dong-Seok; Lee, Hyun-Shik; Choi, Sooyoung; Kwon, Oh-Shin

    2017-06-01

    Although doxorubicin (Dox)-induced oxidative stress is known to be associated with cytotoxicity, the precise mechanism remains unclear. Genotoxic stress not only generates free radicals, but also affects actin cytoskeleton stability. We showed that Dox-induced RhoA signaling stimulated actin cytoskeleton alterations, resulting in central stress fiber disruption at early time points and cell periphery cortical actin formation at a later stage, in HeLa cells. Interestingly, activation of a cofilin phosphatase, chronophin (CIN), was initially evoked by Dox-induced RhoA signaling, resulting in a rapid phosphorylated cofilin turnover leading to actin cytoskeleton remodeling. In addition, a novel interaction between CIN and 14-3-3ζ was detected in the absence of Dox treatment. We demonstrated that CIN activity is quite contrary to 14-3-3ζ binding, and the interaction leads to enhanced phosphorylated cofilin levels. Therefore, initial CIN activation regulation could be critical in Dox-induced actin cytoskeleton remodeling through RhoA/cofilin signaling. [BMB Reports 2017; 50(6): 335-340].

  2. HTLV-1 Tax-induced NFκB activation is independent of Lys-63-linked-type polyubiquitination

    International Nuclear Information System (INIS)

    Gohda, Jin; Irisawa, Masato; Tanaka, Yuetsu; Sato, Shintaro; Ohtani, Kiyoshi; Fujisawa, Jun-ichi; Inoue, Jun-ichiro

    2007-01-01

    Human T-cell leukemia virus type 1 (HTLV-1) Tax-induced activation of nuclear factor-κB (NFκB) is thought to play a critical role in T-cell transformation and onset of adult T-cell leukemia. However, the molecular mechanism of the Tax-induced NFκB activation remains unknown. One of the mitogen-activated protein kinase kinase kinses (MAP3Ks) members, TAK1, plays a critical role in cytokine-induced activation of NFκB, which involves lysine 63-linked (K63) polyubiquitination of NEMO, a noncatalytic subunit of the IκB kinase complex. Here we show that Tax induces K63 polyubiquitination of NEMO. However, TAK1 is dispensable for Tax-induced NFκB activation, and deubiquitination of the K63 polyubiquitin chain failed to block Tax-induced NFκB activation. In addition, silencing of other MAP3Ks, including MEKK1, MEKK3, NIK, and TPL-2, did not affect Tax-induced NFκB activation. These results strongly suggest that unlike cytokine signaling, Tax-induced NFκB activation does not involve K63 polyubiquitination-mediated MAP3K activation

  3. Fructokinase activity mediates dehydration-induced renal injury.

    Science.gov (United States)

    Roncal Jimenez, Carlos A; Ishimoto, Takuji; Lanaspa, Miguel A; Rivard, Christopher J; Nakagawa, Takahiko; Ejaz, A Ahsan; Cicerchi, Christina; Inaba, Shinichiro; Le, MyPhuong; Miyazaki, Makoto; Glaser, Jason; Correa-Rotter, Ricardo; González, Marvin A; Aragón, Aurora; Wesseling, Catharina; Sánchez-Lozada, Laura G; Johnson, Richard J

    2014-08-01

    The epidemic of chronic kidney disease in Nicaragua (Mesoamerican nephropathy) has been linked with recurrent dehydration. Here we tested whether recurrent dehydration may cause renal injury by activation of the polyol pathway, resulting in the generation of endogenous fructose in the kidney that might subsequently induce renal injury via metabolism by fructokinase. Wild-type and fructokinase-deficient mice were subjected to recurrent heat-induced dehydration. One group of each genotype was provided water throughout the day and the other group was hydrated at night, after the dehydration. Both groups received the same total hydration in 24 h. Wild-type mice that received delayed hydration developed renal injury, with elevated serum creatinine, increased urinary NGAL, proximal tubular injury, and renal inflammation and fibrosis. This was associated with activation of the polyol pathway, with increased renal cortical sorbitol and fructose levels. Fructokinase-knockout mice with delayed hydration were protected from renal injury. Thus, recurrent dehydration can induce renal injury via a fructokinase-dependent mechanism, likely from the generation of endogenous fructose via the polyol pathway. Access to sufficient water during the dehydration period can protect mice from developing renal injury. These studies provide a potential mechanism for Mesoamerican nephropathy.

  4. Neuropharmacology of light-induced locomotor activation.

    Science.gov (United States)

    Amato, Davide; Pum, Martin E; Groos, Dominik; Lauber, Andrea C; Huston, Joseph P; Carey, Robert J; de Souza Silva, Maria A; Müller, Christian P

    2015-08-01

    Presentation of non-aversive light stimuli for several seconds was found to reliably induce locomotor activation and exploratory-like activity. Light-induced locomotor activity (LIA) can be considered a convenient simple model to study sensory-motor activation. LIA was previously shown to coincide with serotonergic and dopaminergic activation in specific cortical areas in freely moving and anesthetized animals. In the present study we explore the neuropharmacology of LIA using a receptor antagonist/agonist approach in rats. The non-selective 5-HT2-receptor antagonist ritanserin (1.5-6 mg/kg, i.p.) dose-dependently reduced LIA. Selective antagonism of either the 5-HT2A-receptor by MDL 11,939 (0.1-0.4 mg/kg, i.p.), or the 5-HT2C-receptor by SDZ SER 082 (0.125-0.5 mg/kg, i.p.), alone or in combination, had no significant influence on LIA. Also the selective 5-HT1A-receptor antagonist, WAY 100635 (0.4 mg/kg, i.p.) did not affect LIA. Neither did the preferential dopamine D2-receptor antagonist, haloperidol (0.025-0.1 mg/kg, i.p.) nor the D2/D3-receptor agonist, quinpirole (0.025-0.5 mg/kg, i.p.) affect the expression of LIA. However, blocking the glutamatergic NMDA-receptor with phencyclidine (PCP, 1.5-6 mg/kg, i.p.) dose-dependently reduced LIA. This effect was also observed with ketamine (10 mg/kg, i.p.). These findings suggest that serotonin and dopamine receptors abundantly expressed in the cortex do not mediate light-stimulus triggered locomotor activity. PCP and ketamine effects, however, suggest an important role of NMDA receptors in LIA. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Autophagy activation, not peroxisome proliferator-activated receptor γ coactivator 1α, may mediate exercise-induced improvements in glucose handling during diet-induced obesity.

    Science.gov (United States)

    Rosa-Caldwell, Megan E; Brown, Jacob L; Lee, David E; Blackwell, Thomas A; Turner, Kyle W; Brown, Lemuel A; Perry, Richard A; Haynie, Wesley S; Washington, Tyrone A; Greene, Nicholas P

    2017-09-01

    What is the central question of this study? What are the individual and combined effects of muscle-specific peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) overexpression and physical activity during high-fat feeding on glucose and exercise tolerance? What is the main finding and its importance? Our main finding is that muscle-specific PGC-1α overexpression provides no protection against lipid-overload pathologies nor does it enhance exercise adaptations. Instead, physical activity, regardless of PGC-1α content, protects against high-fat diet-induced detriments. Activation of muscle autophagy was correlated with exercise protection, suggesting that autophagy might be a mediating factor for exercise-induced protection from lipid overload. The prevalence of glucose intolerance is alarmingly high. Efforts to promote mitochondrial biogenesis through peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) to mitigate glucose intolerance have been controversial. However, physical activity remains a primary means to alleviate the condition. The aim of this study was to determine the combined effects of muscle-specific overexpression of PGC-1α and physical activity on glucose handling during diet-induced obesity. Wild-type (WT, ∼20) and PGC-1α muscle transgenic (MCK-PGC-1α, ∼20) mice were given a Western diet (WD) at 8 weeks age and allowed to consume food ab libitum throughout the study. At 12 weeks of age, all animals were divided into sedentary (SED) or voluntary wheel running (VWR) interventions. At 7, 11 and 15 weeks of age, animals underwent glucose tolerance tests (GTT) and graded exercise tests (GXT). At 16 weeks of age, tissues were collected. At 11 weeks, the MCK-PGC-1α animals had 50% greater glucose tolerance integrated area under the curve compared with WT. However, at 15 weeks, SED animals also had greater GTT integrated area under the curve compared with VWR, regardless of genotype; furthermore, SED

  6. Activation of peroxisome proliferator-activated receptor-γ (PPARγ) induces cell death through MAPK-dependent mechanism in osteoblastic cells

    International Nuclear Information System (INIS)

    Kim, Sung Hun; Yoo, Chong Il; Kim, Hui Taek; Park, Ji Yeon; Kwon, Chae Hwa; Keun Kim, Yong

    2006-01-01

    The present study was undertaken to determine the role of the mitogen-activated protein kinase (MAPK) subfamilies in cell death induced by PPARγ agonists in osteoblastic cells. Ciglitazone and troglitazone, PPARγ agonists, resulted in a concentration- and time-dependent cell death, which was largely attributed to apoptosis. But a PPARα agonist ciprofibrate did not affect the cell death. Ciglitazone caused reactive oxygen species (ROS) generation and ciglitazone-induced cell death was prevented by antioxidants, suggesting an important role of ROS generation in the ciglitazone-induced cell death. ROS generation and cell death induced by ciglitazone were inhibited by the PPARγ antagonist GW9662. Ciglitazone treatment caused activation of extracellular signal-regulated kinase (ERK) and p38. Activation of ERK was dependent on epidermal growth factor receptor (EGFR) and that of p38 was independent. Ciglitazone-induced cell death was significantly prevented by PD98059, an inhibitor of ERK upstream kinase MEK1/2, and SB203580, a p38 inhibitor. Ciglitazone treatment increased Bax expression and caused a loss of mitochondrial membrane potential, and its effect was prevented by N-acetylcysteine, PD98059, and SB203580. Ciglitazone induced caspase activation, which was prevented by PD98059 and SB203580. The general caspase inhibitor z-DEVD-FMK and the specific inhibitor of caspases-3 DEVD-CHO exerted the protective effect against the ciglitazone-induced cell death. The EGFR inhibitors AG1478 and suramin protected against the ciglitazone-induced cell death. Taken together, these findings suggest that the MAPK signaling pathways play an active role in mediating the ciglitazone-induced cell death of osteoblasts and function upstream of a mitochondria-dependent mechanism. These data may provide a novel insight into potential therapeutic strategies for treatment of osteoporosis

  7. Kupffer cells activation promoted binge drinking-induced fatty liver by activating lipolysis in white adipose tissues.

    Science.gov (United States)

    Zhao, Yu-Ying; Yang, Rui; Xiao, Mo; Guan, Min-Jie; Zhao, Ning; Zeng, Tao

    2017-09-01

    Kupffer cells (KCs) have been suggested to play critical roles in chronic ethanol induced early liver injury, but the role of KCs in binge drinking-induced hepatic steatosis remains unclear. This study was designed to investigate the roles of KCs inhibitor (GdCl 3 ) and TNF-α antagonist (etanercept) on binge drinking-induced liver steatosis and to explore the underlying mechanisms. C57BL/6 mice were exposed to three doses of ethanol (6g/kg body weight) to mimic binge drinking-induced fatty liver. The results showed that both GdCl 3 and etanercept partially but significantly alleviated binge drinking-induced increase of hepatic triglyceride (TG) level, and reduced fat droplets accumulation in mice liver. GdCl 3 but not etanercept significantly blocked binge drinking-induced activation of KCs. However, neither GdCl 3 nor etanercept could affect binge drinking-induced decrease of PPAR-α, ACOX, FAS, ACC and SCD protein levels, or increase of the LC3 II/LC3 I ratio and p62 protein level. Interestingly, both GdCl 3 and etanercept significantly suppressed binge drinking-induced phosphorylation of HSL in epididymal adipose tissues. Results of in vitro studies with cultured epididymal adipose tissues showed that TNF-α could increase the phosphorylation of HSL in adipose tissues and upgrade the secretion of free fatty acid (FFA) in the culture medium. Taken together, KCs inhibitor and TNF-α antagonist could partially attenuate binge drinking-induced liver steatosis, which might be attributed to the suppression of mobilization of white adipose tissues. These results suggest that KCs activation may promote binge drinking-induced fatty liver by TNF-α mediated activation of lipolysis in white adipose tissues. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Human retinal pigment epithelial cell-induced apoptosis in activated T cells

    DEFF Research Database (Denmark)

    Jørgensen, A; Wiencke, A K; la Cour, M

    1998-01-01

    human retinal pigment epithelial (RPE) cells can induce apoptosis in activated T cells. METHODS: Fas ligand (FasL) expression was detected by flow cytometry and immunohistochemistry. Cultured RPE cells were cocultured with T-cell lines and peripheral blood lymphocytes for 6 hours to 2 days. Induction...... of apoptosis was detected by 7-amino-actinomycin D and annexin V staining. RESULTS: Retinal pigment epithelial cells expressed FasL and induced apoptosis in activated Fas+ T cells. Blocking of Fas-FasL interaction with antibody strongly inhibited RPE-mediated T-cell apoptosis. Retinal pigment epithelial cells...... induced apoptosis in several activated T-cell populations and T-cell lines, including T-cell antigen receptor (TCR)-CD3-negative T-cell lines. In contrast, RPE cells induced little or no apoptosis in resting peripheral T cells. Major histocompatibility complex (MHC) class II monoclonal antibodies, which...

  9. Nrf2 activation prevents cadmium-induced acute liver injury

    International Nuclear Information System (INIS)

    Wu, Kai C.; Liu, Jie J.; Klaassen, Curtis D.

    2012-01-01

    Oxidative stress plays an important role in cadmium-induced liver injury. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor that up-regulates cytoprotective genes in response to oxidative stress. To investigate the role of Nrf2 in cadmium-induced hepatotoxicity, Nrf2-null mice, wild-type mice, kelch-like ECH-associated protein 1-knockdown (Keap1-KD) mice with enhanced Nrf2, and Keap1-hepatocyte knockout (Keap1-HKO) mice with maximum Nrf2 activation were treated with cadmium chloride (3.5 mg Cd/kg, i.p.). Blood and liver samples were collected 8 h thereafter. Cadmium increased serum alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) activities, and caused extensive hepatic hemorrhage and necrosis in the Nrf2-null mice. In contrast, Nrf2-enhanced mice had lower serum ALT and LDH activities and less morphological alternations in the livers than wild-type mice. H 2 DCFDA (2′,7′-dichlorodihydrofluoresein diacetate) staining of primary hepatocytes isolated from the four genotypes of mice indicated that oxidative stress was higher in Nrf2-null cells, and lower in Nrf2-enhanced cells than in wild-type cells. To further investigate the mechanism of the protective effect of Nrf2, mRNA of metallothionein (MT) and other cytoprotective genes were determined. Cadmium markedly induced MT-1 and MT-2 in livers of all four genotypes of mice. In contrast, genes involved in glutathione synthesis and reducing reactive oxygen species, including glutamate-cysteine ligase (Gclc), glutathione peroxidase-2 (Gpx2), and sulfiredoxin-1 (Srxn-1) were only induced in Nrf2-enhanced mice, but not in Nrf2-null mice. In conclusion, the present study shows that Nrf2 activation prevents cadmium-induced oxidative stress and liver injury through induction of genes involved in antioxidant defense rather than genes that scavenge Cd. -- Highlights: ► Cadmium caused extensive hepatic hemorrhage and necrosis in Nrf2-null mice. ► Keap1-KD and Keap1-HKO mice were

  10. Nrf2 activation prevents cadmium-induced acute liver injury

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Kai C. [Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Liu, Jie J. [Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS (United States); Klaassen, Curtis D., E-mail: cklaasse@kumc.edu [Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS (United States)

    2012-08-15

    Oxidative stress plays an important role in cadmium-induced liver injury. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor that up-regulates cytoprotective genes in response to oxidative stress. To investigate the role of Nrf2 in cadmium-induced hepatotoxicity, Nrf2-null mice, wild-type mice, kelch-like ECH-associated protein 1-knockdown (Keap1-KD) mice with enhanced Nrf2, and Keap1-hepatocyte knockout (Keap1-HKO) mice with maximum Nrf2 activation were treated with cadmium chloride (3.5 mg Cd/kg, i.p.). Blood and liver samples were collected 8 h thereafter. Cadmium increased serum alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) activities, and caused extensive hepatic hemorrhage and necrosis in the Nrf2-null mice. In contrast, Nrf2-enhanced mice had lower serum ALT and LDH activities and less morphological alternations in the livers than wild-type mice. H{sub 2}DCFDA (2′,7′-dichlorodihydrofluoresein diacetate) staining of primary hepatocytes isolated from the four genotypes of mice indicated that oxidative stress was higher in Nrf2-null cells, and lower in Nrf2-enhanced cells than in wild-type cells. To further investigate the mechanism of the protective effect of Nrf2, mRNA of metallothionein (MT) and other cytoprotective genes were determined. Cadmium markedly induced MT-1 and MT-2 in livers of all four genotypes of mice. In contrast, genes involved in glutathione synthesis and reducing reactive oxygen species, including glutamate-cysteine ligase (Gclc), glutathione peroxidase-2 (Gpx2), and sulfiredoxin-1 (Srxn-1) were only induced in Nrf2-enhanced mice, but not in Nrf2-null mice. In conclusion, the present study shows that Nrf2 activation prevents cadmium-induced oxidative stress and liver injury through induction of genes involved in antioxidant defense rather than genes that scavenge Cd. -- Highlights: ► Cadmium caused extensive hepatic hemorrhage and necrosis in Nrf2-null mice. ► Keap1-KD and Keap1-HKO mice

  11. Epigenetic regulation of photoperiodic flowering

    OpenAIRE

    Takeno, Kiyotoshi

    2010-01-01

    The cytidine analogue 5-azacytidine, which causes DNA demethylation, induced flowering in the non-vernalization-requiring plants Perilla frutescens var. crispa, Silene armeria and Pharbitis nil (synonym Ipomoea nil) under non-inductive photoperiodic conditions, suggesting that the expression of photoperiodic flowering-related genes is regulated epigenetically by DNA methylation. The flowering state induced by DNA demethylation was not heritable. Changes in the genome-wide methylation state we...

  12. Laser Induced Selective Activation For Subsequent Autocatalytic Electroless Plating

    DEFF Research Database (Denmark)

    Zhang, Yang

    . The third hypothesis is that the activation and rinsing process can be described by diffusion. This hypothesis is proved using Fick’s diffusion laws combined with the short-time-plating experiment. The influence of laser parameters on the surface structure is investigated for Nd:YAG, UV, and fiber lasers......The subject of this PhD thesis is “Laser induced selective activation for subsequent autocatalytic electroless plating.” The objective of the project is to investigate the process chains for micro structuring of polymer surfaces for selective micro metallization. Laser induced selective activation...... (LISA) is introduced and studied as a new technique for producing 3D moulded interconnect devices (3D-MIDs). This technique enables the metallization of polymer surface modified by laser and subsequently activated by a PdCl2/SnCl2 system. Various technologies exist on an industrial level...

  13. Kefiran suppresses antigen-induced mast cell activation.

    Science.gov (United States)

    Furuno, Tadahide; Nakanishi, Mamoru

    2012-01-01

    Kefir is a traditional fermented milk beverage produced by kefir grains in the Caucasian countries. Kefiran produced by Lactobacillus kefiranofaciens in kefir grains is an exopolysaccharide having a repeating structure with glucose and galactose residues in the chain sequence and has been suggested to exert many health-promoting effects such as immunomodulatory, hypotensive, hypocholesterolemic activities. Here we investigated the effects of kefiran on mast cell activation induced by antigen. Pretreatment with kefiran significantly inhibited antigen-induced Ca(2+) mobilization, degranulation, and tumor necrosis factor-α production in bone marrow-derived mast cells (BMMCs) in a dose-dependent manner. The phosphorylation of Akt, glycogen synthase kinase 3β, and extracellular signal-regulated kinases (ERKs) after antigen stimulation was also suppressed by pretreatment of BMMCs with kefiran. These findings indicate that kefiran suppresses mast cell degranulation and cytokine production by inhibiting the Akt and ERKs pathways, suggesting an anti-inflammatory effect for kefiran.

  14. Minocycline attenuates sevoflurane-induced cell injury via activation of Nrf2

    Science.gov (United States)

    Tian, Yue; Wu, Xiuying; Guo, Shanbin; Ma, Ling; Huang, Wei; Zhao, Xiaochun

    2017-01-01

    Minocycline has been demonstrated to exert neuroprotective effects in various experimental models. In the present study, we investigated the mechanisms underlying the protective effects of minocycline on cell injury induced by the inhalation of the anesthetic, sevoflurane. In our in vivo experiments using rats, minocycline attenuated sevoflurane-induced neuronal degeneration and apoptosis in the rat hippocampus, and this effect was associated with the minocycline-mediated suppression of oxidative stress in the hippocampus. In in vitro experiments, minocycline inhibited sevoflurane-induced apoptosis and the production of reactive oxygen species (ROS) in H4 human neuroglioma cells. In addition, minocycline suppressed the sevoflurane-induced upregulation of interleukin (IL)-6 and the activation of the nuclear factor-κB (NF-κB) signaling pathway in H4 cells. Furthermore, we found that nuclear factor E2-related factor 2 (Nrf2), an activator of the stress response, was upregulated and activated upon sevoflurane treatment both in the rat hippocampus and in H4 cells. In addition, minocycline further augmented the upregulation and activation of Nrf2 when used in conjunction with sevoflurane. Moreover, the knockdown of Nrf2 in H4 cells by small interfering RNA (siRNA) diminished the cytoprotective effect of minocycline, and attenuated the inhibitory effect of minocycline on ROS production, IL-6 upregulation and the activation of the NF-κB signaling pathway. On the whole, our findings indicate that minocycline may exert protective effects against sevoflurane-induced cell injury via the Nrf2-modulated antioxidant response and the inhibition of the activation of the NF-κB signaling pathway. PMID:28260081

  15. mTOR inhibition sensitizes ONC201-induced anti-colorectal cancer cell activity.

    Science.gov (United States)

    Jin, Zhe-Zhu; Wang, Wei; Fang, Di-Long; Jin, Yong-Jun

    2016-09-30

    We here tested the anti-colorectal cancer (CRC) activity by a first-in-class small molecule TRAIL inducer ONC201. The potential effect of mTOR on ONC201's actions was also examined. ONC201 induced moderate cytotoxicity against CRC cell lines (HT-29, HCT-116 and DLD-1) and primary human CRC cells. Significantly, AZD-8055, a mTOR kinase inhibitor, sensitized ONC201-induced cytotoxicity in CRC cells. Meanwhile, ONC201-induced TRAIL/death receptor-5 (DR-5) expression, caspase-8 activation and CRC cell apoptosis were also potentiated with AZD-8055 co-treatment. Reversely, TRAIL sequestering antibody RIK-2 or the caspase-8 specific inhibitor z-IETD-fmk attenuated AZD-8055 plus ONC201-induced CRC cell death. Further, mTOR kinase-dead mutation (Asp-2338-Ala) or shRNA knockdown significantly sensitized ONC201's activity in CRC cells, leading to profound cell death and apoptosis. On the other hand, expression of a constitutively-active S6K1 (T389E) attenuated ONC201-induced CRC cell apoptosis. For the mechanism study, we showed that ONC201 blocked Akt, but only slightly inhibited mTOR in CRC cells. Co-treatment with AZD-8055 also concurrently blocked mTOR activation. These results suggest that mTOR could be a primary resistance factor of ONC201 in CRC cells. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Effects of Active Mastication on Chronic Stress-Induced Bone Loss in Mice.

    Science.gov (United States)

    Azuma, Kagaku; Furuzawa, Manabu; Fujiwara, Shu; Yamada, Kumiko; Kubo, Kin-ya

    2015-01-01

    Chronic psychologic stress increases corticosterone levels, which decreases bone density. Active mastication or chewing attenuates stress-induced increases in corticosterone. We evaluated whether active mastication attenuates chronic stress-induced bone loss in mice. Male C57BL/6 (B6) mice were randomly divided into control, stress, and stress/chewing groups. Stress was induced by placing mice in a ventilated restraint tube (60 min, 2x/day, 4 weeks). The stress/chewing group was given a wooden stick to chew during the experimental period. Quantitative micro-computed tomography, histologic analysis, and biochemical markers were used to evaluate the bone response. The stress/chewing group exhibited significantly attenuated stress-induced increases in serum corticosterone levels, suppressed bone formation, enhanced bone resorption, and decreased trabecular bone mass in the vertebrae and distal femurs, compared with mice in the stress group. Active mastication during exposure to chronic stress alleviated chronic stress-induced bone density loss in B6 mice. Active mastication during chronic psychologic stress may thus be an effective strategy to prevent and/or treat chronic stress-related osteopenia.

  17. Clinical significance of plasminogen activator inhibitor activity in patients with exercise-induced ischemia

    International Nuclear Information System (INIS)

    Sakata, K.; Kurata, C.; Taguchi, T.; Suzuki, S.; Kobayashi, A.; Yamazaki, N.; Rydzewski, A.; Takada, Y.; Takada, A.

    1990-01-01

    To assess the fibrinolytic system in patients with exercise-induced ischemia and its relation to ischemia and severity of coronary artery disease (CAD), 47 patients with CAD confirmed by results of coronary angiography underwent symptom-limited multistage exercise thallium-201 emission computed tomography. All patients with CAD had exercise-induced ischemia as assessed from thallium-201 images. Pre- and peak exercise blood samples from each patient and preexercise blood samples from control subjects were assayed for several fibrinolytic components and were also assayed for plasma adrenaline. The extent of ischemia was defined as delta visual uptake score (total visual uptake score in delayed images minus total visual uptake score in initial images) and the severity of CAD as the number of diseased vessels. In the basal condition, plasminogen activator inhibitor (PAI) activity was significantly higher in patients with exercise-induced ischemia as compared to control subjects (p less than 0.01), although there were no significant differences in other fibrinolytic variables between the two groups. Moreover, PAI activity in the basal condition displayed a significantly positive correlation with the extent of ischemia (r = 0.47, p less than 0.01). Patients with exercise-induced ischemia were divided into two groups (24 with single-vessel disease and 23 with multivessel disease). There were no significant differences in coronary risk factors, hemodynamics, or plasma adrenaline levels during exercise between single-vessel and multivessel disease except that delta visual uptake score was significantly higher in multivessel disease (p less than 0.01)

  18. Resting-state brain activity in the motor cortex reflects task-induced activity: A multi-voxel pattern analysis.

    Science.gov (United States)

    Kusano, Toshiki; Kurashige, Hiroki; Nambu, Isao; Moriguchi, Yoshiya; Hanakawa, Takashi; Wada, Yasuhiro; Osu, Rieko

    2015-08-01

    It has been suggested that resting-state brain activity reflects task-induced brain activity patterns. In this study, we examined whether neural representations of specific movements can be observed in the resting-state brain activity patterns of motor areas. First, we defined two regions of interest (ROIs) to examine brain activity associated with two different behavioral tasks. Using multi-voxel pattern analysis with regularized logistic regression, we designed a decoder to detect voxel-level neural representations corresponding to the tasks in each ROI. Next, we applied the decoder to resting-state brain activity. We found that the decoder discriminated resting-state neural activity with accuracy comparable to that associated with task-induced neural activity. The distribution of learned weighted parameters for each ROI was similar for resting-state and task-induced activities. Large weighted parameters were mainly located on conjunctive areas. Moreover, the accuracy of detection was higher than that for a decoder whose weights were randomly shuffled, indicating that the resting-state brain activity includes multi-voxel patterns similar to the neural representation for the tasks. Therefore, these results suggest that the neural representation of resting-state brain activity is more finely organized and more complex than conventionally considered.

  19. Arsenic-induced alteration in intracellular calcium homeostasis induces head kidney macrophage apoptosis involving the activation of calpain-2 and ERK in Clarias batrachus

    International Nuclear Information System (INIS)

    Banerjee, Chaitali; Goswami, Ramansu; Datta, Soma; Rajagopal, R.; Mazumder, Shibnath

    2011-01-01

    We had earlier shown that exposure to arsenic (0.50 μM) caused caspase-3 mediated head kidney macrophage (HKM) apoptosis involving the p38-JNK pathway in Clarias batrachus. Here we examined the roles of calcium (Ca 2+ ) and extra-cellular signal-regulated protein kinase (ERK), the other member of MAPK-pathway on arsenic-induced HKM apoptosis. Arsenic-induced HKM apoptosis involved increased expression of ERK and calpain-2. Nifedipine, verapamil and EGTA pre-treatment inhibited the activation of calpain-2, ERK and reduced arsenic-induced HKM apoptosis as evidenced from reduced caspase-3 activity, Annexin V-FITC-propidium iodide and Hoechst 33342 staining. Pre-incubation with ERK inhibitor U 0126 inhibited the activation of calpain-2 and interfered with arsenic-induced HKM apoptosis. Additionally, pre-incubation with calpain-2 inhibitor also interfered with the activation of ERK and inhibited arsenic-induced HKM apoptosis. The NADPH oxidase inhibitor apocynin and diphenyleneiodonium chloride also inhibited ERK activation indicating activation of ERK in arsenic-exposed HKM also depends on signals from NADPH oxidase pathway. Our study demonstrates the critical role of Ca 2+ homeostasis on arsenic-induced HKM apoptosis. We suggest that arsenic-induced alteration in intracellular Ca 2+ levels initiates pro-apoptotic ERK and calpain-2; the two pathways influence each other positively and induce caspase-3 mediated HKM apoptosis. Besides, our study also indicates the role of ROS in the activation of ERK pathway in arsenic-induced HKM apoptosis in C. batrachus. - Highlights: → Altered Ca 2+ homeostasis leads to arsenic-induced HKM apoptosis. → Calpain-2 plays a critical role in the process. → ERK is pro-apoptotic in arsenic-induced HKM apoptosis. → Arsenic-induced HKM apoptosis involves cross talk between calpain-2 and ERK.

  20. Activation of PPARγ is not involved in butyrate-induced epithelial cell differentiation

    International Nuclear Information System (INIS)

    Ulrich, S.; Waechtershaeuser, A.; Loitsch, S.; Knethen, A. von; Bruene, B.; Stein, J.

    2005-01-01

    Histone deacetylase-inhibitors affect growth and differentiation of intestinal epithelial cells by inducing expression of several transcription factors, e.g. Peroxisome proliferator-activated receptor γ (PPARγ) or vitamin D receptor (VDR). While activation of VDR by butyrate mainly seems to be responsible for cellular differentiation, the activation of PPARγ in intestinal cells remains to be elucidated. The aim of this study was to determine the role of PPARγ in butyrate-induced cell growth inhibition and differentiation induction in Caco-2 cells. Treatment with PPARγ ligands ciglitazone and BADGE (bisphenol A diglycidyl) enhanced butyrate-induced cell growth inhibition in a dose- and time-dependent manner, whereas cell differentiation was unaffected after treatment with PPARγ ligands rosiglitazone and MCC-555. Experiments were further performed in dominant-negative PPARγ mutant cells leading to an increase in cell growth whereas butyrate-induced cell differentiation was again unaffected. The present study clearly demonstrated that PPARγ is involved in butyrate-induced inhibition of cell growth, but seems not to play an essential role in butyrate-induced cell differentiation

  1. Regulation of radiation-induced protein kinase Cδ activation in radiation-induced apoptosis differs between radiosensitive and radioresistant mouse thymic lymphoma cell lines

    International Nuclear Information System (INIS)

    Nakajima, Tetsuo; Yukawa, Osami; Tsuji, Hideo; Ohyama, Harumi; Wang, Bing; Tatsumi, Kouichi; Hayata, Isamu; Hama-Inaba, Hiroko

    2006-01-01

    Protein kinase Cδ (PKCδ) has an important role in radiation-induced apoptosis. The expression and function of PKCδ in radiation-induced apoptosis were assessed in a radiation-sensitive mouse thymic lymphoma cell line, 3SBH5, and its radioresistant variant, XR223. Rottlerin, a PKCδ-specific inhibitor, completely abolished radiation-induced apoptosis in 3SBH5. Radiation-induced PKCδ activation correlated with the degradation of PKCδ, indicating that PKCδ activation through degradation is involved in radiation-induced apoptosis in radiosensitive 3SBH5. In radioresistant XR223, radiation-induced PKCδ activation was lower than that in radiosensitive 3SBH5. Cytosol PKCδ levels in 3SBH5 decreased markedly after irradiation, while those in XR223 did not. There was no apparent change after irradiation in the membrane fractions of either cell type. In addition, basal cytosol PKCδ levels in XR223 were higher than those in 3SBH5. These results suggest that the radioresistance in XR223 to radiation-induced apoptosis is due to a difference in the regulation of radiation-induced PKCδ activation compared to that of 3SBH5. On the other hand, Atm -/- mouse thymic lymphoma cells were more radioresistant to radiation-induced apoptosis than wild-type mouse thymic lymphoma cells. Irradiated wild-type cells, but not Atm -/- cells, had decreased PKCδ levels, indicating that the Atm protein is involved in radiation-induced apoptosis through the induction of PKCδ degradation. The decreased Atm protein levels induced by treatment with Atm small interfering RNA had no effect on radiation-induced apoptosis in 3SBH5 cells. These results suggest that the regulation of radiation-induced PKCδ activation, which is distinct from the Atm-mediated cascade, determines radiation sensitivity in radiosensitive 3SBH5 cells

  2. Characteristics of induced activity from medical linear accelerators

    International Nuclear Information System (INIS)

    Wang Yizhen; Evans, Michael D.C.; Podgorsak, Ervin B.

    2005-01-01

    A study of the induced activity in a medical linear accelerator (linac) room was carried out on several linac installations. Higher beam energy, higher dose rate, and larger field size generally result in higher activation levels at a given point of interest, while the use of multileaf collimators (MLC) can also increase the activation level at the isocenter. Both theoretical and experimental studies reveal that the activation level in the morning before any clinical work increases from Monday to Saturday and then decreases during the weekend. This weekly activation picture keeps stable from one week to another during standard clinical operation of the linac. An effective half-life for a given point in the treatment room can be determined from the measured or calculated activity decay curves. The effective half-life for points inside the treatment field is longer than that for points outside of the field in the patient plane, while a larger field and longer irradiation time can also make the effective half-life longer. The activation level reaches its practical saturation value after a 30 min continuous irradiation, corresponding to 12 000 MU at a 'dose rate' of 400 MU/min. A 'dose' of 300 MU was given 20 times in 15 min intervals to determine the trends in the activation level in a typical clinical mode. As well, a long-term (85 h over a long weekend) decay curve was measured to evaluate the long-term decay of room activation after a typical day of clinical linac use. A mathematical model for the activation level at the isocenter has been established and shown to be useful in explaining and predicting the induced activity levels for typical clinical and experimental conditions. The activation level for a 22 MeV electron beam was also measured and the result shows it is essentially negligible

  3. Chemically induced and light-independent cryptochrome photoreceptor activation.

    Science.gov (United States)

    Rosenfeldt, Gesa; Viana, Rafael Muñoz; Mootz, Henning D; von Arnim, Albrecht G; Batschauer, Alfred

    2008-01-01

    The cryptochrome photoreceptors of higher plants are dimeric proteins. Their N-terminal photosensory domain mediates dimerization, and the unique C-terminal extension (CCT) mediates signaling. We made use of the human FK506-binding protein (FKBP) that binds with high affinity to rapamycin or rapamycin analogs (rapalogs). The FKBP-rapamycin complex is recognized by another protein, FRB, thus allowing rapamycin-induced dimerization of two target proteins. Here we demonstrate by bioluminescence resonance energy transfer (BRET) assays the applicability of this regulated dimerization system to plants. Furthermore, we show that fusion proteins consisting of the C-terminal domain of Arabidopsis cryptochrome 2 fused to FKBP and FRB and coexpressed in Arabidopsis cells specifically induce the expression of cryptochrome-controlled reporter and endogenous genes in darkness upon incubation with the rapalog. These results demonstrate that the activation of cryptochrome signal transduction can be chemically induced in a dose-dependent fashion and uncoupled from the light signal, and provide the groundwork for gain-of-function experiments to study specifically the role of photoreceptors in darkness or in signaling cross-talk even under light conditions that activate members of all photoreceptor families.

  4. A synthetic peptide blocking TRPV1 activation inhibits UV-induced skin responses.

    Science.gov (United States)

    Kang, So Min; Han, Sangbum; Oh, Jang-Hee; Lee, Young Mee; Park, Chi-Hyun; Shin, Chang-Yup; Lee, Dong Hun; Chung, Jin Ho

    2017-10-01

    Transient receptor potential type 1 (TRPV1) can be activated by ultraviolet (UV) irradiation, and mediates UV-induced matrix metalloproteinase (MMP)-1 and proinflammatory cytokines in keratinocytes. Various chemicals and compounds targeting TRPV1 activation have been developed, but are not in clinical use mostly due to their safety issues. We aimed to develop a novel TRPV1-targeting peptide to inhibit UV-induced responses in human skin. We designed and generated a novel TRPV1 inhibitory peptide (TIP) which mimics the specific site in TRPV1 (aa 701-709: Gln-Arg-Ala-Ile-Thr-Ile-Leu-Asp-Thr, QRAITILDT), Thr 705 , and tested its efficacy of blocking UV-induced responses in HaCaT, mouse, and human skin. TIP effectively inhibited capsaicin-induced calcium influx and TRPV1 activation. Treatment of HaCaT with TIP prevented UV-induced increases of MMP-1 and pro-inflammatory cytokines such as interleukin (IL)-6 and tumor necrosis factor-α. In mouse skin in vivo, TIP inhibited UV-induced skin thickening and prevented UV-induced expression of MMP-13 and MMP-9. Moreover, TIP attenuated UV-induced erythema and the expression of MMP-1, MMP-2, IL-6, and IL-8 in human skin in vivo. The novel synthetic peptide targeting TRPV1 can ameliorate UV-induced skin responses in vitro and in vivo, providing a promising therapeutic approach against UV-induced inflammation and photoaging. Copyright © 2017 Japanese Society for Investigative Dermatology. Published by Elsevier B.V. All rights reserved.

  5. Mediator facilitates transcriptional activation and dynamic long-range contacts at the IgH locus during class switch recombination.

    Science.gov (United States)

    Thomas-Claudepierre, Anne-Sophie; Robert, Isabelle; Rocha, Pedro P; Raviram, Ramya; Schiavo, Ebe; Heyer, Vincent; Bonneau, Richard; Luo, Vincent M; Reddy, Janardan K; Borggrefe, Tilman; Skok, Jane A; Reina-San-Martin, Bernardo

    2016-03-07

    Immunoglobulin (Ig) class switch recombination (CSR) is initiated by the transcription-coupled recruitment of activation-induced cytidine deaminase (AID) to Ig switch regions (S regions). During CSR, the IgH locus undergoes dynamic three-dimensional structural changes in which promoters, enhancers, and S regions are brought to close proximity. Nevertheless, little is known about the underlying mechanisms. In this study, we show that Med1 and Med12, two subunits of the mediator complex implicated in transcription initiation and long-range enhancer/promoter loop formation, are dynamically recruited to the IgH locus enhancers and the acceptor regions during CSR and that their knockdown in CH12 cells results in impaired CSR. Furthermore, we show that conditional inactivation of Med1 in B cells results in defective CSR and reduced acceptor S region transcription. Finally, we show that in B cells undergoing CSR, the dynamic long-range contacts between the IgH enhancers and the acceptor regions correlate with Med1 and Med12 binding and that they happen at a reduced frequency in Med1-deficient B cells. Our results implicate the mediator complex in the mechanism of CSR and are consistent with a model in which mediator facilitates the long-range contacts between S regions and the IgH locus enhancers during CSR and their transcriptional activation. © 2016 Thomas-Claudepierre et al.

  6. Induced resistance in tomato by SAR activators during predisposing salinity stress

    Directory of Open Access Journals (Sweden)

    Matthew Francis Pye

    2013-05-01

    Full Text Available Plant activators are chemicals that induce disease resistance. The phytohormone salicylic acid (SA is a crucial signal for systemic acquired resistance (SAR, and SA-mediated resistance is a target of several commercial plant activators, including Actigard (1,2,3-benzothiadiazole-7-thiocarboxylic acid-s-methyl-ester, BTH and Tiadinil (N-(3-chloro-4-methylphenyl-4-methyl-1,2,3-thiadiazole-5-carboxamide, TDL. BTH and TDL were examined for their impact on abscisic acid (ABA-mediated, salt-induced disease predisposition in tomato seedlings. A brief episode of salt stress to roots significantly increased the severity of disease caused by Pseudomonas syringae pv. tomato (Pst and Phytophthora capsici relative to non-stressed plants. Root treatment with TDL induced resistance to Pst in leaves and provided protection in both non-stressed and salt-stressed seedlings in WT and highly susceptible NahG plants. Non-stressed and salt-stressed ABA-deficient sitiens mutants were highly resistant to Pst. Neither TDL nor BTH induced resistance to root infection by P. capsici, nor did they moderate the salt-induced increment in disease severity. Root treatment with these plant activators increased the levels of ABA in roots and shoots similar to levels observed in salt-stressed plants. The results indicate that SAR activators can protect tomato plants from bacterial speck disease under predisposing salt stress, and suggest that some SA-mediated defense responses function sufficiently in plants with elevated levels of ABA.

  7. Activation of Rho GTPases by Cytotoxic Necrotizing Factor 1 Induces Macropinocytosis and Scavenging Activity in Epithelial Cells

    Science.gov (United States)

    Fiorentini, Carla; Falzano, Loredana; Fabbri, Alessia; Stringaro, Annarita; Logozzi, Mariaantonia; Travaglione, Sara; Contamin, Stéphanette; Arancia, Giuseppe; Malorni, Walter; Fais, Stefano

    2001-01-01

    Macropinocytosis, a ruffling-driven process that allows the capture of large material, is an essential aspect of normal cell function. It can be either constitutive, as in professional phagocytes where it ends with the digestion of captured material, or induced, as in epithelial cells stimulated by growth factors. In this case, the internalized material recycles back to the cell surface. We herein show that activation of Rho GTPases by a bacterial protein toxin, the Escherichia coli cytotoxic necrotizing factor 1 (CNF1), allowed epithelial cells to engulf and digest apoptotic cells in a manner similar to that of professional phagocytes. In particular, we have demonstrated that 1) the activation of all Rho, Rac, and Cdc42 by CNF1 was essential for the capture and internalization of apoptotic cells; and 2) such activation allowed the discharge of macropinosomal content into Rab7 and lysosomal associated membrane protein-1 acidic lysosomal vesicles where the ingested particles underwent degradation. Taken together, these findings indicate that CNF1-induced “switching on” of Rho GTPases may induce in epithelial cells a scavenging activity, comparable to that exerted by professional phagocytes. The activation of such activity in epithelial cells may be relevant, in mucosal tissues, in supporting or integrating the scavenging activity of resident macrophages. PMID:11452003

  8. Lytic cell death induced by melittin bypasses pyroptosis but induces NLRP3 inflammasome activation and IL-1β release.

    Science.gov (United States)

    Martín-Sánchez, Fátima; Martínez-García, Juan José; Muñoz-García, María; Martínez-Villanueva, Miriam; Noguera-Velasco, José A; Andreu, David; Rivas, Luís; Pelegrín, Pablo

    2017-08-10

    The nucleotide-binding domain and leucine-rich repeat-containing receptor with a pyrin domain 3 (NLRP3) inflammasome is a sensor for different types of infections and alterations of homeostatic parameters, including abnormally high levels of the extracellular nucleotide ATP or crystallization of different metabolites. All NLRP3 activators trigger a similar intracellular pathway, where a decrease in intracellular K + concentration and permeabilization of plasma membrane are key steps. Cationic amphipathic antimicrobial peptides and peptide toxins permeabilize the plasma membrane. In fact, some of them have been described to activate the NLRP3 inflammasome. Among them, the bee venom antimicrobial toxin peptide melittin is known to elicit an inflammatory reaction via the NLRP3 inflammasome in response to bee venom. Our study found that melittin induces canonical NLRP3 inflammasome activation by plasma membrane permeabilization and a reduction in the intracellular K + concentration. Following melittin treatment, the apoptosis-associated speck-like protein, an adaptor protein with a caspase recruitment domain (ASC), was necessary to activate caspase-1 and induce IL-1β release. However, cell death induced by melittin prevented the formation of large ASC aggregates, amplification of caspase-1 activation, IL-18 release and execution of pyroptosis. Therefore, melittin-induced activation of the NLRP3 inflammasome results in an attenuated inflammasome response that does not result in caspase-1 dependent cell death.

  9. Induced activity in accelerator structures, air and water

    CERN Document Server

    Stevenson, Graham Roger

    2001-01-01

    A summary is given of several 'rules of thumb' which can be used to predict the formation and decay of radionuclides in the structure of accelerators together with the dose rates from the induced radioactivity. Models are also given for the activation of gases (air of the accelerator vault) and liquids (in particular cooling water), together with their transport front the activation region to the release point. (18 refs).

  10. Induced activity in accelerator structures, air and water

    International Nuclear Information System (INIS)

    Stevenson, G.R.

    2001-01-01

    A summary is given of several 'rules of thumb' which can be used to predict the formation and decay of radionuclides in the structure of accelerators together with the dose rates from the induced radioactivity. Models are also given for the activation of gases (air of the accelerator vault) and liquids (in particular cooling water), together with their transport from the activation region to the release point. (author)

  11. Activation of Protease-Activated Receptor 2 Induces VEGF Independently of HIF-1

    DEFF Research Database (Denmark)

    Rasmussen, J.G.; Riis, Simone Elkjær; Frøbert, O.

    2012-01-01

    Human adipose stem cells (hASCs) can promote angiogenesis through secretion of proangiogenic factors such as vascular endothelial growth factor (VEGF). In other cell types, it has been shown that induction of VEGF is mediated by both protease activated receptor 2 (PAR2) and hypoxia inducible fact...

  12. Protective Activity of Dendropanax Morbifera Against Cisplatin-Induced Acute Kidney Injury

    Directory of Open Access Journals (Sweden)

    Eun-Sun Kim

    2015-01-01

    Full Text Available Background/Aims: Drug-induced acute kidney injury (AKI has been a severe threat to hospitalized patients, raising the urgent needs to develop strategies to reduce AKI. We investigated the protective activity of Dendropanax morbifera (DP, a medicinal plant which has been widely used to treat infectious and pain diseases, on acute kidney injury (AKI using cisplatin-induced nephropathic models. Methods: Both in vitro renal tubular cells (NRK-52E and in vivo rat models were used to demonstrate the nephroprotective effect of DP. Results: Methanolic extract from DP significantly reduced cisplatin-induced toxicity in renal tubular cells. Through successive liquid extraction, the extract of DP was separated into n-hexane, CHCl3, EtOAc, n-BuOH, and H2O fractions. Among these, the CHCl3 fraction (DPCF was found to be most potent. The protective activity of DPCF was found to be mediated through anti-oxidant, mitochondrial protective, and anti-apoptotic activities. In in vivo rat models of AKI, treatment with DPCF significantly reversed the cisplatin-induced increase in blood urea nitrogen and serum creatinine and histopathologic damage, recovered the level of anti-oxidant enzymes, and inhibited renal apoptosis. Conclusion: We demonstrated that DP extracts decreased cisplatin-induced renal toxicity, indicating its potential to ameliorate drug-associated acute kidney damage.

  13. Code ACTIVE for calculation of the transmutation, induced activity and decay heat in neutron irradiation

    International Nuclear Information System (INIS)

    Ioki, Kimihiro; Harada, Yuhei; Asami, Naoto.

    1976-03-01

    The computer code ACTIVE has been prepared for calculation of the transmutation rate, induced activity and decay heat. Calculations are carried out with activation chain and spatial distribution of neutron energy spectrum. The spatial distribution of secondary gamma-ray source due to the unstable nuclides is also obtainable. Special attension is paid to the short life decays. (auth.)

  14. Estradiol-induced antinociceptive responses on formalin-induced nociception are independent of COX and HPA activation.

    Science.gov (United States)

    Hunter, Deirtra A; Barr, Gordon A; Amador, Nicole; Shivers, Kai-Yvonne; Kemen, Lynne; Kreiter, Christopher M; Jenab, Shirzad; Inturrisi, Charles E; Quinones-Jenab, Vanya

    2011-07-01

    Estrogen modulates pain perception but how it does so is not fully understood. The aim of this study was to determine if estradiol reduces nociceptive responses in part via hypothalamic-pituitary-adrenal (HPA) axis regulation of cyclooxygenase (COX)-1/COX-2 activity. The first study examined the effects of estradiol (20%) or vehicle with concurrent injection nonsteroidal antiinflammatory drugs (NSAIDs) on formalin-induced nociceptive responding (flinching) in ovariectomized (OVX) rats. The drugs were ibuprofen (COX-1 and COX-2 inhibitor), SC560 (COX-1 inhibitor), or NS398 (COX-2 inhibitor). In a second study, estradiol's effects on formalin-induced nociception were tested in adrenalectomized (ADX), OVX, and ADX+OVX rats. Serum levels of prostaglandins (PG) PGE(2) and corticosterone were measured. Estradiol significantly decreased nociceptive responses in OVX rats with effects during both the first and the second phase of the formalin test. The nonsteroidal antiinflammatory drugs (NSAIDs) did not alter nociception at the doses used here. Adrenalectomy neither altered flinching responses in female rats nor reversed estradiol-induced antinociceptive responses. Estradiol alone had no effect on corticosterone (CORT) or prostaglandin levels after the formalin test, dissociating the effects of estradiol on behavior and these serum markers. Ibuprofen and NS398 significantly reduced PGE2 levels. CORT was not decreased by OVX surgery or by estradiol below that of ADX. Only IBU significantly increased corticosterone levels. Taken together, our results suggest that estradiol-induced antinociception in female rats is independent of COX activity and HPA axis activation. Copyright © 2010 Wiley-Liss, Inc.

  15. Hepatitis B virus e antigen induces activation of rat hepatic stellate cells

    International Nuclear Information System (INIS)

    Zan, Yanlu; Zhang, Yuxia; Tien, Po

    2013-01-01

    Highlights: •HBeAg expression in HSCs induced production of ECM protein and liver fibrotic markers. •The activation and proliferation of HSCs were mediated by TGF-β. •HBeAg protein purified from cell medium directly activated HSCs. -- Abstract: Chronic hepatitis B virus infection is a major cause of hepatic fibrosis, leading to liver cirrhosis and hepatocellular carcinoma. Hepatitis B virus e antigen (HBeAg) is an accessory protein of HBV, not required for viral replication but important for natural infection in vivo. Hepatic stellate cells (HSCs) are the major producers of excessive extracellular matrix during liver fibrogenesis. Therefore, we examined the influence of HBeAg on HSCs. The rat HSC line HSC-T6 was transfected with HBeAg plasmids, and expression of α-smooth muscle actin, collagen I, transforming growth factor-β1 (TGF-β), and tissue inhibitors of metalloproteinase 1 (TIMP-1) was investigated by quantitative real-time PCR. The proliferation of HSCs was determined by MTS analysis. HBeAg transduction induced up-regulation of these fibrogenic genes and proliferation of HSCs. We found that HBeAg induced TGF-β secretion in HSCs, and the activation of HSCs was prevented by a neutralizing anti-TGF-β antibody. Depletion and addition of HBeAg protein in conditioned medium from HSC-T6 cells transduced with HBeAg indicated that HBeAg directly induced the activation and proliferation of rat primary HSCs. Taken together, HBeAg induces the activation and proliferation of HSCs, mainly mediated by TGF-β, and HBeAg protein purified from cell medium can directly activate HSCs

  16. Hepatitis B virus e antigen induces activation of rat hepatic stellate cells

    Energy Technology Data Exchange (ETDEWEB)

    Zan, Yanlu [Center for Molecular Virology, CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Zhang, Yuxia, E-mail: yzhang@wehi.edu.au [Center for Molecular Virology, CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101 (China); Tien, Po, E-mail: tienpo@sun.im.ac.cn [Center for Molecular Virology, CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101 (China)

    2013-06-07

    Highlights: •HBeAg expression in HSCs induced production of ECM protein and liver fibrotic markers. •The activation and proliferation of HSCs were mediated by TGF-β. •HBeAg protein purified from cell medium directly activated HSCs. -- Abstract: Chronic hepatitis B virus infection is a major cause of hepatic fibrosis, leading to liver cirrhosis and hepatocellular carcinoma. Hepatitis B virus e antigen (HBeAg) is an accessory protein of HBV, not required for viral replication but important for natural infection in vivo. Hepatic stellate cells (HSCs) are the major producers of excessive extracellular matrix during liver fibrogenesis. Therefore, we examined the influence of HBeAg on HSCs. The rat HSC line HSC-T6 was transfected with HBeAg plasmids, and expression of α-smooth muscle actin, collagen I, transforming growth factor-β1 (TGF-β), and tissue inhibitors of metalloproteinase 1 (TIMP-1) was investigated by quantitative real-time PCR. The proliferation of HSCs was determined by MTS analysis. HBeAg transduction induced up-regulation of these fibrogenic genes and proliferation of HSCs. We found that HBeAg induced TGF-β secretion in HSCs, and the activation of HSCs was prevented by a neutralizing anti-TGF-β antibody. Depletion and addition of HBeAg protein in conditioned medium from HSC-T6 cells transduced with HBeAg indicated that HBeAg directly induced the activation and proliferation of rat primary HSCs. Taken together, HBeAg induces the activation and proliferation of HSCs, mainly mediated by TGF-β, and HBeAg protein purified from cell medium can directly activate HSCs.

  17. Ouabain exacerbates activation-induced cell death in human peripheral blood lymphocytes

    OpenAIRE

    Esteves Mabel B.; Marques-Santos Luis F.; Affonso-Mitidieri Ottília R.; Rumjanek Vivian M.

    2005-01-01

    Lymphocytes activated by mitogenic lectins display changes in transmembrane potential, an elevation in the cytoplasmic Ca2+ concentrations, proliferation and/or activation induced cell death. Low concentrations of ouabain (an inhibitor of Na+,K+-ATPase) suppress mitogen-induced proliferation and increases cell death. To understand the mechanisms involved, a number of parameters were analyzed using fluorescent probes and flow cytometry. The addition of 100nM ouabain to cultures of peripheral b...

  18. Brucella abortus-activated microglia induce neuronal death through primary phagocytosis.

    Science.gov (United States)

    Rodríguez, Ana M; Delpino, M Victoria; Miraglia, M Cruz; Costa Franco, Miriam M; Barrionuevo, Paula; Dennis, Vida A; Oliveira, Sergio C; Giambartolomei, Guillermo H

    2017-07-01

    Inflammation has long been implicated as a contributor to pathogenesis in neurobrucellosis. Many of the associated neurocognitive symptoms of neurobrucellosis may be the result of neuronal dysfunction resulting from the inflammatory response induced by Brucella abortus infection in the central nervous system. In this manuscript, we describe an immune mechanism for inflammatory activation of microglia that leads to neuronal death upon B. abortus infection. B. abortus was unable to infect or harm primary cultures of mouse neurons. However, when neurons were co-cultured with microglia and infected with B. abortus significant neuronal loss occurred. This phenomenon was dependent on TLR2 activation by Brucella lipoproteins. Neuronal death was not due to apoptosis, but it was dependent on the microglial release of nitric oxide (NO). B. abortus infection stimulated microglial proliferation, phagocytic activity and engulfment of neurons. NO secreted by B. abortus-activated microglia induced neuronal exposure of the "eat-me" signal phosphatidylserine (PS). Blocking of PS-binding to protein milk fat globule epidermal growth factor-8 (MFG-E8) or microglial vitronectin receptor-MFG-E8 interaction was sufficient to prevent neuronal loss by inhibiting microglial phagocytosis without affecting their activation. Taken together, our results indicate that B. abortus is not directly toxic to neurons; rather, these cells become distressed and are killed by phagocytosis in the inflammatory surroundings generated by infected microglia. Neuronal loss induced by B. abortus-activated microglia may explain, in part, the neurological deficits observed during neurobrucellosis. © 2017 Wiley Periodicals, Inc.

  19. Sequential activation of proteases in radiation induced apoptosis

    International Nuclear Information System (INIS)

    Watters, D.; Waterhouse, N.

    1997-01-01

    Full text: Significant advances have been made in recent years in unraveling the molecular mechanisms of apoptosis particularly in relation to Fas- and TNF-mediated cell death, however there are considerable gaps in our knowledge of the processes involved in apoptosis induced by ionizing radiation. We have used the degradation of specific proteolytic targets in a pair of isogenic Burkitt's Iymphoma cells lines (BL30A, sensitive and BL30K resistant) to study the sequence of events in the execution of radiation-induced apoptosis. Fodrin can be cleaved to fragments of 150 kDa and 120 kDa. In the case of Fas-mediated apoptosis both cleavages are inhibited by the caspase inhibitor zVAD-fmk at 10 μM, a concentration which inhibits all the hallmarks of apoptosis. However in radiation-induced apoptosis, inhibition of the clevage of fodrin to the 150 kDa fragment requires 100 μM zVAD-fink while apoptosis itself is inhibited at 10 μM. This suggests that different enzymes are responsible for the generation of the 150 kDa fragment in the two models of apoptosis. Fodrin has been reported to be cleaved by μ-calpain to a 150 kDa fragment however, the involvement of μ-calpain in apoptosis has not yet been established. In murine fodrin there is a caspase cleavage site within 1 kDa of the calpain cleavage site. In vitro studies using purified enzymes showed that only caspase-3 and μ-calpain could cleave fodrin in untreated cell extracts to the same sized fragments as seen during apoptosis in vivo. We provide evidence for the early activation of μ-calpain after ionizing radiation in the sensitive BL30A cell line, and show that the time course of μ-calpain activation parallels that of the appearance of the 150 kDa fragment. Caspase-3 is activated much later and is likely to be responsible for the generation of the 120 kDa fragment. μ-Calpain was not activated in the resistant cell line. Based on these results we propose a model for the proteolytic cascade in radiation-induced

  20. Diversification of the Primary Antibody Repertoire by AID-Mediated Gene Conversion.

    Science.gov (United States)

    Lanning, Dennis K; Knight, Katherine L

    2015-01-01

    Gene conversion, mediated by activation-induced cytidine deaminase (AID), has been found to contribute to generation of the primary antibody repertoire in several vertebrate species. Generation of the primary antibody repertoire by gene conversion of immunoglobulin (Ig) genes occurs primarily in gut-associated lymphoid tissues (GALT) and is best described in chicken and rabbit. Here, we discuss current knowledge of the mechanism of gene conversion as well as the contribution of the microbiota in promoting gene conversion of Ig genes. Finally, we propose that the antibody diversification strategy used in GALT species, such as chicken and rabbit, is conserved in a subset of human and mouse B cells.

  1. Roles of acid sphingomyelinase activation in neuronal cells apoptosis induced by microwave irradiation

    International Nuclear Information System (INIS)

    Zhang Lei; Xu Shangcheng; Zhang Guangbin; Yu Zhengping

    2009-01-01

    The present study is to examine the effect of microwave on acid sphingomyelinase (ASM) activity and expression, and to explore the role of ASM activation in neuronal cells apoptosis induced by microwave irradiation. Primary cultured hippocampal neurons were irradiated by 30 W/cm 2 microwave for 10 min, and ASM activity assay was used to investigate ASM activity alteration. RT-PCR and western blot were used to detect ASM mRNA and protein expression respectively. Apoptosis was observed by Hoechst 33342 fluorescence staining. ASM specific inhibitor imipramine was applied to inhibit ASM activation. It has been found that apoptosis rate of primary cultured hippocampal neurons increased significantly after microwave irradiation. ASM was activated while ASM mRNA and protein expression were upregulated in neurons after microwave irradiation. Pretreatment with imipramine could reverse neuronal apoptosis induced by microwave irradiation. Results show that microwave irradiation causes increment of ASM activation and expression and ASM activation is involved in microwave induced neuronal apoptosis. (authors)

  2. PPARβ/δ regulates glucocorticoid- and sepsis-induced FOXO1 activation and muscle wasting.

    Directory of Open Access Journals (Sweden)

    Estibaliz Castillero

    Full Text Available FOXO1 is involved in glucocorticoid- and sepsis-induced muscle wasting, in part reflecting regulation of atrogin-1 and MuRF1. Mechanisms influencing FOXO1 expression in muscle wasting are poorly understood. We hypothesized that the transcription factor peroxisome proliferator-activated receptor β/δ (PPARβ/δ upregulates muscle FOXO1 expression and activity with a downstream upregulation of atrogin-1 and MuRF1 expression during sepsis and glucocorticoid treatment and that inhibition of PPARβ/δ activity can prevent muscle wasting. We found that activation of PPARβ/δ in cultured myotubes increased FOXO1 activity, atrogin-1 and MuRF1 expression, protein degradation and myotube atrophy. Treatment of myotubes with dexamethasone increased PPARβ/δ expression and activity. Dexamethasone-induced FOXO1 activation and atrogin-1 and MuRF1 expression, protein degradation, and myotube atrophy were inhibited by PPARβ/δ blocker or siRNA. Importantly, muscle wasting induced in rats by dexamethasone or sepsis was prevented by treatment with a PPARβ/δ inhibitor. The present results suggest that PPARβ/δ regulates FOXO1 activation in glucocorticoid- and sepsis-induced muscle wasting and that treatment with a PPARβ/δ inhibitor may ameliorate loss of muscle mass in these conditions.

  3. Growth hormone-induced insulin resistance in human subjects involves reduced pyruvate dehydrogenase activity

    DEFF Research Database (Denmark)

    Nellemann, B.; Vendelbo, M.H.; Nielsen, Thomas Svava

    2014-01-01

    Insulin resistance induced by growth hormone (GH) is linked to promotion of lipolysis by unknown mechanisms. We hypothesized that suppression of the activity of pyruvate dehydrogenase in the active form (PDHa) underlies GH-induced insulin resistance similar to what is observed during fasting....

  4. Substrate Stiffness Influences Doxorubicin-Induced p53 Activation via ROCK2 Expression

    Directory of Open Access Journals (Sweden)

    Takahiro Ebata

    2017-01-01

    Full Text Available The physical properties of the extracellular matrix (ECM, such as stiffness, are involved in the determination of the characteristics of cancer cells, including chemotherapy sensitivity. Resistance to chemotherapy is often linked to dysfunction of tumor suppressor p53; however, it remains elusive whether the ECM microenvironment interferes with p53 activation in cancer cells. Here, we show that, in MCF-7 breast cancer cells, extracellular stiffness influences p53 activation induced by the antitumor drug doxorubicin. Cell growth inhibition by doxorubicin was increased in response to ECM rigidity in a p53-dependent manner. The expression of Rho-associated coiled coil-containing protein kinase (ROCK 2, which induces the activation of myosin II, was significantly higher when cells were cultured on stiffer ECM substrates. Knockdown of ROCK2 expression or pharmacological inhibition of ROCK decreased doxorubicin-induced p53 activation. Our results suggest that a soft ECM causes downregulation of ROCK2 expression, which drives resistance to chemotherapy by repressing p53 activation.

  5. Kainate-induced network activity in the anterior cingulate cortex.

    Science.gov (United States)

    Shinozaki, R; Hojo, Y; Mukai, H; Hashizume, M; Murakoshi, T

    2016-06-14

    Anterior cingulate cortex (ACC) plays a pivotal role in higher order processing of cognition, attention and emotion. The network oscillation is considered an essential means for integration of these CNS functions. The oscillation power and coherence among related areas are often dis-regulated in several psychiatric and pathological conditions with a hemispheric asymmetric manner. Here we describe the network-based activity of field potentials recorded from the superficial layer of the mouse ACC in vitro using submerged type recordings. A short activation by kainic acid administration to the preparation induced populational activities ranging over several frequency bands including theta (3-8Hz), alpha (8-12Hz), beta (13-30Hz), low gamma (30-50Hz) and high gamma (50-80Hz). These responses were repeatable and totally abolished by tetrodotoxin, and greatly diminished by inhibitors of ionotropic and metabotropic glutamate receptors, GABAA receptor or gap-junctions. These observations suggest that the kainate-induced network activity can be a useful model of the network oscillation in the ACC circuit. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  6. Artemisinin induces ROS-mediated caspase3 activation in ASTC-a-1 cells

    Science.gov (United States)

    Xiao, Feng-Lian; Chen, Tong-Sheng; Qu, Jun-Le; Liu, Cheng-Yi

    2010-02-01

    Artemisinin (ART), an antimalarial phytochemical from the sweet wormwood plant or a naturally occurring component of Artemisia annua, has been shown a potential anticancer activity by apoptotic pathways. In our report, cell counting kit (CCK-8) assay showed that treatment of human lung adenocarcinoma (ASTC-a-1) cells with ART effectively increase cell death by inducing apoptosis in a time- and dose-dependent fashion. Hoechst 33258 staining was used to detect apoptosis as well. Reactive oxygen species (ROS) generation was observed in cells exposed to ART at concentrations of 400 μM for 48 h. N-acetyl-L-cysteine (NAC), an oxygen radical scavenger, suppressed the rate of ROS generation and inhibited the ART-induced apoptosis. Moreover, AFC assay (Fluorometric assay for Caspase3 activity) showed that ROS was involved in ART-induced caspase3 acitvation. Taken together, our data indicate that ART induces ROS-mediated caspase3 activation in a time-and dose-dependent way in ASCT-a-1 cells.

  7. Involvement of microglia activation in the lead induced long-term potentiation impairment.

    Directory of Open Access Journals (Sweden)

    Ming-Chao Liu

    Full Text Available Exposure of Lead (Pb, a known neurotoxicant, can impair spatial learning and memory probably via impairing the hippocampal long-term potentiation (LTP as well as hippocampal neuronal injury. Activation of hippocampal microglia also impairs spatial learning and memory. Thus, we raised the hypothesis that activation of microglia is involved in the Pb exposure induced hippocampal LTP impairment and neuronal injury. To test this hypothesis and clarify its underlying mechanisms, we investigated the Pb-exposure on the microglia activation, cytokine release, hippocampal LTP level as well as neuronal injury in in vivo or in vitro model. The changes of these parameters were also observed after pretreatment with minocycline, a microglia activation inhibitor. Long-term low dose Pb exposure (100 ppm for 8 weeks caused significant reduction of LTP in acute slice preparations, meanwhile, such treatment also significantly increased hippocampal microglia activation as well as neuronal injury. In vitro Pb-exposure also induced significantly increase of microglia activation, up-regulate the release of cytokines including tumor necrosis factor-alpha (TNF-α, interleukin-1β (IL-1β and inducible nitric oxide synthase (iNOS in microglia culture alone as well as neuronal injury in the co-culture with hippocampal neurons. Inhibiting the microglia activation with minocycline significantly reversed the above-mentioned Pb-exposure induced changes. Our results showed that Pb can cause microglia activation, which can up-regulate the level of IL-1β, TNF-α and iNOS, these proinflammatory factors may cause hippocampal neuronal injury as well as LTP deficits.

  8. Extracellular adenosine-induced Rac1 activation in pulmonary endothelium: Molecular mechanisms and barrier-protective role.

    Science.gov (United States)

    Kovacs-Kasa, Anita; Kim, Kyung Mi; Cherian-Shaw, Mary; Black, Stephen M; Fulton, David J; Verin, Alexander D

    2018-08-01

    We have previously shown that Gs-coupled adenosine receptors (A2a) are primarily involved in adenosine-induced human pulmonary artery endothelial cell (HPAEC) barrier enhancement. However, the downstream events that mediate the strengthening of the endothelial cell (EC) barrier via adenosine signaling are largely unknown. In the current study, we tested the overall hypothesis that adenosine-induced Rac1 activation and EC barrier enhancement is mediated by Gs-dependent stimulation of cAMP-dependent Epac1-mediated signaling cascades. Adenoviral transduction of HPAEC with constitutively-active (C/A) Rac1 (V12Rac1) significantly increases transendothelial electrical resistance (TER) reflecting an enhancement of the EC barrier. Conversely, expression of an inactive Rac1 mutant (N17Rac1) decreases TER reflecting a compromised EC barrier. The adenosine-induced increase in TER was accompanied by activation of Rac1, decrease in contractility (MLC dephosphorylation), but not Rho inhibition. Conversely, inhibition of Rac1 activity attenuates adenosine-induced increase in TER. We next examined the role of cAMP-activated Epac1 and its putative downstream targets Rac1, Vav2, Rap1, and Tiam1. Depletion of Epac1 attenuated the adenosine-induced Rac1 activation and the increase in TER. Furthermore, silencing of Rac1 specific guanine nucleotide exchange factors (GEFs), Vav2 and Rap1a expression significantly attenuated adenosine-induced increases in TER and activation of Rac1. Depletion of Rap1b only modestly impacted adenosine-induced increases in TER and Tiam1 depletion had no effect on adenosine-induced Rac1 activation and TER. Together these data strongly suggest that Rac1 activity is required for adenosine-induced EC barrier enhancement and that the activation of Rac1 and ability to strengthen the EC barrier depends, at least in part, on cAMP-dependent Epac1/Vav2/Rap1-mediated signaling. © 2017 Wiley Periodicals, Inc.

  9. Minocycline attenuates sevoflurane-induced cell injury via activation of Nrf2.

    Science.gov (United States)

    Tian, Yue; Wu, Xiuying; Guo, Shanbin; Ma, Ling; Huang, Wei; Zhao, Xiaochun

    2017-04-01

    Minocycline has been demonstrated to exert neuroprotective effects in various experimental models. In the present study, we investigated the mechanisms underlying the protective effects of minocycline on cell injury induced by the inhalation of the anesthetic, sevoflurane. In our in vivo experiments using rats, minocycline attenuated sevoflurane-induced neuronal degeneration and apoptosis in the rat hippocampus, and this effect was associated with the minocycline-mediated suppression of oxidative stress in the hippocampus. In in vitro experiments, minocycline inhibited sevoflurane-induced apoptosis and the production of reactive oxygen species (ROS) in H4 human neuroglioma cells. In addition, minocycline suppressed the sevoflurane-induced upregulation of interleukin (IL)-6 and the activation of the nuclear factor-κB (NF-κB) signaling pathway in H4 cells. Furthermore, we found that nuclear factor E2-related factor 2 (Nrf2), an activator of the stress response, was upregulated and activated upon sevoflurane treatment both in the rat hippocampus and in H4 cells. In addition, minocycline further augmented the upregulation and activation of Nrf2 when used in conjunction with sevoflurane. Moreover, the knockdown of Nrf2 in H4 cells by small interfering RNA (siRNA) diminished the cytoprotective effect of minocycline, and attenuated the inhibitory effect of minocycline on ROS production, IL-6 upregulation and the activation of the NF-κB signaling pathway. On the whole, our findings indicate that minocycline may exert protective effects against sevoflurane-induced cell injury via the Nrf2-modulated antioxidant response and the inhibition of the activation of the NF-κB signaling pathway.

  10. Active-interrogation measurements of fast neutrons from induced fission in low-enriched uranium

    International Nuclear Information System (INIS)

    Dolan, J.L.; Marcath, M.J.; Flaska, M.; Pozzi, S.A.; Chichester, D.L.; Tomanin, A.; Peerani, P.

    2014-01-01

    A detection system was designed with MCNPX-PoliMi to measure induced-fission neutrons from U-235 and U-238 using active interrogation. Measurements were then performed with this system at the Joint Research Centre in Ispra, Italy on low-enriched uranium samples. Liquid scintillators measured induced fission neutrons to characterize the samples in terms of their uranium mass and enrichment. Results are presented to investigate and support the use of organic liquid scintillators with active interrogation techniques to characterize uranium containing materials. -- Highlights: • We studied low-enriched uranium using active-interrogation experiments including a deuterium–tritium neutron generator and an americium–lithium isotopic neutron source. • Liquid scintillators measured induced-fission neutrons from the active-interrogation methods. • Fast-neutron (DT) and thermal-neutron (Am–Li) interrogation resulted in the measurement of trends in uranium mass and 235 U enrichment respectively. • MCNPX-PoliMi, the Monte Carlo transport code, simulated the measured induced-fission neutron trends in the liquid scintillators

  11. Active-interrogation measurements of fast neutrons from induced fission in low-enriched uranium

    Energy Technology Data Exchange (ETDEWEB)

    Dolan, J.L., E-mail: jldolan@umich.edu [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Marcath, M.J.; Flaska, M.; Pozzi, S.A. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Chichester, D.L. [Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Tomanin, A.; Peerani, P. [European Commission, Joint Research Centre, Institute for Transuranium Elements, Ispra (Italy)

    2014-02-21

    A detection system was designed with MCNPX-PoliMi to measure induced-fission neutrons from U-235 and U-238 using active interrogation. Measurements were then performed with this system at the Joint Research Centre in Ispra, Italy on low-enriched uranium samples. Liquid scintillators measured induced fission neutrons to characterize the samples in terms of their uranium mass and enrichment. Results are presented to investigate and support the use of organic liquid scintillators with active interrogation techniques to characterize uranium containing materials. -- Highlights: • We studied low-enriched uranium using active-interrogation experiments including a deuterium–tritium neutron generator and an americium–lithium isotopic neutron source. • Liquid scintillators measured induced-fission neutrons from the active-interrogation methods. • Fast-neutron (DT) and thermal-neutron (Am–Li) interrogation resulted in the measurement of trends in uranium mass and {sup 235}U enrichment respectively. • MCNPX-PoliMi, the Monte Carlo transport code, simulated the measured induced-fission neutron trends in the liquid scintillators.

  12. Troglitazone induced apoptosis via PPARγ activated POX-induced ROS formation in HT29 cells.

    Science.gov (United States)

    Wang, Jing; Lv, XiaoWen; Shi, JiePing; Hu, XiaoSong; DU, YuGuo

    2011-08-01

    In order to investigate the potential mechanisms in troglitazone-induced apoptosis in HT29 cells, the effects of PPARγ and POX-induced ROS were explored. [3- (4, 5)-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) assay, Annexin V and PI staining using FACS, plasmid transfection, ROS formation detected by DCFH staining, RNA interference, RT-PCR & RT-QPCR, and Western blotting analyses were employed to investigate the apoptotic effect of troglitazone and the potential role of PPARγ pathway and POX-induced ROS formation in HT29 cells. Troglitazone was found to inhibit the growth of HT29 cells by induction of apoptosis. During this process, mitochondria related pathways including ROS formation, POX expression and cytochrome c release increased, which were inhibited by pretreatment with GW9662, a specific antagonist of PPARγ. These results illustrated that POX upregulation and ROS formation in apoptosis induced by troglitazone was modulated in PPARγ-dependent pattern. Furthermore, the inhibition of ROS and apoptosis after POX siRNA used in troglitazone-treated HT29 cells indicated that POX be essential in the ROS formation and PPARγ-dependent apoptosis induced by troglitazone. The findings from this study showed that troglitazone-induced apoptosis was mediated by POX-induced ROS formation, at least partly, via PPARγ activation. Copyright © 2011 The Editorial Board of Biomedical and Environmental Sciences. Published by Elsevier B.V. All rights reserved.

  13. Role of Bioavailable Iron in Coal Dust-Induced Activation of Activator Protein-1 and Nuclear Factor of Activated T Cells

    Science.gov (United States)

    Huang, Chuanshu; Li, Jingxia; Zhang, Qi; Huang, Xi

    2010-01-01

    Activator protein-1 (AP-1) and nuclear factor of activated T cells (NFAT) are two important transcription factors responsible for the regulation of cytokines, which are involved in cell proliferation and inflammation. Coal workers’ pneumoconiosis (CWP) is an occupational lung disease that may be related to chronic inflammation caused by coal dust exposure. In the present study, we demonstrate that coal from the Pennsylvania (PA) coalmine region, which has a high prevalence of CWP, can activate both AP-1 and NFAT in JB6 mouse epidermal cells. In contrast, coal from the Utah (UT) coalmine region, which has a low prevalence of CWP, has no such effects. The PA coal stimulates mitogen-activated protein kinase (MAPK) family members of extracellular signal-regulated kinases (ERKs) and p38 MAPK but not c-Jun-NH2-terminal kinases, as determined by the phosphorylation assay. The increase in AP-1 by the PA coal was completely eliminated by the pretreatment of cells with PD98059, a specific MAPK kinase inhibitor, and SB202190, a p38 kinase inhibitor, further confirming that the PA coal-induced AP-1 activation is mediated through ERKs and p38 MAPK pathways. Deferoxamine (DFO), an iron chelator, synergistically enhanced the PA coal-induced AP-1 activity, but inhibited NFAT activity. For comparison, cells were treated with ferrous sulfate and/or DFO. We have found that iron transactivated both AP-1 and NFAT, and DFO further enhanced iron-induced AP-1 activation but inhibited NFAT. These results indicate that activation of AP-1 and NFAT by the PA coal is through bioavailable iron present in the coal. These data are in agreement with our previous findings that the prevalence of CWP correlates well with levels of bioavailable iron in coals from various mining regions. PMID:12397016

  14. Natural Product Vibsanin A Induces Differentiation of Myeloid Leukemia Cells through PKC Activation.

    Science.gov (United States)

    Yu, Zu-Yin; Xiao, He; Wang, Li-Mei; Shen, Xing; Jing, Yu; Wang, Lin; Sun, Wen-Feng; Zhang, Yan-Feng; Cui, Yu; Shan, Ya-Jun; Zhou, Wen-Bing; Xing, Shuang; Xiong, Guo-Lin; Liu, Xiao-Lan; Dong, Bo; Feng, Jian-Nan; Wang, Li-Sheng; Luo, Qing-Liang; Zhao, Qin-Shi; Cong, Yu-Wen

    2016-05-01

    All-trans retinoic acid (ATRA)-based cell differentiation therapy has been successful in treating acute promyelocytic leukemia, a unique subtype of acute myeloid leukemia (AML). However, other subtypes of AML display resistance to ATRA-based treatment. In this study, we screened natural, plant-derived vibsane-type diterpenoids for their ability to induce differentiation of myeloid leukemia cells, discovering that vibsanin A potently induced differentiation of AML cell lines and primary blasts. The differentiation-inducing activity of vibsanin A was mediated through direct interaction with and activation of protein kinase C (PKC). Consistent with these findings, pharmacological blockade of PKC activity suppressed vibsanin A-induced differentiation. Mechanistically, vibsanin A-mediated activation of PKC led to induction of the ERK pathway and decreased c-Myc expression. In mouse xenograft models of AML, vibsanin A administration prolonged host survival and inhibited PKC-mediated inflammatory responses correlated with promotion of skin tumors in mice. Collectively, our results offer a preclinical proof of concept for vibsanin A as a myeloid differentiation-inducing compound, with potential application as an antileukemic agent. Cancer Res; 76(9); 2698-709. ©2016 AACR. ©2016 American Association for Cancer Research.

  15. Creatine kinase activity in dogs with experimentally induced acute inflammation

    Directory of Open Access Journals (Sweden)

    Dimitrinka Zapryanova

    2013-01-01

    Full Text Available The main purpose of this study was to investigate the effect of acute inflammation on total creatine kinase (CK activity in dogs. In these animals, CK is an enzyme found predominantly in skeletal muscle and significantly elevated serum activity is largely associated with muscle damage. Plasma increases in dogs are associated with cell membrane leakage and will therefore be seen in any condition associated with muscular inflammation. The study was induced in 15 mongrel male dogs (n=9 in experimental group and n=6 in control group at the age of two years and body weight 12-15 kg. The inflammation was reproduced by inoculation of 2 ml turpentine oil subcutaneously in lumbar region. The plasma activity of creatine kinase was evaluated at 0, 6, 24, 48, 72 hours after inoculation and on days 7, 14 and 21 by a kit from Hospitex Diagnostics. In the experimental group, the plasma concentrations of the CK-activity were increased at the 48th hour (97.48±6.92 U/L and remained significantly higher (p<0.05 at the 72 hour (97.43±2.93 U/L compared to the control group (77.08±5.27 U/L. The results of this study suggest that the evaluation of creatine kinase in dogs with experimentally induced acute inflammation has a limited diagnostic value. It was observed that the creatine kinase activity is slightly affected by the experimentally induced acute inflammation in dogs.

  16. Gut-associated lymphoid tissue contains the molecular machinery to support T-cell-dependent and T-cell-independent class switch recombination.

    Science.gov (United States)

    Barone, F; Patel, P; Sanderson, J D; Spencer, J

    2009-11-01

    A PRoliferation-Inducing Ligand (APRIL) is a secreted cytokine member of the tumor necrosis factor family. It is a B-cell survival factor that also induces class switch recombination (CSR) toward immunoglobulin A (IgA), independent of T cells. It is therefore an important contributor to the maintenance of the mucosal immunological barrier, which has been linked to a putative extrafollicular inductive phase of the IgA response in lamina propria. By immunohistochemistry (IHC) and quantitative real-time PCR (qRT-PCR) on microdissected tissue from normal human gut, we observed APRIL expression, together with TACI (transmembrane activator and CAML interactor) and BCMA (B-cell maturation antigen), in gut-associated lymphoid tissue (GALT), lamina propria, and in the epithelium of stomach, small and large intestine, and rectum. However, no activation-induced cytidine deaminase (AID) expression (an absolute requirement for class switching) was detected in lamina propria by IHC or qRT-PCR. APRIL and its receptors were only observed alongside AID in GALT, showing that GALT contains the apparatus to support both T-independent and T-dependent routes to IgA CSR.

  17. Modern g,d,p,n-induced activation-transmutation systems

    International Nuclear Information System (INIS)

    Sublet, J.Ch.

    2010-01-01

    Document available in abstract form only. Full text of publication follows: The European Activation System (EASY) includes as the source of nuclear data the European Activation File (EAF) and as its engine the FISPACT activation-transmutation code. The latest version of the EAF, EAF-2010, contains cross-section data for gamma-, deuteron- and proton-induced reactions in addition to the traditional neutron-induced data. The main reason for the addition of these data to EAF is to enable activation-transmutation calculations to be performed for even more nuclear facilities, including 'accelerator'-driven devices with incident upper energy limit of 60 or 200 MeV. EAF-2010 has benefited from the generation and maintenance of comprehensive activation files in the past and the development of the processing code SAFEPAQ-II and model code TALYS. TALYS is the source for all gamma-, proton- and deuteron-induced data and a fair share of the neutron-induced data. Cross-section validation exercises against both experimental data and systematic, which were started in 1995, enable a comprehensive assessment of the data. Although EAF-2010 is certainly the most-validated activation neutron cross-section library in the world, currently less than 3% of all the reactions can be compared with experimental information, and even then only for a very limited, and not always application-relevant, energy range. As with EAF-2010, -2003, -2005 and -2007 results of integral experiments have been used to correct, adjust and validate data. This can be done using SAFEPAQ II by inputting the measured effective cross-sections. Validation using integral data has been performed by means of direct comparison with measurements of various materials under relevant particle spectra. A tool has recently been developed which is important now that the libraries contain so much TALYS-calculated data. Statistical analysis of cross-sections (SACS) is used to look for trends in the library data for a particular

  18. PPARγ ligands decrease hydrostatic pressure-induced platelet aggregation and proinflammatory activity.

    Directory of Open Access Journals (Sweden)

    Fang Rao

    Full Text Available Hypertension is known to be associated with platelet overactivity, but the direct effects of hydrostatic pressure on platelet function remain unclear. The present study sought to investigate whether elevated hydrostatic pressure is responsible for platelet activation and to address the potential role of peroxisome proliferator-activated receptor-γ (PPARγ. We observed that hypertensive patients had significantly higher platelet volume and rate of ADP-induced platelets aggregation compared to the controls. In vitro, Primary human platelets were cultured under standard (0 mmHg or increased (120, 180, 240 mmHg hydrostatic pressure for 18 h. Exposure to elevated pressure was associated with morphological changes in platelets. Platelet aggregation and PAC-1 (the active confirmation of GPIIb/IIIa binding were increased, CD40L was translocated from cytoplasm to the surface of platelet and soluble CD40L (sCD40L was released into the medium in response to elevated hydrostatic pressure (180 and 240 mmHg. The PPARγ activity was up-regulated as the pressure was increased from 120 mmHg to 180 mmHg. Pressure-induced platelet aggregation, PAC-1 binding, and translocation and release of CD40L were all attenuated by the PPARγ agonist Thiazolidinediones (TZDs. These results demonstrate that platelet activation and aggregation are increased by exposure to elevated pressure and that PPARγ may modulate platelet activation induced by high hydrostatic pressure.

  19. PPARγ ligands decrease hydrostatic pressure-induced platelet aggregation and proinflammatory activity.

    Science.gov (United States)

    Rao, Fang; Yang, Ren-Qiang; Chen, Xiao-Shu; Xu, Jin-Song; Fu, Hui-Min; Su, Hai; Wang, Ling

    2014-01-01

    Hypertension is known to be associated with platelet overactivity, but the direct effects of hydrostatic pressure on platelet function remain unclear. The present study sought to investigate whether elevated hydrostatic pressure is responsible for platelet activation and to address the potential role of peroxisome proliferator-activated receptor-γ (PPARγ). We observed that hypertensive patients had significantly higher platelet volume and rate of ADP-induced platelets aggregation compared to the controls. In vitro, Primary human platelets were cultured under standard (0 mmHg) or increased (120, 180, 240 mmHg) hydrostatic pressure for 18 h. Exposure to elevated pressure was associated with morphological changes in platelets. Platelet aggregation and PAC-1 (the active confirmation of GPIIb/IIIa) binding were increased, CD40L was translocated from cytoplasm to the surface of platelet and soluble CD40L (sCD40L) was released into the medium in response to elevated hydrostatic pressure (180 and 240 mmHg). The PPARγ activity was up-regulated as the pressure was increased from 120 mmHg to 180 mmHg. Pressure-induced platelet aggregation, PAC-1 binding, and translocation and release of CD40L were all attenuated by the PPARγ agonist Thiazolidinediones (TZDs). These results demonstrate that platelet activation and aggregation are increased by exposure to elevated pressure and that PPARγ may modulate platelet activation induced by high hydrostatic pressure.

  20. Anti-apoptotic BFL-1 is the major effector in activation-induced human mast cell survival.

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    Maria Ekoff

    Full Text Available Mast cells are best known for their role in allergic reactions, where aggregation of FcεRI leads to the release of mast cell mediators causing allergic symptoms. The activation also induces a survival program in the cells, i.e., activation-induced mast cell survival. The aim of the present study was to investigate how the activation-induced survival is mediated. Cord blood-derived mast cells and the mast cell line LAD-2 were activated through FcεRI crosslinking, with or without addition of chemicals that inhibit the activity or expression of selected Bcl-2 family members (ABT-737; roscovitine. Cell viability was assessed using staining and flow cytometry. The expression and function of Bcl-2 family members BFL-1 and MCL-1 were investigated using real-time quantitative PCR and siRNA treatment. The mast cell expression of Bfl-1 was investigated in skin biopsies. FcεRI crosslinking promotes activation-induced survival of human mast cells and this is associated with an upregulation of the anti-apoptotic Bcl-2 family member Bfl-1. ABT-737 alone or in combination with roscovitine decreases viability of human mast cells although activation-induced survival is sustained, indicating a minor role for Bcl-X(L, Bcl-2, Bcl-w and Mcl-1. Reducing BFL-1 but not MCL-1 levels by siRNA inhibited activation-induced mast cell survival. We also demonstrate that mast cell expression of Bfl-1 is elevated in birch-pollen-provocated skin and in lesions of atopic dermatitis and psoriasis patients. Taken together, our results highlight Bfl-1 as a major effector in activation-induced human mast cell survival.

  1. CD36 participates in PrP(106-126-induced activation of microglia.

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    Mohammed Kouadir

    Full Text Available Microglial activation is a characteristic feature of the pathogenesis of prion diseases. The molecular mechanisms that underlie prion-induced microglial activation are not very well understood. In the present study, we investigated the role of the class B scavenger receptor CD36 in microglial activation induced by neurotoxic prion protein (PrP fragment 106-126 (PrP(106-126. We first examined the time course of CD36 mRNA expression upon exposure to PrP(106-126 in BV2 microglia. We then analyzed different parameters of microglial activation in PrP(106-126-treated cells in the presence or not of anti-CD36 monoclonal antibody (mAb. The cells were first incubated for 1 h with CD36 monoclonal antibody to block the CD36 receptor, and were then treated with neurotoxic prion peptides PrP(106-126. The results showed that PrP(106-126 treatment led to a rapid yet transitory increase in the mRNA expression of CD36, upregulated mRNA and protein levels of proinflammatory cytokines (IL-1β, IL-6 and TNF-α, increased iNOS expression and nitric oxide (NO production, stimulated the activation of NF-κB and caspase-1, and elevated Fyn activity. The blockade of CD36 had no effect on PrP(106-126-stimulated NF-κB activation and TNF-α protein release, abrogated the PrP(106-126-induced iNOS stimulation, downregulated IL-1β and IL-6 expression at both mRNA and protein levels as well as TNF-α mRNA expression, decreased NO production and Fyn phosphorylation, reduced caspase-1 cleavage induced by moderate PrP(106-126-treatment, but had no effect on caspase-1 activation after treatment with a high concentration of PrP(106-126. Together, these results suggest that CD36 is involved in PrP(106-126-induced microglial activation and that the participation of CD36 in the interaction between PrP(106-126 and microglia may be mediated by Src tyrosine kinases. Our findings provide new insights into the mechanisms underlying the activation of microglia by neurotoxic prion peptides

  2. Opioid-Induced Glial Activation: Mechanisms of Activation and Implications for Opioid Analgesia, Dependence, and Reward

    Directory of Open Access Journals (Sweden)

    Mark R. Hutchinson

    2007-01-01

    Full Text Available This review will introduce the concept of toll-like receptor (TLR–mediated glial activation as central to all of the following: neuropathic pain, compromised acute opioid analgesia, and unwanted opioid side effects (tolerance, dependence, and reward. Attenuation of glial activation has previously been demonstrated both to alleviate exaggerated pain states induced by experimental pain models and to reduce the development of opioid tolerance. Here we demonstrate that selective acute antagonism of TLR4 results in reversal of neuropathic pain as well as potentiation of opioid analgesia. Attenuating central nervous system glial activation was also found to reduce the development of opioid dependence, and opioid reward at a behavioral (conditioned place preference and neurochemical (nucleus accumbens microdialysis of morphine-induced elevations in dopamine level of analysis. Moreover, a novel antagonism of TLR4 by (+- and (˗-isomer opioid antagonists has now been characterized, and both antiallodynic and morphine analgesia potentiating activity shown. Opioid agonists were found to also possess TLR4 agonistic activity, predictive of glial activation. Targeting glial activation is a novel and as yet clinically unexploited method for treatment of neuropathic pain. Moreover, these data indicate that attenuation of glial activation, by general or selective TLR antagonistic mechanisms, may also be a clinical method for separating the beneficial (analgesia and unwanted (tolerance, dependence, and reward actions of opioids, thereby improving the safety and efficacy of their use.

  3. Oscillatory brain activity in spontaneous and induced sleep stages in flies.

    Science.gov (United States)

    Yap, Melvyn H W; Grabowska, Martyna J; Rohrscheib, Chelsie; Jeans, Rhiannon; Troup, Michael; Paulk, Angelique C; van Alphen, Bart; Shaw, Paul J; van Swinderen, Bruno

    2017-11-28

    Sleep is a dynamic process comprising multiple stages, each associated with distinct electrophysiological properties and potentially serving different functions. While these phenomena are well described in vertebrates, it is unclear if invertebrates have distinct sleep stages. We perform local field potential (LFP) recordings on flies spontaneously sleeping, and compare their brain activity to flies induced to sleep using either genetic activation of sleep-promoting circuitry or the GABA A agonist Gaboxadol. We find a transitional sleep stage associated with a 7-10 Hz oscillation in the central brain during spontaneous sleep. Oscillatory activity is also evident when we acutely activate sleep-promoting neurons in the dorsal fan-shaped body (dFB) of Drosophila. In contrast, sleep following Gaboxadol exposure is characterized by low-amplitude LFPs, during which dFB-induced effects are suppressed. Sleep in flies thus appears to involve at least two distinct stages: increased oscillatory activity, particularly during sleep induction, followed by desynchronized or decreased brain activity.

  4. The hydroxyflavone, fisetin, suppresses mast cell activation induced by interaction with activated T cell membranes

    Science.gov (United States)

    Nagai, K; Takahashi, Y; Mikami, I; Fukusima, T; Oike, H; Kobori, M

    2009-01-01

    Background and purpose: Cell-to-cell interactions between mast cells and activated T cells are increasingly recognized as a possible mechanism in the aetiology of allergic or non-allergic inflammatory disorders. To determine the anti-allergic effect of fisetin, we examined the ability of fisetin to suppress activation of the human mast cell line, HMC-1, induced by activated Jurkat T cell membranes. Experimental approach: HMC-1 cells were incubated with or without fisetin for 15 min and then co-cultured with Jurkat T cell membranes activated by phorbol-12-myristate 13-acetate for 16 h. We determined gene expression in activated HMC-1 cells by DNA microarray and quantitative reverse transcription (RT)-PCR analysis. We also examined activation of the transcription factor NF-κB and MAP kinases (MAPKs) in activated HMC-1 cells. Key results: Fisetin suppresses cell spreading and gene expression in HMC-1 cells stimulated by activated T cell membranes. Additionally, we show that these stimulated HMC-1 cells expressed granzyme B. The stimulatory interaction also induced activation of NF-κB and MAPKs; these activations were suppressed by fisetin. Fisetin also reduced the amount of cell surface antigen CD40 and intercellular adhesion molecule-1 (ICAM-1) on activated HMC-1 cells. Conclusions and implications: Fisetin suppressed activation of HMC-1 cells by activated T cell membranes by interfering with cell-to-cell interaction and inhibiting the activity of NF-κB and MAPKs and thereby suppressing gene expression. Fisetin may protect against the progression of inflammatory diseases by limiting interactions between mast cells and activated T cells. PMID:19702784

  5. Glucose-induced serum- and glucocorticoid-regulated kinase activation in oncofetal fibronectin expression

    International Nuclear Information System (INIS)

    Khan, Zia A.; Barbin, Yousef P.; Farhangkhoee, Hana; Beier, Norbert; Scholz, Wolfgang; Chakrabarti, Subrata

    2005-01-01

    Preferential expression of oncofetal extra domain-B fibronectin (EDB + FN), a proposed angiogenic marker, has been shown in proliferative diabetic retinopathy. High levels of glucose also increase EDB + FN expression in endothelial cells (ECs) via transforming growth factor-β1 (TGF-β1) and endothelin-1 (ET-1). The present study was aimed at elucidating the role of serum- and glucocorticoid-regulated kinase (SGK-1) in glucose-induced EDB + FN expression. Using human macro- and microvascular ECs, we show that high levels of glucose, TGF-β1, and ET-1 increase the EDB + FN expression via SGK-1 alteration at the mRNA, protein, and activity levels. Inhibition of TGF-β1 and ET-1 prevented glucose-induced SGK-1 activation and the EDB + FN expression. Furthermore, using siRNA-mediated SGK-1 gene silencing, we show that glucose-induced EDB + FN expression can be completely prevented. These findings provide first evidence of glucose-induced SGK-1 activation in altered EDB + FN expression and provide novel avenues for therapeutic modalities

  6. Abnormal-induced theta activity supports early directed-attention network deficits in progressive MCI.

    Science.gov (United States)

    Deiber, Marie-Pierre; Ibañez, Vicente; Missonnier, Pascal; Herrmann, François; Fazio-Costa, Lara; Gold, Gabriel; Giannakopoulos, Panteleimon

    2009-09-01

    The electroencephalography (EEG) theta frequency band reacts to memory and selective attention paradigms. Global theta oscillatory activity includes a posterior phase-locked component related to stimulus processing and a frontal-induced component modulated by directed attention. To investigate the presence of early deficits in the directed attention-related network in elderly individuals with mild cognitive impairment (MCI), time-frequency analysis at baseline was used to assess global and induced theta oscillatory activity (4-6Hz) during n-back working memory tasks in 29 individuals with MCI and 24 elderly controls (EC). At 1-year follow-up, 13 MCI patients were still stable and 16 had progressed. Baseline task performance was similar in stable and progressive MCI cases. Induced theta activity at baseline was significantly reduced in progressive MCI as compared to EC and stable MCI in all n-back tasks, which were similar in terms of directed attention requirements. While performance is maintained, the decrease of induced theta activity suggests early deficits in the directed-attention network in progressive MCI, whereas this network is functionally preserved in stable MCI.

  7. The expression of apoB mRNA editing factors is not the sole determinant for the induction of editing in differentiating Caco-2 cells

    International Nuclear Information System (INIS)

    Galloway, Chad A.; Smith, Harold C.

    2010-01-01

    Apolipoprotein B mRNA is edited at cytidine 6666 in the enterocytes lining the small intestine of all mammals; converting a CAA codon to a UAA stop codon. The conversion is ∼80% efficient in this tissue and leads to the expression of the truncated protein, ApoB48, essential for secretion of dietary lipid as chylomicrons. Caco-2 cell raft cultures have been used as an in vitro model for the induction of editing activity during human small intestinal cell differentiation. This induction of apoB mRNA editing has been ascribed to the expression of APOBEC-1. In agreement our data demonstrated differentiation-dependent induction of expression of the editing enzyme APOBEC-1 and in addition we show alternative splicing of the essential auxiliary factor ACF. However, transfection of these editing factors in undifferentiated proliferating Caco-2 cells was not sufficient to induce robust apoB mRNA editing activity. Only differentiation of Caco-2 cells could induce more physiological like levels of apoB mRNA editing. The data suggested that additional regulatory mechanism(s) were induced by differentiation that controlled the functional activity of editing factors.

  8. Belinostat-induced apoptosis and growth inhibition in pancreatic cancer cells involve activation of TAK1-AMPK signaling axis

    International Nuclear Information System (INIS)

    Wang, Bing; Wang, Xin-bao; Chen, Li-yu; Huang, Ling; Dong, Rui-zen

    2013-01-01

    Highlights: •Belinostat activates AMPK in cultured pancreatic cancer cells. •Activation of AMPK is important for belinostat-induced cytotoxic effects. •ROS and TAK1 are involved in belinostat-induced AMPK activation. •AMPK activation mediates mTOR inhibition by belinostat. -- Abstract: Pancreatic cancer accounts for more than 250,000 deaths worldwide each year. Recent studies have shown that belinostat, a novel pan histone deacetylases inhibitor (HDACi) induces apoptosis and growth inhibition in pancreatic cancer cells. However, the underlying mechanisms are not fully understood. In the current study, we found that AMP-activated protein kinase (AMPK) activation was required for belinostat-induced apoptosis and anti-proliferation in PANC-1 pancreatic cancer cells. A significant AMPK activation was induced by belinostat in PANC-1 cells. Inhibition of AMPK by RNAi knockdown or dominant negative (DN) mutation significantly inhibited belinostat-induced apoptosis in PANC-1 cells. Reversely, AMPK activator AICAR and A-769662 exerted strong cytotoxicity in PANC-1 cells. Belinostat promoted reactive oxygen species (ROS) production in PANC-1 cells, increased ROS induced transforming growth factor-β-activating kinase 1 (TAK1)/AMPK association to activate AMPK. Meanwhile, anti-oxidants N-Acetyl-Cysteine (NAC) and MnTBAP as well as TAK1 shRNA knockdown suppressed belinostat-induced AMPK activation and PANC-1 cell apoptosis. In conclusion, we propose that belinostat-induced apoptosis and growth inhibition require the activation of ROS-TAK1-AMPK signaling axis in cultured pancreatic cancer cells

  9. Belinostat-induced apoptosis and growth inhibition in pancreatic cancer cells involve activation of TAK1-AMPK signaling axis

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Bing, E-mail: wangbin69@yahoo.com; Wang, Xin-bao; Chen, Li-yu; Huang, Ling; Dong, Rui-zen

    2013-07-19

    Highlights: •Belinostat activates AMPK in cultured pancreatic cancer cells. •Activation of AMPK is important for belinostat-induced cytotoxic effects. •ROS and TAK1 are involved in belinostat-induced AMPK activation. •AMPK activation mediates mTOR inhibition by belinostat. -- Abstract: Pancreatic cancer accounts for more than 250,000 deaths worldwide each year. Recent studies have shown that belinostat, a novel pan histone deacetylases inhibitor (HDACi) induces apoptosis and growth inhibition in pancreatic cancer cells. However, the underlying mechanisms are not fully understood. In the current study, we found that AMP-activated protein kinase (AMPK) activation was required for belinostat-induced apoptosis and anti-proliferation in PANC-1 pancreatic cancer cells. A significant AMPK activation was induced by belinostat in PANC-1 cells. Inhibition of AMPK by RNAi knockdown or dominant negative (DN) mutation significantly inhibited belinostat-induced apoptosis in PANC-1 cells. Reversely, AMPK activator AICAR and A-769662 exerted strong cytotoxicity in PANC-1 cells. Belinostat promoted reactive oxygen species (ROS) production in PANC-1 cells, increased ROS induced transforming growth factor-β-activating kinase 1 (TAK1)/AMPK association to activate AMPK. Meanwhile, anti-oxidants N-Acetyl-Cysteine (NAC) and MnTBAP as well as TAK1 shRNA knockdown suppressed belinostat-induced AMPK activation and PANC-1 cell apoptosis. In conclusion, we propose that belinostat-induced apoptosis and growth inhibition require the activation of ROS-TAK1-AMPK signaling axis in cultured pancreatic cancer cells.

  10. Lung vagal afferent activity in rats with bleomycin-induced lung fibrosis.

    Science.gov (United States)

    Schelegle, E S; Walby, W F; Mansoor, J K; Chen, A T

    2001-05-01

    Bleomycin treatment in rats results in pulmonary fibrosis that is characterized by a rapid shallow breathing pattern, a decrease in quasi-static lung compliance and a blunting of the Hering-Breuer Inflation Reflex. We examined the impulse activity of pulmonary vagal afferents in anesthetized, mechanically ventilated rats with bleomycin-induced lung fibrosis during the ventilator cycle and static lung inflations/deflations and following the injection of capsaicin into the right atrium. Bleomycin enhanced volume sensitivity of slowly adapting stretch receptors (SARs), while it blunted the sensitivity of these receptors to increasing transpulmonary pressure. Bleomycin treatment increased the inspiratory activity, while it decreased the expiratory activity of rapidly adapting stretch receptors (RARs). Pulmonary C-fiber impulse activity did not appear to be affected by bleomycin treatment. We conclude that the fibrosis-related shift in discharge profile and enhanced volume sensitivity of SARs combined with the increased inspiratory activity of RARs contributes to the observed rapid shallow breathing of bleomycin-induced lung fibrosis.

  11. New strategy of cancer therapy by targeting the hypoxic circumstances

    International Nuclear Information System (INIS)

    Yasui, Hironobu; Yamamori, Tohru; Meike, Shunsuke; Eitaki, Masato; Kuwabara, Mikinori; Inanami, Osamu; Iizuka, Daisuke

    2010-01-01

    Described are studies on the sensitization of tumor cells in hypoxic circumstances (known as radio-resistant cells) by authors' recent molecular targeting to adaptive response as well as by the usual agents like nitro-imidazole compounds, and on the intermittent hypoxia, a new topic in this field. The hypoxia-inducible factor-1 (HIF-1) is a transcriptional factor and has been known to activate its many downstream genes to cause adoptive response of hypoxic cells. Authors have studied the anti-tumor and radiation sensitizing effects of ethynyl-cytidine (EC) which is found to suppress RNA synthesis through cytidine kinase (CK) inhibition, and the compound is of specificity to tumor cells as they have 5-10 times higher CK activity than normal cells. Authors have also found that EC is of the sensitizing efficacy to normoxic and hypoxic cells by enhancing the radiation-induced apoptosis essentially through inhibition of HIF-1 expression. Intermittent hypoxia in the tumor which has characteristic abnormal vascular morphology and function, occurs by the transient reduction of blood flow and occlusion of vessels in the tissue within minute to hour time cycles. Little is known about the regional hypoxic region and its distribution in the tumor due to difficulty of their detection and quantification. For this, authors have measured the temporal changes of oxygen levels in the mouse tumor with triaryl methyl radical, an oxygen-sensitive contrast compound continuously injected, by microwave-pulsed electron spin resonance imaging (EPRI). By superimposing the EPRI and T2-weighted MRI, the oxymetric imaging is possible in the tumor, which reveals the difference of oxygen level variation depending on the cell type and tissue size. Findings in the field are expected to give important information for more effective cancer therapy and its prognostic prediction in future. (T.T.)

  12. Anesthetic propofol attenuates the isoflurane-induced caspase-3 activation and Aβ oligomerization.

    Directory of Open Access Journals (Sweden)

    Yiying Zhang

    Full Text Available Accumulation and deposition of β-amyloid protein (Aβ are the hallmark features of Alzheimer's disease. The inhalation anesthetic isoflurane has been shown to induce caspase activation and increase Aβ accumulation. In addition, recent studies suggest that isoflurane may directly promote the formation of cytotoxic soluble Aβ oligomers, which are thought to be the key pathological species in AD. In contrast, propofol, the most commonly used intravenous anesthetic, has been reported to have neuroprotective effects. We therefore set out to compare the effects of isoflurane and propofol alone and in combination on caspase-3 activation and Aβ oligomerization in vitro and in vivo. Naïve and stably-transfected H4 human neuroglioma cells that express human amyloid precursor protein, the precursor for Aβ; neonatal mice; and conditioned cell culture media containing secreted human Aβ40 or Aβ42 were treated with isoflurane and/or propofol. Here we show for the first time that propofol can attenuate isoflurane-induced caspase-3 activation in cultured cells and in the brain tissues of neonatal mice. Furthermore, propofol-mediated caspase inhibition occurred when there were elevated levels of Aβ. Finally, isoflurane alone induces Aβ42, but not Aβ40, oligomerization, and propofol can inhibit the isoflurane-mediated oligomerization of Aβ42. These data suggest that propofol may mitigate the caspase-3 activation by attenuating the isoflurane-induced Aβ42 oligomerization. Our findings provide novel insights into the possible mechanisms of isoflurane-induced neurotoxicity that may aid in the development of strategies to minimize potential adverse effects associated with the administration of anesthetics to patients.

  13. Allergen-Removed Rhus verniciflua Extract Induces Ovarian Cancer Cell Death via JNK Activation.

    Science.gov (United States)

    Kang, Se-Hui; Hwang, In-Hu; Son, Eunju; Cho, Chong-Kwan; Choi, Jong-Soon; Park, Soo-Jung; Jang, Byeong-Churl; Lee, Kyung-Bok; Lee, Zee-Won; Lee, Jong Hoon; Yoo, Hwa-Seung; Jang, Ik-Soon

    2016-01-01

    Nuclear factor-[Formula: see text]B (NF-[Formula: see text]B)/Rel transcription factors are best known for their central roles in promoting cell survival in cancer. NF-[Formula: see text]B antagonizes tumor necrosis factor (TNF)-[Formula: see text]-induced apoptosis through a process involving attenuation of the c-Jun-N-terminal kinase (JNK). However, the role of JNK activation in apoptosis induced by negative regulation of NF-[Formula: see text]B is not completely understood. We found that allergen-removed Rhus verniciflua Stokes (aRVS) extract-mediated NF-[Formula: see text]B inhibition induces apoptosis in SKOV-3 ovarian cancer cells via the serial activation of caspases and SKOV-3 cells are most specifically suppressed by aRVS. Here, we show that in addition to activating caspases, aRVS extract negatively modulates the TNF-[Formula: see text]-mediated I[Formula: see text]B/NF-[Formula: see text]B pathway to promote JNK activation, which results in apoptosis. When the cytokine TNF-[Formula: see text] binds to the TNF receptor, I[Formula: see text]B dissociates from NF-[Formula: see text]B. As a result, the active NF-[Formula: see text]B translocates to the nucleus. aRVS extract (0.5[Formula: see text]mg/ml) clearly prevented NF-[Formula: see text]B from mobilizing to the nucleus, resulting in the upregulation of JNK phosphorylation. This subsequently increased Bax activation, leading to marked aRVS-induced apoptosis, whereas the JNK inhibitor SP600125 in aRVS extract treated SKOV-3 cells strongly inhibited Bax. Bax subfamily proteins induced apoptosis through caspase-3. Thus, these results indicate that aRVS extract contains components that inhibit NF-[Formula: see text]B signaling to upregulate JNK activation in ovarian cancer cells and support the potential of aRVS as a therapeutic agent for ovarian cancer.

  14. Arctigenin Inhibits Adipogenesis by Inducing AMPK Activation and Reduces Weight Gain in High-Fat Diet-Induced Obese Mice.

    Science.gov (United States)

    Han, Yo-Han; Kee, Ji-Ye; Park, Jinbong; Kim, Hye-Lin; Jeong, Mi-Young; Kim, Dae-Seung; Jeon, Yong-Deok; Jung, Yunu; Youn, Dong-Hyun; Kang, JongWook; So, Hong-Seob; Park, Raekil; Lee, Jong-Hyun; Shin, Soyoung; Kim, Su-Jin; Um, Jae-Young; Hong, Seung-Heon

    2016-09-01

    Although arctigenin (ARC) has been reported to have some pharmacological effects such as anti-inflammation, anti-cancer, and antioxidant, there have been no reports on the anti-obesity effect of ARC. The aim of this study is to investigate whether ARC has an anti-obesity effect and mediates the AMP-activated protein kinase (AMPK) pathway. We investigated the anti-adipogenic effect of ARC using 3T3-L1 pre-adipocytes and human adipose tissue-derived mesenchymal stem cells (hAMSCs). In high-fat diet (HFD)-induced obese mice, whether ARC can inhibit weight gain was investigated. We found that ARC reduced weight gain, fat pad weight, and triglycerides in HFD-induced obese mice. ARC also inhibited the expression of peroxisome proliferator-activated receptor gamma (PPARγ) and CCAAT/enhancer-binding protein alpha (C/EBPα) in in vitro and in vivo. Furthermore, ARC induced the AMPK activation resulting in down-modulation of adipogenesis-related factors including PPARγ, C/EBPα, fatty acid synthase, adipocyte fatty acid-binding protein, and lipoprotein lipase. This study demonstrates that ARC can reduce key adipogenic factors by activating the AMPK in vitro and in vivo and suggests a therapeutic implication of ARC for obesity treatment. J. Cell. Biochem. 117: 2067-2077, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  15. TATA-binding protein-associated factor 7 regulates polyamine transport activity and polyamine analog-induced apoptosis.

    Science.gov (United States)

    Fukuchi, Junichi; Hiipakka, Richard A; Kokontis, John M; Nishimura, Kazuhiro; Igarashi, Kazuei; Liao, Shutsung

    2004-07-16

    Identification of the polyamine transporter gene will be useful for modulating polyamine accumulation in cells and should be a good target for controlling cell proliferation. Polyamine transport activity in mammalian cells is critical for accumulation of the polyamine analog methylglyoxal bis(guanylhydrazone) (MGBG) that induces apoptosis, although a gene responsible for transport activity has not been identified. Using a retroviral gene trap screen, we generated MGBG-resistant Chinese hamster ovary (CHO) cells to identify genes involved in polyamine transport activity. One gene identified by the method encodes TATA-binding protein-associated factor 7 (TAF7), which functions not only as one of the TAFs, but also a coactivator for c-Jun. TAF7-deficient cells had decreased capacity for polyamine uptake (20% of CHO cells), decreased AP-1 activation, as well as resistance to MGBG-induced apoptosis. Stable expression of TAF7 in TAF7-deficient cells restored transport activity (55% of CHO cells), AP-1 gene transactivation (100% of CHO cells), and sensitivity to MGBG-induced apoptosis. Overexpression of TAF7 in CHO cells did not increase transport activity, suggesting that TAF7 may be involved in the maintenance of basal activity. c-Jun NH2-terminal kinase inhibitors blocked MGBG-induced apoptosis without alteration of polyamine transport. Decreased TAF7 expression, by RNA interference, in androgen-independent human prostate cancer LN-CaP104-R1 cells resulted in lower polyamine transport activity (25% of control) and resistance to MGBG-induced growth arrest. Taken together, these results reveal a physiological function of TAF7 as a basal regulator for mammalian polyamine transport activity and MGBG-induced apoptosis.

  16. A bacterial cocaine esterase protects against cocaine-induced epileptogenic activity and lethality.

    Science.gov (United States)

    Jutkiewicz, Emily M; Baladi, Michelle G; Cooper, Ziva D; Narasimhan, Diwahar; Sunahara, Roger K; Woods, James H

    2009-09-01

    Cocaine toxicity results in cardiovascular complications, seizures, and death and accounts for approximately 20% of drug-related emergency department visits every year. Presently, there are no treatments to eliminate the toxic effects of cocaine. The present study hypothesizes that a bacterial cocaine esterase with high catalytic efficiency would provide rapid and robust protection from cocaine-induced convulsions, epileptogenic activity, and lethality. Cocaine-induced paroxysmal activity and convulsions were evaluated in rats surgically implanted with radiotelemetry devices (N=6 per treatment group). Cocaine esterase was administered 1 minute after a lethal dose of cocaine or after cocaine-induced convulsions to determine the ability of the enzyme to prevent or reverse, respectively, the effects of cocaine. The cocaine esterase prevented all cocaine-induced electroencephalographic changes and lethality. This effect was specific for cocaine because the esterase did not prevent convulsions and death induced by a cocaine analog, (-)-2beta-carbomethoxy-3beta-phenyltropane. The esterase prevented lethality even after cocaine-induced convulsions occurred. In contrast, the short-acting benzodiazepine, midazolam, prevented cocaine-induced convulsions but not the lethal effects of cocaine. The data showed that cocaine esterase successfully degraded circulating cocaine to prevent lethality and that cocaine-induced convulsions alone are not responsible for the lethal effects of cocaine in this model. Therefore, further investigation into the use of cocaine esterase for treating cocaine overdose and its toxic effects is warranted.

  17. The NALP3 inflammasome is involved in neurotoxic prion peptide-induced microglial activation

    Directory of Open Access Journals (Sweden)

    Shi Fushan

    2012-07-01

    Full Text Available Abstract Background Prion diseases are neurodegenerative disorders characterized by the accumulation of an abnormal disease-associated prion protein, PrPSc. In prion-infected brains, activated microglia are often present in the vicinity of PrPSc aggregates, and microglial activation is thought to play a key role in the pathogenesis of prion diseases. Although interleukin (IL-1β release by prion-induced microglia has been widely reported, the mechanism by which primed microglia become activated and secrete IL-1β in prion diseases has not yet been elucidated. In this study, we investigated the role of the NACHT, LRR and PYD domains-containing protein (NALP3 inflammasome in IL-1β release from lipopolysaccharide (LPS-primed microglia after exposure to a synthetic neurotoxic prion fragment (PrP106-126. Methods The inflammasome components NALP3 and apoptosis-associated speck-like protein (ASC were knocked down by gene silencing. IL-1β production was assessed using ELISA. The mRNA expression of NALP3, ASC, and pro-inflammatory factors was measured by quantitative PCR. Western blot analysis was used to detect the protein level of NALP3, ASC, caspase-1 and nuclear factor-κB. Results We found that that PrP106-126-induced IL-1β release depends on NALP3 inflammasome activation, that inflammasome activation is required for the synthesis of pro-inflammatory and chemotactic factors by PrP106-126-activated microglia, that inhibition of NF-κB activation abrogated PrP106-126-induced NALP3 upregulation, and that potassium efflux and production of reactive oxygen species were implicated in PrP106-126-induced NALP3 inflammasome activation in microglia. Conclusions We conclude that the NALP3 inflammasome is involved in neurotoxic prion peptide-induced microglial activation. To our knowledge, this is the first time that strong evidence for the involvement of NALP3 inflammasome in prion-associated inflammation has been found.

  18. Shanxi Aged Vinegar Protects against Alcohol-Induced Liver Injury via Activating Nrf2-Mediated Antioxidant and Inhibiting TLR4-Induced Inflammatory Response

    Directory of Open Access Journals (Sweden)

    Ting Xia

    2018-06-01

    Full Text Available Shanxi aged vinegar (SAV is a typical fermented and antioxidant food, which has various health-promoting effects. This work aimed to explore the effects of SAV on alcohol-induced liver injury. A mice model of alcoholic liver injury was established to illuminate its potential mechanisms. All mice pretreated with SAV and then received an ethanol solution (50% w/v, 4.8 g/kg b.w.. The results showed that SAV ameliorated alcohol-induced histological changes and elevation of liver enzymes. SAV attenuated alcohol-induced oxidative stress by declining levels of hepatic oxidants, and restoring depletion of antioxidant enzyme activities in mice livers. Moreover, SAV alleviated alcohol-induced oxidative damage by activating nuclear factor erythroid-2-related factor 2 (Nrf2-mediated signal pathway. In addition, SAV prevented alcohol-induced inflammation by suppressing lipopolysaccharide (LPS level and activities of pro-inflammatory enzymes, and regulating inflammatory cytokines. SAV inhibited alcohol-induced inflammation through down-regulating the expression of Toll-like receptor 4 (TLR4-mediated inflammatory response. The findings provide crucial evidence for elucidating the hepatoprotective mechanisms of SAV and encourage the future application of SAV as a functional food for liver protection.

  19. Non-transactivational, dual pathways for LPA-induced Erk1/2 activation in primary cultures of brown pre-adipocytes

    International Nuclear Information System (INIS)

    Holmstroem, Therese E.; Mattsson, Charlotte L.; Wang, Yanling; Iakovleva, Irina; Petrovic, Natasa; Nedergaard, Jan

    2010-01-01

    In many cell types, G-protein-coupled receptor (GPCR)-induced Erk1/2 MAP kinase activation is mediated via receptor tyrosine kinase (RTK) transactivation, in particular via the epidermal growth factor (EGF) receptor. Lysophosphatidic acid (LPA), acting via GPCRs, is a mitogen and MAP kinase activator in many systems, and LPA can regulate adipocyte proliferation. The mechanism by which LPA activates the Erk1/2 MAP kinase is generally accepted to be via EGF receptor transactivation. In primary cultures of brown pre-adipocytes, EGF can induce Erk1/2 activation, which is obligatory and determinant for EGF-induced proliferation of these cells. Therefore, we have here examined whether LPA, via EGF transactivation, can activate Erk1/2 in brown pre-adipocytes. We found that LPA could induce Erk1/2 activation. However, the LPA-induced Erk1/2 activation was independent of transactivation of EGF receptors (or PDGF receptors) in these cells (whereas in transformed HIB-1B brown adipocytes, the LPA-induced Erk1/2 activation indeed proceeded via EGF receptor transactivation). In the brown pre-adipocytes, LPA instead induced Erk1/2 activation via two distinct non-transactivational pathways, one G i -protein dependent, involving PKC and Src activation, the other, a PTX-insensitive pathway, involving PI3K (but not Akt) activation. Earlier studies showing LPA-induced Erk1/2 activation being fully dependent on RTK transactivation have all been performed in cell lines and transfected cells. The present study implies that in non-transformed systems, RTK transactivation may not be involved in the mediation of GPCR-induced Erk1/2 MAP kinase activation.

  20. Hyperthyroidism enhances 5-HT-induced contraction of the rat pulmonary artery: role of calcium-activated chloride channel activation.

    Science.gov (United States)

    Oriowo, Mabayoje A; Oommen, Elsie; Khan, Islam

    2011-11-01

    Experimentally-induced hyperthyroidism in rodents is associated with signs and symptoms of pulmonary hypertension. The main objective of the present study was to investigate the effect of thyroxine-induced pulmonary hypertension on the contractile response of the pulmonary artery to 5-HT and the possible underlying signaling pathway. 5-HT concentration-dependently contracted artery segments from control and thyroxine-treated rats with pD(2) values of 5.04 ± 0.19 and 5.34 ± 0.14, respectively. The maximum response was significantly greater in artery segments from thyroxine-treated rats. Neither BW 723C86 (5-HT(2B)-receptor agonist) nor CP 93129 (5-HT(1B)-receptor agonist) contracted ring segments of the pulmonary artery from control and thyroxine-treated rats at concentrations up to 10(-4)M. There was no significant difference in the level of expression of 5-HT(2A)-receptor protein between the two groups. Ketanserin (3 × 10(-8)M) produced a rightward shift of the concentration-response curve to 5-HT in both groups with equal potency (-logK(B) values were 8.1 ± 0.2 and 7.9 ± 0.1 in control and thyroxine-treated rats, respectively). Nifedipine (10(-6)M) inhibited 5-HT-induced contractions in artery segments from control and thyroxine-treated rats and was more effective against 5-HT-induced contraction in artery segments for thyroxine-treated rats. The calcium-activated chloride channel blocker, niflumic acid (10(-4)M) also inhibited 5-HT-induced contractions in artery segments from control and thyroxine-treated rats and was more effective against 5-HT-induced contraction in artery segments for thyroxine-treated rats. It was concluded that hyperthyroidism enhanced 5-HT-induced contractions of the rat pulmonary artery by a mechanism involving increased activity of calcium-activated chloride channels. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. UVC-induced apoptosis in Dubca cells is independent of JNK activation and p53Ser-15 phosphorylation

    International Nuclear Information System (INIS)

    Chathoth, Shahanas; Thayyullathil, Faisal; Hago, Abdulkader; Shahin, Allen; Patel, Mahendra; Galadari, Sehamuddin

    2009-01-01

    Ultraviolet C (UVC) irradiation in mammalian cell lines activates a complex signaling network that leads to apoptosis. By using Dubca cells as a model system, we report the presence of a UVC-induced apoptotic pathway that is independent of c-Jun N-terminal kinases (JNKs) activation and p53 phosphorylation at Ser 15 . Irradiation of Dubca cells with UVC results in a rapid JNK activation and phosphorylation of its downstream target c-Jun, as well as, phosphorylation of activating transcription factor 2 (ATF2). Pre-treatment with JNK inhibitor, SP600125, inhibited UVC-induced c-Jun phosphorylation without preventing UVC-induced apoptosis. Similarly, inhibition of UVC-induced p53 phosphorylation did not prevent Dubca cell apoptosis, suggesting that p53 Ser-15 phosphorylation is not associated with UVC-induced apoptosis signaling. The pan-caspase inhibitor z-VAD-fmk inhibited UVC-induced PARP cleavage, DNA fragmentation, and ultimately apoptosis of Dubca cells. Altogether, our study clearly indicates that UVC-induced apoptosis is independent of JNK and p53 activation in Dubca cells, rather, it is mediated through a caspase dependent pathway. Our findings are not in line with the ascribed critical role for JNKs activation, and downstream phosphorylation of targets such as c-Jun and ATF2 in UVC-induced apoptosis.

  2. Impurities and evaluation of induced activity of SiCf/SiC composites

    International Nuclear Information System (INIS)

    Noda, Tetsuji; Araki, Hiroshi; Ito, Shinji; Fujita, Mitsutane; Maki, Koichi

    1997-01-01

    Impurity of SiC f /SiC composites prepared by CVI was analyzed by neutron activation analysis and glow discharge mass spectrometry. The evaluation of the induced activity of the composites based on the chemical compositions was made using a simulation calculation for fusion reactor blanket. Impurities of 35 elements were detected in the composites. However the total concentration of metallic impurities was below 20 mass ppm. The analyses of induced activity of the composites show that the dose rate decreases by about 5 orders of magnitude in a day after the shutdown. It is recommended that the purification of SiC fibers is necessary to reduce the activity by 10 9 after several ten years cooling of fusion reactors. (author)

  3. p38 mitogen-activated protein kinase up-regulates NF-κB transcriptional activation through RelA phosphorylation during stretch-induced myogenesis

    International Nuclear Information System (INIS)

    Ji, Guoping; Liu, Dongxu; Liu, Jing; Gao, Hui; Yuan, Xiao; Shen, Gang

    2010-01-01

    p38 MAPK and nuclear factor-B (NF-B) signaling pathways play an indispensable role in the control of skeletal myogenesis. The specific contribution of these signaling pathways to the response of myoblast to the mechanical stimulation and the molecular mechanisms underlying this response remain unresolved. Using an established in vitro model, we now show that p38 MAP kinase activity regulates the transcriptional activation of NF-κB in response to mechanical stimulation of myoblasts. Furthermore, SB203580 blocked stretch-induced NF-κB activation during myogenesis, not through down-regulation of degradation of IκB-α, and consequent translocation of the p65 subunit of NF-κB to the nucleus. It is likely that stretch-induced NF-κB activation by phosphorylation of p65 NF-κB. Moreover, depletion of p38α using siRNA significantly reduces stretch-induced phosphorylation of RelA and NF-κB activity. These results provides the first evidence of a cross-talk between p38 MAPK and NF-κB signaling pathways during stretch-induced myogenesis, with phosphorylation of RelA being one of the effectors of this promyogenic mechanism. The α isoform of p38MAP kinase regulates the transcriptional activation of NF-κB following stimulation with cyclic stretch.

  4. p38 mitogen-activated protein kinase up-regulates NF-{kappa}B transcriptional activation through RelA phosphorylation during stretch-induced myogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Guoping [Department of Orthodontics, College of Stomatology, Ninth People' s Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai Research Institute of Stomatology, Shanghai 200011 (China); Liu, Dongxu [Department of Orthodontics, College of Stomatology, Shandong University, Jinan, Shandong Province 250012 (China); Liu, Jing [Department of Orthodontics, The Affiliated Qingdao Municipal Hospital, Qingdao University, Qingdao, Shandong Province 266075 (China); Gao, Hui [Department of Orthodontics, Tianjin Stomatological Hospital, Tianjin 300041 (China); Yuan, Xiao, E-mail: yuanxiaoqd@163.com [Department of Orthodontics, The Affiliated Qingdao Municipal Hospital, Qingdao University, Qingdao, Shandong Province 266075 (China); Shen, Gang, E-mail: ganshen2007@163.com [Department of Orthodontics, College of Stomatology, Ninth People' s Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai Research Institute of Stomatology, Shanghai 200011 (China)

    2010-01-01

    p38 MAPK and nuclear factor-B (NF-B) signaling pathways play an indispensable role in the control of skeletal myogenesis. The specific contribution of these signaling pathways to the response of myoblast to the mechanical stimulation and the molecular mechanisms underlying this response remain unresolved. Using an established in vitro model, we now show that p38 MAP kinase activity regulates the transcriptional activation of NF-{kappa}B in response to mechanical stimulation of myoblasts. Furthermore, SB203580 blocked stretch-induced NF-{kappa}B activation during myogenesis, not through down-regulation of degradation of I{kappa}B-{alpha}, and consequent translocation of the p65 subunit of NF-{kappa}B to the nucleus. It is likely that stretch-induced NF-{kappa}B activation by phosphorylation of p65 NF-{kappa}B. Moreover, depletion of p38{alpha} using siRNA significantly reduces stretch-induced phosphorylation of RelA and NF-{kappa}B activity. These results provides the first evidence of a cross-talk between p38 MAPK and NF-{kappa}B signaling pathways during stretch-induced myogenesis, with phosphorylation of RelA being one of the effectors of this promyogenic mechanism. The {alpha} isoform of p38MAP kinase regulates the transcriptional activation of NF-{kappa}B following stimulation with cyclic stretch.

  5. Damage-induced DNA replication stalling relies on MAPK-activated protein kinase 2 activity

    DEFF Research Database (Denmark)

    Köpper, Frederik; Bierwirth, Cathrin; Schön, Margarete

    2013-01-01

    knockdown of the MAP kinase-activated protein kinase 2 (MK2), a kinase currently implicated in p38 stress signaling and G2 arrest. Depletion or inhibition of MK2 also protected cells from DNA damage-induced cell death, and mice deficient for MK2 displayed decreased apoptosis in the skin upon UV irradiation...

  6. Irradiation-induced telomerase activity and gastric cancer risk: a case-control analysis in a Chinese Han population

    International Nuclear Information System (INIS)

    He, Xianli; Qiao, Qing; Ge, Naijian; Nan, Jing; Shen, Shuqun; Wang, Zizhong; Yang, Yefa; Bao, Guoqiang

    2010-01-01

    Telomerase expression is one of the characteristics of gastric cancer (GC) cells and telomerase activity is frequently up-regulated by a variety of mechanisms during GC development. Therefore, we hypothesized that elevated levels of activated telomerase might enhance GC risk due to increased propagation of cells with DNA damage, such as induced by γ-radiation. To explore this hypothesis, 246 GC cases and 246 matched controls were recruited in our case-control study. TRAP-ELISA was used to assess the levels of telomerase activity at baseline and after γ-radiation and the γ-radiation-induced telomerase activity (defined as after γ-irradiation/baseline) in cultured peripheral blood lymphocytes (PBLs). Our data showed that there was no significant difference for the baseline telomerase activity between GC cases and controls (10.17 ± 7.21 vs. 11.02 ± 8.03, p = 0.168). However, after γ-radiation treatment, γ-radiation-induced telomerase activity was significantly higher in the cases than in the controls (1.51 ± 0.93 vs. 1.22 ± 0.66, p < 0.001). Using the median value of γ-radiation-induced telomerase activity in the controls as a cutoff point, we observed that high γ-radiation-induced telomerase activity was associated with a significantly increased GC risk (adjusted odds ratio, 2.45; 95% confidence interval, 1.83-3.18). Moreover, a dose response association was noted between γ-radiation-induced telomerase activity and GC risk. Age, but not sex, smoking and drinking status seem to have a modulating effect on the γ-radiation-induced telomerase activities in both cases and controls. Overall, our findings for the first time suggest that the increased γ-radiation-induced telomerase activity in PBLs might be associated with elevated GC risk. Further confirmation of this association using a prospective study design is warranted

  7. VEGF secretion during hypoxia depends on free radicals-induced Fyn kinase activity in mast cells

    International Nuclear Information System (INIS)

    Garcia-Roman, Jonathan; Ibarra-Sanchez, Alfredo; Lamas, Monica; Gonzalez Espinosa, Claudia

    2010-01-01

    Research highlights: → Bone marrow-derived mast cells (BMMCs) secrete functional VEGF but do not degranulate after Cobalt chloride-induced hypoxia. → CoCl 2 -induced VEGF secretion in mast cells occurs by a Ca 2+ -insensitive but brefeldin A and Tetanus toxin-sensitive mechanism. → Trolox and N-acetylcysteine inhibit hypoxia-induced VEGF secretion but only Trolox inhibits FcεRI-dependent anaphylactic degranulation in mast cells. → Src family kinase Fyn activation after free radical production is necessary for hypoxia-induced VEGF secretion in mast cells. -- Abstract: Mast cells (MC) have an important role in pathologic conditions such as asthma and chronic obstructive pulmonary disease (COPD), where hypoxia conduce to deleterious inflammatory response. MC contribute to hypoxia-induced angiogenesis producing factors such as vascular endothelial growth factor (VEGF), but the mechanisms behind the control of hypoxia-induced VEGF secretion in this cell type is poorly understood. We used the hypoxia-mimicking agent cobalt chloride (CoCl 2 ) to analyze VEGF secretion in murine bone marrow-derived mast cells (BMMCs). We found that CoCl 2 promotes a sustained production of functional VEGF, able to induce proliferation of endothelial cells in vitro. CoCl 2 -induced VEGF secretion was independent of calcium rise but dependent on tetanus toxin-sensitive vesicle-associated membrane proteins (VAMPs). VEGF exocytosis required free radicals formation and the activation of Src family kinases. Interestingly, an important deficiency on CoCl 2 -induced VEGF secretion was observed in Fyn kinase-deficient BMMCs. Moreover, Fyn kinase was activated by CoCl 2 in WT cells and this activation was prevented by treatment with antioxidants such as Trolox and N-acetylcysteine. Our results show that BMMCs are able to release VEGF under hypoxic conditions through a tetanus toxin-sensitive mechanism, promoted by free radicals-dependent Fyn kinase activation.

  8. VEGF secretion during hypoxia depends on free radicals-induced Fyn kinase activity in mast cells

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Roman, Jonathan; Ibarra-Sanchez, Alfredo; Lamas, Monica [Departamento de Farmacobiologia, Centro de Investigacion y de Estudios Avanzados del IPN (Cinvestav, IPN) (Mexico); Gonzalez Espinosa, Claudia, E-mail: cgonzal@cinvestav.mx [Departamento de Farmacobiologia, Centro de Investigacion y de Estudios Avanzados del IPN (Cinvestav, IPN) (Mexico)

    2010-10-15

    Research highlights: {yields} Bone marrow-derived mast cells (BMMCs) secrete functional VEGF but do not degranulate after Cobalt chloride-induced hypoxia. {yields} CoCl{sub 2}-induced VEGF secretion in mast cells occurs by a Ca{sup 2+}-insensitive but brefeldin A and Tetanus toxin-sensitive mechanism. {yields} Trolox and N-acetylcysteine inhibit hypoxia-induced VEGF secretion but only Trolox inhibits Fc{epsilon}RI-dependent anaphylactic degranulation in mast cells. {yields} Src family kinase Fyn activation after free radical production is necessary for hypoxia-induced VEGF secretion in mast cells. -- Abstract: Mast cells (MC) have an important role in pathologic conditions such as asthma and chronic obstructive pulmonary disease (COPD), where hypoxia conduce to deleterious inflammatory response. MC contribute to hypoxia-induced angiogenesis producing factors such as vascular endothelial growth factor (VEGF), but the mechanisms behind the control of hypoxia-induced VEGF secretion in this cell type is poorly understood. We used the hypoxia-mimicking agent cobalt chloride (CoCl{sub 2}) to analyze VEGF secretion in murine bone marrow-derived mast cells (BMMCs). We found that CoCl{sub 2} promotes a sustained production of functional VEGF, able to induce proliferation of endothelial cells in vitro. CoCl{sub 2}-induced VEGF secretion was independent of calcium rise but dependent on tetanus toxin-sensitive vesicle-associated membrane proteins (VAMPs). VEGF exocytosis required free radicals formation and the activation of Src family kinases. Interestingly, an important deficiency on CoCl{sub 2}-induced VEGF secretion was observed in Fyn kinase-deficient BMMCs. Moreover, Fyn kinase was activated by CoCl{sub 2} in WT cells and this activation was prevented by treatment with antioxidants such as Trolox and N-acetylcysteine. Our results show that BMMCs are able to release VEGF under hypoxic conditions through a tetanus toxin-sensitive mechanism, promoted by free radicals

  9. Resveratrol induces growth arrest and apoptosis through activation of FOXO transcription factors in prostate cancer cells.

    Directory of Open Access Journals (Sweden)

    Qinghe Chen

    2010-12-01

    Full Text Available Resveratrol, a naturally occurring phytopolyphenol compound, has attracted extensive interest in recent years because of its diverse pharmacological characteristics. Although resveratrol possesses chemopreventive properties against several cancers, the molecular mechanisms by which it inhibits cell growth and induces apoptosis have not been clearly understood. The present study was carried out to examine whether PI3K/AKT/FOXO pathway mediates the biological effects of resveratrol.Resveratrol inhibited the phosphorylation of PI3K, AKT and mTOR. Resveratrol, PI3K inhibitors (LY294002 and Wortmannin and AKT inhibitor alone slightly induced apoptosis in LNCaP cells. These inhibitors further enhanced the apoptosis-inducing potential of resveratrol. Overexpression of wild-type PTEN slightly induced apoptosis. Wild type PTEN and PTEN-G129E enhanced resveratrol-induced apoptosis, whereas PTEN-G129R had no effect on proapoptotic effects of resveratrol. Furthermore, apoptosis-inducing potential of resveratrol was enhanced by dominant negative AKT, and inhibited by wild-type AKT and constitutively active AKT. Resveratrol has no effect on the expression of FKHR, FKHRL1 and AFX genes. The inhibition of FOXO phosphorylation by resveratrol resulted in its nuclear translocation, DNA binding and transcriptional activity. The inhibition of PI3K/AKT pathway induced FOXO transcriptional activity resulting in induction of Bim, TRAIL, p27/KIP1, DR4 and DR5, and inhibition of cyclin D1. Similarly, resveratrol-induced FOXO transcriptional activity was further enhanced when activation of PI3K/AKT pathway was blocked. Over-expression of phosphorylation deficient mutants of FOXO proteins (FOXO1-TM, FOXO3A-TM and FOXO4-TM induced FOXO transcriptional activity, which was further enhanced by resveratrol. Inhibition of FOXO transcription factors by shRNA blocked resveratrol-induced upregulation of Bim, TRAIL, DR4, DR5, p27/KIP1 and apoptosis, and inhibition of cyclin D1 by

  10. Oxidized LDL Induces Alternative Macrophage Phenotype through Activation of CD36 and PAFR

    Directory of Open Access Journals (Sweden)

    Francisco J. Rios

    2013-01-01

    Full Text Available OxLDL is recognized by macrophage scavenger receptors, including CD36; we have recently found that Platelet-Activating Factor Receptor (PAFR is also involved. Since PAFR in macrophages is associated with suppressor function, we examined the effect of oxLDL on macrophage phenotype. It was found that the presence of oxLDL during macrophage differentiation induced high mRNA levels to IL-10, mannose receptor, PPARγ and arginase-1 and low levels of IL-12 and iNOS. When human THP-1 macrophages were pre-treated with oxLDL then stimulated with LPS, the production of IL-10 and TGF-β significantly increased, whereas that of IL-6 and IL-8 decreased. In murine TG-elicited macrophages, this protocol significantly reduced NO, iNOS and COX2 expression. Thus, oxLDL induced macrophage differentiation and activation towards the alternatively activated M2-phenotype. In murine macrophages, oxLDL induced TGF-β, arginase-1 and IL-10 mRNA expression, which were significantly reduced by pre-treatment with PAFR antagonists (WEB and CV or with antibodies to CD36. The mRNA expression of IL-12, RANTES and CXCL2 were not affected. We showed that this profile of macrophage activation is dependent on the engagement of both CD36 and PAFR. We conclude that oxLDL induces alternative macrophage activation by mechanisms involving CD36 and PAFR.

  11. Visualization of the Differential Transition State Stabilization within the Active Site Environment

    Directory of Open Access Journals (Sweden)

    Jerzy Leszczynski

    2004-05-01

    Full Text Available Abstract: Increasing interest in the enzymatic reaction mechanisms and in the nature of catalytic effects in enzymes causes the need of appropriate visualization methods. A new interactive method to investigate catalytic effects using differential transition state stabilization approach (DTSS [1, 2] is presented. The catalytic properties of the active site of cytidine deaminase (E.C. 3.5.4.5 is visualized in the form of differential electrostatic properties. The visualization was implemented using scripting interface of VMD [3]. Cumulative Atomic Multipole Moments (CAMM [4,5,6] were utilized for efficient yet accurate evaluation of the electrostatic properties. The implementation is efficient enough for interactive presentation of catalytic effects in the active site of the enzyme due to transition state or substrate movement. This system of visualization of DTTS approach can be potentially used to validate hypotheses regarding the catalytic mechanism or to study binding properties of transition state analogues.

  12. Cisplatin-induced Casepase-3 activation in different tumor cells

    Science.gov (United States)

    Shi, Hua; Li, Xiao; Su, Ting; Zhang, Yu-Hai

    2008-12-01

    Apoptosis plays an essential role in normal organism development which is one of the main types of programmed cell death to help tissues maintain homeostasis. Defective apoptosis can result in cell accumulation and therefore effects on tumor pathogenesis, progression and therapy resistance. A family of proteins, known as caspases, is typically activated in the early stages of apoptosis. Therefore, studying the kinetics of activation of caspases induced by antitumor drugs can contribute to antitumor drug discovery and explanation of the molecular mechanisms. This paper detected the Caspase-3 activity induced by cisplatin in human adenoid cystic carcinoma cell line (ACC-M), human hepatocellular liver carcinoma cell line (HepG2) and human epithelial carcinoma cell line (Hela) with stably expressing ECFP-DEVDDsRed (CD3) probe, a fluorescent probe consisting of Enhanced Cyan Fluorescent Protein (ECFP), red fluorescent protein (DsRed) and a linker with a recognition site of Caspase-3, by using the capillary electrophoresis (CE) and fluorescence resonance energy transfer (FRET) imaging system. Under the same concentration of cisplatin, ACC-M cells responded the most rapidly, and then HepG2 cells and Hela cells, respectively, in the early 30 hours. Later, HepG2 cells represented acceleration in the Caspase-3 activation speed and reached full activation the earliest comparing to other two cell types. The results demonstrated that ACC-M cell is more sensitive than the other two cell types under the treatment of cisplatin.

  13. Macroscopic tunneling, decoherence and noise-induced activation

    Energy Technology Data Exchange (ETDEWEB)

    Lombardo, Fernando C; Monteoliva, Diana; Villar, Paula I [Departamento de Fisica Juan Jose Giambiagi, Facultad de Ciencias Exactas y Naturales, UBA, Ciudad Universitaria, Pabellon I, 1428 Buenos Aires (Argentina)

    2007-05-15

    We study the effects of the environment at zero temperature on tunneling in an open system described by a static double-well potential. We show that the evolution of the system in an initial Schroedinger cat state, can be summarized in terms of three main physical phenomena, namely decoherence, quantum tunneling and noise-induced activation. Using large-scale numerical simulations, we obtain a detailed picture of the main stages of the evolution and of the relevant dynamical processes.

  14. Human endogenous retrovirus expression is inversely related with the up-regulation of interferon-inducible genes in the skin of patients with lichen planus.

    Science.gov (United States)

    Nogueira, Marcelle Almeida de Sousa; Gavioli, Camila Fátima Biancardi; Pereira, Nátalli Zanete; de Carvalho, Gabriel Costa; Domingues, Rosana; Aoki, Valéria; Sato, Maria Notomi

    2015-04-01

    Lichen planus (LP) is a common inflammatory skin disease of unknown etiology. Reports of a common transactivation of quiescent human endogenous retroviruses (HERVs) support the connection of viruses to the disease. HERVs are ancient retroviral sequences in the human genome and their transcription is often deregulated in cancer and autoimmune diseases. We explored the transcriptional activity of HERV sequences as well as the antiviral restriction factor and interferon-inducible genes in the skin from LP patients and healthy control (HC) donors. The study included 13 skin biopsies from patients with LP and 12 controls. Real-time PCR assay identified significant decrease in the HERV-K gag and env mRNA expression levels in LP subjects, when compared to control group. The expressions of HERV-K18 and HERV-W env were also inhibited in the skin of LP patients. We observed a strong correlation between HERV-K gag with other HERV sequences, regardless the down-modulation of transcripts levels in LP group. In contrast, a significant up-regulation of the cytidine deaminase APOBEC 3G (apolipoprotein B mRNA-editing), and the GTPase MxA (Myxovirus resistance A) mRNA expression level was identified in the LP skin specimens. Other transcript expressions, such as the master regulator of type I interferon-dependent immune responses, STING (stimulator of interferon genes) and IRF-7 (interferon regulatory factor 7), IFN-β and the inflammassome NALP3, had increased levels in LP, when compared to HC group. Our study suggests that interferon-inducible factors, in addition to their role in innate immunity against exogenous pathogens, contribute to the immune control of HERVs. Evaluation of the balance between HERV and interferon-inducible factor expression could possibly contribute to surveillance of inflammatory/malignant status of skin diseases.

  15. Statins activate GATA-6 and induce differentiated vascular smooth muscle cells

    International Nuclear Information System (INIS)

    Wada, Hiromichi; Abe, Mitsuru; Ono, Koh; Morimoto, Tatsuya; Kawamura, Teruhisa; Takaya, Tomohide; Satoh, Noriko; Fujita, Masatoshi; Kita, Toru; Shimatsu, Akira; Hasegawa, Koji

    2008-01-01

    The beneficial effects of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) beyond cholesterol lowering involve their direct actions on vascular smooth muscle cells (VSMCs). However, the effects of statins on phenotypic modulation of VSMCs are unknown. We herein show that simvastatin (Sm) and atorvastatin (At) inhibited DNA synthesis in human aortic VSMCs dose-dependently, while cell toxicity was not observed below the concentration of 1 μM of Sm or 100 nM of At. Stimulating proliferative VSMCs with Sm or At induced the expression of SM-α-actin and SM-MHC, highly specific markers of differentiated phenotype. Sm up-regulated the binding activity of GATA-6 to SM-MHC GATA site and activated the transfected SM-MHC promoter in proliferative VSMCs, while mutating the GATA-6 binding site abolished this activation. Geranylgeranylpyrophosphate (10 μM), an inhibitor of Rho family proteins, abolished the statin-mediated induction of the differentiated phenotype in VSMCs. These findings suggest that statins activate GATA-6 and induce differentiated VSMCs

  16. Statins activate GATA-6 and induce differentiated vascular smooth muscle cells

    Energy Technology Data Exchange (ETDEWEB)

    Wada, Hiromichi [Division of Translational Research, National Hospital Organization Kyoto Medical Center, 1-1 Mukaihata-cho, Fukakusa, Fushimi-ku, Kyoto 612-8555 (Japan); Abe, Mitsuru; Ono, Koh [Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Kyoto (Japan); Morimoto, Tatsuya; Kawamura, Teruhisa; Takaya, Tomohide [Division of Translational Research, National Hospital Organization Kyoto Medical Center, 1-1 Mukaihata-cho, Fukakusa, Fushimi-ku, Kyoto 612-8555 (Japan); Satoh, Noriko [Division of Metabolic Research, National Hospital Organization Kyoto Medical Center, Kyoto (Japan); Fujita, Masatoshi [Department of Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto (Japan); Kita, Toru [Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Kyoto (Japan); Shimatsu, Akira [Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Kyoto (Japan); Hasegawa, Koji [Division of Translational Research, National Hospital Organization Kyoto Medical Center, 1-1 Mukaihata-cho, Fukakusa, Fushimi-ku, Kyoto 612-8555 (Japan)

    2008-10-03

    The beneficial effects of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) beyond cholesterol lowering involve their direct actions on vascular smooth muscle cells (VSMCs). However, the effects of statins on phenotypic modulation of VSMCs are unknown. We herein show that simvastatin (Sm) and atorvastatin (At) inhibited DNA synthesis in human aortic VSMCs dose-dependently, while cell toxicity was not observed below the concentration of 1 {mu}M of Sm or 100 nM of At. Stimulating proliferative VSMCs with Sm or At induced the expression of SM-{alpha}-actin and SM-MHC, highly specific markers of differentiated phenotype. Sm up-regulated the binding activity of GATA-6 to SM-MHC GATA site and activated the transfected SM-MHC promoter in proliferative VSMCs, while mutating the GATA-6 binding site abolished this activation. Geranylgeranylpyrophosphate (10 {mu}M), an inhibitor of Rho family proteins, abolished the statin-mediated induction of the differentiated phenotype in VSMCs. These findings suggest that statins activate GATA-6 and induce differentiated VSMCs.

  17. Activation of PPARα by Wy-14643 ameliorates systemic lipopolysaccharide-induced acute lung injury

    International Nuclear Information System (INIS)

    Yoo, Seong Ho; Abdelmegeed, Mohamed A.; Song, Byoung-Joon

    2013-01-01

    Highlights: •Activation of PPARα attenuated LPS-mediated acute lung injury. •Pretreatment with Wy-14643 decreased the levels of IFN-γ and IL-6 in ALI. •Nitrosative stress and lipid peroxidation were downregulated by PPARα activation. •PPARα agonists may be potential therapeutic targets for acute lung injury. -- Abstract: Acute lung injury (ALI) is a major cause of mortality and morbidity worldwide. The activation of peroxisome proliferator-activated receptor-α (PPARα) by its ligands, which include Wy-14643, has been implicated as a potential anti-inflammatory therapy. To address the beneficial efficacy of Wy-14643 for ALI along with systemic inflammation, the in vivo role of PPARα activation was investigated in a mouse model of lipopolysaccharide (LPS)-induced ALI. Using age-matched Ppara-null and wild-type mice, we demonstrate that the activation of PPARα by Wy-14643 attenuated LPS-mediated ALI. This was evidenced histologically by the significant alleviation of inflammatory manifestations and apoptosis observed in the lung tissues of wild-type mice, but not in the corresponding Ppara-null mice. This protective effect probably resulted from the inhibition of LPS-induced increases in pro-inflammatory cytokines and nitroxidative stress levels. These results suggest that the pharmacological activation of PPARα might have a therapeutic effect on LPS-induced ALI

  18. Activation of PPARα by Wy-14643 ameliorates systemic lipopolysaccharide-induced acute lung injury

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Seong Ho, E-mail: yoosh@snu.ac.kr [Seoul National University Hospital, Biomedical Research Institute and Institute of Forensic Medicine, Seoul National University College of Medicine, Seoul (Korea, Republic of); Abdelmegeed, Mohamed A. [Laboratory of Membrane Biochemistry and Biophysics, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD (United States); Song, Byoung-Joon, E-mail: bj.song@nih.gov [Laboratory of Membrane Biochemistry and Biophysics, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD (United States)

    2013-07-05

    Highlights: •Activation of PPARα attenuated LPS-mediated acute lung injury. •Pretreatment with Wy-14643 decreased the levels of IFN-γ and IL-6 in ALI. •Nitrosative stress and lipid peroxidation were downregulated by PPARα activation. •PPARα agonists may be potential therapeutic targets for acute lung injury. -- Abstract: Acute lung injury (ALI) is a major cause of mortality and morbidity worldwide. The activation of peroxisome proliferator-activated receptor-α (PPARα) by its ligands, which include Wy-14643, has been implicated as a potential anti-inflammatory therapy. To address the beneficial efficacy of Wy-14643 for ALI along with systemic inflammation, the in vivo role of PPARα activation was investigated in a mouse model of lipopolysaccharide (LPS)-induced ALI. Using age-matched Ppara-null and wild-type mice, we demonstrate that the activation of PPARα by Wy-14643 attenuated LPS-mediated ALI. This was evidenced histologically by the significant alleviation of inflammatory manifestations and apoptosis observed in the lung tissues of wild-type mice, but not in the corresponding Ppara-null mice. This protective effect probably resulted from the inhibition of LPS-induced increases in pro-inflammatory cytokines and nitroxidative stress levels. These results suggest that the pharmacological activation of PPARα might have a therapeutic effect on LPS-induced ALI.

  19. AMP-activated protein kinase induces actin cytoskeleton reorganization in epithelial cells

    International Nuclear Information System (INIS)

    Miranda, Lisa; Carpentier, Sarah; Platek, Anna; Hussain, Nusrat; Gueuning, Marie-Agnes; Vertommen, Didier; Ozkan, Yurda; Sid, Brice; Hue, Louis; Courtoy, Pierre J.; Rider, Mark H.; Horman, Sandrine

    2010-01-01

    AMP-activated protein kinase (AMPK), a known regulator of cellular and systemic energy balance, is now recognized to control cell division, cell polarity and cell migration, all of which depend on the actin cytoskeleton. Here we report the effects of A769662, a pharmacological activator of AMPK, on cytoskeletal organization and signalling in epithelial Madin-Darby canine kidney (MDCK) cells. We show that AMPK activation induced shortening or radiation of stress fibers, uncoupling from paxillin and predominance of cortical F-actin. In parallel, Rho-kinase downstream targets, namely myosin regulatory light chain and cofilin, were phosphorylated. These effects resembled the morphological changes in MDCK cells exposed to hyperosmotic shock, which led to Ca 2+ -dependent AMPK activation via calmodulin-dependent protein kinase kinase-β(CaMKKβ), a known upstream kinase of AMPK. Indeed, hypertonicity-induced AMPK activation was markedly reduced by the STO-609 CaMKKβ inhibitor, as was the increase in MLC and cofilin phosphorylation. We suggest that AMPK links osmotic stress to the reorganization of the actin cytoskeleton.

  20. Uric Acid Induces Renal Inflammation via Activating Tubular NF-κB Signaling Pathway

    Science.gov (United States)

    Zhou, Yang; Fang, Li; Jiang, Lei; Wen, Ping; Cao, Hongdi; He, Weichun; Dai, Chunsun; Yang, Junwei

    2012-01-01

    Inflammation is a pathologic feature of hyperuricemia in clinical settings. However, the underlying mechanism remains unknown. Here, infiltration of T cells and macrophages were significantly increased in hyperuricemia mice kidneys. This infiltration of inflammatory cells was accompanied by an up-regulation of TNF-α, MCP-1 and RANTES expression. Further, infiltration was largely located in tubular interstitial spaces, suggesting a role for tubular cells in hyperuricemia-induced inflammation. In cultured tubular epithelial cells (NRK-52E), uric acid, probably transported via urate transporter, induced TNF-α, MCP-1 and RANTES mRNA as well as RANTES protein expression. Culture media of NRK-52E cells incubated with uric acid showed a chemo-attractive ability to recruit macrophage. Moreover uric acid activated NF-κB signaling. The uric acid-induced up-regulation of RANTES was blocked by SN 50, a specific NF-κB inhibitor. Activation of NF-κB signaling was also observed in tubule of hyperuricemia mice. These results suggest that uric acid induces renal inflammation via activation of NF-κB signaling. PMID:22761883

  1. Cyclosporine Induces Endothelial Cell Release of Complement-Activating Microparticles

    Science.gov (United States)

    Renner, Brandon; Klawitter, Jelena; Goldberg, Ryan; McCullough, James W.; Ferreira, Viviana P.; Cooper, James E.; Christians, Uwe

    2013-01-01

    Defective control of the alternative pathway of complement is an important risk factor for several renal diseases, including atypical hemolytic uremic syndrome. Infections, drugs, pregnancy, and hemodynamic insults can trigger episodes of atypical hemolytic uremic syndrome in susceptible patients. Although the mechanisms linking these clinical events with disease flares are unknown, recent work has revealed that each of these clinical conditions causes cells to release microparticles. We hypothesized that microparticles released from injured endothelial cells promote intrarenal complement activation. Calcineurin inhibitors cause vascular and renal injury and can trigger hemolytic uremic syndrome. Here, we show that endothelial cells exposed to cyclosporine in vitro and in vivo release microparticles that activate the alternative pathway of complement. Cyclosporine-induced microparticles caused injury to bystander endothelial cells and are associated with complement-mediated injury of the kidneys and vasculature in cyclosporine-treated mice. Cyclosporine-induced microparticles did not bind factor H, an alternative pathway regulatory protein present in plasma, explaining their complement-activating phenotype. Finally, we found that in renal transplant patients, the number of endothelial microparticles in plasma increases 2 weeks after starting tacrolimus, and treatment with tacrolimus associated with increased C3 deposition on endothelial microparticles in the plasma of some patients. These results suggest that injury-associated release of endothelial microparticles is an important mechanism by which systemic insults trigger intravascular complement activation and complement-dependent renal diseases. PMID:24092930

  2. Lipocalin-2 induces NLRP3 inflammasome activation via HMGB1 induced TLR4 signaling in heart tissue of mice under pressure overload challenge.

    Science.gov (United States)

    Song, Erfei; Jahng, James Ws; Chong, Lisa P; Sung, Hye K; Han, Meng; Luo, Cuiting; Wu, Donghai; Boo, Stellar; Hinz, Boris; Cooper, Matthew A; Robertson, Avril Ab; Berger, Thorsten; Mak, Tak W; George, Isaac; Schulze, P Christian; Wang, Yu; Xu, Aimin; Sweeney, Gary

    2017-01-01

    Lipocalin-2 (also known as NGAL) levels are elevated in obesity and diabetes yet relatively little is known regarding effects on the heart. We induced pressure overload (PO) in mice and found that lipocalin-2 knockout (LKO) mice exhibited less PO-induced autophagy and NLRP3 inflammasome activation than Wt. PO-induced mitochondrial damage was reduced and autophagic flux greater in LKO mice, which correlated with less cardiac dysfunction. All of these observations were negated upon adenoviral-mediated restoration of normal lipocalin-2 levels in LKO. Studies in primary cardiac fibroblasts indicated that lipocalin-2 enhanced priming and activation of NLRP3-inflammasome, detected by increased IL-1β, IL-18 and Caspase-1 activation. This was attenuated in cells isolated from NLRP3-deficient mice or upon pharmacological inhibition of NLRP3. Furthermore, lipocalin-2 induced release of HMGB1 from cells and NLRP3-inflammasome activation was attenuated by TLR4 inhibition. We also found evidence of increased inflammasome activation and reduced autophagy in cardiac biopsy samples from heart failure patients. Overall, this study provides new mechanistic insight on the detrimental role of lipocalin-2 in the development of cardiac dysfunction.

  3. Metformin induces differentiation in acute promyelocytic leukemia by activating the MEK/ERK signaling pathway

    International Nuclear Information System (INIS)

    Huai, Lei; Wang, Cuicui; Zhang, Cuiping; Li, Qihui; Chen, Yirui; Jia, Yujiao; Li, Yan; Xing, Haiyan; Tian, Zheng; Rao, Qing; Wang, Min; Wang, Jianxiang

    2012-01-01

    Highlights: ► Metformin induces differentiation in NB4 and primary APL cells. ► Metformin induces activation of the MEK/ERK signaling pathway in APL cells. ► Metformin synergizes with ATRA to trigger maturation of NB4 and primary APL cells. ► Metformin induces the relocalization and degradation of the PML-RARα fusion protein. ► The study may be applicable for new differentiation therapy in cancer treatment. -- Abstract: Recent studies have shown that metformin, a widely used antidiabetic agent, may reduce the risk of cancer development. In this study, we investigated the antitumoral effect of metformin on both acute myeloid leukemia (AML) and acute promyelocytic leukemia (APL) cells. Metformin induced apoptosis with partial differentiation in an APL cell line, NB4, but only displayed a proapoptotic effect on several non-M3 AML cell lines. Further analysis revealed that a strong synergistic effect existed between metformin and all-trans retinoic acid (ATRA) during APL cell maturation and that metformin induced the hyperphosphorylation of extracellular signal-regulated kinase (ERK) in APL cells. U0126, a specific MEK/ERK activation inhibitor, abrogated metformin-induced differentiation. Finally, we found that metformin induced the degradation of the oncoproteins PML-RARα and c-Myc and activated caspase-3. In conclusion, these results suggest that metformin treatment may contribute to the enhancement of ATRA-induced differentiation in APL, which may deepen the understanding of APL maturation and thus provide insight for new therapy strategies.

  4. Human retinal pigment epithelial cell-induced apoptosis in activated T cells

    DEFF Research Database (Denmark)

    Jørgensen, A; Wiencke, A K; la Cour, M

    1998-01-01

    PURPOSE: The immune privilege of the eye has been thought to be dependent on physical barriers and absence of lymphatic vessels. However, the immune privilege may also involve active immunologic processes, as recent studies have indicated. The purpose of the present study was to investigate whether...... human retinal pigment epithelial (RPE) cells can induce apoptosis in activated T cells. METHODS: Fas ligand (FasL) expression was detected by flow cytometry and immunohistochemistry. Cultured RPE cells were cocultured with T-cell lines and peripheral blood lymphocytes for 6 hours to 2 days. Induction...... of apoptosis was detected by 7-amino-actinomycin D and annexin V staining. RESULTS: Retinal pigment epithelial cells expressed FasL and induced apoptosis in activated Fas+ T cells. Blocking of Fas-FasL interaction with antibody strongly inhibited RPE-mediated T-cell apoptosis. Retinal pigment epithelial cells...

  5. YB-1 overexpression promotes a TGF-β1-induced epithelial–mesenchymal transition via Akt activation

    International Nuclear Information System (INIS)

    Ha, Bin; Lee, Eun Byul; Cui, Jun; Kim, Yosup; Jang, Ho Hee

    2015-01-01

    The Y-box binding protein-1 (YB-1) is a transcription/translation regulatory protein, and the expression thereof is associated with cancer aggressiveness. In the present study, we explored the regulatory effects of YB-1 during the transforming growth factor-β1 (TGF-β1)-induced epithelial-to-mesenchymal transition (EMT) in lung adenocarcinoma cells. Downregulation of YB-1 increased E-cadherin promoter activity, and upregulation of YB-1 decreased promoter activity, suggesting that the YB-1 level may be correlated with the EMT. TGF-β1 induced YB-1 expression, and TGF-β1 translocated cytosolic YB-1 into the nucleus. YB-1 overexpression promoted TGF-β1-induced downregulation of epithelial markers, upregulation of mesenchymal markers, and cell migration. Moreover, YB-1 overexpression enhanced the expression of E-cadherin transcriptional repressors via TGF-β1-induced Akt activation. Our findings afford new insights into the role played by YB-1 in the TGF-β1 signaling pathway. - Highlights: • YB-1 regulates E-cadherin expression in A549 cells. • TGF-β1 induces upregulating and nuclear localization of YB-1. • YB-1 overexpression accelerates TGF-β1-induced EMT and cell migration. • YB-1 regulates Snail and Slug expression via Akt activation

  6. δ-Tocopherol inhibits receptor tyrosine kinase-induced AKT activation in prostate cancer cells.

    Science.gov (United States)

    Wang, Hong; Hong, Jungil; Yang, Chung S

    2016-11-01

    The cancer preventive activity of vitamin E is suggested by epidemiological studies and supported by animal studies with vitamin E forms, γ-tocopherol and δ-tocopherol (δ-T). Several recent large-scale cancer prevention trials with high dose of α-tocopherol, however, yielded disappointing results. Whether vitamin E prevents or promotes cancer is a serious concern. A better understanding of the molecular mechanisms of action of the different forms of tocopherols would enhance our understanding of this topic. In this study, we demonstrated that δ-T was the most effective tocopherol form in inhibiting prostate cancer cell growth, by inducing cell cycle arrest and apoptosis. By profiling the effects of δ-T on the cell signaling using the phospho-kinase array, we found that the most inhibited target was the phosphorylation of AKT on T308. Further study on the activation of AKT by EGFR and IGFR revealed that δ-T attenuated the EGF/IGF-induced activation of AKT (via the phosphorylation of AKT on T308 induced by the activation of PIK3). Expression of dominant active PIK3 and AKT in prostate cancer cell line DU145 in which PIK3, AKT, and PTEN are wild type caused the cells to be reflectory to the inhibition of δ-T, supporting that δ-T inhibits the PIK3-mediated activation of AKT. Our data also suggest that δ-T interferes with the EGF-induced EGFR internalization, which leads to the inhibition of the receptor tyrosine kinase-dependent activation of AKT. In summary, our results revealed a novel mechanism of δ-T in inhibiting prostate cancer cell growth, supporting the cancer preventive activity δ-T. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  7. Compounds from Cynomorium songaricum with Estrogenic and Androgenic Activities Suppress the Oestrogen/Androgen-Induced BPH Process.

    Science.gov (United States)

    Wang, Xueni; Tao, Rui; Yang, Jing; Miao, Lin; Wang, Yu; Munyangaju, Jose Edouard; Wichai, Nuttapong; Wang, Hong; Zhu, Yan; Liu, Erwei; Chang, Yanxu; Gao, Xiumei

    2017-01-01

    To investigate the phytoestrogenic and phytoandrogenic activities of compounds isolated from CS and uncover the role of CS in prevention of oestrogen/androgen-induced BPH. Cells were treated with CS compounds, and immunofluorescence assay was performed to detect the nuclear translocation of ER α or AR in MCF-7 or LNCaP cells; luciferase reporter assay was performed to detect ERs or AR transcriptional activity in HeLa or AD293 cells; MTT assay was performed to detect the cell proliferation of MCF-7 or LNCaP cells. Oestrogen/androgen-induced BPH model was established in rat and the anti-BPH, anti-estrogenic, and anti-androgenic activities of CS in vivo were further investigated. The nuclear translocation of ER α was stimulated by nine CS compounds, three of which also stimulated AR translocation. The transcriptional activities of ER α and ER β were induced by five compounds, within which only ECG induced AR transcriptional activity as well. Besides, ECG stimulated the proliferation of both MCF-7 cells and LNCaP cells. CS extract suppressed oestrogen/androgen-induced BPH progress in vivo by downregulation of E2 and T level in serum and alteration of the expressions of ER α , ER β , and AR in the prostate. Our data demonstrates that compounds from CS exhibit phytoestrogenic and phytoandrogenic activities, which may contribute to inhibiting the oestrogen/androgen-induced BPH development.

  8. Stat1 activation attenuates IL-6 induced Stat3 activity but does not alter apoptosis sensitivity in multiple myeloma

    Directory of Open Access Journals (Sweden)

    Dimberg Lina Y

    2012-07-01

    Full Text Available Abstract Background Multiple myeloma (MM is at present an incurable malignancy, characterized by apoptosis-resistant tumor cells. Interferon (IFN treatment sensitizes MM cells to Fas-induced apoptosis and is associated with an increased activation of Signal transducer and activator of transcription (Stat1. The role of Stat1 in MM has not been elucidated, but Stat1 has in several studies been ascribed a pro-apoptotic role. Conversely, IL-6 induction of Stat3 is known to confer resistance to apoptosis in MM. Methods To delineate the role of Stat1 in IFN mediated sensitization to apoptosis, sub-lines of the U-266-1970 MM cell line with a stable expression of the active mutant Stat1C were utilized. The influence of Stat1C constitutive transcriptional activation on endogenous Stat3 expression and activation, and the expression of apoptosis-related genes were analyzed. To determine whether Stat1 alone would be an important determinant in sensitizing MM cells to apoptosis, the U-266-1970-Stat1C cell line and control cells were exposed to high throughput compound screening (HTS. Results To explore the role of Stat1 in IFN mediated apoptosis sensitization of MM, we established sublines of the MM cell line U-266-1970 constitutively expressing the active mutant Stat1C. We found that constitutive nuclear localization and transcriptional activity of Stat1 was associated with an attenuation of IL-6-induced Stat3 activation and up-regulation of mRNA for the pro-apoptotic Bcl-2 protein family genes Harakiri, the short form of Mcl-1 and Noxa. However, Stat1 activation alone was not sufficient to sensitize cells to Fas-induced apoptosis. In a screening of > 3000 compounds including bortezomib, dexamethasone, etoposide, suberoylanilide hydroxamic acid (SAHA, geldanamycin (17-AAG, doxorubicin and thalidomide, we found that the drug response and IC50 in cells constitutively expressing active Stat1 was mainly unaltered. Conclusion We conclude that Stat1 alters IL-6

  9. Stat1 activation attenuates IL-6 induced Stat3 activity but does not alter apoptosis sensitivity in multiple myeloma

    International Nuclear Information System (INIS)

    Dimberg, Lina Y; Nilsson, Kenneth; Öberg, Fredrik; Wiklund, Helena Jernberg; Dimberg, Anna; Ivarsson, Karolina; Fryknäs, Mårten; Rickardson, Linda; Tobin, Gerard; Ekman, Simon; Larsson, Rolf; Gullberg, Urban

    2012-01-01

    Multiple myeloma (MM) is at present an incurable malignancy, characterized by apoptosis-resistant tumor cells. Interferon (IFN) treatment sensitizes MM cells to Fas-induced apoptosis and is associated with an increased activation of Signal transducer and activator of transcription (Stat)1. The role of Stat1 in MM has not been elucidated, but Stat1 has in several studies been ascribed a pro-apoptotic role. Conversely, IL-6 induction of Stat3 is known to confer resistance to apoptosis in MM. To delineate the role of Stat1 in IFN mediated sensitization to apoptosis, sub-lines of the U-266-1970 MM cell line with a stable expression of the active mutant Stat1C were utilized. The influence of Stat1C constitutive transcriptional activation on endogenous Stat3 expression and activation, and the expression of apoptosis-related genes were analyzed. To determine whether Stat1 alone would be an important determinant in sensitizing MM cells to apoptosis, the U-266-1970-Stat1C cell line and control cells were exposed to high throughput compound screening (HTS). To explore the role of Stat1 in IFN mediated apoptosis sensitization of MM, we established sublines of the MM cell line U-266-1970 constitutively expressing the active mutant Stat1C. We found that constitutive nuclear localization and transcriptional activity of Stat1 was associated with an attenuation of IL-6-induced Stat3 activation and up-regulation of mRNA for the pro-apoptotic Bcl-2 protein family genes Harakiri, the short form of Mcl-1 and Noxa. However, Stat1 activation alone was not sufficient to sensitize cells to Fas-induced apoptosis. In a screening of > 3000 compounds including bortezomib, dexamethasone, etoposide, suberoylanilide hydroxamic acid (SAHA), geldanamycin (17-AAG), doxorubicin and thalidomide, we found that the drug response and IC50 in cells constitutively expressing active Stat1 was mainly unaltered. We conclude that Stat1 alters IL-6 induced Stat3 activity and the expression of pro

  10. Small molecule antagonism of oxysterol-induced Epstein-Barr virus induced gene 2 (EBI2) activation

    DEFF Research Database (Denmark)

    Benned-Jensen, Tau; Madsen, Christian M; Arfelt, Kristine N

    2013-01-01

    The Epstein-Barr virus induced gene 2 (EBI2) was recently identified as the first oxysterol-activated 7TM receptor. EBI2 is essential for B cell trafficking within lymphoid tissues and thus the humoral immune response in general. Here we characterize the antagonism of the non-peptide molecule GSK...

  11. PARP-1 and PARP-2 activity in cancer-induced cachexia: potential therapeutic implications.

    Science.gov (United States)

    Barreiro, Esther; Gea, Joaquim

    2018-01-26

    Skeletal muscle dysfunction and mass loss is a characteristic feature in patients with chronic diseases including cancer and acute conditions such as critical illness. Maintenance of an adequate muscle mass is crucial for the patients' prognosis irrespective of the underlying condition. Moreover, aging-related sarcopenia may further aggravate the muscle wasting process associated with chronic diseases and cancer. Poly(adenosine diphosphate-ribose) polymerase (PARP) activation has been demonstrated to contribute to the pathophysiology of muscle mass loss and dysfunction in animal models of cancer-induced cachexia. Genetic inhibition of PARP activity attenuated the deleterious effects seen on depleted muscles in mouse models of oncologic cachexia. In the present minireview the mechanisms whereby PARP activity inhibition may improve muscle mass and performance in models of cancer-induced cachexia are discussed. Specifically, the beneficial effects of inhibition of PARP activity on attenuation of increased oxidative stress, protein catabolism, poor muscle anabolism and mitochondrial content and epigenetic modulation of muscle phenotype are reviewed in this article. Finally, the potential therapeutic strategies of pharmacological PARP activity inhibition for the treatment of cancer-induced cachexia are also being described in this review.

  12. Brain catalase activity inhibition as well as opioid receptor antagonism increases ethanol-induced HPA axis activation.

    Science.gov (United States)

    Pastor, Raúl; Sanchis-Segura, Carles; Aragon, Carlos M G

    2004-12-01

    Growing evidence indicates that brain catalase activity is involved in the psychopharmacological actions of ethanol. Recent data suggest that participation of this enzymatic system in some ethanol effects could be mediated by the endogenous opioid system. The present study assessed whether brain catalase has a role in ethanol-induced activation of the HPA axis, a neuroendocrine system modulated by the endogenous opioid neurotransmission. Swiss male mice received an intraperitoneal injection of the catalase inhibitor 3-amino-1,2,4-triazole (AT; 0-1 g/kg), and 0 to 20 hr after this administration, animals received an ethanol (0-4 g/kg; intraperitoneally) challenge. Thirty, 60, or 120 min after ethanol administration, plasma corticosterone levels were determined immunoenzymatically. In addition, we tested the effects of 45 mg/kg of cyanamide (another catalase inhibitor) and 0 to 2 mg/kg of naltrexone (nonselective opioid receptor antagonist) on ethanol-induced enhancement in plasma corticosterone values. The present study revealed that AT boosts ethanol-induced increase in plasma corticosterone levels in a dose- and time-dependent manner. However, it did not affect corticosterone values when measured after administration of saline, cocaine (4 mg/kg, intraperitoneally), or morphine (30 mg/kg, intraperitoneally). The catalase inhibitor cyanamide (45 mg/kg, intraperitoneally) also increased ethanol-related plasma corticosterone levels. These effects of AT and cyanamide on ethanol-induced corticosterone values were observed under treatment conditions that decreased significantly brain catalase activity. Indeed, a significant correlation between effects of catalase manipulations on both variables was found. Finally, we found that the administration of naltrexone enhanced the levels of plasma corticosterone after the administration of saline or ethanol. This study shows that the inhibition of brain catalase increases ethanol-induced plasma corticosterone levels. Results are

  13. Effect of montelukast on platelet activating factor- and tachykinin induced mucus secretion in the rat

    Directory of Open Access Journals (Sweden)

    Groneberg David A

    2008-02-01

    Full Text Available Abstract Background Platelet activating factor and tachykinins (substance P, neurokinin A, neurokinin B are important mediators contributing to increased airway secretion in the context of different types of respiratory diseases including acute and chronic asthma. Leukotriene receptor antagonists are recommended as add-on therapy for this disease. The cys-leukotriene-1 receptor antagonist montelukast has been used in clinical asthma therapy during the last years. Besides its inhibitory action on bronchoconstriction, only little is known about its effects on airway secretions. Therefore, the aim of this study was to evaluate the effects of montelukast on platelet activating factor- and tachykinin induced tracheal secretory activity. Methods The effects of montelukast on platelet activating factor- and tachykinin induced tracheal secretory activity in the rat were assessed by quantification of secreted 35SO4 labelled mucus macromolecules using the modified Ussing chamber technique. Results Platelet activating factor potently stimulated airway secretion, which was completely inhibited by the platelet activating factor receptor antagonist WEB 2086 and montelukast. In contrast, montelukast had no effect on tachykinin induced tracheal secretory activity. Conclusion Cys-leukotriene-1 receptor antagonism by montelukast reverses the secretagogue properties of platelet activating factor to the same degree as the specific platelet activating factor antagonist WEB 2086 but has no influence on treacheal secretion elicited by tachykinins. These results suggest a role of montelukast in the signal transduction pathway of platelet activating factor induced secretory activity of the airways and may further explain the beneficial properties of cys-leukotriene-1 receptor antagonists.

  14. Glutamate decarboxylase activity in rat brain during experimental epileptic seizures induced by pilocarpine

    Energy Technology Data Exchange (ETDEWEB)

    Netopilova, M; Drsata, J [Department of Biochemical Sciences, Faculty of Pharmacy, Charles University, 50005 Hradec Kralove (Czech Republic); Haugvicova, R; Kubova, H; Mares, P [Institute of Physiology, Czech Academy of Sciences, 14220 Prague (Czech Republic)

    1998-07-01

    Glutamate decarboxylase (GAD) activity was studied rat brain parts in a pilocarpine model of epileptic seizures. An increased enzyme activity was found in hippocampus a cerebellum during the acute phase of seizures, while the cortex and cerebellum showed increased GAD activity in the chronic phase of the process. Systematic administration of pilocarpine to rats induces status epilepticus. The aim of this research was to find out if seizures induced by pilocarpine are connected changes in glutamate decarboxylase activity, the enzyme that catalyzes synthesis of inhibitory neurotransmitter GABA. GAD was assayed by means of radiometric method using {sup 14}C-carboxyl-labelled glutamate and measurement of {sup 14}CO{sub 2} radioactivity. Obtained results suggest that pilocarpine seizures are connected with changes of GAD activity in individual parts of rat brain. (authors)

  15. Glutamate decarboxylase activity in rat brain during experimental epileptic seizures induced by pilocarpine

    International Nuclear Information System (INIS)

    Netopilova, M.; Drsata, J.; Haugvicova, R.; Kubova, H.; Mares, P.

    1998-01-01

    Glutamate decarboxylase (GAD) activity was studied rat brain parts in a pilocarpine model of epileptic seizures. An increased enzyme activity was found in hippocampus a cerebellum during the acute phase of seizures, while the cortex and cerebellum showed increased GAD activity in the chronic phase of the process. Systematic administration of pilocarpine to rats induces status epilepticus. The aim of this research was to find out if seizures induced by pilocarpine are connected changes in glutamate decarboxylase activity, the enzyme that catalyzes synthesis of inhibitory neurotransmitter GABA. GAD was assayed by means of radiometric method using 14 C-carboxyl-labelled glutamate and measurement of 14 CO 2 radioactivity. Obtained results suggest that pilocarpine seizures are connected with changes of GAD activity in individual parts of rat brain. (authors)

  16. Differential programming of B cells in AID deficient mice.

    Directory of Open Access Journals (Sweden)

    Marc A Hogenbirk

    Full Text Available The Aicda locus encodes the activation induced cytidine deaminase (AID and is highly expressed in germinal center (GC B cells to initiate somatic hypermutation (SHM and class switch recombination (CSR of immunoglobulin (Ig genes. Besides these Ig specific activities in B cells, AID has been implicated in active DNA demethylation in non-B cell systems. We here determined a potential role of AID as an epigenetic eraser and transcriptional regulator in B cells. RNA-Seq on different B cell subsets revealed that Aicda(-/- B cells are developmentally affected. However as shown by RNA-Seq, MethylCap-Seq, and SNP analysis these transcriptome alterations may not relate to AID, but alternatively to a CBA mouse strain derived region around the targeted Aicda locus. These unexpected confounding parameters provide alternative, AID-independent interpretations on genotype-phenotype correlations previously reported in numerous studies on AID using the Aicda(-/- mouse strain.

  17. Cetuximab-Induced MET Activation Acts as a Novel Resistance Mechanism in Colon Cancer Cells

    Directory of Open Access Journals (Sweden)

    Na Song

    2014-04-01

    Full Text Available Aberrant MET expression and hepatocyte growth factor (HGF signaling are implicated in promoting resistance to targeted agents; however, the induced MET activation by epidermal growth factor receptor (EGFR inhibitors mediating resistance to targeted therapy remains elusive. In this study, we identified that cetuximab-induced MET activation contributed to cetuximab resistance in Caco-2 colon cancer cells. MET inhibition or knockdown sensitized Caco-2 cells to cetuximab-mediated growth inhibition. Additionally, SRC activation promoted cetuximab resistance by interacting with MET. Pretreatment with SRC inhibitors abolished cetuximab-mediated MET activation and rendered Caco-2 cells sensitive to cetuximab. Notably, cetuximab induced MET/SRC/EGFR complex formation. MET inhibitor or SRC inhibitor suppressed phosphorylation of MET and SRC in the complex, and MET inhibitor singly led to disruption of complex formation. These results implicate alternative targeting of MET or SRC as rational strategies for reversing cetuximab resistance in colon cancer.

  18. Kinetics of micronucleus induction and cytotoxicity caused by distinct antineoplastics and alkylating agents in vivo.

    Science.gov (United States)

    Morales-Ramírez, Pedro; Vallarino-Kelly, Teresita; Cruz-Vallejo, Virginia

    2014-01-30

    This mini-review aims to compare the differences in the kinetics of the induction of micronucleated polychromatic erythrocytes (MN-PCE) and cytotoxicity by distinct antineoplastic and genotoxic agents in murine peripheral blood in vivo and to correlate these kinetics with the underlying processes. Comparisons were carried out using our previously obtained data with nominal doses causing similar levels of cytotoxicity, as measured in terms reduction of PCE. The aneuploidogens caused the most rapid induction of MN-PCEs and had the highest rates of cytotoxicity and genotoxicity. The promutagens cyclophosphamide and dimethylnitrosamine showed the most delayed responses and had the lowest genotoxic and cytotoxic efficiencies. DNA crosslinking agents had a similar delay of 4-5 h, greater than those of aneuploidogens, but differed in their cytotoxic and genotoxic efficiencies. Methylnitrosourea and 5-aza-cytidine caused greater delays than crosslinking agents. These delays can be due to the methylnitrosourea-mediated induction of formation of mono alkyl adducts which are interpreted as mismatches during DNA duplication, whereas 5-aza-cytidine requires incorporation into the DNA to induce breakage. This review allows us to conclude that the requirement for metabolic activation and the mechanisms of DNA breakage and of micronucleus induction are the main factors that affect the time of maximal MN-PCE induction. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  19. Hypocapnia induces caspase-3 activation and increases Abeta production.

    Science.gov (United States)

    Xie, Zhongcong; Moir, Robert D; Romano, Donna M; Tesco, Giuseppina; Kovacs, Dora M; Tanzi, Rudolph E

    2004-01-01

    At least half of all cases of early onset (<60) familial Alzheimer's disease (FAD) are caused by any of over 150 mutations in three genes: the amyloid precursor protein (APP), presenilin 1 (PS1), and presenilin 2 (PS2). Mutant forms of PS1 have been shown to sensitize cells to apoptotic cell death. We investigated the effects of hypocapnia, a risk factor for both cognitive and neurodevelopment deficits, on caspase-3 activation, apoptosis, and amyloid beta-protein (Abeta) production, and assessed the influence of the PS1Delta9 FAD mutation on these effects. For this purpose, we exposed stably transfected H4 human neuroglioma cells to conditions consistent with hypocapnia (PCO2<40 mm Hg) and hypocapnia plus hypoxia (PO2<21%). Hypocapnia (20 mm Hg CO2 for 6 h) induced caspase-3 activation and apoptosis; the PS1Delta9 FAD mutation significantly potentiated these effects. Moreover, the combination of hypocapnia (20 mm Hg CO2) and hypoxia (5%O2) induced caspase-3 activation and apoptosis in a synergistic manner. Hypocapnia (5 and 20 mm Hg CO2 for 6 h) also led to an increased Abeta production. The findings suggest that hypocapnia (e.g. during general anesthesia) could exacerbate AD neuropathogenesis. Copyright (c) 2004 S. Karger AG, Basel.

  20. Can earth's magnetic micropulsations induce brain activities modifications?

    International Nuclear Information System (INIS)

    Assis, Altair Souza de

    2008-01-01

    Full text: We present in this paper preliminary study on which level earth's magnetic micro pulsations might interact with human brain activities. Magnetic micro pulsations are magnetospheric plasma wave Eigenmodes that are generated at the earth's magnetosphere and, via magnetospheric-ionospheric coupling induce ionospheric currents, and this ionospheric current pattern creates surface geomagnetic perturbations, which induce earth's surface electrical currents, and they are easily detected by earth's based magnetometers. These Eigenmodes are basically of Alfven type, and can be generated, for instance, by magnetic storms, situation where they are more intense and, in principle, might be felt by a more sensible human brain. Here, we also show how the modes are generated and present theirs basic physical properties. Finally, we compare the magnetic field level at the brain with the micro pulsation magnetic intensity. (author)

  1. Activation of D1 dopamine receptors induces emergence from isoflurane general anesthesia

    Science.gov (United States)

    Taylor, Norman E.; Chemali, Jessica J.; Brown, Emery N.; Solt, Ken

    2012-01-01

    BACKGROUND A recent study showed that methylphenidate induces emergence from isoflurane anesthesia. Methylphenidate inhibits dopamine and norepinephrine reuptake transporters. The objective of this study was to test the hypothesis that selective dopamine receptor activation induces emergence from isoflurane anesthesia. METHODS In adult rats, we tested the effects of chloro-APB (D1 agonist) and quinpirole (D2 agonist) on time to emergence from isoflurane general anesthesia. We then performed a dose–response study to test for chloro-APB-induced restoration of righting during continuous isoflurane anesthesia. SCH-23390 (D1 antagonist) was used to confirm that the effects induced by chloro-APB are specifically mediated by D1 receptors. In a separate group of animals, spectral analysis was performed on surface electroencephalogram recordings to assess neurophysiological changes induced by chloro-APB and quinpirole during isoflurane general anesthesia. RESULTS Chloro-APB decreased median time to emergence from 330s to 50s. The median difference in time to emergence between the saline control group (n=6) and the chloro-APB group (n = 6) was 222s (95% CI: 77–534s, Mann-Whitney test). This difference was statistically significant (p = 0.0082). During continuous isoflurane anesthesia, chloro-APB dose-dependently restored righting (n = 6) and decreased electroencephalogram delta power (n = 4). These effects were inhibited by pretreatment with SCH-23390. Quinpirole did not restore righting (n = 6) and had no significant effect on the electroencephalogram (n = 4) during continuous isoflurane anesthesia. CONCLUSIONS Activation of D1 receptors by chloro-APB decreases time to emergence from isoflurane anesthesia, and produces behavioral and neurophysiological evidence of arousal during continuous isoflurane anesthesia. These findings suggest that selective activation of a D1 receptor-mediated arousal mechanism is sufficient to induce emergence from isoflurane general

  2. Metformin induces differentiation in acute promyelocytic leukemia by activating the MEK/ERK signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Huai, Lei; Wang, Cuicui; Zhang, Cuiping; Li, Qihui; Chen, Yirui; Jia, Yujiao; Li, Yan; Xing, Haiyan; Tian, Zheng; Rao, Qing; Wang, Min [State Key Laboratory of Experimental Hematology, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300020 (China); Wang, Jianxiang, E-mail: wangjx@ihcams.ac.cn [State Key Laboratory of Experimental Hematology, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300020 (China)

    2012-06-08

    Highlights: Black-Right-Pointing-Pointer Metformin induces differentiation in NB4 and primary APL cells. Black-Right-Pointing-Pointer Metformin induces activation of the MEK/ERK signaling pathway in APL cells. Black-Right-Pointing-Pointer Metformin synergizes with ATRA to trigger maturation of NB4 and primary APL cells. Black-Right-Pointing-Pointer Metformin induces the relocalization and degradation of the PML-RAR{alpha} fusion protein. Black-Right-Pointing-Pointer The study may be applicable for new differentiation therapy in cancer treatment. -- Abstract: Recent studies have shown that metformin, a widely used antidiabetic agent, may reduce the risk of cancer development. In this study, we investigated the antitumoral effect of metformin on both acute myeloid leukemia (AML) and acute promyelocytic leukemia (APL) cells. Metformin induced apoptosis with partial differentiation in an APL cell line, NB4, but only displayed a proapoptotic effect on several non-M3 AML cell lines. Further analysis revealed that a strong synergistic effect existed between metformin and all-trans retinoic acid (ATRA) during APL cell maturation and that metformin induced the hyperphosphorylation of extracellular signal-regulated kinase (ERK) in APL cells. U0126, a specific MEK/ERK activation inhibitor, abrogated metformin-induced differentiation. Finally, we found that metformin induced the degradation of the oncoproteins PML-RAR{alpha} and c-Myc and activated caspase-3. In conclusion, these results suggest that metformin treatment may contribute to the enhancement of ATRA-induced differentiation in APL, which may deepen the understanding of APL maturation and thus provide insight for new therapy strategies.

  3. Low LET radiation-induced telomerase catalytic subunit promoter activation is mediated by nuclear factor Kappa B

    International Nuclear Information System (INIS)

    Natarajan, M.; Hong, F.A.; Mohan, S.; Herman, T.S.

    2003-01-01

    Full text: The objective of this study is to understand whether low doses of low LET radiation induces survival advantage in normal cells. As an increase in telomerase activity is associated with longevity and cell proliferation, we examined the telomerase response following gamma-irradiation in normal aortic endothelial cells. Telomeric Repeat Amplification Protocol assay following low LET radiation showed an increase in telomerase enzyme activity as early as 8 h post irradiation and reaches its maximum at 24 h. Subsequent analysis revealed that the increased telomerse enzyme activity is due to increased synthesis resulting from an increased transcription. Examination of transcriptional activation of telomerase reverse transcriptase (TERT) promoter regulation showed an enhanced transcription of the telomerse gene following gamma-irradiation. In our previous reports we documented an increase in NF-kB DNA-binding property following low LET radiation (3). Therefore, to determine whether the activation of NF-kB-signaling is responsible for induced TERT promoter activation, cells transiently transfected with minimal promoter region of TERT containing wild type or mutant NF-kB binding site were examined following low LET radiation. TERT promoter activation was induced in wild type transfected cells whereas, in mutant kB binding site, the activation remained at the basal level similar to that of un-irradiated cells. More significantly, the gamma-ray mediated promoter activation of telomerase gene as well as induce telomerase enzyme activity was abrogated by ectopically expressing the IkBa mutant (IkBa (S32A/S36A)), which blocks NF-kB activation. The results thus suggest that exposure to low LET radiation could induce telomerase activity and the activation is at least, in part, mediated by the transcription factor NF-kB. Sustained activation of telomerase in these cells after low LET radiation may impart extended life span

  4. Jealousy increased by induced relative left frontal cortical activity.

    Science.gov (United States)

    Kelley, Nicholas J; Eastwick, Paul W; Harmon-Jones, Eddie; Schmeichel, Brandon J

    2015-10-01

    Asymmetric frontal cortical activity may be one key to the process linking social exclusion to jealous feelings. The current research examined the causal role of asymmetric frontal brain activity in modulating jealousy in response to social exclusion. Transcranial direct-current stimulation (tDCS) over the frontal cortex to manipulate asymmetric frontal cortical activity was combined with a modified version of the Cyberball paradigm designed to induce jealousy. After receiving 15 min of tDCS, participants were excluded by a desired partner and reported how jealous they felt. Among individuals who were excluded, tDCS to increase relative left frontal cortical activity caused greater levels of self-reported jealousy compared to tDCS to increase relative right frontal cortical activity or sham stimulation. Limitations concerning the specificity of this effect and implications for the role of the asymmetric prefrontal cortical activity in motivated behaviors are discussed. (c) 2015 APA, all rights reserved).

  5. Elevated p21-Activated Kinase 2 Activity Results in Anchorage-Independent Growth and Resistance to Anticancer Drug–Induced Cell Death

    Directory of Open Access Journals (Sweden)

    Jerry W. Marlin

    2009-03-01

    Full Text Available p21-Activated kinase 2 (PAK-2 seems to be a regulatory switch between cell survival and cell death signaling. We have shown previously that activation of full-length PAK-2 by Rac or Cdc42 stimulates cell survival, whereas caspase activation of PAK-2 to the proapoptotic PAK-2p34 fragment is involved in the cell death response. In this study, we present a role of elevated activity of full-length PAK-2 in anchorage-independent growth and resistance to anticancer drug–induced apoptosis of cancer cells. Hs578T human breast cancer cells that have low levels of PAK-2 activity were more sensitive to anticancer drug–induced apoptosis and showed higher levels of caspase activation of PAK-2 than MDA-MB435 and MCF-7 human breast cancer cells that have high levels of PAK-2 activity. To examine the role of elevated PAK-2 activity in breast cancer, we have introduced a conditionally active PAK-2 into Hs578T human breast cells. Conditional activation of PAK-2 causes loss of contact inhibition and anchorage-independent growth of Hs578T cells. Furthermore, conditional activation of PAK-2 suppresses activation of caspase 3, caspase activation of PAK-2, and apoptosis of Hs578T cells in response to the anticancer drug cisplatin. Our data suggest a novel mechanism by which full-length PAK-2 activity controls the apoptotic response by regulating levels of activated caspase 3 and thereby its own cleavage to the proapoptotic PAK-2p34 fragment. As a result, elevated PAK-2 activity interrupts the apoptotic response and thereby causes anchorage-independent survival and growth and resistance to anticancer drug–induced apoptosis.

  6. Activation of the hypothalamic-pituitary-adrenal stress axis induces cellular oxidative stress

    Directory of Open Access Journals (Sweden)

    Jereme G. Spiers

    2015-01-01

    Full Text Available Glucocorticoids released from the adrenal gland in response to stress-induced activation of the hypothalamic-pituitary-adrenal (HPA axis induce activity in the cellular reduction-oxidation (redox system. The redox system is a ubiquitous chemical mechanism allowing the transfer of electrons between donor/acceptors and target molecules during oxidative phosphorylation while simultaneously maintaining the overall cellular environment in a reduced state. The objective of this review is to present an overview of the current literature discussing the link between HPA axis-derived glucocorticoids and increased oxidative stress, particularly focussing on the redox changes observed in the hippocampus following glucocorticoid exposure.

  7. β2-adrenoceptor-induced modulation of transglutaminase 2 transamidase activity in cardiomyoblasts.

    Science.gov (United States)

    Vyas, Falguni S; Nelson, Carl P; Freeman, Fiona; Boocock, David J; Hargreaves, Alan J; Dickenson, John M

    2017-10-15

    Tissue transglutaminase 2 (TG2) is modulated by protein kinase A (PKA) mediated phosphorylation: however, the precise mechanism(s) of its modulation by G-protein coupled receptors coupled to PKA activation are not fully understood. In the current study we investigated the potential regulation of TG2 activity by the β 2 -adrenoceptor in rat H9c2 cardiomyoblasts. Transglutaminase transamidation activity was assessed using amine-incorporating and protein cross-linking assays. TG2 phosphorylation was determined via immunoprecipitation and Western blotting. The long acting β 2 -adrenoceptor agonist formoterol induced time- and concentration-dependent increases in TG2 transamidation. Increases in TG2 activity were reduced by the TG2 inhibitors Z-DON (Benzyloxycarbonyl-(6-Diazo-5-oxonorleucinyl)-L-valinyl-L-prolinyl-L-leucinmethylester) and R283 ((1,3,dimethyl-2[2-oxo-propyl]thio)imidazole chloride). Responses to formoterol were blocked by pharmacological inhibition of PKA, extracellular signal-regulated kinase 1 and 2 (ERK1/2), or phosphatidylinositol 3-kinase (PI-3K) signalling. Furthermore, the removal of extracellular Ca 2+ also attenuated formoterol-induced TG2 activation. Fluorescence microscopy demonstrated TG2-induced biotin-X-cadaverine incorporation into proteins. Formoterol increased the levels of TG2-associated phosphoserine and phosphothreonine, which were blocked by inhibition of PKA, ERK1/2 or PI-3K signalling. Subsequent proteomic analysis identified known (e.g. lactate dehydrogenase A chain) and novel (e.g. Protein S100-A6) protein substrates for TG2. Taken together, the data obtained suggest that β 2 -adrenoceptor-induced modulation of TG2 represents a novel paradigm in β 2 -adrenoceptor cell signalling, expanding the repertoire of cellular functions responsive to catecholamine stimulation. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Paraquat and maneb co-exposure induces noradrenergic locus coeruleus neurodegeneration through NADPH oxidase-mediated microglial activation

    International Nuclear Information System (INIS)

    Hou, Liyan; Zhang, Cong; Wang, Ke; Liu, Xiaofang; Wang, Hongwei; Che, Yuning; Sun, Fuqiang; Zhou, Xueying; Zhao, Xiulan; Wang, Qingshan

    2017-01-01

    Highlights: • Microglial activation induced by paraquat and maneb precedes noradrenergic neurodegeneration in locus coeruleus. • NADPH oxidase activation contributes to microglia-mediated neuroinflammation and related noradrenergic neurodegeneration. • Inhibition of NADPH oxidase by apocynin protects noradrenergic neurons against paraquat and maneb-induced toxicity. - Abstract: Co-exposure to paraquat (PQ) and maneb (Mb) has been shown to increase the risk of Parkinson’s disease (PD) and dopaminergic (DA) neurodegeneration in the substantia nigra pars compacta (SNpc) is observed in PQ and Mb-treated experimental animals. The loss of noradrenergic locus coeruleus (LC/NE) neurons in brainstem is a common feature shared by multiple neurodegenerative diseases, including PD. However, whether PQ and Mb is able to damage LC/NE neurons remains undefined. In this study, mice treated with combined PQ and Mb displayed progressive LC/NE neurodegeneration. Time course studies revealed that the activation of microglia preceded LC/NE neurodegeneration. Mechanistically, the activation of NADPH oxidase contributed to microglial activation and subsequent LC/NE neurodegeneration. We found that PQ and Mb co-exposure induced activation of NADPH oxidase as shown by increased superoxide production and membrane translocation of p47 phox , a cytosolic subunit of NADPH oxidase. Inhibition of NADPH oxidase by apocynin, a widely used NADPH oxidase inhibitor, suppressed microglial activation and gene expressions of proinflammatory factors. Furthermore, reduced activation of nuclear factor-κB (NF-κB) pathway was observed in apocynin-treated mice. More importantly, inhibition of NADPH oxidase by apocynin afforded LC/NE neuroprotection against PQ and Mb-induced neurotoxicity. Thus, our findings revealed the critical role NADPH oxidase-mediated microglial activation in driving LC/NE neurodegeneration induced by PQ and Mb, providing new insights into the pathogenesis of environmental

  9. YC-1 potentiates cAMP-induced CREB activation and nitric oxide production in alveolar macrophages

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Tsong-Long, E-mail: htl@mail.cgu.edu.tw [Graduate Institute of Natural Products, College of Medicine, Chang Gung University, Taoyuan, Taiwan (China); Chinese Herbal Medicine Research Team, Healthy Aging Research Center, Chang Gung University, Kweishan, Taoyuan, Taiwan (China); Tang, Ming-Chi [Graduate Institute of Natural Products, College of Medicine, Chang Gung University, Taoyuan, Taiwan (China); Kuo, Liang-Mou [Department of General Surgery, Chang Gung Memorial Hospital at Chia-Yi, Taiwan (China); Chang, Wen-De; Chung, Pei-Jen; Chang, Ya-Wen; Fang, Yao-Ching [Graduate Institute of Natural Products, College of Medicine, Chang Gung University, Taoyuan, Taiwan (China)

    2012-04-15

    Alveolar macrophages play significant roles in the pathogenesis of several inflammatory lung diseases. Increases in exhaled nitric oxide (NO) are well documented to reflect disease severity in the airway. In this study, we investigated the effect of 3-(5′-hydroxymethyl-2′-furyl)-1-benzyl indazole (YC-1), a known activator of soluble guanylyl cyclase, on prostaglandin (PG)E{sub 1} (a stable PGE{sub 2} analogue) and forskolin (a adenylate cyclase activator) induced NO production and inducible NO synthase (iNOS) expression in rat alveolar macrophages (NR8383). YC-1 did not directly cause NO production or iNOS expression, but drastically potentiated PGE{sub 1}- or forskolin-induced NO production and iNOS expression in NR8383 alveolar macrophages. Combination treatment with YC-1 and PGE{sub 1} significantly increased phosphorylation of the cAMP response element-binding protein (CREB), but not nuclear factor (NF)-κB activation. The combined effect on NO production, iNOS expression, and CREB phosphorylation was reversed by a protein kinase (PK)A inhibitor (H89), suggesting that the potentiating functions were mediated through a cAMP/PKA signaling pathway. Consistent with this, cAMP analogues, but not the cGMP analogue, caused NO release, iNOS expression, and CREB activation. YC-1 treatment induced an increase in PGE{sub 1}-induced cAMP formation, which occurred through the inhibition of cAMP-specific phosphodiesterase (PDE) activity. Furthermore, the combination of rolipram (an inhibitor of PDE4), but not milronone (an inhibitor of PDE3), and PGE{sub 1} also triggered NO production and iNOS expression. In summary, YC-1 potentiates PGE{sub 1}-induced NO production and iNOS expression in alveolar macrophages through inhibition of cAMP PDE activity and activation of the cAMP/PKA/CREB signaling pathway. Highlights: ► YC-1 potentiated PGE1-induced iNOS expression in alveolar macrophages. ► The combination of YC-1 and PGE1 increased CREB but not NFκB activation.

  10. Ultrafine carbon particles promote rotenone-induced dopamine neuronal loss through activating microglial NADPH oxidase

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yinxi; Liu, Dan; Zhang, Huifeng; Wang, Yixin [Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, 100191 (China); Wei, Ling [Beijing Center for Physical & Chemical Analysis, Beijing 100089 (China); Liu, Yutong [School of Life Science, Beijing Normal University, Beijing 100875 (China); Liao, Jieying [Department of Translational Medicine, Xiamen Institute of Rare Earth Materials, Chinese Academy of Sciences, Xiamen 361024 (China); Gao, Hui-Ming [Model Animal Research Center of Nanjing University, Nanjing 211800 (China); Zhou, Hui, E-mail: hardhui@gmail.com [Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, 100191 (China)

    2017-05-01

    Background: Atmospheric ultrafine particles (UFPs) and pesticide rotenone were considered as potential environmental risk factors for Parkinson's disease (PD). However, whether and how UFPs alone and in combination with rotenone affect the pathogenesis of PD remains largely unknown. Methods: Ultrafine carbon black (ufCB, a surrogate of UFPs) and rotenone were used individually or in combination to determine their roles in chronic dopaminergic (DA) loss in neuron-glia, and neuron-enriched, mix-glia cultures. Immunochemistry using antibody against tyrosine hydroxylase was performed to detect DA neuronal loss. Measurement of extracellular superoxide and intracellular reactive oxygen species (ROS) were performed to examine activation of NADPH oxidase. Genetic deletion and pharmacological inhibition of NADPH oxidase and MAC-1 receptor in microglia were employed to examine their role in DA neuronal loss triggered by ufCB and rotenone. Results: In rodent midbrain neuron-glia cultures, ufCB and rotenone alone caused neuronal death in a dose-dependent manner. In particularly, ufCB at doses of 50 and 100 μg/cm{sup 2} induced significant loss of DA neurons. More importantly, nontoxic doses of ufCB (10 μg/cm{sup 2}) and rotenone (2 nM) induced synergistic toxicity to DA neurons. Microglial activation was essential in this process. Furthermore, superoxide production from microglial NADPH oxidase was critical in ufCB/rotenone-induced neurotoxicity. Studies in mix-glia cultures showed that ufCB treatment activated microglial NADPH oxidase to induce superoxide production. Firstly, ufCB enhanced the expression of NADPH oxidase subunits (gp91{sup phox}, p47{sup phox} and p40{sup phox}); secondly, ufCB was recognized by microglial surface MAC-1 receptor and consequently promoted rotenone-induced p47{sup phox} and p67{sup phox} translocation assembling active NADPH oxidase. Conclusion: ufCB and rotenone worked in synergy to activate NADPH oxidase in microglia, leading to

  11. Ultrafine carbon particles promote rotenone-induced dopamine neuronal loss through activating microglial NADPH oxidase

    International Nuclear Information System (INIS)

    Wang, Yinxi; Liu, Dan; Zhang, Huifeng; Wang, Yixin; Wei, Ling; Liu, Yutong; Liao, Jieying; Gao, Hui-Ming; Zhou, Hui

    2017-01-01

    Background: Atmospheric ultrafine particles (UFPs) and pesticide rotenone were considered as potential environmental risk factors for Parkinson's disease (PD). However, whether and how UFPs alone and in combination with rotenone affect the pathogenesis of PD remains largely unknown. Methods: Ultrafine carbon black (ufCB, a surrogate of UFPs) and rotenone were used individually or in combination to determine their roles in chronic dopaminergic (DA) loss in neuron-glia, and neuron-enriched, mix-glia cultures. Immunochemistry using antibody against tyrosine hydroxylase was performed to detect DA neuronal loss. Measurement of extracellular superoxide and intracellular reactive oxygen species (ROS) were performed to examine activation of NADPH oxidase. Genetic deletion and pharmacological inhibition of NADPH oxidase and MAC-1 receptor in microglia were employed to examine their role in DA neuronal loss triggered by ufCB and rotenone. Results: In rodent midbrain neuron-glia cultures, ufCB and rotenone alone caused neuronal death in a dose-dependent manner. In particularly, ufCB at doses of 50 and 100 μg/cm 2 induced significant loss of DA neurons. More importantly, nontoxic doses of ufCB (10 μg/cm 2 ) and rotenone (2 nM) induced synergistic toxicity to DA neurons. Microglial activation was essential in this process. Furthermore, superoxide production from microglial NADPH oxidase was critical in ufCB/rotenone-induced neurotoxicity. Studies in mix-glia cultures showed that ufCB treatment activated microglial NADPH oxidase to induce superoxide production. Firstly, ufCB enhanced the expression of NADPH oxidase subunits (gp91 phox , p47 phox and p40 phox ); secondly, ufCB was recognized by microglial surface MAC-1 receptor and consequently promoted rotenone-induced p47 phox and p67 phox translocation assembling active NADPH oxidase. Conclusion: ufCB and rotenone worked in synergy to activate NADPH oxidase in microglia, leading to oxidative damage to DA neurons. Our

  12. Use of Activated Carbon in Packaging to Attenuate Formaldehyde-Induced and Formic Acid-Induced Degradation and Reduce Gelatin Cross-Linking in Solid Dosage Forms.

    Science.gov (United States)

    Colgan, Stephen T; Zelesky, Todd C; Chen, Raymond; Likar, Michael D; MacDonald, Bruce C; Hawkins, Joel M; Carroll, Sophia C; Johnson, Gail M; Space, J Sean; Jensen, James F; DeMatteo, Vincent A

    2016-07-01

    Formaldehyde and formic acid are reactive impurities found in commonly used excipients and can be responsible for limiting drug product shelf-life. Described here is the use of activated carbon in drug product packaging to attenuate formaldehyde-induced and formic acid-induced drug degradation in tablets and cross-linking in hard gelatin capsules. Several pharmaceutical products with known or potential vulnerabilities to formaldehyde-induced or formic acid-induced degradation or gelatin cross-linking were subjected to accelerated stability challenges in the presence and absence of activated carbon. The effects of time and storage conditions were determined. For all of the products studied, activated carbon attenuated drug degradation or gelatin cross-linking. This novel use of activated carbon in pharmaceutical packaging may be useful for enhancing the chemical stability of drug products or the dissolution stability of gelatin-containing dosage forms and may allow for the 1) extension of a drug product's shelf-life when the limiting attribute is a degradation product induced by a reactive impurity, 2) marketing of a drug product in hotter and more humid climatic zones than currently supported without the use of activated carbon, and 3) enhanced dissolution stability of products that are vulnerable to gelatin cross-linking. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  13. Propofol and magnesium attenuate isoflurane-induced caspase-3 activation via inhibiting mitochondrial permeability transition pore

    Directory of Open Access Journals (Sweden)

    Zhang Yiying

    2012-08-01

    Full Text Available Abstract Background The inhalation anesthetic isoflurane has been shown to open the mitochondrial permeability transition pore (mPTP and induce caspase activation and apoptosis, which may lead to learning and memory impairment. Cyclosporine A, a blocker of mPTP opening might attenuate the isoflurane-induced mPTP opening, lessening its ripple effects. Magnesium and anesthetic propofol are also mPTP blockers. We therefore set out to determine whether propofol and magnesium can attenuate the isoflurane-induced caspase activation and mPTP opening. Methods We investigated the effects of magnesium sulfate (Mg2+, propofol, and isoflurane on the opening of mPTP and caspase activation in H4 human neuroglioma cells stably transfected to express full-length human amyloid precursor protein (APP (H4 APP cells and in six day-old wild-type mice, employing Western blot analysis and flowcytometry. Results Here we show that Mg2+ and propofol attenuated the isoflurane-induced caspase-3 activation in H4-APP cells and mouse brain tissue. Moreover, Mg2+ and propofol, the blockers of mPTP opening, mitigated the isoflurane-induced mPTP opening in the H4-APP cells. Conclusion These data illustrate that Mg2+ and propofol may ameliorate the isoflurane-induced neurotoxicity by inhibiting its mitochondrial dysfunction. Pending further studies, these findings may suggest the use of Mg2+ and propofol in preventing and treating anesthesia neurotoxicity.

  14. Activation of PKA/CREB Signaling is Involved in BMP9-Induced Osteogenic Differentiation of Mesenchymal Stem Cells

    Directory of Open Access Journals (Sweden)

    Hongyu Zhang

    2015-09-01

    Full Text Available Background/Aims: BMP9 is highly capable of promoting osteogenic differentiation of mesenchymal stem cells (MSCs although the molecular mechanism involved is largely unknown. Here, we explored the detail role of PKA/CREB signaling in BMP9-induced osteogenic differentiation. Methods: Activation status of PKA/CREB signaling is assessed by nonradioactive assay and Western blot. Using PKA inhibitors and a dominant negative protein of CREB (A-CREB, we investigated the effect of PKA/CREB signaling on BMP9-induced osteogenic differentiation. Results: We found that BMP9 promotes PKA activity and enhances CREB phosphorylation in MSCs. BMP9 is shown to down-regulate protein kinase A inhibitor γ (PKIγ expression. We demonstrated that PKA inhibitors suppress BMP9-induced early osteogenic marker alkaline phosphatase (ALP activity in MSCs as well as late osteogenic markers osteopontin (OPN, osteocalcin (OCN and matrix mineralization. We found that PKA inhibitor reduces BMP9-induced Runx2 activation and p38 phosphorylation in MSCs. Lastly, interference of CREB function by A-CREB decreased BMP9-induced osteogenic differentiation as well. Conclusion: Our results revealed that BMP9 may activate PKA/CREB signaling in MSCs through suppression of PKIγ expression. It is noteworthy that inhibition of PKA/CREB signaling may impair BMP9-induced osteogenic differentiation of MSCs, implying that activation of PKA/CREB signaling is required for BMP9 osteoinductive activity.

  15. Platelet-derived-growth-factor-induced signalling in human platelets: phosphoinositide-3-kinase-dependent inhibition of platelet activation.

    Science.gov (United States)

    Selheim, F; Fukami, M H; Holmsen, H; Vassbotn, F S

    2000-09-01

    Human platelets release platelet-derived growth factor (PDGF) from alpha-granules during platelet activation. We have previously shown that platelets have PDGF alpha-receptors, a transmembrane tyrosine kinase that takes part in negative feedback regulation during platelet activation. Here we have described a study of PDGF-induced tyrosine phosphorylation of platelet substrates and phosphoinositide 3-kinase (PI-3K) activity in collagen-stimulated platelets. By immunoblotting with phosphotyrosine antibodies of collagen-activated platelets we found that PDGF increased the phosphorylation of several platelet substrates, e.g. pp140, pp120 and pp85. PDGF inhibited collagen-induced platelet activation in the presence of inhibitors of autocrine stimulation, thus blocking the pure collagen-induced signal transduction. PDGF enhanced the collagen-induced formation of PtdIns(3,4)P(2) and PtdIns(3,4,5)P(3) as measured by HPLC. Wortmannin and LY294002, two unrelated inhibitors of PI-3K, were used to investigate the role of PI-3K in PDGF-induced platelet signalling. Incubation of platelets with wortmannin and LY294002 blocked the formation of three phosphorylated inositides as well as the inhibitory effect of PDGF on collagen-induced platelet activation. We conclude that the inhibitory effect of PDGF on platelet activation is PI-3K dependent. This is the first demonstration of a negative regulatory function of 3-phosphorylated inositides in platelets.

  16. Dopamine Attenuates Ketamine-Induced Neuronal Apoptosis in the Developing Rat Retina Independent of Early Synchronized Spontaneous Network Activity.

    Science.gov (United States)

    Dong, Jing; Gao, Lingqi; Han, Junde; Zhang, Junjie; Zheng, Jijian

    2017-07-01

    Deprivation of spontaneous rhythmic electrical activity in early development by anesthesia administration, among other interventions, induces neuronal apoptosis. However, it is unclear whether enhancement of neuronal electrical activity attenuates neuronal apoptosis in either normal development or after anesthesia exposure. The present study investigated the effects of dopamine, an enhancer of spontaneous rhythmic electrical activity, on ketamine-induced neuronal apoptosis in the developing rat retina. TUNEL and immunohistochemical assays indicated that ketamine time- and dose-dependently aggravated physiological and ketamine-induced apoptosis and inhibited early-synchronized spontaneous network activity. Dopamine administration reversed ketamine-induced neuronal apoptosis, but did not reverse the inhibitory effects of ketamine on early synchronized spontaneous network activity despite enhancing it in controls. Blockade of D1, D2, and A2A receptors and inhibition of cAMP/PKA signaling partially antagonized the protective effect of dopamine against ketamine-induced apoptosis. Together, these data indicate that dopamine attenuates ketamine-induced neuronal apoptosis in the developing rat retina by activating the D1, D2, and A2A receptors, and upregulating cAMP/PKA signaling, rather than through modulation of early synchronized spontaneous network activity.

  17. Effects of scallop shell extract on scopolamine-induced memory impairment and MK801-induced locomotor activity

    OpenAIRE

    HASEGAWA, Yasushi; INOUE, Tatsuro; KAWAMINAMI, Satoshi; FUJITA, Miho

    2016-01-01

    ObjectiveTo evaluate the neuroprotective effects of the organic components of scallop shells (scallop shell extract) on memory impairment and locomotor activity induced by scopolamine or 5-methyl-10,11-dihydro-5H-dibenzo (a,d) cyclohepten-5,10-imine (MK801).MethodsEffect of the scallop shell extract on memory impairment and locomotor activity was investigated using the Y-maze test, the Morris water maze test, and the open field test.ResultsScallop shell extract significantly reduced scopolami...

  18. Fatigue-induced changes in group IV muscle afferent activity: differences between high- and low-frequency electrically induced fatigues.

    Science.gov (United States)

    Darques, J L; Jammes, Y

    1997-03-07

    Recordings of group IV afferent activity of tibialis anterior muscle were performed in paralysed rabbits during runs of electrically induced fatigue produced by direct muscle stimulation at a high (100 Hz, high-frequency fatigue HFF) or a low rate (10 Hz, low-frequency fatigue LFF). In addition to analysis of afferent nerve action potentials, muscle force and compound muscle action potentials (M waves) elicited by direct muscle stimulation with single shocks were recorded. Changes in M wave configuration were used as an index of the altered propagation of membrane potentials and the associated efflux of potassium from muscle fibers. The data show that increased group IV afferent activity occurred during LFF as well as HFF trials and developed parallel with force failure. Enhanced afferent activity was significantly higher during LFF (maximal delta f(impulses) = 249 +/- 35%) than HFF (147 +/- 45%). No correlation was obtained between the responses of group IV afferents to LFF or to pressure exerted on tibialis anterior muscle. On the other hand, decreased M wave amplitude was minimal with LFF while it was pronounced with HFF. Close correlations were found between fatigue-induced activation of group IV afferents and decreases in force or M wave amplitude, but their strength was significantly higher with LFF compared to HFF. Thus, electrically induced fatigue activates group IV muscle afferents with a prominent effect of low-frequency stimulation. The mechanism of muscle afferent stimulation does not seem to be due to the sole increase in extracellular potassium concentration, but also by the efflux of muscle metabolites, present during fatiguing contractions at low rate of stimulation.

  19. Regorafenib impairs mitochondrial functions, activates AMP-activated protein kinase, induces autophagy, and causes rat hepatocyte necrosis.

    Science.gov (United States)

    Weng, Zuquan; Luo, Yong; Yang, Xi; Greenhaw, James J; Li, Haibo; Xie, Liming; Mattes, William B; Shi, Qiang

    2015-01-02

    The tyrosine kinase inhibitor regorafenib was approved by regulatory agencies for cancer treatment, albeit with strong warnings of severe hepatotoxicity included in the product label. The basis of this toxicity is unknown; one possible mechanism, that of mitochondrial damage, was tested. In isolated rat liver mitochondria, regorafenib directly uncoupled oxidative phosphorylation (OXPHOS) and promoted calcium overload-induced swelling, which were respectively prevented by the recoupler 6-ketocholestanol (KC) and the mitochondrial permeability transition (MPT) pore blocker cyclosporine A (CsA). In primary hepatocytes, regorafenib uncoupled OXPHOS, disrupted mitochondrial inner membrane potential (MMP), and decreased cellular ATP at 1h, and triggered MPT at 3h, which was followed by necrosis but not apoptosis at 7h and 24h, all of which were abrogated by KC. The combination of the glycolysis enhancer fructose plus the mitochondrial ATPase synthase inhibitor oligomycin A abolished regorafenib induced necrosis at 7h. This effect was not seen at 24h nor with the fructose or oligomycin A separately. CsA in combination with trifluoperazine, both MPT blockers, showed similar effects. Two compensatory mechanisms, activation of AMP-activated protein kinase (AMPK) to ameliorate ATP shortage and induction of autophagy to remove dysfunctional mitochondria, were found to be mobilized. Hepatocyte necrosis was enhanced either by the AMPK inhibitor Compound C or the autophagy inhibitor chloroquine, while autophagy inducer rapamycin was strongly cytoprotective. Remarkably, all toxic effects were observed at clinically-relevant concentrations of 2.5-15μM. These data suggest that uncoupling of OXPHOS and the resulting ATP shortage and MPT induction are the key mechanisms for regorafenib induced hepatocyte injury, and AMPK activation and autophagy induction serve as pro-survival pathways against such toxicity. Published by Elsevier Ireland Ltd.

  20. Effect of dietary fiber on the activity of intestinal and fecal beta-glucuronidase activity during 1,2-dimethylhydrazine induced colon carcinogenesis.

    Science.gov (United States)

    Manoj, G; Thampi, B S; Leelamma, S; Menon, P V

    2001-01-01

    The effects of fiber isolated from black gram (Phaseolus mungo) and coconut (Cocos nucifera) kernel on the metabolic activity of intestinal and fecal beta glucuronidase activity during 1,2-dimethylhydrazine induced colon carcinogenesis were studied. The results indicated that the inclusion of fiber from black gram and coconut kernel generally supported lower specific activities and less fecal output of beta-glucuronidase than did the fiber free diet. This study suggests that the fibers isolated from coconut or black gram may potentially play a role in preventing the formation of colon tumors induced by the carcinogen 1,2-dimethylhydrazine by reducing the activity of the intestinal as well as fecal beta-glucuronidase.

  1. Benchmark studies of induced radioactivity produced in LHC materials, Part I: Specific activities.

    Science.gov (United States)

    Brugger, M; Khater, H; Mayer, S; Prinz, A; Roesler, S; Ulrici, L; Vincke, H

    2005-01-01

    Samples of materials which will be used in the LHC machine for shielding and construction components were irradiated in the stray radiation field of the CERN-EU high-energy reference field facility. After irradiation, the specific activities induced in the various samples were analysed with a high-precision gamma spectrometer at various cooling times, allowing identification of isotopes with a wide range of half-lives. Furthermore, the irradiation experiment was simulated in detail with the FLUKA Monte Carlo code. A comparison of measured and calculated specific activities shows good agreement, supporting the use of FLUKA for estimating the level of induced activity in the LHC.

  2. Benchmark studies of induced radioactivity produced in LHC materials, part I: Specific activities

    International Nuclear Information System (INIS)

    Brugger, M.; Khater, H.; Mayer, S.; Prinz, A.; Roesler, S.; Ulrici, L.; Vincke, H.

    2005-01-01

    Samples of materials which will be used in the LHC machine for shielding and construction components were irradiated in the stray radiation field of the CERN-EU high-energy reference field facility. After irradiation, the specific activities induced in the various samples were analysed with a high-precision gamma spectrometer at various cooling times, allowing identification of isotopes with a wide range of half-lives. Furthermore, the irradiation experiment was simulated in detail with the FLUKA Monte Carlo code. A comparison of measured and calculated specific activities shows good agreement, supporting the use of FLUKA for estimating the level of induced activity in the LHC. (authors)

  3. Discrimination and Assessment of Induced Seismicity in Active Tectonic Zones: A Case Study from Southern California

    Science.gov (United States)

    Bachmann, C. E.; Lindsey, N.; Foxall, W.; Robertson, M.

    2014-12-01

    Earthquakes induced by human activity have become a matter of heightened public concern during recent years. Of particular concern is seismicity associated with wastewater injection, which has included events having magnitudes greater than 5. The causes of the induced events are primarily changes in pore-pressure, fluid volume and perhaps temperature due to injection. Recent research in the US has focused on mid-continental regions having low rates of naturally-occurring seismicity, where induced events can be identified by relatively straightforward spatial and temporal correlation of seismicity with high-volume injection activities. Recent examples include events correlated with injection of wastewater in Oklahoma, Arkansas, Texas and Ohio, and long-term brine injection in the Paradox Valley in Colorado. Even in some of the cases where there appears at first sight to be a clear spatial correlation between seismicity and injection, it has been difficult to establish causality definitively. Here, we discuss methods to identify induced seismicity in active tectonic regions. We concentrate our study on Southern California, where large numbers of wastewater injection wells are located in oil-producing basins that experience moderate to high rates of naturally-occurring seismicity. Using the catalog of high-precision CISN relocations produced by Hauksson et al. (BSSA, 2012), we aim to discriminate induced from natural events based on spatio-temporal patterns of seismicity occurrence characteristics and their relationships to injection activities, known active faults and other faults favorably oriented for slip under the tectonic stress field. Since the vast majority of induced earthquakes are very small, it is crucial to include all events above the detection threshold of the CISN in each area studied. In addition to exploring the correlation of seismicity to injection activities in time and space, we analyze variations in frequency-magnitude distributions, which can

  4. Photo-induced optical activity in phase-change memory materials.

    Science.gov (United States)

    Borisenko, Konstantin B; Shanmugam, Janaki; Williams, Benjamin A O; Ewart, Paul; Gholipour, Behrad; Hewak, Daniel W; Hussain, Rohanah; Jávorfi, Tamás; Siligardi, Giuliano; Kirkland, Angus I

    2015-03-05

    We demonstrate that optical activity in amorphous isotropic thin films of pure Ge2Sb2Te5 and N-doped Ge2Sb2Te5N phase-change memory materials can be induced using rapid photo crystallisation with circularly polarised laser light. The new anisotropic phase transition has been confirmed by circular dichroism measurements. This opens up the possibility of controlled induction of optical activity at the nanosecond time scale for exploitation in a new generation of high-density optical memory, fast chiroptical switches and chiral metamaterials.

  5. PKCδ-dependent p47phox activation mediates methamphetamine-induced dopaminergic neurotoxicity.

    Science.gov (United States)

    Dang, Duy-Khanh; Shin, Eun-Joo; Kim, Dae-Joong; Tran, Hai-Quyen; Jeong, Ji Hoon; Jang, Choon-Gon; Ottersen, Ole Petter; Nah, Seung-Yeol; Hong, Jau-Shyong; Nabeshima, Toshitaka; Kim, Hyoung-Chun

    2018-02-01

    Protein kinase C (PKC) has been recognized to activate NADPH oxidase (PHOX). However, the interaction between PKC and PHOX in vivo remains elusive. Treatment with methamphetamine (MA) resulted in a selective increase in PKCδ expression out of PKC isoforms. PKCδ co-immunoprecipitated with p47phox, and facilitated phosphorylation and membrane translocation of p47phox. MA-induced increases in PHOX activity and reactive oxygen species were attenuated by knockout of p47phox or PKCδ. In addition, MA-induced impairments in the Nrf-2-related glutathione synthetic system were also mitigated by knockout of p47phox or PKCδ. Glutathione-immunoreactivity was co-localized in Iba-1-labeled microglial cells and in NeuN-labeled neurons, but not in GFAP-labeled astrocytes, reflecting the necessity for self-protection against oxidative stress by mainly microglia. Buthionine-sulfoximine, an inhibitor of glutathione biosynthesis, potentiated microglial activation and pro-apoptotic changes, leading to dopaminergic losses. These neurotoxic processes were attenuated by rottlerin, a pharmacological inhibitor of PKCδ, genetic inhibitions of PKCδ [i.e., PKCδ knockout mice (KO) and PKCδ antisense oligonucleotide (ASO)], or genetic inhibition of p47phox (i.e., p47phox KO or p47phox ASO). Rottlerin did not exhibit any additive effects against the protective activity offered by genetic inhibition of p47phox. Therefore, we suggest that PKCδ is a critical regulator for p47phox activation induced by MA, and that Nrf-2-dependent GSH induction via inhibition of PKCδ or p47phox, is important for dopaminergic protection against MA insult. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Involvement of endoplasmic reticulum stress in albuminuria induced inflammasome activation in renal proximal tubular cells.

    Directory of Open Access Journals (Sweden)

    Li Fang

    Full Text Available Albuminuria contributes to the progression of tubulointerstitial fibrosis. Although it has been demonstrated that ongoing albuminuria leads to tubular injury manifested by the overexpression of numerous proinflammatory cytokines, the mechanism remains largely unknown. In this study, we found that the inflammasome activation which has been recognized as one of the cornerstones of intracellular surveillance system was associated with the severity of albuminuria in the renal biopsies specimens. In vitro, bovine serum albumin (BSA could also induce the activation of NLRP3 inflammasome in the cultured kidney epithelial cells (NRK-52E. Since there was a significant overlap of NLRP3 with the ER marker calreticulin, the ER stress provoked by BSA seemed to play a crucial role in the activation of inflammasome. Here, we demonstrated that the chemical chaperone taurine-conjugated ursodeoxycholic acid (TUDCA which was proved to be an enhancer for the adaptive capacity of ER could attenuate the inflammasome activation induced by albuminuria not only in vitro but also in diabetic nephropathy. Taken together, these data suggested that ER stress seemed to play an important role in albuminuria-induced inflammasome activation, elimination of ER stress via TUDCA might hold promise as a novel avenue for preventing inflammasome activation ameliorating kidney epithelial cells injury induced by albuminuria.

  7. Carbamazepine reduces memory induced activation of mesial temporal lobe structures: a pharmacological fMRI-study

    Directory of Open Access Journals (Sweden)

    Okujava Michael

    2001-11-01

    Full Text Available Abstract Background and Purpose It is not known whether carbamazepine (CBZ; a drug widely used in neurology and psychiatry influences the blood oxygenation level dependent (BOLD contrast changes induced by neuronal activation and measured by functional MRI (fMRI. We aimed to investigate the influence of CBZ on memory induced activation of the mesial temporal lobes in patients with symptomatic temporal lobe epilepsy (TLE. Material and Methods Twenty-one individual patients with refractory symptomatic TLE with different CBZ serum levels and 20 healthy controls were studied using BOLD fMRI. Mesial temporal lobe (MTL activation was induced by a task that is based on the retrieval of individually familiar visuo-spatial knowledge. The extent of significant MTL fMRI activation was measured and correlated with the CBZ serum level. Results In TLE patients, the extent of significant fMRI activation over both MTL was negatively correlated to the CBZ serum level (Spearman r = -0.654, P Conclusions In TLE patients, carbamazepine reduces the fMRI-detectable changes within the mesial temporal lobes as induced by effortful memory retrieval. FMRI appears to be suitable to study the effects of chronic drug treatment in patients with epilepsy.

  8. Peripheral nerve injury induces glial activation in primary motor cortex

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    Julieta Troncoso

    2015-02-01

    Full Text Available Preliminary evidence suggests that peripheral facial nerve injuries are associated with sensorimotor cortex reorganization. We have characterized facial nerve lesion-induced structural changes in primary motor cortex layer 5 pyramidal neurons and their relationship with glial cell density using a rodent facial paralysis model. First, we used adult transgenic mice expressing green fluorescent protein in microglia and yellow fluorescent protein in pyramidal neurons which were subjected to either unilateral lesion of the facial nerve or sham surgery. Two-photon excitation microscopy was then used for evaluating both layer 5 pyramidal neurons and microglia in vibrissal primary motor cortex (vM1. It was found that facial nerve lesion induced long-lasting changes in dendritic morphology of vM1 layer 5 pyramidal neurons and in their surrounding microglia. Pyramidal cells’ dendritic arborization underwent overall shrinkage and transient spine pruning. Moreover, microglial cell density surrounding vM1 layer 5 pyramidal neurons was significantly increased with morphological bias towards the activated phenotype. Additionally, we induced facial nerve lesion in Wistar rats to evaluate the degree and extension of facial nerve lesion-induced reorganization processes in central nervous system using neuronal and glial markers. Immunoreactivity to NeuN (neuronal nuclei antigen, GAP-43 (growth-associated protein 43, GFAP (glial fibrillary acidic protein, and Iba 1 (Ionized calcium binding adaptor molecule 1 were evaluated 1, 3, 7, 14, 28 and 35 days after either unilateral facial nerve lesion or sham surgery. Patches of decreased NeuN immunoreactivity were found bilaterally in vM1 as well as in primary somatosensory cortex (CxS1. Significantly increased GAP-43 immunoreactivity was found bilaterally after the lesion in hippocampus, striatum, and sensorimotor cortex. One day after lesion GFAP immunoreactivity increased bilaterally in hippocampus, subcortical white

  9. Opiate-induced suppression of rat hypoglossal motoneuron activity and its reversal by ampakine therapy.

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    Amanda R Lorier

    2010-01-01

    Full Text Available Hypoglossal (XII motoneurons innervate tongue muscles and are vital for maintaining upper-airway patency during inspiration. Depression of XII nerve activity by opioid analgesics is a significant clinical problem, but underlying mechanisms are poorly understood. Currently there are no suitable pharmacological approaches to counter opiate-induced suppression of XII nerve activity while maintaining analgesia. Ampakines accentuate alpha-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate (AMPA receptor responses. The AMPA family of glutamate receptors mediate excitatory transmission to XII motoneurons. Therefore the objectives were to determine whether the depressant actions of mu-opioid receptor activation on inspiratory activity includes a direct inhibitory action at the inspiratory premotoneuron to XII motoneuron synapse, and to identify underlying mechanism(s. We then examined whether ampakines counteract opioid-induced depression of XII motoneuron activity.A medullary slice preparation from neonatal rat that produces inspiratory-related output in vitro was used. Measurements of inspiratory burst amplitude and frequency were made from XII nerve roots. Whole-cell patch recordings from XII motoneurons were used to measure membrane currents and synaptic events. Application of the mu-opioid receptor agonist, DAMGO, to the XII nucleus depressed the output of inspiratory XII motoneurons via presynaptic inhibition of excitatory glutamatergic transmission. Ampakines (CX614 and CX717 alleviated DAMGO-induced depression of XII MN activity through postsynaptic actions on XII motoneurons.The inspiratory-depressant actions of opioid analgesics include presynaptic inhibition of XII motoneuron output. Ampakines counteract mu-opioid receptor-mediated depression of XII motoneuron inspiratory activity. These results suggest that ampakines may be beneficial in countering opiate-induced suppression of XII motoneuron activity and resultant impairment of airway patency.

  10. Inhibitory Effects of Ketamine on Lipopolysaccharide-Induced Microglial Activation

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    Yi Chang

    2009-01-01

    Full Text Available Microglia activated in response to brain injury release neurotoxic factors including nitric oxide (NO and proinflammatory cytokines such as tumor necrosis factor-α (TNF-α and interleukin-1β (IL-1β. Ketamine, an anesthetic induction agent, is generally reserved for use in patients with severe hypotension or respiratory depression. In this study, we found that ketamine (100 and 250 μM concentration-dependently inhibited lipopolysaccharide (LPS-induced NO and IL-1β release in primary cultured microglia. However, ketamine (100 and 250 μM did not significantly inhibit the LPS-induced TNF-α production in microglia, except at the higher concentration (500 μM. Further study of the molecular mechanisms revealed that ketamine markedly inhibited extracellular signal-regulated kinase (ERK1/2 phosphorylation but not c-Jun N-terminal kinase or p38 mitogen-activated protein kinase stimulated by LPS in microglia. These results suggest that microglial inactivation by ketamine is at least partially due to inhibition of ERK1/2 phosphorylation.

  11. DNA–PKcs–SIN1 complexation mediates low-dose X-ray irradiation (LDI)-induced Akt activation and osteoblast differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yong; Fang, Shi-ji [The Department of Orthopedics, The Second Affiliated Hospital of Soochow University, Suzhou 215000 (China); Zhu, Li-juan [Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and Institute of Neuroscience, Soochow University, Suzhou, Jiangsu 215021 (China); Zhu, Lun-qing, E-mail: xiaodongwangsz@163.com [The Center of Diagnosis and Treatment for Children’s Bone Diseases, The Children’s Hospital Affiliated to Soochow University, Suzhou, Jiangsu 215000 (China); Zhou, Xiao-zhong, E-mail: zhouxz@suda.edu.cn [The Department of Orthopedics, The Second Affiliated Hospital of Soochow University, Suzhou 215000 (China)

    2014-10-24

    Highlights: • LDI increases ALP activity, promotes type I collagen (Col I)/Runx2 mRNA expression. • LDI induces DNA–PKcs activation, which is required for osteoblast differentiation. • Akt activation mediates LDI-induced ALP activity and Col I/Runx2 mRNA increase. • DNA–PKcs–SIN1 complexation mediates LDI-induced Akt Ser-473 phosphorylation. • DNA–PKcs–SIN1 complexation is important for osteoblast differentiation. - Abstract: Low-dose irradiation (LDI) induces osteoblast differentiation, however the underlying mechanisms are not fully understood. In this study, we explored the potential role of DNA-dependent protein kinase catalytic subunit (DNA–PKcs)–Akt signaling in LDI-induced osteoblast differentiation. We confirmed that LDI promoted mouse calvarial osteoblast differentiation, which was detected by increased alkaline phosphatase (ALP) activity as well as mRNA expression of type I collagen (Col I) and runt-related transcription factor 2 (Runx2). In mouse osteoblasts, LDI (1 Gy) induced phosphorylation of DNA–PKcs and Akt (mainly at Ser-473). The kinase inhibitors against DNA–PKcs (NU-7026 and NU-7441) or Akt (LY294002, perifosine and MK-2206), as well as partial depletion of DNA–PKcs or Akt1 by targeted-shRNA, dramatically inhibited LDI-induced Akt activation and mouse osteoblast differentiation. Further, siRNA-knockdown of SIN1, a key component of mTOR complex 2 (mTORC2), also inhibited LDI-induced Akt Ser-473 phosphorylation as well as ALP activity increase and Col I/Runx2 expression in mouse osteoblasts. Co-immunoprecipitation (Co-IP) assay results demonstrated that LDI-induced DNA–PKcs–SIN1 complexation, which was inhibited by NU-7441 or SIN1 siRNA-knockdown in mouse osteoblasts. In summary, our data suggest that DNA–PKcs–SIN1 complexation-mediated Akt activation (Ser-473 phosphorylation) is required for mouse osteoblast differentiation.

  12. Active terahertz metamaterials based on liquid-crystal induced transparency and absorption

    Science.gov (United States)

    Yang, Lei; Fan, Fei; Chen, Meng; Zhang, Xuanzhou; Chang, Sheng-Jiang

    2017-01-01

    An active terahertz (THz) liquid crystal (LC) metamaterial has been experimentally investigated for THz wave modulation. Some interesting phenomena of resonance shifting, tunable electromagnetically induced transparency (EIT) and electromagnetically induced absorption (EIA) have been observed in the same device structure under different DC bias directions and different incident wave polarization directions by the THz time domain spectroscopy. Further theoretical studies indicate that these effects originate from interference and coupling between bright and dark mode components of elliptically polarized modes in the LC metamaterial, which are induced by the optical activity of LC alignment controllable by the electric field as well as the changes of LC refractive index. The LC layer is indeed a phase retarder and polarization converter that is controlled by the DC bias. The THz modulation depth of the analogs of EIT and EIA effects are 18.3 dB and 10.5 dB in their frequency band, respectively. Electrical control, large modulation depth and feasible integration of this LC device make it an ideal candidate for THz tunable filter, intensity modulator and spatial light modulator.

  13. Constraint-induced movement therapy improves upper limb activity and participation in hemiplegic cerebral palsy: a systematic review

    Directory of Open Access Journals (Sweden)

    Hsiu-Ching Chiu

    2016-07-01

    Full Text Available Questions: Does constraint-induced movement therapy improve activity and participation in children with hemiplegic cerebral palsy? Does it improve activity and participation more than the same dose of upper limb therapy without restraint? Is the effect of constraint-induced movement therapy related to the duration of intervention or the age of the children? Design: Systematic review of randomised trials with meta-analysis. Participants: Children with hemiplegic cerebral palsy with any level of motor disability. Intervention: The experimental group received constraint-induced movement therapy (defined as restraint of the less affected upper limb during supervised activity practice of the more affected upper limb. The control group received no intervention, sham intervention, or the same dose of upper limb therapy. Outcome measures: Measures of upper limb activity and participation were used in the analysis. Results: Constraint-induced movement therapy was more effective than no/sham intervention in terms of upper limb activity (SMD 0.63, 95% CI 0.20 to 1.06 and participation (SMD 1.21, 95% CI 0.41 to 2.02. However, constraint-induced movement therapy was no better than the same dose of upper limb therapy without restraint either in terms of upper limb activity (SMD 0.05, 95% CI –0.21 to 0.32 or participation (SMD –0.02, 95% CI –0.34 to 0.31. The effect of constraint-induced movement therapy was not related to the duration of intervention or the age of the children. Conclusions: This review suggests that constraint-induced movement therapy is more effective than no intervention, but no more effective than the same dose of upper limb practice without restraint. Registration: PROSPERO CRD42015024665. [Chiu H-C, Ada L (2016 Constraint-induced movement therapy improves upper limb activity and participation in hemiplegic cerebral palsy: a systematic review. Journal of Physiotherapy 62: 130–137

  14. Safrole oxide induces neuronal apoptosis through inhibition of integrin beta4/SOD activity and elevation of ROS/NADPH oxidase activity.

    Science.gov (United States)

    Su, Le; Zhao, BaoXiang; Lv, Xin; Wang, Nan; Zhao, Jing; Zhang, ShangLi; Miao, JunYing

    2007-02-20

    Neuronal apoptosis is a very important event in the development of the central nervous system (CNS), but the underlying mechanisms remain to be elucidated. We have previously shown that safrole oxide, a small molecule, induces integrin beta4 expression and promotes apoptosis in vascular endothelial cells. In this study, the effects of safrole oxide on cell growth and apoptosis have been examined in primary cultures of mouse neurons. Safrole oxide was found to significantly inhibit neuronal cell growth and to induce apoptosis. The inhibitory and apoptotic activities of safrole oxide followed a dose- and time-dependent manner. Interestingly, the expression of integrin beta4 was significantly inhibited with safrole oxide treatment. Furthermore, safrole oxide dramatically increases the level of intracellular reactive oxygen species (ROS) and the activity of NADPH oxidase. Moreover, manganese-dependent superoxide dismutase (MnSOD) activity was decreased significantly with safrole oxide treatment. Our study thus demonstrates that safrole oxide induces neuronal apoptosis through integrin beta4, ROS, NADPH, and MnSOD.

  15. Influence on uv radiation-induced oedemas of mice by therapeutical injection of nucleic acids and their elements

    Energy Technology Data Exchange (ETDEWEB)

    Hoenighaus, H

    1972-01-01

    The present paper examines the therapeutical effect of nucleic acids and their elements on increased capillary permeability of the skin of the mouse after UV-radiation. In case of intraperitoneal injection of the substances immediately after irradiation, Thymidin, Uridin, Adenosin, Prosplen, Laevadosin, Nucleton, Triadenyl, Adenosin 3',5'-cyclophosphat, and Aicorat showed a statistically significant prolongation of the latency periods compared with the control values. Since no therapeutical effects were seen using Cytidin, Cytosin, DNA, and Lacarnol, these were no longer applied during the following examinations. Thymidin, Adenosin, Uridin, Nucleton, Laevadosin, Triadenyl, and Aicorat showed also a statistically significant prolongation of the latency periods when intraperitoneally injected 2 hours after UV-irradiations. The latency period was only little prolonged when Prosplen and Adenosin 3',5'-cyclophosphat were used. For the therapeutical efficiency of the effective nucleosides and nucleotides the possibility of a repair of uv-induced damage in sense of a 'dark repair' was discussed with special interest. Some substances (Laevadosin, Nucleton, Triadenyl) were adjudged a special role in the stabilisation of the energy exchange because of the existence of high-energy compositions.

  16. Synaptic network activity induces neuronal differentiation of adult hippocampal precursor cells through BDNF signaling

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    Harish Babu

    2009-09-01

    Full Text Available Adult hippocampal neurogenesis is regulated by activity. But how do neural precursor cells in the hippocampus respond to surrounding network activity and translate increased neural activity into a developmental program? Here we show that long-term potential (LTP-like synaptic activity within a cellular network of mature hippocampal neurons promotes neuronal differentiation of newly generated cells. In co-cultures of precursor cells with primary hippocampal neurons, LTP-like synaptic plasticity induced by addition of glycine in Mg2+-free media for 5 min, produced synchronous network activity and subsequently increased synaptic strength between neurons. Furthermore, this synchronous network activity led to a significant increase in neuronal differentiation from the co-cultured neural precursor cells. When applied directly to precursor cells, glycine and Mg2+-free solution did not induce neuronal differentiation. Synaptic plasticity-induced neuronal differentiation of precursor cells was observed in the presence of GABAergic neurotransmission blockers but was dependent on NMDA-mediated Ca2+ influx. Most importantly, neuronal differentiation required the release of brain-derived neurotrophic factor (BDNF from the underlying substrate hippocampal neurons as well as TrkB receptor phosphorylation in precursor cells. This suggests that activity-dependent stem cell differentiation within the hippocampal network is mediated via synaptically evoked BDNF signaling.

  17. Detection of protonated non-Watson-Crick base pairs using electrospray ionization mass spectrometry.

    Science.gov (United States)

    Ishida, Riyoko; Iwahashi, Hideo

    2018-03-01

    Many studies have shown that protonated nucleic acid base pairs are involved in a wide variety of nucleic acid structures. However, little information is available on relative stability of hemiprotonated self- and non-self-dimers at monomer level. We used electrospray ionization mass spectrometry (ESI-MS) to evaluate the relative stability under various concentrations of hydrogen ion. These enable conjecture of the formation of protonated non-Watson-Crick base pairs based on DNA and RNA base sequence. In the present study, we observed that ESI-MS peaks corresponded to respective self-dimers for all examined nucleosides except for adenosine. Peak heights depended on the concentration of hydrogen ion. The ESI-MS peak heights of the hemiprotonated cytidine dimers and the hemiprotonated thymidine dimer sharply increased with increased concentration of hydrogen ion, suggesting direct participation of hydrogen ion in dimer formations. In ESI-MS measurements of the solutions containing adenosine, cytidine, thymidine and guanosine, we observed protonated cytidine-guanosine dimer (CH+-G) and protonated cytidine-thymidine dimer (CH+-T) in addition to hemiprotonated cytidine-cytidine dimer (CH+-C) with following relative peak height, (CH+-C) > (CH+-G) ≈ (CH+-T) > (CH+-A). Additionally, in the ESI-MS measurements of solutions containing adenosine, thymidine and guanosine, we observed a considerable amount of protonated adenosine-guanosine (AH+-G) and protonated adenosine-thymidine (AH+-T).

  18. Akt-dependent NF-κB activation is required for bile acids to rescue colon cancer cells from stress-induced apoptosis

    International Nuclear Information System (INIS)

    Shant, Jasleen; Cheng, Kunrong; Marasa, Bernard S.; Wang Jianying; Raufman, Jean-Pierre

    2009-01-01

    Conjugated secondary bile acids promote human colon cancer cell proliferation by activating EGF receptors (EGFR). We hypothesized that bile acid-induced EGFR activation also mediates cell survival by downstream Akt-regulated activation of NF-κB. Deoxycholyltaurine (DCT) treatment attenuated TNF-α-induced colon cancer cell apoptosis, and stimulated rapid and sustained NF-κB nuclear translocation and transcriptional activity (detected by NF-κB binding to an oligonucleotide consensus sequence and by activation of luciferase reporter gene constructs). Both DCT-induced NF-κB nuclear translocation and attenuation of TNF-α-stimulated apoptosis were dependent on EGFR activation. Inhibitors of nuclear translocation, proteosome activity, and IκBα kinase attenuated NF-κB transcriptional activity. Cell transfection with adenoviral vectors encoding a non-degradable IκBα 'super-repressor' blocked the actions of DCT on both NF-κB activation and TNF-α-induced apoptosis. Likewise, transfection with mutant akt and treatment with a chemical inhibitor of Akt attenuated effects of DCT on NF-κB transcriptional activity and TNF-α-induced apoptosis. Chemical inhibitors of Akt and NF-κB activation also attenuated DCT-induced rescue of H508 cells from ultraviolet radiation-induced apoptosis. Collectively, these observations indicate that, downstream of EGFR, bile acid-induced colon cancer cell survival is mediated by Akt-dependent NF-κB activation. These findings provide a mechanism whereby bile acids increase resistance of colon cancer to chemotherapy and radiation

  19. Cytoprotective effect of phloroglucinol on oxidative stress induced cell damage via catalase activation.

    Science.gov (United States)

    Kang, Kyoung Ah; Lee, Kyoung Hwa; Chae, Sungwook; Zhang, Rui; Jung, Myung Sun; Ham, Young Min; Baik, Jong Seok; Lee, Nam Ho; Hyun, Jin Won

    2006-02-15

    We investigated the cytoprotective effect of phloroglucinol, which was isolated from Ecklonia cava (brown alga), against oxidative stress induced cell damage in Chinese hamster lung fibroblast (V79-4) cells. Phloroglucinol was found to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, hydrogen peroxide (H(2)O(2)), hydroxy radical, intracellular reactive oxygen species (ROS), and thus prevented lipid peroxidation. As a result, phloroglucinol reduced H(2)O(2) induced apoptotic cells formation in V79-4 cells. In addition, phloroglucinol inhibited cell damage induced by serum starvation and radiation through scavenging ROS. Phloroglucinol increased the catalase activity and its protein expression. In addition, catalase inhibitor abolished the protective effect of phloroglucinol from H(2)O(2) induced cell damage. Furthermore, phloroglucinol increased phosphorylation of extracellular signal regulated kinase (ERK). Taken together, the results suggest that phloroglucinol protects V79-4 cells against oxidative damage by enhancing the cellular catalase activity and modulating ERK signal pathway. (c) 2005 Wiley-Liss, Inc.

  20. Transient Receptor Potential Vanilloid 4 Activation-Induced Increase in Glycine-Activated Current in Mouse Hippocampal Pyramidal Neurons

    Directory of Open Access Journals (Sweden)

    Mengwen Qi

    2018-02-01

    Full Text Available Background/Aims: Glycine plays an important role in regulating hippocampal inhibitory/ excitatory neurotransmission through activating glycine receptors (GlyRs and acting as a co-agonist of N-methyl-d-aspartate-type glutamate receptors. Activation of transient receptor potential vanilloid 4 (TRPV4 is reported to inhibit hippocampal A-type γ-aminobutyric acid receptor, a ligand-gated chloride ion channel. GlyRs are also ligand-gated chloride ion channels and this paper aimed to explore whether activation of TRPV4 could modulate GlyRs. Methods: Whole-cell patch clamp recording was employed to record glycine-activated current (IGly and Western blot was conducted to assess GlyRs subunits protein expression. Results: Application of TRPV4 agonist (GSK1016790A or 5,6-EET increased IGly in mouse hippocampal CA1 pyramidal neurons. This action was blocked by specific antagonists of TRPV4 (RN-1734 or HC-067047 and GlyR (strychnine, indicating that activation of TRPV4 increases strychnine-sensitive GlyR function in mouse hippocampal pyramidal neurons. GSK1016790A-induced increase in IGly was significantly attenuated by protein kinase C (PKC (BIM II or D-sphingosine or calcium/calmodulin-dependent protein kinase II (CaMKII (KN-62 or KN-93 antagonists but was unaffected by protein kinase A or protein tyrosine kinase antagonists. Finally, hippocampal protein levels of GlyR α1 α2, α3 and β subunits were not changed by treatment with GSK1016790A for 30 min or 1 h, but GlyR α2, α3 and β subunits protein levels increased in mice that were intracerebroventricularly (icv. injected with GSK1016790A for 5 d. Conclusion: Activation of TRPV4 increases GlyR function and expression, and PKC and CaMKII signaling pathways are involved in TRPV4 activation-induced increase in IGly. This study indicates that GlyRs may be effective targets for TRPV4-induced modulation of hippocampal inhibitory neurotransmission.

  1. Milrinone-Induced Postconditioning Requires Activation of Mitochondrial Ca2+-sensitive Potassium (mBKCa) Channels

    NARCIS (Netherlands)

    Behmenburg, Friederike; Trefz, Lara; Dorsch, Marianne; Ströthoff, Martin; Mathes, Alexander; Raupach, Annika; Heinen, André; Hollmann, Markus W.; Berger, Marc M.; Huhn, Ragnar

    2017-01-01

    Cardioprotection by postconditioning requires activation of mitochondrial large-conductance Ca2+-sensitive potassium (mBKCa) channels. The involvement of these channels in milrinone-induced postconditioning is unknown. The authors determined whether cardioprotection by milrinone-induced

  2. Immunological Demyelination Triggers Macrophage/Microglial Cells Activation without Inducing Astrogliosis

    Directory of Open Access Journals (Sweden)

    Frank Cloutier

    2013-01-01

    Full Text Available The glial scar formed by reactive astrocytes and axon growth inhibitors associated with myelin play important roles in the failure of axonal regeneration following central nervous system (CNS injury. Our laboratory has previously demonstrated that immunological demyelination of the CNS facilitates regeneration of severed axons following spinal cord injury. In the present study, we evaluate whether immunological demyelination is accompanied with astrogliosis. We compared the astrogliosis and macrophage/microglial cell responses 7 days after either immunological demyelination or a stab injury to the dorsal funiculus. Both lesions induced a strong activated macrophage/microglial cells response which was significantly higher within regions of immunological demyelination. However, immunological demyelination regions were not accompanied by astrogliosis compared to stab injury that induced astrogliosis which extended several millimeters above and below the lesions, evidenced by astroglial hypertrophy, formation of a glial scar, and upregulation of intermediate filaments glial fibrillary acidic protein (GFAP. Moreover, a stab or a hemisection lesion directly within immunological demyelination regions did not induced astrogliosis within the immunological demyelination region. These results suggest that immunological demyelination creates a unique environment in which astrocytes do not form a glial scar and provides a unique model to understand the putative interaction between astrocytes and activated macrophage/microglial cells.

  3. Protection against methamphetamine-induced neurotoxicity to neostriatal dopaminergic neurons by adenosine receptor activation.

    Science.gov (United States)

    Delle Donne, K T; Sonsalla, P K

    1994-12-01

    Methamphetamine (METH)-induced neurotoxicity to nigrostriatal dopaminergic neurons in experimental animals appears to have a glutamatergic component because blockade of N-methyl-D-aspartate receptors prevents the neuropathologic consequences. Because adenosine affords neuroprotection against various forms of glutamate-mediated neuronal damage, the present studies were performed to investigate whether adenosine plays a protective role in METH-induced toxicity. METH-induced decrements in neostriatal dopamine content and tyrosine hydroxylase activity in mice were potentiated by concurrent treatment with caffeine, a nonselective adenosine antagonist that blocks both A1 and A2 adenosine receptors. In contrast, chronic treatment of mice with caffeine through their drinking water for 4 weeks, which increased the number of adenosine A1 receptors in the neostriatum and frontal cortex, followed by drug washout, prevented the neurochemical changes produced by the treatment of mice with METH treatment. In contrast, this treatment did not prevent 1-methyl-4-phenyl-1,2,3,6- tetrahydropyridine-induced dopaminergic neurotoxicity. Furthermore, concurrent administration of cyclopentyladenosine, an adenosine A1 receptor agonist, attenuated the METH-induced neurochemical changes. This protection by cyclopentyladenosine was blocked by cyclopentyltheophylline, an A1 receptor antagonist. These results indicate that activation of A1 receptors can protect against METH-induced neurotoxicity in mice.

  4. Activation of Transient Receptor Potential Melastatin Subtype 8 Attenuates Cold-Induced Hypertension Through Ameliorating Vascular Mitochondrial Dysfunction.

    Science.gov (United States)

    Xiong, Shiqiang; Wang, Bin; Lin, Shaoyang; Zhang, Hexuan; Li, Yingsha; Wei, Xing; Cui, Yuanting; Wei, Xiao; Lu, Zongshi; Gao, Peng; Li, Li; Zhao, Zhigang; Liu, Daoyan; Zhu, Zhiming

    2017-08-02

    Environmental cold-induced hypertension is common, but how to treat cold-induced hypertension remains an obstacle. Transient receptor potential melastatin subtype 8 (TRPM8) is a mild cold-sensing nonselective cation channel that is activated by menthol. Little is known about the effect of TRPM8 activation by menthol on mitochondrial Ca 2+ homeostasis and the vascular function in cold-induced hypertension. Primary vascular smooth muscle cells from wild-type or Trpm8 -/- mice were cultured. In vitro, we confirmed that sarcoplasmic reticulum-resident TRPM8 participated in the regulation of cellular and mitochondrial Ca 2+ homeostasis in the vascular smooth muscle cells. TRPM8 activation by menthol antagonized angiotensin II induced mitochondrial respiratory dysfunction and excess reactive oxygen species generation by preserving pyruvate dehydrogenase activity, which hindered reactive oxygen species-triggered Ca 2+ influx and the activation of RhoA/Rho kinase pathway. In vivo, long-term noxious cold stimulation dramatically increased vasoconstriction and blood pressure. The activation of TRPM8 by dietary menthol inhibited vascular reactive oxygen species generation, vasoconstriction, and lowered blood pressure through attenuating excessive mitochondrial reactive oxygen species mediated the activation of RhoA/Rho kinase in a TRPM8-dependent manner. These effects of menthol were further validated in angiotensin II-induced hypertensive mice. Long-term dietary menthol treatment targeting and preserving mitochondrial function may represent a nonpharmaceutical measure for environmental noxious cold-induced hypertension. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  5. Impurities and evaluation of induced activity of CVI SiCf/SiC composites

    International Nuclear Information System (INIS)

    Noda, Tetsuji; Fujita, Mitsutane; Araki, Hiroshi; Kohyama, Akira

    2000-01-01

    Impurity of SiC f /SiC composites prepared by CVI was analyzed by neutron activation analysis and glow discharge mass spectrometry. The evaluation of the induced activity of the composites based on the chemical compositions was made using a simulation calculation for fusion reactor blanket. Impurities of 35 elements were detected in the composites. However, the total concentration of metallic impurities was below 20 mass ppm. The analyses of induced activity of the composites show that the dose rate decreases by about six orders of magnitude in a day after the shutdown. It is recommended that the purification of SiC composites, especially reduction of Fe and Ni contents, is necessary to reduce the activity to satisfy the limit of remote handling recycling after several 10 years cooling of fusion reactors

  6. Carnosine: effect on aging-induced increase in brain regional monoamine oxidase-A activity.

    Science.gov (United States)

    Banerjee, Soumyabrata; Poddar, Mrinal K

    2015-03-01

    Aging is a natural biological process associated with several neurological disorders along with the biochemical changes in brain. Aim of the present investigation is to study the effect of carnosine (0.5-2.5μg/kg/day, i.t. for 21 consecutive days) on aging-induced changes in brain regional (cerebral cortex, hippocampus, hypothalamus and pons-medulla) mitochondrial monoamine oxidase-A (MAO-A) activity with its kinetic parameters. The results of the present study are: (1) The brain regional mitochondrial MAO-A activity and their kinetic parameters (except in Km of pons-medulla) were significantly increased with the increase of age (4-24 months), (2) Aging-induced increase of brain regional MAO-A activity including its Vmax were attenuated with higher dosages of carnosine (1.0-2.5μg/kg/day) and restored toward the activity that observed in young, though its lower dosage (0.5μg/kg/day) were ineffective in these brain regional MAO-A activity, (3) Carnosine at higher dosage in young rats, unlike aged rats significantly inhibited all the brain regional MAO-A activity by reducing their only Vmax excepting cerebral cortex, where Km was also significantly enhanced. These results suggest that carnosine attenuated the aging-induced increase of brain regional MAO-A activity by attenuating its kinetic parameters and restored toward the results of MAO-A activity that observed in corresponding brain regions of young rats. Copyright © 2014 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

  7. Activated human mast cells induce LOX-1-specific scavenger receptor expression in human monocyte-derived macrophages.

    Directory of Open Access Journals (Sweden)

    Mervi Alanne-Kinnunen

    Full Text Available Activated mast cells in atherosclerotic lesions degranulate and release bioactive compounds capable of regulating atherogenesis. Here we examined the ability of activated human primary mast cells to regulate the expression of the major scavenger receptors in cultured human primary monocyte-derived macrophages (HMDMs.Components released by immunologically activated human primary mast cells induced a transient expression of lectin-like oxidized LDL receptor (LOX-1 mRNA in HMDMs, while the expression of two other scavenger receptors, MSR1 and CD36, remained unaffected. The LOX-1-inducing secretory components were identified as histamine, tumor necrosis factor alpha (TNF-α, and transforming growth factor beta (TGF-β1, which exhibited a synergistic effect on LOX-1 mRNA expression. Histamine induced a transient expression of LOX-1 protein. Mast cell -induced increase in LOX-1 expression was not associated with increased uptake of oxidized LDL by the macrophages.Mast cell-derived histamine, TNF-α, and TGF-β1 act in concert to induce a transient increase in LOX-1 expression in human primary monocyte-derived macrophages. The LOX-1-inducing activity potentially endows mast cells a hitherto unrecognized role in the regulation of innate immune reactions in atherogenesis.

  8. Evaluation of the rotenone-induced activation of the Nrf2 pathway in a neuronal model derived from human induced pluripotent stem cells.

    Science.gov (United States)

    Zagoura, Dimitra; Canovas-Jorda, David; Pistollato, Francesca; Bremer-Hoffmann, Susanne; Bal-Price, Anna

    2017-06-01

    Human induced pluripotent stem cells (hiPSCs) are considered as a powerful tool for drug and chemical screening and development of new in vitro testing strategies in the field of toxicology, including neurotoxicity evaluation. These cells are able to expand and efficiently differentiate into different types of neuronal and glial cells as well as peripheral neurons. These human cells-based neuronal models serve as test systems for mechanistic studies on different pathways involved in neurotoxicity. One of the well-known mechanisms that are activated by chemically-induced oxidative stress is the Nrf2 signaling pathway. Therefore, in the current study, we evaluated whether Nrf2 signaling machinery is expressed in human induced pluripotent stem cells (hiPSCs)-derived mixed neuronal/glial culture and if so whether it becomes activated by rotenone-induced oxidative stress mediated by complex I inhibition of mitochondrial respiration. Rotenone was found to induce the activation of Nrf2 signaling particularly at the highest tested concentration (100 nM), as shown by Nrf2 nuclear translocation and the up-regulation of the Nrf2-downstream antioxidant enzymes, NQO1 and SRXN1. Interestingly, exposure to rotenone also increased the number of astroglial cells in which Nrf2 activation may play an important role in neuroprotection. Moreover, rotenone caused cell death of dopaminergic neurons since a decreased percentage of tyrosine hydroxylase (TH + ) cells was observed. The obtained results suggest that hiPSC-derived mixed neuronal/glial culture could be a valuable in vitro human model for the establishment of neuronal specific assays in order to link Nrf2 pathway activation (biomarker of oxidative stress) with additional neuronal specific readouts that could be applied to in vitro neurotoxicity evaluation. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. Antibody Affinity Maturation in Fishes—Our Current Understanding

    Directory of Open Access Journals (Sweden)

    Brad G. Magor

    2015-07-01

    Full Text Available It has long been believed that fish lack antibody affinity maturation, in part because they were thought to lack germinal centers. Recent research done on sharks and bony fishes indicates that these early vertebrates are able to affinity mature their antibodies. This article reviews the functionality of the fish homologue of the immunoglobulin (Ig mutator enzyme activation-induced cytidine deaminase (AID. We also consider the protein and molecular evidence for Ig somatic hypermutation and antibody affinity maturation. In the context of recent evidence for a putative proto-germinal center in fishes we propose some possible reasons that observed affinity maturation in fishes often seems lacking and propose future work that might shed further light on this process in fishes.

  10. Inhibitory effects of andrographolide on activated macrophages and adjuvant-induced arthritis.

    Science.gov (United States)

    Gupta, Swati; Mishra, Kamla Prasad; Singh, Shashi Bala; Ganju, Lilly

    2018-04-01

    Andrographolide, a diterpenoid lactone obtained from plant Andrographis paniculata, is used in South Asian countries to relieve various inflammatory symptoms. To study the effects of this agent, the impact of andrographolide on production of inflammatory mediators were delineated in mouse peritoneal macrophages (PMϕ). Inflammatory mediators like nitric oxide (NO), tumor necrosis factor (TNF)-α, interleukin-6 and related molecular mechanisms of andrographolide-mediated inhibition of enzymes/transcription factors were studied. In addition, the in vivo anti-inflammatory activity of andrographolide was evaluated in an adjuvant-induced arthritis rat model. The results indicated that andrographolide clearly inhibited the production of NO and TNF-α in lipopolysaccharide-activated PMϕ in a dose-related manner. Immunoblot analyses revealed that andrographolide suppressed activation of both inducible NO synthase and cyclo-oxygenase-2 by directly targeting nuclear transcription factor (NF)-κB. Complete Freund's Adjuvant-induced paw edema in rats was also significantly inhibited by andrographolide treatment. From the data, we concluded that andrographolide imparted anti-inflammatory effects by suppressing two key inflammatory enzymes and a signaling pathway that mediates expression of variety of inflammatory cytokines/agents in situ. It is plausible that eventually, after further toxicologic characterization, andrographolide might be useful as a drug for the clinical treatment of various inflammatory diseases like rheumatoid arthritis or diseases associated with joint pain.

  11. Dendritic cell activation and maturation induced by recombinant calreticulin fragment 39-272.

    Science.gov (United States)

    Li, Yue; Zeng, Xiaoli; He, Lijuan; Yuan, Hui

    2015-01-01

    Dendritic cells (DC) are the most potent antigen-presenting cells for initiating immune responses. DC maturation can be induced by exposing of immature DC to pathogen products or pro-inflammatory factor, which dramatically enhances the ability of DC to activate Ag-specific T cells. In this study, a recombinant calreticulin fragment 39-272 (rCRT/39-272) covering the lectin-like N domain and partial P domain of murine CRT has been expressed and purified in Escherichia coli. Functional analysis studies revealed that rCRT/39-272 has potent immunostimulatory activities in both activating human monocytes and B cells to secrete cytokines. rCRT/39-272 can drive the activation of bone marrow derived DC in TLR4/CD14 dependent way, as indicated by secretion of cytokines IL-12/IL-23 (p40) and IL-1β. Exposure of DC to rCRT/39-272 induces P-Akt, suggesting that rCRT/39-272 induces maturation of DC through PI3K/Akt signaling pathway. The results suggest that soluble rCRT/39-272 is a potent stimulatory agent to DC maturation in TLR4/CD14 and PI3K/Akt dependent pathway. It may play important roles in initiating cellular immunity in vivo and the T cell response in vitro. Thus it could be used for study of DC-based tumor vaccines.

  12. CSK negatively regulates nerve growth factor induced neural differentiation and augments AKT kinase activity

    International Nuclear Information System (INIS)

    Dey, Nandini; Howell, Brian W.; De, Pradip K.; Durden, Donald L.

    2005-01-01

    Src family kinases are involved in transducing growth factor signals for cellular differentiation and proliferation in a variety of cell types. The activity of all Src family kinases (SFKs) is controlled by phosphorylation at their C-terminal 527-tyrosine residue by C-terminal SRC kinase, CSK. There is a paucity of information regarding the role of CSK and/or specific Src family kinases in neuronal differentiation. Pretreatment of PC12 cells with the Src family kinase inhibitor, PP1, blocked NGF-induced activation of SFKs and obliterated neurite outgrowth. To confirm a role for CSK and specific isoforms of SFKs in neuronal differentiation, we overexpressed active and catalytically dead CSK in the rat pheochromocytoma cell line, PC12. CSK overexpression caused a profound inhibition of NGF-induced activation of FYN, YES, RAS, and ERK and inhibited neurite outgrowth, NGF-stimulated integrin-directed migration and blocked the NGF-induced conversion of GDP-RAC to its GTP-bound active state. CSK overexpression markedly augmented the activation state of AKT following NGF stimulation. In contrast, kinase-dead CSK augmented the activation of FYN, RAS, and ERK and increased neurite outgrowth. These data suggest a distinct requirement for CSK in the regulation of NGF/TrkA activation of RAS, RAC, ERK, and AKT via the differential control of SFKs in the orchestration of neuronal differentiation

  13. Phenylarsine Oxide Inhibits the Fusicoccin-Induced Activation of Plasma Membrane H+-ATPase1

    Science.gov (United States)

    Olivari, Claudio; Albumi, Cristina; Pugliarello, Maria Chiara; De Michelis, Maria Ida

    2000-01-01

    To investigate the mechanism by which fusicoccin (FC) induces the activation of the plasma membrane (PM) H+-ATPase, we used phenylarsine oxide (PAO), a known inhibitor of protein tyrosine-phosphatases. PAO was supplied in vivo in the absence or presence of FC to radish (Raphanus sativus L.) seedlings and cultured Arabidopsis cells prior to PM extraction. Treatment with PAO alone caused a slight decrease of PM H+-ATPase activity and, in radish, a decrease of PM-associated 14-3-3 proteins. When supplied prior to FC, PAO drastically inhibited FC-induced activation of PM H+-ATPase, FC binding to the PM, and the FC-induced increase of the amount of 14-3-3 associated with the PM. On the contrary, PAO was completely ineffective on all of the above-mentioned parameters when supplied after FC. The H+-ATPase isolated from PAO-treated Arabidopsis cells maintained the ability to respond to FC if supplied with exogenous, nonphosphorylated 14-3-3 proteins. Altogether, these results are consistent with a model in which the dephosphorylated state of tyrosine residues of a protein(s), such as 14-3-3 protein, is required to permit FC-induced association between the 14-3-3 protein and the PM H+-ATPase. PMID:10677439

  14. Inhibition of matrix metalloproteinase-9 activity by doxycycline ameliorates RANK ligand-induced osteoclast differentiation in vitro and in vivo

    International Nuclear Information System (INIS)

    Franco, Gilson C.N.; Kajiya, Mikihito; Nakanishi, Tadashi; Ohta, Kouji; Rosalen, Pedro L.; Groppo, Francisco C.; Ernst, Cory W.O.; Boyesen, Janie L.; Bartlett, John D.; Stashenko, Philip; Taubman, Martin A.; Kawai, Toshihisa

    2011-01-01

    Tetracycline antibiotics, including doxycycli/e (DOX), have been used to treat bone resorptive diseases, partially because of their activity to suppress osteoclastogenesis induced by receptor activator of nuclear factor kappa B ligand (RANKL). However, their precise inhibitory mechanism remains unclear. Therefore, the present study examined the effect of Dox on osteoclastogenesis signaling induced by RANKL, both in vitro and in vivo. Although Dox inhibited RANKL-induced osteoclastogenesis and down-modulated the mRNA expression of functional osteoclast markers, including tartrate-resistant acid phosphatase (TRAP) and cathepsin K, Dox neither affected RANKL-induced MAPKs phosphorylation nor NFATc1 gene expression in RAW264.7 murine monocytic cells. Gelatin zymography and Western blot analyses showed that Dox down-regulated the enzyme activity of RANKL-induced MMP-9, but without affecting its protein expression. Furthermore, MMP-9 enzyme inhibitor also attenuated both RANKL-induced osteoclastogenesis and up-regulation of TRAP and cathepsin K mRNA expression, indicating that MMP-9 enzyme action is engaged in the promotion of RANKL-induced osteoclastogenesis. Finally, Dox treatment abrogated RANKL-induced osteoclastogenesis and TRAP activity in mouse calvaria along with the suppression of MMP9 enzyme activity, again without affecting the expression of MMP9 protein. These findings suggested that Dox inhibits RANKL-induced osteoclastogenesis by its inhibitory effect on MMP-9 enzyme activity independent of the MAPK-NFATc1 signaling cascade.

  15. Resveratrol protects vascular endothelial cells from high glucose-induced apoptosis through inhibition of NADPH oxidase activation-driven oxidative stress.

    Science.gov (United States)

    Chen, Feng; Qian, Li-Hua; Deng, Bo; Liu, Zhi-Min; Zhao, Ying; Le, Ying-Ying

    2013-09-01

    Hyperglycemia-induced oxidative stress has been implicated in diabetic vascular complications in which NADPH oxidase is a major source of reactive oxygen species (ROS) generation. Resveratrol is a naturally occurring polyphenol, which has vasoprotective effects in diabetic animal models and inhibits high glucose (HG)-induced oxidative stress in endothelial cells. We aimed to examine whether HG-induced NADPH oxidase activation and ROS production contribute to glucotoxicity to endothelial cells and the effect of resveratrol on glucotoxicity. Using a murine brain microvascular endothelial cell line bEnd3, we found that NADPH oxidase inhibitor (apocynin) and resveratrol both inhibited HG-induced endothelial cell apoptosis. HG-induced elevation of NADPH oxidase activity and production of ROS were inhibited by apocynin, suggesting that HG induces endothelial cell apoptosis through NADPH oxidase-mediated ROS production. Mechanistic studies revealed that HG upregulated NADPH oxidase subunit Nox1 but not Nox2, Nox4, and p22(phox) expression through NF-κB activation, which resulted in elevation of NADPH oxidase activity and consequent ROS production. Resveratrol prevented HG-induced endothelial cell apoptosis through inhibiting HG-induced NF-κB activation, NADPH oxidase activity elevation, and ROS production. HG induces endothelial cell apoptosis through NF-κB/NADPH oxidase/ROS pathway, which was inhibited by resveratrol. Our findings provide new potential therapeutic targets against brain vascular complications of diabetes. © 2013 John Wiley & Sons Ltd.

  16. Inhibition of matrix metalloproteinase-9 activity by doxycycline ameliorates RANK ligand-induced osteoclast differentiation in vitro and in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Franco, Gilson C.N. [Department of Immunology, Forsyth Institute, Cambridge, MA (United States); Department of Pharmacology, FOP/UNICAMP, Piracicaba, SP (Brazil); Kajiya, Mikihito [Department of Immunology, Forsyth Institute, Cambridge, MA (United States); Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA (United States); Nakanishi, Tadashi [Department of Immunology, Forsyth Institute, Cambridge, MA (United States); Ohta, Kouji [Department of Immunology, Forsyth Institute, Cambridge, MA (United States); Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA (United States); Rosalen, Pedro L.; Groppo, Francisco C. [Department of Pharmacology, FOP/UNICAMP, Piracicaba, SP (Brazil); Ernst, Cory W.O.; Boyesen, Janie L. [Department of Immunology, Forsyth Institute, Cambridge, MA (United States); Bartlett, John D.; Stashenko, Philip [Department of Cytokine Biology, Forsyth Institute, Cambridge, MA (United States); Taubman, Martin A. [Department of Immunology, Forsyth Institute, Cambridge, MA (United States); Kawai, Toshihisa, E-mail: tkawai@forsyth.org [Department of Immunology, Forsyth Institute, Cambridge, MA (United States); Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA (United States)

    2011-06-10

    Tetracycline antibiotics, including doxycycli/e (DOX), have been used to treat bone resorptive diseases, partially because of their activity to suppress osteoclastogenesis induced by receptor activator of nuclear factor kappa B ligand (RANKL). However, their precise inhibitory mechanism remains unclear. Therefore, the present study examined the effect of Dox on osteoclastogenesis signaling induced by RANKL, both in vitro and in vivo. Although Dox inhibited RANKL-induced osteoclastogenesis and down-modulated the mRNA expression of functional osteoclast markers, including tartrate-resistant acid phosphatase (TRAP) and cathepsin K, Dox neither affected RANKL-induced MAPKs phosphorylation nor NFATc1 gene expression in RAW264.7 murine monocytic cells. Gelatin zymography and Western blot analyses showed that Dox down-regulated the enzyme activity of RANKL-induced MMP-9, but without affecting its protein expression. Furthermore, MMP-9 enzyme inhibitor also attenuated both RANKL-induced osteoclastogenesis and up-regulation of TRAP and cathepsin K mRNA expression, indicating that MMP-9 enzyme action is engaged in the promotion of RANKL-induced osteoclastogenesis. Finally, Dox treatment abrogated RANKL-induced osteoclastogenesis and TRAP activity in mouse calvaria along with the suppression of MMP9 enzyme activity, again without affecting the expression of MMP9 protein. These findings suggested that Dox inhibits RANKL-induced osteoclastogenesis by its inhibitory effect on MMP-9 enzyme activity independent of the MAPK-NFATc1 signaling cascade.

  17. Monocytes can be induced by lipopolysaccharide-triggered T lymphocytes to express functional factor VII/VIIa protease activity

    OpenAIRE

    1984-01-01

    In the present study we demonstrate that human monocytes can be induced by the model stimulus, lipopolysaccharide (LPS), to produce and assemble on their surface functional Factor VII/VIIa. This protease was not induced in relatively purified monocytes alone following exposure to LPS; but was induced in the presence of Leu-3a positive helper/inducer T cells. The Factor VII/VIIa protease activity represented 35-40% of the potential initiating activity for the extrinsic coagulation pathway and ...

  18. Classical and alternative macrophage activation in the lung following ozone-induced oxidative stress

    Energy Technology Data Exchange (ETDEWEB)

    Sunil, Vasanthi R., E-mail: sunilva@pharmacy.rutgers.edu [Department of Pharmacology and Toxicology, Rutgers University, Ernest Mario School of Pharmacy, Piscataway, NJ 08854 (United States); Patel-Vayas, Kinal; Shen, Jianliang [Department of Pharmacology and Toxicology, Rutgers University, Ernest Mario School of Pharmacy, Piscataway, NJ 08854 (United States); Laskin, Jeffrey D. [Department of Environmental and Occupational Medicine, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Piscataway, NJ (United States); Laskin, Debra L. [Department of Pharmacology and Toxicology, Rutgers University, Ernest Mario School of Pharmacy, Piscataway, NJ 08854 (United States)

    2012-09-01

    Ozone is a pulmonary irritant known to cause oxidative stress, inflammation and tissue injury. Evidence suggests that macrophages play a role in the pathogenic response; however, their contribution depends on the mediators they encounter in the lung which dictate their function. In these studies we analyzed the effects of ozone-induced oxidative stress on the phenotype of alveolar macrophages (AM). Exposure of rats to ozone (2 ppm, 3 h) resulted in increased expression of 8-hydroxy-2′-deoxyguanosine (8-OHdG), as well as heme oxygenase-1 (HO-1) in AM. Whereas 8-OHdG was maximum at 24 h, expression of HO-1 was biphasic increasing after 3 h and 48–72 h. Cleaved caspase-9 and beclin-1, markers of apoptosis and autophagy, were also induced in AM 24 h post-ozone. This was associated with increased bronchoalveolar lavage protein and cells, as well as matrix metalloproteinase (MMP)-2 and MMP-9, demonstrating alveolar epithelial injury. Ozone intoxication resulted in biphasic activation of the transcription factor, NFκB. This correlated with expression of monocyte chemotactic protein‐1, inducible nitric oxide synthase and cyclooxygenase‐2, markers of proinflammatory macrophages. Increases in arginase-1, Ym1 and galectin-3 positive anti-inflammatory/wound repair macrophages were also observed in the lung after ozone inhalation, beginning at 24 h (arginase-1, Ym1), and persisting for 72 h (galectin-3). This was associated with increased expression of pro-surfactant protein-C, a marker of Type II cell proliferation and activation, important steps in wound repair. These data suggest that both proinflammatory/cytotoxic and anti-inflammatory/wound repair macrophages are activated early in the response to ozone-induced oxidative stress and tissue injury. -- Highlights: ► Lung macrophages are highly sensitive to ozone induced oxidative stress. ► Ozone induces autophagy and apoptosis in lung macrophages. ► Proinflammatory and wound repair macrophages are activated

  19. Mitochondria related peptide MOTS-c suppresses ovariectomy-induced bone loss via AMPK activation

    Energy Technology Data Exchange (ETDEWEB)

    Ming, Wei, E-mail: weiming@xiyi.edu.cn [State Key Laboratory of Cancer Biology, Department of Pharmacogenomics, Fourth Military Medical University, Xi’an 710032 (China); Department of Pharmacology, Xi’an Medical University, Xi’an 710021 (China); Lu, Gan, E-mail: leonming99@163.com [Department of Gynecology of Shaanxi Provincial People’s Hospital, Xi’an, 710068 (China); Xin, Sha, E-mail: 248967979@qq.com [Institute of Orthopedic Surgery, Xijing Hospital, Fourth Military Medical University, Xi’an 710032 (China); Huanyu, Lu, E-mail: 2366927258@qq.com [Department of Occupational and Environmental Health and the Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Fourth Military Medical University, Xi’an 710032 (China); Yinghao, Jiang, E-mail: jiangyh@fmmu.edu.cn [State Key Laboratory of Cancer Biology, Department of Pharmacogenomics, Fourth Military Medical University, Xi’an 710032 (China); Xiaoying, Lei, E-mail: leixiaoy@fmmu.edu.cn [State Key Laboratory of Cancer Biology, Department of Pharmacogenomics, Fourth Military Medical University, Xi’an 710032 (China); Chengming, Xu, E-mail: chengmingxu@yeah.net [State Key Laboratory of Cancer Biology, Department of Pharmacogenomics, Fourth Military Medical University, Xi’an 710032 (China); Banjun, Ruan, E-mail: running@163.com [State Key Laboratory of Cancer Biology, Department of Pharmacogenomics, Fourth Military Medical University, Xi’an 710032 (China); Li, Wang, E-mail: wanglifw@fmmu.edu.cn [State Key Laboratory of Cancer Biology, Department of Pharmacogenomics, Fourth Military Medical University, Xi’an 710032 (China); and others

    2016-08-05

    Therapeutic targeting bone loss has been the focus of the study in osteoporosis. The present study is intended to evaluate whether MOTS-c, a novel mitochondria related 16 aa peptide, can protect mice from ovariectomy-induced osteoporosis. After ovary removal, the mice were injected with MOTS-c at a dose of 5 mg/kg once a day for 12 weeks. Our results showed that MOTS-c treatment significantly alleviated bone loss, as determined by micro-CT examination. Mechanistically, we found that the receptor activator of nuclear factor-κB ligand (RANKL) induced osteoclast differentiation was remarkably inhibited by MOTS-c. Moreover, MOTS-c increased phosphorylated AMPK levels, and compound C, an AMPK inhibitor, could partially abrogate the effects of the MOTS-c on osteoclastogenesis. Thus, our findings provide evidence that MOTS-c may exert as an inhibitor of osteoporosis via AMPK dependent inhibition of osteoclastogenesis. -- Highlights: •MOTS-c decreases OVX-induced bone loss in vivo. •MOTS-c inhibits RANKL-induced osteoclast formation. •MOTS-c inhibits RANKL-induced osteoclast-specific gene expression. •MOTS-c represses osteoclast differentiation via the activation of AMPK.

  20. Mitochondria related peptide MOTS-c suppresses ovariectomy-induced bone loss via AMPK activation

    International Nuclear Information System (INIS)

    Ming, Wei; Lu, Gan; Xin, Sha; Huanyu, Lu; Yinghao, Jiang; Xiaoying, Lei; Chengming, Xu; Banjun, Ruan; Li, Wang

    2016-01-01

    Therapeutic targeting bone loss has been the focus of the study in osteoporosis. The present study is intended to evaluate whether MOTS-c, a novel mitochondria related 16 aa peptide, can protect mice from ovariectomy-induced osteoporosis. After ovary removal, the mice were injected with MOTS-c at a dose of 5 mg/kg once a day for 12 weeks. Our results showed that MOTS-c treatment significantly alleviated bone loss, as determined by micro-CT examination. Mechanistically, we found that the receptor activator of nuclear factor-κB ligand (RANKL) induced osteoclast differentiation was remarkably inhibited by MOTS-c. Moreover, MOTS-c increased phosphorylated AMPK levels, and compound C, an AMPK inhibitor, could partially abrogate the effects of the MOTS-c on osteoclastogenesis. Thus, our findings provide evidence that MOTS-c may exert as an inhibitor of osteoporosis via AMPK dependent inhibition of osteoclastogenesis. -- Highlights: •MOTS-c decreases OVX-induced bone loss in vivo. •MOTS-c inhibits RANKL-induced osteoclast formation. •MOTS-c inhibits RANKL-induced osteoclast-specific gene expression. •MOTS-c represses osteoclast differentiation via the activation of AMPK.

  1. Mechanism of interaction of the antileukemic drug cytosine arabinoside with aromatic peptides: role of sugar conformation and peptide backbone.

    Science.gov (United States)

    Datta, G; Hosur, R V; Verma, N C; Khetrapal, C L; Gurnani, S

    1989-01-01

    Interaction of the antileukemic drugs, cytosine-arabinoside (Ara-C) and adenosine-arabinoside (Ara-A) and a structural analogue, cytidine, with aromatic dipeptides has been studied by fluorescence and NMR spectroscopy. Ara-C and cytidine bind tryptophanyl and histidyl dipeptides but not tyrosyl dipeptides, while Ara-A does not bind to any of them. Both studies indicate association involving stacking of aromatic moieties. NMR spectra also indicate a protonation of the histidine moiety by Ara-C. In case of cytidine, the chemical shifts observed on binding to His-Phe imply that the backbone protons of the dipeptide participate in the binding. The conformation of the sugar and the base seem to play a very important role in the binding phenomenon as three similar molecules, Ara-C, Ara-A and cytidine bind in totally different ways.

  2. Cyclopentenyl cytosine has biological and anti-tumour activity, but does not enhance the efficacy of gemcitabine and radiation in two animal tumour models

    NARCIS (Netherlands)

    van Bree, Chris; Barten-van Rijbroek, Angeliqué D.; Leen, René; Rodermond, Hans M.; van Kuilenburg, André B. P.; Kal, Henk B.

    2009-01-01

    Cyclopentenyl cytosine (CPEC), targetting the de novo biosynthesis of cytidine triphosphate (CTP), increases the cytotoxicity of gemcitabine (2',2'-difluoro-2'-deoxycytidine, dFdC) alone and in combination with irradiation in several human tumour cells in vitro. We investigated whether OPEC enhances

  3. Nucleotide metabolism in Lactococcus lactis: Salvage pathways of exogenous pyrimidines

    DEFF Research Database (Denmark)

    Martinussen, Jan; Andersen, Paal Skytt; Hammer, Karin

    1994-01-01

    By measuring enzyme activities in crude extracts and studying the effect of toxic analogs (5-fluoropyrimidines) on cell growth, the metabolism of pyrimidines in Lactococcus lactis was analyzed. Pathways by which uracil, uridine, deoxyuridine, cytidine, and deoxycytidine are metabolized in L. lact...

  4. A Taiwanese Propolis Derivative Induces Apoptosis through Inducing Endoplasmic Reticular Stress and Activating Transcription Factor-3 in Human Hepatoma Cells

    Directory of Open Access Journals (Sweden)

    Fat-Moon Suk

    2013-01-01

    Full Text Available Activating transcription factor-(ATF- 3, a stress-inducible transcription factor, is rapidly upregulated under various stress conditions and plays an important role in inducing cancer cell apoptosis. NBM-TP-007-GS-002 (GS-002 is a Taiwanese propolin G (PPG derivative. In this study, we examined the antitumor effects of GS-002 in human hepatoma Hep3B and HepG2 cells in vitro. First, we found that GS-002 significantly inhibited cell proliferation and induced cell apoptosis in dose-dependent manners. Several main apoptotic indicators were found in GS-002-treated cells, such as the cleaved forms of caspase-3, caspase-9, and poly(ADP-ribose polymerase (PARP. GS-002 also induced endoplasmic reticular (ER stress as evidenced by increases in ER stress-responsive proteins including glucose-regulated protein 78 (GRP78, growth arrest- and DNA damage-inducible gene 153 (GADD153, phosphorylated eukaryotic initiation factor 2α (eIF2α, phosphorylated protein endoplasmic-reticular-resident kinase (PERK, and ATF-3. The induction of ATF-3 expression was mediated by mitogen-activated protein kinase (MAPK signaling pathways in GS-002-treated cells. Furthermore, we found that GS-002 induced more cell apoptosis in ATF-3-overexpressing cells. These results suggest that the induction of apoptosis by the propolis derivative, GS-002, is partially mediated through ER stress and ATF-3-dependent pathways, and GS-002 has the potential for development as an antitumor drug.

  5. Deuteron-induced activation data in EAF for IFMIF calculations

    International Nuclear Information System (INIS)

    Forrest, R.; Cook, I.

    2006-01-01

    The main type of activation calculations needed for fusion technology deals with the interaction of neutrons with materials. The road map for development of fusion as an electricity producing technology is based on ITER and IFMIF followed by DEMO. IFMIF is a materials testing facility that will enable materials planned to be used in DEMO to be irradiated to very high fluences, so providing the database of material properties required for the licensing of DEMO. IFMIF will use intense beams of high energy deuterons striking a flowing lithium target to produce the neutron field. Although the neutron spectrum is a good match to those produced in a D-T fusion device, there is a significant high energy tail extending up to 55 MeV. These high energy neutrons were the motivation for increasing the upper energy limit in the neutron-induced part of EAF-2005 so that activation calculations could be made in IFMIF. The deuterons themselves will also make a contribution to activation especially in the target where they strike the lithium but also due to beam losses in the accelerator. It was realised that because of corrosion in the lithium loop there is the potential for a wide range of elements to be present in the target region and it is therefore necessary to have a complete library of deuteron-induced cross section data, just as in the neutron case. A preliminary library based on model calculations with TALYS using global parameters was used to construct a deuteron-induced library and this was released as part of the maintenance release of EAF-2005.1 at the beginning of this year. This data library has been used with an updated version of the inventory code FISPACT to calculate the activation in the lithium target due to reactions of the deuterons with the corrosion products. These calculations show that deuterons are much more important than neutrons (about a factor of 70) in activating the elements other than lithium. This work shows the importance of the effect and means

  6. A central role for neuronal adenosine 5'-monophosphate-activated protein kinase in cancer-induced anorexia.

    Science.gov (United States)

    Ropelle, Eduardo R; Pauli, José R; Zecchin, Karina G; Ueno, Mirian; de Souza, Cláudio T; Morari, Joseane; Faria, Marcel C; Velloso, Lício A; Saad, Mario J A; Carvalheira, José B C

    2007-11-01

    The pathogenesis of cancer anorexia is multifactorial and associated with disturbances of the central physiological mechanisms controlling food intake. However, the neurochemical mechanisms responsible for cancer-induced anorexia are unclear. Here we show that chronic infusion of 5-amino-4imidazolecarboxamide-riboside into the third cerebral ventricle and a chronic peripheral injection of 2 deoxy-d-glucose promotes hypothalamic AMP-activated protein kinase (AMPK) activation, increases food intake, and prolongs the survival of anorexic tumor-bearing (TB) rats. In parallel, the pharmacological activation of hypothalamic AMPK in TB animals markedly reduced the hypothalamic production of inducible nitric oxide synthase, IL-1beta, and TNF-alpha and modulated the expression of proopiomelanocortin, a hypothalamic neuropeptide that is involved in the control of energy homeostasis. Furthermore, the daily oral and intracerebroventricular treatment with biguanide antidiabetic drug metformin also induced AMPK phosphorylation in the central nervous system and increased food intake and life span in anorexic TB rats. Collectively, the findings of this study suggest that hypothalamic AMPK activation reverses cancer anorexia by inhibiting the production of proinflammatory molecules and controlling the neuropeptide expression in the hypothalamus, reflecting in a prolonged life span in TB rats. Thus, our data indicate that hypothalamic AMPK activation presents an attractive opportunity for the treatment of cancer-induced anorexia.

  7. Hydrogen Sulfide Prevents Advanced Glycation End-Products Induced Activation of the Epithelial Sodium Channel

    Directory of Open Access Journals (Sweden)

    Qiushi Wang

    2015-01-01

    Full Text Available Advanced glycation end-products (AGEs are complex and heterogeneous compounds implicated in diabetes. Sodium reabsorption through the epithelial sodium channel (ENaC at the distal nephron plays an important role in diabetic hypertension. Here, we report that H2S antagonizes AGEs-induced ENaC activation in A6 cells. ENaC open probability (PO in A6 cells was significantly increased by exogenous AGEs and that this AGEs-induced ENaC activity was abolished by NaHS (a donor of H2S and TEMPOL. Incubating A6 cells with the catalase inhibitor 3-aminotriazole (3-AT mimicked the effects of AGEs on ENaC activity, but did not induce any additive effect. We found that the expression levels of catalase were significantly reduced by AGEs and both AGEs and 3-AT facilitated ROS uptake in A6 cells, which were significantly inhibited by NaHS. The specific PTEN and PI3K inhibitors, BPV(pic  and LY294002, influence ENaC activity in AGEs-pretreated A6 cells. Moreover, after removal of AGEs from AGEs-pretreated A6 cells for 72 hours, ENaC PO remained at a high level, suggesting that an AGEs-related “metabolic memory” may be involved in sodium homeostasis. Our data, for the first time, show that H2S prevents AGEs-induced ENaC activation by targeting the ROS/PI3K/PTEN pathway.

  8. Peroxisome proliferator-activated receptor delta (PPARdelta) activation protects H9c2 cardiomyoblasts from oxidative stress-induced apoptosis.

    Science.gov (United States)

    Pesant, Matthieu; Sueur, Stéphanie; Dutartre, Patrick; Tallandier, Mireille; Grimaldi, Paul A; Rochette, Luc; Connat, Jean-Louis

    2006-02-01

    Activation of peroxisome proliferator-activated receptor alpha (PPARalpha) and PPARgamma plays beneficial roles in cardiovascular disorders such as atherosclerosis and heart reperfusion. Although PPARalpha and gamma have been documented to reduce oxidative stress in the vasculature and the heart, the role of PPARdelta remains poorly studied. We focused on PPARdelta function in the regulation of oxidative stress-induced apoptosis in the rat cardiomyoblast cell line H9c2. Using semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), we showed that PPARdelta is the predominantly expressed isotype whereas PPARalpha was weakly detected. By performing cell viability assays, we also showed that the selective PPARdelta agonist GW501516 protected cells from H(2)O(2)-induced cell death. The protective effect of GW501516 was due to an inhibition of H(2)O(2)-triggered apoptosis as shown by annexin-V labeling, DNA fragmentation analysis, and caspase-3 activity measurement. We demonstrated by transient transfection of a dominant negative mutant of PPARdelta that the protection induced by GW501516 was totally dependent on PPARdelta. Semi-quantitative RT-PCR and Western blotting analysis demonstrated that GW501516 treatment upregulated catalase. Moreover, forced overexpression of catalase inhibited H(2)O(2)-triggered apoptosis, as evidenced by annexin-V labeling. Taken together, our results account for an important role of PPARdelta in inhibiting the onset of oxidative stress-induced apoptosis in H9c2 cells. PPARdelta appears to be a new therapeutic target for the regulation of heart reperfusion-associated oxidative stress and stimulation of enzymatic antioxidative defences.

  9. The influence of experimentally induced pain on shoulder muscle activity

    DEFF Research Database (Denmark)

    Diederichsen, L.P.; Winther, A.; Dyhre-Poulsen, P.

    2009-01-01

    healthy men (range 22-27 years), with no history of shoulder or cervical problems, were included in the study. Pain was induced by 5% hypertonic saline injections into the supraspinatus muscle or subacromially. Seated in a shoulder machine, subjects performed standardized concentric abduction (0A degrees......Muscle function is altered in painful shoulder conditions. However, the influence of shoulder pain on muscle coordination of the shoulder has not been fully clarified. The aim of the present study was to examine the effect of experimentally induced shoulder pain on shoulder muscle function. Eleven...... muscles. EMG was recorded before pain, during pain and after pain had subsided and pain intensity was continuously scored on a visual analog scale (VAS). During abduction, experimentally induced pain in the supraspinatus muscle caused a significant decrease in activity of the anterior deltoid, upper...

  10. Regulation of CCK-induced ERK1/2 activation by PKC epsilon in rat pancreatic acinar cells

    Directory of Open Access Journals (Sweden)

    Chenwei Li

    2017-11-01

    Full Text Available The extracellular signal-regulated kinase ERK1/2 is activated in pancreatic acinar cells by cholecystokinin (CCK and other secretagogues with this activation mediated primarily by protein kinase C (PKC. To identify the responsible PKC isoform, we utilized chemical inhibitors, cell permeant inhibitory peptides and overexpression of individual PKC dominant negative variants by means of adenoviral vectors. While the broad-spectrum PKC inhibitor GF109203X strongly inhibited ERK1/2 activation induced by 100 pM CCK, Go6976 which inhibits the classical PKC isoforms (alpha, beta and gamma, as well as Rottlerin, a specific PKC delta inhibitor, had no inhibitory effect. To test the role of PKC epsilon, we used specific cell permeant peptide inhibitors which block PKC interaction with their intracellular receptors or RACKs. Only PP93 (PKC epsilon peptide inhibitor inhibited CCK-induced ERK1/2 activation, while PP95, PP101 and PP98, which are PKC alpha, delta and zeta peptide inhibitors respectively, had no effect. We also utilized adenovirus to express dominant negative PKC isoforms in pancreatic acini. Only PKC epsilon dominant negative inhibited CCK-induced ERK1/2 activation. Dominant negative PKC epsilon expression similarly blocked the effect of carbachol and bombesin to activate ERK1/2. Immunoprecipitation results demonstrated that CCK can induce an interaction of c-Raf-1 and PKC epsilon, but not that of other isoforms of Raf or PKC. We conclude that PKC epsilon is the isoform of PKC primarily involved with CCK-induced ERK1/2 activation in pancreatic acinar cells.

  11. Porcine parvovirus infection induces apoptosis in PK-15 cells through activation of p53 and mitochondria-mediated pathway

    International Nuclear Information System (INIS)

    Zhang, Hongling; Huang, Yong; Du, Qian; Luo, Xiaomao; Zhang, Liang; Zhao, Xiaomin; Tong, Dewen

    2015-01-01

    Highlights: • PPV reduces PK-15 cells viability by inducing apoptosis. • PPV infection induces apoptosis through mitochondria-mediated pathway. • PPV infection activates p53 to regulate the mitochondria apoptotic signaling. - Abstract: Porcine parvovirus (PPV) infection has been reported to induce the cytopathic effects (CPE) in some special host cells and contribute the occurrence of porcine parvovirus disease, but the molecular mechanisms underlying PPV-induced CPE are not clear. In this study, we investigated the morphological and molecular changes of porcine kidney cell line (PK-15 cells) infected with PPV. The results showed that PPV infection inhibited the viability of PK-15 cells in a time and concentration dependent manner. PPV infection induced typical apoptotic features including chromatin condensation, apoptotic body formation, nuclear fragmentation, and Annexin V-binding activity. Further studies showed that Bax was increased and translocated to mitochondria, whereas Bcl-2 was decreased in PPV-infected cells, which caused mitochondrial outer-membrane permeabilization, resulting in the release of mitochondrial cytochrome c, followed by caspase-9 and caspase-3 activation. However, the expression of Fas and Fas ligand (FasL) did not appear significant changes in the process of PPV-induced apoptosis. Moreover, PPV infection activated p53 signaling, which was involved in the activation of apoptotic signaling induced by PPV infection via regulation of Bax and Bcl-2. Taken together, our results demonstrated that PPV infection induced apoptosis in PK-15 cells through activation of p53 and mitochondria-mediated apoptosis pathway. This study may contribute to shed light on the molecular pathogenesis of PPV infection

  12. Porcine parvovirus infection induces apoptosis in PK-15 cells through activation of p53 and mitochondria-mediated pathway

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hongling; Huang, Yong; Du, Qian; Luo, Xiaomao; Zhang, Liang; Zhao, Xiaomin; Tong, Dewen, E-mail: dwtong@nwsuaf.edu.cn

    2015-01-09

    Highlights: • PPV reduces PK-15 cells viability by inducing apoptosis. • PPV infection induces apoptosis through mitochondria-mediated pathway. • PPV infection activates p53 to regulate the mitochondria apoptotic signaling. - Abstract: Porcine parvovirus (PPV) infection has been reported to induce the cytopathic effects (CPE) in some special host cells and contribute the occurrence of porcine parvovirus disease, but the molecular mechanisms underlying PPV-induced CPE are not clear. In this study, we investigated the morphological and molecular changes of porcine kidney cell line (PK-15 cells) infected with PPV. The results showed that PPV infection inhibited the viability of PK-15 cells in a time and concentration dependent manner. PPV infection induced typical apoptotic features including chromatin condensation, apoptotic body formation, nuclear fragmentation, and Annexin V-binding activity. Further studies showed that Bax was increased and translocated to mitochondria, whereas Bcl-2 was decreased in PPV-infected cells, which caused mitochondrial outer-membrane permeabilization, resulting in the release of mitochondrial cytochrome c, followed by caspase-9 and caspase-3 activation. However, the expression of Fas and Fas ligand (FasL) did not appear significant changes in the process of PPV-induced apoptosis. Moreover, PPV infection activated p53 signaling, which was involved in the activation of apoptotic signaling induced by PPV infection via regulation of Bax and Bcl-2. Taken together, our results demonstrated that PPV infection induced apoptosis in PK-15 cells through activation of p53 and mitochondria-mediated apoptosis pathway. This study may contribute to shed light on the molecular pathogenesis of PPV infection.

  13. Ouabain exacerbates activation-induced cell death in human peripheral blood lymphocytes

    Directory of Open Access Journals (Sweden)

    Mabel B. Esteves

    2005-06-01

    Full Text Available Lymphocytes activated by mitogenic lectins display changes in transmembrane potential, an elevation in the cytoplasmic Ca2+ concentrations, proliferation and/or activation induced cell death. Low concentrations of ouabain (an inhibitor of Na+,K+-ATPase suppress mitogen-induced proliferation and increases cell death. To understand the mechanisms involved, a number of parameters were analyzed using fluorescent probes and flow cytometry. The addition of 100nM ouabain to cultures of peripheral blood lymphocytes activated with 5µg/ml phytohemagglutinin (PHA did not modify the increased expression of the Fas receptor or its ligand FasL induced by the mitogen. However, treatment with ouabain potentiated apoptosis induced by an anti-Fas agonist antibody. A synergy between ouabain and PHA was also observed with regard to plasma membrane depolarization. PHA per se did not induce dissipation of mitochondrial membrane potential but when cells were also exposed to ouabain a marked depolarization could be observed, and this was a late event. It is possible that the inhibitory effect of ouabain on activated peripheral blood lymphocytes involves the potentiation of some of the steps of the apoptotic process and reflects an exacerbation of the mechanism of activation-induced cell death.Quando linfócitos são ativados por lectinas mitogênicas apresentam mudanças do potencial de membrana, elevação das concentrações citoplasmáticas de cálcio, proliferação e/ou morte celular induzida por ativação (AICD. Concentrações baixas de ouabaína (um inibidor da Na,K-ATPase suprimem a proliferação induzida por mitógenos e aumentam a morte celular. Para entender os mecanismos envolvidos, uma série de parâmetros foram avaliados usando sondas fluorescentes e citometria de fluxo. A adição de 100nM de ouabaína para culturas de linfócitos de sangue periférico ativadas por fitohemaglutinina (PHA não modificou o aumento de expressão do receptor Fas ou de

  14. Nuclear DNA damage-triggered NLRP3 inflammasome activation promotes UVB-induced inflammatory responses in human keratinocytes

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, Tatsuya, E-mail: tatsuya.hasegawa@to.shiseido.co.jp; Nakashima, Masaya; Suzuki, Yoshiharu

    2016-08-26

    Ultraviolet (UV) radiation in sunlight can result in DNA damage and an inflammatory reaction of the skin commonly known as sunburn, which in turn can lead to cutaneous tissue disorders. However, little has been known about how UV-induced DNA damage mediates the release of inflammatory mediators from keratinocytes. Here, we show that UVB radiation intensity-dependently increases NLRP3 gene expression and IL-1β production in human keratinocytes. Knockdown of NLRP3 with siRNA suppresses UVB-induced production of not only IL-1β, but also other inflammatory mediators, including IL-1α, IL-6, TNF-α, and PGE{sub 2}. In addition, inhibition of DNA damage repair by knockdown of XPA, which is a major component of the nucleotide excision repair system, causes accumulation of cyclobutane pyrimidine dimer (CPD) and activation of NLRP3 inflammasome. In vivo immunofluorescence analysis confirmed that NLRP3 expression is also elevated in UV-irradiated human epidermis. Overall, our findings indicate that UVB-induced DNA damage initiates NLRP3 inflammasome activation, leading to release of various inflammatory mediators from human keratinocytes. - Highlights: • UVB radiation induces NLRP3 inflammasome activation in human keratinocytes. • NLRP3 knockdown suppresses production of UVB-induced inflammatory mediators. • UVB-induced DNA damage triggers NLRP3 inflammasome activation. • NLRP3 expression in human epidermis is elevated in response to UV radiation.

  15. Nuclear DNA damage-triggered NLRP3 inflammasome activation promotes UVB-induced inflammatory responses in human keratinocytes

    International Nuclear Information System (INIS)

    Hasegawa, Tatsuya; Nakashima, Masaya; Suzuki, Yoshiharu

    2016-01-01

    Ultraviolet (UV) radiation in sunlight can result in DNA damage and an inflammatory reaction of the skin commonly known as sunburn, which in turn can lead to cutaneous tissue disorders. However, little has been known about how UV-induced DNA damage mediates the release of inflammatory mediators from keratinocytes. Here, we show that UVB radiation intensity-dependently increases NLRP3 gene expression and IL-1β production in human keratinocytes. Knockdown of NLRP3 with siRNA suppresses UVB-induced production of not only IL-1β, but also other inflammatory mediators, including IL-1α, IL-6, TNF-α, and PGE_2. In addition, inhibition of DNA damage repair by knockdown of XPA, which is a major component of the nucleotide excision repair system, causes accumulation of cyclobutane pyrimidine dimer (CPD) and activation of NLRP3 inflammasome. In vivo immunofluorescence analysis confirmed that NLRP3 expression is also elevated in UV-irradiated human epidermis. Overall, our findings indicate that UVB-induced DNA damage initiates NLRP3 inflammasome activation, leading to release of various inflammatory mediators from human keratinocytes. - Highlights: • UVB radiation induces NLRP3 inflammasome activation in human keratinocytes. • NLRP3 knockdown suppresses production of UVB-induced inflammatory mediators. • UVB-induced DNA damage triggers NLRP3 inflammasome activation. • NLRP3 expression in human epidermis is elevated in response to UV radiation.

  16. Pyrimidine homoribonucleosides: synthesis, solution conformation, and some biological properties.

    Science.gov (United States)

    Lassota, P; Kuśmierek, J T; Stolarski, R; Shugar, D

    1987-05-01

    Conversion of uridine and cytidine to their 5'-O-tosyl derivatives, followed by cyanation with tetraethylammonium cyanide, reduction and deamination, led to isolation of the hitherto unknown homouridine (1-(5'-deoxy-beta-D-allofuranosyl)uracil) and homocytidine (1-(5'-deoxy-beta-D-allofuranosyl)cytosine), analogues of uridine and cytidine in which the exocyclic 5'-CH2OH chain is extended by one carbon to CH2CH2OH. Homocytidine was also phosphorylated to its 6'-phosphate and 6'-pyrophosphate analogues. In addition, it was converted, via its 2,2'-anhydro derivative, to arahomocytidine, an analogue of the chemotherapeutically active araC. The structures of all the foregoing were established by various criteria, including 1H and 13C NMR spectroscopy, both of which were also applied to analyses of the solution conformations of the various compounds, particularly as regards the conformations of the exocyclic chains. The behaviour of the homo analogues was examined in several enzymatic systems. Homocytidine was a feeble substrate, without inhibitory properties, of E. coli cytidine deaminase. Homocytidine was an excellent substrate for wheat shoot nucleoside phosphotransferase; while homouridine was a good substrate for E. coli uridine phosphorylase. Although homoCMP was neither a substrate, nor an inhibitor, of snake venom 5'-nucleotidase, homoCDP was a potent inhibitor of this enzyme (Ki approximately 6 microM). HomoCDP was not a substrate for M. luteus polynucleotide phosphorylase. None of the compounds exhibited significant activity vs herpes simplex virus type 1, or cytotoxic activity in several mammalian cell lines.

  17. Active Control Does Not Eliminate Motion-Induced Illusory Displacement

    Directory of Open Access Journals (Sweden)

    Ian M. Thornton

    2011-05-01

    Full Text Available When the sine-wave grating of a Gabor patch drifts to the left or right, the perceived position of the entire object is shifted in the direction of local motion. In the current work we explored whether active control of the physical position of the patch overcomes such motion induced illusory displacement. In Experiment 1 we created a simple computer game and asked participants to continuously guide a Gabor patch along a randomly curving path using a joystick. When the grating inside the Gabor patch was stationary, participants could perform this task without error. When the grating drifted to either left or right, we observed systematic errors consistent with previous reports of motion-induced illusory displacement. In Experiment 2 we created an iPad application where the built-in accelerometer tilt control was used to steer the patch through as series of “gates”. Again, we observed systematic guidance errors that depended on the direction and speed of local motion. In conclusion, we found no evidence that participants could adapt or compensate for illusory displacement given active control of the target.

  18. Swing Boat: Inducing and Recording Locomotor Activity in a Drosophila melanogaster Model of Alzheimer’s Disease

    Directory of Open Access Journals (Sweden)

    Johannes Berlandi

    2017-08-01

    Full Text Available Recent studies indicate that physical activity can slow down progression of neurodegeneration in humans. To date, automated ways to induce activity have been predominantly described in rodent models. To study the impact of activity on behavior and survival in adult Drosophila melanogaster, we aimed to develop a rotating tube device “swing boat” which is capable of monitoring activity and sleep patterns as well as survival rates of flies. For the purpose of a first application, we tested our device on a transgenic fly model of Alzheimer’s disease (AD. Activity of flies was recorded in a climate chamber using the Drosophila Activity Monitoring (DAM System connected to data acquisition software. Locomotor activity was induced by a rotating tube device “swing boat” by repetitively tilting the tubes for 30 min per day. A non-exercising group of flies was used as control and activity and sleep patterns were obtained. The GAL4-/UAS system was used to drive pan-neuronal expression of human Aβ42 in flies. Immunohistochemical stainings for Aβ42 were performed on paraffin sections of adult fly brains. Daily rotation of the fly tubes evoked a pronounced peak of activity during the 30 min exercise period. Pan-neuronal expression of human Aβ42 in flies caused abnormalities in locomotor activity, reduction of life span and elevated sleep fragmentation in comparison to wild type flies. Furthermore, the formation of amyloid accumulations was observed in the adult fly brain. Gently induced activity over 12 days did not evoke prominent effects in wild type flies but resulted in prolongation of median survival time by 7 days (32.6% in Aβ42-expressing flies. Additionally, restoration of abnormally decreased night time sleep (10% and reduced sleep fragmentation (28% were observed compared to non-exercising Aβ42-expressing flies. On a structural level no prominent effects regarding prevalence of amyloid aggregations and Aβ42 RNA expression were

  19. Exposure to nickel oxide nanoparticles induces pulmonary inflammation through NLRP3 inflammasome activation in rats.

    Science.gov (United States)

    Cao, Zhengwang; Fang, Yiliang; Lu, Yonghui; Qian, Fenghua; Ma, Qinglong; He, Mingdi; Pi, Huifeng; Yu, Zhengping; Zhou, Zhou

    2016-01-01

    With recent advances in the manufacture and application of nickel oxide nanoparticles (NiONPs), concerns about their adverse effects on the respiratory system are increasing. However, the underlying cellular and molecular mechanisms of NiONP-induced pulmonary toxicity remain unclear. In this study, we focused on the impacts of NiONPs on pulmonary inflammation and investigated whether the NLRP3 inflammasome is involved in NiONP-induced pulmonary inflammation and injury. NiONP suspensions were administered by single intratracheal instillation to rats, and inflammatory responses were evaluated at 3 days, 7 days, or 28 days after treatment. NiONP exposure resulted in sustained pulmonary inflammation accompanied by inflammatory cell infiltration, alveolar proteinosis, and cytokine secretion. Expression of Nlrp3 was markedly upregulated by the NiONPs, which was accompanied by overexpression of the active form of caspase-1 (p20) and interleukin (IL)-1β secretion in vivo. NiONP-induced IL-1β secretion was partially prevented by co-treatment with a caspase-1 inhibitor in macrophages. Moreover, siRNA-mediated Nlrp3 knockdown completely attenuated NiONP-induced cytokine release and caspase-1 activity in macrophages in vitro. In addition, NiONP-induced NLRP3 inflammasome activation requires particle uptake and reactive oxygen species production. Collectively, our findings suggest that the NLRP3 inflammasome participates in NiONP-induced pulmonary inflammation and offer new strategies to combat the pulmonary toxicity induced by NiONPs.

  20. Music-induced emotions can be predicted from a combination of brain activity and acoustic features.

    Science.gov (United States)

    Daly, Ian; Williams, Duncan; Hallowell, James; Hwang, Faustina; Kirke, Alexis; Malik, Asad; Weaver, James; Miranda, Eduardo; Nasuto, Slawomir J

    2015-12-01

    It is widely acknowledged that music can communicate and induce a wide range of emotions in the listener. However, music is a highly-complex audio signal composed of a wide range of complex time- and frequency-varying components. Additionally, music-induced emotions are known to differ greatly between listeners. Therefore, it is not immediately clear what emotions will be induced in a given individual by a piece of music. We attempt to predict the music-induced emotional response in a listener by measuring the activity in the listeners electroencephalogram (EEG). We combine these measures with acoustic descriptors of the music, an approach that allows us to consider music as a complex set of time-varying acoustic features, independently of any specific music theory. Regression models are found which allow us to predict the music-induced emotions of our participants with a correlation between the actual and predicted responses of up to r=0.234,pmusic induced emotions can be predicted by their neural activity and the properties of the music. Given the large amount of noise, non-stationarity, and non-linearity in both EEG and music, this is an encouraging result. Additionally, the combination of measures of brain activity and acoustic features describing the music played to our participants allows us to predict music-induced emotions with significantly higher accuracies than either feature type alone (p<0.01). Copyright © 2015 Elsevier Inc. All rights reserved.

  1. The psychedelic state induced by ayahuasca modulates the activity and connectivity of the default mode network.

    Science.gov (United States)

    Palhano-Fontes, Fernanda; Andrade, Katia C; Tofoli, Luis F; Santos, Antonio C; Crippa, Jose Alexandre S; Hallak, Jaime E C; Ribeiro, Sidarta; de Araujo, Draulio B

    2015-01-01

    The experiences induced by psychedelics share a wide variety of subjective features, related to the complex changes in perception and cognition induced by this class of drugs. A remarkable increase in introspection is at the core of these altered states of consciousness. Self-oriented mental activity has been consistently linked to the Default Mode Network (DMN), a set of brain regions more active during rest than during the execution of a goal-directed task. Here we used fMRI technique to inspect the DMN during the psychedelic state induced by Ayahuasca in ten experienced subjects. Ayahuasca is a potion traditionally used by Amazonian Amerindians composed by a mixture of compounds that increase monoaminergic transmission. In particular, we examined whether Ayahuasca changes the activity and connectivity of the DMN and the connection between the DMN and the task-positive network (TPN). Ayahuasca caused a significant decrease in activity through most parts of the DMN, including its most consistent hubs: the Posterior Cingulate Cortex (PCC)/Precuneus and the medial Prefrontal Cortex (mPFC). Functional connectivity within the PCC/Precuneus decreased after Ayahuasca intake. No significant change was observed in the DMN-TPN orthogonality. Altogether, our results support the notion that the altered state of consciousness induced by Ayahuasca, like those induced by psilocybin (another serotonergic psychedelic), meditation and sleep, is linked to the modulation of the activity and the connectivity of the DMN.

  2. Human immunodeficiency virus-induced pathology favored by cellular transmission and activation

    International Nuclear Information System (INIS)

    Lewis, D.E.; Yoffe, B.; Bosworth, C.G.; Hollinger, F.B.; Rich, R.R.

    1988-01-01

    Epidemiological data suggest that transmission of human immunodeficiency virus (HIV) occurs primarily by transference of virally infected cells. However, the efficiency of lytic productive infection induced by HIV after transmission of cell-associated virus vs. free virus is difficult to assess. The present studies compare the extent of depletion of CD4+ (helper/inducer) T cells after mixing uninfected cells with either free HIV or irradiated HIV-infected allogeneic or autologous cells in vitro. Rapid CD4+ cellular depletion occurred only in cultures containing allogeneic infected cells or after addition of a nonspecific T cell activation signal to cultures with autologous infected cells. These in vitro observations strongly support the epidemiological implication that interactions between infected and uninfected cells are the most efficient means of transmission and HIV-induced cytopathology in vivo. They also provide direct support for the concept that immunological stimulation by foreign cells infected with HIV dramatically increases the likelihood of transmission. These in vitro observations suggest a model for the acquisition of HIV in vivo and the role of cellular activation in dissemination of the virus to uninfected cells in an infected individual

  3. Involvement of mitogen-activated protein kinases and NFκB in LPS-induced CD40 expression on human monocytic cells

    International Nuclear Information System (INIS)

    Wu Weidong; Alexis, Neil E.; Chen Xian; Bromberg, Philip A.; Peden, David B.

    2008-01-01

    CD40 is a costimulatory molecule linking innate and adaptive immune responses to bacterial stimuli, as well as a critical regulator of functions of other costimulatory molecules. The mechanisms regulating lipopolysaccharide (LPS)-induced CD40 expression have not been adequately characterized in human monocytic cells. In this study we used a human monocytic cell line, THP-1, to investigate the possible mechanisms of CD40 expression following LPS exposure. Exposure to LPS resulted in a dose- and time-dependent increase in CD40 expression. Further studies using immunoblotting and pharmacological inhibitors revealed that mitogen-activated protein kinases (MAPKs) and NFκB were activated by LPS exposure and involved in LPS-induced CD40 expression. Activation of MAPKs was not responsible for LPS-induced NFκB activation. TLR4 was expressed on THP-1 cells and pretreatment of cells with a Toll-like receptor 4 (TLR4) neutralizing antibody (HTA125) significantly blunted LPS-induced MAPK and NFκB activation and ensuing CD40 expression. Additional studies with murine macrophages expressing wild type and mutated TLR4 showed that TLR4 was implicated in LPS-induced ERK and NFκB activation, and CD40 expression. Moreover, blockage of MAPK and NFκB activation inhibited LPS-induced TLR4 expression. In summary, LPS-induced CD40 expression in monocytic cells involves MAPKs and NFκB

  4. Kurarinol induces hepatocellular carcinoma cell apoptosis through suppressing cellular signal transducer and activator of transcription 3 signaling

    International Nuclear Information System (INIS)

    Shu, Guangwen; Yang, Jing; Zhao, Wenhao; Xu, Chan; Hong, Zongguo; Mei, Zhinan; Yang, Xinzhou

    2014-01-01

    Kurarinol is a flavonoid isolated from roots of the medical plant Sophora flavescens. However, its cytotoxic activity against hepatocellular carcinoma (HCC) cells and toxic effects on mammalians remain largely unexplored. Here, the pro-apoptotic activities of kurarinol on HCC cells and its toxic impacts on tumor-bearing mice were evaluated. The molecular mechanisms underlying kurarinol-induced HCC cell apoptosis were also investigated. We found that kurarinol dose-dependently provoked HepG2, Huh-7 and H22 HCC cell apoptosis. In addition, kurarinol gave rise to a considerable decrease in the transcriptional activity of signal transducer and activator of transcription 3 (STAT3) in HCC cells. Suppression of STAT3 signaling is involved in kurarinol-induced HCC cell apoptosis. In vivo studies showed that kurarinol injection substantially induced transplanted H22 cell apoptosis with low toxic impacts on tumor-bearing mice. Similarly, the transcriptional activity of STAT3 in transplanted tumor tissues was significantly suppressed after kurarinol treatment. Collectively, our current research demonstrated that kurarinol has the capacity of inducing HCC cell apoptosis both in vitro and in vivo with undetectable toxic impacts on the host. Suppressing STAT3 signaling is implicated in kurarinol-mediated HCC cell apoptosis. - Highlights: • Kurarinol induces hepatocellular carcinoma (HCC) cell apoptosis. • Kurarinol induces HCC cell apoptosis via inhibiting STAT3. • Kurarinol exhibits low toxic effects on tumor-bearing animals

  5. Imaging of activated caspase-3 in living cell by fluorescence resonance energy transfer during photosensitization-induced apoptosis

    Science.gov (United States)

    Wu, Yunxia; Xing, Da; Chen, Qun; Tang, Yonghong

    2005-01-01

    Photodynamic therapy (PDT) is a novel and promising cancer treatment that employs a combination of a photosensitizing chemical and visible light, induces apoptosis in cell, and activation of caspase-3 is considered to be the final step in many apoptosis pathways. The changes of caspase-3 activation in cell during TNFα- and photodynamic therapy-induced apoptosis was measured by fluorescence resonance energy transfer (FRET) analysis. FRET probe consisting of fusions of an enhanced cyan fluorescent protein (ECFP), Venus and a linker peptide containing the caspase-3 cleavage sequence DEVD was utilized. Therefore, activated caspase-3 cleaved the linker peptide of FRET probe and disrupted the FRET signal. Human lung adenocarcinoma cell line (ASTC-a-1) were stably transfected with the plasmid (ECFP-DEVD-Venus) and then were treated by TNF-α and PDT, respectively. Experimental results indicated that caspase-3 activation resulted in cleavage of linker peptide and subsequent disruption of the FRET signal during TNFα- and photodynamic therapy-induced apoptosis, and that the activation of caspase-3 induced by photodynamic therapy was faster than that induce by TNF-α. The study supports that using FRET technique and different recombinant substrates as FRET probes could be used to detect the process of PDT-induced apoptosis and provide a new means to investigate apoptotic mechanism of PDT.

  6. Piperidine alkaloids from Piperretrofractum Vahl. protect against high-fat diet-induced obesity by regulating lipid metabolism and activating AMP-activated protein kinase

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyung Jin [Department of Biomaterials Science and Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of); Lee, Myoung-Su; Jo, Keunae [Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of); Hwang, Jae-Kwan, E-mail: jkhwang@yonsei.ac.kr [Department of Biomaterials Science and Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of); Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of); Translational Research Center for Protein Functional Control, Yonsei University, Seoul 120-749 (Korea, Republic of)

    2011-07-22

    Highlights: {yields} Piperidine alkaloids from Piperretrofractum Vahl. (PRPAs), including piperine, pipernonaline, and dehydropipernonaline, are isolated as the anti-obesity constituents. {yields} PRPA administration significantly reduces body weight gain without altering food intake and fat pad mass. {yields} PRPA reduces high-fat diet-induced triglyceride accumulation in liver. {yields} PRPAs attenuate HFD-induced obesity by activating AMPK and PPAR{delta}, and regulate lipid metabolism, suggesting their potential anti-obesity effects. -- Abstract: The fruits of Piperretrofractum Vahl. have been used for their anti-flatulent, expectorant, antitussive, antifungal, and appetizing properties in traditional medicine, and they are reported to possess gastroprotective and cholesterol-lowering properties. However, their anti-obesity activity remains unexplored. The present study was conducted to isolate the anti-obesity constituents from P. retrofractum Vahl. and evaluate their effects in high-fat diet (HFD)-induced obese mice. Piperidine alkaloids from P. retrofractum Vahl. (PRPAs), including piperine, pipernonaline, and dehydropipernonaline, were isolated as the anti-obesity constituents through a peroxisome proliferator-activated receptor {delta} (PPAR{delta}) transactivation assay. The molecular mechanism was investigated in 3T3-L1 adipocytes and L6 myocytes. PRPA treatment activated AMP-activated protein kinase (AMPK) signaling and PPAR{delta} protein and also regulated the expression of lipid metabolism-related proteins. In the animal model, oral PRPA administration (50, 100, or 300 mg/kg/day for 8 weeks) significantly reduced HFD-induced body weight gain without altering the amount of food intake. Fat pad mass was reduced in the PRPA treatment groups, as evidenced by reduced adipocyte size. In addition, elevated serum levels of total cholesterol, low-density lipoprotein cholesterol, total lipid, leptin, and lipase were suppressed by PRPA treatment. PRPA also

  7. Piperidine alkaloids from Piperretrofractum Vahl. protect against high-fat diet-induced obesity by regulating lipid metabolism and activating AMP-activated protein kinase

    International Nuclear Information System (INIS)

    Kim, Kyung Jin; Lee, Myoung-Su; Jo, Keunae; Hwang, Jae-Kwan

    2011-01-01

    Highlights: → Piperidine alkaloids from Piperretrofractum Vahl. (PRPAs), including piperine, pipernonaline, and dehydropipernonaline, are isolated as the anti-obesity constituents. → PRPA administration significantly reduces body weight gain without altering food intake and fat pad mass. → PRPA reduces high-fat diet-induced triglyceride accumulation in liver. → PRPAs attenuate HFD-induced obesity by activating AMPK and PPARδ, and regulate lipid metabolism, suggesting their potential anti-obesity effects. -- Abstract: The fruits of Piperretrofractum Vahl. have been used for their anti-flatulent, expectorant, antitussive, antifungal, and appetizing properties in traditional medicine, and they are reported to possess gastroprotective and cholesterol-lowering properties. However, their anti-obesity activity remains unexplored. The present study was conducted to isolate the anti-obesity constituents from P. retrofractum Vahl. and evaluate their effects in high-fat diet (HFD)-induced obese mice. Piperidine alkaloids from P. retrofractum Vahl. (PRPAs), including piperine, pipernonaline, and dehydropipernonaline, were isolated as the anti-obesity constituents through a peroxisome proliferator-activated receptor δ (PPARδ) transactivation assay. The molecular mechanism was investigated in 3T3-L1 adipocytes and L6 myocytes. PRPA treatment activated AMP-activated protein kinase (AMPK) signaling and PPARδ protein and also regulated the expression of lipid metabolism-related proteins. In the animal model, oral PRPA administration (50, 100, or 300 mg/kg/day for 8 weeks) significantly reduced HFD-induced body weight gain without altering the amount of food intake. Fat pad mass was reduced in the PRPA treatment groups, as evidenced by reduced adipocyte size. In addition, elevated serum levels of total cholesterol, low-density lipoprotein cholesterol, total lipid, leptin, and lipase were suppressed by PRPA treatment. PRPA also protected against the development of

  8. Evidence for a Proangiogenic Activity of TNF-Related Apoptosis-Inducing Ligand

    Directory of Open Access Journals (Sweden)

    Paola Secchiero

    2004-07-01

    Full Text Available Starting from the observation that tumor necrosis factor-related apoptosis-inducing ligand (TRAIL/ Apo-2L protein is expressed in both malignant and inflammatory cells in some highly vascularized soft tissue sarcomas, the angiogenic potential of TRAIL was investigated in a series of in vitro assays. Recombinant soluble TRAIL induced endothelial cell migration and vessel tube formation to a degree comparable to vascular endothelial growth factor (VEGF, one of the best-characterized angiogenic factors. However, the proangiogenic activity of TRAIL was not mediated by endogenous expression of VEGF. Although TRAIL potentiated VEGF-induced extracellular signal-regulated kinase (ERK phosphorylation and endothelial cell proliferation, the combination of TRAIL + VEGF did not show additive effects with respect to VEGF alone in inducing vessel tube formation. Thus, although TRAIL has gained attention as a potential anticancer therapeutic for its ability to induce apoptosis in a variety of cancer cells, our present data suggest that TRAIL might also play an unexpected role in promoting angiogenesis, which might have therapeutic implications.

  9. Ultrafine particles from diesel engines induce vascular oxidative stress via JNK activation.

    Science.gov (United States)

    Li, Rongsong; Ning, Zhi; Cui, Jeffery; Khalsa, Bhavraj; Ai, Lisong; Takabe, Wakako; Beebe, Tyler; Majumdar, Rohit; Sioutas, Constantinos; Hsiai, Tzung

    2009-03-15

    Exposure to particulate air pollution is linked to increased incidences of cardiovascular diseases. Ambient ultrafine particles (UFP) from diesel vehicle engines have been shown to be proatherogenic in ApoE knockout mice and may constitute a major cardiovascular risk in humans. We posited that circulating nano-sized particles from traffic pollution sources induce vascular oxidative stress via JNK activation in endothelial cells. Diesel UFP were collected from a 1998 Kenworth truck. Intracellular superoxide assay revealed that these UFP dose-dependently induced superoxide (O(2)(-)) production in human aortic endothelial cells (HAEC). Flow cytometry showed that UFP increased MitoSOX red intensity specific for mitochondrial superoxide. Protein carbonyl content was increased by UFP as an indication of vascular oxidative stress. UFP also up-regulated heme oxygenase-1 (HO-1) and tissue factor (TF) mRNA expression, and pretreatment with the antioxidant N-acetylcysteine significantly decreased their expression. Furthermore, UFP transiently activated JNK in HAEC. Treatment with the JNK inhibitor SP600125 and silencing of both JNK1 and JNK2 with siRNA inhibited UFP-stimulated O(2)(-) production and mRNA expression of HO-1 and TF. Our findings suggest that JNK activation plays an important role in UFP-induced oxidative stress and stress response gene expression.

  10. Fenoterol inhibits LPS-induced AMPK activation and inflammatory cytokine production through β-arrestin-2 in THP-1 cell line

    International Nuclear Information System (INIS)

    Wang, Wei; Zhang, Yuan; Xu, Ming; Zhang, You-Yi; He, Bei

    2015-01-01

    The AMP-activated protein kinase (AMPK) pathway is involved in regulating inflammation in several cell lines. We reported that fenoterol, a β 2 -adrenergic receptor (β 2 -AR) agonist, had anti-inflammatory effects in THP-1 cells, a monocytic cell line. Whether the fenoterol anti-inflammatory effect involves the AMPK pathway is unknown. In this study, we explored the mechanism of β 2 -AR stimulation with fenoterol in a lipopolysaccharide (LPS)-induced inflammatory cytokine secretion in THP-1 cells. We studied whether fenoterol and β-arrestin-2 or AMPKα1 subunit knockdown could affect LPS-induced AMPK activation, nuclear factor-kappa B (NF-κB) activation and inflammatory cytokine secretion. LPS-induced AMPK activation and interleukin 1β (IL-1β) release were reduced with fenoterol pretreatment of THP-1 cells. SiRNA knockdown of β-arrestin-2 abolished the fenoterol inhibition of LPS-induced AMPK activation and interleukin 1β (IL-1β) release, thus β-arrestin-2 mediated the anti-inflammatory effects of fenoterol on LPS-treated THP-1 cells. In addition, siRNA knockdown of AMPKα1 significantly attenuated the LPS-induced NF-κB activation and IL-1β release, so AMPKα1 was a key signaling molecule involved in LPS-induced inflammatory cytokine production. These results suggested the β 2 -AR agonist fenoterol inhibited LPS-induced AMPK activation and IL-1β release via β-arrestin-2 in THP-1 cells. The exploration of these mechanisms may help optimize therapeutic agents targeting these pathways in inflammatory diseases. - Highlights: • β 2 -AR agonist fenoterol exerts its protective effect on LPS-treated THP-1 cells. • Fenoterol inhibits LPS-induced AMPK activation and IL-1β production. • β-arrestin2 mediates fenoterol-inhibited AMPK activation and IL-1β release. • AMPKα1 is involved in LPS-induced NF-κB activation and IL-1β production

  11. Fenoterol inhibits LPS-induced AMPK activation and inflammatory cytokine production through β-arrestin-2 in THP-1 cell line

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wei [Department of Respiratory Medicine, Peking University Third Hospital, Beijing (China); Department of Infectious Diseases, Peking University Third Hospital, Beijing (China); Zhang, Yuan [Department of Respiratory Medicine, Peking University Third Hospital, Beijing (China); Xu, Ming; Zhang, You-Yi [Department of Institute of Vascular Medicine and Beijing Key Laboratory of Cardiovascular Receptors Research, Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides, Peking University Third Hospital, Beijing (China); He, Bei, E-mail: puh3_hb@bjmu.edu.cn [Department of Respiratory Medicine, Peking University Third Hospital, Beijing (China)

    2015-06-26

    The AMP-activated protein kinase (AMPK) pathway is involved in regulating inflammation in several cell lines. We reported that fenoterol, a β{sub 2}-adrenergic receptor (β{sub 2}-AR) agonist, had anti-inflammatory effects in THP-1 cells, a monocytic cell line. Whether the fenoterol anti-inflammatory effect involves the AMPK pathway is unknown. In this study, we explored the mechanism of β{sub 2}-AR stimulation with fenoterol in a lipopolysaccharide (LPS)-induced inflammatory cytokine secretion in THP-1 cells. We studied whether fenoterol and β-arrestin-2 or AMPKα1 subunit knockdown could affect LPS-induced AMPK activation, nuclear factor-kappa B (NF-κB) activation and inflammatory cytokine secretion. LPS-induced AMPK activation and interleukin 1β (IL-1β) release were reduced with fenoterol pretreatment of THP-1 cells. SiRNA knockdown of β-arrestin-2 abolished the fenoterol inhibition of LPS-induced AMPK activation and interleukin 1β (IL-1β) release, thus β-arrestin-2 mediated the anti-inflammatory effects of fenoterol on LPS-treated THP-1 cells. In addition, siRNA knockdown of AMPKα1 significantly attenuated the LPS-induced NF-κB activation and IL-1β release, so AMPKα1 was a key signaling molecule involved in LPS-induced inflammatory cytokine production. These results suggested the β{sub 2}-AR agonist fenoterol inhibited LPS-induced AMPK activation and IL-1β release via β-arrestin-2 in THP-1 cells. The exploration of these mechanisms may help optimize therapeutic agents targeting these pathways in inflammatory diseases. - Highlights: • β{sub 2}-AR agonist fenoterol exerts its protective effect on LPS-treated THP-1 cells. • Fenoterol inhibits LPS-induced AMPK activation and IL-1β production. • β-arrestin2 mediates fenoterol-inhibited AMPK activation and IL-1β release. • AMPKα1 is involved in LPS-induced NF-κB activation and IL-1β production.

  12. Inhibition of IL-1 activity induced with allogeneic transfusion of UV-irradiated blood

    International Nuclear Information System (INIS)

    Horvat, B.; Poljak-Blazi, M.; Hadija, M.

    1991-01-01

    Treatment with UV-irradiated donor-specific blood transfusion is known to induce specific unresponsiveness in recipient animals and prolong allograft survival. Mixed lymphocyte response in transfused mice was decreased towards spleen cells of the blood donor strain, but was not altered to third-party cells. Sera from treated mice showed significantly lower interleukin-1 (IL-1) activity, which was increased with higher dilutions of sera, indicating the presence of IL-1 inhibitor. Furthermore, sera decreased rIL-1-induced cell proliferation in dose-dependent manner, while the response to rIL-2 neither depended on the concentration of sera, nor differed between non-treated controls and treated mice. These results indicate that UV-irradiated allogeneic blood transfusion could induce an inhibitor, specifically directed to IL-1 activity, which may be involved in the generation of immunological unresponsiveness in treated animals. (author)

  13. Small molecule inhibitors block Gas6-inducible TAM activation and tumorigenicity.

    Science.gov (United States)

    Kimani, Stanley G; Kumar, Sushil; Bansal, Nitu; Singh, Kamalendra; Kholodovych, Vladyslav; Comollo, Thomas; Peng, Youyi; Kotenko, Sergei V; Sarafianos, Stefan G; Bertino, Joseph R; Welsh, William J; Birge, Raymond B

    2017-03-08

    TAM receptors (Tyro-3, Axl, and Mertk) are a family of three homologous type I receptor tyrosine kinases that are implicated in several human malignancies. Overexpression of TAMs and their major ligand Growth arrest-specific factor 6 (Gas6) is associated with more aggressive staging of cancers, poorer predicted patient survival, acquired drug resistance and metastasis. Here we describe small molecule inhibitors (RU-301 and RU-302) that target the extracellular domain of Axl at the interface of the Ig-1 ectodomain of Axl and the Lg-1 of Gas6. These inhibitors effectively block Gas6-inducible Axl receptor activation with low micromolar IC 50s in cell-based reporter assays, inhibit Gas6-inducible motility in Axl-expressing cell lines, and suppress H1299 lung cancer tumor growth in a mouse xenograft NOD-SCIDγ model. Furthermore, using homology models and biochemical verifications, we show that RU301 and 302 also inhibit Gas6 inducible activation of Mertk and Tyro3 suggesting they can act as pan-TAM inhibitors that block the interface between the TAM Ig1 ectodomain and the Gas6 Lg domain. Together, these observations establish that small molecules that bind to the interface between TAM Ig1 domain and Gas6 Lg1 domain can inhibit TAM activation, and support the further development of small molecule Gas6-TAM interaction inhibitors as a novel class of cancer therapeutics.

  14. Ethylenediaminetetraacetic acid induces antioxidant and anti-inflammatory activities in experimental liver fibrosis.

    Science.gov (United States)

    González-Cuevas, J; Navarro-Partida, J; Marquez-Aguirre, A L; Bueno-Topete, M R; Beas-Zarate, C; Armendáriz-Borunda, J

    2011-01-01

    Experimental liver fibrosis induced by carbon tetrachloride (CCl(4)) is associated with oxidative stress, lipid peroxidation, and inflammation. This work was focused on elucidating the anti-inflammatory and antioxidant effects of ethylenediaminetetraacetic acid (EDTA) in this model of hepatotoxicity. Wistar male rats were treated with CCl(4) and EDTA (60, 120, or 240 mg/kg). Morphometric analyses were carried out in Masson's stained liver sections to determine fibrosis index. Coagulation tests prothrombin time (PT) and partial thromboplastin time (PTT) were also determined. Gene expression for transforming growth factor beta (TGF-beta1), alpha1(I) procollagen gene (alpha1 Col I), tumor necrosis factor alpha (TNF-alpha), interleukin-6 (IL-6), and superoxide dismutase (SOD) was monitored by real-time PCR. Antioxidant effect of EDTA was measured by its effects on lipid peroxidation; biological activity of ceruloplasmin (Cp), SOD, and catalase (Cat) were analyzed by zymography assays. Animals with CCl(4)-hepatic injury that received EDTA showed a decrement in fibrosis (20%) and lipid peroxidation (22%). The mRNA expression for TNF-alpha (55%), TGF-beta1 (50%), IL-6 (52%), and alpha1 Col I (60%) was also decreased. This group of animals showed increased Cp (62%) and SOD (25%) biological activities. Coagulation blood tests, Cat activity, and gene expression for SOD were not modified by EDTA treatment. This study demonstrates that EDTA treatment induces the activity of antioxidant enzymes, decreases lipid peroxidation, hepatic inflammation, and fibrosis in experimental liver fibrosis induced by CCl(4).

  15. Inhibitory effects of ascorbic acid, vitamin E, and vitamin B-complex on the biological activities induced by Bothrops venom.

    Science.gov (United States)

    Oliveira, Carlos Henrique de Moura; Assaid Simão, Anderson; Marcussi, Silvana

    2016-01-01

    Natural compounds have been widely studied with the aim of complementing antiophidic serum therapy. The present study evaluated the inhibitory potential of ascorbic acid and a vitamin complex, composed of ascorbic acid, vitamin E, and all the B-complex vitamins, on the biological activities induced by snake venoms. The effect of vitamins was evaluated on the phospholipase, proteolytic, coagulant, and fibrinogenolytic activities induced by Bothrops moojeni (Viperidae), B. jararacussu, and B. alternatus snake venoms, and the hemagglutinating activity induced by B. jararacussu venom. The vitamin complex (1:5 and 1:10 ratios) totally inhibited the fibrinogenolytic activity and partially the phospholipase activity and proteolytic activity on azocasein induced by the evaluated venoms. Significant inhibition was observed in the coagulation of human plasma induced by venoms from B. alternatus (1:2.5 and 1:5, to vitamin complex and ascorbic acid) and B. moojeni (1:2.5 and 1:5, to vitamin complex and ascorbic acid). Ascorbic acid inhibited 100% of the proteolytic activities of B. moojeni and B. alternatus on azocasein, at 1:10 ratio, the effects of all the venoms on fibrinogen, the hemagglutinating activity of B. jararacussu venom, and also extended the plasma coagulation time induced by all venoms analyzed. The vitamins analyzed showed relevant in vitro inhibitory potential over the activities induced by Bothrops venoms, suggesting their interaction with toxins belonging to the phospholipase A2, protease, and lectin classes. The results can aid further research in clarifying the possible mechanisms of interaction between vitamins and snake enzymes.

  16. Evodiamine attenuates TGF-β1-induced fibroblast activation and endothelial to mesenchymal transition.

    Science.gov (United States)

    Wu, Qing-Qing; Xiao, Yang; Jiang, Xiao-Han; Yuan, Yuan; Yang, Zheng; Chang, Wei; Bian, Zhou-Yan; Tang, Qi-Zhu

    2017-06-01

    The aim of this study is to investigate the effect of evodiamine on fibroblast activation in cardiac fibroblasts and endothelial to mesenchymal transition (EndMT) in human umbilical vein endothelial cells (HUVECs). Neonatal rat cardiac fibroblasts were stimulated with transforming growth factor beta 1 (TGF-β1) to induce fibroblast activation. After co-cultured with evodiamine (5, 10 μM), the proliferation and pro-fibrotic proteins expression of cardiac fibroblasts were evaluated. HUVECs were also stimulated with TGF-β1 to induce EndMT and treated with evodiamine (5, 10 μM) at the same time. The EndMT response in the HUVECs was evaluated as well as the capacity of the transitioned endothelial cells migrating to surrounding tissue. As a result, Evodiamine-blunted TGF-β1 induced activation of cardiac fibroblast into myofibroblast as assessed by the decreased expressions of α-SMA. Furthermore, evodiamine reduced the increased protein expression of fibrosis markers in neonatal and adult rat cardiac fibroblasts induced by TGF-β1. HUVECs stimulated with TGF-β1 exhibited lower expression levels of CD31, CD34, and higher levels of α-SMA, vimentin than the control cells. This phenotype was eliminated in the HUVECs treated with both 5 and 10 μM evodiamine. Evodiamine significantly reduced the increase in migration ability that occurred in response to TGF-β1 in HUVECs. In addition, the activation of Smad2, Smad3, ERK1/2, and Akt, and the nuclear translocation of Smad4 in both cardiac fibroblasts and HUVEC were blocked by evodiamine treatment. Thus, evodiamine could prevent cardiac fibroblasts from activation into myofibroblast and protect HUVEC against EndMT. These effects may be mediated by inhibition of the TGFβ pathway in both cardiac fibroblasts and HUVECs.

  17. Inhibitory effects of glucocorticoid on apoptosis and activation of NF-κB in P388 cells induced by radiation

    International Nuclear Information System (INIS)

    Shi Jianhui; Niu Yuhong; Ge Junbo; Xu Xiaoping; Cheng Wenying; Feng Xiao; Zhang Zongliang

    2002-01-01

    Objective: To explore effects of glucocorticoid on apoptosis and activation of NF-κB in P388 cells induced by radiation. Methods: Apoptosis in P388 cells induced by radiation treatment was detected by TUNEL assay. EMSA was used to detect the activation of NF-κB . Results: The apoptosis and activation of NF-κB in P388 cells could be induced by radiation. Dexamethasone (DXM) which could suppress activation of NF-κB of P388 cells increased significantly the apoptosis induced by radiation. Apoptosis rates in DXM-treated P388 cells after 2, 4, 6 and 8 Gy exposure increased by 60%, 100%, 129% and 67%, respectively. Activation rates of NF-κB in DXM-treated P388 cells after 2, 4, 6 and 8 Gy exposure decreased by 25%, 45%, 52% and 40%, respectively. Conclusion: Radiation induces apoptosis and activation of NF-κB in P388 cells simultaneously. Glucocorticoid enhances apoptosis in leukemic cells, which may be by means of suppressing activation of NF-κB

  18. Curcumin protects neurons against oxygen-glucose deprivation/reoxygenation-induced injury through activation of peroxisome proliferator-activated receptor-γ function.

    Science.gov (United States)

    Liu, Zun-Jing; Liu, Hong-Qiang; Xiao, Cheng; Fan, Hui-Zhen; Huang, Qing; Liu, Yun-Hai; Wang, Yu

    2014-11-01

    The turmeric derivative curcumin protects against cerebral ischemic injury. We previously demonstrated that curcumin activates peroxisome proliferator-activated receptor-γ (PPARγ), a ligand-activated transcription factor involved in both neuroprotective and anti-inflammatory signaling pathways. This study tested whether the neuroprotective effects of curcumin against oxygen-glucose deprivation/reoxygenation (OGD/R)-induced injury of rat cortical neurons are mediated (at least in part) by PPARγ. Curcumin (10 μM) potently enhanced PPARγ expression and transcriptional activity following OGD/R. In addition, curcumin markedly increased neuronal viability, as evidenced by decreased lactate dehydrogenase release and reduced nitric oxide production, caspase-3 activity, and apoptosis. These protective effects were suppressed by coadministration of the PPARγ antagonist 2-chloro-5-nitrobenzanilide (GW9662) and by prior transfection of a small-interfering RNA (siRNA) targeting PPARγ, treatments that had no toxic effects on healthy neurons. Curcumin reduced OGD/R-induced accumulation of reactive oxygen species and inhibited the mitochondrial apoptosis pathway, as indicated by reduced release of cytochrome c and apoptosis-inducing factor and maintenance of both the mitochondrial membrane potential and the Bax/Bcl-2 ratio. Again, GW9662 or PPARγ siRNA transfection mitigated the protective effects of curcumin on mitochondrial function. Curcumin suppressed IκB kinase phosphorylation and IκB degradation, thereby inhibiting nuclear factor-κ B (NF-κB) nuclear translocation, effects also blocked by GW9662 or PPARγ siRNA. Immunoprecipitation experiments revealed that PPARγ interacted with NF-κB p65 and inhibited NF-κB activation. The present study provides strong evidence that at least some of the neuroprotective effects of curcumin against OGD/R are mediated by PPARγ activation. Copyright © 2014 Wiley Periodicals, Inc.

  19. Anti-inflammatory Activities and Gastric Ulcer-inducing Properties of Tetraacetylquercetin and Tetrapivaloylquercetin

    Directory of Open Access Journals (Sweden)

    Rina Herowati

    2016-12-01

    Full Text Available Quercetin (3,3’4’,5,7-pentahydroxyflavone has been reported to show anti-inflammatory activity. However, its low oral bioavailability limits the application of quercetin in therapy. Ester derivatives of quercetin have been reported to have higher bioavailability than quercetin. This research aimed to study the anti-inflammatory activities and gastric ulcer-inducing properties of tetraacetylquercetinas well as tetrapivaloylquercetin. Synthesis of tetra-acyl derivatives of quercetin was conducted using acetic anhydride or pivaloyl chloride in the presence of pyridine and the structure was confirmed by 1H-NMR and 13C-NMR spectroscopy as well as elemental analysis. At a dose of 20 mg/kg bw, oral administration of quercetin only showed 20% inhibition activity on carragenan induced rat paw edema, while tetraacetyl and tetrapivaloyl derivatives at equimolar dose showed 11-33% and 5-15% inhibition activity respectively. Contrary to the gastric ulcer healing-promoting action of quercetin, tetraacetylquercetin caused mild gastric ulcers. However, no gastric ulcer was observed after administration of tetrapivaloylquercetin. It was concluded that acylation enhances the anti-inflammatory activity of quercetin but causes mild gastric ulcers in the case of tetraacetylation.

  20. Ionizing radiation-induced MEK and Erk activation does not enhance survival of irradiated human squamous carcinoma cells

    International Nuclear Information System (INIS)

    Bonner, James A.; Vroman, Benjamin T.; Christianson, Teresa J.H.; Karnitz, Larry M.

    1998-01-01

    Purpose: Ionizing radiation (IR) triggers several intracellular signaling cascades that have commonly been regarded as mitogenic, including the Raf-MEK-Erk kinase cascade. In addition to promoting proliferation, activated MEK and Erk may also prevent cell death induced by cytotoxic stimuli. Because Raf, MEK, and Erk are activated by IR in some tumor cell lines, this suggests that IR-induced activation of the kinase cascade may enhance the survival of irradiated cells. Methods and Materials: IR-induced activation of MEK and Erk was assessed in irradiated UM-SCC-6 cells, a human squamous carcinoma cell line. Activation of MEK and Erk was blocked with the pharmacological inhibitor of MEK activation, PD098059. Clonogenic survival was assessed in irradiated UM-SCC-6 cells that were pretreated with nothing or with the MEK inhibitor. Results: In UM-SCC-6 cells, IR doses as low as 2 Gy rapidly activated MEK and Erk. Pretreatment of the cells with the pharmacological inhibitor of MEK activation, PD098059, effectively blocked IR-induced activation of MEK and Erk. However, inhibition of the kinase cascade did not affect the clonogenic survival of irradiated cells in either early or delayed-plating experiments. Conclusion: Taken together, these results suggest that although MEK and Erk are rapidly activated by IR treatment, these protein kinases do not affect the clonogenic survival of irradiated UM-SCC6 cells

  1. Oscillatory brain activity in spontaneous and induced sleep stages in flies

    OpenAIRE

    Yap, Melvyn H. W.; Grabowska, Martyna J.; Rohrscheib, Chelsie; Jeans, Rhiannon; Troup, Michael; Paulk, Angelique C.; van Alphen, Bart; Shaw, Paul J.; van Swinderen, Bruno

    2017-01-01

    Sleep is a dynamic process comprising multiple stages, each associated with distinct electrophysiological properties and potentially serving different functions. While these phenomena are well described in vertebrates, it is unclear if invertebrates have distinct sleep stages. We perform local field potential (LFP) recordings on flies spontaneously sleeping, and compare their brain activity to flies induced to sleep using either genetic activation of sleep-promoting circuitry or the GABAA ago...

  2. The novel HDAC inhibitor AR-42-induced anti-colon cancer cell activity is associated with ceramide production

    International Nuclear Information System (INIS)

    Xu, Weihong; Xu, Bin; Yao, Yiting; Yu, Xiaoling; Shen, Jie

    2015-01-01

    In the current study, we investigated the potential activity of AR-42, a novel histone deacetylase (HDAC) inhibitor, against colon cancer cells. Our in vitro results showed that AR-42 induced ceramide production, exerted potent anti-proliferative and pro-apoptotic activities in established (SW-620 and HCT-116 lines) and primary human colon cancer cells. Exogenously-added sphingosine 1-phosphate (S1P) suppressed AR-42-induced activity, yet a cell-permeable ceramide (C4) facilitated AR-42-induced cytotoxicity against colon cancer cells. In addition, AR-42-induced ceramide production and anti-colon cancer cell activity were inhibited by the ceramide synthase inhibitor fumonisin B1, but were exacerbated by PDMP, which is a ceramide glucosylation inhibitor. In vivo, oral administration of a single dose of AR-42 dramatically inhibited SW-620 xenograft growth in severe combined immunodeficient (SCID) mice, without inducing overt toxicities. Together, these results show that AR-42 dramatically inhibits colon cancer cell proliferation in vitro and in vivo, and ceramide production might be the key mechanism responsible for its actions. - Highlights: • AR-42 is anti-proliferative against primary/established colon cancer cells. • AR-42 induces significant apoptotic death in primary/established colon cancer cells. • Ceramide production mediates AR-42-induced cytotoxicity in colon cancer cells. • AR-42 oral administration potently inhibits SW-620 xenograft growth in SCID mice

  3. The novel HDAC inhibitor AR-42-induced anti-colon cancer cell activity is associated with ceramide production

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Weihong; Xu, Bin; Yao, Yiting; Yu, Xiaoling [Department of Clinical Laboratory, Tongren Hospital, Shanghai (China); Shen, Jie, E-mail: tongrensj163@163.com [Department of Administrative, Tongren Hospital, No. 786 Yuyuan Road, Changning District, Shanghai (China)

    2015-08-07

    In the current study, we investigated the potential activity of AR-42, a novel histone deacetylase (HDAC) inhibitor, against colon cancer cells. Our in vitro results showed that AR-42 induced ceramide production, exerted potent anti-proliferative and pro-apoptotic activities in established (SW-620 and HCT-116 lines) and primary human colon cancer cells. Exogenously-added sphingosine 1-phosphate (S1P) suppressed AR-42-induced activity, yet a cell-permeable ceramide (C4) facilitated AR-42-induced cytotoxicity against colon cancer cells. In addition, AR-42-induced ceramide production and anti-colon cancer cell activity were inhibited by the ceramide synthase inhibitor fumonisin B1, but were exacerbated by PDMP, which is a ceramide glucosylation inhibitor. In vivo, oral administration of a single dose of AR-42 dramatically inhibited SW-620 xenograft growth in severe combined immunodeficient (SCID) mice, without inducing overt toxicities. Together, these results show that AR-42 dramatically inhibits colon cancer cell proliferation in vitro and in vivo, and ceramide production might be the key mechanism responsible for its actions. - Highlights: • AR-42 is anti-proliferative against primary/established colon cancer cells. • AR-42 induces significant apoptotic death in primary/established colon cancer cells. • Ceramide production mediates AR-42-induced cytotoxicity in colon cancer cells. • AR-42 oral administration potently inhibits SW-620 xenograft growth in SCID mice.

  4. Antibody-induced dimerization activates the epidermal growth factor receptor tyrosine kinase

    NARCIS (Netherlands)

    Spaargaren, M.; Defize, L. H.; Boonstra, J.; de Laat, S. W.

    1991-01-01

    The relationship between epidermal growth factor receptor (EGF-R) protein tyrosine kinase activation and ligand-induced receptor dimerization was investigated using several bivalent anti-EGF-R antibodies directed against various receptor epitopes. In A431 membrane preparations and permeabilized

  5. Noise-Induced Loss of Hair Cells and Cochlear Synaptopathy Are Mediated by the Activation of AMPK

    Science.gov (United States)

    Hill, Kayla; Yuan, Hu; Wang, Xianren

    2016-01-01

    Noise-induced hearing loss (NIHL) is a major unresolved public health problem. Here, we investigate pathomechanisms of sensory hair cell death and suggest a novel target for protective intervention. Cellular survival depends upon maintenance of energy homeostasis, largely by AMP-activated protein kinase (AMPK). In response to a noise exposure in CBA/J mice, the levels of phosphorylated AMPKα increased in hair cells in a noise intensity-dependent manner. Inhibition of AMPK via siRNA or the pharmacological inhibitor compound C attenuated noise-induced loss of outer hair cells (OHCs) and synaptic ribbons, and preserved auditory function. Additionally, noise exposure increased the activity of the upstream AMPK kinase liver kinase B1 (LKB1) in cochlear tissues. The inhibition of LKB1 by siRNA attenuated the noise-increased phosphorylation of AMPKα in OHCs, reduced the loss of inner hair cell synaptic ribbons and OHCs, and protected against NIHL. These results indicate that noise exposure induces hair cell death and synaptopathy by activating AMPK via LKB1-mediated pathways. Targeting these pathways may provide a novel route to prevent NIHL. SIGNIFICANCE STATEMENT Our results demonstrate for the first time that the activation of AMP-activated protein kinase (AMPK) α in sensory hair cells is noise intensity dependent and contributes to noise-induced hearing loss by mediating the loss of inner hair cell synaptic ribbons and outer hair cells. Noise induces the phosphorylation of AMPKα1 by liver kinase B1 (LKB1), triggered by changes in intracellular ATP levels. The inhibition of AMPK activation by silencing AMPK or LKB1, or with the pharmacological inhibitor compound C, reduced outer hair cell and synaptic ribbon loss as well as noise-induced hearing loss. This study provides new insights into mechanisms of noise-induced hearing loss and suggests novel interventions for the prevention of the loss of sensory hair cells and cochlear synaptopathy. PMID:27413159

  6. Noise-Induced Loss of Hair Cells and Cochlear Synaptopathy Are Mediated by the Activation of AMPK.

    Science.gov (United States)

    Hill, Kayla; Yuan, Hu; Wang, Xianren; Sha, Su-Hua

    2016-07-13

    Noise-induced hearing loss (NIHL) is a major unresolved public health problem. Here, we investigate pathomechanisms of sensory hair cell death and suggest a novel target for protective intervention. Cellular survival depends upon maintenance of energy homeostasis, largely by AMP-activated protein kinase (AMPK). In response to a noise exposure in CBA/J mice, the levels of phosphorylated AMPKα increased in hair cells in a noise intensity-dependent manner. Inhibition of AMPK via siRNA or the pharmacological inhibitor compound C attenuated noise-induced loss of outer hair cells (OHCs) and synaptic ribbons, and preserved auditory function. Additionally, noise exposure increased the activity of the upstream AMPK kinase liver kinase B1 (LKB1) in cochlear tissues. The inhibition of LKB1 by siRNA attenuated the noise-increased phosphorylation of AMPKα in OHCs, reduced the loss of inner hair cell synaptic ribbons and OHCs, and protected against NIHL. These results indicate that noise exposure induces hair cell death and synaptopathy by activating AMPK via LKB1-mediated pathways. Targeting these pathways may provide a novel route to prevent NIHL. Our results demonstrate for the first time that the activation of AMP-activated protein kinase (AMPK) α in sensory hair cells is noise intensity dependent and contributes to noise-induced hearing loss by mediating the loss of inner hair cell synaptic ribbons and outer hair cells. Noise induces the phosphorylation of AMPKα1 by liver kinase B1 (LKB1), triggered by changes in intracellular ATP levels. The inhibition of AMPK activation by silencing AMPK or LKB1, or with the pharmacological inhibitor compound C, reduced outer hair cell and synaptic ribbon loss as well as noise-induced hearing loss. This study provides new insights into mechanisms of noise-induced hearing loss and suggests novel interventions for the prevention of the loss of sensory hair cells and cochlear synaptopathy. Copyright © 2016 the authors 0270-6474/16/367497-14$15.00/0.

  7. Polaprezinc reduces paclitaxel-induced peripheral neuropathy in rats without affecting anti-tumor activity

    Directory of Open Access Journals (Sweden)

    Kuniaki Tsutsumi

    2016-06-01

    Full Text Available Paclitaxel, an anticancer drug, frequently causes painful peripheral neuropathy. In this study, we investigated the preventive effect of polaprezinc on paclitaxel-induced peripheral neuropathy in rats. Polaprezinc (3 mg/kg, p.o., once daily inhibited the development of mechanical allodynia induced by paclitaxel (4 mg/kg, i.p., on days 1, 3, 5 and 7 and suppressed the paclitaxel-induced increase in macrophage migration in dorsal root ganglion cells. In addition, polaprezinc did not affect the anti-tumor activity of paclitaxel in cultured cell lines or tumor-bearing mice. These results suggest a clinical indication for polaprezinc in the prevention of paclitaxel-induced neuropathy.

  8. Gender Differences in Global but Not Targeted Demethylation in iPSC Reprogramming

    Directory of Open Access Journals (Sweden)

    Inês Milagre

    2017-01-01

    Full Text Available Global DNA demethylation is an integral part of reprogramming processes in vivo and in vitro, but whether it occurs in the derivation of induced pluripotent stem cells (iPSCs is not known. Here, we show that iPSC reprogramming involves both global and targeted demethylation, which are separable mechanistically and by their biological outcomes. Cells at intermediate-late stages of reprogramming undergo transient genome-wide demethylation, which is more pronounced in female cells. Global demethylation requires activation-induced cytidine deaminase (AID-mediated downregulation of UHRF1 protein, and abolishing demethylation leaves thousands of hypermethylated regions in the iPSC genome. Independently of AID and global demethylation, regulatory regions, particularly ESC enhancers and super-enhancers, are specifically targeted for hypomethylation in association with transcription of the pluripotency network. Our results show that global and targeted DNA demethylation are conserved and distinct reprogramming processes, presumably because of their respective roles in epigenetic memory erasure and in the establishment of cell identity.

  9. Immunoglobulin class-switch recombination deficiencies.

    Science.gov (United States)

    Durandy, Anne; Kracker, Sven

    2012-07-30

    Immunoglobulin class-switch recombination deficiencies (Ig-CSR-Ds) are rare primary immunodeficiencies characterized by defective switched isotype (IgG/IgA/IgE) production. Depending on the molecular defect in question, the Ig-CSR-D may be combined with an impairment in somatic hypermutation (SHM). Some of the mechanisms underlying Ig-CSR and SHM have been described by studying natural mutants in humans. This approach has revealed that T cell-B cell interaction (resulting in CD40-mediated signaling), intrinsic B-cell mechanisms (activation-induced cytidine deaminase-induced DNA damage), and complex DNA repair machineries (including uracil-N-glycosylase and mismatch repair pathways) are all involved in class-switch recombination and SHM. However, several of the mechanisms required for full antibody maturation have yet to be defined. Elucidation of the molecular defects underlying the diverse set of Ig-CSR-Ds is essential for understanding Ig diversification and has prompted better definition of the clinical spectrum of diseases and the development of increasingly accurate diagnostic and therapeutic approaches.

  10. Piracetam prevents scopolamine-induced memory impairment and decrease of NTPDase, 5'-nucleotidase and adenosine deaminase activities.

    Science.gov (United States)

    Marisco, Patricia C; Carvalho, Fabiano B; Rosa, Michelle M; Girardi, Bruna A; Gutierres, Jessié M; Jaques, Jeandre A S; Salla, Ana P S; Pimentel, Víctor C; Schetinger, Maria Rosa C; Leal, Daniela B R; Mello, Carlos F; Rubin, Maribel A

    2013-08-01

    Piracetam improves cognitive function in animals and in human beings, but its mechanism of action is still not completely known. In the present study, we investigated whether enzymes involved in extracellular adenine nucleotide metabolism, adenosine triphosphate diphosphohydrolase (NTPDase), 5'-nucleotidase and adenosine deaminase (ADA) are affected by piracetam in the hippocampus and cerebral cortex of animals subjected to scopolamine-induced memory impairment. Piracetam (0.02 μmol/5 μL, intracerebroventricular, 60 min pre-training) prevented memory impairment induced by scopolamine (1 mg/kg, intraperitoneal, immediately post-training) in the inhibitory avoidance learning and in the object recognition task. Scopolamine reduced the activity of NTPDase in hippocampus (53 % for ATP and 53 % for ADP hydrolysis) and cerebral cortex (28 % for ATP hydrolysis). Scopolamine also decreased the activity of 5'-nucleotidase (43 %) and ADA (91 %) in hippocampus. The same effect was observed in the cerebral cortex for 5'-nucleotidase (38 %) and ADA (68 %) activities. Piracetam fully prevented scopolamine-induced memory impairment and decrease of NTPDase, 5'-nucleotidase and adenosine deaminase activities in synaptosomes from cerebral cortex and hippocampus. In vitro experiments show that piracetam and scopolamine did not alter enzymatic activity in cerebral cortex synaptosomes. Moreover, piracetam prevented scopolamine-induced increase of TBARS levels in hippocampus and cerebral cortex. These results suggest that piracetam-induced improvement of memory is associated with protection against oxidative stress and maintenance of NTPDase, 5'-nucleotidase and ADA activities, and suggest the purinergic system as a putative target of piracetam.

  11. Substance P spinal signaling induces glial activation and nociceptive sensitization after fracture

    OpenAIRE

    Li, Wen-Wu; Guo, Tian-Zhi; Shi, Xiaoyou; Sun, Yuan; Wei, Tzuping; Clark, David J; Kingery, Wade S

    2015-01-01

    Tibia fracture in rodents induces substance P (SP)-dependent keratinocyte activation and inflammatory changes in the hindlimb, similar to those seen in complex regional pain syndrome (CRPS). In animal pain models spinal glial cell activation results in nociceptive sensitization. This study tested the hypothesis that limb fracture triggers afferent C-fiber SP release in the dorsal horn, resulting in chronic glia activation and central sensitization. At 4 weeks after tibia fracture and casting ...

  12. A preliminary census of engineering activities located in Sicily (Southern Italy) which may "potentially" induce seismicity

    Science.gov (United States)

    Aloisi, Marco; Briffa, Emanuela; Cannata, Andrea; Cannavò, Flavio; Gambino, Salvatore; Maiolino, Vincenza; Maugeri, Roberto; Palano, Mimmo; Privitera, Eugenio; Scaltrito, Antonio; Spampinato, Salvatore; Ursino, Andrea; Velardita, Rosanna

    2015-04-01

    The seismic events caused by human engineering activities are commonly termed as "triggered" and "induced". This class of earthquakes, though characterized by low-to-moderate magnitude, have significant social and economical implications since they occur close to the engineering activity responsible for triggering/inducing them and can be felt by the inhabitants living nearby, and may even produce damage. One of the first well-documented examples of induced seismicity was observed in 1932 in Algeria, when a shallow magnitude 3.0 earthquake occurred close to the Oued Fodda Dam. By the continuous global improvement of seismic monitoring networks, numerous other examples of human-induced earthquakes have been identified. Induced earthquakes occur at shallow depths and are related to a number of human activities, such as fluid injection under high pressure (e.g. waste-water disposal in deep wells, hydrofracturing activities in enhanced geothermal systems and oil recovery, shale-gas fracking, natural and CO2 gas storage), hydrocarbon exploitation, groundwater extraction, deep underground mining, large water impoundments and underground nuclear tests. In Italy, induced/triggered seismicity is suspected to have contributed to the disaster of the Vajont dam in 1963. Despite this suspected case and the presence in the Italian territory of a large amount of engineering activities "capable" of inducing seismicity, no extensive researches on this topic have been conducted to date. Hence, in order to improve knowledge and correctly assess the potential hazard at a specific location in the future, here we started a preliminary study on the entire range of engineering activities currently located in Sicily (Southern Italy) which may "potentially" induce seismicity. To this end, we performed: • a preliminary census of all engineering activities located in the study area by collecting all the useful information coming from available on-line catalogues; • a detailed compilation

  13. Curcumin attenuates lipopolysaccharide/d-galactosamine-induced acute liver injury by activating Nrf2 nuclear translocation and inhibiting NF-kB activation.

    Science.gov (United States)

    Xie, Yi-Lian; Chu, Jin-Guo; Jian, Xiao-Min; Dong, Jin-Zhong; Wang, Li-Ping; Li, Guo-Xiang; Yang, Nai-Bin

    2017-07-01

    Curcumin, a polyphenol in curry spice isolated from the rhizome of turmeric, has been reported to possess versatile biological properties including anti-inflammatory, anti-oxidant, antifibrotic, and anticancer activities. In this study, the hepatoprotective effect of curcumin was investigated in lipopolysaccharide (LPS)/d-galactosamine (d-GalN)-induced acute liver injury (ALI) in rats. Experimental ALI was induced with an intraperitoneal (ip) injection of sterile 0.9% sodium chloride (NaCl) solution containing 8μg LPS and 800mg/kg d-GalN. Curcumin was administered once daily starting three days prior to LPS/d-GalN treatment. Results indicated that curcumin could attenuate hepatic pathological damage, decrease serum ALT and AST levels, and reduce malondialdehyde (MDA) content in experimental ALI rats. Moreover, higher dosages of curcumin pretreatment inhibited NF-κB activation and reduced serum TNF-α and liver TNF-α levels induced by LPS/d-GalN ip injection. Furthermore, we found that curcumin up-regulated the expression of nuclear Nrf2 and Nrf2-dependent antioxidant defense genes including heme oxygenase-1 (HO-1), glutamate-cysteine ligase (GCLC), NAD(P)H dehydrogenase, and quinone (NQO-1) in a dose-dependent manner. Our results showed that curcumin protected experimental animals against LPS/d-GalN-induced ALI through activation of Nrf2 nuclear translocation and inhibition of NF-κB activation. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  14. PMA Induces Vaccine Adjuvant Activity by the Modulation of TLR Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Dool-Ri Oh

    2014-01-01

    Full Text Available Toll-like receptor (TLR ligands are being developed for use as vaccine adjuvants and as immunomodulators because of their ability to stimulate innate and adaptive immune responses. Flagellin, a TLR5 ligand, was reported to show potent mucosal vaccine adjuvant activity. To identify ligands that potentiate the adjuvant activity of flagellin, we screened a plant library using HEK293T cells transiently cotransfected with phTLR5 and pNF-κB-SEAP plasmids. The 90% EtOH extract from Croton tiglium showed significant NF-κB transactivation in a TLR5-independent manner along with the increase of a flagellin activity. We have studied to characterize an active component from Croton tiglium and to elucidate the action mechanisms. Phorbol 12-myristate 13-acetate (PMA was isolated as an active component of Croton tiglium by activity-guided fractionation, column chromatography, HPLC, NMR, and MS. PMA at a range of nM induced PKC-dependent NF-κB activation and IL-8 production in both TLR5− and TLR5+ assay systems. In in vivo mouse vaccination model, PMA induced antigen-specific IgG and IgA antibody responses and increased IL-12 production corresponding to T cell responses in spleen lymphocytes. These results suggest that PMA would serve as an efficacious mucosal vaccine adjuvant.

  15. Autophagy Facilitates IFN-γ-induced Jak2-STAT1 Activation and Cellular Inflammation*

    Science.gov (United States)

    Chang, Yu-Ping; Tsai, Cheng-Chieh; Huang, Wei-Ching; Wang, Chi-Yun; Chen, Chia-Ling; Lin, Yee-Shin; Kai, Jui-In; Hsieh, Chia-Yuan; Cheng, Yi-Lin; Choi, Pui-Ching; Chen, Shun-Hua; Chang, Shih-Ping; Liu, Hsiao-Sheng; Lin, Chiou-Feng

    2010-01-01

    Autophagy is regulated for IFN-γ-mediated antimicrobial efficacy; however, its molecular effects for IFN-γ signaling are largely unknown. Here, we show that autophagy facilitates IFN-γ-activated Jak2-STAT1. IFN-γ induces autophagy in wild-type but not in autophagy protein 5 (Atg5−/−)-deficient mouse embryonic fibroblasts (MEFs), and, autophagy-dependently, IFN-γ induces IFN regulatory factor 1 and cellular inflammatory responses. Pharmacologically inhibiting autophagy using 3-methyladenine, a known inhibitor of class III phosphatidylinositol 3-kinase, confirms these effects. Either Atg5−/− or Atg7−/− MEFs are, independent of changes in IFN-γ receptor expression, resistant to IFN-γ-activated Jak2-STAT1, which suggests that autophagy is important for IFN-γ signal transduction. Lentivirus-based short hairpin RNA for Atg5 knockdown confirmed the importance of autophagy for IFN-γ-activated STAT1. Without autophagy, reactive oxygen species increase and cause SHP2 (Src homology-2 domain-containing phosphatase 2)-regulated STAT1 inactivation. Inhibiting SHP2 reversed both cellular inflammation and the IFN-γ-induced activation of STAT1 in Atg5−/− MEFs. Our study provides evidence that there is a link between autophagy and both IFN-γ signaling and cellular inflammation and that autophagy, because it inhibits the expression of reactive oxygen species and SHP2, is pivotal for Jak2-STAT1 activation. PMID:20592027

  16. Parenteral medium-chain triglyceride-induced neutrophil activation is not mediated by a Pertussis Toxin sensitive receptor.

    Science.gov (United States)

    Versleijen, Michelle W J; van Esterik, Joantine C J; Roelofs, Hennie M J; van Emst-de Vries, Sjenet E; Willems, Peter H G M; Wanten, Geert J A

    2009-02-01

    Lipid-induced immune modulation might contribute to the increased infection rate that is observed in patients using parenteral nutrition. We previously showed that emulsions containing medium-chain triglycerides (LCT/MCTs or pure MCTs), but not pure long-chain triglycerides (LCTs), impair neutrophil functions, modulate cell-signaling and induce neutrophil activation in vitro. It has recently been shown that medium-chain fatty acids are ligands for GPR84, a pertussis toxin (PT)-sensitive G-protein-coupled receptor (GPCR). This finding urged us to investigate whether MCT-induced neutrophil activation is mediated by PT-sensitive GPCRs. Neutrophils isolated from blood of healthy volunteers were pre-incubated with PT (0.5-1 microg/mL, 1.5 h) and analyzed for the effect of this pre-incubation on LCT/MCT (2.5 mmol/L)-dependent modulation of serum-treated zymosan (STZ)-induced intracellular Ca(2+) mobilization and on LCT/MCT (5 mmol/L)-induced expression of cell surface adhesion (CD11b) and degranulation (CD66b) markers and oxygen radical (ROS) production. PT did not inhibit the effects of LCT/MCT on the STZ-induced increase in cytosolic free Ca(2+) concentration. LCT/MCT increased ROS production to 146% of unstimulated cells. However, pre-incubation with PT did not inhibit the LCT/MCT-induced ROS production. Furthermore, the LCT/MCT-induced increase in CD11b and CD66b expression (196% and 235% of unstimulated cells, respectively) was not inhibited by pre-incubation with PT. LCT/MCT-induced neutrophil activation does not involve the action of a PT-sensitive G-protein-coupled receptor.

  17. 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.

  18. Extracts of Artocarpus communis Induce Mitochondria-Associated Apoptosis via Pro-oxidative Activity in Human Glioblastoma Cells

    Directory of Open Access Journals (Sweden)

    Chiang-Wen Lee

    2018-05-01

    Full Text Available Glioblastoma multiforme (GBM is an extremely aggressive and devastating malignant tumor in the central nervous system. Its incidence is increasing and the prognosis is poor. Artocarpin is a natural prenylated flavonoid with various anti-inflammatory and anti-tumor properties. Studies have shown that artocarpin is associated with cell death of primary glioblastoma cells. However, the in vivo effects and the cellular and molecular mechanisms modulating the anticancer activities of artocarpin remain unknown. In this study, we demonstrated that treating the glioblastoma cell lines U87 and U118 cells with artocarpin induced apoptosis. Artocarpin-induced apoptosis is associated with caspase activation and poly (ADP-ribose polymerase (PARP cleavage and is mediated by the mitochondrial pathway. This is associated with mitochondrial depolarization, mitochondrial-derived reactive oxidative species (ROS production, cytochrome c release, Bad and Bax upregulations, and Bcl-2 downregulation. Artocarpin induced NADPH oxidase/ROS generation plays an important role in the mitochondrial pathway activation. Furthermore, we found artocarpin-induced ROS production in mitochondria is associated with Akt- and ERK1/2 activation. After treatment with artocarpin, ROS causes PI3K/Akt/ERK1/2-induced cell death of these tumor cells. These observations were further verified by the results from the implantation of both U87 and U118 cells into in vivo mouse. In conclusion, our findings suggest that artocarpin induces mitochondria-associated apoptosis of glioma cells, suggesting that artocarpine can be a potential chemotherapeutic agent for future GBM treatment.

  19. The VP7 Outer Capsid Protein of Rotavirus Induces Polyclonal B-Cell Activation

    Science.gov (United States)

    Blutt, Sarah E.; Crawford, Sue E.; Warfield, Kelly L.; Lewis, Dorothy E.; Estes, Mary K.; Conner, Margaret E.

    2004-01-01

    The early response to a homologous rotavirus infection in mice includes a T-cell-independent increase in the number of activated B lymphocytes in the Peyer's patches. The mechanism of this activation has not been previously determined. Since rotavirus has a repetitively arranged triple-layered capsid and repetitively arranged antigens can induce activation of B cells, one or more of the capsid proteins could be responsible for the initial activation of B cells during infection. To address this question, we assessed the ability of rotavirus and virus-like particles to induce B-cell activation in vivo and in vitro. Using infectious rotavirus, inactivated rotavirus, noninfectious but replication-competent virus, and virus-like particles, we determined that neither infectivity nor RNA was necessary for B-cell activation but the presence of the rotavirus outer capsid protein, VP7, was sufficient for murine B-cell activation. Preincubation of the virus with neutralizing VP7 antibodies inhibited B-cell activation. Polymyxin B treatment and boiling of the virus preparation were performed, which ruled out possible lipopolysaccharide contamination as the source of activation and confirmed that the structural conformation of VP7 is important for B-cell activation. These findings indicate that the structure and conformation of the outer capsid protein, VP7, initiate intestinal B-cell activation during rotavirus infection. PMID:15194774

  20. AMPK Activation Prevents and Reverses Drug-Induced Mitochondrial and Hepatocyte Injury by Promoting Mitochondrial Fusion and Function.

    Directory of Open Access Journals (Sweden)

    Sun Woo Sophie Kang

    Full Text Available Mitochondrial damage is the major factor underlying drug-induced liver disease but whether conditions that thwart mitochondrial injury can prevent or reverse drug-induced liver damage is unclear. A key molecule regulating mitochondria quality control is AMP activated kinase (AMPK. When activated, AMPK causes mitochondria to elongate/fuse and proliferate, with mitochondria now producing more ATP and less reactive oxygen species. Autophagy is also triggered, a process capable of removing damaged/defective mitochondria. To explore whether AMPK activation could potentially prevent or reverse the effects of drug-induced mitochondrial and hepatocellular damage, we added an AMPK activator to collagen sandwich cultures of rat and human hepatocytes exposed to the hepatotoxic drugs, acetaminophen or diclofenac. In the absence of AMPK activation, the drugs caused hepatocytes to lose polarized morphology and have significantly decreased ATP levels and viability. At the subcellular level, mitochondria underwent fragmentation and had decreased membrane potential due to decreased expression of the mitochondrial fusion proteins Mfn1, 2 and/or Opa1. Adding AICAR, a specific AMPK activator, at the time of drug exposure prevented and reversed these effects. The mitochondria became highly fused and ATP production increased, and hepatocytes maintained polarized morphology. In exploring the mechanism responsible for this preventive and reversal effect, we found that AMPK activation prevented drug-mediated decreases in Mfn1, 2 and Opa1. AMPK activation also stimulated autophagy/mitophagy, most significantly in acetaminophen-treated cells. These results suggest that activation of AMPK prevents/reverses drug-induced mitochondrial and hepatocellular damage through regulation of mitochondrial fusion and autophagy, making it a potentially valuable approach for treatment of drug-induced liver injury.

  1. AMPK Activation Prevents and Reverses Drug-Induced Mitochondrial and Hepatocyte Injury by Promoting Mitochondrial Fusion and Function

    Science.gov (United States)

    Taniane, Caitlin; Farrell, Geoffrey; Arias, Irwin M.; Lippincott-Schwartz, Jennifer; Fu, Dong

    2016-01-01

    Mitochondrial damage is the major factor underlying drug-induced liver disease but whether conditions that thwart mitochondrial injury can prevent or reverse drug-induced liver damage is unclear. A key molecule regulating mitochondria quality control is AMP activated kinase (AMPK). When activated, AMPK causes mitochondria to elongate/fuse and proliferate, with mitochondria now producing more ATP and less reactive oxygen species. Autophagy is also triggered, a process capable of removing damaged/defective mitochondria. To explore whether AMPK activation could potentially prevent or reverse the effects of drug-induced mitochondrial and hepatocellular damage, we added an AMPK activator to collagen sandwich cultures of rat and human hepatocytes exposed to the hepatotoxic drugs, acetaminophen or diclofenac. In the absence of AMPK activation, the drugs caused hepatocytes to lose polarized morphology and have significantly decreased ATP levels and viability. At the subcellular level, mitochondria underwent fragmentation and had decreased membrane potential due to decreased expression of the mitochondrial fusion proteins Mfn1, 2 and/or Opa1. Adding AICAR, a specific AMPK activator, at the time of drug exposure prevented and reversed these effects. The mitochondria became highly fused and ATP production increased, and hepatocytes maintained polarized morphology. In exploring the mechanism responsible for this preventive and reversal effect, we found that AMPK activation prevented drug-mediated decreases in Mfn1, 2 and Opa1. AMPK activation also stimulated autophagy/mitophagy, most significantly in acetaminophen-treated cells. These results suggest that activation of AMPK prevents/reverses drug-induced mitochondrial and hepatocellular damage through regulation of mitochondrial fusion and autophagy, making it a potentially valuable approach for treatment of drug-induced liver injury. PMID:27792760

  2. The psychedelic state induced by ayahuasca modulates the activity and connectivity of the default mode network.

    Directory of Open Access Journals (Sweden)

    Fernanda Palhano-Fontes

    Full Text Available The experiences induced by psychedelics share a wide variety of subjective features, related to the complex changes in perception and cognition induced by this class of drugs. A remarkable increase in introspection is at the core of these altered states of consciousness. Self-oriented mental activity has been consistently linked to the Default Mode Network (DMN, a set of brain regions more active during rest than during the execution of a goal-directed task. Here we used fMRI technique to inspect the DMN during the psychedelic state induced by Ayahuasca in ten experienced subjects. Ayahuasca is a potion traditionally used by Amazonian Amerindians composed by a mixture of compounds that increase monoaminergic transmission. In particular, we examined whether Ayahuasca changes the activity and connectivity of the DMN and the connection between the DMN and the task-positive network (TPN. Ayahuasca caused a significant decrease in activity through most parts of the DMN, including its most consistent hubs: the Posterior Cingulate Cortex (PCC/Precuneus and the medial Prefrontal Cortex (mPFC. Functional connectivity within the PCC/Precuneus decreased after Ayahuasca intake. No significant change was observed in the DMN-TPN orthogonality. Altogether, our results support the notion that the altered state of consciousness induced by Ayahuasca, like those induced by psilocybin (another serotonergic psychedelic, meditation and sleep, is linked to the modulation of the activity and the connectivity of the DMN.

  3. Cocaine induces astrocytosis through ER stress-mediated activation of autophagy

    Science.gov (United States)

    Periyasamy, Palsamy; Guo, Ming-Lei; Buch, Shilpa

    2016-01-01

    ABSTRACT Cocaine is known to induce inflammation, thereby contributing in part, to the pathogenesis of neurodegeneration. A recent study from our lab has revealed a link between macroautophagy/autophagy and microglial activation. The current study was aimed at investigating whether cocaine could also mediate activation of astrocytes and, whether this process involved induction of autophagy. Our findings demonstrated that cocaine mediated the activation of astrocytes by altering the levels of autophagy markers, such as BECN1, ATG5, MAP1LC3B-II, and SQSTM1 in both human A172 astrocytoma cells and primary human astrocytes. Furthermore, cocaine treatment resulted in increased formation of endogenous MAP1LC3B puncta in human astrocytes. Additionally, astrocytes transfected with the GFP-MAP1LC3B plasmid also demonstrated cocaine-mediated upregulation of the green fluorescent MAP1LC3B puncta. Cocaine-mediated induction of autophagy involved upstream activation of ER stress proteins such as EIF2AK3, ERN1, ATF6 since blockage of autophagy using either pharmacological or gene-silencing approaches, had no effect on cocaine-mediated induction of ER stress. Using both pharmacological and gene-silencing approaches to block either ER stress or autophagy, our findings demonstrated that cocaine-induced activation of astrocytes (measured by increased levels of GFAP) involved sequential activation of ER stress and autophagy. Cocaine-mediated-increased upregulation of GFAP correlated with increased expression of proinflammatory mediators such as TNF, IL1B, and IL6. In conclusion, these findings reveal an association between ER stress-mediated autophagy and astrogliosis in cocaine-treated astrocytes. Intervention of ER stress and/or autophagy signaling would thus be promising therapeutic targets for abrogating cocaine-mediated neuroinflammation. PMID:27337297

  4. Ejaculation Induced by the Activation of Crz Neurons Is Rewarding to Drosophila Males.

    Science.gov (United States)

    Zer-Krispil, Shir; Zak, Hila; Shao, Lisha; Ben-Shaanan, Shir; Tordjman, Lea; Bentzur, Assa; Shmueli, Anat; Shohat-Ophir, Galit

    2018-05-07

    The reward system is a collection of circuits that reinforce behaviors necessary for survival [1, 2]. Given the importance of reproduction for survival, actions that promote successful mating induce pleasurable feeling and are positively reinforced [3, 4]. This principle is conserved in Drosophila, where successful copulation is naturally rewarding to male flies, induces long-term appetitive memories [5], increases brain levels of neuropeptide F (NPF, the fly homolog of neuropeptide Y), and prevents ethanol, known otherwise as rewarding to flies [6, 7], from being rewarding [5]. It is not clear which of the multiple sensory and motor responses performed during mating induces perception of reward. Sexual interactions with female flies that do not reach copulation are not sufficient to reduce ethanol consumption [5], suggesting that only successful mating encounters are rewarding. Here, we uncoupled the initial steps of mating from its final steps and tested the ability of ejaculation to mimic the rewarding value of full copulation. We induced ejaculation by activating neurons that express the neuropeptide corazonin (CRZ) [8] and subsequently measured different aspects of reward. We show that activating Crz-expressing neurons is rewarding to male flies, as they choose to reside in a zone that triggers optogenetic stimulation of Crz neurons and display conditioned preference for an odor paired with the activation. Reminiscent of successful mating, repeated activation of Crz neurons increases npf levels and reduces ethanol consumption. Our results demonstrate that ejaculation stimulated by Crz/Crz-receptor signaling serves as an essential part of the mating reward mechanism in Drosophila. VIDEO ABSTRACT. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  5. Compound 13, an α1-selective small molecule activator of AMPK, inhibits Helicobacter pylori-induced oxidative stresses and gastric epithelial cell apoptosis

    International Nuclear Information System (INIS)

    Zhao, Hangyong; Zhu, Huanghuang; Lin, Zhou; Lin, Gang; Lv, Guoqiang

    2015-01-01

    Half of the world's population experiences Helicobacter pylori (H. pylori) infection, which is a main cause of gastritis, duodenal and gastric ulcer, and gastric cancers. In the current study, we investigated the potential role of compound 13 (C13), a novel α1-selective small molecule activator of AMP-activated protein kinase (AMPK), against H. pylori-induced cytotoxicity in cultured gastric epithelial cells (GECs). We found that C13 induced significant AMPK activation, evidenced by phosphorylation of AMPKα1 and ACC (acetyl-CoA carboxylase), in both primary and transformed GECs. Treatment of C13 inhibited H. pylori-induced GEC apoptosis. AMPK activation was required for C13-mediated GEC protection. Inhibition of AMPK kinase activity by the AMPK inhibitor Compound C, or silencing AMPKα1 expression by targeted-shRNAs, alleviated C13-induced GEC protective activities against H. pylori. Significantly, C13 inhibited H. pylori-induced reactive oxygen species (ROS) production in GECs. C13 induced AMPK-dependent expression of anti-oxidant gene heme oxygenase (HO-1) in GECs. Zinc protoporphyrin (ZnPP) and tin protoporphyrin (SnPP), two HO-1 inhibitors, not only suppressed C13-mediated ROS scavenging activity, but also alleviated its activity in GECs against H. pylori. Together, these results indicate that C13 inhibits H. pylori-induced ROS production and GEC apoptosis through activating AMPK–HO–1 signaling. - Highlights: • We synthesized compound 13 (C13), a α1-selective small molecule AMPK activator. • C13-induced AMPK activation requires α1 subunit in gastric epithelial cells (GECs). • C13 enhances Helicobacter pylori-induced pro-survival AMPK activation to inhibit GEC apoptosis. • C13 inhibits H. pylori-induced reactive oxygen species (ROS) production in GECs. • AMPK-heme oxygenase (HO-1) activation is required for C13-mediated anti-oxidant activity

  6. Compound 13, an α1-selective small molecule activator of AMPK, inhibits Helicobacter pylori-induced oxidative stresses and gastric epithelial cell apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Hangyong; Zhu, Huanghuang; Lin, Zhou; Lin, Gang; Lv, Guoqiang, E-mail: lvguoqiangwuxivip@163.com

    2015-08-07

    Half of the world's population experiences Helicobacter pylori (H. pylori) infection, which is a main cause of gastritis, duodenal and gastric ulcer, and gastric cancers. In the current study, we investigated the potential role of compound 13 (C13), a novel α1-selective small molecule activator of AMP-activated protein kinase (AMPK), against H. pylori-induced cytotoxicity in cultured gastric epithelial cells (GECs). We found that C13 induced significant AMPK activation, evidenced by phosphorylation of AMPKα1 and ACC (acetyl-CoA carboxylase), in both primary and transformed GECs. Treatment of C13 inhibited H. pylori-induced GEC apoptosis. AMPK activation was required for C13-mediated GEC protection. Inhibition of AMPK kinase activity by the AMPK inhibitor Compound C, or silencing AMPKα1 expression by targeted-shRNAs, alleviated C13-induced GEC protective activities against H. pylori. Significantly, C13 inhibited H. pylori-induced reactive oxygen species (ROS) production in GECs. C13 induced AMPK-dependent expression of anti-oxidant gene heme oxygenase (HO-1) in GECs. Zinc protoporphyrin (ZnPP) and tin protoporphyrin (SnPP), two HO-1 inhibitors, not only suppressed C13-mediated ROS scavenging activity, but also alleviated its activity in GECs against H. pylori. Together, these results indicate that C13 inhibits H. pylori-induced ROS production and GEC apoptosis through activating AMPK–HO–1 signaling. - Highlights: • We synthesized compound 13 (C13), a α1-selective small molecule AMPK activator. • C13-induced AMPK activation requires α1 subunit in gastric epithelial cells (GECs). • C13 enhances Helicobacter pylori-induced pro-survival AMPK activation to inhibit GEC apoptosis. • C13 inhibits H. pylori-induced reactive oxygen species (ROS) production in GECs. • AMPK-heme oxygenase (HO-1) activation is required for C13-mediated anti-oxidant activity.

  7. RECEPTOR POTENTIAL AND LIGHT-INDUCED MITOCHONDRIAL ACTIVATION IN BLOWFLY PHOTORECEPTOR MUTANTS

    NARCIS (Netherlands)

    MOJET, MH; TINBERGEN, J; STAVENGA, DG

    1991-01-01

    1. Simultaneous measurements of the receptor potential and the light-induced mitochondrial activation were performed in white-eyed blowflies Calliphora vicina, mutant chalky, and Lucilia cuprina, mutants w(F) and w'nss. The intensity dependence and the temporal dynamics were investigated. 2. The

  8. Cucurbitane Triterpenoid from Momordica charantia Induces Apoptosis and Autophagy in Breast Cancer Cells, in Part, through Peroxisome Proliferator-Activated Receptor γ Activation

    Directory of Open Access Journals (Sweden)

    Jing-Ru Weng

    2013-01-01

    Full Text Available Although the antitumor activity of the crude extract of wild bitter gourd (Momordica charantia L. has been reported, its bioactive constituents and the underlying mechanism remain undefined. Here, we report that 3β,7β-dihydroxy-25-methoxycucurbita-5,23-diene-19-al (DMC, a cucurbitane-type triterpene isolated from wild bitter gourd, induced apoptotic death in breast cancer cells through peroxisome proliferator-activated receptor (PPAR γ activation. Luciferase reporter assays indicated the ability of DMC to activate PPARγ, and pharmacological inhibition of PPARγ protected cells from DMC's antiproliferative effect. Western blot analysis indicated that DMC suppressed the expression of many PPARγ-targeted signaling effectors, including cyclin D1, CDK6, Bcl-2, XIAP, cyclooxygenase-2, NF-κB, and estrogen receptor α, and induced endoplasmic reticulum stress, as manifested by the induction of GADD153 and GRP78 expression. Moreover, DMC inhibited mTOR-p70S6K signaling through Akt downregulation and AMPK activation. The ability of DMC to activate AMPK in liver kinase (LK B1-deficient MDA-MB-231 cells suggests that this activation was independent of LKB1-regulated cellular metabolic status. However, DMC induced a cytoprotective autophagy presumably through mTOR inhibition, which could be overcome by the cotreatment with the autophagy inhibitor chloroquine. Together, the ability of DMC to modulate multiple PPARγ-targeted signaling pathways provides a mechanistic basis to account for the antitumor activity of wild bitter gourd.

  9. Down-regulation of histamine-induced endothelial cell activation as potential anti-atherosclerotic activity of peptides from Spirulina maxima.

    Science.gov (United States)

    Vo, Thanh-Sang; Kim, Se-Kwon

    2013-10-09

    Histamine, a potent inflammatory mediator, has been known to cause the pathogenesis of atherosclerosis. In this sense, two bioactive peptides P1 (LDAVNR; 686Da) and P2 (MMLDF; 655Da) purified from gastric enzymatic hydrolysate of Spirulina maxima were examined for their protective effects against early atherosclerotic responses induced by histamine in EA.hy926 endothelial cells. Interestingly, both P1 and P2 exhibited inhibitory activities on the production and expression of IL-6 and MCP-1. Furthermore, P1 and P2 inhibited the production of adhesion molecules including P-selectin and E-selectin, and thus reducing in vitro cell adhesion of monocyte onto endothelial cells. In addition, the production of intracellular reactive oxygen species was observed to reduce in the presence of P1 or P2. Notably, the inhibitory activities of P1 and P2 were found due to down-regulating Egr-1 expression via histamine receptor and PKCδ-dependent MAPKs activation pathway. These results suggest that peptides P1 and P2 from S. maxima are effective to suppress histamine-induced endothelial cell activation that may contribute to the prevention of early atherosclerosis. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Aspirin-induced AMP-activated protein kinase activation regulates the proliferation of vascular smooth muscle cells from spontaneously hypertensive rats

    International Nuclear Information System (INIS)

    Sung, Jin Young; Choi, Hyoung Chul

    2011-01-01

    Highlights: → Aspirin-induced AMPK phosphorylation was greater in VSMC from SHR than WKY. → Aspirin-induced AMPK phosphorylation inhibited proliferation of VSMC from SHR. → Low basal AMPK phosphorylation in SHR elicits increased VSMC proliferation. → Inhibition of AMPK restored decreased VSMC proliferation by aspirin in SHR. → Aspirin exerts anti-proliferative effect through AMPK activation in VSMC from SHR. -- Abstract: Acetylsalicylic acid (aspirin), used to reduce risk of cardiovascular disease, plays an important role in the regulation of cellular proliferation. However, mechanisms responsible for aspirin-induced growth inhibition are not fully understood. Here, we investigated whether aspirin may exert therapeutic effects via AMP-activated protein kinase (AMPK) activation in vascular smooth muscle cells (VSMC) from wistar kyoto rats (WKY) and spontaneously hypertensive rats (SHR). Aspirin increased AMPK and acetyl-CoA carboxylase phosphorylation in a time- and dose-dependent manner in VSMCs from WKY and SHR, but with greater efficacy in SHR. In SHR, a low basal phosphorylation status of AMPK resulted in increased VSMC proliferation and aspirin-induced AMPK phosphorylation inhibited proliferation of VSMCs. Compound C, an AMPK inhibitor, and AMPK siRNA reduced the aspirin-mediated inhibition of VSMC proliferation, this effect was more pronounced in SHR than in WKY. In VSMCs from SHR, aspirin increased p53 and p21 expression and inhibited the expression of cell cycle associated proteins, such as p-Rb, cyclin D, and cyclin E. These results indicate that in SHR VSMCs aspirin exerts anti-proliferative effects through the induction of AMPK phosphorylation.

  11. Aspirin-induced AMP-activated protein kinase activation regulates the proliferation of vascular smooth muscle cells from spontaneously hypertensive rats

    Energy Technology Data Exchange (ETDEWEB)

    Sung, Jin Young [Department of Pharmacology, College of Medicine, Yeungnam University, Daegu 705-717 (Korea, Republic of); Choi, Hyoung Chul, E-mail: hcchoi@med.yu.ac.kr [Department of Pharmacology, College of Medicine, Yeungnam University, Daegu 705-717 (Korea, Republic of)

    2011-05-06

    Highlights: {yields} Aspirin-induced AMPK phosphorylation was greater in VSMC from SHR than WKY. {yields} Aspirin-induced AMPK phosphorylation inhibited proliferation of VSMC from SHR. {yields} Low basal AMPK phosphorylation in SHR elicits increased VSMC proliferation. {yields} Inhibition of AMPK restored decreased VSMC proliferation by aspirin in SHR. {yields} Aspirin exerts anti-proliferative effect through AMPK activation in VSMC from SHR. -- Abstract: Acetylsalicylic acid (aspirin), used to reduce risk of cardiovascular disease, plays an important role in the regulation of cellular proliferation. However, mechanisms responsible for aspirin-induced growth inhibition are not fully understood. Here, we investigated whether aspirin may exert therapeutic effects via AMP-activated protein kinase (AMPK) activation in vascular smooth muscle cells (VSMC) from wistar kyoto rats (WKY) and spontaneously hypertensive rats (SHR). Aspirin increased AMPK and acetyl-CoA carboxylase phosphorylation in a time- and dose-dependent manner in VSMCs from WKY and SHR, but with greater efficacy in SHR. In SHR, a low basal phosphorylation status of AMPK resulted in increased VSMC proliferation and aspirin-induced AMPK phosphorylation inhibited proliferation of VSMCs. Compound C, an AMPK inhibitor, and AMPK siRNA reduced the aspirin-mediated inhibition of VSMC proliferation, this effect was more pronounced in SHR than in WKY. In VSMCs from SHR, aspirin increased p53 and p21 expression and inhibited the expression of cell cycle associated proteins, such as p-Rb, cyclin D, and cyclin E. These results indicate that in SHR VSMCs aspirin exerts anti-proliferative effects through the induction of AMPK phosphorylation.

  12. Gc-protein-derived macrophage activating factor counteracts the neuronal damage induced by oxaliplatin.

    Science.gov (United States)

    Morucci, Gabriele; Branca, Jacopo J V; Gulisano, Massimo; Ruggiero, Marco; Paternostro, Ferdinando; Pacini, Alessandra; Di Cesare Mannelli, Lorenzo; Pacini, Stefania

    2015-02-01

    Oxaliplatin-based regimens are effective in metastasized advanced cancers. However, a major limitation to their widespread use is represented by neurotoxicity that leads to peripheral neuropathy. In this study we evaluated the roles of a proven immunotherapeutic agent [Gc-protein-derived macrophage activating factor (GcMAF)] in preventing or decreasing oxaliplatin-induced neuronal damage and in modulating microglia activation following oxaliplatin-induced damage. The effects of oxaliplatin and of a commercially available formula of GcMAF [oleic acid-GcMAF (OA-GcMAF)] were studied in human neurons (SH-SY5Y cells) and in human microglial cells (C13NJ). Cell density, morphology and viability, as well as production of cAMP and expression of vascular endothelial growth factor (VEGF), markers of neuron regeneration [neuromodulin or growth associated protein-43 (Gap-43)] and markers of microglia activation [ionized calcium binding adaptor molecule 1 (Iba1) and B7-2], were determined. OA-GcMAF reverted the damage inflicted by oxaliplatin on human neurons and preserved their viability. The neuroprotective effect was accompanied by increased intracellular cAMP production, as well as by increased expression of VEGF and neuromodulin. OA-GcMAF did not revert the effects of oxaliplatin on microglial cell viability. However, it increased microglial activation following oxaliplatin-induced damage, resulting in an increased expression of the markers Iba1 and B7-2 without any concomitant increase in cell number. When neurons and microglial cells were co-cultured, the presence of OA-GcMAF significantly counteracted the toxic effects of oxaliplatin. Our results demonstrate that OA-GcMAF, already used in the immunotherapy of advanced cancers, may significantly contribute to neutralizing the neurotoxicity induced by oxaliplatin, at the same time possibly concurring to an integrated anticancer effect. The association between these two powerful anticancer molecules would probably produce

  13. Activated platelets release sphingosine 1-phosphate and induce hypersensitivity to noxious heat stimuli in vivo

    Directory of Open Access Journals (Sweden)

    Daniela eWeth

    2015-04-01

    Full Text Available At the site of injury activated platelets release various mediators, one of which is sphingosine 1-phosphate (S1P. It was the aim of this study to explore whether activated human platelets had a pronociceptive effect in an in vivo mouse model and whether this effect was based on the release of S1P and subsequent activation of neuronal S1P receptors 1 or 3. Human platelets were prepared in different concentrations (105/µl, 106/µl, 107/µl and assessed in mice with different genetic backgrounds (WT, S1P1fl/fl, SNS-S1P1-/-, S1P3-/-. Intracutaneous injections of activated human platelets induced a significant, dose-dependent hypersensitivity to noxious thermal stimulation. The degree of heat hypersensitivity correlated with the platelet concentration as well as the platelet S1P content and the amount of S1P released upon platelet activation as measured with LC MS/MS. Despite the significant correlations between S1P and platelet count, no difference in paw withdrawal latency (PWL was observed in mice with a global null mutation of the S1P3 receptor or a conditional deletion of the S1P1 receptor in nociceptive primary afferents. Furthermore, neutralisation of S1P with a selective anti-S1P antibody did not abolish platelet induced heat hypersensitivity. Our results suggest that activated platelets release S1P and induce heat hypersensitivity in vivo. However, the platelet induced heat hypersensitivity was caused by mediators other than S1P.

  14. Coculture-inducible bacteriocin activity of Lactobacillus plantarum strain J23 isolated from grape must.

    Science.gov (United States)

    Rojo-Bezares, Beatriz; Sáenz, Yolanda; Navarro, Laura; Zarazaga, Myriam; Ruiz-Larrea, Fernanda; Torres, Carmen

    2007-08-01

    Detection and characterization of bacteriocin production by Lactobacillus plantarum strain J23, recovered from a grape must sample in Spain, have been carried out. Bacteriocin activity was degraded by proteolytic enzymes (trypsin, alfa-chymotrypsin, papaine, protease, proteinase K and acid proteases), and it was stable at high temperatures (121 degrees C, 20min), in a wide range of pH (1-12), and after treatment with organic solvents. L. plantarum J23 showed antimicrobial activity against Oenococcus oeni, and a range of Lactobacillus and Pediococcus species. Bacteriocin production was detected in liquid media only when J23 was cocultivated with some inducing bacteria, and induction took place when intact cells or 55 degrees C heated cells of the inducer were cocultivated with J23, but not with their autoclaved cells. Bacteriocin activity of J23 was not induced by high initial J23 inocula, and it was detected in cocultures during the exponential phase. The presence of ethanol or acidic pH in the media reduced bacteriocin production in the cocultures of J23 with the inducing bacteria. The presence of plantaricin-related plnEF and plnJ genes was detected by PCR and sequencing. Nevertheless, negative results were obtained for plnA, plnK, plNC8, plS and plW genes.

  15. The influence of experimentally induced pain on shoulder muscle activity

    DEFF Research Database (Denmark)

    Diederichsen, L.P.; Winther, A.; Dyhre-Poulsen, P.

    2009-01-01

    muscles. EMG was recorded before pain, during pain and after pain had subsided and pain intensity was continuously scored on a visual analog scale (VAS). During abduction, experimentally induced pain in the supraspinatus muscle caused a significant decrease in activity of the anterior deltoid, upper......-105A degrees) at a speed of approximately 120A degrees/s, controlled by a metronome. During abduction, electromyographic (EMG) activity was recorded by intramuscular wire electrodes inserted in two deeply located shoulder muscles and by surface-electrodes over six superficially located shoulder...... trapezius and the infraspinatus and an increase in activity of lower trapezius and latissimus dorsi muscles. Following subacromial injection a significantly increased muscle activity was seen in the lower trapezius, the serratus anterior and the latissimus dorsi muscles. In conclusion, this study shows...

  16. Tumour Microenvironments Induce Expression of Urokinase Plasminogen Activator Receptor (uPAR) and Concomitant Activation of Gelatinolytic Enzymes

    Science.gov (United States)

    Magnussen, Synnøve; Hadler-Olsen, Elin; Latysheva, Nadezhda; Pirila, Emma; Steigen, Sonja E.; Hanes, Robert; Salo, Tuula; Winberg, Jan-Olof; Uhlin-Hansen, Lars; Svineng, Gunbjørg

    2014-01-01

    Background The urokinase plasminogen activator receptor (uPAR) is associated with poor prognosis in oral squamous cell carcinoma (OSCC), and increased expression of uPAR is often found at the invasive tumour front. The aim of the current study was to elucidate the role of uPAR in invasion and metastasis of OSCC, and the effects of various tumour microenvironments in these processes. Furthermore, we wanted to study whether the cells’ expression level of uPAR affected the activity of gelatinolytic enzymes. Methods The Plaur gene was both overexpressed and knocked-down in the murine OSCC cell line AT84. Tongue and skin tumours were established in syngeneic mice, and cells were also studied in an ex vivo leiomyoma invasion model. Soluble factors derived from leiomyoma tissue, as well as purified extracellular matrix (ECM) proteins, were assessed for their ability to affect uPAR expression, glycosylation and cleavage. Activity of gelatinolytic enzymes in the tissues were assessed by in situ zymography. Results We found that increased levels of uPAR did not induce tumour invasion or metastasis. However, cells expressing low endogenous levels of uPAR in vitro up-regulated uPAR expression both in tongue, skin and leiomyoma tissue. Various ECM proteins had no effect on uPAR expression, while soluble factors originating from the leiomyoma tissue increased both the expression and glycosylation of uPAR, and possibly also affected the proteolytic processing of uPAR. Tumours with high levels of uPAR, as well as cells invading leiomyoma tissue with up-regulated uPAR expression, all displayed enhanced activity of gelatinolytic enzymes. Conclusions Although high levels of uPAR are not sufficient to induce invasion and metastasis, the activity of gelatinolytic enzymes was increased. Furthermore, several tumour microenvironments have the capacity to induce up-regulation of uPAR expression, and soluble factors in the tumour microenvironment may have an important role in the

  17. Tumour microenvironments induce expression of urokinase plasminogen activator receptor (uPAR and concomitant activation of gelatinolytic enzymes.

    Directory of Open Access Journals (Sweden)

    Synnøve Magnussen

    Full Text Available The urokinase plasminogen activator receptor (uPAR is associated with poor prognosis in oral squamous cell carcinoma (OSCC, and increased expression of uPAR is often found at the invasive tumour front. The aim of the current study was to elucidate the role of uPAR in invasion and metastasis of OSCC, and the effects of various tumour microenvironments in these processes. Furthermore, we wanted to study whether the cells' expression level of uPAR affected the activity of gelatinolytic enzymes.The Plaur gene was both overexpressed and knocked-down in the murine OSCC cell line AT84. Tongue and skin tumours were established in syngeneic mice, and cells were also studied in an ex vivo leiomyoma invasion model. Soluble factors derived from leiomyoma tissue, as well as purified extracellular matrix (ECM proteins, were assessed for their ability to affect uPAR expression, glycosylation and cleavage. Activity of gelatinolytic enzymes in the tissues were assessed by in situ zymography.We found that increased levels of uPAR did not induce tumour invasion or metastasis. However, cells expressing low endogenous levels of uPAR in vitro up-regulated uPAR expression both in tongue, skin and leiomyoma tissue. Various ECM proteins had no effect on uPAR expression, while soluble factors originating from the leiomyoma tissue increased both the expression and glycosylation of uPAR, and possibly also affected the proteolytic processing of uPAR. Tumours with high levels of uPAR, as well as cells invading leiomyoma tissue with up-regulated uPAR expression, all displayed enhanced activity of gelatinolytic enzymes.Although high levels of uPAR are not sufficient to induce invasion and metastasis, the activity of gelatinolytic enzymes was increased. Furthermore, several tumour microenvironments have the capacity to induce up-regulation of uPAR expression, and soluble factors in the tumour microenvironment may have an important role in the regulation of posttranslational

  18. Activity of some Mexican medicinal plant extracts on carrageenan-induced rat paw edema.

    Science.gov (United States)

    Meckes, M; David-Rivera, A D; Nava-Aguilar, V; Jimenez, A

    2004-07-01

    The extracts obtained from 14 plants of the Mexican medicinal flora were assessed for anti-inflammatory activity by carrageenan-induced rat paw edema model. The i.p. administration of the extracts at a dose of 400 mg/kg produced a high reduction of edema with 70% of the plant extracts. Oenothera rosea methanol extract, Sphaeralcea angustifolia chloroform extract, Acaciafarnesiana, Larrea tridentata and Rubus coriifolius methanol extracts as well as the aqueous extract of Chamaedora tepejilote were demonstrated to be particularly active against the induced hind-paw edema. Moderate inhibition of edema formation was also demonstrated with the methanol extracts of Astianthus viminalis, Brickellia paniculata, C. tepejilote and Justicia spicigera.

  19. JS-K, a GST-activated nitric oxide generator, induces DNA double-strand breaks, activates DNA damage response pathways, and induces apoptosis in vitro and in vivo in human multiple myeloma cells.

    Science.gov (United States)

    Kiziltepe, Tanyel; Hideshima, Teru; Ishitsuka, Kenji; Ocio, Enrique M; Raje, Noopur; Catley, Laurence; Li, Chun-Qi; Trudel, Laura J; Yasui, Hiroshi; Vallet, Sonia; Kutok, Jeffery L; Chauhan, Dharminder; Mitsiades, Constantine S; Saavedra, Joseph E; Wogan, Gerald N; Keefer, Larry K; Shami, Paul J; Anderson, Kenneth C

    2007-07-15

    Here we investigated the cytotoxicity of JS-K, a prodrug designed to release nitric oxide (NO(*)) following reaction with glutathione S-transferases, in multiple myeloma (MM). JS-K showed significant cytotoxicity in both conventional therapy-sensitive and -resistant MM cell lines, as well as patient-derived MM cells. JS-K induced apoptosis in MM cells, which was associated with PARP, caspase-8, and caspase-9 cleavage; increased Fas/CD95 expression; Mcl-1 cleavage; and Bcl-2 phosphorylation, as well as cytochrome c, apoptosis-inducing factor (AIF), and endonuclease G (EndoG) release. Moreover, JS-K overcame the survival advantages conferred by interleukin-6 (IL-6) and insulin-like growth factor 1 (IGF-1), or by adherence of MM cells to bone marrow stromal cells. Mechanistic studies revealed that JS-K-induced cytotoxicity was mediated via NO(*) in MM cells. Furthermore, JS-K induced DNA double-strand breaks (DSBs) and activated DNA damage responses, as evidenced by neutral comet assay, as well as H2AX, Chk2 and p53 phosphorylation. JS-K also activated c-Jun NH(2)-terminal kinase (JNK) in MM cells; conversely, inhibition of JNK markedly decreased JS-K-induced cytotoxicity. Importantly, bortezomib significantly enhanced JS-K-induced cytotoxicity. Finally, JS-K is well tolerated, inhibits tumor growth, and prolongs survival in a human MM xenograft mouse model. Taken together, these data provide the preclinical rationale for the clinical evaluation of JS-K to improve patient outcome in MM.

  20. Isorhamnetin protects against oxidative stress by activating Nrf2 and inducing the expression of its target genes

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Ji Hye; Shin, Bo Yeon; Han, Jae Yun; Kim, Mi Gwang; Wi, Ji Eun [College of Pharmacy, Chosun University, Gwangju, 501-759 (Korea, Republic of); Kim, Young Woo; Cho, Il Je; Kim, Sang Chan [Medical Research Center for Globalization of Herbal Formulation, College of Korean Medicine, Daegu Haany University, Gyeongsan 712-715 (Korea, Republic of); Shin, Sang Mi [College of Pharmacy, Chosun University, Gwangju, 501-759 (Korea, Republic of); Ki, Sung Hwan, E-mail: shki@chosun.ac.kr [College of Pharmacy, Chosun University, Gwangju, 501-759 (Korea, Republic of)

    2014-01-15

    Isorhamentin is a 3′-O-methylated metabolite of quercetin, and has been reported to have anti-inflammatory and anti-proliferative effects. However, the effects of isorhamnetin on Nrf2 activation and on the expressions of its downstream genes in hepatocytes have not been elucidated. Here, we investigated whether isorhamnetin has the ability to activate Nrf2 and induce phase II antioxidant enzyme expression, and to determine the protective role of isorhamnetin on oxidative injury in hepatocytes. In HepG2 cells, isorhamnetin increased the nuclear translocation of Nrf2 in a dose- and time-dependent manner, and consistently, increased antioxidant response element (ARE) reporter gene activity and the protein levels of hemeoxygenase (HO-1) and of glutamate cysteine ligase (GCL), which resulted in intracellular GSH level increases. The specific role of Nrf2 in isorhamnetin-induced Nrf2 target gene expression was verified using an ARE-deletion mutant plasmid and Nrf2-knockout MEF cells. Deletion of the ARE in the promoter region of the sestrin2 gene, which is recently identified as the Nrf2 target gene by us, abolished the ability of isorhamnetin to increase luciferase activity. In addition, Nrf2 deficiency completely blocked the ability of isorhamnetin to induce HO-1 and GCL. Furthermore, isorhamnetin pretreatment blocked t-BHP-induced ROS production and reversed GSH depletion by t-BHP and consequently, due to reduced ROS levels, decreased t-BHP-induced cell death. In addition isorhamnetin increased ERK1/2, PKCδ and AMPK phosphorylation. Finally, we showed that Nrf2 deficiency blocked the ability of isorhamnetin to protect cells from injury induced by t-BHP. Taken together, our results demonstrate that isorhamnetin is efficacious in protecting hepatocytes against oxidative stress by Nrf2 activation and in inducing the expressions of its downstream genes. - Highlights: • We investigated the effect of isorhamnetin on Nrf2 activation. • Isorhamnetin increased Nrf2

  1. Electrically and hybrid-induced muscle activations: effects of muscle size and fiber type

    Directory of Open Access Journals (Sweden)

    Kelly Stratton

    2016-07-01

    Full Text Available The effect of three electrical stimulation (ES frequencies (10, 35, and 50 Hz on two muscle groups with different proportions of fast and slow twitch fibers (abductor pollicis brevis (APB and vastus lateralis (VL was explored. We evaluated the acute muscles’ responses individually and during hybrid activations (ES superimposed by voluntary activations. Surface electromyography (sEMG and force measurements were evaluated as outcomes. Ten healthy adults (mean age: 24.4 ± 2.5 years participated after signing an informed consent form approved by the university Institutional Review Board. Protocols were developed to: 1 compare EMG activities during each frequency for each muscle when generating 25% Maximum Voluntary Contraction (MVC force, and 2 compare EMG activities during each frequency when additional voluntary activation was superimposed over ES-induced 25% MVC to reach 50% and 75% MVC. Empirical mode decomposition (EMD was utilized to separate ES artifacts from voluntary muscle activation. For both muscles, higher stimulation frequency (35 and 50Hz induced higher electrical output detected at 25% of MVC, suggesting more recruitment with higher frequencies. Hybrid activation generated proportionally less electrical activity than ES alone. ES and voluntary activations appear to generate two different modes of muscle recruitment. ES may provoke muscle strength by activating more fatiguing fast acting fibers, but voluntary activation elicits more muscle coordination. Therefore, during the hybrid activation, less electrical activity may be detected due to recruitment of more fatigue-resistant deeper muscle fibers, not reachable by surface EMG.

  2. Activation of dopamine D3 receptors inhibits reward-related learning induced by cocaine.

    Science.gov (United States)

    Kong, H; Kuang, W; Li, S; Xu, M

    2011-03-10

    Memories of learned associations between the rewarding properties of drugs and environmental cues contribute to craving and relapse in humans. The mesocorticolimbic dopamine (DA) system is involved in reward-related learning induced by drugs of abuse. DA D3 receptors are preferentially expressed in mesocorticolimbic DA projection areas. Genetic and pharmacological studies have shown that DA D3 receptors suppress locomotor-stimulant effects of cocaine and reinstatement of cocaine-seeking behaviors. Activation of the extracellular signal-regulated kinase (ERK) induced by acute cocaine administration is also inhibited by D3 receptors. How D3 receptors modulate cocaine-induced reward-related learning and associated changes in cell signaling in reward circuits in the brain, however, have not been fully investigated. In the present study, we show that D3 receptor mutant mice exhibit potentiated acquisition of conditioned place preference (CPP) at low doses of cocaine compared to wild-type mice. Activation of ERK and CaMKIIα, but not the c-Jun N-terminal kinase and p38, in the nucleus accumbens, amygdala and prefrontal cortex is also potentiated in D3 receptor mutant mice compared to that in wild-type mice following CPP expression. These results support a model in which D3 receptors modulate reward-related learning induced by low doses of cocaine by inhibiting activation of ERK and CaMKIIα in reward circuits in the brain. Copyright © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.

  3. Aloin Suppresses Lipopolysaccharide-Induced Inflammatory Response and Apoptosis by Inhibiting the Activation of NF-κB

    Directory of Open Access Journals (Sweden)

    Xuan Luo

    2018-02-01

    Full Text Available Numerous herbal-derived natural products are excellent anti-inflammatory agents. Several studies have reported that aloin, the major anthraquinone glycoside obtained from the Aloe species, exhibits anti-inflammatory activity. However, the molecular mechanism of this activity is not well understood. In this report, we found that aloin suppresses lipopolysaccharide-induced pro-inflammatory cytokine secretion and nitric oxide production, and downregulates the expression of tumor necrosis factor alpha (TNF-α, interleukin 6 (IL-6, inducible nitric oxide synthase (iNOS, and cyclooxygenase-2 (COX-2. Aloin inhibits the phosphorylation and acetylation of the NF-κB p65 subunit by suppressing the upstream kinases p38 and Msk1, preventing LPS-induced p65 translocation to the nucleus. We have also shown that aloin inhibits LPS-induced caspase-3 activation and apoptotic cell death. Collectively, these findings suggest that aloin effectively suppresses the inflammatory response, primarily through the inhibition of NF-κB signaling.

  4. Troxerutin Reduces Kidney Damage against BDE-47-Induced Apoptosis via Inhibiting NOX2 Activity and Increasing Nrf2 Activity

    Directory of Open Access Journals (Sweden)

    Qun Shan

    2017-01-01

    Full Text Available 2,2,4,4-Tetrabromodiphenyl ether (BDE-47, one of the persistent organic pollutants, seriously influences the quality of life; however, its pathological mechanism remains unclear. Troxerutin is a flavonoid with pharmacological activity of antioxidation and anti-inflammation. In the present study, we investigated troxerutin against BDE-47-induced kidney cell apoptosis and explored the underlying mechanism. The results show that troxerutin reduced renal cell apoptosis and urinary protein secretion in BDE-47-treated mice. Western blot analysis shows that troxerutin supplement enhanced the ratio of Bcl-2/Bax; inhibited the release of cytochrome c from mitochondria, the activation of procaspase-9 and procaspase-3, and the cleavage of PARP; and reduced FAS, FASL, and caspase-8 levels induced by BDE-47. In addition, troxerutin decreased the production of reactive oxygen species (ROS and increased the activities of antioxidative enzymes. Furthermore, troxerutin blunted Nrf2 ubiquitylation, enhanced the activity of Nrf2, decreased the activity of NOX2, and ameliorated kidney oxidant status of BDE-47-treated mice. Together, these results confirm that troxerutin could alleviate the cytotoxicity of BDE-47 through antioxidation and antiapoptosis, which suggests that its protective mechanism is involved in the inhibition of apoptosis via suppressing NOX2 activity and increasing Nrf2 signaling pathway.

  5. Curcumin Modulates the Radiosensitivity of Colorectal Cancer Cells by Suppressing Constitutive and Inducible NF-κB Activity

    International Nuclear Information System (INIS)

    Sandur, Santosh K.; Deorukhkar, Amit; Pandey, Manoj K.; Pabon, Ana Maria B.S.; Shentu, Shujun; Guha, Sushovan; Aggarwal, Bharat B.; Krishnan, Sunil

    2009-01-01

    Purpose: Radiation therapy is an integral part of the preoperative treatment of rectal cancers. However, only a minority of patients achieve a complete pathologic response to therapy because of resistance of these tumors to radiation therapy. This resistance may be mediated by constitutively active pro-survival signaling pathways or by inducible/acquired mechanisms in response to radiation therapy. Simultaneous inhibition of these pathways can sensitize these tumors to radiation therapy. Methods and Materials: Human colorectal cancer cells were exposed to clinically relevant doses of gamma rays, and the mechanism of their radioresistance was investigated. We characterized the transcription factor nuclear factor-κB (NF-κB) activation as a mechanism of inducible radioresistance in colorectal cancer and used curcumin, the active ingredient in the yellow spice turmeric, to overcome this resistance. Results: Curcumin inhibited the proliferation and the post-irradiation clonogenic survival of multiple colorectal cancer cell lines. Radiation stimulated NF-κB activity in a dose- and time-dependent manner, whereas curcumin suppressed this radiation-induced NF-κB activation via inhibition of radiation-induced phosphorylation and degradation of inhibitor of κB alpha, inhibition of inhibitor of κB kinase activity, and inhibition of Akt phosphorylation. Curcumin also suppressed NF-κB-regulated gene products (Bcl-2, Bcl-x L , inhibitor of apoptosis protein-2, cyclooxygenase-2, and cyclin D1). Conclusions: Our results suggest that transient inducible NF-κB activation provides a prosurvival response to radiation that may account for development of radioresistance. Curcumin blocks this signaling pathway and potentiates the antitumor effects of radiation therapy.

  6. Activity/inactivity circadian rhythm shows high similarities between young obesity-induced rats and old rats.

    Science.gov (United States)

    Bravo Santos, R; Delgado, J; Cubero, J; Franco, L; Ruiz-Moyano, S; Mesa, M; Rodríguez, A B; Uguz, C; Barriga, C

    2016-03-01

    The objective of the present study was to compare differences between elderly rats and young obesity-induced rats in their activity/inactivity circadian rhythm. The investigation was motivated by the differences reported previously for the circadian rhythms of both obese and elderly humans (and other animals), and those of healthy, young or mature individuals. Three groups of rats were formed: a young control group which was fed a standard chow for rodents; a young obesity-induced group which was fed a high-fat diet for four months; and an elderly control group with rats aged 2.5 years that was fed a standard chow for rodents. Activity/inactivity data were registered through actimetry using infrared actimeter systems in each cage to detect activity. Data were logged on a computer and chronobiological analysis were performed. The results showed diurnal activity (sleep time), nocturnal activity (awake time), amplitude, acrophase, and interdaily stability to be similar between the young obesity-induced group and the elderly control group, but different in the young control group. We have concluded that obesity leads to a chronodisruption status in the body similar to the circadian rhythm degradation observed in the elderly.

  7. Inhibition of STAT3 activity delays obesity-induced thyroid carcinogenesis in a mouse model

    Science.gov (United States)

    Park, Jeong Won; Han, Cho Rong; Zhao, Li; Willingham, Mark C.; Cheng, Sheue-yann

    2015-01-01

    Compelling epidemiologic studies indicate that obesity is a risk factor for many human cancers, including thyroid cancer. In recent decades, the incidence of thyroid cancer has dramatically increased along with a marked rise in obesity prevalence. We previously demonstrated that a high fat diet (HFD) effectively induced the obese phenotype in a mouse model of thyroid cancer (ThrbPV/PVPten+/− mice). Moreover, HFD activates the STAT3 signal pathway to promote more aggressive tumor phenotypes. The aim of the present study was to evaluate the effect of S3I-201, a specific inhibitor of STAT3 activity, on HFD-induced aggressive cancer progression in the mouse model of thyroid cancer. Wild type and ThrbPV/PVPten+/− mice were treated with HFD together with S3I-201 or vehicle-only as controls. We assessed the effects of S3I-201 on HFD-induced thyroid cancer progression, the leptin-JAK2-STAT3 signaling pathway, and key regulators of epithelial-mesenchymal transition. S3I-201 effectively inhibited HFD-induced aberrant activation of STAT3 and its downstream targets to markedly inhibit thyroid tumor growth and to prolong survival. Decreased protein levels of cyclins D1 and B1, cyclin dependent kinase (CDK) 4, CDK 6, and phosphorylated retinoblastoma protein led to the inhibition of tumor cell proliferation in S3I-201-treated ThrbPV/PVPten+/− mice. Reduced occurrence of vascular invasion and blocking of anaplasia and lung metastasis in thyroid tumors of S3I-201-treated ThrbPV/PVPten+/− mice were mediated via decreased expression of vimentin and matrix metalloproteinases, two key effectors of epithelial-mesenchymal transition. The present findings suggest that inhibition of the STAT3 activity would be a novel treatment strategy for obesity-induced thyroid cancer. PMID:26552408

  8. Short-chain C6 ceramide sensitizes AT406-induced anti-pancreatic cancer cell activity

    International Nuclear Information System (INIS)

    Zhao, Xiaoguang; Sun, Baoyou; Zhang, Jingjing; Zhang, Ruishen; Zhang, Qing

    2016-01-01

    Our previous study has shown that AT406, a first-in-class small molecular antagonist of IAPs (inhibitor of apoptosis proteins), inhibits pancreatic cancer cell proliferation in vitro and in vivo. The aim of this research is to increase AT406's sensitivity by adding short-chain C6 ceramide. We show that co-treatment of C6 ceramide dramatically potentiated AT406-induced caspase/apoptosis activation and cytotoxicity in established (Panc-1 and Mia-PaCa-2 lines) and primary human pancreatic cancer cells. Reversely, caspase inhibitors largely attenuated C6 ceramide plus AT406-induced above cancer cell death. Molecularly, C6 ceramide downregulated Bcl-2 to increase AT406's sensitivity in pancreatic cancer cells. Intriguingly, C6 ceramide-mediated AT406 sensitization was nullified with Bcl-2 shRNA knockdown or pretreatment of the Bcl-2 inhibitor ABT-737. In vivo, liposomal C6 ceramide plus AT406 co-administration dramatically inhibited Panc-1 xenograft tumor growth in severe combined immunodeficient (SCID) mice. The combined anti-tumor activity was significantly more potent than either single treatment. Expressions of IAPs (cIAP1/XIAP) and Bcl-2 were downregulated in Panc-1 xenografts with the co-administration. Together, we demonstrate that C6 ceramide sensitizes AT406-mediated anti-pancreatic cancer cell activity possibly via downregulating Bcl-2. - Highlights: • C6 ceramide dramatically potentiates AT406-induced pancreatic cancer cell death. • C6 ceramide facilitates AT406-induced pancreatic cancer cell apoptosis. • C6 ceramide downregulates Bcl-2 to increase AT406's sensitivity in pancreatic cancer cells. • Liposomal C6 ceramide enhances AT406-induced anti-pancreatic cancer activity in vivo.

  9. Leptin induces CYP1B1 expression in MCF-7 cells through ligand-independent activation of the ERα pathway

    Energy Technology Data Exchange (ETDEWEB)

    Khanal, Tilak; Kim, Hyung Gyun; Do, Minh Truong; Choi, Jae Ho; Won, Seong Su [Department of Toxicology, College of Pharmacy, Chungnam National University, Daejeon (Korea, Republic of); Kang, Wonku [College of Pharmacy, Yeungnam University, Gyeongsan (Korea, Republic of); Chung, Young Chul [Department of Food Science and Culinary, International University of Korea, Jinju (Korea, Republic of); Jeong, Tae Cheon, E-mail: taecheon@ynu.ac.kr [College of Pharmacy, Yeungnam University, Gyeongsan (Korea, Republic of); Jeong, Hye Gwang, E-mail: hgjeong@cnu.ac.kr [Department of Toxicology, College of Pharmacy, Chungnam National University, Daejeon (Korea, Republic of)

    2014-05-15

    Leptin, a hormone with multiple biological actions, is produced predominantly by adipose tissue. Among its functions, leptin can stimulate tumour cell growth. Oestrogen receptor α (ERα), which plays an essential role in breast cancer development, can be transcriptionally activated in a ligand-independent manner. In this study, we investigated the effect of leptin on CYP1B1 expression and its mechanism in breast cancer cells. Leptin induced CYP1B1 protein, messenger RNA expression and promoter activity in ERα-positive MCF-7 cells but not in ERα-negative MDA-MB-231 cells. Additionally, leptin increased 4-hydroxyoestradiol in MCF-7 cells. Also, ERα knockdown by siRNA significantly blocked the induction of CYP1B1 expression by leptin, indicating that leptin induced CYP1B1 expression via an ERα-dependent mechanism. Transient transfection with CYP1B1 deletion promoter constructs revealed that the oestrogen response element (ERE) plays important role in the up-regulation of CYP1B1 by leptin. Furthermore, leptin stimulated phosphorylation of ERα at serine residues 118 and 167 and increased ERE-luciferase activity, indicating that leptin induced CYP1B1 expression by ERα activation. Finally, we found that leptin activated ERK and Akt signalling pathways, which are upstream kinases related to ERα phosphorylation induced by leptin. Taken together, our results indicate that leptin-induced CYP1B1 expression is mediated by ligand-independent activation of the ERα pathway as a result of the activation of ERK and Akt in MCF-7 cells. - Highlights: • Leptin increased 4-hydroxyoestradiol in MCF-7 breast cancer cells. • Leptin activated ERK and Akt kinases related to ERα phosphorylation. • Leptin induces phosphorylation of ERα at serine residues 118 and 167. • Leptin induces ERE-luciferase activity.

  10. Matriptase is required for the active form of hepatocyte growth factor induced Met, focal adhesion kinase and protein kinase B activation on neural stem/progenitor cell motility.

    Science.gov (United States)

    Fang, Jung-Da; Lee, Sheau-Ling

    2014-07-01

    Hepatocyte growth factor (HGF) is a chemoattractant and inducer for neural stem/progenitor (NS/P) cell migration. Although the type II transmembrane serine protease, matriptase (MTP) is an activator of the latent HGF, MTP is indispensable on NS/P cell motility induced by the active form of HGF. This suggests that MTP's action on NS/P cell motility involves mechanisms other than proteolytic activation of HGF. In the present study, we investigate the role of MTP in HGF-stimulated signaling events. Using specific inhibitors of phosphatidylinositol-3-kinase (PI3K), protein kinase B (Akt) or focal adhesion kinase (FAK), we demonstrated that in NS/P cells HGF-activated c-Met induces PI3k-Akt signaling which then leads to FAK activation. This signaling pathway ultimately induces MMP2 expression and NS/P cell motility. Knocking down of MTP in NS/P cells with specific siRNA impaired HGF-stimulation of c-Met, Akt and FAK activation, blocked HGF-induced production of MMP2 and inhibited HGF-stimulated NS/P cell motility. MTP-knockdown NS/P cells cultured in the presence of recombinant protein of MTP protease domain or transfected with the full-length wild-type but not the protease-defected MTP restored HGF-responsive events in NS/P cells. In addition to functioning as HGF activator, our data revealed novel function of MTP on HGF-stimulated c-Met signaling activation. Copyright © 2014. Published by Elsevier B.V.

  11. Light-induced antibacterial activity of electrospun chitosan-based material containing photosensitizer

    Energy Technology Data Exchange (ETDEWEB)

    Severyukhina, A.N., E-mail: severyuhina_alexandra@mail.ru [Institute of Nanostructures and Biosystems, Saratov State University, 410012 Saratov (Russian Federation); Petrova, N.V.; Yashchenok, A.M. [Institute of Nanostructures and Biosystems, Saratov State University, 410012 Saratov (Russian Federation); Bratashov, D.N. [Institute of Nanostructures and Biosystems, Saratov State University, 410012 Saratov (Russian Federation); Department of Nano- and Biomedical Technologies, Saratov State University, 410012 Saratov (Russian Federation); Smuda, K. [Institute of Transfusion Medicine, Charité-Universitätsmedizin, 10117 Berlin (Germany); Mamonova, I.A. [Institute of Traumatology and Orthopedics, 410002 Saratov (Russian Federation); Yurasov, N.A. [Institute of Nanostructures and Biosystems, Saratov State University, 410012 Saratov (Russian Federation); Puchinyan, D.M. [Institute of Nanostructures and Biosystems, Saratov State University, 410012 Saratov (Russian Federation); Institute of Traumatology and Orthopedics, 410002 Saratov (Russian Federation); Georgieva, R. [Institute of Transfusion Medicine, Charité-Universitätsmedizin, 10117 Berlin (Germany); Department of Medical Physics, Biophysics and Radiology, Medical Faculty, Trakia University, 6000 Stara Zagora (Bulgaria); Bäumler, H. [Institute of Transfusion Medicine, Charité-Universitätsmedizin, 10117 Berlin (Germany); Lapanje, A. [Institute of Nanostructures and Biosystems, Saratov State University, 410012 Saratov (Russian Federation); Josef Stefan Institute, 1000 Ljubljana (Slovenia); Gorin, D.A. [Institute of Nanostructures and Biosystems, Saratov State University, 410012 Saratov (Russian Federation); Department of Nano- and Biomedical Technologies, Saratov State University, 410012 Saratov (Russian Federation)

    2017-01-01

    Increasing antimicrobial resistance requires the development of novel materials and approaches for treatment of various infections. Utilization of photodynamic therapy represents an advanced alternative to antibiotics and metal-based agents. Here, we report the fabrication of electrospun material that possesses benefits of both topical antimicrobial and photodynamic therapies. This material combines chitosan, as a biocompatible polymer, and a second generation photosensitizer. The incorporation of photosensitizer doesn't affect the material morphology and its nearly uniform distribution in fibers structure was observed by confocal Raman microscopy. Owing to photosensitizer the prepared material exhibits the light-induced and spatially limited antimicrobial activity that was demonstrated against Staphylococcus aureus, an important etiological infectious agent. Such material can be potentially used in antibacterial therapy of chronic wounds, infections of diabetic ulcers, and burns, as well as rapidly spreading and intractable soft-tissue infections caused by resistant bacteria. - Highlights: • Chitosan with a phthalocyanine photosensitizer was electrospun into fibers. • Photosensitizer was uniformly distributed in the electrospun material. • The incorporation of photosensitizer does not affect the fiber morphology. • Chitosan/photosensitizer composites possess light-induced antibacterial activity. • The antibacterial activity of the material is limited to the area of irradiation.

  12. ERK1/2 signaling plays an important role in topoisomerase II poison-induced G2/M checkpoint activation.

    Science.gov (United States)

    Kolb, Ryan H; Greer, Patrick M; Cao, Phu T; Cowan, Kenneth H; Yan, Ying

    2012-01-01

    Topo II poisons, which target topoisomerase II (topo II) to generate enzyme mediated DNA damage, have been commonly used for anti-cancer treatment. While clinical evidence demonstrate a capability of topo II poisons in inducing apoptosis in cancer cells, accumulating evidence also show that topo II poison treatment frequently results in cell cycle arrest in cancer cells, which was associated with subsequent resistance to these treatments. Results in this report indicate that treatment of MCF-7 and T47D breast cancer cells with topo II poisons resulted in an increased phosphorylation of extracellular signal-regulated kinase 1 and 2 (ERK1/2) and an subsequent induction of G2/M cell cycle arrest. Furthermore, inhibition of ERK1/2 activation using specific inhibitors markedly attenuated the topo II poison-induced G2/M arrest and diminished the topo II poison-induced activation of ATR and Chk1 kinases. Moreover, decreased expression of ATR by specific shRNA diminished topo II poison-induced G2/M arrest but had no effect on topo II poison-induced ERK1/2 activation. In contrast, inhibition of ERK1/2 signaling had little, if any, effect on topo II poison-induced ATM activation. In addition, ATM inhibition by either incubation of cells with ATM specific inhibitor or transfection of cells with ATM specific siRNA did not block topo II poison-induced G2/M arrest. Ultimately, inhibition of ERK1/2 signaling greatly enhanced topo II poison-induced apoptosis. These results implicate a critical role for ERK1/2 signaling in the activation of G2/M checkpoint response following topo II poison treatment, which protects cells from topo II poison-induced apoptosis.

  13. Transition polarizability model of induced resonance Raman optical activity

    Czech Academy of Sciences Publication Activity Database

    Yamamoto, S.; Bouř, Petr

    2013-01-01

    Roč. 34, č. 25 (2013), s. 2152-2158 ISSN 0192-8651 R&D Projects: GA ČR GAP208/11/0105; GA ČR GA13-03978S; GA MŠk(CZ) LH11033 Grant - others:AV ČR(CZ) M200551205 Institutional support: RVO:61388963 Keywords : induced resonance Raman optical activity * europium complexes * density functional computations * light scattering Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.601, year: 2013

  14. Attenuation of everolimus-induced cytotoxicity by a protective autophagic pathway involving ERK activation in renal cell carcinoma cells

    Science.gov (United States)

    Zeng, Yizhou; Tian, Xiaofang; Wang, Quan; He, Weiyang; Fan, Jing; Gou, Xin

    2018-01-01

    Aim The mammalian target of rapamycin (mTOR) pathway is a critical target for cancer treatment and the mTOR inhibitor everolimus (RAD001) has been approved for treatment of renal cell carcinoma (RCC). However, the limited efficacy of RAD001 has led to the development of drug resistance. Autophagy is closely related to cell survival and death, which may be activated under RAD001 stimulation. The aim of the present study was to identify the underlying mechanisms of RAD001 resistance in RCC cells through cytoprotective autophagy involving activation of the extracellular signal-regulated kinase (ERK) pathway. Methods and results: RAD001 strongly induced autophagy of RCC cells in a dose- and time-dependent manner, as confirmed by Western blot analysis. Importantly, suppression of autophagy by the pharmacological inhibitor chloroquine effectively enhanced RAD001-induced apoptotic cytotoxicity, as demonstrated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and Western blot analysis, indicating a cytoprotective role for RAD001-induced autophagy. In addition, as was shown by the MTT assay, flow cytometry, and Western blot analysis, RAD001 robustly activated ERK, but not c-Jun N-terminal kinase and p38. Activation of ERK was inhibited by the pharmacological inhibitor selumetinib (AZD6244), which effectively promoted RAD001-induced cell death. Moreover, employing AZD6244 markedly attenuated RAD001-induced autophagy and enhanced RAD001-induced apoptosis, which play a central role in RAD001-induced cell death. Furthermore, RAD001-induced autophagy is regulated by ERK-mediated phosphorylation of Beclin-1 and B-cell lymphoma 2, as confirmed by Western blot analysis. Conclusion These results suggest that RAD001-induced autophagy involves activation of the ERK, which may impair cytotoxicity of RAD001 in RCC cells. Thus, inhibition of the activation of ERK pathway-mediated autophagy may be useful to overcome chemoresistance to RAD001. PMID:29719377

  15. Activity-induced clustering in model dumbbell swimmers: the role of hydrodynamic interactions.

    Science.gov (United States)

    Furukawa, Akira; Marenduzzo, Davide; Cates, Michael E

    2014-08-01

    Using a fluid-particle dynamics approach, we numerically study the effects of hydrodynamic interactions on the collective dynamics of active suspensions within a simple model for bacterial motility: each microorganism is modeled as a stroke-averaged dumbbell swimmer with prescribed dipolar force pairs. Using both simulations and qualitative arguments, we show that, when the separation between swimmers is comparable to their size, the swimmers' motions are strongly affected by activity-induced hydrodynamic forces. To further understand these effects, we investigate semidilute suspensions of swimmers in the presence of thermal fluctuations. A direct comparison between simulations with and without hydrodynamic interactions shows these to enhance the dynamic clustering at a relatively small volume fraction; with our chosen model the key ingredient for this clustering behavior is hydrodynamic trapping of one swimmer by another, induced by the active forces. Furthermore, the density dependence of the motility (of both the translational and rotational motions) exhibits distinctly different behaviors with and without hydrodynamic interactions; we argue that this is linked to the clustering tendency. Our study illustrates the fact that hydrodynamic interactions not only affect kinetic pathways in active suspensions, but also cause major changes in their steady state properties.

  16. Anti-ghrelin Spiegelmer inhibits exogenous ghrelin-induced increases in food intake, hoarding, and neural activation, but not food deprivation-induced increases

    Science.gov (United States)

    Teubner, Brett J. W.

    2013-01-01

    Circulating concentrations of the stomach-derived “hunger-peptide” ghrelin increase in direct proportion to the time since the last meal. Exogenous ghrelin also increases food intake in rodents and humans, suggesting ghrelin may increase post-fast ingestive behaviors. Food intake after food deprivation is increased by laboratory rats and mice, but not by humans (despite dogma to the contrary) or by Siberian hamsters; instead, humans and Siberian hamsters increase food hoarding, suggesting the latter as a model of fasting-induced changes in human ingestive behavior. Exogenous ghrelin markedly increases food hoarding by ad libitum-fed Siberian hamsters similarly to that after food deprivation, indicating sufficiency. Here, we tested the necessity of ghrelin to increase food foraging, food hoarding, and food intake, and neural activation [c-Fos immunoreactivity (c-Fos-ir)] using anti-ghrelin Spiegelmer NOX-B11–2 (SPM), an l-oligonucleotide that specifically binds active ghrelin, inhibiting peptide-receptor interaction. SPM blocked exogenous ghrelin-induced increases in food hoarding the first 2 days after injection, and foraging and food intake at 1–2 h and 2–4 h, respectively, and inhibited hypothalamic c-Fos-ir. SPM given every 24 h across 48-h food deprivation inconsistently inhibited food hoarding after refeeding and c-Fos-ir, similarly to inabilities to do so in laboratory rats and mice. These results suggest that ghrelin may not be necessary for food deprivation-induced foraging and hoarding and neural activation. A possible compensatory response, however, may underlie these findings because SPM treatment led to marked increases in circulating ghrelin concentrations. Collectively, these results show that SPM can block exogenous ghrelin-induced ingestive behaviors, but the necessity of ghrelin for food deprivation-induced ingestive behaviors remains unclear. PMID:23804279

  17. Axin1 up-regulated 1 accelerates stress-induced cardiomyocytes apoptosis through activating Wnt/β-catenin signaling.

    Science.gov (United States)

    Ye, Xing; Lin, Junyi; Lin, Zebin; Xue, Aimin; Li, Liliang; Zhao, Ziqin; Liu, Li; Shen, Yiwen; Cong, Bin

    2017-10-15

    Stress-induced cardiomyocyte apoptosis contributes to the pathogenesis of a variety of cardiovascular diseases, but how stress induces cardiomyocyte apoptosis remains largely unclear. The present study aims to investigate the effects of Axin1 up-regulated 1 (Axud1), a novel pro-apoptotic protein, on the cardiomyocyte survival and the underlying mechanisms. To this end, a rat model under restraint stress (RS) was established and in vitro stress-induced cardiomyocytes culture was achieved. Our data showed that Axud1 was upregulated in the rat myocardia after exposure to RS. Anti-apoptotic Bcl-2 was decreased, whereas pro-apoptotic Bax and Cleaved caspase-3 (Cc3) were increased in a time-dependent manner. The Wnt/β-catenin signaling was observed to be interestingly activated in heart undergoing RS. In addition, the treatment of norepinephrine (NE) to in vitro cardiomyocytes increased Axud1 level and induced cell apoptosis. Wnt/β-catenin signaling was consistently activated. Knockdown of Axud1 using specific siRNA blunted NE-induced cardiomyocytes apoptosis and also inactivated the Wnt/β-catenin signaling. XAV-939, an inhibitor of Wnt/β-catenin signaling, partially reversed the pro-apoptotic effect of NE. In conclusion, Axud1 accelerated stress-induced cardiomyocytes apoptosis through activation of Wnt/β-catenin signaling pathway. Our data provided novel evidence that therapeutic strategies against Axud1 or Wnt/β-catenin signaling might be promising in relation to RS-induced myocardial injury. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  18. Inhibitory mechanism of chroman compound on LPS-induced nitric oxide production and nuclear factor-κB activation

    International Nuclear Information System (INIS)

    Kim, Byung Hak; Reddy, Alavala Matta; Lee, Kum-Ho; Chung, Eun Yong; Cho, Sung Min; Lee, Heesoon; Min, Kyung Rak; Kim, Youngsoo

    2004-01-01

    6-Hydroxy-7-methoxychroman-2-carboxylic acid phenylamide (KL-1156) is a novel chemically synthetic compound. In the present study, the chroman KL-1156 compound was found to inhibit lipopolysaccharide (LPS)-induced nitric oxide production in macrophages RAW 264.7. KL-1156 compound attenuated LPS-induced synthesis of both mRNA and protein of inducible nitric oxide synthase (iNOS), in parallel, and inhibited LPS-induced iNOS promoter activity, indicating that the chroman compound down-regulated iNOS expression at transcription level. As a mechanism of the anti-inflammatory action shown by KL-1156 compound, suppression of nuclear factor (NF)-κB has been documented. KL-1156 compound exhibited a dose-dependent inhibitory effect on LPS-induced NF-κB transcriptional activity in macrophages RAW 264.7. Furthermore, the compound inhibited LPS-induced nuclear translocation of NF-κB p65 and DNA binding activity of NF-κB complex, in parallel, but did not affect IκBα degradation. Taken together, this study demonstrated that chroman KL-1156 compound interfered with nuclear translocation step of NF-κB p65, which was attributable to its anti-inflammatory action

  19. Resveratrol-Induced AMP-Activated Protein Kinase Activation Is Cell-Type Dependent: Lessons from Basic Research for Clinical Application.

    Science.gov (United States)

    Lan, Fan; Weikel, Karen A; Cacicedo, Jose M; Ido, Yasuo

    2017-07-14

    Despite the promising effects of resveratrol, its efficacy in the clinic remains controversial. We were the first group to report that the SIRT1 activator resveratrol activates AMP-activated protein kinase (AMPK) (Diabetes 2005; 54: A383), and we think that the variability of this cascade may be responsible for the inconsistency of resveratrol's effects. Our current studies suggest that the effect of SIRT1 activators such as resveratrol may not be solely through activation of SIRT1, but also through an integrated effect of SIRT1-liver kinase B1 (LKB1)-AMPK. In this context, resveratrol activates SIRT1 (1) by directly binding to SIRT1; and (2) by increasing NAD⁺ levels by upregulating the salvage pathway through Nampt activation, an effect mediated by AMPK. The first mechanism promotes deacetylation of a limited number of SIRT1 substrate proteins (e.g., PGC-1). The second mechanism (which may be more important than the first) activates other sirtuins in addition to SIRT1, which affects a broad spectrum of substrates. Despite these findings, detailed mechanisms of how resveratrol activates AMPK have not been reported. Here, we show that (1) resveratrol-induced activation of AMPK requires the presence of functional LKB1; (2) Resveratrol increases LKB1 activity, which involves translocation and phosphorylation at T336 and S428; (3) Activation of LKB1 causes proteasomal degradation of LKB1; (4) At high concentrations (50-100 µM), resveratrol also activates AMPK through increasing AMP levels; and (5) The above-mentioned activation mechanisms vary among cell types, and in some cell types, resveratrol fails to activate AMPK. These results suggest that resveratrol-induced activation of AMPK is not a ubiquitous phenomenon. In addition, AMPK-mediated increases in NAD⁺ in the second mechanism require several ATPs, which may not be available in many pathological conditions. These phenomena may explain why resveratrol is not always consistently beneficial in a clinical

  20. Effects of 6-methyl-uracil upon the phagocytic activity in mice following whole-body X-irradiation or 2,4,6,-triethyleneimino-s-triazine treatment

    International Nuclear Information System (INIS)

    Raake, W.; Tempel, K.

    1977-01-01

    1. Phagocytic activity measured by means of the intravasal clearence of a soot dispersion in male NMRI-mice was increased six to ten days after whole-body X-irradiation (640 R) and decreased during the same period after i.v. administration of 2,4,6-triethyleneimino-s-triazine (TEM 2.0 mg/kg). 2. By means of 6-methyl-uracil food admixtures (200 to 400 ppm during 2 or 3 weeks) or by repeated intravenous injections of a N-methyl-D-glucosamine-6-methyluracil complex (62.5 to 250 mg/kg daily during five days), a significant augmentation of the phagocytic index being related to time and dosage was obtained in otherwise untreated mice. Comparable results were seen using cytidine and cytidine-5'-phosphate, whereas guanosine-5'-phosphate remained ineffective. 3. Whilst stimulating effects of 6-methyl-uracil or its N-methyl-D-glucosamine complex on X-irradiated mice were suspended, an increase up to supernormal values of the phagocytic index was produced by the pyrimidine base in animals treated with TEM. In accordance to this the survival rate of lethally X-irradiated mice (960 R) could not be increased; with animals given lethal TEM-doses, however, a significantly increased survival rate was obtained. 4. The present investigations as well as former biochemical analyses confirm the assumption that 6-methyluracil produces its regeneration effects, to some extent at least, by specific pathways influencing the reticuloendothelium. Different results from X-irradiated and TEM-treated mice are referring to the different points of attack of the two noxa. (orig.) [de

  1. Activation of cAMP-dependent signaling pathway induces mouse organic anion transporting polypeptide 2 expression.

    Science.gov (United States)

    Chen, Chuan; Cheng, Xingguo; Dieter, Matthew Z; Tanaka, Yuji; Klaassen, Curtis D

    2007-04-01

    Rodent Oatp2 is a hepatic uptake transporter for such compounds as cardiac glycosides. In the present study, we found that fasting resulted in a 2-fold induction of Oatp2 expression in liver of mice. Because the cAMP-protein kinase A (PKA) signaling pathway is activated during fasting, the role of this pathway in Oatp2 induction during fasting was examined. In Hepa-1c1c7 cells, adenylyl cyclase activator forskolin as well as two cellular membrane-permeable cAMP analogs, dibutyryl cAMP and 8-bromo-cAMP, induced Oatp2 mRNA expression in a time- and dose-dependent manner. These three chemicals induced reporter gene activity in cells transfected with a luciferase reporter gene construct containing a 7.6-kilobase (kb) 5'-flanking region of mouse Oatp2. Transient transfection of cells with 5'-deletion constructs derived from the 7.6-kb Oatp2 promoter reporter gene construct, as well as 7.6-kb constructs in which a consensus cAMP response element (CRE) half-site CGTCA (-1808/-1804 bp) was mutated or deleted, confirms that this CRE site was required for the induction of luciferase activity by forskolin. Luciferase activity driven by the Oatp2 promoter containing this CRE site was induced in cells cotransfected with a plasmid encoding the protein kinase A catalytic subunit. Cotransfection of cells with a plasmid encoding the dominant-negative CRE binding protein (CREB) completely abolished the inducibility of the reporter gene activity by forskolin. In conclusion, induction of Oatp2 expression in liver of fasted mice may be caused by activation of the cAMP-dependent signaling pathway, with the CRE site (-1808/-1804) and CREB being the cis- and trans-acting factors mediating the induction, respectively.

  2. Local field potentials in the ventral tegmental area during cocaine-induced locomotor activation: Measurements in freely moving rats.

    Science.gov (United States)

    Harris Bozer, Amber L; Li, Ai-Ling; Sibi, Jiny E; Bobzean, Samara A M; Peng, Yuan B; Perrotti, Linda I

    2016-03-01

    The ventral tegmental area (VTA) has been established as a critical nucleus for processing behavioral changes that occur during psychostimulant use. Although it is known that cocaine induced locomotor activity is initiated in the VTA, not much is known about the electrical activity in real time. The use of our custom-designed wireless module for recording local field potential (LFP) activity provides an opportunity to confirm and identify changes in neuronal activity within the VTA of freely moving rats. The purpose of this study was to investigate the changes in VTA LFP activity in real time that underlie cocaine induced changes in locomotor behavior. Recording electrodes were implanted in the VTA of rats. Locomotor behavior and LFP activity were simultaneously recorded at baseline, and after saline and cocaine injections. Results indicate that cocaine treatment caused increases in both locomotor behavior and LFP activity in the VTA. Specifically, LFP activity was highest during the first 30 min following the cocaine injection and was most robust in Delta and Theta frequency bands; indicating the role of low frequency VTA activity in the initiation of acute stimulant-induced locomotor behavior. Our results suggest that LFP recording in freely moving animals can be used in the future to provide valuable information pertaining to drug induced changes in neural activity. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. PGC-1α-Dependent Mitochondrial Adaptation Is Necessary to Sustain IL-2-Induced Activities in Human NK Cells.

    Science.gov (United States)

    Miranda, Dante; Jara, Claudia; Ibañez, Jorge; Ahumada, Viviana; Acuña-Castillo, Claudio; Martin, Adrian; Córdova, Alexandra; Montoya, Margarita

    2016-01-01

    Human Natural Killer (NK) cells are a specialized heterogeneous subpopulation of lymphocytes involved in antitumor defense reactions. NK cell effector functions are critically dependent on cytokines and metabolic activity. Among various cytokines modulating NK cell function, interleukin-2 (IL-2) can induce a more potent cytotoxic activity defined as lymphokine activated killer activity (LAK). Our aim was to determine if IL-2 induces changes at the mitochondrial level in NK cells to support the bioenergetic demand for performing this enhanced cytotoxic activity more efficiently. Purified human NK cells were cultured with high IL-2 concentrations to develop LAK activity, which was assessed by the ability of NK cells to lyse NK-resistant Daudi cells. Here we show that, after 72 h of culture of purified human NK cells with enough IL-2 to induce LAK activity, both the mitochondrial mass and the mitochondrial membrane potential increased in a PGC-1α-dependent manner. In addition, oligomycin, an inhibitor of ATP synthase, inhibited IL-2-induced LAK activity at 48 and 72 h of culture. Moreover, the secretion of IFN-γ from NK cells with LAK activity was also partially dependent on PGC-1α expression. These results indicate that PGC-1α plays a crucial role in regulating mitochondrial function involved in the maintenance of LAK activity in human NK cells stimulated with IL-2.

  4. Selective activation of human heat shock gene transcription by nitrosourea antitumor drugs mediated by isocyanate-induced damage and activation of heat shock transcription factor.

    Science.gov (United States)

    Kroes, R A; Abravaya, K; Seidenfeld, J; Morimoto, R I

    1991-01-01

    Treatment of cultured human tumor cells with the chloroethylnitrosourea antitumor drug 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) selectively induces transcription and protein synthesis of a subset of the human heat shock or stress-induced genes (HSP90 and HSP70) with little effect on other stress genes or on expression of the c-fos, c-myc, or beta-actin genes. The active component of BCNU and related compounds appears to be the isocyanate moiety that causes carbamoylation of proteins and nucleic acids. Transcriptional activation of the human HSP70 gene by BCNU is dependent on the heat shock element and correlates with the level of heat shock transcription factor and its binding to the heat shock element in vivo. Unlike activation by heat or heavy metals, BCNU-mediated activation is strongly dependent upon new protein synthesis. This suggests that BCNU-induced, isocyanate-mediated damage to newly synthesized protein(s) may be responsible for activation of the heat shock transcription factor and increased transcription of the HSP90 and HSP70 genes. Images PMID:2052560

  5. Aryl Hydrocarbon Receptor (AhR Modulates Cockroach Allergen-Induced Immune Responses through Active TGFβ1 Release

    Directory of Open Access Journals (Sweden)

    Yufeng Zhou

    2014-01-01

    Full Text Available Background. Aryl hydrocarbon receptor (AhR, a multifunctional regulator that senses and responds to environmental stimuli, plays a role in normal cell development and immune regulation. Recent evidence supports a significant link between environmental exposure and AhR in the development of allergic diseases. We sought to investigate whether AhR plays a role in mediating cockroach allergen-induced allergic immune responses. Methods. AhR expression in human lung fibroblasts from asthmatic and healthy individuals and in cockroach extract (CRE treated human lung fibroblasts (WI-38 was examined. The role of AhR in modulating CRE induced TGFβ1 production was investigated by using AhR agonist, TCDD, antagonist CH122319, and knockdown of AhR. The role of latent TGFβ1 binding protein-1 (LTBP1 in mediating TCDD induced active TGFβ1 release was also examined. Results. AhR expression was higher in airway fibroblasts from asthmatic subjects as compared to healthy controls. AhR in fibroblasts was activated by TCDD with an increased expression of cyp1a1 and cyp1b1. Increased AhR expression was observed in CRE-treated fibroblasts. Importantly, CRE induced TGFβ1 production in fibroblasts was significantly enhanced by TCDD but inhibited by CH122319. Reduced TGFβ1 production was further confirmed in fibroblasts with AhR knockdown. Moreover, AhR knockdown inhibited CRE induced fibroblast differentiation. Furthermore, TCDD induced active TGFβ1 release was significantly inhibited by LTBP1 knockdown. Conclusion. These results provide evidence for the role of AhR in modulating cockroach allergen-induced immune responses through controlling the active TGFβ1 release, suggesting a possible synergistic effect between exposure to allergens and environmental chemicals on the development of allergic diseases.

  6. Leishmania donovani isolates with antimony-resistant but not -sensitive phenotype inhibit sodium antimony gluconate-induced dendritic cell activation.

    Directory of Open Access Journals (Sweden)

    Arun Kumar Haldar

    2010-05-01

    Full Text Available The inability of sodium antimony gluconate (SAG-unresponsive kala-azar patients to clear Leishmania donovani (LD infection despite SAG therapy is partly due to an ill-defined immune-dysfunction. Since dendritic cells (DCs typically initiate anti-leishmanial immunity, a role for DCs in aberrant LD clearance was investigated. Accordingly, regulation of SAG-induced activation of murine DCs following infection with LD isolates exhibiting two distinct phenotypes such as antimony-resistant (Sb(RLD and antimony-sensitive (Sb(SLD was compared in vitro. Unlike Sb(SLD, infection of DCs with Sb(RLD induced more IL-10 production and inhibited SAG-induced secretion of proinflammatory cytokines, up-regulation of co-stimulatory molecules and leishmanicidal effects. Sb(RLD inhibited these effects of SAG by blocking activation of PI3K/AKT and NF-kappaB pathways. In contrast, Sb(SLD failed to block activation of SAG (20 microg/ml-induced PI3K/AKT pathway; which continued to stimulate NF-kappaB signaling, induce leishmanicidal effects and promote DC activation. Notably, prolonged incubation of DCs with Sb(SLD also inhibited SAG (20 microg/ml-induced activation of PI3K/AKT and NF-kappaB pathways and leishmanicidal effects, which was restored by increasing the dose of SAG to 40 microg/ml. In contrast, Sb(RLD inhibited these SAG-induced events regardless of duration of DC exposure to Sb(RLD or dose of SAG. Interestingly, the inhibitory effects of isogenic Sb(SLD expressing ATP-binding cassette (ABC transporter MRPA on SAG-induced leishmanicidal effects mimicked that of Sb(RLD to some extent, although antimony resistance in clinical LD isolates is known to be multifactorial. Furthermore, NF-kappaB was found to transcriptionally regulate expression of murine gammaglutamylcysteine synthetase heavy-chain (mgammaGCS(hc gene, presumably an important regulator of antimony resistance. Importantly, Sb(RLD but not Sb(SLD blocked SAG-induced mgammaGCS expression in DCs by

  7. Phagolysosome acidification is required for silica and engineered nanoparticle-induced lysosome membrane permeabilization and resultant NLRP3 inflammasome activity

    Energy Technology Data Exchange (ETDEWEB)

    Jessop, Forrest; Hamilton, Raymond F.; Rhoderick, Joseph F.; Fletcher, Paige; Holian, Andrij, E-mail: andrij.holian@umontana.edu

    2017-03-01

    NLRP3 inflammasome activation occurs in response to hazardous particle exposures and is critical for the development of particle-induced lung disease. Mechanisms of Lysosome Membrane Permeabilization (LMP), a central pathway for activation of the NLRP3 inflammasome by inhaled particles, are not fully understood. We demonstrate that the lysosomal vATPases inhibitor Bafilomycin A1 blocked LMP in vitro and ex vivo in primary murine macrophages following exposure to silica, multi-walled carbon nanotubes, and titanium nanobelts. Bafilomycin A1 treatment of particle-exposed macrophages also resulted in decreased active cathepsin L in the cytosol, a surrogate measure for leaked cathepsin B, which was associated with less NLRP3 inflammasome activity. Silica-induced LMP was partially dependent upon lysosomal cathepsins B and L, whereas nanoparticle-induced LMP occurred independent of cathepsin activity. Furthermore, inhibition of lysosomal cathepsin activity with CA-074-Me decreased the release of High Mobility Group Box 1. Together, these data support the notion that lysosome acidification is a prerequisite for particle-induced LMP, and the resultant leak of lysosome cathepsins is a primary regulator of ongoing NLRP3 inflammasome activity and release of HMGB1. - Highlights: • Silica and nanoparticles cause LMP in macrophages in vitro and in vivo. • Phagolysosome acidification is required for particle-induced LMP. • Cathepsin B and L are not required for nanoparticle-induced LMP. • Cathepsin B/L regulate the secretion of HMGB1 with particle exposure.

  8. Phagolysosome acidification is required for silica and engineered nanoparticle-induced lysosome membrane permeabilization and resultant NLRP3 inflammasome activity

    International Nuclear Information System (INIS)

    Jessop, Forrest; Hamilton, Raymond F.; Rhoderick, Joseph F.; Fletcher, Paige; Holian, Andrij

    2017-01-01

    NLRP3 inflammasome activation occurs in response to hazardous particle exposures and is critical for the development of particle-induced lung disease. Mechanisms of Lysosome Membrane Permeabilization (LMP), a central pathway for activation of the NLRP3 inflammasome by inhaled particles, are not fully understood. We demonstrate that the lysosomal vATPases inhibitor Bafilomycin A1 blocked LMP in vitro and ex vivo in primary murine macrophages following exposure to silica, multi-walled carbon nanotubes, and titanium nanobelts. Bafilomycin A1 treatment of particle-exposed macrophages also resulted in decreased active cathepsin L in the cytosol, a surrogate measure for leaked cathepsin B, which was associated with less NLRP3 inflammasome activity. Silica-induced LMP was partially dependent upon lysosomal cathepsins B and L, whereas nanoparticle-induced LMP occurred independent of cathepsin activity. Furthermore, inhibition of lysosomal cathepsin activity with CA-074-Me decreased the release of High Mobility Group Box 1. Together, these data support the notion that lysosome acidification is a prerequisite for particle-induced LMP, and the resultant leak of lysosome cathepsins is a primary regulator of ongoing NLRP3 inflammasome activity and release of HMGB1. - Highlights: • Silica and nanoparticles cause LMP in macrophages in vitro and in vivo. • Phagolysosome acidification is required for particle-induced LMP. • Cathepsin B and L are not required for nanoparticle-induced LMP. • Cathepsin B/L regulate the secretion of HMGB1 with particle exposure.

  9. Paraoxon induces apoptosis in EL4 cells via activation of mitochondrial pathways.

    Science.gov (United States)

    Saleh, A M; Vijayasarathy, C; Masoud, L; Kumar, L; Shahin, A; Kambal, A

    2003-07-01

    The toxicity of organophosphorus compounds, such as paraoxon (POX), is due to their anticholinesterase action. Recently, we have shown that, at noncholinergic doses (1 to 10 nM), POX (the bioactive metabolite of parathion) causes apoptotic cell death in murine EL4 T-lymphocytic leukemia cell line through activation of caspase-3. In this study, by employing caspase-specific inhibitors, we extend our observations to elucidate the sequence of events involved in POX-stimulated apoptosis. Pretreatment of EL4 cells with the caspase-9-specific inhibitor zLEHD-fmk attenuated POX-induced apoptosis in a dose-dependent manner, whereas the caspase-8 inhibitor zIETD-fmk had no effect. Furthermore, the activation of caspase-9, -8, and -3 in response to POX treatment was completely inhibited in the presence of zLEHD-fmk, implicating the involvement of caspase 9-dependent mitochondrial pathways in POX-stimulated apoptosis. Indeed, under both in vitro and in vivo conditions, POX triggered a dose- and time-dependent translocation of cytochrome c from mitochondria into the cytosol, as assessed by Western blot analysis. Investigation of the mechanism of cytochrome c release revealed that POX disrupted mitochondrial transmembrane potential. Neither this effect nor cytchrome c release was dependent on caspase activation, since the general inhibitor of the caspase family zVAD-fmk did not influence both processes. Finally, POX treatment also resulted in a time-dependent up-regulation and translocation of the proapoptotic molecule Bax to mitochondria. Inhibition of this event by zVAD-fmk suggests that the activation and translocation of Bax to mitochondria is subsequent to activation of the caspase cascades. The results indicate that POX induces apoptosis in EL4 cells through a direct effect on mitochondria by disrupting its transmembrane potential, causing the release of cytochrome c into the cytosol and subsequent activation of caspase-9. Inhibition of this specific pathway might provide

  10. Curcumin induces cleavage of β-catenin by activation of capases ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-19

    Oct 19, 2009 ... When the Wnt pathway is activated, GSK3β is inhibited and β-catenin is not phos- phorylated any more and the level of cellular β-catenin increases. Free β-catenin can translocate to the nucleus, forming a complex with T-cell factor 4 (Tcf-4). This com- plex then binds DNA and induces the expression of.

  11. Platelet activating factor-induced ceramide micro-domains drive endothelial NOS activation and contribute to barrier dysfunction.

    Directory of Open Access Journals (Sweden)

    Sanda Predescu

    Full Text Available The spatial and functional relationship between platelet activating factor-receptor (PAF-R and nitric oxide synthase (eNOS in the lateral plane of the endothelial plasma membrane is poorly characterized. In this study, we used intact mouse pulmonary endothelial cells (ECs as well as endothelial plasma membrane patches and subcellular fractions to define a new microdomain of plasmalemma proper where the two proteins colocalize and to demonstrate how PAF-mediated nitric oxide (NO production fine-tunes ECs function as gatekeepers of vascular permeability. Using fluorescence microscopy and immunogold labeling electron microscopy (EM on membrane patches we demonstrate that PAF-R is organized as clusters and colocalizes with a subcellular pool of eNOS, outside recognizable vesicular profiles. Moreover, PAF-induced acid sphingomyelinase activation generates a ceramide-based microdomain on the external leaflet of plasma membrane, inside of which a signalosome containing eNOS shapes PAF-stimulated NO production. Real-time measurements of NO after PAF-R ligation indicated a rapid (5 to 15 min increase in NO production followed by a > 45 min period of reduction to basal levels. Moreover, at the level of this new microdomain, PAF induces a dynamic phosphorylation/dephosphorylation of Ser, Thr and Tyr residues of eNOS that correlates with NO production. Altogether, our findings establish the existence of a functional partnership PAF-R/eNOS on EC plasma membrane, at the level of PAF-induced ceramide plasma membrane microdomains, outside recognized vesicular profiles.

  12. Riboflavin-Induced Disease Resistance Requires the Mitogen-Activated Protein Kinases 3 and 6 in Arabidopsis thaliana.

    Science.gov (United States)

    Nie, Shengjun; Xu, Huilian

    2016-01-01

    As a resistance elicitor, riboflavin (vitamin B2) protects plants against a wide range of pathogens. At molecular biological levels, it is important to elucidate the signaling pathways underlying the disease resistance induced by riboflavin. Here, riboflavin was tested to induce resistance against virulent Pseudomonas syringae pv. Tomato DC3000 (Pst DC3000) in Arabidopsis. Results showed that riboflavin induced disease resistance based on MAPK-dependent priming for the expression of PR1 gene. Riboflavin induced transient expression of PR1 gene. However, following Pst DC3000 inoculation, riboflavin potentiated stronger PR1 gene transcription. Further was suggested that the transcript levels of mitogen-activated protein kinases, MPK3 and MPK6, were primed under riboflavin. Upon infection by Pst DC3000, these two enzymes were more strongly activated. The elevated activation of both MPK3 and MPK6 was responsible for enhanced defense gene expression and resistance after riboflavin treatment. Moreover, riboflavin significantly reduced the transcript levels of MPK3 and MPK6 by application of AsA and BAPTA, an H2O2 scavenger and a calcium (Ca2+) scavenger, respectively. In conclusion, MPK3 and MPK6 were responsible for riboflavin-induced resistance, and played an important role in H2O2- and Ca2+-related signaling pathways, and this study could provide a new insight into the mechanistic study of riboflavin-induced defense responses.

  13. Curcumin Regulates Low-Linear Energy Transfer γ-Radiation-Induced NFκB-Dependent Telomerase Activity in Human Neuroblastoma Cells

    International Nuclear Information System (INIS)

    Aravindan, Natarajan; Veeraraghavan, Jamunarani; Madhusoodhanan, Rakhesh; Herman, Terence S.; Natarajan, Mohan

    2011-01-01

    Purpose: We recently reported that curcumin attenuates ionizing radiation (IR)-induced survival signaling and proliferation in human neuroblastoma cells. Also, in the endothelial system, we have demonstrated that NFκB regulates IR-induced telomerase activity (TA). Accordingly, we investigated the effect of curcumin in inhibiting IR-induced NFκB-dependent hTERT transcription, TA, and cell survival in neuroblastoma cells. Methods and Materials: SK-N-MC or SH-SY5Y cells exposed to IR and treated with curcumin (10-100 nM) with or without IR were harvested after 1 h through 24 h. NFκB-dependent regulation was investigated either by luciferase reporter assays using pNFκB-, pGL3-354-, pGL3-347-, or pUSE-IκBα-Luc, p50/p65, or RelA siRNA-transfected cells. NFκB activity was analyzed using an electrophoretic mobility shift assay and hTERT expression using the quantitative polymerase chain reaction. TA was determined using the telomerase repeat amplification protocol assay and cell survival using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltertrazolium bromide and clonogenic assay. Results: Curcumin profoundly inhibited IR-induced NFκB. Consequently, curcumin significantly inhibited IR-induced TA and hTERT mRNA at all points investigated. Furthermore, IR-induced TA is regulated at the transcriptional level by triggering telomerase reverse transcriptase (TERT) promoter activation. Moreover, NFκB becomes functionally activated after IR and mediates TA upregulation by binding to the κB-binding region in the promoter region of the TERT gene. Consistently, elimination of the NFκB-recognition site on the telomerase promoter or inhibition of NFκB by the IκBα mutant compromises IR-induced telomerase promoter activation. Significantly, curcumin inhibited IR-induced TERT transcription. Consequently, curcumin inhibited hTERT mRNA and TA in NFκB overexpressed cells. Furthermore, curcumin enhanced the IR-induced inhibition of cell survival. Conclusions: These results

  14. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) induces Fas-dependent activation-induced cell death in superantigen-primed T cells

    Energy Technology Data Exchange (ETDEWEB)

    Camacho, Iris A; Nagarkatti, Mitzi [Department of Microbiology and Immunology, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA 23298 (United States); Nagarkatti, Prakash S [Department of Pharmacology and Toxicology, PO Box 980613, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA 23298-0613 (United States)

    2002-10-01

    Immune response against a foreign antigen is characterized by a growth phase, in which antigen-specific T cells clonally expand, followed by a decline phase in which the activated T cells undergo apoptosis, a process termed activation-induced cell death (AICD). In the current study, we have investigated the phase at which 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) acts to downregulate the antigen-specific T cell response. To this end, C57BL/6 +/+ mice were injected with staphylococcal enterotoxin A (SEA) into the footpads (10 {mu}g/footpad), and simultaneously treated with TCDD (10 or 50 {mu}g/kg intraperitoneally). At various time points, the draining lymph node (LN) cells were analyzed for SEA-activated T cells. The data demonstrated that in C57BL/6 +/+ mice, TCDD treatment did not alter the growth phase but facilitated the decline phase of SEA-reactive T cells. TCDD caused a significant decrease in the percentage and absolute numbers of CD4{sup +} and CD8{sup +} SEA-responsive T cells expressing V{beta}3{sup +} and V{beta}11{sup +} but did not affect SEA-nonresponsive V{beta}8{sup +} T cells. Upon in vitro culture, TCDD-exposed SEA-immunized LN cells exhibited increased levels of apoptosis when compared with the vehicle controls. When Fas-deficient (C57BL/6 lpr/lpr) or Fas ligand defective (C57BL/6 gld/gld) mice were treated with TCDD, they failed to exhibit a decrease in percentage and cellularity of SEA-reactive T cells, thereby suggesting a role of Fas-Fas ligand interactions in the TCDD-induced downregulation of SEA-reactive T cell response. The resistance to TCDD-induced decrease in T cell responsiveness to SEA seen in Fas- and FasL-mutant mice was neither due to decreased aryl hydrocabon receptor (AhR) expression nor to altered T cell responsiveness to SEA. The current study demonstrates that TCDD does not prevent T cell activation, but prematurely induces Fas-based AICD, which may contribute to the deletion of antigen-primed T cells. (orig.)

  15. Thymoquinone inhibits phorbol ester-induced activation of NF-κB and expression of COX-2, and induces expression of cytoprotective enzymes in mouse skin in vivo

    International Nuclear Information System (INIS)

    Kundu, Joydeb Kumar; Liu, Lijia; Shin, Jun-Wan; Surh, Young-Joon

    2013-01-01

    Highlights: •Thymoquinone inhibits phorbol ester-induced COX-2 expression in mouse skin. •Thymoquinone attenuates phosphorylation of IκBα and DNA binding of NF-κB in mouse skin. •Thymoquinone inhibits phosphorylation of p38 MAP kinase, JNK and Akt in mouse skin. •Thymoquinone induces the expression of cytoprotective proteins in mouse skin. -- Abstract: Thymoquinone (TQ), the active ingredient of Nigella sativa, has been reported to possess anti-inflammatory and chemopreventive properties. The present study was aimed at elucidating the molecular mechanisms of anti-inflammatory and antioxidative activities of thymoquinone in mouse skin. Pretreatment of female HR-1 hairless mouse skin with TQ attenuated 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced expression of cyclooxygenase-2 (COX-2). TQ diminished nuclear translocation and the DNA binding of nuclear factor-kappaB (NF-κB) via the blockade of phosphorylation and subsequent degradation of IκBα in TPA-treated mouse skin. Pretreatment with TQ attenuated the phosphorylation of Akt, c-Jun-N-terminal kinase and p38 mitogen-activated protein kinase, but not that of extracellular signal-regulated kinase-1/2. Moreover, topical application of TQ induced the expression of heme oxygenase-1, NAD(P)H-quinoneoxidoreductase-1, glutathione-S-transferase and glutamate cysteine ligase in mouse skin. Taken together, the inhibitory effects of TQ on TPA-induced COX-2 expression and NF-κB activation, and its ability to induce the expression of cytoprotective proteins provide a mechanistic basis of anti-inflammatory and antioxidative effects of TQ in hairless mouse skin

  16. Antisense oligonucleotides suppress cell-volume-induced activation of chloride channels.

    Science.gov (United States)

    Gschwentner, M; Nagl, U O; Wöll, E; Schmarda, A; Ritter, M; Paulmichl, M

    1995-08-01

    Cell volume regulation is an essential feature of most cells. After swelling in hypotonic media, the simultaneous activation of potassium and chloride channels is believed to be the initial, time-determining step in cell volume regulation. The activation of both pathways is functionally linked and enables the cells to lose ions and water, subsequently leading to cell shrinkage and readjustment of the initial volume. NIH 3T3 fibroblasts efficiently regulate their volume after swelling and bear chloride channels that are activated by decreasing extracellular osmolarity. The chloride current elicited in these cells after swelling is reminiscent of the current found in oocytes expressing an outwardly rectifying chloride current termed ICln. Introduction of antisense oligodeoxynucleotides complementary to the first 30 nucleotides of the coding region of the ICln channel into NIH 3T3 fibroblasts suppresses the activation of the swelling-induced chloride current. The experiments directly demonstrate an unambiguous link between a volume-activated chloride current and a cloned protein involved in chloride transport.

  17. Calculation of induced activity in the V-230 reactor

    International Nuclear Information System (INIS)

    Bouhahhane, A.; Farkas, G.

    2013-01-01

    In this paper, we focused on the calculation of the neutron induced activity of nuclear reactor components for decommissioning purposes. The results confirm, that the most important radionuclides in the reactor components dismantling process are 55 Fe (1 st decade), 60 Co (10 - 50 y) and 63 Ni (during the whole process). Another aim of this paper was to refer to the possibility to improve the accuracy of the calculations using continuous energy Monte Carlo methods. (authors)

  18. Pituitary Adenylate Cyclase-Activating Polypeptide Reverses Ammonium Metavanadate-Induced Airway Hyperresponsiveness in Rats

    Directory of Open Access Journals (Sweden)

    Mounira Tlili

    2015-01-01

    Full Text Available The rate of atmospheric vanadium is constantly increasing due to fossil fuel combustion. This environmental pollution favours vanadium exposure in particular to its vanadate form, causing occupational bronchial asthma and bronchitis. Based on the well admitted bronchodilator properties of the pituitary adenylate cyclase-activating polypeptide (PACAP, we investigated the ability of this neuropeptide to reverse the vanadate-induced airway hyperresponsiveness in rats. Exposure to ammonium metavanadate aerosols (5 mg/m3/h for 15 minutes induced 4 hours later an array of pathophysiological events, including increase of bronchial resistance and histological alterations, activation of proinflammatory alveolar macrophages, and increased oxidative stress status. Powerfully, PACAP inhalation (0.1 mM for 10 minutes alleviated many of these deleterious effects as demonstrated by a decrease of bronchial resistance and histological restoration. PACAP reduced the level of expression of mRNA encoding inflammatory chemokines (MIP-1α, MIP-2, and KC and cytokines (IL-1α and TNF-α in alveolar macrophages and improved the antioxidant status. PACAP reverses the vanadate-induced airway hyperresponsiveness not only through its bronchodilator activity but also by counteracting the proinflammatory and prooxidative effects of the metal. Then, the development of stable analogs of PACAP could represent a promising therapeutic alternative for the treatment of inflammatory respiratory disorders.

  19. Role of bioavailable iron in coal dust-induced activation of activator protein-1 and nuclear factor of activated T cells: difference between Pennsylvania and Utah coal dusts.

    Science.gov (United States)

    Huang, Chuanshu; Li, Jingxia; Zhang, Qi; Huang, Xi

    2002-11-01

    Activator protein-1 (AP-1) and nuclear factor of activated T cells (NFAT) are two important transcription factors responsible for the regulation of cytokines, which are involved in cell proliferation and inflammation. Coal workers' pneumoconiosis (CWP) is an occupational lung disease that may be related to chronic inflammation caused by coal dust exposure. In the present study, we demonstrate that coal from the Pennsylvania (PA) coalmine region, which has a high prevalence of CWP, can activate both AP-1 and NFAT in JB6 mouse epidermal cells. In contrast, coal from the Utah (UT) coalmine region, which has a low prevalence of CWP, has no such effects. The PA coal stimulates mitogen-activated protein kinase (MAPK) family members of extracellular signal-regulated kinases (ERKs) and p38 MAPK but not c-Jun-NH(2)-terminal kinases, as determined by the phosphorylation assay. The increase in AP-1 by the PA coal was completely eliminated by the pretreatment of cells with PD98059, a specific MAPK kinase inhibitor, and SB202190, a p38 kinase inhibitor, further confirming that the PA coal-induced AP-1 activation is mediated through ERKs and p38 MAPK pathways. Deferoxamine (DFO), an iron chelator, synergistically enhanced the PA coal-induced AP-1 activity, but inhibited NFAT activity. For comparison, cells were treated with ferrous sulfate and/or DFO. We have found that iron transactivated both AP-1 and NFAT, and DFO further enhanced iron-induced AP-1 activation but inhibited NFAT. These results indicate that activation of AP-1 and NFAT by the PA coal is through bioavailable iron present in the coal. These data are in agreement with our previous findings that the prevalence of CWP correlates well with levels of bioavailable iron in coals from various mining regions.

  20. The interplay between neuroendocrine activity and psychological stress-induced exacerbation of allergic asthma

    Directory of Open Access Journals (Sweden)

    Tomomitsu Miyasaka

    2018-01-01

    Full Text Available Psychological stress is recognized as a key factor in the exacerbation of allergic asthma, whereby brain responses to stress act as immunomodulators for asthma. In particular, stress-induced enhanced type 2 T-helper (Th2-type lung inflammation is strongly associated with asthma pathogenesis. Psychological stress leads to eosinophilic airway inflammation through activation of the hypothalamic-pituitary-adrenal pathway and autonomic nervous system. This is followed by the secretion of stress hormones into the blood, including glucocorticoids, epinephrine, and norepinephrine, which enhance Th2 and type 17 T-helper (Th17-type asthma profiles in humans and rodents. Recent evidence has shown that a defect of the μ-opioid receptor in the brain along with a defect of the peripheral glucocorticoid receptor signaling completely disrupted stress-induced airway inflammation in mice. This suggests that the stress response facilitates events in the central nervous and endocrine systems, thus exacerbating asthma. In this review, we outline the recent findings on the interplay between stress and neuroendocrine activities followed by stress-induced enhanced Th2 and Th17 immune responses and attenuated regulatory T (Treg cell responses that are closely linked with asthma exacerbation. We will place a special focus on our own data that has emphasized the continuity from central sensing of psychological stress to enhanced eosinophilic airway inflammation. The mechanism that modulates psychological stress-induced exacerbation of allergic asthma through neuroendocrine activities is thought to involve a series of consecutive pathological events from the brain to the lung, which implies there to be a “neuropsychiatry phenotype” in asthma.

  1. Probiotic Lactobacilli Modulate Staphylococcus aureus-Induced Activation of Conventional and Unconventional T cells and NK cells

    Directory of Open Access Journals (Sweden)

    Maria A Johansson

    2016-07-01

    Full Text Available Lactobacilli are probiotic commensal bacteria and potent modulators of immunity. When present in the gut or supplemented as probiotics, they beneficially modulate ex vivo immune responsiveness. Further, factors derived from several lactobacilli strains act immune regulato-ry in vitro. In contrast, Staphylococcus aureus (S. aureus is known to induce excessive T cell activation. In this study we aimed to investigate S. aureus-induced activation of human muco-sal associated invariant T cells (MAIT cells, γδ T cells, NK cells, as well as of conventional CD4+ and CD8+ T cells in vitro. Further, we investigated if lactobacilli-derived factors could modulate their activation.PBMC were cultured with S. aureus 161:2 cell free supernatant (CFS, staphylococcal en-terotoxin A or CD3/CD28-beads alone or in combination with Lactobacillus rhamnosus (L. rhamnosus GG-CFS or Lactobacillus reuteri (L. reuteri DSM 17938-CFS, and activation of T and NK cells was evaluated. S. aureus-CFS induced IFN-γ and CD107a expression as well as proliferation. Co-stimulation with lactobacilli-CFS dampened lymphocyte activation in all cell types analysed. Pre-incubation with lactobacilli-CFS was enough to reduce subsequent activation and the ab-sence of APC or APC-derived IL-10 did not prevent lactobacilli-mediated dampening. Final-ly, lactate selectively dampened activation of unconventional T cells and NK cells. In summary, we show that molecules present in the lactobacilli-CFS are able to directly dampen in vitro activation of conventional and unconventional T cells and of NK cells. This study provides novel insights on the immune modulatory nature of probiotic lactobacilli and suggests a role for lactobacilli in modulation of induced T and NK cell activation.

  2. BAY 87-2243, a highly potent and selective inhibitor of hypoxia-induced gene activation has antitumor activities by inhibition of mitochondrial complex I

    International Nuclear Information System (INIS)

    Ellinghaus, Peter; Heisler, Iring; Unterschemmann, Kerstin; Haerter, Michael; Beck, Hartmut; Greschat, Susanne; Ehrmann, Alexander; Summer, Holger; Flamme, Ingo; Oehme, Felix; Thierauch, Karlheinz; Michels, Martin; Hess-Stumpp, Holger; Ziegelbauer, Karl

    2013-01-01

    The activation of the transcription factor hypoxia-inducible factor-1 (HIF-1) plays an essential role in tumor development, tumor progression, and resistance to chemo- and radiotherapy. In order to identify compounds targeting the HIF pathway, a small molecule library was screened using a luciferase-driven HIF-1 reporter cell line under hypoxia. The high-throughput screening led to the identification of a class of aminoalkyl-substituted compounds that inhibited hypoxia-induced HIF-1 target gene expression in human lung cancer cell lines at low nanomolar concentrations. Lead structure BAY 87-2243 was found to inhibit HIF-1α and HIF-2α protein accumulation under hypoxic conditions in non-small cell lung cancer (NSCLC) cell line H460 but had no effect on HIF-1α protein levels induced by the hypoxia mimetics desferrioxamine or cobalt chloride. BAY 87-2243 had no effect on HIF target gene expression levels in RCC4 cells lacking Von Hippel–Lindau (VHL) activity nor did the compound affect the activity of HIF prolyl hydroxylase-2. Antitumor activity of BAY 87-2243, suppression of HIF-1α protein levels, and reduction of HIF-1 target gene expression in vivo were demonstrated in a H460 xenograft model. BAY 87-2243 did not inhibit cell proliferation under standard conditions. However under glucose depletion, a condition favoring mitochondrial ATP generation as energy source, BAY 87-2243 inhibited cell proliferation in the nanomolar range. Further experiments revealed that BAY 87-2243 inhibits mitochondrial complex I activity but has no effect on complex III activity. Interference with mitochondrial function to reduce hypoxia-induced HIF-1 activity in tumors might be an interesting therapeutic approach to overcome chemo- and radiotherapy-resistance of hypoxic tumors

  3. Osteopontin induces β-catenin signaling through activation of Akt in prostate cancer cells

    International Nuclear Information System (INIS)

    Robertson, Brian W.; Chellaiah, Meenakshi A.

    2010-01-01

    Secretion of osteopontin (OPN) by cancer cells is a known mediator of tumorigenesis and cancer progression in both experimental and clinical studies. Our work demonstrates that OPN can activate Akt, an important step in cancer progression. Both ILK and PI3K are integral proteins in the OPN/Akt pathway, as inhibition of either kinase leads to a loss of OPN-mediated Akt activation. Subsequent to OPN-induced Akt activation, we observe inactivation of GSK-3β, a regulator of β-catenin. Osteopontin stimulation leads to an overall increase in β-catenin protein levels with a resultant transfer of β-catenin to the nucleus. Through the nuclear import of β-catenin, OPN increases both the transcription and protein levels of MMP-7 and CD44, which are known TCF/LEF transcription targets. This work describes an important aspect of cancer progression induced by OPN.

  4. Oleic Acid Induces Lung Injury in Mice through Activation of the ERK Pathway

    Directory of Open Access Journals (Sweden)

    Cassiano Felippe Gonçalves-de-Albuquerque

    2012-01-01

    Full Text Available Oleic acid (OA can induce acute lung injury in experimental models. In the present work, we used intratracheal OA injection to show augmented oedema formation, cell migration and activation, lipid mediator, and cytokine productions in the bronchoalveolar fluids of Swiss Webster mice. We also demonstrated that OA-induced pulmonary injury is dependent on ERK1/2 activation, since U0126, an inhibitor of ERK1/2 phosphorylation, blocked neutrophil migration, oedema, and lipid body formation as well as IL-6, but not IL-1β production. Using a mice strain carrying a null mutation for the TLR4 receptor, we proved that increased inflammatory parameters after OA challenges were not due to the activation of the TLR4 receptor. With OA being a Na/K-ATPase inhibitor, we suggest the possible involvement of this enzyme as an OA target triggering lung inflammation.

  5. The Effect of Tallow As Lipase Inducer on Total of Aspergillus Niger, Lipolitic Activity and Lipase Yield

    Directory of Open Access Journals (Sweden)

    Manik Eirry Sawitri

    2012-02-01

    Full Text Available The objectives of this research was to determined of tallow addition with different concentration as lipase Aspergillus niger inducer to total of A. niger, lipolitic activity and lipase yield. The result showed that tallow addition as inducer in the lipase A. niger production gave no significant effect on total of A. niger (5.3 x 107 – 1.7 x 108 cfu/gram in the medium. Tallow addition gave a highly significant effect on lipolytic activity and yield of lipase A. niger. Lipolytic activity ranged between 32.0354 – 53.1197 U/mg protein, while the yield of lipase was 6.6418–7.8941 µg/ml. The conclusion of this research was the addition of tallow for 8% as the lipase inducer of A. niger on lipase production was  more effective to obtain the optimal result. Keywords : Tallow, lipase, inducer, Aspergillus niger

  6. Valproic acid induces hair regeneration in murine model and activates alkaline phosphatase activity in human dermal papilla cells.

    Directory of Open Access Journals (Sweden)

    Soung-Hoon Lee

    Full Text Available Alopecia is the common hair loss problem that can affect many people. However, current therapies for treatment of alopecia are limited by low efficacy and potentially undesirable side effects. We have identified a new function for valproic acid (VPA, a GSK3β inhibitor that activates the Wnt/β-catenin pathway, to promote hair re-growth in vitro and in vivo.Topical application of VPA to male C3H mice critically stimulated hair re-growth and induced terminally differentiated epidermal markers such as filaggrin and loricrin, and the dermal papilla marker alkaline phosphatase (ALP. VPA induced ALP in human dermal papilla cells by up-regulating the Wnt/β-catenin pathway, whereas minoxidil (MNX, a drug commonly used to treat alopecia, did not significantly affect the Wnt/β-catenin pathway. VPA analogs and other GSK3β inhibitors that activate the Wnt/β-catenin pathway such as 4-phenyl butyric acid, LiCl, and BeCl(2 also exhibited hair growth-promoting activities in vivo. Importantly, VPA, but not MNX, successfully stimulate hair growth in the wounds of C3H mice.Our findings indicate that small molecules that activate the Wnt/β-catenin pathway, such as VPA, can potentially be developed as drugs to stimulate hair re-growth.

  7. Wen-Luo-Tong Prevents Glial Activation and Nociceptive Sensitization in a Rat Model of Oxaliplatin-Induced Neuropathic Pain.

    Science.gov (United States)

    Deng, Bo; Jia, Liqun; Pan, Lin; Song, Aiping; Wang, Yuanyuan; Tan, Huangying; Xiang, Qing; Yu, Lili; Ke, Dandan

    2016-01-01

    One of the main dose-limiting complications of the chemotherapeutic agent oxaliplatin (OXL) is painful neuropathy. Glial activation and nociceptive sensitization may be responsible for the mechanism of neuropathic pain. The Traditional Chinese Medicine (TCM) Wen-luo-tong (WLT) has been widely used in China to treat chemotherapy induced neuropathic pain. However, there is no study on the effects of WLT on spinal glial activation induced by OXL. In this study, a rat model of OXL-induced chronic neuropathic pain was established and WLT was administrated. Pain behavioral tests and morphometric examination of dorsal root ganglia (DRG) were conducted. Glial fibrillary acidic protein (GFAP) immunostaining was performed, glial activation was evaluated, and the excitatory neurotransmitter substance P (SP) and glial-derived proinflammatory cytokine tumor necrosis factor-α (TNF-α) were analyzed. WLT treatment alleviated OXL-induced mechanical allodynia and mechanical hyperalgesia. Changes in the somatic, nuclear, and nucleolar areas of neurons in DRG were prevented. In the spinal dorsal horn, hypertrophy and activation of GFAP-positive astrocytes were averted, and the level of GFAP mRNA decreased significantly. Additionally, TNF-α mRNA and protein levels decreased. Collectively, these results indicate that WLT reversed both glial activation in the spinal dorsal horn and nociceptive sensitization during OXL-induced chronic neuropathic pain in rats.

  8. Effects of wearing bio-active material coated fabric against γ-irradiation-induced cellular damaged in Sprague-Dawley rats

    International Nuclear Information System (INIS)

    Kang, Jung Ae; Kim, Hye Rim; Yoon, Sun Hye; Nam, Sang Hyun; Park, Sang Hyun; Jang, Beom Su; Go, Kyung Chan; Yang, Gwang Wung; Rho, Young Hwan; Park, Hyo Suk

    2016-01-01

    Ionizing radiation causes cellular damage and death through the direct damage and/or indirectly the production of ROS, which induces oxidative stress. This study was designed to evaluate the in vivo radioprotective effects of a bio-active material coated fabric (BMCF) against γ-irradiation-induced cellular damage in Sprague-Dawley (SD) rats. Healthy male SD rats wore bio-active material coated (concentrations in 10% and 30%) fabric for 7 days after 3 Gy of γ-irradiation. Radioprotective effects were evaluated by performing various biochemical assays including spleen and thymus index, WBC count, hepatic damage marker enzymes [aspartate transaminase (AST) and alanine transaminase (ALT)] in plasma, liver antioxidant enzymes, and mitochondrial activity in muscle. Exposure to γ-irradiation resulted in hepatocellular and immune systemic damage. Gamma-irradiation induced decreases in antioxidant enzymes. However, wearing the BMCF-30% decreased significantly AST and ALT activities in plasma. Furthermore, wearing the BMCF-30% increased SOD (superoxide dismutase) and mitochondrial activity. These results suggest that wearing BMCF offers effective radioprotection against γ-irradiation-induced cellular damage in SD rats

  9. Effects of wearing bio-active material coated fabric against γ-irradiation-induced cellular damaged in Sprague-Dawley rats

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Jung Ae; Kim, Hye Rim; Yoon, Sun Hye; Nam, Sang Hyun; Park, Sang Hyun; Jang, Beom Su [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of); Go, Kyung Chan; Yang, Gwang Wung; Rho, Young Hwan; Park, Hyo Suk [Research and Development Center, VENTEX Co. Ltd., Seoul (Korea, Republic of)

    2016-09-15

    Ionizing radiation causes cellular damage and death through the direct damage and/or indirectly the production of ROS, which induces oxidative stress. This study was designed to evaluate the in vivo radioprotective effects of a bio-active material coated fabric (BMCF) against γ-irradiation-induced cellular damage in Sprague-Dawley (SD) rats. Healthy male SD rats wore bio-active material coated (concentrations in 10% and 30%) fabric for 7 days after 3 Gy of γ-irradiation. Radioprotective effects were evaluated by performing various biochemical assays including spleen and thymus index, WBC count, hepatic damage marker enzymes [aspartate transaminase (AST) and alanine transaminase (ALT)] in plasma, liver antioxidant enzymes, and mitochondrial activity in muscle. Exposure to γ-irradiation resulted in hepatocellular and immune systemic damage. Gamma-irradiation induced decreases in antioxidant enzymes. However, wearing the BMCF-30% decreased significantly AST and ALT activities in plasma. Furthermore, wearing the BMCF-30% increased SOD (superoxide dismutase) and mitochondrial activity. These results suggest that wearing BMCF offers effective radioprotection against γ-irradiation-induced cellular damage in SD rats.

  10. Macrophage activation induced by Brucella DNA suppresses bacterial intracellular replication via enhancing NO production.

    Science.gov (United States)

    Liu, Ning; Wang, Lin; Sun, Changjiang; Yang, Li; Tang, Bin; Sun, Wanchun; Peng, Qisheng

    2015-12-01

    Brucella DNA can be sensed by TLR9 on endosomal membrane and by cytosolic AIM2-inflammasome to induce proinflammatory cytokine production that contributes to partially activate innate immunity. Additionally, Brucella DNA has been identified to be able to act as a major bacterial component to induce type I IFN. However, the role of Brucella DNA in Brucella intracellular growth remains unknown. Here, we showed that stimulation with Brucella DNA promote macrophage activation in TLR9-dependent manner. Activated macrophages can suppresses wild type Brucella intracellular replication at early stage of infection via enhancing NO production. We also reported that activated macrophage promotes bactericidal function of macrophages infected with VirB-deficient Brucella at the early or late stage of infection. This study uncovers a novel function of Brucella DNA, which can help us further elucidate the mechanism of Brucella intracellular survival. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Apoptosis induced by penta-acetyl geniposide in C6 glioma cells is associated with JNK activation and Fas ligand induction

    International Nuclear Information System (INIS)

    Peng, C.-H.; Tseng, T.-H.; Huang, C.-N.; Hsu, S.-P.; Wang, C.-J.

    2005-01-01

    In our previous study, penta-acetyl geniposide ((AC) 5 GP) is suggested to induce tumor cell apoptosis through the specific activation of PKCδ. However, the downstream signal pathway of PKCδ has not yet been investigated. It was shown that JNK may play an important role in the regulation of apoptosis and could be a possible downstream signal of PKCδ isoforms. In the present study, we investigate whether JNK is involved in (AC) 5 GP induced apoptosis. The result reveals that (AC) 5 GP induces JNK activation and c-Jun phosphorylation thus stimulating the expression of Fas-L and Fas. Using SP600125 to block JNK activation shows that (AC) 5 GP-mediated apoptosis and related proteins expression are attenuated. Furthermore, we find that the (AC) 5 GP induces apoptosis through the activation of JNK/Jun/Fas L/Fas/caspase 8/caspase 3, a mitochondria-independent pathway. The JNK pathway is suggested to be the downstream signal of PKCδ, since rottlerin impedes (AC) 5 GP-induced JNK activation. Therefore, (AC) 5 GP mediates cell death via activation of PKCδ/JNK/FasL cascade signaling

  12. Role of visible light-activated photocatalyst on the reduction of anthrax spore-induced mortality in mice.

    Directory of Open Access Journals (Sweden)

    Jyh-Hwa Kau

    Full Text Available BACKGROUND: Photocatalysis of titanium dioxide (TiO(2 substrates is primarily induced by ultraviolet light irradiation. Anion-doped TiO(2 substrates were shown to exhibit photocatalytic activities under visible-light illumination, relative environmentally-friendly materials. Their anti-spore activity against Bacillus anthracis, however, remains to be investigated. We evaluated these visible-light activated photocatalysts on the reduction of anthrax spore-induced pathogenesis. METHODOLOGY/PRINCIPAL FINDINGS: Standard plating method was used to determine the inactivation of anthrax spore by visible light-induced photocatalysis. Mouse models were further employed to investigate the suppressive effects of the photocatalysis on anthrax toxin- and spore-mediated mortality. We found that anti-spore activities of visible light illuminated nitrogen- or carbon-doped titania thin films significantly reduced viability of anthrax spores. Even though the spore-killing efficiency is only approximately 25%, our data indicate that spores from photocatalyzed groups but not untreated groups have a less survival rate after macrophage clearance. In addition, the photocatalysis could directly inactivate lethal toxin, the major virulence factor of B. anthracis. In agreement with these results, we found that the photocatalyzed spores have tenfold less potency to induce mortality in mice. These data suggest that the photocatalysis might injury the spores through inactivating spore components. CONCLUSION/SIGNIFICANCE: Photocatalysis induced injuries of the spores might be more important than direct killing of spores to reduce pathogenicity in the host.

  13. Palm kernel cake extract exerts hepatoprotective activity in heat-induced oxidative stress in chicken hepatocytes.

    Science.gov (United States)

    Oskoueian, Ehsan; Abdullah, Norhani; Idrus, Zulkifli; Ebrahimi, Mahdi; Goh, Yong Meng; Shakeri, Majid; Oskoueian, Armin

    2014-10-02

    Palm kernel cake (PKC), the most abundant by-product of oil palm industry is believed to contain bioactive compounds with hepatoprotective potential. These compounds may serve as hepatoprotective agents which could help the poultry industry to alleviate adverse effects of heat stress on liver function in chickens. This study was performed to evaluate the hepatoprotective potential of PKC extract in heat-induced oxidative stress in chicken hepatocytes. The nature of the active metabolites and elucidation of the possible mechanism involved were also investigated. The PKC extract possessed free radical scavenging activity with values significantly (p < 0.05) lower than silymarin as the reference antioxidant. Heat-induced oxidative stress in chicken hepatocyte impaired the total protein, lipid peroxidation and antioxidant enzymes activity significantly (p < 0.05). Treatment of heat-induced hepatocytes with PKC extract (125 μg/ml) and silymarin as positive control increased these values significantly (p < 0.05). The real time PCR and western blot analyses revealed the significant (p < 0.05) up-regulation of oxidative stress biomarkers including TNF-like, IFN-γ and IL-1β genes; NF-κB, COX-2, iNOS and Hsp70 proteins expression upon heat stress in chicken hepatocytes. The PKC extract and silymarin were able to alleviate the expression of all of these biomarkers in heat-induced chicken hepatocytes. The gas chromatography-mass spectrometry analysis of PKC extract showed the presence of fatty acids, phenolic compounds, sugar derivatives and other organic compounds such as furfural which could be responsible for the observed hepatoprotective activity. Palm kernel cake extract could be a potential agent to protect hepatocytes function under heat induced oxidative stress.

  14. p38 mitogen-activated protein kinase up-regulates LPS-induced NF-κB activation in the development of lung injury and RAW 264.7 macrophages

    International Nuclear Information System (INIS)

    Kim, Hee J.; Lee, Hui S.; Chong, Young H.; Kang, Jihee Lee

    2006-01-01

    Clarification of the key regulatory steps that lead to nuclear factor-kappa B (NF-κB) under cellular and pathological conditions is very important. The action of p38 mitogen-activated protein kinase (MAPK) on the upstream of NF-κB activation remains controversial. To examine this issue using an in vivo lung injury model, SB203580, a p38 MAPK inhibitor was given intraorally 1 h prior to lipopolysaccharide (LPS) treatment (intratracheally). The mice were sacrificed 4 h after LPS treatment. SB203580 substantially suppressed LPS-induced rises in p38 MAPK phosphorylation, neutrophil recruitment, total protein content in bronchoalveolar lavage fluid, and apoptosis of bronchoalveolar cells. Furthermore, SB203580 blocked LPS-induced NF-κB activation in lung tissue through down-regulation of serine phosphorylation, degradation of IκB-α, and consequent translocation of the p65 subunit of NF-κB to the nucleus. It is likely that, in cultured RAW 264.7 macrophages, SB203580 also blocked LPS-induced NF-κB activation in a dose-dependent manner. SB203580 inhibited LPS-induced serine phosphorylation, degradation of IκB-α, and tyrosine phosphorylation of p65 NF-κB. These data indicate that p38 MAPK acts upstream of LPS-induced NF-κB activation by modulating the phosphorylation of IκB-α and p65 NF-κB during acute lung injury. Because LPS-stimulated macrophages may contribute to inflammatory lung injury, the inhibition of the p38 MAPK-mediated intracellular signaling pathway leading to NF-κB activation represents a target for the attenuation of lung inflammation and parenchymal damage

  15. TGEV nucleocapsid protein induces cell cycle arrest and apoptosis through activation of p53 signaling

    International Nuclear Information System (INIS)

    Ding, Li; Huang, Yong; Du, Qian; Dong, Feng; Zhao, Xiaomin; Zhang, Wenlong; Xu, Xingang; Tong, Dewen

    2014-01-01

    Highlights: • TGEV N protein reduces cell viability by inducing cell cycle arrest and apoptosis. • TGEV N protein induces cell cycle arrest and apoptosis by regulating p53 signaling. • TGEV N protein plays important roles in TGEV-induced cell cycle arrest and apoptosis. - Abstract: Our previous studies showed that TGEV infection could induce cell cycle arrest and apoptosis via activation of p53 signaling in cultured host cells. However, it is unclear which viral gene causes these effects. In this study, we investigated the effects of TGEV nucleocapsid (N) protein on PK-15 cells. We found that TGEV N protein suppressed cell proliferation by causing cell cycle arrest at the S and G2/M phases and apoptosis. Characterization of various cellular proteins that are involved in regulating cell cycle progression demonstrated that the expression of N gene resulted in an accumulation of p53 and p21, which suppressed cyclin B1, cdc2 and cdk2 expression. Moreover, the expression of TGEV N gene promoted translocation of Bax to mitochondria, which in turn caused the release of cytochrome c, followed by activation of caspase-3, resulting in cell apoptosis in the transfected PK-15 cells following cell cycle arrest. Further studies showed that p53 inhibitor attenuated TGEV N protein induced cell cycle arrest at S and G2/M phases and apoptosis through reversing the expression changes of cdc2, cdk2 and cyclin B1 and the translocation changes of Bax and cytochrome c induced by TGEV N protein. Taken together, these results demonstrated that TGEV N protein might play an important role in TGEV infection-induced p53 activation and cell cycle arrest at the S and G2/M phases and apoptosis occurrence

  16. Gamma radiation induced enhancement in the antioxidant and radioprotective activities of flavonoids

    International Nuclear Information System (INIS)

    Arul Anantha Kumar, A.; Sonwani, Swetha; Bakkiam, D.

    2018-01-01

    Recently γ-radiation has been used as a tool to induce structural changes in natural biomolecules to enhance their biological and physiological properties. Flavonoids are a family of plant derived polyphenolic compounds having considerable scientific and therapeutic importance. Structurally they are the benzo-γ-pyrone derivatives containing phenolic and pyrane rings. Flavonoid radioprotection is an intense area of research thanks to features like natural origin, effectiveness at non-toxic dose levels and lack of side effects. But till date no report is available on the effect of γ-radiation mediated enhancement in radioprotection activity of flavonoids. In view of this the present study was carried out to determine the γ-radiation induced structural changes in selected flavonoids i.e. apigenin, naringenin and genistein and also to explore the possibility of enhancement in their antioxidant and radioprotective activities

  17. LASER INDUCED SELECTIVE ACTIVATION UTILIZING AUTO-CATALYTIC ELECTROLESS PLATING ON POLYMER SURFACE

    DEFF Research Database (Denmark)

    Zhang, Yang; Nielsen, Jakob Skov; Tang, Peter Torben

    2009-01-01

    . Characterization of the deposited copper layer was used to select and improve laser parameters. Several types of polymers with different melting points were used as substrate. Using the above mentioned laser treatment, standard grades of thermoplastic materials such as ABS, SAN, PE, PC and others have been......This paper presents a new method for selective micro metallization of polymers induced by laser. An Nd: YAG laser was employed to draw patterns on polymer surfaces using a special set-up. After subsequent activation and auto-catalytic electroless plating, copper only deposited on the laser tracks....... Induced by the laser, porous and rough structures are formed on the surface, which favours the palladium attachment during the activation step prior to the metallization. Laser focus detection, scanning electron microscopy (SEM) and other instruments were used to analyze the topography of the laser track...

  18. Aprotic solvent systems provide mechanistic windows for biomolecular reactions: nucleic acid proton exchange

    International Nuclear Information System (INIS)

    McConnell, B.; Tan, A.

    1986-01-01

    Detection of general acid-base catalysis of proton transfer reactions in aqueous cytidine (or adenosine) is completely obscured by the highly reactive endocyclic protonated species of the nucleobase, whose amino proton lifetime is much shorter than that of the neutral form. In aqueous solution, protonation of the nucleobase always accompanies protonation of the buffer catalyzing exchange. However, in DMSO/water mixtures this is not the case; aqueous protonated acetate or chloroacetate can be added to cytidine in DMSO solutions without further dissociation of the buffer or significant protonation of cytidine N-3. Under these conditions general acid catalysis is observed, which involves an H-bonded complex between cytidine (N-3) and the buffer acid. Increased amino proton exchange in response to H-bond donation to C(N-3) is further suggested by increased 1 H NMR saturation-recovery rates with the formation of G-C base-pairs in DMSO and by the inverse dependence of amino proton exchange on nucleoside concentration

  19. Preliminary Experiment on Neutron-Induced Mn Activity in Mn-Cd Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Broda, E.

    1942-07-01

    This report was written by E. Broda, J. Gueron and L. Kowarski at the Cavendish Laboratory (Cambridge) in June 1942 and is about a preliminary experiment on neutron-induced Mn activity in Mn-Cd solutions. The description of the experiment and the results can be found also in this report. (nowak)

  20. Activity of cell wall degrading glycanases in methyl jasmonate-induced leaf abscission in Kalanchoe blossfeldiana

    Directory of Open Access Journals (Sweden)

    Marian Saniewski

    2013-12-01

    Full Text Available It was found previously that methyl jasmonate (JA-Me induced leaf abscission in Kalanchoe blossfeldiana. In present studies it was shown that JA-Me markedly increased the total activities of cellulase, polygalacturonase, pectinase and xylanase in petioles, but did not affect activities of these enzymes in the blades and apical part of shoots of K. blossfeldiana. These results suggest that methyl jasmonate promotes the degradation of cell wall polysaccharides in the abscission zone and in this way induces leaf abscission in Kalanchoe blossfeldiana.

  1. In vitro anti-leukemic activity and chemical transformation of the 5'-chloro-5'-deoxy derivative of cyclo-cytidine

    International Nuclear Information System (INIS)

    Stankovicova, M.; Bachrata, M.; Sveda, P.; Rauko, P.; Blesova, P.

    1995-01-01

    Hydrochloride of 5'-chloro-5'-deoxy-cytocytidine (Cl-cC) is an analogue of hydrochloride (cC), a pro-drug of the compound with of the compound with the strong anti-leukemic activity arabinosylcytosine (araC). This paper is devoted to the study of its cytotoxic activity in vitro and to the effect of acid alkaline conditions and temperature on its stability. Cl-cC inhibits not only the growth of L1210 leukemia cells in vitro and the DNA synthesis (IC 50 = 0.09 μmol/dm 3 ) but, at the same time, it has a weak effect on RNA synthesis (IC 50 > 250 μmol/dm 3 ) and no effect on proteosynthesis. In alkaline conditions Cl-cC is transformed to 5'-chloro-araC and 2',5'-anhydro-araC but is more stable in acid solutions. (author)

  2. Inflammasome priming is similar for francisella species that differentially induce inflammasome activation.

    Directory of Open Access Journals (Sweden)

    Mohammed G Ghonime

    Full Text Available Inflammasome activation is a two-step process where step one, priming, prepares the inflammasome for its subsequent activation, by step two. Classically step one can be induced by LPS priming followed by step two, high dose ATP. Furthermore, when IL-18 processing is used as the inflammasome readout, priming occurs before new protein synthesis. In this context, how intracellular pathogens such as Francisella activate the inflammasome is incompletely understood, particularly regarding the relative importance of priming versus activation steps. To better understand these events we compared Francisella strains that differ in virulence and ability to induce inflammasome activation for their relative effects on step one vs. step two. When using the rapid priming model, i.e., 30 min priming by live or heat killed Francisella strains (step 1, followed by ATP (step 2, we found no difference in IL-18 release, p20 caspase-1 release and ASC oligomerization between Francisella strains (F. novicida, F. holarctica -LVS and F. tularensis Schu S4. This priming is fast, independent of bacteria viability, internalization and phagosome escape, but requires TLR2-mediated ERK phosphorylation. In contrast to their efficient priming capacity, Francisella strains LVS and Schu S4 were impaired in inflammasome triggering compared to F. novicida. Thus, observed differences in inflammasome activation by F. novicida, LVS and Schu S4 depend not on differences in priming but rather on their propensity to trigger the primed inflammasome.

  3. Buddleja officinalis inhibits high glucose-induced matrix metalloproteinase activity in human umbilical vein endothelial cells.

    Science.gov (United States)

    Lee, Yun Jung; Kang, Dae Gill; Kim, Jin Sook; Lee, Ho Sub

    2008-12-01

    The aim of the present investigation was to investigate whether an aqueous extract of Buddleja officinalis (ABO), a traditional Korean herbal medicine, suppresses the endothelial extracellular matrix degradation under high glucose condition. The incubation with high concentration of glucose (25 mM) increased significantly matrix metalloproteinase (MMP)-2/-9 expressions and activities in primary cultured human umbilical vein endothelial cells (HUVEC). Pretreatment with ABO decreased high glucose-induced increase of MMP-2/-9 activities in a dose-dependent manner. Real time qRT-PCR revealed that high glucose-induced MMP-2/-9 mRNA expression levels were attenuated by pretreatment with ABO. High glucose-induced MCP-1 and IL-8 mRNA expression levels also decreased by ABO. ABO decreased high glucose-induced hydrogen peroxide production, oxidative stress marker. These results provide new insights into the pathophysiological mechanisms for anti-inflammatory properties of ABO in vascular diseases associated with diabetes mellitus. (c) 2008 John Wiley & Sons, Ltd.

  4. Acrolein-induced activation of mitogen-activated protein kinase signaling is mediated by alkylation of thioredoxin reductase and thioredoxin 1.

    Science.gov (United States)

    Randall, Matthew J; Spiess, Page C; Hristova, Milena; Hondal, Robert J; van der Vliet, Albert

    2013-01-01

    Cigarette smoking remains a major health concern worldwide, and many of the adverse effects of cigarette smoke (CS) can be attributed to its abundant electrophilic aldehydes, such as acrolein (2-propenal). Previous studies indicate that acrolein readily reacts with thioredoxin reductase 1 (TrxR1), a critical enzyme involved in regulation of thioredoxin (Trx)-mediated redox signaling, by alkylation at its selenocysteine (Sec) residue. Because alkylation of Sec within TrxR1 has significant implications for its enzymatic function, we explored the potential importance of TrxR1 alkylation in acrolein-induced activation or injury of bronchial epithelial cells. Exposure of human bronchial epithelial HBE1 cells to acrolein (1-30 μM) resulted in dose-dependent loss of TrxR thioredoxin reductase activity, which coincided with its alkylation, as determined by biotin hydrazide labeling, and was independent of initial GSH status. To test the involvement of TrxR1 in acrolein responses in HBE1 cells, we suppressed TrxR1 using siRNA silencing or augmented TrxR1 by cell supplementation with sodium selenite. Acrolein exposure of HBE1 cells induced dose-dependent activation of the MAP kinases, extracellular regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38, and activation of JNK was markedly enhanced after selenite-mediated induction of TrxR1, and was associated with increased alkylation of TrxR1. Conversely, siRNA silencing of TrxR1 significantly suppressed the ability of acrolein to activate JNK, and also appeared to attenuate acrolein-dependent activation of ERK and p38. Alteration of initial TrxR1 levels by siRNA or selenite supplementation also affected initial Trx1 redox status and acrolein-mediated alkylation of Trx1, but did not significantly affect acrolein-mediated activation of HO-1 or cytotoxicity. Collectively, our findings indicate that alkylation of TrxR1 and/or Trx1 may contribute directly to acrolein-mediated activation of MAP kinases such as JNK, and

  5. Acrolein-induced activation of mitogen-activated protein kinase signaling is mediated by alkylation of thioredoxin reductase and thioredoxin 1

    Directory of Open Access Journals (Sweden)

    Matthew J. Randall

    2013-01-01

    Full Text Available Cigarette smoking remains a major health concern worldwide, and many of the adverse effects of cigarette smoke (CS can be attributed to its abundant electrophilic aldehydes, such as acrolein (2-propenal. Previous studies indicate that acrolein readily reacts with thioredoxin reductase 1 (TrxR1, a critical enzyme involved in regulation of thioredoxin (Trx-mediated redox signaling, by alkylation at its selenocysteine (Sec residue. Because alkylation of Sec within TrxR1 has significant implications for its enzymatic function, we explored the potential importance of TrxR1 alkylation in acrolein-induced activation or injury of bronchial epithelial cells. Exposure of human bronchial epithelial HBE1 cells to acrolein (1–30 μM resulted in dose-dependent loss of TrxR thioredoxin reductase activity, which coincided with its alkylation, as determined by biotin hydrazide labeling, and was independent of initial GSH status. To test the involvement of TrxR1 in acrolein responses in HBE1 cells, we suppressed TrxR1 using siRNA silencing or augmented TrxR1 by cell supplementation with sodium selenite. Acrolein exposure of HBE1 cells induced dose-dependent activation of the MAP kinases, extracellular regulated kinase (ERK, c-Jun N-terminal kinase (JNK, and p38, and activation of JNK was markedly enhanced after selenite-mediated induction of TrxR1, and was associated with increased alkylation of TrxR1. Conversely, siRNA silencing of TrxR1 significantly suppressed the ability of acrolein to activate JNK, and also appeared to attenuate acrolein-dependent activation of ERK and p38. Alteration of initial TrxR1 levels by siRNA or selenite supplementation also affected initial Trx1 redox status and acrolein-mediated alkylation of Trx1, but did not significantly affect acrolein-mediated activation of HO-1 or cytotoxicity. Collectively, our findings indicate that alkylation of TrxR1 and/or Trx1 may contribute directly to acrolein-mediated activation of MAP kinases

  6. Dasatinib inhibits both osteoclast activation and prostate cancer PC-3-cell-induced osteoclast formation.

    Science.gov (United States)

    Araujo, John C; Poblenz, Ann; Corn, Paul; Parikh, Nila U; Starbuck, Michael W; Thompson, Jerry T; Lee, Francis; Logothetis, Christopher J; Darnay, Bryant G

    2009-11-01

    Therapies to target prostate cancer bone metastases have only limited effects. New treatments are focused on the interaction between cancer cells, bone marrow cells and the bone matrix. Osteoclasts play an important role in the development of bone tumors caused by prostate cancer. Since Src kinase has been shown to be necessary for osteoclast function, we hypothesized that dasatinib, a Src family kinase inhibitor, would reduce osteoclast activity and prostate cancer (PC-3) cell-induced osteoclast formation. Dasatinib inhibited RANKL-induced osteoclast differentiation of bone marrow-derived monocytes with an EC(50) of 7.5 nM. PC-3 cells, a human prostate cancer cell line, were able to differentiate RAW 264.7 cells, a murine monocytic cell line, into osteoclasts, and dasatinib inhibited this differentiation. In addition, conditioned medium from PC-3 cell cultures was able to differentiate RAW 264.7 cells into osteoclasts and this too, was inhibited by dasatinib. Even the lowest concentration of dasatinib, 1.25 nmol, inhibited osteoclast differentiation by 29%. Moreover, dasatinib inhibited osteoclast activity by 58% as measured by collagen 1 release. We performed in vitro experiments utilizing the Src family kinase inhibitor dasatinib to target osteoclast activation as a means of inhibiting prostate cancer bone metastases. Dasatinib inhibits osteoclast differentiation of mouse primary bone marrow-derived monocytes and PC-3 cell-induced osteoclast differentiation. Dasatinib also inhibits osteoclast degradation activity. Inhibiting osteoclast differentiation and activity may be an effective targeted therapy in patients with prostate cancer bone metastases.

  7. Oxidative stress plays a role in high glucose-induced activation of pancreatic stellate cells

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Gyeong Ryul; Lee, Esder; Chun, Hyun-Ji; Yoon, Kun-Ho; Ko, Seung-Hyun; Ahn, Yu-Bae; Song, Ki-Ho, E-mail: kihos@catholic.ac.kr

    2013-09-20

    Highlights: •High glucose increased production of reactive oxygen species in cultured pancreatic stellate cells. •High glucose facilitated the activation of these cells. •Antioxidant treatment attenuated high glucose-induced activation of these cells. -- Abstract: The activation of pancreatic stellate cells (PSCs) is thought to be a potential mechanism underlying islet fibrosis, which may contribute to progressive β-cell failure in type 2 diabetes. Recently, we demonstrated that antioxidants reduced islet fibrosis in an animal model of type 2 diabetes. However, there is no in vitro study demonstrating that high glucose itself can induce oxidative stress in PSCs. Thus, PSCs were isolated and cultured from Sprague Dawley rats, and treated with high glucose for 72 h. High glucose increased the production of reactive oxygen species. When treated with high glucose, freshly isolated PSCs exhibited myofibroblastic transformation. During early culture (passage 1), PSCs treated with high glucose contained an increased number of α-smooth muscle actin-positive cells. During late culture (passages 2–5), PSCs treated with high glucose exhibited increases in cell proliferation, the expression of fibronectin and connective tissue growth factor, release of interleukin-6, transforming growth factor-β and collagen, and cell migration. Finally, the treatment of PSCs with high glucose and antioxidants attenuated these changes. In conclusion, we demonstrated that high glucose increased oxidative stress in primary rat PSCs, thereby facilitating the activation of these cells, while antioxidant treatment attenuated high glucose-induced PSC activation.

  8. Oxidative stress plays a role in high glucose-induced activation of pancreatic stellate cells

    International Nuclear Information System (INIS)

    Ryu, Gyeong Ryul; Lee, Esder; Chun, Hyun-Ji; Yoon, Kun-Ho; Ko, Seung-Hyun; Ahn, Yu-Bae; Song, Ki-Ho

    2013-01-01

    Highlights: •High glucose increased production of reactive oxygen species in cultured pancreatic stellate cells. •High glucose facilitated the activation of these cells. •Antioxidant treatment attenuated high glucose-induced activation of these cells. -- Abstract: The activation of pancreatic stellate cells (PSCs) is thought to be a potential mechanism underlying islet fibrosis, which may contribute to progressive β-cell failure in type 2 diabetes. Recently, we demonstrated that antioxidants reduced islet fibrosis in an animal model of type 2 diabetes. However, there is no in vitro study demonstrating that high glucose itself can induce oxidative stress in PSCs. Thus, PSCs were isolated and cultured from Sprague Dawley rats, and treated with high glucose for 72 h. High glucose increased the production of reactive oxygen species. When treated with high glucose, freshly isolated PSCs exhibited myofibroblastic transformation. During early culture (passage 1), PSCs treated with high glucose contained an increased number of α-smooth muscle actin-positive cells. During late culture (passages 2–5), PSCs treated with high glucose exhibited increases in cell proliferation, the expression of fibronectin and connective tissue growth factor, release of interleukin-6, transforming growth factor-β and collagen, and cell migration. Finally, the treatment of PSCs with high glucose and antioxidants attenuated these changes. In conclusion, we demonstrated that high glucose increased oxidative stress in primary rat PSCs, thereby facilitating the activation of these cells, while antioxidant treatment attenuated high glucose-induced PSC activation

  9. Classical Mus musculus Igκ enhancers support transcription but not high level somatic hypermutation from a V-lambda promoter in chicken DT40 cells.

    Directory of Open Access Journals (Sweden)

    Naga Rama Kothapalli

    2011-04-01

    Full Text Available Somatic hypermutation (SHM of immunoglobulin genes is initiated by activation-induced cytidine deaminase (AID in activated B cells. This process is strictly dependent on transcription. Hence, cis-acting transcriptional control elements have been proposed to target SHM to immunoglobulin loci. The Mus musculus Igκ locus is regulated by the intronic enhancer (iE/MAR and the 3' enhancer (3'E, and multiple studies using transgenic and knock-out approaches in mice and cell lines have reported somewhat contradictory results about the function of these enhancers in AID-mediated sequence diversification. Here we show that the M. musculus iE/MAR and 3'E elements are active solely as transcriptional enhancer when placed in the context of the IGL locus in Gallus gallus DT40 cells, but they are very inefficient in targeting AID-mediated mutation events to this locus. This suggests that either key components of the cis-regulatory targeting elements reside outside the murine Igκ transcriptional enhancer sequences, or that the targeting of AID activity to Ig loci occurs by largely species-specific mechanisms.

  10. Nicotinamide Inhibits Ethanol-Induced Caspase-3 and PARP-1 Over-activation and Subsequent Neurodegeneration in the Developing Mouse Cerebellum.

    Science.gov (United States)

    Ieraci, Alessandro; Herrera, Daniel G

    2018-06-01

    Fetal alcohol spectrum disorder (FASD) is the principal preventable cause of mental retardation in the western countries resulting from alcohol exposure during pregnancy. Ethanol-induced massive neuronal cell death occurs mainly in immature neurons during the brain growth spurt period. The cerebellum is one of the brain areas that are most sensitive to ethanol neurotoxicity. Currently, there is no effective treatment that targets the causes of these disorders and efficient treatments to counteract or reverse FASD are desirable. In this study, we investigated the effects of nicotinamide on ethanol-induced neuronal cell death in the developing cerebellum. Subcutaneous administration of ethanol in postnatal 4-day-old mice induced an over-activation of caspase-3 and PARP-1 followed by a massive neurodegeneration in the developing cerebellum. Interestingly, treatment with nicotinamide, immediately or 2 h after ethanol exposure, diminished caspase-3 and PARP-1 over-activation and reduced ethanol-induced neurodegeneration. Conversely, treatment with 3-aminobenzadine, a specific PARP-1 inhibitor, was able to completely block PARP-1 activation, but not caspase-3 activation or ethanol-induced neurodegeneration in the developing cerebellum. Our results showed that nicotinamide reduces ethanol-induced neuronal cell death and inhibits both caspase-3 and PARP-1 alcohol-induced activation in the developing cerebellum, suggesting that nicotinamide might be a promising and safe neuroprotective agent for treating FASD and other neurodegenerative disorders in the developing brain that shares similar cell death pathways.

  11. Effect of crowding, temperature and age on glia activation and dopaminergic neurotoxicity induced by MDMA in the mouse brain.

    Science.gov (United States)

    Frau, Lucia; Simola, Nicola; Porceddu, Pier Francesca; Morelli, Micaela

    2016-09-01

    3,4-methylenedyoxymethamphetamine (MDMA or "ecstasy"), a recreational drug of abuse, can induce glia activation and dopaminergic neurotoxicity. Since MDMA is often consumed in crowded environments featuring high temperatures, we studied how these factors influenced glia activation and dopaminergic neurotoxicity induced by MDMA. C57BL/6J adolescent (4 weeks old) and adult (12 weeks old) mice received MDMA (4×20mg/kg) in different conditions: 1) while kept 1, 5, or 10×cage at room temperature (21°C); 2) while kept 5×cage at either room (21°C) or high (27°C) temperature. After the last MDMA administration, immunohistochemistry was performed in the caudate-putamen for CD11b and GFAP, to mark microglia and astroglia, and in the substantia nigra pars compacta for tyrosine hydroxylase, to mark dopaminergic neurons. MDMA induced glia activation and dopaminergic neurotoxicity, compared with vehicle administration. Crowding (5 or 10 mice×cage) amplified MDMA-induced glia activation (in adult and adolescent mice) and dopaminergic neurotoxicity (in adolescent mice). Conversely, exposure to a high environmental temperature (27°C) potentiated MDMA-induced glia activation in adult and adolescent mice kept 5×cage, but not dopaminergic neurotoxicity. Crowding and exposure to a high environmental temperature amplified MDMA-induced hyperthermia, and a positive correlation between body temperature and activation of either microglia or astroglia was found in adult and adolescent mice. These results provide further evidence that the administration setting influences the noxious effects of MDMA in the mouse brain. However, while crowding amplifies both glia activation and dopaminergic neurotoxicity, a high environmental temperature exacerbates glia activation only. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Intestinal handling-induced mast cell activation and inflammation in human postoperative ileus

    NARCIS (Netherlands)

    The, F. O.; Bennink, R. J.; Ankum, W. M.; Buist, M. R.; Busch, O. R. C.; Gouma, D. J.; van der Heide, S.; van den Wijngaard, R. M.; de Jonge, W. J.; Boeckxstaens, G. E.

    2008-01-01

    Background: Murine postoperative ileus results from intestinal inflammation triggered by manipulation-induced mast cell activation. As its extent depends on the degree of handling and subsequent inflammation, it is hypothesised that the faster recovery after minimal invasive surgery results from

  13. Intestinal handling-induced mast cell activation and inflammation in human postoperative ileus

    NARCIS (Netherlands)

    The, F. O.; Bennink, R. J.; Ankum, W. M.; Buist, M. R.; Busch, O. R. C.; Gouma, D. J.; Van der Heide, S.; van den Wijngaard, R. M.; Boeckxstaens, G. E.; de Jonge, Wouter J.

    Background: Murine postoperative ileus results from intestinal inflammation triggered by manipulation-induced mast cell activation. As its extent depends on the degree of handling and subsequent inflammation, it is hypothesised that the faster recovery after minimal invasive surgery results from

  14. Particulate air pollution induces arrhythmia via oxidative stress and calcium calmodulin kinase II activation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin-Bae [The Division of Cardiology, Kyung Hee University College of Medicine, 1 Hoegi-dong, Dongdaemun-Gu, Seoul (Korea, Republic of); Kim, Changsoo [The Department of Preventive Medicine, Yonsei University College of Medicine, 250 Seungsanno, Seodaemun-gu, Seoul (Korea, Republic of); Choi, Eunmi [Cardiovascular Research Institute and Severance Biomedical Science Institute, Yonsei University College of Medicine, 250 Seungsanno, Seodaemun-gu, Seoul (Korea, Republic of); Park, Sanghoon; Park, Hyelim; Pak, Hui-Nam; Lee, Moon-Hyoung [The Division of Cardiology, Yonsei University College of Medicine, 250 Seungsanno, Seodaemun-gu, Seoul (Korea, Republic of); Shin, Dong Chun [The Department of Preventive Medicine, Yonsei University College of Medicine, 250 Seungsanno, Seodaemun-gu, Seoul (Korea, Republic of); Hwang, Ki-Chul [Cardiovascular Research Institute and Severance Biomedical Science Institute, Yonsei University College of Medicine, 250 Seungsanno, Seodaemun-gu, Seoul (Korea, Republic of); The Division of Cardiology, Yonsei University College of Medicine, 250 Seungsanno, Seodaemun-gu, Seoul (Korea, Republic of); Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, 250 Seungsanno, Seodaemun-gu, Seoul (Korea, Republic of); Joung, Boyoung, E-mail: cby6908@yuhs.ac [The Division of Cardiology, Yonsei University College of Medicine, 250 Seungsanno, Seodaemun-gu, Seoul (Korea, Republic of)

    2012-02-15

    Ambient particulate matter (PM) can increase the incidence of arrhythmia. However, the arrhythmogenic mechanism of PM is poorly understood. This study investigated the arrhythmogenic mechanism of PM. In Sprague–Dawley rats, QT interval was increased from 115.0 ± 14.0 to 142.1 ± 18.4 ms (p = 0.02) after endotracheal exposure of DEP (200 μg/ml for 30 min, n = 5). Ventricular premature contractions were more frequently observed after DEP exposure (100%) than baseline (20%, p = 0.04). These effects were prevented by pretreatment of N-acetylcysteine (NAC, 5 mmol/L, n = 3). In 12 Langendorff-perfused rat hearts, DEP infusion of 12.5 μg/ml for 20 min prolonged action potential duration (APD) at only left ventricular base increasing apicobasal repolarization gradients. Spontaneous early afterdepolarization (EAD) and ventricular tachycardia (VT) were observed in 8 (67%) and 6 (50%) hearts, respectively, versus no spontaneous triggered activity or VT in any hearts before DEP infusion. DEP-induced APD prolongation, EAD and VT were successfully prevented with NAC (5 mmol/L, n = 5), nifedipine (10 μmol/L, n = 5), and active Ca{sup 2+}/calmodulin-dependent protein kinase II (CaMKII) blockade, KN 93 (1 μmol/L, n = 5), but not by thapsigargin (200 nmol/L) plus ryanodine (10 μmol/L, n = 5) and inactive CaMKII blockade, KN 92 (1 μmol/L, n = 5). In neonatal rat cardiomyocytes, DEP provoked ROS generation in dose dependant manner. DEP (12.5 μg/ml) induced apoptosis, and this effect was prevented by NAC and KN 93. Thus, this study shows that in vivo and vitro exposure of PM induced APD prolongation, EAD and ventricular arrhythmia. These effects might be caused by oxidative stress and CaMKII activation. -- Highlights: ► The ambient PM consistently prolonged repolarization. ► The ambient PM induced triggered activity and ventricular arrhythmia. ► These effects were prevented by antioxidants, I{sub CaL} blockade and CaMKII blockade. ► The ambient PM can induce

  15. Secreted Immunomodulatory Proteins of Staphylococcus aureus Activate Platelets and Induce Platelet Aggregation.

    Science.gov (United States)

    Binsker, Ulrike; Palankar, Raghavendra; Wesche, Jan; Kohler, Thomas P; Prucha, Josephine; Burchhardt, Gerhard; Rohde, Manfred; Schmidt, Frank; Bröker, Barbara M; Mamat, Uwe; Pané-Farré, Jan; Graf, Anica; Ebner, Patrick; Greinacher, Andreas; Hammerschmidt, Sven

    2018-04-01

    Staphylococcus aureus can cause bloodstream infections associated with infective endocarditis (IE) and disseminated intravascular coagulopathy (DIC). Both complications involve platelets. In view of an increasing number of antibiotic-resistant strains, new approaches to control systemic S. aureus infection are gaining importance. Using a repertoire of 52 recombinant S. aureus proteins in flow cytometry-based platelet activation and aggregation assays, we identified, in addition to the extracellular adherence protein Eap, three secreted staphylococcal proteins as novel platelet activating proteins. Eap and the chemotaxis inhibitory protein of S. aureus (CHIPS), the formyl peptide receptor-like 1 inhibitory protein (FLIPr) and the major autolysin Atl induced P-selectin expression in washed platelets and platelet-rich plasma. Similarly, AtlA, CHIPS and Eap induced platelet aggregation in whole blood. Fluorescence microscopy illustrated that P-selectin expression is associated with calcium mobilization and re-organization of the platelet actin cytoskeleton. Characterization of the functionally active domains of the major autolysin AtlA and Eap indicates that the amidase domain of Atl and the tandem repeats 3 and 4 of Eap are crucial for platelet activation. These results provide new insights in S. aureus protein interactions with platelets and identify secreted proteins as potential treatment targets in case of antibiotic-resistant S. aureus infection. Schattauer GmbH Stuttgart.

  16. Exercise training attenuates sympathetic activation and oxidative stress in diet-induced obesity.

    Science.gov (United States)

    Li, G; Liu, J-Y; Zhang, H-X; Li, Q; Zhang, S-W

    2015-01-01

    It is known that excessive sympathetic activity and oxidative stress are enhanced in obesity. This study aimed to clarify whether exercise training (ET) attenuates sympathetic activation and oxidative stress in obesity. The obesity was induced by high-fat diet (HFD) for 12 weeks. Male Sprague-Dawley rats were assigned to four groups: regular diet (RD) plus sedentary (RD-S), RD plus ET (RD-ET), HFD plus sedentary (HFD-S), and HFD plus ET (HFD-ET). The rats in RD-ET and HFD-ET groups were trained on a motorized treadmill for 60 min/day, five days/week for 8 weeks. The sympathetic activity was evaluated by the plasma norepinephrine (NE) level. The superoxide anion, malondialdehyde and F2-isoprostanes levels in serum and muscles were measured to evaluate oxidative stress. The ET prevented the increases in the body weight, arterial pressure and white adipose tissue mass in HFD rats. The NE level in plasma and oxidative stress related parameters got lower in HFD-ET group compared with HFD-S group. We have found decreased mRNA and protein levels of toll-like receptor (TLR)-2 and TLR-4 by ET in HFD rats. These findings suggest that ET may be effective for attenuating sympathetic activation and oxidative stress in diet-induced obesity.

  17. Effect of biologically active fraction of Nardostachys jatamansi on cerulein-induced acute pancreatitis

    Science.gov (United States)

    Bae, Gi-Sang; Kim, Min-Sun; Park, Kyoung-Chel; Koo, Bon Soon; Jo, Il-Joo; Choi, Sun Bok; Lee, Dong-Sung; Kim, Youn-Chul; Kim, Tae-Hyeon; Seo, Sang-Wan; Shin, Yong Kook; Song, Ho-Joon; Park, Sung-Joo

    2012-01-01

    AIM: To determine if the fraction of Nardostachys jatamansi (NJ) has the potential to ameliorate the severity of acute pancreatitis (AP). METHODS: Mice were administered the biologically active fraction of NJ, i.e., the 4th fraction (NJ4), intraperitoneally, and then injected with the stable cholecystokinin analogue cerulein hourly for 6 h. Six hours after the last cerulein injection, the pancreas, lung, and blood were harvested for morphological examination, measurement of cytokine expression, and examination of neutrophil infiltration. RESULTS: NJ4 administration attenuated the severity of AP and lung injury associated with AP. It also reduced cytokine production and neutrophil infiltration and resulted in the in vivo up-regulation of heme oxygenase-1 (HO-1). Furthermore, NJ4 and its biologically active fraction, NJ4-2 inhibited the cerulein-induced death of acinar cells by inducing HO-1 in isolated pancreatic acinar cells. CONCLUSION: These results suggest that NJ4 may be a candidate fraction offering protection in AP and NJ4 might ameliorate the severity of pancreatitis by inducing HO-1 expression. PMID:22783046

  18. Autophagy activation is involved in 3,4-methylenedioxymethamphetamine ('ecstasy'--induced neurotoxicity in cultured cortical neurons.

    Directory of Open Access Journals (Sweden)

    I-Hsun Li

    Full Text Available Autophagic (type II cell death, characterized by the massive accumulation of autophagic vacuoles in the cytoplasm of cells, has been suggested to play pathogenetic roles in cerebral ischemia, brain trauma, and neurodegenerative disorders. 3,4-Methylenedioxymethamphetamine (MDMA or ecstasy is an illicit drug causing long-term neurotoxicity in the brain. Apoptotic (type I and necrotic (type III cell death have been implicated in MDMA-induced neurotoxicity, while the role of autophagy in MDMA-elicited neurotoxicity has not been investigated. The present study aimed to evaluate the occurrence and contribution of autophagy to neurotoxicity in cultured rat cortical neurons challenged with MDMA. Autophagy activation was monitored by expression of microtubule-associated protein 1 light chain 3 (LC3; an autophagic marker using immunofluorescence and western blot analysis. Here, we demonstrate that MDMA exposure induced monodansylcadaverine (MDC- and LC3B-densely stained autophagosome formation and increased conversion of LC3B-I to LC3B-II, coinciding with the neurodegenerative phase of MDMA challenge. Autophagy inhibitor 3-methyladenine (3-MA pretreatment significantly attenuated MDMA-induced autophagosome accumulation, LC3B-II expression, and ameliorated MDMA-triggered neurite damage and neuronal death. In contrast, enhanced autophagy flux by rapamycin or impaired autophagosome clearance by bafilomycin A1 led to more autophagosome accumulation in neurons and aggravated neurite degeneration, indicating that excessive autophagosome accumulation contributes to MDMA-induced neurotoxicity. Furthermore, MDMA induced phosphorylation of AMP-activated protein kinase (AMPK and its downstream unc-51-like kinase 1 (ULK1, suggesting the AMPK/ULK1 signaling pathway might be involved in MDMA-induced autophagy activation.

  19. Investigation of electrically-active deep levels in single-crystalline diamond by particle-induced charge transient spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kada, W., E-mail: kada.wataru@gunma-u.ac.jp [Faculty of Science and Technology, Gunma University, Kiryu, Gunma 376-8515 (Japan); Kambayashi, Y.; Ando, Y. [Faculty of Science and Technology, Gunma University, Kiryu, Gunma 376-8515 (Japan); Japan Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan); Onoda, S. [Japan Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan); Umezawa, H.; Mokuno, Y. [National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577 (Japan); Shikata, S. [Kwansei Gakuin Univ., 2-1, Gakuen, Mita, Hyogo 669-1337 (Japan); Makino, T.; Koka, M. [Japan Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan); Hanaizumi, O. [Faculty of Science and Technology, Gunma University, Kiryu, Gunma 376-8515 (Japan); Kamiya, T.; Ohshima, T. [Japan Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan)

    2016-04-01

    To investigate electrically-active deep levels in high-resistivity single-crystalline diamond, particle-induced charge transient spectroscopy (QTS) techniques were performed using 5.5 MeV alpha particles and 9 MeV carbon focused microprobes. For unintentionally-doped (UID) chemical vapor deposition (CVD) diamond, deep levels with activation energies of 0.35 eV and 0.43 eV were detected which correspond to the activation energy of boron acceptors in diamond. The results suggested that alpha particle and heavy ion induced QTS techniques are the promising candidate for in-situ investigation of deep levels in high-resistivity semiconductors.

  20. ERK inhibition sensitizes CZ415-induced anti-osteosarcoma activity in vitro and in vivo.

    Science.gov (United States)

    Yin, Gang; Fan, Jin; Zhou, Wei; Ding, Qingfeng; Zhang, Jun; Wu, Xuan; Tang, Pengyu; Zhou, Hao; Wan, Bowen; Yin, Guoyong

    2017-10-10

    mTOR is a valuable oncotarget for osteosarcoma. The anti-osteosarcoma activity by a novel mTOR kinase inhibitor, CZ415, was evaluated. We demonstrated that CZ415 potently inhibited survival and proliferation of known osteosarcoma cell lines (U2OS, MG-63 and SaOs2), and primary human osteosarcoma cells. Further, CZ415 provoked apoptosis and disrupted cell cycle progression in osteosarcoma cells. CZ415 treatment in osteosarcoma cells concurrently blocked mTORC1 and mTORC2 activation. Intriguingly, ERK-MAPK activation could be a major resistance factor of CZ415. ERK inhibition (by MEK162/U0126) or knockdown (by targeted ERK1/2 shRNAs) dramatically sensitized CZ415-induced osteosarcoma cell apoptosis. In vivo , CZ415 oral administration efficiently inhibited U2OS tumor growth in mice. Its activity was further potentiated with co-administration of MEK162. Collectively, we demonstrate that ERK inhibition sensitizes CZ415-induced anti-osteosarcoma activity in vitro and in vivo . CZ415 could be further tested as a promising anti-osteosarcoma agent, alone or in combination of ERK inhibition.

  1. Prunella vulgaris Suppresses HG-Induced Vascular Inflammation via Nrf2/HO-1/eNOS Activation

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    Ho Sub Lee

    2012-01-01

    Full Text Available Vascular inflammation is an important factor which can promote diabetic complications. In this study, the inhibitory effects of aqueous extract from Prunella vulgaris (APV on high glucose (HG-induced expression of cell adhesion molecules in human umbilical vein endothelial cells (HUVEC are reported. APV decreased HG-induced expression of intercellular adhesion molecule-1 (ICAM-1, vascular cell adhesion molecule-1 (VCAM-1, and E-selectin. APV also dose-dependently inhibited HG-induced adhesion of HL-60 monocytic cells. APV suppressed p65 NF-κB activation in HG-treated cells. APV significantly inhibited the formation of intracellular reactive oxygen species (ROS. HG-stimulated HUVEC secreted gelatinases, however, APV inhibited it. APV induced Akt phosphorylation as well as activation of heme oxygenase-1 (HO-1, eNOS, and nuclear factor E2-related factor 2 (Nrf2, which may protect vascular inflammation caused by HG. In conclusion, APV exerts anti-inflammatory effect via inhibition of ROS/NF-κB pathway by inducing HO-1 and eNOS expression mediated by Nrf2, thereby suggesting that Prunella vulgaris may be a possible therapeutic approach to the inhibition of diabetic vascular diseases.

  2. Holotoxin A1 Induces Apoptosis by Activating Acid Sphingomyelinase and Neutral Sphingomyelinase in K562 and Human Primary Leukemia Cells

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    Seong-Hoon Yun

    2018-04-01

    Full Text Available Marine triterpene glycosides are attractive candidates for the development of anticancer agents. Holotoxin A1 is a triterpene glycoside found in the edible sea cucumber, Apostichopus (Stichopus japonicus. We previously showed that cladoloside C2, the 25(26-dihydro derivative of holotoxin A1, induced apoptosis in human leukemia cells by activating ceramide synthase 6. Thus, we hypothesized that holotoxin A1, which is structurally similar to cladoloside C2, might induce apoptosis in human leukemia cells through the same molecular mechanism. In this paper, we compared holotoxin A1 and cladoloside C2 for killing potency and mechanism of action. We found that holotoxin A1 induced apoptosis more potently than cladoloside C2. Moreover, holotoxin A1 induced apoptosis in K562 cells by activating caspase-8 and caspase-3, but not by activating caspase-9. During holotoxin A1-induced apoptosis, acid sphingomyelinase (SMase and neutral SMase were activated in both K562 cells and human primary leukemia cells. Specifically inhibiting acid SMase and neutral SMаse with chemical inhibitors or siRNAs significantly inhibited holotoxin A1–induced apoptosis. These results indicated that holotoxin A1 might induce apoptosis by activating acid SMase and neutral SMase. In conclusion, holotoxin A1 represents a potential anticancer agent for treating leukemia. Moreover, the aglycone structure of marine triterpene glycosides might affect the mechanism involved in inducing apoptosis.

  3. Low-Dose Ribavirin Treatments Attenuate Neuroinflammatory Activation of BV-2 Cells by Interfering with Inducible Nitric Oxide Synthase

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    Iva Bozic

    2015-01-01

    Full Text Available Microglia play a key role in defending central nervous system from various internal and external threats. However, their excessive and/or chronic activation is associated with deleterious effects in a variety of neurodegenerative diseases. Previously, we have shown that ribavirin when applied in clinically relevant dosage (10 μM modulates activated microglia in complex fashion inducing both anti- and proinflammatory effects, simultaneously causing cytotoxicity. Here, we examined potential of low-dose ribavirin (0.1 and 1 μM to modulate activated BV-2 microglia. Morphological and functional activation of BV-2 cells was achieved with lipopolysaccharide (LPS stimulation. Our results demonstrated that low-dose ribavirin did not induce cell death, while 10 μM ribavirin promoted LPS induced apoptosis. We determined that 1 μM ribavirin was equally efficient in deactivation of LPS induced morphological changes as 10 μM ribavirin treatment. Ribavirin showed halfway success in reducing markers of functional activation of microglia. Namely, none of the doses had effect on LPS triggered production of proinflammatory cytokine tumor necrosis factor alpha. On the other hand, low-dose ribavirin proved its effectiveness in reduction of another inflammatory mediator, nitric oxide, by inhibiting inducible form of nitric oxide synthase. Our results imply that low-dose ribavirin may alleviate nitrosative stress during neuroinflammation.

  4. Low-Dose Ribavirin Treatments Attenuate Neuroinflammatory Activation of BV-2 Cells by Interfering with Inducible Nitric Oxide Synthase

    Science.gov (United States)

    Bozic, Iva; Savic, Danijela; Jovanovic, Marija; Bjelobaba, Ivana; Laketa, Danijela; Nedeljkovic, Nadezda; Stojiljkovic, Mirjana; Pekovic, Sanja; Lavrnja, Irena

    2015-01-01

    Microglia play a key role in defending central nervous system from various internal and external threats. However, their excessive and/or chronic activation is associated with deleterious effects in a variety of neurodegenerative diseases. Previously, we have shown that ribavirin when applied in clinically relevant dosage (10 μM) modulates activated microglia in complex fashion inducing both anti- and proinflammatory effects, simultaneously causing cytotoxicity. Here, we examined potential of low-dose ribavirin (0.1 and 1 μM) to modulate activated BV-2 microglia. Morphological and functional activation of BV-2 cells was achieved with lipopolysaccharide (LPS) stimulation. Our results demonstrated that low-dose ribavirin did not induce cell death, while 10 μM ribavirin promoted LPS induced apoptosis. We determined that 1 μM ribavirin was equally efficient in deactivation of LPS induced morphological changes as 10 μM ribavirin treatment. Ribavirin showed halfway success in reducing markers of functional activation of microglia. Namely, none of the doses had effect on LPS triggered production of proinflammatory cytokine tumor necrosis factor alpha. On the other hand, low-dose ribavirin proved its effectiveness in reduction of another inflammatory mediator, nitric oxide, by inhibiting inducible form of nitric oxide synthase. Our results imply that low-dose ribavirin may alleviate nitrosative stress during neuroinflammation. PMID:26413464

  5. Src is activated by the nuclear receptor peroxisome proliferator-activated receptor β/δ in ultraviolet radiation-induced skin cancer.

    Science.gov (United States)

    Montagner, Alexandra; Delgado, Maria B; Tallichet-Blanc, Corinne; Chan, Jeremy S K; Sng, Ming K; Mottaz, Hélén; Degueurce, Gwendoline; Lippi, Yannick; Moret, Catherine; Baruchet, Michael; Antsiferova, Maria; Werner, Sabine; Hohl, Daniel; Saati, Talal Al; Farmer, Pierre J; Tan, Nguan S; Michalik, Liliane; Wahli, Walter

    2014-01-01

    Although non-melanoma skin cancer (NMSC) is the most common human cancer and its incidence continues to rise worldwide, the mechanisms underlying its development remain incompletely understood. Here, we unveil a cascade of events involving peroxisome proliferator-activated receptor (PPAR) β/δ and the oncogene Src, which promotes the development of ultraviolet (UV)-induced skin cancer in mice. UV-induced PPARβ/δ activity, which directly stimulated Src expression, increased Src kinase activity and enhanced the EGFR/Erk1/2 signalling pathway, resulting in increased epithelial-to-mesenchymal transition (EMT) marker expression. Consistent with these observations, PPARβ/δ-null mice developed fewer and smaller skin tumours, and a PPARβ/δ antagonist prevented UV-dependent Src stimulation. Furthermore, the expression of PPARβ/δ positively correlated with the expression of SRC and EMT markers in human skin squamous cell carcinoma (SCC), and critically, linear models applied to several human epithelial cancers revealed an interaction between PPARβ/δ and SRC and TGFβ1 transcriptional levels. Taken together, these observations motivate the future evaluation of PPARβ/δ modulators to attenuate the development of several epithelial cancers.

  6. Usefulness of Basophil Activation Tests for Diagnosis of Sugammadex-Induced Anaphylaxis.

    Science.gov (United States)

    Horiuchi, Tatsuo; Yokohama, Akihiko; Orihara, Masaki; Tomita, Yukinari; Tomioka, Akihiro; Yoshida, Nagahide; Takahashi, Kenichiro; Saito, Shigeru; Takazawa, Tomonori

    2018-05-01

    Sugammadex is used to reverse the effects of neuromuscular blocking agents in many cases of general anesthesia. However, there are several reports of anaphylaxis after its use. Skin testing is the gold standard for detecting the causative agent of anaphylaxis. However, due to the lack of validated protocols for skin testing with sugammadex, the diagnostic accuracy might be inadequate. Recently, the basophil activation test (BAT) has been established as a tool to detect the causative agent of anaphylaxis with high sensitivity and specificity. However, few studies have investigated the utility of the BAT for sugammadex-induced anaphylaxis. Eight patients who presented with immediate hypersensitivity to sugammadex during general anesthesia were included in this study. We conducted skin tests to confirm the diagnosis of sugammadex-induced anaphylaxis. Twenty-one sugammadex-naive individuals who had a negative skin test for allergy to this drug were enrolled as controls. Basophils were selected on a CD3/CRTH2 gate and labeled with CD63 and CD203c. The ratios of activated basophils in the patients were much higher than those in controls: the median values of areas under the curves in the patients and controls for CD203c were 1,265,985 (95% confidence interval [CI], 77,580-5,040,270) and 116,325 (95% CI, -268,605 to 232,690), respectively (Mann-Whitney U test, P sugammadex was 88% (95% CI, 47%-100%), and specificity was 100% (95% CI, 84%-100%), while sensitivity and specificity for CD63 were 75% (95% CI, 35%-97%) and 100% (95% CI, 84%-100%), respectively. The BAT seems to have comparable accuracy to skin tests for the diagnosis of sugammadex-induced anaphylaxis. For this purpose, both CD203c and CD63 can be used to detect activated basophils.

  7. Technetium-99 conjugated with methylene diphosphonate inhibits receptor activator of nuclear factor-κB ligand-induced osteoclastogenesis.

    Science.gov (United States)

    Gong, Wei; Dou, Huan; Liu, Xianqin; Sun, Lingyun; Hou, Yayi

    2012-10-01

    1. In the present study, we investigated the effects of technetium-99 conjugated with methylene diphosphonate ((99)Tc-MDP), an agent used in radionuclide therapy, on receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclastogenesis and explored the underlying mechanisms. 2. The murine macrophage cell line RAW264.7 and bone marrow-derived-macrophages from C57BL/6 mice (BMM) were used as models for osteoclastogenesis in vitro. The expression of some key factors in RANKL (50 ng/mL)-induced osteoclastogenesis in RAW264.7 cells was investigated by flow cytometry and real-time reverse transcription-polymerase chain reaction (RT-PCR). To detect multinucleated osteoclast formation, RAW264.7 cells were induced with RANKL for 4 days, whereas BMM were induced by 50 ng/mL RANKL and 20 ng/mL macrophage colony-stimulating factor for 7 days, before being stained with tartrate-resistant acid phosphatase. 3. Osteoclastogenesis was evaluated using the osteoclast markers CD51, matrix metalloproteinase (MMP)-9 and cathepsin K. At 0.01 μg/mL, (99)Tc-MDP significantly inhibited RANKL-induced osteoclastogenesis without any cytotoxicity. In addition, (99)Tc-MDP abolished the appearance of multinucleated osteoclasts. 4. Real-time RT-PCR analysis of transcription factor expression revealed that (99)Tc-MDP inhibited the expression of c-Fos and nuclear factor of activated T cells. In addition, (99)Tc-MDP inhibited the expression of the inflammatory factors interleukin (IL)-6, tumour necrosis factor-α and IL-1β. Finally, (99)Tc-MDP inhibited the activation of mitogen-activated protein kinases in RAW264.7 cells following RANKL stimulation. 5. In conclusion, (99)Tc-MDP possesses anti-osteoclastogenic activity against RANKL-induced osteoclast formation. © 2012 The Authors Clinical and Experimental Pharmacology and Physiology © 2012 Wiley Publishing Asia Pty Ltd.

  8. Enhanced neutrophil chemotactic activity after bronchial challenge in subjects with grain dust-induced asthma.

    Science.gov (United States)

    Park, H S; Jung, K S

    1998-03-01

    There have been few reports suggesting involvement of neutrophils in induction of bronchoconstriction after inhalation of grain dust. To understand the role of neutrophils in pathogenesis of grain dust-induced asthma. We observed serum neutrophil chemotactic activity during grain dust-bronchoprovocation tests in six asthmatic subjects with positive bronchial challenges (group I). They were compared with those of six symptomatic subjects from the same workplace with negative bronchial challenges (group II). After grain dust inhalation, serum neutrophil chemotactic activity significantly increased at 30 minutes (P = .028), and then decreased to baseline level at 240 minutes (P = .028) in five subjects of group I having isolated early asthmatic responses. Enhanced neutrophil chemotactic activity was persistent for up to 240 minutes in one asthmatic subject having both early and late asthmatic responses. There was, however, no significant change in serum neutrophil chemotactic activity during bronchial challenges in subjects of group II. Pre-incubation of sera with anti-interleukin-8 (IL-8) antibody did not affect the neutrophil chemotactic activity results of group I subjects. These results suggest that enhanced neutrophil chemotactic activity distinct from IL-8 may contribute to significant bronchoconstriction induced by grain dust.

  9. Cannabinoid-Induced Changes in the Activity of Electron Transport Chain Complexes of Brain Mitochondria.

    Science.gov (United States)

    Singh, Namrata; Hroudová, Jana; Fišar, Zdeněk

    2015-08-01

    The aim of this study was to investigate changes in the activity of individual mitochondrial respiratory chain complexes (I, II/III, IV) and citrate synthase induced by pharmacologically different cannabinoids. In vitro effects of selected cannabinoids on mitochondrial enzymes were measured in crude mitochondrial fraction isolated from pig brain. Both cannabinoid receptor agonists, Δ(9)-tetrahydrocannabinol, anandamide, and R-(+)-WIN55,212-2, and antagonist/inverse agonists of cannabinoid receptors, AM251, and cannabidiol were examined in pig brain mitochondria. Different effects of these cannabinoids on mitochondrial respiratory chain complexes and citrate synthase were found. Citrate synthase activity was decreased only by Δ(9)-tetrahydrocannabinol and AM251. Significant increase in the complex I activity was induced by anandamide. At micromolar concentration, all the tested cannabinoids inhibited the activity of electron transport chain complexes II/III and IV. Stimulatory effect of anandamide on activity of complex I may participate on distinct physiological effects of endocannabinoids compared to phytocannabinoids or synthetic cannabinoids. Common inhibitory effect of cannabinoids on activity of complex II/III and IV confirmed a non-receptor-mediated mechanism of cannabinoid action on individual components of system of oxidative phosphorylation.

  10. DNA Methylation Dynamics of Germinal Center B Cells Are Mediated by AID

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    Pilar M. Dominguez

    2015-09-01

    Full Text Available Changes in DNA methylation are required for the formation of germinal centers (GCs, but the mechanisms of such changes are poorly understood. Activation-induced cytidine deaminase (AID has been recently implicated in DNA demethylation through its deaminase activity coupled with DNA repair. We investigated the epigenetic function of AID in vivo in germinal center B cells (GCBs isolated from wild-type (WT and AID-deficient (Aicda−/− mice. We determined that the transit of B cells through the GC is associated with marked locus-specific loss of methylation and increased methylation diversity, both of which are lost in Aicda−/− animals. Differentially methylated cytosines (DMCs between GCBs and naive B cells (NBs are enriched in genes that are targeted for somatic hypermutation (SHM by AID, and these genes form networks required for B cell development and proliferation. Finally, we observed significant conservation of AID-dependent epigenetic reprogramming between mouse and human B cells.

  11. Sulforaphane Prevents Angiotensin II-Induced Testicular Cell Death via Activation of NRF2

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    Yonggang Wang

    2017-01-01

    Full Text Available Although angiotensin II (Ang II was reported to facilitate sperm motility and intratesticular sperm transport, recent findings shed light on the efficacy of Ang II in stimulating inflammatory events in testicular peritubular cells, effect of which may play a role in male infertility. It is still unknown whether Ang II can induce testicular apoptotic cell death, which may be a more direct action of Ang II in male infertility. Therefore, the present study aims to determine whether Ang II can induce testicular apoptotic cell death and whether this action can be prevented by sulforaphane (SFN via activating nuclear factor (erythroid-derived 2-like 2 (NRF2, the governor of antioxidant-redox signalling. Eight-week-old male C57BL/6J wild type (WT and Nrf2 gene knockout mice were treated with Ang II, in the presence or absence of SFN. In WT mice, SFN activated testicular NRF2 expression and function, along with a marked attenuation in Ang II-induced testicular oxidative stress, inflammation, endoplasmic reticulum stress, and apoptotic cell death. Deletion of the Nrf2 gene led to a complete abolishment of these efficacies of SFN. The present study indicated that Ang II may result in testicular apoptotic cell death, which can be prevented by SFN via the activation of NRF2.

  12. PKCθ is required for the activation of human T lymphocytes induced by CD43 engagement

    International Nuclear Information System (INIS)

    Rio, Roxana del; Rincon, Mercedes; Layseca-Espinosa, Esther; Fierro, Nora A.; Rosenstein, Yvonne; Pedraza-Alva, Gustavo

    2004-01-01

    The turnover of phosphoinositides leading to PKC activation constitutes one of the principal axes of intracellular signaling. In T lymphocytes, the enhanced and prolonged PKC activation resulting from the engagement of the TcR and co-receptor molecules ensures a productive T cell response. The CD43 co-receptor promotes activation and proliferation, by inducing IL-2 secretion and CD69 expression. CD43 engagement has been shown to promote phosphoinositide turnover and DAG production. Moreover, PKC activation was found to be required for the activation of the MAP kinase pathway in response to CD43 ligation. Here we show that CD43 engagement led to the membrane translocation and enzymatic activity of specific PKC isoenzymes: cPKC (α/β), nPKC (ε and θ), aPKC (ζ) and PKCμ. We also show that activation of PKCθ resulting from CD43 ligation induced CD69 expression through an ERK-dependent pathway leading to AP-1, NF-κB activation and an ERK independent pathway promoting NFAT activation. Together, these data suggest that PKCθ plays a critical role in the co-stimulatory functions of CD43 in human T cells

  13. Cisplatin Induces Cytotoxicity through the Mitogen-Activated Protein Kinase Pathways ana Activating Transcription Factor 3

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    Carly St. Germain

    2010-07-01

    Full Text Available The mechanisms underlying the proapoptotic effect of the chemotherapeutic agent, cisplatin, are largely undefined. Understanding the mechanisms regulating cisplatin cytotoxicity may uncover strategies to enhance the efficacy of this important therapeutic agent. This study evaluates the role of activating transcription factor 3 (ATF3 as a mediator of cisplatin-induced cytotoxicity. Cytotoxic doses of cisplatin and carboplatin treatments consistently induced ATF3 expression in five tumor-derived cell lines. Characterization of this induction revealed a p53, BRCA1, and integrated stress response-independent mechanism, all previously implicated in stress-mediated ATF3 induction. Analysis of mitogenactivated protein kinase (MAPK pathway involvement in ATF3 induction by cisplatin revealed a MAPK-dependent mechanism. Cisplatin treatment combined with specific inhibitors to each MAPK pathway (c-Jun N-terminal kinase, extracellularsignal-regulated kinase, and p38 resulted in decreasedATF3 induction at the protein level. MAPK pathway inhibition led to decreased ATF3 messenger RNA expression and reduced cytotoxic effects of cisplatin as measured by the 3-(4,5-dimethylthiazol-2-ylF2,5-diphenyltetrazolium bromide cell viability assay. In A549 lung carcinoma cells, targeting ATF3 with specific small hairpin RNA also attenuated the cytotoxic effects of cisplatin. Similarly, ATF3-/murine embryonic fibroblasts (MEFs were shown to be less sensitive to cisplatin-induced cytotoxicity compared with ATF3+/+ MEFs. This study identifies cisplatin as a MAPK pathway-dependent inducer of ATF3, whose expression influences cisplatin’s cytotoxic effects.

  14. The Synthetic Lignan Secoisolariciresinol Diglucoside Prevents Asbestos-Induced NLRP3 Inflammasome Activation in Murine Macrophages

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    Ralph A. Pietrofesa

    2017-01-01

    Full Text Available Background. The interaction of asbestos with macrophages drives two key processes that are linked to malignancy: (1 the generation of reactive oxygen species (ROS/reactive nitrogen species (RNS and (2 the activation of an inflammation cascade that drives acute and chronic inflammation, with the NLRP3 inflammasome playing a key role. Synthetic secoisolariciresinol diglucoside (SDG, LGM2605, is a nontoxic lignan with anti-inflammatory and antioxidant properties and was evaluated for protection from asbestos in murine peritoneal macrophages (MF. Methods. MFs were exposed to crocidolite asbestos ± LGM2605 given 4 hours prior to exposure and evaluated at various times for NLRP3 expression, secretion of inflammasome-activated cytokines (IL-1β and IL-18, proinflammatory cytokines (IL-6, TNFα, and HMGB1, NF-κB activation, and levels of total nitrates/nitrites. Results. Asbestos induces a significant (p<0.0001 increase in the NLRP3 subunit, release of proinflammatory cytokines, NLRP3-activated cytokines, NF-κB, and levels of nitrates/nitrites. LGM2605 significantly reduced NLRP3 ranging from 40 to 81%, IL-1β by 89–96%, and TNFα by 67–78%, as well as activated NF-κB by 48-49% while decreasing levels of nitrates/nitrites by 85–93%. Conclusions. LGM2605 reduced asbestos-induced NLRP3 expression, proinflammatory cytokine release, NF-κB activation, and nitrosative stress in MFs supporting its possible use in preventing the asbestos-induced inflammatory cascade leading to malignancy.

  15. Xanthohumol attenuates cisplatin-induced nephrotoxicity through inhibiting NF-κB and activating Nrf2 signaling pathways.

    Science.gov (United States)

    Li, Fan; Yao, Yunyi; Huang, Hui; Hao, Hua; Ying, Mingzhong

    2018-06-12

    Cisplatin is a chemotherapeutic agent that widely used in the treatment of cancer. However, cisplatin has been reported to induce nephrotoxicity by directly inducing inflammatory response and oxidative stress. In this study, we aimed to investigate the protective effects and mechanism of xanthohumol on cisplatin-induced nephrotoxicity. The model of nephrotoxicity was induced by intraperitoneal injection of cisplatin and xanthohumol was given intraperitoneally for three consecutive days. The results showed that xanthohumol significantly attenuated kidney histological changes and serum creatinine and BUN production. The levels of TNF-α, IL-1ß and IL-6 in kidney tissues were suppressed by xanthohumol. The levels of malondialdehyde (MDA) and ROS were suppressed by treatment of xanthohumol. The activities of glutathione (GSH) and superoxide dismutase (SOD) decreased by cisplatin were reversed by xanthohumol. Furthermore, the expression of TLR4 and the activation of NF-κB induced by cisplatin were significantly inhibited by xanthohumol. The expression of Nrf2 and HO-1 were dose-dependently up-regulated by the treatment of xanthohumol. In conclusion, xanthohumol protects against cisplatin-induced nephrotoxicity by ameliorating inflammatory and oxidative responses. Copyright © 2018 Elsevier B.V. All rights reserved.

  16. Chronic Fluoxetine Induces Activity Changes in Recovery From Poststroke Anxiety, Depression, and Cognitive Impairment.

    Science.gov (United States)

    Vahid-Ansari, Faranak; Albert, Paul R

    2018-01-01

    Poststroke depression (PSD) is a common outcome of stroke that limits recovery and is only partially responsive to chronic antidepressant treatment. In order to elucidate changes in the cortical-limbic circuitry associated with PSD and its treatment, we examined a novel mouse model of persistent PSD. Focal endothelin-1-induced ischemia of the left medial prefrontal cortex (mPFC) in male C57BL6 mice resulted in a chronic anxiety and depression phenotype. Here, we show severe cognitive impairment in spatial learning and memory in the stroke mice. The behavioral and cognitive phenotypes were reversed by chronic (4-week) treatment with fluoxetine, alone or with voluntary exercise (free-running wheel), but not by exercise alone. To assess chronic cellular activation, FosB + cells were co-labeled for markers of glutamate/pyramidal (VGluT1-3/CaMKIIα), γ-aminobutyric acid (GAD67), and serotonin (TPH). At 6 weeks poststroke versus sham (or 4 days poststroke), left mPFC stroke induced widespread FosB activation, more on the right (contralesional) than on the left side. Stroke activated glutamate cells of the mPFC, nucleus accumbens, amygdala, hippocampus, and raphe serotonin neurons. Chronic fluoxetine balanced bilateral neuronal activity, reducing total FosB and FosB/CamKII + cells (mPFC, nucleus accumbens), and unlike exercise, increasing FosB/GAD67 + cells (septum, amygdala) or both (hippocampus, raphe). In summary, chronic antidepressant but not exercise mediates recovery in this unilateral ischemic PSD model that is associated with region-specific reversal of stroke-induced pyramidal cell hyperactivity and increase in γ-aminobutyric acidergic activity. Targeted brain stimulation to restore brain activity could provide a rational approach for treating clinical PSD.

  17. Study of antihyperglycaemic activity of medicinal plant extracts in alloxan induced diabetic rats

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    Anoja P Attanayake

    2013-01-01

    C onclusion: The aqueous extract of G. arborea, S. pinnata, K. zeylanica, S. caryophyllatum, S. dulcis, S. alnifolia, L. galanga and C. grandis possess potent acute antihyperglycaemic activity in alloxan induced diabetic rats.

  18. Retinoic acid modulation of ultraviolet light-induced epidermal ornithine decarboxylase activity

    International Nuclear Information System (INIS)

    Lowe, N.J.; Breeding, J.

    1982-01-01

    Irradiation of skin with ultraviolet light of sunburn range (UVB) leads to a large and rapid induction of the polyamine biosynthetic enzyme ornithine decarboxylase in the epidermis. Induction of epidermal ornithine decarboxylase also occurs following application of the tumor promoting agent 12-0-tetradecanoylphorbol-13 acetate and topical retinoic acid is able to block both this ornithine decarboxylase induction and skin tumor promotion. In the studies described below, topical application of retinoic acid to hairless mouse skin leads to a significant inhibition of UVB-induced epidermal ornithine decarboxylase activity. The degree of this inhibition was dependent on the dose, timing, and frequency of the application of retinoic acid. To show significant inhibition of UVB-induced ornithine decarboxylase the retinoic acid had to be applied within 5 hr of UVB irradiation. If retinoic acid treatment was delayed beyond 7 hr following UVB, then no inhibition of UVB-induced ornithine decarboxylase was observed. The quantities of retinoic acid used (1.7 nmol and 3.4 nmol) have been shown effective at inhibiting 12-0-tetradecanoyl phorbol-13 acetate induced ornithine decarboxylase. The results show that these concentrations of topical retinoic acid applied either before or immediately following UVB irradiation reduces the UVB induction of epidermal ornithine decarboxylase. The effect of retinoic acid in these regimens on UVB-induced skin carcinogenesis is currently under study

  19. Staurosporine induces ganglion cell differentiation in part by stimulating urokinase-type plasminogen activator expression and activation in the developing chick retina

    International Nuclear Information System (INIS)

    Kim, Yeoun-Hee; Chang, Yongmin; Jung, Jae-Chang

    2012-01-01

    Highlights: ► Staurosporine mediates stimulation of RGC differentiation in vitro cultured retinal neuroblasts. ► Staurosporine mediates uPA activation during RGC differentiation in vitro. ► Inhibition of uPA blocks the staurosporine mediated RGC differentiation both in vitro and in ovo. ► Thus, uPA may play a role in the staurosporine-mediated stimulation of RGC differentiation. -- Abstract: Here, we investigated whether staurosporine-mediated urokinase-type plasminogen activator (uPA) activation is involved in retinal ganglion cell (RGC) differentiation. Retinal cells were isolated from developing chick retinas at embryonic day 6 (E6). Relatively few control cells grown in serum-free medium started to form processes by 12 h. In contrast, staurosporine-treated cells had processes within 3 h, and processes were evident at 8 h. Immunofluorescence staining showed that Tuj-1-positive cells with shorter neurites could be detected in control cultures at 18 h, whereas numerous Tuj-1 positive ganglion cells with longer neuritic extensions were seen in staurosporine-treated cultures. BrdU-positive proliferating cells were more numerous in control cultures than in staurosporine-treated cultures, and the BrdU staining was not detected in post-mitotic Tuj-1 positive ganglion cells. Western blotting of cell lysates showed that staurosporine induced high levels of the active form of uPA. The staurosporine-induced uPA signal was localized predominantly in the soma, neurites and axons of Tuj-1-positive ganglion cells. Amiloride, an inhibitor of uPA, markedly reduced staurosporine-induced Tuj-1 staining, neurite length, neurite number, and uPA staining versus controls. In developing retinas in ovo, amiloride administration remarkably reduced the staurosporine-induced uPA staining and RGC differentiation. Taken together, our in vitro and in vivo data collectively indicate that uPA plays a role in the staurosporine-mediated stimulation of RGC differentiation.

  20. Anticonvulsant activity of B2, an adenosine analog, on chemical convulsant-induced seizures.

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    Min Li

    Full Text Available Epilepsy is a chronic neurological disorder characterized by recurrent seizures. However, approximately one-third of epilepsy patients still suffer from uncontrolled seizures. Effective treatments for epilepsy are yet to be developed. N (6-(3-methoxyl-4-hydroxybenzyl adenine riboside (B2 is a N(6-substitued adenosine analog. Here we describe an investigation of the effects and mechanisms of B2 on chemical convulsant-induced seizures. Seizures were induced in mice by administration of 4-aminopyridine (4-AP, pentylenetetrazol (PTZ, picrotoxin, kainite acid (KA, or strychnine. B2 has a dose-related anticonvulsant effect in these chemical-induced seizure models. The protective effects of B2 include increased latency of seizure onset, decreased seizure occurrence, shorter seizure duration and reduced mortality rate. Radioligand binding and cAMP accumulation assays indicated that B2 might be a functional ligand for both adenosine A1 and A2A receptors. Furthermore, DPCPX, a selective A1 receptor antagonist, but not SCH58261, a selective A2A receptor antagonist, blocked the anticonvulsant effect of B2 on PTZ-induced seizure. c-Fos is a cellular marker for neuronal activity. Immunohistochemical and western blot analyses indicated that B2 significantly reversed PTZ-induced c-Fos expression in the hippocampus. Together, these results indicate that B2 has significant anticonvulsant effects. The anticonvulsant effects of B2 may be attributed to adenosine A1 receptor activation and reduced neuronal excitability in the hippocampus. These observations also support that the use of adenosine receptor agonist may be a promising approach for the treatment of epilepsy.

  1. Oral glucose ingestion attenuates exercise-induced activation of 5'-AMP-activated protein kinase in human skeletal muscle

    DEFF Research Database (Denmark)

    Åkerström, Thorbjörn; Birk, Jesper Bratz; Klein, Ditte Kjærsgaard

    2006-01-01

    5'-AMP-activated protein kinase (AMPK) has been suggested to be a 'metabolic master switch' regulating various aspects of muscle glucose and fat metabolism. In isolated rat skeletal muscle, glucose suppresses the activity of AMPK and in human muscle glycogen loading decreases exercise-induced AMPK...... activation. We hypothesized that oral glucose ingestion during exercise would attenuate muscle AMPK activation. Nine male subjects performed two bouts of one-legged knee-extensor exercise at 60% of maximal workload. The subjects were randomly assigned to either consume a glucose containing drink or a placebo...... drink during the two trials. Muscle biopsies were taken from the vastus lateralis before and after 2 h of exercise. Plasma glucose was higher (6.0 +/- 0.2 vs. 4.9 +/- 0.1 mmol L-1, P

  2. Hepatoprotective activity of aqueous methanolic extract of Morus nigra against paracetamol-induced hepatotoxicity in mice

    Directory of Open Access Journals (Sweden)

    Tauqeer Hussain Mallhi

    2014-03-01

    Full Text Available Morus nigra (Family Moraceae is traditionally used injaundice, diabetes, hypertension, cough, fever and cancer. The current study was conducted to determine hepatoprotective activity of aqueous methanolic extract of leaves of M. nigra. Two doses of 250 mg/kg p.o and 500 mg/kg p.o showed that extract of M. nigra produced significant (p<0.001 reduction in liver enzymes (ALT, AST, ALP and total bilirubin induced by paracetamol and the results are comparable to silymarin (p<0.001. Results were supported by histopathologi-cal investigations, phytochemical screening and detection of active consti-tuents by HPLC. The current study showed that aqueous methanolic extract of M. nigra possess hepatoprotective activity that might be due to quercetin, luteolin and isorhamnetin. It was concluded from this study that M. nigra has hepatoprotective activity against paracetamol induced liver injury in mice.

  3. CRISPR Epigenome Editing of AKAP150 in DRG Neurons Abolishes Degenerative IVD-Induced Neuronal Activation.

    Science.gov (United States)

    Stover, Joshua D; Farhang, Niloofar; Berrett, Kristofer C; Gertz, Jason; Lawrence, Brandon; Bowles, Robby D

    2017-09-06

    Back pain is a major contributor to disability and has significant socioeconomic impacts worldwide. The degenerative intervertebral disc (IVD) has been hypothesized to contribute to back pain, but a better understanding of the interactions between the degenerative IVD and nociceptive neurons innervating the disc and treatment strategies that directly target these interactions is needed to improve our understanding and treatment of back pain. We investigated degenerative IVD-induced changes to dorsal root ganglion (DRG) neuron activity and utilized CRISPR epigenome editing as a neuromodulation strategy. By exposing DRG neurons to degenerative IVD-conditioned media under both normal and pathological IVD pH levels, we demonstrate that degenerative IVDs trigger interleukin (IL)-6-induced increases in neuron activity to thermal stimuli, which is directly mediated by AKAP and enhanced by acidic pH. Utilizing this novel information on AKAP-mediated increases in nociceptive neuron activity, we developed lentiviral CRISPR epigenome editing vectors that modulate endogenous expression of AKAP150 by targeted promoter histone methylation. When delivered to DRG neurons, these epigenome-modifying vectors abolished degenerative IVD-induced DRG-elevated neuron activity while preserving non-pathologic neuron activity. This work elucidates the potential for CRISPR epigenome editing as a targeted gene-based pain neuromodulation strategy. Copyright © 2017 The American Society of Gene and Cell Therapy. Published by Elsevier Inc. All rights reserved.

  4. Integrated modulation of phorbol ester-induced Raf activation in EL4 lymphoma cells.

    Science.gov (United States)

    Han, Shujie; Meier, Kathryn E

    2009-05-01

    The EL4 murine lymphoma cell line exists in variant phenotypes that differ with respect to responses to the tumor promoter phorbol 12-myristate 13-acetate (PMA1). Previous work showed that "PMA-sensitive" cells, characterized by a high magnitude of PMA-induced Erk activation, express RasGRP, a phorbol ester receptor that directly activates Ras. In "PMA-resistant" and "intermediate" EL4 cell lines, PMA induces Erk activation to lesser extents, but with a greater response in intermediate cells. In the current study, these cell lines were used to examine mechanisms of Raf-1 modulation. Phospho-specific antibodies were utilized to define patterns and kinetics of Raf-1 phosphorylation on several sites. Further studies showed that Akt is constitutively activated to a greater extent in PMA-resistant than in PMA-sensitive cells, and also to a greater extent in resistant than intermediate cells. Akt negatively regulates Raf-1 activation (Ser259), partially explaining the difference between resistant and intermediate cells. Erk activation exerts negative feedback on Raf-1 (Ser289/296/301), thus resulting in earlier termination of the signal in cells with a higher level of Erk activation. RKIP, a Raf inhibitory protein, is expressed at higher levels in resistant cells than in sensitive or intermediate cells. Knockdown of RKIP increases Erk activation and also negative feedback. In conclusion, this study delineates Raf-1 phosphorylation events occurring in response to PMA in cell lines with different extents of Erk activation. Variations in the levels of expression and activation of multiple signaling proteins work in an integrated fashion to modulate the extent and duration of Erk activation.

  5. NF-kB activity-dependent P-selectin involved in ox-LDL-induced foam cell formation in U937 cell

    International Nuclear Information System (INIS)

    Wang, Yi; Wang, Xiang; Sun, Minghui; Zhang, Zhenyu; Cao, Heng; Chen, Xiaoqing

    2011-01-01

    Highlights: → Ox-LDL induced foam cell formation in the human U937 promonocytic cell line in a dose- and time-dependent manner. → Ox-LDL induced expression of P-selectin through degradation of IkBa and augment of NF-kB activity and protein level during macrophage-derived foam cell formation. → P-selectin and NF-kB may be identified as pivotal regulators of ox-LDL-induced foam cell formation. → Therapy based on the inhibition of P-selectin and NF-kB may complement conventional treatments to prevent atherosclerosis. -- Abstract: Oxidized low-density lipoprotein (ox-LDL) plays a critical role in regulation of atherosclerosis. However, little is known about the role of Nuclear factor kB (NF-kB) activity-dependent P-selectin in ox-LDL-induced foam cell formation during atherosclerosis. In this study, we first investigated ox-LDL induced foam cell formation in the human U937 promonocytic cell line in a dose- and time-dependent manner. Treatment of U937 cells with ox-LDL increased lipid accumulation as well as intracellular cholesterol content. Next, a comparative analysis of gene expression profiling using cDNA microarray and Real-time-PCR indicated that ox-LDL exposure induced, in three treated groups, an extremely marked increase in the mRNA level of P-selectin. Protein levels of P-selectin and its upstream regulators IkBa and NF-kB showed that NF-kB pathway is involved in the ox-LDL-induced foam cell formation. Finally, overexpression of NF-kB significantly accelerated, whereas, inhibition of NF-kB with siRNA remarkably attenuated ox-LDL-induced macrophage-derived foam cell formation. It was concluded that the activity of NF-kB is augmented during macrophage-derived foam cell formation. Activation of NF-kB increased, whereas, inhibition of NF-kB decreased ox-LDL-induced P-selectin expression and lipid accumulation in macrophages, suggesting ox-LDL induced expression of P-selectin through degradation of IkBa and activation of NF-kB in the regulation of foam

  6. NF-kB activity-dependent P-selectin involved in ox-LDL-induced foam cell formation in U937 cell

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yi, E-mail: wangyi2004a@126.com [Department of Cardiology, Shanghai First People' s Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200080 (China); Wang, Xiang; Sun, Minghui; Zhang, Zhenyu; Cao, Heng; Chen, Xiaoqing [Department of Cardiology, Shanghai First People' s Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200080 (China)

    2011-08-05

    Highlights: {yields} Ox-LDL induced foam cell formation in the human U937 promonocytic cell line in a dose- and time-dependent manner. {yields} Ox-LDL induced expression of P-selectin through degradation of IkBa and augment of NF-kB activity and protein level during macrophage-derived foam cell formation. {yields} P-selectin and NF-kB may be identified as pivotal regulators of ox-LDL-induced foam cell formation. {yields} Therapy based on the inhibition of P-selectin and NF-kB may complement conventional treatments to prevent atherosclerosis. -- Abstract: Oxidized low-density lipoprotein (ox-LDL) plays a critical role in regulation of atherosclerosis. However, little is known about the role of Nuclear factor kB (NF-kB) activity-dependent P-selectin in ox-LDL-induced foam cell formation during atherosclerosis. In this study, we first investigated ox-LDL induced foam cell formation in the human U937 promonocytic cell line in a dose- and time-dependent manner. Treatment of U937 cells with ox-LDL increased lipid accumulation as well as intracellular cholesterol content. Next, a comparative analysis of gene expression profiling using cDNA microarray and Real-time-PCR indicated that ox-LDL exposure induced, in three treated groups, an extremely marked increase in the mRNA level of P-selectin. Protein levels of P-selectin and its upstream regulators IkBa and NF-kB showed that NF-kB pathway is involved in the ox-LDL-induced foam cell formation. Finally, overexpression of NF-kB significantly accelerated, whereas, inhibition of NF-kB with siRNA remarkably attenuated ox-LDL-induced macrophage-derived foam cell formation. It was concluded that the activity of NF-kB is augmented during macrophage-derived foam cell formation. Activation of NF-kB increased, whereas, inhibition of NF-kB decreased ox-LDL-induced P-selectin expression and lipid accumulation in macrophages, suggesting ox-LDL induced expression of P-selectin through degradation of IkBa and activation of NF-kB in the

  7. Sympathetic Neurotransmitters Modulate Osteoclastogenesis and Osteoclast Activity in the Context of Collagen-Induced Arthritis

    Science.gov (United States)

    Muschter, Dominique; Schäfer, Nicole; Stangl, Hubert; Straub, Rainer H.; Grässel, Susanne

    2015-01-01

    Excessive synovial osteoclastogenesis is a hallmark of rheumatoid arthritis (RA). Concomitantly, local synovial changes comprise neuronal components of the peripheral sympathetic nervous system. Here, we wanted to analyze if collagen-induced arthritis (CIA) alters bone marrow-derived macrophage (BMM) osteoclastogenesis and osteoclast activity, and how sympathetic neurotransmitters participate in this process. Therefore, BMMs from Dark Agouti rats at different CIA stages were differentiated into osteoclasts in vitro and osteoclast number, cathepsin K activity, matrix resorption and apoptosis were analyzed in the presence of acetylcholine (ACh), noradrenaline (NA) vasoactive intestinal peptide (VIP) and assay-dependent, adenylyl cyclase activator NKH477. We observed modulation of neurotransmitter receptor mRNA expression in CIA osteoclasts without affecting protein level. CIA stage-dependently altered marker gene expression associated with osteoclast differentiation and activity without affecting osteoclast number or activity. Neurotransmitter stimulation modulated osteoclast differentiation, apoptosis and activity. VIP, NA and adenylyl cyclase activator NKH477 inhibited cathepsin K activity and osteoclastogenesis (NKH477, 10-6M NA) whereas ACh mostly acted pro-osteoclastogenic. We conclude that CIA alone does not affect metabolism of in vitro generated osteoclasts whereas stimulation with NA, VIP plus specific activation of adenylyl cyclase induced anti-resorptive effects probably mediated via cAMP signaling. Contrary, we suggest pro-osteoclastogenic and pro-resorptive properties of ACh mediated via muscarinic receptors. PMID:26431344

  8. Estimation of induced activity in super conducting cyclotron at VECC: Monte Carlo calculations

    International Nuclear Information System (INIS)

    Chatterjee, S.; Bandyopadhyay, T.

    2011-01-01

    Super Conducting Cyclotron (K500) at Variable Energy Cyclotron Centre, Kolkata (VECC) is at an advanced stage of commissioning and has successfully delivered many internal beams (light to heavy particles) up to the extraction radius. One of the external beam lines has already been completed and commissioned. The SCC along with the other subsystems is getting ready to deliver beam for experiments. Beam loss of during beam tuning and also during a steady beam delivery to the different experimental facilities due to many operational factors and requirements. Extraction of beam from the machine to the beam line is also a major player for the loss of beam. The interaction of the lost beam of accelerated charge particles with the machine parts will undergo different nuclear reaction and induced activity will be produced at the different parts of the machine. Moreover secondary neutrons produced having energy maximum limiting to the beam energy will also produce radioactivity in the different parts of the machine as well it will also induce radioactivity on the radiation shield constructed around the accelerator. Radio-activation of different parts of an accelerator, radiation shield walls around the machine and materials available in the room poses a radiation hazard inside the machine vault and experimental caves especially during maintenance of the machine. During the shutdown and maintenance period of the machine occupational workers will be exposed to these induced activity produced during operation of the machine. An effort was made to estimate these residual activity and dose for 80 MeV proton bombarded on Stainless Steel thereon activity produced on different materials like Cu, Al, Concrete and SS of different thickness. Cu, Al, SS are among many other materials which are widely used for fabrication of any accelerator. A simulation of the scenario was created using a Monte Carlo approach using FLUKA 2006.3b-general purpose multi particle transport code. Estimation

  9. Memantine Can Reduce Ethanol-Induced Caspase-3 Activity and Apoptosis in H4 Cells by Decreasing Intracellular Calcium.

    Science.gov (United States)

    Wang, Xiaolong; Chen, Jiajun; Wang, Hongbo; Yu, Hao; Wang, Changliang; You, Jiabin; Wang, Pengfei; Feng, Chunmei; Xu, Guohui; Wu, Xu; Zhao, Rui; Zhang, Guohua

    2017-08-01

    Caspase-3 activation and apoptosis are associated with various neurodegenerative disorders. Calcium activation is an important factor in promoting apoptosis. We, therefore, assessed the role of intracellular calcium in ethanol-induced activation of caspase-3 in H4 human neuroglioma cells and the protective effect of the NMDA receptor antagonist, memantine, on ethanol-induced apoptosis in H4 cells. H4 cells were treated with 100 mM EtOH (in culture medium) for 2 days. For interaction studies, cells were treated with memantine (4 μM), EDTA (1 mM), or BAPTA-AM (10 μM) before treatment with EtOH. Knockdown of the gene encoding the NR1 subunit of the NMDA receptor was performed using RNAi. Apoptosis was detected by Annexin V-FITC/PI staining and flow cytometry. Cell viability was detected using an MTS cell proliferation kit. Fluorescence dual wavelength spectrophotometry was used to determine the intracellular calcium concentration. The levels of NR1, caspase-3, IP3R1, and SERCA1 proteins were detected by western blotting. NR1, IP3R1, and SERCA1 mRNA levels were detected by qPCR. We observed increased expression of NR1, IP3R1, SERCA1, and increased intracellular levels of calcium ions in H4 cells exposed to ethanol. In addition, the calcium chelators, EDTA and BAPTA, and RNAi disruption of the NMDA receptor reduced ethanol-induced caspase-3 activation in H4 cells. Memantine treatment reduced the ethanol-induced increase of intracellular calcium, caspase-3 activation, apoptosis, and the ethanol-induced decrease in cell viability. Our results indicate that ethanol-induced caspase-3 activation and apoptosis are likely to be dependent on cytosolic calcium levels and that they can be reduced by memantine treatment.

  10. Preparation and characterization of activated carbon from pistachio nut shells via microwave-induced chemical activation

    Energy Technology Data Exchange (ETDEWEB)

    Foo, K. Y. [School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia); Hameed, B.H., E-mail: chbassim@eng.usm.my [School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia)

    2011-07-15

    In this work, pistachio nut shell, a biomass residue abundantly available from the pistachio nut processing industries, was utilized as a feedstock for the preparation of activated carbon (PSAC) via microwave assisted KOH activation. The activation step was performed at the microwave input power of 600 W and irradiation time of 7 min. The porosity, functional and surface chemistry were featured by means of low temperature nitrogen adsorption, scanning electron microscopy and Fourier transform infrared spectroscopy. Result showed that the BET surface area, Langmuir surface area, and total pore volume of PSAC were 700.53 m{sup 2} g{sup -1}, 1038.78 m{sup 2} g{sup -1} and 0.375 m{sup 3} g{sup -1}, respectively. The adsorptive property of PSAC was tested using methylene blue dye as the targeted adsorbate. Equilibrium data was best fitted by the Langmuir isotherm model, showing a monolayer adsorption capacity of 296.57 mg g{sup -1}. The study revealed the potentiality of microwave-induced activation as a viable activation method. -- Highlights: {yields} Pistachio nut shell activated carbon (PSAC) was prepared via microwave assisted KOH activation. {yields} The activation step was performed at the microwave input power of 600 W and irradiation time of 7 min. {yields} BET surface area of PSAC was 700.53 m{sup 2}/g. {yields} Monolayer adsorption capacity of PSAC for MB was 296.57 mg/g.

  11. Preparation and characterization of activated carbon from pistachio nut shells via microwave-induced chemical activation

    International Nuclear Information System (INIS)

    Foo, K.Y.; Hameed, B.H.

    2011-01-01

    In this work, pistachio nut shell, a biomass residue abundantly available from the pistachio nut processing industries, was utilized as a feedstock for the preparation of activated carbon (PSAC) via microwave assisted KOH activation. The activation step was performed at the microwave input power of 600 W and irradiation time of 7 min. The porosity, functional and surface chemistry were featured by means of low temperature nitrogen adsorption, scanning electron microscopy and Fourier transform infrared spectroscopy. Result showed that the BET surface area, Langmuir surface area, and total pore volume of PSAC were 700.53 m 2 g -1 , 1038.78 m 2 g -1 and 0.375 m 3 g -1 , respectively. The adsorptive property of PSAC was tested using methylene blue dye as the targeted adsorbate. Equilibrium data was best fitted by the Langmuir isotherm model, showing a monolayer adsorption capacity of 296.57 mg g -1 . The study revealed the potentiality of microwave-induced activation as a viable activation method. -- Highlights: → Pistachio nut shell activated carbon (PSAC) was prepared via microwave assisted KOH activation. → The activation step was performed at the microwave input power of 600 W and irradiation time of 7 min. → BET surface area of PSAC was 700.53 m 2 /g. → Monolayer adsorption capacity of PSAC for MB was 296.57 mg/g.

  12. Rac1 activation in podocytes induces the spectrum of nephrotic syndrome.

    Science.gov (United States)

    Robins, Richard; Baldwin, Cindy; Aoudjit, Lamine; Côté, Jean-François; Gupta, Indra R; Takano, Tomoko

    2017-08-01

    Hyper-activation of Rac1, a small GTPase, in glomerular podocytes has been implicated in the pathogenesis of familial proteinuric kidney diseases. However, the role of Rac1 in acquired nephrotic syndrome is unknown. To gain direct insights into this, we generated a transgenic mouse model expressing a doxycycline-inducible constitutively active form of Rac1 (CA-Rac1) in podocytes. Regardless of the copy number, proteinuria occurred rapidly within five days, and the histology resembled minimal change disease. The degree and severity of proteinuria were dependent on the transgene copy number. Upon doxycycline withdrawal, proteinuria resolved completely (one copy) or nearly completely (two copy). After one month of doxycycline treatment, two-copy mice developed glomerulosclerosis that resembled focal segmental glomerulosclerosis (FSGS) with urinary shedding of transgene-expressing podocytes. p38 MAPK was activated in podocytes upon CA-Rac1 induction while a p38 inhibitor attenuated proteinuria, podocyte loss, and glomerulosclerosis. Mechanistically, activation of Rac1 in cultured mouse podocytes reduced adhesiveness to laminin and induced redistribution of β1 integrin, and both were partially reversed by the p38 inhibitor. Activation of Rac1 in podocytes was also seen in kidney biopsies from patients with minimal change disease and idiopathic FSGS by immunofluorescence while sera from the same patients activated Rac1 in cultured human podocytes. Thus, activation of Rac1 in podocytes causes a spectrum of disease ranging from minimal change disease to FSGS, due to podocyte detachment from the glomerular basement membrane that is partially dependent on p38 MAPK. Copyright © 2017 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

  13. Copper-induced activation of TRP channels promotes extracellular calcium entry and activation of CaMs and CDPKs leading to copper entry and membrane depolarization in Ulva compressa

    Directory of Open Access Journals (Sweden)

    Melissa eGómez

    2015-03-01

    Full Text Available In order to identify channels involved in membrane depolarization, Ulva compressa was incubated with agonists of TRP channels C5, A1 and V1 and the level of intracellular calcium was detected. Agonists of TRPC5, A1 and V1 induced increases in intracellular calcium at 4, 9 and 12 min of exposure, respectively, and antagonists of TRPC5, A1 and V1 corresponding to SKF-96365 (SKF, HC-030031 (HC and capsazepin (CPZ, respectively, inhibited calcium increases indicating that functional TRPs exist in U. compressa. In addition, copper excess induced increases in intracellular calcium at 4, 9 and 12 min which were inhibited by SKF, HC and CPZ, respectively, indicating that copper activate TRPC5, A1 and V1 channels. Moreover, copper-induced calcium increases were inhibited by EGTA, a non-permeable calcium chelating agent, but not by thapsigargin, an inhibitor of endoplasmic reticulum (ER calcium ATPase, indicating that activation of TRPs leads to extracellular calcium entry. Furthermore, copper-induced calcium increases were not inhibited by W-7, an inhibitor of CaMs, and staurosporine, an inhibitor of CDPKs, indicating that extracellular calcium entry did not require CaMs and CDPKs activation. In addition, copper induced membrane depolarization events at 4, 8 and 11 min and these events were inhibited by SKF, HC, CPZ and bathocuproine, a specific copper chelating agent, indicating copper entry through TRP channels leading to membrane depolarization. Moreover, membrane depolarization events were inhibited by W-7 and staurosporine, indicating that CaMs and CDPKs are required in order to activate TRPs to allow copper entry. Thus, light-dependent copper-induced activation TRPC5, A1 and V1 promotes extracellular calcium entry leading to activation of CaMs and CDPKs which, in turn, promotes copper entry through these TRP channels leading to membrane depolarization.

  14. Dasatinib inhibits both osteoclast activation and prostate cancer PC-3 cell-induced osteoclast formation

    Science.gov (United States)

    Araujo, John C.; Poblenz, Ann; Corn, Paul G.; Parikh, Nila U.; Starbuck, Michael W.; Thompson, Jerry T.; Lee, Francis; Logothetis, Christopher J.; Darnay, Bryant G.

    2013-01-01

    Purpose Therapies to target prostate cancer bone metastases have only limited effects. New treatments are focused on the interaction between cancer cells, bone marrow cells and the bone matrix. Osteoclasts play an important role in the development of bone tumors caused by prostate cancer. Since Src kinase has been shown to be necessary for osteoclast function, we hypothesized that dasatinib, a Src family kinase inhibitor, would reduce osteoclast activity and prostate cancer (PC-3) cell-induced osteoclast formation. Results Dasatinib inhibited RANKL-induced osteoclast differentiation of bone marrow-derived monocytes with an EC50 of 7.5 nM. PC-3 cells, a human prostate cancer cell line, were able to differentiate RAW 264.7 cells, a murine monocytic cell line, into osteoclasts and dasatinib inhibited this differentiation. In addition, conditioned medium from PC-3 cell cultures was able to differentiate RAW 264.7 cells into osteoclasts and this too, was inhibited by dasatinib. Even the lowest concentration of dasatinib, 1.25 nmol, inhibited osteoclast differentiation by 29%. Moreover, dasatinib inhibited osteoclast activity by 58% as measured by collagen 1 release. Experimental design We performed in vitro experiments utilizing the Src family kinase inhibitor dasatinib to target osteoclast activation as a means of inhibiting prostate cancer bone metastases. Conclusion Dasatinib inhibits osteoclast differentiation of mouse primary bone marrow-derived monocytes and PC-3 cell-induced osteoclast differentiation. Dasatinib also inhibits osteoclast degradation activity. Inhibiting osteoclast differentiation and activity may be an effective targeted therapy in patients with prostate cancer bone metastases. PMID:19855158

  15. Phosphoinositide 3–kinase γ participates in T cell receptor–induced T cell activation

    Science.gov (United States)

    Alcázar, Isabela; Marqués, Miriam; Kumar, Amit; Hirsch, Emilio; Wymann, Matthias; Carrera, Ana C.; Barber, Domingo F.

    2007-01-01

    Class I phosphoinositide 3–kinases (PI3Ks) constitute a family of enzymes that generates 3-phosphorylated polyphosphoinositides at the cell membrane after stimulation of protein tyrosine (Tyr) kinase–associated receptors or G protein–coupled receptors (GPCRs). The class I PI3Ks are divided into two types: class IA p85/p110 heterodimers, which are activated by Tyr kinases, and the class IB p110γ isoform, which is activated by GPCR. Although the T cell receptor (TCR) is a protein Tyr kinase–associated receptor, p110γ deletion affects TCR-induced T cell stimulation. We examined whether the TCR activates p110γ, as well as the consequences of interfering with p110γ expression or function for T cell activation. We found that after TCR ligation, p110γ interacts with Gαq/11, lymphocyte-specific Tyr kinase, and ζ-associated protein. TCR stimulation activates p110γ, which affects 3-phosphorylated polyphosphoinositide levels at the immunological synapse. We show that TCR-stimulated p110γ controls RAS-related C3 botulinum substrate 1 activity, F-actin polarization, and the interaction between T cells and antigen-presenting cells, illustrating a crucial role for p110γ in TCR-induced T cell activation. PMID:17998387

  16. Effects of alpha-AMPK knockout on exercise-induced gene activation in mouse skeletal muscle

    DEFF Research Database (Denmark)

    Jørgensen, Sebastian Beck; Wojtaszewski, Jørgen; Viollet, Benoit

    2005-01-01

    We tested the hypothesis that 5'AMP-activated protein kinase (AMPK) plays an important role in regulating the acute, exercise-induced activation of metabolic genes in skeletal muscle, which were dissected from whole-body a2- and a1-AMPK knockout (KO) and wild-type (WT) mice at rest, after treadmi...

  17. Uric acid ameliorates indomethacin-induced enteropathy in mice through its antioxidant activity.

    Science.gov (United States)

    Yasutake, Yuichi; Tomita, Kengo; Higashiyama, Masaaki; Furuhashi, Hirotaka; Shirakabe, Kazuhiko; Takajo, Takeshi; Maruta, Koji; Sato, Hirokazu; Narimatsu, Kazuyuki; Yoshikawa, Kenichi; Okada, Yoshikiyo; Kurihara, Chie; Watanabe, Chikako; Komoto, Shunsuke; Nagao, Shigeaki; Matsuo, Hirotaka; Miura, Soichiro; Hokari, Ryota

    2017-11-01

    Uric acid is excreted from blood into the intestinal lumen, yet the roles of uric acid in intestinal diseases remain to be elucidated. The study aimed to determine whether uric acid could reduce end points associated with nonsteroidal anti-inflammatory drug (NSAID)-induced enteropathy. A mouse model of NSAID-induced enteropathy was generated by administering indomethacin intraperitoneally to 8-week-old male C57BL/6 mice, and then vehicle or uric acid was administered orally. A group of mice treated with indomethacin was also concurrently administered inosinic acid, a uric acid precursor, and potassium oxonate, an inhibitor of uric acid metabolism, intraperitoneally. For in vitro analysis, Caco-2 cells treated with indomethacin were incubated in the presence or absence of uric acid. Oral administration of uric acid ameliorated NSAID-induced enteropathy in mice even though serum uric acid levels did not increase. Intraperitoneal administration of inosinic acid and potassium oxonate significantly elevated serum uric acid levels and ameliorated NSAID-induced enteropathy in mice. Both oral uric acid treatment and intraperitoneal treatment with inosinic acid and potassium oxonate significantly decreased lipid peroxidation in the ileum of mice with NSAID-induced enteropathy. Treatment with uric acid protected Caco-2 cells from indomethacin-induced oxidative stress, lipid peroxidation, and cytotoxicity. Uric acid within the intestinal lumen and in serum had a protective effect against NSAID-induced enteropathy in mice, through its antioxidant activity. Uric acid could be a promising therapeutic target for NSAID-induced enteropathy. © 2017 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

  18. PPARα deficiency augments a ketogenic diet-induced circadian PAI-1 expression possibly through PPARγ activation in the liver

    International Nuclear Information System (INIS)

    Oishi, Katsutaka; Uchida, Daisuke; Ohkura, Naoki; Horie, Shuichi

    2010-01-01

    Research highlights: → PPARα deficiency augments a ketogenic diet-induced circadian PAI-1 expression. → Hepatic expressions of PPARγ and PCG-1α are induced by a ketogenic diet. → PPARγ antagonist attenuates a ketogenic diet-induced PAI-1 expression. → Ketogenic diet advances the phase of circadian clock in a PPARα-independent manner. -- Abstract: An increased level of plasminogen activator inhibitor-1 (PAI-1) is considered a risk factor for cardiovascular diseases, and PAI-1 gene expression is under the control of molecular circadian clocks in mammals. We recently showed that PAI-1 expression is augmented in a phase-advanced circadian manner in mice fed with a ketogenic diet (KD). To determine whether peroxisome proliferator-activated receptor α (PPARα) is involved in hypofibrinolytic status induced by a KD, we examined the expression profiles of PAI-1 and circadian clock genes in PPARα-null KD mice. Chronic administration of bezafibrate induced the PAI-1 gene expression in a PPARα-dependent manner. Feeding with a KD augmented the circadian expression of PAI-1 mRNA in the hearts and livers of wild-type (WT) mice as previously described. The KD-induced mRNA expression of typical PPARα target genes such as Cyp4A10 and FGF21 was damped in PPARα-null mice. However, plasma PAI-1 concentrations were significantly more elevated in PPARα-null KD mice in accordance with hepatic mRNA levels. These observations suggest that PPARα activation is dispensable for KD-induced PAI-1 expression. We also found that hyperlipidemia, fatty liver, and the hepatic expressions of PPARγ and its coactivator PCG-1α were more effectively induced in PPARα-null, than in WT mice on a KD. Furthermore, KD-induced hepatic PAI-1 expression was significantly suppressed by supplementation with bisphenol A diglycidyl ether, a PPARγ antagonist, in both WT and PPARα-null mice. PPARγ activation seems to be involved in KD-induced hypofibrinolysis by augmenting PAI-1 gene expression

  19. Targeted activation of endothelin-1 exacerbates hypoxia-induced pulmonary hypertension

    International Nuclear Information System (INIS)

    Satwiko, Muhammad Gahan; Ikeda, Koji; Nakayama, Kazuhiko; Yagi, Keiko; Hocher, Berthold; Hirata, Ken-ichi; Emoto, Noriaki

    2015-01-01

    Pulmonary arterial hypertension (PAH) is a fatal disease that eventually results in right heart failure and death. Current pharmacologic therapies for PAH are limited, and there are no drugs that could completely cure PAH. Enhanced activity of endothelin system has been implicated in PAH severity and endothelin receptor antagonists have been used clinically to treat PAH. However, there is limited experimental evidence on the direct role of enhanced endothelin system activity in PAH. Here, we investigated the correlation between endothelin-1 (ET-1) and PAH using ET-1 transgenic (ETTG) mice. Exposure to chronic hypoxia increased right ventricular pressure and pulmonary arterial wall thickness in ETTG mice compared to those in wild type mice. Of note, ETTG mice exhibited modest but significant increase in right ventricular pressure and vessel wall thickness relative to wild type mice even under normoxic conditions. To induce severe PAH, we administered SU5416, a vascular endothelial growth factor receptor inhibitor, combined with exposure to chronic hypoxia. Treatment with SU5416 modestly aggravated hypoxia-induced pulmonary hypertension, right ventricular hypertrophy, and pulmonary arterial vessel wall thickening in ETTG mice in association with increased interleukin-6 expression in blood vessels. However, there was no sign of obliterative endothelial cell proliferation and plexiform lesion formation in the lungs. These results demonstrated that enhanced endothelin system activity could be a causative factor in the development of PAH and provided rationale for the inhibition of endothelin system to treat PAH. - Highlights: • Role of endothelin-1 in pulmonary arterial hypertension (PAH) was investigated. • The endothelin-1 transgenic (ETTG) and wild type (WT) mice were analyzed. • ETTG mice spontaneously developed PAH under normoxia conditions. • SU5416 further aggravated PAH in ETTG mice. • Enhanced endothelin system activity could be a causative factor in

  20. Targeted activation of endothelin-1 exacerbates hypoxia-induced pulmonary hypertension

    Energy Technology Data Exchange (ETDEWEB)

    Satwiko, Muhammad Gahan [Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe (Japan); Ikeda, Koji [Department of Clinical Pharmacy, Kobe Pharmaceutical University, Kobe (Japan); Nakayama, Kazuhiko [Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe (Japan); Yagi, Keiko [Department of Clinical Pharmacy, Kobe Pharmaceutical University, Kobe (Japan); Hocher, Berthold [Institute for Nutritional Science, University of Potsdam, Potsdam (Germany); Hirata, Ken-ichi [Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe (Japan); Emoto, Noriaki, E-mail: emoto@med.kobe-u.ac.jp [Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe (Japan); Department of Clinical Pharmacy, Kobe Pharmaceutical University, Kobe (Japan)

    2015-09-25

    Pulmonary arterial hypertension (PAH) is a fatal disease that eventually results in right heart failure and death. Current pharmacologic therapies for PAH are limited, and there are no drugs that could completely cure PAH. Enhanced activity of endothelin system has been implicated in PAH severity and endothelin receptor antagonists have been used clinically to treat PAH. However, there is limited experimental evidence on the direct role of enhanced endothelin system activity in PAH. Here, we investigated the correlation between endothelin-1 (ET-1) and PAH using ET-1 transgenic (ETTG) mice. Exposure to chronic hypoxia increased right ventricular pressure and pulmonary arterial wall thickness in ETTG mice compared to those in wild type mice. Of note, ETTG mice exhibited modest but significant increase in right ventricular pressure and vessel wall thickness relative to wild type mice even under normoxic conditions. To induce severe PAH, we administered SU5416, a vascular endothelial growth factor receptor inhibitor, combined with exposure to chronic hypoxia. Treatment with SU5416 modestly aggravated hypoxia-induced pulmonary hypertension, right ventricular hypertrophy, and pulmonary arterial vessel wall thickening in ETTG mice in association with increased interleukin-6 expression in blood vessels. However, there was no sign of obliterative endothelial cell proliferation and plexiform lesion formation in the lungs. These results demonstrated that enhanced endothelin system activity could be a causative factor in the development of PAH and provided rationale for the inhibition of endothelin system to treat PAH. - Highlights: • Role of endothelin-1 in pulmonary arterial hypertension (PAH) was investigated. • The endothelin-1 transgenic (ETTG) and wild type (WT) mice were analyzed. • ETTG mice spontaneously developed PAH under normoxia conditions. • SU5416 further aggravated PAH in ETTG mice. • Enhanced endothelin system activity could be a causative factor in