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  1. Centrosomal protein 55 activates NF-?B signalling and promotes pancreatic cancer cells aggressiveness

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    Peng, Tao; Zhou, Wei; Guo, Feng; Wu, He-shui; Wang, Chun-you; Wang, Li; Yang, Zhi-yong

    2017-01-01

    Centrosomal protein 55 (CEP55) is a microtubule-bundling protein that participants in cell mitosis. It is overexpressed in several solid tumours and promotes the growth and invasion of cancer cells. However, the role of CEP55 in pancreatic cancer (PANC) remains unclear. Herein, upregulated expression of CEP55 (associated with poor prognosis) was detected in PANC using quantitative real-time reverse transcription PCR, western blotting, and immunohistochemistry. Cell migration, colony formation...

  2. G Protein-Coupled Receptor 87 (GPR87 Promotes Cell Proliferation in Human Bladder Cancer Cells

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    Xia Zhang

    2015-10-01

    Full Text Available G protein-coupled receptor 87 (GPR87 is a newly deorphanized member of the cell surface molecule G protein-coupled receptor family. GPR signaling was shown to play a role in promotion of cell growth and survival, metastasis, and drug resistance. The overexpression of GPR87 has also been reported in many malignant tumors including bladder cancer. The aim of the present study is to examine the effect of silencing GPR87 expression with a replication-deficient recombinant adenoviral vector expressing short hairpin RNA targeting GPR87 (Ad-shGPR87 and to explore the underlying molecular mechanisms in bladder cancer cells. Six GPR87-expressing human bladder cancer cells, HT1197, HT1376, J82, RT112, TCCSUP and UMUC3, were used. Infection with Ad-shGPR87 effectively downregulated the GPR87 expression, and significantly reduced the percentage of viable cells in 4 of 6 cell lines as detected by an MTT assay. Significant inhibition on cell proliferation with Ad-shGPR87 was observed in the wild-type p53 bladder cancer cell lines (HT1197, RT112, TCCSUP and UMUC3, but not in the mutant p53 cells (HT1376 and J82. As represented by a wild-type p53 RT112 cell, Ad-shGPR87 infection significantly enhanced p53 and p21 expression and caused caspase-dependent apoptosis. Furthermore, the treatment with Ad-shGPR87 exerted a significant antitumor effect against the GPR87-expressing RT112 xenografts. GPR87 appeared to be a promising target for gene therapy, and Ad-shGPR87 had strong antitumor effects, specifically anti-proliferative and pro-apoptotic effects, against GPR87-expressing human bladder cancer cells.

  3. RNA-binding proteins ZFP36L1 and ZFP36L2 promote cell quiescence.

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    Galloway, Alison; Saveliev, Alexander; Łukasiak, Sebastian; Hodson, Daniel J; Bolland, Daniel; Balmanno, Kathryn; Ahlfors, Helena; Monzón-Casanova, Elisa; Mannurita, Sara Ciullini; Bell, Lewis S; Andrews, Simon; Díaz-Muñoz, Manuel D; Cook, Simon J; Corcoran, Anne; Turner, Martin

    2016-04-22

    Progression through the stages of lymphocyte development requires coordination of the cell cycle. Such coordination ensures genomic integrity while cells somatically rearrange their antigen receptor genes [in a process called variable-diversity-joining (VDJ) recombination] and, upon successful rearrangement, expands the pools of progenitor lymphocytes. Here we show that in developing B lymphocytes, the RNA-binding proteins (RBPs) ZFP36L1 and ZFP36L2 are critical for maintaining quiescence before precursor B cell receptor (pre-BCR) expression and for reestablishing quiescence after pre-BCR-induced expansion. These RBPs suppress an evolutionarily conserved posttranscriptional regulon consisting of messenger RNAs whose protein products cooperatively promote transition into the S phase of the cell cycle. This mechanism promotes VDJ recombination and effective selection of cells expressing immunoglobulin-μ at the pre-BCR checkpoint. Copyright © 2016, American Association for the Advancement of Science.

  4. Staphylococcus aureus extracellular adherence protein triggers TNFα release, promoting attachment to endothelial cells via protein A.

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    Andrew M Edwards

    Full Text Available Staphylococcus aureus is a leading cause of bacteraemia, which frequently results in complications such as infective endocarditis, osteomyelitis and exit from the bloodstream to cause metastatic abscesses. Interaction with endothelial cells is critical to these complications and several bacterial proteins have been shown to be involved. The S. aureus extracellular adhesion protein (Eap has many functions, it binds several host glyco-proteins and has both pro- and anti-inflammatory activity. Unfortunately its role in vivo has not been robustly tested to date, due to difficulties in complementing its activity in mutant strains. We previously found Eap to have pro-inflammatory activity, and here show that purified native Eap triggered TNFα release in whole human blood in a dose-dependent manner. This level of TNFα increased adhesion of S. aureus to endothelial cells 4-fold via a mechanism involving protein A on the bacterial surface and gC1qR/p33 on the endothelial cell surface. The contribution this and other Eap activities play in disease severity during bacteraemia was tested by constructing an isogenic set of strains in which the eap gene was inactivated and complemented by inserting an intact copy elsewhere on the bacterial chromosome. Using a murine bacteraemia model we found that Eap expressing strains cause a more severe infection, demonstrating its role in invasive disease.

  5. Exogenous fatty acid binding protein 4 promotes human prostate cancer cell progression.

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    Uehara, Hisanori; Takahashi, Tetsuyuki; Oha, Mina; Ogawa, Hirohisa; Izumi, Keisuke

    2014-12-01

    Epidemiologic studies have found that obesity is associated with malignant grade and mortality in prostate cancer. Several adipokines have been implicated as putative mediating factors between obesity and prostate cancer. Fatty acid binding protein 4 (FABP4), a member of the cytoplasmic fatty acid binding protein multigene family, was recently identified as a novel adipokine. Although FABP4 is released from adipocytes and mean circulating concentrations of FABP4 are linked with obesity, effects of exogenous FABP4 on prostate cancer progression are unclear. In this study, we examined the effects of exogenous FABP4 on human prostate cancer cell progression. FABP4 treatment promoted serum-induced prostate cancer cell invasion in vitro. Furthermore, oleic acid promoted prostate cancer cell invasion only if FABP4 was present in the medium. These promoting effects were reduced by FABP4 inhibitor, which inhibits FABP4 binding to fatty acids. Immunostaining for FABP4 showed that exogenous FABP4 was taken up into DU145 cells in three-dimensional culture. In mice, treatment with FABP4 inhibitor reduced the subcutaneous growth and lung metastasis of prostate cancer cells. Immunohistochemical analysis showed that the number of apoptotic cells, positive for cleaved caspase-3 and cleaved PARP, was increased in subcutaneous tumors of FABP4 inhibitor-treated mice, as compared with control mice. These results suggest that exogenous FABP4 might promote human prostate cancer cell progression by binding with fatty acids. Additionally, exogenous FABP4 activated the PI3K/Akt pathway, independently of binding to fatty acids. Thus, FABP4 might be a key molecule to understand the mechanisms underlying the obesity-prostate cancer progression link. © 2014 UICC.

  6. Identifying and engineering promoters for high level and sustainable therapeutic recombinant protein production in cultured mammalian cells.

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    Ho, Steven C L; Yang, Yuansheng

    2014-08-01

    Promoters are essential on plasmid vectors to initiate transcription of the transgenes when generating therapeutic recombinant proteins expressing mammalian cell lines. High and sustained levels of gene expression are desired during therapeutic protein production while gene expression is useful for cell engineering. As many finely controlled promoters exhibit cell and product specificity, new promoters need to be identified, optimized and carefully evaluated before use. Suitable promoters can be identified using techniques ranging from simple molecular biology methods to modern high-throughput omics screenings. Promoter engineering is often required after identification to either obtain high and sustained expression or to provide a wider range of gene expression. This review discusses some of the available methods to identify and engineer promoters for therapeutic recombinant protein expression in mammalian cells.

  7. The double bromodomain protein Brd2 promotes B cell expansion and mitogenesis.

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    Belkina, Anna C; Blanton, Wanda P; Nikolajczyk, Barbara S; Denis, Gerald V

    2014-03-01

    Bromodomain-containing transcriptional regulators represent new epigenetic targets in different hematologic malignancies. However, bromodomain-mediated mechanisms that couple histone acetylation to transcription in lymphopoiesis and govern mature lymphocyte mitogenesis are poorly understood. Brd2, a transcriptional coregulator that contains dual bromodomains and an extraterminal domain (the BET family), couples chromatin to cell-cycle progression. We reported previously the first functional characterization of a BET protein as an effector of mammalian mitogenic signal transduction: Eμ-Brd2 Tg mice develop "activated B cell" diffuse large B cell lymphoma. No other animal models exist for genetic or lentiviral expression of BET proteins, hampering testing of novel anti-BET anticancer drugs, such as JQ1. We transduced HSCs with Brd2 lentivirus and reconstituted recipient mice to test the hypothesis that Brd2 regulates hematopoiesis in BM and mitogenesis in the periphery. Forced expression of Brd2 provides an expansion advantage to the donor-derived B cell compartment in BM and increases mature B cell mitogenic responsiveness in vitro. Brd2 binds the cyclin A promoter in B cells, shown by ChIP, and increases cyclin A mRNA and protein levels, and S-phase progression in vitro in mitogen-stimulated primary B cells, but not T cells, reinforcing results from Eμ-Brd2 mice. The small molecule BET inhibitor JQ1 reduces B cell mitogenesis, consistent with the interpretation that BET inhibitors are antiproliferative. Brd2-specific knockdown experiments show that Brd2 is also required for hematopoiesis. We conclude that Brd2 plays a critical, independent role in regulation of mitogenic response genes, particularly cyclin A, in B cells.

  8. A secreted Salmonella protein induces a proinflammatory response in epithelial cells, which promotes neutrophil migration.

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    Lee, C A; Silva, M; Siber, A M; Kelly, A J; Galyov, E; McCormick, B A

    2000-10-24

    In response to Salmonella typhimurium, the intestinal epithelium generates an intense inflammatory response consisting largely of polymorphonuclear leukocytes (neutrophils, PMN) migrating toward and ultimately across the epithelial monolayer into the intestinal lumen. It has been shown that bacterial-epithelial cell interactions elicit the production of inflammatory regulators that promote transepithelial PMN migration. Although S. typhimurium can enter intestinal epithelial cells, bacterial internalization is not required for the signaling mechanisms that induce PMN movement. Here, we sought to determine which S. typhimurium factors and intestinal epithelial signaling pathways elicit the production of PMN chemoattractants by enterocytes. Our results suggest that S. typhimurium activates a protein kinase C-dependent signal transduction pathway that orchestrates transepithelial PMN movement. We show that the type III effector protein, SipA, is not only necessary but is sufficient to induce this proinflammatory response in epithelial cells. Our results force us to reconsider the long-held view that Salmonella effector proteins must be directly delivered into host cells from bacterial cells.

  9. Free fatty acid palmitate activates unfolded protein response pathway and promotes apoptosis in meniscus cells.

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    Haywood, J; Yammani, R R

    2016-05-01

    Obesity is the major risk factor for the development of osteoarthritis (OA); however, the mechanisms involved are not clearly understood. Obesity is associated with increased production of adipokine and elevated levels of circulating free fatty acids (FFA). A recent study has shown that saturated fatty acid palmitate induced pro-inflammatory and pro-apoptotic pathways in chondrocytes. Meniscus has been shown to be more susceptible than articular cartilage to catabolic stimuli. Thus, the aim of this study was to determine the effect of FFA (specifically, palmitate) on meniscus cells. Cultured primary porcine meniscus cells were stimulated with 500 μM FFA (palmitate and oleate) for 24 h to induce endoplasmic reticulum (ER) stress. After treatment, cell lysates were prepared and immunoblotted for C/EBP homologous protein (CHOP). To determine the activation of unfolded protein response (UPR) signaling, cell lysates were probed for cJun n-terminal kinase (JNK), cleaved caspase -3 and Xbp-1s, an alternative mRNA splicing product generated due to Ire1α activation. Treatment of isolated primary meniscus cells with palmitate but not oleate induced expression of CHOP and Xbp-1s. Palmitate treatment of meniscus cells also activated JNK and increased expression of caspase-3, thus promoting apoptosis in meniscus cells. Palmitate induces ER stress and promotes apoptotic pathways in meniscus cells. This is the first study to establish ER stress as a key metabolic mechanistic link between obesity and OA, in addition to (or operating with) biomechanical factors. Copyright © 2015 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  10. The novel protein C9orf116 promotes rat liver cell line BRL-3A proliferation.

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    Chunyan Zhang

    Full Text Available Our previous study has proved that the chromosome 9 open reading frame 116 (C9orf116 (NM_001106564.1 was significantly up-regulated in the proliferation phase of liver regeneration. To study its possible physiological function, we analyzed the effect of C9orf116 on BRL-3A cells via over-expression and interference technique. MTT results showed that the cell viability of the interference group was significantly lower than the control group at 48h after transfection (P<0.05, whereas it was significantly higher in the over-expression group (P<0.05. The flow cytometry results showed that C9orf116 knockdown or over-expression had little effect on BRL-3A cell apoptosis. However, the number of cells in division phase (G2/M was significantly reduced in the interference group (P<0.05, but significantly increased in the over-expression group (P<0.01. Furthermore, the expressions of cell proliferation-related genes CCNA2, CCND1 and MYC both at mRNA and protein levels were down-regulated in the interference group and up-regulated in the over-expression group. Therefore, we concluded that C9orf116 may promote cell proliferation by modulating cell cycle transition and the expression of key genes CCNA2, CCND1 and MYC in BRL-3A cells.

  11. GADD34 Function in Protein Trafficking Promotes Adaptation to Hyperosmotic Stress in Human Corneal Cells

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    Dawid Krokowski

    2017-12-01

    Full Text Available Summary: GADD34, a stress-induced regulatory subunit of the phosphatase PP1, is known to function in hyperosmotic stress through its well-known role in the integrated stress response (ISR pathway. Adaptation to hyperosmotic stress is important for the health of corneal epithelial cells exposed to changes in extracellular osmolarity, with maladaptation leading to dry eye syndrome. This adaptation includes induction of SNAT2, an endoplasmic reticulum (ER-Golgi-processed protein, which helps to reverse the stress-induced loss of cell volume and promote homeostasis through amino acid uptake. Here, we show that GADD34 promotes the processing of proteins synthesized on the ER during hyperosmotic stress independent of its action in the ISR. We show that GADD34/PP1 phosphatase activity reverses hyperosmotic-stress-induced Golgi fragmentation and is important for cis- to trans-Golgi trafficking of SNAT2, thereby promoting SNAT2 plasma membrane localization and function. These results suggest that GADD34 is a protective molecule for ocular diseases such as dry eye syndrome. : Here, Krokowski et al. show that GADD34/PP1 protects the microtubule network, prevents Golgi fragmentation, and preserves protein trafficking independent of its action in the integrated stress response (ISR. In osmoadaptation, GADD34 facilitates trans-Golgi-mediated processing of the endoplasmic reticulum (ER-synthesized amino acid transporter SNAT2, which in turn increases amino acid uptake. Keywords: SNAT2, GADD34, hyperosmotic stress, amino acid transport, Golgi fragmentation, ISR

  12. Saturated fatty acid palmitate negatively regulates autophagy by promoting ATG5 protein degradation in meniscus cells.

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    Mallik, Aritra; Yammani, Raghunatha R

    2018-07-20

    Obesity and associated metabolic factors are major risk factors for the development of osteoarthritis. Previously, we have shown that the free fatty acid palmitate induces endoplasmic reticulum (ER) stress and induces apoptosis in meniscus cells. However, the molecular mechanisms involved in these effects are not clearly understood. In our current study, we found that palmitate inhibits autophagy by modulating the protein levels of autophagy-related genes-5 (ATG5) that is associated with decreased lipidation of LC3 and increased activation of cleaved caspase 3. Pretreatment of meniscus cells with 4-phenyl butyric acid, a small molecule chemical chaperone that alleviates ER stress, or with MG-132, a proteasome inhibitor, restored normal levels of ATG5 and autophagosome formation, and decreased expression of cleaved caspase 3. Thus, our data suggest that palmitate downregulates autophagy in meniscus cells by degrading ATG5 protein via ER-associated protein degradation, and thus promotes apoptosis. This is the first study to demonstrate that palmitate-induced endoplasmic reticulum stress negatively regulates autophagy. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

  13. The yeast cell fusion protein Prm1p requires covalent dimerization to promote membrane fusion.

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    Alex Engel

    2010-05-01

    Full Text Available Prm1p is a multipass membrane protein that promotes plasma membrane fusion during yeast mating. The mechanism by which Prm1p and other putative regulators of developmentally controlled cell-cell fusion events facilitate membrane fusion has remained largely elusive. Here, we report that Prm1p forms covalently linked homodimers. Covalent Prm1p dimer formation occurs via intermolecular disulfide bonds of two cysteines, Cys-120 and Cys-545. PRM1 mutants in which these cysteines have been substituted are fusion defective. These PRM1 mutants are normally expressed, retain homotypic interaction and can traffic to the fusion zone. Because prm1-C120S and prm1-C545S mutants can form covalent dimers when coexpressed with wild-type PRM1, an intermolecular C120-C545 disulfide linkage is inferred. Cys-120 is adjacent to a highly conserved hydrophobic domain. Mutation of a charged residue within this hydrophobic domain abrogates formation of covalent dimers, trafficking to the fusion zone, and fusion-promoting activity. The importance of intermolecular disulfide bonding informs models regarding the mechanism of Prm1-mediated cell-cell fusion.

  14. Protein arginine methyltransferase 5 regulates multiple signaling pathways to promote lung cancer cell proliferation

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    Sheng, Xiumei; Wang, Zhengxin

    2016-01-01

    Protein arginine methyltransferase 5 (PRMT5) catalyzes the formation of symmetrical dimethylation of arginine residues in proteins. WD repeat domain 77 (WDR77), also known as p44, MEP50, or WD45, forms a stoichiometric complex with PRMT5. The PRMT5/p44 complex is required for cellular proliferation of lung and prostate epithelial cells during earlier stages of development and is re-activated during prostate and lung tumorigenesis. The molecular mechanisms by which PRMT5 and p44 promote cellular proliferation are unknown. Expression of PRMT5 and p44 in lung and prostate cancer cells was silenced and their target genes were identified. The regulation of target genes was validated in various cancer cells during lung development and tumorigenesis. Altered expression of target genes was achieved by ectopic cDNA expression and shRNA-mediated silencing. PRMT5 and p44 regulate expression of a specific set of genes encoding growth and anti-growth factors, including receptor tyrosine kinases and antiproliferative proteins. Genes whose expression was suppressed by PRMT5 and p44 encoded anti-growth factors and inhibited cell growth when ectopically expressed. In contrast, genes whose expression was enhanced by PRMT5 and p44 encoded growth factors and increased cell growth when expressed. Altered expression of target genes is associated with re-activation of PRMT5 and p44 during lung tumorigenesis. Our data provide the molecular basis by which PRMT5 and p44 regulate cell growth and lay a foundation for further investigation of their role in lung tumor initiation. The online version of this article (doi:10.1186/s12885-016-2632-3) contains supplementary material, which is available to authorized users

  15. Zinc finger protein 598 inhibits cell survival by promoting UV-induced apoptosis.

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    Yang, Qiaohong; Gupta, Romi

    2018-01-19

    UV is one of the major causes of DNA damage induced apoptosis. However, cancer cells adopt alternative mechanisms to evade UV-induced apoptosis. To identify factors that protect cancer cells from UV-induced apoptosis, we performed a genome wide short-hairpin RNA (shRNA) screen, which identified Zinc finger protein 598 (ZNF598) as a key regulator of UV-induced apoptosis. Here, we show that UV irradiation transcriptionally upregulates ZNF598 expression. Additionally, ZNF598 knockdown in cancer cells inhibited UV-induced apoptosis. In our study, we observe that ELK1 mRNA level as well as phosphorylated ELK1 levels was up regulated upon UV irradiation, which was necessary for UV irradiation induced upregulation of ZNF598. Cells expressing ELK1 shRNA were also resistant to UV-induced apoptosis, and phenocopy ZNF598 knockdown. Upon further investigation, we found that ZNF598 knockdown inhibits UV-induced apoptotic gene expression, which matches with decrease in percentage of annexin V positive cell. Similarly, ectopic expression of ZNF598 promoted apoptotic gene expression and also increased annexin V positive cells. Collectively, these results demonstrate that ZNF598 is a UV irradiation regulated gene and its loss results in resistance to UV-induced apoptosis.

  16. Inhibition of SNW1 association with spliceosomal proteins promotes apoptosis in breast cancer cells

    International Nuclear Information System (INIS)

    Sato, Naoki; Maeda, Masao; Sugiyama, Mai; Ito, Satoko; Hyodo, Toshinori; Masuda, Akio; Tsunoda, Nobuyuki; Kokuryo, Toshio; Hamaguchi, Michinari; Nagino, Masato; Senga, Takeshi

    2015-01-01

    RNA splicing is a fundamental process for protein synthesis. Recent studies have reported that drugs that inhibit splicing have cytotoxic effects on various tumor cell lines. In this report, we demonstrate that depletion of SNW1, a component of the spliceosome, induces apoptosis in breast cancer cells. Proteomics and biochemical analyses revealed that SNW1 directly associates with other spliceosome components, including EFTUD2 (Snu114) and SNRNP200 (Brr2). The SKIP region of SNW1 interacted with the N-terminus of EFTUD2 as well as two independent regions in the C-terminus of SNRNP200. Similar to SNW1 depletion, knockdown of EFTUD2 increased the numbers of apoptotic cells. Furthermore, we demonstrate that exogenous expression of either the SKIP region of SNW1 or the N-terminus region of EFTUD2 significantly promoted cellular apoptosis. Our results suggest that the inhibition of SNW1 or its associating proteins may be a novel therapeutic strategy for cancer treatment

  17. ATF3, an HTLV-1 bZip factor binding protein, promotes proliferation of adult T-cell leukemia cells

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    Ohshima Koichi

    2011-03-01

    Full Text Available Abstract Background Adult T-cell leukemia (ATL is an aggressive malignancy of CD4+ T-cells caused by human T-cell leukemia virus type 1 (HTLV-1. The HTLV-1 bZIP factor (HBZ gene, which is encoded by the minus strand of the viral genome, is expressed as an antisense transcript in all ATL cases. By using yeast two-hybrid screening, we identified activating transcription factor 3 (ATF3 as an HBZ-interacting protein. ATF3 has been reported to be expressed in ATL cells, but its biological significance is not known. Results Immunoprecipitation analysis confirmed that ATF3 interacts with HBZ. Expression of ATF3 was upregulated in ATL cell lines and fresh ATL cases. Reporter assay revealed that ATF3 could interfere with the HTLV-1 Tax's transactivation of the 5' proviral long terminal repeat (LTR, doing so by affecting the ATF/CRE site, as well as HBZ. Suppressing ATF3 expression inhibited proliferation and strongly reduced the viability of ATL cells. As mechanisms of growth-promoting activity of ATF3, comparative expression profiling of ATF3 knockdown cells identified candidate genes that are critical for the cell cycle and cell death, including cell division cycle 2 (CDC2 and cyclin E2. ATF3 also enhanced p53 transcriptional activity, but this activity was suppressed by HBZ. Conclusions Thus, ATF3 expression has positive and negative effects on the proliferation and survival of ATL cells. HBZ impedes its negative effects, leaving ATF3 to promote proliferation of ATL cells via mechanisms including upregulation of CDC2 and cyclin E2. Both HBZ and ATF3 suppress Tax expression, which enables infected cells to escape the host immune system.

  18. HNRNPLL stabilizes mRNAs for DNA replication proteins and promotes cell cycle progression in colorectal cancer cells.

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    Sakuma, Keiichiro; Sasaki, Eiichi; Kimura, Kenya; Komori, Koji; Shimizu, Yasuhiro; Yatabe, Yasushi; Aoki, Masahiro

    2018-06-05

    HNRNPLL (heterogeneous nuclear ribonucleoprotein L-like), an RNA-binding protein that regulates alternative splicing of pre-mRNAs, has been shown to regulate differentiation of lymphocytes, as well as metastasis of colorectal cancer cells. Here we show that HNRNPLL promotes cell cycle progression and hence proliferation of colorectal cancer cells. Functional annotation analysis of those genes whose expression levels were changed by three-fold or more in RNA sequencing analysis between SW480 cells overexpressing HNRNPLL and those knocked down for HNRNPLL revealed enrichment of DNA replication-related genes by HNRNPLL overexpression. Among 13 genes detected in the DNA replication pathway, PCNA, RFC3, and FEN1 showed reproducible upregulation by HNRNPLL overexpression both at mRNA and protein levels in SW480 and HT29 cells. Importantly, knockdown of any of these genes alone suppressed the proliferation promoting effect induced by HNRNPLL overexpression. RNA-immunoprecipitation assay presented a binding of FLAG-tagged HNRNPLL to mRNA of these genes, and HNRNPLL overexpression significantly suppressed the downregulation of these genes during 12 hours of actinomycin D treatment, suggesting a role of HNRNPLL in mRNA stability. Finally, analysis of a public RNA sequencing dataset of clinical samples suggested a link between overexpression of HNRNPLL and that of PCNA, RFC3, and FEN1. This link was further supported by immunohistochemistry of colorectal cancer clinical samples, whereas expression of CDKN1A, which is known to inhibit the cooperative function of PCNA, RFC3, and FEN1, was negatively associated with HNRNPLL expression. These results indicate that HNRNPLL stabilizes mRNAs encoding regulators of DNA replication and promotes colorectal cancer cell proliferation. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  19. Methods for promoting wound healing and muscle regeneration with the cell signaling protein nell1

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    Culiat, Cymbeline T.

    2018-03-20

    The present invention provides methods for promoting wound healing and treating muscle atrophy in a mammal in need. The method comprises administering to the mammal a Nell1 protein or a Nell1 nucleic acid molecule.

  20. Methods for promoting wound healing and muscle regeneration with the cell signaling protein Nell1

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    Culiat, Cymbeline T [Oak Ridge, TN

    2011-03-22

    The present invention provides methods for promoting wound healing and treating muscle atrophy in a mammal in need. The method comprises administering to the mammal a Nell1 protein or a Nell1 nucleic acid molecule.

  1. Bone morphogenetic protein-7 promotes chondrogenesis in human amniotic epithelial cells.

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    Zhou, Junjie; Yu, Guangrong; Cao, Chengfu; Pang, Jinhui; Chen, Xianqi

    2011-06-01

    Bone morphogenetic proteins (BMPs) play important roles at multiple stages of chondrogenesis. This study was undertaken to investigate the potential role of bone morphogenetic protein-7 (BMP-7) in the differentiation of chondrocytes using tissue engineering techniques. The impact of BMP-7 on human amniotic epithelial cells (hAECs) was tested. The hAECs were treated either with recombinant human BMP-7 cDNA or with transforming growth factor beta 1 (TGF-β1) as a positive control for three weeks in vitro. Cartilaginous differentiation and proliferation were assayed by quantitative RT-PCR, histology, and in situ hybridization. Our results were such that hAECs treated with either BMP-7 or TGF-β1 expressed cartilage markers (aggrecan, Sox9, CEP-68, and type II and X collagens) within three weeks. Compared with a control vector, BMP-7 induced a decrease in type I collagen expression, while the transcription of the cartilage-specific type II collagen remained stable. In induction experiments, BMP-7 transgenic hAECs exhibited the largest amount of matrix synthesis. In conclusion, these data indicate that BMP-7 plays an important role in inducing the production of cartilage by hAECs in vitro. Cartilage differentiation and matrix maturation can be promoted by BMPs in a cartilage engineering paradigm. These properties make BMPs promising tools in the engineering of cartilaginous joint bio-prostheses and as candidate biological agents or genes for cartilage stabilisation.

  2. Members of the heat-shock protein 70 family promote cancer cell growth by distinct mechanisms

    DEFF Research Database (Denmark)

    Rohde, Mikkel; Daugaard, Mads; Jensen, Mette Hartvig

    2005-01-01

    Whereas the stress-inducible heat-shock protein 70 (Hsp70) has gained plenty of attention as a putative target for tumor therapy, little is known about the role of other Hsp70 proteins in cancer. Here we present the first thorough analysis of the expression and function of the cytosolic Hsp70...... proteins in human cancer cells and identify Hsp70-2, a protein essential for spermatogenesis, as an important regulator of cancer cell growth. Targeted knock-down of the individual family members by RNA interference revealed that both Hsp70 and Hsp70-2 were required for cancer cell growth, whereas...

  3. Adipocyte differentiation-related protein promotes lipid accumulation in goat mammary epithelial cells.

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    Shi, H B; Yu, K; Luo, J; Li, J; Tian, H B; Zhu, J J; Sun, Y T; Yao, D W; Xu, H F; Shi, H P; Loor, J J

    2015-10-01

    Milk fat originates from the secretion of cytosolic lipid droplets (CLD) synthesized within mammary epithelial cells. Adipocyte differentiation-related protein (ADRP; gene symbol PLIN2) is a CLD-binding protein that is crucial for synthesis of mature CLD. Our hypothesis was that ADRP regulates CLD production and metabolism in goat mammary epithelial cells (GMEC) and thus plays a role in determining milk fat content. To understand the role of ADRP in ruminant milk fat metabolism, ADRP (PLIN2) was overexpressed or knocked down in GMEC using an adenovirus system. Immunocytochemical staining revealed that ADRP localized to the surface of CLD. Supplementation with oleic acid (OA) enhanced its colocalization with CLD surface and enhanced lipid accumulation. Overexpression of ADRP increased lipid accumulation and the concentration of triacylglycerol in GMEC. In contrast, morphological examination revealed that knockdown of ADRP decreased lipid accumulation even when OA was supplemented. This response was confirmed by the reduction in mass of cellular TG when ADRP was knocked down. The fact that knockdown of ADRP did not completely eliminate lipid accumulation at a morphological level in GMEC without OA suggests that some other compensatory factors may also aid in the process of CLD formation. The ADRP reversed the decrease of CLD accumulation induced by adipose triglyceride lipase. This is highly suggestive of ADRP promoting triacylglycerol stability within CLD by preventing access to adipose triglyceride lipase. Collectively, these data provide direct in vitro evidence that ADRP plays a key role in CLD formation and stability in GMEC. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  4. NEDD 4 binding protein 2-like 1 promotes cancer cell invasion in oral squamous cell carcinoma.

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    Sasahira, Tomonori; Kurihara, Miyako; Nishiguchi, Yukiko; Fujiwara, Rina; Kirita, Tadaaki; Kuniyasu, Hiroki

    2016-08-01

    Head and neck cancer, including oral squamous cell carcinoma, is the sixth most common cancer worldwide. Although cancer cell invasion and metastasis are crucial for tumor progression, detailed molecular mechanisms underlying the invasion and metastasis of oral squamous cell carcinoma are unclear. Comparison of transcriptional profiles using a cDNA microarray demonstrated that N4BP2L1, a novel oncogene expressed by neural precursor cells, is involved in oral squamous cell carcinoma. Expression of N4BP2L1 in oral squamous cell carcinoma is regulated by activation of miR-448 and is higher than in normal oral mucosa. Knockdown of N4BP2L1 and upregulation of miR-448 significantly reduced the invasive potential of oral squamous cell carcinoma cells. We studied N4BP2L1 expression in 187 cases of oral squamous cell carcinoma and found its overexpression to be significantly associated with nodal metastasis (P = 0.0155) and poor prognosis (P = 0.0136). Expression of miR-448 was found to be inversely associated with that of N4BP2L1 (P = 0.0019). Cox proportional hazards analysis identified N4BP2L1 expression as an independent predictor of disease-free survival (P = 0.0349). Our results suggest that N4BP2L1 plays an important role in tumor cell invasion in oral squamous cell carcinoma. Further studies on expression of N4BP2L1 may provide new insight into its function and clarify its potential as biomarker in human oral cancer.

  5. Nat1 promotes translation of specific proteins that induce differentiation of mouse embryonic stem cells.

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    Sugiyama, Hayami; Takahashi, Kazutoshi; Yamamoto, Takuya; Iwasaki, Mio; Narita, Megumi; Nakamura, Masahiro; Rand, Tim A; Nakagawa, Masato; Watanabe, Akira; Yamanaka, Shinya

    2017-01-10

    Novel APOBEC1 target 1 (Nat1) (also known as "p97," "Dap5," and "Eif4g2") is a ubiquitously expressed cytoplasmic protein that is homologous to the C-terminal two thirds of eukaryotic translation initiation factor 4G (Eif4g1). We previously showed that Nat1-null mouse embryonic stem cells (mES cells) are resistant to differentiation. In the current study, we found that NAT1 and eIF4G1 share many binding proteins, such as the eukaryotic translation initiation factors eIF3 and eIF4A and ribosomal proteins. However, NAT1 did not bind to eIF4E or poly(A)-binding proteins, which are critical for cap-dependent translation initiation. In contrast, compared with eIF4G1, NAT1 preferentially interacted with eIF2, fragile X mental retardation proteins (FMR), and related proteins and especially with members of the proline-rich and coiled-coil-containing protein 2 (PRRC2) family. We also found that Nat1-null mES cells possess a transcriptional profile similar, although not identical, to the ground state, which is established in wild-type mES cells when treated with inhibitors of the ERK and glycogen synthase kinase 3 (GSK3) signaling pathways. In Nat1-null mES cells, the ERK pathway is suppressed even without inhibitors. Ribosome profiling revealed that translation of mitogen-activated protein kinase kinase kinase 3 (Map3k3) and son of sevenless homolog 1 (Sos1) is suppressed in the absence of Nat1 Forced expression of Map3k3 induced differentiation of Nat1-null mES cells. These data collectively show that Nat1 is involved in the translation of proteins that are required for cell differentiation.

  6. Quantitative proteomic analysis reveals effects of epidermal growth factor receptor (EGFR) on invasion-promoting proteins secreted by glioblastoma cells.

    Science.gov (United States)

    Sangar, Vineet; Funk, Cory C; Kusebauch, Ulrike; Campbell, David S; Moritz, Robert L; Price, Nathan D

    2014-10-01

    Glioblastoma multiforme is a highly invasive and aggressive brain tumor with an invariably poor prognosis. The overexpression of epidermal growth factor receptor (EGFR) is a primary influencer of invasion and proliferation in tumor cells and the constitutively active EGFRvIII mutant, found in 30-65% of Glioblastoma multiforme, confers more aggressive invasion. To better understand how EGFR contributes to tumor aggressiveness, we investigated the effect of EGFR on the secreted levels of 65 rationally selected proteins involved in invasion. We employed selected reaction monitoring targeted mass spectrometry using stable isotope labeled internal peptide standards to quantity proteins in the secretome from five GBM (U87) isogenic cell lines in which EGFR, EGFRvIII, and/or PTEN were expressed. Our results show that cell lines with EGFR overexpression and constitutive EGFRvIII expression differ remarkably in the expression profiles for both secreted and intracellular signaling proteins, and alterations in EGFR signaling result in reproducible changes in concentrations of secreted proteins. Furthermore, the EGFRvIII-expressing mutant cell line secretes the majority of the selected invasion-promoting proteins at higher levels than other cell lines tested. Additionally, the intracellular and extracellular protein measurements indicate elevated oxidative stress in the EGFRvIII-expressing cell line. In conclusion, the results of our study demonstrate that EGFR signaling has a significant effect on the levels of secreted invasion-promoting proteins, likely contributing to the aggressiveness of Glioblastoma multiforme. Further characterization of these proteins may provide candidates for new therapeutic strategies and targets as well as biomarkers for this aggressive disease. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  7. Epigenetic repression of regulator of G-protein signaling 2 promotes androgen-independent prostate cancer cell growth.

    Science.gov (United States)

    Wolff, Dennis W; Xie, Yan; Deng, Caishu; Gatalica, Zoran; Yang, Mingjie; Wang, Bo; Wang, Jincheng; Lin, Ming-Fong; Abel, Peter W; Tu, Yaping

    2012-04-01

    G-protein-coupled receptor (GPCR)-stimulated androgen-independent activation of androgen receptor (AR) contributes to acquisition of a hormone-refractory phenotype by prostate cancer. We previously reported that regulator of G-protein signaling (RGS) 2, an inhibitor of GPCRs, inhibits androgen-independent AR activation (Cao et al., Oncogene 2006;25:3719-34). Here, we show reduced RGS2 protein expression in human prostate cancer specimens compared to adjacent normal or hyperplastic tissue. Methylation-specific PCR analysis and bisulfite sequencing indicated that methylation of the CpG island in the RGS2 gene promoter correlated with RGS2 downregulation in prostate cancer. In vitro methylation of this promoter suppressed reporter gene expression in transient transfection studies, whereas reversal of this promoter methylation with 5-aza-2'-deoxycytidine (5-Aza-dC) induced RGS2 reexpression in androgen-independent prostate cancer cells and inhibited their growth under androgen-deficient conditions. Interestingly, the inhibitory effect of 5-Aza-dC was significantly reduced by an RGS2-targeted short hairpin RNA, indicating that reexpressed RGS2 contributed to this growth inhibition. Restoration of RGS2 levels by ectopic expression in androgen-independent prostate cancer cells suppressed growth of xenografts in castrated mice. Thus, RGS2 promoter hypermethylation represses its expression and unmasks a latent pathway for AR transactivation in prostate cancer cells. Targeting this reversible process may provide a new strategy for suppressing prostate cancer progression by reestablishing its androgen sensitivity. Copyright © 2011 UICC.

  8. A secreted Salmonella protein induces a proinflammatory response in epithelial cells, which promotes neutrophil migration

    OpenAIRE

    Lee, Catherine A.; Silva, Milton; Siber, Andrew M.; Kelly, Aaron J.; Galyov, Edouard; McCormick, Beth A.

    2000-01-01

    In response to Salmonella typhimurium, the intestinal epithelium generates an intense inflammatory response consisting largely of polymorphonuclear leukocytes (neutrophils, PMN) migrating toward and ultimately across the epithelial monolayer into the intestinal lumen. It has been shown that bacterial-epithelial cell interactions elicit the production of inflammatory regulators that promote transepithelial PMN migration. Although S. typhimurium can enter intestinal ...

  9. Protein disulfide isomerases in the endoplasmic reticulum promote anchorage-independent growth of breast cancer cells.

    Science.gov (United States)

    Wise, Randi; Duhachek-Muggy, Sara; Qi, Yue; Zolkiewski, Michal; Zolkiewska, Anna

    2016-06-01

    Metastatic breast cancer cells are exposed to stress of detachment from the extracellular matrix (ECM). Cultured breast cancer cells that survive this stress and are capable of anchorage-independent proliferation form mammospheres. The purpose of this study was to explore a link between mammosphere growth, ECM gene expression, and the protein quality control system in the endoplasmic reticulum (ER). We compared the mRNA and protein levels of ER folding factors in SUM159PT and MCF10DCIS.com breast cancer cells grown as mammospheres versus adherent conditions. Publicly available gene expression data for mammospheres formed by primary breast cancer cells and for circulating tumor cells (CTCs) were analyzed to assess the status of ECM/ER folding factor genes in clinically relevant samples. Knock-down of selected protein disulfide isomerase (PDI) family members was performed to examine their roles in SUM159PT mammosphere growth. We found that cells grown as mammospheres had elevated expression of ECM genes and ER folding quality control genes. CTC gene expression data for an index patient indicated that upregulation of ECM and ER folding factor genes occurred at the time of acquired therapy resistance and disease progression. Knock-down of PDI, ERp44, or ERp57, three members of the PDI family with elevated protein levels in mammospheres, in SUM159PT cells partially inhibited the mammosphere growth. Thus, breast cancer cell survival and growth under detachment conditions require enhanced assistance of the ER protein folding machinery. Targeting ER folding factors, in particular members of the PDI family, may improve the therapeutic outcomes in metastatic breast cancer.

  10. Ran GTPase protein promotes human pancreatic cancer proliferation by deregulating the expression of Survivin and cell cycle proteins

    International Nuclear Information System (INIS)

    Deng, Lin; Lu, Yuanyuan; Zhao, Xiaodi; Sun, Yi; Shi, Yongquan; Fan, Hongwei; Liu, Changhao; Zhou, Jinfeng; Nie, Yongzhan; Wu, Kaichun; Fan, Daiming; Guo, Xuegang

    2013-01-01

    Highlights: •Overexpression of Ran in pancreatic cancer was correlated with histological grade. •Downregulation of Ran could induce cell apoptosis and inhibit cell proliferation. •The effects were mediated by cell cycle proteins, Survivin and cleaved Caspase-3. -- Abstract: Ran, a member of the Ras GTPase family, has important roles in nucleocytoplasmic transport. Herein, we detected Ran expression in pancreatic cancer and explored its potential role on tumour progression. Overexpressed Ran in pancreatic cancer tissues was found highly correlated with the histological grade. Downregulation of Ran led to significant suppression of cell proliferation, cell cycle arrest at the G1/S phase and induction of apoptosis. In vivo studies also validated that result. Further studies revealed that those effects were at least partly mediated by the downregulation of Cyclin A, Cyclin D1, Cyclin E, CDK2, CDK4, phospho-Rb and Survivin proteins and up regulation of cleaved Caspase-3

  11. Promoting resuscitation of viable but nonculturable cells of Vibrio harveyi by a resuscitation-promoting factor-like protein YeaZ.

    Science.gov (United States)

    Li, Y; Chen, J; Zhao, M; Yang, Z; Yue, L; Zhang, X

    2017-02-01

    To demonstrate the resuscitation-promoting activities of recombinant YeaZ from Vibrio harveyi SF-1. The gene of resuscitation-promoting factor YeaZ was cloned from genomic DNA of V. harveyi SF-1. The gene was expressed in Escherichia coli, and the expressed protein was purified by Ni 2+ -affinity chromatography. A yeaZ mutant was constructed by using the suicide plasmid pNQ705 with homologous recombination. Disruption of yeaZ did not affect cell growth significantly in 2216 E broth at 28°C. The wild-type and mutant viable but nonculturable (VBNC) cells could be resuscitated by temperature upshift method. In addition, the recombinant YeaZ increased the culturable counts from 1·27 × 10 4  CFU per ml and 1·99 × 10 4 CFU per ml to 2·88 × 10 5  CFU per ml and 4·59 × 10 5 CFU per ml, respectively. After the VBNC cells of wild-type and mutant cells were maintained at 4°C for 120 days, no resuscitation was obtained by temperature upshift method, but addition of the recombinant YeaZ promoted the resuscitation of the wild-type and mutant cells, with the culturable cell counts of 1·13 × 10 3 and 1·44 × 10 3 CFU per ml, respectively. Disruption of yeaZ decreased the virulence of V. harveyi in zebrafish. The lethal dose 50% of the yeaZ null mutant was more than 10-fold higher than that of the wild-type cells. The recombinant YeaZ could efficiently promote resuscitation of the wild-type and mutant cells of V. harveyi from VBNC to culturable state. The protein also promoted resuscitation of the VBNC wild-type and mutant cells, which were maintained at 4°C for 120 days and not recovered by temperature upshift method. Disruption of yeaZ decreased the virulence of V. harveyi in zebrafish. Here, we show clear evidence of a resuscitation-promoting factor YeaZ of V. harveyi and the roles in resuscitation of the VBNC cells and its pathogenicity. © 2016 The Society for Applied Microbiology.

  12. Melatonin Promotes Apoptosis of Oxaliplatin-resistant Colorectal Cancer Cells Through Inhibition of Cellular Prion Protein.

    Science.gov (United States)

    Lee, Jun Hee; Yoon, Yeo Min; Han, Yong-Seok; Yun, Chul Won; Lee, Sang Hun

    2018-04-01

    Drug resistance restricts the efficacy of chemotherapy in colorectal cancer. However, the detailed molecular mechanism of drug resistance in colorectal cancer cells remains unclear. The level of cellular prion protein (PrP C ) in oxaliplatin-resistant colorectal cancer (SNU-C5/Oxal-R) cells was assessed. PrP C level in SNU-C5/Oxal-R cells was significantly increased compared to that in wild-type (SNU-C5) cells. Superoxide dismutase and catalase activities were higher in SNU-C5/Oxal-R cells than in SNU-C5 cells. Treatment of SNU-C5/Oxal-R cells with oxaliplatin and melatonin reduced PrP C expression, while suppressing antioxidant enzyme activity and increasing superoxide anion generation. In SNU-C5/Oxal-R cells, endoplasmic reticulum stress and apoptosis were significantly increased following co-treatment with oxaliplatin and melatonin compared to treatment with oxaliplatin alone. Co-treatment with oxaliplatin and melatonin increased endoplasmic reticulum stress in and apoptosis of SNU-C5/Oxal-R cells through inhibition of PrP C , suggesting that PrP C could be a key molecule in oxaliplatin resistance of colorectal cancer cells. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  13. Phage annealing proteins promote oligonucleotide-directed mutagenesis in Escherichia coli and mouse ES cells

    Directory of Open Access Journals (Sweden)

    Muyrers Joep PP

    2003-01-01

    Full Text Available Abstract Background The phage protein pairs, RecE/RecT from Rac or Redα/Redβ from λ, initiate efficient double strand break repair (DSBR in Escherichia coli that has proven very useful for DNA engineering. These phage pairs initiate DSBR either by annealing or by another mechanism that is not defined. Results Here we report that these proteins also mediate single strand oligonucleotide repair (ssOR at high efficiencies. The ssOR activity, unlike DSBR, does not require a phage exonuclease (RecE or Redα but only requires a phage annealing protein (RecT or Redβ. Notably, the P22 phage annealing protein Erf, which does not mediate the same DSBR reactions, also delivers ssOR activity. By altering aspects of the oligonucleotides, we document length and design parameters that affect ssOR efficiency to show a simple relationship to homologies either side of the repair site. Notably, ssOR shows strand bias. Oligonucleotides that can prime lagging strand replication deliver more ssOR than their leading complements. This suggests a model in which the annealing proteins hybridize the oligonucleotides to single stranded regions near the replication fork. We also show that ssOR is a highly efficient way to engineer BACs and can be detected in a eukaryotic cell upon expression of a phage annealing protein. Conclusion Phage annealing proteins can initiate the recombination of single stranded oligonucleotides into endogenous targets in Escherichia coli at very high efficiencies. This expands the repertoire of useful DNA engineering strategies, shows promise for applications in eukaryotic cells, and has implications for the unanswered questions regarding DSBR mediated by RecE/RecT and Redα/Redβ.

  14. ISL1 protein transduction promotes cardiomyocyte differentiation from human embryonic stem cells.

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    Hananeh Fonoudi

    Full Text Available BACKGROUND: Human embryonic stem cells (hESCs have the potential to provide an unlimited source of cardiomyocytes, which are invaluable resources for drug or toxicology screening, medical research, and cell therapy. Currently a number of obstacles exist such as the insufficient efficiency of differentiation protocols, which should be overcome before hESC-derived cardiomyocytes can be used for clinical applications. Although the differentiation efficiency can be improved by the genetic manipulation of hESCs to over-express cardiac-specific transcription factors, these differentiated cells are not safe enough to be applied in cell therapy. Protein transduction has been demonstrated as an alternative approach for increasing the efficiency of hESCs differentiation toward cardiomyocytes. METHODS: We present an efficient protocol for the differentiation of hESCs in suspension by direct introduction of a LIM homeodomain transcription factor, Islet1 (ISL1 recombinant protein into the cells. RESULTS: We found that the highest beating clusters were derived by continuous treatment of hESCs with 40 µg/ml recombinant ISL1 protein during days 1-8 after the initiation of differentiation. The treatment resulted in up to a 3-fold increase in the number of beating areas. In addition, the number of cells that expressed cardiac specific markers (cTnT, CONNEXIN 43, ACTININ, and GATA4 doubled. This protocol was also reproducible for another hESC line. CONCLUSIONS: This study has presented a new, efficient, and reproducible procedure for cardiomyocytes differentiation. Our results will pave the way for scaled up and controlled differentiation of hESCs to be used for biomedical applications in a bioreactor culture system.

  15. Protein arginine methyltransferase 5 functions as an epigenetic activator of the androgen receptor to promote prostate cancer cell growth.

    Science.gov (United States)

    Deng, X; Shao, G; Zhang, H-T; Li, C; Zhang, D; Cheng, L; Elzey, B D; Pili, R; Ratliff, T L; Huang, J; Hu, C-D

    2017-03-02

    Protein arginine methyltransferase 5 (PRMT5) is an emerging epigenetic enzyme that mainly represses transcription of target genes via symmetric dimethylation of arginine residues on histones H4R3, H3R8 and H2AR3. Accumulating evidence suggests that PRMT5 may function as an oncogene to drive cancer cell growth by epigenetic inactivation of several tumor suppressors. Here, we provide evidence that PRMT5 promotes prostate cancer cell growth by epigenetically activating transcription of the androgen receptor (AR) in prostate cancer cells. Knockdown of PRMT5 or inhibition of PRMT5 by a specific inhibitor reduces the expression of AR and suppresses the growth of multiple AR-positive, but not AR-negative, prostate cancer cells. Significantly, knockdown of PRMT5 in AR-positive LNCaP cells completely suppresses the growth of xenograft tumors in mice. Molecular analysis reveals that PRMT5 binds to the proximal promoter region of the AR gene and contributes mainly to the enriched symmetric dimethylation of H4R3 in the same region. Mechanistically, PRMT5 is recruited to the AR promoter by its interaction with Sp1, the major transcription factor responsible for AR transcription, and forms a complex with Brg1, an ATP-dependent chromatin remodeler, on the proximal promoter region of the AR gene. Furthermore, PRMT5 expression in prostate cancer tissues is significantly higher than that in benign prostatic hyperplasia tissues, and PRMT5 expression correlates positively with AR expression at both the protein and mRNA levels. Taken together, our results identify PRMT5 as a novel epigenetic activator of AR in prostate cancer. Given that inhibiting AR transcriptional activity or androgen synthesis remains the major mechanism of action for most existing anti-androgen agents, our findings also raise an interesting possibility that targeting PRMT5 may represent a novel approach for prostate cancer treatment by eliminating AR expression.

  16. Protein Kinase A Activation Promotes Cancer Cell Resistance to Glucose Starvation and Anoikis.

    Directory of Open Access Journals (Sweden)

    Roberta Palorini

    2016-03-01

    Full Text Available Cancer cells often rely on glycolysis to obtain energy and support anabolic growth. Several studies showed that glycolytic cells are susceptible to cell death when subjected to low glucose availability or to lack of glucose. However, some cancer cells, including glycolytic ones, can efficiently acquire higher tolerance to glucose depletion, leading to their survival and aggressiveness. Although increased resistance to glucose starvation has been shown to be a consequence of signaling pathways and compensatory metabolic routes activation, the full repertoire of the underlying molecular alterations remain elusive. Using omics and computational analyses, we found that cyclic adenosine monophosphate-Protein Kinase A (cAMP-PKA axis activation is fundamental for cancer cell resistance to glucose starvation and anoikis. Notably, here we show that such a PKA-dependent survival is mediated by parallel activation of autophagy and glutamine utilization that in concert concur to attenuate the endoplasmic reticulum (ER stress and to sustain cell anabolism. Indeed, the inhibition of PKA-mediated autophagy or glutamine metabolism increased the level of cell death, suggesting that the induction of autophagy and metabolic rewiring by PKA is important for cancer cellular survival under glucose starvation. Importantly, both processes actively participate to cancer cell survival mediated by suspension-activated PKA as well. In addition we identify also a PKA/Src mechanism capable to protect cancer cells from anoikis. Our results reveal for the first time the role of the versatile PKA in cancer cells survival under chronic glucose starvation and anoikis and may be a novel potential target for cancer treatment.

  17. JNK Promotes Epithelial Cell Anoikis by Transcriptional and Post-translational Regulation of BH3-Only Proteins

    Directory of Open Access Journals (Sweden)

    Nomeda Girnius

    2017-11-01

    Full Text Available Summary: Developmental morphogenesis, tissue injury, and oncogenic transformation can cause the detachment of epithelial cells. These cells are eliminated by a specialized form of apoptosis (anoikis. While the processes that contribute to this form of cell death have been studied, the underlying mechanisms remain unclear. Here, we tested the role of the cJUN NH2-terminal kinase (JNK signaling pathway using murine models with compound JNK deficiency in mammary and kidney epithelial cells. These studies demonstrated that JNK is required for efficient anoikis in vitro and in vivo. Moreover, JNK-promoted anoikis required pro-apoptotic members of the BCL2 family of proteins. We show that JNK acts through a BAK/BAX-dependent apoptotic pathway by increasing BIM expression and phosphorylating BMF, leading to death of detached epithelial cells. : Developmental morphogenesis, tissue injury, and oncogenic transformation can cause epithelial cell detachment. These cells are eliminated by a specialized form of apoptosis termed anoikis. Girnius and Davis show that anoikis is mediated by the cJUN NH2-terminal kinase (JNK, which increases BIM expression and phosphorylates BMF to engage BAK/BAX-dependent apoptosis. Keywords: apoptosis, anoikis, epithelial cell, mammary gland, JNK, BAX, BAK, BH3-only protein, BIM, BMF

  18. Penta- and octa-bromodiphenyl ethers promote proinflammatory protein expression in human bronchial epithelial cells in vitro.

    Science.gov (United States)

    Koike, Eiko; Yanagisawa, Rie; Takigami, Hidetaka; Takano, Hirohisa

    2014-03-01

    Polybrominated diphenyl ethers (PBDEs) are widely used as flame retardants in consumer products. Humans can be exposed to PBDEs mainly through the inhalation of air or dust. Thus, PBDEs can affect respiratory and immune systems. In the present study, we investigated whether PBDEs stimulate bronchial epithelial cells. We examined commercial penta-BDE (DE-71), octa-BDE (DE-79), and deca-BDE (DE-83R). Human bronchial epithelial cells (BEAS-2B) were exposed to each PBDE for 24h. Subsequently, the expression of intercellular adhesion molecule-1 (ICAM-1) and proinflammatory cytokines were investigated. DE-71 and DE-79, but not DE-83R, significantly increased the expression of ICAM-1, interleukin-6 (IL-6), and IL-8 in BEAS-2B. Because these remarkable effects were observed with DE-71, we further investigated the underlying intracellular mechanisms. DE-71 promoted epidermal growth factor receptor (EGFR) phosphorylation. Inhibitors of EGFR-selective tyrosine kinase and p38 mitogen-activated protein kinase effectively blocked the increase of IL-6 and IL-8. Furthermore, antagonists of thyroid hormone receptor and aryl hydrocarbon receptor significantly suppressed the increase in IL-6 and/or IL-8 production. In conclusion, penta- and octa-BDE, but not deca-BDE, might promote the expression of proinflammatory proteins in bronchial epithelial cells possibly by activating protein kinases and/or stimulating nuclear receptors related to subsequent activation of transcriptional factors. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. RNA interference-mediated silencing of speckle-type POZ protein promotes apoptosis of renal cell cancer cells.

    Science.gov (United States)

    Liu, Xiaoxia; Sun, Guiling; Sun, Xiuju

    2016-01-01

    This study aimed to investigate the effects of silencing the speckle-type POZ protein (SPOP) gene on renal cell cancer (RCC) cells and to explore its possible mechanism. The A498 and ACHN RCC cells were transfected with small interference RNA (siRNA)-SPOP by lipofection methods. The silencing efficiency was monitored by quantitative real-time polymerase chain reaction and Western blot. The effects of SPOP silencing on cell apoptosis, cell viability, colony formation ability, cell migration ability, and chemosensitivity to Sorafenib were assessed by flow cytometry, an MTT assay, a colony formation assay, a trans-well migration assay, and a CCK-8 assay, respectively. Its effects on the expression of several cytokines were determined by a protein microarray. Relevant signaling pathways were also analyzed. Compared with the control group, the cell apoptosis rate was significantly higher; the cell viability, the colony formation, and migration ability were significantly decreased in the siRNA-SPOP group. The protein microarray screening showed that the expression of vascular endothelial growth factor receptor, matrix metallopeptidase-9, vascular cell adhesion molecule-1, and stromal cell-derived factor-1 in the siRNA group was significantly decreased and that the expression of granulocyte-macrophage colony-stimulating factor and E-cadherin was significantly increased (Pmatrix organization signal pathway. SPOP gene silencing induced cell apoptosis, decreased cell viability, colony formation, and migration ability, and elevated the drug sensitivity in the RCC cells. A possible mechanism is that silencing SPOP induces the differential expression of E-cadherin, vascular endothelial growth factor receptor, matrix metallopeptidase-9, and vascular cell adhesion molecule, which are related to the integrin-mediated cell surface interactions and extracellular matrix organization signaling pathway.

  20. Small molecule kaempferol modulates PDX-1 protein expression and subsequently promotes pancreatic β-cell survival and function via CREB

    Science.gov (United States)

    Zhang, Yanling.; Zhen, Wei.; Maechler, Pierre; Liu, Dongmin

    2013-01-01

    Chronic hyperlipidemia causes β-cell apoptosis and dysfunction, thereby contributing to the pathogenesis of T2D. Thus, searching for agents to promote pancreatic β-cell survival and improve its function could be a promising strategy to prevent and treat T2D. We investigated the effects of kaempferol, a small molecule isolated from ginkgo biloba, on apoptosis and function of β-cells and further determined the mechanism underlying its actions. Kaempferol treatment promoted viability, inhibited apoptosis, and reduced caspase-3 activity in INS-1E cells and human islets chronically exposed to palmitate. In addition, kaempferol prevented the lipotoxicity-induced down-regulation of anti-apoptotic proteins Akt and Bcl-2. The cytoprotective effects of kaempferol were associated with improved insulin secretion, synthesis, and PDX-1 expression. Chronic hyperlipidemia significantly diminished cAMP production, PKA activation, and CREB phosphorylation and its regulated transcriptional activity in β-cells, all of which were restored by kaempferol treatment. Disruption of CREB expression by transfection of CREB siRNA in INS-1E cells or adenoviral transfer of dominant-negative forms of CREB in human islets ablated kaempferol protection of β-cell apoptosis and dysfunction caused by palmitate. Incubation of INS-1E cells or human islets with kaempferol for 48 h induced PDX-1 expression. This effect of kaempferol on PDX-1 expression was not shared by a host of structurally related flavonoid compounds. PDX-1 gene knockdown reduced kaempferol–stimulated cAMP generation and CREB activation in INS-1E cells. These findings demonstrate that kaempferol is a novel survivor factor for pancreatic β-cells via up-regulating the PDX-1/cAMP/PKA/CREB signaling cascade. PMID:22819546

  1. Overexpression of Zwint predicts poor prognosis and promotes the proliferation of hepatocellular carcinoma by regulating cell-cycle-related proteins

    Directory of Open Access Journals (Sweden)

    Ying H

    2018-02-01

    Full Text Available Hanning Ying,1,2 Zhiyao Xu,3 Mingming Chen,1,2 Senjun Zhou,1,2 Xiao Liang,1,2 Xiujun Cai1,2 1Department of General Surgery, 2Key Laboratory of Endoscopic Technique Research of Zhejiang Province, 3Central Lab of Biomedical Research Center, School of Medicine, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou, China Introduction: Zwint, a centromere-complex component required for the mitotic spindle checkpoint, has been reported to be overexpressed in different human cancers, but it has not been studied in human hepatocellular carcinoma (HCC.Materials and methods: The role of Zwint in hepatocellular carcinoma cell proliferation capacities was evaluated by using cell counting kit-8 (CCK8, flow cytometry, clone formation and tumor formation assay in nude mice. Western blot analysis and qPCR assay were performed to assess Zwint interacting with cell-cycle-related proteins.Results: We report that ZWINT mRNA and protein expression were upregulated in HCC samples and cell lines. An independent set of 106 HCC-tissue pairs and corresponding noncancerous tissues was evaluated for Zwint expression using immunohistochemistry, and elevated Zwint expression in HCC tissues was significantly correlated with clinicopathological features, such as tumor size and number. Kaplan–Meier survival and Cox regression analysis revealed that high expression of Zwint was correlated with poor overall survival and a greater tendency for tumor recurrence. Ectopic expression of Zwint promoted HCC-cell proliferation, and Zwint expression affected the expression of several cell-cycle proteins, including PCNA, cyclin B1, Cdc25C and CDK1.Conclusion: Our findings suggest that upregulation of Zwint may contribute to the progression of HCC and may be a prognostic biomarker and potential therapeutic target for treating HCC. Keywords: Zwint, hepatocellular carcinoma, HCC, prognosis, cell proliferation, cell cycle

  2. Anti-citrullinated protein antibodies promote apoptosis of mature human Saos-2 osteoblasts via cell-surface binding to citrullinated heat shock protein 60.

    Science.gov (United States)

    Lu, Ming-Chi; Yu, Chia-Li; Yu, Hui-Chun; Huang, Hsien-Bin; Koo, Malcolm; Lai, Ning-Sheng

    2016-01-01

    We hypothesized that anti-citrullinated protein antibodies (ACPAs) react with osteoblast surface citrullinated proteins and affect cell function, leading to joint damage in patients with rheumatoid arthritis (RA). First, we purified ACPAs by cyclic citrullinated peptide (CCP)-conjugated affinity column chromatography. The cognate antigens of ACPAs on Saos-2 cells, a sarcoma osteogenic cell line generated from human osteoblasts, were probed by ACPAs, and the reactive bands were analyzed using proteomic analyses. We found that ACPAs bind to Saos-2 cell membrane, and several protein candidates, including HSP60, were identified. We then cloned and purified recombinant heat shock protein 60 (HSP60) and citrullinated HSP60 (citHSP60) and investigated the effect of ACPAs on Saos-2 cell. We confirmed that HSP60 obtained from Saos-2 cell membrane were citrullinated and reacted with ACPAs, which induces Saos-2 cells apoptosis via binding to surface-expressed citHSP60 through Toll-like receptor 4 signaling. ACPAs promoted interleukin (IL)-6 and IL-8 expression in Saos-2 cells. Finally, sera from patients with RA and healthy controls were examined for their titers of anti-HSP60 and anti-citHSP60 antibodies using an enzyme-linked immunosorbent assay. The radiographic change in patients with RA was evaluated using the Genant-modified Sharp scoring system. Patients with RA showed higher sera titers of anti-citHSP60, but not anti-HSP60, antibodies when compared with controls. In addition, the anti-citHSP60 level was positively associated with increased joint damage in patients with RA. In conclusion, Saos-2 cell apoptosis was mediated by ACPAs via binding to cell surface-expressed citHSP60 and the titer of anti-citHSP60 in patients with RA positively associated with joint damage. Copyright © 2015 Elsevier GmbH. All rights reserved.

  3. Placenta-specific protein 1 promotes cell proliferation and invasion in non-small cell lung cancer

    Science.gov (United States)

    Yang, Li; Zha, Tian-Qi; He, Xiang; Chen, Liang; Zhu, Quan; Wu, Wei-Bing; Nie, Feng-Qi; Wang, Qian; Zang, Chong-Shuang; Zhang, Mei-Ling; He, Jing; Li, Wei; Jiang, Wen; Lu, Kai-Hua

    2018-01-01

    Pulmonary carcinoma-associated proteins have emerged as crucial players in governing fundamental biological processes such as cell proliferation, apoptosis and metastasis in human cancers. Placenta-specific protein 1 (PLAC1) is a cancer-related protein, which is activated and upregulated in a variety of malignant tissues, including prostate cancer, gastric adenocarcinoma, colorectal, epithelial ovarian and breast cancer. However, its biological role and clinical significance in non-small cell lung cancer (NSCLC) development and progression are still unknown. In the present study, we found that PLAC1 was significantly upregulated in NSCLC tissues, and its expression level was associated with advanced pathological stage and it was also correlated with shorter progression-free survival of lung cancer patients. Furthermore, knockdown of PLAC1 expression by siRNA inhibited cell proliferation, induced apoptosis and impaired invasive ability in NSCLC cells partly via regulation of epithelial-mesenchymal transition (EMT)-related protein expression. Our findings present that increased PLAC1 could be identified as a negative prognostic biomarker in NSCLC and regulate cell proliferation and invasion. Thus, we conclusively demonstrated that PLAC1 plays a key role in NSCLC development and progression, which may provide novel insights on the function of tumor-related gene-driven tumorigenesis. PMID:29138842

  4. Activation of mitochondrial promoter PH-binding protein in a radio-resistant Chinese hamster cell strain associated with Bcl-2

    International Nuclear Information System (INIS)

    Roychoudhury, Paromita; Ghosh, Utpal; Bhattacharyya, Nitai P.; Chaudhuri, Keya

    2006-01-01

    The cellular response to ionizing radiation is mediated by a complex interaction of number of proteins involving different pathways. Previously, we have shown that up regulation of mitochondrial genes ND1, ND4, and COX1 transcribed from the heavy strand promoter (P H ) has been increased in a radio-resistant cell strain designated as M5 in comparison with the parental Chinese hamster V79 cells. These genes are also up regulated in Chinese hamster V79 cells VB13 that express exogenous human Bcl2. In the present study, the expression of the gene ND6 that is expressed from the light strand promoter (P L ) was found to be similar in both the cell lines, as determined by RT-PCR. To test the possibility that this differential expression of mitochondrial genes under these two promoters was mediated by differences in proteins' affinity to interact with these promoters, we have carried out electrophoretic mobility shift assay (EMSA) using mitochondrial cell extracts from these two cell lines. Our result of these experiments revealed that two different proteins formed complex with the synthetic promoters and higher amount of protein from M5 cell extracts interacted with the P H promoter in comparison to that observed with cell extracts from Chinese hamster V79 cells. The promoter-specific differential binding of proteins was also observed in VB13. These results showed that differential mitochondrial gene expression observed earlier in the radio-resistant M5 cells was due to enhanced interaction proteins with the promoters P H and mediated by the expression of Bcl2

  5. miR-367 regulation of DOC-2/DAB2 interactive protein promotes proliferation, migration and invasion of osteosarcoma cells.

    Science.gov (United States)

    Cai, Wei; Jiang, Haitao; Yu, Yifan; Xu, Yong; Zuo, Wenshan; Wang, Shouguo; Su, Zhen

    2017-11-01

    Recently, miR-367 is reported to exert either oncogenic or tumor suppressive effects in human malignancies. Recent study reports that miR-367 is up-regulated in OS tissues and cell lines, and abrogates adriamycin-induced apoptosis. The clinical significance of miR-367 and its function in OS need further investigation. In our study, miR-367 expression in OS was markedly elevated compared with corresponding non-tumor tissues. High miR-367 expression was associated with malignant clinical features and poor prognosis of OS patients. In accordance, the levels of miR-367 were dramatically up-regulated in OS cells. Loss of miR-367 expression in Saos-2 cells obviously inhibited the proliferation, migration and invasion of cancer cells in vitro. Meanwhile, miR-367 restoration promoted these malignant behaviors of MG-63 cells. Mechanistically, miR-367 negatively regulated DOC-2/DAB2 interactive protein (DAB2IP) abundance in OS cells. Hereby, DAB2IP was recognized as a direct target gene of miR-367 in OS. DAB2IP mRNA level was down-regulated and inversely correlated with miR-367 expression in OS specimens. DAB2IP overexpression prohibited proliferation, migration and invasion in Saos-2 cells, while DAB2IP knockdown showed promoting effects on proliferation, migration and invasion of MG-63 cells. Furthermore, the role of miR-367 might be mediated by DAB2IP-regulated phosphorylation of ERK and AKT in OS cells. To conclude, miR-367 may function as a biomarker for prediction of prognosis and a target for OS therapy. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  6. The matricellular protein TSP1 promotes human and mouse endothelial cell senescence through CD47 and Nox1.

    Science.gov (United States)

    Meijles, Daniel N; Sahoo, Sanghamitra; Al Ghouleh, Imad; Amaral, Jefferson H; Bienes-Martinez, Raquel; Knupp, Heather E; Attaran, Shireen; Sembrat, John C; Nouraie, Seyed M; Rojas, Mauricio M; Novelli, Enrico M; Gladwin, Mark T; Isenberg, Jeffrey S; Cifuentes-Pagano, Eugenia; Pagano, Patrick J

    2017-10-17

    Senescent cells withdraw from the cell cycle and do not proliferate. The prevalence of senescent compared to normally functioning parenchymal cells increases with age, impairing tissue and organ homeostasis. A contentious principle governing this process has been the redox theory of aging. We linked matricellular protein thrombospondin 1 (TSP1) and its receptor CD47 to the activation of NADPH oxidase 1 (Nox1), but not of the other closely related Nox isoforms, and associated oxidative stress, and to senescence in human cells and aged tissue. In human endothelial cells, TSP1 promoted senescence and attenuated cell cycle progression and proliferation. At the molecular level, TSP1 increased Nox1-dependent generation of reactive oxygen species (ROS), leading to the increased abundance of the transcription factor p53. p53 mediated a DNA damage response that led to senescence through Rb and p21 cip , both of which inhibit cell cycle progression. Nox1 inhibition blocked the ability of TSP1 to increase p53 nuclear localization and p21 cip abundance and its ability to promote senescence. Mice lacking TSP1 showed decreases in ROS production, p21 cip expression, p53 activity, and aging-induced senescence. Conversely, lung tissue from aging humans displayed increases in the abundance of vascular TSP1, Nox1, p53, and p21 cip Finally, genetic ablation or pharmacological blockade of Nox1 in human endothelial cells attenuated TSP1-mediated ROS generation, restored cell cycle progression, and protected against senescence. Together, our results provide insights into the functional interplay between TSP1 and Nox1 in the regulation of endothelial senescence and suggest potential targets for controlling the aging process at the molecular level. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  7. RNA interference-mediated silencing of speckle-type POZ protein promotes apoptosis of renal cell cancer cells

    Directory of Open Access Journals (Sweden)

    Liu X

    2016-04-01

    Full Text Available Xiaoxia Liu, Guiling Sun, Xiuju Sun Department of Nephrology, Affiliated Hospital of Weifang Medical University, Weifang, People’s Republic of China Abstract: This study aimed to investigate the effects of silencing the speckle-type POZ protein (SPOP gene on renal cell cancer (RCC cells and to explore its possible mechanism. The A498 and ACHN RCC cells were transfected with small interference RNA (siRNA-SPOP by lipofection methods. The silencing efficiency was monitored by quantitative real-time polymerase chain reaction and Western blot. The effects of SPOP silencing on cell apoptosis, cell viability, colony formation ability, cell migration ability, and chemosensitivity to Sorafenib were assessed by flow cytometry, an MTT assay, a colony formation assay, a trans-well migration assay, and a CCK-8 assay, respectively. Its effects on the expression of several cytokines were determined by a protein microarray. Relevant signaling pathways were also analyzed. Compared with the control group, the cell apoptosis rate was significantly higher; the cell viability, the colony formation, and migration ability were significantly decreased in the siRNA-SPOP group. The protein microarray screening showed that the expression of vascular endothelial growth factor receptor, matrix metallopeptidase-9, vascular cell adhesion molecule-1, and stromal cell-derived factor-1 in the siRNA group was significantly decreased and that the expression of granulocyte–macrophage colony-stimulating factor and E-cadherin was significantly increased (P<0.05. The relevant signaling pathways were the integrin-mediated cell surface interactions pathway and extracellular matrix organization signal pathway. SPOP gene silencing induced cell apoptosis, decreased cell viability, colony formation, and migration ability, and elevated the drug sensitivity in the RCC cells. A possible mechanism is that silencing SPOP induces the differential expression of E-cadherin, vascular endothelial

  8. Stromal Adipocyte Enhancer-binding Protein (AEBP1) Promotes Mammary Epithelial Cell Hyperplasia via Proinflammatory and Hedgehog Signaling*

    Science.gov (United States)

    Holloway, Ryan W.; Bogachev, Oleg; Bharadwaj, Alamelu G.; McCluskey, Greg D.; Majdalawieh, Amin F.; Zhang, Lei; Ro, Hyo-Sung

    2012-01-01

    Disruption of mammary stromal-epithelial communication leads to aberrant mammary gland development and induces mammary tumorigenesis. Macrophages have been implicated in carcinogenesis primarily by creating an inflammatory microenvironment, which promotes growth of the adjacent epithelial cells. Adipocyte enhancer-binding protein 1 (AEBP1), a novel proinflammatory mediator, promotes macrophage inflammatory responsiveness by inducing NF-κB activity, which has been implicated in tumor cell growth and survival by aberrant sonic hedgehog (Shh) expression. Here, we show that stromal macrophage AEBP1 overexpression results in precocious alveologenesis in the virgin AEBP1 transgenic (AEBP1TG) mice, and the onset of ductal hyperplasia was accelerated in AEBP1TG mice fed a high fat diet, which induces endogenous AEBP1 expression. Transplantation of AEBP1TG bone marrow cells into non-transgenic (AEBP1NT) mice resulted in alveolar hyperplasia with up-regulation of NF-κB activity and TNFα expression as displayed in the AEBP1TG mammary macrophages and epithelium. Shh expression was induced in AEBP1TG macrophages and RAW264.7 macrophages overexpressing AEBP1. The Shh target genes Gli1 and Bmi1 expression was induced in the AEBP1TG mammary epithelium and HC11 mammary epithelial cells co-cultured with AEBP1TG peritoneal macrophages. The conditioned AEBP1TG macrophage culture media promoted NF-κB activity and survival signal, Akt activation, in HC11 cells, whereas such effects were abolished by TNFα neutralizing antibody treatment. Furthermore, HC11 cells displayed enhanced proliferation in response to AEBP1TG macrophages and their conditioned media. Our findings highlight the role of AEBP1 in the signaling pathways regulating the cross-talk between mammary epithelium and stroma that could predispose the mammary tissue to tumorigenesis. PMID:22995915

  9. Stromal adipocyte enhancer-binding protein (AEBP1) promotes mammary epithelial cell hyperplasia via proinflammatory and hedgehog signaling.

    Science.gov (United States)

    Holloway, Ryan W; Bogachev, Oleg; Bharadwaj, Alamelu G; McCluskey, Greg D; Majdalawieh, Amin F; Zhang, Lei; Ro, Hyo-Sung

    2012-11-09

    Disruption of mammary stromal-epithelial communication leads to aberrant mammary gland development and induces mammary tumorigenesis. Macrophages have been implicated in carcinogenesis primarily by creating an inflammatory microenvironment, which promotes growth of the adjacent epithelial cells. Adipocyte enhancer-binding protein 1 (AEBP1), a novel proinflammatory mediator, promotes macrophage inflammatory responsiveness by inducing NF-κB activity, which has been implicated in tumor cell growth and survival by aberrant sonic hedgehog (Shh) expression. Here, we show that stromal macrophage AEBP1 overexpression results in precocious alveologenesis in the virgin AEBP1 transgenic (AEBP1(TG)) mice, and the onset of ductal hyperplasia was accelerated in AEBP1(TG) mice fed a high fat diet, which induces endogenous AEBP1 expression. Transplantation of AEBP1(TG) bone marrow cells into non-transgenic (AEBP1(NT)) mice resulted in alveolar hyperplasia with up-regulation of NF-κB activity and TNFα expression as displayed in the AEBP1(TG) mammary macrophages and epithelium. Shh expression was induced in AEBP1(TG) macrophages and RAW264.7 macrophages overexpressing AEBP1. The Shh target genes Gli1 and Bmi1 expression was induced in the AEBP1(TG) mammary epithelium and HC11 mammary epithelial cells co-cultured with AEBP1(TG) peritoneal macrophages. The conditioned AEBP1(TG) macrophage culture media promoted NF-κB activity and survival signal, Akt activation, in HC11 cells, whereas such effects were abolished by TNFα neutralizing antibody treatment. Furthermore, HC11 cells displayed enhanced proliferation in response to AEBP1(TG) macrophages and their conditioned media. Our findings highlight the role of AEBP1 in the signaling pathways regulating the cross-talk between mammary epithelium and stroma that could predispose the mammary tissue to tumorigenesis.

  10. The G-protein coupled chemoattractant receptor FPR2 promotes malignant phenotype of human colon cancer cells

    Science.gov (United States)

    Xiang, Yi; Yao, Xiaohong; Chen, Keqiang; Wang, Xiafei; Zhou, Jiamin; Gong, Wanghua; Yoshimura, Teizo; Huang, Jiaqiang; Wang, Rongquan; Wu, Yuzhang; Shi, Guochao; Bian, Xiuwu; Wang, Jiming

    2016-01-01

    The G-protein coupled chemoattractant receptor formylpeptide receptor-2 (FPR2 in human, Fpr2 in mice) is expressed by mouse colon epithelial cells and plays a critical role in mediating mucosal homeostasis and inflammatory responses. However, the biological role of FPR2 in human colon is unclear. Our investigation revealed that a considerable number of human colon cancer cell lines expressed FPR2 and its ligands promoted cell migration and proliferation. Human colon cancer cell lines expressing high levels of FPR2 also formed more rapidly growing tumors in immunocompromised mice as compared with cell lines expressing lower levels of FPR2. Knocking down of FPR2 from colon cancer cell lines highly expressing FPR2 reduced their tumorigenicity. Clinically, FPR2 is more highly expressed in progressive colon cancer, associated with poorer patient prognosis. These results suggest that FPR2 can be high-jacked by colon cancer cells for their growth advantage, thus becoming a potential target for therapeutic development. PMID:27904774

  11. CUB-domain-containing protein 1 overexpression in solid cancers promotes cancer cell growth by activating Src family kinases.

    Science.gov (United States)

    Leroy, C; Shen, Q; Strande, V; Meyer, R; McLaughlin, M E; Lezan, E; Bentires-Alj, M; Voshol, H; Bonenfant, D; Alex Gaither, L

    2015-10-29

    The transmembrane glycoprotein, CUB (complement C1r/C1s, Uegf, Bmp1) domain-containing protein 1 (CDCP1) is overexpressed in several cancer types and is a predictor of poor prognosis for patients on standard of care therapies. Phosphorylation of CDCP1 tyrosine sites is induced upon loss of cell adhesion and is thought to be linked to metastatic potential of tumor cells. Using a tyrosine-phosphoproteomics screening approach, we characterized the phosphorylation state of CDCP1 across a panel of breast cancer cell lines. We focused on two phospho-tyrosine pTyr peptides of CDCP1, containing Tyr707 and Tyr806, which were identified in all six lines, with the human epidermal growth factor 2-positive HCC1954 cells showing a particularly high phosphorylation level. Pharmacological modulation of tyrosine phosphorylation indicated that, the Src family kinases (SFKs) were found to phosphorylate CDCP1 at Tyr707 and Tyr806 and play a critical role in CDCP1 activity. We demonstrated that CDCP1 overexpression in HEK293 cells increases global phosphotyrosine content, promotes anchorage-independent cell growth and activates several SFK members. Conversely, CDCP1 downregulation in multiple solid cancer cell lines decreased both cell growth and SFK activation. Analysis of primary human tumor samples demonstrated a correlation between CDCP1 expression, SFK and protein kinase C (PKC) activity. Taken together, our results suggest that CDCP1 overexpression could be an interesting therapeutic target in multiple solid cancers and a good biomarker to stratify patients who could benefit from an anti-SFK-targeted therapy. Our data also show that multiple tyrosine phosphorylation sites of CDCP1 are important for the functional regulation of SFKs in several tumor types.

  12. SmgGDS is a transient nucleolar protein that protects cells from nucleolar stress and promotes the cell cycle by regulating DREAM complex gene expression.

    Science.gov (United States)

    Gonyo, P; Bergom, C; Brandt, A C; Tsaih, S-W; Sun, Y; Bigley, T M; Lorimer, E L; Terhune, S S; Rui, H; Flister, M J; Long, R M; Williams, C L

    2017-12-14

    The chaperone protein and guanine nucleotide exchange factor SmgGDS (RAP1GDS1) is a key promoter of cancer cell proliferation and tumorigenesis. SmgGDS undergoes nucleocytoplasmic shuttling, suggesting that it has both cytoplasmic and nuclear functions that promote cancer. Previous studies indicate that SmgGDS binds cytoplasmic small GTPases and promotes their trafficking to the plasma membrane. In contrast, little is known about the functions of SmgGDS in the nucleus, or how these nuclear functions might benefit cancer cells. Here we show unique nuclear localization and regulation of gene transcription pathways by SmgGDS. Strikingly, SmgGDS depletion significantly reduces expression of over 600 gene products that are targets of the DREAM complex, which is a transcription factor complex that regulates expression of proteins controlling the cell cycle. The cell cycle regulators E2F1, MYC, MYBL2 (B-Myb) and FOXM1 are among the DREAM targets that are diminished by SmgGDS depletion. E2F1 is well known to promote G1 cell cycle progression, and the loss of E2F1 in SmgGDS-depleted cells provides an explanation for previous reports that SmgGDS depletion characteristically causes a G1 cell cycle arrest. We show that SmgGDS localizes in nucleoli, and that RNAi-mediated depletion of SmgGDS in cancer cells disrupts nucleolar morphology, signifying nucleolar stress. We show that nucleolar SmgGDS interacts with the RNA polymerase I transcription factor upstream binding factor (UBF). The RNAi-mediated depletion of UBF diminishes nucleolar localization of SmgGDS and promotes proteasome-mediated degradation of SmgGDS, indicating that nucleolar sequestration of SmgGDS by UBF stabilizes SmgGDS protein. The ability of SmgGDS to interact with UBF and localize in the nucleolus is diminished by expressing DiRas1 or DiRas2, which are small GTPases that bind SmgGDS and act as tumor suppressors. Taken together, our results support a novel nuclear role for SmgGDS in protecting malignant

  13. Proliferating cell nuclear antigen (PCNA)-associated KIAA0101/PAF15 protein is a cell cycle-regulated anaphase-promoting complex/cyclosome substrate.

    Science.gov (United States)

    Emanuele, Michael J; Ciccia, Alberto; Elia, Andrew E H; Elledge, Stephen J

    2011-06-14

    The anaphase-promoting complex/cyclosome (APC/C) is a cell cycle-regulated E3 ubiquitin ligase that controls the degradation of substrate proteins at mitotic exit and throughout the G1 phase. We have identified an APC/C substrate and cell cycle-regulated protein, KIAA0101/PAF15. PAF15 protein levels peak in the G2/M phase of the cell cycle and drop rapidly at mitotic exit in an APC/C- and KEN-box-dependent fashion. PAF15 associates with proliferating cell nuclear antigen (PCNA), and depletion of PAF15 decreases the number of cells in S phase, suggesting a role for it in cell cycle regulation. Following irradiation, PAF15 colocalized with γH2AX foci at sites of DNA damage through its interaction with PCNA. Finally, PAF15 depletion led to an increase in homologous recombination-mediated DNA repair, and overexpression caused sensitivity to UV-induced DNA damage. We conclude that PAF15 is an APC/C-regulated protein involved in both cell cycle progression and the DNA damage response.

  14. Indomethacin promotes apoptosis in gastric cancer cells through concomitant degradation of Survivin and Aurora B kinase proteins.

    Science.gov (United States)

    Chiou, Shiun-Kwei; Hoa, Neil; Hodges, Amy; Ge, Lishen; Jadus, Martin R

    2014-09-01

    Regular usage of nonsteroidal anti-inflammatory drugs (NSAIDs) is associated with reduced incidence of a variety of cancers. The molecular mechanisms underlying these chemopreventive effects remain poorly understood. This current investigation showed that in gastric cancer cells: (1) Indomethacin treatment enhanced the degradation of chromosomal passenger proteins, Survivin and Aurora B kinase; (2) Indomethacin treatment down-regulated Aurora B kinase activity in a cell cycle-independent fashion; (3) siRNA knockdown of Survivin level promoted Aurora B kinase protein degradation, and vice versa; (4) ectopic overexpression of Survivin blocked reduction of Aurora B kinase level and activity by indomethacin treatment, and vice versa; (5) siRNA knockdown of Aurora B kinase level and AZD1152 inhibition of its activity induced apoptosis, and overexpression of Aurora B kinase inhibited indomethacin-induced apoptosis; (6) indomethacin treatment reduced Aurora B kinase level, coinciding with reduction of Survivin level and induction of apoptosis, in KATO III and HT-29 cells, and in mouse gastric mucosa. A role for Aurora B kinase function in NSAID-induced apoptosis was not previously explored. Thus this report provides better understanding of the molecular mechanisms underlying the anti-cancer effect of NSAIDs by elucidating a significant role for Aurora B kinase in indomethacin-induced apoptosis.

  15. Protein kinase D stabilizes aldosterone-induced ERK1/2 MAP kinase activation in M1 renal cortical collecting duct cells to promote cell proliferation.

    LENUS (Irish Health Repository)

    McEneaney, Victoria

    2010-01-01

    Aldosterone elicits transcriptional responses in target tissues and also rapidly stimulates the activation of protein kinase signalling cascades independently of de novo protein synthesis. Here we investigated aldosterone-induced cell proliferation and extra-cellular regulated kinase 1 and 2 (ERK1\\/2) mitogen activated protein (MAP) kinase signalling in the M1 cortical collecting duct cell line (M1-CCD). Aldosterone promoted the proliferative growth of M1-CCD cells, an effect that was protein kinase D1 (PKD1), PKCdelta and ERK1\\/2-dependent. Aldosterone induced the rapid activation of ERK1\\/2 with peaks of activation at 2 and 10 to 30 min after hormone treatment followed by sustained activation lasting beyond 120 min. M1-CCD cells suppressed in PKD1 expression exhibited only the early, transient peaks in ERK1\\/2 activation without the sustained phase. Aldosterone stimulated the physical association of PKD1 with ERK1\\/2 within 2 min of treatment. The mineralocorticoid receptor (MR) antagonist RU28318 inhibited the early and late phases of aldosterone-induced ERK1\\/2 activation, and also aldosterone-induced proliferative cell growth. Aldosterone induced the sub-cellular redistribution of ERK1\\/2 to the nuclei at 2 min and to cytoplasmic sites, proximal to the nuclei after 30 min. This sub-cellular distribution of ERK1\\/2 was inhibited in cells suppressed in the expression of PKD1.

  16. Y-box-binding protein-1 (YB-1) promotes cell proliferation, adhesion and drug resistance in diffuse large B-cell lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Miao, Xiaobing; Wu, Yaxun [Department of Pathology, Affiliated Cancer Hospital of Nantong University, Nantong 226361, Jiangsu (China); Wang, Yuchan [Department of Pathogen, Medical College, Nantong University, Nantong 226001, Jiangsu (China); Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Nantong University, Nantong 226001, Jiangsu (China); Zhu, Xinghua; Yin, Haibing [Department of Pathology, Affiliated Cancer Hospital of Nantong University, Nantong 226361, Jiangsu (China); He, Yunhua [Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Nantong University, Nantong 226001, Jiangsu (China); Li, Chunsun; Liu, Yushan; Lu, Xiaoyun; Chen, Yali; Shen, Rong [Department of Pathology, Affiliated Cancer Hospital of Nantong University, Nantong 226361, Jiangsu (China); Xu, Xiaohong, E-mail: xuxiaohongnantong@126.com [Department of Oncology, Affiliated Cancer Hospital of Nantong University, Nantong 226361, Jiangsu (China); He, Song, E-mail: hesongnt@126.com [Department of Pathology, Affiliated Cancer Hospital of Nantong University, Nantong 226361, Jiangsu (China)

    2016-08-15

    YB-1 is a multifunctional protein, which has been shown to correlate with resistance to treatment of various tumor types. This study investigated the expression and biologic function of YB-1 in diffuse large B-cell lymphoma (DLBCL). Immunohistochemical analysis showed that the expression statuses of YB-1 and pYB-1{sup S102} were reversely correlated with the clinical outcomes of DLBCL patients. In addition, we found that YB-1 could promote the proliferation of DLBCL cells by accelerating the G1/S transition. Ectopic expression of YB-1 could markedly increase the expression of cell cycle regulators cyclin D1 and cyclin E. Furthermore, we found that adhesion of DLBCL cells to fibronectin (FN) could increase YB-1 phosphorylation at Ser102 and pYB-1{sup S102} nuclear translocation. In addition, overexpression of YB-1 could increase the adhesion of DLBCL cells to FN. Intriguingly, we found that YB-1 overexpression could confer drug resistance through cell-adhesion dependent and independent mechanisms in DLBCL. Silencing of YB-1 could sensitize DLBCL cells to mitoxantrone and overcome cell adhesion-mediated drug resistance (CAM-DR) phenotype in an AKT-dependent manner. - Highlights: • The expression statuses of YB-1 and pYB-1{sup S102} are reversely correlated with outcomes of DLBCL patients. • YB-1 promotes cell proliferation by accelerating G1/S transition in DLBCL. • YB-1 confers drug resistance to mitoxantrone in DLBCL.

  17. Glutamine reduces myocardial cell apoptosis in a rat model of sepsis by promoting expression of heat shock protein 90.

    Science.gov (United States)

    Li, Wanxia; Tao, Shaoyu; Wu, Qinghua; Wu, Tao; Tao, Ran; Fan, Jun

    2017-12-01

    Myocardial cell injury and cardiac myocyte apoptosis are associated with sepsis. Glutamine (Gln) has been reported to repair myocardial cell injury. The aim of this study was to explore the role of Gln on cardiac myocytes in a cecal ligation and puncture (CLP) model of sepsis in Wistar rats. Following induction of sepsis in a CLP rat model, viral encoding heat shock protein 90 (Hsp90) gene and Hsp90dsDNA were designed to express and knockdown Hsp90, respectively. Rat cardiac tissues were examined histologically, and apoptosis was detected by terminal deoxynucleotidyl transferase dUTP nick end labeling staining. The expression of B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X protein, Hsp90, p53 upregulated modulator of apoptosis, and p53 was measured by western blotting and real-time polymerase chain reaction. Caspase-3, caspase-8, and caspase-9 were detected by enzyme-linked immunosorbent assay. Rat cardiac myocyte damage induced by CLP was reduced by Gln treatment and Hsp90 overexpression, and these changes were reversed by Hsp90 knockdown. Bcl-2 expression, Bcl-2-associated X protein, p53, p53 upregulated modulator of apoptosis, caspase-8, caspase-9, and caspase-3 activities were significantly upregulated in the CLP model, which were reduced by Gln treatment and Hsp90 overexpression. Gln reduced apoptosis of cardiac myocytes in a rat model of sepsis, by promoting Hsp90 expression. Further studies are needed to determine the possible therapeutic action of Gln in sepsis in human tissue. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Convergence of bone morphogenetic protein and laminin-1 signaling pathways promotes proliferation and colony formation by fetal mouse pancreatic cells

    International Nuclear Information System (INIS)

    Jiang Fangxu; Harrison, Leonard C.

    2005-01-01

    We previously reported that bone morphogenetic proteins (BMPs), members of the transforming growth factor superfamily, together with the basement membrane glycoprotein laminin-1 (Ln-1), promote proliferation of fetal pancreatic cells and formation of colonies containing peripheral insulin-positive cells. Here, we further investigate the cross-talk between BMP and Ln-1 signals. By RT-PCR, receptors for BMP (BMPR) (excepting BMPR-1B) and Ln-1 were expressed in the fetal pancreas between E13.5 and E17.5. Specific blocking antibodies to BMP-4 and -6 and selective BMP antagonists partially inhibited colony formation by fetal pancreas cells. Colony formation induced by BMP-6 and Ln-1 was completely abolished in a dose-dependent manner by blocking Ln-1 binding to its α 6 integrin and α-dystroglycan receptors or by blocking the Ln-1 signaling molecules, phosphatidyl-inositol-3-kinase (P13K) and MAP kinase kinase-1. These results demonstrate a convergence of BMP and Ln-1 signaling through P13K and MAP kinase pathways to induce proliferation and colony formation in E15.5 fetal mouse pancreatic cells

  19. The stress protein BAG3 stabilizes Mcl-1 protein and promotes survival of cancer cells and resistance to antagonist ABT-737.

    Science.gov (United States)

    Boiani, Mariana; Daniel, Cristina; Liu, Xueyuan; Hogarty, Michael D; Marnett, Lawrence J

    2013-03-08

    Members of the Bcl-2 family of proteins are important inhibitors of apoptosis in human cancer and are targets for novel anticancer agents such as the Bcl-2 antagonists, ABT-263 (Navitoclax), and its analog ABT-737. Unlike Bcl-2, Mcl-1 is not antagonized by ABT-263 or ABT-737 and is considered to be a major factor in resistance. Also, Mcl-1 exhibits differential regulation when compared with other Bcl-2 family members and is a target for anticancer drug discovery. Here, we demonstrate that BAG3, an Hsp70 co-chaperone, protects Mcl-1 from proteasomal degradation, thereby promoting its antiapoptotic activity. Using neuroblastoma cell lines, with a defined Bcl-2 family dependence, we found that BAG3 expression correlated with Mcl-1 dependence and ABT-737 resistance. RNA silencing of BAG3 led to a marked reduction in Mcl-1 protein levels and overcame ABT-737 resistance in Mcl-1-dependent cells. In ABT-737-resistant cells, Mcl-1 co-immunoprecipitated with BAG3, and loss of Mcl-1 after BAG3 silencing was prevented by proteasome inhibition. BAG3 and Mcl-1 were co-expressed in a panel of diverse cancer cell lines resistant to ABT-737. Silencing BAG3 reduced Mcl-1 protein levels and overcame ABT-737 resistance in several of the cell lines, including triple-negative breast cancer (MDA-MB231) and androgen receptor-negative prostate cancer (PC3) cells. These studies identify BAG3-mediated Mcl-1 stabilization as a potential target for cancer drug discovery.

  20. The Stress Protein BAG3 Stabilizes Mcl-1 Protein and Promotes Survival of Cancer Cells and Resistance to Antagonist ABT-737*

    Science.gov (United States)

    Boiani, Mariana; Daniel, Cristina; Liu, Xueyuan; Hogarty, Michael D.; Marnett, Lawrence J.

    2013-01-01

    Members of the Bcl-2 family of proteins are important inhibitors of apoptosis in human cancer and are targets for novel anticancer agents such as the Bcl-2 antagonists, ABT-263 (Navitoclax), and its analog ABT-737. Unlike Bcl-2, Mcl-1 is not antagonized by ABT-263 or ABT-737 and is considered to be a major factor in resistance. Also, Mcl-1 exhibits differential regulation when compared with other Bcl-2 family members and is a target for anticancer drug discovery. Here, we demonstrate that BAG3, an Hsp70 co-chaperone, protects Mcl-1 from proteasomal degradation, thereby promoting its antiapoptotic activity. Using neuroblastoma cell lines, with a defined Bcl-2 family dependence, we found that BAG3 expression correlated with Mcl-1 dependence and ABT-737 resistance. RNA silencing of BAG3 led to a marked reduction in Mcl-1 protein levels and overcame ABT-737 resistance in Mcl-1-dependent cells. In ABT-737-resistant cells, Mcl-1 co-immunoprecipitated with BAG3, and loss of Mcl-1 after BAG3 silencing was prevented by proteasome inhibition. BAG3 and Mcl-1 were co-expressed in a panel of diverse cancer cell lines resistant to ABT-737. Silencing BAG3 reduced Mcl-1 protein levels and overcame ABT-737 resistance in several of the cell lines, including triple-negative breast cancer (MDA-MB231) and androgen receptor-negative prostate cancer (PC3) cells. These studies identify BAG3-mediated Mcl-1 stabilization as a potential target for cancer drug discovery. PMID:23341456

  1. Angiopoietin-like protein 3 promotes preservation of stemness during ex vivo expansion of murine hematopoietic stem cells.

    Science.gov (United States)

    Farahbakhshian, Elnaz; Verstegen, Monique M; Visser, Trudi P; Kheradmandkia, Sima; Geerts, Dirk; Arshad, Shazia; Riaz, Noveen; Grosveld, Frank; van Til, Niek P; Meijerink, Jules P P

    2014-01-01

    Allogeneic hematopoietic stem cell (HSC) transplantations from umbilical cord blood or autologous HSCs for gene therapy purposes are hampered by limited number of stem cells. To test the ability to expand HSCs in vitro prior to transplantation, two growth factor cocktails containing stem cell factor, thrombopoietin, fms-related tyrosine kinase-3 ligand (STF) or stem cell factor, thrombopoietin, insulin-like growth factor-2, fibroblast growth factor-1 (STIF) either with or without the addition of angiopoietin-like protein-3 (Angptl3) were used. Culturing HSCs in STF and STIF media for 7 days expanded long-term repopulating stem cells content in vivo by ∼6-fold and ∼10-fold compared to freshly isolated stem cells. Addition of Angptl3 resulted in increased expansion of these populations by ∼17-fold and ∼32-fold, respectively, and was further supported by enforced expression of Angptl3 in HSCs through lentiviral transduction that also promoted HSC expansion. As expansion of highly purified lineage-negative, Sca-1+, c-Kit+ HSCs was less efficient than less pure lineage-negative HSCs, Angptl3 may have a direct effect on HCS but also an indirect effect on accessory cells that support HSC expansion. No evidence for leukemia or toxicity was found during long-term follow up of mice transplanted with ex vivo expanded HSCs or manipulated HSC populations that expressed Angptl3. We conclude that the cytokine combinations used in this study to expand HSCs ex vivo enhances the engraftment in vivo. This has important implications for allogeneic umbilical cord-blood derived HSC transplantations and autologous HSC applications including gene therapy.

  2. Tumor-promoting function and prognostic significance of the RNA-binding protein T-cell intracellular antigen-1 in esophageal squamous cell carcinoma.

    Science.gov (United States)

    Hamada, Junichi; Shoda, Katsutoshi; Masuda, Kiyoshi; Fujita, Yuji; Naruto, Takuya; Kohmoto, Tomohiro; Miyakami, Yuko; Watanabe, Miki; Kudo, Yasusei; Fujiwara, Hitoshi; Ichikawa, Daisuke; Otsuji, Eigo; Imoto, Issei

    2016-03-29

    T-cell intracellular antigen-1 (TIA1) is an RNA-binding protein involved in many regulatory aspects of mRNA metabolism. Here, we report previously unknown tumor-promoting activity of TIA1, which seems to be associated with its isoform-specific molecular distribution and regulation of a set of cancer-related transcripts, in esophageal squamous cell carcinoma (ESCC). Immunohistochemical overexpression of TIA1 ectopically localized in the cytoplasm of tumor cells was an independent prognosticator for worse overall survival in a cohort of 143 ESCC patients. Knockdown of TIA1 inhibited proliferation of ESCC cells. By exogenously introducing each of two major isoforms, TIA1a and TIA1b, only TIA1a, which was localized to both the nucleus and cytoplasm, promoted anchorage-dependent and anchorage-independent ESCC cell proliferation. Ribonucleoprotein immunoprecipitation, followed by microarray analysis or massive-parallel sequencing, identified a set of TIA1-binding mRNAs, including SKP2 and CCNA2. TIA1 increased SKP2 and CCNA2 protein levels through the suppression of mRNA decay and translational induction, respectively. Our findings uncover a novel oncogenic function of TIA1 in esophageal tumorigenesis, and implicate its use as a marker for prognostic evaluation and as a therapeutic target in ESCC.

  3. Adhesion and degranulation promoting adapter protein (ADAP is a central hub for phosphotyrosine-mediated interactions in T cells.

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    Marc Sylvester

    Full Text Available TCR stimulation leads to an increase in cellular adhesion among other outcomes. The adhesion and degranulation promoting adapter protein (ADAP is known to be rapidly phosphorylated after T cell stimulation and relays the TCR signal to adhesion molecules of the integrin family. While three tyrosine phosphorylation sites have been characterized biochemically, the binding capabilities and associated functions of several other potential phosphotyrosine motifs remain unclear. Here, we utilize in vitro phosphorylation and mass spectrometry to map novel phosphotyrosine sites in the C-terminal part of human ADAP (486-783. Individual tyrosines were then mutated to phenylalanine and their relevance for cellular adhesion and migration was tested experimentally. Functionally important tyrosine residues include two sites within the folded hSH3 domains of ADAP and two at the C-terminus. Furthermore, using a peptide pulldown approach in combination with stable isotope labeling in cell culture (SILAC we identified SLP-76, PLCgamma, PIK3R1, Nck, CRK, Gads, and RasGAP as phospho-dependent binding partners of a central YDDV motif of ADAP. The phosphorylation-dependent interaction between ADAP and Nck was confirmed by yeast two-hybrid analysis, immunoprecipitation and binary pulldown experiments, indicating that ADAP directly links integrins to modulators of the cytoskeleton independent of SLP-76.

  4. Efficiently engineered cell sheet using a complex of polyethylenimine–alginate nanocomposites plus bone morphogenetic protein 2 gene to promote new bone formation

    Science.gov (United States)

    Jin, Han; Zhang, Kai; Qiao, Chunyan; Yuan, Anliang; Li, Daowei; Zhao, Liang; Shi, Ce; Xu, Xiaowei; Ni, Shilei; Zheng, Changyu; Liu, Xiaohua; Yang, Bai; Sun, Hongchen

    2014-01-01

    Regeneration of large bone defects is a common clinical problem. Recently, stem cell sheet has been an emerging strategy in bone tissue engineering. To enhance the osteogenic potential of stem cell sheet, we fabricated bone morphogenetic protein 2 (BMP-2) gene-engineered cell sheet using a complex of polyethylenimine–alginate (PEI–al) nanocomposites plus human BMP-2 complementary(c)DNA plasmid, and studied its osteogenesis in vitro and in vivo. PEI–al nanocomposites carrying BMP-2 gene could efficiently transfect bone marrow mesenchymal stem cells. The cell sheet was made by culturing the cells in medium containing vitamin C for 10 days. Assays on the cell culture showed that the genetically engineered cells released the BMP-2 for at least 14 days. The expression of osteogenesis-related gene was increased, which demonstrated that released BMP-2 could effectively induce the cell sheet osteogenic differentiation in vitro. To further test the osteogenic potential of the cell sheet in vivo, enhanced green fluorescent protein or BMP-2-producing cell sheets were treated on the cranial bone defects. The results indicated that the BMP-2-producing cell sheet group was more efficient than other groups in promoting bone formation in the defect area. Our results suggested that PEI–al nanocomposites efficiently deliver the BMP-2 gene to bone marrow mesenchymal stem cells and that BMP-2 gene-engineered cell sheet is an effective way for promoting bone regeneration. PMID:24855355

  5. Overexpression of MIP2, a novel WD-repeat protein, promotes proliferation of H9c2 cells

    International Nuclear Information System (INIS)

    Wei, Xing; Song, Lan; Jiang, Lei; Wang, Guiliang; Luo, Xinjing; Zhang, Bin; Xiao, Xianzhong

    2010-01-01

    WD40 repeat proteins have a wide range of diverse biological functions including signal transduction, cell cycle regulation, RNA splicing, and transcription. Myocardial ischemic preconditioning up-regulated protein 2 (MIP2) is a novel member of the WD40 repeat proteins superfamily that contains five WD40 repeats. Little is known about its biological role, and the purpose of this study was to determine the role of MIP2 in regulating cellular proliferation. Transfection and constitutive expression of MIP2 in the rat cardiomyoblast cell line H9c2 results in enhanced growth of those cells as measured by cell number and is proportional to the amount of MIP2 expressed. Overexpression of MIP2 results in a shorter cell cycle, as measured by flow cytometry. Collectively, these data suggest that MIP2 may participate in the progression of cell proliferation in H9c2 cells.

  6. Use of a transfected and amplified Drosophila heat shock promoter construction for inducible production of toxic mouse c-myc proteins in CHO cells

    International Nuclear Information System (INIS)

    Wurm, F.M.; Gwinn, K.A.; Papoulas, O.; Pallavicini, M.; Kingston, R.E.

    1987-01-01

    After transfection and selection with methotrexate, CHO cell lines were established which contained up to 2000 copies of an expression vector for c-myc protein. The vector contained the Drosophila heat shock protein 70 (hsp70) promoter fused with the coding region of the mouse c-myc gene. Incubation of cells for up to 3 hours at 43 0 C resulted in at least a 100-fold induction of recombinant c-myc mRNA. When cells were shifted back to 37 0 C, within 1 to 4 hours, this RNA was translated into protein to yield about 250 μg per 10 9 cells. Cells died a few hours later, suggesting that high concentrations of intracellular c-myc are cytotoxic. 47 refs., 5 figs

  7. Granzyme B Disrupts Central Metabolism and Protein Synthesis in Bacteria to Promote an Immune Cell Death Program.

    Science.gov (United States)

    Dotiwala, Farokh; Sen Santara, Sumit; Binker-Cosen, Andres Ariel; Li, Bo; Chandrasekaran, Sriram; Lieberman, Judy

    2017-11-16

    Human cytotoxic lymphocytes kill intracellular microbes. The cytotoxic granule granzyme proteases released by cytotoxic lymphocytes trigger oxidative bacterial death by disrupting electron transport, generating superoxide anion and inactivating bacterial oxidative defenses. However, they also cause non-oxidative cell death because anaerobic bacteria are also killed. Here, we use differential proteomics to identify granzyme B substrates in three unrelated bacteria: Escherichia coli, Listeria monocytogenes, and Mycobacteria tuberculosis. Granzyme B cleaves a highly conserved set of proteins in all three bacteria, which function in vital biosynthetic and metabolic pathways that are critical for bacterial survival under diverse environmental conditions. Key proteins required for protein synthesis, folding, and degradation are also substrates, including multiple aminoacyl tRNA synthetases, ribosomal proteins, protein chaperones, and the Clp system. Because killer cells use a multipronged strategy to target vital pathways, bacteria may not easily become resistant to killer cell attack. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Construction of a ColD cda Promoter-Based SOS-Green Fluorescent Protein Whole-Cell Biosensor with Higher Sensitivity toward Genotoxic Compounds than Constructs Based on recA, umuDC, or sulA Promoters

    DEFF Research Database (Denmark)

    Norman, Anders; Hansen, Lars Hestbjerg; Sørensen, Søren Johannes

    2005-01-01

    Four different green fluorescent protein (GFP)-based whole-cell biosensors were created based on the DNA damage inducible SOS response of Escherichia coli in order to evaluate the sensitivity of individual SOS promoters toward genotoxic substances. Treatment with the known carcinogen N-methyl-N'-......Four different green fluorescent protein (GFP)-based whole-cell biosensors were created based on the DNA damage inducible SOS response of Escherichia coli in order to evaluate the sensitivity of individual SOS promoters toward genotoxic substances. Treatment with the known carcinogen N......-cell biosensor which is not only able to detect minute levels of genotoxins but, due to its use of the green fluorescent protein, also a reporter system which should be applicable in high-throughput screening assays as well as a wide variety of in situ detection studies....

  9. A mucus adhesion promoting protein, MapA, mediates the adhesion of Lactobacillus reuteri to Caco-2 human intestinal epithelial cells.

    Science.gov (United States)

    Miyoshi, Yukihiro; Okada, Sanae; Uchimura, Tai; Satoh, Eiichi

    2006-07-01

    Lactobacillus reuteri is one of the dominant lactobacilli found in the gastrointestinal tract of various animals. A surface protein of L. reuteri 104R, mucus adhesion promoting protein (MapA), is considered to be an adhesion factor of this strain. We investigated the relation between MapA and adhesion of L. reuteri to human intestinal (Caco-2) cells. Quantitative analysis of the adhesion of L. reuteri strains to Caco-2 cells showed that various L. reuteri strains bind not only to mucus but also to intestinal epithelial cells. In addition, purified MapA bound to Caco-2 cells, and this binding inhibited the adhesion of L. reuteri in a concentration-dependent manner. Based on these observations, the adhesion of L. reuteri appears due to the binding of MapA to receptor-like molecules on Caco-2 cells. Further, far-western analysis indicated the existence of multiple receptor-like molecules in Caco-2 cells.

  10. Infection of epithelial cells with dengue virus promotes the expression of proteins favoring the replication of certain viral strains.

    Science.gov (United States)

    Martínez-Betancur, Viviana; Marín-Villa, Marcel; Martínez-Gutierrez, Marlén

    2014-08-01

    Dengue virus (DENV) is the causative agent of dengue and severe dengue. To understand better the dengue virus-host interaction, it is important to determine how the expression of cellular proteins is modified due to infection. Therefore, a comparison of protein expression was conducted in Vero cells infected with two different DENV strains, both serotype 2: DENV-2/NG (associated with dengue) and DENV-2/16681 (associated with severe dengue). The viability of the infected cells was determined, and neither strain induced cell death at 48 hr. In addition, the viral genomes and infectious viral particles were quantified, and the genome of the DENV-2/16681 strain was determined to have a higher replication rate compared with the DENV-2/NG strain. Finally, the proteins from infected and uninfected cultures were separated using two-dimensional gel electrophoresis, and the differentially expressed proteins were identified by mass spectrometry. Compared with the uninfected controls, the DENV-2/NG- and DENV-2/16681-infected cultures had five and six differentially expressed proteins, respectively. The most important results were observed when the infected cultures were compared to each other (DENV-2/NG vs. DENV-2/16681), and 18 differentially expressed proteins were identified. Based on their cellular functions, many of these proteins were linked to the increase in the replication efficiency of DENV. Among the proteins were calreticulin, acetyl coenzyme A, acetyl transferase, and fatty acid-binding protein. It was concluded that the infection of Vero cells with DENV-2/NG or DENV-2/16681 differentially modifies the expression of certain proteins, which can, in turn, facilitate infection. © 2013 Wiley Periodicals, Inc.

  11. Several adaptor proteins promote intracellular localisation of the transporter MRP4/ABCC4 in platelets and haematopoietic cells.

    Science.gov (United States)

    Schaletzki, Yvonne; Kromrey, Marie-Luise; Bröderdorf, Susanne; Hammer, Elke; Grube, Markus; Hagen, Paul; Sucic, Sonja; Freissmuth, Michael; Völker, Uwe; Greinacher, Andreas; Rauch, Bernhard H; Kroemer, Heyo K; Jedlitschky, Gabriele

    2017-01-05

    The multidrug resistance protein 4 (MRP4/ABCC4) has been identified as an important transporter for signalling molecules including cyclic nucleotides and several lipid mediators in platelets and may thus represent a novel target to interfere with platelet function. Besides its localisation in the plasma membrane, MRP4 has been also detected in the membrane of dense granules in resting platelets. In polarised cells it is localised at the basolateral or apical plasma membrane. To date, the mechanism of MRP4 trafficking has not been elucidated; protein interactions may regulate both the localisation and function of this transporter. We approached this issue by searching for interacting proteins by in vitro binding assays, followed by immunoblotting and mass spectrometry, and by visualising their co-localisation in platelets and haematopoietic cells. We identified the PDZ domain containing scaffold proteins ezrin-binding protein 50 (EBP50/NHERF1), postsynaptic density protein 95 (PSD95), and sorting nexin 27 (SNX27), but also the adaptor protein complex 3 subunit β3A (AP3B1) and the heat shock protein HSP90 as putative interaction partners of MRP4. The knock-down of SNX27, PSD95, and AP3B1 by siRNA in megakaryoblastic leukaemia cells led to a redistribution of MRP4 from intracellular structures to the plasma membrane. Inhibition of HSP90 led to a diminished expression and retention of MRP4 in the endoplasmic reticulum. These results indicate that MRP4 localisation and function are regulated by multiple protein interactions. Changes in the adaptor proteins can hence lead to altered localisation and function of the transporter.

  12. Receptor interactive protein kinase 3 promotes Cisplatin-triggered necrosis in apoptosis-resistant esophageal squamous cell carcinoma cells.

    Directory of Open Access Journals (Sweden)

    Yang Xu

    Full Text Available Cisplatin-based chemotherapy is currently the standard treatment for locally advanced esophageal cancer. Cisplatin has been shown to induce both apoptosis and necrosis in cancer cells, but the mechanism by which programmed necrosis is induced remains unknown. In this study, we provide evidence that cisplatin induces necrotic cell death in apoptosis-resistant esophageal cancer cells. This cell death is dependent on RIPK3 and on necrosome formation via autocrine production of TNFα. More importantly, we demonstrate that RIPK3 is necessary for cisplatin-induced killing of esophageal cancer cells because inhibition of RIPK1 activity by necrostatin or knockdown of RIPK3 significantly attenuates necrosis and leads to cisplatin resistance. Moreover, microarray analysis confirmed an anti-apoptotic molecular expression pattern in esophageal cancer cells in response to cisplatin. Taken together, our data indicate that RIPK3 and autocrine production of TNFα contribute to cisplatin sensitivity by initiating necrosis when the apoptotic pathway is suppressed or absent in esophageal cancer cells. These data provide new insight into the molecular mechanisms underlying cisplatin-induced necrosis and suggest that RIPK3 is a potential marker for predicting cisplatin sensitivity in apoptosis-resistant and advanced esophageal cancer.

  13. Recruitment of focal adhesion kinase and paxillin to β1 integrin promotes cancer cell migration via mitogen activated protein kinase activation

    International Nuclear Information System (INIS)

    Crowe, David L; Ohannessian, Arthur

    2004-01-01

    Integrin-extracellular matrix interactions activate signaling cascades such as mitogen activated protein kinases (MAPK). Integrin binding to extracellular matrix increases tyrosine phosphorylation of focal adhesion kinase (FAK). Inhibition of FAK activity by expression of its carboxyl terminus decreases cell motility, and cells from FAK deficient mice also show reduced migration. Paxillin is a focal adhesion protein which is also phosphorylated on tyrosine. FAK recruitment of paxillin to the cell membrane correlates with Shc phosphorylation and activation of MAPK. Decreased FAK expression inhibits papilloma formation in a mouse skin carcinogenesis model. We previously demonstrated that MAPK activation was required for growth factor induced in vitro migration and invasion by human squamous cell carcinoma (SCC) lines. Adapter protein recruitment to integrin subunits was examined by co-immunoprecipitation in SCC cells attached to type IV collagen or plastic. Stable clones overexpressing FAK or paxillin were created using the lipofection technique. Modified Boyden chambers were used for invasion assays. In the present study, we showed that FAK and paxillin but not Shc are recruited to the β1 integrin cytoplasmic domain following attachment of SCC cells to type IV collagen. Overexpression of either FAK or paxillin stimulated cancer cell migration on type IV collagen and invasion through reconstituted basement membrane which was dependent on MAPK activity. We concluded that recruitment of focal adhesion kinase and paxillin to β1 integrin promoted cancer cell migration via the mitogen activated protein kinase pathway

  14. Recruitment of focal adhesion kinase and paxillin to β1 integrin promotes cancer cell migration via mitogen activated protein kinase activation

    Directory of Open Access Journals (Sweden)

    Ohannessian Arthur

    2004-05-01

    Full Text Available Abstract Background Integrin-extracellular matrix interactions activate signaling cascades such as mitogen activated protein kinases (MAPK. Integrin binding to extracellular matrix increases tyrosine phosphorylation of focal adhesion kinase (FAK. Inhibition of FAK activity by expression of its carboxyl terminus decreases cell motility, and cells from FAK deficient mice also show reduced migration. Paxillin is a focal adhesion protein which is also phosphorylated on tyrosine. FAK recruitment of paxillin to the cell membrane correlates with Shc phosphorylation and activation of MAPK. Decreased FAK expression inhibits papilloma formation in a mouse skin carcinogenesis model. We previously demonstrated that MAPK activation was required for growth factor induced in vitro migration and invasion by human squamous cell carcinoma (SCC lines. Methods Adapter protein recruitment to integrin subunits was examined by co-immunoprecipitation in SCC cells attached to type IV collagen or plastic. Stable clones overexpressing FAK or paxillin were created using the lipofection technique. Modified Boyden chambers were used for invasion assays. Results In the present study, we showed that FAK and paxillin but not Shc are recruited to the β1 integrin cytoplasmic domain following attachment of SCC cells to type IV collagen. Overexpression of either FAK or paxillin stimulated cancer cell migration on type IV collagen and invasion through reconstituted basement membrane which was dependent on MAPK activity. Conclusions We concluded that recruitment of focal adhesion kinase and paxillin to β1 integrin promoted cancer cell migration via the mitogen activated protein kinase pathway.

  15. The secreted protein ANGPTL2 promotes metastasis of osteosarcoma cells through integrin α5β1, p38 MAPK, and matrix metalloproteinases.

    Science.gov (United States)

    Odagiri, Haruki; Kadomatsu, Tsuyoshi; Endo, Motoyoshi; Masuda, Tetsuro; Morioka, Masaki Suimye; Fukuhara, Shigetomo; Miyamoto, Takeshi; Kobayashi, Eisuke; Miyata, Keishi; Aoi, Jun; Horiguchi, Haruki; Nishimura, Naotaka; Terada, Kazutoyo; Yakushiji, Toshitake; Manabe, Ichiro; Mochizuki, Naoki; Mizuta, Hiroshi; Oike, Yuichi

    2014-01-21

    The tumor microenvironment can enhance the invasive capacity of tumor cells. We showed that expression of angiopoietin-like protein 2 (ANGPTL2) in osteosarcoma (OS) cell lines increased and the methylation of its promoter decreased with time when grown as xenografts in mice compared with culture. Compared with cells grown in normal culture conditions, the expression of genes encoding DNA demethylation-related enzymes increased in tumor cells implanted into mice or grown in hypoxic, serum-starved culture conditions. ANGPTL2 expression in OS cell lines correlated with increased tumor metastasis and decreased animal survival by promoting tumor cell intravasation mediated by the integrin α5β1, p38 mitogen-activated protein kinase, and matrix metalloproteinases. The tolloid-like 1 (TLL1) protease cleaved ANGPTL2 into fragments in vitro that did not enhance tumor progression when overexpressed in xenografts. Expression of TLL1 was weak in OS patient tumors, suggesting that ANGPTL2 may not be efficiently cleaved upon secretion from OS cells. These findings demonstrate that preventing ANGPTL2 signaling stimulated by the tumor microenvironment could inhibit tumor cell migration and metastasis.

  16. Down-regulation of Transducin-Like Enhancer of Split protein 4 in hepatocellular carcinoma promotes cell proliferation and epithelial-Mesenchymal-Transition

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Xiao-cai; Xiao, Cui-cui; Li, Hua [Department of Hepatic Surgery, 3rd Affiliated Hospital of Sun Yat-sen University, Guangzhou (China); Guangdong Provincial Key Laboratory of Liver Disease Research, Guangzhou (China); Tai, Yan; Zhang, Qi [Guangdong Provincial Key Laboratory of Liver Disease Research, Guangzhou (China); Yang, Yang, E-mail: yysysu2@163.com [Department of Hepatic Surgery, 3rd Affiliated Hospital of Sun Yat-sen University, Guangzhou (China)

    2016-08-19

    Background: Transducin-Like Enhancer of Split protein 4 (TLE4) has been reported to be involved in some subsets of acute myeloid leukemia and colorectal cancer. In the present study, we aimed to explore the role of TLE4 in tumorigenesis and cancer progression in hepatocellular carcinoma (HCC). Methods: The expression pattern of TLE4 in HCC was determined by Western-blot and qRT-PCR, gain-of-function and loss-of-function was used to explore the biological role of TLE4 in HCC cells. A xenograft model was established to confirm its effects on proliferation. Results: The protein expression levels of TLE4 were significantly down-regulated in HCC tissues compared to matched adjacent normal liver tissues. In vitro, down-regulation of TLE4 in Huh7 or SMMC-7721 promoted cell proliferation and ectopical expression of TLE4 in Hep3B or Bel-7404 suppressed cell proliferation. In addition, the cell colony formation ability was enhanced after down-regulation of TLE4 expression in Huh-7 but suppressed after over-expression in Hep3B. Furthermore, down-regulation of TLE4 increased the cell invasion ability, as well as increased the expression level of Vimentin and decreased that of E-cadherin, indicating a phenotype of epithelial-mesenchymal transition (EMT) in HCC cells. On the contrary, ectopical expression of TLE4 in HCC cells decreased the cell invasion ability and inhibited EMT. In vivo, compared to control group, xenograft tumor volumes were significantly decreased in TLE4 overexpression group. Conclusions: These results demonstrated that TLE4 might play important regulatory roles in cellular proliferation and EMT process in HCC. - Highlights: • TLE4 is significantly down-regulated in HCC samples. • Down regulated of TLE4 in HCC cells promotes cell proliferation. • Down regulated of TLE4 in HCC cells promotes epithelial-to-mesenchymal transition.

  17. Sonic hedgehog protein promotes proliferation and chondrogenic differentiation of bone marrow-derived mesenchymal stem cells in vitro.

    Science.gov (United States)

    Warzecha, Jörg; Göttig, Stephan; Brüning, Christian; Lindhorst, Elmar; Arabmothlagh, Mohammad; Kurth, Andreas

    2006-10-01

    Sonic hedgehog (Shh) protein is known to be an important signaling protein in early embryonic development. Also, Shh is involved in the induction of early cartilaginous differentiation of mesenchymal cells in the limb and in the spine. The impact of Shh on adult stem cells, human bone marrow-derived mesenchymal stem cells (MSCs), was tested. The MSCs were treated either with recombinant Sonic hedgehog protein (r-Shh) or with transforming growth factor-beta 1 (TGF-beta(1)) as a positive control in vitro for 3 weeks. The effects on cartilaginous differentiation and proliferation were assayed. MSCs when treated with either Shh or TGF-beta(1) showed expression of cartilage markers aggrecan, Sox9, CEP-68, and collagen type II and X within 3 weeks. Only r-Shh-treated cells showed a very strong cell proliferation and much higher BrdU incorporation in cell assay systems. These are the first data that indicate an important role of Shh for the induction of cartilage production by MSCs in vitro.

  18. Peroxiredoxin 6 promotes upregulation of the prion protein (PrP in neuronal cells of prion-infected mice

    Directory of Open Access Journals (Sweden)

    Wagner Wibke

    2012-12-01

    Full Text Available Abstract Background It has been widely established that the conversion of the cellular prion protein (PrPC into its abnormal isoform (PrPSc is responsible for the development of transmissible spongiform encephalopathies (TSEs. However, the knowledge of the detailed molecular mechanisms and direct functional consequences within the cell is rare. In this study, we aimed at the identification of deregulated proteins which might be involved in prion pathogenesis. Findings Apolipoprotein E and peroxiredoxin 6 (PRDX6 were identified as upregulated proteins in brains of scrapie-infected mice and cultured neuronal cell lines. Downregulation of PrP gene expression using specific siRNA did not result in a decrease of PRDX6 amounts. Interestingly, selective siRNA targeting PRDX6 or overexpression of PRDX6 controlled PrPC and PrPSc protein amounts in neuronal cells. Conclusions Besides its possible function as a novel marker protein in the diagnosis of TSEs, PDRX6 represents an attractive target molecule in putative pharmacological intervention strategies in the future.

  19. Promoter- and cell-specific epigenetic regulation of CD44, Cyclin D2, GLIPR1 and PTEN by Methyl-CpG binding proteins and histone modifications

    Directory of Open Access Journals (Sweden)

    Schwarzenbach Heidi

    2010-06-01

    Full Text Available Abstract Background The aim of the current study was to analyze the involvement of methyl-CpG binding proteins (MBDs and histone modifications on the regulation of CD44, Cyclin D2, GLIPR1 and PTEN in different cellular contexts such as the prostate cancer cells DU145 and LNCaP, and the breast cancer cells MCF-7. Since global chromatin changes have been shown to occur in tumours and regions of tumour-associated genes are affected by epigenetic modifications, these may constitute important regulatory mechanisms for the pathogenesis of malignant transformation. Methods In DU145, LNCaP and MCF-7 cells mRNA expression levels of CD44, Cyclin D2, GLIPR1 and PTEN were determined by quantitative RT-PCR at the basal status as well as after treatment with demethylating agent 5-aza-2'-deoxycytidine and/or histone deacetylase inhibitor Trichostatin A. Furthermore, genomic DNA was bisulfite-converted and sequenced. Chromatin immunoprecipitation was performed with the stimulated and unstimulated cells using antibodies for MBD1, MBD2 and MeCP2 as well as 17 different histone antibodies. Results Comparison of the different promoters showed that MeCP2 and MBD2a repressed promoter-specifically Cyclin D2 in all cell lines, whereas in MCF-7 cells MeCP2 repressed cell-specifically all methylated promoters. Chromatin immunoprecipitation showed that all methylated promoters associated with at least one MBD. Treatment of the cells by the demethylating agent 5-aza-2'-deoxycytidine (5-aza-CdR caused dissociation of the MBDs from the promoters. Only MBD1v1 bound and repressed methylation-independently all promoters. Real-time amplification of DNA immunoprecipitated by 17 different antibodies showed a preferential enrichment for methylated lysine of histone H3 (H3K4me1, H3K4me2 and H3K4me3 at the particular promoters. Notably, the silent promoters were associated with unmodified histones which were acetylated following treatment by 5-aza-CdR. Conclusions This study is one

  20. Promoter- and cell-specific epigenetic regulation of CD44, Cyclin D2, GLIPR1 and PTEN by Methyl-CpG binding proteins and histone modifications

    International Nuclear Information System (INIS)

    Müller, Imke; Wischnewski, Frank; Pantel, Klaus; Schwarzenbach, Heidi

    2010-01-01

    The aim of the current study was to analyze the involvement of methyl-CpG binding proteins (MBDs) and histone modifications on the regulation of CD44, Cyclin D2, GLIPR1 and PTEN in different cellular contexts such as the prostate cancer cells DU145 and LNCaP, and the breast cancer cells MCF-7. Since global chromatin changes have been shown to occur in tumours and regions of tumour-associated genes are affected by epigenetic modifications, these may constitute important regulatory mechanisms for the pathogenesis of malignant transformation. In DU145, LNCaP and MCF-7 cells mRNA expression levels of CD44, Cyclin D2, GLIPR1 and PTEN were determined by quantitative RT-PCR at the basal status as well as after treatment with demethylating agent 5-aza-2'-deoxycytidine and/or histone deacetylase inhibitor Trichostatin A. Furthermore, genomic DNA was bisulfite-converted and sequenced. Chromatin immunoprecipitation was performed with the stimulated and unstimulated cells using antibodies for MBD1, MBD2 and MeCP2 as well as 17 different histone antibodies. Comparison of the different promoters showed that MeCP2 and MBD2a repressed promoter-specifically Cyclin D2 in all cell lines, whereas in MCF-7 cells MeCP2 repressed cell-specifically all methylated promoters. Chromatin immunoprecipitation showed that all methylated promoters associated with at least one MBD. Treatment of the cells by the demethylating agent 5-aza-2'-deoxycytidine (5-aza-CdR) caused dissociation of the MBDs from the promoters. Only MBD1v1 bound and repressed methylation-independently all promoters. Real-time amplification of DNA immunoprecipitated by 17 different antibodies showed a preferential enrichment for methylated lysine of histone H3 (H3K4me1, H3K4me2 and H3K4me3) at the particular promoters. Notably, the silent promoters were associated with unmodified histones which were acetylated following treatment by 5-aza-CdR. This study is one of the first to reveal the histone code and MBD profile

  1. HCV core protein-induced down-regulation of microRNA-152 promoted aberrant proliferation by regulating Wnt1 in HepG2 cells.

    Directory of Open Access Journals (Sweden)

    Shifeng Huang

    Full Text Available Hepatitis C virus (HCV has been reported to regulate cellular microRNAs (miRNAs. The HCV core protein is considered to be a potential oncoprotein in HCV-related hepatocellular carcinoma (HCV-HCC, but HCV core-regulated miRNAs are largely unknown. Our preliminary experiments revealed significant down-regulation of microRNA-152 (miR-152 by HCV core protein in HepG2 cells. Through target gene prediction softwares, Wnt1 was predicted to be a potential target of miR-152. The present study was initiated to investigate whether miR-152 is aberrantly regulated by the HCV core protein, and involved in the regulation of the aberrant proliferation of HCV-HCC cells.MiR-152 levels were examined by stem-loop real-time RT-PCR (SLqRT-PCR. Cell proliferation was analyzed by MTT and colony formation assay. Cell cycle analysis was performed by flow cytometry. Luciferase reporter assay was conducted to confirm miRNA-target association. Wnt1 expression was determined by real-time qPCR and Western blotting.HCV core protein significantly suppressed miR-152 expression, and led to significant Wnt1 up-regulation with a concomitant aberrantly promoted proliferation. Moreover, we validated that miR-152 inhibition promoted, while miR-152 mimics inhibited cell proliferation. Using, qRT-PCR and western blot, Wnt1 was demonstrated to be regulated by miR-152. Luciferase activity assay showed that while miR-152 mimics significantly reduced the luciferase activity by 83.76% (P<0.0001, miR-152 inhibitor showed no effect on luciferase reporter. Most notably, salvage expression of miR-152 after Ad-HCV core infection for 24 h almost totally reversed the proliferation-promoting effect of the HCV core protein, and meanwhile, reduced the expression of both Wnt1 mRNA and protein to basal levels.These findings provide important evidence that the reduced miR-152 expression by HCV core protein can indirectly lose an inhibitory effect on Wnt1, which might, at least partially lead to cell

  2. Trans-activation of the JC virus late promoter by the tat protein of type 1 human immunodeficiency virus in glial cells

    International Nuclear Information System (INIS)

    Tada, Hiroomi; Lashgari, M.; Amini, S.; Khalili, K.; Rappaport, J.; Wong-Staal, F.

    1990-01-01

    Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system caused by the JC virus (JCV), a human papovavirus. PML is a relatively rare disease seen predominantly in immunocompromised individuals and is a frequent complication observed in AIDS patients. The significantly higher incidence of PML in AIDS patients than in other immunosuppressive disorders has suggested that the presence of human immunodeficiency virus type 1 (HIV-1) in the brain may directly or indirectly contribute to the pathogenesis of this disease. In the present study the authors have examined the expression of the JCV genome in both glial and non-glial cells in the presence of HIV-1 regulatory proteins. They find that the HIV-1-encoded trans-regulatory protein tat increases the basal activity of the JCV late promoter, JCV L , in glial cells. They conclude that the presence of the HIV-1-encoded tat protein may positively affect the JCV lytic cycle in glial cells by stimulating JCV gene expression. The results suggest a mechanism for the relatively high incidence of PML in AIDS patients than in other immunosuppressive disorders. Furthermore, the findings indicate that the HIV-1 regulatory protein tat may stimulate other viral and perhaps cellular promoters, in addition to its own

  3. Hepatitis B virus X protein mutant HBxΔ127 promotes proliferation of hepatoma cells through up-regulating miR-215 targeting PTPRT

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Fabao [Department of Cancer Research, College of Life Sciences, Nankai University, Tianjin 300071 (China); Department of Biochemistry, College of Life Sciences, Nankai University, Tianjin 300071 (China); You, Xiaona [Department of Cancer Research, College of Life Sciences, Nankai University, Tianjin 300071 (China); Chi, Xiumei [Department of Hepatology, The First Hospital, Jilin University, Changchun 130021 (China); Wang, Tao [Department of Cancer Research, College of Life Sciences, Nankai University, Tianjin 300071 (China); Ye, Lihong [Department of Biochemistry, College of Life Sciences, Nankai University, Tianjin 300071 (China); Niu, Junqi, E-mail: junqiniu@yahoo.com.cn [Department of Hepatology, The First Hospital, Jilin University, Changchun 130021 (China); Zhang, Xiaodong, E-mail: zhangxd@nankai.edu.cn [Department of Cancer Research, College of Life Sciences, Nankai University, Tianjin 300071 (China)

    2014-02-07

    Highlights: • Relative to wild type HBx, HBX mutant HBxΔ127 strongly enhances cell proliferation. • Relative to wild type HBx, HBxΔ127 remarkably up-regulates miR-215 in hepatoma cells. • HBxΔ127-elevated miR-215 promotes cell proliferation via targeting PTPRT mRNA. - Abstract: The mutant of virus is a frequent event. Hepatitis B virus X protein (HBx) plays a vital role in the development of hepatocellular carcinoma (HCC). Therefore, the identification of potent mutant of HBx in hepatocarcinogenesis is significant. Previously, we identified a natural mutant of the HBx gene (termed HBxΔ127). Relative to wild type HBx, HBxΔ127 strongly enhanced cell proliferation and migration in HCC. In this study, we aim to explore the mechanism of HBxΔ127 in promotion of proliferation of hepatoma cells. Our data showed that both wild type HBx and HBxΔ127 could increase the expression of miR-215 in hepatoma HepG2 and H7402 cells. However, HBxΔ127 was able to significantly increase miR-215 expression relative to wild type HBx in the cells. We identified that protein tyrosine phosphatase, receptor type T (PTPRT) was one of the target genes of miR-215 through targeting 3′UTR of PTPRT mRNA. In function, miR-215 was able to promote the proliferation of hepatoma cells. Meanwhile anti-miR-215 could partially abolish the enhancement of cell proliferation mediated by HBxΔ127 in vitro. Knockdown of PTPRT by siRNA could distinctly suppress the decrease of cell proliferation mediated by anti-miR-215 in HepG2-XΔ127/H7402-XΔ127 cells. Moreover, we found that anti-miR-215 remarkably inhibited the tumor growth of hepatoma cells in nude mice. Collectively, relative to wild type HBx, HBxΔ127 strongly enhances proliferation of hepatoma cells through up-regulating miR-215 targeting PTPRT. Our finding provides new insights into the mechanism of HBx mutant HBxΔ127 in promotion of proliferation of hepatoma cells.

  4. Activation of protein kinase A and exchange protein directly activated by cAMP promotes adipocyte differentiation of human mesenchymal stem cells

    DEFF Research Database (Denmark)

    Jia, Bingbing; Madsen, Lise; Petersen, Rasmus Koefoed

    2012-01-01

    ) and exchange protein directly activated by cAMP (Epac) in adipocyte conversion of human mesenchymal stem cells derived from adipose tissue (hMADS). We show that cAMP signaling involving the simultaneous activation of both PKA- and Epac-dependent signaling is critical for this process even in the presence......Human mesenchymal stem cells are primary multipotent cells capable of differentiating into several cell types including adipocytes when cultured under defined in vitro conditions. In the present study we investigated the role of cAMP signaling and its downstream effectors, protein kinase A (PKA...... results emphasize the need for cAMP signaling in concert with treatment with a PPARγ or PPARδ agonist to secure efficient adipocyte differentiation of human hMADS mesenchymal stem cells....

  5. Bone morphogenetic protein 4 is overexpressed in and promotes migration and invasion of drug-resistant cancer cells.

    Science.gov (United States)

    Zhou, Kairui; Shi, Xiaoli; Huo, Jinling; Liu, Weihua; Yang, Dongxiao; Yang, Tengjiao; Qin, Tiantian; Wang, Cong

    2017-08-01

    Drug resistance and metastasis significantly hinder chemotherapy and worsen prognoses in cancer. Bone morphogenetic protein 4 (BMP4) belongs to the TGF-β superfamily, has broad biological activities in cell proliferation and cartilage differentiation and is also able to induce migration and invasion. Herein, we investigated the role of BMP4 in the regulation of metastasis in paclitaxel-resistant human esophageal carcinoma EC109 cells (EC109/Taxol) and docetaxel-resistant human gastric cancer MGC803 cells (MGC/Doc). In these drug-resistant cell lines, we found the cell motility was enhanced and BMP4 was up-regulated relative to their respective parental cell lines. Consistent with in vitro assays, migration potential and BMP4 expression were increased in EC109/Taxol nude mice. Furthermore, to address whether BMP4 was required to enhance the metastatic in EC109/Taxol cells, the pharmacological inhibitor of BMP signaling dorsomorphin was used; meanwhile, we found that the migration and invasion abilities were inhibited. Moreover, the canonical Smad signaling pathway was investigated. Overall, our studies demonstrated that BMP4 participates in the regulation of invasion and migration by EC109/Taxol cells, and inhibition of BMP4 may be a novel strategy to interfere with metastasis in cancer therapy. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Forkhead Box Protein C2 Promotes Epithelial-Mesenchymal Transition, Migration and Invasion in Cisplatin-Resistant Human Ovarian Cancer Cell Line (SKOV3/CDDP

    Directory of Open Access Journals (Sweden)

    Chanjuan Li

    2016-08-01

    Full Text Available Background/Aims: Forkhead Box Protein C2 (FOXC2 has been reported to be overexpressed in a variety of human cancers. However, it is unclear whether FOXC2 regulates epithelial-mesenchymal transition (EMT in CDDP-resistant ovarian cancer cells. The aim of this study is to investigate the effects of FOXC2 on EMT and invasive characteristics of CDDP-resistant ovarian cancer cells and the underlying molecular mechanism. Methods: MTT, Western blot, scratch wound healing, matrigel transwell invasion, attachment and detachment assays were performed to detect half maximal inhibitory concentration (IC50 of CDDP, expression of EMT-related proteins and invasive characteristics in CDDP-resistant ovarian cancer cell line (SKOV3/CDDP and its parental cell line (SKOV3. Small hairpin RNA (shRNA was used to knockdown FOXC2 and analyze the effect of FOXC2 knockdown on EMT and invasive characteristics of SKOV3/CDDP cells. Also, the effect of FOXC2 upregulation on EMT and invasive characteristics of SKOV3 cells was analyzed. Furthermore, the molecular mechanism underlying FOXC2-regulating EMT in ovarian cancer cells was determined. Results: Compared with parental SKOV3 cell line, SKOV3/CDDP showed higher IC50 of CDDP (43.26μM (PConclusions: Taken together, these data demonstrate that FOXC2 may be a promoter of EMT phenotype in CDDP-resistant ovarian cancer cells and a potential therapeutic target for the treatment of advanced ovarian cancer.

  7. Intracellular high mobility group B1 protein (HMGB1) represses HIV-1 LTR-directed transcription in a promoter- and cell-specific manner

    International Nuclear Information System (INIS)

    Naghavi, Mojgan H.; Nowak, Piotr; Andersson, Jan; Soennerborg, Anders; Yang Huan; Tracey, Kevin J.; Vahlne, Anders

    2003-01-01

    We investigated whether the high mobility group B 1 (HMGB1), an abundant nuclear protein in all mammalian cells, affects HIV-1 transcription. Intracellular expression of human HMGB1 repressed HIV-1 gene expression in epithelial cells. This inhibitory effect of HMGB1 was caused by repression of long terminal repeat (LTR)-mediated transcription. Other viral promoters/enhancers, including simian virus 40 or cytomegalovirus, were not inhibited by HMGB1. In addition, HMGB1 inhibition of HIV-1 subtype C expression was dependent on the number of NFκB sites in the LTR region. The inhibitory effect of HMGB1 on viral gene expression observed in HeLa cells was confirmed by an upregulation of viral replication in the presence of antisense HMGB1 in monocytic cells. In contrast to what was found in HeLa cells and monocytic cells, endogenous HMGB1 expression did not affect HIV-1 replication in unstimulated Jurkat cells. Thus, intracellular HMGB1 affects HIV-1 LTR-directed transcription in a promoter- and cell-specific manner

  8. Functionalizing Ascl1 with Novel Intracellular Protein Delivery Technology for Promoting Neuronal Differentiation of Human Induced Pluripotent Stem Cells.

    Science.gov (United States)

    Robinson, Meghan; Chapani, Parv; Styan, Tara; Vaidyanathan, Ranjani; Willerth, Stephanie Michelle

    2016-08-01

    Pluripotent stem cells can become any cell type found in the body. Accordingly, one of the major challenges when working with pluripotent stem cells is producing a highly homogenous population of differentiated cells, which can then be used for downstream applications such as cell therapies or drug screening. The transcription factor Ascl1 plays a key role in neural development and previous work has shown that Ascl1 overexpression using viral vectors can reprogram fibroblasts directly into neurons. Here we report on how a recombinant version of the Ascl1 protein functionalized with intracellular protein delivery technology (Ascl1-IPTD) can be used to rapidly differentiate human induced pluripotent stem cells (hiPSCs) into neurons. We first evaluated a range of Ascl1-IPTD concentrations to determine the most effective amount for generating neurons from hiPSCs cultured in serum free media. Next, we looked at the frequency of Ascl1-IPTD supplementation in the media on differentiation and found that one time supplementation is sufficient enough to trigger the neural differentiation process. Ascl1-IPTD was efficiently taken up by the hiPSCs and enabled rapid differentiation into TUJ1-positive and NeuN-positive populations with neuronal morphology after 8 days. After 12 days of culture, hiPSC-derived neurons produced by Ascl1-IPTD treatment exhibited greater neurite length and higher numbers of branch points compared to neurons derived using a standard neural progenitor differentiation protocol. This work validates Ascl1-IPTD as a powerful tool for engineering neural tissue from pluripotent stem cells.

  9. 17β-estradiol-induced ACSL4 protein expression promotes an invasive phenotype in estrogen receptor positive mammary carcinoma cells.

    Science.gov (United States)

    Belkaid, Anissa; Ouellette, Rodney J; Surette, Marc E

    2017-04-01

    Long chain acyl-CoA synthase-4 (ACSL4) expression has been associated with an aggressive phenotype in breast carcinoma cells, whereas its role in ERα-positive breast cancer has not been studied. ACSL4 prefers 20-carbon polyunsaturated fatty acid (PUFA) substrates, and along with other ACSLs has been associated with cellular uptake of exogenous fatty acids. 17β-estradiol induces proliferation and invasive capacities in ERα+ve breast carcinoma that is associated with modifications of cellular lipid metabolism. In this study, treatment of steroid-starved ERα-positive MCF-7 and T47D mammary carcinoma cells with 17β-estradiol resulted in increased cellular uptake of the PUFA arachidonic acid (AA) and eicosapentaenoic acid (EPA), important building blocks for cellular membranes, and increased ACSL4 protein levels. There was no change in the expression of the ACSL1, ACSL3 and ACSL6 protein isotypes. Increased ACSL4 protein expression was not accompanied by changes in ACSL4 mRNA expression, but was associated with a significant increase in the protein half-life compared to untreated cells. ERα silencing reversed the impact of 17β-estradiol on ACSL4 protein levels and half-life. Silencing of ACSL4 eliminated the 17β-estradiol-induced increase in AA and EPA uptake, as well as the 17β-estradiol-induced cell migration, proliferation and invasion capacities. ASCL4 silencing also prevented the 17β-estradiol induced increases in p-Akt and p-GSK3β, and decrease in E-cadherin expression, important events in epithelial to mesenchymal transition. Taken together, these results demonstrate that ACSL4 is a target of 17β-estradiol-stimulated ERα and is required for the cellular uptake of exogenous PUFA and the manifestation of a more malignant phenotype in ERα+ve breast carcinoma cells. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. Efficiently engineered cell sheet using a complex of polyethylenimine–alginate nanocomposites plus bone morphogenetic protein 2 gene to promote new bone formation

    Directory of Open Access Journals (Sweden)

    Jin H

    2014-05-01

    Full Text Available Han Jin,1 Kai Zhang,2 Chunyan Qiao,1 Anliang Yuan,1 Daowei Li,1 Liang Zhao,1 Ce Shi,1 Xiaowei Xu,1 Shilei Ni,1 Changyu Zheng,3 Xiaohua Liu,4 Bai Yang,2 Hongchen Sun11Department of Pathology, School of Stomatology, Jilin University, Changchun, People’s Republic of China; 2State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, People’s Republic of China; 3Molecular Physiology and Therapeutics Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA; 4Department of Biomedical Sciences, Texas A&M University Baylor College of Dentistry, Dallas, TX, USAAbstract: Regeneration of large bone defects is a common clinical problem. Recently, stem cell sheet has been an emerging strategy in bone tissue engineering. To enhance the osteogenic potential of stem cell sheet, we fabricated bone morphogenetic protein 2 (BMP-2 gene-engineered cell sheet using a complex of polyethylenimine–alginate (PEI–al nanocomposites plus human BMP-2 complementary(cDNA plasmid, and studied its osteogenesis in vitro and in vivo. PEI–al nanocomposites carrying BMP-2 gene could efficiently transfect bone marrow mesenchymal stem cells. The cell sheet was made by culturing the cells in medium containing vitamin C for 10 days. Assays on the cell culture showed that the genetically engineered cells released the BMP-2 for at least 14 days. The expression of osteogenesis-related gene was increased, which demonstrated that released BMP-2 could effectively induce the cell sheet osteogenic differentiation in vitro. To further test the osteogenic potential of the cell sheet in vivo, enhanced green fluorescent protein or BMP-2-producing cell sheets were treated on the cranial bone defects. The results indicated that the BMP-2-producing cell sheet group was more efficient than other groups in promoting bone formation in the defect area. Our results suggested that PEI

  11. Cell Cycle-Dependent Recruitment of Polycomb Proteins to the ASNS Promoter Counteracts C/ebp-Mediated Transcriptional Activation in Bombyx mori

    Science.gov (United States)

    Li, Zhiqing; Cheng, Daojun; Mon, Hiroaki; Zhu, Li; Xu, Jian; Tatsuke, Tsuneyuki; Lee, Jae Man; Xia, Qingyou; Kusakabe, Takahiro

    2013-01-01

    Epigenetic modifiers and transcription factors contribute to developmentally programmed gene expression. Here, we establish a functional link between epigenetic regulation by Polycomb group (PcG) proteins and transcriptional regulation by C/ebp that orchestrates the correct expression of Bombyx mori asparagine synthetase (BmASNS), a gene involved in the biosynthesis of asparagine. We show that the cis-regulatory elements of YY1-binding motifs and the CpG island present on the BmASNS promoter are required for the recruitment of PcG proteins and the subsequent deposition of the epigenetic repression mark H3K27me3. RNAi-mediated knockdown of PcG genes leads to derepression of the BmASNS gene via the recruitment of activators, including BmC/ebp, to the promoter. Intriguingly, we find that PcG proteins and BmC/ebp can dynamically modulate the transcriptional output of the BmASNS target in a cell cycle-dependent manner. It will be essential to suppress BmASNS expression by PcG proteins at the G2/M phase of the cell cycle in the presence of BmC/ebp activator. Thus, our results provide a novel insight into the molecular mechanism underlying the recruitment and regulation of the PcG system at a discrete gene locus in Bombyx mori. PMID:23382816

  12. Hepatitis C virus E2 protein promotes human hepatoma cell proliferation through the MAPK/ERK signaling pathway via cellular receptors

    International Nuclear Information System (INIS)

    Zhao Lanjuan; Wang Lu; Ren Hao; Cao Jie; Li Li; Ke Jinshan; Qi Zhongtian

    2005-01-01

    Dysregulation of mitogen-activated protein kinase (MAPK) signaling pathways by various viruses has been shown to be responsible for viral pathogenicity. The molecular mechanism by which hepatitis C virus (HCV) infection caused human liver diseases has been investigated on the basis of abnormal intracellular signal events. Current data are very limited involved in transmembrane signal transduction triggered by HCV E2 protein. Here we explored regulation of the MAPK/extracellular signal-regulated kinase (MAPK/ERK) signaling pathway by E2 expressed in Chinese hamster oval cells. In human hepatoma Huh-7 cells, E2 specifically activated the MAPK/ERK pathway including downstream transcription factor ATF-2 and greatly promoted cell proliferation. CD81 and low density lipoprotein receptor (LDLR) on the cell surface mediated binding of E2 to Huh-7 cells. The MAPK/ERK activation and cell proliferation driven by E2 were suppressed by blockage of CD81 as well as LDLR. Furthermore, pretreatment with an upstream kinase MEK1/2 inhibitor U0126 also impaired the MAPK/ERK activation and cell proliferation induced by E2. Our results suggest that the MAPK/ERK signaling pathway triggered by HCV E2 via its receptors maintains survival and growth of target cells

  13. Tailless-like (TLX) protein promotes neuronal differentiation of dermal multipotent stem cells and benefits spinal cord injury in rats.

    Science.gov (United States)

    Wang, Tao; Ren, Xiaobao; Xiong, Jianqiong; Zhang, Lei; Qu, Jifu; Xu, Wenyue

    2011-04-01

    Spinal cord injury (SCI) remains a formidable challenge in the clinic. In the current study, we examined the effects of the TLX gene on the proliferation and neuronal differentiation of dermal multipotent stem cells (DMSCs) in vitro and the potential of these cells to improve SCI in rats in vivo. DMSCs were stably transfected with TLX-expressing plasmid (TLX/DMSCs). Cell proliferation was examined using the MTT assay, and neuronal differentiation was characterized by morphological observation combined with immunocytochemical/immunofluorescent staining. The in vivo functions of these cells were evaluated by transplantation into rats with SCI, followed by analysis of hindlimb locomotion and post-mortem histology. Compared to parental DMSCs, TLX/DMSCs showed enhanced proliferation and preferential differentiation into NF200-positive neurons in contrast to GFAP-positive astrocytes. When the undifferentiated cells were transplanted into rats with SCI injury, TLX/DMSCs led to significant improvement in locomotor recovery and healing of SCI, as evidenced by reduction in scar tissues and cavities, increase in continuous nerve fibers/axons and enrichment of NF200-positive neurons on the histological level. In conclusion, TLX promotes the proliferation and neuronal differentiation of DMSCs and thus, may serve as a promising therapy for SCI in the clinic.

  14. Cheliensisin A (Chel A) induces apoptosis in human bladder cancer cells by promoting PHLPP2 protein degradation.

    Science.gov (United States)

    Zhang, Ruowen; Che, Xun; Zhang, Jingjie; Li, Yang; Li, Jingxia; Deng, Xu; Zhu, Junlan; Jin, Honglei; Zhao, Qinshi; Huang, Chuanshu

    2016-10-11

    Cheliensisin A (Chel A), a styryl-lactone compound extracted from Goniothalamus cheliensis, is reported to have significant anti-cancer effects in various cancer cells. Here we demonstrated that Chel A treatment resulted in apoptosis and an inhibition of anchorage-independent growth in human bladder cancer T24, T24T and U5637 cells. Mechanistic studies showed that such effect is mediated by PH domain and Leucine rich repeat Protein Phosphatases (PHLPP2) protein. Chel A treatment led to PHLPP2 degradation and subsequently increased in c-Jun phosphorylation. Moreover PHLPP2 degradation could be attenuated by inhibition of autophagy, which was mediated by Beclin 1. Collectively, we discover that Chel A treatment induces Beclin-dependent autophagy, consequently mediates PHLPP2 degradation and JNK/C-Jun phosphorylation and activation, further in turn contributing to apoptosis in human bladder cancer cells. Current studies provide a significant insight into understanding of anticancer effect of Chel A in treatment of human bladder cancer.

  15. The Air Liquid-interface, a Skin Microenvironment, Promotes Growth of Melanoma Cells, but not Their Apoptosis and Invasion, through Activation of Mitogen-activated Protein Kinase

    International Nuclear Information System (INIS)

    Hong Yee, Chong; Aoki, Shigehisa; Uchihashi, Kazuyoshi; Matsunobu, Aki; Yamasaki, Fumio; Misago, Noriyuki; Piao, Meihua; Tetsuji, Uemura; Yonemitsu, Nobuhisa; Sugihara, Hajime; Toda, Shuji

    2010-01-01

    The air-liquid interface (ALI) is a common microenvironment of the skin, but it is unknown whether the ALI affects melanoma cell behaviors. Using a collagen gel invasion assay, immunohistochemistry, and Western blots, here we show that melanoma cell proliferation in cultures with an ALI is higher than melanoma cell proliferation in submerged cultures. Bromodeoxyuridine (BrdU) uptake, an indicator of cell proliferation, of melanoma cells at the ALI was about 3 times that of submerged cells, while ALI and submerged melanoma cells had similar levels of single-stranded DNA (a marker of apoptosis). The ALI enhanced the expression of Raf-1, MEK-1 and pERK-1/2 components of the mitogen-activated protein kinase (MAPK) cascade, in cells more than the submerged condition did. The increases in BrdU uptake and pERK-1/2 expression promoted by ALI was abolished by the MEK inhibitor, PD-98059. ALI-treated and submerged melanoma cells did not infiltrate into the collagen gel, and they showed no significant difference in the expression of the invasion- and motility-related molecules, matrix metalloproteinase-1 and -9, laminin 5, and filamin A. Our data indicate that the ALI, a skin microenvironment, accelerates the growth, but not the apoptosis or invasion, of melanoma cells through MAPK activation

  16. Transactivation of the proenkephalin gene promoter by the Tax sub 1 protein of human T-cell lymphotropic virus type I

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, J.B. (National Heart, Lung, and Blood Inst., Bethesda, MD (United States)); Dave, H.P.G. (National Inst. of Health, Bethesda, MD (United States))

    1992-02-01

    Human T-cell lymphotropic virus type I (HTLV-I), an etiologic agent for adult T-cell leukemia, is strongly associated with certain neurological diseases. The HTLV-I genome encodes a protein, Tax{sub 1}, that transactivates viral gene transcription. CD4-positive T helper lymphocytes express the proenkephalin gene, and enkephalins have been implicated as neuroimmunomodulators. The authors have investigated the effect of Tax{sub 1} on the proenkephalin gene promoter in C6 rat glioma cells and demonstrated its transactivation. Analysis using 5{prime} deletion mutants of the promoter region showed that sequences upstream of base pair - 190 are necessary for maximal transactivation. Forskolin, a cAMP modulator, synergistically increased Tax{sub 1}-mediated transactivation of the proenkephalin promoter. Neither Tax{sub 1} transactivation alone nor Tax{sub 1}/cAMP synergism exclusively involved cAMP-responsive elements. Endogenous proenkephalin gene expression increased in Tax{sub 1}-expressing C6 cells. Since HTLV-I infects lymphocytes, which express proenkephalin mRNA, Tax{sub 1} transregulation of proenkephalin expression may provide bidirectional communication between the nervous and immune systems in HTLV-I-related diseases.

  17. The role of the metastasis promoting protein S100A4 during EMT in mammary gland epithelial cells

    OpenAIRE

    Rognlien, Vibeke Wethe

    2013-01-01

    Master i biomedisin Breast cancer is one of the greatest contributors to mortality among the different cancer types in the female population of the western world each year. An increasing degree of evidence state that the S100A4 protein, which has been identified in several tumors of different origins and has proven to be associated with a poor patient prognosis, might have an important role in a process which induces carcinoma cells of the breast to gain a more motile and invas...

  18. Inhibition of mitogen-activated protein kinase kinase, DNA methyltransferase, and transforming growth factor-β promotes differentiation of human induced pluripotent stem cells into enterocytes.

    Science.gov (United States)

    Kodama, Nao; Iwao, Takahiro; Kabeya, Tomoki; Horikawa, Takashi; Niwa, Takuro; Kondo, Yuki; Nakamura, Katsunori; Matsunaga, Tamihide

    2016-06-01

    We previously reported that small-molecule compounds were effective in generating pharmacokinetically functional enterocytes from human induced pluripotent stem (iPS) cells. In this study, to determine whether the compounds promote the differentiation of human iPS cells into enterocytes, we investigated the effects of a combination of mitogen-activated protein kinase kinase (MEK), DNA methyltransferase (DNMT), and transforming growth factor (TGF)-β inhibitors on intestinal differentiation. Human iPS cells cultured on feeder cells were differentiated into endodermal cells by activin A. These endodermal-like cells were then differentiated into intestinal stem cells by fibroblast growth factor 2. Finally, the cells were differentiated into enterocyte cells by epidermal growth factor and small-molecule compounds. After differentiation, mRNA expression levels and drug-metabolizing enzyme activities were measured. The mRNA expression levels of the enterocyte marker sucrase-isomaltase and the major drug-metabolizing enzyme cytochrome P450 (CYP) 3A4 were increased by a combination of MEK, DNMT, and TGF-β inhibitors. The mRNA expression of CYP3A4 was markedly induced by 1α,25-dihydroxyvitamin D3. Metabolic activities of CYP1A1/2, CYP2B6, CYP2C9, CYP2C19, CYP3A4/5, UDP-glucuronosyltransferase, and sulfotransferase were also observed in the differentiated cells. In conclusion, MEK, DNMT, and TGF-β inhibitors can be used to promote the differentiation of human iPS cells into pharmacokinetically functional enterocytes. Copyright © 2016 The Japanese Society for the Study of Xenobiotics. Published by Elsevier Ltd. All rights reserved.

  19. Small kinetochore associated protein (SKAP promotes UV-induced cell apoptosis through negatively regulating pre-mRNA processing factor 19 (Prp19.

    Directory of Open Access Journals (Sweden)

    Shan Lu

    Full Text Available Apoptosis is a regulated cellular suicide program that is critical for the development and maintenance of healthy tissues. Previous studies have shown that small kinetochore associated protein (SKAP cooperates with kinetochore and mitotic spindle proteins to regulate mitosis. However, the role of SKAP in apoptosis has not been investigated. We have identified a new interaction involving SKAP, and we propose a mechanism through which SKAP regulates cell apoptosis. Our experiments demonstrate that both overexpression and knockdown of SKAP sensitize cells to UV-induced apoptosis. Further study has revealed that SKAP interacts with Pre-mRNA processing Factor 19 (Prp19. We find that UV-induced apoptosis can be inhibited by ectopic expression of Prp19, whereas silencing Prp19 has the opposite effect. Additionally, SKAP negatively regulates the protein levels of Prp19, whereas Prp19 does not alter SKAP expression. Finally, rescue experiments demonstrate that the pro-apoptotic role of SKAP is executed through Prp19. Taken together, these findings suggest that SKAP promotes UV-induced cell apoptosis by negatively regulating the anti-apoptotic protein Prp19.

  20. The 18-kDa translocator protein (TSPO disrupts mammary epithelial morphogenesis and promotes breast cancer cell migration.

    Directory of Open Access Journals (Sweden)

    Xiaoting Wu

    Full Text Available Mitochondria play important roles in cancer progression and have emerged as viable targets for cancer therapy. Increasing levels of the outer mitochondrial membrane protein, 18-kDa translocator protein (TSPO, are associated with advancing breast cancer stage. In particular, higher TSPO levels are found in estrogen receptor (ER-negative breast tumors, compared with ER-positive tumors. In this study, we sought to define the roles of TSPO in the acquisition of breast cancer malignancy. Using a three-dimensional Matrigel culture system, we determined the impact of elevated TSPO levels on mammary epithelial morphogenesis. Our studies demonstrate that stable overexpression of TSPO in mammary epithelial MCF10A acini drives proliferation and provides partial resistance to luminal apoptosis, resulting in enlarged acinar structures with partially filled lumen that resemble early stage breast lesions leading to breast cancer. In breast cancer cell lines, TSPO silencing or TSPO overexpression significantly altered the migratory activity. In addition, we found that combination treatment with the TSPO ligands (PK 11195 or Ro5-4864 and lonidamine, a clinical phase II drug targeting mitochondria, decreased viability of ER-negative breast cancer cell lines. Taken together, these data demonstrate that increases in TSPO levels at different stages of breast cancer progression results in the acquisition of distinct properties associated with malignancy. Furthermore, targeting TSPO, particularly in combination with other mitochondria-targeting agents, may prove useful for the treatment of ER-negative breast cancer.

  1. Corydalis edulis Maxim. Promotes Insulin Secretion via the Activation of Protein Kinase Cs (PKCs) in Mice and Pancreatic β Cells.

    Science.gov (United States)

    Zheng, Jiao; Zhao, Yunfang; Lun, Qixing; Song, Yuelin; Shi, Shepo; Gu, Xiaopan; Pan, Bo; Qu, Changhai; Li, Jun; Tu, Pengfei

    2017-01-16

    Corydalis edulis Maxim., a widely grown plant in China, had been proposed for the treatment for type 2 diabetes mellitus. In this study, we found that C. edulis extract (CE) is protective against diabetes in mice. The treatment of hyperglycemic and hyperlipidemic apolipoprotein E (ApoE)-/- mice with a high dose of CE reduced serum glucose by 28.84% and serum total cholesterol by 17.34% and increased insulin release. We also found that CE significantly enhanced insulin secretion in a glucose-independent manner in hamster pancreatic β cell (HIT-T15). Further investigation revealed that CE stimulated insulin exocytosis by a protein kinase C (PKC)-dependent signaling pathway and that CE selectively activated novel protein kinase Cs (nPKCs) and atypical PKCs (aPKCs) but not conventional PKCs (cPKCs) in HIT-T15 cells. To the best of our knowledge, our study is the first to identify the PKC pathway as a direct target and one of the major mechanisms underlying the antidiabetic effect of CE. Given the good insulinotropic effect of this herbal medicine, CE is a promising agent for the development of new drugs for treating diabetes.

  2. Holliday junction–recognizing protein promotes cell proliferation and correlates with unfavorable clinical outcome of hepatocellular carcinoma

    Directory of Open Access Journals (Sweden)

    Hu B

    2017-05-01

    Full Text Available Baohong Hu,1,2,* Qianli Wang,3,* Yueju Wang,4 Jian Chen,2 Peng Li,2 Mingyong Han1 1Department of Health Care Oncology, East District of Shandong Provincial Hospital of Shandong University, Jinan, 2Department of Medical Oncology, 3Department of Intensive Care Unit, Yantai Yuhuangding Hospital Affiliated to Qingdao University, Yantai, Shandong, 4Department of Geriatrics, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, People’s Republic of China *These authors contributed equally to this work Aim: To investigate the expression and clinical significance of Holliday junction–recognizing protein (HJURP in hepatocellular carcinoma (HCC. Methods: In this study, we detected the expression of HJURP protein in samples of 164 patients with HCC, and based on this, we divided the patients into two cohorts: high expression of HJURP and low expression of HJURP. We analyzed the correlation between HJURP expression and the clinicopathological factors using chi-square test. Survival significance of HJURP was defined by Kaplan–Meier method and log-rank test, and the independent prognostic factors were identified by Cox regression model. Using function assays of HCC cell lines, we investigated the influence of HJURP on the proliferation of HCC cells. Results: In our study, the proportion of patients with high HJURP expression was 25.6%, which was significantly associated with the tumor size and Barcelona clinic liver cancer stage. Univariate analysis confirmed that high HJURP expression was remarkably associated with poorer overall survival rates (P=0.003, as well as tumor number (P=0.016, tumor differentiation (P=0.047, TNM stage (P=0.005, and Barcelona clinic liver cancer stage (P=0.004. Multivariate analysis confirmed that high HJURP expression (P<0.001 acted as an independent prognostic risk factor of unfavorable prognosis. Real-time polymerase chain reaction analysis revealed that the expression of HJURP was significantly higher in

  3. The Src homology 2 protein Shb promotes cell cycle progression in murine hematopoietic stem cells by regulation of focal adhesion kinase activity

    Energy Technology Data Exchange (ETDEWEB)

    Gustafsson, Karin [Department of Medical Cell Biology, Uppsala University, Uppsala 751 23 (Sweden); Heffner, Garrett; Wenzel, Pamela L.; Curran, Matthew [HHMI, Children' s Hospital Boston, Harvard Medical School, Boston, 02115 MA (United States); Grawé, Jan [Department of Genetics and Pathology, Uppsala University, Uppsala 75185 (Sweden); McKinney-Freeman, Shannon L. [Department of Hematology, St. Jude Children' s Research Hospital, Memphis, TN 38105 (United States); Daley, George Q. [HHMI, Children' s Hospital Boston, Harvard Medical School, Boston, 02115 MA (United States); Welsh, Michael, E-mail: michael.welsh@mcb.uu.se [Department of Medical Cell Biology, Uppsala University, Uppsala 751 23 (Sweden)

    2013-07-15

    The widely expressed adaptor protein Shb has previously been reported to contribute to T cell function due to its association with the T cell receptor and furthermore, several of Shb's known interaction partners are established regulators of blood cell development and function. In addition, Shb deficient embryonic stem cells displayed reduced blood cell colony formation upon differentiation in vitro. The aim of the current study was therefore to explore hematopoietic stem and progenitor cell function in the Shb knockout mouse. Shb deficient bone marrow contained reduced relative numbers of long-term hematopoietic stem cells (LT-HSCs) that exhibited lower proliferation rates. Despite this, Shb knockout LT-HSCs responded promptly by entering the cell cycle in response to genotoxic stress by 5-fluorouracil treatment. In competitive LT-HSC transplantations, Shb null cells initially engrafted as well as the wild-type cells but provided less myeloid expansion over time. Moreover, Shb knockout bone marrow cells exhibited elevated basal activities of focal adhesion kinase/Rac1/p21-activated kinase signaling and reduced responsiveness to Stem Cell Factor stimulation. Consequently, treatment with a focal adhesion kinase inhibitor increased Shb knockout LT-HSC proliferation. The altered signaling characteristics thus provide a plausible mechanistic explanation for the changes in LT-HSC proliferation since these signaling intermediates have all been shown to participate in LT-HSC cell cycle control. In summary, the loss of Shb dependent signaling in bone marrow cells, resulting in elevated focal adhesion kinase activity and reduced proliferative responses in LT-HSCs under steady state hematopoiesis, confers a disadvantage to the maintenance of LT-HSCs over time. -- Highlights: • Shb is an adaptor protein operating downstream of tyrosine kinase receptors. • Shb deficiency reduces hematopoietic stem cell proliferation. • The proliferative effect of Shb occurs via

  4. The Src homology 2 protein Shb promotes cell cycle progression in murine hematopoietic stem cells by regulation of focal adhesion kinase activity

    International Nuclear Information System (INIS)

    Gustafsson, Karin; Heffner, Garrett; Wenzel, Pamela L.; Curran, Matthew; Grawé, Jan; McKinney-Freeman, Shannon L.; Daley, George Q.; Welsh, Michael

    2013-01-01

    The widely expressed adaptor protein Shb has previously been reported to contribute to T cell function due to its association with the T cell receptor and furthermore, several of Shb's known interaction partners are established regulators of blood cell development and function. In addition, Shb deficient embryonic stem cells displayed reduced blood cell colony formation upon differentiation in vitro. The aim of the current study was therefore to explore hematopoietic stem and progenitor cell function in the Shb knockout mouse. Shb deficient bone marrow contained reduced relative numbers of long-term hematopoietic stem cells (LT-HSCs) that exhibited lower proliferation rates. Despite this, Shb knockout LT-HSCs responded promptly by entering the cell cycle in response to genotoxic stress by 5-fluorouracil treatment. In competitive LT-HSC transplantations, Shb null cells initially engrafted as well as the wild-type cells but provided less myeloid expansion over time. Moreover, Shb knockout bone marrow cells exhibited elevated basal activities of focal adhesion kinase/Rac1/p21-activated kinase signaling and reduced responsiveness to Stem Cell Factor stimulation. Consequently, treatment with a focal adhesion kinase inhibitor increased Shb knockout LT-HSC proliferation. The altered signaling characteristics thus provide a plausible mechanistic explanation for the changes in LT-HSC proliferation since these signaling intermediates have all been shown to participate in LT-HSC cell cycle control. In summary, the loss of Shb dependent signaling in bone marrow cells, resulting in elevated focal adhesion kinase activity and reduced proliferative responses in LT-HSCs under steady state hematopoiesis, confers a disadvantage to the maintenance of LT-HSCs over time. -- Highlights: • Shb is an adaptor protein operating downstream of tyrosine kinase receptors. • Shb deficiency reduces hematopoietic stem cell proliferation. • The proliferative effect of Shb occurs via increased

  5. RNAi mediated acute depletion of Retinoblastoma protein (pRb promotes aneuploidy in human primary cells via micronuclei formation

    Directory of Open Access Journals (Sweden)

    Iovino Flora

    2009-11-01

    Full Text Available Abstract Background Changes in chromosome number or structure as well as supernumerary centrosomes and multipolar mitoses are commonly observed in human tumors. Thus, centrosome amplification and mitotic checkpoint dysfunctions are believed possible causes of chromosomal instability. The Retinoblastoma tumor suppressor (RB participates in the regulation of synchrony between DNA synthesis and centrosome duplication and it is involved in transcription regulation of some mitotic genes. Primary human fibroblasts were transfected transiently with short interfering RNA (siRNA specific for human pRb to investigate the effects of pRb acute loss on chromosomal stability. Results Acutely pRb-depleted fibroblasts showed altered expression of genes necessary for cell cycle progression, centrosome homeostasis, kinetochore and mitotic checkpoint proteins. Despite altered expression of genes involved in the Spindle Assembly Checkpoint (SAC the checkpoint seemed to function properly in pRb-depleted fibroblasts. In particular AURORA-A and PLK1 overexpression suggested that these two genes might have a role in the observed genomic instability. However, when they were post-transcriptionally silenced in pRb-depleted fibroblasts we did not observe reduction in the number of aneuploid cells. This finding suggests that overexpression of these two genes did not contribute to genomic instability triggered by RB acute loss although it affected cell proliferation. Acutely pRb-depleted human fibroblasts showed the presence of micronuclei containing whole chromosomes besides the presence of supernumerary centrosomes and aneuploidy. Conclusion Here we show for the first time that RB acute loss triggers centrosome amplification and aneuploidy in human primary fibroblasts. Altogether, our results suggest that pRb-depleted primary human fibroblasts possess an intact spindle checkpoint and that micronuclei, likely caused by mis-attached kinetochores that in turn trigger

  6. Protein Hydrolysates as Promoters of Non-Haem Iron Absorption

    Science.gov (United States)

    Li, Yanan; Jiang, Han; Huang, Guangrong

    2017-01-01

    Iron (Fe) is an essential micronutrient for human growth and health. Organic iron is an excellent iron supplement due to its bioavailability. Both amino acids and peptides improve iron bioavailability and absorption and are therefore valuable components of iron supplements. This review focuses on protein hydrolysates as potential promoters of iron absorption. The ability of protein hydrolysates to chelate iron is thought to be a key attribute for the promotion of iron absorption. Iron-chelatable protein hydrolysates are categorized by their absorption forms: amino acids, di- and tri-peptides and polypeptides. Their structural characteristics, including their size and amino acid sequence, as well as the presence of special amino acids, influence their iron chelation abilities and bioavailabilities. Protein hydrolysates promote iron absorption by keeping iron soluble, reducing ferric iron to ferrous iron, and promoting transport across cell membranes into the gut. We also discuss the use and relative merits of protein hydrolysates as iron supplements. PMID:28617327

  7. Protein Hydrolysates as Promoters of Non-Haem Iron Absorption

    Directory of Open Access Journals (Sweden)

    Yanan Li

    2017-06-01

    Full Text Available Iron (Fe is an essential micronutrient for human growth and health. Organic iron is an excellent iron supplement due to its bioavailability. Both amino acids and peptides improve iron bioavailability and absorption and are therefore valuable components of iron supplements. This review focuses on protein hydrolysates as potential promoters of iron absorption. The ability of protein hydrolysates to chelate iron is thought to be a key attribute for the promotion of iron absorption. Iron-chelatable protein hydrolysates are categorized by their absorption forms: amino acids, di- and tri-peptides and polypeptides. Their structural characteristics, including their size and amino acid sequence, as well as the presence of special amino acids, influence their iron chelation abilities and bioavailabilities. Protein hydrolysates promote iron absorption by keeping iron soluble, reducing ferric iron to ferrous iron, and promoting transport across cell membranes into the gut. We also discuss the use and relative merits of protein hydrolysates as iron supplements.

  8. Breast regression protein-39 (BRP-39) promotes dendritic cell maturation in vitro and enhances Th2 inflammation in murine model of asthma.

    Science.gov (United States)

    Xu, Qian; Chai, Shou-jie; Qian, Ying-ying; Zhang, Min; Wang, Kai

    2012-12-01

    To determine the roles of breast regression protein-39 (BRP-39) in regulating dendritic cell maturation and in pathology of acute asthma. Mouse bone marrow-derived dendritic cells (BMDCs) were prepared, and infected with adenovirus over-expressing BRP-39. Ovalbumin (OVA)-induced murine model of acute asthma was made in female BALB/c mice by sensitizing and challenging with chicken OVA and Imject Alum. The transfected BMDCs were adoptively transferred into OVA-treated mice via intravenous injection. Airway hyperresponsiveness (AHR), inflammation and pulmonary histopathology were characterized. The expression of BRP-39 mRNA and protein was significantly increased in lung tissues of OVA-treated mice. The BMDCs infected with adenovirus BRP-39 exhibited greater maturation and higher activity in vitro. Adoptive transfer of the cells into OVA-treated mice significantly augmented OVA-induced AHR and eosinophilic inflammation. Meanwhile, BRP-39 further enhanced the production of OVA-induced Th2 cytokines IL-4, IL-5 and IL-13, but significantly attenuated OVA-induced IFN-γ production in bronchoalveolar lavage fluid. In OVA-induced murine model of acute asthma, BRP-39 is over-expressed in lung tissue and augments Th2 inflammatory response and AHR. BRP-39 promotes dendritic cell maturation in vitro. Therefore, BRP-39 may be a potential therapeutic target of asthma.

  9. The C. elegans SoxC protein SEM-2 opposes differentiation factors to promote a proliferative blast cell fate in the postembryonic mesoderm

    Science.gov (United States)

    Tian, Chenxi; Shi, Herong; Colledge, Clark; Stern, Michael; Waterston, Robert; Liu, Jun

    2011-01-01

    The proper development of multicellular organisms requires precise regulation and coordination of cell fate specification, cell proliferation and differentiation. Abnormal regulation and coordination of these processes could lead to disease, including cancer. We have examined the function of the sole C. elegans SoxC protein, SEM-2, in the M lineage, which produces the postembryonic mesoderm. We found that SEM-2/SoxC is both necessary and sufficient to promote a proliferating blast cell fate, the sex myoblast fate, over a differentiated striated bodywall muscle fate. A number of factors control the specific expression of sem-2 in the sex myoblast precursors and their descendants. This includes direct control of sem-2 expression by a Hox-PBC complex. The crucial nature of the HOX/PBC factors in directly enhancing expression of this proliferative factor in the C. elegans M lineage suggests a possible more general link between Hox-PBC factors and SoxC proteins in regulating cell proliferation. PMID:21307099

  10. Panax ginseng total protein promotes proliferation and secretion of collagen in NIH/3T3 cells by activating extracellular signal-related kinase pathway

    Directory of Open Access Journals (Sweden)

    Xuenan Chen

    2017-07-01

    Conclusion: Our studies suggest that GTP promoted proliferation and secretion of collagen in NIH/3T3 cells by activating the ERK signal pathway, which shed light on a potential function of GTP in promoting wound healing.

  11. Bcl-w, a Radio-resistant Protein, Promotes the Gastric Cancer Cell Migration by inducing the phosphorylation of Focal Adhesion Kinase

    International Nuclear Information System (INIS)

    Bae, In Hwa; Yoon, Sung Hwan; Um, Hong Duck

    2008-01-01

    Gastric cancer is one of the leading malignancies in many countries and lethal for the high incidence of recurrence even after drastic surgical resection. Because local invasion and subsequent metastasis contributes to the failure of anticancer treatments of gastric cancer, a better understanding of the mechanisms involved in tumor invasiveness within the stomach seems to be essential for the control of this disease. Bcl-w is a prosurvival member of the Bcl-2 protein family, and thus protects cells from γ-irradiation. Recent reports suggest that Bcl-w can be upregulated in gastric cancer cells in a manner associated with the infiltrative (diffuse) types of the tumor. An analysis of Bcl-w function consistently revealed that Bcl-w can also promote the migratory and invasive potentials of gastric cancer cells. While it was shown that Bcl-w increases the invasiveness of cancer cells by sequentially inducing PI3K, Akt, SP1, and MMP-2, cellular components involved in Bcl-w-induced cell migration remain to be determined. This was the reason why we undertook the present study, which shows that FAK is a critical mediator of the cell migration induced by Bcl-w

  12. Disulfide scrambling in superoxide dismutase 1 reduces its cytotoxic effect in cultured cells and promotes protein aggregation.

    Directory of Open Access Journals (Sweden)

    Lina Leinartaitė

    Full Text Available Mutations in the gene coding for superoxide dismutase 1 (SOD1 are associated with familiar forms of the neurodegenerative disease amyotrophic lateral sclerosis (ALS. These mutations are believed to result in a "gain of toxic function", leading to neuronal degeneration. The exact mechanism is still unknown, but misfolding/aggregation events are generally acknowledged as important pathological events in this process. Recently, we observed that demetallated apoSOD1, with cysteine 6 and 111 substituted for alanine, is toxic to cultured neuroblastoma cells. This toxicity depended on an intact, high affinity Zn(2+ site. It was therefor contradictory to discover that wild-type apoSOD1 was not toxic, despite of its high affinity for Zn(2+. This inconsistency was hypothesized to originate from erroneous disulfide formation involving C6 and C111. Using high resolution non-reducing SDS-PAGE, we have in this study demonstrated that the inability of wild-type apoSOD1 to cause cell death stems from formation of non-native intra-molecular disulfides. Moreover, monomeric apoSOD1 variants capable of such disulfide scrambling aggregated into ThT positive oligomers under physiological conditions without agitation. The oligomers were stabilized by inter-molecular disulfides and morphologically resembled what has in other neurodegenerative diseases been termed protofibrils. Disulfide scrambling thus appears to be an important event for misfolding and aggregation of SOD1, but may also be significant for protein function involving cysteines, e.g. mitochondrial import and copper loading.

  13. CHIR99021 promotes self-renewal of mouse embryonic stem cells by modulation of protein-encoding gene and long intergenic non-coding RNA expression

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yongyan [College of Veterinary Medicine, Northwest A and F University, Yangling 712100, Shaanxi (China); Key Laboratory of Animal Biotechnology, Ministry of Agriculture, Northwest A and F University, Yangling 712100, Shaanxi (China); Ai, Zhiying [Key Laboratory of Animal Biotechnology, Ministry of Agriculture, Northwest A and F University, Yangling 712100, Shaanxi (China); College of Life Sciences, Northwest A and F University, Yangling 712100, Shaanxi (China); Yao, Kezhen [College of Veterinary Medicine, Northwest A and F University, Yangling 712100, Shaanxi (China); Key Laboratory of Animal Biotechnology, Ministry of Agriculture, Northwest A and F University, Yangling 712100, Shaanxi (China); Cao, Lixia; Du, Juan; Shi, Xiaoyan [Key Laboratory of Animal Biotechnology, Ministry of Agriculture, Northwest A and F University, Yangling 712100, Shaanxi (China); College of Life Sciences, Northwest A and F University, Yangling 712100, Shaanxi (China); Guo, Zekun, E-mail: gzk@nwsuaf.edu.cn [College of Veterinary Medicine, Northwest A and F University, Yangling 712100, Shaanxi (China); Key Laboratory of Animal Biotechnology, Ministry of Agriculture, Northwest A and F University, Yangling 712100, Shaanxi (China); Zhang, Yong, E-mail: zhylab@hotmail.com [College of Veterinary Medicine, Northwest A and F University, Yangling 712100, Shaanxi (China); Key Laboratory of Animal Biotechnology, Ministry of Agriculture, Northwest A and F University, Yangling 712100, Shaanxi (China)

    2013-10-15

    Embryonic stem cells (ESCs) can proliferate indefinitely in vitro and differentiate into cells of all three germ layers. These unique properties make them exceptionally valuable for drug discovery and regenerative medicine. However, the practical application of ESCs is limited because it is difficult to derive and culture ESCs. It has been demonstrated that CHIR99021 (CHIR) promotes self-renewal and enhances the derivation efficiency of mouse (m)ESCs. However, the downstream targets of CHIR are not fully understood. In this study, we identified CHIR-regulated genes in mESCs using microarray analysis. Our microarray data demonstrated that CHIR not only influenced the Wnt/β-catenin pathway by stabilizing β-catenin, but also modulated several other pluripotency-related signaling pathways such as TGF-β, Notch and MAPK signaling pathways. More detailed analysis demonstrated that CHIR inhibited Nodal signaling, while activating bone morphogenetic protein signaling in mESCs. In addition, we found that pluripotency-maintaining transcription factors were up-regulated by CHIR, while several developmental-related genes were down-regulated. Furthermore, we found that CHIR altered the expression of epigenetic regulatory genes and long intergenic non-coding RNAs. Quantitative real-time PCR results were consistent with microarray data, suggesting that CHIR alters the expression pattern of protein-encoding genes (especially transcription factors), epigenetic regulatory genes and non-coding RNAs to establish a relatively stable pluripotency-maintaining network. - Highlights: • Combined use of CHIR with LIF promotes self-renewal of J1 mESCs. • CHIR-regulated genes are involved in multiple pathways. • CHIR inhibits Nodal signaling and promotes Bmp4 expression to activate BMP signaling. • Expression of epigenetic regulatory genes and lincRNAs is altered by CHIR.

  14. CHIR99021 promotes self-renewal of mouse embryonic stem cells by modulation of protein-encoding gene and long intergenic non-coding RNA expression

    International Nuclear Information System (INIS)

    Wu, Yongyan; Ai, Zhiying; Yao, Kezhen; Cao, Lixia; Du, Juan; Shi, Xiaoyan; Guo, Zekun; Zhang, Yong

    2013-01-01

    Embryonic stem cells (ESCs) can proliferate indefinitely in vitro and differentiate into cells of all three germ layers. These unique properties make them exceptionally valuable for drug discovery and regenerative medicine. However, the practical application of ESCs is limited because it is difficult to derive and culture ESCs. It has been demonstrated that CHIR99021 (CHIR) promotes self-renewal and enhances the derivation efficiency of mouse (m)ESCs. However, the downstream targets of CHIR are not fully understood. In this study, we identified CHIR-regulated genes in mESCs using microarray analysis. Our microarray data demonstrated that CHIR not only influenced the Wnt/β-catenin pathway by stabilizing β-catenin, but also modulated several other pluripotency-related signaling pathways such as TGF-β, Notch and MAPK signaling pathways. More detailed analysis demonstrated that CHIR inhibited Nodal signaling, while activating bone morphogenetic protein signaling in mESCs. In addition, we found that pluripotency-maintaining transcription factors were up-regulated by CHIR, while several developmental-related genes were down-regulated. Furthermore, we found that CHIR altered the expression of epigenetic regulatory genes and long intergenic non-coding RNAs. Quantitative real-time PCR results were consistent with microarray data, suggesting that CHIR alters the expression pattern of protein-encoding genes (especially transcription factors), epigenetic regulatory genes and non-coding RNAs to establish a relatively stable pluripotency-maintaining network. - Highlights: • Combined use of CHIR with LIF promotes self-renewal of J1 mESCs. • CHIR-regulated genes are involved in multiple pathways. • CHIR inhibits Nodal signaling and promotes Bmp4 expression to activate BMP signaling. • Expression of epigenetic regulatory genes and lincRNAs is altered by CHIR

  15. Hepatic acute-phase proteins control innate immune responses during infection by promoting myeloid-derived suppressor cell function

    NARCIS (Netherlands)

    Sander, L.E.; Sackett, S.D.; Dierssen, U.; Beraza, N.; Linke, R.; Müller, M.R.; Blander, J.M.; Tacke, F.; Trautwein, C.

    2010-01-01

    Acute-phase proteins (APPs) are an evolutionarily conserved family of proteins produced mainly in the liver in response to infection and inflammation. Despite vast pro- and antiinflammatory properties ascribed to individual APPs, their collective function during infections remains poorly defined.

  16. Hepatic acute phase proteins control innate immune responses during infection by promoting myeloid derived suppressor cell function

    NARCIS (Netherlands)

    Sander, Leif E.; Dutton Sackett, Sara; Dierssen, Uta; Beraza, Naiara; Linke, Reinhold P.; Muller, Michael; Magarian Blander, Julie; Tacke, Frank; Trautwein, Christian

    2010-01-01

    Acute phase proteins (APPs) are an evolutionarily conserved family of proteins produced mainly in the liver in response to infection and inflammation. Despite vast pro- and anti-inflammatory properties ascribed to individual APPs, their collective function during infections remains poorly defined.

  17. Tumor necrosis factor alpha promotes the expression of immunosuppressive proteins and enhances the cell growth in a human bone marrow-derived stem cell culture

    International Nuclear Information System (INIS)

    Miettinen, Johanna A.; Pietilae, Mika; Salonen, Riikka J.; Ohlmeier, Steffen; Ylitalo, Kari; Huikuri, Heikki V.; Lehenkari, Petri

    2011-01-01

    Mesenchymal stem cells (MSCs) are widely used in experimental treatments for various conditions that involve normal tissue regeneration via inflammatory repair. It is known that MSCs can secrete multiple soluble factors and suppress inflammation. Even though the effect of MSCs on inflammation has been extensively studied, the effect of inflammation on MSCs is poorly understood. One of the major cytokines released at the site of inflammation is tumor necrosis factor alpha (TNF-α) which is known to induce MSC invasion and proliferation. Therefore, we wanted to test the effects of TNF-α exposure on MSCs derived from human bone marrow. We found, as expected, that cell proliferation was significantly enhanced during TNF-α exposure. However, according to the cell surface marker analysis, the intensity of several antigens in the minimum criteria panel for MSCs proposed by International Society of Cellular Therapy (ISCT) was decreased dramatically, and in certain cases, the criteria for MSCs were not fulfilled. In addition, TNF-α exposure resulted in a significant but transient increase in human leukocyte antigen and CD54 expression. Additional proteomic analysis by two-dimensional difference gel electrophoresis and mass spectrometry revealed three proteins whose expression levels decreased and 8 proteins whose expression levels increased significantly during TNF-α exposure. The majority of these proteins could be linked to immunosuppressive and signalling pathways. These results strongly support reactive and immunosuppressive activation of MSCs during TNF-α exposure, which might influence MSC differentiation stage and capacity.

  18. Tumor necrosis factor alpha promotes the expression of immunosuppressive proteins and enhances the cell growth in a human bone marrow-derived stem cell culture

    Energy Technology Data Exchange (ETDEWEB)

    Miettinen, Johanna A., E-mail: johanna.miettinen@oulu.fi [Institute of Clinical Medicine, Department of Internal Medicine, University of Oulu, P.O. Box 5000, FIN-90014 Oulu (Finland); Pietilae, Mika [Institute of Biomedicine, Department of Anatomy and Cell Biology, University of Oulu, P.O. Box 5000, FIN-90014 Oulu (Finland); Salonen, Riikka J. [Institute of Clinical Medicine, Department of Internal Medicine, University of Oulu, P.O. Box 5000, FIN-90014 Oulu (Finland); Institute of Biomedicine, Department of Anatomy and Cell Biology, University of Oulu, P.O. Box 5000, FIN-90014 Oulu (Finland); Ohlmeier, Steffen [Proteomics Core Facility, Biocenter Oulu, Department of Biochemistry, University of Oulu, P.O. Box 3000, FIN-90014 Oulu (Finland); Ylitalo, Kari; Huikuri, Heikki V. [Institute of Clinical Medicine, Department of Internal Medicine, University of Oulu, P.O. Box 5000, FIN-90014 Oulu (Finland); Lehenkari, Petri [Institute of Biomedicine, Department of Anatomy and Cell Biology, University of Oulu, P.O. Box 5000, FIN-90014 Oulu (Finland)

    2011-04-01

    Mesenchymal stem cells (MSCs) are widely used in experimental treatments for various conditions that involve normal tissue regeneration via inflammatory repair. It is known that MSCs can secrete multiple soluble factors and suppress inflammation. Even though the effect of MSCs on inflammation has been extensively studied, the effect of inflammation on MSCs is poorly understood. One of the major cytokines released at the site of inflammation is tumor necrosis factor alpha (TNF-{alpha}) which is known to induce MSC invasion and proliferation. Therefore, we wanted to test the effects of TNF-{alpha} exposure on MSCs derived from human bone marrow. We found, as expected, that cell proliferation was significantly enhanced during TNF-{alpha} exposure. However, according to the cell surface marker analysis, the intensity of several antigens in the minimum criteria panel for MSCs proposed by International Society of Cellular Therapy (ISCT) was decreased dramatically, and in certain cases, the criteria for MSCs were not fulfilled. In addition, TNF-{alpha} exposure resulted in a significant but transient increase in human leukocyte antigen and CD54 expression. Additional proteomic analysis by two-dimensional difference gel electrophoresis and mass spectrometry revealed three proteins whose expression levels decreased and 8 proteins whose expression levels increased significantly during TNF-{alpha} exposure. The majority of these proteins could be linked to immunosuppressive and signalling pathways. These results strongly support reactive and immunosuppressive activation of MSCs during TNF-{alpha} exposure, which might influence MSC differentiation stage and capacity.

  19. Angiopoietin-like protein 3 promotes preservation of stemness during Ex Vivo expansion of murine hematopoietic stem cells

    NARCIS (Netherlands)

    E. Farahbakhshian (Elnaz); M.M.A. Verstegen (Monique); T.P. Visser (Trudi); S. Kheradmandkia (Sima); D. Geerts (Dirk); S. Arshad (Shazia); N. Riaz (Noveen); F.G. Grosveld (Frank); N.P. van Til (Niek); J.P.P. Meijerink (Jules)

    2014-01-01

    textabstractAllogeneic hematopoietic stem cell (HSC) transplantations from umbilical cord blood or autologous HSCs for gene therapy purposes are hampered by limited number of stem cells. To test the ability to expand HSCs in vitro prior to transplantation, two growth factor cocktails containing stem

  20. The hypoxia-inducible factor-responsive proteins semaphorin 4D and vascular endothelial growth factor promote tumor growth and angiogenesis in oral squamous cell carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Hua; Yang, Ying-Hua [Department of Oncology and Diagnostic Sciences, University of Maryland Dental School, 650W. Baltimore Street, 7-North, Baltimore, MD 21201 (United States); Binmadi, Nada O. [Department of Oncology and Diagnostic Sciences, University of Maryland Dental School, 650W. Baltimore Street, 7-North, Baltimore, MD 21201 (United States); Department of Oral Basic and Clinical Sciences, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Proia, Patrizia [Department of Oncology and Diagnostic Sciences, University of Maryland Dental School, 650W. Baltimore Street, 7-North, Baltimore, MD 21201 (United States); Department of Sports Science (DISMOT), University of Palermo, Via Eleonora Duse 2 90146, Palermo (Italy); Basile, John R., E-mail: jbasile@umaryland.edu [Department of Oncology and Diagnostic Sciences, University of Maryland Dental School, 650W. Baltimore Street, 7-North, Baltimore, MD 21201 (United States); Greenebaum Cancer Center, 22S. Greene Street, Baltimore, MD 21201 (United States)

    2012-08-15

    Growth and metastasis of solid tumors requires induction of angiogenesis to ensure the delivery of oxygen, nutrients and growth factors to rapidly dividing transformed cells. Through either mutations, hypoxia generated by cytoreductive therapies, or when a malignancy outgrows its blood supply, tumor cells undergo a change from an avascular to a neovascular phenotype, a transition mediated by the hypoxia-inducible factor (HIF) family of transcriptional regulators. Vascular endothelial growth factor (VEGF) is one example of a gene whose transcription is stimulated by HIF. VEGF plays a crucial role in promoting tumor growth and survival by stimulating new blood vessel growth in response to such stresses as chemotherapy or radiotherapy-induced hypoxia, and it therefore has become a tempting target for neutralizing antibodies in the treatment of advanced neoplasms. Emerging evidence has shown that the semaphorins, proteins originally associated with control of axonal growth and immunity, are regulated by changes in oxygen tension as well and may play a role in tumor-induced angiogenesis. Through the use of RNA interference, in vitro and in vivo angiogenesis assays and tumor xenograft experiments, we demonstrate that expression of semaphorin 4D (SEMA4D), which is under the control of the HIF-family of transcription factors, cooperates with VEGF to promote tumor growth and vascularity in oral squamous cell carcinoma (OSCC). We use blocking antibodies to show that targeting SEMA4D function along with VEGF could represent a novel anti-angiogenic therapeutic strategy for the treatment of OSCC and other solid tumors. -- Highlights: Black-Right-Pointing-Pointer Similar to VEGF, SEMA4D promotes angiogenesis in vitro and in vivo. Black-Right-Pointing-Pointer Both VEGF and SEMA4D are produced by OSCC cells in a HIF-dependent manner. Black-Right-Pointing-Pointer These factors combine to elicit a robust pro-angiogenic phenotype in OSCC. Black-Right-Pointing-Pointer Anti-SEMA4D

  1. The hypoxia-inducible factor-responsive proteins semaphorin 4D and vascular endothelial growth factor promote tumor growth and angiogenesis in oral squamous cell carcinoma

    International Nuclear Information System (INIS)

    Zhou, Hua; Yang, Ying-Hua; Binmadi, Nada O.; Proia, Patrizia; Basile, John R.

    2012-01-01

    Growth and metastasis of solid tumors requires induction of angiogenesis to ensure the delivery of oxygen, nutrients and growth factors to rapidly dividing transformed cells. Through either mutations, hypoxia generated by cytoreductive therapies, or when a malignancy outgrows its blood supply, tumor cells undergo a change from an avascular to a neovascular phenotype, a transition mediated by the hypoxia-inducible factor (HIF) family of transcriptional regulators. Vascular endothelial growth factor (VEGF) is one example of a gene whose transcription is stimulated by HIF. VEGF plays a crucial role in promoting tumor growth and survival by stimulating new blood vessel growth in response to such stresses as chemotherapy or radiotherapy-induced hypoxia, and it therefore has become a tempting target for neutralizing antibodies in the treatment of advanced neoplasms. Emerging evidence has shown that the semaphorins, proteins originally associated with control of axonal growth and immunity, are regulated by changes in oxygen tension as well and may play a role in tumor-induced angiogenesis. Through the use of RNA interference, in vitro and in vivo angiogenesis assays and tumor xenograft experiments, we demonstrate that expression of semaphorin 4D (SEMA4D), which is under the control of the HIF-family of transcription factors, cooperates with VEGF to promote tumor growth and vascularity in oral squamous cell carcinoma (OSCC). We use blocking antibodies to show that targeting SEMA4D function along with VEGF could represent a novel anti-angiogenic therapeutic strategy for the treatment of OSCC and other solid tumors. -- Highlights: ► Similar to VEGF, SEMA4D promotes angiogenesis in vitro and in vivo. ► Both VEGF and SEMA4D are produced by OSCC cells in a HIF-dependent manner. ► These factors combine to elicit a robust pro-angiogenic phenotype in OSCC. ► Anti-SEMA4D blocking antibody inhibits Plexin-B1 activation. ► SEMA4D is a valid anti-angiogenic target in the

  2. S100-A9 protein in exosomes from chronic lymphocytic leukemia cells promotes NF-κB activity during disease progression.

    Science.gov (United States)

    Prieto, Daniel; Sotelo, Natalia; Seija, Noé; Sernbo, Sandra; Abreu, Cecilia; Durán, Rosario; Gil, Magdalena; Sicco, Estefanía; Irigoin, Victoria; Oliver, Carolina; Landoni, Ana Inés; Gabus, Raúl; Dighiero, Guillermo; Oppezzo, Pablo

    2017-08-10

    Chronic lymphocytic leukemia (CLL) is an incurable disease characterized by accumulation of clonal B lymphocytes, resulting from a complex balance between cell proliferation and apoptotic death. Continuous crosstalk between cancer cells and local/distant host environment is required for effective tumor growth. Among the main actors of this dynamic interplay between tumoral cells and their microenvironment are the nano-sized vesicles called exosomes. Emerging evidence indicates that secretion, composition, and functional capacity of exosomes are altered as tumors progress to an aggressive phenotype. In CLL, no data exist exploring the specific changes in the proteomic profile of plasma-derived exosomes from patients during disease evolution. We hereby report for the first time different proteomic profiles of plasma exosomes, both between indolent and progressive CLLs as well as within the individual patients at the onset of disease and during its progression. Next, we focus on the changes of the exosome protein cargoes, which are found exclusively in patients with progressive CLL after disease progression. The alterations in the proteomic cargoes underline different networks specific for leukemia progression related to inflammation, oxidative stress, and NF-κB and phosphatidylinositol 3-kinase/AKT pathway activation. Finally, our results suggest a preponderant role for the protein S100-A9 as an activator of the NFκB pathway during CLL progression and suggest that the leukemic clone can generate an autoactivation loop through S100-A9 expression, NF-κB activation, and exosome secretion. Collectively, our data propose a new pathway for NF-κB activation in CLL and highlight the importance of exosomes as extracellular mediators promoting tumor progression in CLL. © 2017 by The American Society of Hematology.

  3. Tumor cell surface proteins

    International Nuclear Information System (INIS)

    Kennel, S.J.; Braslawsky, G.R.; Flynn, K.; Foote, L.J.; Friedman, E.; Hotchkiss, J.A.; Huang, A.H.L.; Lankford, P.K.

    1982-01-01

    Cell surface proteins mediate interaction between cells and their environment. Unique tumor cell surface proteins are being identified and quantified in several tumor systems to address the following questions: (i) how do tumor-specific proteins arise during cell transformation; (ii) can these proteins be used as markers of tumor cell distribution in vivo; (iii) can cytotoxic drugs be targeted specifically to tumor cells using antibody; and (iv) can solid state radioimmunoassay of these proteins provide a means to quantify transformation frequencies. A tumor surface protein of 180,000 M/sub r/ (TSP-180) has been identified on cells of several lung carcinomas of BALB/c mice. TSP-180 was not detected on normal lung tissue, embryonic tissue, or other epithelial or sarcoma tumors, but it was found on lung carcinomas of other strains of mice. Considerable amino acid sequence homology exists among TSP-180's from several cell sources, indicating that TSP-180 synthesis is directed by normal cellular genes although it is not expressed in normal cells. The regulation of synthesis of TSP-180 and its relationship to normal cell surface proteins are being studied. Monoclonal antibodies (MoAb) to TSP-180 have been developed. The antibodies have been used in immunoaffinity chromatography to isolate TSP-180 from tumor cell sources. This purified tumor antigen was used to immunize rats. Antibody produced by these animals reacted at different sites (epitopes) on the TSP-180 molecule than did the original MoAb. These sera and MoAb from these animals are being used to identify normal cell components related to the TSP-180 molecule

  4. Recombinant human bone morphogenetic protein-2 released from polyurethane-based scaffolds promotes early osteogenic differentiation of human mesenchymal stem cells

    International Nuclear Information System (INIS)

    Kim, Jinku; Hollinger, Jeffrey O

    2012-01-01

    The purposes of this study were to determine the pharmacokinetics of recombinant human bone morphogenetic protein-2 (rhBMP-2) from a polyurethane (PUR)-based porous scaffold and to determine the biological responses of human mesenchymal stem cells (hMSCs) to the rhBMP-2 released from those scaffolds. The rhBMP-2 was incorporated into the PUR three-dimensional (3D) porous scaffolds and release profiles were determined using enzyme-linked immunosorbent assay. The bioactivity of the rhBMP-2 containing releasates was determined using hMSCs and compared with exogenous rhBMP-2. Release of rhBMP-2 from PUR-based systems was bi-phasic and characterized by an initial burst followed by a sustained release for up to 21 days. Expression of alkaline phosphatase activity by hMSCs treated with the rhBMP-2 releasates was significantly greater than the cells alone (control) throughout the time periods. Furthermore, after 14 days of culture, the hMSCs cultured with rhBMP-2 releasate had a greater amount of mineralization compared to exogenous rhBMP-2. Overall, the rhBMP-2 release from the PUR-based scaffolds was sustained for 21 days and the releasates appeared to be bioactive and promoted earlier osteogenic differentiation and mineralization of hMSCs than the exogenous rhBMP-2. (paper)

  5. MicroRNA-194 promotes the growth, migration, and invasion of ovarian carcinoma cells by targeting protein tyrosine phosphatase nonreceptor type 12

    Directory of Open Access Journals (Sweden)

    Liang T

    2016-07-01

    Full Text Available Tian Liang, Liru Li, Yan Cheng, Chengcheng Ren, Guangmei Zhang Department of Gynecology and Obstetrics, The first Affiliated Hospital of Harbin Medical University, Nangang District, Harbin, Hei Longjiang, People’s Republic of China Abstract: Ovarian carcinoma is the most lethal gynecologic malignancy among women. Ovarian cancer metastasis is the main reason for poor prognosis. MicroRNAs (miRNAs have been shown to play an important role in tumorigenesis and metastasis in various cancers by affecting the expression of their targets. In this study, we explored the role of miR-194 in ovarian cancer. Real-time polymerase chain reaction assays showed that miR-194 was significantly upregulated in ovarian cancer tissues. Overexpression of miR-194 in ovarian cancer cells promotes cell proliferation, migration, and invasion; in contrast, inhibition of the expression of miR-194 has the opposite effects. Meanwhile, bioinformatics tools were used to identify protein tyrosine phosphatase nonreceptor type 12 (PTPN12 as a potential target of miR-194. The luciferase assay showed that miR-194 directly binds to the 3'-untranslated region of PTPN12. Western blot analysis and quantitative real-time polymerase chain reaction assay revealed that PTPN12 expression was negatively associated with miR-194 expression in both ovarian cancer tissues and cells. Thus, we conclude that miR-194 targets PTPN12 and functions as an oncogene in ovarian cancer cells. This novel pathway may provide a new insight to explain ovarian cancer development and metastasis. Keywords: miR-194, ovarian cancer, PTPN12, metastasis

  6. Nrf1 CNC-bZIP protein promotes cell survival and nucleotide excision repair through maintaining glutathione homeostasis.

    Science.gov (United States)

    Han, Weinong; Ming, Mei; Zhao, Rui; Pi, Jingbo; Wu, Chunli; He, Yu-Ying

    2012-05-25

    Skin cancer is the most common cancer in the United States. Its major environmental risk factor is UVB radiation in sunlight. In response to UVB damage, epidermal keratinocytes activate a specific repair pathway, i.e. nucleotide excision repair, to remove UVB-induced DNA lesions. However, the regulation of UVB response is not fully understood. Here we show that the long isoform of the nuclear factor erythroid 2-related factor 1 (Nrf1, also called NFE2L1), a cytoprotective transcription factor critical for the expression of multiple antioxidant response element-dependent genes, plays an important role in the response of keratinocytes to UVB. Nrf1 loss sensitized keratinocytes to UVB-induced apoptosis by up-regulating the expression of the proapoptotic Bcl-2 family member Bik through reducing glutathione levels. Knocking down Bik reduced UVB-induced apoptosis in Nrf1-inhibited cells. In UVB-irradiated surviving cells, however, disruption of Nrf1 impaired nucleotide excision repair through suppressing the transcription of xeroderma pigmentosum C (XPC), a factor essential for initiating the global genome nucleotide excision repair by recognizing the DNA lesion and recruiting downstream factors. Nrf1 enhanced XPC expression by increasing glutathione availability but was independent of the transcription repressor of XPC. Adding XPC or glutathione restored the DNA repair capacity in Nrf1-inhibited cells. Finally, we demonstrate that Nrf1 levels are significantly reduced by UVB radiation in mouse skin and are lower in human skin tumors than in normal skin. These results indicate a novel role of Nrf1 in UVB-induced DNA damage repair and suggest Nrf1 as a tumor suppressor in the skin.

  7. The architecture of mammalian ribosomal protein promoters

    Directory of Open Access Journals (Sweden)

    Perry Robert P

    2005-02-01

    Full Text Available Abstract Background Mammalian ribosomes contain 79 different proteins encoded by widely scattered single copy genes. Coordinate expression of these genes at transcriptional and post-transcriptional levels is required to ensure a roughly equimolar accumulation of ribosomal proteins. To date, detailed studies of only a very few ribosomal protein (rp promoters have been made. To elucidate the general features of rp promoter architecture, I made a detailed sequence comparison of the promoter regions of the entire set of orthologous human and mouse rp genes. Results A striking evolutionarily conserved feature of most rp genes is the separation by an intron of the sequences involved in transcriptional and translational regulation from the sequences with protein encoding function. Another conserved feature is the polypyrimidine initiator, which conforms to the consensus (Y2C+1TY(T2(Y3. At least 60 % of the rp promoters contain a largely conserved TATA box or A/T-rich motif, which should theoretically have TBP-binding capability. A remarkably high proportion of the promoters contain conserved binding sites for transcription factors that were previously implicated in rp gene expression, namely upstream GABP and Sp1 sites and downstream YY1 sites. Over 80 % of human and mouse rp genes contain a transposable element residue within 900 bp of 5' flanking sequence; very little sequence identity between human and mouse orthologues was evident more than 200 bp upstream of the transcriptional start point. Conclusions This analysis has provided some valuable insights into the general architecture of mammalian rp promoters and has identified parameters that might coordinately regulate the transcriptional activity of certain subsets of rp genes.

  8. Human T-cell leukemia virus type 1 Tax requires direct access to DNA for recruitment of CREB binding protein to the viral promoter.

    Science.gov (United States)

    Lenzmeier, B A; Giebler, H A; Nyborg, J K

    1998-02-01

    Efficient human T-cell leukemia virus type 1 (HTLV-1) replication and viral gene expression are dependent upon the virally encoded oncoprotein Tax. To activate HTLV-1 transcription, Tax interacts with the cellular DNA binding protein cyclic AMP-responsive element binding protein (CREB) and recruits the coactivator CREB binding protein (CBP), forming a nucleoprotein complex on the three viral cyclic AMP-responsive elements (CREs) in the HTLV-1 promoter. Short stretches of dG-dC-rich (GC-rich) DNA, immediately flanking each of the viral CREs, are essential for Tax recruitment of CBP in vitro and Tax transactivation in vivo. Although the importance of the viral CRE-flanking sequences is well established, several studies have failed to identify an interaction between Tax and the DNA. The mechanistic role of the viral CRE-flanking sequences has therefore remained enigmatic. In this study, we used high resolution methidiumpropyl-EDTA iron(II) footprinting to show that Tax extended the CREB footprint into the GC-rich DNA flanking sequences of the viral CRE. The Tax-CREB footprint was enhanced but not extended by the KIX domain of CBP, suggesting that the coactivator increased the stability of the nucleoprotein complex. Conversely, the footprint pattern of CREB on a cellular CRE lacking GC-rich flanking sequences did not change in the presence of Tax or Tax plus KIX. The minor-groove DNA binding drug chromomycin A3 bound to the GC-rich flanking sequences and inhibited the association of Tax and the Tax-CBP complex without affecting CREB binding. Tax specifically cross-linked to the viral CRE in the 5'-flanking sequence, and this cross-link was blocked by chromomycin A3. Together, these data support a model where Tax interacts directly with both CREB and the minor-groove viral CRE-flanking sequences to form a high-affinity binding site for the recruitment of CBP to the HTLV-1 promoter.

  9. ADAM12/syndecan-4 signaling promotes beta 1 integrin-dependent cell spreading through protein kinase Calpha and RhoA

    DEFF Research Database (Denmark)

    Thodeti, Charles Kumar; Albrechtsen, Reidar; Grauslund, Morten

    2002-01-01

    The ADAMs (a disintegrin and metalloprotease) comprise a large family of multidomain proteins with cell-binding and metalloprotease activities. The ADAM12 cysteine-rich domain (rADAM12-cys) supports cell attachment using syndecan-4 as a primary cell surface receptor that subsequently triggers beta...

  10. 17beta-estradiol promotes the odonto/osteogenic differentiation of stem cells from apical papilla via mitogen-activated protein kinase pathway.

    Science.gov (United States)

    Li, Yao; Yan, Ming; Wang, Zilu; Zheng, Yangyu; Li, Junjun; Ma, Shu; Liu, Genxia; Yu, Jinhua

    2014-11-17

    Estrogen plays an important role in the osteogenic differentiation of mesenchymal stem cells, while stem cells from apical papilla (SCAP) can contribute to the formation of dentin/bone-like tissues. To date, the effects of estrogen on the differentiation of SCAP remain unclear. SCAP was isolated and treated with 10⁻⁷ M 17beta-estradiol (E2). The odonto/osteogenic potency and the involvement of mitogen-activated protein kinase (MAPK) signaling pathway were subsequently investigated by using methyl-thiazolyl-tetrazolium (MTT) assay, and other methods. MTT and flow cytometry results demonstrated that E2 treatment had no effect on the proliferation of SCAP in vitro, while alkaline phosphatase (ALP) assay and alizarin red staining showed that E2 can significantly promote ALP activity and mineralization ability in SCAP. Real-time reverse transcription polymerase chain reaction (RT-PCR) and western blot assay revealed that the odonto/osteogenic markers (ALP, DMP1/DMP1, DSPP/DSP, RUNX2/RUNX2, OSX/OSX and OCN/OCN) were significantly upregulated in E2-treated SCAP. In addition, the expression of phosphor-p38 and phosphor-JNK in these stem cells was enhanced by E2 treatment, as was the expression of the nuclear downstream transcription factors including phosphor-Sp1, phosphor-Elk-1, phosphor-c-Jun and phosphor-c-Fos, indicating the activation of MAPK signaling pathway during the odonto/osteogenic differentiation of E2-treated SCAP. Conversely, the differentiation of E2-treated SCAP was inhibited in the presence of MAPK specific inhibitors. The ondonto/osteogenic differentiation of SCAP is enhanced by 10⁻⁷ M 17beta-estradiol via the activation of MAPK signaling pathway.

  11. Characterization of the N-terminal segment used by the barley yellow dwarf virus movement protein to promote interaction with the nuclear membrane of host plant cells.

    Science.gov (United States)

    Dennison, Sarah Rachel; Harris, Frederick; Brandenburg, Klaus; Phoenix, David Andrew

    2007-11-01

    The barley yellow dwarf virus movement protein (BYDV-MP) requires its N-terminal sequence to promote the transport of viral RNA into the nuclear compartment of host plant cells. Here, graphical analysis predicts that this sequence would form a membrane interactive amphiphilic alpha-helix. Confirming this prediction, NT1, a peptide homologue of the BYDV-MP N-terminal sequence, was found to be alpha-helical (65%) in the presence of vesicles mimics of the nuclear membrane. The peptide increased the fluidity of these nuclear membrane mimics (rise in wavenumber of circa 0.5-1.0 cm(-1)) and induced surface pressure changes of 2 mN m(-1) in lipid monolayers with corresponding compositions. Taken with isotherm analysis these results suggest that BYDV-MP forms an N-terminal amphiphilic alpha-helix, which partitions into the nuclear membrane primarily through thermodynamically stable associations with the membrane lipid headgroup region. We speculate that these associations may play a role in targeting of the nuclear membrane by BYDM-MP.

  12. Downregulation of miR-200a-3p induced by hepatitis B Virus X (HBx) Protein promotes cell proliferation and invasion in HBV-infection-associated hepatocarcinoma.

    Science.gov (United States)

    Shi, Taiyang; Hua, Qinfang; Ma, Zhipeng; Lv, Qijun

    2017-12-01

    Hepatitis B Virus X (HBx) Protein encoded by HBV is believed to be the major player in the process of HBV-induced oncogenesis. Ectopic expression of miR-200a-3p was reported to be associated with diverse tumorigenesis. This study aimed to better understand the role of miR-200a-3p and its correlation with HBx in HBV-induced hepatocellular carcinoma (HCC). In this report, we examined the gene expression using quantitative RT-PCR and protein expression using Western blotting analysis. Cells were transfected with miR-200a-3p mimics or empty vector, and HBx-carrying vector or empty vector. Cell viability was tested using CCK-8 assay. Wound healing assay was performed to assess cell migration while Transwell assay was performed to evaluate cell invasion. miR-200a-3p was downregulated in HBV-positive tissue samples compared with HBV-negative tissue samples. This result was further confirmed with HBV-positive and - negative cell lines. HBx protein was overexpressed in HBV-positive cells where expression of miR-200a-3p was significantly suppressed. Increased cell viability, altered cell cycle progression, increased cell migration and invasion occurred in HBx-overexpressed cells compared to its controls. In forced expressed miR-200a-3p cells, cell viability, cell migration and invasion were significantly decreased, and cell cycle status was altered compared to its controls. Taken together, pathogenetic function of HBx is negatively correlated with miR-200a-3p in HBV-cased HCC through regulating cell viability, cell cycle arrest, cell migration and cell invasion. Copyright © 2017 Elsevier GmbH. All rights reserved.

  13. Characterization of a Lactococcus lactis promoter for heterologous protein production

    Directory of Open Access Journals (Sweden)

    Christian E. Ogaugwu

    2018-03-01

    Full Text Available Constitutively active promoter elements for heterologous protein production in Lactococcus lactis are scarce. Here, the promoter of the PTS-IIC gene cluster from L. lactis NZ3900 is described. This promoter was cloned upstream of an enhanced green fluorescent protein, GFPmut3a, and transformed into L. lactis. Transformants produced up to 13.5 μg of GFPmut3a per milliliter of log phase cells. Addition of cellobiose further increased the production of GFPmut3a by up to two-fold when compared to glucose. Analysis of mutations at two specific positions in the PTS-IIC promoter showed that a ‘T’ to ‘G’ mutation within the −35 element resulted in constitutive expression in glucose, while a ‘C’ at nucleotide 7 in the putative cre site enhanced promoter activity in cellobiose. Finally, this PTS-IIC promoter is capable of mediating protein expression in Bacillus subtilis and Escherichia coli Nissle 1917, suggesting the potential for future biotechnological applications of this element and its derivatives.

  14. [Sustained release of recombinant human bone morphogenetic protein-2 combined with stromal vascular fraction cells in promoting posterolateral spinal fusion in rat model].

    Science.gov (United States)

    Yuan, Wei; Zheng, Jun; Qian, Jinyu; Zhou, Xiaoxiao; Wang, Minghui; Wang, Xiuhui

    2017-07-01

    To observe the effect of stromal vascular fraction cells (SVFs) from rat fat tissue combined with sustained release of recombinant human bone morphogenetic protein-2 (rhBMP-2) in promoting the lumbar fusion in rat model. SVFs were harvested from subcutaneous fat of bilateral inguinal region of 4-month-old rat through the collagenase I digestion. The sustained release carrier was prepared via covalent bond of the rhBMP-2 and β-tricalcium phosphate (β-TCP) by the biominetic apatite coating process. The sustained release effect was measured by BCA method. Thirty-two rats were selected to establish the posterolateral lumbar fusion model and were divided into 4 groups, 8 rats each group. The decalcified bone matrix (DBX) scaffold+PBS, DBX scaffold+rhBMP-2/β-TCP sustained release carrier, DBX scaffold+SVFs, and DBX scaffold+rhBMP-2/β-TCP sustained release carrier+SVFs were implanted in groups A, B, C, and D respectively. X-ray films, manual spine palpation, and high-resolution micro-CT were used to evaluate spinal fusion at 8 weeks after operation; bone mineral density (BMD) and bone volume fraction were analyzed; the new bone formation was evaluated by HE staining and Masson's trichrome staining, osteocalcin (OCN) was detected by immunohistochemical staining. The cumulative release amount of rhBMP-2 was about 40% at 2 weeks, indicating sustained release effect of rhBMP-2; while the control group was almost released within 2 weeks. At 8 weeks, the combination of manual spine palpation, X-ray, and micro-CT evaluation showed that group D had the strongest bone formation (100%, 8/8), followed by group B (75%, 6/8), group C (37.5%, 3/8), and group A (12.5%, 1/8). Micro-CT analysis showed BMD and bone volume fraction were significantly higher in group D than groups A, B, and C ( P cells with bone matrix deposition, and an active osteogenic process similar to the mineralization of long bones in group D. The bone formation of group B was weaker than that of group D, and

  15. Mammalian amyloidogenic proteins promote prion nucleation in yeast.

    Science.gov (United States)

    Chandramowlishwaran, Pavithra; Sun, Meng; Casey, Kristin L; Romanyuk, Andrey V; Grizel, Anastasiya V; Sopova, Julia V; Rubel, Aleksandr A; Nussbaum-Krammer, Carmen; Vorberg, Ina M; Chernoff, Yury O

    2018-03-02

    Fibrous cross-β aggregates (amyloids) and their transmissible forms (prions) cause diseases in mammals (including humans) and control heritable traits in yeast. Initial nucleation of a yeast prion by transiently overproduced prion-forming protein or its (typically, QN-rich) prion domain is efficient only in the presence of another aggregated (in most cases, QN-rich) protein. Here, we demonstrate that a fusion of the prion domain of yeast protein Sup35 to some non-QN-rich mammalian proteins, associated with amyloid diseases, promotes nucleation of Sup35 prions in the absence of pre-existing aggregates. In contrast, both a fusion of the Sup35 prion domain to a multimeric non-amyloidogenic protein and the expression of a mammalian amyloidogenic protein that is not fused to the Sup35 prion domain failed to promote prion nucleation, further indicating that physical linkage of a mammalian amyloidogenic protein to the prion domain of a yeast protein is required for the nucleation of a yeast prion. Biochemical and cytological approaches confirmed the nucleation of protein aggregates in the yeast cell. Sequence alterations antagonizing or enhancing amyloidogenicity of human amyloid-β (associated with Alzheimer's disease) and mouse prion protein (associated with prion diseases), respectively, antagonized or enhanced nucleation of a yeast prion by these proteins. The yeast-based prion nucleation assay, developed in our work, can be employed for mutational dissection of amyloidogenic proteins. We anticipate that it will aid in the identification of chemicals that influence initial amyloid nucleation and in searching for new amyloidogenic proteins in a variety of proteomes. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

  16. Interaction of Prevotella intermedia strain 17 leucine-rich repeat domain protein AdpF with eukaryotic cells promotes bacterial internalization.

    Science.gov (United States)

    Sengupta, Dipanwita; Kang, Dae-Joong; Anaya-Bergman, Cecilia; Wyant, Tiana; Ghosh, Arnab K; Miyazaki, Hiroshi; Lewis, Janina P

    2014-06-01

    Prevotella intermedia is an oral bacterium implicated in a variety of oral diseases. Although internalization of this bacterium by nonphagocytic host cells is well established, the molecular players mediating the process are not well known. Here, the properties of a leucine-rich repeat (LRR) domain protein, designated AdpF, are described. This protein contains a leucine-rich region composed of 663 amino acid residues, and molecular modeling shows that it folds into a classical curved solenoid structure. The cell surface localization of recombinant AdpF (rAdpF) was confirmed by electron and confocal microscopy analyses. The recombinant form of this protein bound fibronectin in a dose-dependent manner. Furthermore, the protein was internalized by host cells, with the majority of the process accomplished within 30 min. The internalization of rAdpF was inhibited by nystatin, cytochalasin, latrunculin, nocodazole, and wortmannin, indicating that microtubules, microfilaments, and signal transduction are required for the invasion. It is noteworthy that preincubation of eukaryotic cells with AdpF increased P. intermedia 17 internalization by 5- and 10-fold for HeLa and NIH 3T3 fibroblast cell lines, respectively. The addition of the rAdpF protein was also very effective in inducing bacterial internalization into the oral epithelial cell line HN4, as well as into primary cells, including human oral keratinocytes (HOKs) and human umbilical vein endothelial cells (HUVECs). Finally, cells exposed to P. intermedia 17 internalized the bacteria more readily upon reinfection. Taken together, our data demonstrate that rAdpF plays a role in the internalization of P. intermedia 17 by a variety of host cells.

  17. PERK Signal-Modulated Protein Translation Promotes the Survivability of Dengue 2 Virus-Infected Mosquito Cells and Extends Viral Replication.

    Science.gov (United States)

    Hou, Jiun-Nan; Chen, Tien-Huang; Chiang, Yi-Hsuan; Peng, Jing-Yun; Yang, Tsong-Han; Cheng, Chih-Chieh; Sofiyatun, Eny; Chiu, Cheng-Hsun; Chiang-Ni, Chuan; Chen, Wei-June

    2017-09-20

    Survival of mosquitoes from dengue virus (DENV) infection is a prerequisite of viral transmission to the host. This study aimed to see how mosquito cells can survive the infection during prosperous replication of the virus. In C6/36 cells, global protein translation was shut down after infection by DENV type 2 (DENV2). However, it returned to a normal level when infected cells were treated with an inhibitor of the protein kinase RNA (PKR)-like ER kinase (PERK) signaling pathway. Based on a 7-Methylguanosine 5'-triphosphate (m7GTP) pull-down assay, the eukaryotic translation initiation factor 4F (eIF4F) complex was also identified in DENV2-infected cells. This suggests that most mosquito proteins are synthesized via canonical cap-dependent translation. When the PERK signal pathway was inhibited, both accumulation of reactive oxygen species and changes in the mitochondrial membrane potential increased. This suggested that ER stress response was alleviated through the PERK-mediated shutdown of global proteins in DENV2-infected C6/36 cells. In the meantime, the activities of caspases-9 and -3 and the apoptosis-related cell death rate increased in C6/36 cells with PERK inhibition. This reflected that the PERK-signaling pathway is involved in determining cell survival, presumably by reducing DENV2-induced ER stress. Looking at the PERK downstream target, α-subunit of eukaryotic initiation factor 2 (eIF2α), an increased phosphorylation status was only shown in infected C6/36 cells. This indicated that recruitment of ribosome binding to the mRNA 5'-cap structure could have been impaired in cap-dependent translation. It turned out that shutdown of cellular protein translation resulted in a pro-survival effect on mosquito cells in response to DENV2 infection. As synthesis of viral proteins was not affected by the PERK signal pathway, an alternate mode other than cap-dependent translation may be utilized. This finding provides insights into elucidating how the PERK signal

  18. Anaphase-promoting complex/cyclosome protein Cdc27 is a target for curcumin-induced cell cycle arrest and apoptosis

    Science.gov (United States)

    2012-01-01

    Background Curcumin (diferuloylmethane), the yellow pigment in the Asian spice turmeric, is a hydrophobic polyphenol from the rhizome of Curcuma longa. Because of its chemopreventive and chemotherapeutic potential with no discernable side effects, it has become one of the major natural agents being developed for cancer therapy. Accumulating evidence suggests that curcumin induces cell death through activation of apoptotic pathways and inhibition of cell growth and proliferation. The mitotic checkpoint, or spindle assembly checkpoint (SAC), is the major cell cycle control mechanism to delay the onset of anaphase during mitosis. One of the key regulators of the SAC is the anaphase promoting complex/cyclosome (APC/C) which ubiquitinates cyclin B and securin and targets them for proteolysis. Because APC/C not only ensures cell cycle arrest upon spindle disruption but also promotes cell death in response to prolonged mitotic arrest, it has become an attractive drug target in cancer therapy. Methods Cell cycle profiles were determined in control and curcumin-treated medulloblastoma and various other cancer cell lines. Pull-down assays were used to confirm curcumin binding. APC/C activity was determined using an in vitro APC activity assay. Results We identified Cdc27/APC3, a component of the APC/C, as a novel molecular target of curcumin and showed that curcumin binds to and crosslinks Cdc27 to affect APC/C function. We further provide evidence that curcumin preferably induces apoptosis in cells expressing phosphorylated Cdc27 usually found in highly proliferating cells. Conclusions We report that curcumin directly targets the SAC to induce apoptosis preferably in cells with high levels of phosphorylated Cdc27. Our studies provide a possible molecular mechanism why curcumin induces apoptosis preferentially in cancer cells and suggest that phosphorylation of Cdc27 could be used as a biomarker to predict the therapeutic response of cancer cells to curcumin. PMID:22280307

  19. Anaphase-promoting complex/cyclosome protein Cdc27 is a target for curcumin-induced cell cycle arrest and apoptosis

    International Nuclear Information System (INIS)

    Lee, Seung Joon; Langhans, Sigrid A

    2012-01-01

    Curcumin (diferuloylmethane), the yellow pigment in the Asian spice turmeric, is a hydrophobic polyphenol from the rhizome of Curcuma longa. Because of its chemopreventive and chemotherapeutic potential with no discernable side effects, it has become one of the major natural agents being developed for cancer therapy. Accumulating evidence suggests that curcumin induces cell death through activation of apoptotic pathways and inhibition of cell growth and proliferation. The mitotic checkpoint, or spindle assembly checkpoint (SAC), is the major cell cycle control mechanism to delay the onset of anaphase during mitosis. One of the key regulators of the SAC is the anaphase promoting complex/cyclosome (APC/C) which ubiquitinates cyclin B and securin and targets them for proteolysis. Because APC/C not only ensures cell cycle arrest upon spindle disruption but also promotes cell death in response to prolonged mitotic arrest, it has become an attractive drug target in cancer therapy. Cell cycle profiles were determined in control and curcumin-treated medulloblastoma and various other cancer cell lines. Pull-down assays were used to confirm curcumin binding. APC/C activity was determined using an in vitro APC activity assay. We identified Cdc27/APC3, a component of the APC/C, as a novel molecular target of curcumin and showed that curcumin binds to and crosslinks Cdc27 to affect APC/C function. We further provide evidence that curcumin preferably induces apoptosis in cells expressing phosphorylated Cdc27 usually found in highly proliferating cells. We report that curcumin directly targets the SAC to induce apoptosis preferably in cells with high levels of phosphorylated Cdc27. Our studies provide a possible molecular mechanism why curcumin induces apoptosis preferentially in cancer cells and suggest that phosphorylation of Cdc27 could be used as a biomarker to predict the therapeutic response of cancer cells to curcumin

  20. Anaphase-promoting complex/cyclosome protein Cdc27 is a target for curcumin-induced cell cycle arrest and apoptosis

    Directory of Open Access Journals (Sweden)

    Lee Seung Joon

    2012-01-01

    Full Text Available Abstract Background Curcumin (diferuloylmethane, the yellow pigment in the Asian spice turmeric, is a hydrophobic polyphenol from the rhizome of Curcuma longa. Because of its chemopreventive and chemotherapeutic potential with no discernable side effects, it has become one of the major natural agents being developed for cancer therapy. Accumulating evidence suggests that curcumin induces cell death through activation of apoptotic pathways and inhibition of cell growth and proliferation. The mitotic checkpoint, or spindle assembly checkpoint (SAC, is the major cell cycle control mechanism to delay the onset of anaphase during mitosis. One of the key regulators of the SAC is the anaphase promoting complex/cyclosome (APC/C which ubiquitinates cyclin B and securin and targets them for proteolysis. Because APC/C not only ensures cell cycle arrest upon spindle disruption but also promotes cell death in response to prolonged mitotic arrest, it has become an attractive drug target in cancer therapy. Methods Cell cycle profiles were determined in control and curcumin-treated medulloblastoma and various other cancer cell lines. Pull-down assays were used to confirm curcumin binding. APC/C activity was determined using an in vitro APC activity assay. Results We identified Cdc27/APC3, a component of the APC/C, as a novel molecular target of curcumin and showed that curcumin binds to and crosslinks Cdc27 to affect APC/C function. We further provide evidence that curcumin preferably induces apoptosis in cells expressing phosphorylated Cdc27 usually found in highly proliferating cells. Conclusions We report that curcumin directly targets the SAC to induce apoptosis preferably in cells with high levels of phosphorylated Cdc27. Our studies provide a possible molecular mechanism why curcumin induces apoptosis preferentially in cancer cells and suggest that phosphorylation of Cdc27 could be used as a biomarker to predict the therapeutic response of cancer cells to

  1. Phosphorylation of stress protein pp80 is related to promotion of transformation

    International Nuclear Information System (INIS)

    Smith, B.M.; Gindhart, T.D.; Hirano, K.; Colburn, N.H.

    1986-01-01

    The JB6 mouse epidermal cell system is an in vitro model of late stage promotion, and includes cell lines sensitive (P+) or resistant (P-) to phorbol ester-induced anchorage independent transformation, and transformed (T/sub x/) lines. Certain promoter-induced changes in phosphoproteins, identified by gel electrophoresis, are unique to cells of one phenotype, and occur only with specific promoters. An 80Kd protein is inversely correlated with phenotype: P- cells have a constitutively higher level (p 35 S-methionine. pp80 shares properties with the 80Kd heat stress protein: molecular weight relative abundance, and isoelectric point (4.5). Pharmacological analogs of calcium, the lanthanides, promote transformation of JB6 cells, but have no effect on phosphorylation of the 80Kd protein. If pp80 is on the promotion pathway, it is limited to a specific subset of transformation promoters

  2. Transport proteins promoting Escherichia coli pathogenesis

    Science.gov (United States)

    Tang, Fengyi; Saier, Milton H.

    2014-01-01

    Escherichia coli is a genetically diverse species infecting hundreds of millions of people worldwide annually. We examined seven well-characterized E. coli pathogens causing urinary tract infections, gastroenteritis, pyelonephritis and haemorrhagic colitis. Their transport proteins were identified and compared with each other and a non-pathogenic E. coli K12 strain to identify transport proteins related to pathogenesis. Each pathogen possesses a unique set of protein secretion systems for export to the cell surface or for injecting effector proteins into host cells. Pathogens have increased numbers of iron siderophore receptors and ABC iron uptake transporters, but the numbers and types of low-affinity secondary iron carriers were uniform in all strains. The presence of outer membrane iron complex receptors and high-affinity ABC iron uptake systems correlated, suggesting co-evolution. Each pathovar encodes a different set of pore-forming toxins and virulence-related outer membrane proteins lacking in K12. Intracellular pathogens proved to have a characteristically distinctive set of nutrient uptake porters, different from those of extracellular pathogens. The results presented in this report provide information about transport systems relevant to various types of E. coli pathogenesis that can be exploited in future basic and applied studies. PMID:24747185

  3. Transport proteins promoting Escherichia coli pathogenesis.

    Science.gov (United States)

    Tang, Fengyi; Saier, Milton H

    2014-01-01

    Escherichia coli is a genetically diverse species infecting hundreds of millions of people worldwide annually. We examined seven well-characterized E. coli pathogens causing urinary tract infections, gastroenteritis, pyelonephritis and haemorrhagic colitis. Their transport proteins were identified and compared with each other and a non-pathogenic E. coli K12 strain to identify transport proteins related to pathogenesis. Each pathogen possesses a unique set of protein secretion systems for export to the cell surface or for injecting effector proteins into host cells. Pathogens have increased numbers of iron siderophore receptors and ABC iron uptake transporters, but the numbers and types of low-affinity secondary iron carriers were uniform in all strains. The presence of outer membrane iron complex receptors and high-affinity ABC iron uptake systems correlated, suggesting co-evolution. Each pathovar encodes a different set of pore-forming toxins and virulence-related outer membrane proteins lacking in K12. Intracellular pathogens proved to have a characteristically distinctive set of nutrient uptake porters, different from those of extracellular pathogens. The results presented in this report provide information about transport systems relevant to various types of E. coli pathogenesis that can be exploited in future basic and applied studies. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. The heat shock protein-90 co-chaperone, Cyclophilin 40, promotes ALK-positive, anaplastic large cell lymphoma viability and its expression is regulated by the NPM-ALK oncoprotein

    International Nuclear Information System (INIS)

    Pearson, Joel D; Mohammed, Zubair; Bacani, Julinor T C; Lai, Raymond; Ingham, Robert J

    2012-01-01

    Anaplastic lymphoma kinase-positive, anaplastic large cell lymphoma (ALK+ ALCL) is a T cell lymphoma defined by the presence of chromosomal translocations involving the ALK tyrosine kinase gene. These translocations generate fusion proteins (e.g. NPM-ALK) with constitutive tyrosine kinase activity, which activate numerous signalling pathways important for ALK+ ALCL pathogenesis. The molecular chaperone heat shock protein-90 (Hsp90) plays a critical role in allowing NPM-ALK and other signalling proteins to function in this lymphoma. Co-chaperone proteins are important for helping Hsp90 fold proteins and for directing Hsp90 to specific clients; however the importance of co-chaperone proteins in ALK+ ALCL has not been investigated. Our preliminary findings suggested that expression of the immunophilin co-chaperone, Cyclophilin 40 (Cyp40), is up-regulated in ALK+ ALCL by JunB, a transcription factor activated by NPM-ALK signalling. In this study we examined the regulation of the immunophilin family of co-chaperones by NPM-ALK and JunB, and investigated whether the immunophilin co-chaperones promote the viability of ALK+ ALCL cell lines. NPM-ALK and JunB were knocked-down in ALK+ ALCL cell lines with siRNA, and the effect on the expression of the three immunophilin co-chaperones: Cyp40, FK506-binding protein (FKBP) 51, and FKBP52 examined. Furthermore, the effect of knock-down of the immunophilin co-chaperones, either individually or in combination, on the viability of ALK+ ALCL cell lines and NPM-ALK levels and activity was also examined. We found that NPM-ALK promoted the transcription of Cyp40 and FKBP52, but only Cyp40 transcription was promoted by JunB. We also observed reduced viability of ALK+ ALCL cell lines treated with Cyp40 siRNA, but not with siRNAs directed against FKBP52 or FKBP51. Finally, we demonstrate that the decrease in the viability of ALK+ ALCL cell lines treated with Cyp40 siRNA does not appear to be due to a decrease in NPM-ALK levels or the

  5. Cyclic AMP-Responsive Element-Binding Protein (CREB is Critical in Autoimmunity by Promoting Th17 but Inhibiting Treg Cell Differentiation

    Directory of Open Access Journals (Sweden)

    Xiaohu Wang

    2017-11-01

    Full Text Available The molecular mechanisms that govern differential T cell development into pro-inflammatory Th17 vs. regulatory T (Treg cells remain unclear. Here, we show that selective deletion of CREB in T cells or Th17 cells impaired Th17 cell differentiation in vitro and in vivo, and led to resistance to autoimmune diseases. Mechanistically, CREB, activated by CD3-PKC-ϴ signaling, plays a key role in regulating Th17 cell differentiation, at least in part through directly binding to the Il17-Il17f gene locus. Unexpectedly, although dispensable for FOXP3 expression and for the homeostasis and suppressive function of thymus-derived Treg cells, CREB negatively regulates the survival of TGF-β-induced Treg cells, and deletion of CREB resulted in increased FOXP3+ Treg cells in the intestine and protection in a colitis model. Thus, CREB is critical in autoimmune diseases by promoting Th17 cell and inhibiting de novo Treg cell generation.

  6. DPL-1 DP, LIN-35 Rb and EFL-1 E2F act with the MCD-1 zinc-finger protein to promote programmed cell death in Caenorhabditis elegans.

    Science.gov (United States)

    Reddien, Peter W; Andersen, Erik C; Huang, Michael C; Horvitz, H Robert

    2007-04-01

    The genes egl-1, ced-9, ced-4, and ced-3 play major roles in programmed cell death in Caenorhabditis elegans. To identify genes that have more subtle activities, we sought mutations that confer strong cell-death defects in a genetically sensitized mutant background. Specifically, we screened for mutations that enhance the cell-death defects caused by a partial loss-of-function allele of the ced-3 caspase gene. We identified mutations in two genes not previously known to affect cell death, dpl-1 and mcd-1 (modifier of cell death). dpl-1 encodes the C. elegans homolog of DP, the human E2F-heterodimerization partner. By testing genes known to interact with dpl-1, we identified roles in cell death for four additional genes: efl-1 E2F, lin-35 Rb, lin-37 Mip40, and lin-52 dLin52. mcd-1 encodes a novel protein that contains one zinc finger and that is synthetically required with lin-35 Rb for animal viability. dpl-1 and mcd-1 act with efl-1 E2F and lin-35 Rb to promote programmed cell death and do so by regulating the killing process rather than by affecting the decision between survival and death. We propose that the DPL-1 DP, MCD-1 zinc finger, EFL-1 E2F, LIN-35 Rb, LIN-37 Mip40, and LIN-52 dLin52 proteins act together in transcriptional regulation to promote programmed cell death.

  7. Transcriptional Inhibition of Matrix Metal loproteinase 9 (MMP-9 Activity by a c-fos/Estrogen Receptor Fusion Protein is Mediated by the Proximal AP-1 Site of the MMP-9 Promoter and Correlates with Reduced Tumor Cell Invasion

    Directory of Open Access Journals (Sweden)

    David L. Crowe

    1999-10-01

    Full Text Available Tumor cell invasion of basement membranes is one of the hallmarks of malignant transformation. Tumor cells secrete proteolytic enzymes known as matrix metalloproteinases (MMPs which degrade extracellular matrix molecules. Increased expression of MMP-9 has been associated with acquisition of invasive phenotype in many tumors. However, multiple mechanisms for regulation of MMP-9 gene expression by tumor cell lines have been proposed. A number of transcription factor binding sites have been characterized in the upstream regulatory region of the MMP-9 gene, including those for AP-1. To determine how a specific AP-1 family member, c-fos, regulates MMP-9 promoter activity through these sites, we used an expression vector containing the c-fos coding region fused to the estrogen receptor (ER ligand binding domain. This construct is activated upon binding estradiol. Stable expression of this construct in ER negative squamous cell carcinoma (SCC lines produced an estradiol dependent decrease in the number of cells that migrated through a reconstituted basement membrane. This decreased invasiveness was accompanied by estradiol dependent downregulation of MMP-9 activity as determined by gelatin zymography. Estradiol also produced transcriptional downregulation of an MMP-9 promoter construct in cells transiently transfected with the c-fosER expression vector. This downregulation was mediated by the AP-1 site at —79 by in the MMP-9 promoter. We concluded that the proximal AP-1 site mediated the transcriptional downregulation of the MMP-9 promoter by a conditionally activated c-fos fusion protein.

  8. Identification of Insulin-Like Growth Factor-I Receptor (IGF-IR) Gene Promoter-Binding Proteins in Estrogen Receptor (ER)-Positive and ER-Depleted Breast Cancer Cells

    International Nuclear Information System (INIS)

    Sarfstein, Rive; Belfiore, Antonino; Werner, Haim

    2010-01-01

    The insulin-like growth factor I receptor (IGF-IR) has been implicated in the etiology of breast cancer. Overexpression of the IGF-IR gene is a typical feature of most primary breast cancers, whereas low IGF-IR levels are seen at advanced stages. Hence, evaluation of IGF-IR levels might be important for assessing prognosis. In the present study, we employed a proteomic approach based on DNA affinity chromatography followed either by mass spectroscopy (MS) or Western blot analysis to identify transcription factors that may associate with the IGF-IR promoter in estrogen receptor (ER)-positive and ER-depleted breast cancer cells. A biotinylated IGF-IR promoter fragment was bound to streptavidin magnetic beads and incubated with nuclear extracts of breast cancer cells. IGF-IR promoter-binding proteins were eluted with high salt and analyzed by MS and Western blots. Among the proteins that were found to bind to the IGF-IR promoter we identified zinc finger transcription factors Sp1 and KLF6, ER-α, p53, c-jun, and poly (ADP-ribosylation) polymerase. Furthermore, chromatin immune-precipitation (ChIP) analysis confirmed the direct in vivo binding of some of these transcription factors to IGF-IR promoter DNA. The functional relevance of binding data was assessed by cotransfection experiments with specific expression vectors along with an IGF-IR promoter reporter. In summary, we identified nuclear proteins that are potentially responsible for the differential expression of the IGF-IR gene in ER-positive and ER-depleted breast cancer cells

  9. Identification of Insulin-Like Growth Factor-I Receptor (IGF-IR) Gene Promoter-Binding Proteins in Estrogen Receptor (ER)-Positive and ER-Depleted Breast Cancer Cells

    Energy Technology Data Exchange (ETDEWEB)

    Sarfstein, Rive [Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978 (Israel); Belfiore, Antonino [Department of Clinical and Experimental Medicine, University Magna Graecia of Catanzaro, Catanzaro 88100 (Italy); Werner, Haim, E-mail: hwerner@post.tau.ac.il [Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978 (Israel)

    2010-03-25

    The insulin-like growth factor I receptor (IGF-IR) has been implicated in the etiology of breast cancer. Overexpression of the IGF-IR gene is a typical feature of most primary breast cancers, whereas low IGF-IR levels are seen at advanced stages. Hence, evaluation of IGF-IR levels might be important for assessing prognosis. In the present study, we employed a proteomic approach based on DNA affinity chromatography followed either by mass spectroscopy (MS) or Western blot analysis to identify transcription factors that may associate with the IGF-IR promoter in estrogen receptor (ER)-positive and ER-depleted breast cancer cells. A biotinylated IGF-IR promoter fragment was bound to streptavidin magnetic beads and incubated with nuclear extracts of breast cancer cells. IGF-IR promoter-binding proteins were eluted with high salt and analyzed by MS and Western blots. Among the proteins that were found to bind to the IGF-IR promoter we identified zinc finger transcription factors Sp1 and KLF6, ER-α, p53, c-jun, and poly (ADP-ribosylation) polymerase. Furthermore, chromatin immune-precipitation (ChIP) analysis confirmed the direct in vivo binding of some of these transcription factors to IGF-IR promoter DNA. The functional relevance of binding data was assessed by cotransfection experiments with specific expression vectors along with an IGF-IR promoter reporter. In summary, we identified nuclear proteins that are potentially responsible for the differential expression of the IGF-IR gene in ER-positive and ER-depleted breast cancer cells.

  10. High Glucose Promotes Tumor Invasion and Increases Metastasis-Associated Protein Expression in Human Lung Epithelial Cells by Upregulating Heme Oxygenase-1 via Reactive Oxygen Species or the TGF-β1/PI3K/Akt Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Xiaowen Kang

    2015-02-01

    Full Text Available Background: Growing evidence indicates that heme oxygenase-1 (HO-1 is up-regulated in malignancies and subsequently alters tumor aggressiveness and various cancer-related factors, such as high glucose (HG levels. HO-1 expression can be induced when glucose concentrations are above 25 mM; however, the role of HO-1 in lung cancer patients with diabetes remains unknown. Therefore, in this study we investigated the promotion of tumor cell invasion and the expression of metastasis-associated proteins by inducing the up-regulation of HO-1 expression by HG treatment in A549 human lung epithelial cells. Methods: The expression of HO-1and metastasis-associated protein expression was explored by western blot analysis. HO-1 enzymatic activity, reactive oxygen species (ROS production and TGF-β1 production were examined by ELISA. Invasiveness was analyzed using a Transwell chamber. Results: HG treatment of A549 cells induced an increase in HO-1 expression, which was mediated by the HG-induced generation of reactive oxygen species (ROS and transforming growth factor-β1 (TGF-β1 in a concentration- and time-dependent manner. Following the increase in HO-1 expression, the enzymatic activity of HO-1 also increased in HG-treated cells. Pretreatment with N-acetyl-L-cysteine (NAC or with phosphatidylinositol 3-kinase (PI3K/Akt inhibitors attenuated the HG-induced increase in HO-1 expression. HG treatment of A549 cells enhanced the invasion potential of these cells, as shown with a Transwell assay, and increased metastasis-associated protein expression. However, HO-1 siRNA transfection significantly decreased these capabilities. Conclusion: this study is the first to demonstrate that HG treatment of A549 human lung epithelial cells promotes tumor cell invasion and increases metastasis-associated protein expression by up-regulating HO-1 expression via ROS or the TGF-β1/PI3K/Akt signaling pathway.

  11. The group B streptococcal alpha C protein binds alpha1beta1-integrin through a novel KTD motif that promotes internalization of GBS within human epithelial cells.

    Science.gov (United States)

    Bolduc, Gilles R; Madoff, Lawrence C

    2007-12-01

    Group B Streptococcus (GBS) is the leading cause of bacterial pneumonia, sepsis and meningitis among neonates and a cause of morbidity among pregnant women and immunocompromised adults. GBS epithelial cell invasion is associated with expression of alpha C protein (ACP). Loss of ACP expression results in a decrease in GBS internalization and translocation across human cervical epithelial cells (ME180). Soluble ACP and its 170 amino acid N-terminal region (NtACP), but not the repeat protein RR', bind to ME180 cells and reduce internalization of wild-type GBS to levels obtained with an ACP-deficient isogenic mutant. In the current study, ACP colocalized with alpha(1)beta(1)-integrin, resulting in integrin clustering as determined by laser scanning confocal microscopy. NtACP contains two structural domains, D1 and D2. D1 is structurally similar to fibronectin's integrin-binding region (FnIII10). D1's (KT)D146 motif is structurally similar to the FnIII10 (RG)D1495 integrin-binding motif, suggesting that ACP binds alpha(1)beta(1)-integrin via the D1 domain. The (KT)D146A mutation within soluble NtACP reduced its ability to bind alpha(1)beta(1)-integrin and inhibit GBS internalization within ME180 cells. Thus ACP binding to human epithelial cell integrins appears to contribute to GBS internalization within epithelial cells.

  12. The C. elegans Spalt-like protein SEM-4 functions through the SoxC transcription factor SEM-2 to promote a proliferative blast cell fate in the postembryonic mesoderm.

    Science.gov (United States)

    Shen, Qinfang; Shi, Herong; Tian, Chenxi; Ghai, Vikas; Liu, Jun

    2017-09-01

    Proper development of a multicellular organism relies on well-coordinated regulation of cell fate specification, cell proliferation and cell differentiation. The C. elegans postembryonic mesoderm provides a useful system for uncovering factors involved in these processes and for further dissecting their regulatory relationships. The single Spalt-like zinc finger containing protein SEM-4/SALL is known to be involved in specifying the proliferative sex myoblast (SM) fate. We have found that SEM-4/SALL is sufficient to promote the SM fate and that it does so in a cell autonomous manner. We further showed that SEM-4/SALL acts through the SoxC transcription factor SEM-2 to promote the SM fate. SEM-2 is known to promote the SM fate by inhibiting the expression of two BWM-specifying transcription factors. In light of recent findings in mammals showing that Sall4, one of the mammalian homologs of SEM-4, contributes to pluripotency regulation by inhibiting differentiation, our work suggests that the function of SEM-4/SALL proteins in regulating pluripotency versus differentiation appears to be evolutionarily conserved. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Health issues of whey proteins: 3. gut health promotion

    NARCIS (Netherlands)

    Gertjan Schaafsma

    2007-01-01

    This paper reviews the potential of whey protein to promote gut health. The high digestibility and specific amino acid composition of whey protein, as present in whey powder, whey protein concentrate and whey protein isolate, explain why ingestion of whey protein will exert this beneficial effect.

  14. The cAMP signaling system inhibits the repair of {gamma}-ray-induced DNA damage by promoting Epac1-mediated proteasomal degradation of XRCC1 protein in human lung cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Eun-Ah [Department of Biochemistry and Molecular Biology, Cancer Research Center, Seoul National University College of Medicine, Seoul 110-799 (Korea, Republic of); Juhnn, Yong-Sung, E-mail: juhnn@snu.ac.kr [Department of Biochemistry and Molecular Biology, Cancer Research Center, Seoul National University College of Medicine, Seoul 110-799 (Korea, Republic of)

    2012-06-01

    Highlights: Black-Right-Pointing-Pointer cAMP signaling system inhibits repair of {gamma}-ray-induced DNA damage. Black-Right-Pointing-Pointer cAMP signaling system inhibits DNA damage repair by decreasing XRCC1 expression. Black-Right-Pointing-Pointer cAMP signaling system decreases XRCC1 expression by promoting its proteasomal degradation. Black-Right-Pointing-Pointer The promotion of XRCC1 degradation by cAMP signaling system is mediated by Epac1. -- Abstract: Cyclic AMP is involved in the regulation of metabolism, gene expression, cellular growth and proliferation. Recently, the cAMP signaling system was found to modulate DNA-damaging agent-induced apoptosis by regulating the expression of Bcl-2 family proteins and inhibitors of apoptosis. Thus, we hypothesized that the cAMP signaling may modulate DNA repair activity, and we investigated the effects of the cAMP signaling system on {gamma}-ray-induced DNA damage repair in lung cancer cells. Transient expression of a constitutively active mutant of stimulatory G protein (G{alpha}sQL) or treatment with forskolin, an adenylyl cyclase activator, augmented radiation-induced DNA damage and inhibited repair of the damage in H1299 lung cancer cells. Expression of G{alpha}sQL or treatment with forskolin or isoproterenol inhibited the radiation-induced expression of the XRCC1 protein, and exogenous expression of XRCC1 abolished the DNA repair-inhibiting effect of forskolin. Forskolin treatment promoted the ubiquitin and proteasome-dependent degradation of the XRCC1 protein, resulting in a significant decrease in the half-life of the protein after {gamma}-ray irradiation. The effect of forskolin on XRCC1 expression was not inhibited by PKA inhibitor, but 8-pCPT-2 Prime -O-Me-cAMP, an Epac-selective cAMP analog, increased ubiquitination of XRCC1 protein and decreased XRCC1 expression. Knockdown of Epac1 abolished the effect of 8-pCPT-2 Prime -O-Me-cAMP and restored XRCC1 protein level following {gamma}-ray irradiation. From

  15. Distinct p300-responsive mechanisms promote caspase-dependent apoptosis by human T-cell lymphotropic virus type 1 Tax protein.

    Science.gov (United States)

    Nicot, C; Harrod, R

    2000-11-01

    The dysregulation of cellular apoptosis pathways has emerged as a critical early event associated with the development of many types of human cancers. Numerous viral and cellular oncogenes, aside from their inherent transforming properties, are known to induce programmed cell death, consistent with the hypothesis that genetic defects are required to support tumor survival. Here, we report that nuclear expression of the CREB-binding protein (CBP)/p300-binding domain of the human T-cell lymphotropic virus type 1 (HTLV-1) transactivator, Tax, triggers an apoptotic death-inducing signal during short-term clonal analyses, as well as in transient cell death assays. Coexpression of the antiapoptotic factor Bcl-2 increased serum stimulation; incubation with the chemical caspase inhibitor z-Val-Ala-DL-Asp fluoromethylketone antagonized Tax-induced cell death. The CBP/p300-binding defective Tax mutants K88A and V89A exhibited markedly reduced cytotoxic effects compared to the wild-type Tax protein. Importantly, nuclear expression of the minimal CBP/p300-binding peptide of Tax induced apoptosis in the absence of Tax-dependent transcriptional activities, while its K88A counterpart did not cause cell death. Further, Tax-mediated apoptosis was effectively prevented by ectopic expression of the p300 coactivator. We also report that activation of the NF-kappaB transcription pathway by Tax, under growth arrest conditions, results in apoptosis that occurs independent of direct Tax coactivator effects. Our results allude to a novel pivotal role for the transcriptional coactivator p300 in determining cell fate and raise the possibility that dysregulated coactivator usage may pose an early barrier to transformation that must be selectively overcome as a prerequisite for the initiation of neoplasia.

  16. Src Induces Podoplanin Expression to Promote Cell Migration*

    Science.gov (United States)

    Shen, Yongquan; Chen, Chen-Shan; Ichikawa, Hitoshi; Goldberg, Gary S.

    2010-01-01

    Nontransformed cells can force tumor cells to assume a normal morphology and phenotype by the process of contact normalization. Transformed cells must escape this process to become invasive and malignant. However, mechanisms underlying contact normalization have not been elucidated. Here, we have identified genes that are affected by contact normalization of Src-transformed cells. Tumor cells must migrate to become invasive and malignant. Src must phosphorylate the adaptor protein Cas (Crk-associated substrate) to promote tumor cell motility. We report here that Src utilizes Cas to induce podoplanin (Pdpn) expression to promote tumor cell migration. Pdpn is a membrane-bound extracellular glycoprotein that associates with endogenous ligands to promote tumor cell migration leading to cancer invasion and metastasis. In fact, Pdpn expression accounted for a major part of the increased migration seen in Src-transformed cells. Moreover, nontransformed cells suppressed Pdpn expression in adjacent Src-transformed cells. Of >39,000 genes, Pdpn was one of only 23 genes found to be induced by transforming Src activity and suppressed by contact normalization of Src-transformed cells. In addition, we found 16 genes suppressed by Src and induced by contact normalization. These genes encode growth factor receptors, adaptor proteins, and products that have not yet been annotated and may play important roles in tumor cell growth and migration. PMID:20123990

  17. Nitric oxide synthesis-promoting effects of valsartan in human umbilical vein endothelial cells via the Akt/adenosine monophosphate-activated protein kinase/endothelial nitric oxide synthase pathway

    Directory of Open Access Journals (Sweden)

    Yingshuai Zhao

    2017-05-01

    Full Text Available Valsartan (VAL, an antagonist of angiotensin II receptor type 1, has antihypertensive and multiple cardiovascular protective effects. The pleiotropic functions of VAL are related to the increased synthesis and biological activity of intravascular nitric oxide (NO. In this study, the role and mechanisms of VAL in the synthesis of NO were examined in human umbilical vein endothelial cells (HUVECs. Ten µmol/L of VAL was used to treat EA.hy926 cells for 30 minutes, 1, 3, 6, 12, and 24 hours, and three concentrations of VAL (i.e., 10, 1, and 0.1 µmol/L were used to treat EA.hy926 cells for 24 hours. The cells were divided into five groups: control, VAL, VAL + Compound C (adenosine monophosphate-activated protein kinase [AMPK] inhibitor, 1 µmol/L, VAL + LY294002 (Akt [protein kinase B] inhibitor, 10 µmol/L, and VAL + L-nitro-arginine methyl ester (L-NAME, endothelial NO synthase [eNOS] inhibitor, 500 µmol/L groups. The NO content in the VAL-treated HUVEC line (EA.hy926 was detected using the nitrate reductase method, and western blot was used to detect the phosphorylation of Akt, AMPK, and eNOS, as well as the changes in total protein levels. VAL increased NO synthesis in EA.hy926 cells in time- and dose-dependent manners (p < 0.05 and the intracellular phosphorylation levels of Akt, AMPK, and eNOS at the corresponding time points. LY294002, Compound C, and L-NAME could inhibit the VAL-promoted NO synthesis. VAL activated Akt, AMPK, and eNOS, thus promoting NO synthesis and playing a protective role in endothelial cells. These results partially explained the mechanisms underlying the cardiovascular protective effects of VAL.

  18. Co-targeting Deoxyribonucleic Acid–Dependent Protein Kinase and Poly(Adenosine Diphosphate-Ribose) Polymerase-1 Promotes Accelerated Senescence of Irradiated Cancer Cells

    Energy Technology Data Exchange (ETDEWEB)

    Azad, Arun, E-mail: arun.azad@bccancer.bc.ca [Division of Cancer Research, Peter MacCallum Cancer Centre, East Melbourne, Victoria (Australia); Department of Pathology, St. Vincent' s Hospital, University of Melbourne, Parkville, Victoria (Australia); Bukczynska, Patricia; Jackson, Susan [Division of Cancer Research, Peter MacCallum Cancer Centre, East Melbourne, Victoria (Australia); Haput, Ygal; Cullinane, Carleen [Division of Cancer Research, Peter MacCallum Cancer Centre, East Melbourne, Victoria (Australia); Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, Victoria (Australia); McArthur, Grant A.; Solomon, Benjamin [Division of Cancer Research, Peter MacCallum Cancer Centre, East Melbourne, Victoria (Australia); Division of Cancer Medicine, Peter MacCallum Cancer Centre, East Melbourne, Victoria (Australia); Department of Medicine, St. Vincent' s Hospital, University of Melbourne, Parkville, Victoria (Australia); Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, Victoria (Australia)

    2014-02-01

    Purpose: To examine the effects of combined blockade of DNA-dependent protein kinase (DNA-PK) and poly(adenosine diphosphate-ribose) polymerase-1 (PARP-1) on accelerated senescence in irradiated H460 and A549 non-small cell lung cancer cells. Methods and Materials: The effects of KU5788 and AG014699 (inhibitors of DNA-PK and PARP-1, respectively) on clonogenic survival, DNA double-strand breaks (DSBs), apoptosis, mitotic catastrophe, and accelerated senescence in irradiated cells were examined in vitro. For in vivo experiments, H460 xenografts established in athymic nude mice were treated with BEZ235 (a DNA-PK, ATM, and phosphatidylinositol 3-kinase/mammalian target of rapamycin inhibitor) and AG014699 to determine effects on proliferation, DNA DSBs, and accelerated senescence after radiation. Results: Compared with either inhibitor alone, combination treatment with KU57788 and AG014699 reduced postradiation clonogenic survival and significantly increased persistence of Gamma-H2AX (γH2AX) foci in irradiated H460 and A549 cells. Notably, these effects coincided with the induction of accelerated senescence in irradiated cells as reflected by positive β-galactosidase staining, G2-M cell-cycle arrest, enlarged and flattened cellular morphology, increased p21 expression, and senescence-associated cytokine secretion. In irradiated H460 xenografts, concurrent therapy with BEZ235 and AG014699 resulted in sustained Gamma-H2AX (γH2AX) staining and prominent β-galactosidase activity. Conclusion: Combined DNA-PK and PARP-1 blockade increased tumor cell radiosensitivity and enhanced the prosenescent properties of ionizing radiation in vitro and in vivo. These data provide a rationale for further preclinical and clinical testing of this therapeutic combination.

  19. Co-targeting Deoxyribonucleic Acid–Dependent Protein Kinase and Poly(Adenosine Diphosphate-Ribose) Polymerase-1 Promotes Accelerated Senescence of Irradiated Cancer Cells

    International Nuclear Information System (INIS)

    Azad, Arun; Bukczynska, Patricia; Jackson, Susan; Haput, Ygal; Cullinane, Carleen; McArthur, Grant A.; Solomon, Benjamin

    2014-01-01

    Purpose: To examine the effects of combined blockade of DNA-dependent protein kinase (DNA-PK) and poly(adenosine diphosphate-ribose) polymerase-1 (PARP-1) on accelerated senescence in irradiated H460 and A549 non-small cell lung cancer cells. Methods and Materials: The effects of KU5788 and AG014699 (inhibitors of DNA-PK and PARP-1, respectively) on clonogenic survival, DNA double-strand breaks (DSBs), apoptosis, mitotic catastrophe, and accelerated senescence in irradiated cells were examined in vitro. For in vivo experiments, H460 xenografts established in athymic nude mice were treated with BEZ235 (a DNA-PK, ATM, and phosphatidylinositol 3-kinase/mammalian target of rapamycin inhibitor) and AG014699 to determine effects on proliferation, DNA DSBs, and accelerated senescence after radiation. Results: Compared with either inhibitor alone, combination treatment with KU57788 and AG014699 reduced postradiation clonogenic survival and significantly increased persistence of Gamma-H2AX (γH2AX) foci in irradiated H460 and A549 cells. Notably, these effects coincided with the induction of accelerated senescence in irradiated cells as reflected by positive β-galactosidase staining, G2-M cell-cycle arrest, enlarged and flattened cellular morphology, increased p21 expression, and senescence-associated cytokine secretion. In irradiated H460 xenografts, concurrent therapy with BEZ235 and AG014699 resulted in sustained Gamma-H2AX (γH2AX) staining and prominent β-galactosidase activity. Conclusion: Combined DNA-PK and PARP-1 blockade increased tumor cell radiosensitivity and enhanced the prosenescent properties of ionizing radiation in vitro and in vivo. These data provide a rationale for further preclinical and clinical testing of this therapeutic combination

  20. Health issues of whey proteins: 3. Gut health promotion

    NARCIS (Netherlands)

    Schaafsma, G.

    2007-01-01

    This paper reviews the potential of whey protein to promote gut health. The high digestibility and specific amino acid composition of whey protei, as present in whey powder, whey protein concentrate and whey protein isolate, explain why ingestion of whey protein will exert this beneficial effect.

  1. Nanopolymers Delivery of the Bone Morphogenetic Protein-4 Plasmid to Mesenchymal Stem Cells Promotes Articular Cartilage Repair In Vitro and In Vivo

    Directory of Open Access Journals (Sweden)

    Junjun Shi

    2012-01-01

    Full Text Available The clinical application of viral vectors for gene therapy is limited for biosafety consideration. In this study, to promote articular cartilage repair, poly (lactic-co glycolic acid (PLGA nanopolymers were used as non-viral vectors to transfect rabbit mesenchymal stem cells (MSCs with the pDC316-BMP4-EGFP plasmid. The cytotoxicity and transfection efficiency in vitro were acceptable measuring by CCK-8 and flow cytometry. After transfection, Chondrogenic markers (mRNA of Col2a1, Sox9, Bmp4, and Agg of experimental cells (MSCs being transfected with BMP-4 plasmid by PLGA nanopolymers were increased more than those of control cells (MSCs being transfected with naked BMP-4 plasmid alone. In vivo study, twelve rabbits (24 knees with large full thickness articular cartilage defects were randomly divided into the experimental group (MSCs being transfected with BMP-4 plasmid by PLGA nanopolymers and the control group (MSCs being transfected with naked BMP-4 plasmid. The experimental group showed better regeneration than the control group 6 and 12 weeks postoperatively. Hyaline-like cartilage formed at week 12 in the experimental group, indicating the local delivery of BMP-4 plasmid to MSCs by PLGA nanopolymers improved articular cartilage repair significantly. PLGA nanopolymers could be a promising and effective non-viral vector for gene therapy in cartilage repair.

  2. XIAP BIR domain suppresses miR-200a expression and subsequently promotes EGFR protein translation and anchorage-independent growth of bladder cancer cell

    Directory of Open Access Journals (Sweden)

    Chao Huang

    2017-01-01

    Full Text Available Abstract Background The X-linked inhibitor of apoptosis protein (XIAP is a well-known potent apoptosis suppressor and also participates in cancer cell biological behaviors, therefore attracting great attentions as a potential antineoplastic therapeutic target for past years. Anti-IAP therapy is reported to be closely related to epidermal growth factor receptor (EGFR expression level. However, whether and how XIAP modulates EGFR expression remains largely unknown. Methods Human XIAP was knockdown with short-hairpin RNA in two different bladder cancer cell lines, T24T and UMUC3. Two XIAP mutants, XIAP ∆BIR (deletion of N-terminal three BIR domains and XIAP ∆RING (deletion of C-terminal RING domain and keeping the function of BIR domains, were generated to determine which domain is involved in regulating EGFR. Results We found here that lacking of XIAP expression resulted in a remarkable suppression of EGFR expression, consequently leading to the deficiency of anchorage-independent cell growth. Further study demonstrated that BIR domain of XIAP was crucial for regulating the EGFR translation by suppressing the transcription and expression of miR-200a. Mechanistic studies indicated that BIR domain activated the protein phosphatase 2 (PP2A activity by decreasing the phosphorylation of PP2A at Tyr307 in its catalytic subunit, PP2A-C. Such activated PP2A prevented the deviant phosphorylation and activation of MAPK kinases/MAPKs, their downstream effector c-Jun, and in turn inhibiting transcription of c-Jun-regulated the miR-200a. Conclusions Our study uncovered a novel function of BIR domain of XIAP in regulating the EGFR translation, providing significant insight into the understanding of the XIAP overexpression in the cancer development and progression, further offering a new theoretical support for using XIAP BIR domain and EGFR as targets for cancer therapy.

  3. Low dose perfluorooctanoate exposure promotes cell proliferation in a human non-tumor liver cell line

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hongxia; Cui, Ruina [Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101 (China); Guo, Xuejiang [State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 210029 (China); Hu, Jiayue [Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101 (China); Dai, Jiayin, E-mail: daijy@ioz.ac.cn [Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101 (China)

    2016-08-05

    Highlights: • Differential expression of proteins induced by PFOA in HL-7702 was identified. • Most of the differentially expressed proteins are related to cell proliferation. • A low dose of PFOA stimulates HL-7702 cell proliferation. • A high dose of PFOA inhibits HL-7702 cell proliferation. - Abstract: Perfluorooctanoate (PFOA) is a well-known persistent organic pollutant widely found in the environment, wildlife and humans. Medical surveillance and experimental studies have investigated the potential effects of PFOA on human livers, but the hepatotoxicity of PFOA on humans and its underlying mechanism remain to be clarified. We exposed a human liver cell line (HL-7702) to 50 μM PFOA for 48 h and 96 h, and identified 111 significantly differentially expressed proteins by iTRAQ analysis. A total of 46 proteins were related to cell proliferation and apoptosis. Through further analysis of the cell cycle, apoptosis and their related proteins, we found that low doses of PFOA (50–100 μM) promoted cell proliferation and numbers by promoting cells from the G1 to S phases, whereas high doses of PFOA (200–400 μM) led to reduced HL-7702 cell numbers compared with that of the control mainly due to cell cycle arrest in the G0/G1 phase. To our knowledge, this is the first report on the promotion of cell cycle progression in human cells following PFOA exposure.

  4. Low dose perfluorooctanoate exposure promotes cell proliferation in a human non-tumor liver cell line

    International Nuclear Information System (INIS)

    Zhang, Hongxia; Cui, Ruina; Guo, Xuejiang; Hu, Jiayue; Dai, Jiayin

    2016-01-01

    Highlights: • Differential expression of proteins induced by PFOA in HL-7702 was identified. • Most of the differentially expressed proteins are related to cell proliferation. • A low dose of PFOA stimulates HL-7702 cell proliferation. • A high dose of PFOA inhibits HL-7702 cell proliferation. - Abstract: Perfluorooctanoate (PFOA) is a well-known persistent organic pollutant widely found in the environment, wildlife and humans. Medical surveillance and experimental studies have investigated the potential effects of PFOA on human livers, but the hepatotoxicity of PFOA on humans and its underlying mechanism remain to be clarified. We exposed a human liver cell line (HL-7702) to 50 μM PFOA for 48 h and 96 h, and identified 111 significantly differentially expressed proteins by iTRAQ analysis. A total of 46 proteins were related to cell proliferation and apoptosis. Through further analysis of the cell cycle, apoptosis and their related proteins, we found that low doses of PFOA (50–100 μM) promoted cell proliferation and numbers by promoting cells from the G1 to S phases, whereas high doses of PFOA (200–400 μM) led to reduced HL-7702 cell numbers compared with that of the control mainly due to cell cycle arrest in the G0/G1 phase. To our knowledge, this is the first report on the promotion of cell cycle progression in human cells following PFOA exposure.

  5. Destabilization of Akt Promotes the Death of Myeloma Cell Lines

    Directory of Open Access Journals (Sweden)

    Yanan Zhang

    2014-01-01

    Full Text Available Constitutive activation of Akt is believed to be an oncogenic signal in multiple myeloma and is associated with poor patient prognosis and resistance to available treatment. The stability of Akt proteins is regulated by phosphorylating the highly conserved turn motif (TM of these proteins and the chaperone protein HSP90. In this study we investigate the antitumor effects of inhibiting mTORC2 plus HSP90 in myeloma cell lines. We show that chronic exposure of cells to rapamycin can inhibit mTORC2 pathway, and AKT will be destabilized by administration of the HSP90 inhibitor 17-allylamino-geldanamycin (17-AAG. Finally, we show that the rapamycin synergizes with 17-AAG and inhibits myeloma cells growth and promotes cell death to a greater extent than either drug alone. Our studies provide a clinical rationale of use mTOR inhibitors and chaperone protein inhibitors in combination regimens for the treatment of human blood cancers.

  6. Promoters and proteins from Clostridium thermocellum and uses thereof

    Science.gov (United States)

    Wu, J. H. David; Newcomb, Michael

    2012-11-13

    The present invention relates to an inducible and a high expression nucleic acid promoter isolated from Clostridium thermocellum. These promoters are useful for directing expression of a protein or polypeptide encoded by a nucleic acid molecule operably associated with the nucleic acid promoters. The present invention also relates to nucleic acid constructs including the C. thermocellum promoters, and expression vectors and hosts containing such nucleic acid constructs. The present invention also relates to protein isolated from Clostridium thermocellum, including a repressor protein. The present invention also provides methods of using the isolated promoters and proteins from Clostridium thermocellum, including methods for directing inducible in vitro and in vivo expression of a protein or polypeptide in a host, and methods of producing ethanol from a cellulosic biomass.

  7. Hemidesmosomal linker proteins regulate cell motility, invasion and tumorigenicity in oral squamous cell carcinoma derived cells.

    Science.gov (United States)

    Chaudhari, Pratik Rajeev; Charles, Silvania Emlit; D'Souza, Zinia Charlotte; Vaidya, Milind Murlidhar

    2017-11-15

    BPAG1e and Plectin are hemidesmosomal linker proteins which anchor intermediate filament proteins to the cell surface through β4 integrin. Recent reports indicate that these proteins play a role in various cellular processes apart from their known anchoring function. However, the available literature is inconsistent. Further, the previous study from our laboratory suggested that Keratin8/18 pair promotes cell motility and tumor progression by deregulating β4 integrin signaling in oral squamous cell carcinoma (OSCC) derived cells. Based on these findings, we hypothesized that linker proteins may have a role in neoplastic progression of OSCC. Downregulation of hemidesmosomal linker proteins in OSCC derived cells resulted in reduced cell migration accompanied by alterations in actin organization. Further, decreased MMP9 activity led to reduced cell invasion in linker proteins knockdown cells. Moreover, loss of these proteins resulted in reduced tumorigenic potential. SWATH analysis demonstrated upregulation of N-Myc downstream regulated gene 1 (NDRG1) in linker proteins downregulated cells as compared to vector control cells. Further, the defects in phenotype upon linker proteins ablation were rescued upon loss of NDRG1 in linker proteins knockdown background. These data together indicate that hemidesmosomal linker proteins regulate cell motility, invasion and tumorigenicity possibly through NDRG1 in OSCC derived cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Toscana virus NSs protein promotes degradation of double-stranded RNA-dependent protein kinase.

    Science.gov (United States)

    Kalveram, Birte; Ikegami, Tetsuro

    2013-04-01

    Toscana virus (TOSV), which is transmitted by Phlebotomus spp. sandflies, is a major etiologic agent of aseptic meningitis and encephalitis in the Mediterranean. Like other members of the genus Phlebovirus of the family Bunyaviridae, TOSV encodes a nonstructural protein (NSs) in its small RNA segment. Although the NSs of Rift Valley fever virus (RVFV) has been identified as an important virulence factor, which suppresses host general transcription, inhibits transcription from the beta interferon promoter, and promotes the proteasomal degradation of double-stranded RNA-dependent protein kinase (PKR), little is known about the functions of NSs proteins encoded by less-pathogenic members of this genus. In this study we report that TOSV is able to downregulate PKR with similar efficiency as RVFV, while infection with the other phleboviruses-i.e., Punta Toro virus, sandfly fever Sicilian virus, or Frijoles virus-has no effect on cellular PKR levels. In contrast to RVFV, however, cellular transcription remains unaffected during TOSV infection. TOSV NSs protein promotes the proteasome-dependent downregulation of PKR and is able to interact with kinase-inactive PKR in infected cells.

  9. Mutation of Rice BC12/GDD1, Which Encodes a Kinesin-Like Protein That Binds to a GA Biosynthesis Gene Promoter, Leads to Dwarfism with Impaired Cell Elongation[W][OA

    Science.gov (United States)

    Li, Juan; Jiang, Jiafu; Qian, Qian; Xu, Yunyuan; Zhang, Cui; Xiao, Jun; Du, Cheng; Luo, Wei; Zou, Guoxing; Chen, Mingluan; Huang, Yunqing; Feng, Yuqi; Cheng, Zhukuan; Yuan, Ming; Chong, Kang

    2011-01-01

    The kinesins are a family of microtubule-based motor proteins that move directionally along microtubules and are involved in many crucial cellular processes, including cell elongation in plants. Less is known about kinesins directly regulating gene transcription to affect cellular physiological processes. Here, we describe a rice (Oryza sativa) mutant, gibberellin-deficient dwarf1 (gdd1), that has a phenotype of greatly reduced length of root, stems, spikes, and seeds. This reduced length is due to decreased cell elongation and can be rescued by exogenous gibberellic acid (GA3) treatment. GDD1 was cloned by a map-based approach, was expressed constitutively, and was found to encode the kinesin-like protein BRITTLE CULM12 (BC12). Microtubule cosedimentation assays revealed that BC12/GDD1 bound to microtubules in an ATP-dependent manner. Whole-genome microarray analysis revealed the expression of ent-kaurene oxidase (KO2), which encodes an enzyme involved in GA biosynthesis, was downregulated in gdd1. Electrophoretic mobility shift and chromatin immunoprecipitation assays revealed that GDD1 bound to the element ACCAACTTGAA in the KO2 promoter. In addition, GDD1 was shown to have transactivation activity. The level of endogenous GAs was reduced in gdd1, and the reorganization of cortical microtubules was altered. Therefore, BC12/GDD1, a kinesin-like protein with transcription regulation activity, mediates cell elongation by regulating the GA biosynthesis pathway in rice. PMID:21325138

  10. Promoter analysis of the Chilo iridescent virus DNA polymerase and major capsid protein genes

    International Nuclear Information System (INIS)

    Nalcacioglu, Remziye; Marks, Hendrik; Vlak, Just M.; Demirbag, Zihni; Oers, Monique M. van

    2003-01-01

    The DNA polymerase (DNApol) and major capsid protein (MCP) genes were used as models to study promoter activity in Chilo iridescent virus (CIV). Infection of Bombyx mori SPC-BM-36 cells in the presence of inhibitors of DNA or protein synthesis showed that DNApol, as well as helicase, is an immediate-early gene and confirmed that the major capsid protein (MCP) is a late gene. Transcription of DNApol initiated 35 nt upstream and that of MCP 14 nt upstream of the translational start site. In a luciferase reporter gene assay both promoters were active only when cells were infected with CIV. For DNApol sequences between position -27 and -6, relative to the transcriptional start site, were essential for promoter activity. Furthermore, mutation of a G within the sequence TTGTTTT located just upstream of the DNApol transcription initiation site reduced the promoter activity by 25%. Sequences crucial for MCP promoter activity are located between positions -53 and -29

  11. Methylation of the ATM promoter in glioma cells alters ionizing radiation sensitivity

    International Nuclear Information System (INIS)

    Roy, Kanaklata; Wang, Lilin; Makrigiorgos, G. Mike; Price, Brendan D.

    2006-01-01

    Glioblastomas are among the malignancies most resistant to radiation therapy. In contrast, cells lacking the ATM protein are highly sensitive to ionizing radiation. The relationship between ATM protein expression and radiosensitivity in 3 glioma cell lines was examined. T98G cells exhibited normal levels of ATM protein, whereas U118 and U87 cells had significantly lower levels of ATM and increased (>2-fold) sensitivity to ionizing radiation compared to T98G cells. The ATM promoter was methylated in U87 cells. Demethylation by azacytidine treatment increased ATM protein levels in the U87 cells and decreased their radiosensitivity. In contrast, the ATM promoter in U118 cells was not methylated. Further, expression of exogenous ATM did not significantly alter the radiosensitivity of U118 cells. ATM expression is therefore heterogeneous in the glioma cells examined. In conclusion, methylation of the ATM promoter may account for the variable radiosensitivity and heterogeneous ATM expression in a fraction of glioma cells

  12. Cell-type specific DNA-protein interactions at the tissue-type plasminogen activator promoter in human endothelial and HeLa cells in vivo and in vitro

    NARCIS (Netherlands)

    Arts, J.; Herr, I.; Lansink, M.; Angel, P.; Kooistra, T.

    1997-01-01

    Tissue-type plasminogen activator (t-PA) gene expression in human endothelial cells and HeLa cells is stimulated by the protein kinase C activator phorbol 12-myristate 13-acetate (PMA) at the level of transcription. To study the mechanism of transcriptional regulation, we have characterized a

  13. Senescence from glioma stem cell differentiation promotes tumor growth

    International Nuclear Information System (INIS)

    Ouchi, Rie; Okabe, Sachiko; Migita, Toshiro; Nakano, Ichiro; Seimiya, Hiroyuki

    2016-01-01

    Glioblastoma (GBM) is a lethal brain tumor composed of heterogeneous cellular populations including glioma stem cells (GSCs) and differentiated non-stem glioma cells (NSGCs). While GSCs are involved in tumor initiation and propagation, NSGCs' role remains elusive. Here, we demonstrate that NSGCs undergo senescence and secrete pro-angiogenic proteins, boosting the GSC-derived tumor formation in vivo. We used a GSC model that maintains stemness in neurospheres, but loses the stemness and differentiates into NSGCs upon serum stimulation. These NSGCs downregulated telomerase, shortened telomeres, and eventually became senescent. The senescent NSGCs released pro-angiogenic proteins, including vascular endothelial growth factors and senescence-associated interleukins, such as IL-6 and IL-8. Conditioned medium from senescent NSGCs promoted proliferation of brain microvascular endothelial cells, and mixed implantation of GSCs and senescent NSGCs into mice enhanced the tumorigenic potential of GSCs. The senescent NSGCs seem to be clinically relevant, because both clinical samples and xenografts of GBM contained tumor cells that expressed the senescence markers. Our data suggest that senescent NSGCs promote malignant progression of GBM in part via paracrine effects of the secreted proteins. - Highlights: • Non-stem glioma cells (NSGCs) lose telomerase and eventually become senescent. • Senescent NSGCs secrete pro-angiogenic proteins, such as VEGFs, IL-6, and IL-8. • Senescent NSGCs enhance the growth of brain microvascular endothelial cells. • Senescent NSGCs enhance the tumorigenic potential of glioma stem cells in vivo.

  14. Senescence from glioma stem cell differentiation promotes tumor growth

    Energy Technology Data Exchange (ETDEWEB)

    Ouchi, Rie [Division of Molecular Biotherapy, Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, 3-8-31 Ariake, Koto-ku, Tokyo 135-8550 (Japan); Laboratory of Molecular Target Therapy of Cancer, Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 3-8-31 Ariake, Koto-ku, Tokyo 135-8550 (Japan); Okabe, Sachiko; Migita, Toshiro [Division of Molecular Biotherapy, Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, 3-8-31 Ariake, Koto-ku, Tokyo 135-8550 (Japan); Nakano, Ichiro [Department of Neurosurgery, Comprehensive Cancer Center, University of Alabama at Birmingham, 1824 6th Avenue South, Birmingham, AL 35233 (United States); Seimiya, Hiroyuki, E-mail: hseimiya@jfcr.or.jp [Division of Molecular Biotherapy, Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, 3-8-31 Ariake, Koto-ku, Tokyo 135-8550 (Japan); Laboratory of Molecular Target Therapy of Cancer, Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 3-8-31 Ariake, Koto-ku, Tokyo 135-8550 (Japan)

    2016-02-05

    Glioblastoma (GBM) is a lethal brain tumor composed of heterogeneous cellular populations including glioma stem cells (GSCs) and differentiated non-stem glioma cells (NSGCs). While GSCs are involved in tumor initiation and propagation, NSGCs' role remains elusive. Here, we demonstrate that NSGCs undergo senescence and secrete pro-angiogenic proteins, boosting the GSC-derived tumor formation in vivo. We used a GSC model that maintains stemness in neurospheres, but loses the stemness and differentiates into NSGCs upon serum stimulation. These NSGCs downregulated telomerase, shortened telomeres, and eventually became senescent. The senescent NSGCs released pro-angiogenic proteins, including vascular endothelial growth factors and senescence-associated interleukins, such as IL-6 and IL-8. Conditioned medium from senescent NSGCs promoted proliferation of brain microvascular endothelial cells, and mixed implantation of GSCs and senescent NSGCs into mice enhanced the tumorigenic potential of GSCs. The senescent NSGCs seem to be clinically relevant, because both clinical samples and xenografts of GBM contained tumor cells that expressed the senescence markers. Our data suggest that senescent NSGCs promote malignant progression of GBM in part via paracrine effects of the secreted proteins. - Highlights: • Non-stem glioma cells (NSGCs) lose telomerase and eventually become senescent. • Senescent NSGCs secrete pro-angiogenic proteins, such as VEGFs, IL-6, and IL-8. • Senescent NSGCs enhance the growth of brain microvascular endothelial cells. • Senescent NSGCs enhance the tumorigenic potential of glioma stem cells in vivo.

  15. Promoter analysis of the Chilo iridescent virus DNA polymerase and major capsid protein genes

    NARCIS (Netherlands)

    Nalcacioglu, R.; Marks, H.; Vlak, J.M.; Demirbag, Z.; Oers, van M.M.

    2003-01-01

    The DNA polymerase (DNApol) and major capsid protein (MCP) genes were used as models to study promoter activity in Chilo iridescent virus (CIV). Infection of Bombyx mori SPC-BM-36 cells in the presence of inhibitors of DNA or protein synthesis showed that DNApol, as well as helicase, is an

  16. Multi-protein delivery by nanodiamonds promotes bone formation.

    Science.gov (United States)

    Moore, L; Gatica, M; Kim, H; Osawa, E; Ho, D

    2013-11-01

    Bone morphogenetic proteins (BMPs) are well-studied regulators of cartilage and bone development that have been Food and Drug Administration (FDA)-approved for the promotion of bone formation in certain procedures. BMPs are seeing more use in oral and maxillofacial surgeries because of recent FDA approval of InFUSE(®) for sinus augmentation and localized alveolar ridge augmentation. However, the utility of BMPs in medical and dental applications is limited by the delivery method. Currently, BMPs are delivered to the surgical site by the implantation of bulky collagen sponges. Here we evaluate the potential of detonation nanodiamonds (NDs) as a delivery vehicle for BMP-2 and basic fibroblast growth factor (bFGF). Nanodiamonds are biocompatible, 4- to 5-nm carbon nanoparticles that have previously been used to deliver a wide variety of molecules, including proteins and peptides. We find that both BMP-2 and bFGF are readily loaded onto NDs by physisorption, forming a stable colloidal solution, and are triggered to release in slightly acidic conditions. Simultaneous delivery of BMP-2 and bFGF by ND induces differentiation and proliferation in osteoblast progenitor cells. Overall, we find that NDs provide an effective injectable alternative for the delivery of BMP-2 and bFGF to promote bone formation.

  17. Prefoldin Promotes Proteasomal Degradation of Cytosolic Proteins with Missense Mutations by Maintaining Substrate Solubility.

    Directory of Open Access Journals (Sweden)

    Sophie A Comyn

    2016-07-01

    Full Text Available Misfolded proteins challenge the ability of cells to maintain protein homeostasis and can accumulate into toxic protein aggregates. As a consequence, cells have adopted a number of protein quality control pathways to prevent protein aggregation, promote protein folding, and target terminally misfolded proteins for degradation. In this study, we employed a thermosensitive allele of the yeast Guk1 guanylate kinase as a model misfolded protein to investigate degradative protein quality control pathways. We performed a flow cytometry based screen to identify factors that promote proteasomal degradation of proteins misfolded as the result of missense mutations. In addition to the E3 ubiquitin ligase Ubr1, we identified the prefoldin chaperone subunit Gim3 as an important quality control factor. Whereas the absence of GIM3 did not impair proteasomal function or the ubiquitination of the model substrate, it led to the accumulation of the poorly soluble model substrate in cellular inclusions that was accompanied by delayed degradation. We found that Gim3 interacted with the Guk1 mutant allele and propose that prefoldin promotes the degradation of the unstable model substrate by maintaining the solubility of the misfolded protein. We also demonstrated that in addition to the Guk1 mutant, prefoldin can stabilize other misfolded cytosolic proteins containing missense mutations.

  18. Sorafenib-induced defective autophagy promotes cell death by necroptosis.

    Science.gov (United States)

    Kharaziha, Pedram; Chioureas, Dimitris; Baltatzis, George; Fonseca, Pedro; Rodriguez, Patricia; Gogvadze, Vladimir; Lennartsson, Lena; Björklund, Ann-Charlotte; Zhivotovsky, Boris; Grandér, Dan; Egevad, Lars; Nilsson, Sten; Panaretakis, Theocharis

    2015-11-10

    Autophagy is one of the main cytoprotective mechanisms that cancer cells deploy to withstand the cytotoxic stress and survive the lethal damage induced by anti-cancer drugs. However, under specific conditions, autophagy may, directly or indirectly, induce cell death. In our study, treatment of the Atg5-deficient DU145 prostate cancer cells, with the multi-tyrosine kinase inhibitor, sorafenib, induces mitochondrial damage, autophagy and cell death. Molecular inhibition of autophagy by silencing ULK1 and Beclin1 rescues DU145 cells from cell death indicating that, in this setting, autophagy promotes cell death. Re-expression of Atg5 restores the lipidation of LC3 and rescues DU145 and MEF atg5-/- cells from sorafenib-induced cell death. Despite the lack of Atg5 expression and LC3 lipidation, DU145 cells form autophagosomes as demonstrated by transmission and immuno-electron microscopy, and the formation of LC3 positive foci. However, the lack of cellular content in the autophagosomes, the accumulation of long-lived proteins, the presence of GFP-RFP-LC3 positive foci and the accumulated p62 protein levels indicate that these autophagosomes may not be fully functional. DU145 cells treated with sorafenib undergo a caspase-independent cell death that is inhibited by the RIPK1 inhibitor, necrostatin-1. Furthermore, treatment with sorafenib induces the interaction of RIPK1 with p62, as demonstrated by immunoprecipitation and a proximity ligation assay. Silencing of p62 decreases the RIPK1 protein levels and renders necrostatin-1 ineffective in blocking sorafenib-induced cell death. In summary, the formation of Atg5-deficient autophagosomes in response to sorafenib promotes the interaction of p62 with RIPK leading to cell death by necroptosis.

  19. TPA-inducible proteins may account for sensitivity to promotion of transformation

    International Nuclear Information System (INIS)

    Hirano, K.; Smith, B.; Colburn, N.H.

    1986-01-01

    The preneoplastic JB6 mouse epidermal cell system includes cell lines sensitive (P + ) or resistant (P - ) to tumor promoter induced neoplastic transformation. The authors investigated whether a difference in TPA-inducible proteins may explain this differential sensitivity. The synthesis of a 39 Kd cytoplasmic protein (Major Excreted Protein) was TPA-inducible, but to a similar extent in both P + and P - cells. TPA stimulated phosphorylation but not synthesis of the previously described stress protein pp80 in both P + and P - cells from 1 to 5 hr after treatment. Pulse labelling of P + and P - cells with 35 S-methionine revealed a TPA dependent P + specific transient increase in the synthesis of 58Kd protein. Induction was observed at 1 hr, and returned to basal levels by 4 hr and 20 hr, in nuclear and cytoplasmic fractions, respectively. This protein is not phosphorylated in response to TPA treatment. P + cells differ from P - cells in one or more genes that specify sensitivity to promotion of transformation, designated pro genes. Antibodies to three peptides representing the pro-1 open reading frame were used in immunoprecipitation and Western blotting to isolate the pro-1 gene product. A 43 Kd protein was immunologically responsive to the pro-1 peptide antibodies, and showed an increased signal 40 min after TPA treatment. Since the predicted molecular weight of a pro-1 gene product is only 7 Kd, the possibility of a modification of the protein by poly(ADP-ribosylation) or glycosylation is being investigated

  20. Probiotics promote endocytic allergen degradation in gut epithelial cells

    International Nuclear Information System (INIS)

    Song, Chun-Hua; Liu, Zhi-Qiang; Huang, Shelly; Zheng, Peng-Yuan; Yang, Ping-Chang

    2012-01-01

    Highlights: ► Knockdown of A20 compromised the epithelial barrier function. ► The fusion of endosome/lysosome was disturbed in the A20-deficient HT-29 cells. ► Antigens transported across A20-deficient HT-29 monolayers conserved antigenicity. ► Probiotic proteins increased the expression of A20 in HT-29 cells. -- Abstract: Background and aims: Epithelial barrier dysfunction plays a critical role in the pathogenesis of allergic diseases; the mechanism is to be further understood. The ubiquitin E3 ligase A20 (A20) plays a role in the endocytic protein degradation in the cells. This study aims to elucidate the role of A20 in the maintenance of gut epithelial barrier function. Methods: Gut epithelial cell line, HT-29 cell, was cultured into monolayers to evaluate the barrier function in transwells. RNA interference was employed to knock down the A20 gene in HT-29 cells to test the role of A20 in the maintenance of epithelial barrier function. Probiotic derived proteins were extracted from the culture supernatants using to enhance the expression of A20 in HT-29 cells. Results: The results showed that the knockdown of A20 compromised the epithelial barrier function in HT-29 monolayers, mainly increased the intracellular permeability. The fusion of endosome/lysosome was disturbed in the A20-deficient HT-29 cells. Allergens collected from the transwell basal chambers of A20-deficient HT-29 monolayers still conserved functional antigenicity. Treating with probiotic derived proteins increased the expression of A20 in HT-29 cells and promote the barrier function. Conclusion: A20 plays an important role in the maintenance of epithelial barrier function as shown by HT-29 monolayer. Probiotic derived protein increases the expression of A20 and promote the HT-29 monolayer barrier function.

  1. Probiotics promote endocytic allergen degradation in gut epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Song, Chun-Hua [Department of Epidemiology and Biostatistics, College of Public Health, Zhengzhou University, Zhengzhou (China); Liu, Zhi-Qiang [Department of Gastroenterology, The Second Hospital, Zhengzhou University, Zhengzhou (China); Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON (Canada); Huang, Shelly [Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON (Canada); Zheng, Peng-Yuan, E-mail: medp7123@126.com [Department of Gastroenterology, The Second Hospital, Zhengzhou University, Zhengzhou (China); Yang, Ping-Chang, E-mail: yangp@mcmaster.ca [Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON (Canada)

    2012-09-14

    Highlights: Black-Right-Pointing-Pointer Knockdown of A20 compromised the epithelial barrier function. Black-Right-Pointing-Pointer The fusion of endosome/lysosome was disturbed in the A20-deficient HT-29 cells. Black-Right-Pointing-Pointer Antigens transported across A20-deficient HT-29 monolayers conserved antigenicity. Black-Right-Pointing-Pointer Probiotic proteins increased the expression of A20 in HT-29 cells. -- Abstract: Background and aims: Epithelial barrier dysfunction plays a critical role in the pathogenesis of allergic diseases; the mechanism is to be further understood. The ubiquitin E3 ligase A20 (A20) plays a role in the endocytic protein degradation in the cells. This study aims to elucidate the role of A20 in the maintenance of gut epithelial barrier function. Methods: Gut epithelial cell line, HT-29 cell, was cultured into monolayers to evaluate the barrier function in transwells. RNA interference was employed to knock down the A20 gene in HT-29 cells to test the role of A20 in the maintenance of epithelial barrier function. Probiotic derived proteins were extracted from the culture supernatants using to enhance the expression of A20 in HT-29 cells. Results: The results showed that the knockdown of A20 compromised the epithelial barrier function in HT-29 monolayers, mainly increased the intracellular permeability. The fusion of endosome/lysosome was disturbed in the A20-deficient HT-29 cells. Allergens collected from the transwell basal chambers of A20-deficient HT-29 monolayers still conserved functional antigenicity. Treating with probiotic derived proteins increased the expression of A20 in HT-29 cells and promote the barrier function. Conclusion: A20 plays an important role in the maintenance of epithelial barrier function as shown by HT-29 monolayer. Probiotic derived protein increases the expression of A20 and promote the HT-29 monolayer barrier function.

  2. Autophagy Stimulus Promotes Early HuR Protein Activation and p62/SQSTM1 Protein Synthesis in ARPE-19 Cells by Triggering Erk1/2, p38MAPK, and JNK Kinase Pathways

    Directory of Open Access Journals (Sweden)

    Nicoletta Marchesi

    2018-01-01

    Full Text Available RNA-binding protein dysregulation and altered expression of proteins involved in the autophagy/proteasome pathway play a role in many neurodegenerative disease onset/progression, including age-related macular degeneration (AMD. HuR/ELAVL1 is a master regulator of gene expression in human physiopathology. In ARPE-19 cells exposed to the proteasomal inhibitor MG132, HuR positively affects at posttranscriptional level p62 expression, a stress response gene involved in protein aggregate clearance with a role in AMD. Here, we studied the early effects of the proautophagy AICAR + MG132 cotreatment on the HuR-p62 pathway. We treated ARPE-19 cells with Erk1/2, AMPK, p38MAPK, PKC, and JNK kinase inhibitors in the presence of AICAR + MG132 and evaluated HuR localization/phosphorylation and p62 expression. Two-hour AICAR + MG132 induces both HuR cytoplasmic translocation and threonine phosphorylation via the Erk1/2 pathway. In these conditions, p62 mRNA is loaded on polysomes and its translation in de novo protein is favored. Additionally, for the first time, we report that JNK can phosphorylate HuR, however, without modulating its localization. Our study supports HuR’s role as an upstream regulator of p62 expression in ARPE-19 cells, helps to understand better the early events in response to a proautophagy stimulus, and suggests that modulation of the autophagy-regulating kinases as potential therapeutic targets for AMD may be relevant.

  3. Mitochondrial fission proteins regulate programmed cell death in yeast

    OpenAIRE

    Fannjiang, Yihru; Cheng, Wen-Chih; Lee, Sarah J.; Qi, Bing; Pevsner, Jonathan; McCaffery, J. Michael; Hill, R. Blake; Basañez, Gorka; Hardwick, J. Marie

    2004-01-01

    The possibility that single-cell organisms undergo programmed cell death has been questioned in part because they lack several key components of the mammalian cell death machinery. However, yeast encode a homolog of human Drp1, a mitochondrial fission protein that was shown previously to promote mammalian cell death and the excessive mitochondrial fragmentation characteristic of apoptotic mammalian cells. In support of a primordial origin of programmed cell death involving mitochondria, we fo...

  4. Prion Protein Promotes Kidney Iron Uptake via Its Ferrireductase Activity*

    Science.gov (United States)

    Haldar, Swati; Tripathi, Ajai; Qian, Juan; Beserra, Amber; Suda, Srinivas; McElwee, Matthew; Turner, Jerrold; Hopfer, Ulrich; Singh, Neena

    2015-01-01

    Brain iron-dyshomeostasis is an important cause of neurotoxicity in prion disorders, a group of neurodegenerative conditions associated with the conversion of prion protein (PrPC) from its normal conformation to an aggregated, PrP-scrapie (PrPSc) isoform. Alteration of iron homeostasis is believed to result from impaired function of PrPC in neuronal iron uptake via its ferrireductase activity. However, unequivocal evidence supporting the ferrireductase activity of PrPC is lacking. Kidney provides a relevant model for this evaluation because PrPC is expressed in the kidney, and ∼370 μg of iron are reabsorbed daily from the glomerular filtrate by kidney proximal tubule cells (PT), requiring ferrireductase activity. Here, we report that PrPC promotes the uptake of transferrin (Tf) and non-Tf-bound iron (NTBI) by the kidney in vivo and mainly NTBI by PT cells in vitro. Thus, uptake of 59Fe administered by gastric gavage, intravenously, or intraperitoneally was significantly lower in PrP-knock-out (PrP−/−) mouse kidney relative to PrP+/+ controls. Selective in vivo radiolabeling of plasma NTBI with 59Fe revealed similar results. Expression of exogenous PrPC in immortalized PT cells showed localization on the plasma membrane and intracellular vesicles and increased transepithelial transport of 59Fe-NTBI and to a smaller extent 59Fe-Tf from the apical to the basolateral domain. Notably, the ferrireductase-deficient mutant of PrP (PrPΔ51–89) lacked this activity. Furthermore, excess NTBI and hemin caused aggregation of PrPC to a detergent-insoluble form, limiting iron uptake. Together, these observations suggest that PrPC promotes retrieval of iron from the glomerular filtrate via its ferrireductase activity and modulates kidney iron metabolism. PMID:25572394

  5. CD1d-restricted IFN-γ-secreting NKT cells promote immune complex-induced acute lung injury by regulating macrophage-inflammatory protein-1α production and activation of macrophages and dendritic cells.

    Science.gov (United States)

    Kim, Ji Hyung; Chung, Doo Hyun

    2011-02-01

    Immune complex-induced acute lung injury (IC-ALI) has been implicated in various pulmonary disease states. However, the role of NKT cells in IC-ALI remains unknown. Therefore, we explored NKT cell functions in IC-ALI using chicken egg albumin and anti-chicken egg albumin IgG. The bronchoalveolar lavage fluid of CD1d(-/-) and Jα18(-/-) mice contained few Ly6G(+)CD11b(+) granulocytes, whereas levels in B6 mice were greater and were increased further by α-galactosyl ceramide. IFN-γ and MIP-1α production in the lungs was greater in B6 than CD1d(-/-) mice. Adoptive transfer of wild type (WT) but not IFN-γ-, MIP-1α-, or FcγR-deficient NKT cells into CD1d(-/-) mice caused recruitment of inflammatory cells to the lungs. Moreover, adoptive transfer of IFN-γR-deficient NKT cells enhanced MIP-1α production and cell recruitment in the lungs of CD1d(-/-) or CD1d(-/-)IFN-γ(-/-) mice, but to a lesser extent than WT NKT cells. This suggests that IFN-γ-producing NKT cells enhance MIP-1α production in both an autocrine and a paracrine manner. IFN-γ-deficient NKT cells induced less IL-1β and TNF-α production by alveolar macrophages and dendritic cells in CD1d(-/-) mice than did WT NKT cells. Taken together, these data suggest that CD1d-restricted IFN-γ-producing NKT cells promote IC-ALI by producing MIP-1α and enhancing proinflammatory cytokine production by alveolar macrophages and dendritic cells.

  6. Hyperglycemia Promotes Schwann Cell De-differentiation and De-myelination via Sorbitol Accumulation and Igf1 Protein Down-regulation.

    Science.gov (United States)

    Hao, Wu; Tashiro, Syoichi; Hasegawa, Tomoka; Sato, Yuiko; Kobayashi, Tami; Tando, Toshimi; Katsuyama, Eri; Fujie, Atsuhiro; Watanabe, Ryuichi; Morita, Mayu; Miyamoto, Kana; Morioka, Hideo; Nakamura, Masaya; Matsumoto, Morio; Amizuka, Norio; Toyama, Yoshiaki; Miyamoto, Takeshi

    2015-07-10

    Diabetes mellitus (DM) is frequently accompanied by complications, such as peripheral nerve neuropathy. Schwann cells play a pivotal role in regulating peripheral nerve function and conduction velocity; however, changes in Schwann cell differentiation status in DM are not fully understood. Here, we report that Schwann cells de-differentiate into immature cells under hyperglycemic conditions as a result of sorbitol accumulation and decreased Igf1 expression in those cells. We found that de-differentiated Schwann cells could be re-differentiated in vitro into mature cells by treatment with an aldose reductase inhibitor, to reduce sorbitol levels, or with vitamin D3, to elevate Igf1 expression. In vivo DM models exhibited significantly reduced nerve function and conduction, Schwann cell de-differentiation, peripheral nerve de-myelination, and all conditions were significantly rescued by aldose reductase inhibitor or vitamin D3 administration. These findings reveal mechanisms underlying pathological changes in Schwann cells seen in DM and suggest ways to treat neurological conditions associated with this condition. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  7. Hyperglycemia Promotes Schwann Cell De-differentiation and De-myelination via Sorbitol Accumulation and Igf1 Protein Down-regulation*

    Science.gov (United States)

    Hao, Wu; Tashiro, Syoichi; Hasegawa, Tomoka; Sato, Yuiko; Kobayashi, Tami; Tando, Toshimi; Katsuyama, Eri; Fujie, Atsuhiro; Watanabe, Ryuichi; Morita, Mayu; Miyamoto, Kana; Morioka, Hideo; Nakamura, Masaya; Matsumoto, Morio; Amizuka, Norio; Toyama, Yoshiaki; Miyamoto, Takeshi

    2015-01-01

    Diabetes mellitus (DM) is frequently accompanied by complications, such as peripheral nerve neuropathy. Schwann cells play a pivotal role in regulating peripheral nerve function and conduction velocity; however, changes in Schwann cell differentiation status in DM are not fully understood. Here, we report that Schwann cells de-differentiate into immature cells under hyperglycemic conditions as a result of sorbitol accumulation and decreased Igf1 expression in those cells. We found that de-differentiated Schwann cells could be re-differentiated in vitro into mature cells by treatment with an aldose reductase inhibitor, to reduce sorbitol levels, or with vitamin D3, to elevate Igf1 expression. In vivo DM models exhibited significantly reduced nerve function and conduction, Schwann cell de-differentiation, peripheral nerve de-myelination, and all conditions were significantly rescued by aldose reductase inhibitor or vitamin D3 administration. These findings reveal mechanisms underlying pathological changes in Schwann cells seen in DM and suggest ways to treat neurological conditions associated with this condition. PMID:25998127

  8. Reprogramming cells with synthetic proteins.

    Science.gov (United States)

    Yang, Xiaoxiao; Malik, Vikas; Jauch, Ralf

    2015-01-01

    Conversion of one cell type into another cell type by forcibly expressing specific cocktails of transcription factors (TFs) has demonstrated that cell fates are not fixed and that cellular differentiation can be a two-way street with many intersections. These experiments also illustrated the sweeping potential of TFs to "read" genetically hardwired regulatory information even in cells where they are not normally expressed and to access and open up tightly packed chromatin to execute gene expression programs. Cellular reprogramming enables the modeling of diseases in a dish, to test the efficacy and toxicity of drugs in patient-derived cells and ultimately, could enable cell-based therapies to cure degenerative diseases. Yet, producing terminally differentiated cells that fully resemble their in vivocounterparts in sufficient quantities is still an unmet clinical need. While efforts are being made to reprogram cells nongenetically by using drug-like molecules, defined TF cocktails still dominate reprogramming protocols. Therefore, the optimization of TFs by protein engineering has emerged as a strategy to enhance reprogramming to produce functional, stable and safe cells for regenerative biomedicine. Engineering approaches focused on Oct4, MyoD, Sox17, Nanog and Mef2c and range from chimeric TFs with added transactivation domains, designer transcription activator-like effectors to activate endogenous TFs to reprogramming TFs with rationally engineered DNA recognition principles. Possibly, applying the complete toolkit of protein design to cellular reprogramming can help to remove the hurdles that, thus far, impeded the clinical use of cells derived from reprogramming technologies.

  9. Eosinophils enhance WNT-5a and TGF-β1 genes expression in airway smooth muscle cells and promote their proliferation by increased extracellular matrix proteins production in asthma.

    Science.gov (United States)

    Januskevicius, Andrius; Vaitkiene, Simona; Gosens, Reinoud; Janulaityte, Ieva; Hoppenot, Deimante; Sakalauskas, Raimundas; Malakauskas, Kestutis

    2016-06-13

    Recent studies have suggested that eosinophils may have a direct effect on airway smooth muscle cells (ASMC), causing their proliferation in patients with asthma, but the precise mechanism of the interaction between these cells remains unknown. We propose that changes in Wnt signaling activity and extracellular matrix (ECM) production may help explain these findings. Therefore, the aim of this study was to investigate the effect of eosinophils from asthmatic and non-asthmatic subjects on Wnt-5a, transforming growth factor β1 (TGF-β1), and ECM protein (fibronectin and collagen) gene expression and ASMC proliferation. A total of 18 subjects were involved in the study: 8 steroid-free asthma patients and 10 healthy subjects. Peripheral blood eosinophils were isolated using centrifugation and magnetic separation. An individual co-culture of eosinophils with human ASMC was prepared for each study subject. Adhesion of eosinophils to ASMC (evaluated by assaying eosinophil peroxidase activity) was determined following various incubation periods (30, 45, 60, 120, and 240 min). The expression of Wnt-5a, TGF-β1, and ECM protein genes in ASMC was measured using quantitative real-time polymerase chain reaction (PCR) after 24 h of co-culture. Proliferation of ASMC was measured using the Alamar blue method after 48 h and 72 h of co-culture with eosinophils. Eosinophils from asthmatic subjects demonstrated increased adhesion to ASMC compared with eosinophils from healthy subjects (p eosinophils from asthmatic subjects, while co-culture of ASMC with eosinophils from healthy subjects increased only TGF-β1 and fibronectin gene expression. ASMC proliferation was augmented after co-culture with eosinophils from asthma patients compared with co-culture with eosinophils from healthy subjects (p Eosinophils enhance Wnt-5a, TGF-β1, fibronectin, and collagen gene expression in ASMC and promote proliferation of these cells in asthma. ClinicalTrials.gov Identifier: NCT02648074 .

  10. Adaptive Evolution Coupled with Retrotransposon Exaptation Allowed for the Generation of a Human-Protein-Specific Coding Gene That Promotes Cancer Cell Proliferation and Metastasis in Both Haematological Malignancies and Solid Tumours: The Extraordinary Case of MYEOV Gene

    Directory of Open Access Journals (Sweden)

    Spyros I. Papamichos

    2015-01-01

    Full Text Available The incidence of cancer in human is high as compared to chimpanzee. However previous analysis has documented that numerous human cancer-related genes are highly conserved in chimpanzee. Till date whether human genome includes species-specific cancer-related genes that could potentially contribute to a higher cancer susceptibility remains obscure. This study focuses on MYEOV, an oncogene encoding for two protein isoforms, reported as causally involved in promoting cancer cell proliferation and metastasis in both haematological malignancies and solid tumours. First we document, via stringent in silico analysis, that MYEOV arose de novo in Catarrhini. We show that MYEOV short-isoform start codon was evolutionarily acquired after Catarrhini/Platyrrhini divergence. Throughout the course of Catarrhini evolution MYEOV acquired a gradually elongated translatable open reading frame (ORF, a gradually shortened translation-regulatory upstream ORF, and alternatively spliced mRNA variants. A point mutation introduced in human allowed for the acquisition of MYEOV long-isoform start codon. Second, we demonstrate the precious impact of exonized transposable elements on the creation of MYEOV gene structure. Third, we highlight that the initial part of MYEOV long-isoform coding DNA sequence was under positive selection pressure during Catarrhini evolution. MYEOV represents a Primate Orphan Gene that acquired, via ORF expansion, a human-protein-specific coding potential.

  11. Marked induction of the helix-loop-helix protein Id3 promotes the gammadelta T cell fate and renders their functional maturation Notch independent

    DEFF Research Database (Denmark)

    Lauritsen, Jens Peter Holst; Wong, Gladys W; Lee, Sang-Yun

    2009-01-01

    )-inhibitor of DNA binding 3 (Id3) pathway plays a defining role in this process. In particular, Id3 expression served to regulate adoption of the gammadelta fate. Moreover, Id3 was both necessary and sufficient to enable gammadelta-lineage cells to differentiate independently of Notch signaling and become competent...

  12. Characterization and functional analyses of the human G protein-coupled receptor kinase 4 gene promoter.

    Science.gov (United States)

    Hasenkamp, Sandra; Telgmann, Ralph; Staessen, Jan A; Hagedorn, Claudia; Dördelmann, Corinna; Bek, Martin; Brand-Herrmann, Stefan-Martin; Brand, Eva

    2008-10-01

    The G protein-coupled receptor kinase 4 is involved in renal sodium handling and blood pressure regulation. Missense variants have already been tested functionally and are associated with hypertension, but no data on promoter analyses are yet available. We scanned 94 hypertensive white subjects for genetic variation and performed promoter reporter gene analyses in HEK293T, COS7, and SaOs-2 cells. Transient transfections with various full lengths and wild-type deletion constructs revealed that 1851 bp of the flanking region and 275 bp of the 5'-untranslated region were sufficient for transcriptional activities and composed a powerful cis-active element in the distal 293 bp. The -1702T and +2T alleles resulted in drastic general reductions of promoter function, whereas an activity increasing effect of +268C was cell type specific. Electrophoretic mobility-shift assay, supershift, and cotransfection analyses of transcription factor binding sites predicted in silico (Alibaba2.1/Transfac7) resulted in allele-specific binding patterns of nuclear proteins and identified the participation of CCAAT/enhancer-binding protein transcription factor family members. The G protein-coupled receptor kinase 4 core promoter resides in the first 1851 bp upstream of its transcription start site. The 4 identified genetic variants within this region exert allele-specific impact on both cell type- and stimulation-dependent transcription and may affect the expression balance of renal G protein-coupled receptor kinase 4.

  13. The inhibition of IGF-1 signaling promotes proteostasis by enhancing protein aggregation and deposition.

    Science.gov (United States)

    Moll, Lorna; Ben-Gedalya, Tziona; Reuveni, Hadas; Cohen, Ehud

    2016-04-01

    The discovery that the alteration of aging by reducing the activity of the insulin/IGF-1 signaling (IIS) cascade protects nematodes and mice from neurodegeneration-linked, toxic protein aggregation (proteotoxicity) raises the prospect that IIS inhibitors bear therapeutic potential to counter neurodegenerative diseases. Recently, we reported that NT219, a highly efficient IGF-1 signaling inhibitor, protects model worms from the aggregation of amyloid β peptide and polyglutamine peptides that are linked to the manifestation of Alzheimer's and Huntington's diseases, respectively. Here, we employed cultured cell systems to investigate whether NT219 promotes protein homeostasis (proteostasis) in mammalian cells and to explore its underlying mechanisms. We found that NT219 enhances the aggregation of misfolded prion protein and promotes its deposition in quality control compartments known as "aggresomes." NT219 also elevates the levels of certain molecular chaperones but, surprisingly, reduces proteasome activity and impairs autophagy. Our findings show that IGF-1 signaling inhibitors in general and NT219 in particular can promote proteostasis in mammalian cells by hyperaggregating hazardous proteins, thereby bearing the potential to postpone the onset and slow the progression of neurodegenerative illnesses in the elderly.-Moll, L., Ben-Gedalya, T., Reuveni, H., Cohen, E. The inhibition of IGF-1 signaling promotes proteostasis by enhancing protein aggregation and deposition. © FASEB.

  14. Human Papillomavirus type 16 E6 and E 7 proteins alter NF-kB in cultured cervical epithelial cells and inhibition of NF-kB promotes cell growth and immortalization

    Science.gov (United States)

    Vandermark, Erik R.; Deluca, Krysta A.; Gardner, Courtney R.; Marker, Daniel F.; Schreiner, Cynthia N.; Strickland, David A.; Wilton, Katelynn M.; Mondal, Sumona; Woodworth, Craig D.

    2012-01-01

    The NF-kB family of transcription factors regulates important biological functions including cell growth, survival and the immune response. We found that Human Papillomavirus type 16 (HPV-16) E7 and E6/E7 proteins inhibited basal and TNF-alpha-inducible NF-kB activity in human epithelial cells cultured from the cervical transformation zone, the anatomic region where most cervical cancers develop. In contrast, HPV-16 E6 regulated NF-kB in a cell type- and cell growth-dependent manner. NF-kB influenced immortalization of cervical cells by HPV16. Inhibition of NF-kB by an IkB alpha repressor mutant increased colony formation and immortalization by HPV-16. In contrast, activation of NF-kB by constitutive expression of p65 inhibited proliferation and immortalization. Our results suggest that inhibition of NF-kB by HPV-16 E6/E7 contributes to immortalization of cells from the cervical transformation zone. PMID:22284893

  15. NSs protein of rift valley fever virus promotes posttranslational downregulation of the TFIIH subunit p62.

    Science.gov (United States)

    Kalveram, Birte; Lihoradova, Olga; Ikegami, Tetsuro

    2011-07-01

    Rift Valley fever virus (RVFV; family Bunyaviridae, genus Phlebovirus) is an important emerging pathogen of humans and ruminants. Its NSs protein has previously been identified as a major virulence factor that suppresses host defense through three distinct mechanisms: it directly inhibits beta interferon (IFN-β) promoter activity, it promotes the degradation of double-stranded RNA-dependent protein kinase (PKR), and it suppresses host transcription by disrupting the assembly of the basal transcription factor TFIIH through sequestration of its p44 subunit. Here, we report that in addition to PKR, NSs also promotes the degradation of the TFIIH subunit p62. Infection of cells with the RVFV MP-12 vaccine strain reduced p62 protein levels to below the detection limit early in the course of infection. This NSs-mediated downregulation of p62 was posttranslational, as it was unaffected by pharmacological inhibition of transcription or translation and MP-12 infection had no effect on p62 mRNA levels. Treatment of cells with proteasome inhibitors but not inhibition of lysosomal acidification or nuclear export resulted in a stabilization of p62 in the presence of NSs. Furthermore, p62 could be coprecipitated with NSs from lysates of infected cells. These data suggest that the RVFV NSs protein is able to interact with the TFIIH subunit p62 inside infected cells and promotes its degradation, which can occur directly in the nucleus.

  16. Ubiquitin-like protein UBL5 promotes the functional integrity of the Fanconi anemia pathway

    DEFF Research Database (Denmark)

    Oka, Yasuyoshi; Bekker-Jensen, Simon; Mailand, Niels

    2015-01-01

    in promoting the function of the Fanconi anemia (FA) pathway for repair of DNA interstrand crosslinks (ICLs), mediated by a specific interaction with the central FA pathway component FANCI. UBL5-deficient cells display spliceosome-independent reduction of FANCI protein stability, defective FANCI function...

  17. VP1, the major capsid protein of the mouse polyomavirus, binds microtubules, promotes their acetylation and blocks the host cell cycle

    Czech Academy of Sciences Publication Activity Database

    Horníková, L.; Fraiberk, M.; Man, Petr; Janovec, V.; Forstová, J.

    2017-01-01

    Roč. 284, č. 2 (2017), s. 301-323 E-ISSN 1742-4658 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0109; GA MŠk(CZ) LO1509 Grant - others:Ministerstvo pro místní rozvoj(CZ) CZ.2.16./3.1.00/24023 Institutional support: RVO:61388971 Keywords : cell cycle arrest * chaperone Hsp90 * microtubules Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology

  18. Targeted taste cell-specific overexpression of brain-derived neurotrophic factor in adult taste buds elevates phosphorylated TrkB protein levels in taste cells, increases taste bud size, and promotes gustatory innervation.

    Science.gov (United States)

    Nosrat, Irina V; Margolskee, Robert F; Nosrat, Christopher A

    2012-05-11

    Brain-derived neurotrophic factor (BDNF) is the most potent neurotrophic factor in the peripheral taste system during embryonic development. It is also expressed in adult taste buds. There is a lack of understanding of the role of BDNF in the adult taste system. To address this, we generated novel transgenic mice in which transgene expression was driven by an α-gustducin promoter coupling BDNF expression to the postnatal expression of gustducin in taste cells. Immunohistochemistry revealed significantly stronger BDNF labeling in taste cells of high BDNF-expressing mouse lines compared with controls. We show that taste buds in these mice are significantly larger and have a larger number of taste cells compared with controls. To examine whether innervation was affected in Gust-BDNF mice, we used antibodies to neural cell adhesion molecule (NCAM) and ATP receptor P2X3. The total density of general innervation and specifically the gustatory innervation was markedly increased in high BDNF-expressing mice compared with controls. TrkB and NCAM gene expression in laser capture microdissected taste epithelia were significantly up-regulated in these mice. Up-regulation of TrkB transcripts in taste buds and elevated taste cell-specific TrkB phosphorylation in response to increased BDNF levels indicate that BDNF controls the expression and activation of its high affinity receptor in taste cells. This demonstrates a direct taste cell function for BDNF. BDNF also orchestrates and maintains taste bud innervation. We propose that the Gust-BDNF transgenic mouse models can be employed to further dissect the specific roles of BDNF in the adult taste system.

  19. Targeted Taste Cell-specific Overexpression of Brain-derived Neurotrophic Factor in Adult Taste Buds Elevates Phosphorylated TrkB Protein Levels in Taste Cells, Increases Taste Bud Size, and Promotes Gustatory Innervation*

    Science.gov (United States)

    Nosrat, Irina V.; Margolskee, Robert F.; Nosrat, Christopher A.

    2012-01-01

    Brain-derived neurotrophic factor (BDNF) is the most potent neurotrophic factor in the peripheral taste system during embryonic development. It is also expressed in adult taste buds. There is a lack of understanding of the role of BDNF in the adult taste system. To address this, we generated novel transgenic mice in which transgene expression was driven by an α-gustducin promoter coupling BDNF expression to the postnatal expression of gustducin in taste cells. Immunohistochemistry revealed significantly stronger BDNF labeling in taste cells of high BDNF-expressing mouse lines compared with controls. We show that taste buds in these mice are significantly larger and have a larger number of taste cells compared with controls. To examine whether innervation was affected in Gust-BDNF mice, we used antibodies to neural cell adhesion molecule (NCAM) and ATP receptor P2X3. The total density of general innervation and specifically the gustatory innervation was markedly increased in high BDNF-expressing mice compared with controls. TrkB and NCAM gene expression in laser capture microdissected taste epithelia were significantly up-regulated in these mice. Up-regulation of TrkB transcripts in taste buds and elevated taste cell-specific TrkB phosphorylation in response to increased BDNF levels indicate that BDNF controls the expression and activation of its high affinity receptor in taste cells. This demonstrates a direct taste cell function for BDNF. BDNF also orchestrates and maintains taste bud innervation. We propose that the Gust-BDNF transgenic mouse models can be employed to further dissect the specific roles of BDNF in the adult taste system. PMID:22442142

  20. Identification of a novel temperature sensitive promoter in cho cells

    Directory of Open Access Journals (Sweden)

    Hesse Friedemann

    2011-05-01

    Full Text Available Abstract Background The Chinese hamster ovary (CHO expression system is the leading production platform for manufacturing biopharmaceuticals for the treatment of numerous human diseases. Efforts to optimize the production process also include the genetic construct encoding the therapeutic gene. Here we report about the successful identification of an endogenous highly active gene promoter obtained from CHO cells which shows conditionally inducible gene expression at reduced temperature. Results Based on CHO microarray expression data abundantly transcribed genes were selected as potential promoter candidates. The S100a6 (calcyclin and its flanking regions were identified from a genomic CHO-K1 lambda-phage library. Computational analyses showed a predicted TSS, a TATA-box and several TFBSs within the 1.5 kb region upstream the ATG start signal. Various constructs were investigated for promoter activity at 37°C and 33°C in transient luciferase reporter gene assays. Most constructs showed expression levels even higher than the SV40 control and on average a more than two-fold increase at lower temperature. We identified the core promoter sequence (222 bp comprising two SP1 sites and could show a further increase in activity by duplication of this minimal sequence. Conclusions This novel CHO promoter permits conditionally high-level gene expression. Upon a shift to 33°C, a two to three-fold increase of basal productivity (already higher than SV40 promoter is achieved. This property is of particular advantage for a process with reduced expression during initial cell growth followed by the production phase at low temperature with a boost in expression. Additionally, production of toxic proteins becomes feasible, since cell metabolism and gene expression do not directly interfere. The CHO S100a6 promoter can be characterized as cold-shock responsive with the potential for improving process performance of mammalian expression systems.

  1. TALE factors poise promoters for activation by Hox proteins.

    Science.gov (United States)

    Choe, Seong-Kyu; Ladam, Franck; Sagerström, Charles G

    2014-01-27

    Hox proteins form complexes with TALE cofactors from the Pbx and Prep/Meis families to control transcription, but it remains unclear how Hox:TALE complexes function. Examining a Hoxb1b:TALE complex that regulates zebrafish hoxb1a transcription, we find maternally deposited TALE proteins at the hoxb1a promoter already during blastula stages. These TALE factors recruit histone-modifying enzymes to promote an active chromatin profile at the hoxb1a promoter and also recruit RNA polymerase II (RNAPII) and P-TEFb. However, in the presence of TALE factors, RNAPII remains phosphorylated on serine 5 and hoxb1a transcription is inefficient. By gastrula stages, Hoxb1b binds together with TALE factors to the hoxb1a promoter. This triggers P-TEFb-mediated transitioning of RNAPII to the serine 2-phosphorylated form and efficient hoxb1a transcription. We conclude that TALE factors access promoters during early embryogenesis to poise them for activation but that Hox proteins are required to trigger efficient transcription. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Ligand-promoted protein folding by biased kinetic partitioning.

    Science.gov (United States)

    Hingorani, Karan S; Metcalf, Matthew C; Deming, Derrick T; Garman, Scott C; Powers, Evan T; Gierasch, Lila M

    2017-04-01

    Protein folding in cells occurs in the presence of high concentrations of endogenous binding partners, and exogenous binding partners have been exploited as pharmacological chaperones. A combined mathematical modeling and experimental approach shows that a ligand improves the folding of a destabilized protein by biasing the kinetic partitioning between folding and alternative fates (aggregation or degradation). Computationally predicted inhibition of test protein aggregation and degradation as a function of ligand concentration are validated by experiments in two disparate cellular systems.

  3. Reprogramming cells with synthetic proteins

    Directory of Open Access Journals (Sweden)

    Xiaoxiao Yang

    2015-06-01

    Full Text Available Conversion of one cell type into another cell type by forcibly expressing specific cocktails of transcription factors (TFs has demonstrated that cell fates are not fixed and that cellular differentiation can be a two-way street with many intersections. These experiments also illustrated the sweeping potential of TFs to "read" genetically hardwired regulatory information even in cells where they are not normally expressed and to access and open up tightly packed chromatin to execute gene expression programs. Cellular reprogramming enables the modeling of diseases in a dish, to test the efficacy and toxicity of drugs in patient-derived cells and ultimately, could enable cell-based therapies to cure degenerative diseases. Yet, producing terminally differentiated cells that fully resemble their in vivocounterparts in sufficient quantities is still an unmet clinical need. While efforts are being made to reprogram cells nongenetically by using drug-like molecules, defined TF cocktails still dominate reprogramming protocols. Therefore, the optimization of TFs by protein engineering has emerged as a strategy to enhance reprogramming to produce functional, stable and safe cells for regenerative biomedicine. Engineering approaches focused on Oct4, MyoD, Sox17, Nanog and Mef2c and range from chimeric TFs with added transactivation domains, designer transcription activator-like effectors to activate endogenous TFs to reprogramming TFs with rationally engineered DNA recognition principles. Possibly, applying the complete toolkit of protein design to cellular reprogramming can help to remove the hurdles that, thus far, impeded the clinical use of cells derived from reprogramming technologies.

  4. Reprogramming cells with synthetic proteins

    Science.gov (United States)

    Yang, Xiaoxiao; Malik, Vikas; Jauch, Ralf

    2015-01-01

    Conversion of one cell type into another cell type by forcibly expressing specific cocktails of transcription factors (TFs) has demonstrated that cell fates are not fixed and that cellular differentiation can be a two-way street with many intersections. These experiments also illustrated the sweeping potential of TFs to “read” genetically hardwired regulatory information even in cells where they are not normally expressed and to access and open up tightly packed chromatin to execute gene expression programs. Cellular reprogramming enables the modeling of diseases in a dish, to test the efficacy and toxicity of drugs in patient-derived cells and ultimately, could enable cell-based therapies to cure degenerative diseases. Yet, producing terminally differentiated cells that fully resemble their in vivo counterparts in sufficient quantities is still an unmet clinical need. While efforts are being made to reprogram cells nongenetically by using drug-like molecules, defined TF cocktails still dominate reprogramming protocols. Therefore, the optimization of TFs by protein engineering has emerged as a strategy to enhance reprogramming to produce functional, stable and safe cells for regenerative biomedicine. Engineering approaches focused on Oct4, MyoD, Sox17, Nanog and Mef2c and range from chimeric TFs with added transactivation domains, designer transcription activator-like effectors to activate endogenous TFs to reprogramming TFs with rationally engineered DNA recognition principles. Possibly, applying the complete toolkit of protein design to cellular reprogramming can help to remove the hurdles that, thus far, impeded the clinical use of cells derived from reprogramming technologies. PMID:25652623

  5. IGFBP1 increases β-cell regeneration by promoting α- to β-cell transdifferentiation.

    Science.gov (United States)

    Lu, Jing; Liu, Ka-Cheuk; Schulz, Nadja; Karampelias, Christos; Charbord, Jérémie; Hilding, Agneta; Rautio, Linn; Bertolino, Philippe; Östenson, Claes-Göran; Brismar, Kerstin; Andersson, Olov

    2016-09-15

    There is great interest in therapeutically harnessing endogenous regenerative mechanisms to increase the number of β cells in people with diabetes. By performing whole-genome expression profiling of zebrafish islets, we identified 11 secreted proteins that are upregulated during β-cell regeneration. We then tested the proteins' ability to potentiate β-cell regeneration in zebrafish at supraphysiological levels. One protein, insulin-like growth factor (Igf) binding-protein 1 (Igfbp1), potently promoted β-cell regeneration by potentiating α- to β-cell transdifferentiation. Using various inhibitors and activators of the Igf pathway, we show that Igfbp1 exerts its regenerative effect, at least partly, by inhibiting Igf signaling. Igfbp1's effect on transdifferentiation appears conserved across species: Treating mouse and human islets with recombinant IGFBP1 in vitro increased the number of cells co-expressing insulin and glucagon threefold. Moreover, a prospective human study showed that having high IGFBP1 levels reduces the risk of developing type-2 diabetes by more than 85%. Thus, we identify IGFBP1 as an endogenous promoter of β-cell regeneration and highlight its clinical importance in diabetes. © 2016 The Authors. Published under the terms of the CC BY NC ND 4.0 license.

  6. Fascin overexpression promotes neoplastic progression in oral squamous cell carcinoma

    Directory of Open Access Journals (Sweden)

    Alam Hunain

    2012-01-01

    Full Text Available Abstract Background Fascin is a globular actin cross-linking protein, which plays a major role in forming parallel actin bundles in cell protrusions and is found to be associated with tumor cell invasion and metastasis in various type of cancers including oral squamous cell carcinoma (OSCC. Previously, we have demonstrated that fascin regulates actin polymerization and thereby promotes cell motility in K8-depleted OSCC cells. In the present study we have investigated the role of fascin in tumor progression of OSCC. Methods To understand the role of fascin in OSCC development and/or progression, fascin was overexpressed along with vector control in OSCC derived cells AW13516. The phenotype was studied using wound healing, Boyden chamber, cell adhesion, Hanging drop, soft agar and tumorigenicity assays. Further, fascin expression was examined in human OSCC samples (N = 131 using immunohistochemistry and level of its expression was correlated with clinico-pathological parameters of the patients. Results Fascin overexpression in OSCC derived cells led to significant increase in cell migration, cell invasion and MMP-2 activity. In addition these cells demonstrated increased levels of phosphorylated AKT, ERK1/2 and JNK1/2. Our in vitro results were consistent with correlative studies of fascin expression with the clinico-pathological parameters of the OSCC patients. Fascin expression in OSCC showed statistically significant correlation with increased tumor stage (P = 0.041, increased lymph node metastasis (P = 0.001, less differentiation (P = 0.005, increased recurrence (P = 0.038 and shorter survival (P = 0.004 of the patients. Conclusion In conclusion, our results indicate that fascin promotes tumor progression and activates AKT and MAPK pathways in OSCC-derived cells. Further, our correlative studies of fascin expression in OSCC with clinico-pathological parameters of the patients indicate that fascin may prove to be useful in prognostication and

  7. Fascin overexpression promotes neoplastic progression in oral squamous cell carcinoma

    International Nuclear Information System (INIS)

    Alam, Hunain; Kannanl, Sadhna; Gude, Rajiv; Kane, Shubhada; Dalal, Sorab N; Vaidya, Milind M; Bhate, Amruta V; Gangadaran, Prakash; Sawant, Sharda S; Salot, Shimul; Sehgal, Lalit; Dange, Prerana P; Chaukar, Devendra A; D'cruz, Anil K

    2012-01-01

    Fascin is a globular actin cross-linking protein, which plays a major role in forming parallel actin bundles in cell protrusions and is found to be associated with tumor cell invasion and metastasis in various type of cancers including oral squamous cell carcinoma (OSCC). Previously, we have demonstrated that fascin regulates actin polymerization and thereby promotes cell motility in K8-depleted OSCC cells. In the present study we have investigated the role of fascin in tumor progression of OSCC. To understand the role of fascin in OSCC development and/or progression, fascin was overexpressed along with vector control in OSCC derived cells AW13516. The phenotype was studied using wound healing, Boyden chamber, cell adhesion, Hanging drop, soft agar and tumorigenicity assays. Further, fascin expression was examined in human OSCC samples (N = 131) using immunohistochemistry and level of its expression was correlated with clinico-pathological parameters of the patients. Fascin overexpression in OSCC derived cells led to significant increase in cell migration, cell invasion and MMP-2 activity. In addition these cells demonstrated increased levels of phosphorylated AKT, ERK1/2 and JNK1/2. Our in vitro results were consistent with correlative studies of fascin expression with the clinico-pathological parameters of the OSCC patients. Fascin expression in OSCC showed statistically significant correlation with increased tumor stage (P = 0.041), increased lymph node metastasis (P = 0.001), less differentiation (P = 0.005), increased recurrence (P = 0.038) and shorter survival (P = 0.004) of the patients. In conclusion, our results indicate that fascin promotes tumor progression and activates AKT and MAPK pathways in OSCC-derived cells. Further, our correlative studies of fascin expression in OSCC with clinico-pathological parameters of the patients indicate that fascin may prove to be useful in prognostication and treatment of OSCC

  8. A Dominant-Negative PPARγ Mutant Promotes Cell Cycle Progression and Cell Growth in Vascular Smooth Muscle Cells

    Directory of Open Access Journals (Sweden)

    Joey Z. Liu

    2009-01-01

    Full Text Available PPARγ ligands have been shown to have antiproliferative effects on many cell types. We herein report that a synthetic dominant-negative (DN PPARγ mutant functions like a growth factor to promote cell cycle progression and cell proliferation in human coronary artery smooth muscle cells (CASMCs. In quiescent CASMCs, adenovirus-expressed DN-PPARγ promoted G1→S cell cycle progression, enhanced BrdU incorporation, and increased cell proliferation. DN-PPARγ expression also markedly enhanced positive regulators of the cell cycle, increasing Rb and CDC2 phosphorylation and the expression of cyclin A, B1, D1, and MCM7. Conversely, overexpression of wild-type (WT or constitutively-active (CA PPARγ inhibited cell cycle progression and the activity and expression of positive regulators of the cell cycle. DN-PPARγ expression, however, did not up-regulate positive cell cycle regulators in PPARγ-deficient cells, strongly suggesting that DN-PPARγ effects on cell cycle result from blocking the function of endogenous wild-type PPARγ. DN-PPARγ expression enhanced phosphorylation of ERK MAPKs. Furthermore, the ERK specific-inhibitor PD98059 blocked DN-PPARγ-induced phosphorylation of Rb and expression of cyclin A and MCM7. Our data thus suggest that DN-PPARγ promotes cell cycle progression and cell growth in CASMCs by modulating fundamental cell cycle regulatory proteins and MAPK mitogenic signaling pathways in vascular smooth muscle cells (VSMCs.

  9. Sublethal irradiation promotes invasiveness of neuroblastoma cells

    International Nuclear Information System (INIS)

    Schweigerer, Lothar; Rave-Fraenk, Margret; Schmidberger, Heinz; Hecht, Monica

    2005-01-01

    Neuroblastoma is the most frequent extracranial solid tumour of childhood. Despite multiple clinical efforts, clinical outcome has remained poor. Neuroblastoma is considered to be radiosensitive, but some clinical studies including the German trial NB90 failed to show a clinical benefit of radiation therapy. The mechanisms underlying this apparent discrepancy are still unclear. We have therefore investigated the effects of radiation on neuroblastoma cell behaviour in vitro. We show that sublethal doses of irradiation up-regulated the expression of the hepatocyte growth factor (HGF) and its receptor c-Met in some neuroblastoma cell lines. The increase in HGF/c-Met expression was correlated with enhanced invasiveness and activation of proteases degrading the extracellular matrix. Thus, irradiation at sublethal doses may promote the metastatic dissemination of neuroblastoma cells through activating the HGF/c-Met pathway and triggering matrix degradation

  10. Rac1 acts in conjunction with Nedd4 and dishevelled-1 to promote maturation of cell-cell contacts

    NARCIS (Netherlands)

    M. Nethe (Micha); B.J. de Kreuk (Bart-Jan); D.V.F. Tauriello (Daniele); E.C. Anthony (Eloise); B. Snoek (Barbara); T. Stumpel (Thomas); M. Salinas; K. Maurice (Karelle); D. Geerts (Dirk); A.M. Deelder (André); P. Hensbergen (Paul); P.L. Hordijk (Peter )

    2012-01-01

    textabstractThe Rho-GTPase Rac1 promotes actin polymerization and membrane protrusion that mediate initial contact and subsequent maturation of cell-cell junctions. Here we report that Rac1 associates with the ubiquitin-protein ligase neural precursor cell expressed developmentally down-regulated 4

  11. Functional analysis of bipartite begomovirus coat protein promoter sequences

    International Nuclear Information System (INIS)

    Lacatus, Gabriela; Sunter, Garry

    2008-01-01

    We demonstrate that the AL2 gene of Cabbage leaf curl virus (CaLCuV) activates the CP promoter in mesophyll and acts to derepress the promoter in vascular tissue, similar to that observed for Tomato golden mosaic virus (TGMV). Binding studies indicate that sequences mediating repression and activation of the TGMV and CaLCuV CP promoter specifically bind different nuclear factors common to Nicotiana benthamiana, spinach and tomato. However, chromatin immunoprecipitation demonstrates that TGMV AL2 can interact with both sequences independently. Binding of nuclear protein(s) from different crop species to viral sequences conserved in both bipartite and monopartite begomoviruses, including TGMV, CaLCuV, Pepper golden mosaic virus and Tomato yellow leaf curl virus suggests that bipartite begomoviruses bind common host factors to regulate the CP promoter. This is consistent with a model in which AL2 interacts with different components of the cellular transcription machinery that bind viral sequences important for repression and activation of begomovirus CP promoters

  12. Protein tyrosine nitration in the cell cycle

    International Nuclear Information System (INIS)

    Jia, Min; Mateoiu, Claudia; Souchelnytskyi, Serhiy

    2011-01-01

    Highlights: → Enrichment of 3-nitrotyrosine containing proteins from cells synchronized in different phases of the cell cycle. → Identification of 76 tyrosine nitrated proteins that change expression during the cell cycle. → Nineteen identified proteins were previously described as regulators of cell proliferation. -- Abstract: Nitration of tyrosine residues in proteins is associated with cell response to oxidative/nitrosative stress. Tyrosine nitration is relatively low abundant post-translational modification that may affect protein functions. Little is known about the extent of protein tyrosine nitration in cells during progression through the cell cycle. Here we report identification of proteins enriched for tyrosine nitration in cells synchronized in G0/G1, S or G2/M phases of the cell cycle. We identified 27 proteins in cells synchronized in G0/G1 phase, 37 proteins in S phase synchronized cells, and 12 proteins related to G2/M phase. Nineteen of the identified proteins were previously described as regulators of cell proliferation. Thus, our data indicate which tyrosine nitrated proteins may affect regulation of the cell cycle.

  13. Polycomb complex protein BMI-1 promotes invasion and metastasis of pancreatic cancer stem cells by activating PI3K/AKT signaling, an ex vivo, in vitro, and in vivo study

    Science.gov (United States)

    Wang, Min-Cong; Jiao, Min; Wu, Tao; Jing, Li; Cui, Jie; Guo, Hui; Tian, Tao; Ruan, Zhi-ping; Wei, Yong-Chang; Jiang, Li-Li; Sun, Hai-Feng; Huang, Lan-Xuan; Nan, Ke-Jun; Li, Chun-Li

    2016-01-01

    Cancer stem cell theory indicates cancer stem cells are the key to promote tumor invasion and metastasis. Studies showed that BMI-1 could promote self-renew, differentiation and tumor formation of CSCs and invasion/metastasis of human cancer. However, whether BMI-1 could regulate invasion and metastasis ability of CSCs is still unclear. In our study, we found that up-regulated expression of BMI-1 was associated with tumor invasion, metastasis and poor survival of pancreatic cancer patients. CD133+ cells were obtained by using magnetic cell sorting and identified of CSCs properties such as self-renew, multi-differentiation and tumor formation ability. Then, we found that BMI-1 expression was up-regulated in pancreatic cancer stem cells. Knockdown of BMI-1 expression attenuated invasion ability of pancreatic cancer stem cells in Transwell system and liver metastasis capacity in nude mice which were injected CSCs through the caudal vein. We are the first to reveal that BMI-1 could promote invasion and metastasis ability of pancreatic cancer stem cells. Finally, we identified that BMI-1 expression activating PI3K/AKT singing pathway by negative regulating PTEN was the main mechanism of promoting invasion and metastasis ability of pancreatic CSCs. In summary, our findings indicate that BMI-1 could be used as the therapeutic target to inhibiting CSCs-mediated pancreatic cancer metastasis. PMID:26840020

  14. Cortactin Tyrosine Phosphorylation Promotes Its Deacetylation and Inhibits Cell Spreading

    Science.gov (United States)

    Meiler, Eugenia; Nieto-Pelegrín, Elvira; Martinez-Quiles, Narcisa

    2012-01-01

    Background Cortactin is a classical Src kinase substrate that participates in actin cytoskeletal dynamics by activating the Arp2/3 complex and interacting with other regulatory proteins, including FAK. Cortactin has various domains that may contribute to the assembly of different protein platforms to achieve process specificity. Though the protein is known to be regulated by post-translational modifications such as phosphorylation and acetylation, how tyrosine phosphorylation regulates cortactin activity is poorly understood. Since the basal level of tyrosine phosphorylation is low, this question must be studied using stimulated cell cultures, which are physiologically relevant but unreliable and difficult to work with. In fact, their unreliability may be the cause of some contradictory findings about the dynamics of tyrosine phosphorylation of cortactin in different processes. Methodology/Principal Findings In the present study, we try to overcome these problems by using a Functional Interaction Trap (FIT) system, which involves cotransfecting cells with a kinase (Src) and a target protein (cortactin), both of which are fused to complementary leucine-zipper domains. The FIT system allowed us to control precisely the tyrosine phosphorylation of cortactin and explore its relationship with cortactin acetylation. Conclusions/Significance Using this system, we provide definitive evidence that a competition exists between acetylation and tyrosine phosphorylation of cortactin and that phosphorylation inhibits cell spreading. We confirmed the results from the FIT system by examining endogenous cortactin in different cell types. Furthermore, we demonstrate that cell spreading promotes the association of cortactin and FAK and that tyrosine phosphorylation of cortactin disrupts this interaction, which may explain how it inhibits cell spreading. PMID:22479425

  15. The synergistic transactivation of the hepatitis B viral (HBV) pregenomic promoter by the E6 protein of human papillomavirus type 16 (HPV-16 E6) with HBV X protein was mediated through the AP1 site of E element in the enhancer I (EnI) in human liver cell.

    Science.gov (United States)

    Lee, D H; Choi, B H; Rho, H M

    1999-11-01

    Infection by HBV of a cell already infected with other viral species or vice versa has been suggested as being involved in hepatocellular carcinoma. Using the CAT assay method, we investigated the interactive roles of HBx and potentially oncogenic and transactivating viral early proteins such as Ad5 E1A, HPV-16 E6, and SV40 T ag. In the presence of HBx, only HPV-16 E6 showed significant synergistic transactivation of EnI. We further investigated the function of the HPV-16 E6 using deletion, heterologous promoter, and mutation analyses on the EnI promoter. The results showed that the synergistic effect was mediated through the AP1 site of the E element in EnI by the direct activation of AP1 and support the idea that the infection by HBV of the cell with other viral species such as HPV-16 could increase the transcription activity of the HBV and other oncogenes containing an AP1 site in the promoter. Copyright 1999 Academic Press.

  16. A novel splice variant of supervillin, SV5, promotes carcinoma cell proliferation and cell migration

    International Nuclear Information System (INIS)

    Chen, Xueran; Yang, Haoran; Zhang, Shangrong; Wang, Zhen; Ye, Fang; Liang, Chaozhao; Wang, Hongzhi; Fang, Zhiyou

    2017-01-01

    Supervillin is an actin-associated protein that regulates actin dynamics by interacting with Myosin II, F-actin, and Cortactin to promote cell contractility and cell motility. Two splicing variants of human Supervillin (SV1 and SV4) have been reported in non-muscle cells; SV1 lacks 3 exons present in the larger isoform SV4. SV2, also called archvillin, is present in striated muscle; SV3, also called smooth muscle archvillin or SmAV, was cloned from smooth muscle. In the present study, we identify a novel splicing variant of Supervillin (SV5). SV5 contains a new splicing pattern. In the mouse tissues and cell lines examined, SV5 was predominantly expressed in skeletal and cardiac muscles and in proliferating cells, but was virtually undetectable in most normal tissues. Using RNAi and rescue experiments, we show here that SV5 displays altered functional properties in cancer cells, and regulates cell proliferation and cell migration.

  17. Mitochondrial fission proteins regulate programmed cell death in yeast.

    Science.gov (United States)

    Fannjiang, Yihru; Cheng, Wen-Chih; Lee, Sarah J; Qi, Bing; Pevsner, Jonathan; McCaffery, J Michael; Hill, R Blake; Basañez, Gorka; Hardwick, J Marie

    2004-11-15

    The possibility that single-cell organisms undergo programmed cell death has been questioned in part because they lack several key components of the mammalian cell death machinery. However, yeast encode a homolog of human Drp1, a mitochondrial fission protein that was shown previously to promote mammalian cell death and the excessive mitochondrial fragmentation characteristic of apoptotic mammalian cells. In support of a primordial origin of programmed cell death involving mitochondria, we found that the Saccharomyces cerevisiae homolog of human Drp1, Dnm1, promotes mitochondrial fragmentation/degradation and cell death following treatment with several death stimuli. Two Dnm1-interacting factors also regulate yeast cell death. The WD40 repeat protein Mdv1/Net2 promotes cell death, consistent with its role in mitochondrial fission. In contrast to its fission function in healthy cells, Fis1 unexpectedly inhibits Dnm1-mediated mitochondrial fission and cysteine protease-dependent cell death in yeast. Furthermore, the ability of yeast Fis1 to inhibit mitochondrial fission and cell death can be functionally replaced by human Bcl-2 and Bcl-xL. Together, these findings indicate that yeast and mammalian cells have a conserved programmed death pathway regulated by a common molecular component, Drp1/Dnm1, that is inhibited by a Bcl-2-like function.

  18. Palmitoylation at Cys574 is essential for MT1-MMP to promote cell migration

    DEFF Research Database (Denmark)

    Anilkumar, Narayanapanicker; Uekita, Takamasa; Couchman, John R

    2005-01-01

    of the palmitoylated cysteine relative to LLY573, a motif that interacts with mu2 subunit of adaptor protein 2, is critical for the cell motility-promoting activity of MT1-MMP and its clathrin-mediated internalization. Taken together, palmitoylation of MT1-MMP is one of the key posttranslational modifications......MT1-MMP is a type I transmembrane proteinase that promotes cell migration and invasion. Here, we report that MT1-MMP is palmitoylated at Cys574 in the cytoplasmic domain, and this lipid modification is critical for its promotion of cell migration and clathrin-mediated internalization...... that determines MT1-MMP-dependent cell migration....

  19. Promotion of bone morphogenetic protein signaling by tetraspanins and glycosphingolipids.

    Directory of Open Access Journals (Sweden)

    Zhiyu Liu

    2015-05-01

    Full Text Available Bone morphogenetic proteins (BMPs belong to the transforming growth factor β (TGFβ superfamily of secreted molecules. BMPs play essential roles in multiple developmental and homeostatic processes in metazoans. Malfunction of the BMP pathway can cause a variety of diseases in humans, including cancer, skeletal disorders and cardiovascular diseases. Identification of factors that ensure proper spatiotemporal control of BMP signaling is critical for understanding how this pathway is regulated. We have used a unique and sensitive genetic screen to identify the plasma membrane-localized tetraspanin TSP-21 as a key new factor in the C. elegans BMP-like "Sma/Mab" signaling pathway that controls body size and postembryonic M lineage development. We showed that TSP-21 acts in the signal-receiving cells and genetically functions at the ligand-receptor level. We further showed that TSP-21 can associate with itself and with two additional tetraspanins, TSP-12 and TSP-14, which also promote Sma/Mab signaling. TSP-12 and TSP-14 can also associate with SMA-6, the type I receptor of the Sma/Mab pathway. Finally, we found that glycosphingolipids, major components of the tetraspanin-enriched microdomains, are required for Sma/Mab signaling. Our findings suggest that the tetraspanin-enriched membrane microdomains are important for proper BMP signaling. As tetraspanins have emerged as diagnostic and prognostic markers for tumor progression, and TSP-21, TSP-12 and TSP-14 are all conserved in humans, we speculate that abnormal BMP signaling due to altered expression or function of certain tetraspanins may be a contributing factor to cancer development.

  20. Translationally controlled tumor protein supplemented chitosan modified glass ionomer cement promotes osteoblast proliferation and function

    International Nuclear Information System (INIS)

    Sangsuwan, Jiraporn; Wanichpakorn, Supreya; Kedjarune-Leggat, Ureporn

    2015-01-01

    The objective of this study was to evaluate the effect of translationally controlled tumor protein (TCTP) supplemented in a novel glass ionomer cement (BIO-GIC) on normal human osteoblasts (NHost cells). BIO-GIC was a glass ionomer cement (GIC) modified by adding chitosan and albumin to promote the release of TCTP. NHost cells were seeded on specimens of GIC, GIC + TCTP, BIO-GIC and BIO-GIC + TCTP. Cell proliferation was determined by BrdU assay. It was found that BIO-GIC + TCTP had significantly higher proliferation of cells than other specimens. Bone morphogenetic protein-2 (BMP-2) and osteopontin (OPN) gene expressions assessed by quantitative real time PCR and alkaline phosphatase (ALP) activity were used to determine cell differentiation. Bone cell function was investigated by calcium deposition using alizarin assay. Both BMP-2 and OPN gene expressions of cells cultured on specimens with added TCTP increased gradually up-regulation after day 1 and reached the highest on day 3 then down-regulation on day 7. The ALP activity of cells cultured on BIO-GIC + TCTP for 7 days and calcium content after 14 days were significantly higher than other groups. BIO-GIC + TCTP can promote osteoblast cells proliferation, differentiation and function. - Highlights: • Developed a new GIC by supplementing TCTP in BIO-GIC (GIC with chitosan and albumin) • BIO-GIC + TCTP released a higher amount of TCTP than GIC + TCTP. • BIO-GIC + TCTP promoted cell proliferation higher than other specimens and control. • BIO-GIC + TCTP promoted osteoblasts differentiation and function

  1. Translationally controlled tumor protein supplemented chitosan modified glass ionomer cement promotes osteoblast proliferation and function

    Energy Technology Data Exchange (ETDEWEB)

    Sangsuwan, Jiraporn [Department of Molecular Biology and Bioinformatics, Center for Genomics and Bioinformatics Research, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112 (Thailand); Department of Oral Biology and Occlusion, Faculty of Dentistry, Prince of Songkla University, Hat Yai, Songkhla 90112 (Thailand); Wanichpakorn, Supreya; Kedjarune-Leggat, Ureporn [Department of Oral Biology and Occlusion, Faculty of Dentistry, Prince of Songkla University, Hat Yai, Songkhla 90112 (Thailand)

    2015-09-01

    The objective of this study was to evaluate the effect of translationally controlled tumor protein (TCTP) supplemented in a novel glass ionomer cement (BIO-GIC) on normal human osteoblasts (NHost cells). BIO-GIC was a glass ionomer cement (GIC) modified by adding chitosan and albumin to promote the release of TCTP. NHost cells were seeded on specimens of GIC, GIC + TCTP, BIO-GIC and BIO-GIC + TCTP. Cell proliferation was determined by BrdU assay. It was found that BIO-GIC + TCTP had significantly higher proliferation of cells than other specimens. Bone morphogenetic protein-2 (BMP-2) and osteopontin (OPN) gene expressions assessed by quantitative real time PCR and alkaline phosphatase (ALP) activity were used to determine cell differentiation. Bone cell function was investigated by calcium deposition using alizarin assay. Both BMP-2 and OPN gene expressions of cells cultured on specimens with added TCTP increased gradually up-regulation after day 1 and reached the highest on day 3 then down-regulation on day 7. The ALP activity of cells cultured on BIO-GIC + TCTP for 7 days and calcium content after 14 days were significantly higher than other groups. BIO-GIC + TCTP can promote osteoblast cells proliferation, differentiation and function. - Highlights: • Developed a new GIC by supplementing TCTP in BIO-GIC (GIC with chitosan and albumin) • BIO-GIC + TCTP released a higher amount of TCTP than GIC + TCTP. • BIO-GIC + TCTP promoted cell proliferation higher than other specimens and control. • BIO-GIC + TCTP promoted osteoblasts differentiation and function.

  2. Role of heat shock proteins in cell apoptosis

    Directory of Open Access Journals (Sweden)

    Arleta Kaźmierczuk

    2010-06-01

    Full Text Available Apoptosis is, apart from necrosis and autophagy, one of the possible cell death mechanisms eliminating needless, not normal or infected cells. This process ensures quantitative and qualitative cell control of organisms. Apoptosis is tightly regulated, it requires both activation of a large number of genes and energy input. Up-to-date two main apoptotic pathways have been recognized – external/receptor and internal, processed with the participation of mitochondria. Heat shock proteins HSPs, the molecules known from their chaperone activity and molecular conservatism, play essential functions in the course of apoptosis. Among that proteins family, i.e. HSP100, 90, 70, 60, 40 and small molecular (sHSP, there are agents mainly protective against programmed cell death. However, in some conditions some of these proteins may promote apoptosis. This review describes different key apoptotic proteins interacting with main members of HSP family and the consequence of these events for cell survival or apoptosis.

  3. TIM-family proteins promote infection of multiple enveloped viruses through virion-associated phosphatidylserine.

    Directory of Open Access Journals (Sweden)

    Stephanie Jemielity

    2013-03-01

    Full Text Available Human T-cell Immunoglobulin and Mucin-domain containing proteins (TIM1, 3, and 4 specifically bind phosphatidylserine (PS. TIM1 has been proposed to serve as a cellular receptor for hepatitis A virus and Ebola virus and as an entry factor for dengue virus. Here we show that TIM1 promotes infection of retroviruses and virus-like particles (VLPs pseudotyped with a range of viral entry proteins, in particular those from the filovirus, flavivirus, New World arenavirus and alphavirus families. TIM1 also robustly enhanced the infection of replication-competent viruses from the same families, including dengue, Tacaribe, Sindbis and Ross River viruses. All interactions between TIM1 and pseudoviruses or VLPs were PS-mediated, as demonstrated with liposome blocking and TIM1 mutagenesis experiments. In addition, other PS-binding proteins, such as Axl and TIM4, promoted infection similarly to TIM1. Finally, the blocking of PS receptors on macrophages inhibited the entry of Ebola VLPs, suggesting that PS receptors can contribute to infection in physiologically relevant cells. Notably, infection mediated by the entry proteins of Lassa fever virus, influenza A virus and SARS coronavirus was largely unaffected by TIM1 expression. Taken together our data show that TIM1 and related PS-binding proteins promote infection of diverse families of enveloped viruses, and may therefore be useful targets for broad-spectrum antiviral therapies.

  4. Neural regeneration protein is a novel chemoattractive and neuronal survival-promoting factor

    International Nuclear Information System (INIS)

    Gorba, Thorsten; Bradoo, Privahini; Antonic, Ana; Marvin, Keith; Liu, Dong-Xu; Lobie, Peter E.; Reymann, Klaus G.; Gluckman, Peter D.; Sieg, Frank

    2006-01-01

    Neurogenesis and neuronal migration are the prerequisites for the development of the central nervous system. We have identified a novel rodent gene encoding for a neural regeneration protein (NRP) with an activity spectrum similar to the chemokine stromal-derived factor (SDF)-1, but with much greater potency. The Nrp gene is encoded as a forward frameshift to the hypothetical alkylated DNA repair protein AlkB. The predicted protein sequence of NRP contains domains with homology to survival-promoting peptide (SPP) and the trefoil protein TFF-1. The Nrp gene is first expressed in neural stem cells and expression continues in glial lineages. Recombinant NRP and NRP-derived peptides possess biological activities including induction of neural migration and proliferation, promotion of neuronal survival, enhancement of neurite outgrowth and promotion of neuronal differentiation from neural stem cells. NRP exerts its effect on neuronal survival by phosphorylation of the ERK1/2 and Akt kinases, whereas NRP stimulation of neural migration depends solely on p44/42 MAP kinase activity. Taken together, the expression profile of Nrp, the existence in its predicted protein structure of domains with similarities to known neuroprotective and migration-inducing factors and the high potency of NRP-derived synthetic peptides acting in femtomolar concentrations suggest it to be a novel gene of relevance in cellular and developmental neurobiology

  5. Tumor promoter induced membrane-bound protein kinase C - its influence on hematogenous metastasis

    International Nuclear Information System (INIS)

    Gopalakrishna, R.; Barsky, S.H.

    1987-01-01

    A correlation between the amount of membrane-bound detergent-extractable protein kinase C activity in various B16 melanoma sublines (F10, F1, BL6) and their lung metastasizing abilities following intravenous injection was found. The F10 subline which exhibits higher metastasizing ability was found to have higher membrane-bound protein kinase C compared to the lower metastasizing subline, F1. Treatment of F1 cells with 100 nM 12-0 tetradecanoylphorbol-13-acetate (TPA) for 1h resulted in 90% decrease in protein kinase C activity in the cytosol with a concommitent increase in membrane-bound activity. These TPA-treated cells when injected intravenously in C57BL/6 mice produced 6-fold increase in pulmonary metastases compared to untreated F1 cells. However, biologically inactive analogues 4 α-phorbol 12,13-didecanoate and phorbol 13-acetate had no effect on either membrane-bound protein kinase C activity or pulmonary metastases. Treating F1 cells with the second-stage tumor promoter, mezerin, resulted in increase in both membrane association of protein kinase C and also lung metastases. Thus, these results strongly suggests that membrane associated protein kinase C activity influences hematogenous metastasis of these melanoma cells

  6. TIM-1 Promotes Hepatitis C Virus Cell Attachment and Infection.

    Science.gov (United States)

    Wang, Jing; Qiao, Luhua; Hou, Zhouhua; Luo, Guangxiang

    2017-01-15

    Human TIM and TAM family proteins were recently found to serve as phosphatidylserine (PS) receptors which promote infections by many different viruses, including dengue virus, West Nile virus, Ebola virus, Marburg virus, and Zika virus. In the present study, we provide substantial evidence demonstrating that TIM-1 is important for efficient infection by hepatitis C virus (HCV). The knockdown of TIM-1 expression significantly reduced HCV infection but not HCV RNA replication. Likewise, TIM-1 knockout in Huh-7.5 cells remarkably lowered HCV cell attachment and subsequent HCV infection. More significantly, the impairment of HCV infection in the TIM-1 knockout cells could be restored completely by ectopic expression of TIM-1 but not TIM-3 or TIM-4. Additionally, HCV infection and cell attachment were inhibited by PS but not by phosphatidylcholine (PC), demonstrating that TIM-1-mediated enhancement of HCV infection is PS dependent. The exposure of PS on the HCV envelope was confirmed by immunoprecipitation of HCV particles with a PS-specific monoclonal antibody. Collectively, these findings demonstrate that TIM-1 promotes HCV infection by serving as an attachment receptor for binding to PS exposed on the HCV envelope. TIM family proteins were recently found to enhance infections by many different viruses, including several members of the Flaviviridae family. However, their importance in HCV infection has not previously been examined experimentally. The TIM family proteins include three members in humans: TIM-1, TIM-3, and TIM-4. The findings derived from our studies demonstrate that TIM-1, but not TIM-3 or TIM-4, promotes HCV infection by functioning as an HCV attachment factor. Knockout of the TIM-1 gene resulted in a remarkable reduction of HCV cell attachment and infection. PS-containing liposomes blocked HCV cell attachment and subsequent HCV infection. HCV particles could also be precipitated with a PS-specific monoclonal antibody. These findings suggest that TIM-1

  7. Rho GTPase activity modulates paramyxovirus fusion protein-mediated cell-cell fusion

    International Nuclear Information System (INIS)

    Schowalter, Rachel M.; Wurth, Mark A.; Aguilar, Hector C.; Lee, Benhur; Moncman, Carole L.; McCann, Richard O.; Dutch, Rebecca Ellis

    2006-01-01

    The paramyxovirus fusion protein (F) promotes fusion of the viral envelope with the plasma membrane of target cells as well as cell-cell fusion. The plasma membrane is closely associated with the actin cytoskeleton, but the role of actin dynamics in paramyxovirus F-mediated membrane fusion is unclear. We examined cell-cell fusion promoted by two different paramyxovirus F proteins in three cell types in the presence of constitutively active Rho family GTPases, major cellular coordinators of actin dynamics. Reporter gene and syncytia assays demonstrated that expression of either Rac1 V12 or Cdc42 V12 could increase cell-cell fusion promoted by the Hendra or SV5 glycoproteins, though the effect was dependent on the cell type expressing the viral glycoproteins. In contrast, RhoA L63 decreased cell-cell fusion promoted by Hendra glycoproteins but had little affect on SV5 F-mediated fusion. Also, data suggested that GTPase activation in the viral glycoprotein-containing cell was primarily responsible for changes in fusion. Additionally, we found that activated Cdc42 promoted nuclear rearrangement in syncytia

  8. p63 promotes cell survival through fatty acid synthase.

    Directory of Open Access Journals (Sweden)

    Venkata Sabbisetti

    2009-06-01

    Full Text Available There is increasing evidence that p63, and specifically DeltaNp63, plays a central role in both development and tumorigenesis by promoting epithelial cell survival. However, few studies have addressed the molecular mechanisms through which such important function is exerted. Fatty acid synthase (FASN, a key enzyme that synthesizes long-chain fatty acids and is involved in both embryogenesis and cancer, has been recently proposed as a direct target of p53 family members, including p63 and p73. Here we show that knockdown of either total or DeltaN-specific p63 isoforms in squamous cell carcinoma (SCC9 or immortalized prostate epithelial (iPrEC cells caused a decrease in cell viability by inducing apoptosis without affecting the cell cycle. p63 silencing significantly reduced both the expression and the activity of FASN. Importantly, stable overexpression of either FASN or myristoylated AKT (myr-AKT was able to partially rescue cells from cell death induced by p63 silencing. FASN induced AKT phosphorylation and a significant reduction in cell viability was observed when FASN-overexpressing SCC9 cells were treated with an AKT inhibitor after p63 knockdown, indicating that AKT plays a major role in FASN-mediated survival. Activated AKT did not cause any alteration in the FASN protein levels but induced its activity, suggesting that the rescue from apoptosis documented in the p63-silenced cells expressing myr-AKT cells may be partially mediated by FASN. Finally, we demonstrated that p63 and FASN expression are positively associated in clinical squamous cell carcinoma samples as well as in the developing prostate. Taken together, our findings demonstrate that FASN is a functionally relevant target of p63 and is required for mediating its pro-survival effects.

  9. Nifedipine promotes the proliferation and migration of breast cancer cells.

    Directory of Open Access Journals (Sweden)

    Dong-Qing Guo

    Full Text Available Nifedipine is widely used as a calcium channel blocker (CCB to treat angina and hypertension,but it is controversial with respect the risk of stimulation of cancers. In this study, we demonstrated that nifedipine promoted the proliferation and migration of breast cancer cells both invivo and invitro. However, verapamil, another calcium channel blocker, didn't exert the similar effects. Nifedipine and high concentration KCl failed to alter the [Ca2+]i in MDA-MB-231 cells, suggesting that such nifedipine effect was not related with calcium channel. Moreover, nifedipine decreased miRNA-524-5p, resulting in the up-regulation of brain protein I3 (BRI3. Erk pathway was consequently activated and led to the proliferation and migration of breast cancer cells. Silencing BRI3 reversed the promoting effect of nifedipine on the breast cancer. In a summary, nifedipine stimulated the proliferation and migration of breast cancer cells via the axis of miRNA-524-5p-BRI3-Erk pathway independently of its calcium channel-blocking activity. Our findings highlight that nifedipine but not verapamil is conducive for breast cancer growth and metastasis, urging that the caution should be taken in clinic to prescribe nifedipine to women who suffering both hypertension and breast cancer, and hypertension with a tendency in breast cancers.

  10. Aquaporin 2 promotes cell migration and epithelial morphogenesis.

    Science.gov (United States)

    Chen, Ying; Rice, William; Gu, Zhizhan; Li, Jian; Huang, Jianmin; Brenner, Michael B; Van Hoek, Alfred; Xiong, Jianping; Gundersen, Gregg G; Norman, Jim C; Hsu, Victor W; Fenton, Robert A; Brown, Dennis; Lu, Hua A Jenny

    2012-09-01

    The aquaporin 2 (AQP2) water channel, expressed in kidney collecting ducts, contributes critically to water homeostasis in mammals. Animals lacking or having significantly reduced levels of AQP2, however, have not only urinary concentrating abnormalities but also renal tubular defects that lead to neonatal mortality from renal failure. Here, we show that AQP2 is not only a water channel but also an integrin-binding membrane protein that promotes cell migration and epithelial morphogenesis. AQP2 expression modulates the trafficking and internalization of integrin β1, facilitating its turnover at focal adhesions. In vitro, disturbing the interaction between AQP2 and integrin β1 by mutating the RGD motif led to reduced endocytosis, retention of integrin β1 at the cell surface, and defective cell migration and tubulogenesis. Similarly, in vivo, AQP2-null mice exhibited significant retention of integrin β1 at the basolateral membrane and had tubular abnormalities. In summary, these data suggest that the water channel AQP2 interacts with integrins to promote renal epithelial cell migration, contributing to the structural and functional integrity of the mammalian kidney.

  11. Knotted vs. unknotted proteins: evidence of knot-promoting loops.

    Directory of Open Access Journals (Sweden)

    Raffaello Potestio

    Full Text Available Knotted proteins, because of their ability to fold reversibly in the same topologically entangled conformation, are the object of an increasing number of experimental and theoretical studies. The aim of the present investigation is to assess, on the basis of presently available structural data, the extent to which knotted proteins are isolated instances in sequence or structure space, and to use comparative schemes to understand whether specific protein segments can be associated to the occurrence of a knot in the native state. A significant sequence homology is found among a sizeable group of knotted and unknotted proteins. In this family, knotted members occupy a primary sub-branch of the phylogenetic tree and differ from unknotted ones only by additional loop segments. These "knot-promoting" loops, whose virtual bridging eliminates the knot, are found in various types of knotted proteins. Valuable insight into how knots form, or are encoded, in proteins could be obtained by targeting these regions in future computational studies or excision experiments.

  12. Arraying proteins by cell-free synthesis.

    Science.gov (United States)

    He, Mingyue; Wang, Ming-Wei

    2007-10-01

    Recent advances in life science have led to great motivation for the development of protein arrays to study functions of genome-encoded proteins. While traditional cell-based methods have been commonly used for generating protein arrays, they are usually a time-consuming process with a number of technical challenges. Cell-free protein synthesis offers an attractive system for making protein arrays, not only does it rapidly converts the genetic information into functional proteins without the need for DNA cloning, but also presents a flexible environment amenable to production of folded proteins or proteins with defined modifications. Recent advancements have made it possible to rapidly generate protein arrays from PCR DNA templates through parallel on-chip protein synthesis. This article reviews current cell-free protein array technologies and their proteomic applications.

  13. NSA2, a novel nucleolus protein regulates cell proliferation and cell cycle

    International Nuclear Information System (INIS)

    Zhang, Heyu; Ma, Xi; Shi, Taiping; Song, Quansheng; Zhao, Hongshan; Ma, Dalong

    2010-01-01

    NSA2 (Nop seven-associated 2) was previously identified in a high throughput screen of novel human genes associated with cell proliferation, and the NSA2 protein is evolutionarily conserved across different species. In this study, we revealed that NSA2 is broadly expressed in human tissues and cultured cell lines, and located in the nucleolus of the cell. Both of the putative nuclear localization signals (NLSs) of NSA2, also overlapped with nucleolar localization signals (NoLSs), are capable of directing nucleolar accumulation. Moreover, over-expression of the NSA2 protein promoted cell growth in different cell lines and regulated the G1/S transition in the cell cycle. SiRNA silencing of the NSA2 transcript attenuated the cell growth and dramatically blocked the cell cycle in G1/S transition. Our results demonstrated that NSA2 is a nucleolar protein involved in cell proliferation and cell cycle regulation.

  14. Clonorchis sinensis infestation promotes three-dimensional aggregation and invasion of cholangiocarcinoma cells.

    Directory of Open Access Journals (Sweden)

    Jihee Won

    Full Text Available Numerous experimental and epidemiological studies have demonstrated a correlation between Clonorchis sinensis (C. sinensis infestation and cholangiocarcinoma (CCA. However, the role of C. sinensis in the increased invasiveness and proliferation involved in the malignancy of CCA has not been addressed yet. Here, we investigated the possibility that C. sinensis infestation promotes expression of focal and cell-cell adhesion proteins in CCA cells and secretion of matrix metalloproteinases (MMPs. Adhesion proteins help maintain cell aggregates, and MMPs promote the three-dimensional invasion of cells into the neighboring extracellular matrix (ECM. Using a novel microfluidic assay, we quantitatively addressed the role of excretory-secretory products (ESPs gradients from C. sinensis in promoting the invasion of cells into the neighboring ECM.

  15. Growth hormone-promoted tyrosyl phosphorylation of SHC proteins and SHC association with Grb2

    DEFF Research Database (Denmark)

    VanderKuur, J; Allevato, G; Billestrup, Nils

    1995-01-01

    . To gain insight into pathways coupling GH receptor (GHR) to MAP kinase activation and signaling molecules that might interact with GHR and its associated tyrosine kinase JAK2, we examined whether SHC and Grb2 proteins serve as signaling molecules for GH. Human GH was shown to promote the rapid tyrosyl...... phosphorylation of 66-, 52-, and 46-kDa SHC proteins in 3T3-F442A fibroblasts. GH also promoted binding of GHR and JAK2 to the SH2 domain of 46/52-kDa SHC protein fused to glutathione S-transferase (GST). Constitutively phosphorylated JAK2, from COS-7 cells transiently transfected with murine JAK2 cDNA, bound......-638 and GHR1-638(Y333,338F), GH stimulated phosphorylation of all 3 SHC proteins whereas GH stimulated phosphorylation of only the 66- and 52-kDa SHC proteins in cells expressing GHR1-454. GH had no effect on SHC phosphorylation in cells expressing GHR1-294 or GHR delta P, the latter lacking amino acids 297...

  16. Interplay between chaperones and protein disorder promotes the evolution of protein networks.

    Directory of Open Access Journals (Sweden)

    Sebastian Pechmann

    2014-06-01

    Full Text Available Evolution is driven by mutations, which lead to new protein functions but come at a cost to protein stability. Non-conservative substitutions are of interest in this regard because they may most profoundly affect both function and stability. Accordingly, organisms must balance the benefit of accepting advantageous substitutions with the possible cost of deleterious effects on protein folding and stability. We here examine factors that systematically promote non-conservative mutations at the proteome level. Intrinsically disordered regions in proteins play pivotal roles in protein interactions, but many questions regarding their evolution remain unanswered. Similarly, whether and how molecular chaperones, which have been shown to buffer destabilizing mutations in individual proteins, generally provide robustness during proteome evolution remains unclear. To this end, we introduce an evolutionary parameter λ that directly estimates the rate of non-conservative substitutions. Our analysis of λ in Escherichia coli, Saccharomyces cerevisiae, and Homo sapiens sequences reveals how co- and post-translationally acting chaperones differentially promote non-conservative substitutions in their substrates, likely through buffering of their destabilizing effects. We further find that λ serves well to quantify the evolution of intrinsically disordered proteins even though the unstructured, thus generally variable regions in proteins are often flanked by very conserved sequences. Crucially, we show that both intrinsically disordered proteins and highly re-wired proteins in protein interaction networks, which have evolved new interactions and functions, exhibit a higher λ at the expense of enhanced chaperone assistance. Our findings thus highlight an intricate interplay of molecular chaperones and protein disorder in the evolvability of protein networks. Our results illuminate the role of chaperones in enabling protein evolution, and underline the

  17. HNF1 alpha activates the aminopeptidase N promoter in intestinal (Caco-2) cells

    DEFF Research Database (Denmark)

    Olsen, Jørgen; Laustsen, Lotte; Troelsen, J

    1994-01-01

    The importance of HNF1 binding proteins for intestinal aminopeptidase N expression was investigated using the Caco-2 cell-line. Aminopeptidase N promoter activity in Caco-2 cells depends on the HNF1 element (positions -85 to -58) and co-transfection with an HNF1 alpha expression vector demonstrates...... a direct activation of the promoter by HNF1 alpha through this element. Electrophoretic mobility shift assays using nuclear extracts from Caco-2 cells show the presence of high amounts of HNF1 binding proteins irrespective of their state of differentiation....

  18. HCV core protein promotes hepatocyte proliferation and chemoresistance by inhibiting NR4A1

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Yongsheng, E-mail: yongshengtanwhu@126.com; Li, Yan, E-mail: liyansd2@163.com

    2015-10-23

    This study investigated the effect of HCV core protein on the proliferation of hepatocytes and hepatocellular carcinoma cells (HCC), the influence of HCV core protein on HCC apoptosis induced by the chemotherapeutic agent cisplatin, and the mechanism through which HCV core protein acts as a potential oncoprotein in HCV-related HCC by measuring the levels of NR4A1 and Runt-related transcription factor 3 (RUNX3), which are associated with tumor suppression and chemotherapy resistance. In the present study, PcDNA3.1-core and RUNX3 siRNA were transfected into LO2 and HepG2 cells using Lipofectamine 2000. LO2-core, HepG2-core, LO2-RUNX3 {sup low} and control cells were treated with different concentrations of cisplatin for 72 h, and cell proliferation and apoptosis were assayed using the CellTiter 96{sup ®}Aqueous Non-Radioactive Cell Proliferation Assay Kit. Western blot and real time PCR analyses were used to detect NR4A1, RUNX3, smad7, Cyclin D1 and BAX. Confocal microscopy was used to determine the levels of NR4A1 in HepG2 and HepG2-core cells. The growth rate of HepG2-core cells was considerably greater than that of HepG2 cells. HCV core protein increased the expression of cyclin D1 and decreased the expressions of NR4A1 and RUNX3. In LO2 – RUNX3 {sup low}, the rate of cell proliferation and the level of cisplatin resistance were the same as in the LO2 -core. These results suggest that HCV core protein decreases the sensitivity of hepatocytes to cisplatin by inhibiting the expression of NR4A1 and promoting the expression of smad7, which negatively regulates the TGF-β pathway. This effect results in down regulation of RUNX3, a target of the TGF-β pathway. Taken together, these findings indicate that in hepatocytes, HCV core protein increases drug resistance and inhibits cell apoptosis by inhibiting the expressions of NR4A1 and RUNX3. - Highlights: • HCV core protein inhibits HepG2 cell sensitivity to cisplatin. • Core expression in HepG2 decreases

  19. HCV core protein promotes hepatocyte proliferation and chemoresistance by inhibiting NR4A1

    International Nuclear Information System (INIS)

    Tan, Yongsheng; Li, Yan

    2015-01-01

    This study investigated the effect of HCV core protein on the proliferation of hepatocytes and hepatocellular carcinoma cells (HCC), the influence of HCV core protein on HCC apoptosis induced by the chemotherapeutic agent cisplatin, and the mechanism through which HCV core protein acts as a potential oncoprotein in HCV-related HCC by measuring the levels of NR4A1 and Runt-related transcription factor 3 (RUNX3), which are associated with tumor suppression and chemotherapy resistance. In the present study, PcDNA3.1-core and RUNX3 siRNA were transfected into LO2 and HepG2 cells using Lipofectamine 2000. LO2-core, HepG2-core, LO2-RUNX3 "l"o"w and control cells were treated with different concentrations of cisplatin for 72 h, and cell proliferation and apoptosis were assayed using the CellTiter 96"®Aqueous Non-Radioactive Cell Proliferation Assay Kit. Western blot and real time PCR analyses were used to detect NR4A1, RUNX3, smad7, Cyclin D1 and BAX. Confocal microscopy was used to determine the levels of NR4A1 in HepG2 and HepG2-core cells. The growth rate of HepG2-core cells was considerably greater than that of HepG2 cells. HCV core protein increased the expression of cyclin D1 and decreased the expressions of NR4A1 and RUNX3. In LO2 – RUNX3 "l"o"w, the rate of cell proliferation and the level of cisplatin resistance were the same as in the LO2 -core. These results suggest that HCV core protein decreases the sensitivity of hepatocytes to cisplatin by inhibiting the expression of NR4A1 and promoting the expression of smad7, which negatively regulates the TGF-β pathway. This effect results in down regulation of RUNX3, a target of the TGF-β pathway. Taken together, these findings indicate that in hepatocytes, HCV core protein increases drug resistance and inhibits cell apoptosis by inhibiting the expressions of NR4A1 and RUNX3. - Highlights: • HCV core protein inhibits HepG2 cell sensitivity to cisplatin. • Core expression in HepG2 decreases expression of NR4A1

  20. Imaging protein-protein interactions in living cells

    NARCIS (Netherlands)

    Hink, M.A.; Bisseling, T.; Visser, A.J.W.G.

    2002-01-01

    The complex organization of plant cells makes it likely that the molecular behaviour of proteins in the test tube and the cell is different. For this reason, it is essential though a challenge to study proteins in their natural environment. Several innovative microspectroscopic approaches provide

  1. Cell-specific monitoring of protein synthesis in vivo.

    Directory of Open Access Journals (Sweden)

    Nikos Kourtis

    Full Text Available Analysis of general and specific protein synthesis provides important information, relevant to cellular physiology and function. However, existing methodologies, involving metabolic labelling by incorporation of radioactive amino acids into nascent polypeptides, cannot be applied to monitor protein synthesis in specific cells or tissues, in live specimens. We have developed a novel approach for monitoring protein synthesis in specific cells or tissues, in vivo. Fluorescent reporter proteins such as GFP are expressed in specific cells and tissues of interest or throughout animals using appropriate promoters. Protein synthesis rates are assessed by following fluorescence recovery after partial photobleaching of the fluorophore at targeted sites. We evaluate the method by examining protein synthesis rates in diverse cell types of live, wild type or mRNA translation-defective Caenorhabditis elegans animals. Because it is non-invasive, our approach allows monitoring of protein synthesis in single cells or tissues with intrinsically different protein synthesis rates. Furthermore, it can be readily implemented in other organisms or cell culture systems.

  2. TP508 accelerates fracture repair by promoting cell growth over cell death

    International Nuclear Information System (INIS)

    Li Xinmin; Wang Hali; Touma, Edward; Qi Yuchen; Rousseau, Emma; Quigg, Richard J.; Ryaby, James T.

    2007-01-01

    TP508 is a synthetic 23-amino acid peptide representing a receptor-binding domain of human thrombin. We have previously shown that a single injection of TP508 accelerates fracture healing in a rat femoral fracture model. To understand how TP508 acts at the protein level during fracture healing, we compared the translational profiles between saline-control and fractured femur at six time points after TP508 treatment using the second generation of BD Clontech TM Antibody Microarray. Here, we demonstrate that TP508 accelerates fracture healing by modulating expression levels of proteins primarily involved in the functional categories of cell cycle, cellular growth and proliferation, and cell death. The majority of those proteins are physically interrelated and functionally overlapped. The action of those proteins is highlighted by a central theme of promoting cell growth via balance of cell survival over cell death signals. This appears to occur through the stimulation of several bone healing pathways including cell cycle-G1/S checkpoint regulation, apoptosis, JAK/STAT, NF-κB, PDGF, PI3K/AKT, PTEN, and ERK/MAPK

  3. Hepatitis B X-interacting protein promotes cisplatin resistance and regulates CD147 via Sp1 in ovarian cancer.

    Science.gov (United States)

    Zou, Wei; Ma, Xiangdong; Yang, Hong; Hua, Wei; Chen, Biliang; Cai, Guoqing

    2017-03-01

    Ovarian cancer is the highest mortality rate of all female reproductive malignancies. Drug resistance is a major cause of treatment failure in malignant tumors. Hepatitis B X-interacting protein acts as an oncoprotein, regulates cell proliferation, and migration in breast cancer. We aimed to investigate the effects and mechanisms of hepatitis B X-interacting protein on resistance to cisplatin in human ovarian cancer cell lines. The mRNA and protein levels of hepatitis B X-interacting protein were detected using RT-PCR and Western blotting in cisplatin-resistant and cisplatin-sensitive tissues, cisplatin-resistant cell lines A2780/CP and SKOV3/CP, and cisplatin-sensitive cell lines A2780 and SKOV3. Cell viability and apoptosis were measured to evaluate cellular sensitivity to cisplatin in A2780/CP cells. Luciferase reporter gene assay was used to determine the relationship between hepatitis B X-interacting protein and CD147. The in vivo function of hepatitis B X-interacting protein on tumor burden was assessed in cisplatin-resistant xenograft models. The results showed that hepatitis B X-interacting protein was highly expressed in ovarian cancer of cisplatin-resistant tissues and cells. Notably, knockdown of hepatitis B X-interacting protein significantly reduced cell viability in A2780/CP compared with cisplatin treatment alone. Hepatitis B X-interacting protein and cisplatin cooperated to induce apoptosis and increase the expression of c-caspase 3 as well as the Bax/Bcl-2 ratio. We confirmed that hepatitis B X-interacting protein up-regulated CD147 at the protein expression and transcriptional levels. Moreover, we found that hepatitis B X-interacting protein was able to activate the CD147 promoter through Sp1. In vivo, depletion of hepatitis B X-interacting protein decreased the tumor volume and weight induced by cisplatin. Taken together, these results indicate that hepatitis B X-interacting protein promotes cisplatin resistance and regulated CD147 via Sp1 in

  4. Hepcidin promotes osteogenic differentiation through the bone morphogenetic protein 2/small mothers against decapentaplegic and mitogen-activated protein kinase/P38 signaling pathways in mesenchymal stem cells

    OpenAIRE

    LU, HUADING; LIAN, LIYI; SHI, DEHAI; ZHAO, HUIQING; DAI, YUHU

    2014-01-01

    The ability of mesenchymal stem cells (MSCs) to differentiate into osteogenic lineages requires management for their future use in treating bone destruction and osteoporosis. Hepcidin is closely associated with bone metabolism, however, it remains to be elucidated whether hepcidin affects osteogenic differentiation in MSCs. The present study demonstrated that hepcidin enhanced osteoblastic differentiation and mineralization, which was manifested by an upregulation in the differentiation marke...

  5. Murine Th9 cells promote the survival of myeloid dendritic cells in cancer immunotherapy.

    Science.gov (United States)

    Park, Jungsun; Li, Haiyan; Zhang, Mingjun; Lu, Yong; Hong, Bangxing; Zheng, Yuhuan; He, Jin; Yang, Jing; Qian, Jianfei; Yi, Qing

    2014-08-01

    Dendritic cells (DCs) are professional antigen-presenting cells to initiate immune responses, and DC survival time is important for affecting the strength of T-cell responses. Interleukin (IL)-9-producing T-helper (Th)-9 cells play an important role in anti-tumor immunity. However, it is unclear how Th9 cells communicate with DCs. In this study, we investigated whether murine Th9 cells affected the survival of myeloid DCs. DCs derived from bone marrow of C57BL/6 mice were cocultured with Th9 cells from OT-II mice using transwell, and the survival of DCs was examined. DCs cocultured with Th9 cells had longer survival and fewer apoptotic cells than DCs cultured alone in vitro. In melanoma B16-OVA tumor-bearing mice, DCs conditioned by Th9 cells lived longer and induced stronger anti-tumor response than control DCs did in vivo. Mechanistic studies revealed that IL-3 but not IL-9 secreted by Th9 cells was responsible for the prolonged survival of DCs. IL-3 upregulated the expression of anti-apoptotic protein Bcl-xL and activated p38, ERK and STAT5 signaling pathways in DCs. Taken together, our data provide the first evidence that Th9 cells can promote the survival of DCs through IL-3, and will be helpful for designing Th9 cell immunotherapy and more effective DC vaccine for human cancers.

  6. CD8 Follicular T Cells Promote B Cell Antibody Class Switch in Autoimmune Disease.

    Science.gov (United States)

    Valentine, Kristen M; Davini, Dan; Lawrence, Travis J; Mullins, Genevieve N; Manansala, Miguel; Al-Kuhlani, Mufadhal; Pinney, James M; Davis, Jason K; Beaudin, Anna E; Sindi, Suzanne S; Gravano, David M; Hoyer, Katrina K

    2018-05-09

    CD8 T cells can play both a protective and pathogenic role in inflammation and autoimmune development. Recent studies have highlighted the ability of CD8 T cells to function as T follicular helper (Tfh) cells in the germinal center in the context of infection. However, whether this phenomenon occurs in autoimmunity and contributes to autoimmune pathogenesis is largely unexplored. In this study, we show that CD8 T cells acquire a CD4 Tfh profile in the absence of functional regulatory T cells in both the IL-2-deficient and scurfy mouse models. Depletion of CD8 T cells mitigates autoimmune pathogenesis in IL-2-deficient mice. CD8 T cells express the B cell follicle-localizing chemokine receptor CXCR5, a principal Tfh transcription factor Bcl6, and the Tfh effector cytokine IL-21. CD8 T cells localize to the B cell follicle, express B cell costimulatory proteins, and promote B cell differentiation and Ab isotype class switching. These data reveal a novel contribution of autoreactive CD8 T cells to autoimmune disease, in part, through CD4 follicular-like differentiation and functionality. Copyright © 2018 by The American Association of Immunologists, Inc.

  7. Protein Availability and Satellite Cell Dynamics in Skeletal Muscle.

    Science.gov (United States)

    Shamim, Baubak; Hawley, John A; Camera, Donny M

    2018-06-01

    Human skeletal muscle satellite cells are activated in response to both resistance and endurance exercise. It was initially proposed that satellite cell proliferation and differentiation were only required to support resistance exercise-induced hypertrophy. However, satellite cells may also play a role in muscle fibre remodelling after endurance-based exercise and extracellular matrix regulation. Given the importance of dietary protein, particularly branched chain amino acids, in supporting myofibrillar and mitochondrial adaptations to both resistance and endurance-based training, a greater understanding of how protein intake impacts satellite cell activity would provide further insight into the mechanisms governing skeletal muscle remodelling with exercise. While many studies have investigated the capacity for protein ingestion to increase post-exercise rates of muscle protein synthesis, few investigations have examined the role for protein ingestion to modulate satellite cell activity. Here we review the molecular mechanisms controlling the activation of satellite cells in response to mechanical stress and protein intake in both in vitro and in vivo models. We provide a mechanistic framework that describes how protein ingestion may enhance satellite activity and promote exercise adaptations in human skeletal muscle.

  8. Ribosomal protein S6 phosphorylation and morphological changes in response to the tumour promoter 12-O-tetradecanoylphorbol 13-acetate in primary human tumour cells, established and transformed cell lines

    DEFF Research Database (Denmark)

    Rance, A J; Thönnes, M; Issinger, O G

    1985-01-01

    lifespan (fibroblasts, primary human tumour cells) can be mimicked by unknown steps also associated with immortalization (establishment function) and the transformed state of the tumour cells. Another interesting observation were morphological changes of the established and SV40-transformed cells which...

  9. Growth-promoting effect on iron-sulfur proteins on axenic cultures of Entamoeba dispar

    Directory of Open Access Journals (Sweden)

    Khalifa S.A.M.

    2006-03-01

    Full Text Available A growth-promoting factor (GPF that promotes the growth of Entamoeba dispar under axenic culture conditions was found in fractions of mitochondria (Mt, hydrogenosomes (Hg and chloroplasts (Cp obtained from cells of six different protozoan, mammalian and plant species. We were able to extract the GPF from the Cp-rich leaf cells of a plant (spiderwort: Commelina communis L. in an acetone-soluble fraction as a complex of chlorophyll with low molecular weight proteins (molecular weight [MW] approximately 4,600. We also found that on treatment with 0.6 % complexes of 2-mercapthoethanol (2ME, complexes of chlorophyll-a with iron-sulphur (Fe-S proteins (e.g., ferredoxins [Fd] from spinach and Clostridium pasteurianum and noncomplex rubredoxin (Rd from C. pasteurianum have a growth-promoting effect on E. dispar. These findings suggest that E. dispar may lack a sufficient quantity of some essential components of Fe-S proteins, such as Fe-S center.

  10. An essential GT motif in the lamin A promoter mediates activation by CREB-binding protein

    International Nuclear Information System (INIS)

    Janaki Ramaiah, M.; Parnaik, Veena K.

    2006-01-01

    Lamin A is an important component of nuclear architecture in mammalian cells. Mutations in the human lamin A gene lead to highly degenerative disorders that affect specific tissues. In studies directed towards understanding the mode of regulation of the lamin A promoter, we have identified an essential GT motif at -55 position by reporter gene assays and mutational analysis. Binding of this sequence to Sp transcription factors has been observed in electrophoretic mobility shift assays and by chromatin immunoprecipitation studies. Further functional analysis by co-expression of recombinant proteins and ChIP assays has shown an important regulatory role for CREB-binding protein in promoter activation, which is mediated by the GT motif

  11. Detecting protein-protein interactions in living cells

    DEFF Research Database (Denmark)

    Gottschalk, Marie; Bach, Anders; Hansen, Jakob Lerche

    2009-01-01

    to the endogenous C-terminal peptide of the NMDA receptor, as evaluated by a cell-free protein-protein interaction assay. However, it is important to address both membrane permeability and effect in living cells. Therefore a bioluminescence resonance energy transfer (BRET) assay was established, where the C......-terminal of the NMDA receptor and PDZ2 of PSD-95 were fused to green fluorescent protein (GFP) and Renilla luciferase (Rluc) and expressed in COS7 cells. A robust and specific BRET signal was obtained by expression of the appropriate partner proteins and subsequently, the assay was used to evaluate a Tat......The PDZ domain mediated interaction between the NMDA receptor and its intracellular scaffolding protein, PSD-95, is a potential target for treatment of ischemic brain diseases. We have recently developed a number of peptide analogues with improved affinity for the PDZ domains of PSD-95 compared...

  12. Hepatitis B virus X protein promotes interleukin-7 receptor expression via NF-κB and Notch1 pathway to facilitate proliferation and migration of hepatitis B virus-related hepatoma cells

    Directory of Open Access Journals (Sweden)

    Fanyun Kong

    2016-11-01

    Full Text Available Abstract Background Interleukin-7 receptor (IL-7R is involved in the abnormal function of solid tumors, but the role and regulatory mechanisms of IL-7R in HBV-related hepatocellular carcinoma (HCC are still unclear. Methods Gene and protein expression levels of IL-7R were examined in hepatoma cells transfected with hepatitis B virus (HBV plasmids and in hepatoma cells transfected with the multifunctional nonstructural protein X (HBX. The expression of HBX and IL-7R was measured by immunohistochemical analysis in HBV-related HCC tissues. The role of NF-κB and Notch1 pathways in HBX-mediated expression of IL-7R in hepatoma cells was examined. Activation of IL-7R downstream of intracellular signaling proteins AKT, JNK, STAT5, and the associated molecules CyclinD1 and matrix metalloproteinase-9 (MMP-9, was assessed in HBX-positive cells with or without treatment with IL-7R short hairpin RNA (shRNA. Additionally, the role of IL-7R in HBX-mediated proliferation and migration of hepatoma cells was investigated. Results The expression of IL-7R was increased in hepatoma cells transfected with HBV plasmids; HBX was responsible for the HBV-mediated upregulation of IL-7R. Compared to adjacent tissues, the expression of HBX and IL-7R was increased in HBV-related HCC tissues. Additionally, the relative expression levels of HBX were associated with IL-7R in HBV-related HCC tissues. The activation of NF-κB pathways and expression of Notch1 were increased in hepatoma cells transfected with HBX, and inhibition of NF-κB and Notch1 pathways significantly decreased HBX-mediated expression of IL-7R. The activation of AKT and JNK and the expression of CyclinD1 and MMP-9 were increased in HBX-positive cells. When cells were treated with IL-7R shRNA, the activation of AKT and JNK, as well as the expression of CyclinD1 and MMP-9, were significantly inhibited. Additionally, IL-7R was responsible for HBX-induced proliferation and migration ability of hepatoma cells

  13. Fetal liver stromal cells promote hematopoietic cell expansion

    International Nuclear Information System (INIS)

    Zhou, Kun; Hu, Caihong; Zhou, Zhigang; Huang, Lifang; Liu, Wenli; Sun, Hanying

    2009-01-01

    Future application of hematopoietic stem and progenitor cells (HSPCs) in clinical therapies largely depends on their successful expansion in vitro. Fetal liver (FL) is a unique hematopoietic organ in which hematopoietic cells markedly expand in number, but the mechanisms involved remain unclear. Stromal cells (StroCs) have been suggested to provide a suitable cellular environment for in vitro expansion of HSPCs. In this study, murine StroCs derived from FL at E14.5, with a high level of Sonic hedgehog (Shh) and Wnt expression, were found to have an increased ability to support the proliferation of HSPCs. This effect was inhibited by blocking Shh signaling. Supplementation with soluble Shh-N promoted the proliferation of hematopoietic cells by activating Wnt signaling. Our findings suggest that FL-derived StroCs support proliferation of HSPCs via Shh inducing an autocrine Wnt signaling loop. The use of FL-derived StroCs and regulation of the Shh pathway might further enhance HPSC expansion.

  14. HyCCAPP as a tool to characterize promoter DNA-protein interactions in Saccharomyces cerevisiae.

    Science.gov (United States)

    Guillen-Ahlers, Hector; Rao, Prahlad K; Levenstein, Mark E; Kennedy-Darling, Julia; Perumalla, Danu S; Jadhav, Avinash Y L; Glenn, Jeremy P; Ludwig-Kubinski, Amy; Drigalenko, Eugene; Montoya, Maria J; Göring, Harald H; Anderson, Corianna D; Scalf, Mark; Gildersleeve, Heidi I S; Cole, Regina; Greene, Alexandra M; Oduro, Akua K; Lazarova, Katarina; Cesnik, Anthony J; Barfknecht, Jared; Cirillo, Lisa A; Gasch, Audrey P; Shortreed, Michael R; Smith, Lloyd M; Olivier, Michael

    2016-06-01

    Currently available methods for interrogating DNA-protein interactions at individual genomic loci have significant limitations, and make it difficult to work with unmodified cells or examine single-copy regions without specific antibodies. In this study, we describe a physiological application of the Hybridization Capture of Chromatin-Associated Proteins for Proteomics (HyCCAPP) methodology we have developed. Both novel and known locus-specific DNA-protein interactions were identified at the ENO2 and GAL1 promoter regions of Saccharomyces cerevisiae, and revealed subgroups of proteins present in significantly different levels at the loci in cells grown on glucose versus galactose as the carbon source. Results were validated using chromatin immunoprecipitation. Overall, our analysis demonstrates that HyCCAPP is an effective and flexible technology that does not require specific antibodies nor prior knowledge of locally occurring DNA-protein interactions and can now be used to identify changes in protein interactions at target regions in the genome in response to physiological challenges. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Exosomes Promote Ovarian Cancer Cell Invasion through Transfer of CD44 to Peritoneal Mesothelial Cells.

    Science.gov (United States)

    Nakamura, Koji; Sawada, Kenjiro; Kinose, Yasuto; Yoshimura, Akihiko; Toda, Aska; Nakatsuka, Erika; Hashimoto, Kae; Mabuchi, Seiji; Morishige, Ken-Ichirou; Kurachi, Hirohisa; Lengyel, Ernst; Kimura, Tadashi

    2017-01-01

    Epithelial ovarian cancer (EOC) cells metastasize within the peritoneal cavity and directly encounter human peritoneal mesothelial cells (HPMC) as the initial step of metastasis. The contact between ovarian cancer cells and the single layer of mesothelial cells involves direct communications that modulate cancer progression but the mechanisms are unclear. One candidate mediating cell-cell communications is exosomes, 30-100 nm membrane vesicles of endocytic origin, through the cell-cell transfer of proteins, mRNAs, or microRNAs. Therefore, the goal was to mechanistically characterize how EOC-derived exosomes modulate metastasis. Exosomes from ovarian cancer cells were fluorescently labeled and cocultured with HPMCs which internalized the exosomes. Upon exosome uptake, HPMCs underwent a change in cellular morphology to a mesenchymal, spindle phenotype. CD44, a cell surface glycoprotein, was found to be enriched in the cancer cell-derived exosomes, transferred, and internalized to HPMCs, leading to high levels of CD44 in HPMCs. This increased CD44 expression in HPMCs promoted cancer invasion by inducing the HPMCs to secrete MMP9 and by cleaning the mesothelial barrier for improved cancer cell invasion. When CD44 expression was knocked down in cancer cells, exosomes had fewer effects on HPMCs. The inhibition of exosome release from cancer cells blocked CD44 internalization in HPMCs and suppressed ovarian cancer invasion. In ovarian cancer omental metastasis, positive CD44 expression was observed in those mesothelial cells that directly interacted with cancer cells, whereas CD44 expression was negative in the mesothelial cells remote from the invading edge. This study indicates that ovarian cancer-derived exosomes transfer CD44 to HPMCs, facilitating cancer invasion. Mechanistic insight from the current study suggests that therapeutic targeting of exosomes may be beneficial in treating ovarian cancer. Mol Cancer Res; 15(1); 78-92. ©2016 AACR. ©2016 American

  16. Proteomic analysis of the herpes simplex virus 1 virion protein 16 transactivator protein in infected cells.

    Science.gov (United States)

    Suk, Hyung; Knipe, David M

    2015-06-01

    The herpes simplex virus 1 virion protein 16 (VP16) tegument protein forms a transactivation complex with the cellular proteins host cell factor 1 (HCF-1) and octamer-binding transcription factor 1 (Oct-1) upon entry into the host cell. VP16 has also been shown to interact with a number of virion tegument proteins and viral glycoprotein H to promote viral assembly, but no comprehensive study of the VP16 proteome has been performed at early times postinfection. We therefore performed a proteomic analysis of VP16-interacting proteins at 3 h postinfection. We confirmed the interaction of VP16 with HCF-1 and a large number of cellular Mediator complex proteins, but most surprisingly, we found that the major viral protein associating with VP16 is the infected cell protein 4 (ICP4) immediate-early (IE) transactivator protein. These results raise the potential for a new function for VP16 in associating with the IE ICP4 and playing a role in transactivation of early and late gene expression, in addition to its well-documented function in transactivation of IE gene expression. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. BAG3: a multifaceted protein that regulates major cell pathways

    Science.gov (United States)

    Rosati, A; Graziano, V; De Laurenzi, V; Pascale, M; Turco, M C

    2011-01-01

    Bcl2-associated athanogene 3 (BAG3) protein is a member of BAG family of co-chaperones that interacts with the ATPase domain of the heat shock protein (Hsp) 70 through BAG domain (110–124 amino acids). BAG3 is the only member of the family to be induced by stressful stimuli, mainly through the activity of heat shock factor 1 on bag3 gene promoter. In addition to the BAG domain, BAG3 contains also a WW domain and a proline-rich (PXXP) repeat, that mediate binding to partners different from Hsp70. These multifaceted interactions underlie BAG3 ability to modulate major biological processes, that is, apoptosis, development, cytoskeleton organization and autophagy, thereby mediating cell adaptive responses to stressful stimuli. In normal cells, BAG3 is constitutively present in a very few cell types, including cardiomyocytes and skeletal muscle cells, in which the protein appears to contribute to cell resistance to mechanical stress. A growing body of evidence indicate that BAG3 is instead expressed in several tumor types. In different tumor contexts, BAG3 protein was reported to sustain cell survival, resistance to therapy, and/or motility and metastatization. In some tumor types, down-modulation of BAG3 levels was shown, as a proof-of-principle, to inhibit neoplastic cell growth in animal models. This review attempts to outline the emerging mechanisms that can underlie some of the biological activities of the protein, focusing on implications in tumor progression. PMID:21472004

  18. Follicular B Cells Promote Atherosclerosis via T Cell-Mediated Differentiation Into Plasma Cells and Secreting Pathogenic Immunoglobulin G.

    Science.gov (United States)

    Tay, Christopher; Liu, Yu-Han; Kanellakis, Peter; Kallies, Axel; Li, Yi; Cao, Anh; Hosseini, Hamid; Tipping, Peter; Toh, Ban-Hock; Bobik, Alex; Kyaw, Tin

    2018-05-01

    B cells promote or protect development of atherosclerosis. In this study, we examined the role of MHCII (major histocompatibility II), CD40 (cluster of differentiation 40), and Blimp-1 (B-lymphocyte-induced maturation protein) expression by follicular B (FO B) cells in development of atherosclerosis together with the effects of IgG purified from atherosclerotic mice. Using mixed chimeric Ldlr -/- mice whose B cells are deficient in MHCII or CD40, we demonstrate that these molecules are critical for the proatherogenic actions of FO B cells. During development of atherosclerosis, these deficiencies affected T-B cell interactions, germinal center B cells, plasma cells, and IgG. As FO B cells differentiating into plasma cells require Blimp-1, we also assessed its role in the development of atherosclerosis. Blimp-1-deficient B cells greatly attenuated atherosclerosis and immunoglobulin-including IgG production, preventing IgG accumulation in atherosclerotic lesions; Blimp-1 deletion also attenuated lesion proinflammatory cytokines, apoptotic cell numbers, and necrotic core. To determine the importance of IgG for atherosclerosis, we purified IgG from atherosclerotic mice. Their transfer but not IgG from nonatherosclerotic mice into Ldlr -/- mice whose B cells are Blimp-1-deficient increased atherosclerosis; transfer was associated with IgG accumulating in atherosclerotic lesions, increased lesion inflammatory cytokines, apoptotic cell numbers, and necrotic core size. The mechanism by which FO B cells promote atherosclerosis is highly dependent on their expression of MHCII, CD40, and Blimp-1. FO B cell differentiation into IgG-producing plasma cells also is critical for their proatherogenic actions. Targeting B-T cell interactions and pathogenic IgG may provide novel therapeutic strategies to prevent atherosclerosis and its adverse cardiovascular complications. © 2018 American Heart Association, Inc.

  19. The miR-599 promotes non-small cell lung cancer cell invasion via SATB2

    International Nuclear Information System (INIS)

    Tian, Wenjun; Wang, Guanghai; Liu, Yiqing; Huang, Zhenglan; Zhang, Caiqing; Ning, Kang; Yu, Cuixiang; Shen, Yajuan; Wang, Minghui; Li, Yuantang; Wang, Yong; Zhang, Bingchang; Zhao, Yaoran

    2017-01-01

    MicroRNAs (miRNAs) play important roles in the pathogenesis of many types of cancers by negatively regulating gene expression at posttranscriptional level. Here, we identified that miR-599 is up-regulated in non-small cell lung cancer (NSCLC) patients. It promoted NSCLC cell proliferation by negatively regulating SATB2. In NSCLC cell lines, CCK-8 proliferation assay indicated that the cell proliferation is promoted by miR-599 mimics. Transwell assay showed that miR-599 mimics promoted the invasion and migration of NSCLC cells. Luciferase assays confirmed that miR-599 directly binds to the 3'untranslated region of SATB2, and western blotting showed that miR-599 suppresses the expression of SATB2 at the protein level. This study indicates that miR-599 promotes proliferation and invasion of NSCLC cell lines via SATB2. The miR-599 may represent a potential therapeutic target for NSCLC treatment. - Highlights: • miR-599 is up-regulated in NSCLC. • miR-599 promotes the proliferation and invasion of NSCLC cells. • miR-599 inhibitors inhibits the proliferation and invasion of NSCLC cells. • miR-599 targets 3′ UTR of SATB2 in NSCLC cells. • miR-599 inhibits SATB2 in NSCLC cells.

  20. Insect Cells as Hosts for Recombinat Proteins

    OpenAIRE

    Murwani, Retno

    1997-01-01

    Since the development of recombinant baculovirus expression system, insect cell culture has rapidly gain popularity as the method of choice for production of a variety of biologically active proteins. Up to date tens of recombinant protein have been produced by this method commercially or non-commercially and have been widely used for research. This review describes the basic concept of baculovirus expression vector and the use of insect cells as host for recombinant proteins. Examples of the...

  1. Syndecan-1/CD147 association is essential for cyclophilin B-induced activation of p44/42 mitogen-activated protein kinases and promotion of cell adhesion and chemotaxis.

    Science.gov (United States)

    Pakula, Rachel; Melchior, Aurélie; Denys, Agnès; Vanpouille, Christophe; Mazurier, Joël; Allain, Fabrice

    2007-05-01

    Many of the biological functions attributed to cell surface proteoglycans are dependent on the interaction with extracellular mediators through their heparan sulphate (HS) moieties and the participation of their core proteins in signaling events. A class of recently identified inflammatory mediators is secreted cyclophilins, which are mostly known as cyclosporin A-binding proteins. We previously demonstrated that cyclophilin B (CyPB) triggers chemotaxis and integrin-mediated adhesion of T lymphocytes mainly of the CD4+/CD45RO+ phenotype. These activities are related to interactions with two types of binding sites, CD147 and cell surface HS. Here, we demonstrate that CyPB-mediated adhesion of CD4+/CD45RO+ T cells is related to p44/42 mitogen-activated protein kinase (MAPK) activation by a mechanism involving CD147 and HS proteoglycans (HSPG). Although HSPG core proteins are represented by syndecan-1, -2, -4, CD44v3 and betaglycan in CD4+/CD45RO+ T cells, we found that only syndecan-1 is physically associated with CD147. The intensity of the heterocomplex increased in response to CyPB, suggesting a transient enhancement and/or stabilization in the association of CD147 to syndecan-1. Pretreatment with anti-syndecan-1 antibodies or knockdown of syndecan-1 expression by RNA interference dramatically reduced CyPB-induced p44/p42 MAPK activation and consequent migration and adhesion, supporting the model in which syndecan-1 serves as a binding subunit to form the fully active receptor of CyPB. Altogether, our findings provide a novel example of a soluble mediator in which a member of the syndecan family plays a critical role in efficient interaction with signaling receptors and initiation of cellular responses.

  2. HOXB4 Promotes Hemogenic Endothelium Formation without Perturbing Endothelial Cell Development

    Directory of Open Access Journals (Sweden)

    Nadine Teichweyde

    2018-03-01

    Full Text Available Summary: Generation of hematopoietic stem cells (HSCs from pluripotent stem cells, in vitro, holds great promise for regenerative therapies. Primarily, this has been achieved in mouse cells by overexpression of the homeotic selector protein HOXB4. The exact cellular stage at which HOXB4 promotes hematopoietic development, in vitro, is not yet known. However, its identification is a prerequisite to unambiguously identify the molecular circuits controlling hematopoiesis, since the activity of HOX proteins is highly cell and context dependent. To identify that stage, we retrovirally expressed HOXB4 in differentiating mouse embryonic stem cells (ESCs. Through the use of Runx1(−/− ESCs containing a doxycycline-inducible Runx1 coding sequence, we uncovered that HOXB4 promoted the formation of hemogenic endothelium cells without altering endothelial cell development. Whole-transcriptome analysis revealed that its expression mediated the upregulation of transcription of core transcription factors necessary for hematopoiesis, culminating in the formation of blood progenitors upon initiation of Runx1 expression. : In this article, Klump and colleagues demonstrate that the human homeotic selector protein HOXB4 promotes ESC-derived hematopoiesis by inducing hemogenic endothelium formation, in vitro. It propels hematopoietic specification by upregulating the transcription of genes essential for hematopoietic development, such as those encoding members of the so-called heptad transcription factors. Keywords: HOXB4, hematopoietic stem cells, hemangioblast, hemogenic endothelium, hematopoietic specification, EHT, RUNX1, pluripotent stem cells

  3. Differential Regulation of Telomerase Reverse Transcriptase Promoter Activation and Protein Degradation by Histone Deacetylase Inhibition.

    Science.gov (United States)

    Qing, Hua; Aono, Jun; Findeisen, Hannes M; Jones, Karrie L; Heywood, Elizabeth B; Bruemmer, Dennis

    2016-06-01

    Telomerase reverse transcriptase (TERT) maintains telomeres and is rate limiting for replicative life span. While most somatic tissues silence TERT transcription resulting in telomere shortening, cells derived from cancer or cardiovascular diseases express TERT and activate telomerase. In the present study, we demonstrate that histone deacetylase (HDAC) inhibition induces TERT transcription and promoter activation. At the protein level in contrast, HDAC inhibition decreases TERT protein abundance through enhanced degradation, which decreases telomerase activity and induces senescence. Finally, we demonstrate that HDAC inhibition decreases TERT expression during vascular remodeling in vivo. These data illustrate a differential regulation of TERT transcription and protein stability by HDAC inhibition and suggest that TERT may constitute an important target for the anti-proliferative efficacy of HDAC inhibitors. © 2015 Wiley Periodicals, Inc.

  4. Is Melanoma a stem cell tumor? Identification of neurogenic proteins in trans-differentiated cells

    Directory of Open Access Journals (Sweden)

    Chan Linda S

    2005-03-01

    Full Text Available Abstract Background Although several genes and proteins have been implicated in the development of melanomas, the molecular mechanisms involved in the development of these tumors are not well understood. To gain a better understanding of the relationship between the cell growth, tumorigenesis and differentiation, we have studied a highly malignant cat melanoma cell line that trans-differentiates into neuronal cells after exposure to a feline endogenous retrovirus RD114. Methods To define the repertoire of proteins responsible for the phenotypic differences between melanoma and its counterpart trans-differentiated neuronal cells we have applied proteomics technology and compared protein profiles of the two cell types and identified differentially expressed proteins by 2D-gel electrophoresis, image analyses and mass spectrometry. Results The melanoma and trans-differentiated neuronal cells could be distinguished by the presence of distinct sets of proteins in each. Although approximately 60–70% of the expressed proteins were shared between the two cell types, twelve proteins were induced de novo after infection of melanoma cells with RD114 virus in vitro. Expression of these proteins in trans-differentiated cells was significantly associated with concomitant down regulation of growth promoting proteins and up-regulation of neurogenic proteins (p = 95% proteins expressed in trans-differentiated cells could be associated with the development, differentiation and regulation of nervous system cells. Conclusion Our results indicate that the cat melanoma cells have the ability to differentiate into distinct neuronal cell types and they express proteins that are essential for self-renewal. Since melanocytes arise from the neural crest of the embryo, we conclude that this melanoma arose from embryonic precursor stem cells. This model system provides a unique opportunity to identify domains of interactions between the expressed proteins that halt the

  5. Promoter motifs required for c-mpl gene expression induced by thrombopoietin in CMK cells.

    Science.gov (United States)

    Sunohara, Masataka; Sato, Iwao; Morikawa, Shigeru

    2017-11-30

    Thrombopoietin (TPO) and its receptor, c-Mpl, are the central regulators of megakaryocyte development and platelet production and are also crucial to regulate megakaryocytopoiesis. TPO remarkably elevated c-mpl promoter activity, while the protein kinase C (PKC) inhibitors, GF109203, H7 and Calphostin C, clearly reduced the steady level of its promoter activity.  In the present study, motifs crucial for c-mpl promoter activity induced by TPO treatment have been analyzed using a human megakaryoblastic cell line, CMK. Destruction of the -107Sp1 and the -57Sp1 sites in the c-mpl promoter enhancer region resulted in decrease of the promoter activity by 53.1% and 64.4%, respectively, and destruction of -69Ets and -28Ets elements dramatically decreased the promoter activity by 96.4% and 87.8%, respectively, while mutation of -77GATA moderately reduced the activity by 31.4%. The result was in agreement with our previous report that showed the crucial motifs in the c-mpl promoter for the promoter activity induced by PMA-treatment. This indicates that TPO-induced activation of the c-mpl promoter activity is fully modulated by transcription through a PKC-dependent pathway and the two Sp1 and two Ets motifs are crucial for the activation of the c-mpl promoter activity rather than a GATA motif in the c-mpl promoter of CMK cells.

  6. Cultivating Insect Cells To Produce Recombinant Proteins

    Science.gov (United States)

    Spaulding, Glenn; Goodwin, Thomas; Prewett, Tacey; Andrews, Angela; Francis, Karen; O'Connor, Kim

    1996-01-01

    Method of producing recombinant proteins involves growth of insect cells in nutrient solution in cylindrical bioreactor rotating about cylindrical axis, oriented horizontally and infecting cells with viruses into which genes of selected type cloned. Genes in question those encoding production of desired proteins. Horizontal rotating bioreactor preferred for use in method, denoted by acronym "HARV", described in "High-Aspect-Ratio Rotating Cell-Culture Vessel" (MSC-21662).

  7. Regulation of T cell activation by HIV-1 accessory proteins: Vpr acts via distinct mechanisms to cooperate with Nef in NFAT-directed gene expression and to promote transactivation by CREB

    International Nuclear Information System (INIS)

    Lahti, Anna L.; Manninen, Aki; Saksela, Kalle

    2003-01-01

    Nef and Vpr are lentiviral accessory proteins that have been implicated in regulation of cellular gene expression. We noticed that Vpr can potentiate Nef-induced activation of nuclear factor of activated T cells (NFAT)-dependent transcription. Unlike Nef, which stimulated calcium signaling to activate NFAT, Vpr functioned farther downstream. Similar to the positive effects of Vpr on most of the transcriptional test systems that we used, potentiation of NFAT-directed gene expression was relatively modest in magnitude (two- to threefold) and depended on the cell cycle-arresting capacity of Vpr. By contrast, we found that Vpr could cause more than fivefold upregulation of cyclic AMP response element (CRE)-directed transcription via a mechanism that did not require Vpr-induced G2/M arrest. This effect, however, was only evident under suboptimal conditions known to lead to serine phosphorylation of the CRE binding factor (CREB) but not to CREB-dependent gene expression. This suggested that Vpr may act by stabilizing interactions with CREB and its transcriptional cofactor CREB binding protein (CBP). Indeed, this effect could be blocked by cotransfection of the adenoviral CBP inhibitor E1A. These results provide additional evidence for cell cycle-independent regulation of gene expression by Vpr and implicate CREB as a potentially important target for Vpr action in HIV-infected host cells

  8. Metabolic behavior of cell surface biotinylated proteins

    International Nuclear Information System (INIS)

    Hare, J.F.; Lee, E.

    1989-01-01

    The turnover of proteins on the surface of cultured mammalian cells was measured by a new approach. Reactive free amino or sulfhydryl groups on surface-accessible proteins were derivatized with biotinyl reagents and the proteins solubilized from culture dishes with detergent. Solubilized, biotinylated proteins were then adsorbed onto streptavidin-agarose, released with sodium dodecyl sulfate and mercaptoethanol, and separated on polyacrylamide gels. Biotin-epsilon-aminocaproic acid N-hydroxysuccinimide ester (BNHS) or N-biotinoyl-N'-(maleimidohexanoyl)hydrazine (BM) were the derivatizing agents. Only 10-12 bands were adsorbed onto streptavidin-agarose from undervatized cells or from derivatized cells treated with free avidin at 4 degrees C. Two-dimensional isoelectric focusing-sodium dodecyl sulfate gel electrophoresis resolved greater than 100 BNHS-derivatized proteins and greater than 40 BM-derivatized proteins. There appeared to be little overlap between the two groups of derivatized proteins. Short-term pulse-chase studies showed an accumulation of label into both groups of biotinylated proteins up until 1-2 h of chase and a rapid decrease over the next 1-5 h. Delayed appearance of labeled protein at the cell surface was attributed to transit time from site of synthesis. The unexpected and unexplained rapid disappearance of pulse-labeled proteins from the cell surface was invariant for all two-dimensionally resolved proteins and was sensitive to temperature reduction to 18 degrees C. Long-term pulse-chase experiments beginning 4-8 h after the initiation of chase showed the disappearance of derivatized proteins to be a simple first-order process having a half-life of 115 h in the case of BNHS-derivatized proteins and 30 h in the case of BM-derivatized proteins

  9. A component of green tea (-)-epigallocatechin-3-gallate, promotes apoptosis in T24 human bladder cancer cells via modulation of the PI3K/Akt pathway and Bcl-2 family proteins

    International Nuclear Information System (INIS)

    Qin Jie; Xie Liping; Zheng Xiangyi; Wang Yunbin; Bai Yu; Shen Huafeng; Li Longcheng; Dahiya, Rajvir

    2007-01-01

    Bladder cancer is the fourth most common cancer in men and ninth most common in women. It has a protracted course of progression and is thus an ideal candidate for chemoprevention strategies and trials. This study was conducted to evaluate the chemopreventive/antiproliferative potential of (-)-epigallocatechin gallate (EGCG, the major phytochemical in green tea) against bladder cancer and its mechanism of action. Using the T24 human bladder cancer cell line, we found that EGCG treatment caused dose- and time-dependent inhibition of cellular proliferation and cell viability, and induced apoptosis. Mechanistically, EGCG inhibits phosphatidylinositol 3'-kinase/Akt activation that, in turn, results in modulation of Bcl-2 family proteins, leading to enhanced apoptosis of T24 cells. These findings suggest that EGCG may be an important chemoprevention agent for the management of bladder cancer

  10. Thermodynamics of protein destabilization in live cells.

    Science.gov (United States)

    Danielsson, Jens; Mu, Xin; Lang, Lisa; Wang, Huabing; Binolfi, Andres; Theillet, François-Xavier; Bekei, Beata; Logan, Derek T; Selenko, Philipp; Wennerström, Håkan; Oliveberg, Mikael

    2015-10-06

    Although protein folding and stability have been well explored under simplified conditions in vitro, it is yet unclear how these basic self-organization events are modulated by the crowded interior of live cells. To find out, we use here in-cell NMR to follow at atomic resolution the thermal unfolding of a β-barrel protein inside mammalian and bacterial cells. Challenging the view from in vitro crowding effects, we find that the cells destabilize the protein at 37 °C but with a conspicuous twist: While the melting temperature goes down the cold unfolding moves into the physiological regime, coupled to an augmented heat-capacity change. The effect seems induced by transient, sequence-specific, interactions with the cellular components, acting preferentially on the unfolded ensemble. This points to a model where the in vivo influence on protein behavior is case specific, determined by the individual protein's interplay with the functionally optimized "interaction landscape" of the cellular interior.

  11. Protein Kinase C-ε Promotes EMT in Breast Cancer

    Science.gov (United States)

    Jain, Kirti; Basu, Alakananda

    2014-01-01

    Protein kinase C (PKC), a family of serine/threonine kinases, plays critical roles in signal transduction and cell regulation. PKCε, a member of the novel PKC family, is known to be a transforming oncogene and a tumor biomarker for aggressive breast cancers. In this study, we examined the involvement of PKCε in epithelial to mesenchymal transition (EMT), the process that leads the way to metastasis. Overexpression of PKCε was sufficient to induce a mesenchymal phenotype in non-tumorigenic mammary epithelial MCF-10 A cells. This was accompanied by a decrease in the epithelial markers, such as E-cadherin, zonula occludens (ZO)-1, and claudin-1, and an increase in mesenchymal marker vimentin. Transforming growth factor β (TGFβ) induced Snail expression and mesenchymal morphology in MCF-10 A cells, and these effects were partially reversed by the PKCε knockdown. PKCε also mediated cell migration and anoikis resistance, which are hallmarks of EMT. Thus, our study demonstrates that PKCε is an important mediator of EMT in breast cancer. PMID:24701121

  12. A Poly(Lactic-co-Glycolic) Acid Nanovaccine Based on Chimeric Peptides from Different Leishmania infantum Proteins Induces Dendritic Cells Maturation and Promotes Peptide-Specific IFNγ-Producing CD8+ T Cells Essential for the Protection against Experimental Visceral Leishmaniasis.

    Science.gov (United States)

    Athanasiou, Evita; Agallou, Maria; Tastsoglou, Spyros; Kammona, Olga; Hatzigeorgiou, Artemis; Kiparissides, Costas; Karagouni, Evdokia

    2017-01-01

    Visceral leishmaniasis, caused by Leishmania ( L .) donovani and L. infantum protozoan parasites, can provoke overwhelming and protracted epidemics, with high case-fatality rates. An effective vaccine against the disease must rely on the generation of a strong and long-lasting T cell immunity, mediated by CD4 + T H1 and CD8 + T cells. Multi-epitope peptide-based vaccine development is manifesting as the new era of vaccination strategies against Leishmania infection. In this study, we designed chimeric peptides containing HLA-restricted epitopes from three immunogenic L. infantum proteins (cysteine peptidase A, histone H1, and kinetoplastid membrane protein 11), in order to be encapsulated in poly(lactic- co -glycolic) acid nanoparticles with or without the adjuvant monophosphoryl lipid A (MPLA) or surface modification with an octapeptide targeting the tumor necrosis factor receptor II. We aimed to construct differentially functionalized peptide-based nanovaccine candidates and investigate their capacity to stimulate the immunomodulatory properties of dendritic cells (DCs), which are critical regulators of adaptive immunity generated upon vaccination. According to our results, DCs stimulation with the peptide-based nanovaccine candidates with MPLA incorporation or surface modification induced an enhanced maturation profile with prominent IL-12 production, promoting allogeneic T cell proliferation and intracellular production of IFNγ by CD4 + and CD8 + T cell subsets. In addition, DCs stimulated with the peptide-based nanovaccine candidate with MPLA incorporation exhibited a robust transcriptional activation, characterized by upregulated genes indicative of vaccine-driven DCs differentiation toward type 1 phenotype. Immunization of HLA A2.1 transgenic mice with this peptide-based nanovaccine candidate induced peptide-specific IFNγ-producing CD8 + T cells and conferred significant protection against L. infantum infection. Concluding, our findings supported that

  13. Dendritic Cells Promote Pancreatic Viability in Mice with Acute Pancreatitis

    Science.gov (United States)

    Bedrosian, Andrea S.; Nguyen, Andrew H.; Hackman, Michael; Connolly, Michael K.; Malhotra, Ashim; Ibrahim, Junaid; Cieza-Rubio, Napoleon E.; Henning, Justin R.; Barilla, Rocky; Rehman, Adeel; Pachter, H. Leon; Medina-Zea, Marco V.; Cohen, Steven M.; Frey, Alan B.; Acehan, Devrim; Miller, George

    2011-01-01

    Background & Aims Acute pancreatitis increases morbidity and mortality from organ necrosis by mechanisms that are incompletely understood. Dendritic cells (DCs) can promote or suppress inflammation, depending on their subtype and context. We investigated the roles of DC in development of acute pancreatitis. Methods Acute pancreatitis was induced in CD11c.DTR mice using caerulein or L-arginine; DCs were depleted by administration of diphtheria toxin. Survival was analyzed using Kaplan-Meier analysis. Results Numbers of MHC II+CD11c+DC increased 100-fold in pancreas of mice with acute pancreatitis, to account for nearly 15% of intra-pancreatic leukocytes. Intra-pancreatic DC acquired an immune phenotype in mice with acute pancreatitis; they expressed higher levels of MHC II and CD86 and increased production of interleukin-6, membrane cofactor protein (MCP)-1, and tumor necrosis factor (TNF)-α. However, rather than inducing an organ-destructive inflammatory process, DC were required for pancreatic viability; the exocrine pancreas died in mice that were depleted of DC and challenged with caerulein or L-arginine. All mice with pancreatitis that were depleted of DC died from acinar cell death within 4 days. Depletion of DC from mice with pancreatitis resulted in neutrophil infiltration and increased levels of systemic markers of inflammation. However, the organ necrosis associated with depletion of DC did not require infiltrating neutrophils, activation of NF-κB, or signaling by mitogen-activated protein kinase or TNF-α. Conclusions DC are required for pancreatic viability in mice with acute pancreatitis and might protect organs against cell stress. PMID:21801698

  14. Functional dynamics of cell surface membrane proteins.

    Science.gov (United States)

    Nishida, Noritaka; Osawa, Masanori; Takeuchi, Koh; Imai, Shunsuke; Stampoulis, Pavlos; Kofuku, Yutaka; Ueda, Takumi; Shimada, Ichio

    2014-04-01

    Cell surface receptors are integral membrane proteins that receive external stimuli, and transmit signals across plasma membranes. In the conventional view of receptor activation, ligand binding to the extracellular side of the receptor induces conformational changes, which convert the structure of the receptor into an active conformation. However, recent NMR studies of cell surface membrane proteins have revealed that their structures are more dynamic than previously envisioned, and they fluctuate between multiple conformations in an equilibrium on various timescales. In addition, NMR analyses, along with biochemical and cell biological experiments indicated that such dynamical properties are critical for the proper functions of the receptors. In this review, we will describe several NMR studies that revealed direct linkage between the structural dynamics and the functions of the cell surface membrane proteins, such as G-protein coupled receptors (GPCRs), ion channels, membrane transporters, and cell adhesion molecules. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Two Nucleolar Proteins, GDP1 and OLI2, Function As Ribosome Biogenesis Factors and Are Preferentially Involved in Promotion of Leaf Cell Proliferation without Strongly Affecting Leaf Adaxial–Abaxial Patterning in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Koji Kojima

    2018-01-01

    Full Text Available Leaf abaxial–adaxial patterning is dependent on the mutual repression of leaf polarity genes expressed either adaxially or abaxially. In Arabidopsis thaliana, this process is strongly affected by mutations in ribosomal protein genes and in ribosome biogenesis genes in a sensitized genetic background, such as asymmetric leaves2 (as2. Most ribosome-related mutants by themselves do not show leaf abaxialization, and one of their typical phenotypes is the formation of pointed rather than rounded leaves. In this study, we characterized two ribosome-related mutants to understand how ribosome biogenesis is linked to several aspects of leaf development. Previously, we isolated oligocellula2 (oli2 which exhibits the pointed-leaf phenotype and has a cell proliferation defect. OLI2 encodes a homolog of Nop2 in Saccharomyces cerevisiae, a ribosome biogenesis factor involved in pre-60S subunit maturation. In this study, we found another pointed-leaf mutant that carries a mutation in a gene encoding an uncharacterized protein with a G-patch domain. Similar to oli2, this mutant, named g-patch domain protein1 (gdp1, has a reduced number of leaf cells. In addition, gdp1 oli2 double mutants showed a strong genetic interaction such that they synergistically impaired cell proliferation in leaves and produced markedly larger cells. On the other hand, they showed additive phenotypes when combined with several known ribosomal protein mutants. Furthermore, these mutants have a defect in pre-rRNA processing. GDP1 and OLI2 are strongly expressed in tissues with high cell proliferation activity, and GDP1-GFP and GFP-OLI2 are localized in the nucleolus. These results suggest that OLI2 and GDP1 are involved in ribosome biogenesis. We then examined the effects of gdp1 and oli2 on adaxial–abaxial patterning by crossing them with as2. Interestingly, neither gdp1 nor oli2 strongly enhanced the leaf polarity defect of as2. Similar results were obtained with as2 gdp1 oli2

  16. NSs Protein of Rift Valley Fever Virus Promotes Posttranslational Downregulation of the TFIIH Subunit p62▿

    Science.gov (United States)

    Kalveram, Birte; Lihoradova, Olga; Ikegami, Tetsuro

    2011-01-01

    Rift Valley fever virus (RVFV; family Bunyaviridae, genus Phlebovirus) is an important emerging pathogen of humans and ruminants. Its NSs protein has previously been identified as a major virulence factor that suppresses host defense through three distinct mechanisms: it directly inhibits beta interferon (IFN-β) promoter activity, it promotes the degradation of double-stranded RNA-dependent protein kinase (PKR), and it suppresses host transcription by disrupting the assembly of the basal transcription factor TFIIH through sequestration of its p44 subunit. Here, we report that in addition to PKR, NSs also promotes the degradation of the TFIIH subunit p62. Infection of cells with the RVFV MP-12 vaccine strain reduced p62 protein levels to below the detection limit early in the course of infection. This NSs-mediated downregulation of p62 was posttranslational, as it was unaffected by pharmacological inhibition of transcription or translation and MP-12 infection had no effect on p62 mRNA levels. Treatment of cells with proteasome inhibitors but not inhibition of lysosomal acidification or nuclear export resulted in a stabilization of p62 in the presence of NSs. Furthermore, p62 could be coprecipitated with NSs from lysates of infected cells. These data suggest that the RVFV NSs protein is able to interact with the TFIIH subunit p62 inside infected cells and promotes its degradation, which can occur directly in the nucleus. PMID:21543505

  17. Nanoparticles-cell association predicted by protein corona fingerprints

    Science.gov (United States)

    Palchetti, S.; Digiacomo, L.; Pozzi, D.; Peruzzi, G.; Micarelli, E.; Mahmoudi, M.; Caracciolo, G.

    2016-06-01

    In a physiological environment (e.g., blood and interstitial fluids) nanoparticles (NPs) will bind proteins shaping a ``protein corona'' layer. The long-lived protein layer tightly bound to the NP surface is referred to as the hard corona (HC) and encodes information that controls NP bioactivity (e.g. cellular association, cellular signaling pathways, biodistribution, and toxicity). Decrypting this complex code has become a priority to predict the NP biological outcomes. Here, we use a library of 16 lipid NPs of varying size (Ø ~ 100-250 nm) and surface chemistry (unmodified and PEGylated) to investigate the relationships between NP physicochemical properties (nanoparticle size, aggregation state and surface charge), protein corona fingerprints (PCFs), and NP-cell association. We found out that none of the NPs' physicochemical properties alone was exclusively able to account for association with human cervical cancer cell line (HeLa). For the entire library of NPs, a total of 436 distinct serum proteins were detected. We developed a predictive-validation modeling that provides a means of assessing the relative significance of the identified corona proteins. Interestingly, a minor fraction of the HC, which consists of only 8 PCFs were identified as main promoters of NP association with HeLa cells. Remarkably, identified PCFs have several receptors with high level of expression on the plasma membrane of HeLa cells.In a physiological environment (e.g., blood and interstitial fluids) nanoparticles (NPs) will bind proteins shaping a ``protein corona'' layer. The long-lived protein layer tightly bound to the NP surface is referred to as the hard corona (HC) and encodes information that controls NP bioactivity (e.g. cellular association, cellular signaling pathways, biodistribution, and toxicity). Decrypting this complex code has become a priority to predict the NP biological outcomes. Here, we use a library of 16 lipid NPs of varying size (Ø ~ 100-250 nm) and surface

  18. H2A/K pseudogene mutation may promote cell proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Jisheng; Jing, Ruirui; Lv, Xin; Wang, Xiaoyue; Li, Junqiang; Li, Lin; Li, Cuiling; Wang, Daoguang; Bi, Baibing; Chen, Xinjun [Cancer Research Center, Shandong University School of Medicine, Jinan 250012 (China); Yang, Jing-Hua, E-mail: sdu_crc_group1@126.com [Cancer Research Center, Shandong University School of Medicine, Jinan 250012 (China); Department of Surgery, VA Boston Healthcare System, Boston University School of Medicine, Boston 510660, MA (United States)

    2016-05-15

    Highlights: • The mutant H2A/K pseudogene is active. • The mutant H2A/K pseudogene can promote cell proliferation. - Abstract: Little attention has been paid to the histone H2A/K pseudogene. Results from our laboratory showed that 7 of 10 kidney cancer patients carried a mutant H2A/K pseudogene; therefore, we were interested in determining the relationship between mutant H2A/K and cell proliferation. We used shotgun and label-free proteomics methods to study whether mutant H2A/K lncRNAs affected cell proliferation. Quantitative proteomic analysis indicated that the expression of mutant H2A/K lncRNAs resulted in the upregulation of many oncogenes, which promoted cell proliferation. Further interaction analyses revealed that a proliferating cell nuclear antigen (PCNA)-protein interaction network, with PCNA in the center, contributes to cell proliferation in cells expressing the mutant H2A/K lncRNAs. Western blotting confirmed the critical upregulation of PCNA by mutant H2A/K lncRNA expression. Finally, the promotion of cell proliferation by mutant H2A/K lncRNAs (C290T, C228A and A45G) was confirmed using cell proliferation assays. Although we did not determine the exact mechanism by which the oncogenes were upregulated by the mutant H2A/K lncRNAs, we confirmed that the mutant H2A/K lncRNAs promoted cell proliferation by upregulating PCNA and other oncogenes. The hypothesis that cell proliferation is promoted by the mutant H2A/K lncRNAs was supported by the protein expression and cell proliferation assay results. Therefore, mutant H2A/K lncRNAs may be a new factor in renal carcinogenesis.

  19. Ubiquitin-like protein UBL5 promotes the functional integrity of the Fanconi anemia pathway.

    Science.gov (United States)

    Oka, Yasuyoshi; Bekker-Jensen, Simon; Mailand, Niels

    2015-05-12

    Ubiquitin and ubiquitin-like proteins (UBLs) function in a wide array of cellular processes. UBL5 is an atypical UBL that does not form covalent conjugates with cellular proteins and which has a known role in modulating pre-mRNA splicing. Here, we report an unexpected involvement of human UBL5 in promoting the function of the Fanconi anemia (FA) pathway for repair of DNA interstrand crosslinks (ICLs), mediated by a specific interaction with the central FA pathway component FANCI. UBL5-deficient cells display spliceosome-independent reduction of FANCI protein stability, defective FANCI function in response to DNA damage and hypersensitivity to ICLs. By mapping the sequence determinants underlying UBL5-FANCI binding, we generated separation-of-function mutants to demonstrate that key aspects of FA pathway function, including FANCI-FANCD2 heterodimerization, FANCD2 and FANCI monoubiquitylation and maintenance of chromosome stability after ICLs, are compromised when the UBL5-FANCI interaction is selectively inhibited by mutations in either protein. Together, our findings establish UBL5 as a factor that promotes the functionality of the FA DNA repair pathway. © 2015 The Authors.

  20. Neural stem cells promote nerve regeneration through IL12-induced Schwann cell differentiation.

    Science.gov (United States)

    Lee, Don-Ching; Chen, Jong-Hang; Hsu, Tai-Yu; Chang, Li-Hsun; Chang, Hsu; Chi, Ya-Hui; Chiu, Ing-Ming

    2017-03-01

    Regeneration of injured peripheral nerves is a slow, complicated process that could be improved by implantation of neural stem cells (NSCs) or nerve conduit. Implantation of NSCs along with conduits promotes the regeneration of damaged nerve, likely because (i) conduit supports and guides axonal growth from one nerve stump to the other, while preventing fibrous tissue ingrowth and retaining neurotrophic factors; and (ii) implanted NSCs differentiate into Schwann cells and maintain a growth factor enriched microenvironment, which promotes nerve regeneration. In this study, we identified IL12p80 (homodimer of IL12p40) in the cell extracts of implanted nerve conduit combined with NSCs by using protein antibody array and Western blotting. Levels of IL12p80 in these conduits are 1.6-fold higher than those in conduits without NSCs. In the sciatic nerve injury mouse model, implantation of NSCs combined with nerve conduit and IL12p80 improves motor recovery and increases the diameter up to 4.5-fold, at the medial site of the regenerated nerve. In vitro study further revealed that IL12p80 stimulates the Schwann cell differentiation of mouse NSCs through the phosphorylation of signal transducer and activator of transcription 3 (Stat3). These results suggest that IL12p80 can trigger Schwann cell differentiation of mouse NSCs through Stat3 phosphorylation and enhance the functional recovery and the diameter of regenerated nerves in a mouse sciatic nerve injury model. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Promoter, transgene, and cell line effects in the transfection of mammalian cells using PDMAEMA-based nano-stars

    Directory of Open Access Journals (Sweden)

    Alexander Raup

    2016-09-01

    Full Text Available Non-viral transfection protocols are typically optimized using standard cells and reporter proteins, potentially underestimating cellular or transgene effects. Here such effects were studied for two human (Jurkat, HEK-293 and two rodent (CHO-K1, L929 cell lines and three fluorescent reporter proteins. Expression of the enhanced green fluorescent protein (EGFP was studied under the control of the human elongation factor 1 alpha promoter and three viral promoters (SV40, SV40/enhancer, CMV, that of ZsYellow1 (yellow fluorescence and mCherry (red fluorescence for the CMV promoter. Results varied with the cell line, in particular for the Jurkat cells. Pair-wise co-transfection of the CMV controlled transgenes resulted in a significant fraction of monochromatic cells (EGFP for EGFP/YFP and EGFP/RFP co-transfections, YFP in case of YFP/RFP co-transfections. Only Jurkat cells were almost incapable of expressing YFP. Dilution of the plasmid DNA with a non-expressed plasmid showed cell line dependent effects on transfection efficiency and/or expression levels.

  2. Centrobin-centrosomal protein 4.1-associated protein (CPAP) interaction promotes CPAP localization to the centrioles during centriole duplication.

    Science.gov (United States)

    Gudi, Radhika; Zou, Chaozhong; Dhar, Jayeeta; Gao, Qingshen; Vasu, Chenthamarakshan

    2014-05-30

    Centriole duplication is the process by which two new daughter centrioles are generated from the proximal end of preexisting mother centrioles. Accurate centriole duplication is important for many cellular and physiological events, including cell division and ciliogenesis. Centrosomal protein 4.1-associated protein (CPAP), centrosomal protein of 152 kDa (CEP152), and centrobin are known to be essential for centriole duplication. However, the precise mechanism by which they contribute to centriole duplication is not known. In this study, we show that centrobin interacts with CEP152 and CPAP, and the centrobin-CPAP interaction is critical for centriole duplication. Although depletion of centrobin from cells did not have an effect on the centriolar levels of CEP152, it caused the disappearance of CPAP from both the preexisting and newly formed centrioles. Moreover, exogenous expression of the CPAP-binding fragment of centrobin also caused the disappearance of CPAP from both the preexisting and newly synthesized centrioles, possibly in a dominant negative manner, thereby inhibiting centriole duplication and the PLK4 overexpression-mediated centrosome amplification. Interestingly, exogenous overexpression of CPAP in the centrobin-depleted cells did not restore CPAP localization to the centrioles. However, restoration of centrobin expression in the centrobin-depleted cells led to the reappearance of centriolar CPAP. Hence, we conclude that centrobin-CPAP interaction is critical for the recruitment of CPAP to procentrioles to promote the elongation of daughter centrioles and for the persistence of CPAP on preexisting mother centrioles. Our study indicates that regulation of CPAP levels on the centrioles by centrobin is critical for preserving the normal size, shape, and number of centrioles in the cell. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  3. Centrobin-Centrosomal Protein 4.1-associated Protein (CPAP) Interaction Promotes CPAP Localization to the Centrioles during Centriole Duplication*

    Science.gov (United States)

    Gudi, Radhika; Zou, Chaozhong; Dhar, Jayeeta; Gao, Qingshen; Vasu, Chenthamarakshan

    2014-01-01

    Centriole duplication is the process by which two new daughter centrioles are generated from the proximal end of preexisting mother centrioles. Accurate centriole duplication is important for many cellular and physiological events, including cell division and ciliogenesis. Centrosomal protein 4.1-associated protein (CPAP), centrosomal protein of 152 kDa (CEP152), and centrobin are known to be essential for centriole duplication. However, the precise mechanism by which they contribute to centriole duplication is not known. In this study, we show that centrobin interacts with CEP152 and CPAP, and the centrobin-CPAP interaction is critical for centriole duplication. Although depletion of centrobin from cells did not have an effect on the centriolar levels of CEP152, it caused the disappearance of CPAP from both the preexisting and newly formed centrioles. Moreover, exogenous expression of the CPAP-binding fragment of centrobin also caused the disappearance of CPAP from both the preexisting and newly synthesized centrioles, possibly in a dominant negative manner, thereby inhibiting centriole duplication and the PLK4 overexpression-mediated centrosome amplification. Interestingly, exogenous overexpression of CPAP in the centrobin-depleted cells did not restore CPAP localization to the centrioles. However, restoration of centrobin expression in the centrobin-depleted cells led to the reappearance of centriolar CPAP. Hence, we conclude that centrobin-CPAP interaction is critical for the recruitment of CPAP to procentrioles to promote the elongation of daughter centrioles and for the persistence of CPAP on preexisting mother centrioles. Our study indicates that regulation of CPAP levels on the centrioles by centrobin is critical for preserving the normal size, shape, and number of centrioles in the cell. PMID:24700465

  4. Bone marrow-derived fibrocytes promote stem cell-like properties of lung cancer cells.

    Science.gov (United States)

    Saijo, Atsuro; Goto, Hisatsugu; Nakano, Mayuri; Mitsuhashi, Atsushi; Aono, Yoshinori; Hanibuchi, Masaki; Ogawa, Hirohisa; Uehara, Hisanori; Kondo, Kazuya; Nishioka, Yasuhiko

    2018-05-01

    Cancer stem cells (CSCs) represent a minor population that have clonal tumor initiation and self-renewal capacity and are responsible for tumor initiation, metastasis, and therapeutic resistance. CSCs reside in niches, which are composed of diverse types of stromal cells and extracellular matrix components. These stromal cells regulate CSC-like properties by providing secreted factors or by physical contact. Fibrocytes are differentiated from bone marrow-derived CD14 + monocytes and have features of both macrophages and fibroblasts. Accumulating evidence has suggested that stromal fibrocytes might promote cancer progression. However, the role of fibrocytes in the CSC niches has not been revealed. We herein report that human fibrocytes enhanced the CSC-like properties of lung cancer cells through secreted factors, including osteopontin, CC-chemokine ligand 18, and plasminogen activator inhibitor-1. The PIK3K/AKT pathway was critical for fibrocytes to mediate the CSC-like functions of lung cancer cells. In human lung cancer specimens, the number of tumor-infiltrated fibrocytes was correlated with high expression of CSC-associated protein in cancer cells. These results suggest that fibrocytes may be a novel cell population that regulates the CSC-like properties of lung cancer cells in the CSC niches. Copyright © 2018. Published by Elsevier B.V.

  5. Gastritis promotes an activated bone marrow-derived mesenchymal stem cell with a phenotype reminiscent of a cancer-promoting cell.

    Science.gov (United States)

    Donnelly, Jessica M; Engevik, Amy C; Engevik, Melinda; Schumacher, Michael A; Xiao, Chang; Yang, Li; Worrell, Roger T; Zavros, Yana

    2014-03-01

    Bone marrow-derived mesenchymal stem cells (BM-MSCs) promote gastric cancer in response to gastritis. In culture, BM-MSCs are prone to mutation with continued passage but it is unknown whether a similar process occurs in vivo in response to gastritis. The purpose of this study was to identify the role of chronic gastritis in the transformation of BM-MSCs leading to an activated cancer-promoting phenotype. Age matched C57BL/6 (BL/6) and gastrin deficient (GKO) mice were used for isolation of stomach, serum and mesenchymal stem cells (MSCs) at 3 and 6 months of age. MSC activation was assessed by growth curve analysis, fluorescence-activated cell sorting and xenograft assays. To allow for the isolation of bone marrow-derived stromal cells and assay in response to chronic gastritis, IRG/Vav-1(Cre) mice that expressed both enhanced green fluorescent protein-expressing hematopoietic cells and red fluorescent protein-expressing stromal cells were generated. In a parabiosis experiment, IRG/Vav-1(Cre) mice were paired to either an uninfected Vav-1(Cre) littermate or a BL/6 mouse inoculated with Helicobacter pylori. GKO mice displayed severe atrophic gastritis accompanied by elevated gastric tissue and circulating transforming growth factor beta (TGFβ) by 3 months of age. Compared to BM-MSCs isolated from uninflamed BL/6 mice, BM-MSCs isolated from GKO mice displayed an increased proliferative rate and elevated phosphorylated-Smad3 suggesting active TGFβ signaling. In xenograft assays, mice injected with BM-MSCs from 6-month-old GKO animals displayed tumor growth. RFP+ stromal cells were rapidly recruited to the gastric mucosa of H. pylori parabionts and exhibited changes in gene expression. Gastritis promotes the in vivo activation of BM-MSCs to a phenotype reminiscent of a cancer-promoting cell.

  6. Evaluation of novel inducible promoter/repressor systems for recombinant protein expression in Lactobacillus plantarum.

    Science.gov (United States)

    Heiss, Silvia; Hörmann, Angelika; Tauer, Christopher; Sonnleitner, Margot; Egger, Esther; Grabherr, Reingard; Heinl, Stefan

    2016-03-10

    Engineering lactic acid bacteria (LAB) is of growing importance for food and feed industry as well as for in vivo vaccination or the production of recombinant proteins in food grade organisms. Often, expression of a transgene is only desired at a certain time point or period, e.g. to minimize the metabolic burden for the host cell or to control the expression time span. For this purpose, inducible expression systems are preferred, though cost and availability of the inducing agent must be feasible. We selected the plasmid free strain Lactobacillus plantarum 3NSH for testing and characterization of novel inducible promoters/repressor systems. Their feasibility in recombinant protein production was evaluated. Expression of the reporter protein mCherry was monitored with the BioLector(®) micro-fermentation system. Reporter gene mCherry expression was compared under the control of different promoter/repressor systems: PlacA (an endogenous promoter/repressor system derived from L. plantarum 3NSH), PxylA (a promoter/repressor system derived from Bacillus megaterium DSMZ 319) and PlacSynth (synthetic promoter and codon-optimized repressor gene based on the Escherichia coli lac operon). We observed that PlacA was inducible solely by lactose, but not by non-metabolizable allolactose analoga. PxylA was inducible by xylose, yet showed basal expression under non-induced conditions. Growth on galactose (as compared to exponential growth phase on glucose) reduced basal mCherry expression at non-induced conditions. PlacSynth was inducible with TMG (methyl β-D-thiogalactopyranoside) and IPTG (isopropyl β-D-1-thiogalactopyranoside), but also showed basal expression without inducer. The promoter PlacSynth was used for establishment of a dual plasmid expression system, based on T7 RNA polymerase driven expression in L. plantarum. Comparative Western blot supported BioLector(®) micro-fermentation measurements. Conclusively, overall expression levels were moderate (compared to a

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

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  8. The mitochondrial outer membrane protein MDI promotes local protein synthesis and mtDNA replication.

    Science.gov (United States)

    Zhang, Yi; Chen, Yong; Gucek, Marjan; Xu, Hong

    2016-05-17

    Early embryonic development features rapid nuclear DNA replication cycles, but lacks mtDNA replication. To meet the high-energy demands of embryogenesis, mature oocytes are furnished with vast amounts of mitochondria and mtDNA However, the cellular machinery driving massive mtDNA replication in ovaries remains unknown. Here, we describe a Drosophila AKAP protein, MDI that recruits a translation stimulator, La-related protein (Larp), to the mitochondrial outer membrane in ovaries. The MDI-Larp complex promotes the synthesis of a subset of nuclear-encoded mitochondrial proteins by cytosolic ribosomes on the mitochondrial surface. MDI-Larp's targets include mtDNA replication factors, mitochondrial ribosomal proteins, and electron-transport chain subunits. Lack of MDI abolishes mtDNA replication in ovaries, which leads to mtDNA deficiency in mature eggs. Targeting Larp to the mitochondrial outer membrane independently of MDI restores local protein synthesis and rescues the phenotypes of mdi mutant flies. Our work suggests that a selective translational boost by the MDI-Larp complex on the outer mitochondrial membrane might be essential for mtDNA replication and mitochondrial biogenesis during oogenesis. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

  9. G-protein coupled receptor 56 promotes myoblast fusion through serum response factor- and nuclear factor of activated T-cell-mediated signalling but is not essential for muscle development in vivo.

    Science.gov (United States)

    Wu, Melissa P; Doyle, Jamie R; Barry, Brenda; Beauvais, Ariane; Rozkalne, Anete; Piao, Xianhua; Lawlor, Michael W; Kopin, Alan S; Walsh, Christopher A; Gussoni, Emanuela

    2013-12-01

    Mammalian muscle cell differentiation is a complex process of multiple steps for which many of the factors involved have not yet been defined. In a screen to identify the regulators of myogenic cell fusion, we found that the gene for G-protein coupled receptor 56 (GPR56) was transiently up-regulated during the early fusion of human myoblasts. Human mutations in the gene for GPR56 cause the disease bilateral frontoparietal polymicrogyria; however, the consequences of receptor dysfunction on muscle development have not been explored. Using knockout mice, we defined the role of GPR56 in skeletal muscle. GPR56(-/-) myoblasts have decreased fusion and smaller myotube sizes in culture. In addition, a loss of GPR56 expression in muscle cells results in decreases or delays in the expression of myogenic differentiation 1, myogenin and nuclear factor of activated T-cell (NFAT)c2. Our data suggest that these abnormalities result from decreased GPR56-mediated serum response element and NFAT signalling. Despite these changes, no overt differences in phenotype were identified in the muscle of GPR56 knockout mice, which presented only a mild but statistically significant elevation of serum creatine kinase compared to wild-type. In agreement with these findings, clinical data from 13 bilateral frontoparietal polymicrogyria patients revealed mild serum creatine kinase increase in only two patients. In summary, targeted disruption of GPR56 in mice results in myoblast abnormalities. The absence of a severe muscle phenotype in GPR56 knockout mice and human patients suggests that other factors may compensate for the lack of this G-protein coupled receptor during muscle development and that the motor delay observed in these patients is likely not a result of primary muscle abnormalities. © 2013 FEBS.

  10. β-Catenin promotes cell proliferation, migration, and invasion but induces apoptosis in renal cell carcinoma

    Directory of Open Access Journals (Sweden)

    Yang CM

    2017-02-01

    Full Text Available Chun-ming Yang,1 Shan Ji,2 Yan Li,3 Li-ye Fu,3 Tao Jiang,3 Fan-dong Meng31Department of Urology, The First Affiliated Hospital, China Medical University, 2Department of Endocrinology, The Fifth People’s Hospital of Shenyang, 3Department of Biotherapy, Cancer Research Institute, The First Affiliated Hospital, China Medical University, Shenyang, ChinaAbstract: β-Catenin (CTNNB1 gene coding protein is a component of the Wnt signaling pathway that has been shown to play an important role in the formation of certain cancers. Abnormal accumulation of CTNNB1 contributes to most cancers. This research studied the involvement of β-catenin in renal cell carcinoma (RCC cell proliferation, apoptosis, migration, and invasion. Proliferation, cell cycle, and apoptosis were analyzed by using Cell Counting Kit-8 and by flow cytometry. Migration and invasion assays were measured by transwell analysis. Real-time polymerase chain reaction and Western blot analysis were used to detect the expression of CTNNB1, ICAM-1, VCAM-1, CXCR4, and CCL18 in RCC cell lines. It was found that CTNNB1 knockdown inhibited cell proliferation, migration, and invasion and induced apoptosis of A-498 cells. CTNNB1 overexpression promoted cell proliferation, migration, and invasion and inhibited apoptosis of 786-O cells. Moreover, knockdown of CTNNB1 decreased the levels of ICAM-1, VCAM-1, CXCR4, and CCL18 expression, but CTNNB1 overexpression increased the expression of ICAM-1, VCAM-1, CXCR4, and CCL18. Further in vivo tumor formation study in nude mice indicated that inhibition of CTNNB1 delayed the progress of tumor formation through inhibiting PCNA and Ki67 expression. These results indicate that CTNNB1 could act as an oncogene and may serve as a promising therapeutic strategy for RCC.Keywords: kidney cancer, oncogene, β-catenin, survival time, tumor migration-related protein

  11. Cell penetrating peptides to dissect host-pathogen protein-protein interactions in Theileria -transformed leukocytes

    KAUST Repository

    Haidar, Malak; de Laté , Perle Latré ; Kennedy, Eileen J.; Langsley, Gordon

    2017-01-01

    One powerful application of cell penetrating peptides is the delivery into cells of molecules that function as specific competitors or inhibitors of protein-protein interactions. Ablating defined protein-protein interactions is a refined way

  12. Rhesus monkey neural stem cell transplantation promotes neural regeneration in rats with hippocampal lesions

    Directory of Open Access Journals (Sweden)

    Li-juan Ye

    2016-01-01

    Full Text Available Rhesus monkey neural stem cells are capable of differentiating into neurons and glial cells. Therefore, neural stem cell transplantation can be used to promote functional recovery of the nervous system. Rhesus monkey neural stem cells (1 × 105 cells/μL were injected into bilateral hippocampi of rats with hippocampal lesions. Confocal laser scanning microscopy demonstrated that green fluorescent protein-labeled transplanted cells survived and grew well. Transplanted cells were detected at the lesion site, but also in the nerve fiber-rich region of the cerebral cortex and corpus callosum. Some transplanted cells differentiated into neurons and glial cells clustering along the ventricular wall, and integrated into the recipient brain. Behavioral tests revealed that spatial learning and memory ability improved, indicating that rhesus monkey neural stem cells noticeably improve spatial learning and memory abilities in rats with hippocampal lesions.

  13. Adenovirus-mediated siRNA targeting TNF-α and overexpression of bone morphogenetic protein-2 promotes early osteoblast differentiation on a cell model of Ti particle-induced inflammatory response in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Guo, H.H.; Yu, C.C.; Sun, S.X. [Affiliated Hospital of Ningxia Medical University, Department of Orthopedic Surgery, Yinchuan (China); Ma, X.J. [Ningxia Medical Autonomous Region of the First People' s Hospital, Department of Orthopedic Surgery, Yinchuan (China); Yang, X.C.; Sun, K.N.; Jin, Q.H. [Affiliated Hospital of Ningxia Medical University, Department of Orthopedic Surgery, Yinchuan (China)

    2013-10-02

    Wear particles are phagocytosed by macrophages and other inflammatory cells, resulting in cellular activation and release of proinflammatory factors, which cause periprosthetic osteolysis and subsequent aseptic loosening, the most common causes of total joint arthroplasty failure. During this pathological process, tumor necrosis factor-alpha (TNF-α) plays an important role in wear-particle-induced osteolysis. In this study, recombination adenovirus (Ad) vectors carrying both target genes [TNF-α small interfering RNA (TNF-α-siRNA) and bone morphogenetic protein 2 (BMP-2)] were synthesized and transfected into RAW264.7 macrophages and pro-osteoblastic MC3T3-E1 cells, respectively. The target gene BMP-2, expressed on pro-osteoblastic MC3T3-E1 cells and silenced by the TNF-α gene on cells, was treated with titanium (Ti) particles that were assessed by real-time PCR and Western blot. We showed that recombinant adenovirus (Ad-siTNFα-BMP-2) can induce osteoblast differentiation when treated with conditioned medium (CM) containing RAW264.7 macrophages challenged with a combination of Ti particles and Ad-siTNFα-BMP-2 (Ti-ad CM) assessed by alkaline phosphatase activity. The receptor activator of nuclear factor-κB ligand was downregulated in pro-osteoblastic MC3T3-E1 cells treated with Ti-ad CM in comparison with conditioned medium of RAW264.7 macrophages challenged with Ti particles (Ti CM). We suggest that Ad-siTNFα-BMP-2 induced osteoblast differentiation and inhibited osteoclastogenesis on a cell model of a Ti particle-induced inflammatory response, which may provide a novel approach for the treatment of periprosthetic osteolysis.

  14. RPS27a promotes proliferation, regulates cell cycle progression and inhibits apoptosis of leukemia cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Houcai; Yu, Jing; Zhang, Lixia; Xiong, Yuanyuan; Chen, Shuying; Xing, Haiyan; Tian, Zheng; Tang, Kejing; Wei, Hui; Rao, Qing; Wang, Min; Wang, Jianxiang, E-mail: wangjx@ihcams.ac.cn

    2014-04-18

    Highlights: • RPS27a expression was up-regulated in advanced-phase CML and AL patients. • RPS27a knockdown changed biological property of K562 and K562/G01 cells. • RPS27a knockdown affected Raf/MEK/ERK, P21 and BCL-2 signaling pathways. • RPS27a knockdown may be applicable for new combination therapy in CML patients. - Abstract: Ribosomal protein S27a (RPS27a) could perform extra-ribosomal functions besides imparting a role in ribosome biogenesis and post-translational modifications of proteins. The high expression level of RPS27a was reported in solid tumors, and we found that the expression level of RPS27a was up-regulated in advanced-phase chronic myeloid leukemia (CML) and acute leukemia (AL) patients. In this study, we explored the function of RPS27a in leukemia cells by using CML cell line K562 cells and its imatinib resistant cell line K562/G01 cells. It was observed that the expression level of RPS27a was high in K562 cells and even higher in K562/G01 cells. Further analysis revealed that RPS27a knockdown by shRNA in both K562 and K562G01 cells inhibited the cell viability, induced cell cycle arrest at S and G2/M phases and increased cell apoptosis induced by imatinib. Combination of shRNA with imatinib treatment could lead to more cleaved PARP and cleaved caspase-3 expression in RPS27a knockdown cells. Further, it was found that phospho-ERK(p-ERK) and BCL-2 were down-regulated and P21 up-regulated in RPS27a knockdown cells. In conclusion, RPS27a promotes proliferation, regulates cell cycle progression and inhibits apoptosis of leukemia cells. It appears that drugs targeting RPS27a combining with tyrosine kinase inhibitor (TKI) might represent a novel therapy strategy in TKI resistant CML patients.

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  16. Promoter methylation inhibits BRD7 expression in human nasopharyngeal carcinoma cells

    International Nuclear Information System (INIS)

    Liu, Huaying; Li, Guiyuan; Zhang, Liming; Niu, Zhaoxia; Zhou, Ming; Peng, Cong; Li, Xiayu; Deng, Tan; Shi, Lei; Tan, Yixin

    2008-01-01

    Nasopharyngeal carcinoma (NPC) is a head and neck malignancy with high occurrence in South-East Asia and Southern China. Recent findings suggest that epigenetic inactivation of multiple tumor suppressor genes plays an important role in the tumourigenesis of NPC. BRD7 is a NPC-associated bromodomain gene that exhibits a much higher-level of mRNA expression in normal than in NPC biopsies and cell lines. In this study, we explored the role of DNA methylation in regulation of BRD7 transcription. The presence of CpG islands within BRD7 promoter was predicted by EMBOSS CpGplot and Softberry CpGFinder, respectively. Nested methylation-specific PCR and RT-PCR were employed to detect the methylation status of BRD7 promoter and the mRNA expression of BRD7 gene in tumor cell lines as well as clinical samples. Electrophoretic mobility shift assays (EMSA) and luciferase assay were used to detect the effects of cytosine methylation on the nuclear protein binding to BRD7 promoter. We found that DNA methylation suppresses BRD7 expression in NPC cells. In vitro DNA methylation in NPC cells silenced BRD7 promoter activity and inhibited the binding of the nuclear protein (possibly Sp1) to Sp1 binding sites in the BRD7 promoter. In contrast, inhibition of DNA methylation augments induction of endogenous BRD7 mRNA in NPC cells. We also found that methylation frequency of BRD7 promoter is much higher in the tumor and matched blood samples from NPC patients than in the blood samples from normal individuals. BRD7 promoter demethylation is a prerequisite for high level induction of BRD7 gene expression. DNA methylation of BRD7 promoter might serve as a diagnostic marker in NPC

  17. Activation of Wnt Planar Cell Polarity (PCP) signaling promotes growth plate column formation in vitro.

    Science.gov (United States)

    Randall, Rachel M; Shao, Yvonne Y; Wang, Lai; Ballock, R Tracy

    2012-12-01

    Disrupting the Wnt Planar Cell Polarity (PCP) signaling pathway in vivo results in loss of columnar growth plate architecture, but it is unknown whether activation of this pathway in vitro is sufficient to promote column formation. We hypothesized that activation of the Wnt PCP pathway in growth plate chondrocyte cell pellets would promote columnar organization in these cells that are normally oriented randomly in culture. Rat growth plate chondrocytes were transfected with plasmids encoding the Fzd7 cell-surface Wnt receptor, a Fzd7 deletion mutant lacking the Wnt-binding domain, or Wnt receptor-associated proteins Ror2 or Vangl2, and then cultured as three-dimensional cell pellets in the presence of recombinant Wnt5a or Wnt5b for 21 days. Cellular morphology was evaluated using histomorphometric measurements. Activation of Wnt PCP signaling components promoted the initiation of columnar morphogenesis in the chondrocyte pellet culture model, as measured by histomorphometric analysis of the column index (ANOVA p = 0.01). Activation of noncanonical Wnt signaling through overexpression of both the cell-surface Wnt receptor Fzd7 and receptor-associated protein Ror2 with addition of recombinant Wnt5a promotes the initiation of columnar architecture of growth plate chondrocytes in vitro, representing an important step toward growth plate regeneration. Copyright © 2012 Orthopaedic Research Society.

  18. Protein Kinase Mitogen-activated Protein Kinase Kinase Kinase Kinase 4 (MAP4K4) Promotes Obesity-induced Hyperinsulinemia.

    Science.gov (United States)

    Roth Flach, Rachel J; Danai, Laura V; DiStefano, Marina T; Kelly, Mark; Menendez, Lorena Garcia; Jurczyk, Agata; Sharma, Rohit B; Jung, Dae Young; Kim, Jong Hun; Kim, Jason K; Bortell, Rita; Alonso, Laura C; Czech, Michael P

    2016-07-29

    Previous studies revealed a paradox whereby mitogen-activated protein kinase kinase kinase kinase 4 (Map4k4) acted as a negative regulator of insulin sensitivity in chronically obese mice, yet systemic deletion of Map4k4 did not improve glucose tolerance. Here, we report markedly reduced glucose-responsive plasma insulin and C-peptide levels in whole body Map4k4-depleted mice (M4K4 iKO) as well as an impaired first phase of insulin secretion from islets derived from M4K4 iKO mice ex vivo After long-term high fat diet (HFD), M4K4 iKO mice pancreata also displayed reduced β cell mass, fewer proliferating β cells and reduced islet-specific gene mRNA expression compared with controls, although insulin content was normal. Interestingly, the reduced plasma insulin in M4K4 iKO mice exposed to chronic (16 weeks) HFD was not observed in response to acute HFD challenge or short term treatment with the insulin receptor antagonist S961. Furthermore, the improved insulin sensitivity in obese M4K4 iKO mice was abrogated by high exogenous insulin over the course of a euglycemic clamp study, indicating that hypoinsulinemia promotes insulin sensitivity in chronically obese M4K4 iKO mice. These results demonstrate that protein kinase Map4k4 drives obesity-induced hyperinsulinemia and insulin resistance in part by promoting insulin secretion from β cells in mice. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  19. Increasing Stem Cell Dose Promotes Posttransplant Immune Reconstitution.

    Science.gov (United States)

    Xu, Ning; Shen, Sylvie; Dolnikov, Alla

    2017-04-01

    Umbilical cord blood (UCB) transplantation can provide a successful therapeutic option for patients that have no suitable related donor. UCB transplantation is often limited by the relatively small hematopoietic stem cell (HSC) numbers in UCB especially for adult recipients. Early neutrophil and platelet engraftment correlates with the stem cell numbers in UCB transplant. Compared to other HSC sources, immune reconstitution following UCB transplant is slower and complicated by increased frequency of opportunistic infections. The effect of HSC numbers in UCB transplant on immune reconstitution was not thoroughly examined. Using immunocompromised mice transplanted with purified UCB CD34+ stem cells, we have demonstrated that increasing the numbers of CD34+ cells in the transplant promotes hematopoietic and immune reconstitution. At early stages posttransplant, high stem cell dose generated relatively more B cells, while lower dose generated more myeloid and T cells. Thus, the size of the stem cell graft appears to modulate the differentiation potential of infused stem cells. In addition, increasing stem cell dose in the transplant improved CD8+ T cell development and delayed late memory T cell skewing in expense of naive T cells highlighting the importance of HSC dose to maintain the pool of naive T cells able to develop strong immune responses. Transplantation of ex vivo expanded CD34+ cells did not promote, but rather delayed immune reconstitution suggesting the loss of primitive lymphoid precursor cells during ex vivo expansion.

  20. ASIC PROTEINS REGULATE SMOOTH MUSCLE CELL MIGRATION

    OpenAIRE

    Grifoni, Samira C.; Jernigan, Nikki L.; Hamilton, Gina; Drummond, Heather A.

    2007-01-01

    The purpose of the present study was to investigate Acid Sensing Ion Channel (ASIC) protein expression and importance in cellular migration. We recently demonstrated Epithelial Na+ Channel (ENaC) proteins are required for vascular smooth muscle cell (VSMC) migration, however the role of the closely related ASIC proteins has not been addressed. We used RT-PCR and immunolabeling to determine expression of ASIC1, ASIC2, ASIC3 and ASIC4 in A10 cells. We used small interference RNA to silence indi...

  1. Epigenetic Silencing of CXCR4 Promotes Loss of Cell Adhesion in Cervical Cancer

    Directory of Open Access Journals (Sweden)

    Suresh Singh Yadav

    2014-01-01

    Full Text Available In the network of chemokine signaling pathways, recent reports have described the SDF-1α/CXCR4 axis and its role in cancer progression and metastasis. Interestingly, we found downregulation of CXCR4 at both transcript and protein level in cervical cancer cell lines and primary tumors. We also found CXCR4 promoter hypermethylation in cervical cancer cell lines and primary biopsy samples. DNA hypomethylating drug 5-AZA-2′-deoxycytidine and histone deacetylase inhibitor Trichostatin A treatments in cell lines reactivate both CXCR4 transcription and protein expression. Cell adhesion assay demonstrated that autocrine SDF-1α promotes the loss of cell adhesion while paracrine SDF-1α predominantly protects the normal cervical cells from loss of cell adhesion. Cervical cancer cell line C-33A having increased expression of CXCR4 after TSA treatment showed increased cell adhesion by paracrine source of SDF-1α in comparison to untreated C-33A. These findings demonstrate the first evidence that epigenetic silencing of CXCR4 makes the cells inefficient to respond to the paracrine source of SDF-1α leading to loss of cell adhesion, one of the key events in metastases and progression of the disease. Our results provide novel insight of SDF-1α/CXCR4 signaling in tumor microenvironment which may be promising to further delineate molecular mechanism of cervical carcinogenesis.

  2. BRK targets Dok1 for ubiquitin-mediated proteasomal degradation to promote cell proliferation and migration.

    Directory of Open Access Journals (Sweden)

    Sayem Miah

    Full Text Available Breast tumor kinase (BRK, also known as protein tyrosine kinase 6 (PTK6, is a non-receptor tyrosine kinase overexpressed in more that 60% of human breast carcinomas. The overexpression of BRK has been shown to sensitize mammary epithelial cells to mitogenic signaling and to promote cell proliferation and tumor formation. The molecular mechanisms of BRK have been unveiled by the identification and characterization of BRK target proteins. Downstream of tyrosine kinases 1 or Dok1 is a scaffolding protein and a substrate of several tyrosine kinases. Herein we show that BRK interacts with and phosphorylates Dok1 specifically on Y362. We demonstrate that this phosphorylation by BRK significantly downregulates Dok1 in a ubiquitin-proteasome-mediated mechanism. Together, these results suggest a novel mechanism of action of BRK in the promotion of tumor formation, which involves the targeting of tumor suppressor Dok1 for degradation through the ubiquitin proteasomal pathway.

  3. BRK targets Dok1 for ubiquitin-mediated proteasomal degradation to promote cell proliferation and migration.

    Science.gov (United States)

    Miah, Sayem; Goel, Raghuveera Kumar; Dai, Chenlu; Kalra, Natasha; Beaton-Brown, Erika; Bagu, Edward T; Bonham, Keith; Lukong, Kiven E

    2014-01-01

    Breast tumor kinase (BRK), also known as protein tyrosine kinase 6 (PTK6), is a non-receptor tyrosine kinase overexpressed in more that 60% of human breast carcinomas. The overexpression of BRK has been shown to sensitize mammary epithelial cells to mitogenic signaling and to promote cell proliferation and tumor formation. The molecular mechanisms of BRK have been unveiled by the identification and characterization of BRK target proteins. Downstream of tyrosine kinases 1 or Dok1 is a scaffolding protein and a substrate of several tyrosine kinases. Herein we show that BRK interacts with and phosphorylates Dok1 specifically on Y362. We demonstrate that this phosphorylation by BRK significantly downregulates Dok1 in a ubiquitin-proteasome-mediated mechanism. Together, these results suggest a novel mechanism of action of BRK in the promotion of tumor formation, which involves the targeting of tumor suppressor Dok1 for degradation through the ubiquitin proteasomal pathway.

  4. The Effect of Salts in Promoting Specific and Competitive Interactions between Zinc Finger Proteins and Metals

    Science.gov (United States)

    Li, Gongyu; Yuan, Siming; Zheng, Shihui; Chen, Yuting; Zheng, Zhen; Liu, Yangzhong; Huang, Guangming

    2017-12-01

    Specific protein-metal interactions (PMIs) fulfill essential functions in cells and organic bodies, and activation of these functions in vivo are mostly modulated by the complex environmental factors, including pH value, small biomolecules, and salts. Specifically, the role of salts in promoting specific PMIs and their competition among various metals has remained untapped mainly due to the difficulty to distinguish nonspecific PMIs from specific PMIs by classic spectroscopic techniques. Herein, we report Hofmeister salts differentially promote the specific PMIs by combining nanoelectrospray ionization mass spectrometry and spectroscopic techniques (fluorescence measurement and circular dichroism). Furthermore, to explore the influence of salts in competitive binding between metalloproteins and various metals, we designed a series of competitive experiments and applied to a well-defined model system, the competitive binding of zinc (II) and arsenic (III) to holo-promyelocytic leukemia protein (PML). These experiments not only provided new insights at the molecular scale as complementary to previous NMR and spectroscopic results, but also deduced the relative binding ability between zinc finger proteins and metals at the molecular scale, which avoids the mass spectrometric titration-based determination of binding constants that is frequently affected and often degraded by variable solution conditions including salt contents. [Figure not available: see fulltext.

  5. DNA cytosine methylation in the bovine leukemia virus promoter is associated with latency in a lymphoma-derived B-cell line: potential involvement of direct inhibition of cAMP-responsive element (CRE)-binding protein/CRE modulator/activation transcription factor binding.

    Science.gov (United States)

    Pierard, Valérie; Guiguen, Allan; Colin, Laurence; Wijmeersch, Gaëlle; Vanhulle, Caroline; Van Driessche, Benoît; Dekoninck, Ann; Blazkova, Jana; Cardona, Christelle; Merimi, Makram; Vierendeel, Valérie; Calomme, Claire; Nguyên, Thi Liên-Anh; Nuttinck, Michèle; Twizere, Jean-Claude; Kettmann, Richard; Portetelle, Daniel; Burny, Arsène; Hirsch, Ivan; Rohr, Olivier; Van Lint, Carine

    2010-06-18

    Bovine leukemia virus (BLV) proviral latency represents a viral strategy to escape the host immune system and allow tumor development. Besides the previously demonstrated role of histone deacetylation in the epigenetic repression of BLV expression, we showed here that BLV promoter activity was induced by several DNA methylation inhibitors (such as 5-aza-2'-deoxycytidine) and that overexpressed DNMT1 and DNMT3A, but not DNMT3B, down-regulated BLV promoter activity. Importantly, cytosine hypermethylation in the 5'-long terminal repeat (LTR) U3 and R regions was associated with true latency in the lymphoma-derived B-cell line L267 but not with defective latency in YR2 cells. Moreover, the virus-encoded transactivator Tax(BLV) decreased DNA methyltransferase expression levels, which could explain the lower level of cytosine methylation observed in the L267(LTaxSN) 5'-LTR compared with the L267 5'-LTR. Interestingly, DNA methylation inhibitors and Tax(BLV) synergistically activated BLV promoter transcriptional activity in a cAMP-responsive element (CRE)-dependent manner. Mechanistically, methylation at the -154 or -129 CpG position (relative to the transcription start site) impaired in vitro binding of CRE-binding protein (CREB) transcription factors to their respective CRE sites. Methylation at -129 CpG alone was sufficient to decrease BLV promoter-driven reporter gene expression by 2-fold. We demonstrated in vivo the recruitment of CREB/CRE modulator (CREM) and to a lesser extent activating transcription factor-1 (ATF-1) to the hypomethylated CRE region of the YR2 5'-LTR, whereas we detected no CREB/CREM/ATF recruitment to the hypermethylated corresponding region in the L267 cells. Altogether, these findings suggest that site-specific DNA methylation of the BLV promoter represses viral transcription by directly inhibiting transcription factor binding, thereby contributing to true proviral latency.

  6. Collagen Promotes Higher Adhesion, Survival and Proliferation of Mesenchymal Stem Cells.

    Directory of Open Access Journals (Sweden)

    Chinnapaka Somaiah

    Full Text Available Mesenchymal stem cells (MSC can differentiate into several cell types and are desirable candidates for cell therapy and tissue engineering. However, due to poor cell survival, proliferation and differentiation in the patient, the therapy outcomes have not been satisfactory. Although several studies have been done to understand the conditions that promote proliferation, differentiation and migration of MSC in vitro and in vivo, still there is no clear understanding on the effect of non-cellular bio molecules. Of the many factors that influence the cell behavior, the immediate cell microenvironment plays a major role. In this context, we studied the effect of extracellular matrix (ECM proteins in controlling cell survival, proliferation, migration and directed MSC differentiation. We found that collagen promoted cell proliferation, cell survival under stress and promoted high cell adhesion to the cell culture surface. Increased osteogenic differentiation accompanied by high active RHOA (Ras homology gene family member A levels was exhibited by MSC cultured on collagen. In conclusion, our study shows that collagen will be a suitable matrix for large scale production of MSC with high survival rate and to obtain high osteogenic differentiation for therapy.

  7. Origins of Protein Functions in Cells

    Science.gov (United States)

    Seelig, Burchard; Pohorille, Andrzej

    2011-01-01

    In modern organisms proteins perform a majority of cellular functions, such as chemical catalysis, energy transduction and transport of material across cell walls. Although great strides have been made towards understanding protein evolution, a meaningful extrapolation from contemporary proteins to their earliest ancestors is virtually impossible. In an alternative approach, the origin of water-soluble proteins was probed through the synthesis and in vitro evolution of very large libraries of random amino acid sequences. In combination with computer modeling and simulations, these experiments allow us to address a number of fundamental questions about the origins of proteins. Can functionality emerge from random sequences of proteins? How did the initial repertoire of functional proteins diversify to facilitate new functions? Did this diversification proceed primarily through drawing novel functionalities from random sequences or through evolution of already existing proto-enzymes? Did protein evolution start from a pool of proteins defined by a frozen accident and other collections of proteins could start a different evolutionary pathway? Although we do not have definitive answers to these questions yet, important clues have been uncovered. In one example (Keefe and Szostak, 2001), novel ATP binding proteins were identified that appear to be unrelated in both sequence and structure to any known ATP binding proteins. One of these proteins was subsequently redesigned computationally to bind GTP through introducing several mutations that introduce targeted structural changes to the protein, improve its binding to guanine and prevent water from accessing the active center. This study facilitates further investigations of individual evolutionary steps that lead to a change of function in primordial proteins. In a second study (Seelig and Szostak, 2007), novel enzymes were generated that can join two pieces of RNA in a reaction for which no natural enzymes are known

  8. Protein kinase C (PKC) isoforms in cancer, tumor promotion and tumor suppression.

    Science.gov (United States)

    Isakov, Noah

    2018-02-01

    The AGC family of serine/threonine kinases (PKA, PKG, PKC) includes more than 60 members that are critical regulators of numerous cellular functions, including cell cycle and differentiation, morphogenesis, and cell survival and death. Mutation and/or dysregulation of AGC kinases can lead to malignant cell transformation and contribute to the pathogenesis of many human diseases. Members of one subgroup of AGC kinases, the protein kinase C (PKC), have been singled out as critical players in carcinogenesis, following their identification as the intracellular receptors of phorbol esters, which exhibit tumor-promoting activities. This observation attracted the attention of researchers worldwide and led to intense investigations on the role of PKC in cell transformation and the potential use of PKC as therapeutic drug targets in cancer diseases. Studies demonstrated that many cancers had altered expression and/or mutation of specific PKC genes. However, the causal relationships between the changes in PKC gene expression and/or mutation and the direct cause of cancer remain elusive. Independent studies in normal cells demonstrated that activation of PKC is essential for the induction of cell activation and proliferation, differentiation, motility, and survival. Based on these observations and the general assumption that PKC isoforms play a positive role in cell transformation and/or cancer progression, many PKC inhibitors have entered clinical trials but the numerous attempts to target PKC in cancer has so far yielded only very limited success. More recent studies demonstrated that PKC function as tumor suppressors, and suggested that future clinical efforts should focus on restoring, rather than inhibiting, PKC activity. The present manuscript provides some historical perspectives on the tumor promoting function of PKC, reviewing some of the observations linking PKC to cancer progression, and discusses the role of PKC in the pathogenesis of cancer diseases and its

  9. Protein phosphatase 5 promotes hepatocarcinogenesis through interaction with AMP-activated protein kinase.

    Science.gov (United States)

    Chen, Yao-Li; Hung, Man-Hsin; Chu, Pei-Yi; Chao, Tzu-I; Tsai, Ming-Hsien; Chen, Li-Ju; Hsiao, Yung-Jen; Shih, Chih-Ting; Hsieh, Feng-Shu; Chen, Kuen-Feng

    2017-08-15

    The serine-threonine protein phosphatase family members are known as critical regulators of various cellular functions, such as survival and transformation. Growing evidence suggests that pharmacological manipulation of phosphatase activity exhibits therapeutic benefits. Ser/Thr protein phosphatase 5 (PP5) is known to participate in glucocorticoid receptor (GR) and stress-induced signaling cascades that regulate cell growth and apoptosis, and has been shown to be overexpressed in various human malignant diseases. However, the role of PP5 in hepatocellular carcinoma (HCC) and whether PP5 may be a viable therapeutic target for HCC treatment are unknown. Here, by analyzing HCC clinical samples obtained from 215 patients, we found that overexpression of PP5 is tumor specific and associated with worse clinical outcomes. We further characterized the oncogenic properties of PP5 in HCC cells. Importantly, both silencing of PP5 with lentiviral-mediated short hairpin RNA (shRNA) and chemical inhibition of PP5 phosphatase activity using the natural compound cantharidin/norcantharidin markedly suppressed the growth of HCC cells and tumors in vitro and in vivo. Moreover, we identified AMP-activated protein kinase (AMPK) as a novel downstream target of oncogenic PP5 and demonstrated that the antitumor mechanisms underlying PP5 inhibition involve activation of AMPK signaling. Overall, our results establish a pathological function of PP5 in hepatocarcinogenesis via affecting AMPK signaling and suggest that PP5 inhibition is an attractive therapeutic approach for HCC. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. PRELP (proline/arginine-rich end leucine-rich repeat protein) promotes osteoblastic differentiation of preosteoblastic MC3T3-E1 cells by regulating the β-catenin pathway

    Energy Technology Data Exchange (ETDEWEB)

    Li, Haiying; Cui, Yazhou; Luan, Jing [School of Medicine and Life Sciences, University of Jinan-Shandong Academy of Medical Science, Ji' nan, Shandong (China); Key Laboratory for Rare Disease Research of Shandong Province, Key Laboratory for Biotech Drugs of the Ministry of Health, Shandong Medical Biotechnological Center, Shandong Academy of Medical Sciences, Ji' nan, Shandong (China); Zhang, Xiumei [School of Medicine and Life Sciences, University of Jinan-Shandong Academy of Medical Science, Ji' nan, Shandong (China); Li, Chengzhi; Zhou, Xiaoyan; Shi, Liang [School of Medicine and Life Sciences, University of Jinan-Shandong Academy of Medical Science, Ji' nan, Shandong (China); Key Laboratory for Rare Disease Research of Shandong Province, Key Laboratory for Biotech Drugs of the Ministry of Health, Shandong Medical Biotechnological Center, Shandong Academy of Medical Sciences, Ji' nan, Shandong (China); Wang, Huaxin [Shandong University of Traditional Chinese Medicine, Ji' an, Shandong (China); Han, Jinxiang, E-mail: jxhan9888@aliyun.com [School of Medicine and Life Sciences, University of Jinan-Shandong Academy of Medical Science, Ji' nan, Shandong (China); Key Laboratory for Rare Disease Research of Shandong Province, Key Laboratory for Biotech Drugs of the Ministry of Health, Shandong Medical Biotechnological Center, Shandong Academy of Medical Sciences, Ji' nan, Shandong (China)

    2016-02-12

    Proline/arginine-rich end leucine-rich repeat protein (PRELP) is a collagen-binding proteoglycan highly expressed in the developing bones. Recent studies indicated that PRELP could inhibit osteoclastogenesis as a NF-κB inhibitor. However, its role during osteoblast differentiation is still unclear. In this study, we confirmed that the expression of PRELP increased with the osteogenesis induction of preosteoblastic MC3T3-E1 cells. Down-regulation of PRELP expression by shRNA reduced ALP activity, mineralization and expression of osteogenic marker gene Runx2. Our microarray analysis data suggested that β-catenin may act as a hub gene in the PRELP-mediated gene network. We validated furtherly that PRELP knockdown could inhibit the level of connexin43, a key regulator of osteoblast differentiation by affecting β-catenin protein expression, and its nuclear translocation in MC3T3-E1 preosteoblasts. Therefore, this study established a new role of PRELP in modulating β-catenin/connexin43 pathway and osteoblast differentiation.

  11. Yes-Associated Protein (YAP) Promotes the Nuclear Import of p73

    International Nuclear Information System (INIS)

    Zhang Heng; Wu Shengnan

    2011-01-01

    p73 has been identified as a structural and functional homolog of the tumor suppressor p53. However, mechanisms that regulate the localization of p73 have not been fully clarified. The Yes-associated protein (YAP) is a transcriptional coactivator. As a transcriptional coactivator, YAP needs to bind transcription factors to stimulate gene expression. p73 is a reported YAP target transcription factors and YAP has been shown to positively regulate p73 in promoting apoptosis. Previous studies show that p73 interacts with YAP through its PPPY motif, and increases p73 transactivation of apoptotic genes. In this study, we focused on YAP's regulation of the localization of p73. After transient transfection into Rat pheochromocytoma (PC12) cells and Human embryonic kidney 293T cells with GFP-YAP and/or YFP-p73, and incubated for 24 hours expression. p73 was fused to YFP to allow the examination of its subcellular localization. When expressed alone, YFP-p73 was distributed throughout the cell. When coexpressed with YAP, nuclear accumulation of YFP-p73 became evident. We quantitated the effect of YAP on the redistribution of YFP-p73 by counting cells with nuclear-only YFP signal. We found that YAP can influence the subcellular distribution of p73. Altogether, coexpression with YAP affected the subcellular distribution of the p73 protein. Our studies attribute a central role to YAP in regulating p73 accumulation and YAP, at least in part, might promote the nuclear import of p73.

  12. A single cysteine post-translational oxidation suffices to compromise globular proteins kinetic stability and promote amyloid formation

    Directory of Open Access Journals (Sweden)

    Patrizia Marinelli

    2018-04-01

    Full Text Available Oxidatively modified forms of proteins accumulate during aging. Oxidized protein conformers might act as intermediates in the formation of amyloids in age-related disorders. However, it is not known whether this amyloidogenic conversion requires an extensive protein oxidative damage or it can be promoted just by a discrete, localized post-translational modification of certain residues. Here, we demonstrate that the irreversible oxidation of a single free Cys suffices to severely perturb the folding energy landscape of a stable globular protein, compromise its kinetic stability, and lead to the formation of amyloids under physiological conditions. Experiments and simulations converge to indicate that this specific oxidation-promoted protein aggregation requires only local unfolding. Indeed, a large scale analysis indicates that many cellular proteins are at risk of undergoing this kind of deleterious transition; explaining how oxidative stress can impact cell proteostasis and subsequently lead to the onset of pathological states. Keywords: Protein oxidation, Protein misfolding, Protein aggregation, Oxidative stress, Post-translational modification

  13. TH17 cells promote microbial killing and innate immune sensing of DNA via interleukin 26

    KAUST Repository

    Meller, Stephan; Di Domizio, Jeremy; Voo, Kui S; Friedrich, Heike C; Chamilos, Georgios; Ganguly, Dipyaman; Conrad, Curdin; Gregorio, Josh; Le Roy, Didier; Roger, Thierry; Ladbury, John E; Homey, Bernhard; Watowich, Stanley; Modlin, Robert L; Kontoyiannis, Dimitrios P; Liu, Yong-Jun; Arold, Stefan T.; Gilliet, Michel

    2015-01-01

    Interleukin 17-producing helper T cells (TH 17 cells) have a major role in protection against infections and in mediating autoimmune diseases, yet the mechanisms involved are incompletely understood. We found that interleukin 26 (IL-26), a human TH17 cell-derived cytokine, is a cationic amphipathic protein that kills extracellular bacteria via membrane-pore formation. Furthermore, TH17 cell-derived IL-26 formed complexes with bacterial DNA and self-DNA released by dying bacteria and host cells. The resulting IL-26-DNA complexes triggered the production of type I interferon by plasmacytoid dendritic cells via activation of Toll-like receptor 9, but independently of the IL-26 receptor. These findings provide insights into the potent antimicrobial and proinflammatory function of TH17 cells by showing that IL-26 is a natural human antimicrobial that promotes immune sensing of bacterial and host cell death. © 2015 Nature America, Inc.

  14. TH17 cells promote microbial killing and innate immune sensing of DNA via interleukin 26

    KAUST Repository

    Meller, Stephan

    2015-07-13

    Interleukin 17-producing helper T cells (TH 17 cells) have a major role in protection against infections and in mediating autoimmune diseases, yet the mechanisms involved are incompletely understood. We found that interleukin 26 (IL-26), a human TH17 cell-derived cytokine, is a cationic amphipathic protein that kills extracellular bacteria via membrane-pore formation. Furthermore, TH17 cell-derived IL-26 formed complexes with bacterial DNA and self-DNA released by dying bacteria and host cells. The resulting IL-26-DNA complexes triggered the production of type I interferon by plasmacytoid dendritic cells via activation of Toll-like receptor 9, but independently of the IL-26 receptor. These findings provide insights into the potent antimicrobial and proinflammatory function of TH17 cells by showing that IL-26 is a natural human antimicrobial that promotes immune sensing of bacterial and host cell death. © 2015 Nature America, Inc.

  15. Protein carbonylation, protein aggregation and neuronal cell death in a murine model of multiple sclerosis

    Science.gov (United States)

    Dasgupta, Anushka

    Many studies have suggested that oxidative stress plays an important role in the pathophysiology of both multiple sclerosis (MS) and its animal model experimental autoimmune encephalomyelitis (EAE). Yet, the mechanism by which oxidative stress leads to tissue damage in these disorders is unclear. Recent work from our laboratory has revealed that protein carbonylation, a major oxidative modification caused by severe and/or chronic oxidative stress conditions, is elevated in MS and EAE. Furthermore, protein carbonylation has been shown to alter protein structure leading to misfolding/aggregation. These findings prompted me to hypothesize that carbonylated proteins, formed as a consequence of oxidative stress and/or decreased proteasomal activity, promote protein aggregation to mediate neuronal apoptosis in vitro and in EAE. To test this novel hypothesis, I first characterized protein carbonylation, protein aggregation and apoptosis along the spinal cord during the course of myelin-oligodendrocyte glycoprotein (MOG)35-55 peptide-induced EAE in C57BL/6 mice [Chapter 2]. The results show that carbonylated proteins accumulate throughout the course of the disease, albeit by different mechanisms: increased oxidative stress in acute EAE and decreased proteasomal activity in chronic EAE. I discovered not only that there is a temporal correlation between protein carbonylation and apoptosis but also that carbonyl levels are significantly higher in apoptotic cells. A high number of juxta-nuclear and cytoplasmic protein aggregates containing the majority of the oxidized proteins are also present during the course of EAE, which seems to be due to reduced autophagy. In chapter 3, I show that when gluthathione levels are reduced to those in EAE spinal cord, both neuron-like PC12 (nPC12) cells and primary neuronal cultures accumulate carbonylated proteins and undergo cell death (both by necrosis and apoptosis). Immunocytochemical and biochemical studies also revealed a temporal

  16. Human Nanog pseudogene8 promotes the proliferation of gastrointestinal cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Uchino, Keita, E-mail: uchino13@intmed1.med.kyushu-u.ac.jp [Department of Medicine and Biosystemic Science, Kyushu University Graduate School of Medical Sciences, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan); Hirano, Gen [Department of Medicine and Biosystemic Science, Kyushu University Graduate School of Medical Sciences, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan); Hirahashi, Minako [Department of Anatomic Pathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan); Isobe, Taichi; Shirakawa, Tsuyoshi; Kusaba, Hitoshi; Baba, Eishi [Department of Medicine and Biosystemic Science, Kyushu University Graduate School of Medical Sciences, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan); Tsuneyoshi, Masazumi [Department of Anatomic Pathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan); Akashi, Koichi [Department of Medicine and Biosystemic Science, Kyushu University Graduate School of Medical Sciences, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan)

    2012-09-10

    There is emerging evidence that human solid tumor cells originate from cancer stem cells (CSCs). In cancer cell lines, tumor-initiating CSCs are mainly found in the side population (SP) that has the capacity to extrude dyes such as Hoechst 33342. We found that Nanog is expressed specifically in SP cells of human gastrointestinal (GI) cancer cells. Nucleotide sequencing revealed that NanogP8 but not Nanog was expressed in GI cancer cells. Transfection of NanogP8 into GI cancer cell lines promoted cell proliferation, while its inhibition by anti-Nanog siRNA suppressed the proliferation. Immunohistochemical staining of primary GI cancer tissues revealed NanogP8 protein to be strongly expressed in 3 out of 60 cases. In these cases, NanogP8 was found especially in an infiltrative part of the tumor, in proliferating cells with Ki67 expression. These data suggest that NanogP8 is involved in GI cancer development in a fraction of patients, in whom it presumably acts by supporting CSC proliferation. -- Highlights: Black-Right-Pointing-Pointer Nanog maintains pluripotency by regulating embryonic stem cells differentiation. Black-Right-Pointing-Pointer Nanog is expressed in cancer stem cells of human gastrointestinal cancer cells. Black-Right-Pointing-Pointer Nucleotide sequencing revealed that Nanog pseudogene8 but not Nanog was expressed. Black-Right-Pointing-Pointer Nanog pseudogene8 promotes cancer stem cells proliferation. Black-Right-Pointing-Pointer Nanog pseudogene8 is involved in gastrointestinal cancer development.

  17. Human Nanog pseudogene8 promotes the proliferation of gastrointestinal cancer cells

    International Nuclear Information System (INIS)

    Uchino, Keita; Hirano, Gen; Hirahashi, Minako; Isobe, Taichi; Shirakawa, Tsuyoshi; Kusaba, Hitoshi; Baba, Eishi; Tsuneyoshi, Masazumi; Akashi, Koichi

    2012-01-01

    There is emerging evidence that human solid tumor cells originate from cancer stem cells (CSCs). In cancer cell lines, tumor-initiating CSCs are mainly found in the side population (SP) that has the capacity to extrude dyes such as Hoechst 33342. We found that Nanog is expressed specifically in SP cells of human gastrointestinal (GI) cancer cells. Nucleotide sequencing revealed that NanogP8 but not Nanog was expressed in GI cancer cells. Transfection of NanogP8 into GI cancer cell lines promoted cell proliferation, while its inhibition by anti-Nanog siRNA suppressed the proliferation. Immunohistochemical staining of primary GI cancer tissues revealed NanogP8 protein to be strongly expressed in 3 out of 60 cases. In these cases, NanogP8 was found especially in an infiltrative part of the tumor, in proliferating cells with Ki67 expression. These data suggest that NanogP8 is involved in GI cancer development in a fraction of patients, in whom it presumably acts by supporting CSC proliferation. -- Highlights: ► Nanog maintains pluripotency by regulating embryonic stem cells differentiation. ► Nanog is expressed in cancer stem cells of human gastrointestinal cancer cells. ► Nucleotide sequencing revealed that Nanog pseudogene8 but not Nanog was expressed. ► Nanog pseudogene8 promotes cancer stem cells proliferation. ► Nanog pseudogene8 is involved in gastrointestinal cancer development.

  18. Invited review: Whey proteins as antioxidants and promoters of cellular antioxidant pathways.

    Science.gov (United States)

    Corrochano, Alberto R; Buckin, Vitaly; Kelly, Phil M; Giblin, Linda

    2018-03-28

    Oxidative stress contributes to cell injury and aggravates several chronic diseases. Dietary antioxidants help the body to fight against free radicals and, therefore, avoid or reduce oxidative stress. Recently, proteins from milk whey liquid have been described as antioxidants. This review summarizes the evidence that whey products exhibit radical scavenging activity and reducing power. It examines the processing and treatment attempts to increase the antioxidant bioactivity and identifies 1 enzyme, subtilisin, which consistently produces the most potent whey fractions. The review compares whey from different milk sources and puts whey proteins in the context of other known food antioxidants. However, for efficacy, the antioxidant activity of whey proteins must not only survive processing, but also upper gut transit and arrival in the bloodstream, if whey products are to promote antioxidant levels in target organs. Studies reveal that direct cell exposure to whey samples increases intracellular antioxidants such as glutathione. However, the physiological relevance of these in vitro assays is questionable, and evidence is conflicting from dietary intervention trials, with both rats and humans, that whey products can boost cellular antioxidant biomarkers. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  19. Secreted Frizzled related protein-4 (sFRP4) promotes epidermal differentiation and apoptosis

    International Nuclear Information System (INIS)

    Maganga, Richard; Giles, Natalie; Adcroft, Katharine; Unni, Ambili; Keeney, Diane; Wood, Fiona; Fear, Mark; Dharmarajan, Arunasalam

    2008-01-01

    The skin provides vital protection from infection and dehydration. Maintenance of the skin is through a constant program of proliferation, differentiation and apoptosis of epidermal cells, whereby proliferating cells in the basal layer differentiating to form the keratinized, anucleated stratum corneum. The WNT signalling pathway is known to be important in the skin. WNT signalling has been shown to be important both in epidermal development and in the maintenance and cycling of hair follicles and epidermal stem cells. However, the precise role for this pathway in epidermal differentiation remains unknown. We investigated the role of the WNT signalling inhibitor sFRP4 in epidermal differentiation. sFRP4 is expressed in both normal skin and keratinocytes in culture. Expression of sFRP4 mRNA and protein increases with keratinocyte differentiation and apoptosis, whilst exposure of keratinocytes to exogenous sFRP4 promotes apoptosis and expression of the terminal differentiation marker Involucrin. These data suggest sFRP4 promotes epidermal differentiation.

  20. miR-367 promotes proliferation and invasion of hepatocellular carcinoma cells by negatively regulating PTEN

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Xiangrui, E-mail: mengxiangruibb2008@163.com [Oncology Department, The First Affiliated Hospital of Zhengzhou University, Zhengzhou (China); Lu, Peng [Gastrointestinal Surgery Department, People' s Hospital of Zhengzhou, Zhengzhou (China); Fan, Qingxia [Oncology Department, The First Affiliated Hospital of Zhengzhou University, Zhengzhou (China)

    2016-01-29

    MicroRNAs play important roles in the carcinogenesis of many types of cancers by inhibiting gene expression at posttranscriptional level. However, the roles of microRNAs in hepatocellular carcinoma, are still unclear. Here, we identified that miR-367 promotes hepatocellular carcinoma (HCC) cell proliferation by negatively regulates its target gene PTEN. The expression of miR-367 and PTEN are significantly inverse correlated in 35 HCC patients. In HCC cell line, CCK-8 proliferation assay indicated that the cell proliferation was promoted by miR-367, while miR-367 inhibitor significantly inhibited the cell proliferation. Transwell assay showed that miR-367 mimics significantly promoted the migration and invasion of HCC cells, whereas miR-367 inhibitors significantly reduced cell migration and invasion. Luciferase assays confirmed that miR-367 directly bound to the 3'untranslated region of PTEN, and western blotting showed that miR-367 suppressed the expression of PTEN at the protein levels. This study indicated that miR-367 negatively regulates PTEN and promotes proliferation and invasion of HCC cells. Thus, miR-367 may represent a potential therapeutic target for HCC intervention. - Highlights: • miR-367 mimics promote the proliferation and invasion of HCC cells. • miR-367 inhibitors inhibit the proliferation and invasion of HCC cells. • miR-367 targets 3′UTR of PTEN in HCC cells. • miR-367 negatively regulates PTEN in HCC cells.

  1. DOF-binding sites additively contribute to guard cell-specificity of AtMYB60 promoter

    Directory of Open Access Journals (Sweden)

    Cominelli Eleonora

    2011-11-01

    Full Text Available Abstract Background We previously demonstrated that the Arabidopsis thaliana AtMYB60 protein is an R2R3MYB transcription factor required for stomatal opening. AtMYB60 is specifically expressed in guard cells and down-regulated at the transcriptional levels by the phytohormone ABA. Results To investigate the molecular mechanisms governing AtMYB60 expression, its promoter was dissected through deletion and mutagenesis analyses. By studying different versions of AtMYB60 promoter::GUS reporter fusions in transgenic plants we were able to demonstrate a modular organization for the AtMYB60 promoter. Particularly we defined: a minimal promoter sufficient to confer guard cell-specific activity to the reporter gene; the distinct roles of different DOF-binding sites organised in a cluster in the minimal promoter in determining guard cell-specific expression; the promoter regions responsible for the enhancement of activity in guard cells; a promoter region responsible for the negative transcriptional regulation by ABA. Moreover from the analysis of single and multiple mutants we could rule out the involvement of a group of DOF proteins, known as CDFs, already characterised for their involvement in flowering time, in the regulation of AtMYB60 expression. Conclusions These findings shed light on the regulation of gene expression in guard cells and provide new promoter modules as useful tools for manipulating gene expression in guard cells, both for physiological studies and future biotechnological applications.

  2. Tafazzin (TAZ promotes the tumorigenicity of cervical cancer cells and inhibits apoptosis.

    Directory of Open Access Journals (Sweden)

    Mei Chen

    Full Text Available Tafazzin (TAZ is often aberrantly expressed in some cancers, including rectal cancer and thyroid neoplasms. However, the function of TAZ in cervical cancer cells remains unknown. This study aims to explore the expression and function of TAZ in cervical cancer cells. Here, we determined the expression of TAZ protein in normal cervical tissue (NC, n = 27, high-grade squamous intraepithelial lesions (HSIL, n = 26 and squamous cervical carcinoma (SCC, n = 41 by immunohistochemistry, the expression of TAZ protein gradually increased from NC to HSIL to SCC. TAZ was overexpressed or down-regulated in cervical cancer cells by stably transfecting a TAZ-expressing plasmid or a shRNA plasmid targeting TAZ. In vitro, the cell growth curves and MTT assays showed that TAZ may promote the growth and viability of cervical cancer cells. In vivo, xenografts experiment showed that TAZ may increase tumor-forming ability. The percentage of apoptosis cells analyzed by FACS and TUNEL assays consistently showed that TAZ inhibits apoptosis in cervical cancer cells. Furthermore, the Cleaved Caspase 9 and Cleaved Caspase 3 were down-regulated by TAZ in cervical cancer cells. Taken together, this study demonstrated that TAZ is overexpressed in cervical cancer and may promote tumorigenicity of cervical cancer cells and inhibit apoptosis.

  3. Gliadin fragments promote migration of dendritic cells

    Czech Academy of Sciences Publication Activity Database

    Chládková, Barbara; Kamanová, Jana; Palová-Jelínková, Lenka; Cinová, Jana; Šebo, Peter; Tučková, Ludmila

    2011-01-01

    Roč. 15, č. 4 (2011), 938-948 ISSN 1582-1838 R&D Projects: GA ČR GA310/07/0414; GA ČR GD310/08/H077; GA ČR GA310/08/0447; GA AV ČR IAA500200801; GA AV ČR IAA500200914 Institutional research plan: CEZ:AV0Z50200510 Keywords : celiac disease * gliadin * dendritic cell Subject RIV: EC - Immunology Impact factor: 4.125, year: 2011

  4. The Murine Factor H-Related Protein FHR-B Promotes Complement Activation

    Directory of Open Access Journals (Sweden)

    Marcell Cserhalmi

    2017-09-01

    Full Text Available Factor H-related (FHR proteins consist of varying number of complement control protein domains that display various degrees of sequence identity to respective domains of the alternative pathway complement inhibitor factor H (FH. While such FHR proteins are described in several species, only human FHRs were functionally investigated. Their biological role is still poorly understood and in part controversial. Recent studies on some of the human FHRs strongly suggest a role for FHRs in enhancing complement activation via competing with FH for binding to certain ligands and surfaces. The aim of the current study was the functional characterization of a murine FHR, FHR-B. To this end, FHR-B was expressed in recombinant form. Recombinant FHR-B bound to human C3b and was able to compete with human FH for C3b binding. FHR-B supported the assembly of functionally active C3bBb alternative pathway C3 convertase via its interaction with C3b. This activity was confirmed by demonstrating C3 activation in murine serum. In addition, FHR-B bound to murine pentraxin 3 (PTX3, and this interaction resulted in murine C3 fragment deposition due to enhanced complement activation in mouse serum. FHR-B also induced C3 deposition on C-reactive protein, the extracellular matrix (ECM extract Matrigel, and endothelial cell-derived ECM when exposed to mouse serum. Moreover, mouse C3 deposition was strongly enhanced on necrotic Jurkat T cells and the mouse B cell line A20 by FHR-B. FHR-B also induced lysis of sheep erythrocytes when incubated in mouse serum with FHR-B added in excess. Altogether, these data demonstrate that, similar to human FHR-1 and FHR-5, mouse FHR-B modulates complement activity by promoting complement activation via interaction with C3b and via competition with murine FH.

  5. BIGH3 protein and macrophages in retinal endothelial cell apoptosis.

    Science.gov (United States)

    Mondragon, Albert A; Betts-Obregon, Brandi S; Moritz, Robert J; Parvathaneni, Kalpana; Navarro, Mary M; Kim, Hong Seok; Lee, Chi Fung; LeBaron, Richard G; Asmis, Reto; Tsin, Andrew T

    2015-01-01

    Diabetes is a pandemic disease with a higher occurrence in minority populations. The molecular mechanism to initiate diabetes-associated retinal angiogenesis remains largely unknown. We propose an inflammatory pathway of diabetic retinopathy in which macrophages in the diabetic eye provide TGFβ to retinal endothelial cells (REC) in the retinal microvasculature. In response to TGFβ, REC synthesize and secrete a pro-apoptotic BIGH3 (TGFβ-Induced Gene Human Clone 3) protein, which acts in an autocrine loop to induce REC apoptosis. Rhesus monkey retinal endothelial cells (RhREC) were treated with dMCM (cell media of macrophages treated with high glucose and LDL) and assayed for apoptosis (TUNEL), BIGH3 mRNA (qPCR), and protein (Western blots) expressions. Cells were also treated with ΤGFβ1 and 2 for BIGH3 mRNA and protein expression. Inhibition assays were carried out using antibodies for TGFβ1 and for BIGH3 to block apoptosis and mRNA expression. BIGH3 in cultured RhREC cells were identified by immunohistochemistry (IHC). Distribution of BIGH3 and macrophages in the diabetic mouse retina was examined with IHC. RhRECs treated with dMCM or TGFβ showed a significant increase in apoptosis and BIGH3 protein expression. Recombinant BIGH3 added to RhREC culture medium led to a dose-dependent increase in apoptosis. Antibodies (Ab) directed against BIGH3 and TGFβ, as well as TGFβ receptor blocker resulted in a significant reduction in apoptosis induced by either dMCM, TGFβ or BIGH3. IHC showed that cultured RhREC constitutively expressed BIGH3. Macrophage and BIGH3 protein were co-localized to the inner retina of the diabetic mouse eye. Our results support a novel inflammatory pathway for diabetic retinopathy. This pathway is initiated by TGFβ released from macrophages, which promotes synthesis and release of BIGH3 protein by REC and REC apoptosis.

  6. The oncoprotein HBXIP upregulates PDGFB via activating transcription factor Sp1 to promote the proliferation of breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yingyi; Zhao, Yu; Li, Leilei; Shen, Yu; Cai, Xiaoli [Department of Biochemistry, College of Life Sciences, Nankai University, Tianjin 300071 (China); Zhang, Xiaodong, E-mail: zhangxd@nankai.edu.cn [Department of Cancer Research, Institute for Molecular Biology, College of Life Sciences, Nankai University, Tianjin 300071 (China); Ye, Lihong, E-mail: yelihong@nankai.edu.cn [Department of Biochemistry, College of Life Sciences, Nankai University, Tianjin 300071 (China)

    2013-05-03

    Highlights: •HBXIP is able to upregulate the expression of PDGFB in breast cancer cells. •HBXIP serves as a coactivator of activating transcription factor Sp1. •HBXIP stimulates the PDGFB promoter via activating transcription factor Sp1. •HBXIP promotes the proliferation of breast cancer cell via upregulating PDGFB. -- Abstract: We have reported that the oncoprotein hepatitis B virus X-interacting protein (HBXIP) acts as a novel transcriptional coactivator to promote proliferation and migration of breast cancer cells. Previously, we showed that HBXIP was able to activate nuclear factor-κB (NF-κB) in breast cancer cells. As an oncogene, the platelet-derived growth factor beta polypeptide (PDGFB) plays crucial roles in carcinogenesis. In the present study, we found that both HBXIP and PDGFB were highly expressed in breast cancer cell lines. Interestingly, HBXIP was able to increase transcriptional activity of NF-κB through PDGFB, suggesting that HBXIP is associated with PDGFB in the cells. Moreover, HBXIP was able to upregulate PDGFB at the levels of mRNA, protein and promoter in the cells. Then, we identified that HBXIP stimulated the promoter of PDGFB through activating transcription factor Sp1. In function, HBXIP enhanced the proliferation of breast cancer cells through PDGFB in vitro. Thus, we conclude that HBXIP upregulates PDGFB via activating transcription factor Sp1 to promote proliferation of breast cancer cells.

  7. The oncoprotein HBXIP upregulates PDGFB via activating transcription factor Sp1 to promote the proliferation of breast cancer cells

    International Nuclear Information System (INIS)

    Zhang, Yingyi; Zhao, Yu; Li, Leilei; Shen, Yu; Cai, Xiaoli; Zhang, Xiaodong; Ye, Lihong

    2013-01-01

    Highlights: •HBXIP is able to upregulate the expression of PDGFB in breast cancer cells. •HBXIP serves as a coactivator of activating transcription factor Sp1. •HBXIP stimulates the PDGFB promoter via activating transcription factor Sp1. •HBXIP promotes the proliferation of breast cancer cell via upregulating PDGFB. -- Abstract: We have reported that the oncoprotein hepatitis B virus X-interacting protein (HBXIP) acts as a novel transcriptional coactivator to promote proliferation and migration of breast cancer cells. Previously, we showed that HBXIP was able to activate nuclear factor-κB (NF-κB) in breast cancer cells. As an oncogene, the platelet-derived growth factor beta polypeptide (PDGFB) plays crucial roles in carcinogenesis. In the present study, we found that both HBXIP and PDGFB were highly expressed in breast cancer cell lines. Interestingly, HBXIP was able to increase transcriptional activity of NF-κB through PDGFB, suggesting that HBXIP is associated with PDGFB in the cells. Moreover, HBXIP was able to upregulate PDGFB at the levels of mRNA, protein and promoter in the cells. Then, we identified that HBXIP stimulated the promoter of PDGFB through activating transcription factor Sp1. In function, HBXIP enhanced the proliferation of breast cancer cells through PDGFB in vitro. Thus, we conclude that HBXIP upregulates PDGFB via activating transcription factor Sp1 to promote proliferation of breast cancer cells

  8. Advanced glycation end products promote ChREBP expression and cell proliferation in liver cancer cells by increasing reactive oxygen species.

    Science.gov (United States)

    Chen, Hanbei; Li, Yakui; Zhu, Yemin; Wu, Lifang; Meng, Jian; Lin, Ning; Yang, Dianqiang; Li, Minle; Ding, WenJin; Tong, Xuemei; Su, Qing

    2017-08-01

    The aim of the study was to elucidate the mechanism by which advanced glycation end products (AGEs) promote cell proliferation in liver cancer cells.We treated liver cancer HepG2 cells with 200 mg/L AGEs or bovine serum albumin (BSA) and assayed for cell viability, cell cycle, and apoptosis. We performed real-time PCR and Western blot analysis for RNA and protein levels of carbohydrate responsive element-binding protein (ChREBP) in AGEs- or BSA-treated HepG2 cells. We analyzed the level of reactive oxygen species (ROS) in HepG2 cells treated with AGEs or BSA.We found that increased S-phase cell percentage and decreased apoptosis contributed to AGEs-induced liver cancer cell proliferation. Real-time PCR and Western blot analysis showed that AGEs stimulated RNA and protein levels of ChREBP, a transcription factor promoting glycolysis and maintaining cell proliferation in liver cancer cells. Intriguingly, the level of ROS was higher in AGEs-treated liver cancer cells. Treating liver cancer cells with antioxidant N-acetyl cystein (NAC) partly blocked AGEs-induced ChREBP expression and cell proliferation.Our results suggest that the AGEs-ROS-ChREBP pathway plays a critical role in promoting ChREBP expression and liver cancer cell proliferation.

  9. Epithelial membrane protein-2 promotes endometrial tumor formation through activation of FAK and Src.

    Directory of Open Access Journals (Sweden)

    Maoyong Fu

    Full Text Available Endometrial cancer is the most common gynecologic malignancy diagnosed among women in developed countries. One recent biomarker strongly associated with disease progression and survival is epithelial membrane protein-2 (EMP2, a tetraspan protein known to associate with and modify surface expression of certain integrin isoforms. In this study, we show using a xenograft model system that EMP2 expression is necessary for efficient endometrial tumor formation, and we have started to characterize the mechanism by which EMP2 contributes to this malignant phenotype. In endometrial cancer cells, the focal adhesion kinase (FAK/Src pathway appears to regulate migration as measured through wound healing assays. Manipulation of EMP2 levels in endometrial cancer cells regulates the phosphorylation of FAK and Src, and promotes their distribution into lipid raft domains. Notably, cells with low levels of EMP2 fail to migrate and poorly form tumors in vivo. These findings reveal the pivotal role of EMP2 in endometrial cancer carcinogenesis, and suggest that the association of elevated EMP2 levels with endometrial cancer prognosis may be causally linked to its effect on integrin-mediated signaling.

  10. ASIC proteins regulate smooth muscle cell migration.

    Science.gov (United States)

    Grifoni, Samira C; Jernigan, Nikki L; Hamilton, Gina; Drummond, Heather A

    2008-03-01

    The purpose of the present study was to investigate Acid Sensing Ion Channel (ASIC) protein expression and importance in cellular migration. We recently demonstrated that Epithelial Na(+)Channel (ENaC) proteins are required for vascular smooth muscle cell (VSMC) migration; however, the role of the closely related ASIC proteins has not been addressed. We used RT-PCR and immunolabeling to determine expression of ASIC1, ASIC2, ASIC3 and ASIC4 in A10 cells. We used small interference RNA to silence individual ASIC expression and determine the importance of ASIC proteins in wound healing and chemotaxis (PDGF-bb)-initiated migration. We found ASIC1, ASIC2, and ASIC3, but not ASIC4, expression in A10 cells. ASIC1, ASIC2, and ASIC3 siRNA molecules significantly suppressed expression of their respective proteins compared to non-targeting siRNA (RISC) transfected controls by 63%, 44%, and 55%, respectively. Wound healing was inhibited by 10, 20, and 26% compared to RISC controls following suppression of ASIC1, ASIC2, and ASIC3, respectively. Chemotactic migration was inhibited by 30% and 45%, respectively, following suppression of ASIC1 and ASIC3. ASIC2 suppression produced a small, but significant, increase in chemotactic migration (4%). Our data indicate that ASIC expression is required for normal migration and may suggest a novel role for ASIC proteins in cellular migration.

  11. Triiodothyronine promotes the proliferation of epicardial progenitor cells through the MAPK/ERK pathway

    International Nuclear Information System (INIS)

    Deng, Song-Bai; Jing, Xiao-Dong; Wei, Xiao-ming; Du, Jian-Lin; Liu, Ya-Jie; Qin, Qin; She, Qiang

    2017-01-01

    Thyroid hormone has important functions in the development and physiological function of the heart. The aim of this study was to determine whether 3,5,3′-Triiodothyronine (T3) can promote the proliferation of epicardial progenitor cells (EPCs) and to investigate the potential underlying mechanism. Our results showed that T3 significantly promoted the proliferation of EPCs in a concentration- and time-dependent manner. The thyroid hormone nuclear receptor inhibitor bisphenol A (100 μmol/L) did not affect T3's ability to induce proliferation. Further studies showed that the mRNA expression levels of mitogen-activated protein kinase 1 (MAPK1), MAPK3, and Ki67 in EPCs in the T3 group (10 nmol/L) increased 2.9-, 3-, and 4.1-fold, respectively, compared with those in the control group (P < 0.05). In addition, the mRNA expression of the cell cycle protein cyclin D1 in the T3 group increased approximately 2-fold compared with the control group (P < 0.05), and there were more EPCs in the S phase of the cell cycle (20.6% vs. 12.0%, P < 0.05). The mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) signaling pathway inhibitor U0126 (10 μmol/L) significantly inhibited the ability of T3 to promote the proliferation of EPCs and to alter cell cycle progression. This study suggested that T3 significantly promotes the proliferation of EPCs, and this effect may be achieved through activation of the MAPK/ERK signaling pathway. - Highlights: • Epicardial progenitor cells were successfully cultured from E12.5 mice. • Thyroid hormone T3 significantly promoted the proliferation of EPCs. • This biological effect may be mediated via activation of the MAPK/ERK pathway.

  12. B Cells Promote Th1- Skewed NKT Cell Response by CD1d-TCR Interaction.

    Science.gov (United States)

    Shin, Jung Hoon; Park, Se-Ho

    2013-10-01

    CD1d expressing dendritic cells (DCs) are good glyco-lipid antigen presenting cells for NKT cells. However, resting B cells are very weak stimulators for NKT cells. Although α-galactosylceramide (α-GalCer) loaded B cells can activate NKT cells, it is not well defined whether B cells interfere NKT cell stimulating activity of DCs. Unexpectedly, we found in this study that B cells can promote Th1-skewed NKT cell response, which means a increased level of IFN-γ by NKT cells, concomitant with a decreased level of IL-4, in the circumstance of co-culture of DCs and B Cells. Remarkably, the response promoted by B cells was dependent on CD1d expression of B cells.

  13. Ectodomain shedding of Limbic System-Associated Membrane Protein (LSAMP) by ADAM Metallopeptidases promotes neurite outgrowth in DRG neurons.

    Science.gov (United States)

    Sanz, Ricardo L; Ferraro, Gino B; Girouard, Marie-Pier; Fournier, Alyson E

    2017-08-11

    IgLONs are members of the immunoglobulin superfamily of cell adhesion proteins implicated in the process of neuronal outgrowth, cell adhesion and subdomain target recognition. IgLONs form homophilic and heterophilic complexes on the cell surface that repress or promote growth depending on the neuronal population, the developmental stage and surface repertoire of IgLON family members. In the present study, we identified a metalloproteinase-dependent mechanism necessary to promote growth in embryonic dorsal root ganglion cells (DRGs). Treatment of embryonic DRG neurons with pan-metalloproteinase inhibitors, tissue inhibitor of metalloproteinase-3, or an inhibitor of ADAM Metallopeptidase Domain 10 (ADAM10) reduces outgrowth from DRG neurons indicating that metalloproteinase activity is important for outgrowth. The IgLON family members Neurotrimin (NTM) and Limbic System-Associated Membrane Protein (LSAMP) were identified as ADAM10 substrates that are shed from the cell surface of DRG neurons. Overexpression of LSAMP and NTM suppresses outgrowth from DRG neurons. Furthermore, LSAMP loss of function decreases the outgrowth sensitivity to an ADAM10 inhibitor. Together our findings support a role for ADAM-dependent shedding of cell surface LSAMP in promoting outgrowth from DRG neurons.

  14. Promoter DNA hypermethylation and gene repression in undifferentiated Arabidopsis cells.

    Directory of Open Access Journals (Sweden)

    María Berdasco

    Full Text Available Maintaining and acquiring the pluripotent cell state in plants is critical to tissue regeneration and vegetative multiplication. Histone-based epigenetic mechanisms are important for regulating this undifferentiated state. Here we report the use of genetic and pharmacological experimental approaches to show that Arabidopsis cell suspensions and calluses specifically repress some genes as a result of promoter DNA hypermethylation. We found that promoters of the MAPK12, GSTU10 and BXL1 genes become hypermethylated in callus cells and that hypermethylation also affects the TTG1, GSTF5, SUVH8, fimbrin and CCD7 genes in cell suspensions. Promoter hypermethylation in undifferentiated cells was associated with histone hypoacetylation and primarily occurred at CpG sites. Accordingly, we found that the process specifically depends on MET1 and DRM2 methyltransferases, as demonstrated with DNA methyltransferase mutants. Our results suggest that promoter DNA methylation may be another important epigenetic mechanism for the establishment and/or maintenance of the undifferentiated state in plant cells.

  15. Effect of Protein Hydrolysates on Pancreatic Cancer Cells

    DEFF Research Database (Denmark)

    Ossum, Carlo G.; Andersen, Lisa Lystbæk; Nielsen, Henrik Hauch

    Effect of Fish Protein Hydrolysates on Pancreatic Cancer Cells Carlo G. Ossum1, Lisa Lystbæk Andersen2, Henrik Hauch Nielsen2, Else K. Hoffmann1, and Flemming Jessen2 1University of Copenhagen, Department of Biology, Denmark, 2Technical University of Denmark (DTU), National Food Institute, Denmark...... hydrolysates obtained by enzymatic hydrolysis on cancer cell proliferation. Skin and belly flap muscle from trout were hydrolysed with the unspecific proteases Alcalase, Neutrase, or UE1 (all from Novozymes, Bagsværd, Denmark) to a hydrolysis degree of 1-15%. The hydrolysates were tested for biological...... activities affecting cell proliferation and ability to modulate caspase activity in pancreatic cancer cells COLO357 and BxPC-3 in vitro. A number of the hydrolysates showed caspase promoting activity; in particular products containing muscle tissue, i.e. belly flap, were able to stimulate caspase activity...

  16. Inhibition of NF-κB promotes autophagy via JNK signaling pathway in porcine granulosa cells

    International Nuclear Information System (INIS)

    Gao, Hui; Lin, Lu; Haq, Ihtesham Ul; Zeng, Shen-ming

    2016-01-01

    The transcription factor nuclear factor-κB (NF-κB) plays an important role in diverse processes, including cell proliferation and differentiation, apoptosis and inflammation. However, the role of NF-κB in porcine follicle development is not clearly elucidated. In this study, we demonstrated that follicle stimulating hormone (FSH) increased the level of inhibitor of NF-κB (IκB) protein and promoted the cytoplasmic localization of p65, indicating that FSH inhibits the activation of NF-κB in porcine granulosa cells. Moreover, inhibition of NF-κB by FSH or another specific inhibitor of NF-κB, pyrrolidine dithiocarbamate (PDTC), could activate JNK signaling and enhance autophagic activity in porcine granulosa cells. Knockdown of RelA (p65) Subunit of NF-κB by RNA interference abrogated the activation of JNK signaling pathway and the increase of autophagic protein expression by FSH. Meanwhile, the functional significance of FSH or PDTC-mediated autophagy were further investigated. Our results demonstrated that the increased autophagy promoted progesterone secretion in porcine granulosa cells. Blockage of autophagy by chloroquine obviated the FSH or PDTC-induced progesterone production. Taken together, these results indicate that inhibition of NF-κB increased autophagy via JNK signaling, and promote steroidogenesis in porcine granulosa cells. Our results provide new insights into the regulation and function of autophagy in mammalian follicle development. - Highlights: • FSH inhibits the activation of NF-κB in porcine primary granulosa cells. • Inhibition of NF-κB by FSH promotes autophagy via JNK signaling in granulosa cells. • Increased autophagy contributes to progesterone production in granulosa cells. • This is the first report against beclin1 regulation in porcine granulosa cells.

  17. Inhibition of NF-κB promotes autophagy via JNK signaling pathway in porcine granulosa cells

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Hui; Lin, Lu; Haq, Ihtesham Ul; Zeng, Shen-ming, E-mail: zengshenming@gmail.com

    2016-04-22

    The transcription factor nuclear factor-κB (NF-κB) plays an important role in diverse processes, including cell proliferation and differentiation, apoptosis and inflammation. However, the role of NF-κB in porcine follicle development is not clearly elucidated. In this study, we demonstrated that follicle stimulating hormone (FSH) increased the level of inhibitor of NF-κB (IκB) protein and promoted the cytoplasmic localization of p65, indicating that FSH inhibits the activation of NF-κB in porcine granulosa cells. Moreover, inhibition of NF-κB by FSH or another specific inhibitor of NF-κB, pyrrolidine dithiocarbamate (PDTC), could activate JNK signaling and enhance autophagic activity in porcine granulosa cells. Knockdown of RelA (p65) Subunit of NF-κB by RNA interference abrogated the activation of JNK signaling pathway and the increase of autophagic protein expression by FSH. Meanwhile, the functional significance of FSH or PDTC-mediated autophagy were further investigated. Our results demonstrated that the increased autophagy promoted progesterone secretion in porcine granulosa cells. Blockage of autophagy by chloroquine obviated the FSH or PDTC-induced progesterone production. Taken together, these results indicate that inhibition of NF-κB increased autophagy via JNK signaling, and promote steroidogenesis in porcine granulosa cells. Our results provide new insights into the regulation and function of autophagy in mammalian follicle development. - Highlights: • FSH inhibits the activation of NF-κB in porcine primary granulosa cells. • Inhibition of NF-κB by FSH promotes autophagy via JNK signaling in granulosa cells. • Increased autophagy contributes to progesterone production in granulosa cells. • This is the first report against beclin1 regulation in porcine granulosa cells.

  18. Serine-rich repeat proteins and pili promote Streptococcus agalactiae colonization of the vaginal tract.

    Science.gov (United States)

    Sheen, Tamsin R; Jimenez, Alyssa; Wang, Nai-Yu; Banerjee, Anirban; van Sorge, Nina M; Doran, Kelly S

    2011-12-01

    Streptococcus agalactiae (group B streptococcus [GBS]) is a Gram-positive bacterium found in the female rectovaginal tract and is capable of producing severe disease in susceptible hosts, including newborns and pregnant women. The vaginal tract is considered a major reservoir for GBS, and maternal vaginal colonization poses a significant risk to the newborn; however, little is known about the specific bacterial factors that promote GBS colonization and persistence in the female reproductive tract. We have developed in vitro models of GBS interaction with the human female cervicovaginal tract using human vaginal and cervical epithelial cell lines. Analysis of isogenic mutant GBS strains deficient in cell surface organelles such as pili and serine-rich repeat (Srr) proteins shows that these factors contribute to host cell attachment. As Srr proteins are heavily glycosylated, we confirmed that carbohydrate moieties contribute to the effective interaction of Srr-1 with vaginal epithelial cells. Antibody inhibition assays identified keratin 4 as a possible host receptor for Srr-1. Our findings were further substantiated in an in vivo mouse model of GBS vaginal colonization, where mice inoculated with an Srr-1-deficient mutant exhibited decreased GBS vaginal persistence compared to those inoculated with the wild-type (WT) parental strain. Furthermore, competition experiments in mice showed that WT GBS exhibited a significant survival advantage over the ΔpilA or Δsrr-1 mutant in the vaginal tract. Our results suggest that these GBS surface proteins contribute to vaginal colonization and may offer new insights into the mechanisms of vaginal niche establishment.

  19. Serine-Rich Repeat Proteins and Pili Promote Streptococcus agalactiae Colonization of the Vaginal Tract ▿

    Science.gov (United States)

    Sheen, Tamsin R.; Jimenez, Alyssa; Wang, Nai-Yu; Banerjee, Anirban; van Sorge, Nina M.; Doran, Kelly S.

    2011-01-01

    Streptococcus agalactiae (group B streptococcus [GBS]) is a Gram-positive bacterium found in the female rectovaginal tract and is capable of producing severe disease in susceptible hosts, including newborns and pregnant women. The vaginal tract is considered a major reservoir for GBS, and maternal vaginal colonization poses a significant risk to the newborn; however, little is known about the specific bacterial factors that promote GBS colonization and persistence in the female reproductive tract. We have developed in vitro models of GBS interaction with the human female cervicovaginal tract using human vaginal and cervical epithelial cell lines. Analysis of isogenic mutant GBS strains deficient in cell surface organelles such as pili and serine-rich repeat (Srr) proteins shows that these factors contribute to host cell attachment. As Srr proteins are heavily glycosylated, we confirmed that carbohydrate moieties contribute to the effective interaction of Srr-1 with vaginal epithelial cells. Antibody inhibition assays identified keratin 4 as a possible host receptor for Srr-1. Our findings were further substantiated in an in vivo mouse model of GBS vaginal colonization, where mice inoculated with an Srr-1-deficient mutant exhibited decreased GBS vaginal persistence compared to those inoculated with the wild-type (WT) parental strain. Furthermore, competition experiments in mice showed that WT GBS exhibited a significant survival advantage over the ΔpilA or Δsrr-1 mutant in the vaginal tract. Our results suggest that these GBS surface proteins contribute to vaginal colonization and may offer new insights into the mechanisms of vaginal niche establishment. PMID:21984789

  20. B Cells Promote Th1- Skewed NKT Cell Response by CD1d-TCR Interaction

    OpenAIRE

    Shin, Jung Hoon; Park, Se-Ho

    2013-01-01

    CD1d expressing dendritic cells (DCs) are good glyco-lipid antigen presenting cells for NKT cells. However, resting B cells are very weak stimulators for NKT cells. Although ?-galactosylceramide (?-GalCer) loaded B cells can activate NKT cells, it is not well defined whether B cells interfere NKT cell stimulating activity of DCs. Unexpectedly, we found in this study that B cells can promote Th1-skewed NKT cell response, which means a increased level of IFN-? by NKT cells, concomitant with a d...

  1. MRG15 activates the cdc2 promoter via histone acetylation in human cells

    Energy Technology Data Exchange (ETDEWEB)

    Pena, AndreAna N., E-mail: andreana.pena@gmail.com [Sam and Ann Barshop Institute for Longevity and Aging Studies, The University of Texas Health Science Center at San Antonio, San Antonio, TX (United States); Department of Cellular and Structural Biology, The University of Texas Health Science Center at San Antonio, San Antonio, TX (United States); Tominaga, Kaoru; Pereira-Smith, Olivia M. [Sam and Ann Barshop Institute for Longevity and Aging Studies, The University of Texas Health Science Center at San Antonio, San Antonio, TX (United States); Department of Cellular and Structural Biology, The University of Texas Health Science Center at San Antonio, San Antonio, TX (United States)

    2011-07-01

    Chromatin remodeling is required for transcriptional activation and repression. MRG15 (MORF4L1), a chromatin modulator, is a highly conserved protein and is present in complexes containing histone acetyltransferases (HATs) as well as histone deacetylases (HDACs). Loss of expression of MRG15 in mice and Drosophila results in embryonic lethality and fibroblast and neural stem/progenitor cells cultured from Mrg15 null mouse embryos exhibit marked proliferative defects when compared with wild type cells. To determine the role of MRG15 in cell cycle progression we performed chromatin immunoprecipitation with an antibody to MRG15 on normal human fibroblasts as they entered the cell cycle from a quiescent state, and analyzed various cell cycle gene promoters. The results demonstrated a 3-fold increase in MRG15 occupancy at the cdc2 promoter during S phase of the cell cycle and a concomitant increase in acetylated histone H4. H4 lysine 12 was acetylated at 24 h post-serum stimulation while there was no change in acetylation of lysine 16. HDAC1 and 2 were decreased at this promoter during cell cycle progression. Over-expression of MRG15 in HeLa cells activated a cdc2 promoter-reporter construct in a dose-dependent manner, whereas knockdown of MRG15 resulted in decreased promoter activity. In order to implicate HAT activity, we treated cells with the HAT inhibitor anacardic acid and determined that HAT inhibition results in loss of expression of cdc2 mRNA. Further, chromatin immunoprecipitation with Tip60 localizes the protein to the same 110 bp stretch of the cdc2 promoter pulled down by MRG15. Additionally, we determined that cotransfection of MRG15 with the known associated HAT Tip60 had a cooperative effect in activating the cdc2 promoter. These results suggest that MRG15 is acting in a HAT complex involving Tip60 to modify chromatin via acetylation of histone H4 at the cdc2 promoter to activate transcription.

  2. MRG15 activates the cdc2 promoter via histone acetylation in human cells

    International Nuclear Information System (INIS)

    Pena, AndreAna N.; Tominaga, Kaoru; Pereira-Smith, Olivia M.

    2011-01-01

    Chromatin remodeling is required for transcriptional activation and repression. MRG15 (MORF4L1), a chromatin modulator, is a highly conserved protein and is present in complexes containing histone acetyltransferases (HATs) as well as histone deacetylases (HDACs). Loss of expression of MRG15 in mice and Drosophila results in embryonic lethality and fibroblast and neural stem/progenitor cells cultured from Mrg15 null mouse embryos exhibit marked proliferative defects when compared with wild type cells. To determine the role of MRG15 in cell cycle progression we performed chromatin immunoprecipitation with an antibody to MRG15 on normal human fibroblasts as they entered the cell cycle from a quiescent state, and analyzed various cell cycle gene promoters. The results demonstrated a 3-fold increase in MRG15 occupancy at the cdc2 promoter during S phase of the cell cycle and a concomitant increase in acetylated histone H4. H4 lysine 12 was acetylated at 24 h post-serum stimulation while there was no change in acetylation of lysine 16. HDAC1 and 2 were decreased at this promoter during cell cycle progression. Over-expression of MRG15 in HeLa cells activated a cdc2 promoter-reporter construct in a dose-dependent manner, whereas knockdown of MRG15 resulted in decreased promoter activity. In order to implicate HAT activity, we treated cells with the HAT inhibitor anacardic acid and determined that HAT inhibition results in loss of expression of cdc2 mRNA. Further, chromatin immunoprecipitation with Tip60 localizes the protein to the same 110 bp stretch of the cdc2 promoter pulled down by MRG15. Additionally, we determined that cotransfection of MRG15 with the known associated HAT Tip60 had a cooperative effect in activating the cdc2 promoter. These results suggest that MRG15 is acting in a HAT complex involving Tip60 to modify chromatin via acetylation of histone H4 at the cdc2 promoter to activate transcription.

  3. Enhanced Heme Function and Mitochondrial Respiration Promote the Progression of Lung Cancer Cells

    Science.gov (United States)

    Alam, Md Maksudul; Shah, Ajit; Cao, Thai M.; Sullivan, Laura A.; Brekken, Rolf; Zhang, Li

    2013-01-01

    Lung cancer is the leading cause of cancer-related mortality, and about 85% of the cases are non-small-cell lung cancer (NSCLC). Importantly, recent advance in cancer research suggests that altering cancer cell bioenergetics can provide an effective way to target such advanced cancer cells that have acquired mutations in multiple cellular regulators. This study aims to identify bioenergetic alterations in lung cancer cells by directly measuring and comparing key metabolic activities in a pair of cell lines representing normal and NSCLC cells developed from the same patient. We found that the rates of oxygen consumption and heme biosynthesis were intensified in NSCLC cells. Additionally, the NSCLC cells exhibited substantially increased levels in an array of proteins promoting heme synthesis, uptake and function. These proteins include the rate-limiting heme biosynthetic enzyme ALAS, transporter proteins HRG1 and HCP1 that are involved in heme uptake, and various types of oxygen-utilizing hemoproteins such as cytoglobin and cytochromes. Several types of human tumor xenografts also displayed increased levels of such proteins. Furthermore, we found that lowering heme biosynthesis and uptake, like lowering mitochondrial respiration, effectively reduced oxygen consumption, cancer cell proliferation, migration and colony formation. In contrast, lowering heme degradation does not have an effect on lung cancer cells. These results show that increased heme flux and function are a key feature of NSCLC cells. Further, increased generation and supply of heme and oxygen-utilizing hemoproteins in cancer cells will lead to intensified oxygen consumption and cellular energy production by mitochondrial respiration, which would fuel cancer cell proliferation and progression. The results show that inhibiting heme and respiratory function can effectively arrest the progression of lung cancer cells. Hence, understanding heme function can positively impact on research in lung cancer

  4. KIF20A-Mediated RNA Granule Transport System Promotes the Invasiveness of Pancreatic Cancer Cells

    Directory of Open Access Journals (Sweden)

    Keisuke Taniuchi

    2014-12-01

    Full Text Available Pancreatic cancers are aggressive because they are highly invasive and highly metastatic; moreover, effective treatments for aggressive pancreatic cancers are lacking. Here, we report that the motor kinesin protein KIF20A promoted the motility and invasiveness of pancreatic cancer cells through transporting the RNA-binding protein IGF2BP3 and IGF2BP3-bound transcripts toward cell protrusions along microtubules. We previously reported that IGF2BP3 and its target transcripts are assembled into cytoplasmic stress granules of pancreatic cancer cells, and that IGF2BP3 promotes the motility and invasiveness of pancreatic cancer cells through regulation of localized translation of IGF2BP3-bound transcripts in cell protrusions. We show that knockdown of KIF20A inhibited accumulation of IGF2BP3-containing stress granules in cell protrusions and suppressed local protein expression from specific IGF2BP3-bound transcripts, ARF6 and ARHGEF4, in the protrusions. Our results provide insight into the link between regulation of KIF20A-mediated trafficking of IGF2BP3-containing stress granules and modulation of the motility and invasiveness in pancreatic cancers.

  5. Transcriptional factor DLX3 promotes the gene expression of enamel matrix proteins during amelogenesis.

    Science.gov (United States)

    Zhang, Zhichun; Tian, Hua; Lv, Ping; Wang, Weiping; Jia, Zhuqing; Wang, Sainan; Zhou, Chunyan; Gao, Xuejun

    2015-01-01

    Mutation of distal-less homeobox 3 (DLX3) is responsible for human tricho-dento-osseous syndrome (TDO) with amelogenesis imperfecta, indicating a crucial role of DLX3 in amelogenesis. However, the expression pattern of DLX3 and its specific function in amelogenesis remain largely unknown. The aim of this study was to investigate the effects of DLX3 on enamel matrix protein (EMP) genes. By immunohistochemistry assays of mouse tooth germs, stronger immunostaining of DLX3 protein was identified in ameloblasts in the secretory stage than in the pre-secretory and maturation stages, and the same pattern was found for Dlx3 mRNA using Realtime PCR. In a mouse ameloblast cell lineage, forced expression of DLX3 up-regulated the expression of the EMP genes Amelx, Enam, Klk4, and Odam, whereas knockdown of DLX3 down-regulated these four EMP genes. Further, bioinformatics, chromatin immunoprecipitation, and luciferase assays revealed that DLX3 transactivated Enam, Amelx, and Odam through direct binding to their enhancer regions. Particularly, over-expression of mutant-DLX3 (c.571_574delGGGG, responsible for TDO) inhibited the activation function of DLX3 on expression levels and promoter activities of the Enam, Amelx, and Odam genes. Together, our data show that DLX3 promotes the expression of the EMP genes Amelx, Enam, Klk4, and Odam in amelogenesis, while mutant-DLX3 disrupts this regulatory function, thus providing insights into the molecular mechanisms underlying the enamel defects of TDO disease.

  6. The membrane protein LasM Promotes the Culturability of Legionella pneumophila in Water

    Directory of Open Access Journals (Sweden)

    Laam Li

    2016-09-01

    Full Text Available The water-borne pathogen Legionella pneumophila (Lp strongly expresses the lpg1659 gene in water. This gene encodes a hypothetical protein predicted to be a membrane protein using in silico analysis. While no conserved domains were identified in Lpg1659, similar proteins are found in many Legionella species and other aquatic bacteria. RT-qPCR showed that lpg1659 is positively regulated by the alternative sigma factor RpoS, which is essential for Lp to survive in water. These observations suggest an important role of this novel protein in the survival of Lp in water. Deletion of lpg1659 did not affect cell morphology, membrane integrity or tolerance to high temperature. Moreover, lpg1659 was dispensable for growth of Lp in rich medium, and during infection of the amoeba Acanthamoeba castellanii and of THP-1 human macrophages. However, deletion of lpg1659 resulted in an early loss of culturability in water, while over-expression of this gene promoted the culturability of Lp. Therefore, these results suggest that lpg1659 is required for Lp to maintain culturability, and possibly long-term survival, in water. Since the loss of culturability observed in the absence of Lpg1659 was complemented by the addition of trace metals into water, this membrane protein is likely a transporter for acquiring essential trace metal for maintaining culturability in water and potentially in other metal-deprived conditions. Given its role in the survival of Lp in water, Lpg1659 was named LasM for Legionella aquatic survival membrane protein.

  7. Intracellular Delivery of Proteins with Cell-Penetrating Peptides for Therapeutic Uses in Human Disease.

    Science.gov (United States)

    Dinca, Ana; Chien, Wei-Ming; Chin, Michael T

    2016-02-22

    Protein therapy exhibits several advantages over small molecule drugs and is increasingly being developed for the treatment of disorders ranging from single enzyme deficiencies to cancer. Cell-penetrating peptides (CPPs), a group of small peptides capable of promoting transport of molecular cargo across the plasma membrane, have become important tools in promoting the cellular uptake of exogenously delivered proteins. Although the molecular mechanisms of uptake are not firmly established, CPPs have been empirically shown to promote uptake of various molecules, including large proteins over 100 kiloDaltons (kDa). Recombinant proteins that include a CPP tag to promote intracellular delivery show promise as therapeutic agents with encouraging success rates in both animal and human trials. This review highlights recent advances in protein-CPP therapy and discusses optimization strategies and potential detrimental effects.

  8. Purified Human Dental Pulp Stem Cells Promote Osteogenic Regeneration.

    Science.gov (United States)

    Yasui, T; Mabuchi, Y; Toriumi, H; Ebine, T; Niibe, K; Houlihan, D D; Morikawa, S; Onizawa, K; Kawana, H; Akazawa, C; Suzuki, N; Nakagawa, T; Okano, H; Matsuzaki, Y

    2016-02-01

    Human dental pulp stem/progenitor cells (hDPSCs) are attractive candidates for regenerative therapy because they can be easily expanded to generate colony-forming unit-fibroblasts (CFU-Fs) on plastic and the large cell numbers required for transplantation. However, isolation based on adherence to plastic inevitably changes the surface marker expression and biological properties of the cells. Consequently, little is currently known about the original phenotypes of tissue precursor cells that give rise to plastic-adherent CFU-Fs. To better understand the in vivo functions and translational therapeutic potential of hDPSCs and other stem cells, selective cell markers must be identified in the progenitor cells. Here, we identified a dental pulp tissue-specific cell population based on the expression profiles of 2 cell-surface markers LNGFR (CD271) and THY-1 (CD90). Prospectively isolated, dental pulp-derived LNGFR(Low+)THY-1(High+) cells represent a highly enriched population of clonogenic cells--notably, the isolated cells exhibited long-term proliferation and multilineage differentiation potential in vitro. The cells also expressed known mesenchymal cell markers and promoted new bone formation to heal critical-size calvarial defects in vivo. These findings suggest that LNGFR(Low+)THY-1(High+) dental pulp-derived cells provide an excellent source of material for bone regenerative strategies. © International & American Associations for Dental Research 2015.

  9. Scaffold architecture and fibrin gels promote meniscal cell proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Pawelec, K. M., E-mail: pawelec.km@gmail.com, E-mail: jw626@cam.ac.uk; Best, S. M.; Cameron, R. E. [Cambridge Centre for Medical Materials, Materials Science and Metallurgy Department, University of Cambridge, Cambridge CB3 0FS (United Kingdom); Wardale, R. J., E-mail: pawelec.km@gmail.com, E-mail: jw626@cam.ac.uk [Division of Trauma and Orthopaedic Surgery, Department of Surgery, University of Cambridge, Cambridge CB2 2QQ (United Kingdom)

    2015-01-01

    Stability of the knee relies on the meniscus, a complex connective tissue with poor healing ability. Current meniscal tissue engineering is inadequate, as the signals for increasing meniscal cell proliferation have not been established. In this study, collagen scaffold structure, isotropic or aligned, and fibrin gel addition were tested. Metabolic activity was promoted by fibrin addition. Cellular proliferation, however, was significantly increased by both aligned architectures and fibrin addition. None of the constructs impaired collagen type I production or triggered adverse inflammatory responses. It was demonstrated that both fibrin gel addition and optimized scaffold architecture effectively promote meniscal cell proliferation.

  10. Promotion of initiated cells by radiation-induced cell inactivation.

    Science.gov (United States)

    Heidenreich, W F; Paretzke, H G

    2008-11-01

    Cells on the way to carcinogenesis can have a growth advantage relative to normal cells. It has been hypothesized that a radiation-induced growth advantage of these initiated cells might be induced by an increased cell replacement probability of initiated cells after inactivation of neighboring cells by radiation. Here Monte Carlo simulations extend this hypothesis for larger clones: The effective clonal expansion rate decreases with clone size. This effect is stronger for the two-dimensional than for the three-dimensional situation. The clones are irregular, far from a circular shape. An exposure-rate dependence of the effective clonal expansion rate could come in part from a minimal recovery time of the initiated cells for symmetric cell division.

  11. Transplantation of bone marrow derived cells promotes pancreatic islet repair in diabetic mice

    International Nuclear Information System (INIS)

    Gao Xiaodong; Song Lujun; Shen Kuntang; Wang Hongshan; Niu Weixin; Qin Xinyu

    2008-01-01

    The transplantation of bone marrow (BM) derived cells to initiate pancreatic regeneration is an attractive but as-yet unrealized strategy. Presently, BM derived cells from green fluorescent protein transgenic mice were transplanted into diabetic mice. Repair of diabetic islets was evidenced by reduction of hyperglycemia, increase in number of islets, and altered pancreatic histology. Cells in the pancreata of recipient mice co-expressed BrdU and insulin. Double staining revealed β cells were in the process of proliferation. BrdU + insulin - PDX-1 + cells, Ngn3 + cells and insulin + glucagon + cells, which showed stem cells, were also found during β-cell regeneration. The majority of transplanted cells were mobilized to the islet and ductal regions. In recipient pancreas, transplanted cells simultaneously expressed CD34 but did not express insulin, PDX-1, Ngn3, Nkx2.2, Nkx6.1, Pax4, Pax6, and CD45. It is concluded that BM derived cells especially CD34 + cells can promote repair of pancreatic islets. Moreover, both proliferation of β cells and differentiation of pancreatic stem cells contribute to the regeneration of β cells

  12. Direct inhibition of TNF-α promoter activity by Fanconi anemia protein FANCD2.

    Directory of Open Access Journals (Sweden)

    Nobuko Matsushita

    Full Text Available Fanconi anemia (FA, an inherited disease, is associated with progressive bone marrow failure, predisposition to cancer, and genomic instability. Genes corresponding to 15 identified FA complementation groups have been cloned, and each gene product functions in the response to DNA damage induced by cross-linking agents and/or in protection against genome instability. Interestingly, overproduction of inflammatory cytokines such as tumor necrosis factor alpha (TNF-α and aberrant activation of NF-κB-dependent transcriptional activity have been observed in FA cells. Here we demonstrated that FANCD2 protein inhibits NF-κB activity in its monoubiquitination-dependent manner. Furthermore, we detected a specific association between FANCD2 and an NF-κB consensus element in the TNF-α promoter by electrophoretic mobility shift assays (EMSA and chromatin immunoprecipitation (ChIP assay. Therefore, we propose FANCD2 deficiency promotes transcriptional activity of the TNF-α promoter and induces overproduction of TNF-which then sustains prolonged inflammatory responses. These results also suggest that artificial modulation of TNFα production could be a promising therapeutic approach to FA.

  13. RNA and protein synthesis of irradiated Ehrlich ascites tumour cells. Pt. 2

    International Nuclear Information System (INIS)

    Skog, S.; Tribukait, B.; Nygard, O.; Wenner-Gren-Center foer Vetenskaplig Forskning, Stockholm

    1985-01-01

    Poly(A)-containing RNA (m-RNA) was studied in in vivo growing Ehrlich ascites tumour cells following a roentgen irradiation dose of 5 Gy. m-RNA increased significantly during the first 12 hours after irradiation. Thus, the observed decrease in protein synthesis rate during this time seems not to be due to radiation induced changes at the transcriptional level. The protein synthesis rate of in vivo irradiated cells incubated in vitro in culture medium was unchanged. On the other hand, the protein synthesis rate of non-irradiated cells incubated in vitro in ascites fluid from irradiated animals was decreased. We concluded that factor(s) inhibiting protein synthesis or the lack of factor(s) promoting protein synthesis in the ascites fluid is(are) of significance for the reduced protein synthesis of tumour cells found in irradiated in vivo growing cells. (orig.)

  14. Insulin promotes cell migration by regulating PSA-NCAM

    Energy Technology Data Exchange (ETDEWEB)

    Monzo, Hector J.; Coppieters, Natacha [Centre for Brain Research, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag, 92019, Auckland (New Zealand); Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag, 92019, Auckland (New Zealand); Park, Thomas I.H. [Centre for Brain Research, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag, 92019, Auckland (New Zealand); Department of Pharmacology, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag, 92019, Auckland (New Zealand); Dieriks, Birger V.; Faull, Richard L.M. [Centre for Brain Research, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag, 92019, Auckland (New Zealand); Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag, 92019, Auckland (New Zealand); Dragunow, Mike [Centre for Brain Research, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag, 92019, Auckland (New Zealand); Department of Pharmacology, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag, 92019, Auckland (New Zealand); Curtis, Maurice A., E-mail: m.curtis@auckland.ac.nz [Centre for Brain Research, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag, 92019, Auckland (New Zealand); Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag, 92019, Auckland (New Zealand)

    2017-06-01

    Cellular interactions with the extracellular environment are modulated by cell surface polysialic acid (PSA) carried by the neural cell adhesion molecule (NCAM). PSA-NCAM is involved in cellular processes such as differentiation, plasticity, and migration, and is elevated in Alzheimer's disease as well as in metastatic tumour cells. Our previous work demonstrated that insulin enhances the abundance of cell surface PSA by inhibiting PSA-NCAM endocytosis. In the present study we have identified a mechanism for insulin-dependent inhibition of PSA-NCAM turnover affecting cell migration. Insulin enhanced the phosphorylation of the focal adhesion kinase leading to dissociation of αv-integrin/PSA-NCAM clusters, and promoted cell migration. Our results show that αv-integrin plays a key role in the PSA-NCAM turnover process. αv-integrin knockdown stopped PSA-NCAM from being endocytosed, and αv-integrin/PSA-NCAM clusters co-labelled intracellularly with Rab5, altogether indicating a role for αv-integrin as a carrier for PSA-NCAM during internalisation. Furthermore, inhibition of p-FAK caused dissociation of αv-integrin/PSA-NCAM clusters and counteracted the insulin-induced accumulation of PSA at the cell surface and cell migration was impaired. Our data reveal a functional association between the insulin/p-FAK-dependent regulation of PSA-NCAM turnover and cell migration through the extracellular matrix. Most importantly, they identify a novel mechanism for insulin-stimulated cell migration. - Highlights: • Insulin modulates PSA-NCAM turnover through upregulation of p-FAK. • P-FAK modulates αv-integrin/PSA-NCAM clustering. • αv-integrin acts as a carrier for PSA-NCAM endocytosis. • Cell migration is promoted by cell surface PSA. • Insulin promotes PSA-dependent migration in vitro.

  15. Insulin promotes cell migration by regulating PSA-NCAM

    International Nuclear Information System (INIS)

    Monzo, Hector J.; Coppieters, Natacha; Park, Thomas I.H.; Dieriks, Birger V.; Faull, Richard L.M.; Dragunow, Mike; Curtis, Maurice A.

    2017-01-01

    Cellular interactions with the extracellular environment are modulated by cell surface polysialic acid (PSA) carried by the neural cell adhesion molecule (NCAM). PSA-NCAM is involved in cellular processes such as differentiation, plasticity, and migration, and is elevated in Alzheimer's disease as well as in metastatic tumour cells. Our previous work demonstrated that insulin enhances the abundance of cell surface PSA by inhibiting PSA-NCAM endocytosis. In the present study we have identified a mechanism for insulin-dependent inhibition of PSA-NCAM turnover affecting cell migration. Insulin enhanced the phosphorylation of the focal adhesion kinase leading to dissociation of αv-integrin/PSA-NCAM clusters, and promoted cell migration. Our results show that αv-integrin plays a key role in the PSA-NCAM turnover process. αv-integrin knockdown stopped PSA-NCAM from being endocytosed, and αv-integrin/PSA-NCAM clusters co-labelled intracellularly with Rab5, altogether indicating a role for αv-integrin as a carrier for PSA-NCAM during internalisation. Furthermore, inhibition of p-FAK caused dissociation of αv-integrin/PSA-NCAM clusters and counteracted the insulin-induced accumulation of PSA at the cell surface and cell migration was impaired. Our data reveal a functional association between the insulin/p-FAK-dependent regulation of PSA-NCAM turnover and cell migration through the extracellular matrix. Most importantly, they identify a novel mechanism for insulin-stimulated cell migration. - Highlights: • Insulin modulates PSA-NCAM turnover through upregulation of p-FAK. • P-FAK modulates αv-integrin/PSA-NCAM clustering. • αv-integrin acts as a carrier for PSA-NCAM endocytosis. • Cell migration is promoted by cell surface PSA. • Insulin promotes PSA-dependent migration in vitro.

  16. Nuclear proteins interacting with the promoter region of the human granulocyte/macrophage colony-stimulating factor gene

    International Nuclear Information System (INIS)

    Shannon, M.F.; Gamble, J.R.; Vadas, M.A.

    1988-01-01

    The gene for human granulocyte/macrophage colony-stimulating factor (GM-CSF) is expressed in a tissue-specific as well as an activation-dependent manner. The interaction of nuclear proteins with the promoter region of the GM-CSF gene that is likely to be responsible for this pattern of GM-CSF expression was investigated. The authors show that nuclear proteins interact with DNA fragments from the GM-CSF promoter in a cell-specific manner. A region spanning two cytokine-specific sequences, cytokine 1 (CK-1, 5', GAGATTCCAC 3') and cytokine 2 (CK-2, 5' TCAGGTA 3') bound two nuclear proteins from GM-CSF-expressing cells in gel retardation assays. NF-GMb was inducible with phorbol 12-myristate 13-acetate and accompanied induction of GM-CSF message. NF-GMb was absent in cell lines not producing GM-CSF, some of which had other distinct binding proteins. NF-GMa and NF-GMb eluted from a heparin-Sepharose column at 0.3 and 0.6 M KCl, respectively. They hypothesize that the sequences CK-1 and CK-2 bind specific proteins and regulate GM-CSF transcription

  17. Placental Growth Factor Promotes Ovarian Cancer Cell Invasion via ZEB2

    Directory of Open Access Journals (Sweden)

    Ning Song

    2016-01-01

    Full Text Available Background/Aims: The aggressive manner of ovarian cancer (OVC cells accounts for the majority of its lethality. Recently, we have shown that placental growth factor (PLGF promotes metastases of OVC cells through miR-543-regulated MMP7. In the current study, we analyzed the effects of PLGF on another cell invasion associated protein, ZEB2, in OVC cells. Methods: The PLGF and ZEB2 levels in OVC tissues were compared to the paired adjacent non-tumor ovary tissue. We modified ZEB2 levels in OVC cells, and examined its effects on PLGF mRNA and protein levels by RT-qPCR and by Western blot, respectively. We also modified PLGF levels in OVC cells, and examined its effects on ZEB2 mRNA and protein levels by RT-qPCR and by Western blot, respectively. Then, we examined the cell invasiveness in PLGF-modified OVC cells in a transwell cell invasion assay. Finally, we used specific signal pathway inhibitors to treat PLGF-modified OVC cells and examined the effects on ZEB2 activation. Results: PLGF and ZEB2 levels were both significantly increased in OVC tissues, compared to the paired adjacent non-tumor ovary tissue. The PLGF and ZEB2 levels were strongly correlated. ZEB2 modification did not alter PLGF levels. Overexpression of PLGF in OVC cells significantly increased ZEB2 levels and cell invasiveness, while PLGF depletion in OVC cells significantly decreased ZEB2 levels and cell invasiveness. Application of a specific MAPK-p38 inhibitor, but not application of specific inhibitors for MAPK-p42/p44, PI3k/Akt, or JNK signaling pathways, to PLGF-overexpressing OVC cells substantially abolished the PLGF-induced ZEB2 activation. Conclusion: PLGF enhances OVC cell invasion through MAPK-p38-dependent activation of ZEB2.

  18. Association with Aurora-A Controls N-MYC-Dependent Promoter Escape and Pause Release of RNA Polymerase II during the Cell Cycle

    DEFF Research Database (Denmark)

    Büchel, Gabriele; Carstensen, Anne; Mak, Ka-Yan

    2017-01-01

    MYC proteins bind globally to active promoters and promote transcriptional elongation by RNA polymerase II (Pol II). To identify effector proteins that mediate this function, we performed mass spectrometry on N-MYC complexes in neuroblastoma cells. The analysis shows that N-MYC forms complexes...

  19. Promoter Analysis Reveals Globally Differential Regulation of Human Long Non-Coding RNA and Protein-Coding Genes

    KAUST Repository

    Alam, Tanvir

    2014-10-02

    Transcriptional regulation of protein-coding genes is increasingly well-understood on a global scale, yet no comparable information exists for long non-coding RNA (lncRNA) genes, which were recently recognized to be as numerous as protein-coding genes in mammalian genomes. We performed a genome-wide comparative analysis of the promoters of human lncRNA and protein-coding genes, finding global differences in specific genetic and epigenetic features relevant to transcriptional regulation. These two groups of genes are hence subject to separate transcriptional regulatory programs, including distinct transcription factor (TF) proteins that significantly favor lncRNA, rather than coding-gene, promoters. We report a specific signature of promoter-proximal transcriptional regulation of lncRNA genes, including several distinct transcription factor binding sites (TFBS). Experimental DNase I hypersensitive site profiles are consistent with active configurations of these lncRNA TFBS sets in diverse human cell types. TFBS ChIP-seq datasets confirm the binding events that we predicted using computational approaches for a subset of factors. For several TFs known to be directly regulated by lncRNAs, we find that their putative TFBSs are enriched at lncRNA promoters, suggesting that the TFs and the lncRNAs may participate in a bidirectional feedback loop regulatory network. Accordingly, cells may be able to modulate lncRNA expression levels independently of mRNA levels via distinct regulatory pathways. Our results also raise the possibility that, given the historical reliance on protein-coding gene catalogs to define the chromatin states of active promoters, a revision of these chromatin signature profiles to incorporate expressed lncRNA genes is warranted in the future.

  20. Chronic exposure to trichloroethylene increases DNA methylation of the Ifng promoter in CD4+ T cells.

    Science.gov (United States)

    Gilbert, Kathleen M; Blossom, Sarah J; Erickson, Stephen W; Broadfoot, Brannon; West, Kirk; Bai, Shasha; Li, Jingyun; Cooney, Craig A

    2016-10-17

    CD4 + T cells in female MRL+/+ mice exposed to solvent and water pollutant trichloroethylene (TCE) skew toward effector/memory CD4 + T cells, and demonstrate seemingly non-monotonic alterations in IFN-γ production. In the current study we examined the mechanism for this immunotoxicity using effector/memory and naïve CD4 + T cells isolated every 6 weeks during a 40 week exposure to TCE (0.5mg/ml in drinking water). A time-dependent effect of TCE exposure on both Ifng gene expression and IFN-γ protein production was observed in effector/memory CD4 + T cells, with an increase after 22 weeks of exposure and a decrease after 40 weeks of exposure. No such effect of TCE was observed in naïve CD4 + T cells. A cumulative increase in DNA methylation in the CpG sites of the promoter of the Ifng gene was observed in effector/memory, but not naïve, CD4 + T cells over time. Also unique to the Ifng promoter was an increase in methylation variance in effector/memory compared to naïve CD4 + T cells. Taken together, the CpG sites of the Ifng promoter in effector/memory CD4 + T cells were especially sensitive to the effects of TCE exposure, which may help explain the regulatory effect of the chemical on this gene. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  1. In vitro and in vivo delivery of therapeutic proteins using cell penetrating peptides.

    Science.gov (United States)

    Bolhassani, Azam; Jafarzade, Behnaz Sadat; Mardani, Golnaz

    2017-01-01

    The failure of proteins to penetrate mammalian cells or target tumor cells restricts their value as therapeutic tools in a variety of diseases such as cancers. Recently, protein transduction domains (PTDs) or cell penetrating peptides (CPPs) have been shown to promote the delivery of therapeutic proteins or peptides into live cells. The successful delivery of proteins mainly depends on their physicochemical properties. Although, linear cell penetrating peptides are one of the most effective delivery vehicles; but currently, cyclic CPPs has been developed to potently transport bioactive full-length proteins into cells. Up to now, several small protein transduction domains from viral proteins including Tat or VP22 could be fused to other peptides or proteins to entry them in various cell types at a dose-dependent approach. A major disadvantage of PTD-fusion proteins is primary uptake into endosomal vesicles leading to inefficient release of the fusion proteins into the cytosol. Recently, non-covalent complex formation (Chariot) between proteins and CPPs has attracted a special interest to overcome some delivery limitations (e.g., toxicity). Many preclinical and clinical trials of CPP-based delivery are currently under evaluation. Generally, development of more efficient protein transduction domains would significantly increase the potency of protein therapeutics. Moreover, the synergistic or combined effects of CPPs with other delivery systems for protein/peptide drug delivery would promote their therapeutic effects in cancer and other diseases. In this review, we will describe the functions and implications of CPPs for delivering the therapeutic proteins or peptides in preclinical and clinical studies. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. CD147 overexpression promotes tumorigenicity in Chinese hamster ovary cells.

    Science.gov (United States)

    Yong, Yu-Le; Liao, Cheng-Gong; Wei, Ding; Chen, Zhi-Nan; Bian, Huijie

    2016-04-01

    CD147 overexpresses in many epithelium-originated tumors and plays an important role in tumor migration and invasion. Most studies aim at the role of CD147 in tumor progression using tumor cell models. However, the influence of abnormal overexpression of CD147 on neoplastic transformation of normal cells is unknown. Here, the role of CD147 in malignant phenotype transformation in CHO cells was investigated. Three CHO cell lines that stably overexpressed CD147 (CHO-CD147), EGFP-CD147 (CHO-EGFP-CD147), and EGFP (CHO-EGFP) were generated by transfection of plasmids containing human CD147, EGFP-human CD147, and EGFP genes into CHO cells. Cell migration and invasion were detected by wound healing and transwell matrix penetration assay. Trypan blue exclusion, MTT, cell cycle analysis, and BrdU cell proliferation assay were used to detect cell viability and cell proliferation. Annexin V-FITC analysis was performed to detect apoptosis. We found that CD147 overexpression promoted the migration and invasion of CHO cells. CD147 accelerated the G1 to S phase transition and enhanced the CHO cell proliferation. Overexpression of CD147 inhibited both early- and late-stages of apoptosis of CHO-CD147 cells, which is caused by serum deprivation. CHO-EGFP-CD147 cells showed an increased anchorage-independent growth compared with CHO-EGFP cells as detected by soft-agar colony formation assay. The tumors formed by CHO-CD147 cells in nude mice were larger and coupled with higher expression of proliferating cell nuclear antigen and Ki-67 than that of CHO cells. In conclusion, human CD147 overexpression induces malignant phenotype in CHO cells. © 2015 International Federation for Cell Biology.

  3. Hyperexpressed netrin-1promoted neural stem cells migration in mice after focal cerebral ischemia

    OpenAIRE

    Haiyan Lu; Xiaoyan Song; Feng Wang; Guodong Wang; Yuncheng Wu; Qiaoshu Wang; Yongting Wang; Guoyuan Yang; Zhijun Zhang

    2016-01-01

    Endogenous Netrin-1 (NT-1) protein was significantly increased after cerebral ischemia, which may participate in the repair after transient cerebral ischemic injury. In this work, we explored whether NT-1 can be steadily overexpressed by adeno-associated virus (AAV) and the exogenous NT-1 can promote neural stem cells migration from the subventricular zone (SVZ) region after cerebral ischemia. Adult CD-1 mice were injected stereotacticly with AAV carrying NT-1 gene (AAV-NT-1). Mice underwent ...

  4. VEGF promotes tumorigenesis and angiogenesis of human glioblastoma stem cells

    International Nuclear Information System (INIS)

    Oka, Naoki; Soeda, Akio; Inagaki, Akihito; Onodera, Masafumi; Maruyama, Hidekazu; Hara, Akira; Kunisada, Takahiro; Mori, Hideki; Iwama, Toru

    2007-01-01

    There is increasing evidence for the presence of cancer stem cells (CSCs) in malignant brain tumors, and these CSCs may play a pivotal role in tumor initiation, growth, and recurrence. Vascular endothelial growth factor (VEGF) promotes the proliferation of vascular endothelial cells (VECs) and the neurogenesis of neural stem cells. Using CSCs derived from human glioblastomas and a retrovirus expressing VEGF, we examined the effects of VEGF on the properties of CSCs in vitro and in vivo. Although VEGF did not affect the property of CSCs in vitro, the injection of mouse brains with VEGF-expressing CSCs led to the massive expansion of vascular-rich GBM, tumor-associated hemorrhage, and high morbidity, suggesting that VEGF promoted tumorigenesis via angiogenesis. These results revealed that VEGF induced the proliferation of VEC in the vascular-rich tumor environment, the so-called stem cell niche

  5. Enhanced expression of membrane proteins in E. coli with a PBAD promoter mutant: synergies with chaperone pathway engineering strategies

    Directory of Open Access Journals (Sweden)

    Nannenga Brent L

    2011-12-01

    Full Text Available Abstract Background Membrane proteins (MPs populate 20-30% of genomes sequenced to date and hold potential as therapeutic targets as well as for practical applications in bionanotechnology. However, MP toxicity and low yields in normally robust expression hosts such as E. coli has curtailed progress in our understanding of their structure and function. Results Using the seven transmembrane segments H. turkmenica deltarhodopsin (HtdR as a reporter, we isolated a spontaneous mutant in the arabinose-inducible PBAD promoter leading to improved cell growth and a twofold increase in the recovery of active HtdR at 37°C. A single transversion in a conserved region of the cyclic AMP receptor protein binding site caused the phenotype by reducing htdR transcript levels by 65%. When the mutant promoter was used in conjunction with a host lacking the molecular chaperone Trigger Factor (Δtig cells, toxicity was further suppressed and the amount of correctly folded HtdR was 4-fold that present in the membranes of control cells. More importantly, while improved growth barely compensated for the reduction in transcription rates when another polytopic membrane protein (N. pharonis sensory rhodopsin II was expressed under control of the mutant promoter in wild type cells, a 4-fold increase in productivity could be achieved in a Δtig host. Conclusions Our system, which combines a downregulated version of the tightly repressed PBAD promoter with a TF-deficient host may prove a valuable alternative to T7-based expression for the production of membrane proteins that have so far remained elusive targets.

  6. Histone deacetylase inhibitors epigenetically promote reparative events in primary dental pulp cells

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, Henry F., E-mail: Hal.Duncan@dental.tcd.ie [Division of Restorative Dentistry and Periodontology, Dublin Dental University Hospital, Trinity College Dublin, Lincoln Place, Dublin 2 (Ireland); Smith, Anthony J. [Oral Biology, School of Dentistry, College of Medical and Dental Sciences, University of Birmingham, Birmingham (United Kingdom); Fleming, Garry J.P. [Material Science Unit, Division of Oral Biosciences, Dublin Dental University Hospital, Trinity College Dublin, Dublin (Ireland); Cooper, Paul R. [Oral Biology, School of Dentistry, College of Medical and Dental Sciences, University of Birmingham, Birmingham (United Kingdom)

    2013-06-10

    Application of histone deacetylase inhibitors (HDACi) to cells epigenetically alters their chromatin structure and induces transcriptional and cellular reparative events. This study investigated the application of two HDACi, valproic acid (VPA) and trichostatin A (TSA) on the induction of repair-associated responses in primary dental pulp cell (DPC) cultures. Flow cytometry demonstrated that TSA (100 nM, 400 nM) significantly increased cell viability. Neither HDACi was cytotoxic, although cell growth analysis revealed significant anti-proliferative effects at higher concentrations for VPA (>0.5 mM) and TSA (>50 nM). While high-content-analysis demonstrated that HDACi did not significantly induce caspase-3 or p21 activity, p53-expression was increased by VPA (3 mM, 5 mM) at 48 h. HDACi-exposure induced mineralization per cell dose-dependently to a plateau level (VPA-0.125 mM and TSA-25 nM) with accompanying increases in mineralization/dentinogenic-associated gene expression at 5 days (DMP-1, BMP-2/-4, Nestin) and 10 days (DSPP, BMP-2/-4). Both HDACis, at a range of concentrations, significantly stimulated osteopontin and BMP-2 protein expression at 10 and 14 days further supporting the ability of HDACi to promote differentiation. HDACi exert different effects on primary compared with transformed DPCs and promote mineralization and differentiation events without cytotoxic effects. These novel data now highlight the potential in restorative dentistry for applying low concentrations of HDACi in vital pulp treatment. -- Highlights: • Valproic acid and trichostatin A promoted mineralization in primary pulp cells. • Cell viability, apoptosis, caspase-3, p21 unaltered; p53 increased by valproic acid. • Trichostatin A increased cell viability at 24 h at selected concentrations. • Altered cell toxicity and differentiation between primary and transformed cells. • HDACi-induced the differentiation marker proteins osteopontin and BMP-2.

  7. Histone deacetylase inhibitors epigenetically promote reparative events in primary dental pulp cells

    International Nuclear Information System (INIS)

    Duncan, Henry F.; Smith, Anthony J.; Fleming, Garry J.P.; Cooper, Paul R.

    2013-01-01

    Application of histone deacetylase inhibitors (HDACi) to cells epigenetically alters their chromatin structure and induces transcriptional and cellular reparative events. This study investigated the application of two HDACi, valproic acid (VPA) and trichostatin A (TSA) on the induction of repair-associated responses in primary dental pulp cell (DPC) cultures. Flow cytometry demonstrated that TSA (100 nM, 400 nM) significantly increased cell viability. Neither HDACi was cytotoxic, although cell growth analysis revealed significant anti-proliferative effects at higher concentrations for VPA (>0.5 mM) and TSA (>50 nM). While high-content-analysis demonstrated that HDACi did not significantly induce caspase-3 or p21 activity, p53-expression was increased by VPA (3 mM, 5 mM) at 48 h. HDACi-exposure induced mineralization per cell dose-dependently to a plateau level (VPA-0.125 mM and TSA-25 nM) with accompanying increases in mineralization/dentinogenic-associated gene expression at 5 days (DMP-1, BMP-2/-4, Nestin) and 10 days (DSPP, BMP-2/-4). Both HDACis, at a range of concentrations, significantly stimulated osteopontin and BMP-2 protein expression at 10 and 14 days further supporting the ability of HDACi to promote differentiation. HDACi exert different effects on primary compared with transformed DPCs and promote mineralization and differentiation events without cytotoxic effects. These novel data now highlight the potential in restorative dentistry for applying low concentrations of HDACi in vital pulp treatment. -- Highlights: • Valproic acid and trichostatin A promoted mineralization in primary pulp cells. • Cell viability, apoptosis, caspase-3, p21 unaltered; p53 increased by valproic acid. • Trichostatin A increased cell viability at 24 h at selected concentrations. • Altered cell toxicity and differentiation between primary and transformed cells. • HDACi-induced the differentiation marker proteins osteopontin and BMP-2

  8. Cellular promoters incorporated into the adenovirus genome: effects of viral regulatory elements on transcription rates and cell specificity of albumin and beta-globin promoters.

    OpenAIRE

    Babiss, L E; Friedman, J M; Darnell, J E

    1986-01-01

    In the accompanying paper (Friedman et al., Mol. Cell. Biol. 6:3791-3797, 1986), hepatoma-specific expression of the rat albumin promoter within the adenovirus genome was demonstrated. However, the rate of transcription was very low compared with that of the endogenous chromosomal albumin gene. Here we show that in hepatoma cells the adenovirus E1A enhancer, especially in the presence of E1A protein, greatly stimulates transcription from the albumin promoter but not the mouse beta-globin prom...

  9. Wnt-β-Catenin Signaling Promotes the Maturation of Mast Cells

    Directory of Open Access Journals (Sweden)

    Tomoko Yamaguchi

    2016-01-01

    Full Text Available Mast cells play an important role in the pathogenesis of allergic diseases. Immature mast cells migrate into peripheral tissues from the bone marrow and undergo complete maturation. Interestingly, mast cells have characteristics similar to hematopoietic stem cells (HSCs, such as self-renewal and c-kit expression. In HSCs, Wnt signaling is involved in their maintenance and differentiation. On the other hand, the relation between Wnt signaling and mast cell differentiation is poorly understood. To study whether Wnt signals play a role in the maturation of mast cells, we studied the effect of Wnt proteins on mast cell maturation of bone marrow-derived mast cells (BMMCs. The expression levels of CD81 protein and histidine decarboxylase mRNA and activity of mast cell-specific protease were all elevated in BMMCs treated with Wnt5a. In addition, Wnt5a induced the expression of Axin2 and TCF mRNA in BMMCs. These results showed that Wnt5a could promote the maturation of mast cells via the canonical Wnt signaling pathway and provide important insights into the molecular mechanisms underlying the differentiation of mast cells.

  10. Protein kinase activity of phosphoinositide 3-kinase regulates cytokine-dependent cell survival.

    Directory of Open Access Journals (Sweden)

    Daniel Thomas

    Full Text Available The dual specificity protein/lipid kinase, phosphoinositide 3-kinase (PI3K, promotes growth factor-mediated cell survival and is frequently deregulated in cancer. However, in contrast to canonical lipid-kinase functions, the role of PI3K protein kinase activity in regulating cell survival is unknown. We have employed a novel approach to purify and pharmacologically profile protein kinases from primary human acute myeloid leukemia (AML cells that phosphorylate serine residues in the cytoplasmic portion of cytokine receptors to promote hemopoietic cell survival. We have isolated a kinase activity that is able to directly phosphorylate Ser585 in the cytoplasmic domain of the interleukin 3 (IL-3 and granulocyte macrophage colony stimulating factor (GM-CSF receptors and shown it to be PI3K. Physiological concentrations of cytokine in the picomolar range were sufficient for activating the protein kinase activity of PI3K leading to Ser585 phosphorylation and hemopoietic cell survival but did not activate PI3K lipid kinase signaling or promote proliferation. Blockade of PI3K lipid signaling by expression of the pleckstrin homology of Akt1 had no significant impact on the ability of picomolar concentrations of cytokine to promote hemopoietic cell survival. Furthermore, inducible expression of a mutant form of PI3K that is defective in lipid kinase activity but retains protein kinase activity was able to promote Ser585 phosphorylation and hemopoietic cell survival in the absence of cytokine. Blockade of p110α by RNA interference or multiple independent PI3K inhibitors not only blocked Ser585 phosphorylation in cytokine-dependent cells and primary human AML blasts, but also resulted in a block in survival signaling and cell death. Our findings demonstrate a new role for the protein kinase activity of PI3K in phosphorylating the cytoplasmic tail of the GM-CSF and IL-3 receptors to selectively regulate cell survival highlighting the importance of targeting

  11. Delocalized Claudin-1 promotes metastasis of human osteosarcoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Jian, Yuekui; Chen, Changqiong; Li, Bo; Tian, Xiaobin, E-mail: drtxb_guiyang@sina.com

    2015-10-23

    Tight junction proteins (TJPs) including Claudins, Occludin and tight junction associated protein Zonula occludens-1 (ZO-1), are the most apical component of junctional complex that mediates cell–cell adhesion in epithelial and endothelial cells. In human malignancies, TJPs are often deregulated and affect cellular behaviors of tumor cells. In this study, we investigated alternations of TJPs and related biological characteristics in human osteosarcoma (OS). Claudin1 was increased in the metastatic OS cells (KRIB and KHOS) compared with the normal osteoblast cells (hFOB1.19) or primary tumor cells (HOS and U2OS), whereas no significant difference was found in Occludin and ZO-1. Immunohistochemistry, immunofluorescence and Western blotting revealed that Claudin1 was initially localized at cell junctions of normal osteoblasts, but substantially delocalized to the nucleus of metastatic OS cells. Phenotypically, inhibition of the nucleus Claudin1 expression compromised the metastatic potential of KRIB and KHOS cells. Moreover, we found that protein kinase C (PKC) but not PKA phosphorylation influenced Claudin1 expression and cellular functions, as PKC inhibitor (Go 6983 and Staurosporine) or genetic silencing of PKC reduced Claudin1 expression and decreased the motility of KRIB and KHOS cells. Taken together, our study implied that delocalization of claudin-1 induced by PKC phosphorylation contributes to metastatic capacity of OS cells. - Highlights: • Claudin1 is increased during the malignant transformation of human OS. • Delocalization of Claudin1 in metastatic OS cells. • Silencing nuclear Claudin1 expression inhibits cell invasion of OS. • Deregulated Claudin1 is regulated by PKC.

  12. Decellularized Matrix from Tumorigenic Human Mesenchymal Stem Cells Promotes Neovascularization with Galectin-1 Dependent Endothelial Interaction

    Science.gov (United States)

    Burns, Jorge S.; Kristiansen, Malthe; Kristensen, Lars P.; Larsen, Kenneth H.; Nielsen, Maria O.; Christiansen, Helle; Nehlin, Jan; Andersen, Jens S.; Kassem, Moustapha

    2011-01-01

    Background Acquisition of a blood supply is fundamental for extensive tumor growth. We recently described vascular heterogeneity in tumours derived from cell clones of a human mesenchymal stem cell (hMSC) strain (hMSC-TERT20) immortalized by retroviral vector mediated human telomerase (hTERT) gene expression. Histological analysis showed that cells of the most vascularized tumorigenic clone, -BD11 had a pericyte-like alpha smooth muscle actin (ASMA+) and CD146+ positive phenotype. Upon serum withdrawal in culture, -BD11 cells formed cord-like structures mimicking capillary morphogenesis. In contrast, cells of the poorly tumorigenic clone, -BC8 did not stain for ASMA, tumours were less vascularized and serum withdrawal in culture led to cell death. By exploring the heterogeneity in hMSC-TERT20 clones we aimed to understand molecular mechanisms by which mesenchymal stem cells may promote neovascularization. Methodology/Principal Findings Quantitative qRT-PCR analysis revealed similar mRNA levels for genes encoding the angiogenic cytokines VEGF and Angiopoietin-1 in both clones. However, clone-BD11 produced a denser extracellular matrix that supported stable ex vivo capillary morphogenesis of human endothelial cells and promoted in vivo neovascularization. Proteomic characterization of the -BD11 decellularized matrix identified 50 extracellular angiogenic proteins, including galectin-1. siRNA knock down of galectin-1 expression abrogated the ex vivo interaction between decellularized -BD11 matrix and endothelial cells. More stable shRNA knock down of galectin-1 expression did not prevent -BD11 tumorigenesis, but greatly reduced endothelial migration into -BD11 cell xenografts. Conclusions Decellularized hMSC matrix had significant angiogenic potential with at least 50 angiogenic cell surface and extracellular proteins, implicated in attracting endothelial cells, their adhesion and activation to form tubular structures. hMSC -BD11 surface galectin-1 expression was

  13. P-body proteins regulate transcriptional rewiring to promote DNA replication stress resistance.

    Science.gov (United States)

    Loll-Krippleber, Raphael; Brown, Grant W

    2017-09-15

    mRNA-processing (P-) bodies are cytoplasmic granules that form in eukaryotic cells in response to numerous stresses to serve as sites of degradation and storage of mRNAs. Functional P-bodies are critical for the DNA replication stress response in yeast, yet the repertoire of P-body targets and the mechanisms by which P-bodies promote replication stress resistance are unknown. In this study we identify the complete complement of mRNA targets of P-bodies during replication stress induced by hydroxyurea treatment. The key P-body protein Lsm1 controls the abundance of HHT1, ACF4, ARL3, TMA16, RRS1 and YOX1 mRNAs to prevent their toxic accumulation during replication stress. Accumulation of YOX1 mRNA causes aberrant downregulation of a network of genes critical for DNA replication stress resistance and leads to toxic acetaldehyde accumulation. Our data reveal the scope and the targets of regulation by P-body proteins during the DNA replication stress response.P-bodies form in response to stress and act as sites of mRNA storage and degradation. Here the authors identify the mRNA targets of P-bodies during DNA replication stress, and show that P-body proteins act to prevent toxic accumulation of these target transcripts.

  14. Armadillo Repeat Containing 8α Binds to HRS and Promotes HRS Interaction with Ubiquitinated Proteins

    Science.gov (United States)

    Tomaru, Koji; Ueda, Atsuhisa; Suzuki, Takeyuki; Kobayashi, Nobuaki; Yang, Jun; Yamamoto, Masaki; Takeno, Mitsuhiro; Kaneko, Takeshi; Ishigatsubo, Yoshiaki

    2010-01-01

    Recently, we reported that a complex with an essential role in the degradation of Fructose-1,6-bisphosphatase in yeast is well conserved in mammalian cells; we named this mammalian complex C-terminal to the Lissencephaly type-1-like homology (CTLH) complex. Although the function of the CTLH complex remains unclear, here we used yeast two-hybrid screening to isolate Hepatocyte growth factor-regulated tyrosine kinase substrate (HRS) as a protein binding to a key component of CTLH complex, Armadillo repeat containing 8 (ARMc8) α. The association was confirmed by a yeast two-hybrid assay and a co-immunoprecipitation assay. The proline-rich domain of HRS was essential for the association. As demonstrated through immunofluorescence microscopy, ARMc8α co-localized with HRS. ARMc8α promoted the interaction of HRS with various ubiquitinated proteins through the ubiquitin-interacting motif. These findings suggest that HRS mediates protein endosomal trafficking partly through its interaction with ARMc8α. PMID:20224683

  15. A protocatechuate biosensor for Pseudomonas putida KT2440 via promoter and protein evolution

    Directory of Open Access Journals (Sweden)

    Ramesh K. Jha

    2018-06-01

    Full Text Available Robust fluorescence-based biosensors are emerging as critical tools for high-throughput strain improvement in synthetic biology. Many biosensors are developed in model organisms where sophisticated synthetic biology tools are also well established. However, industrial biochemical production often employs microbes with phenotypes that are advantageous for a target process, and biosensors may fail to directly transition outside the host in which they are developed. In particular, losses in sensitivity and dynamic range of sensing often occur, limiting the application of a biosensor across hosts. Here we demonstrate the optimization of an Escherichia coli-based biosensor in a robust microbial strain for the catabolism of aromatic compounds, Pseudomonas putida KT2440, through a generalizable approach of modulating interactions at the protein-DNA interface in the promoter and the protein-protein dimer interface. The high-throughput biosensor optimization approach demonstrated here is readily applicable towards other allosteric regulators. Keywords: Whole cell biosensor, Aromatic catabolism, Transcription factor, PcaU, Shikimate

  16. NOR1 promotes hepatocellular carcinoma cell proliferation and migration through modulating the Notch signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    You, Kun; Sun, Peisheng; Yue, Zhongyi; Li, Jian; Xiong, Wancheng; Wang, Jianguo, E-mail: jianguowangjgw@163.com

    2017-03-15

    Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide. Previous studies have reported that the oxidored-nitro domain containing protein 1 (NOR1) is a novel tumor suppressor in several tumors. Recent evidence suggests that NOR1 is strongly expressed in HCC cells. However, its role and mechanism in HCC are unclear. In the current study, Western blot and qPCR detected strong NOR1 mRNA and protein expression in HepG2 and Hep3B cells. After transfection with NOR1 siRNA or pcDNA3.1-myc-his-NOR1, the proliferation and migration of HepG2 and Hep3B cells were analyzed in vitro. HepG2 or Hep3B cells overexpressing NOR1 showed an increased proliferation and migration, whereas siRNA-mediated silencing of NOR1 showed the opposite effect. Furthermore, NOR1 activated the Notch signaling pathway, indicated by increased levels of Notch1, NICD, Hes1, and Hey1 in protein. Importantly, the Notch inhibitor DAPT downregulated Notch activation and further enhanced siNOR1-induced reduction of cell proliferation and migration in HepG2 and Hep3B cells, whereas DAPT reversed the effect of NOR1 overexpression on cell proliferation and migration. In conclusion, these results indicate that NOR1 may be involved in the progression of HCC and thus may be a potential target for the treatment of liver cancer. - Highlights: • NOR1 expression is up-regulated in HCC cells. • NOR1 promotes the proliferation and migration of HCC cells. • NOR1 promotes the progression of HCC cells by activating Notch pathway.

  17. Notch Signaling in Prostate Cancer Cells Promotes Osteoblastic Metastasis

    Science.gov (United States)

    2017-06-01

    information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this...function and number while inducing osteoblast proliferation. Our results suggest that Notch signaling from cancer cells promotes osteoblastic...Participants and other collaborating organizations: I initiated collaboration with Dr. Evan Keller at University of Michigan to interrogate PCa bone

  18. Promotion of cancer cell invasiveness and metastasis emergence caused by olfactory receptor stimulation.

    Directory of Open Access Journals (Sweden)

    Guenhaël Sanz

    Full Text Available Olfactory receptors (ORs are expressed in the olfactory epithelium, where they detect odorants, but also in other tissues with additional functions. Some ORs are even overexpressed in tumor cells. In this study, we identified ORs expressed in enterochromaffin tumor cells by RT-PCR, showing that single cells can co-express several ORs. Some of the receptors identified were already reported in other tumors, but they are orphan (without known ligand, as it is the case for most of the hundreds of human ORs. Thus, genes coding for human ORs with known ligands were transfected into these cells, expressing functional heterologous ORs. The in vitro stimulation of these cells by the corresponding OR odorant agonists promoted cell invasion of collagen gels. Using LNCaP prostate cancer cells, the stimulation of the PSGR (Prostate Specific G protein-coupled Receptor, an endogenously overexpressed OR, by β-ionone, its odorant agonist, resulted in the same phenotypic change. We also showed the involvement of a PI3 kinase γ dependent signaling pathway in this promotion of tumor cell invasiveness triggered by OR stimulation. Finally, after subcutaneous inoculation of LNCaP cells into NSG immunodeficient mice, the in vivo stimulation of these cells by the PSGR agonist β-ionone significantly enhanced metastasis emergence and spreading.

  19. Nucleic acid and protein extraction from electropermeabilized E. coli cells on a microfluidic chip

    DEFF Research Database (Denmark)

    Matos, T.; Senkbeil, Silja; Mendonça, A.

    2013-01-01

    technique has been developed which is based on exposing E. coli cells to low voltages to allow extraction of nucleic acids and proteins. The flow-through electropermeability chip used consists of a microfluidic channel with integrated gold electrodes that promote cell envelope channel formation at low...

  20. Six1 promotes proliferation of pancreatic cancer cells via upregulation of cyclin D1 expression.

    Directory of Open Access Journals (Sweden)

    Zhaoming Li

    Full Text Available Six1 is one of the transcription factors that act as master regulators of development and are frequently dysregulated in cancers. However, the role of Six1 in pancreatic cancer is not clear. Here we show that the relative expression of Six1 mRNA is increased in pancreatic cancer and correlated with advanced tumor stage. In vitro functional assays demonstrate that forced overexpression of Six1 significantly enhances the growth rate and proliferation ability of pancreatic cancer cells. Knockdown of endogenous Six1 decreases the proliferation of these cells dramatically. Furthermore, Six1 promotes the growth of pancreatic cancer cells in a xenograft assay. We also show that the gene encoding cyclin D1 is a direct transcriptional target of Six1 in pancreatic cancer cells. Overexpression of Six1 upregulates cyclin D1 mRNA and protein, and significantly enhances the activity of the cyclin D1 promoter in PANC-1 cells. We demonstrate that Six1 promotes cell cycle progression and proliferation by upregulation of cyclin D1. These data suggest that Six1 is overexpressed in pancreatic cancer and may contribute to the increased cell proliferation through upregulation of cyclin D1.

  1. CacyBP/SIP promotes the proliferation of colon cancer cells.

    Directory of Open Access Journals (Sweden)

    Huihong Zhai

    Full Text Available CacyBP/SIP is a component of the ubiquitin pathway and is overexpressed in several transformed tumor tissues, including colon cancer, which is one of the most common cancers worldwide. It is unknown whether CacyBP/SIP promotes the proliferation of colon cancer cells. This study examined the expression level, subcellular localization, and binding activity of CacyBP/SIP in human colon cancer cells in the presence and absence of the hormone gastrin. We found that CacyBP/SIP was expressed in a high percentage of colon cancer cells, but not in normal colonic surface epithelium. CacyBP/SIP promoted the cell proliferation of colon cancer cells under both basal and gastrin stimulated conditions as shown by knockdown studies. Gastrin stimulation triggered the translocation of CacyBP/SIP to the nucleus, and enhanced interaction between CacyBP/SIP and SKP1, a key component of ubiquitination pathway which further mediated the proteasome-dependent degradation of p27kip1 protein. The gastrin induced reduction in p27kip1 was prevented when cells were treated with the proteasome inhibitor MG132. These results suggest that CacyBP/SIP may be promoting growth of colon cancer cells by enhancing ubiquitin-mediated degradation of p27kip1.

  2. Resveratrol inhibits myeloma cell growth, prevents osteoclast formation, and promotes osteoblast differentiation

    DEFF Research Database (Denmark)

    Boissy, Patrice; Andersen, Thomas L; Abdallah, Basem M

    2005-01-01

    , a challenge for treating multiple myeloma is discovering drugs targeting not only myeloma cells but also osteoclasts and osteoblasts. Because resveratrol (trans-3,4',5-trihydroxystilbene) is reported to display antitumor activities on a variety of human cancer cells, we investigated the effects...... of this natural compound on myeloma and bone cells. We found that resveratrol reduces dose-dependently the growth of myeloma cell lines (RPMI 8226 and OPM-2) by a mechanism involving cell apoptosis. In cultures of human primary monocytes, resveratrol inhibits dose-dependently receptor activator of nuclear factor......RNA and cell surface protein levels and a decrease of NFATc1 stimulation and NF-kappaB nuclear translocation, whereas the gene expression of c-fms, CD14, and CD11a is up-regulated. Finally, resveratrol promotes dose-dependently the expression of osteoblast markers like osteocalcin and osteopontin in human bone...

  3. Cellular Adhesion Promotes Prostate Cancer Cells Escape from Dormancy.

    Science.gov (United States)

    Ruppender, Nazanin; Larson, Sandy; Lakely, Bryce; Kollath, Lori; Brown, Lisha; Coleman, Ilsa; Coleman, Roger; Nguyen, Holly; Nelson, Peter S; Corey, Eva; Snyder, Linda A; Vessella, Robert L; Morrissey, Colm; Lam, Hung-Ming

    2015-01-01

    Dissemination of prostate cancer (PCa) cells to the bone marrow is an early event in the disease process. In some patients, disseminated tumor cells (DTC) proliferate to form active metastases after a prolonged period of undetectable disease known as tumor dormancy. Identifying mechanisms of PCa dormancy and reactivation remain a challenge partly due to the lack of in vitro models. Here, we characterized in vitro PCa dormancy-reactivation by inducing cells from three patient-derived xenograft (PDX) lines to proliferate through tumor cell contact with each other and with bone marrow stroma. Proliferating PCa cells demonstrated tumor cell-cell contact and integrin clustering by immunofluorescence. Global gene expression analyses on proliferating cells cultured on bone marrow stroma revealed a downregulation of TGFB2 in all of the three proliferating PCa PDX lines when compared to their non-proliferating counterparts. Furthermore, constitutive activation of myosin light chain kinase (MLCK), a downstream effector of integrin-beta1 and TGF-beta2, in non-proliferating cells promoted cell proliferation. This cell proliferation was associated with an upregulation of CDK6 and a downregulation of E2F4. Taken together, our data provide the first clinically relevant in vitro model to support cellular adhesion and downregulation of TGFB2 as a potential mechanism by which PCa cells may escape from dormancy. Targeting the TGF-beta2-associated mechanism could provide novel opportunities to prevent lethal PCa metastasis.

  4. Engineered mammalian cells for production of recombinant proteins

    DEFF Research Database (Denmark)

    2017-01-01

    The present invention relates to mammalian cells modified to provide for improved expression of a recombinant protein of interest. In particular, the invention relates to CHO cells and other host cells in which the expression of one or more endogenous secreted proteins has been disrupted, as well...... as to the preparation, identification and use of such cells in the production of recombinant proteins....

  5. Unconventional Protein Secretion in Animal Cells.

    Science.gov (United States)

    Ng, Fanny; Tang, Bor Luen

    2016-01-01

    All eukaryotic cells secrete a range of proteins in a constitutive or regulated manner through the conventional or canonical exocytic/secretory pathway characterized by vesicular traffic from the endoplasmic reticulum, through the Golgi apparatus, and towards the plasma membrane. However, a number of proteins are secreted in an unconventional manner, which are insensitive to inhibitors of conventional exocytosis and use a route that bypasses the Golgi apparatus. These include cytosolic proteins such as fibroblast growth factor 2 (FGF2) and interleukin-1β (IL-1β), and membrane proteins that are known to also traverse to the plasma membrane by a conventional process of exocytosis, such as α integrin and the cystic fibrosis transmembrane conductor (CFTR). Mechanisms underlying unconventional protein secretion (UPS) are actively being analyzed and deciphered, and these range from an unusual form of plasma membrane translocation to vesicular processes involving the generation of exosomes and other extracellular microvesicles. In this chapter, we provide an overview on what is currently known about UPS in animal cells.

  6. Passive acquisition of leukocyte proteins is associated with changes in phosphorylation of cellular proteins and cell-cell adhesion properties.

    OpenAIRE

    Tabibzadeh, S. S.; Kong, Q. F.; Kapur, S.

    1994-01-01

    In this report, we show that interaction of neoplastic epithelial cells with vesicles derived from leukocytes results in passive acquisition by tumor cells of a diverse group of leukocyte proteins. Vesicles shed from leukocytes were heterogeneous and exhibited the specific proteins expressed on leukocyte subsets. Accordingly, epithelial cells differentially acquired leukocyte proteins associated with vesicles. Ultrastructural localization demonstrated that acquired proteins were associated wi...

  7. Ginseng Berry Extract Promotes Maturation of Mouse Dendritic Cells.

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    Full Text Available Ginseng extract has been shown to possess certain anti-virus, anti-tumor and immune-activating effects. However, the immunostimulatory effect of ginseng berry extract (GB has been less well characterized. In this study, we investigated the effect of GB on the activation of mouse dendritic cells (DCs in vitro and in vivo. GB treatment induced up-regulation of co-stimulatory molecules in bone marrow-derived DCs (BMDCs. Interestingly, GB induced a higher degree of co-stimulatory molecule up-regulation than ginseng root extract (GR at the same concentrations. Moreover, in vivo administration of GB promoted up-regulation of CD86, MHC class I and MHC class II and production of IL-6, IL-12 and TNF-α in spleen DCs. GB also promoted the generation of Th1 and Tc1 cells. Furthermore, Toll like receptor 4 (TLR4 and myeloid differentiation primary response 88 (MyD88 signaling pathway were essential for DC activation induced by GB. In addition, GB strongly prompted the proliferation of ovalbumin (OVA-specific CD4 and CD8 T cells. Finally, GB induced DC activation in tumor-bearing mice and the combination of OVA and GB treatment inhibited B16-OVA tumor cell growth in C57BL/6 mice. These results demonstrate that GB is a novel tumor therapeutic vaccine adjuvant by promoting DC and T cell activation.

  8. Interaction of an IHF-like protein with the Rhizobium etli nifA promoter.

    Science.gov (United States)

    Benhassine, Traki; Fauvart, Maarten; Vanderleyden, Jos; Michiels, Jan

    2007-06-01

    The nifA gene fulfills an essential role in the regulation of nitrogen fixation genes in Rhizobium etli. Transcription analysis of the nifA gene, assessed using promoter deletions, indicated an oxygen-independent expression, threefold higher during symbiosis as compared with free-living conditions. Electrophoretic mobility shift assays using those nifA promoter deletion fragments, which were actively transcribed, demonstrated the specific interaction with R. etli cellular protein(s) resulting in the formation of two DNA-protein complexes. An interacting protein was purified by liquid chromatography on Heparin Sepharose and Mono S columns. The purified 12 kDa R. etli protein cross-reacted with antibodies directed against Escherichia coli integration host factor (IHF). Furthermore, purified E. coli IHF was able to specifically bind to the R. etli nifA promoter region. These results point to an as yet undisclosed function of IHF in the regulation of R. etli nifA expression.

  9. NCYM promotes calpain-mediated Myc-nick production in human MYCN-amplified neuroblastoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Shoji, Wataru [Division of Biochemistry and Innovative Cancer Therapeutics and Children' s Cancer Research Center, Chiba Cancer Center Research Institute, 666-2 Nitona, Chuo-ku, Chiba 260-8717 (Japan); Department of Pediatric Surgery, Graduate School of Medicine, Tohoku University, Sendai 980-8574 (Japan); Suenaga, Yusuke, E-mail: ysuenaga@chiba-cc.jp [Division of Biochemistry and Innovative Cancer Therapeutics and Children' s Cancer Research Center, Chiba Cancer Center Research Institute, 666-2 Nitona, Chuo-ku, Chiba 260-8717 (Japan); Cancer Genome Center, Chiba Cancer Center Research Institute, 666-2 Nitona, Chuo-ku, Chiba 260-8717 (Japan); Kaneko, Yoshiki; Islam, S.M. Rafiqul; Alagu, Jennifer [Division of Biochemistry and Innovative Cancer Therapeutics and Children' s Cancer Research Center, Chiba Cancer Center Research Institute, 666-2 Nitona, Chuo-ku, Chiba 260-8717 (Japan); Yokoi, Sana [Cancer Genome Center, Chiba Cancer Center Research Institute, 666-2 Nitona, Chuo-ku, Chiba 260-8717 (Japan); Nio, Masaki [Department of Pediatric Surgery, Graduate School of Medicine, Tohoku University, Sendai 980-8574 (Japan); Nakagawara, Akira, E-mail: nakagawara-a@koseikan.jp [Division of Biochemistry and Innovative Cancer Therapeutics and Children' s Cancer Research Center, Chiba Cancer Center Research Institute, 666-2 Nitona, Chuo-ku, Chiba 260-8717 (Japan)

    2015-06-05

    NCYM is a cis-antisense gene of MYCN and is amplified in human neuroblastomas. High NCYM expression is associated with poor prognoses, and the NCYM protein stabilizes MYCN to promote proliferation of neuroblastoma cells. However, the molecular mechanisms of NCYM in the regulation of cell survival have remained poorly characterized. Here we show that NCYM promotes cleavage of MYCN to produce the anti-apoptotic protein, Myc-nick, both in vitro and in vivo. NCYM and Myc-nick were induced at G2/M phase, and NCYM knockdown induced apoptotic cell death accompanied by Myc-nick downregulation. These results reveal a novel function of NCYM as a regulator of Myc-nick production in human neuroblastomas. - Highlights: • NCYM promotes cleavages of MYC and MYCN to produce Myc-nick in vitro. • NCYM increases Myc-nick production in MYCN-amplified neuroblastoma cells. • NCYM knockdown decreases Myc-nick production and induces apoptosis at G2/M phase.

  10. NCYM promotes calpain-mediated Myc-nick production in human MYCN-amplified neuroblastoma cells

    International Nuclear Information System (INIS)

    Shoji, Wataru; Suenaga, Yusuke; Kaneko, Yoshiki; Islam, S.M. Rafiqul; Alagu, Jennifer; Yokoi, Sana; Nio, Masaki; Nakagawara, Akira

    2015-01-01

    NCYM is a cis-antisense gene of MYCN and is amplified in human neuroblastomas. High NCYM expression is associated with poor prognoses, and the NCYM protein stabilizes MYCN to promote proliferation of neuroblastoma cells. However, the molecular mechanisms of NCYM in the regulation of cell survival have remained poorly characterized. Here we show that NCYM promotes cleavage of MYCN to produce the anti-apoptotic protein, Myc-nick, both in vitro and in vivo. NCYM and Myc-nick were induced at G2/M phase, and NCYM knockdown induced apoptotic cell death accompanied by Myc-nick downregulation. These results reveal a novel function of NCYM as a regulator of Myc-nick production in human neuroblastomas. - Highlights: • NCYM promotes cleavages of MYC and MYCN to produce Myc-nick in vitro. • NCYM increases Myc-nick production in MYCN-amplified neuroblastoma cells. • NCYM knockdown decreases Myc-nick production and induces apoptosis at G2/M phase

  11. Biological Evaluation of Single Cell Protein

    International Nuclear Information System (INIS)

    Hasan, I.A.; Mohamed, N.E.; El-Sayed, E.A.; Younis, N.A.

    2011-01-01

    In this study, the nutritional value of single cell protein (SCP) was evaluated as a non conventional protein source produced by fermenting fungal local strains of Trichoderma longibrachiatum, Aspergillus niger, Aspergillus terreus and Penicillium funiculosum with alkali treated sugar cane bagasse. Amino acid analysis revealed that the produced SCP contains essential and non essential amino acids. Male mice were fed on normal (basal) diet which contains 18% conventional protein and served as control group. In the second (T1) and the third (T2) group, the animals were fed on a diet in which 15% and 30% of conventional protein source were replaced by SCP, respectively. At intervals of 15, 30, 45 and 60 days, mice were sacrificed and the blood samples were collected for the biochemical evaluation. The daily averages of body weight were significantly higher with group T2 than group T1. Where as, the kidney weights in groups (T1) and (T2) were significantly increased as compared with control. A non significant difference between the tested groups in the enzyme activities of AST, ALT and GSH content of liver tissue were recorded. While, cholesterol and triglycerides contents showed a significant decrease in both (T1) and (T2) groups as compared with control. The recorded values of the serum hormone (T4), ALP activities, albumin and A/G ratio did not changed by the previous treatments. Serum levels of total protein, urea, creatinine and uric acid were higher for groups (T1) and (T2) than the control group. In conclusion, partial substitution of soy bean protein in mice diet with single cell protein (15%) improved the mice growth without any adverse effects on some of the physiological functions tested

  12. Artificial acceleration of mammalian cell reprogramming by bacterial proteins.

    Science.gov (United States)

    Ikeda, Takashi; Uchiyama, Ikuo; Iwasaki, Mio; Sasaki, Tetsuhiko; Nakagawa, Masato; Okita, Keisuke; Masui, Shinji

    2017-10-01

    The molecular mechanisms of cell reprogramming and differentiation involve various signaling factors. Small molecule compounds have been identified to artificially influence these factors through interacting cellular proteins. Although such small molecule compounds are useful to enhance reprogramming and differentiation and to show the mechanisms that underlie these events, the screening usually requires a large number of compounds to identify only a very small number of hits (e.g., one hit among several tens of thousands of compounds). Here, we show a proof of concept that xenospecific gene products can affect the efficiency of cell reprogramming to pluripotency. Thirty genes specific for the bacterium Wolbachia pipientis were forcibly expressed individually along with reprogramming factors (Oct4, Sox2, Klf4 and c-Myc) that can generate induced pluripotent stem cells in mammalian cells, and eight were found to affect the reprogramming efficiency either positively or negatively (hit rate 26.7%). Mechanistic analysis suggested one of these proteins interacted with cytoskeleton to promote reprogramming. Our results raise the possibility that xenospecific gene products provide an alternative way to study the regulatory mechanism of cell identity. © 2017 Molecular Biology Society of Japan and John Wiley & Sons Australia, Ltd.

  13. An Aphid Effector Targets Trafficking Protein VPS52 in a Host-Specific Manner to Promote Virulence1[OPEN

    Science.gov (United States)

    2017-01-01

    Plant- and animal-feeding insects secrete saliva inside their hosts, containing effectors, which may promote nutrient release and suppress immunity. Although for plant pathogenic microbes it is well established that effectors target host proteins to modulate host cell processes and promote disease, the host cell targets of herbivorous insects remain elusive. Here, we show that the existing plant pathogenic microbe effector paradigm can be extended to herbivorous insects in that effector-target interactions inside host cells modify critical host processes to promote plant susceptibility. We showed that the effector Mp1 from Myzus persicae associates with the host Vacuolar Protein Sorting Associated Protein52 (VPS52). Using natural variants, we provide a strong link between effector virulence activity and association with VPS52, and show that the association is highly specific to M. persicae-host interactions. Also, coexpression of Mp1, but not Mp1-like variants, specifically with host VPS52s resulted in effector relocalization to vesicle-like structures that associate with prevacuolar compartments. We show that high VPS52 levels negatively impact virulence, and that aphids are able to reduce VPS52 levels during infestation, indicating that VPS52 is an important virulence target. Our work is an important step forward in understanding, at the molecular level, how a major agricultural pest promotes susceptibility during infestation of crop plants. We give evidence that an herbivorous insect employs effectors that interact with host proteins as part of an effective virulence strategy, and that these effectors likely function in a species-specific manner. PMID:28100451

  14. An Aphid Effector Targets Trafficking Protein VPS52 in a Host-Specific Manner to Promote Virulence.

    Science.gov (United States)

    Rodriguez, Patricia A; Escudero-Martinez, Carmen; Bos, Jorunn I B

    2017-03-01

    Plant- and animal-feeding insects secrete saliva inside their hosts, containing effectors, which may promote nutrient release and suppress immunity. Although for plant pathogenic microbes it is well established that effectors target host proteins to modulate host cell processes and promote disease, the host cell targets of herbivorous insects remain elusive. Here, we show that the existing plant pathogenic microbe effector paradigm can be extended to herbivorous insects in that effector-target interactions inside host cells modify critical host processes to promote plant susceptibility. We showed that the effector Mp1 from Myzus persicae associates with the host Vacuolar Protein Sorting Associated Protein52 (VPS52). Using natural variants, we provide a strong link between effector virulence activity and association with VPS52, and show that the association is highly specific to M persicae -host interactions. Also, coexpression of Mp1, but not Mp1-like variants, specifically with host VPS52s resulted in effector relocalization to vesicle-like structures that associate with prevacuolar compartments. We show that high VPS52 levels negatively impact virulence, and that aphids are able to reduce VPS52 levels during infestation, indicating that VPS52 is an important virulence target. Our work is an important step forward in understanding, at the molecular level, how a major agricultural pest promotes susceptibility during infestation of crop plants. We give evidence that an herbivorous insect employs effectors that interact with host proteins as part of an effective virulence strategy, and that these effectors likely function in a species-specific manner. © 2017 American Society of Plant Biologists. All Rights Reserved.

  15. Osteogenic differentiation of mouse mesenchymal progenitor cell, Kusa-A1 is promoted by mammalian transcriptional repressor Rbpj

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shengchao [Department of Preventive Dentistry, School of Stomatology, The Fourth Military Medical University, 145 West Changle Road, 710032 Xi' an (China); Kawashima, Nobuyuki, E-mail: kawashima.n.endo@tmd.ac.jp [Department of Pulp Biology and Endodontics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549 (Japan); Sakamoto, Kei; Katsube, Ken-ichi [Department of Oral Pathology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549 (Japan); Umezawa, Akihiro [Department of Reproductive Biology and Pathology, National Institute for Child Health and Development, 2-10-4 Ohkura, Setagaya-ku, Tokyo 157-8535 (Japan); Suda, Hideaki [Department of Pulp Biology and Endodontics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549 (Japan); GCOE Program, International Research Center for Molecular Science in Tooth and Bone Diseases, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549 (Japan)

    2010-09-10

    Research highlights: {yields} High Rbpj mRNA expression was observed in mesenchymal cells surrounding the bone of mouse embryos. {yields} Overexpression of Rbpj depressed Notch-Hes1/Hey1 signaling. {yields} Rbpj upregulated promoter activities of Runx2 and Ose2. {yields} Rbpj promoted osteoblastic differentiation/maturation in Kusa-A1 cells. -- Abstract: Pluripotent mesenchymal stem cells possess the ability to differentiate into many cell types, but the precise mechanisms of differentiation are still unclear. Here, we provide evidence that Rbpj (recombination signal-binding protein for immunoglobulin kappa j region) protein, the primary nuclear mediator of Notch, is involved in osteogenesis. Overexpression of Rbpj promoted osteogenic differentiation of mouse Kusa-A1 cells in vitro and in vivo. Transient transfection of an Rbpj expression vector into Kusa-A1 cells upregulated promoter activities of Runx2 and Ose2. Enhanced osteogenic potentials including high alkaline phosphatase activity, rapid calcium deposition, and increased calcified nodule formation, were observed in established stable Rbpj-overexpressing Kusa-A1 (Kusa-A1/Rbpj) cell line. In vivo mineralization by Kusa-A1/Rbpj was promoted compared to that by Kusa-A1 host cells. Histological findings revealed that expression of Rbpj was primarily observed in osteoblasts. These results suggest that Rbpj may play essential roles in osteoblast differentiation.

  16. Osteogenic differentiation of mouse mesenchymal progenitor cell, Kusa-A1 is promoted by mammalian transcriptional repressor Rbpj

    International Nuclear Information System (INIS)

    Wang, Shengchao; Kawashima, Nobuyuki; Sakamoto, Kei; Katsube, Ken-ichi; Umezawa, Akihiro; Suda, Hideaki

    2010-01-01

    Research highlights: → High Rbpj mRNA expression was observed in mesenchymal cells surrounding the bone of mouse embryos. → Overexpression of Rbpj depressed Notch-Hes1/Hey1 signaling. → Rbpj upregulated promoter activities of Runx2 and Ose2. → Rbpj promoted osteoblastic differentiation/maturation in Kusa-A1 cells. -- Abstract: Pluripotent mesenchymal stem cells possess the ability to differentiate into many cell types, but the precise mechanisms of differentiation are still unclear. Here, we provide evidence that Rbpj (recombination signal-binding protein for immunoglobulin kappa j region) protein, the primary nuclear mediator of Notch, is involved in osteogenesis. Overexpression of Rbpj promoted osteogenic differentiation of mouse Kusa-A1 cells in vitro and in vivo. Transient transfection of an Rbpj expression vector into Kusa-A1 cells upregulated promoter activities of Runx2 and Ose2. Enhanced osteogenic potentials including high alkaline phosphatase activity, rapid calcium deposition, and increased calcified nodule formation, were observed in established stable Rbpj-overexpressing Kusa-A1 (Kusa-A1/Rbpj) cell line. In vivo mineralization by Kusa-A1/Rbpj was promoted compared to that by Kusa-A1 host cells. Histological findings revealed that expression of Rbpj was primarily observed in osteoblasts. These results suggest that Rbpj may play essential roles in osteoblast differentiation.

  17. Soy protein isolate inhibits hepatic tumor promotion in mice fed a high-fat liquid diet.

    Science.gov (United States)

    Mercer, Kelly E; Pulliam, Casey F; Pedersen, Kim B; Hennings, Leah; Ronis, Martin Jj

    2017-03-01

    Alcoholic and nonalcoholic fatty liver diseases are risk factors for development of hepatocellular carcinoma, but the underlying mechanisms are poorly understood. On the other hand, ingestion of soy-containing diets may oppose the development of certain cancers. We previously reported that replacing casein with a soy protein isolate reduced tumor promotion in the livers of mice with alcoholic liver disease after feeding a high fat ethanol liquid diet following initiation with diethylnitrosamine. Feeding soy protein isolate inhibited processes that may contribute to tumor promotion including inflammation, sphingolipid signaling, and Wnt/β-catenin signaling. We have extended these studies to characterize liver tumor promotion in a model of nonalcoholic fatty liver disease produced by chronic feeding of high-fat liquid diets in the absence of ethanol. Mice treated with diethylnitrosamine on postnatal day 14 were fed a high-fat liquid diet made with casein or SPI as the sole protein source for 16 weeks in adulthood. Relative to mice fed normal chow, a high fat/casein diet led to increased tumor promotion, hepatocyte proliferation, steatosis, and inflammation. Replacing casein with soy protein isolate counteracted these effects. The high fat diets also resulted in a general increase in transcripts for Wnt/β-catenin pathway components, which may be an important mechanism, whereby hepatic tumorigenesis is promoted. However, soy protein isolate did not block Wnt signaling in this nonalcoholic fatty liver disease model. We conclude that replacing casein with soy protein isolate blocks development of steatosis, inflammation, and tumor promotion in diethylnitrosamine-treated mice fed high fat diets. Impact statement The impact of dietary components on cancer is a topic of great interest for both the general public and the scientific community. Liver cancer is currently the second leading form of cancer deaths worldwide. Our study has addressed the effect of the protein

  18. Merkel cell polyomavirus recruits MYCL to the EP400 complex to promote oncogenesis.

    Directory of Open Access Journals (Sweden)

    Jingwei Cheng

    2017-10-01

    Full Text Available Merkel cell carcinoma (MCC frequently contains integrated copies of Merkel cell polyomavirus DNA that express a truncated form of Large T antigen (LT and an intact Small T antigen (ST. While LT binds RB and inactivates its tumor suppressor function, it is less clear how ST contributes to MCC tumorigenesis. Here we show that ST binds specifically to the MYC homolog MYCL (L-MYC and recruits it to the 15-component EP400 histone acetyltransferase and chromatin remodeling complex. We performed a large-scale immunoprecipitation for ST and identified co-precipitating proteins by mass spectrometry. In addition to protein phosphatase 2A (PP2A subunits, we identified MYCL and its heterodimeric partner MAX plus the EP400 complex. Immunoprecipitation for MAX and EP400 complex components confirmed their association with ST. We determined that the ST-MYCL-EP400 complex binds together to specific gene promoters and activates their expression by integrating chromatin immunoprecipitation with sequencing (ChIP-seq and RNA-seq. MYCL and EP400 were required for maintenance of cell viability and cooperated with ST to promote gene expression in MCC cell lines. A genome-wide CRISPR-Cas9 screen confirmed the requirement for MYCL and EP400 in MCPyV-positive MCC cell lines. We demonstrate that ST can activate gene expression in a EP400 and MYCL dependent manner and this activity contributes to cellular transformation and generation of induced pluripotent stem cells.

  19. Merkel cell polyomavirus recruits MYCL to the EP400 complex to promote oncogenesis.

    Science.gov (United States)

    Cheng, Jingwei; Park, Donglim Esther; Berrios, Christian; White, Elizabeth A; Arora, Reety; Yoon, Rosa; Branigan, Timothy; Xiao, Tengfei; Westerling, Thomas; Federation, Alexander; Zeid, Rhamy; Strober, Benjamin; Swanson, Selene K; Florens, Laurence; Bradner, James E; Brown, Myles; Howley, Peter M; Padi, Megha; Washburn, Michael P; DeCaprio, James A

    2017-10-01

    Merkel cell carcinoma (MCC) frequently contains integrated copies of Merkel cell polyomavirus DNA that express a truncated form of Large T antigen (LT) and an intact Small T antigen (ST). While LT binds RB and inactivates its tumor suppressor function, it is less clear how ST contributes to MCC tumorigenesis. Here we show that ST binds specifically to the MYC homolog MYCL (L-MYC) and recruits it to the 15-component EP400 histone acetyltransferase and chromatin remodeling complex. We performed a large-scale immunoprecipitation for ST and identified co-precipitating proteins by mass spectrometry. In addition to protein phosphatase 2A (PP2A) subunits, we identified MYCL and its heterodimeric partner MAX plus the EP400 complex. Immunoprecipitation for MAX and EP400 complex components confirmed their association with ST. We determined that the ST-MYCL-EP400 complex binds together to specific gene promoters and activates their expression by integrating chromatin immunoprecipitation with sequencing (ChIP-seq) and RNA-seq. MYCL and EP400 were required for maintenance of cell viability and cooperated with ST to promote gene expression in MCC cell lines. A genome-wide CRISPR-Cas9 screen confirmed the requirement for MYCL and EP400 in MCPyV-positive MCC cell lines. We demonstrate that ST can activate gene expression in a EP400 and MYCL dependent manner and this activity contributes to cellular transformation and generation of induced pluripotent stem cells.

  20. Lipid raft association restricts CD44-ezrin interaction and promotion of breast cancer cell migration.

    LENUS (Irish Health Repository)

    Donatello, Simona

    2012-12-01

    Cancer cell migration is an early event in metastasis, the main cause of breast cancer-related deaths. Cholesterol-enriched membrane domains called lipid rafts influence the function of many molecules, including the raft-associated protein CD44. We describe a novel mechanism whereby rafts regulate interactions between CD44 and its binding partner ezrin in migrating breast cancer cells. Specifically, in nonmigrating cells, CD44 and ezrin localized to different membranous compartments: CD44 predominantly in rafts, and ezrin in nonraft compartments. After the induction of migration (either nonspecific or CD44-driven), CD44 affiliation with lipid rafts was decreased. This was accompanied by increased coprecipitation of CD44 and active (threonine-phosphorylated) ezrin-radixin-moesin (ERM) proteins in nonraft compartments and increased colocalization of CD44 with the nonraft protein, transferrin receptor. Pharmacological raft disruption using methyl-β-cyclodextrin also increased CD44-ezrin coprecipitation and colocalization, further suggesting that CD44 interacts with ezrin outside rafts during migration. Conversely, promoting CD44 retention inside lipid rafts by pharmacological inhibition of depalmitoylation virtually abolished CD44-ezrin interactions. However, transient single or double knockdown of flotillin-1 or caveolin-1 was not sufficient to increase cell migration over a short time course, suggesting complex crosstalk mechanisms. We propose a new model for CD44-dependent breast cancer cell migration, where CD44 must relocalize outside lipid rafts to drive cell migration. This could have implications for rafts as pharmacological targets to down-regulate cancer cell migration.

  1. The cancer-promoting gene fatty acid-binding protein 5 (FABP5) is epigenetically regulated during human prostate carcinogenesis.

    Science.gov (United States)

    Kawaguchi, Koichiro; Kinameri, Ayumi; Suzuki, Shunsuke; Senga, Shogo; Ke, Youqiang; Fujii, Hiroshi

    2016-02-15

    FABPs (fatty-acid-binding proteins) are a family of low-molecular-mass intracellular lipid-binding proteins consisting of ten isoforms. FABPs are involved in binding and storing hydrophobic ligands such as long-chain fatty acids, as well as transporting these ligands to the appropriate compartments in the cell. FABP5 is overexpressed in multiple types of tumours. Furthermore, up-regulation of FABP5 is strongly associated with poor survival in triple-negative breast cancer. However, the mechanisms underlying the specific up-regulation of the FABP5 gene in these cancers remain poorly characterized. In the present study, we determined that FABP5 has a typical CpG island around its promoter region. The DNA methylation status of the CpG island in the FABP5 promoter of benign prostate cells (PNT2), prostate cancer cells (PC-3, DU-145, 22Rv1 and LNCaP) and human normal or tumour tissue was assessed by bisulfite sequencing analysis, and then confirmed by COBRA (combined bisulfite restriction analysis) and qAMP (quantitative analysis of DNA methylation using real-time PCR). These results demonstrated that overexpression of FABP5 in prostate cancer cells can be attributed to hypomethylation of the CpG island in its promoter region, along with up-regulation of the direct trans-acting factors Sp1 (specificity protein 1) and c-Myc. Together, these mechanisms result in the transcriptional activation of FABP5 expression during human prostate carcinogenesis. Importantly, silencing of Sp1, c-Myc or FABP5 expression led to a significant decrease in cell proliferation, indicating that up-regulation of FABP5 expression by Sp1 and c-Myc is critical for the proliferation of prostate cancer cells. © 2016 Authors; published by Portland Press Limited.

  2. Triiodothyronine promotes the proliferation of epicardial progenitor cells through the MAPK/ERK pathway.

    Science.gov (United States)

    Deng, Song-Bai; Jing, Xiao-Dong; Wei, Xiao-Ming; Du, Jian-Lin; Liu, Ya-Jie; Qin, Qin; She, Qiang

    2017-04-29

    Thyroid hormone has important functions in the development and physiological function of the heart. The aim of this study was to determine whether 3,5,3'-Triiodothyronine (T3) can promote the proliferation of epicardial progenitor cells (EPCs) and to investigate the potential underlying mechanism. Our results showed that T3 significantly promoted the proliferation of EPCs in a concentration- and time-dependent manner. The thyroid hormone nuclear receptor inhibitor bisphenol A (100 μmol/L) did not affect T3's ability to induce proliferation. Further studies showed that the mRNA expression levels of mitogen-activated protein kinase 1 (MAPK1), MAPK3, and Ki67 in EPCs in the T3 group (10 nmol/L) increased 2.9-, 3-, and 4.1-fold, respectively, compared with those in the control group (P < 0.05). In addition, the mRNA expression of the cell cycle protein cyclin D1 in the T3 group increased approximately 2-fold compared with the control group (P < 0.05), and there were more EPCs in the S phase of the cell cycle (20.6% vs. 12.0%, P < 0.05). The mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) signaling pathway inhibitor U0126 (10 μmol/L) significantly inhibited the ability of T3 to promote the proliferation of EPCs and to alter cell cycle progression. This study suggested that T3 significantly promotes the proliferation of EPCs, and this effect may be achieved through activation of the MAPK/ERK signaling pathway. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Omeprazole blocks STAT6 binding to the eotaxin-3 promoter in eosinophilic esophagitis cells.

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    Xi Zhang

    Full Text Available Patients who have esophageal eosinophilia without gastroesophageal reflux disease (GERD nevertheless can respond to proton pump inhibitors (PPIs, which can have anti-inflammatory actions independent of effects on gastric acid secretion. In esophageal cell cultures, omeprazole has been reported to inhibit Th2 cytokine-stimulated expression of eotaxin-3, an eosinophil chemoattractant contributing to esophageal eosinophilia in eosinophilic esophagitis (EoE. The objective of this study was to elucidate molecular mechanisms underlying PPI inhibition of IL-4-stimulated eotaxin-3 production by esophageal cells.Telomerase-immortalized and primary cultures of esophageal squamous cells from EoE patients were treated with IL-4 in the presence or absence of acid-activated omeprazole or lansoprazole. We measured eotaxin-3 protein secretion by ELISA, mRNA expression by PCR, STAT6 phosphorylation and nuclear translocation by Western blotting, eotaxin-3 promoter activation by an exogenous reporter construct, and STAT6, RNA polymerase II, and trimethylated H3K4 binding to the endogenous eotaxin-3 promoter by ChIP assay. Omeprazole in concentrations ≥5 µM significantly decreased IL-4-stimulated eotaxin-3 protein secretion and mRNA expression. Lansoprazole also blocked eotaxin-3 protein secretion. Omeprazole had no effect on eotaxin-3 mRNA stability or on STAT6 phosphorylation and STAT6 nuclear translocation. Rather, omeprazole blocked binding of IL-4-stimulated STAT6, RNA polymerase II, and trimethylated H3K4 to the eotaxin-3 promoter.PPIs, in concentrations achieved in blood with conventional dosing, significantly inhibit IL-4-stimulated eotaxin-3 expression in EoE esophageal cells and block STAT6 binding to the promoter. These findings elucidate molecular mechanisms whereby patients with Th2 cytokine-driven esophageal eosinophilia can respond to PPIs, independent of effects on gastric acid secretion.

  4. Silk-based biomaterials functionalized with fibronectin type II promotes cell adhesion.

    Science.gov (United States)

    Pereira, Ana Margarida; Machado, Raul; da Costa, André; Ribeiro, Artur; Collins, Tony; Gomes, Andreia C; Leonor, Isabel B; Kaplan, David L; Reis, Rui L; Casal, Margarida

    2017-01-01

    The objective of this work was to exploit the fibronectin type II (FNII) module from human matrix metalloproteinase-2 as a functional domain for the development of silk-based biopolymer blends that display enhanced cell adhesion properties. The DNA sequence of spider dragline silk protein (6mer) was genetically fused with the FNII coding sequence and expressed in Escherichia coli. The chimeric protein 6mer+FNII was purified by non-chromatographic methods. Films prepared from 6mer+FNII by solvent casting promoted only limited cell adhesion of human skin fibroblasts. However, the performance of the material in terms of cell adhesion was significantly improved when 6mer+FNII was combined with a silk-elastin-like protein in a concentration-dependent behavior. With this work we describe a novel class of biopolymer that promote cell adhesion and potentially useful as biomaterials for tissue engineering and regenerative medicine. This work reports the development of biocompatible silk-based composites with enhanced cell adhesion properties suitable for biomedical applications in regenerative medicine. The biocomposites were produced by combining a genetically engineered silk-elastin-like protein with a genetically engineered spider-silk-based polypeptide carrying the three domains of the fibronectin type II module from human metalloproteinase-2. These composites were processed into free-standing films by solvent casting and characterized for their biological behavior. To our knowledge this is the first report of the exploitation of all three FNII domains as a functional domain for the development of bioinspired materials with improved biological performance. The present study highlights the potential of using genetically engineered protein-based composites as a platform for the development of new bioinspired biomaterials. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  5. Mammalian-enabled (MENA) protein enhances oncogenic potential and cancer stem cell-like phenotype in hepatocellular carcinoma cells.

    Science.gov (United States)

    Hu, Kunpeng; Huang, Pinzhu; Luo, Hui; Yao, Zhicheng; Wang, Qingliang; Xiong, Zhiyong; Lin, Jizong; Huang, He; Xu, Shilei; Zhang, Peng; Liu, Bo

    2017-08-01

    Mammalian-enabled (MENA) protein is an actin-regulatory protein that influences cell motility and adhesion. It is known to play a role in tumorigenicity of hepatocellular carcinoma (HCC) but the underlying molecular mechanism remains unknown. This study aimed to investigate the oncogenic potential of MENA and its capacity to regulate cancer stem cell (CSC)-like phenotypes in HCC cells. Real-time-PCR and western blot were used to assess mRNA and protein levels of target genes in human HCC tissue specimens and HCC cell lines, respectively. Stable MENA-overexpressing HCC cells were generated from HCC cell lines. Transwell cell migration and colony formation assays were employed to evaluate tumorigenicity. Ectopic expression of MENA significantly enhanced cell migration and colony-forming ability in HCC cells. Overexpression of MENA upregulated several hepatic progenitor/stem cell markers in HCC cells. A high MENA protein level was associated with high mRNA levels of MENA, CD133, cytokeratin 19 (CK19), and epithelial cell adhesion molecule (EpCAM) in human HCC tissues. Overexpression of MENA enhanced epithelial-to-mesenchymal transition (EMT) markers, extracellular signal-regulated kinases (ERK) phosphorylation, and the level of β-catenin in HCC cells. This study demonstrated that overexpression of MENA in HCC cells promoted stem cell markers, EMT markers, and tumorigenicity. These effects may involve, at least partially, the ERK and β-catenin signaling pathways.

  6. High-level extracellular protein production in Bacillus subtilis using an optimized dual-promoter expression system.

    Science.gov (United States)

    Zhang, Kang; Su, Lingqia; Duan, Xuguo; Liu, Lina; Wu, Jing

    2017-02-20

    We recently constructed a Bacillus subtilis strain (CCTCC M 2016536) from which we had deleted the srfC, spoIIAC, nprE, aprE and amyE genes. This strain is capable of robust recombinant protein production and amenable to high-cell-density fermentation. Because the promoter is among the factors that influence the production of target proteins, optimization of the initial promoter, P amyQ from Bacillus amyloliquefaciens, should improve protein expression using this strain. This study was undertaken to develop a new, high-level expression system in B. subtilis CCTCC M 2016536. Using the enzyme β-cyclodextrin glycosyltransferase (β-CGTase) as a reporter protein and B. subtilis CCTCC M 2016536 as the host, nine plasmids equipped with single promoters were screened using shake-flask cultivation. The plasmid containing the P amyQ' promoter produced the greatest extracellular β-CGTase activity; 24.1 U/mL. Subsequently, six plasmids equipped with dual promoters were constructed and evaluated using this same method. The plasmid containing the dual promoter P HpaII -P amyQ' produced the highest extracellular β-CGTase activity (30.5 U/mL) and was relatively glucose repressed. The dual promoter P HpaII -P amyQ' also mediated substantial extracellular pullulanase (90.7 U/mL) and α-CGTase expression (9.5 U/mL) during shake-flask cultivation, demonstrating the general applicability of this system. Finally, the production of β-CGTase using the dual-promoter P HpaII -P amyQ' system was investigated in a 3-L fermenter. Extracellular expression of β-CGTase reached 571.2 U/mL (2.5 mg/mL), demonstrating the potential of this system for use in industrial applications. The dual-promoter P HpaII -P amyQ' system was found to support superior expression of extracellular proteins in B. subtilis CCTCC M 2016536. This system appears generally applicable and is amenable to scale-up.

  7. Adipose-derived mesenchymal stem cells promote cell proliferation and invasion of epithelial ovarian cancer

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    Chu, Yijing; Tang, Huijuan; Guo, Yan; Guo, Jing; Huang, Bangxing; Fang, Fang; Cai, Jing, E-mail: caijingmmm@hotmail.com; Wang, Zehua, E-mail: zehuawang@163.net

    2015-09-10

    Adipose-derived mesenchymal stem cell (ADSC) is an important component of tumor microenvironment. However, whether ADSCs have a hand in ovarian cancer progression remains unclear. In this study, we investigated the impact of human ADSCs derived from the omentum of normal donors on human epithelial ovarian cancer (EOC) cells in vitro and in vivo. Direct and indirect co-culture models including ADSCs and human EOC cell lines were established and the effects of ADSCs on EOC cell proliferation were evaluated by EdU incorporation and flow cytometry. Transwell migration assays and detection of MMPs were performed to assess the invasion activity of EOC cells in vitro. Mouse models were established by intraperitoneal injection of EOC cells with or without concomitant ADSCs to investigate the role of ADSCs in tumor progression in vivo. We found that ADSCs significantly promoted proliferation and invasion of EOC cells in both direct and indirect co-culture assays. In addition, after co-culture with ADSCs, EOC cells secreted higher levels of matrix metalloproteinases (MMPs), and inhibition of MMP2 and MMP9 partially relieved the tumor-promoting effects of ADSCs in vitro. In mouse xenograft models, we confirmed that ADSCs promoted EOC growth and metastasis and elevated the expression of MMP2 and MMP9. Our findings indicate that omental ADSCs play a promotive role during ovarian cancer progression. - Highlights: • Omental adipose derived stem cells enhanced growth and invasion properties of ovarian cancer cells. • Adipose derived stem cells promoted the growth and metastasis of ovarian cancer in mice models. • Adipose derived stem cells promoted MMPs expression and secretion of ovarian cancer cells. • Elevated MMPs mediated the tumor promoting effects of ADSCs.

  8. Adipose-derived mesenchymal stem cells promote cell proliferation and invasion of epithelial ovarian cancer

    International Nuclear Information System (INIS)

    Chu, Yijing; Tang, Huijuan; Guo, Yan; Guo, Jing; Huang, Bangxing; Fang, Fang; Cai, Jing; Wang, Zehua

    2015-01-01

    Adipose-derived mesenchymal stem cell (ADSC) is an important component of tumor microenvironment. However, whether ADSCs have a hand in ovarian cancer progression remains unclear. In this study, we investigated the impact of human ADSCs derived from the omentum of normal donors on human epithelial ovarian cancer (EOC) cells in vitro and in vivo. Direct and indirect co-culture models including ADSCs and human EOC cell lines were established and the effects of ADSCs on EOC cell proliferation were evaluated by EdU incorporation and flow cytometry. Transwell migration assays and detection of MMPs were performed to assess the invasion activity of EOC cells in vitro. Mouse models were established by intraperitoneal injection of EOC cells with or without concomitant ADSCs to investigate the role of ADSCs in tumor progression in vivo. We