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Sample records for notch target genes

  1. Identification of novel Notch target genes in T cell leukaemia

    PubMed Central

    Chadwick, Nicholas; Zeef, Leo; Portillo, Virginia; Fennessy, Carl; Warrander, Fiona; Hoyle, Sarah; Buckle, Anne-Marie

    2009-01-01

    Background Dysregulated Notch signalling is believed to play an important role in the development and maintenance of T cell leukaemia. At a cellular level, Notch signalling promotes proliferation and inhibits apoptosis of T cell acute lymphoblastic leukaemia (T-ALL) cells. In this study we aimed to identify novel transcriptional targets of Notch signalling in the T-ALL cell line, Jurkat. Results RNA was prepared from Jurkat cells retrovirally transduced with an empty vector (GFP-alone) or vectors containing constitutively active forms of Notch (N1ΔE or N3ΔE), and used for Affymetrix microarray analysis. A subset of genes found to be regulated by Notch was chosen for real-time PCR validation and in some cases, validation at the protein level, using several Notch-transduced T-ALL and non-T-ALL leukaemic cell lines. As expected, several known transcriptional target of Notch, such as HES1 and Deltex, were found to be overexpressed in Notch-transduced cells, however, many novel transcriptional targets of Notch signalling were identified using this approach. These included the T cell costimulatory molecule CD28, the anti-apoptotic protein GIMAP5, and inhibitor of DNA binding 1 (1D1). Conclusion The identification of such downstream Notch target genes provides insights into the mechanisms of Notch function in T cell leukaemia, and may help identify novel therapeutic targets in this disease. PMID:19508709

  2. Activated Notch1 Target Genes during Embryonic Cell Differentiation Depend on the Cellular Context and Include Lineage Determinants and Inhibitors

    PubMed Central

    Meier-Stiegen, Franziska; Schwanbeck, Ralf; Bernoth, Kristina; Martini, Simone; Hieronymus, Thomas; Ruau, David; Zenke, Martin; Just, Ursula

    2010-01-01

    Background Notch receptor signaling controls developmental cell fates in a cell-context dependent manner. Although Notch signaling directly regulates transcription via the RBP-J/CSL DNA binding protein, little is known about the target genes that are directly activated by Notch in the respective tissues. Methodology/Principal Findings To analyze how Notch signaling mediates its context dependent function(s), we utilized a Tamoxifen-inducible system to activate Notch1 in murine embryonic stem cells at different stages of mesodermal differentiation and performed global transcriptional analyses. We find that the majority of genes regulated by Notch1 are unique for the cell type and vary widely dependent on other signals. We further show that Notch1 signaling regulates expression of genes playing key roles in cell differentiation, cell cycle control and apoptosis in a context dependent manner. In addition to the known Notch1 targets of the Hes and Hey families of transcriptional repressors, Notch1 activates the expression of regulatory transcription factors such as Sox9, Pax6, Runx1, Myf5 and Id proteins that are critically involved in lineage decisions in the absence of protein synthesis. Conclusion/Significance We suggest that Notch signaling determines lineage decisions and expansion of stem cells by directly activating both key lineage specific transcription factors and their repressors (Id and Hes/Hey proteins) and propose a model by which Notch signaling regulates cell fate commitment and self renewal in dependence of the intrinsic and extrinsic cellular context. PMID:20628604

  3. Notch signaling genes

    PubMed Central

    Terragni, Jolyon; Zhang, Guoqiang; Sun, Zhiyi; Pradhan, Sriharsa; Song, Lingyun; Crawford, Gregory E; Lacey, Michelle; Ehrlich, Melanie

    2014-01-01

    Notch intercellular signaling is critical for diverse developmental pathways and for homeostasis in various types of stem cells and progenitor cells. Because Notch gene products need to be precisely regulated spatially and temporally, epigenetics is likely to help control expression of Notch signaling genes. Reduced representation bisulfite sequencing (RRBS) indicated significant hypomethylation in myoblasts, myotubes, and skeletal muscle vs. many nonmuscle samples at intragenic or intergenic regions of the following Notch receptor or ligand genes: NOTCH1, NOTCH2, JAG2, and DLL1. An enzymatic assay of sites in or near these genes revealed unusually high enrichment of 5-hydroxymethylcytosine (up to 81%) in skeletal muscle, heart, and cerebellum. Epigenetics studies and gene expression profiles suggest that hypomethylation and/or hydroxymethylation help control expression of these genes in heart, brain, myoblasts, myotubes, and within skeletal muscle myofibers. Such regulation could promote cell renewal, cell maintenance, homeostasis, and a poised state for repair of tissue damage. PMID:24670287

  4. Genes implicated in stem cell identity and temporal programme are directly targeted by Notch in neuroblast tumours

    PubMed Central

    Zacharioudaki, Evanthia; Housden, Benjamin E.; Garinis, George; Stojnic, Robert; Delidakis, Christos; Bray, Sarah J.

    2016-01-01

    Notch signalling is involved in a multitude of developmental decisions and its aberrant activation is linked to many diseases, including cancers. One example is the neural stem cell tumours that arise from constitutive Notch activity in Drosophila neuroblasts. To investigate how hyperactivation of Notch in larval neuroblasts leads to tumours, we combined results from profiling the upregulated mRNAs and mapping the regions bound by the core Notch pathway transcription factor Su(H). This identified 246 putative direct Notch targets. These genes were highly enriched for transcription factors and overlapped significantly with a previously identified regulatory programme dependent on the proneural transcription factor Asense. Included were genes associated with the neuroblast maintenance and self-renewal programme that we validated as Notch regulated in vivo. Another group were the so-called temporal transcription factors, which have been implicated in neuroblast maturation. Normally expressed in specific time windows, several temporal transcription factors were ectopically expressed in the stem cell tumours, suggesting that Notch had reprogrammed their normal temporal regulation. Indeed, the Notch-induced hyperplasia was reduced by mutations affecting two of the temporal factors, which, conversely, were sufficient to induce mild hyperplasia on their own. Altogether, the results suggest that Notch induces neuroblast tumours by directly promoting the expression of genes that contribute to stem cell identity and by reprogramming the expression of factors that could regulate maturity. PMID:26657768

  5. Local overexpression of Su(H)-MAPK variants affects Notch target gene expression and adult phenotypes in Drosophila.

    PubMed

    Auer, Jasmin S; Nagel, Anja C; Schulz, Adriana; Wahl, Vanessa; Preiss, Anette

    2015-12-01

    In Drosophila, Notch and EGFR signalling pathways are closely intertwined. Their relationship is mostly antagonistic, and may in part be based on the phosphorylation of the Notch signal transducer Suppressor of Hairless [Su(H)] by MAPK. Su(H) is a transcription factor that together with several cofactors regulates the expression of Notch target genes. Here we address the consequences of a local induction of three Su(H) variants on Notch target gene expression. To this end, wild-type Su(H), a phospho-deficient Su(H) (MAPK-) (ko) and a phospho-mimetic Su(H) (MAPK-ac) isoform were overexpressed in the central domain of the wing anlagen. The expression of the Notch target genes cut, wingless, E(spl)m8-HLH and vestigial, was monitored. For the latter two, reporter genes were used (E(spl)m8-lacZ, vg (BE) -lacZ). In general, Su(H) (MAPK-) (ko) induced a stronger response than wild-type Su(H), whereas the response to Su(H) (MAPK-ac) was very weak. Notch target genes cut, wingless and vg (BE) -lacZ were ectopically activated, whereas E(spl)m8-lacZ was repressed by overexpression of Su(H) proteins. In addition, in epistasis experiments an activated form of the EGF-receptor (DER (act) ) or the MAPK (rl (SEM) ) and individual Su(H) variants were co-overexpressed locally, to compare the resultant phenotypes in adult flies (thorax, wings and eyes) as well as to assay the response of the Notch target gene cut in cell clones.

  6. The Anti-Adipogenic Potential of COUP-TFII Is Mediated by Downregulation of the Notch Target Gene Hey1

    PubMed Central

    Scroyen, Ilse; Bauters, Dries; Vranckx, Christine; Lijnen, H. Roger

    2015-01-01

    Background Chicken ovalbumin upstream promoter transcription factor II (COUP-TFII) belongs to the steroid/thyroid hormone receptor superfamily and may contribute to the pathogenesis of obesity. It has not conclusively been established, however, whether its role is pro- or anti-adipogenic. Methods and Results Gene silencing of Coup-tfII in 3T3-F442A preadipocytes resulted in enhanced differentiation into mature adipocytes. This was associated with upregulation of the Notch signaling target gene Hey1. A functional role of Hey1 was confirmed by gene silencing in 3T3-F442A preadipocytes, resulting in impaired differentiation. In vivo, de novo fat pad formation in NUDE mice was significantly stimulated following injection of preadipocytes with Coup-tfII gene silencing, but impaired with Hey1 gene silencing. Moreover, expression of Coup-tfII was lower and that of Hey1 higher in isolated adipocytes of obese as compared to lean adipose tissue. Conclusions These in vitro and in vivo data support an anti-adipogenic role of COUP-TFII via downregulating the Notch signaling target gene Hey1. PMID:26719988

  7. Prostate tumor OVerexpressed-1 (PTOV1) down-regulates HES1 and HEY1 notch targets genes and promotes prostate cancer progression

    PubMed Central

    2014-01-01

    Background PTOV1 is an adaptor protein with functions in diverse processes, including gene transcription and protein translation, whose overexpression is associated with a higher proliferation index and tumor grade in prostate cancer (PC) and other neoplasms. Here we report its interaction with the Notch pathway and its involvement in PC progression. Methods Stable PTOV1 knockdown or overexpression were performed by lentiviral transduction. Protein interactions were analyzed by co-immunoprecipitation, pull-down and/or immunofluorescence. Endogenous gene expression was analyzed by real time RT-PCR and/or Western blotting. Exogenous promoter activities were studied by luciferase assays. Gene promoter interactions were analyzed by chromatin immunoprecipitation assays (ChIP). In vivo studies were performed in the Drosophila melanogaster wing, the SCID-Beige mouse model, and human prostate cancer tissues and metastasis. The Excel package was used for statistical analysis. Results Knockdown of PTOV1 in prostate epithelial cells and HaCaT skin keratinocytes caused the upregulation, and overexpression of PTOV1 the downregulation, of the Notch target genes HEY1 and HES1, suggesting that PTOV1 counteracts Notch signaling. Under conditions of inactive Notch signaling, endogenous PTOV1 associated with the HEY1 and HES1 promoters, together with components of the Notch repressor complex. Conversely, expression of active Notch1 provoked the dismissal of PTOV1 from these promoters. The antagonist role of PTOV1 on Notch activity was corroborated in the Drosophila melanogaster wing, where human PTOV1 exacerbated Notch deletion mutant phenotypes and suppressed the effects of constitutively active Notch. PTOV1 was required for optimal in vitro invasiveness and anchorage-independent growth of PC-3 cells, activities counteracted by Notch, and for their efficient growth and metastatic spread in vivo. In prostate tumors, the overexpression of PTOV1 was associated with decreased expression

  8. Pervasive regulation of Drosophila Notch target genes by GY-box-, Brd-box-, and K-box-class microRNAs.

    PubMed

    Lai, Eric C; Tam, Bergin; Rubin, Gerald M

    2005-05-01

    Although hundreds of distinct animal microRNAs (miRNAs) are known, the specific biological functions of only a handful are understood at present. Here, we demonstrate that three different families of Drosophila miRNAs directly regulate two large families of Notch target genes, including basic helix-loop-helix (bHLH) repressor and Bearded family genes. These miRNAs regulate Notch target gene activity via GY-box (GUCUUCC), Brd-box (AGCUUUA), and K-box (cUGUGAUa) motifs. These are conserved sites in target 3'-untranslated regions (3'-UTRs) that are complementary to the 5'-ends of miRNAs, or "seed" regions. Collectively, these motifs represent >40 miRNA-binding sites in Notch target genes, and we show all three classes of motif to be necessary and sufficient for miRNA-mediated regulation in vivo. Importantly, many of the validated miRNA-binding sites have limited pairing to miRNAs outside of the "box:seed" region. Consistent with this, we find that seed-related miRNAs that are otherwise quite divergent can regulate the same target sequences. Finally, we demonstrate that ectopic expression of several Notch-regulating miRNAs induces mutant phenotypes that are characteristic of Notch pathway loss of function, including loss of wing margin, thickened wing veins, increased bristle density, and tufted bristles. Collectively, these data establish insights into miRNA target recognition and demonstrate that the Notch signaling pathway is a major target of miRNA-mediated regulation in Drosophila.

  9. NOTCH2 and FLT3 gene mis-splicings are common events in patients with acute myeloid leukemia (AML): new potential targets in AML

    PubMed Central

    Bar-Natan, Michal; Haibe-Kains, Benjamin; Pilarski, Patrick M.; Bach, Christian; Pevzner, Samuel; Calimeri, Teresa; Avet-Loiseau, Herve; Lode, Laurence; Verselis, Sigitas; Fox, Edward A.; Galinsky, Ilene; Mathews, Steven; Dagogo-Jack, Ibiayi; Wadleigh, Martha; Steensma, David P.; Motyckova, Gabriela; Deangelo, Daniel J.; Quackenbush, John; Tenen, Daniel G.; Stone, Richard M.; Griffin, James D.

    2014-01-01

    Our previous studies revealed an increase in alternative splicing of multiple RNAs in cells from patients with acute myeloid leukemia (AML) compared with CD34+ bone marrow cells from normal donors. Aberrantly spliced genes included a number of oncogenes, tumor suppressor genes, and genes involved in regulation of apoptosis, cell cycle, and cell differentiation. Among the most commonly mis-spliced genes (>70% of AML patients) were 2, NOTCH2 and FLT3, that encode myeloid cell surface proteins. The splice variants of NOTCH2 and FLT3 resulted from complete or partial exon skipping and utilization of cryptic splice sites. Longitudinal analyses suggested that NOTCH2 and FLT3 aberrant splicing correlated with disease status. Correlation analyses between splice variants of these genes and clinical features of patients showed an association between NOTCH2-Va splice variant and overall survival of patients. Our results suggest that NOTCH2 and FLT3 mis-splicing is a common characteristic of AML and has the potential to generate transcripts encoding proteins with altered function. Thus, splice variants of these genes might provide disease markers and targets for novel therapeutics. PMID:24574459

  10. The Wnt3a/β-catenin target gene Mesogenin1 controls the segmentation clock by activating a Notch signaling program

    PubMed Central

    Chalamalasetty, Ravindra B.; Dunty, William C.; Biris, Kristin K.; Ajima, Rieko; Iacovino, Michelina; Beisaw, Arica; Feigenbaum, Lionel; Chapman, Deborah L.; Yoon, Jeong Kyo; Kyba, Michael; Yamaguchi, Terry P.

    2013-01-01

    Summary Segmentation is an organizing principle of body plans. The segmentation clock, a molecular oscillator best illustrated by the cyclic expression of Notch signaling genes, controls the periodic cleavage of somites from unsegmented presomitic mesoderm (PSM) during vertebrate segmentation. Wnt3a controls the spatiotemporal expression of cyclic Notch genes, however the underlying mechanisms remain obscure. Transcriptional profiling of Wnt3a−/− embryos led to the identification of the bHLH transcription factor, Mesogenin1 (Msgn1), as a direct target gene of Wnt3a. To identify Msgn1 targets, we performed genome-wide studies of Msgn1 activity in embryonic stem cells. Here we show that Msgn1 is a major transcriptional activator of a Notch signaling program, synergizing with Notch to trigger clock gene expression. Msgn1 also indirectly regulates cyclic genes in the Fgf and Wnt pathways. Thus, Msgn1 is a central component of a transcriptional cascade that translates a spatial Wnt3a gradient into a temporal pattern of clock gene expression. PMID:21750544

  11. Notch1 Gene Mutations Target KRAS G12D-expressing CD8+ Cells and Contribute to Their Leukemogenic Transformation*

    PubMed Central

    Kong, Guangyao; Du, Juan; Liu, Yangang; Meline, Benjamin; Chang, Yuan-I; Ranheim, Erik A.; Wang, Jinyong; Zhang, Jing

    2013-01-01

    Acute T-cell lymphoblastic leukemia/lymphoma (T-ALL) is an aggressive hematopoietic malignancy affecting both children and adults. Previous studies of T-ALL mouse models induced by different genetic mutations have provided highly diverse results on the issues of T-cell leukemia/lymphoma-initiating cells (T-LICs) and potential mechanisms contributing to T-LIC transformation. Here, we show that oncogenic Kras (Kras G12D) expressed from its endogenous locus is a potent inducer of T-ALL even in a less sensitized BALB/c background. Notch1 mutations, including exon 34 mutations and recently characterized type 1 and 2 deletions, are detected in 100% of Kras G12D-induced T-ALL tumors. Although these mutations are not detected at the pre-leukemia stage, incremental up-regulation of NOTCH1 surface expression is observed at the pre-leukemia and leukemia stages. As secondary genetic hits in the Kras G12D model, Notch1 mutations target CD8+ T-cells but not hematopoietic stem cells to further promote T-ALL progression. Pre-leukemia T-cells without detectable Notch1 mutations do not induce T-ALL in secondary recipient mice compared with T-ALL tumor cells with Notch1 mutations. We found huge variations in T-LIC frequency and immunophenotypes of cells enriched for T-LICs. Unlike Pten deficiency-induced T-ALL, oncogenic Kras-initiated T-ALL is not associated with up-regulation of the Wnt/β-catenin pathway. Our results suggest that up-regulation of NOTCH1 signaling, through either overexpression of surface NOTCH1 or acquired gain-of-function mutations, is involved in both T-ALL initiation and progression. Notch1 mutations and Kras G12D contribute cooperatively to leukemogenic transformation of normal T-cells. PMID:23673656

  12. Targeting Notch to overcome radiation resistance

    PubMed Central

    Yahyanejad, Sanaz; Theys, Jan; Vooijs, Marc

    2016-01-01

    Radiotherapy represents an important therapeutic strategy in the treatment of cancer cells. However, it often fails to eliminate all tumor cells because of the intrinsic or acquired treatment resistance, which is the most common cause of tumor recurrence. Emerging evidences suggest that the Notch signaling pathway is an important pathway mediating radiation resistance in tumor cells. Successful targeting of Notch signaling requires a thorough understanding of Notch regulation and the context-dependent interactions between Notch and other therapeutically relevant pathways. Understanding these interactions will increase our ability to design rational combination regimens that are more likely to be safe and effective. Here we summarize the role of Notch in mediating resistance to radiotherapy, the different strategies to block Notch in cancer cells and how treatment scheduling can improve tumor response. Finally, we discuss a need for reliable Notch related biomarkers in specific tumors to measure pathway activity and to allow identification of a subset of patients who are likely to benefit from Notch targeted therapies. PMID:26713603

  13. A phospho-dependent mechanism involving NCoR and KMT2D controls a permissive chromatin state at Notch target genes

    PubMed Central

    Oswald, Franz; Rodriguez, Patrick; Giaimo, Benedetto Daniele; Antonello, Zeus A.; Mira, Laura; Mittler, Gerhard; Thiel, Verena N.; Collins, Kelly J.; Tabaja, Nassif; Cizelsky, Wiebke; Rothe, Melanie; Kühl, Susanne J.; Kühl, Michael; Ferrante, Francesca; Hein, Kerstin; Kovall, Rhett A.; Dominguez, Maria; Borggrefe, Tilman

    2016-01-01

    The transcriptional shift from repression to activation of target genes is crucial for the fidelity of Notch responses through incompletely understood mechanisms that likely involve chromatin-based control. To activate silenced genes, repressive chromatin marks are removed and active marks must be acquired. Histone H3 lysine-4 (H3K4) demethylases are key chromatin modifiers that establish the repressive chromatin state at Notch target genes. However, the counteracting histone methyltransferase required for the active chromatin state remained elusive. Here, we show that the RBP-J interacting factor SHARP is not only able to interact with the NCoR corepressor complex, but also with the H3K4 methyltransferase KMT2D coactivator complex. KMT2D and NCoR compete for the C-terminal SPOC-domain of SHARP. We reveal that the SPOC-domain exclusively binds to phosphorylated NCoR. The balance between NCoR and KMT2D binding is shifted upon mutating the phosphorylation sites of NCoR or upon inhibition of the NCoR kinase CK2β. Furthermore, we show that the homologs of SHARP and KMT2D in Drosophila also physically interact and control Notch-mediated functions in vivo. Together, our findings reveal how signaling can fine-tune a committed chromatin state by phosphorylation of a pivotal chromatin-modifier. PMID:26912830

  14. Notch Signaling: A Potential Therapeutic Target for Hematologic Malignancies.

    PubMed

    Gao, Lingbao; Yuan, Keyu; Ding, Wei; Lin, Mei

    2016-01-01

    Notch signaling is a well-conserved cell-fate determining factor in embryo development, and the dyregulation of this signaling is frequently observed in many types of cancers, including hematological malignancies. In this review, we briefly describe the Notch signaling pathway, and we primarily focus on the relationship between Notch and hematological malignancies. We also discuss the clinical development of promising agents including γ-secretase inhibitors (GSIs) and monoclonal antibodies (mAbs). Complete response has been observed among patients with T-cell acute lymphoblastic leukemia (T-ALL) when treated with GSIs. Furthermore, a recent study has suggested that targeting Zmiz1, a direct, selective cofactor of Notch1, rather than targeting Notch directly, maybe helpful to reduce the current target-related toxicities. Taken together, we summarize the role of Notch signaling in hematological malignancies and discuss the treatment strategies for these diseases through targeting Notch signaling. PMID:27650987

  15. Targeting the Notch signaling pathway in cancer therapeutics

    PubMed Central

    Guo, Huajiao; Lu, Yi; Wang, Jianhua; Liu, Xia; Keller, Evan T; Liu, Qian; Zhou, Qinghua; Zhang, Jian

    2014-01-01

    Despite advances in surgery, imaging, chemotherapy, and radiotherapy, the poor overall cancer-related death rate remains unacceptable. Novel therapeutic strategies are desperately needed. Nowadays, targeted therapy has become the most promising therapy and a welcome asset to the cancer therapeutic arena. There is a large body of evidence demonstrating that the Notch signaling pathway is critically involved in the pathobiology of a variety of malignancies. In this review, we provide an overview of emerging data, highlight the mechanism of the Notch signaling pathway in the development of a wide range of cancers, and summarize recent progress in therapeutic targeting of the Notch signaling pathway. PMID:26767041

  16. Notch stimulates growth by direct regulation of genes involved in the control of glycolysis and the tricarboxylic acid cycle

    PubMed Central

    Slaninova, Vera; Krafcikova, Michaela; Perez-Gomez, Raquel; Steffal, Pavel; Trantirek, Lukas; Bray, Sarah J.

    2016-01-01

    Glycolytic shift is a characteristic feature of rapidly proliferating cells, such as cells during development and during immune response or cancer cells, as well as of stem cells. It results in increased glycolysis uncoupled from mitochondrial respiration, also known as the Warburg effect. Notch signalling is active in contexts where cells undergo glycolytic shift. We decided to test whether metabolic genes are direct transcriptional targets of Notch signalling and whether upregulation of metabolic genes can help Notch to induce tissue growth under physiological conditions and in conditions of Notch-induced hyperplasia. We show that genes mediating cellular metabolic changes towards the Warburg effect are direct transcriptional targets of Notch signalling. They include genes encoding proteins involved in glucose uptake, glycolysis, lactate to pyruvate conversion and repression of the tricarboxylic acid cycle. The direct transcriptional upregulation of metabolic genes is PI3K/Akt independent and occurs not only in cells with overactivated Notch but also in cells with endogenous levels of Notch signalling and in vivo. Even a short pulse of Notch activity is able to elicit long-lasting metabolic changes resembling the Warburg effect. Loss of Notch signalling in Drosophila wing discs as well as in human microvascular cells leads to downregulation of glycolytic genes. Notch-driven tissue overgrowth can be rescued by downregulation of genes for glucose metabolism. Notch activity is able to support growth of wing during nutrient-deprivation conditions, independent of the growth of the rest of the body. Notch is active in situations that involve metabolic reprogramming, and the direct regulation of metabolic genes may be a common mechanism that helps Notch to exert its effects in target tissues. PMID:26887408

  17. CDKN1C/P57 is regulated by the Notch target gene Hes1 and induces senescence in human hepatocellular carcinoma.

    PubMed

    Giovannini, Catia; Gramantieri, Laura; Minguzzi, Manuela; Fornari, Francesca; Chieco, Pasquale; Grazi, Gian Luca; Bolondi, Luigi

    2012-08-01

    CDKN1C/P57 is a cyclin-dependent kinase inhibitor implicated in different human cancers, including hepatocellular carcinoma (HCC); however, little is known regarding the role of CDKN1C/P57 and its regulation in HCC. In this study, we show that the down-regulation of Notch1 and Notch3 in two HCC cell lines resulted in Hes1 down-regulation, CDKN1C/P57 up-regulation, and reduced cell growth. In line with these data, we report that CDKN1C/P57 is a target of transcriptional repression by the Notch effector, Hes1. We found that the up-regulation of CDKN1C/P57 by cDNA transfection decreased tumor growth, as determined by growth curve, flow cytometry analysis, and cyclin D1 down-regulation, without affecting the apoptosis machinery. Indeed, the expression of Bax, Noxa, PUMA, BNIP(3), and cleaved caspase-3 was not affected by CDKN1C/P57 induction. Morphologically CDKN1C/p57-induced HCC cells became flat and lengthened in shape, accumulated the senescence-associated β-galactosidase marker, and increased P16 protein expression. Evaluation of senescence in cells depleted both for Hes1 and CDKN1C/P57 revealed that the senescent state really depends on the accumulation of CDKN1C/p57. Finally, we validated our in vitro results in primary HCCs, showing that Hes1 protein expression inversely correlates with CDKN1C/P57 mRNA levels. In addition, reduced Hes1 protein expression is accompanied by a shorter time to recurrence after curative resection, suggesting that Hes1 may represent a biomarker for prediction of patients with poor prognosis.

  18. Novel genes upregulated when NOTCH signalling is disrupted during hypothalamic development

    PubMed Central

    2013-01-01

    Background The generation of diverse neuronal types and subtypes from multipotent progenitors during development is crucial for assembling functional neural circuits in the adult central nervous system. It is well known that the Notch signalling pathway through the inhibition of proneural genes is a key regulator of neurogenesis in the vertebrate central nervous system. However, the role of Notch during hypothalamus formation along with its downstream effectors remains poorly defined. Results Here, we have transiently blocked Notch activity in chick embryos and used global gene expression analysis to provide evidence that Notch signalling modulates the generation of neurons in the early developing hypothalamus by lateral inhibition. Most importantly, we have taken advantage of this model to identify novel targets of Notch signalling, such as Tagln3 and Chga, which were expressed in hypothalamic neuronal nuclei. Conclusions These data give essential advances into the early generation of neurons in the hypothalamus. We demonstrate that inhibition of Notch signalling during early development of the hypothalamus enhances expression of several new markers. These genes must be considered as important new targets of the Notch/proneural network. PMID:24360028

  19. Gene Deletion Screen for Cardiomyopathy in Adult Drosophila Identifies a New Notch Ligand

    PubMed Central

    Kim, Il-Man; Wolf, Matthew J.; Rockman, Howard A.

    2010-01-01

    Rationale Drosophila has been recognized as a model to study human cardiac diseases. Objective Despite these findings, and the wealth of tools that are available to the fly community, forward genetic screens for adult heart phenotypes have been rarely performed due to the difficulty in accurately measuring cardiac function in adult Drosophila. Methods and Results Using optical coherence tomography to obtain real-time analysis of cardiac function in awake Drosophila, we performed a genomic deficiency screen in adult flies. Based on multiple complementary approaches, we identified CG31665 as a novel gene causing dilated cardiomyopathy. CG31665, which we name weary (wry), has structural similarities to members of the Notch family. Using cell aggregation assays and γ-secretase inhibitors we show that Wry is a novel Notch ligand that can mediate cellular adhesion with Notch expressing cells and transactivates Notch to promote signaling and nuclear transcription. Importantly, Wry lacks a DSL (Delta-Serrate-Lag) domain that is common feature to the other Drosophila Notch ligands. We further show that Notch signaling is critically important for the maintenance of normal heart function of the adult fly. Conclusions In conclusion, we identify a previously unknown Notch ligand in Drosophila that when deleted causes cardiomyopathy. Our study suggests that Notch signaling components may be a therapeutic target for dilated cardiomyopathy. PMID:20203305

  20. An accessible pharmacodynamic transcriptional biomarker for notch target engagement.

    PubMed

    Tanis, K Q; Podtelezhnikov, A A; Blackman, S C; Hing, J; Railkar, R A; Lunceford, J; Klappenbach, J A; Wei, B; Harman, A; Camargo, L M; Shah, S; Finney, E M; Hardwick, J S; Loboda, A; Watters, J; Bergstrom, D A; Demuth, T; Herman, G A; Strack, P R; Iannone, R

    2016-04-01

    γ-Secretase mediates amyloid production in Alzheimer's disease (AD) and oncogenic activity of Notch. γ-Secretase inhibitors (GSIs) are thus of interest for AD and oncology. A peripheral biomarker of Notch activity would aid determination of the therapeutic window and dosing regimen for GSIs, given toxicities associated with chronic Notch inhibition. This study examined the effects of GSI MK-0752 on blood and hair follicle transcriptomes in healthy volunteers. The effects of a structurally diverse GSI on rhesus blood and hair follicles were also compared. Significant dose-related effects of MK-0752 on transcription were observed in hair follicles, but not blood. The GSI biomarker identified in follicles exhibited 100% accuracy in a clinical test cohort, and was regulated in rhesus by a structurally diverse GSI. This study identified a translatable, accessible pharmacodynamic biomarker of GSI target engagement and provides proof of concept of hair follicle RNA as a translatable biomarker source.

  1. Targeting Notch1 inhibits invasion and angiogenesis of human breast cancer cells via inhibition Nuclear Factor-κB signaling.

    PubMed

    Liu, Yuan; Su, Chuanfu; Shan, Yuqing; Yang, Shouxiang; Ma, Guifeng

    2016-01-01

    Notch-1, a type-1 transmembrane protein, plays critical roles in the pathogenesis and progression of human malignancies, including breast cancer; however, the precise mechanism by which Notch-1 causes tumor cell invasion and angiogenesis remain unclear. Nuclear factor-κB (NF-κB), interleukin-8 (IL-8), vascular endothelial growth factor (VEGF), and matrix metalloproteinases (MMP) are critically involved in the processes of tumor cell invasion and metastasis, we investigated whether targeting Notch-1 could be mechanistically associated with the down-regulation of NF-κB, IL-8, VEGF, and MMP-9, resulting in the inhibition of invasion and angiogenesis of breast cancer cells. Our data showed that down-regulation of Notch-1 leads to the inactivation of NF-κB activity and inhibits the expression of its target genes, such as IL-8, VEGF and MMP-9. We also found that down-regulation of Notch-1 decreased cell invasion, and vice versa Consistent with these results, we also found that the down-regulation of Notch-1 not only decreased MMP-9 mRNA and its protein expression but also inhibited MMP-9 active form. Moreover, conditioned medium from Notch-1 siRNA-transfected breast cancer cells showed reduced levels of IL-8 and VEGF and, in turn, inhibited the tube formation of HUVECs, suggesting that down-regulation of Notch-1 leads to the inhibition of angiogenesis. Furthermore, conditioned medium from Notch-1 cDNA-transfected breast cancer cells showed increased levels of IL-8 and VEGF and, in turn, promoted the tube formation of HUVECs, suggesting that Notch-1 overexpression leads to the promotion of angiogenesis.We therefore concluded that down-regulation of Notch-1 leads to the inactivation NF-κB and its target genes (IL-8, MMP-9 and VEGF), resulting in the inhibition of invasion and angiogenesis.

  2. Targeting Notch1 inhibits invasion and angiogenesis of human breast cancer cells via inhibition Nuclear Factor-κB signaling

    PubMed Central

    Liu, Yuan; Su, Chuanfu; Shan, Yuqing; Yang, Shouxiang; Ma, Guifeng

    2016-01-01

    Notch-1, a type-1 transmembrane protein, plays critical roles in the pathogenesis and progression of human malignancies, including breast cancer; however, the precise mechanism by which Notch-1 causes tumor cell invasion and angiogenesis remain unclear. Nuclear factor-κB (NF-κB), interleukin-8 (IL-8), vascular endothelial growth factor (VEGF), and matrix metalloproteinases (MMP) are critically involved in the processes of tumor cell invasion and metastasis, we investigated whether targeting Notch-1 could be mechanistically associated with the down-regulation of NF-κB, IL-8, VEGF, and MMP-9, resulting in the inhibition of invasion and angiogenesis of breast cancer cells. Our data showed that down-regulation of Notch-1 leads to the inactivation of NF-κB activity and inhibits the expression of its target genes, such as IL-8, VEGF and MMP-9. We also found that down-regulation of Notch-1 decreased cell invasion, and vice versa Consistent with these results, we also found that the down-regulation of Notch-1 not only decreased MMP-9 mRNA and its protein expression but also inhibited MMP-9 active form. Moreover, conditioned medium from Notch-1 siRNA-transfected breast cancer cells showed reduced levels of IL-8 and VEGF and, in turn, inhibited the tube formation of HUVECs, suggesting that down-regulation of Notch-1 leads to the inhibition of angiogenesis. Furthermore, conditioned medium from Notch-1 cDNA-transfected breast cancer cells showed increased levels of IL-8 and VEGF and, in turn, promoted the tube formation of HUVECs, suggesting that Notch-1 overexpression leads to the promotion of angiogenesis.We therefore concluded that down-regulation of Notch-1 leads to the inactivation NF-κB and its target genes (IL-8, MMP-9 and VEGF), resulting in the inhibition of invasion and angiogenesis. PMID:27398151

  3. Differential effects of targeting Notch receptors in a mouse model of liver cancer

    PubMed Central

    Huntzicker, Erik G.; Hötzel, Kathy; Choy, Lisa; Che, Li; Ross, Jed; Pau, Gregoire; Sharma, Neeraj; Siebel, Christian W.; Chen, Xin; French, Dorothy M.

    2015-01-01

    Primary liver cancer encompasses both hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC). The Notch signaling pathway, known to be important for the proper development of liver architecture, is also a potential driver of primary liver cancer. However, with four known Notch receptors and several Notch ligands, it is not clear which Notch pathway members play the predominant role in liver cancer. To address this question we utilized antibodies to specifically target Notch1, Notch2, Notch3 or Jag1 in a mouse model of primary liver cancer driven by AKT and NRas. We show that inhibition of Notch2 reduces tumor burden by eliminating highly malignant hepatocellular carcinoma- and cholangiocarcinoma-like tumors. Inhibition of the Notch ligand Jag 1 had a similar effect, consistent with Jag1 acting in cooperation with Notch2. This effect was specific to Notch2, as Notch3 inhibition did not decrease tumor burden. Unexpectedly, Notch1 inhibition altered the relative proportion of tumor types, reducing HCC-like tumors but dramatically increasing CC-like tumors. Finally, we show that Notch2 and Jag1 are expressed in, and Notch2 signaling is activated in, a subset of human HCC samples. Conclusions: These findings underscore the distinct roles of different Notch receptors in the liver and suggest that inhibition of Notch2 signaling represents a novel therapeutic option in the treatment of liver cancer. PMID:25311838

  4. Notch1 is associated with the multidrug resistance of hypoxic osteosarcoma by regulating MRP1 gene expression.

    PubMed

    Li, C; Guo, D; Tang, B; Zhang, Y; Zhang, K; Nie, L

    2016-01-01

    Hypoxia and Notch signaling pathway are closely related and both participate in cell proliferation and drug resistance of tumors. However, the molecular mechanisms of hypoxia and Notch signaling pathway in cell proliferation and drug resistance of osteosarcoma (OS) remain unclear. In this study, to further evaluate the role of hypoxia and Notch1 on drug resistance of OS, we investigated the influence of inhibiting Notch1 pathway by Notch1 small interference RNA (siRNA) on human MG-63 OS cells in hypoxia. Our data showed that hypoxia promoted OS cell proliferation, induced the G0/G1-S-G2/M phase transition, and increased multidrug resistance of human OS cells. Western blot analysis suggested that hypoxia increased the expression of HIF-1α, Notch1, and multidrug resistance protein-1 (MRP1) in human OS cells. Notch1 siRNA inhibits proliferation and increases apoptosis of hypoxic OS cells. Finally, these hypoxic OS cells can be sensitized to multidrug treatment through inhibition of the Notch protein expression by siRNA. Repression of the Notch protein expression resulted in down-regulation of MRP1 protein. These data support the conclusion that Notch signaling is up-regulated in human OS cells under hypoxia and Notch1 may represent a viable target to overcome chemoresistant OS cells in a hypoxic niche by regulating MRP1 gene expression. PMID:27468877

  5. Expression of Notch pathway genes in the embryonic mouse metanephros suggests a role in proximal tubule development.

    PubMed

    Leimeister, Cornelia; Schumacher, Nina; Gessler, Manfred

    2003-10-01

    The interaction of neighboring cells via Notch signalling leads to cell fate determination, differentiation and patterning of highly organized tissues. Mice with targeted disruption of genes from the Notch signal transduction pathway display defects in the developing somites, neurogenic structures, blood vessels, heart and other organs. Recent studies have added requirements for Notch signalling during kidney, pancreas and thymus morphogenesis. Here, we describe the expression of all four receptors (Notch1-4), the five transmembrane ligands (Dll1, 3, 4, Jag1 and Jag2), intracellular effectors (the Hey genes) and extracellular modulators (Lfng, Mfng, Rfng) in the developing mouse metanephros. Our results point to a Lfng-dependent role for Notch signalling in the development of nephron segments, especially the proximal tubules.

  6. From Fly Wings to Targeted Cancer Therapies: A Centennial for Notch Signaling

    PubMed Central

    Ntziachristos, Panagiotis; Lim, Jing Shan; Sage, Julien; Aifantis, Iannis

    2014-01-01

    Since Notch phenotypes in Drosophila melanogaster were identified 100 years, Notch signaling has been extensively characterized as a regulator of cell fate decisions in a variety of organisms and tissues. However, in the past 20 years, accumulating evidence has linked alterations in the Notch pathway to tumorigenesis. In this Perspective, we discuss the pro-tumorigenic and tumor suppressive functions of Notch signaling and dissect the molecular mechanisms that underlie these functions in hematopoietic cancers and solid tumors. Finally, we link these mechanisms and observations to possible therapeutic strategies targeting the Notch pathway in human cancers. PMID:24651013

  7. Preclinical profile of a potent gamma-secretase inhibitor targeting notch signaling with in vivo efficacy and pharmacodynamic properties.

    PubMed

    Luistro, Leopoldo; He, Wei; Smith, Melissa; Packman, Kathryn; Vilenchik, Maria; Carvajal, Daisy; Roberts, John; Cai, James; Berkofsky-Fessler, Windy; Hilton, Holly; Linn, Michael; Flohr, Alexander; Jakob-Røtne, Roland; Jacobsen, Helmut; Glenn, Kelli; Heimbrook, David; Boylan, John F

    2009-10-01

    Notch signaling is an area of great interest in oncology. RO4929097 is a potent and selective inhibitor of gamma-secretase, producing inhibitory activity of Notch signaling in tumor cells. The RO4929097 IC50 in cell-free and cellular assays is in the low nanomolar range with >100-fold selectivity with respect to 75 other proteins of various types (receptors, ion channels, and enzymes). RO4929097 inhibits Notch processing in tumor cells as measured by the reduction of intracellular Notch expression by Western blot. This leads to reduced expression of the Notch transcriptional target gene Hes1. RO4929097 does not block tumor cell proliferation or induce apoptosis but instead produces a less transformed, flattened, slower-growing phenotype. RO4929097 is active following oral dosing. Antitumor activity was shown in 7 of 8 xenografts tested on an intermittent or daily schedule in the absence of body weight loss or Notch-related toxicities. Importantly, efficacy is maintained after dosing is terminated. Angiogenesis reverse transcription-PCR array data show reduced expression of several key angiogenic genes. In addition, comparative microarray analysis suggests tumor cell differentiation as an additional mode of action. These preclinical results support evaluation of RO4929097 in clinical studies using an intermittent dosing schedule. A multicenter phase I dose escalation study in oncology is under way. PMID:19773430

  8. Preclinical profile of a potent gamma-secretase inhibitor targeting notch signaling with in vivo efficacy and pharmacodynamic properties.

    PubMed

    Luistro, Leopoldo; He, Wei; Smith, Melissa; Packman, Kathryn; Vilenchik, Maria; Carvajal, Daisy; Roberts, John; Cai, James; Berkofsky-Fessler, Windy; Hilton, Holly; Linn, Michael; Flohr, Alexander; Jakob-Røtne, Roland; Jacobsen, Helmut; Glenn, Kelli; Heimbrook, David; Boylan, John F

    2009-10-01

    Notch signaling is an area of great interest in oncology. RO4929097 is a potent and selective inhibitor of gamma-secretase, producing inhibitory activity of Notch signaling in tumor cells. The RO4929097 IC50 in cell-free and cellular assays is in the low nanomolar range with >100-fold selectivity with respect to 75 other proteins of various types (receptors, ion channels, and enzymes). RO4929097 inhibits Notch processing in tumor cells as measured by the reduction of intracellular Notch expression by Western blot. This leads to reduced expression of the Notch transcriptional target gene Hes1. RO4929097 does not block tumor cell proliferation or induce apoptosis but instead produces a less transformed, flattened, slower-growing phenotype. RO4929097 is active following oral dosing. Antitumor activity was shown in 7 of 8 xenografts tested on an intermittent or daily schedule in the absence of body weight loss or Notch-related toxicities. Importantly, efficacy is maintained after dosing is terminated. Angiogenesis reverse transcription-PCR array data show reduced expression of several key angiogenic genes. In addition, comparative microarray analysis suggests tumor cell differentiation as an additional mode of action. These preclinical results support evaluation of RO4929097 in clinical studies using an intermittent dosing schedule. A multicenter phase I dose escalation study in oncology is under way.

  9. Targeting Notch degradation system provides promise for breast cancer therapeutics.

    PubMed

    Liu, Jing; Shen, Jia-Xin; Wen, Xiao-Fen; Guo, Yu-Xian; Zhang, Guo-Jun

    2016-08-01

    Notch receptor signaling pathways play an important role, not only in normal breast development but also in breast cancer development and progression. As a group of ligand-induced proteins, different subtypes of mammalian Notch (Notch1-4) are sensitive to subtle changes in protein levels. Thus, a clear understanding of mechanisms of Notch protein turnover is essential for understanding normal and pathological mechanisms of Notch functions. It has been suggested that there is a close relationship between the carcinogenesis and the dysregulation of Notch degradation. However, this relationship remains mostly undefined in the context of breast cancer, as protein degradation is mediated by numerous signaling pathways as well as certain molecule modulators (activators/inhibitors). In this review, we summarize the published data regarding the regulation of Notch family member degradation in breast cancer, while emphasizing areas that are likely to provide new therapeutic modalities for mechanism-based anti-cancer drugs.

  10. Nuclear IKK activity leads to dysregulated notch-dependent gene expression in colorectal cancer.

    PubMed

    Fernández-Majada, V; Aguilera, C; Villanueva, A; Vilardell, F; Robert-Moreno, A; Aytés, A; Real, F X; Capella, G; Mayo, M W; Espinosa, L; Bigas, A

    2007-01-01

    Nuclear functions for IkappaB kinase (IKK), including phosphorylation of histone H3 and nuclear corepressors, have been recently described. Here, we show that IKK is activated in colorectal tumors concomitant with the presence of phosphorylated SMRT (silencing mediator of retinoic acid and thyroid hormone receptor) corepressor that is aberrantly localized in the cytoplasm. In these tumors, IKKalpha associates to the chromatin of specific Notch targets, leading to the release of SMRT. Abrogation of IKK activity by BAY11-7082 or by expressing dominant negative IKKalpha restores the association of SMRT with Notch target genes, resulting in specific gene repression. Finally, BAY11-7082 significantly reduces tumor size in colorectal cancer xenografts (CRC-Xs) implanted in nude mice.

  11. WNT antagonist, DKK2, is a Notch signaling target in intestinal stem cells: augmentation of a negative regulation system for canonical WNT signaling pathway by the Notch-DKK2 signaling loop in primates.

    PubMed

    Katoh, Masuko; Katoh, Masaru

    2007-01-01

    Notch and WNT signaling pathways are key components of the stem cell signaling network. Canonical WNT signaling to intestinal progenitor cells leads to transcriptional activation of the JAG1 gene, encoding Serrate-type Notch ligand. JAG1 then binds to the Notch receptor on adjacent stem cells to induce Notch receptor proteolyses for the release of Notch intracellular domain (NICD). NICD is associated with CSL/RBPSUH and Mastermind (MAML1, MAML2, or MAML3) to activate Notch target genes, such as HES1 and HES5. Although WNT-dependent Notch signaling activation in intestinal stem cells is clarified, the effects of Notch signaling activation on WNT signaling in progenitor cells remain unclear. We searched for Notch-response element (NRE) in the promoter region of genes encoding secreted WNT signaling inhibitors, including DKK1, DKK2, DKK3, DKK4, SFRP1, SFRP2, SFRP3, SFRP4, SFRP5 and WIF1. Double NREs were identified within human DKK2 promoter by bioinformatics and human intelligence (Humint). The human DKK2 gene was characterized as Notch signaling target in intestinal stem cells. Because DKK2 is a key player in the stem cell signaling network, the DKK2 gene at human chromosome 4q25 is a candidate tumor suppressor gene inactivated due to epigenetic silencing and/or deletion. The chimpanzee DKK2 gene was identified within the NW_105990.1 genome sequence, while the cow Dkk2 gene was identified within the AC156664.2 and AC158038.2 genome sequences. Chimpanzee DKK2 and cow Dkk2 showed 98.5% and 95.8% total-amino-acid identity with human DKK2, respectively. Double NREs in human DKK2 promoter were conserved in chimpanzee DKK2 promoter, partially in rat Dkk2 promoter, but not in cow and mouse Dkk2 promoters. The Notch-DKK2 signaling loop, created or potentiated in primates, was complementary to WNT-DKK1 and BMP-IHH-SFRP1 signaling loops for negative regulation of canonical WNT signaling pathway. Together, these facts indicate that DKK2 promoter evolution resulted in the

  12. Notch signaling deregulation in multiple myeloma: A rational molecular target

    PubMed Central

    Garavelli, Silvia; Platonova, Natalia; Paoli, Alessandro; Basile, Andrea; Taiana, Elisa; Neri, Antonino; Chiaramonte, Raffaella

    2015-01-01

    Despite recent therapeutic advances, multiple myeloma (MM) is still an incurable neoplasia due to intrinsic or acquired resistance to therapy. Myeloma cell localization in the bone marrow milieu allows direct interactions between tumor cells and non-tumor bone marrow cells which promote neoplastic cell growth, survival, bone disease, acquisition of drug resistance and consequent relapse. Twenty percent of MM patients are at high-risk of treatment failure as defined by tumor markers or presentation as plasma cell leukemia. Cumulative evidences indicate a key role of Notch signaling in multiple myeloma onset and progression. Unlike other Notch-related malignancies, where the majority of patients carry gain-of-function mutations in Notch pathway members, in MM cell Notch signaling is aberrantly activated due to an increased expression of Notch receptors and ligands; notably, this also results in the activation of Notch signaling in surrounding stromal cells which contributes to myeloma cell proliferation, survival and migration, as well as to bone disease and intrinsic and acquired pharmacological resistance. Here we review the last findings on the mechanisms and the effects of Notch signaling dysregulation in MM and provide a rationale for a therapeutic strategy aiming at inhibiting Notch signaling, along with a complete overview on the currently available Notch-directed approaches. PMID:26308486

  13. Notch and the Skeleton▿

    PubMed Central

    Zanotti, Stefano; Canalis, Ernesto

    2010-01-01

    Notch receptors are transmembrane receptors that regulate cell fate decisions. There are four Notch receptors in mammals. Upon binding to members of the Delta and Jagged family of transmembrane proteins, Notch is cleaved and the Notch intracellular domain (NICD) is released. NICD then translocates to the nucleus, where it associates with the CBF-1, Suppressor of Hairless, and Lag-2 (CSL) and Mastermind-Like (MAML) proteins. This complex activates the transcription of Notch target genes, such as Hairy Enhancer of Split (Hes) and Hes-related with YRPF motif (Hey). Notch signaling is critical for the regulation of mesenchymal stem cell differentiation. Misexpression of Notch in skeletal tissue indicates a role as an inhibitor of skeletal development and postnatal bone formation. Overexpression of Notch inhibits endochondral bone formation and osteoblastic differentiation, causing severe osteopenia. Conditional inactivation of Notch in the skeleton causes an increase in cancellous bone volume and enhanced osteoblastic differentiation. Notch ligands are expressed in the hematopoietic stem cell niche and are critical for the regulation of hematopoietic stem cell self-renewal. Dysregulation of Notch signaling is the underlying cause of diseases affecting the skeletal tissue, including Alagille syndrome, spondylocostal dysostosis, and possibly, osteosarcoma. PMID:19995916

  14. Correlation of Notch1/Hes1 Genes Expression Levels in Egyptian Paediatric Patients with Newly Diagnosed and Persistent Primary Immune(Idiopathic) Thrombocytopenic Purpura.

    PubMed

    Gawdat, Rania Mohsen; Hammam, Amira Ahmed; Ezzat, Dina Ahmed

    2016-09-01

    Notch signalling is involved in the development of several autoimmune diseases, one of such diseases is ITP. The aim of this study was to investigate and compare the expression levels of Notch1 receptor and its target Hes1 gene in Egyptian paediatric ITP patients. Real-time quantitative reverse transcriptase polymerase chain reaction was used to analyse the expression levels of Notch1 and Hes1 in 42 children with primary ITP (22 newly diagnosed and 20 persistent) cases. Twenty age and sex matched non-ITP controls were included. The expression levels of Notch1 were higher in newly diagnosed and persistent cases than controls with high statistical significant difference (P value < 0.001, P < 0.001) respectively, similarly as regards the expression levels of HES1 (P value < 0.001, P < 0.007) respectively. A significant positive correlation was found between Notch1 and Hes1 expression levels in newly diagnosed cases (r = 0.587, P value = 0.004). There was an association between levels of both genes in most of ITP patients but Hes1 was markedly elevated than Notch1 in few cases. High expression levels of Notch1/Hes1 indicated the important role of Notch signalling in both newly diagnosed and persistent ITP. High expression levels of Hes1 than Notch1 may shed light on its value as a therapeutic target for future research in ITP. PMID:27429531

  15. NACK is an integral component of the Notch transcriptional activation complex and is critical for development and tumorigenesis.

    PubMed

    Weaver, Kelly L; Alves-Guerra, Marie-Clotilde; Jin, Ke; Wang, Zhiqiang; Han, Xiaoqing; Ranganathan, Prathibha; Zhu, Xiaoxia; DaSilva, Thiago; Liu, Wei; Ratti, Francesca; Demarest, Renee M; Tzimas, Cristos; Rice, Meghan; Vasquez-Del Carpio, Rodrigo; Dahmane, Nadia; Robbins, David J; Capobianco, Anthony J

    2014-09-01

    The Notch signaling pathway governs many distinct cellular processes by regulating transcriptional programs. The transcriptional response initiated by Notch is highly cell context dependent, indicating that multiple factors influence Notch target gene selection and activity. However, the mechanism by which Notch drives target gene transcription is not well understood. Herein, we identify and characterize a novel Notch-interacting protein, Notch activation complex kinase (NACK), which acts as a Notch transcriptional coactivator. We show that NACK associates with the Notch transcriptional activation complex on DNA, mediates Notch transcriptional activity, and is required for Notch-mediated tumorigenesis. We demonstrate that Notch1 and NACK are coexpressed during mouse development and that homozygous loss of NACK is embryonic lethal. Finally, we show that NACK is also a Notch target gene, establishing a feed-forward loop. Thus, our data indicate that NACK is a key component of the Notch transcriptional complex and is an essential regulator of Notch-mediated tumorigenesis and development.

  16. Notch signaling represses GATA4-induced expression of genes involved in steroid biosynthesis

    PubMed Central

    George, Rajani M.; Hahn, Katherine L.; Rawls, Alan; Viger, Robert S.; Wilson-Rawls, Jeanne

    2015-01-01

    Notch2 and Notch3 and genes of the Notch signaling network are dynamically expressed in developing follicles, where they are essential for granulosa cell proliferation and meiotic maturation. Notch receptors, ligands, and downstream effector genes are also expressed in testicular Leydig cells, predicting a potential role in regulating steroidogenesis. In this study, we sought to determine if Notch signaling in small follicles regulates the proliferation response of granulosa cells to follicle stimulating hormone and represses the up-regulation steroidogenic gene expression that occurs in response to FSH as the follicle grows. Inhibition of Notch signaling in small preantral follicles led to the up-regulation of the expression of genes in the steroid biosynthetic pathway. Similarly, progesterone secretion by MA-10 Leydig cells was significantly inhibited by constitutively active Notch. Together, these data indicated that Notch signaling inhibits steroidogenesis. GATA4 has been shown to be a positive regulator of steroidogenic genes, including steroidogenic acute regulatory protein, P450 aromatase, and 3B-hydroxysteroid dehydrogenase. We observed that Notch downstream effectors HEY1, HEY2, and HEYL are able to differentially regulate these GATA4-dependent promoters. These data are supported by the presence of HEY/HES binding sites in these promoters. These studies indicate that Notch signaling has a role in the complex regulation of the steroidogenic pathway. PMID:26183893

  17. Quinomycin A targets Notch signaling pathway in pancreatic cancer stem cells

    PubMed Central

    Ponnurangam, Sivapriya; Dandawate, Prasad R.; Dhar, Animesh; Tawfik, Ossama W.; Parab, Rajashri R.; Mishra, Prabhu Dutt; Ranadive, Prafull; Sharma, Rajiv; Mahajan, Girish; Umar, Shahid; Weir, Scott J.; Sugumar, Aravind; Jensen, Roy A.; Padhye, Subhash B.; Balakrishnan, Arun; Anant, Shrikant; Subramaniam, Dharmalingam

    2016-01-01

    Cancer stem cells (CSCs) appear to explain many aspects of the neoplastic evolution of tumors and likely account for enhanced therapeutic resistance following treatment. Dysregulated Notch signaling, which affects CSCs plays an important role in pancreatic cancer progression. We have determined the ability of Quinomycin to inhibit CSCs and the Notch signaling pathway. Quinomycin treatment resulted in significant inhibition of proliferation and colony formation in pancreatic cancer cell lines, but not in normal pancreatic epithelial cells. Moreover, Quinomycin affected pancreatosphere formation. The compound also decreased the expression of CSC marker proteins DCLK1, CD44, CD24 and EPCAM. In addition, flow cytometry studies demonstrated that Quinomycin reduced the number of DCLK1+ cells. Furthermore, levels of Notch 1–4 receptors, their ligands Jagged1, Jagged2, DLL1, DLL3, DLL4 and the downstream target protein Hes-1 were reduced. The γ-secretase complex proteins, Presenilin 1, Nicastrin, Pen2, and APH-1, required for Notch activation also exhibited decreased expression. Ectopic expression of the Notch Intracellular Domain (NICD) partially rescued the cells from Quinomycin mediated growth suppression. To determine the effect of Quinomycin on tumor growth in vivo, nude mice carrying tumor xenografts were administered Quinomycin intraperitoneally every day for 21 days. Treatment with the compound significantly inhibited tumor xenograft growth, coupled with significant reduction in the expression of CSC markers and Notch signaling proteins. Together, these data suggest that Quinomycin is a potent inhibitor of pancreatic cancer that targets the stem cells by inhibiting Notch signaling proteins. PMID:26673007

  18. NOTCH1 Regulates Matrix Gla Protein and Calcification Gene Networks in Human Valve Endothelium

    PubMed Central

    White, Mark P.; Theodoris, Christina V.; Liu, Lei; Collins, William J.; Blue, Kathleen W.; Lee, Joon Ho; Meng, Xianzhong; Robbins, Robert C.; Ivey, Kathryn N.; Srivastava, Deepak

    2015-01-01

    Valvular and vascular calcification are common causes of cardiovascular morbidity and mortality. Developing effective treatments requires understanding the molecular underpinnings of these processes. Shear stress is thought to play a role in inhibiting calcification. Furthermore, NOTCH1 regulates vascular and valvular endothelium, and human mutations in NOTCH1 can cause calcific aortic valve disease. Here, we determined the genome-wide impact of altering shear stress and NOTCH signaling on aortic valve endothelium. mRNA-sequencing of human aortic valve endothelial cells (HAVECs) with or without knockdown of NOTCH1, in the presence or absence of shear stress, revealed NOTCH1-dependency of the atherosclerosis-related gene connexin 40 (GJA5), and numerous repressors of endochondral ossification. Among these, Matrix GLA Protein (MGP) is highly expressed in aortic valve and vasculature, and inhibits soft tissue calcification by sequestering bone morphogenetic proteins (BMPs). Altering NOTCH1 levels affected MGP mRNA and protein in HAVECs. Furthermore, shear stress activated NOTCH signaling and MGP in a NOTCH1-dependent manner. NOTCH1 positively regulated endothelial MGP in vivo through specific binding motifs upstream of MGP. Our studies suggest that shear stress activates NOTCH1 in primary human aortic valve endothelial cells leading to downregulation of osteoblast-like gene networks that play a role in tissue calcification. PMID:25871831

  19. Dissecting the mechanisms of Notch induced hyperplasia

    PubMed Central

    Djiane, Alexandre; Krejci, Alena; Bernard, Frédéric; Fexova, Silvie; Millen, Katherine; Bray, Sarah J

    2013-01-01

    The outcome of the Notch pathway on proliferation depends on cellular context, being growth promotion in some, including several cancers, and growth inhibition in others. Such disparate outcomes are evident in Drosophila wing discs, where Notch overactivation causes hyperplasia despite having localized inhibitory effects on proliferation. To understand the underlying mechanisms, we have used genomic strategies to identify the Notch-CSL target genes directly activated during wing disc hyperplasia. Among them were genes involved in both autonomous and non-autonomous regulation of proliferation, growth and cell death, providing molecular explanations for many characteristics of Notch induced wing disc hyperplasia previously reported. The Notch targets exhibit different response patterns, which are shaped by both positive and negative feed-forward regulation between the Notch targets themselves. We propose, therefore, that both the characteristics of the direct Notch targets and their cross-regulatory relationships are important in coordinating the pattern of hyperplasia. PMID:23232763

  20. MicroRNA-101 regulates T-cell acute lymphoblastic leukemia progression and chemotherapeutic sensitivity by targeting Notch1

    PubMed Central

    Qian, Lu; Zhang, Wanggang; Lei, Bo; He, Aili; Ye, Lianhong; Li, Xingzhou; Dong, Xin

    2016-01-01

    The present study aimed to investigate the role of microRNA (miR)-101 in acute lymphoblastic leukemia progression and chemoresistance. Furthermore, a novel target gene of miR-101 was identified. Here, we confirmed that miR-101 was significantly downregulated in the blood samples of patients with T-cell acute lymphoblastic leukemia (T-ALL) compared with the healthy controls, as determined by reverse transcription quantitative polymerase chain reaction (RTqPCR) analysis. The in vitro experiments demonstrated that miR-101 significantly repressed the proliferation and invasion, and induced potent apoptosis in Jurkat cells, as determined by CCK-8, flow cytometer and cell invasion assays. Luciferase assay confirmed that Notch1 was a target gene of miR-101, and western blotting showed that miR-101 suppressed the expression of Notch1 at the protein level. Moreover, functional restoration assays revealed that Notch1 mediates the effects of miR-101 on Jurkat cell proliferation, apoptosis and invasion. miR-101 enhanced the sensitivity of Jurkat cells to the chemotherapeutic agent adriamycin. Taken together, our results show for the first time that miR-101 acts as a tumor suppressor in T-cell acute lymphoblastic leukaemia and it could enhance chemotherapeutic sensitivity. Furthermore, Notch1 was identified to be a novel target of miR-101. This study indicates that miR-101 may represent a potential therapeutic target for T-cell acute lymphoblastic leukemia intervention. PMID:27666896

  1. miR-139-5p sensitizes colorectal cancer cells to 5-fluorouracil by targeting NOTCH-1.

    PubMed

    Liu, Heyong; Yin, Yuan; Hu, Yaling; Feng, Yuyang; Bian, Zehua; Yao, Surui; Li, Min; You, Qingjun; Huang, Zhaohui

    2016-07-01

    Multidrug resistance (MDR), a phenomenon that often occurs with drug treatment and is characterized by relapse or attenuation of drug efficacy, is almost unavoidable in colorectal cancer (CRC) patients receiving 5-fluorouracil (5-FU)-based chemotherapy. MicroRNAs (miRNAs) are small noncoding RNAs that post-transcriptionally regulate gene expression. Our previous study has identified miR-139-5p as a potential tumor suppressor in CRC, but its role in chemoresistance of CRC has not been elucidated. In this study, we demonstrated that miR-139-5p was down-regulated either in CRC tumors receiving chemotherapy or in 5-FU-resistant CRC cell lines (HCT-8/5-FU and HCT-116/5-FU). Ectopic expression of miR-139-5p sensitized CRC cells to 5-FU by increasing 5-FU-induced apoptosis. In addition, miR-139-5p inhibited the expression of the miR-139-5p target gene NOTCH-1 and its downstream molecules MRP-1 and BCL-2, two key MDR-associated genes. Furthermore, silencing NOTCH-1 expression promoted the chemotherapeutic effects of 5-FU, and up-regulation of NOTCH-1 abrogated miR-139-5p-mediated sensitization to 5-FU in LoVo and HCT-116 cells. Taken together, our data indicate a new role of miR-139-5p/NOTCH-1 pathway in the drug resistance of CRC cells to 5-FU, which may be a promising therapeutic target for the anti-MDR treatment of CRC. PMID:27173050

  2. Multifunctional Core/Shell Nanoparticles Cross-linked Polyetherimide-folic Acid as Efficient Notch-1 siRNA Carrier for Targeted Killing of Breast Cancer

    PubMed Central

    Yang, Hong; Li, Ying; Li, Tingting; Xu, Min; Chen, Yin; Wu, Chunhui; Dang, Xitong; Liu, Yiyao

    2014-01-01

    In gene therapy, how genetic therapeutics can be efficiently and safely delivered into target tissues/cells remains a major obstacle to overcome. To address this issue, nanoparticles consisting of non-covalently coupled polyethyleneimine (PEI) and folic acid (FA) to the magnetic and fluorescent core/shell of Fe3O4@SiO2(FITC) was tested for their ability to deliver Notch-1 shRNA. Our results showed that Fe3O4@SiO2(FITC)/PEI-FA/Notch-1 shRNA nanoparticles are 64 nm in diameter with well dispersed and superparamagnetic. These nanoparticles with on significant cytotoxicity are capable of delivering Notch-1 shRNA into human breast cancer MDA-MB-231 cells with high efficiency while effectively protected shRNA from degradation by exogenous DNaseI and nucleases. Magnetic resonance (MR) imaging and fluorescence microscopy showed significant preferential uptake of Fe3O4@SiO2(FITC)/PEI-FA/Notch-1 shRNA nanocomplex by MDA-MB-231 cells. Transfected MDA-MB-231 cells exhibited significantly decreased expression of Notch-1, inhibited cell proliferation, and increased cell apoptosis, leading to the killing of MDA-MB-231 cells. In light of the magnetic targeting capabilities of Fe3O4@SiO2(FITC)/PEI-FA, our results show that by complexing with a second molecular targeting therapeutic, such as Notch-1 shRNA in this report, Fe3O4@SiO2(FITC)/PEI-FA can be exploited as a novel, non-viral, and concurrent targeting delivery system for targeted gene therapy as well as for MR imaging in cancer diagnosis. PMID:25400232

  3. Prevention against diffuse spinal cord astrocytoma: can the Notch pathway be a novel treatment target?

    PubMed Central

    Sun, Jian-jun; Wang, Zhen-yu; Li, Ling-song; Yu, Hai-yan; Xu, Yong-sheng; Wu, Hai-bo; Luo, Yi; Liu, Bin; Zheng, Mei; Mao, Jin-long; Lou, Xiao-hui

    2015-01-01

    This study was designed to investigate whether the Notch pathway is involved in the development of diffuse spinal cord astrocytomas. BALB/c nude mice received injections of CD133+ and CD133− cell suspensions prepared using human recurrent diffuse spinal cord astrocytoma tissue through administration into the right parietal lobe. After 7–11 weeks, magnetic resonance imaging was performed weekly. Xenografts were observed on the surfaces of the brains of mice receiving the CD133+ cell suspension, and Notch-immunopositive expression was observed in the xenografts. By contrast, no xenografts appeared in the identical position on the surfaces of the brains of mice receiving the CD133− cell suspension, and Notch-immunopositive expression was hardly detected either. Hematoxylin-eosin staining and immunohistochemical staining revealed xenografts on the convex surfaces of the brains of mice that underwent CD133+ astrocytoma transplantation. Some sporadic astroglioma cells showed pseudopodium-like structures, which extended into the cerebral white matter. However, it should be emphasized that the subcortex xenograft with Notch-immunopositive expression was found in the fourth mouse received injection of CD133− astrocytoma cells. However, these findings suggest that the Notch pathway plays an important role in the formation of astrocytomas, and can be considered a novel treatment target for diffuse spinal cord astrocytoma. PMID:25883623

  4. Notch signaling and proneural genes work together to control the neural building blocks for the initial scaffold in the hypothalamus

    PubMed Central

    Ware, Michelle; Hamdi-Rozé, Houda; Dupé, Valérie

    2014-01-01

    The vertebrate embryonic prosencephalon gives rise to the hypothalamus, which plays essential roles in sensory information processing as well as control of physiological homeostasis and behavior. While patterning of the hypothalamus has received much attention, initial neurogenesis in the developing hypothalamus has mostly been neglected. The first differentiating progenitor cells of the hypothalamus will give rise to neurons that form the nucleus of the tract of the postoptic commissure (nTPOC) and the nucleus of the mammillotegmental tract (nMTT). The formation of these neuronal populations has to be highly controlled both spatially and temporally as these tracts will form part of the ventral longitudinal tract (VLT) and act as a scaffold for later, follower axons. This review will cumulate and summarize the existing data available describing initial neurogenesis in the vertebrate hypothalamus. It is well-known that the Notch signaling pathway through the inhibition of proneural genes is a key regulator of neurogenesis in the vertebrate central nervous system. It has only recently been proposed that loss of Notch signaling in the developing chick embryo causes an increase in the number of neurons in the hypothalamus, highlighting an early function of the Notch pathway during hypothalamus formation. Further analysis in the chick and mouse hypothalamus confirms the expression of Notch components and Ascl1 before the appearance of the first differentiated neurons. Many newly identified proneural target genes were also found to be expressed during neuronal differentiation in the hypothalamus. Given the critical role that hypothalamic neural circuitry plays in maintaining homeostasis, it is particularly important to establish the targets downstream of this Notch/proneural network. PMID:25520625

  5. NOTCH1 inhibition enhances the efficacy of conventional chemotherapeutic agents by targeting head neck cancer stem cell

    PubMed Central

    Zhao, Zhi-Li; Zhang, Lu; Huang, Cong-Fa; Ma, Si-Rui; Bu, Lin-Lin; Liu, Jian-Feng; Yu, Guang-Tao; Liu, Bing; Gutkind, J. Silvio; Kulkarni, Ashok B.; Zhang, Wen-Feng; Sun, Zhi-Jun

    2016-01-01

    Cancer stem cells (CSCs) are considered responsible for tumor initiation and chemoresistance. This study was aimed to investigate the possibility of targeting head neck squamous cell carcinoma (HNSCC) by NOTCH1 pathway inhibition and explore the synergistic effect of combining NOTCH inhibition with conventional chemotherapy. NOTCH1/HES1 elevation was found in human HNSCC, especially in tissue post chemotherapy and lymph node metastasis, which is correlated with CSCs markers. NOTCH1 inhibitor DAPT (GSI-IX) significantly reduces CSCs population and tumor self-renewal ability in vitro and in vivo. Flow cytometry analysis showed that NOTCH1 inhibition reduces CSCs frequency either alone or in combination with chemotherapeutic agents, namely, cisplatin, docetaxel, and 5-fluorouracil. The combined strategy of NOTCH1 blockade and chemotherapy synergistically attenuated chemotherapy-enriched CSC population, promising a potential therapeutic exploitation in future clinical trial. PMID:27108536

  6. Targeting of miR9/NOTCH1 interaction reduces metastatic behavior in triple-negative breast cancer.

    PubMed

    Mohammadi-Yeganeh, Samira; Mansouri, Ardalan; Paryan, Mahdi

    2015-11-01

    Many reports have indicated deregulation of a variety of microRNAs (miRNAs) in human cancers. In this study, we appraised miR-9 correlation with NOTCH1 involved in Notch signaling in metastatic breast cancer. The Notch signaling pathway has been approved to be associated with the development and progression of many human cancers, including breast cancer, but the precise mechanism has remained unknown. To the best of our knowledge, this is the first study that introduces miR-9 and NOTCH1 correlation as an effective factor in breast cancer. We found that miR-9 expression was decreased in MDA-MB-231 breast cancer cells compared with MCF-10A normal breast cell line. However, NOTCH1 was upregulated in the metastatic breast cancer cells. Furthermore, luciferase assay revealed a significant inverse correlation between miR-9 and NOTCH1. Overexpression of Notch signaling via Notch1 intracellular domain in MDA-MB-231 cell line was suppressed by lentiviruses expressing miR-9. Taken together, the results obtained by MTT, flow cytometry, migration, and wound healing assays showed that it is possible to inhibit metastasis and induce pro-apoptotic state by induction of miR-9 expression in MDA-MB-231 cells but with no effect on cell proliferation. These results shows that miR-9, by direct targeting of NOTCH1, can reveal a suppressor-like activity in metastatic breast cancer cells.

  7. Targeting stem cell signaling pathways for drug discovery: advances in the Notch and Wnt pathways.

    PubMed

    An, Songzhu Michael; Ding, Qiang; Zhang, Jie; Xie, JingYi; Li, LingSong

    2014-06-01

    Signaling pathways transduce extracellular stimuli into cells through molecular cascades to regulate cellular functions. In stem cells, a small number of pathways, notably those of TGF-β/BMP, Hedgehog, Notch, and Wnt, are responsible for the regulation of pluripotency and differentiation. During embryonic development, these pathways govern cell fate specifications as well as the formation of tissues and organs. In adulthood, their normal functions are important for tissue homeostasis and regeneration, whereas aberrations result in diseases, such as cancer and degenerative disorders. In complex biological systems, stem cell signaling pathways work in concert as a network and exhibit crosstalk, such as the negative crosstalk between Wnt and Notch. Over the past decade, genetic and genomic studies have identified a number of potential drug targets that are involved in stem cell signaling pathways. Indeed, discovery of new targets and drugs for these pathways has become one of the most active areas in both the research community and pharmaceutical industry. Remarkable progress has been made and several promising drug candidates have entered into clinical trials. This review focuses on recent advances in the discovery of novel drugs which target the Notch and Wnt pathways.

  8. The Heterotaxy gene, GALNT11, glycosylates Notch to orchestrate cilia type and laterality

    PubMed Central

    Boskovski, Marko T.; Yuan, Shiaulou; Pedersen, Nis Borbye; Goth, Christoffer Knak; Makova, Svetlana; Clausen, Henrik; Brueckner, Martina; Khokha, Mustafa K.

    2013-01-01

    Heterotaxy (Htx) is a disorder of left-right (LR) body patterning, or laterality, that is associated with major congenital heart disease1. The etiology and mechanism underlying most human Htx is poorly understood. In vertebrates, laterality is initiated at the embryonic left-right organizer (LRO), where motile cilia generate leftward flow that is detected by immotile sensory cilia, which transduce flow into downstream asymmetric signals2–6. The mechanism that specifies these two cilia types remains unknown. We now show that the GalNAc-type O-glycosylation enzyme GALNT11 is crucial to such determination. We previously identified GALNT11 as a candidate disease gene in a patient with Htx7, and now demonstrate, in Xenopus, that galnt11 activates Notch signaling. GALNT11 O-glycosylates NOTCH1 peptides in vitro, thereby supporting a mechanism of Notch activation either by increasing ADAM17-mediated ectodomain shedding of the Notch receptor or by modification of specific EGF repeats. We further developed a quantitative live imaging technique for Xenopus LRO cilia and show that galnt11-mediated notch1 signaling modulates the spatial distribution and ratio of motile and immotile cilia at the LRO. galnt11 or notch1 depletion increases the ratio of motile cilia at the expense of immotile cilia and produces a laterality defect reminiscent of loss of the ciliary sensor Pkd2. In contrast, Notch overexpression decreases this ratio mimicking the ciliopathy, primary ciliary dyskinesia. Together, our data demonstrate that Galnt11 modifies Notch, establishing an essential balance between motile and immotile cilia at the LRO to determine laterality and identifies a novel mechanism for human Htx. PMID:24226769

  9. The heterotaxy gene GALNT11 glycosylates Notch to orchestrate cilia type and laterality.

    PubMed

    Boskovski, Marko T; Yuan, Shiaulou; Pedersen, Nis Borbye; Goth, Christoffer Knak; Makova, Svetlana; Clausen, Henrik; Brueckner, Martina; Khokha, Mustafa K

    2013-12-19

    Heterotaxy is a disorder of left-right body patterning, or laterality, that is associated with major congenital heart disease. The aetiology and mechanisms underlying most cases of human heterotaxy are poorly understood. In vertebrates, laterality is initiated at the embryonic left-right organizer, where motile cilia generate leftward flow that is detected by immotile sensory cilia, which transduce flow into downstream asymmetric signals. The mechanism that specifies these two cilia types remains unknown. Here we show that the N-acetylgalactosamine-type O-glycosylation enzyme GALNT11 is crucial to such determination. We previously identified GALNT11 as a candidate disease gene in a patient with heterotaxy, and now demonstrate, in Xenopus tropicalis, that galnt11 activates Notch signalling. GALNT11 O-glycosylates human NOTCH1 peptides in vitro, thereby supporting a mechanism of Notch activation either by increasing ADAM17-mediated ectodomain shedding of the Notch receptor or by modification of specific EGF repeats. We further developed a quantitative live imaging technique for Xenopus left-right organizer cilia and show that Galnt11-mediated Notch1 signalling modulates the spatial distribution and ratio of motile and immotile cilia at the left-right organizer. galnt11 or notch1 depletion increases the ratio of motile cilia at the expense of immotile cilia and produces a laterality defect reminiscent of loss of the ciliary sensor Pkd2. By contrast, Notch overexpression decreases this ratio, mimicking the ciliopathy primary ciliary dyskinesia. Together our data demonstrate that Galnt11 modifies Notch, establishing an essential balance between motile and immotile cilia at the left-right organizer to determine laterality, and reveal a novel mechanism for human heterotaxy. PMID:24226769

  10. The matricellular protein CCN1 controls retinal angiogenesis by targeting VEGF, Src homology 2 domain phosphatase-1 and Notch signaling.

    PubMed

    Chintala, Hemabindu; Krupska, Izabela; Yan, Lulu; Lau, Lester; Grant, Maria; Chaqour, Brahim

    2015-07-01

    Physiological angiogenesis depends on the highly coordinated actions of multiple angiogenic regulators. CCN1 is a secreted cysteine-rich and integrin-binding matricellular protein required for proper cardiovascular development. However, our understanding of the cellular origins and activities of this molecule is incomplete. Here, we show that CCN1 is predominantly expressed in angiogenic endothelial cells (ECs) at the leading front of actively growing vessels in the mouse retina. Endothelial deletion of CCN1 in mice using a Cre-Lox system is associated with EC hyperplasia, loss of pericyte coverage and formation of dense retinal vascular networks lacking the normal hierarchical arrangement of arterioles, capillaries and venules. CCN1 is a product of an immediate-early gene that is transcriptionally induced in ECs in response to stimulation by vascular endothelial growth factor (VEGF). We found that CCN1 activity is integrated with VEGF receptor 2 (VEGF-R2) activation and downstream signaling pathways required for tubular network formation. CCN1-integrin binding increased the expression of and association between Src homology 2 domain-containing protein tyrosine phosphatase-1 (SHP-1) and VEGF-R2, which leads to rapid dephosphorylation of VEGF-R2 tyrosine, thus preventing EC hyperproliferation. Predictably, CCN1 further brings receptors/signaling molecules into proximity that are otherwise spatially separated. Furthermore, CCN1 induces integrin-dependent Notch activation in cultured ECs, and its targeted gene inactivation in vivo alters Notch-dependent vascular specification and remodeling, suggesting that functional levels of Notch signaling requires CCN1 activity. These data highlight novel functions of CCN1 as a naturally optimized molecule, fine-controlling key processes in physiological angiogenesis and safeguarding against aberrant angiogenic responses.

  11. Novel mutation of the NOTCH3 gene in a Polish family with CADASIL.

    PubMed

    Buczek, Julia; Błażejewska-Hyżorek, Beata; Cudna, Agnieszka; Lusawa, Małgorzata; Lewandowska, Eliza; Kurkowska-Jastrzębska, Iwona; Członkowska, Anna

    2016-01-01

    Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited small blood vessels disease caused by mutations in the gene encoding the neurogenic locus notch homolog protein 3 (NOTCH 3). We present a Polish family with a previously unreported novel mutation in exon 12 c.1851C>C/G of the NOTCH3 gene and varying disease expression. One of the two family members with the confirmed mutation presented with all the main CADASIL symptoms; while, his affected father was nearly asymptomatic. Both family members had epilepsy, coronary artery disease, and abdominal aorta aneurysm. Our observation confirms there is phenotypic variability in CADASIL not only between, but also within, families carrying the same mutation. PMID:27375140

  12. Cloning and expression characteristics of the notch-associated gene BmE(spl)mγ from silkworm, Bombyx mori.

    PubMed

    Liu, Min; Wang, Chan; Li, Dan; Liu, Yue; Sheng, Qing; Lv, Zhengbing; Yu, Wei; Wang, Dan; Zhang, Yaozhou; Nie, Zuoming

    2014-08-01

    The E(spl)mγ gene in Drosophila is a regulatory target gene downstream of the Notch pathway. BmE(spl)mγ (Bombyx mori, E(spl)mγ) is an ortholog of the Drosophila E(spl)mγ gene, and the gene encodes a protein with 248 amino acid residues. This gene was cloned and overexpressed in Escherichia coli BL21(DE3). The recombinant protein was purified and subsequently used to generate a rabbit polyclonal antibody. Western blotting analyses showed that BmE(spl)mγ expression is high in pupa and egg, and low in larva and moth. In the fifth instar larva, the protein levels are high in head, epidermis, sexual gland, trachea, and the fatbody and low in the Malpighian tubule, hemolymph, gut, and silk gland. The further immunohistochemical analyses also showed higher BmE(spl)mγ expression in the head of fifth instar larva and pupa. Of the four moth parts studied, the thorax had the highest expression level. Thus, BmE(spl)mγ might be associated with neurogenesis in silkworm. Furthermore, DAPT (a γ-secretase inhibitor and an indirect inhibitor of Notch) blocking experiments showed that higher concentrations of the blocking agent and a longer processing time reduce the transcription levels of the BmE(spl)mγ gene, demonstrating that the silkworm BmE(spl)mγ gene is associated with the Notch signal pathway. These findings suggest that the function of BmE(spl)mγ may be similar to that of its Drosophila homolog.

  13. Exploring the potential relationship between Notch pathway genes expression and their promoter methylation in mice hippocampal neurogenesis.

    PubMed

    Zhang, Zhen; Gao, Feng; Kang, Xiaokui; Li, Jia; Zhang, Litong; Dong, Wentao; Jin, Zhangning; Li, Fan; Gao, Nannan; Cai, Xinwang; Yang, Shuyuan; Zhang, Jianning; Ren, Xinliang; Yang, Xinyu

    2015-04-01

    The Notch pathway is a highly conserved pathway that regulates hippocampal neurogenesis during embryonic development and adulthood. It has become apparent that intracellular epigenetic modification including DNA methylation is deeply involved in fate specification of neural stem cells (NSCs). However, it is still unclear whether the Notch pathway regulates hippocampal neurogenesis by changing the Notch genes' DNA methylation status. Here, we present the evidence from DNA methylation profiling of Notch1, Hes1 and Ngn2 promoters during neurogenesis in the dentate gyrus (DG) of postnatal, adult and traumatic brains. We observed the expression of Notch1, Hes1 and Ngn2 in hippocampal DG with qPCR, Western blot and immunofluorescence staining. In addition, we investigated the methylation status of Notch pathway genes using the bisulfite sequencing PCR (BSP) method. The number of Notch1 or Hes1 (+) and BrdU (+) cells decreased in the subgranular zone (SGZ) of the DG in the hippocampus following TBI. Nevertheless, the number of Ngn2-positive cells in the DG of injured mice was markedly higher than in the DG of non-TBI mice. Accordingly, the DNA methylation level of the three gene promoters changed with their expression in the DG. These findings suggest that the strict spatio-temporal expression of Notch effector genes plays an important role during hippocampal neurogenesis and suggests the possibility that Notch1, Hes1 and Ngn2 were regulated by changing some specific CpG sites of their promoters to further orchestrate neurogenesis in vivo.

  14. The Role of Notch Receptors in Transcriptional Regulation

    PubMed Central

    WANG, HONGFANG; ZANG, CHONGZHI; LIU, X. SHIRLEY; ASTER, JON C.

    2015-01-01

    Notch signaling has pleiotropic context-specific functions that have essential roles in many processes, including embryonic development and maintenance and homeostasis of adult tissues. Aberrant Notch signaling (both hyper- and hypoactive) is implicated in a number of human developmental disorders and many cancers. Notch receptor signaling is mediated by tightly regulated proteolytic cleavages that lead to the assembly of a nuclear Notch transcription complex, which drives the expression of downstream target genes and thereby executes Notch’s functions. Thus, understanding regulation of gene expression by Notch is central to deciphering how Notch carries out its many activities. Here, we summarize the recent findings pertaining to the complex interplay between the Notch transcriptional complex and interacting factors involved in transcriptional regulation, including co-activators, cooperating transcription factors, and chromatin regulators, and discuss emerging data pertaining to the role of Notch-regulated noncoding RNAs in transcription. PMID:25418913

  15. Altered Notch signaling resulting from expression of a WAMTP1-MAML2 gene fusion in mucoepidermoid carcinomas and benign Warthin's tumors.

    PubMed

    Enlund, Fredrik; Behboudi, Afrouz; Andrén, Ywonne; Oberg, Camilla; Lendahl, Urban; Mark, Joachim; Stenman, Göran

    2004-01-01

    Chromosome translocations in neoplasia commonly result in fusion genes that may encode either novel fusion proteins or normal, but ectopically expressed proteins. Here we report the cloning of a novel fusion gene in a common type of salivary and bronchial gland tumor, mucoepidermoid carcinomas (MEC), as well as in benign Warthin's tumors (WATs). The fusion, which results from a t(11;19)(q21-22;p13) translocation, creates a chimeric gene in which exon 1 of a novel gene of unknown function, designated WAMTP1, is linked to exons 2-5 of the recently identified Mastermind-like Notch coactivator MAML2. In the fusion protein, the N-terminal basic domain of MAML2, which is required for binding to intracellular Notch (Notch ICD), is replaced by an unrelated N-terminal sequence from WAMTP1. Mutation analysis of the N-terminus of WAMTP1-MAML2 identified two regions of importance for nuclear localization (amino acids 11-20) and for colocalization with MAML2 and Notch1 ICD in nuclear granules (amino acids 21-42). Analyses of the Notch target genes HES5 and MASH1 in MEC tumors with and without the WAMTP1-MAML2 fusion revealed upregulation of HES5 and downregulation of MASH1 in fusion positive MECs compared to normal salivary gland tissue and MECs lacking the fusion. These findings suggest that altered Notch signaling plays an important role in the genesis of benign and malignant neoplasms of salivary and bronchial gland origin.

  16. Buyang Huanwu decoction up-regulates Notch1 gene expression in injured spinal cord.

    PubMed

    Guo, Zhan-Peng; Huang, Mi-Na; Liu, An-Qi; Yuan, Ya-Jiang; Zhao, Jian-Bo; Mei, Xi-Fan

    2015-08-01

    Expression of genes in the Notch signaling pathway is altered in the injured spinal cord, which indicates that Notch participates in repair after spinal cord injury. Buyang Huanwu decoction, a traditional Chinese herbal preparation, can promote the growth of nerve cells and nerve fibers; however, it is unclear whether Buyang Huanwu decoction affects the Notch signaling pathway in injured spinal cord. In this study, a rat model was established by injuring the T10 spinal cord. At 2 days after injury, rats were intragastrically administered 2 mL of 0.8 g/mL Buyang Huanwu decoction daily until sacrifice. Real-time reverse transcription polymerase chain reaction analysis demonstrated that at 7, 14 and 28 days after injury, the expression of Notch1 was increased in the Buyang Huanwu decoction group compared with controls. These findings confirm that Buyang Huanwu decoction can promote the expression of Notch1 in rats with incomplete spinal cord injury, and may indicate a mechanism to promote the repair of spinal cord injury.

  17. Regulation of Nematostella neural progenitors by SoxB, Notch and bHLH genes.

    PubMed

    Richards, Gemma Sian; Rentzsch, Fabian

    2015-10-01

    Notch signalling, SoxB and Group A bHLH 'proneural' genes are conserved regulators of the neurogenic program in many bilaterians. However, the ancestry of their functions and interactions is not well understood. We address this question in the sea anemone Nematostella vectensis, a representative of the Cnidaria, the sister clade to the Bilateria. It has previously been found that the SoxB orthologue NvSoxB(2) is expressed in neural progenitor cells (NPCs) in Nematostella and promotes the development of both neurons and nematocytes, whereas Notch signalling has been implicated in the negative regulation of neurons and the positive regulation of nematocytes. Here, we clarify the role of Notch by reporting that inhibition of Notch signalling increases the numbers of both neurons and nematocytes, as well as increasing the number of NvSoxB(2)-expressing cells. This suggests that Notch restricts neurogenesis by limiting the generation of NPCs. We then characterise NvAth-like (Atonal/Neurogenin family) as a positive regulator of neurogenesis that is co-expressed with NvSoxB(2) in a subset of dividing NPCs, while we find that NvAshA (Achaete-scute family) and NvSoxB(2) are co-expressed in non-dividing cells only. Reciprocal knockdown experiments reveal a mutual requirement for NvSoxB(2) and NvAth-like in neural differentiation; however, the primary expression of each gene is independent of the other. Together, these data demonstrate that Notch signalling and NvSoxB(2) regulate Nematostella neural progenitors via parallel yet interacting mechanisms; with different aspects of these interactions being shared with Drosophila and/or vertebrate neurogenesis. PMID:26443634

  18. Regulation of Nematostella neural progenitors by SoxB, Notch and bHLH genes

    PubMed Central

    Richards, Gemma Sian; Rentzsch, Fabian

    2015-01-01

    Notch signalling, SoxB and Group A bHLH ‘proneural’ genes are conserved regulators of the neurogenic program in many bilaterians. However, the ancestry of their functions and interactions is not well understood. We address this question in the sea anemone Nematostella vectensis, a representative of the Cnidaria, the sister clade to the Bilateria. It has previously been found that the SoxB orthologue NvSoxB(2) is expressed in neural progenitor cells (NPCs) in Nematostella and promotes the development of both neurons and nematocytes, whereas Notch signalling has been implicated in the negative regulation of neurons and the positive regulation of nematocytes. Here, we clarify the role of Notch by reporting that inhibition of Notch signalling increases the numbers of both neurons and nematocytes, as well as increasing the number of NvSoxB(2)-expressing cells. This suggests that Notch restricts neurogenesis by limiting the generation of NPCs. We then characterise NvAth-like (Atonal/Neurogenin family) as a positive regulator of neurogenesis that is co-expressed with NvSoxB(2) in a subset of dividing NPCs, while we find that NvAshA (Achaete-scute family) and NvSoxB(2) are co-expressed in non-dividing cells only. Reciprocal knockdown experiments reveal a mutual requirement for NvSoxB(2) and NvAth-like in neural differentiation; however, the primary expression of each gene is independent of the other. Together, these data demonstrate that Notch signalling and NvSoxB(2) regulate Nematostella neural progenitors via parallel yet interacting mechanisms; with different aspects of these interactions being shared with Drosophila and/or vertebrate neurogenesis. PMID:26443634

  19. Activation of the NOTCH pathway in head and neck cancer.

    PubMed

    Sun, Wenyue; Gaykalova, Daria A; Ochs, Michael F; Mambo, Elizabeth; Arnaoutakis, Demetri; Liu, Yan; Loyo, Myriam; Agrawal, Nishant; Howard, Jason; Li, Ryan; Ahn, Sun; Fertig, Elana; Sidransky, David; Houghton, Jeffery; Buddavarapu, Kalyan; Sanford, Tiffany; Choudhary, Ashish; Darden, Will; Adai, Alex; Latham, Gary; Bishop, Justin; Sharma, Rajni; Westra, William H; Hennessey, Patrick; Chung, Christine H; Califano, Joseph A

    2014-02-15

    NOTCH1 mutations have been reported to occur in 10% to 15% of head and neck squamous cell carcinomas (HNSCC). To determine the significance of these mutations, we embarked upon a comprehensive study of NOTCH signaling in a cohort of 44 HNSCC tumors and 25 normal mucosal samples through a set of expression, copy number, methylation, and mutation analyses. Copy number increases were identified in NOTCH pathway genes, including the NOTCH ligand JAG1. Gene set analysis defined a differential expression of the NOTCH signaling pathway in HNSCC relative to normal tissues. Analysis of individual pathway-related genes revealed overexpression of ligands JAG1 and JAG2 and receptor NOTCH3. In 32% of the HNSCC examined, activation of the downstream NOTCH effectors HES1/HEY1 was documented. Notably, exomic sequencing identified 5 novel inactivating NOTCH1 mutations in 4 of the 37 tumors analyzed, with none of these tumors exhibiting HES1/HEY1 overexpression. Our results revealed a bimodal pattern of NOTCH pathway alterations in HNSCC, with a smaller subset exhibiting inactivating NOTCH1 receptor mutations but a larger subset exhibiting other NOTCH1 pathway alterations, including increases in expression or gene copy number of the receptor or ligands as well as downstream pathway activation. Our results imply that therapies that target the NOTCH pathway may be more widely suitable for HNSCC treatment than appreciated currently.

  20. Activation of the NOTCH pathway in Head and Neck Cancer

    PubMed Central

    Sun, Wenyue; Gaykalova, Daria A.; Ochs, Michael F.; Mambo, Elizabeth; Arnaoutakis, Demetri; Liu, Yan; Loyo, Myriam; Agrawal, Nishant; Howard, Jason; Li, Ryan; Ahn, Sun; Fertig, Elana; Sidransky, David; Houghton, Jeffery; Buddavarapu, Kalyan; Sanford, Tiffany; Choudhary, Ashish; Darden, Will; Adai, Alex; Latham, Gary; Bishop, Justin; Sharma, Rajni; Westra, William H.; Hennessey, Patrick; Chung, Christine H.; Califano, Joseph A.

    2014-01-01

    NOTCH1 mutations have been reported to occur in 10 to 15% of head and neck squamous cell carcinomas (HNSCC). To determine the significance of these mutations, we embarked upon a comprehensive study of NOTCH signaling in a cohort of 44 HNSCC tumors and 25 normal mucosal samples through a set of expression, copy number, methylation and mutation analyses. Copy number increases were identified in NOTCH pathway genes including the NOTCH ligand JAG1. Gene set analysis defined a differential expression of the NOTCH signaling pathway in HNSCC relative to normal tissues. Analysis of individual pathway-related genes revealed overexpression of ligands JAG1 and JAG2 and receptor NOTCH3. In 32% of the HNSCC examined, activation of the downstream NOTCH effectors HES1/HEY1 was documented. Notably, exomic sequencing identified 5 novel inactivating NOTCH1 mutations in 4/37 of the tumors analyzed, with none of these tumors exhibiting HES1/HEY1 overexpression. Our results revealed a bimodal pattern of NOTCH pathway alterations in HNSCC, with a smaller subset exhibiting inactivating NOTCH1 receptors mutations but a larger subset exhibiting other NOTCH1 pathway alterations, including increases in expression or gene copy number of the receptor or ligands as well as downstream pathway activation. Our results imply that therapies that target the NOTCH pathway may be more widely suitable for HNSCC treatment than appreciated currently. PMID:24351288

  1. Association of the NOTCH4 Gene Polymorphism rs204993 with Schizophrenia in the Chinese Han Population.

    PubMed

    Zhang, Bao; Fan, Qian Rui; Li, Wen Hao; Lu, Ning; Fu, Dong Ke; Kang, Yan Jie; Wang, Na; Li, Teng; Wen, Xiao Peng; Li, Da Xu

    2015-01-01

    NOTCH4 regulates signaling pathways associated with neuronal maturation, a process involved in the development and patterning of the central nervous system. The NOTCH4 gene has also been identified as a possible susceptibility gene for schizophrenia (SCZ). The objective of this study was to examine the relationship between NOTCH4 polymorphisms and SCZ in the Chinese Han population. The rs2071287 and rs204993 polymorphisms of the NOTCH4 gene were analyzed in 443 patients with SCZ and 628 controls of Han Chinese descent. Single SNP allele-, genotype-, and gender-specific associations were analyzed using different models (i.e., additive, dominant, and recessive models). This association study revealed that the rs204993 polymorphism is significantly associated with susceptibility for SCZ and that the AA genotype of rs204993 is associated with a higher risk for SCZ (P = 0.027; OR = 1.460; 95% CI, 1.043-2.054). Our data are consistent with those obtained in previous studies that suggested that rs204993 is associated with SCZ and that the AA genotype of rs204993 demonstrates a higher risk. Further large-scale association analyses in Han Chinese populations are warranted. PMID:26605328

  2. Notch1 Pathway Activation Results from the Epigenetic Abrogation of Notch-Related MicroRNAs in Mycosis Fungoides.

    PubMed

    Gallardo, Fernando; Sandoval, Juan; Díaz-Lagares, Angel; Garcia, Ricard; D'Altri, Teresa; González, Jessica; Alegre, Victor; Servitje, Octavio; Crujeiras, Ana-Belén; Stefánsson, Ólafur-Andri; Espinet, Blanca; Hernández, Maria-Inmaculada; Bellosillo, Beatriz; Esteller, Manel; Pujol, Ramon-Maria; Bigas, Anna; Espinosa, Lluis

    2015-12-01

    Notch is a family of transmembrane receptors that participate in the regulation of cell differentiation, proliferation, and stemness. Notch pathway activation has also been found associated with different human cancers including primary cutaneous T-cell lymphomas (CTCL). The elucidation of the mechanisms driving Notch activation in these particular diseases has remained elusive. Here we studied the possibility that DNA methylation at Notch pathway gene promoters and/or deregulation of Notch-associated microRNAs contribute to activate Notch in mycosis fungoides (MF). By genome-wide DNA methylation analysis, we failed to detect any consistent methylation at the Notch1, the Notch-ligand Jagged1, or the Notch-target Hes1 gene promoters, but found a significant methylation of the Notch-related microRNAs, in particular miR-200c and miR-124. Downregulation of miR-200c is associated with overexpression of Jagged1, concomitant to Notch1 activation. CTCL cell lines were infected with lentiviral vector encoding for miR-200c and ectopic expression of miR-200c in CTCL lines resulted in Jagged1 protein downregulation associated with a reduction in the levels of active Notch1. Our study deciphers an epigenetic mechanism regulating the Notch pathway in (MF) that might contribute to the future design of more specific therapeutic strategies. PMID:26302069

  3. Modulation of gene expression via overlapping binding sites exerted by ZNF143, Notch1 and THAP11.

    PubMed

    Ngondo-Mbongo, Richard Patryk; Myslinski, Evelyne; Aster, Jon C; Carbon, Philippe

    2013-04-01

    ZNF143 is a zinc-finger protein involved in the transcriptional regulation of both coding and non-coding genes from polymerase II and III promoters. Our study deciphers the genome-wide regulatory role of ZNF143 in relation with the two previously unrelated transcription factors Notch1/ICN1 and thanatos-associated protein 11 (THAP11) in several human and murine cells. We show that two distinct motifs, SBS1 and SBS2, are associated to ZNF143-binding events in promoters of >3000 genes. Without co-occupation, these sites are also bound by Notch1/ICN1 in T-lymphoblastic leukaemia cells as well as by THAP11, a factor involved in self-renewal of embryonic stem cells. We present evidence that ICN1 binding overlaps with ZNF143 binding events at the SBS1 and SBS2 motifs, whereas the overlap occurs only at SBS2 for THAP11. We demonstrate that the three factors modulate expression of common target genes through the mutually exclusive occupation of overlapping binding sites. The model we propose predicts that the binding competition between the three factors controls biological processes such as rapid cell growth of both neoplastic and stem cells. Overall, our study establishes a novel relationship between ZNF143, THAP11 and ICN1 and reveals important insights into ZNF143-mediated gene regulation. PMID:23408857

  4. Modulation of gene expression via overlapping binding sites exerted by ZNF143, Notch1 and THAP11

    PubMed Central

    Ngondo-Mbongo, Richard Patryk; Myslinski, Evelyne; Aster, Jon C.; Carbon, Philippe

    2013-01-01

    ZNF143 is a zinc-finger protein involved in the transcriptional regulation of both coding and non-coding genes from polymerase II and III promoters. Our study deciphers the genome-wide regulatory role of ZNF143 in relation with the two previously unrelated transcription factors Notch1/ICN1 and thanatos-associated protein 11 (THAP11) in several human and murine cells. We show that two distinct motifs, SBS1 and SBS2, are associated to ZNF143-binding events in promoters of >3000 genes. Without co-occupation, these sites are also bound by Notch1/ICN1 in T-lymphoblastic leukaemia cells as well as by THAP11, a factor involved in self-renewal of embryonic stem cells. We present evidence that ICN1 binding overlaps with ZNF143 binding events at the SBS1 and SBS2 motifs, whereas the overlap occurs only at SBS2 for THAP11. We demonstrate that the three factors modulate expression of common target genes through the mutually exclusive occupation of overlapping binding sites. The model we propose predicts that the binding competition between the three factors controls biological processes such as rapid cell growth of both neoplastic and stem cells. Overall, our study establishes a novel relationship between ZNF143, THAP11 and ICN1 and reveals important insights into ZNF143-mediated gene regulation. PMID:23408857

  5. Gene targeting in livestock.

    PubMed

    Thomson, A J; Marques, M M; McWhir, J

    2003-01-01

    The development of nuclear transfer from tissue culture cells in livestock made it possible in principle to produce animals with subtle, directed genetic changes by in vitro modification of nuclear donor cells. In the short period since nuclear transfer was first performed, gene targeting in livestock has become a reality. Although gene targeting has immediate potential in biotechnology, it is unclear whether there are practical agricultural applications, at present. The first livestock targeting experiments have been directed at engineering animals either to render their organs immunologically compatible for human transplantation, or for improving the commercial production of recombinant proteins in the transgenic mammary gland. All successful examples of targeting have involved target loci that are expressed in the nuclear donor cell line. Two important barriers to the further development of this technology are adapting protocols for non-expressed genes and modifying procedures to enhance the lifespan of targeted cells in vitro. This review provides data that illustrate the difficulty in targeting non-expressed genes and discusses some of the practical issues associated with providing targeted nuclear donor cells that are competent for nuclear transfer.

  6. Epithelial expression and chromosomal location of human TLE genes: Implications for notch signaling and neoplasia

    SciTech Connect

    Liu, Yanling; Dehni, Ghassan; Stifani, S.

    1996-01-01

    The TLE genes are the human homologues of Drosophila groucho, a member of the Notch signaling pathway. This pathway controls a number of different cell-fate choices in invertebrates and vertebrates. We are interested in investigating the functions of the TLE gene family during epithelial determination and carcinogenesis. We show that expression of individual TLE genes correlates with immature epithelial cells that are progressing toward their terminally differentiated state, suggesting a role during epithelial differentiation. In both normal tissues and conditions resulting from incorrect or incomplete maturation events, such as metaplastic and neoplastic transformations, TLE expression is elevated and coincides with Notch expression, implicating these molecules in the maintenance of the undifferentiated state in epithelial cells. We also show that TLE1 and TLE2 are organized in a tandem array at chromosomal location 19p13.3, while TLE3 maps to 15q22. 26 refs., 4 figs.

  7. Chimeric analysis of Notch2 function: a role for Notch2 in the development of the roof plate of the mouse brain.

    PubMed

    Kadokawa, Yuzo; Marunouchi, Tohru

    2002-10-01

    Notch proteins are transmembrane receptors involved in cell-fate determination throughout development. Targeted disruption of either the Notch1 or Notch2 gene in mice results in embryonic lethality around embryonic day (E) 10.5 with widespread cell death. Although Notch1-deficient mice show disorganized somitogenesis, Notch2 mutants did not show definitive abnormalities in any tissue expressing high levels of the Notch2 gene, including the central nervous system. To study Notch2 function in development beyond the embryonic lethal stage, we performed chimeric analysis between Notch2 mutant and wild-type mouse embryos. Chimeric embryos developed normally and homozygous Notch2 mutant-specific cell death was not observed. Although chimeric embryos showed normal mosaicism until E9.5 in all tissues studied to date, Notch2 homozygous mutant cells failed to contribute to formation of the roof plate of the diencephalon and mesencephalon at later developmental stages, when Notch2 is normally expressed at high levels at there. Furthermore, Notch2 heterozygous mutant cells were also excluded from the roof plate of the chimera, however, Notch2 heterozygous mutant mice developed normally. We also showed that Wnt-1 and Mash1 expression patterns at the roof plate were disorganized in Notch2 homozygous mutant embryos. These results indicate that Notch2 plays an important role in development of the roof plate of the diencephalon and mesencephalon, and suggest that cellular rearrangement is involved in this process.

  8. PlexinD1 Is a Novel Transcriptional Target and Effector of Notch Signaling in Cancer Cells

    PubMed Central

    Rehman, Michael; Capparuccia, Lorena

    2016-01-01

    The secreted semaphorin Sema3E controls cell migration and invasiveness in cancer cells. Sema3E-receptor, PlexinD1, is frequently upregulated in melanoma, breast, colon, ovarian and prostate cancers; however, the mechanisms underlying PlexinD1 upregulation and the downstream events elicited in tumor cells are still unclear. Here we show that the canonical RBPjk-dependent Notch signaling cascade controls PlexinD1 expression in primary endothelial and cancer cells. Transcriptional activation was studied by quantitative PCR and promoter activity reporter assays. We found that Notch ligands and constitutively activated intracellular forms of Notch receptors upregulated PlexinD1 expression; conversely RNAi-based knock-down, or pharmacological inhibition of Notch signaling by gamma-secretase inhibitors, downregulated PlexinD1 levels. Notably, both Notch1 and Notch3 expression positively correlates with PlexinD1 levels in prostate cancer, as well as in other tumor types. In prostate cancer cells, Sema3E-PlexinD1 axis was previously reported to regulate migration; however, implicated mechanisms were not elucidated. Here we show that in these cells PlexinD1 activity induces the expression of the transcription factor Slug, downregulates E-cadherin levels and enhances cell migration. Moreover, our mechanistic data identify PlexinD1 as a pivotal mediator of this signaling axis downstream of Notch in prostate cancer cells. In fact, on one hand, PlexinD1 is required to mediate cell migration and E-cadherin regulation elicited by Notch. On the other hand, PlexinD1 upregulation is sufficient to induce prostate cancer cell migration and metastatic potential in mice, leading to functional rescue in the absence of Notch. In sum, our work identifies PlexinD1 as a novel transcriptional target induced by Notch signaling, and reveals its role promoting prostate cancer cell migration and downregulating E-cadherin levels in Slug-dependent manner. Collectively, these findings suggest that

  9. R54C Mutation of NOTCH3 Gene in the First Rungus Family with CADASIL

    PubMed Central

    Lim, Kheng-Seang; Tan, Ai-Huey; Lim, Chun-Shen; Chua, Kek-Heng; Lee, Ping-Chin; Ramli, Norlisah; Rajahram, Giri Shan; Hussin, Fatimah Tina; Wong, Kum-Thong; Bhattacharjee, Meenakshi B.; Ng, Ching-Ching

    2015-01-01

    Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a rare hereditary stroke caused by mutations in NOTCH3 gene. We report the first case of CADASIL in an indigenous Rungus (Kadazan-Dusun) family in Kudat, Sabah, Malaysia confirmed by a R54C (c.160C>T, p.Arg54Cys) mutation in the NOTCH3. This mutation was previously reported in a Caucasian and two Korean cases of CADASIL. We recruited two generations of the affected Rungus family (n = 9) and found a missense mutation (c.160C>T) in exon 2 of NOTCH3 in three siblings. Two of the three siblings had severe white matter abnormalities in their brain MRI (Scheltens score 33 and 50 respectively), one of whom had a young stroke at the age of 38. The remaining sibling, however, did not show any clinical features of CADASIL and had only minimal changes in her brain MRI (Scheltens score 17). This further emphasized the phenotype variability among family members with the same mutation in CADASIL. This is the first reported family with CADASIL in Rungus subtribe of Kadazan-Dusun ethnicity with a known mutation at exon 2 of NOTCH3. The penetrance of this mutation was not complete during the course of this study. PMID:26270344

  10. The Notch signaling pathway as a mediator of tumor survival

    PubMed Central

    Pine, Sharon R.

    2013-01-01

    The Notch signaling pathway is evolutionarily conserved and responsible for cell fate determination in the developing embryo and mature tissue. At the molecular level, ligand binding activates Notch signaling by liberating the Notch intracellular domain, which then translocates into the nucleus and activates gene transcription. Despite the elegant simplicity of this pathway, which lacks secondary messengers or a signaling cascade, Notch regulates gene expression in a highly context- and cell-type-dependent manner. Notch signaling is frequently dysregulated, most commonly by overactivation, across many cancers and confers a survival advantage on tumors, leading to poorer outcomes for patients. Recent studies demonstrate how Notch signaling increases tumor cell proliferation and provide evidence that active Notch signaling maintains the cancer stem-cell pool, induces epithelial–mesenchymal transition and promotes chemoresistance. These studies imply that pharmacological inhibition of Notch signaling may refine control of cancer therapy and improve patient survival. Gamma secretase inhibitors (GSIs) are drugs that inhibit Notch signaling and may be successful in controlling cancer cell growth in conjunction with standard chemotherapy, but substantial side effects have hampered their widespread use. Recent efforts have been aimed at the development of antibodies against specific Notch receptors and ligands with the hope of limiting side effects while providing the same therapeutic benefit as GSIs. Together, studies characterizing Notch signaling and modulation have offered hope that refined methods targeting Notch may become powerful tools in anticancer therapeutics. PMID:23585460

  11. The Notch signaling pathway as a mediator of tumor survival.

    PubMed

    Capaccione, Kathleen M; Pine, Sharon R

    2013-07-01

    The Notch signaling pathway is evolutionarily conserved and responsible for cell fate determination in the developing embryo and mature tissue. At the molecular level, ligand binding activates Notch signaling by liberating the Notch intracellular domain, which then translocates into the nucleus and activates gene transcription. Despite the elegant simplicity of this pathway, which lacks secondary messengers or a signaling cascade, Notch regulates gene expression in a highly context- and cell-type-dependent manner. Notch signaling is frequently dysregulated, most commonly by overactivation, across many cancers and confers a survival advantage on tumors, leading to poorer outcomes for patients. Recent studies demonstrate how Notch signaling increases tumor cell proliferation and provide evidence that active Notch signaling maintains the cancer stem-cell pool, induces epithelial-mesenchymal transition and promotes chemoresistance. These studies imply that pharmacological inhibition of Notch signaling may refine control of cancer therapy and improve patient survival. Gamma secretase inhibitors (GSIs) are drugs that inhibit Notch signaling and may be successful in controlling cancer cell growth in conjunction with standard chemotherapy, but substantial side effects have hampered their widespread use. Recent efforts have been aimed at the development of antibodies against specific Notch receptors and ligands with the hope of limiting side effects while providing the same therapeutic benefit as GSIs. Together, studies characterizing Notch signaling and modulation have offered hope that refined methods targeting Notch may become powerful tools in anticancer therapeutics. PMID:23585460

  12. Stochastic Regulation of her1/7 Gene Expression Is the Source of Noise in the Zebrafish Somite Clock Counteracted by Notch Signalling

    PubMed Central

    Jenkins, Robert P.; Hanisch, Anja; Soza-Ried, Cristian; Sahai, Erik

    2015-01-01

    The somite segmentation clock is a robust oscillator used to generate regularly-sized segments during early vertebrate embryogenesis. It has been proposed that the clocks of neighbouring cells are synchronised via inter-cellular Notch signalling, in order to overcome the effects of noisy gene expression. When Notch-dependent communication between cells fails, the clocks of individual cells operate erratically and lose synchrony over a period of about 5 to 8 segmentation clock cycles (2–3 hours in the zebrafish). Here, we quantitatively investigate the effects of stochasticity on cell synchrony, using mathematical modelling, to investigate the likely source of such noise. We find that variations in the transcription, translation and degradation rate of key Notch signalling regulators do not explain the in vivo kinetics of desynchronisation. Rather, the analysis predicts that clock desynchronisation, in the absence of Notch signalling, is due to the stochastic dissociation of Her1/7 repressor proteins from the oscillating her1/7 autorepressed target genes. Using in situ hybridisation to visualise sites of active her1 transcription, we measure an average delay of approximately three minutes between the times of activation of the two her1 alleles in a cell. Our model shows that such a delay is sufficient to explain the in vivo rate of clock desynchronisation in Notch pathway mutant embryos and also that Notch-mediated synchronisation is sufficient to overcome this stochastic variation. This suggests that the stochastic nature of repressor/DNA dissociation is the major source of noise in the segmentation clock. PMID:26588097

  13. Notch pathway activation targets AML-initiating cell homeostasis and differentiation

    PubMed Central

    Ntziachristos, Panagiotis; Ndiaye-Lobry, Delphine; Oh, Philmo; Cimmino, Luisa; Zhu, Nan; Araldi, Elisa; Hu, Wenhuo; Freund, Jacquelyn; Abdel-Wahab, Omar; Ibrahim, Sherif; Skokos, Dimitris; Armstrong, Scott A.; Levine, Ross L.; Park, Christopher Y.

    2013-01-01

    Notch signaling pathway activation is known to contribute to the pathogenesis of a spectrum of human malignancies, including T cell leukemia. However, recent studies have implicated the Notch pathway as a tumor suppressor in myeloproliferative neoplasms and several solid tumors. Here we report a novel tumor suppressor role for Notch signaling in acute myeloid leukemia (AML) and demonstrate that Notch pathway activation could represent a therapeutic strategy in this disease. We show that Notch signaling is silenced in human AML samples, as well as in AML-initiating cells in an animal model of the disease. In vivo activation of Notch signaling using genetic Notch gain of function models or in vitro using synthetic Notch ligand induces rapid cell cycle arrest, differentiation, and apoptosis of AML-initiating cells. Moreover, we demonstrate that Notch inactivation cooperates in vivo with loss of the myeloid tumor suppressor Tet2 to induce AML-like disease. These data demonstrate a novel tumor suppressor role for Notch signaling in AML and elucidate the potential therapeutic use of Notch receptor agonists in the treatment of this devastating leukemia. PMID:23359070

  14. Constitutive expression of genes encoding notch receptors and ligands in developing lymphocytes, nTreg cells and dendritic cells in the human thymus.

    PubMed

    Bento-de-Souza, Luciana; Victor, Jefferson R; Bento-de-Souza, Luiz C; Arrais-Santos, Magaly; Rangel-Santos, Andréia C; Pereira-Costa, Érica; Raniero-Fernandes, Elaine; Seixas-Duarte, Maria I; Oliveira-Filho, João B; Silva Duarte, Alberto J

    2016-01-01

    The thymus is the site of T cell maturation. Notch receptors (Notch1-4) and ligands (DLL1-3 and Jagged1-2) constitute one of several pathways involved in this process. Our data revealed differential constitutive expression of Notch genes and ligands in T lymphocytes and thymic dendritic cells (tDCs), suggesting their participation in human thymocyte maturation. nTreg analyses indicated that the Notch components function in parallel to promote maturation in the thymus. PMID:27504259

  15. HES6 promotes prostate cancer aggressiveness independently of Notch signalling

    PubMed Central

    Carvalho, Filipe L F; Marchionni, Luigi; Gupta, Anuj; Kummangal, Basheer A; Schaeffer, Edward M; Ross, Ashley E; Berman, David M

    2015-01-01

    Notch signalling is implicated in the pathogenesis of a variety of cancers, but its role in prostate cancer is poorly understood. However, selected Notch pathway members are overrepresented in high-grade prostate cancers. We comprehensively profiled Notch pathway components in prostate cells and found prostate cancer-specific up-regulation of NOTCH3 and HES6. Their expression was particularly high in androgen responsive lines. Up- and down-regulating Notch in these cells modulated expression of canonical Notch targets, HES1 and HEY1, which could also be induced by androgen. Surprisingly, androgen treatment also suppressed Notch receptor expression, suggesting that androgens can activate Notch target genes in a receptor-independent manner. Using a Notch-sensitive Recombination signal binding protein for immunoglobulin kappa J region (RBPJ) reporter assay, we found that basal levels of Notch signalling were significantly lower in prostate cancer cells compared to benign cells. Accordingly pharmacological Notch pathway blockade did not inhibit cancer cell growth or viability. In contrast to canonical Notch targets, HES6, a HES family member known to antagonize Notch signalling, was not regulated by Notch signalling, but relied instead on androgen levels, both in cultured cells and in human cancer tissues. When engineered into prostate cancer cells, reduced levels of HES6 resulted in reduced cancer cell invasion and clonogenic growth. By molecular profiling, we identified potential roles for HES6 in regulating hedgehog signalling, apoptosis and cell migration. Our results did not reveal any cell-autonomous roles for canonical Notch signalling in prostate cancer. However, the results do implicate HES6 as a promoter of prostate cancer progression. PMID:25864518

  16. Gene expression analysis reveals that Delta/Notch signalling is not involved in onychophoran segmentation.

    PubMed

    Janssen, Ralf; Budd, Graham E

    2016-03-01

    Delta/Notch (Dl/N) signalling is involved in the gene regulatory network underlying the segmentation process in vertebrates and possibly also in annelids and arthropods, leading to the hypothesis that segmentation may have evolved in the last common ancestor of bilaterian animals. Because of seemingly contradicting results within the well-studied arthropods, however, the role and origin of Dl/N signalling in segmentation generally is still unclear. In this study, we investigate core components of Dl/N signalling by means of gene expression analysis in the onychophoran Euperipatoides kanangrensis, a close relative to the arthropods. We find that neither Delta or Notch nor any other investigated components of its signalling pathway are likely to be involved in segment addition in onychophorans. We instead suggest that Dl/N signalling may be involved in posterior elongation, another conserved function of these genes. We suggest further that the posterior elongation network, rather than classic Dl/N signalling, may be in the control of the highly conserved segment polarity gene network and the lower-level pair-rule gene network in onychophorans. Consequently, we believe that the pair-rule gene network and its interaction with Dl/N signalling may have evolved within the arthropod lineage and that Dl/N signalling has thus likely been recruited independently for segment addition in different phyla. PMID:26935716

  17. Gene expression analysis reveals that Delta/Notch signalling is not involved in onychophoran segmentation.

    PubMed

    Janssen, Ralf; Budd, Graham E

    2016-03-01

    Delta/Notch (Dl/N) signalling is involved in the gene regulatory network underlying the segmentation process in vertebrates and possibly also in annelids and arthropods, leading to the hypothesis that segmentation may have evolved in the last common ancestor of bilaterian animals. Because of seemingly contradicting results within the well-studied arthropods, however, the role and origin of Dl/N signalling in segmentation generally is still unclear. In this study, we investigate core components of Dl/N signalling by means of gene expression analysis in the onychophoran Euperipatoides kanangrensis, a close relative to the arthropods. We find that neither Delta or Notch nor any other investigated components of its signalling pathway are likely to be involved in segment addition in onychophorans. We instead suggest that Dl/N signalling may be involved in posterior elongation, another conserved function of these genes. We suggest further that the posterior elongation network, rather than classic Dl/N signalling, may be in the control of the highly conserved segment polarity gene network and the lower-level pair-rule gene network in onychophorans. Consequently, we believe that the pair-rule gene network and its interaction with Dl/N signalling may have evolved within the arthropod lineage and that Dl/N signalling has thus likely been recruited independently for segment addition in different phyla.

  18. Notch3/Jagged1 circuitry reinforces notch signaling and sustains T-ALL.

    PubMed

    Pelullo, Maria; Quaranta, Roberta; Talora, Claudio; Checquolo, Saula; Cialfi, Samantha; Felli, Maria Pia; te Kronnie, Geertruy; Borga, Chiara; Besharat, Zein Mersini; Palermo, Rocco; Di Marcotullio, Lucia; Capobianco, Anthony J; Gulino, Alberto; Screpanti, Isabella; Bellavia, Diana

    2014-12-01

    Deregulated Notch signaling has been extensively linked to T-cell acute lymphoblastic leukemia (T-ALL). Here, we show a direct relationship between Notch3 receptor and Jagged1 ligand in human cell lines and in a mouse model of T-ALL. We provide evidence that Notch-specific ligand Jagged1 is a new Notch3 signaling target gene. This essential event justifies an aberrant Notch3/Jagged1 cis-expression inside the same cell. Moreover, we demonstrate in Notch3-IC-overexpressing T lymphoma cells that Jagged1 undergoes a raft-associated constitutive processing. The proteolytic cleavage allows the Jagged1 intracellular domain to empower Notch signaling activity and to increase the transcriptional activation of Jagged1 itself (autocrine effect). On the other hand, the release of the soluble Jagged1 extracellular domain has a positive impact on activating Notch signaling in adjacent cells (paracrine effect), finally giving rise to a Notch3/Jagged1 auto-sustaining loop that supports the survival, proliferation, and invasion of lymphoma cells and contributes to the development and progression of Notch-dependent T-ALL. These observations are also supported by a study conducted on a cohort of patients in which Jagged1 expression is associated to adverse prognosis. PMID:25499214

  19. Inhibitory Role of Notch1 in Calcific Aortic Valve Disease

    PubMed Central

    Koenig, Sara N.; Nichols, Haley A.; Galindo, Cristi L.; Garner, Harold R.; Merrill, Walter H.; Hinton, Robert B.; Garg, Vidu

    2011-01-01

    Aortic valve calcification is the most common form of valvular heart disease, but the mechanisms of calcific aortic valve disease (CAVD) are unknown. NOTCH1 mutations are associated with aortic valve malformations and adult-onset calcification in families with inherited disease. The Notch signaling pathway is critical for multiple cell differentiation processes, but its role in the development of CAVD is not well understood. The aim of this study was to investigate the molecular changes that occur with inhibition of Notch signaling in the aortic valve. Notch signaling pathway members are expressed in adult aortic valve cusps, and examination of diseased human aortic valves revealed decreased expression of NOTCH1 in areas of calcium deposition. To identify downstream mediators of Notch1, we examined gene expression changes that occur with chemical inhibition of Notch signaling in rat aortic valve interstitial cells (AVICs). We found significant downregulation of Sox9 along with several cartilage-specific genes that were direct targets of the transcription factor, Sox9. Loss of Sox9 expression has been published to be associated with aortic valve calcification. Utilizing an in vitro porcine aortic valve calcification model system, inhibition of Notch activity resulted in accelerated calcification while stimulation of Notch signaling attenuated the calcific process. Finally, the addition of Sox9 was able to prevent the calcification of porcine AVICs that occurs with Notch inhibition. In conclusion, loss of Notch signaling contributes to aortic valve calcification via a Sox9-dependent mechanism. PMID:22110751

  20. Targeting Notch, Hedgehog, and Wnt pathways in cancer stem cells: clinical update

    PubMed Central

    Miele, Lucio; Harris, Pamela Jo; Jeong, Woondong; Bando, Hideaki; Kahn, Michael; Yang, Sherry X.

    2015-01-01

    During the past decade, cancer stem cells (CSCs) have been increasingly identified in many malignancies. Although the origin and plasticity of these cells remain controversial, tumour heterogeneity and the presence of small populations of cells with stem-like characteristics is established in most malignancies. CSCs display many features of embryonic or tissue stem cells, and typically demonstrate persistent activation of one or more highly conserved signal transduction pathways involved in development and tissue homeostasis, including the Notch, Hedgehog (HH), and Wnt pathways. CSCs generally have slow growth rates and are resistant to chemotherapy and/or radiotherapy. Thus, new treatment strategies targeting these pathways to control stem-cell replication, survival and differentiation are under development. Herein, we provide an update on the latest advances in the clinical development of such approaches, and discuss strategies for overcoming CSC-associated primary or acquired resistance to cancer treatment. Given the crosstalk between the different embryonic developmental signalling pathways, as well as other pathways, designing clinical trials that target CSCs with rational combinations of agents to inhibit possible compensatory escape mechanisms could be of particular importance. We also share our views on the future directions for targeting CSCs to advance the clinical development of these classes of agents. PMID:25850553

  1. Simultaneous targeted activation of Notch1 and Vhl-disruption in the kidney proximal epithelial tubular cells in mice

    PubMed Central

    Johansson, Elinn; Rönö, Birgitte; Johansson, Martin; Lindgren, David; Möller, Christina; Axelson, Håkan; Smith, Emma M. K.

    2016-01-01

    Clear cell renal cell carcinoma (ccRCC) is the most common subtype of kidney cancer, representing approximately 75% of all renal neoplasms. ccRCC is known to be strongly associated with silencing of the von Hippel Lindau (VHL) tumor suppressor gene, yet VHL deficiency alone does not seem to be sufficient to drive the oncogenic transformation of normal renal epithelium and induce renal tumorigenesis. We, and others, have previously suggested that constitutive activation of the Notch signaling pathway, alongside with VHL loss, contribute to the oncogenic features of ccRCC. Here we report a prevailing hyperactivation of the Notch1 receptor in human ccRCC relative to the healthy counterpart. To explore the consequences of the elevated Notch1 signaling observed in ccRCC patient material, we made use of a conditional mouse model based on concurrent ectopic expression of constitutively active Notch1 (NICD1) and deletion of the Vhl gene. Histological examination of the kidneys of the conditional mice demonstrate the existence of nests of dysplastic cells with a clear cytoplasm as a consequence of lipid accumulation, thus displaying a one important hallmark of human ccRCC. PMID:27491826

  2. Simultaneous targeted activation of Notch1 and Vhl-disruption in the kidney proximal epithelial tubular cells in mice.

    PubMed

    Johansson, Elinn; Rönö, Birgitte; Johansson, Martin; Lindgren, David; Möller, Christina; Axelson, Håkan; Smith, Emma M K

    2016-01-01

    Clear cell renal cell carcinoma (ccRCC) is the most common subtype of kidney cancer, representing approximately 75% of all renal neoplasms. ccRCC is known to be strongly associated with silencing of the von Hippel Lindau (VHL) tumor suppressor gene, yet VHL deficiency alone does not seem to be sufficient to drive the oncogenic transformation of normal renal epithelium and induce renal tumorigenesis. We, and others, have previously suggested that constitutive activation of the Notch signaling pathway, alongside with VHL loss, contribute to the oncogenic features of ccRCC. Here we report a prevailing hyperactivation of the Notch1 receptor in human ccRCC relative to the healthy counterpart. To explore the consequences of the elevated Notch1 signaling observed in ccRCC patient material, we made use of a conditional mouse model based on concurrent ectopic expression of constitutively active Notch1 (NICD1) and deletion of the Vhl gene. Histological examination of the kidneys of the conditional mice demonstrate the existence of nests of dysplastic cells with a clear cytoplasm as a consequence of lipid accumulation, thus displaying a one important hallmark of human ccRCC. PMID:27491826

  3. Notch Signaling Components

    PubMed Central

    Liu, Zhi-Yan; Wu, Tao; Li, Qing; Wang, Min-Cong; Jing, Li; Ruan, Zhi-Ping; Yao, Yu; Nan, Ke-Jun; Guo, Hui

    2016-01-01

    Abstract Non-small-cell lung cancer (NSCLC) is a lethal and aggressive malignancy. Currently, the identities of prognostic and predictive makers of NSCLC have not been fully established. Dysregulated Notch signaling has been implicated in many human malignancies, including NSCLC. However, the prognostic value of measuring Notch signaling and the utility of developing Notch-targeted therapies in NSCLC remain inconclusive. The present study investigated the association of individual Notch receptor and ligand levels with lung adenocarcinoma (ADC) and squamous cell carcinoma (SCC) prognosis using the Kaplan-Meier plotte database. This online database encompasses 2437 lung cancer samples. Hazard ratios with 95% confidence intervals were calculated. The results showed that higher Notch1, Notch2, JAG1, and DLL1 mRNA expression predicted better overall survival (OS) in lung ADC, but showed no significance in SCC patients. Elevated Notch3, JAG2, and DLL3 mRNA expression was associated with poor OS of ADC patients, but not in SCC patients. There was no association between Notch4 and OS in either lung ADC or SCC patients. In conclusion, the set of Notch1, Notch2, JAG1, DLL1 and that of Notch3, JAG2, DLL3 played opposing prognostic roles in lung ADC patients. Neither set of Notch receptors and ligands was indicative of lung SCC prognosis. Notch signaling could serve as promising marker to predict outcomes in lung ADC patients. The distinct features of lung cancer subtypes and Notch components should be considered when developing future Notch-targeted therapies. PMID:27196489

  4. Notch1, Notch2, and Epstein-Barr virus-encoded nuclear antigen 2 signaling differentially affects proliferation and survival of Epstein-Barr virus-infected B cells.

    PubMed

    Kohlhof, Hella; Hampel, Franziska; Hoffmann, Reinhard; Burtscher, Helmut; Weidle, Ulrich H; Hölzel, Michael; Eick, Dirk; Zimber-Strobl, Ursula; Strobl, Lothar J

    2009-05-28

    The canonical mode of transcriptional activation by both the Epstein-Barr viral protein, Epstein-Barr virus-encoded nuclear antigen 2 (EBNA2), and an activated Notch receptor (Notch-IC) requires their recruitment to RBPJ, suggesting that EBNA2 uses the Notch pathway to achieve B-cell immortalization. To gain further insight into the biologic equivalence between Notch-IC and EBNA2, we performed a genome-wide expression analysis, revealing that Notch-IC and EBNA2 exhibit profound differences in the regulation of target genes. Whereas Notch-IC is more potent in regulating genes associated with differentiation and development, EBNA2 is more potent in inducing viral and cellular genes involved in proliferation, survival, and chemotaxis. Because both EBNA2 and Notch-IC induced the expression of cell cycle-associated genes, we analyzed whether Notch1-IC or Notch2-IC can replace EBNA2 in B-cell immortalization. Although Notch-IC could drive quiescent B cells into the cell cycle, B-cell immortalization was not maintained, partially due to an increased apoptosis rate in Notch-IC-expressing cells. Expression analysis revealed that both EBNA2 and Notch-IC induced the expression of proapoptotic genes, but only in EBNA2-expressing cells were antiapoptotic genes strongly up-regulated. These findings suggest that Notch signaling in B cells and B-cell lymphomas is only compatible with proliferation if pathways leading to antiapototic signals are active. PMID:19339697

  5. FBXW7 influences murine intestinal homeostasis and cancer, targeting Notch, Jun, and DEK for degradation

    PubMed Central

    Babaei-Jadidi, Roya; Li, Ningning; Saadeddin, Anas; Spencer-Dene, Bradley; Jandke, Anett; Muhammad, Belal; Ibrahim, ElSayed E.; Muraleedharan, Ranjithmenon; Abuzinadah, Mohammed; Davis, Hayley; Lewis, Annabelle; Watson, Susan; Behrens, Axel; Tomlinson, Ian

    2011-01-01

    The Fbxw7 (F-box/WD repeat–containing protein 7; also called CDC4, Sel10, Ago, and Fbw7) component of the SCF (Skp1/Cullin/F-box protein) E3 ubiquitin ligase complex acts as a tumor suppressor in several tissues and targets multiple transcriptional activators and protooncogenes for ubiquitin-mediated degradation. To understand Fbxw7 function in the murine intestine, in this study, we specifically deleted Fbxw7 in the murine gut using Villin-Cre (Fbxw7ΔG). In wild-type mice, loss of Fbxw7 in the gut altered homeostasis of the intestinal epithelium, resulted in elevated Notch and c-Jun expression, and induced development of adenomas at 9–10 mo of age. In the context of APC (adenomatous polyposis coli) deficiency (ApcMin/+ mice), loss of Fbxw7 accelerated intestinal tumorigenesis and death and promoted accumulation of β-catenin in adenomas at late but not early time points. At early time points, Fbxw7 mutant tumors showed accumulation of the DEK protooncogene. DEK expression promoted cell division and altered splicing of tropomyosin (TPM) RNA, which may also influence cell proliferation. DEK accumulation and altered TPM RNA splicing were also detected in FBXW7 mutant human colorectal tumor tissues. Given their reduced lifespan and increased incidence of intestinal tumors, ApcMin/+Fbxw7ΔG mice may be used for testing carcinogenicity and drug screening. PMID:21282377

  6. Targeting Homologous Recombination in Notch-Driven C. elegans Stem Cell and Human Tumors

    PubMed Central

    Deng, Xinzhu; Michaelson, David; Tchieu, Jason; Cheng, Jin; Rothenstein, Diana; Feldman, Regina; Lee, Sang-gyu; Fuller, John; Haimovitz-Friedman, Adriana; Studer, Lorenz; Powell, Simon; Fuks, Zvi; Hubbard, E. Jane Albert; Kolesnick, Richard

    2015-01-01

    Mammalian NOTCH1-4 receptors are all associated with human malignancy, although exact roles remain enigmatic. Here we employ glp-1(ar202), a temperature-sensitive gain-of-function C. elegans NOTCH mutant, to delineate NOTCH-driven tumor responses to radiotherapy. At ≤20°C, glp-1(ar202) is wild-type, whereas at 25°C it forms a germline stem cell⁄progenitor cell tumor reminiscent of human cancer. We identify a NOTCH tumor phenotype in which all tumor cells traffic rapidly to G2⁄M post-irradiation, attempt to repair DNA strand breaks exclusively via homology-driven repair, and when this fails die by mitotic death. Homology-driven repair inactivation is dramatically radiosensitizing. We show that these concepts translate directly to human cancer models. PMID:26120834

  7. A novel Monoclonal Antibody against Notch1 Targets Leukemia-associated Mutant Notch1 and Depletes Therapy Resistant Cancer Stem Cells in Solid Tumors

    PubMed Central

    Sharma, Ankur; Gadkari, Rupali A; Ramakanth, Satthenapalli V; Padmanabhan, Krishnanand; Madhumathi, Davanam S; Devi, Lakshmi; Appaji, Lingappa; Aster, Jon C; Rangarajan, Annapoorni; Dighe, Rajan R

    2015-01-01

    Higher Notch signaling is known to be associated with hematological and solid cancers. We developed a potential immunotherapeutic monoclonal antibody (MAb) specific for the Negative Regulatory Region of Notch1 (NRR). The MAb604.107 exhibited higher affinity for the “Gain-of-function” mutants of Notch1 NRR associated with T Acute lymphoblastic Leukemia (T-ALL). Modeling of the mutant NRR with 12 amino-acid insertion demonstrated “opening” resulting in exposure of the S2-cleavage site leading to activated Notch1 signaling. The MAb, at low concentrations (1–2 μg/ml), inhibited elevated ligand-independent Notch1 signaling of NRR mutants, augmented effect of Thapsigargin, an inhibitor of mutant Notch1, but had no effect on the wild-type Notch1. The antibody decreased proliferation of the primary T-ALL cells and depleted leukemia initiating CD34/CD44 high population. At relatively high concentrations, (10–20 μg/ml), the MAb affected Notch1 signaling in the breast and colon cancer cell lines. The Notch-high cells sorted from solid-tumor cell lines exhibited characteristics of cancer stem cells, which were inhibited by the MAb. The antibody also increased the sensitivity to Doxorubucinirubicin. Further, the MAb impeded the growth of xenografts from breast and colon cancer cells potentiated regression of the tumors along with Doxorubucin. Thus, this antibody is potential immunotherapeutic tool for different cancers. PMID:26046801

  8. The Selector Gene apterous and Notch Are Required to Locally Increase Mechanical Cell Bond Tension at the Drosophila Dorsoventral Compartment Boundary

    PubMed Central

    Michel, Marcus; Aliee, Maryam; Rudolf, Katrin; Bialas, Lisa; Jülicher, Frank; Dahmann, Christian

    2016-01-01

    The separation of cells with distinct fates and functions is important for tissue and organ formation during animal development. Regions of different fates within tissues are often separated from another along straight boundaries. These compartment boundaries play a crucial role in tissue patterning and growth by stably positioning organizers. In Drosophila, the wing imaginal disc is subdivided into a dorsal and a ventral compartment. Cells of the dorsal, but not ventral, compartment express the selector gene apterous. Apterous expression sets in motion a gene regulatory cascade that leads to the activation of Notch signaling in a few cell rows on either side of the dorsoventral compartment boundary. Both Notch and apterous mutant clones disturb the separation of dorsal and ventral cells. Maintenance of the straight shape of the dorsoventral boundary involves a local increase in mechanical tension at cell bonds along the boundary. The mechanisms by which cell bond tension is locally increased however remain unknown. Here we use a combination of laser ablation of cell bonds, quantitative image analysis, and genetic mutants to show that Notch and Apterous are required to increase cell bond tension along the dorsoventral compartment boundary. Moreover, clonal expression of the Apterous target gene capricious results in cell separation and increased cell bond tension at the clone borders. Finally, using a vertex model to simulate tissue growth, we find that an increase in cell bond tension at the borders of cell clones, but not throughout the cell clone, can lead to cell separation. We conclude that Apterous and Notch maintain the characteristic straight shape of the dorsoventral compartment boundary by locally increasing cell bond tension. PMID:27552097

  9. The Selector Gene apterous and Notch Are Required to Locally Increase Mechanical Cell Bond Tension at the Drosophila Dorsoventral Compartment Boundary.

    PubMed

    Michel, Marcus; Aliee, Maryam; Rudolf, Katrin; Bialas, Lisa; Jülicher, Frank; Dahmann, Christian

    2016-01-01

    The separation of cells with distinct fates and functions is important for tissue and organ formation during animal development. Regions of different fates within tissues are often separated from another along straight boundaries. These compartment boundaries play a crucial role in tissue patterning and growth by stably positioning organizers. In Drosophila, the wing imaginal disc is subdivided into a dorsal and a ventral compartment. Cells of the dorsal, but not ventral, compartment express the selector gene apterous. Apterous expression sets in motion a gene regulatory cascade that leads to the activation of Notch signaling in a few cell rows on either side of the dorsoventral compartment boundary. Both Notch and apterous mutant clones disturb the separation of dorsal and ventral cells. Maintenance of the straight shape of the dorsoventral boundary involves a local increase in mechanical tension at cell bonds along the boundary. The mechanisms by which cell bond tension is locally increased however remain unknown. Here we use a combination of laser ablation of cell bonds, quantitative image analysis, and genetic mutants to show that Notch and Apterous are required to increase cell bond tension along the dorsoventral compartment boundary. Moreover, clonal expression of the Apterous target gene capricious results in cell separation and increased cell bond tension at the clone borders. Finally, using a vertex model to simulate tissue growth, we find that an increase in cell bond tension at the borders of cell clones, but not throughout the cell clone, can lead to cell separation. We conclude that Apterous and Notch maintain the characteristic straight shape of the dorsoventral compartment boundary by locally increasing cell bond tension. PMID:27552097

  10. The Selector Gene apterous and Notch Are Required to Locally Increase Mechanical Cell Bond Tension at the Drosophila Dorsoventral Compartment Boundary.

    PubMed

    Michel, Marcus; Aliee, Maryam; Rudolf, Katrin; Bialas, Lisa; Jülicher, Frank; Dahmann, Christian

    2016-01-01

    The separation of cells with distinct fates and functions is important for tissue and organ formation during animal development. Regions of different fates within tissues are often separated from another along straight boundaries. These compartment boundaries play a crucial role in tissue patterning and growth by stably positioning organizers. In Drosophila, the wing imaginal disc is subdivided into a dorsal and a ventral compartment. Cells of the dorsal, but not ventral, compartment express the selector gene apterous. Apterous expression sets in motion a gene regulatory cascade that leads to the activation of Notch signaling in a few cell rows on either side of the dorsoventral compartment boundary. Both Notch and apterous mutant clones disturb the separation of dorsal and ventral cells. Maintenance of the straight shape of the dorsoventral boundary involves a local increase in mechanical tension at cell bonds along the boundary. The mechanisms by which cell bond tension is locally increased however remain unknown. Here we use a combination of laser ablation of cell bonds, quantitative image analysis, and genetic mutants to show that Notch and Apterous are required to increase cell bond tension along the dorsoventral compartment boundary. Moreover, clonal expression of the Apterous target gene capricious results in cell separation and increased cell bond tension at the clone borders. Finally, using a vertex model to simulate tissue growth, we find that an increase in cell bond tension at the borders of cell clones, but not throughout the cell clone, can lead to cell separation. We conclude that Apterous and Notch maintain the characteristic straight shape of the dorsoventral compartment boundary by locally increasing cell bond tension.

  11. RIPping notch apart: a new role for endocytosis in signal transduction?

    PubMed

    Krämer, H

    2000-04-25

    Notch proteins are receptors that are important in mediating several developmental processes. Notch receptors are activated upon binding transmembrane ligands, the DSL proteins. Notch is cleaved at several sites and activation of Notch leads to the cleavage of the intracellular domain, which then is translocated to the nucleus and regulates the transcription of target genes. Krämer discusses how binding of Notch to the DSL ligand, Delta, leads to cleavage and trans-endocytosis of the Notch extracellular domain into the Delta-expressing cell. This trans-endocytosis event contributes to the cleavage and release of the active Notch intracellular domain. The Perspective is accompanied by a movie illustrating the trans-endocytosis of Notch.

  12. Characterization of Notch Signaling During Osteogenic Differentiation in Human Osteosarcoma Cell Line MG63.

    PubMed

    Ongaro, Alessia; Pellati, Agnese; Bagheri, Leila; Rizzo, Paola; Caliceti, Cristiana; Massari, Leo; De Mattei, Monica

    2016-12-01

    Osteogenic differentiation is a multi-step process controlled by a complex molecular framework. Notch is an evolutionarily conserved intercellular signaling pathway playing a prominent role in cell fate and differentiation, although the mechanisms by which this pathway regulates osteogenesis remain controversial. This study aimed to investigate, in vitro, the involvement of Notch pathway during all the developmental stages of osteogenic differentiation in human osteosarcoma cell line MG63. Cells were cultured in basal condition (control) and in osteoinductive medium (OM). Notch inhibitors were also added in OM to block Notch pathway. During osteogenic differentiation, early (alkaline phosphatase activity and collagen type I) and late osteogenic markers (osteocalcin levels and matrix mineralization), as well as the gene expression of the main osteogenic transcription factors (Runx2, Osterix, and Dlx5) increased. Time dependent changes in the expression of specific Notch receptors were identified in OM versus control with a significant reduction in the expression of Notch1 and Notch3 receptors in the early phase of differentiation, and an increase of Notch2 and Notch4 receptors in the late phase. Among Notch nuclear target genes, Hey1 expression was significantly higher in OM than control, while Hes5 expression decreased. Osteogenic markers were reduced and Hey1 was significantly inhibited by Notch inhibitors, suggesting a role for Notch through the canonical pathway. In conclusion, Notch pathway might be involved with a dual role in osteogenesis of MG63, through the activation of Notch2, Notch4, and Hey1, inducing osteoblast differentiation and the depression of Notch1, Notch3, and Hes5, maintaining an undifferentiated status. J. Cell. Physiol. 231: 2652-2663, 2016. © 2016 Wiley Periodicals, Inc. PMID:26946465

  13. The MSX1 homeobox transcription factor is a downstream target of PHOX2B and activates the Delta-Notch pathway in neuroblastoma

    SciTech Connect

    Revet, Ingrid; Huizenga, Gerda; Chan, Alvin; Koster, Jan; Volckmann, Richard; Sluis, Peter van; Ora, Ingrid; Versteeg, Rogier; Geerts, Dirk

    2008-02-15

    Neuroblastoma is an embryonal tumour of the peripheral sympathetic nervous system (SNS). One of the master regulator genes for peripheral SNS differentiation, the homeobox transcription factor PHOX2B, is mutated in familiar and sporadic neuroblastomas. Here we report that inducible expression of PHOX2B in the neuroblastoma cell line SJNB-8 down-regulates MSX1, a homeobox gene important for embryonic neural crest development. Inducible expression of MSX1 in SJNB-8 caused inhibition of both cell proliferation and colony formation in soft agar. Affymetrix micro-array and Northern blot analysis demonstrated that MSX1 strongly up-regulated the Delta-Notch pathway genes DLK1, NOTCH3, and HEY1. In addition, the proneural gene NEUROD1 was down-regulated. Western blot analysis showed that MSX1 induction caused cleavage of the NOTCH3 protein to its activated form, further confirming activation of the Delta-Notch pathway. These experiments describe for the first time regulation of the Delta-Notch pathway by MSX1, and connect these genes to the PHOX2B oncogene, indicative of a role in neuroblastoma biology. Affymetrix micro-array analysis of a neuroblastic tumour series consisting of neuroblastomas and the more benign ganglioneuromas showed that MSX1, NOTCH3 and HEY1 are more highly expressed in ganglioneuromas. This suggests a block in differentiation of these tumours at distinct developmental stages or lineages.

  14. notch3 is essential for oligodendrocyte development and vascular integrity in zebrafish

    PubMed Central

    Zaucker, Andreas; Mercurio, Sara; Sternheim, Nitzan; Talbot, William S.; Marlow, Florence L.

    2013-01-01

    SUMMARY Mutations in the human NOTCH3 gene cause CADASIL syndrome (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy). CADASIL is an inherited small vessel disease characterized by diverse clinical manifestations including vasculopathy, neurodegeneration and dementia. Here we report two mutations in the zebrafish notch3 gene, one identified in a previous screen for mutations with reduced expression of myelin basic protein (mbp) and another caused by a retroviral insertion. Reduced mbp expression in notch3 mutant embryos is associated with fewer oligodendrocyte precursor cells (OPCs). Despite an early neurogenic phenotype, mbp expression recovered at later developmental stages and some notch3 homozygous mutants survived to adulthood. These mutants, as well as adult zebrafish carrying both mutant alleles together, displayed a striking stress-associated accumulation of blood in the head and fins. Histological analysis of mutant vessels revealed vasculopathy, including: an enlargement (dilation) of vessels in the telencephalon and fin, disorganization of the normal stereotyped arrangement of vessels in the fin, and an apparent loss of arterial morphological structure. Expression of hey1, a well-known transcriptional target of Notch signaling, was greatly reduced in notch3 mutant fins, suggesting that Notch3 acts via a canonical Notch signaling pathway to promote normal vessel structure. Ultrastructural analysis confirmed the presence of dilated vessels in notch3 mutant fins and revealed that the vessel walls of presumed arteries showed signs of deterioration. Gaps in the arterial wall and the presence of blood cells outside of vessels in mutants indicated that compromised vessel structure led to hemorrhage. In notch3 heterozygotes, we found elevated expression of both notch3 itself and target genes, indicating that specific alterations in gene expression due to partial loss of Notch3 function might contribute to the

  15. Gene targeting with retroviral vectors

    SciTech Connect

    Ellis, J.; Bernstein, A. )

    1989-04-01

    The authors have designed and constructed integration-defective retroviral vectors to explore their potential for gene targeting in mammalian cells. Two nonoverlapping deletion mutants of the bacterial neomycin resistance (neo) gene were used to detect homologous recombination events between viral and chromosomal sequences. Stable neo gene correction events were selected at a frequency of approximately 1 G418/sup r/ cell per 3 x 10/sup 6/ infected cells. Analysis of the functional neo gene in independent targeted cell clones indicated that unintegrated retroviral linear DNA recombined with the target by gene conversion for variable distances into regions of nonhomology. In addition, transient neo gene correction events which were associated with the complete loss of the chromosomal target sequences were observed. These results demonstrated that retroviral vectors can recombine with homologous chromosomal sequences in rodent and human cells.

  16. Notch Signaling in Pancreatic Development

    PubMed Central

    Li, Xu-Yan; Zhai, Wen-Jun; Teng, Chun-Bo

    2015-01-01

    The Notch signaling pathway plays a significant role in embryonic cell fate determination and adult tissue homeostasis. Various studies have demonstrated the deep involvement of Notch signaling in the development of the pancreas and the lateral inhibition of Notch signaling in pancreatic progenitor differentiation and maintenance. The targeted inactivation of the Notch pathway components promotes premature differentiation of the endocrine pancreas. However, there is still the contrary opinion that Notch signaling specifies the endocrine lineage. Here, we review the current knowledge of the Notch signaling pathway in pancreatic development and its crosstalk with the Wingless and INT-1 (Wnt) and fibroblast growth factor (FGF) pathways. PMID:26729103

  17. Receptor tyrosine phosphatase psi is required for Delta/Notch signalling and cyclic gene expression in the presomitic mesoderm.

    PubMed

    Aerne, Birgit; Ish-Horowicz, David

    2004-07-01

    Segmentation in vertebrate embryos is controlled by a biochemical oscillator ('segmentation clock') intrinsic to the cells in the unsegmented presomitic mesoderm, and is manifested in cyclic transcription of genes involved in establishing somite polarity and boundaries. We show that the receptor protein tyrosine phosphatase psi (RPTPpsi) gene is essential for normal functioning of the somitogenesis clock in zebrafish. We show that reduction of RPTPpsi activity using morpholino antisense oligonucleotides results in severe disruption of the segmental pattern of the embryo, and loss of cyclic gene expression in the presomitic mesoderm. Analysis of cyclic genes in RPTPpsi morphant embryos indicates an important requirement for RPTPpsi in the control of the somitogenesis clock upstream of or in parallel with Delta/Notch signalling. Impairing RPTPpsi activity also interferes with convergent extension during gastrulation. We discuss this dual requirement for RPTPpsi in terms of potential functions in Notch and Wnt signalling. PMID:15226256

  18. Antagonism of notch signaling activity by members of a novel protein family encoded by the bearded and enhancer of split gene complexes.

    PubMed

    Lai, E C; Bodner, R; Kavaler, J; Freschi, G; Posakony, J W

    2000-01-01

    Cell-cell signaling through the Notch receptor is a principal mechanism underlying cell fate specification in a variety of developmental processes in metazoans, such as neurogenesis. In this report we describe our investigation of seven members of a novel gene family in Drosophila with important connections to Notch signaling. These genes all encode small proteins containing predicted basic amphipathic (&agr;)-helical domains in their amino-terminal regions, as described originally for Bearded; accordingly, we refer to them as Bearded family genes. Five members of the Bearded family are located in a newly discovered gene complex, the Bearded Complex; two others reside in the previously identified Enhancer of split Complex. All members of this family contain, in their proximal upstream regions, at least one high-affinity binding site for the Notch-activated transcription factor Suppressor of Hairless, suggesting that all are directly regulated by the Notch pathway. Consistent with this, we show that Bearded family genes are expressed in a variety of territories in imaginal tissue that correspond to sites of active Notch signaling. We demonstrate that overexpression of any family member antagonizes the activity of the Notch pathway in multiple cell fate decisions during adult sensory organ development. These results suggest that Bearded family genes encode a novel class of effectors or modulators of Notch signaling.

  19. Short hairpin RNA targeting Notch2 inhibits U87 human glioma cell proliferation by inducing cell cycle arrest and apoptosis in vitro and in vivo

    PubMed Central

    LI, XUEZHEN; HE, XIN; TIAN, WEI; WANG, JIANZHEN

    2014-01-01

    Notch signaling has been reported to be oncogenic or tumor suppressive, depending on the tissue context. To investigate the effects of Notch2 knockdown on U87 human glioma cell proliferation in vitro and in vivo, and the associated mechanisms, U87 cells were stably transfected with p green fluorescent protein (GFP)-V-RS Notch2 short hairpin (sh) RNA plasmid and pGFP-V-RS scramble-shRNA plasmid. The former was referred to as the Notch2-shRNA group and the latter as the negative-shRNA group. mRNA and protein expression, cell proliferation, cell cycle and apoptosis were measured by reverse transcription-polymerase chain reaction, western blot analysis, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide analysis and flow cytometry using propidium iodide, respectively. Tumor volume, tumor weight and cumulative survival rate were determined in a nude mouse xenograft tumor model. Notch2 mRNA and protein expression in the Notch2-shRNA group were reduced by 87.6 and 94.5% compared with the negative-shRNA group (P<0.001). Notch2 knockdown significantly inhibited U87 cell proliferation after three days of culture (P<0.05). Notch2 silencing induced cell cycle arrest at G0/G1 phase by upregulation of p21 protein expression and downregulation of mini chromosome maintenance complex 2 and cyclin-D1 protein expression. Furthermore, knockdown of Notch2 also induced U87 cell apoptosis. On day 50 after inoculation, tumor weight in the Notch2-shRNA group was significantly lower than that in the negative-shRNA group (0.55±0.10 vs. 1.23±0.52 g; P<0.01). The cumulative survival rate was significantly longer in the Notch2-shRNA group compared with the negative-shRNA group (log rank test P=0.01). In conclusion, Notch2 silencing inhibited U87 glioma cell proliferation by inducing cell cycle arrest and apoptosis in vitro and in vivo. Thus, Notch2 may be a key therapeutic target for the treatment of glioma. PMID:25323114

  20. The Small Molecule IMR-1 Inhibits the Notch Transcriptional Activation Complex to Suppress Tumorigenesis.

    PubMed

    Astudillo, Luisana; Da Silva, Thiago G; Wang, Zhiqiang; Han, Xiaoqing; Jin, Ke; VanWye, Jeffrey; Zhu, Xiaoxia; Weaver, Kelly; Oashi, Taiji; Lopes, Pedro E M; Orton, Darren; Neitzel, Leif R; Lee, Ethan; Landgraf, Ralf; Robbins, David J; MacKerell, Alexander D; Capobianco, Anthony J

    2016-06-15

    In many cancers, aberrant Notch activity has been demonstrated to play a role in the initiation and maintenance of the neoplastic phenotype and in cancer stem cells, which may allude to its additional involvement in metastasis and resistance to therapy. Therefore, Notch is an exceedingly attractive therapeutic target in cancer, but the full range of potential targets within the pathway has been underexplored. To date, there are no small-molecule inhibitors that directly target the intracellular Notch pathway or the assembly of the transcriptional activation complex. Here, we describe an in vitro assay that quantitatively measures the assembly of the Notch transcriptional complex on DNA. Integrating this approach with computer-aided drug design, we explored potential ligand-binding sites and screened for compounds that could disrupt the assembly of the Notch transcriptional activation complex. We identified a small-molecule inhibitor, termed Inhibitor of Mastermind Recruitment-1 (IMR-1), that disrupted the recruitment of Mastermind-like 1 to the Notch transcriptional activation complex on chromatin, thereby attenuating Notch target gene transcription. Furthermore, IMR-1 inhibited the growth of Notch-dependent cell lines and significantly abrogated the growth of patient-derived tumor xenografts. Taken together, our findings suggest that a novel class of Notch inhibitors targeting the transcriptional activation complex may represent a new paradigm for Notch-based anticancer therapeutics, warranting further preclinical characterization. Cancer Res; 76(12); 3593-603. ©2016 AACR. PMID:27197169

  1. Activation of Notch1 signaling is required for β-catenin–mediated human primary melanoma progression

    PubMed Central

    Balint, Klara; Xiao, Min; Pinnix, Chelsea C.; Soma, Akinobu; Veres, Imre; Juhasz, Istvan; Brown, Eric J.; Capobianco, Anthony J.; Herlyn, Meenhard; Liu, Zhao-Jun

    2005-01-01

    Notch is a highly conserved transmembrane receptor that determines cell fate. Notch signaling denotes cleavage of the Notch intracellular domain, its translocation to the nucleus, and subsequent activation of target gene transcription. Involvement of Notch signaling in several cancers is well known, but its role in melanoma remains poorly characterized. Here we show that the Notch1 pathway is activated in human melanoma. Blocking Notch signaling suppressed whereas constitutive activation of the Notch1 pathway enhanced primary melanoma cell growth both in vitro and in vivo yet had little effect on metastatic melanoma cells. Activation of Notch1 signaling enabled primary melanoma cells to gain metastatic capability. Furthermore, the oncogenic effect of Notch1 on primary melanoma cells was mediated by β-catenin, which was upregulated following Notch1 activation. Inhibiting β-catenin expression reversed Notch1-enhanced tumor growth and metastasis. Our data therefore suggest a β-catenin–dependent, stage-specific role for Notch1 signaling in promoting the progression of primary melanoma. PMID:16239965

  2. Notch signaling: its roles and therapeutic potential in hematological malignancies

    PubMed Central

    Gu, Yisu

    2016-01-01

    Notch is a highly conserved signaling system that allows neighboring cells to communicate, thereby controlling their differentiation, proliferation and apoptosis, with the outcome of its activation being highly dependent on signal strength and cell type. As such, there is growing evidence that disturbances in physiological Notch signaling contribute to cancer development and growth through various mechanisms. Notch was first reported to contribute to tumorigenesis in the early 90s, through identification of the involvement of the Notch1 gene in the chromosomal translocation t(7;9)(q34;q34.3), found in a small subset of T-cell acute lymphoblastic leukemia. Since then, Notch mutations and aberrant Notch signaling have been reported in numerous other precursor and mature hematological malignancies, of both myeloid and lymphoid origin, as well as many epithelial tumor types. Of note, Notch has been reported to have both oncogenic and tumor suppressor roles, dependent on the cancer cell type. In this review, we will first give a general description of the Notch signaling pathway, and its physiologic role in hematopoiesis. Next, we will review the role of aberrant Notch signaling in several hematological malignancies. Finally, we will discuss current and potential future therapeutic approaches targeting this pathway. PMID:26934331

  3. The conserved clusterin gene is expressed in the developing choroid plexus under the regulation of notch but not IGF signaling in zebrafish.

    PubMed

    Jiao, Shuang; Dai, Wei; Lu, Ling; Liu, Yunzhang; Zhou, Jianfeng; Li, Yun; Korzh, Vladimir; Duan, Cunming

    2011-05-01

    Recent genome-wide association studies have implicated the clusterin gene in the etiology of Alzheimer's disease. The expression and function of clusterin in the developing brain, however, is poorly understood. In this study, we have characterized the zebrafish clusterin gene and determined its structural conservation, developmental expression, and physiological regulation. The structure of the zebrafish clusterin gene and protein is similar to its human orthologue. Biochemical assays show that zebrafish Clusterin is a secreted protein that cannot bind IGFs. In adult zebrafish, clusterin mRNA is detected in many tissues. In early development, clusterin mRNA becomes detectable at 12 h postfertilization, and its levels gradually increase thereafter. In situ hybridization analysis indicates that clusterin mRNA is specifically expressed in the developing diencephalic and myelencephalic choroid plexus. Among various stresses tested, heat shock, but not hypoxic or ionic stresses, increases the levels of clusterin mRNA. Inhibition of the IGF-I receptor-mediated signaling or overexpression of IGF ligands did not change clusterin mRNA levels. In comparison, inhibition or targeted knockdown of Notch signaling significantly increased clusterin mRNA expression in choroid plexus. These results suggest that clusterin is a marker of choroid plexus in zebrafish, and its expression in the developing choroid plexus is under the regulation of Notch but not IGF signaling.

  4. Gene Targeting in Neuroendocrinology.

    PubMed

    Candlish, Michael; De Angelis, Roberto; Götz, Viktoria; Boehm, Ulrich

    2015-09-20

    Research in neuroendocrinology faces particular challenges due to the complex interactions between cells in the hypothalamus, in the pituitary gland and in peripheral tissues. Within the hypothalamus alone, attempting to target a specific neuronal cell type can be problematic due to the heterogeneous nature and level of cellular diversity of hypothalamic nuclei. Because of the inherent complexity of the reproductive axis, the use of animal models and in vivo experiments are often a prerequisite in reproductive neuroendocrinology. The advent of targeted genetic modifications, particularly in mice, has opened new avenues of neuroendocrine research. Within this review, we evaluate various mouse models used in reproductive neuroendocrinology and discuss the different approaches to generate genetically modified mice, along with their inherent advantages and disadvantages. We also discuss a variety of versatile genetic tools with a focus on their potential use in reproductive neuroendocrinology.

  5. Differential control of Notch1 gene transcription by Klf4 and Sp3 transcription factors in normal versus cancer-derived keratinocytes.

    PubMed

    Lambertini, Chiara; Pantano, Serafino; Dotto, G Paolo

    2010-04-28

    In specific cell types like keratinocytes, Notch signaling plays an important pro-differentiation and tumor suppressing function, with down-modulation of the Notch1 gene being associated with cancer development. Besides being controlled by p53, little else is known on regulation of Notch1 gene expression in this context. We report here that transcription of this gene is driven by a TATA-less "sharp peak" promoter and that the minimal functional region of this promoter, which extends from the -342 bp position to the initiation codon, is differentially active in normal versus cancer cells. This GC rich region lacks p53 binding sites, but binds Klf4 and Sp3. This finding is likely to be of biological significance, as Klf4 and, to a lesser extent, Sp3 are up-regulated in a number of cancer cells where Notch1 expression is down-modulated, and Klf4 over-expression in normal cells is sufficient to down-modulate Notch1 gene transcription. The combined knock-down of Klf4 and Sp3 was necessary for the reverse effect of increasing Notch1 transcription, consistent with the two factors exerting an overlapping repressor function through their binding to the Notch1 promoter.

  6. Prolyl-isomerase Pin1 controls Notch3 protein expression and regulates T-ALL progression

    PubMed Central

    Franciosa, G; Diluvio, G; Gaudio, F Del; Giuli, M V; Palermo, R; Grazioli, P; Campese, A F; Talora, C; Bellavia, D; D'Amati, G; Besharat, Z M; Nicoletti, C; Siebel, C W; Choy, L; Rustighi, A; Sal, G Del; Screpanti, I; Checquolo, S

    2016-01-01

    Deregulated Notch signaling is associated with T-cell Acute Lymphoblastic Leukemia (T-ALL) development and progression. Increasing evidence reveals that Notch pathway has an important role in the invasion ability of tumor cells, including leukemia, although the underlying molecular mechanisms remain mostly unclear. Here, we show that Notch3 is a novel target protein of the prolyl-isomerase Pin1, which is able to regulate Notch3 protein processing and to stabilize the cleaved product, leading to the increased expression of the intracellular domain (N3IC), finally enhancing Notch3-dependent invasiveness properties. We demonstrate that the combined inhibition of Notch3 and Pin1 in the Notch3-overexpressing human leukemic TALL-1 cells reduces their high invasive potential, by decreasing the expression of the matrix metalloprotease MMP9. Consistently, Pin1 depletion in a mouse model of Notch3-induced T-ALL, by reducing N3IC expression and signaling, impairs the expansion/invasiveness of CD4+CD8+ DP cells in peripheral lymphoid and non-lymphoid organs. Notably, in in silico gene expression analysis of human T-ALL samples we observed a significant correlation between Pin1 and Notch3 expression levels, which may further suggest a key role of the newly identified Notch3-Pin1 axis in T-ALL aggressiveness and progression. Thus, combined suppression of Pin1 and Notch3 proteins may be exploited as an additional target therapy for T-ALL. PMID:26876201

  7. Prognostic significance of Notch 3 gene expression in ovarian serous carcinoma.

    PubMed

    Jung, Sang G; Kwon, Young D; Song, Ji A; Back, Min J; Lee, Sun Y; Lee, Chan; Hwang, Yoon Y; An, Hee J

    2010-09-01

    The Notch signaling pathway is an important cell signaling system, which regulates cell differentiation, proliferation, and apoptosis, and is aberrantly activated in a wide range of cancer, including ovarian cancers. However, it remains unclear as to whether Notch signaling plays a role in the progression and prognosis of ovarian cancer. We examined the mRNA and protein expression of Notch 3, Jagged 1, and Jagged 2 in 98 ovarian epithelial tumors via real-time PCR and in 175 tumors with immunohistochemical analysis, and then correlated their expression levels with clinicopathological parameters and patient survival. In this study, we detected high levels of Notch3 mRNA and protein expression especially in serous ovarian carcinomas compared to their benign counterparts, accompanied by a positive correlation with the expressions of Jagged 1 and Jagged 2. High levels of Notch 3 mRNA expression (>2-fold than that of benign tumor) were noted in 63% of the serous carcinomas (mean level: 17-fold, P = 0.032). Additionally, Notch 3 protein overexpression was significantly associated with advanced stage (P = 0.0008), lymph node (P = 0.001), and distant metastasis (P = 0.003). Notably, high Notch 3 mRNA and protein expressions were correlated with chemoresistance (P = 0.033) and poor overall survival (P = 0.027, P = 0.042) in these patients. Our results indicate that the Notch 3 signaling pathway is involved in the tumor progression of ovarian serous carcinoma, and higher Notch 3 expression may be an independent poor prognostic factor in this subset of tumors.

  8. Notch in the intestine: regulation of homeostasis and pathogenesis.

    PubMed

    Noah, Taeko K; Shroyer, Noah F

    2013-01-01

    The small and large intestines are tubular organs composed of several tissue types. The columnar epithelium that lines the inner surface of the intestines distinguishes the digestive physiology of each region of the intestine and consists of several distinct cell types that are rapidly and continually renewed by intestinal stem cells that reside near the base of the crypts of Lieberkühn. Notch signaling controls the fate of intestinal stem cells by regulating the expression of Hes genes and by repressing Atoh1. Alternate models of Notch pathway control of cell fate determination are presented. Roles for Notch signaling in development of the intestine, including mesenchymal and neural cells, are discussed. The oncogenic activities of Notch in colorectal cancer, as well as the tumor suppressive activities of Atoh1, are reviewed. Therapeutic targeting of the Notch pathway in colorectal cancers is discussed, along with potential caveats.

  9. Notch-regulated miR-223 targets the aryl hydrocarbon receptor pathway and increases cytokine production in macrophages from rheumatoid arthritis patients

    PubMed Central

    Ogando, Jesús; Tardáguila, Manuel; Díaz-Alderete, Andrea; Usategui, Alicia; Miranda-Ramos, Vanessa; Martínez-Herrera, Dannys Jorge; de la Fuente, Lorena; García-León, María J.; Moreno, María C.; Escudero, Sara; Cañete, Juan D.; Toribio, María L.; Cases, Ildefonso; Pascual-Montano, Alberto; Pablos, José Luis; Mañes, Santos

    2016-01-01

    Evidence links aryl hydrocarbon receptor (AHR) activation to rheumatoid arthritis (RA) pathogenesis, although results are inconsistent. AHR agonists inhibit pro-inflammatory cytokine expression in macrophages, pivotal cells in RA aetiopathogenesis, which hints at specific circuits that regulate the AHR pathway in RA macrophages. We compared microRNA (miR) expression in CD14+ cells from patients with active RA or with osteoarthritis (OA). Seven miR were downregulated and one (miR-223) upregulated in RA compared to OA cells. miR-223 upregulation correlated with reduced Notch3 and Notch effector expression in RA patients. Overexpression of the Notch-induced repressor HEY-1 and co-culture of healthy donor monocytes with Notch ligand-expressing cells showed direct Notch-mediated downregulation of miR-223. Bioinformatics predicted the AHR regulator ARNT (AHR nuclear translocator) as a miR-223 target. Pre-miR-223 overexpression silenced ARNT 3’UTR-driven reporter expression, reduced ARNT (but not AHR) protein levels and prevented AHR/ARNT-mediated inhibition of pro-inflammatory cytokine expression. miR-223 counteracted AHR/ARNT-induced Notch3 upregulation in monocytes. Levels of ARNT and of CYP1B1, an AHR/ARNT signalling effector, were reduced in RA compared to OA synovial tissue, which correlated with miR-223 levels. Our results associate Notch signalling to miR-223 downregulation in RA macrophages, and identify miR-223 as a negative regulator of the AHR/ARNT pathway through ARNT targeting. PMID:26838552

  10. SEPT4 is regulated by the Notch signaling pathway.

    PubMed

    Liu, Wenbin

    2012-04-01

    Notch receptor-mediated signaling is an evolutionarily conserved pathway that regulates diverse developmental processes and its dysregulation has been implicated in a variety of developmental disorders and cancers. Notch functions in these processes by activating expression of its target genes. Septin 4 (SEPT4) is a polymerizing GTP-binding protein that serves as scaffold for diverse molecules and is involved in cell proliferation and apoptosis. After activation of the Notch signal, the expression of SEPT4 is up-regulated and cell proliferation is inhibited. When the Notch signal is inhibited by the CSL (CBF1/Su(H)/Lag-1)-binding-domain-negative Mastermind-like protein 1, the expression of SEPT4 is down-regulated, proliferation and colony formation of cells are promoted, but cell adhesion ability is decreased. Nevertheless, the SEPT4 expression is not affected after knock-down of CSL. Meanwhile, if SEPT4 activity is inhibited through RNA interference, the protein level and activity of NOTCH1 remains unchanged, but cell proliferation is dysregulated. This indicates that SEPT4 is a Notch target gene. This relationship between Notch signaling pathway and SEPT4 offers a potential basis for further study of developmental control and carcinogenesis. PMID:21938432

  11. Nandrolone reduces activation of Notch signaling in denervated muscle associated with increased Numb expression

    SciTech Connect

    Liu, Xin-Hua; Yao, Shen; Qiao, Rui-Fang; Levine, Alice C.; Kirschenbaum, Alexander; Pan, Jiangping; Wu, Yong; Qin, Weiping; Bauman, William A.; Cardozo, Christopher P.

    2011-10-14

    Highlights: {yields} Nerve transection increased Notch signaling in paralyzed muscle. {yields} Nandrolone prevented denervation-induced Notch signaling. {yields} Nandrolone induced the expression of an inhibitor of the Notch signaling, Numb. {yields} Reduction of denervation-induced Notch signaling by nandrolone is likely through upregulation of Numb. -- Abstract: Nandrolone, an anabolic steroid, slows denervation-atrophy in rat muscle. The molecular mechanisms responsible for this effect are not well understood. Androgens and anabolic steroids activate Notch signaling in animal models of aging and thereby mitigate sarcopenia. To explore the molecular mechanisms by which nandrolone prevents denervation-atrophy, we investigated the effects of nandrolone on Notch signaling in denervated rat gastrocnemius muscle. Denervation significantly increased Notch activity reflected by elevated levels of nuclear Notch intracellular domain (NICD) and expression of Hey1 (a Notch target gene). Activation was greatest at 7 and 35 days after denervation but remained present at 56 days after denervation. Activation of Notch in denervated muscle was prevented by nandrolone associated with upregulated expression of Numb mRNA and protein. These data demonstrate that denervation activates Notch signaling, and that nandrolone abrogates this response associated with increased expression of Numb, suggesting a potential mechanism by which nandrolone reduces denervation-atrophy.

  12. Search for Basonuclin Target Genes

    PubMed Central

    Wang, Junwen; Zhang, Shengliang; Schultz, Richard M.; Tseng, Hung

    2006-01-01

    Basonuclin (Bnc 1) is a transcription factor that has an unusual ability to interact with promoters of both RNA polymerases I and II. The action of basonuclin is mediated through three pairs of evolutionarily conserved zinc fingers, which produce three DNase I footprints on the promoters of rDNA and the basonuclin gene. Using these DNase footprints, we built a computational model for the basonuclin DNA-binding module, which was used to identify in silico potential RNA polymerase II target genes in the human and mouse promoter databases. The target genes of basonuclin show that it regulates the expression of proteins involved in chromatin structure, transcription/DNA-binding, ion-channels, adhesion/cell-cell junction, signal transduction and intracellular transport. Our results suggest that basonuclin, like MYC, may coordinate transcriptional activities among the three RNA polymerases. But basonuclin regulates a distinctive set of pathways, which differ from that regulated by MYC. PMID:16919236

  13. Notch1 signaling regulates chondrogenic lineage determination through Sox9 activation.

    PubMed

    Haller, R; Schwanbeck, R; Martini, S; Bernoth, K; Kramer, J; Just, U; Rohwedel, J

    2012-03-01

    Notch signaling is involved in several cell lineage determination processes during embryonic development. Recently, we have shown that Sox9 is most likely a primary target gene of Notch1 signaling in embryonic stem cells (ESCs). By using our in vitro differentiation protocol for chondrogenesis from ESCs through embryoid bodies (EBs) together with our tamoxifen-inducible system to activate Notch1, we analyzed the function of Notch signaling and its induction of Sox9 during EB differentiation towards the chondrogenic lineage. Temporary activation of Notch1 during early stages of EB, when lineage determination occurs, was accompanied by rapid and transient Sox9 upregulation and resulted in induction of chondrogenic differentiation during later stages of EB cultivation. Using siRNA targeting Sox9, we knocked down and adjusted this early Notch1-induced Sox9 expression peak to non-induced levels, which led to reversion of Notch1-induced chondrogenic differentiation. In contrast, continuous Notch1 activation during EB cultivation resulted in complete inhibition of chondrogenic differentiation. Furthermore, a reduction and delay of cardiac differentiation observed in EBs after early Notch1 activation was not reversed by siRNA-mediated Sox9 knockdown. Our data indicate that Notch1 signaling has an important role during early stages of chondrogenic lineage determination by regulation of Sox9 expression. PMID:21869831

  14. NUMB is a break of WNT-Notch signaling cycle.

    PubMed

    Katoh, Masuko; Katoh, Masaru

    2006-09-01

    Notch, FGF and WNT signaling pathways cross-talk during embryogenesis, tissue regeneration and carcinogenesis. Notch-ligand binding to Notch receptors leads to the cleavage of Notch receptors and the following nuclear translocation of Notch intracellular domain (NICD) to induce transcriptional activation of Notch target genes. Notch signaling inhibitors, NUMB and NUMB-like (NUMBL), are docking proteins with PTB domain. We searched for the TCF/LEF-binding site within the promoter region of NUMB and NUMBL genes. Because two TCF/LEF-binding sites were identified within human NUMB promoter based on bioinformatics and human intelligence (Humint), comparative integromics analyses on NUMB orthologs were further performed. Chimpanzee NUBM gene, consisting of 13 exons, was identified within NW_115880.1 genome sequence. XM_510045.1 was not the correct coding sequence for chimpanzee NUMB. Chimpanzee NUMB gene was found to encode a 651-amino-acid protein showing 99.5, 93.9 and 82.6% total-amino-acid identity with human NUMB, mouse Numb and chicken numb, respectively. Human NUMB mRNA was expressed in placenta, ES cells, neural tissues, trachea, testis, uterus, thymus, coronary artery as well as in a variety of tumors, such as cervical cancer, tong tumor, brain tumor, colorectal and breast cancer. Although distal TCF/LEF-binding site within human NUMB promoter was conserved only among primate NUMB orthologs, proximal TCF/LEF-binding site was conserved among primate and rodent NUMB orthologs. NUMB, JAG1, FGF18, FGF20 and SPRY4 are potent targets of the canonical WNT signaling pathway in progenitor cells. NUMB inhibits Notch signaling in progenitor cells to induce differentiation, while JAG1 activates Notch signaling in stem cells to maintain self-renewal potential. Because Notch signaling inhibitor NUMB was identified as the safe apparatus for the WNT - Notch signaling cycle, epigenetic silencing, deletion and loss-of-function mutation of NUMB gene could lead to carcinogenesis

  15. Mechanisms of gene targeting in higher eukaryotes.

    PubMed

    Tokunaga, Akinori; Anai, Hirofumi; Hanada, Katsuhiro

    2016-02-01

    Targeted genome modifications using techniques that alter the genomic information of interest have contributed to multiple studies in both basic and applied biology. Traditionally, in gene targeting, the target-site integration of a targeting vector by homologous recombination is used. However, this strategy has several technical problems. The first problem is the extremely low frequency of gene targeting, which makes obtaining recombinant clones an extremely labor intensive task. The second issue is the limited number of biomaterials to which gene targeting can be applied. Traditional gene targeting hardly occurs in most of the human adherent cell lines. However, a new approach using designer nucleases that can introduce site-specific double-strand breaks in genomic DNAs has increased the efficiency of gene targeting. This new method has also expanded the number of biomaterials to which gene targeting could be applied. Here, we summarize various strategies for target gene modification, including a comparison of traditional gene targeting with designer nucleases.

  16. Notch signaling in gastrointestinal tract (review).

    PubMed

    Katoh, Masuko; Katoh, Masaru

    2007-01-01

    Notch signaling is one of key pathways constituting the stem cell signaling network. DLL1, DLL3, DLL4, JAG1 and JAG2 with DSL domain are typical Notch ligands, while DNER, F3/Contactin and NB-3 without DSL domain are atypical Notch ligands. Notch-ligand binding to NOTCH1, NOTCH2, NOTCH3 or NOTCH4 receptor induces the receptor proteolysis by metalloprotease and gamma-secretase to release Notch intracellular domain (NICD). Typical Notch ligands transduce signals to the CSL-NICD-Mastermind complex for the maintenance of stem or progenitor (transit-amplifying) cells through transcriptional activation of HES1, HES5, HES7, HEY1, HEY2 and HEYL genes, and also to the NF-kappaB-NICD complex for the augmentation of NF-kappaB signaling. Atypical Notch ligands transduce signals to the CSL-NICD-Deltex complex for the differentiation of progenitor cells through MAG transcriptional activation. Notch signals are transduced to the canonical pathway (CSL-NICD-Mastermind signaling cascade) or the non-canonical pathway (NF-kappaB-NICD and CSL-NICD-Deltex signaling cascades) based on the expression profile of Notch ligands, Notch receptors, and Notch signaling modifiers. Canonical Notch signaling is activated in the stem or progenitor domain of gastrointestinal epithelium, such as basal layer in esophagus and lower part of the crypt in colon. Notch signaling to inhibit secretory cell differentiation is oncogenic in gastric cancer and colorectal cancer, while Notch signaling to promote keratinocyte differentiation is anti-oncogenic in esophageal squamous cell carcinoma (SCC). Single nucleotide polymorphism (SNP), epigenetic change, and genetic alteration of genes encoding Notch signaling-associated molecules will be utilized as biomarkers for gastrointestinal cancer. gamma-Secretase inhibitors, functioning as Notch signaling inhibitors, will be applied as anti-cancer drugs for gastric cancer and colorectal cancer.

  17. Targeted gene flow for conservation.

    PubMed

    Kelly, Ella; Phillips, Ben L

    2016-04-01

    Anthropogenic threats often impose strong selection on affected populations, causing rapid evolutionary responses. Unfortunately, these adaptive responses are rarely harnessed for conservation. We suggest that conservation managers pay close attention to adaptive processes and geographic variation, with an eye to using them for conservation goals. Translocating pre-adapted individuals into recipient populations is currently considered a potentially important management tool in the face of climate change. Targeted gene flow, which involves moving individuals with favorable traits to areas where these traits would have a conservation benefit, could have a much broader application in conservation. Across a species' range there may be long-standing geographic variation in traits or variation may have rapidly developed in response to a threatening process. Targeted gene flow could be used to promote natural resistance to threats to increase species resilience. We suggest that targeted gene flow is a currently underappreciated strategy in conservation that has applications ranging from the management of invasive species and their impacts to controlling the impact and virulence of pathogens.

  18. Ehrlichia chaffeensis TRP120 Activates Canonical Notch Signaling To Downregulate TLR2/4 Expression and Promote Intracellular Survival

    PubMed Central

    Lina, Taslima T.; Dunphy, Paige S.; Luo, Tian

    2016-01-01

    ABSTRACT Ehrlichia chaffeensis preferentially targets mononuclear phagocytes and survives through a strategy of subverting innate immune defenses, but the mechanisms are unknown. We have shown E. chaffeensis type 1 secreted tandem repeat protein (TRP) effectors are involved in diverse molecular pathogen-host interactions, such as the TRP120 interaction with the Notch receptor-cleaving metalloprotease ADAM17. In the present study, we demonstrate E. chaffeensis, via the TRP120 effector, activates the canonical Notch signaling pathway to promote intracellular survival. We found that nuclear translocation of the transcriptionally active Notch intracellular domain (NICD) occurs in response to E. chaffeensis or recombinant TRP120, resulting in upregulation of Notch signaling pathway components and target genes notch1, adam17, hes, and hey. Significant differences in canonical Notch signaling gene expression levels (>40%) were observed during early and late stages of infection, indicating activation of the Notch pathway. We linked Notch pathway activation specifically to the TRP120 effector, which directly interacts with the Notch metalloprotease ADAM17. Using pharmacological inhibitors and small interfering RNAs (siRNAs) against γ-secretase enzyme, Notch transcription factor complex, Notch1, and ADAM17, we demonstrated that Notch signaling is required for ehrlichial survival. We studied the downstream effects and found that E. chaffeensis TRP120-mediated activation of the Notch pathway causes inhibition of the extracellular signal-regulated kinase 1/2 (ERK1/2) and p38 mitogen-activated protein kinase (MAPK) pathways required for PU.1 and subsequent Toll-like receptor 2/4 (TLR2/4) expression. This investigation reveals a novel mechanism whereby E. chaffeensis exploits the Notch pathway to evade the host innate immune response for intracellular survival. PMID:27381289

  19. Activation of the Notch signaling pathway in response to pulp capping of rat molars.

    PubMed

    Løvschall, H; Tummers, M; Thesleff, I; Füchtbauer, E-M; Poulsen, K

    2005-08-01

    Notch signaling is an evolutionarily conserved pathway that controls the developmental choices made by individual cells. Cells communicate via Notch receptors and their ligands, which direct decisions on the fate of stem cells according to the states of their neighbors. In this study we explored Notch signaling after the pulp capping of adult first upper rat molars. The wound was capped with calcium hydroxide. In situ hybridization revealed an increased expression of Notch signaling genes on day 1, which showed a tendency to decrease on day 3. Notch1 increased in the subodontoblast zone and close to the lesion limited to a few cells. Notch2 increased in pulp stroma surrounded by coronal odontoblasts. Notch1 and, especially, Notch3 expression increased, corresponding to perivascular cell groups. A low increase of ligand expression was observed near the injury with Delta1 expression along the dentin wall and Jagged1 in the stroma. Expression of the downstream target, Hes1, was observed along the lesion and adjacent dentin walls. Hes5 expression was not observed. The results indicate that Notch signaling is activated in response to injury and associated with the differentiation of pulp cells into perivascular cells and odontoblasts. The findings are consistent with the concept that the Notch pathway controls stem cell fate during pulp regeneration. PMID:16048523

  20. Notch cooperates with Lozenge/Runx to lock haemocytes into a differentiation programme.

    PubMed

    Terriente-Felix, Ana; Li, Jinghua; Collins, Stephanie; Mulligan, Amy; Reekie, Ian; Bernard, Fred; Krejci, Alena; Bray, Sarah

    2013-02-01

    The diverse functions of Notch signalling imply that it must elicit context-specific programmes of gene expression. With the aim of investigating how Notch drives cells to differentiate, we have used a genome-wide approach to identify direct Notch targets in Drosophila haemocytes (blood cells), where Notch promotes crystal cell differentiation. Many of the identified Notch-regulated enhancers contain Runx and GATA motifs, and we demonstrate that binding of the Runx protein Lozenge (Lz) is required for enhancers to be competent to respond to Notch. Functional studies of targets, such as klumpfuss (ERG/WT1 family) and pebbled/hindsight (RREB1 homologue), show that Notch acts both to prevent the cells adopting alternate cell fates and to promote morphological characteristics associated with crystal cell differentiation. Inappropriate activity of Klumpfuss perturbs the differentiation programme, resulting in melanotic tumours. Thus, by acting as a master regulator, Lz directs Notch to activate selectively a combination of target genes that correctly locks cells into the differentiation programme. PMID:23325760

  1. A novel non-canonical Notch signaling regulates expression of synaptic vesicle proteins in excitatory neurons

    PubMed Central

    Hayashi, Yukari; Nishimune, Hiroshi; Hozumi, Katsuto; Saga, Yumiko; Harada, Akihiro; Yuzaki, Michisuke; Iwatsubo, Takeshi; Kopan, Raphael; Tomita, Taisuke

    2016-01-01

    Notch signaling plays crucial roles for cellular differentiation during development through γ-secretase-dependent intramembrane proteolysis followed by transcription of target genes. Although recent studies implicate that Notch regulates synaptic plasticity or cognitive performance, the molecular mechanism how Notch works in mature neurons remains uncertain. Here we demonstrate that a novel Notch signaling is involved in expression of synaptic proteins in postmitotic neurons. Levels of several synaptic vesicle proteins including synaptophysin 1 and VGLUT1 were increased when neurons were cocultured with Notch ligands-expressing NIH3T3 cells. Neuron-specific deletion of Notch genes decreased these proteins, suggesting that Notch signaling maintains the expression of synaptic vesicle proteins in a cell-autonomous manner. Unexpectedly, cGMP-dependent protein kinase (PKG) inhibitor, but not γ-secretase inhibitor, abolished the elevation of synaptic vesicle proteins, suggesting that generation of Notch intracellular domain is dispensable for this function. These data uncover a ligand-dependent, but γ-secretase-independent, non-canonical Notch signaling involved in presynaptic protein expression in postmitotic neurons. PMID:27040987

  2. Scapular Notching.

    PubMed

    Dare, David; Dines, Joshua S; Tebo, Collin; Edwards, T Bradley; Craig, Edward V; Dines, David M

    2016-01-01

    Developed in 1985, the Grammont-style reverse total shoulder arthroplasty offered a biomechanical advantage for the deltoid muscle as well as predictably reduced pain and improved shoulder function in rotator cuff-deficient shoulders. Despite favorable outcomes, reverse total shoulder arthroplasty is associated with a unique set of complications, one of which is scapular notching. Scapular notching is believed to be a result of mechanical impingement of the humeral component on the lateral scapular pillar. Although it appears that scapular notching progresses with time, its effect on implant survivorship and clinical outcomes is unknown. Factors associated with scapular notching are categorized into several groups, including patient-specific risk factors, surgical approach and technique, and prosthetic design. Surgical strategies to reduce the rate of scapular notching include inferior positioning of the glenosphere, inferior tilting of the glenosphere, and increasing the size of the glenosphere. A lateralized center of rotation and a decreased humeral shaft-neck angle also decrease the incidence of scapular notching. As the indications for reverse total shoulder arthroplasty expand, it is important for orthopaedic surgeons to understand the etiology and incidence, predictive factors, and clinical relevance of scapular notching as well as strategies to avoid it. PMID:27049187

  3. The Dmp1-SOST Transgene Interacts With and Downregulates the Dmp1-Cre Transgene and the Rosa(Notch) Allele.

    PubMed

    Zanotti, Stefano; Canalis, Ernesto

    2016-05-01

    Activation of Notch1 in osteocytes of Rosa(Notch) mice, where a loxP-flanked STOP cassette and the Nicd coding sequence were targeted to the reverse orientation splice acceptor (Rosa)26 locus, causes osteopetrosis associated with suppressed Sost expression and enhanced Wnt signaling. To determine whether Sost downregulation mediates the effects of Notch activation in osteocytes, Rosa(Notch) mice were crossed with transgenics expressing Cre recombinase or SOST under the control of the dentin matrix protein (Dmp)1 promoter. Dmp1-SOST transgenics displayed vertebral osteopenia and a modest femoral cancellous and cortical bone phenotype, whereas hemizygous Dmp1-Cre transgenics heterozygous for the Rosa(Notch) allele (Dmp1-Cre;Rosa(Notch)) exhibited osteopetrosis. The phenotype of Notch activation in osteocytes was prevented in Dmp1-Cre;Rosa(Notch) mice hemizygous for the Dmp1-SOST transgene. The effect was associated with downregulated Notch signaling and suppressed Dmp1 and Rosa26 expression. To test whether SOST regulates Notch expression in osteocytes, cortical bone cultures from Dmp1-Cre;Rosa(Notch) mice or from Rosa(Notch) control littermates were exposed to recombinant human SOST. The addition of SOST had only modest effects on Notch target gene mRNA levels and suppressed Dmp1, but not Cre or Rosa26, expression. These findings suggest that prevention of the Dmp1-Cre;Rosa(Notch) skeletal phenotype by Dmp1-SOST is not secondary to SOST expression but to interactions among the Dmp1-SOST and Dmp1-Cre transgenes and the Rosa26 locus. In conclusion, the Dmp1-SOST transgene suppresses the expression of the Dmp1-Cre transgene and of Rosa26. PMID:26456319

  4. The Notch driven long non-coding RNA repertoire in T-cell acute lymphoblastic leukemia.

    PubMed

    Durinck, Kaat; Wallaert, Annelynn; Van de Walle, Inge; Van Loocke, Wouter; Volders, Pieter-Jan; Vanhauwaert, Suzanne; Geerdens, Ellen; Benoit, Yves; Van Roy, Nadine; Poppe, Bruce; Soulier, Jean; Cools, Jan; Mestdagh, Pieter; Vandesompele, Jo; Rondou, Pieter; Van Vlierberghe, Pieter; Taghon, Tom; Speleman, Frank

    2014-12-01

    Genetic studies in T-cell acute lymphoblastic leukemia have uncovered a remarkable complexity of oncogenic and loss-of-function mutations. Amongst this plethora of genetic changes, NOTCH1 activating mutations stand out as the most frequently occurring genetic defect, identified in more than 50% of T-cell acute lymphoblastic leukemias, supporting a role as an essential driver for this gene in T-cell acute lymphoblastic leukemia oncogenesis. In this study, we aimed to establish a comprehensive compendium of the long non-coding RNA transcriptome under control of Notch signaling. For this purpose, we measured the transcriptional response of all protein coding genes and long non-coding RNAs upon pharmacological Notch inhibition in the human T-cell acute lymphoblastic leukemia cell line CUTLL1 using RNA-sequencing. Similar Notch dependent profiles were established for normal human CD34(+) thymic T-cell progenitors exposed to Notch signaling activity in vivo. In addition, we generated long non-coding RNA expression profiles (array data) from ex vivo isolated Notch active CD34(+) and Notch inactive CD4(+)CD8(+) thymocytes and from a primary cohort of 15 T-cell acute lymphoblastic leukemia patients with known NOTCH1 mutation status. Integration of these expression datasets with publicly available Notch1 ChIP-sequencing data resulted in the identification of long non-coding RNAs directly regulated by Notch activity in normal and malignant T cells. Given the central role of Notch in T-cell acute lymphoblastic leukemia oncogenesis, these data pave the way for the development of novel therapeutic strategies that target hyperactive Notch signaling in human T-cell acute lymphoblastic leukemia.

  5. Heat shock protein 70 (Hsp70) interacts with the Notch1 intracellular domain and contributes to the activity of Notch signaling in myelin-reactive CD4 T cells.

    PubMed

    Juryńczyk, Maciej; Lewkowicz, Przemysław; Domowicz, Małgorzata; Mycko, Marcin P; Selmaj, Krzysztof W

    2015-10-15

    Notch receptors (Notch1-4) are involved in the differentiation of CD4 T cells and the development of autoimmunity. Mechanisms regulating Notch signaling in CD4 T cells are not fully elucidated. In this study we investigated potential crosstalk between Notch pathway molecules and heat shock protein 70 (Hsp70), the major intracellular chaperone involved in the protein transport during immune responses and other stress conditions. Using Hsp70(-/-) mice we found that Hsp70 is critical for up-regulation of NICD1 and induction of Notch target genes in Jagged1- and Delta-like1-stimulated CD4 T cells. Co-immunoprecipitation analysis of wild-type CD4 T cells stimulated with either Jagged1 or Delta-like1 showed a direct interaction between NICD1 and Hsp70. Both molecules co-localized within the nucleus of CD4 T cells stimulated with Notch ligands. Molecular interaction and nuclear colocalization of NICD1 and Hsp70 were also detected in CD4 T cells reactive against myelin oligodendrocyte glycoprotein (MOG)35-55, which showed Hsp70-dependent up-regulation of both NICD1 and Notch target genes. In conclusion, we demonstrate for the first time that Hsp70 interacts with NICD1 and contributes to the activity of Notch signaling in CD4 T cells. Interaction between Hsp70 and NICD1 may represent a novel mechanism regulating Notch signaling in activated CD4 T cells.

  6. Evolution of the chordate regeneration blastema: Differential gene expression and conserved role of notch signaling during siphon regeneration in the ascidian Ciona.

    PubMed

    Hamada, Mayuko; Goricki, Spela; Byerly, Mardi S; Satoh, Noriyuki; Jeffery, William R

    2015-09-15

    The regeneration of the oral siphon (OS) and other distal structures in the ascidian Ciona intestinalis occurs by epimorphosis involving the formation of a blastema of proliferating cells. Despite the longstanding use of Ciona as a model in molecular developmental biology, regeneration in this system has not been previously explored by molecular analysis. Here we have employed microarray analysis and quantitative real time RT-PCR to identify genes with differential expression profiles during OS regeneration. The majority of differentially expressed genes were downregulated during OS regeneration, suggesting roles in normal growth and homeostasis. However, a subset of differentially expressed genes was upregulated in the regenerating OS, suggesting functional roles during regeneration. Among the upregulated genes were key members of the Notch signaling pathway, including those encoding the delta and jagged ligands, two fringe modulators, and to a lesser extent the notch receptor. In situ hybridization showed a complementary pattern of delta1 and notch gene expression in the blastema of the regenerating OS. Chemical inhibition of the Notch signaling pathway reduced the levels of cell proliferation in the branchial sac, a stem cell niche that contributes progenitor cells to the regenerating OS, and in the OS regeneration blastema, where siphon muscle fibers eventually re-differentiate. Chemical inhibition also prevented the replacement of oral siphon pigment organs, sensory receptors rimming the entrance of the OS, and siphon muscle fibers, but had no effects on the formation of the wound epidermis. Since Notch signaling is involved in the maintenance of proliferative activity in both the Ciona and vertebrate regeneration blastema, the results suggest a conserved evolutionary role of this signaling pathway in chordate regeneration. The genes identified in this investigation provide the foundation for future molecular analysis of OS regeneration.

  7. Evolution of the chordate regeneration blastema: Differential gene expression and conserved role of notch signaling during siphon regeneration in the ascidian Ciona.

    PubMed

    Hamada, Mayuko; Goricki, Spela; Byerly, Mardi S; Satoh, Noriyuki; Jeffery, William R

    2015-09-15

    The regeneration of the oral siphon (OS) and other distal structures in the ascidian Ciona intestinalis occurs by epimorphosis involving the formation of a blastema of proliferating cells. Despite the longstanding use of Ciona as a model in molecular developmental biology, regeneration in this system has not been previously explored by molecular analysis. Here we have employed microarray analysis and quantitative real time RT-PCR to identify genes with differential expression profiles during OS regeneration. The majority of differentially expressed genes were downregulated during OS regeneration, suggesting roles in normal growth and homeostasis. However, a subset of differentially expressed genes was upregulated in the regenerating OS, suggesting functional roles during regeneration. Among the upregulated genes were key members of the Notch signaling pathway, including those encoding the delta and jagged ligands, two fringe modulators, and to a lesser extent the notch receptor. In situ hybridization showed a complementary pattern of delta1 and notch gene expression in the blastema of the regenerating OS. Chemical inhibition of the Notch signaling pathway reduced the levels of cell proliferation in the branchial sac, a stem cell niche that contributes progenitor cells to the regenerating OS, and in the OS regeneration blastema, where siphon muscle fibers eventually re-differentiate. Chemical inhibition also prevented the replacement of oral siphon pigment organs, sensory receptors rimming the entrance of the OS, and siphon muscle fibers, but had no effects on the formation of the wound epidermis. Since Notch signaling is involved in the maintenance of proliferative activity in both the Ciona and vertebrate regeneration blastema, the results suggest a conserved evolutionary role of this signaling pathway in chordate regeneration. The genes identified in this investigation provide the foundation for future molecular analysis of OS regeneration. PMID:26206613

  8. hCLP46 regulates U937 cell proliferation via Notch signaling pathway

    SciTech Connect

    Ma, Wenzhan; Du, Jie; Chu, Qiaoyun; Wang, Youxin; Liu, Lixin; Song, Manshu; Wang, Wei

    2011-04-29

    Highlights: {yields} Knock down of hCLP46 by RNAi impairs mammalian Notch signaling. {yields} hCLP46 affects neither cell surface Notch1 expression nor ligand-receptor binding. {yields} Knock down of hCLP46 inhibits U937 cell-growth by up-regulation of CDKN1B. -- Abstract: Human CAP10-like protein 46 kDa (hCLP46) is the homolog of Rumi, which is the first identified protein O-glucosyltransferase that modifies Notch receptor in Drosophila. Dysregulation of hCLP46 occurs in many hematologic diseases, but the role of hCLP46 remains unclear. Knockdown of hCLP46 by RNA interference resulted in decreased protein levels of endogenous Notch1, Notch intracellular domain (NICD) and Notch target gene Hes-1, suggesting the impairment of the Notch signaling. However, neither cell surface Notch expression nor ligand binding activities were affected. In addition, down-regulated expression of hCLP46 inhibited the proliferation of U937 cells, which was correlated with increased cyclin-dependent kinase inhibitor (CDKI) CDKN1B (p27) and decreased phosphorylation of retinoblastoma (RB) protein. We showed that lack of hCLP46 results in impaired ligand induced Notch activation in mammalian cell, and hCLP46 regulates the proliferation of U937 cell through CDKI-RB signaling pathway, which may be important for the pathogenesis of leukemia.

  9. Non-Canonical Notch Signaling Drives Activation and Differentiation of Peripheral CD4+ T Cells

    PubMed Central

    Dongre, Anushka; Surampudi, Lalitha; Lawlor, Rebecca G.; Fauq, Abdul H.; Miele, Lucio; Golde, Todd E.; Minter, Lisa M.; Osborne, Barbara A.

    2014-01-01

    Cleavage of the Notch receptor via a γ-secretase, results in the release of the active intra-cellular domain of Notch that migrates to the nucleus and interacts with RBP-Jκ, resulting in the activation of downstream target genes. This canonical Notch signaling pathway has been documented to influence T cell development and function. However, the mechanistic details underlying this process remain obscure. In addition to RBP-Jκ, the intra-cellular domain of Notch also interacts with other proteins in the cytoplasm and nucleus, giving rise to the possibility of an alternate, RBP-Jκ independent Notch pathway. However, the contribution of such RBP-Jκ independent, “non-canonical” Notch signaling in regulating peripheral T cell responses is unknown. In this report, we specifically demonstrate the requirement of Notch1 for regulating signal strength and signaling events distal to the T cell receptor in peripheral CD4+ T cells. By using mice with a conditional deletion in Notch1 or RBP-Jκ, we show that Notch1 regulates activation and proliferation of CD4+ T cells independently of RBP-Jκ. Furthermore, differentiation to TH1 and iTreg lineages although Notch dependent, is RBP-Jκ independent. Our striking observations demonstrate that many of the cell-intrinsic functions of Notch occur independently of RBP-Jκ. Such non-canonical regulation of these processes likely occurs through NF-κ B. This reveals a previously unknown, novel role of non-canonical Notch signaling in regulating peripheral T cell responses. PMID:24611064

  10. Regulation of Notch Signaling by an Evolutionary Conserved DEAD Box RNA Helicase, Maheshvara in Drosophila melanogaster.

    PubMed

    Surabhi, Satya; Tripathi, Bipin K; Maurya, Bhawana; Bhaskar, Pradeep K; Mukherjee, Ashim; Mutsuddi, Mousumi

    2015-11-01

    Notch signaling is an evolutionary conserved process that influences cell fate determination, cell proliferation, and cell death in a context-dependent manner. Notch signaling is fine-tuned at multiple levels and misregulation of Notch has been implicated in a variety of human diseases. We have characterized maheshvara (mahe), a novel gene in Drosophila melanogaster that encodes a putative DEAD box protein that is highly conserved across taxa and belongs to the largest group of RNA helicase. A dynamic pattern of mahe expression along with the maternal accumulation of its transcripts is seen during early stages of embryogenesis. In addition, a strong expression is also seen in the developing nervous system. Ectopic expression of mahe in a wide range of tissues during development results in a variety of defects, many of which resemble a typical Notch loss-of-function phenotype. We illustrate that ectopic expression of mahe in the wing imaginal discs leads to loss of Notch targets, Cut and Wingless. Interestingly, Notch protein levels are also lowered, whereas no obvious change is seen in the levels of Notch transcripts. In addition, mahe overexpression can significantly rescue ectopic Notch-mediated proliferation of eye tissue. Further, we illustrate that mahe genetically interacts with Notch and its cytoplasmic regulator deltex in trans-heterozygous combination. Coexpression of Deltex and Mahe at the dorso-ventral boundary results in a wing-nicking phenotype and a more pronounced loss of Notch target Cut. Taken together we report identification of a novel evolutionary conserved RNA helicase mahe, which plays a vital role in regulation of Notch signaling.

  11. Notch Antennas

    NASA Technical Reports Server (NTRS)

    Lee, Richard Q.

    2004-01-01

    Notch antennas, also known as the tapered slot antenna (TSA), have been the topics of research for decades. TSA has demonstrated multi-octave bandwidth, moderate gain (7 to 10 dB), and symmetric E- and H- plane beam patterns and can be used for many different applications. This chapter summarizes the research activities on notch antennas over the past decade with emphasis on their most recent advances and applications. This chapter begins with some discussions on the designs of single TSA; then follows with detailed discussions of issues associated with TSA designs and performance characteristics. To conclude the chapter, some recent developments in TSA arrays and their applications are highlighted.

  12. The drug target genes show higher evolutionary conservation than non-target genes.

    PubMed

    Lv, Wenhua; Xu, Yongdeng; Guo, Yiying; Yu, Ziqi; Feng, Guanglong; Liu, Panpan; Luan, Meiwei; Zhu, Hongjie; Liu, Guiyou; Zhang, Mingming; Lv, Hongchao; Duan, Lian; Shang, Zhenwei; Li, Jin; Jiang, Yongshuai; Zhang, Ruijie

    2016-01-26

    Although evidence indicates that drug target genes share some common evolutionary features, there have been few studies analyzing evolutionary features of drug targets from an overall level. Therefore, we conducted an analysis which aimed to investigate the evolutionary characteristics of drug target genes. We compared the evolutionary conservation between human drug target genes and non-target genes by combining both the evolutionary features and network topological properties in human protein-protein interaction network. The evolution rate, conservation score and the percentage of orthologous genes of 21 species were included in our study. Meanwhile, four topological features including the average shortest path length, betweenness centrality, clustering coefficient and degree were considered for comparison analysis. Then we got four results as following: compared with non-drug target genes, 1) drug target genes had lower evolutionary rates; 2) drug target genes had higher conservation scores; 3) drug target genes had higher percentages of orthologous genes and 4) drug target genes had a tighter network structure including higher degrees, betweenness centrality, clustering coefficients and lower average shortest path lengths. These results demonstrate that drug target genes are more evolutionarily conserved than non-drug target genes. We hope that our study will provide valuable information for other researchers who are interested in evolutionary conservation of drug targets.

  13. PTEN mediates Notch-dependent stalk cell arrest in angiogenesis.

    PubMed

    Serra, Helena; Chivite, Iñigo; Angulo-Urarte, Ana; Soler, Adriana; Sutherland, James D; Arruabarrena-Aristorena, Amaia; Ragab, Anan; Lim, Radiance; Malumbres, Marcos; Fruttiger, Marcus; Potente, Michael; Serrano, Manuel; Fabra, Àngels; Viñals, Francesc; Casanovas, Oriol; Pandolfi, Pier Paolo; Bigas, Anna; Carracedo, Arkaitz; Gerhardt, Holger; Graupera, Mariona

    2015-07-31

    Coordinated activity of VEGF and Notch signals guides the endothelial cell (EC) specification into tip and stalk cells during angiogenesis. Notch activation in stalk cells leads to proliferation arrest via an unknown mechanism. By using gain- and loss-of-function gene-targeting approaches, here we show that PTEN is crucial for blocking stalk cell proliferation downstream of Notch, and this is critical for mouse vessel development. Endothelial deletion of PTEN results in vascular hyperplasia due to a failure to mediate Notch-induced proliferation arrest. Conversely, overexpression of PTEN reduces vascular density and abrogates the increase in EC proliferation induced by Notch blockade. PTEN is a lipid/protein phosphatase that also has nuclear phosphatase-independent functions. We show that both the catalytic and non-catalytic APC/C-Fzr1/Cdh1-mediated activities of PTEN are required for stalk cells' proliferative arrest. These findings define a Notch-PTEN signalling axis as an orchestrator of vessel density and implicate the PTEN-APC/C-Fzr1/Cdh1 hub in angiogenesis.

  14. Therapeutic Targeting of Tumor Suppressor Genes

    PubMed Central

    Morris, Luc G. T.; Chan, Timothy A.

    2015-01-01

    Carcinogenesis is a multistep process attributable to both gain-of-function mutations in oncogenes and loss-of-function mutations in tumor suppressor genes. Currently, most molecular targeted therapies are inhibitors of oncogenes, because inactivated tumor suppressor genes have proven harder to “drug.” Nevertheless, in cancers, tumor suppressor genes undergo alteration more frequently than do oncogenes. In recent years, several promising strategies directed at tumor suppressor genes, or the pathways controlled by these genes, have emerged. Here, we describe advances in a number of different methodologies aimed at therapeutically targeting tumors driven by inactivated tumor suppressor genes. PMID:25557041

  15. Notch filter

    NASA Technical Reports Server (NTRS)

    Shelton, G. B. (Inventor)

    1977-01-01

    A notch filter for the selective attenuation of a narrow band of frequencies out of a larger band was developed. A helical resonator is connected to an input circuit and an output circuit through discrete and equal capacitors, and a resistor is connected between the input and the output circuits.

  16. Problem-Solving Test: Targeted Gene Disruption

    ERIC Educational Resources Information Center

    Szeberenyi, Jozsef

    2008-01-01

    Mutational inactivation of a specific gene is the most powerful technique to analyze the biological function of the gene. This approach has been used for a long time in viruses, bacteria, yeast, and fruit fly, but looked quite hopeless in more complex organisms. Targeted inactivation of specific genes (also known as knock-out mutation) in mice is…

  17. Engineering targeted viral vectors for gene therapy.

    PubMed

    Waehler, Reinhard; Russell, Stephen J; Curiel, David T

    2007-08-01

    To achieve therapeutic success, transfer vehicles for gene therapy must be capable of transducing target cells while avoiding impact on non-target cells. Despite the high transduction efficiency of viral vectors, their tropism frequently does not match the therapeutic need. In the past, this lack of appropriate targeting allowed only partial exploitation of the great potential of gene therapy. Substantial progress in modifying viral vectors using diverse techniques now allows targeting to many cell types in vitro. Although important challenges remain for in vivo applications, the first clinical trials with targeted vectors have already begun to take place.

  18. Nuclear Localization of the Autism Candidate Gene Neurobeachin and Functional Interaction with the NOTCH1 Intracellular Domain Indicate a Role in Regulating Transcription

    PubMed Central

    Tuand, Krizia; Stijnen, Pieter; Volders, Karolien; Declercq, Jeroen; Nuytens, Kim; Meulemans, Sandra; Creemers, John

    2016-01-01

    Background Neurobeachin (NBEA) is an autism spectrum disorders (ASD) candidate gene. NBEA deficiency affects regulated secretion, receptor trafficking, synaptic architecture and protein kinase A (PKA)-mediated phosphorylation. NBEA is a large multidomain scaffolding protein. From N- to C-terminus, NBEA has a concanavalin A-like lectin domain flanked by armadillo repeats (ACA), an A-kinase anchoring protein domain that can bind to PKA, a domain of unknown function (DUF1088) and a BEACH domain, preceded by a pleckstrin homology-like domain and followed by WD40 repeats (PBW). Although most of these domains mediate protein-protein interactions, no interaction screen has yet been performed. Methods Yeast two-hybrid screens with the ACA and PBW domain modules of NBEA gave a list of interaction partners, which were analyzed for Gene Ontology (GO) enrichment. Neuro-2a cells were used for confocal microscopy and nuclear extraction analysis. NOTCH-mediated transcription was studied with luciferase reporter assays and qRT-PCR, combined with NBEA knockdown or overexpression. Results Both domain modules showed a GO enrichment for the nucleus. PBW almost exclusively interacted with transcription regulators, while ACA interacted with a number of PKA substrates. NBEA was partially localized in the nucleus of Neuro-2a cells, albeit much less than in the cytoplasm. A nuclear localization signal was found in the DUF1088 domain, which was shown to contribute to the nuclear localization of an EGFP-DPBW fusion protein. Yeast two-hybrid identified the Notch1 intracellular domain as a physical interactor of the PBW domain and a role for NBEA as a negative regulator in Notch-mediated transcription was demonstrated. Conclusion Defining novel interaction partners of conserved NBEA domain modules identified a role for NBEA as transcriptional regulator in the nucleus. The physical interaction of NBEA with NOTCH1 is most relevant for ASD pathogenesis because NOTCH signaling is essential for

  19. Cellular senescence checkpoint function determines differential Notch1-dependent oncogenic and tumor suppressor activities

    PubMed Central

    Kagawa, Shingo; Natsuizaka, Mitsuteru; Whelan, Kelly A.; Facompre, Nicole; Naganuma, Seiji; Ohashi, Shinya; Kinugasa, Hideaki; Egloff, Ann Marie; Basu, Devraj; Gimotty, Phyllis A.; Klein-Szanto, Andres J; Bass, Adam; Wong, Kwok-Kin; Diehl, J. Alan; Rustgi, Anil K.; Nakagawa, Hiroshi

    2014-01-01

    Notch activity regulates tumor biology in a context-dependent and complex manner. Notch may act as an oncogene or a tumor suppressor gene even within the same tumor type. Recently, Notch signaling has been implicated in cellular senescence. Yet, it remains unclear as to how cellular senescence checkpoint functions may interact with Notch-mediated oncogenic and tumor suppressor activities. Herein, we used genetically engineered human esophageal keratinocytes and esophageal squamous cell carcinoma cells to delineate the functional consequences of Notch activation and inhibition along with pharmacological intervention and RNA interference (RNAi) experiments. When expressed in a tetracycline-inducible manner, the ectopically expressed activated form of Notch1 (ICN1) displayed oncogene-like characteristics inducing cellular senescence corroborated by the induction of G0/G1 cell-cycle arrest, Rb dephosphorylation, flat and enlarged cell morphology and senescence-associated β-galactosidase activity. Notch-induced senescence involves canonical CSL/RBPJ-dependent transcriptional activity and the p16INK4A-Rb pathway. Loss of p16INK4A or the presence of human papilloma virus (HPV) E6/E7 oncogene products not only prevented ICN1 from inducing senescence, but permitted ICN1 to facilitate anchorage-independent colony formation and xenograft tumor growth with increased cell proliferation and reduced squamous-cell differentiation. Moreover, Notch1 appears to mediate replicative senescence as well as TGF-β-induced cellular senescence in non-transformed cells and that HPV E6/E7 targets Notch1 for inactivation to prevent senescence, revealing a tumor suppressor attribute of endogenous Notch1. In aggregate, cellular senescence checkpoint functions may influence dichotomous Notch activities in the neoplastic context. PMID:24931169

  20. Cellular senescence checkpoint function determines differential Notch1-dependent oncogenic and tumor-suppressor activities.

    PubMed

    Kagawa, S; Natsuizaka, M; Whelan, K A; Facompre, N; Naganuma, S; Ohashi, S; Kinugasa, H; Egloff, A M; Basu, D; Gimotty, P A; Klein-Szanto, A J; Bass, A J; Wong, K-K; Diehl, J A; Rustgi, A K; Nakagawa, H

    2015-04-30

    Notch activity regulates tumor biology in a context-dependent and complex manner. Notch may act as an oncogene or a tumor-suppressor gene even within the same tumor type. Recently, Notch signaling has been implicated in cellular senescence. Yet, it remains unclear as to how cellular senescence checkpoint functions may interact with Notch-mediated oncogenic and tumor-suppressor activities. Herein, we used genetically engineered human esophageal keratinocytes and esophageal squamous cell carcinoma cells to delineate the functional consequences of Notch activation and inhibition along with pharmacological intervention and RNA interference experiments. When expressed in a tetracycline-inducible manner, the ectopically expressed activated form of Notch1 (ICN1) displayed oncogene-like characteristics inducing cellular senescence corroborated by the induction of G0/G1 cell-cycle arrest, Rb dephosphorylation, flat and enlarged cell morphology and senescence-associated β-galactosidase activity. Notch-induced senescence involves canonical CSL/RBPJ-dependent transcriptional activity and the p16(INK4A)-Rb pathway. Loss of p16(INK4A) or the presence of human papilloma virus (HPV) E6/E7 oncogene products not only prevented ICN1 from inducing senescence but permitted ICN1 to facilitate anchorage-independent colony formation and xenograft tumor growth with increased cell proliferation and reduced squamous-cell differentiation. Moreover, Notch1 appears to mediate replicative senescence as well as transforming growth factor-β-induced cellular senescence in non-transformed cells and that HPV E6/E7 targets Notch1 for inactivation to prevent senescence, revealing a tumor-suppressor attribute of endogenous Notch1. In aggregate, cellular senescence checkpoint functions may influence dichotomous Notch activities in the neoplastic context.

  1. Haploinsufficiency of the NOTCH1 Receptor as a Cause of Adams-Oliver Syndrome with Variable Cardiac Anomalies

    PubMed Central

    Southgate, Laura; Sukalo, Maja; Karountzos, Anastasios S.V.; Taylor, Edward J.; Collinson, Claire S.; Ruddy, Deborah; Snape, Katie M.; Dallapiccola, Bruno; Joss, Shelagh; Brancati, Francesco; Digilio, M. Cristina; Graul-Neumann, Luitgard M.; Salviati, Leonardo; Coerdt, Wiltrud; Jacquemin, Emmanuel; Wuyts, Wim; Zenker, Martin

    2015-01-01

    Background Adams-Oliver syndrome (AOS) is a rare disorder characterized by congenital limb defects and scalp cutis aplasia. In a proportion of cases, notable cardiac involvement is also apparent. Despite recent advances in the understanding of the genetic basis of AOS, for the majority of affected subjects the underlying molecular defect remains unresolved. This study aimed to identify novel genetic determinants of AOS. Methods and Results Whole-exome sequencing was performed for 12 probands, each with a clinical diagnosis of AOS. Analyses led to the identification of novel heterozygous truncating NOTCH1 mutations (c.1649dupA and c.6049_6050delTC) in two kindreds in which AOS was segregating as an autosomal dominant trait. Screening a cohort of 52 unrelated AOS subjects, we detected 8 additional unique NOTCH1 mutations, including three de novo amino-acid substitutions, all within the ligand-binding domain. Congenital heart anomalies were noted in 47% (8/17) of NOTCH1-positive probands and affected family members. In leucocyte-derived RNA from subjects harboring NOTCH1 extracellular domain mutations, we observed significant reduction of NOTCH1 expression, suggesting instability and degradation of mutant mRNA transcripts by the cellular machinery. Transient transfection of mutagenized NOTCH1 missense constructs also revealed significant reduction in gene expression. Mutant NOTCH1 expression was associated with down-regulation of the Notch target genes HEY1 and HES1, indicating that NOTCH1-related AOS arises through dysregulation of the Notch signaling pathway. Conclusions These findings highlight a key role for NOTCH1 across a range of developmental anomalies that include cardiac defects, and implicate NOTCH1 haploinsufficiency as a likely molecular mechanism for this group of disorders. PMID:25963545

  2. Targeted polymeric nanoparticles for cancer gene therapy

    PubMed Central

    Kim, Jayoung; Wilson, David R.; Zamboni, Camila G.; Green, Jordan J.

    2015-01-01

    In this article, advances in designing polymeric nanoparticles for targeted cancer gene therapy are reviewed. Characterization and evaluation of biomaterials, targeting ligands, and transcriptional elements are each discussed. Advances in biomaterials have driven improvements to nanoparticle stability and tissue targeting, conjugation of ligands to the surface of polymeric nanoparticles enable binding to specific cancer cells, and the design of transcriptional elements has enabled selective DNA expression specific to the cancer cells. Together, these features have improved the performance of polymeric nanoparticles as targeted non-viral gene delivery vectors to treat cancer. As polymeric nanoparticles can be designed to be biodegradable, non-toxic, and to have reduced immunogenicity and tumorigenicity compared to viral platforms, they have significant potential for clinical use. Results of polymeric gene therapy in clinical trials and future directions for the engineering of nanoparticle systems for targeted cancer gene therapy are also presented. PMID:26061296

  3. Targeted polymeric nanoparticles for cancer gene therapy.

    PubMed

    Kim, Jayoung; Wilson, David R; Zamboni, Camila G; Green, Jordan J

    2015-01-01

    In this article, advances in designing polymeric nanoparticles for targeted cancer gene therapy are reviewed. Characterization and evaluation of biomaterials, targeting ligands, and transcriptional elements are each discussed. Advances in biomaterials have driven improvements to nanoparticle stability and tissue targeting, conjugation of ligands to the surface of polymeric nanoparticles enable binding to specific cancer cells, and the design of transcriptional elements has enabled selective DNA expression specific to the cancer cells. Together, these features have improved the performance of polymeric nanoparticles as targeted non-viral gene delivery vectors to treat cancer. As polymeric nanoparticles can be designed to be biodegradable, non-toxic, and to have reduced immunogenicity and tumorigenicity compared to viral platforms, they have significant potential for clinical use. Results of polymeric gene therapy in clinical trials and future directions for the engineering of nanoparticle systems for targeted cancer gene therapy are also presented.

  4. A novel mutation (C67Y)in the NOTCH3 gene in a Korean CADASIL patient.

    PubMed Central

    Moon, So-Young; Kim, Hahn-Young; Seok, Jung-Im; Kwon, Jae-Chul; Ki, Chang-Seok; Kim, Jong-Won; Suh, Yeon-Lim; Na, Duk L.

    2003-01-01

    We report a 52-yr-old Korean woman with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) whose diagnosis was confirmed by skin biopsy and the presence of a novel mutation in the NOTCH3 gene. The patient's clinical features were rather unusual in that 1) clinical presentations were only two episodes of stroke and mild dementia unaccompanied by mood disturbances or migraine, and 2) there was no family history. Brain MRI showed T2 hyperintensities in both temporal pole areas in line with the recent suggestion by O'Sullivan et al. that the abnormality could be a radiologic marker of CADASIL. FDG-PET also showed a hypometabolism in the temporal pole areas with an abnormal finding on MRI in addition to the hypometabolism in cortical and subcortical regions. We could learn from this case that CADASIL may be included in the differential diagnoses in patients with vascular dementia associated with a small vessel disease, even in the absence of a family history, especially when there are no known stroke risk factors and when the MRI shows T2 hyperintensity in the temporal pole regions. PMID:12589106

  5. Hair cell stereociliary bundle regeneration by espin gene transduction after aminoglycoside damage and hair cell induction by Notch inhibition.

    PubMed

    Taura, A; Taura, K; Koyama, Y; Yamamoto, N; Nakagawa, T; Ito, J; Ryan, A F

    2016-05-01

    Once inner ear hair cells (HCs) are damaged by drugs, noise or aging, their apical structures including the stereociliary arrays are frequently the first cellular feature to be lost. Although this can be followed by progressive loss of HC somata, a significant number of HC bodies often remain even after stereociliary loss. However, in the absence of stereocilia they are nonfunctional. HCs can sometimes be regenerated by Atoh1 transduction or Notch inhibition, but they also may lack stereociliary bundles. It is therefore important to develop methods for the regeneration of stereocilia, in order to achieve HC functional recovery. Espin is an actin-bundling protein known to participate in sterociliary elongation during development. We evaluated stereociliary array regeneration in damaged vestibular sensory epithelia in tissue culture, using viral vector transduction of two espin isoforms. Utricular HCs were damaged with aminoglycosides. The utricles were then treated with a γ-secretase inhibitor, followed by espin or control transduction and histochemistry. Although γ-secretase inhibition increased the number of HCs, few had stereociliary arrays. In contrast, 46 h after espin1 transduction, a significant increase in hair-bundle-like structures was observed. These were confirmed to be immature stereociliary arrays by scanning electron microscopy. Increased uptake of FM1-43 uptake provided evidence of stereociliary function. Espin4 transduction had no effect. The results demonstrate that espin1 gene therapy can restore stereocilia on damaged or regenerated HCs.

  6. Hair cell stereociliary bundle regeneration by espin gene transduction after aminoglycoside damage and hair cell induction by Notch inhibition

    PubMed Central

    Taura, Akiko; Taura, Kojiro; Koyama, Yukinori; Yamamoto, Norio; Nakagawa, Takayuki; Ito, Juichi; Ryan, Allen F.

    2015-01-01

    Once inner ear hair cells (HCs) are damaged by drugs, noise or aging, their apical structures including the stereociliary arrays are frequently the first cellular feature to be lost. While this can be followed by progressive loss of HC somata, a significant number of HC bodies often remain even after stereociliary loss. However, in the absence of stereocilia they are nonfunctional. HCs can sometimes be regenerated by Atoh1 transduction or Notch inhibition, but they also may lack stereociliary bundles. It is therefore important to develop methods for the regeneration of stereocilia, in order to achieve HC functional recovery. Espin is an actin bundling protein known to participate in sterociliary elongation during development. We evaluated stereociliary array regeneration in damaged vestibular sensory epithelia in tissue culture, using viral vector transduction of two espin isoforms. Utricular HCs were damaged with aminoglycosides. The utricles were then treated with a γ-secretase inhibitor, followed by espin or control transduction and histochemistry. While γ-secretase inhibition increased the number of HCs, few had stereociliary arrays. In contrast, 46 hrs after espin1 transduction, a significant increase in hair-bundle-like structures was observed. These were confirmed to be immature stereociliary arrays by scanning electron microscopy. Increased uptake of FM1–43 uptake provided evidence of stereociliary function. Espin4 transduction had no effect. The results demonstrate that espin1 gene therapy can restore stereocilia on damaged or regenerated HCs. PMID:26886463

  7. Targeting tumor suppressor genes for cancer therapy.

    PubMed

    Liu, Yunhua; Hu, Xiaoxiao; Han, Cecil; Wang, Liana; Zhang, Xinna; He, Xiaoming; Lu, Xiongbin

    2015-12-01

    Cancer drugs are broadly classified into two categories: cytotoxic chemotherapies and targeted therapies that specifically modulate the activity of one or more proteins involved in cancer. Major advances have been achieved in targeted cancer therapies in the past few decades, which is ascribed to the increasing understanding of molecular mechanisms for cancer initiation and progression. Consequently, monoclonal antibodies and small molecules have been developed to interfere with a specific molecular oncogenic target. Targeting gain-of-function mutations, in general, has been productive. However, it has been a major challenge to use standard pharmacologic approaches to target loss-of-function mutations of tumor suppressor genes. Novel approaches, including synthetic lethality and collateral vulnerability screens, are now being developed to target gene defects in p53, PTEN, and BRCA1/2. Here, we review and summarize the recent findings in cancer genomics, drug development, and molecular cancer biology, which show promise in targeting tumor suppressors in cancer therapeutics.

  8. Approaches for gene targeting and targeted gene expression in plants.

    PubMed

    Husaini, Amjad Masood; Rashid, Zerka; Mir, Reyaz-ul Rouf; Aquil, Bushra

    2011-01-01

    Transgenic science and technology are fundamental to state-of-the-art plant molecular genetics and crop improvement. The new generation of technology endeavors to introduce genes 'stably' into 'site-specific' locations and in 'single copy' without the integration of extraneous vector 'backbone' sequences or selectable markers and with a 'predictable and consistent' expression. Several similar strategies and technologies, which can push the development of 'smart' genetically modified plants with desirable attributes, as well as enhance their consumer acceptability, are discussed in this review.

  9. Reduced Notch signalling leads to postnatal skeletal muscle hypertrophy in Pofut1cax/cax mice.

    PubMed

    Al Jaam, Bilal; Heu, Katy; Pennarubia, Florian; Segelle, Alexandre; Magnol, Laetitia; Germot, Agnès; Legardinier, Sébastien; Blanquet, Véronique; Maftah, Abderrahman

    2016-09-01

    Postnatal skeletal muscle growth results from the activation of satellite cells and/or an increase in protein synthesis. The Notch signalling pathway maintains satellite cells in a quiescent state, and once activated, sustains their proliferation and commitment towards differentiation. In mammals, POFUT1-mediated O-fucosylation regulates the interactions between NOTCH receptors and ligands of the DELTA/JAGGED family, thus initiating the activation of canonical Notch signalling. Here, we analysed the consequences of downregulated expression of the Pofut1 gene on postnatal muscle growth in mutant Pofut1(cax/cax) (cax, compact axial skeleton) mice and differentiation of their satellite cell-derived myoblasts (SCDMs). Pofut1(cax/cax) mice exhibited muscle hypertrophy, no hyperplasia and a decrease in satellite cell numbers compared with wild-type C3H mice. In agreement with these observations, Pofut1(cax/cax) SCDMs differentiated earlier concomitant with reduced Pax7 expression and decrease in PAX7(+)/MYOD(-) progenitor cells. In vitro binding assays showed a reduced interaction of DELTA-LIKE 1 ligand (DLL1) with NOTCH receptors expressed at the cell surface of SCDMs, leading to a decreased Notch signalling as seen by the quantification of cleaved NICD and Notch target genes. These results demonstrated that POFUT1-mediated O-fucosylation of NOTCH receptors regulates myogenic cell differentiation and affects postnatal muscle growth in mice. PMID:27628322

  10. Reduced Notch signalling leads to postnatal skeletal muscle hypertrophy in Pofut1cax/cax mice

    PubMed Central

    Al Jaam, Bilal; Heu, Katy; Pennarubia, Florian; Segelle, Alexandre; Magnol, Laetitia; Germot, Agnès; Blanquet, Véronique; Maftah, Abderrahman

    2016-01-01

    Postnatal skeletal muscle growth results from the activation of satellite cells and/or an increase in protein synthesis. The Notch signalling pathway maintains satellite cells in a quiescent state, and once activated, sustains their proliferation and commitment towards differentiation. In mammals, POFUT1-mediated O-fucosylation regulates the interactions between NOTCH receptors and ligands of the DELTA/JAGGED family, thus initiating the activation of canonical Notch signalling. Here, we analysed the consequences of downregulated expression of the Pofut1 gene on postnatal muscle growth in mutant Pofut1cax/cax (cax, compact axial skeleton) mice and differentiation of their satellite cell-derived myoblasts (SCDMs). Pofut1cax/cax mice exhibited muscle hypertrophy, no hyperplasia and a decrease in satellite cell numbers compared with wild-type C3H mice. In agreement with these observations, Pofut1cax/cax SCDMs differentiated earlier concomitant with reduced Pax7 expression and decrease in PAX7+/MYOD− progenitor cells. In vitro binding assays showed a reduced interaction of DELTA-LIKE 1 ligand (DLL1) with NOTCH receptors expressed at the cell surface of SCDMs, leading to a decreased Notch signalling as seen by the quantification of cleaved NICD and Notch target genes. These results demonstrated that POFUT1-mediated O-fucosylation of NOTCH receptors regulates myogenic cell differentiation and affects postnatal muscle growth in mice. PMID:27628322

  11. Requirement of HDAC6 for activation of Notch1 by TGF-β1

    PubMed Central

    Deskin, Brian; Lasky, Joseph; Zhuang, Yan; Shan, Bin

    2016-01-01

    TGF-β1 is enriched in the tumor microenvironment and acts as a key inducer of epithelial to mesenchymal transition (EMT) in lung cancer. The NOTCH signaling pathway is conserved across species and is an essential pathway for development, cell differentiation, and cancer biology. Dysregulation of Notch signaling is a common feature of non-small cell lung cancer (NSCLC) and is correlated with poor prognosis. Crosstalk exists between the NOTCH and TGF-β signaling pathways in EMT. Herein we report that histone deacetylase 6 (HDAC6) modulates TGF-β1-mediated activation of the Notch pathway. HDAC6, a primarily cytoplasmic deacetylase, mediates TGF-β1-induced EMT in human lung cancer cells. Inhibition of HDAC6 with a small molecule inhibitor, namely tubacin or with siRNA attenuated TGF-β1-induced Notch-1 signaling. We show that TGFβ-1-induced EMT is accompanied by rapid HDAC6-dependent deacetylation of heat shock protein 90 (HSP90). Consistently, inhibition of HSP90 with its small molecule inhibitor 17AAG attenuated expression of TGF-β1-induced Notch-1 target genes, HEY-1 and HES-1. These findings reveal a novel function of HDAC6 in EMT via mediating the TGF-β-Notch signaling cascade, and support HDAC6 as a key regulator of TGFβ-induced EMT in NSCLC. This work suggests that HDAC6 may be an attractive therapeutic target against tumor progression and metastasis. PMID:27499032

  12. Gene Targeting in Mice: a Review

    PubMed Central

    Bouabe, Hicham; Okkenhaug, Klaus

    2015-01-01

    Summary The ability to introduce DNA sequences (e.g. genes) of interest into the germline genome has rendered the mouse a powerful and indispensable experimental model in fundamental and medical research. The DNA sequences can be integrated into the genome randomly or into a specific locus by homologous recombination, in order to: (i) delete or insert mutations into genes of interest to determine their function, (ii) introduce human genes into the genome of mice to generate animal models enabling study of human-specific genes and diseases, e.g. mice susceptible to infections by human-specific pathogens of interest, (iii) introduce individual genes or genomes of pathogens (such as viruses) in order to examine the contributions of such genes to the pathogenesis of the parent pathogens, (iv) and last but not least introduce reporter genes that allow monitoring in vivo or ex vivo the expression of genes of interest. Furthermore, the use of recombination systems, such as Cre/loxP or FRT/FLP, enables conditional induction or suppression of gene expression of interest in a restricted period of mouse’s lifetime, in a particular cell type, or in a specific tissue. In this review, we will give an updated summary of the gene targeting technology and discuss some important considerations in the design of gene-targeted mice. PMID:23996268

  13. BEND6 is a nuclear antagonist of Notch signaling during self-renewal of neural stem cells

    PubMed Central

    Dai, Qi; Andreu-Agullo, Celia; Insolera, Ryan; Wong, Li Chin; Shi, Song-Hai; Lai, Eric C.

    2013-01-01

    The activity of the Notch pathway revolves around a CSL-class transcription factor, which recruits distinct complexes that activate or repress target gene expression. The co-activator complex is deeply conserved and includes the cleaved Notch intracellular domain (NICD) and Mastermind. By contrast, numerous CSL co-repressor proteins have been identified, and these are mostly different between invertebrate and vertebrate systems. In this study, we demonstrate that mammalian BEND6 is a neural BEN-solo factor that shares many functional attributes with Drosophila Insensitive, a co-repressor for the Drosophila CSL factor. BEND6 binds the mammalian CSL protein CBF1 and antagonizes Notch-dependent target activation. In addition, its association with Notch- and CBF1-regulated enhancers is promoted by CBF1 and antagonized by activated Notch. In utero electroporation experiments showed that ectopic BEND6 inhibited Notch-mediated self-renewal of neocortical neural stem cells and promoted neurogenesis. Conversely, knockdown of BEND6 increased NSC self-renewal in wild-type neocortex, and exhibited genetic interactions with gain and loss of Notch pathway activity. We recapitulated all of these findings in cultured neurospheres, in which overexpression and depletion of BEND6 caused reciprocal effects on neural stem cell renewal and neurogenesis. These data reveal a novel mammalian CSL co-repressor in the nervous system, and show that the Notch-inhibitory activity of certain BEN-solo proteins is conserved between flies and mammals. PMID:23571214

  14. Targeting gene therapy to cancer: a review.

    PubMed

    Dachs, G U; Dougherty, G J; Stratford, I J; Chaplin, D J

    1997-01-01

    In recent years the idea of using gene therapy as a modality in the treatment of diseases other than genetically inherited, monogenic disorders has taken root. This is particularly obvious in the field of oncology where currently more than 100 clinical trials have been approved worldwide. This report will summarize some of the exciting progress that has recently been made with respect to both targeting the delivery of potentially therapeutic genes to tumor sites and regulating their expression within the tumor microenvironment. In order to specifically target malignant cells while at the same time sparing normal tissue, cancer gene therapy will need to combine highly selective gene delivery with highly specific gene expression, specific gene product activity, and, possibly, specific drug activation. Although the efficient delivery of DNA to tumor sites remains a formidable task, progress has been made in recent years using both viral (retrovirus, adenovirus, adeno-associated virus) and nonviral (liposomes, gene gun, injection) methods. In this report emphasis will be placed on targeted rather than high-efficiency delivery, although those would need to be combined in the future for effective therapy. To date delivery has been targeted to tumor-specific and tissue-specific antigens, such as epithelial growth factor receptor, c-kit receptor, and folate receptor, and these will be described in some detail. To increase specificity and safety of gene therapy further, the expression of the therapeutic gene needs to be tightly controlled within the target tissue. Targeted gene expression has been analyzed using tissue-specific promoters (breast-, prostate-, and melanoma-specific promoters) and disease-specific promoters (carcinoembryonic antigen, HER-2/neu, Myc-Max response elements, DF3/MUC). Alternatively, expression could be regulated externally with the use of radiation-induced promoters or tetracycline-responsive elements. Another novel possibility that will be

  15. Inhibition of Notch signaling enhances transdifferentiation of the esophageal squamous epithelium towards a Barrett's-like metaplasia via KLF4.

    PubMed

    Vega, Maria E; Giroux, Véronique; Natsuizaka, Mitsuteru; Liu, Mingen; Klein-Szanto, Andres J; Stairs, Douglas B; Nakagawa, Hiroshi; Wang, Kenneth K; Wang, Timothy C; Lynch, John P; Rustgi, Anil K

    2014-01-01

    Barrett's esophagus (BE) is defined as an incomplete intestinal metaplasia characterized generally by the presence of columnar and goblet cells in the formerly stratified squamous epithelium of the esophagus. BE is known as a precursor for esophageal adenocarcinoma. Currently, the cell of origin for human BE has yet to be clearly identified. Therefore, we investigated the role of Notch signaling in the initiation of BE metaplasia. Affymetrix gene expression microarray revealed that BE samples express decreased levels of Notch receptors (NOTCH2 and NOTCH3) and one of the the ligands (JAG1). Furthermore, BE tissue microarray showed decreased expression of NOTCH1 and its downstream target HES1. Therefore, Notch signaling was inhibited in human esophageal epithelial cells by expression of dominant-negative-Mastermind-like (dnMAML), in concert with MYC and CDX1 overexpression. Cell transdifferentiation was then assessed by 3D organotypic culture and evaluation of BE-lineage specific gene expression. Notch inhibition promoted transdifferentiation of esophageal epithelial cells toward columnar-like cells as demonstrated by increased expression of columnar keratins (K8, K18, K19, K20) and glandular mucins (MUC2, MUC3B, MUC5B, MUC17) and decreased expression of squamous keratins (K5, K13, K14). In 3D culture, elongated cells were observed in the basal layer of the epithelium with Notch inhibition. Furthermore, we observed increased expression of KLF4, a potential driver of the changes observed by Notch inhibition. Interestingly, knockdown of KLF4 reversed the effects of Notch inhibition on BE-like metaplasia. Overall, Notch signaling inhibition promotes transdifferentiation of esophageal cells toward BE-like metaplasia in part via upregulation of KLF4. These results support a novel mechanism through which esophageal epithelial transdifferentiation promotes the evolution of BE.

  16. Functional redundancy of the Notch pathway in ovarian cancer cell lines

    PubMed Central

    Silva, Fernanda; Félix, Ana; Serpa, Jacinta

    2016-01-01

    Epithelial ovarian cancer is the most lethal gynecologic malignancy, despite advances in treatment. The most common histological type, high-grade ovarian serous carcinoma (OSC) is usually diagnosed at an advanced stage, and although these types of tumors frequently respond to surgery and platinum-based chemotherapy, they usually recur. Ovarian clear cell carcinoma (OCCC) is an unusual histological type, which is known to be intrinsically chemoresistant and is associated with poor prognosis in advanced stages. In recent years, genetic alterations and epigenetic modulation of signaling pathways have been reported in OSC and OCCC, including the overexpression of Notch pathway elements and histone deacetylases. Histone deacetylase inhibitors (HDACis), including vorinostat (suberoylanilide hydroxamic acid), alter the transcription of genes involved in cell growth, survival and apoptosis, and have become an attractive therapeutic approach. However, no previous work has addressed the effect of HDACis, and in particular vorinostat, on Notch signaling in ovarian cancer. Therefore, the present study aimed to investigate the modulation of the Notch pathway by vorinostat in ovarian cancer. Using immunofluorescence and quantitative polymerase chain reaction, the present results revealed that vorinostat activated the Notch pathway in OCCC and OSC cell lines, through different Notch ligands. In OCCC, the activation of the Notch pathway appeared to occur through Delta-like (Dll) ligands 1, 2 and 3, whereas in OSC Dll1 and Jagged 1 and 2 ligands were involved. The activation of the Notch pathway by vorinostat, in OCCC and OSC cell lines, culminated in the increased expression of the same downstream transcription factors, hairy enhancer of split (Hes) 1 and 5, and Hes-related proteins 1 and 2. In conclusion, vorinostat modulates the expression of several downstream targets of the Notch pathway and independent Notch receptors and ligands that are expressed in OSC and OCCC. This

  17. Cisplatin selects for stem-like cells in osteosarcoma by activating Notch signaling

    PubMed Central

    Yang, Jian; Gao, Tian; Simões, Bruno M.; Eyre, Rachel; Guo, Weichun; Clarke, Robert B.

    2016-01-01

    Notch signaling regulates normal stem cells and is also thought to regulate cancer stem cells (CSCs). Recent data indicate that Notch signaling plays a role in the development and progression of osteosarcoma, however the regulation of Notch in chemo-resistant stem-like cells has not yet been fully elucidated. In this study we generated cisplatin-resistant osteosarcoma cells by treating them with sub-lethal dose of cisplatin, sufficient to induce DNA damage responses. Cisplatin-resistant osteosarcoma cells exhibited lower proliferation, enhanced spheroid formation and more mesenchymal characteristics than cisplatin-sensitive cells, were enriched for Stro-1+/CD117+ cells and showed increased expression of stem cell-related genes. A similar effect was observed in vivo, and in addition in vivo tumorigenicity was enhanced during serial transplantation. Using several publicly available datasets, we identified that Notch expression was closely associated with osteosarcoma stem cells and chemotherapy resistance. We confirmed that cisplatin-induced enrichment of osteosarcoma stem cells was mediated through Notch signaling in vitro, and immunohistochemistry showed that cleaved Notch1 (NICD1) positive cells were significantly increased in a relapsed xenograft which had received cisplatin treatment. Furthermore, pretreatment with a γ-secretase inhibitor (GSI) to prevent Notch signalling inhibited cisplatin-enriched osteosarcoma stem cell activity in vitro, including Stro-1+/CD117+ double positive cells and spheroid formation capacity. The Notch inhibitor DAPT also prevented tumor recurrence in resistant xenograft tumors. Overall, our results show that cisplatin induces the enrichment of osteosarcoma stem-like cells through Notch signaling, and targeted inactivation of Notch may be useful for the elimination of CSCs and overcoming drug resistance. PMID:27102300

  18. Notch signalling drives bone marrow stromal cell-mediated chemoresistance in acute myeloid leukemia

    PubMed Central

    Kamga, Paul Takam; Bassi, Giulio; Cassaro, Adriana; Midolo, Martina; Di Trapani, Mariano; Gatti, Alessandro; Carusone, Roberta; Resci, Federica; Perbellini, Omar; Gottardi, Michele; Bonifacio, Massimiliano; Kamdje, Armel Hervé Nwabo; Ambrosetti, Achille; Krampera, Mauro

    2016-01-01

    Both preclinical and clinical investigations suggest that Notch signalling is critical for the development of many cancers and for their response to chemotherapy. We previously showed that Notch inhibition abrogates stromal-induced chemoresistance in lymphoid neoplasms. However, the role of Notch in acute myeloid leukemia (AML) and its contribution to the crosstalk between leukemia cells and bone marrow stromal cells remain controversial. Thus, we evaluated the role of the Notch pathway in the proliferation, survival and chemoresistance of AML cells in co-culture with bone marrow mesenchymal stromal cells expanded from both healthy donors (hBM-MSCs) and AML patients (hBM-MSCs*). As compared to hBM-MSCs, hBM-MSCs* showed higher level of Notch1, Jagged1 as well as the main Notch target gene HES1. Notably, hBM-MSCs* induced expression and activation of Notch signalling in AML cells, supporting AML proliferation and being more efficientin inducing AML chemoresistance than hBM-MSCs*. Pharmacological inhibition of Notch using combinations of Notch receptor-blocking antibodies or gamma-secretase inhibitors (GSIs), in presence of chemotherapeutic agents, significant lowered the supportive effect of hBM-MSCs and hBM-MSCs* towards AML cells, by activating apoptotic cascade and reducing protein level of STAT3, AKT and NF-κB. These results suggest that Notch signalling inhibition, by overcoming the stromal-mediated promotion of chemoresistance,may represent a potential therapeutic targetnot only for lymphoid neoplasms, but also for AML. PMID:26967055

  19. Notch3 and Hey-1 as Prognostic Biomarkers in Pancreatic Adenocarcinoma

    PubMed Central

    Mann, Christopher D.; Bastianpillai, Christopher; Neal, Christopher P.; Masood, Muhammad M.; Jones, Donald J. L.; Teichert, Friederike; Singh, Rajinder; Karpova, Elena; Berry, David P.; Manson, Margaret M.

    2012-01-01

    In order to achieve a better outcome for pancreatic cancer patients, reliable biomarkers are required which allow for improved diagnosis. These may emanate from a more detailed molecular understanding of the aggressive nature of this disease. Having previously reported that Notch3 activation appeared to be associated with more aggressive disease, we have now examined components of this pathway (Notch1, Notch3, Notch4, HES-1, HEY-1) in more detail in resectable (n = 42) and non-resectable (n = 50) tumours compared to uninvolved pancreas. All three Notch family members were significantly elevated in tumour tissue, compared to uninvolved pancreas, with expression maintained within matched lymph node metastases. Furthermore, significantly higher nuclear expression of Notch1, -3 and -4, HES-1, and HEY-1 (all p≤0.001) was noted in locally advanced and metastatic tumours compared to resectable cancers. In survival analyses, nuclear Notch3 and HEY-1 expression were significantly associated with reduced overall and disease-free survival following tumour resection with curative intent, with nuclear HEY-1 maintaining independent prognostic significance for both outcomes on multivariate analysis. These data further support a central role for Notch signalling in pancreatic cancer and suggest that nuclear expression of Notch3 and its target gene, HEY-1, merit validation in biomarker panels for diagnosis, prognosis and treatment efficacy. A peptide fragment of Notch3 was detected in plasma from patients with inoperable pancreatic cancer, but due to wide inter-individual variation, mean levels were not significantly different compared to age-matched controls. PMID:23226563

  20. Functional redundancy of the Notch pathway in ovarian cancer cell lines

    PubMed Central

    Silva, Fernanda; Félix, Ana; Serpa, Jacinta

    2016-01-01

    Epithelial ovarian cancer is the most lethal gynecologic malignancy, despite advances in treatment. The most common histological type, high-grade ovarian serous carcinoma (OSC) is usually diagnosed at an advanced stage, and although these types of tumors frequently respond to surgery and platinum-based chemotherapy, they usually recur. Ovarian clear cell carcinoma (OCCC) is an unusual histological type, which is known to be intrinsically chemoresistant and is associated with poor prognosis in advanced stages. In recent years, genetic alterations and epigenetic modulation of signaling pathways have been reported in OSC and OCCC, including the overexpression of Notch pathway elements and histone deacetylases. Histone deacetylase inhibitors (HDACis), including vorinostat (suberoylanilide hydroxamic acid), alter the transcription of genes involved in cell growth, survival and apoptosis, and have become an attractive therapeutic approach. However, no previous work has addressed the effect of HDACis, and in particular vorinostat, on Notch signaling in ovarian cancer. Therefore, the present study aimed to investigate the modulation of the Notch pathway by vorinostat in ovarian cancer. Using immunofluorescence and quantitative polymerase chain reaction, the present results revealed that vorinostat activated the Notch pathway in OCCC and OSC cell lines, through different Notch ligands. In OCCC, the activation of the Notch pathway appeared to occur through Delta-like (Dll) ligands 1, 2 and 3, whereas in OSC Dll1 and Jagged 1 and 2 ligands were involved. The activation of the Notch pathway by vorinostat, in OCCC and OSC cell lines, culminated in the increased expression of the same downstream transcription factors, hairy enhancer of split (Hes) 1 and 5, and Hes-related proteins 1 and 2. In conclusion, vorinostat modulates the expression of several downstream targets of the Notch pathway and independent Notch receptors and ligands that are expressed in OSC and OCCC. This

  1. Gene Therapy and Targeted Toxins for Glioma

    PubMed Central

    Castro, Maria G.; Candolfi, Marianela; Kroeger, Kurt; King, Gwendalyn D.; Curtin, James F.; Yagiz, Kader; Mineharu, Yohei; Assi, Hikmat; Wibowo, Mia; Muhammad, AKM Ghulam; Foulad, David; Puntel, Mariana; Lowenstein, Pedro R.

    2011-01-01

    The most common primary brain tumor in adults is glioblastoma. These tumors are highly invasive and aggressive with a mean survival time of nine to twelve months from diagnosis to death. Current treatment modalities are unable to significantly prolong survival in patients diagnosed with glioblastoma. As such, glioma is an attractive target for developing novel therapeutic approaches utilizing gene therapy. This review will examine the available preclinical models for glioma including xenographs, syngeneic and genetic models. Several promising therapeutic targets are currently being pursued in pre-clinical investigations. These targets will be reviewed by mechanism of action, i.e., conditional cytotoxic, targeted toxins, oncolytic viruses, tumor suppressors/oncogenes, and immune stimulatory approaches. Preclinical gene therapy paradigms aim to determine which strategies will provide rapid tumor regression and long-term protection from recurrence. While a wide range of potential targets are being investigated preclinically, only the most efficacious are further transitioned into clinical trial paradigms. Clinical trials reported to date are summarized including results from conditionally cytotoxic, targeted toxins, oncolytic viruses and oncogene targeting approaches. Clinical trial results have not been as robust as preclinical models predicted; this could be due to the limitations of the GBM models employed. Once this is addressed, and we develop effective gene therapies in models that better replicate the clinical scenario, gene therapy will provide a powerful approach to treat and manage brain tumors. PMID:21453286

  2. Targeting of Synthetic Gene Delivery Systems

    PubMed Central

    2003-01-01

    Safe, efficient, and specific delivery of therapeutic genes remains an important bottleneck for the development of gene therapy. Synthetic, nonviral systems have a unique pharmaceutical profile with potential advantages for certain applications. Targeting of the synthetic vector improves the specificity of gene medicines through a modulation of the carriers' biodistribution, thus creating a dose differential between healthy tissue and the target site. The biodistribution of current carrier systems is being influenced to a large extent by intrinsic physicochemical characteristics, such as charge and size. Consequently, such nonspecific interactions can interfere with specific targeting, for example, by ligands. Therefore, a carrier complex should ideally be inert, that is, free from intrinsic properties that would bias its distribution away from the target site. Strategies such as coating of DNA carrier complexes with hydrophilic polymers have been used to mask some of these intrinsic targeting effects and avoid nonspecific interactions. Preexisting endogenous ligand-receptor interactions have frequently been used for targeting to certain cell types or tumours. Recently exogenous ligands have been derived from microorganisms or, like antibodies or phage-derived peptides, developed de novo. In animal models, such synthetic vectors have targeted remote sites such as a tumour. Furthermore, the therapeutic proof of the concept has been demonstrated for fitting combinations of synthetic vectors and therapeutic gene. PMID:12721518

  3. Alterations in Notch signalling in skeletal muscles from mdx and dko dystrophic mice and patients with Duchenne muscular dystrophy.

    PubMed

    Church, Jarrod E; Trieu, Jennifer; Chee, Annabel; Naim, Timur; Gehrig, Stefan M; Lamon, Séverine; Angelini, Corrado; Russell, Aaron P; Lynch, Gordon S

    2014-04-01

    New Findings What is the central question of this study? The Notch signalling pathway plays an important role in muscle regeneration, and activation of the pathway has been shown to enhance muscle regeneration in aged mice. It is unknown whether Notch activation will have a similarly beneficial effect on muscle regeneration in the context of Duchenne muscular dystrophy (DMD). What is the main finding and its importance? Although expression of Notch signalling components is altered in both mouse models of DMD and in human DMD patients, activation of the Notch signalling pathway does not confer any functional benefit on muscles from dystrophic mice, suggesting that other signalling pathways may be more fruitful targets for manipulation in treating DMD. Abstract In Duchenne muscular dystrophy (DMD), muscle damage and impaired regeneration lead to progressive muscle wasting, weakness and premature death. The Notch signalling pathway represents a central regulator of gene expression and is critical for cellular proliferation, differentiation and apoptotic signalling during all stages of embryonic muscle development. Notch activation improves muscle regeneration in aged mice, but its potential to restore regeneration and function in muscular dystrophy is unknown. We performed a comprehensive examination of several genes involved in Notch signalling in muscles from dystrophin-deficient mdx and dko (utrophin- and dystrophin-null) mice and DMD patients. A reduction of Notch1 and Hes1 mRNA in tibialis anterior muscles of dko mice and quadriceps muscles of DMD patients and a reduction of Hes1 mRNA in the diaphragm of the mdx mice were observed, with other targets being inconsistent across species. Activation and inhibition of Notch signalling, followed by measures of muscle regeneration and function, were performed in the mouse models of DMD. Notch activation had no effect on functional regeneration in C57BL/10, mdx or dko mice. Notch inhibition significantly depressed the

  4. Hepatic Notch1 deletion predisposes to diabetes and steatosis via glucose-6-phosphatase and perilipin-5 upregulation.

    PubMed

    Bernsmeier, Christine; Dill, Michael T; Provenzano, Angela; Makowska, Zuzanna; Krol, Ilona; Muscogiuri, Giovanna; Semela, David; Tornillo, Luigi; Marra, Fabio; Heim, Markus H; Duong, François H T

    2016-09-01

    Notch signaling pathways have recently been implicated in the pathogenesis of metabolic diseases. However, the role of hepatic Notch signaling in glucose and lipid metabolism remains unclear and needs further investigation as it might be a candidate therapeutic target in metabolic diseases such as nonalcoholic steatohepatitis (NASH) and nonalcoholic fatty liver disease (NAFLD). We used hepatocyte-specific Notch1 knockout (KO) mice and liver biopsies from NASH and NAFLD patients to analyze the role of Notch1 in glucose and lipid metabolism. Hepatocyte-specific Notch1 KO mice were fed with a high fat diet (HFD) or a regular diet (RD). We assessed the metabolic phenotype, glucose and insulin tolerance tests, and liver histology. Hepatic mRNA expression was profiled by Affymetrix Mouse Gene arrays and validated by quantitative reverse transcription PCR (qPCR). Akt phosphorylation was visualized by immunoblotting. Gene expression was analyzed in liver biopsies from NASH, NAFLD, and control patients by qPCR. We found that Notch1 KO mice had elevated fasting glucose. Gene expression analysis showed an upregulation of glucose-6-phosphatase, involved in the final step of gluconeogenesis and glucose release from glycogenolysis, and perilipin-5, a regulator of hepatic lipid accumulation. When fed with an HFD KO mice developed overt diabetes and hepatic steatosis. Akt was highly phosphorylated in KO animals and the Foxo1 target gene expression was altered. Accordingly, a reduction in Notch1 and increase in glucose-6-phosphatase and perilipin-5 expression was observed in liver biopsies from NAFLD/NASH compared with controls. Notch1 is a regulator of hepatic glucose and lipid homeostasis. Hepatic impairment of Notch1 expression may be involved in the pathogenesis of human NAFLD/NASH. PMID:27428080

  5. Therapeutic NOTCH3 cysteine correction in CADASIL using exon skipping: in vitro proof of concept.

    PubMed

    Rutten, Julie W; Dauwerse, Hans G; Peters, Dorien J M; Goldfarb, Andrew; Venselaar, Hanka; Haffner, Christof; van Ommen, Gert-Jan B; Aartsma-Rus, Annemieke M; Lesnik Oberstein, Saskia A J

    2016-04-01

    Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, or CADASIL, is a hereditary cerebral small vessel disease caused by characteristic cysteine altering missense mutations in the NOTCH3 gene. NOTCH3 mutations in CADASIL result in an uneven number of cysteine residues in one of the 34 epidermal growth factor like-repeat (EGFr) domains of the NOTCH3 protein. The consequence of an unpaired cysteine residue in an EGFr domain is an increased multimerization tendency of mutant NOTCH3, leading to toxic accumulation of the protein in the (cerebro)vasculature, and ultimately reduced cerebral blood flow, recurrent stroke and vascular dementia. There is no therapy to delay or alleviate symptoms in CADASIL. We hypothesized that exclusion of the mutant EGFr domain from NOTCH3 would abolish the detrimental effect of the unpaired cysteine and thus prevent toxic NOTCH3 accumulation and the negative cascade of events leading to CADASIL. To accomplish this NOTCH3 cysteine correction by EGFr domain exclusion, we used pre-mRNA antisense-mediated skipping of specific NOTCH3 exons. Selection of these exons was achieved using in silico studies and based on the criterion that skipping of a particular exon or exon pair would modulate the protein in such a way that the mutant EGFr domain is eliminated, without otherwise corrupting NOTCH3 structure and function. Remarkably, we found that this strategy closely mimics evolutionary events, where the elimination and fusion of NOTCH EGFr domains led to the generation of four functional NOTCH homologues. We modelled a selection of exon skip strategies using cDNA constructs and show that the skip proteins retain normal protein processing, can bind ligand and be activated by ligand. We then determined the technical feasibility of targeted NOTCH3 exon skipping, by designing antisense oligonucleotides targeting exons 2-3, 4-5 and 6, which together harbour the majority of distinct CADASIL-causing mutations

  6. Hippo signaling is required for Notch-dependent smooth muscle differentiation of neural crest

    PubMed Central

    Manderfield, Lauren J.; Aghajanian, Haig; Engleka, Kurt A.; Lim, Lillian Y.; Liu, Feiyan; Jain, Rajan; Li, Li; Olson, Eric N.; Epstein, Jonathan A.

    2015-01-01

    Notch signaling has well-defined roles in the assembly of arterial walls and in the development of the endothelium and smooth muscle of the vasculature. Hippo signaling regulates cellular growth in many tissues, and contributes to regulation of organ size, in addition to other functions. Here, we show that the Notch and Hippo pathways converge to regulate smooth muscle differentiation of the neural crest, which is crucial for normal development of the aortic arch arteries and cranial vasculature during embryonic development. Neural crest-specific deletion of the Hippo effectors Yap and Taz produces neural crest precursors that migrate normally, but fail to produce vascular smooth muscle, and Notch target genes such as Jagged1 fail to activate normally. We show that Yap is normally recruited to a tissue-specific Jagged1 enhancer by directly interacting with the Notch intracellular domain (NICD). The Yap-NICD complex is recruited to chromatin by the DNA-binding protein Rbp-J in a Tead-independent fashion. Thus, Hippo signaling can modulate Notch signaling outputs, and components of the Hippo and Notch pathways physically interact. Convergence of Hippo and Notch pathways by the mechanisms described here might be relevant for the function of these signaling cascades in many tissues and in diseases such as cancer. PMID:26253400

  7. Endothelial sirtuin 1 inactivation enhances capillary rarefaction and fibrosis following kidney injury through Notch activation.

    PubMed

    Kida, Yujiro; Zullo, Joseph A; Goligorsky, Michael S

    2016-09-23

    Peritubular capillary (PTC) rarefaction along with tissue fibrosis is a hallmark of chronic kidney disease (CKD). However, molecular mechanisms of PTC loss have been poorly understood. Previous studies have demonstrated that functional loss of endothelial sirtuin 1 (SIRT1) impairs angiogenesis during development and tissue damage. Here, we found that endothelial SIRT1 dysfunction causes activation of endothelial Notch1 signaling, which leads to PTC rarefaction and fibrosis following kidney injury. In mice lacking functional SIRT1 in the endothelium (Sirt1 mutant), kidney injury enhanced apoptosis and senescence of PTC endothelial cells with impaired endothelial proliferation and expanded myofibroblast population and collagen deposition. Compared to wild-type kidneys, Sirt1 mutant kidneys up-regulated expression of Delta-like 4 (DLL4, a potent Notch1 ligand), Hey1 and Hes1 (Notch target genes), and Notch intracellular domain-1 (NICD1, active form of Notch1) in microvascular endothelial cells (MVECs) post-injury. Sirt1 mutant primary kidney MVECs reduced motility and vascular assembly and enhanced senescence compared to wild-type kidney MVECs. This difference in the phenotype was negated with Notch inhibition. Concurrent stimulation of DLL4 and transforming growth factor (TGF)-β1 increased trans-differentiation of primary kidney pericytes into myofibroblast more than TGF-β1 treatment alone. Collectively, these results indicate that endothelial SIRT1 counteracts PTC rarefaction by repression of Notch1 signaling and antagonizes fibrosis via suppression of endothelial DLL4 expression.

  8. Aberrant Notch signaling in glioblastoma stem cells contributes to tumor recurrence and invasion.

    PubMed

    Yu, Jian-Bo; Jiang, Hao; Zhan, Ren-Ya

    2016-08-01

    Upregulation of the Notch signaling pathway in cancer stem cells and side population (SP) cells has a major role in maintenance, self-renewal and chemoresistance. The present study isolated a cancer stem cell-like SP accounting for 4.1% of a glioblastoma cell population using a Hoechst 33342 dye exclusion assay. In this glioblastoma SP, the expression of of Notch1 signaling proteins Notch1 intracellular domain and Hes‑1 was markedly upregulated. Furthermore, knockdown of Notch1 by RNA interference significantly diminished the neurosphere formation ability, self‑renewal and chemoresistance of the SP cells. In addition, the expression of the stem‑cell surface genes Oct‑4, Sox2 and Nanog in SP cells was significantly reduced and the sensitivity to the SP cells to chemotherapeutics was enhanced following Notch1 knockdown. In conclusion, the results of the present study suggested that upregulation of Notch1 is involved in the chemotherapy resistance and tumor recurrence of glioblastoma. Hence, the development of novel anti‑cancer drugs targeting the Notch1 signaling pathway may be a promising strategy for curing glioblastoma. PMID:27315154

  9. Angiopoietin-like proteins stimulate HSPC development through interaction with notch receptor signaling

    PubMed Central

    Lin, Michelle I; Price, Emily N; Boatman, Sonja; Hagedorn, Elliott J; Trompouki, Eirini; Satishchandran, Sruthi; Carspecken, Charles W; Uong, Audrey; DiBiase, Anthony; Yang, Song; Canver, Matthew C; Dahlberg, Ann; Lu, Zhigang; Zhang, Cheng Cheng; Orkin, Stuart H; Bernstein, Irwin D; Aster, Jon C; White, Richard M; Zon, Leonard I

    2015-01-01

    Angiopoietin-like proteins (angptls) are capable of ex vivo expansion of mouse and human hematopoietic stem and progenitor cells (HSPCs). Despite this intriguing ability, their mechanism is unknown. In this study, we show that angptl2 overexpression is sufficient to expand definitive HSPCs in zebrafish embryos. Angptl1/2 are required for definitive hematopoiesis and vascular specification of the hemogenic endothelium. The loss-of-function phenotype is reminiscent of the notch mutant mindbomb (mib), and a strong genetic interaction occurs between angptls and notch. Overexpressing angptl2 rescues mib while overexpressing notch rescues angptl1/2 morphants. Gene expression studies in ANGPTL2-stimulated CD34+ cells showed a strong MYC activation signature and myc overexpression in angptl1/2 morphants or mib restored HSPCs formation. ANGPTL2 can increase NOTCH activation in cultured cells and ANGPTL receptor interacted with NOTCH to regulate NOTCH cleavage. Together our data provide insight to the angptl-mediated notch activation through receptor interaction and subsequent activation of myc targets. DOI: http://dx.doi.org/10.7554/eLife.05544.001 PMID:25714926

  10. Genetic variants of the NOTCH3 gene in the elderly and magnetic resonance imaging correlates of age-related cerebral small vessel disease

    PubMed Central

    Zeginigg, Marion; Wiltgen, Marco; Freudenberger, Paul; Petrovic, Katja; Cavalieri, Margherita; Gider, Pierre; Enzinger, Christian; Fornage, Myriam; Debette, Stephanie; Rotter, Jerome I.; Ikram, Mohammad A.; Launer, Lenore J.; Schmidt, Reinhold

    2011-01-01

    Cerebral small vessel disease-related brain lesions such as white matter lesions and lacunes are common findings of magnetic resonance imaging in the elderly. These lesions are thought to be major contributors to disability in old age, and risk factors that include age and hypertension have been established. The radiological, histopathologic and clinical phenotypes of age-related cerebral small vessel disease remarkably resemble autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy, which is caused by mutations in NOTCH3. We hypothesized that genetic variations in NOTCH3 also play a role in age-related cerebral small vessel disease. We directly sequenced all 33 exons, the promoter and 3′-untranslated region of NOTCH3 in 195 participants with either coalescent white matter lesions or lacunes and compared the results to 82 randomly selected participants with no focal changes on magnetic resonance images in the Austrian Stroke Prevention Study. We detected nine common and 33 rare single nucleotide polymorphisms, of which 20 were novel. All common single nucleotide polymorphisms were genotyped in the entire cohort (n = 888), and four of them, rs1043994, rs10404382, rs10423702 and rs1043997, were associated significantly with both the presence and progression of white matter lesions. The association was confined to hypertensives, a result which we replicated in the Cohorts for Heart and Ageing Research in Genomic Epidemiology Consortium on an independent sample of 4773 stroke-free hypertensive elderly individuals of European descent (P = 0.04). The 33 rare single nucleotide polymorphisms were scattered over the NOTCH3 gene with three being located in the promoter region, 24 in exons (18 non-synonymous), three in introns and three in the 3′-untranslated region. None of the single nucleotide polymorphisms affected a cysteine residue. Sorting Intolerant From Tolerant, PolyPhen2 analyses and protein structure simulation consistently

  11. Gene targeting in livestock: a preview.

    PubMed

    Clark, A J; Burl, S; Denning, C; Dickinson, P

    2000-01-01

    Until recently genetically modified livestock could only be generated by pronuclear injection. The discovery that animals can be cloned by nuclear transfer from cultured somatic cells means that it will now be possible to achieve gene targeting in these species. We discuss current developments in NT, the prospects and technical challenges for introducing targeted changes into the germline by this route, and the types of application for which this new technology will be used.

  12. The Histone Deacetylase Inhibitor Vaproic Acid Induces Cell Growth Arrest in Hepatocellular Carcinoma Cells via Suppressing Notch Signaling

    PubMed Central

    Sun, Guangchun; Mackey, Lily V.; Coy, David H.; Yu, Cui-Yun; Sun, Lichun

    2015-01-01

    Hepatocellular carcinoma (HCC) is a type of malignant cancer. Notch signaling is aberrantly expressed in HCC tissues with more evidence showing that this signaling plays a critical role in HCCs. In the present study, we investigate the effects of the anti-convulsant drug valproic acid (VPA) in HCC cells and its involvement in modulating Notch signaling. We found that VPA, acting as a histone deacetylase (HDAC) inhibitor, induced a decrease in HDAC4 and an increase in acetylated histone 4 (AcH4) and suppressed HCC cell growth. VPA also induced down-regulation of Notch signaling via suppressing the expression of Notch1 and its target gene HES1, with an increase of tumor suppressor p21 and p63. Furthermore, Notch1 activation via overexpressing Notch1 active form ICN1 induced HCC cell proliferation and anti-apoptosis, indicating Notch signaling played an oncogenic role in HCC cells. Meanwhile, VPA could reverse Notch1-induced increase of cell proliferation. Interestingly, VPA was also observed to stimulate the expression of G protein-coupled somatostatin receptor type 2 (SSTR2) that has been used in receptor-targeting therapies. This discovery supports a combination therapy of VPA with the SSTR2-targeting agents. Our in vitro assay did show that the combination of VPA and the peptide-drug conjugate camptothecin-somatostatin (CPT-SST) displayed more potent anti-proliferative effects on HCC cells than did each alone. VPA may be a potential drug candidate in the development of anti-HCC drugs via targeting Notch signaling, especially in combination with receptor-targeting cytotoxic agents. PMID:26366213

  13. Targeting Herpetic Keratitis by Gene Therapy

    PubMed Central

    Elbadawy, Hossein Mostafa; Gailledrat, Marine; Desseaux, Carole; Ponzin, Diego; Ferrari, Stefano

    2012-01-01

    Ocular gene therapy is rapidly becoming a reality. By November 2012, approximately 28 clinical trials were approved to assess novel gene therapy agents. Viral infections such as herpetic keratitis caused by herpes simplex virus 1 (HSV-1) can cause serious complications that may lead to blindness. Recurrence of the disease is likely and cornea transplantation, therefore, might not be the ideal therapeutic solution. This paper will focus on the current situation of ocular gene therapy research against herpetic keratitis, including the use of viral and nonviral vectors, routes of delivery of therapeutic genes, new techniques, and key research strategies. Whereas the correction of inherited diseases was the initial goal of the field of gene therapy, here we discuss transgene expression, gene replacement, silencing, or clipping. Gene therapy of herpetic keratitis previously reported in the literature is screened emphasizing candidate gene therapy targets. Commonly adopted strategies are discussed to assess the relative advantages of the protective therapy using antiviral drugs and the common gene therapy against long-term HSV-1 ocular infections signs, inflammation and neovascularization. Successful gene therapy can provide innovative physiological and pharmaceutical solutions against herpetic keratitis. PMID:23326647

  14. Stress-induced switch in Numb isoforms enhances Notch-dependent expression of subtype-specific transient receptor potential channel.

    PubMed

    Kyriazis, George A; Belal, Cherine; Madan, Meenu; Taylor, David G; Wang, Jang; Wei, Zelan; Pattisapu, Jogi V; Chan, Sic L

    2010-02-26

    The Notch signaling pathway plays an essential role in the regulation of cell specification by controlling differentiation, proliferation, and apoptosis. Numb is an intrinsic regulator of the Notch pathway and exists in four alternative splice variants that differ in the length of their phosphotyrosine-binding domain (PTB) and proline-rich region domains. The physiological relevance of the existence of the Numb splice variants and their exact regulation are still poorly understood. We previously reported that Numb switches from isoforms containing the insertion in PTB to isoforms lacking this insertion in neuronal cells subjected to trophic factor withdrawal (TFW). The functional relevance of the TFW-induced switch in Numb isoforms is not known. Here we provide evidence that the TFW-induced switch in Numb isoforms regulates Notch signaling strength and Notch target gene expression. PC12 cells stably overexpressing Numb isoforms lacking the PTB insertion exhibited higher basal Notch activity and Notch-dependent transcription of the transient receptor potential channel 6 (TRPC6) when compared with those overexpressing Numb isoforms with the PTB insertion. The differential regulation of TRPC6 expression is correlated with perturbed calcium signaling and increased neuronal vulnerability to TFW-induced death. Pharmacological inhibition of the Notch pathway or knockdown of TRPC6 function ameliorates the adverse effects caused by the TFW-induced switch in Numb isoforms. Taken together, our results indicate that Notch and Numb interaction may influence the sensitivity of neuronal cells to injurious stimuli by modulating calcium-dependent apoptotic signaling cascades.

  15. Distinct prognostic values of four-Notch-receptor mRNA expression in ovarian cancer.

    PubMed

    Zhou, Xinling; Teng, Lingling; Wang, Min

    2016-05-01

    Notch signaling pathway includes ligands and Notch receptors, which are frequently deregulated in several human malignancies including ovarian cancer. Aberrant activation of Notch signaling has been linked to ovarian carcinogenesis and progression. In the current study, we used the "Kaplan-Meier plotter" (KM plotter) database, in which updated gene expression data and survival information from a total of 1306 ovarian cancer patients were used to access the prognostic value of four Notch receptors in ovarian cancer patients. Hazard ratio (HR), 95 % confidence intervals, and log-rank P were calculated. Notch1 messenger RNA (mRNA) high expression was not found to be correlated to overall survival (OS) for all ovarian cancer, as well as in serous and endometrioid cancer patients followed for 20 years. However, Notch1 mRNA high expression is significantly associated with worsen OS in TP53 wild-type ovarian cancer patients, while it is significantly associated with better OS in TP53 mutation-type ovarian cancer patients. Notch2 mRNA high expression was found to be significantly correlated to worsen OS for all ovarian cancer patients, as well as in grade II ovarian cancer patients. Notch3 mRNA high expression was found to be significantly correlated to better OS for all ovarian cancer patients, but not in serous cancer patients and endometrioid cancer patients. Notch4 mRNA high expression was not found to be significantly correlated to OS for all ovarian cancer patients, serous cancer patients, and endometrioid cancer patients. These results indicate that there are distinct prognostic values of four Notch receptors in ovarian cancer. This information will be useful for better understanding of the heterogeneity and complexity in the molecular biology of ovarian cancer and for developing tools to more accurately predict their prognosis. Based on our results, Notch1 could be a potential drug target of TP53 wild-type ovarian cancer and Notch2 could be a potential drug

  16. Anti-estrogen Resistance in Human Breast Tumors Is Driven by JAG1-NOTCH4-Dependent Cancer Stem Cell Activity.

    PubMed

    Simões, Bruno M; O'Brien, Ciara S; Eyre, Rachel; Silva, Andreia; Yu, Ling; Sarmiento-Castro, Aida; Alférez, Denis G; Spence, Kath; Santiago-Gómez, Angélica; Chemi, Francesca; Acar, Ahmet; Gandhi, Ashu; Howell, Anthony; Brennan, Keith; Rydén, Lisa; Catalano, Stefania; Andó, Sebastiano; Gee, Julia; Ucar, Ahmet; Sims, Andrew H; Marangoni, Elisabetta; Farnie, Gillian; Landberg, Göran; Howell, Sacha J; Clarke, Robert B

    2015-09-29

    Breast cancers (BCs) typically express estrogen receptors (ERs) but frequently exhibit de novo or acquired resistance to hormonal therapies. Here, we show that short-term treatment with the anti-estrogens tamoxifen or fulvestrant decrease cell proliferation but increase BC stem cell (BCSC) activity through JAG1-NOTCH4 receptor activation both in patient-derived samples and xenograft (PDX) tumors. In support of this mechanism, we demonstrate that high ALDH1 predicts resistance in women treated with tamoxifen and that a NOTCH4/HES/HEY gene signature predicts for a poor response/prognosis in 2 ER+ patient cohorts. Targeting of NOTCH4 reverses the increase in Notch and BCSC activity induced by anti-estrogens. Importantly, in PDX tumors with acquired tamoxifen resistance, NOTCH4 inhibition reduced BCSC activity. Thus, we establish that BCSC and NOTCH4 activities predict both de novo and acquired tamoxifen resistance and that combining endocrine therapy with targeting JAG1-NOTCH4 overcomes resistance in human breast cancers. PMID:26387946

  17. Anti-estrogen Resistance in Human Breast Tumors Is Driven by JAG1-NOTCH4-Dependent Cancer Stem Cell Activity

    PubMed Central

    Simões, Bruno M.; O’Brien, Ciara S.; Eyre, Rachel; Silva, Andreia; Yu, Ling; Sarmiento-Castro, Aida; Alférez, Denis G.; Spence, Kath; Santiago-Gómez, Angélica; Chemi, Francesca; Acar, Ahmet; Gandhi, Ashu; Howell, Anthony; Brennan, Keith; Rydén, Lisa; Catalano, Stefania; Andó, Sebastiano; Gee, Julia; Ucar, Ahmet; Sims, Andrew H.; Marangoni, Elisabetta; Farnie, Gillian; Landberg, Göran; Howell, Sacha J.; Clarke, Robert B.

    2015-01-01

    Summary Breast cancers (BCs) typically express estrogen receptors (ERs) but frequently exhibit de novo or acquired resistance to hormonal therapies. Here, we show that short-term treatment with the anti-estrogens tamoxifen or fulvestrant decrease cell proliferation but increase BC stem cell (BCSC) activity through JAG1-NOTCH4 receptor activation both in patient-derived samples and xenograft (PDX) tumors. In support of this mechanism, we demonstrate that high ALDH1 predicts resistance in women treated with tamoxifen and that a NOTCH4/HES/HEY gene signature predicts for a poor response/prognosis in 2 ER+ patient cohorts. Targeting of NOTCH4 reverses the increase in Notch and BCSC activity induced by anti-estrogens. Importantly, in PDX tumors with acquired tamoxifen resistance, NOTCH4 inhibition reduced BCSC activity. Thus, we establish that BCSC and NOTCH4 activities predict both de novo and acquired tamoxifen resistance and that combining endocrine therapy with targeting JAG1-NOTCH4 overcomes resistance in human breast cancers. PMID:26387946

  18. The Wnt and Delta-Notch signalling pathways interact to direct pair-rule gene expression via caudal during segment addition in the spider Parasteatoda tepidariorum.

    PubMed

    Schönauer, Anna; Paese, Christian L B; Hilbrant, Maarten; Leite, Daniel J; Schwager, Evelyn E; Feitosa, Natália Martins; Eibner, Cornelius; Damen, Wim G M; McGregor, Alistair P

    2016-07-01

    In short-germ arthropods, posterior segments are added sequentially from a segment addition zone (SAZ) during embryogenesis. Studies in spiders such as Parasteatoda tepidariorum have provided insights into the gene regulatory network (GRN) underlying segment addition, and revealed that Wnt8 is required for dynamic Delta (Dl) expression associated with the formation of new segments. However, it remains unclear how these pathways interact during SAZ formation and segment addition. Here, we show that Delta-Notch signalling is required for Wnt8 expression in posterior SAZ cells, but represses the expression of this Wnt gene in anterior SAZ cells. We also found that these two signalling pathways are required for the expression of the spider orthologues of even-skipped (eve) and runt-1 (run-1), at least in part via caudal (cad). Moreover, it appears that dynamic expression of eve in this spider does not require a feedback loop with run-1, as is found in the pair-rule circuit of the beetle Tribolium Taken together, our results suggest that the development of posterior segments in Parasteatoda is directed by dynamic interactions between Wnt8 and Delta-Notch signalling that are read out by cad, which is necessary but probably not sufficient to regulate the expression of eve and run-1 Our study therefore provides new insights towards better understanding the evolution and developmental regulation of segmentation in other arthropods, including insects. PMID:27287802

  19. The Wnt and Delta-Notch signalling pathways interact to direct pair-rule gene expression via caudal during segment addition in the spider Parasteatoda tepidariorum.

    PubMed

    Schönauer, Anna; Paese, Christian L B; Hilbrant, Maarten; Leite, Daniel J; Schwager, Evelyn E; Feitosa, Natália Martins; Eibner, Cornelius; Damen, Wim G M; McGregor, Alistair P

    2016-07-01

    In short-germ arthropods, posterior segments are added sequentially from a segment addition zone (SAZ) during embryogenesis. Studies in spiders such as Parasteatoda tepidariorum have provided insights into the gene regulatory network (GRN) underlying segment addition, and revealed that Wnt8 is required for dynamic Delta (Dl) expression associated with the formation of new segments. However, it remains unclear how these pathways interact during SAZ formation and segment addition. Here, we show that Delta-Notch signalling is required for Wnt8 expression in posterior SAZ cells, but represses the expression of this Wnt gene in anterior SAZ cells. We also found that these two signalling pathways are required for the expression of the spider orthologues of even-skipped (eve) and runt-1 (run-1), at least in part via caudal (cad). Moreover, it appears that dynamic expression of eve in this spider does not require a feedback loop with run-1, as is found in the pair-rule circuit of the beetle Tribolium Taken together, our results suggest that the development of posterior segments in Parasteatoda is directed by dynamic interactions between Wnt8 and Delta-Notch signalling that are read out by cad, which is necessary but probably not sufficient to regulate the expression of eve and run-1 Our study therefore provides new insights towards better understanding the evolution and developmental regulation of segmentation in other arthropods, including insects.

  20. Notch receptor expression in human brain arteriovenous malformations.

    PubMed

    Hill-Felberg, Sandra; Wu, Hope Hueizhi; Toms, Steven A; Dehdashti, Amir R

    2015-08-01

    The roles of the Notch pathway proteins in normal adult vascular physiology and the pathogenesis of brain arteriovenous malformations are not well-understood. Notch 1 and 4 have been detected in human and mutant mice vascular malformations respectively. Although mutations in the human Notch 3 gene caused a genetic form of vascular stroke and dementia, its role in arteriovenous malformations development has been unknown. In this study, we performed immunohistochemistry screening on tissue microarrays containing eight surgically resected human brain arteriovenous malformations and 10 control surgical epilepsy samples. The tissue microarrays were evaluated for Notch 1-4 expression. We have found that compared to normal brain vascular tissue Notch-3 was dramatically increased in brain arteriovenous malformations. Similarly, Notch 4 labelling was also increased in vascular malformations and was confirmed by western blot analysis. Notch 2 was not detectable in any of the human vessels analysed. Using both immunohistochemistry on microarrays and western blot analysis, we have found that Notch-1 expression was detectable in control vessels, and discovered a significant decrease of Notch 1 expression in vascular malformations. We have demonstrated that Notch 3 and 4, and not Notch 1, were highly increased in human arteriovenous malformations. Our findings suggested that Notch 4, and more importantly, Notch 3, may play a role in the development and pathobiology of human arteriovenous malformations.

  1. Kinase active Misshapen regulates Notch signaling in Drosophila melanogaster.

    PubMed

    Mishra, Abhinava K; Sachan, Nalani; Mutsuddi, Mousumi; Mukherjee, Ashim

    2015-11-15

    Notch signaling pathway represents a principal cellular communication system that plays a pivotal role during development of metazoans. Drosophila misshapen (msn) encodes a protein kinase, which is related to the budding yeast Ste20p (sterile 20 protein) kinase. In a genetic screen, using candidate gene approach to identify novel kinases involved in Notch signaling, we identified msn as a novel regulator of Notch signaling. Data presented here suggest that overexpression of kinase active form of Msn exhibits phenotypes similar to Notch loss-of-function condition and msn genetically interacts with components of Notch signaling pathway. Kinase active form of Msn associates with Notch receptor and regulate its signaling activity. We further show that kinase active Misshapen leads to accumulation of membrane-tethered form of Notch. Moreover, activated Msn also depletes Armadillo and DE-Cadherin from adherens junctions. Thus, this study provides a yet unknown mode of regulation of Notch signaling by Misshapen. PMID:26431585

  2. Inhibition of Notch3 signalling induces rhabdomyosarcoma cell differentiation promoting p38 phosphorylation and p21Cip1 expression and hampers tumour cell growth in vitro and in vivo

    PubMed Central

    Raimondi, L; Ciarapica, R; De Salvo, M; Verginelli, F; Gueguen, M; Martini, C; De Sio, L; Cortese, G; Locatelli, M; Dang, T P; Carlesso, N; Miele, L; Stifani, S; Limon, I; Locatelli, F; Rota, R

    2012-01-01

    Rhabdomyosarcoma (RMS) is a paediatric soft-tissue sarcoma arising from skeletal muscle precursors coexpressing markers of proliferation and differentiation. Inducers of myogenic differentiation suppress RMS tumourigenic phenotype. The Notch target gene HES1 is upregulated in RMS and prevents tumour cell differentiation in a Notch-dependent manner. However, Notch receptors regulating this phenomenon are unknown. In agreement with data in RMS primary tumours, we show here that the Notch3 receptor is overexpressed in RMS cell lines versus normal myoblasts. Notch3-targeted downregulation in RMS cells induces hyper-phosphorylation of p38 and Akt essential for myogenesis, resulting in the differentiation of tumour cells into multinucleated myotubes expressing Myosin Heavy Chain. These phenomena are associated to a marked decrease in HES1 expression, an increase in p21Cip1 level and the accumulation of RMS cells in the G1 phase. HES1-forced overexpression in RMS cells reverses, at least in part, the pro-differentiative effects of Notch3 downregulation. Notch3 depletion also reduces the tumourigenic potential of RMS cells both in vitro and in vivo. These results indicate that downregulation of Notch3 is sufficient to force RMS cells into completing a correct full myogenic program providing evidence that it contributes, partially through HES1 sustained expression, to their malignant phenotype. Moreover, they suggest Notch3 as a novel potential target in human RMS. PMID:22117196

  3. Notch signaling represses hypoxia-inducible factor-1α-induced activation of Wnt/β-catenin signaling in osteoblasts under cobalt-mimicked hypoxia

    PubMed Central

    LI, CHEN-TIAN; LIU, JIAN-XIU; YU, BO; LIU, RUI; DONG, CHAO; LI, SONG-JIAN

    2016-01-01

    The modification of Wnt and Notch signaling pathways by hypoxia, and its association with osteoblast proliferation and apoptosis remain to be fully elucidated. To investigate Wnt-Notch crosstalk, and its role in hypoxia-induced osteoblast proliferation and apoptosis regulation, the present study investigated the effects of cobalt-mimicked hypoxia on the mouse pre-osteoblast-like cell line, MC3T3-E1, when the Notch signals were repressed using a γ-secretase inhibitor DAPT. The data showed that the cobalt-mimicked hypoxia suppressed cell proliferation under normal conditions, but increased cell proliferation under conditions of Notch repression, in a concentration-dependent manner. The results of western blot and reverse transcription-quantitative polymerase chain reaction analyses showed that the cobalt treatment increased the levels of activated β-catenin protein and the expression levels of the target genes, axis inhibition protein 2 and myelocytomatosis oncogene, under DAPT-induced Notch repression. However, no significant changes were found in the expression levels of the Notch intracellular domain protein or the Notch target gene, hes1. In a β-catenin gene-knockdown experiment, the proliferation of the MC3T3-E1 cells under hypoxia were decreased by DAPT treatment, and knockdown of the expression of hypoxia-inducible factor-1α (HIF-1α) suppressed the cobalt-induced increase in Wnt target gene levels. No significant difference in cell proliferation rate was found following DAPT treatment when the expression of HIF-1α was knocked down. The results of the present study showed the opposing effects of Wnt and Notch signaling under cobalt-mimicked hypoxia, which were partially regulated by HIF-1α, The results also showed that osteoblast proliferation was dependent on Wnt-Notch signal crosstalk. PMID:27220406

  4. Biallelic Gene Targeting in Rice1[OPEN

    PubMed Central

    Mikami, Masafumi

    2016-01-01

    Sequence-specific nucleases (SSNs) have been used successfully in homology-directed repair (HDR)-mediated gene targeting (GT) in many organisms. However, break-induced GT in plants remains challenging due to inefficient delivery of HDR templates and SSNs into plant nuclei. In many plants, including rice, Agrobacterium-mediated transformation is the most practical means of transformation because this biotic transformation system can deliver longer and more intact DNA payloads with less incorporation of fragmented DNA compared with physical transformation systems such as polyethylene glycol, electroporation, or biolistics. Following infection with Agrobacterium, transfer of transfer DNA (T-DNA) to the nucleus and its integration into the plant genome occur consecutively during cocultivation, thus timing the induction of DNA double-strand breaks (DSBs) on the target gene to coincide with the delivery of the HDR template is crucial. To synchronize DSB induction and delivery of the HDR template, we transformed a Cas9 expression construct and GT vector harboring the HDR template with guide RNAs (gRNAs) targeting the rice acetolactate synthase (ALS) gene either separately or sequentially into rice calli. When gRNAs targeting ALS were transcribed transiently from double-stranded T-DNA containing the HDR template, DSBs were induced in the ALS locus by the assembled Cas9/gRNA complex and homologous recombination was stimulated. Contrary to our expectations, there was no great difference in GT efficiency between Cas9-expressing and nonexpressing cells. However, when gRNA targeting DNA ligase 4 was transformed with Cas9 prior to the GT experiment, GT efficiency increased dramatically and more than one line exhibiting biallelic GT at the ALS locus was obtained. PMID:26668334

  5. Notch1 Activation or Loss Promotes HPV-Induced Oral Tumorigenesis.

    PubMed

    Zhong, Rong; Bao, Riyue; Faber, Pieter W; Bindokas, Vytautas P; Bechill, John; Lingen, Mark W; Spiotto, Michael T

    2015-09-15

    Viral oncogene expression is insufficient for neoplastic transformation of human cells, so human papillomavirus (HPV)-associated cancers will also rely upon mutations in cellular oncogenes and tumor suppressors. However, it has been difficult so far to distinguish incidental mutations without phenotypic impact from causal mutations that drive the development of HPV-associated cancers. In this study, we addressed this issue by conducting a functional screen for genes that facilitate the formation of HPV E6/E7-induced squamous cell cancers in mice using a transposon-mediated insertional mutagenesis protocol. Overall, we identified 39 candidate driver genes, including Notch1, which unexpectedly was scored by gain- or loss-of-function mutations that were capable of promoting squamous cell carcinogenesis. Autochthonous HPV-positive oral tumors possessing an activated Notch1 allele exhibited high rates of cell proliferation and tumor growth. Conversely, Notch1 loss could accelerate the growth of invasive tumors in a manner associated with increased expression of matrix metalloproteinases and other proinvasive genes. HPV oncogenes clearly cooperated with loss of Notch1, insofar as its haploinsufficiency accelerated tumor growth only in HPV-positive tumors. In clinical specimens of various human cancers, there was a consistent pattern of NOTCH1 expression that correlated with invasive character, in support of our observations in mice. Although Notch1 acts as a tumor suppressor in mouse skin, we found that oncogenes enabling any perturbation in Notch1 expression promoted tumor growth, albeit via distinct pathways. Our findings suggest caution in interpreting the meaning of putative driver gene mutations in cancer, and therefore therapeutic efforts to target them, given the significant contextual differences in which such mutations may arise, including in virus-associated tumors.

  6. Notch1 activation or loss promotes HPV-induced oral tumorigenesis

    PubMed Central

    Faber, Pieter W.; Bindokas, Vytautas P.; Bechill, John; Lingen, Mark W.; Spiotto, Michael T.

    2015-01-01

    Viral oncogene expression is insufficient for neoplastic transformation of human cells, so HPV-associated cancers will also rely upon mutations in cellular oncogenes and tumor suppressors. However, it has been difficult so far to distinguish incidental mutations without phenotypic impact from causal mutations that drive the development of HPV-associated cancers. In this study, we addressed this issue by conducting a functional screen for genes that facilitate the formation of HPV E6/E7-induced squamous cell cancers in mice using a transposon-mediated insertional mutagenesis protocol. Overall, we identified 39 candidate driver genes including Notch1, which unexpectedly was scored by gain or loss of function mutations that were capable of promoting squamous cell carcinogenesis. Autochthonous HPV-positive oral tumors possessing an activated Notch1 allele exhibited high rates of cell proliferation and tumor growth. Conversely, Notch1 loss could accelerate the growth of invasive tumors in manner associated with increased expression of matrix metalloproteinases and other pro-invasive genes. HPV oncogenes clearly cooperated with loss of Notch1, insofar as its haploinsufficiency accelerated tumor growth only in HPV-positive tumors. In clinical specimens of various human cancers, there was a consistent pattern of NOTCH1 expression that correlated with invasive character, in support of our observations in mice. While Notch1 acts as a tumor suppressor in mouse skin, we found that oncogenes enabling any perturbation in Notch1 expression promoted tumor growth, albeit via distinct pathways. Our findings suggest caution in interpreting the meaning of putative driver gene mutations in cancer, and therefore therapeutic efforts to target them, given the significant contextual differences in which such mutations may arise, including in virus-associated tumors. PMID:26294213

  7. A simple model for gene targeting.

    PubMed Central

    Ratilainen, T; Lincoln, P; Nordén, B

    2001-01-01

    Sequence-specific binding to genomic-size DNA sequences by artificial agents is of major interest for the development of gene-targeting strategies, gene-diagnostic applications, and biotechnical tools. The binding of one such agent, peptide nucleic acid (PNA), to a randomized human genome has been modeled with statistical mass action calculations. With the length of the PNA probe, the average per-base binding constant k(0), and the binding affinity loss of a mismatched base pair as main parameters, the specificity was gauged as a "therapeutic ratio" G = maximum safe [PNA](tot)/minimal efficient [PNA](tot). This general, though simple, model suggests that, above a certain threshold length of the PNA, the microscopic binding constant k(0) is the primary determinant for optimal discrimination, and that only a narrow range of rather low k(0) values gives a high therapeutic ratio G. For diagnostic purposes, the value of k(0) could readily be modulated by changing the temperature, due to the substantial Delta H degrees associated with the binding equilibrium. Applied to gene therapy, our results stress the need for appropriate control of the binding constant and added amount of the gene-targeting agent, to meet the varying conditions (ionic strength, presence of competing DNA-binding molecules) found in the cell. PMID:11606298

  8. A conserved role for Notch signaling in priming the cellular response to Shh through ciliary localisation of the key Shh transducer Smo.

    PubMed

    Stasiulewicz, Magdalena; Gray, Shona D; Mastromina, Ioanna; Silva, Joana C; Björklund, Mia; Seymour, Philip A; Booth, David; Thompson, Calum; Green, Richard J; Hall, Emma A; Serup, Palle; Dale, J Kim

    2015-07-01

    Notochord-derived Sonic Hedgehog (Shh) is essential for dorsoventral patterning of the overlying neural tube. Increasing concentration and duration of Shh signal induces progenitors to acquire progressively more ventral fates. We show that Notch signalling augments the response of neuroepithelial cells to Shh, leading to the induction of higher expression levels of the Shh target gene Ptch1 and subsequently induction of more ventral cell fates. Furthermore, we demonstrate that activated Notch1 leads to pronounced accumulation of Smoothened (Smo) within primary cilia and elevated levels of full-length Gli3. Finally, we show that Notch activity promotes longer primary cilia both in vitro and in vivo. Strikingly, these Notch-regulated effects are Shh independent. These data identify Notch signalling as a novel modulator of Shh signalling that acts mechanistically via regulation of ciliary localisation of key components of its transduction machinery. PMID:25995356

  9. A conserved role for Notch signaling in priming the cellular response to Shh through ciliary localisation of the key Shh transducer Smo

    PubMed Central

    Stasiulewicz, Magdalena; Gray, Shona D.; Mastromina, Ioanna; Silva, Joana C.; Björklund, Mia; Seymour, Philip A.; Booth, David; Thompson, Calum; Green, Richard J.; Hall, Emma A.; Serup, Palle; Dale, J. Kim

    2015-01-01

    Notochord-derived Sonic Hedgehog (Shh) is essential for dorsoventral patterning of the overlying neural tube. Increasing concentration and duration of Shh signal induces progenitors to acquire progressively more ventral fates. We show that Notch signalling augments the response of neuroepithelial cells to Shh, leading to the induction of higher expression levels of the Shh target gene Ptch1 and subsequently induction of more ventral cell fates. Furthermore, we demonstrate that activated Notch1 leads to pronounced accumulation of Smoothened (Smo) within primary cilia and elevated levels of full-length Gli3. Finally, we show that Notch activity promotes longer primary cilia both in vitro and in vivo. Strikingly, these Notch-regulated effects are Shh independent. These data identify Notch signalling as a novel modulator of Shh signalling that acts mechanistically via regulation of ciliary localisation of key components of its transduction machinery. PMID:25995356

  10. A facile one-step strategy for the generation of conditional knockout mice to explore the role of Notch1 in oroesophageal tumorigenesis.

    PubMed

    Mandasari, Masita; Sawangarun, Wanlada; Katsube, Ken-ichi; Kayamori, Kou; Yamaguchi, Akira; Sakamoto, Kei

    2016-01-15

    NOTCH1 plays an important role in epithelial differentiation and carcinogenesis. To investigate the impact of Notch1 inactivation in oroesophageal epithelium, we generated conditional knockout (cKO) mice, using a combined construct which induces the expression of single guide RNA targeting Notch1 and Cas9 by the KRT14 promoter. The cKO mice exhibited patchy hair loss and multiple NOTCH1-negative areas in the tongue epithelium, indicative of heterogeneous knockout. The cKO mice showed susceptibility to esophageal tumorigenesis, underscoring Notch1 as a tumor suppressor. Our one-step strategy for generation of cKO mice provides a versatile method to examine a gene function in vivo. PMID:26682927

  11. Assembly of a Notch transcriptional activation complex requires multimerization.

    PubMed

    Vasquez-Del Carpio, Rodrigo; Kaplan, Fred M; Weaver, Kelly L; VanWye, Jeffrey D; Alves-Guerra, Marie-Clotilde; Robbins, David J; Capobianco, Anthony J

    2011-04-01

    Notch transmembrane receptors direct essential cellular processes, such as proliferation and differentiation, through direct cell-to-cell interactions. Inappropriate release of the intracellular domain of Notch (N(ICD)) from the plasma membrane results in the accumulation of deregulated nuclear N(ICD) that has been linked to human cancers, notably T-cell acute lymphoblastic leukemia (T-ALL). Nuclear N(ICD) forms a transcriptional activation complex by interacting with the coactivator protein Mastermind-like 1 and the DNA binding protein CSL (for CBF-1/Suppressor of Hairless/Lag-1) to regulate target gene expression. Although it is well understood that N(ICD) forms a transcriptional activation complex, little is known about how the complex is assembled. In this study, we demonstrate that N(ICD) multimerizes and that these multimers function as precursors for the stepwise assembly of the Notch activation complex. Importantly, we demonstrate that the assembly is mediated by N(ICD) multimers interacting with Skip and Mastermind. These interactions form a preactivation complex that is then resolved by CSL to form the Notch transcriptional activation complex on DNA.

  12. Elevated TRIB2 with NOTCH1 activation in paediatric/adult T-ALL.

    PubMed

    Hannon, Maura M; Lohan, Fiona; Erbilgin, Yucel; Sayitoglu, Muge; O'Hagan, Kathleen; Mills, Ken; Ozbek, Ugur; Keeshan, Karen

    2012-09-01

    TRIB2 is a potent oncogene, elevated in a subset of human acute myeloid leukaemias (AML) with a mixed myeloid/lymphoid phenotype and NOTCH1 mutations. Although rare in AML, activating NOTCH1 mutations occur in 50% of all T cell acute lymphoblastic leukaemias (T-ALL). TRIB2 is a NOTCH1 target gene that functions in the degradation of key proteins and modulation of MAPK signalling pathways, implicated in haematopoietic cell survival and proliferation. This study showed that TRIB2 expression level is highest in the lymphoid compartment of normal haematopoietic cells, specifically in T cells. Analysis of TRIB2 expression across 16 different subtypes of human leukaemia demonstrated that TRIB2 expression was higher in ALL phenotypes versus all other phenotypes including AML, chronic lymphocytic leukaemia (CLL), myelodysplastic syndrome (MDS) and chronic myeloid leukaemia (CML). A T cell profile was distinguished by high TRIB2 expression in normal and malignant haematopoiesis. High TRIB2 expression was seen in T-ALL with normal karyotype and correlated with NOTCH signalling pathways. High TRIB2 expression correlated with NOTCH1/FBXW7 mutations in a paediatric T-ALL cohort, strongly linking NOTCH1 activation and high TRIB2 expression in paediatric T-ALL. The relationship between TRIB2 and T cell signalling pathways uniquely identifies leukaemia subtypes and will be useful in the advancement of our understanding of T cell and ALL biology. PMID:22775572

  13. Family Based Whole Exome Sequencing Reveals the Multifaceted Role of Notch Signaling in Congenital Heart Disease

    PubMed Central

    Chetaille, Philippe; Prince, Andrea; Godard, Beatrice; Leclerc, Severine; Sobreira, Nara; Ling, Hua; Awadalla, Philip; Thibeault, Maryse; Khairy, Paul; Samuels, Mark E.; Andelfinger, Gregor

    2016-01-01

    Left-ventricular outflow tract obstructions (LVOTO) encompass a wide spectrum of phenotypically heterogeneous heart malformations which frequently cluster in families. We performed family based whole-exome and targeted re-sequencing on 182 individuals from 51 families with multiple affected members. Central to our approach is the family unit which serves as a reference to identify causal genotype-phenotype correlations. Screening a multitude of 10 overlapping phenotypes revealed disease associated and co-segregating variants in 12 families. These rare or novel protein altering mutations cluster predominantly in genes (NOTCH1, ARHGAP31, MAML1, SMARCA4, JARID2, JAG1) along the Notch signaling cascade. This is in line with a significant enrichment (Wilcoxon, p< 0.05) of variants with a higher pathogenicity in the Notch signaling pathway in patients compared to controls. The significant enrichment of novel protein truncating and missense mutations in NOTCH1 highlights the allelic and phenotypic heterogeneity in our pediatric cohort. We identified novel co-segregating pathogenic mutations in NOTCH1 associated with left and right-sided cardiac malformations in three independent families with a total of 15 affected individuals. In summary, our results suggest that a small but highly pathogenic fraction of family specific mutations along the Notch cascade are a common cause of LVOTO. PMID:27760138

  14. Elevated TRIB2 with NOTCH1 activation in paediatric/adult T-ALL.

    PubMed

    Hannon, Maura M; Lohan, Fiona; Erbilgin, Yucel; Sayitoglu, Muge; O'Hagan, Kathleen; Mills, Ken; Ozbek, Ugur; Keeshan, Karen

    2012-09-01

    TRIB2 is a potent oncogene, elevated in a subset of human acute myeloid leukaemias (AML) with a mixed myeloid/lymphoid phenotype and NOTCH1 mutations. Although rare in AML, activating NOTCH1 mutations occur in 50% of all T cell acute lymphoblastic leukaemias (T-ALL). TRIB2 is a NOTCH1 target gene that functions in the degradation of key proteins and modulation of MAPK signalling pathways, implicated in haematopoietic cell survival and proliferation. This study showed that TRIB2 expression level is highest in the lymphoid compartment of normal haematopoietic cells, specifically in T cells. Analysis of TRIB2 expression across 16 different subtypes of human leukaemia demonstrated that TRIB2 expression was higher in ALL phenotypes versus all other phenotypes including AML, chronic lymphocytic leukaemia (CLL), myelodysplastic syndrome (MDS) and chronic myeloid leukaemia (CML). A T cell profile was distinguished by high TRIB2 expression in normal and malignant haematopoiesis. High TRIB2 expression was seen in T-ALL with normal karyotype and correlated with NOTCH signalling pathways. High TRIB2 expression correlated with NOTCH1/FBXW7 mutations in a paediatric T-ALL cohort, strongly linking NOTCH1 activation and high TRIB2 expression in paediatric T-ALL. The relationship between TRIB2 and T cell signalling pathways uniquely identifies leukaemia subtypes and will be useful in the advancement of our understanding of T cell and ALL biology.

  15. Integrative genetic, epigenetic and pathological analysis of paraganglioma reveals complex dysregulation of NOTCH signaling.

    PubMed

    Cama, Alessandro; Verginelli, Fabio; Lotti, Lavinia Vittoria; Napolitano, Francesco; Morgano, Annalisa; D'Orazio, Andria; Vacca, Michele; Perconti, Silvia; Pepe, Felice; Romani, Federico; Vitullo, Francesca; di Lella, Filippo; Visone, Rosa; Mannelli, Massimo; Neumann, Hartmut P H; Raiconi, Giancarlo; Paties, Carlo; Moschetta, Antonio; Tagliaferri, Roberto; Veronese, Angelo; Sanna, Mario; Mariani-Costantini, Renato

    2013-10-01

    Head and neck paragangliomas, rare neoplasms of the paraganglia composed of nests of neurosecretory and glial cells embedded in vascular stroma, provide a remarkable example of organoid tumor architecture. To identify genes and pathways commonly deregulated in head and neck paraganglioma, we integrated high-density genome-wide copy number variation (CNV) analysis with microRNA and immunomorphological studies. Gene-centric CNV analysis of 24 cases identified a list of 104 genes most significantly targeted by tumor-associated alterations. The "NOTCH signaling pathway" was the most significantly enriched term in the list (P = 0.002 after Bonferroni or Benjamini correction). Expression of the relevant NOTCH pathway proteins in sustentacular (glial), chief (neuroendocrine) and endothelial cells was confirmed by immunohistochemistry in 47 head and neck paraganglioma cases. There were no relationships between level and pattern of NOTCH1/JAG2 protein expression and germline mutation status in the SDH genes, implicated in paraganglioma predisposition, or the presence/absence of immunostaining for SDHB, a surrogate marker of SDH mutations. Interestingly, NOTCH upregulation was observed also in cases with no evidence of CNVs at NOTCH signaling genes, suggesting altered epigenetic modulation of this pathway. To address this issue we performed microarray-based microRNA expression analyses. Notably 5 microRNAs (miR-200a,b,c and miR-34b,c), including those most downregulated in the tumors, correlated to NOTCH signaling and directly targeted NOTCH1 in in vitro experiments using SH-SY5Y neuroblastoma cells. Furthermore, lentiviral transduction of miR-200s and miR-34s in patient-derived primary tympano-jugular paraganglioma cell cultures was associated with NOTCH1 downregulation and increased levels of markers of cell toxicity and cell death. Taken together, our results provide an integrated view of common molecular alterations associated with head and neck paraganglioma and

  16. Targeting gene therapy vectors to CNS malignancies.

    PubMed

    Spear, M A; Herrlinger, U; Rainov, N; Pechan, P; Weissleder, R; Breakefield, X O

    1998-04-01

    Gene therapy offers significant advantages to the field of oncology with the addition of specifically and uniquely engineered mechanisms of halting malignant proliferation through cytotoxicity or reproductive arrest. To confer a true benefit to the therapeutic ratio (the relative toxicity to tumor compared to normal tissue) a vector or the transgene it carries must selectively affect or access tumor cells. Beyond the selective toxicities of many transgene products, which frequently parallel that of contemporary chemotherapeutic agents, lies the potential utility of targeting the vector. This review presents an overview of current and potential methods for designing vectors targeted to CNS malignancies through selective delivery, cell entry, transport or transcriptional regulation. The topic of delivery encompasses physical and pharmaceutic means of increasing the relative exposure of tumors to vector. Cell entry based methodologies are founded on increasing relative uptake of vector through the chemical or recombinant addition of ligand and antibody domains which selectively bind receptors expressed on target cells. Targeted transport involves the potential for using cells to selectively carry vectors or transgenes into tumors. Finally, promoter and enhancer systems are discussed which have potential for selectivity activating transcription to produce targeted transgene expression or vector propagation. PMID:9584951

  17. Chromatin signatures at Notch-regulated enhancers reveal large-scale changes in H3K56ac upon activation

    PubMed Central

    Skalska, Lenka; Stojnic, Robert; Li, Jinghua; Fischer, Bettina; Cerda-Moya, Gustavo; Sakai, Hiroshi; Tajbakhsh, Shahragim; Russell, Steven; Adryan, Boris; Bray, Sarah J

    2015-01-01

    The conserved Notch pathway functions in diverse developmental and disease-related processes, requiring mechanisms to ensure appropriate target selection and gene activation in each context. To investigate the influence of chromatin organisation and dynamics on the response to Notch signalling, we partitioned Drosophila chromatin using histone modifications and established the preferred chromatin conditions for binding of Su(H), the Notch pathway transcription factor. By manipulating activity of a co-operating factor, Lozenge/Runx, we showed that it can help facilitate these conditions. While many histone modifications were unchanged by Su(H) binding or Notch activation, we detected rapid changes in acetylation of H3K56 at Notch-regulated enhancers. This modification extended over large regions, required the histone acetyl-transferase CBP and was independent of transcription. Such rapid changes in H3K56 acetylation appear to be a conserved indicator of enhancer activation as they also occurred at the mammalian Notch-regulated Hey1 gene and at Drosophila ecdysone-regulated genes. This intriguing example of a core histone modification increasing over short timescales may therefore underpin changes in chromatin accessibility needed to promote transcription following signalling activation. PMID:26069324

  18. Chromatin signatures at Notch-regulated enhancers reveal large-scale changes in H3K56ac upon activation.

    PubMed

    Skalska, Lenka; Stojnic, Robert; Li, Jinghua; Fischer, Bettina; Cerda-Moya, Gustavo; Sakai, Hiroshi; Tajbakhsh, Shahragim; Russell, Steven; Adryan, Boris; Bray, Sarah J

    2015-07-14

    The conserved Notch pathway functions in diverse developmental and disease-related processes, requiring mechanisms to ensure appropriate target selection and gene activation in each context. To investigate the influence of chromatin organisation and dynamics on the response to Notch signalling, we partitioned Drosophila chromatin using histone modifications and established the preferred chromatin conditions for binding of Su(H), the Notch pathway transcription factor. By manipulating activity of a co-operating factor, Lozenge/Runx, we showed that it can help facilitate these conditions. While many histone modifications were unchanged by Su(H) binding or Notch activation, we detected rapid changes in acetylation of H3K56 at Notch-regulated enhancers. This modification extended over large regions, required the histone acetyl-transferase CBP and was independent of transcription. Such rapid changes in H3K56 acetylation appear to be a conserved indicator of enhancer activation as they also occurred at the mammalian Notch-regulated Hey1 gene and at Drosophila ecdysone-regulated genes. This intriguing example of a core histone modification increasing over short timescales may therefore underpin changes in chromatin accessibility needed to promote transcription following signalling activation. PMID:26069324

  19. Protein O-fucosyltransferase 1 expression impacts myogenic C2C12 cell commitment via the Notch signaling pathway.

    PubMed

    Der Vartanian, Audrey; Audfray, Aymeric; Al Jaam, Bilal; Janot, Mathilde; Legardinier, Sébastien; Maftah, Abderrahman; Germot, Agnès

    2015-01-01

    The Notch signaling pathway plays a crucial role in skeletal muscle regeneration in mammals by controlling the transition of satellite cells from quiescence to an activated state, their proliferation, and their commitment toward myotubes or self-renewal. O-fucosylation on Notch receptor epidermal growth factor (EGF)-like repeats is catalyzed by the protein O-fucosyltransferase 1 (Pofut1) and primarily controls Notch interaction with its ligands. To approach the role of O-fucosylation in myogenesis, we analyzed a murine myoblastic C2C12 cell line downregulated for Pofut1 expression by short hairpin RNA (shRNA) inhibition during the time course of differentiation. Knockdown of Pofut1 affected the signaling pathway activation by a reduction of the amount of cleaved Notch intracellular domain and a decrease in downstream Notch target gene expression. Depletion in Pax7(+)/MyoD(-) cells and earlier myogenic program entrance were observed, leading to an increase in myotube quantity with a small number of nuclei, reflecting fusion defects. The rescue of Pofut1 expression in knockdown cells restored Notch signaling activation and a normal course in C2C12 differentiation. Our results establish the critical role of Pofut1 on Notch pathway activation during myogenic differentiation.

  20. Protein O-Fucosyltransferase 1 Expression Impacts Myogenic C2C12 Cell Commitment via the Notch Signaling Pathway

    PubMed Central

    Der Vartanian, Audrey; Audfray, Aymeric; Al Jaam, Bilal; Janot, Mathilde; Legardinier, Sébastien; Maftah, Abderrahman

    2014-01-01

    The Notch signaling pathway plays a crucial role in skeletal muscle regeneration in mammals by controlling the transition of satellite cells from quiescence to an activated state, their proliferation, and their commitment toward myotubes or self-renewal. O-fucosylation on Notch receptor epidermal growth factor (EGF)-like repeats is catalyzed by the protein O-fucosyltransferase 1 (Pofut1) and primarily controls Notch interaction with its ligands. To approach the role of O-fucosylation in myogenesis, we analyzed a murine myoblastic C2C12 cell line downregulated for Pofut1 expression by short hairpin RNA (shRNA) inhibition during the time course of differentiation. Knockdown of Pofut1 affected the signaling pathway activation by a reduction of the amount of cleaved Notch intracellular domain and a decrease in downstream Notch target gene expression. Depletion in Pax7+/MyoD− cells and earlier myogenic program entrance were observed, leading to an increase in myotube quantity with a small number of nuclei, reflecting fusion defects. The rescue of Pofut1 expression in knockdown cells restored Notch signaling activation and a normal course in C2C12 differentiation. Our results establish the critical role of Pofut1 on Notch pathway activation during myogenic differentiation. PMID:25384974

  1. Endosomal sorting of Notch receptors through COMMD9-dependent pathways modulates Notch signaling

    PubMed Central

    Li, Haiying; Koo, Yeon; Mao, Xicheng; Sifuentes-Dominguez, Luis; Morris, Lindsey L.; Jia, Da; Miyata, Naoteru; Faulkner, Rebecca A.; van Deursen, Jan M.; Vooijs, Marc; Billadeau, Daniel D.; van de Sluis, Bart; Cleaver, Ondine

    2015-01-01

    Notch family members are transmembrane receptors that mediate essential developmental programs. Upon ligand binding, a proteolytic event releases the intracellular domain of Notch, which translocates to the nucleus to regulate gene transcription. In addition, Notch trafficking across the endolysosomal system is critical in its regulation. In this study we report that Notch recycling to the cell surface is dependent on the COMMD–CCDC22–CCDC93 (CCC) complex, a recently identified regulator of endosomal trafficking. Disruption in this system leads to intracellular accumulation of Notch2 and concomitant reduction in Notch signaling. Interestingly, among the 10 copper metabolism MURR1 domain containing (COMMD) family members that can associate with the CCC complex, only COMMD9 and its binding partner, COMMD5, have substantial effects on Notch. Furthermore, Commd9 deletion in mice leads to embryonic lethality and complex cardiovascular alterations that bear hallmarks of Notch deficiency. Altogether, these studies highlight that the CCC complex controls Notch activation by modulating its intracellular trafficking and demonstrate cargo-specific effects for members of the COMMD protein family. PMID:26553930

  2. Modulation of Notch signaling by antibodies specific for the extracellular negative regulatory region of NOTCH3.

    PubMed

    Li, Kang; Li, Yucheng; Wu, Wenjuan; Gordon, Wendy R; Chang, David W; Lu, Mason; Scoggin, Shane; Fu, Tihui; Vien, Long; Histen, Gavin; Zheng, Ji; Martin-Hollister, Rachel; Duensing, Thomas; Singh, Sanjaya; Blacklow, Stephen C; Yao, Zhengbin; Aster, Jon C; Zhou, Bin-Bing S

    2008-03-21

    The Notch pathway regulates the development of many tissues and cell types and is involved in a variety of human diseases, making it an attractive potential therapeutic target. This promise has been limited by the absence of potent inhibitors or agonists that are specific for individual human Notch receptors (NOTCH1-4). Using an unbiased functional screening, we identified monoclonal antibodies that specifically inhibit or induce activating proteolytic cleavages in NOTCH3. Remarkably, the most potent inhibitory and activating antibodies bind to overlapping epitopes within a juxtamembrane negative regulatory region that protects NOTCH3 from proteolysis and activation in its resting autoinhibited state. The inhibitory antibodies revert phenotypes conveyed on 293T cells by NOTCH3 signaling, such as increased cellular proliferation, survival, and motility, whereas the activating antibody mimics some of the effects of ligand-induced Notch activation. These findings provide insights into the mechanisms of Notch autoinhibition and activation and pave the way for the further development of specific antibody-based modulators of the Notch receptors, which are likely to be of utility in a wide range of experimental and therapeutic settings. PMID:18182388

  3. The canonical Notch pathway effector RBP-J regulates neuronal plasticity and expression of GABA transporters in hippocampal networks.

    PubMed

    Liu, Shuxi; Wang, Yue; Worley, Paul F; Mattson, Mark P; Gaiano, Nicholas

    2015-05-01

    Activation of the Notch pathway in neurons is essential for learning and memory in various species from invertebrates to mammals. However, it remains unclear how Notch signaling regulates neuronal plasticity, and whether the transcriptional regulator and canonical pathway effector RBP-J plays a role. Here, we report that conditional disruption of RBP-J in the postnatal hippocampus leads to defects in long-term potentiation, long-term depression, and in learning and memory. Using gene expression profiling and chromatin immunoprecipitation, we identified two GABA transporters, GAT2 and BGT1, as putative Notch/RBP-J pathway targets, which may function downstream of RBP-J to limit the accumulation of GABA in the Schaffer collateral pathway. Our results reveal an essential role for canonical Notch/RBP-J signaling in hippocampal synaptic plasticity and suggest that role, at least in part, is mediated by the regulation of GABAergic signaling. PMID:25515406

  4. The canonical Notch pathway effector RBP-J regulates neuronal plasticity and expression of GABA transporters in hippocampal networks

    PubMed Central

    Liu, Shuxi; Wang, Yue; Worley, Paul F.; Mattson, Mark P.; Gaiano, Nicholas

    2014-01-01

    Activation of the Notch pathway in neurons is essential for learning and memory in various species from invertebrates to mammals. However, it remains unclear how Notch signaling regulates neuronal plasticity, and whether the transcriptional regulator and canonical pathway effector RBP-J plays a role. Here we report that conditional disruption of RBP-J in the postnatal hippocampus leads to defects in long-term potentiation (LTP), long-term depression (LTD), and in learning and memory. Using gene expression profiling and chromatin immunoprecipitation, we identified two GABA transporters, GAT2 and BGT1, as putative Notch/RBP-J pathway targets, which may function downstream of RBP-J to limit the accumulation of GABA in the Schaffer collateral pathway. Our results reveal an essential role for canonical Notch/RBP-J signaling in hippocampal synaptic plasticity and suggest that role, at least in part, is mediated by the regulation of GABAergic signaling. PMID:25515406

  5. The canonical Notch pathway effector RBP-J regulates neuronal plasticity and expression of GABA transporters in hippocampal networks.

    PubMed

    Liu, Shuxi; Wang, Yue; Worley, Paul F; Mattson, Mark P; Gaiano, Nicholas

    2015-05-01

    Activation of the Notch pathway in neurons is essential for learning and memory in various species from invertebrates to mammals. However, it remains unclear how Notch signaling regulates neuronal plasticity, and whether the transcriptional regulator and canonical pathway effector RBP-J plays a role. Here, we report that conditional disruption of RBP-J in the postnatal hippocampus leads to defects in long-term potentiation, long-term depression, and in learning and memory. Using gene expression profiling and chromatin immunoprecipitation, we identified two GABA transporters, GAT2 and BGT1, as putative Notch/RBP-J pathway targets, which may function downstream of RBP-J to limit the accumulation of GABA in the Schaffer collateral pathway. Our results reveal an essential role for canonical Notch/RBP-J signaling in hippocampal synaptic plasticity and suggest that role, at least in part, is mediated by the regulation of GABAergic signaling.

  6. Short DNA sequences inserted for gene targeting can accidentally interfere with off-target gene expression.

    PubMed

    Meier, Ingo D; Bernreuther, Christian; Tilling, Thomas; Neidhardt, John; Wong, Yong Wee; Schulze, Christian; Streichert, Thomas; Schachner, Melitta

    2010-06-01

    Targeting of genes in mice, a key approach to study development and disease, often leaves a neo cassette, loxP, or FRT sites inserted in the mouse genome. Insertion of neo can influence the expression of neighboring genes, but similar effects have not been reported for loxP sites. We therefore performed microarray analyses of mice in which the Ncam or the Tnr gene were targeted either by insertion of neo or loxP/FRT sites. In the case of Ncam, neo, but not loxP/FRT insertion, led to a 2-fold reduction in mRNA levels of 3 genes located at distances between 0.2 and 3.1 Mb from the target. In contrast, after introduction of loxP/FRT sites into introns of Tnr, we observed a 2.5- to 4-fold reduction in the transcript level of the Gas5 gene, 1.1 Mb away from Tnr, most probably due to disruption of a conserved regulatory element in Tnr. Insertion of short DNA sequences such as loxP/FRT can thus influence off-target mRNA levels if these sites are accidentally placed into regulatory elements. Our results imply that conditional knockout mice should be analyzed for genomic positional side effects that may influence the animals' phenotypes. PMID:20110269

  7. In vivo consequences of deleting EGF repeats 8–12 including the ligand binding domain of mouse Notch1

    PubMed Central

    Ge, Changhui; Liu, Tongyi; Hou, Xinghua; Stanley, Pamela

    2008-01-01

    Background Notch signaling is highly conserved in the metazoa and is critical for many cell fate decisions. Notch activation occurs following ligand binding to Notch extracellular domain. In vitro binding assays have identified epidermal growth factor (EGF) repeats 11 and 12 as the ligand binding domain of Drosophila Notch. Here we show that an internal deletion in mouse Notch1 of EGF repeats 8–12, including the putative ligand binding domain (lbd), is an inactivating mutation in vivo. We also show that maternal and zygotic Notch1lbd/lbd mutant embryos develop through gastrulation to mid-gestation. Results Notch1lbd/lbd embryos died at mid-gestation with a phenotype indistinguishable from Notch1 null mutants. In embryonic stem (ES) cells, Notch1lbd was expressed on the cell surface at levels equivalent to wild type Notch1, but Delta1 binding was reduced to the same level as in Notch1 null cells. In an ES cell co-culture assay, Notch signaling induced by Jagged1 or Delta1 was reduced to a similar level in Notch1lbdand Notch1 null cells. However, the Notch1lbd/lbd allele was expressed similarly to wild type Notch1 in Notch1lbd/lbd ES cells and embryos at E8.75, indicating that Notch1 signaling is not essential for the Notch1 gene to be expressed. In addition, maternal and zygotic Notch1 mutant blastocysts developed through gastrulation. Conclusion Mouse Notch1 lacking the ligand binding domain is expressed at the cell surface but does not signal in response to the canonical Notch ligands Delta1 and Jagged1. Homozygous Notch1lbd/lbd mutant embryos die at ~E10 similar to Notch1 null embryos. While Notch1 is expressed in oocytes and blastocysts, Notch1 signaling via canonical ligands is dispensable during oogenesis, blastogenesis, implantation and gastrulation. PMID:18445292

  8. The Role of Notch in the Cardiovascular System: Potential Adverse Effects of Investigational Notch Inhibitors

    PubMed Central

    Rizzo, Paola; Mele, Donato; Caliceti, Cristiana; Pannella, Micaela; Fortini, Cinzia; Clementz, Anthony George; Morelli, Marco Bruno; Aquila, Giorgio; Ameri, Pietro; Ferrari, Roberto

    2015-01-01

    Targeting the Notch pathway is a new promising therapeutic approach for cancer patients. Inhibition of Notch is effective in the oncology setting because it causes a reduction of highly proliferative tumor cells and it inhibits survival of cancer stem cells, which are considered responsible for tumor recurrence and metastasis. Additionally, since Delta-like ligand 4 (Dll4)-activated Notch signaling is a major modulator of angiogenesis, anti-Dll4 agents are being investigated to reduce vascularization of the tumor. Notch plays a major role in the heart during the development and, after birth, in response to cardiac damage. Therefore, agents used to inhibit Notch in the tumors (gamma secretase inhibitors and anti-Dll4 agents) could potentially affect myocardial repair. The past experience with trastuzumab and other tyrosine kinase inhibitors used for cancer therapy demonstrates that the possible cardiotoxicity of agents targeting shared pathways between cancer and heart and the vasculature should be considered. To date, Notch inhibition in cancer patients has resulted only in mild gastrointestinal toxicity. Little is known about the potential long-term cardiotoxicity associated to Notch inhibition in cancer patients. In this review, we will focus on mechanisms through which inhibition of Notch signaling could lead to cardiomyocytes and endothelial dysfunctions. These adverse effects could contrast with the benefits of therapeutic responses in cancer cells during times of increased cardiac stress and/or in the presence of cardiovascular risk factor. PMID:25629006

  9. A dual role for NOTCH signaling in joint cartilage maintenance and osteoarthritis.

    PubMed

    Liu, Zhaoyang; Chen, Jianquan; Mirando, Anthony J; Wang, Cuicui; Zuscik, Michael J; O'Keefe, Regis J; Hilton, Matthew J

    2015-07-21

    Loss of NOTCH signaling in postnatal murine joints results in osteoarthritis, indicating a requirement for NOTCH during maintenance of joint cartilage. However, NOTCH signaling components are substantially increased in abundance in posttraumatic osteoarthritis in humans and mice, suggesting either a reparative or a pathological role for NOTCH activation in osteoarthritis. We investigated a potential dual role for NOTCH in joint maintenance and osteoarthritis by generating two mouse models overexpressing the NOTCH1 intracellular domain (NICD) within postnatal joint cartilage. The first mouse model exhibited sustained NOTCH activation to resemble pathological NOTCH signaling, whereas the second model had transient NOTCH activation, which more closely reflected physiological NOTCH signaling. Sustained NOTCH signaling in joint cartilage led to an early and progressive osteoarthritic-like pathology, whereas transient NOTCH activation enhanced the synthesis of cartilage matrix and promoted joint maintenance under normal physiological conditions. Through RNA-sequencing, immunohistochemical, and biochemical approaches, we identified several targets that could be responsible for NOTCH-mediated cartilage degradation, fibrosis, and osteoarthritis progression. These targets included components of the interleukin-6 (IL-6)-signal transducer and activator of transcription 3 (STAT3) and mitogen-activated protein kinase signaling pathways, which may also contribute to the posttraumatic development of osteoarthritis. Together, these data suggest a dual role for the NOTCH pathway in joint cartilage, and they identify downstream effectors of NOTCH signaling as potential targets for disease-modifying osteoarthritis drugs.

  10. Notch signaling in the brain: in good and bad times.

    PubMed

    Alberi, Lavinia; Hoey, Sarah E; Brai, Emanuele; Scotti, Alessandra L; Marathe, Swananda

    2013-06-01

    Notch signaling is an evolutionarily conserved pathway, which is fundamental for neuronal development and specification. In the last decade, increasing evidence has pointed out an important role of this pathway beyond embryonic development, indicating that Notch also displays a critical function in the mature brain of vertebrates and invertebrates. This pathway appears to be involved in neural progenitor regulation, neuronal connectivity, synaptic plasticity and learning/memory. In addition, Notch appears to be aberrantly regulated in neurodegenerative diseases, including Alzheimer's disease and ischemic injury. The molecular mechanisms by which Notch displays these functions in the mature brain are not fully understood, but are currently the subject of intense research. In this review, we will discuss old and novel Notch targets and molecular mediators that contribute to Notch function in the mature brain and will summarize recent findings that explore the two facets of Notch signaling in brain physiology and pathology.

  11. ChIP-BIT: Bayesian inference of target genes using a novel joint probabilistic model of ChIP-seq profiles.

    PubMed

    Chen, Xi; Jung, Jin-Gyoung; Shajahan-Haq, Ayesha N; Clarke, Robert; Shih, Ie-Ming; Wang, Yue; Magnani, Luca; Wang, Tian-Li; Xuan, Jianhua

    2016-04-20

    Chromatin immunoprecipitation with massively parallel DNA sequencing (ChIP-seq) has greatly improved the reliability with which transcription factor binding sites (TFBSs) can be identified from genome-wide profiling studies. Many computational tools are developed to detect binding events or peaks, however the robust detection of weak binding events remains a challenge for current peak calling tools. We have developed a novel Bayesian approach (ChIP-BIT) to reliably detect TFBSs and their target genes by jointly modeling binding signal intensities and binding locations of TFBSs. Specifically, a Gaussian mixture model is used to capture both binding and background signals in sample data. As a unique feature of ChIP-BIT, background signals are modeled by a local Gaussian distribution that is accurately estimated from the input data. Extensive simulation studies showed a significantly improved performance of ChIP-BIT in target gene prediction, particularly for detecting weak binding signals at gene promoter regions. We applied ChIP-BIT to find target genes from NOTCH3 and PBX1 ChIP-seq data acquired from MCF-7 breast cancer cells. TF knockdown experiments have initially validated about 30% of co-regulated target genes identified by ChIP-BIT as being differentially expressed in MCF-7 cells. Functional analysis on these genes further revealed the existence of crosstalk between Notch and Wnt signaling pathways.

  12. Increasing Notch signaling antagonizes PRC2-mediated silencing to promote reprograming of germ cells into neurons

    PubMed Central

    Seelk, Stefanie; Adrian-Kalchhauser, Irene; Hargitai, Balázs; Hajduskova, Martina; Gutnik, Silvia; Tursun, Baris; Ciosk, Rafal

    2016-01-01

    Cell-fate reprograming is at the heart of development, yet very little is known about the molecular mechanisms promoting or inhibiting reprograming in intact organisms. In the C. elegans germline, reprograming germ cells into somatic cells requires chromatin perturbation. Here, we describe that such reprograming is facilitated by GLP-1/Notch signaling pathway. This is surprising, since this pathway is best known for maintaining undifferentiated germline stem cells/progenitors. Through a combination of genetics, tissue-specific transcriptome analysis, and functional studies of candidate genes, we uncovered a possible explanation for this unexpected role of GLP-1/Notch. We propose that GLP-1/Notch promotes reprograming by activating specific genes, silenced by the Polycomb repressive complex 2 (PRC2), and identify the conserved histone demethylase UTX-1 as a crucial GLP-1/Notch target facilitating reprograming. These findings have wide implications, ranging from development to diseases associated with abnormal Notch signaling. DOI: http://dx.doi.org/10.7554/eLife.15477.001 PMID:27602485

  13. Regulation of dendritic-cell differentiation by bone marrow stroma via different Notch ligands

    PubMed Central

    Cheng, Pingyan; Nefedova, Yulia; Corzo, Cesar A.; Gabrilovich, Dmitry I.

    2007-01-01

    Notch is a major factor mediating interaction between hematopoietic progenitor cells (HPCs) and bone marrow stroma (BMS). However its contribution to dendritic cell (DC) differentiation is controversial. We found that main Notch ligands Delta-1 and Jagged-1 had the opposite effect on DC differentiation. Delta-1 promoted generation of fully differentiated DCs, whereas Jagged-1 stimulated accumulation of DC precursors but prevented their transition to terminally differentiated DCs. BMS expressed a substantially higher level of Jagged-1 than Delta-1. Just the opposite expression pattern was observed in spleen stroma (SS). The BMS effect on DC differentiation was similar to that of Jagged-1, whereas the effect of SS was similar to the effect of Delta-1. Down-regulation of Jagged-1 in BMS substantially increased DC differentiation. Experiments in vivo with adoptive transfer of DC precursors further supported the different roles of BMS and SS in DC development. Jagged-1 and Delta-1 equally activated CBF-1/RBPJκ transcription factor, which is a major Notch target. However, they produced a different pattern of activation of Notch target gene Hes1. Overexpression of Hes1 resulted in increased DC differentiation from HPCs. Thus, this study not only revealed the different role of Notch ligands in DC differentiation but also may provide a new insight into regulation of DC differentiation by BMS. PMID:16973960

  14. Regulation of a Notch3-Hes1 pathway and protective effect by a tocopherol-omega alkanol chain derivative in muscle atrophy.

    PubMed

    von Grabowiecki, Yannick; Licona, Cynthia; Palamiuc, Lavinia; Abreu, Paula; Vidimar, Vania; Coowar, Djalil; Mellitzer, Georg; Gaiddon, Christian

    2015-01-01

    Muscular atrophy, a physiopathologic process associated with severe human diseases such as amyotrophic lateral sclerosis (ALS) or cancer, has been linked to reactive oxygen species (ROS) production. The Notch pathway plays a role in muscle development and in muscle regeneration upon physical injury. In this study, we explored the possibility that the Notch pathway participates in the ROS-related muscular atrophy occurring in cancer-associated cachexia and ALS. We also tested whether hybrid compounds of tocopherol, harboring antioxidant activity, and the omega-alkanol chain, presenting cytoprotective activity, might reduce muscle atrophy and impact the Notch pathway. We identified one tocopherol-omega alkanol chain derivative, AGT251, protecting myoblastic cells against known cytotoxic agents. We showed that this compound presenting antioxidant activity counteracts the induction of the Notch pathway by cytotoxic stress, leading to a decrease of Notch1 and Notch3 expression. At the functional level, these regulations correlated with a repression of the Notch target gene Hes1 and the atrophy/remodeling gene MuRF1. Importantly, we also observed an induction of Notch3 and Hes1 expression in two murine models of muscle atrophy: a doxorubicin-induced cachexia model and an ALS murine model expressing mutated superoxide dismutase 1. In both models, the induction of Notch3 and Hes1 were partially opposed by AGT251, which correlated with ameliorations in body and muscle weight, reduction of muscular atrophy markers, and improved survival. Altogether, we identified a compound of the tocopherol family that protects against muscle atrophy in various models, possibly through the regulation of the Notch pathway.

  15. Regulation of a Notch3-Hes1 pathway and protective effect by a tocopherol-omega alkanol chain derivative in muscle atrophy.

    PubMed

    von Grabowiecki, Yannick; Licona, Cynthia; Palamiuc, Lavinia; Abreu, Paula; Vidimar, Vania; Coowar, Djalil; Mellitzer, Georg; Gaiddon, Christian

    2015-01-01

    Muscular atrophy, a physiopathologic process associated with severe human diseases such as amyotrophic lateral sclerosis (ALS) or cancer, has been linked to reactive oxygen species (ROS) production. The Notch pathway plays a role in muscle development and in muscle regeneration upon physical injury. In this study, we explored the possibility that the Notch pathway participates in the ROS-related muscular atrophy occurring in cancer-associated cachexia and ALS. We also tested whether hybrid compounds of tocopherol, harboring antioxidant activity, and the omega-alkanol chain, presenting cytoprotective activity, might reduce muscle atrophy and impact the Notch pathway. We identified one tocopherol-omega alkanol chain derivative, AGT251, protecting myoblastic cells against known cytotoxic agents. We showed that this compound presenting antioxidant activity counteracts the induction of the Notch pathway by cytotoxic stress, leading to a decrease of Notch1 and Notch3 expression. At the functional level, these regulations correlated with a repression of the Notch target gene Hes1 and the atrophy/remodeling gene MuRF1. Importantly, we also observed an induction of Notch3 and Hes1 expression in two murine models of muscle atrophy: a doxorubicin-induced cachexia model and an ALS murine model expressing mutated superoxide dismutase 1. In both models, the induction of Notch3 and Hes1 were partially opposed by AGT251, which correlated with ameliorations in body and muscle weight, reduction of muscular atrophy markers, and improved survival. Altogether, we identified a compound of the tocopherol family that protects against muscle atrophy in various models, possibly through the regulation of the Notch pathway. PMID:25326132

  16. Prolactin signaling enhances colon cancer stemness by modulating Notch signaling in a Jak2-STAT3/ERK manner.

    PubMed

    Neradugomma, Naveen K; Subramaniam, Dharmalingam; Tawfik, Ossama W; Goffin, Vincent; Kumar, T Rajendra; Jensen, Roy A; Anant, Shrikant

    2014-04-01

    Prolactin (PRL) is a secretory cytokine produced by various tissues. Binding to the cognate PRL receptor (PRLR), it activates intracellular signaling via janus kinase (JAK), extracellular signal-regulated kinase (ERK) and signal transducer and activator of transcription (STAT) proteins. PRL regulates diverse activities under normal and abnormal conditions, including malignancies. Previous clinical data suggest serum PRL levels are elevated in colorectal cancer (CRC) patients. In this study, we first determined the expression of PRL and PRLR in colon cancer tissue and cell lines. Higher levels of PRLR expression were observed in the cancer cells and cell lines compared with normal colonic epithelial cells. Incubation of colon cancer cells with PRL-induced JAK2, STAT3 and ERK1/2 phosphorylation and increased expression of Jagged 1, which is a Notch-1 receptor ligand. Notch signaling regulates CRC stem cell population. We observed increased accumulation of the cleaved/active form of Notch-1 receptor (Notch intracellular domain) and increased expression of Notch responsive genes HEY1, HES1 and stem cell marker genes DCLK1, LGR5, ALDH1 and CD44. Finally, inhibiting PRL induced JAK2-STAT3 and JAK2-ERK1/2 using AG490 and PD98059, respectively, leads to complete abrogation of Notch signaling, suggesting a role for this pathway in regulating CRC stem cells. Together, our results demonstrate that cytokine signaling induced by PRL is active in colorectal cancers and may provide a novel target for therapeutic intervention.

  17. Notch signaling drives multiple myeloma induced osteoclastogenesis

    PubMed Central

    Colombo, Michela; Thümmler, Katja; Mirandola, Leonardo; Garavelli, Silvia; Todoerti, Katia; Apicella, Luana; Lazzari, Elisa; Lancellotti, Marialuigia; Platonova, Natalia; Akbar, Moeed; Chiriva-Internati, Maurizio; Soutar, Richard; Neri, Antonino; Goodyear, Carl S.; Chiaramonte, Raffaella

    2014-01-01

    Multiple myeloma (MM) is closely associated with bone destruction. Once migrated to the bone marrow, MM cells unbalance bone formation and resorption via the recruitment and maturation of osteoclast precursors. The Notch pathway plays a key role in different types of cancer and drives several biological processes relevant in MM, including cell localization within the bone marrow, proliferation, survival and pharmacological resistance. Here we present evidences that MM can efficiently drive osteoclastogenesis by contemporaneously activating Notch signaling on tumor cells and osteoclasts through the aberrant expression of Notch ligands belonging to the Jagged family. Active Notch signaling in MM cells induces the secretion of the key osteoclastogenic factor, RANKL, which can be boosted in the presence of stromal cells. In turn, MM cells-derived RANKL causes the upregulation of its receptor, RANK, and Notch2 in pre-osteoclasts. Notch2 stimulates osteoclast differentiation by promoting autocrine RANKL signaling. Finally, MM cells through Jagged ligands expression can also activate Notch signaling in pre-osteoclast by direct contact. Such synergism between tumor cells and pre-osteoclasts in MM-induced osteoclastogenesis can be disrupted by silencing tumor-derived Jagged1 and 2. These results make the Jagged ligands new promising therapeutic targets in MM to contrast bone disease and the associated co-morbidities. PMID:25257302

  18. NOTCHing the bone: Insights into multi-functionality

    PubMed Central

    Engin, Feyza; Lee, Brendan

    2010-01-01

    Evolutionarily conserved Notch signaling plays a critical role during embryonic and postnatal life. The importance of Notch signaling in the determination of cell fate, and the spatio-temporal regulation of proliferation, differentiation and apoptosis has been demonstrated in various different organ systems. However, how Notch signaling affects the bone development was unknown until now. The in vivo effects of Notch signaling in lineage commitment, bone formation and bone resorption were demonstrated in recent studies. In addition to regulation of osteoblastogenesis, osteoblast directed osteoclastogenesis by Notch signaling revealed a dimorphic effect for this signaling pathway providing another example of such in bone development. Moreover, identification of the cross-talk between the hematopoietic stem cell niche and osteoblasts through Notch signaling also suggested another important role for Notch signaling, i.e., the coupling of cellular components of the bone microenvironment. The association between the gain and loss of function of Notch activity in bone pathology highlights Notch as a potentially novel therapeutic target for the treatment of metabolic bone disease and bone cancer. In this review, we will focus primarily on the regulation of bone cells, i.e., osteoblasts and osteoclasts by Notch signaling. We will also review the importance of Notch in specifying bone-hematopoietic stem cell niche interactions within the bone microenvironment. Finally, we will discuss potential clinical implications and future directions for this field. PMID:19520195

  19. Quantification of gamma-secretase modulation differentiates inhibitor compound selectivity between two substrates Notch and amyloid precursor protein

    PubMed Central

    Yang, Ting; Arslanova, Dilyara; Gu, Yongli; Augelli-Szafran, Corinne; Xia, Weiming

    2008-01-01

    Background Deposition of amyloid-β protein (Aβ) is a major pathological hallmark of Alzheimer's disease (AD). Aβ is generated from γ-secretase cleavage of amyloid precursor protein (APP). In addition to APP, γ-secretase also cleaves other type I integral membrane proteins, including the Notch receptor, a key molecule involved in embryonic development. Results To explore selective γ-secretase inhibitors, a combination of five methods was used to systematically determine these inhibitors' profiles on the γ-secretase cleavage of APP and Notch. When two potent γ-secretase inhibitors, compound E (cpd E) and DAPT, were used in a conventional in vitro γ-secretase activity assay, cpd E completely blocked Aβ generation from the cleavage of substrate APP C100, but only had a minor effect on Notch cleavage and NICD generation. Next, cpd E and DAPT were applied to HEK293 cells expressing a truncated Notch substrate NotchΔE. Both cpd E and DAPT were more potent in blocking Aβ generation than NICD generation. Third, a reporter construct was created that carried the NICD targeting promoter with three Su(H) binding sequences followed by the luciferase gene. We found that the inhibition of NICD generation by cpd E and DAPT was consistent with the reduced expression of luciferase gene driven by this Notch targeting promoter. Fourth, levels of "Notch-Aβ-like" (Nβ*) peptide derived from two previously reported chimeric APP with its transmembrane domain or the juxtamembrane portion replaced by the Notch sequence were quantified. Measurement of Nβ* peptides by ELISA confirmed that EC50's of cpd E were much higher for Nβ* than Aβ. Finally, the expression levels of Notch target gene her6 in cpd E or DAPT-treated zebrafish were correlated with the degree of tail curvature due to defective somitogenesis, a well characterized Notch phenotype in zebrafish. Conclusion Our ELISA-based quantification of Aβ and Nβ* in combination with the test in zebrafish provides a novel

  20. Spatiotemporal gene expression targeting with the TARGET and gene-switch systems in Drosophila.

    PubMed

    McGuire, Sean E; Mao, Zhengmei; Davis, Ronald L

    2004-02-17

    Targeted gene expression has become a standard technique for the study of biological questions in Drosophila. Until recently, transgene expression could be targeted in the dimension of either time or space, but not both. Several new systems have recently been developed to direct transgene expression simultaneously in both time and space. We describe here two such systems that we developed in our laboratory. The first system provides a general method for temporal and regional gene expression targeting (TARGET) with the conventional GAL4-upstream activator sequence (UAS) system and a temperature-sensitive GAL80 molecule, which represses GAL4 transcriptional activity at permissive temperatures. The second system, termed Gene-Switch, is based on a GAL4-progesterone receptor chimera that is hormone-inducible. We have used both systems for simultaneous spatial and temporal rescue of memory dysfunction in the rutabaga (rut) memory mutant of Drosophila. In this protocol, we provide guidelines for the use of these two novel systems, which should have general utility in studying Drosophila biology and in using the fly as a model for human disease. PMID:14970377

  1. Competition between Jagged-Notch and Endothelin1 Signaling Selectively Restricts Cartilage Formation in the Zebrafish Upper Face

    PubMed Central

    Barske, Lindsey; Askary, Amjad; Zuniga, Elizabeth; Balczerski, Bartosz; Bump, Paul; Nichols, James T.; Crump, J. Gage

    2016-01-01

    The intricate shaping of the facial skeleton is essential for function of the vertebrate jaw and middle ear. While much has been learned about the signaling pathways and transcription factors that control facial patterning, the downstream cellular mechanisms dictating skeletal shapes have remained unclear. Here we present genetic evidence in zebrafish that three major signaling pathways − Jagged-Notch, Endothelin1 (Edn1), and Bmp − regulate the pattern of facial cartilage and bone formation by controlling the timing of cartilage differentiation along the dorsoventral axis of the pharyngeal arches. A genomic analysis of purified facial skeletal precursors in mutant and overexpression embryos revealed a core set of differentiation genes that were commonly repressed by Jagged-Notch and induced by Edn1. Further analysis of the pre-cartilage condensation gene barx1, as well as in vivo imaging of cartilage differentiation, revealed that cartilage forms first in regions of high Edn1 and low Jagged-Notch activity. Consistent with a role of Jagged-Notch signaling in restricting cartilage differentiation, loss of Notch pathway components resulted in expanded barx1 expression in the dorsal arches, with mutation of barx1 rescuing some aspects of dorsal skeletal patterning in jag1b mutants. We also identified prrx1a and prrx1b as negative Edn1 and positive Bmp targets that function in parallel to Jagged-Notch signaling to restrict the formation of dorsal barx1+ pre-cartilage condensations. Simultaneous loss of jag1b and prrx1a/b better rescued lower facial defects of edn1 mutants than loss of either pathway alone, showing that combined overactivation of Jagged-Notch and Bmp/Prrx1 pathways contribute to the absence of cartilage differentiation in the edn1 mutant lower face. These findings support a model in which Notch-mediated restriction of cartilage differentiation, particularly in the second pharyngeal arch, helps to establish a distinct skeletal pattern in the upper

  2. Sox9 mediates Notch1-induced mesenchymal features in lung adenocarcinoma.

    PubMed

    Capaccione, Kathleen M; Hong, Xuehui; Morgan, Katherine M; Liu, Wenyu; Bishop, J Michael; Liu, LianXin; Markert, Elke; Deen, Malik; Minerowicz, Christine; Bertino, Joseph R; Allen, Thaddeus; Pine, Sharon R

    2014-06-15

    Sox9 has gained increasing importance both functionally and as a prognostic factor in cancer. We demonstrate a functional role for Sox9 in inducing a mesenchymal phenotype in lung ADC. We show that Sox9 mRNA and protein are overexpressed in lung ADC, particularly those with KRAS mutations. Sox9 expression correlated with the Notch target gene Hes1, and numerous other Notch pathway components. We observed that Sox9 is a potent inducer of lung cancer cell motility and invasion, and a negative regulator of E-cadherin, a key protein that is lost during epithelial-mesenchymal transition (EMT). Moreover, we show that Notch1 signaling directly regulates Sox9 expression through a SOX9 promoter binding site, independently of the TGF-β pathway, and that Sox9 participates in Notch-1 induced cell motility, cell invasion, and loss of E-cadherin expression. Together, the results identify a new functional role for a Notch1-Sox9 signaling axis in lung ADC that may explain the correlation of Sox9 with tumor progression, higher tumor grade, and poor lung cancer survival. In addition to Notch and TGF-β, Sox9 also acts downstream of NF-κB, BMP, EGFR, and Wnt/β-catenin signaling. Thus, Sox9 could potentially act as a hub to mediate cross-talk among key oncogenic pathways in lung ADC. Targeting Sox9 expression or transcriptional activity could potentially reduce resistance to targeted therapy for lung ADC caused by pathway redundancy. PMID:25004243

  3. Targeted gene knockout in chickens mediated by TALENs.

    PubMed

    Park, Tae Sub; Lee, Hong Jo; Kim, Ki Hyun; Kim, Jin-Soo; Han, Jae Yong

    2014-09-01

    Genetically modified animals are used for industrial applications as well as scientific research, and studies on these animals contribute to a better understanding of biological mechanisms. Gene targeting techniques have been developed to edit specific gene loci in the genome, but the conventional strategy of homologous recombination with a gene-targeted vector has low efficiency and many technical complications. Here, we generated specific gene knockout chickens through the use of transcription activator-like effector nuclease (TALEN)-mediated gene targeting. In this study, we accomplished targeted knockout of the ovalbumin (OV) gene in the chicken primordial germ cells, and OV gene mutant offspring were generated through test-cross analysis. TALENs successfully induced nucleotide deletion mutations of ORF shifts, resulting in loss of chicken OV gene function. Our results demonstrate that the TALEN technique used in the chicken primordial germ cell line is a powerful strategy to create specific genome-edited chickens safely for practical applications. PMID:25139993

  4. Epidermal stem cells (ESCs) accelerate diabetic wound healing via the Notch signalling pathway

    PubMed Central

    Yang, Rong-Hua; Qi, Shao-Hai; Shu, Bin; Ruan, Shu-Bin; Lin, Ze-Peng; Lin, Yan; Shen, Rui; Zhang, Feng-Gang; Chen, Xiao-Dong; Xie, Ju-Lin

    2016-01-01

    Chronic, non-healing wounds are a major complication of diabetes. Recently, various cell therapies have been reported for promotion of diabetic wound healing. Epidermal stem cells (ESCs) are considered a powerful tool for tissue therapy. However, the effect and the mechanism of the therapeutic properties of ESCs in the diabetic wound healing are unclear. Herein, to determine the ability of ESCs to diabetic wound healing, a dorsal skin defect in a streptozotocin (STZ)-induced diabetes mellitus (DM) mouse model was used. ESCs were isolated from mouse skin. We found that both the mRNA and protein levels of a Notch ligand Jagged1 (Jag1), Notch1 and Notch target gene Hairy Enhancer of Split-1 (Hes1) were significantly increased at the wound margins. In addition, we observed that Jag1 was high expressed in ESCs. Overexpression of Jag1 promotes ESCs migration, whereas knockdown Jag1 resulted in a significant reduction in ESCs migration in vitro. Importantly, Jag1 overexpression improves diabetic wound healing in vivo. These results provide evidence that ESCs accelerate diabetic wound healing via the Notch signalling pathway, and provide a promising potential for activation of the Notch pathway for the treatment of diabetic wound. PMID:27129289

  5. Epidermal stem cells (ESCs) accelerate diabetic wound healing via the Notch signalling pathway.

    PubMed

    Yang, Rong-Hua; Qi, Shao-Hai; Shu, Bin; Ruan, Shu-Bin; Lin, Ze-Peng; Lin, Yan; Shen, Rui; Zhang, Feng-Gang; Chen, Xiao-Dong; Xie, Ju-Lin

    2016-08-01

    Chronic, non-healing wounds are a major complication of diabetes. Recently, various cell therapies have been reported for promotion of diabetic wound healing. Epidermal stem cells (ESCs) are considered a powerful tool for tissue therapy. However, the effect and the mechanism of the therapeutic properties of ESCs in the diabetic wound healing are unclear. Herein, to determine the ability of ESCs to diabetic wound healing, a dorsal skin defect in a streptozotocin (STZ)-induced diabetes mellitus (DM) mouse model was used. ESCs were isolated from mouse skin. We found that both the mRNA and protein levels of a Notch ligand Jagged1 (Jag1), Notch1 and Notch target gene Hairy Enhancer of Split-1 (Hes1) were significantly increased at the wound margins. In addition, we observed that Jag1 was high expressed in ESCs. Overexpression of Jag1 promotes ESCs migration, whereas knockdown Jag1 resulted in a significant reduction in ESCs migration in vitro Importantly, Jag1 overexpression improves diabetic wound healing in vivo These results provide evidence that ESCs accelerate diabetic wound healing via the Notch signalling pathway, and provide a promising potential for activation of the Notch pathway for the treatment of diabetic wound. PMID:27129289

  6. Structural and mechanistic insights into cooperative assembly of dimeric Notch transcription complexes

    SciTech Connect

    Arnett, Kelly L.; Hass, Matthew; McArthur, Debbie G.; Ilagan, Ma Xenia G.; Aster, Jon C.; Kopan, Raphael; Blacklow, Stephen C.

    2010-11-12

    Ligand-induced proteolysis of Notch produces an intracellular effector domain that transduces essential signals by regulating the transcription of target genes. This function relies on the formation of transcriptional activation complexes that include intracellular Notch, a Mastermind co-activator and the transcription factor CSL bound to cognate DNA. These complexes form higher-order assemblies on paired, head-to-head CSL recognition sites. Here we report the X-ray structure of a dimeric human Notch1 transcription complex loaded on the paired site from the human HES1 promoter. The small interface between the Notch ankyrin domains could accommodate DNA bending and untwisting to allow a range of spacer lengths between the two sites. Cooperative dimerization occurred on the human and mouse Hes5 promoters at a sequence that diverged from the CSL-binding consensus at one of the sites. These studies reveal how promoter organizational features control cooperativity and, thus, the responsiveness of different promoters to Notch signaling.

  7. Endothelial Jarid2/Jumonji is required for normal cardiac development and proper Notch1 expression.

    PubMed

    Mysliwiec, Matthew R; Bresnick, Emery H; Lee, Youngsook

    2011-05-13

    Jarid2/Jumonji critically regulates developmental processes including cardiovascular development. Jarid2 knock-out mice exhibit cardiac defects including hypertrabeculation with noncompaction of the ventricular wall. However, molecular mechanisms underlying Jarid2-mediated cardiac development remain unknown. To determine the cardiac lineage-specific roles of Jarid2, we generated myocardial, epicardial, cardiac neural crest, or endothelial conditional Jarid2 knock-out mice using Cre-loxP technology. Only mice with an endothelial deletion of Jarid2 recapitulate phenotypic defects observed in whole body mutants including hypertrabeculation and noncompaction of the ventricle. To identify potential targets of Jarid2, combinatorial approaches using microarray and candidate gene analyses were employed on Jarid2 knock-out embryonic hearts. Whole body or endothelial deletion of Jarid2 leads to increased endocardial Notch1 expression in the developing ventricle, resulting in increased Notch1-dependent signaling to the adjacent myocardium. Using quantitative chromatin immunoprecipitation analysis, Jarid2 was found to occupy a specific region on the endogenous Notch1 locus. We propose that failure to properly regulate Notch signaling in Jarid2 mutants likely leads to the defects in the developing ventricular chamber. The identification of Jarid2 as a potential regulator of Notch1 signaling has broad implications for many cellular processes including development, stem cell maintenance, and tumor formation.

  8. Dephosphorylated parafibromin is a transcriptional coactivator of the Wnt/Hedgehog/Notch pathways

    PubMed Central

    Kikuchi, Ippei; Takahashi-Kanemitsu, Atsushi; Sakiyama, Natsuki; Tang, Chao; Tang, Pei-Jung; Noda, Saori; Nakao, Kazuki; Kassai, Hidetoshi; Sato, Toshiro; Aiba, Atsu; Hatakeyama, Masanori

    2016-01-01

    Evolutionally conserved Wnt, Hedgehog (Hh) and Notch morphogen pathways play essential roles in the development, homeostasis and pathogenesis of multicellular organisms. Nevertheless, mechanisms that intracellularly coordinate these signal inputs remain poorly understood. Here we found that parafibromin, a component of the PAF complex, competitively interacts with β-catenin and Gli1, thereby potentiating transactivation of Wnt- and Hh-target genes in a mutually exclusive manner. Parafibromin also binds to the Notch intracellular domain (NICD), enabling concerted activation of Wnt- and Notch-target genes. The transcriptional platform function of parafibromin is potentiated by tyrosine dephosphorylation, mediated by SHP2 phosphatase, while it is attenuated by tyrosine phosphorylation, mediated by PTK6 kinase. Consequently, acute loss of parafibromin in mice disorganizes the normal epithelial architecture of the intestine, which requires coordinated activation/inactivation of Wnt, Hh and/or Notch signalling. Parafibromin integrates and converts signals conveyed by these morphogen pathways into appropriate transcriptional outputs in a tyrosine phosphorylation/dephosphorylation-regulated manner. PMID:27650679

  9. Dephosphorylated parafibromin is a transcriptional coactivator of the Wnt/Hedgehog/Notch pathways.

    PubMed

    Kikuchi, Ippei; Takahashi-Kanemitsu, Atsushi; Sakiyama, Natsuki; Tang, Chao; Tang, Pei-Jung; Noda, Saori; Nakao, Kazuki; Kassai, Hidetoshi; Sato, Toshiro; Aiba, Atsu; Hatakeyama, Masanori

    2016-09-21

    Evolutionally conserved Wnt, Hedgehog (Hh) and Notch morphogen pathways play essential roles in the development, homeostasis and pathogenesis of multicellular organisms. Nevertheless, mechanisms that intracellularly coordinate these signal inputs remain poorly understood. Here we found that parafibromin, a component of the PAF complex, competitively interacts with β-catenin and Gli1, thereby potentiating transactivation of Wnt- and Hh-target genes in a mutually exclusive manner. Parafibromin also binds to the Notch intracellular domain (NICD), enabling concerted activation of Wnt- and Notch-target genes. The transcriptional platform function of parafibromin is potentiated by tyrosine dephosphorylation, mediated by SHP2 phosphatase, while it is attenuated by tyrosine phosphorylation, mediated by PTK6 kinase. Consequently, acute loss of parafibromin in mice disorganizes the normal epithelial architecture of the intestine, which requires coordinated activation/inactivation of Wnt, Hh and/or Notch signalling. Parafibromin integrates and converts signals conveyed by these morphogen pathways into appropriate transcriptional outputs in a tyrosine phosphorylation/dephosphorylation-regulated manner.

  10. Notch signaling in prostate cancer: refining a therapeutic opportunity

    PubMed Central

    Su, Qingtai; Xin, Li

    2016-01-01

    Summary Notch is an evolutionarily conserved signaling pathway that plays a critical role in specifying cell fate and regulating tissue homeostasis and carcinogenesis. Studies using organ cultures and genetically engineered mouse models have demonstrated that Notch signaling regulates prostate development and homeostasis. However, the role of the Notch signaling pathway in prostate cancer remains inconclusive. Many published studies have documented consistent deregulation of major Notch signaling components in human prostate cancer cell lines, mouse models for prostate cancers, and human prostate cancer specimens at both the mRNA and the protein levels. However, functional studies in human cancer cells by modulation of Notch pathway elements suggest both tumor suppressive and oncogenic roles of Notch. These controversies may originate from our inadequate understanding of the regulation of Notch signaling under versatile genetic contexts, and reflect the multifaceted and pleiotropic roles of Notch in regulating different aspects of prostate cancer cell biology, such as proliferation, metastasis, and chemo-resistance. Future comprehensive studies using various mouse models for prostate cancer may help clarify the role of Notch signaling in prostate cancer and provide a solid basis for determining whether and how Notch should be employed as a therapeutic target for prostate cancer. PMID:26521657

  11. High throughput kinase inhibitor screens reveal TRB3 and MAPK-ERK/TGFβ pathways as fundamental Notch regulators in breast cancer.

    PubMed

    Izrailit, Julia; Berman, Hal K; Datti, Alessandro; Wrana, Jeffrey L; Reedijk, Michael

    2013-01-29

    Expression of the Notch ligand Jagged 1 (JAG1) and Notch activation promote poor-prognosis in breast cancer. We used high throughput screens to identify elements responsible for Notch activation in this context. Chemical kinase inhibitor and kinase-specific small interfering RNA libraries were screened in a breast cancer cell line engineered to report Notch. Pathway analyses revealed MAPK-ERK signaling to be the predominant JAG1/Notch regulator and this was supported by gene set enrichment analyses in 51 breast cancer cell lines. In accordance with the chemical screen, kinome small interfering RNA high throughput screens identified Tribbles homolog 3 (TRB3), a known regulator of MAPK-ERK, among the most significant hits. We demonstrate that TRB3 is a master regulator of Notch through the MAPK-ERK and TGFβ pathways. Complementary in vitro and in vivo studies underscore the importance of TRB3 for tumor growth. These data demonstrate a dominant role for TRB3 and MAPK-ERK/TGFβ pathways as Notch regulators in breast cancer, establishing TRB3 as a potential therapeutic target.

  12. Involvement of the Notch pathway in terminal astrocytic differentiation: role of PKA.

    PubMed

    Angulo-Rojo, Carla; Manning-Cela, Rebeca; Aguirre, Adán; Ortega, Arturo; López-Bayghen, Esther

    2013-12-23

    The Notch pathway is a highly conserved signaling system essential for modulating neurogenesis and promoting astrogenesis. Similarly, the cAMP signaling cascade can promote astrocytic commitment in several cell culture models, such as the C6 glioma cell line. These cells have the capacity to differentiate into oligodendrocytes or astrocytes, characteristics that allow their use as a glial progenitor model. In this context, we explore here the plausible involvement of cAMP in Notch-dependent signal transactions. The exposure of C6 cells to a non-hydrolysable cAMP analogue resulted in a sustained augmentation of Notch activity, as detected by nuclear translocation of its intracellular domain portion (NICD) and transcriptional activity. The cAMP effect is mediated through the activation of the γ-secretase complex, responsible for Notch cleavage and is sensitive to inhibitors of the cAMP-dependent protein kinase, PKA. As expected, Notch cleavage and nuclear translocation resulted in the up-regulation of the mRNA levels of one of its target genes, the transcription factor Hair and enhancer of split 5. Moreover, the glutamate uptake activity, as well as the expression of astrocytic markers such as glial fibrillary acidic protein, S100β protein and GLAST was also enhanced in cAMP-exposed cells. Our results clearly suggest that during the process of C6 astrocytic differentiation, cAMP activates the PKA/γ-secretase/NICD/RBPJ(κ) pathway and Notch1 expression, leading to transcriptional activation of the genes responsible for glial progenitor cell fate decision.

  13. Involvement of the Notch pathway in terminal astrocytic differentiation: role of PKA

    PubMed Central

    Angulo-Rojo, Carla; Manning-Cela, Rebeca; Aguirre, Adán; Ortega, Arturo; López-Bayghen, Esther

    2013-01-01

    The Notch pathway is a highly conserved signaling system essential for modulating neurogenesis and promoting astrogenesis. Similarly, the cAMP signaling cascade can promote astrocytic commitment in several cell culture models, such as the C6 glioma cell line. These cells have the capacity to differentiate into oligodendrocytes or astrocytes, characteristics that allow their use as a glial progenitor model. In this context, we explore here the plausible involvement of cAMP in Notch-dependent signal transactions. The exposure of C6 cells to a non-hydrolysable cAMP analogue resulted in a sustained augmentation of Notch activity, as detected by nuclear translocation of its intracellular domain portion (NICD) and transcriptional activity. The cAMP effect is mediated through the activation of the γ-secretase complex, responsible for Notch cleavage and is sensitive to inhibitors of the cAMP-dependent protein kinase, PKA. As expected, Notch cleavage and nuclear translocation resulted in the up-regulation of the mRNA levels of one of its target genes, the transcription factor Hair and enhancer of split 5. Moreover, the glutamate uptake activity, as well as the expression of astrocytic markers such as glial fibrillary acidic protein, S100β protein and GLAST was also enhanced in cAMP-exposed cells. Our results clearly suggest that during the process of C6 astrocytic differentiation, cAMP activates the PKA/γ-secretase/NICD/RBPJκ pathway and Notch1 expression, leading to transcriptional activation of the genes responsible for glial progenitor cell fate decision. PMID:24286475

  14. Notch2 activation ameliorates nephrosis

    NASA Astrophysics Data System (ADS)

    Tanaka, Eriko; Asanuma, Katsuhiko; Kim, Eunhee; Sasaki, Yu; Trejo, Juan Alejandro Oliva; Seki, Takuto; Nonaka, Kanae; Asao, Rin; Nagai-Hosoe, Yoshiko; Akiba-Takagi, Miyuki; Hidaka, Teruo; Takagi, Masatoshi; Koyanagi, Akemi; Mizutani, Shuki; Yagita, Hideo; Tomino, Yasuhiko

    2014-02-01

    Activation of Notch1 and Notch2 has been recently implicated in human glomerular diseases. Here we show that Notch2 prevents podocyte loss and nephrosis. Administration of a Notch2 agonistic monoclonal antibody ameliorates proteinuria and glomerulosclerosis in a mouse model of nephrosis and focal segmental glomerulosclerosis. In vitro, the specific knockdown of Notch2 increases apoptosis in damaged podocytes, while Notch2 agonistic antibodies enhance activation of Akt and protect damaged podocytes from apoptosis. Treatment with triciribine, an inhibitor of Akt pathway, abolishes the protective effect of the Notch2 agonistic antibody. We find a positive linear correlation between the number of podocytes expressing activated Notch2 and the number of residual podocytes in human nephrotic specimens. Hence, specific activation of Notch2 rescues damaged podocytes and activating Notch2 may represent a novel clinical strategy for the amelioration of nephrosis and glomerulosclerosis.

  15. Bacteriophage-Derived Vectors for Targeted Cancer Gene Therapy

    PubMed Central

    Pranjol, Md Zahidul Islam; Hajitou, Amin

    2015-01-01

    Cancer gene therapy expanded and reached its pinnacle in research in the last decade. Both viral and non-viral vectors have entered clinical trials, and significant successes have been achieved. However, a systemic administration of a vector, illustrating safe, efficient, and targeted gene delivery to solid tumors has proven to be a major challenge. In this review, we summarize the current progress and challenges in the targeted gene therapy of cancer. Moreover, we highlight the recent developments of bacteriophage-derived vectors and their contributions in targeting cancer with therapeutic genes following systemic administration. PMID:25606974

  16. The matricellular protein CCN3 regulates NOTCH1 signalling in chronic myeloid leukaemia.

    PubMed

    Suresh, Sukanya; McCallum, Lynn; Crawford, Lisa J; Lu, Wan Hua; Sharpe, Daniel J; Irvine, Alexandra E

    2013-11-01

    Deregulated NOTCH1 has been reported in lymphoid leukaemia, although its role in chronic myeloid leukaemia (CML) is not well established. We previously reported BCR-ABL down-regulation of a novel haematopoietic regulator, CCN3, in CML; CCN3 is a non-canonical NOTCH1 ligand. This study characterizes the NOTCH1–CCN3 signalling axis in CML. In K562 cells, BCR-ABL silencing reduced full-length NOTCH1 (NOTCH1-FL) and inhibited the cleavage of NOTCH1 intracellular domain (NOTCH1-ICD), resulting in decreased expression of the NOTCH1 targets c-MYC and HES1. K562 cells stably overexpressing CCN3 (K562/CCN3) or treated with recombinant CCN3(rCCN3) showed a significant reduction in NOTCH1 signalling (> 50% reduction in NOTCH1-ICD, p < 0.05).Gamma secretase inhibitor (GSI), which blocks NOTCH1 signalling, reduced K562/CCN3 colony formation but increased that of K562/control cells. GSI combined with either rCCN3 or imatinib reduced K562 colony formation with enhanced reduction of NOTCH1 signalling observed with combination treatments. We demonstrate an oncogenic role for NOTCH1 in CML and suggest that BCR-ABL disruption of NOTCH1–CCN3 signalling contributes to the pathogenesis of CML.

  17. Tissue-specific targeting of cell fate regulatory genes by E2f factors.

    PubMed

    Julian, L M; Liu, Y; Pakenham, C A; Dugal-Tessier, D; Ruzhynsky, V; Bae, S; Tsai, S-Y; Leone, G; Slack, R S; Blais, A

    2016-04-01

    Cell cycle proteins are important regulators of diverse cell fate decisions, and in this capacity have pivotal roles in neurogenesis and brain development. The mechanisms by which cell cycle regulation is integrated with cell fate control in the brain and other tissues are poorly understood, and an outstanding question is whether the cell cycle machinery regulates fate decisions directly or instead as a secondary consequence of proliferative control. Identification of the genes targeted by E2 promoter binding factor (E2f) transcription factors, effectors of the pRb/E2f cell cycle pathway, will provide essential insights into these mechanisms. We identified the promoter regions bound by three neurogenic E2f factors in neural precursor cells in a genome-wide manner. Through bioinformatic analyses and integration of published genomic data sets we uncovered hundreds of transcriptionally active E2f-bound promoters corresponding to genes that control cell fate processes, including key transcriptional regulators and members of the Notch, fibroblast growth factor, Wnt and Tgf-β signaling pathways. We also demonstrate a striking enrichment of the CCCTC binding factor transcription factor (Ctcf) at E2f3-bound nervous system-related genes, suggesting a potential regulatory co-factor for E2f3 in controlling differentiation. Finally, we provide the first demonstration of extensive tissue specificity among E2f target genes in mammalian cells, whereby E2f3 promoter binding is well conserved between neural and muscle precursors at genes associated with cell cycle processes, but is tissue-specific at differentiation-associated genes. Our findings implicate the cell cycle pathway as a widespread regulator of cell fate genes, and suggest that E2f3 proteins control cell type-specific differentiation programs by regulating unique sets of target genes. This work significantly enhances our understanding of how the cell cycle machinery impacts cell fate and differentiation, and will

  18. Characterization and developmental expression of the amphioxus homolog of Notch (AmphiNotch): evolutionary conservation of multiple expression domains in amphioxus and vertebrates.

    PubMed

    Holland, L Z; Rached, L A; Tamme, R; Holland, N D; Kortschak, D; Inoko, H; Shiina, T; Burgtorf, C; Lardelli, M

    2001-04-15

    Notch encodes a transmembrane protein that functions in intercellular signaling. Although there is one Notch gene in Drosophila, vertebrates have three or more with overlapping patterns of embryonic expression. We cloned the entire 7575-bp coding region of an amphioxus Notch gene (AmphiNotch), encoding 2524 amino acids, and obtained the exon/intron organization from a genomic cosmid clone. Southern blot and PCR data indicate that AmphiNotch is the only Notch gene in amphioxus. AmphiNotch, like Drosophila Notch and vertebrate Notch1 and Notch2, has 36 EGF repeats, 3 Notch/lin-12 repeats, a transmembrane region, and 6 ankyrin repeats. Phylogenetic analysis places it at the base of all the vertebrate genes, suggesting it is similar to the ancestral gene from which the vertebrate Notch family genes evolved. AmphiNotch is expressed in all three embryonic germ layers in spatiotemporal patterns strikingly similar to those of all the vertebrate homologs combined. In the developing nerve cord, AmphiNotch is first expressed in the posteriormost part of the neural plate, then it becomes more broadly expressed and later is localized dorsally in the anteriormost part of the nerve cord corresponding to the diencephalon. In late embryos and larvae, AmphiNotch is also expressed in parts of the pharyngeal endoderm, in the anterior gut diverticulum, and, like AmphiPax2/5/8, in the rudiment of Hatschek's kidney. A comparison with Notch1 and Pax5 and Pax8 expression in the embryonic mouse kidney helps support homology of the amphioxus and vertebrate kidneys. AmphiNotch is also an early marker for presumptive mesoderm, transcripts first being detectable at the gastrula stage in a ring of mesendoderm just inside the blastopore and subsequently in the posterior mesoderm, notochord, and somites. As in sea urchins and vertebrates, these domains of AmphiNotch expression overlap with those of several Wnt genes and brachyury. These relationships suggest that amphioxus shares with other

  19. Transcriptional targeting of tumor endothelial cells for gene therapy

    PubMed Central

    Dong, Zhihong; Nör, Jacques E.

    2009-01-01

    It is well known that angiogenesis plays a critical role in the pathobiology of tumors. Recent clinical trials have shown that inhibition of angiogenesis can be an effective therapeutic strategy for patients with cancer. However, one of the outstanding issues in anti-angiogenic treatment for cancer is the development of toxicities related to off-target effects of drugs. Transcriptional targeting of tumor endothelial cells involves the use of specific promoters for selective expression of therapeutic genes in the endothelial cells lining the blood vessels of tumors. Recently, several genes that are expressed specifically in tumor-associated endothelial cells have been identified and characterized. These discoveries have enhanced the prospectus of transcriptionaly targeting tumor endothelial cells for cancer gene therapy. In this manuscript, we review the promoters, vectors, and therapeutic genes that have been used for transcriptional targeting of tumor endothelial cells, and discuss the prospects of such approaches for cancer gene therapy. PMID:19393703

  20. Molecular pathways: targeting ETS gene fusions in cancer.

    PubMed

    Feng, Felix Y; Brenner, J Chad; Hussain, Maha; Chinnaiyan, Arul M

    2014-09-01

    Rearrangements, or gene fusions, involving the ETS family of transcription factors are common driving events in both prostate cancer and Ewing sarcoma. These rearrangements result in pathogenic expression of the ETS genes and trigger activation of transcriptional programs enriched for invasion and other oncogenic features. Although ETS gene fusions represent intriguing therapeutic targets, transcription factors, such as those comprising the ETS family, have been notoriously difficult to target. Recently, preclinical studies have demonstrated an association between ETS gene fusions and components of the DNA damage response pathway, such as PARP1, the catalytic subunit of DNA protein kinase (DNAPK), and histone deactylase 1 (HDAC1), and have suggested that ETS fusions may confer sensitivity to inhibitors of these DNA repair proteins. In this review, we discuss the role of ETS fusions in cancer, the preclinical rationale for targeting ETS fusions with inhibitors of PARP1, DNAPK, and HDAC1, as well as ongoing clinical trials targeting ETS gene fusions.

  1. Small molecule activation of NOTCH signaling inhibits acute myeloid leukemia.

    PubMed

    Ye, Qi; Jiang, Jue; Zhan, Guanqun; Yan, Wanyao; Huang, Liang; Hu, Yufeng; Su, Hexiu; Tong, Qingyi; Yue, Ming; Li, Hua; Yao, Guangmin; Zhang, Yonghui; Liu, Hudan

    2016-01-01

    Aberrant activation of the NOTCH signaling pathway is crucial for the onset and progression of T cell leukemia. Yet recent studies also suggest a tumor suppressive role of NOTCH signaling in acute myeloid leukemia (AML) and reactivation of this pathway offers an attractive opportunity for anti-AML therapies. N-methylhemeanthidine chloride (NMHC) is a novel Amaryllidaceae alkaloid that we previously isolated from Zephyranthes candida, exhibiting inhibitory activities in a variety of cancer cells, particularly those from AML. Here, we report NMHC not only selectively inhibits AML cell proliferation in vitro but also hampers tumor development in a human AML xenograft model. Genome-wide gene expression profiling reveals that NMHC activates the NOTCH signaling. Combination of NMHC and recombinant human NOTCH ligand DLL4 achieves a remarkable synergistic effect on NOTCH activation. Moreover, pre-inhibition of NOTCH by overexpression of dominant negative MAML alleviates NMHC-mediated cytotoxicity in AML. Further mechanistic analysis using structure-based molecular modeling as well as biochemical assays demonstrates that NMHC docks in the hydrophobic cavity within the NOTCH1 negative regulatory region (NRR), thus promoting NOTCH1 proteolytic cleavage. Our findings thus establish NMHC as a potential NOTCH agonist that holds great promises for future development as a novel agent beneficial to patients with AML. PMID:27211848

  2. Small molecule activation of NOTCH signaling inhibits acute myeloid leukemia

    PubMed Central

    Ye, Qi; Jiang, Jue; Zhan, Guanqun; Yan, Wanyao; Huang, Liang; Hu, Yufeng; Su, Hexiu; Tong, Qingyi; Yue, Ming; Li, Hua; Yao, Guangmin; Zhang, Yonghui; Liu, Hudan

    2016-01-01

    Aberrant activation of the NOTCH signaling pathway is crucial for the onset and progression of T cell leukemia. Yet recent studies also suggest a tumor suppressive role of NOTCH signaling in acute myeloid leukemia (AML) and reactivation of this pathway offers an attractive opportunity for anti-AML therapies. N-methylhemeanthidine chloride (NMHC) is a novel Amaryllidaceae alkaloid that we previously isolated from Zephyranthes candida, exhibiting inhibitory activities in a variety of cancer cells, particularly those from AML. Here, we report NMHC not only selectively inhibits AML cell proliferation in vitro but also hampers tumor development in a human AML xenograft model. Genome-wide gene expression profiling reveals that NMHC activates the NOTCH signaling. Combination of NMHC and recombinant human NOTCH ligand DLL4 achieves a remarkable synergistic effect on NOTCH activation. Moreover, pre-inhibition of NOTCH by overexpression of dominant negative MAML alleviates NMHC-mediated cytotoxicity in AML. Further mechanistic analysis using structure-based molecular modeling as well as biochemical assays demonstrates that NMHC docks in the hydrophobic cavity within the NOTCH1 negative regulatory region (NRR), thus promoting NOTCH1 proteolytic cleavage. Our findings thus establish NMHC as a potential NOTCH agonist that holds great promises for future development as a novel agent beneficial to patients with AML. PMID:27211848

  3. Notch signaling from the endosome requires a conserved dileucine motif

    PubMed Central

    Zheng, Li; Saunders, Cosmo A.; Sorensen, Erika B.; Waxmonsky, Nicole C.; Conner, Sean D.

    2013-01-01

    Notch signaling is reliant on γ-secretase–mediated processing, although the subcellular location where γ-secretase cleaves Notch to initiate signaling remains unresolved. Accumulating evidence demonstrates that Notch signaling is modulated by endocytosis and endosomal transport. In this study, we investigated the relationship between Notch transport itinerary and signaling capacity. In doing so, we discovered a highly conserved dileucine sorting signal encoded within the cytoplasmic tail that directs Notch to the limiting membrane of the lysosome for signaling. Mutating the dileucine motif led to receptor accumulation in cation-dependent mannose-phosphate receptor–positive tubular early endosomes and a reduction in Notch signaling capacity. Moreover, truncated receptor forms that mimic activated Notch were readily cleaved by γ-secretase within the endosome; however, the cleavage product was proteasome-sensitive and failed to contribute to robust signaling. Collectively these results indicate that Notch signaling from the lysosome limiting membrane is conserved and that receptor targeting to this compartment is an active process. Moreover, the data support a model in which Notch signaling in mammalian systems is initiated from either the plasma membrane or lysosome, but not the early endosome. PMID:23171551

  4. An enhanced gene targeting toolkit for Drosophila: Golic+.

    PubMed

    Chen, Hui-Min; Huang, Yaling; Pfeiffer, Barret D; Yao, Xiaohao; Lee, Tzumin

    2015-03-01

    Ends-out gene targeting allows seamless replacement of endogenous genes with engineered DNA fragments by homologous recombination, thus creating designer "genes" in the endogenous locus. Conventional gene targeting in Drosophila involves targeting with the preintegrated donor DNA in the larval primordial germ cells. Here we report G: ene targeting during O: ogenesis with L: ethality I: nhibitor and C: RISPR/Cas (Golic+), which improves on all major steps in such transgene-based gene targeting systems. First, donor DNA is integrated into precharacterized attP sites for efficient flip-out. Second, FLP, I-SceI, and Cas9 are specifically expressed in cystoblasts, which arise continuously from female germline stem cells, thereby providing a continual source of independent targeting events in each offspring. Third, a repressor-based lethality selection is implemented to facilitate screening for correct targeting events. Altogether, Golic+ realizes high-efficiency ends-out gene targeting in ovarian cystoblasts, which can be readily scaled up to achieve high-throughput genome editing. PMID:25555988

  5. An Enhanced Gene Targeting Toolkit for Drosophila: Golic+

    PubMed Central

    Chen, Hui-Min; Huang, Yaling; Pfeiffer, Barret D.; Yao, Xiaohao; Lee, Tzumin

    2015-01-01

    Ends-out gene targeting allows seamless replacement of endogenous genes with engineered DNA fragments by homologous recombination, thus creating designer “genes” in the endogenous locus. Conventional gene targeting in Drosophila involves targeting with the preintegrated donor DNA in the larval primordial germ cells. Here we report gene targeting during oogenesis with lethality inhibitor and CRISPR/Cas (Golic+), which improves on all major steps in such transgene-based gene targeting systems. First, donor DNA is integrated into precharacterized attP sites for efficient flip-out. Second, FLP, I-SceI, and Cas9 are specifically expressed in cystoblasts, which arise continuously from female germline stem cells, thereby providing a continual source of independent targeting events in each offspring. Third, a repressor-based lethality selection is implemented to facilitate screening for correct targeting events. Altogether, Golic+ realizes high-efficiency ends-out gene targeting in ovarian cystoblasts, which can be readily scaled up to achieve high-throughput genome editing. PMID:25555988

  6. Notch-independent RBPJ controls angiogenesis in the adult heart

    PubMed Central

    Díaz-Trelles, Ramón; Scimia, Maria Cecilia; Bushway, Paul; Tran, Danh; Monosov, Anna; Monosov, Edward; Peterson, Kirk; Rentschler, Stacey; Cabrales, Pedro; Ruiz-Lozano, Pilar; Mercola, Mark

    2016-01-01

    Increasing angiogenesis has long been considered a therapeutic target for improving heart function after injury such as acute myocardial infarction. However, gene, protein and cell therapies to increase microvascularization have not been successful, most likely because the studies failed to achieve regulated and concerted expression of pro-angiogenic and angiostatic factors needed to produce functional microvasculature. Here, we report that the transcription factor RBPJ is a homoeostatic repressor of multiple pro-angiogenic and angiostatic factor genes in cardiomyocytes. RBPJ controls angiogenic factor gene expression independently of Notch by antagonizing the activity of hypoxia-inducible factors (HIFs). In contrast to previous strategies, the cardiomyocyte-specific deletion of Rbpj increased microvascularization of the heart without adversely affecting cardiac structure or function even into old age. Furthermore, the loss of RBPJ in cardiomyocytes increased hypoxia tolerance, improved heart function and decreased pathological remodelling after myocardial infarction, suggesting that inhibiting RBPJ might be therapeutic for ischaemic injury. PMID:27357444

  7. Notch1-mediated signaling regulates proliferation of porcine satellite cells (PSCs).

    PubMed

    Qin, Lili; Xu, Jian; Wu, Zhenfang; Zhang, Zhe; Li, Jiaqi; Wang, Chong; Long, Qiaoming

    2013-02-01

    Notch signaling is an evolutionarily conserved cell-cell communication mechanism involved in the regulation of cell proliferation, differentiation and fate decisions of mammalian cells. In the present study, we investigated the possible requirement for Notch signaling in the proliferation and differentiation of porcine satellite cells. We show that Notch1, 2 and 3 are expressed in cultured porcine satellite cells. Knock-down of NOTCH1, but not NOTCH2 and NOTCH3, decreases the proliferation of porcine satellite cells. In contrast, enhancement of NOTCH1 expression via treatment of porcine satellite cells with recombinant NF-κB increases the proliferation of porcine satellite cells. The alteration of porcine satellite cell proliferation is associated with significant changes in the expression of cell cycle related genes (cyclin B1, D1, D2, E1 and p21), myogenic regulatory factors (MyoD and myogenin) and the Notch effector Hes5. In addition, alteration of Notch1 expression in porcine satellite cells causes changes in the expression of GSK3β-3. Taken together, these findings suggest that of the four notch-related genes, Notch1is likely to be required for regulating the proliferation and therefore the maintenance of porcine satellite cells in vivo, and do so through activation of the Notch effector gene Hes5. PMID:23160004

  8. Notch1-mediated signaling regulates proliferation of porcine satellite cells (PSCs).

    PubMed

    Qin, Lili; Xu, Jian; Wu, Zhenfang; Zhang, Zhe; Li, Jiaqi; Wang, Chong; Long, Qiaoming

    2013-02-01

    Notch signaling is an evolutionarily conserved cell-cell communication mechanism involved in the regulation of cell proliferation, differentiation and fate decisions of mammalian cells. In the present study, we investigated the possible requirement for Notch signaling in the proliferation and differentiation of porcine satellite cells. We show that Notch1, 2 and 3 are expressed in cultured porcine satellite cells. Knock-down of NOTCH1, but not NOTCH2 and NOTCH3, decreases the proliferation of porcine satellite cells. In contrast, enhancement of NOTCH1 expression via treatment of porcine satellite cells with recombinant NF-κB increases the proliferation of porcine satellite cells. The alteration of porcine satellite cell proliferation is associated with significant changes in the expression of cell cycle related genes (cyclin B1, D1, D2, E1 and p21), myogenic regulatory factors (MyoD and myogenin) and the Notch effector Hes5. In addition, alteration of Notch1 expression in porcine satellite cells causes changes in the expression of GSK3β-3. Taken together, these findings suggest that of the four notch-related genes, Notch1is likely to be required for regulating the proliferation and therefore the maintenance of porcine satellite cells in vivo, and do so through activation of the Notch effector gene Hes5.

  9. Gene-targeting pharmaceuticals for single-gene disorders.

    PubMed

    Beaudet, Arthur L; Meng, Linyan

    2016-04-15

    The concept of orphan drugs for treatment of orphan genetic diseases is perceived enthusiastically at present, and this is leading to research investment on the part of governments, disease-specific foundations and industry. This review attempts to survey the potential to use traditional pharmaceuticals as opposed to biopharmaceuticals to treat single-gene disorders. The available strategies include the use of antisense oligonucleotides (ASOs) to alter splicing or knock-down expression of a transcript, siRNAs to knock-down gene expression and drugs for nonsense mutation read-through. There is an approved drug for biallelic knock-down of the APOB gene as treatment for familial hypercholesterolemia. Both ASOs and siRNAs are being explored to knock-down the transthyretin gene to prevent the related form of amyloidosis. The use of ASOs to alter gene-splicing to treat spinal muscular atrophy is in phase 3 clinical trials. Work is progressing on the use of ASOs to activate the normally silent paternal copy of the imprinted UBE3A gene in neurons as a treatment for Angelman syndrome. A gene-activation or gene-specific ramp-up strategy would be generally helpful if such could be developed. There is exciting theoretical potential for converting biopharmaceutical strategies such gene correction and CRISPR-Cas9 editing to a synthetic pharmaceutical approach. PMID:26628634

  10. AAV-mediated gene targeting methods for human cells

    PubMed Central

    Khan, Iram F; Hirata, Roli K; Russell, David W

    2013-01-01

    Gene targeting with adeno-associated virus (AAV) vectors has been demonstrated in multiple human cell types, with targeting frequencies ranging from 10−5 to 10−2 per infected cell. these targeting frequencies are 1–4 logs higher than those obtained by conventional transfection or electroporation approaches. a wide variety of different types of mutations can be introduced into chromosomal loci with high fidelity and without genotoxicity. Here we provide a detailed protocol for gene targeting in human cells with AAV vectors. We describe methods for vector design, stock preparation and titration. optimized transduction protocols are provided for human pluripotent stem cells, mesenchymal stem cells, fibroblasts and transformed cell lines, as well as a method for identifying targeted clones by southern blots. this protocol (from vector design through a single round of targeting and screening) can be completed in ~10 weeks; each subsequent round of targeting and screening should take an additional 7 weeks. PMID:21455185

  11. Inhibition of Daughterless by Extramacrochaetae mediates Notch-induced cell proliferation

    PubMed Central

    Spratford, Carrie M.; Kumar, Justin P.

    2015-01-01

    ABSTRACT During development, the rate of cell proliferation must be constantly monitored so that an individual tissue achieves its correct size. Mutations in genes that normally promote tissue growth often result in undersized, disorganized and non-functional organs. However, mutations in genes that encode growth inhibitors can trigger the onset of tumorigenesis and cancer. The developing eye of the fruit fly, Drosophila melanogaster, has become a premier model system for studies that are focused on identifying the molecular mechanisms that underpin growth control. Here, we examine the mechanism by which the Notch pathway, a major contributor to growth, promotes cell proliferation in the developing eye. Current models propose that the Notch pathway directly influences cell proliferation by regulating growth-promoting genes such as four-jointed, cyclin D1 and E2f1. Here, we show that, in addition to these mechanisms, some Notch signaling is devoted to blocking the growth-suppressing activity of the bHLH DNA-binding protein Daughterless (Da). We demonstrate that Notch signaling activates the expression of extramacrochaetae (emc), which encodes a helix-loop-helix (HLH) transcription factor. Emc, in turn, then forms a biochemical complex with Da. As Emc lacks a basic DNA-binding domain, the Emc-Da heterodimer cannot bind to and regulate genomic targets. One effect of Da sequestration is to relieve the repression on growth. Here, we present data supporting our model that Notch-induced cell proliferation in the developing eye is mediated in part by the activity of Emc. PMID:25977368

  12. Notch signaling activation in pediatric low-grade astrocytoma.

    PubMed

    Brandt, William D; Schreck, Karisa C; Bar, Eli E; Taylor, Isabella; Marchionni, Luigi; Raabe, Eric; Eberhart, Charles G; Rodriguez, Fausto J

    2015-02-01

    Pilocytic astrocytoma (PA) is the most common primary brain tumor in children; various signaling pathways have been implicated in its biology. The Notch signaling pathway has been found to play a role in the development, stem cell biology, and pathogenesis of several cancers, but its role in PA has not been investigated. We studied alterations in Notch signaling components in tumor tissue from 18 patients with PA and 4 with other low-grade astrocytomas to identify much needed therapeutic targets. We found that Notch pathway members were overexpressed at the mRNA (NOTCH1, NOTCH2, HEY1, HEY2) and protein (HES1) levels in PAs at various anatomic sites compared with non-neoplastic brain samples. These changes were not associated with specific BRAF alterations. Inhibiting the Notch pathway in the pediatric low-grade astrocytoma cell lines Res186 and Res259 using either RNA interference or a γ-secretase inhibitor resulted in variable, but significant, reduction in cell growth and migration. This study suggests a potential role for Notch signaling in pediatric low-grade astrocytoma tumorigenesis and that Notch signaling may be a viable pathway therapeutic target. PMID:25575134

  13. Pre-clinical studies of Notch signaling inhibitor RO4929097 in inflammatory breast cancer cells.

    PubMed

    Debeb, Bisrat G; Cohen, Evan N; Boley, Kimberly; Freiter, Erik M; Li, Li; Robertson, Fredika M; Reuben, James M; Cristofanilli, Massimo; Buchholz, Thomas A; Woodward, Wendy A

    2012-07-01

    Basal breast cancer, common among patients presenting with inflammatory breast cancer (IBC), has been shown to be resistant to radiation and enriched in cancer stem cells. The Notch pathway plays an important role in self-renewal of breast cancer stem cells and contributes to inflammatory signaling which promotes the breast cancer stem cell phenotype. Herein, we inhibited Notch signaling using a gamma secretase inhibitor, RO4929097, in an in vitro model that enriches for cancer initiating cells (3D clonogenic assay) and conventional 2D clonogenic assay to compare the effect on radiosensitization of the SUM149 and SUM190 IBC cell lines. RO4929097 downregulated the Notch target genes Hes1, Hey1, and HeyL, and showed a significant reduction in anchorage independent growth in SUM190 and SUM149. However, the putative self-renewal assay mammosphere formation efficiency was increased with the drug. To assess radiosensitization of putative cancer stem cells, cells were exposed to increasing doses of radiation with or without 1 μM RO4929097 in their standard (2D) and self-renewal enriching (3D) culture conditions. In the conventional 2D clonogenic assay, RO4929097 significantly sensitized SUM190 cells to ionizing radiation and has a modest radiosensitization effect in SUM149 cells. In the 3D clonogenic assays, however, a radioprotective effect was seen in both SUM149 and SUM190 cells at higher doses. Both cell lines express IL-6 and IL-8 cytokines known to mediate the efficacy of Notch inhibition and to promote self-renewal of stem cells. We further showed that RO429097 inhibits normal T-cell synthesis of some inflammatory cytokines, including TNF-α, a potential mediator of IL-6 and IL-8 production in the microenvironment. These data suggest that additional targeting agents may be required to selectively target IBC stem cells through Notch inhibition, and that evaluation of microenvironmental influences may shed further light on the potential effects of this inhibitor.

  14. NOTCH reprograms mitochondrial metabolism for proinflammatory macrophage activation

    PubMed Central

    Xu, Jun; Chi, Feng; Guo, Tongsheng; Punj, Vasu; Lee, W.N. Paul; French, Samuel W.; Tsukamoto, Hidekazu

    2015-01-01

    Metabolic reprogramming is implicated in macrophage activation, but the underlying mechanisms are poorly understood. Here, we demonstrate that the NOTCH1 pathway dictates activation of M1 phenotypes in isolated mouse hepatic macrophages (HMacs) and in a murine macrophage cell line by coupling transcriptional upregulation of M1 genes with metabolic upregulation of mitochondrial oxidative phosphorylation and ROS (mtROS) to augment induction of M1 genes. Enhanced mitochondrial glucose oxidation was achieved by increased recruitment of the NOTCH1 intracellular domain (NICD1) to nuclear and mitochondrial genes that encode respiratory chain components and by NOTCH-dependent induction of pyruvate dehydrogenase phosphatase 1 (Pdp1) expression, pyruvate dehydrogenase activity, and glucose flux to the TCA cycle. As such, inhibition of the NOTCH pathway or Pdp1 knockdown abrogated glucose oxidation, mtROS, and M1 gene expression. Conditional NOTCH1 deficiency in the myeloid lineage attenuated HMac M1 activation and inflammation in a murine model of alcoholic steatohepatitis and markedly reduced lethality following endotoxin-mediated fulminant hepatitis in mice. In vivo monocyte tracking further demonstrated the requirement of NOTCH1 for the migration of blood monocytes into the liver and subsequent M1 differentiation. Together, these results reveal that NOTCH1 promotes reprogramming of mitochondrial metabolism for M1 macrophage activation. PMID:25798621

  15. Self-targeting by CRISPR: gene regulation or autoimmunity?

    PubMed Central

    Stern, Adi; Keren, Leeat; Wurtzel, Omri; Amitai, Gil; Sorek, Rotem

    2010-01-01

    CRISPR/Cas is a recently discovered prokaryotic immune system, which is based on small RNAs (“spacers”) that restrict phage and plasmid infection. It has been hypothesized that CRISPRs can also regulate self gene expression by utilizing spacers that target self genes. By analyzing CRISPRs from 330 organisms we found that one in every 250 spacers is self targeting, and that such self-targeting occurs in 18% of all CRISPR-bearing organisms. However, complete lack of conservation across species, combined with abundance of degraded repeats near self-targeting spacers, suggests that self-targeting is a consequence of autoimmunity rather than gene regulation. We propose that accidental incorporation of self nucleic-acids by CRISPR can incur an autoimmune fitness cost, which may explain the abundance of degraded CRISPR systems across prokaryotes. PMID:20598393

  16. Notch is required for long-term memory in Drosophila

    PubMed Central

    Presente, Asaf; Boyles, Randy S.; Serway, Christine N.; de Belle, J. Steven; Andres, Andrew J.

    2004-01-01

    A role for Notch in the elaboration of existing neural processes is emerging that is distinct from the increasingly well understood function of this gene in binary cell-fate decisions. Several research groups, by using a variety of organisms, have shown that Notch is important in the development of neural ultrastructure. Simultaneously, Presenilin (Psn) was identified both as a key mediator of Notch signaling and as a site of genetic lesions that cause early-onset Alzheimer's disease. Here we demonstrate that Notch loss of function produces memory deficits in Drosophila melanogaster. The effects are specific to long-term memory, which is thought to depend on ultrastructural remodeling. We propose that Notch plays an important role in the neural plasticity underlying consolidated memory. PMID:14752200

  17. Notch is required for long-term memory in Drosophila.

    PubMed

    Presente, Asaf; Boyles, Randy S; Serway, Christine N; de Belle, J Steven; Andres, Andrew J

    2004-02-10

    A role for Notch in the elaboration of existing neural processes is emerging that is distinct from the increasingly well understood function of this gene in binary cell-fate decisions. Several research groups, by using a variety of organisms, have shown that Notch is important in the development of neural ultrastructure. Simultaneously, Presenilin (Psn) was identified both as a key mediator of Notch signaling and as a site of genetic lesions that cause early-onset Alzheimer's disease. Here we demonstrate that Notch loss of function produces memory deficits in Drosophila melanogaster. The effects are specific to long-term memory, which is thought to depend on ultrastructural remodeling. We propose that Notch plays an important role in the neural plasticity underlying consolidated memory.

  18. Adropin is a brain membrane-bound protein regulating physical activity via the NB-3/Notch signaling pathway in mice.

    PubMed

    Wong, Chi-Ming; Wang, Yudong; Lee, Jimmy Tsz Hang; Huang, Zhe; Wu, Donghai; Xu, Aimin; Lam, Karen Siu Ling

    2014-09-12

    Adropin is a highly conserved polypeptide that has been suggested to act as an endocrine factor that plays important roles in metabolic regulation, insulin sensitivity, and endothelial functions. However, in this study, we provide evidence demonstrating that adropin is a plasma membrane protein expressed abundantly in the brain. Using a yeast two-hybrid screening approach, we identified NB-3/Contactin 6, a brain-specific, non-canonical, membrane-tethered Notch1 ligand, as an interaction partner of adropin. Furthermore, this interaction promotes NB3-induced activation of Notch signaling and the expression of Notch target genes. We also generated and characterized adropin knockout mice to explore the role of adropin in vivo. Adropin knockout mice exhibited decreased locomotor activity and impaired motor coordination coupled with defective synapse formation, a phenotype similar to NB-3 knockout mice. Taken together, our data suggest that adropin is a membrane-bound protein that interacts with the brain-specific Notch1 ligand NB3. It regulates physical activity and motor coordination via the NB-3/Notch signaling pathway and plays an important role in cerebellum development in mice.

  19. BCAS2 Regulates Delta-Notch Signaling Activity through Delta Pre-mRNA Splicing in Drosophila Wing Development

    PubMed Central

    Huang, Chu-Wei; Chen, Po-Han; Chan, Shih-Peng; Tsao, Yeou-Ping; Lee, Hsiu-Hsiang; Wu, June-Tai; Chen, Show-Li

    2015-01-01

    Previously, we showed that BCAS2 is essential for Drosophila viability and functions in pre-mRNA splicing. In this study, we provide strong evidence that BCAS2 regulates the activity of Delta-Notch signaling via Delta pre-mRNA splicing. Depletion of dBCAS2 reduces Delta mRNA expression and leads to accumulation of Delta pre-mRNA, resulting in diminished transcriptions of Delta-Notch signaling target genes, such as cut and E(spl)m8. Furthermore, ectopic expression of human BCAS2 (hBCAS2) and Drosophila BCAS2 (dBCAS2) in a dBCAS2-deprived fly can rescue dBCAS2 depletion-induced wing damage to the normal phenotypes. These rescued phenotypes are correlated with the restoration of Delta pre-mRNA splicing, which affects Delta-Notch signaling activity. Additionally, overexpression of Delta can rescue the wing deformation by deprivation of dBCAS2; and the depletion of dBCAS2 can restore the aberrant eye associated with Delta-overexpressing retinas; providing supporting evidence for the regulation of Delta-Notch signaling by dBCAS2. Taken together, dBCAS2 participates in Delta pre-mRNA splicing that affects the regulation of Delta-Notch signaling in Drosophila wing development. PMID:26091239

  20. The hair follicle as a target for gene therapy.

    PubMed

    Gupta, S; Domashenko, A; Cotsarelis, G

    2001-01-01

    The hair follicle possesses progenitor cells for continued hair follicle cycling and for epidermal keratinocytes, melanocytes and Langerhans cells. These different cell types can be targeted by topical gene delivery to mouse skin. Using a combination of liposomes and DNA, we demonstrated the feasibility of targeting hair follicle cells in human scalp xenografts as well. We defined liposome composition and stage of the hair cycle as important parameters influencing transfection of human hair follicles. Transfection occurred only during anagen onset. Considerations and obstacles for using gene therapy to treat alopecias and skin disease are discussed. A theoretical framework for future gene therapy treatments for cutaneous and systemic disorders is presented.

  1. Transductional targeting of adenovirus vectors for gene therapy

    PubMed Central

    Glasgow, JN; Everts, M; Curiel, DT

    2007-01-01

    Cancer gene therapy approaches will derive considerable benefit from adenovirus (Ad) vectors capable of self-directed localization to neoplastic disease or immunomodulatory targets in vivo. The ablation of native Ad tropism coupled with active targeting modalities has demonstrated that innate gene delivery efficiency may be retained while circumventing Ad dependence on its primary cellular receptor, the coxsackie and Ad receptor. Herein, we describe advances in Ad targeting that are predicated on a fundamental understanding of vector/cell interplay. Further, we propose strategies by which existing paradigms, such as nanotechnology, may be combined with Ad vectors to form advanced delivery vehicles with multiple functions. PMID:16439993

  2. The Notch ligand Delta-like 1 integrates inputs from TGFbeta/Activin and Wnt pathways

    SciTech Connect

    Bordonaro, Michael Tewari, Shruti Atamna, Wafa Lazarova, Darina L.

    2011-06-10

    Unlike the well-characterized nuclear function of the Notch intracellular domain, it has been difficult to identify a nuclear role for the ligands of Notch. Here we provide evidence for the nuclear function of the Notch ligand Delta-like 1 in colon cancer (CC) cells exposed to butyrate. We demonstrate that the intracellular domain of Delta-like 1 (Dll1icd) augments the activity of Wnt signaling-dependent reporters and that of the promoter of the connective tissue growth factor (CTGF) gene. Data suggest that Dll1icd upregulates CTGF promoter activity through both direct and indirect mechanisms. The direct mechanism is supported by co-immunoprecipitation of endogenous Smad2/3 proteins and Dll1 and by chromatin immunoprecipitation analyses that revealed the occupancy of Dll1icd on CTGF promoter sequences containing a Smad binding element. The indirect upregulation of CTGF expression by Dll1 is likely due to the ability of Dll1icd to increase Wnt signaling, a pathway that targets CTGF. CTGF expression is induced in butyrate-treated CC cells and results from clonal growth assays support a role for CTGF in the cell growth-suppressive role of butyrate. In conclusion, integration of the Notch, Wnt, and TGFbeta/Activin signaling pathways is in part mediated by the interactions of Dll1 with Smad2/3 and Tcf4.

  3. Structure and Function of the CSL-KyoT2 Corepressor Complex – a Negative Regulator of Notch Signaling

    PubMed Central

    Collins, Kelly J.; Yuan, Zhenyu; Kovall, Rhett A.

    2013-01-01

    Summary Notch refers to a highly conserved cell-to-cell signaling pathway with essential roles in embryonic development and tissue maintenance. Dysfunctional signaling causes human disease, highlighting the importance of pathway regulation. Notch signaling ultimately results in the activation of target genes, which is regulated by the nuclear effector CSL. CSL dually functions as an activator and repressor of transcription through differential interactions with coactivator or corepressor proteins, respectively. While the structures of CSL-coactivator complexes have been determined, the structures of CSL-corepressor complexes are unknown. Here, using a combination of structural, biophysical, and cellular approaches, we characterize the structure and function of CSL in complex with the corepressor KyoT2. Collectively, our studies provide molecular insights into how KyoT2 binds CSL with high affinity and competes with coactivators, such as Notch, for binding CSL. These studies are important for understanding how CSL functions as both an activator and repressor of transcription of Notch target genes. PMID:24290140

  4. Advanced glycation end product-induced astrocytic differentiation of cultured neurospheres through inhibition of Notch-Hes1 pathway-mediated neurogenesis.

    PubMed

    Guo, Yijing; Wang, Pin; Sun, Haixia; Cai, Rongrong; Xia, Wenqing; Wang, Shaohua

    2014-01-01

    This study aims to investigate the roles of the Notch-Hes1 pathway in the advanced glycation end product (AGE)-mediated differentiation of neural stem cells (NSCs). We prepared pLentiLox3.7 lentiviral vectors that express short hairpin RNA (shRNA) against Notch1 and transfected it into NSCs. Cell differentiation was analyzed under confocal laser-scanning microscopy. The percentage of neurons and astrocytes was quantified by normalizing the total number of TUJ1+ (Neuron-specific class III β-tubulin) and GFAP+ (Glial fibrillary acidic protein) cells to the total number of Hoechst 33342-labeled cell nuclei. The protein and gene expression of Notch-Hes1 pathway components was examined via western blot analysis and real-time PCR. After 1 week of incubation, we found that AGE-bovine serum albumin (BSA) (400 μg/mL) induced the astrocytic differentiation of cultured neurospheres and inhibited neuronal formation. The expression of Notch-Hes1 pathway components was upregulated in the cells in the AGE-BSA culture medium. Immunoblot analysis indicated that shRNA silencing of Notch1 expression in NSCs significantly increases neurogenesis and suppresses astrocytic differentiation in NSCs incubated with AGE-BSA. AGEs promote the astrocytic differentiation of cultured neurospheres by inhibiting neurogenesis through the Notch-Hes1 pathway, providing a potential therapeutic target for hyperglycemia-related cognitive deficits.

  5. Identification of p53-target genes in Danio rerio.

    PubMed

    Mandriani, Barbara; Castellana, Stefano; Rinaldi, Carmela; Manzoni, Marta; Venuto, Santina; Rodriguez-Aznar, Eva; Galceran, Juan; Nieto, M Angela; Borsani, Giuseppe; Monti, Eugenio; Mazza, Tommaso; Merla, Giuseppe; Micale, Lucia

    2016-01-01

    To orchestrate the genomic response to cellular stress signals, p53 recognizes and binds to DNA containing specific and well-characterized p53-responsive elements (REs). Differences in RE sequences can strongly affect the p53 transactivation capacity and occur even between closely related species. Therefore, the identification and characterization of a species-specific p53 Binding sistes (BS) consensus sequence and of the associated target genes may help to provide new insights into the evolution of the p53 regulatory networks across different species. Although p53 functions were studied in a wide range of species, little is known about the p53-mediated transcriptional signature in Danio rerio. Here, we designed and biochemically validated a computational approach to identify novel p53 target genes in Danio rerio genome. Screening all the Danio rerio genome by pattern-matching-based analysis, we found p53 RE-like patterns proximal to 979 annotated Danio rerio genes. Prioritization analysis identified a subset of 134 candidate pattern-related genes, 31 of which have been investigated in further biochemical assays. Our study identified runx1, axin1, traf4a, hspa8, col4a5, necab2, and dnajc9 genes as novel direct p53 targets and 12 additional p53-controlled genes in Danio rerio genome. The proposed combinatorial approach resulted to be highly sensitive and robust for identifying new p53 target genes also in additional animal species. PMID:27581768

  6. Identification of p53-target genes in Danio rerio

    PubMed Central

    Mandriani, Barbara; Castellana, Stefano; Rinaldi, Carmela; Manzoni, Marta; Venuto, Santina; Rodriguez-Aznar, Eva; Galceran, Juan; Nieto, M. Angela; Borsani, Giuseppe; Monti, Eugenio; Mazza, Tommaso; Merla, Giuseppe; Micale, Lucia

    2016-01-01

    To orchestrate the genomic response to cellular stress signals, p53 recognizes and binds to DNA containing specific and well-characterized p53-responsive elements (REs). Differences in RE sequences can strongly affect the p53 transactivation capacity and occur even between closely related species. Therefore, the identification and characterization of a species-specific p53 Binding sistes (BS) consensus sequence and of the associated target genes may help to provide new insights into the evolution of the p53 regulatory networks across different species. Although p53 functions were studied in a wide range of species, little is known about the p53-mediated transcriptional signature in Danio rerio. Here, we designed and biochemically validated a computational approach to identify novel p53 target genes in Danio rerio genome. Screening all the Danio rerio genome by pattern-matching-based analysis, we found p53 RE-like patterns proximal to 979 annotated Danio rerio genes. Prioritization analysis identified a subset of 134 candidate pattern-related genes, 31 of which have been investigated in further biochemical assays. Our study identified runx1, axin1, traf4a, hspa8, col4a5, necab2, and dnajc9 genes as novel direct p53 targets and 12 additional p53-controlled genes in Danio rerio genome. The proposed combinatorial approach resulted to be highly sensitive and robust for identifying new p53 target genes also in additional animal species. PMID:27581768

  7. Identification of p53-target genes in Danio rerio.

    PubMed

    Mandriani, Barbara; Castellana, Stefano; Rinaldi, Carmela; Manzoni, Marta; Venuto, Santina; Rodriguez-Aznar, Eva; Galceran, Juan; Nieto, M Angela; Borsani, Giuseppe; Monti, Eugenio; Mazza, Tommaso; Merla, Giuseppe; Micale, Lucia

    2016-01-01

    To orchestrate the genomic response to cellular stress signals, p53 recognizes and binds to DNA containing specific and well-characterized p53-responsive elements (REs). Differences in RE sequences can strongly affect the p53 transactivation capacity and occur even between closely related species. Therefore, the identification and characterization of a species-specific p53 Binding sistes (BS) consensus sequence and of the associated target genes may help to provide new insights into the evolution of the p53 regulatory networks across different species. Although p53 functions were studied in a wide range of species, little is known about the p53-mediated transcriptional signature in Danio rerio. Here, we designed and biochemically validated a computational approach to identify novel p53 target genes in Danio rerio genome. Screening all the Danio rerio genome by pattern-matching-based analysis, we found p53 RE-like patterns proximal to 979 annotated Danio rerio genes. Prioritization analysis identified a subset of 134 candidate pattern-related genes, 31 of which have been investigated in further biochemical assays. Our study identified runx1, axin1, traf4a, hspa8, col4a5, necab2, and dnajc9 genes as novel direct p53 targets and 12 additional p53-controlled genes in Danio rerio genome. The proposed combinatorial approach resulted to be highly sensitive and robust for identifying new p53 target genes also in additional animal species.

  8. Computational discovery of Epstein-Barr virus targeted human genes and signalling pathways

    PubMed Central

    Mei, Suyu; Zhang, Kun

    2016-01-01

    Epstein-Barr virus (EBV) plays important roles in the origin and the progression of human carcinomas, e.g. diffuse large B cell tumors, T cell lymphomas, etc. Discovering EBV targeted human genes and signaling pathways is vital to understand EBV tumorigenesis. In this study we propose a noise-tolerant homolog knowledge transfer method to reconstruct functional protein-protein interactions (PPI) networks between Epstein-Barr virus and Homo sapiens. The training set is augmented via homolog instances and the homolog noise is counteracted by support vector machine (SVM). Additionally we propose two methods to define subcellular co-localization (i.e. stringent and relaxed), based on which to further derive physical PPI networks. Computational results show that the proposed method achieves sound performance of cross validation and independent test. In the space of 648,672 EBV-human protein pairs, we obtain 51,485 functional interactions (7.94%), 869 stringent physical PPIs and 46,050 relaxed physical PPIs. Fifty-eight evidences are found from the latest database and recent literature to validate the model. This study reveals that Epstein-Barr virus interferes with normal human cell life, such as cholesterol homeostasis, blood coagulation, EGFR binding, p53 binding, Notch signaling, Hedgehog signaling, etc. The proteome-wide predictions are provided in the supplementary file for further biomedical research. PMID:27470517

  9. Computational discovery of Epstein-Barr virus targeted human genes and signalling pathways.

    PubMed

    Mei, Suyu; Zhang, Kun

    2016-01-01

    Epstein-Barr virus (EBV) plays important roles in the origin and the progression of human carcinomas, e.g. diffuse large B cell tumors, T cell lymphomas, etc. Discovering EBV targeted human genes and signaling pathways is vital to understand EBV tumorigenesis. In this study we propose a noise-tolerant homolog knowledge transfer method to reconstruct functional protein-protein interactions (PPI) networks between Epstein-Barr virus and Homo sapiens. The training set is augmented via homolog instances and the homolog noise is counteracted by support vector machine (SVM). Additionally we propose two methods to define subcellular co-localization (i.e. stringent and relaxed), based on which to further derive physical PPI networks. Computational results show that the proposed method achieves sound performance of cross validation and independent test. In the space of 648,672 EBV-human protein pairs, we obtain 51,485 functional interactions (7.94%), 869 stringent physical PPIs and 46,050 relaxed physical PPIs. Fifty-eight evidences are found from the latest database and recent literature to validate the model. This study reveals that Epstein-Barr virus interferes with normal human cell life, such as cholesterol homeostasis, blood coagulation, EGFR binding, p53 binding, Notch signaling, Hedgehog signaling, etc. The proteome-wide predictions are provided in the supplementary file for further biomedical research. PMID:27470517

  10. Nanoparticle-based targeted gene therapy for lung cancer

    PubMed Central

    Lee, Hung-Yen; Mohammed, Kamal A; Nasreen, Najmunnisa

    2016-01-01

    Despite striking insights on lung cancer progression, and cutting-edge therapeutic approaches the survival of patients with lung cancer, remains poor. In recent years, targeted gene therapy with nanoparticles is one of the most rapidly evolving and extensive areas of research for lung cancer. The major goal of targeted gene therapy is to bring forward a safe and efficient treatment to cancer patients via specifically targeting and deterring cancer cells in the body. To achieve high therapeutic efficacy of gene delivery, various carriers have been engineered and developed to provide protection to the genetic materials and efficient delivery to targeted cancer cells. Nanoparticles play an important role in the area of drug delivery and have been widely applied in cancer treatments for the purposes of controlled release and cancer cell targeting. Nanoparticles composed of artificial polymers, proteins, polysaccharides and lipids have been developed for the delivery of therapeutic deoxyribonucleic acid (DNA) or ribonucleic acid (RNA) sequences to target cancer. In addition, the effectiveness of cancer targeting has been enhanced by surface modification or conjugation with biomolecules on the surface of nanoparticles. In this review article we provide an overview on the latest developments in nanoparticle-based targeted gene therapy for lung cancers. Firstly, we outline the conventional therapies and discuss strategies for targeted gene therapy using nanoparticles. Secondly, we provide the most representative and recent researches in lung cancers including malignant pleural mesothelioma, mainly focusing on the application of Polymeric, Lipid-based, and Metal-based nanoparticles. Finally, we discuss current achievements and future challenges. PMID:27294004

  11. Single molecule targeted sequencing for cancer gene mutation detection.

    PubMed

    Gao, Yan; Deng, Liwei; Yan, Qin; Gao, Yongqian; Wu, Zengding; Cai, Jinsen; Ji, Daorui; Li, Gailing; Wu, Ping; Jin, Huan; Zhao, Luyang; Liu, Song; Ge, Liangjin; Deem, Michael W; He, Jiankui

    2016-01-01

    With the rapid decline in cost of sequencing, it is now affordable to examine multiple genes in a single disease-targeted clinical test using next generation sequencing. Current targeted sequencing methods require a separate step of targeted capture enrichment during sample preparation before sequencing. Although there are fast sample preparation methods available in market, the library preparation process is still relatively complicated for physicians to use routinely. Here, we introduced an amplification-free Single Molecule Targeted Sequencing (SMTS) technology, which combined targeted capture and sequencing in one step. We demonstrated that this technology can detect low-frequency mutations using artificially synthesized DNA sample. SMTS has several potential advantages, including simple sample preparation thus no biases and errors are introduced by PCR reaction. SMTS has the potential to be an easy and quick sequencing technology for clinical diagnosis such as cancer gene mutation detection, infectious disease detection, inherited condition screening and noninvasive prenatal diagnosis. PMID:27193446

  12. Single molecule targeted sequencing for cancer gene mutation detection

    PubMed Central

    Gao, Yan; Deng, Liwei; Yan, Qin; Gao, Yongqian; Wu, Zengding; Cai, Jinsen; Ji, Daorui; Li, Gailing; Wu, Ping; Jin, Huan; Zhao, Luyang; Liu, Song; Ge, Liangjin; Deem, Michael W.; He, Jiankui

    2016-01-01

    With the rapid decline in cost of sequencing, it is now affordable to examine multiple genes in a single disease-targeted clinical test using next generation sequencing. Current targeted sequencing methods require a separate step of targeted capture enrichment during sample preparation before sequencing. Although there are fast sample preparation methods available in market, the library preparation process is still relatively complicated for physicians to use routinely. Here, we introduced an amplification-free Single Molecule Targeted Sequencing (SMTS) technology, which combined targeted capture and sequencing in one step. We demonstrated that this technology can detect low-frequency mutations using artificially synthesized DNA sample. SMTS has several potential advantages, including simple sample preparation thus no biases and errors are introduced by PCR reaction. SMTS has the potential to be an easy and quick sequencing technology for clinical diagnosis such as cancer gene mutation detection, infectious disease detection, inherited condition screening and noninvasive prenatal diagnosis. PMID:27193446

  13. Notch strength of composites

    NASA Technical Reports Server (NTRS)

    Whitney, J. M.

    1983-01-01

    The notch strength of composites is discussed. The point stress and average stress criteria relate the notched strength of a laminate to the average strength of a relatively long tensile coupon. Tests of notched specimens in which microstrain gages have been placed at or near the edges of the holes have measured strains much larger that those measured in an unnotched tensile coupon. Orthotropic stress concentration analyses of failed notched laminates have also indicated that failure occurred at strains much larger than those experienced on tensile coupons with normal gage lengths. This suggests that the high strains at the edge of a hole can be related to the very short length of fiber subjected to these strains. Lockheed has attempted to correlate a series of tests of several laminates with holes ranging from 0.19 to 0.50 in. Although the average stress criterion correlated well with test results for hole sizes equal to or greater than 0.50 in., it over-estimated the laminate strength in the range of hole sizes from 0.19 to 0.38 in. It thus appears that a theory is needed that is based on the mechanics of failure and is more generally applicable to the range of hole sizes and the varieties of laminates found in aircraft construction.

  14. Electrochemical polishing of notches

    DOEpatents

    Kephart, A.R.; Alberts, A.H.

    1989-02-21

    An apparatus and method are disclosed for the selective electrochemical polishing of a lateral tip of a deep longitudinal notch in a work piece used to test crack initiation properties of materials. A DC power source is connected to the work piece and to an electrode disposed laterally along the distal end of an insulated body which is inserted in the longitudinal notch. The electrode and distal end of the body are disposed along the tip of the notch, but are spaced from the notch so as to provide a lateral passage for an electrolyte. The electrolyte is circulated through the passage so that the electrolyte only contacts the work piece adjacent the passage. Conveniently, the electrolyte is circulated by use of an inlet tube and an outlet tube provided at opposite ends of the passage. These tubes are preferably detachably located adjacent the ends of the passage and suitable seals are provided. A holding device including arms to which the tubes are attached is conveniently used to rapidly and easily locate the test specimen with the passage aligned with the tubes. The electrode is preferably a wire which is located in grooves along the distal end of the insulated body and up one side of the body or a plastic sheath insulated thin metal strip. 4 figs.

  15. Electrochemical polishing of notches

    DOEpatents

    Kephart, Alan R.; Alberts, Alfred H.

    1989-01-01

    An apparatus and method are disclosed for the selective electrochemical polishing of a lateral tip of a deep longitudinal notch in a work piece used to test crack initiation properties of materials. A DC power source is connected to the work piece and to an electrode disposed laterally along the distal end of an insulated body which is inserted in the longitudinal notch. The electrode and distal end of the body are disposed along the tip of the notch, but are spaced from the notch so as to provide a lateral passage for an electrolyte. The electrolyte is circulated through the passage so that the electrolyte only contacts the work piece adjacent the passage. Conveniently, the electrolyte is circulated by use of an inlet tube and an outlet tube provided at opposite ends of the passage. These tubes are preferably detachably located adjacent the ends of the passage and suitable seals are provided. A holding device including arms to which the tubes are attached is conveniently used to rapidly and easily locate the test specimen with the passage aligned with the tubes. The electrode is preferably a wire which is located in grooves along the distal end of the insulated body and up one side of the body or a plastic sheath insulated thin metal strip.

  16. Notch-Mediated Cell Adhesion

    PubMed Central

    Murata, Akihiko; Hayashi, Shin-Ichi

    2016-01-01

    Notch family members are generally recognized as signaling molecules that control various cellular responses in metazoan organisms. Early fly studies and our mammalian studies demonstrated that Notch family members are also cell adhesion molecules; however, information on the physiological roles of this function and its origin is limited. In this review, we discuss the potential present and ancestral roles of Notch-mediated cell adhesion in order to explore its origin and the initial roles of Notch family members dating back to metazoan evolution. We hypothesize that Notch family members may have initially emerged as cell adhesion molecules in order to mediate multicellularity in the last common ancestor of metazoan organisms. PMID:26784245

  17. Targeted gene therapy and cell reprogramming in Fanconi anemia

    PubMed Central

    Rio, Paula; Baños, Rocio; Lombardo, Angelo; Quintana-Bustamante, Oscar; Alvarez, Lara; Garate, Zita; Genovese, Pietro; Almarza, Elena; Valeri, Antonio; Díez, Begoña; Navarro, Susana; Torres, Yaima; Trujillo, Juan P; Murillas, Rodolfo; Segovia, Jose C; Samper, Enrique; Surralles, Jordi; Gregory, Philip D; Holmes, Michael C; Naldini, Luigi; Bueren, Juan A

    2014-01-01

    Gene targeting is progressively becoming a realistic therapeutic alternative in clinics. It is unknown, however, whether this technology will be suitable for the treatment of DNA repair deficiency syndromes such as Fanconi anemia (FA), with defects in homology-directed DNA repair. In this study, we used zinc finger nucleases and integrase-defective lentiviral vectors to demonstrate for the first time that FANCA can be efficiently and specifically targeted into the AAVS1 safe harbor locus in fibroblasts from FA-A patients. Strikingly, up to 40% of FA fibroblasts showed gene targeting 42 days after gene editing. Given the low number of hematopoietic precursors in the bone marrow of FA patients, gene-edited FA fibroblasts were then reprogrammed and re-differentiated toward the hematopoietic lineage. Analyses of gene-edited FA-iPSCs confirmed the specific integration of FANCA in the AAVS1 locus in all tested clones. Moreover, the hematopoietic differentiation of these iPSCs efficiently generated disease-free hematopoietic progenitors. Taken together, our results demonstrate for the first time the feasibility of correcting the phenotype of a DNA repair deficiency syndrome using gene-targeting and cell reprogramming strategies. PMID:24859981

  18. Differential sensitivities of transcription factor target genes underlie cell type-specific gene expression profiles

    PubMed Central

    Johnson, Kirby D.; Kim, Shin-Il; Bresnick, Emery H.

    2006-01-01

    Changes in transcription factor levels and activities dictate developmental fate. Such a change might affect the full ensemble of target genes for a factor or only uniquely sensitive targets. We investigated the relationship among activity of the hematopoietic transcription factor GATA-1, chromatin occupancy, and target gene sensitivity. Graded activation of GATA-1 in GATA-1-null cells revealed high-, intermediate-, and low-sensitivity targets. GATA-1 activity requirements for occupancy and transcription often correlated. A GATA-1 amino-terminal deletion mutant severely deregulated the low-sensitivity gene Tac-2. Thus, cells expressing different levels of a cell type-specific activator can have qualitatively distinct target gene expression patterns, and factor mutations preferentially deregulate low-sensitivity genes. Unlike other target genes, GATA-1-mediated Tac-2 regulation was bimodal, with activation followed by repression, and the coregulator Friend of GATA-1 (FOG-1) selectively mediated repression. A GATA-1 mutant defective in FOG-1 binding occupied a Tac-2 regulatory region at levels higher than wild-type GATA-1, whereas FOG-1 facilitated chromatin occupancy at a distinct target site. These results indicate that FOG-1 is a determinant of GATA factor target gene sensitivity by either facilitating or opposing chromatin occupancy. PMID:17043224

  19. Notch-EGFR/HER2 Bidirectional Crosstalk in Breast Cancer

    PubMed Central

    Baker, Andrew T.; Zlobin, Andrei; Osipo, Clodia

    2014-01-01

    The Notch pathway is a well-established mediator of cell–cell communication that plays a critical role in stem cell survival, self-renewal, cell fate decisions, tumorigenesis, invasion, metastasis, and drug resistance in a variety of cancers. An interesting form of crosstalk exists between the Notch receptor and the Epidermal Growth Factor Receptor Tyrosine Kinase family, which consists of HER-1, -2, -3, and -4. Overexpression of HER and/or Notch occurs in several human cancers including brain, lung, breast, ovary, and skin making them potent oncogenes capable of advancing malignant disease. Continued assessment of interplay between these two critical signaling networks uncovers new insight into mechanisms used by HER-driven cancer cells to exploit Notch as a compensatory pathway. The compensatory Notch pathway maintains HER-induced downstream signals transmitted to pathways such as Mitogen Activated Protein Kinase and Phosphatidylinositol 3-Kinase (PI3K), thereby allowing cancer cells to survive molecular targeted therapies, undergo epithelial to mesenchymal transitioning, and increase cellular invasion. Uncovering the critical crosstalk between the HER and Notch pathways can lead to improved screening for the expression of these oncogenes enabling patients to optimize their personal treatment options and predict potential treatment resistance. This review will focus on the current state of crosstalk between the HER and Notch receptors and the effectiveness of current therapies targeting HER-driven cancers. PMID:25566499

  20. Targeted Gene Activation Using RNA-Guided Nucleases.

    PubMed

    Brown, Alexander; Woods, Wendy S; Perez-Pinera, Pablo

    2017-01-01

    The discovery of the prokaryotic CRISPR-Cas (clustered regularly interspaced short palindromic repeats-CRISPR-associated) system and its adaptation for targeted manipulation of DNA in diverse species has revolutionized the field of genome engineering. In particular, the fusion of catalytically inactive Cas9 to any number of transcriptional activator domains has resulted in an array of easily customizable synthetic transcription factors that are capable of achieving robust, specific, and tunable activation of target gene expression within a wide variety of tissues and cells. This chapter describes key experimental design considerations, methods for plasmid construction, gene delivery protocols, and procedures for analysis of targeted gene activation in mammalian cell lines using CRISPR-Cas transcription factors. PMID:27662880

  1. Genome-wide expression profiling in the Drosophila eye reveals unexpected repression of Notch signaling by the JAK/STAT pathway

    PubMed Central

    Flaherty, Maria Sol; Zavadil, Jiri; Ekas, Laura A.; Bach, Erika A.

    2010-01-01

    Although the JAK/STAT pathway regulates numerous processes in vertebrates and invertebrates through modulating transcription, its functionally-relevant transcriptional targets remain largely unknown. With one jak and one stat (stat92E), Drosophila provides a powerful system for finding new JAK/STAT target genes. Genome-wide expression profiling on eye discs in which Stat92E is hyperactivated, revealed 584 differentially-regulated genes, including known targets domeless, socs36E and wingless. Other differentially-regulated genes (chinmo, lama, Mo25, Imp-L2, Serrate, Delta) were validated and may represent new Stat92E targets. Genetic experiments revealed that Stat92E cell-autonomously represses Serrate, which encodes a Notch ligand. Loss of Stat92E led to de-repression of Serrate in the dorsal eye, resulting in ectopic Notch signaling and aberrant eye growth there. Thus, our micro-array documents a new Stat92E target gene and a previously-unidentified inhibitory action of Stat92E on Notch signaling. These data suggest that this study will be a useful resource for the identification of additional Stat92E targets. PMID:19504457

  2. Targeting of AID-mediated sequence diversification to immunoglobulin genes.

    PubMed

    Kothapalli, Naga Rama; Fugmann, Sebastian D

    2011-04-01

    Activation-induced cytidine deaminase (AID) is a key enzyme for antibody-mediated immune responses. Antibodies are encoded by the immunoglobulin genes and AID acts as a transcription-dependent DNA mutator on these genes to improve antibody affinity and effector functions. An emerging theme in field is that many transcribed genes are potential targets of AID, presenting an obvious danger to genomic integrity. Thus there are mechanisms in place to ensure that mutagenic outcomes of AID activity are specifically restricted to the immunoglobulin loci. Cis-regulatory targeting elements mediate this effect and their mode of action is probably a combination of immunoglobulin gene specific activation of AID and a perversion of faithful DNA repair towards error-prone outcomes.

  3. Wt1a, Foxc1a, and the Notch mediator Rbpj Physically Interact and Regulate the Formation of Podocytes in Zebrafish

    PubMed Central

    O’Brien, Lori L.; Grimaldi, Michael; Kostun, Zachary; Wingert, Rebecca A.; Selleck, Rori; Davidson, Alan J.

    2011-01-01

    Podocytes help form the glomerular blood filtration barrier in the kidney and their injury or loss leads to renal disease. The Wilms’ tumor suppressor-1 (Wt1) and the FoxC1/2 transcription factors, as well as Notch signaling, have been implicated as important regulators of podocyte fate. It is not known whether these factors work in parallel or sequentially on different gene targets, or as higher-order transcriptional complexes on common genes. Here, we use the zebrafish to demonstrate that embryos treated with morpholinos against wt1a, foxc1a, or the Notch transcriptional mediator rbpj develop fewer podocytes, as determined by wt1b, hey1 and nephrin expression, while embryos deficient in any two of these factors completely lack podocytes. From GST-pull-downs and co-immunoprecipitation experiments we show that Wt1a, Foxc1a, and Rbpj can physically interact with each other, whereas only Rbpj binds to the Notch intracellular domain (NICD). In transactivation assays, combinations of Wt1, FoxC1/2, and NICD synergistically induce the Hey1 promoter, and have additive or repressive effects on the Podocalyxin promoter, depending on dosage. Taken together, these data suggest that Wt1, FoxC1/2, and Notch signaling converge on common target genes where they physically interact to regulate a podocyte-specific gene program. These findings further our understanding of the transcriptional circuitry responsible for podocyte formation and differentiation during kidney development. PMID:21871448

  4. Expression of PAX8 Target Genes in Papillary Thyroid Carcinoma

    PubMed Central

    Rosignolo, Francesca; Sponziello, Marialuisa; Durante, Cosimo; Puppin, Cinzia; Mio, Catia; Baldan, Federica; Di Loreto, Carla; Russo, Diego; Filetti, Sebastiano; Damante, Giuseppe

    2016-01-01

    PAX8 is a thyroid-specific transcription factor whose expression is dysregulated in thyroid cancer. A recent study using a conditional knock-out mouse model identified 58 putative PAX8 target genes. In the present study, we evaluated the expression of 11 of these genes in normal and tumoral thyroid tissues from patients with papillary thyroid cancer (PTC). ATP1B1, GPC3, KCNIP3, and PRLR transcript levels in tumor tissues were significantly lower in PTCs than in NT, whereas LCN2, LGALS1 and SCD1 expression was upregulated in PTC compared with NT. Principal component analysis of the expression of the most markedly dysregulated PAX8 target genes was able to discriminate between PTC and NT. Immunohistochemistry was used to assess levels of proteins encoded by the two most dyregulated PAX8 target genes, LCN2 and GPC3. Interestingly, GPC3 was detectable in all of the NT samples but none of the PTC samples. Collectively, these findings point to significant PTC-associated dysregulation of several PAX8 target genes, supporting the notion that PAX8-regulated molecular cascades play important roles during thyroid tumorigenesis. PMID:27249794

  5. Gene Body Methylation can alter Gene Expression and is a Therapeutic Target in Cancer

    PubMed Central

    Yang, Xiaojing; Han, Han; De Carvalho, Daniel D.; Lay, Fides D.; Jones, Peter A.; Liang, Gangning

    2014-01-01

    SUMMARY DNA methylation in promoters is well known to silence genes and is the presumed therapeutic target of methylation inhibitors. Gene body methylation is positively correlated with expression yet its function is unknown. We show that 5-aza-2'-deoxycytidine treatment not only reactivates genes but decreases the over-expression of genes, many of which are involved in metabolic processes regulated by c-MYC. Down-regulation is caused by DNA demethylation of the gene bodies and restoration of high levels of expression requires remethylation by DNMT3B. Gene body methylation may therefore be an unexpected therapeutic target for DNA methylation inhibitors, resulting in the normalization of gene over-expression induced during carcinogenesis. Our results provide direct evidence for a causal relationship between gene body methylation and transcription. PMID:25263941

  6. Dual Roles of O-Glucose Glycans Redundant with Monosaccharide O-Fucose on Notch in Notch Trafficking.

    PubMed

    Matsumoto, Kenjiroo; Ayukawa, Tomonori; Ishio, Akira; Sasamura, Takeshi; Yamakawa, Tomoko; Matsuno, Kenji

    2016-06-24

    Notch is a transmembrane receptor that mediates cell-cell interactions and controls various cell-fate specifications in metazoans. The extracellular domain of Notch contains multiple epidermal growth factor (EGF)-like repeats. At least five different glycans are found in distinct sites within these EGF-like repeats. The function of these individual glycans in Notch signaling has been investigated, primarily by disrupting their individual glycosyltransferases. However, we are just beginning to understand the potential functional interactions between these glycans. Monosaccharide O-fucose and O-glucose trisaccharide (O-glucose-xylose-xylose) are added to many of the Notch EGF-like repeats. In Drosophila, Shams adds a xylose specifically to the monosaccharide O-glucose. We found that loss of the terminal dixylose of O-glucose-linked saccharides had little effect on Notch signaling. However, our analyses of double mutants of shams and other genes required for glycan modifications revealed that both the monosaccharide O-glucose and the terminal dixylose of O-glucose-linked saccharides function redundantly with the monosaccharide O-fucose in Notch activation and trafficking. The terminal dixylose of O-glucose-linked saccharides and the monosaccharide O-glucose were required in distinct Notch trafficking processes: Notch transport from the apical plasma membrane to adherens junctions, and Notch export from the endoplasmic reticulum, respectively. Therefore, the monosaccharide O-glucose and terminal dixylose of O-glucose-linked saccharides have distinct activities in Notch trafficking, although a loss of these activities is compensated for by the presence of monosaccharide O-fucose. Given that various glycans attached to a protein motif may have redundant functions, our results suggest that these potential redundancies may lead to a serious underestimation of glycan functions. PMID:27129198

  7. Dual Roles of O-Glucose Glycans Redundant with Monosaccharide O-Fucose on Notch in Notch Trafficking.

    PubMed

    Matsumoto, Kenjiroo; Ayukawa, Tomonori; Ishio, Akira; Sasamura, Takeshi; Yamakawa, Tomoko; Matsuno, Kenji

    2016-06-24

    Notch is a transmembrane receptor that mediates cell-cell interactions and controls various cell-fate specifications in metazoans. The extracellular domain of Notch contains multiple epidermal growth factor (EGF)-like repeats. At least five different glycans are found in distinct sites within these EGF-like repeats. The function of these individual glycans in Notch signaling has been investigated, primarily by disrupting their individual glycosyltransferases. However, we are just beginning to understand the potential functional interactions between these glycans. Monosaccharide O-fucose and O-glucose trisaccharide (O-glucose-xylose-xylose) are added to many of the Notch EGF-like repeats. In Drosophila, Shams adds a xylose specifically to the monosaccharide O-glucose. We found that loss of the terminal dixylose of O-glucose-linked saccharides had little effect on Notch signaling. However, our analyses of double mutants of shams and other genes required for glycan modifications revealed that both the monosaccharide O-glucose and the terminal dixylose of O-glucose-linked saccharides function redundantly with the monosaccharide O-fucose in Notch activation and trafficking. The terminal dixylose of O-glucose-linked saccharides and the monosaccharide O-glucose were required in distinct Notch trafficking processes: Notch transport from the apical plasma membrane to adherens junctions, and Notch export from the endoplasmic reticulum, respectively. Therefore, the monosaccharide O-glucose and terminal dixylose of O-glucose-linked saccharides have distinct activities in Notch trafficking, although a loss of these activities is compensated for by the presence of monosaccharide O-fucose. Given that various glycans attached to a protein motif may have redundant functions, our results suggest that these potential redundancies may lead to a serious underestimation of glycan functions.

  8. Cloning, characterization and targeting of the mouse HEXA gene

    SciTech Connect

    Wakamatsu, N.; Trasler, J.M.; Gravel, R.A.

    1994-09-01

    The HEXA gene, encoding the {alpha} subunit of {beta}-hexosaminidase A, is essential for the metabolism of ganglioside G{sub M2}, and defects in this gene cause Tay-Sachs disease in humans. To elucidate the role of the gene in the nervous system of the mouse and to establish a mouse model of Tay-Sachs disease, we have cloned and characterized the HEXA gene and targeted a disruption of the gene in mouse ES cells. The mouse HEXA gene spans {approximately}26 kb and consists of 14 exons, similar to the human gene. A heterogeneous transcription initiation site was identified 21-42 bp 5{prime} of the initiator ATG, with two of the sites fitting the consensus CTCA (A = start) as seen for some weak initiator systems. Promoter analysis showed that the first 150 bp 5{prime} of the ATG contained 85% of promoter activity observed in constructs containing up to 1050 bp of 5{prime} sequence. The active region contained a sequence matching that of the adenovirus major late promoter upstream element factor. A survey of mouse tissues showed that the highest mRNA levels were in (max to min): testis (5.5 x brain cortex), adrenal, epididymis, heart, brain, lung, kidney, and liver (0.3 x brain cortex). A 12 kb BstI/SalI fragment containing nine exons was disrupted with the insertion of the bacterial neo{sup r} gene in exon 11 and was targeted into 129/Sv ES cells by homologous recombination. Nine of 153 G418 resistant clones were correctly targeted as confirmed by Southern blotting. The heterozygous ES cells were microinjected into mouse blastocysts and implanted into pseudo-pregnant mice. Nine male chimeric mice, showing that 40-95% chimerism for the 129/Sv agouti coat color marker, are being bred in an effort to generate germline transmission of the disrupted HEXA gene.

  9. Fungal virulence genes as targets for antifungal chemotherapy.

    PubMed Central

    Perfect, J R

    1996-01-01

    Fungal virulence genes have now met the age of molecular pathogenesis. The definition of virulence genes needs to be broad so that it encompasses the focus on molecular antifungal targets and vaccine epitopes. However, in the broad but simple definition of a virulence gene, there will be many complex genetic and host interactions which investigators will need to carefully define. Nevertheless, with the increasing numbers of serious fungal infections produced by old and newly reported organisms, the paucity of present antifungal drugs, and the likelihood of increasing drug resistance, the need for investigations into understanding fungal virulence at the molecular level has never been more important. PMID:8807043

  10. Metabolic reprogramming induces resistance to anti-NOTCH1 therapies in acute lymphoblastic leukemia

    PubMed Central

    Herranz, Daniel; Ambesi-Impiombato, Alberto; Sudderth, Jessica; Sánchez-Martín, Marta; Belver, Laura; Tosello, Valeria; Xu, Luyao; Wendorff, Agnieszka A.; Castillo, Mireia; Haydu, J. Erika; Márquez, Javier; Matés, José M.; Kung, Andrew L.; Rayport, Stephen; Cordon-Cardo, Carlos; DeBerardinis, Ralph J.; Ferrando, Adolfo A.

    2015-01-01

    Activating mutations in NOTCH1 are common in T-cell acute lymphoblastic leukemia (TALL). Here we identify glutaminolysis as a critical pathway for leukemia cell growth downstream of NOTCH1 and a key determinant of clinical response to anti-NOTCH1 therapies. Mechanistically, inhibition of NOTCH1 signaling in T-ALL induces a metabolic shutdown with prominent inhibition of glutaminolysis and triggers autophagy as a salvage pathway supporting leukemia cell metabolism. Consequently, both inhibition of glutaminolysis and inhibition of autophagy strongly and synergistically enhance the antileukemic effects of anti-NOTCH1 therapies. Moreover, we demonstrate that Pten loss induces increased glycolysis and consequently rescues leukemic cell metabolism abrogating the antileukemic effects of NOTCH1 inhibition. Overall, these results identify glutaminolysis as a major node in cancer metabolism controlled by NOTCH1 and as therapeutic target for the treatment of T-ALL. PMID:26390244

  11. Engineering nucleases for gene targeting: safety and regulatory considerations.

    PubMed

    Pauwels, Katia; Podevin, Nancy; Breyer, Didier; Carroll, Dana; Herman, Philippe

    2014-01-25

    Nuclease-based gene targeting (NBGT) represents a significant breakthrough in targeted genome editing since it is applicable from single-celled protozoa to human, including several species of economic importance. Along with the fast progress in NBGT and the increasing availability of customized nucleases, more data are available about off-target effects associated with the use of this approach. We discuss how NBGT may offer a new perspective for genetic modification, we address some aspects crucial for a safety improvement of the corresponding techniques and we also briefly relate the use of NBGT applications and products to the regulatory oversight.

  12. Notch-signalling is required for head regeneration and tentacle patterning in Hydra.

    PubMed

    Münder, Sandra; Tischer, Susanne; Grundhuber, Maresa; Büchels, Nathalie; Bruckmeier, Nadine; Eckert, Stefanie; Seefeldt, Carolin A; Prexl, Andrea; Käsbauer, Tina; Böttger, Angelika

    2013-11-01

    Local self-activation and long ranging inhibition provide a mechanism for setting up organising regions as signalling centres for the development of structures in the surrounding tissue. The adult hydra hypostome functions as head organiser. After hydra head removal it is newly formed and complete heads can be regenerated. The molecular components of this organising region involve Wnt-signalling and β-catenin. However, it is not known how correct patterning of hypostome and tentacles are achieved in the hydra head and whether other signals in addition to HyWnt3 are needed for re-establishing the new organiser after head removal. Here we show that Notch-signalling is required for re-establishing the organiser during regeneration and that this is due to its role in restricting tentacle activation. Blocking Notch-signalling leads to the formation of irregular head structures characterised by excess tentacle tissue and aberrant expression of genes that mark the tentacle boundaries. This indicates a role for Notch-signalling in defining the tentacle pattern in the hydra head. Moreover, lateral inhibition by HvNotch and its target HyHes are required for head regeneration and without this the formation of the β-catenin/Wnt dependent head organiser is impaired. Work on prebilaterian model organisms has shown that the Wnt-pathway is important for setting up signalling centres for axial patterning in early multicellular animals. Our data suggest that the integration of Wnt-signalling with Notch-Delta activity was also involved in the evolution of defined body plans in animals.

  13. Chlorotoxin labeled magnetic nanovectors for targeted gene delivery to glioma.

    PubMed

    Kievit, Forrest M; Veiseh, Omid; Fang, Chen; Bhattarai, Narayan; Lee, Donghoon; Ellenbogen, Richard G; Zhang, Miqin

    2010-08-24

    Glioma accounts for 80% of brain tumors and currently remains one of the most lethal forms of cancers. Gene therapy could potentially improve the dismal prognosis of patients with glioma, but this treatment modality has not yet reached the bedside from the laboratory due to the lack of safe and effective gene delivery vehicles. In this study we investigate targeted gene delivery to C6 glioma cells in a xenograft mouse model using chlorotoxin (CTX) labeled nanoparticles. The developed nanovector consists of an iron oxide nanoparticle core, coated with a copolymer of chitosan, polyethylene glycol (PEG), and polyethylenimine (PEI). Green fluorescent protein (GFP) encoding DNA was bound to these nanoparticles, and CTX was then attached using a short PEG linker. Nanoparticles without CTX were also prepared as a control. Mice bearing C6 xenograft tumors were injected intravenously with the DNA-bound nanoparticles. Nanoparticle accumulation in the tumor site was monitored using magnetic resonance imaging and analyzed by histology, and GFP gene expression was monitored through Xenogen IVIS fluorescence imaging and confocal fluorescence microscopy. Interestingly, the CTX did not affect the accumulation of nanoparticles at the tumor site but specifically enhanced their uptake into cancer cells as evidenced by higher gene expression. These results indicate that this targeted gene delivery system may potentially improve treatment outcome of gene therapy for glioma and other deadly cancers.

  14. Rescuing the Failing Heart by Targeted Gene Transfer

    PubMed Central

    Kawase, Yoshiaki; Ladage, Dennis; Hajjar, Roger J.

    2011-01-01

    Congestive heart failure is a major cause of morbidity and mortality in the US. While progress in conventional treatments is making steady and incremental gains to reduce heart failure mortality, there is a critical need to explore new therapeutic approaches. Gene therapy was initially applied in the clinical setting for inherited monogenic disorders. It is now apparent that gene therapy has broader potential that also includes acquired polygenic diseases, such as congestive heart failure. Recent advances in understanding of the molecular basis of myocardial dysfunction, together with the evolution of increasingly efficient gene transfer technology, has placed heart failure within reach of gene-based therapy. Furthermore, the recent successful and safe completion of a phase 2 trial targeting the sarcoplasmic reticulum calcium ATPase pump (SERCA2a) along with the start of more recent phase 1 trials usher a new era for gene therapy for the treatment of heart failure. PMID:21371634

  15. Dynamic Changes in microRNAs may Regulate Robustness of Wnt/Notch Signaling

    NASA Astrophysics Data System (ADS)

    Gunaratne, Preethi

    2008-03-01

    The mechanisms by which highly reproducible patterns are formed during embryonic development and organismal evolution despite stochasticity at the single cell level is one of the remaining mysteries in Biology. It has been proposed that a hidden layer of regulation formed through the interaction of microRNAs with protein coding gene networks maybe responsible. Recently developed next generation sequencing technologies afford an unprecedented opportunity to uncover novel aspects of miRNA function and evolution. We find extensive heterogeneity in sequences that correspond to mmu-let-7 (targets Wnt1) and mmu-miR-191 (targets Notch1). Approximately 20% of let-7 and miR-191 have undergone modifications to increase stability and binding to the Wnt1 and Notch1 targets and are likely to be destroyed. In contrast, 80% bind the targets with imperfect complementarity and lower stability and are likely to be sequestered and prevented from forming protein. We propose that these two species together form a highly fluid system that is able to absorb stochastic perturbations in gene expression. A gene that goes on to be translated into functional protein therefore must escape both buffers by significantly high expression.

  16. Correction of human. beta. sup S -globin gene by gene targeting

    SciTech Connect

    Shesely, E.G.; Hyungsuk Kim; Shehee, W.R.; Smithies, O. ); Papayannopoulou, T. ); Popovich, B.W. )

    1991-05-15

    As a step toward using gene targeting for gene therapy, the authors have corrected a human {beta}{sup S}-globin gene to the normal {beta}{sup A} allele by homologous recombination in the mouse-human hybrid cell line BSM. BSM is derived from a mouse erythroleukemia cell line and carries a single human chromosome 11 with the {beta}{sup S}-globin allele. A {beta}{sup A}-globin targeting construct containing a unique oligomer and a neomycin-resistance gene was electroporated into the BSM cells, which were then placed under G418 selection. Then 126 resulting pools containing a total {approx}29,000 G418-resistant clones were screened by PCR for the presence of a targeted recombinant: 3 positive pools were identified. A targeted clone was isolated by replating one of the positive pools into smaller pools and rescreening by PCR, followed by dilution cloning. Southern blot analysis demonstrated that the isolated clone had been targeted as planned. The correction of the {beta}{sup S} allele to {beta}{sup A} was confirmed both by allele-specific PCR and by allele-specific antibodies. Expression studies comparing the uninduced and induced RNA levels in unmodified BSM cells and in the targeted clone showed no significant alteration in the ability of the targeted clone to undergo induction, despite the potentially disrupting presence of a transcriptionally active neomycin gene 5{prime} to the human {beta}{sup A}-globin gene. Thus gene targeting can correct a {beta}{sup S} allele to {beta}{sup A}, and the use of a selectable helper gene need not significantly interfere with the induction of the corrected gene.

  17. Bacteriophages and medical oncology: targeted gene therapy of cancer.

    PubMed

    Bakhshinejad, Babak; Karimi, Marzieh; Sadeghizadeh, Majid

    2014-08-01

    Targeted gene therapy of cancer is of paramount importance in medical oncology. Bacteriophages, viruses that specifically infect bacterial cells, offer a variety of potential applications in biomedicine. Their genetic flexibility to go under a variety of surface modifications serves as a basis for phage display methodology. These surface manipulations allow bacteriophages to be exploited for targeted delivery of therapeutic genes. Moreover, the excellent safety profile of these viruses paves the way for their potential use as cancer gene therapy platforms. The merge of phage display and combinatorial technology has led to the emergence of phage libraries turning phage display into a high throughput technology. Random peptide libraries, as one of the most frequently used phage libraries, provide a rich source of clinically useful peptide ligands. Peptides are known as a promising category of pharmaceutical agents in medical oncology that present advantages such as inexpensive synthesis, efficient tissue penetration and the lack of immunogenicity. Phage peptide libraries can be screened, through biopanning, against various targets including cancer cells and tissues that results in obtaining cancer-homing ligands. Cancer-specific peptides isolated from phage libraries show huge promise to be utilized for targeting of various gene therapy vectors towards malignant cells. Beyond doubt, bacteriophages will play a more impressive role in the future of medical oncology.

  18. ALS mutations in TLS/FUS disrupt target gene expression.

    PubMed

    Coady, Tristan H; Manley, James L

    2015-08-15

    Amyotrophic lateral sclerosis (ALS) is caused by mutations in a number of genes, including the gene encoding the RNA/DNA-binding protein translocated in liposarcoma or fused in sarcoma (TLS/FUS or FUS). Previously, we identified a number of FUS target genes, among them MECP2. To investigate how ALS mutations in FUS might impact target gene expression, we examined the effects of several FUS derivatives harboring ALS mutations, such as R521C (FUS(C)), on MECP2 expression in transfected human U87 cells. Strikingly, FUS(C) and other mutants not only altered MECP2 alternative splicing but also markedly increased mRNA abundance, which we show resulted from sharply elevated stability. Paradoxically, however, MeCP2 protein levels were significantly reduced in cells expressing ALS mutant derivatives. Providing a parsimonious explanation for these results, biochemical fractionation and in vivo localization studies revealed that MECP2 mRNA colocalized with cytoplasmic FUS(C) in insoluble aggregates, which are characteristic of ALS mutant proteins. Together, our results establish that ALS mutations in FUS can strongly impact target gene expression, reflecting a dominant effect of FUS-containing aggregates.

  19. Notch-1 promotes breast cancer cells proliferation by regulating LncRNA GAS5

    PubMed Central

    Pei, Jing; Wang, Benzhong

    2015-01-01

    Background: Notch signaling is indicated as novel therapeutic targets to prevent recurrence of breast cancer. LncRNAs were identified as downstream target of Notch pathway. However, the exact mechanisms involved in Notch signaling, lncRNAs and breast cancer remain to be explained. Objective: This original research aimed to determine the prognostic implications of Notch-1 for breast cancer, and explain mechanisms involved in regulation of lnRNA GAS5 by Notch-1, and identify the function of this mechanism on breast cancer. Method: Thirty breast cancer patients were included from The First Affiliated Hospital of Anhui Medical University (China) since January 2006 in this study. The mRNA level by RT-PCR and protein level of Notch-1 by western blot in tumor tissues and adjacent normal tissues were evaluated and 5-year survival analysis was applied to examine the significance of Notch-1. The levels of ten reported lncRNAs were determined by RT-PCR, and subsequently linear analysis was applied to analyze the relationship between these four unique lncRNAs and protein level of Notch-1, which identified the most relevant lncRNA GAS5 with Notch-1 in breast cancer. Subsequently, Notch1-siRNA was applied to influence the expression of Notch-1 in T47D, then the level of RSA5 was measured by RT-PCR, and CCK-8 assay was applied to measure the proliferation of T47D cells. Results: High level of Notch-1 provided a poor prognosis in breast cancer. Interference of Notch-1 significantly suppressed proliferation of T47D cell (P < 0.05), and significantly increased the level of GAS5. Conclusion: Notch-1 promotes breast cancer cells proliferation by regulating LncRNA GAS5. PMID:26550436

  20. Biological therapy induces expression changes in Notch pathway in psoriasis.

    PubMed

    Skarmoutsou, Evangelia; Trovato, Chiara; Granata, Mariagrazia; Rossi, Giulio A; Mosca, Ambra; Longo, Valentina; Gangemi, Pietro; Pettinato, Maurizio; D'Amico, Fabio; Mazzarino, Maria Clorinda

    2015-12-01

    Psoriasis is a chronic inflammatory skin disease, characterized by hyperproliferation of keratinocytes and by skin infiltration of activated T cells. To date, the pathophysiology of psoriasis has not yet been fully elucidated. The Notch pathway plays a determinant role in cell fate determination, proliferation, differentiation, immune cell development and function. Many biological agents, used in the treatment of psoriasis, include TFN-α inhibitors, such as etanercept, adalimumab, and anti IL-12/IL-23 p40 antibody, such as ustekinumab. This study aimed to determine mRNA expression levels by real-time RT-PCR, and protein expression levels, analysed by Western blot and immunohistochemistry, of some components of the Notch pathway, such as NOTCH1, NOTCH2, JAGGED1, and HES1 after biological treatments in psoriatic patients. mRNA and protein levels of NOTCH1, NOTCH2, JAGGED1 and HES1 were upregulated in skin samples from untreated psoriatic patients compared with normal controls. Biological therapy showed to downregulate differently the protein expression levels of the molecules under study. Our study suggests that Notch pathway components might be a potential therapeutic target against psoriasis.

  1. Notch3 signaling promotes the development of pulmonary arterial hypertension.

    PubMed

    Li, Xiaodong; Zhang, Xiaoxue; Leathers, Robin; Makino, Ayako; Huang, Chengqun; Parsa, Pouria; Macias, Jesus; Yuan, Jason X-J; Jamieson, Stuart W; Thistlethwaite, Patricia A

    2009-11-01

    Notch receptor signaling is implicated in controlling smooth muscle cell proliferation and in maintaining smooth muscle cells in an undifferentiated state. Pulmonary arterial hypertension is characterized by excessive vascular resistance, smooth muscle cell proliferation in small pulmonary arteries, leading to elevation of pulmonary vascular resistance, right ventricular failure and death. Here we show that human pulmonary hypertension is characterized by overexpression of NOTCH3 in small pulmonary artery smooth muscle cells and that the severity of disease in humans and rodents correlates with the amount of NOTCH3 protein in the lung. We further show that mice with homozygous deletion of Notch3 do not develop pulmonary hypertension in response to hypoxic stimulation and that pulmonary hypertension can be successfully treated in mice by administration of N-[N-(3,5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester (DAPT), a gamma-secretase inhibitor that blocks activation of Notch3 in smooth muscle cells. We show a mechanistic link from NOTCH3 receptor signaling through the Hairy and enhancer of Split-5 (HES-5) protein to smooth muscle cell proliferation and a shift to an undifferentiated smooth muscle cell phenotype. These results suggest that the NOTCH3-HES-5 signaling pathway is crucial for the development of pulmonary arterial hypertension and provide a target pathway for therapeutic intervention. PMID:19855400

  2. [The hair follicle as a target for gene therapy].

    PubMed

    Cotsarelis, G

    2002-05-01

    The hair follicle possesses progenitor cells required for continuous hair follicle cycling and for epidermal keratinocytes, melanocytes and Langerhans cells. These different cell types can be the target of topical gene delivery in the skin of the mouse. Using a combination of liposomes and DNA, we demonstrate the feasibility of targeting hair follicle cells in human scalp xenografts. We consider liposome composition and stage of the hair cycle as important parameters influencing transfection of human hair follicles. Transfection is possible only during the early anagen phase. Factors and obstacles for the use of gene therapy in treating alopecia and skin diseases are discussed. A theoretical framework for future treatment of cutaneous and systemic disorders using gene therapy is presented.

  3. Nuclear gene targeting in Chlamydomonas as exemplified by disruption of the PHOT gene.

    PubMed

    Zorin, Boris; Lu, Yinghong; Sizova, Irina; Hegemann, Peter

    2009-03-01

    Chlamydomonas reinhardtii is the most powerful photosynthetic eukaryotic unicellular model organism. However, its potential is not fully exploitable since as in most green plants specific targeting of nuclear genes is not routinely possible. Recently, we have shown by repair of an introduced truncated model gene that transformation of Chlamydomonas with single stranded DNA greatly suppresses random integration of the DNA in the genome whereas homologous recombination (HR) is left unchanged. However, endogenous genes still could not be targeted. Here we present optimized transformation conditions that further improved HR and suppressed non-homologous DNA integration (NHI). The improved transformation strategy allowed us now to specifically inactivate in two different Chlamydomonas strains the nuclear PHOT gene, which encodes for the blue light photoreceptor phototropin (PHOT). The option to target moderately expressed Chlamydomonas nuclear genes with high efficiency now further improves the utility of this this alga for basic science and biotechnology.

  4. Glycogen synthase kinase 3 beta positively regulates Notch signaling in vascular smooth muscle cells: role in cell proliferation and survival.

    PubMed

    Guha, Shaunta; Cullen, John P; Morrow, David; Colombo, Alberto; Lally, Caitríona; Walls, Dermot; Redmond, Eileen M; Cahill, Paul A

    2011-09-01

    The role of glycogen synthase kinase 3 beta (GSK-3β) in modulating Notch control of vascular smooth muscle cell (vSMC) growth (proliferation and apoptosis) was examined in vitro under varying conditions of cyclic strain and validated in vivo following changes in medial tension and stress. Modulation of GSK-3β in vSMC following ectopic expression of constitutively active GSK-3β, siRNA knockdown and pharmacological inhibition with SB-216763 demonstrated that GSK-3β positively regulates Notch intracellular domain expression, CBF-1/RBP-Jκ transactivation and downstream target gene mRNA levels, while concomitantly promoting vSMC proliferation and inhibiting apoptosis. In contrast, inhibition of GSK-3β attenuated Notch signaling and decreased vSMC proliferation and survival. Exposure of vSMC to cyclic strain environments in vitro using both a Flexercell™ Tension system and a novel Sylgard™ phantom vessel following bare metal stent implantation revealed that cyclic strain inhibits GSK-3β activity independent of p42/p44 MAPK and p38 activation concomitant with reduced Notch signaling and decreased vSMC proliferation and survival. Exposure of vSMC to changes in medial strain microenvironments in vivo following carotid artery ligation revealed that enhanced GSK-3β activity was predominantly localized to medial and neointimal vSMC concomitant with increased Notch signaling, proliferating nuclear antigen and decreased Bax expression, respectively, as vascular remodeling progressed. GSK-3β is an important modulator of Notch signaling leading to altered vSMC cell growth where low strain/tension microenvironments prevail.

  5. MiR-433 inhibits retinoblastoma malignancy by suppressing Notch1 and PAX6 expression.

    PubMed

    Li, Xiaohua; Yang, Lan; Shuai, Tianjiao; Piao, Tianhua; Wang, Rui

    2016-08-01

    Retinoblastoma (RB) is the most frequent primary intraocular cancer. It has been demonstrated by previous studies that retinoblastoma is initiated primarily by the inactivation of the retinoblastoma Rb1 gene in retinal cells. However, additional genetic alterations than Rb1 mutation could play important roles in the process of transforming benign retinal cells into retinoblastoma tumor cells. In this study, we identified that microRNA miR-433 is one of such genetic factors. We found that the expression levels of miR-433 were downregulated in RB tissues. We also determined that miR-433 negatively regulated RB cell proliferation, migration and invasion, and induced cell cycle arrest and apoptosis of RB cells. We used bioinformatics method to predict and confirmed that Notch1 and PAX6 were miR-433 target genes in RB cells. Importantly, we demonstrated that restoration of Notch1 and PAX6 expression partially rescued the inhibition of cell proliferation and metastasis induced by miR-433 overexpression, suggesting that miR-433 regulates RB cell proliferation and metastasis through suppressing the expression of Notch1 and PAX6. PMID:27470361

  6. Mutations in NOTCH1 cause Adams-Oliver syndrome.

    PubMed

    Stittrich, Anna-Barbara; Lehman, Anna; Bodian, Dale L; Ashworth, Justin; Zong, Zheyuan; Li, Hong; Lam, Patricia; Khromykh, Alina; Iyer, Ramaswamy K; Vockley, Joseph G; Baveja, Rajiv; Silva, Ermelinda Santos; Dixon, Joanne; Leon, Eyby L; Solomon, Benjamin D; Glusman, Gustavo; Niederhuber, John E; Roach, Jared C; Patel, Millan S

    2014-09-01

    Notch signaling determines and reinforces cell fate in bilaterally symmetric multicellular eukaryotes. Despite the involvement of Notch in many key developmental systems, human mutations in Notch signaling components have mainly been described in disorders with vascular and bone effects. Here, we report five heterozygous NOTCH1 variants in unrelated individuals with Adams-Oliver syndrome (AOS), a rare disease with major features of aplasia cutis of the scalp and terminal transverse limb defects. Using whole-genome sequencing in a cohort of 11 families lacking mutations in the four genes with known roles in AOS pathology (ARHGAP31, RBPJ, DOCK6, and EOGT), we found a heterozygous de novo 85 kb deletion spanning the NOTCH1 5' region and three coding variants (c.1285T>C [p.Cys429Arg], c.4487G>A [p.Cys1496Tyr], and c.5965G>A [p.Asp1989Asn]), two of which are de novo, in four unrelated probands. In a fifth family, we identified a heterozygous canonical splice-site variant (c.743-1 G>T) in an affected father and daughter. These variants were not present in 5,077 in-house control genomes or in public databases. In keeping with the prominent developmental role described for Notch1 in mouse vasculature, we observed cardiac and multiple vascular defects in four of the five families. We propose that the limb and scalp defects might also be due to a vasculopathy in NOTCH1-related AOS. Our results suggest that mutations in NOTCH1 are the most common cause of AOS and add to a growing list of human diseases that have a vascular and/or bony component and are caused by alterations in the Notch signaling pathway. PMID:25132448

  7. A novel promoterless gene targeting vector to efficiently disrupt PRNP gene in cattle.

    PubMed

    Wang, Shaohua; Zhang, Kun; Ding, Fangrong; Zhao, Rui; Li, Song; Li, Rong; Xu, Lingling; Song, Chi; Dai, Yunping; Li, Ning

    2013-02-20

    The PRNP gene encodes a cellular protein named prion, whose misfolded form has been implicated in a number of neuropathic diseases in mammals such as the Bovine Spongiform Encephalopathy (BSE) in cattle. BSE has brought devastating impact on the world economy and human health. Recently, several groups have performed the gene targeting strategy to disrupt the PRNP gene in bovine fibroblast cells and produce BSE-resistant cattle by somatic cell nuclear transfer (SCNT). However, the enrichment efficiency of the gene targeting vector was low. Here, we constructed a novel promoterless gene targeting vector to sequentially disrupt the PRNP gene in bovine fibroblast cells and generate gene targeted cattle by SCNT. The enrichment efficiency of the novel vector was 100% and 60%, respectively. After nuclear transfer, no significant difference was found in the rate of cleavage and blastocyst formation between the knockout and wild type cloned embryos. One PRNP⁺/⁻ calf was born with no obvious abnormal development by now. Fusion RT-PCR and real-time PCR showed one allele of the PRNP gene was functionally disrupted, and the mRNA expression reduced dramatically in the PRNP⁺/⁻ cattle. The reconstituted PRNP⁻/⁻ embryos showed double alleles disruption, and no difference in the rate of cleavage and blastocyst formation.

  8. RFMirTarget: Predicting Human MicroRNA Target Genes with a Random Forest Classifier

    PubMed Central

    Mendoza, Mariana R.; da Fonseca, Guilherme C.; Loss-Morais, Guilherme; Alves, Ronnie; Margis, Rogerio; Bazzan, Ana L. C.

    2013-01-01

    MicroRNAs are key regulators of eukaryotic gene expression whose fundamental role has already been identified in many cell pathways. The correct identification of miRNAs targets is still a major challenge in bioinformatics and has motivated the development of several computational methods to overcome inherent limitations of experimental analysis. Indeed, the best results reported so far in terms of specificity and sensitivity are associated to machine learning-based methods for microRNA-target prediction. Following this trend, in the current paper we discuss and explore a microRNA-target prediction method based on a random forest classifier, namely RFMirTarget. Despite its well-known robustness regarding general classifying tasks, to the best of our knowledge, random forest have not been deeply explored for the specific context of predicting microRNAs targets. Our framework first analyzes alignments between candidate microRNA-target pairs and extracts a set of structural, thermodynamics, alignment, seed and position-based features, upon which classification is performed. Experiments have shown that RFMirTarget outperforms several well-known classifiers with statistical significance, and that its performance is not impaired by the class imbalance problem or features correlation. Moreover, comparing it against other algorithms for microRNA target prediction using independent test data sets from TarBase and starBase, we observe a very promising performance, with higher sensitivity in relation to other methods. Finally, tests performed with RFMirTarget show the benefits of feature selection even for a classifier with embedded feature importance analysis, and the consistency between relevant features identified and important biological properties for effective microRNA-target gene alignment. PMID:23922946

  9. Analysis of Dominant Enhancers and Suppressors of Activated Notch in Drosophila

    PubMed Central

    Verheyen, E. M.; Purcell, K. J.; Fortini, M. E.; Artavanis-Tsakonas, S.

    1996-01-01

    The Notch receptor controls cell fate decisions throughout Drosophila development. Truncated, ligand-independent forms of this protein delay or block differentiation. We have previously shown that expression of the intracellular domain of the receptor under the control of the sevenless enhancer/promoter induces a rough eye phenotype in the adult fly. Analysis of the resultant cellular transformations suggested that this form of Notch acts as a constitutively activated receptor. To identify gene products that interact with Notch, a second-site mutagenesis screen was performed to isolate enhancers and suppressors of the eye phenotype caused by expression of these activated Notch molecules. We screened 137,000 mutagenized flies and recovered 290 dominant modifiers. Many new alleles of previously identified genes were isolated, as were mutations defining novel loci that may function in the Notch signaling pathway. We discuss the data with respect to known features of Notch receptor signaling and Drosophila eye development. PMID:8913755

  10. Pathophysiology of gene-targeted mouse models for cystic fibrosis.

    PubMed

    Grubb, B R; Boucher, R C

    1999-01-01

    Pathophysiology of Gene-Targeted Mouse Models for Cystic Fibrosis. Physiol. Rev. 79, Suppl.: S193-S214, 1999. - Mutations in the gene causing the fatal disease cystic fibrosis (CF) result in abnormal transport of several ions across a number of epithelial tissues. In just 3 years after this gene was cloned, the first CF mouse models were generated. The CF mouse models generated to date have provided a wealth of information on the pathophysiology of the disease in a variety of organs. Heterogeneity of disease in the mouse models is due to the variety of gene-targeting strategies used in the generation of the CF mouse models as well as the diversity of the murine genetic background. This paper reviews the pathophysiology in the tissues and organs (gastrointestinal, airway, hepatobiliary, pancreas, reproductive, and salivary tissue) involved in the disease in the various CF mouse models. Marked similarities to and differences from the human disease have been observed in the various murine models. Some of the CF mouse models accurately reflect the ion-transport abnormalities and disease phenotype seen in human CF patients, especially in gastrointestinal tissue. However, alterations in airway ion transport, which lead to the devastating lung disease in CF patients, appear to be largely absent in the CF mouse models. Reasons for these unexpected findings are discussed. This paper also reviews pharmacotherapeutic and gene therapeutic studies in the various mouse models. PMID:9922382

  11. Targeted gene therapy for the treatment of heart failure.

    PubMed

    Rapti, Kleopatra; Chaanine, Antoine H; Hajjar, Roger J

    2011-01-01

    Chronic heart failure is one of the leading causes of morbidity and mortality in Western countries and is a major financial burden to the health care system. Pharmacologic treatment and implanting devices are the predominant therapeutic approaches. They improve survival and have offered significant improvement in patient quality of life, but they fall short of producing an authentic remedy. Cardiac gene therapy, the introduction of genetic material to the heart, offers great promise in filling this void. In-depth knowledge of the underlying mechanisms of heart failure is, obviously, a prerequisite to achieve this aim. Extensive research in the past decades, supported by numerous methodological breakthroughs, such as transgenic animal model development, has led to a better understanding of the cardiovascular diseases and, inadvertently, to the identification of several candidate genes. Of the genes that can be targeted for gene transfer, calcium cycling proteins are prominent, as abnormalities in calcium handling are key determinants of heart failure. A major impediment, however, has been the development of a safe, yet efficient, delivery system. Nonviral vectors have been used extensively in clinical trials, but they fail to produce significant gene expression. Viral vectors, especially adenoviral, on the other hand, can produce high levels of expression, at the expense of safety. Adeno-associated viral vectors have emerged in recent years as promising myocardial gene delivery vehicles. They can sustain gene expression at a therapeutic level and maintain it over extended periods of time, even for years, and, most important, without a safety risk.

  12. All-optical regulation of gene expression in targeted cells

    NASA Astrophysics Data System (ADS)

    Wang, Yisen; He, Hao; Li, Shiyang; Liu, Dayong; Lan, Bei; Hu, Minglie; Cao, Youjia; Wang, Chingyue

    2014-06-01

    Controllable gene expression is always a challenge and of great significance to biomedical research and clinical applications. Recently, various approaches based on extra-engineered light-sensitive proteins have been developed to provide optogenetic actuators for gene expression. Complicated biomedical techniques including exogenous genes engineering, transfection, and material delivery are needed. Here we present an all-optical method to regulate gene expression in targeted cells. Intrinsic or exogenous genes can be activated by a Ca2+-sensitive transcription factor nuclear factor of activated T cells (NFAT) driven by a short flash of femtosecond-laser irradiation. When applied to mesenchymal stem cells, expression of a differentiation regulator Osterix can be activated by this method to potentially induce differentiation of them. A laser-induced ``Ca2+-comb'' (LiCCo) by multi-time laser exposure is further developed to enhance gene expression efficiency. This noninvasive method hence provides an encouraging advance of gene expression regulation, with promising potential of applying in cell biology and stem-cell science.

  13. Gamma-secretase Inhibitor Prevents Proliferation and Migration of Ductus Arteriosus Smooth Muscle Cells through the Notch3-HES1/2/5 Pathway

    PubMed Central

    Wu, Jiunn-Ren; Yeh, Jwu-Lai; Liou, Shu-Fen; Dai, Zen-Kong; Wu, Bin-Nan; Hsu, Jong-Hau

    2016-01-01

    Patent ductus arteriosus (PDA) can cause morbidity and mortality in neonates. Vascular remodeling, characterized by proliferation and migration of smooth muscle cells (SMCs), is an essential process for postnatal DA closure. Notch signaling is an important mediator of vascular remodelling but its role in DA is unkonwn. We investigated the effects and underlying mechanisms of γ-secretase inhibitor DAPT, a Notch signaling inhibitor on angiotensin II (Ang II)-induced proliferation and migration of DASMCs. Proliferation and migration of DASMCs cultured from neonatal Wistar rats were induced by Ang II, with or without DAPT pre-treatment. In addition, potential underlying mechanisms including cell cycle progression, Ca2+ influx, reactive oxygen species (ROS) production, signal transduction of MAPK and Akt, and Notch receptor with its target gene pathway were examined. We found that DAPT inhibited Ang II-induced DASMCs proliferation and migration dose dependently. DAPT also arrested the cell cycle progression in the G0/G1-phase, and attenuated calcium overload and ROS production caused by Ang II. Moreover, DAPT inhibited nuclear translocation of Notch3 receptor intracellular domain, with decreased expression of its down-stream genes including HES1, HES2 and HES5. Finally, Ang II-activated ERK1/2, JNK and Akt were also counteracted by DAPT. In conclusion, DAPT inhibits Ang II-induced DASMCs proliferation and migration. These effects are potentially mediated by decreased calcium influx, reduced ROS production, and down-regulation of ERK1/2, JNK and Akt, through the Notch3-HES1/2/5 pathway. Therefore, Notch signaling has a role in DA remodeling and may provide a target pathway for therapeutic intervention of PDA. PMID:27570480

  14. Gamma-secretase Inhibitor Prevents Proliferation and Migration of Ductus Arteriosus Smooth Muscle Cells through the Notch3-HES1/2/5 Pathway.

    PubMed

    Wu, Jiunn-Ren; Yeh, Jwu-Lai; Liou, Shu-Fen; Dai, Zen-Kong; Wu, Bin-Nan; Hsu, Jong-Hau

    2016-01-01

    Patent ductus arteriosus (PDA) can cause morbidity and mortality in neonates. Vascular remodeling, characterized by proliferation and migration of smooth muscle cells (SMCs), is an essential process for postnatal DA closure. Notch signaling is an important mediator of vascular remodelling but its role in DA is unkonwn. We investigated the effects and underlying mechanisms of γ-secretase inhibitor DAPT, a Notch signaling inhibitor on angiotensin II (Ang II)-induced proliferation and migration of DASMCs. Proliferation and migration of DASMCs cultured from neonatal Wistar rats were induced by Ang II, with or without DAPT pre-treatment. In addition, potential underlying mechanisms including cell cycle progression, Ca(2+) influx, reactive oxygen species (ROS) production, signal transduction of MAPK and Akt, and Notch receptor with its target gene pathway were examined. We found that DAPT inhibited Ang II-induced DASMCs proliferation and migration dose dependently. DAPT also arrested the cell cycle progression in the G0/G1-phase, and attenuated calcium overload and ROS production caused by Ang II. Moreover, DAPT inhibited nuclear translocation of Notch3 receptor intracellular domain, with decreased expression of its down-stream genes including HES1, HES2 and HES5. Finally, Ang II-activated ERK1/2, JNK and Akt were also counteracted by DAPT. In conclusion, DAPT inhibits Ang II-induced DASMCs proliferation and migration. These effects are potentially mediated by decreased calcium influx, reduced ROS production, and down-regulation of ERK1/2, JNK and Akt, through the Notch3-HES1/2/5 pathway. Therefore, Notch signaling has a role in DA remodeling and may provide a target pathway for therapeutic intervention of PDA. PMID:27570480

  15. Loss of Notch1-dependent p21Waf1/Cip1 expression influences the Notch1 outcome in tumorigenesis

    PubMed Central

    Cialfi, Samantha; Palermo, Rocco; Manca, Sonia; De Blasio, Carlo; Vargas Romero, Paula; Checquolo, Saula; Bellavia, Diana; Uccelletti, Daniela; Saliola, Michele; D'Alessandro, Angelo; Zolla, Lello; Gulino, Alberto; Screpanti, Isabella; Talora, Claudio

    2014-01-01

    Notch signaling plays a complex role in carcinogenesis, and its signaling pathway has both tumor-suppressor and oncogenic components. In this study we investigated the effects of reactive oxygen species (ROS) on Notch1 signaling outcome in keratinocyte biology. We demonstrate that Notch1 function contributes to the arsenic-induced keratinocyte transformation. We found that acute exposure to arsenite increases oxidative stress and inhibits proliferation of keratinocyte cells by upregulation of p21waf1/Cip1. The necessity of p21waf1/Cip1 for arsenite-induced cell death was demonstrated by targeted downregulation of p21waf1/Cip1 by using RNA interference. We further demonstrated that on acute exposure to arsenite, p21waf1/Cip1 is upregulated and Notch1 downmodulated, whereas on chronic exposure to arsenite, malignant progression of arsenite-treated keratinocytes cells was accompanied by regained expression and activity of Notch1. Notch1 activity in arsenite-transformed keratinocytes inhibits arsenite-induced upregulation of p21waf1/Cip1 by sustaining c-myc expression. We further demonstrated that c-myc collaborates with Nrf2, a key regulator for the maintenance of redox homeostasis, to promote metabolic activities that support cell proliferation and cytoprotection. Therefore, Notch1-mediated repression of p21waf1/Cip1 expression results in the inhibition of cell death and keratinocytes transformation. Our results not only demonstrate that sustained Notch1 expression is at least one key event implicated in the arsenite human skin carcinogenic effect, but also may provide mechanistic insights into the molecular aspects that determine whether Notch signaling will be either oncogenic or tumor suppressive. PMID:24801890

  16. Candidate genes and potential targets for therapeutics in Wilms' tumour.

    PubMed

    Blackmore, Christopher; Coppes, Max J; Narendran, Aru

    2010-09-01

    Wilms' tumour (WT) is the most common malignant renal tumour of childhood. During the past two decades or so, molecular studies carried out on biopsy specimens and tumour-derived cell lines have identified a multitude of chromosomal and epigenetic alterations in WT. In addition, a significant amount of evidence has been gathered to identify the genes and signalling pathways that play a defining role in its genesis, growth, survival and treatment responsiveness. As such, these molecules and mechanisms constitute potential targets for novel therapeutic strategies for refractory WT. In this report we aim to review some of the many candidate genes and intersecting pathways that underlie the complexities of WT biology.

  17. Stilbenoids remodel the DNA methylation patterns in breast cancer cells and inhibit oncogenic NOTCH signaling through epigenetic regulation of MAML2 transcriptional activity

    PubMed Central

    Lubecka, Katarzyna; Kurzava, Lucinda; Flower, Kirsty; Buvala, Hannah; Zhang, Hao; Teegarden, Dorothy; Camarillo, Ignacio; Suderman, Matthew; Kuang, Shihuan; Andrisani, Ourania; Flanagan, James M.; Stefanska, Barbara

    2016-01-01

    DNA hypomethylation was previously implicated in cancer progression and metastasis. The purpose of this study was to examine whether stilbenoids, resveratrol and pterostilbene thought to exert anticancer effects, target genes with oncogenic function for de novo methylation and silencing, leading to inactivation of related signaling pathways. Following Illumina 450K, genome-wide DNA methylation analysis reveals that stilbenoids alter DNA methylation patterns in breast cancer cells. On average, 75% of differentially methylated genes have increased methylation, and these genes are enriched for oncogenic functions, including NOTCH signaling pathway. MAML2, a coactivator of NOTCH targets, is methylated at the enhancer region and transcriptionally silenced in response to stilbenoids, possibly explaining the downregulation of NOTCH target genes. The increased DNA methylation at MAML2 enhancer coincides with increased occupancy of repressive histone marks and decrease in activating marks. This condensed chromatin structure is associated with binding of DNMT3B and decreased occupancy of OCT1 transcription factor at MAML2 enhancer, suggesting a role of DNMT3B in increasing methylation of MAML2 after stilbenoid treatment. Our results deliver a novel insight into epigenetic regulation of oncogenic signals in cancer and provide support for epigenetic-targeting strategies as an effective anticancer approach. PMID:27207652

  18. Jagged1-selective notch signaling induces smooth muscle differentiation via a RBP-Jkappa-dependent pathway.

    PubMed

    Doi, Hiroshi; Iso, Tatsuya; Sato, Hiroko; Yamazaki, Miki; Matsui, Hiroki; Tanaka, Toru; Manabe, Ichiro; Arai, Masashi; Nagai, Ryozo; Kurabayashi, Masahiko

    2006-09-29

    The Notch signaling pathway plays a crucial role in specifying cellular fates by interaction between cellular neighbors; however, the molecular mechanism underlying smooth muscle cell (SMC) differentiation by Notch signaling has not been well characterized. Here we demonstrate that Jagged1-Notch signaling promotes SMC differentiation from mesenchymal cells. Overexpression of the Notch intracellular domain, an activated form of Notch, up-regulates the expression of multiple SMC marker genes including SMC-myosin heavy chain (Sm-mhc) in mesenchymal 10T1/2 cells, but not in non-mesenchymal cells. Physiological Notch stimulation by its ligand Jagged1, but not Dll4, directly induces Sm-mhc expression in 10T1/2 cells without de novo protein synthesis, indicative of a ligand-selective effect. Jagged1-induced expression of SM-MHC was blocked bygamma-secretase inhibitor, N-(N-(3,5-difluorophenyl)-l-alanyl)-S-phenylglycine t-butyl ester, which impedes Notch signaling. Using Rbp-jkappa-deficient cells and site-specific mutagenesis of the SM-MHC gene, we show that such an induction is independent of the myocardin-serum response factor-CArG complex, but absolutely dependent on RBP-Jkappa, a major mediator of Notch signaling, and its cognate binding sequence. Of importance, Notch signaling and myocardin synergistically activate SM-MHC gene expression. Taken together, these data suggest that the Jagged1-Notch pathway constitutes an instructive signal for SMC differentiation through an RBP-Jkappa-dependent mechanism and augments gene expression mediated by the myocardin-SRF-CArG complex. Given that Notch pathway components are expressed in vascular SMC during normal development and disease, Notch signaling is likely to play a pivotal role in such situations to modulate the vascular smooth muscle cell phenotype. PMID:16867989

  19. Mechanisms and clinical prospects of Notch inhibitors in the therapy of hematological malignancies

    PubMed Central

    Nefedova, Yulia; Gabrilovich, Dmitry

    2009-01-01

    Activation of Notch signaling has been implicated in pathogenesis of various hematologic tumors including leukemias, lymphomas, and multiple myeloma. Pre-clinical studies have suggested that inhibition of Notch could be an attractive new approach to treatment of hematologic malignancies. This review discusses most recent findings in the field and potential role of Notch signaling as a therapeutic target focusing on the effects of γ-secretase inhibitors. PMID:18951834

  20. Activation of an endothelial Notch1-Jagged1 circuit induces VCAM1 expression, an effect amplified by interleukin-1β.

    PubMed

    Verginelli, Federica; Adesso, Laura; Limon, Isabelle; Alisi, Anna; Gueguen, Marie; Panera, Nadia; Giorda, Ezio; Raimondi, Lavinia; Ciarapica, Roberta; Campese, Antonio F; Screpanti, Isabella; Stifani, Stefano; Kitajewski, Jan; Miele, Lucio; Rota, Rossella; Locatelli, Franco

    2015-12-22

    The Notch1 and Notch4 signaling pathways regulate endothelial cell homeostasis. Inflammatory cytokines induce the expression of endothelial adhesion molecules, including VCAM1, partly by downregulating Notch4 signaling. We investigated the role of endothelial Notch1 in this IL-1β-mediated process. Brief treatment with IL-1β upregulated endothelial VCAM1 and Notch ligand Jagged1. IL-1β decreased Notch1 mRNA levels, but levels of the active Notch1ICD protein remained constant. IL-1β-mediated VCAM1 induction was downregulated in endothelial cells subjected to pretreatment with a pharmacological inhibitor of the γ-secretase, which activates Notch receptors, producing NotchICD. It was also downregulated in cells in which Notch1 and/or Jagged1 were silenced.Conversely, the forced expression of Notch1ICD in naïve endothelial cells upregulated VCAM1 per se and amplified IL-1β-mediated VCAM1 induction. Jagged1 levels increased and Notch4 signaling was downregulated in parallel. Finally, Notch1ICD and Jagged1 expression was upregulated in the endothelium of the liver in a model of chronic liver inflammation.In conclusion, we describe here a cell-autonomous, pro-inflammatory endothelial Notch1-Jagged1 circuit (i) triggering the expression of VCAM1 even in the absence of inflammatory cytokines and (ii) enhancing the effects of IL-1β. Thus, IL-1β regulates Notch1 and Notch4 activity in opposite directions, consistent with a selective targeting of Notch1 in inflamed endothelium.

  1. Activation of an endothelial Notch1-Jagged1 circuit induces VCAM1 expression, an effect amplified by interleukin-1β.

    PubMed

    Verginelli, Federica; Adesso, Laura; Limon, Isabelle; Alisi, Anna; Gueguen, Marie; Panera, Nadia; Giorda, Ezio; Raimondi, Lavinia; Ciarapica, Roberta; Campese, Antonio F; Screpanti, Isabella; Stifani, Stefano; Kitajewski, Jan; Miele, Lucio; Rota, Rossella; Locatelli, Franco

    2015-12-22

    The Notch1 and Notch4 signaling pathways regulate endothelial cell homeostasis. Inflammatory cytokines induce the expression of endothelial adhesion molecules, including VCAM1, partly by downregulating Notch4 signaling. We investigated the role of endothelial Notch1 in this IL-1β-mediated process. Brief treatment with IL-1β upregulated endothelial VCAM1 and Notch ligand Jagged1. IL-1β decreased Notch1 mRNA levels, but levels of the active Notch1ICD protein remained constant. IL-1β-mediated VCAM1 induction was downregulated in endothelial cells subjected to pretreatment with a pharmacological inhibitor of the γ-secretase, which activates Notch receptors, producing NotchICD. It was also downregulated in cells in which Notch1 and/or Jagged1 were silenced.Conversely, the forced expression of Notch1ICD in naïve endothelial cells upregulated VCAM1 per se and amplified IL-1β-mediated VCAM1 induction. Jagged1 levels increased and Notch4 signaling was downregulated in parallel. Finally, Notch1ICD and Jagged1 expression was upregulated in the endothelium of the liver in a model of chronic liver inflammation.In conclusion, we describe here a cell-autonomous, pro-inflammatory endothelial Notch1-Jagged1 circuit (i) triggering the expression of VCAM1 even in the absence of inflammatory cytokines and (ii) enhancing the effects of IL-1β. Thus, IL-1β regulates Notch1 and Notch4 activity in opposite directions, consistent with a selective targeting of Notch1 in inflamed endothelium. PMID:26646450

  2. Bioengineered Silk Gene Delivery System for Nuclear Targeting

    PubMed Central

    Yigit, Sezin; Tokareva, Olena; Varone, Antonio; Georgakoudi, Irene

    2015-01-01

    Gene delivery research has gained momentum with the use of lipophilic vectors that mimic viral systems to increase transfection efficiency. However, maintaining cell viability with these systems remains a major challenge. Therefore biocompatible and nontoxic biopolymers that are designed by combining non-immunological viral mimicking components with suitable carriers have been explored to address these limitations. In the present study recombinant DNA technology was used to design a multi-functional gene delivery system for nuclear targeting, while also supporting cell viability. Spider dragline silk recombinant proteins were modified with DNA condensing units and the proton sponge endosomal escape pathway was utilized for enhanced delivery. Short-term transfection efficiency in a COS-7 cell line (adherent kidney cells isolated from African green monkey) was enhanced compared to lipofectamine and polyethyleneimine (PEI), as was cell viability with these recombinant bio-polyplexes. Endosomal escape and consequent nuclear targeting were shown with fluorescence microscopy. PMID:24889658

  3. Bortezomib enhances expression of effector molecules in anti-tumor CD8+ T lymphocytes by promoting Notch-nuclear factor-κB crosstalk

    PubMed Central

    Thounaojam, Menaka C.; Dudimah, Duafalia F.; Pellom, Samuel T.; Uzhachenko, Roman V.; Carbone, David P.; Dikov, Mikhail M.; Shanker, Anil

    2015-01-01

    The immunosuppressive tumor microenvironment usurps host antitumor immunity by multiple mechanisms including interference with the Notch system, which is important for various metazoan cell fate decisions and hematopoietic cell differentiation and function. We observed that treatment with the proteasome inhibitor bortezomib in mice bearing various solid tumors resulted in an upregulated expression of various Notch signaling components in lymphoid tissues, thereby increasing CD8+T-lymphocyte IFNγ secretion and expression of effector molecules, perforin and granzyme B, as well as the T-box transcription factor eomesodermin. Bortezomib also neutralized TGFβ-mediated suppression of IFNγ and granzyme B expression in activated CD8+T-cells. Of note, bortezomib reversed tumor-induced downregulation of Notch receptors, Notch1 and Notch2, as well as increased the levels of cleaved Notch intracellular domain (NICD) and downstream targets Hes1 and Hey1 in tumor-draining CD8+T-cells. Moreover, bortezomib promoted CD8+T-cell nuclear factor-κB (NFκB) activity by increasing the total and phosphorylated levels of the IκB kinase and IκBα as well as the cytoplasmic and nuclear levels of phosphorylated p65. Even when we blocked NFκB activity by Bay-11-7082, or NICD cleavage by γ-secretase inhibitor, bortezomib significantly increased expression of Notch Hes1 and Hey1 genes as well as perforin, granzyme B and eomesodermin in activated CD8+T-cells. Data suggest that bortezomib can rescue tumor-induced dysfunction of CD8+T-cells by its intrinsic stimulatory effects promoting NICD-NFκB crosstalk. These findings provide novel insights on using bortezomib not only as an agent to sensitize tumors to cell death but also to provide lymphocyte-stimulatory effects, thereby overcoming immunosuppressive actions of tumor on anti-tumor T-cell functions. PMID:26431276

  4. Bortezomib enhances expression of effector molecules in anti-tumor CD8+ T lymphocytes by promoting Notch-nuclear factor-κB crosstalk.

    PubMed

    Thounaojam, Menaka C; Dudimah, Duafalia F; Pellom, Samuel T; Uzhachenko, Roman V; Carbone, David P; Dikov, Mikhail M; Shanker, Anil

    2015-10-20

    The immunosuppressive tumor microenvironment usurps host antitumor immunity by multiple mechanisms including interference with the Notch system, which is important for various metazoan cell fate decisions and hematopoietic cell differentiation and function. We observed that treatment with the proteasome inhibitor bortezomib in mice bearing various solid tumors resulted in an upregulated expression of various Notch signaling components in lymphoid tissues, thereby increasing CD8+T-lymphocyte IFNγ secretion and expression of effector molecules, perforin and granzyme B, as well as the T-box transcription factor eomesodermin. Bortezomib also neutralized TGFβ-mediated suppression of IFNγ and granzyme B expression in activated CD8+T-cells. Of note, bortezomib reversed tumor-induced downregulation of Notch receptors, Notch1 and Notch2, as well as increased the levels of cleaved Notch intracellular domain (NICD) and downstream targets Hes1 and Hey1 in tumor-draining CD8+T-cells. Moreover, bortezomib promoted CD8+T-cell nuclear factor-κB (NFκB) activity by increasing the total and phosphorylated levels of the IκB kinase and IκBα as well as the cytoplasmic and nuclear levels of phosphorylated p65. Even when we blocked NFκB activity by Bay-11-7082, or NICD cleavage by γ-secretase inhibitor, bortezomib significantly increased expression of Notch Hes1 and Hey1 genes as well as perforin, granzyme B and eomesodermin in activated CD8+T-cells. Data suggest that bortezomib can rescue tumor-induced dysfunction of CD8+T-cells by its intrinsic stimulatory effects promoting NICD-NFκB crosstalk. These findings provide novel insights on using bortezomib not only as an agent to sensitize tumors to cell death but also to provide lymphocyte-stimulatory effects, thereby overcoming immunosuppressive actions of tumor on anti-tumor T-cell functions.

  5. Identification of key target genes and pathways in laryngeal carcinoma

    PubMed Central

    Liu, Feng; Du, Jintao; Liu, Jun; Wen, Bei

    2016-01-01

    The purpose of the present study was to screen the key genes associated with laryngeal carcinoma and to investigate the molecular mechanism of laryngeal carcinoma progression. The gene expression profile of GSE10935 [Gene Expression Omnibus (GEO) accession number], including 12 specimens from laryngeal papillomas and 12 specimens from normal laryngeal epithelia controls, was downloaded from the GEO database. Differentially expressed genes (DEGs) were screened in laryngeal papillomas compared with normal controls using Limma package in R language, followed by Gene Ontology (GO) enrichment analysis and pathway enrichment analysis. Furthermore, the protein-protein interaction (PPI) network of DEGs was constructed using Cytoscape software and modules were analyzed using MCODE plugin from the PPI network. Furthermore, significant biological pathway regions (sub-pathway) were identified by using iSubpathwayMiner analysis. A total of 67 DEGs were identified, including 27 up-regulated genes and 40 down-regulated genes and they were involved in different GO terms and pathways. PPI network analysis revealed that Ras association (RalGDS/AF-6) domain family member 1 (RASSF1) was a hub protein. The sub-pathway analysis identified 9 significantly enriched sub-pathways, including glycolysis/gluconeogenesis and nitrogen metabolism. Genes such as phosphoglycerate kinase 1 (PGK1), carbonic anhydrase II (CA2), and carbonic anhydrase XII (CA12) whose node degrees were >10 were identified in the disease risk sub-pathway. Genes in the sub-pathway, such as RASSF1, PGK1, CA2 and CA12 were presumed to serve critical roles in laryngeal carcinoma. The present study identified DEGs and their sub-pathways in the disease, which may serve as potential targets for treatment of laryngeal carcinoma. PMID:27446427

  6. Modification of the apolipoprotein B gene in HepG2 cells by gene targeting.

    PubMed Central

    Farese, R V; Flynn, L M; Young, S G

    1992-01-01

    The HepG2 cell line has been used extensively to study the synthesis and secretion of apolipoprotein (apo) B. In this study, we tested whether gene-targeting techniques can be used to inactivate one of the apo B alleles in HepG2 cells by homologous recombination using a transfected gene-targeting vector. Our vector contained exons 1-7 of the apo B gene, in which exon 2 was interrupted by a promoterless neomycin resistance (neo(r)) gene. The recombination of this vector with the cognate gene would inactivate an apo B allele and enable the apo B promoter to activate the transcription of the neo(r) gene. To detect the rare homologous recombinant clone, we developed a novel solid phase RIA that uses the apo B-specific monoclonal antibody MB19 to analyze the apo B secreted by G418-resistant (G418r) clones. Antibody MB19 detects a two-allele genetic polymorphism in apo B by binding to the apo B allotypes MB19(1) and MB19(2) with high and low affinity, respectively. HepG2 cells normally secrete both the apo B MB19 allotypes. Using the MB19 immunoassay, we identified a G418r HepG2 clone that had lost the ability to secrete the MB19(1) allotype. The inactivation of an apo B allele of this clone was confirmed by the polymerase chain reaction amplification of an 865-bp fragment unique to the targeted apo B allele and by Southern blotting of genomic DNA. This study demonstrates that gene-targeting techniques can be used to modify the apo B gene in HepG2 cells and demonstrates the usefulness of a novel solid phase RIA system for detecting apo B gene targeting events in this cell line. Images PMID:1321843

  7. Inferring gene targets of drugs and chemical compounds from gene expression profiles

    PubMed Central

    Noh, Heeju; Gunawan, Rudiyanto

    2016-01-01

    Motivation: Finding genes which are directly perturbed or targeted by drugs is of great interest and importance in drug discovery. Several network filtering methods have been created to predict the gene targets of drugs from gene expression data based on an ordinary differential equation model of the gene regulatory network (GRN). A critical step in these methods involves inferring the GRN from the expression data, which is a very challenging problem on its own. In addition, existing network filtering methods require computationally intensive parameter tuning or expression data from experiments with known genetic perturbations or both. Results: We developed a method called DeltaNet for the identification of drug targets from gene expression data. Here, the gene target predictions were directly inferred from the data without a separate step of GRN inference. DeltaNet formulation led to solving an underdetermined linear regression problem, for which we employed least angle regression (DeltaNet-LAR) or LASSO regularization (DeltaNet-LASSO). The predictions using DeltaNet for expression data of Escherichia coli, yeast, fruit fly and human were significantly more accurate than those using network filtering methods, namely mode of action by network identification (MNI) and sparse simultaneous equation model (SSEM). Furthermore, DeltaNet using LAR did not require any parameter tuning and could provide computational speed-up over existing methods. Conclusion: DeltaNet is a robust and numerically efficient tool for identifying gene perturbations from gene expression data. Importantly, the method requires little to no expert supervision, while providing accurate gene target predictions. Availability and implementation: DeltaNet is available on http://www.cabsel.ethz.ch/tools/DeltaNet. Contact: rudi.gunawan@chem.ethz.ch Supplementary information: Supplementary data are available at Bioinformatics online. PMID:27153589

  8. Early-phase GVHD gene expression profile in target versus non-target tissues: kidney, a possible target?

    PubMed

    Sadeghi, B; Al-Chaqmaqchi, H; Al-Hashmi, S; Brodin, D; Hassan, Z; Abedi-Valugerdi, M; Moshfegh, A; Hassan, M

    2013-02-01

    GVHD is a major complication after allo-SCT. In GVHD, some tissues like liver, intestine and skin are infiltrated by donor T cells while others like muscle are not. The mechanism underlying targeted tropism of donor T cells is not fully understood. In the present study, we aim to explore differences in gene expression profile among target versus non-target tissues in a mouse model of GVHD based on chemotherapy conditioning. Expression levels of JAK-signal transducers and activators of transcription (STAT), CXCL1, ICAM1 and STAT3 were increased in the liver and remained unchanged (or decreased) in the muscle and kidney after conditioning. At the start of GVHD the expression levels of CXCL9, ITGb2, SAA3, MARCO, TLR and VCAM1 were significantly higher in the liver or kidney compared with the muscle of GVHD animals. Moreover, biological processes of inflammatory reactions, leukocyte migration, response to bacterium and chemotaxis followed the same pattern. Our data show that both chemotherapy and allogenicity exclusively induce expression of inflammatory genes in target tissues. Moreover, gene expression profile and histopathological findings in the kidney are similar to those observed in the liver of GVHD mice.

  9. Targeted disruption of the Lowe syndrome gene (OCRL-1)

    SciTech Connect

    Jaenne, P.A.; Olivos, I.; Grinberg, A.

    1994-09-01

    The oculocerebrorenal syndrome of Lowe (OCRL) is a rare X-linked disease characterized by congenital cataract formation, mental retardation and renal tubular dysfunction (Fanconi syndrome). The gene for OCRL (OCRL-1) has recently been identified through positional cloning techniques and is highly homologous to a previously reported gene encoding a 75 kDa inositol polyphosphate-5-phosphatase. Thus OCRL might be caused by an alteration in inositol metabolism. In order to further investigate the role of OCRL-1 in Lowe`s syndrome, we decided to use targeted disruption to create mice lacking a functional OCRL-1 protein. The murine homologue of OCRL-1 (Ocrl-1) was cloned from a 129Sv genomic library. Two targeting vectors were created from the 3{prime}-end of the gene by fusing a neomycin resistance gene (PGK-Neo) into two exons. The first vector employed a classic positive negative selection scheme whereas the second vector included a polyadenylation trap. The vectors were electroporated into CCE or J1 ES cells and recombinants were screened by Southern blotting. Targeted cells were obtained at a frequency of 1/50 (for CCE) and 1/16 (for J1 using the polyadenylation trap). Using antibodies made to an OCRL-1 fusion protein, we could demonstrate a lack of Ocrl-1 protein product in the targeted ES cell lines. Therefore, we had created a null allele at the Ocrl-1 locus. The targeted ES clones were injected into 3.5 dpc C57B1/6 blastocysts and chimeric mice were obtained. Male chimeras have been made from five targeted cell lines. The males were mated with C57B1/6 females and germline transmission has been obtained from males derived from two of the five cell lines (one from CCE and one from J1 targeted ES cells). Preliminary analysis of male Ocrl-1{sup {minus}} mice suggests the presence of a proximal renal tubular dysfunction but the absence of detectable cataracts. We are presently continuing our phenotypic analyses.

  10. Treating psoriasis by targeting its susceptibility gene Rel.

    PubMed

    Fan, Tingting; Wang, Shaowen; Yu, Linjiang; Yi, Huqiang; Liu, Ruiling; Geng, Wenwen; Wan, Xiaochun; Ma, Yifan; Cai, Lintao; Chen, Youhai H; Ruan, Qingguo

    2016-04-01

    Psoriasis is a chronic inflammatory disorder of the skin. Accumulating evidence indicates that the Rel gene, a member of the NF-κB family, is a risk factor for the disease. We sought to investigate whether psoriasis can be prevented by directly targeting the Rel gene transcript, i.e., the c-Rel mRNA. Using chemically-modified c-Rel specific siRNA (siRel) and poly(ethylene glycol)-b-poly(l-lysine)-b-poly(l-leucine) (PEG-PLL-PLLeu) micelles, we successfully knocked down the expression of c-Rel, and showed that the expression of cytokine IL-23, a direct target of c-Rel that can drive the development of IL-17-producing T cells, was markedly inhibited. More importantly, treating mice with siRel not only prevented but also ameliorated imiquimod (IMQ)-induced psoriasis. Mechanistic studies showed that siRel treatment down-regulated the expression of multiple inflammatory cytokines. Taken together, these results indicate that the susceptibility gene Rel can be targeted to treat and prevent psoriasis.

  11. Treating psoriasis by targeting its susceptibility gene Rel.

    PubMed

    Fan, Tingting; Wang, Shaowen; Yu, Linjiang; Yi, Huqiang; Liu, Ruiling; Geng, Wenwen; Wan, Xiaochun; Ma, Yifan; Cai, Lintao; Chen, Youhai H; Ruan, Qingguo

    2016-04-01

    Psoriasis is a chronic inflammatory disorder of the skin. Accumulating evidence indicates that the Rel gene, a member of the NF-κB family, is a risk factor for the disease. We sought to investigate whether psoriasis can be prevented by directly targeting the Rel gene transcript, i.e., the c-Rel mRNA. Using chemically-modified c-Rel specific siRNA (siRel) and poly(ethylene glycol)-b-poly(l-lysine)-b-poly(l-leucine) (PEG-PLL-PLLeu) micelles, we successfully knocked down the expression of c-Rel, and showed that the expression of cytokine IL-23, a direct target of c-Rel that can drive the development of IL-17-producing T cells, was markedly inhibited. More importantly, treating mice with siRel not only prevented but also ameliorated imiquimod (IMQ)-induced psoriasis. Mechanistic studies showed that siRel treatment down-regulated the expression of multiple inflammatory cytokines. Taken together, these results indicate that the susceptibility gene Rel can be targeted to treat and prevent psoriasis. PMID:26993753

  12. Notch Signaling in Neuroendocrine Tumors

    PubMed Central

    Crabtree, Judy S.; Singleton, Ciera S.; Miele, Lucio

    2016-01-01

    Carcinoids and neuroendocrine tumors (NETs) are a heterogeneous group of tumors that arise from the neuroendocrine cells of the GI tract, endocrine pancreas, and the respiratory system. NETs remain significantly understudied with respect to molecular mechanisms of pathogenesis, particularly the role of cell fate signaling systems such as Notch. The abundance of literature on the Notch pathway is a testament to its complexity in different cellular environments. Notch receptors can function as oncogenes in some contexts and tumor suppressors in others. The genetic heterogeneity of NETs suggests that to fully understand the roles and the potential therapeutic implications of Notch signaling in NETs, a comprehensive analysis of Notch expression patterns and potential roles across all NET subtypes is required. PMID:27148486

  13. Nanoparticle optical notch filters

    NASA Astrophysics Data System (ADS)

    Kasinadhuni, Pradeep Kumar

    Developing novel light blocking products involves the design of a nanoparticle optical notch filter, working on the principle of localized surface plasmon resonance (LSPR). These light blocking products can be used in many applications. One such application is to naturally reduce migraine headaches and light sensitivity. Melanopsin ganglion cells present in the retina of the human eye, connect to the suprachiasmatic nucleus (SCN-the body's clock) in the brain, where they participate in the entrainment of the circadian rhythms. As the Melanopsin ganglion cells are involved in triggering the migraine headaches in photophobic patients, it is necessary to block the part of visible spectrum that activates these cells. It is observed from the action potential spectrum of the ganglion cells that they absorb light ranging from 450-500nm (blue-green part) of the visible spectrum with a λmax (peak sensitivity) of around 480nm (blue line). Currently prescribed for migraine patients is the FL-41 coating, which blocks a broad range of wavelengths, including wavelengths associated with melanopsin absorption. The nanoparticle optical notch filter is designed to block light only at 480nm, hence offering an effective prescription for the treatment of migraine headaches.

  14. Liver-targeted gene therapy: Approaches and challenges.

    PubMed

    Aravalli, Rajagopal N; Belcher, John D; Steer, Clifford J

    2015-06-01

    The liver plays a major role in many inherited and acquired genetic disorders. It is also the site for the treatment of certain inborn errors of metabolism that do not directly cause injury to the liver. The advancement of nucleic acid-based therapies for liver maladies has been severely limited because of the myriad untoward side effects and methodological limitations. To address these issues, research efforts in recent years have been intensified toward the development of targeted gene approaches using novel genetic tools, such as zinc-finger nucleases, transcription activator-like effector nucleases, and clustered regularly interspaced short palindromic repeats as well as various nonviral vectors such as Sleeping Beauty transposons, PiggyBac transposons, and PhiC31 integrase. Although each of these methods uses a distinct mechanism of gene modification, all of them are dependent on the efficient delivery of DNA and RNA molecules into the cell. This review provides an overview of current and emerging therapeutic strategies for liver-targeted gene therapy and gene repair.

  15. Survivin, a Promising Gene for Targeted Cancer Treatment.

    PubMed

    Shamsabadi, Fatemeh T; Eidgahi, Mohammad Reza Akbari; Mehrbod, Parvaneh; Daneshvar, Nasibeh; Allaudin, Zeenathul Nazariah; Yamchi, Ahad; Shahbazi, Majid

    2016-01-01

    Drawbacks of conventional cancer treatments, with lack of specificity and cytotoxicity using current approaches, underlies the necessity for development of a novel approach, gene-directed cancer therapy. This has provided novel technological opportunities in vitro and in vivo. This review focuses on a member of an apoptosis inhibitor family, survivin, as a valuable target. Not only the gene but also its promoter are applicable in this context. This article is based on a literature survey, with especial attention to RNA interference as well as tumor- specific promoter action. The search engine and databases utilized were Science direct, PubMed, MEDLINE and Google. In addition to cell-cycle modulation, apoptosis inhibition, interaction in cell-signaling pathways, cancer-selective expression, survivin also may be considered as specific target through its promoter as a novel treatment for cancer. Our purpose in writing this article was to create awareness in researchers, emphasizing relation of survivin gene expression to potential cancer treatment. The principal result and major conclusion of this manuscript are that survivin structure, biological functions and applications of RNA interference systems as well as tumor-specific promoter activity are of major interest for cancer gene therapy. PMID:27644605

  16. Tumor targeting and microenvironment-responsive nanoparticles for gene delivery.

    PubMed

    Huang, Shixian; Shao, Kun; Kuang, Yuyang; Liu, Yang; Li, Jianfeng; An, Sai; Guo, Yubo; Ma, Haojun; He, Xi; Jiang, Chen

    2013-07-01

    A tumor targeting nanoparticle system has been successfully developed to response to the lowered tumor extracellular pH (pHe) and upregulated matrix metalloproteinase 2 (MMP2) in the tumor microenvironment. The nanoparticles are modified with activatable cell-penetrating peptide (designated as dtACPP) that's dual-triggered by the lowered pHe and MMP2. In dtACPP, the internalization function of cell-penetrating peptide (CPP) is quenched by a pH-sensitive masking peptide, linking by a MMP2 substrate. The masking peptide is negatively charged to quench the cationic CPP well after systemic administration. Hence, dtACPP-modified nanoparticles possesses passive tumor targetability via the enhanced permeability and retention (EPR) effect. Once reaching the tumor microenvironment, the pre-existing attraction would be eliminated due to the lowered pHe, accompanying the linker cleaved by MMP2, dtACPP would be activated to expose CPP to drive the nanoparticles' internalization into the intratumoral cells. The studies of plasmid DNA loading, toxicity assessment, cellular uptake, tumor targeting delivery, and gene transfection demonstrate that dtACPP-modified nanoparticle system is a potential candidate for tumor targeting gene delivery.

  17. Targeted resequencing of candidate genes using selector probes

    PubMed Central

    Johansson, H.; Isaksson, M.; Sörqvist, E. Falk; Roos, F.; Stenberg, J.; Sjöblom, T.; Botling, J.; Micke, P.; Edlund, K.; Fredriksson, S.; Kultima, H. Göransson; Ericsson, Olle; Nilsson, Mats

    2011-01-01

    Targeted genome enrichment is a powerful tool for making use of the massive throughput of novel DNA-sequencing instruments. We herein present a simple and scalable protocol for multiplex amplification of target regions based on the Selector technique. The updated version exhibits improved coverage and compatibility with next-generation-sequencing (NGS) library-construction procedures for shotgun sequencing with NGS platforms. To demonstrate the performance of the technique, all 501 exons from 28 genes frequently involved in cancer were enriched for and sequenced in specimens derived from cell lines and tumor biopsies. DNA from both fresh frozen and formalin-fixed paraffin-embedded biopsies were analyzed and 94% specificity and 98% coverage of the targeted region was achieved. Reproducibility between replicates was high (R2 = 0, 98) and readily enabled detection of copy-number variations. The procedure can be carried out in <24 h and does not require any dedicated instrumentation. PMID:21059679

  18. Identification of gene targets against dormant phase Mycobacterium tuberculosis infections

    PubMed Central

    Murphy, Dennis J; Brown, James R

    2007-01-01

    Background Mycobacterium tuberculosis, the causative agent of tuberculosis (TB), infects approximately 2 billion people worldwide and is the leading cause of mortality due to infectious disease. Current TB therapy involves a regimen of four antibiotics taken over a six month period. Patient compliance, cost of drugs and increasing incidence of drug resistant M. tuberculosis strains have added urgency to the development of novel TB therapies. Eradication of TB is affected by the ability of the bacterium to survive up to decades in a dormant state primarily in hypoxic granulomas in the lung and to cause recurrent infections. Methods The availability of M. tuberculosis genome-wide DNA microarrays has lead to the publication of several gene expression studies under simulated dormancy conditions. However, no single model best replicates the conditions of human pathogenicity. In order to identify novel TB drug targets, we performed a meta-analysis of multiple published datasets from gene expression DNA microarray experiments that modeled infection leading to and including the dormant state, along with data from genome-wide insertional mutagenesis that examined gene essentiality. Results Based on the analysis of these data sets following normalization, several genome wide trends were identified and used to guide the selection of targets for therapeutic development. The trends included the significant up-regulation of genes controlled by devR, down-regulation of protein and ATP synthesis, and the adaptation of two-carbon metabolism to the hypoxic and nutrient limited environment of the granuloma. Promising targets for drug discovery were several regulatory elements (devR/devS, relA, mprAB), enzymes involved in redox balance and respiration, sulfur transport and fixation, pantothenate, isoprene, and NAD biosynthesis. The advantages and liabilities of each target are discussed in the context of enzymology, bacterial pathways, target tractability, and drug development

  19. MicroRNAs and Their Target Genes in Gingival Tissues

    PubMed Central

    Stoecklin-Wasmer, C.; Guarnieri, P.; Celenti, R.; Demmer, R.T.; Kebschull, M.; Papapanou, P.N.

    2012-01-01

    To gain insights into the in vivo function of miRNAs in the context of periodontitis, we examined the occurrence of miRNAs in healthy and diseased gingival tissues and validated their in silico-predicted targets through mRNA profiling using whole-genome microarrays in the same specimens. Eighty-six individuals with periodontitis contributed 198 gingival papillae: 158 ‘diseased’ (bleeding-on-probing, PD > 4 mm, and AL ≥ 3 mm) and 40 ‘healthy’ (no bleeding, PD ≤ 4 mm, and AL ≤ 2 mm). Expression of 1,205 miRNAs was assessed by microarrays, followed by selected confirmation by quantitative RT-PCR. Predicted miRNA targets were identified and tested for enrichment by Gene Set Enrichment Analysis (GSEA). Enriched gene sets were grouped in functional categories by DAVID and Ingenuity Pathway Analysis. One hundred fifty-nine miRNAs were significantly differentially expressed between healthy and diseased gingiva. Four miRNAs (hsa-miR-451, hsa-miR-223, hsa-miR-486-5p, hsa-miR-3917) were significantly overexpressed, and 7 (hsa-miR-1246, hsa-miR-1260, hsa-miR-141, hsa-miR-1260b, hsa-miR-203, hsa-miR-210, hsa-miR-205*) were underexpressed by > 2-fold in diseased vs. healthy gingiva. GSEA and additional filtering identified 60 enriched miRNA gene sets with target genes involved in immune/inflammatory responses and tissue homeostasis. This is the first study that concurrently examined miRNA and mRNA expression in gingival tissues and will inform mechanistic experimentation to dissect the role of miRNAs in periodontal tissue homeostasis and pathology. PMID:22879578

  20. Radiation-Induced Notch Signaling in Breast Cancer Stem Cells

    SciTech Connect

    Lagadec, Chann; Vlashi, Erina; Alhiyari, Yazeed; Phillips, Tiffany M.; Bochkur Dratver, Milana; Pajonk, Frank

    2013-11-01

    Purpose: To explore patterns of Notch receptor and ligand expression in response to radiation that could be crucial in defining optimal dosing schemes for γ-secretase inhibitors if combined with radiation. Methods and Materials: Using MCF-7 and T47D breast cancer cell lines, we used real-time reverse transcription–polymerase chain reaction to study the Notch pathway in response to radiation. Results: We show that Notch receptor and ligand expression during the first 48 hours after irradiation followed a complex radiation dose–dependent pattern and was most pronounced in mammospheres, enriched for breast cancer stem cells. Additionally, radiation activated the Notch pathway. Treatment with a γ-secretase inhibitor prevented radiation-induced Notch family gene expression and led to a significant reduction in the size of the breast cancer stem cell pool. Conclusions: Our results indicate that, if combined with radiation, γ-secretase inhibitors may prevent up-regulation of Notch receptor and ligand family members and thus reduce the number of surviving breast cancer stem cells.

  1. Embryonic arrest at midgestation and disruption of Notch signaling produced by the absence of both epsin 1 and epsin 2 in mice

    PubMed Central

    Chen, Hong; Ko, Genevieve; Zatti, Alessandra; Di Giacomo, Giuseppina; Liu, Lijuan; Raiteri, Elisabetta; Perucco, Ezio; Collesi, Chiara; Min, Wang; Zeiss, Caroline; De Camilli, Pietro; Cremona, Ottavio

    2009-01-01

    Epsins are endocytic adaptors with putative functions in general aspects of clathrin-mediated endocytosis as well as in the internalization of specific membrane proteins. We have now tested the role of the ubiquitously expressed epsin genes, Epn1 and Epn2, by a genetic approach in mice. While either gene is dispensable for life, their combined inactivation results in embryonic lethality at E9.5–E10, i.e., at the beginning of organogenesis. Consistent with studies in Drosophila, where epsin endocytic function was linked to Notch activation, developmental defects observed in epsin 1/2 double knockout (DKO) embryos recapitulated those produced by a global impairment of Notch signaling. Accordingly, expression of Notch primary target genes was severely reduced in DKO embryos. However, housekeeping forms of clathrin-mediated endocytosis were not impaired in cells derived from these embryos. These findings support a role of epsin as a specialized endocytic adaptor, with a critical role in the activation of Notch signaling in mammals. PMID:19666558

  2. NOTCH signaling in skeletal progenitors is critical for fracture repair

    PubMed Central

    Wang, Cuicui; Inzana, Jason A.; Mirando, Anthony J.; Liu, Zhaoyang; Shen, Jie; O’Keefe, Regis J.; Awad, Hani A.; Hilton, Matthew J.

    2016-01-01

    Fracture nonunions develop in 10%–20% of patients with fractures, resulting in prolonged disability. Current data suggest that bone union during fracture repair is achieved via proliferation and differentiation of skeletal progenitors within periosteal and soft tissues surrounding bone, while bone marrow stromal/stem cells (BMSCs) and other skeletal progenitors may also contribute. The NOTCH signaling pathway is a critical maintenance factor for BMSCs during skeletal development, although the precise role for NOTCH and the requisite nature of BMSCs following fracture is unknown. Here, we evaluated whether NOTCH and/or BMSCs are required for fracture repair by performing nonstabilized and stabilized fractures on NOTCH-deficient mice with targeted deletion of RBPjk in skeletal progenitors, maturing osteoblasts, and committed chondrocytes. We determined that removal of NOTCH signaling in BMSCs and subsequent depletion of this population result in fracture nonunion, as the fracture repair process was normal in animals harboring either osteoblast- or chondrocyte-specific deletion of RBPjk. Together, this work provides a genetic model of a fracture nonunion and demonstrates the requirement for NOTCH and BMSCs in fracture repair, irrespective of fracture stability and vascularity. PMID:26950423

  3. Notch1 signaling stimulates proliferation of immature cardiomyocytes.

    PubMed

    Collesi, Chiara; Zentilin, Lorena; Sinagra, Gianfranco; Giacca, Mauro

    2008-10-01

    The identification of the molecular mechanisms controlling cardiomyocyte proliferation during the embryonic, fetal, and early neonatal life appears of paramount interest in regard to exploiting this information to promote cardiac regeneration. Here, we show that the proliferative potential of neonatal rat cardiomyocytes is powerfully stimulated by the sustained activation of the Notch pathway. We found that Notch1 is expressed in proliferating ventricular immature cardiac myocytes (ICMs) both in vitro and in vivo, and that the number of Notch1-positive cells in the heart declines with age. Notch1 expression in ICMs paralleled the expression of its Jagged1 ligand on non-myocyte supporting cells. The inhibition of Notch signaling in ICMs blocked their proliferation and induced apoptosis; in contrast, its activation by Jagged1 or by the constitutive expression of its activated form using an adeno-associated virus markedly stimulated proliferative signaling and promoted ICM expansion. Maintenance or reactivation of Notch signaling in cardiac myocytes might represent an interesting target for innovative regenerative therapy. PMID:18824567

  4. Hierarchy of Notch-Delta interactions promoting T cell lineage commitment and maturation.

    PubMed

    Besseyrias, Valerie; Fiorini, Emma; Strobl, Lothar J; Zimber-Strobl, Ursula; Dumortier, Alexis; Koch, Ute; Arcangeli, Marie-Laure; Ezine, Sophie; Macdonald, H Robson; Radtke, Freddy

    2007-02-19

    Notch1 (N1) receptor signaling is essential and sufficient for T cell development, and recently developed in vitro culture systems point to members of the Delta family as being the physiological N1 ligands. We explored the ability of Delta1 (DL1) and DL4 to induce T cell lineage commitment and/or maturation in vitro and in vivo from bone marrow (BM) precursors conditionally gene targeted for N1 and/or N2. In vitro DL1 can trigger T cell lineage commitment via either N1 or N2. N1- or N2-mediated T cell lineage commitment can also occur in the spleen after short-term BM transplantation. However, N2-DL1-mediated signaling does not allow further T cell maturation beyond the CD25(+) stage due to a lack of T cell receptor beta expression. In contrast to DL1, DL4 induces and supports T cell commitment and maturation in vitro and in vivo exclusively via specific interaction with N1. Moreover, comparative binding studies show preferential interaction of DL4 with N1, whereas binding of DL1 to N1 is weak. Interestingly, preferential N1-DL4 binding reflects reduced dependence of this interaction on Lunatic fringe, a glycosyl transferase that generally enhances the avidity of Notch receptors for Delta ligands. Collectively, our results establish a hierarchy of Notch-Delta interactions in which N1-DL4 exhibits the greatest capacity to induce and support T cell development.

  5. Gliolectin positively regulates Notch signalling during wing-vein specification in Drosophila.

    PubMed

    Prasad, Naveen; Shashidhara, Lingadahalli S

    2015-01-01

    Notch signalling is essential for animal development. It integrates multiple pathways controlling cell fate and specification. Here we report the genetic characterization of Gliolectin, presumably a lectin, a cytoplasmic protein, significantly enriched in Golgi bodies. Its expression overlaps with regions where Notch is activated. Loss of gliolectin function results in ectopic veins, while gain of its function causes loss of wing veins. It positively regulates Enhancer of split mβ, a target of Notch signalling. These observations suggest that it is a positive regulator of Notch signalling during wing development in Drosophila. PMID:26505251

  6. Anti-EGFR immunonanoparticles containing IL12 and salmosin genes for targeted cancer gene therapy.

    PubMed

    Kim, Jung Seok; Kang, Seong Jae; Jeong, Hwa Yeon; Kim, Min Woo; Park, Sang Il; Lee, Yeon Kyung; Kim, Hong Sung; Kim, Keun Sik; Park, Yong Serk

    2016-09-01

    Tumor-directed gene delivery is of major interest in the field of cancer gene therapy. Varied functionalizations of non-viral vectors have been suggested to enhance tumor targetability. In the present study, we prepared two different types of anti-EGF receptor (EGFR) immunonanoparticles containing pDNA, neutrally charged liposomes and cationic lipoplexes, for tumor-directed transfection of cancer therapeutic genes. Even though both anti-EGFR immunonanoparticles had a high binding affinity to the EGFR-positive cancer cells, the anti-EGFR immunolipoplex formulation exhibited approximately 100-fold higher transfection to the target cells than anti-EGFR immunoliposomes. The lipoplex formulation also showed a higher transfection to SK-OV-3 tumor xenografts in mice. Thus, IL12 and/or salmosin genes were loaded in the anti-EGFR immunolipoplexes and intravenously administered to mice carrying SK-OV-3 tumors. Co-transfection of IL12 and salmosin genes using anti-EGFR immunolipoplexes significantly reduced tumor growth and pulmonary metastasis. Furthermore, combinatorial treatment with doxorubicin synergistically inhibited tumor growth. These results suggest that anti-EGFR immunolipoplexes containing pDNA encoding therapeutic genes could be utilized as a gene-transfer modality for cancer gene therapy.

  7. Structure and Function of the Su(H)-Hairless Repressor Complex, the Major Antagonist of Notch Signaling in Drosophila melanogaster

    PubMed Central

    Torella, Rubben; Preiss, Anette; Maier, Dieter; Kovall, Rhett A.

    2016-01-01

    Notch is a conserved signaling pathway that specifies cell fates in metazoans. Receptor-ligand interactions induce changes in gene expression, which is regulated by the transcription factor CBF1/Su(H)/Lag-1 (CSL). CSL interacts with coregulators to repress and activate transcription from Notch target genes. While the molecular details of the activator complex are relatively well understood, the structure-function of CSL-mediated repressor complexes is poorly defined. In Drosophila, the antagonist Hairless directly binds Su(H) (the fly CSL ortholog) to repress transcription from Notch targets. Here, we determine the X-ray structure of the Su(H)-Hairless complex bound to DNA. Hairless binding produces a large conformational change in Su(H) by interacting with residues in the hydrophobic core of Su(H), illustrating the structural plasticity of CSL molecules to interact with different binding partners. Based on the structure, we designed mutants in Hairless and Su(H) that affect binding, but do not affect formation of the activator complex. These mutants were validated in vitro by isothermal titration calorimetry and yeast two- and three-hybrid assays. Moreover, these mutants allowed us to solely characterize the repressor function of Su(H) in vivo. PMID:27404588

  8. Prospects for retinal cone-targeted gene therapy.

    PubMed

    Alexander, John J; Hauswirth, William W

    2008-06-01

    Gene therapy strategies that target therapeutic genes to retinal cones are a worthy goal both because cone photoreceptor diseases are severely vision limiting and because many retinal diseases that do not affect cones directly eventually lead to cone loss, the reason for eventual blindness. Human achromatopsia is a genetic disease of cones that renders them nonfunctional but otherwise intact. Thus, animal models of achromatopsia were used in conjunction with adeno-associated virus (AAV) vectors whose serotype efficiently transduces cones and with a promoter that limits transgene expression to cones. In the Gnat2(cpfl3) mouse model of one genetic form of human achromatopsia, we were able to demonstrate recovery of normal cone function and visual acuity after a single subretinal treatment of vector that supplied wild-type Gnat2 protein to cones. This validates the overall strategy of targeting cones using recombinant viral vectors and justifies a more complete examination of animal models of cone disease as a prelude to considering a clinical gene therapy trial. PMID:18596991

  9. Induction of hepatocellular carcinoma by in vivo gene targeting

    PubMed Central

    Wang, Pei-Rong; Xu, Mei; Toffanin, Sara; Li, Yi; Llovet, Josep M.; Russell, David W.

    2012-01-01

    The distinct phenotypic and prognostic subclasses of human hepatocellular carcinoma (HCC) are difficult to reproduce in animal experiments. Here we have used in vivo gene targeting to insert an enhancer-promoter element at an imprinted chromosome 12 locus in mice, thereby converting ∼1 in 20,000 normal hepatocytes into a focus of HCC with a single genetic modification. A 300-kb chromosomal domain containing multiple mRNAs, snoRNAs, and microRNAs was activated surrounding the integration site. An identical domain was activated at the syntenic locus in a specific molecular subclass of spontaneous human HCCs with a similar histological phenotype, which was associated with partial loss of DNA methylation. These findings demonstrate the accuracy of in vivo gene targeting in modeling human cancer and suggest future applications in studying various tumors in diverse animal species. In addition, similar insertion events produced by randomly integrating vectors could be a concern for liver-directed human gene therapy. PMID:22733778

  10. Quantitative determination of target gene with electrical sensor

    PubMed Central

    Zhang, Xuzhi; Li, Qiufen; Jin, Xianshi; Jiang, Cheng; Lu, Yong; Tavallaie, Roya; Gooding, J. Justin

    2015-01-01

    Integrating loop-mediated isothermal amplification (LAMP) with capacitively coupled contactless conductivity detection (C4D), we have developed an electrical sensor for the simultaneous amplification and detection of specific sequence DNA. Using the O26-wzy gene as a model, the amount of initial target gene could be determined via the threshold time obtained by monitoring the progression of the LAMP reaction in real time. Using the optimal conditions, a detection limit of 12.5 copy/μL can be obtained within 30 min. Monitoring the LAMP reaction by C4D has not only all the advantages that existing electrochemical methods have, but also additional attractive features including being completely free of carryover contamination risk, high simplicity and extremely low cost. These benefits all arise from the fact that the electrodes are separated from the reaction solution, that is C4D is a contactless method. Hence in proof of principle, the new strategy promises a robust, simple, cost-effective and sensitive method for quantitative determination of a target gene, that is applicable either to specialized labs or at point-of-care. PMID:26205714

  11. Regulation of targeted gene repair by intrinsic cellular processes.

    PubMed

    Engstrom, Julia U; Suzuki, Takayuki; Kmiec, Eric B

    2009-02-01

    Targeted gene alteration (TGA) is a strategy for correcting single base mutations in the DNA of human cells that cause inherited disorders. TGA aims to reverse a phenotype by repairing the mutant base within the chromosome itself, avoiding the introduction of exogenous genes. The process of how to accurately repair a genetic mutation is elucidated through the use of single-stranded DNA oligonucleotides (ODNs) that can enter the cell and migrate to the nucleus. These specifically designed ODNs hybridize to the target sequence and act as a beacon for nucleotide exchange. The key to this reaction is the frequency with which the base is corrected; this will determine whether the approach becomes clinically relevant or not. Over the course of the last five years, workers have been uncovering the role played by the cells in regulating the gene repair process. In this essay, we discuss how the impact of the cell on TGA has evolved through the years and illustrate ways that inherent cellular pathways could be used to enhance TGA activity. We also describe the cost to cell metabolism and survival when certain processes are altered to achieve a higher frequency of repair.

  12. Quantitative determination of target gene with electrical sensor

    NASA Astrophysics Data System (ADS)

    Zhang, Xuzhi; Li, Qiufen; Jin, Xianshi; Jiang, Cheng; Lu, Yong; Tavallaie, Roya; Gooding, J. Justin

    2015-07-01

    Integrating loop-mediated isothermal amplification (LAMP) with capacitively coupled contactless conductivity detection (C4D), we have developed an electrical sensor for the simultaneous amplification and detection of specific sequence DNA. Using the O26-wzy gene as a model, the amount of initial target gene could be determined via the threshold time obtained by monitoring the progression of the LAMP reaction in real time. Using the optimal conditions, a detection limit of 12.5 copy/μL can be obtained within 30 min. Monitoring the LAMP reaction by C4D has not only all the advantages that existing electrochemical methods have, but also additional attractive features including being completely free of carryover contamination risk, high simplicity and extremely low cost. These benefits all arise from the fact that the electrodes are separated from the reaction solution, that is C4D is a contactless method. Hence in proof of principle, the new strategy promises a robust, simple, cost-effective and sensitive method for quantitative determination of a target gene, that is applicable either to specialized labs or at point-of-care.

  13. Quantitative determination of target gene with electrical sensor.

    PubMed

    Zhang, Xuzhi; Li, Qiufen; Jin, Xianshi; Jiang, Cheng; Lu, Yong; Tavallaie, Roya; Gooding, J Justin

    2015-01-01

    Integrating loop-mediated isothermal amplification (LAMP) with capacitively coupled contactless conductivity detection (C(4)D), we have developed an electrical sensor for the simultaneous amplification and detection of specific sequence DNA. Using the O26-wzy gene as a model, the amount of initial target gene could be determined via the threshold time obtained by monitoring the progression of the LAMP reaction in real time. Using the optimal conditions, a detection limit of 12.5 copy/μL can be obtained within 30 min. Monitoring the LAMP reaction by C(4)D has not only all the advantages that existing electrochemical methods have, but also additional attractive features including being completely free of carryover contamination risk, high simplicity and extremely low cost. These benefits all arise from the fact that the electrodes are separated from the reaction solution, that is C(4)D is a contactless method. Hence in proof of principle, the new strategy promises a robust, simple, cost-effective and sensitive method for quantitative determination of a target gene, that is applicable either to specialized labs or at point-of-care.

  14. Jarid2 (Jumonji, AT rich interactive domain 2) regulates NOTCH1 expression via histone modification in the developing heart.

    PubMed

    Mysliwiec, Matthew R; Carlson, Clayton D; Tietjen, Josh; Hung, Holly; Ansari, Aseem Z; Lee, Youngsook

    2012-01-01

    Jarid2/Jumonji, the founding member of the Jmj factor family, critically regulates various developmental processes, including cardiovascular development. The Jmj family was identified as histone demethylases, indicating epigenetic regulation by Jmj proteins. Deletion of Jarid2 in mice resulted in cardiac malformation and increased endocardial Notch1 expression during development. Although Jarid2 has been shown to occupy the Notch1 locus in the developing heart, the precise molecular role of Jarid2 remains unknown. Here we show that deletion of Jarid2 results in reduced methylation of lysine 9 on histone H3 (H3K9) at the Notch1 genomic locus in embryonic hearts. Interestingly, SETDB1, a histone H3K9 methyltransferase, was identified as a putative cofactor of Jarid2 by yeast two-hybrid screening, and the physical interaction between Jarid2 and SETDB1 was confirmed by coimmunoprecipitation experiments. Concurrently, accumulation of SETDB1 at the site of Jarid2 occupancy was significantly reduced in Jarid2 knock out (KO) hearts. Employing genome-wide approaches, putative Jarid2 target genes regulated by SETDB1 via H3K9 methylation were identified in the developing heart by ChIP-chip. These targets are involved in biological processes that, when dysregulated, could manifest in the phenotypic defects observed in Jarid2 KO mice. Our data demonstrate that Jarid2 functions as a transcriptional repressor of target genes, including Notch1, through a novel process involving the modification of H3K9 methylation via specific interaction with SETDB1 during heart development. Therefore, our study provides new mechanistic insights into epigenetic regulation by Jarid2, which will enhance our understanding of the molecular basis of other organ development and biological processes.

  15. Sgs1 and Exo1 suppress targeted chromosome duplication during ends-in and ends-out gene targeting.

    PubMed

    Štafa, Anamarija; Miklenić, Marina; Zunar, Bojan; Lisnić, Berislav; Symington, Lorraine S; Svetec, Ivan-Krešimir

    2014-10-01

    Gene targeting is extremely efficient in the yeast Saccharomyces cerevisiae. It is performed by transformation with a linear, non-replicative DNA fragment carrying a selectable marker and containing ends homologous to the particular locus in a genome. However, even in S. cerevisiae, transformation can result in unwanted (aberrant) integration events, the frequency and spectra of which are quite different for ends-out and ends-in transformation assays. It has been observed that gene replacement (ends-out gene targeting) can result in illegitimate integration, integration of the transforming DNA fragment next to the target sequence and duplication of a targeted chromosome. By contrast, plasmid integration (ends-in gene targeting) is often associated with multiple targeted integration events but illegitimate integration is extremely rare and a targeted chromosome duplication has not been reported. Here we systematically investigated the influence of design of the ends-out assay on the success of targeted genetic modification. We have determined transformation efficiency, fidelity of gene targeting and spectra of all aberrant events in several ends-out gene targeting assays designed to insert, delete or replace a particular sequence in the targeted region of the yeast genome. Furthermore, we have demonstrated for the first time that targeted chromosome duplications occur even during ends-in gene targeting. Most importantly, the whole chromosome duplication is POL32 dependent pointing to break-induced replication (BIR) as the underlying mechanism. Moreover, the occurrence of duplication of the targeted chromosome was strikingly increased in the exo1Δ sgs1Δ double mutant but not in the respective single mutants demonstrating that the Exo1 and Sgs1 proteins independently suppress whole chromosome duplication during gene targeting. PMID:25089886

  16. Development of a successive targeting liposome with multi-ligand for efficient targeting gene delivery

    PubMed Central

    Ma, Kun; Shen, Haijun; Shen, Song; Xie, Men; Mao, Chuanbin; Qiu, Liyan; Jin, Yi

    2012-01-01

    Background A successful gene delivery system needs to breakthrough several barriers to allow efficient transgenic expression. In the present study, successive targeting liposomes (STL) were constructed by integrating various targeting groups into a nanoparticle to address this issue. Methods Polyethylenimine (PEI) 1800-triamcinolone acetonide (TA) with nuclear targeting capability was synthesized by a two-step reaction. Lactobionic acid was connected with cholesterol to obtain a compound of [(2-lactoylamido) ethylamino]formic acid cholesterol ester (CHEDLA) with hepatocyte-targeting capability. The liposome was modified with PEI 1800-TA and CHEDLA to prepare successive targeting liposome (STL). Its physicochemical properties and transfection efficiency were investigated both in vitro and in vivo. Results The diameter of STL was approximately 100 nm with 20 mV of potential. The confocal microscopy observation and potential assay verified that lipid bilayer of STL was decorated with PEI 1800-TA. Cytotoxicity of STL was significantly lower than that of PEI 1800-TA and PEI 25K. The transfection efficiency of 10% CHEDLA STL in HepG2 cells was the higher than of the latter two with serum. Its transfection efficiency was greatly reduced with excessive free galactose, indicating that STL was absorbed via galactose receptor-mediated endocytosis. The in vivo study in mice showed that 10% CHEDLA STL had better transgenic expression in liver than the other carriers. Conclusions STL with multi-ligand was able to overcome the various barriers to target nucleus and special cells and present distinctive transgenic expression. Therefore, it has a great potential for gene therapy as a nonviral carrier. PMID:21574214

  17. Notch1 deficiency decreases hepatic lipid accumulation by induction of fatty acid oxidation.

    PubMed

    Song, No-Joon; Yun, Ui Jeong; Yang, Sunghee; Wu, Chunyan; Seo, Cho-Rong; Gwon, A-Ryeong; Baik, Sang-Ha; Choi, Yuri; Choi, Bo Youn; Bahn, Gahee; Kim, Suji; Kwon, So-Mi; Park, Jin Su; Baek, Seung Hyun; Park, Tae Joo; Yoon, Keejung; Kim, Byung-Joon; Mattson, Mark P; Lee, Sung-Joon; Jo, Dong-Gyu; Park, Kye Won

    2016-01-01

    Notch signaling pathways modulate various cellular processes, including cell proliferation, differentiation, adhesion, and communication. Recent studies have demonstrated that Notch1 signaling also regulates hepatic glucose production and lipid synthesis. However, the effect of Notch1 signaling on hepatic lipid oxidation has not yet been directly investigated. To define the function of Notch1 signaling in hepatic lipid metabolism, wild type mice and Notch1 deficient antisense transgenic (NAS) mice were fed a high-fat diet. High-fat diet -fed NAS mice exhibited a marked reduction in hepatic triacylglycerol accumulation compared with wild type obese mice. The improved fatty liver was associated with an increased expression of hepatic genes involved in fatty acid oxidation. However, lipogenic genes were not differentially expressed in the NAS liver, suggesting lipolytic-specific regulatory effects by Notch1 signaling. Expression of fatty acid oxidative genes and the rate of fatty acid oxidation were also increased by inhibition of Notch1 signaling in HepG2 cells. In addition, similar regulatory effects on lipid accumulation were observed in adipocytes. Taken together, these data show that inhibition of Notch1 signaling can regulate the expression of fatty acid oxidation genes and may provide therapeutic strategies in obesity-induced hepatic steatosis. PMID:26786165

  18. Notch1 deficiency decreases hepatic lipid accumulation by induction of fatty acid oxidation

    PubMed Central

    Song, No-Joon; Yun, Ui Jeong; Yang, Sunghee; Wu, Chunyan; Seo, Cho-Rong; Gwon, A-Ryeong; Baik, Sang-Ha; Choi, Yuri; Choi, Bo Youn; Bahn, Gahee; Kim, Suji; Kwon, So-Mi; Park, Jin Su; Baek, Seung Hyun; Park, Tae Joo; Yoon, Keejung; Kim, Byung-Joon; Mattson, Mark P.; Lee, Sung-Joon; Jo, Dong-Gyu; Park, Kye Won

    2016-01-01

    Notch signaling pathways modulate various cellular processes, including cell proliferation, differentiation, adhesion, and communication. Recent studies have demonstrated that Notch1 signaling also regulates hepatic glucose production and lipid synthesis. However, the effect of Notch1 signaling on hepatic lipid oxidation has not yet been directly investigated. To define the function of Notch1 signaling in hepatic lipid metabolism, wild type mice and Notch1 deficient antisense transgenic (NAS) mice were fed a high-fat diet. High-fat diet -fed NAS mice exhibited a marked reduction in hepatic triacylglycerol accumulation compared with wild type obese mice. The improved fatty liver was associated with an increased expression of hepatic genes involved in fatty acid oxidation. However, lipogenic genes were not differentially expressed in the NAS liver, suggesting lipolytic-specific regulatory effects by Notch1 signaling. Expression of fatty acid oxidative genes and the rate of fatty acid oxidation were also increased by inhibition of Notch1 signaling in HepG2 cells. In addition, similar regulatory effects on lipid accumulation were observed in adipocytes. Taken together, these data show that inhibition of Notch1 signaling can regulate the expression of fatty acid oxidation genes and may provide therapeutic strategies in obesity-induced hepatic steatosis. PMID:26786165

  19. Notch Signaling Induces Rapid Degradation of Achaete-Scute Homolog 1

    PubMed Central

    Sriuranpong, Virote; Borges, Michael W.; Strock, Christopher L.; Nakakura, Eric K.; Watkins, D. Neil; Blaumueller, Christine M.; Nelkin, Barry D.; Ball, Douglas W.

    2002-01-01

    In neural development, Notch signaling plays a key role in restricting neuronal differentiation, promoting the maintenance of progenitor cells. Classically, Notch signaling causes transactivation of Hairy-enhancer of Split (HES) genes which leads to transcriptional repression of neural determination and differentiation genes. We now report that in addition to its known transcriptional mechanism, Notch signaling also leads to rapid degradation of the basic helix-loop-helix (bHLH) transcription factor human achaete-scute homolog 1 (hASH1). Using recombinant adenoviruses expressing active Notch1 in small-cell lung cancer cells, we showed that the initial appearance of Notch1 coincided with the loss of hASH1 protein, preceding the full decay of hASH1 mRNA. Overexpression of HES1 alone was capable of down-regulating hASH1 mRNA but could not replicate the acute reduction of hASH1 protein induced by Notch1. When adenoviral hASH1 was coinfected with Notch1, we still observed a dramatic and abrupt loss of the exogenous hASH1 protein, despite high levels of ongoing hASH1 RNA expression. Notch1 treatment decreased the apparent half-life of the adenoviral hASH1 protein and increased the fraction of hASH1 which was polyubiquitinylated. The proteasome inhibitor MG132 reversed the Notch1-induced degradation. The Notch RAM domain was dispensable but a lack of the OPA and PEST domains inactivated this Notch1 action. Overexpression of the hASH1-dimerizing partner E12 could protect hASH1 from degradation. This novel function of activated Notch to rapidly degrade a class II bHLH protein may prove to be important in many contexts in development and in cancer. PMID:11940670

  20. Notch signaling induces rapid degradation of achaete-scute homolog 1.

    PubMed

    Sriuranpong, Virote; Borges, Michael W; Strock, Christopher L; Nakakura, Eric K; Watkins, D Neil; Blaumueller, Christine M; Nelkin, Barry D; Ball, Douglas W

    2002-05-01

    In neural development, Notch signaling plays a key role in restricting neuronal differentiation, promoting the maintenance of progenitor cells. Classically, Notch signaling causes transactivation of Hairy-enhancer of Split (HES) genes which leads to transcriptional repression of neural determination and differentiation genes. We now report that in addition to its known transcriptional mechanism, Notch signaling also leads to rapid degradation of the basic helix-loop-helix (bHLH) transcription factor human achaete-scute homolog 1 (hASH1). Using recombinant adenoviruses expressing active Notch1 in small-cell lung cancer cells, we showed that the initial appearance of Notch1 coincided with the loss of hASH1 protein, preceding the full decay of hASH1 mRNA. Overexpression of HES1 alone was capable of down-regulating hASH1 mRNA but could not replicate the acute reduction of hASH1 protein induced by Notch1. When adenoviral hASH1 was coinfected with Notch1, we still observed a dramatic and abrupt loss of the exogenous hASH1 protein, despite high levels of ongoing hASH1 RNA expression. Notch1 treatment decreased the apparent half-life of the adenoviral hASH1 protein and increased the fraction of hASH1 which was polyubiquitinylated. The proteasome inhibitor MG132 reversed the Notch1-induced degradation. The Notch RAM domain was dispensable but a lack of the OPA and PEST domains inactivated this Notch1 action. Overexpression of the hASH1-dimerizing partner E12 could protect hASH1 from degradation. This novel function of activated Notch to rapidly degrade a class II bHLH protein may prove to be important in many contexts in development and in cancer.

  1. Active form Notch4 promotes the proliferation and differentiation of 3T3-L1 preadipocytes

    SciTech Connect

    Lai, Peng-Yeh; Tsai, Chong-Bin; Tseng, Min-Jen

    2013-01-18

    Highlights: ► Notch4IC modulates the ERK pathway and cell cycle to promote 3T3-L1 proliferation. ► Notch4IC facilitates 3T3-L1 differentiation by up-regulating proadipogenic genes. ► Notch4IC promotes proliferation during the early stage of 3T3-L1 adipogenesis. ► Notch4IC enhances differentiation during subsequent stages of 3T3-L1 adipogenesis. -- Abstract: Adipose tissue is composed of adipocytes, which differentiate from precursor cells in a process called adipogenesis. Many signal molecules are involved in the transcriptional control of adipogenesis, including the Notch pathway. Previous adipogenic studies of Notch have focused on Notch1 and HES1; however, the role of other Notch receptors in adipogenesis remains unclear. Q-RT-PCR analyses showed that the augmentation of Notch4 expression during the differentiation of 3T3-L1 preadipocytes was comparable to that of Notch1. To elucidate the role of Notch4 in adipogenesis, the human active form Notch4 (N4IC) was transiently transfected into 3T3-L1 cells. The expression of HES1, Hey1, C/EBPδ and PPARγ was up-regulated, and the expression of Pref-1, an adipogenic inhibitor, was down-regulated. To further characterize the effect of N4IC in adipogenesis, stable cells expressing human N4IC were established. The expression of N4IC promoted proliferation and enhanced differentiation of 3T3-L1 cells compared with those of control cells. These data suggest that N4IC promoted proliferation through modulating the ERK pathway and the cell cycle during the early stage of 3T3-L1 adipogenesis and facilitated differentiation through up-regulating adipogenic genes such as C/EBPα, PPARγ, aP2, LPL and HSL during the middle and late stages of 3T3-L1 adipogenesis.

  2. Specific genetic modifications of domestic animals by gene targeting and animal cloning.

    PubMed

    Wang, Bin; Zhou, Jiangfeng

    2003-11-13

    The technology of gene targeting through homologous recombination has been extremely useful for elucidating gene functions in mice. The application of this technology was thought impossible in the large livestock species until the successful creation of the first mammalian clone "Dolly" the sheep. The combination of the technologies for gene targeting of somatic cells with those of animal cloning made it possible to introduce specific genetic mutations into domestic animals. In this review, the principles of gene targeting in somatic cells and the challenges of nuclear transfer using gene-targeted cells are discussed. The relevance of gene targeting in domestic animals for applications in bio-medicine and agriculture are also examined.

  3. Regulation of Breast Cancer Stem Cell Activity by Signalling Through the Notch4 Receptor

    PubMed Central

    Harrison, Hannah; Farnie, Gillian; Howell, Sacha J; Rock, Rebecca E; Stylianou, Spyros; Brennan, Keith R; Bundred, Nigel J; Clarke, Robert B

    2012-01-01

    The Notch receptor signalling pathway plays an important role in breast development, regulation of stem cells and differentiation of luminal progenitor cells. The pathway also plays a significant role in breast cancer development and progression. However, which of the Notch receptors that regulate breast cancer stem cells is unknown. We assessed stem cell activity in breast cancer cell lines and nine primary human tumour samples. In vitro and in vivo breast cancer stem cell activity was enriched using selection of anoikis resistant cells or cells expressing the membrane phenotype ESA+/CD44+/CD24low. We compared the activation of Notch receptors in the breast cancer stem cell-enriched population to luminally differentiated cells and studied the effects of pathway inhibition, both in vitro and in vivo. We find that Notch4 signalling activity is 8-fold higher in the breast cancer stem cell-enriched cells compared to the differentiated cells while Notch1 activation is 4-fold lower in breast cancer stem cells. Furthermore, pharmacological or genetic Notch inhibition markedly reduced breast cancer stem cell activity in vitro, and significantly reduced tumour formation in vivo. Importantly, cells with Notch4 knock-down using specific shRNA formed fewer mammosphere colonies than Notch1 knock-down cells. In vivo Notch1 knock-down, like pharmacological inhibition, reduced the number and size of tumours but Notch4 knock-down suppressed tumour initiation completely. Our findings indicate that Notch4-targeted therapies will be more effective than targeting Notch1 in suppressing breast cancer recurrence initiated by breast cancer stem cells. PMID:20068161

  4. The many facets of Notch ligands

    PubMed Central

    D'souza, Brendan; Miyamoto, Alison; Weinmaster, Gerry

    2009-01-01

    The Notch signaling pathway regulates a diverse array of cell types and cellular processes and is tightly regulated by ligand binding. Both canonical and noncanonical Notch ligands have been identified that may account for some of the pleiotropic nature associated with Notch signaling. This review focuses on the molecular mechanisms by which Notch ligands function as signaling agonists and antagonists, and discusses different modes of activating ligands as well as findings that support intrinsic ligand signaling activity independent of Notch. Post-translational modification, proteolytic processing, endocytosis and membrane trafficking, as well as interactions with the actin cytoskeleton may contribute to the recently appreciated multi-functionality of Notch ligands. The regulation of Notch ligand expression by other signaling pathways provides a mechanism to coordinate Notch signaling with multiple cellular and developmental cues. The association of Notch ligands with inherited human disorders and cancer highlights the importance of understanding the molecular nature and activities intrinsic to Notch ligands. PMID:18758484

  5. The Ser/Thr Phosphatase PP2A Regulatory Subunit Widerborst Inhibits Notch Signaling

    PubMed Central

    Bose, Anasua; Majot, Adam T.; Bidwai, Ashok P.

    2014-01-01

    Drosophila Enhancer of split M8, an effector of Notch signaling, is regulated by protein kinase CK2. The phosphatase PP2A is thought to play an opposing (inhibitory) role, but the identity of the regulatory subunit was unknown. The studies described here reveal a role for the PP2A regulatory subunit widerborst (wdb) in three developmental contexts; the bristle, wing and the R8 photoreceptors of the eye. wdb overexpression elicits bristle and wing defects akin to reduced Notch signaling, whereas hypomorphic mutations in this PP2A subunit elicit opposite effects. We have also evaluated wdb functions using mutations in Notch and E(spl) that affect the eye. We find that the eye and R8 defects of the well-known Nspl mutation are enhanced by a hypomorphic allele of wdb, whereas they are strongly rescued by wdb overexpression. Similarly, ectopic wdb rescues the eye and R8 defects of the E(spl)D mutation, which affects the m8 gene. In addition, wdb overexpression also rescues the bristle defects of ectopically expressed M8, or the eye and R8 defects of its CK2 phosphomimetic variant M8-S159D. The latter finding suggests that PP2A may target M8 at highly conserved residues in the vicinity of the CK2 site, whose phosphorylation controls repression of Atonal and the R8 fate. Together, the studies identify PP2A-Wdb as a participant in Notch signaling, and suggest that M8 activity is controlled by phosphorylation and dephosphorylation. The conservation of the phosphorylation sites between Drosophila E(spl) and the HES/HER proteins from mammals, reptiles, amphibians, birds and fish raises the prospect that this mode of regulation is widespread. PMID:25006677

  6. A tumor targeted gene vector modified with G250 monoclonal antibody for gene therapy.

    PubMed

    Duan, Yajun; Zheng, Junnian; Han, Sufang; Wu, Yi; Wang, Yanming; Li, Deguan; Kong, Deling; Yu, Yaoting

    2008-04-21

    G250 is a tumor associated antigen that is found on > 90% of renal cell carcinoma (RCC). In order to develop a highly targeting gene vector for RCC gene therapy, G250 monoclonal antibody was prepared, purified and characterized. The antibody was chemically bound to Polyethylenimine (PEI) to form the IgG-PEI conjugate. The conjugate is capable of forming DNA complexes in the size of nano meters and with a narrow size distribution. The targeting effect and transfection efficiency were tested on five cell lines, ketr 3, Hela, ACHN, HepG2, and smooth muscle cells. The transfection was quantitatively determined by fluorescence activated cell sorting (FACS) and luciferase assay. The FACS results show that for G250 positive cells ketr 3 and Hela, the transfection efficiency of IgG-PEI are 2-fold higher than that of PEI. But for G250 negative cells, antibody modification has no effect on transfection. The expression of luciferase in ketr 3 cells which is expressed as enzyme activity is 15-fold and 61-fold higher than that in ACHN and SMC, respectively. In the presence of free antibody, the targeting effect of IgG-PEI is impaired and the transfection efficiency is normalized. It indicates that G250 antibody is an ideal targeting ligand for delivery of genes into RCC. Application of this IgG-PEI conjugate in RCC gene therapy will be of great interest. PMID:18316136

  7. Canonical and non-canonical Notch ligands

    PubMed Central

    D’SOUZA, BRENDAN; MELOTY-KAPELLA, LAURENCE; WEINMASTER, GERRY

    2015-01-01

    Notch signaling induced by canonical Notch ligands is critical for normal embryonic development and tissue homeostasis through the regulation of a variety of cell fate decisions and cellular processes. Activation of Notch signaling is normally tightly controlled by direct interactions with ligand-expressing cells and dysregulated Notch signaling is associated with developmental abnormalities and cancer. While canonical Notch ligands are responsible for the majority of Notch signaling, a diverse group of structurally unrelated non-canonical ligands has also been identified that activate Notch and likely contribute to the pleiotropic effects of Notch signaling. Soluble forms of both canonical and non-canonical ligands have been isolated, some of which block Notch signaling and could serve as natural inhibitors of this pathway. Ligand activity can also be indirectly regulated by other signaling pathways at the level of ligand expression, serving to spatio-temporally compartmentalize Notch signaling activity and integrate Notch signaling into a molecular network that orchestrates developmental events. Here, we review the molecular mechanisms underlying the dual role of Notch ligands as activators and inhibitors of Notch signaling. Additionally, evidence that Notch ligands function independent of Notch are presented. We also discuss how ligand post-translational modification, endocytosis, proteolysis and spatio-temporal expression regulate their signaling activity. PMID:20816393

  8. Modularly assembled designer TAL effector nucleases for targeted gene knockout and gene replacement in eukaryotes

    SciTech Connect

    Li, T; Huang, S; Zhao, XF; Wright, DA; Carpenter, S; Spalding, MH; Weeks, DP; Yang, B

    2011-08-08

    Recent studies indicate that the DNA recognition domain of transcription activator-like (TAL) effectors can be combined with the nuclease domain of FokI restriction enzyme to produce TAL effector nucleases (TALENs) that, in pairs, bind adjacent DNA target sites and produce double-strand breaks between the target sequences, stimulating non-homologous end-joining and homologous recombination. Here, we exploit the four prevalent TAL repeats and their DNA recognition cipher to develop a 'modular assembly' method for rapid production of designer TALENs (dTALENs) that recognize unique DNA sequence up to 23 bases in any gene. We have used this approach to engineer 10 dTALENs to target specific loci in native yeast chromosomal genes. All dTALENs produced high rates of site-specific gene disruptions and created strains with expected mutant phenotypes. Moreover, dTALENs stimulated high rates (up to 34%) of gene replacement by homologous recombination. Finally, dTALENs caused no detectable cytotoxicity and minimal levels of undesired genetic mutations in the treated yeast strains. These studies expand the realm of verified TALEN activity from cultured human cells to an intact eukaryotic organism and suggest that low-cost, highly dependable dTALENs can assume a significant role for gene modifications of value in human and animal health, agriculture and industry.

  9. Zinc-finger protein-targeted gene regulation: Genomewide single-gene specificity

    PubMed Central

    Tan, Siyuan; Guschin, Dmitry; Davalos, Albert; Lee, Ya-Li; Snowden, Andrew W.; Jouvenot, Yann; Zhang, H. Steven; Howes, Katherine; McNamara, Andrew R.; Lai, Albert; Ullman, Chris; Reynolds, Lindsey; Moore, Michael; Isalan, Mark; Berg, Lutz-Peter; Campos, Bradley; Qi, Hong; Spratt, S. Kaye; Case, Casey C.; Pabo, Carl O.; Campisi, Judith; Gregory, Philip D.

    2003-01-01

    Zinc-finger protein transcription factors (ZFP TFs) can be designed to control the expression of any desired target gene, and thus provide potential therapeutic tools for the study and treatment of disease. Here we report that a ZFP TF can repress target gene expression with single-gene specificity within the human genome. A ZFP TF repressor that binds an 18-bp recognition sequence within the promoter of the endogenous CHK2 gene gives a >10-fold reduction in CHK2 mRNA and protein. This level of repression was sufficient to generate a functional phenotype, as demonstrated by the loss of DNA damage-induced CHK2-dependent p53 phosphorylation. We determined the specificity of repression by using DNA microarrays and found that the ZFP TF repressed a single gene (CHK2) within the monitored genome in two different cell types. These data demonstrate the utility of ZFP TFs as precise tools for target validation, and highlight their potential as clinical therapeutics. PMID:14514889

  10. PKCζ regulates Notch receptor routing and activity in a Notch signaling-dependent manner.

    PubMed

    Sjöqvist, Marika; Antfolk, Daniel; Ferraris, Saima; Rraklli, Vilma; Haga, Cecilia; Antila, Christian; Mutvei, Anders; Imanishi, Susumu Y; Holmberg, Johan; Jin, Shaobo; Eriksson, John E; Lendahl, Urban; Sahlgren, Cecilia

    2014-04-01

    Activation of Notch signaling requires intracellular routing of the receptor, but the mechanisms controlling the distinct steps in the routing process is poorly understood. We identify PKCζ as a key regulator of Notch receptor intracellular routing. When PKCζ was inhibited in the developing chick central nervous system and in cultured myoblasts, Notch-stimulated cells were allowed to undergo differentiation. PKCζ phosphorylates membrane-tethered forms of Notch and regulates two distinct routing steps, depending on the Notch activation state. When Notch is activated, PKCζ promotes re-localization of Notch from late endosomes to the nucleus and enhances production of the Notch intracellular domain, which leads to increased Notch activity. In the non-activated state, PKCζ instead facilitates Notch receptor internalization, accompanied with increased ubiquitylation and interaction with the endosomal sorting protein Hrs. Collectively, these data identify PKCζ as a key regulator of Notch trafficking and demonstrate that distinct steps in intracellular routing are differentially modulated depending on Notch signaling status.

  11. Oncogenic programmes and Notch activity: an 'organized crime'?

    PubMed

    Dominguez, Maria

    2014-04-01

    The inappropriate Notch signalling can influence virtually all aspect of cancer, including tumour-cell growth, survival, apoptosis, angiogenesis, invasion and metastasis, although it does not do this alone. Hence, elucidating the partners of Notch that are active in cancer is now the focus of much intense research activity. The genetic toolkits available, coupled to the small size and short life of the fruit fly Drosophila melanogaster, makes this an inexpensive and effective animal model, suited to large-scale cancer gene discovery studies. The fly eye is not only a non-vital organ but its stereotyped size and disposition also means it is easy to screen for mutations that cause tumours and metastases and provides ample opportunities to test cancer theories and to unravel unanticipated nexus between Notch and other cancer genes, or to discover unforeseen Notch's partners in cancer. These studies suggest that Notch's oncogenic capacity is brought about not simply by increasing signal strength but through partnerships, whereby oncogenes gain more by cooperating than acting individually, as in a ring 'organized crime'. PMID:24780858

  12. Oncogenic programmes and Notch activity: an 'organized crime'?

    PubMed

    Dominguez, Maria

    2014-04-01

    The inappropriate Notch signalling can influence virtually all aspect of cancer, including tumour-cell growth, survival, apoptosis, angiogenesis, invasion and metastasis, although it does not do this alone. Hence, elucidating the partners of Notch that are active in cancer is now the focus of much intense research activity. The genetic toolkits available, coupled to the small size and short life of the fruit fly Drosophila melanogaster, makes this an inexpensive and effective animal model, suited to large-scale cancer gene discovery studies. The fly eye is not only a non-vital organ but its stereotyped size and disposition also means it is easy to screen for mutations that cause tumours and metastases and provides ample opportunities to test cancer theories and to unravel unanticipated nexus between Notch and other cancer genes, or to discover unforeseen Notch's partners in cancer. These studies suggest that Notch's oncogenic capacity is brought about not simply by increasing signal strength but through partnerships, whereby oncogenes gain more by cooperating than acting individually, as in a ring 'organized crime'.

  13. Fiber-modified adenoviruses for targeted gene therapy.

    PubMed

    Wu, Hongju; Curiel, David T

    2008-01-01

    Human adenovirus serotype 5 (Ad5) has been widely explored as a gene delivery vector. To achieve highly efficient and specific gene delivery, it is often necessary to re-direct Ad5 tropism. Because the capsid protein fiber plays an essential role in directing Ad5 infection, our laboratory attempted to re-target Ad5 through fiber modification. We have developed two strategies in this regard. One is a bi-specific adaptor protein strategy, in which the adaptor protein is designed to bind both the Ad5 fiber and an alternative cell-surface receptor. Another is genetic modification, in which alternative targeting motifs are genetically incorporated into the fiber knob domain so that the Ad5 vectors can infect cells through the alternative receptors. In this chapter, we will focus on the genetic fiber modification strategy and provide a detailed protocol for generation of fiber-modified Ad5 vectors. A series of techniques/procedures used in our laboratory will be described, which include the generation of fiber-modified Ad5 genome by homologous recombination in a bacterial system, rescuing the modified Ad5 viruses, virus amplification and purification, and virus titration.

  14. [Targeted modification of CCR5 gene in rabbits by TALEN].

    PubMed

    Tang, Chengcheng; Zhang, Quanjun; Li, Xiaoping; Fan, Nana; Yang, Yi; Quan, Longquan; Lai, Liangxue

    2014-04-01

    The lack of suitable animal model for HIV-1 infection has become a bottleneck for the development of AIDS vaccines and drugs. Wild-type rabbits can be infected by HIV-1 persistently and HIV-1 can be efficiently replicated resulting in syncytia in rabbit cell line co-expressing human CD4 and CCR5.Therefore, a rabbit highly expressing human CD4 and CCR5 may be an ideal animal model for AIDS disease study. In the present report, by using the efficient gene targeting technology, transcription activator-like effector nuclease (TALEN), we explored the feasibility of generating a HIV-1 model by knocking in human CD4 and CCR5 into rabbit genome. First we constructed two TALEN vectors targeting rabbit CCR5 gene and a vector with homologous arms. TALEN mRNAs and donor DNA were then co-injected into fertilized oocytes. After 3?5 days, 24 embryos were collected and used to conduct mutation analysis with PCR and sequencing. All the 24 embryos were detected with CCR5 knockouts and 5 were human CD4 and CCR5 knockins. Our results laid a foundation for establishing a new animal model for the study of AIDS.

  15. [Targeted modification of CCR5 gene in rabbits by TALEN].

    PubMed

    Tang, Chengcheng; Zhang, Quanjun; Li, Xiaoping; Fan, Nana; Yang, Yi; Quan, Longquan; Lai, Liangxue

    2014-04-01

    The lack of suitable animal model for HIV-1 infection has become a bottleneck for the development of AIDS vaccines and drugs. Wild-type rabbits can be infected by HIV-1 persistently and HIV-1 can be efficiently replicated resulting in syncytia in rabbit cell line co-expressing human CD4 and CCR5.Therefore, a rabbit highly expressing human CD4 and CCR5 may be an ideal animal model for AIDS disease study. In the present report, by using the efficient gene targeting technology, transcription activator-like effector nuclease (TALEN), we explored the feasibility of generating a HIV-1 model by knocking in human CD4 and CCR5 into rabbit genome. First we constructed two TALEN vectors targeting rabbit CCR5 gene and a vector with homologous arms. TALEN mRNAs and donor DNA were then co-injected into fertilized oocytes. After 3?5 days, 24 embryos were collected and used to conduct mutation analysis with PCR and sequencing. All the 24 embryos were detected with CCR5 knockouts and 5 were human CD4 and CCR5 knockins. Our results laid a foundation for establishing a new animal model for the study of AIDS. PMID:24846981

  16. Targeted Gene Therapy of Cancer: Second Amendment toward Holistic Therapy.

    PubMed

    Barar, Jaleh; Omidi, Yadollah

    2013-01-01

    It seems solid tumors are developing smart organs with specialized cells creating specified bio-territory, the so called "tumor microenvironment (TME)", in which there is reciprocal crosstalk among cancer cells, immune system cells and stromal cells. TME as an intricate milieu also consists of cancer stem cells (CSCs) that can resist against chemotherapies. In solid tumors, metabolism and vascularization appears to be aberrant and tumor interstitial fluid (TIF) functions as physiologic barrier. Thus, chemotherapy, immunotherapy and gene therapy often fail to provide cogent clinical outcomes. It looms that it is the time to accept the fact that initiation of cancer could be generation of another form of life that involves a cluster of thousands of genes, while we have failed to observe all aspects of it. Hence, the current treatment modalities need to be re-visited to cover all key aspects of disease using combination therapy based on the condition of patients. Perhaps personalized cluster of genes need to be simultaneously targeted.

  17. Gene Targeting to the Uteroplacental Circulation of Pregnant Guinea Pigs.

    PubMed

    Mehta, Vedanta; Ofir, Keren; Swanson, Anna; Kloczko, Ewa; Boyd, Michael; Barker, Hannah; Avdic-Belltheus, Adnan; Martin, John; Zachary, Ian; Peebles, Donald; David, Anna L

    2016-08-01

    Our study aimed to target adenoviral gene therapy to the uteroplacental circulation of pregnant guinea pigs in order to develop a novel therapy for fetal growth restriction. Four methods of delivery of an adenovirus encoding β-galactosidase (Ad.LacZ) were evaluated: intravascular injection using phosphate-buffered saline (PBS) into (1) uterine artery (UtA) or (2) internal iliac artery or external administration in (3) PBS or (4) pluronic F-127 gel (Sigma Aldrich). Postmortem examination was performed 4 to 7 days after gene transfer. Tissue transduction was assessed by X-gal histochemistry and enzyme-linked immunosorbent assay. External vascular application of the adenovirus vector in combination with pluronic gel had 91.7% success rate in terms of administration (85% maternal survival) and gave the best results for maternal/fetal survival and local transduction efficiency without any spread to maternal or fetal tissues. This study suggests an optimal method of gene delivery to the UtAs of a small rodent for preclinical studies.

  18. Jagged2 acts as a Delta-like Notch ligand during early hematopoietic cell fate decisions

    PubMed Central

    Van de Walle, Inge; De Smet, Greet; Gärtner, Martina; De Smedt, Magda; Waegemans, Els; Vandekerckhove, Bart; Leclercq, Georges; Plum, Jean; Aster, Jon C.; Bernstein, Irwin D.; Guidos, Cynthia J.; Kyewski, Bruno

    2011-01-01

    Notch signaling critically mediates various hematopoietic lineage decisions and is induced in mammals by Notch ligands that are classified into 2 families, Delta-like (Delta-like-1, -3 and -4) and Jagged (Jagged1 and Jagged2), based on structural homology with both Drosophila ligands Delta and Serrate, respectively. Because the functional differences between mammalian Notch ligands were still unclear, we have investigated their influence on early human hematopoiesis and show that Jagged2 affects hematopoietic lineage decisions very similarly as Delta-like-1 and -4, but very different from Jagged1. OP9 coculture experiments revealed that Jagged2, like Delta-like ligands, induces T-lineage differentiation and inhibits B-cell and myeloid development. However, dose-dependent Notch activation studies, gene expression analysis, and promoter activation assays indicated that Jagged2 is a weaker Notch1-activator compared with the Delta-like ligands, revealing a Notch1 specific signal strength hierarchy for mammalian Notch ligands. Strikingly, Lunatic-Fringe– mediated glycosylation of Notch1 potentiated Notch signaling through Delta-like ligands and also Jagged2, in contrast to Jagged1. Thus, our results reveal a unique role for Jagged1 in preventing the induction of T-lineage differentiation in hematopoietic stem cells and show an unexpected functional similarity between Jagged2 and the Delta-like ligands. PMID:21372153

  19. Notch signaling controls chondrocyte hypertrophy via indirect regulation of Sox9

    PubMed Central

    Kohn, Anat; Rutkowski, Timothy P; Liu, Zhaoyang; Mirando, Anthony J; Zuscik, Michael J; O’Keefe, Regis J; Hilton, Matthew J

    2015-01-01

    RBPjk-dependent Notch signaling regulates both the onset of chondrocyte hypertrophy and the progression to terminal chondrocyte maturation during endochondral ossification. It has been suggested that Notch signaling can regulate Sox9 transcription, although how this occurs at the molecular level in chondrocytes and whether this transcriptional regulation mediates Notch control of chondrocyte hypertrophy and cartilage development is unknown or controversial. Here we have provided conclusive genetic evidence linking RBPjk-dependent Notch signaling to the regulation of Sox9 expression and chondrocyte hypertrophy by examining tissue-specific Rbpjk mutant (Prx1Cre;Rbpjkf/f), Rbpjk mutant/Sox9 haploinsufficient (Prx1Cre;Rbpjkf/f;Sox9f/+), and control embryos for alterations in SOX9 expression and chondrocyte hypertrophy during cartilage development. These studies demonstrate that Notch signaling regulates the onset of chondrocyte maturation in a SOX9-dependent manner, while Notch-mediated regulation of terminal chondrocyte maturation likely functions independently of SOX9. Furthermore, our in vitro molecular analyses of the Sox9 promoter and Notch-mediated regulation of Sox9 gene expression in chondrogenic cells identified the ability of Notch to induce Sox9 expression directly in the acute setting, but suppresses Sox9 transcription with prolonged Notch signaling that requires protein synthesis of secondary effectors. PMID:26558140

  20. Epithelial Notch signaling regulates lung alveolar morphogenesis and airway epithelial integrity

    PubMed Central

    Tsao, Po-Nien; Matsuoka, Chisa; Wei, Shu-Chen; Sato, Atsuyasu; Sato, Susumu; Hasegawa, Koichi; Chen, Hung-kuan; Ling, Thai-Yen; Mori, Munemasa; Cardoso, Wellington V.; Morimoto, Mitsuru

    2016-01-01

    Abnormal enlargement of the alveolar spaces is a hallmark of conditions such as chronic obstructive pulmonary disease and bronchopulmonary dysplasia. Notch signaling is crucial for differentiation and regeneration and repair of the airway epithelium. However, how Notch influences the alveolar compartment and integrates this process with airway development remains little understood. Here we report a prominent role of Notch signaling in the epithelial–mesenchymal interactions that lead to alveolar formation in the developing lung. We found that alveolar type II cells are major sites of Notch2 activation and show by Notch2-specific epithelial deletion (Notch2cNull) a unique contribution of this receptor to alveologenesis. Epithelial Notch2 was required for type II cell induction of the PDGF-A ligand and subsequent paracrine activation of PDGF receptor-α signaling in alveolar myofibroblast progenitors. Moreover, Notch2 was crucial in maintaining the integrity of the epithelial and smooth muscle layers of the distal conducting airways. Our data suggest that epithelial Notch signaling regulates multiple aspects of postnatal development in the distal lung and may represent a potential target for intervention in pulmonary diseases. PMID:27364009

  1. Notch1 Regulates Hippocampal Plasticity Through Interaction with the Reelin Pathway, Glutamatergic Transmission and CREB Signaling

    PubMed Central

    Brai, Emanuele; Marathe, Swananda; Astori, Simone; Fredj, Naila Ben; Perry, Elisabeth; Lamy, Christophe; Scotti, Alessandra; Alberi, Lavinia

    2015-01-01

    Notch signaling plays a crucial role in adult brain function such as synaptic plasticity, memory and olfaction. Several reports suggest an involvement of this pathway in neurodegenerative dementia. Yet, to date, the mechanism underlying Notch activity in mature neurons remains unresolved. In this work, we investigate how Notch regulates synaptic potentiation and contributes to the establishment of memory in mice. We observe that Notch1 is a postsynaptic receptor with functional interactions with the Reelin receptor, apolipoprotein E receptor 2 (ApoER2) and the ionotropic receptor, N-methyl-D-aspartate receptor (NMDAR). Targeted loss of Notch1 in the hippocampal CA fields affects Reelin signaling by influencing Dab1 expression and impairs the synaptic potentiation achieved through Reelin stimulation. Further analysis indicates that loss of Notch1 affects the expression and composition of the NMDAR but not AMPAR. Glutamatergic signaling is further compromised through downregulation of CamKII and its secondary and tertiary messengers resulting in reduced cAMP response element-binding (CREB) signaling. Our results identify Notch1 as an important regulator of mechanisms involved in synaptic plasticity and memory formation. These findings emphasize the possible involvement of this signaling receptor in dementia. Highlights In this paper, we propose a mechanism for Notch1-dependent plasticity that likely underlies the function of Notch1 in memory formation: Notch1 interacts with another important developmental pathway, the Reelin cascade. Notch1 regulates both NMDAR expression and composition. Notch1 influences a cascade of cellular events culminating in CREB activation. PMID:26635527

  2. Performant Mutation Identification Using Targeted Next-Generation Sequencing of 14 Thoracic Aortic Aneurysm Genes.

    PubMed

    Proost, Dorien; Vandeweyer, Geert; Meester, Josephina A N; Salemink, Simone; Kempers, Marlies; Ingram, Christie; Peeters, Nils; Saenen, Johan; Vrints, Christiaan; Lacro, Ronald V; Roden, Dan; Wuyts, Wim; Dietz, Harry C; Mortier, Geert; Loeys, Bart L; Van Laer, Lut

    2015-08-01

    At least 14 causative genes have been identified for both syndromic and nonsyndromic forms of thoracic aortic aneurysm/dissection (TAA), an important cause of death in the industrialized world. Molecular confirmation of the diagnosis is increasingly important for gene-tailored patient management but consecutive, conventional molecular TAA gene screening is expensive and labor-intensive. To circumvent these problems, we developed a TAA gene panel for next-generation sequencing of 14 TAA genes. After validation, we applied the assay to 100 Marfan patients. We identified 90 FBN1 mutations, 44 of which were novel. In addition, Multiplex ligation-dependent probe amplification identified large deletions in six of the remaining samples, whereas false-negative results were excluded by Sanger sequencing of FBN1, TGFBR1, and TGFBR2 in the last four samples. Subsequently, we screened 55 syndromic and nonsyndromic TAA patients. We identified causal mutations in 15 patients (27%), one in each of the six following genes: ACTA2, COL3A1, TGFBR1, MYLK, SMAD3, SLC2A10 (homozygous), two in NOTCH1, and seven in FBN1. We conclude that our approach for TAA genetic testing overcomes the intrinsic hurdles of consecutive Sanger sequencing of all candidate genes and provides a powerful tool for the elaboration of clinical phenotypes assigned to different genes. PMID:25907466

  3. NOTCH3 Is Induced in Cancer-Associated Fibroblasts and Promotes Angiogenesis in Oral Squamous Cell Carcinoma

    PubMed Central

    Kayamori, Kou; Katsube, Ken-ichi; Sakamoto, Kei; Ohyama, Yoshio; Hirai, Hideaki; Yukimori, Akane; Ohata, Yae; Akashi, Takumi; Saitoh, Masao; Harada, Kiyoshi; Harada, Hiroyuki; Yamaguchi, Akira

    2016-01-01

    Recent studies have shown that Notch signaling is involved in many types of cancers, including oral squamous cell carcinomas (OSCCs). However, the role of Notch signaling in the tumor microenvironment is not yet fully understood. In this study, we investigated the roles of NOTCH3 signaling in cancer associated fibroblasts (CAFs) in OSCCs. Immunohistochemical study of 93 human tongue OSCC cases indicated that about one third of OSCCs showed NOTCH3 expression in CAFs, and that this expression significantly correlated with tumor-size. In vitro study showed that OSCC cell lines, especially HO1-N-1 cells stimulated NOTCH3 expression in normal human dermal fibroblasts (NHDFs) through direct cell-to-cell contact. Immunohistochemical and morphometric analysis using human OSCC samples demonstrated that NOTCH3 expression in CAFs significantly correlated with micro-vessel density in cancer stroma. In vitro angiogenesis assays involving co-culture of NHDFs with HO1-N-1 and human umbilical endothelial cells (HUVECs), and NOTCH3 knockdown in NHDFs using siRNA, demonstrated that HO1-N-1 cells significantly promoted tube formation dependent on NOTCH3-expression in NHDFs. Moreover, NOTCH3 expression in CAFs was related to poor prognosis of the OSCC patients. This work provides a new insight into the role of Notch signaling in CAFs associated with tumor angiogenesis and the possibility of NOTCH3-targeted molecular therapy in OSCCs. PMID:27124156

  4. Targeted insertion of foreign genes into the tobacco plastid genome without physical linkage to the selectable marker gene

    SciTech Connect

    Carrer, H.; Maliga, P.

    1995-08-01

    To determine whether targeted DNA insertion into the tobacco plastid genome can be obtained without physical linkage to a selectable marker gene, we carried out biolistic transformation of chloroplasts in tobacco leaf segments with a 1:1 mix of two independently targeted antibiotic resistance genes. Plastid transformants were selected by spectinomycin resistance due to expression of an integrated aadA gene. Integration of the unselected kanamycin resistance (kan) gene into the same plastid genome was established by Southern probing in {approx}20% of the spectinomycin-selected clones. Efficient cotransformation will facilitate targeted plastid genome modification without physical linkage to a marker gene. 26 refs., 5 figs., 1 tab.

  5. Strategies on the nuclear-targeted delivery of genes

    PubMed Central

    Yao, Jing; Fan, Ying; Li, Yuanke; Huang, Leaf

    2016-01-01

    To improve the nuclear-targeted delivery of non-viral vectors, extensive effort has been carried out on the development of smart vectors which could overcome multiple barriers. The nuclear envelope presents a major barrier to transgene delivery. Viruses are capable of crossing the nuclear envelope to efficiently deliver their genome into the nucleus through the specialized protein components. However, non-viral vectors are preferred over viral ones because of the safety concerns associated with the latter. Non-viral delivery systems have been designed to include various types of components to enable nuclear translocation at the periphery of the nucleus. This review summarizes the progress of research regarding nuclear transport mechanisms. “Smart” non-viral vectors that have been modified by peptides and other small molecules are able to facilitate the nuclear translocation and enhance the efficacy of gene expression. The resulting technology may also enhance delivery of other macromolecules to the nucleus. PMID:23964565

  6. Targeted disruption of the mouse Lipoma Preferred Partner gene

    SciTech Connect

    Vervenne, Hilke B.V.K.; Crombez, Koen R.M.O.; Delvaux, Els L.; Janssens, Veerle; Ven, Wim J.M. van de Petit, Marleen M.R.

    2009-02-06

    LPP (Lipoma Preferred Partner) is a zyxin-related cell adhesion protein that is involved in the regulation of cell migration. We generated mice with a targeted disruption of the Lpp gene and analysed the importance of Lpp for embryonic development and adult functions. Aberrant Mendelian inheritance in heterozygous crosses suggested partial embryonic lethality of Lpp{sup -/-} females. Fertility of Lpp{sup -/-} males was proven to be normal, however, females from Lpp{sup -/-} x Lpp{sup -/-} crosses produced a strongly reduced number of offspring, probably due to a combination of female embryonic lethality and aberrant pregnancies. Apart from these developmental and reproductive abnormalities, Lpp{sup -/-} mice that were born reached adulthood without displaying any additional macroscopic defects. On the other hand, Lpp{sup -/-} mouse embryonic fibroblasts exhibited reduced migration capacity, reduced viability, and reduced expression of some Lpp interaction partners. Finally, we discovered a short nuclear form of Lpp, expressed mainly in testis via an alternative promoter.

  7. Notch signaling is essential for ventricular chamber development.

    PubMed

    Grego-Bessa, Joaquín; Luna-Zurita, Luis; del Monte, Gonzalo; Bolós, Victoria; Melgar, Pedro; Arandilla, Alejandro; Garratt, Alistair N; Zang, Heesuk; Mukouyama, Yoh-Suke; Chen, Hanying; Shou, Weinian; Ballestar, Esteban; Esteller, Manel; Rojas, Ana; Pérez-Pomares, José María; de la Pompa, José Luis

    2007-03-01

    Ventricular chamber morphogenesis, first manifested by trabeculae formation, is crucial for cardiac function and embryonic viability and depends on cellular interactions between the endocardium and myocardium. We show that ventricular Notch1 activity is highest at presumptive trabecular endocardium. RBPJk and Notch1 mutants show impaired trabeculation and marker expression, attenuated EphrinB2, NRG1, and BMP10 expression and signaling, and decreased myocardial proliferation. Functional and molecular analyses show that Notch inhibition prevents EphrinB2 expression, and that EphrinB2 is a direct Notch target acting upstream of NRG1 in the ventricles. However, BMP10 levels are found to be independent of both EphrinB2 and NRG1 during trabeculation. Accordingly, exogenous BMP10 rescues the myocardial proliferative defect of in vitro-cultured RBPJk mutants, while exogenous NRG1 rescues differentiation in parallel. We suggest that during trabeculation Notch independently regulates cardiomyocyte proliferation and differentiation, two exquisitely balanced processes whose perturbation may result in congenital heart disease.

  8. Notch Signaling is Essential for Ventricular Chamber Development

    PubMed Central

    Grego-Bessa, Joaquín; Luna-Zurita, Luis; Monte, Gonzalo del; Bolós, Victoria; Melgar, Pedro; Arandilla, Alejandro; Garratt, Alistair N.; Zang, Heesuk; Mukouyama, Yoh-suke; Chen, Hanying; Shou, Weinian; Ballestar, Esteban; Esteller, Manel; Rojas, Ana; Pérez-Pomares, José María; de la Pompa, José Luis

    2009-01-01

    Summary Ventricular chamber morphogenesis, first manifested by trabeculae formation, is crucial for cardiac function and embryonic viability and depends on cellular interactions between endocardium and myocardium. We show that ventricular Notch1 activity is highest at presumptive trabecular endocardium. RBPJk and Notch1 mutants show impaired trabeculation and marker expression, attenuated EphrinB2, NRG1 and BMP10 expression and signaling and decreased myocardial proliferation. Functional and molecular analyses show that Notch inhibition prevents EphrinB2 expression and that EphrinB2 is a direct Notch target acting upstream of NRG1 in the ventricles. However, BMP10 levels are found to be independent of both EphrinB2 and NRG1 during trabeculation. Accordingly, exogenous BMP10 rescues the myocardial proliferative defect of in vitro cultured RBPJk mutants, while exogenous NRG1 rescues differentiation in parallel. We suggest that during trabeculation Notch independently regulates cardiomyocyte proliferation and differentiation, two exquisitely balanced processes whose perturbation may result in congenital heart disease. PMID:17336907

  9. A Bovine Herpesvirus 1 Protein Expressed in Latently Infected Neurons (ORF2) Promotes Neurite Sprouting in the Presence of Activated Notch1 or Notch3

    PubMed Central

    Sinani, Devis; Frizzo da Silva, Leticia

    2013-01-01

    Bovine herpesvirus 1 (BHV-1) infection induces clinical symptoms in the upper respiratory tract, inhibits immune responses, and can lead to life-threatening secondary bacterial infections. Following acute infection, BHV-1 establishes latency in sensory neurons within trigeminal ganglia, but stress can induce reactivation from latency. The latency-related (LR) RNA is the only viral transcript abundantly expressed in latently infected sensory neurons. An LR mutant virus with stop codons at the amino terminus of the first open reading frame (ORF) in the LR gene (ORF2) is not reactivated from latency, in part because it induces higher levels of apoptosis in infected neurons. ORF2 inhibits apoptosis in transiently transfected cells, suggesting that it plays a crucial role in the latency-reactivation cycle. ORF2 also interacts with Notch1 or Notch3 and inhibits its ability to trans activate certain viral promoters. Notch3 RNA and protein levels are increased during reactivation from latency, suggesting that Notch may promote reactivation. Activated Notch signaling interferes with neuronal differentiation, in part because neurite and axon generation is blocked. In this study, we demonstrated that ORF2 promotes neurite formation in mouse neuroblastoma cells overexpressing Notch1 or Notch3. ORF2 also interfered with Notch-mediated trans activation of the promoter that regulates the expression of Hairy Enhancer of Split 5, an inhibitor of neurite formation. Additional studies provided evidence that ORF2 promotes the degradation of Notch3, but not that of Notch1, in a proteasome-dependent manner. In summary, these studies suggest that ORF2 promotes a mature neuronal phenotype that enhances the survival of infected neurons and consequently increases the pool of latently infected neurons. PMID:23152506

  10. Reduction of Nfia gene expression and subsequent target genes by binge alcohol in the fetal brain.

    PubMed

    Mandal, Chanchal; Park, Ji Hyun; Lee, Hyung Tae; Seo, Hyemyung; Chung, Il Yup; Choi, Ihn Geun; Jung, Kyoung Hwa; Chai, Young Gyu

    2015-06-26

    The objective of the present study was to investigate the changes in gene expression in the fetal brain (forebrain and hippocampus) caused by maternal binge alcohol consumption. Pregnant C57BL/6J mice were treated intragastrically with distilled phosphate-buffered saline (PBS) or ethanol (2.9 g/kg) from embryonic day (ED) 8-12. Microarray analysis revealed that a significant number of genes were altered at ED 18 in the developing brain. Specifically, in hippocampus, nuclear factor one alpha (Nfia) and three N-methyl-D-aspartate (Nmda) receptors (Nmdar1, Nmdar2b, and Nmdar2d) were down-regulated. The transcription factor Nfia controls gliogenesis, cell proliferation and Nmda-induced neuronal survival by regulating the expression of target genes. Some of the Nfia-target gene (Aldh1a, Folh1, Gjb6, Fgf1, Neurod1, Sept4, and Ntsr2) expressions were also altered as expected. These results suggest that the altered expression of Nfia and Nmda receptors may be associated with the etiology of fetal alcohol syndrome (FAS). The data presented in this report will contribute to the understanding of the molecular mechanisms associated with the effects of alcohol in FASD individuals.

  11. Identification of microRNA-regulated gene networks by expression analysis of target genes

    PubMed Central

    Gennarino, Vincenzo Alessandro; D'Angelo, Giovanni; Dharmalingam, Gopuraja; Fernandez, Serena; Russolillo, Giorgio; Sanges, Remo; Mutarelli, Margherita; Belcastro, Vincenzo; Ballabio, Andrea; Verde, Pasquale; Sardiello, Marco; Banfi, Sandro

    2012-01-01

    MicroRNAs (miRNAs) and transcription factors control eukaryotic cell proliferation, differentiation, and metabolism through their specific gene regulatory networks. However, differently from transcription factors, our understanding of the processes regulated by miRNAs is currently limited. Here, we introduce gene network analysis as a new means for gaining insight into miRNA biology. A systematic analysis of all human miRNAs based on Co-expression Meta-analysis of miRNA Targets (CoMeTa) assigns high-resolution biological functions to miRNAs and provides a comprehensive, genome-scale analysis of human miRNA regulatory networks. Moreover, gene cotargeting analyses show that miRNAs synergistically regulate cohorts of genes that participate in similar processes. We experimentally validate the CoMeTa procedure through focusing on three poorly characterized miRNAs, miR-519d/190/340, which CoMeTa predicts to be associated with the TGFβ pathway. Using lung adenocarcinoma A549 cells as a model system, we show that miR-519d and miR-190 inhibit, while miR-340 enhances TGFβ signaling and its effects on cell proliferation, morphology, and scattering. Based on these findings, we formalize and propose co-expression analysis as a general paradigm for second-generation procedures to recognize bona fide targets and infer biological roles and network communities of miRNAs. PMID:22345618

  12. Reduction of Nfia gene expression and subsequent target genes by binge alcohol in the fetal brain.

    PubMed

    Mandal, Chanchal; Park, Ji Hyun; Lee, Hyung Tae; Seo, Hyemyung; Chung, Il Yup; Choi, Ihn Geun; Jung, Kyoung Hwa; Chai, Young Gyu

    2015-06-26

    The objective of the present study was to investigate the changes in gene expression in the fetal brain (forebrain and hippocampus) caused by maternal binge alcohol consumption. Pregnant C57BL/6J mice were treated intragastrically with distilled phosphate-buffered saline (PBS) or ethanol (2.9 g/kg) from embryonic day (ED) 8-12. Microarray analysis revealed that a significant number of genes were altered at ED 18 in the developing brain. Specifically, in hippocampus, nuclear factor one alpha (Nfia) and three N-methyl-D-aspartate (Nmda) receptors (Nmdar1, Nmdar2b, and Nmdar2d) were down-regulated. The transcription factor Nfia controls gliogenesis, cell proliferation and Nmda-induced neuronal survival by regulating the expression of target genes. Some of the Nfia-target gene (Aldh1a, Folh1, Gjb6, Fgf1, Neurod1, Sept4, and Ntsr2) expressions were also altered as expected. These results suggest that the altered expression of Nfia and Nmda receptors may be associated with the etiology of fetal alcohol syndrome (FAS). The data presented in this report will contribute to the understanding of the molecular mechanisms associated with the effects of alcohol in FASD individuals. PMID:25982323

  13. Id-1 gene and gene products as therapeutic targets for treatment of breast cancer and other types of carcinoma

    DOEpatents

    Desprez, Pierre-Yves; Campisi, Judith

    2014-08-19

    A method for treatment of breast cancer and other types of cancer. The method comprises targeting and modulating Id-1 gene expression, if any, for the Id-1 gene, or gene products in breast or other epithelial cancers in a patient by delivering products that modulate Id-1 gene expression. When expressed, Id-1 gene is a prognostic indicator that cancer cells are invasive and metastatic.

  14. Visualized Gene Network Reveals the Novel Target Transcripts Sox2 and Pax6 of Neuronal Development in Trans-Placental Exposure to Bisphenol A

    PubMed Central

    Yang, Chung-Wei; Chou, Wei-Chun; Chen, Kuan-Hsueh; Cheng, An-Lin; Mao, I-Fang; Chao, How-Ran; Chuang, Chun-Yu

    2014-01-01

    Background Bisphenol A (BPA) is a ubiquitous endocrine disrupting chemical in our daily life, and its health effect in response to prenatal exposure is still controversial. Early-life BPA exposure may impact brain development and contribute to childhood neurological disorders. The aim of the present study was to investigate molecular target genes of neuronal development in trans-placental exposure to BPA. Methodology A meta-analysis of three public microarray datasets was performed to screen for differentially expressed genes (DEGs) in exposure to BPA. The candidate genes of neuronal development were identified from gene ontology analysis in a reconstructed neuronal sub-network, and their gene expressions were determined using real-time PCR in 20 umbilical cord blood samples dichotomized into high and low BPA level groups upon the median 16.8 nM. Principal Findings Among 36 neuronal transcripts sorted from DAVID ontology clusters of 457 DEGs using the analysis of Bioconductor limma package, we found two neuronal genes, sex determining region Y-box 2 (Sox2) and paired box 6 (Pax6), had preferentially down-regulated expression (Bonferroni correction p-value <10−4 and log2-transformed fold change ≤−1.2) in response to BPA exposure. Fetal cord blood samples had the obviously attenuated gene expression of Sox2 and Pax6 in high BPA group referred to low BPA group. Visualized gene network of Cytoscape analysis showed that Sox2 and Pax6 which were contributed to neural precursor cell proliferation and neuronal differentiation might be down-regulated through sonic hedgehog (Shh), vascular endothelial growth factor A (VEGFA) and Notch signaling. Conclusions These results indicated that trans-placental BPA exposure down-regulated gene expression of Sox2 and Pax6 potentially underlying the adverse effect on childhood neuronal development. PMID:25051057

  15. Nas transgenic mouse line allows visualization of Notch pathway activity in vivo

    PubMed Central

    Souilhol, Céline; Cormier, Sarah; Monet, Marie; Vandormael-Pournin, Sandrine; Joutel, Anne; Babinet, Charles; Cohen-Tannoudji, Michel

    2006-01-01

    The Notch signalling pathway plays multiple and important roles in mammals. However, several aspects of its action, in particular the precise mapping of its sites of activity, remain unclear. To address this issue, we have generated a transgenic line carrying a construct consisting of a nls-lacZ reporter gene under the control of a minimal promoter and multiple RBP-Jκ binding sites. Here we show that this transgenic line, we named NAS for Notch Activity Sensor, displays an expression profile that is consistent with current knowledge on Notch activity sites in mice, even though it may not report on all these sites. Moreover, we observe that NAS transgene expression is abolished in a RBP-Jκ deficient background indicating that it indeed requires Notch/RBP-Jκ signalling pathway activity. Thus, the NAS transgenic line constitutes a valuable and versatile tool to gain further insights into the complex and various functions of the Notch signalling pathway. PMID:16708386

  16. Delta/Notch-Like EGF-Related Receptor (DNER) Is Not a Notch Ligand.

    PubMed

    Greene, Maxwell; Lai, Yongjie; Pajcini, Kostandin; Bailis, Will; Pear, Warren S; Lancaster, Eric

    2016-01-01

    Delta/Notch-like EGF-related receptor (DNER) has been reported to act as a Notch ligand, despite lacking a Delta/Serrate/Lag (DSL) binding domain common to all other known ligands. The established Notch ligand Delta-like 1 (DLL1), but not DNER, activated Notch1 in a luciferase assay, prevented the differentiation of myoblasts through Notch signaling, and bound Notch-fc in a cell-based assay. DNER is not a Notch ligand and its true function remains unknown. PMID:27622512

  17. Delta/Notch-Like EGF-Related Receptor (DNER) Is Not a Notch Ligand.

    PubMed

    Greene, Maxwell; Lai, Yongjie; Pajcini, Kostandin; Bailis, Will; Pear, Warren S; Lancaster, Eric

    2016-01-01

    Delta/Notch-like EGF-related receptor (DNER) has been reported to act as a Notch ligand, despite lacking a Delta/Serrate/Lag (DSL) binding domain common to all other known ligands. The established Notch ligand Delta-like 1 (DLL1), but not DNER, activated Notch1 in a luciferase assay, prevented the differentiation of myoblasts through Notch signaling, and bound Notch-fc in a cell-based assay. DNER is not a Notch ligand and its true function remains unknown.

  18. Delta/Notch-Like EGF-Related Receptor (DNER) Is Not a Notch Ligand

    PubMed Central

    Lai, Yongjie; Pajcini, Kostandin; Bailis, Will; Pear, Warren S.; Lancaster, Eric

    2016-01-01

    Delta/Notch-like EGF-related receptor (DNER) has been reported to act as a Notch ligand, despite lacking a Delta/Serrate/Lag (DSL) binding domain common to all other known ligands. The established Notch ligand Delta-like 1 (DLL1), but not DNER, activated Notch1 in a luciferase assay, prevented the differentiation of myoblasts through Notch signaling, and bound Notch-fc in a cell-based assay. DNER is not a Notch ligand and its true function remains unknown. PMID:27622512

  19. Kaposi's sarcoma-associated herpesvirus viral interferon regulatory factor 4 (vIRF4/K10) is a novel interaction partner of CSL/CBF1, the major downstream effector of Notch signaling.

    PubMed

    Heinzelmann, Katharina; Scholz, Barbara A; Nowak, Agnes; Fossum, Even; Kremmer, Elisabeth; Haas, Juergen; Frank, Ronald; Kempkes, Bettina

    2010-12-01

    In cells infected with the Kaposi's sarcoma-associated herpesvirus (KSHV), CSL/CBF1 signaling is essential for viral replication and promotes the survival of KSHV-infected cells. CSL/CBF1 is a DNA adaptor molecule which recruits coactivator and corepressor complexes to regulate viral and cellular gene transcription and which is a major downstream effector molecule of activated Notch. The interaction of KSHV RTA and LANA with CSL/CBF1 has been shown to balance the lytic and latent viral life cycle. Here we report that a third KSHV protein, viral interferon regulatory factor 4 (vIRF4/K10), but none of the three other KSHV-encoded vIRFs, interacts with CSL/CBF1. Two regions of vIRF4 with dissimilar affinities contribute to CSL/CBF1 binding. Similar to Notch, vIRF4 targets the hydrophobic pocket in the beta trefoil domain of CSL/CBF1 through a short peptide motif which closely resembles a motif found in Notch but does not strictly follow the ΦWΦP consensus conserved in human and mouse Notch proteins. Our results suggest that vIRF4 might compete with Notch for CSL/CBF1 binding and signaling. PMID:20861242

  20. Kaposi's Sarcoma-Associated Herpesvirus Viral Interferon Regulatory Factor 4 (vIRF4/K10) Is a Novel Interaction Partner of CSL/CBF1, the Major Downstream Effector of Notch Signaling▿

    PubMed Central

    Heinzelmann, Katharina; Scholz, Barbara A.; Nowak, Agnes; Fossum, Even; Kremmer, Elisabeth; Haas, Juergen; Frank, Ronald; Kempkes, Bettina

    2010-01-01

    In cells infected with the Kaposi's sarcoma-associated herpesvirus (KSHV), CSL/CBF1 signaling is essential for viral replication and promotes the survival of KSHV-infected cells. CSL/CBF1 is a DNA adaptor molecule which recruits coactivator and corepressor complexes to regulate viral and cellular gene transcription and which is a major downstream effector molecule of activated Notch. The interaction of KSHV RTA and LANA with CSL/CBF1 has been shown to balance the lytic and latent viral life cycle. Here we report that a third KSHV protein, viral interferon regulatory factor 4 (vIRF4/K10), but none of the three other KSHV-encoded vIRFs, interacts with CSL/CBF1. Two regions of vIRF4 with dissimilar affinities contribute to CSL/CBF1 binding. Similar to Notch, vIRF4 targets the hydrophobic pocket in the beta trefoil domain of CSL/CBF1 through a short peptide motif which closely resembles a motif found in Notch but does not strictly follow the ΦWΦP consensus conserved in human and mouse Notch proteins. Our results suggest that vIRF4 might compete with Notch for CSL/CBF1 binding and signaling. PMID:20861242

  1. Utility of LRF/Pokemon and NOTCH1 protein expression in the distinction between nodular lymphocyte-predominant Hodgkin lymphoma and classical Hodgkin lymphoma.

    PubMed

    Bohn, Olga; Maeda, Takahiro; Filatov, Alexander; Lunardi, Andrea; Pandolfi, Pier Paolo; Teruya-Feldstein, Julie

    2014-02-01

    Classical Hodgkin lymphoma (CHL) and nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) are considered separate entities with different prognosis and treatment. However, morphologic features can be similar and immunohistochemical studies are essential in the distinction; thus, determination of additional biomarkers is of utmost importance. LRF/Pokemon is a proto-oncogene, an interacting partner co-expressed with BCL6 in germinal centers and highly expressed in diffuse large B-cell lymphoma and follicular lymphoma. Conversely, loss of the LRF gene in mouse hematopoietic stem cells results in complete block of early B cell development with concomitant Notch de-repression, indicating its critical role in B versus T cell fate decision at the hematopoietic stem cell stage. For the first time, we show that LRF/Pokemon is predominantly expressed in NLPHL cases as is BCL6 with low to absent NOTCH1 protein expression; while Hodgkin Reed-Sternberg (HRS) cells in CHL show low to absent BCL6 and LRF/Pokemon expression with higher NOTCH1 expression. We illustrate a potential functional interaction between LRF and BCL6 in NLPHL pathogenesis, and differential expression of LRF/Pokemon and NOTCH1 proteins in CHL thus showing differential expression, making for an additional diagnostic marker and therapeutic target. PMID:24326827

  2. Utility of LRF/Pokemon and NOTCH1 Protein Expression in the Distinction of Nodular Lymphocyte-Predominant Hodgkin Lymphoma and Classical Hodgkin Lymphoma

    PubMed Central

    Bohn, Olga; Maeda, Takahiro; Filatov, Alexander; Lunardi, Andrea; Pandolfi, Pier Paolo; Teruya-Feldstein, Julie

    2014-01-01

    Classical Hodgkin lymphoma (CHL) and nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) are considered separate entities with different prognosis and treatment. However, morphologic features can be similar and immunohistochemical studies are essential in the distinction; thus, determination of additional biomarkers is of utmost importance. LRF/Pokemon is a protooncogene, an interacting partner co-expressed with BCL6 in germinal centers and highly expressed in diffuse large B-cell lymphoma and follicular lymphoma. Conversely, loss of the LRF gene in mouse hematopoietic stem cells results in complete block of early B cell development with concomitant Notch derepression, indicating its critical role in B versus T cell fate decision at the hematopoietic stem cell stage. For the first time, we show that LRF/Pokemon is predominantly expressed in NLPHL cases as is BCL6 with low to absent NOTCH1 protein expression; while Hodgkin Reed-Sternberg (HRS) cells in CHL show low to absent BCL6 and LRF/Pokemon expression with higher NOTCH1 expression. We illustrate a potential functional interaction between LRF and BCL6 in NLPHL pathogenesis, and differential expression of LRF/Pokemon and NOTCH1 proteins in CHL thus showing differential expression, making for an additional diagnostic marker and therapeutic target. PMID:24326827

  3. Utility of LRF/Pokemon and NOTCH1 protein expression in the distinction between nodular lymphocyte-predominant Hodgkin lymphoma and classical Hodgkin lymphoma.

    PubMed

    Bohn, Olga; Maeda, Takahiro; Filatov, Alexander; Lunardi, Andrea; Pandolfi, Pier Paolo; Teruya-Feldstein, Julie

    2014-02-01

    Classical Hodgkin lymphoma (CHL) and nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) are considered separate entities with different prognosis and treatment. However, morphologic features can be similar and immunohistochemical studies are essential in the distinction; thus, determination of additional biomarkers is of utmost importance. LRF/Pokemon is a proto-oncogene, an interacting partner co-expressed with BCL6 in germinal centers and highly expressed in diffuse large B-cell lymphoma and follicular lymphoma. Conversely, loss of the LRF gene in mouse hematopoietic stem cells results in complete block of early B cell development with concomitant Notch de-repression, indicating its critical role in B versus T cell fate decision at the hematopoietic stem cell stage. For the first time, we show that LRF/Pokemon is predominantly expressed in NLPHL cases as is BCL6 with low to absent NOTCH1 protein expression; while Hodgkin Reed-Sternberg (HRS) cells in CHL show low to absent BCL6 and LRF/Pokemon expression with higher NOTCH1 expression. We illustrate a potential functional interaction between LRF and BCL6 in NLPHL pathogenesis, and differential expression of LRF/Pokemon and NOTCH1 proteins in CHL thus showing differential expression, making for an additional diagnostic marker and therapeutic target.

  4. Canonical Notch signaling plays an instructive role in auditory supporting cell development

    PubMed Central

    Campbell, Dean P.; Chrysostomou, Elena; Doetzlhofer, Angelika

    2016-01-01

    The auditory sensory epithelium, composed of mechano-sensory hair cells (HCs) and highly specialized glial-like supporting cells (SCs), is critical for our ability to detect sound. SCs provide structural and functional support to HCs and play an essential role in cochlear development, homeostasis and repair. Despite their importance, however, surprisingly little is known about the molecular mechanisms guiding SC differentiation. Here, we provide evidence that in addition to its well-characterized inhibitory function, canonical Notch signaling plays a positive, instructive role in the differentiation of SCs. Using γ-secretase inhibitor DAPT to acutely block canonical Notch signaling, we identified a cohort of Notch-regulated SC-specific genes, with diverse functions in cell signaling, cell differentiation, neuronal innervation and synaptogenesis. We validated the newly identified Notch-regulated genes in vivo using genetic gain (Emx2Cre/+; Rosa26N1ICD/+) and loss-of-function approaches (Emx2Cre/+; Rosa26DnMAML1/+). Furthermore, we demonstrate that Notch over-activation in the differentiating murine cochlea (Emx2Cre/+; Rosa26N1ICD/+) actively promotes a SC-specific gene expression program. Finally, we show that outer SCs –so called Deiters’ cells are selectively lost by prolonged reduction (Emx2Cre/+; Rosa26DnMAML1/+/+) or abolishment of canonical Notch signaling (Fgfr3-iCreER; Rbpj−/Δ), indicating a critical role for Notch signaling in Deiters’ cell development. PMID:26786414

  5. Notch-mediated patterning and cell fate allocation of pancreatic progenitor cells

    PubMed Central

    Afelik, Solomon; Qu, Xiaoling; Hasrouni, Edy; Bukys, Michael A.; Deering, Tye; Nieuwoudt, Stephan; Rogers, William; MacDonald, Raymond J.; Jensen, Jan

    2012-01-01

    Early pancreatic morphogenesis is characterized by the transformation of an uncommitted pool of pancreatic progenitor cells into a branched pancreatic epithelium that consists of ‘tip’ and ‘trunk’ domains. These domains have distinct molecular signatures and differentiate into distinct pancreatic cell lineages. Cells at the branched tips of the epithelium develop into acinar cells, whereas cells in the trunk subcompartment differentiate into endocrine and duct cells. Recent genetic analyses have highlighted the role of key transcriptional regulators in the specification of these subcompartments. Here, we analyzed in mice the role of Notch signaling in the patterning of multipotent pancreatic progenitor cells through mosaic overexpression of a Notch signaling antagonist, dominant-negative mastermind-like 1, resulting in a mixture of wild-type and Notch-suppressed pancreatic progenitor cells. We find that attenuation of Notch signaling has pronounced patterning effects on multipotent pancreatic progenitor cells prior to terminal differentiation. Relative to the wild-type cells, the Notch-suppressed cells lose trunk marker genes and gain expression of tip marker genes. The Notch-suppressed cells subsequently differentiate into acinar cells, whereas duct and endocrine populations are formed predominantly from the wild-type cells. Mechanistically, these observations could be explained by a requirement of Notch for the expression of the trunk determination gene Nkx6.1. This was supported by the finding of direct binding of RBP-jκ to the Nkx6.1 proximal promoter. PMID:22461559

  6. 'Energy expenditure genes' or 'energy absorption genes': a new target for the treatment of obesity and Type II diabetes.

    PubMed

    Braud, Sandrine; Ciufolini, Marco; Harosh, Itzik

    2010-12-01

    Several hundred genes associated or linked to obesity have been described in the scientific literature. Whereas many of these genes are potential targets for the treatment of obesity and associated conditions, none of them have permitted the developement of an efficient drug therapy. As proposed by the 'thrifty genotype' theory, obesity genes may have conferred an evolutionary advantage in times of food shortage through efficient energy exploitation, while 'lean' or 'energy expenditure' genes may have become very rare during the same periods. It is therefore a challenge to identify 'energy expenditure genes' or 'energy absorption genes,' whose mutations or single nucleotide polymorphisms do result in reduced energy intake. We submit that such 'energy absorption' or 'energy expenditure' genes (crucial genes) are potential new targets for the treatment of obesity. These genes can be identified in rare genetic diseases that produce a lean, failure-to-thrive, energy malabsorption or starvation phenotype.

  7. Prognostic values of four Notch receptor mRNA expression in gastric cancer

    PubMed Central

    Wu, Xiaoyu; Liu, Wentao; Tang, Ding; Xiao, Haijuan; Wu, Zhenfeng; Chen, Che; Yao, Xuequan; Liu, Fukun; Li, Gang

    2016-01-01

    Notch ligands and receptors are frequently deregulated in several human malignancies including gastric cancer. The activation of Notch signaling has been reported to contribute to gastric carcinogenesis and progression. However, the prognostic roles of individual Notch receptors in gastric cancer patients remain elusive. In the current study, we accessed the prognostic roles of four Notch receptors, Notch 1–4, in gastric cancer patients through “The Kaplan-Meier plotter” (KM plotter) database, in which updated gene expression data and survival information include a total of 876 gastric cancer patients. All four Notch receptors’ high mRNA expression was found to be correlated to worsen overall survival (OS) for all gastric cancer patients followed for 20 years. We further accessed the prognostic roles of individual Notch receptors in different clinicopathological features using Lauren classification, pathological grades, clinical grades, HER2 status and different choices of treatments of gastric cancer patients. These results indicate that there are critical prognostic values of the four Notch receptors in gastric cancer. This information will be useful for better understanding of the heterogeneity and complexity in the molecular biology of gastric cancer and to develop tools to more accurately predict their prognosis. PMID:27363496

  8. Notch pathway regulates female germ cell meiosis progression and early oogenesis events in fetal mouse.

    PubMed

    Feng, Yan-Min; Liang, Gui-Jin; Pan, Bo; Qin, Xun-Si; Zhang, Xi-Feng; Chen, Chun-Lei; Li, Lan; Cheng, Shun-Feng; De Felici, Massimo; Shen, Wei

    2014-01-01

    A critical process of early oogenesis is the entry of mitotic oogonia into meiosis, a cell cycle switch regulated by a complex gene regulatory network. Although Notch pathway is involved in numerous important aspects of oogenesis in invertebrate species, whether it plays roles in early oogenesis events in mammals is unknown. Therefore, the rationale of the present study was to investigate the roles of Notch signaling in crucial processes of early oogenesis, such as meiosis entry and early oocyte growth. Notch receptors and ligands were localized in mouse embryonic female gonads and 2 Notch inhibitors, namely DAPT and L-685,458, were used to attenuate its signaling in an in vitro culture system of ovarian tissues from 12.5 days post coitum (dpc) fetus. The results demonstrated that the expression of Stra8, a master gene for germ cell meiosis, and its stimulation by retinoic acid (RA) were reduced after suppression of Notch signaling, and the other meiotic genes, Dazl, Dmc1, and Rec8, were abolished or markedly decreased. Furthermore, RNAi of Notch1 also markedly inhibited the expression of Stra8 and SCP3 in cultured female germ cells. The increased methylation status of CpG islands within the Stra8 promoter of the oocytes was observed in the presence of DAPT, indicating that Notch signaling is probably necessary for maintaining the epigenetic state of this gene in a way suitable for RA stimulation. Furthermore, in the presence of Notch inhibitors, progression of oocytes through meiosis I was markedly delayed. At later culture periods, the rate of oocyte growth was decreased, which impaired subsequent primordial follicle assembly in cultured ovarian tissues. Taken together, these results suggested new roles of the Notch signaling pathway in female germ cell meiosis progression and early oogenesis events in mammals.

  9. Proton myo-inositol cotransporter is a novel γ-secretase associated protein that regulates Aβ production without affecting Notch cleavage.

    PubMed

    Teranishi, Yasuhiro; Inoue, Mitsuhiro; Yamamoto, Natsuko Goto; Kihara, Takahiro; Wiehager, Birgitta; Ishikawa, Taizo; Winblad, Bengt; Schedin-Weiss, Sophia; Frykman, Susanne; Tjernberg, Lars O

    2015-09-01

    γ-Secretase is a transmembrane protease complex that is responsible for the processing of a multitude of type 1 transmembrane proteins, including the amyloid precursor protein and Notch. γ-Secretase processing of amyloid precursor protein results in the release of the amyloid β-peptide (Aβ), which is involved in the pathogenesis in Alzheimer's disease. Processing of Notch leads to the release of its intracellular domain, which is important for cell development. γ-Secretase associated proteins (GSAPs) could be of importance for substrate selection, and we have previously shown that affinity purification of γ-secretase in combination with mass spectrometry can be used for finding such proteins. In the present study, we used this methodology to screen for novel GSAPs from human brain, and studied their effect on Aβ production in a comprehensive gene knockdown approach. Silencing of probable phospholipid-transporting ATPase IIA, brain-derived neurotrophic factor/neurotrophin-3 growth factor receptor precursor and proton myo-inositol cotransporter (SLC2A13) showed a clear reduction of Aβ and these proteins were selected for further studies on Aβ production and Notch cleavage using small interfering RNA-mediated gene silencing, as well as an overexpression approach. Silencing of these reduced Aβ secretion in a small interfering RNA dose-dependent manner. Interestingly, SLC2A13 had a lower effect on Notch processing. Furthermore, overexpression of SLC2A13 increased Aβ40 generation. Finally, the interaction between γ-secretase and SLC2A13 was confirmed using immunoprecipitation and a proximity ligation assay. In summary, SLC2A13 was identified as a novel GSAP that regulates Aβ production without affecting Notch cleavage. We suggest that SLC2A13 could be a target for Aβ lowering therapy aimed at treating Alzheimer's disease. PMID:26094765

  10. Notch signaling change in pulmonary vascular remodeling in rats with pulmonary hypertension and its implication for therapeutic intervention.

    PubMed

    Qiao, Lina; Xie, Liang; Shi, Kun; Zhou, Tongfu; Hua, Yimin; Liu, Hanmin

    2012-01-01

    Pulmonary hypertension (PH) is a fatal disease that lacks an effective therapy. Notch signaling pathway plays a crucial role in the angiogenesis and vascular remodeling. However, its roles in vascular remodeling in PH have not been well studied. In the current study, using hypoxia-induced PH model in rat, we examined the expression of Notch and its downstream factors. Then, we used vessel strip culture system and γ-secretase inhibitor DAPT, a Notch signaling inhibitor to determine the effect of Notch signaling in vascular remodeling and its potential therapeutic value. Our results indicated that Notch 1-4 were detected in the lung tissue with variable levels in different cell types such as smooth muscle cells and endothelial cells of pulmonary artery, bronchia, and alveoli. In addition, following the PH induction, all of Notch1, Notch3, Notch4 receptor, and downstream factor, HERP1 in pulmonary arteries, mRNA expressions were increased with a peak at 1-2 weeks. Furthermore, the vessel wall thickness from rats with hypoxia treatment increased after cultured for 8 days, which could be decreased approximately 30% by DAPT, accompanied with significant increase of expression level of apoptotic factors (caspase-3 and Bax) and transformation of vascular smooth muscle cell (VSMC) phenotype from synthetic towards contractile. In conclusion, the current study suggested Notch pathway plays an important role in pulmonary vascular remodeling in PH and targeting Notch signaling pathway could be a valuable approach to design new therapy for PH. PMID:23251561

  11. Gene targeting, genome editing: from Dolly to editors.

    PubMed

    Tan, Wenfang; Proudfoot, Chris; Lillico, Simon G; Whitelaw, C Bruce A

    2016-06-01

    One of the most powerful strategies to investigate biology we have as scientists, is the ability to transfer genetic material in a controlled and deliberate manner between organisms. When applied to livestock, applications worthy of commercial venture can be devised. Although initial methods used to generate transgenic livestock resulted in random transgene insertion, the development of SCNT technology enabled homologous recombination gene targeting strategies to be used in livestock. Much has been accomplished using this approach. However, now we have the ability to change a specific base in the genome without leaving any other DNA mark, with no need for a transgene. With the advent of the genome editors this is now possible and like other significant technological leaps, the result is an even greater diversity of possible applications. Indeed, in merely 5 years, these 'molecular scissors' have enabled the production of more than 300 differently edited pigs, cattle, sheep and goats. The advent of genome editors has brought genetic engineering of livestock to a position where industry, the public and politicians are all eager to see real use of genetically engineered livestock to address societal needs. Since the first transgenic livestock reported just over three decades ago the field of livestock biotechnology has come a long way-but the most exciting period is just starting.

  12. Gene targeting, genome editing: from Dolly to editors.

    PubMed

    Tan, Wenfang; Proudfoot, Chris; Lillico, Simon G; Whitelaw, C Bruce A

    2016-06-01

    One of the most powerful strategies to investigate biology we have as scientists, is the ability to transfer genetic material in a controlled and deliberate manner between organisms. When applied to livestock, applications worthy of commercial venture can be devised. Although initial methods used to generate transgenic livestock resulted in random transgene insertion, the development of SCNT technology enabled homologous recombination gene targeting strategies to be used in livestock. Much has been accomplished using this approach. However, now we have the ability to change a specific base in the genome without leaving any other DNA mark, with no need for a transgene. With the advent of the genome editors this is now possible and like other significant technological leaps, the result is an even greater diversity of possible applications. Indeed, in merely 5 years, these 'molecular scissors' have enabled the production of more than 300 differently edited pigs, cattle, sheep and goats. The advent of genome editors has brought genetic engineering of livestock to a position where industry, the public and politicians are all eager to see real use of genetically engineered livestock to address societal needs. Since the first transgenic livestock reported just over three decades ago the field of livestock biotechnology has come a long way-but the most exciting period is just starting. PMID:26847670

  13. Using PCR to Target Misconceptions about Gene Expression †

    PubMed Central

    Wright, Leslie K.; Newman, Dina L.

    2013-01-01

    We present a PCR-based laboratory exercise that can be used with first- or second-year biology students to help overcome common misconceptions about gene expression. Biology students typically do not have a clear understanding of the difference between genes (DNA) and gene expression (mRNA/protein) and often believe that genes exist in an organism or cell only when they are expressed. This laboratory exercise allows students to carry out a PCR-based experiment designed to challenge their misunderstanding of the difference between genes and gene expression. Students first transform E. coli with an inducible GFP gene containing plasmid and observe induced and un-induced colonies. The following exercise creates cognitive dissonance when actual PCR results contradict their initial (incorrect) predictions of the presence of the GFP gene in transformed cells. Field testing of this laboratory exercise resulted in learning gains on both knowledge and application questions on concepts related to genes and gene expression. PMID:23858358

  14. Expression patterns of Notch1, Notch2, and Notch3 suggest multiple functional roles for the Notch-DSL signaling system during brain development.

    PubMed

    Irvin, D K; Zurcher, S D; Nguyen, T; Weinmaster, G; Kornblum, H I

    2001-07-23

    The Notch-DSL signaling system consists of multiple receptors and ligands, and plays many roles in development. The function of Notch receptors and ligands in mammalian brain, however, is poorly understood. In the current study, we examined the expression patterns for three receptors of this system, Notch1, 2, and 3, in late embryonic and postnatal rat brain by in situ hybridization. The three receptors have overlapping but different patterns of expression. Messenger RNA for all three proteins is found in postnatal central nervous system (CNS) germinal zones and, in early postnatal life, within numerous cells throughout the CNS. Within zones of cellular proliferation of the postnatal brain, Notch1 mRNA is found in both the subventricular and the ventricular germinal zones, whereas Notch2 and Notch3 mRNAs are more highly localized to the ventricular zones. Both Notch1 and Notch3 mRNAs are expressed along the inner aspect of the dentate gyrus, a site of adult neurogenesis. Notch2 mRNA is expressed in the external granule cell layer of the developing cerebellum. In several brain areas, Notch1 and Notch2 mRNAs are relatively concentrated in white matter, whereas Notch3 mRNA is not. Neurosphere cultures (which contain CNS stem cells), purified astrocyte cultures, and striatal neuron-enriched cultures express Notch1 mRNA. However, in these latter cultures, Notch1 mRNA is produced by nestin-containing cells, rather than by postmitotic neurons. Taken together, these results support multiple roles for Notch1, 2, and 3 receptor activation during CNS development, particularly during gliogenesis.

  15. Notch receptors in human choroid plexus tumors.

    PubMed

    Beschorner, R; Waidelich, J; Trautmann, K; Psaras, T; Schittenhelm, J

    2013-08-01

    Notch signaling plays a role in development and formation of the normal choroid plexus (nCP), and in formation of various tumors in humans. Activation of Notch3 has been reported to promote tumor growth in invasive gliomas and to initiate formation of choroid plexus tumors (CPT) in mice. We investigated the expression of all currently known Notch receptors (Notch 1-4) in 55 samples of nCP and 88 CPT, including 61 choroid plexus papillomas (CPP), 22 atypical CPP and 5 choroid plexus carcinomas by immunohistochemistry. Notch expression was semiquantitatively evaluated separately for membranous/cytoplasmic and for nuclear staining. In addition, we examined Her2 expression (EGFR2, Her2/neu, ErbB2, CD340) because of its functional link to Notch signaling. All samples were negative for Notch3. Membranous/cytoplasmic expression of Notch1 (p<0.0001) and Notch4 (p=0.046) was significantly higher, whereas Notch2 expression was significantly lower (p<0.0001) in nCP compared to CPT. Nuclear expression of Notch1, -2 and -4 was significantly higher in CPT compared to nCP (p<0.0001 each). Expression of Notch2 and Notch4 showed a shift from a prevailing membranous/cytoplasmic expression in nCP to a predominant nuclear expression in CPT. Her2 was weakly expressed in 42/84 CPT but only in 2/53 nCP (p=0.0001) and positively correlated with nuclear expression of Notch1, -2 and 4 in CPT. In summary, a shift between membranous/cytoplasmic (non-canonical signaling pathway) and nuclear expression (canonical signaling pathway) of Notch1, -2 and -4 and upregulation of Her2 indicate neoplastic transformation in human CP and may reveal new therapeutic approaches.

  16. Aspartate mutations in presenilin and gamma-secretase inhibitors both impair notch1 proteolysis and nuclear translocation with relative preservation of notch1 signaling.

    PubMed

    Berezovska, O; Jack, C; McLean, P; Aster, J C; Hicks, C; Xia, W; Wolfe, M S; Kimberly, W T; Weinmaster, G; Selkoe, D J; Hyman, B T

    2000-08-01

    It has been hypothesized that a presenilin 1 (PS1)-related enzymatic activity is responsible for proteolytic cleavage of the C-terminal intracellular protein of Notch1, in addition to its role in beta-amyloid protein (Abeta) formation from the amyloid precursor protein (APP). We developed an assay to monitor ligand-induced Notch1 proteolysis and nuclear translocation in individual cells : Treatment of full-length Notch1-enhanced green fluorescent protein-transfected Chinese hamster ovary (CHO) cells with a soluble preclustered form of the physiologic ligand Delta leads to rapid accumulation of the C terminus of Notch1 in the nucleus and to transcriptional activation of a C-promoter binding factor 1 (CBF1) reporter construct. Nuclear translocation was blocked by cotransfection with Notch's physiologic inhibitor Numb. Using this assay, we now confirm and extend the observation that PS1 is involved in Notch1 nuclear translocation and signaling in mammalian cells. We demonstrate that the D257A and the D385A PS1 mutations, which had been shown previously to block APP gamma-secretase activity, also prevent Notch1 cleavage and translocation to the nucleus but do not alter Notch1 trafficking to the cell surface. We also show that two APP gamma-secretase inhibitors block Notch1 nuclear translocation with an IC(50) similar to that reported for APP gamma-secretase. Notch1 signaling, assessed by measuring the activity of CBF1, a downstream transcription factor, was impaired but not abolished by the PS1 aspartate mutations or gamma-secretase inhibitors. Our results support the hypotheses that (a) PS1-dependent APP gamma-secretase-like enzymatic activity is critical for both APP and Notch processing and (b) the Notch1 signaling pathway remains partially activated even when Notch1 proteolytic processing and nuclear translocation are markedly inhibited. The latter is an important finding from the perspective of therapeutic treatment of Alzheimer's disease by targeting gamma

  17. Reiterated Targeting Peptides on the Nanoparticle Surface Significantly Promote Targeted Vascular Endothelial Growth Factor Gene Delivery to Stem Cells.

    PubMed

    Wang, Dong-Dong; Yang, Mingying; Zhu, Ye; Mao, Chuanbin

    2015-12-14

    Nonviral gene delivery vectors hold great promise for gene therapy due to the safety concerns with viral vectors. However, the application of nonviral vectors is hindered by their low transfection efficiency. Herein, in order to tackle this challenge, we developed a nonviral vector integrating lipids, sleeping beauty transposon system and 8-mer stem cell targeting peptides for safe and efficient gene delivery to hard-to-transfect mesenchymal stem cells (MSCs). The 8-mer MSC-targeting peptides, when synthetically reiterated in three folds and chemically presented on the surface, significantly promoted the resultant lipid-based nanoparticles (LBNs) to deliver VEGF gene into MSCs with a high transfection efficiency (∼52%) and long-lasting gene expression (for longer than 170 h) when compared to nonreiterated peptides. However, the reiterated stem cell targeting peptides do not enable the highly efficient gene transfer to other control cells. This work suggests that the surface presentation of the reiterated stem cell-targeting peptides on the nonviral vectors is a promising method for improving the efficiency of cell-specific nonviral gene transfection in stem cells. PMID:26588028

  18. Network analysis of microRNAs, transcription factors, target genes and host genes in nasopharyngeal carcinoma

    PubMed Central

    WANG, HAO; XU, ZHIWEN; MA, MENGYAO; WANG, NING; WANG, KUNHAO

    2016-01-01

    Numerous studies on the morbidity of nasopharyngeal carcinoma (NPC) have identified several genes, microRNAs (miRNAs or miRs) and transcription factors (TFs) that influence the pathogenesis of NPC. However, summarizing all the regulatory networks involved in NPC is challenging. In the present study, the genes, miRNAs and TFs involved in NPC were considered as the nodes of the so-called regulatory network, and the associations between them were investigated. To clearly represent these associations, three regulatory networks were built seperately, namely, the differentially expressed network, the associated network and the global network. The differentially expressed network is the most important one of these three networks, since its nodes are differentially expressed genes whose mutations may lead to the development of NPC. Therefore, by modifying the aberrant expression of those genes that are differentially expressed in this network, their dysregulation may be corrected and the tumorigenesis of NPC may thus be prevented. Analysis of the aforementioned three networks highlighted the importance of certain pathways, such as self-adaptation pathways, in the development of NPC. For example, cyclin D1 (CCND1) was observed to regulate Homo sapiens-miR-20a, which in turn targeted CCND1. The present study conducted a systematic analysis of the pathogenesis of NPC through the three aforementioned regulatory networks, and provided a theoretical model for biologists. Future studies are required to evaluate the influence of the highlighted pathways in NPC. PMID:27313701

  19. Notch signaling in cerebrovascular diseases (Review)

    PubMed Central

    Cai, Zhiyou; Zhao, Bin; Deng, Yanqing; Shangguan, Shouqin; Zhou, Faming; Zhou, Wenqing; Li, Xiaoli; Li, Yanfeng; Chen, Guanghui

    2016-01-01

    The Notch signaling pathway is a crucial regulator of numerous fundamental cellular processes. Increasing evidence suggests that Notch signaling is involved in inflammation and oxidative stress, and thus in the progress of cerebrovascular diseases. In addition, Notch signaling in cerebrovascular diseases is associated with apoptosis, angiogenesis and the function of blood-brain barrier. Despite the contradictory results obtained to date as to whether Notch signaling is harmful or beneficial, the regulation of Notch signaling may provide a novel strategy for the treatment of cerebrovascular diseases. PMID:27574001

  20. Zeb2 recruits HDAC-NuRD to inhibit Notch and controls Schwann cell differentiation and remyelination.

    PubMed

    Wu, Lai Man Natalie; Wang, Jincheng; Conidi, Andrea; Zhao, Chuntao; Wang, Haibo; Ford, Zachary; Zhang, Liguo; Zweier, Christiane; Ayee, Brian G; Maurel, Patrice; Zwijsen, An; Chan, Jonah R; Jankowski, Michael P; Huylebroeck, Danny; Lu, Q Richard

    2016-08-01

    The mechanisms that coordinate and balance a complex network of opposing regulators to control Schwann cell (SC) differentiation remain elusive. Here we demonstrate that zinc-finger E-box-binding homeobox 2 (Zeb2, also called Sip1) transcription factor is a critical intrinsic timer that controls the onset of SC differentiation by recruiting histone deacetylases HDAC 1 and 2 (HDAC1/2) and nucleosome remodeling and deacetylase complex (NuRD) co-repressor complexes in mice. Zeb2 deletion arrests SCs at an undifferentiated state during peripheral nerve development and inhibits remyelination after injury. Zeb2 antagonizes inhibitory effectors including Notch and Sox2. Importantly, genome-wide transcriptome analysis reveals a Zeb2 target gene encoding the Notch effector Hey2 as a potent inhibitor for Schwann cell differentiation. Strikingly, a genetic Zeb2 variant associated with Mowat-Wilson syndrome disrupts the interaction with HDAC1/2-NuRD and abolishes Zeb2 activity for SC differentiation. Therefore, Zeb2 controls SC maturation by recruiting HDAC1/2-NuRD complexes and inhibiting a Notch-Hey2 signaling axis, pointing to the critical role of HDAC1/2-NuRD activity in peripheral neuropathies caused by ZEB2 mutations. PMID:27294509

  1. Notch1 Pathway Activity Determines the Regulatory Role of Cancer-Associated Fibroblasts in Melanoma Growth and Invasion

    PubMed Central

    Shao, Hongwei; Kong, Ranran; Ferrari, Massimiliano L.; Radtke, Freddy; Capobianco, Anthony J.; Liu, Zhao-Jun

    2015-01-01

    Cancer-associated fibroblasts (CAF) play a crucial role in regulating cancer progression, yet the molecular determinant that governs the tumor regulatory role of CAF remains unknown. Using a mouse melanoma model in which exogenous melanoma cells were grafted on the skin of two lines of mice where the genetic activation or inactivation of Notch1 signaling specifically occurs in natural host stromal fibroblasts, we demonstrated that Notch1 pathway activity could determine the tumor-promoting or tumor-suppressing phenotype in CAF. CAF carrying elevated Notch1 activity significantly inhibited melanoma growth and invasion, while those with a null Notch1 promoted melanoma invasion. These findings identify the Notch1 pathway as a molecular determinant that controls the regulatory role of CAF in melanoma skin growth and invasion, unveiling Notch1 signaling as a potential therapeutic target for melanoma and potentially other solid tumors. PMID:26562315

  2. Response to Nodal morphogen gradient is determined by the kinetics of target gene induction

    PubMed Central

    Dubrulle, Julien; Jordan, Benjamin M; Akhmetova, Laila; Farrell, Jeffrey A; Kim, Seok-Hyung; Solnica-Krezel, Lilianna; Schier, Alexander F

    2015-01-01

    Morphogen gradients expose cells to different signal concentrations and induce target genes with different ranges of expression. To determine how the Nodal morphogen gradient induces distinct gene expression patterns during zebrafish embryogenesis, we measured the activation dynamics of the signal transducer Smad2 and the expression kinetics of long- and short-range target genes. We found that threshold models based on ligand concentration are insufficient to predict the response of target genes. Instead, morphogen interpretation is shaped by the kinetics of target gene induction: the higher the rate of transcription and the earlier the onset of induction, the greater the spatial range of expression. Thus, the timing and magnitude of target gene expression can be used to modulate the range of expression and diversify the response to morphogen gradients. DOI: http://dx.doi.org/10.7554/eLife.05042.001 PMID:25869585

  3. Advances in the Development of Gene-Targeting Vectors to Increase the Efficiency of Genetic Modification.

    PubMed

    Saito, Shinta; Adachi, Noritaka

    2016-01-01

    Gene targeting via homologous recombination, albeit highly inefficient in human cells, is considered a powerful tool for analyzing gene functions. Despite recent progress in the application of artificial nucleases for genome editing, safety issues remain a concern, particularly when genetic modification is used for therapeutic purposes. Therefore, the development of gene-targeting vectors is necessary for safe and sophisticated genetic modification. In this paper, we describe the effect of vector structure on random integration, which is a major obstacle in efficient gene targeting. In addition, we focus on the features of exon-trapping-type gene-targeting vectors, and discuss a novel strategy for negative selection to enhance gene targeting in human cells.

  4. Specific genetic modifications of domestic animals by gene targeting and animal cloning.

    PubMed

    Wang, Bin; Zhou, Jiangfeng

    2003-11-13

    The technology of gene targeting through homologous recombination has been extremely useful for elucidating gene functions in mice. The application of this technology was thought impossible in the large livestock species until the successful creation of the first mammalian clone "Dolly" the sheep. The combination of the technologies for gene targeting of somatic cells with those of animal cloning made it possible to introduce specific genetic mutations into domestic animals. In this review, the principles of gene targeting in somatic cells and the challenges of nuclear transfer using gene-targeted cells are discussed. The relevance of gene targeting in domestic animals for applications in bio-medicine and agriculture are also examined. PMID:14614774

  5. Targeted gene deletion of Leishmania major genes encoding developmental stage-specific leishmanolysin (GP63).

    PubMed

    Joshi, P B; Sacks, D L; Modi, G; McMaster, W R

    1998-02-01

    The major surface glycoprotein of Leishmania major is a zinc metalloproteinase of 63 kDa referred to as leishmanolysin or GP63, which is encoded by a family of seven genes. Targeted gene replacement was used to delete gp63 genes 1-6 encoding the highly expressed promastigote and constitutively expressed GP63. In the L. major homozygous mutants deficient in gp63 genes 1-6, there was no expression of GP63 as detected by reverse transcription-polymerase chain reaction (RT-PCR) or fluorescent staining in promastigotes from the procyclic stage (logarithmic growth phase). The remaining L. major gP63 gene 7 was shown to be developmentally regulated, as it was expressed exclusively in infectious metacyclic stage (late stationary growth phase) promastigotes and in lesion amastigotes. The gp63 genes 1-6-deficient mutants showed increased sensitivity to complement-mediated lysis. The sensitivity to lysis was greater in procyclics than in metacyclics when compared with the equivalent wild-type stages. Increased resistance of the mutant metacyclic promastigotes correlated with the expression of gp63 gene 7 and was restored to the same levels as wild-type promastigotes by transfection with gp63 gene 1. Thus, expression of GP63 is clearly involved in conferring resistance to complement-mediated lysis. The L. major GP63 1-6 mutants were capable of infecting mouse macrophages and differentiating into amastigotes. Similar levels of infection and subsequent intracellular survival were observed when mouse macrophages were infected in vitro with wild type, GP63 1-6 mutants and mutants transfected with gp63 gene 1. The GP63 1-6 mutants were capable of lesion formation in BALB/c mice and, thus, gp63 genes 1-6 do not play a role in the survival of the parasite within mouse macrophages. The role of gp63 genes 1-6 in parasite development within the sandfly vector was studied. GP63 1-6 mutants grew normally in the blood-engorged midgut of both Phlebotomus argentipes and P. papatasi However

  6. MiR-34a Promotes Osteogenic Differentiation of Human Adipose-Derived Stem Cells via the RBP2/NOTCH1/CYCLIN D1 Coregulatory Network.

    PubMed

    Fan, Cong; Jia, Lingfei; Zheng, Yunfei; Jin, Chanyuan; Liu, Yunsong; Liu, Hao; Zhou, Yongsheng

    2016-08-01

    MiR-34a was demonstrated to be upregulated during the osteogenic differentiation of human adipose-derived stem cells (hASCs). Overexpression of miR-34a significantly increased alkaline phosphatase activity, mineralization capacity, and the expression of osteogenesis-associated genes in hASCs in vitro. Enhanced heterotopic bone formation in vivo was also observed upon overexpression of miR-34a in hASCs. Mechanistic investigations revealed that miR-34a inhibited the expression of retinoblastoma binding protein 2 (RBP2) and reduced the luciferase activity of reporter gene construct comprising putative miR-34a binding sites in the 3' UTR of RBP2. Moreover, miR-34a downregulated the expression of NOTCH1 and CYCLIN D1 and upregulated the expression of RUNX2 by targeting RBP2, NOTCH1, and CYCLIN D1. Taken together, our results suggested that miR-34a promotes the osteogenic differentiation of hASCs via the RBP2/NOTCH1/CYCLIN D1 coregulatory network, indicating that miR-34a-targeted therapy could be a valuable approach to promote bone regeneration. PMID:27453008

  7. Magnetic nanoparticles for targeted therapeutic gene delivery and magnetic-inducing heating on hepatoma

    NASA Astrophysics Data System (ADS)

    Yuan, Chenyan; An, Yanli; Zhang, Jia; Li, Hongbo; Zhang, Hao; Wang, Ling; Zhang, Dongsheng

    2014-08-01

    Gene therapy holds great promise for treating cancers, but their clinical applications are being hampered due to uncontrolled gene delivery and expression. To develop a targeted, safe and efficient tumor therapy system, we constructed a tissue-specific suicide gene delivery system by using magnetic nanoparticles (MNPs) as carriers for the combination of gene therapy and hyperthermia on hepatoma. The suicide gene was hepatoma-targeted and hypoxia-enhanced, and the MNPs possessed the ability to elevate temperature to the effective range for tumor hyperthermia as imposed on an alternating magnetic field (AMF). The tumoricidal effects of targeted gene therapy associated with hyperthermia were evaluated in vitro and in vivo. The experiment demonstrated that hyperthermia combined with a targeted gene therapy system proffer an effective tool for tumor therapy with high selectivity and the synergistic effect of hepatoma suppression.

  8. Transcriptome Analysis of Targeted Mouse Mutations Reveals the Topography of Local Changes in Gene Expression

    PubMed Central

    Adkisson, Michael; Nava, A. J.; Kirov, Julia V.; Cipollone, Andreanna; Willis, Brandon; Rapp, Jared; de Jong, Pieter J.; Lloyd, Kent C.

    2016-01-01

    The unintended consequences of gene targeting in mouse models have not been thoroughly studied and a more systematic analysis is needed to understand the frequency and characteristics of off-target effects. Using RNA-seq, we evaluated targeted and neighboring gene expression in tissues from 44 homozygous mutants compared with C57BL/6N control mice. Two allele types were evaluated: 15 targeted trap mutations (TRAP); and 29 deletion alleles (DEL), usually a deletion between the translational start and the 3’ UTR. Both targeting strategies insert a bacterial beta-galactosidase reporter (LacZ) and a neomycin resistance selection cassette. Evaluating transcription of genes in +/- 500 kb of flanking DNA around the targeted gene, we found up-regulated genes more frequently around DEL compared with TRAP alleles, however the frequency of alleles with local down-regulated genes flanking DEL and TRAP targets was similar. Down-regulated genes around both DEL and TRAP targets were found at a higher frequency than expected from a genome-wide survey. However, only around DEL targets were up-regulated genes found with a significantly higher frequency compared with genome-wide sampling. Transcriptome analysis confirms targeting in 97% of DEL alleles, but in only 47% of TRAP alleles probably due to non-functional splice variants, and some splicing around the gene trap. Local effects on gene expression are likely due to a number of factors including compensatory regulation, loss or disruption of intragenic regulatory elements, the exogenous promoter in the neo selection cassette, removal of insulating DNA in the DEL mutants, and local silencing due to disruption of normal chromatin organization or presence of exogenous DNA. An understanding of local position effects is important for understanding and interpreting any phenotype attributed to targeted gene mutations, or to spontaneous indels. PMID:26839965

  9. Anabolic actions of Notch on mature bone

    PubMed Central

    Liu, Peng; Ping, Yilin; Ma, Meng; Zhang, Demao; Liu, Connie; Zaidi, Samir; Gao, Song; Ji, Yaoting; Lou, Feng; Yu, Fanyuan; Lu, Ping; Stachnik, Agnes; Bai, Mingru; Wei, Chengguo; Zhang, Liaoran; Wang, Ke; Chen, Rong; New, Maria I.; Rowe, David W.; Yuen, Tony; Sun, Li; Zaidi, Mone

    2016-01-01

    Notch controls skeletogenesis, but its role in the remodeling of adult bone remains conflicting. In mature mice, the skeleton can become osteopenic or osteosclerotic depending on the time point at which Notch is activated or inactivated. Using adult EGFP reporter mice, we find that Notch expression is localized to osteocytes embedded within bone matrix. Conditional activation of Notch signaling in osteocytes triggers profound bone formation, mainly due to increased mineralization, which rescues both age-associated and ovariectomy-induced bone loss and promotes bone healing following osteotomy. In parallel, mice rendered haploinsufficient in γ-secretase presenilin-1 (Psen1), which inhibits downstream Notch activation, display almost-absent terminal osteoblast differentiation. Consistent with this finding, pharmacologic or genetic disruption of Notch or its ligand Jagged1 inhibits mineralization. We suggest that stimulation of Notch signaling in osteocytes initiates a profound, therapeutically relevant, anabolic response. PMID:27036007

  10. Feasibility of a bilateral 4000–6000 Hz notch as a phenotype for genetic association analysis

    PubMed Central

    Phillips, Susan L.; Richter, Scott J.; Teglas, Sandra L.; Bhatt, Ishan S.; Morehouse, Robin C.; Hauser, Elizabeth R.; Henrich, Vincent C.

    2016-01-01

    Objective Noise-induced hearing loss (NIHL) is a worldwide health problem and a growing concern among young people. Although some people appear to be more susceptible to NIHL, genetic association studies lack a specific phenotype. We tested the feasibility of a bilateral 4000–6000 Hz audiometric notch as a phenotype for identifying genetic contributions to hearing loss in young adults. Design A case-control-control study was conducted to examine selected SNPs in 52 genes previously associated with hearing loss and/or expressed in the cochlea. A notch was defined as a minimum of a 15-dB drop at 4000–6000 Hz from the previous best threshold with a 5-dB ‘recovery’ at 8000 Hz. Study sample Participants were 252 individuals of European descent taken from a population of 640 young adults who are students of classical music. Participants were grouped as No-notch (NN), Unilateral Notch (UN), or Bilateral Notch (BN). Results The strongest evidence of a genetic association with the 4000–6000 Hz notch was a nonsynonymous SNP variant in the ESRR? gene (rs61742642:C>T, P386S). Carriers of the minor allele accounted for 26% of all bilateral losses. Conclusion This study indicates that the 4000–6000 Hz bilateral notch is a feasible phenotype for identifying genetic susceptibility to hearing loss. PMID:25938503

  11. A gene locus for targeted ectopic gene integration in Zymoseptoria tritici☆

    PubMed Central

    Kilaru, S.; Schuster, M.; Latz, M.; Das Gupta, S.; Steinberg, N.; Fones, H.; Gurr, S.J.; Talbot, N.J.; Steinberg, G.

    2015-01-01

    Understanding the cellular organization and biology of fungal pathogens requires accurate methods for genomic integration of mutant alleles or fluorescent fusion-protein constructs. In Zymoseptoria tritici, this can be achieved by integrating of plasmid DNA randomly into the genome of this wheat pathogen. However, untargeted ectopic integration carries the risk of unwanted side effects, such as altered gene expression, due to targeting regulatory elements, or gene disruption following integration into protein-coding regions of the genome. Here, we establish the succinate dehydrogenase (sdi1) locus as a single “soft-landing” site for targeted ectopic integration of genetic constructs by using a carboxin-resistant sdi1R allele, carrying the point-mutation H267L. We use various green and red fluorescent fusion constructs and show that 97% of all transformants integrate correctly into the sdi1 locus as single copies. We also demonstrate that such integration does not affect the pathogenicity of Z. tritici, and thus the sdi1 locus is a useful tool for virulence analysis in genetically modified Z. tritici strains. Furthermore, we have developed a vector which facilitates yeast recombination cloning and thus allows assembly of multiple overlapping DNA fragments in a single cloning step for high throughput vector and strain generation. PMID:26092798

  12. Direct regulation of interleukin-6 expression by Notch signaling in macrophages.

    PubMed

    Wongchana, Wipawee; Palaga, Tanapat

    2012-03-01

    Interleukin-6 (IL-6) is a pleiotropic, pro-inflammatory cytokine produced by various types of cells, including macrophages. Within the IL-6 gene promoter region, the signature binding motif of CBF1/Su(H)/Lag-1 (CSL), a key DNA-binding protein in the Notch signaling pathway, was identified and found to overlap with a consensus nuclear factor (NF)-κB-binding site. Notch signaling is highly conserved and is involved in the regulation of biological functions in immune cells. In this study, we investigated the role of Notch signaling in the regulation of the IL-6 transcript in murine macrophages. The upregulation of Notch1 protein levels and the appearance of cleaved Notch1 (Val1744) correlated well with the increased IL-6 mRNA expression levels in murine primary bone marrow-derived macrophages (BMMφ) after activation by lipopolysaccharide (LPS) together with interferon-gamma (IFN-γ). Treatment of BMMφ with the γ-secretase inhibitor IL-CHO to suppress the transduction of Notch signaling resulted in a partial decrease in the level of IL-6 mRNA and the amount of IL-6 protein produced. In contrast, the overexpression of a constitutively activated intracellular Notch1 protein (N(IC)) in the RAW264.7 macrophage-like cell line resulted in significantly higher IL-6 transcript expression levels than in cells transfected with the empty vector control. The NF-κB inhibitor completely abrogated IL-6 mRNA expression induced by the overexpression of N(IC). Chromatin immunoprecipitation (ChIP) using an anti-Notch1 antibody demonstrated that Notch1 is associated with the IL-6 promoter in RAW264.7 cells activated by LPS/IFN-γ but not in unstimulated cells. Taken together, these results strongly suggest that Notch1 positively regulates IL-6 expression via NF-κB in activated macrophages.

  13. Direct regulation of interleukin-6 expression by Notch signaling in macrophages

    PubMed Central

    Wongchana, Wipawee; Palaga, Tanapat

    2012-01-01

    Interleukin-6 (IL-6) is a pleiotropic, pro-inflammatory cytokine produced by various types of cells, including macrophages. Within the IL-6 gene promoter region, the signature binding motif of CBF1/Su(H)/Lag-1 (CSL), a key DNA-binding protein in the Notch signaling pathway, was identified and found to overlap with a consensus nuclear factor (NF)-κB-binding site. Notch signaling is highly conserved and is involved in the regulation of biological functions in immune cells. In this study, we investigated the role of Notch signaling in the regulation of the IL-6 transcript in murine macrophages. The upregulation of Notch1 protein levels and the appearance of cleaved Notch1 (Val1744) correlated well with the increased IL-6 mRNA expression levels in murine primary bone marrow-derived macrophages (BMMφ) after activation by lipopolysaccharide (LPS) together with interferon-gamma (IFN-γ). Treatment of BMMφ with the γ-secretase inhibitor IL-CHO to suppress the transduction of Notch signaling resulted in a partial decrease in the level of IL-6 mRNA and the amount of IL-6 protein produced. In contrast, the overexpression of a constitutively activated intracellular Notch1 protein (NIC) in the RAW264.7 macrophage-like cell line resulted in significantly higher IL-6 transcript expression levels than in cells transfected with the empty vector control. The NF-κB inhibitor completely abrogated IL-6 mRNA expression induced by the overexpression of NIC. Chromatin immunoprecipitation (ChIP) using an anti-Notch1 antibody demonstrated that Notch1 is associated with the IL-6 promoter in RAW264.7 cells activated by LPS/IFN-γ but not in unstimulated cells. Taken together, these results strongly suggest that Notch1 positively regulates IL-6 expression via NF-κB in activated macrophages. PMID:21983868

  14. Pleiotropic roles of Notch signaling in normal, malignant, and developmental hematopoiesis in the human

    PubMed Central

    Kushwah, Rahul; Guezguez, Borhane; Lee, Jung Bok; Hopkins, Claudia I; Bhatia, Mickie

    2014-01-01

    The Notch signaling pathway is evolutionarily conserved across species and plays an important role in regulating cell differentiation, proliferation, and survival. It has been implicated in several different hematopoietic processes including early hematopoietic development as well as adult hematological malignancies in humans. This review focuses on recent developments in understanding the role of Notch signaling in the human hematopoietic system with an emphasis on hematopoietic initiation from human pluripotent stem cells and regulation within the bone marrow. Based on recent insights, we summarize potential strategies for treatment of human hematological malignancies toward the concept of targeting Notch signaling for fate regulation. PMID:25252682

  15. Comparison of quantitative PCR assays for Escherichia coli targeting ribosomal RNA and single copy genes

    EPA Science Inventory

    Aims: Compare specificity and sensitivity of quantitative PCR (qPCR) assays targeting single and multi-copy gene regions of Escherichia coli. Methods and Results: A previously reported assay targeting the uidA gene (uidA405) was used as the basis for comparing the taxono...

  16. Control of target gene specificity during metamorphosis by the steroid response gene E93.

    PubMed

    Mou, Xiaochun; Duncan, Dianne M; Baehrecke, Eric H; Duncan, Ian

    2012-02-21

    Hormonal control of sexual maturation is a common feature in animal development. A particularly dramatic example is the metamorphosis of insects, in which pulses of the steroid hormone ecdysone drive the wholesale transformation of the larva into an adult. The mechanisms responsible for this transformation are not well understood. Work in Drosophila indicates that the larval and adult forms are patterned by the same underlying sets of developmental regulators, but it is not understood how the same regulators pattern two distinct forms. Recent studies indicate that this ability is facilitated by a global change in the responsiveness of target genes during metamorphosis. Here we show that this shift is controlled in part by the ecdysone-induced transcription factor E93. Although long considered a dedicated regulator of larval cell death, we find that E93 is expressed widely in adult cells at the pupal stage and is required for many patterning processes at this time. To understand the role of E93 in adult patterning, we focused on a simple E93-dependent process, the induction of the Dll gene within bract cells of the pupal leg by EGF receptor signaling. In this system, we show that E93 functions to cause Dll to become responsive to EGF receptor signaling. We demonstrate that E93 is both necessary and sufficient for directing this switch. E93 likely controls the responsiveness of many other target genes because it is required broadly for patterning during metamorphosis. The wide conservation of E93 orthologs suggests that similar mechanisms control life-cycle transitions in other organisms, including vertebrates.

  17. Control of target gene specificity during metamorphosis by the steroid response gene E93.

    PubMed

    Mou, Xiaochun; Duncan, Dianne M; Baehrecke, Eric H; Duncan, Ian

    2012-02-21

    Hormonal control of sexual maturation is a common feature in animal development. A particularly dramatic example is the metamorphosis of insects, in which pulses of the steroid hormone ecdysone drive the wholesale transformation of the larva into an adult. The mechanisms responsible for this transformation are not well understood. Work in Drosophila indicates that the larval and adult forms are patterned by the same underlying sets of developmental regulators, but it is not understood how the same regulators pattern two distinct forms. Recent studies indicate that this ability is facilitated by a global change in the responsiveness of target genes during metamorphosis. Here we show that this shift is controlled in part by the ecdysone-induced transcription factor E93. Although long considered a dedicated regulator of larval cell death, we find that E93 is expressed widely in adult cells at the pupal stage and is required for many patterning processes at this time. To understand the role of E93 in adult patterning, we focused on a simple E93-dependent process, the induction of the Dll gene within bract cells of the pupal leg by EGF receptor signaling. In this system, we show that E93 functions to cause Dll to become responsive to EGF receptor signaling. We demonstrate that E93 is both necessary and sufficient for directing this switch. E93 likely controls the responsiveness of many other target genes because it is required broadly for patterning during metamorphosis. The wide conservation of E93 orthologs suggests that similar mechanisms control life-cycle transitions in other organisms, including vertebrates. PMID:22308414

  18. Identification of the human ApoAV gene as a novel ROR{alpha} target gene

    SciTech Connect

    Lind, Ulrika; Nilsson, Tina; McPheat, Jane; Stroemstedt, Per-Erik; Bamberg, Krister; Balendran, Clare; Kang, Daiwu . E-mail: Daiwu.Kang@astrazeneca.com

    2005-04-29

    Retinoic acid receptor-related orphan receptor-{alpha} (ROR{alpha}) (NR1F1) is an orphan nuclear receptor with a potential role in metabolism. Previous studies have shown that ROR{alpha} regulates transcription of the murine Apolipoprotein AI gene and human Apolipoprotein CIII genes. In the present study, we present evidence that ROR{alpha} also induces transcription of the human Apolipoprotein AV gene, a recently identified apolipoprotein associated with triglyceride levels. Adenovirus-mediated overexpression of ROR{alpha} increased the endogenous expression of ApoAV in HepG2 cells and ROR{alpha} also enhanced the activity of an ApoAV promoter construct in transiently transfected HepG2 cells. Deletion and mutation studies identified three AGGTCA motifs in the ApoAV promoter that mediate ROR{alpha} transactivation, one of which overlaps with a previously identified binding site for PPAR{alpha}. Together, these results suggest a novel mechanism whereby ROR{alpha} modulates lipid metabolism and implies ROR{alpha} as a potential target for the treatment of dyslipidemia and atherosclerosis.

  19. Seamless Genome Editing in Rice via Gene Targeting and Precise Marker Elimination.

    PubMed

    Nishizawa-Yokoi, Ayako; Saika, Hiroaki; Toki, Seiichi

    2016-01-01

    Positive-negative selection using hygromycin phosphotransferase (hpt) and diphtheria toxin A-fragment (DT-A) as positive and negative selection markers, respectively, allows enrichment of cells harboring target genes modified via gene targeting (GT). We have developed a successful GT system employing positive-negative selection and subsequent precise marker excision via the piggyBac transposon derived from the cabbage looper moth to introduce desired modifications into target genes in the rice genome. This approach could be applied to the precision genome editing of almost all endogenous genes throughout the genome, at least in rice. PMID:27557691

  20. Applications of CRISPR/Cas9 technology for targeted mutagenesis, gene replacement and stacking of genes in higher plants.

    PubMed

    Luo, Ming; Gilbert, Brian; Ayliffe, Michael

    2016-07-01

    Mutagenesis continues to play an essential role for understanding plant gene function and, in some instances, provides an opportunity for plant improvement. The development of gene editing technologies such as TALENs and zinc fingers has revolutionised the targeted mutation specificity that can now be achieved. The CRISPR/Cas9 system is the most recent addition to gene editing technologies and arguably the simplest requiring only two components; a small guide RNA molecule (sgRNA) and Cas9 endonuclease protein which complex to recognise and cleave a specific 20 bp target site present in a genome. Target specificity is determined by complementary base pairing between the sgRNA and target site sequence enabling highly specific, targeted mutation to be readily engineered. Upon target site cleavage, error-prone endogenous repair mechanisms produce small insertion/deletions at the target site usually resulting in loss of gene function. CRISPR/Cas9 gene editing has been rapidly adopted in plants and successfully undertaken in numerous species including major crop species. Its applications are not restricted to mutagenesis and target site cleavage can be exploited to promote sequence insertion or replacement by recombination. The multiple applications of this technology in plants are described. PMID:27146973

  1. Applications of CRISPR/Cas9 technology for targeted mutagenesis, gene replacement and stacking of genes in higher plants.

    PubMed

    Luo, Ming; Gilbert, Brian; Ayliffe, Michael

    2016-07-01

    Mutagenesis continues to play an essential role for understanding plant gene function and, in some instances, provides an opportunity for plant improvement. The development of gene editing technologies such as TALENs and zinc fingers has revolutionised the targeted mutation specificity that can now be achieved. The CRISPR/Cas9 system is the most recent addition to gene editing technologies and arguably the simplest requiring only two components; a small guide RNA molecule (sgRNA) and Cas9 endonuclease protein which complex to recognise and cleave a specific 20 bp target site present in a genome. Target specificity is determined by complementary base pairing between the sgRNA and target site sequence enabling highly specific, targeted mutation to be readily engineered. Upon target site cleavage, error-prone endogenous repair mechanisms produce small insertion/deletions at the target site usually resulting in loss of gene function. CRISPR/Cas9 gene editing has been rapidly adopted in plants and successfully undertaken in numerous species including major crop species. Its applications are not restricted to mutagenesis and target site cleavage can be exploited to promote sequence insertion or replacement by recombination. The multiple applications of this technology in plants are described.

  2. Integration of Orthogonal Signaling by the Notch and Dpp Pathways in Drosophila

    PubMed Central

    Stroebele, Elizabeth; Erives, Albert

    2016-01-01

    The transcription factor Suppressor of Hairless and its coactivator, the Notch intracellular domain, are polyglutamine (pQ)-rich factors that target enhancer elements and interact with other locally bound pQ-rich factors. To understand the functional repertoire of such enhancers, we identify conserved regulatory belts with binding sites for the pQ-rich effectors of both Notch and BMP/Dpp signaling, and the pQ-deficient tissue selectors Apterous (Ap), Scalloped (Sd), and Vestigial (Vg). We find that the densest such binding site cluster in the genome is located in the BMP-inducible nab locus, a homolog of the vertebrate transcriptional cofactors NAB1/