scholarly journals The Notch Intracellular Domain Can Function as a Coactivator for LEF-1

2001 ◽  
Vol 21 (22) ◽  
pp. 7537-7544 ◽  
Author(s):  
David A. Ross ◽  
Tom Kadesch
Keyword(s):  
Notch Signaling ◽  
Wnt Signaling Pathway ◽  
Notch Pathway ◽  
High Mobility ◽  
In Vitro Assays ◽  
Transactivation Domain ◽  
Intracellular Domain ◽  
Notch Intracellular Domain

ABSTRACT Notch signaling commences with two ligand-mediated proteolysis events that release the Notch intracellular domain, NICD, from the plasma membrane. NICD then translocates into the nucleus and interacts with the DNA binding protein CSL to activate transcription. We found that NICD expression also potentiates activity of the transcription factor LEF-1. NICD stimulation of LEF-1 activity was context dependent and occurred on a subset of promoters distinct from those activated by β-catenin. Importantly, the effect of NICD does not appear to be mediated through canonical components of the Wnt signaling pathway or downstream components of the Notch pathway. In vitro assays show a weak association between the C-terminal transactivation domain of NICD and the high-mobility group domain of LEF-1, suggesting that the two proteins interact in vivo. Our data therefore describe a new nuclear target of Notch signaling and a new coactivator for LEF-1.

scholarly journals NBS1 interacts with Notch signaling in neuronal homeostasis

2020 ◽  
Vol 48 (19) ◽  
pp. 10924-10939
Author(s):  
Zhong-Wei Zhou ◽  
Murat Kirtay ◽  
Nadine Schneble ◽  
George Yakoub ◽  
Mingmei Ding ◽  
...  
Keyword(s):  
Notch Signaling ◽  
Notch Pathway ◽  
Direct Consequence ◽  
Nijmegen Breakage Syndrome ◽  
Neuron Development ◽  
Genetic Ablation ◽  
Notch Activity ◽  
And Migration

Abstract NBS1 is a critical component of the MRN (MRE11/RAD50/NBS1) complex, which regulates ATM- and ATR-mediated DNA damage response (DDR) pathways. Mutations in NBS1 cause the human genomic instability syndrome Nijmegen Breakage Syndrome (NBS), of which neuronal deficits, including microcephaly and intellectual disability, are classical hallmarks. Given its function in the DDR to ensure proper proliferation and prevent death of replicating cells, NBS1 is essential for life. Here we show that, unexpectedly, Nbs1 deletion is dispensable for postmitotic neurons, but compromises their arborization and migration due to dysregulated Notch signaling. We find that Nbs1 interacts with NICD-RBPJ, the effector of Notch signaling, and inhibits Notch activity. Genetic ablation or pharmaceutical inhibition of Notch signaling rescues the maturation and migration defects of Nbs1-deficient neurons in vitro and in vivo. Upregulation of Notch by Nbs1 deletion is independent of the key DDR downstream effector p53 and inactivation of each MRN component produces a different pattern of Notch activity and distinct neuronal defects. These data indicate that neuronal defects and aberrant Notch activity in Nbs1-deficient cells are unlikely to be a direct consequence of loss of MRN-mediated DDR function. This study discloses a novel function of NBS1 in crosstalk with the Notch pathway in neuron development.

scholarly journals MicroRNA-26a and -26b inhibit lens fibrosis and cataract by negatively regulating Jagged-1/Notch signaling pathway

2017 ◽  
Vol 24 (8) ◽  
pp. 1431-1442 ◽  
Author(s):  
Xiaoyun Chen ◽  
Wei Xiao ◽  
Weirong Chen ◽  
Xialin Liu ◽  
Mingxing Wu ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Notch Signaling ◽  
Cancer Metastasis ◽  
Epithelial Mesenchymal Transition ◽  
Notch Pathway ◽  
Lens Epithelial Cells ◽  
Mesenchymal Transition ◽  
Fibrotic Diseases

Abstract Fibrosis is a chronic process involving development and progression of multiple diseases in various organs and is responsible for almost half of all known deaths. Epithelial–mesenchymal transition (EMT) is the vital process in organ fibrosis. Lens is an elegant biological tool to investigate the fibrosis process because of its unique biological properties. Using gain- and loss-of-function assays, and different lens fibrosis models, here we demonstrated that microRNA (miR)-26a and miR-26b, members of the miR-26 family have key roles in EMT and fibrosis. They can significantly inhibit proliferation, migration, EMT of lens epithelial cells and lens fibrosis in vitro and in vivo. Interestingly, we revealed that the mechanisms of anti-EMT effects of miR-26a and -26b are via directly targeting Jagged-1 and suppressing Jagged-1/Notch signaling. Furthermore, we provided in vitro and in vivo evidence that Jagged-1/Notch signaling is activated in TGFβ2-stimulated EMT, and blockade of Notch signaling can reverse lens epithelial cells (LECs) EMT and lens fibrosis. Given the general involvement of EMT in most fibrotic diseases, cancer metastasis and recurrence, miR-26 family and Notch pathway may have therapeutic uses in treating fibrotic diseases and cancers.

scholarly journals Notch pathway activation targets AML-initiating cell homeostasis and differentiation

2013 ◽  
Vol 210 (2) ◽  
pp. 301-319 ◽  
Author(s):  
Camille Lobry ◽  
Panagiotis Ntziachristos ◽  
Delphine Ndiaye-Lobry ◽  
Philmo Oh ◽  
Luisa Cimmino ◽  
...  
Keyword(s):  
Tumor Suppressor ◽  
Notch Signaling ◽  
Myeloproliferative Neoplasms ◽  
Notch Pathway ◽  
Notch Signaling Pathway ◽  
Notch Receptor ◽  
Pathway Activation ◽  
Function Models

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.

scholarly journals Loss of PLK2 induces acquired resistance to temozolomide in GBM via activation of Notch signaling

2020 ◽  
Author(s):  
Wahafu Alafate ◽  
Dongze Xu ◽  
Wei Wu ◽  
Jianyang Xiang ◽  
Xudong Ma ◽  
...  
Keyword(s):  
Notch Signaling ◽  
Acquired Resistance ◽  
Notch Pathway ◽  
Notch Signaling Pathway ◽  
Gene Expression Omnibus ◽  
Primary Brain Tumor ◽  
Biological Behavior ◽  
Clinical Samples

Abstract BackgroundGlioblastoma (GBM) is a lethal type of primary brain tumor with a median survival less than 15 months. Despite the recent improvements of comprehensive strategies, the outcomes for GBM patients remain dismal. Accumulating evidence indicates that rapid acquired chemoresistance is the major cause of GBM recurrence thus leads to worse clinical outcomes. Therefore, developing novel biomarkers and therapeutic targets for chemoresistant GBM is crucial for long-term cures. MethodsTranscriptomic profiles of glioblastoma were downloaded from gene expression omnibus (GEO) and TCGA database. Differentially expressed genes were analyzed and candidate gene PLK2 was selected for subsequent validation. Clinical samples and corresponding data were collected from our center and measured using immunohistochemistry analysis. Lentiviral transduction and in vivo xenograft transplantation were used to validate the bioinformatic findings. GSEA analyses were conducted to identify potential signaling pathways related to PLK2 expression and further confirmed by in vitro mechanistic assays. ResultsIn this study, we identified PLK2 as an extremely suppressed kinase-encoding gene in GBM samples, particularly in therapy resistant GBM. Additionally, reduced PLK2 expression implied poor prognosis and TMZ resistance in GBM patients. Functionally, up-regulated PLK2 attenuated cell proliferation, migration, invasion, and tumorigenesis of GBM cells. Besides, exogenous overexpression of PLK2 reduced acquired TMZ resistance of GBM cells. Furthermore, bioinformatics analysis indicated that PLK2 was negatively correlated with Notch signaling pathway in GBM. Mechanically, loss of PLK2 activated Notch pathway through negative transcriptional regulation of HES1 and degradation of Notch1.ConclusionLoss of PLK2 enhances aggressive biological behavior of GBM through activation of Notch signaling, indicating that PLK2 could be a prognostic biomarker and potential therapeutic target for chemoresistant GBM.

scholarly journals Structural and functional analysis of the repressor complex in the Notch signaling pathway ofDrosophila melanogaster

2011 ◽  
Vol 22 (17) ◽  
pp. 3242-3252 ◽  
Author(s):  
Dieter Maier ◽  
Patricia Kurth ◽  
Adriana Schulz ◽  
Andrew Russell ◽  
Zhenyu Yuan ◽  
...  
Keyword(s):  
Cell Culture ◽  
Notch Signaling ◽  
Target Genes ◽  
Notch Pathway ◽  
Structural Similarity ◽  
Receptor Activation ◽  
Notch Signaling Pathway ◽  
Repressor Complex

In metazoans, the highly conserved Notch pathway drives cellular specification. On receptor activation, the intracellular domain of Notch assembles a transcriptional activator complex that includes the DNA-binding protein CSL, a composite of human C-promoter binding factor 1, Suppressor of Hairless of Drosophila melanogaster [Su(H)], and lin-12 and Glp-1 phenotype of Caenorhabditis elegans. In the absence of ligand, CSL represses Notch target genes. However, despite the structural similarity of CSL orthologues, repression appears largely diverse between organisms. Here we analyze the Notch repressor complex in Drosophila, consisting of the fly CSL protein, Su(H), and the corepressor Hairless, which recruits general repressor proteins. We show that the C-terminal domain of Su(H) is necessary and sufficient for forming a high-affinity complex with Hairless. Mutations in Su(H) that affect interactions with Notch and Mastermind have no effect on Hairless binding. Nonetheless, we demonstrate that Notch and Hairless compete for CSL in vitro and in cell culture. In addition, we identify a site in Hairless that is crucial for binding Su(H) and subsequently show that this Hairless mutant is strongly impaired, failing to properly assemble the repressor complex in vivo. Finally, we demonstrate Hairless-mediated inhibition of Notch signaling in a cell culture assay, which hints at a potentially similar repression mechanism in mammals that might be exploited for therapeutic purposes.

scholarly journals Luteolin Inhibits Breast Cancer Development and Progression In Vitro and In Vivo by Suppressing Notch Signaling and Regulating MiRNAs

2015 ◽  
Vol 37 (5) ◽  
pp. 1693-1711 ◽  
Author(s):  
Da-Wei Sun ◽  
He-Da Zhang ◽  
Ling Mao ◽  
Chang-Fei Mao ◽  
Wei Chen ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Cycle ◽  
Notch Signaling ◽  
Notch Pathway ◽  
Tube Formation ◽  
Cancer Development ◽  
Notch 1 ◽  
Related Proteins

Background/Aims: This study aims to investigate the effect of Luteolin on breast cancer in vitro and in vivo and the interaction between miRNAs and Notch signaling after Luteolin intervention, and illustrates the possible underlying mechanism and regulation loop. Methods: Cell growth/survival assays and cell cycle analyses were performed to evaluate cell survival in vitro. Scratch tests, cell invasion assays and tube formation assays were carried out to analyze cell viability and identify the impact of Luteolin on angiogenesis. Critical components in the Notch pathway including proteins and mRNAs were detected by Western blotting analyses, ELISA assays and real-time reverse transcription-polymerase chain reaction. Matrix metalloproteinases activity was evaluated by gelatin zymography analyses. MiRNAs were analyzed by miRNA expression assays. After MDA-MB-231 cells were separately transfected with Notch-1 siRNA/cDNA and miRNA mimics, the above assays were also carried out to examine potential tumor cell changes. Xenograft models were applied to evaluate the treatment potency of Luteolin in breast cancer. Results: Luteolin significantly inhibited breast cancer cell survival, cell cycle, tube formation and the expression of Notch signaling-related proteins and mRNAs, and regulated miRNAs. After introducing Notch-1 siRNA and miRNA mimics, MDA-MB-231 cells presented with changes in miRNA levels, reduced Notch signaling-related proteins, and decreased tumor survival, invasion and angiogenesis. Conclusion: Luteolin inhibits Notch signaling by regulating miRNAs. However, the effect of miRNAs on the Notch pathway could be either Luteolin-dependent or Luteolin-independent. Furthermore, Notch-1 alteration may inversely change miRNAs levels. Our data demonstrates that Luteolin, miRNAs and the Notch pathway are critical in breast cancer development and prognosis.

scholarly journals Notch1 signaling stimulates proliferation of immature cardiomyocytes

2008 ◽  
Vol 183 (1) ◽  
pp. 117-128 ◽  
Author(s):  
Chiara Collesi ◽  
Lorena Zentilin ◽  
Gianfranco Sinagra ◽  
Mauro Giacca
Keyword(s):  
Notch Signaling ◽  
Cardiac Myocytes ◽  
Molecular Mechanisms ◽  
Notch Pathway ◽  
Constitutive Expression ◽  
Neonatal Rat ◽  
Proliferative Potential ◽  
Rat Cardiomyocytes

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.

A Novel Notch Pathway Inhibitor Blocks Osteoclast Activity and Synergistically Induces Apoptosis with the Proteasome Inhibitor Bortezomib in Multiple Myeloma Cells.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1522-1522
Author(s):  
Franziska Jundt ◽  
Rolf Schwarzer ◽  
Martin Kaiser ◽  
Oezlem Acikgoez ◽  
Ulrike Heider ◽  
...  
Keyword(s):  
Cell Growth ◽  
Notch Signaling ◽  
Proteasome Inhibitor ◽  
Notch Pathway ◽  
Growth And Survival ◽  
Osteoclast Activity ◽  
Notch Receptors ◽  
Induced Apoptosis

Abstract Notch pathway inhibition in multiple myeloma (MM) cells is a promising new therapeutic approach since it controls myeloma cell growth as we previously demonstrated (Blood. 2004; 103:3511–3515). Notch signaling is involved in the tight interactions between myeloma cells and the bone marrow microenvironment and induces tumor cell growth in MM. We provided evidence that Notch receptors are expressed on MM cells and that Notch ligands on MM and bone marrow stromal cells activate Notch signaling through homotypic as well as heterotypic interactions in MM cells. In this study, we analyzed whether Notch signaling might be activated in osteoclasts, which express Notch receptors but not the ligands. To that end, we co-cultured MM cells and human osteoclasts, which were generated from mononuclear hematopoietic precursors of healthy donors using in vitro RANKL/M-CSF stimulation. Co-cultivation specifically activated Notch in osteoclasts and induced osteoclast activity as measured by mRNA expression of the tartrate-resistant acid phosphatase. The novel Notch pathway inhibitor, so called γ-secretase inhibitor 1 (GSI1), that we recently identified by structural comparison of known inhibitors with unknown compounds by data bank screening, specifically inhibited Notch signaling in osteoclasts and blocked their activity in this co-cultivation assay. In addition, GSI1 induced apoptosis in osteoclasts in higher concentrations. We suggest from our data that GSI treatment controls MM cell growth and concomitantly aberrant osteoclast activity in vitro and possibly in vivo, that is under current investigation. We further hypothesized that GSI1 can be combined with the proteasome inhibitor bortezomib, which has been known to have in vitro and in vivo activity against MM. We evaluated the activity of the combination of GSI1 and bortezomib against MM cell growth and survival. Proliferation of MM cell lines treated with GSI, bortezomib and their combination was determined by CellTiter-Glo® luminescent cell viability assay. AnnexinV-FITC/PI staining and cleaved poly (ADP-ribose) polymerase (PARP) staining were used to determine the degree of apoptosis. Although treatment of MM cell lines (OPM2, LP1) with either drug alone significantly inhibited proliferation and induced apoptosis with concentrations of GSI1 (30–60 μM) and bortezomib (1–4 nM), the combination resulted in synergistic inhibition of cell growth and survival. Our data suggest that combination of GSI1 and bortezomib is a rational novel treatment option in MM that simultaneously targets different proliferative and anti-apoptotic pathways. Whether this combination might also have synergistic activity against aberrant osteoclast activity in MM will be further investigated.

scholarly journals Loss of PLK2 induces acquired resistance to temozolomide in GBM via activation of notch signaling

2020 ◽  
Vol 39 (1) ◽  
Author(s):  
Wahafu Alafate ◽  
Dongze Xu ◽  
Wei Wu ◽  
Jianyang Xiang ◽  
Xudong Ma ◽  
...  
Keyword(s):  
Notch Signaling ◽  
Acquired Resistance ◽  
Notch Pathway ◽  
Notch Signaling Pathway ◽  
Gene Expression Omnibus ◽  
Primary Brain Tumor ◽  
Biological Behavior ◽  
Clinical Samples

Abstract Background Glioblastoma (GBM) is a lethal type of primary brain tumor with a median survival less than 15 months. Despite the recent improvements of comprehensive strategies, the outcomes for GBM patients remain dismal. Accumulating evidence indicates that rapid acquired chemoresistance is the major cause of GBM recurrence thus leads to worse clinical outcomes. Therefore, developing novel biomarkers and therapeutic targets for chemoresistant GBM is crucial for long-term cures. Methods Transcriptomic profiles of glioblastoma were downloaded from gene expression omnibus (GEO) and TCGA database. Differentially expressed genes were analyzed and candidate gene PLK2 was selected for subsequent validation. Clinical samples and corresponding data were collected from our center and measured using immunohistochemistry analysis. Lentiviral transduction and in vivo xenograft transplantation were used to validate the bioinformatic findings. GSEA analyses were conducted to identify potential signaling pathways related to PLK2 expression and further confirmed by in vitro mechanistic assays. Results In this study, we identified PLK2 as an extremely suppressed kinase-encoding gene in GBM samples, particularly in therapy resistant GBM. Additionally, reduced PLK2 expression implied poor prognosis and TMZ resistance in GBM patients. Functionally, up-regulated PLK2 attenuated cell proliferation, migration, invasion, and tumorigenesis of GBM cells. Besides, exogenous overexpression of PLK2 reduced acquired TMZ resistance of GBM cells. Furthermore, bioinformatics analysis indicated that PLK2 was negatively correlated with Notch signaling pathway in GBM. Mechanically, loss of PLK2 activated Notch pathway through negative transcriptional regulation of HES1 and degradation of Notch1. Conclusion Loss of PLK2 enhances aggressive biological behavior of GBM through activation of Notch signaling, indicating that PLK2 could be a prognostic biomarker and potential therapeutic target for chemoresistant GBM.

scholarly journals SOX9 is an intestine crypt transcription factor, is regulated by the Wnt pathway, and represses the CDX2 and MUC2 genes

2004 ◽  
Vol 166 (1) ◽  
pp. 37-47 ◽  
Author(s):  
Philippe Blache ◽  
Marc van de Wetering ◽  
Isabelle Duluc ◽  
Claire Domon ◽  
Philippe Berta ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Intestinal Epithelium ◽  
Wnt Pathway ◽  
Wnt Signaling Pathway ◽  
High Mobility ◽  
Cell Phenotype ◽  
Expression Screening ◽  
Sox Proteins

TCF and SOX proteins belong to the high mobility group box transcription factor family. Whereas TCFs, the transcriptional effectors of the Wnt pathway, have been widely implicated in the development, homeostasis and disease of the intestine epithelium, little is known about the function of the SOX proteins in this tissue. Here, we identified SOX9 in a SOX expression screening in the mouse fetal intestine. We report that the SOX9 protein is expressed in the intestinal epithelium in a pattern characteristic of Wnt targets. We provide in vitro and in vivo evidence that a bipartite β-catenin/TCF4 transcription factor, the effector of the Wnt signaling pathway, is required for SOX9 expression in epithelial cells. Finally, in colon epithelium-derived cells, SOX9 transcriptionally represses the CDX2 and MUC2 genes, normally expressed in the mature villus cells of the intestinal epithelium, and may therefore contribute to the Wnt-dependent maintenance of a progenitor cell phenotype.

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