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Sample records for activates notch signaling

  1. PKCζ regulates Notch receptor routing and activity in a Notch signaling-dependent manner.

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    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.

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

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    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

  3. Notch signaling promotes osteoclast maturation and resorptive activity.

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    Ashley, Jason W; Ahn, Jaimo; Hankenson, Kurt D

    2015-11-01

    The role of Notch signaling in osteoclast differentiation is controversial with conflicting experimental evidence indicating both stimulatory and inhibitory roles. Differences in experimental protocols and in vivo versus in vitro models may explain the discrepancies between studies. In this study, we investigated cell autonomous roles of Notch signaling in osteoclast differentiation and function by altering Notch signaling during osteoclast differentiation using stimulation with immobilized ligands Jagged1 or Delta-like1 or by suppression with γ-secretase inhibitor DAPT or transcriptional inhibitor SAHM1. Stimulation of Notch signaling in committed osteoclast precursors resulted in larger osteoclasts with a greater number of nuclei and resorptive activity whereas suppression resulted in smaller osteoclasts with fewer nuclei and suppressed resorptive activity. Conversely, stimulation of Notch signaling in osteoclast precursors prior to induction of osteoclastogenesis resulted in fewer osteoclasts. Our data support a mechanism of context-specific Notch signaling effects wherein Notch stimulation inhibits commitment to osteoclast differentiation, but enhances the maturation and function of committed precursors.

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

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    Liu, Xin-Hua [Center of Excellence for the Medical Consequences of Spinal Cord Injury, James J. Peter VA Medical Center, Bronx, NY 10468 (United States); Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029 (United States); Yao, Shen; Qiao, Rui-Fang; Levine, Alice C. [Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029 (United States); Kirschenbaum, Alexander [Department of Urology, Mount Sinai School of Medicine, New York, NY 10029 (United States); Pan, Jiangping; Wu, Yong [Center of Excellence for the Medical Consequences of Spinal Cord Injury, James J. Peter VA Medical Center, Bronx, NY 10468 (United States); Qin, Weiping [Center of Excellence for the Medical Consequences of Spinal Cord Injury, James J. Peter VA Medical Center, Bronx, NY 10468 (United States); Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029 (United States); Bauman, William A. [Center of Excellence for the Medical Consequences of Spinal Cord Injury, James J. Peter VA Medical Center, Bronx, NY 10468 (United States); Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029 (United States); Rehabilitation Medicine, Mount Sinai School of Medicine, New York, NY 10029 (United States); Cardozo, Christopher P., E-mail: chris.cardozo@mssm.edu [Center of Excellence for the Medical Consequences of Spinal Cord Injury, James J. Peter VA Medical Center, Bronx, NY 10468 (United States); Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029 (United States); Rehabilitation Medicine, Mount Sinai School of Medicine, New York, NY 10029 (United States)

    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.

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

    International Nuclear Information System (INIS)

    Highlights: → Nerve transection increased Notch signaling in paralyzed muscle. → Nandrolone prevented denervation-induced Notch signaling. → Nandrolone induced the expression of an inhibitor of the Notch signaling, Numb. → 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.

  6. Opposing Activities of Notch and Wnt Signaling Regulate Intestinal Stem Cells and Gut Homeostasis

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    Hua Tian

    2015-04-01

    Full Text Available Proper organ homeostasis requires tight control of adult stem cells and differentiation through the integration of multiple inputs. In the mouse small intestine, Notch and Wnt signaling are required both for stem cell maintenance and for a proper balance of differentiation between secretory and absorptive cell lineages. In the absence of Notch signaling, stem cells preferentially generate secretory cells at the expense of absorptive cells. Here, we use function-blocking antibodies against Notch receptors to demonstrate that Notch blockade perturbs intestinal stem cell function by causing a derepression of the Wnt signaling pathway, leading to misexpression of prosecretory genes. Importantly, attenuation of the Wnt pathway rescued the phenotype associated with Notch blockade. These studies bring to light a negative regulatory mechanism that maintains stem cell activity and balanced differentiation, and we propose that the interaction between Wnt and Notch signaling described here represents a common theme in adult stem cell biology.

  7. Hepatitis B Virus HBx Activates Notch Signaling via Delta-Like 4/Notch1 in Hepatocellular Carcinoma.

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    Pornrat Kongkavitoon

    Full Text Available Hepatitis virus B (HBV infection is one of the major causes of hepatocellular carcinomas (HCC. HBx protein encoded in HBV genome is one of the key viral factors leading to malignant transformation of infected cells. HBx functions by interfering with cellular functions, causing aberration in cellular behaviour and transformation. Notch signalling is a well-conserved pathway involved in cellular differentiation, cell survival and cell death operating in various types of cells. Aberration in the Notch signalling pathways is linked to various tumors, including HCC. The role of HBx on the Notch signalling in HCC, however, is still controversial. In this study, we reported that HBV genome-containing HCC cell line HepG2 (HepG2.2.15 expressed higher Notch1 and Delta-like 4 (Dll4, compared to the control HepG2 without HBV genome. This upregulation coincided with increased appearance of the cleavage of Notch1, indicating constitutively activated Notch signalling. Silencing of HBx specifically reduced the level of Dll4 and cleaved Notch1. The increase in Dll4 level was confirmed in clinical specimens of HCC lesion, in comparison with non-tumor lesions. Using specific signalling pathway inhibitors, we found that MEK1/2, PI3K/AKT and NF-κB pathways are critical for HBx-mediated Dll4 upregulation. Silencing of HBx clearly decreased the level of phosphorylation of Akt and Erk1/2. Upon silencing of Dll4 in HepG2.2.15, decreased cleaved Notch1, increased apoptosis and cell cycle arrest were observed, suggesting a critical role of HBx-Dll4-Notch1 axis in regulating cell survival in HCC. Furthermore, clonogenic assay confirmed the important role of Dll4 in regulating cell survival of HBV-genome containing HCC cell line. Taken together, we reported a link between HBx and the Notch signalling in HCC that affects cell survival of HCC, which can be a potential target for therapy.

  8. Notch Signaling Is Associated With ALDH Activity And An Aggressive Metastatic Phenotype In Murine Osteosarcoma Cells

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    Xiaodong eMu

    2013-06-01

    Full Text Available Osteosarcoma (OS is the most common primary malignancy of bone, and pulmonary metastatic disease accounts for nearly all mortality. However, little is known about the biochemical signaling alterations that drive the progression of metastatic disease. Two murine OS cell populations, K7M2 and K12, are clonally related but differ significantly in their metastatic phenotypes and therefore represent excellent tools for studying metastatic OS molecular biology. K7M2 cells are highly metastatic, whereas K12 cells display limited metastatic potential. Here we report that the expression of Notch genes (Notch1, 2, 4 are up-regulated, including downstream targets Hes1 and Stat3, in the highly metastatic K7M2 cells compared to the less metastatic K12 cells, indicating that the Notch signaling pathway is more active in K7M2 cells. We have previously described that K7M2 cells exhibit higher levels of aldehyde dehydrogenase (ALDH activity. Here we report that K7M2 cell ALDH activity is reduced with Notch inhibition, suggesting that ALDH activity may be regulated in part by the Notch pathway. Notch signaling is also associated with increased resistance to oxidative stress, migration, invasion, and VEGF expression in vitro. However, Notch inhibition did not significantly alter K7M2 cell proliferation. In conclusion, we provide evidence that Notch signaling is associated with ALDH activity and increased metastatic behavior in OS cells. Both Notch and ALDH are putative molecular targets for the treatment and prevention of OS metastasis.

  9. Silybin-mediated inhibition of Notch signaling exerts antitumor activity in human hepatocellular carcinoma cells.

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    Song Zhang

    Full Text Available Hepatocellular carcinoma (HCC is a global health burden that is associated with limited treatment options and poor patient prognoses. Silybin (SIL, an antioxidant derived from the milk thistle plant (Silybum marianum, has been reported to exert hepatoprotective and antitumorigenic effects both in vitro and in vivo. While SIL has been shown to have potent antitumor activity against various types of cancer, including HCC, the molecular mechanisms underlying the effects of SIL remain largely unknown. The Notch signaling pathway plays crucial roles in tumorigenesis and immune development. In the present study, we assessed the antitumor activity of SIL in human HCC HepG2 cells in vitro and in vivo and explored the roles of the Notch pathway and of the apoptosis-related signaling pathway on the activity of SIL. SIL treatment resulted in a dose- and time-dependent inhibition of HCC cell viability. Additionally, SIL exhibited strong antitumor activity, as evidenced not only by reductions in tumor cell adhesion, migration, intracellular glutathione (GSH levels and total antioxidant capability (T-AOC but also by increases in the apoptotic index, caspase3 activity, and reactive oxygen species (ROS. Furthermore, SIL treatment decreased the expression of the Notch1 intracellular domain (NICD, RBP-Jκ, and Hes1 proteins, upregulated the apoptosis pathway-related protein Bax, and downregulated Bcl2, survivin, and cyclin D1. Notch1 siRNA (in vitro or DAPT (a known Notch1 inhibitor, in vivo further enhanced the antitumor activity of SIL, and recombinant Jagged1 protein (a known Notch ligand in vitro attenuated the antitumor activity of SIL. Taken together, these data indicate that SIL is a potent inhibitor of HCC cell growth that targets the Notch signaling pathway and suggest that the inhibition of Notch signaling may be a novel therapeutic intervention for HCC.

  10. Notch Activation of Ca(2+) Signaling in the Development of Hypoxic Pulmonary Vasoconstriction and Pulmonary Hypertension.

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    Smith, Kimberly A; Voiriot, Guillaume; Tang, Haiyang; Fraidenburg, Dustin R; Song, Shanshan; Yamamura, Hisao; Yamamura, Aya; Guo, Qiang; Wan, Jun; Pohl, Nicole M; Tauseef, Mohammad; Bodmer, Rolf; Ocorr, Karen; Thistlethwaite, Patricia A; Haddad, Gabriel G; Powell, Frank L; Makino, Ayako; Mehta, Dolly; Yuan, Jason X-J

    2015-09-01

    Hypoxic pulmonary vasoconstriction (HPV) is an important physiological response that optimizes the ventilation/perfusion ratio. Chronic hypoxia causes vascular remodeling, which is central to the pathogenesis of hypoxia-induced pulmonary hypertension (HPH). We have previously shown that Notch3 is up-regulated in HPH and that activation of Notch signaling enhances store-operated Ca(2+) entry (SOCE), an important mechanism that contributes to pulmonary arterial smooth muscle cell (PASMC) proliferation and contraction. Here, we investigate the role of Notch signaling in HPV and hypoxia-induced enhancement of SOCE. We examined SOCE in human PASMCs exposed to hypoxia and pulmonary arterial pressure in mice using the isolated perfused/ventilated lung method. Wild-type and canonical transient receptor potential (TRPC) 6(-/-) mice were exposed to chronic hypoxia to induce HPH. Inhibition of Notch signaling with a γ-secretase inhibitor attenuates hypoxia-enhanced SOCE in PASMCs and hypoxia-induced increase in pulmonary arterial pressure. Our results demonstrate that hypoxia activates Notch signaling and up-regulates TRPC6 channels. Additionally, treatment with a Notch ligand can mimic hypoxic responses. Finally, inhibition of TRPC6, either pharmacologically or genetically, attenuates HPV, hypoxia-enhanced SOCE, and the development of HPH. These results demonstrate that hypoxia-induced activation of Notch signaling mediates HPV and the development of HPH via functional activation and up-regulation of TRPC6 channels. Understanding the molecular mechanisms that regulate cytosolic free Ca(2+) concentration and PASMC proliferation is critical to elucidation of the pathogenesis of HPH. Targeting Notch regulation of TRPC6 will be beneficial in the development of novel therapies for pulmonary hypertension associated with hypoxia. PMID:25569851

  11. Contributions of chaperone and glycosyltransferase activities of O-fucosyltransferase 1 to Notch signaling

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    Irvine Kenneth D

    2008-01-01

    Full Text Available Abstract Background O-fucosyltransferase1 (OFUT1 is a conserved ER protein essential for Notch signaling. OFUT1 glycosylates EGF domains, which can then be further modified by the N-acetylglucosaminyltransferase Fringe. OFUT1 also possesses a chaperone activity that promotes the folding and secretion of Notch. Here, we investigate the respective contributions of these activities to Notch signaling in Drosophila. Results We show that expression of an isoform lacking fucosyltransferase activity, Ofut1R245A, rescues the requirement for Ofut1 in embryonic neurogenesis. Lack of requirement for O-fucosylation is further supported by the absence of embryonic phenotypes in Gmd mutants, which lack all forms of fucosylation. Requirements for O-fucose during imaginal development were evaluated by characterizing clones of cells expressing only Ofut1R245A. These clones phenocopy fringe mutant clones, indicating that the absence of O-fucose is functionally equivalent to the absence of elongated O-fucose. Conclusion Our results establish that Notch does not need to be O-fucosylated for fringe-independent Notch signaling in Drosophila; the chaperone activity of OFUT1 is sufficient for the generation of functional Notch.

  12. Notch and Wnt/β-catenin signaling pathway play important roles in activating liver cancer stem cells

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    Wang, Ronghua; Sun, Qian; Wang, Peng; Liu, Man; Xiong, Si; Luo, Jing; Huang, Hai; Du, Qiang; Geller, David A.; Cheng, Bin

    2016-01-01

    Human hepatocellular carcinoma (HCC) is driven and maintained by liver cancer stem cells (LCSCs) that display stem cell properties. These LCSCs are promoted by the intersecting of Notch and Wnt/β-Catenin signaling pathways. In this study, we demonstrate that LCSCs with markers CD90, CD24, CD13, and CD133 possess stem properties of self-renewal and tumorigenicity in NOD/SCID mice. The increased expression of these markers was correlated with advanced disease stage, larger tumors, and worse overall survival in 61 HCC cases. We also found that both Notch and Wnt/β-catenin signaling pathways played important roles in increasing the stem-ness characteristics of LCSCs. Our data suggested that Notch1 was downstream of Wnt/β-catenin. The active form of Notch1 intracellular domain (NICD) expression depended on Wnt/β-catenin pathway activation. Moreover, Notch1 negatively contributed to Wnt/β-catenin signaling modulation. Knock down of Notch1 with lentivirus N1ShRNA up-regulated the active form of β-catenin. Ectopic expression of NICD with LV-Notch1 in LCSCs attenuated β-catenin/TCF dependent luciferase activity significantly. In addition, there was a non-proteasome mediated feedback loop between Notch1 and Wnt/β-catenin signaling in LCSCs. The central role of Notch and the Wnt/β-catenin signaling pathway in LCSCs may provide an attractive therapeutic strategy against HCC. PMID:26735577

  13. Regulation of Notch Signaling by Glycosylation

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    Stanley, Pamela

    2007-01-01

    Notch receptors are ~300 kd cell surface glycoproteins whose activation by Notch ligands regulates cell fate decisions in the metazoa. The extracellular domain of Notch receptors has many epidermal growth factor-like repeats that are glycosylated with O-fucose and O-glucose glycans as well as N-glycans. Disruption of O-fucose glycan synthesis leads to severe Notch signaling defects in Drosophila and mammals. Removal or addition of O-fucose glycan consensus sites on Notch receptors also leads ...

  14. Notch-1 signaling promotes the malignant features of human breast cancer through NF-κB activation.

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    Li Li

    Full Text Available The aberrant activation of Notch-1 signaling pathway has been proven to be associated with the development and progression of cancers. However, the specific roles and the underlying mechanisms of Notch-1 signaling pathway on the malignant behaviors of breast cancer are poorly understood. In this study, using multiple cellular and molecular approaches, we demonstrated that activation of Notch-1 signaling pathway promoted the malignant behaviors of MDA-MB-231 cells such as increased cell proliferation, colony formation, adhesion, migration, and invasion, and inhibited apoptosis; whereas deactivation of this signaling pathway led to the reversal of the aforementioned malignant cellular behaviors. Furthermore, we found that activation of Notch-1 signaling pathway triggered the activation of NF-κB signaling pathway and up-regulated the expression of NF-κB target genes including MMP-2/-9, VEGF, Survivin, Bcl-xL, and Cyclin D1. These results suggest that Notch-1 signaling pathway play important roles in promoting the malignant phenotype of breast cancer, which may be mediated partly through the activation of NF-κB signaling pathway. Our results further suggest that targeting Notch-1 signaling pathway may become a newer approach to halt the progression of breast cancer.

  15. The lack of autophagy triggers precocious activation of Notch signaling during Drosophila oogenesis

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    Barth Julia MI

    2012-12-01

    Full Text Available Abstract Background The proper balance of autophagy, a lysosome-mediated degradation process, is indispensable for oogenesis in Drosophila. We recently demonstrated that egg development depends on autophagy in the somatic follicle cells (FC, but not in the germline cells (GCs. However, the lack of autophagy only affects oogenesis when FCs are autophagy-deficient but GCs are wild type, indicating that a dysfunctional signaling between soma and germline may be responsible for the oogenesis defects. Thus, autophagy could play an essential role in modulating signal transduction pathways during egg development. Results Here, we provide further evidence for the necessity of autophagy during oogenesis and demonstrate that autophagy is especially required in subsets of FCs. Generation of autophagy-deficient FCs leads to a wide range of phenotypes that are similar to mutants with defects in the classical cell-cell signaling pathways in the ovary. Interestingly, we observe that loss of autophagy leads to a precocious activation of the Notch pathway in the FCs as monitored by the expression of Cut and Hindsight, two downstream effectors of Notch signaling. Conclusion Our findings point to an unexpected function for autophagy in the modulation of the Notch signaling pathway during Drosophila oogenesis and suggest a function for autophagy in proper receptor activation. Egg development is affected by an imbalance of autophagy between signal sending (germline and signal receiving cell (FC, thus the lack of autophagy in the germline is likely to decrease the amount of active ligand and accordingly compensates for increased signaling in autophagy-defective follicle cells.

  16. O-fucose monosaccharide of Drosophila Notch has a temperature-sensitive function and cooperates with O-glucose glycan in Notch transport and Notch signaling activation.

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    Ishio, Akira; Sasamura, Takeshi; Ayukawa, Tomonori; Kuroda, Junpei; Ishikawa, Hiroyuki O; Aoyama, Naoki; Matsumoto, Kenjiroo; Gushiken, Takuma; Okajima, Tetsuya; Yamakawa, Tomoko; Matsuno, Kenji

    2015-01-01

    Notch (N) is a transmembrane receptor that mediates the cell-cell interactions necessary for many cell fate decisions. N has many epidermal growth factor-like repeats that are O-fucosylated by the protein O-fucosyltransferase 1 (O-Fut1), and the O-fut1 gene is essential for N signaling. However, the role of the monosaccharide O-fucose on N is unclear, because O-Fut1 also appears to have O-fucosyltransferase activity-independent functions, including as an N-specific chaperon. Such an enzymatic activity-independent function could account for the essential role of O-fut1 in N signaling. To evaluate the role of the monosaccharide O-fucose modification in N signaling, here we generated a knock-in mutant of O-fut1 (O-fut1(R245A knock-in)), which expresses a mutant protein that lacks O-fucosyltransferase activity but maintains the N-specific chaperon activity. Using O-fut1(R245A knock-in) and other gene mutations that abolish the O-fucosylation of N, we found that the monosaccharide O-fucose modification of N has a temperature-sensitive function that is essential for N signaling. The O-fucose monosaccharide and O-glucose glycan modification, catalyzed by Rumi, function redundantly in the activation of N signaling. We also showed that the redundant function of these two modifications is responsible for the presence of N at the cell surface. Our findings elucidate how different forms of glycosylation on a protein can influence the protein's functions.

  17. NK-like homeodomain proteins activate NOTCH3-signaling in leukemic T-cells

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    Drexler Hans G

    2009-10-01

    Full Text Available Abstract Background Homeodomain proteins control fundamental cellular processes in development and in cancer if deregulated. Three members of the NK-like subfamily of homeobox genes (NKLs, TLX1, TLX3 and NKX2-5, are implicated in T-cell acute lymphoblastic leukemia (T-ALL. They are activated by particular chromosomal aberrations. However, their precise function in leukemogenesis is still unclear. Here we screened further NKLs in 24 T-ALL cell lines and identified the common expression of MSX2. The subsequent aim of this study was to analyze the role of MSX2 in T-cell differentiation which may be disturbed by oncogenic NKLs. Methods Specific gene activity was examined by quantitative real-time PCR, and globally by expression profiling. Proteins were analyzed by western blot, immuno-cytology and immuno-precipitation. For overexpression studies cell lines were transduced by lentiviruses. Results Quantification of MSX2 mRNA in primary hematopoietic cells demonstrated higher levels in CD34+ stem cells as compared to peripheral blood cells and mature CD3+ T-cells. Furthermore, analysis of MSX2 expression levels in T-cell lines after treatment with core thymic factors confirmed their involvement in regulation. These results indicated that MSX2 represents an hematopoietic NKL family member which is downregulated during T-cell development and may functionally substituted by oncogenic NKLs. For functional analysis JURKAT cells were lentivirally transduced, overexpressing either MSX2 or oncogenic TLX1 and NKX2-5, respectively. These cells displayed transcriptional activation of NOTCH3-signaling, including NOTCH3 and HEY1 as analyzed by gene expression profiling and quantitative RT-PCR, and consistently attenuated sensitivity to gamma-secretase inhibitor as analyzed by MTT-assays. Furthermore, in addition to MSX2, both TLX1 and NKX2-5 proteins interacted with NOTCH-pathway repressors, SPEN/MINT/SHARP and TLE1/GRG1, representing a potential mechanism for

  18. Targeting Notch Signaling in Colorectal Cancer.

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    Suman, Suman; Das, Trinath P; Ankem, Murali K; Damodaran, Chendil

    2014-12-01

    The activation of Notch signaling is implicated in tumorigenesis in the colon due to the induction of pro-survival signaling in colonic epithelial cells. Chemoresistance is a major obstacle for treatment and for the complete eradication of colorectal cancer (CRC), hence, the inhibition of Notch is an attractive target for CRC and several groups are working to identify small molecules or monoclonal antibodies that inhibit Notch or its downstream events; however, toxicity profiles in normal cells and organs often impede the clinical translation of these molecules. Dietary agents have gained momentum for targeting several pro-survival signaling cascades, and recent studies demonstrated that agents that inhibit Notch signaling result in growth inhibition in preclinical models of CRC. In this review, we focus on the importance of Notch as a preventive and therapeutic target for colon cancer and on the effect of WA on this signaling pathway in the context of colon cancer. PMID:25395896

  19. Inhibition of myostatin signaling through Notch activation following acute resistance exercise.

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    Matthew G MacKenzie

    Full Text Available Myostatin is a TGFβ family member and negative regulator of muscle size. Due to the complexity of the molecular pathway between myostatin mRNA/protein and changes in transcription, it has been difficult to understand whether myostatin plays a role in resistance exercise-induced skeletal muscle hypertrophy. To circumvent this problem, we determined the expression of a unique myostatin target gene, Mighty, following resistance exercise. Mighty mRNA increased by 6 h (82.9 ± 24.21% and remained high out to 48 h (56.5 ± 19.67% after resistance exercise. Further examination of the soleus, plantaris and tibialis anterior muscles showed that the change in Mighty mRNA at 6 h correlated with the increase in muscle size associated with this protocol (R(2 = 0.9996. The increase in Mighty mRNA occurred both independent of Smad2 phosphorylation and in spite of an increase in myostatin mRNA (341.8 ± 147.14% at 3 h. The myostatin inhibitor SKI remained unchanged. However, activated Notch, another potential inhibitor of TGFβ signaling, increased immediately following resistance exercise (83 ± 11.2% and stayed elevated out to 6 h (78 ± 16.6%. Electroportion of the Notch intracellular domain into the tibialis anterior resulted in an increase in Mighty mRNA (63 ± 13.4% that was equivalent to the canonical Notch target HES-1 (94.4 ± 7.32%. These data suggest that acute resistance exercise decreases myostatin signaling through the activation of the TGFβ inhibitor Notch resulting in a decrease in myostatin transcriptional activity that correlates well with muscle hypertrophy.

  20. Collagen represses canonical Notch signaling and binds to Notch ectodomain

    OpenAIRE

    Zhang, Xiaojie; Meng, He; Michael M Wang

    2013-01-01

    The Notch signaling system features a growing number of modulators that include extracellular proteins that bind to the Notch ectodomain. Collagens are a complex, heterogeneous family of secreted proteins that serve both structural and signaling functions, most prominently through binding to integrins and DDR. The shared widespread tissue distribution of Notch and collagen prompted us to investigate the effects of collagen on Notch signaling. In a cell co-culture signaling assay, we found tha...

  1. Naringin Stimulates Osteogenic Differentiation of Rat Bone Marrow Stromal Cells via Activation of the Notch Signaling Pathway

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    Guo-yong Yu

    2016-01-01

    Full Text Available Naringin is a major flavonoid found in grapefruit and is an active compound extracted from the Chinese herbal medicine Rhizoma Drynariae. Naringin is a potent stimulator of osteogenic differentiation and has potential application in preventing bone loss. However, the signaling pathway underlying its osteogenic effect remains unclear. We hypothesized that the osteogenic activity of naringin involves the Notch signaling pathway. Rat bone marrow stromal cells (BMSCs were cultured in osteogenic medium containing-naringin, with or without DAPT (an inhibitor of Notch signaling, the effects on ALP activity, calcium deposits, osteogenic genes (ALP, BSP, and cbfa1, adipogenic maker gene PPARγ2 levels, and Notch expression were examined. We found that naringin dose-dependently increased ALP activity and Alizarin red S staining, and treatment at the optimal concentration (50 μg/mL increased mRNA levels of osteogenic genes and Notch1 expression, while decreasing PPARγ2 mRNA levels. Furthermore, treatment with DAPT partly reversed effects of naringin on BMSCs, as judged by decreases in naringin-induced ALP activity, calcium deposits, and osteogenic genes expression, as well as upregulation of PPARγ2 mRNA levels. These results suggest that the osteogenic effect of naringin partly involves the Notch signaling pathway.

  2. Naringin Stimulates Osteogenic Differentiation of Rat Bone Marrow Stromal Cells via Activation of the Notch Signaling Pathway.

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    Yu, Guo-Yong; Zheng, Gui-Zhou; Chang, Bo; Hu, Qin-Xiao; Lin, Fei-Xiang; Liu, De-Zhong; Wu, Chu-Cheng; Du, Shi-Xin; Li, Xue-Dong

    2016-01-01

    Naringin is a major flavonoid found in grapefruit and is an active compound extracted from the Chinese herbal medicine Rhizoma Drynariae. Naringin is a potent stimulator of osteogenic differentiation and has potential application in preventing bone loss. However, the signaling pathway underlying its osteogenic effect remains unclear. We hypothesized that the osteogenic activity of naringin involves the Notch signaling pathway. Rat bone marrow stromal cells (BMSCs) were cultured in osteogenic medium containing-naringin, with or without DAPT (an inhibitor of Notch signaling), the effects on ALP activity, calcium deposits, osteogenic genes (ALP, BSP, and cbfa1), adipogenic maker gene PPARγ2 levels, and Notch expression were examined. We found that naringin dose-dependently increased ALP activity and Alizarin red S staining, and treatment at the optimal concentration (50 μg/mL) increased mRNA levels of osteogenic genes and Notch1 expression, while decreasing PPARγ2 mRNA levels. Furthermore, treatment with DAPT partly reversed effects of naringin on BMSCs, as judged by decreases in naringin-induced ALP activity, calcium deposits, and osteogenic genes expression, as well as upregulation of PPARγ2 mRNA levels. These results suggest that the osteogenic effect of naringin partly involves the Notch signaling pathway. PMID:27069482

  3. Notch Signaling and Brain Tumors

    DEFF Research Database (Denmark)

    Stockhausen, Marie; Kristoffersen, Karina; Poulsen, Hans Skovgaard

    2011-01-01

    Human brain tumors are a heterogenous group of neoplasms occurring inside the cranium and the central spinal cord. In adults and children, astrocytic glioma and medulloblastoma are the most common subtypes of primary brain tumors. These tumor types are thought to arise from cells in which Notch...... signaling plays a fundamental role during development. Recent findings have shown that Notch signaling is dysregulated, and contributes to the malignant potential of these tumors. Growing evidence point towards an important role for cancer stem cells in the initiation and maintenance of glioma...... and medulloblastoma. In this chapter we will cover the present findings of Notch signaling in human glioma and medulloblastoma and try to create an overall picture of its relevance in the pathogenesis of these tumors....

  4. Gamma secretase inhibitors of Notch signaling

    Directory of Open Access Journals (Sweden)

    Olsauskas-Kuprys R

    2013-07-01

    Full Text Available Roma Olsauskas-Kuprys,1 Andrei Zlobin,1 Clodia Osipo1,2 1The Oncology Institute, Cardinal Bernardin Cancer Center, Loyola University Chicago, Chicago, IL, USA; 2Department of Pathology, Cardinal Bernardin Cancer Center, Loyola University Chicago, Chicago, IL, USA Abstract: The numerous processes involved in the etiology of breast cancer such as cell survival, metabolism, proliferation, differentiation, and angiogenesis are currently being elucidated. However, underlying mechanisms that drive breast cancer progression and drug resistance are still poorly understood. As we discuss here in detail, the Notch signaling pathway is an important regulatory component of normal breast development, cell fate of normal breast stem cells, and proliferation and survival of breast cancer initiating cells. Notch exerts a wide range of critical effects through a canonical pathway where it is expressed as a type I membrane precursor heterodimer followed by at least two subsequent cleavages induced by ligand engagement to ultimately release an intracellular form to function as a transcriptional activator. Notch and its ligands are overexpressed in breast cancer, and one method of effectively blocking Notch activity is preventing its cleavage at the cell surface with γ-secretase inhibitors. In the context of Notch signaling, the application of clinically relevant anti-Notch drugs in treatment regimens may contribute to novel therapeutic interventions and promote more effective clinical response in women with breast cancer. Keywords: breast cancer, signaling pathways, γ-secretase, γ-secretase inhibitors, combination breast cancer therapy

  5. Paradoxical effects of VEGF on synaptic activity partially involved in notch1 signaling in the mouse hippocampus.

    Science.gov (United States)

    Yang, Jiajia; Yang, Chunxiao; Liu, Chunhua; Zhang, Tao; Yang, Zhuo

    2016-05-01

    It is well known that the neuronal effects of vascular endothelial growth factor (VEGF) include modulating learning and memory, plasticity of mature neurons, and synaptic transmission in addition to neurogenesis. However, there is conflicting evidence particularly of its role in the regulation of excitatory synaptic activity. In this study, application of the patch-clamp technique revealed that lower doses (10 and 50 ng/mL) of VEGF enhanced excitatory neurotransmission in hippocampal slices of mice through both presynaptic and postsynaptic mechanisms. However, the effects were reversed by higher doses of VEGF (>100 ng/mL), which inhibited excitatory neurotransmission via a presynaptic mechanism. These competing, concentration-dependent effects of VEGF suggested that different pathways were involved. The involvement of the Notch1 receptor was tested in the modulation of VEGF on synaptic activity by using heterozygous Notch1(+/-) mice. Notch1 knockdown did not influence the inhibitory effect of high VEGF doses (200 ng/mL) but reduced the enhancement effects of low concentration of VEGF (50 ng/mL) at the postsynaptic level, which might be due to the decreased level of VEGF receptor. The results indicate that the Notch1 receptor plays a role in VEGF-induced modulation of synaptic activity, which provides new insights into a complex VEGF/Notch signaling cross-talk. These findings set the groundwork for understanding new mechanisms of Notch signaling and the neurotrophic effects of VEGF, which is beneficial to develop new therapeutic targets to the VEGF/Notch axis and improve current treatments for neural diseases. PMID:26482652

  6. Naringin Stimulates Osteogenic Differentiation of Rat Bone Marrow Stromal Cells via Activation of the Notch Signaling Pathway

    OpenAIRE

    Guo-yong Yu; Gui-zhou Zheng; Bo Chang; Qin-xiao Hu; Fei-xiang Lin; De-zhong Liu; Chu-cheng Wu; Shi-xin Du; Xue-dong Li

    2016-01-01

    Naringin is a major flavonoid found in grapefruit and is an active compound extracted from the Chinese herbal medicine Rhizoma Drynariae. Naringin is a potent stimulator of osteogenic differentiation and has potential application in preventing bone loss. However, the signaling pathway underlying its osteogenic effect remains unclear. We hypothesized that the osteogenic activity of naringin involves the Notch signaling pathway. Rat bone marrow stromal cells (BMSCs) were cultured in osteogenic ...

  7. Notching on cancer’s door: Notch signaling in brain tumors

    Directory of Open Access Journals (Sweden)

    Marcin eTeodorczyk

    2015-01-01

    Full Text Available Notch receptors play an essential role in the regulation of central cellular processes during embryonic and postnatal development. The mammalian genome encodes for four Notch paralogs (Notch 1-4, which are activated by three Delta-like (Dll1/3/4 and two Serrate-like (Jagged1/2 ligands. Further, non-canonical Notch ligands such as EGFL7 have been identified and serve mostly as antagonists of Notch signaling. The Notch pathway prevents neuronal differentiation in the central nervous system by driving neural stem cell maintenance and commitment of neural progenitor cells into the glial lineage. Notch is therefore often implicated in the development of brain tumors, as tumor cells share various characteristics with neural stem and progenitor cells. Notch receptors are overexpressed in gliomas and their oncogenicity has been confirmed by gain- and loss-of-function studies in vitro and in vivo. To this end, special attention is paid to the impact of Notch signaling on stem-like brain tumor-propagating cells as these cells contribute to growth, survival, invasion and recurrence of brain tumors. Based on the outcome of ongoing studies in vivo, Notch-directed therapies such as γ secretase inhibitors and blocking antibodies have entered and completed various clinical trials. This review summarizes the current knowledge on Notch signaling in brain tumor formation and therapy.

  8. Aberrant Activation of Notch Signaling Inhibits PROX1 Activity to Enhance the Malignant Behavior of Thyroid Cancer Cells.

    Science.gov (United States)

    Choi, Dongwon; Ramu, Swapnika; Park, Eunkyung; Jung, Eunson; Yang, Sara; Jung, Wonhyeuk; Choi, Inho; Lee, Sunju; Kim, Kyu Eui; Seong, Young Jin; Hong, Mingu; Daghlian, George; Kim, Daniel; Shin, Eugene; Seo, Jung In; Khatchadourian, Vicken; Zou, Mengchen; Li, Wei; De Filippo, Roger; Kokorowski, Paul; Chang, Andy; Kim, Steve; Bertoni, Ana; Furlanetto, Tania Weber; Shin, Sung; Li, Meng; Chen, Yibu; Wong, Alex; Koh, Chester; Geliebter, Jan; Hong, Young-Kwon

    2016-02-01

    Papillary thyroid cancer (PTC) is one of the most common endocrine malignancies associated with significant morbidity and mortality. Although multiple studies have contributed to a better understanding of the genetic alterations underlying this frequently arising disease, the downstream molecular effectors that impact PTC pathogenesis remain to be further defined. Here, we report that the regulator of cell fate specification, PROX1, becomes inactivated in PTC through mRNA downregulation and cytoplasmic mislocalization. Expression studies in clinical specimens revealed that aberrantly activated NOTCH signaling promoted PROX1 downregulation and that cytoplasmic mislocalization significantly altered PROX1 protein stability. Importantly, restoration of PROX1 activity in thyroid carcinoma cells revealed that PROX1 not only enhanced Wnt/β-catenin signaling but also regulated several genes known to be associated with PTC, including thyroid cancer protein (TC)-1, SERPINA1, and FABP4. Furthermore, PROX1 reexpression suppressed the malignant phenotypes of thyroid carcinoma cells, such as proliferation, motility, adhesion, invasion, anchorage-independent growth, and polyploidy. Moreover, animal xenograft studies demonstrated that restoration of PROX1 severely impeded tumor formation and suppressed the invasiveness and the nuclear/cytoplasmic ratio of PTC cells. Taken together, our findings demonstrate that NOTCH-induced PROX1 inactivation significantly promotes the malignant behavior of thyroid carcinoma and suggest that PROX1 reactivation may represent a potential therapeutic strategy to attenuate disease progression. PMID:26609053

  9. Evidence of non-canonical NOTCH signaling

    DEFF Research Database (Denmark)

    Traustadóttir, Gunnhildur Ásta; Jensen, Charlotte H; Thomassen, Mads;

    2016-01-01

    suggested to interact with NOTCH1 and act as an antagonist. This non-canonical interaction is, however controversial, and evidence for a direct interaction, still lacking in mammals. In this study, we elucidated the putative DLK1-NOTCH1 interaction in a mammalian context. Taking a global approach and using...... this interaction to occur between EGF domains 5 and 6 of DLK1 and EGF domains 10-15 of NOTCH1. Thus, our data provide the first evidence for a direct interaction between DLK1 and NOTCH1 in mammals, and substantiate that non-canonical NOTCH ligands exist, adding to the complexity of NOTCH signaling....

  10. Notch Signaling Activation in Cervical Cancer Cells Induces Cell Growth Arrest with the Involvement of the Nuclear Receptor NR4A2

    Science.gov (United States)

    Sun, Lichun; Liu, Mingqiu; Sun, Guang-Chun; Yang, Xu; Qian, Qingqing; Feng, Shuyu; Mackey, L. Vienna; Coy, David H.

    2016-01-01

    Cervical cancer is a second leading cancer death in women world-wide, with most cases in less developed countries. Notch signaling is highly conserved with its involvement in many cancers. In the present study, we established stable cervical cell lines with Notch activation and inactivation and found that Notch activation played a suppressive role in cervical cancer cells. Meanwhile, the transient overexpression of the active intracellular domain of all four Notch receptors (ICN1, 2, 3, and 4) also induced the suppression of cervical cancer Hela cell growth. ICN1 also induced cell cycle arrest at phase G1. Notch1 signaling activation affected the expression of serial genes, especially the genes associated with cAMP signaling, with an increase of genes like THBS1, VCL, p63, c-Myc and SCG2, a decrease of genes like NR4A2, PCK2 and BCL-2. Particularly, The nuclear receptor NR4A2 was observed to induce cell proliferation via MTT assay and reduce cell apoptosis via FACS assay. Furthermore, NR4A2's activation could reverse ICN1-induced suppression of cell growth while erasing ICN1-induced increase of tumor suppressor p63. These findings support that Notch signaling mediates cervical cancer cell growth suppression with the involvement of nuclear receptor NR4A2. Notably, Notch/NR4A2/p63 signaling cascade possibly is a new signling pathway undisclosed. PMID:27471554

  11. Canonical Notch activation in osteocytes causes osteopetrosis.

    Science.gov (United States)

    Canalis, Ernesto; Bridgewater, David; Schilling, Lauren; Zanotti, Stefano

    2016-01-15

    Activation of Notch1 in cells of the osteoblastic lineage inhibits osteoblast differentiation/function and causes osteopenia, whereas its activation in osteocytes causes a distinct osteopetrotic phenotype. To explore mechanisms responsible, we established the contributions of canonical Notch signaling (Rbpjκ dependent) to osteocyte function. Transgenics expressing Cre recombinase under the control of the dentin matrix protein-1 (Dmp1) promoter were crossed with Rbpjκ conditional mice to generate Dmp1-Cre(+/-);Rbpjκ(Δ/Δ) mice. These mice did not have a skeletal phenotype, indicating that Rbpjκ is dispensable for osteocyte function. To study the Rbpjκ contribution to Notch activation, Rosa(Notch) mice, where a loxP-flanked STOP cassette is placed between the Rosa26 promoter and the NICD coding sequence, were crossed with Dmp1-Cre transgenic mice and studied in the context (Dmp1-Cre(+/-);Rosa(Notch);Rbpjκ(Δ/Δ)) or not (Dmp1-Cre(+/-);Rosa(Notch)) of Rbpjκ inactivation. Dmp1-Cre(+/-);Rosa(Notch) mice exhibited increased femoral trabecular bone volume and decreased osteoclasts and bone resorption. The phenotype was reversed in the context of the Rbpjκ inactivation, demonstrating that Notch canonical signaling was accountable for the phenotype. Notch activation downregulated Sost and Dkk1 and upregulated Axin2, Tnfrsf11b, and Tnfsf11 mRNA expression, and these effects were not observed in the context of the Rbpjκ inactivation. In conclusion, Notch activation in osteocytes suppresses bone resorption and increases bone volume by utilization of canonical signals that also result in the inhibition of Sost and Dkk1 and upregulation of Wnt signaling. PMID:26578715

  12. Structure of the Notch1-negative regulatory region: implications for normal activation and pathogenic signaling in T-ALL

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, Wendy R.; Roy, Monideepa; Vardar-Ulu, Didem; Garfinkel, Megan; Mansour, Marc R.; Aster, Jon C.; Blacklow, Stephen C.; (BWH); (Wellesley); (UCL)

    2009-09-02

    Proteolytic resistance of Notch prior to ligand binding depends on the structural integrity of a negative regulatory region (NRR) of the receptor that immediately precedes the transmembrane segment. The NRR includes the 3 Lin12/Notch repeats and the juxtamembrane heterodimerization domain, the region of Notch1 most frequently mutated in T-cell acute lymphoblastic leukemia lymphoma (T-ALL). Here, we report the x-ray structure of the Notch1 NRR in its autoinhibited conformation. A key feature of the Notch1 structure that maintains its closed conformation is a conserved hydrophobic plug that sterically occludes the metalloprotease cleavage site. Crystal packing interactions involving a highly conserved, exposed face on the third Lin12/Notch repeat suggest that this site may normally be engaged in intermolecular or intramolecular protein-protein interactions. The majority of known T-ALL-associated point mutations map to residues in the hydrophobic interior of the Notch1 NRR. A novel mutation (H1545P), which alters a residue at the crystal-packing interface, leads to ligand-independent increases in signaling in reporter gene assays despite only mild destabilization of the NRR, suggesting that it releases the autoinhibitory clamp on the heterodimerization domain imposed by the Lin12/Notch repeats. The Notch1 NRR structure should facilitate a search for antibodies or compounds that stabilize the autoinhibited conformation.

  13. Human papillomavirus 16E6 and NFX1-123 potentiate notch signaling and differentiation without activating cellular arrest

    Energy Technology Data Exchange (ETDEWEB)

    Vliet-Gregg, Portia A.; Hamilton, Jennifer R. [Center for Global Infectious Disease Research, Seattle Children' s Research Institute, 1900 Ninth Ave., Seattle, WA 98101 (United States); Katzenellenbogen, Rachel A., E-mail: rkatzen@uw.edu [Center for Global Infectious Disease Research, Seattle Children' s Research Institute, 1900 Ninth Ave., Seattle, WA 98101 (United States); Department of Pediatrics, Division of Adolescent Medicine, University of Washington, Seattle WA (United States)

    2015-04-15

    High-risk human papillomavirus (HR HPV) oncoproteins bind host cell proteins to dysregulate and uncouple apoptosis, senescence, differentiation, and growth. These pathways are important for both the viral life cycle and cancer development. HR HPV16 E6 (16E6) interacts with the cellular protein NFX1-123, and they collaboratively increase the growth and differentiation master regulator, Notch1. In 16E6 expressing keratinocytes (16E6 HFKs), the Notch canonical pathway genes Hes1 and Hes5 were increased with overexpression of NFX1-123, and their expression was directly linked to the activation or blockade of the Notch1 receptor. Keratinocyte differentiation genes Keratin 1 and Keratin 10 were also increased, but in contrast their upregulation was only indirectly associated with Notch1 receptor stimulation and was fully unlinked to growth arrest, increased p21{sup Waf1/CIP1}, or decreased proliferative factor Ki67. This leads to a model of 16E6, NFX1-123, and Notch1 differently regulating canonical and differentiation pathways and entirely uncoupling cellular arrest from increased differentiation. - Highlights: • 16E6 and NFX1-123 increased the Notch canonical pathway through Notch1. • 16E6 and NFX1-123 increased the differentiation pathway indirectly through Notch1. • 16E6 and NFX1-123 increased differentiation gene expression without growth arrest. • Increased NFX1-123 with 16E6 may create an ideal cellular phenotype for HPV.

  14. Notch Signaling in Inflammation-Induced Preterm Labor.

    Science.gov (United States)

    Jaiswal, Mukesh K; Agrawal, Varkha; Pamarthy, Sahithi; Katara, Gajendra K; Kulshrestha, Arpita; Gilman-Sachs, Alice; Beaman, Kenneth D; Hirsch, Emmet

    2015-01-01

    Notch signaling plays an important role in regulation of innate immune responses and trophoblast function during pregnancy. To identify the role of Notch signaling in preterm labor, Notch receptors (Notch1-4), its ligands (DLL (Delta-like protein)-1/3/4), Jagged 1/2) and Notch-induced transcription factor Hes1 were assessed during preterm labor. Preterm labor was initiated on gestation day 14.5 by intrauterine (IU) injection of peptidoglycan (PGN) and polyinosinic:cytidylic acid (poly(I:C). Notch1, Notch2, Notch4, DLL-1 and nuclear localization of Hes1 were significantly elevated in uterus and placenta during PGN+poly(I:C)-induced preterm labor. Ex vivo, Gamma secretase inhibitor (GSI) (inhibitor of Notch receptor processing) significantly diminished the PGN+poly(I:C)-induced secretion of M1- and M2-associated cytokines in decidual macrophages, and of proinflammatory cytokines (IFN-γ, TNF-α and IL-6) and chemokines (MIP-1β) in decidual and placental cells. Conversely, angiogenesis factors including Notch ligands Jagged 1/2 and DLL-4 and VEGF were significantly reduced in uterus and placenta during PGN+poly(I:C)-induced preterm labor. In vivo GSI treatment prevents PGN+poly(I:C)-induced preterm delivery by 55.5% and increased the number of live fetuses in-utero significantly compared to respective controls 48 hrs after injections. In summary, Notch signaling is activated during PGN+poly(I:C)-induced preterm labor, resulting in upregulation of pro-inflammatory responses, and its inhibition improves in-utero survival of live fetuses. PMID:26472156

  15. Nontranscriptional Role of Hif-1α in Activation of γ-Secretase and Notch Signaling in Breast Cancer

    Directory of Open Access Journals (Sweden)

    Jennifer C. Villa

    2014-08-01

    Full Text Available γ-Secretase is composed of four proteins that are obligatory for protease activity: presenilin, nicastrin, Aph1, and Pen-2. Despite the progress toward understanding the function of these individual subunits, there is no information available pertaining to the modulation of γ-secretase in response to environmental changes in cells. Here, we show that hypoxia upregulates γ-secretase activity through a direct interaction with Hif-1α, revealing an unconventional function for Hif-1α as an enzyme subunit, which is distinct from its canonical role as a transcription factor. Moreover, hypoxia-induced cell invasion and metastasis are alleviated by either γ-secretase inhibitors or a dominant-negative Notch coactivator, indicating that γ-secretase/Notch signaling plays an essential role in controlling these cellular processes. The present study reveals a mechanism in which γ-secretase can achieve temporal control through conditional interactions with regulatory proteins, such as Hif-1α, under select physiological and pathological conditions.

  16. Notch signalling mediates reproductive constraint in the adult worker honeybee

    Science.gov (United States)

    Duncan, Elizabeth J.; Hyink, Otto; Dearden, Peter K.

    2016-01-01

    The hallmark of eusociality is the reproductive division of labour, in which one female caste reproduces, while reproduction is constrained in the subordinate caste. In adult worker honeybees (Apis mellifera) reproductive constraint is conditional: in the absence of the queen and brood, adult worker honeybees activate their ovaries and lay haploid male eggs. Here, we demonstrate that chemical inhibition of Notch signalling can overcome the repressive effect of queen pheromone and promote ovary activity in adult worker honeybees. We show that Notch signalling acts on the earliest stages of oogenesis and that the removal of the queen corresponds with a loss of Notch protein in the germarium. We conclude that the ancient and pleiotropic Notch signalling pathway has been co-opted into constraining reproduction in worker honeybees and we provide the first molecular mechanism directly linking ovary activity in adult worker bees with the presence of the queen. PMID:27485026

  17. Linking Notch signaling to ischemic stroke

    OpenAIRE

    Arboleda-Velasquez, Joseph F.; Zhou, Zhipeng; Shin, Hwa Kyoung; Louvi, Angeliki; Kim, Hyung-Hwan; Savitz, Sean I.; Liao, James K.; Salomone, Salvatore; Ayata, Cenk; Moskowitz, Michael A.; Artavanis-Tsakonas, Spyros

    2008-01-01

    Vascular smooth muscle cells (SMCs) have been implicated in the pathophysiology of stroke, the third most common cause of death and the leading cause of long-term neurological disability in the world. However, there is little insight into the underlying cellular pathways that link SMC function to brain ischemia susceptibility. Using a hitherto uncharacterized knockout mouse model of Notch 3, a Notch signaling receptor paralogue highly expressed in vascular SMCs, we uncover a striking suscepti...

  18. Effects of varying Notch1 signal strength on embryogenesis and vasculogenesis in compound mutant heterozygotes

    Directory of Open Access Journals (Sweden)

    Ge Changhui

    2010-03-01

    contrast, compound heterozygotes with Notch112f in combination with a Notch1 null allele (Notch1tm1Con were capable of surviving to birth. Conclusions Notch1 signaling in Notch112f/lbd compound heterozygous embryos is more defective than in compound heterozygotes expressing a hypomorphic Notch112f allele and a Notch1 null allele. The data suggest that the gene products Notch1lbd and Notch112f interact to reduce the activity of Notch112f.

  19. Notch signaling stimulates osteogenic differentiation of human bone marrow-derived mesenchymal stem cells

    Institute of Scientific and Technical Information of China (English)

    LU Zhuozhuang; WU Zuze(WU Chutse); ZHANG Qunwei; WANG Hua; JIA Xiangxu; DUAN Haifeng; WANG Lisheng

    2004-01-01

    Notch signaling is one of the most important pathways mediating cell determination and differentiation. In this study, the roles of Notch signal in the regulation of osteogenic differentiation of human bone marrow mesenchymal stem cells (hMSCs) were investigated. The expression of Notch1, Jagged1 and DTX1 detected by reverse transcription polymerase chain reaction (RT-PCR) suggested that Notch signal might exhibit a physiological regulatory role in the differentiation of MSCs. Constitutive expression of the intracellular domain of Notch1 (ICN), the active form of Notch1 protein, can activate Notch signal in cells without ligands' binding. hMSCs were isolated, expanded, and infected with retrovirus carrying green fluorescent protein (GFP) gene or ICN. Overexpression of ICN in hMSCs resulted in enhanced osteogenic differentiation induced by dexamethasone (Dex), which was characterized by an increase of cellular alkaline phosphatase (ALP) activity and calcium deposition. These results indicate that Notch stimulates differentiation of MSCs into osteoblasts.

  20. NOTCH SIGNALING REGULATES MOUSE AND HUMAN TH17 DIFFERENTIATION

    OpenAIRE

    Keerthivasan, Shilpa; Suleiman, Reem; Lawlor, Rebecca; Roderick, Justine; Bates, Tonya; Minter, Lisa; Anguita, Juan; Juncadella, Ignacio; Nickoloff, Brian J; Le Poole, I. Caroline; Miele, Lucio; Osborne, Barbara A.

    2011-01-01

    T helper17 (Th17) cells are known to play a critical role in adaptive immune responses to several important extracellular pathogens. Additionally, Th17 cells are implicated in the pathogenesis of several autoimmune and inflammatory disorders as well as in cancer. Therefore, it is essential to understand the mechanisms that regulate Th17 differentiation. Notch signaling is known to be important at several stages of T cell development and differentiation. Here we report that Notch1 is activated...

  1. Notch signaling modulates proliferation and differentiation of intestinal crypt base columnar stem cells

    OpenAIRE

    VanDussen, Kelli L; Carulli, Alexis J.; Keeley, Theresa M.; Patel, Sanjeevkumar R.; Puthoff, Brent J.; Magness, Scott T.; Tran, Ivy T.; Maillard, Ivan; Siebel, Christian; Kolterud, Åsa; Grosse, Ann S.; Gumucio, Deborah L; Ernst, Stephen A.; Tsai, Yu-Hwai; Dempsey, Peter J.

    2012-01-01

    Notch signaling is known to regulate the proliferation and differentiation of intestinal stem and progenitor cells; however, direct cellular targets and specific functions of Notch signals had not been identified. We show here in mice that Notch directly targets the crypt base columnar (CBC) cell to maintain stem cell activity. Notch inhibition induced rapid CBC cell loss, with reduced proliferation, apoptotic cell death and reduced efficiency of organoid initiation. Furthermore, expression o...

  2. Current views on the role of Notch signaling and the pathogenesis of human leukemia

    Directory of Open Access Journals (Sweden)

    Pancewicz Joanna

    2011-11-01

    Full Text Available Abstract The Notch signaling pathway is highly conserved from Drosophila to humans and plays an important role in the regulation of cellular proliferation, differentiation and apoptosis. Constitutive activation of Notch signaling has been shown to result in excessive cellular proliferation and a wide range of malignancies, including leukemia, glioblastoma and lung and breast cancers. Notch can also act as a tumor suppressor, and its inactivation has been associated with an increased risk of spontaneous squamous cell carcinoma. This minireview focuses on recent advances related to the mechanisms and roles of activated Notch1, Notch2, Notch3 and Notch4 signaling in human lymphocytic leukemia, myeloid leukemia and B cell lymphoma, as well as their significance, and recent advances in Notch-targeted therapies.

  3. [Neural stem cells and Notch signalling].

    Science.gov (United States)

    Traiffort, Elisabeth; Ferent, Julien

    2015-12-01

    Development and repair of the nervous system are based on the existence of neural stem cells (NSCs) able to generate neurons and glial cells. Among the mechanisms that are involved in the control of embryo or adult NSCs, the Notch signalling plays a major role. In embryo, the pathway participates in the maintenance of NSCs during all steps of development of the central nervous system which starts with the production of neurons also called neurogenesis and continues with gliogenesis giving rise to astrocytes and oligodendrocytes. During the postnatal and adult period, Notch signalling is still present in the major neurogenic areas, the subventricular zone of the lateral ventricles and the subgranular zone of the hippocampus. In these regions, Notch maintains NSC quiescence, contributes to the heterogeneity of these cells and displays pleiotropic effects during the regeneration process occurring after a lesion. PMID:26672665

  4. SIRT1 regulates endothelial Notch signaling in lung cancer.

    Directory of Open Access Journals (Sweden)

    Mian Xie

    Full Text Available BACKGROUND: Sirtuin 1 (SIRT1 acts as a key regulator of vascular endothelial homeostasis, angiogenesis, and endothelial dysfunction. However, the underlying mechanism for SIRT1-mediated lung carcinoma angiogenesis remains unknown. Herein, we report that the nicotinamide adenine dinucleotide 1 (NAD1-dependent deacetylase SIRT1 can function as an intrinsic negative modulator of Delta-like ligand 4 (DLL4/Notch signaling in Lewis lung carcinoma (LLC xenograft-derived vascular endothelial cells (lung cancer-derived ECs. PRINCIPAL FINDINGS: SIRT1 negatively regulates Notch1 intracellular domain (N1IC and Notch1 target genes HEY1 and HEY2 in response to Delta-like ligand 4 (DLL4 stimulation. Furthermore, SIRT1 deacetylated and repressed N1IC expression. Quantitative chromatin immunoprecipitation (qChIP analysis and gene reporter assay demonstrated that SIRT1 bound to one highly conserved region, which was located at approximately -500 bp upstream of the transcriptional start site of Notch1,and repressed Notch1 transcription. Inhibition of endothelial cell growth and sprouting angiogenesis by DLL4/Notch signaling was enhanced in SIRT1-silenced lung cancer-derived EC and rescued by Notch inhibitor DAPT. In vivo, an increase in proangiogenic activity was observed in Matrigel plugs from endothelial-specific SIRT1 knock-in mice. SIRT1 also enhanced tumor neovascularization and tumor growth of LLC xenografts. CONCLUSIONS: Our results show that SIRT1 facilitates endothelial cell branching and proliferation to increase vessel density and promote lung tumor growth through down-regulation of DLL4/Notch signaling and deacetylation of N1IC. Thus, targeting SIRT1 activity or/and gene expression may represent a novel mechanism in the treatment of lung cancer.

  5. Notch1 Signaling Modulates Neuronal Progenitor Activity in the Subventricular Zone in Response to Aging and Focal Ischemia

    OpenAIRE

    Sun, Fen; Mao, XiaoOu; Xie, Lin; Ding, Meiping; Shao, Bei; Jin, Kunlin

    2013-01-01

    Neurogenesis diminishes with aging and ischemia-induced neurogenesis also occurs, but reduced in aged brain. Currently, the cellular and molecular pathways mediating these effects remain largely unknown. Our previous study has shown that Notch1 signaling regulates neurogenesis in subventricular zone (SVZ) of young-adult brain after focal ischemia, but whether a similar effect occurs in aged normal and ischemic animals is unknown. Here, we used normal and ischemic aged rat br...

  6. Metastasis-associated lung adenocarcinoma transcript 1 promotes the proliferation of chondro­sarcoma cell via activating Notch-1 signaling pathway

    Directory of Open Access Journals (Sweden)

    Xu FQ

    2016-04-01

    Full Text Available Fengqin Xu,1,* Zhi-qiang Zhang,2,* Yong-chao Fang,2 Xiao-lei Li,2 Yu Sun,2 Chuan-zhi Xiong,2 Lian-qi Yan,2 Qiang Wang2 1Department of Orthopaedics, Hongquan Hospital, 2Department of Orthopaedics, Subei People’s Hospital, Yangzhou, Jiangsu Province, People’s Republic of China *These authors contributed equally to this work Background: Metastasis-associated lung adenocarcinoma transcript 1 (MALAT-1 is identified to be overexpressed in several cancers. However, the role of MALAT-1 in chondrosarcoma is poorly understood.Methods: The expression of MALAT-1 and Notch-1 signaling pathway was detected in chondrosarcoma tissues and chondrosarcoma cells by quantitative real-time polymerase chain reaction (qRT-PCR and Western blot. 3-(4,5-Dimethyl-2-thiazolyl-2,5-diphenyl-2-H-tetrazolium bromide (MTT assay was performed to examine the cell viability of chondrosarcoma cells transfected with si-MALAT-1 or pcDNA-MALAT-1. Then the expression of Notch-1 signaling pathway was detected when MALAT-1 was upregulated or downregulated in chondrosarcoma cells. A subcutaneous chondrosarcoma cells xenograft model was used to confirm the effect of MALAT-1 on tumor growth in vivo.Results: We found the increased expression of MALAT-1 and Notch-1 signaling pathway in chondrosarcoma tissue and cells. MALAT-1 promoted the proliferation of chondrosarcoma cells. In addition, MALAT-1 activated the Notch-1 signaling pathway at posttranscriptional level in chondrosarcoma cells. Meanwhile, overexpression of Notch-1 reversed the effect of si-MALAT-1 on the proliferation of chondrosarcoma cells. Finally, we found that MALAT-1 promoted the tumor growth in a subcutaneous chondrosarcoma cells xenograft model, which confirmed the promoted effect of MALAT-1 on the tumor growth in vivo.Conclusion: Taken together, our study demonstrated that MALAT-1 promoted the proliferation of chondrosarcoma cell via activating Notch-1 signaling pathway. Keywords: MALAT-1, cell proliferation

  7. Role of Notch signaling in the mammalian heart

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, X.L.; Liu, J.C. [Department of Cardiac Surgery, The First Affiliated Hospital, Nanchang University, Donghu District, Nanchang, Jiangxi (China)

    2013-12-12

    Notch signaling is an evolutionarily ancient, highly conserved pathway important for deciding cell fate, cellular development, differentiation, proliferation, apoptosis, adhesion, and epithelial-to-mesenchymal transition. Notch signaling is also critical in mammalian cardiogenesis, as mutations in this signaling pathway are linked to human congenital heart disease. Furthermore, Notch signaling can repair myocardial injury by promoting myocardial regeneration, protecting ischemic myocardium, inducing angiogenesis, and negatively regulating cardiac fibroblast-myofibroblast transformation. This review provides an update on the known roles of Notch signaling in the mammalian heart. The goal is to assist in developing strategies to influence Notch signaling and optimize myocardial injury repair.

  8. Role of Notch signaling in the mammalian heart

    Directory of Open Access Journals (Sweden)

    X.L. Zhou

    2014-01-01

    Full Text Available Notch signaling is an evolutionarily ancient, highly conserved pathway important for deciding cell fate, cellular development, differentiation, proliferation, apoptosis, adhesion, and epithelial-to-mesenchymal transition. Notch signaling is also critical in mammalian cardiogenesis, as mutations in this signaling pathway are linked to human congenital heart disease. Furthermore, Notch signaling can repair myocardial injury by promoting myocardial regeneration, protecting ischemic myocardium, inducing angiogenesis, and negatively regulating cardiac fibroblast-myofibroblast transformation. This review provides an update on the known roles of Notch signaling in the mammalian heart. The goal is to assist in developing strategies to influence Notch signaling and optimize myocardial injury repair.

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

    Science.gov (United States)

    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.

  10. A Role for Notch Signalling in Breast Cancer and Endocrine Resistance

    Science.gov (United States)

    Acar, Ahmet; Simões, Bruno M.; Clarke, Robert B.; Brennan, Keith

    2016-01-01

    Over the past decade, there has been growing interest in the Notch signalling pathway within the breast cancer field. This interest stemmed initially from the observation that Notch signalling is aberrantly activated in breast cancer and its effects on various cellular processes including proliferation, apoptosis, and cancer stem cell activity. However more recently, elevated Notch signalling has been correlated with therapy resistance in oestrogen receptor-positive breast cancer. As a result, inhibiting Notch signalling with therapeutic agents is being explored as a promising treatment option for breast cancer patients. PMID:26880941

  11. The role of Notch signaling in development and tumorigenesis

    OpenAIRE

    Mazur, Pawel Karol

    2010-01-01

    This thesis underscores the high importance of Notch signaling in the development of pancreas and liver as well as in tumorigenesis of pancreas and skin. Pancreas-specific ablation of Notch signaling impairs exocrine cell expansion and leads to premature differentiation of progenitor into endocrine cells. In addition, Notch was found to play an essential role in pancreas recovery after acute pancreatitis. Also, Notch is critical for intrahepatic bile duct formation during liver maturation. Fi...

  12. OSM-11 facilitates LIN-12 Notch signaling during Caenorhabditis elegans vulval development.

    Directory of Open Access Journals (Sweden)

    Hidetoshi Komatsu

    2008-08-01

    Full Text Available Notch signaling is critical for cell fate decisions during development. Caenorhabditis elegans and vertebrate Notch ligands are more diverse than classical Drosophila Notch ligands, suggesting possible functional complexities. Here, we describe a developmental role in Notch signaling for OSM-11, which has been previously implicated in defecation and osmotic resistance in C. elegans. We find that complete loss of OSM-11 causes defects in vulval precursor cell (VPC fate specification during vulval development consistent with decreased Notch signaling. OSM-11 is a secreted, diffusible protein that, like previously described C. elegans Delta, Serrate, and LAG-2 (DSL ligands, can interact with the lineage defective-12 (LIN-12 Notch receptor extracellular domain. Additionally, OSM-11 and similar C. elegans proteins share a common motif with Notch ligands from other species in a sequence defined here as the Delta and OSM-11 (DOS motif. osm-11 loss-of-function defects in vulval development are exacerbated by loss of other DOS-motif genes or by loss of the Notch ligand DSL-1, suggesting that DOS-motif and DSL proteins act together to activate Notch signaling in vivo. The mammalian DOS-motif protein Deltalike1 (DLK1 can substitute for OSM-11 in C. elegans development, suggesting that DOS-motif function is conserved across species. We hypothesize that C. elegans OSM-11 and homologous proteins act as coactivators for Notch receptors, allowing precise regulation of Notch receptor signaling in developmental programs in both vertebrates and invertebrates.

  13. Notch Signaling Mediates Skeletal Muscle Atrophy in Cancer Cachexia Caused by Osteosarcoma.

    Science.gov (United States)

    Mu, Xiaodong; Agarwal, Rashmi; March, Daniel; Rothenberg, Adam; Voigt, Clifford; Tebbets, Jessica; Huard, Johnny; Weiss, Kurt

    2016-01-01

    Skeletal muscle atrophy in cancer cachexia is mediated by the interaction between muscle stem cells and various tumor factors. Although Notch signaling has been known as a key regulator of both cancer development and muscle stem cell activity, the potential involvement of Notch signaling in cancer cachexia and concomitant muscle atrophy has yet to be elucidated. The murine K7M2 osteosarcoma cell line was used to generate an orthotopic model of sarcoma-associated cachexia, and the role of Notch signaling was evaluated. Skeletal muscle atrophy was observed in the sarcoma-bearing mice, and Notch signaling was highly active in both tumor tissues and the atrophic skeletal muscles. Systemic inhibition of Notch signaling reduced muscle atrophy. In vitro coculture of osteosarcoma cells with muscle-derived stem cells (MDSCs) isolated from normal mice resulted in decreased myogenic potential of MDSCs, while the application of Notch inhibitor was able to rescue this repressed myogenic potential. We further observed that Notch-activating factors reside in the exosomes of osteosarcoma cells, which activate Notch signaling in MDSCs and subsequently repress myogenesis. Our results revealed that signaling between tumor and muscle via the Notch pathway may play an important role in mediating the skeletal muscle atrophy seen in cancer cachexia. PMID:27378829

  14. Inhibition of fibroblast growth by Notch1 signaling is mediated by induction of Wnt11-dependent WISP-1.

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    Zhao-Jun Liu

    Full Text Available Fibroblasts are an integral component of stroma and important source of growth factors and extracellular matrix (ECM. They play a prominent role in maintaining tissue homeostasis and in wound healing and tumor growth. Notch signaling regulates biological function in a variety of cells. To elucidate the physiological function of Notch signaling in fibroblasts, we ablated Notch1 in mouse (Notch1(Flox/Flox embryonic fibroblasts (MEFs. Notch1-deficient (Notch1(-/- MEFs displayed faster growth and motility rate compared to Notch1(Flox/Flox MEFs. Such phenotypic changes, however, were reversible by reconstitution of Notch1 activation via overexpression of the intracellular domain of Notch1 (NICD1 in Notch1-deficient MEFs. In contrast, constitutive activation of Notch1 signaling by introducing NICD1 into primary human dermal fibroblasts (FF2441, which caused pan-Notch activation, inhibited cell growth and motility, whereas cellular inhibition was relievable when the Notch activation was countered with dominant-negative mutant of Master-mind like 1 (DN-MAML-1. Functionally, "Notch-activated" stromal fibroblasts could inhibit tumor cell growth/invasion. Moreover, Notch activation induced expression of Wnt-induced secreted proteins-1 (WISP-1/CCN4 in FF2441 cells while deletion of Notch1 in MEFs resulted in an opposite effect. Notably, WISP-1 suppressed fibroblast proliferation, and was responsible for mediating Notch1's inhibitory effect since siRNA-mediated blockade of WISP-1 expression could relieve cell growth inhibition. Notch1-induced WISP-1 expression appeared to be Wnt11-dependent, but Wnt1-independent. Blockade of Wnt11 expression resulted in decreased WISP-1 expression and liberated Notch-induced cell growth inhibition. These findings indicated that inhibition of fibroblast proliferation by Notch pathway activation is mediated, at least in part, through regulating Wnt1-independent, but Wnt11-dependent WISP-1 expression.

  15. Resveratrol can prevent CCl₄-induced liver injury by inhibiting Notch signaling pathway.

    Science.gov (United States)

    Tanriverdi, Gamze; Kaya-Dagistanli, Fatma; Ayla, Sule; Demirci, Sibel; Eser, Mediha; Unal, Z Seda; Cengiz, Mujgan; Oktar, Huseyin

    2016-07-01

    We investigated whether Notch signaling was increased in an experimental liver fibrosis model and examined the effects of resveratrol on Notch expression. Rats were divided into four groups: the control group, injected with physiological saline; the CCl₄ group; the CCl₄ plus resveratrol group; and the resveratrol group. After treatment, immunostaining was performed to detect Notch1, Notch3, Notch4, transforming growth factor (TGF)-beta, alpha-smooth muscle actin (SMA), glial fibrillary acidic protein (GFAP), and proliferating cell nuclear antigen (PCNA), and TUNEL assays were performed to evaluate apoptosis. Sirius red staining was used to detect fibrosis. Samples were also biochemically evaluated for glutathione (GSH), glutathione peroxidase (GPx), catalase (CAT), lipid peroxidation, and protein oxidation. GSH, GPx, and catalase activities were significantly decreased (p⟨0.001) in the CCl₄ group. Distinct collagen accumulation was detected around the central vein and portal areas, and numbers of Notch1-, Notch3-, and Notch4-positive cells were significantly increased (p⟨0.001) in fibrotic areas in the CCl₄ group. Increased expression of Notch proteins in fibrotic areas may support the role of Notch in mediating signaling associated with liver fibrosis through activation of hepatic stellate and progenitor cells. In contrast, resveratrol prevented liver fibrosis by decreasing lipid peroxidation and may be effective for inhibiting Notch signaling. PMID:26742567

  16. Activation of Dll4/Notch Signaling and Hypoxia-Inducible Factor-1 Alpha Facilitates Lymphangiogenesis in Lacrimal Glands in Dry Eye.

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    Ji Hwan Min

    Full Text Available By using hypoxia-inducible factor-1 alpha conditional knockout (HIF-1α CKO mice and a dry eye (DE mouse model, we aimed to determine the role played by delta-like ligand 4 (Dll4/Notch signaling and HIF-1α in the lymphangiogenesis of lacrimal glands (LGs.C57BL/6 mice were housed in a controlled-environment chamber for DE induction. During DE induction, the expression level of Dll4/Notch signaling and lymphangiogenesis in LGs was measured by quantitative RT-PCR, immunoblot, and immunofluorescence staining. Next, lymphangiogenesis was measured after Dll4/Notch signal inhibition by anti-Dll4 antibody or γ-secretase inhibitor. Using HIF-1α CKO mice, the expression of Dll4/Notch signaling and lymphangiogenesis in LGs of DE-induced HIF-1α CKO mice were assessed. Additionally, the infiltration of CD45+ cells in LGs was assessed by immunohistochemical (IHC staining and flow cytometry for each condition.DE significantly upregulated Dll4/Notch and lymphangiogenesis in LGs. Inhibition of Dll4/Notch significantly suppressed lymphangiogenesis in LGs. Compared to wild-type (WT mice, DE induced HIF-1α CKO mice showed markedly low levels of Dll4/Notch and lymphangiogenesis. Inhibition of lymphangiogenesis by Dll4/Notch suppression resulted in increased CD45+ cell infiltration in LGs. Likewise, CD45+ cells infiltrated more in the LGs of HIF-1α CKO DE mice than in non-DE HIF-1α CKO mice.Dll4/Notch signaling and HIF-1α are closely related to lymphangiogenesis in DE-induced LGs. Lymphangiogenesis stimulated by Dll4/Notch and HIF-1α may play a role in protecting LGs from DE-induced inflammation by aiding the clearance of immune cells from LGs.

  17. Cardioprotective actions of Notch1 against myocardial infarction via LKB1-dependent AMPK signaling pathway.

    Science.gov (United States)

    Yang, Hui; Sun, Wanqing; Quan, Nanhu; Wang, Lin; Chu, Dongyang; Cates, Courtney; Liu, Quan; Zheng, Yang; Li, Ji

    2016-05-15

    AMP-activated protein kinase (AMPK) signaling pathway plays a pivotal role in intracellular adaptation to energy stress during myocardial ischemia. Notch1 signaling in the adult myocardium is also activated in response to ischemic stress. However, the relationship between Notch1 and AMPK signaling pathways during ischemia remains unclear. We hypothesize that Notch1 as an adaptive signaling pathway protects the heart from ischemic injury via modulating the cardioprotective AMPK signaling pathway. C57BL/6J mice were subjected to an in vivo ligation of left anterior descending coronary artery and the hearts from C57BL/6J mice were subjected to an ex vivo globe ischemia and reperfusion in the Langendorff perfusion system. The Notch1 signaling was activated during myocardial ischemia. A Notch1 γ-secretase inhibitor, dibenzazepine (DBZ), was intraperitoneally injected into mice to inhibit Notch1 signaling pathway by ischemia. The inhibition of Notch1 signaling by DBZ significantly augmented cardiac dysfunctions caused by myocardial infarction. Intriguingly, DBZ treatment also significantly blunted the activation of AMPK signaling pathway. The immunoprecipitation experiments demonstrated that an interaction between Notch1 and liver kinase beta1 (LKB1) modulated AMPK activation during myocardial ischemia. Furthermore, a ligand of Notch1 Jagged1 can significantly reduce cardiac damage caused by ischemia via activation of AMPK signaling pathway and modulation of glucose oxidation and fatty acid oxidation during ischemia and reperfusion. But Jagged1 did not have any cardioprotections on AMPK kinase dead transgenic hearts. Taken together, the results indicate that the cardioprotective effect of Notch1 against ischemic damage is mediated by AMPK signaling via an interaction with upstream LKB1.

  18. Role of Notch signaling in cell-fate determination of human mammary stem/progenitor cells

    International Nuclear Information System (INIS)

    Notch signaling has been implicated in the regulation of cell-fate decisions such as self-renewal of adult stem cells and differentiation of progenitor cells along a particular lineage. Moreover, depending on the cellular and developmental context, the Notch pathway acts as a regulator of cell survival and cell proliferation. Abnormal expression of Notch receptors has been found in different types of epithelial metaplastic lesions and neoplastic lesions, suggesting that Notch may act as a proto-oncogene. The vertebrate Notch1 and Notch4 homologs are involved in normal development of the mammary gland, and mutated forms of these genes are associated with development of mouse mammary tumors. In order to determine the role of Notch signaling in mammary cell-fate determination, we have utilized a newly described in vitro system in which mammary stem/progenitor cells can be cultured in suspension as nonadherent 'mammospheres'. Notch signaling was activated using exogenous ligands, or was inhibited using previously characterized Notch signaling antagonists. Utilizing this system, we demonstrate that Notch signaling can act on mammary stem cells to promote self-renewal and on early progenitor cells to promote their proliferation, as demonstrated by a 10-fold increase in secondary mammosphere formation upon addition of a Notch-activating DSL peptide. In addition to acting on stem cells, Notch signaling is also able to act on multipotent progenitor cells, facilitating myoepithelial lineage-specific commitment and proliferation. Stimulation of this pathway also promotes branching morphogenesis in three-dimensional Matrigel cultures. These effects are completely inhibited by a Notch4 blocking antibody or a gamma secretase inhibitor that blocks Notch processing. In contrast to the effects of Notch signaling on mammary stem/progenitor cells, modulation of this pathway has no discernable effect on fully committed, differentiated, mammary epithelial cells. These studies

  19. Drosophila Cyclin G Is a Regulator of the Notch Signalling Pathway during Wing Development

    Science.gov (United States)

    Nagel, Anja C.; Szawinski, Jutta; Zimmermann, Mirjam; Preiss, Anette

    2016-01-01

    Notch signalling regulates a multitude of differentiation processes during Drosophila development. For example, Notch activity is required for proper wing vein differentiation which is hampered in mutants of either the receptor Notch, the ligand Delta or the antagonist Hairless. Moreover, the Notch pathway is involved in several aspects of Drosophila oogenesis as well. We have identified Drosophila Cyclin G (CycG) as a molecular interaction partner of Hairless, the major antagonist in the Notch signalling pathway, in vitro and in vivo. Loss of CycG was shown before to cause female sterility and to disturb the architecture of the egg shell. Nevertheless, Notch dependent processes during oogenesis appeared largely unaffected in cycG mutant egg chambers. Loss of CycG modified the dominant wing phenotypes of Notch, Delta and Hairless mutants. Whereas the Notch loss of function phenotype was ameliorated by a loss of CycG, the phenotypes of either Notch gain of function or of Delta or Hairless loss of function were enhanced. In contrast, loss of CycG had only a minor effect on the wing vein phenotype of mutants affecting the EGFR signalling pathway emphasizing the specificity of the interaction of CycG and Notch pathway members. PMID:26963612

  20. Effect of Trastuzumab on Notch-1 Signaling Pathway in Breast Cancer SK-BR3 Cells

    Institute of Scientific and Technical Information of China (English)

    Ming Han; Hua-yu Deng; Rong Jiang

    2012-01-01

    Objective:To investigate the effects and mechanisms of trastuzumab on Notch-1 pathway in breast cancer cells,recognizing the significance of Notch-1 signaling pathway in trastuzumab resistance.Methods:Immunocytochemistry staining and Western blotting were employed to justify the expression of Notch-1 protein in HER2-overexpressing SK-BR3 cells and HER2-non-overexpressing breast cancer MDA-MB-231 cells.Western blotting and reverse transcription PCR (RT-PCR) were used to detect the activated Notch-1 and Notch-1 target gene HES-1 mRNA expression after SK-BR3 cells were treated with trastuzumab.Double immunofluorescence staining and co-immunoprecipitation were used to analyze the relationship of Notch-1 and HER2 proteins.Results:The level of Notch-1 nuclear localization and activated Notch-1 proteins in HER2-overexpressing cells were significantly lower than in HER2-non-overexpressing cells (P<0.01),and the expressions of activated Notch-1 and HES-1 mRNA were obviously increased after trastuzumab treatment (P<1.05),but HER2 expression did not change significantly for trastuzumab treating (P>0.05).Moreover,Notch-1 was discovered to co-localize and interact with HER2 in SK-BR3 cells.Conclusion:Overexpression of HER2 decreased Notch-1 activity by the formation of a HER2-Notch1 complex,and trastuzumab can restore the activity of Notch-1 signaling pathway,which could be associated with cell resistance to trastuzumab.

  1. Fibulin-3 promotes glioma growth and resistance through a novel paracrine regulation of Notch signaling.

    Science.gov (United States)

    Hu, Bin; Nandhu, Mohan S; Sim, Hosung; Agudelo-Garcia, Paula A; Saldivar, Joshua C; Dolan, Claire E; Mora, Maria E; Nuovo, Gerard J; Cole, Susan E; Viapiano, Mariano S

    2012-08-01

    Malignant gliomas are highly invasive and chemoresistant brain tumors with extremely poor prognosis. Targeting of the soluble factors that trigger invasion and resistance, therefore, could have a significant impact against the infiltrative glioma cells that are a major source of recurrence. Fibulin-3 is a matrix protein that is absent in normal brain but upregulated in gliomas and promotes tumor invasion by unknown mechanisms. Here, we show that fibulin-3 is a novel soluble activator of Notch signaling that antagonizes DLL3, an autocrine inhibitor or Notch, and promotes tumor cell survival and invasion in a Notch-dependent manner. Using a strategy for inducible knockdown, we found that controlled downregulation of fibulin-3 reduced Notch signaling and led to increased apoptosis, reduced self-renewal of glioblastoma-initiating cells, and impaired growth and dispersion of intracranial tumors. In addition, fibulin-3 expression correlated with expression levels of Notch-dependent genes and was a marker of Notch activation in patient-derived glioma samples. These findings underscore a major role for the tumor extracellular matrix in regulating glioma invasion and resistance to apoptosis via activation of the key Notch pathway. More importantly, this work describes a noncanonical, soluble activator of Notch in a cancer model and shows how Notch signaling can be reduced by targeting tumor-specific accessible molecules in the tumor microenvironment. PMID:22665268

  2. Notch1通路活化抑制EC109细胞的增殖及机制探讨%Activated Notch1 signaling inhibits growth of EC109 cell line and its mechanism

    Institute of Scientific and Technical Information of China (English)

    张永利; 张可杰; 闵祥辉; 鹿全意; 刘文励

    2009-01-01

    Background and purpose: It has been reported that activation of Notch1 could strongly inhibit proliferation of HPV (human papilloma virus)-positive HeLa cells by down-regulation of the E6 and E7 genes. The aim of this paper was to investigate the role of the Notch signaling pathway in growth arrest of EC109 cells in vitro and the molecular mechanism. Methods: EC109 cell lines, a well differentiated human ESCC (esophageal squamous cell carcinoma) cell line with HPV18-positive, was used in the study. Exogenous intracellular domain of Notch1(ICN) was transfected into cultured EC109 cells by lipofectamine transfection, the proliferation of the transfected cells was measured by an MTT assay. Cell cycle distribution was analyzed by flow cytometry. Human papilloma virus type 18 (HPV18) E6/E7 mRNA expression was detected by RT-PCR, and p53 protein expression was detected by Western blot.Results: Activation of Notchl signaling resulted in inhibition of EC109 cell proliferation with the induction of G_2/ M arrest. There was a significant difference in terms of the percentage of G_2/M phase cells among the ICN-transfected group (42.57±1.57)% and the non-transfected group (1.88±0.66)% or the empty plasmid transfected group (1.99±1.02)% (P<0.01). Down modulation of HPV18 E6/E7 gene expression and upregulation of p53 expression was (2.15±0.23) in ICN-transfected group higher than non- transfected group (0.45±0.07) and empty plasmid transfected group (0.46±0.02) (P<0.01). Conclusion: Repression of HPV18 E6/E7 expression by Notch1 signaling results in growth suppression of HPV18-positive EC109 cells with concomitant activation of p53-mediated pathways.%背景与目的:Notch1的活化可以通过下调人类乳头状瘤病毒(human papillomavirus,HPV)早期蛋白E6和E7基因的表达抑制HPV阳性HeLa细胞系的增殖.人食管鳞状细胞癌细胞系EC109细胞为HPV18阳性细胞.本研究将Notch1胞内段(intracellular domain of Notch,ICN)转入EC109细胞,导致EC109

  3. Cooperation of Notch and Ras/MAPK signaling pathways in human breast carcinogenesis

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    Dey Devaveena

    2009-12-01

    Full Text Available Abstract Background Recent studies have implicated aberrant Notch signaling in breast cancers. Yet, relatively little is known about the pattern of expression of various components of the Notch pathway, or its mechanism of action. To better understand the role of the Notch pathway in breast cancer, we have undertaken a detailed expression analysis of various Notch receptors, their ligands, and downstream targets at different stages of breast cancer progression. Results We report here that there is a general increase in the expression levels of Notch 1, 2, 4, Jagged1, Jagged2, and Delta-like 4 proteins in breast cancers, with simultaneous upregulation of multiple Notch receptors and ligands in a given cancer tissue. While Notch3 and Delta-like1 were undetectable in normal tissues, moderate to high expression was detected in several cancers. We detected the presence of active, cleaved Notch1, along with downstream targets of the Notch pathway, Hes1/Hes5, in ~75% of breast cancers, clearly indicating that in a large proportion of breast cancers Notch signaling is aberrantly activated. Furthermore, we detected cleaved Notch1 and Hes1/5 in early precursors of breast cancers - hyperplasia and ductal carcinoma in situ - suggesting that aberrant Notch activation may be an early event in breast cancer progression. Mechanistically, while constitutively active Notch1 alone failed to transform immortalized breast cells, it synergized with the Ras/MAPK pathway to mediate transformation. This cooperation is reflected in vivo, as a subset of cleaved Notch positive tumors additionally expressed phopsho-Erk1/2 in the nuclei. Such cases exhibited high node positivity, suggesting that Notch-Ras cooperation may lead to poor prognosis. Conclusions High level expression of Notch receptors and ligands, and its increased activation in several breast cancers and early precursors, places Notch signaling as a key player in breast cancer pathogenesis. Its cooperation with

  4. hCLP46 regulates U937 cell proliferation via Notch signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Wenzhan; Du, Jie; Chu, Qiaoyun [College of Life Science, Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Wang, Youxin [School of Public Health and Family Medicine, Capital Medical University, Beijing 100069 (China); Liu, Lixin [College of Life Science, Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Song, Manshu [School of Public Health and Family Medicine, Capital Medical University, Beijing 100069 (China); Wang, Wei, E-mail: wei6014@yahoo.com [College of Life Science, Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); School of Public Health and Family Medicine, Capital Medical University, Beijing 100069 (China)

    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.

  5. The Notch-2 gene is regulated by Wnt signaling in cultured colorectal cancer cells.

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    Jonas Ungerbäck

    Full Text Available BACKGROUND: Notch and Wnt pathways are key regulators of intestinal homeostasis and alterations in these pathways may lead to the development of colorectal cancer (CRC. In CRC the Apc/β-catenin genes in the Wnt signaling pathway are frequently mutated and active Notch signaling contributes to tumorigenesis by keeping the epithelial cells in a proliferative state. These pathways are simultaneously active in proliferative adenoma cells and a crosstalk between them has previously been suggested in normal development as well as in cancer. PRINCIPAL FINDINGS: In this study, in silico analysis of putative promoters involved in transcriptional regulation of genes coding for proteins in the Notch signaling pathway revealed several putative LEF-1/TCF sites as potential targets for β-catenin and canonical Wnt signaling. Further results from competitive electrophoretic mobility-shift assay (EMSA studies suggest binding of several putative sites in Notch pathway gene promoters to in vitro translated β-catenin/Lef-1. Wild type (wt-Apc negatively regulates β-catenin. By induction of wt-Apc or β-catenin silencing in HT29 cells, we observed that several genes in the Notch pathway, including Notch-2, were downregulated. Finally, active Notch signaling was verified in the Apc(Min/+ mouse model where Hes-1 mRNA levels were found significantly upregulated in intestinal tumors compared to normal intestinal mucosa. Luciferase assays showed an increased activity for the core and proximal Notch-2 promoter upon co-transfection of HCT116 cells with high expression recombinant Tcf-4, Lef-1 or β-catenin. CONCLUSIONS: In this paper, we identified Notch-2 as a novel target for β-catenin-dependent Wnt signaling. Furthermore our data supports the notion that additional genes in the Notch pathway might be transcriptionally regulated by Wnt signaling in colorectal cancer.

  6. Role of Notch1/2 signaling pathway in the apoptosis process of SGC-7901 induced by Oxaliplatin

    Institute of Scientific and Technical Information of China (English)

    Zhi-Ling Tang; Ke-Quan Chen; Fan-Bao Yao; Hao Chen

    2015-01-01

    Objective:To explore the role of Notch1/2 signaling pathway in the apoptosis process of SGC-7901 induced by oxaliplatin.Methods:The cell viability was detected by CCK8 and the expression of Notch1/2 and Caspase9 was detected by Western Blotting before and after treatment of oxaliplatin.Results:Oxaliplatin medication decreased the viability of SCG-7901 and increased the Notch1/2 as well as Caspase9 expression. Notch signaling pathway inhibitor L685458 normalized those abnormalities greatly.Conclusion: Oxaliplatin promotes SGC-7901 apoptosis by activating Notch signaling pathway and up-regulating Caspase9 protein.

  7. Overexpression of protein O-fucosyltransferase 1 accelerates hepatocellular carcinoma progression via the Notch signaling pathway.

    Science.gov (United States)

    Ma, Lijie; Dong, Pingping; Liu, Longzi; Gao, Qiang; Duan, Meng; Zhang, Si; Chen, She; Xue, Ruyi; Wang, Xiaoying

    2016-04-29

    Aberrant activation of Notch signaling frequently occurs in liver cancer, and is associated with liver malignancies. However, the mechanisms regulating pathologic Notch activation in hepatocellular carcinoma (HCC) remain unclear. Protein O-fucosyltransferase 1 (Pofut1) catalyzes the addition of O-linked fucose to the epidermal growth factor-like repeats of Notch. In the present study, we detected the expression of Pofut1 in 8 HCC cell lines and 253 human HCC tissues. We reported that Pofut1 was overexpressed in HCC cell lines and clinical HCC tissues, and Pofut1 overexpression clinically correlated with the unfavorable survival and high disease recurrence in HCC. The in vitro assay demonstrated that Pofut1 overexpression accelerated the cell proliferation and migration in HCC cells. Furthermore, Pofut1 overexpression promoted the binding of Notch ligand Dll1 to Notch receptor, and hence activated Notch signaling pathway in HCC cells, indicating that Pofut1 overexpression could be a reason for the aberrant activation of Notch signaling in HCC. Taken together, our findings indicated that an aberrant activated Pofut1-Notch pathway was involved in HCC progression, and blockage of this pathway could be a promising strategy for the therapy of HCC. PMID:27003260

  8. Notch signaling induces rapid degradation of achaete-scute homolog 1.

    Science.gov (United States)

    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.

  9. Trastuzumab Resistance: Role for Notch Signaling

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    Kinnari Mehta

    2009-01-01

    Full Text Available Epidermal growth factor receptor-2 (ErbB-2/HER2 is a potent breast oncogene that has been shown to be amplified in 20% of breast cancers. Overexpression of ErbB-2 predicts for aggressive tumor behavior, resistance to some cytotoxic and antihormonal therapies, and poor overall survival. Trastuzumab, the humanized, monoclonal antibody directed against ErbB-2 has shown tremendous efficacy and improved overall survival for women when combined with a taxane-based chemotherapy. However, resistance to trastuzumab remains a major concern, most notably in women with metastatic breast cancer. Numerous mechanisms that include overexpression of alternate receptor tyrosine kinases and/or loss of critical tumor suppressors have been proposed in the last several years to elucidate trastuzumab resistance. Here we review the many possible mechanisms of action that could contribute to resistance, and novel therapies to prevent or reverse the resistant phenotype. Moreover, we provide a critical role for Notch signaling cross-talk with overlapping or new signaling networks in trastuzumab-resistant breast.

  10. Role of Wnt and Notch signaling in regulating hair cell regeneration in the cochlea.

    Science.gov (United States)

    Waqas, Muhammad; Zhang, Shasha; He, Zuhong; Tang, Mingliang; Chai, Renjie

    2016-09-01

    Sensory hair cells in the inner ear are responsible for sound recognition. Damage to hair cells in adult mammals causes permanent hearing impairment because these cells cannot regenerate. By contrast, newborn mammals possess limited regenerative capacity because of the active participation of various signaling pathways, including Wnt and Notch signaling. The Wnt and Notch pathways are highly sophisticated and conserved signaling pathways that control multiple cellular events necessary for the formation of sensory hair cells. Both signaling pathways allow resident supporting cells to regenerate hair cells in the neonatal cochlea. In this regard, Wnt and Notch signaling has gained increased research attention in hair cell regeneration. This review presents the current understanding of the Wnt and Notch signaling pathways in the auditory portion of the inner ear and discusses the possibilities of controlling these pathways with the hair cell fate determiner Atoh1 to regulate hair cell regeneration in the mammalian cochlea. PMID:27527363

  11. Akt1 mediates neuronal differentiation in zebrafish via a reciprocal interaction with notch signaling.

    Directory of Open Access Journals (Sweden)

    Yi-Chuan Cheng

    Full Text Available Akt1 is well known for its role in regulating cell proliferation, differentiation, and apoptosis and is implicated in tumors and several neurological disorders. However, the role of Akt1 in neural development has not been well defined. We have isolated zebrafish akt1 and shown that this gene is primarily transcribed in the developing nervous system, and its spatiotemporal expression pattern suggests a role in neural differentiation. Injection of akt1 morpholinos resulted in loss of neuronal precursors with a concomitant increase in post-mitotic neurons, indicating that knockdown of Akt1 is sufficient to cause premature differentiation of neurons. A similar phenotype was observed in embryos deficient for Notch signaling. Both the ligand (deltaA and the downstream target of Notch (her8a were downregulated in akt1 morphants, indicating that Akt1 is required for Delta-Notch signaling. Furthermore, akt1 expression was downregulated in Delta-Notch signaling-deficient embryos and could be induced by constitutive activation of Notch signaling. In addition, knockdown of Akt1 was able to nullify the inhibition of neuronal differentiation caused by constitutive activation of Notch signaling. Taken together, these results provide in vivo evidence that Akt1 interacts with Notch signaling reciprocally and provide an explanation of why Akt1 is essential for the inhibition of neuronal differentiation.

  12. NOTCH1 signaling promotes human T-cell acute lymphoblastic leukemia initiating cell regeneration in supportive niches.

    Directory of Open Access Journals (Sweden)

    Wenxue Ma

    Full Text Available BACKGROUND: Leukemia initiating cells (LIC contribute to therapeutic resistance through acquisition of mutations in signaling pathways, such as NOTCH1, that promote self-renewal and survival within supportive niches. Activating mutations in NOTCH1 occur commonly in T cell acute lymphoblastic leukemia (T-ALL and have been implicated in therapeutic resistance. However, the cell type and context specific consequences of NOTCH1 activation, its role in human LIC regeneration, and sensitivity to NOTCH1 inhibition in hematopoietic microenvironments had not been elucidated. METHODOLOGY AND PRINCIPAL FINDINGS: We established humanized bioluminescent T-ALL LIC mouse models transplanted with pediatric T-ALL samples that were sequenced for NOTCH1 and other common T-ALL mutations. In this study, CD34(+ cells from NOTCH1(Mutated T-ALL samples had higher leukemic engraftment and serial transplantation capacity than NOTCH1(Wild-type CD34(+ cells in hematopoietic niches, suggesting that self-renewing LIC were enriched within the NOTCH1(Mutated CD34(+ fraction. Humanized NOTCH1 monoclonal antibody treatment reduced LIC survival and self-renewal in NOTCH1(Mutated T-ALL LIC-engrafted mice and resulted in depletion of CD34(+CD2(+CD7(+ cells that harbor serial transplantation capacity. CONCLUSIONS: These results reveal a functional hierarchy within the LIC population based on NOTCH1 activation, which renders LIC susceptible to targeted NOTCH1 inhibition and highlights the utility of NOTCH1 antibody targeting as a key component of malignant stem cell eradication strategies.

  13. Notch Signaling Mediates Skeletal Muscle Atrophy in Cancer Cachexia Caused by Osteosarcoma

    OpenAIRE

    Mu, Xiaodong; Agarwal, Rashmi; March, Daniel; Rothenberg, Adam; Voigt, Clifford; Tebbets, Jessica; Huard, Johnny; Weiss, Kurt

    2016-01-01

    Skeletal muscle atrophy in cancer cachexia is mediated by the interaction between muscle stem cells and various tumor factors. Although Notch signaling has been known as a key regulator of both cancer development and muscle stem cell activity, the potential involvement of Notch signaling in cancer cachexia and concomitant muscle atrophy has yet to be elucidated. The murine K7M2 osteosarcoma cell line was used to generate an orthotopic model of sarcoma-associated cachexia, and the role of Notc...

  14. Notch activation by phenethyl isothiocyanate attenuates its inhibitory effect on prostate cancer cell migration.

    Directory of Open Access Journals (Sweden)

    Su-Hyeong Kim

    Full Text Available Phenethyl isothiocyanate (PEITC is a promising cancer chemopreventive component of edible cruciferous vegetables with in vivo efficacy against prostate cancer in experimental rodents. Cancer chemopreventive response to PEITC is characterized by its ability to inhibit multiple oncogenic signaling pathways, including nuclear factor-κB, Akt, and androgen receptor. The present study demonstrates, for the first time, that PEITC treatment activates Notch signaling in malignant as well as normal human prostate cells. Exposure of human prostate cancer cells (LNCaP, PC-3, and DU145 and a normal human prostate epithelial cell line (PrEC to PEITC resulted in cleavage (active form of Notch1 and Notch2, and increased transcriptional activity of Notch. In PC-3 and LNCaP cells, PEITC treatment caused induction of Notch ligands Jagged1 and Jagged2 (PC-3, overexpression of γ-secretase complex components Presenilin1 and Nicastrin (PC-3, nuclear enrichment of cleaved Notch2, and/or up-regulation of Notch1, Notch2, Jagged1, and/or Jagged2 mRNA. PEITC-induced apoptosis in LNCaP and PC-3 cells was significantly attenuated by RNA interference of Notch2, but not by pharmacological inhibition of Notch1. Inhibition of PC-3 and LNCaP cell migration resulting from PEITC exposure was significantly augmented by knockdown of Notch2 protein as well as pharmacological inhibition of Notch1 activation. Nuclear expression of cleaved Notch2 protein was significantly higher in PC-3 xenografts from PEITC-treated mice and dorsolateral prostates from PEITC-fed TRAMP mice compared with respective control. Because Notch signaling is implicated in epithelial-mesenchymal transition and metastasis, the present study suggests that anti-metastatic effect of PEITC may be augmented by a combination regimen involving a Notch inhibitor.

  15. Inhibition of Notch signaling promotes browning of white adipose tissue and ameliorates obesity.

    Science.gov (United States)

    Bi, Pengpeng; Shan, Tizhong; Liu, Weiyi; Yue, Feng; Yang, Xin; Liang, Xin-Rong; Wang, Jinghua; Li, Jie; Carlesso, Nadia; Liu, Xiaoqi; Kuang, Shihuan

    2014-08-01

    Beige adipocytes in white adipose tissue (WAT) are similar to classical brown adipocytes in that they can burn lipids to produce heat. Thus, an increase in beige adipocyte content in WAT browning would raise energy expenditure and reduce adiposity. Here we report that adipose-specific inactivation of Notch1 or its signaling mediator Rbpj in mice results in browning of WAT and elevated expression of uncoupling protein 1 (Ucp1), a key regulator of thermogenesis. Consequently, as compared to wild-type mice, Notch mutants exhibit elevated energy expenditure, better glucose tolerance and improved insulin sensitivity and are more resistant to high fat diet-induced obesity. By contrast, adipose-specific activation of Notch1 leads to the opposite phenotypes. At the molecular level, constitutive activation of Notch signaling inhibits, whereas Notch inhibition induces, Ppargc1a and Prdm16 transcription in white adipocytes. Notably, pharmacological inhibition of Notch signaling in obese mice ameliorates obesity, reduces blood glucose and increases Ucp1 expression in white fat. Therefore, Notch signaling may be therapeutically targeted to treat obesity and type 2 diabetes.

  16. Optical notch filter design based on digital signal processing

    Institute of Scientific and Technical Information of China (English)

    GUO Sen; ZHANG Juan; LI Xue

    2011-01-01

    Based on digital signal processing theory, a novel method of designing optical notch filter is proposed for Mach-Zehnder interferometer with cascaded optical fiber rings coupled structure. The method is simple and effective, and it can be used to implement the designing of the optical notch filter which has arbitrary number of notch points in one free spectrum range (FSR). A design example of notch filter based on cascaded single-fiber-rings is given. On this basis, an improved cascaded double-fiber-rings structure is presented to eliminate the effect of phase shift caused by the single-fiber-ring structure. This new structure can improve the stability and applicability of system. The change of output intensity spectrum is finally investigated for each design parameter and the tuning characteristics of the notch filter are also discussed.

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

    Science.gov (United States)

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

    2016-04-19

    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

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

    Science.gov (United States)

    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

  19. Notch signaling in group 3 innate lymphoid cells modulates their plasticity.

    Science.gov (United States)

    Chea, Sylvestre; Perchet, Thibaut; Petit, Maxime; Verrier, Thomas; Guy-Grand, Delphine; Banchi, Elena-Gaia; Vosshenrich, Christian A J; Di Santo, James P; Cumano, Ana; Golub, Rachel

    2016-01-01

    The Notch signaling pathway is conserved throughout evolution, and it controls various processes, including cell fate determination, differentiation, and proliferation. Innate lymphoid cells (ILCs) are lymphoid cells lacking antigen receptors that fulfill effector and regulatory functions in innate immunity and tissue remodeling. Type 3 ILCs (ILC3s) reinforce the epithelial barrier and maintain homeostasis with intestinal microbiota. We demonstrated that the population of natural cytotoxicity receptor-positive (NCR(+)) ILC3s in mice is composed of two subsets that have distinct developmental requirements. A major subset depended on the activation of Notch2 in NCR(-) ILC3 precursors in the lamina propria of the small intestine to stimulate expression of the genes encoding the transcription factors T-bet, RORγt, and aryl hydrocarbon receptor (AhR). Notch signaling contributed to the transition of NCR(-) cells into NCR(+) cells, the more proinflammatory subset, in a cell-autonomous manner. In the absence of Notch signaling, this subset of NCR(-) ILC3s did not acquire the gene expression profile of NCR(+) ILC3s. A second subset of NCR(+) ILC3s did not depend on Notch for their development or for increased transcription factor abundance; however, their production of cytokines and cell surface abundance of NCRs were decreased in the absence of Notch signaling. Together, our data suggest that Notch is a regulator of the plasticity of ILC3s by controlling NCR(+) cell fate. PMID:27141929

  20. Immunohistochemical expression of aberrant Notch-1 signaling in vitiligo: an implication for pathogenesis.

    Science.gov (United States)

    Seleit, Iman; Bakry, Ola Ahmed; Abdou, Asmaa Gaber; Dawoud, Noha Mohammed

    2014-06-01

    The etiopathogenetic mechanisms leading to pigment loss in vitiligo are not fully understood. Notch signaling is required for development and maintenance of melanocyte lineage and acts as a key component among keratinocyte-melanocyte interactions. The current study aimed to investigate the possible role of Notch signaling and its effect on the whole melanocyte lineage in vitiligo and correlating it with the different clinicopathologic parameters. Using immunohistochemical technique, Notch-1 expression was evaluated in 50 lesional and 20 perilesional biopsies of patients with vitiligo in comparison with 20 normal skin biopsies as a control group. Lesional biopsies were stained with human melanoma black-45 and tyrosinase-related protein-2 to demonstrate the melanocyte lineage. Membranous and/or nuclear expression of Notch-1 was in favor of control and perilesional skin, whereas cytoplasmic expression appeared only in vitiliginous lesions (P vitiligo were associated with mild to moderate Notch-1 intensity, whereas generalized vitiligo was associated with strong intensity of expression (P = .02). In conclusion, Notch-1 signaling is inactivated in vitiligo with consequent loss of epidermal and/or follicular active melanocytes. Aberrant Notch signaling in vitiliginous white hair and acral and segmental vitiligo may be the cause of their treatment resistance.

  1. Sequential Notch signalling at the boundary of fringe expressing and non-expressing cells.

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    Tobias Troost

    Full Text Available Wing development in Drosophila requires the activation of Wingless (Wg in a small stripe along the boundary of Fringe (Fng expressing and non-expressing cells (FB, which coincides with the dorso-ventral (D/V boundary of the wing imaginal disc. The expression of Wg is induced by interactions between dorsal and ventral cells mediated by the Notch signalling pathway. It appears that mutual signalling from dorsal to ventral and ventral to dorsal cells by the Notch ligands Serrate (Ser and Delta (Dl respectively establishes a symmetric domain of Wg that straddles the D/V boundary. The directional signalling of these ligands requires the modification of Notch in dorsal cells by the glycosyltransferase Fng and is based on the restricted expression of the ligands with Ser expression to the dorsal and that of Dl to the ventral side of the wing anlage. In order to further investigate the mechanism of Notch signalling at the FB, we analysed the function of Fng, Ser and Dl during wing development at an ectopic FB and at the D/V boundary. We find that Notch signalling is initiated in an asymmetric fashion on only one side of the FB. During this initial asymmetric phase, only one ligand is required, with Ser initiating Notch-signalling at the D/V and Dl at the ectopic FB. Furthermore, our analysis suggests that Fng has also a positive effect on Ser signalling. Because of these additional properties, differential expression of the ligands, which has been a prerequisite to restrict Notch activation to the FB in the current model, is not required to restrict Notch signalling to the FB.

  2. Regulation of osteoprotegerin expression by Notch signaling in human oral squamous cell carcinoma cell line

    Institute of Scientific and Technical Information of China (English)

    Jeeranan Manokawinchoke; Thanaphum Osathanon; Prasit Pavasant

    2016-01-01

    Objective: To investigate the influence of Notch signaling on osteoprotegerin (OPG) expression in a human oral squamous cell carcinoma cell line. Methods: Activation of Notch signaling was performed by seeding cells on Jagged1 immobilized surfaces. In other experiments, a γ-secretase inhibitor was added to the culture medium to inhibit intracellular Notch signaling. OPG mRNA and protein were determined by real-time PCR and ELISA, respectively. Finally, publicly available microarray database analysis was performed using connection up- or down-regulation expression analysis of microarrays software. Results: Jagged1-treatment of HSC-4 cells enhanced HES1 and HEY1 mRNA expres-sion, confirming the intracellular activation of Notch signaling. OPG mRNA and protein levels were significantly suppressed upon Jagged1 treatment. Correspondingly, HSC-4 cells treated with a γ-secretase inhibitor resulted in a significant reduction of HES1 and HEY1 mRNA levels, and a marked increase in OPG protein expression was observed. These results implied that Notch signaling regulated OPG expression in HSC-4 cells. However, Jagged1 did not alter OPG expression in another human oral squamous cell carcinoma cell line (HSC-5) or a human head and neck squamous cell carcinoma cell line (HN22). Conclusions: Notch signaling regulated OPG expression in an HSC-4 cell line and this mechanism could be cell line specific.

  3. Oncogenic programmes and Notch activity: an 'organized crime'?

    Science.gov (United States)

    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

  4. Oncogenic programmes and Notch activity: an 'organized crime'?

    Science.gov (United States)

    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'.

  5. Notch signaling mediates the age-associated decrease in adhesion of germline stem cells to the niche.

    Directory of Open Access Journals (Sweden)

    Chen-Yuan Tseng

    2014-12-01

    Full Text Available Stem cells have an innate ability to occupy their stem cell niche, which in turn, is optimized to house stem cells. Organ aging is associated with reduced stem cell occupancy in the niche, but the mechanisms involved are poorly understood. Here, we report that Notch signaling is increased with age in Drosophila female germline stem cells (GSCs, and this results in their removal from the niche. Clonal analysis revealed that GSCs with low levels of Notch signaling exhibit increased adhesiveness to the niche, thereby out-competing their neighbors with higher levels of Notch; adhesiveness is altered through regulation of E-cadherin expression. Experimental enhancement of Notch signaling in GSCs hastens their age-dependent loss from the niche, and such loss is at least partially mediated by Sex lethal. However, disruption of Notch signaling in GSCs does not delay GSC loss during aging, and nor does it affect BMP signaling, which promotes self-renewal of GSCs. Finally, we show that in contrast to GSCs, Notch activation in the niche (which maintains niche integrity, and thus mediates GSC retention is reduced with age, indicating that Notch signaling regulates GSC niche occupancy both intrinsically and extrinsically. Our findings expose a novel role of Notch signaling in controlling GSC-niche adhesion in response to aging, and are also of relevance to metastatic cancer cells, in which Notch signaling suppresses cell adhesion.

  6. Role of Notch signalling pathway in cancer and its association with DNA methylation

    Indian Academy of Sciences (India)

    Madhuri G. S. Aithal; Narayanappa Rajeswari

    2013-12-01

    The Notch signalling pathway is an evolutionarily conserved cell signalling pathway involved in the development of organisms as diverse as humans and fruit flies. It plays a pivotal role in cell fate determination. Dysregulated Notch signalling is oncogenic, inhibits apoptosis and promotes cell survival. Abnormal Notch signalling is seen in many cancers like T-cell acute lymphoblastic leukaemia, acute myeloid leukaemia and cancers of the breast, cervix, colon, pancreas, skin and brain. Inhibition of Notch signalling leads to growth arrest and differentiation in those cells in which Notch pathway is activated and this represents a new target for cancer therapy. Cancer develops from genome defects, including both genetic and epigenetic alterations. Epigenetics deals with heritable changes in gene function that occur without a change in the DNA sequence. Among various epigenetic alterations such as acetylation, phosphorylation, ubiquitylation and sumoylation, promoter region methylation is considered as an important component in cancer development. Epigenetic alterations can be used as biomarkers in screening, detection, diagnosis, staging and risk stratification of various cancers. DNA methylation can be therapeutically reversed and demethylating drugs have proven to be promising in cancer treatment. This review focusses on the methylation status of genes in Notch signalling pathway from various cancers and how this epigenetic alteration can be used as a biomarker for cancer diagnosis and subsequent treatment.

  7. Tumor-Suppressive Activity of Lunatic Fringe in Prostate through Differential Modulation of Notch Receptor Activation

    Directory of Open Access Journals (Sweden)

    Shubing Zhang

    2014-02-01

    Full Text Available Elevated Notch ligand and receptor expression has been associated with aggressive forms of prostate cancer, suggesting a role for Notch signaling in regulation of prostate tumor initiation and progression. Here, we report a critical role for Lunatic Fringe (Lfng, which encodes an O-fucosylpeptide 3-ß-N-acetylglucosaminyltransferase known to modify epidermal growth factor repeats of Notch receptor proteins, in regulation of prostate epithelial differentiation and proliferation, as well as in prostate tumor suppression. Deletion of Lfng in mice caused altered Notch activation in the prostate, associated with elevated accumulation of Notch1, Notch2, and Notch4 intracellular domains, decreased levels of the putative Notch3 intracellular fragment, as well as increased expression of Hes1, Hes5, and Hey2. Loss of Lfng resulted in expansion of the basal layer, increased proliferation of both luminal and basal cells, and ultimately, prostatic intraepithelial neoplasia. The Lfng-null prostate showed down-regulation of prostatic tumor suppressor gene NKX3.1 and increased androgen receptor expression. Interestingly, expression of LFNG and NKX3.1 were positively correlated in publically available human prostate cancer data sets. Knockdown of LFNG in DU-145 prostate cancer cells led to expansion of CD44+CD24− and CD49f+CD24− stem/progenitor-like cell population associated with enhanced prostatosphere-forming capacity. Taken together, these data revealed a tumor-suppressive role for Lfng in the prostate through differential regulation of Notch signaling.

  8. Notch1 regulated autophagy controls survival and suppressor activity of activated murine T-regulatory cells

    Science.gov (United States)

    Marcel, Nimi; Sarin, Apurva

    2016-01-01

    Cell survival is one of several processes regulated by the Notch pathway in mammalian cells. Here we report functional outcomes of non-nuclear Notch signaling to activate autophagy, a conserved cellular response to nutrient stress, regulating survival in murine natural T-regulatory cells (Tregs), an immune subset controlling tolerance and inflammation. Induction of autophagy required ligand-dependent, Notch intracellular domain (NIC) activity, which controlled mitochondrial organization and survival of activated Tregs. Consistently, NIC immune-precipitated Beclin and Atg14, constituents of the autophagy initiation complex. Further, ectopic expression of an effector of autophagy (Atg3) or recombinant NIC tagged to a nuclear export signal (NIC-NES), restored autophagy and suppressor function in Notch1-/- Tregs. Furthermore, Notch1 deficiency in the Treg lineage resulted in immune hyperactivity, implicating Notch activity in Treg homeostasis. Notch1 integration with autophagy, revealed in these experiments, holds implications for Notch regulated cell-fate decisions governing differentiation. DOI: http://dx.doi.org/10.7554/eLife.14023.001 PMID:27267497

  9. Notch信号调节外周T细胞的活化、增殖与分化%Notch signaling regulates activation, proliferation and differentiation of peripheral T cells

    Institute of Scientific and Technical Information of China (English)

    唐晓燕; 季晓辉

    2008-01-01

    The differentiation of naive T cells to effector/memory T cells is regulated by a variety of factors. The recent advance of the contribution of Notch signaling in this differentiation step has provided a new path for better understanding the acquisition or persistence of the effector function of mature T cells. A growing body of literature indicates that the Notch pathway can influence the development of T cells in central immune organs. It is now clear that Notch' s ability to regulate cell-fate choices extends into the peripheral immune system, where the activation of the Notch signaling pathway can profoundly alter cytokine production in both CD4+ and CD8+T cells. In this review, we summarized the emerging and, in some points, conflicting evi-dences for Notch signaling on mature T cell activation, proliferation and differentiation. Although the effect of Notch ligation on CD4 + T cell cytokine production varies significantly from one report to another, it is clear that the Notch pathway is an important regulator of T cell activity. Specifically, the available data demonstrated that APCs utilize the Notch pathway to instruct T cell differentiation programs.%初始T细胞分化为效应T和记忆T细胞受到多种因素调节.最近在Notch信号途径的研究进展显示它也参于T细胞的活化与分化.大量研究已经表明Notch信号途径可以影响T细胞在中枢免疫器官的发育,现在关于它调节外周T细胞的分化状态也积累不少证据,Notch信号活化之后能够改变CD4+和CD8+T细胞分泌细胞因子的特点.以下着重介绍Notch信号参于调节外周T细胞的活化、增殖和分化的最新资料,尽管不同的研究者所得实验结果有冲突之处,但已经提示Notch信号在T细胞外周发育中的重要意义,特别重要的是抗原递呈细胞(APC)可以通过Notch信号途径调节T细胞的分化.

  10. Notch inhibits Yorkie activity in Drosophila wing discs.

    Directory of Open Access Journals (Sweden)

    Alexandre Djiane

    Full Text Available During development, tissues and organs must coordinate growth and patterning so they reach the right size and shape. During larval stages, a dramatic increase in size and cell number of Drosophila wing imaginal discs is controlled by the action of several signaling pathways. Complex cross-talk between these pathways also pattern these discs to specify different regions with different fates and growth potentials. We show that the Notch signaling pathway is both required and sufficient to inhibit the activity of Yorkie (Yki, the Salvador/Warts/Hippo (SWH pathway terminal transcription activator, but only in the central regions of the wing disc, where the TEAD factor and Yki partner Scalloped (Sd is expressed. We show that this cross-talk between the Notch and SWH pathways is mediated, at least in part, by the Notch target and Sd partner Vestigial (Vg. We propose that, by altering the ratios between Yki, Sd and Vg, Notch pathway activation restricts the effects of Yki mediated transcription, therefore contributing to define a zone of low proliferation in the central wing discs.

  11. Effects of Linker Length and Transient Secondary Structure Elements in the Intrinsically Disordered Notch RAM Region on Notch Signaling.

    Science.gov (United States)

    Sherry, Kathryn P; Johnson, Scott E; Hatem, Christine L; Majumdar, Ananya; Barrick, Doug

    2015-11-01

    Formation of the bivalent interaction between the Notch intracellular domain (NICD) and the transcription factor CBF-1/RBP-j, Su(H), Lag-1 (CSL) is a key event in Notch signaling because it switches Notch-responsive genes from a repressed state to an activated state. Interaction of the intrinsically disordered RBP-j-associated molecule (RAM) region of NICD with CSL is thought to both disrupt binding of corepressor proteins to CSL and anchor NICD to CSL, promoting interaction of the ankyrin domain of NICD with CSL through an effective concentration mechanism. To quantify the role of disorder in the RAM linker region on the effective concentration enhancement of Notch transcriptional activation, we measured the effects of linker length variation on activation. The resulting activation profile has general features of a worm-like chain model for effective concentration. However, deviations from the model for short sequence deletions suggest that RAM contains sequence-specific structural elements that may be important for activation. Structural characterization of the RAM linker with sedimentation velocity analytical ultracentrifugation and NMR spectroscopy reveals that the linker is compact and contains three transient helices and two extended and dynamic regions. To test if these secondary structure elements are important for activation, we made sequence substitutions to change the secondary structure propensities of these elements and measured transcriptional activation of the resulting variants. Substitutions to two of these nonrandom elements (helix 2, extended region 1) have effects on activation, but these effects do not depend on the nature of the substituting residues. Thus, the primary sequences of these elements, but not their secondary structures, are influencing signaling.

  12. Nas transgenic mouse line allows visualization of Notch pathway activity in vivo

    Science.gov (United States)

    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

  13. Estrogen improves the proliferation and differentiation of hBMSCs derived from postmenopausal osteoporosis through notch signaling pathway.

    Science.gov (United States)

    Fan, Jin-Zhu; Yang, Liu; Meng, Guo-Lin; Lin, Yan-shui; Wei, Bo-Yuan; Fan, Jing; Hu, Hui-Min; Liu, Yan-Wu; Chen, Shi; Zhang, Jin-Kang; He, Qi-Zhen; Luo, Zhuo-Jing; Liu, Jian

    2014-07-01

    Estrogen deficiency is the main reason of bone loss, leading to postmenopausal osteoporosis, and estrogen replacement therapy (ERT) has been demonstrated to protect bone loss efficiently. Notch signaling controls proliferation and differentiation of bone marrow-derived mesenchymal stem cells (BMSCs). Moreover, imperfect estrogen-responsive elements (EREs) were found in the 5'-untranslated region of Notch1 and Jagged1. Thus, we examined the molecular and biological links between estrogen and the Notch signaling in postmenopausal osteoporosis in vitro. hBMSCs were obtained from healthy women and patients with postmenopausal osteoporosis. Notch signaling molecules were quantified using real-time polymerase chain reaction (real-time PCR) and Western Blot. Luciferase reporter constructs with putative EREs were transfected into hBMSCs and analyzed. hBMSCs were transduced with lentiviral vectors containing human Notch1 intracellular domain (NICD1). We also used N-[N-(3, 5-diflurophenylacetate)-l-alanyl]-(S)-phenylglycine t-butyl ester, a γ-secretase inhibitor, to suppress the Notch signaling. We found that estrogen enhanced the Notch signaling in hBMSCs by promoting the expression of Jagged1. hBMSCs cultured with estrogen resulted in the up-regulation of Notch signaling and increased proliferation and differentiation. Enhanced Notch signaling could enhance the proliferation and differentiation of hBMSCs from patients with postmenopausal osteoporosis (OP-hBMSCs). Our results demonstrated that estrogen preserved bone mass partly by activating the Notch signaling. Because long-term ERT has been associated with several side effects, the Notch signaling could be a potential target for treating postmenopausal osteoporosis.

  14. Notch signaling in Drosophila long-term memory formation

    OpenAIRE

    Ge, Xuecai; Hannan, Frances; Xie, Zuolei; Feng, Chunhua; Tully, Tim; Zhou, Haimeng; Xie, Zuoping; Zhong, Yi

    2004-01-01

    Notch (N) is a cell surface receptor that mediates an evolutionarily ancient signaling pathway to control an extraordinarily broad spectrum of cell fates and developmental processes. To gain insights into the functions of N signaling in the adult brain, we examined the involvement of N in Drosophila olfactory learning and memory. Long-term memory (LTM) was disrupted by blocking N signaling in conditional mutants or by acutely induced expression of a dominant-negative N transgene. In contrast,...

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

    Science.gov (United States)

    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

  16. Bevacizumab modulates retinal pigment epithelial-tomesenchymal transition via regulating Notch signaling

    Institute of Scientific and Technical Information of China (English)

    Jing-Jing; Zhang; San-Jun; Chu; Xiao-Lei; Sun; Ting; Zhang; Wei-Yun; Shi

    2015-01-01

    AIM: To investigate the effect of bevacizumab treatment on Notch signaling and the induction of epithelial-of-mesenchymal transition(EMT) in human retinal pigment epithelial cells(ARPE-19) in vitro.METHODS: In vitro cultivated ARPE-19 cells were treated with 0.25 mg/m L bevacizumab for 12, 24, and 48 h.Cell morphology changes were observed under an inverted microscope. The expression of zonula occludens-1(ZO-1), vimentin and Notch-1 intracellular domain(NICD) was examined by immunofluorescence.The m RNA levels of ZO-1, α-SMA, Notch-1, Notch-2,Notch-4, Dll4, Jagged-1, RBP-Jk and Hes-1 expression were evaluated with quantitative real-time polymerase chain reaction(q RT-PCR). The protein levels of α-SMA,NICD, Hes-1 and Dll-4 expression were examined with Western blot.RESULTS: Bevacizumab stimulation increased the expression of α-SMA and vimentin in ARPE-19 cells which changed into spindle-shaped fibroblast-like cells.Meanwhile, the m RNA expression of Hes-1 increased and the protein expression of Hes-1 and NICD also increased, which Notch signaling was activated. The m RNA expression of Notch-1, Jagged-1 and RBP-Jk increased at 48 h, and while Dll4 m RNA and protein expression did not change after bevacizumab treatment.CONCLUSION: Jagged-1/Notch-1 signaling may play a critical role in bevacizumab-induced EMT in ARPE-19 cells, which provides a novel insight into the pathogenesis of intravitreal bevacizumab-associated complication.

  17. Activation of Notch1 Signaling Pathway in Esophageal Squamous Cell Carcinoma and Its Effect on Cell Cycle%Notch1信号途径在食管鳞癌细胞中的激活及对细胞周期的影响

    Institute of Scientific and Technical Information of China (English)

    许培荣; 范天黎; 刘冲; 鲁照明; 刘红涛; 巩天晓; 薛乐勋

    2009-01-01

    Objective To investigate the active status of Notch1 signaling pathway in esophageal squamous cell carcinoma (ESCC) and its effect on cell cycle. Methods The expression of Notch1 gene was detected by immunocytochemistry in EC9706 cells, and the active status of Notch1 signaling pathway was investigated by immunoflurescence. In addition, cell proliferation assay was performed using CCK-8 Kit. Proteins and mRNA of the genes related to cell cycle was studied by Western blot and RT-PCR techniques.Finally, cell cycle distribution was measured by flow cytometry (FCM). Results The expression of Notch1 gene was found in EC9706 cells transfected with pcNICD. Besides, the result of immunoflurecence revealed that Notch1 appeared to be expressed in the cytosol and nucleus, implying an activated status. EC9706 cells had an obvious decreased growth rate compared to the control EC9706 cells and EC9706 cells transfected with pcDNA3.1 (P<0.01). Furthermore, the mRNA and proteins expressions of the CDK2, cyclin D1 and cyclin E genes were significantly decreased in the EC9706 cells transfected with pcNICD compared to those of the cells untreated and transfected with pcDNA3.1. There were higher proportions of cells (74.5%, P<0.05) in EC9706 cells transfected with pcNICD at G_0/G_1 phase than that in cells untreated (59.1%) and transfected with pcDNA3.1 (59.0%). Cell cycle distribution analysis demonstrated that the cell increased (P<0.05) at G_0/G_1 phase in the cells transiently expressing NICD, which suggested that active Notch1 signaling pathway induces G_0/G_1 cell cycle arrest in EC9706 cells. Conclusion Active Notch1 signaling pathway can obviously inhibit the growth of EC9706 cells,suggesting Notch1 gene may be a new target of treating esophageal squamous cell carcinoma.%目的 观察Notch1信号途径在食管鳞癌EC9706细胞中的激活状态及其对细胞周期的影响.方法 通过免疫细胞化学检测Notch1基因在食管鳞癌细胞株EC9706细胞中的表

  18. The functional role of Notch signaling in human gliomas

    DEFF Research Database (Denmark)

    Stockhausen, Marie-Thérése; Kristoffersen, Karina; Poulsen, Hans Skovgaard

    2010-01-01

    have been referred to as brain cancer stem cells (bCSC), as they share similarities to normal neural stem cells in the brain. The Notch signaling pathway is involved in cell fate decisions throughout normal development and in stem cell proliferation and maintenance. The role of Notch in cancer is now......Gliomas are among the most devastating adult tumors for which there is currently no cure. The tumors are derived from brain glial tissue and comprise several diverse tumor forms and grades. Recent reports highlight the importance of cancer-initiating cells in the malignancy of gliomas. These cells...

  19. Mind bomb1 is a ubiquitin ligase essential for mouse embryonic development and Notch signaling.

    Science.gov (United States)

    Barsi, Julius C; Rajendra, Rashmi; Wu, Jiang I; Artzt, Karen

    2005-10-01

    The Notch-Delta signaling pathway controls many conserved cell determination events. While the Notch end is fairly well characterized, the Delta end remains poorly understood. Mind bomb1 (MIB1) is one of two E3 ligases known to ubiquitinate Delta. We report here that a targeted mutation of Mib1 in mice results in embryonic lethality by E10.5. Mutants exhibit multiple defects due to their inability to modulate Notch signaling. As histopathology revealed a strong neurogenic phenotype, this study concentrates on characterizing the Mib1 mutant by analyzing Notch pathway components in embryonic neuroepithelium prior to developmental arrest. Premature neurons were observed to undergo apoptosis soon after differentiation. Aberrant neurogenesis is a direct consequence of lowered Hes1 and Hes5 expression resulting from the inability to generate Notch1 intracellular domain (NICD1). We conclude that MIB1 activity is required for S3 cleavage of the Notch1 receptor. These results have direct implications for manipulating the differentiation of neuronal stem cells and provide a putative target for the modulation of specific tumors.

  20. Delta-Notch signaling and lateral inhibition in zebrafish spinal cord development

    Directory of Open Access Journals (Sweden)

    Givan Lee Anne

    2001-07-01

    Full Text Available Abstract Background Vertebrate neural development requires precise coordination of cell proliferation and cell specification to guide orderly transition of mitotically active precursor cells into different types of post-mitotic neurons and glia. Lateral inhibition, mediated by the Delta-Notch signaling pathway, may provide a mechanism to regulate proliferation and specification in the vertebrate nervous system. We examined delta and notch gene expression in zebrafish embryos and tested the role of lateral inhibition in spinal cord patterning by ablating cells and genetically disrupting Delta-Notch signaling. Results Zebrafish embryos express multiple delta and notch genes throughout the developing nervous system. All or most proliferative precursors appeared to express notch genes whereas subsets of precursors and post-mitotic neurons expressed delta genes. When we ablated identified primary motor neurons soon after they were born, they were replaced, indicating that specified neurons laterally inhibit neighboring precursors. Mutation of a delta gene caused precursor cells of the trunk neural tube to cease dividing prematurely and develop as neurons. Additionally, mutant embryos had excess early specified neurons, with fates appropriate for their normal positions within the neural tube, and a concomitant deficit of late specified cells. Conclusions Our results are consistent with the idea that zebrafish Delta proteins, expressed by newly specified neurons, promote Notch activity in neighboring precursors. This signaling is required to maintain a proliferative precursor population and generate late-born neurons and glia. Thus, Delta-Notch signaling may diversify vertebrate neural cell fates by coordinating cell cycle control and cell specification.

  1. Angiotensin II contributes to renal fibrosis independently of Notch pathway activation.

    Directory of Open Access Journals (Sweden)

    Carolina Lavoz

    Full Text Available Recent studies have described that the Notch signaling pathway is activated in a wide range of renal diseases. Angiotensin II (AngII plays a key role in the progression of kidney diseases. AngII contributes to renal fibrosis by upregulation of profibrotic factors, induction of epithelial mesenchymal transition and accumulation of extracellular matrix proteins. In cultured human tubular epithelial cells the Notch activation by transforming growth factor-β1 (TGF-β1 has been involved in epithelial mesenchymal transition. AngII mimics many profibrotic actions of TGF-β1. For these reasons, our aim was to investigate whether AngII could regulate the Notch/Jagged system in the kidney, and its potential role in AngII-induced responses. In cultured human tubular epithelial cells, TGF-β1, but not AngII, increased the Notch pathway-related gene expression, Jagged-1 synthesis, and caused nuclear translocation of the activated Notch. In podocytes and renal fibroblasts, AngII did not modulate the Notch pathway. In tubular epithelial cells, pharmacological Notch inhibition did not modify AngII-induced changes in epithelial mesenchymal markers, profibrotic factors and extracellular matrix proteins. Systemic infusion of AngII into rats for 2 weeks caused tubulointerstitial fibrosis, but did not upregulate renal expression of activated Notch-1 or Jagged-1, as observed in spontaneously hypertensive rats. Moreover, the Notch/Jagged system was not modulated by AngII type I receptor blockade in the model of unilateral ureteral obstruction in mice. These data clearly indicate that AngII does not regulate the Notch/Jagged signaling system in the kidney, in vivo and in vitro. Our findings showing that the Notch pathway is not involved in AngII-induced fibrosis could provide important information to understand the complex role of Notch system in the regulation of renal regeneration vs damage progression.

  2. miR-216a regulates snx5, a novel notch signaling pathway component, during zebrafish retinal development.

    Science.gov (United States)

    Olena, Abigail F; Rao, Mahesh B; Thatcher, Elizabeth J; Wu, Shu-Yu; Patton, James G

    2015-04-01

    Precise regulation of Notch signaling is essential for normal vertebrate development. Mind bomb (Mib) is a ubiquitin ligase that is required for activation of Notch by Notch׳s ligand, Delta. Sorting Nexin 5 (SNX5) co-localizes with Mib and Delta complexes and has been shown to directly bind to Mib. We show that microRNA-216a (miR-216a) is expressed in the retina during early development and regulates snx5 to precisely regulate Notch signaling. miR-216a and snx5 have complementary expression patterns. Knocking down miR-216a and/or overexpression of snx5 resulted in increased Notch activation. Conversely, knocking down snx5 and/or miR-216a overexpression caused a decrease in Notch activation. We propose a model in which SNX5, precisely controlled by miR-216a, is a vital partner of Mib in promoting endocytosis of Delta and subsequent activation of Notch signaling.

  3. Faster embryonic segmentation through elevated Delta-Notch signalling.

    Science.gov (United States)

    Liao, Bo-Kai; Jörg, David J; Oates, Andrew C

    2016-01-01

    An important step in understanding biological rhythms is the control of period. A multicellular, rhythmic patterning system termed the segmentation clock is thought to govern the sequential production of the vertebrate embryo's body segments, the somites. Several genetic loss-of-function conditions, including the Delta-Notch intercellular signalling mutants, result in slower segmentation. Here, we generate DeltaD transgenic zebrafish lines with a range of copy numbers and correspondingly increased signalling levels, and observe faster segmentation. The highest-expressing line shows an altered oscillating gene expression wave pattern and shortened segmentation period, producing embryos with more, shorter body segments. Our results reveal surprising differences in how Notch signalling strength is quantitatively interpreted in different organ systems, and suggest a role for intercellular communication in regulating the output period of the segmentation clock by altering its spatial pattern. PMID:27302627

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

    Science.gov (United States)

    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.

  5. Notch-1 activates estrogen receptor-α-dependent transcription via IKKα in breast cancer cells

    Science.gov (United States)

    Hao, L; Rizzo, P; Osipo, C; Pannuti, A; Wyatt, D; Cheung, LW-K; Sonenshein, G; Osborne, BA; Miele, L

    2016-01-01

    Approximately 80% of breast cancers express the estrogen receptor-α (ERα) and are treated with anti-estrogens. Resistance to these agents is a major cause of mortality. We have shown that estrogen inhibits Notch, whereas anti-estrogens or estrogen withdrawal activate Notch signaling. Combined inhibition of Notch and estrogen signaling has synergistic effects in ERα-positive breast cancer models. However, the mechanisms whereby Notch-1 promotes the growth of ERα-positive breast cancer cells are unknown. Here, we demonstrate that Notch-1 increases the transcription of ERα-responsive genes in the presence or absence of estrogen via a novel chromatin crosstalk mechanism. Our data support a model in which Notch-1 can activate the transcription of ERα-target genes via IKKα-dependent cooperative chromatin recruitment of Notch–CSL–MAML1 transcriptional complexes (NTC) and ERα, which promotes the recruitment of p300. CSL binding elements frequently occur in close proximity to estrogen-responsive elements (EREs) in the human and mouse genomes. Our observations suggest that a hitherto unknown Notch-1/ERα chromatin crosstalk mediates Notch signaling effects in ERα-positive breast cancer cells and contributes to regulate the transcriptional functions of ERα itself. PMID:19838210

  6. Fas-Associated Protein with Death Domain Regulates Notch Signaling during Muscle Regeneration.

    Science.gov (United States)

    Zhang, Rong; Wang, Lu; He, Liangqiang; Yang, Bingya; Yao, Chun; Du, Pan; Xu, Qiang; Cheng, Wei; Hua, Zi-Chun

    2014-01-01

    Notch signaling plays critical roles during myogenesis by promoting the proliferation and inhibiting the differentiation of myogenic progenitors. However, the mechanism of the temporal regulation of Notch signaling during the myogenic lineage progression remains elusive. In the present study, we show that a constitutively phosphoryl-mimicking mutation of Fas-associated death domain (FADD-D) enhances Notch-1 signaling and compromises Wnt signaling in both cultured myoblasts and regenerating muscles, which results in inhibited myogenic differentiation and muscle regeneration. Inhibition of Notch signaling recovers the regeneration ability in injured FADD-D muscles through rescuing Wnt signaling. Furthermore, we found that protein kinase Cα mediates FADD-D-induced Notch-1 signaling by stabilizing Notch-1. Collectively, these data identify a novel mechanism for the temporal regulation of Notch signaling during myogenic lineage progression and muscle regeneration. PMID:26303234

  7. Non-small-cell lung carcinoma: role of the Notch signaling pathway

    Directory of Open Access Journals (Sweden)

    Barse L

    2015-06-01

    Full Text Available Levi Barse, Maurizio Bocchetta Department of Pathology, Oncology Institute, Loyola University Chicago, Maywood, IL, USA Abstract: Notch signaling plays a pivotal role during embryogenesis. It regulates three fundamental processes: lateral inhibition, boundary formation, and lineage specification. During post-natal life, Notch receptors and ligands control critical cell fate decisions both in compartments that are undergoing differentiation and in pluripotent progenitor cells. First recognized as a potent oncogene in certain lymphoblastic leukemias and mesothelium-derived tissue, the role of Notch signaling in epithelial, solid tumors has been far more controversial. The overall consequence of Notch signaling and which form of the Notch receptor drives malignancy in humans is deeply debated. Most likely, this is due to the high degree of context-dependent effects of Notch signaling. More recently, it has been discovered that Notch (especially Notch-1 can exert different, even opposite effects in the same tissue under differing microenvironmental conditions. Further complicating the understanding of Notch receptors is the recently discovered role for non-canonical Notch signaling. Additionally, the most frequent Notch signaling antagonists used in biological systems have been inhibitors of the transmembrane protease complex γ-secretase, which itself processes a plethora of class one transmembrane proteins and thus cannot be considered a Notch-specific upstream regulator. Here we review the available empirical evidence gathered in recent years concerning Notch receptors and ligands in non-small-cell lung carcinoma (NSCLC. Although an overview of the field reveals seemingly contradicting results, we propose that Notch signaling can be exploited as a therapeutic target in NSCLC and represents a promising complement to the current arsenal utilized to combat this malignancy, particularly in targeting NSCLC tissues under specific environmental

  8. The hippo pathway promotes Notch signaling in regulation of cell differentiation, proliferation, and oocyte polarity.

    Directory of Open Access Journals (Sweden)

    Jianzhong Yu

    Full Text Available Specification of the anterior-posterior axis in Drosophila oocytes requires proper communication between the germ-line cells and the somatically derived follicular epithelial cells. Multiple signaling pathways, including Notch, contribute to oocyte polarity formation by controlling the temporal and spatial pattern of follicle cell differentiation and proliferation. Here we show that the newly identified Hippo tumor-suppressor pathway plays a crucial role in the posterior follicle cells in the regulation of oocyte polarity. Disruption of the Hippo pathway, including major components Hippo, Salvador, and Warts, results in aberrant follicle-cell differentiation and proliferation and dramatic disruption of the oocyte anterior-posterior axis. These phenotypes are related to defective Notch signaling in follicle cells, because misexpression of a constitutively active form of Notch alleviates the oocyte polarity defects. We also find that follicle cells defective in Hippo signaling accumulate the Notch receptor and display defects in endocytosis markers. Our findings suggest that the interaction between Hippo and classic developmental pathways such as Notch is critical to spatial and temporal regulation of differentiation and proliferation and is essential for development of the body axes in Drosophila.

  9. Mastermind-Like 1 Is Ubiquitinated: Functional Consequences for Notch Signaling.

    Directory of Open Access Journals (Sweden)

    Mozhgan Farshbaf

    Full Text Available Early studies demonstrated the involvement of ubiquitination of the Notch intracellular domain for rapid turnover of the transcriptional complex at Notch target genes. It was shown that this ubiquitination was promoted by the co-activator Mastermind like 1 (MAML1. MAML1 also contains numerous lysine residues that may also be ubiquitinated and necessary for protein regulation. In this study, we show that over-expressed MAML1 is ubiquitinated and identify eight conserved lysine residues which are required for ubiquitination. We also show that p300 stimulates ubiquitination and that Notch inhibits ubiquitination. Furthermore, we show that a mutant MAML1 that has decreased ubiquitination shows increased output from a HES1 reporter gene assay. Therefore, we speculate that ubiquitination of MAML1 might be a mechanism to maintain low levels of the protein until needed for transcriptional activation. In summary, this study identifies that MAML1 is ubiquitinated in the absence of Notch signaling to maintain low levels of MAML1 in the cell. Our data supports the notion that a precise and tight regulation of the Notch pathway is required for this signaling pathway.

  10. Notch signalling in the paraxial mesoderm is most sensitive to reduced Pofut1 levels during early mouse development

    Directory of Open Access Journals (Sweden)

    Serth Jürgen

    2009-01-01

    Full Text Available Abstract Background The evolutionarily conserved Notch signalling pathway regulates multiple developmental processes in a wide variety of organisms. One critical posttranslational modification of Notch for its function in vivo is the addition of O-linked fucose residues by protein O-fucosyltransferase 1 (POFUT1. In addition, POFUT1 acts as a chaperone and is required for Notch trafficking. Mouse embryos lacking POFUT1 function die with a phenotype indicative of global inactivation of Notch signalling. O-linked fucose residues on Notch can serve as substrates for further sugar modification by Fringe (FNG proteins. Notch modification by Fringe differently affects the ability of ligands to activate Notch receptors in a context-dependent manner indicating a complex modulation of Notch activity by differential glycosylation. Whether the context-dependent effects of Notch receptor glycosylation by FNG reflect different requirements of distinct developmental processes for O-fucosylation by POFUT1 is unclear. Results We have identified and characterized a spontaneous mutation in the mouse Pofut1 gene, referred to as "compact axial skeleton" (cax. Cax carries an insertion of an intracisternal A particle retrotransposon into the fourth intron of the Pofut1 gene and represents a hypomorphic Pofut1 allele that reduces transcription and leads to reduced Notch signalling. Cax mutant embryos have somites of variable size, showed partly abnormal Lfng expression and, consistently defective anterior-posterior somite patterning and axial skeleton development but had virtually no defects in several other Notch-regulated early developmental processes outside the paraxial mesoderm that we analyzed. Conclusion Notch-dependent processes apparently differ with respect to their requirement for levels of POFUT1. Normal Lfng expression and anterior-posterior somite patterning is highly sensitive to reduced POFUT1 levels in early mammalian embryos, whereas other early Notch

  11. Monomeric C-reactive protein and Notch-3 co-operatively increase angiogenesis through PI3K signalling pathway.

    Science.gov (United States)

    Boras, Emhamed; Slevin, Mark; Alexander, M Yvonne; Aljohi, Ali; Gilmore, William; Ashworth, Jason; Krupinski, Jerzy; Potempa, Lawrence A; Al Abdulkareem, Ibrahim; Elobeid, Adila; Matou-Nasri, Sabine

    2014-10-01

    C-reactive protein (CRP) is the most acute-phase reactant serum protein of inflammation and a strong predictor of cardiovascular disease. Its expression is associated with atherosclerotic plaque instability and the formation of immature micro-vessels. We have previously shown that CRP upregulates endothelial-derived Notch-3, a key receptor involved in vascular development, remodelling and maturation. In this study, we investigated the links between the bioactive monomeric CRP (mCRP) and Notch-3 signalling in angiogenesis. We used in vitro (cell counting, wound-healing and tubulogenesis assays) and in vivo (chorioallantoic membrane) angiogenic assays and Western blotting to study the angiogenic signalling pathways induced by mCRP and Notch-3 activator chimera protein (Notch-3/Fc). Our results showed an additive effect on angiogenesis of mCRP stimulatory effect combined with Notch-3/Fc promoting bovine aortic endothelial cell (BAEC) proliferation, migration, tube formation in Matrigel(TM) with up-regulation of phospho-Akt expression. The pharmacological blockade of PI3K/Akt survival pathway by LY294002 fully inhibited in vitro and in vivo angiogenesis induced by mCRP/Notch-3/Fc combination while blocking Notch signalling by gamma-secretase inhibitor (DAPT) partially inhibited mCRP/Notch-3/Fc-induced angiogenesis. Using a BAEC vascular smooth muscle cell co-culture sprouting angiogenesis assay and transmission electron microscopy, we showed that activation of both mCRP and Notch-3 signalling induced the formation of thicker sprouts which were shown later by Western blotting to be associated with an up-regulation of N-cadherin expression and a down-regulation of VE-cadherin expression. Thus, mCRP combined with Notch-3 activator promote angiogenesis through the PI3K/Akt pathway and their therapeutic combination has potential to promote and stabilize vessel formation whilst reducing the risk of haemorrhage from unstable plaques. PMID:24972386

  12. Targeting Notch signaling pathway in cancer: Clinical development advances and challenges

    OpenAIRE

    Takebe, Naoko; Nguyen, Dat; Yang, Sherry X

    2013-01-01

    Notch signaling plays an important role in development and cell fate determination, and it is deregulated in human hematologic malignancies and solid tumors. This review includes a brief introduction of the relevant pathophysiology of Notch signaling pathway and primarily focuses on the clinical development of promising agents that either obstruct Notch receptor cleavages such as γ-secretase inhibitors (GSIs) or interfere with the Notch ligand–receptor interaction by monoclonal antibodies (mA...

  13. Lhx2 Is an Essential Factor for Retinal Gliogenesis and Notch Signaling.

    Science.gov (United States)

    de Melo, Jimmy; Zibetti, Cristina; Clark, Brian S; Hwang, Woochang; Miranda-Angulo, Ana L; Qian, Jiang; Blackshaw, Seth

    2016-02-24

    Müller glia (MG) are the only glial cell type produced by the neuroepithelial progenitor cells that generate the vertebrate retina. MG are required to maintain retinal homeostasis and support the survival of retinal neurons. Furthermore, in certain vertebrate classes, MG function as adult stem cells, mediating retinal regeneration in response to injury. However, the mechanisms that regulate MG development are poorly understood because there is considerable overlap in gene expression between retinal progenitor cells and differentiated MG. We show that the LIM homeodomain transcription factor Lhx2 is required for the development of MG in the mouse retina. Temporally controlled knock-out studies reveal a requirement for Lhx2 during all stages of MG development, ranging from the proliferation of gliocompetent retinal progenitors, activation of Müller-specific gene expression, and terminal differentiation of MG morphological features. We show that Lhx2 regulates gliogenesis in part by regulating directly the expression of Notch pathway genes including Notch1, Dll1, and Dll3 and gliogenic transcription factors such as Hes1, Hes5, Sox8, and Rax. Conditional knock-out of Lhx2 resulted in a rapid downregulation of Notch pathway genes and loss of Notch signaling. We further demonstrate that Müller gliogenesis induced by misexpression of the potently gliogenic Notch pathway transcriptional effector Hes5 requires Lhx2 expression. These results indicate that Lhx2 not only directly regulates expression of Notch signaling pathway components, but also acts together with the gliogenic Notch pathway to drive MG specification and differentiation. PMID:26911688

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

    Science.gov (United States)

    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.

  15. Active form Notch4 promotes the proliferation and differentiation of 3T3-L1 preadipocytes

    Energy Technology Data Exchange (ETDEWEB)

    Lai, Peng-Yeh [Institute of Molecular Biology and Department of Life Science, National Chung Cheng University, Chiayi 621, Taiwan, ROC (China); Tsai, Chong-Bin [Institute of Molecular Biology and Department of Life Science, National Chung Cheng University, Chiayi 621, Taiwan, ROC (China); Department of Ophthalmology, Chiayi Christian Hospital, Chiayi 600, Taiwan, ROC (China); Tseng, Min-Jen, E-mail: biomjt@ccu.edu.tw [Institute of Molecular Biology and Department of Life Science, National Chung Cheng University, Chiayi 621, Taiwan, ROC (China)

    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.

  16. Myeloid-Specific Blockade of Notch Signaling by RBP-J Knockout Attenuates Spinal Cord Injury Accompanied by Compromised Inflammation Response in Mice.

    Science.gov (United States)

    Chen, Bei-Yu; Zheng, Min-Hua; Chen, Yan; Du, Yan-Ling; Sun, Xiao-Long; Zhang, Xing; Duan, Li; Gao, Fang; Liang, Liang; Qin, Hong-Yan; Luo, Zhuo-Jing; Han, Hua

    2015-12-01

    The outcome of spinal cord injury (SCI) is determined by both neural cell-intrinsic survival pathways and tissue microenvironment-derived signals. Macrophages dominating the inflammatory responses in SCI possess both destructive and reparative potentials, according to their activation status. Notch signaling is involved in both cell survival and macrophage-mediated inflammation, but a comprehensive role of Notch signaling in SCI has been elusive. In this study, we compared the effects of general Notch blockade by a pharmaceutical γ-secretase inhibitor (GSI) and myeloid-specific Notch signal disruption by recombination signal binding protein Jκ (RBP-J) knockout on SCI. The administration of Notch signal inhibitor GSI resulted in worsened hind limb locomotion and exacerbated inflammation. However, mice lacking RBP-J, the critical transcription factor mediating signals from all four mammalian Notch receptors, in myeloid lineage displayed promoted functional recovery, attenuated glial scar formation, improved neuronal survival and axon regrowth, and mitigated inflammatory response after SCI. These benefits were accompanied by enhanced AKT activation in the lesion area after SCI. These findings demonstrate that abrogating Notch signal in myeloid cells ameliorates inflammation response post-SCI and promotes functional recovery, but general pharmaceutical Notch interception has opposite effects. Therefore, clinical intervention of Notch signaling in SCI needs to pinpoint myeloid lineage to avoid the counteractive effects of global inhibition.

  17. Roles of Pofut1 and O-fucose in mammalian Notch signaling.

    Science.gov (United States)

    Stahl, Mark; Uemura, Kazuhide; Ge, Changhui; Shi, Shaolin; Tashima, Yuko; Stanley, Pamela

    2008-05-16

    Mammalian Notch receptors contain 29-36 epidermal growth factor (EGF)-like repeats that may be modified by protein O-fucosyltransferase 1 (Pofut1), an essential component of the canonical Notch signaling pathway. The Drosophila orthologue Ofut1 is proposed to function as both a chaperone required for stable cell surface expression of Notch and a protein O-fucosyltransferase. Here we investigate these dual roles of Pofut1 in relation to endogenous Notch receptors of Chinese hamster ovary and murine embryonic stem (ES) cells. We show that fucosylation-deficient Lec13 Chinese hamster ovary cells have wild type levels of Pofut1 and cell surface Notch receptors. Nevertheless, they have reduced binding of Notch ligands and low levels of Delta1- and Jagged1-induced Notch signaling. Exogenous fucose but not galactose rescues both ligand binding and Notch signaling. Murine ES cells lacking Pofut1 also have wild type levels of cell surface Notch receptors. However, Pofut1-/- ES cells do not bind Notch ligands or exhibit Notch signaling. Although overexpression of fucosyltransferase-defective Pofut1 R245A in Pofut1-/- cells partially rescues ligand binding and Notch signaling, this effect is not specific. The same rescue is achieved by an unrelated, inactive, endoplasmic reticulum glucosidase. Therefore, mammalian Notch receptors require Pofut1 for the generation of optimally functional Notch receptors, but, in contrast to Drosophila, Pofut1 is not required for stable cell surface expression of Notch. Importantly, we also show that, under certain circumstances, mammalian Notch receptors are capable of signaling in the absence of Pofut1 and O-fucose.

  18. Single-Cell Gene Expression Analyses Reveal Heterogeneous Responsiveness of Fetal Innate Lymphoid Progenitors to Notch Signaling

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    Sylvestre Chea

    2016-02-01

    Full Text Available T and innate lymphoid cells (ILCs share some aspects of their developmental programs. However, although Notch signaling is strictly required for T cell development, it is dispensable for fetal ILC development. Constitutive activation of Notch signaling, at the common lymphoid progenitor stage, drives T cell development and abrogates ILC development by preventing Id2 expression. By combining single-cell transcriptomics and clonal culture strategies, we characterize two heterogeneous α4β7-expressing lymphoid progenitor compartments. αLP1 (Flt3+ still retains T cell potential and comprises the global ILC progenitor, while αLP2 (Flt3− consists of ILC precursors that are primed toward the different ILC lineages. Only a subset of αLP2 precursors is sensitive to Notch signaling required for their proliferation. Our study identifies, in a refined manner, the diversity of transitional stages of ILC development, their transcriptional signatures, and their differential dependence on Notch signaling.

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

    Science.gov (United States)

    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

  20. Second-generation Notch1 activity-trap mouse line (N1IP::CreHI) provides a more comprehensive map of cells experiencing Notch1 activity.

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    Liu, Zhenyi; Brunskill, Eric; Boyle, Scott; Chen, Shuang; Turkoz, Mustafa; Guo, Yuxuan; Grant, Rachel; Kopan, Raphael

    2015-03-15

    We have previously described the creation and analysis of a Notch1 activity-trap mouse line, Notch1 intramembrane proteolysis-Cre6MT or N1IP::Cre(LO), that marked cells experiencing relatively high levels of Notch1 activation. Here, we report and characterize a second line with improved sensitivity (N1IP::Cre(HI)) to mark cells experiencing lower levels of Notch1 activation. This improvement was achieved by increasing transcript stability and by restoring the native carboxy terminus of Cre, resulting in a five- to tenfold increase in Cre activity. The magnitude of this effect probably impacts Cre activity in strains with carboxy-terminal Ert2 fusion. These two trap lines and the related line N1IP::Cre(ERT2) form a complementary mapping tool kit to identify changes in Notch1 activation patterns in vivo as the consequence of genetic or pharmaceutical intervention, and illustrate the variation in Notch1 signal strength from one tissue to the next and across developmental time. PMID:25725069

  1. Dampening the signals transduced through hedgehog via microRNA miR-7 facilitates notch-induced tumourigenesis.

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    Vanina G Da Ros

    Full Text Available Fine-tuned Notch and Hedgehog signalling pathways via attenuators and dampers have long been recognized as important mechanisms to ensure the proper size and differentiation of many organs and tissues. This notion is further supported by identification of mutations in these pathways in human cancer cells. However, although it is common that the Notch and Hedgehog pathways influence growth and patterning within the same organ through the establishment of organizing regions, the cross-talk between these two pathways and how the distinct organizing activities are integrated during growth is poorly understood. Here, in an unbiased genetic screen in the Drosophila melanogaster eye, we found that tumour-like growth was provoked by cooperation between the microRNA miR-7 and the Notch pathway. Surprisingly, the molecular basis of this cooperation between miR-7 and Notch converged on the silencing of Hedgehog signalling. In mechanistic terms, miR-7 silenced the interference hedgehog (ihog Hedgehog receptor, while Notch repressed expression of the brother of ihog (boi Hedgehog receptor. Tumourigenesis was induced co-operatively following Notch activation and reduced Hedgehog signalling, either via overexpression of the microRNA or through specific down-regulation of ihog, hedgehog, smoothened, or cubitus interruptus or via overexpression of the cubitus interruptus repressor form. Conversely, increasing Hedgehog signalling prevented eye overgrowth induced by the microRNA and Notch pathway. Further, we show that blocking Hh signal transduction in clones of cells mutant for smoothened also enhance the organizing activity and growth by Delta-Notch signalling in the wing primordium. Together, these findings uncover a hitherto unsuspected tumour suppressor role for the Hedgehog signalling and reveal an unanticipated cooperative antagonism between two pathways extensively used in growth control and cancer.

  2. Regulation of Notch signaling during T- and B-cell development by O-fucose glycans.

    Science.gov (United States)

    Stanley, Pamela; Guidos, Cynthia J

    2009-07-01

    Notch signaling is required for the development of all T cells and marginal zone (MZ) B cells. Specific roles in T- and B-cell differentiation have been identified for different Notch receptors, the canonical Delta-like (Dll) and Jagged (Jag) Notch ligands, and downstream effectors of Notch signaling. Notch receptors and ligands are post-translationally modified by the addition of glycans to extracellular domain epidermal growth factor-like (EGF) repeats. The O-fucose glycans of Notch cell-autonomously modulate Notch-ligand interactions and the strength of Notch signaling. These glycans are initiated by protein O-fucosyltransferase 1 (Pofut1), and elongated by the transfer of N-acetylglucosamine (GlcNAc) to the fucose by beta1,3GlcNAc-transferases termed lunatic, manic, or radical fringe. This review discusses T- and B-cell development from progenitors deficient in O-fucose glycans. The combined data show that Lfng and Mfng regulate T-cell development by enhancing the interactions of Notch1 in T-cell progenitors with Dll4 on thymic epithelial cells. In the spleen, Lfng and Mfng cooperate to modify Notch2 in MZ B progenitors, enhancing their interaction with Dll1 on endothelial cells and regulating MZ B-cell production. Removal of O-fucose affects Notch signaling in myelopoiesis and lymphopoiesis, and the O-fucose glycan in the Notch1 ligand-binding domain is required for optimal T-cell development.

  3. Notch3 signaling gates cell cycle entry and limits neural stem cell amplification in the adult pallium

    OpenAIRE

    Alunni, A.; Krecsmarik, M.; A Bosco; Galant, S.; Pan, L.; Moens, C.B.; Bally-Cuif, L.

    2013-01-01

    Maintaining the homeostasis of germinal zones in adult organs is a fundamental but mechanistically poorly understood process. In particular, what controls stem cell activation remains unclear. We have previously shown that Notch signaling limits neural stem cell (NSC) proliferation in the adult zebrafish pallium. Combining pharmacological and genetic manipulations, we demonstrate here that long-term Notch invalidation primarily induces NSC amplification through their activation from quiescenc...

  4. Effect of activated Notch signaling system on Schwann cells%激活的Notch信号系统对许旺细胞调控作用的影响

    Institute of Scientific and Technical Information of China (English)

    王瑾; 邓磊; 王艳华; 张培训; 张宏波; 姜保国

    2010-01-01

    Objective To study the effect of activated Notch signaling system on Schwann cells in vitro. Methods Schwann cells were isolated from sciatic nerves of adult SD rats. Recombinant rat jagged1/FC chimera, an activator of the Notch signaling system, and γ-secretase inhibitor (DAPT), an inhibitor of the Notch signaling system, were added into the culture medium respectively. The cells in the medium added with phosphate buffered saline were used as control group. Then the cultured cells were collected. NICD, as a mark of activated Notch system, was detected by immunofluorescence methods. MTT method was used to calculate the growth curve. The level of NGF in the cell supernatant was assayed by using ELISA. Results Schwann cells in recombinant rat jagged/FC chimera group grew better than those in the control groups. MTT method showed that activated Notch signaling significantly promote the proliferation of the cells(P < 0.05). After cultured for 48 h, the amount of NGF in cell supernatant of recombinant rat jagged1/FC chimera group was significantly increased (P < 0.05). Conclusion When the Notch signaling system is activated, Schwann cells not only proliferate but also secret more NGF.%目的 研究体外激活的Notch信号系统对许旺细胞的调控作用.方法 培养成年SD大鼠坐骨神经许旺细胞,分别加入Notch信号激活剂Recombinant rat jagged1/FC chimera和抑制剂DAPT,空白对照加PBS缓冲液.通过免疫荧光检测细胞Notch信号蛋白激活状态,MTT检测细胞增殖情况,酶联免疫吸附试验检测细胞分泌NGF情况.结果 倒置显微镜下观察Notch激活组细胞生长优于其他各组;MTT检测该组促细胞增殖作用明显(P<0.05),且增殖效果在72 h内逐渐增强;ELISA显示Notch激活组细胞培养上清液中NGF蛋白浓度[(60.11±2.61)pg/ml]较对照组[(51.29±3.59)pg/ml]及抑制组[(43.43±2.82 pg/ml]明显升高(P<0.05).结论 一定剂量的Notch信号激活剂不仅促进体外培养的许旺

  5. A novel anticancer therapy that simultaneously targets aberrant p53 and Notch activities in tumors.

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    Yuting Yao

    Full Text Available Notch signaling pathway plays an important role in tumorigenesis by maintaining the activity of self-renewal of cancer stem cells, and therefore, it is hypothesized that interference of Notch signaling may inhibit tumor formation and progression. H101 is a recombinant oncolytic adenovirus that is cytolytic in cells lacking intact p53, but it is unable to eradicate caner stem cells. In this study, we tested a new strategy of tumor gene therapy by combining a Notch1-siRNA with H101 oncolytic adenovirus. In HeLa-S3 tumor cells, the combined therapy blocked the Notch pathway and induced apoptosis in tumors that are p53-inactive. In nude mice bearing xenograft tumors derived from HeLa-S3 cells, the combination of H101/Notch1-siRNA therapies inhibited tumor growth. Moreover, Notch1-siRNA increased Hexon gene expression at both the transcriptional and the translational levels, and promoted H101 replication in tumors, thereby enhancing the oncolytic activity of H101. These data demonstrate the feasibility to combine H101 p53-targted oncolysis and anti-Notch siRNA activities as a novel anti-cancer therapy.

  6. Downregulation of RND3/RhoE in glioblastoma patients promotes tumorigenesis through augmentation of notch transcriptional complex activity

    International Nuclear Information System (INIS)

    Activation of Notch signaling contributes to glioblastoma multiform (GBM) tumorigenesis. However, the molecular mechanism that promotes the Notch signaling augmentation during GBM genesis remains largely unknown. Identification of new factors that regulate Notch signaling is critical for tumor treatment. The expression levels of RND3 and its clinical implication were analyzed in GBM patients. Identification of RND3 as a novel factor in GBM genesis was demonstrated in vitro by cell experiments and in vivo by a GBM xenograft model. We found that RND3 expression was significantly decreased in human glioblastoma. The levels of RND3 expression were inversely correlated with Notch activity, tumor size, and tumor cell proliferation, and positively correlated with patient survival time. We demonstrated that RND3 functioned as an endogenous repressor of the Notch transcriptional complex. RND3 physically interacted with NICD, CSL, and MAML1, the Notch transcriptional complex factors, promoted NICD ubiquitination, and facilitated the degradation of these cofactor proteins. We further revealed that RND3 facilitated the binding of NICD to FBW7, a ubiquitin ligase, and consequently enhanced NICD protein degradation. Therefore, Notch transcriptional activity was inhibited. Forced expression of RND3 repressed Notch signaling, which led to the inhibition of glioblastoma cell proliferation in vitro and tumor growth in the xenograft mice in vivo. Downregulation of RND3, however, enhanced Notch signaling activity, and subsequently promoted glioma cell proliferation. Inhibition of Notch activity abolished RND3 deficiency-mediated GBM cell proliferation. We conclude that downregulation of RND3 is responsible for the enhancement of Notch activity that promotes glioblastoma genesis

  7. Electroacupuncture pretreatment induces tolerance against focal cerebral ischemia through activation of canonical Notch pathway

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    Zhao Yu

    2012-09-01

    Full Text Available Abstract Background Electroacupuncture (EA pretreatment can induce the tolerance against focal cerebral ischemia. However, the underlying mechanisms have not been fully understood. Emerging evidences suggest that canonical Notch signaling may be involved in ischemic brain injury. In the present study, we tested the hypothesis that EA pretreatment-induced tolerance against focal cerebral ischemia is mediated by Notch signaling. Results EA pretreatment significantly enhanced Notch1, Notch4 and Jag1 gene transcriptions in the striatum, except Notch1 intracellular domain level, which could be increased evidently by ischemia. After ischemia and reperfusion, Hes1 mRNA and Notch1 intracellular domain level in ischemic striatum in EA pretreatment group were increased and reached the peak at 2 h and 24 h, respectively, which were both earlier than the peak achieved in control group. Intraventricular injection with the γ-secretase inhibitor MW167 attenuated the neuroprotective effect of EA pretreatment. Conclusions EA pretreatment induces the tolerance against focal cerebral ischemia through activation of canonical Notch pathway.

  8. Development of the Drosophila entero-endocrine lineage and its specification by the Notch signaling pathway.

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    Takashima, Shigeo; Adams, Katrina L; Ortiz, Paola A; Ying, Chong T; Moridzadeh, Rameen; Younossi-Hartenstein, Amelia; Hartenstein, Volker

    2011-05-15

    In this paper we have investigated the developmental-genetic steps that shape the entero-endocrine system of Drosophila melanogaster from the embryo to the adult. The process starts in the endoderm of the early embryo where precursors of endocrine cells and enterocytes of the larval midgut, as well as progenitors of the adult midgut, are specified by a Notch signaling-dependent mechanism. In a second step that occurs during the late larval period, enterocytes and endocrine cells of a transient pupal midgut are selected from within the clusters of adult midgut progenitors. As in the embryo, activation of the Notch pathway triggers enterocyte differentiation and inhibits cells from further proliferation or choosing the endocrine fate. The third step of entero-endocrine cell development takes place at a mid-pupal stage. Before this time point, the epithelial layer destined to become the adult midgut is devoid of endocrine cells. However, precursors of the intestinal midgut stem cells (pISCs) are already present. After an initial phase of symmetric divisions which causes an increase in their own population size, pISCs start to spin off cells that become postmitotic and express the endocrine fate marker, Prospero. Activation of Notch in pISCs forces these cells into an enterocyte fate. Loss of Notch function causes an increase in the proliferatory activity of pISCs, as well as a higher ratio of Prospero-positive cells. PMID:21382366

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

    Science.gov (United States)

    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

  10. Insensible is a novel nuclear inhibitor of Notch activity in Drosophila.

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    Franck Coumailleau

    Full Text Available Notch signalling regulates a wide range of developmental processes. In the Drosophila peripheral nervous system, Notch regulates a series of binary fate decisions that lead to the formation of regularly spaced sensory organs. Each sensory organ is generated by single sensory organ precursor cell (SOP via a series of asymmetric cell divisions. Starting from a SOP-specific Cis-Regulatory Module (CRM, we identified insensible (insb, a.k.a CG6520, as a SOP/neuron-specific gene encoding a nuclear factor that inhibits Notch signalling activity. First, over-expression of Insb led to the transcriptional repression of a Notch reporter and to phenotypes associated with the inhibition of Notch. Second, while the complete loss of insb activity had no significant phenotype, it enhanced the bristle phenotype associated with reduced levels of Hairless, a nuclear protein acting as a co-repressor for Suppressor of Hairless. In conclusion, our work identified Insb as a novel SOP/neuron-specific nuclear inhibitor of Notch activity in Drosophila.

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

    Science.gov (United States)

    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

  12. UBR-5, a Conserved HECT-Type E3 Ubiquitin Ligase, Negatively Regulates Notch-Type Signaling in Caenorhabditis elegans

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    Safdar, Komal; Gu, Anniya; Xu, Xia; Au, Vinci; Taylor, Jon; Flibotte, Stephane; Moerman, Donald G.; Maine, Eleanor M.

    2016-01-01

    Notch-type signaling mediates cell−cell interactions important for animal development. In humans, reduced or inappropriate Notch signaling activity is associated with various developmental defects and disease states, including cancers. Caenorhabditis elegans expresses two Notch-type receptors, GLP-1 and LIN-12. GLP-1 mediates several cell-signaling events in the embryo and promotes germline proliferation in the developing and adult gonad. LIN-12 acts redundantly with GLP-1 in certain inductive events in the embryo and mediates several cell−cell interactions during larval development. Recovery of genetic suppressors and enhancers of glp-1 or lin-12 loss- or gain-of-function mutations has identified numerous regulators of GLP-1 and LIN-12 signaling activity. Here, we report the molecular identification of sog-1, a gene identified in screens for recessive suppressors of conditional glp-1 loss-of-function mutations. The sog-1 gene encodes UBR-5, the sole C. elegans member of the UBR5/Hyd family of HECT-type E3 ubiquitin ligases. Molecular and genetic analyses indicate that the loss of ubr-5 function suppresses defects caused by reduced signaling via GLP-1 or LIN-12. In contrast, ubr-5 mutations do not suppress embryonic or larval lethality associated with mutations in a downstream transcription factor, LAG-1. In the gonad, ubr-5 acts in the receiving cells (germ cells) to limit GLP-1 signaling activity. SEL-10 is the F-box component of SCFSEL-10 E3 ubiquitin–ligase complex that promotes turnover of Notch intracellular domain. UBR-5 acts redundantly with SEL-10 to limit Notch signaling in certain tissues. We hypothesize that UBR-5 activity limits Notch-type signaling by promoting turnover of receptor or limiting its interaction with pathway components. PMID:27185398

  13. UBR-5, a Conserved HECT-Type E3 Ubiquitin Ligase, Negatively Regulates Notch-Type Signaling in Caenorhabditis elegans

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    Komal Safdar

    2016-07-01

    Full Text Available Notch-type signaling mediates cell−cell interactions important for animal development. In humans, reduced or inappropriate Notch signaling activity is associated with various developmental defects and disease states, including cancers. Caenorhabditis elegans expresses two Notch-type receptors, GLP-1 and LIN-12. GLP-1 mediates several cell-signaling events in the embryo and promotes germline proliferation in the developing and adult gonad. LIN-12 acts redundantly with GLP-1 in certain inductive events in the embryo and mediates several cell−cell interactions during larval development. Recovery of genetic suppressors and enhancers of glp-1 or lin-12 loss- or gain-of-function mutations has identified numerous regulators of GLP-1 and LIN-12 signaling activity. Here, we report the molecular identification of sog-1, a gene identified in screens for recessive suppressors of conditional glp-1 loss-of-function mutations. The sog-1 gene encodes UBR-5, the sole C. elegans member of the UBR5/Hyd family of HECT-type E3 ubiquitin ligases. Molecular and genetic analyses indicate that the loss of ubr-5 function suppresses defects caused by reduced signaling via GLP-1 or LIN-12. In contrast, ubr-5 mutations do not suppress embryonic or larval lethality associated with mutations in a downstream transcription factor, LAG-1. In the gonad, ubr-5 acts in the receiving cells (germ cells to limit GLP-1 signaling activity. SEL-10 is the F-box component of SCFSEL-10 E3 ubiquitin–ligase complex that promotes turnover of Notch intracellular domain. UBR-5 acts redundantly with SEL-10 to limit Notch signaling in certain tissues. We hypothesize that UBR-5 activity limits Notch-type signaling by promoting turnover of receptor or limiting its interaction with pathway components.

  14. Modulation of signal strength switches Notch from an inducer of T cells to an inducer of ILC2

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    Rebecca eGentek

    2013-10-01

    Full Text Available Innate lymphoid cells (ILC are emerging key players of the immune system with close lineage relationship to T cells. ILC2 play an important role in protective immunity against multicellular parasites, but are also involved in the pathogenesis of type 2 immune diseases. Here, we have studied the developmental requirements for human ILC2. We report that ILC2 are present in the thymus of young human donors, possibly reflecting local differentiation. Furthermore, we show that uncommitted lineage-CD34+CD1a- human thymic progenitors have the capacity to develop into ILC2 in vitro under the influence of Notch signaling, either by stimulation with the Notch ligand Delta like 1 (Dll1 or by expression of the active intracellular domain of NOTCH1 (NICD1. The capacity of NICD1 to mobilize the ILC2 differentiation program was sufficiently potent to override commitment to the T cell lineage in CD34+CD1a+ progenitors and force them into the ILC2 lineage. As Notch is an important factor also for T cell development, these results raise the question how one and the same signaling pathway can elicit such distinct developmental outcomes from the same precursors. We provide evidence that Notch signal strength is a critical determinant in this decision: by tuning signal amplitude, Notch can be converted from a T cell inducer (low signal strength to an ILC2 inducer (high signal strength. Thus, this study enhances our understanding of human ILC2 development and identifies a mechanism determining specificity of Notch signal output during T cell and ILC2 differentiation.

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

    Science.gov (United States)

    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

  16. Engineered Biomaterials Control Differentiation and Proliferation of Human-Embryonic-Stem-Cell-Derived Cardiomyocytes via Timed Notch Activation

    Directory of Open Access Journals (Sweden)

    Jason C. Tung

    2014-03-01

    Full Text Available For cell-based treatments of myocardial infarction, a better understanding of key developmental signaling pathways and more robust techniques for producing cardiomyocytes are required. Manipulation of Notch signaling has promise as it plays an important role during cardiovascular development, but previous studies presented conflicting results that Notch activation both positively and negatively regulates cardiogenesis. We developed surface- and microparticle-based Notch-signaling biomaterials that function in a time-specific activation-tunable manner, enabling precise investigation of Notch activation at specific developmental stages. Using our technologies, a biphasic effect of Notch activation on cardiac differentiation was found: early activation in undifferentiated human embryonic stem cells (hESCs promotes ectodermal differentiation, activation in specified cardiovascular progenitor cells increases cardiac differentiation. Signaling also induces cardiomyocyte proliferation, and repeated doses of Notch-signaling microparticles further enhance cardiomyocyte population size. These results highlight the diverse effects of Notch activation during cardiac development and provide approaches for generating large quantities of cardiomyocytes.

  17. Notch signaling and ghost cell fate in the calcifying cystig odontogenic tumor

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    Siar CH

    2011-11-01

    Full Text Available Abstract Notch signaling is an evolutionarily conserved mechanism that enables adjacent cells to adopt different fates. Ghost cells (GCs are anucleate cells with homogeneous pale eosinophilic cytoplasm and very pale to clear central areas (previous nucleus sites. Although GCs are present in a variety of odontogenic lesions notably the calcifying cystic odontogenic tumor (GCOT, their nature and process of formation remains elusive. The aim of this study was to investigate the role of Notch signaling in the cell fate specification of GCs in CCOT. Immunohistochemical staining for four Notch receptors (Notch1, Notch2, Notch3 and Notch4 and three ligands (Jagged1, Jagged2 and Delta1 was performed on archival tissues of five CCOT cases. Level of positivity was quantified as negative (0, mild (+, moderate (2+ and strong (3+. Results revealed that GCs demonstrated overexpression for Notch1 and Jagged1 suggesting that Notch1Jagged1 signaling might serve as the main transduction mechanism in cell fate decision for GCs in CCOT. Protein localizations were largely membranous and/or cytoplasmic. Mineralized GCs also stained positive implicating that the calcification process might be associated with upregulation of these molecules. The other Notch receptors and ligands were weak to absent in GCs and tumoral epithelium. Stromal endothelium and fibroblasts were stained variably positive.

  18. Dissecting and circumventing the requirement for RAM in CSL-dependent Notch signaling.

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    Scott E Johnson

    Full Text Available The Notch signaling pathway is an intercellular communication network vital to metazoan development. Notch activation leads to the nuclear localization of the intracellular portion (NICD of the Notch receptor. Once in the nucleus, NICD binds the transcription factor CSL through a bivalent interaction involving the high-affinity RAM region and the lower affinity ANK domain, converting CSL from a transcriptionally-repressed to an active state. This interaction is believed to directly displace co-repressor proteins from CSL and recruit co-activator proteins. Here we investigate the consequences of this bivalent organization in converting CSL from the repressed to active form. One proposed function of RAM is to promote the weak ANK:CSL interaction; thus, fusion of CSL-ANK should bypass this function of RAM. We find that a CSL-ANK fusion protein is transcriptionally active in reporter assays, but that the addition of RAM in trans further increases transcriptional activity, suggesting another role of RAM in activation. A single F235L point substitution, which disrupts co-repressor binding to CSL, renders the CSL-ANK fusion fully active and refractory to further stimulation by RAM in trans. These results suggest that in the context of a mammalian CSL-ANK fusion protein, the main role of RAM is to displace co-repressor proteins from CSL.

  19. Notch signaling differentially regulates the cell fate of early endocrine precursor cells and their maturing descendants in the mouse pancreas and intestine.

    Science.gov (United States)

    Li, Hui Joyce; Kapoor, Archana; Giel-Moloney, Maryann; Rindi, Guido; Leiter, Andrew B

    2012-11-15

    Notch signaling inhibits differentiation of endocrine cells in the pancreas and intestine. In a number of cases, the observed inhibition occurred with Notch activation in multipotential cells, prior to the initiation of endocrine differentiation. It has not been established how direct activation of Notch in endocrine precursor cells affects their subsequent cell fate. Using conditional activation of Notch in cells expressing Neurogenin3 or NeuroD1, we examined the effects of Notch in both organs, on cell fate of early endocrine precursors and maturing endocrine-restricted cells, respectively. Notch did not preclude the differentiation of a limited number of endocrine cells in either organ when activated in Ngn3(+) precursor cells. In addition, in the pancreas most Ngn3(+) cells adopted a duct but not acinar cell fate; whereas in intestinal Ngn3(+) cells, Notch favored enterocyte and goblet cell fates, while selecting against endocrine and Paneth cell differentiation. A small fraction of NeuroD1(+) cells in the pancreas retain plasticity to respond to Notch, giving rise to intraislet ductules as well as cells with no detectable pancreatic lineage markers that appear to have limited ultrastructural features of both endocrine and duct cells. These results suggest that Notch directly regulates cell fate decisions in multipotential early endocrine precursor cells. Some maturing endocrine-restricted NeuroD1(+) cells in the pancreas switch to the duct lineage in response to Notch, indicating previously unappreciated plasticity at such a late stage of endocrine differentiation.

  20. Inhibition of Notch Signaling Ameliorates Acute Kidney Failure and Downregulates Platelet-Derived Growth Factor Receptor β in the Mouse Model.

    Science.gov (United States)

    Kramer, Jan; Schwanbeck, Ralf; Pagel, Horst; Cakiroglu, Figen; Rohwedel, Jürgen; Just, Ursula

    2016-01-01

    Ischemic acute kidney injury (AKI) is associated with high morbidity and frequent complications. Repeated episodes of AKI may lead to end-stage renal failure. The pathobiology of regeneration in AKI is not well understood and there is no effective clinical therapy that improves regeneration. The Notch signaling pathway plays an essential role in kidney development and has been implicated in tissue repair in the adult kidney. Here, we found that kidneys after experimental AKI in mice showed increased expression of Notch receptors, specifically Notch1-3, of the Notch ligands Jagged-1 (Jag1), Jag2 and Delta-like-4 (Dll4) and of the Notch target genes Hes1, Hey2, HeyL, Sox9 and platelet-derived growth factor receptor β (Pdgfrb). Treatment of ischemic mice with the x03B3;-secretase inhibitor DBZ blocked Notch signaling and specifically downregulated the expression of Notch3 and the Notch target genes Hes1, Hey2, HeyL and Pdgfrb. After DBZ treatment, the mice developed less interstitial edema and displayed altered interstitial inflammation patterns. Furthermore, serum urea and creatinine levels were significantly decreased from 6 h onwards when compared to control mice treated with DMSO only. Our data are consistent with an amelioration of the severity of kidney injury by blocking Notch activation following AKI, and suggest an involvement of Notch-regulated Pdgfrb in AKI pathogenesis. PMID:26939110

  1. Changes in the regulation of the Notch signaling pathway are temporally correlated with regenerative failure in the mouse cochlea

    Directory of Open Access Journals (Sweden)

    Juan Cristobal Maass

    2015-03-01

    Full Text Available Sensorineural hearing loss is most commonly caused by the death of hair cells in the organ of Corti, and once lost, mammalian hair cells do not regenerate. In contrast, other vertebrates such as birds can regenerate hair cells by stimulating division and differentiation of neighboring supporting cells. We currently know little of the genetic networks which become active in supporting cells when hair cells die and that are activated in experimental models of hair cell regeneration.. Several studies have shown that neonatal mammalian cochlear supporting cells are able to trans-differentiate into hair cells when cultured in conditions in which the Notch signaling pathway is blocked. We now show that the ability of cochlear supporting cells to trans-differentiate declines precipitously after birth, such that supporting cells from six-day-old mouse cochlea are entirely unresponsive to a blockade of the Notch pathway. We show that this trend is seen regardless of whether the Notch pathway is blocked with gamma secretase inhibitors, or by antibodies against the Notch1 receptor, suggesting that the action of gamma secretase inhibitors on neonatal supporting cells is likely to be by inhibiting Notch receptor cleavage. The loss of responsiveness to inhibition of the Notch pathway in the first postnatal week is due in part to a down-regulation of Notch receptors and ligands, and we show that this down-regulation persists in the adult animal, even under conditions of noise damage. Our data suggest that the Notch pathway is used to establish the repeating pattern of hair cells and supporting cells in the organ of Corti, but is not required to maintain this cellular mosaic once the production of hair cells and supporting cells is completed. Our results have implications for the proposed used of Notch pathway inhibitors in hearing restoration therapies.

  2. Notch signalling inhibits CD4 expression during initiation and differentiation of human T cell lineage.

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    Stephen M Carlin

    Full Text Available The Delta/Notch signal transduction pathway is central to T cell differentiation from haemopoietic stem cells (HSCs. Although T cell development is well characterized using expression of cell surface markers, the detailed mechanisms driving differentiation have not been established. This issue becomes central with observations that adult HSCs exhibit poor differentiation towards the T cell lineage relative to neonatal or embryonic precursors. This study investigates the contribution of Notch signalling and stromal support cells to differentiation of adult and Cord Blood (CB human HSCs, using the Notch signalling OP9Delta co-culture system. Co-cultured cells were assayed at weekly intervals during development for phenotype markers using flow cytometry. Cells were also assayed for mRNA expression at critical developmental stages. Expression of the central thymocyte marker CD4 was initiated independently of Notch signalling, while cells grown with Notch signalling had reduced expression of CD4 mRNA and protein. Interruption of Notch signalling in partially differentiated cells increased CD4 mRNA and protein expression, and promoted differentiation to CD4(+ CD8(+ T cells. We identified a set of genes related to T cell development that were initiated by Notch signalling, and also a set of genes subsequently altered by Notch signal interruption. These results demonstrate that while Notch signalling is essential for establishment of the T cell lineage, at later stages of differentiation, its removal late in differentiation promotes more efficient DP cell generation. Notch signalling adds to signals provided by stromal cells to allow HSCs to differentiate to T cells via initiation of transcription factors such as HES1, GATA3 and TCF7. We also identify gene expression profile differences that may account for low generation of T cells from adult HSCs.

  3. Notch signaling: targeting cancer stem cells and epithelial-to-mesenchymal transition

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    Espinoza I

    2013-09-01

    Full Text Available Ingrid Espinoza,1,2 Radhika Pochampally,1,2 Fei Xing,1 Kounosuke Watabe,1,3 Lucio Miele1,4 1Cancer Institute, 2Department of Biochemistry, 3Department of Microbiology, 4Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, MS, USA Abstract: Notch signaling is an evolutionarily conserved pathway involved in cell fate control during development, stem cell self-renewal, and postnatal tissue differentiation. Roles for Notch in carcinogenesis, the biology of cancer stem cells, tumor angiogenesis, and epithelial-to-mesenchymal transition (EMT have been reported. This review describes the role of Notch in the “stemness” program in cancer cells and in metastases, together with a brief update on the Notch inhibitors currently under investigation in oncology. These agents may be useful in targeting cancer stem cells and to reverse the EMT process. Keywords: Notch signaling, EMT, cancer stem cells, mesenchymal stem cells, metastases, Notch inhibitors

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

    Science.gov (United States)

    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.

  5. ADAM10-Notch signaling governs the recruitment of ovarian pregranulosa cells and controls folliculogenesis in mice.

    Science.gov (United States)

    Feng, Lizhao; Wang, Yijing; Cai, Han; Sun, Guanghong; Niu, Wanbao; Xin, Qiliang; Tang, Xiaofang; Zhang, Jiawei; Wang, Chao; Zhang, Hua; Xia, Guoliang

    2016-06-01

    Ovarian follicles are the basic functional units of female reproduction in the mammalian ovary. We show here that the protein a disintegrin and metalloproteinase domain 10 (ADAM10), a cell surface sheddase, plays an indispensable role in controlling primordial follicle formation by regulating the recruitment of follicle supporting cells in mice. We demonstrate that suppressing ADAM10 in vitro or deletion of Adam10 in vivo disrupts germline cyst breakdown and primordial follicle formation. Using a cell lineage tracing approach, we show that ADAM10 governs the recruitment of ovarian follicle cells by regulating the differentiation and proliferation of LGR5-positive follicle supporting progenitor cells. By detecting the development of FOXL2-positive pregranulosa cells, we found that inhibiting ADAM10 reduced the number of FOXL2-positive cells in perinatal ovaries. Furthermore, inhibiting ADAM10 suppressed the activation of Notch signaling, and blocking Notch signaling also disrupted the recruitment of follicle progenitor cells. Taken together, these results show that ADAM10-Notch signaling in ovarian somatic cells governs the primordial follicle formation by controlling the development of ovarian pregranulosa cells. The proper recruitment of ovarian follicle supporting cells is essential for establishment of the ovarian reserve in mice. PMID:27084580

  6. Notch activation is dispensable for D, L-sulforaphane-mediated inhibition of human prostate cancer cell migration.

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    Eun-Ryeong Hahm

    Full Text Available D, L-Sulforaphane (SFN, a synthetic racemic analog of broccoli constituent L-sulforaphane, is a highly promising cancer chemopreventive agent with in vivo efficacy against chemically-induced as well as oncogene-driven cancer in preclinical rodent models. Cancer chemopreventive effect of SFN is characterized by G(2/M phase cell cycle arrest, apoptosis induction, and inhibition of cell migration and invasion. Moreover, SFN inhibits multiple oncogenic signaling pathways often hyperactive in human cancers, including nuclear factor-κB, Akt, signal transducer and activator of transcription 3, and androgen receptor. The present study was designed to determine the role of Notch signaling, which is constitutively active in many human cancers, in anticancer effects of SFN using prostate cancer cells as a model. Exposure of human prostate cancer cells (PC-3, LNCaP, and/or LNCaP-C4-2B to SFN as well as its naturally-occurring thio-, sulfinyl-, and sulfonyl-analogs resulted in cleavage (activation of Notch1, Notch2, and Notch4, which was accompanied by a decrease in levels of full-length Notch forms especially at the 16- and 24-hour time points. The SFN-mediated cleavage of Notch isoforms was associated with its transcriptional activation as evidenced by RBP-Jk-, HES-1A/B- and HEY-1 luciferase reporter assays. Migration of PC-3 and LNCaP cells was decreased significantly by RNA interference of Notch1 and Notch2, but not Notch4. Furthermore, SFN-mediated inhibition of PC-3 and LNCaP cell migration was only marginally affected by knockdown of Notch1 and Notch2. Strikingly, SFN administration to Transgenic Adenocarcinoma of Mouse Prostate transgenic mice failed to increase levels of cleaved Notch1, cleaved Notch2, and HES-1 proteins in vivo in prostatic intraepithelial neoplasia, well-differentiated carcinoma or poorly-differentiated prostate cancer lesions. These results indicate that Notch activation is largely dispensable for SFN-mediated inhibition of cell

  7. Silencing NOTCH signaling causes growth arrest in both breast cancer stem cells and breast cancer cells

    Science.gov (United States)

    Suman, S; Das, T P; Damodaran, C

    2013-01-01

    Background: Breast cancer stem cells (BCSCs) are characterized by high aldehyde dehydrogenase (ALDH) enzyme activity and are refractory to current treatment modalities, show a higher risk for metastasis, and influence the epithelial to mesenchymal transition (EMT), leading to a shorter time to recurrence and death. In this study, we focused on examination of the mechanism of action of a small herbal molecule, psoralidin (Pso) that has been shown to effectively suppress the growth of BSCSs and breast cancer cells (BCCs), in breast cancer (BC) models. Methods: ALDH− and ALDH+ BCCs were isolated from MDA-MB-231 cells, and the anticancer effects of Pso were measured using cell viability, apoptosis, colony formation, invasion, migration, mammosphere formation, immunofluorescence, and western blot analysis. Results: Psoralidin significantly downregulated NOTCH1 signaling, and this downregulation resulted in growth inhibition and induction of apoptosis in both ALDH− and ALDH+ cells. Molecularly, Pso inhibited NOTCH1 signaling, which facilitated inhibition of EMT markers (β-catenin and vimentin) and upregulated E-cadherin expression, resulting in reduced migration and invasion of both ALDH− and ALDH+ cells. Conclusion: Together, our results suggest that inhibition of NOTCH1 by Pso resulted in growth arrest and inhibition of EMT in BCSCs and BCCs. Psoralidin appears to be a novel agent that targets both BCSCs and BCCs. PMID:24129237

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

    Science.gov (United States)

    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.

  9. Effects of activating and inhibiting Notch signaling pathway on epidermal stem cell proliferation and differentiation%Notch信号通路激活/抑制对表皮干细胞增殖和分化的影响

    Institute of Scientific and Technical Information of China (English)

    杨荣华; 谢举临; 舒斌; 张利军; 施彦; 祁少海

    2013-01-01

    目的 观察Notch信号通路激活或抑制对表皮干细胞增殖和分化的影响.方法 体外分离培养并纯化大鼠表皮干细胞,分组加入Notch信号激活剂Jagged1/FC蛋白(1000 μg/L)和抑制剂γ-分泌酶抑制剂(DAPT,16 μmol/L),空白对照加磷酸盐缓冲液(PBS),共培养48 h后,通过观察各组细胞形态学变化、克隆计数、噻唑蓝(MTT)法检测吸光度(A)值,比较各组表皮干细胞的增殖能力;通过流式细胞仪及免疫细胞组化法检测细胞表面标记物β1整合素(CD29)及角蛋白CK19、CK10的阳性细胞百分比,比较各组表皮干细胞的分化.结果 3组细胞形态无明显差异.分组培养第5天,Jagged1/FC组贴壁细胞的克隆计数为(45.7±3.8)个,显著高于DAPT组[(16.9±2.1)个]及对照组[(33.4±3.1)个,P<0.05];MTT法检测细胞增殖能力,Jagged1/FC组明显高于对照组,DAPT组明显低于对照组(P<0.05);流式细胞仪检测Jagged1/FC组的β1整合素表达率(96.42±2.57)%显著高于DAPT组[(72.58±3.87)%]及阴性对照组[(8 8.75±3.14)%,P<0.05].免疫组织化学CK19阳性细胞百分比Jagged1/FC组明显高于对照组,DAPT组明显低于对照组(P<0.05);而CK10阳性细胞百分比Jagged1/FC组明显低于对照组,DAPT组明显高于对照组(P<0.05).结论 激活Notch信号通路能促进表皮干细胞增殖并维持低分化状态,而抑制Notch信号通路能促进表皮干细胞向表皮细胞分化.%Objective To observe the effects of activating and inhibiting Notch signaling pathway on epidermal stem cell (ESC) proliferation and differentiation.Methods ESCs of SD rats were isolated,cultured and purified.Recombinant rat Jagged1/FC chimera (1000 μg/L),an activator of the Notch signaling pathway,and DAPT (16 μmol/L),an inhibitor of the Notch signaling system,were added into the culture medium respectively.The cells in the medium added with phosphate buffered saline were used as control group.After co-culture for 48 h

  10. Notch is activated in RANKL-induced osteoclast differentiation and resorption

    NARCIS (Netherlands)

    Duan, Li; de Vos, Paul; Fan, Mingwen; Ren, Yijin

    2008-01-01

    The process of osteoclast differentiation and resorption is fine-tuned by signal pathways, which need to be further elucidated. The aim of this study was to explore the possible connections between NF-kappa B and Notch in RANKL-induced osteoclast activity. To this end, RANKL was used to stimulate mo

  11. Fast and Flexible Tracking and Mitigating a Jamming Signal with an Adaptive Notch Filter

    OpenAIRE

    BORIO DANIELE; O'DRISCOLL CILLIAN; Fortuny Guasch, Joaquim

    2014-01-01

    GNSS jammers are small portable devices able to broadcast disruptive interference and overpower the much weaker GNSS signals. The authors consider the use of an adaptive notch filter as an effective solution for mitigating jamming effects.

  12. Co-regulation of the Notch and Wnt signaling pathways promotes supporting cell proliferation and hair cell regeneration in mouse utricles

    Science.gov (United States)

    Wu, Jingfang; Li, Wenyan; Lin, Chen; Chen, Yan; Cheng, Cheng; Sun, Shan; Tang, Mingliang; Chai, Renjie; Li, Huawei

    2016-01-01

    This work sought to determine the crosstalk between the Notch and Wnt signaling pathways in regulating supporting cell (SC) proliferation and hair cell (HC) regeneration in mouse utricles. We cultured postnatal day (P)3 and P60 mouse utricles, damaged the HCs with gentamicin, and treated the utricles with the γ-secretase inhibitor DAPT to inhibit the Notch pathway and with the Wnt agonist QS11 to active the Wnt pathway. We also used Sox2-CreER, Notch1-flox (exon 1), and Catnb-flox (exon 3) transgenic mice to knock out the Notch pathway and activate the Wnt pathway in Sox2+ SCs. Notch inhibition alone increased SC proliferation and HC number in both undamaged and damaged utricles. Wnt activation alone promoted SC proliferation, but the HC number was not significantly increased. Here we demonstrated the cumulative effects of Notch inhibition and Wnt activation in regulating SC proliferation and HC regeneration. Simultaneously inhibiting Notch and overexpressing Wnt led to significantly greater SC proliferation and greater numbers of HCs than manipulating either pathway alone. Similar results were observed in the transgenic mice. This study suggests that the combination of Notch inhibition and Wnt activation can significantly promote SC proliferation and increase the number of regenerated HCs in mouse utricle. PMID:27435629

  13. Intrahepatic Bile Duct Regeneration in Mice Does Not Require Hnf6 or Notch Signaling through Rbpj

    OpenAIRE

    Walter, Teagan J.; Vanderpool, Charles; Cast, Ashley E.; Huppert, Stacey S.

    2014-01-01

    The potential for intrahepatic bile duct (IHBD) regeneration in patients with bile duct insufficiency diseases is poorly understood. Notch signaling and Hnf6 have each been shown to be important for the morphogenesis of IHBDs in mice. One congenital pediatric liver disease characterized by reduced numbers of IHBDs, Alagille syndrome, is associated with mutations in Notch signaling components. Therefore, we investigated whether liver cell plasticity could contribute to IHBD regeneration in mic...

  14. Mechanism of Notch Pathway Activation and Its Role in the Regulation of Olfactory Plasticity in Drosophila melanogaster.

    Science.gov (United States)

    Kidd, Simon; Lieber, Toby

    2016-01-01

    The neural plasticity of sensory systems is being increasingly recognized as playing a role in learning and memory. We have previously shown that Notch, part of an evolutionarily conserved intercellular signaling pathway, is required in adult Drosophila melanogaster olfactory receptor neurons (ORNs) for the structural and functional plasticity of olfactory glomeruli that is induced by chronic odor exposure. In this paper we address how long-term exposure to odor activates Notch and how Notch in conjunction with chronic odor mediates olfactory plasticity. We show that upon chronic odor exposure a non-canonical Notch pathway mediates an increase in the volume of glomeruli by a mechanism that is autonomous to ORNs. In addition to activating a pathway that is autonomous to ORNs, chronic odor exposure also activates the Notch ligand Delta in second order projection neurons (PNs), but this does not appear to require acetylcholine receptor activation in PNs. Delta on PNs then feeds back to activate canonical Notch signaling in ORNs, which restricts the extent of the odor induced increase in glomerular volume. Surprisingly, even though the pathway that mediates the increase in glomerular volume is autonomous to ORNs, nonproductive transsynaptic Delta/Notch interactions that do not activate the canonical pathway can block the increase in volume. In conjunction with chronic odor, the canonical Notch pathway also enhances cholinergic activation of PNs. We present evidence suggesting that this is due to increased acetylcholine release from ORNs. In regulating physiological plasticity, Notch functions solely by the canonical pathway, suggesting that there is no direct connection between morphological and physiological plasticity. PMID:26986723

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

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    Da-Wei Sun

    2015-11-01

    Full Text Available 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.

  16. Cross Talk between NOTCH Signaling and Biomechanics in Human Aortic Valve Disease Pathogenesis

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    Richard C. Godby

    2014-12-01

    Full Text Available Aortic valve disease is a burgeoning public health problem associated with significant mortality. Loss of function mutations in NOTCH1 cause bicuspid aortic valve (BAV and calcific aortic valve disease. Because calcific nodules manifest on the fibrosa side of the cusp in low fluidic oscillatory shear stress (OSS, elucidating pathogenesis requires approaches that consider both molecular and mechanical factors. Therefore, we examined the relationship between NOTCH loss of function (LOF and biomechanical indices in healthy and diseased human aortic valve interstitial cells (AVICs. An orbital shaker system was used to apply cyclic OSS, which mimics the cardiac cycle and hemodynamics experienced by AVICs in vivo. NOTCH LOF blocked OSS-induced cell alignment in human umbilical vein endothelial cells (HUVECs, whereas AVICs did not align when subjected to OSS under any conditions. In healthy AVICs, OSS resulted in decreased elastin (ELN and α-SMA (ACTA2. NOTCH LOF was associated with similar changes, but in diseased AVICs, NOTCH LOF combined with OSS was associated with increased α-SMA expression. Interestingly, AVICs showed relatively higher expression of NOTCH2 compared to NOTCH1. Biomechanical interactions between endothelial and interstitial cells involve complex NOTCH signaling that contributes to matrix homeostasis in health and disorganization in disease.

  17. Notch signaling regulates late-stage epidermal differentiation and maintains postnatal hair cycle homeostasis.

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    Hsien-Yi Lin

    Full Text Available BACKGROUND: Notch signaling involves ligand-receptor interactions through direct cell-cell contact. Multiple Notch receptors and ligands are expressed in the epidermis and hair follicles during embryonic development and the adult stage. Although Notch signaling plays an important role in regulating differentiation of the epidermis and hair follicles, it remains unclear how Notch signaling participates in late-stage epidermal differentiation and postnatal hair cycle homeostasis. METHODOLOGY AND PRINCIPAL FINDINGS: We applied Cre/loxP system to generate conditional gene targeted mice that allow inactivation of critical components of Notch signaling pathway in the skin. Rbpj, the core component of all four Notch receptors, and Pofut1, an essential factor for ligand-receptor interactions, were inactivated in hair follicle lineages and suprabasal layer of the epidermis using the Tgfb3-Cre mouse line. Rbpj conditional inactivation resulted in granular parakeratosis and reactive epidermal hyperplasia. Pofut1 conditional inactivation led to ultrastructural abnormalities in the granular layer and altered filaggrin processing in the epidermis, suggesting a perturbation of the granular layer differentiation. Disruption of Pofut1 in hair follicle lineages resulted in aberrant telogen morphology, a decrease of bulge stem cell markers, and a concomitant increase of K14-positive keratinocytes in the isthmus of mutant hair follicles. Pofut1-deficent hair follicles displayed a delay in anagen re-entry and dysregulation of proliferation and apoptosis during the hair cycle transition. Moreover, increased DNA double stand breaks were detected in Pofut1-deficent hair follicles, and real time PCR analyses on bulge keratinocytes isolated by FACS revealed an induction of DNA damage response and a paucity of DNA repair machinery in mutant bulge keratinocytes. SIGNIFICANCE: our data reveal a role for Notch signaling in regulating late-stage epidermal differentiation

  18. Genetic deletion of Rnd3 results in aqueductal stenosis leading to hydrocephalus through up-regulation of Notch signaling.

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    Lin, Xi; Liu, Baohui; Yang, Xiangsheng; Yue, Xiaojing; Diao, Lixia; Wang, Jing; Chang, Jiang

    2013-05-14

    Rho family guanosine triphosphatase (GTPase) 3 (Rnd3), a member of the small Rho GTPase family, is involved in the regulation of cell actin cytoskeleton dynamics, cell migration, and proliferation through the Rho kinase-dependent signaling pathway. We report a role of Rnd3 in the pathogenesis of hydrocephalus disorder. Mice with Rnd3 genetic deletion developed severe obstructive hydrocephalus with enlargement of the lateral and third ventricles, but not of the fourth ventricles. The cerebral aqueducts in Rnd3-null mice were partially or completely blocked by the overgrowth of ependymal epithelia. We examined the molecular mechanism contributing to this Rnd3-deficiency-mediated hydrocephalus and found that Rnd3 is a regulator of Notch signaling. Rnd3 deficiency, through either gene deletion or siRNA knockdown, resulted in a decrease in Notch intracellular domain (NICD) protein degradation. However, there was no correlated change in mRNA change, which in turn led to an increase in NICD protein levels. Immunoprecipitation analysis demonstrated that Rnd3 and NICD physically interacted, and that down-regulation of Rnd3 attenuated NICD protein ubiquitination. This eventually enhanced Notch signaling activity and promoted aberrant growth of aqueduct ependymal cells, resulting in aqueduct stenosis and the development of congenital hydrocephalus. Inhibition of Notch activity rescued the hydrocephalus disorder in the mutant animals. PMID:23630292

  19. Role of Notch-1 signaling pathway in PC12 cell apoptosis induced by amyloid beta-peptide (25-35)

    Institute of Scientific and Technical Information of China (English)

    Huimin Liang; Yaozhou Zhang; Xiaoyan Shi; Tianxiang Wei; Jiyu Lou

    2014-01-01

    Recent studies have demonstrated that Notch-1 expression is increased in the hippocampus of Alzheimer’s disease patients. We speculate that Notch-1 signaling may be involved in PC12 cell apoptosis induced by amyloid beta-peptide (25-35) (Aβ25-35). In the present study, PC12 cells were cultured with different doses (0, 0.1, 1.0, 10 and 100 nmol/L) of N-[N-(3,5-Dilfuorophen-acetyl)-L-alanyl]-S-phenylglycine t-butyl ester, a Notch-1 signaling pathway inhibitor, for 30 minutes. Then cultured cells were induced with Aβ25-35 for 48 hours. Pretreatment of PC12 cells with high doses of N-[N-(3,5-Dilfuorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester (> 10 nmol/L) prolonged the survival of PC12 cells after Aβ25-35 induction, decreased the expression of apoptosis-related proteins caspase-3, -8, -9, increased the activity of oxidative stress-related su-peroxide dismutase and catalase, inhibited the production of active oxygen, and reduced nuclear factor kappa B expression. This study indicates that the Notch-1 signaling pathway plays a pivotal role in Aβ25-35-induced PC12 apoptosis.

  20. Embryonic Ethanol Exposure Dysregulates BMP and Notch Signaling, Leading to Persistent Atrio-Ventricular Valve Defects in Zebrafish.

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    Sarmah, Swapnalee; Muralidharan, Pooja; Marrs, James A

    2016-01-01

    Fetal alcohol spectrum disorder (FASD), birth defects associated with ethanol exposure in utero, includes a wide spectrum of congenital heart defects (CHDs), the most prevalent of which are septal and conotruncal defects. Zebrafish FASD model was used to dissect the mechanisms underlying FASD-associated CHDs. Embryonic ethanol exposure (3-24 hours post fertilization) led to defects in atrio-ventricular (AV) valvulogenesis beginning around 37 hpf, a morphogenetic event that arises long after ethanol withdrawal. Valve leaflets of the control embryos comprised two layers of cells confined at the compact atrio-ventricular canal (AVC). Ethanol treated embryos had extended AVC and valve forming cells were found either as rows of cells spanning the AVC or as unorganized clusters near the AV boundary. Ethanol exposure reduced valve precursors at the AVC, but some ventricular cells in ethanol treated embryos exhibited few characteristics of valve precursors. Late staged larvae and juvenile fish exposed to ethanol during embryonic development had faulty AV valves. Examination of AVC morphogenesis regulatory networks revealed that early ethanol exposure disrupted the Bmp signaling gradient in the heart during valve formation. Bmp signaling was prominent at the AVC in controls, but ethanol-exposed embryos displayed active Bmp signaling throughout the ventricle. Ethanol exposure also led to mislocalization of Notch signaling cells in endocardium during AV valve formation. Normally, highly active Notch signaling cells were organized at the AVC. In ethanol-exposed embryos, highly active Notch signaling cells were dispersed throughout the ventricle. At later stages, ethanol-exposed embryos exhibited reduced Wnt/β-catenin activity at the AVC. We conclude that early embryonic ethanol exposure alters Bmp, Notch and other signaling activities during AVC differentiation leading to faulty valve morphogenesis and valve defects persist in juvenile fish. PMID:27556898

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

    Science.gov (United States)

    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.

  2. Efficient differentiation of embryonic stem cells into mesodermal precursors by BMP, retinoic acid and Notch signalling.

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    Josema Torres

    Full Text Available The ability to direct differentiation of mouse embryonic stem (ES cells into specific lineages not only provides new insights into the pathways that regulate lineage selection but also has translational applications, for example in drug discovery. We set out to develop a method of differentiating ES cells into mesodermal cells at high efficiency without first having to induce embryoid body formation. ES cells were plated on a feeder layer of PA6 cells, which have membrane-associated stromal-derived inducing activity (SDIA, the molecular basis of which is currently unknown. Stimulation of ES/PA6 co-cultures with Bone Morphogenetic Protein 4 (BMP4 both favoured self-renewal of ES cells and induced differentiation into a Desmin and Nestin double positive cell population. Combined stimulation with BMP4 and all-trans Retinoic Acid (RA inhibited self-renewal and resulted in 90% of cells expressing Desmin and Nestin. Quantitative reverse transcription-polymerase chain reaction (qPCR analysis confirmed that the cells were of mesodermal origin and expressed markers of mesenchymal and smooth muscle cells. BMP4 activation of a MAD-homolog (Smad-dependent reporter in undifferentiated ES cells was attenuated by co-stimulation with RA and co-culture with PA6 cells. The Notch ligand Jag1 was expressed in PA6 cells and inhibition of Notch signalling blocked the differentiation inducing activity of PA6 cells. Our data suggest that mesodermal differentiation is regulated by the level of Smad activity as a result of inputs from BMP4, RA and the Notch pathway.

  3. Inhibition of Notch signaling affects hepatic oval cell response in rat model of 2AAF-PH

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    Darwiche H

    2011-09-01

    Full Text Available Houda Darwiche, Seh-Hoon Oh, Nicole C Steiger-Luther, Jennifer M Williams, Dana G Pintilie, Thomas D Shupe, Bryon E PetersenDepartment of Pathology, Immunology, and Laboratory Medicine, Program in Stem Cell Biology and Regenerative Medicine, College of Medicine, University of Florida, Gainesville, FL, USABackground and aims: Activation of the oval cell compartment occurs in the liver when hepatocytes are functionally compromised and/or unable to divide. Our goal was to investigate the systemic signals responsible for determining the efficiency of oval cell-mediated liver regeneration, focusing on the Notch signaling cascade.Methods: The established oval cell induction protocol of 2-acetylaminofluorine (2-AAF implantation followed by 70% surgical resection of the liver (partial hepatectomy, PH was employed in a rat model. This oval cell induction model was further combined with injections of a γ-secretase inhibitor (GSI XX to examine the effects of Notch inhibition on oval cell-aided regeneration of the liver.Results: Notch signaling was found to be upregulated at the peak of oval cell induction during 2AAF-PH alone. Treatment with GSI XX led to interruption of the Notch signal, as shown by a decrease in expression of Hes1. While there was a robust oval cell response seen at day 11 post-PH, there was a measurable delay in differentiation when Notch was inhibited. This was confirmed morphologically as well as by immunohistochemistry for the oval cell markers, α-fetoprotein, OV-6, and CK19. The hepatocytes seen at day 22 demonstrated an enhanced hepatocellular mitoinhibition index (p21Waf1/Ki67, suggestive of dysregulated proliferation and cell cycle progression. Moreover, these hepatocytes exhibited decreased expression of hepatocyte functional markers, such as cytochrome P450 and glucose-6-phosphatase-α.Conclusion: Taken together, these results identify the Notch signaling pathway as a potent regulator of differentiation and proliferation in

  4. Role of notch signaling in osteoimmunology-from the standpoint of osteoclast differentiation

    NARCIS (Netherlands)

    Duan, Li; Ren, Yijin

    2013-01-01

    The Notch signaling pathway is a highly conserved cell signaling system present in most multicellular organisms. Osteoimmunology comprises the interplay between the immune system and bone metabolism. Osteoclasts, cells that resorb bone, play a crucial role in bone metabolism. In this review, we disc

  5. Asperosaponin VI promotes progesterone receptor expression in decidual cells via the notch signaling pathway.

    Science.gov (United States)

    Gao, Jie; Zhou, Chun; Li, Yadi; Gao, Feixia; Wu, Haiwang; Yang, Lilin; Qiu, Weiyu; Zhu, Lin; Du, Xin; Lin, Weixian; Huang, Dandan; Liu, Haibin; Liang, Chun; Luo, Songping

    2016-09-01

    Recurrent spontaneous abortion (RSA) is a common clinical condition, but its reasons remain unknown in 37-79% of the affected women. The steroid hormone progesterone (P4) is an integral mediator of early pregnancy events, exerting its effects via the progesterone receptor (PR). Dipsaci Radix (DR) has long been used for treating gynecological diseases in Chinese medicine, while its molecular mechanisms and active ingredients are still unclear. We report here the progesterone-like effects of the alcohol extraction and Asperosaponin VI from DR in primary decidual cells and HeLa cell line. We first determined the safe concentration of Asperosaponin VI in the cells with MTT assay and then found by using dual luciferase reporter and Western blotting that Asperosaponin VI significantly increased PR expression. Moreover, we explored the mechanisms of action of the DR extracts and Asperosaponin VI, and the results showed that they could activate Notch signaling, suggesting that they may function by promoting decidualization. PMID:27370099

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

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    Michelle eWare

    2014-12-01

    Full Text Available 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 behaviour. 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 and the nucleus of the mammillotegmental tract. 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 and act as a scaffold for later, follower axons. This review will cumulate and summarise the existing data available describing initial neurogenesis in the vertebrate hypothalamus. It has only recently been proposed that loss of Notch signalling 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. 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. Scarce studies have shown genes such as Ascl1 and Hes5 are expressed in the hypothalamus earlier than when the first mature neurons appear. The timing of the transcriptional repressors of the Notch signalling pathway and proneural activators will be analysed. We will discuss novel targets that start to unravel the mechanisms behind neurogenesis 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.

  7. An obligatory role of mind bomb-1 in notch signaling of mammalian development.

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    Bon-Kyoung Koo

    Full Text Available BACKGROUND: The Notch signaling pathway is an evolutionarily conserved intercellular signaling module essential for cell fate specification that requires endocytosis of Notch ligands. Structurally distinct E3 ubiquitin ligases, Neuralized (Neur and Mind bomb (Mib, cooperatively regulate the endocytosis of Notch ligands in Drosophila. However, the respective roles of the mammalian E3 ubiquitin ligases, Neur1, Neur2, Mib1, and Mib2, in mammalian development are poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: Through extensive use of mammalian genetics, here we show that Neur1 and Neur2 double mutants and Mib2(-/- mice were viable and grossly normal. In contrast, conditional inactivation of Mib1 in various tissues revealed the representative Notch phenotypes: defects of arterial specification as deltalike4 mutants, abnormal cerebellum and skin development as jagged1 conditional mutants, and syndactylism as jagged2 mutants. CONCLUSIONS/SIGNIFICANCE: Our data provide the first evidence that Mib1 is essential for Jagged as well as Deltalike ligand-mediated Notch signaling in mammalian development, while Neur1, Neur2, and Mib2 are dispensable.

  8. [Inhibitory effect of pumpkin protein on expression of Notch signal in RPMI8226 myeloma cells].

    Science.gov (United States)

    Liu, Ting-Bo; Yang, Pei; Xie, Jie-Ming; Hu, Jian-Da

    2014-08-01

    This study was aimed to explore the inhibitory effect of pumpkin protein (cucurmosin, CUS) on proliferation of RPMI8226 myeloma cells in vitro and its mechanism. Western blot was used to detect the expression level of Notch-1, Jagged-2, P-Akt and NF-KB in the myeloma cells treated by different concentrations of CUS. The results demonstrated that CUS could down-regulate the protein expression levels of Notch1, Jagged-2, P-Akt and NF-KB in the myeloma cells and with time-and concentration-dependent way, at the same time CUS could also decrease the expressions of BCL-2 and P-Akt. It is concluded that CUS can obviously inhibit the RPMI8226 cell proliferation in vitro, down-regulate the expression levels of Notch signal and its down-stream target genes. Therefore, Notch signaling pathway can be used as a new treatment target for multiple myeloma, and CUS may be become a potential new drug for regulating Notch signaling pathway. PMID:25130819

  9. Demonstration of optical steganography transmission using temporal phase coded optical signals with spectral notch filtering.

    Science.gov (United States)

    Hong, Xuezhi; Wang, Dawei; Xu, Lei; He, Sailing

    2010-06-01

    A novel approach is proposed and experimentally demonstrated for optical steganography transmission in WDM networks using temporal phase coded optical signals with spectral notch filtering. A temporal phase coded stealth channel is temporally and spectrally overlaid onto a public WDM channel. Direct detection of the public channel is achieved in the presence of the stealth channel. The interference from the public channel is suppressed by spectral notching before the detection of the optical stealth signal. The approach is shown to have good compatibility and robustness to the existing WDM network for optical steganography transmission.

  10. Electroacupuncture in the repair of spinal cord injury: inhibiting the Notch signaling pathway and promoting neural stem cell proliferation

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    Xin Geng

    2015-01-01

    Full Text Available Electroacupuncture for the treatment of spinal cord injury has a good clinical curative effect, but the underlying mechanism is unclear. In our experiments, the spinal cord of adult Sprague-Dawley rats was clamped for 60 seconds. Dazhui (GV14 and Mingmen (GV4 acupoints of rats were subjected to electroacupuncture. Enzyme-linked immunosorbent assay revealed that the expression of serum inflammatory factors was apparently downregulated in rat models of spinal cord injury after electroacupuncture. Hematoxylin-eosin staining and immunohistochemistry results demonstrated that electroacupuncture contributed to the proliferation of neural stem cells in rat injured spinal cord, and suppressed their differentiation into astrocytes. Real-time quantitative PCR and western blot assays showed that electroacupuncture inhibited activation of the Notch signaling pathway induced by spinal cord injury. These findings indicate that electroacupuncture repaired the injured spinal cord by suppressing the Notch signaling pathway and promoting the proliferation of endogenous neural stem cells.

  11. Electroacupuncture in the repair of spinal cord injury:inhibiting the Notch signaling pathway and promoting neural stem cell proliferation

    Institute of Scientific and Technical Information of China (English)

    Xin Geng; Tao Sun; Jing-hui Li; Ning Zhao; Yong Wang; Hua-lin Yu

    2015-01-01

    Electroacupuncture for the treatment of spinal cord injury has a good clinical curative effect, but the underlying mechanism is unclear. In our experiments, the spinal cord of adult Sprague-Daw-ley rats was clamped for 60 seconds.Dazhui (GV14) andMingmen (GV4) acupoints of rats were subjected to electroacupuncture. Enzyme-linked immunosorbent assay revealed that the expres-sion of serum inlfammatory factors was apparently downregulated in rat models of spinal cord injury after electroacupuncture. Hematoxylin-eosin staining and immunohistochemistry results demonstrated that electroacupuncture contributed to the proliferation of neural stem cells in rat injured spinal cord, and suppressed their differentiation into astrocytes. Real-time quantitative PCR and western blot assays showed that electroacupuncture inhibited activation of the Notch signaling pathway induced by spinal cord injury. These ifndings indicate that electroacupuncture repaired the injured spinal cord by suppressing the Notch signaling pathway and promoting the proliferation of endogenous neural stem cells.

  12. Targeting atypical protein kinase C iota reduces viability in glioblastoma stem-like cells via a notch signaling mechanism.

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    Phillips, Emma; Lang, Verena; Bohlen, Jonathan; Bethke, Frederic; Puccio, Laura; Tichy, Diana; Herold-Mende, Christel; Hielscher, Thomas; Lichter, Peter; Goidts, Violaine

    2016-10-15

    In a previous study, Protein Kinase C iota (PRKCI) emerged as an important candidate gene for glioblastoma (GBM) stem-like cell (GSC) survival. Here, we show that PKCι is overexpressed and activated in patient derived GSCs compared with normal neural stem cells and normal brain lysate, and that silencing of PRKCI in GSCs causes apoptosis, along with loss of clonogenicity and reduced proliferation. Notably, PRKCI silencing reduces tumor growth in vivo in a xenograft mouse model. PKCι has been intensively studied as a therapeutic target in non-small cell lung cancer, resulting in the identification of an inhibitor, aurothiomalate (ATM), which disrupts the PKCι/ERK signaling axis. However, we show that, although sensitive to pharmacological inhibition via a pseudosubstrate peptide inhibitor, GSCs are much less sensitive to ATM, suggesting that PKCι acts along a different signaling axis in GSCs. Gene expression profiling of PRKCI-silenced GSCs revealed a novel role of the Notch signaling pathway in PKCι mediated GSC survival. A proximity ligation assay showed that Notch1 and PKCι are in close proximity in GSCs. Targeting PKCι in the context of Notch signaling could be an effective way of attacking the GSC population in GBM. PMID:27299852

  13. Hypoxia promotes uveal melanoma invasion through enhanced Notch and MAPK activation.

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    Laura Asnaghi

    Full Text Available The transcriptional response promoted by hypoxia-inducible factors has been associated with metastatic spread of uveal melanoma. We found expression of hypoxia-inducible factor 1α (HIF-1α protein in well-vascularized tumor regions as well as in four cell lines grown in normoxia, thus this pathway may be important even in well-oxygenated uveal melanoma cells. HIF-1α protein accumulation in normoxia was inhibited by rapamycin. As expected, hypoxia (1% pO2 further induced HIF-1α protein levels along with its target genes VEGF and LOX. Growth in hypoxia significantly increased cellular invasion of all 5 uveal melanoma lines tested, as did the introduction of an oxygen-insensitive HIF-1α mutant into Mel285 cells with low HIF-1α baseline levels. In contrast, HIF-1α knockdown using shRNA significantly decreased growth in hypoxia, and reduced by more than 50% tumor invasion in four lines with high HIF-1α baseline levels. Pharmacologic blockade of HIF-1α protein expression using digoxin dramatically suppressed cellular invasion both in normoxia and in hypoxia. We found that Notch pathway components, including Jag1-2 ligands, Hes1-Hey1 targets and the intracellular domain of Notch1, were increased in hypoxia, as well as the phosphorylation levels of Erk1-2 and Akt. Pharmacologic and genetic inhibition of Notch largely blocked the hypoxic induction of invasion as did the pharmacologic suppression of Erk1-2 activity. In addition, the increase in Erk1-2 and Akt phosphorylation by hypoxia was partially reduced by inhibiting Notch signaling. Our findings support the functional importance of HIF-1α signaling in promoting the invasive capacity of uveal melanoma cells in both hypoxia and normoxia, and suggest that pharmacologically targeting HIF-1α pathway directly or through blockade of Notch or Erk1-2 pathways can slow tumor spread.

  14. GDE2 regulates subtype-specific motor neuron generation through inhibition of Notch signaling.

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    Sabharwal, Priyanka; Lee, Changhee; Park, Sungjin; Rao, Meenakshi; Sockanathan, Shanthini

    2011-09-22

    The specification of spinal interneuron and motor neuron identities initiates within progenitor cells, while motor neuron subtype diversification is regulated by hierarchical transcriptional programs implemented postmitotically. Here we find that mice lacking GDE2, a six-transmembrane protein that triggers motor neuron generation, exhibit selective losses of distinct motor neuron subtypes, specifically in defined subsets of limb-innervating motor pools that correlate with the loss of force-generating alpha motor neurons. Mechanistically, GDE2 is expressed by postmitotic motor neurons but utilizes extracellular glycerophosphodiester phosphodiesterase activity to induce motor neuron generation by inhibiting Notch signaling in neighboring motor neuron progenitors. Thus, neuronal GDE2 controls motor neuron subtype diversity through a non-cell-autonomous feedback mechanism that directly regulates progenitor cell differentiation, implying that subtype specification initiates within motor neuron progenitor populations prior to their differentiation into postmitotic motor neurons.

  15. Loss of Notch3 Signaling in Vascular Smooth Muscle Cells Promotes Severe Heart Failure Upon Hypertension.

    Science.gov (United States)

    Ragot, Hélène; Monfort, Astrid; Baudet, Mathilde; Azibani, Fériel; Fazal, Loubina; Merval, Régine; Polidano, Evelyne; Cohen-Solal, Alain; Delcayre, Claude; Vodovar, Nicolas; Chatziantoniou, Christos; Samuel, Jane-Lise

    2016-08-01

    Hypertension, which is a risk factor of heart failure, provokes adaptive changes at the vasculature and cardiac levels. Notch3 signaling plays an important role in resistance arteries by controlling the maturation of vascular smooth muscle cells. Notch3 deletion is protective in pulmonary hypertension while deleterious in arterial hypertension. Although this latter phenotype was attributed to renal and cardiac alterations, the underlying mechanisms remained unknown. To investigate the role of Notch3 signaling in the cardiac adaptation to hypertension, we used mice with either constitutive Notch3 or smooth muscle cell-specific conditional RBPJκ knockout. At baseline, both genotypes exhibited a cardiac arteriolar rarefaction associated with oxidative stress. In response to angiotensin II-induced hypertension, the heart of Notch3 knockout and SM-RBPJκ knockout mice did not adapt to pressure overload and developed heart failure, which could lead to an early and fatal acute decompensation of heart failure. This cardiac maladaptation was characterized by an absence of media hypertrophy of the media arteries, the transition of smooth muscle cells toward a synthetic phenotype, and an alteration of angiogenic pathways. A subset of mice exhibited an early fatal acute decompensated heart failure, in which the same alterations were observed, although in a more rapid timeframe. Altogether, these observations indicate that Notch3 plays a major role in coronary adaptation to pressure overload. These data also show that the hypertrophy of coronary arterial media on pressure overload is mandatory to initially maintain a normal cardiac function and is regulated by the Notch3/RBPJκ pathway. PMID:27296994

  16. MicroRNA profiling in subventricular zone after stroke: MiR-124a regulates proliferation of neural progenitor cells through Notch signaling pathway.

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    Xian Shuang Liu

    Full Text Available BACKGROUND: The Notch signaling pathway regulates adult neurogenesis under physiological and pathophysiological conditions. MicroRNAs are small non-coding RNA molecules that regulate gene expression. The present study investigated the effect of miR-124a on the Notch signaling pathway in stroke-induced neurogenesis. METHODOLOGY AND PRINCIPAL FINDINGS: We found that adult rats subjected to focal cerebral ischemia exhibited substantial reduction of miR-124a expression, a neuron specific miRNA, in the neural progenitor cells of the subventricular zone (SVZ of the lateral ventricle, which was inversely associated with activation of Notch signals. In vitro, transfection of neural progenitor cells harvested from the SVZ of adult rat with miR-124a repressed Jagged-1 (JAG1, a ligand of Notch, in a luciferase construct containing the JAG1 target site. Introduction of miR-124a in neural progenitor cells significantly reduced JAG1 transcript and protein levels, leading to inactivation of Notch signals. Transfection of neural progenitor cells with miR-124a significantly reduced progenitor cell proliferation and promoted neuronal differentiation measured by an increase in the number of Doublecortin positive cells, a marker of neuroblasts. Furthermore, introduction of miR-124a significantly increased p27Kip1 mRNA and protein levels, a downstream target gene of the Notch signaling pathway. CONCLUSIONS: Collectively, our study demonstrated that in vivo, stroke alters miRNA expression in SVZ neural progenitor cells and that in vitro, miR-124a mediates stroke-induced neurogenesis by targeting the JAG-Notch signaling pathway.

  17. Specification of Drosophila corpora cardiaca neuroendocrine cells from mesoderm is regulated by Notch signaling.

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    Sangbin Park

    2011-08-01

    Full Text Available Drosophila neuroendocrine cells comprising the corpora cardiaca (CC are essential for systemic glucose regulation and represent functional orthologues of vertebrate pancreatic α-cells. Although Drosophila CC cells have been regarded as developmental orthologues of pituitary gland, the genetic regulation of CC development is poorly understood. From a genetic screen, we identified multiple novel regulators of CC development, including Notch signaling factors. Our studies demonstrate that the disruption of Notch signaling can lead to the expansion of CC cells. Live imaging demonstrates localized emergence of extra precursor cells as the basis of CC expansion in Notch mutants. Contrary to a recent report, we unexpectedly found that CC cells originate from head mesoderm. We show that Tinman expression in head mesoderm is regulated by Notch signaling and that the combination of Daughterless and Tinman is sufficient for ectopic CC specification in mesoderm. Understanding the cellular, genetic, signaling, and transcriptional basis of CC cell specification and expansion should accelerate discovery of molecular mechanisms regulating ontogeny of organs that control metabolism.

  18. Relaxin Prevents Cardiac Fibroblast-Myofibroblast Transition via Notch-1-Mediated Inhibition of TGF-β/Smad3 Signaling

    Science.gov (United States)

    Sassoli, Chiara; Chellini, Flaminia; Pini, Alessandro; Tani, Alessia; Nistri, Silvia; Nosi, Daniele; Zecchi-Orlandini, Sandra; Bani, Daniele; Formigli, Lucia

    2013-01-01

    The hormone relaxin (RLX) is produced by the heart and has beneficial actions on the cardiovascular system. We previously demonstrated that RLX stimulates mouse neonatal cardiomyocyte growth, suggesting its involvement in endogenous mechanisms of myocardial histogenesis and regeneration. In the present study, we extended the experimentation by evaluating the effects of RLX on primary cultures of neonatal cardiac stromal cells. RLX inhibited TGF-β1-induced fibroblast-myofibroblast transition, as judged by its ability to down-regulate α-smooth muscle actin and type I collagen expression. We also found that the hormone up-regulated metalloprotease (MMP)-2 and MMP-9 expression and downregulated the tissue inhibitor of metalloproteinases (TIMP)-2 in TGF-β1-stimulated cells. Interestingly, the effects of RLX on cardiac fibroblasts involved the activation of Notch-1 pathway. Indeed, Notch-1 expression was significantly decreased in TGF-β1-stimulatedfibroblasts as compared to the unstimulated controls; this reduction was prevented by the addition of RLX to TGF-β1-stimulated cells. Moreover, pharmacological inhibition of endogenous Notch-1 signaling by N-3,5-difluorophenyl acetyl-L-alanyl-2-phenylglycine-1,1-dimethylethyl ester (DAPT), a γ-secretase specific inhibitor, as well as the silencing of Notch-1 ligand, Jagged-1, potentiated TGF-β1-induced myofibroblast differentiation and abrogated the inhibitory effects of RLX. Interestingly, RLX and Notch-1 exerted their inhibitory effects by interfering with TGF-β1 signaling, since the addition of RLX to TGF-β1-stimulated cells caused a significant decrease in Smad3 phosphorylation, a typical downstream event of TGF-β1 receptor activation, while the treatment with a prevented this effect. These data suggest that Notch signaling can down-regulate TGF-β1/Smad3-induced fibroblast-myofibroblast transition and that RLX could exert its well known anti-fibrotic action through the up-regulation of this pathway. In conclusion

  19. Relaxin prevents cardiac fibroblast-myofibroblast transition via notch-1-mediated inhibition of TGF-β/Smad3 signaling.

    Directory of Open Access Journals (Sweden)

    Chiara Sassoli

    Full Text Available The hormone relaxin (RLX is produced by the heart and has beneficial actions on the cardiovascular system. We previously demonstrated that RLX stimulates mouse neonatal cardiomyocyte growth, suggesting its involvement in endogenous mechanisms of myocardial histogenesis and regeneration. In the present study, we extended the experimentation by evaluating the effects of RLX on primary cultures of neonatal cardiac stromal cells. RLX inhibited TGF-β1-induced fibroblast-myofibroblast transition, as judged by its ability to down-regulate α-smooth muscle actin and type I collagen expression. We also found that the hormone up-regulated metalloprotease (MMP-2 and MMP-9 expression and downregulated the tissue inhibitor of metalloproteinases (TIMP-2 in TGF-β1-stimulated cells. Interestingly, the effects of RLX on cardiac fibroblasts involved the activation of Notch-1 pathway. Indeed, Notch-1 expression was significantly decreased in TGF-β1-stimulatedfibroblasts as compared to the unstimulated controls; this reduction was prevented by the addition of RLX to TGF-β1-stimulated cells. Moreover, pharmacological inhibition of endogenous Notch-1 signaling by N-3,5-difluorophenyl acetyl-L-alanyl-2-phenylglycine-1,1-dimethylethyl ester (DAPT, a γ-secretase specific inhibitor, as well as the silencing of Notch-1 ligand, Jagged-1, potentiated TGF-β1-induced myofibroblast differentiation and abrogated the inhibitory effects of RLX. Interestingly, RLX and Notch-1 exerted their inhibitory effects by interfering with TGF-β1 signaling, since the addition of RLX to TGF-β1-stimulated cells caused a significant decrease in Smad3 phosphorylation, a typical downstream event of TGF-β1 receptor activation, while the treatment with a prevented this effect. These data suggest that Notch signaling can down-regulate TGF-β1/Smad3-induced fibroblast-myofibroblast transition and that RLX could exert its well known anti-fibrotic action through the up-regulation of this

  20. The effects of notch filtering on electrically evoked myoelectric signals and associated motor unit index estimates

    Directory of Open Access Journals (Sweden)

    Li Xiaoyan

    2011-11-01

    Full Text Available Abstract Background Notch filtering is the most commonly used technique for suppression of power line and harmonic interference that often contaminate surface electromyogram (EMG signals. Notch filters are routinely included in EMG recording instrumentation, and are used very often during clinical recording sessions. The objective of this study was to quantitatively assess the effects of notch filtering on electrically evoked myoelectric signals and on the related motor unit index measurements. Methods The study was primarily based on an experimental comparison of M wave recordings and index estimates of motor unit number and size, with the notch filter function of the EMG machine (Sierra Wave EMG system, Cadwell Lab Inc, Kennewick, WA, USA turned on and off, respectively. The comparison was implemented in the first dorsal interosseous (FDI muscle from the dominant hand of 15 neurologically intact subjects and bilaterally in 15 hemiparetic stroke subjects. Results On average, for intact subjects, the maximum M wave amplitude and the motor unit number index (MUNIX estimate were reduced by approximately 22% and 18%, respectively, with application of the built-in notch filter function in the EMG machine. This trend held true when examining the paretic and contralateral muscles of the stroke subjects. With the notch filter on vs. off, across stroke subjects, we observed a significant decrease in both maximum M wave amplitude and MUNIX values in the paretic muscles, as compared with the contralateral muscles. However, similar reduction ratios were obtained for both maximum M wave amplitude and MUNIX estimate. Across muscles of both intact and stroke subjects, it was observed that notch filtering does not have significant effects on motor unit size index (MUSIX estimate. No significant difference was found in MUSIX values between the paretic and contralateral muscles of the stroke subjects. Conclusions The notch filter function built in the EMG

  1. Targeting Tumor Initiating Cells through Inhibition of Cancer Testis Antigens and Notch Signaling: A Hypothesis.

    Science.gov (United States)

    Colombo, Michela; Mirandola, Leonardo; Reidy, Adair; Suvorava, Natallia; Konala, Venu; Chiaramonte, Raffaella; Grizzi, Fabio; Rahman, Rakhshanda Layeequr; Jenkins, Marjorie R; Nugyen, Diane D; Dalhbeck, Scott; Cobos, Everardo; Figueroa, Jose A; Chiriva-Internati, Maurizio

    2015-03-01

    Tumor initiating cells (TICs) differ from normal stem cells (SCs) in their ability to initiate tumorigenesis, invasive growth, metastasis and the acquisition of chemo and/or radio-resistance. Over the past years, several studies have indicated the potential role of the Notch system as a key regulator of cellular stemness and tumor development. Furthermore, the expression of cancer testis antigens (CTA) in TICs, and their role in SC differentiation and biology, has become an important area of investigation. Here, we propose a model in which CTA expression and Notch signaling interacts to maintain the sustainability of self-replicating tumor populations, ultimately leading to the development of metastasis, drug resistance and cancer progression. We hypothesize that Notch-CTA interactions in TICs offer a novel opportunity for meaningful therapeutic interventions in cancer. PMID:25901861

  2. Regulation of monocyte cell fate by blood vessels mediated by Notch signalling.

    Science.gov (United States)

    Gamrekelashvili, Jaba; Giagnorio, Roberto; Jussofie, Jasmin; Soehnlein, Oliver; Duchene, Johan; Briseño, Carlos G; Ramasamy, Saravana K; Krishnasamy, Kashyap; Limbourg, Anne; Kapanadze, Tamar; Ishifune, Chieko; Hinkel, Rabea; Radtke, Freddy; Strobl, Lothar J; Zimber-Strobl, Ursula; Napp, L Christian; Bauersachs, Johann; Haller, Hermann; Yasutomo, Koji; Kupatt, Christian; Murphy, Kenneth M; Adams, Ralf H; Weber, Christian; Limbourg, Florian P

    2016-08-31

    A population of monocytes, known as Ly6C(lo) monocytes, patrol blood vessels by crawling along the vascular endothelium. Here we show that endothelial cells control their origin through Notch signalling. Using combinations of conditional genetic deletion strategies and cell-fate tracking experiments we show that Notch2 regulates conversion of Ly6C(hi) monocytes into Ly6C(lo) monocytes in vivo and in vitro, thereby regulating monocyte cell fate under steady-state conditions. This process is controlled by Notch ligand delta-like 1 (Dll1) expressed by a population of endothelial cells that constitute distinct vascular niches in the bone marrow and spleen in vivo, while culture on recombinant DLL1 induces monocyte conversion in vitro. Thus, blood vessels regulate monocyte conversion, a form of committed myeloid cell fate regulation.

  3. The clerodane diterpene casearin J induces apoptosis of T-ALL cells through SERCA inhibition, oxidative stress, and interference with Notch1 signaling.

    Science.gov (United States)

    De Ford, C; Heidersdorf, B; Haun, F; Murillo, R; Friedrich, T; Borner, C; Merfort, I

    2016-01-28

    T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematologic malignancy that preferentially affects children and adolescents. Over 50% of human T-ALLs possess activating mutations of Notch1. The clerodane diterpene casearin J (CJ) is a natural product that inhibits the sarcoendoplasmatic reticulum calcium ATPase (SERCA) pump and induces cell death in leukemia cells, but the molecular mechanism of cytotoxicity remains poorly understood. Here we show that owing to SERCA pump inhibition, CJ induces depletion of the endoplasmic reticulum calcium pools, oxidative stress, and apoptosis via the intrinsic signaling pathway. Moreover, Notch1 signaling is reduced in T-ALL cells with auto-activating mutations in the HD-domain of Notch1, but not in cells that do not depend on Notch1 signaling. CJ also provoked a slight activation of NF-κB, and consistent with this notion a combined treatment of CJ and the NF-κB inhibitor parthenolide (Pt) led to a remarkable synergistic cell death in T-ALL cells. Altogether, our data support the concept that inhibition of the SERCA pump may be a novel strategy for the treatment of T-ALL with HD-domain-mutant Notch1 receptors and that additional treatment with the NF-κB inhibitor parthenolide may have further therapeutic benefits.

  4. Activated Notch Causes Deafness by Promoting a Supporting Cell Phenotype in Developing Auditory Hair Cells

    OpenAIRE

    Grace Savoy-Burke; Felicia A Gilels; Wei Pan; Diana Pratt; Jianwen Que; Lin Gan; White, Patricia M.; Kiernan, Amy E.

    2014-01-01

    Purpose To determine whether activated Notch can promote a supporting cell fate during sensory cell differentiation in the inner ear. Methods An activated form of the Notch1 receptor (NICD) was expressed in early differentiating hair cells using a Gfi1-Cre mouse allele. To determine the effects of activated Notch on developing hair cells, Gfi1-NICD animals and their littermate controls were assessed at 5 weeks for hearing by measuring auditory brainstem responses (ABRs) and distortion product...

  5. Crucial role of Notch signaling in osteogenic differentiation of periodontal ligament stem cells in osteoporotic rats.

    Science.gov (United States)

    Li, Ying; Li, S Q; Gao, Y M; Li, Jin; Zhang, Bin

    2014-06-01

    Estrogen deficiency-induced osteoporosis typically occurs in postmenopausal women and has been strongly associated with periodontal diseases. Periodontal ligament stem cells (PDLSCs) isolated from the periodontal ligament can differentiate into many types of specialized cells, including osteoblast-like cells that contribute to periodontal tissue repair. The Notch signaling pathway is highly conserved and associated with self-renewal potential and cell-fate determination. Recently, several studies have focused on the relationship between Notch signaling and osteogenic differentiation. However, the precise mechanisms underlying this relationship are largely unknown. We have successfully isolated PDLSCs from both ovariectomized (OVX) and sham-operated rats. Both the mRNA and protein levels of Notch1 and Jagged1 were upregulated when PDLSCs were cultured in osteogenic induction media. Mineralization assays showed decreased calcium deposits in OVX-PDLSCs treated with a γ-secretase inhibitor compared with control cells. Thus Notch signaling is important in maintaining the osteogenic differentiation of PDLSCs in osteoporotic rats, which help in the development of a potential therapeutic strategy for periodontal disease in postmenopausal women.

  6. PLCε knockdown inhibits prostate cancer cell proliferation via suppression of Notch signalling and nuclear translocation of the androgen receptor.

    Science.gov (United States)

    Wang, Yin; Wu, Xiaohou; Ou, Liping; Yang, Xue; Wang, Xiaorong; Tang, Min; Chen, E; Luo, Chunli

    2015-06-28

    Phospholipase Cε (PLCε), a key regulator of diverse cellular functions, has been implicated in various malignancies. Indeed, PLCε functions include cell proliferation, apoptosis and malignant transformation. Here, we show that PLCε expression is elevated in prostate cancer (PCa) tissues compared to benign prostate tissues. Furthermore, PLCε depletion using an adenovirally delivered shRNA significantly decreased cell growth and colony formation, arresting the PC3 and LNCaP cell lines in the S phase of the cell cycle. We also observed that PLCε was significantly correlated with Notch1 and androgen receptor (AR). Additionally, we demonstrate that the activation of both the Notch and AR signalling pathways is involved in PLCε-mediated oncogenic effects in PCa. Our findings suggest that PLCε is a putative oncogene and prognostic marker, potentially representing a novel therapeutic target for PCa.

  7. The bHLH factors Dpn and members of the E(spl complex mediate the function of Notch signalling regulating cell proliferation during wing disc development

    Directory of Open Access Journals (Sweden)

    Beatriz P. San Juan

    2012-05-01

    The Notch signalling pathway plays an essential role in the intricate control of cell proliferation and pattern formation in many organs during animal development. In addition, mutations in most members of this pathway are well characterized and frequently lead to tumour formation. The Drosophila imaginal wing discs have provided a suitable model system for the genetic and molecular analysis of the different pathway functions. During disc development, Notch signalling at the presumptive wing margin is necessary for the restricted activation of genes required for pattern formation control and disc proliferation. Interestingly, in different cellular contexts within the wing disc, Notch can either promote cell proliferation or can block the G1-S transition by negatively regulating the expression of dmyc and bantam micro RNA. The target genes of Notch signalling that are required for these functions have not been identified. Here, we show that the Hes vertebrate homolog, deadpan (dpn, and the Enhancer-of-split complex (E(splC genes act redundantly and cooperatively to mediate the Notch signalling function regulating cell proliferation during wing disc development.

  8. Tumor-derived Jagged1 Promotes Osteolytic Bone Metastasis of Breast Cancer by Engaging Notch Signaling in Bone Cells

    OpenAIRE

    Sethi, Nilay; Dai, Xudong; Winter, Christopher G.; Kang, Yibin

    2011-01-01

    Despite evidence supporting an oncogenic role in breast cancer, the Notch pathway’s contribution to metastasis remains unknown. Here we report that the Notch ligand Jagged1 is a clinically and functionally important mediator of bone metastasis by activating the Notch pathway in bone cells. Jagged1 promotes tumor growth by stimulating IL-6 release from osteoblasts and directly activates osteoclast differentiation. Furthermore, Jagged1 is a potent downstream mediator of the bone metastasis cyto...

  9. Epidermal growth factor promotes proliferation of dermal papilla cells via Notch signaling pathway.

    Science.gov (United States)

    Zhang, Haihua; Nan, Weixiao; Wang, Shiyong; Zhang, Tietao; Si, Huazhe; Wang, Datao; Yang, Fuhe; Li, Guangyu

    2016-08-01

    The effect of epidermal growth factor (EGF) on the development and growth of hair follicle is controversial. In the present study, 2-20 ng/ml EGF promoted the growth of mink hair follicles in vitro, whereas 200 ng/ml EGF inhibited follicle growth. Further, dermal papilla (DP) cells, a group of mesenchymal cells that govern hair follicle development and growth, were isolated and cultured in vitro. Treatment with or forced expression of EGF accelerated proliferation and induced G1/S transition in DP cells. Moreover, EGF upregulated the expression of DP mesenchymal genes, such as alkaline phosphatase (ALP) and insulin-like growth factor (IGF-1), as well as the Notch pathway molecules including Notch1, Jagged1, Hes1 and Hes5. In addition, inhibition of Notch signaling pathway by DAPT significantly reduced the basal and EGF-enhanced proliferation rate, and also suppressed cell cycle progression. We also show that the expression of several follicle-regulatory genes, such as Survivin and Msx2, were upregulated by EGF, and was inhibited by DAPT. In summary, our study demonstrates that the concentration of EGF is critical for the switch between hair follicle growth and inhibition, and EGF promotes DP cell proliferation via Notch signaling pathway.

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

    Science.gov (United States)

    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.

  11. Postembryonic neuronal addition in Zebrafish dorsal root ganglia is regulated by Notch signaling

    Directory of Open Access Journals (Sweden)

    McGraw Hillary

    2012-06-01

    Full Text Available Abstract Background The sensory neurons and glia of the dorsal root ganglia (DRG arise from neural crest cells in the developing vertebrate embryo. In mouse and chick, DRG formation is completed during embryogenesis. In contrast, zebrafish continue to add neurons and glia to the DRG into adulthood, long after neural crest migration is complete. The molecular and cellular regulation of late DRG growth in the zebrafish remains to be characterized. Results In the present study, we use transgenic zebrafish lines to examine neuronal addition during postembryonic DRG growth. Neuronal addition is continuous over the period of larval development. Fate-mapping experiments support the hypothesis that new neurons are added from a population of resident, neural crest-derived progenitor cells. Conditional inhibition of Notch signaling was used to assess the role of this signaling pathway in neuronal addition. An increase in the number of DRG neurons is seen when Notch signaling is inhibited during both early and late larval development. Conclusions Postembryonic growth of the zebrafish DRG comes about, in part, by addition of new neurons from a resident progenitor population, a process regulated by Notch signaling.

  12. Notch Signaling Contributes to Liver Inflammation by Regulation of Interleukin-22-Producing Cells in Hepatitis B Virus Infection

    Science.gov (United States)

    Wei, Xin; Wang, Jiu-Ping; Hao, Chun-Qiu; Yang, Xiao-Fei; Wang, Lin-Xu; Huang, Chang-Xing; Bai, Xue-Fan; Lian, Jian-Qi; Zhang, Ye

    2016-01-01

    The mechanism of hepatitis B virus (HBV) induced liver inflammation is not fully elucidated. Notch signaling augmented interleukin (IL)-22 secretion in CD4+ T cells, and Notch-IL-22 axis fine-tuned inflammatory response. We previously demonstrated a proinflammatory role of IL-22 in HBV infection. Thus, in this study, we analyzed the role of Notch in development of IL-22-producing cells in HBV infection by inhibition of Notch signaling using γ-secretase inhibitor DAPT in both hydrodynamic induced HBV-infected mouse model and in peripheral blood cells isolated from patients with HBV infection. mRNA expressions of Notch1 and Notch2 were significantly increased in livers and CD4+ T cells upon HBV infection. Inhibition of Notch signaling in vivo leaded to the reduction in NKp46+ innate lymphoid cells 22 (ILC22) and lymphoid tissue inducer 4 (LTi4) cells in the liver. This process was accompanied by downregulating the expressions of IL-22 and related proinflammatory cytokines and chemokines in the liver, as well as blocking the recruitment of antigen-non-specific inflammatory cells into the liver and subsequent liver injury, but did not affect HBV antigens production and IL-22 secretion in the serum. Furthermore, IL-22 production in HBV non-specific cultured CD4+ T cells, but not HBV-specific CD4+ T cells, was reduced in response to in vitro inhibition of Notch signaling. In conclusion, Notch siganling appears to be an important mediator of the liver inflammation by modulating hepatic ILC22. The potential proinflammatory effect of Notch-mediated ILC22 may be significant for the development of new therapeutic approaches for treatment of hepatitis B.

  13. Development of the Drosophila entero-endocrine lineage and its specification by the Notch signaling pathway

    OpenAIRE

    Takashima, Shigeo; Adams, Katrina L; Paola A Ortiz; Ying, Chong T.; Moridzadeh, Rameen; Younossi-Hartenstein, Amelia; Hartenstein, Volker

    2011-01-01

    In this paper we have investigated the developmental-genetic steps that shape the entero-endocrine system of Drosophila melanogaster from the embryo to the adult. The process starts in the endoderm of the early embryo where precursors of endocrine cells and enterocytes of the larval midgut, as well as progenitors of the adult midgut, are specified by a Notch signaling-dependent mechanism. In a second step that occurs during the late larval period, enterocytes and endocrine cells of a transien...

  14. Homemade notch filter to suppress strong FM or DAB - T/DVB - T signals

    Science.gov (United States)

    Monstein, Christian

    2016-04-01

    Many of the current 116 solar radio spectrometer instruments in the e-Callisto network are suffering from strong interference from FM-radio, DAB-T or DVB-T broadcast stations. With simple surface mount device (SMD) components a cheap notch (trap)filter can be produced to suppress these strong signals that otherwise may saturate the low noise amplifier and/or the receiver.

  15. The endoderm specifies the mesodermal niche for the germline in Drosophila via Delta-Notch signaling

    OpenAIRE

    Okegbe, Tishina C.; DiNardo, Stephen

    2011-01-01

    Interactions between niche cells and stem cells are vital for proper control over stem cell self-renewal and differentiation. However, there are few tissues where the initial establishment of a niche has been studied. The Drosophila testis houses two stem cell populations, which each lie adjacent to somatic niche cells. Although these niche cells sustain spermatogenesis throughout life, it is not understood how their fate is established. Here, we show that Notch signaling is necessary to spec...

  16. Notch signaling, the segmentation clock, and the patterning of vertebrate somites

    Directory of Open Access Journals (Sweden)

    Lewis Julian

    2009-05-01

    Full Text Available Abstract The Notch signaling pathway has multifarious functions in the organization of the developing vertebrate embryo. One of its most fundamental roles is in the emergence of the regular pattern of somites that will give rise to the musculoskeletal structures of the trunk. The parts it plays in the early operation of the segmentation clock and the later definition and differentiation of the somites are beginning to be understood.

  17. Notch signal reception is required in vascular smooth muscle cells for ductus arteriosus closure.

    Science.gov (United States)

    Krebs, Luke T; Norton, Christine R; Gridley, Thomas

    2016-02-01

    The ductus arteriosus is an arterial vessel that shunts blood flow away from the lungs during fetal life, but normally occludes after birth to establish the adult circulation pattern. Failure of the ductus arteriosus to close after birth is termed patent ductus arteriosus, and is one of the most common congenital heart defects. Our previous work demonstrated that vascular smooth muscle cell expression of the Jag1 gene, which encodes a ligand for Notch family receptors, is essential for postnatal closure of the ductus arteriosus in mice. However, it was not known what cell population was responsible for receiving the Jag1-mediated signal. Here we show, using smooth muscle cell-specific deletion of the Rbpj gene, which encodes a transcription factor that mediates all canonical Notch signaling, that Notch signal reception in the vascular smooth muscle cell compartment is required for ductus arteriosus closure. These data indicate that homotypic vascular smooth muscle cell interactions are required for proper contractile smooth muscle cell differentiation and postnatal closure of the ductus arteriosus in mice.

  18. Control of Neural Daughter Cell Proliferation by Multi-level Notch/Su(H)/E(spl)-HLH Signaling.

    Science.gov (United States)

    Bivik, Caroline; MacDonald, Ryan B; Gunnar, Erika; Mazouni, Khalil; Schweisguth, Francois; Thor, Stefan

    2016-04-01

    The Notch pathway controls proliferation during development and in adulthood, and is frequently affected in many disorders. However, the genetic sensitivity and multi-layered transcriptional properties of the Notch pathway has made its molecular decoding challenging. Here, we address the complexity of Notch signaling with respect to proliferation, using the developing Drosophila CNS as model. We find that a Notch/Su(H)/E(spl)-HLH cascade specifically controls daughter, but not progenitor proliferation. Additionally, we find that different E(spl)-HLH genes are required in different neuroblast lineages. The Notch/Su(H)/E(spl)-HLH cascade alters daughter proliferation by regulating four key cell cycle factors: Cyclin E, String/Cdc25, E2f and Dacapo (mammalian p21CIP1/p27KIP1/p57Kip2). ChIP and DamID analysis of Su(H) and E(spl)-HLH indicates direct transcriptional regulation of the cell cycle genes, and of the Notch pathway itself. These results point to a multi-level signaling model and may help shed light on the dichotomous proliferative role of Notch signaling in many other systems. PMID:27070787

  19. Epigallocatechin gallate inhibits the proliferation of colorectal cancer cells by regulating Notch signaling

    Directory of Open Access Journals (Sweden)

    Jin H

    2013-03-01

    Full Text Available Heiying Jin,1,* Wei Gong,2,* Chunxia Zhang,1,* Shuiming Wang1 1National Center of Colorectal Surgery, the Third Affiliated Hospital of Nanjing University of Traditional Chinese Medicine, Nanjing, People’s Republic of China; 2Department of Surgery, Jiangyin Hospital of Traditional Chinese Medicine, Jiangsu, People's Republic of China*These authors contributed equally to this workAims: To explore the inhibitory effects of epigallocatechin gallate (EGCG on the proliferation of colorectal cancer cells and on the gene expression of Notch signaling.Methods: The colorectal cancer cells and orthotopic colorectal cancer transplant model were treated with EGCG, and MTT assay was used to test the inhibitory role of EGCG in the proliferation of colorectal cancer cells. Results: MTT assay indicated that EGCG inhibited the proliferation of these four cell lines when the time and concentration increased, and EGCG enhanced the apoptotic rate of these four cell lines. The dosage was positively correlated to the apoptotic rate, and EGCG inhibited the proliferation of colorectal cancer cells by influencing cell cycle. In-vivo study suggested that on the seventh day, the volume of tumors reduced after administrating with 5, 10 and 20 mg/kg of EGCG. At the twenty-eighth day, the volume of tumors was significantly different in three EGCG treatment groups as compared to the control group (P < 0.05, and TUNEL assay indicated that the apoptosis of cancer cells in EGCG treated groups was markedly higher than that in the control group (P < 0.05. In these cell lines, the expressions of HES1 and Notch2 in EGCG treated groups were remarkably lower than that in the control group (P < 0.05. The expression of JAG1 decreased in SW480 cells (P = 0.019, HT-29 cells and HCT-8 cells, but increased in LoVo cells at mRNA level. The expression of Notch1 was upregulated in these four cell lines, but its expression was significantly upregulated only in LoVo and SW480 cells (P < 0

  20. Notch1-Dll4 signalling and mechanical force regulate leader cell formation during collective cell migration.

    Science.gov (United States)

    Riahi, Reza; Sun, Jian; Wang, Shue; Long, Min; Zhang, Donna D; Wong, Pak Kin

    2015-03-13

    At the onset of collective cell migration, a subset of cells within an initially homogenous population acquires a distinct 'leader' phenotype with characteristic morphology and motility. However, the factors driving the leader cell formation as well as the mechanisms regulating leader cell density during the migration process remain to be determined. Here we use single-cell gene expression analysis and computational modelling to show that the leader cell identity is dynamically regulated by Dll4 signalling through both Notch1 and cellular stress in a migrating epithelium. Time-lapse microscopy reveals that Dll4 is induced in leader cells after the creation of the cell-free region and leader cells are regulated via Notch1-Dll4 lateral inhibition. Furthermore, mechanical stress inhibits Dll4 expression and leader cell formation in the monolayer. Collectively, our findings suggest that a reduction of mechanical force near the boundary promotes Notch1-Dll4 signalling to dynamically regulate the density of leader cells during collective cell migration.

  1. The effects of notch filters on the correlation properties of a PN signal

    Science.gov (United States)

    Sussman, S. M.; Ferrari, E. J.

    1974-01-01

    With wideband pseudo-noise (PN) communications systems, it is sometimes desirable to supplement the inherent interference rejection capabilities by adding notch filters to attenuate relatively narrowband interference. This correspondence presents an investigation of the effects of notch filters on the performance of PN correlation receivers. A theoretical analysis of the correlation drop due to filter distortion has been conducted and confirmed by experimentation. Additional measurements and analysis have established the trade-off between correlation drop and interference suppression as a function of interference bandwidth. A typical result is that by incurring a penalty of a 1-dB drop in correlation peak, interfering signals having bandwidths of 2 to 3% of the PN chip rate can be attenuated by 25 dB.

  2. Correlation between changes of pulmonary function and Notch1,Notch2/Jagged1,Jagged2 signaling pathway in adjuvant arthritis rats%佐剂关节炎大鼠肺功能变化与Notch1、Notch2/Jagged1、Jagged2通路的相关性

    Institute of Scientific and Technical Information of China (English)

    万磊; 刘健; 程园园; 冯云霞; 刘磊; 黄传兵; 汪元

    2012-01-01

    in lungs significantly decreased ( P <0. 05 ,P <0. 01 ). The correlation analysis indicated that there were significant positive correlations between FVC and Jagged1, FEV1/FVC and Notch1, FEF50 and Jagged2; FEF75 was positively correlated with MAC and MDC respectively, while negatively correlated with Jaggedl ( P < 0. 05, P < 0. 01 ). Conclusion While arthritis occurs in A A rats, pulmonary function declines and significantly correlates with the expression of Notch receptor/ligand, suggesting that the deposition of immune complex in pulmonary following injection of CFA activates Notch signaling pathway, and results in further decline of pulmonary function by signaling cascades.

  3. Notch信号通路在脑缺血的研究进展%The advance of notch signal-pathway in cerebral ischemia

    Institute of Scientific and Technical Information of China (English)

    周强

    2015-01-01

    Notch信号通路对中枢神经系统、血管细胞及免疫细胞生长分化发挥重要的调节作用.脑血管疾病引起的脑缺血激活Notch信号通路,活化的Notch信号通路调控神经前体细胞增殖和分化、介导炎症介质释放和促进血管细胞生成等在神经损伤修复、炎症反应、血管缺血区血管生成等起重要的调节作用.此外,Notch还与遗传性疾病CADASIL发病有关.本文就Notch信号通路在脑血管病中的作用及机制进行了分析.%Notch signal-pathway exerts a signiifcance regulatory role in central nervous system, vascular cells, and immune cell. Notch signal-pathway activated by cerebral ischemia regulates nerve damage repair, inlfammation, and angiogenesis in vascular ischemia area through regulating the proliferation and development of neuronal precursor cell, mediating inlfammatory factors releasing, and promote angiogenesis. Additionally, Notch signal-pathway is associated with the development of cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy. In the present, the mechanism of notch signal-pathway involved in cerebrovascular disease is analyzed.

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

    Science.gov (United States)

    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.

  5. Notch1 signaling inhibits growth of EC109 esophageal carcinoma cells through downmodulation of HPV18 E6/E7 gene expression

    Institute of Scientific and Technical Information of China (English)

    Kejie ZHANG; Quanyi LU; Xiaoqing NIU; Peng ZHANG; Jiangning ZHAO; Zhao WANG; Jiasheng HU; Pu LI; Wenli LIU

    2009-01-01

    Aim:To investigate the role of the Notch1 signaling pathway in growth arrest of an esophageal carcinoma cell line (EC109)in vitro and the mechanism involved.Methods: An intracellular domain of Notch1 (ICN) was transfected into cultured EC109 cells by lipofectamine transfection.Subsequently,the proliferation of the transfected cells was measured by an MTF assay.Cell cycle distribution was ana-lyzed by flow cytometry.Human papillomavirus type 18 (HPV18) E6/E7 mRNA expression was detected by RT-PCR,and p53 protein expression was detected by Western blot.Results: Activation of Notch1 signaling resulted in inhibition of EC109 cell proliferation with the induction of G2/M arrest,downmodulation of HPV18 E6/E7 gene expression,and upregulation of p53 expression.Conclusion: Repression of HPV18 E6/E7 expression by Notch1 signaling results in the activation of p53-mediated pathways with concomitant growth suppression of HPV18-positive EC109 cells.

  6. Endothelial cells downregulate apolipoprotein D expression in mural cells through paracrine secretion and Notch signaling.

    Science.gov (United States)

    Pajaniappan, Mohanasundari; Glober, Nancy K; Kennard, Simone; Liu, Hua; Zhao, Ning; Lilly, Brenda

    2011-09-01

    Endothelial and mural cell interactions are vitally important for proper formation and function of blood vessels. These two cell types communicate to regulate multiple aspects of vessel function. In studying genes regulated by this interaction, we identified apolipoprotein D (APOD) as one gene that is downregulated in mural cells by coculture with endothelial cells. APOD is a secreted glycoprotein that has been implicated in governing stress response, lipid metabolism, and aging. Moreover, APOD is known to regulate smooth muscle cells and is found in abundance within atherosclerotic lesions. Our data show that the regulation of APOD in mural cells is bimodal. Paracrine secretion by endothelial cells causes partial downregulation of APOD expression. Additionally, cell contact-dependent Notch signaling plays a role. NOTCH3 on mural cells promotes the downregulation of APOD, possibly through interaction with the JAGGED-1 ligand on endothelial cells. Our results show that NOTCH3 contributes to the downregulation of APOD and by itself is sufficient to attenuate APOD transcript expression. In examining the consequence of decreased APOD expression in mural cells, we show that APOD negatively regulates cell adhesion. APOD attenuates adhesion by reducing focal contacts; however, it has no effect on stress fiber formation. These data reveal a novel mechanism in which endothelial cells control neighboring mural cells through the downregulation of APOD, which, in turn, influences mural cell function by modulating adhesion.

  7. Reciprocal upregulation of Notch signaling molecules in hematopoietic progenitor and mesenchymal stromal cells

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    Kikuchi Y

    2011-01-01

    Full Text Available Although mesenchymal stem cells (MSCs play pivotal supportive roles in hematopoiesis, how they interact with hematopoietic stem cells (HSCs is not well understood. We investigated the interaction between HSCs and surrogate MSCs (C3H10T1/2 stromal cells, focusing on the molecular events induced by cell contact of these bipartite populations. C3H10T1/2 is a mesenchymal stromal cell line that can be induced to differentiate into preadipocytes (A54 and myoblasts (M1601. The stromal cell derivatives were cocultured with murine HSCs (Lineage-Sca1+, and gene expression profiles in stromal cells and HSCs were compared before and after the coculture. HSCs gave rise to cobblestone areas only on A54 cells, with ninefold more progenitors than on M1601 or undifferentiated C3H10T1/2 cells. Microarray-based screening and a quantitative reverse transcriptase directed-polymerase chain reaction showed that the levels of Notch ligands (Jagged1 and Delta-like 3 were increased in A54 cells upon interaction with HSCs. On the other hand, the expression of Notch1 and Hes1 was upregulated in the HSCs cocultured with A54 cells. A transwell assay revealed that the reciprocal upregulation was dependent on cell-to-cell contact. The result suggested that in the hematopoietic niche, HSCs help MSCs to produce Notch ligands, and in turn, MSCs help HSCs to express Notch receptor. Such a reciprocal upregulation would reinforce the downstream signaling to determine the fate of hematopoietic cell lineage. Clarification of the initiating events on cell contact should lead to the identification of specific molecular targets to facilitate HSC engraftment in transplantation therapy.

  8. Notch signaling pathway and glioma stem cell niche%Notch信号通路与脑胶质瘤干细胞的niche

    Institute of Scientific and Technical Information of China (English)

    林才厚; 郑宗清; 邱献新; 林志雄

    2013-01-01

    A small fraction of tumor stem cells exist in glioma and play a key role in the tumorigenesis and propagation of glioma.They have a close relationship with their niche that offers structural and functional support.In glioma niche,vascular endothelial cells can provide Notch ligands for cancer stem cells to activate Notch signaling pathway and contact with other signaling pathways,maintaining the tumor stem cell self-renewal and increasing resistance of brain tumor stem cells to radiotherapy.Therefore,Notch signaling pathway is considered to be a new therapeutic target of glioma.%研究表明极少数量肿瘤干细胞存在于脑胶质瘤中,但在其发生发展中起关键作用.脑胶质瘤干细胞与为其提供结构和功能支持的血管niche关系密切.在脑胶质瘤niche中,血管内皮细胞可以提供Notch配体给肿瘤干细胞,激活Notch信号通路,并与其他信号通路构成串话,维持肿瘤干细胞的自我更新,增加脑肿瘤干细胞对放疗的抵抗性.因此,Notch信号通路被认为是脑胶质瘤新的治疗靶点.

  9. The EGF repeat-specific O-GlcNAc-transferase Eogt interacts with notch signaling and pyrimidine metabolism pathways in Drosophila.

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    Reto Müller

    Full Text Available The O-GlcNAc transferase Eogt modifies EGF repeats in proteins that transit the secretory pathway, including Dumpy and Notch. In this paper, we show that the Notch ligands Delta and Serrate are also substrates of Eogt, that mutation of a putative UDP-GlcNAc binding DXD motif greatly reduces enzyme activity, and that Eogt and the cytoplasmic O-GlcNAc transferase Ogt have distinct substrates in Drosophila larvae. Loss of Eogt is larval lethal and disrupts Dumpy functions, but does not obviously perturb Notch signaling. To identify novel genetic interactions with eogt, we investigated dominant modification of wing blister formation caused by knock-down of eogt. Unexpectedly, heterozygosity for several members of the canonical Notch signaling pathway suppressed wing blister formation. And importantly, extensive genetic interactions with mutants in pyrimidine metabolism were identified. Removal of pyrimidine synthesis alleles suppressed wing blister formation, while removal of uracil catabolism alleles was synthetic lethal with eogt knock-down. Therefore, Eogt may regulate protein functions by O-GlcNAc modification of their EGF repeats, and cellular metabolism by affecting pyrimidine synthesis and catabolism. We propose that eogt knock-down in the wing leads to metabolic and signaling perturbations that increase cytosolic uracil levels, thereby causing wing blister formation.

  10. Molecular Signalling in Hepatocellular Carcinoma: Role of and Crosstalk among Wnt/β-Catenin, Sonic Hedgehog, Notch and Dickkopf-1

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    Alexandros Giakoustidis

    2015-01-01

    Full Text Available Hepatocellular carcinoma is the sixth most common cancer worldwide. In the majority of cases, there is evidence of existing chronic liver disease from a variety of causes including viral hepatitis B and C, alcoholic liver disease and nonalcoholic steatohepatitis. Identification of the signalling pathways used by hepatocellular carcinoma cells to proliferate, invade or metastasize is of paramount importance in the discovery and implementation of successfully targeted therapies. Activation of Wnt/β-catenin, Notch and Hedgehog pathways play a critical role in regulating liver cell proliferation during development and in controlling crucial functions of the adult liver in the initiation and progression of human cancers. β-catenin was identified as a protein interacting with the cell adhesion molecule E-cadherin at the cell-cell junction, and has been shown to be one of the most important mediators of the Wnt signalling pathway in tumourigenesis. Investigations into the role of Dikkopf-1 in hepatocellular carcinoma have demonstrated controversial results, with a decreased expression of Dickkopf-1 and soluble frizzled-related protein in various cancers on one hand, and as a possible negative prognostic indicator of hepatocellular carcinoma on the other. In the present review, the authors focus on the Wnt/β-catenin, Notch and Sonic Hedgehog pathways, and their interaction with Dikkopf-1 in hepatocellular carcinoma.

  11. Notch pathway activation contributes to inhibition of C2C12 myoblast differentiation by ethanol.

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    Michelle A Arya

    Full Text Available The loss of muscle mass in alcoholic myopathy may reflect alcohol inhibition of myogenic cell differentiation into myotubes. Here, using a high content imaging system we show that ethanol inhibits C2C12 myoblast differentiation by reducing myogenic fusion, creating smaller and less complex myotubes compared with controls. Ethanol administration during C2C12 differentiation reduced MyoD and myogenin expression, and microarray analysis identified ethanol activation of the Notch signaling pathway target genes Hes1 and Hey1. A reporter plasmid regulated by the Hes1 proximal promoter was activated by alcohol treatment in C2C12 cells. Treatment of differentiating C2C12 cells with a gamma secretase inhibitor (GSI abrogated induction of Hes1. On a morphological level GSI treatment completely rescued myogenic fusion defects and partially restored other myotube parameters in response to alcohol. We conclude that alcohol inhibits C2C12 myoblast differentiation and the inhibition of myogenic fusion is mediated by Notch pathway activation.

  12. Evidence for the Induction of Key Components of the NOTCH Signaling Pathway via Deltamethrin and Azamethiphos Treatment in the Sea Louse Caligus rogercresseyi

    Science.gov (United States)

    Boltaña, Sebastian; Chávez-Mardones, Jaqueline; Valenzuela-Muñoz, Valentina; Gallardo-Escárate, Cristian

    2016-01-01

    The extensive use of organophosphates and pyrethroids in the aquaculture industry has negatively impacted parasite sensitivity to the delousing effects of these antiparasitics, especially among sea lice species. The NOTCH signaling pathway is a positive regulator of ABC transporter subfamily C expression and plays a key role in the generation and modulation of pesticide resistance. However, little is known about the molecular mechanisms behind pesticide resistance, partly due to the lack of genomic and molecular information on the processes involved in the resistance mechanism of sea lice. Next-generation sequencing technologies provide an opportunity for rapid and cost-effective generation of genome-scale data. The present study, through RNA-seq analysis, determined that the sea louse Caligus rogercresseyi (C. rogercresseyi) specifically responds to the delousing drugs azamethiphos and deltamethrin at the transcriptomic level by differentially activating mRNA of the NOTCH signaling pathway and of ABC genes. These results suggest that frequent antiparasitic application may increase the activity of inhibitory mRNA components, thereby promoting inhibitory NOTCH output and conditions for increased resistance to delousing drugs. Moreover, data analysis underscored that key functions of NOTCH/ABC components were regulated during distinct phases of the drug response, thus indicating resistance modifications in C. rogercresseyi resulting from the frequent use of organophosphates and pyrethroids. PMID:27187362

  13. Notch信号通路与胰腺发育%Notch Signaling Pathway in Pancreatic Development

    Institute of Scientific and Technical Information of China (English)

    张涛

    2011-01-01

    Notch信号转导通路作为一种进化上保守的相邻细胞间的相互作用机制,参与了细胞的命运决定、自我更新、分化、增值、存活以及凋亡等诸多过程,调控着动物组织和器官的发生、发育和再生.目前,多因子多信号对胰腺发育的时空调节机制已成为研究热点.就Notch信号通路的结构特点及其在胰腺发育中的研究进展作一综述.%As an evolutionarily conserved mechanism of communication between back-fence cells, Notch signaling pathway involved in cell-fate specification, self-renewal, differentiation, proliferation, survival and apoptosis throughout organic morphogenesis, development and regeneration in animal species. Recently, the temporal-spatial regulation mechanism of multiple factors signals on pancreatic development has been becoming the focus of study. The structural characteristics of Notch signaling component and its roles in pancreas development were studied.

  14. Regulation of differentiation flux by Notch signalling influences the number of dopaminergic neurons in the adult brain

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    Niurka Trujillo-Paredes

    2016-03-01

    Full Text Available Notch signalling is a well-established pathway that regulates neurogenesis. However, little is known about the role of Notch signalling in specific neuronal differentiation. Using Dll1 null mice, we found that Notch signalling has no function in the specification of mesencephalic dopaminergic neural precursor cells (NPCs, but plays an important role in regulating their expansion and differentiation into neurons. Premature neuronal differentiation was observed in mesencephalons of Dll1-deficient mice or after treatment with a Notch signalling inhibitor. Coupling between neurogenesis and dopaminergic differentiation was indicated from the coincident emergence of neuronal and dopaminergic markers. Early in differentiation, decreasing Notch signalling caused a reduction in NPCs and an increase in dopaminergic neurons in association with dynamic changes in the proportion of sequentially-linked dopaminergic NPCs (Msx1/2+, Ngn2+, Nurr1+. These effects in differentiation caused a significant reduction in the number of dopaminergic neurons produced. Accordingly, Dll1 haploinsufficient adult mice, in comparison with their wild-type littermates, have a consistent reduction in neuronal density that was particularly evident in the substantia nigra pars compacta. Our results are in agreement with a mathematical model based on a Dll1-mediated regulatory feedback loop between early progenitors and their dividing precursors that controls the emergence and number of dopaminergic neurons.

  15. Notch1 hallmarks fibrillary depositions in sporadic Alzheimer’s disease

    OpenAIRE

    Brai, Emanuele; Raio, Noemi Alina; Alberi, Lavinia

    2016-01-01

    Background Notch1 signaling is a cellular cascade with a fundamental role from brain development to adult brain function. Reduction in Notch1 affects synaptic plasticity, memory and olfaction. On the other hand, Notch1 overactivation after brain injury is detrimental for neuronal survival. Some familial Alzheimer’s disease (FAD) mutations in Presenilins can affect Notch1 processing/activation. Others report that Notch1 is overexpressed in sporadic Alzheimer’s disease (AD). These works indicat...

  16. Effect of soluble Jagged1-mediated inhibition of Notch signaling on proliferation and differentiation of an adipocyte progenitor cell model

    OpenAIRE

    Urs, Sumithra; Turner, Bryce; Tang, Yuefeng; Rostama, Bahman; Small, Deena; Liaw, Lucy

    2012-01-01

    Adipose tissue development is dependent on multiple signaling mechanisms and cell-cell interactions that regulate adipogenesis, angiogenesis and extracellular remodeling. The Notch signaling pathway is an important cell-fate determinant whose role in adipogenesis is not clearly defined. To address this issue, we examined the effect of inhibition of Notch signaling by soluble-Jagged1 in the 3T3-L1 preadipocyte line. In vitro, soluble-Jagged1 expression in 3T3-L1 cells altered cell morphology, ...

  17. Fast synchronization of ultradian oscillators controlled by delta-notch signaling with cis-inhibition.

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    Hendrik B Tiedemann

    2014-10-01

    Full Text Available While it is known that a large fraction of vertebrate genes are under the control of a gene regulatory network (GRN forming a clock with circadian periodicity, shorter period oscillatory genes like the Hairy-enhancer-of split (Hes genes are discussed mostly in connection with the embryonic process of somitogenesis. They form the core of the somitogenesis-clock, which orchestrates the periodic separation of somites from the presomitic mesoderm (PSM. The formation of sharp boundaries between the blocks of many cells works only when the oscillators in the cells forming the boundary are synchronized. It has been shown experimentally that Delta-Notch (D/N signaling is responsible for this synchronization. This process has to happen rather fast as a cell experiences at most five oscillations from its 'birth' to its incorporation into a somite. Computer simulations describing synchronized oscillators with classical modes of D/N-interaction have difficulties to achieve synchronization in an appropriate time. One approach to solving this problem of modeling fast synchronization in the PSM was the consideration of cell movements. Here we show that fast synchronization of Hes-type oscillators can be achieved without cell movements by including D/N cis-inhibition, wherein the mutual interaction of DELTA and NOTCH in the same cell leads to a titration of ligand against receptor so that only one sort of molecule prevails. Consequently, the symmetry between sender and receiver is partially broken and one cell becomes preferentially sender or receiver at a given moment, which leads to faster entrainment of oscillators. Although not yet confirmed by experiment, the proposed mechanism of enhanced synchronization of mesenchymal cells in the PSM would be a new distinct developmental mechanism employing D/N cis-inhibition. Consequently, the way in which Delta-Notch signaling was modeled so far should be carefully reconsidered.

  18. Targeting notch pathway enhances rapamycin antitumor activity in pancreas cancers through PTEN phosphorylation

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    Vo Kevin

    2011-11-01

    Full Text Available Abstract Background Pancreas cancer is one of most aggressive human cancers with the survival rate for patients with metastatic pancreas cancer at 5-6 months. The poor survival demonstrates a clear need for better target identification, drug development and new therapeutic strategies. Recent discoveries have shown that the role for Notch pathway is important in both development and cancer. Its contribution to oncogenesis also involves crosstalks with other growth factor pathways, such as Akt and its modulator, PTEN. The mounting evidence supporting a role for Notch in cancer promotion and survival suggests that targeting this pathway alone or in combination with other therapeutics represents a promising therapeutic strategy. Results Using a pancreas cancer tissue microarray, we noted that Jagged1, Notch3 and Notch4 are overexpressed in pancreas tumors (26%, 84% and 31% respectively, whereas Notch1 is expressed in blood vessels. While there was no correlation between Notch receptor expression and survival, stage or tumor grade, Notch3 was associated with Jagged1 and EGFR expression, suggesting a unique relationship between Notch3 and Jagged1. Inhibition of the Notch pathway genetically and with gamma-secretase inhibitor (GSI resulted in tumor suppression and enhanced cell death. The observed anti-tumor activity appeared to be through Akt and modulation of PTEN phosphorylation. We discovered that transcriptional regulation of RhoA by Notch is important for PTEN phosphorylation. Finally, the mTOR inhibitor Rapamycin enhanced the effect of GSI on RhoA expression, resulting in down regulation of phospho-Akt and increased in vitro tumor cytotoxity. Conclusions Notch pathway plays an important role in maintaining pancreas tumor phenotype. Targeting this pathway represents a reasonable strategy for the treatment of pancreas cancers. Notch modulates the Akt pathway through regulation of PTEN phosphorylation, an observation that has not been made

  19. Aberrant Notch Signaling in the Bone Marrow Microenvironment of Acute Lymphoid Leukemia Suppresses Osteoblast-Mediated Support of Hematopoietic Niche Function.

    Science.gov (United States)

    Wang, Weihuan; Zimmerman, Grant; Huang, Xiaoran; Yu, Shuiliang; Myers, Jay; Wang, Yiwei; Moreton, Stephen; Nthale, Joseph; Awadallah, Amad; Beck, Rose; Xin, Wei; Wald, David; Huang, Alex Y; Zhou, Lan

    2016-03-15

    More than half of T-cell acute lymphoblastic leukemia (T-ALL) patients harbor gain-of-function mutations in the intracellular domain of Notch1. Diffuse infiltration of the bone marrow commonly occurs in T-ALL and relapsed B-cell acute lymphoblastic leukemia patients, and is associated with worse prognosis. However, the mechanism of leukemia outgrowth in the marrow and the resulting biologic impact on hematopoiesis are poorly understood. Here, we investigated targetable cellular and molecular abnormalities in leukemia marrow stroma responsible for the suppression of normal hematopoiesis using a T-ALL mouse model and human T-ALL xenografts. We found that actively proliferating leukemia cells inhibited normal hematopoietic stem and progenitor cell (HSPC) proliferation and homing to the perivascular region. In addition, leukemia development was accompanied by the suppression of the endosteum-lining osteoblast population. We further demonstrated that aberrant Notch activation in the stroma plays an important role in negatively regulating the expression of CXLC12 on osteoblasts and their differentiation. Notch blockade reversed attenuated HSPC cycling, leukemia-associated abnormal blood lineage distribution, and thrombocytopenia as well as recovered osteoblast and HSPC abundance and improved the hematopoietic-supportive functions of osteoblasts. Finally, we confirmed that reduced osteoblast frequency and enhanced Notch signaling were also features of the marrow stroma of human ALL tissues. Collectively, our findings suggest that therapeutically targeting the leukemia-infiltrated hematopoietic niche may restore HSPC homeostasis and improve the outcome of ALL patients. PMID:26801976

  20. Notch Signaling Coordinates Progenitor Cell-Mediated Biliary Regeneration Following Partial Hepatectomy

    Science.gov (United States)

    Lu, Jie; Zhou, Yingqun; Hu, Tianyuan; Zhang, Hui; Shen, Miao; Cheng, Ping; Dai, Weiqi; Wang, Fan; Chen, Kan; Zhang, Yan; Wang, Chengfeng; Li, Jingjing; Zheng, Yuanyuan; Yang, Jing; Zhu, Rong; Wang, Jianrong; Lu, Wenxia; Zhang, Huawei; Wang, Junshan; Xia, Yujing; De Assuncao, Thiago M.; Jalan-Sakrikar, Nidhi; Huebert, Robert C.; Bin Zhou; Guo, Chuanyong

    2016-01-01

    Aberrant transcriptional regulation contributes to the pathogenesis of both congenital and adult forms of liver disease. Although the transcription factor RBPJ is essential for liver morphogenesis and biliary development, its specific function in the differentiation of hepatic progenitor cells (HPC) has not been investigated, and little is known about its role in adult liver regeneration. HPCs are bipotent liver stem cells that can self-replicate and differentiate into hepatocytes or cholangiocytes in vitro. HPCs are thought to play an important role in liver regeneration and repair responses. While the coordinated repopulation of both hepatocyte and cholangiocyte compartment is pivotal to the structure and function of the liver after regeneration, the mechanisms coordinating biliary regeneration remain vastly understudied. Here, we utilized complex genetic manipulations to drive liver-specific deletion of the Rbpj gene in conjunction with lineage tracing techniques to delineate the precise functions of RBPJ during biliary development and HPC-associated biliary regeneration after hepatectomy. Furthermore, we demonstrate that RBPJ promotes HPC differentiation toward cholangiocytes in vitro and blocks hepatocyte differentiation through mechanisms involving Hippo-Notch crosstalk. Overall, this study demonstrates that the Notch-RBPJ signaling axis critically regulates biliary regeneration by coordinating the fate decision of HPC and clarifies the molecular mechanisms involved. PMID:26951801

  1. Notch 信号通路调节巨噬细胞极化研究进展%Notch Signaling Pathway with the Polarization of Macrophages

    Institute of Scientific and Technical Information of China (English)

    李红蓉; 孙颖(综述); 常成成; 贾振华(审校)

    2015-01-01

    巨噬细胞因其较强的可塑性和功能多样性,在多种疾病的病变进程中发挥重要作用。 Notch信号通路是巨噬细胞生物学功能的关键调节器,并且和其他多种信号通路有着复杂的网络联系。文中就Notch信号通路的传导及其对巨噬细胞极化的调节进行综述。%Macrophages play an important role in the pathogenesis of many diseases because of its plasticity and diversity.The Notch signaling pathway is a key regulator of the biological function of macrophage and has a complex network connection with many other signaling pathways.This paper reviews the conduction of Notch signaling pathway and its regulation on the polarization of macro-phages.

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

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    Warrander Fiona

    2009-06-01

    Full Text Available Abstract 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.

  3. Effect of IL-17 monoclonal antibody Secukinumab combined with IL-35 blockade of Notch signaling pathway on the invasive capability of hepatoma cells.

    Science.gov (United States)

    Li, H Ch; Zhang, Y X; Liu, Y; Wang, Q Sh

    2016-07-14

    We investigated the effect of the IL-17 monoclonal antibody Secukinumab combined with IL-35 in the blockade of the Notch signaling pathway on the invasive capability of hepatoma cells. We examined the effects of IL-17 antibody or IL-35 treatment alone or in combination on cell invasion and migration capabilities with Transwell chambers. The mRNA levels of Hes1, Hes5, and Hey1 were tested using quantitative polymerase chain reaction. The protein expression of N1ICD, Snail, and E-cadherin protein expressions were measured with western blot. The expression of Hes1, Hes5, Hey1 and N1ICD were all very high in hepatoma cell lines, and were positively correlated with the invasive migration capabilities of the cells. The combination of IL-17 monoclonal antibody Secukinumab with IL-35 could effectively inhibit the Notch signaling pathway, as well as the invasive migration of the cells. Snail and E-cadherin are involved in the migration of hepatoma cells, and it has been established that Snail can regulate the expression of E-cadherin. IL-17 monoclonal antibody Secukinumab combined with IL-35 can increase E-cadherin and decrease Snail expression, which are positively correlated with cell invasive migration capabilities. Overall, treatment with both IL-17 antibody and IL-35 is more effective than each treatment alone. Notch signaling is activated in hepatoma cell lines and increases with the enhancement of cell invasive migration capabilities. IL-17 monoclonal antibody Secukinumab combined with IL-35 can block the Notch signaling pathway, simultaneously reducing the invasive migration capability of hepatoma cells.

  4. Clinicopathological significance of altered Notch signaling in extrahepatic cholangiocarcinoma and gallbladder carcinoma

    Institute of Scientific and Technical Information of China (English)

    Hyun Ah Yoon; Myung Hwan Noh; Byung Geun Kim; Ji Sun Han; Jin Seok Jang; Seok Ryeol Choi; Jin Sook Jeong; Jin Ho Chun

    2011-01-01

    AIM: To investigate the role and clinicopathological significance of aberrant expression of Notch receptors and Delta-like ligand-4 (DLL4) in extrahepatic cholangiocarcinoma and gallbladder carcinoma.METHODS: One hundred and ten patients had surgically resected extrahepatic cholangiocarcinoma (CC) and gallbladder carcinoma specimens examined by immunohistochemistry of available paraffin blocks. Immunohistochemistry was performed using anti-Notch receptors 1-4 and anti-DLL4 antibodies. We scored the immunopositivity of Notch receptors and DLL4 expression by percentage of positive tumor cells with cytoplasmic expression and intensity of immunostaining. Coexistent nuclear localization was evaluated. Clinicopathological parameters and survival data were compared with the expression of Notch receptors 1-4 and DLL4.RESULTS: Notch receptor proteins showed in the cytoplasm with or without nuclear expression in cancer cells, as well as showing weak cytoplasmic expression in non-neoplastic cells. By semiquantitative evaluation, positive immunostaining of Notch receptor 1 was detected in 96 cases (87.3%), Notch receptor 2 in 97 (88.2%), Notch receptor 3 in 97 (88.2%), Notch receptor 4 in 103 (93.6), and DLL4 in 84 (76.4%). In addition, coexistent nuclear localization was noted [Notch receptor 1; 18 cases (18.8%), Notch receptor 2; 40 (41.2%), Notch receptor 3; 32 (33.0%), Notch receptor 4; 99 (96.1%), DLL4; 48 (57.1%)]. Notch receptor 1 expression was correlated with advanced tumor, node, metastasis (TNM) stage (P = 0.043), Notch receptor 3 with advanced T stage (P = 0.017), tendency to express in cases with nodal metastasis (P = 0.065) and advanced TNM stage (P = 0.052). DLL4 expression tended to be related to less histological differentiation (P = 0.095). Coexistent nuclear localization of Notch receptor 3 was related to no nodal metastasis (P = 0.027) and Notch receptor 4 with less histological differentiation (P = 0.036), while DLL4 tended to be related inversely with T

  5. Osteoprotegerin inhibits calcification of vascular smooth muscle cell via down regulation of the Notch1-RBP-Jκ/Msx2 signaling pathway.

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    Shaoqiong Zhou

    Full Text Available OBJECTIVE: Vascular calcification is a common pathobiological process which occurs among the elder population and in patients with diabetes and chronic kidney disease. Osteoprotegerin, a secreted glycoprotein that regulates bone mass, has recently emerged as an important regulator of the development of vascular calcification. However, the mechanism is not fully understood. The purpose of this study is to explore novel signaling mechanisms of osteoprotegerin in the osteoblastic differentiation in rat aortic vascular smooth muscle cells (VSMCs. METHODS AND RESULTS: VSMCs were isolated from thoracic aorta of Sprague Dawley rats. Osteoblastic differentiation of VSMCs was induced by an osteogenic medium. We confirmed by Von Kossa staining and direct cellular calcium measurement that mineralization was significantly increased in VSMCs cultured in osteogenic medium; consistent with an enhanced alkaline phosphatase activity. This osteoblastic differentiation in VSMCs was significantly reduced by the addition of osteoprotegerin in a dose responsive manner. Moreover, we identified, by real-time qPCR and western blotting, that expression of Notch1 and RBP-Jκ were significantly up-regulated in VSMCs cultured in osteogenic medium at both the mRNA and protein levels, these effects were dose-dependently abolished by the treatment of osteoprotegerin. Furthermore, we identified that Msx2, a downstream target of the Notch1/RBP-Jκ signaling, was markedly down-regulated by the treatment of osteoprotegerin. CONCLUSION: Osteoprotegerin inhibits vascular calcification through the down regulation of the Notch1-RBP-Jκ signaling pathway.

  6. Coordinated control of Notch/Delta signalling and cell cycle progression drives lateral inhibition-mediated tissue patterning

    Science.gov (United States)

    Hadjivasiliou, Zena; Bonin, Hope; He, Li; Perrimon, Norbert; Charras, Guillaume; Baum, Buzz

    2016-01-01

    Coordinating cell differentiation with cell growth and division is crucial for the successful development, homeostasis and regeneration of multicellular tissues. Here, we use bristle patterning in the fly notum as a model system to explore the regulatory and functional coupling of cell cycle progression and cell fate decision-making. The pattern of bristles and intervening epithelial cells (ECs) becomes established through Notch-mediated lateral inhibition during G2 phase of the cell cycle, as neighbouring cells physically interact with each other via lateral contacts and/or basal protrusions. Since Notch signalling controls cell division timing downstream of Cdc25, ECs in lateral contact with a Delta-expressing cell experience higher levels of Notch signalling and divide first, followed by more distant neighbours, and lastly Delta-expressing cells. Conversely, mitotic entry and cell division makes ECs refractory to lateral inhibition signalling, fixing their fate. Using a combination of experiments and computational modelling, we show that this reciprocal relationship between Notch signalling and cell cycle progression acts like a developmental clock, providing a delimited window of time during which cells decide their fate, ensuring efficient and orderly bristle patterning. PMID:27226324

  7. Coordinated control of Notch/Delta signalling and cell cycle progression drives lateral inhibition-mediated tissue patterning.

    Science.gov (United States)

    Hunter, Ginger L; Hadjivasiliou, Zena; Bonin, Hope; He, Li; Perrimon, Norbert; Charras, Guillaume; Baum, Buzz

    2016-07-01

    Coordinating cell differentiation with cell growth and division is crucial for the successful development, homeostasis and regeneration of multicellular tissues. Here, we use bristle patterning in the fly notum as a model system to explore the regulatory and functional coupling of cell cycle progression and cell fate decision-making. The pattern of bristles and intervening epithelial cells (ECs) becomes established through Notch-mediated lateral inhibition during G2 phase of the cell cycle, as neighbouring cells physically interact with each other via lateral contacts and/or basal protrusions. Since Notch signalling controls cell division timing downstream of Cdc25, ECs in lateral contact with a Delta-expressing cell experience higher levels of Notch signalling and divide first, followed by more distant neighbours, and lastly Delta-expressing cells. Conversely, mitotic entry and cell division makes ECs refractory to lateral inhibition signalling, fixing their fate. Using a combination of experiments and computational modelling, we show that this reciprocal relationship between Notch signalling and cell cycle progression acts like a developmental clock, providing a delimited window of time during which cells decide their fate, ensuring efficient and orderly bristle patterning. PMID:27226324

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

    Science.gov (United States)

    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. PMID:27263934

  9. Potential involvement of Notch1 signalling in the pathogenesis of primary cutaneous CD30-positive lymphoproliferative disorders

    DEFF Research Database (Denmark)

    Kamstrup, M.R.; Ralfkiaer, E.; Skovgaard, G.L.;

    2008-01-01

    cutaneous CD30+ lymphoproliferative disorders. Methods Immunohistochemistry of formalin-fixed, paraffin-embedded skin samples from 12 patients with lymphomatoid papulosis (LyP) and 11 patients with primary cutaneous anaplastic large cell lymphoma (ALCL). Immunofluorescence studies of fresh skin samples......Background The central role of Notch signalling in T-cell development and oncogenesis raises the question of the importance of this pathway in cutaneous T-cell lymphomas. Objectives To investigate the pattern of expression of Notch and its ligands, Jagged and Delta, in skin samples of primary...

  10. Oridonin inhibits tumor growth and metastasis through anti-angiogenesis by blocking the Notch signaling.

    Directory of Open Access Journals (Sweden)

    Yanmin Dong

    Full Text Available While significant progress has been made in understanding the anti-inflammatory and anti-proliferative effects of the natural diterpenoid component Oridonin on tumor cells, little is known about its effect on tumor angiogenesis or metastasis and on the underlying molecular mechanisms. In this study, Oridonin significantly suppressed human umbilical vascular endothelial cells (HUVECs proliferation, migration, and apillary-like structure formation in vitro. Using aortic ring assay and mouse corneal angiogenesis model, we found that Oridonin inhibited angiogenesis ex vivo and in vivo. In our animal experiments, Oridonin impeded tumor growth and metastasis. Immunohistochemistry analysis further revealed that the expression of CD31 and vWF protein in xenografts was remarkably decreased by the Oridonin. Furthermore, Oridonin reinforced endothelial cell-cell junction and impaired breast cancer cell transendothelial migration. Mechanistically, Oridonin not only down-regulated Jagged2 expression and Notch1 activity but also decreased the expression of their target genes. In conclusion, our results demonstrated an original role of Oridonin in inhibiting tumor angiogenesis and propose a mechanism. This study also provides new evidence supporting the central role of Notch in tumor angiogenesis and suggests that Oridonin could be a potential drug candidate for angiogenesis related diseases.

  11. Notch receptors in human choroid plexus tumors.

    Science.gov (United States)

    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 (pnCP compared to CPT. Nuclear expression of Notch1, -2 and -4 was significantly higher in CPT compared to nCP (pnCP 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.

  12. Notch signaling: a novel regulating differentiation mechanism of human umbilical cord blood-derived mesenchymal stem cells into insulin-producing cells in vitro

    Institute of Scientific and Technical Information of China (English)

    HU Yan-hua; WU De-quan; GAO Feng; LI Guo-dong; ZHANG Xin-chen

    2010-01-01

    Background Human umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs) could be induced to differentiate into insulin producing cells (IPCs) in vitro, which have good application potential in the cell replacement treatment of type-1 diabetes. However, the mechanisms regulating this differentiation have remained largely unknown. Notch signaling is critical in cell differentiation. This study investigated whether Notch signaling could regulate the IPCs differentiation of human UCB-MSCs. Methods Using an interfering Notch signaling protocol in vitro, we studied the role of Notch signaling in differentiation of human UCB-MSCs into IPCs. In a control group the induction took place without interfering Notch signaling. Results Human UCB-MSCs expressed the genes of Notch receptors (Notch 1 and Notch 2) and ligands (Jagged 1 and Deltalike 1). Human UCB-MSCs with over-expressing Notch signaling in differentiation resulted in the down-regulation of insulin gene level, proinsulin protein expression, and insulin-positive cells percentage compared with the control group. These results showed that over-expressing Notch signaling inhibited IPCs differentiation. Conversely, when Notch signaling was attenuated by receptor inhibitor, the induced cells increased on average by 3.06-fold (n=4, P<0.001) in insulin gene level, 2.60-fold (n=3, P <0.02) in proinsulin protein expression, and 1.62-fold (n=6, P <0.001) in the rate of IPCs compared with the control group. Notch signaling inhibition significantly promoted IPCs differentiation with about 40% of human UCB-MSCs that converted to IPCs, but these IPCs were not responsive to glucose challenge very well both in vitro and in vivo. Hence, further research has to be carried out in the future. Conclusions Notch signaling may be an important mechanism regulating IPCs differentiation of human UCB-MSCs in vitro and Notch signaling inhibition may be an efficient way to increase the number of IPCs, which may resolve the shortage of

  13. Inhibition of Notch signaling reduces the number of surviving Dclk1+ reserve crypt epithelial stem cells following radiation injury.

    Science.gov (United States)

    Qu, Dongfeng; May, Randal; Sureban, Sripathi M; Weygant, Nathaniel; Chandrakesan, Parthasarathy; Ali, Naushad; Li, Linheng; Barrett, Terrence; Houchen, Courtney W

    2014-03-01

    We have previously reported that doublecortin-like kinase 1 (Dclk1) is a putative intestinal stem cell (ISC) marker. In this report, we evaluated the use of Dclk1 as a marker of surviving ISCs in response to treatment with high-dose total body irradiation (TBI). Both apoptotic and mitotic Dclk1(+) cells were observed 24 h post-TBI associated with a corresponding loss of intestinal crypts observed at 84 h post-TBI. Although the Notch signaling pathway plays an important role in regulating proliferation and lineage commitment within the intestine, its role in ISC function in response to severe genotoxic injury is not yet fully understood. We employed the microcolony assay to functionally assess the effects of Notch inhibition with difluorophenacetyl-l-alanyl-S-phenylglycine t-butyl ester (DAPT) on intestinal crypt stem cell survival following severe (>8 Gy) radiation injury. Following treatment with DAPT, we observed a nearly 50% reduction in the number of surviving Dclk1(+) crypt epithelial cells at 24 h after TBI and similar reduction in the number of surviving small intestinal crypts at 84 h. These data indicate that inhibition of Notch signaling decreases ISC survival following radiation injury, suggesting that the Notch signaling pathway plays an important role in ISC-mediated crypt regeneration. These results also suggest that crypt epithelial cell Dclk1 expression can be used as one potential marker to evaluate the early survival of ISCs following severe radiation injury.

  14. Lineage-specific effects of Notch/Numb signaling in post-embryonic development of the Drosophila brain.

    Science.gov (United States)

    Lin, Suewei; Lai, Sen-Lin; Yu, Huang-Hsiang; Chihara, Takahiro; Luo, Liqun; Lee, Tzumin

    2010-01-01

    Numb can antagonize Notch signaling to diversify the fates of sister cells. We report here that paired sister cells acquire different fates in all three Drosophila neuronal lineages that make diverse types of antennal lobe projection neurons (PNs). Only one in each pair of postmitotic neurons survives into the adult stage in both anterodorsal (ad) and ventral (v) PN lineages. Notably, Notch signaling specifies the PN fate in the vPN lineage but promotes programmed cell death in the missing siblings in the adPN lineage. In addition, Notch/Numb-mediated binary sibling fates underlie the production of PNs and local interneurons from common precursors in the lAL lineage. Furthermore, Numb is needed in the lateral but not adPN or vPN lineages to prevent the appearance of ectopic neuroblasts and to ensure proper self-renewal of neural progenitors. These lineage-specific outputs of Notch/Numb signaling show that a universal mechanism of binary fate decision can be utilized to govern diverse neural sibling differentiations.

  15. The importance of Notch signaling in peripheral T-cell lymphomas

    DEFF Research Database (Denmark)

    Kamstrup, Maria Rørbæk; Biskup, Edyta; Gjerdrum, Lise Mette Rahbek;

    2014-01-01

    Peripheral T-cell lymphomas (PTLs) represent an area of high medical need. Previously, we demonstrated high expression of Notch, a known oncogene, in primary cutaneous anaplastic large cell lymphoma (ALCL). In this study, we performed immunohistochemical staining for Notch1 in lymph nodes from PTL...... ALK- (nine cases) (p > 0.05). In the ALK+ ALCL cell line, Karpas-299, pharmacological inhibition of Notch with γ-secretase inhibitor (GSI) I was far more potent than with GSI IX, XX and XXI with regard to cell viability and apoptosis. In conclusion, PTL tumor cells have prominent Notch1 expression and...

  16. Effect of spinal cord extracts after spinal cord injury on proliferation of rat embryonic neural stem cells and Notch signal pathwayin vitro

    Institute of Scientific and Technical Information of China (English)

    Qing-Zhong Zhou; Ge Zhang; Hai-Bo Long; Fei Lei; Fei Ye; Xu-Feng Jia; Yun-Long Zhou; Jian-Ping Kang; Da-Xiong Feng

    2014-01-01

    Objective:To investigate the effect of the spinal cord extracts(SCE) after spinal cord injuries (SCIs) on the proliferation of rat embryonic neural stem cells(NSCs) and the expressions of mRNA ofNotch1 as well as ofHes1 in this processin vitro.Methods:The experiment was conducted in4 different mediums:NSCs+PBS(GroupA-blank control group),NSCs+SCE with healthySD rats(GroupB-normal control group),NSCs+SCE withSD rats receiving sham-operation treatment (GroupC-sham-operation group) andNSCs+SCE withSCIs rats(GroupD- paraplegic group). Proliferative abilities of4 different groups were analyzed byMTT chromatometry after co-culture for1,2,3,4 and5 d, respectively.The expressions ofNotch1 andHes1 mRNA were also detected withRT-PCR after co-culture for24 and48 h, respectively.Results:After co-culture for1,2,3, 4 and5 d respectively, theMTT values of groupD were significantly higher than those of group A, groupB and groupC(P0.05).Both the expressions ofNotch1 andHes1 mRNA of groupD were significantly higher than those of other3 groups after co-culture for24 h and48 h as well(P0.05).There was no difference in expressions ofNotch1 andHes1 mRNA between24 h and48 h treatment in groupD.Conclusions:SCE could promote the proliferation ofNSCs.It is demonstrated that the microenvironment ofSCI may promote the proliferation ofNSCs.Besides,SCE could increase the expression ofNotch1 andHes1 mRNA of NSC.It can be concluded that theNotch signaling pathway activation is one of the mechanisms that locally injured microenvironment contributes to the proliferation ofENSC afterSCIs.This process may be performed by up-regulating the expressions ofNotch1 andHes1gene.

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

    Science.gov (United States)

    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.

  18. A Disintegrin and Metalloproteinase Domain 17 Regulates Colorectal Cancer Stem Cells and Chemosensitivity Via Notch1 Signaling.

    Science.gov (United States)

    Wang, Rui; Ye, Xiangcang; Bhattacharya, Rajat; Boulbes, Delphine R; Fan, Fan; Xia, Ling; Ellis, Lee M

    2016-03-01

    Evidence is accumulating for the role of cancer stem cells (CSCs) in mediating chemoresistance in patients with metastatic colorectal cancer (mCRC). A disintegrin and metalloproteinase domain 17 (ADAM17; also known as tumor necrosis factor-α-converting enzyme [TACE]) was shown to be overexpressed and to mediate cell proliferation and chemoresistance in CRC cells. However, its role in mediating the CSC phenotype in CRC has not been well-characterized. The objective of the present study was to determine whether ADAM17 regulates the CSC phenotype in CRC and to elucidate the downstream signaling mechanism that mediates cancer stemness. We treated established CRC cell lines and a newly established human CRC cell line HCP-1 with ADAM17-specific small interfering RNA (siRNA) or the synthetic peptide inhibitor TAPI-2. The effects of ADAM17 inhibition on the CSC phenotype and chemosensitivity to 5-fluorouracil (5-FU) in CRC cells were examined. siRNA knockdown and TAPI-2 decreased the protein levels of cleaved Notch1 (Notch1 intracellular domain) and HES-1 in CRC cells. A decrease in the CSC phenotype was determined by sphere formation and ALDEFLUOR assays. Moreover, TAPI-2 sensitized CRC cells to 5-FU by decreasing cell viability and the median lethal dose of 5-FU and increasing apoptosis. We also showed the cleavage and release of soluble Jagged-1 and -2 by ADAM17 in CRC cells. Our studies have elucidated a role of ADAM17 in regulating the CSC phenotype and chemoresistance in CRC cells. The use of drugs that inhibit ADAM17 activity might increase the therapeutic benefit to patients with mCRC and, potentially, those with other solid malignancies.

  19. Analysis of Germline Stem Cell Differentiation Following Loss of GLP-1 Notch Activity in Caenorhabditis elegans.

    Science.gov (United States)

    Fox, Paul M; Schedl, Tim

    2015-09-01

    Stem cells generate the differentiated progeny cells of adult tissues. Stem cells in the Caenorhabditis elegans hermaphrodite germline are maintained within a proliferative zone of ∼230 cells, ∼20 cell diameters in length, through GLP-1 Notch signaling. The distal tip cell caps the germline and supplies GLP-1-activating ligand, and the distal-most germ cells that occupy this niche are likely self-renewing stem cells with active GLP-1 signaling. As germ cells are displaced from the niche, GLP-1 activity likely decreases, yet mitotically cycling germ cells are found throughout the proliferative zone prior to overt meiotic differentiation. Following loss of GLP-1 activity, it remains unclear whether stem cells undergo transit-amplifying (TA) divisions or more directly enter meiosis. To distinguish between these possibilities we employed a temperature-sensitive (ts) glp-1 mutant to manipulate GLP-1 activity. We characterized proliferative zone dynamics in glp-1(ts) mutants at permissive temperature and then analyzed the kinetics of meiotic entry of proliferative zone cells after loss of GLP-1. We found that entry of proliferative zone cells into meiosis following loss of GLP-1 activity is largely synchronous and independent of their distal-proximal position. Furthermore, the majority of cells complete only a single mitotic division before entering meiosis, independent of their distal-proximal position. We conclude that germ cells do not undergo TA divisions following loss of GLP-1 activity. We present a model for the dynamics of the proliferative zone that utilizes cell cycle rate and proliferative zone size and output and incorporates the more direct meiotic differentiation of germ cells following loss of GLP-1 activity.

  20. The convergence of Notch and MAPK signaling specifies the blood progenitor fate in the Drosophila mesoderm.

    Science.gov (United States)

    Grigorian, Melina; Mandal, Lolitika; Hakimi, Manuel; Ortiz, Irma; Hartenstein, Volker

    2011-05-01

    Blood progenitors arise from a pool of pluripotential cells ("hemangioblasts") within the Drosophila embryonic mesoderm. The fact that the cardiogenic mesoderm consists of only a small number of highly stereotypically patterned cells that can be queried individually regarding their gene expression in normal and mutant embryos is one of the significant advantages that Drosophila offers to dissect the mechanism specifying the fate of these cells. We show in this paper that the expression of the Notch ligand Delta (Dl) reveals segmentally reiterated mesodermal clusters ("cardiogenic clusters") that constitute the cardiogenic mesoderm. These clusters give rise to cardioblasts, blood progenitors and nephrocytes. Cardioblasts emerging from the cardiogenic clusters accumulate high levels of Dl, which is required to prevent more cells from adopting the cardioblast fate. In embryos lacking Dl function, all cells of the cardiogenic clusters become cardioblasts, and blood progenitors are lacking. Concomitant activation of the Mitogen Activated Protein Kinase (MAPK) pathway by Epidermal Growth Factor Receptor (EGFR) and Fibroblast Growth Factor Receptor (FGFR) is required for the specification and maintenance of the cardiogenic mesoderm; in addition, the spatially restricted localization of some of the FGFR ligands may be instrumental in controlling the spatial restriction of the Dl ligand to presumptive cardioblasts. PMID:21382367

  1. Notch mRNA expression in Drosophila embryos is negatively regulated at the level of mRNA 3' processing.

    Directory of Open Access Journals (Sweden)

    Andrew K Shepherd

    Full Text Available Notch receptor regulates differentiation of almost all tissues and organs during animal development. Many mechanisms function at the protein level to finely regulate Notch activity. Here we provide evidence for Notch regulation at an earlier step - mRNA 3' processing. Processing at the Notch consensus polyadenylation site appears by default to be suppressed in Drosophila embryos. Interference with this suppression, by a mutation, results in increased levels of polyadenylated Notch mRNA, excess Notch signaling, and severe developmental defects. We propose that Notch mRNA 3' processing is negatively regulated to limit the production of Notch protein and render it a controlling factor in the generation of Notch signaling.

  2. A role of the LIN-12/Notch signaling pathway in diversifying the non-striated egg-laying muscles in C. elegans.

    Science.gov (United States)

    Hale, Jared J; Amin, Nirav M; George, Carolyn; Via, Zachary; Shi, Herong; Liu, Jun

    2014-05-15

    The proper formation and function of an organ is dependent on the specification and integration of multiple cell types and tissues. An example of this is the Caenorhabditis elegans hermaphrodite egg-laying system, which requires coordination between the vulva, uterus, neurons, and musculature. While the genetic constituents of the first three components have been well studied, little is known about the molecular mechanisms underlying the specification of the egg-laying musculature. The egg-laying muscles are non-striated in nature and consist of sixteen cells, four each of type I and type II vulval muscles and uterine muscles. These 16 non-striated muscles exhibit distinct morphology, location, synaptic connectivity and function. Using an RNAi screen targeting the putative transcription factors in the C. elegans genome, we identified a number of novel factors important for the diversification of these different types of egg-laying muscles. In particular, we found that RNAi knockdown of lag-1, which encodes the sole C. elegans ortholog of the transcription factor CSL (CBF1, Suppressor of Hairless, LAG-1), an effector of the LIN-12/Notch pathway, led to the production of extra type I vulval muscles. Similar phenotypes were also observed in animals with down-regulation of the Notch receptor LIN-12 and its DSL (Delta, Serrate, LAG-2) ligand LAG-2. The extra type I vulval muscles in animals with reduced LIN-12/Notch signaling resulted from a cell fate transformation of type II vulval muscles to type I vulval muscles. We showed that LIN-12/Notch was activated in the undifferentiated type II vulval muscle cells by LAG-2/DSL that is likely produced by the anchor cell (AC). Our findings provide additional evidence highlighting the roles of LIN-12/Notch signaling in coordinating the formation of various components of the functional C. elegans egg-laying system. We also identify multiple new factors that play critical roles in the proper specification of the different types

  3. Design and Analysis of Robust Active Damping for LCL Filters using Digital Notch Filters

    DEFF Research Database (Denmark)

    Yao, Wenli; Yang, Yongheng; Zhang, Xiaobin;

    2016-01-01

    the resonance, where the notch frequency should be aligned exactly to the resonant frequency of the LCL filter. However, parameter variations of the LCL filter as well as the time delay appearing in digital control systems will induce resonance drifting, and thus break this alignment, possibly deteriorating......Resonant poles of LCL filters may challenge the entire system stability especially in digital-controlled Pulse Width Modulation (PWM) inverters. In order to tackle the resonance issues, many active damping solutions have been reported. For instance, a notch filter can be employed to damp...... make itself fail to damp the resonance. Specifically, the phase lag can make the current control stable despite of the resonant frequency drifting, when the grid current is fed back. In contrast, in the case of an inverter current feedback control, the influence of the phase lead or lag on the active...

  4. Transcriptional dynamics elicited by a short pulse of notch activation involves feed-forward regulation by E(spl/Hes genes.

    Directory of Open Access Journals (Sweden)

    Ben E Housden

    Full Text Available Dynamic activity of signaling pathways, such as Notch, is vital to achieve correct development and homeostasis. However, most studies assess output many hours or days after initiation of signaling, once the outcome has been consolidated. Here we analyze genome-wide changes in transcript levels, binding of the Notch pathway transcription factor, CSL [Suppressor of Hairless, Su(H, in Drosophila], and RNA Polymerase II (Pol II immediately following a short pulse of Notch stimulation. A total of 154 genes showed significant differential expression (DE over time, and their expression profiles stratified into 14 clusters based on the timing, magnitude, and direction of DE. E(spl genes were the most rapidly upregulated, with Su(H, Pol II, and transcript levels increasing within 5-10 minutes. Other genes had a more delayed response, the timing of which was largely unaffected by more prolonged Notch activation. Neither Su(H binding nor poised Pol II could fully explain the differences between profiles. Instead, our data indicate that regulatory interactions, driven by the early-responding E(splbHLH genes, are required. Proposed cross-regulatory relationships were validated in vivo and in cell culture, supporting the view that feed-forward repression by E(splbHLH/Hes shapes the response of late-responding genes. Based on these data, we propose a model in which Hes genes are responsible for co-ordinating the Notch response of a wide spectrum of other targets, explaining the critical functions these key regulators play in many developmental and disease contexts.

  5. A conserved role for Notch in priming the cellular response to Shh through ciliary localisation of the key Shh transducer, Smoothened

    DEFF Research Database (Denmark)

    Stasiulewicz, Magdalena; Gray, Shona; Mastromina, Ioanna;

    2015-01-01

    , we show 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 which acts mechanistically via regulation of ciliary localisation of key...

  6. Hydrogen Sulfide Prevents Synaptic Plasticity from VD-Induced Damage via Akt/GSK-3β Pathway and Notch Signaling Pathway in Rats.

    Science.gov (United States)

    Liu, Chunhua; Xu, Xiaxia; Gao, Jing; Zhang, Tao; Yang, Zhuo

    2016-08-01

    Our previous study has demonstrated that hydrogen sulfide (H2S) attenuates neuronal injury induced by vascular dementia (VD) in rats, but the mechanism is still poorly understood. In this study, we aimed to investigate whether the neuroprotection of H2S was associated with synaptic plasticity and try to interpret the potential underlying mechanisms. Adult male Wistar rats were suffered the ligation of bilateral common carotid arteries. At 24 h after surgery, rats were administered intraperitoneally with sodium hydrosulfide (NaHS, 5.6 mg·kg(-1)·day(-1)), a H2S donor, for 3 weeks in the VD+NaHS group and treated intraperitoneally with saline in the VD group respectively. Our results demonstrated that NaHS significantly decreased the level of glutamate. It obviously ameliorated cognitive flexibility as well as the spatial learning and memory abilities by Morris water maze. Moreover, NaHS significantly improved the long-term depression (LTD), and was able to elevate the expression of N-methyl-D-aspartate receptor subunit 2A, which plays a pivotal role in synaptic plasticity. Interestingly, NaHS decreased the phosphorylation of Akt, and it could maintain the activity of glycogen synthase kinase-3β (GSK-3β). Surprisingly, NaHS triggered the canonical Notch pathway by increasing expressions of Jagged-1 and Hes-1. These findings suggest that NaHS prevents synaptic plasticity from VD-induced damage partly via Akt/GSK-3β pathway and Notch signaling pathway.Hydrogen sulfide modulated the ratio of NMDAR 2A/2B and improved the synaptic plasticity via Akt/GSK-3β pathway and Notch signaling pathway in VD rats.

  7. Regulation of Monocarboxylic Acid Transporter 1 Trafficking by the Canonical Wnt/β-Catenin Pathway in Rat Brain Endothelial Cells Requires Cross-talk with Notch Signaling.

    Science.gov (United States)

    Liu, Zejian; Sneve, Mary; Haroldson, Thomas A; Smith, Jeffrey P; Drewes, Lester R

    2016-04-01

    The transport of monocarboxylate fuels such as lactate, pyruvate, and ketone bodies across brain endothelial cells is mediated by monocarboxylic acid transporter 1 (MCT1). Although the canonical Wnt/β-catenin pathway is required for rodent blood-brain barrier development and for the expression of associated nutrient transporters, the role of this pathway in the regulation of brain endothelial MCT1 is unknown. Here we report expression of nine members of the frizzled receptor family by the RBE4 rat brain endothelial cell line. Furthermore, activation of the canonical Wnt/β-catenin pathway in RBE4 cells via nuclear β-catenin signaling with LiCl does not alter brain endothelialMct1mRNA but increases the amount of MCT1 transporter protein. Plasma membrane biotinylation studies and confocal microscopic examination of mCherry-tagged MCT1 indicate that increased transporter results from reduced MCT1 trafficking from the plasma membrane via the endosomal/lysosomal pathway and is facilitated by decreased MCT1 ubiquitination following LiCl treatment. Inhibition of the Notch pathway by the γ-secretase inhibitorN-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycinet-butyl ester negated the up-regulation of MCT1 by LiCl, demonstrating a cross-talk between the canonical Wnt/β-catenin and Notch pathways. Our results are important because they show, for the first time, the regulation of MCT1 in cerebrovascular endothelial cells by the multifunctional canonical Wnt/β-catenin and Notch signaling pathways.

  8. Notch信号通路在神经精神领域的研究进展%Research progress on Notch signaling pathway in neuropsychiatry

    Institute of Scientific and Technical Information of China (English)

    雷蕾; 孙宁; 杜巧荣; 刘志芬; 杨春霞; 张克让

    2015-01-01

    Notch signal pathway is an evolutionarily conservative signal transduction system, which can regularly regulate cell proliferation, apoptosis, differentiation, apoptosis, adhesion, stem cell self-renewal, and organogenesis. In the central nervous system, Notch proteins express not only in embryonic stage, but also persist in the nervous system of adult animals, which can adjust and control the regulation of neural stem cell self-renewal and differentiation. Studies show that Notch signal pathway is closely related to neurological diseases and mental disorders, such as neurodevelopmental defects, cerebral ischemia injury, Alzheimer's disease, depression, schizophrenia, etc. This review introduceed the research progress on Notch signaling pathway in neuropsychiatry.%Notch 信号通路是一条进化上十分保守的信号转导系统,是少数能够反复调节细胞增殖和凋亡的信号转导系统,与细胞的增殖、分化、凋亡、黏附以及干细胞的自我更新有密切的联系。在中枢神经系统,Notch 蛋白不仅在胚胎阶段表达,并且持续存在于成年动物的神经系统中,调控了神经干细胞的自我更新和分化过程。研究显示 Notch 与神经发育缺陷、脑缺血损伤、阿尔茨海默病等神经系统疾病及抑郁症、精神分裂症等精神疾病密切相关。本文拟对 Notch 信号通路在神经精神领域的研究进展作一介绍。

  9. Progress in the study of Notch1 signaling pathway in breast cancer%Notch1信号通路在乳腺癌中的研究进展

    Institute of Scientific and Technical Information of China (English)

    金慧; 周晓倩; 郑淼; 李想; 刘俊

    2015-01-01

    乳腺癌是女性最常见、死亡率最高的恶性肿瘤之一,近年来其发病率不断升高.研究发现Notch1信号通路在乳腺癌中起着重要的作用.研究发现Notch1在正常乳腺组织和乳腺良性病变以及乳腺癌中均有表达,在乳腺浸润性导管癌中的表达率明显高于导管原位癌,其表达与乳腺癌HER-2亚型有关,在HER-2阳性型中的Notch1的阳性表达率明显高于其他亚型.研究认为Notch1阳性表达率高与其乳腺癌的分化程度低、分期晚、淋巴结转移阳性率高以及脑转移有关,预示着乳腺癌的预后差,并被认为可作为判断预后的临床指标.此外研究发现Notch1的高表达可导致乳腺癌对阿霉素与紫杉醇的耐药.研究发现 Notch1 高表达与乳腺癌侵袭强、凋亡抑制有关. 研究还发现Notch1 的表达影响乳腺癌干细胞的数量,是维持乳腺癌干细胞恶性表型的重要因子.且 Notch1 与VEGF、c-myc、CCL2、TRB3、MMP2等相关基因表达及肿瘤微环境相关.针对Notch1的靶向治疗的研究有Notch1单克隆抗体、三氧化二砷以及金雀异黄素等药物,以及Notch1相关通路的靶向治疗药物,均可抑制乳腺癌细胞的生长,对乳腺癌有抗肿瘤作用.%Breast cancer is one of the most common malignant tumors in women with the highest death rate. The incidence has been going up in these years. Studies have found that Notch1 signaling pathway plays an important role in breast cancer and is expressed in normal breast tissue and breast benign lesions as well as breast cancer, and the expression rate in breast invasive ductal carcinoma is significantly higher than that of ductal carcinomain situ. The expression of Notch1 in breast cancer is associated with breast cancer subtype HER-2 and the positive expression rate of Notch1 is significantly higher in HER-2 positive subtype than in other subtypes. Studies have suggested that high expression rate of Notch1 in breast cancer is associated with

  10. Methylseleninic acid sensitizes Notch3-activated OVCA429 ovarian cancer cells to carboplatin.

    Directory of Open Access Journals (Sweden)

    Tiffany J Tzeng

    Full Text Available Ovarian cancer, the deadliest of gynecologic cancers, is usually not diagnosed until advanced stages. Although carboplatin has been popular for treating ovarian cancer for decades, patients eventually develop resistance to this platinum-containing drug. Expression of neurogenic locus notch homolog 3 (Notch3 is associated with chemoresistance and poor overall survival in ovarian cancer patients. Overexpression of NICD3 (the constitutively active form of Notch3 in OVCA429 ovarian cancer cells (OVCA429/NICD3 renders them resistance to carboplatin treatment compared to OVCA429/pCEG cells expressing an empty vector. We have previously shown that methylseleninic acid (MSeA induces oxidative stress and activates ataxia-telangiectasia mutated and DNA-dependent protein kinase in cancer cells. Here we tested the hypothesis that MSeA and carboplatin exerted a synthetic lethal effect on OVCA429/NICD3 cells. Co-treatment with MSeA synergistically sensitized OVCA429/NICD3 but not OVCA429/pCEG cells to the killing by carboplatin. This synergism was associated with a cell cycle exit at the G2/M phase and the induction of NICD3 target gene HES1. Treatment of N-acetyl cysteine or inhibitors of the above two kinases did not directly impact on the synergism in OVCA429/NICD3 cells. Taken together, these results suggest that the efficacy of carboplatin in the treatment of high grade ovarian carcinoma can be enhanced by a combinational therapy with MSeA.

  11. Oncogenic role of the Notch pathway in primary liver cancer

    Science.gov (United States)

    LU, JIE; XIA, YUJING; CHEN, KAN; ZHENG, YUANYUAN; WANG, JIANRONG; LU, WENXIA; YIN, QIN; WANG, FAN; ZHOU, YINGQUN; GUO, CHUANYONG

    2016-01-01

    Primary liver cancer, which includes hepatocellular carcinoma (HCC), intrahepatic cholangiocarcinoma (ICC) and fibrolamellar HCC, is one of the most common malignancies and the third leading cause of cancer-associated mortality, worldwide. Despite the development of novel therapies, the prognosis of liver cancer patients remains extremely poor. Thus, investigation of the genetic background and molecular mechanisms underlying the development and progression of this disease has gained significant attention. The Notch signaling pathway is a crucial determinant of cell fate during development and disease in several organs. In the liver, Notch signaling is involved in biliary tree development and tubulogenesis, and is also significant in the development of HCC and ICC. These findings suggest that the modulation of Notch pathway activity may have therapeutic relevance. The present review summarizes Notch signaling during HCC and ICC development and discusses the findings of recent studies regarding Notch expression, which reveal novel insights into its function in liver cancer progression. PMID:27347091

  12. Arsenic Trioxide Inhibits Cell Growth and Induces Apoptosis through Inactivation of Notch Signaling Pathway in Breast Cancer

    Directory of Open Access Journals (Sweden)

    Zhiwei Wang

    2012-08-01

    Full Text Available Arsenic trioxide has been reported to inhibit cell growth and induce apoptotic cell death in many human cancer cells including breast cancer. However, the precise molecular mechanisms underlying the anti-tumor activity of arsenic trioxide are still largely unknown. In the present study, we assessed the effects of arsenic trioxide on cell viability and apoptosis in breast cancer cells. For mechanistic studies, we used multiple cellular and molecular approaches such as MTT assay, apoptosis ELISA assay, gene transfection, RT-PCR, Western blotting, and invasion assays. For the first time, we found a significant reduction in cell viability in arsenic trioxide-treated cells in a dose-dependent manner, which was consistent with induction of apoptosis and also associated with down-regulation of Notch-1 and its target genes. Taken together, our findings provide evidence showing that the down-regulation of Notch-1 by arsenic trioxide could be an effective approach, to cause down-regulation of Bcl-2, and NF-κB, resulting in the inhibition of cell growth and invasion as well as induction of apoptosis. These results suggest that the anti-tumor activity of arsenic trioxide is in part mediated through a novel mechanism involving inactivation of Notch-1 and its target genes. We also suggest that arsenic trioxide could be further developed as a potential therapeutic agent for the treatment of breast cancer.

  13. Invagination centers within the Drosophila stomatogastric nervous system anlage are positioned by Notch-mediated signaling which is spatially controlled through wingless.

    Science.gov (United States)

    González-Gaitán, M; Jäckle, H

    1995-08-01

    The gut-innervating stomatogastric nervous system of Drosophila, unlike the central and the peripheral nervous system, derives from a compact, single layered epithelial anlage. Here we report how this anlage is initially defined during embryogenesis by the expression of proneural genes of the achaete-scute complex in response to the maternal terminal pattern forming system. Within the stomatogastric nervous system anlage, the wingless-dependent intercellular communication system adjusts the cellular range of Notch-dependent lateral inhibition to single-out three achaete-expressing cells. Those cells define distinct invagination centers which orchestrate the behavior of neighboring cells to form epithelial infoldings, each headed by an achaete-expressing tip cell. Our results suggest that the wingless pathway acts not as an instructive signal, but as a permissive factor which coordinates the spatial activity of morphoregulatory signals within the stomatogastric nervous system anlage.

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

    Science.gov (United States)

    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. PMID:23190077

  15. SOX1 links the function of neural patterning and Notch signalling in the ventral spinal cord during the neuron-glial fate switch

    Energy Technology Data Exchange (ETDEWEB)

    Genethliou, Nicholas; Panayiotou, Elena [The Cyprus Institute of Neurology and Genetics, Airport Avenue, No. 6, Agios Dometios, 2370 Nicosia (Cyprus); Department of Biological Sciences, University of Cyprus, P.O. Box 20537, 1678 Nicosia (Cyprus); Panayi, Helen; Orford, Michael; Mean, Richard; Lapathitis, George; Gill, Herman; Raoof, Sahir [The Cyprus Institute of Neurology and Genetics, Airport Avenue, No. 6, Agios Dometios, 2370 Nicosia (Cyprus); Gasperi, Rita De; Elder, Gregory [James J. Peters VA Medical Center, Research and Development (3F22), 130 West Kingsbridge Road, Bronx, NY 10468 (United States); Kessaris, Nicoletta; Richardson, William D. [Wolfson Institute for Biomedical Research and Research Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT (United Kingdom); Malas, Stavros, E-mail: smalas@cing.ac.cy [The Cyprus Institute of Neurology and Genetics, Airport Avenue, No. 6, Agios Dometios, 2370 Nicosia (Cyprus); Department of Biological Sciences, University of Cyprus, P.O. Box 20537, 1678 Nicosia (Cyprus)

    2009-12-25

    During neural development the transition from neurogenesis to gliogenesis, known as the neuron-glial ({Nu}/G) fate switch, requires the coordinated function of patterning factors, pro-glial factors and Notch signalling. How this process is coordinated in the embryonic spinal cord is poorly understood. Here, we demonstrate that during the N/G fate switch in the ventral spinal cord (vSC) SOX1 links the function of neural patterning and Notch signalling. We show that, SOX1 expression in the vSC is regulated by PAX6, NKX2.2 and Notch signalling in a domain-specific manner. We further show that SOX1 regulates the expression of Hes1 and that loss of Sox1 leads to enhanced production of oligodendrocyte precursors from the pMN. Finally, we show that Notch signalling functions upstream of SOX1 during this fate switch and is independently required for the acquisition of the glial fate perse by regulating Nuclear Factor I A expression in a PAX6/SOX1/HES1/HES5-independent manner. These data integrate functional roles of neural patterning factors, Notch signalling and SOX1 during gliogenesis.

  16. Notch and TGFβ form a positive regulatory loop and regulate EMT in epithelial ovarian cancer cells.

    Science.gov (United States)

    Zhou, Jiesi; Jain, Saket; Azad, Abul K; Xu, Xia; Yu, Hai Chuan; Xu, Zhihua; Godbout, Roseline; Fu, YangXin

    2016-08-01

    Epithelial-mesenchymal transition (EMT) plays a critical role in the progression of epithelial ovarian cancer (EOC). However, the mechanisms that regulate EMT in EOC are not fully understood. Here, we report that activation of Notch1 induces EMT in EOC cells as evidenced by downregulation of E-cadherin and cytokeratins, upregulation of Slug and Snail, as well as morphological changes. Interestingly, activation of Notch1 increases TGFβ/Smad signaling by upregulating the expression of TGFβ and TGFβ type 1 receptor. Time course experiments demonstrate that inhibition of Notch by DAPT (a γ-secretase inhibitor) decreases TGFβ-induced phosphorylation of receptor Smads at late, but not at early, timepoints. These results suggest that Notch activation plays a role in sustaining TGFβ/Smad signaling in EOC cells. Furthermore, inhibition of Notch by DAPT decreases TGFβ induction of Slug and repression of E-cadherin and knockdown of Notch1 decreases TGFβ-induced repression of E-cadherin, indicating that Notch is required, at least in part, for TGFβ-induced EMT in EOC cells. On the other hand, TGFβ treatment increases the expression of Notch ligand Jagged1 and Notch target gene HES1 in EOC cells. Functionally, the combination of Notch1 activation and TGFβ treatment is more potent in promoting motility and migration of EOC cells than either stimulation alone. Taken together, our results indicate that Notch and TGFβ form a reciprocal positive regulatory loop and cooperatively regulate EMT and promote EOC cell motility and migration. PMID:27075926

  17. RBPJ, the major transcriptional effector of Notch signaling, remains associated with chromatin throughout mitosis, suggesting a role in mitotic bookmarking.

    Directory of Open Access Journals (Sweden)

    Robert J Lake

    2014-03-01

    Full Text Available Mechanisms that maintain transcriptional memory through cell division are important to maintain cell identity, and sequence-specific transcription factors that remain associated with mitotic chromatin are emerging as key players in transcriptional memory propagation. Here, we show that the major transcriptional effector of Notch signaling, RBPJ, is retained on mitotic chromatin, and that this mitotic chromatin association is mediated through the direct association of RBPJ with DNA. We further demonstrate that RBPJ binds directly to nucleosomal DNA in vitro, with a preference for sites close to the entry/exit position of the nucleosomal DNA. Genome-wide analysis in the murine embryonal-carcinoma cell line F9 revealed that roughly 60% of the sites occupied by RBPJ in asynchronous cells were also occupied in mitotic cells. Among them, we found that a fraction of RBPJ occupancy sites shifted between interphase and mitosis, suggesting that RBPJ can be retained on mitotic chromatin by sliding on DNA rather than disengaging from chromatin during mitotic chromatin condensation. We propose that RBPJ can function as a mitotic bookmark, marking genes for efficient transcriptional activation or repression upon mitotic exit. Strikingly, we found that sites of RBPJ occupancy were enriched for CTCF-binding motifs in addition to RBPJ-binding motifs, and that RBPJ and CTCF interact. Given that CTCF regulates transcription and bridges long-range chromatin interactions, our results raise the intriguing hypothesis that by collaborating with CTCF, RBPJ may participate in establishing chromatin domains and/or long-range chromatin interactions that could be propagated through cell division to maintain gene expression programs.

  18. Roles of notch signaling in rotenone-induced apoptosis of PC12 cells%Notch信号通路在鱼藤酮诱导的PC12细胞凋亡中的作用

    Institute of Scientific and Technical Information of China (English)

    张媚; 何亮; 李俊; 张临洪

    2012-01-01

    Objective To elucidate the roles of Notch Signaling in rotenone-induced apoptosis of PC12 cells.Methods PC12 ceils were treated with rotenone (5 μmol/L).Apoptosis of PC12 cells and activation of Notch signaling were observed.PC12 cells were pretreated with N-[N-(3,5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butvlester ( DAPT,10 μmol/L) before incubation with rotenone.The effect of Notch signaling on apoptosis of PC12 cells in response to rotenone was evaluated and the relationship between Notch signaling and rotenone-induced apoptosis of PC12 cells was analyzed.Results Rotenone significantly induced apoptosis of PC12 cells [( 35.6 ± 5.4 ) %,P < 0.05] and increased Caspase-3 activity (0.52 ±0.15,P <0.05 ).At the same time,rotenone activated Notch/Jagged1 signaling in PC12 cells.However,inhibition of Notch signaling by DAPT not only decreased apoptosis of PC12 cells [(9.8 ±3.1 ) %,P < 0.05],but also diminished Caspase-3 activity (0.16 ± 0.06,P < 0.05 ).Conclusion Activation of Notch signaling could be one of the main mechanisms for rotenone-induced apoptosis of PC12 cells.%目的 探讨Notch信号通路在鱼藤酮诱导PC12细胞凋亡中的作用机制.方法 用鱼藤酮(5 μmol/L)处理PC12细胞,检测PC12细胞的凋亡和Notch信号通路的活化状态.同时以Notch信号抑制剂(2S)-N-N-(3,5-二氟苯乙酰基)-L-丙氨酰-2-苯基甘氨酸叔丁酯(DAPT,10 μmol/L)处理上述PC12细胞,观察Notch信号通路抑制后PC12细胞对鱼藤酮处理的凋亡反应,分析Notch信号通路与鱼藤酮诱导PC12细胞凋亡之间的关系.结果 鱼藤酮显著诱导PC12细胞凋亡[(35.6±5.4)%,P<0.05]和半胱氨酰天冬氨酸特异性蛋白酶-3(Caspase-3)活性升高(0.52±0.15,P<0.05),并活化其Notch/Jagged1信号通路.DAPT显著抑制鱼藤酮诱导的Notch/Jagged1信号通路活化并降低PC12细胞凋亡率[(9.8±3.1)%,P<0.05]和Caspase-3活性(0.16 ±0.06,P<0.05).结论 Notch信号通

  19. The Effect of Physiological Stimuli on Sarcopenia; Impact of Notch and Wnt Signaling on Impaired Aged Skeletal Muscle Repair

    Directory of Open Access Journals (Sweden)

    Susan Tsivitse Arthur, Ian D. Cooley

    2012-01-01

    Full Text Available The age-related loss of skeletal muscle mass and function that is associated with sarcopenia can result in ultimate consequences such as decreased quality of life. The causes of sarcopenia are multifactorial and include environmental and biological factors. The purpose of this review is to synthesize what the literature reveals in regards to the cellular regulation of sarcopenia, including impaired muscle regenerative capacity in the aged, and to discuss if physiological stimuli have the potential to slow the loss of myogenic potential that is associated with sarcopenia. In addition, this review article will discuss the effect of aging on Notch and Wnt signaling, and whether physiological stimuli have the ability to restore Notch and Wnt signaling resulting in rejuvenated aged muscle repair. The intention of this summary is to bring awareness to the benefits of consistent physiological stimulus (exercise to combating sarcopenia as well as proclaiming the usefulness of contraction-induced injury models to studying the effects of local and systemic influences on aged myogenic capability.

  20. In vitro modeling of endothelial interaction with macrophages and pericytes demonstrates Notch signaling function in the vascular microenvironment.

    Science.gov (United States)

    Tattersall, Ian W; Du, Jing; Cong, Zhuangzhuang; Cho, Bennet S; Klein, Alyssa M; Dieck, Chelsea L; Chaudhri, Reyhaan A; Cuervo, Henar; Herts, James H; Kitajewski, Jan

    2016-04-01

    Angiogenesis is regulated by complex interactions between endothelial cells and support cells of the vascular microenvironment, such as tissue myeloid cells and vascular mural cells. Multicellular interactions during angiogenesis are difficult to study in animals and challenging in a reductive setting. We incorporated stromal cells into an established bead-based capillary sprouting assay to develop assays that faithfully reproduce major steps of vessel sprouting and maturation. We observed that macrophages enhance angiogenesis, increasing the number and length of endothelial sprouts, a property we have dubbed "angiotrophism." We found that polarizing macrophages toward a pro-inflammatory profile further increased their angiotrophic stimulation of vessel sprouting, and this increase was dependent on macrophage Notch signaling. To study endothelial/pericyte interactions, we added vascular pericytes directly to the bead-bound endothelial monolayer. These pericytes formed close associations with the endothelial sprouts, causing increased sprout number and vessel caliber. We found that Jagged1 expression and Notch signaling are essential for the growth of both endothelial cells and pericytes and may function in their interaction. We observed that combining endothelial cells with both macrophages and pericytes in the same sprouting assay has multiplicative effects on sprouting. These results significantly improve bead-capillary sprouting assays and provide an enhanced method for modeling interactions between the endothelium and the vascular microenvironment. Achieving this in a reductive in vitro setting represents a significant step toward a better understanding of the cellular elements that contribute to the formation of mature vasculature.

  1. Adaptive Notch filter based active damping for power converters using LCL filters

    DEFF Research Database (Denmark)

    Ciobotaru, M.; Rossé, A.; Bede, L.;

    2016-01-01

    This paper proposes an active damping technique for grid-connected converters using inductor-capacitor-inductor (LCL) filters. The technique relies on a discrete-time adaptive notch filter (NF) which is able to adapt its resonance frequency and bandwidth in real-time. The tuning function of this ...... of the discrete-time implementation of such filter due to the proximity to Nyquist-Shannon limit. A detailed analysis of the filter and the control system is also included. The experimental results validate the effectiveness of the proposed technique....

  2. Neuronal apoptosis and synaptic density in the dentate gyrus of ischemic rats' response to chronic mild stress and the effects of Notch signaling.

    Directory of Open Access Journals (Sweden)

    Shaohua Wang

    Full Text Available Our previous research highlighted an inconsistency with Notch1 signaling-related compensatory neurogenesis after chronic mild stress (CMS in rodents suffering from cerebral ischemia, which continue to display post-stroke depressive symptoms. Here, we hypothesize that CMS aggrandized ischemia-related apoptosis injury and worsened synaptic integrity via gamma secretase-meditated Notch1 signaling. Adult rats were exposed to a CMS paradigm after left middle cerebral artery occlusion (MCAO. Open-field and sucrose consumption testing were employed to assess depression-like behavior. Gene expression of pro-apoptotic Bax, anti-apoptotic Bcl-2, and synaptic density-related synaptophysin were measured by western blotting and real-time PCR on Day 28 after MCAO surgery. CMS induced depressive behaviors in ischemic rats, which was accompanied by an elevation in Bax/bcl-2 ratio, TUNEL staining in neurons and reduced synaptophysin expression in the dentate gyrus. These collective effects were reversed by the gamma-secretase inhibitor DAPT (N-[N-(3,5-difluorophenacetyl-L-alanyl]-S-phenyl-glycine t-butyl ester. We found that post-stroke stressors made neurons in the dentate gyrus vulnerable to apoptosis, which supports a putative role for Notch signaling in neural integrity, potentially in newborn cells' synaptic deficit with regard to preexisting cells. These findings suggest that post-stroke depression therapeutically benefits from blocking gamma secretase mediated Notch signaling, and whether this signaling pathway could be a therapeutic target needs to be further investigated.

  3. Mind bomb-1 in dendritic cells is specifically required for Notch-mediated T helper type 2 differentiation.

    Directory of Open Access Journals (Sweden)

    Hyun-Woo Jeong

    Full Text Available In dendritic cell (DC-CD4(+ T cell interaction, Notch signaling has been implicated in the CD4(+ T cell activation, proliferation, and subset differentiation. However, there has been a lot of debate on the exact role of Notch signaling. Here, we observed that expression of Mind bomb-1 (Mib1, a critical regulator of Notch ligands for the activation of Notch signaling, increases gradually as precursor cells differentiate into DCs in mice. To clarify the role of Mib1 in DC-CD4(+ T cell interactions, we generated Mib1-null bone marrow-derived DCs. These cells readily expressed Notch ligands but failed to initiate Notch activation in the adjacent cells. Nevertheless, Mib1-null DCs were able to prime the activation and proliferation of CD4(+ T cells, suggesting that Notch activation in CD4(+ T cells is not required for these processes. Intriguingly, stimulation of CD4(+ T cells with Mib1-null DCs resulted in dramatically diminished Th2 cell populations, while preserving Th1 cell populations, both in vitro and in vivo. Our results demonstrate that Mib1 in DCs is critical for the activation of Notch signaling in CD4(+ T cells, and Notch signaling reinforces Th2 differentiation, but is not required for the activation or proliferation of the CD4(+ T cells.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

  6. Notch4 is activated in endothelial and smooth muscle cells in human brain arteriovenous malformations

    OpenAIRE

    ZhuGe, Qichuan; Wu, Zhebao; Huang, Lijie; Zhao, Bei; Zhong, Ming; Zheng, Weiming; GouRong, Chen; Mao, XiaoOu; XIE, Lin; Wang, Xiangdong; Jin, Kunlin

    2013-01-01

    Up-regulation of Notch4 was observed in the endothelial cells in the arteriovenous malformations (AVMs) in mice. However, whether Notch4 is also involved in brain AVMs in humans remains unclear. Here, we performed immunohistochemistry on normal brain vascular tissue and surgically resected brain AVMs and found that Notch4 was up-regulated in the subset of abnormal vessels of the brain AVM nidus, compared with control brain vascular tissue. Two-photon confocal images show that Notch4 was expre...

  7. Notch 信号通路与白血病干细胞的关系及研究进展%Progress on the relationship between Notch signaling pathway and leukemia stem cells

    Institute of Scientific and Technical Information of China (English)

    胡彬; 付伟; 梁英民

    2015-01-01

    Human leukemia is considered clonal hematological malignancies initiated by chromosomal aberrations or epigenetic alterations occurring at the level of either pluripotent hematopoietic stem cells(HSCs)or early multipotent progenitors(MPPs). Human leukemia ranked top ten in malignancy tumor and mortality is high,mostly occurs in children and adolescents. Currently,mainly in the treatment of leukemia is chemotherapy,and with development of new drugs and hematopoietic stem cell transplantation,leukemia remission rate has been improved than before,but relapse after drug discontinuation and treatment become a puzzle problem. Currently Notch gene has become recognized as one of oncogenes associated with leukemia,so the Notch gene targeting studies may give us new treatments. This minire-view focuses on review the relationship between Notch signaling pathway and leukemic stem cells and therapeutic advance.%白血病是造血干细胞恶性克隆疾病,多是由染色体畸变诱发,使得造血干细胞( hematopoietic stem cells,HSCs)或更早期的多能祖细胞(multipotent progenitors,MPPs)遗传学发生改变。白血病在恶性肿瘤发病率排名前十位,死亡率高,且多发生在儿童及青年。目前白血病的治疗主要以化疗为主,随着新药的研发和造血干细胞的移植,白血病的缓解率较先前有所提高,但耐药和停药后复发成为治疗的一个难题。目前Notch 已经成为公认的与白血病有关的癌基因之一,所以,以 Notch 为靶向治疗研究可能会给我们提供新的治疗方法。本文重点就 Notch 与白血病干细胞的关系及治疗进展作一综述。

  8. Interactions between enhancer of rudimentary and Notch and deltex reveal a regulatory function of enhancer of rudimentary in the Notch signaling pathway in Drosophila melanogaster

    OpenAIRE

    Tsubota, Stuart I.; Vogel, Alecia C.; Phillips, Anthony C; Ibach, Suzanne M; Weber, Nicholas K; Kostrzebski, Melissa A; Spencer, Susan A

    2011-01-01

    Enhancer of rudimentary, e(r), encodes a small nuclear protein, ER, that has been implicated in the regulation of pyrimidine metabolism, DNA replication and cell proliferation. In Drosophila melanogaster, a new recessive Notch allele, Nnd-p, was isolated as a lethal in combination with an e(r) allele, e(r)p2. Both mutants are viable as single mutants. Nnd-p is caused by a P-element insertion in the 5′ UTR, 378-bp upstream of the start of translation. Together the molecular and genetic data ar...

  9. Notch-Mediated Cell Adhesion

    OpenAIRE

    Akihiko Murata; Shin-Ichi Hayashi

    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...

  10. Clinical significance of NOTCH1 and NOTCH2 expression in gastric carcinomas: an immunohistochemical study

    Directory of Open Access Journals (Sweden)

    Lukas eBauer

    2015-04-01

    Full Text Available Background: Notch signaling can exert oncogenic or tumor suppressive functions and can contribute to chemotherapy resistance in cancer. In this study, we aimed to clarify the clinicopathological significance and the prognostic and predictive value of NOTCH1 and NOTCH2 expression in gastric carcinoma (GC. Methods: NOTCH1 and NOTCH2 expression was determined immunohistochemically in 142 primarily resected GCs using tissue microarrays and in 84 pretherapeutic biopsies from patients treated by neoadjuvant chemotherapy. The results were correlated with survival, response to therapy and clinico-pathological features.Results: Primarily resected patients with NOTCH1-negative tumors demonstrated worse survival. High NOTCH1 expression was associated with early-stage tumors and with significantly increased survival in this subgroup.Higher NOTCH2 expression was associated with early-stage and intestinal-type tumors and with better survival in the subgroup of intestinal-type tumors.In pretherapeutic biopsies, higher NOTCH1 and NOTCH2 expression was more frequent in nonresponding patients, but these differences were statistically not significant. Conclusion: Our findings suggested that, in particular NOTCH1 expression indicated good prognosis in GC. The close relationship of high NOTCH1 and NOTCH2 expression with early tumor stages may indicate a tumor-suppressive role of Notch signaling in GC. The role of NOTCH1 and NOTCH2 in neoadjuvantly treated GC is limited.

  11. SNX17 regulates Notch pathway and pancreas development through the retromer-dependent recycling of Jag1

    Directory of Open Access Journals (Sweden)

    Yin Wenguang

    2012-06-01

    Full Text Available Abstract Background Notch is one of the most important signaling pathways involved in cell fate determination. Activation of the Notch pathway requires the binding of a membrane-bound ligand to the Notch receptor in the adjacent cell which induces proteolytic cleavages and the activation of the receptor. A unique feature of the Notch signaling is that processes such as modification, endocytosis or recycling of the ligand have been reported to play critical roles during Notch signaling, however, the underlying molecular mechanism appears context-dependent and often controversial. Results Here we identified SNX17 as a novel regulator of the Notch pathway. SNX17 is a sorting nexin family protein implicated in vesicular trafficking and we find it is specifically required in the ligand-expressing cells for Notch signaling. Mechanistically, SNX17 regulates the protein level of Jag1a on plasma membrane by binding to Jag1a and facilitating the retromer-dependent recycling of the ligand. In zebrafish, inhibition of this SNX17-mediated Notch signaling pathway results in defects in neurogenesis as well as pancreas development. Conclusions Our results reveal that SNX17, by acting as a cargo-specific adaptor, promotes the retromer dependent recycling of Jag1a and Notch signaling and this pathway is involved in cell fate determination during zebrafish neurogenesis and pancreas development.

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

    Directory of Open Access Journals (Sweden)

    Andrew T Baker

    2014-12-01

    Full Text Available 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 (MAPK and Phosphatidylinositol 3-Kinase (PI3K, thereby allowing cancer cells to survive molecular targeted therapies, undergo EMT, 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.

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

    Science.gov (United States)

    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

  14. DAPT抑制妊娠滋养细胞肿瘤Notch信号通路对细胞增殖和EMT影响的研究%A study on the role of notch signaling pathway in gestational trophoblastic tumor.

    Institute of Scientific and Technical Information of China (English)

    周园园; 薛艳; 田泉; 安瑞芳

    2015-01-01

    Objective:To study the significance of Notch signaling pathway in the de-velopment of gestational trophoblastic tumor and the relationship between EMT. Methods:The choriocarcinoma cell lines JAR and JEG-3 were treated with gamma-secretase inhibitor ( DAPT) . Using MTT assay to examine the activity of the two cell lines and evaluate the infulu-ence on the proliferation in JAR and JEG-3 cells of DAPT. qPCR was performed to assess mR-NA expression of Notch1. In addition,EMT related protein E-cadherin was detected by Western blot. Results:DAPT could inhibit JEG-3 cells and JAR cells growth,down-regulate the expres-sion of Notch1 mRNA,and up-regulate the expression of E-cadherin in JAR cells. Conclusions:Notch sigaling pathway and EMT may be associated with the development of gestational tropho-blastic tumor. DAPT may be a potential target of new therapeutic investigation in gestational trophoblastic tumor.%目的:探讨Notch信号通路在人妊娠滋养细胞肿瘤发生发展过程中的重要作用,及其与EMT之间的关系. 方法:采用γ-分泌酶抑制剂DAPT处理JAR和JEG-3两种人绒毛膜癌细胞株,MTT法检测两种细胞株的增殖情况,qPCR法检测Notch1 mRNA表达. Western blot法检测DAPT阻断Notch信号通路后JAR细胞中EMT相关蛋白E-cad的表达情况. 结果:DAPT能抑制JEG-3、JAR细胞生长,10μmol/L和15μmol/L DAPT作用48 h开始分别抑制JEG-3和JAR细胞生长( P0. 05);JAR细胞中,10μmol/L和15μmol/L DAPT作用组中Notch1 mRNA表达下调,两组比较差异有统计学意义( P<0 . 05 ). DAPT能上调JAR细胞中E-cad表达. 结论:Notch信号通路和EMT与妊娠滋养细胞肿瘤的发生发展有关;γ-分泌酶抑制剂DAPT或可成为妊娠滋养细胞肿瘤治疗的一个新靶点.

  15. Common activation of canonical Wnt signaling in pancreatic adenocarcinoma.

    Directory of Open Access Journals (Sweden)

    Marina Pasca di Magliano

    Full Text Available Pancreatic ductal adenocarcinoma (PDA is an extremely aggressive malignancy, which carries a dismal prognosis. Activating mutations of the Kras gene are common to the vast majority of human PDA. In addition, recent studies have demonstrated that embryonic signaling pathway such as Hedgehog and Notch are inappropriately upregulated in this disease. The role of another embryonic signaling pathway, namely the canonical Wnt cascade, is still controversial. Here, we use gene array analysis as a platform to demonstrate general activation of the canonical arm of the Wnt pathway in human PDA. Furthermore, we provide evidence for Wnt activation in mouse models of pancreatic cancer. Our results also indicate that Wnt signaling might be activated downstream of Hedgehog signaling, which is an early event in PDA evolution. Wnt inhibition blocked proliferation and induced apoptosis of cultured adenocarcinoma cells, thereby providing evidence to support the development of novel therapeutical strategies for Wnt inhibition in pancreatic adenocarcinoma.

  16. Genistein down-regulates Notch-1 expression and inactivates Hedgehog signaling pathway in pancreatic cancer cells%三羟异黄酮抑制胰腺癌细胞Notch-1和Hedgehog信号通路活性

    Institute of Scientific and Technical Information of China (English)

    廖宇圣; 范学科; 覃华; 张翠芳; 陈芬; 高慧涛; 赵秋

    2008-01-01

    Objective To investigate the effect of genistein on Notch-1, SHH and HHIP gene expression and on the cell cycle and proliferation of of BxPC3 cells. Methods Human pancreatic cancer cell line BxPC3 was cultured. The BxPC3 cells were treated with genistein and then the total RNA and protein were extracted. RT-PCR was used to detect the expression of Notch-1 mRNA, SHH mRNA and HHIP mRNA. Noteh-1 and SHH protein was determined by western blotting. MTT assay was used to detect proliferation of BxPC3 cells. The cell cycle of BxPC3 cells was measured by Propidium iodide (PI) and flow cytometry. Results The inhibiting rate was 67.17%±2.32% when BxPC3 cell lines were treated by 20μg/ml genistein for 48 hours. Notch-1 mRNA was down-regulated from 2.454±0.068 to 1.304±O.169 ; SHH mRNA was down-regulated from 0.959±0.023 to O.472±0.077 ; HHIP mRNA was up-regulated from 0.625±O.158 to 1.761±0.121. Notch-1 protein expression was down-regulated from 1.361±0.109 to 0.760±0.114; SHH protein expression was down-regulated from 0.265±0.018 to 0.129±0.013. (52.77±9.47)% cells were hindered in G2/M stage. Conclusions Genistein could down-regulate Notch-1 expression and inactivate Hedgehog signaling pathway and inhibit the proliferation of pancreatic cancer cells.%目的 探讨三羟异黄酮对胰腺癌BxPC3细胞Notch-1和Hedgehog信号通路分子SHH和HHIP表达以及对细胞周期和增殖的影响.方法 体外培养胰腺癌BxPC3细胞,三羟异黄酮作用BxPC3细胞后,提取总RNA和蛋白质.RT-PCR方法检测Notch-1 mNRA、SHH mRNA和HHIP mRNA表达,Western blotting方法检测Notch-1和SHH蛋白的表达.MTT方法检测BxPC3细胞的增值,流式细胞术和PI单染法分析细胞的周期.结果 20μg/ml的三羟异黄酮处理BxPC3 48 h后,细胞增殖抑制率为(67.17±2.32)%.Notch-1 mRNA表达从2.454±0.068下调到1.304±0.169;SHH mRNA表达从0.959±0.023下调到0.472±0.077;而HHIP mRNA表达从0.625±0.158增加到1.761±0.121.Notch-1蛋白表达从1

  17. The altered change of Notch1 signaling in depressed rats%抑郁状态下大鼠海马Notch1信号系统的改变

    Institute of Scientific and Technical Information of China (English)

    李元; 戴志萍; 隋毓秀

    2011-01-01

    目的 了解大鼠抑郁模型中海马神经重塑障碍与Notch1信号系统功能改变的关系.方法 54只大鼠随机分为CUMS 14 d组、CUMS 28 d组和对照组,前两组接受慢性不可预知温和应激和孤养(chronic unpredictable mild stress,CUMS)14 d和28 d建立抑郁模型.采用免疫组化、免疫荧光、RT-PCR和Western blot 法.测定大鼠海马神经干细胞的增殖、存活和分化以及Notch1信号通路各个因子的基因及蛋白表达水平的改变.结果 与对照组比较,CUMS 14 d组和CUMS 28 d组大鼠海马神经干细胞增殖与存活明显减少(P0.05).与对照组比较.CUMS 14 d组和CUMS 28 d组Notch1信号通路各因子(NICD、Hes1、Hes5和Jag1)基因表达和蛋白水平明显降低(P<0.01).结论 抑郁大鼠海马齿状回神经干细胞增殖和存活受到抑制,但分化无改变;同时,大鼠海马Notch1功能下调.提示Notch1信号系统可能与抑郁症海马神经再生障碍有关.%Objective To investigate the relationship between impaired hippocampal neurogenesis and altered Notchl signaling in depressed rats. Methods In the present study, chronic unpredictable mild stress (CUMS) was used to inhibit the neurogenesis in the hippocampus. The function of Notchl signaling was investigated by using realtime PCR and western blot at different time points (14 d and 28 d) during chronic stress. The hippocampal neurogenesis was monitored by assessing cell proliferation, survival, and differentiation. Results After 14 days, CUMS significantly reduced weight (P < 0.05), the sucrose preference (P < 0.001), number of squares crossed (P < 0.01) and number of grooming and rearing compared with the controls. The immobility time was significantly increased after 14 d CUMS treated relative to the controls (P < 0.001). Twenty-eight days after CUMS protocol, these parameters were significantly difference in rats exposed to CUMS compare with the controls (weight, P < 0.05; sucrose preference, P < 0.001; number of

  18. A functional study of EGFR and Notch signaling in brain cancer stem-like cells from glioblastoma multiforme (Ph.d.)

    DEFF Research Database (Denmark)

    Kristoffersen, Karina

    2013-01-01

    throughout this thesis project, we suggest that targeting a bCSC population by EGFR and/or Notch inhibition is feasible and future studies might prove if anti-bCSC therapy in combination with conventional therapy can improve the prognosis for GBM patients displaying a specific gene expression profile...... on their resemblance to normal neural stem cells (NSC) and their tumorigenic potential. Like for NSC, the epidermal growth factor receptor (EGFR) and Notch receptor signaling pathways are believed to be important for the maintenance of bCSC. These pathways as such present promising targets in a future anti-bCSC GBM...... for new molecular and cellular targets that can improve the prognosis for GBM patients. One such target is the brain cancer stem-like cells (bCSC) that are believed to be responsible for tumor initiation, progression, treatment resistance and ultimately relapse. bCSC are identified based...

  19. Tissue regeneration and biomineralization in sea urchins: role of Notch signaling and presence of stem cell markers.

    Science.gov (United States)

    Reinardy, Helena C; Emerson, Chloe E; Manley, Jason M; Bodnar, Andrea G

    2015-01-01

    Echinoderms represent a phylum with exceptional regenerative capabilities that can reconstruct both external appendages and internal organs. Mechanistic understanding of the cellular pathways involved in regeneration in these animals has been hampered by the limited genomic tools and limited ability to manipulate regenerative processes. We present a functional assay to investigate mechanisms of tissue regeneration and biomineralization by measuring the regrowth of amputated tube feet (sensory and motor appendages) and spines in the sea urchin, Lytechinus variegatus. The ability to manipulate regeneration was demonstrated by concentration-dependent inhibition of regrowth of spines and tube feet by treatment with the mitotic inhibitor, vincristine. Treatment with the gamma-secretase inhibitor DAPT resulted in a concentration-dependent inhibition of regrowth, indicating that both tube feet and spine regeneration require functional Notch signaling. Stem cell markers (Piwi and Vasa) were expressed in tube feet and spine tissue, and Vasa-positive cells were localized throughout the epidermis of tube feet by immunohistochemistry, suggesting the existence of multipotent progenitor cells in these highly regenerative appendages. The presence of Vasa protein in other somatic tissues (e.g. esophagus, radial nerve, and a sub-population of coelomocytes) suggests that multipotent cells are present throughout adult sea urchins and may contribute to normal homeostasis in addition to regeneration. Mechanistic insight into the cellular pathways governing the tremendous regenerative capacity of echinoderms may reveal processes that can be modulated for regenerative therapies, shed light on the evolution of regeneration, and enable the ability to predict how these processes will respond to changing environmental conditions.

  20. Tissue regeneration and biomineralization in sea urchins: role of Notch signaling and presence of stem cell markers.

    Directory of Open Access Journals (Sweden)

    Helena C Reinardy

    Full Text Available Echinoderms represent a phylum with exceptional regenerative capabilities that can reconstruct both external appendages and internal organs. Mechanistic understanding of the cellular pathways involved in regeneration in these animals has been hampered by the limited genomic tools and limited ability to manipulate regenerative processes. We present a functional assay to investigate mechanisms of tissue regeneration and biomineralization by measuring the regrowth of amputated tube feet (sensory and motor appendages and spines in the sea urchin, Lytechinus variegatus. The ability to manipulate regeneration was demonstrated by concentration-dependent inhibition of regrowth of spines and tube feet by treatment with the mitotic inhibitor, vincristine. Treatment with the gamma-secretase inhibitor DAPT resulted in a concentration-dependent inhibition of regrowth, indicating that both tube feet and spine regeneration require functional Notch signaling. Stem cell markers (Piwi and Vasa were expressed in tube feet and spine tissue, and Vasa-positive cells were localized throughout the epidermis of tube feet by immunohistochemistry, suggesting the existence of multipotent progenitor cells in these highly regenerative appendages. The presence of Vasa protein in other somatic tissues (e.g. esophagus, radial nerve, and a sub-population of coelomocytes suggests that multipotent cells are present throughout adult sea urchins and may contribute to normal homeostasis in addition to regeneration. Mechanistic insight into the cellular pathways governing the tremendous regenerative capacity of echinoderms may reveal processes that can be modulated for regenerative therapies, shed light on the evolution of regeneration, and enable the ability to predict how these processes will respond to changing environmental conditions.

  1. Function of Integrin-Linked Kinase in Modulating the Stemness of IL-6–Abundant Breast Cancer Cells by Regulating γ-Secretase–Mediated Notch1 Activation in Caveolae

    Directory of Open Access Journals (Sweden)

    En-Chi Hsu

    2015-06-01

    Full Text Available Interleukin-6 (IL-6 and Notch signaling are important regulators of breast cancer stem cells (CSCs, which drive the malignant phenotype through self-renewal, differentiation, and development of therapeutic resistance. We investigated the role of integrin-linked kinase (ILK in regulating IL-6–driven Notch1 activation and the ability to target breast CSCs through ILK inhibition. Ectopic expression/short hairpin RNA-mediated knockdown of ILK, pharmacological inhibition of ILK with the small molecule T315, Western blot analysis, immunofluorescence, and luciferase reporter assays were used to evaluate the regulation of IL-6–driven Notch1 activation by ILK in IL-6–producing triple-negative breast cancer cell lines (MDA-MB-231, SUM-159 and in MCF-7 and MCF-7IL-6 cells. The effects of ILK on γ-secretase complex assembly and cellular localization were determined by immunofluorescence, Western blots of membrane fractions, and immunoprecipitation. In vivo effects of T315-induced ILK inhibition on CSCs in SUM-159 xenograft models were assessed by mammosphere assays, flow cytometry, and tumorigenicity assays. Results show that the genetic knockdown or pharmacological inhibition of ILK suppressed Notch1 activation and the abundance of the γ-secretase components presenilin-1, nicastrin, and presenilin enhancer 2 at the posttranscriptional level via inhibition of caveolin-1-dependent membrane assembly of the γ-secretase complex. Accordingly, knockdown of ILK inhibited breast CSC-like properties in vitro and the breast CSC subpopulation in vivo in xenograft tumor models. Based on these findings, we propose a novel function of ILK in regulating γ-secretase–mediated Notch1 activation, which suggests the targeting of ILK as a therapeutic approach to suppress IL-6–induced breast CSCs.

  2. The crystal structure of a partial mouse Notch-1 ankyrin domain: Repeats 4 through 7 preserve an ankyrin fold

    Energy Technology Data Exchange (ETDEWEB)

    Lubman, Olga Y.; Kopan, Raphael; Waksman, Gabriel; Korolev, Sergey (Birbeck); (St. Louis-MED); (WU-MED)

    2010-07-20

    Folding and stability of proteins containing ankyrin repeats (ARs) is of great interest because they mediate numerous protein-protein interactions involved in a wide range of regulatory cellular processes. Notch, an ankyrin domain containing protein, signals by converting a transcriptional repression complex into an activation complex. The Notch ANK domain is essential for Notch function and contains seven ARs. Here, we present the 2.2 {angstrom} crystal structure of ARs 4-7 from mouse Notch 1 (m1ANK). These C-terminal repeats were resistant to degradation during crystallization, and their secondary and tertiary structures are maintained in the absence of repeats 1-3. The crystallized fragment adopts a typical ankyrin fold including the poorly conserved seventh AR, as seen in the Drosophila Notch ANK domain (dANK). The structural preservation and stability of the C-terminal repeats shed a new light onto the mechanism of hetero-oligomeric assembly during Notch-mediated transcriptional activation.

  3. Activation of Notch1 inhibits medial edge epithelium apoptosis in all-trans retinoic acid-induced cleft palate in mice.

    Science.gov (United States)

    Zhang, Yadong; Dong, Shiyi; Wang, Weicai; Wang, Jianning; Wang, Miao; Chen, Mu; Hou, Jinsong; Huang, Hongzhang

    2016-08-26

    Administration of all-trans retinoic acid (atRA) on E12.0 (embryonic day 12.0) leads to failure of medial edge epithelium (MEE) disappearance and cleft palate. However, the molecular mechanism underlying the relationship between atRA and MEE remains to be identified. In this study, atRA (200 mg/kg) administered by gavage induced a 75% incidence of cleft palate in C57BL/6 mice. Notch1 was up-regulated in MEE cells in the atRA-treated group compared with the controls at E15.0, together with reduced apoptosis and elevated proliferation. Next, we investigated the mechanisms underlying atRA, Notch1 and MEE degradation in palate organ culture. Our results revealed that down-regulation of Notch1 partially rescued the inhibition of atRA-induced palate fusion. Molecular analysis indicated that atRA increased the expression of Notch1 and Rbpj and decreased the expression of P21. In addition, depletion of Notch1 expression decreased the expression of Rbpj and increased the expression of P21. Moreover, inhibition of Rbpj expression partially reversed atRA-induced MEE persistence and increased P21 expression. These findings demonstrate that atRA inhibits MEE degradation, which in turn induces a cleft palate, possibly through the Notch1/RBPjk/P21 signaling pathway. PMID:27343556

  4. Effect of hypoxia on Notch signaling of trophoblasts%缺氧对滋养细胞Notch信号通路的影响

    Institute of Scientific and Technical Information of China (English)

    张娜; 吴媛媛; 刘海意; 龚洵; 石鑫玮; 李宇琪; 乔福元

    2012-01-01

    Objective: To investigate the change of Notch signaling in hypoxic trophoblasts. Methods: By using quantitative real -time PCR, we detected the expression of Notchl and Jaggedl in human extravillous trophoblast cell line TEV -1, which was cultured under Cobalt chloride ( CoCl2) in vitro. Results; (1) The mRNA expression of Notchl in control groups showed no difference as compared with hypoxic groups ( P > 0. 05). (2) The mRNA expression of Jaggedl was gradually reduced with the extending of time and was significantly decreased as compared with hypoxic groups (P <0. 05). Conclusions; The imbalance expression of Notchl and Jaggedl in hypoxic trophoblasts may contribute to functional regulation of trophoblasts.%目的 探讨缺氧条件下Notch信号通路在滋养细胞中的表达改变.方法 利用实时荧光定量PCR( RT -qPCR)技术检测二氯化钴(CoCl2)化学缺氧条件下人早孕绒毛滋养细胞株(the human first - trimester extravillous trophoblast cell line,TEV -1)中Notch1及Jagged1 mRNA的表达情况.结果 (1)与正常对照组相比,缺氧条件下滋养细胞Notch1 mRNA表达量无明显变化(P>0.05).(2)随着缺氧时间的延长,滋养细胞Jagged1 mRNA表达量逐渐降低,与正常对照组相比具有统计学意义(P<0.05).结论 缺氧条件下滋养细胞Notch1及Jagged1表达平衡失调,可能参与滋养细胞功能调控.

  5. The Mammalian Orthologs of Drosophila Lgd, CC2D1A and CC2D1B, Function in the Endocytic Pathway, but Their Individual Loss of Function Does Not Affect Notch Signalling.

    Directory of Open Access Journals (Sweden)

    Nadja Drusenheimer

    2015-12-01

    Full Text Available CC2D1A and CC2D1B belong to the evolutionary conserved Lgd protein family with members in all multi-cellular animals. Several functions such as centrosomal cleavage, involvement in signalling pathways, immune response and synapse maturation have been described for CC2D1A. Moreover, the Drosophila melanogaster ortholog Lgd was shown to be involved in the endosomal trafficking of the Notch receptor and other transmembrane receptors and physically interacts with the ESCRT-III component Shrub/CHMP4. To determine if this function is conserved in mammals we generated and characterized Cc2d1a and Cc2d1b conditional knockout mice. While Cc2d1b deficient mice displayed no obvious phenotype, we found that Cc2d1a deficient mice as well as conditional mutants that lack CC2D1A only in the nervous system die shortly after birth due to respiratory distress. This finding confirms the suspicion that the breathing defect is caused by the central nervous system. However, an involvement in centrosomal function could not be confirmed in Cc2d1a deficient MEF cells. To analyse an influence on Notch signalling, we generated intestine specific Cc2d1a mutant mice. These mice did not display any alterations in goblet cell number, proliferating cell number or expression of the Notch reporter Hes1-emGFP, suggesting that CC2D1A is not required for Notch signalling. However, our EM analysis revealed that the average size of endosomes of Cc2d1a mutant cells, but not Cc2d1b mutant cells, is increased, indicating a defect in endosomal morphogenesis. We could show that CC2D1A and its interaction partner CHMP4B are localised on endosomes in MEF cells, when the activity of the endosomal protein VPS4 is reduced. This indicates that CC2D1A cycles between the cytosol and the endosomal membrane. Additionally, in rescue experiments in D. melanogaster, CC2D1A and CC2D1B were able to functionally replace Lgd. Altogether our data suggest a functional conservation of the Lgd protein family

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

    Science.gov (United States)

    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. The Curcumin Analog C-150, Influencing NF-κB, UPR and Akt/Notch Pathways Has Potent Anticancer Activity In Vitro and In Vivo.

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    László Hackler

    Full Text Available C-150 a Mannich-type curcumin derivative, exhibited pronounced cytotoxic effects against eight glioma cell lines at micromolar concentrations. Inhibition of cell proliferation by C-150 was mediated by affecting multiple targets as confirmed at transcription and protein level. C-150 effectively reduced the transcription activation of NFkB, inhibited PKC-alpha which are constitutively over-expressed in glioblastoma. The effects of C-150 on the Akt/ Notch signaling were also demonstrated in a Drosophila tumorigenesis model. C-150 reduced the number of tumors in Drosophila with similar efficacy to mitoxantrone. In an in vivo orthotopic glioma model, C-150 significantly increased the median survival of treated nude rats compared to control animals. The multi-target action of C-150, and its preliminary in vivo efficacy would render this curcumin analogue as a potent clinical candidate against glioblastoma.

  8. Restoration of p53 Expression in Human Cancer Cell Lines Upregulates the Expression of Notch1: Implications for Cancer Cell Fate Determination after Genotoxic Stress

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    Fatouma Alimirah

    2007-05-01

    Full Text Available Following genotoxic stress, transcriptional activation of target genes by p53 tumor suppressor is critical in cell fate determination. Here we report that the restoration of p53 function in human cancer cell lines that are deficient in p53 function upregulated the expression of Notch1. Interestingly, the expression of wild-type p53 in human prostate and breast cancer cell lines correlated well with increased expression of Notch1. Furthermore, knockdown of p53 expression in cancer cells that express wild-type p53 resulted in reduced expression of Notch1. Importantly, genotoxic stress to cancer cells that resulted in activation of p53 also upregulated the expression of Notch1. Moreover, p53mediated induction of Notch1 expression was associated with stimulation of the activity of Notch-responsive reporters. Notably, p53 differentially regulated the expression of Notch family members: expression of Notch2 and Notch4 was not induced by p53. Significantly, treatment of cells with gamma secretase inhibitor, an inhibitor of Notch signaling, increased susceptibility to apoptosis in response to genotoxic stress. Together, our observations suggest that p53mediated upregulation of Notch1 expression in human cancer cell lines contributes to cell fate determination after genotoxic stress.

  9. Self-renewal of CD133(hi) cells by IL6/Notch3 signalling regulates endocrine resistance in metastatic breast cancer.

    Science.gov (United States)

    Sansone, Pasquale; Ceccarelli, Claudio; Berishaj, Marjan; Chang, Qing; Rajasekhar, Vinagolu K; Perna, Fabiana; Bowman, Robert L; Vidone, Michele; Daly, Laura; Nnoli, Jennifer; Santini, Donatella; Taffurelli, Mario; Shih, Natalie N C; Feldman, Michael; Mao, Jun J; Colameco, Christopher; Chen, Jinbo; DeMichele, Angela; Fabbri, Nicola; Healey, John H; Cricca, Monica; Gasparre, Giuseppe; Lyden, David; Bonafé, Massimiliano; Bromberg, Jacqueline

    2016-02-09

    The mechanisms of metastatic progression from hormonal therapy (HT) are largely unknown in luminal breast cancer. Here we demonstrate the enrichment of CD133(hi)/ER(lo) cancer cells in clinical specimens following neoadjuvant endocrine therapy and in HT refractory metastatic disease. We develop experimental models of metastatic luminal breast cancer and demonstrate that HT can promote the generation of HT-resistant, self-renewing CD133(hi)/ER(lo)/IL6(hi) cancer stem cells (CSCs). HT initially abrogates oxidative phosphorylation (OXPHOS) generating self-renewal-deficient cancer cells, CD133(hi)/ER(lo)/OXPHOS(lo). These cells exit metabolic dormancy via an IL6-driven feed-forward ER(lo)-IL6(hi)-Notch(hi) loop, activating OXPHOS, in the absence of ER activity. The inhibition of IL6R/IL6-Notch pathways switches the self-renewal of CD133(hi) CSCs, from an IL6/Notch-dependent one to an ER-dependent one, through the re-expression of ER. Thus, HT induces an OXPHOS metabolic editing of luminal breast cancers, paradoxically establishing HT-driven self-renewal of dormant CD133(hi)/ER(lo) cells mediating metastatic progression, which is sensitive to dual targeted therapy.

  10. Molecular analysis of the notch repressor-complex in Drosophila: characterization of potential hairless binding sites on suppressor of hairless.

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    Patricia Kurth

    Full Text Available The Notch signalling pathway mediates cell-cell communication in a wide variety of organisms. The major components, as well as the basic mechanisms of Notch signal transduction, are remarkably well conserved amongst vertebrates and invertebrates. Notch signalling results in transcriptional activation of Notch target genes, which is mediated by an activator complex composed of the DNA binding protein CSL, the intracellular domain of the Notch receptor, and the transcriptional coactivator Mastermind. In the absence of active signalling, CSL represses transcription from Notch target genes by the recruitment of corepressors. The Notch activator complex is extremely well conserved and has been studied in great detail. However, Notch repressor complexes are far less understood. In Drosophila melanogaster, the CSL protein is termed Suppressor of Hairless [Su(H]. Su(H functions as a transcriptional repressor by binding Hairless, the major antagonist of Notch signalling in Drosophila, which in turn recruits two general corepressors--Groucho and C-terminal binding protein CtBP. Recently, we determined that the C-terminal domain (CTD of Su(H binds Hairless and identified a single site in Hairless, which is essential for contacting Su(H. Here we present additional biochemical and in vivo studies aimed at mapping the residues in Su(H that contact Hairless. Focusing on surface exposed residues in the CTD, we identified two sites that affect Hairless binding in biochemical assays. Mutation of these sites neither affects binding to DNA nor to Notch. Subsequently, these Su(H mutants were found to function normally in cellular and in vivo assays using transgenic flies. However, these experiments rely on Su(H overexpression, which does not allow for detection of quantitative or subtle differences in activity. We discuss the implications of our results.

  11. CD99 regulates neural differentiation of Ewing sarcoma cells through miR-34a-Notch-mediated control of NF-κB signaling.

    Science.gov (United States)

    Ventura, S; Aryee, D N T; Felicetti, F; De Feo, A; Mancarella, C; Manara, M C; Picci, P; Colombo, M P; Kovar, H; Carè, A; Scotlandi, K

    2016-07-28

    Sarcomas are mesenchymal tumors characterized by blocked differentiation process. In Ewing sarcoma (EWS) both CD99 and EWS-FLI1 concur to oncogenesis and inhibition of differentiation. Here, we demonstrate that uncoupling CD99 from EWS-FLI1 by silencing the former, nuclear factor-κB (NF-κB) signaling is inhibited and the neural differentiation program is re-established. NF-κB inhibition passes through miR-34a-mediated repression of Notch pathway. CD99 counteracts EWS-FLI1 in controlling NF-κB signaling through the miR-34a, which is increased and secreted into exosomes released by CD99-silenced EWS cells. Delivery of exosomes from CD99-silenced cells was sufficient to induce neural differentiation in recipient EWS cells through miR-34a inhibition of Notch-NF-κB signaling. Notably, even the partial delivery of CD99 small interfering RNA may have a broad effect on the entire tumor cell population owing to the spread operated by their miR-34a-enriched exosomes, a feature opening to a new therapeutic option. PMID:26616853

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

  14. Endocardial to myocardial notch-wnt-bmp axis regulates early heart valve development.

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    Yidong Wang

    Full Text Available Endocardial to mesenchymal transformation (EMT is a fundamental cellular process required for heart valve formation. Notch, Wnt and Bmp pathways are known to regulate this process. To further address how these pathways coordinate in the process, we specifically disrupted Notch1 or Jagged1 in the endocardium of mouse embryonic hearts and showed that Jagged1-Notch1 signaling in the endocardium is essential for EMT and early valvular cushion formation. qPCR and RNA in situ hybridization assays reveal that endocardial Jagged1-Notch1 signaling regulates Wnt4 expression in the atrioventricular canal (AVC endocardium and Bmp2 in the AVC myocardium. Whole embryo cultures treated with Wnt4 or Wnt inhibitory factor 1 (Wif1 show that Bmp2 expression in the AVC myocardium is dependent on Wnt activity; Wnt4 also reinstates Bmp2 expression in the AVC myocardium of endocardial Notch1 null embryos. Furthermore, while both Wnt4 and Bmp2 rescue the defective EMT resulting from Notch inhibition, Wnt4 requires Bmp for its action. These results demonstrate that Jagged1-Notch1 signaling in endocardial cells induces the expression of Wnt4, which subsequently acts as a paracrine factor to upregulate Bmp2 expression in the adjacent AVC myocardium to signal EMT.

  15. Design of UWB Filter with Notch Band for WLAN (5.3-5.8 GHz Signal Interference Rejection

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    Vinay Kumar Sharma

    2014-10-01

    Full Text Available In this letter, a design of Compact Ultra-Wideband (UWB bandpass filter with a switchable notch band for WLAN (5.3-5.9GHz interference rejection is proposed. As 5.3-5.9GHz wireless local area network (WLAN is existed in UWB spectrum range (3.1 -10.6GHz and may interfere with UWB system operation. The UWB bandpass filter is implemented using a basic multiple mode resonator (MMR structure feed by interdigital coupled lines for achieving higher degree of coupling. The notch band is obtained using a etched slot on main microstrip line. The centre frequency and bandwidth of notch band is optimized. The filter is compact in size with dimension 37.4 X 25 mm2 .The electromagnetic simulation software, Computer Simulation Technology Microwave Studio (CST MWS is used for the simulation and analysis of the designed structure. For fabrication of this structure Rogers RT5880 substrate of thickness 0.4 mm and dielectric constant 2.2 is used. Measured and simulated results show good agreement.

  16. Effects of voluntary wheel exercise on spatial learning and memory and Notch signal pathway of mice%自主跑轮运动对小鼠空间学习记忆及Notch信号通路的影响

    Institute of Scientific and Technical Information of China (English)

    张宪亮; 徐波; 陆乐; 何标; 余锋; 季浏

    2014-01-01

    the mice in group C;in Western blot test, the expression of NICD in hippocampus of the mice in group R increased significantly;in RT-PCR test, the mRNA expression levels of Jagged-1, Notch-1, PS-1 and Hes-1 in hippocampus of the mice in group R increased significantly as compared with those of the mice in group C. The said findings indicated that 8-week voluntary wheel exercise activated Notch signal pathway, en-hanced the spatial learning and memory ability of hippocampus.

  17. Notch-RBP-J signaling regulates the mobilization and function of endothelial progenitor cells by dynamic modulation of CXCR4 expression in mice.

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    Lin Wang

    Full Text Available Bone marrow (BM-derived endothelial progenitor cells (EPC have therapeutic potentials in promoting tissue regeneration, but how these cells are modulated in vivo has been elusive. Here, we report that RBP-J, the critical transcription factor mediating Notch signaling, modulates EPC through CXCR4. In a mouse partial hepatectomy (PHx model, RBP-J deficient EPC showed attenuated capacities of homing and facilitating liver regeneration. In resting mice, the conditional deletion of RBP-J led to a decrease of BM EPC, with a concomitant increase of EPC in the peripheral blood. This was accompanied by a down-regulation of CXCR4 on EPC in BM, although CXCR4 expression on EPC in the circulation was up-regulated in the absence of RBP-J. PHx in RBP-J deficient mice induced stronger EPC mobilization. In vitro, RBP-J deficient EPC showed lowered capacities of adhering, migrating, and forming vessel-like structures in three-dimensional cultures. Over-expression of CXCR4 could at least rescue the defects in vessel formation by the RBP-J deficient EPC. These data suggested that the RBP-J-mediated Notch signaling regulated EPC mobilization and function, at least partially through dynamic modulation of CXCR4 expression. Our findings not only provide new insights into the regulation of EPC, but also have implications for clinical therapies using EPC in diseases.

  18. Notch信号通路参与免疫炎症反应的研究进展%Research progress of notch signal pathway in immuno-inflammatory response

    Institute of Scientific and Technical Information of China (English)

    韩晗; 侯立朝

    2012-01-01

    背景 Notch信号通路是影响细胞命运的重要通路之一,在细胞分化、增殖、存活和发育中起关键作用.近年来研究表明,Notch信号还参与许多病理生理过程和多种疾病的发生、发展.目的 研究Notch信号通路在免疫炎症反应之间的作用,寻求新的免疫炎症调控靶点.内容 主要综述了Notch信号通路与免疫炎症反应的密切关系,以及对炎症性疾病的调控.趋向 Notch信号在各种炎症性疾病包括全身炎症反应综合征(systemic inflammatory response syndrome,SIRS)及脓毒症中的具体机制仍不清楚,还需更深入的研究.%Background Notch signal pathway is one of most important pathways,which plays a key role in cell fate,differentiation, proliferation, survival and development.Recent researches show that notch signal contributes to many pathophysiological process and diseases. Objective To investigate the roles of notch signal pathway in immuno -inflammatory response,and to seek new target regulating immuno-inflammation. Content This article reviews the intimate relationship between notch signal pathway and immuno-inflammatory response,as well as the regulating roles of notch signal in inflammatory diseases.Trend The concrete mechanism of notch signal in various inflammatory diseases including systemic inflammatory response syndrome (SIRS) and sepsis is still unclear,which needs further research.

  19. Fringe-mediated extension of O-linked fucose in the ligand-binding region of Notch1 increases binding to mammalian Notch ligands.

    Science.gov (United States)

    Taylor, Paul; Takeuchi, Hideyuki; Sheppard, Devon; Chillakuri, Chandramouli; Lea, Susan M; Haltiwanger, Robert S; Handford, Penny A

    2014-05-20

    The Notch signaling pathway is essential for many aspects of development, cell fate determination, and tissue homeostasis. Notch signaling can be modulated by posttranslational modifications to the Notch receptor, which are known to alter both ligand binding and receptor activation. We have modified the ligand-binding region (EGF domains 11-13) of human Notch1 (hN1) with O-fucose and O-glucose glycans and shown by flow cytometry and surface plasmon resonance that the Fringe-catalyzed addition of GlcNAc to the O-fucose at T466 in EGF12 substantially increases binding to Jagged1 and Delta-like 1 (DLL1) ligands. We have subsequently determined the crystal structures of EGF domains 11-13 of hN1 modified with either the O-fucose monosaccharide or the GlcNAc-fucose disaccharide at T466 of EGF12 and observed no change in backbone structure for each variant. Collectively, these data demonstrate a role for GlcNAc in modulating the ligand-binding site in hN1 EGF12, resulting in an increased affinity of this region for ligands Jagged1 and DLL1. We propose that this finding explains the Fringe-catalyzed enhancement of Notch-Delta signaling observed in flies and humans, but suggest that the inhibitory effect of Fringe on Jagged/Serrate mediated signaling involves other regions of Notch.

  20. VEGF-VEGFR2,Dll4-Notch1信号通路在基底细胞癌和鲍温病中的表达及关系%VEGF-VEGFR2, Relationship and Expression of Dll4-Notch1 Signaling Pathway in the Basal Cell Carcinoma and Bowen's Disease

    Institute of Scientific and Technical Information of China (English)

    孙晓佳; 郝彩玲; 丁楠; 赵琦

    2014-01-01

    Objective To compare the expression and relationship of VEGF/VEGFR2, Dl 4/Notch1 signaling pathway in dif erent types of epithelial tumors. Methods The expression of VEGF,VEGFR2,Dl 4 and Notch1 in 60 basal cellcarcinoma tissue and 26 Bowen's disease were observed by using immunohistochemistry. The relationship of VEGF,VEGFR2,Dl 4 and Notch1 were af irmed by correlation analysis. Results VEGF and VEGFR2 expression in the basal cellcarcinom group is higher than the Bowen's disease and the control ( <0.05), while Dl 4 and Notch1 is significantly lower than the the Bowen's disease and the control ( <0.05). VEGF and VEGFR2 expression in the Bowen's disease is higher than the control ( <0.05), for Dll4 and Notch1 is significantly lower than the control ( <0.05).Conclusion VEGF、VEGFR2、Dll4、Notch1 play a rool in the development and prognosis of dif erent epithelial skin tumor.%目的:比较VEGF-VEGFR2,Dl 4-Notch1信号通路在不同类型上皮源性肿瘤中的表达及关系。方法采用免疫组化方法,对60例基底细胞癌和26例鲍温病的石蜡包埋标本进行VEGF、VEGFR2、Dl 4、Notch1蛋白水平的检测,并进行相关性分析。结果 VEGF、VEGFR2、在基底细胞癌中的表达高于鲍温病及正常皮肤组织,差异具有统计学意义(P<0.05)。而Dl 4、Notch1在基底细胞癌中的表达低于鲍温病及正常皮肤组织,差异具有统计学意义(P<0.05)。结论 VEGF、VEGFR2、Dl 4、Notch1与不同种类上皮源性皮肤肿瘤的发展和预后有关。

  1. Expression and significance of DLL4--Notch signaling pathway in the differentiation of human umbilical cord derived mesenchymal stem cells into cardiomyocytes induced by 5-azacytidine.

    Science.gov (United States)

    Zhu, Li; Ruan, Zhongbao; Yin, Yigang; Chen, Gecai

    2015-01-01

    hUCMSCs were isolated and purified from the umbilical cords of normal or cesarean term deliveries under sterile conditions. Flow cytometry analysis revealed that CD13, CD29, CD44, CD90, and CD105 were highly expressed on the surface of passage-3 hUCMSCs, but negative for CD31, CD34, CD45, and HLA-DR. Immunocytochemistry showed that 5-azacytidine (5-aza) could induce the cTnI expression of hUCMSCs. RT-PCR showed that a stable higher level expression of DLL4 and Notch1 gene in 5-aza-induced group was observed compared to that in the control group. There was a higher expression level in the induced group. Compared with control group, the expression levels of Notch1 were, respectively, increased 6.60, 7.36, 7.595, and 7.805 times at 1, 3, 5, and 7 days after intervention of 5-aza. Statistically higher Ct value of Notch1 mRNA in induced group was observed in comparison with that of the control group (0.51 ± 0.21 vs 7.85 ± 0.35, t = 35.98, P < 0.01). The expression level of DLL4 increased stably compared with the control group. Compared with control group, the expression levels of DLL4 were, respectively, increased 11.53, 10.1, 10.17, and 11.46 times at 1, 3, 5, and 7 days after intervention of 5-aza. There was a significant difference of DLL4 Ct value between the 5-aza-induced group and the control group (1.60 ± 0.49 vs 12.42 ± 0.73, t = 11.71, P < 0.01). In conclusion, hUCMSCs can be differentiated into myocardial cells in vitro. The DLL4-Notch signaling pathway may be involved in the differentiation of hUCMSCs into cardiomyocytes induced by 5-aza. PMID:25343938

  2. Adipocyte activation of cancer stem cell signaling in breast cancer

    Institute of Scientific and Technical Information of China (English)

    Benjamin; Wolfson; Gabriel; Eades; Qun; Zhou

    2015-01-01

    Signaling within the tumor microenvironment has a critical role in cancer initiation and progression. Adipocytes, one of the major components of the breast microenvironment,have been shown to provide pro-tumorigenic signals that promote cancer cell proliferation and invasiveness in vitro and tumorigenicity in vivo. Adipocyte secreted factors such as leptin and interleukin-6(IL-6) have a paracrine effect on breast cancer cells. In adipocyte-adjacent breast cancer cells, the leptin and IL-6 signaling pathways activate janus kinase 2/signal transducer and activatorof transcription 5, promoting the epithelial-mesenchymal transition, and upregulating stemness regulators such as Notch, Wnt and the Sex determining region Y-box 2/octamer binding transcription factor 4/Nanog signaling axis. In this review we will summarize the major signaling pathways that regulate cancer stem cells in breast cancer and describe the effects that adipocyte secreted IL-6 and leptin have on breast cancer stem cell signaling. Finally we will introduce a new potential treatment paradigm of inhibiting the adipocyte-breast cancer cell signaling via targeting the IL-6 or leptin pathways.

  3. Notch信号通路与心脏发育、先天性心脏病及心肌再生%Notch signaling pathway and its role in cardiac development, congenital heart disease and myocardial regeneration

    Institute of Scientific and Technical Information of China (English)

    周学亮

    2012-01-01

    Notch signaling is essential for cell fate decisions, cellular development, differentiation, proliferation, apoptosis, adhesion and epithelial-to-mesenchymal transition. Notch signaling plays a critical role during mammalian cardiogenesis, and is closely related to myocardial regeneration and repair. The mutations in the Notch signaling has been associated with human congenital heart diseases. Therefore, this review focuses on the progress of Notch signaling and its role in cardiac development, congenital heart disease and myocardial regeneration.%Notch信号通路在细胞决定、发育、分化、增殖、凋亡、粘附及上皮-间质细胞转化过程中发挥重要作用,并参与了心脏发育的关键过程,也与心肌再生修复密切相关,Notch位点突变可引起一系列心脏畸形.本综述将集中讨论Notch信号通路及其在心脏发育、先天性心脏病和心肌再生中的作用.

  4. A Self-commissioning Notch Filter for Active Damping in a Three-Phase LCL -Filter-Based Grid-Tie Converter

    DEFF Research Database (Denmark)

    Pena-Alzola, Rafael; Liserre, Marco; Blaabjerg, Frede;

    2014-01-01

    LCL-filters are a cost-effective solution to mitigate harmonic current content in grid-tie converters. In order to avoid stability problems, the resonance frequency of LCL-filters can be damped with active techniques that remove dissipative elements but increase control complexity. A notch filter...

  5. Zebrafish reporter lines reveal in vivo signaling pathway activities involved in pancreatic cancer

    Directory of Open Access Journals (Sweden)

    Marco Schiavone

    2014-07-01

    Full Text Available Pancreatic adenocarcinoma, one of the worst malignancies of the exocrine pancreas, is a solid tumor with increasing incidence and mortality in industrialized countries. This condition is usually driven by oncogenic KRAS point mutations and evolves into a highly aggressive metastatic carcinoma due to secondary gene mutations and unbalanced expression of genes involved in the specific signaling pathways. To examine in vivo the effects of KRASG12D during pancreatic cancer progression and time correlation with cancer signaling pathway activities, we have generated a zebrafish model of pancreatic adenocarcinoma in which eGFP-KRASG12D expression was specifically driven to the pancreatic tissue by using the GAL4/UAS conditional expression system. Outcrossing the inducible oncogenic KRASG12D line with transgenic zebrafish reporters, harboring specific signaling responsive elements of transcriptional effectors, we were able to follow TGFβ, Notch, Bmp and Shh activities during tumor development. Zebrafish transgenic lines expressing eGFP-KRASG12D showed normal exocrine pancreas development until 3 weeks post fertilization (wpf. From 4 to 24 wpf we observed several degrees of acinar lesions, characterized by an increase in mesenchymal cells and mixed acinar/ductal features, followed by progressive bowel and liver infiltrations and, finally, highly aggressive carcinoma. Moreover, live imaging analysis of the exocrine pancreatic tissue revealed an increasing number of KRAS-positive cells and progressive activation of TGFβ and Notch pathways. Increase in TGFβ, following KRASG12D activation, was confirmed in a concomitant model of medulloblastoma (MDB. Notch and Shh signaling activities during tumor onset were different between MDB and pancreatic adenocarcinoma, indicating a tissue-specific regulation of cell signaling pathways. Moreover, our results show that a living model of pancreatic adenocarcinoma joined with cell signaling reporters is a suitable

  6. The clathrin-binding motif and the J-domain of Drosophila Auxilin are essential for facilitating Notch ligand endocytosis

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    Chang Henry C

    2008-05-01

    Full Text Available Abstract Background Ligand endocytosis plays a critical role in regulating the activity of the Notch pathway. The Drosophila homolog of auxilin (dAux, a J-domain-containing protein best known for its role in the disassembly of clathrin coats from clathrin-coated vesicles, has recently been implicated in Notch signaling, although its exact mechanism remains poorly understood. Results To understand the role of auxilin in Notch ligand endocytosis, we have analyzed several point mutations affecting specific domains of dAux. In agreement with previous work, analysis using these stronger dAux alleles shows that dAux is required for several Notch-dependent processes, and its function during Notch signaling is required in the signaling cells. In support of the genetic evidences, the level of Delta appears elevated in dAux deficient cells, suggesting that the endocytosis of Notch ligand is disrupted. Deletion analysis shows that the clathrin-binding motif and the J-domain, when over-expressed, are sufficient for rescuing dAux phenotypes, implying that the recruitment of Hsc70 to clathrin is a critical role for dAux. However, surface labeling experiment shows that, in dAux mutant cells, Delta accumulates at the cell surface. In dAux mutant cells, clathrin appears to form large aggregates, although Delta is not enriched in these aberrant clathrin-positive structures. Conclusion Our data suggest that dAux mutations inhibit Notch ligand internalization at an early step during clathrin-mediated endocytosis, before the disassembly of clathrin-coated vesicles. Further, the inhibition of ligand endocytosis in dAux mutant cells possibly occurs due to depletion of cytosolic pools of clathrin via the formation of clathrin aggregates. Together, our observations argue that ligand endocytosis is critical for Notch signaling and auxilin participates in Notch signaling by facilitating ligand internalization.

  7. Notch maintains Drosophila type II neuroblasts by suppressing expression of the Fez transcription factor Earmuff.

    Science.gov (United States)

    Li, Xiaosu; Xie, Yonggang; Zhu, Sijun

    2016-07-15

    Notch signaling is crucial for maintaining neural stem cell (NSC) self-renewal and heterogeneity; however, the underlying mechanism is not well understood. In Drosophila, loss of Notch prematurely terminates the self-renewal of larval type II neuroblasts (NBs, the Drosophila NSCs) and transforms type II NBs into type I NBs. Here, we demonstrate that Notch maintains type II NBs by suppressing the activation of earmuff (erm) by Pointed P1 (PntP1). We show that loss of Notch or components of its canonical pathway leads to PntP1-dependent ectopic Erm expression in type II NBs. Knockdown of Erm significantly rescues the loss-of-Notch phenotypes, and misexpression of Erm phenocopies the loss of Notch. Ectopically expressed Erm promotes the transformation of type II NBs into type I NBs by inhibiting PntP1 function and expression in type II NBs. Our work not only elucidates a key mechanism of Notch-mediated maintenance of type II NB self-renewal and identity, but also reveals a novel function of Erm. PMID:27151950

  8. Developmental exposure to 2,3,7,8 tetrachlorodibenzo-p-dioxin attenuates later-life Notch1-mediated T cell development and leukemogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Ahrenhoerster, Lori S.; Leuthner, Tess C.; Tate, Everett R.; Lakatos, Peter A.; Laiosa, Michael D., E-mail: laiosa@uwm.edu

    2015-03-01

    Over half of T cell acute lymphoblastic leukemia (T-ALL) patients have activating mutations in the Notch gene. Moreover, the contaminant 2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD) is a known carcinogen that mediates its toxicity through the aryl hydrocarbon receptor (AHR), and crosstalk between activated AHR and Notch signaling pathways has previously been observed. Given the importance of Notch signaling in thymocyte development and T-ALL disease progression, we hypothesized that the activated AHR potentiates disease initiation and progression in an in vivo model of Notch1-induced thymoma. This hypothesis was tested utilizing adult and developmental exposure paradigms to TCDD in mice expressing a constitutively active Notch1 transgene (Notch{sup ICN-TG}). Following exposure of adult Notch{sup ICN-TG} mice to a single high dose of TCDD, we observed a significant increase in the efficiency of CD8 thymocyte generation. We next exposed pregnant mice to 3 μg/kg of TCDD throughout gestation and lactation to elucidate effects of developmental AHR activation on later-life T cell development and T-ALL-like thymoma susceptibility induced by Notch1. We found that the vehicle-exposed Notch{sup ICN-TG} offspring have a peripheral T cell pool heavily biased toward the CD4 lineage, while TCDD-exposed Notch{sup ICN-TG} offspring were biased toward the CD8 lineage. Furthermore, while the vehicle-exposed NotchICN-TG mice showed increased splenomegaly and B to T cell ratios indicative of disease, mice developmentally exposed to TCDD were largely protected from disease. These studies support a model where developmental AHR activation attenuates later-life Notch1-dependent impacts on thymocyte development and disease progression. - Highlights: • Adult mice exposed to 30 μg/kg TCDD have higher efficiency of CD8 thymocyte generation. • Mice carrying a constitutively active Notch transgene were exposed to 3 μg/kg TCDD throughout development. • Progression of Notch

  9. Real-time multi-signal frequency tracking with a bank of notch filters to estimate the respiratory rate from the ECG.

    Science.gov (United States)

    Mirmohamadsadeghi, Leila; Vesin, Jean-Marc

    2016-09-01

    Measuring the instantaneous frequency of a signal rapidly and accurately is essential in many applications. However, the instantaneous frequency by definition is a parameter difficult to determine. Fourier-based methods introduce estimation delays as computations are performed in a time-window. Instantaneous methods based on the Hilbert transform lack robustness. State-of-the-art adaptive filters yield accurate estimates, however, with an adaptation delay. In this study we propose an algorithm based on short length-3 FIR notch filters to estimate the instantaneous frequency of a signal at each sample, in a real-time manner and with very low delay. The output powers of a bank of the above-mentioned filters are used in a recursive weighting scheme to estimate the dominant frequency of the input. This scheme has been extended to process multiple inputs containing a common frequency by introducing an additional weighting scheme upon the inputs. The algorithm was tested on synthetic data and then evaluated on real biomedical data, i.e. the estimation of the respiratory rate from the electrocardiogram. It was shown that the proposed method provided more accurate estimates with less delay than those of state-of-the-art methods. By virtue of its simplicity and good performance, the proposed method is a worthy candidate to be used in biomedical applications, for example in health monitoring developments based on portable and automatic devices. PMID:27510318

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

    Science.gov (United States)

    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

  11. The significance of Notch1 compared with Notch3 in high metastasis and poor overall survival in hepatocellular carcinoma.

    Directory of Open Access Journals (Sweden)

    Liang Zhou

    Full Text Available BACKGROUND: The prognosis for patients with hepatocellular carcinoma (HCC is poor, and the mechanisms underlying the development of HCC remain unclear. Notch1 and Notch3 may be involved in malignant transformation, although their roles remain unknown. MATERIALS AND METHODS: HCC tissues were stained with anti-Notch1 or -Notch3 antibody. The migration and invasion capacities of the cells were measured with transwell cell culture chambers. RT-PCR was used to measure the expression of Notch1 and Notch3 mRNA. Additionally, western blot analysis was used to assess the protein expression of Notch1, Notch3, CD44v6, E-cadherin, matrix metalloproteinase-2 (MMP-2, MMP-9, and urokinase-type plasminogen activator (uPA. RNA interference was used to down-regulate the expression of Notch1 and Notch3. Cell viability was assessed using MTT. RESULTS: Based on immunohistochemistry, high Notch1 expression was correlated with tumor size, tumor grade, metastasis, venous invasion and AJCC TNM stage. High Notch3 expression was only strongly correlated with metastasis, venous invasion and satellite lesions. Kaplan-Meier curves demonstrated that patients with high Notch1 or Notch3 expression were at a significantly increased risk for shortened survival time. In vitro, the down-regulation of Notch1 decreased the migration and invasion capacities of HCC cells by regulating CD44v6, E-cadherin, MMP-2, MMP-9, and uPA via the COX-2 and ERK1/2 pathways. Down-regulation of Notch3 only decreased the invasion capacity of HCC cells by regulating MMP-2 and MMP-9 via the ERK1/2 pathway. CONCLUSIONS: Based on the migration and invasion of HCC, we hypothesize that targeting Notch1 may be more useful than Notch3 for designing novel preventive and therapeutic strategies for HCC in the near future.

  12. Notch信号通路在牙髓干细胞增殖和分化中的调控作用%The regulation of Notch signaling pathway in the proliferation and differentiation of dental pulp stem cells

    Institute of Scientific and Technical Information of China (English)

    武曦

    2011-01-01

    The Notch signaling pathway is an evolutionarily conserved signal transductional mechanism,controlling the fate of the cells through the interaction among cells.Dental pulp stem ceU is a kind of somatic stem cell with high proliferation and multiple differentiation potentials and plays a vitat role in tissue regeneration.This review describes the composition of the Notch signaling pathway and the molecular mechanism of Notch signaling on dental pujp stem ce11s regulation.%Notch信号通路是进化过程中高度保守的信号转导机制,通过细胞与细胞间的相互作用控制细胞的命运.牙髓干细胞是一种具有高度增殖和多向分化潜能的成体干细胞,在组织再生中发挥重要作用.该文就该信号通路的组成及其对牙髓+细胞调控的分子机制作一综述.

  13. Notch2 controls prolactin and insulin-like growth factor binding protein-1 expression in decidualizing human stromal cells of early pregnancy.

    Directory of Open Access Journals (Sweden)

    Gerlinde R Otti

    Full Text Available Decidualization, the transformation of the human uterine mucosa into the endometrium of pregnancy, is critical for successful implantation and embryonic development. However, key regulatory factors controlling differentiation of uterine stromal cells into hormone-secreting decidual cells have not been fully elucidated. Hence, we herein investigated the role of the Notch signaling pathway in human decidual stromal cells (HDSC isolated from early pregnancy samples. Immunofluorescence of first trimester decidual tissues revealed expression of Notch2 receptor and its putative, membrane-anchored interaction partners Jagged1, Delta-like (DLL 1 and DLL4 in stromal cells whereas other Notch receptors and ligands were absent from these cells. During in vitro differentiation with estrogen/progesterone (E2P4 and/or cyclic adenosine monophosphate (cAMP HDSC constitutively expressed Notch2 and weakly downregulated Jagged1 mRNA and protein, measured by quantitative PCR (qPCR and Western blotting, respectively. However, increased levels of DLL1 and DLL4 were observed in the decidualizing cultures. Transfection of a Notch luciferase reporter and qPCR of the Notch target gene hairy and enhancer of split 1 (HES1 revealed an induction of canonical Notch activity during in vitro differentiation. In contrast, treatment of HDSC with a chemical Notch/γ-secretase inhibitor decreased cAMP/E2P4-stimulated Notch luciferase activity, HES1 transcript levels and mRNA expression of the decidual marker genes prolactin (PRL and insulin-like growth factor binding protein 1 (IGFBP1. Similarly, siRNA-mediated gene silencing or antibody-mediated blocking of Notch2 diminished HES1, PRL and IGFBP1 mRNA levels as well as secreted PRL protein. In summary, the data suggest that canonical, Notch2-dependent signaling plays a role in human decidualization.

  14. lin-12 Notch functions in the adult nervous system of C. elegans

    Directory of Open Access Journals (Sweden)

    Tucey Tim M

    2005-07-01

    Full Text Available Abstract Background Notch signaling pathways are conserved across species and traditionally have been implicated in cell fate determination during embryonic development. Notch signaling components are also expressed postdevelopmentally in the brains of adult mice and Drosophila. Recent studies suggest that Notch signaling may play a role in the physiological, rather than developmental, regulation of neurons. Here, we investigate a new non-developmental role for Caenorhabditis elegans lin-12 Notch signaling in neurons regulating the spontaneous reversal rate during locomotion. Results The spontaneous reversal rate of C. elegans during normal locomotion is constant. Both lin-12 gain and loss of function mutant animals had significantly increased reversal rates compared to wild type controls. These defects were caused by lin-12 activity, because the loss of function defect could be rescued by a wild type lin-12 transgene. Furthermore, overexpression of lin-12 recapitulated the gain-of-function defect. Increasing or decreasing lin-12 activity in the postdevelopmental adult animal was sufficient to rapidly and reversibly increase reversals, thereby excluding a developmental role for lin-12. Although lin-12 is expressed in the vulval and somatic gonad lineages, we find that these tissues play no role in regulating reversal rates. In contrast, altering lin-12 activity specifically in the nervous system was sufficient to increase reversals. These behavioral changes require components of the canonical lin-12 signaling cascade, including the ligand lag-2 and the transcriptional effector lag-1. Finally, the C. elegans AMPA/kainate glutamate receptor homolog glr-1 shows strong genetic interactions with lin-12, suggesting that glr-1 and/or other glutamate gated channels may be targets of lin-12 regulation. Conclusion Our results demonstrate a neuronal role for lin-12 Notch in C. elegans and suggest that lin-12 acutely regulates neuronal physiology to

  15. The putative Notch ligand HyJagged is a transmembrane protein present in all cell types of adult Hydra and upregulated at the boundary between bud and parent

    Directory of Open Access Journals (Sweden)

    Tischer Susanne

    2011-09-01

    Full Text Available Abstract Background The Notch signalling pathway is conserved in pre-bilaterian animals. In the Cnidarian Hydra it is involved in interstitial stem cell differentiation and in boundary formation during budding. Experimental evidence suggests that in Hydra Notch is activated by presenilin through proteolytic cleavage at the S3 site as in all animals. However, the endogenous ligand for HvNotch has not been described yet. Results We have cloned a cDNA from Hydra, which encodes a bona-fide Notch ligand with a conserved domain structure similar to that of Jagged-like Notch ligands from other animals. Hyjagged mRNA is undetectable in adult Hydra by in situ hybridisation but is strongly upregulated and easily visible at the border between bud and parent shortly before bud detachment. In contrast, HyJagged protein is found in all cell types of an adult hydra, where it localises to membranes and endosomes. Co-localisation experiments showed that it is present in the same cells as HvNotch, however not always in the same membrane structures. Conclusions The putative Notch ligand HyJagged is conserved in Cnidarians. Together with HvNotch it may be involved in the formation of the parent-bud boundary in Hydra. Moreover, protein distribution of both, HvNotch receptor and HyJagged indicate a more widespread function for these two transmembrane proteins in the adult hydra, which may be regulated by additional factors, possibly involving endocytic pathways.

  16. Algorithm for Design of Digital Notch Filter Using Simulation

    Directory of Open Access Journals (Sweden)

    Amit Verma

    2013-08-01

    Full Text Available A smooth waveform is generated of low frequency signal can be achieved through the Digital Notch Filter. Noise can be easily eliminated from a speech signal by using a Notch filter. In this paper the design of notch filter using MATLAB has been designed and implemented. The performance and characteristics of the filter has been shown in the waveform in the conclusion part of the paper.

  17. Notch3 is activated by chronic hypoxia and contributes to the progression of human prostate cancer

    OpenAIRE

    Giovanna Danza; Claudia Di Serio; Maria Raffaella Ambrosio; Niccolò Sturli; Giuseppe Lonetto; Fabiana Rosati; Bruno Jim Rocca; Giuseppina Ventimiglia; Maria Teresa del Vecchio; Igor Prudovsky; Niccolò Marchionni; Francesca Tarantini

    2013-01-01

    Prostate cancer (PC) is still the second cause of cancer-related death among men. Although patients with metastatic presentation have an ominous outcome, the vast majority of PCs are diagnosed at an early stage. Nonetheless, even among patients with clinically localized disease the outcome may vary considerably. Other than androgen sensitivity, little is known about which other signaling pathways are deranged in aggressive, localized cancers. The elucidation of such pathways may help to devel...

  18. Genetic deletion of Rnd3 results in aqueductal stenosis leading to hydrocephalus through up-regulation of Notch signaling

    OpenAIRE

    Lin, Xi; Liu, Baohui; Yang, Xiangsheng; Yue, Xiaojing; Diao, Lixia; Jing WANG; Chang, Jiang

    2013-01-01

    Rho family guanosine triphosphatase (GTPase) 3 (Rnd3), a member of the small Rho GTPase family, is involved in the regulation of cell actin cytoskeleton dynamics, cell migration, and proliferation through the Rho kinase-dependent signaling pathway. We report a role of Rnd3 in the pathogenesis of hydrocephalus disorder. Mice with Rnd3 genetic deletion developed severe obstructive hydrocephalus with enlargement of the lateral and third ventricles, but not of the fourth ventricles. The cerebral ...

  19. The intracellular domains of Notch1 and Notch2 are functionally equivalent during development and carcinogenesis.

    Science.gov (United States)

    Liu, Zhenyi; Brunskill, Eric; Varnum-Finney, Barbara; Zhang, Chi; Zhang, Andrew; Jay, Patrick Y; Bernstein, Irv; Morimoto, Mitsuru; Kopan, Raphael

    2015-07-15

    Although Notch1 and Notch2 are closely related paralogs and function through the same canonical signaling pathway, they contribute to different outcomes in some cell and disease contexts. To understand the basis for these differences, we examined in detail mice in which the Notch intracellular domains (N1ICD and N2ICD) were swapped. Our data indicate that strength (defined here as the ultimate number of intracellular domain molecules reaching the nucleus, integrating ligand-mediated release and nuclear translocation) and duration (half-life of NICD-RBPjk-MAML-DNA complexes, integrating cooperativity and stability dependent on shared sequence elements) are the factors that underlie many of the differences between Notch1 and Notch2 in all the contexts we examined, including T-cell development, skin differentiation and carcinogenesis, the inner ear, the lung and the retina. We were able to show that phenotypes in the heart, endothelium, and marginal zone B cells are attributed to haploinsufficiency but not to intracellular domain composition. Tissue-specific differences in NICD stability were most likely caused by alternative scissile bond choices by tissue-specific γ-secretase complexes following the intracellular domain swap. Reinterpretation of clinical findings based on our analyses suggests that differences in outcome segregating with Notch1 or Notch2 are likely to reflect outcomes dependent on the overall strength of Notch signals. PMID:26062937

  20. NOTCH3 expression is induced in mural cells through an autoregulatory loop that requires endothelial-expressed JAGGED1.

    Science.gov (United States)

    Liu, Hua; Kennard, Simone; Lilly, Brenda

    2009-02-27

    Endothelial cells and mural cells (smooth muscle cells, pericytes, or fibroblasts) are known to communicate with one another. Their interactions not only serve to support fully functional blood vessels but also can regulate vessel assembly and differentiation or maturation. In an effort to better understand the molecular components of this heterotypic interaction, we used a 3D model of angiogenesis and screened for genes, which were modulated by coculturing of these 2 different cell types. In doing so, we discovered that NOTCH3 is one gene whose expression is robustly induced in mural cells by coculturing with endothelial cells. Knockdown by small interfering RNA revealed that NOTCH3 is necessary for endothelial-dependent mural cell differentiation, whereas overexpression of NOTCH3 is sufficient to promote smooth muscle gene expression. Moreover, NOTCH3 contributes to the proangiogenic abilities of mural cells cocultured with endothelial cells. Interestingly, we found that the expression of NOTCH3 is dependent on Notch signaling, because the gamma-secretase inhibitor DAPT blocked its upregulation. Furthermore, in mural cells, a dominant-negative Mastermind-like1 construct inhibited NOTCH3 expression, and endothelial-expressed JAGGED1 was required for its induction. Additionally, we demonstrated that NOTCH3 could promote its own expression and that of JAGGED1 in mural cells. Taken together, these data provide a mechanism by which endothelial cells induce the differentiation of mural cells through activation and induction of NOTCH3. These findings also suggest that NOTCH3 has the capacity to maintain a differentiated phenotype through a positive-feedback loop that includes both autoregulation and JAGGED1 expression.

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

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    Carla Angulo‑Rojo

    2013-12-01

    Full Text Available 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.

  2. Notch intracellular domain overexpression in adipocytes confers lipodystrophy in mice

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    Dionysios V. Chartoumpekis

    2015-07-01

    Conclusions: Increased Notch signaling in adipocytes in mice results in blocked expansion of white adipose tissue which leads to ectopic accumulation of lipids and insulin resistance, thus to a lipodystrophic phenotype. These results suggest that further investigation of the role of Notch signaling in adipocytes could lead to the manipulation of this pathway for therapeutic interventions in metabolic disease.

  3. 间充质干细胞对哮喘大鼠肺组织Notch信号通路的表达调控%Regulation of mesenchymal stem cells expressing Notch signaling pathway of asthma

    Institute of Scientific and Technical Information of China (English)

    田丽君; 韩亭亭; 高萌; 吴福玲; 冯学斌; 王跃嗣

    2015-01-01

    Objective:To study the regulation of MSCs on the asthma;and to observe the expression of Notch signal in lung tissue of asthmatic rats.Methods:30 rats were randomly divided into 3 group :normal control group , asthma model group and MSC transplantation group.Making paraffin sections of lung tissue for pathological examination ,quantitative real-time PCR(RT-PCR) were used to identify the expression of Notch2 and Jagged1 mRNA in the rat lung tissue,and the expression of Notch2,Jagged1 were measured by Western blot.Results:Compared with normal control group and MSC transplantation group ,inflammatory cell infiltration and narrower airway were observed in asthma model group .The lever of Notch2,Jagged1 in asthma model group was higher than MSC transplantation group and normal control group ( P<0.05 ).Conclusion:Mesenchymal stem cells can affect the expression of the Notch signaling pathway in asthmatic rats ,and play a role in the treatment of asthma.%目的:研究间充质干细胞对哮喘的调控修复,观察对哮喘大鼠肺组织Notch信号通路表达的影响。方法:30只大鼠随机分为正常对照组、哮喘模型组和MSC移植组3组。造模结束后,制作肺组织石蜡切片进行病理学检查,实时荧光定量PCR( RT-PCR)方法检测Notch2和Jagged1 mRNA在大鼠肺组织中的表达水平,Western检测肺组织Notch2、Jagged1蛋白的表达。结果:哮喘组大量炎性细胞浸润,管腔狭窄,与哮喘组相比,MSC移植组气道炎症和黏液分泌显著下调,管腔黏膜无增厚,上皮细胞脱落减少,正常组无炎性改变。 MSC 移植组和正常组 Notch2、Jagged1 mRNA 表达较哮喘组下调, Notch2、Jagged1蛋白表达减少( P<0.05)。结论:间充质干细胞能影响哮喘大鼠中Notch信号通路的表达,对哮喘的治疗发挥一定的作用。

  4. Epidermal Notch1 recruits RORγ + group 3 innate lymphoid cells to orchestrate normal skin repair

    NARCIS (Netherlands)

    Z. Li (Zhi); T. Hodgkinson (Tom); E.J. Gothard (Elizabeth J.); S. Boroumand (Soulmaz); R. Lamb (Rebecca); I. Cummins (Ian); P. Narang (Priyanka); A. Sawtell (Amy); J. Coles (Jenny); G. Leonov (German); A. Reboldi (Andrea); C.D. Buckley; T. Cupedo (Tom); C. Siebel (Christian); A. Bayat (Ardeshir); M. Coles (Mark); C.A. Ambler (Carrie A.)

    2016-01-01

    textabstractNotch has a well-defined role in controlling cell fate decisions in the embryo and the adult epidermis and immune systems, yet emerging evidence suggests Notch also directs non-cell-autonomous signalling in adult tissues. Here, we show that Notch1 works as a damage response signal. Epide

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

    Energy Technology Data Exchange (ETDEWEB)

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

    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.

  6. Niclosamide, an old antihelminthic agent, demonstrates antitumor activity by blocking multiple signaling pathways of cancer stem cells

    OpenAIRE

    Pan, Jing-Xuan; Ding, Ke; Wang, Cheng-Yan

    2012-01-01

    Niclosamide, an oral antihelminthic drug, has been used to treat tapeworm infection for about 50 years. Niclosamide is also used as a molluscicide for water treatment in schistosomiasis control programs. Recently, several groups have independently discovered that niclosamide is also active against cancer cells, but its precise mechanism of antitumor action is not fully understood. Evidence supports that niclosamide targets multiple signaling pathways (NF-κB, Wnt/β-catenin, Notch, ROS, mTORC1,...

  7. Notch-induced Asb2 expression promotes protein ubiquitination by forming non-canonical E3 ligase complexes

    Institute of Scientific and Technical Information of China (English)

    Lei Nie; Ying Zhao; Wei Wu; Yuan-Zheng Yang; Hong-Cheng Wang; Xiao-Hong Sun

    2011-01-01

    Notch signaling controls multiple developmental processes, thus demanding versatile functions. We have previously shown that this may be partly achieved by accelerating ubiquitin-mediated degradation of important regulators of differentiation. However, the underlying mechanism was unknown. We now find that Notch signaling transcriptionally activates the gene encoding ankyrin-repeat SOCS box-containing protein 2(Asb2). Asb2 promotes the ubiquidnation of Notch targets such as E2A and Janus kinase(Jak)2, and a dominant-negative(DN)mutant of Asb2blocks Notch-induced degradation of these proteins. Asb2 likely binds Jak2 directly but associates with E2A through Skp2. We next provide evidence to suggest that Asb2 bridges the formation of non-canonical cullin-based complexes through interaction with not only ElonginB/C and Cullin(Cul)5, but also the F-box-containing protein, Skp2, which is known to associate with Skpl and Cull. Consistently, ablating the function of Cull or Cu15 using DN mutants or siRNAs protected both E2A and Jak2 from Asb2-mediated or Notch-induced degradation. By shifting monomeric E3ligase complexes to dimeric forms through activation of Asb2 transcription, Notch could effectively control the turnover of a variety of substrates and it exerts diverse effects on cell proliferation and differentiation.

  8. Notch, IL-1 and leptin crosstalk outcome (NILCO is critical for leptin-induced proliferation, migration and VEGF/VEGFR-2 expression in breast cancer.

    Directory of Open Access Journals (Sweden)

    Shanchun Guo

    Full Text Available High levels of pro-angiogenic factors, leptin, IL-1, Notch and VEGF (ligands and receptors, are found in breast cancer, which is commonly correlated with metastasis and lower survival of patients. We have previously reported that leptin induces the growth of breast cancer and the expression of VEGF/VEGFR-2 and IL-1 system. We hypothesized that Notch, IL-1 and leptin crosstalk outcome (NILCO plays an essential role in the regulation of leptin-mediated induction of proliferation/migration and expression of pro-angiogenic molecules in breast cancer. To test this hypothesis, leptin's effects on the expression and activation of Notch signaling pathway and VEGF/VEGFR-2/IL-1 were determined in mouse (4T1, EMT6 and MMT breast cancer cells. Remarkably, leptin up-regulated Notch1-4/JAG1/Dll-4, Notch target genes: Hey2 and survivin, together with IL-1 and VEGF/VEGFR-2. RNA knockdown and pharmacological inhibitors of leptin signaling significantly abrogated activity of reporter gene-luciferase CSL (RBP-Jk promoter, showing that it was linked to leptin-activated JAK2/STAT3, MAPK, PI-3K/mTOR, p38 and JNK signaling pathways. Interestingly, leptin upregulatory effects on cell proliferation/migration and pro-angiogenic factors Notch, IL-1 and VEGF/VEGFR-2 were abrogated by a γ-secretase inhibitor, DAPT, as well as siRNA against CSL. In addition, blockade of IL-1R tI inhibited leptin-induced Notch, Hey2 and survivin as well as VEGF/VEGFR-2 expression. These data suggest leptin is an inducer of Notch (expression/activation and IL-1 signaling modulates leptin effects on Notch and VEGF/VEGFR-2. We show for the first time that a novel unveiled crosstalk between Notch, IL-1 and leptin (NILCO occurs in breast cancer. Leptin induction of proliferation/migration and upregulation of VEGF/VEGFR-2 in breast cancer cells were related to an intact Notch signaling axis. NILCO could represent the integration of developmental, pro-inflammatory and pro-angiogenic signals

  9. In vivo Notch Reactivation in Differentiating Cochlear Hair Cells Induces Sox2 and Prox1 Expression but Does Not Disrupt Hair Cell Maturation

    OpenAIRE

    Liu, Zhiyong; Owen, Thomas; Fang, Jie; Srinivasan, R. Sathish; Zuo, Jian

    2012-01-01

    Notch signaling is active in mouse cochlear prosensory progenitors but declines in differentiating sensory hair cells (HCs). Overactivation of the Notch1 intracellular domain (NICD) in progenitors blocks HC fate commitment and/or differentiation. However, it is not known whether reactivation of NICD in differentiating HCs also interrupts their developmental program and reactivates its downstream targets. By analyzing Atoh1CreER+; Rosa26-NICDloxp/+ or Atoh1CreER+; Rosa26-NICDloxp/+; RBP-Jloxp/...

  10. Two Pathways for Importing GDP-fucose into the Endoplasmic Reticulum Lumen Function Redundantly in the O-Fucosylation of Notch in Drosophila*

    OpenAIRE

    Ishikawa, Hiroyuki O.; Ayukawa, Tomonori; Nakayama, Minoru; Higashi, Shunsuke; Kamiyama, Shin; Nishihara, Shoko; Aoki, Kazuhisa; Ishida, Nobuhiro; Sanai, Yutaka; Matsuno, Kenji

    2009-01-01

    Notch is a transmembrane receptor that shares homology with proteins containing epidermal growth factor-like repeats and mediates the cell-cell interactions necessary for many cell fate decisions. In Drosophila, O-fucosyltransferase 1 catalyzes the O-fucosylation of these epidermal growth factor-like repeats. This O-fucose elongates, resulting in an O-linked tetrasaccharide that regulates the signaling activities of Notch. Fucosyltransferases utilize GDP-fucose, which is synthesized in the cy...

  11. Frequency and distribution of Notch mutations in tumor cell lines

    International Nuclear Information System (INIS)

    Deregulated Notch signaling is linked to a variety of tumors and it is therefore important to learn more about the frequency and distribution of Notch mutations in a tumor context. In this report, we use data from the recently developed Cancer Cell Line Encyclopedia to assess the frequency and distribution of Notch mutations in a large panel of cancer cell lines in silico. Our results show that the mutation frequency of Notch receptor and ligand genes is at par with that for established oncogenes and higher than for a set of house-keeping genes. Mutations were found across all four Notch receptor genes, but with notable differences between protein domains, mutations were for example more prevalent in the regions encoding the LNR and PEST domains in the Notch intracellular domain. Furthermore, an in silico estimation of functional impact showed that deleterious mutations cluster to the ligand-binding and the intracellular domains of NOTCH1. For most cell line groups, the mutation frequency of Notch genes is higher than in associated primary tumors. Our results shed new light on the spectrum of Notch mutations after in vitro culturing of tumor cells. The higher mutation frequency in tumor cell lines indicates that Notch mutations are associated with a growth advantage in vitro, and thus may be considered to be driver mutations in a tumor cell line context. The online version of this article (doi:10.1186/s12885-015-1278-x) contains supplementary material, which is available to authorized users

  12. Mapping Sites of O-Glycosylation and Fringe Elongation on Drosophila Notch.

    Science.gov (United States)

    Harvey, Beth M; Rana, Nadia A; Moss, Hillary; Leonardi, Jessica; Jafar-Nejad, Hamed; Haltiwanger, Robert S

    2016-07-29

    Glycosylation of the Notch receptor is essential for its activity and serves as an important modulator of signaling. Three major forms of O-glycosylation are predicted to occur at consensus sites within the epidermal growth factor-like repeats in the extracellular domain of the receptor: O-fucosylation, O-glucosylation, and O-GlcNAcylation. We have performed comprehensive mass spectral analyses of these three types of O-glycosylation on Drosophila Notch produced in S2 cells and identified peptides containing all 22 predicted O-fucose sites, all 18 predicted O-glucose sites, and all 18 putative O-GlcNAc sites. Using semiquantitative mass spectral methods, we have evaluated the occupancy and relative amounts of glycans at each site. The majority of the O-fucose sites were modified to high stoichiometries. Upon expression of the β3-N-acetylglucosaminyltransferase Fringe with Notch, we observed varying degrees of elongation beyond O-fucose monosaccharide, indicating that Fringe preferentially modifies certain sites more than others. Rumi modified O-glucose sites to high stoichiometries, although elongation of the O-glucose was site-specific. Although the current putative consensus sequence for O-GlcNAcylation predicts 18 O-GlcNAc sites on Notch, we only observed apparent O-GlcNAc modification at five sites. In addition, we performed mass spectral analysis on endogenous Notch purified from Drosophila embryos and found that the glycosylation states were similar to those found on Notch from S2 cells. These data provide foundational information for future studies investigating the mechanisms of how O-glycosylation regulates Notch activity. PMID:27268051

  13. Hes1 potentiates T cell lymphomagenesis by up-regulating a subset of notch target genes.

    Directory of Open Access Journals (Sweden)

    Darryll D Dudley

    Full Text Available BACKGROUND: Hairy/Enhancer of Split (Hes proteins are targets of the Notch signaling pathway and make up a class of basic helix-loop-helix (bHLH proteins that function to repress transcription. Data from Hes1 deficient mice suggested that Hes1, like Notch1, is necessary for the progression of early T cell progenitors. Constitutive activation of Notch is known to cause T cell leukemia or lymphoma but whether Hes1 has any oncogenic activity is not known. METHODOLOGY/PRINCIPAL FINDINGS: We generated mice carrying a Hes1 transgene under control of the proximal promote of the lck gene. Hes1 expression led to a reduction in numbers of total thymocytes, concomitant with the increased percentage and number of immature CD8+ (ISP T cells and sustained CD25 expression in CD4+CD8+ double positive (DP thymocytes. Hes1 transgenic mice develop thymic lymphomas at about 20 weeks of age with a low penetrance. However, expression of Hes1 significantly shortens the latency of T cell lymphoma developed in Id1 transgenic mice, where the function of bHLH E proteins is inhibited. Interestingly, Hes1 increased expression of a subset of Notch target genes in pre-malignant ISP and DP thymocytes, which include Notch1, Notch3 and c-myc, thus suggesting a possible mechanism for lymphomagenesis. CONCLUSIONS/SIGNIFICANCE: We have demonstrated for the first time that Hes1 potentiates T cell lymphomagenesis, by up-regulating a subset of Notch target genes and by causing an accumulation of ISP thymocytes particularly vulnerable to oncogenic transformation.

  14. Notch ankyrin repeat domain variation influences leukemogenesis and Myc transactivation.

    Directory of Open Access Journals (Sweden)

    Jon C Aster

    Full Text Available BACKGROUND: The functional interchangeability of mammalian Notch receptors (Notch1-4 in normal and pathophysiologic contexts such as cancer is unsettled. We used complementary in vivo, cell-based and structural analyses to compare the abilities of activated Notch1-4 to support T cell development, induce T cell acute lymphoblastic leukemia/lymphoma (T-ALL, and maintain T-ALL cell growth and survival. PRINCIPAL FINDINGS: We find that the activated intracellular domains of Notch1-4 (ICN1-4 all support T cell development in mice and thymic organ culture. However, unlike ICN1-3, ICN4 fails to induce T-cell acute lymphoblastic leukemia/lymphoma (T-ALL and is unable to rescue the growth of Notch1-dependent T-ALL cell lines. The ICN4 phenotype is mimicked by weak gain-of-function forms of Notch1, suggesting that it stems from a failure to transactivate one or more critical target genes above a necessary threshold. Experiments with chimeric receptors demonstrate that the Notch ankyrin repeat domains differ in their leukemogenic potential, and that this difference correlates with activation of Myc, a direct Notch target that has an important role in Notch-associated T-ALL. CONCLUSIONS/SIGNIFICANCE: We conclude that the leukemogenic potentials of Notch receptors vary, and that this functional difference stems in part from divergence among the highly conserved ankyrin repeats, which influence the transactivation of specific target genes involved in leukemogenesis.

  15. NOTCH1基因3'-UTR段双荧光素酶报告载体的构建及其活性鉴定%Construction 3'-UTR of NOTCH1 dual luciferase recombintant vector and evaluation of its activity

    Institute of Scientific and Technical Information of China (English)

    邵新宏; 韩渊; 于游; 张才全

    2013-01-01

    目的:构建含NOTCH1基因3'-UTR段双荧光素酶报告载体,并验证其活性.方法:使用PCR方法扩增含NOTCH1基因3'-UTR区序列,插入到双酶切的双荧光素酶报告载体中;使用生物信息学方法预测可能与NOTCH1基因3'-UTR相互作用的miRNA;使用lipofectamine 2000转染试剂将重组质粒或空质粒和miR-34a inhibitor或control真核表达载体共转染HEK293T细胞,双荧光素酶检测试剂盒测定荧光素酶活性.结果:得到含NOTCH1基因3'-UTR(1 648 bp)序列的双荧光素酶报告重组质粒,并用凝胶电泳和基因测序的方法验证.NOTCH1基因3'-UTR上可能有miR-34a的调控作用靶点;用重组质粒和miR-34a inhibitor共转染的HEK293T组的荧光素酶活性比空质粒组高45%.结论:含NOTCH1基因3'-UTR双荧光素酶报告载体构建成功,miR-34a对NOTCH1基因有调控作用.%Objective:To construct the dual-luciferase recombinant vector which contain 3'-UTR of N0TCH1 gene and verify its activity. Methods:3'-UTR of NOTCH1 gene was amplified through PCR method, and was inserted in the dual luciferase reporter vector which was digested by enzyme. 3'-UTR of NOTCH1 which targeting effect miRNA was predicted by bioinformation. HEK293T cells was treated with recombinant vector or empty vector and miR-34a inhibitor or control by transfection reagent. The dual Luciferase Reporter Assay System was used to evaluate the activity of luciferase. Results:3'-UTR of NOTCH1 gene was successfully cloned into the pmiR-RB-REPORT? vector, which was vertified by Gel electrophoresis and DNA sequencing methods. 3'-UTR of N0TCH1 gene may has a binding site of miR-34a. Comparing with HEK293T cells was treated with the empty vector , the luciferase activity of HEK293T cells which was cotransfected with recombinant vector and miRNA-34a inhibitor was increased to 45%. Conclusion: 3'-UTR of N0TCH1 gene dual luciferase combintant vector was successfully constructed, preliminary evidence show that miR-34a could

  16. Numb is not a critical regulator of Notch-mediated cell fate decisions in the developing chick inner ear

    Directory of Open Access Journals (Sweden)

    Mark eEddison

    2015-03-01

    Full Text Available The Notch signalling pathway controls differentiation of hair cells and supporting cells in the vertebrate inner ear. Here, we have investigated whether Numb, a known regulator of Notch activity in Drosophila, is involved in this process in the embryonic chick. The chicken homologue of Numb is expressed throughout the otocyst at early stages of development and is concentrated at the basal pole of the cells. It is asymmetrically allocated at some cell divisions, as in Drosophila, suggesting that it could act as a determinant inherited by one of the two daughter cells and favouring adoption of a hair-cell fate. To test the implication of Numb in hair cell fate decisions and the regulation of Notch signalling, we used different methods to overexpress Numb at different stages of inner ear development. We found that sustained or late Numb overexpression does not promote hair cell differentiation, and Numb does not prevent the reception of Notch signalling. Surprisingly, none of the Numb-overexpressing cells differentiated into hair cells, suggesting that high levels of Numb protein could interfere with intracellular processes essential for hair cell survival. However when Numb was overexpressed early and more transiently during ear development, no effect on hair cell formation was seen. These results suggest that in the inner ear at least, Numb does not significantly repress Notch activity and that its asymmetric distribution in dividing precursor cells does not govern the choice between hair cell and supporting cell fates.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

  19. The loss of Hoxa5 function promotes Notch-dependent goblet cell metaplasia in lung airways

    Directory of Open Access Journals (Sweden)

    Olivier Boucherat

    2012-05-01

    Hox genes encode transcription factors controlling complex developmental processes in various organs. Little is known, however, about how HOX proteins control cell fate. Herein, we demonstrate that the goblet cell metaplasia observed in lung airways from Hoxa5−/− mice originates from the transdifferentiation of Clara cells. Reduced CC10 expression in Hoxa5−/− embryos indicates that altered cell specification occurs prior to birth. The loss of Hoxa5 function does not preclude airway repair after naphthalene exposure, but the regenerated epithelium presents goblet cell metaplasia and less CC10-positive cells, demonstrating the essential role of Hoxa5 for correct differentiation. Goblet cell metaplasia in Hoxa5−/− mice is a FOXA2-independent process. However, it is associated with increased Notch signaling activity. Consistent with these findings, expression levels of activated NOTCH1 and the effector gene HEY2 are enhanced in patients with chronic obstructive pulmonary disease. In vivo administration of a γ-secretase inhibitor attenuates goblet cell metaplasia in Hoxa5−/− mice, highlighting the contribution of Notch signaling to the phenotype and suggesting a potential therapeutic strategy to inhibit goblet cell differentiation and mucus overproduction in airway diseases. In summary, the loss of Hoxa5 function in lung mesenchyme impacts on epithelial cell fate by modulating Notch signaling.

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

    International Nuclear Information System (INIS)

    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.

  1. Blocking the NOTCH pathway can inhibit the growth of CD133-positive A549 cells and sensitize to chemotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Juntao; Mao, Zhangfan; Huang, Jie; Xie, Songping; Liu, Tianshu; Mao, Zhifu, E-mail: 48151660@qq.com

    2014-02-21

    Highlights: • Notch signaling pathway members are expressed lower levels in CD133+ cells. • CD133+ cells are not as sensitive as CD133− cells to chemotherapy. • GSI could inhibit the growth of both CD133+ and CD133− cells. • Blockade of Notch signaling pathway enhanced the effect of chemotherapy with CDDP. • DAPT/CDDP co-therapy caused G2/M arrest and elimination in CD133+ cells. - Abstract: Cancer stem cells (CSCs) are believed to play an important role in tumor growth and recurrence. These cells exhibit self-renewal and proliferation properties. CSCs also exhibit significant drug resistance compared with normal tumor cells. Finding new treatments that target CSCs could significantly enhance the effect of chemotherapy and improve patient survival. Notch signaling is known to regulate the development of the lungs by controlling the cell-fate determination of normal stem cells. In this study, we isolated CSCs from the human lung adenocarcinoma cell line A549. CD133 was used as a stem cell marker for fluorescence-activated cell sorting (FACS). We compared the expression of Notch signaling in both CD133+ and CD133− cells and blocked Notch signaling using the γ-secretase inhibitor DAPT (GSI-IX). The effect of combining GSI and cisplatin (CDDP) was also examined in these two types of cells. We observed that both CD133+ and CD133− cells proliferated at similar rates, but the cells exhibited distinctive differences in cell cycle progression. Few CD133+ cells were observed in the G{sub 2}/M phase, and there were half as many cells in S phase compared with the CD133− cells. Furthermore, CD133+ cells exhibited significant resistance to chemotherapy when treated with CDDP. The expression of Notch signaling pathway members, such as Notch1, Notch2 and Hes1, was lower in CD133+ cells. GSI slightly inhibited the proliferation of both cell types and exhibited little effect on the cell cycle. The inhibitory effects of DPP on these two types of cells were

  2. Blocking the NOTCH pathway can inhibit the growth of CD133-positive A549 cells and sensitize to chemotherapy

    International Nuclear Information System (INIS)

    Highlights: • Notch signaling pathway members are expressed lower levels in CD133+ cells. • CD133+ cells are not as sensitive as CD133− cells to chemotherapy. • GSI could inhibit the growth of both CD133+ and CD133− cells. • Blockade of Notch signaling pathway enhanced the effect of chemotherapy with CDDP. • DAPT/CDDP co-therapy caused G2/M arrest and elimination in CD133+ cells. - Abstract: Cancer stem cells (CSCs) are believed to play an important role in tumor growth and recurrence. These cells exhibit self-renewal and proliferation properties. CSCs also exhibit significant drug resistance compared with normal tumor cells. Finding new treatments that target CSCs could significantly enhance the effect of chemotherapy and improve patient survival. Notch signaling is known to regulate the development of the lungs by controlling the cell-fate determination of normal stem cells. In this study, we isolated CSCs from the human lung adenocarcinoma cell line A549. CD133 was used as a stem cell marker for fluorescence-activated cell sorting (FACS). We compared the expression of Notch signaling in both CD133+ and CD133− cells and blocked Notch signaling using the γ-secretase inhibitor DAPT (GSI-IX). The effect of combining GSI and cisplatin (CDDP) was also examined in these two types of cells. We observed that both CD133+ and CD133− cells proliferated at similar rates, but the cells exhibited distinctive differences in cell cycle progression. Few CD133+ cells were observed in the G2/M phase, and there were half as many cells in S phase compared with the CD133− cells. Furthermore, CD133+ cells exhibited significant resistance to chemotherapy when treated with CDDP. The expression of Notch signaling pathway members, such as Notch1, Notch2 and Hes1, was lower in CD133+ cells. GSI slightly inhibited the proliferation of both cell types and exhibited little effect on the cell cycle. The inhibitory effects of DPP on these two types of cells were enhanced

  3. Notch 1 Receptor, Delta 1 Ligand and HES 1 Transcription Factor are Expressed in the Lining Epithelium of Periapical Cysts (Preliminary Study)

    Science.gov (United States)

    Meliou, E; Kerezoudis, NP; Tosios, KI; Kiaris, H

    2010-01-01

    Periapical cyst is a chronic inflammatory disorder of periradicular tissues. The precise pathological mechanisms involved in periapical cyst enlargement remain unclear. Notch signaling is an evolutionarily conserved pathway with a regulatory role in cell fate decisions during development and in carcinogenesis. To date, there are no published data available on the expression of Notch signaling components in periapical cysts or any other jaw cyst. In this immunohistochemical study we have examined the expression of the receptor Notch 1, the ligand Delta 1 and the transcription factor HES 1 in the epithelium of well defined periapical cysts. Immunostaining reaction of Notch 1, Delta 1 and HES 1 was observed in the cytoplasm and/or the cytoplasmic membrane and occasionally in the nucleus in the majority of epithelial cells of all periapical cysts. The present observations indicate that Notch pathway is active in the epithelium of periapical cysts. It can be speculated that activation of epithelial cells of periapical cysts is associated with activation of Notch pathway and imply involvement of this pathway in periapical cyst growth and expansion. PMID:21116324

  4. Notch-2在大鼠牙髓炎中的时空分布及其意义%Time-sequenced alteration of immunolocalization and significance of Notch-2 expression in rat pulpitis

    Institute of Scientific and Technical Information of China (English)

    马亮; 张亚庆; 王胜朝; 黄贞贞

    2009-01-01

    mesenchyme cells and subodontoblastic layer cells and was absent from odontoblasts. Notch-2 immunoreactivity was completely absent in intact rat dental pulp. Conclusion: Notch-2 is strikingly up-regulated in dental pulp mesenchyme cells in the early days after dental injury and then shows progressively up-regulation in odontoblasts. Properly regulated activation of Notch signaling pathway is important for controlling cell fate and maintaining the correct balance among cell proliferation, differentiation and apoptosis during dental pulp repair process.

  5. Niclosamide inhibits colon cancer progression through downregulation of the Notch pathway and upregulation of the tumor suppressor miR-200 family.

    Science.gov (United States)

    Suliman, Mohammed A; Zhang, Zhenxing; Na, Heya; Ribeiro, Ailton L L; Zhang, Yu; Niang, Bachir; Hamid, Abdu Salim; Zhang, Hua; Xu, Lijie; Zuo, Yunfei

    2016-09-01

    Colorectal cancer (CRC) is among the most frequent causes of cancer-related deaths worldwide. Thus, there is a need for the development of new therapeutic approaches for the treatment of CRC. Accumulating evidence has revealed that niclosamide, an anthelminthic drug, exerts antitumor activity in several types of cancer, including colon cancer. However, the underlying molecular mechanisms responsible for the effects of this drug remain elusive. Previous studies have shown that the aberrant Notch signaling pathway contributes to the carcinogenesis of colon cancer. Herein, we examined the effects of niclosamide on the growth, migration and apoptosis of colon cancer cells, and the role of the Notch signaling pathway. By performing MTT, wound-healing and Transwell migration assays, we observed that niclosamide suppressed the growth and migration of colon cancer cells, and flow cytometry demonstrated that cell apoptosis was induced. This was associated with the decreased protein expression of Notch1, Notch2, Notch3 and Hey1, and the increased expression of the tumor suppressor microRNA (miR or miRNA)‑200 family members (miR‑200a, miR-200b, miR-200c, miR-141 and miR-429) that are typically downregulated in colon cancer. Collectively, these findings demonstrate that niclosamide potentially inhibits the progression of colon cancer by downregulating Notch signaling and by upregulating the miR-200 family members. PMID:27460529

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2015-01-01

    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, vgBE-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 vgBE-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 (DERact) or the MAPK (rlSEM) 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. PMID:26702412

  8. Notch 1 as a potential therapeutic target in cutaneous T-cell lymphoma

    DEFF Research Database (Denmark)

    Kamstrup, Maria Rørbæk; Gjerdrum, Lise Mette Rahbek; Biskup, Edyta Urszula;

    2010-01-01

    Deregulation of Notch signaling has been linked to the development of T-cell leukemias and several solid malignancies. Yet, it is unknown whether Notch signalling is involved in the pathogenesis of mycosis fungoides and Sezary syndrome, the most common subtypes of cutaneous T cell lymphoma....... By immunohistochemistry of 40 biopsies taken from skin lesions of mycosis fungoides and Sezary syndrome we demonstrated prominent expression of Notch1 on tumor cells, especially in the more advanced stages. The gamma-secretase inhibitor I blocked Notch signaling and potently induced apoptosis in cell lines derived from...... mycosis fungoides (MyLa) and Sezary syndrome (SeAx, HuT-78)and in primary leukemic Sézary cells. Specific downregulation of Notch1 (but not Notch2 and Notch3) by siRNA induced apoptosis in SeAx. The mechanism of apoptosis involved the inhibition of NF-kappaB, which is the most important prosurvival...

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

    Directory of Open Access Journals (Sweden)

    Chiara Lambertini

    Full Text Available 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.

  10. Rescue of Notch signaling in cells incapable of GDP-l-fucose synthesis by gap junction transfer of GDP-l-fucose in Drosophila

    OpenAIRE

    Ayukawa, Tomonori; Matsumoto, Kenjiroo; Ishikawa, Hiroyuki O.; Ishio, Akira; Yamakawa, Tomoko; Aoyama, Naoki; Suzuki, Takuya; Matsuno, Kenji

    2012-01-01

    Notch (N) is a transmembrane receptor that mediates cell–cell interactions to determine many cell-fate decisions. N contains EGF-like repeats, many of which have an O-fucose glycan modification that regulates N-ligand binding. This modification requires GDP-l-fucose as a donor of fucose. The GDP-l-fucose biosynthetic pathways are well understood, including the de novo pathway, which depends on GDP-mannose 4,6 dehydratase (Gmd) and GDP-4-keto-6-deoxy-d-mannose 3,5-epimerase/4-reductase (Gmer)....

  11. Clinical impact of de-regulated Notch-1 and Notch-3 in the development and progression of HPV-associated different histological subtypes of precancerous and cancerous lesions of human uterine cervix.

    Directory of Open Access Journals (Sweden)

    Richa Tripathi

    Full Text Available BACKGROUND: Cervical cancer is the leading cause of cancer related deaths among women in India. Limited reports are available for Notch-1 and Notch-3 protein in cervical carcinoma, which play crucial role in cell proliferation, differentiation, and apoptosis. METHODS: This study was designed to evaluate the role of Notch-1 and Notch-3 with context to HPV infection in cervical carcinoma. A total of 168 tissue biopsy samples comprising of tumor specimens (n = 98, precancer (n = 30 and non-neoplastic cervical tissues (n = 40 were screened for HPV infection by PCR and expression of Notch-1 and Notch-3 protein by Immunohistochemistry and Immunoblotting. RESULTS: 80% (24/30 were found to be positive for HPV in precancer and 86.7% (85/98 in cancer patients. Notch-1 expression of precancer and cancer cases was found to be significantly down-regulated with severity of disease in nuclear (3.43±0.29; 2.04±0.19, p = 0.0001, p = 0.0001 and cytoplasm (3.07±0.29; 2.29±0.17, p = 0.0001, p = 0.0001 obtained from different stages as compared to normal cervix tissue (5.40±0.19, 4.97±0.15; p<0.001; p<0.001. However, Notch-3 expression of above cases was significantly up-regulated with severity of disease and showed intense nuclear (4.17±0.39; 4.74±0.18, p = 0.0001, p = 0.0001 and cytoplasm (3.67±0.36; 4.48±0.18, p = 0.0001, p = 0.0001 of different stages as compared to normal cervix tissue (0.95±0.20, 0.70±0.20; p<0.001; p<0.001 respectively. CONCLUSIONS: These findings suggest that Notch-1 and Notch-3 may play an important role with synergistic effect of HPV in regulating development and proliferation of cervical cancer through the deregulation of Notch signalling. This study also shows the clinical utility of both proteins which may be used as predictable biomarkers in diagnosing different histological sub-types of HPV associated cervical cancer. Nevertheless, abnormal activation of this pathway may provide

  12. The effect of up-regulated Notch signaling on the proliferation of osteoclasts by hBMSCs%人骨髓间充质干细胞中 Notch 信号上调对破骨细胞增殖的调控

    Institute of Scientific and Technical Information of China (English)

    魏铂沅; 杨柳; 高博; 史淇月; 黄强; 韩跃虎; 罗卓荆; 刘建

    2014-01-01

    目的:通过研究Notch信号上调的人骨髓间充质干细胞( human Bone Marrow Mesenchymal Stem Cells , hBMSCs )对破骨细胞增殖调控的机制,探讨Notch信号在成骨-破骨偶联中的作用。方法用装载Notch信号胞内域NICD1的慢病毒载体(Lentivirus, Lv)转染hBMSCs,收集其分泌的条件培养液(Conditioned Medium,CM)。培养前破骨细胞系RAW264.7,模拟共培养环境。定量RT-PCR和ELISA测定转染前后hBMSCs表达和分泌的M-CSF的情况。 cck-8和单板克隆试验测定RAW264.7的增殖情况。结果转染慢病毒后,hBMSCs表达和分泌的M-CSF均有所上调(分别为P<0.01和 P<0.05);CCK-8和单板克隆试验的结果显示hBMSCs分泌的CM使RAW264.7的细胞数量增加(均为P<0.01)。结论 Notch信号上调的hBMSCs可以通过影响M-CSF的表达和分泌,作用于破骨前体细胞,促进其增殖。%Objective By investigating the mechanism of up-regulated Notch signaling in the proliferation of osteoclasts in human bone marrow mesenchymal stem cells ( hBMSCs ) , to explore the effect of Notch signaling on the coupling of osteoblasts and osteoclasts.Methods hBMSCs were transfected with the Lentivirus vector ( Lv ) , which loaded with the Notch intracellular domain 1(NICD1).And the conditioned medium (CM) was collected.The pre-osteoclast cell line, RAW264.7, was cultured in the CM, which could mimic the co-culture environment.The expression and secretion of M-CSF in the hBMSCs before and after the transfection were detected using quantitative RT-PCR and ELISA method.The proliferation of RAW264.7 cells was detected using CCK-8 and colony-forming unit assays.Results After the transfection of Lv, both the expression and secretion of M-CSF in the hBMSCs increased ( P <0.01; P<0.05 ) .Furthermore, the number of RAW 264.7 cells cultured in the CM secreted by the hBMSCs also increased, according to the detection using CCK-8 and colony-forming unit assays ( P<0

  13. Notch is required in adult Drosophila sensory neurons for morphological and functional plasticity of the olfactory circuit.

    Directory of Open Access Journals (Sweden)

    Simon Kidd

    2015-05-01

    Full Text Available Olfactory receptor neurons (ORNs convey odor information to the central brain, but like other sensory neurons were thought to play a passive role in memory formation and storage. Here we show that Notch, part of an evolutionarily conserved intercellular signaling pathway, is required in adult Drosophila ORNs for the structural and functional plasticity of olfactory glomeruli that is induced by chronic odor exposure. Specifically, we show that Notch activity in ORNs is necessary for the odor specific increase in the volume of glomeruli that occurs as a consequence of prolonged odor exposure. Calcium imaging experiments indicate that Notch in ORNs is also required for the chronic odor induced changes in the physiology of ORNs and the ensuing changes in the physiological response of their second order projection neurons (PNs. We further show that Notch in ORNs acts by both canonical cleavage-dependent and non-canonical cleavage-independent pathways. The Notch ligand Delta (Dl in PNs switches the balance between the pathways. These data define a circuit whereby, in conjunction with odor, N activity in the periphery regulates the activity of neurons in the central brain and Dl in the central brain regulates N activity in the periphery. Our work highlights the importance of experience dependent plasticity at the first olfactory synapse.

  14. Notch receptor expression in neurogenic regions of the adult zebrafish brain.

    Directory of Open Access Journals (Sweden)

    Vanessa de Oliveira-Carlos

    Full Text Available The adult zebrash brain has a remarkable constitutive neurogenic capacity. The regulation and maintenance of its adult neurogenic niches are poorly understood. In mammals, Notch signaling is involved in stem cell maintenance both in embryonic and adult CNS. To better understand how Notch signaling is involved in stem cell maintenance during adult neurogenesis in zebrafish we analysed Notch receptor expression in five neurogenic zones of the adult zebrafish brain. Combining proliferation and glial markers we identified several subsets of Notch receptor expressing cells. We found that 90 [Formula: see text] of proliferating radial glia express notch1a, notch1b and notch3. In contrast, the proliferating non-glial populations of the dorsal telencephalon and hypothalamus rarely express notch3 and about half express notch1a/1b. In the non-proliferating radial glia notch3 is the predominant receptor throughout the brain. In the ventral telencephalon and in the mitotic area of the optic tectum, where cells have neuroepithelial properties, notch1a/1b/3 are expressed in most proliferating cells. However, in the cerebellar niche, although progenitors also have neuroepithelial properties, only notch1a/1b are expressed in a high number of PCNA [Formula: see text] cells. In this region notch3 expression is mostly in Bergmann glia and at low levels in few PCNA [Formula: see text] cells. Additionally, we found that in the proliferation zone of the ventral telencephalon, Notch receptors display an apical high to basal low gradient of expression. Notch receptors are also expressed in subpopulations of oligodendrocytes, neurons and endothelial cells. We suggest that the partial regional heterogeneity observed for Notch expression in progenitor cells might be related to the cellular diversity present in each of these neurogenic niches.

  15. Serum From Advanced Heart Failure Patients Promotes Angiogenic Sprouting and Affects the Notch Pathway in Human Endothelial Cells.

    Science.gov (United States)

    Pannella, Micaela; Caliceti, Cristiana; Fortini, Francesca; Aquila, Giorgio; Vieceli Dalla Sega, Francesco; Pannuti, Antonio; Fortini, Cinzia; Morelli, Marco Bruno; Fucili, Alessandro; Francolini, Gloria; Voltan, Rebecca; Secchiero, Paola; Dinelli, Giovanni; Leoncini, Emanuela; Ferracin, Manuela; Hrelia, Silvana; Miele, Lucio; Rizzo, Paola

    2016-12-01

    It is unknown whether components present in heart failure (HF) patients' serum provide an angiogenic stimulus. We sought to determine whether serum from HF patients affects angiogenesis and its major modulator, the Notch pathway, in human umbilical vein endothelial cells (HUVECs). In cells treated with serum from healthy subjects or from patients at different HF stage we determined: (1) Sprouting angiogenesis, by measuring cells network (closed tubes) in collagen gel. (2) Protein levels of Notch receptors 1, 2, 4, and ligands Jagged1, Delta-like4. We found a higher number of closed tubes in HUVECs treated with advanced HF patients serum in comparison with cells treated with serum from mild HF patients or controls. Furthermore, as indicated by the reduction of the active form of Notch4 (N4IC) and of Jagged1, advanced HF patients serum inhibited Notch signalling in HUVECs in comparison with mild HF patients' serum and controls. The circulating levels of NT-proBNP (N-terminal of the pro-hormone brain natriuretic peptide), a marker for the detection and evalutation of HF, were positively correlated with the number of closed tubes (r = 0.485) and negatively with Notch4IC and Jagged1 levels in sera-treated cells (r = -0.526 and r = -0.604, respectively). In conclusion, we found that sera from advanced HF patients promote sprouting angiogenesis and dysregulate Notch signaling in HUVECs. Our study provides in vitro evidence of an angiogenic stimulus arising during HF progression and suggests a role for the Notch pathway in it. J. Cell. Physiol. 231: 2700-2710, 2016. © 2016 Wiley Periodicals, Inc. PMID:26987674

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

    Science.gov (United States)

    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.

  17. Notch ligand Delta-like 1 promotes the metastasis of melanoma by enhancing tumor adhesion

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, J.P. [Department of Orthopedic Surgery, Tangdu Hospital, The Fourth Military Medical University, Xi' an (China); Li, N. [Department of Oncology, Tangdu Hospital, The Fourth Military Medical University, Xi' an (China); Bai, W.Z.; Qiu, X.C.; Ma, B.A.; Zhou, Y.; Fan, Q.Y.; Shan, L.Q. [Department of Orthopedic Surgery, Tangdu Hospital, The Fourth Military Medical University, Xi' an (China)

    2014-03-28

    Notch signaling plays a vital role in tumorigenicity and tumor progression by regulating proliferation, invasion, and the tumor microenvironment. Previous research by our group indicated that Notch ligand Delta-like 1 (Dll1) is involved in angiogenesis in melanoma, and we noticed that it took a longer time to trypsinize Dll1-expressing B16 melanoma cells than the control cells. In this article, we extended our study to investigate the effects of Dll1 on tumor cell adhesion and metastasis. Dll1 overexpression activated Notch signaling in B16 tumor cells and significantly enhanced the adhering capacity of B16 tumor cells both in vitro and in vivo. B16-Dll1 cells also had a higher metastatic potential than their counterpart in the mouse model of lung metastasis. Along with increased Dll1 expression, N-cadherin, but not E-cadherin, was upregulated in B16-Dll1 cells. These data suggested that Notch ligand Dll1 may enhance the adhesion and metastasis of melanoma cells by upregulation of N-cadherin.

  18. The relevance of PTEN-AKT in relation to NOTCH1-directed treatment strategies in T-cell acute lymphoblastic leukemia.

    Science.gov (United States)

    Mendes, Rui D; Canté-Barrett, Kirsten; Pieters, Rob; Meijerink, Jules P P

    2016-09-01

    The tumor suppressor phosphatase and tensin homolog (PTEN) negatively regulates phosphatidylinositol 3-kinase (PI3K)-AKT signaling and is often inactivated by mutations (including deletions) in a variety of cancer types, including T-cell acute lymphoblastic leukemia. Here we review mutation-associated mechanisms that inactivate PTEN together with other molecular mechanisms that activate AKT and contribute to T-cell leukemogenesis. In addition, we discuss how Pten mutations in mouse models affect the efficacy of gamma-secretase inhibitors to block NOTCH1 signaling through activation of AKT. Based on these models and on observations in primary diagnostic samples from patients with T-cell acute lymphoblastic leukemia, we speculate that PTEN-deficient cells employ an intrinsic homeostatic mechanism in which PI3K-AKT signaling is dampened over time. As a result of this reduced PI3K-AKT signaling, the level of AKT activation may be insufficient to compensate for NOTCH1 inhibition, resulting in responsiveness to gamma-secretase inhibitors. On the other hand, de novo acquired PTEN-inactivating events in NOTCH1-dependent leukemia could result in temporary, strong activation of PI3K-AKT signaling, increased glycolysis and glutaminolysis, and consequently gamma-secretase inhibitor resistance. Due to the central role of PTEN-AKT signaling and in the resistance to NOTCH1 inhibition, AKT inhibitors may be a promising addition to current treatment protocols for T-cell acute lymphoblastic leukemia. PMID:27582570

  19. Retraction: "Down-regulation of Notch-1 and Jagged-1 inhibits prostate cancer cell growth, migration and invasion, and induces apoptosis via inactivation of Akt, mTOR, and NF-κB signaling pathways" by Wang et al.

    Science.gov (United States)

    2016-08-01

    The above article, published online on January 5, 2010 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the journal Editor in Chief, Gary S. Stein, and Wiley Periodicals, Inc. The retraction has been agreed following an investigation from Wayne State University involving the first author and the corresponding author that found Figure 5A to be inappropriately manipulated. REFERENCE Wang Z, Li Y, Banerjee S, Kong D, Ahmad A, Nogueira V, Hay N, Sarkar FH. 2010. Down-regulation of Notch-1 and Jagged-1 inhibits prostate cancer cell growth, migration and invasion, and induces apoptosis via inactivation of Akt, mTOR, and NF-κB signaling pathways. J Cell Biochem 109:726-736; doi: 10.1002/jcb.22451.

  20. Retraction: "Down-regulation of Notch-1 and Jagged-1 inhibits prostate cancer cell growth, migration and invasion, and induces apoptosis via inactivation of Akt, mTOR, and NF-κB signaling pathways" by Wang et al.

    Science.gov (United States)

    2016-08-01

    The above article, published online on January 5, 2010 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the journal Editor in Chief, Gary S. Stein, and Wiley Periodicals, Inc. The retraction has been agreed following an investigation from Wayne State University involving the first author and the corresponding author that found Figure 5A to be inappropriately manipulated. REFERENCE Wang Z, Li Y, Banerjee S, Kong D, Ahmad A, Nogueira V, Hay N, Sarkar FH. 2010. Down-regulation of Notch-1 and Jagged-1 inhibits prostate cancer cell growth, migration and invasion, and induces apoptosis via inactivation of Akt, mTOR, and NF-κB signaling pathways. J Cell Biochem 109:726-736; doi: 10.1002/jcb.22451. PMID:27301887

  1. A Notch-dependent molecular circuitry initiates pancreatic endocrine and ductal cell differentiation

    DEFF Research Database (Denmark)

    Shih, Hung Ping; Kopp, Janel L; Sandhu, Manbir;

    2012-01-01

    differentiation necessitates subsequent Sox9 downregulation and evasion from Notch activity via cell-autonomous repression of Sox9 by Ngn3. If high Notch levels are maintained, endocrine progenitors retain Sox9 and undergo ductal fate conversion. Taken together, our findings establish a novel role for Notch in...

  2. Notch1调控Srcasm在人食管鳞状细胞癌TE1细胞株中的表达%Notch1 up-regulates srcasm expression in human esophageal squamous cell carcinoma TE1 cell line

    Institute of Scientific and Technical Information of China (English)

    齐宇; 李鑫

    2014-01-01

    Objective To study the Src-activating and signaling molecule (Srcasm) expression regulated by Notchl in human esophageal squamous cell carcinoma (ESCC) TE1 cell line.Methods We transfected pcDNA3.1-Srcasm plasmid DNA (2 μg),pcDNA3.1-Srcasm plasmid NDA (2 μg),double (pcDNA3.1-Notch1 plasmid DNA 1 μg and pcDNA3.1-Srcasm plasmid DNA 1 μg) and mock (2 μg) into TE1 cells and examined Notch1/Srcasm expression by using Western blotting.Results Notch1 increased the Srcasm protein expression in TE1 cells.Conclusion Notch1 may act as a positive regulator of Fyn in human ESCC,and play an important role in human ESCC progress.%目的 探讨人食管鳞状细胞癌中Notch1参与调节人食管鳞状细胞癌TE1细胞株中Srcasm负调控Src家族酪氨酸激酶Fyn的机制.方法 分别转染pcDNA3.1-Notch1质粒DNA(2 μg)、pcDNA3.1-Srcasm质粒DNA(2μg)、Double(pcDNA3.1-Notch1质粒DNA 1μg和pcDNA3.1-Srcasm质粒DNA 1 μg)、pcDNA3.1空载体(2μg)至人食管鳞状细胞癌TE1细胞株中,观察Notch1对Srcasm表达的影响.结果 pcDNA3.1-Notch1质粒DNA的转染,原来低表达Srcasm的TE1细胞株中,Srcasm蛋白的表达明显增高.结论 人食管鳞状细胞癌TE1细胞株中Notch1可能是Srcasm的上游信号分子.

  3. Involvement of Notch1 inhibition in serum-stimulated glia and oligodendrocyte differentiation from human mesenchymal stem cells

    Directory of Open Access Journals (Sweden)

    Yi-Jang Lee

    2010-11-01

    Full Text Available Yi-Jang Lee1, Shih-Chieh Hung2–5, Mien-Sheng Chu41Department of Biomedical Imaging and Radiological Sciences, 2Institute of Clinical Medicine, 3Institute of Pharmacology, Faculty of Medicine, National Yang-Ming University, Taipei, Taiwan; 4Stem Cell Laboratory, Department of Medical Research and Education, 5Department of Orthopedics, Taipei Veterans General Hospital, Taipei 112, TaiwanAbstract: The use of in vitro oligodendrocyte differentiation for transplantation of stem cells to treat demyelinating diseases is an important consideration. In this study, we investigated the effects of serum on glia and oligodendrocyte differentiation from human mesenchymal stem cells (KP-hMSCs. We found that serum deprivation resulted in a reversible downregulation of glial- and oligodendrocyte-specific markers. Serum stimulated expression of oligodendrocyte markers, such as galactocerebroside, as well as Notch1 and JAK1 transcripts. Inhibition of Notch1 activation by the Notch inhibitor, MG132, led to enhanced expression of a serum-stimulated oligodendrocyte marker. This marker was undetectable in serum-deprived KP-hMSCs treated with MG132, suggesting that inhibition of Notch1 function is additive to serum-stimulated oligodendrocyte differentiation. Furthermore, a dominant-negative mutant RBP-J protein also inhibited Notch1 function and led to upregulation of oligodendrocyte-specific markers. Our results demonstrate that serum-stimulated oligodendrocyte differentiation is enhanced by the inhibition of Notch1-associated functions.Keywords: mesenchymal stem cells, glia and oligodendrocyte differentiation, Notch1 signaling, serum deprivation

  4. TEMPORAL EXPRESSION OF NOTCH RECEPTORS DURING LUNG DEVELOPMENT IN RAT

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qian-shen; CHANG Li-wen; LIU Han-chu; RONG Zhi-hu; CHEN Hong-bing

    2005-01-01

    Objective To investigate the temporal expression of Notch receptors in developing lungs of rats and to explore the regulating role of Notch in lung development. Methods We studied the expression of Notch1,2,3 isforms in embryonic days 18,20,21 and postnatal days 1,4,7,14, 21 rat lungs. Six rats of each group were used to assess lung histologic changes by HE staining and expression of Notch in lungs by immunohistochemistry. Total RNA was extracted by Trizol reagent from the frozen lung tissues. mRNA levels of Notch were measured by reverse transcription polymerase chain reaction (RT-PCR). Results It is showed that Notch1-3 mainly localized in the airway surface epithelium、alveolar epithelium during the psdueoglandular stage, and reached the peaks at canalicular period. The expression patterns of Notch1-3 were changed with the fetal age. Conclusion These results support multiple roles for Notch1,2,and 3 receptor activation during lung development, probably not only modulating the process of branching morphogenesis but also involved in determining the cell differentiation fate in fetal alveolar epithelium.

  5. Rescue of Notch signaling in cells incapable of GDP-L-fucose synthesis by gap junction transfer of GDP-L-fucose in Drosophila.

    Science.gov (United States)

    Ayukawa, Tomonori; Matsumoto, Kenjiroo; Ishikawa, Hiroyuki O; Ishio, Akira; Yamakawa, Tomoko; Aoyama, Naoki; Suzuki, Takuya; Matsuno, Kenji

    2012-09-18

    Notch (N) is a transmembrane receptor that mediates cell-cell interactions to determine many cell-fate decisions. N contains EGF-like repeats, many of which have an O-fucose glycan modification that regulates N-ligand binding. This modification requires GDP-L-fucose as a donor of fucose. The GDP-L-fucose biosynthetic pathways are well understood, including the de novo pathway, which depends on GDP-mannose 4,6 dehydratase (Gmd) and GDP-4-keto-6-deoxy-D-mannose 3,5-epimerase/4-reductase (Gmer). However, the potential for intercellularly supplied GDP-L-fucose and the molecular basis of such transportation have not been explored in depth. To address these points, we studied the genetic effects of mutating Gmd and Gmer on fucose modifications in Drosophila. We found that these mutants functioned cell-nonautonomously, and that GDP-L-fucose was supplied intercellularly through gap junctions composed of Innexin-2. GDP-L-fucose was not supplied through body fluids from different isolated organs, indicating that the intercellular distribution of GDP-L-fucose is restricted within a given organ. Moreover, the gap junction-mediated supply of GDP-L-fucose was sufficient to support the fucosylation of N-glycans and the O-fucosylation of the N EGF-like repeats. Our results indicate that intercellular delivery is a metabolic pathway for nucleotide sugars in live animals under certain circumstances.

  6. Loss of PTB or negative regulation of Notch mRNA reveals distinct zones of Notch and actin protein accumulation in Drosophila embryo.

    Directory of Open Access Journals (Sweden)

    Cedric S Wesley

    Full Text Available Polypyrimidine Tract Binding (PTB protein is a regulator of mRNA processing and translation. Genetic screens and studies of wing and bristle development during the post-embryonic stages of Drosophila suggest that it is a negative regulator of the Notch pathway. How PTB regulates the Notch pathway is unknown. Our studies of Drosophila embryogenesis indicate that (1 the Notch mRNA is a potential target of PTB, (2 PTB and Notch functions in the dorso-lateral regions of the Drosophila embryo are linked to actin regulation but not their functions in the ventral region, and (3 the actin-related Notch activity in the dorso-lateral regions might require a Notch activity at or near the cell surface that is different from the nuclear Notch activity involved in cell fate specification in the ventral region. These data raise the possibility that the Drosophila embryo is divided into zones of different PTB and Notch activities based on whether or not they are linked to actin regulation. They also provide clues to the almost forgotten role of Notch in cell adhesion and reveal a role for the Notch pathway in cell fusions.

  7. Acupuncture inhibits Notch1 and Hes1 protein expression in the basal ganglia of rats with cerebral hemorrhage

    Directory of Open Access Journals (Sweden)

    Wei Zou

    2015-01-01

    Full Text Available Notch pathway activation maintains neural stem cells in a proliferating state and increases nerve repair capacity. To date, studies have rarely focused on changes or damage to signal transduction pathways during cerebral hemorrhage. Here, we examined the effect of acupuncture in a rat model of cerebral hemorrhage. We examined four groups: in the control group, rats received no treatment. In the model group, cerebral hemorrhage models were established by infusing non-heparinized blood into the brain. In the acupuncture group, modeled rats had Baihui (DU20 and Qubin (GB7 acupoints treated once a day for 30 minutes. In the DAPT group, modeled rats had 0.15 μg/mL DAPT solution (10 mL infused into the brain. Immunohistochemistry and western blot results showed that acupuncture effectively inhibits Notch1 and Hes1 protein expression in rat basal ganglia. These inhibitory effects were identical to DAPT, a Notch signaling pathway inhibitor. Our results suggest that acupuncture has a neuroprotective effect on cerebral hemorrhage by inhibiting Notch-Hes signaling pathway transduction in rat basal ganglia after cerebral hemorrhage.

  8. Enhanced multistatic active sonar signal processing.

    Science.gov (United States)

    Zhao, Kexin; Liang, Junli; Karlsson, Johan; Li, Jian

    2013-07-01

    Multistatic active sonar systems involve the transmission and reception of multiple probing sequences and can achieve significantly enhanced performance of target detection and localization through exploiting spatial diversity. This paper mainly focuses on two signal processing aspects of such systems, namely, enhanced range-Doppler imaging and improved target parameter estimation. The main contributions of this paper are (1) a hybrid dense-sparse method is proposed to generate range-Doppler images with both low sidelobe levels and high accuracy; (2) a generalized K-Means clustering (GKC) method for target association is developed to associate the range measurements from different transmitter-receiver pairs, which is actually a range fitting procedure; (3) the extended invariance principle-based weighted least-squares method is developed for accurate target position and velocity estimation. The effectiveness of the proposed multistatic active sonar signal processing techniques is verified using numerical examples.

  9. Lung carcinoma signaling pathways activated by smoking

    Institute of Scientific and Technical Information of China (English)

    Jing Wen; Jian-Hua Fu; Wei Zhang; Ming Guo

    2011-01-01

    Lung cancer is the leading cause of cancer death in men and women worldwide, with over a million deaths annually. Tobacco smoke is the major etiologic risk factor for lung cancer in current or previous smokers and has been strongly related to certain types of lung cancer, such as small cell lung carcinoma and squamous cell lung carcinoma. In recent years, there has been an increased incidence of lung adenocarcinoma. This change is strongly associated with changes in smoking behavior and cigarette design. Carcinogens present in tobacco products and their intermediate metabolites can activate multiple signaling pathways that contribute to lung cancer carcinogenesis. In this review, we summarize the smoking-activated signaling pathways involved in lung cancer.

  10. NOTCH FILTER USING SIMULATED INDUCTOR

    Directory of Open Access Journals (Sweden)

    D.SUSAN,

    2011-06-01

    Full Text Available The design of analog filters at low frequencies is not possible because the size of inductors becomes very large. In such cases, the simulated inductors using operational amplifiers are used. This paper deals with the implementation of notch filter using band pass filter which uses simulated inductor where the direct implementation of notch filter using simulated inductor is not possible because of floating inductor. The design of notch filter and the simulation done in PSPICE is presented.

  11. Notch and Hedgehog in the thymus/parathyroid common primordium: Crosstalk in organ formation.

    Science.gov (United States)

    Figueiredo, Marta; Silva, Joana Clara; Santos, Ana Sofia; Proa, Vitor; Alcobia, Isabel; Zilhão, Rita; Cidadão, António; Neves, Hélia

    2016-10-15

    The avian thymus and parathyroids (T/PT) common primordium derives from the endoderm of the third and fourth pharyngeal pouches (3/4PP). The molecular mechanisms that govern T/PT development are not fully understood. Here we study the effects of Notch and Hedgehog (Hh) signalling modulation during common primordium development using in vitro, in vivo and in ovo approaches. The impairment of Notch activity reduced Foxn1/thymus-fated and Gcm2/Pth/parathyroid-fated domains in the 3/4PP and further compromised the development of the parathyroid glands. When Hh signalling was abolished, we observed a reduction in the Gata3/Gcm2- and Lfng-expression domains at the median/anterior and median/posterior territories of the pouches, respectively. In contrast, the Foxn1 expression-domain at the dorsal tip of the pouches expanded ventrally into the Lfng-expression domain. This study offers novel evidence on the role of Notch signalling in T/PT common primordium development, in an Hh-dependent manner. PMID:27544844

  12. A Compact Printed Quadruple Band-Notched UWB Antenna

    Directory of Open Access Journals (Sweden)

    Xiaoyin Li

    2013-01-01

    Full Text Available A novel compact coplanar waveguide- (CPW- fed ultrawideband (UWB printed planar volcano-smoke antenna (PVSA with four band-notches for various wireless applications is proposed and demonstrated. The low-profile antenna consists of a C-shaped parasitic strip to generate a notched band at 8.01~8.55 GHz for the ITU band, two C-shaped slots, and an inverted U-shaped slot etched in the radiator patch to create three notched bands at 5.15~5.35 GHz, 5.75~5.85 GHz, and 7.25~7.75 GHz for filtering the WLAN and X-band satellite signals. Simulated and measured results both confirm that the proposed antenna has a broad bandwidth of 3.1~12 GHz with VSWR < 2 and good omnidirectional radiation patterns with four notched-bands.

  13. Loss-of-function mutations in Notch receptors in cutaneous and lung squamous cell carcinoma

    OpenAIRE

    Wang, Nicholas J.; Sanborn, Zachary; Arnett, Kelly L.; Bayston, Laura J.; Liao, Wilson; Proby, Charlotte M.; Leigh, Irene M.; Collisson, Eric A.; Gordon, Patricia B.; Jakkula, Lakshmi; Pennypacker, Sally; Zou, Yong; Sharma, Mimansa; North, Jeffrey P.; Vemula, Swapna S.

    2011-01-01

    Squamous cell carcinomas (SCCs) are one of the most frequent forms of human malignancy, but, other than TP53 mutations, few causative somatic aberrations have been identified. We identified NOTCH1 or NOTCH2 mutations in ∼75% of cutaneous SCCs and in a lesser fraction of lung SCCs, defining a spectrum for the most prevalent tumor suppressor specific to these epithelial malignancies. Notch receptors normally transduce signals in response to ligands on neighboring cells, regulating metazoan line...

  14. Effects of DAPT on proliferation of human dental pulp cells and Notch signaling pathway%DAPT对人牙髓细胞Notch信号通路和细胞增殖的影响

    Institute of Scientific and Technical Information of China (English)

    邹晓英; 庄姮; 岳林; 高学军

    2013-01-01

    Objective:To explore whether the γ-secretase inhibitor N-[N-(3,5-difluorophenacetyl-L-alanyl) ]-S-phenylglycine t-butyl ester (DAPT) could inhibit Notch signaling pathway in human dental pulp cells, and its effects on the proliferation ability of the cells. Methods: Human dental pulp cells were primarily cultured from healthy premolars or wisdom teeth extracted intactly. The γ-secretase inhibitor DAPT (5 μmol/L) was added to the culture medium from passage 4 to the end. The cells of passages 4, 8 and 10 were used as check points in this study. The real-time RT-PCR and RT2 Profiler PCR Array were applied to analyze the expression changes of Notch signaling pathway downstream genes. And the methyl thiazolyl tetrazolium (MTT) method was used to test the proliferation ability of the cells. Results: After DAPT was added, Hesl gene expression level decreased significantly in the cells of passages 4, 8 and 10 as compared with that of the same passage cells in the control group. The relative gene expression ratio (experimental/control) decreased to 0. 20 in the cells of passage 10, and the difference was significant (t =33. 143, P =0. 001). The PCR Array results of passage 10 dental pulp cells also showed a decline of Notch signaling pathway downstream genes Hey1 and NR4A2 in the experimental group as compared with the control group. The proliferation of passages 8, and 10 experimental cells were slowed down, and the difference was significant. Conclusion: Notch signaling pathway of human dental pulp cells could be inhibited by DAPT effectively. The proliferation of the cells was slowed down by the effect of DAPT, and the normal life cycle of the cells was affected.%目的:探讨γ-分泌酶抑制剂3,5-二氟苯乙酰-L-丙氨酰-S-苯基甘氨酸t-丁酯{N-[N-(3,5-difluorophena-cetyl-L-alanyl)]-S-phenylglycine t-butyl ester,DAPT}对人牙髓细胞Notch信号通路是否有抑制作用,及对牙髓细胞增殖能力的影响.方法:收集临床上完整拔除的健康

  15. Disentangling stellar activity and planetary signals

    Directory of Open Access Journals (Sweden)

    Santos N.C.

    2011-02-01

    Full Text Available Photospheric stellar activity (i.e. dark spots or bright plages might be an important source of noise and confusion in the radial-velocity (RV measurements. Radial-velocimetry planet search surveys as well as follow-up of photometric transit surveys require a deep understanding and precise characterization of the effects of stellar activity, in order to disentangle it from planetary signals. We simulate dark spots on a rotating stellar photosphere. The variations of the RV are characterized and analyzed according to the stellar inclination, the latitude and the number of spots. The Lomb-Scargle periodograms of the RV variations induced by activity present power at the rotational period Prot of the star and its two-first harmonics Prot/2 and Prot/3. Three adjusted sinusoids fixed at the fundamental period and its two-first harmonics allow to remove about 90% of the RV jitter amplitude. We apply and validate our approach on four known active planet-host stars: HD 189733, GJ 674, CoRoT-7 and ι Hor.

  16. Increased expression of Notch1 in temporal lobe epilepsy:animal models and clinical evidence

    Institute of Scientific and Technical Information of China (English)

    Xijin Liu; Zhiyong Yang; Yaping Yin; Xuejun Deng

    2014-01-01

    Temporal lobe epilepsy is associated with astrogliosis. Notch1 signaling can induce astrogliosis in glioma. However, it remains unknown whether Notch1 signaling is involved in the pathogenesis of epilepsy. This study investigated the presence of Notch1, hairy and enhancer of split-1, and glial fibrillary acidic protein in the temporal neocortex and hippocampus of lithium-pilocar-pine-treated rats. The presence of Notch1 and hairy and enhancer of split-1 was also explored in brain tissues of patients with intractable temporal lobe epilepsy. Quantitative electroencephalo-gram analysis and behavioral observations were used as auxiliary measures. Results revealed that the presence of Notch1, hairy and enhancer of split-1, and glial ifbrillary acidic protein were en-hanced in status epilepticus and vehicle-treated spontaneous recurrent seizures rats, but remain unchanged in the following groups:control, absence of either status epilepticus or spontaneous recurrent seizures, and zileuton-treated spontaneous recurrent seizures. Compared with patient control cases, the presences of Notch1 and hairy and enhancer of split-1 were upregulated in the temporal neocortex of patients with intractable temporal lobe epilepsy. Therefore, these results suggest that Notch1 signaling may play an important role in the onset of temporal lobe epilepsy via astrogliosis. Furthermore, zileuton may be a potential therapeutic strategy for temporal lobe epilepsy by blocking Notch1 signaling.

  17. Atoh7 promotes the differentiation of retinal stem cells derived from Müller cells into retinal ganglion cells by inhibiting Notch signaling

    OpenAIRE

    Song, Wei-tao; Zhang, Xue-yong; Xia, Xiao-Bo

    2013-01-01

    Introduction Retinal Müller cells exhibit the characteristics of retinal progenitor cells, and differentiate into ganglion cells under certain conditions. However, the number of ganglion cells differentiated from retinal Müller cells falls far short of therapeutic needs. This study aimed to develop a novel protocol to promote the differentiation of retinal Müller cells into ganglion cells and explore the underlying signaling mechanisms. Methods Müller cells were isolated and purified from rat...

  18. New Constitutively Active Phytochromes Exhibit Light-Independent Signaling Activity.

    Science.gov (United States)

    Jeong, A-Reum; Lee, Si-Seok; Han, Yun-Jeong; Shin, Ah-Young; Baek, Ayoung; Ahn, Taeho; Kim, Min-Gon; Kim, Young Soon; Lee, Keun Woo; Nagatani, Akira; Kim, Jeong-Il

    2016-08-01

    Plant phytochromes are photoreceptors that mediate a variety of photomorphogenic responses. There are two spectral photoisomers, the red light-absorbing Pr and far-red light-absorbing Pfr forms, and the photoreversible transformation between the two forms is important for the functioning of phytochromes. In this study, we isolated a Tyr-268-to-Val mutant of Avena sativa phytochrome A (AsYVA) that displayed little photoconversion. Interestingly, transgenic plants of AsYVA showed light-independent phytochrome signaling with a constitutive photomorphogenic (cop) phenotype that is characterized by shortened hypocotyls and open cotyledons in the dark. In addition, the corresponding Tyr-303-to-Val mutant of Arabidopsis (Arabidopsis thaliana) phytochrome B (AtYVB) exhibited nuclear localization and interaction with phytochrome-interacting factor 3 (PIF3) independently of light, conferring a constitutive photomorphogenic development to its transgenic plants, which is comparable to the first constitutively active version of phytochrome B (YHB; Tyr-276-to-His mutant). We also found that chromophore ligation was required for the light-independent interaction of AtYVB with PIF3. Moreover, we demonstrated that AtYVB did not exhibit phytochrome B activity when it was localized in the cytosol by fusion with the nuclear export signal and that AsYVA exhibited the full activity of phytochrome A when localized in the nucleus by fusion with the nuclear localization signal. Furthermore, the corresponding Tyr-269-to-Val mutant of Arabidopsis phytochrome A (AtYVA) exhibited similar cop phenotypes in transgenic plants to AsYVA. Collectively, these results suggest that the conserved Tyr residues in the chromophore-binding pocket play an important role during the Pr-to-Pfr photoconversion of phytochromes, providing new constitutively active alleles of phytochromes by the Tyr-to-Val mutation. PMID:27325667

  19. Expression pattern of the Hedgehog signaling pathway in pituitary adenomas.

    Science.gov (United States)

    Yavropoulou, Maria P; Maladaki, Anna; Topouridou, Konstantina; Kotoula, Vasiliki; Poulios, Chris; Daskalaki, Emily; Foroglou, Nikolaos; Karkavelas, George; Yovos, John G

    2016-01-12

    Several studies have demonstrated the role of Wnt and Notch signaling in the pathogenesis of pituitary adenomas, but data are scarce regarding the role of Hedgehog signaling. In this study we investigated the differential expression of gene targets of the Hedgehog signaling pathway. Formalin-fixed, paraffin-embedded specimens from adult patients who underwent transphenoidal resection and normal human pituitary tissues that were obtained from autopsies were used. Clinical information and data from pre-operative MRI scan (extracellular tumor extension, tumor size, displacement of the optic chiasm) were retrieved from the Hospital's database. We used a customized RT(2) Profiler PCR Array, to investigate the expression of genes related to Notch and Hedgehog signaling pathways (PTCH1, PTCH2, GLI1, GLI3, NOTCH3, JAG1, HES1, and HIP). A total of 52 pituitary adenomas (32 non-functioning adenomas, 15 somatotropinomas and 5 prolactinomas) were used in the final analysis. In non-functioning pituitary adenomas there was a significant decrease (approximately 75%) in expression of all Hedgehog related genes that were tested, while Notch3 and Jagged-1 expression was found significantly increased, compared with normal pituitary tissue controls. In contrast, somatotropinomas demonstrated a significant increase in expression of all Hedgehog related genes and a decrease in the expression of Notch3 and Jagged-1. There was no significant difference in the expression of Hedgehog and Notch related genes between prolactinomas and healthy pituitary tissues. Hedgehog signalling appears to be activated in somatotropinomas but not in non-functioning pituitary adenomas in contrast to the expression pattern of Notch signalling pathway. PMID:26620835

  20. Inhibition of Notch1 increases paclitaxel sensitivity to human breast cancer

    Institute of Scientific and Technical Information of China (English)

    Zhao Li; Ma Yongjie; Gu Feng; Fu Li

    2014-01-01

    Background Paclitaxel (PAC) is the first-line chemotherapy drug for most breast cancer patients,but clinical studies showed that some breast cancer patients were insensitive to PAC,which led to chemotherapy failure.It was reported that Notch1 signaling participated in drug resistance of breast cancer.Here,we show whether Notch1 expression is related to PAC sensitivity of breast cancer.Methods We employed Notch1 siRNA and Notch1 inhibitor,N-[N-(3,5-difluorophenacetyl)-1-alanyl]-S-phenylglycine t-butylester (DAPT),to down regulate Notch1 expression in human breast cancer cells MDA-MB-231,and detected the inhibition effect by Western blotting and reverse trans cription-polymerase chain reaction,respectively.After 24 hours exposure to different concentration of PAC (0,1,5,10,15,20,and 25 μg/ml),the viability of the control group and experimental group cells was tested by MTT.We also examined the expression of Notch1 in PAC sensitive and nonsensitive breast cancer patients,respectively by immunohistochemistry (IHC).The PAC sensitivity of breast cancer patients were identified by collagen gel droplet embedded culture-drug sensitivity test (CD-DST).Results Down regulation of Notch1 expression by Notch1siRNA interference or Notch1 inhibitor increased the PAC sensitivity in MDA-MB-231 cells (P <0.05).Also,the expression of Notch1 in PAC sensitive patients was much lower than that of PAC non-sensitive patients (P <0.01).Conclusion Notch1 expression has an effect on PAC sensitivity in breast cancer patients,and the inhibition of Notch1 increases paclitaxel sensitivity to human breast cancer.

  1. A Small UWB Antenna with Dual Band-Notched Characteristics

    Directory of Open Access Journals (Sweden)

    J. Xu

    2012-01-01

    Full Text Available A small novel ultrawideband (UWB antenna with dual band-notched functions is proposed. The dual band rejection is achieved by etching two C-shaped slots on the radiation patch with limited area. A single band-notched antenna is firstly presented, and then an optimized dual band-notched antenna is presented and analyzed. The measured VSWR shows that the proposed antenna could operate from 3.05 to 10.7 GHz with VSWR less than 2, except two stopbands at 3.38 to 3.82 GHz and 5.3 to 5.8 GHz for filtering the WiMAX and WLAN signals. Radiation patterns are simulated by HFSS and verified by CST, and quasiomnidirectional radiation patterns in the H-plane could be observed. Moreover, the proposed antenna has a very compact size and could be easily integrated into portable UWB devices.

  2. NOTCH, ASCL1, p53 and RB alterations define an alternative pathway driving neuroendocrine and small cell lung carcinomas.

    Science.gov (United States)

    Meder, Lydia; König, Katharina; Ozretić, Luka; Schultheis, Anne M; Ueckeroth, Frank; Ade, Carsten P; Albus, Kerstin; Boehm, Diana; Rommerscheidt-Fuss, Ursula; Florin, Alexandra; Buhl, Theresa; Hartmann, Wolfgang; Wolf, Jürgen; Merkelbach-Bruse, Sabine; Eilers, Martin; Perner, Sven; Heukamp, Lukas C; Buettner, Reinhard

    2016-02-15

    Small cell lung cancers (SCLCs) and extrapulmonary small cell cancers (SCCs) are very aggressive tumors arising de novo as primary small cell cancer with characteristic genetic lesions in RB1 and TP53. Based on murine models, neuroendocrine stem cells of the terminal bronchioli have been postulated as the cellular origin of primary SCLC. However, both in lung and many other organs, combined small cell/non-small cell tumors and secondary transitions from non-small cell carcinomas upon cancer therapy to neuroendocrine and small cell tumors occur. We define features of "small cell-ness" based on neuroendocrine markers, characteristic RB1 and TP53 mutations and small cell morphology. Furthermore, here we identify a pathway driving the pathogenesis of secondary SCLC involving inactivating NOTCH mutations, activation of the NOTCH target ASCL1 and canonical WNT-signaling in the context of mutual bi-allelic RB1 and TP53 lesions. Additionally, we explored ASCL1 dependent RB inactivation by phosphorylation, which is reversible by CDK5 inhibition. We experimentally verify the NOTCH-ASCL1-RB-p53 signaling axis in vitro and validate its activation by genetic alterations in vivo. We analyzed clinical tumor samples including SCLC, SCC and pulmonary large cell neuroendocrine carcinomas and adenocarcinomas using amplicon-based Next Generation Sequencing, immunohistochemistry and fluorescence in situ hybridization. In conclusion, we identified a novel pathway underlying rare secondary SCLC which may drive small cell carcinomas in organs other than lung, as well. PMID:26340530

  3. Notch effects in uniaxial tension specimens

    International Nuclear Information System (INIS)

    Results of a literature survey on the effect of notches on the time-dependent failure of uniaxial tension specimens at elevated temperatures are presented. Particular attention is paid to the failure of notched specimens containing weldments

  4. Notch1 as a potential therapeutic target in cutaneous T-cell lymphoma

    DEFF Research Database (Denmark)

    Kamstrup, Maria R; Biskup, Edyta; Lauenborg, Britt Thyssing;

    2010-01-01

    Deregulation of Notch signaling has been linked to the development of T-cell leukemias and several solid malignancies. Yet, it is unknown whether Notch signaling is involved in the pathogenesis of mycosis fungoides and Sézary syndrome, the most common subtypes of cutaneous T-cell lymphoma....... By immunohistochemistry of 40 biopsies taken from skin lesions of mycosis fungoides and Sézary syndrome, we demonstrated prominent expression of Notch1 on tumor cells, especially in the more advanced stages. The ¿-secretase inhibitor I blocked Notch signaling and potently induced apoptosis in cell lines derived from...... mycosis fungoides (MyLa) and Sézary syndrome (SeAx, HuT-78) and in primary leukemic Sézary cells. Specific down-regulation of Notch1 (but not Notch2 and Notch3) by siRNA induced apoptosis in SeAx. The mechanism of apoptosis involved the inhibition of nuclear factor-¿B, which is the most important...

  5. Human ECG signal parameters estimation during controlled physical activity

    Science.gov (United States)

    Maciejewski, Marcin; Surtel, Wojciech; Dzida, Grzegorz

    2015-09-01

    ECG signal parameters are commonly used indicators of human health condition. In most cases the patient should remain stationary during the examination to decrease the influence of muscle artifacts. During physical activity, the noise level increases significantly. The ECG signals were acquired during controlled physical activity on a stationary bicycle and during rest. Afterwards, the signals were processed using a method based on Pan-Tompkins algorithms to estimate their parameters and to test the method.

  6. Arsenite suppression of BMP signaling in human keratinocytes

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, Marjorie A.; Qin, Qin [Department of Environmental Toxicology, University of California, Davis, CA 95616-8588 (United States); Hu, Qin; Zhao, Bin [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Rice, Robert H., E-mail: rhrice@ucdavis.edu [Department of Environmental Toxicology, University of California, Davis, CA 95616-8588 (United States)

    2013-06-15

    Arsenic, a human skin carcinogen, suppresses differentiation of cultured keratinocytes. Exploring the mechanism of this suppression revealed that BMP-6 greatly increased levels of mRNA for keratins 1 and 10, two of the earliest differentiation markers expressed, a process prevented by co-treatment with arsenite. BMP also stimulated, and arsenite suppressed, mRNA for FOXN1, an important transcription factor driving early keratinocyte differentiation. Keratin mRNAs increased slowly after BMP-6 addition, suggesting they are indirect transcriptional targets. Inhibition of Notch1 activation blocked BMP induction of keratins 1 and 10, while FOXN1 induction was largely unaffected. Supporting a requirement for Notch1 signaling in keratin induction, BMP increased levels of activated Notch1, which was blocked by arsenite. BMP also greatly decreased active ERK, while co-treatment with arsenite maintained active ERK. Inhibition of ERK signaling mimicked BMP by inducing keratin and FOXN1 mRNAs and by increasing active Notch1, effects blocked by arsenite. Of 6 dual-specificity phosphatases (DUSPs) targeting ERK, two were induced by BMP unless prevented by simultaneous exposure to arsenite and EGF. Knockdown of DUSP2 or DUSP14 using shRNAs greatly reduced FOXN1 and keratins 1 and 10 mRNA levels and their induction by BMP. Knockdown also decreased activated Notch1, keratin 1 and keratin 10 protein levels, both in the presence and absence of BMP. Thus, one of the earliest effects of BMP is induction of DUSPs, which increases FOXN1 transcription factor and activates Notch1, both required for keratin gene expression. Arsenite prevents this cascade by maintaining ERK signaling, at least in part by suppressing DUSP expression. - Highlights: • BMP induces FOXN1 transcription. • BMP induces DUSP2 and DUSP14, suppressing ERK activation. • Arsenite suppresses levels of phosphorylated Smad1/5 and FOXN1 and DUSP mRNA. • These actions rationalize arsenite suppression of keratinocyte

  7. Necking and notch strengthening in metallic glass with symmetric sharp-and-deep notches

    OpenAIRE

    Sha, Z. D.; Pei, Q. X.; Z. S. Liu; Zhang, Y W; Wang, T J

    2015-01-01

    Notched metallic glasses (MGs) have received much attention recently due to their intriguing mechanical properties compared to their unnotched counterparts, but so far no fundamental understanding of the correlation between failure behavior and notch depth/sharpness exists. Using molecular dynamics simulations, we report necking and large notch strengthening in MGs with symmetric sharp-and-deep notches. Our work reveals that the failure mode and strength of notched MGs are strongly dependent ...

  8. Abnormal recruitment of extracellular matrix proteins by excess Notch3 ECD: a new pathomechanism in CADASIL.

    Science.gov (United States)

    Monet-Leprêtre, Marie; Haddad, Iman; Baron-Menguy, Céline; Fouillot-Panchal, Maï; Riani, Meriem; Domenga-Denier, Valérie; Dussaule, Claire; Cognat, Emmanuel; Vinh, Joelle; Joutel, Anne

    2013-06-01

    Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, or CADASIL, one of the most common inherited small vessel diseases of the brain, is characterized by a progressive loss of vascular smooth muscle cells and extracellular matrix accumulation. The disease is caused by highly stereotyped mutations within the extracellular domain of the NOTCH3 receptor (Notch3(ECD)) that result in an odd number of cysteine residues. While CADASIL-associated NOTCH3 mutations differentially affect NOTCH3 receptor function and activity, they all are associated with early accumulation of Notch3(ECD)-containing aggregates in small vessels. We still lack mechanistic explanation to link NOTCH3 mutations with small vessel pathology. Herein, we hypothesized that excess Notch3(ECD) could recruit and sequester functionally important proteins within small vessels of the brain. We performed biochemical, nano-liquid chromatography-tandem mass spectrometry and immunohistochemical analyses, using cerebral and arterial tissue derived from patients with CADASIL and mouse models of CADASIL that exhibit vascular lesions in the end- and early-stage of the disease, respectively. Biochemical fractionation of brain and artery samples demonstrated that mutant Notch3(ECD) accumulates in disulphide cross-linked detergent-insoluble aggregates in mice and patients with CADASIL. Further proteomic and immunohistochemical analyses identified two functionally important extracellular matrix proteins, tissue inhibitor of metalloproteinases 3 (TIMP3) and vitronectin (VTN) that are sequestered into Notch3(ECD)-containing aggregates. Using cultured cells, we show that increased levels or aggregation of Notch3 enhances the formation of Notch3(ECD)-TIMP3 complex, promoting TIMP3 recruitment and accumulation. In turn, TIMP3 promotes complex formation including NOTCH3 and VTN. In vivo, brain vessels from mice and patients with CADASIL exhibit elevated levels of both insoluble cross

  9. Heat dissipation guides activation in signaling proteins

    OpenAIRE

    Weber, Jeffrey K.; Shukla, Diwakar; Pande, Vijay S.

    2015-01-01

    As with their macroscopic counterparts, the moving parts of nanoscale protein machines grow hot while in operation. A portion of the energy biomolecules harness to perform meaningful work is always dissipated as heat into the surroundings. Here, we feature a methodology by which dominant dissipative trajectories can be extracted from detailed models of protein dynamics. In two important classes of signaling proteins [kinases and G-protein–coupled receptors (GPCRs)], we find that the regions o...

  10. Activity Dependent Signal Transduction in Skeletal Muscle

    Science.gov (United States)

    Hamilton, Susan L.

    1999-01-01

    The overall goals of this project are: 1) to define the initial signal transduction events whereby the removal of gravitational load from antigravity muscles, such as the soleus, triggers muscle atrophy, and 2) to develop countermeasures to prevent this from happening. Our rationale for this approach is that, if countermeasures can be developed to regulate these early events, we could avoid having to deal with the multiple cascades of events that occur downstream from the initial event. One of our major findings is that hind limb suspension causes an early and sustained increase in intracellular Ca(2+) concentration ([Ca (2+)](sub i)). In most cells the consequences of changes in ([Ca (2+)](sub i))depend on the amplitude, frequency and duration of the Ca(2+) signal and on other factors in the intracellular environment. We propose that muscle remodeling in microgravity represents a change in the balance among several CA(2+) regulated signal transduction pathways, in particular those involving the transcription factors NFAT and NFkB and the pro-apoptotic protein BAD. Other Ca(2+) sensitive pathways involving PKC, ras, rac, and CaM kinase II may also contribute to muscle remodeling.

  11. Si3N4 ring resonator-based microwave photonic notch filter with an ultrahigh peak rejection

    OpenAIRE

    Marpaung, David; Morrison, Blair; Pant, Ravi; Roeloffzen, Chris; Leinse, Arne; Hoekman, Marcel; Heideman, Rene; Eggleton, Benjamin J.

    2013-01-01

    We report a simple technique in microwave photonic (MWP) signal processing that allows the use of an optical filter with a shallow notch to exhibit a microwave notch filter with anomalously high rejection level. We implement this technique using a low-loss, tunable Si3N4 optical ring resonator as the optical filter, and achieved an MWP notch filter with an ultra-high peak rejection > 60 dB, a tunable high resolution bandwidth of 247-840 MHz, and notch frequency tuning of 2-8 GHz. To our knowl...

  12. Si3N4 ring resonator-based microwave photonic notch filter with an ultrahigh peak rejection

    CERN Document Server

    Marpaung, David; Pant, Ravi; Roeloffzen, Chris; Leinse, Arne; Hoekman, Marcel; Heideman, Rene; Eggleton, Benjamin J

    2013-01-01

    We report a simple technique in microwave photonic (MWP) signal processing that allows the use of an optical filter with a shallow notch to exhibit a microwave notch filter with anomalously high rejection level. We implement this technique using a low-loss, tunable Si3N4 optical ring resonator as the optical filter, and achieved an MWP notch filter with an ultra-high peak rejection > 60 dB, a tunable high resolution bandwidth of 247-840 MHz, and notch frequency tuning of 2-8 GHz. To our knowledge, this is a record combined peak rejection and resolution for an integrated MWP filter.

  13. Three distinct roles for notch in Drosophila R7 photoreceptor specification.

    Directory of Open Access Journals (Sweden)

    Andrew Tomlinson

    2011-08-01

    Full Text Available Receptor tyrosine kinases (RTKs and Notch (N proteins are different types of transmembrane receptors that transduce extracellular signals and control cell fate. Here we examine cell fate specification in the Drosophila retina and ask how N acts together with the RTKs Sevenless (Sev and the EGF receptor (DER to specify the R7 photoreceptor. The retina is composed of many hundred ommatidia, each of which grows by recruiting surrounding, undifferentiated cells and directing them to particular fates. The R7 photoreceptor derives from a cohort of three cells that are incorporated together following specification of the R2-R5 and R8 photoreceptors. Two cells of the cohort are specified as the R1/6 photoreceptor type by DER activation. These cells then activate N in the third cell (the R7 precursor. By manipulation of N and RTK signaling in diverse combinations we establish three roles for N in specifying the R7 fate. The first role is to impose a block to photoreceptor differentiation; a block that DER activation cannot overcome. The second role, paradoxically, is to negate the first; Notch activation up-regulates Sev expression, enabling the presumptive R7 cell to receive an RTK signal from R8 that can override the block. The third role is to specify the cell as an R7 rather than an R1/6 once RTK signaling has specified the cells as a photoreceptor. We speculate why N acts both to block and to facilitate photoreceptor differentiation, and provide a model for how N and RTK signaling act combinatorially to specify the R1/6 and R7 photoreceptors as well as the surrounding non-neuronal cone cells.

  14. Si3N4 ring resonator-based microwave photonic notch filter with an ultrahigh peak rejection

    NARCIS (Netherlands)

    Marpaung, David; Morrison, Blair; Pant, Ravi; Roeloffzen, Chris; Leinse, Arne; Hoekman, Marcel; Heideman, René; Eggleton, Benjamin J.

    2013-01-01

    We report a simple technique in microwave photonic (MWP) signal processing that allows the use of an optical filter with a shallow notch to exhibit a microwave notch filter with anomalously high rejection level. We implement this technique using a low-loss, tunable Si3N4 optical ring resonator as th

  15. Epidermal growth factor receptor inhibition reduces angiogenesis via hypoxia-inducible factor-1α and Notch1 in head neck squamous cell carcinoma.

    Directory of Open Access Journals (Sweden)

    Wei-Ming Wang

    Full Text Available Angiogenesis, a marker of cancer development, affects response to radiotherapy sensibility. This preclinical study aims to understand the receptor tyrosine kinase-mediated angiogenesis in head neck squamous cell carcinoma (HNSCC. The receptor tyrosine kinase activity in a transgenic mouse model of HNSCC was assessed. The anti-tumorigenetic and anti-angiogenetic effects of cetuximab-induced epidermal growth factor receptor (EGFR inhibition were investigated in xenograft and transgenic mouse models of HNSCC. The signaling transduction of Notch1 and hypoxia-inducible factor-1α (HIF-1α was also analyzed. EGFR was overexpressed and activated in the Tgfbr1/Pten deletion (2cKO mouse model of HNSCC. Cetuximab significantly delayed tumor onset by reducing tumor angiogenesis. This drug exerted similar effects on heterotopic xenograft tumors. In the human HNSCC tissue array, increased EGFR expression correlated with increased HIF-1α and micro vessel density. Cetuximab inhibited tumor-induced angiogenesis in vitro and in vivo by significantly downregulating HIF-1α and Notch1. EGFR is involved in the tumor angiogenesis of HNSCC via the HIF-1α and Notch1 pathways. Therefore, targeting EGFR by suppressing hypoxia- and Notch-induced angiogenesis may benefit HNSCC therapy.

  16. Mechanical behaviors of notched composite laminates

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Presents the study on the mechanical behaviors of composite laminates with both static and fatigue tests per formed with different notched specimens and concludes with experimental results that ultimate strength and initial stiff ness of various notched composite laminates is almost as same as un-notched ones but the fatigue life of notched speci mens is much higher than un-notched ones. Compared with metals, composite materials are notch insensitive. The properties measured by using bar type specimens can not represent the real properties of composite laminates. Notches on the free edge may be helpful to the structure. The fatigue life can be predicted through theoretical models estab lished using the residual stiffness model.

  17. Ultra-high peak rejection notch microwave photonic filter using a single silicon microring resonator.

    Science.gov (United States)

    Long, Yun; Wang, Jian

    2015-07-13

    We propose a simple scheme to realize ultra-high peak rejection notch microwave photonic filter (MPF) based on a single silicon microring resonator (MRR). Using the combination of a conventional phase modulator (PM), a tunable bandpass filter (TBF), and a silicon MRR to manipulate the phase and amplitude of optical sidebands resulting in a signal cancellation at the RF notch filter frequency, we experimentally demonstrate a notch MPF with an ultra-high peak rejection beyond 60 dB. The frequency tunability of the proposed ultra-high peak rejection MPF is also demonstrated in the experiment. PMID:26191836

  18. Wnt Signaling in Neurogenesis during Aging and Physical Activity

    Directory of Open Access Journals (Sweden)

    Michael Chen

    2012-12-01

    Full Text Available Over the past decade, much progress has been made regarding our understanding of neurogenesis in both young and old animals and where it occurs throughout the lifespan, although the growth of new neurons declines with increasing age. In addition, physical activity can reverse this age-dependent decline in neurogenesis. Highly correlated with this decline is the degree of inter and intracellular Wnt signaling, the molecular mechanisms of which have only recently started to be elucidated. So far, most of what we know about intracellular signaling during/following exercise centers around the CREB/CRE initiated transcriptional events. Relatively little is known, however, about how aging and physical activity affect the Wnt signaling pathway. Herein, we briefly review the salient features of neurogenesis in young and then in old adult animals. Then, we discuss Wnt signaling and review the very few in vitro and in vivo studies that have examined the Wnt signaling pathways in aging and physical activity.

  19. Cellular Cholesterol Directly Activates Smoothened in Hedgehog Signaling.

    Science.gov (United States)

    Huang, Pengxiang; Nedelcu, Daniel; Watanabe, Miyako; Jao, Cindy; Kim, Youngchang; Liu, Jing; Salic, Adrian

    2016-08-25

    In vertebrates, sterols are necessary for Hedgehog signaling, a pathway critical in embryogenesis and cancer. Sterols activate the membrane protein Smoothened by binding its extracellular, cysteine-rich domain (CRD). Major unanswered questions concern the nature of the endogenous, activating sterol and the mechanism by which it regulates Smoothened. We report crystal structures of CRD complexed with sterols and alone, revealing that sterols induce a dramatic conformational change of the binding site, which is sufficient for Smoothened activation and is unique among CRD-containing receptors. We demonstrate that Hedgehog signaling requires sterol binding to Smoothened and define key residues for sterol recognition and activity. We also show that cholesterol itself binds and activates Smoothened. Furthermore, the effect of oxysterols is abolished in Smoothened mutants that retain activation by cholesterol and Hedgehog. We propose that the endogenous Smoothened activator is cholesterol, not oxysterols, and that vertebrate Hedgehog signaling controls Smoothened by regulating its access to cholesterol. PMID:27545348

  20. Investigation into the Performance of Bamboo Using the Notched and the Un-Notched Specimen

    OpenAIRE

    L. Gyansah; S. Kwofie

    2011-01-01

    This study investigates the performance of bamboo (Bambusa vulgaris) using the notched and the un-notched specimen. Double v-notched bamboo and un-notched bamboo specimens were used to carry out the experiment. Notched- angles of 20, 30, 60, 80 and 90º were made on each specimen. These were done to ascertain the effect of the notched-angle on the performance of the bamboo. Each specimen was placed in a Uniaxial Compression Machine and was crushed with respect to time. The results are plotted ...

  1. Impact of Spectral Notch Width on Neurophysiological Plasticity and Clinical Effectiveness of the Tailor-Made Notched Music Training.

    Science.gov (United States)

    Wunderlich, Robert; Lau, Pia; Stein, Alwina; Engell, Alva; Wollbrink, Andreas; Rudack, Claudia; Pantev, Christo

    2015-01-01

    Tinnitus, the ringing in the ears that is unrelated to any external source, causes a significant loss in quality of life, involving sleep disturbance and depression for 1 to 3% of the general population. While in the first place tinnitus may be triggered by damage to the inner ear cells, the neural generators of subjective tinnitus are located in central regions of the nervous system. A loss of lateral inhibition, tonotopical reorganization and a gain-increase in response to the sensory deprivation result in hypersensitivity and hyperactivity in certain regions of the auditory cortex. In the tailor-made notched music training (TMNMT) patients listen to music from which the frequency spectrum of the tinnitus has been removed. This evokes strong lateral inhibition from neurons tuned to adjacent frequencies onto the neurons involved in the tinnitus percept. A reduction of tinnitus loudness and tinnitus-related neural activity was achieved with TMNMT in previous studies. As the effect of lateral inhibition depends on the bandwidth of the notch, in the current study we altered the notch width to find the most effective notch width for TMNMT. We compared 1-octave notch width with ½-octave and ¼-octave. Participants chose their favorite music for the training that included three month of two hours daily listening. The outcome was measured by means of standardized questionnaires and magnetoencephalography. We found a general reduction of tinnitus distress in all administered tinnitus questionnaires after the training. Additionally, tinnitus-related neural activity was reduced after the training. Nevertheless, notch width did not have an influence on the behavioral or neural effects of TMNMT. This could be due to a non-linear resolution of lateral inhibition in high frequencies. PMID:26406446

  2. Impact of Spectral Notch Width on Neurophysiological Plasticity and Clinical Effectiveness of the Tailor-Made Notched Music Training.

    Directory of Open Access Journals (Sweden)

    Robert Wunderlich

    Full Text Available Tinnitus, the ringing in the ears that is unrelated to any external source, causes a significant loss in quality of life, involving sleep disturbance and depression for 1 to 3% of the general population. While in the first place tinnitus may be triggered by damage to the inner ear cells, the neural generators of subjective tinnitus are located in central regions of the nervous system. A loss of lateral inhibition, tonotopical reorganization and a gain-increase in response to the sensory deprivation result in hypersensitivity and hyperactivity in certain regions of the auditory cortex. In the tailor-made notched music training (TMNMT patients listen to music from which the frequency spectrum of the tinnitus has been removed. This evokes strong lateral inhibition from neurons tuned to adjacent frequencies onto the neurons involved in the tinnitus percept. A reduction of tinnitus loudness and tinnitus-related neural activity was achieved with TMNMT in previous studies. As the effect of lateral inhibition depends on the bandwidth of the notch, in the current study we altered the notch width to find the most effective notch width for TMNMT. We compared 1-octave notch width with ½-octave and ¼-octave. Participants chose their favorite music for the training that included three month of two hours daily listening. The outcome was measured by means of standardized questionnaires and magnetoencephalography. We found a general reduction of tinnitus distress in all administered tinnitus questionnaires after the training. Additionally, tinnitus-related neural activity was reduced after the training. Nevertheless, notch width did not have an influence on the behavioral or neural effects of TMNMT. This could be due to a non-linear resolution of lateral inhibition in high frequencies.

  3. Withaferin A inhibits in vivo growth of breast cancer cells accelerated by Notch2 knockdown.

    Science.gov (United States)

    Kim, Su-Hyeong; Hahm, Eun-Ryeong; Arlotti, Julie A; Samanta, Suman K; Moura, Michelle B; Thorne, Stephen H; Shuai, Yongli; Anderson, Carolyn J; White, Alexander G; Lokshin, Anna; Lee, Joomin; Singh, Shivendra V

    2016-05-01

    The present study offers novel insights into the molecular circuitry of accelerated in vivo tumor growth by Notch2 knockdown in triple-negative breast cancer (TNBC) cells. Therapeutic vulnerability of Notch2-altered growth to a small molecule (withaferin A, WA) is also demonstrated. MDA-MB-231 and SUM159 cells were used for the xenograft studies. A variety of technologies were deployed to elucidate the mechanisms underlying tumor growth augmentation by Notch2 knockdown and its reversal by WA, including Fluorescence Molecular Tomography for measurement of tumor angiogenesis in live mice, Seahorse Flux analyzer for ex vivo measurement of tumor metabolism, proteomics, and Luminex-based cytokine profiling. Stable knockdown of Notch2 resulted in accelerated in vivo tumor growth in both cells reflected by tumor volume and/or latency. For example, the wet tumor weight from mice bearing Notch2 knockdown MDA-MB-231 cells was about 7.1-fold higher compared with control (P medicinal plant. Molecular underpinnings for tumor growth intensification by Notch2 knockdown included compensatory increase in Notch1 activation, increased cellular proliferation and/or angiogenesis, and increased plasma or tumor levels of growth stimulatory cytokines. WA administration reversed many of these effects providing explanation for its remarkable anti-cancer efficacy. Notch2 functions as a tumor growth suppressor in TNBC and WA offers a novel therapeutic strategy for restoring this function. PMID:27097807

  4. Regulation of the embryonic morphogen Nodal by Notch4 facilitates manifestation of the aggressive melanoma phenotype

    OpenAIRE

    Hardy, Katharine M.; Kirschmann, Dawn A; Seftor, Elisabeth A.; Margaryan, Naira v.; Postovit, Lynne-Marie; Strizzi, Luigi; Hendrix, Mary J.C.

    2010-01-01

    Metastatic melanoma is an aggressive skin cancer associated with poor prognosis. The reactivation of the embryonic morphogen Nodal in metastatic melanoma has previously been shown to regulate the aggressive behavior of these tumor cells. During the establishment of left-right asymmetry in early vertebrate development, Nodal expression is specifically regulated by a Notch signaling pathway. We hypothesize that a similar relationship between Notch and Nodal may be re-established in melanoma. In...

  5. Mislocalized activation of oncogenic RTKs switches downstream signaling outcomes

    DEFF Research Database (Denmark)

    Choudhary, Chuna Ram; Olsen, Jesper V; Brandts, Christian;

    2009-01-01

    Inappropriate activation of oncogenic kinases at intracellular locations is frequently observed in human cancers, but its effects on global signaling are incompletely understood. Here, we show that the oncogenic mutant of Flt3 (Flt3-ITD), when localized at the endoplasmic reticulum (ER), aberrantly...... patterns of the receptor itself. Thus, intracellular activation of RTKs by oncogenic mutations in the biosynthetic route may exploit cellular architecture to initiate aberrant signaling cascades, thus evading negative regulation....

  6. Rer1p maintains ciliary length and signaling by regulating γ-secretase activity and Foxj1a levels.

    Science.gov (United States)

    Jurisch-Yaksi, Nathalie; Rose, Applonia J; Lu, Huiqi; Raemaekers, Tim; Munck, Sebastian; Baatsen, Pieter; Baert, Veerle; Vermeire, Wendy; Scales, Suzie J; Verleyen, Daphne; Vandepoel, Roel; Tylzanowski, Przemko; Yaksi, Emre; de Ravel, Thomy; Yost, H Joseph; Froyen, Guy; Arrington, Cammon B; Annaert, Wim

    2013-03-18

    Cilia project from the surface of most vertebrate cells and are important for several physiological and developmental processes. Ciliary defects are linked to a variety of human diseases, named ciliopathies, underscoring the importance of understanding signaling pathways involved in cilia formation and maintenance. In this paper, we identified Rer1p as the first endoplasmic reticulum/cis-Golgi-localized membrane protein involved in ciliogenesis. Rer1p, a protein quality control receptor, was highly expressed in zebrafish ciliated organs and regulated ciliary structure and function. Both in zebrafish and mammalian cells, loss of Rer1p resulted in the shortening of cilium and impairment of its motile or sensory function, which was reflected by hearing, vision, and left-right asymmetry defects as well as decreased Hedgehog signaling. We further demonstrate that Rer1p depletion reduced ciliary length and function by increasing γ-secretase complex assembly and activity and, consequently, enhancing Notch signaling as well as reducing Foxj1a expression.

  7. Delta-Notch Lateral Inhibition within the Organ of Corti

    Science.gov (United States)

    Summers, R.; Abdulla, T.; Luff, R.

    2013-09-01

    Lateral inhibition is described as an emergent property of the Delta-Notch signalling network. Two separate model representations of lateral inhibition are proposed for different purposes. One provides information about bioenergetics while the other has the capability to produce a physical representation. It is proposed that both can be used in further studies of the sensory pathways in the human connectome model of brain function.

  8. Exosomes in developmental signalling.

    Science.gov (United States)

    McGough, Ian John; Vincent, Jean-Paul

    2016-07-15

    In order to achieve coordinated growth and patterning during development, cells must communicate with one another, sending and receiving signals that regulate their activities. Such developmental signals can be soluble, bound to the extracellular matrix, or tethered to the surface of adjacent cells. Cells can also signal by releasing exosomes - extracellular vesicles containing bioactive molecules such as RNA, DNA and enzymes. Recent work has suggested that exosomes can also carry signalling proteins, including ligands of the Notch receptor and secreted proteins of the Hedgehog and WNT families. Here, we describe the various types of exosomes and their biogenesis. We then survey the experimental strategies used so far to interfere with exosome formation and critically assess the role of exosomes in developmental signalling. PMID:27436038

  9. 心电信号工频干扰陷波器的设计与实现%Design and Implementation of 50 Hz Notch Filter for ECG Signal Power Interference

    Institute of Scientific and Technical Information of China (English)

    张喜红; 王玉香

    2014-01-01

    Taking C8051F362 as the core processor, designs FIR filter by means of window function method to develop portable and low cost ECG monitoring device. On Mattlab simulation platform, designs 30 Hz and 40 Hz low pass filters, and makes the two cascade combination for a 50 Hz notch filter, then applies the heuristic method and zero, pole adjustment method to adjust the filter coefficient of notch filter, and makes the filter to meet the requirements of ECG filtering and adapt to transplantation to C8051F362 single-chip computer. Tests the notch filter with a lot of ECG data in the MIT-BIH database, and the results demonstrate the validity and superiority of this algorithm.%为了使心电监护装置便携化、低成本,以C8051F362为核心处理器,利用窗函数法设计FIR型滤波器。借助Matlab仿真平台,设计了30 Hz低通滤波器和40 Hz低通滤波器,并将二者级联组合为一个50 Hz陷波器,再采用试探法和零、极点调整法对陷波器的滤波系数进行调整,使其满足心电滤波要求,并能移植到C8051F362单片机上。以MIT-BIH数据库中的多段心电信号为数据源,对本陷波器进行测试,测试结果证明了本算法的有效性和优越性。

  10. Xia, J.; et al., Arsenic Trioxide Inhibits Cell Growth and Induces Apoptosis through Inactivation of Notch Signaling Pathway in Breast Cancer. Int. J. Mol. Sci. 2012, 13, 9627–9641

    Directory of Open Access Journals (Sweden)

    Jun Xia

    2014-08-01

    Full Text Available The authors wish to change Figure 5D of the paper published in IJMS [1]. In Figure 5D, the bands for NF-κB and Bcl-2 are similar with Notch-1 bands. The authors have carefully checked the original files and found that it is an inadvertent mistake in the published version of Figure 5D. Figure 5 is revised as follows. The authors would like to apologize for any inconvenience caused to the readers by these changes.[...

  11. Activation of the Canonical Wnt Signaling Pathway Induces Cementum Regeneration.

    Science.gov (United States)

    Han, Pingping; Ivanovski, Saso; Crawford, Ross; Xiao, Yin

    2015-07-01

    Canonical Wnt signaling is important in tooth development but it is unclear whether it can induce cementogenesis and promote the regeneration of periodontal tissues lost because of disease. Therefore, the aim of this study is to investigate the influence of canonical Wnt signaling enhancers on human periodontal ligament cell (hPDLCs) cementogenic differentiation in vitro and cementum repair in a rat periodontal defect model. Canonical Wnt signaling was induced by (1) local injection of lithium chloride; (2) local injection of sclerostin antibody; and (3) local injection of a lentiviral construct overexpressing β-catenin. The results showed that the local activation of canonical Wnt signaling resulted in significant new cellular cementum deposition and the formation of well-organized periodontal ligament fibers, which was absent in the control group. In vitro experiments using hPDLCs showed that the Wnt signaling pathway activators significantly increased mineralization, alkaline phosphatase (ALP) activity, and gene and protein expression of the bone and cementum markers osteocalcin (OCN), osteopontin (OPN), cementum protein 1 (CEMP1), and cementum attachment protein (CAP). Our results show that the activation of the canonical Wnt signaling pathway can induce in vivo cementum regeneration and in vitro cementogenic differentiation of hPDLCs. PMID:25556853

  12. The jagged-2/notch-1/hes-1 pathway is involved in intestinal epithelium regeneration after intestinal ischemia-reperfusion injury.

    Directory of Open Access Journals (Sweden)

    Guoqing Chen

    Full Text Available BACKGROUND: Notch signaling plays a critical role in the maintenance of intestinal crypt epithelial cell proliferation. The aim of this study was to investigate the role of Notch signaling in the proliferation and regeneration of intestinal epithelium after intestinal ischemia reperfusion (I/R injury. METHODS: Male Sprague-Dawley rats were subjected to sham operation or I/R by occlusion of the superior mesenteric artery (SMA for 20 min. Intestinal tissue samples were collected at 0, 1, 2, 4, and 6 h after reperfusion. Proliferation of the intestinal epithelium was evaluated by immunohistochemical staining of proliferating nuclear antigen (PCNA. The mRNA and protein expression levels of Notch signaling components were examined using Real-time PCR and Western blot analyses. Immunofluorescence was also performed to detect the expression and location of Jagged-2, cleaved Notch-1, and Hes-1 in the intestine. Finally, the γ-secretase inhibitor DAPT and the siRNA for Jagged-2 and Hes-1 were applied to investigate the functional role of Notch signaling in the proliferation of intestinal epithelial cells in an in vitro IEC-6 culture system. RESULTS: I/R injury caused increased intestinal crypt epithelial cell proliferation and increased mRNA and protein expression of Jagged-2, Notch-1, and Hes-1. The immunofluorescence results further confirmed increased protein expression of Jagged-2, cleaved Notch-1, and Hes-1 in the intestinal crypts. The inhibition of Notch signaling with DAPT and the suppression of Jagged-2 and Hes-1 expression using siRNA both significantly inhibited the proliferation of IEC-6 cells. CONCLUSION: The Jagged-2/Notch-1/Hes-1 signaling pathway is involved in intestinal epithelium regeneration early after I/R injury by increasing crypt epithelial cell proliferation.

  13. Cholinergic signals in mouse barrel cortex during active whisker sensing.

    Science.gov (United States)

    Eggermann, Emmanuel; Kremer, Yves; Crochet, Sylvain; Petersen, Carl C H

    2014-12-11

    Internal brain states affect sensory perception, cognition, and learning. Many neocortical areas exhibit changes in the pattern and synchrony of neuronal activity during quiet versus active behaviors. Active behaviors are typically associated with desynchronized cortical dynamics. Increased thalamic firing contributes importantly to desynchronize mouse barrel cortex during active whisker sensing. However, a whisking-related cortical state change persists after thalamic inactivation, which is mediated at least in part by acetylcholine, as we show here by using whole-cell recordings, local pharmacology, axonal calcium imaging, and optogenetic stimulation. During whisking, we find prominent cholinergic signals in the barrel cortex, which suppress spontaneous cortical activity. The desynchronized state of barrel cortex during whisking is therefore driven by at least two distinct signals with opposing functions: increased thalamic activity driving glutamatergic excitation of the cortex and increased cholinergic input suppressing spontaneous cortical activity.

  14. Cholinergic Signals in Mouse Barrel Cortex during Active Whisker Sensing

    Directory of Open Access Journals (Sweden)

    Emmanuel Eggermann

    2014-12-01

    Full Text Available Internal brain states affect sensory perception, cognition, and learning. Many neocortical areas exhibit changes in the pattern and synchrony of neuronal activity during quiet versus active behaviors. Active behaviors are typically associated with desynchronized cortical dynamics. Increased thalamic firing contributes importantly to desynchronize mouse barrel cortex during active whisker sensing. However, a whisking-related cortical state change persists after thalamic inactivation, which is mediated at least in part by acetylcholine, as we show here by using whole-cell recordings, local pharmacology, axonal calcium imaging, and optogenetic stimulation. During whisking, we find prominent cholinergic signals in the barrel cortex, which suppress spontaneous cortical activity. The desynchronized state of barrel cortex during whisking is therefore driven by at least two distinct signals with opposing functions: increased thalamic activity driving glutamatergic excitation of the cortex and increased cholinergic input suppressing spontaneous cortical activity.

  15. G protein activation stimulates phospholipase D signaling in plants

    NARCIS (Netherlands)

    Munnik, T.; Arisz, S.A.; Vrije, de T.; Musgrave, A.

    1995-01-01

    We provide direct evidence for phospholipase D (PLD) signaling in plants by showing that this enzyme is stimulated by the G protein activators mastoparan, ethanol, and cholera toxin. An in vivo assay for PLD activity in plant cells was developed based on the use of a "reporter alcohol" rather than w

  16. Modulation of β-catenin signaling by glucagon receptor activation.

    Directory of Open Access Journals (Sweden)

    Jiyuan Ke

    Full Text Available The glucagon receptor (GCGR is a member of the class B G protein-coupled receptor family. Activation of GCGR by glucagon leads to increased glucose production by the liver. Thus, glucagon is a key component of glucose homeostasis by counteracting the effect of insulin. In this report, we found that in addition to activation of the classic cAMP/protein kinase A (PKA pathway, activation of GCGR also induced β-catenin stabilization and activated β-catenin-mediated transcription. Activation of β-catenin signaling was PKA-dependent, consistent with previous reports on the parathyroid hormone receptor type 1 (PTH1R and glucagon-like peptide 1 (GLP-1R receptors. Since low-density-lipoprotein receptor-related protein 5 (Lrp5 is an essential co-receptor required for Wnt protein mediated β-catenin signaling, we examined the role of Lrp5 in glucagon-induced β-catenin signaling. Cotransfection with Lrp5 enhanced the glucagon-induced β-catenin stabilization and TCF promoter-mediated transcription. Inhibiting Lrp5/6 function using Dickkopf-1(DKK1 or by expression of the Lrp5 extracellular domain blocked glucagon-induced β-catenin signaling. Furthermore, we showed that Lrp5 physically interacted with GCGR by immunoprecipitation and bioluminescence resonance energy transfer assays. Together, these results reveal an unexpected crosstalk between glucagon and β-catenin signaling, and may help to explain the metabolic phenotypes of Lrp5/6 mutations.

  17. Digital signaling decouples activation probability and population heterogeneity

    DEFF Research Database (Denmark)

    Kellogg, Ryan A; Tian, Chengzhe; Lipniacki, Tomasz;

    2015-01-01

    Digital signaling enhances robustness of cellular decisions in noisy environments, but it is unclear how digital systems transmit temporal information about a stimulus. To understand how temporal input information is encoded and decoded by the NF-κB system, we studied transcription factor dynamic...... and uniform dynamics. These results show that digital NF-κB signaling enables multidimensional control of cellular phenotype via input profile, allowing parallel and independent control of single-cell activation probability and population heterogeneity....

  18. Modeling ductal carcinoma in situ: a HER2-Notch3 collaboration enables luminal filling.

    LENUS (Irish Health Repository)

    Pradeep, C-R

    2012-02-16

    A large fraction of ductal carcinoma in situ (DCIS), a non-invasive precursor lesion of invasive breast cancer, overexpresses the HER2\\/neu oncogene. The ducts of DCIS are abnormally filled with cells that evade apoptosis, but the underlying mechanisms remain incompletely understood. We overexpressed HER2 in mammary epithelial cells and observed growth factor-independent proliferation. When grown in extracellular matrix as three-dimensional spheroids, control cells developed a hollow lumen, but HER2-overexpressing cells populated the lumen by evading apoptosis. We demonstrate that HER2 overexpression in this cellular model of DCIS drives transcriptional upregulation of multiple components of the Notch survival pathway. Importantly, luminal filling required upregulation of a signaling pathway comprising Notch3, its cleaved intracellular domain and the transcriptional regulator HES1, resulting in elevated levels of c-MYC and cyclin D1. In line with HER2-Notch3 collaboration, drugs intercepting either arm reverted the DCIS-like phenotype. In addition, we report upregulation of Notch3 in hyperplastic lesions of HER2 transgenic animals, as well as an association between HER2 levels and expression levels of components of the Notch pathway in tumor specimens of breast cancer patients. Therefore, it is conceivable that the integration of the Notch and HER2 signaling pathways contributes to the pathophysiology of DCIS.

  19. Activation of cell signaling via optical manipulation of gold-coated liposomes encapsulating signaling molecules

    Science.gov (United States)

    Orsinger, Gabriel V.; Leung, Sarah J.; Romanowski, Marek

    2013-02-01

    Many diseases involve changes in cell signaling cascades, as seen commonly in drug resistant cancers. To better understand these intricate signaling events in diseased cells and tissues, experimental methods of probing cellular communication at a single to multi-cell level are required. We recently introduced a general platform for activation of selected signaling pathways by optically controlled delivery and release of water soluble factors using gold-coated liposomes. In the example presented here, we encapsulated inositol trisphosphate (IP3), a ubiquitous intracellular secondary messenger involved in GPCR and Akt signaling cascades, within 100 nm gold-coated liposomes. The high polarizability of the liposome's unique gold pseudo-shell allows stable optical trapping for subcellular manipulation in the presence of cells. We take this optical manipulation further by optically injecting IP3-containing liposomes into the cytosol of a single cell to initiate localized cell signaling. Upon optical injection of liposomal IP3 into a single ovarian carcinoma cell, we observed localized activation as reported by changes in Indo-1 fluorescence intensity. With established gap junctions between the injected cell and neighboring cells, we monitored propagation of this signaling to and through nearby cells.

  20. Determination of strongly overlapping signaling activity from microarray data

    Directory of Open Access Journals (Sweden)

    Bidaut Ghislain

    2006-02-01

    Full Text Available Abstract Background As numerous diseases involve errors in signal transduction, modern therapeutics often target proteins involved in cellular signaling. Interpretation of the activity of signaling pathways during disease development or therapeutic intervention would assist in drug development, design of therapy, and target identification. Microarrays provide a global measure of cellular response, however linking these responses to signaling pathways requires an analytic approach tuned to the underlying biology. An ongoing issue in pattern recognition in microarrays has been how to determine the number of patterns (or clusters to use for data interpretation, and this is a critical issue as measures of statistical significance in gene ontology or pathways rely on proper separation of genes into groups. Results Here we introduce a method relying on gene annotation coupled to decompositional analysis of global gene expression data that allows us to estimate specific activity on strongly coupled signaling pathways and, in some cases, activity of specific signaling proteins. We demonstrate the technique using the Rosetta yeast deletion mutant data set, decompositional analysis by Bayesian Decomposition, and annotation analysis using ClutrFree. We determined from measurements of gene persistence in patterns across multiple potential dimensionalities that 15 basis vectors provides the correct dimensionality for interpreting the data. Using gene ontology and data on gene regulation in the Saccharomyces Genome Database, we identified the transcriptional signatures of several cellular processes in yeast, including cell wall creation, ribosomal disruption, chemical blocking of protein synthesis, and, criticially, individual signatures of the strongly coupled mating and filamentation pathways. Conclusion This works demonstrates that microarray data can provide downstream indicators of pathway activity either through use of gene ontology or transcription

  1. Glucose Enhances Leptin Signaling through Modulation of AMPK Activity

    OpenAIRE

    Haoran Su; Lin Jiang; Christin Carter-Su; Liangyou Rui

    2012-01-01

    Leptin exerts its action by binding to and activating the long form of leptin receptors (LEPRb). LEPRb activates JAK2 that subsequently phosphorylates and activates STAT3. The JAK2/STAT3 pathway is required for leptin control of energy balance and body weight. Defects in leptin signaling lead to leptin resistance, a primary risk factor for obesity. Body weight is also regulated by nutrients, including glucose. Defects in glucose sensing also contribute to obesity. Here we report crosstalk bet...

  2. Asynchronous combinatorial action of four regulatory factors activates Bcl11b for T cell commitment.

    Science.gov (United States)

    Kueh, Hao Yuan; Yui, Mary A; Ng, Kenneth K H; Pease, Shirley S; Zhang, Jingli A; Damle, Sagar S; Freedman, George; Siu, Sharmayne; Bernstein, Irwin D; Elowitz, Michael B; Rothenberg, Ellen V

    2016-08-01

    During T cell development, multipotent progenitors relinquish competence for other fates and commit to the T cell lineage by turning on Bcl11b, which encodes a transcription factor. To clarify lineage commitment mechanisms, we followed developing T cells at the single-cell level using Bcl11b knock-in fluorescent reporter mice. Notch signaling and Notch-activated transcription factors collaborate to activate Bcl11b expression irrespectively of Notch-dependent proliferation. These inputs work via three distinct, asynchronous mechanisms: an early locus 'poising' function dependent on TCF-1 and GATA-3, a stochastic-permissivity function dependent on Notch signaling, and a separate amplitude-control function dependent on Runx1, a factor already present in multipotent progenitors. Despite their necessity for Bcl11b expression, these inputs act in a stage-specific manner, providing a multitiered mechanism for developmental gene regulation. PMID:27376470

  3. Regulation of Notch-mediated transcription by a bovine herpesvirus 1 encoded protein (ORF2) that is expressed in latently infected sensory neurons.

    Science.gov (United States)

    Liu, Yilin; Jones, Clinton

    2016-08-01

    Bovine herpesvirus 1 (BoHV-1) is an Alphaherpesvirinae subfamily member that establishes life-long latency in sensory neurons. The latency-related RNA (LR-RNA) is abundantly expressed during latency. An LR mutant virus containing stop codons at the amino-terminus of open reading frame (ORF)2 does not reactivate from latency and replicates less efficiently in tonsils and trigeminal ganglia. ORF2 inhibits apoptosis, interacts with Notch family members, and interferes with Notch-dependent transcription suggesting ORF2 expression enhances survival of infected neurons. The Notch signaling pathway is crucial for neuronal differentiation and survival suggesting that interactions between ORF2 and Notch family members regulate certain aspects of latency. Consequently, for this study, we compared whether ORF2 interfered with the four mammalian Notch family members. ORF2 consistently interfered with Notch1-3-mediated transactivation of three cellular promoters. Conversely, Notch4-mediated transcription was not consistently inhibited by ORF2. Electrophoretic shift mobility assays using four copies of a consensus-DNA binding site for Notch/CSL (core binding factor (CBF)-1, Suppressor of Hairless, Lag-2) as a probe revealed ORF2 interfered with Notch1 and 3 interactions with a CSL family member bound to DNA. Additional studies demonstrated ORF2 enhances neurite sprouting in mouse neuroblastoma cells that express Notch1-3, but not Notch4. Collectively, these studies indicate that ORF2 inhibits Notch-mediated transcription and signaling by interfering with Notch interacting with CSL bound to DNA. PMID:26846632

  4. HIGHLY CONSERVED O-FUCOSE SITES HAVE DISTINCT EFFECTS ON NOTCH1 FUNCTION

    OpenAIRE

    Rampal, Raajit; Arboleda-Velasquez, Joseph F.; Nita-Lazar, Alexandra; Kosik, Kenneth S.; Haltiwanger, Robert S

    2005-01-01

    The extracellular domain of mouse Notch1 contains 36 tandem epidermal growth factor like (EGF) repeats, many of which are modified with O-fucose. Previous work from several laboratories has indicated that O-fucosylation plays an important role in ligand mediated Notch activation. Nonetheless, it is not clear whether all, or a subset, of the EGF repeats need to be O-fucosylated. Three O-fucose sites are invariantly conserved in all Notch homologues with 36 EGF repeats (within EGF repeats 12, 2...

  5. Two pathways for importing GDP-fucose into the endoplasmic reticulum lumen function redundantly in the O-fucosylation of Notch in Drosophila.

    Science.gov (United States)

    Ishikawa, Hiroyuki O; Ayukawa, Tomonori; Nakayama, Minoru; Higashi, Shunsuke; Kamiyama, Shin; Nishihara, Shoko; Aoki, Kazuhisa; Ishida, Nobuhiro; Sanai, Yutaka; Matsuno, Kenji

    2010-02-01

    Notch is a transmembrane receptor that shares homology with proteins containing epidermal growth factor-like repeats and mediates the cell-cell interactions necessary for many cell fate decisions. In Drosophila, O-fucosyltransferase 1 catalyzes the O-fucosylation of these epidermal growth factor-like repeats. This O-fucose elongates, resulting in an O-linked tetrasaccharide that regulates the signaling activities of Notch. Fucosyltransferases utilize GDP-fucose, which is synthesized in the cytosol, but fucosylation occurs in the lumen of the endoplasmic reticulum (ER) and Golgi. Therefore, GDP-fucose uptake into the ER and Golgi is essential for fucosylation. However, although GDP-fucose biosynthesis is well understood, the mechanisms and intracellular routes of GDP-fucose transportation remain unclear. Our previous study on the Drosophila Golgi GDP-fucose transporter (Gfr), which specifically localizes to the Golgi, suggested that another GDP-fucose transporter(s) exists in Drosophila. Here, we identified Efr (ER GDP-fucose transporter), a GDP-fucose transporter that localizes specifically to the ER. Efr is a multifunctional nucleotide sugar transporter involved in the biosynthesis of heparan sulfate-glycosaminoglycan chains and the O-fucosylation of Notch. Comparison of the fucosylation defects in the N-glycans in Gfr and Efr mutants revealed that Gfr and Efr made distinct contributions to this modification; Gfr but not Efr was crucial for the fucosylation of N-glycans. We also found that Gfr and Efr function redundantly in the O-fucosylation of Notch, although they had different localizations and nucleotide sugar transportation specificities. These results indicate that two pathways for the nucleotide sugar supply, involving two nucleotide sugar transporters with distinct characteristics and distributions, contribute to the O-fucosylation of Notch. PMID:19948734

  6. WNT signaling in activated microglia is pro-inflammatory: WNT/β-catenin signaling in microglia

    OpenAIRE

    Halleskog, Carina; Mulder, Jan; Dahlström, Jenny; Mackie, Ken; Hortobágyi, Tibor; Tanila, Heikki; Puli, Lakshman Kumar; Färber, Katrin; Harkany, Tibor; Schulte, Gunnar

    2010-01-01

    Microglia activation is central to the neuroinflammation associated with neurological and neurodegenerative diseases, particularly since activated microglia are often a source of pro-inflammatory cytokines. Despite decades-long research, the molecular cascade of pro-inflammatory transformation of microglia in vivo remains largely elusive. Here, we report increased β–catenin expression, a central intracellular component of WNT signaling, in microglia undergoing a pro-inflammatory morphogenic t...

  7. DOL behaviour of end-notched beams

    DEFF Research Database (Denmark)

    Gustafsson, P.J.; Hoffmeyer, Preben; Valentin, G.

    1998-01-01

    The long-term loading strength of end-notched beams made of glulam and LVL was tested. The beams were of various sizes, with and without a moisture sealing at the notch. Tests were conducted in open shelter climates, and at constant and cyclic relative humidity. The short-term strength was tested...

  8. Mitogen-activated protein kinase signaling in plants

    DEFF Research Database (Denmark)

    Rodriguez, Maria Cristina Suarez; Petersen, Morten; Mundy, John

    2010-01-01

    of substrate proteins, whose altered activities mediate a wide array of responses, including changes in gene expression. Cascades may share kinase components, but their signaling specificity is maintained by spaciotemporal constraints and dynamic protein-protein interactions and by mechanisms that include......Eukaryotic mitogen-activated protein kinase (MAPK) cascades have evolved to transduce environmental and developmental signals into adaptive and programmed responses. MAPK cascades relay and amplify signals via three types of reversibly phosphorylated kinases leading to the phosphorylation...... crossinhibition, feedback control, and scaffolding. Plant MAPK cascades regulate numerous processes, including stress and hormonal responses, innate immunity, and developmental programs. Genetic analyses have uncovered several predominant MAPK components shared by several of these processes including...

  9. MEKK1/JNK signaling stabilizes and activates p53

    OpenAIRE

    Fuchs, Serge Y.; Adler, Victor; Pincus, Matthew R.; Ronai, Ze’ev

    1998-01-01

    Activation of the tumor suppressor p53 by stress and damage stimuli often correlates with induction of stress kinases, Jun-NH2 kinase (JNK). As JNK association with p53 plays an important role in p53 stability, in the present study we have elucidated the relationship between the JNK-signaling pathway and p53 stability and activity. Expression of a constitutively active form of JNKK upstream kinase, mitogen-activated protein kinase kinase kinase (ΔMEKK1), increased the level of the exogenously...

  10. Active Harmonic Load–Pull With Realistic Wideband Communications Signals

    NARCIS (Netherlands)

    Marchetti, M.; Pelk, M.J.; Buisman, K.; Neo, W.C.E.; Spirito, M.; De Vreede, L.C.N.

    2008-01-01

    A new wideband open-loop active harmonic load–pull measurement approach is presented. The proposed method is based on wideband data-acquisition and wideband signal-injection of the incident and device generated power waves at the frequencies of interest. The system provides full, user defined, in-ba

  11. Mitogen-activated protein kinase and abscisic acid signal transduction

    NARCIS (Netherlands)

    Heimovaara-Dijkstra, S.; Testerink, C.; Wang, M.

    1998-01-01

    The phytohormone abscisic acid (ABA) is a classical plant hormone, responsible for regulation of abscission, diverse aspects of plant and seed development, stress responses and germination. It was found that ABA signal transduction in plants can involve the activity of type 2C-phosphatases (PP2C), c

  12. Identification of small molecule activators of BMP signaling.

    Directory of Open Access Journals (Sweden)

    Karen Vrijens

    Full Text Available Bone Morphogenetic Proteins (BMPs are morphogens that play a major role in regulating development and homeostasis. Although BMPs are used for the treatment of bone and kidney disorders, their clinical use is limited due to the supra-physiological doses required for therapeutic efficacy causing severe side effects. Because recombinant BMPs are expensive to produce, small molecule activators of BMP signaling would be a cost-effective alternative with the added benefit of being potentially more easily deliverable. Here, we report our efforts to identify small molecule activators of BMP signaling. We have developed a cell-based assay to monitor BMP signaling by stably transfecting a BMP-responsive human cervical carcinoma cell line (C33A with a reporter construct in which the expression of luciferase is driven by a multimerized BMP-responsive element from the Id1 promoter. A BMP-responsive clone C33A-2D2 was used to screen a bioactive library containing ∼5,600 small molecules. We identified four small molecules of the family of flavonoids all of which induced luciferase activity in a dose-dependent manner and ventralized zebrafish embryos. Two of the identified compounds induced Smad1, 5 phosphorylation (P-Smad, Id1 and Id2 expression in a dose-dependent manner demonstrating that our assays identified small molecule activators of BMP signaling.

  13. Steroid signaling activation and intracellular localization of sex steroid receptors

    OpenAIRE

    Giraldi, Tiziana; Giovannelli, Pia; Di Donato, Marzia; Castoria, Gabriella; Migliaccio, Antimo; Auricchio, Ferdinando

    2010-01-01

    In addition to stimulating gene transcription, sex steroids trigger rapid, non-genomic responses in the extra-nuclear compartment of target cells. These events take place within seconds or minutes after hormone administration and do not require transcriptional activity of sex steroid receptors. Depending on cell systems, activation of extra-nuclear signaling pathways by sex steroids fosters cell cycle progression, prevents apoptosis, leads to epigenetic modifications and increases cell migrat...

  14. Survey of activated FLT3 signaling in leukemia.

    Directory of Open Access Journals (Sweden)

    Ting-lei Gu

    Full Text Available Activating mutations of FMS-like tyrosine kinase-3 (FLT3 are found in approximately 30% of patients with acute myeloid leukemia (AML. FLT3 is therefore an attractive drug target. However, the molecular mechanisms by which FLT3 mutations lead to cell transformation in AML remain unclear. To develop a better understanding of FLT3 signaling as well as its downstream effectors, we performed detailed phosphoproteomic analysis of FLT3 signaling in human leukemia cells. We identified over 1000 tyrosine phosphorylation sites from about 750 proteins in both AML (wild type and mutant FLT3 and B cell acute lymphoblastic leukemia (normal and amplification of FLT3 cell lines. Furthermore, using stable isotope labeling by amino acids in cell culture (SILAC, we were able to quantified over 400 phosphorylation sites (pTyr, pSer, and pThr that were responsive to FLT3 inhibition in FLT3 driven human leukemia cell lines. We also extended this phosphoproteomic analysis on bone marrow from primary AML patient samples, and identify over 200 tyrosine and 800 serine/threonine phosphorylation sites in vivo. This study showed that oncogenic FLT3 regulates proteins involving diverse cellular processes and affects multiple signaling pathways in human leukemia that we previously appreciated, such as Fc epsilon RI-mediated signaling, BCR, and CD40 signaling pathways. It provides a valuable resource for investigation of oncogenic FLT3 signaling in human leukemia.

  15. Physical parameters activating electrical signal distortions in polluted soils

    Directory of Open Access Journals (Sweden)

    R. Angelini

    2002-06-01

    Full Text Available Laboratory investigations and field measurements show that the electrical behaviour of polluted soils is strongly non-linear at low frequencies. This phenomenon can be related to the class and the amount of pollutants. To measure this non-linearity, we used only monochromatic voltage waveform as input signal and analysed the current signals at first by means of the classical spectral analysis. In particular, the Total Harmonic Distortion % (THD% and the Harmonic Distortion %(? measure the non-linearity level and identify the frequency interval where the non-linear electrical behaviour is activated. This frequency interval can be related to the pollutant molecular size. Open interpretative problems were the following: 1 phase localization of the signal deformation; 2 «local» amplitude of the applied signal activating the distortion, and 3 numerical fit of the distortion. We employed the wavelet analysis to study the phenomenon. The wavelet technique breaks up a signal into shifted and scaled versions of the original wavelet, which is a waveform of limited duration. These features of the wavelets allow us to obtain current components that can be interpreted on the bases of a real physical meaning. By using the wavelet analysis, we obtained the phase localization of the ‘oscillations’ of the details and consequently the phase and amplitude of the applied signal. The sum of nine details provides a good numerical fit of the distorted signal. Starting from the wavelet analysis, we determined the physical conditions activating each distortion, testing some parameters on experimental data. The parameters that resulted most significant are the phase ? of the distortion activation and the product Vin?t (Vs (where ?t is the time interval corresponding to the said ? and Vin is the integral tension applied to the sample on ?t. The latter parameter is in a very good agreement with field data of Advanced Monochromatic Spectral Induced Polarization (AMSIP

  16. BMP2 Transfer to Neighboring Cells and Activation of Signaling.

    Science.gov (United States)

    Alborzinia, Hamed; Shaikhkarami, Marjan; Hortschansky, Peter; Wölfl, Stefan

    2016-09-01

    Morphogen gradients and concentration are critical features during early embryonic development and cellular differentiation. Previously we reported the preparation of biologically active, fluorescently labeled BMP2 and quantitatively analyzed their binding to the cell surface and followed BMP2 endocytosis over time on the level of single endosomes. Here we show that this internalized BMP2 can be transferred to neighboring cells and, moreover, also activates downstream BMP signaling in adjacent cells, indicated by Smad1/5/8 phosphorylation and activation of the downstream target gene id1. Using a 3D matrix to modulate cell-cell contacts in culture we could show that direct cell-cell contact significantly increased BMP2 transfer. Using inhibitors of vesicular transport, transfer was strongly inhibited. Interestingly, cotreatment with the physiological BMP inhibitor Noggin increased BMP2 uptake and transfer, albeit activation of Smad signaling in neighboring cells was completely suppressed. Our findings present a novel and interesting mechanism by which morphogens such as BMP2 can be transferred between cells and how this is modulated by BMP antagonists such as Noggin, and how this influences activation of Smad signaling by BMP2 in neighboring cells. PMID:27306974

  17. ATP release and purinergic signaling in NLRP3 inflammasome activation

    Directory of Open Access Journals (Sweden)

    Isabelle eCOUILLIN

    2013-01-01

    Full Text Available The NLRP3 inflammasome is a protein complex involved in IL-1β and IL-18 processing that senses pathogen- and danger-associated molecular patterns. One step- or two step- models have been proposed to explain the tight regulation of IL-1β production during inflammation. Moreover, cellular stimulation triggers ATP release and subsequent activation of purinergic receptors at the cell surface. Importantly some studies have reported roles for extracellular ATP (eATP, in NLRP3 inflammasome activation in response to PAMPs and DAMPs. In this mini review, we will discuss the link between active ATP release, purinergic signaling and NLRP3 inflammasome activation. We will focus on the role of autocrine or paracrine ATP export in particle-induced NLRP3 inflammasome activation and discuss how particle activators are competent to induce maturation and secretion of IL-1β through a process that involves, as a first event, extracellular release of endogenous ATP through hemichannel opening, and as a second event, signaling through purinergic receptors that trigger NLRP3 inflammasome activation. Finally, we will review the evidence for ATP as a key proinflammatory mediator released by dying cells. In particular we will discuss how cancer cells dying via autophagy trigger ATP-dependent NLRP3 inflammasome activation in the macrophages engulfing them, eliciting an immunogenic response against tumors.

  18. Chemokines: a new dendritic cell signal for T cell activation

    Directory of Open Access Journals (Sweden)

    Christoph A Thaiss

    2011-08-01

    Full Text Available Dendritic cells (DCs are the main inducers and regulators of cytotoxic T lymphocyte (CTL responses against viruses and tumors. One checkpoint to avoid misguided CTL activation, which might damage healthy cells of the body, is the necessity for multiple activation signals, involving both antigenic as well as additional signals that reflect the presence of pathogens. DCs provide both signals when activated by ligands of pattern recognition receptors and licensed by helper lymphocytes. Recently, it has been established that such T cell licensing can be facilitated by CD4+ T helper cells (classical licensing or by NKT cells (alternative licensing. Licensing regulates the DC/CTL cross-talk at multiple layers. Direct recruitment of CTLs through chemokines released by licensed DCs has recently emerged as a common theme and has a crucial impact on the efficiency of CTL responses. Here, we discuss recent advances in our understanding of DC licensing for cross-priming and implications for the temporal and spatial regulation underlying this process. Future vaccination strategies will benefit from a deeper insight into the mechanisms that govern CTL activation.

  19. Activation and signaling of the p38 MAP kinase pathway

    Institute of Scientific and Technical Information of China (English)

    Tyler ZARUBIN; Jiahuai HAN

    2005-01-01

    The family members of the mitogen-activated protein (MAP) kinases mediate a wide variety of cellular behaviors in response to extracellular stimuli. One of the four main sub-groups, the p38 group of MAP kinases, serve as a nexus for signal transduction and play a vital role in numerous biological processes. In this review, we highlight the known characteristics and components of the p38 pathway along with the mechanism and consequences of p38 activation. We focus on the role of p38 as a signal transduction mediator and examine the evidence linking p38 to inflammation, cell cycle, cell death, development, cell differentiation, senescence and tumorigenesis in specific cell types. Upstream and downstream components of p38 are described and questions remaining to be answered are posed. Finally, we propose several directions for future research on p38.

  20. Artifact suppression and analysis of brain activities with electroencephalography signals

    Institute of Scientific and Technical Information of China (English)

    Md. Rashed-Al-Mahfuz; Md. Rabiul Islam; Keikichi Hirose; Md. Khademul Islam Molla

    2013-01-01

    Brain-computer interface is a communication system that connects the brain with computer (or other devices) but is not dependent on the normal output of the brain (i.e., peripheral nerve and muscle). Electro-oculogram is a dominant artifact which has a significant negative influence on further analysis of real electroencephalography data. This paper presented a data adaptive technique for artifact suppression and brain wave extraction from electroencephalography signals to detect regional brain activities. Empirical mode decomposition based adaptive thresholding approach was employed here to suppress the electro-oculogram artifact. Fractional Gaussian noise was used to determine the threshold level derived from the analysis data without any training. The purified electroencephalography signal was composed of the brain waves also called rhythmic components which represent the brain activities. The rhythmic components were extracted from each electroencephalography channel using adaptive wiener filter with the original scale. The regional brain activities were mapped on the basis of the spatial distribution of rhythmic components, and the results showed that different regions of the brain are activated in response to different stimuli. This research analyzed the activities of a single rhythmic component, alpha with respect to different motor imaginations. The experimental results showed that the proposed method is very efficient in artifact suppression and identifying individual motor imagery based on the activities of alpha component.

  1. 76 FR 22745 - Three Notch Railway, LLC-Acquisition and Operation Exemption-Three Notch Railroad Co., Inc.

    Science.gov (United States)

    2011-04-22

    ... Surface Transportation Board Three Notch Railway, LLC--Acquisition and Operation Exemption-- Three Notch Railroad Co., Inc. Three Notch Railway, LLC (TNRW), a noncarrier, has filed a verified notice of exemption under 49 CFR 1150.31 to acquire from Three Notch Railroad Co., Inc. (TNHR) and to operate...

  2. Chemical Signaling and Functional Activation in Colloidosome-Based Protocells.

    Science.gov (United States)

    Sun, Shiyong; Li, Mei; Dong, Faqin; Wang, Shengjie; Tian, Liangfei; Mann, Stephen

    2016-04-01

    An aqueous-based microcompartmentalized model involving the integration of partially hydrophobic Fe(III)-rich montmorillonite (FeM) clay particles as structural and catalytic building blocks for colloidosome membrane assembly, self-directed membrane remodeling, and signal-induced protocell communication is described. The clay colloidosomes exhibit size- and charge-selective permeability, and show dual catalytic functions involving spatially confined enzyme-mediated dephosphorylation and peroxidase-like membrane activity. The latter is used for the colloidosome-mediated synthesis and assembly of a temperature-responsive poly(N-isopropylacrylamide)(PNIPAM)/clay-integrated hybrid membrane. In situ PNIPAM elaboration of the membrane is coupled to a glucose oxidase (GOx)-mediated signaling pathway to establish a primitive model of chemical communication and functional activation within a synthetic "protocell community" comprising a mixed population of GOx-containing silica colloidosomes and alkaline phosphatase (ALP)-containing FeM-clay colloidosomes. Triggering the enzyme reaction in the silica colloidosomes gives a hydrogen peroxide signal that induces polymer wall formation in a coexistent population of the FeM-clay colloidosomes, which in turn generates self-regulated membrane-gated ALP-activity within the clay microcompartments. The emergence of new functionalities in inorganic colloidosomes via chemical communication between different protocell populations provides a first step toward the realization of interacting communities of synthetic functional microcompartments. PMID:26923794

  3. Wnt signaling activates Shh signaling in early postnatal intervertebral discs, and re-activates Shh signaling in old discs in the mouse.

    Directory of Open Access Journals (Sweden)

    Tamara Winkler

    Full Text Available Intervertebral discs (IVDs are strong fibrocartilaginous joints that connect adjacent vertebrae of the spine. As discs age they become prone to failure, with neurological consequences that are often severe. Surgical repair of discs treats the result of the disease, which affects as many as one in seven people, rather than its cause. An ideal solution would be to repair degenerating discs using the mechanisms of their normal differentiation. However, these mechanisms are poorly understood. Using the mouse as a model, we previously showed that Shh signaling produced by nucleus pulposus cells activates the expression of differentiation markers, and cell proliferation, in the postnatal IVD. In the present study, we show that canonical Wnt signaling is required for the expression of Shh signaling targets in the IVD. We also show that Shh and canonical Wnt signaling pathways are down-regulated in adult IVDs. Furthermore, this down-regulation is reversible, since re-activation of the Wnt or Shh pathways in older discs can re-activate molecular markers of the IVD that are lost with age. These data suggest that biological treatments targeting Wnt and Shh signaling pathways may be feasible as a therapeutic for degenerative disc disease.

  4. TNF inhibits Notch-1 in skeletal muscle cells by Ezh2 and DNA methylation mediated repression: implications in duchenne muscular dystrophy.

    Directory of Open Access Journals (Sweden)

    Swarnali Acharyya

    Full Text Available BACKGROUND: Classical NF-kappaB signaling functions as a negative regulator of skeletal myogenesis through potentially multiple mechanisms. The inhibitory actions of TNFalpha on skeletal muscle differentiation are mediated in part through sustained NF-kappaB activity. In dystrophic muscles, NF-kappaB activity is compartmentalized to myofibers to inhibit regeneration by limiting the number of myogenic progenitor cells. This regulation coincides with elevated levels of muscle derived TNFalpha that is also under IKKbeta and NF-kappaB control. METHODOLOGY/PRINCIPAL FINDINGS: Based on these findings we speculated that in DMD, TNFalpha secreted from myotubes inhibits regeneration by directly acting on satellite cells. Analysis of several satellite cell regulators revealed that TNFalpha is capable of inhibiting Notch-1 in satellite cells and C2C12 myoblasts, which was also found to be dependent on NF-kappaB. Notch-1 inhibition occurred at the mRNA level suggesting a transcriptional repression mechanism. Unlike its classical mode of action, TNFalpha stimulated the recruitment of Ezh2 and Dnmt-3b to coordinate histone and DNA methylation, respectively. Dnmt-3b recruitment was dependent on Ezh2. CONCLUSIONS/SIGNIFICANCE: We propose that in dystrophic muscles, elevated levels of TNFalpha and NF-kappaB inhibit the regenerative potential of satellite cells via epigenetic silencing of the Notch-1 gene.

  5. Influences of LIN-12/Notch and POP-1/TCF on the Robustness of Ventral Uterine Cell Fate Specification in Caenorhabditis elegans Gonadogenesis.

    Science.gov (United States)

    Sallee, Maria D; Aydin, Taner; Greenwald, Iva

    2015-10-19

    The prospective ventral uterus of the hermaphrodite gonad primordium consists of two pairs of sister cells, with each pair consisting of a proximal "α" cell and a distal "β" cell. All four cells initially are competent to become the anchor cell (AC), a unique cell type that acts as the organizer of subsequent uterine and vulval development. However, the β cells soon lose this competence and always become ventral uterine precursor cells (VUs), whereas the α cells maintain their AC competence longer, until lin-12/Notch-mediated interactions between them specify one as the AC and the other as a VU. Here, we investigate this asymmetry in developmental potential and VU fate specification between the α and β sister cells. We find evidence that lin-12 activity contributes to the robustness of βVU fate at elevated temperature, that the Caenorhabditis elegans Notch paralog glp-1 is not functionally redundant with lin-12 in specifying βVU fate, and that the activity of POP-1, the sole C. elegans TCF ortholog, influences βVU fate. We propose a model for how Wnt and LIN-12/Notch signaling together lead to robust specification of the βVU fate.

  6. Buyang Huanwu decoction up-regulatesNotch1 gene expression in injured spinal cord

    Institute of Scientific and Technical Information of China (English)

    Zhan-peng Guo; Mi-na Huang; An-qi Liu; Ya-jiang Yuan; Jian-bo Zhao; Xi-fan Mei

    2015-01-01

    Expression of genes in the Notch signaling pathway is altered in the injured spinal cord, which indicates thatNotch participates in repair after spinal cord injury.Buyang Huanwu decoction, a traditional Chinese herbal preparation, can promote the growth of nerve cells and nerve ifbers;however, it is unclear whetherBuyang 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/mLBuyang Huanwu decoction daily until sacriifce. Real-time reverse transcription polymerase chain reaction analysis demonstrated that at 7, 14 and 28 days after injury, the expression ofNotch1 was increased in the Buyang Huanwu decoction group compared with controls. These ifndings conifrm thatBuyang 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.

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

    Science.gov (United States)

    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.

  8. Anti Deceptive Jamming for MIMO Radar Based on Data Fusion and Notch Filtering (in English

    Directory of Open Access Journals (Sweden)

    Li Wei

    2013-08-01

    Full Text Available Deceptive jamming can get vivid jamming effect on Multiple-Input Multiple-Output (MIMO radar with very low power. In order to remove those deceptive targets, one method based on signal jittering, data fusion and fake target notch filtering is proposed in this paper. Multiple orthogonal binary phase codes are used as transmitted signals, before each time of transmission each transmitter will choose one signal from all the orthogonal codes, images of echoes of all kinds of codes are detected with constant false alarm rate. Targets detected in images of echoes of all different signals are fused to determine to be real or not, fake targets will be nulled by notch filtering in the image, therefore, weak real targets can be detected in the next round of detection, in this way fusion and notch filtering are implemented again and again until no fake targets exist. The effect of deceptive jamming on radar will be removed completely. Simulation result testifies that the method based on signal jittering, data fusion and notch filtering can help MIMO radar remove deceptive jamming completely.

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

    Science.gov (United States)

    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

  10. Regularized Adaptive Notch Filters for Acoustic Howling Suppression

    DEFF Research Database (Denmark)

    Gil-Cacho, Pepe; van Waterschoot, Toon; Moonen, Marc;

    2009-01-01

    In this paper, a method for the suppression of acoustic howling is developed, based on adaptive notch filters (ANF) with regularization (RANF). The method features three RANFs working in parallel to achieve frequency tracking, howling detection and suppression. The ANF-based approach to howling...... components in the source signal are not affected. The RANFs proposed in this paper are implemented in direct form and are updated using a gradient descent type algorithm. Results show that, under certain conditions, the level of suppression and sound quality is similar to what is obtained with frame...

  11. Disentangling stellar activity from exoplanetary signals with interferometry

    Directory of Open Access Journals (Sweden)

    Ligi Roxanne

    2015-01-01

    Full Text Available Stellar activity can express as many forms at stellar surfaces: dark spots, convective cells, bright plages. Particularly, dark spots and bright plages add noise on photometric data or radial velocity measurements used to detect exoplanets, and thus lead to false detection or disrupt their derived parameters. Since interferometry provides a very high angular resolution, it may constitute an interesting solution to distinguish the signal of a transiting exoplanet and that of stellar activity. It has also been shown that granulation adds bias in visibility and closure phase measurements, affecting in turn the derived stellar parameters. We analyze the noises generated by dark spots on interferometric observables and compare them to exoplanet signals. We investigate the current interferometric instruments able to measure and disentangle these signals, and show that there is a lack in spatial resolution. We thus give a prospective of the improvements to be brought on future interferometers, which would also significantly extend the number of available targets.

  12. Infraglenoidal scapular notching in reverse total shoulder replacement: a prospective series of 60 cases and systematic review of the literature

    Directory of Open Access Journals (Sweden)

    Hochreiter Josef

    2011-05-01

    Full Text Available Abstract Background The impact of infraglenoidal scapular notching in reversed total shoulder arthroplasty (RTSA is still controversially discussed. Our goal was to evaluate its potential influence on subjective shoulder stability and clinical outcome. We hypothesized that subjective instability and clinical outcome after implantation of RTSA correlates with objective scapular notching. Methods Sixty shoulders were assessed preoperatively and at minimum 2-year follow-up for active range of motion and by use of the Oxford instability score, Rowe score for instability, Constant score for pain, Constant shoulder score, DASH score. All shoulders were evaluated on anterior-posterior and axillary lateral radiographic views. These X-ray scans were classified twice by two orthopaedic surgeons with respect to infraglenoidal scapular notching according to the classification of Nerot. Notching was tested for correlation with clinical outcome scores to the evaluated notching. Results We found no significant correlation between infraglenoidal scapular notching and clinical outcomes after a mid-term follow-up from 24 to 60 months, but at the final follow-up of 60 months and more, we did see statistically significant, positive correlations between infraglenoidal scapular notching and the Constant pain score as well as active range of motion. At mean follow-up of 42 months (range from 24 to 96 months we found no significant correlation between subjective instability and infraglenoidal scapular notching. Conclusions We conclude that patients' subjective impression on their shoulders' stability is not correlating with radiological signs of infraglenoidal scapular notching. Nevertheless clinical parameters are affected by infraglenoidal scapular notching, at least in the long term

  13. Signal integration by Ca2+ regulates intestinal stem cell activity

    Science.gov (United States)

    Deng, Hansong; Gerencser, Akos A.; Jasper, Heinrich

    2015-01-01

    Summary Somatic stem cells (SCs) maintain tissue homeostasis by dynamically adjusting proliferation and differentiation in response to stress and metabolic cues. Here, we identify Ca2+ signaling as a central regulator of intestinal SC (ISC) activity in Drosophila. We find that dietary L-glutamate stimulates ISC division and gut growth. The metabotropic glutamate receptor (mGluR) is required in ISCs for this response and for an associated modulation of cytosolic Ca2+ oscillations that results in sustained high cytosolic Ca2+ concentrations. High cytosolic Ca2+ induces ISC proliferation by regulating Calcineurin and CREB - regulated transcriptional co-activator (CRTC). In response to a wide range of dietary and stress stimuli, ISCs reversibly transition between Ca2+ oscillation states that represent poised or activated modes of proliferation, respectively. We propose that the dynamic regulation of intracellular Ca2+ levels allows effective integration of diverse mitogenic signals in ISCs to tailor their proliferative activity to the needs of the tissue. PMID:26633624

  14. Mutual inactivation of Notch receptors and ligands facilitates developmental patterning.

    Directory of Open Access Journals (Sweden)

    David Sprinzak

    2011-06-01

    Full Text Available Developmental patterning requires juxtacrine signaling in order to tightly coordinate the fates of neighboring cells. Recent work has shown that Notch and Delta, the canonical metazoan juxtacrine signaling receptor and ligand, mutually inactivate each other in the same cell. This cis-interaction generates mutually exclusive sending and receiving states in individual cells. It generally remains unclear, however, how this mutual inactivation and the resulting switching behavior can impact developmental patterning circuits. Here we address this question using mathematical modeling in the context of two canonical pattern formation processes: boundary formation and lateral inhibition. For boundary formation, in a model motivated by Drosophila wing vein patterning, we find that mutual inactivation allows sharp boundary formation across a broader range of parameters than models lacking mutual inactivation. This model with mutual inactivation also exhibits robustness to correlated gene expression perturbations. For lateral inhibition, we find that mutual inactivation speeds up patterning dynamics, relieves the need for cooperative regulatory interactions, and expands the range of parameter values that permit pattern formation, compared to canonical models. Furthermore, mutual inactivation enables a simple lateral inhibition circuit architecture which requires only a single downstream regulatory step. Both model systems show how mutual inactivation can facilitate robust fine-grained patterning processes that would be difficult to implement without it, by encoding a difference-promoting feedback within the signaling system its