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Sample records for sustained wnt pathway

  1. Wnt signalling pathway parameters for mammalian cells.

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    Chin Wee Tan

    Full Text Available Wnt/β-catenin signalling regulates cell fate, survival, proliferation and differentiation at many stages of mammalian development and pathology. Mutations of two key proteins in the pathway, APC and β-catenin, have been implicated in a range of cancers, including colorectal cancer. Activation of Wnt signalling has been associated with the stabilization and nuclear accumulation of β-catenin and consequential up-regulation of β-catenin/TCF gene transcription. In 2003, Lee et al. constructed a computational model of Wnt signalling supported by experimental data from analysis of time-dependent concentration of Wnt signalling proteins in Xenopus egg extracts. Subsequent studies have used the Xenopus quantitative data to infer Wnt pathway dynamics in other systems. As a basis for understanding Wnt signalling in mammalian cells, a confocal live cell imaging measurement technique is developed to measure the cell and nuclear volumes of MDCK, HEK293T cells and 3 human colorectal cancer cell lines and the concentrations of Wnt signalling proteins β-catenin, Axin, APC, GSK3β and E-cadherin. These parameters provide the basis for formulating Wnt signalling models for kidney/intestinal epithelial mammalian cells. There are significant differences in concentrations of key proteins between Xenopus extracts and mammalian whole cell lysates. Higher concentrations of Axin and lower concentrations of APC are present in mammalian cells. Axin concentrations are greater than APC in kidney epithelial cells, whereas in intestinal epithelial cells the APC concentration is higher than Axin. Computational simulations based on Lee's model, with this new data, suggest a need for a recalibration of the model.A quantitative understanding of Wnt signalling in mammalian cells, in particular human colorectal cancers requires a detailed understanding of the concentrations of key protein complexes over time. Simulations of Wnt signalling in mammalian cells can be initiated

  2. Wnt/beta-catenin pathway: modulating anticancer immune response

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    Sachin Gopalkrishna Pai

    2017-05-01

    Full Text Available Abstract Wnt/β-catenin signaling, a highly conserved pathway through evolution, regulates key cellular functions including proliferation, differentiation, migration, genetic stability, apoptosis, and stem cell renewal. The Wnt pathway mediates biological processes by a canonical or noncanonical pathway, depending on the involvement of β-catenin in signal transduction. β-catenin is a core component of the cadherin protein complex, whose stabilization is essential for the activation of Wnt/β-catenin signaling. As multiple aberrations in this pathway occur in numerous cancers, WNT-directed therapy represents an area of significant developmental therapeutics focus. The recently described role of Wnt/β-catenin pathway in regulating immune cell infiltration of the tumor microenvironment renewed the interest, given its potential impact on responses to immunotherapy treatments. This article summarizes the role of Wnt/β-catenin pathway in cancer and ongoing therapeutic strategies involving this pathway.

  3. Wnt pathway in Dupuytren disease : connecting profibrotic signals

    NARCIS (Netherlands)

    Van Beuge, Marike M.; Ten Dam, Evert-Jan P. M.; Werker, Paul M. N.; Bank, Ruud A.

    2015-01-01

    A role of Wnt signaling in Dupuytren disease, a fibroproliferative disease of the hand and fingers, has not been fully elucidated. We examined a large set of Wnt pathway components and signaling targets and found significant dysregulation of 41 Wnt-related genes in tissue from the Dupuytren nodules

  4. Wnt pathway in Dupuytren disease: connecting profibrotic signals.

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    van Beuge, Marike M; Ten Dam, Evert-Jan P M; Werker, Paul M N; Bank, Ruud A

    2015-12-01

    A role of Wnt signaling in Dupuytren disease, a fibroproliferative disease of the hand and fingers, has not been fully elucidated. We examined a large set of Wnt pathway components and signaling targets and found significant dysregulation of 41 Wnt-related genes in tissue from the Dupuytren nodules compared with patient-matched control tissue. A large proportion of genes coding for Wnt proteins themselves was downregulated. However, both canonical Wnt targets and components of the noncanonical signaling pathway were upregulated. Immunohistochemical analysis revealed that protein expression of Wnt1-inducible secreted protein 1 (WISP1), a known Wnt target, was increased in nodules compared with control tissue, but knockdown of WISP1 using small interfering RNA (siRNA) in the Dupuytren myofibroblasts did not confirm a functional role. The protein expression of noncanonical pathway components Wnt5A and VANGL2 as well as noncanonical coreceptors Ror2 and Ryk was increased in nodules. On the contrary, the strongest downregulated genes in this study were 4 antagonists of Wnt signaling (DKK1, FRZB, SFRP1, and WIF1). Downregulation of these genes in the Dupuytren tissue was mimicked in vitro by treating normal fibroblasts with transforming growth factor β1 (TGF-β1), suggesting cross talk between different profibrotic pathways. Furthermore, siRNA-mediated knockdown of these antagonists in normal fibroblasts led to increased nuclear translocation of Wnt target β-catenin in response to TGF-β1 treatment. In conclusion, we have shown extensive dysregulation of Wnt signaling in affected tissue from Dupuytren disease patients. Components of both the canonical and the noncanonical pathways are upregulated, whereas endogenous antagonists are downregulated, possibly via interaction with other profibrotic pathways. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Roles of Wnt pathway genes wls, wnt9a, wnt5b, frzb and gpc4 in regulating convergent-extension during zebrafish palate morphogenesis.

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    Rochard, Lucie; Monica, Stefanie D; Ling, Irving T C; Kong, Yawei; Roberson, Sara; Harland, Richard; Halpern, Marnie; Liao, Eric C

    2016-07-15

    The Wnt signaling pathway is crucial for tissue morphogenesis, participating in cellular behavior changes, notably during the process of convergent-extension. Interactions between Wnt-secreting and receiving cells during convergent-extension remain elusive. We investigated the role and genetic interactions of Wnt ligands and their trafficking factors Wls, Gpc4 and Frzb in the context of palate morphogenesis in zebrafish. We describe that the chaperon Wls and its ligands Wnt9a and Wnt5b are expressed in the ectoderm, whereas juxtaposed chondrocytes express Frzb and Gpc4. Using wls, gpc4, frzb, wnt9a and wnt5b mutants, we genetically dissected the Wnt signals operating between secreting ectoderm and receiving chondrocytes. Our analysis delineates that non-canonical Wnt signaling is required for cell intercalation, and that wnt5b and wnt9a are required for palate extension in the anteroposterior and transverse axes, respectively. © 2016. Published by The Company of Biologists Ltd.

  6. Wnt Signaling Pathway and Its Significance for Melanoma Development

    OpenAIRE

    Kulikova К.V.; Kibardin А.V.; Gnuchev N.V.; Georgiev G.P.; Larin S.S.

    2012-01-01

    Melanoma is characterized by its high metastatic propensity. Melanoma metastasis is associated with an activation of signaling pathways that are responsible for embryogenesis. Wnt signaling pathway is considered as one of the key signaling cascades, whose aberrant activation results in melanoma development. Wnt signaling includes a complex network of intracellular interactions. Its ligands are able to initiate at least three signal transduction pathways: canonical and two noncanonical. Accord...

  7. Canonical WNT signaling pathway and human AREG.

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    Katoh, Yuriko; Katoh, Masaru

    2006-06-01

    AREG (Amphiregulin), BTC (beta-cellulin), EGF, EPGN (Epigen), EREG (Epiregulin), HBEGF, NRG1, NRG2, NRG3, NRG4 and TGFA (TGFalpha) constitute EGF family ligands for ERBB family receptors. Cetuximab (Erbitux), Pertuzumab (Omnitarg) and Trastuzumab (Herceptin) are anti-cancer drugs targeted to EGF family ligands, while Gefitinib (Iressa), Erlotinib (Tarceva) and Lapatinib (GW572016) are anti-cancer drugs targeted to ERBB family receptors. AREG and TGFA are biomarkers for Gefitinib non-responders. The TCF/LEF binding sites within the promoter region of human EGF family members were searched for by using bioinformatics and human intelligence (Humint). Because three TCF/LEF-binding sites were identified within the 5'-promoter region of human AREG gene, comparative genomics analyses on AREG orthologs were further performed. The EPGN-EREG-AREG-BTC cluster at human chromosome 4q13.3 was linked to the PPBP-CXCL segmental duplicons. AREG was the paralog of HBEGF at human chromosome 5q31.2. Chimpanzee AREG gene, consisting of six exons, was located within NW_105918.1 genome sequence. Chimpanzee AREG was a type I transmembrane protein showing 98.0% and 71.4% total amino-acid identity with human AREG and mouse Areg, respectively. Three TCF/LEF-binding sites within human AREG promoter were conserved in chimpanzee AREG promoter, but not in rodent Areg promoters. Primate AREG promoters were significantly divergent from rodent Areg promoters. AREG mRNA was expressed in a variety of human tumors, such as colorectal cancer, liver cancer, gastric cancer, breast cancer, prostate cancer, esophageal cancer and myeloma. Because human AREG was characterized as potent target gene of WNT/beta-catenin signaling pathway, WNT signaling activation could lead to Gefitinib resistance through AREG upregulation. AREG is a target of systems medicine in the field of oncology.

  8. Role of the Wnt pathway in thyroid cancer

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    Ana eSastre-Perona

    2012-02-01

    Full Text Available Aberrant activation of Wnt signaling is involved in the development of several epithelial tumors. Wnt signaling includes two major pathways (i the canonical or Wnt/βcatenin pathway and (ii the non-canonicals pathways, which do not involve βcatenin stabilization. Among these pathways, the Wnt/βcatenin pathway has received most attention during the past years for its critical role in cancer. A number of publications emphasize its role in thyroid cancer. Wnt signaling plays a crucial role in development and epithelial renewal, and components such as βcatenin and Axin are often mutated in thyroid cancer. Although it is accepted that alteration of Wnt signaling is a late event in thyroid cell transformation that affects anaplastic thyroid tumors, recent data also suggest its alteration in papillary thyroid carcinoma with RET/PTC mutations. Therefore, the purpose of this review is to summarize the main relevant data of Wnt/βcatenin signaling in thyroid cancer.

  9. Targeting the Wnt/β-catenin pathway in primary ovarian cancer with the porcupine inhibitor WNT974.

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    Boone, Jonathan D; Arend, Rebecca C; Johnston, Bobbi E; Cooper, Sara J; Gilchrist, Scott A; Oelschlager, Denise K; Grizzle, William E; McGwin, Gerald; Gangrade, Abhishek; Straughn, J Michael; Buchsbaum, Donald J

    2016-02-01

    Preclinical studies in ovarian cancer have demonstrated upregulation of the Wnt/β-catenin pathway promoting tumor proliferation and chemoresistance. Our objective was to evaluate the effect of the Wnt/β-catenin pathway inhibitor, WNT974, in primary ovarian cancer ascites cells. Ascites cells from patients with papillary serous ovarian cancer were isolated and treated with 1 μM WNT974±100 μM carboplatin. Viability was evaluated with the ATPlite assay. The IC50 was calculated using a dose-response analysis. Immunohistochemistry (IHC) was performed on ascites cells and tumor. Expression of R-spondin 2 (RSPO2), RSPO3, PORCN, WLS, AXIN2, and three previously characterized RSPO fusion transcripts were assessed using Taqman assays. Sixty ascites samples were analyzed for response to WNT974. The ascites samples that showed a decrease in ATP concentration after treatment demonstrated no difference from the untreated cells in percent viability with trypan blue staining. Flow cytometry demonstrated fewer cells in the G2 phase and more in the G1 and S phases after treatment with WNT974. Combination therapy with WNT974 and carboplatin resulted in a higher percentage of samples that showed ≥30% reduction in ATP concentration than either single drug treatment. IHC analysis of Wnt pathway proteins suggests cell cycle arrest rather than cytotoxicity after WNT974 treatment. QPCR indicated that RSPO fusions are not prevalent in ovarian cancer tissues or ascites. However, higher PORCN expression correlated to sensitivity to WNT974 (P=0.0073). In conclusion, WNT974 produces cytostatic effects in patient ascites cells with primary ovarian cancer through inhibition of the Wnt/β-catenin pathway. The combination of WNT974 and carboplatin induces cytotoxicity plus cell cycle arrest in a higher percentage of ascites samples than with single drug treatment. RSPO fusions do not contribute to WNT974 sensitivity; however, higher PORCN expression indicates increased WNT974 sensitivity.

  10. Niclosamide suppresses hepatoma cell proliferation via the Wnt pathway

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    Tomizawa M

    2013-11-01

    Full Text Available Minoru Tomizawa,1 Fuminobu Shinozaki,2 Yasufumi Motoyoshi,3 Takao Sugiyama,4 Shigenori Yamamoto,5 Makoto Sueishi,4 Takanobu Yoshida6 1Department of Gastroenterology, 2Department of Radiology, 3Department of Neurology, 4Department of Rheumatology, 5Department of Pediatrics, 6Department of Internal Medicine, National Hospital Organization Shimoshizu Hospital, Yotsukaido City, Chiba, Japan Background: The Wnt pathway plays an important role in hepatocarcinogenesis. We analyzed the association of the Wnt pathway with the proliferation of hepatoma cells using Wnt3a and niclosamide, a drug used to treat tapeworm infection. Methods: We performed an MTS assay to determine whether Wnt3a stimulated proliferation of Huh-6 and Hep3B human hepatoma cell lines after 72 hours of incubation with Wnt3a in serum-free medium. The cells were subjected to hematoxylin and eosin staining and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL after 48 hours of incubation. RNA was isolated 48 hours after addition of Wnt3a or niclosamide, and cyclin D1 expression levels were analyzed by real-time quantitative polymerase chain reaction. The promoter activity of T-cell factor was analyzed by luciferase assay 48 hours after transfection of TOPflash. Western blot analysis was performed with antibodies against β-catenin, dishevelled 2, and cyclin D1. Results: Cell proliferation increased with Wnt3a. Niclosamide suppressed proliferation with or without Wnt3a. Hematoxylin and eosin and TUNEL staining suggested that apoptosis occurred in cells with niclosamide. Cyclin D1 was upregulated in the presence of Wnt3a and downregulated with addition of niclosamide. The promoter activity of T-cell factor increased with Wnt3a, whereas T-cell factor promoter activity decreased with niclosamide. Western blot analysis showed that Wnt3a upregulated β-catenin, dishevelled 2, and cyclin D1, while niclosamide downregulated them. Conclusion: Niclosamide is a potential

  11. ASPM regulates Wnt signaling pathway activity in the developing brain.

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    Buchman, Joshua J; Durak, Omer; Tsai, Li-Huei

    2011-09-15

    Autosomal recessive primary microcephaly (MCPH) is a neural developmental disorder in which patients display significantly reduced brain size. Mutations in Abnormal Spindle Microcephaly (ASPM) are the most common cause of MCPH. Here, we investigate the underlying functions of Aspm in brain development and find that Aspm expression is critical for proper neurogenesis and neuronal migration. The Wnt signaling pathway is known for its roles in embryogenesis, and genome-wide siRNA screens indicate that ASPM is a positive regulator of Wnt signaling. We demonstrate that knockdown of Aspm results in decreased Wnt-mediated transcription, and that expression of stabilized β-catenin can rescue this deficit. Finally, coexpression of stabilized β-catenin can rescue defects observed upon in vivo knockdown of Aspm. Our findings provide an impetus to further explore Aspm's role in facilitating Wnt-mediated neurogenesis programs, which may contribute to psychiatric illness etiology when perturbed.

  12. Advancement of Wnt signal pathway and the target of breast cancer

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    Liang Quan

    2016-01-01

    Full Text Available Wnt/β-catenin signaling has been proved to play an important role in the development and promotion of cancer metastasis. The activation of Wnt signals can lead to duplicating, updating, metastasizing and relapsing. The Wnt signaling pathway is mainly divided into the Wnt/β-catenin pathway and the Wnt/calcium pathway. A better understanding of all the diverse functions of Wnt and their molecular mechanisms has evoked prevailing interest in identifying additional targets related to the Wnt /β-catenin pathways in breast cancer. A number of new target, related to Wnt /β-catenin pathways have been identified in recent years, including NOP14, BKCa channels, Emilin2, WISP, MicroRNAs, NRBP1, TRAF4, and Wntless. In this review, we will introduce the new targets related to the Wnt /β-catenin pathways in breast cancer.

  13. Wnt pathway activation increases hypoxia tolerance during development.

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    Merril Gersten

    Full Text Available Adaptation to hypoxia, defined as a condition of inadequate oxygen supply, has enabled humans to successfully colonize high altitude regions. The mechanisms attempted by organisms to cope with short-term hypoxia include increased ATP production via anaerobic respiration and stabilization of Hypoxia Inducible Factor 1α (HIF-1α. However, less is known about the means through which populations adapt to chronic hypoxia during the process of development within a life time or over generations. Here we show that signaling via the highly conserved Wnt pathway impacts the ability of Drosophila melanogaster to complete its life cycle under hypoxia. We identify this pathway through analyses of genome sequencing and gene expression of a Drosophila melanogaster population adapted over >180 generations to tolerate a concentration of 3.5-4% O2 in air. We then show that genetic activation of the Wnt canonical pathway leads to increased rates of adult eclosion in low O2. Our results indicate that a previously unsuspected major developmental pathway, Wnt, plays a significant role in hypoxia tolerance.

  14. Genome-wide analysis of a Wnt1-regulated transcriptional network implicates neurodegenerative pathways.

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    Wexler, Eric M; Rosen, Ezra; Lu, Daning; Osborn, Gregory E; Martin, Elizabeth; Raybould, Helen; Geschwind, Daniel H

    2011-10-04

    Wnt proteins are critical to mammalian brain development and function. The canonical Wnt signaling pathway involves the stabilization and nuclear translocation of β-catenin; however, Wnt also signals through alternative, noncanonical pathways. To gain a systems-level, genome-wide view of Wnt signaling, we analyzed Wnt1-stimulated changes in gene expression by transcriptional microarray analysis in cultured human neural progenitor (hNP) cells at multiple time points over a 72-hour time course. We observed a widespread oscillatory-like pattern of changes in gene expression, involving components of both the canonical and the noncanonical Wnt signaling pathways. A higher-order, systems-level analysis that combined independent component analysis, waveform analysis, and mutual information-based network construction revealed effects on pathways related to cell death and neurodegenerative disease. Wnt effectors were tightly clustered with presenilin1 (PSEN1) and granulin (GRN), which cause dominantly inherited forms of Alzheimer's disease and frontotemporal dementia (FTD), respectively. We further explored a potential link between Wnt1 and GRN and found that Wnt1 decreased GRN expression by hNPs. Conversely, GRN knockdown increased WNT1 expression, demonstrating that Wnt and GRN reciprocally regulate each other. Finally, we provided in vivo validation of the in vitro findings by analyzing gene expression data from individuals with FTD. These unbiased and genome-wide analyses provide evidence for a connection between Wnt signaling and the transcriptional regulation of neurodegenerative disease genes.

  15. Epilepsy and the Wnt Signaling Pathway

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    2016-09-01

    say, the unique environment of the epilepsy studies converge onto potentially new insights into epileptogenesis with some common underpinnings in... Epigenetic regulation, of which DNA methylation is one type, is prevalent in many diseases. An established epigenetics -based agent is 5-aza-dc...together, set up a pathological environment that sustains seizures. Our observations that excessive glucose usage may contribute suggests that novel

  16. Wnt/β-Catenin Signaling Pathway in Skin Carcinogenesis and Therapy

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    Jing Li

    2015-01-01

    Full Text Available Cooperating with other signaling pathways, Wnt signaling controls cell proliferation, morphology, motility, and embryonic development destination and maintains the homeostasis of tissues including skin, blood, intestine, and brain by regulating somatic stem cells and their niches throughout adult life. Abnormal regulation of Wnt pathways leads to neoplastic proliferation in these tissues. Recent research shows that Wnt signaling is also associated with the regulation of cancer stem cells (CSCs through a similar mechanism to that observed in normal adult stem cells. Thus, the Wnt/β-catenin signaling pathway has been intensively studied and characterized. For this review, we will focus on the regulation of the Wnt/β-catenin signaling pathway in skin cancer. With the important role in stemness and skin CSC proliferation, the Wnt/β-catenin signaling pathway and its elements have the potential to be targets for skin cancer therapy.

  17. Hepatoprotective effect of hesperidin in hepatocellular carcinoma: Involvement of Wnt signaling pathways.

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    Zaghloul, Randa A; Elsherbiny, Nehal M; Kenawy, Hany I; El-Karef, Amr; Eissa, Laila A; El-Shishtawy, Mamdouh M

    2017-09-15

    Wnt3a and Wnt5a are ligands orchestrating the canonical and non-canonical pathways, respectively, with involvement in hepatocellular carcinoma (HCC). Hesperidin (HP) is a natural product found in citrus fruits and reputed for its antitumor activity. The present study aims to investigate the potential hepatoprotective effect of HP against thioacetamide (TAA)-induced HCC focusing on its potential role on Wnt3a and Wnt5a signaling pathways. Forty rats were equally divided into groups; normal control, HP control (receiving HP, 150mg/kg/day), HCC (receiving TAA, 200mg/kg twice weekly for 14weeks) and HP-HCC (receiving HP and TAA). Gene expressions of Wnt3a, Wnt5a, β-catenin and Cyclin D1 were assessed by qPCR, while their protein levels, along with active caspase-3 level, were quantified by ELISA and immunohistochemistry. Liver functions, oxidative stress parameters and myeloperoxidase activity were measured. MTT assay of hepG2 cells treated with recombinant Wnt3a (10ng/ml) in presence or absence of HP (100μM) was performed. HCC group exhibited a significant increase in Wnt3a, β-catenin, Cyclin D1 and Wnt5a gene expressions, as well as, their protein levels. HP significantly prevented TAA-activated Wnt3a/β-catenin and Wnt5a pathways. Moreover, HP exerted hepatoprotective effect by significantly improving the oxidative imbalance, inflammation and liver function parameters, serum ALT, AST activities, and albumin level. Our study is the first to report the possible role of Wnt3a/β-catenin and Wnt5a pathways in TAA-induced early HCC model in rats. HP has a prophylactic effect against hepatocarcinogenesis via preventing the induction of both canonical and non-canonical Wnt pathways. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Wnt-pathway activation in two molecular classes of hepatocellular carcinoma and experimental modulation by sorafenib.

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    Lachenmayer, Anja; Alsinet, Clara; Savic, Radoslav; Cabellos, Laia; Toffanin, Sara; Hoshida, Yujin; Villanueva, Augusto; Minguez, Beatriz; Newell, Philippa; Tsai, Hung-Wen; Barretina, Jordi; Thung, Swan; Ward, Stephen C; Bruix, Jordi; Mazzaferro, Vincenzo; Schwartz, Myron; Friedman, Scott L; Llovet, Josep M

    2012-09-15

    Hepatocellular carcinoma (HCC) is a heterogeneous cancer with active Wnt signaling. Underlying biologic mechanisms remain unclear and no drug targeting this pathway has been approved to date. We aimed to characterize Wnt-pathway aberrations in HCC patients, and to investigate sorafenib as a potential Wnt modulator in experimental models of liver cancer. The Wnt-pathway was assessed using mRNA (642 HCCs and 21 liver cancer cell lines) and miRNA expression data (89 HCCs), immunohistochemistry (108 HCCs), and CTNNB1-mutation data (91 HCCs). Effects of sorafenib on Wnt signaling were evaluated in four liver cancer cell lines with active Wnt signaling and a tumor xenograft model. Evidence for Wnt activation was observed for 315 (49.1%) cases, and was further classified as CTNNB1 class (138 cases [21.5%]) or Wnt-TGFβ class (177 cases [27.6%]). CTNNB1 class was characterized by upregulation of liver-specific Wnt-targets, nuclear β-catenin and glutamine-synthetase immunostaining, and enrichment of CTNNB1-mutation-signature, whereas Wnt-TGFβ class was characterized by dysregulation of classical Wnt-targets and the absence of nuclear β-catenin. Sorafenib decreased Wnt signaling and β-catenin protein in HepG2 (CTNNB1 class), SNU387 (Wnt-TGFβ class), SNU398 (CTNNB1-mutation), and Huh7 (lithium-chloride-pathway activation) cell lines. In addition, sorafenib attenuated expression of liver-related Wnt-targets GLUL, LGR5, and TBX3. The suppressive effect on CTNNB1 class-specific Wnt-pathway activation was validated in vivo using HepG2 xenografts in nude mice, accompanied by decreased tumor volume and increased survival of treated animals. Distinct dysregulation of Wnt-pathway constituents characterize two different Wnt-related molecular classes (CTNNB1 and Wnt-TGFβ), accounting for half of all HCC patients. Sorafenib modulates β-catenin/Wnt signaling in experimental models that harbor the CTNNB1 class signature. ©2012 AACR.

  19. Algebraic Systems Biology: A Case Study for the Wnt Pathway.

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    Gross, Elizabeth; Harrington, Heather A; Rosen, Zvi; Sturmfels, Bernd

    2016-01-01

    Steady-state analysis of dynamical systems for biological networks gives rise to algebraic varieties in high-dimensional spaces whose study is of interest in their own right. We demonstrate this for the shuttle model of the Wnt signaling pathway. Here, the variety is described by a polynomial system in 19 unknowns and 36 parameters. It has degree 9 over the parameter space. This case study explores multistationarity, model comparison, dynamics within regions of the state space, identifiability, and parameter estimation, from a geometric point of view. We employ current methods from computational algebraic geometry, polyhedral geometry, and combinatorics.

  20. Involvement of wnt signaling pathways in the metamorphosis of the bryozoan bugula neritina

    KAUST Repository

    Wong, Yue Him

    2012-03-20

    In this study, we analyzed the metamorphosis of the marine bryozoan Bugula neritina. We observed the morphogenesis of the ancestrula. We defined three distinct pre-ancestrula stages based on the anatomy of the developing polypide and the overall morphology of pre-ancestrula. We then used an annotation based enrichment analysis tool to analyze the B. neritina transcriptome and identified over-representation of genes related to Wnt signaling pathways, suggesting its involvement in metamorphosis. Finally, we studied the temporal-spatial gene expression studies of several Wnt pathway genes. We found that one of the Wnt ligand, BnWnt10, was expressed spatially opposite to the Wnt antagonist BnsFRP within the blastemas, which is the presumptive polypide. Down-stream components of the canonical Wnt signaling pathway were exclusively expressed in the blastemas. Bn?catenin and BnFz5/8 were exclusively expressed in the blastemas throughout the metamorphosis. Based on the genes expression patterns, we propose that BnWnt10 and BnsFRP may relate to the patterning of the polypide, in which the two genes served as positional signals and contributed to the polarization of the blastemas. Another Wnt ligand, BnWnt6, was expressed in the apical part of the pre-ancestrula epidermis. Overall, our findings suggest that the Wnt signaling pathway may be important to the pattern formation of polypide and the development of epidermis. © 2012 Wong et al.

  1. The Wnt/β-catenin pathway is deregulated in cemento-ossifying fibromas.

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    Pereira, Thaís Dos Santos Fontes; Diniz, Marina Gonçalves; França, Josiane Alves; Moreira, Rennan Garcias; Menezes, Grazielle Helena Ferreira de; Sousa, Sílvia Ferreira de; Castro, Wagner Henriques de; Gomes, Carolina Cavaliéri; Gomez, Ricardo Santiago

    2018-02-01

    The molecular pathogenesis of cemento ossifying fibroma (COF) is unclear. The purpose of this study was to investigate mutations in 50 oncogenes and tumor suppressor genes, including APC and CTNNB1, in which mutations in COF have been previously reported. In addition, we assessed the transcriptional levels of the Wnt/β-catenin pathway genes in COF. We used a quantitative polymerase chain reaction array to evaluate the transcriptional levels of 44 Wnt/β-catenin pathway genes in 6 COF samples, in comparison with 6 samples of healthy jaws. By using next-generation sequencing (NGS) in 7 COF samples, we investigated approximately 2800 mutations in 50 genes. The expression assay revealed 12 differentially expressed Wnt/β-catenin pathway genes in COF, including the upregulation of CTNNB1, TCF7, NKD1, and WNT5 A, and downregulation of CTNNBIP1, FRZB, FZD6, RHOU, SFRP4, WNT10 A, WNT3 A, and WNT4, suggesting activation of the Wnt/β-catenin signaling pathway. NGS revealed 5 single nucleotide variants: TP53 (rs1042522), PIK3 CA (rs2230461), MET (rs33917957), KIT (rs3822214), and APC (rs33974176), but none of them was pathogenic. Although NGS detected no oncogenic mutation, deregulation of key Wnt/β-catenin signaling pathway genes appears to be relevant to the molecular pathogenesis of COF. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Role of SDF-1 and Wnt signaling pathway in the myocardial fibrosis of hypertensive rats.

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    Shao, Shuai; Cai, Wenwei; Sheng, Jing; Yin, Lingni

    2015-01-01

    To investigate the effects of stromal cell-derived factor-1 (SDF-1) and Wnt signaling pathway on the bioactivities of myofibroblasts (MFs) and the expressions of SDF-1 and components of Wnt signaling pathway in the myocardium of spontaneously hypertensive rats (SHR). BMSCs were induced to differentiate into MFs in vitro, and SDF-1 and Wnt signaling pathway were independently or simultaneously blocked. Then, the migration of MFs and the secretion of Col I and α-SMA were determined in MFs. Heart function, progression of myocardial fibrosis and structure of the heart were evaluated. The expression of SDF-1 and components of Wnt signaling pathway in SHR was detected. TGF-β could induce the differentiation of BMSCs into B-MFs; Blocking SDF-1/CXCR4 axis and/or Wnt signaling pathway was able to inhibit the MFs migration and Col I secretion; Blocking Wnt signaling pathway inhibited the differentiation of BMSCs into MFs; Serum SDF-1 increased with the increase in blood pressure, and serum β-catenin elevated with the fluctuation of blood pressure; Protein and mRNA expressions of SDF-1 in the myocardium increased, and those of DKK-1 (an inhibitor of Wnt signaling pathway) and GSK-3 reduced in SHR. SDF-1 and Wnt signaling pathway are involved in the differentiation of BMSCs into MFs, as well as the migration and collagen secretion of MFs; Hypertension affects the expressions of SDF-1 and components of Wnt signaling pathway. In the myocardium of SHR, SDF-1 expression increases, but the expression of inhibitor of Wnt signaling pathway reduces.

  3. A review of the evidence for the canonical Wnt pathway in autism spectrum disorders

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    Kalkman Hans

    2012-10-01

    Full Text Available Abstract Microdeletion and microduplication copy number variations are found in patients with autism spectrum disorder and in a number of cases they include genes that are involved in the canonical Wnt signaling pathway (for example, FZD9, BCL9 or CDH8. Association studies investigating WNT2, DISC1, MET, DOCK4 or AHI1 also provide evidence that the canonical Wnt pathway might be affected in autism. Prenatal medication with sodium-valproate or antidepressant drugs increases autism risk. In animal studies, it has been found that these medications promote Wnt signaling, including among others an increase in Wnt2 gene expression. Notably, the available genetic information indicates that not only canonical Wnt pathway activation, but also inhibition seems to increase autism risk. The canonical Wnt pathway plays a role in dendrite growth and suboptimal activity negatively affects the dendritic arbor. In principle, this provides a logical explanation as to why both hypo- and hyperactivity may generate a similar set of behavioral and cognitive symptoms. However, without a validated biomarker to stratify for deviant canonical Wnt pathway activity, it is probably too dangerous to treat patients with compounds that modify pathway activity.

  4. Wnt-RhoA signaling pathways in fluoride-treated ameloblast-lineage cells.

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    Shusterman, Kate; Gibson, Carolyn W; Li, Yong; Healey, Melissa; Peng, Li

    2014-01-01

    This study examined the effect of sodium fluoride (NaF) on the Wnt and RhoA signaling pathways in murine ameloblast-lineage cells (ALCs) to better understand the developmental mechanisms of dental fluorosis. Wnt and Rho pathway activities were investigated when ALCs were treated with 1.5 mM NaF, dickkopf-related protein-1 (Dkk-1), secreted frizzled related-protein-2 (sFRP-2), β-catenin siRNA dominant negative RhoA (RhoA(DN)) plasmid and Y-27632. Wnt pathway activity was investigated via RT-PCR, Western blot and Topflash luciferase assay. The activity of the RhoA pathway was analyzed via Rho pull-down assay and immunoprecipitation. The differentiation of ALCs was analyzed by alkaline phosphatase assay. Western blot and Topflash luciferase assay results verified that both the Wnt and Rho pathways were upregulated by 1.5 mM NaF. Wnt was discovered to be located upstream from the Rho pathway, as confirmed by treatment with Wnt pathway cell receptor inhibitors Dkk-1 and sFRP-2, leading to a decrease in RhoA and ROCK activity. Inhibition of the Rho pathway with RhoA(DN) plasmid and Y-27632 caused upregulation of Wnt pathway activity which could be further increased by 1.5 mM NaF. The increased Wnt pathway activity was found to negatively regulate ALC differentiation. These data suggest that fluoride could induce the cross-talk between Wnt and RhoA signaling pathways, and these responses are predicted to contribute to the development of enamel fluorosis. © 2014 S. Karger AG, Basel.

  5. A dual role of the Wnt signaling pathway during aging in Caenorhabditis elegans

    NARCIS (Netherlands)

    Lezzerini, M.; Budovskaya, Y.

    2014-01-01

    Wnt signaling is a major and highly conserved developmental pathway that guides many important events during embryonic and larval development. In adulthood, misregulation of Wnt signaling has been implicated in tumorigenesis and various age-related diseases. These effects occur through highly

  6. The non-canonical BMP and Wnt/β-catenin signaling pathways orchestrate early tooth development.

    Science.gov (United States)

    Yuan, Guohua; Yang, Guobin; Zheng, Yuqian; Zhu, Xiaojing; Chen, Zhi; Zhang, Zunyi; Chen, YiPing

    2015-01-01

    BMP and Wnt signaling pathways play a crucial role in organogenesis, including tooth development. Despite extensive studies, the exact functions, as well as if and how these two pathways act coordinately in regulating early tooth development, remain elusive. In this study, we dissected regulatory functions of BMP and Wnt pathways in early tooth development using a transgenic noggin (Nog) overexpression model (K14Cre;pNog). It exhibits early arrested tooth development, accompanied by reduced cell proliferation and loss of odontogenic fate marker Pitx2 expression in the dental epithelium. We demonstrated that overexpression of Nog disrupted BMP non-canonical activity, which led to a dramatic reduction of cell proliferation rate but did not affect Pitx2 expression. We further identified a novel function of Nog by inhibiting Wnt/β-catenin signaling, causing loss of Pitx2 expression. Co-immunoprecipitation and TOPflash assays revealed direct binding of Nog to Wnts to functionally prevent Wnt/β-catenin signaling. In situ PLA and immunohistochemistry on Nog mutants confirmed in vivo interaction between endogenous Nog and Wnts and modulation of Wnt signaling by Nog in tooth germs. Genetic rescue experiments presented evidence that both BMP and Wnt signaling pathways contribute to cell proliferation regulation in the dental epithelium, with Wnt signaling also controlling the odontogenic fate. Reactivation of both BMP and Wnt signaling pathways, but not of only one of them, rescued tooth developmental defects in K14Cre;pNog mice, in which Wnt signaling can be substituted by transgenic activation of Pitx2. Our results reveal the orchestration of non-canonical BMP and Wnt/β-catenin signaling pathways in the regulation of early tooth development. © 2015. Published by The Company of Biologists Ltd.

  7. Understanding and Targeting the Wnt/β-Catenin Signaling Pathway in Chronic Leukemia

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    S. Thanendrarajan

    2011-01-01

    Full Text Available It has been revealed that the Wnt/β-catenin signaling pathway plays an important role in the development of solid tumors and hematological malignancies, particularly in B-cell neoplasia and leukemia. In the last decade there have been made experimental approaches targeting the Wnt pathway in chronic leukemia. In this paper we provide an overview about the current state of knowledge regarding the Wnt/β-catenin signaling pathway in chronic leukemia with special focus on therapeutic options and strategies.

  8. Wnt/β-catenin, an oncogenic pathway targeted by H. pylori in gastric carcinogenesis.

    Science.gov (United States)

    Song, Xiaowen; Xin, Na; Wang, Wei; Zhao, Chenghai

    2015-11-03

    A section of gastric cancers presents nuclear β-catenin accumulation correlated with H. pylori infection. H. pylori stimulate Wnt/β-catenin pathway by activating oncogenic c-Met and epidermal growth factor receptor (EGFR), or by inhibiting tumor suppressor Runx3 and Trefoil factor 1 (TFF1). H. pylori also trigger Wnt/β-catenin pathway by recruiting macrophages. Moreover, Wnt/β-catenin pathway is found involved in H. pylori-induced gastric cancer stem cell generation. Recently, by using gastroids, researchers have further revealed that H. pylori induce gastric epithelial cell proliferation through β-catenin. These findings indicate that Wnt/β-catenin is an oncogenic pathway activated by H. pylori. Therefore, this pathway is a potential therapy target for H. pylori-related gastric cancer.

  9. Remote activation of the Wnt/β-catenin signalling pathway using functionalised magnetic particles.

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    Michael Rotherham

    Full Text Available Wnt signalling pathways play crucial roles in developmental biology, stem cell fate and tissue patterning and have become an attractive therapeutic target in the fields of tissue engineering and regenerative medicine. Wnt signalling has also been shown to play a role in human Mesenchymal Stem Cell (hMSC fate, which have shown potential as a cell therapy in bone and cartilage tissue engineering. Previous work has shown that biocompatible magnetic nanoparticles (MNP can be used to stimulate specific mechanosensitive membrane receptors and ion channels in vitro and in vivo. Using this strategy, we determined the effects of mechano-stimulation of the Wnt Frizzled receptor on Wnt pathway activation in hMSC. Frizzled receptors were tagged using anti-Frizzled functionalised MNP (Fz-MNP. A commercially available oscillating magnetic bioreactor (MICA Biosystems was used to mechanically stimulate Frizzled receptors remotely. Our results demonstrate that Fz-MNP can activate Wnt/β-catenin signalling at key checkpoints in the signalling pathway. Immunocytochemistry indicated nuclear localisation of the Wnt intracellular messenger β-catenin after treatment with Fz-MNP. A Wnt signalling TCF/LEF responsive luciferase reporter transfected into hMSC was used to assess terminal signal activation at the nucleus. We observed an increase in reporter activity after treatment with Fz-MNP and this effect was enhanced after mechano-stimulation using the magnetic array. Western blot analysis was used to probe the mechanism of signalling activation and indicated that Fz-MNP signal through an LRP independent mechanism. Finally, the gene expression profiles of stress response genes were found to be similar when cells were treated with recombinant Wnt-3A or Fz-MNP. This study provides proof of principle that Wnt signalling and Frizzled receptors are mechanosensitive and can be remotely activated in vitro. Using magnetic nanoparticle technology it may be possible to modulate

  10. Wnt pathway reprogramming during human embryonal carcinoma differentiation and potential for therapeutic targeting

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    Bee Thomas

    2009-10-01

    Full Text Available Abstract Background Testicular germ cell tumors (TGCTs are classified as seminonas or non-seminomas of which a major subset is embryonal carcinoma (EC that can differentiate into diverse tissues. The pluripotent nature of human ECs resembles that of embryonic stem (ES cells. Many Wnt signalling species are regulated during differentiation of TGCT-derived EC cells. This study comprehensively investigated expression profiles of Wnt signalling components regulated during induced differentiation of EC cells and explored the role of key components in maintaining pluripotency. Methods Human embryonal carcinoma cells were stably infected with a lentiviral construct carrying a canonical Wnt responsive reporter to assess Wnt signalling activity following induced differentiation. Cells were differentiated with all-trans retinoic acid (RA or by targeted repression of pluripotency factor, POU5F1. A Wnt pathway real-time-PCR array was used to evaluate changes in gene expression as cells differentiated. Highlighted Wnt pathway genes were then specifically repressed using siRNA or stable shRNA and transfected EC cells were assessed for proliferation, differentiation status and levels of core pluripotency genes. Results Canonical Wnt signalling activity was low basally in undifferentiated EC cells, but substantially increased with induced differentiation. Wnt pathway gene expression levels were compared during induced differentiation and many components were altered including ligands (WNT2B, receptors (FZD5, FZD6, FZD10, secreted inhibitors (SFRP4, SFRP1, and other effectors of Wnt signalling (FRAT2, DAAM1, PITX2, Porcupine. Independent repression of FZD5, FZD7 and WNT5A using transient as well as stable methods of RNA interference (RNAi inhibited cell growth of pluripotent NT2/D1 human EC cells, but did not appreciably induce differentiation or repress key pluripotency genes. Silencing of FZD7 gave the greatest growth suppression in all human EC cell lines

  11. Toward a quantitative understanding of the Wnt/ β -catenin pathway through simulation and experiment

    KAUST Repository

    Lloyd-Lewis, Bethan

    2013-03-29

    Wnt signaling regulates cell survival, proliferation, and differentiation throughout development and is aberrantly regulated in cancer. The pathway is activated when Wnt ligands bind to specific receptors on the cell surface, resulting in the stabilization and nuclear accumulation of the transcriptional co-activator β-catenin. Mathematical and computational models have been used to study the spatial and temporal regulation of the Wnt/β-catenin pathway and to investigate the functional impact of mutations in key components. Such models range in complexity, from time-dependent, ordinary differential equations that describe the biochemical interactions between key pathway components within a single cell, to complex, multiscale models that incorporate the role of the Wnt/β-catenin pathway target genes in tissue homeostasis and carcinogenesis. This review aims to summarize recent progress in mathematical modeling of the Wnt pathway and to highlight new biological results that could form the basis for future theoretical investigations designed to increase the utility of theoretical models of Wnt signaling in the biomedical arena. © 2013 Wiley Periodicals, Inc.

  12. Macrophages Mediate a Switch between Canonical and Non-Canonical Wnt Pathways in Canine Mammary Tumors

    Science.gov (United States)

    Król, Magdalena; Mucha, Joanna; Majchrzak, Kinga; Homa, Agata; Bulkowska, Małgorzata; Majewska, Alicja; Gajewska, Małgorzata; Pietrzak, Marta; Perszko, Mikołaj; Romanowska, Karolina; Pawłowski, Karol; Manuali, Elisabetta; Hellmen, Eva; Motyl, Tomasz

    2014-01-01

    Objective According to the current hypothesis, tumor-associated macrophages (TAMs) are “corrupted” by cancer cells and subsequently facilitate, rather than inhibit, tumor metastasis. Because the molecular mechanisms of cancer cell–TAM interactions are complicated and controversial we aimed to better define this phenomenon. Methods and Results Using microRNA microarrays, Real-time qPCR and Western blot we showed that co-culture of canine mammary tumor cells with TAMs or treatment with macrophage-conditioned medium inhibited the canonical Wnt pathway and activated the non-canonical Wnt pathway in tumor cells. We also showed that co-culture of TAMs with tumor cells increased expression of canonical Wnt inhibitors in TAMs. Subsequently, we demonstrated macrophage-induced invasive growth patterns and epithelial–mesenchymal transition of tumor cells. Validation of these results in canine mammary carcinoma tissues (n = 50) and xenograft tumors indicated the activation of non-canonical and canonical Wnt pathways in metastatic tumors and non-metastatic malignancies, respectively. Activation of non-canonical Wnt pathway correlated with number of TAMs. Conclusions We demonstrated that TAMs mediate a “switch” between canonical and non-canonical Wnt signaling pathways in canine mammary tumors, leading to increased tumor invasion and metastasis. Interestingly, similar changes in neoplastic cells were observed in the presence of macrophage-conditioned medium or live macrophages. These observations indicate that rather than being “corrupted” by cancer cells, TAMs constitutively secrete canonical Wnt inhibitors that decrease tumor proliferation and development, but as a side effect, they induce the non-canonical Wnt pathway, which leads to tumor metastasis. These data challenge the conventional understanding of TAM–cancer cell interactions. PMID:24404146

  13. Contribution of genetic and epigenetic mechanisms to Wnt pathway activity in prevalent skeletal disorders.

    Science.gov (United States)

    García-Ibarbia, Carmen; Delgado-Calle, Jesús; Casafont, Iñigo; Velasco, Javier; Arozamena, Jana; Pérez-Núñez, María I; Alonso, María A; Berciano, María T; Ortiz, Fernando; Pérez-Castrillón, José L; Fernández, Agustín F; Fraga, Mario F; Zarrabeitia, María T; Riancho, José A

    2013-12-15

    We reported previously that the expression of Wnt-related genes is lower in osteoporotic hip fractures than in osteoarthritis. We aimed to confirm those results by analyzing β-catenin levels and explored potential genetic and epigenetic mechanisms involved. β-Catenin gene expression and nuclear levels were analyzed by real time PCR and confocal immunofluorescence. Increased nuclear β-catenin was found in osteoblasts isolated from patients with osteoarthritis (99 ± 4 units vs. 76 ± 12, p=0.01, n=10), without differences in gene transcription, which is consistent with a post-translational down-regulation of β-catenin and decreased Wnt pathway activity. Twenty four single nucleotide polymorphisms (SNPs) of genes showing differential expression between fractures and osteoarthritis (WNT4, WNT10A, WNT16 and SFRP1) were analyzed in DNA isolated from blood of 853 patients. The genotypic frequencies were similar in both groups of patients, with no significant differences. Methylation of Wnt pathway genes was analyzed in bone tissue samples (15 with fractures and 15 with osteoarthritis) by interrogating a CpG-based methylation array. Six genes showed significant methylation differences between both groups of patients: FZD10, TBL1X, CSNK1E, WNT8A, CSNK1A1L and SFRP4. The DNA demethylating agent 5-deoxycytidine up-regulated 8 genes, including FZD10, in an osteoblast-like cell line, whereas it down-regulated other 16 genes. In conclusion, Wnt activity is reduced in patients with hip fractures, in comparison with those with osteoarthritis. It does not appear to be related to differences in the allele frequencies of the Wnt genes studied. On the other hand, methylation differences between both groups could contribute to explain the differences in Wnt activity. © 2013.

  14. Interrelationship of canonical and non-canonical Wnt signalling pathways in chronic metabolic diseases.

    Science.gov (United States)

    Ackers, Ian; Malgor, Ramiro

    2018-01-01

    Chronic diseases account for approximately 45% of all deaths in developed countries and are particularly prevalent in countries with the most sophisticated and robust public health systems. Chronic metabolic diseases, specifically lifestyle-related diseases pertaining to diet and exercise, continue to be difficult to treat clinically. The most prevalent of these chronic metabolic diseases include obesity, diabetes, non-alcoholic fatty liver disease, chronic kidney disease and cardiovascular disease and will be the focus of this review. Wnt proteins are highly conserved glycoproteins best known for their role in development and homeostasis of tissues. Given the importance of Wnt signalling in homeostasis, aberrant Wnt signalling likely regulates metabolic processes and may contribute to the development of chronic metabolic diseases. Expression of Wnt proteins and dysfunctional Wnt signalling has been reported in multiple chronic diseases. It is interesting to speculate about an interrelationship between the Wnt signalling pathways as a potential pathological mechanism in chronic metabolic diseases. The aim of this review is to summarize reported findings on the contrasting roles of Wnt signalling in lifestyle-related chronic metabolic diseases; specifically, the contribution of Wnt signalling to lipid accumulation, fibrosis and chronic low-grade inflammation.

  15. Wnt5a-Ror-Dishevelled signaling constitutes a core developmental pathway that controls tissue morphogenesis.

    Science.gov (United States)

    Ho, Hsin-Yi Henry; Susman, Michael W; Bikoff, Jay B; Ryu, Yun Kyoung; Jonas, Andrea M; Hu, Linda; Kuruvilla, Rejji; Greenberg, Michael Eldon

    2012-03-13

    Wnts make up a large family of extracellular signaling molecules that play crucial roles in development and disease. A subset of noncanonical Wnts signal independently of the transcription factor β-catenin by a mechanism that regulates key morphogenetic movements during embryogenesis. The best characterized noncanonical Wnt, Wnt5a, has been suggested to signal via a variety of different receptors, including the Ror family of receptor tyrosine kinases, the Ryk receptor tyrosine kinase, and the Frizzled seven-transmembrane receptors. Whether one or several of these receptors mediates the effects of Wnt5a in vivo is not known. Through loss-of-function experiments in mice, we provide conclusive evidence that Ror receptors mediate Wnt5a-dependent processes in vivo and identify Dishevelled phosphorylation as a physiological target of Wnt5a-Ror signaling. The absence of Ror signaling leads to defects that mirror phenotypes observed in Wnt5a null mutant mice, including decreased branching of sympathetic neuron axons and major defects in aspects of embryonic development that are dependent upon morphogenetic movements, such as severe truncation of the caudal axis, the limbs, and facial structures. These findings suggest that Wnt5a-Ror-Dishevelled signaling constitutes a core noncanonical Wnt pathway that is conserved through evolution and is crucial during embryonic development.

  16. Wnt/β-catenin signalling pathway mediated aberrant hippocampal neurogenesis in kainic acid-induced epilepsy.

    Science.gov (United States)

    Qu, Zhengyi; Su, Fang; Qi, Xueting; Sun, Jianbo; Wang, Hongcai; Qiao, Zhenkui; Zhao, Hong; Zhu, Yulan

    2017-10-01

    Temporal lobe epilepsy is a chronic disorder of nerve system, mainly characterized by hippocampal sclerosis with massive neuronal loss and severe gliosis. Aberrant neurogenesis has been shown in the epileptogenesis process of temporal lobe epilepsy. However, the molecular mechanisms underlying aberrant neurogenesis remain unclear. The roles of Wnt signalling cascade have been well established in neurogenesis during multiple aspects. Here, we used kainic acid-induced rat epilepsy model to investigate whether Wnt/β-catenin signalling pathway is involved in the aberrant neurogenesis in temporal lobe epilepsy. Immunostaining and western blotting results showed that the expression levels of β-catenin, Wnt3a, and cyclin D1, the key regulators in Wnt signalling pathway, were up-regulated during acute epilepsy induced by the injection of kainic acids, indicating that Wnt signalling pathway was activated in kainic acid-induced temporal lobe epilepsy. Moreover, BrdU labelling results showed that blockade of the Wnt signalling by knocking down β-catenin attenuated aberrant neurogenesis induced by kainic acids injection. Altogether, Wnt/β-catenin signalling pathway mediated hippocampal neurogenesis during epilepsy, which might provide new strategies for clinical treatment of temporal lobe epilepsy. Temporal lobe epilepsy is a chronic disorder of nerve system, mainly characterized by hippocampal sclerosis. Aberrant neurogenesis has been shown to involve in the epileptogenesis process of temporal lobe epilepsy. In the present study, we discovered that Wnt3a/β-catenin signalling pathway serves as a link between aberrant neurogenesis and underlying remodelling in the hippocampus, leading to temporal lobe epilepsy, which might provide new strategies for clinical treatment of temporal lobe epilepsy. Copyright © 2017 John Wiley & Sons, Ltd.

  17. Bioinformatic Evaluation of Transcriptional Regulation of WNT Pathway Genes with reference to Diabetic Nephropathy

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    Gareth J. McKay

    2016-01-01

    Full Text Available Objective. WNT/β-catenin pathway members have been implicated in interstitial fibrosis and glomerular sclerosis disease processes characteristic of diabetic nephropathy (DN, processes partly controlled by transcription factors (TFs that bind to gene promoter regions attenuating regulation. We sought to identify predicted cis-acting transcription factor binding sites (TFBSs overrepresented within WNT pathway members. Methods. We assessed 62 TFBS motif frequencies from the JASPAR databases in 65 WNT pathway genes. P values were estimated on the hypergeometric distribution for each TF. Gene expression profiles of enriched motifs were examined in DN-related datasets to assess clinical significance. Results. Transcription factor AP-2 alpha (TFAP2A, myeloid zinc finger 1 (MZF1, and specificity protein 1 (SP1 were significantly enriched within WNT pathway genes (P values < 6.83 × 10−29, 1.34 × 10−11, and 3.01 × 10−6, resp.. MZF1 expression was significantly increased in DN in a whole kidney dataset (fold change = 1.16; 16% increase; P=0.03. TFAP2A expression was decreased in an independent dataset (fold change = −1.02; P=0.03. No differential expression of SP1 was detected. Conclusions. Three TFBS profiles are significantly enriched within WNT pathway genes highlighting the potential of in silico analyses for identification of pathway regulators. Modification of TF binding may possibly limit DN progression, offering potential therapeutic benefit.

  18. Notch, Wnt, and Hedgehog Pathways in Rhabdomyosarcoma: From Single Pathways to an Integrated Network

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    Josep Roma

    2012-01-01

    Full Text Available Rhabdomyosarcoma (RMS is the most common type of soft tissue sarcoma in children. Regarding histopathological criteria, RMS can be divided into 2 main subtypes: embryonal and alveolar. These subtypes differ considerably in their clinical phenotype and molecular features. Abnormal regulation or mutation of signalling pathways that regulate normal embryonic development such as Notch, Hedgehog, and Wnt is a recurrent feature in tumorigenesis. Herein, the general features of each of the three pathways, their implication in cancer and particularly in RMS are reviewed. Finally, the cross-talking among these three pathways and the possibility of better understanding of the horizontal communication among them, leading to the development of more potent therapeutic approaches, are discussed.

  19. Pathways to urban sustainability

    NARCIS (Netherlands)

    Nijkamp, Peter; Finco, Adele

    2001-01-01

    The concept of sustainable development has become very much "en vogue" in the past decade.We have also observed a shift in the interpretation of this concept from a global perspectiveto a meso perspective, i.e. a local, regional or sectoral level.This paper aims to highlight the urban dimension of

  20. Inhibition of Wnt/β-catenin pathway by niclosamide: a therapeutic target for ovarian cancer.

    Science.gov (United States)

    Arend, Rebecca C; Londoño-Joshi, Angelina I; Samant, Rajeev S; Li, Yonghe; Conner, Michael; Hidalgo, Bertha; Alvarez, Ronald D; Landen, Charles N; Straughn, J Michael; Buchsbaum, Donald J

    2014-07-01

    Objective. The Wnt/β-catenin pathway is known to regulate cellular proliferation and plays a role in chemoresistance. Niclosamide, an FDA approved salicyclamide derivative used for the treatment of tapeworm infections, targets the Wnt/β-catenin pathway. Therefore, the objective of this study was to investigate niclosamide as a potential therapeutic agent for ovarian cancer. Methods. Tumor cells isolated from 34 patients' ascites with primary ovarian cancer were treated with niclosamide (0.1 to 5 μM) ± carboplatin (5 to 150 μM). Cell viability was assessed using the ATP-lite assay. LRP6, Axin 2, Cyclin D1, survivin and cytosolic free β-catenin levels were determined using Western blot analysis. Tumorspheres were treated, and Wnt transcriptional activity was measured by the TOPflash reporter assay. ALDH and CD133 were analyzed by Flow cytometry and IHC. ALDH1A1 and LRP6 were analyzed by IHC in solid tumor and in ascites before and after treatment with niclosamide. Results. Combination treatment produced increased cytotoxicity compared to single agent treatment in 32/34 patient samples. Western blot analysis showed a decrease in Wnt/β-catenin pathway proteins and the expression of target genes. A significant reduction of Wnt/β-catenin signaling was confirmed by TOPflash assay. There was increased staining of ALDH1A1 and LRP6 in ascites compared to solid tumor which decreased after treatment. Conclusion. This study demonstrates that niclosamide is a potent Wnt/β-catenin inhibitor. Targeting the Wnt/β-catenin pathway led to decreased cellular proliferation and increased cell death. These findings warrant further research of this drug and other niclosamide analogs as a treatment option for ovarian cancer. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. LRP5 and plasma cholesterol levels modulate the canonical Wnt pathway in peripheral blood leukocytes.

    Science.gov (United States)

    Borrell-Pages, Maria; Carolina Romero, July; Badimon, Lina

    2015-08-01

    Inflammation is triggered after invasion or injury to restore homeostasis. Although the activation of Wnt/β-catenin signaling is one of the first molecular responses to cellular damage, its role in inflammation is still unclear. It was our hypothesis that the low-density lipoprotein (LDL) receptor-related protein 5 (LRP5) and the canonical Wnt signaling pathway are modulators of inflammatory mechanisms. Wild-type (WT) and LRP5(-/-) mice were fed a hypercholesterolemic (HC) diet to trigger dislipidemia and chronic inflammation. Diets were supplemented with plant sterol esters (PSEs) to induce LDL cholesterol lowering and the reduction of inflammation. HC WT mice showed increased serum cholesterol levels that correlated with increased Lrp5 and Wnt/β-catenin gene expression while in the HC LRP5(-/-) mice Wnt/β-catenin pathway was shut down. Functionally, HC induced pro-inflammatory gene expression in LRP5(-/-) mice, suggesting an inhibitory role of the Wnt pathway in inflammation. Dietary PSE administration downregulated serum cholesterol levels in WT and LRP5(-/-) mice. Furthermore, in WT mice PSE increased anti-inflammatory genes expression and inhibited Wnt/β-catenin activation. Hepatic gene expression of Vldlr, Lrp2 and Lrp6 was increased after HC feeding in WT mice but not in LRP5(-/-) mice, suggesting a role for these receptors in the clearance of plasmatic lipoproteins. Finally, an antiatherogenic role for LRP5 was demonstrated as HC LRP5(-/-) mice developed larger aortic atherosclerotic lesions than WT mice. Our results show an anti-inflammatory, pro-survival role for LRP5 and the Wnt signaling pathway in peripheral blood leukocytes.

  2. Wnt/β-catenin pathway regulates ABCB1 transcription in chronic myeloid leukemia

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    Corrêa Stephany

    2012-07-01

    Full Text Available Abstract Background The advanced phases of chronic myeloid leukemia (CML are known to be more resistant to therapy. This resistance has been associated with the overexpression of ABCB1, which gives rise to the multidrug resistance (MDR phenomenon. MDR is characterized by resistance to nonrelated drugs, and P-glycoprotein (encoded by ABCB1 has been implicated as the major cause of its emergence. Wnt signaling has been demonstrated to be important in several aspects of CML. Recently, Wnt signaling was linked to ABCB1 regulation through its canonical pathway, which is mediated by β-catenin, in other types of cancer. In this study, we investigated the involvement of the Wnt/β-catenin pathway in the regulation of ABCB1 transcription in CML, as the basal promoter of ABCB1 has several β-catenin binding sites. β-catenin is the mediator of canonical Wnt signaling, which is important for CML progression. Methods In this work we used the K562 cell line and its derived MDR-resistant cell line Lucena (K562/VCR as CML study models. Real time PCR (RT-qPCR, electrophoretic mobility shift assay (EMSA, chromatin immunoprecipitation (ChIP, flow cytometry (FACS, western blot, immunofluorescence, RNA knockdown (siRNA and Luciferase reporter approaches were used. Results β-catenin was present in the protein complex on the basal promoter of ABCB1 in both cell lines in vitro, but its binding was more pronounced in the resistant cell line in vivo. Lucena cells also exhibited higher β-catenin levels compared to its parental cell line. Wnt1 and β-catenin depletion and overexpression of nuclear β-catenin, together with TCF binding sites activation demonstrated that ABCB1 is positively regulated by the canonical pathway of Wnt signaling. Conclusions These results suggest, for the first time, that the Wnt/β-catenin pathway regulates ABCB1 in CML.

  3. Activation of intracellular calcium by multiple Wnt ligands and translocation of β-catenin into the nucleus: a convergent model of Wnt/Ca2+ and Wnt/β-catenin pathways.

    Science.gov (United States)

    Thrasivoulou, Christopher; Millar, Michael; Ahmed, Aamir

    2013-12-13

    Ca(2+) and β-catenin, a 92-kDa negatively charged transcription factor, transduce Wnt signaling via the non-canonical, Wnt/Ca(2+) and canonical, Wnt/β-catenin pathways independently. The nuclear envelope is a barrier to large protein entry, and this process is regulated by intracellular calcium [Ca(2+)]i and trans-nuclear potential. How β-catenin traverses the nuclear envelope is not well known. We hypothesized that Wnt/Ca(2+) and Wnt/β-catenin pathways act in a coordinated manner and that [Ca(2+)]i release facilitates β-catenin entry into the nucleus in mammalian cells. In a live assay using calcium dyes in PC3 prostate cancer cells, six Wnt peptides (3A, 4, 5A, 7A, 9B, and 10B) mobilized [Ca(2+)]i but Wnt11 did not. Based upon dwell time (range = 15-30 s) of the calcium waveform, these Wnts could be classified into three classes: short, 3A and 5A; long, 7A and 10B; and very long, 4 and 9B. Wnt-activated [Ca(2+)]i release was followed by an increase in intranuclear calcium and the depolarization of both the cell and nuclear membranes, determined by using FM4-64. In cells treated with Wnts 5A, 9B, and 10B, paradigm substrates for each Wnt class, increased [Ca(2+)]i was followed by β-catenin translocation into the nucleus in PC3, MCF7, and 253J, prostate, breast, and bladder cancer cell lines; both the increase in Wnt 5A, 9B, and 10B induced [Ca(2+)]i release and β-catenin translocation are suppressed by thapsigargin in PC3 cell line. We propose a convergent model of Wnt signaling network where Ca(2+) and β-catenin pathways may act in a coordinated, interdependent, rather than independent, manner.

  4. A Wnt5a signaling pathway in the pathogenesis of HIV-1 gp120-induced pain.

    Science.gov (United States)

    Yuan, Su-Bo; Ji, Guangchen; Li, Bei; Andersson, Tommy; Neugebauer, Volker; Tang, Shao-Jun

    2015-07-01

    Pathological pain is one of the most common neurological complications in patients with HIV-1/AIDS. However, the pathogenic process is unclear. Our recent studies show that Wnt5a is upregulated in the spinal cord dorsal horn (SDH) of the patients with HIV who develop pain and that HIV-1 gp120, a potential causal factor of the HIV-associated pain, rapidly upregulates Wnt5a in the mouse SDH. Using a mouse model, we show here that a specific Wnt5a antagonist, Box-5, attenuated gp120-induced mechanical allodynia. Conversely, a Wnt5a agonist, Foxy5, facilitated the allodynia. To elucidate the molecular mechanism by which Wnt5a regulates gp120-induced allodynia, we tested the role of the JNK/TNF-α pathway. We observed that the JNK-specific inhibitor SP600125 blocked either gp120- or Foxy5-induced allodynia. Similarly, the TNF-α-specific antagonist Enbrel also reversed either gp120- or Foxy5-induced allodynia. These data suggest that JNK and TNF-α mediate the biological effects of Wnt5a in regulating gp120-induced allodynia. To investigate the cellular mechanism, we performed extracellular single-unit recording from SDH neurons in anesthetized mice. Both Box-5 and SP600125 negated gp120-induced potentiation of SDH neuron spiking evoked by mechanical stimulation of the hind paw. Furthermore, while Foxy5 potentiated spike frequency of SDH neurons, either SP600125 or Enbrel blocked the potentiation. The data indicate that Wnt5a potentiates the activity of SDH neurons through the JNK-TNF-α pathway. Collectively, our findings suggest that Wnt5a regulates the pathogenesis of gp120-induced pain, likely by sensitizing pain-processing SDH neurons through JNK/TNF-α signaling.

  5. ERβ induces the differentiation of cultured osteoblasts by both Wnt/β-catenin signaling pathway and estrogen signaling pathways

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Xinhua [Department of Spine Surgery, Xiangya Hospital of Central South University, Changsha (China); Wang, Xiaoyuan [Department of Nephrology, Xi An Honghui Hospital, Xi an (China); Hu, Xiongke; Chen, Yong; Zeng, Kefeng [Department of Spine Surgery, Xiangya Hospital of Central South University, Changsha (China); Zhang, Hongqi, E-mail: zhq9699@126.com [Department of Spine Surgery, Xiangya Hospital of Central South University, Changsha (China)

    2015-07-01

    Although 17β-estradial (E2) is known to stimulate bone formation, the underlying mechanisms are not fully understood. Recent studies have implicated the Wnt/β-catenin pathway as a major signaling cascade in bone biology. The interactions between Wnt/β-catenin signaling pathway and estrogen signaling pathways have been reported in many tissues. In this study, E2 significantly increased the expression of β-catenin by inducing phosphorylations of GSK3β at serine 9. ERβ siRNAs were transfected into MC3T3-E1 cells and revealed that ERβ involved E2-induced osteoblasts proliferation and differentiation via Wnt/β-catenin signaling. The osteoblast differentiation genes (BGP, ALP and OPN) and proliferation related gene (cyclin D1) expression were significantly induced by E2-mediated ERβ. Furthermore immunofluorescence and immunoprecipitation analysis demonstrated that E2 induced the accumulation of β-catenin protein in the nucleus which leads to interaction with T-cell-specific transcription factor/lymphoid enhancer binding factor (TCF/LEF) transcription factors. Taken together, these findings suggest that E2 promotes osteoblastic proliferation and differentiation by inducing proliferation-related and differentiation-related gene expression via ERβ/GSK-3β-dependent Wnt/β-catenin signaling pathway. Our findings provide novel insights into the mechanisms of action of E2 in osteoblastogenesis. - Highlights: • 17β-estradial (E2) promotes GSK3-β phosphorylation. • E2 activates the Wnt/β-catenin signaling pathway. • The Wnt/β-catenin signaling pathway interacts with estrogen signaling pathways. • E2-mediated ER induced osteoblast differentiation and proliferation related genes expression.

  6. Ethacrynic acid exhibits selective toxicity to chronic lymphocytic leukemia cells by inhibition of the Wnt/beta-catenin pathway.

    Directory of Open Access Journals (Sweden)

    Desheng Lu

    Full Text Available BACKGROUND: Aberrant activation of Wnt/beta-catenin signaling promotes the development of several cancers. It has been demonstrated that the Wnt signaling pathway is activated in chronic lymphocytic leukemia (CLL cells, and that uncontrolled Wnt/beta-catenin signaling may contribute to the defect in apoptosis that characterizes this malignancy. Thus, the Wnt signaling pathway is an attractive candidate for developing targeted therapies for CLL. METHODOLOGY/PRINCIPAL FINDINGS: The diuretic agent ethacrynic acid (EA was identified as a Wnt inhibitor using a cell-based Wnt reporter assay. In vitro assays further confirmed the inhibitory effect of EA on Wnt/beta-catenin signaling. Cell viability assays showed that EA selectively induced cell death in primary CLL cells. Exposure of CLL cells to EA decreased the expression of Wnt/beta-catenin target genes, including LEF-1, cyclin D1 and fibronectin. Immune co-precipitation experiments demonstrated that EA could directly bind to LEF-1 protein and destabilize the LEF-1/beta-catenin complex. N-acetyl-L-cysteine (NAC, which can react with the alpha, beta-unsaturated ketone in EA, but not other anti-oxidants, prevented the drug's inhibition of Wnt/beta-catenin activation and its ability to induce apoptosis in CLL cells. CONCLUSIONS/SIGNIFICANCE: Our studies indicate that EA selectively suppresses CLL survival due to inhibition of Wnt/beta-catenin signaling. Antagonizing Wnt signaling in CLL with EA or related drugs may represent an effective treatment of this disease.

  7. How the Wnt signaling pathway protects from neurodegeneration: The Mitochondrial Scenario

    Directory of Open Access Journals (Sweden)

    Macarena S. Arrázola

    2015-05-01

    Full Text Available Alzheimer´s disease (AD is the most common neurodegenerative disorder and is characterized by progressive memory loss and cognitive decline. One of the hallmarks of AD is the overproduction of amyloid-beta aggregates that range from the toxic soluble oligomer (Aβo form to extracellular accumulations in the brain. Growing evidence indicates that mitochondrial dysfunction is a common feature of neurodegenerative diseases and is observed at an early stage in the pathogenesis of AD. Reports indicate that mitochondrial structure and function are affected by Aβo and can trigger neuronal cell death. Mitochondria are highly dynamic organelles, and the balance between their fusion and fission processes is essential for neuronal function. Interestingly, in AD, the process known as mitochondrial dynamics is also impaired by Aβo. On the other hand, the activation of the Wnt signaling pathway has an essential role in synaptic maintenance and neuronal functions, and its deregulation has also been implicated in AD. We have demonstrated that canonical Wnt signaling, through the Wnt3a ligand, prevents the permeabilization of mitochondrial membranes through the inhibition of the mitochondrial permeability transition pore (mPTP, induced by Aβo. In addition, we showed that non-canonical Wnt signaling, through the Wnt5a ligand, protects mitochondria from fission-fusion alterations in AD. These results suggest new approaches by which different Wnt signaling pathways protect neurons in AD, and support the idea that mitochondria have become potential therapeutic targets for the treatment of neurodegenerative disorders. Here we discuss the neuroprotective role of the canonical and non-canonical Wnt signaling pathways in AD and their differential modulation of mitochondrial processes, associated with mitochondrial dysfunction and neurodegeneration.

  8. Developmental Lead Exposure Alters Synaptogenesis through Inhibiting Canonical Wnt Pathway In Vivo and In Vitro

    Science.gov (United States)

    Hu, Fan; Xu, Li; Liu, Zhi-Hua; Ge, Meng-Meng; Ruan, Di-Yun; Wang, Hui-Li

    2014-01-01

    Lead (Pb) exposure has been implicated in the impairment of synaptic plasticity in the developing hippocampus, but the mechanism remains unclear. Here, we investigated whether developmental lead exposure affects the dendritic spine formation through Wnt signaling pathway in vivo and in vitro. Sprague–Dawley rats were exposed to lead throughout the lactation period and Golgi-Cox staining method was used to examine the spine density of pyramidal neurons in the hippocampal CA1 area of rats. We found that lead exposure significantly decreased the spine density in both 14 and 21 days-old pups, accompanied by a significant age-dependent decline of the Wnt7a expression and stability of its downstream protein (β-catenin). Furthermore, in cultured hippocampal neurons, lead (0.1 and 1 µM lead acetate) significantly decreased the spine density in a dose-dependent manner. Exogenous Wnt7a application attenuated the decrease of spine density and increased the stability of the downstream molecules in Wnt signaling pathway. Together, our results suggest that lead has a negative impact on spine outgrowth in the developing hippocampus through altering the canonical Wnt pathway. PMID:24999626

  9. A Wnt-Frz/Ror-Dsh pathway regulates neurite outgrowth in Caenorhabditis elegans.

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    Song Song

    2010-08-01

    Full Text Available One of the challenges to understand the organization of the nervous system has been to determine how axon guidance molecules govern axon outgrowth. Through an unbiased genetic screen, we identified a conserved Wnt pathway which is crucial for anterior-posterior (A/P outgrowth of neurites from RME head motor neurons in Caenorhabditis elegans. The pathway is composed of the Wnt ligand CWN-2, the Frizzled receptors CFZ-2 and MIG-1, the co-receptor CAM-1/Ror, and the downstream component Dishevelled/DSH-1. Among these, CWN-2 acts as a local attractive cue for neurite outgrowth, and its activity can be partially substituted with other Wnts, suggesting that spatial distribution plays a role in the functional specificity of Wnts. As a co-receptor, CAM-1 functions cell-autonomously in neurons and, together with CFZ-2 and MIG-1, transmits the Wnt signal to downstream effectors. Yeast two-hybrid screening identified DSH-1 as a binding partner for CAM-1, indicating that CAM-1 could facilitate CWN-2/Wnt signaling by its physical association with DSH-1. Our study reveals an important role of a Wnt-Frz/Ror-Dsh pathway in regulating neurite A/P outgrowth.

  10. The role of the Wnt signaling pathway in cancer stem cells: prospects for drug development

    Directory of Open Access Journals (Sweden)

    Kim YM

    2014-07-01

    Full Text Available Yong-Mi Kim,1 Michael Kahn2,3 1Children's Hospital Los Angeles, Division of Hematology and Oncology, Department of Pediatrics and Pathology, 2Department of Biochemistry and Molecular Biology, Keck School of Medicine of University of Southern California, 3Norris Comprehensive Cancer Research Center, University of Southern California, Los Angeles, CA, USA Abstract: Cancer stem cells (CSCs, also known as tumor initiating cells are now considered to be the root cause of most if not all cancers, evading treatment and giving rise to disease relapse. They have become a central focus in new drug development. Prospective identification, understanding the key pathways that maintain CSCs, and being able to target CSCs, particularly if the normal stem cell population could be spared, could offer an incredible therapeutic advantage. The Wnt signaling cascade is critically important in stem cell biology, both in homeostatic maintenance of tissues and organs through their respective somatic stem cells and in the CSC/tumor initiating cell population. Aberrant Wnt signaling is associated with a wide array of tumor types. Therefore, the ability to safely target the Wnt signaling pathway offers enormous promise to target CSCs. However, just like the sword of Damocles, significant risks and concerns regarding targeting such a critical pathway in normal stem cell maintenance and tissue homeostasis remain ever present. With this in mind, we review recent efforts in modulating the Wnt signaling cascade and critically analyze therapeutic approaches at various stages of development. Keywords: beta-catenin, CBP, p300, wnt inhibition

  11. Erythropoietin inhibits osteoblast function in myelodysplastic syndromes via the canonical Wnt pathway.

    Science.gov (United States)

    Balaian, Ekaterina; Wobus, Manja; Weidner, Heike; Baschant, Ulrike; Stiehler, Maik; Ehninger, Gerhard; Bornhäuser, Martin; Hofbauer, Lorenz C; Rauner, Martina; Platzbecker, Uwe

    2018-01-01

    The effects of erythropoietin on osteoblasts and bone formation are controversial. Since patients with myelodysplastic syndromes often display excessively high erythropoietin levels, we aimed to analyze the effect of erythropoietin on osteoblast function in myelodysplastic syndromes and define the role of Wnt signaling in this process. Expression of osteoblast-specific genes and subsequent osteoblast mineralization was increased in mesenchymal stromal cells from healthy young donors by in vitro erythropoietin treatment. However, erythropoietin failed to increase osteoblast mineralization in old healthy donors and in patients with myelodysplasia, whereas the basal differentiation potential of the latter was already significantly reduced compared to that of age-matched controls ( P <0.01). This was accompanied by a significantly reduced expression of genes of the canonical Wnt pathway. Treatment of these cells with erythropoietin further inhibited the canonical Wnt pathway. Exposure of murine cells (C2C12) to erythropoietin also produced a dose-dependent inhibition of TCF/LEF promoter activity (maximum at 500 IU/mL, -2.8-fold; P <0.01). The decreased differentiation capacity of erythropoietin-pretreated mesenchymal stromal cells from patients with myelodysplasia could be restored by activating the Wnt pathway using lithium chloride or parathyroid hormone. Its hematopoiesis-supporting capacity was reduced, while reactivation of the canonical Wnt pathway in mesenchymal stromal cells could reverse this effect. Thus, these data demonstrate that erythropoietin modulates components of the osteo-hematopoietic niche in a context-dependent manner being anabolic in young, but catabolic in mature bone cells. Targeting the Wnt pathway in patients with myelodysplastic syndromes may be an appealing strategy to promote the functional capacity of the osteo-hematopoietic niche. Copyright© 2018 Ferrata Storti Foundation.

  12. MENA is a transcriptional target of the Wnt/beta-catenin pathway.

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    Ayaz Najafov

    Full Text Available Wnt/β-catenin signalling pathway plays important roles in embryonic development and carcinogenesis. Overactivation of the pathway is one of the most common driving forces in major cancers such as colorectal and breast cancers. The downstream effectors of the pathway and its regulation of carcinogenesis and metastasis are still not very well understood. In this study, which was based on two genome-wide transcriptomics screens, we identify MENA (ENAH, Mammalian enabled homologue as a novel transcriptional target of the Wnt/β-catenin signalling pathway. We show that the expression of MENA is upregulated upon overexpression of degradation-resistant β-catenin. Promoters of all mammalian MENA homologues contain putative binding sites for Tcf4 transcription factor--the primary effector of the Wnt/β-catenin pathway and we demonstrate functionality of these Tcf4-binding sites using luciferase reporter assays and overexpression of β-catenin, Tcf4 and dominant-negative Tcf4. In addition, lithium chloride-mediated inhibition of GSK3β also resulted in increase in MENA mRNA levels. Chromatin immunoprecipitation showed direct interaction between β-catenin and MENA promoter in Huh7 and HEK293 cells and also in mouse brain and liver tissues. Moreover, overexpression of Wnt1 and Wnt3a ligands increased MENA mRNA levels. Additionally, knock-down of MENA ortholog in D. melanogaster eyeful and sensitized eye cancer fly models resulted in increased tumor and metastasis formations. In summary, our study identifies MENA as novel nexus for the Wnt/β-catenin and the Notch signalling cascades.

  13. Resveratrol augments the canonical Wnt signaling pathway in promoting osteoblastic differentiation of multipotent mesenchymal cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Haibin; Shang, Linshan; Li, Xi; Zhang, Xiyu; Gao, Guimin; Guo, Chenhong; Chen, Bingxi; Liu, Qiji [Key Laboratory of Experimental Teratology, MOE, Institute of Molecular Medicine and Genetics, Shandong University, 44 Wen Hua Xi Lu, Jinan, Shandong 250012 (China); Gong, Yaoqin, E-mail: yxg8@sdu.edu.cn [Key Laboratory of Experimental Teratology, MOE, Institute of Molecular Medicine and Genetics, Shandong University, 44 Wen Hua Xi Lu, Jinan, Shandong 250012 (China); Shao, Changshun, E-mail: shao@biology.rutgers.edu [Key Laboratory of Experimental Teratology, MOE, Institute of Molecular Medicine and Genetics, Shandong University, 44 Wen Hua Xi Lu, Jinan, Shandong 250012 (China); Department of Genetics, Rutgers University, Piscataway, NJ 08854 (United States)

    2009-10-15

    Resveratrol has been shown to possess many health-benefiting effects, including the promotion of bone formation. In this report we investigated the mechanism by which resveratrol promotes osteoblastic differentiation from pluripotent mesenchymal cells. Since Wnt signaling is well documented to induce osteoblastogenesis and bone formation, we characterized the factors involved in Wnt signaling in response to resveratrol treatment. Resveratrol treatment of mesenchymal cells led to an increase in stabilization and nuclear accumulation of {beta}-catenin dose-dependently and time-dependently. As a consequence of the increased nuclear accumulation of {beta}-catenin, the ability to activate transcription of {beta}-catenin-TCF/LEF target genes that are required for osteoblastic differentiation was upregulated. However, resveratrol did not affect the initial step of the Wnt signaling pathway, as resveratrol was as effective in upregulating the activity of {beta}-catenin in cells in which Lrp5 was knocked down as in control cells. In addition, while conditioned medium enriched in Wnt signaling antagonist Dkk1 was able to inhibit Wnt3a-induced {beta}-catenin upregulation, this inhibitory effect can be abolished in resveratrol-treated cells. Furthermore, we showed that the level of glycogen synthase kinase 3{beta} (GSK-3{beta}), which phosphorylates and destabilizes {beta}-catenin, was reduced in response to resveratrol treatment. The phosphorylation of GSK-3{beta} requires extracellular signal-regulated kinase (ERK)1/2. Together, our data indicate that resveratrol promotes osteoblastogenesis and bone formation by augmenting Wnt signaling.

  14. NFAT5 regulates the canonical Wnt pathway and is required for cardiomyogenic differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Adachi, Atsuo [Department of Cardiovascular Medicine, Kyoto Prefectural University of Medicine, Kyoto 602-8566 (Japan); Takahashi, Tomosaburo, E-mail: ttaka@koto.kpu-m.ac.jp [Department of Cardiovascular Medicine, Kyoto Prefectural University of Medicine, Kyoto 602-8566 (Japan); Ogata, Takehiro; Imoto-Tsubakimoto, Hiroko; Nakanishi, Naohiko [Department of Cardiovascular Medicine, Kyoto Prefectural University of Medicine, Kyoto 602-8566 (Japan); Ueyama, Tomomi, E-mail: toueyama-circ@umin.ac.jp [Department of Cardiovascular Medicine, Kyoto Prefectural University of Medicine, Kyoto 602-8566 (Japan); Matsubara, Hiroaki [Department of Cardiovascular Medicine, Kyoto Prefectural University of Medicine, Kyoto 602-8566 (Japan)

    2012-09-28

    Highlights: Black-Right-Pointing-Pointer NFAT5 protein expression is downregulated during cardiomyogenesis. Black-Right-Pointing-Pointer Inhibition of NFAT5 function suppresses canonical Wnt signaling. Black-Right-Pointing-Pointer Inhibition of NFAT5 function attenuates mesodermal induction. Black-Right-Pointing-Pointer NFAT5 function is required for cardiomyogenesis. -- Abstract: While nuclear factor of activated T cells 5 (NFAT5), a transcription factor implicated in osmotic stress response, is suggested to be involved in other processes such as migration and proliferation, its role in cardiomyogenesis is largely unknown. Here, we examined the role of NFAT5 in cardiac differentiation of P19CL6 cells, and observed that it was abundantly expressed in undifferentiated P19CL6 cells, and its protein expression was significantly downregulated by enhanced proteasomal degradation during DMSO-induced cardiomyogenesis. Expression of a dominant negative mutant of NFAT5 markedly attenuated cardiomyogenesis, which was associated with the inhibition of mesodermal differentiation. TOPflash reporter assay revealed that the transcriptional activity of canonical Wnt signaling was activated prior to mesodermal differentiation, and this activation was markedly attenuated by NFAT5 inhibition. Pharmacological activation of canonical Wnt signaling by [2 Prime Z, 3 Prime E]-6-bromoindirubin-3 Prime -oxime (BIO) restored Brachyury expression in NFAT5DN-expressing cells. Inhibition of NFAT5 markedly attenuated Wnt3 and Wnt3a induction. Expression of Dkk1 and Cerberus1, which are secreted Wnt antagonists, was also inhibited by NFAT5 inhibition. Thus, endogenous NFAT5 regulates the coordinated expression of Wnt ligands and antagonists, which are essential for cardiomyogenesis through the canonical Wnt pathway. These results demonstrated a novel role of NFAT5 in cardiac differentiation of stem cells.

  15. A proteomic analysis of LRRK2 binding partners reveals interactions with multiple signaling components of the WNT/PCP pathway.

    Science.gov (United States)

    Salašová, Alena; Yokota, Chika; Potěšil, David; Zdráhal, Zbyněk; Bryja, Vítězslav; Arenas, Ernest

    2017-07-11

    Autosomal-dominant mutations in the Park8 gene encoding Leucine-rich repeat kinase 2 (LRRK2) have been identified to cause up to 40% of the genetic forms of Parkinson's disease. However, the function and molecular pathways regulated by LRRK2 are largely unknown. It has been shown that LRRK2 serves as a scaffold during activation of WNT/β-catenin signaling via its interaction with the β-catenin destruction complex, DVL1-3 and LRP6. In this study, we examine whether LRRK2 also interacts with signaling components of the WNT/Planar Cell Polarity (WNT/PCP) pathway, which controls the maturation of substantia nigra dopaminergic neurons, the main cell type lost in Parkinson's disease patients. Co-immunoprecipitation and tandem mass spectrometry was performed in a mouse substantia nigra cell line (SN4741) and human HEK293T cell line in order to identify novel LRRK2 binding partners. Inhibition of the WNT/β-catenin reporter, TOPFlash, was used as a read-out of WNT/PCP pathway activation. The capacity of LRRK2 to regulate WNT/PCP signaling in vivo was tested in Xenopus laevis' early development. Our proteomic analysis identified that LRRK2 interacts with proteins involved in WNT/PCP signaling such as the PDZ domain-containing protein GIPC1 and Integrin-linked kinase (ILK) in dopaminergic cells in vitro and in the mouse ventral midbrain in vivo. Moreover, co-immunoprecipitation analysis revealed that LRRK2 binds to two core components of the WNT/PCP signaling pathway, PRICKLE1 and CELSR1, as well as to FLOTILLIN-2 and CULLIN-3, which regulate WNT secretion and inhibit WNT/β-catenin signaling, respectively. We also found that PRICKLE1 and LRRK2 localize in signalosomes and act as dual regulators of WNT/PCP and β-catenin signaling. Accordingly, analysis of the function of LRRK2 in vivo, in X. laevis revelaed that LRKK2 not only inhibits WNT/β-catenin pathway, but induces a classical WNT/PCP phenotype in vivo. Our study shows for the first time that LRRK2 activates the WNT

  16. The Wnt pathway controls cell death engulfment, spindle orientation, and migration through CED-10/Rac.

    Directory of Open Access Journals (Sweden)

    Juan Cabello

    2010-02-01

    Full Text Available Wnt signalling pathways have extremely diverse functions in animals, including induction of cell fates or tumours, guidance of cell movements during gastrulation, and the induction of cell polarity. Wnt can induce polar changes in cellular morphology by a remodelling of the cytoskeleton. However, how activation of the Frizzled receptor induces cytoskeleton rearrangement is not well understood. We show, by an in depth 4-D microscopy analysis, that the Caenorhabditis elegans Wnt pathway signals to CED-10/Rac via two separate branches to regulate modulation of the cytoskeleton in different cellular situations. Apoptotic cell clearance and migration of the distal tip cell require the MOM-5/Fz receptor, GSK-3 kinase, and APC/APR-1, which activate the CED-2/5/12 branch of the engulfment machinery. MOM-5 (Frizzled thus can function as an engulfment receptor in C. elegans. Our epistatic analyses also suggest that the two partially redundant signalling pathways defined earlier for engulfment may act in a single pathway in early embryos. By contrast, rearrangement of mitotic spindles requires the MOM-5/Fz receptor, GSK-3 kinase, and beta-catenins, but not the downstream factors LIT-1/NLK or POP-1/Tcf. Taken together, our results indicate that in multiple developmental processes, CED-10/Rac can link polar signals mediated by the Wnt pathway to rearrangements of the cytoskeleton.

  17. DIXDC1 activates the Wnt signaling pathway and promotes gastric cancer cell invasion and metastasis.

    Science.gov (United States)

    Tan, Cong; Qiao, Fan; Wei, Ping; Chi, Yayun; Wang, Weige; Ni, Shujuan; Wang, Qifeng; Chen, Tongzhen; Sheng, Weiqi; Du, Xiang; Wang, Lei

    2016-04-01

    DIXDC1 (Dishevelled-Axin domain containing 1) is a DIX (Dishevelled-Axin) domain-possessing protein that promotes colon cancer cell proliferation and increases the invasion and migration ability of non-small-cell lung cancer via the PI3K pathway. As a positive regulator of the Wnt/β-catenin pathway, the biological role of DIXDC1 in human gastric cancer and the relationship between DIXDC1 and the Wnt pathway are unclear. In the current study, the upregulation of DIXDC1 was detected in gastric cancer and was associated with advanced TNM stage cancer, lymph node metastasis, and poor prognosis. We also found that the overexpression of DIXDC1 could promote the invasion and migration of gastric cancer cells. The upregulation of MMPs and the downregulation of E-cadherin were found to be involved in the process. DIXDC1 enhanced β-catenin nuclear accumulation, which activated the Wnt pathway. Additionally, the inhibition of β-catenin in DIXDC1-overexpressing cells reversed the metastasis promotion effects of DIXDC1. These results demonstrate that the expression of DIXDC1 is associated with poor prognosis of gastric cancer patients and that DIXDC1 promotes gastric cancer invasion and metastasis through the activation of the Wnt pathway; E-cadherin and MMPs are also involved in this process. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  18. Cross-regulation of signaling pathways: An example of nuclear hormone receptors and the canonical Wnt pathway

    Energy Technology Data Exchange (ETDEWEB)

    Beildeck, Marcy E. [Lombardi Comprehensive Cancer Center, Georgetown University, 3970 Reservoir Road, NW, Washington, DC 20057 (United States); Gelmann, Edward P. [Columbia University, Department of Medicine, New York, NY (United States); Byers, Stephen W., E-mail: byerss@georgetown.edu [Lombardi Comprehensive Cancer Center, Georgetown University, 3970 Reservoir Road, NW, Washington, DC 20057 (United States)

    2010-07-01

    Predicting the potential physiological outcome(s) of any given molecular pathway is complex because of cross-talk with other pathways. This is particularly evident in the case of the nuclear hormone receptor and canonical Wnt pathways, which regulate cell growth and proliferation, differentiation, apoptosis, and metastatic potential in numerous tissues. These pathways are known to intersect at many levels: in the intracellular space, at the membrane, in the cytoplasm, and within the nucleus. The outcomes of these interactions are important in the control of stem cell differentiation and maintenance, feedback loops, and regulating oncogenic potential. The aim of this review is to demonstrate the importance of considering pathway cross-talk when predicting functional outcomes of signaling, using nuclear hormone receptor/canonical Wnt pathway cross-talk as an example.

  19. Wnt-signalling pathways and microRNAs network in carcinogenesis: experimental and bioinformatics approaches.

    Science.gov (United States)

    Onyido, Emenike K; Sweeney, Eloise; Nateri, Abdolrahman Shams

    2016-09-02

    Over the past few years, microRNAs (miRNAs) have not only emerged as integral regulators of gene expression at the post-transcriptional level but also respond to signalling molecules to affect cell function(s). miRNAs crosstalk with a variety of the key cellular signalling networks such as Wnt, transforming growth factor-β and Notch, control stem cell activity in maintaining tissue homeostasis, while if dysregulated contributes to the initiation and progression of cancer. Herein, we overview the molecular mechanism(s) underlying the crosstalk between Wnt-signalling components (canonical and non-canonical) and miRNAs, as well as changes in the miRNA/Wnt-signalling components observed in the different forms of cancer. Furthermore, the fundamental understanding of miRNA-mediated regulation of Wnt-signalling pathway and vice versa has been significantly improved by high-throughput genomics and bioinformatics technologies. Whilst, these approaches have identified a number of specific miRNA(s) that function as oncogenes or tumour suppressors, additional analyses will be necessary to fully unravel the links among conserved cellular signalling pathways and miRNAs and their potential associated components in cancer, thereby creating therapeutic avenues against tumours. Hence, we also discuss the current challenges associated with Wnt-signalling/miRNAs complex and the analysis using the biomedical experimental and bioinformatics approaches.

  20. Association of single nucleotide polymorphisms in Wnt signaling pathway genes with breast cancer in Saudi patients.

    Directory of Open Access Journals (Sweden)

    Mohammad Saud Alanazi

    Full Text Available Breast cancer is a complex heterogeneous disease involving genetic and epigenetic alterations in genes encoding proteins that are components of various signaling pathways. Candidate gene approach have identified association of genetic variants in the Wnt signaling pathway genes and increased susceptibility to several diseases including breast cancer. Due to the rarity of somatic mutations in key genes of Wnt pathway, we investigated the association of genetic variants in these genes with predisposition to breast cancers. We performed a case-control study to identify risk variants by examining 15 SNPs located in 8 genes associated with Wnt signaling. Genotypic analysis of individual locus showed statistically significant association of five SNPs located in β-catenin, AXIN2, DKK3, SFRP3 and TCF7L2 with breast cancers. Increased risk was observed only with the SNP in β-catenin while the other four SNPs conferred protection against breast cancers. Majority of these associations persisted after stratification of the cases based on estrogen receptor status and age of on-set of breast cancer. The rs7775 SNP in exon 6 of SFRP3 gene that codes for either arginine or glycine exhibited very strong association with breast cancer, even after Bonferroni's correction. Apart from these five variants, rs3923086 in AXIN2 and rs3763511 in DKK4 that did not show any association in the overall population were significantly associated with early on-set and estrogen receptor negative breast cancers, respectively. This is the first study to utilize pathway based approach to identify association of risk variants in the Wnt signaling pathway genes with breast cancers. Confirmation of our findings in larger populations of different ethnicities would provide evidence for the role of Wnt pathway as well as screening markers for early detection of breast carcinomas.

  1. The canonical Wnt signaling pathway plays an important role in lymphopoiesis and hematopoiesis

    NARCIS (Netherlands)

    F.J.T. Staal (Frank); J.M. Sen (Jyoti Misra)

    2008-01-01

    textabstractThe evolutionarily conserved canonical Wnt-β-catenin-T cell factor (TCF)/lymphocyte enhancer binding factor (LEF) signaling pathway regulates key checkpoints in the development of various tissues. Therefore, it is not surprising that a large body of gain-of-function and loss-of-function

  2. Aberrant Wnt signaling pathway in medial temporal lobe structures of Alzheimer's disease

    DEFF Research Database (Denmark)

    Riise, Jesper; Plath, Niels; Pakkenberg, Bente

    2015-01-01

    Cognitive decline is a cardinal feature of Alzheimer’s disease (AD) predominantly linked to synaptic failure, disrupted network connectivity and neurodegeneration. A large body of evidence associates the Wnt pathway with synaptic modulation and cognitive processes, suggesting a potential role...... as a therapeutic target for the treatment of patients....

  3. Regorafenib inhibited gastric cancer cells growth and invasion via CXCR4 activated Wnt pathway.

    Science.gov (United States)

    Lin, Xiao-Lin; Xu, Qi; Tang, Lei; Sun, Li; Han, Ting; Wang, Li-Wei; Xiao, Xiu-Ying

    2017-01-01

    Regorafenib is an oral small-molecule multi kinase inhibitor. Recently, several clinical trials have revealed that regorafenib has an anti-tumor activity in gastric cancer. However, only part of patients benefit from regorafenib, and the mechanisms of regorafenib's anti-tumor effect need further demonstrating. In this study, we would assess the potential anti-tumor effects and the underlying mechanisms of regorafenib in gastric cancer cells, and explore novel biomarkers for patients selecting of regorafenib. The anti-tumor effects of regorafenib on gastric cancer cells were analyzed via cell proliferation and invasion. The underlying mechanisms were demonstrated using molecular biology techniques. We found that regorafenib inhibited cell proliferation and invasion at the concentration of 20μmol/L and in a dose dependent manner. The anti-tumor effects of regorafenib related to the decreased expression of CXCR4, and elevated expression and activation of CXCR4 could reverse the inhibition effect of regorafenib on gastric cancer cells. Further studies revealed that regorafenib reduced the transcriptional activity of Wnt/β-Catenin pathway and led to decreased expression of Wnt pathway target genes, while overexpression and activation of CXCR4 could attenuate the inhibition effect of regorafenib on Wnt/β-Catenin pathway. Our findings demonstrated that regorafenib effectively inhibited cell proliferation and invasion of gastric cancer cells via decreasing the expression of CXCR4 and further reducing the transcriptional activity of Wnt/β-Catenin pathway.

  4. Alzheimer disease: crosstalk between the canonical Wnt/beta-catenin pathway and PPARs alpha and gamma

    Directory of Open Access Journals (Sweden)

    Alexandre VALLEE

    2016-10-01

    Full Text Available The molecular mechanisms underlying the pathophysiology of Alzheimer's disease (AD are still not fully understood. In AD, Wnt/beta-catenin signaling has been shown to be downregulated while the peroxisome proliferator-activated receptor (PPAR gamma (mARN and protein is upregulated. Certain neurodegenerative diseases share the same Wnt/beta-catenin/PPAR gamma profile, such as bipolar disorder and schizophrenia. Conversely, other NDs share an opposite profile, such as amyotrophic lateral sclerosis, Parkinson's disease, Huntington's disease, multiple sclerosis and Friedreich's ataxia. AD is characterized by the deposition of extracellular Abeta plaques and the formation of intracellular neurofibrillary tangles in the central nervous system . Activation of Wnt signaling or inhibition of both glycogen synthase kinase-3beta and Dickkopf 1, two key negative regulators of the canonical Wnt pathway, are able to protect against Abeta neurotoxicity and to ameliorate cognitive performance in AD patients. Although PPAR gamma is upregulated in AD patients, and despite the fact that it has been shown that the PPAR gamma and Wnt/beta catenin pathway systems work in an opposite manner, PPAR gamma agonists diminish learning and memory deficits, decrease Abeta activation of microglia, and prevent hippocampal and cortical neurons from dying. These beneficial effects observed in AD transgenic mice and patients might be partially due to the anti-inflammatory properties of PPAR gamma agonists. Moreover, activation of PPAR alpha upregulates transcription of the alpha-secretase gene and represents a new therapeutic treatment for AD. This review focuses largely on the behavior of two opposing pathways in AD, namely Wnt/beta-catenin signaling and PPAR gamma. It is hoped that this approach may help to develop novel AD therapeutic strategies integrating PPAR alpha signaling.

  5. Hyaluronic acid enhances proliferation of human amniotic mesenchymal stem cells through activation of Wnt/β-catenin signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ru-Ming; Sun, Ren-Gang; Zhang, Ling-Tao; Zhang, Qing-Fang; Chen, Dai-Xiong [Guizhou Center for Translational Medicine, Affiliated Hospital of Zunyi Medical University, 149 Dalian Road, Zunyi 563000 (China); Zhong, Jian-Jiang, E-mail: jjzhong@sjtu.edu.cn [State Key Laboratory of Microbial Metabolism, and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai 200240 (China); Xiao, Jian-Hui, E-mail: jhxiao@yahoo.com [Guizhou Center for Translational Medicine, Affiliated Hospital of Zunyi Medical University, 149 Dalian Road, Zunyi 563000 (China)

    2016-07-15

    This study investigated the pro-proliferative effect of hyaluronic acid (HA) on human amniotic mesenchymal stem cells (hAMSCs) and the underlying mechanisms. Treatment with HA increased cell population growth in a dose- and time-dependent manner. Analyses by flow cytometry and immunocytochemistry revealed that HA did not change the cytophenotypes of hAMSCs. Additionally, the osteogenic, chondrogenic, and adipogenic differentiation capabilities of these hAMSCs were retained after HA treatment. Moreover, HA increased the mRNA expressions of wnt1, wnt3a, wnt8a, cyclin D1, Ki-67, and β-catenin as well as the protein level of β-catenin and cyclin D1 in hAMSCs; and the nuclear localization of β-catenin was also enhanced. Furthermore, the pro-proliferative effect of HA and up-regulated expression of Wnt/β-catenin pathway-associated proteins - wnt3a, β-catenin and cyclin D1 in hAMSCs were significantly inhibited upon pre-treatment with Wnt-C59, an inhibitor of the Wnt/β-catenin pathway. These results suggest that HA may positively regulate hAMSCs proliferation through regulation of the Wnt/β-catenin signaling pathway. - Highlights: • Hyaluronic acid (HA) could promote the proliferation of hAMSCs. • HA treatment dose not affect the pluripotency of hAMSCs. • HA increases hAMSCs proliferation through activation of Wnt/β-catenin signaling.

  6. Jagged1 is the pathological link between Wnt and Notch pathways in colorectal cancer.

    Science.gov (United States)

    Rodilla, Verónica; Villanueva, Alberto; Obrador-Hevia, Antonia; Robert-Moreno, Alex; Fernández-Majada, Vanessa; Grilli, Andrea; López-Bigas, Nuria; Bellora, Nicolás; Albà, M Mar; Torres, Ferran; Duñach, Mireia; Sanjuan, Xavier; Gonzalez, Sara; Gridley, Thomas; Capella, Gabriel; Bigas, Anna; Espinosa, Lluís

    2009-04-14

    Notch has been linked to beta-catenin-dependent tumorigenesis; however, the mechanisms leading to Notch activation and the contribution of the Notch pathway to colorectal cancer is not yet understood. By microarray analysis, we have identified a group of genes downstream of Wnt/beta-catenin (down-regulated when blocking Wnt/beta-catenin) that are directly regulated by Notch (repressed by gamma-secretase inhibitors and up-regulated by active Notch1 in the absence of beta-catenin signaling). We demonstrate that Notch is downstream of Wnt in colorectal cancer cells through beta-catenin-mediated transcriptional activation of the Notch-ligand Jagged1. Consistently, expression of activated Notch1 partially reverts the effects of blocking Wnt/beta-catenin pathway in tumors implanted s.c. in nude mice. Crossing APC(Min/+) with Jagged1(+/Delta) mice is sufficient to significantly reduce the size of the polyps arising in the APC mutant background indicating that Notch is an essential modulator of tumorigenesis induced by nuclear beta-catenin. We show that this mechanism is operating in human tumors from Familial Adenomatous Polyposis patients. We conclude that Notch activation, accomplished by beta-catenin-mediated up-regulation of Jagged1, is required for tumorigenesis in the intestine. The Notch-specific genetic signature is sufficient to block differentiation and promote vasculogenesis in tumors whereas proliferation depends on both pathways.

  7. The role of the Wnt signaling pathway in cancer stem cells: prospects for drug development.

    Science.gov (United States)

    Kim, Yong-Mi; Kahn, Michael

    Cancer stem cells (CSCs), also known as tumor initiating cells are now considered to be the root cause of most if not all cancers, evading treatment and giving rise to disease relapse. They have become a central focus in new drug development. Prospective identification, understanding the key pathways that maintain CSCs, and being able to target CSCs, particularly if the normal stem cell population could be spared, could offer an incredible therapeutic advantage. The Wnt signaling cascade is critically important in stem cell biology, both in homeostatic maintenance of tissues and organs through their respective somatic stem cells and in the CSC/tumor initiating cell population. Aberrant Wnt signaling is associated with a wide array of tumor types. Therefore, the ability to safely target the Wnt signaling pathway offers enormous promise to target CSCs. However, just like the sword of Damocles, significant risks and concerns regarding targeting such a critical pathway in normal stem cell maintenance and tissue homeostasis remain ever present. With this in mind, we review recent efforts in modulating the Wnt signaling cascade and critically analyze therapeutic approaches at various stages of development.

  8. Parameter-free methods distinguish Wnt pathway models and guide design of experiments

    KAUST Repository

    MacLean, Adam L.

    2015-02-17

    The canonical Wnt signaling pathway, mediated by β-catenin, is crucially involved in development, adult stem cell tissue maintenance, and a host of diseases including cancer. We analyze existing mathematical models of Wnt and compare them to a new Wnt signaling model that targets spatial localization; our aim is to distinguish between the models and distill biological insight from them. Using Bayesian methods we infer parameters for each model from mammalian Wnt signaling data and find that all models can fit this time course. We appeal to algebraic methods (concepts from chemical reaction network theory and matroid theory) to analyze the models without recourse to specific parameter values. These approaches provide insight into aspects of Wnt regulation: the new model, via control of shuttling and degradation parameters, permits multiple stable steady states corresponding to stem-like vs. committed cell states in the differentiation hierarchy. Our analysis also identifies groups of variables that should be measured to fully characterize and discriminate between competing models, and thus serves as a guide for performing minimal experiments for model comparison.

  9. Thermodynamics in Gliomas: Interactions between the Canonical WNT/Beta-Catenin Pathway and PPAR Gamma

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    Alexandre Vallée

    2017-05-01

    Full Text Available Gliomas cells are the site of numerous metabolic and thermodynamics abnormalities with an increasing entropy rate which is characteristic of irreversible processes driven by changes in Gibbs energy, heat production, intracellular acidity, membrane potential gradient, and ionic conductance. We focus our review on the opposing interactions observed in glioma between the canonical WNT/beta-catenin pathway and PPAR gamma and their metabolic and thermodynamic implications. In gliomas, WNT/beta-catenin pathway is upregulated while PPAR gamma is downregulated. Upregulation of WNT/beta-catenin signaling induces changes in key metabolic enzyme that modify their thermodynamics behavior. This leads to activation pyruvate dehydrogenase kinase 1(PDK-1 and monocarboxylate lactate transporter 1 (MCT-1. Consequently, phosphorylation of PDK-1 inhibits pyruvate dehydrogenase complex (PDH. Thus, a large part of pyruvate cannot be converted into acetyl-CoA in mitochondria and in TCA (tricarboxylic acid cycle. This leads to aerobic glycolysis despite the availability of oxygen, named Warburg effect. Cytoplasmic pyruvate is, in major part, converted into lactate. The WNT/beta-catenin pathway induces also the transcription of genes involved in cell proliferation, cell invasiveness, nucleotide synthesis, tumor growth, and angiogenesis, such as c-Myc, cyclin D1, PDK. In addition, in gliomas cells, PPAR gamma is downregulated, leading to a decrease in insulin sensitivity and an increase in neuroinflammation. Moreover, PPAR gamma contributes to regulate some key circadian genes. Abnormalities in the regulation of circadian rhythms and dysregulation in circadian clock genes are observed in gliomas. Circadian rhythms are dissipative structures, which play a key role in far-from-equilibrium thermodynamics through their interactions with WNT/beta-catenin pathway and PPAR gamma. In gliomas, metabolism, thermodynamics, and circadian rhythms are tightly interrelated.

  10. Wnt5a regulates the cell proliferation and adipogenesis via MAPK-independent pathway in early stage of obesity.

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    Tang, Qi; Chen, Chang; Zhang, Yan; Dai, Minjia; Jiang, Yichen; Wang, Hang; Yu, Mei; Jing, Wei; Tian, Weidong

    2017-08-29

    The early stage of obesity is an important stage in the development of obesity. However, there are few studies which explored the property or changes in obesity at early stage especially involving Wnt5a. The associated gene expression of Wnt5a on cell regeneration and the effect of Wnt5a on rat adipose-derived stem cell (rASC) proliferation and adipogenesis need additional study. Here, we investigated the changes in obesity at early stage and how Wnt5a regulates rASC regeneration, proliferation, and adipogenesis. Our data revealed that obesity at early stage measured by Lee index presented a state with impaired adipogenesis and more infiltrated inflammatory cells but without significant changes in adipocyte sizes and inflammatory factors. The process might be associated with anti-canonical Wnt pathway and a reciprocal Wnt5a/JNK pathway. Besides the gene expression of Wnt5a decreased from cell passage 1 to passage 3. The cell proliferation was regulated by increasing dose of Wnt5a with the maximal effect at 50 ng/mL and 50 ng/mL Wnt5a suppressed adipogenic differentiation at middle-late stage of adipogenesis via anti-β-catenin and a mitogen-activated protein kinase (MAPK) signaling-independent manner. Accordingly, the research helps to gain further insights into the early stage of obesity and its associated changes on a cellular and molecular level. © 2017 International Federation for Cell Biology.

  11. Wnt/Tcf1 pathway restricts embryonic stem cell cycle through activation of the Ink4/Arf locus

    Science.gov (United States)

    Griego, Anna; Cerrato, Aniello; Cosma, Maria Pia

    2017-01-01

    Understanding the mechanisms regulating cell cycle, proliferation and potency of pluripotent stem cells guarantees their safe use in the clinic. Embryonic stem cells (ESCs) present a fast cell cycle with a short G1 phase. This is due to the lack of expression of cell cycle inhibitors, which ultimately determines naïve pluripotency by holding back differentiation. The canonical Wnt/β-catenin pathway controls mESC pluripotency via the Wnt-effector Tcf3. However, if the activity of the Wnt/β-catenin controls the cell cycle of mESCs remains unknown. Here we show that the Wnt-effector Tcf1 is recruited to and triggers transcription of the Ink4/Arf tumor suppressor locus. Thereby, the activation of the Wnt pathway, a known mitogenic pathway in somatic tissues, restores G1 phase and drastically reduces proliferation of mESCs without perturbing pluripotency. Tcf1, but not Tcf3, is recruited to a palindromic motif enriched in the promoter of cell cycle repressor genes, such as p15Ink4b, p16Ink4a and p19Arf, which mediate the Wnt-dependent anti-proliferative effect in mESCs. Consistently, ablation of β-catenin or Tcf1 expression impairs Wnt-dependent cell cycle regulation. All together, here we showed that Wnt signaling controls mESC pluripotency and proliferation through non-overlapping functions of distinct Tcf factors. PMID:28346462

  12. Nucleotide variants of genes encoding components of the Wnt signalling pathway and the risk of non-syndromic tooth agenesis.

    Science.gov (United States)

    Mostowska, A; Biedziak, B; Zadurska, M; Dunin-Wilczynska, I; Lianeri, M; Jagodzinski, P P

    2013-11-01

    Tooth agenesis is one of the most common dental anomalies, with a complex and not yet fully elucidated aetiology. Given the crucial role of the Wnt signalling pathway during tooth development, the purpose of this study was to determine whether nucleotide variants of genes encoding components of this signalling pathway might be associated with hypodontia and oligodontia in the Polish population. A set of 34 single nucleotide polymorphism (SNPs) in 13 WNT and WNT-related genes were analyzed in a group of 157 patients with tooth agenesis and a properly matched control group (n = 430). In addition, direct sequencing was performed to detect mutations in the MSX1, PAX9 and WNT10A genes. Both single-marker and haplotype analyses showed highly significant association between SNPs in the WNT10A gene and the risk for tooth agenesis. Moreover, nine pathogenic mutations within the coding region of the WNT10A gene were identified in 26 out of 42 (62%) tested patients. One novel heterozygous mutation was identified in the PAX9 gene. Borderline association with the risk of non-syndromic tooth agenesis was also observed for the APC, CTNNB1, DVL2 and WNT11 polymorphisms. In conclusion, nucleotide variants of genes encoding important components of the Wnt signalling pathway might influence the risk of tooth agenesis. © 2012 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. PITX2 and non-canonical Wnt pathway interaction in metastatic prostate cancer.

    Science.gov (United States)

    Vela, I; Morrissey, C; Zhang, X; Chen, S; Corey, E; Strutton, G M; Nelson, C C; Nicol, D L; Clements, J A; Gardiner, E M

    2014-02-01

    The non-canonical Wnt pathway, a regulator of cellular motility and morphology, is increasingly implicated in cancer metastasis. In a quantitative PCR array analysis of 84 Wnt pathway associated genes, both non-canonical and canonical pathways were activated in primary and metastatic tumors relative to normal prostate. Expression of the Wnt target gene PITX2 in a prostate cancer (PCa) bone metastasis was strikingly elevated over normal prostate (over 2,000-fold) and primary prostate cancer (over 200-fold). The elevation of PITX2 protein was also evident on tissue microarrays, with strong PITX2 immunostaining in PCa skeletal and, to a lesser degree, soft tissue metastases. PITX2 is associated with cell migration during normal tissue morphogenesis. In our studies, overexpression of individual PITX2A/B/C isoforms stimulated PC-3 PCa cell motility, with the PITX2A isoform imparting a specific motility advantage in the presence of non-canonical Wnt5a stimulation. Furthermore, PITX2 specific shRNA inhibited PC-3 cell migration toward bone cell derived chemoattractant. These experimental results support a pivotal role of PITX2A and non-canonical Wnt signaling in enhancement of PCa cell motility, suggest PITX2 involvement in homing of PCa to the skeleton, and are consistent with a role for PITX2 in PCa metastasis to soft and bone tissues. Our findings, which significantly expand previous evidence that PITX2 is associated with risk of PCa biochemical recurrence, indicate that variation in PITX2 expression accompanies and may promote prostate tumor progression and metastasis.

  14. Interaction of Wnt pathway related variants with type 2 diabetes in a Chinese Han population

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    Jian-Bo Zhou

    2015-10-01

    Full Text Available Aims. Epistasis from gene set based on the function-related genes may confer to the susceptibility of type 2 diabetes (T2D. The Wnt pathway has been reported to play an important role in the pathogenesis of T2D. Here we applied tag SNPs to explore the association between epistasis among genes from Wnt and T2D in the Han Chinese population. Methods. Variants of fourteen genes selected from Wnt pathways were performed to analyze epistasis. Gene–gene interactions in case-control samples were identified by generalized multifactor dimensionality reduction (GMDR method. We performed a case-controlled association analysis on a total of 1,026 individual with T2D and 1,157 controls via tag SNPs in Wnt pathway. Results. In single-locus analysis, SNPs in four genes were significantly associated with T2D adjusted for multiple testing (rs7903146C in TCF7L2, p = 3.21∗10−3, OR = 1.39, 95% CI [1.31–1.47], rs12904944G in SMAD3, p = 2.51∗10−3, OR = 1.39, 95% CI [1.31–1.47], rs2273368C in WNT2B, p = 4.46∗10−3, OR = 1.23, 95% CI [1.11–1.32], rs6902123C in PPARD, p = 1.14∗10−2, OR = 1.40, 95% CI [1.32–1.48]. The haplotype TGC constructed by TCF7L2 (rs7903146, DKK1 (rs2241529 and BTRC (rs4436485 showed a significant association with T2D (OR = 0.750, 95% CI [0.579–0.972], P = 0.03. For epistasis analysis, the optimized combination was the two locus model of WNT2B rs2273368 and TCF7L2rs7903146, which had the maximum cross-validation consistency. This was 9 out of 10 for the sign test at 0.0107 level. The best combination increased the risk of T2D by 1.47 times (95% CI [1.13–1.91], p = 0.0039. Conclusions. Epistasis between TCF7L2 and WNT2B is associated with the susceptibility of T2D in a Han Chinese population. Our results were compatible with the idea of the complex nature of T2D that would have been missed using conventional tools.

  15. New advances of TMEM88 in cancer initiation and progression, with special emphasis on Wnt signaling pathway.

    Science.gov (United States)

    Ge, Yun-Xuan; Wang, Chang-Hui; Hu, Fu-Yong; Pan, Lin-Xin; Min, Jie; Niu, Kai-Yuan; Zhang, Lei; Li, Jun; Xu, Tao

    2018-01-01

    Transmembrane protein 88 (TMEM88), a newly discovered protein localized on the cell membrane. Recent studies showed that TMEM88 was involved in the regulation of several types of cancer. TMEM88 was expressed at significantly higher levels in breast cancer (BC) cell line than in normal breast cell line with co-localized with Dishevelled (DVL) in the cytoplasm of BC cell line. TMEM88 silencing in the ovarian cancer cell line CP70 resulted in significant upregulation of Wnt downstream genes (c-Myc, cyclin-D1) and other Wnt target genes including JUN, PTIX2, CTNNB1 (β-catenin), further supporting that TMEM88 inhibits canonical Wnt signaling pathway. Wnt signaling pathway has been known to play important roles in many diseases, especially in cancer. For instance, hepatocellular carcinoma (HCC) has become one of the most common tumors harboring mutations in the Wnt signaling pathway. As the inhibitor of Wnt signaling, TMEM88 has been considered to act as an oncogene or a tumor suppressor. Up-regulated TMEM88 or gene therapy approaches could be an effective therapeutic approach against tumor as TMEM88 inhibits Wnt signaling through direct interaction with DVL. Here, we review the current knowledge on the functional role and potential clinical application of TMEM88 in the control of various cancers. Highlights Wnt signaling displays an important role in several pathogenesis of cancer. Wnt signaling pathway is activated during cancer development. TMEM88 has an impact on cancer by inhibiting canonical Wnt signaling. We discuss the importance and new applications of TMEM88 in cancer therapy. © 2017 Wiley Periodicals, Inc.

  16. The Tumor Suppressor BCL7B Functions in the Wnt Signaling Pathway.

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    Tomoko Uehara

    2015-01-01

    Full Text Available Human BCL7 gene family consists of BCL7A, BCL7B, and BCL7C. A number of clinical studies have reported that BCL7 family is involved in cancer incidence, progression, and development. Among them, BCL7B, located on chromosome 7q11.23, is one of the deleted genes in patients with Williams-Beuren syndrome. Although several studies have suggested that malignant diseases occurring in patients with Williams-Beuren syndrome are associated with aberrations in BCL7B, little is known regarding the function of this gene at the cellular level. In this study, we focused on bcl-7, which is the only homolog of BCL7 gene family in Caenorhabditis elegans, and analyzed bcl-7 deletion mutants. As a result, we found that bcl-7 is required for the asymmetric differentiation of epithelial seam cells, which have self-renewal properties as stem cells and divide asymmetrically through the WNT pathway. Distal tip cell development, which is regulated by the WNT pathway in Caenorhabditis elegans, was also affected in bcl-7-knockout mutants. Interestingly, bcl-7 mutants exhibited nuclear enlargement, reminiscent of the anaplastic features of malignant cells. Furthermore, in KATOIII human gastric cancer cells, BCL7B knockdown induced nuclear enlargement, promoted the multinuclei phenotype and suppressed cell death. In addition, this study showed that BCL7B negatively regulates the Wnt-signaling pathway and positively regulates the apoptotic pathway. Taken together, our data indicate that BCL7B/BCL-7 has some roles in maintaining the structure of nuclei and is involved in the modulation of multiple pathways, including Wnt and apoptosis. This study may implicate a risk of malignancies with BCL7B-deficiency, such as Williams-Beuren syndrome.

  17. Temporal Perturbation of the Wnt Signaling Pathway in the Control of Cell Reprogramming Is Modulated by TCF1

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    Francesco Aulicino

    2014-05-01

    Full Text Available Cyclic activation of the Wnt/β-catenin signaling pathway controls cell fusion-mediated somatic cell reprogramming. TCFs belong to a family of transcription factors that, in complex with β-catenin, bind and transcriptionally regulate Wnt target genes. Here, we show that Wnt/β-catenin signaling needs to be off during the early reprogramming phases of mouse embryonic fibroblasts (MEFs into iPSCs. In MEFs undergoing reprogramming, senescence genes are repressed and mesenchymal-to-epithelial transition is favored. This is correlated with a repressive activity of TCF1, which contributes to the silencing of Wnt/β-catenin signaling at the onset of reprogramming. In contrast, the Wnt pathway needs to be active in the late reprogramming phases to achieve successful reprogramming. In conclusion, continued activation or inhibition of the Wnt/β-catenin signaling pathway is detrimental to the reprogramming of MEFs; instead, temporal perturbation of the pathway is essential for efficient reprogramming, and the “Wnt-off” state can be considered an early reprogramming marker.

  18. FGF signaling inhibitor, SPRY4, is evolutionarily conserved target of WNT signaling pathway in progenitor cells.

    Science.gov (United States)

    Katoh, Yuriko; Katoh, Masaru

    2006-03-01

    WNT, FGF and Hedgehog signaling pathways network together during embryogenesis, tissue regeneration, and carcinogenesis. FGF16, FGF18, and FGF20 genes are targets of WNT-mediated TCF/LEF-beta-catenin-BCL9/BCL9L-PYGO transcriptional complex. SPROUTY (SPRY) and SPRED family genes encode inhibitors for receptor tyrosine kinase signaling cascades, such as those of FGF receptor family members and EGF receptor family members. Here, transcriptional regulation of SPRY1, SPRY2, SPRY3, SPRY4, SPRED1, SPRED2, and SPRED3 genes by WNT/beta-catenin signaling cascade was investigated by using bioinformatics and human intelligence (humint). Because double TCF/LEF-binding sites were identified within the 5'-promoter region of human SPRY4 gene, comparative genomics analyses on SPRY4 orthologs were further performed. SPRY4-FGF1 locus at human chromosome 5q31.3 and FGF2-NUDT6-SPATA5-SPRY1 locus at human chromosome 4q27-q28.1 were paralogous regions within the human genome. Chimpanzee SPRY4 gene was identified within NW_107083.1 genome sequence. Human, chimpanzee, rat and mouse SPRY4 orthologs, consisting of three exons, were well conserved. SPRY4 gene was identified as the evolutionarily conserved target of WNT/beta-catenin signaling pathway based on the conservation of double TCF/LEF-binding sites within 5'-promoter region of mammalian SPRY4 orthologs. Human SPRY4 mRNA was expressed in embryonic stem (ES) cells, brain, pancreatic islet, colon cancer, head and neck tumor, melanoma, and pancreatic cancer. WNT signaling activation in progenitor cells leads to the growth regulation of progenitor cells themselves through SPRY4 induction, and also to the growth stimulation of proliferating cells through FGF secretion. Epigenetic silencing and loss-of-function mutations of SPRY4 gene in progenitor cells could lead to carcinogenesis. SPRY4 is the pharmacogenomics target in the fields of oncology and regenerative medicine.

  19. Wnt/β-Catenin Pathway Is Regulated by PITX2 Homeodomain Protein and Thus Contributes to the Proliferation of Human Ovarian Adenocarcinoma Cell, SKOV-3*

    Science.gov (United States)

    Basu, Moitri; Roy, Sib Sankar

    2013-01-01

    Pituitary homeobox-2 (PITX2) plays a substantial role in the development of pituitary, heart, and brain. Although the role of PITX2 isoforms in embryonic development has been extensively studied, its possible involvement in regulating the Wnt signaling pathway has not been reported. Because the Wnt pathway is strongly involved in ovarian development and cancer, we focused on the possible association between PITX2 and Wnt pathway in ovarian carcinoma cells. Remarkably, we found that PITX2 interacts and regulates WNT2/5A/9A/6/2B genes of the canonical, noncanonical, or other pathways in the human ovarian cancer cell SKOV-3. Chromatin immunoprecipitation and promoter-reporter assays further indicated the significant association of PITX2 with WNT2 and WNT5A promoters. Detailed study further reveals that the PITX2 isoform specifically activates the canonical Wnt signaling pathway either directly or through Wnt ligands. Thus, the activated Wnt pathway subsequently enhances cell proliferation. Moreover, we found the activation of Wnt pathway reduces the expression of different FZD receptors that limit further Wnt activation, demonstrating the existence of an auto-regulatory feedback loop. In contrast, PITX2 could not activate the noncanonical pathway as the Wnt5A-specific ROR2 receptor does not express in SKOV-3 cells. Collectively, our findings demonstrated that, despite being a target of the canonical Wnt signaling pathway, PITX2 itself induces the same, thus leading to the activation of the cell cycle regulating genes as well as the proliferation of SKOV-3 cells. Collectively, we highlighted that the PITX2 and Wnt pathway exerts a positive feedback regulation, whereas frizzled receptors generate a negative feedback in this pathway. Our findings will help to understand the molecular mechanism of proliferation in ovarian cancer cells. PMID:23250740

  20. Wnt/β-catenin pathway is regulated by PITX2 homeodomain protein and thus contributes to the proliferation of human ovarian adenocarcinoma cell, SKOV-3.

    Science.gov (United States)

    Basu, Moitri; Roy, Sib Sankar

    2013-02-08

    Pituitary homeobox-2 (PITX2) plays a substantial role in the development of pituitary, heart, and brain. Although the role of PITX2 isoforms in embryonic development has been extensively studied, its possible involvement in regulating the Wnt signaling pathway has not been reported. Because the Wnt pathway is strongly involved in ovarian development and cancer, we focused on the possible association between PITX2 and Wnt pathway in ovarian carcinoma cells. Remarkably, we found that PITX2 interacts and regulates WNT2/5A/9A/6/2B genes of the canonical, noncanonical, or other pathways in the human ovarian cancer cell SKOV-3. Chromatin immunoprecipitation and promoter-reporter assays further indicated the significant association of PITX2 with WNT2 and WNT5A promoters. Detailed study further reveals that the PITX2 isoform specifically activates the canonical Wnt signaling pathway either directly or through Wnt ligands. Thus, the activated Wnt pathway subsequently enhances cell proliferation. Moreover, we found the activation of Wnt pathway reduces the expression of different FZD receptors that limit further Wnt activation, demonstrating the existence of an auto-regulatory feedback loop. In contrast, PITX2 could not activate the noncanonical pathway as the Wnt5A-specific ROR2 receptor does not express in SKOV-3 cells. Collectively, our findings demonstrated that, despite being a target of the canonical Wnt signaling pathway, PITX2 itself induces the same, thus leading to the activation of the cell cycle regulating genes as well as the proliferation of SKOV-3 cells. Collectively, we highlighted that the PITX2 and Wnt pathway exerts a positive feedback regulation, whereas frizzled receptors generate a negative feedback in this pathway. Our findings will help to understand the molecular mechanism of proliferation in ovarian cancer cells.

  1. Telomere protection and TRF2 expression are enhanced by the canonical Wnt signalling pathway.

    Science.gov (United States)

    Diala, Irmina; Wagner, Nicole; Magdinier, Frédérique; Shkreli, Marina; Sirakov, Maria; Bauwens, Serge; Schluth-Bolard, Caroline; Simonet, Thomas; Renault, Valérie M; Ye, Jing; Djerbi, Abdelnnadir; Pineau, Pascal; Choi, Jinkuk; Artandi, Steven; Dejean, Anne; Plateroti, Michelina; Gilson, Eric

    2013-04-01

    The DNA-binding protein TRF2 is essential for telomere protection and chromosome stability in mammals. We show here that TRF2 expression is activated by the Wnt/β-catenin signalling pathway in human cancer and normal cells as well as in mouse intestinal tissues. Furthermore, β-catenin binds to TRF2 gene regulatory regions that are functional in a luciferase transactivating assay. Reduced β-catenin expression in cancer cells triggers a marked increase in telomere dysfunction, which can be reversed by TRF2 overexpression. We conclude that the Wnt/β-catenin signalling pathway maintains a level of TRF2 critical for telomere protection. This is expected to have an important role during development, adult stem cell function and oncogenesis.

  2. KCTD1 suppresses canonical Wnt signaling pathway by enhancing β-catenin degradation.

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    Xinxin Li

    Full Text Available The canonical Wnt signaling pathway controls normal embryonic development, cellular proliferation and growth, and its aberrant activity results in human carcinogenesis. The core component in regulation of this pathway is β-catenin, but molecular regulation mechanisms of β-catenin stability are not completely known. Here, our recent studies have shown that KCTD1 strongly inhibits TCF/LEF reporter activity. Moreover, KCTD1 interacted with β-catenin both in vivo by co-immunoprecipitation as well as in vitro through GST pull-down assays. We further mapped the interaction regions to the 1-9 armadillo repeats of β-catenin and the BTB domain of KCTD1, especially Position Ala-30 and His-33. Immunofluorescence analysis indicated that KCTD1 promotes the cytoplasmic accumulation of β-catenin. Furthermore, protein stability assays revealed that KCTD1 enhances the ubiquitination/degradation of β-catenin in a concentration-dependent manner in HeLa cells. And the degradation of β-catenin mediated by KCTD1 was alleviated by the proteasome inhibitor, MG132. In addition, KCTD1-mediated β-catenin degradation was dependent on casein kinase 1 (CK1- and glycogen synthase kinase-3β (GSK-3β-mediated phosphorylation and enhanced by the E3 ubiquitin ligase β-transducin repeat-containing protein (β-TrCP. Moreover, KCTD1 suppressed the expression of endogenous Wnt downstream genes and transcription factor AP-2α. Finally, we found that Wnt pathway member APC and tumor suppressor p53 influence KCTD1-mediated downregulation of β-catenin. These results suggest that KCTD1 functions as a novel inhibitor of Wnt signaling pathway.

  3. Highly conserved molecular pathways, including Wnt signaling, promote functional recovery from spinal cord injury in lampreys.

    Science.gov (United States)

    Herman, Paige E; Papatheodorou, Angelos; Bryant, Stephanie A; Waterbury, Courtney K M; Herdy, Joseph R; Arcese, Anthony A; Buxbaum, Joseph D; Smith, Jeramiah J; Morgan, Jennifer R; Bloom, Ona

    2018-01-15

    In mammals, spinal cord injury (SCI) leads to dramatic losses in neurons and synaptic connections, and consequently function. Unlike mammals, lampreys are vertebrates that undergo spontaneous regeneration and achieve functional recovery after SCI. Therefore our goal was to determine the complete transcriptional responses that occur after SCI in lampreys and to identify deeply conserved pathways that promote regeneration. We performed RNA-Seq on lamprey spinal cord and brain throughout the course of functional recovery. We describe complex transcriptional responses in the injured spinal cord, and somewhat surprisingly, also in the brain. Transcriptional responses to SCI in lampreys included transcription factor networks that promote peripheral nerve regeneration in mammals such as Atf3 and Jun. Furthermore, a number of highly conserved axon guidance, extracellular matrix, and proliferation genes were also differentially expressed after SCI in lampreys. Strikingly, ~3% of differentially expressed transcripts belonged to the Wnt pathways. These included members of the Wnt and Frizzled gene families, and genes involved in downstream signaling. Pharmacological inhibition of Wnt signaling inhibited functional recovery, confirming a critical role for this pathway. These data indicate that molecular signals present in mammals are also involved in regeneration in lampreys, supporting translational relevance of the model.

  4. Lhx8 mediated Wnt and TGFβ pathways in tooth development and regeneration.

    Science.gov (United States)

    Zhou, Chen; Yang, Guodong; Chen, Mo; Wang, Chenglin; He, Ling; Xiang, Lusai; Chen, Danying; Ling, Junqi; Mao, Jeremy J

    2015-09-01

    LIM homeobox 8 (Lhx8) is a highly conserved transcriptional factor with recently illustrated roles in cholinergic and GABAergic differentiation, and is expressed in neural crest derived craniofacial tissues during development. However, Lhx8 functions and signaling pathways are largely elusive. Here we showed that Lhx8 regulates dental mesenchyme differentiation and function via Wnt and TGFβ pathways. Lhx8 expression was restricted to dental mesenchyme from E11.5 to a peak at E14.5, and absent in dental epithelium. By reconstituting dental epithelium and mesenchyme in an E16.5 tooth organ, Lhx8 knockdown accelerated dental mesenchyme differentiation; conversely, Lhx8 overexpression attenuated dentin formation. Lhx8 overexpressed adult human dental pulp stem/progenitor cells in β-tricalcium phosphate cubes attenuated mineralized matrix production in vivo. Gene profiling revealed that postnatal dental pulp stem/progenitor cells upon Lhx8 overexpression modified matrix related gene expression including Dspp, Cola1 and osteocalcin. Lhx8 transcriptionally activated Wnt and TGFβ pathways, and its attenuation upregulated multiple dentinogenesis genes. Together, Lhx8 regulates dentin development and regeneration by fine-turning Wnt and TGFβ signaling. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Transcriptional cooperation between the transforming growth factor-beta and Wnt pathways in mammary and intestinal tumorigenesis.

    Science.gov (United States)

    Labbé, Etienne; Lock, Lisa; Letamendia, Ainhoa; Gorska, Agnieszka E; Gryfe, Robert; Gallinger, Steven; Moses, Harold L; Attisano, Liliana

    2007-01-01

    Transforming growth factor-beta (TGF-beta) and Wnt ligands function in numerous developmental processes, and alterations of both signaling pathways are associated with common pathologic conditions, including cancer. To obtain insight into the extent of interdependence of the two signaling cascades in regulating biological responses, we used an oligonucleotide microarray approach to identify Wnt and TGF-beta target genes using normal murine mammary gland epithelial cells as a model. Combination treatment of TGF-beta and Wnt revealed a novel transcriptional program that could not have been predicted from single ligand treatments and included a cohort of genes that were cooperatively induced by both pathways. These included both novel and known components or modulators of TGF-beta and Wnt pathways, suggesting that mutual feedback is a feature of the coordinated activities of the ligands. The majority of the cooperative targets display increased expression in tumors derived from either Min (many intestinal neoplasia) or mouse mammary tumor virus (MMTV)-Wnt1 mice, two models of Wnt-induced tumors, with nine of these genes (Ankrd1, Ccnd1, Ctgf, Gpc1, Hs6st2, IL11, Inhba, Mmp14, and Robo1) showing increases in both. Reduction of TGF-beta signaling by expression of a dominant-negative TGF-beta type II receptor in bigenic MMTV-Wnt1/DNIIR mice increased mammary tumor latency and was correlated with a decrease in expression of Gpc1, Inhba, and Robo1, three of the TGF-beta/Wnt cooperative targets. Our results indicate that the TGF-beta and Wnt/beta-catenin pathways are firmly intertwined and generate a unique gene expression pattern that can contribute to tumor progression.

  6. Modular and Stochastic Approaches to Molecular Pathway Models of ATM, TGF beta, and WNT Signaling

    Science.gov (United States)

    Cucinotta, Francis A.; O'Neill, Peter; Ponomarev, Artem; Carra, Claudio; Whalen, Mary; Pluth, Janice M.

    2009-01-01

    Deterministic pathway models that describe the biochemical interactions of a group of related proteins, their complexes, activation through kinase, etc. are often the basis for many systems biology models. Low dose radiation effects present a unique set of challenges to these models including the importance of stochastic effects due to the nature of radiation tracks and small number of molecules activated, and the search for infrequent events that contribute to cancer risks. We have been studying models of the ATM, TGF -Smad and WNT signaling pathways with the goal of applying pathway models to the investigation of low dose radiation cancer risks. Modeling challenges include introduction of stochastic models of radiation tracks, their relationships to more than one substrate species that perturb pathways, and the identification of a representative set of enzymes that act on the dominant substrates. Because several pathways are activated concurrently by radiation the development of modular pathway approach is of interest.

  7. Altered Expression of Wnt Signaling Pathway Components in Osteogenesis of Mesenchymal Stem Cells in Osteoarthritis Patients.

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    Pilar Tornero-Esteban

    Full Text Available Osteoarthritis (OA is characterized by altered homeostasis of joint cartilage and bone, whose functional properties rely on chondrocytes and osteoblasts, belonging to mesenchymal stem cells (MSCs. WNT signaling acts as a hub integrating and crosstalking with other signaling pathways leading to the regulation of MSC functions. The aim of this study was to evaluate the existence of a differential signaling between Healthy and OA-MSCs during osteogenesis.MSCs of seven OA patients and six healthy controls were isolated, characterised and expanded. During in vitro osteogenesis, cells were recovered at days 1, 10 and 21. RNA and protein content was obtained. Expression of WNT pathway genes was evaluated using RT-qPCR. Functional studies were also performed to study the MSC osteogenic commitment and functional and post-traslational status of β-catenin and several receptor tyrosine kinases.Several genes were downregulated in OA-MSCs during osteogenesis in vitro. These included soluble Wnts, inhibitors, receptors, co-receptors, several kinases and transcription factors. Basal levels of β-catenin were higher in OA-MSCs, but calcium deposition and expression of osteogenic genes was similar between Healthy and OA-MSCs. Interestingly an increased phosphorylation of p44/42 MAPK (ERK1/2 signaling node was present in OA-MSCs.Our results point to the existence in OA-MSCs of alterations in expression of Wnt pathway components during in vitro osteogenesis that are partially compensated by post-translational mechanisms modulating the function of other pathways. We also point the relevance of other signaling pathways in OA pathophysiology suggesting their role in the maintenance of joint homeostasis through modulation of MSC osteogenic potential.

  8. Altered Expression of Wnt Signaling Pathway Components in Osteogenesis of Mesenchymal Stem Cells in Osteoarthritis Patients.

    Science.gov (United States)

    Tornero-Esteban, Pilar; Peralta-Sastre, Ascensión; Herranz, Eva; Rodríguez-Rodríguez, Luis; Mucientes, Arkaitz; Abásolo, Lydia; Marco, Fernando; Fernández-Gutiérrez, Benjamín; Lamas, José Ramón

    2015-01-01

    Osteoarthritis (OA) is characterized by altered homeostasis of joint cartilage and bone, whose functional properties rely on chondrocytes and osteoblasts, belonging to mesenchymal stem cells (MSCs). WNT signaling acts as a hub integrating and crosstalking with other signaling pathways leading to the regulation of MSC functions. The aim of this study was to evaluate the existence of a differential signaling between Healthy and OA-MSCs during osteogenesis. MSCs of seven OA patients and six healthy controls were isolated, characterised and expanded. During in vitro osteogenesis, cells were recovered at days 1, 10 and 21. RNA and protein content was obtained. Expression of WNT pathway genes was evaluated using RT-qPCR. Functional studies were also performed to study the MSC osteogenic commitment and functional and post-traslational status of β-catenin and several receptor tyrosine kinases. Several genes were downregulated in OA-MSCs during osteogenesis in vitro. These included soluble Wnts, inhibitors, receptors, co-receptors, several kinases and transcription factors. Basal levels of β-catenin were higher in OA-MSCs, but calcium deposition and expression of osteogenic genes was similar between Healthy and OA-MSCs. Interestingly an increased phosphorylation of p44/42 MAPK (ERK1/2) signaling node was present in OA-MSCs. Our results point to the existence in OA-MSCs of alterations in expression of Wnt pathway components during in vitro osteogenesis that are partially compensated by post-translational mechanisms modulating the function of other pathways. We also point the relevance of other signaling pathways in OA pathophysiology suggesting their role in the maintenance of joint homeostasis through modulation of MSC osteogenic potential.

  9. L-carnitine contributes to enhancement of neurogenesis from mesenchymal stem cells through Wnt/β-catenin and PKA pathway.

    Science.gov (United States)

    Fathi, Ezzatollah; Farahzadi, Raheleh; Charoudeh, Hojjatollah Nozad

    2017-03-01

    The identification of factors capable of enhancing neurogenesis has great potential for cellular therapies in neurodegenerative diseases. Multiple studies have shown the neuroprotective effects of L-carnitine (LC). This study determined whether neuronal differentiation of rat adipose tissue-derived mesenchymal stem cells (ADSCs) can be activated by LC. In this study, protein kinase A (PKA) and Wnt/β-catenin pathways were detected to show if this activation was due to these pathways. The expression of LC-induced neurogenesis markers in ADSCs was characterized using real-time PCR. ELISA was conducted to assess the expression of cyclic adenosine monophosphate (cAMP) and PKA. The expression of β-catenin, reduced dickkopf1 (DKK1), low-density lipoprotein receptor-related protein 5 (LRP5), Wnt1, and Wnt3a genes as Wnt/β-catenin signaling members were used to detect the Wnt/β-catenin pathway. It was observed that LC could promote neurogenesis in ADSCs as well as expression of some neurogenic markers. Moreover, LC causes to increase the cAMP levels and PKA activity. Treatment of ADSCs with H-89 (dihydrochloride hydrate) as PKA inhibitor significantly inhibited the promotion of neurogenic markers, indicating that the PKA signaling pathway could be involved in neurogenesis induction. Analyses of real-time PCR data showed that the mRNA expressions of β-catenin, DKK1, LRP5c-myc, Wnt1, and Wnt3a were increased in the presence of LC. Therefore, the present study showed that LC promotes ADSCs neurogenesis and the LC-induced neurogenic markers could be due to both the PKA and Wnt/β-catenin signaling pathway. Impact statement Neural tissue has long been believed as incapable of regeneration and the identification of cell types and factors capable of neuronal differentiation has generated intense interest. Mesenchymal stem cells (MSCs) are considered as potential targets for stem cell-based therapy. L-carnitin (LC) as an antioxidant may have neuroprotective effects in

  10. Effect of Wnt-1 inducible signaling pathway protein-2 (WISP-2/CCN5), a downstream protein of Wnt signaling, on adipocyte differentiation.

    Science.gov (United States)

    Inadera, Hidekuni; Shimomura, Akiko; Tachibana, Shinjiro

    2009-02-20

    Wnt signaling negatively regulates adipocyte differentiation, and ectopic expression of Wnt-1 in 3T3-L1 cells induces several downstream molecules of Wnt signaling, including Wnt-1 inducible signaling pathway protein (WISP)-2. In this study, we examined the role of WISP-2 in the process of adipocyte differentiation using an in vitro cell culture system. In the differentiation of 3T3-L1 cells, WISP-2 expression was observed in growing cells and declined thereafter. In the mitotic clonal expansion phase of adipocyte differentiation, WISP-2 expression was transiently down-regulated concurrently with up-regulation of CCAAT/enhancer-binding protein delta expression. Treatment of 3T3-L1 cells in the differentiation medium with lithium, an activator of Wnt signaling, inhibited the differentiation process with concomitant induction of WISP-2. Treatment of differentiated cells with lithium induced de-differentiation as evidenced by profound reduction of peroxisome proliferator-activator receptor gamma expression and concomitant induction of WISP-2. However, de-differentiation of differentiated cells induced by tumor necrosis factor-alpha did not induce WISP-2 expression. To directly examine the effect of WISP-2 on adipocyte differentiation, 3T3-L1 cells were infected with a retrovirus carrying WISP-2. Although forced expression of WISP-2 inhibited preadipocyte proliferation, it had no effect on adipocyte differentiation. Thus, although WISP-2 is a downstream protein of Wnt signaling, the role of WISP-2 on adipocyte differentiation may be marginal, at least in this in vitro culture model.

  11. Aberrant DNA methylation of WNT pathway genes in the development and progression of CIMP-negative colorectal cancer.

    Science.gov (United States)

    Galamb, Orsolya; Kalmár, Alexandra; Péterfia, Bálint; Csabai, István; Bodor, András; Ribli, Dezső; Krenács, Tibor; Patai, Árpád V; Wichmann, Barnabás; Barták, Barbara Kinga; Tóth, Kinga; Valcz, Gábor; Spisák, Sándor; Tulassay, Zsolt; Molnár, Béla

    2016-08-02

    The WNT signaling pathway has an essential role in colorectal carcinogenesis and progression, which involves a cascade of genetic and epigenetic changes. We aimed to analyze DNA methylation affecting the WNT pathway genes in colorectal carcinogenesis in promoter and gene body regions using whole methylome analysis in 9 colorectal cancer, 15 adenoma, and 6 normal tumor adjacent tissue (NAT) samples by methyl capture sequencing. Functional methylation was confirmed on 5-aza-2'-deoxycytidine-treated colorectal cancer cell line datasets. In parallel with the DNA methylation analysis, mutations of WNT pathway genes (APC, β-catenin/CTNNB1) were analyzed by 454 sequencing on GS Junior platform. Most differentially methylated CpG sites were localized in gene body regions (95% of WNT pathway genes). In the promoter regions, 33 of the 160 analyzed WNT pathway genes were differentially methylated in colorectal cancer vs. normal, including hypermethylated AXIN2, CHP1, PRICKLE1, SFRP1, SFRP2, SOX17, and hypomethylated CACYBP, CTNNB1, MYC; 44 genes in adenoma vs. NAT; and 41 genes in colorectal cancer vs. adenoma comparisons. Hypermethylation of AXIN2, DKK1, VANGL1, and WNT5A gene promoters was higher, while those of SOX17, PRICKLE1, DAAM2, and MYC was lower in colon carcinoma compared to adenoma. Inverse correlation between expression and methylation was confirmed in 23 genes, including APC, CHP1, PRICKLE1, PSEN1, and SFRP1. Differential methylation affected both canonical and noncanonical WNT pathway genes in colorectal normal-adenoma-carcinoma sequence. Aberrant DNA methylation appears already in adenomas as an early event of colorectal carcinogenesis.

  12. WNT signalling and haematopoiesis: a WNT-WNT situation.

    NARCIS (Netherlands)

    Staal, F.J.T.; Clevers, J.C.

    2005-01-01

    The evolutionarily conserved WNT-signalling pathway has pivotal roles during the development of many organ systems, and dysregulated WNT signalling is a key factor in the initiation of various tumours. Recent studies have implicated a role for WNT signal transduction at several stages of lymphocyte

  13. Apical constriction and invagination downstream of the canonical Wnt signaling pathway require Rho1 and Myosin II.

    Science.gov (United States)

    Zimmerman, Sandra G; Thorpe, Lauren M; Medrano, Vilma R; Mallozzi, Carolyn A; McCartney, Brooke M

    2010-04-01

    The tumor suppressor Adenomatous polyposis coli (APC) is a negative regulator of Wnt signaling and functions in cytoskeletal organization. Disruption of human APC in colonic epithelia initiates benign polyps that progress to carcinoma following additional mutations. The early events of polyposis are poorly understood, as is the role of canonical Wnt signaling in normal epithelial architecture and morphogenesis. To determine the consequences of complete loss of APC in a model epithelium, we generated APC2 APC1 double null clones in the Drosophila wing imaginal disc. APC loss leads to segregation, apical constriction, and invagination that result from transcriptional activation of canonical Wnt signaling. Further, we show that Wnt-dependent changes in cell fate can be decoupled from Wnt-dependent changes in cell shape. Wnt activation is reported to upregulate DE-cadherin in wing discs, and elevated DE-cadherin is thought to promote apical constriction. We find that apical constriction and invagination of APC null tissue are independent of DE-cadherin elevation, but are dependent on Myosin II activity. Further, we show that disruption of Rho1 suppresses apical constriction and invagination in APC null cells. Our data suggest a novel link between canonical Wnt signaling and epithelial structure that requires activation of the Rho1 pathway and Myosin II. Copyright 2010 Elsevier Inc. All rights reserved.

  14. Apical constriction and invagination downstream of the canonical Wnt signaling pathway requires Rho1 and Myosin II

    Science.gov (United States)

    Zimmerman, Sandra G.; Thorpe, Lauren M.; Medrano, Vilma R.; Mallozzi, Carolyn A.; McCartney, Brooke M.

    2010-01-01

    The tumor suppressor Adenomatous polyposis coli (APC) is a negative regulator of Wnt signaling and functions in cytoskeletal organization. Disruption of human APC in colonic epithelia initiates benign polyps that progress to carcinoma following additional mutations. The early events of polyposis are poorly understood, as is the role of canonical Wnt signaling in normal epithelial architecture and morphogenesis. To determine the consequences of complete loss of APC in a model epithelium, we generated APC2 APC1 double null clones in the Drosophila wing imaginal disc. APC loss leads to segregation, apical constriction, and invagination that result from transcriptional activation of canonical Wnt signaling. Further, we show that Wnt-dependent changes in cell fate can be decoupled from Wnt-dependent changes in cell shape. Wnt activation is reported to upregulate DE-cadherin in wing discs, and elevated DE-cadherin is thought to promote apical constriction. We find that apical constriction and invagination of APC null tissue are independent of DE-cadherin elevation, but are dependent on Myosin II activity. Further, we show that disruption of Rho1 suppresses apical constriction and invagination in APC null cells. Our data suggest a novel link between canonical Wnt signaling and epithelial structure that requires activation of the Rho1 pathway and Myosin II. PMID:20102708

  15. Interaction between LRP5 and Frat1 mediates the activation of the Wnt canonical pathway.

    Science.gov (United States)

    Hay, Eric; Faucheu, Chi; Suc-Royer, Isabelle; Touitou, Robert; Stiot, Veronique; Vayssière, Béatrice; Baron, Roland; Roman-Roman, Sergio; Rawadi, Georges

    2005-04-08

    Low density lipoprotein receptor-related protein 5 (LRP5) has been identified as a Wnt co-receptor involved in the activation of the beta-catenin signaling pathway. To improve our understanding of the molecular mechanisms by which LRP5 triggers the canonical Wnt signaling cascade, we have screened for potential partners of LRP5 using the yeast two-hybrid system and identified Frat1 as a protein interacting with the cytoplasmic domain of LRP5. We demonstrate here that LRP5/Frat1 interaction is involved in beta-catenin nuclear translocation and TCF-1 transcriptional activation. The addition of Wnt3a or overexpression of constitutively active truncated LRP5 (LRP5C) induces Frat1 recruitment to the cell membrane. Overexpression of a dominant negative form of disheveled (Dvl) shows that this protein positively affects LRP5/Frat1 interaction. Furthermore, the fact that dominant negative Dvl does not interfere with LRP5C/Frat1 interaction can explain how LRP5C is capable of acting independently of this major Wnt signaling player. Axin, which has been shown to interact with LRP5 and to be recruited to the membrane through this interaction, was found to co-immunoprecipitate with Frat1 and LRP5. We propose that recruitment of Axin and Frat1 to the membrane by LRP5 leads to both Axin degradation and Frat1-mediated inhibition of glycogen synthase kinase-3. As a consequence, beta-catenin is no longer bound to Axin or phosphorylated by glycogen synthase kinase-3, resulting in TCF-1 activation.

  16. EZH2 Impairs Human Dental Pulp Cell Mineralization via the Wnt/β-Catenin Pathway.

    Science.gov (United States)

    Li, B; Yu, F; Wu, F; Hui, T; A, P; Liao, X; Yin, B; Wang, C; Ye, L

    2017-12-01

    The enhancer of zeste homolog 2 (EZH2) is a catalytic subunit of PRC2 (polycomb repressor complex 2). It mediates gene silencing via methyltransferase activity and is involved in the determination of cell lineage. However, the function of EZH2 and the underlying mechanisms by which it affects the differentiation of human dental pulp cell (hDPC) have remained underexplored. In this research, we found that EZH2 expression decreased during the mineralization of hDPCs, with attenuated H3K27me3 (trimethylation on lysine 27 in histone H3). Overexpression of EZH2 impaired the odontogenic differentiation of hDPCs, while EZH2 without methyltransferase activity mutation (mutation of suppressed variegation of 3 to 9, enhancer of zeste and trithorax domain, EZH2ΔSET) did not display this phenotype. In addition, siRNA knockdown studies showed that EZH2 negatively modulated hDPC differentiation in vitro and inhibited mineralized nodule formation in transplanted β-tricalcium phosphate / hDPC composites. To further investigate the underlying mechanisms, we explored the Wnt/β-catenin signaling pathway in view of the fact that previous research had documented the essential role that it plays during hDPC mineralization, as well as its links to EZH2 in other cells. We demonstrated for the first time that EZH2 depletion activated the Wnt/β-catenin signaling pathway and enhanced the accumulation of β-catenin in hDPCs. Chromatin immunoprecipitation analysis suggested that these effects are attributable to the level of the EZH2-regulated H3K27me3 on the β-catenin promoter. We conclude that EZH2 plays a negative role during the odontogenic differentiation of hDPCs. Suppression of EZH2 could promote hDPC mineralization by epigenetically regulating the expression of β-catenin and activating the Wnt canonical signaling pathway.

  17. Melatonin attenuates titanium particle-induced osteolysis via activation of Wnt/β-catenin signaling pathway.

    Science.gov (United States)

    Ping, Zichuan; Hu, Xuanyang; Wang, Liangliang; Shi, Jiawei; Tao, Yunxia; Wu, Xiexing; Hou, Zhenyang; Guo, Xiaobin; Zhang, Wen; Yang, Huilin; Xu, Yaozeng; Wang, Zhirong; Geng, Dechun

    2017-03-15

    Wear debris-induced inhibition of bone regeneration and extensive bone resorption were common features in peri-prosthetic osteolysis (PPO). Here, we investigated the effect of melatonin on titanium particle-stimulated osteolysis in a murine calvariae model and mouse-mesenchymal-stem cells (mMSCs) culture system. Melatonin inhibited titanium particle-induced osteolysis and increased bone formation at osteolytic sites, confirmed by radiological and histomorphometric data. Furthermore, osteoclast numbers decreased dramatically in the low- and high-melatonin administration mice, as respectively, compared with the untreated animals. Melatonin alleviated titanium particle-induced depression of osteoblastic differentiation and mineralization in mMSCs. Mechanistically, melatonin was found to reduce the degradation of β-catenin, levels of which were decreased in presence of titanium particles both in vivo and in vitro. To further ensure whether the protective effect of melatonin was mediated by the Wnt/β-catenin signaling pathway, ICG-001, a selective β-catenin inhibitor, was added to the melatonin-treated groups and was found to attenuate the effect of melatonin on mMSC mineralization. We also demonstrated that melatonin modulated the balance between receptor activator of nuclear factor kappa-B ligand and osteoprotegerin via activation of Wnt/β-catenin signaling pathway. These findings strongly suggest that melatonin represents a promising candidate in the treatment of PPO. Peri-prosthetic osteolysis, initiated by wear debris-induced inhibition of bone regeneration and extensive bone resorption, is the leading cause for implant failure and reason for revision surgery. In the current study, we demonstrated for the first time that melatonin can induce bone regeneration and reduce bone resorption at osteolytic sites caused by titanium-particle stimulation. These effects might be mediated by activating Wnt/β-catenin signaling pathway and enhancing osteogenic

  18. PATHWAYS TO SUSTAINABLE BANKING MANAGEMENT

    Directory of Open Access Journals (Sweden)

    Dragan (Santamarian Oana Raluca

    2012-12-01

    Full Text Available This paper describes one of the major challenges of the future: the sustainable development of the society. Sustainability is now increasingly recognized as central to the growth of emerging market economies. For the banking sector, this represents both a demand for greater social and environmental responsibility as well as a new landscape of business opportunity. Several years ago, the main part of the banks did not consider the social and environmental problems relevant for their operations. Recently, the banks began to realize the major impact of the sustainable development over the way of ulterior development of the society and, implicitly over the way of creating of the banking value in the future. In this context, the development of a banking management system, based on sustainable principles represents one of the provocations of these days.Starting from literature in the sustainable banking management field in this paper are presented several relevant issues related to risk management in the context of sustainable banking financing: the need to implement the sustainable management principles in financial and banking industry; the role of banks in sustainable development of society; social and environmental risk management policies, events that have shaped the role of the banking sector in sustainable development; international standards regarding sustainable banking management such us: Equator Principles for sustainable investment projects’ financing or GRI principles for sustainable reporting. Furthermore, we developed a practical case study related to the implementation of sustainable banking management at Bank of America.

  19. Mathematical and Statistical Techniques for Systems Medicine: The Wnt Signaling Pathway as a Case Study

    KAUST Repository

    MacLean, Adam L.

    2015-12-16

    The last decade has seen an explosion in models that describe phenomena in systems medicine. Such models are especially useful for studying signaling pathways, such as the Wnt pathway. In this chapter we use the Wnt pathway to showcase current mathematical and statistical techniques that enable modelers to gain insight into (models of) gene regulation and generate testable predictions. We introduce a range of modeling frameworks, but focus on ordinary differential equation (ODE) models since they remain the most widely used approach in systems biology and medicine and continue to offer great potential. We present methods for the analysis of a single model, comprising applications of standard dynamical systems approaches such as nondimensionalization, steady state, asymptotic and sensitivity analysis, and more recent statistical and algebraic approaches to compare models with data. We present parameter estimation and model comparison techniques, focusing on Bayesian analysis and coplanarity via algebraic geometry. Our intention is that this (non-exhaustive) review may serve as a useful starting point for the analysis of models in systems medicine.

  20. Tyrosine-based signal mediates LRP6 receptor endocytosis and desensitization of Wnt/β-catenin pathway signaling.

    Science.gov (United States)

    Liu, Chia-Chen; Kanekiyo, Takahisa; Roth, Barbara; Bu, Guojun

    2014-10-03

    Wnt/β-catenin signaling orchestrates a number of critical events including cell growth, differentiation, and cell survival during development. Misregulation of this pathway leads to various human diseases, specifically cancers. Endocytosis and phosphorylation of the LDL receptor-related protein 6 (LRP6), an essential co-receptor for Wnt/β-catenin signaling, play a vital role in mediating Wnt/β-catenin signal transduction. However, its regulatory mechanism is not fully understood. In this study, we define the mechanisms by which LRP6 endocytic trafficking regulates Wnt/β-catenin signaling activation. We show that LRP6 mutant with defective tyrosine-based signal in its cytoplasmic tail has an increased cell surface distribution and decreased endocytosis rate. These changes in LRP6 endocytosis coincide with an increased distribution to caveolae, increased phosphorylation, and enhanced Wnt/β-catenin signaling. We further demonstrate that treatment of Wnt3a ligands or blocking the clathrin-mediated endocytosis of LRP6 leads to a redistribution of wild-type receptor to lipid rafts. The LRP6 tyrosine mutant also exhibited an increase in signaling activation in response to Wnt3a stimulation when compared with wild-type LRP6, and this activation is suppressed when caveolae-mediated endocytosis is blocked. Our results reveal molecular mechanisms by which LRP6 endocytosis routes regulate its phosphorylation and the strength of Wnt/β-catenin signaling, and have implications on how this pathway can be modulated in human diseases. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  1. Fibulin-4 is a novel Wnt/β-Catenin pathway activator in human osteosarcoma

    Energy Technology Data Exchange (ETDEWEB)

    Li, Renzeng [Department of Othopedics, The First Affiliated Hospital of Zhengzhou University, No.1 Jianshe Road, Zhengzhou, 450000 Henan (China); Department of Orthopaedics, The No.3 People’s Hospital of Anyang City, Anyang 455000 (China); Wang, Limin, E-mail: gu2keo@163.com [Department of Othopedics, The First Affiliated Hospital of Zhengzhou University, No.1 Jianshe Road, Zhengzhou, 450000 Henan (China)

    2016-06-10

    Fibulin-4, an extracellular glycoprotein implicated in connective tissue development and elastic fiber formation, draws increasing focuses in cancer research. However, little is known about the underlying oncogenic roles of Fibulin-4 in human osteosarcoma (OS). In this study, by immunohistochemical analysis, upregulated expression of Fibulin-4 was found in the OS clinical specimens and cell lines compared to their normal counterparts. Fibulin-4 was positively correlated with the T stage of OS patients, and the proliferation index Ki67. Based on informatics analysis and functional verification, microRNA-137 was identified as a potential upstream regulator of Fibulin-4. Knockdown of Fibulin-4 or introduction of microRNA-137 inhibited cell proliferation and promoted cell apoptosis, and adverse effects were observed by overexpression of Fibulin-4. Furthermore, the tumor-suppressive functions of microRNA-137 were markedly abolished by restoration of Fibulin-4 expression in OS cells. Mechanistically, Fibulin-4 activated Wnt/β-Catenin pathway and promoted the expression of its downstream targets, including CCND2, c-Myc and VEGF. Taken together, Fibulin-4 plays critical neoplastic roles in tumor growth of human OS by activating Wnt/β-Catenin signaling and may represent a potential therapeutic target. -- Highlights: •Upregulated Fibulin-4 correlates tumor growth in human OS. •MicroRNA-137 is a critical regulator of Fibulin-4 expression. •Deregulated miR-137/Fibulin-4 axis promotes tumor growth of human OS. •Wnt/β-Catenin pathway is activated by Fibulin-4 stimulation.

  2. [Canonical Wnt signaling pathway of the osteogenic differentiation of human periodontal ligament stem cells induced by advanced glycation end products].

    Science.gov (United States)

    Yan, Wu; Chao, Deng; Kun, Yang; Xiaoxia, Cui; Qi, Liu; Yan, Jin

    2015-12-01

    The effect of advanced glycation end products (AGEs) on the osteogenic differentiation of humanperiodontal ligament stem cells(hPDLSCs) was discussed. Changes in the Wnt signaling pathway during glycation were also determined. In vitro tissue explanting method was primarily applied. Limiting diluted clone was cultured to obtain hPDLSCs in vitro. The subjects were divided into two groups: the healthy group (N-hPDLSCs) and the AGEs-stimulating group (A-hPDLSCs). Osteoblast mineralization was induced in the experimental groups. The following processes were performed: alizarin red staining; alkaline phosphatase (ALP) staining; real time polymerase chain reaction (real time PCR) for detecting osteogenic genes and Wnt classical pathway-related factors, DKK-1 and β-catenin; Western blot analysis. Bone protein and β-catenin were correlated in the nuclear expression. The cells were osteogenically induced. ALP staining showed that the N-hPDLSCs displayed the deepest color. Alizarin red staining indicated that the A-hPDLSCs group had less calcified nodules than the N-hPDLSCs group. The real time PCR results suggested that the expression of relative osteogenic genes in A-hPDLSCs was quite low. Statistically significant differences in differentiation were found between groups (P < 0.05). The Western blot result was similar to that of real time PCR. Classical Wnt signaling pathway-related factor β-catenin was higher in A-hPDLSCs than in N-hPDLSCs. By contrast, DKK-1, which is an inhibitor in the Wnt pathway, had a significantly lower expression rate in A-hPDLSCs than in N-hPDLSCs. The Western blot result also showed that β-catenin expression in the nucleoprotein in A-hPDLSCs was notably higher than in N-hPDLSCs. AGEs can inhibit hPDLSCs osteogenic differentiation. AGEs induce changes in the normal periodontal ligament stem cells classical Wnt pathway. Canonical Wnt pathway is reactivated because of AGEs stimulation.

  3. β-Arrestin interacts with the beta/gamma subunits of trimeric G-proteins and dishevelled in the Wnt/Ca(2+ pathway in xenopus gastrulation.

    Directory of Open Access Journals (Sweden)

    Katharina Seitz

    Full Text Available β-Catenin independent, non-canonical Wnt signaling pathways play a major role in the regulation of morphogenetic movements in vertebrates. The term non-canonical Wnt signaling comprises multiple, intracellularly divergent, Wnt-activated and β-Catenin independent signaling cascades including the Wnt/Planar Cell Polarity and the Wnt/Ca(2+ cascades. Wnt/Planar Cell Polarity and Wnt/Ca(2+ pathways share common effector proteins, including the Wnt ligand, Frizzled receptors and Dishevelled, with each other and with additional branches of Wnt signaling. Along with the aforementioned proteins, β-Arrestin has been identified as an essential effector protein in the Wnt/β-Catenin and the Wnt/Planar Cell Polarity pathway. Our results demonstrate that β-Arrestin is required in the Wnt/Ca(2+ signaling cascade upstream of Protein Kinase C (PKC and Ca(2+/Calmodulin-dependent Protein Kinase II (CamKII. We have further characterized the role of β-Arrestin in this branch of non-canonical Wnt signaling by knock-down and rescue experiments in Xenopus embryo explants and analyzed protein-protein interactions in 293T cells. Functional interaction of β-Arrestin, the β subunit of trimeric G-proteins and Dishevelled is required to induce PKC activation and membrane translocation. In Xenopus gastrulation, β-Arrestin function in Wnt/Ca(2+ signaling is essential for convergent extension movements. We further show that β-Arrestin physically interacts with the β subunit of trimeric G-proteins and Dishevelled, and that the interaction between β-Arrestin and Dishevelled is promoted by the beta/gamma subunits of trimeric G-proteins, indicating the formation of a multiprotein signaling complex.

  4. Altered Wnt Signaling Pathway in Cognitive Impairment Caused by Chronic Intermittent Hypoxia: Focus on Glycogen Synthase Kinase-3β and β-catenin

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    Yue-Ying Pan

    2016-01-01

    Conclusions: Wnt/β-catenin signaling pathway abnormalities possibly play an important role in the development of cognitive deficits among mice exposed to CIH and that LiCl might attenuate CIH-induced cognitive impairment via Wnt/β-catenin signaling pathway.

  5. Common genetic variants in Wnt signaling pathway genes as potential prognostic biomarkers for colorectal cancer.

    Directory of Open Access Journals (Sweden)

    Wen-Chien Ting

    Full Text Available Compelling evidence has implicated the Wnt signaling pathway in the pathogenesis of colorectal cancer. We assessed the use of tag single nucleotide polymorphisms (tSNPs in adenomatous polyposis coli (APC/β-catenin (CTNNB1 genes to predict outcomes in patients with colorectal cancer. We selected and genotyped 10 tSNP to predict common variants across entire APC and CTNNB1 genes in 282 colorectal cancer patients. The associations of these tSNPs with distant metastasis-free survival and overall survival were evaluated by Kaplan-Meier analysis, Cox regression model, and survival tree analysis. The 5-year overall survival rate was 68.3%. Survival tree analysis identified a higher-order genetic interaction profile consisting of the APC rs565453, CTNNB1 2293303, and APC rs1816769 that was significantly associated with overall survival. The 5-year survival overall rates were 89.2%, 66.1%, and 58.8% for the low-, medium-, and high-risk genetic profiles, respectively (log-rank P = 0.001. After adjusting for possible confounders, including age, gender, carcinoembryonic antigen levels, tumor differentiation, stage, lymphovascular invasion, perineural invasion, and lymph node involvement, the genetic interaction profile remained significant. None of the studied SNPs were individually associated with distant metastasis-free survival and overall survival. Our results suggest that the genetic interaction profile among Wnt pathway SNPs might potentially increase the prognostic value in outcome prediction for colorectal cancer.

  6. Cytotoxicity and activation of the Wnt/beta-catenin pathway in mouse embryonic stem cells treated with four GSK3 inhibitors.

    Science.gov (United States)

    Naujok, Ortwin; Lentes, Jana; Diekmann, Ulf; Davenport, Claudia; Lenzen, Sigurd

    2014-04-29

    Small membrane-permeable molecules are now widely used during maintenance and differentiation of embryonic stem cells of different species. In particular the glycogen synthase kinase 3 (GSK3) is an interesting target, since its chemical inhibition activates the Wnt/beta-catenin pathway. In the present comparative study four GSK3 inhibitors were characterized. Cytotoxicity and potential to activate the Wnt/beta-catenin pathway were tested using the commonly used GSK3 inhibitors BIO, SB-216763, CHIR-99021, and CHIR-98014. Wnt/beta-catenin-dependent target genes were measured by quantitative PCR to confirm the Wnt-reporter assay and finally EC50-values were calculated. CHIR-99021 and SB-216763 had the lowest toxicities in mouse embryonic stem cells and CHIR-98014 and BIO the highest toxicities. Only CHIR-99021 and CHIR-98014 lead to a strong induction of the Wnt/beta-catenin pathway, whereas BIO and SB-216763 showed a minor or no increase in activation of the Wnt/beta-catenin pathway over the natural ligand Wnt3a. The data from the Wnt-reporter assay were confirmed by gene expression analysis of the TCF/LEF regulated gene T. Out of the four tested GSK3 inhibitors, only CHIR-99021 and CHIR-98014 proved to be potent pharmacological activators of the Wnt/beta-catenin signaling pathway. But only in the case of CHIR-99021 high potency was combined with very low toxicity.

  7. Canonical and noncanonical Wnt pathways: a comparison between endometrial cancer type I and atrophic endometrium in Brazil

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    Marina de Pádua Nogueira Menezes

    Full Text Available CONTEXT AND OBJECTIVE: The Wnt pathway is involved in tumorigenesis of several tissues. For this reason, we proposed to evaluate Wnt gene expression in endometrial cancer type I. DESIGN AND SETTING: Cross-sectional study on materials gathered from the tissue bank of the Department of Pathology, Universidade Federal de São Paulo. METHODS: Endometrial specimens were obtained from surgeries performed between 1995 and 2005 at São Paulo Hospital, Universidade Federal de São Paulo. The material was divided into two groups according to tissue type: Group A, atrophic endometrium (n = 15; and Group B, endometrial adenocarcinoma (n = 45. We compared the immunohistochemical expression of Wnt1, Frizzled-1 (FZD1, Wnt5a, Frizzled-5 (FZD5 and beta-catenin between endometrial cancer type I and atrophic endometrium. RESULTS: Regarding Wnt1, FZD1 and Wnt5a expression, no significant association was observed between the groups. A significant association was observed between the groups in relation to FZD5 expression (P = 0.001. The proportion of FZD5-positive samples was significantly higher in group A (80.0% than in group B (31.1%. Regarding the survival curve for FZD5 in group B, we did not find any significant association between atrophic endometrium and endometrial adenocarcinoma. We also did not find any significant association regarding beta-catenin expression (P = 1.000. CONCLUSION: FZD5 is downregulated in endometrial adenocarcinoma, in comparison with atrophic endometrium

  8. Location-specific effect of microbiota and MyD88-dependent signaling on Wnt/β-catenin pathway and intestinal stem cells.

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    Moossavi, Shirin

    2014-01-01

    Intestinal homeostasis depends on the proper activity of the intestinal stem cells (ISCs) and an appropriate host response to the normal resident microbiota. The question on the effect of microbiota on ISCs behavior has not been addressed yet. Canonical Wnt pathway and ISC gene expression signature was compared in germfree vs. conventional and MyD88(-/-) vs. Myd88(+/+) mice based on publicly available gene expression data sets. Microbiota and MyD88-dependent signaling have distinct effects on the Wnt pathway and ISC at gene expression level. In addition, the effect of microbiota and MyD88-dependent signaling on Wnt pathway and ISCs show regional variation. The net effect of microbiota on Wnt pathway and ISCs cannot be inferred from the available data. Nonetheless, the data are suggestive of a potential regulatory mechanism of the Wnt pathway by the microbiota and plausibly by any alteration in the microbiota composition.

  9. Epstein-Barr virus associated modulation of Wnt pathway is not dependent on latent membrane protein-1.

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    Natasha Webb

    2008-09-01

    Full Text Available Previous studies have indicated that Epstein-Barr virus (EBV can modulate the Wnt pathway in virus-infected cells and this effect is mediated by EBV-encoded oncogene latent membrane protein 1 (LMP1. Here we have reassessed the role of LMP1 in regulating the expression of various mediators of the canonical Wnt cascade. Contradicting the previous finding, we found that the levels of E-cadherin, beta-catenin, Glycogen Synthase Kinase 3ss (GSK3beta, axin and alpha-catenin were not affected by the expression of LMP1 sequences from normal B cells or nasopharyngeal carcinoma. Moreover, we also show that LMP1 expression had no detectable effect on the E-cadherin and beta-catenin interaction and did not induce transcriptional activation of beta-catenin. Taken together these studies demonstrate that EBV-mediated activation of Wnt pathway is not dependent on the expression of LMP1.

  10. H19 mediates methotrexate resistance in colorectal cancer through activating Wnt/β-catenin pathway

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    Wu, Ke-feng [Guangdong Key Laboratory for Research and Development of Natural Drugs, Guangdong Medical University, Zhanjiang, Guangdong (China); Liang, Wei-Cheng [School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong (China); Feng, Lu [Department of Orthopaedics & Traumatology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong (China); Pang, Jian-xin [School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515 (China); Waye, Mary Miu-Yee [School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong (China); Zhang, Jin-Fang [Department of Orthopaedics & Traumatology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong (China); Fu, Wei-Ming, E-mail: fuweiming76@smu.edu.cn [School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515 (China)

    2017-01-15

    Colorectal cancer (CRC) is a common malignancy, most of which remain unresponsive to chemotherapy. As one of the earliest cytotoxic drugs, methotrexate (MTX) serves as an anti-metabolite and anti-folate chemotherapy for various cancers. Unfortunately, MTX resistance prevents its clinical application in cancer therapy. Thereby, overcoming the drug resistance is an alternative strategy to maximize the therapeutic efficacy of MTX in clinics. Long noncoding RNAs (lncRNAs) have gained widespread attention in recent years. More and more emerging evidences have demonstrated that they play important regulatory roles in various biological activities and disease progression including drug resistance. In the present study, a MTX-resistant colorectal cell line HT-29 (HT-29-R) was developed, which displayed the active proliferation and shortened cell cycle. LncRNA H19 was found to be significantly upregulated in this resistant cell line. Further investigation showed that H19 knockdown sensitized the MTX resistance in HT-29-R cells while its overexpression improved the MTX resistance in the parental cells, suggesting that H19 mediate MTX resistance. The Wnt/β-catenin signaling was activated in HT-29-R cells, and H19 knockdown suppressed this signaling in the parental cells. In conclusion, H19 mediated MTX resistance via activating Wnt/β-catenin signaling, which help to develop H19 as a promising therapeutic target for MTX resistant CRC. - Highlights: • A methotrexate (MTX) -resistant colorectal cancer cell line HT-29 (HT-29-R) has been developed. • H19 was upregulated in HT-29-R cells. • H19 mediated MTX resistance in colorectal cancer (CRC). • Wnt/β-catenin pathway was involved in the H19-mediated MTX resistance in CRC cells.

  11. Gene expression analysis of canonical Wnt pathway transcriptional regulators during early morphogenesis of the facial region in the mouse embryo.

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    Vendrell, Victor; Summerhurst, Kristen; Sharpe, James; Davidson, Duncan; Murphy, Paula

    2009-06-01

    Structures and features of the face, throat and neck are formed from a series of branchial arches that grow out along the ventrolateral aspect of the embryonic head. Multiple signalling pathways have been implicated in patterning interactions that lead to species-specific growth and differentiation within the branchial region that sculpt these features. A direct role for Wnt signalling in particular has been shown. The spatial and temporal distribution of Wnt pathway components contributes to the operation of the signalling system. We present the precise distribution of gene expression of canonical Wnt pathway transcriptional regulators, Tcf1, Lef1, Tcf3, Tcf4 and beta-catenin between embryonic day (E) 9.5 and 11.5. In situ hybridization combined with Optical Projection Tomography was used to record and compare distribution of transcripts in 3D within the developing branchial arches. This shows widespread yet very specific expression of the gene set indicating that all genes contribute to proper patterning of the region. Tcf1 and Lef1 are more prominent in rostral arches, particularly at later ages, and Tcf3 and Tcf4 are in general expressed more deeply (medial/endodermal aspect) in the arches than Tcf1 and Lef1. Comparison with Wnt canonical pathway readout patterns shows that the relationship between the expression of individual transcription factors and activation of the pathway is not simple, indicating complexity and flexibility in the signalling system.

  12. Effects of hepatitis C virus core protein and nonstructural protein 4B on the Wnt/β-catenin pathway.

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    Jiang, Xiao-Hua; Xie, Yu-Tao; Cai, Ya-Ping; Ren, Jing; Ma, Tao

    2017-05-25

    Hepatitis C virus (HCV) core protein and nonstructural protein 4B (NS4B) are potentially oncogenic. Aberrant activation of the Wnt/β-catenin signaling pathway is closely associated with hepatocarcinogenesis. We investigated the effects of HCV type 1b core protein and NS4B on Wnt/β-catenin signaling in various liver cells, and explored the molecular mechanism underlying HCV-related hepatocarcinogenesis. Compared with the empty vector control, HCV core protein and NS4B demonstrated the following characteristics in the Huh7 cells: significantly enhanced β-catenin/Tcf-dependent transcriptional activity (F = 40.87, P  0.05), but they did significantly enhance Wnt3a-induced β-catenin/Tcf-dependent transcriptional activity (F = 64.25, P core protein than with NS4B (P core protein and NS4B directly activate the Wnt/β-catenin signaling pathway in Huh7 cells and LO2 cells induced by Wnt3a. These data suggest that HCV core protein and NS4B contribute to HCV-associated hepatocellular carcinogenesis.

  13. Undariopsis peterseniana Promotes Hair Growth by the Activation of Wnt/β-Catenin and ERK Pathways

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    Jung-Il Kang

    2017-05-01

    Full Text Available In this study, we investigated the effect and mechanism of Undariopsis peterseniana, an edible brown alga, on hair growth. The treatment of vibrissa follicles with U. peterseniana extract ex vivo for 21 days significantly increased the hair-fiber lengths. The U. peterseniana extract also significantly accelerated anagen initiation in vivo. Moreover, we found that U. peterseniana extract was able to open the KATP channel, which may contribute to increased hair growth. The U. peterseniana extract decreased 5α-reductase activity and markedly increased the proliferation of dermal papilla cells, a central regulator of the hair cycle. The U. peterseniana extract increased the levels of cell cycle proteins, such as Cyclin D1, phospho(ser780-pRB, Cyclin E, phospho-CDK2, and CDK2. The U. peterseniana extract also increased the phosphorylation of ERK and the levels of Wnt/β-catenin signaling proteins such as glycogen synthase kinase-3β (GSK-3β and β-catenin. These results suggested that the U. peterseniana extract had the potential to influence hair growth by dermal papilla cells proliferation through the activation of the Wnt/β-catenin and ERK pathways. We isolated a principal of the U. peterseniana extract, which was subsequently identified as apo-9′-fucoxanthinone, a trichogenic compound. The results suggested that U. peterseniana extract may have a pivotal role in the treatment of alopecia.

  14. NHERF1/EBP50 Suppresses Wnt-β-Catenin Pathway-Driven Intestinal Neoplasia.

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    Georgescu, Maria-Magdalena; Gagea, Mihai; Cote, Gilbert

    2016-08-01

    NHERF1/EBP50, an adaptor molecule that interacts with β-catenin, YAP, and PTEN, has been recently implicated in the progression of various human malignancies, including colorectal cancer. We report here that NHERF1 acts as a tumor suppressor in vivo for intestinal adenoma development. NHERF1 is highly expressed at the apical membrane of mucosa intestinal epithelial cells (IECs) and serosa mesothelial cells. NHERF1-deficient mice show overall longer small intestine and colon that most likely could be attributed to a combination of defects, including altered apical brush border of absorbtive IECs and increased number of secretory IECs. NHERF1 deficiency in Apc(Min/+) mice resulted in significantly shorter animal survival due to markedly increased tumor burden. This resulted from a moderate increase of the overall tumor density, more pronounced in females than males, and a massive increase in the number of large adenomas in both genders. The analysis of possible pathways controlling tumor size showed upregulation of Wnt-β-catenin pathway, higher expression of unphosphorylated YAP, and prominent nuclear expression of cyclin D1 in NHERF1-deficient tumors. Similar YAP changes, with relative decrease of phosphorylated YAP and increase of nuclear YAP expression, were observed as early as the adenoma stages in the progression of human colorectal cancer. This study discusses a complex role of NHERF1 for intestinal morphology and presents indisputable evidence for its in vivo tumor suppressor function upstream of Wnt-β-catenin and Hippo-YAP pathways. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

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

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

    2015-01-01

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

  16. Modulation of key elements of the Wnt pathway by apple polyphenols.

    Science.gov (United States)

    Kern, Melanie; Pahlke, Gudrun; Ngiewih, Yufanyi; Marko, Doris

    2006-09-20

    Glycogen synthase kinase-3beta (GSK3beta) is one of the key elements of the Wnt pathway involved in the regulation of beta-catenin homeostasis. The inhibition of GSK3beta kinase activity might lead to the onset of beta-catenin/TCF/LEF-mediated gene transcription, representing a potentially mitogenic stimulus. Apple polyphenols have been shown to mediate several biological effects that might be of interest with respect to chemoprevention. The objective of the study was to elucidate whether apple polyphenols also modulate key elements of the Wnt pathway, an effect that might limit the usefulness of these compounds for the prevention of carcinogenesis. A polyphenol-rich apple juice extract (AE02) was found to effectively inhibit the kinase activity of GSK3beta, immunoprecipitated from HT29 cells. Treatment of HT29 cells with AE02 for 24 h resulted in a concentration-dependent decrease of the cellular GSK3beta kinase activity. The inhibition of the kinase activity in HT29 cells was observed at polyphenol concentrations corresponding to the concentration of the constituents in the original apple juice. The apple characteristic dihydrochalcone glycoside phloridzin was found to be inactive up to 500 muM. The free aglycon phloretin as well as the flavonol quercetin effectively inhibited isolated GSK3beta, but did not affect the respective kinase activity within HT29 cells. In accordance with the inhibition of GSK3beta kinase activity by AE02, treatment of HT29 cells resulted in a significant decrease of phosphorylated beta-catenin. However, the total intracellular beta-catenin level was also found to be diminished, indicating that the interference of the apple constituents with GSK3beta was not associated with a stabilization of beta-catenin in HT29 cells. In line with these results, TCF/LEF-mediated gene transcription remained unaffected by treatment with AE02 as shown in a reporter gene approach. We can assume from the results that at consumer-relevant concentrations

  17. Inhibition of melanogenesis by the pyridinyl imidazole class of compounds: possible involvement of the Wnt/β-catenin signaling pathway.

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    Barbara Bellei

    Full Text Available While investigating the role of p38 MAPK in regulating melanogenesis, we found that pyridinyl imidazole inhibitors class compounds as well as the analog compound SB202474, which does not inhibit p38 MAPK, suppressed both α-MSH-induced melanogenesis and spontaneous melanin synthesis. In this study, we demonstrated that the inhibitory activity of the pyridinyl imidazoles correlates with inhibition of the canonical Wnt/β-catenin pathway activity. Imidazole-treated cells showed a reduction in the level of Tcf/Lef target genes involved in the β-catenin signaling network, including ubiquitous genes such as Axin2, Lef1, and Wisp1 as well as cell lineage-restricted genes such as microphthalmia-associated transcription factor and dopachrome tautomerase. Although over-expression of the Wnt signaling pathway effector β-catenin slightly restored the melanogenic program, the lack of complete reversion suggested that the imidazoles interfered with β-catenin-dependent transcriptional activity rather than with β-catenin expression. Accordingly, we did not observe any significant change in β-catenin protein expression. The independence of p38 MAPK activity from the repression of Wnt/β-catenin signaling pathway was confirmed by small interfering RNA knockdown of p38 MAPK expression, which by contrast, stimulated β-catenin-driven gene expression. Our data demonstrate that the small molecule pyridinyl imidazoles possess two distinct and opposite mechanisms that modulate β-catenin dependent transcription: a p38 inhibition-dependent effect that stimulates the Wnt pathway by increasing β-catenin protein expression and an off-target mechanism that inhibits the pathway by repressing β-catenin protein functionality. The p38-independent effect seems to be dominant and, at least in B16-F0 cells, results in a strong block of the Wnt/β-catenin signaling pathway.

  18. Effect of aspirin on the Wnt/beta-catenin pathway is mediated via protein phosphatase 2A

    NARCIS (Netherlands)

    Bos, C. L.; Kodach, L. L.; van den Brink, G. R.; Diks, S. H.; van Santen, M. M.; Richel, D. J.; Peppelenbosch, M. P.; Hardwick, J. C. H.

    2006-01-01

    Nonsteroidal anti-inflammatory drugs show chemopreventive efficacy in colon cancer, but the mechanism behind this remains unclear. Elucidating this mechanism is seen as vital to the development of new chemopreventive agents. We studied the effects of aspirin on the oncogenic Wnt/beta-catenin pathway

  19. Neuroprotective effect of rapamycin on spinal cord injury via activation of the Wnt/β-catenin signaling pathway

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    Kai Gao

    2015-01-01

    Full Text Available The Wnt/β-catenin signaling pathway plays a crucial role in neural development, axonal guidance, neuropathic pain remission and neuronal survival. In this study, we initially examined the effect of rapamycin on the Wnt/β-catenin signaling pathway after spinal cord injury, by intraperitoneally injecting spinal cord injured rats with rapamycin over 2 days. Western blot analysis and immunofluorescence staining were used to detect the expression levels of β-catenin protein, ca-spase-3 protein and brain-derived neurotrophic factor protein, components of the Wnt/β-catenin signaling pathway. Rapamycin increased the levels of β-catenin and brain-derived neurotrophic factor in the injured spinal cord, improved the pathological morphology at the injury site, reduced the loss of motor neurons, and promoted motor functional recovery in rats after spinal cord injury. Our experimental findings suggest that the neuroprotective effect of rapamycin intervention is mediated through activation of the Wnt/β-catenin signaling pathway after spinal cord injury.

  20. Kirenol inhibits adipogenesis through activation of the Wnt/β-catenin signaling pathway in 3T3-L1 adipocytes

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    Kim, Mi-Bo [Department of Biomaterials Science and Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of); Song, Youngwoo; Kim, Changhee [Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of); Hwang, Jae-Kwan, E-mail: jkhwang@yonsei.ac.kr [Department of Biomaterials Science and Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of); Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of)

    2014-03-07

    Highlights: • Kirenol inhibits the adipogenic transcription factors and lipogenic enzymes. • Kirenol stimulates the Wnt/β-catenin signaling pathway components. • Kirenol inhibits adipogenesis through activation of the Wnt/β-catenin signaling pathway. - Abstract: Kirenol, a natural diterpenoid compound, has been reported to possess anti-oxidant, anti-inflammatory, anti-allergic, and anti-arthritic activities; however, its anti-adipogenic effect remains to be studied. The present study evaluated the effect of kirenol on anti-adipogenesis through the activation of the Wnt/β-catenin signaling pathway. Kirenol prevented intracellular lipid accumulation by down-regulating key adipogenesis transcription factors [peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer binding proteins α (C/EBPα), and sterol regulatory element binding protein-1c (SREBP-1c)] and lipid biosynthesis-related enzymes [fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC)], as well as adipocytokines (adiponectin and leptin). Kirenol effectively activated the Wnt/β-catenin signaling pathway, in which kirenol up-regulated the expression of low density lipoprotein receptor related protein 6 (LRP6), disheveled 2 (DVL2), β-catenin, and cyclin D1 (CCND1), while it inactivated glycogen synthase kinase 3β (GSK3β) by increasing its phosphorylation. Kirenol down-regulated the expression levels of PPARγ and C/EBPα, which were up-regulated by siRNA knockdown of β-catenin. Overall, kirenol is capable of inhibiting the differentiation and lipogenesis of 3T3-L1 adipocytes through the activation of the Wnt/β-catenin signaling pathway, suggesting its potential as natural anti-obesity agent.

  1. The effect of maternal diabetes on the Wnt-PCP pathway during embryogenesis as reflected in the developing mouse eye

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    Beatriz López-Escobar

    2015-02-01

    Full Text Available Embryopathies that develop as a consequence of maternal diabetes have been studied intensely in both experimental and clinical scenarios. Accordingly, hyperglycaemia has been shown to downregulate the expression of elements in the non-canonical Wnt-PCP pathway, such as the Dishevelled-associated activator of morphogenesis 1 (Daam1 and Vangl2. Daam1 is a formin that is essential for actin polymerization and for cytoskeletal reorganization, and it is expressed strongly in certain organs during mouse development, including the eye, neural tube and heart. Daam1gt/gt and Daam1gt/+ embryos develop ocular defects (anophthalmia or microphthalmia that are similar to those detected as a result of hyperglycaemia. Indeed, studying the effects of maternal diabetes on the Wnt-PCP pathway demonstrated that there was strong association with the Daam1 genotype, whereby the embryopathy observed in Daam1gt/+ mutant embryos of diabetic dams was more severe. There was evidence that embryonic exposure to glucose in vitro diminishes the expression of genes in the Wnt-PCP pathway, leading to altered cytoskeletal organization, cell shape and cell polarity in the optic vesicle. Hence, the Wnt-PCP pathway appears to influence cell morphology and cell polarity, events that drive the cellular movements required for optic vesicle formation and that, in turn, are required to maintain the fate determination. Here, we demonstrate that the Wnt-PCP pathway is involved in the early stages of mouse eye development and that it is altered by diabetes, provoking the ocular phenotype observed in the affected embryos.

  2. Analysis of molecular aberrations of Wnt pathway gladiators in colorectal cancer in the Kashmiri population

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    Sameer A

    2011-07-01

    Full Text Available Abstract The development and progression of colorectal cancer (CRC is a multi-step process, and the Wnt pathways with its two molecular gladiators adenomatous polyposis coli (APC and β-catenin plays an important role in transforming a normal tissue into a malignant one. In this study, we aimed to investigate the role of aberrations in the APC and β-catenin genes in the pathogenesis of CRC in the Kashmir valley, and to correlate it with various clinicopathological variables. We examined the paired tumour and normal-tissue specimens of 86 CRC patients for the occurrence of aberrations in the mutation cluster region (MCR of the APC gene and exon 3 of the β-catenin gene by polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP and/or PCR-direct sequencing. Analysis of promoter hypermethylation of the APC gene was also carried out using methylation-specific PCR (MS-PCR. The overall mutation rate of the MCR of the APC gene among 86 CRC cases was 12.8 per cent (11 of 86. Promoter hypermethylation of APC was observed in 54.65 per cent (47 of 86 of cases. Furthermore, we found a significant association between tumour location, tumour grade and node status and the methylation status of the APC gene (p ≤ 0.05. Although the number of mutations in the APC and β-catenin genes in our CRC cases was very low, the study confirms the role of epigenetic gene silencing of the pivotal molecular gladiator, APC, of the Wnt pathway in the development of CRC in the Kashmiri population.

  3. Analysis of molecular aberrations of Wnt pathway gladiators in colorectal cancer in the Kashmiri population.

    Science.gov (United States)

    Syed Sameer, A; Shah, Zaffar A; Abdullah, Safiya; Chowdri, Nissar A; Siddiqi, Mushtaq A

    2011-07-01

    The development and progression of colorectal cancer (CRC) is a multi-step process, and the Wnt pathways with its two molecular gladiators adenomatous polyposis coli (APC) and β-catenin plays an important role in transforming a normal tissue into a malignant one. In this study, we aimed to investigate the role of aberrations in the APC and β-catenin genes in the pathogenesis of CRC in the Kashmir valley, and to correlate it with various clinicopathological variables. We examined the paired tumour and normal-tissue specimens of 86 CRC patients for the occurrence of aberrations in the mutation cluster region (MCR) of the APC gene and exon 3 of the β-catenin gene by polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and/or PCR-direct sequencing. Analysis of promoter hypermethylation of the APC gene was also carried out using methylation-specific PCR (MS-PCR). The overall mutation rate of the MCR of the APC gene among 86 CRC cases was 12.8 per cent (11 of 86). Promoter hypermethylation of APC was observed in 54.65 per cent (47 of 86) of cases. Furthermore, we found a significant association between tumour location, tumour grade and node status and the methylation status of the APC gene (p ≤ 0.05). Although the number of mutations in the APC and β-catenin genes in our CRC cases was very low, the study confirms the role of epigenetic gene silencing of the pivotal molecular gladiator, APC, of the Wnt pathway in the development of CRC in the Kashmiri population.

  4. Dichlorodiphenyltrichloroethane exposure induces the growth of hepatocellular carcinoma via Wnt/β-catenin pathway.

    Science.gov (United States)

    Jin, Xiao-Ting; Song, Li; Zhao, Jun-Yu; Li, Zhuo-Yu; Zhao, Mei-Rong; Liu, Wei-Ping

    2014-02-10

    Dichlorodiphenyltrichloroethane (DDT) is a persistent organic pollutant, involved in the progression of many cancers, including liver cancer. However, the underlying mechanism(s) of DDT, especially how low doses DDT cause liver cancer, is poorly understood. In this study, we evaluated the impact of p,p'-DDT on the growth of hepatocellular carcinoma using both in vitro and in vivo models. The present data indicated that the proliferation of HepG2 cells was strikingly promoted after exposed to p,p'-DDT for 4 days. In addition, reactive oxygen species (ROS) content was significantly elevated, accompanied with inhibitions of γ-glutamylcysteine synthetase (γ-GCS) and superoxide dismutase (SOD) activities. Interestingly, the levels of β-catenin and its downstream target genes (c-Myc and CyclinD1) were significantly up-regulated, and co-treatment of NAC, the ROS inhibitor, inhibited these over-expressed proteins. Moreover, the p,p'-DDT-stimulated proliferation of HepG2 cells could be reversed after NAC or β-catenin siRNA co-treatment. Likewise, p,p'-DDT treatment increased the growth of tumor in nude mice, stimulated oxidative stress and Wnt/β-catenin pathway. Our study indicates that low doses p,p'-DDT exposure promote the growth of hepatocellular carcinoma via Wnt/β-catenin pathway which is activated by oxidative stress. The finding suggests an association between low dose DDT exposure and liver cancer growth. Crown Copyright © 2013. Published by Elsevier Ireland Ltd. All rights reserved.

  5. Involvement of Wnt signaling pathway in murine medulloblastoma induced by human neurotropic JC virus.

    Science.gov (United States)

    Gan, D D; Reiss, K; Carrill, T; Del Valle, L; Croul, S; Giordano, A; Fishman, P; Khalili, K

    2001-08-09

    By using the early genome of the human neurotropic polyomavirus, JCV, we have created transgenic animals that develop cerebellar primitive neuroectodermal tumors which model human medulloblastoma. Expression of T-antigen was found in some, but not all, tumor cells, and examination of the clonal cell lines derived from the tumor population showed enhanced tumorigenicity of cells expressing T-antigen in comparison to T-antigen negative cells. Considering the earlier notion on the potential involvement of beta-catenin with human medulloblastoma, we investigated various components of the Wnt signaling pathway including beta-catenin, its partner transcription factor, LEF-1, and their downstream target gene c-myc in these two cell populations. Immunohistochemical staining of the cells revealed enhanced nuclear appearance of beta-catenin in T-antigen positive cells. Results from Western blot showed higher levels of beta-catenin and LEF-1 in T-antigen positive cells in comparison to those in T-antigen negative cells. The enhanced level of LEF-1 expression correlated with the increase in DNA binding activity of this protein in nuclear extracts of T-antigen positive cells. Results from Northern and Western blot analyses revealed that the level of c-myc expression is augmented both at the RNA and protein levels in T-antigen positive cells. These observations corroborated results from transfection studies indicating the ability of JCV T-antigen to stimulate c-myc promoter activity. Further, co-transfection experiments revealed that the amount of c-myc and T-antigen protein in tumor cells may dictate the activity of JCV early promoter in these cells. These observations are interesting in light of recent discoveries on the association of JCV with human medulloblastoma and suggest that communication between JCV and the Wnt pathway may be an important event in the genesis of these tumors.

  6. Therapeutic effect of a novel Wnt pathway inhibitor on cardiac regeneration after myocardial infarction.

    Science.gov (United States)

    Yang, Dezhong; Fu, Wenbin; Li, Liangpeng; Xia, Xuewei; Liao, Qiao; Yue, Rongchuan; Chen, Hongmei; Chen, Xiongwen; An, Songzhu; Zeng, Chunyu; Wang, Wei Eric

    2017-12-15

    After myocardial infarction (MI), the heart is difficult to repair because of great loss of cardiomyoctyes and lack of cardiac regeneration. Novel drug candidates that aim at reducing pathological remodeling and stimulating cardiac regeneration are highly desirable. In the present study, we identified if and how a novel porcupine inhibitor CGX1321 influenced MI and cardiac regeneration. Permanent ligation of left anterior descending (LAD) coronary artery was performed in mice to induce MI injury. Cardiac function was measured by echocardiography, infarct size was examined by TTC staining. Fibrosis was evaluated with Masson's trichrome staining and vimentin staining. As a result, CGX1321 administration blocked the secretion of Wnt proteins, and inhibited both canonical and non-canonical Wnt signaling pathways. CGX1321 improved cardiac function, reduced myocardial infarct size, and fibrosis of post-MI hearts. CGX1321 significantly increased newly formed cardiomyocytes in infarct border zone of post-MI hearts, evidenced by the increased EdU+ cardiomyocytes. Meanwhile, CGX1321 increased Ki67+ and phosphohistone H3 (PH3+) cardiomyocytes in culture, indicating enhanced cardiomyocyte proliferation. The mRNA microarray showed that CGX1321 up-regulated cell cycle regulating genes such as Ccnb1 and Ccne1 CGX1321 did not alter YAP protein phosphorylation and nuclear translocation in cardiomyocytes. In conclusion, porcupine inhibitor CGX1321 reduces MI injury by limiting fibrosis and promoting regeneration. It promotes cardiomyocyte proliferation by stimulating cell cycle regulating genes with a Hippo/YAP-independent pathway. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  7. Activation of non-canonical Wnt/JNK pathway by Wnt3a is associated with differentiation fate determination of human bone marrow stromal (mesenchymal) stem cells

    DEFF Research Database (Denmark)

    Qiu, Weimin; Chen, Li; Kassem, Moustapha

    2011-01-01

    patterns induced by Wnt3a treatment in two hMSC lines: hMSC-LRP5(T253) and hMSC-LRP5(T244) cells carrying known mutations of Wnt co-receptor LRP5 (T253I or T244M) that either enhances or represses canonical Wnt signaling, respectively. Wnt3a treatment of hMSC activated not only canonical Wnt signaling...

  8. Wnt/β-catenin pathway involvement in ionizing radiation-induced invasion of U87 glioblastoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Zhen [Huazhong University of Science and Technology, Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Wuhan (China); Zhou, Lin [Huazhong University of Science and Technology, Department of Histoembryology, Tongji Medical College, Wuhan (China); Han, Na; Zhang, Mengxian [Huazhong University of Science and Technology, Department of Oncology, Tongji Hospital, Tongji Medical College, Wuhan (China); Lyu, Xiaojuan [Huazhong University of Science and Technology, Department of Oncology, The Central Hospital of Wuhan, Tongji Medical College, Wuhan (China)

    2015-08-15

    Radiotherapy has been reported to promote the invasion of glioblastoma cells; however, the underlying mechanisms remain unclear. Here, we investigated the role of the Wnt/β-catenin pathway in radiation-induced invasion of glioblastoma cells. U87 cells were irradiated with 3 Gy or sham irradiated in the presence or absence of the Wnt/β-catenin pathway inhibitor XAV 939. Cell invasion was determined by an xCELLigence real-time cell analyser and matrigel invasion assays. The intracellular distribution of β-catenin in U87 cells with or without irradiation was examined by immunofluorescence and Western blotting of nuclear fractions. We next investigated the effect of irradiation on Wnt/β-catenin pathway activity using TOP/FOP flash luciferase assays and quantitative polymerase chain reaction analysis of β-catenin target genes. The expression levels and activities of two target genes, matrix metalloproteinase (MMP)-2 and MMP-9, were examined further by Western blotting and zymography. U87 cell invasiveness was increased significantly by ionizing radiation. Interestingly, ionizing radiation induced nuclear translocation and accumulation of β-catenin. Moreover, we found increased β-catenin/TCF transcriptional activities, followed by up-regulation of downstream genes in the Wnt/β-catenin pathway in irradiated U87 cells. Importantly, inhibition of the Wnt/β-catenin pathway by XAV 939, which promotes degradation of β-catenin, significantly abrogated the pro-invasion effects of irradiation. Mechanistically, XAV 939 suppressed ionizing radiation-triggered up-regulation of MMP-2 and MMP-9, and inhibited the activities of these gelatinases. Our data demonstrate a pivotal role of the Wnt/β-catenin pathway in ionizing radiation-induced invasion of glioblastoma cells, and suggest that targeting β-catenin is a promising therapeutic approach to overcoming glioma radioresistance. (orig.) [German] Studien haben gezeigt, dass eine Strahlentherapie die Invasivitaet von

  9. Endometriotic mesenchymal stem cells significantly promote fibrogenesis in ovarian endometrioma through the Wnt/β-catenin pathway by paracrine production of TGF-β1 and Wnt1.

    Science.gov (United States)

    Li, Jing; Dai, Yongdong; Zhu, Haiyan; Jiang, Yinshen; Zhang, Songying

    2016-06-01

    Are endometriotic mesenchymal stem cells (Ecto-MSCs) involved in the fibrosis of ovarian endometrioma? Ecto-MSCs enhanced the fibrotic behavior of stromal cells in ovarian endometrioma through the Wnt/β-catenin pathway by paracrine production of transforming growth factor-β1 (TGF-β1) and Wnt1. Endometriosis is characterized by ectopic outgrowth of endometrial stroma and glands surrounded by dense fibrous tissues. The pathogenesis of endometriosis, especially ovarian endometrioma-associated fibrosis, is still unknown. We analyzed endometrial samples from 15 patients of reproductive age with ovarian endometrioma and normal menstrual cycles. A total of 54 nude mice received a single injection of proliferative endometrial fragments from 14 individuals without endometriosis. Conditioned medium (CM) was collected from endometrial mesenchymal stem cells (Euto-MSCs) and Ecto-MSCs. The effects of CM on cell proliferation, migration, invasion and collagen gel contraction of endometrial and endometriotic stromal cells (Euto- and Ecto-ESCs) in ovarian endometrioma were evaluated by cell counting kit-8, transwell and collagen gel contraction assays. Effects of CM on fibrotic markers' expression [including α-smooth muscle actin, Type I collagen, connective tissue growth factor and fibronectin (FN)] in Euto- and Ecto-ESCs were determined by real-time reverse-transcription-polymerase chain reaction and western blotting. Additionally, fibrogenic effects of Ecto-MSC CM treatment on endometriotic implants were analyzed using a xenograft model of endometriosis in immunodeficient nude mice. Our results demonstrated that Ecto-MSC CM significantly promoted cell proliferation, migration, invasion and collagen gel contraction of Euto- and Ecto-ESCs from patients with ovarian endometrioma compared with control and Euto-MSC CM. Expression levels of fibrotic markers in Euto- and Ecto-ESCs were dramatically elevated after treatment with Ecto-MSC CM. Ecto-MSCs secreted higher levels of TGF

  10. A pedagogical walkthrough of computational modeling and simulation of Wnt signaling pathway using static causal models in MATLAB

    OpenAIRE

    Sinha, Shriprakash

    2016-01-01

    Simulation study in systems biology involving computational experiments dealing with Wnt signaling pathways abound in literature but often lack a pedagogical perspective that might ease the understanding of beginner students and researchers in transition, who intend to work on the modeling of the pathway. This paucity might happen due to restrictive business policies which enforce an unwanted embargo on the sharing of important scientific knowledge. A tutorial introduction to computational mo...

  11. Regulation of the Wnt/β-Catenin Signaling Pathway by Human Papillomavirus E6 and E7 Oncoproteins

    Directory of Open Access Journals (Sweden)

    Jesus Omar Muñoz Bello

    2015-08-01

    Full Text Available Cell signaling pathways are the mechanisms by which cells transduce external stimuli, which control the transcription of genes, to regulate diverse biological effects. In cancer, distinct signaling pathways, such as the Wnt/β-catenin pathway, have been implicated in the deregulation of critical molecular processes that affect cell proliferation and differentiation. For example, changes in β-catenin localization have been identified in Human Papillomavirus (HPV-related cancers as the lesion progresses. Specifically, β-catenin relocates from the membrane/cytoplasm to the nucleus, suggesting that this transcription regulator participates in cervical carcinogenesis. The E6 and E7 oncoproteins are responsible for the transforming activity of HPV, and some studies have implicated these viral oncoproteins in the regulation of the Wnt/β-catenin pathway. Nevertheless, new interactions of HPV oncoproteins with cellular proteins are emerging, and the study of the biological effects of such interactions will help to understand HPV-related carcinogenesis. Viruses 2015, 7 4735 This review addresses the accumulated evidence of the involvement of the HPV E6 and E7 oncoproteins in the activation of the Wnt/β-catenin pathway.

  12. A Wnt-planar polarity pathway instructs neurite branching by restricting F-actin assembly through endosomal signaling

    Science.gov (United States)

    Chen, Chun-Hao; Liao, Chien-Po

    2017-01-01

    Spatial arrangement of neurite branching is instructed by both attractive and repulsive cues. Here we show that in C. elegans, the Wnt family of secreted glycoproteins specify neurite branching sites in the PLM mechanosensory neurons. Wnts function through MIG-1/Frizzled and the planar cell polarity protein (PCP) VANG-1/Strabismus/Vangl2 to restrict the formation of F-actin patches, which mark branching sites in nascent neurites. We find that VANG-1 promotes Wnt signaling by facilitating Frizzled endocytosis and genetically acts in a common pathway with arr-1/β-arrestin, whose mutation results in defective PLM branching and F-actin patterns similar to those in the Wnt, mig-1 or vang-1 mutants. On the other hand, the UNC-6/Netrin pathway intersects orthogonally with Wnt-PCP signaling to guide PLM branch growth along the dorsal-ventral axis. Our study provides insights for how attractive and repulsive signals coordinate to sculpt neurite branching patterns, which are critical for circuit connectivity. PMID:28384160

  13. UV induced foot duplication in regenerating hydra is mediated by metalloproteinases and modulation of the Wnt pathway.

    Science.gov (United States)

    Krishnapati, Lakshmi-Surekha; Londhe, Rohini; Deoli, Vaishali; Barve, Apurva; Ghaskadbi, Saroj; Ghaskadbi, Surendra

    2016-01-01

    We have shown earlier that irradiation with UV induces duplication of foot in regenerating middle pieces of hydra. The present study was undertaken to elucidate the underlying mechanism(s) leading to this curious phenomenon. UV irradiation induced duplicated foot in about 30% of regenerating middle pieces. Metalloproteinases are important in foot formation, while Wnt pathway genes are important in head formation in hydra. The effect of UV irradiation on expression of these genes was studied by in situ hybridization and q-PCR. In whole polyps and middle pieces, UV irradiation led to up-regulation of HMP2 and HMMP, the two metalloproteinases involved in foot formation in hydra. HMP2 expression was significantly increased starting from 30 min post exposure to UV at 254 nm (500 J/m(2)), while HMMP showed significant up-regulation 6 h post UV exposure onwards. In middle pieces, increased expression of both metalloproteinases was observed only at 48 h. In whole polyps as well as in middle pieces, expression of Wnt3 and β-catenin was detected within 30 min of UV exposure and was accompanied by up-regulation of GSK3β, DKK3 and DKK1/2/4, inhibitors of the Wnt pathway. These conditions likely lead to inactivation of Wnt signaling. We therefore conclude that duplication of foot due to UV irradiation in regenerating middle pieces of hydra is a combined effect of up-regulation of metalloproteinases and inactivation of the Wnt pathway. Our results suggest that UV irradiation can be employed as a tool to understand patterning mechanisms during foot formation in hydra.

  14. TGF-β prevents phosphate-induced osteogenesis through inhibition of BMP and Wnt/β-catenin pathways.

    Science.gov (United States)

    Guerrero, Fátima; Herencia, Carmen; Almadén, Yolanda; Martínez-Moreno, Julio M; Montes de Oca, Addy; Rodriguez-Ortiz, María Encarnación; Diaz-Tocados, Juan M; Canalejo, Antonio; Florio, Mónica; López, Ignacio; Richards, William G; Rodriguez, Mariano; Aguilera-Tejero, Escolástico; Muñoz-Castañeda, Juan R

    2014-01-01

    Transforming growth factor-β (TGF-β) is a key cytokine during differentiation of mesenchymal stem cells (MSC) into vascular smooth muscle cells (VSMC). High phosphate induces a phenotypic transformation of vascular smooth muscle cells (VSMC) into osteogenic-like cells. This study was aimed to evaluate signaling pathways involved during VSMC differentiation of MSC in presence or not of high phosphate. Our results showed that TGF-β induced nuclear translocation of Smad3 as well as the expression of vascular smooth muscle markers, such as smooth muscle alpha actin, SM22α, myocardin, and smooth muscle-myosin heavy chain. The addition of high phosphate to MSC promoted nuclear translocation of Smad1/5/8 and the activation of canonical Wnt/β-catenin in addition to an increase in BMP-2 expression, calcium deposition and alkaline phosphatase activity. The administration of TGF-β to MSC treated with high phosphate abolished all these effects by inhibiting canonical Wnt, BMP and TGF-β pathways. A similar outcome was observed in high phosphate-treated cells after the inhibition of canonical Wnt signaling with Dkk-1. Conversely, addition of both Wnt/β-catenin activators CHIR98014 and lithium chloride enhanced the effect of high phosphate on BMP-2, calcium deposition and alkaline phosphatase activity. Full VSMC differentiation induced by TGF-β may not be achieved when extracellular phosphate levels are high. Moreover, TGF-β prevents high phosphate-induced osteogenesis by decreasing the nuclear translocation of Smad 1/5/8 and avoiding the activation of Wnt/β-catenin pathway.

  15. WNT/β-catenin pathway modulates the TNF-α-induced inflammatory response in bronchial epithelial cells.

    Science.gov (United States)

    Jang, Jaewoong; Jung, Yoonju; Chae, Seyeon; Chung, Sang-In; Kim, Seok-Min; Yoon, Yoosik

    2017-03-04

    In this study, TNF-α was found to activate the WNT/β-catenin pathway in BEAS-2B human bronchial epithelial cells. Levels of phospho-LRP6, Dvl-2, and phospho-GSK-3β were elevated, while that of Axin was reduced by TNF-α treatment. Nuclear translocation of β-catenin and the reporter activity of a β-catenin-responsive promoter were increased by TNF-α treatment. Under the same experimental conditions, TNF-α activated the NF-κB signaling, which includes the phosphorylation and degradation of IκB and nuclear translocation and target DNA binding of NF-κB, and it was found that an inhibitor of NF-κB activation, JSH-23, inhibited TNF-α-induced Wnt signaling as well as NF-κB signaling. It was also found that recombinant Wnt proteins induced NF-κB nuclear translocations and its target DNA binding, suggesting that Wnt signaling and NF-κB signaling were inter-connected. TNF-α-induced modulations of IκB and NF-κB as well as pro-inflammatory cytokine expression were significantly suppressed by the transfection of β-catenin siRNA compared to that of control siRNA. Transfection of a β-catenin expression plasmid augmented the TNF-α-induced modulations of IκB and NF-κB as well as pro-inflammatory cytokine expression. These results clearly demonstrated that the WNT/β-catenin pathway modulates the inflammatory response induced by TNF-α, suggesting that this pathway may be a useful target for the effective treatment of bronchial inflammation. Copyright © 2017. Published by Elsevier Inc.

  16. TGF-β prevents phosphate-induced osteogenesis through inhibition of BMP and Wnt/β-catenin pathways.

    Directory of Open Access Journals (Sweden)

    Fátima Guerrero

    Full Text Available BACKGROUND: Transforming growth factor-β (TGF-β is a key cytokine during differentiation of mesenchymal stem cells (MSC into vascular smooth muscle cells (VSMC. High phosphate induces a phenotypic transformation of vascular smooth muscle cells (VSMC into osteogenic-like cells. This study was aimed to evaluate signaling pathways involved during VSMC differentiation of MSC in presence or not of high phosphate. RESULTS: Our results showed that TGF-β induced nuclear translocation of Smad3 as well as the expression of vascular smooth muscle markers, such as smooth muscle alpha actin, SM22α, myocardin, and smooth muscle-myosin heavy chain. The addition of high phosphate to MSC promoted nuclear translocation of Smad1/5/8 and the activation of canonical Wnt/β-catenin in addition to an increase in BMP-2 expression, calcium deposition and alkaline phosphatase activity. The administration of TGF-β to MSC treated with high phosphate abolished all these effects by inhibiting canonical Wnt, BMP and TGF-β pathways. A similar outcome was observed in high phosphate-treated cells after the inhibition of canonical Wnt signaling with Dkk-1. Conversely, addition of both Wnt/β-catenin activators CHIR98014 and lithium chloride enhanced the effect of high phosphate on BMP-2, calcium deposition and alkaline phosphatase activity. CONCLUSIONS: Full VSMC differentiation induced by TGF-β may not be achieved when extracellular phosphate levels are high. Moreover, TGF-β prevents high phosphate-induced osteogenesis by decreasing the nuclear translocation of Smad 1/5/8 and avoiding the activation of Wnt/β-catenin pathway.

  17. A pedagogical walkthrough of computational modeling and simulation of Wnt signaling pathway using static causal models in MATLAB.

    Science.gov (United States)

    Sinha, Shriprakash

    2016-12-01

    Simulation study in systems biology involving computational experiments dealing with Wnt signaling pathways abound in literature but often lack a pedagogical perspective that might ease the understanding of beginner students and researchers in transition, who intend to work on the modeling of the pathway. This paucity might happen due to restrictive business policies which enforce an unwanted embargo on the sharing of important scientific knowledge. A tutorial introduction to computational modeling of Wnt signaling pathway in a human colorectal cancer dataset using static Bayesian network models is provided. The walkthrough might aid biologists/informaticians in understanding the design of computational experiments that is interleaved with exposition of the Matlab code and causal models from Bayesian network toolbox. The manuscript elucidates the coding contents of the advance article by Sinha (Integr. Biol. 6:1034-1048, 2014) and takes the reader in a step-by-step process of how (a) the collection and the transformation of the available biological information from literature is done, (b) the integration of the heterogeneous data and prior biological knowledge in the network is achieved, (c) the simulation study is designed, (d) the hypothesis regarding a biological phenomena is transformed into computational framework, and (e) results and inferences drawn using d -connectivity/separability are reported. The manuscript finally ends with a programming assignment to help the readers get hands-on experience of a perturbation project. Description of Matlab files is made available under GNU GPL v3 license at the Google code project on https://code.google.com/p/static-bn-for-wnt-signaling-pathway and https: //sites.google.com/site/shriprakashsinha/shriprakashsinha/projects/static-bn-for-wnt-signaling-pathway. Latest updates can be found in the latter website.

  18. Genetic Variants in the Wnt Signaling Pathway Are Not Associated with Survival Outcome of Non-Small Cell Lung Cancer in a Korean Population.

    Science.gov (United States)

    Yoo, Seung Soo; Hong, Mi Jeong; Choi, Jin Eun; Lee, Jang Hyuck; Baek, Sun Ah; Lee, Won Kee; Lee, So Yeon; Lee, Shin Yup; Lee, Jaehee; Cha, Seung Ick; Kim, Chang Ho; Cho, Sukki; Park, Jae Yong

    2016-03-01

    Recently, genetic variants in the WNT signaling pathway have been reported to affect the survival outcome of Caucasian patients with early stage non-small cell lung cancer (NSCLC). We therefore attempted to determine whether these same WNT signaling pathway gene variants had similar impacts on the survival outcome of NSCLC patients in a Korean population. A total of 761 patients with stages I-IIIA NSCLC were enrolled in this study. Eight variants of WNT pathway genes were genotyped and their association with overall survival and disease-free survival were analyzed. None of the eight variants were significantly associated with overall survival or disease-free survival. There were no differences in survival outcome after stratifying the subjects according to age, gender, smoking status, and histological type. These results suggest that genetic variants in the WNT signaling pathway may not affect the survival outcome of NSCLC in a Korean population.

  19. PTH1–34 Blocks Radiation-induced Osteoblast Apoptosis by Enhancing DNA Repair through Canonical Wnt Pathway*

    Science.gov (United States)

    Chandra, Abhishek; Lin, Tiao; Zhu, Ji; Tong, Wei; Huo, Yanying; Jia, Haoruo; Zhang, Yejia; Liu, X. Sherry; Cengel, Keith; Xia, Bing; Qin, Ling

    2015-01-01

    Focal radiotherapy for cancer patients has detrimental effects on bones within the radiation field and the primary clinical signs of bone damage include the loss of functional osteoblasts. We reported previously that daily injection of parathyroid hormone (PTH, 1–34) alleviates radiation-induced osteopenia in a preclinical radiotherapy model by improving osteoblast survival. To elucidate the molecular mechanisms, we irradiated osteoblastic UMR 106-01 cells and calvarial organ culture and demonstrated an anti-apoptosis effect of PTH1–34 on these cultures. Inhibitor assay indicated that PTH exerts its radioprotective action mainly through protein kinase A/β-catenin pathway. γ-H2AX foci staining and comet assay revealed that PTH efficiently promotes the repair of DNA double strand breaks (DSBs) in irradiated osteoblasts via activating the β-catenin pathway. Interestingly, Wnt3a alone also blocked cell death and accelerated DNA repair in primary osteoprogenitors, osteoblastic and osteocytic cells after radiation through the canonical signaling. Further investigations revealed that both Wnt3a and PTH increase the amount of Ku70, a core protein for initiating the assembly of DSB repair machinery, in osteoblasts after radiation. Moreover, down-regulation of Ku70 by siRNA abrogated the prosurvival effect of PTH and Wnt3a on irradiated osteoblasts. In summary, our results identify a novel role of PTH and canonical Wnt signaling in regulating DSB repair machinery and apoptosis in osteoblasts and shed light on using PTH1–34 or Wnt agonist as possible therapy for radiation-induced osteoporosis. PMID:25336648

  20. Methylprednisolone promotes recovery of neurological function after spinal cord injury: association with Wnt/β-catenin signaling pathway activation

    Directory of Open Access Journals (Sweden)

    Gong-biao Lu

    2016-01-01

    Full Text Available Some studies have indicated that the Wnt/β-catenin signaling pathway is activated following spinal cord injury, and expression levels of specific proteins, including low-density lipoprotein receptor related protein-6 phosphorylation, β-catenin, and glycogen synthase kinase-3β, are significantly altered. We hypothesized that methylprednisolone treatment contributes to functional recovery after spinal cord injury by inhibiting apoptosis and activating the Wnt/β-catenin signaling pathway. In the current study, 30 mg/kg methylprednisolone was injected into rats with spinal cord injury immediately post-injury and at 1 and 2 days post-injury. Basso, Beattie, and Bresnahan scores showed that methylprednisolone treatment significantly promoted locomotor functional recovery between 2 and 6 weeks post-injury. The number of surviving motor neurons increased, whereas the lesion size significantly decreased following methylprednisolone treatment at 7 days post-injury. Additionally, caspase-3, caspase-9, and Bax protein expression levels and the number of apoptotic cells were reduced at 3 and 7 days post-injury, while Bcl-2 levels at 7 days post-injury were higher in methylprednisolone-treated rats compared with saline-treated rats. At 3 and 7 days post-injury, methylprednisolone up-regulated expression and activation of the Wnt/β-catenin signaling pathway, including low-density lipoprotein receptor related protein-6 phosphorylation, β-catenin, and glycogen synthase kinase-3β phosphorylation. These results indicate that methylprednisolone-induced neuroprotection may correlate with activation of the Wnt/β-catenin signaling pathway.

  1. LRP4 association to bone properties and fracture and interaction with genes in the Wnt- and BMP signaling pathways.

    Science.gov (United States)

    Kumar, Jitender; Swanberg, Maria; McGuigan, Fiona; Callreus, Mattias; Gerdhem, Paul; Akesson, Kristina

    2011-09-01

    Osteoporosis is a common complex disorder in postmenopausal women leading to changes in the micro-architecture of bone and increased risk of fracture. Members of the low-density lipoprotein receptor-related protein (LRP) gene family regulates the development and physiology of bone through the Wnt/β-catenin (Wnt) pathway that in turn cross-talks with the bone morphogenetic protein (BMP) pathway. In two cohorts of Swedish women: OPRA (n=1002; age 75 years) and PEAK-25 (n=1005; age 25 years), eleven single nucleotide polymorphisms (SNPs) from Wnt pathway genes (LRP4; LRP5; G protein-coupled receptor 177, GPR177) were analyzed for association with Bone Mineral Density (BMD), rate of bone loss, hip geometry, quantitative ultrasound and fracture. Additionally, interaction of LRP4 with LRP5, GPR177 and BMP2 were analyzed. LRP4 (rs6485702) was associated with higher total body (TB) and lumbar spine (LS) BMD in the PEAK-25 cohort (p=0.006 and 0.005 respectively), and interaction was observed with LRP5 (p=0.007) and BMP2 (p=0.004) for TB BMD. LRP4 also showed significant interaction with LRP5 for femoral neck (FN) and LS BMD in this cohort. In the OPRA cohort, LRP4 polymorphisms were associated with significantly lower fracture incidence overall (p=0.008-0.001) and fewer hip fractures (rs3816614, p=0.006). Significant interaction in the OPRA cohort was observed for LRP4 with BMP2 and GPR177 for FN BMD as well as for rate of bone loss at TB and FN (p=0.007-0.0001). In conclusion, LRP4 and interaction between LRP4 and genes in the Wnt and BMP signaling pathways modulate bone phenotypes including peak bone mass and fracture, the clinical endpoint of osteoporosis. Copyright © 2011 Elsevier Inc. All rights reserved.

  2. VDR Activation Reduces Proteinuria and High-Glucose-Induced Injury of Kidneys and Podocytes by Regulating Wnt Signaling Pathway.

    Science.gov (United States)

    Guo, Jia; Lu, Congqun; Zhang, Fangxing; Yu, Haixia; Zhou, Mengwen; He, Meixia; Wang, Chunyan; Zhao, Zhanzheng; Liu, Zhangsuo

    2017-01-01

    Diabetic nephropathy (DN) is a major cause of end-stage renal disease and proteinuria is one of the most prominent clinical manifestations. The expression of Vitamin D receptor (VDR) in patients with chronic kidney diseases was decreased, while VDR agonists could partially alleviate the proteinuria of DN in animal models. The present study was designed to determine the expression of VDR in renal tissues and its relationship with proteinuria the diabetic model db/db mice. The regulation effects of VDR on the Wnt signaling pathway were analyzed using RNA interference and VDR agonist paricalcitol. With the increase in age of the db/db mice, the VDR protein and mRNA levels in renal tissues were decreased, proteinuria increased, and the protein and mRNA levels of GSK-3β of and β-catenin increased. Paricalcitol treatment resulted in the up-regulation of VDR and down-regulation of GSK-3β and β-catenin, indicating that VDR had a regulatory effect on the Wnt signaling pathway. VDR activation could reduce proteinuria of DN mice and alleviate high-glucose-induced injury of kidneys and podocytes by regulating the key molecules of Wnt signaling pathway. © 2017 The Author(s). Published by S. Karger AG, Basel.

  3. VDR Activation Reduces Proteinuria and High-Glucose-Induced Injury of Kidneys and Podocytes by Regulating Wnt Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Jia Guo

    2017-08-01

    Full Text Available Background: Diabetic nephropathy (DN is a major cause of end-stage renal disease and proteinuria is one of the most prominent clinical manifestations. The expression of Vitamin D receptor (VDR in patients with chronic kidney diseases was decreased, while VDR agonists could partially alleviate the proteinuria of DN in animal models. The present study was designed to determine the expression of VDR in renal tissues and its relationship with proteinuria the diabetic model db/db mice. Methods: The regulation effects of VDR on the Wnt signaling pathway were analyzed using RNA interference and VDR agonist paricalcitol. Results: With the increase in age of the db/db mice, the VDR protein and mRNA levels in renal tissues were decreased, proteinuria increased, and the protein and mRNA levels of GSK-3β of and β-catenin increased. Paricalcitol treatment resulted in the up-regulation of VDR and down-regulation of GSK-3β and β-catenin, indicating that VDR had a regulatory effect on the Wnt signaling pathway. Conclusion: VDR activation could reduce proteinuria of DN mice and alleviate high-glucose-induced injury of kidneys and podocytes by regulating the key molecules of Wnt signaling pathway.

  4. Fructose-1,6-bisphosphatase is a novel regulator of Wnt/β-Catenin pathway in breast cancer.

    Science.gov (United States)

    Li, Kaichun; Ying, Mingzhen; Feng, Dan; Du, Jie; Chen, Shiyu; Dan, Bing; Wang, Cuihua; Wang, Yajie

    2016-12-01

    Fructose-1,6-bisphosphatase (FBP1), the rate-limiting enzyme in gluconeogenesis, is a tumor suppressor that frequently down-regulated in cancers, especially breast cancer. Here, we provide both supporting and contradicting evidences about the expression pattern and function of FBP1 in breast cancer. Data mining of Oncomine database showed that FBP1 is commonly up-regulated in tumor tissues compared with non-tumor tissues regardless of histological type. Analysis of a large-scale cohort derived from Kaplan-Meier Plotter showed that lower FBP1 expression associated with poor clinical outcome. Genetic silencing of FBP1 reduced aerobic glycolysis and the malignant potential of breast cancer cells. Gene set enrichment analysis (GSEA) of the expression profiles of breast cancer cells (n=59) revealed that cells exhibiting high expression of FBP1 had a lower activity of Wnt/β-Catenin pathway. FBP1 down-regulation enhanced the activity of Wnt/β-Catenin pathway and increased the level of its downstream targets, including c-Myc and MMP7. Collectively, our findings indicate that elevated FBP1 is a critical modulator in breast cancer progression by altering glucose metabolism and the activity of Wnt/β-Catenin pathway. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  5. WNT6 promotes the migration and differentiation of human dental pulp cells partly through c-Jun N-terminal kinase signaling pathway.

    Science.gov (United States)

    Li, Ruimin; Wang, Chenglin; Tong, Juan; Su, Yingying; Lin, Yunfeng; Zhou, Xuedong; Ye, Ling

    2014-07-01

    During the dental pulp repair process, human dental pulp cells (HDPCs) migrate to injury sites where they may differentiate into odontoblastlike cells. WNT6 plays a role in dental development and can activate a noncanonical pathway including the c-Jun N-terminal kinase (JNK) pathway. The mechanism of WNT6 in dental pulp repair is still unknown. The purpose of this study was to explore the potential role of the WNT6/JNK signaling pathway in the promotion of cell migration and the differentiation of HDPCs. The third passage of HDPCs were cultured in vitro and treated with WNT6 conditioned medium with or without the pretreatment of JNK inhibitor SP600125. The activation of JNK was detected by Western blot, the expression of c-Jun was quantified by reverse-transcription polymerase chain reaction, the migration of HDPCs was determined by wound healing and transwell migration assays, and the differentiation of HDPCs was investigated using alkaline phosphatase staining and alizarin red staining. The expression of odontogenesis-related genes such as Runt-related transcription factor 2, dentin sialophosphoprotein, and dentin matrix protein 1 was quantified. WNT6 activates the JNK pathway in HDPCs and enhances cell migration, mineralization nodule formation, and alkaline phosphatase activation. WNT6 also increases the expression of Runt-related transcription factor 2, dentin sialophosphoprotein, and dentin matrix protein messenger RNA in HDPCs. Blockage of the JNK pathway in HDPCs decreases but does not completely abolish the cell migration and differentiation capacity induced by WNT6. WNT6 activates the JNK signaling pathway in HDPCs, leading to migration and differentiation. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  6. Relationship of vegetal cortical dorsal factors in the Xenopus egg with the Wnt/beta-catenin signaling pathway.

    Science.gov (United States)

    Marikawa, Y; Elinson, R P

    1999-12-01

    In Xenopus, the dorsal factor in the vegetal cortical cytoplasm (VCC) of the egg is responsible for axis formation of the embryo. Previous studies have shown that VCC dorsal factor has properties similar to activators of the Wnt/beta-catenin-signaling pathway. In this study, we examined the relationship of the VCC dorsal factor with components of the pathway. First, we tested whether beta-catenin protein, which is known to be localized on the dorsal side of early embryos, accounts for the dorsal axis activity of VCC. Reduction of beta-catenin mRNA and protein in oocytes did not diminish the activity of VCC to induce a secondary axis in recipient embryos. The amount of beta-catenin protein was not enriched in VCC compared to animal cortical cytoplasm, which has no dorsal axis activity. These results indicate that beta-catenin is unlikely to be the VCC dorsal axis factor. Secondly, we examined the effects of four Wnt-pathway-interfering constructs (dominant-negative Xdsh, XGSK3, Axin, and dominant-negative XTcf3) on the ability of VCC to induce expression of the early Wnt target genes, Siamois and Xnr3. The activity of VCC was inhibited by Axin and dominant negative XTcf3 but not by dominant negative Xdsh or XGSK3. We also showed that VCC decreased neither the amount nor the activity of exogenous XGSK3, suggesting that the VCC dorsal factor does not act by affecting XGSK3 directly. Finally, we tested six Wnt-pathway activating constructs (Xwnt8, Xdsh, dominant negative XGSK3, dominant negative Axin, XAPC and beta-catenin) for their responses to the four Wnt-pathway-interfering constructs. We found that only XAPC exhibited the same responses as VCC; it was inhibited by Axin and dominant negative XTcf3 but not by dominant negative Xdsh or XGSK3. Although the connection between XAPC and the VCC dorsal factor is not yet clear, the fact that APC binds Axin suggests that the VCC dorsal factor could act on Axin rather than XGSK3.

  7. Crosstalk between MLO-Y4 osteocytes and C2C12 muscle cells is mediated by the Wnt/β-catenin pathway.

    Science.gov (United States)

    Huang, Jian; Romero-Suarez, Sandra; Lara, Nuria; Mo, Chenglin; Kaja, Simon; Brotto, Leticia; Dallas, Sarah L; Johnson, Mark L; Jähn, Katharina; Bonewald, Lynda F; Brotto, Marco

    2017-10-01

    We examined the effects of osteocyte secreted factors on myogenesis and muscle function. MLO-Y4 osteocyte-like cell conditioned media (CM) (10%) increased ex vivo soleus muscle contractile force by ~25%. MLO-Y4 and primary osteocyte CM (1-10%) stimulated myogenic differentiation of C2C12 myoblasts, but 10% osteoblast CMs did not enhance C2C12 cell differentiation. Since WNT3a and WNT1 are secreted by osteocytes, and the expression level of Wnt3a is increased in MLO-Y4 cells by fluid flow shear stress, both were compared, showing WNT3a more potent than WNT1 in inducing myogenesis. Treatment of C2C12 myoblasts with WNT3a at concentrations as low as 0.5ng/mL mirrored the effects of both primary osteocyte and MLO-Y4 CM by inducing nuclear translocation of β-catenin with myogenic differentiation, suggesting that Wnts might be potential factors secreted by osteocytes that signal to muscle cells. Knocking down Wnt3a in MLO-Y4 osteocytes inhibited the effect of CM on C2C12 myogenic differentiation. Sclerostin (100ng/mL) inhibited both the effects of MLO-Y4 CM and WNT3a on C2C12 cell differentiation. RT-PCR array results supported the activation of the Wnt/β-catenin pathway by MLO-Y4 CM and WNT3a. These results were confirmed by qPCR showing up-regulation of myogenic markers and two Wnt/β-catenin downstream genes, Numb and Flh1. We postulated that MLO-Y4 CM/WNT3a could modulate intracellular calcium homeostasis as the trigger mechanism for the enhanced myogenesis and contractile force. MLO-Y4 CM and WNT3a increased caffeine-induced Ca2+ release from the sarcoplasmic reticulum (SR) of C2C12 myotubes and the expression of genes directly associated with intracellular Ca2+ signaling and homeostasis. Together, these data show that in vitro and ex vivo, osteocytes can stimulate myogenesis and enhance muscle contractile function and suggest that Wnts could be mediators of bone to muscle signaling, likely via modulation of intracellular Ca2+ signaling and the Wnt

  8. The STAT3-miRNA-92-Wnt Signaling Pathway Regulates Spheroid Formation and Malignant Progression in Ovarian Cancer.

    Science.gov (United States)

    Chen, Min-Wei; Yang, Shu-Ting; Chien, Ming-Hsien; Hua, Kuo-Tai; Wu, Chin-Jui; Hsiao, S M; Lin, Hao; Hsiao, Michael; Su, Jen-Liang; Wei, Lin-Hung

    2017-04-15

    Ovarian cancer spheroids constitute a metastatic niche for transcoelomic spread that also engenders drug resistance. Spheroid-forming cells express active STAT3 signaling and display stem cell-like properties that may contribute to ovarian tumor progression. In this study, we show that STAT3 is hyperactivated in ovarian cancer spheroids and that STAT3 disruption in this setting is sufficient to relieve chemoresistance. In an NSG murine model of human ovarian cancer, STAT3 signaling regulated spheroid formation and self-renewal properties, whereas STAT3 attenuation reduced tumorigenicity. Mechanistic investigations revealed that Wnt signaling was required for STAT3-mediated spheroid formation. Notably, the Wnt antagonist DKK1 was the most strikingly upregulated gene in response to STAT3 attenuation in ovarian cancer cells. STAT3 signaling maintained stemness and interconnected Wnt/β-catenin signaling via the miR-92a/DKK1-regulatory pathways. Targeting STAT3 in combination with paclitaxel synergistically reduced peritoneal seeding and prolonged survival in a murine model of intraperitoneal ovarian cancer. Overall, our findings define a STAT3-miR-92a-DKK1 pathway in the generation of cancer stem-like cells in ovarian tumors, with potential therapeutic applications in blocking their progression. Cancer Res; 77(8); 1955-67. ©2017 AACR. ©2017 American Association for Cancer Research.

  9. Association of Canonical Wnt/β-Catenin Pathway and Type 2 Diabetes: Genetic Epidemiological Study in Han Chinese

    Directory of Open Access Journals (Sweden)

    Jinjin Wang

    2015-06-01

    Full Text Available We aimed to investigate the associations of polymorphisms in Canonical Wnt/β-catenin pathway (WNT signaling genes (including low-density lipoprotein-related protein 5 [LRP5] and transcription factor 7-like 2 [TCF7L2] gene and the downstream gene glucagon (GCG and risk of type 2 diabetes mellitus (T2DM in a Han Chinese population. We genotyped the single nucleotide polymorphisms (SNPs for LRP5, TCF7L2 and GCG gene were genotyped in 1842 patients with T2DM and 7777 normal glucose-tolerant healthy subjects. We used multifactor dimensionality reduction (MDR and multiplicative logistic regression adjusting for sex, age, anthropometric measurements and lipid levels to investigate the gene-gene interactions for the risk of T2DM. Among the five SNPs in LRP5, the recessive model of rs7102273 and the haplotype GCTCC were associated with T2DM risk; the haplotype GCTTC was associated with decreased risk. For TCF7L2, the rs11196218 genotype GA and the haplotype CCG, TTG, TTA were associated with T2DM risk; whereas, the haplotype CTG and TCG were associated with decreased risk. Both MDR and multiplicative logistic regression revealed potential gene–gene interactions among LRP5, TCF7L2, and GCG associated with T2DM. The WNT signaling pathway may play a significant role in risk of T2DM in Han Chinese people.

  10. Curcumin Rescues Diabetic Renal Fibrosis by Targeting Superoxide-Mediated Wnt Signaling Pathways.

    Science.gov (United States)

    Ho, Cheng; Hsu, Yung-Chien; Lei, Chen-Chou; Mau, Shu-Ching; Shih, Ya-Hsueh; Lin, Chun-Liang

    2016-03-01

    The purposes of this study were to investigate whether curcumin can weaken diabetic nephropathy by modulating both oxidative stress and renal injury from Wnt signaling mediation. Wnt5a/β-catenin depression and induction of superoxide synthesis are associated with high glucose (HG) induced transforming growth factor (TGF)-β1 and fibronectin expression in mesangial cells. Curcumin resumes HG depression of Wnt/β-catenin signaling and alleviates HG induction of superoxide, TGF-β1 and fibronectin expression in renal mesangial cell. Exogenous curcumin alleviated urinary total proteinuria and serum superoxide level in diabetic rats. Based on laser-captured microdissection for quantitative real-time polymerase chain reaction, it was found that diabetes significantly increased TGF-β1 and fibronectin expression in line with depressed Wnt5a expression. Curcumin treatment reduced the TGF-β1 and fibronectin activation and the inhibiting effect of diabetes on Wnt5a/β-catenin expression in renal glomeruli. Immunohistochemistry showed that curcumin treatment significantly reduced 8-hydroxy-2'-deoxyguanosine, TGF-β1 and fibronectin, and was in line with the restoration of the suppressed Wnt5a expression immunoreactivities in glomeruli of diabetic rats. Curcumin alleviated extracellular matrix accumulation in diabetic nephropathy by not only preventing the diabetes-mediated superoxide synthesis but also resuming downregulation of Wnt/β-catenin signaling. These findings suggest that regulation of Wnt activity by curcumin is a feasible alternative strategy to rescue diabetic renal injury. Copyright © 2016 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.

  11. Paracrine Activation of the Wnt/β-Catenin Pathway by Bone Marrow Stem Cell Attenuates Cisplatin-Induced Kidney Injury

    Directory of Open Access Journals (Sweden)

    Xiaoyan Jiao

    2017-12-01

    Full Text Available Background/Aims: Cisplatin-induced acute kidney injury (AKI involves damage to tubular cells via excess reactive oxygen species (ROS generation. Stem cell-based therapies have shown great promise in AKI treatment. In this study, we aimed to assess the protective effect and mechanism of bone marrow mesenchymal stem cell (BMSC-derived conditioned medium (CM against cisplatin-induced AKI. Methods: In vitro, NRK-52E cells were incubated with cisplatin in the presence or absence of CM, followed by the assessment of cell viability, apoptosis and cell cycle distribution. Then, ICG-001 and IWR-1 were used to inhibit the wnt/β-catenin pathway. Furthermore, intracellular and mitochondrial ROS levels were evaluated using DCFH-DA and MitoSOX, respectively. In vivo, after cisplatin injection, rats were intravenously injected with CM or BMSCs. Sera and kidney tissues were collected on day 3 after cisplatin injection to evaluate changes in renal function and histology. Western blotting and qRT-PCR were employed to determine the expression of wnt/β-catenin pathway-related genes and proteins. Immunohistochemical staining was used to evaluate tubular β-catenin expression in kidney biopsy from AKI patients. Results: CM protected NRK-52E cells from cisplatin-induced injury by restoring the wnt4/β-catenin pathway. In response to ICG-001 and IWR-1, the protective effect of CM was attenuated, characterized by a decrease in cell proliferation and an increase in cell apoptosis and intracellular and mitochondrial ROS levels. Knockdown of β-catenin using siRNAs also suppressed the mitochondrial biogenesis regulators PGC-1α, TFAM and NRF-1. In the rat model, CM significantly alleviated renal function and histology associated with tubular injury and upregulated wnt4 and β-catenin. However, the renoprotective effect of CM was blocked by ICG-001, characterized by exacerbated renal function, suppressed PGC-1α expression and increased mitochondrial ROS. Clinical data

  12. Shizukaol D, a Dimeric Sesquiterpene Isolated from Chloranthus serratus, Represses the Growth of Human Liver Cancer Cells by Modulating Wnt Signalling Pathway.

    Science.gov (United States)

    Tang, Lisha; Zhu, Hengrui; Yang, Xianmei; Xie, Fang; Peng, Jingtao; Jiang, Deke; Xie, Jun; Qi, Meiyan; Yu, Long

    2016-01-01

    Natural products have become sources of developing new drugs for the treatment of cancer. To seek candidate compounds that inhibit the growth of liver cancer, components of Chloranthus serratus were tested. Here, we report that shizukaol D, a dimeric sesquiterpene from Chloranthus serratus, exerted a growth inhibition effect on liver cancer cells in a dose- and time-dependent manner. We demonstrated that shizukaol D induced cells to undergo apoptosis. More importantly, shizukaol D attenuated Wnt signalling and reduced the expression of endogenous Wnt target genes, which resulted in decreased expression of β-catenin. Collectively, this study demonstrated that shizukaol D inhibited the growth of liver cancer cells by modulating Wnt pathway.

  13. A hypermorphic epithelial β-catenin mutation facilitates intestinal tumorigenesis in mice in response to compounding WNT-pathway mutations

    Directory of Open Access Journals (Sweden)

    Michael Buchert

    2015-11-01

    Full Text Available Activation of the Wnt/β-catenin pathway occurs in the vast majority of colorectal cancers. However, the outcome of the disease varies markedly from individual to individual, even within the same tumor stage. This heterogeneity is governed to a great extent by the genetic make-up of individual tumors and the combination of oncogenic mutations. In order to express throughout the intestinal epithelium a degradation-resistant β-catenin (Ctnnb1, which lacks the first 131 amino acids, we inserted an epitope-tagged ΔN(1-131-β-catenin-encoding cDNA as a knock-in transgene into the endogenous gpA33 gene locus in mice. The resulting gpA33ΔN-Bcat mice showed an increase in the constitutive Wnt/β-catenin pathway activation that shifts the cell fate towards the Paneth cell lineage in pre-malignant intestinal epithelium. Furthermore, 19% of all heterozygous and 37% of all homozygous gpA33ΔN-Bcat mice spontaneously developed aberrant crypt foci and adenomatous polyps, at frequencies and latencies akin to those observed in sporadic colon cancer in humans. Consistent with this, the Wnt target genes, MMP7  and Tenascin-C, which are most highly expressed in benign human adenomas and early tumor stages, were upregulated in pre-malignant tissue of gpA33ΔN-Bcat mice, but those Wnt target genes associated with excessive proliferation (i.e. Cdnn1, myc were not. We also detected diminished expression of membrane-associated α-catenin and increased intestinal permeability in gpA33ΔN-Bcat mice in challenge conditions, providing a potential explanation for the observed mild chronic intestinal inflammation and increased susceptibility to azoxymethane and mutant Apc-dependent tumorigenesis. Collectively, our data indicate that epithelial expression of ΔN(1-131-β-catenin in the intestine creates an inflammatory microenvironment and co-operates with other mutations in the Wnt/β-catenin pathway to facilitate and promote tumorigenesis.

  14. Curcumin promotes the apoptosis of human endometrial carcinoma cells by downregulating the expression of androgen receptor through Wnt signal pathway.

    Science.gov (United States)

    Feng, W; Yang, C X; Zhang, L; Fang, Y; Yan, M

    2014-01-01

    The current study aimed to explore the effect ofcurcumin on androgen receptor (AR) expression in endometrial carcinoma cells, as well as the underlying mechanisms. Endometrial carcinoma cells were treated with curcumin (10, 50, and 100 micromol/l) for 12, 24, and 48 hours. Their growth curves were drawn using MTT assays and their apoptotic rates were determined using flow cytometry. The mRNA and protein expression of AR was detected using PCR and that of the Wnt signal related nucleopro- tein beta-cantenin was observed using western blot analysis. The influence of beta-cantenin on the action of curcumin was observed. Curcumin downregulated the proliferation and apoptosis of human endometrial carcinoma cells in concentration and time-dependent manners. It downregulated the expression of AR and beta-cantenin in the cells. rWnt3a partially cancelled the effects of curcumin on the proliferation and apoptosis of human endometrial carcinoma cells as well as the AR expression-downregulating effect of curcumin. Curcumin inhibits the proliferation and apoptosis of human endometrial carcinoma cells by downregulating their AR expression through the Wnt signal pathway.

  15. CAETS 2015 Convocation on Pathways to Sustainability

    CERN Document Server

    Ghosh, Purnendu; Shorey, Rajeev; Tandon, Mahesh; v.1 Energy engineering; v.2 Healthcare engineering; v.3 Mobility engineering

    2017-01-01

    This book contains the proceedings of CAETS 2015 Convocation on ‘Pathways to Sustainability: Energy, Mobility and Healthcare Engineering’ that was held on October 13-14, 2015 in New Delhi. This 3 volume proceedings provide an international forum for discussion and communication of engineering and technological issues of common concern. This volume talks about ‘Energy’ and includes 22 chapters on diverse topics like renewable energy, advances and applications of bio-energy and bio-refinery, energy options and scenarios, wind energy for buildings and transportation, etc. The contents of this volume will be useful to researchers, professionals, and policy makers alike.

  16. Wnt/β-Catenin Signaling Pathway Is a Direct Enhancer of Thyroid Transcription Factor-1 in Human Papillary Thyroid Carcinoma Cells

    Science.gov (United States)

    Gilbert-Sirieix, Marie; Makoukji, Joelle; Kimura, Shioko; Talbot, Monique; Caillou, Bernard; Massaad, Charbel; Massaad-Massade, Liliane

    2011-01-01

    The Wnt/β-catenin signaling pathway is involved in the normal development of thyroid gland, but its disregulation provokes the appearance of several types of cancers, including papillary thyroid carcinomas (PTC) which are the most common thyroid tumours. The follow-up of PTC patients is based on the monitoring of serum thyroglobulin levels which is regulated by the thyroid transcription factor 1 (TTF-1): a tissue-specific transcription factor essential for the differentiation of the thyroid. We investigated whether the Wnt/β-catenin pathway might regulate TTF-1 expression in a human PTC model and examined the molecular mechanisms underlying this regulation. Immunofluorescence analysis, real time RT-PCR and Western blot studies revealed that TTF-1 as well as the major Wnt pathway components are co-expressed in TPC-1 cells and human PTC tumours. Knocking-down the Wnt/β-catenin components by siRNAs inhibited both TTF-1 transcript and protein expression, while mimicking the activation of Wnt signaling by lithium chloride induced TTF-1 gene and protein expression. Functional promoter studies and ChIP analysis showed that the Wnt/β-catenin pathway exerts its effect by means of the binding of β-catenin to TCF/LEF transcription factors on the level of an active TCF/LEF response element at [−798, −792 bp] in TTF-1 promoter. In conclusion, we demonstrated that the Wnt/β-catenin pathway is a direct and forward driver of the TTF-1 expression. The localization of TCF-4 and TTF-1 in the same area of PTC tissues might be of clinical relevance, and justifies further examination of these factors in the papillary thyroid cancers follow-up. PMID:21814573

  17. Environmental Enrichment Improves Spatial Learning and Memory in Vascular Dementia Rats with Activation of Wnt/β-Catenin Signal Pathway.

    Science.gov (United States)

    Jin, Xinhao; Li, Tao; Zhang, Lina; Ma, Jingxi; Yu, Lehua; Li, Changqing; Niu, Lingchuan

    2017-01-13

    BACKGROUND Environmental enrichment (EE) has a beneficial effect on some neuropsychiatric disorders. In this study, we aimed to investigate whether environmental enrichment could improve the spatial learning and memory in rats with vascular dementia (VaD) and the mechanism underpinning it. MATERIAL AND METHODS Bilateral common carotid occlusion (2-vessel occlusion [2VO]) was used to develop the animal model of vascular dementia. Adult male Sprague-Dawley (SD) rats were used in the experiment and were randomly divided into 4 groups: sham group, 2VO group, sham+EE group, and 2VO+EE group (n=19/group). The 2VO group and 2VO+EE group underwent bilateral common carotid occlusion. Two different housing conditions were used in this experiment: standard environment (SE) and enriched environment (EE). Rats in the sham group and 2VO group were put into SE cages for 4 weeks, while rats in the sham+EE group and 2VO+EE group were put in EE cages for 4 weeks. The Morris water maze and Y-maze were used to assess spatial learning and memory. Apoptosis was detected by TUNEL. The damage of neurons in the hippocampus was assessed by Nissl staining. The level of wnt pathway proteins were detected by Western blot. RESULTS Compared with the 2VO group, the rats in the 2VO+EE group had better behavioral performance, fewer apoptotic neurons, and more surviving neurons. Western blot analysis showed that the levels of wnt pathway proteins were higher in 2VO+EE rats than in the 2VO group. CONCLUSIONS Environmental enrichment can improve the spatial learning and memory in rats with vascular dementia, and the mechanism may be related to activation of the wnt/β-catenin signal pathway.

  18. MicroRNA-152 modulates the canonical Wnt pathway activation by targeting DNA methyltransferase 1 in arthritic rat model.

    Science.gov (United States)

    Miao, Cheng-Gui; Yang, Ying-Ying; He, Xu; Huang, Cheng; Huang, Yan; Qin, Dan; Du, Chuan-Lai; Li, Jun

    2014-11-01

    Rheumatoid arthritis (RA) is an autoimmune and progressive systemic disease of unknown etiology. Research shows that fibroblast-like synoviocytes (FLS) participate in the cartilage erosion, synovial hyperplasia, inflammatory cytokine secretion and suggests that fibroblast-like synoviocytes (FLS) display a crucial role in RA pathogenesis. Recent studies have suggested the role of the Wnt signaling pathway in the pathogenesis of RA. In previous study, we identified that increased methyl-CpG-binding protein 2 (MeCP2) reduced the secreted frizzled-related protein 4 (SFRP4) expression in FLS in Arthritic rat model and the DNA methyltransferase (DNMT) inhibitor 5-Aza-2'-deoxycytidine (5-azadC) could induce the SFRP4 expression, indicating that DNMT has a key role in the differential expression of SFRP4. MicroRNAs (MiRNAs), which are small non-coding RNAs, are involved in diverse biological functions, regulation of gene expression, pathogenesis of autoimmune disease and carcinogenesis. In light of the directly down-regulation of miR-152 on DNMT1 expression by targeting the 3' untranslated regions of its transcript in nickel sulfide (NiS)-transformed human bronchial epithelial cells, we investigated whether miR-152 is aberrantly expressed and targets DNMT1 in FLS in Arthritic rat model. Our results demonstrated that the expression of miR-152 was specifically down-regulated in Arthritic rat model, whereas up-regulation of miR-152 in FLS resulted in a marked reduction of DNMT1 expression. Further experiments revealed that increased miR-152 indirectly up-regulated the SFRP4 expression, a negative regulator of WNT signaling pathway, by targeting the DNMT1. Moreover, activation of miR-152 expression in FLS could inhibit the canonical Wnt pathway activation and result in a significant decrease of FLS proliferation. MiR-152 and DNA methylation may provide molecular mechanisms for the activation of canonical Wnt pathway in RA. Combination of miR-152 and DNMT1 may be a promising

  19. Human Cytomegalovirus Inhibits the PARsylation Activity of Tankyrase--A Potential Strategy for Suppression of the Wnt Pathway.

    Science.gov (United States)

    Roy, Sujayita; Liu, Fengjie; Arav-Boger, Ravit

    2015-12-29

    Human cytomegalovirus (HCMV) was reported to downregulate the Wnt/β-catenin pathway. Induction of Axin1, the negative regulator of the Wnt pathway, has been reported as an important mechanism for inhibition of β-catenin. Since Tankyrase (TNKS) negatively regulates Axin1, we investigated the effect of HCMV on TNKS expression and poly-ADP ribose polymerase (PARsylation) activity, during virus replication. Starting at 24 h post infection, HCMV stabilized the expression of TNKS and reduced its PARsylation activity, resulting in accumulation of Axin1 and reduction in its PARsylation as well. General PARsylation was not changed in HCMV-infected cells, suggesting specific inhibition of TNKS PARsylation. Similarly, treatment with XAV939, a chemical inhibitor of TNKS' activity, resulted in the accumulation of TNKS in both non-infected and HCMV-infected cell lines. Reduction of TNKS activity or knockdown of TNKS was beneficial for HCMV, evidenced by its improved growth in fibroblasts. Our results suggest that HCMV modulates the activity of TNKS to induce Axin1, resulting in inhibition of the β-catenin pathway. Since HCMV replication is facilitated by TNKS knockdown or inhibition of its activity, TNKS may serve as an important virus target for control of a variety of cellular processes.

  20. Pathway Model of the Kinetics of the TGFbeta Antagonist Smad7 and Cross-Talk with the ATM and WNT Pathways

    Science.gov (United States)

    Carra, Claudio; Wang, Minli; Huff, Janice L.; Hada, Megumi; ONeill, Peter; Cucinotta, Francis A.

    2010-01-01

    Signal transduction controls cellular and tissue responses to radiation. Transforming growth factor beta (TGFbeta) is an important regulator of cell growth and differentiation and tissue homeostasis, and is often dis-regulated in tumor formation. Mathematical models of signal transduction pathways can be used to elucidate how signal transduction varies with radiation quality, and dose and dose-rate. Furthermore, modeling of tissue specific responses can be considered through mechanistic based modeling. We developed a mathematical model of the negative feedback regulation by Smad7 in TGFbeta-Smad signaling and are exploring possible connections to the WNT/beta -catenin, and ATM/ATF2 signaling pathways. A pathway model of TGFbeta-Smad signaling that includes Smad7 kinetics based on data in the scientific literature is described. Kinetic terms included are TGFbeta/Smad transcriptional regulation of Smad7 through the Smad3-Smad4 complex, Smad7-Smurf1 translocation from nucleus to cytoplasm, and Smad7 negative feedback regulation of the TGFO receptor through direct binding to the TGFO receptor complex. The negative feedback controls operating in this pathway suggests non-linear responses in signal transduction, which are described mathematically. We then explored possibilities for cross-talk mediated by Smad7 between DNA damage responses mediated by ATM, and with the WNT pathway and consider the design of experiments to test model driven hypothesis. Numerical comparisons of the mathematical model to experiments and representative predictions are described.

  1. A functional analysis of Wnt inducible signalling pathway protein -1 (WISP-1/CCN4).

    Science.gov (United States)

    Stephens, Sarah; Palmer, Joanne; Konstantinova, Irena; Pearce, Andrew; Jarai, Gabor; Day, Elizabeth

    2015-03-01

    Wnt-1 inducible signalling pathway protein 1 (WISP-1/CCN4) is an extracellular matrix protein that belongs to the Cyr61 (cysteine-rich protein 61), CTGF (connective tissue growth factor) and NOV (CCN) family and plays a role in multiple cellular processes. No specific WISP-1 receptors have been identified but emerging evidence suggests WISP-1 mediates its downstream effects by binding to integrins. Here we describe a functional analysis of integrin receptor usage by WISP-1. Truncated WISP-1 proteins were produced using a baculovirus expression system. Full length WISP-1 and truncated proteins were evaluated for their ability to induce adhesion in A549 epithelial cells and β-catenin activation and CXCL3 secretion in fibroblasts (NRK49-F cells). Subsequent inhibition of these responses by neutralising integrin antibodies was evaluated. A549 cells demonstrated adhesion to full-length WISP-1 whilst truncated proteins containing VWC, TSP or CT domains also induced adhesion, with highest activity observed with proteins containing the C-terminal TSP and CT domains. Likewise the ability to induce β-catenin activation and CXCL3 secretion was retained in truncations containing C-terminal domains. Pre-treatment of A549s with either integrin αVβ5, αVβ3 or β1 neutralising antibodies partially inhibited full length WISP-1 induced adhesion whilst combining integrin αVβ5 and β1 antibodies increased the potency of this effect. Incubation of NRK49-F cells with integrin neutralising antibodies failed to effect β-catenin translocation or CXCL3 secretion. Analysis of natural WISP-1 derived from human lung tissue showed the native protein is a high order oligomer. Our data suggest that WISP-1 mediated adhesion of A549 cells is an integrin-driven event regulated by the C-terminal domains of the protein. Activation of β-catenin signalling and CXCL3 secretion also resides within the C-terminal domains of WISP-1 but are not regulated by integrins. The oligomeric nature of native

  2. MAPK/ERK and Wnt/{beta}-Catenin pathways are synergistically involved in proliferation of Sca-1 positive hepatic progenitor cells

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Caixia [Department of Surgery, University of North Carolina at Chapel Hill (United States); Department of Medical Genetics and Cell Biology, Ningxia Medical University, Yinchuan 750004 (China); Samuelson, Lisa; Cui, Cai-Bin; Sun, Yangzhong [Department of Surgery, University of North Carolina at Chapel Hill (United States); Gerber, David A., E-mail: david_gerber@med.unc.edu [Department of Surgery, University of North Carolina at Chapel Hill (United States); Lineberger Cancer Center, University of North Carolina at Chapel Hill (United States)

    2011-06-17

    Highlights: {yields} Activation of MAPK/ERK pathway with epidermal growth factor (EGF) significantly increased Sca-1{sup +} HPC proliferation and colony formation. {yields} Activation of either IL-6/STAT3 or Wnt/{beta}-Catenin pathway did not independently support cell proliferation and colony formation of HPCs. {yields} Wnt/{beta}-Catenin pathway can cooperate with EGF to significantly promote HPC colony formation and maintain long-term HPCs in vitro. -- Abstract: Hepatic progenitor cells (HPCs) persist in adulthood and have the potential to play a major role in regenerating diseased liver. However, the signaling pathways that both directly and indirectly regulate HPCs' self-renewal and differentiation remain elusive. Previously, we identified a bipotent, stem cell antigen-1 (Sca-1) positive HPC population from naive adult liver tissue. In the present study, we aimed to investigate the involvement of various signaling pathways in Sca-1{sup +} HPC proliferation. Epidermal growth factor (EGF) supplementation shows a significant increase in Sca-1{sup +} HPC proliferation and colony formation while stimulating phosphorylation of ERK1/2 and activating the induction of Cyclin D1. There were no demonstrable effects of EGF on Akt. The MEK inhibitor, PD0325901, inhibits proliferation and ERK1/2 phosphorylation while also suppressing the expression of Cyclin D1. In addition, activation of either IL-6/STAT3 or Wnt/{beta}-Catenin pathway did not independently support cell proliferation and colony formation of HPCs. The Wnt/{beta}-Catenin pathway can cooperate with EGF to significantly promote HPC colony formation ratio and maintain long-term HPC in vitro. The data indicates that the MAPK/ERK pathway is both essential and critical for HPC proliferation, and the Wnt signaling pathway is not sufficient, while it works synergistically with the MAPK/ERK signaling pathway to promote HPC proliferation.

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

    Science.gov (United States)

    Katoh, Masuko; Katoh, Masaru

    2007-01-01

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

  4. [Wnt/β-catenin signal pathway mediated Salidroside induced directional differentiation from mouse mesenchymal stem cells to nerve cells].

    Science.gov (United States)

    Guo, Chao; Liu, Run; Zhao, Hong-Bin; Qin, Guan-Hua

    2015-03-01

    To explore the molecule mechanism of Salidroside inducing directional differentiation of mouse mesenchymal stem cells (MSCs) into neuronal cells. The mouse multipotent mesenchymal precursor cell line (D1) was taken as the objective. Cultured MSCs were divided into the negative control group (complete culture solution), the positive control group (containing 1 mmol/L β-mercaptoethanol), the Salidroside induced group (20 mg/L Salidroside), and the blocked group (20 ng/ ml DKK1, a special inhibitor of Wnt/β-catenin signal pathway). All cells were inoculated in a 6-well plate (1 x 10(4) cells/cm2) and grouped for 24 h. The expression of p-catenin was detected by fluorescence Immunochemistry in the negative control group, the positive control group, and the Salidroside induced group. The expression of neuron-specific enolase (NSE), beta 3 class III tubulin (β-tubulin III), nuclear receptor related factor 1 (Nurr1), glial fibrillary acidic protein (GFAP) mRNA, Wnt3a, β-catenin, low-density lipoprotein receptor-related protein6 (LRP6), Axin mRNA were detected using reverse transcrip- tion PCR (RT-PCR). The expression of β-catenin and NSE protein were analyzed by Western blot in the negative control group, the positive control group, and the Salidroside induced group. Ca2+ chelating agents (EGTA), L-type Ca2+ channel blocker (Nifedpine), and IP3Ks special inhibitor (LY294002) were used to block Ca2+ signal pathway respectively. The expression of Wnt3a, LRP-6, Axin, glycogen syn- thase kinase (GSK-3), and β-catenin mRNA were detected by RT-PCR. The β-catenin protein expression was analyzed using Western blot. Compared with the positive control group, β-catenin protein was strong positively expressed; the expression of Wnt3a, β-catenin, LRP6, Axin, NSE, β-tubulin III, Nurr1 mRNA, and NSE protein were obviously up-regulated in the Salidroside induced group (P < 0.01). Compared with the positive control group and the Salidroside induced group, β-catenin, NSE, Nurr1

  5. Curcumin Suppresses the Colon Cancer Proliferation by Inhibiting Wnt/β-Catenin Pathways via miR-130a

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    Huiqiang Dou

    2017-11-01

    Full Text Available Curcumin exhibits anti-tumor effects in several cancers, including colorectal carcinoma (CRC, but the detailed mechanisms are still unclear. Here we studied the mechanisms underlying the anti-tumor effect of curcumin in colon cancer cells. SW480 cells were injected into mice to establish the xenograft tumor model, followed by evaluation of survival rate with the treatment of curcumin. The expression levels of β-catenin, Axin and TCF4 were measured in the SW480 cells in the absence or presence of curcumin. Moreover, miRNAs related to the curcumin treatment were also detected in vitro. Curcumin could suppress the growth of colon cancer cells in the mouse model. This anti-tumor activity of curcumin was exerted by inhibiting cell proliferation rather than promoting cell apoptosis. Further study suggested that curcumin inhibited cell proliferation by suppressing the Wnt/β-catenin pathway. MiR-130a was down-regulated by curcumin treatment, and overexpressing miR-130a could abolish the anti-tumor activity of curcumin. Our study confirms that curcumin is able to inhibit colon cancer by suppressing the Wnt/β-catenin pathways via miR-130a. MiR-130a may serve as a new target of curcumin for CRC treatment.

  6. Regulatory effect of evodiamine on the malignant biological behaviors and Wnt/β-catenin signaling pathway of colorectal cancer cell lines HT29

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    Yuan-Hui Wang

    2016-04-01

    Full Text Available Objective: To study the regulatory effect of evodiamine on the malignant biological behaviors and Wnt/β-catenin signaling pathway of colorectal cancer cell lines HT29. Methods: Colorectal cancer cell lines HT29 were cultured and divided into blank control group and evodiamine group, and after different treatment, cell viability, proportion of different cell cycle as well as the contents of VEGFA, VEGFB, VEGFC, MMP3, MMP14, Wnt and β-catenin were detected. Results: (1 Cell viability: MTT value of evodiamine group was significantly lower than that of blank control group; (2 Cell cycle: proportion of both S phase and G2/M phase of evodiamine group were lower than those of blank control group, and proportion of G0/ G1 phase was higher than that of blank control group; (3 VEGF and MMP contents: VEGFA, VEGFB, VEGFC, MMP3 and MMP14 contents of evodiamine group were lower than those of blank control group; (4 Wnt/β-catenin signaling pathway: Wnt and β-catenin contents of evodiamine group were lower than those of blank control group. Conclusion: Evodiamine can inhibit the proliferation of colorectal cancer cell lines HT29 and down-regulate the expression of VEGF and MMP, and the effect may be achieved by inhibiting the activation of Wnt/β-catenin signaling pathway.

  7. Activation of the Wnt/{beta}-catenin signaling pathway is associated with glial proliferation in the adult spinal cord of ALS transgenic mice

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yanchun [Department of Histology and Embryology, Weifang Medical University, Weifang, Shandong (China); Department of Histology and Embryology, Shandong University School of Medicine, Jinan, Shandong (China); Guan, Yingjun, E-mail: guanyj@wfmc.edu.cn [Department of Histology and Embryology, Weifang Medical University, Weifang, Shandong (China); Department of Histology and Embryology, Shandong University School of Medicine, Jinan, Shandong (China); Liu, Huancai [Department of Orthopedic, Affiliated Hospital, Weifang Medical University, Weifang, Shandong (China); Wu, Xin; Yu, Li; Wang, Shanshan; Zhao, Chunyan; Du, Hongmei [Department of Histology and Embryology, Weifang Medical University, Weifang, Shandong (China); Wang, Xin, E-mail: xwang@rics.bwh.harvard.edu [Department of Neurosurgery, Brigham and Women' s Hospital, Harvard Medical School, Boston, MA (United States)

    2012-04-06

    Highlights: Black-Right-Pointing-Pointer Wnt3a and Cyclin D1 were upregulated in the spinal cord of the ALS mice. Black-Right-Pointing-Pointer {beta}-catenin translocated from the cell membrane to the nucleus in the ALS mice. Black-Right-Pointing-Pointer Wnt3a, {beta}-catenin and Cyclin D1 co-localized for astrocytes were all increased. Black-Right-Pointing-Pointer BrdU/Cyclin D1 double-positive cells were increased in the spinal cord of ALS mice. Black-Right-Pointing-Pointer BrdU/Cyclin D1/GFAP triple-positive cells were detected in the ALS mice. -- Abstract: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by the progressive and fatal loss of motor neurons. In ALS, there is a significant cell proliferation in response to neurodegeneration; however, the exact molecular mechanisms of cell proliferation and differentiation are unclear. The Wnt signaling pathway has been shown to be involved in neurodegenerative processes. Wnt3a, {beta}-catenin, and Cyclin D1 are three key signaling molecules of the Wnt/{beta}-catenin signaling pathway. We determined the expression of Wnt3a, {beta}-catenin, and Cyclin D1 in the adult spinal cord of SOD1{sup G93A} ALS transgenic mice at different stages by RT-PCR, Western blot, and immunofluorescence labeling techniques. We found that the mRNA and protein of Wnt3a and Cyclin D1 in the spinal cord of the ALS mice were upregulated compared to those in wild-type mice. In addition, {beta}-catenin translocated from the cell membrane to the nucleus and subsequently activated transcription of the target gene, Cyclin D1. BrdU and Cyclin D1 double-positive cells were increased in the spinal cord of these mice. Moreover, Wnt3a, {beta}-catenin, and Cyclin D1 were also expressed in both neurons and astrocytes. The expression of Wnt3a, {beta}-catenin or Cyclin D1 in mature GFAP{sup +} astrocytes increased. Moreover, BrdU/Cyclin D1/GFAP triple-positive cells were detected in the ALS mice. Our findings suggest that

  8. Tipping toward sustainability: emerging pathways of transformation.

    Science.gov (United States)

    Westley, Frances; Olsson, Per; Folke, Carl; Homer-Dixon, Thomas; Vredenburg, Harrie; Loorbach, Derk; Thompson, John; Nilsson, Måns; Lambin, Eric; Sendzimir, Jan; Banerjee, Banny; Galaz, Victor; van der Leeuw, Sander

    2011-11-01

    This article explores the links between agency, institutions, and innovation in navigating shifts and large-scale transformations toward global sustainability. Our central question is whether social and technical innovations can reverse the trends that are challenging critical thresholds and creating tipping points in the earth system, and if not, what conditions are necessary to escape the current lock-in. Large-scale transformations in information technology, nano- and biotechnology, and new energy systems have the potential to significantly improve our lives; but if, in framing them, our globalized society fails to consider the capacity of the biosphere, there is a risk that unsustainable development pathways may be reinforced. Current institutional arrangements, including the lack of incentives for the private sector to innovate for sustainability, and the lags inherent in the path dependent nature of innovation, contribute to lock-in, as does our incapacity to easily grasp the interactions implicit in complex problems, referred to here as the ingenuity gap. Nonetheless, promising social and technical innovations with potential to change unsustainable trajectories need to be nurtured and connected to broad institutional resources and responses. In parallel, institutional entrepreneurs can work to reduce the resilience of dominant institutional systems and position viable shadow alternatives and niche regimes.

  9. SphK1 inhibitor SKI II inhibits the proliferation of human hepatoma HepG2 cells via the Wnt5A/β-catenin signaling pathway.

    Science.gov (United States)

    Liu, Hong; Zhang, Cai-Xia; Ma, Yan; He, Hong-Wei; Wang, Jia-Ping; Shao, Rong-Guang

    2016-04-15

    Sphingosine 1-phosphate (S1P) promotes cell growth, proliferation and survival. Sphingosine kinase 1 (SphK1), which converts sphingosine to S1P, is a key promoter in cancer. We previously found that the SphK1 inhibitor II (SKI II), suppresses the cell growth and induces apoptosis in human hepatoma HepG2 cells. However, the precise regulatory mechanism and signaling pathway on SKI II inhibiting tumor growth remains unknown. The expressions of β-catenin and related molecules of Wnt/β-catenin signal were detected by western blot in HepG2 cells. And the mRNA expression of β-catenin was detected by RT-PCR. The Wnt5A gene was silenced by siRNA. The colony formation was determined by staining with crystal violet. And the cell growth was examined by SRB assay and BrdU assay. We found that SKI II decreased the expression of β-catenin and the downstream molecules of β-catenin signal pathway and promotes the β-catenin degradation. In addition, SKI II induced the expression of Wnt5A, and then triggered β-catenin degradation. Furthermore, silencing Wnt5A decreased the anti-tumor effects of SKI II through recovering the expressions of β-catenin and downstream molecules of β-catenin signal pathway. SKI II-induced downregulation of HepG2 cell proliferation was associated with Wnt signaling pathway through Wnt5A-mediated β-catenin degradation. Our study revealed that a novel signal pathway was involved in SKI II-inhibited cell proliferation in human hepatoma cells. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Wnt Signaling and Colorectal Cancer.

    Science.gov (United States)

    Schatoff, Emma M; Leach, Benjamin I; Dow, Lukas E

    2017-04-01

    The WNT signaling pathway is a critical mediator of tissue homeostasis and repair, and frequently co-opted during tumor development. Almost all colorectal cancers (CRC) demonstrate hyperactivation of the WNT pathway, which in many cases is believed to be the initiating and driving event. In this short review, we provide a focused overview of recent developments in our understanding of the WNT pathway in CRC, describe new research tools that are enabling a deeper understanding of WNT biology, and outline ongoing efforts to target this pathway therapeutically.

  11. Tumours with elevated levels of the Notch and Wnt pathways exhibit efficacy to PF-03084014, a γ-secretase inhibitor, in a preclinical colorectal explant model.

    Science.gov (United States)

    Arcaroli, J J; Quackenbush, K S; Purkey, A; Powell, R W; Pitts, T M; Bagby, S; Tan, A C; Cross, B; McPhillips, K; Song, E-K; Tai, W M; Winn, R A; Bikkavilli, K; Vanscoyk, M; Eckhardt, S G; Messersmith, W A

    2013-08-06

    Dysregulation of the Notch pathway has been identified to play an important role in the development and progression of colorectal cancer (CRC). In this study, we used a patient-derived CRC explant model to investigate the efficacy of the clinical γ-secretase inhibitor (GSI) PF-03084014. A total of 16 CRC explants were treated with PF-03084014. Knockdown of RBPjκ gene was used to determine the specificity of PF-03084014. Evaluation of the Notch and Wnt pathways in CRC explant tumours was performed by gene array and immunoblotting. We identified a subset of CRC tumours that exhibited elevations of the Notch and Wnt pathways sensitive to PF-03084014. Treatment with the GSI resulted in a significant reduction in cleaved Notch, Axin2 (Wnt-dependent gene) and active β-catenin. In addition, knockdown of the RBPjκ gene showed that PF-03084014 has specificity for the Notch pathway in an HCT116 cell line xenograft model. Finally, an increase in apoptosis was observed in CRC001- and CRC021-sensitive tumours. This study provides evidence that inhibition of γ-secretase may be beneficial in a subset of patients with elevated levels of the Wnt and Notch pathways.

  12. C-Jun N-terminal kinase (JNK mediates Wnt5a-induced cell motility dependent or independent of RhoA pathway in human dental papilla cells.

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    Chenglin Wang

    Full Text Available Wnt5a plays an essential role in tissue development by regulating cell migration, though the molecular mechanisms are still not fully understood. Our study investigated the pathways involved in Wnt5a-dependent cell motility during the formation of dentin and pulp. Over-expression of Wnt5a promoted cell adhesion and formation of focal adhesion complexes (FACs in human dental papilla cells (hDPCs, while inhibiting cell migration. Instead of activating the canonical Wnt signal pathway in hDPCs, Wnt5a stimulation induced activation of the JNK signal in a RhoA-dependent or independent manner. Inhibiting JNK abrogated Wnt5a-induced FACs formation but not cytoskeletal rearrangement. Both dominant negative RhoA (RhoA T19N and constitutively active RhoA mutants (RhoA Q63L blocked the Wnt5a-dependent changes in hDPCs adhesion, migration and cytoskeletal rearrangement here too, with the exception of the formation of FACs. Taken together, our study suggested that RhoA and JNK signaling have roles in mediating Wnt5a-dependent adhesion and migration in hDPCs, and the Wnt5a/JNK pathway acts both dependently and independently of the RhoA pathway.

  13. C-Jun N-Terminal Kinase (JNK) Mediates Wnt5a-Induced Cell Motility Dependent or Independent of RhoA Pathway in Human Dental Papilla Cells

    Science.gov (United States)

    Wang, Chenglin; Zhao, Yuan; Su, Yingying; Li, Ruimin; Lin, Yunfeng; Zhou, Xuedong; Ye, Ling

    2013-01-01

    Wnt5a plays an essential role in tissue development by regulating cell migration, though the molecular mechanisms are still not fully understood. Our study investigated the pathways involved in Wnt5a-dependent cell motility during the formation of dentin and pulp. Over-expression of Wnt5a promoted cell adhesion and formation of focal adhesion complexes (FACs) in human dental papilla cells (hDPCs), while inhibiting cell migration. Instead of activating the canonical Wnt signal pathway in hDPCs, Wnt5a stimulation induced activation of the JNK signal in a RhoA-dependent or independent manner. Inhibiting JNK abrogated Wnt5a-induced FACs formation but not cytoskeletal rearrangement. Both dominant negative RhoA (RhoA T19N) and constitutively active RhoA mutants (RhoA Q63L) blocked the Wnt5a-dependent changes in hDPCs adhesion, migration and cytoskeletal rearrangement here too, with the exception of the formation of FACs. Taken together, our study suggested that RhoA and JNK signaling have roles in mediating Wnt5a-dependent adhesion and migration in hDPCs, and the Wnt5a/JNK pathway acts both dependently and independently of the RhoA pathway. PMID:23844260

  14. ALDH1B1 Is Crucial for Colon Tumorigenesis by Modulating Wnt/β-Catenin, Notch and PI3K/Akt Signaling Pathways.

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    Surendra Singh

    Full Text Available In the normal human colon, aldehyde dehydrogenase 1B1 (ALDH1B1 is expressed only at the crypt base, along with stem cells. It is also highly expressed in the human colonic adenocarcinomas. This pattern of expression corresponds closely to that observed for Wnt/β-catenin signaling activity. The present study examines the role of ALDH1B1 in colon tumorigenesis and signalling pathways mediating its effects. In a 3-dimensional spheroid growth model and a nude mouse xenograft tumor model, shRNA-induced suppression of ALDH1B1 expression decreased the number and size of spheroids formed in vitro and the size of xenograft tumors formed in vivo by SW 480 cells. Six binding elements for Wnt/β-catenin signalling transcription factor binding elements (T-cell factor/lymphoid enhancing factor were identified in the human ALDH1B1 gene promoter (3 kb but shown by dual luciferase reporter assay to not be necessary for ALDH1B1 mRNA expression in colon adenocarcinoma cell lines. We examined Wnt-reporter activity and protein/mRNA expression for Wnt, Notch and PI3K/Akt signaling pathways. Wnt/β-catenin, Notch and PI3K/Akt-signaling pathways were down-regulated in SW 480 cells in which ALDH1B1 expression had been suppressed. In summary, our data demonstrate that ALDH1B1 may promote colon cancer tumorigenesis by modulating the Wnt/β-catenin, Notch and PI3K/Akt signaling pathways. Selective targeting of ALDH1B1 may represent a novel means to prevent or treat colon cancer.

  15. Gene expression profiling of peri-implant healing of PLGA-Li+ implants suggests an activated Wnt signaling pathway in vivo.

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    Anna Thorfve

    Full Text Available Bone development and regeneration is associated with the Wnt signaling pathway that, according to literature, can be modulated by lithium ions (Li+. The aim of this study was to evaluate the gene expression profile during peri-implant healing of poly(lactic-co-glycolic acid (PLGA implants with incorporated Li+, while PLGA without Li+ was used as control, and a special attention was then paid to the Wnt signaling pathway. The implants were inserted in rat tibia for 7 or 28 days and the gene expression profile was investigated using a genome-wide microarray analysis. The results were verified by qPCR and immunohistochemistry. Histomorphometry was used to evaluate the possible effect of Li+ on bone regeneration. The microarray analysis revealed a large number of significantly differentially regulated genes over time within the two implant groups. The Wnt signaling pathway was significantly affected by Li+, with approximately 34% of all Wnt-related markers regulated over time, compared to 22% for non-Li+ containing (control; Ctrl implants. Functional cluster analysis indicated skeletal system morphogenesis, cartilage development and condensation as related to Li+. The downstream Wnt target gene, FOSL1, and the extracellular protein-encoding gene, ASPN, were significantly upregulated by Li+ compared with Ctrl. The presence of β-catenin, FOSL1 and ASPN positive cells was confirmed around implants of both groups. Interestingly, a significantly reduced bone area was observed over time around both implant groups. The presence of periostin and calcitonin receptor-positive cells was observed at both time points. This study is to the best of the authors' knowledge the first report evaluating the effect of a local release of Li+ from PLGA at the fracture site. The present study shows that during the current time frame and with the present dose of Li+ in PLGA implants, Li+ is not an enhancer of early bone growth, although it affects the Wnt signaling pathway.

  16. Receptor tyrosine kinases activate canonical WNT/β-catenin signaling via MAP kinase/LRP6 pathway and direct β-catenin phosphorylation.

    Directory of Open Access Journals (Sweden)

    Pavel Krejci

    Full Text Available Receptor tyrosine kinase signaling cooperates with WNT/β-catenin signaling in regulating many biological processes, but the mechanisms of their interaction remain poorly defined. We describe a potent activation of WNT/β-catenin by FGFR2, FGFR3, EGFR and TRKA kinases, which is independent of the PI3K/AKT pathway. Instead, this phenotype depends on ERK MAP kinase-mediated phosphorylation of WNT co-receptor LRP6 at Ser1490 and Thr1572 during its Golgi network-based maturation process. This phosphorylation dramatically increases the cellular response to WNT. Moreover, FGFR2, FGFR3, EGFR and TRKA directly phosphorylate β-catenin at Tyr142, which is known to increase cytoplasmic β-catenin concentration via release of β-catenin from membranous cadherin complexes. We conclude that signaling via ERK/LRP6 pathway and direct β-catenin phosphorylation at Tyr142 represent two mechanisms used by various receptor tyrosine kinase systems to activate canonical WNT signaling.

  17. The mTOR and canonical Wnt signaling pathways mediate the mnemonic effects of progesterone in the dorsal hippocampus.

    Science.gov (United States)

    Fortress, Ashley M; Heisler, John D; Frick, Karyn M

    2015-05-01

    Although much is known about the neural mechanisms responsible for the mnemonic effects of 17β-estradiol (E2 ), very little is understood about the mechanisms through which progesterone (P4 ) regulates memory. We previously showed that intrahippocampal infusion of P4 in ovariectomized female mice enhances object recognition (OR) memory consolidation in a manner dependent on activation of dorsal hippocampal ERK and mTOR signaling. However, the role of specific progesterone receptors (PRs) in mediating the effects of progesterone on memory consolidation and hippocampal cell signaling are unknown. Therefore, the goals of this study were to investigate the roles of membrane-associated and intracellular PRs in mediating hippocampal memory consolidation, and identify downstream cell signaling pathways activated by PRs. Membrane-associated PRs were targeted using bovine serum albumin-conjugated progesterone (BSA-P), and intracellular PRs (PR-A, PR-B) were targeted using the intracellular PR agonist R5020. Immediately after OR training, ovariectomized mice received bilateral dorsal hippocampal infusion of vehicle, P4 , BSA-P, or R5020. OR memory consolidation was enhanced by P4 , BSA-P, and R5020. However, only P4 and BSA-P activated ERK and mTOR signaling. Furthermore, dorsal hippocampal infusion of the ERK inhibitor U0126 blocked the memory-enhancing effects of BSA-P, but not R5020. The intracellular PR antagonist RU486 blocked the memory-enhancing effects of R5020, but not BSA-P. Interestingly, P4 robustly activated canonical Wnt signaling in the dorsal hippocampus, which is consistent with our recent findings that canonical Wnt signaling is necessary for OR memory consolidation. R5020, but not BSA-P, also elicited a modest increase in canonical Wnt signaling. Collectively, these data suggest that activation of ERK signaling is necessary for membrane-associated PRs to enhance OR, and indicate a role for canonical Wnt signaling in the memory-enhancing effects of

  18. WNT1 inducible signaling pathway protein 3, WISP-3, a novel target gene in colorectal carcinomas with microsatellite instability.

    Science.gov (United States)

    Thorstensen, L; Diep, C B; Meling, G I; Aagesen, T H; Ahrens, C H; Rognum, T O; Lothe, R A

    2001-12-01

    Microsatellite instability (MSI) is the phenotype of colorectal carcinomas with defect mismatch repair. Genes with repetitive sequences within their coding regions are targets for mutations in these tumors. We have evaluated 2 novel candidate genes for potential involvement in development of MSI colorectal carcinomas and compared them with alterations in known target genes. The MSI status was determined by multiplex polymerase chain reactions (PCRs) of 5-17 markers in a Norwegian series of 275 colorectal carcinomas. All MSI tumors were analyzed for gene mutations using fluorescence PCR followed by capillary electrophoresis. Two novel candidate genes, WNT1-inducible signaling pathway protein 3 (WISP-3) and caspase-1, and 9 known target genes were analyzed. Thirteen percent of the tumors were MSI-high (H) and 12% were MSI-low (L). Thirty-three of 37 MSI-H vs. 1 of 34 MSI-L tumors showed mutations in the target genes (P WISP-3 was mutated in 31% of the MSI-H tumors. The frequencies of frameshift mutations in the known target genes were comparable with other studies. The relative high frequency of mutation, higher than those seen for other known target genes, the predicted truncation of the protein product, and the homology with WISP-1 and WISP-2, 2 proteins induced downstream of WNT1 signaling, strongly suggest WISP-3 as a novel target in development of MSI-H colorectal carcinomas.

  19. EZH2 mediates ATO-induced apoptosis in acute myeloid leukemia cell lines through the Wnt signaling pathway.

    Science.gov (United States)

    Zhang, Hao; Gu, Huizi; Li, Limei; Ren, Yuan; Zhang, Lijun

    2016-05-01

    In this study, we examined the mechanisms associated with EZH2 mediation of apoptosis and chemoresistance to arsenic trioxide (ATO) in acute myeloid leukemia (AML) cell lines through the Wnt/β-catenin signaling pathway. The induction of spontaneous apoptosis observed in multiple EZH2-silenced leukemic cell lines was assessed by flow cytometry, and levels of Wnt/β-catenin-related expression were determined by western blot analysis. In comparison with AML control cells, EZH2-knockdown cells exhibited increased apoptosis and significant downregulation of β-catenin expression, as well as decreases in GSK-3β phosphorylation and β-catenin activation (p EZH2 knockdown sensitized AML cells to induced cell death following administration of chemotherapeutic ATO. Our results suggested that EZH2 in leukemic cell lines might inhibit ATO-induced apoptosis and that EZH2 may be a potential therapeutic target in AML patients undergoing ATO treatment. Our findings provide new insights into the role of ATO and EZH2 in regulating AML progression.

  20. microRNAs regulate β-catenin of the Wnt signaling pathway in early sea urchin development.

    Science.gov (United States)

    Stepicheva, Nadezda; Nigam, Priya A; Siddam, Archana D; Peng, Chieh Fu; Song, Jia L

    2015-06-01

    Development of complex multicellular organisms requires careful regulation at both transcriptional and post-transcriptional levels. Post-transcriptional gene regulation is in part mediated by a class of non-coding RNAs of 21-25 nucleotides in length known as microRNAs (miRNAs). β-catenin, regulated by the canonical Wnt signaling pathway, has a highly evolutionarily conserved function in patterning early metazoan embryos, in forming the Anterior-Posterior axis, and in establishing the endomesoderm. Using reporter constructs and site-directed mutagenesis, we identified at least three miRNA binding sites within the 3' untranslated region (3'UTR) of the sea urchin β-catenin. Further, blocking these three miRNA binding sites within the β-catenin 3'UTR to prevent regulation of endogenous β-catenin by miRNAs resulted in a minor increase in β-catenin protein accumulation that is sufficient to induce aberrant gut morphology and circumesophageal musculature. These phenotypes are likely the result of increased transcript levels of Wnt responsive endomesodermal regulatory genes. This study demonstrates the importance of miRNA regulation of β-catenin in early development. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. β-elemene attenuates macrophage activation and proinflammatory factor production via crosstalk with Wnt/β-catenin signaling pathway.

    Science.gov (United States)

    Fang, Yangyi; Kang, Yanhua; Zou, Han; Cheng, Xiaxuan; Xie, Tian; Shi, Liyun; Zhang, Hang

    2018-01-01

    β-elemene, extracted from Rhizoma zedoariae, has been widely used as a traditional medicine for its antitumor activity against a broad range of cancers. However, the effect of β-elemene in inflammation disorders has yet to be determined. The present study was designed to investigate the anti-inflammatory effects and potential molecular mechanisms of β-elemene in lipopolysaccharide (LPS)-induced murine macrophage cells RAW264.7. We found that the production of pro-inflammatory mediators, including interleukin-6(IL-6), tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), induced by LPS was significantly suppressed by β-elemene in a dose-dependent manner in RAW264.7 macrophage cell line. Also, β-elemene inhibited LPS-induced nitric oxide synthase (iNOS) and interleukin-10 (IL-10) expression by RAW264.7, which was related to the down-regulation of Wnt/β-catenin signaling pathway. Importantly, this study demonstrates that β-catenin was significantly inhibited by β-elemene, which appeared to be largely responsible for the down-regulation of Wnt/β-catenin signaling pathway. Accordingly, the deletion of β-catenin in primary macrophages reversed β-catenin-elicited inhibition of immune response. Furthermore, β-catenin expression and Wnt/β-catenin signaling pathway induced by LPS in RAW264.7 was also significantly inhibited by α-humulene, one isomeric sesquiterpene of β-elemene. α-humulene was also found to significantly inhibit LPS-induced production of proinflammatory cytokines. However, α-humulene showed more cytotoxic ability than β-elemene. Collectively, our data illustrated that β-elemene exerted a potent inhibitory effect on pro-inflammatory meditator and cytokines production via the inactivation of β-catenin, and also demonstrated the protective functions of β-elemene in endotoxin-induced inflammation. β-elemene may serve as potential nontoxic modulatory agents for the prevention and treatment of inflammatory diseases. Copyright

  2. Differential Expression of Wnt Pathway Genes in Sporadic Hepatocellular Carcinomas Infected With Hepatitis B Virus Identified With OligoGE Arrays.

    Science.gov (United States)

    Lin, Xiaoyan; Wang, Qiangxiu; Cao, Zhixin; Geng, Ming; Cao, Yongcheng; Liu, Xiaohong

    2013-01-01

    Epidemiological evidence has clearly indicated that chronic infection with the hepatitis B virus (HBV) is the major risk factor for developing hepatocellular carcinoma (HCC). Nonetheless, the mechanisms by which HBV contributes to the pathogenesis of HCC have not been fully elucidated. Our aim was to characterize differential gene expression profiles related to the Wnt signaling pathway between primary tumor and adjacent normal tissues in HCC patients with concomitant HBVinfection . An oligoGEArray® (an oligonucleotide-based gene expression array platform) containing 126 Wnt signaling pathway-related genes was used to compare gene expressions between primary HCC and adjacent non-tumorous liver tissues from 10 patients with HCC. Selected differential genes were identified with real-time RT-PCR and immunohistochemistry (IHC). In particular, the protein of the differential gene DVL3 (disheveled, dsh homolog 3 [Drosophila]) was chosen to investigate whether it is up regulated in primary tumor correlated with the clinic pathological characteristics of HCC patients. For this purpose we examined 56 HCC tissue samples via IHC for the presence of DVL3 protein. Sixteen genes were identified with significant differential expression between HCC and adjacent non-tumorous liver tissue. These genes have been previously associated with the Frizzled signaling pathway, cell cycle, transcription, or protein degradation. All (100%) of the tumor samples results from 56 HCC patients tested were positive for DVL3 via IHC. Based on the intensity of DVL3 immunoreactivity, 25 (44.6%) and 31 (55.4%) of the patients were classified aslow and high-DVL3, respectively, which correlated with tumor stage (P = 0.029). This study clarified a number of Wnt pathway-related genes which are dysregulated in HBV-associated HCC. These genes may be contributedto the frequent activation of the Wnt signaling pathway. Our results promote the role of the Wnt signaling pathway in HBV-associated HCC.

  3. Effect of Huayu Tongluo Herbs on Reduction of Proteinuria via Inhibition of Wnt/β-Catenin Signaling Pathway in Diabetic Rats

    Directory of Open Access Journals (Sweden)

    Lu Bai

    2017-01-01

    Full Text Available The study investigated the expression of Wnt/β-catenin pathway in diabetic rats and the intervention effect of Huayu Tongluo herbs (HTH. Ten rats were randomly selected as control group and the remaining rats were established as diabetic models. The diabetic rats were randomly divided into model group and HTH treatment group. The intervention was intragastric administration in all rats for 20 weeks. At the end of every 4 weeks, fasting blood glucose and 24 h urinary total protein quantitatively were measured. At the end of the 20th week, biochemical parameters and body weight were tested. The kidney tissues were observed under light microscope and transmission electron microscopy. We examined Wnt/beta-catenin signaling pathway key proteins and renal interstitial fibrosis related molecular markers expression. The results showed that HTH could reduce urinary protein excretion and relieve renal pathological damage. Wnt4, p-GSK3β (S9, and β-catenin expression were decreased in the signaling pathway, but GSK3β level was not changed by HTH in diabetic rats. Furthermore, the expressions of TGF-β1 and ILK were decreased, but the level of E-cadherin was increased in diabetic rats after treatment with HTH. This study demonstrated that HTH could inhibit the high expression of Wnt/β-catenin pathway in kidney of diabetic rats. The effect might be one of the main ways to reduce urinary protein excretion.

  4. Hovenia dulcis Thunb extract and its ingredient methyl vanillate activate Wnt/β-catenin pathway and increase bone mass in growing or ovariectomized mice.

    Directory of Open Access Journals (Sweden)

    Pu-Hyeon Cha

    Full Text Available The Wnt/β-catenin pathway is a potential target for development of anabolic agents to treat osteoporosis because of its role in osteoblast differentiation and bone formation. However, there is no clinically available anti-osteoporosis drug that targets this Wnt/β-catenin pathway. In this study, we screened a library of aqueous extracts of 350 plants and identified Hovenia dulcis Thunb (HDT extract as a Wnt/β-catenin pathway activator. HDT extract induced osteogenic differentiation of calvarial osteoblasts without cytotoxicity. In addition, HDT extract increased femoral bone mass without inducing significant weight changes in normal mice. In addition, thickness and area of femoral cortical bone were also significantly increased by the HDT extract. Methyl vanillate (MV, one of the ingredients in HDT, also activated the Wnt/β-catenin pathway and induced osteoblast differentiation in vitro. MV rescued trabecular or cortical femoral bone loss in the ovariectomized mice without inducing any significant weight changes or abnormality in liver tissue when administrated orally. Thus, natural HDT extract and its ingredient MV are potential anabolic agents for treating osteoporosis.

  5. WNT16 antagonises excessive canonical WNT activation and protects cartilage in osteoarthritis.

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    Nalesso, Giovanna; Thomas, Bethan Lynne; Sherwood, Joanna Claire; Yu, Jing; Addimanda, Olga; Eldridge, Suzanne Elizabeth; Thorup, Anne-Sophie; Dale, Leslie; Schett, Georg; Zwerina, Jochen; Eltawil, Noha; Pitzalis, Costantino; Dell'Accio, Francesco

    2017-01-01

    Both excessive and insufficient activation of WNT signalling results in cartilage breakdown and osteoarthritis. WNT16 is upregulated in the articular cartilage following injury and in osteoarthritis. Here, we investigate the function of WNT16 in osteoarthritis and the downstream molecular mechanisms. Osteoarthritis was induced by destabilisation of the medial meniscus in wild-type and WNT16-deficient mice. Molecular mechanisms and downstream effects were studied in vitro and in vivo in primary cartilage progenitor cells and primary chondrocytes. The pathway downstream of WNT16 was studied in primary chondrocytes and using the axis duplication assay in Xenopus. WNT16-deficient mice developed more severe osteoarthritis with reduced expression of lubricin and increased chondrocyte apoptosis. WNT16 supported the phenotype of cartilage superficial-zone progenitor cells and lubricin expression. Increased osteoarthritis in WNT16-deficient mice was associated with excessive activation of canonical WNT signalling. In vitro, high doses of WNT16 weakly activated canonical WNT signalling, but, in co-stimulation experiments, WNT16 reduced the capacity of WNT3a to activate the canonical WNT pathway. In vivo, WNT16 rescued the WNT8-induced primary axis duplication in Xenopus embryos. In osteoarthritis, WNT16 maintains a balanced canonical WNT signalling and prevents detrimental excessive activation, thereby supporting the homeostasis of progenitor cells. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  6. Ectopic activation of the canonical wnt signaling pathway affects ectodermal patterning along the primary axis during larval development in the anthozoan Nematostella vectensis.

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    Marlow, Heather; Matus, David Q; Martindale, Mark Q

    2013-08-15

    The primary axis of cnidarians runs from the oral pole to the apical tuft and defines the major body axis of both the planula larva and adult polyp. In the anthozoan cnidarian Nematostella vectensis, the primary oral-aboral (O-Ab) axis first develops during the early embryonic stage. Here, we present evidence that pharmaceutical activators of canonical wnt signaling affect molecular patterning along the primary axis of Nematostella. Although not overtly morphologically complex, molecular investigations in Nematostella reveal that the O-Ab axis is demarcated by the expression of differentially localized signaling molecules and transcription factors that may serve roles in establishing distinct ectodermal domains. We have further characterized the larval epithelium by determining the position of a nested set of molecular boundaries, utilizing several newly characterized as well as previously reported epithelial markers along the primary axis. We have assayed shifts in their position in control embryos and in embryos treated with the pharmacological agents alsterpaullone and azakenpaullone, Gsk3β inhibitors that act as canonical wnt agonists, and the Wnt antagonist iCRT14, following gastrulation. Agonist drug treatments result in an absence of aboral markers, a shift in the expression boundaries of oral markers toward the aboral pole, and changes in the position of differentially localized populations of neurons in a dose-dependent manner, while antagonist treatment had the opposite effect. These experiments are consistent with canonical wnt signaling playing a role in an orally localized wnt signaling center. These findings suggest that in Nematostella, wnt signaling mediates O-Ab ectodermal patterning across a surprisingly complex epithelium in planula stages following gastrulation in addition to previously described roles for the wnt signaling pathway in endomesoderm specification during gastrulation and overall animal-vegetal patterning at earlier stages of

  7. High variability of expression profiles of homeologous genes for Wnt, Hh, Notch, and Hippo signaling pathways in Xenopus laevis.

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    Michiue, Tatsuo; Yamamoto, Takayoshi; Yasuoka, Yuuri; Goto, Toshiyasu; Ikeda, Takafumi; Nagura, Kei; Nakayama, Takuya; Taira, Masanori; Kinoshita, Tsutomu

    2017-06-15

    Cell signaling pathways, such as Wnt, Hedgehog (Hh), Notch, and Hippo, are essential for embryogenesis, organogenesis, and tissue homeostasis. In this study, we analyzed 415 genes involved in these pathways in the allotetraploid frog, Xenopus laevis. Most genes are retained in two subgenomes called L and S (193 homeologous gene pairs and 29 singletons). This conservation rate of homeologs is much higher than that of all genes in the X. laevis genome (86.9% vs 60.2%). Among singletons, 24 genes are retained in the L subgenome, a rate similar to the average for all genes (82.8% vs 74.6%). In addition, as general components of signal transduction, we also analyzed 32 heparan sulfate proteoglycan (HSPG)-related genes and eight TLE/Groucho transcriptional corepressors-related genes. In these gene sets, all homeologous pairs have been retained. Transcriptome analysis using RNA-seq data from developmental stages and adult tissues demonstrated that most homeologous pairs of signaling components have variable expression patterns, in contrast to the conservative expression profiles of homeologs for transcription factors. Our results indicate that homeologous gene pairs for cell signaling regulation have tended to become subfunctionalized after allotetraploidization. Diversification of signaling pathways by subfunctionalization of homeologs may enhance environmental adaptability. These results provide insights into the evolution of signaling pathways after polyploidization. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. MicroRNA-340 inhibits the migration, invasion, and metastasis of breast cancer cells by targeting Wnt pathway.

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    Mohammadi-Yeganeh, Samira; Paryan, Mahdi; Arefian, Ehsan; Vasei, Mohammad; Ghanbarian, Hossein; Mahdian, Reza; Karimipoor, Morteza; Soleimani, Masoud

    2016-07-01

    MicroRNAs (miRNAs) play a key role in tumor metastasis based on their capacity to regulate the expression of tumor-related genes. Over-expression of key genes such as c-MYC and CTNNB1 (encoding β-catenin) in Wnt/β-catenin-dependent and ROCK1 in Wnt/β-catenin-independent signaling pathways (Rho/Rho-associated kinase (ROCK) signaling pathway) has already been identified as the hallmarks of many tumors, and their role in breast cancer has also been investigated and confirmed. miR-340 characterization as an onco-suppressor miRNA has been previously reported. However, the mechanism by which it inhibits metastasis has not been completely elucidated. Quantitative real-time PCR (qPCR), Western blot, and luciferase assays were used to confirm the effect of miR-340 on the 3'-untranslated region (UTR) of the target genes. Lentiviral particles containing miR-340 were also used to evaluate the effect of miR-340 restoration on cell proliferation, migration, and invasion in vitro in the invasive MDA-MB-231 cell line. By applying bioinformatic approaches for the prediction of miRNAs targeting 3'-UTRs of CTNNB1, c-MYC, and ROCK1, we found out that miR-340 could dramatically down-regulate metastasis by targeting Wnt signaling in breast cancer cells. In the current study, analyzing miR-340 by reverse transcription quantitative PCR (RT-qPCR) in MDA-MB-231 showed that it was remarkably down-regulated in the metastatic breast cancer cell line. We found that restoration of miR-340 in the invasive breast cancer cell line, MDA-MB-231, suppresses the expression of the target genes' messenger RNA (mRNA) and protein and, as a result, inhibits tumor cell invasion and metastasis. Our findings highlight the ability of bioinformatic approaches to find miRNAs targeting specific genes. By bioinformatic analysis, we confirmed the important role of miR-340 as a pivotal regulator of breast cancer metastasis in targeting previously validated (ROCK1) and potentially novel genes, i.e., (CTNNB1 and c-MYC).

  9. Hydrostatic Pressure Regulates MicroRNA Expression Levels in Osteoarthritic Chondrocyte Cultures via the Wnt/β-Catenin Pathway

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    Sara Cheleschi

    2017-01-01

    Full Text Available Mechanical loading and hydrostatic pressure (HP regulate chondrocytes’ metabolism; however, how mechanical stimulation acts remain unclear. MicroRNAs (miRNAs play an important role in cartilage homeostasis, mechanotransduction, and in the pathogenesis of osteoarthritis (OA. This study investigated the effects of a cyclic HP (1–5 MPa, in both normal and OA human chondrocytes, on the expression of miR-27a/b, miR-140, miR-146a/b, and miR-365, and of their target genes (MMP-13, ADAMTS-5, IGFBP-5, and HDAC-4. Furthermore, we assessed the possible involvement of Wnt/β-catenin pathway in response to HP. Chondrocytes were exposed to HP for 3h and the evaluations were performed immediately after pressurization, and following 12, 24, and 48 h. Total RNA was extracted and used for real-time PCR. β-catenin was detected by Western blotting analysis and immunofluorescence. In OA chondrocytes, HP induced a significant increase (p < 0.01 of the expression levels of miR-27a/b, miR-140, and miR-146a, and a significant reduction (p < 0.01 of miR-365 at all analyzed time points. MMP-13, ADAMTS-5, and HDAC-4 were significantly downregulated following HP, while no significant modification was found for IGFBP-5. β-catenin levels were significantly increased (p < 0.001 in OA chondrocytes at basal conditions and significantly reduced (p < 0.01 by HP. Pressurization did not cause any significant modification in normal cells. In conclusion, in OA chondrocytes, HP restores the expression levels of some miRNAs, downregulates MMP-13, ADAMTS-5, and HDAC-4, and modulates the Wnt/β-catenin pathway activation.

  10. Shizukaol D, a Dimeric Sesquiterpene Isolated from Chloranthus serratus, Represses the Growth of Human Liver Cancer Cells by Modulating Wnt Signalling Pathway.

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    Lisha Tang

    Full Text Available Natural products have become sources of developing new drugs for the treatment of cancer. To seek candidate compounds that inhibit the growth of liver cancer, components of Chloranthus serratus were tested. Here, we report that shizukaol D, a dimeric sesquiterpene from Chloranthus serratus, exerted a growth inhibition effect on liver cancer cells in a dose- and time-dependent manner. We demonstrated that shizukaol D induced cells to undergo apoptosis. More importantly, shizukaol D attenuated Wnt signalling and reduced the expression of endogenous Wnt target genes, which resulted in decreased expression of β-catenin. Collectively, this study demonstrated that shizukaol D inhibited the growth of liver cancer cells by modulating Wnt pathway.

  11. Increased mRNA Levels of TCF7L2 and MYC of the Wnt Pathway in Tg-ArcSwe Mice and Alzheimer's Disease Brain

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    Elin S. Blom

    2011-01-01

    Full Text Available Several components in the Wnt pathway, including β-catenin and glycogen synthase kinase 3 beta, have been implied in AD pathogenesis. Here, mRNA brain levels from five-month-old tg-ArcSwe and nontransgenic mice were compared using Affymetrix microarray analysis. With surprisingly small overall changes, Wnt signaling was the most affected pathway with altered expression of nine genes in tg-ArcSwe mice. When analyzing mRNA levels of these genes in human brain, transcription factor 7-like 2 (TCF7L2 and v-myc myelocytomatosis viral oncogene homolog (MYC, were increased in Alzheimer's disease (AD (P<.05. Furthermore, no clear differences in TCF7L2 and MYC mRNA were found in brains with frontotemporal lobar degeneration, suggesting that altered regulation of these Wnt-related genes could be specific to AD. Finally, mRNA levels of three neurogenesis markers were analyzed. Increased mRNA levels of dihydropyrimidinase-like 3 were observed in AD brain, suggesting that altered Wnt pathway regulation may signify synaptic rearrangement or neurogenesis.

  12. Stimulation of Wnt/ß-catenin pathway in human CD8+ T lymphocytes from blood and lung tumors leads to a shared young/memory phenotype.

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    Marie-Andrée Forget

    Full Text Available Cancer can be treated by adoptive cell transfer (ACT of T lymphocytes. However, how to optimally raise human T cells to a differentiation state allowing the best persistence in ACT is a challenge. It is possible to differentiate mouse CD8(+ T cells towards stem cell-like memory (T(SCM phenotype upon TCR stimulation with Wnt/ß-catenin pathway activation. Here, we evaluated if T(SCM can be obtained from human mature CD8(+ T cells following TCR and Wnt/ß-catenin activation through treatment with the chemical agent 4,6-disubstituted pyrrolopyrimidine (TWS119, which inhibits the glycogen synthase kinase-3β (GSK-3β, key inhibitor of the Wnt pathway. Human CD8(+ T cells isolated from peripheral blood or tumor-infiltrating lymphocytes (TIL, and treated with TWS119 gave rise to CD62L(+CD45RA(+ cells, indicative of early differentiated stage, also expressing CD127 which is normally found on memory cells, and CD133, an hematopoietic stem cell marker. T(SCM cells raised from either TIL or blood secreted numerous inflammatory mediators, but in lower amounts than those measured without TWS119. Finally, generated T(SCM CD8(+ T cells expressed elevated Bcl-2 and no detectable caspase-3 activity, suggesting increased persistence. Our data support a role for Wnt/ß-catenin pathway in promoting the T(SCM subset in human CD8(+ T cells from TIL and the periphery, which are relevant for ACT.

  13. Cadherin-bound beta-catenin feeds into the Wnt pathway upon adherens junctions dissociation: evidence for an intersection between beta-catenin pools.

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    Yoonseok Kam

    Full Text Available Beta-catenin is an essential component of two cellular systems: cadherin-based adherens junctions (AJ and the Wnt signaling pathway. A functional or physical connection between these beta-catenin pools has been suggested in previous studies, but not conclusively demonstrated to date. To further examine this intersection, we treated A431 cell colonies with lysophosphatidic acid (LPA, which forces rapid and synchronized dissociation of AJ. A combination of immunostaining, time-lapse microscopy using photoactivatable-GFP-tagged beta-catenin, and image analyses indicate that the cadherin-bound pool of beta-catenin, internalized together with E-cadherin, accumulates at the perinuclear endocytic recycling compartment (ERC upon AJ dissociation, and can be translocated into the cell nucleus upon Wnt pathway activation. These results suggest that the ERC may be a site of residence for beta-catenin destined to enter the nucleus, and that dissociation of AJ may influence beta-catenin levels in the ERC, effectively affecting beta-catenin substrate levels available downstream for the Wnt pathway. This intersection provides a mechanism for integrating cell-cell adhesion with Wnt signaling and could be critical in developmental and cancer processes that rely on beta-catenin-dependent gene expression.

  14. Cadherin-Bound β-Catenin Feeds into the Wnt Pathway upon Adherens Junctions Dissociation: Evidence for an Intersection between β-Catenin Pools

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    Kam, Yoonseok; Quaranta, Vito

    2009-01-01

    β-catenin is an essential component of two cellular systems: cadherin-based adherens junctions (AJ) and the Wnt signaling pathway. A functional or physical connection between these β-catenin pools has been suggested in previous studies, but not conclusively demonstrated to date. To further examine this intersection, we treated A431 cell colonies with lysophosphatidic acid (LPA), which forces rapid and synchronized dissociation of AJ. A combination of immunostaining, time-lapse microscopy using photoactivatable-GFP-tagged β-catenin, and image analyses indicate that the cadherin-bound pool of β-catenin, internalized together with E-cadherin, accumulates at the perinuclear endocytic recycling compartment (ERC) upon AJ dissociation, and can be translocated into the cell nucleus upon Wnt pathway activation. These results suggest that the ERC may be a site of residence for β-catenin destined to enter the nucleus, and that dissociation of AJ may influence β-catenin levels in the ERC, effectively affecting β-catenin substrate levels available downstream for the Wnt pathway. This intersection provides a mechanism for integrating cell-cell adhesion with Wnt signaling and could be critical in developmental and cancer processes that rely on β-catenin-dependent gene expression. PMID:19238201

  15. Atrial Natriuretic Peptide Acts as a Neuroprotective Agent in in Vitro Models of Parkinson’s Disease via Up-regulation of the Wnt/β-Catenin Pathway

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    Colini Baldeschi, Arianna; Pittaluga, Eugenia; Andreola, Federica; Rossi, Simona; Cozzolino, Mauro; Nicotera, Giuseppe; Sferrazza, Gianluca; Pierimarchi, Pasquale; Serafino, Annalucia

    2018-01-01

    In the last decades increasing evidence indicated a crucial role of the Wnt/β-catenin signaling in development of midbrain dopaminergic (mDA) neurons. Recently dysregulation of this pathway has been proposed as a novel pathomechanism leading to Parkinson’s disease (PD) and some of the molecules participating to the signaling have been evaluated as potential therapeutic targets for PD. Atrial natriuretic peptide (ANP) is a cardiac-derived hormone having a critical role in cardiovascular homeostasis. ANP and its receptors (NPRs) are widely expressed in mammalian central nervous system (CNS) where they could be implicated in the regulation of neural development, synaptic transmission and information processing, as well as in neuroprotection. Until now, the effects of ANP in the CNS have been mainly ascribed to the binding and activation of NPRs. We have previously demonstrated that ANP affects the Wnt/β-catenin signaling in colorectal cancer cells through a Frizzled receptor-mediated mechanism. The purpose of this study was to investigate if ANP is able to exert neuroprotective effect on two in vitro models of PD, and if this effect could be related to activation of the Wnt/β-catenin signaling. As cellular models of DA neurons, we used the proliferating or RA-differentiated human neuroblastoma cell line SH-SY5Y. In both DA neuron-like cultures, ANP is able to positively affect the Wnt/β-catenin signaling, by inducing β-catenin stabilization and nuclear translocation. Importantly, activation of the Wnt pathway by ANP exerts neuroprotective effect when these two cellular systems were subjected to neurotoxic insult (6-OHDA) for mimicking the neurodegeneration of PD. Our data support the relevance of exogenous ANP as an innovative therapeutic molecule for midbrain, and more in general for brain diseases for which aberrant Wnt signaling seems to be involved. PMID:29449807

  16. ROLE OF PI3K-AKT-mTOR AND Wnt SIGNALING PATHWAYS IN G1-S TRANSITION OF CELL CYCLE IN CANCER CELLS

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    LAKSHMIPATHI eVADLAKONDA

    2013-04-01

    Full Text Available The PI3K–Akt pathway together with one of its downstream targets, the mechanistic target of rapamycin (mTOR is a highly deregulated pathway in cancers. There is a reciprocal relation between the Akt phosphorylation and mTOR complexes. Akt phosphorylated at T308 activates mTORC1 by inhibition of the tuberous sclerosis complex (TSC1/2, where as mTORC2 is recognized as the kinase that phosphorylates Akt at S473. Recent developments in the research on regulatory mechanisms of autophagy places mTORC1 mediated inhibition of autophagy at the central position in activation of proliferation and survival pathways in cells. Autophagy is a negative regulator of Wnt signaling pathway and the downstream effectors of Wnt signaling pathway, cyclin D1 and the c-Myc, are the key players in initiation of cell cycle and regulation of the G1-S transition in cancer cells. Production of reaction oxygen species (ROS, a common feature of a cancer cell metabolism, activates several downstream targets like the transcription factors FoxO, which play key roles in promoting the progression of cell cycle. A model is presented on the role of PI3K -Akt - mTOR and Wnt pathways in regulation of the progression of cell cycle through Go-G1-and S phases.

  17. 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.

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

    2016-04-08

    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. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  18. ENU mutagenesis reveals that Notchless homolog 1 (Drosophila affects Cdkn1a and several members of the Wnt pathway during murine pre-implantation development

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    Lossie Amy C

    2012-12-01

    Full Text Available Abstract Background Our interests lie in determining the genes and genetic pathways that are important for establishing and maintaining maternal-fetal interactions during pregnancy. Mutation analysis targeted to a 34 Mb domain flanked by Trp53 and Wnt3 demonstrates that this region of mouse chromosome 11 contains a large number of essential genes. Two mutant alleles (l11Jus1 and l11Jus4, which fall into the same complementation group, survive through implantation but fail prior to gastrulation. Results Through a positional cloning strategy, we discovered that these homozygous mutant alleles contain non-conservative missense mutations in the Notchless homolog 1 (Drosophila (Nle1 gene. NLE1 is a member of the large WD40-repeat protein family, and is thought to signal via the canonical NOTCH pathway in vertebrates. However, the phenotype of the Nle1 mutant mice is much more severe than single Notch receptor mutations or even in animals in which NOTCH signaling is blocked. To test the hypothesis that NLE1 functions in multiple signaling pathways during pre-implantation development, we examined expression of multiple Notch downstream target genes, as well as select members of the Wnt pathway in wild-type and mutant embryos. We did not detect altered expression of any primary members of the Notch pathway or in Notch downstream target genes. However, our data reveal that Cdkn1a, a NOTCH target, was upregulated in Nle1 mutants, while several members of the Wnt pathway are downregulated. In addition, we found that Nle1 mutant embryos undergo caspase-mediated apoptosis as hatched blastocysts, but not as morulae or blastocysts. Conclusions Taken together, these results uncover potential novel functions for NLE1 in the WNT and CDKN1A pathways during embryonic development in mammals.

  19. Osteoporosis and obesity: Role of Wnt pathway in human and murine models.

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    Colaianni, Graziana; Brunetti, Giacomina; Faienza, Maria Felicia; Colucci, Silvia; Grano, Maria

    2014-07-18

    Studies concerning the pathophysiological connection between obesity and osteoporosis are currently an intriguing area of research. Although the onset of these two diseases can occur in a different way, recent studies have shown that obesity and osteoporosis share common genetic and environmental factors. Despite being a risk factor for health, obesity has traditionally been considered positive to bone because of beneficial effect of mechanical loading, exerted by high body mass, on bone formation. However, contrasting studies have not achieved a clear consensus, suggesting instead that excessive fat mass derived from obesity condition may not protect against osteoporosis or, even worse, could be rather detrimental to bone. On the other hand, it is hitherto better established that, since adipocytes and osteoblasts are derived from a common mesenchymal stem cell precursor, molecules that lead to osteoblastogenesis inhibit adipogenesis and vice versa. Here we will discuss the role of the key molecules regulating adipocytes and osteoblasts differentiation, which are peroxisome proliferators activated receptor-γ and Wnts, respectively. In particular, we will focus on the role of both canonical and non-canonical Wnt signalling, involved in mesenchymal cell fate regulation. Moreover, at present there are no experimental data that relate any influence of the Wnt inhibitor Sclerostin to adipogenesis, although it is well known its role on bone metabolism. In addition, the most common pathological condition in which there is a simultaneous increase of adiposity and decrease of bone mass is menopause. Given that postmenopausal women have high Sclerostin level inversely associated with circulating estradiol level and since the sex hormone replacement therapy has proved to be effective in attenuating bone loss and reversing menopause-related obesity, we hypothesize that Sclerostin contribution in adipogenesis could be an active focus of research in the coming years.

  20. miR-942 promotes cancer stem cell-like traits in esophageal squamous cell carcinoma through activation of Wnt/β-catenin signalling pathway.

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    Ge, Chunlei; Wu, Shikai; Wang, Weiwei; Liu, Zhimin; Zhang, Jianhua; Wang, Zhenyu; Li, Ruilei; Zhang, Zhiwei; Li, Zhen; Dong, Suwei; Wang, Ying; Xue, Yuanbo; Yang, Jinyan; Tan, Qinghua; Wang, Ziping; Song, Xin

    2015-05-10

    The Wnt/β-catenin signalling pathway is known to play a vital role in the maintenance of cancer stem cells (CSCs), which are reported to be the origin of malignant cancers, and result in poor prognosis of multiple kinds of cancer. Therefore, it is of great importance to illuminate the mechanism by which the Wnt/β-catenin pathway regulates the cancer stem cell-like traits in cancers. Here, we report that miR-942 is significantly upregulated in esophageal squamous cell carcinoma (ESCC), and miR-942 levels are associated with poor prognosis in ESCC patients. Overexpression of miR-942 promotes, whereas inhibition of miR-942 decreases, the tumor sphere formation, the CD90+ subpopulation cells and the expression of pluripotency associated markers. Moreover, in vivo assay shows that miR-942 overexpressing cells form larger tumors and display higher tumourigenesis. Furthermore, we demonstrate that miR-942 upregulates the Wnt/β-catenin signaling activity via directly targeting sFRP4, GSK3β and TLE1, which are multiple level negative regulators of the Wnt/β-catenin signaling cascade. In addition, our results indicate that c-myc directly binds to the miR-942 promoter and promotes its expression. Taken together, our findings establish an oncogenic role of miR-942 in ESCC and indicate that miR-942 might be an effective therapeutic target for ESCC.

  1. Wnt-β Catenin Signaling Pathway: A Major Player in the Injury Induced Fibrosis and Dysfunction of the External Anal Sphincter.

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    Rajasekaran, M Raj; Kanoo, Sadhana; Fu, Johnny; Bhargava, Valmik; Mittal, Ravinder K

    2017-04-19

    Wnt-β catenin is an important signaling pathway in the genesis of fibrosis in many organ systems. Our goal was to examine the role of Wnt pathway in the external anal sphincter (EAS) injury-related fibrosis and muscle dysfunction. New Zealand White female rabbits were subjected to surgical EAS myotomy and administered local injections of either a Wnt antagonist (sFRP-2; daily for 7 days) or saline. Anal canal pressure and EAS length-tension (L-T) were measured for 15 weeks after which the animals were sacrificed. Anal canal was harvested and processed for histochemical studies (Masson trichrome stain), molecular markers of fibrosis (collagen and transforming growth factor-β) and immunostaining for β catenin. Surgical myotomy of the EAS resulted in significant impairment in anal canal pressure and EAS muscle L-T function. Following myotomy, the EAS muscle was replaced with fibrous tissue. Immunostaining revealed β catenin activation and molecular studies revealed 1.5-2 fold increase in the levels of markers of fibrosis. Local injection of sFRP-2 attenuated the β catenin activation and fibrosis. EAS muscle content and function was significantly improved following sFRP-2 treatment. Our studies suggest that upregulation of Wnt signaling is an important molecular mechanism of injury related EAS muscle fibrosis and sphincter dysfunction.

  2. H. pylori virulence factor CagA increases intestinal cell proliferation by Wnt pathway activation in a transgenic zebrafish model

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    James T. Neal

    2013-05-01

    Infection with Helicobacter pylori is a major risk factor for the development of gastric cancer, and infection with strains carrying the virulence factor CagA significantly increases this risk. To investigate the mechanisms by which CagA promotes carcinogenesis, we generated transgenic zebrafish expressing CagA ubiquitously or in the anterior intestine. Transgenic zebrafish expressing either the wild-type or a phosphorylation-resistant form of CagA exhibited significantly increased rates of intestinal epithelial cell proliferation and showed significant upregulation of the Wnt target genes cyclinD1, axin2 and the zebrafish c-myc ortholog myca. Coexpression of CagA with a loss-of-function allele encoding the β-catenin destruction complex protein Axin1 resulted in a further increase in intestinal proliferation. Coexpression of CagA with a null allele of the key β-catenin transcriptional cofactor Tcf4 restored intestinal proliferation to wild-type levels. These results provide in vivo evidence of Wnt pathway activation by CagA downstream of or in parallel to the β-catenin destruction complex and upstream of Tcf4. Long-term transgenic expression of wild-type CagA, but not the phosphorylation-resistant form, resulted in significant hyperplasia of the adult intestinal epithelium. We further utilized this model to demonstrate that oncogenic cooperation between CagA and a loss-of-function allele of p53 is sufficient to induce high rates of intestinal small cell carcinoma and adenocarcinoma, establishing the utility of our transgenic zebrafish model in the study of CagA-associated gastrointestinal cancers.

  3. Rational design of DKK3 structure-based small peptides as antagonists of Wnt signaling pathway and in silico evaluation of their efficiency.

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    Mansour Poorebrahim

    Full Text Available Dysregulated Wnt signaling pathway is highly associated with the pathogenesis of several human cancers. Dickkopf proteins (DKKs are thought to inhibit Wnt signaling pathway through binding to lipoprotein receptor-related protein (LRP 5/6. In this study, based on the 3-dimensional (3D structure of DKK3 Cys-rich domain 2 (CRD2, we have designed and developed several peptide inhibitors of Wnt signaling pathway. Modeller 9.15 package was used to predict 3D structure of CRD2 based on the Homology modeling (HM protocol. After refinement and minimization with GalaxyRefine and NOMAD-REF servers, the quality of selected models was evaluated utilizing VADAR, SAVES and ProSA servers. Molecular docking studies as well as literature-based information revealed two distinct boxes located at CRD2 which are actively involved in the DKK3-LRP5/6 interaction. A peptide library was constructed conducting the backrub sequence tolerance scanning protocol in Rosetta3.5 according to the DKK3-LRP5/6 binding sites. Seven tolerated peptides were chosen and their binding affinity and stability were improved by some logical amino acid substitutions. Molecular dynamics (MD simulations of peptide-LRP5/6 complexes were carried out using GROMACS package. After evaluation of binding free energies, stability, electrostatic potential and some physicochemical properties utilizing computational approaches, three peptides (PEP-I1, PEP-I3 and PEP-II2 demonstrated desirable features. However, all seven improved peptides could sufficiently block the Wnt-binding site of LRP6 in silico. In conclusion, we have designed and improved several small peptides based on the LRP6-binding site of CRD2 of DKK3. These peptides are highly capable of binding to LRP6 in silico, and may prevent the formation of active Wnt-LRP6-Fz complex.

  4. ATRA Signaling Regulates the Expression of COL9A1 through BMP2-WNT4-RUNX1 Pathway in Antler Chondrocytes.

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    Zhang, Hong-Liang; Guo, Bin; Yang, Zhan-Qing; Duan, Cui-Cui; Geng, Shuang; Wang, Kai; Yu, Hai-Fan; Yue, Zhan-Peng

    2017-09-01

    Although all-trans retinoic acid (ATRA) is involved in the regulation of cartilage growth and development, its regulatory mechanisms remain unknown. Here, we showed that ATRA could induce the expression of COL9A1 in antler chondrocytes. Silencing of cellular retinoic acid binding protein 2 (CRABP2) could impede the ATRA-induced upregulation of COL9A1, whereas overexpression of CRABP2 presented the opposite effect. RARα agonist Am80 induced the expression of COL9A1, whereas treatment with RARα antagonist Ro 41-5253 or RXRα small-interfering RNA (siRNA) caused an obvious blockage of ATRA on COL9A1. In antler chondrocytes, CYP26A1 and CYP26B1 weakened the sensitivity of ATRA to COL9A1. Simultaneously, Bone morphogenetic protein 2 (BMP2) and WNT4 mediated the regulation of ATRA on COL9A1 expression. Knockdown of WNT4 could abrogate the inhibitory effect of BMP2 overexpression on COL9A1. Conversely, constitutive expression of WNT4 reversed the upregulation of COL9A1 elicited by BMP2 siRNA. Together these data indicated that WNT4 might act downstream of BMP2 to mediate the effect of ATRA on COL9A1 expression. Further analysis evidenced that attenuation of runt-related transcription factor 1 (RUNX1) could prevent the stimulation of ATRA on COL9A1 expression, while exogenous rRUNX1 further enhanced this effectiveness. Moreover, RUNX1 might serve as an intermediate to mediate the regulation of BMP2 and WNT4 on COL9A1 expression. Collectively, ATRA signaling might regulate the expression of COL9A1 through BMP2-WNT4-RUNX1 pathway. © 2017 Wiley Periodicals, Inc.

  5. Age-related external anal sphincter muscle dysfunction and fibrosis: possible role of Wnt/β-catenin signaling pathways.

    Science.gov (United States)

    Rajasekaran, M Raj; Kanoo, Sadhana; Fu, Johnny; Nguyen, My-Uyen Lilly; Bhargava, Valmik; Mittal, Ravinder K

    2017-12-01

    Studies show an age-related increase in the prevalence of anal incontinence and sphincter muscle atrophy. The Wnt/β-catenin signaling pathway has been recently recognized as the major molecular pathway involved in age-related skeletal muscle atrophy and fibrosis. The goals of our study were to 1) evaluate the impact of normal aging on external anal sphincter (EAS) muscle length-tension (L-T) function and morphology and 2) specifically examine the role of Wnt signaling pathways in anal sphincter muscle fibrosis. New Zealand White female rabbits [6 young (6 mo of age) and 6 old (36 mo of age)] were anesthetized, and anal canal pressure was measured to determine the L-T function of EAS. Animals were killed at the end of the study, and the anal canal was harvested and processed for histochemical studies (Masson trichrome stain for muscle/connective tissue) as well as for molecular markers for fibrosis and atrophy [collagen I, β-catenin, transforming growth factor-β (TGF-β), atrogin-1, and muscle-specific RING finger protein-1 (MuRF-1)]. The L-T was significantly impaired in older animals compared with young animals. Anal canal sections stained with trichrome showed a significant decrease in the muscle content (52% in old compared with 70% in young) and an increase in the connective tissue/collagen content in the old animals. An increased protein and mRNA expression of all the fibrosis markers was seen in the older animals. Aging EAS muscle exhibits impairment of function and increase in connective tissue. Upregulation of atrophy and profibrogenic proteins with aging may be the reason for the age-related decrease in anal sphincter muscle thickness and function.NEW & NOTEWORTHY Our studies using a female rabbit model show age-related alterations in the structure and function of the external anal sphincter (EAS) muscle. We used endoluminal ultrasound to measure age-related changes in EAS muscle thickness. We employed Western blot and quantitative PCR to demonstrate

  6. Activation of the Wnt/β-catenin signaling pathway by mechanical ventilation is associated with ventilator-induced pulmonary fibrosis in healthy lungs.

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    Jesús Villar

    Full Text Available BACKGROUND: Mechanical ventilation (MV with high tidal volumes (V(T can cause or aggravate lung damage, so-called ventilator induced lung injury (VILI. The relationship between specific mechanical events in the lung and the cellular responses that result in VILI remains incomplete. Since activation of Wnt/β-catenin signaling has been suggested to be central to mechanisms of lung healing and fibrosis, we hypothesized that the Wnt/β-catenin signaling plays a role during VILI. METHODOLOGY/PRINCIPAL FINDINGS: Prospective, randomized, controlled animal study using adult, healthy, male Sprague-Dawley rats. Animals (n = 6/group were randomized to spontaneous breathing or two strategies of MV for 4 hours: low tidal volume (V(T (6 mL/kg or high V(T (20 mL/kg. Histological evaluation of lung tissue, measurements of WNT5A, total β-catenin, non-phospho (Ser33/37/Thr41 β-catenin, matrix metalloproteinase-7 (MMP-7, cyclin D1, vascular endothelial growth factor (VEGF, and axis inhibition protein 2 (AXIN2 protein levels by Western blot, and WNT5A, non-phospho (Ser33/37/Thr41 β-catenin, MMP-7, and AXIN2 immunohistochemical localization in the lungs were analyzed. High-V(T MV caused lung inflammation and perivascular edema with cellular infiltrates and collagen deposition. Protein levels of WNT5A, non-phospho (Ser33/37/Thr41 β-catenin, MMP-7, cyclin D1, VEGF, and AXIN2 in the lungs were increased in all ventilated animals although high-V(T MV was associated with significantly higher levels of WNT5A, non-phospho (Ser33/37/Thr41 β-catenin, MMP-7, cyclin D1, VEGF, and AXIN2 levels. CONCLUSIONS/SIGNIFICANCE: Our findings demonstrate that the Wnt/β-catenin signaling pathway is modulated very early by MV in lungs without preexistent lung disease, suggesting that activation of this pathway could play an important role in both VILI and lung repair. Modulation of this pathway might represent a therapeutic option for prevention and/or management of VILI.

  7. Collagen synthesis disruption and downregulation of core elements of TGF-β, Hippo, and Wnt pathways in keratoconus corneas.

    Science.gov (United States)

    Kabza, Michal; Karolak, Justyna A; Rydzanicz, Malgorzata; Szcześniak, Michał W; Nowak, Dorota M; Ginter-Matuszewska, Barbara; Polakowski, Piotr; Ploski, Rafal; Szaflik, Jacek P; Gajecka, Marzena

    2017-05-01

    To understand better the factors contributing to keratoconus (KTCN), we performed comprehensive transcriptome profiling of human KTCN corneas for the first time using an RNA-Seq approach. Twenty-five KTCN and 25 non-KTCN corneas were enrolled in this study. After RNA extraction, total RNA libraries were prepared and sequenced. The discovery RNA-Seq analysis (in eight KTCN and eight non-KTCN corneas) was conducted first, after which the replication RNA-Seq experiment was performed on a second set of samples (17 KTCN and 17 non-KTCN corneas). Over 82% of the genes and almost 75% of the transcripts detected as differentially expressed in KTCN and non-KTCN corneas were confirmed in the replication study using another set of samples. We used these differentially expressed genes to generate a network of KTCN-deregulated genes. We found an extensive disruption of collagen synthesis and maturation pathways, as well as downregulation of the core elements of the TGF-β, Hippo, and Wnt signaling pathways influencing corneal organization. This first comprehensive transcriptome profiling of human KTCN corneas points further to a complex etiology of KTCN.

  8. Integration of prior biological knowledge and epigenetic information enhances the prediction accuracy of the Bayesian Wnt pathway.

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    Sinha, Shriprakash

    2014-11-01

    Computational modeling of the Wnt signaling pathway has gained prominence for its use as a diagnostic tool to develop therapeutic cancer target drugs and predict test samples as tumorous/normal. Diagnostic tools entail modeling of the biological phenomena behind the pathway while prediction requires inclusion of factors for discriminative classification. This manuscript develops simple static Bayesian network predictive models of varying complexity by encompassing prior partially available biological knowledge about intra/extracellular factors and incorporating information regarding epigenetic modification into a few genes that are known to have an inhibitory effect on the pathway. Incorporation of epigenetic information enhances the prediction accuracy of test samples in human colorectal cancer. In comparison to the Naive Bayes model where β-catenin transcription complex activation predictions are assumed to correspond to sample predictions, the new biologically inspired models shed light on differences in behavior of the transcription complex and the state of samples. Receiver operator curves and their respective area under the curve measurements obtained from predictions of the state of the test sample and the corresponding predictions of the state of activation of the β-catenin transcription complex of the pathway for the test sample indicate a significant difference between the transcription complex being on (off) and its association with the sample being tumorous (normal). The two-sample Kolmogorov-Smirnov test confirms the statistical deviation between the distributions of these predictions. Hitherto unknown relationship between factors like DKK2, DKK3-1 and SFRP-2/3/5 w.r.t. the β-catenin transcription complex has been inferred using these causal models.

  9. The role of Wnt signaling in neuronal dysfunction in Alzheimer's Disease

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    Toledo Enrique M

    2008-07-01

    Full Text Available Abstract Recent evidence supports a neuroprotective role for Wnt signaling in neurodegenerative disorders such as Alzheimer's Disease (AD. In fact, a relationship between amyloid-β-peptide (Aβ-induced neurotoxicity and a decrease in the cytoplasmic levels of β-catenin has been observed. Apparently Aβ binds to the extracellular cysteine-rich domain of the Frizzled receptor (Fz inhibiting Wnt/β-catenin signaling. Cross-talk with other signaling cascades that regulate Wnt/β-catenin signaling, including the activation of M1 muscarinic receptor and PKC, the use of Ibuprofen-ChE bi-functional compounds, PPAR α, γ agonists, nicotine and some antioxidants, results in neuroprotection against Aβ. These studies indicate that a sustained loss of Wnt signaling function may be involved in the Aβ-dependent neurodegeneration observed in Alzheimer's brain. In conclusion the activation of the Wnt signaling pathway could be proposed as a therapeutic target for the treatment of AD.

  10. Education for Sustainability: Assessing Pathways to the Future

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    Huckle, John

    2014-01-01

    In this paper John Huckle reflects on the outlook of environmental education based on conferences in 1972 and 1992 regarding the lack of sustainable development being realized. Huckle points "education for sustainability" along a pathway provided by critical theory and pedagogy and uses theory to examine the nature of ecological crisis,…

  11. The inhibition of EZH2 ameliorates osteoarthritis development through the Wnt/β-catenin pathway

    Science.gov (United States)

    Chen, Linwei; Wu, Yaosen; Wu, Yan; Wang, Ye; Sun, Liaojun; Li, Fangcai

    2016-01-01

    The purpose of our study was to elucidate the role of the histone methyltransferase enhancer of zeste homologue 2 (EZH2) in the pathophysiology of osteoarthritis (OA) and to develop a strategy to modulate EZH2 activity for OA treatment. The expression of EZH2 in normal and OA human cartilage was compared by western blotting. The effect of EZH2 overexpression and inhibition on chondrocyte hypertrophy related gene expression was examined by real-time PCR, and histone methylation on the promoter of the Wnt inhibitor SFRP1 was analyzed using a chromatin immunoprecipitation (ChIP) PCR. Histological assessment of OA mice joint was carried out to assess the in vivo effects of EZH2 inhibitor EPZ005687. We found EZH2 level was significantly increased in the chondrocytes of OA patients compared to normal humans. Overexpression of EZH2 promoted Indian Hedgehog, MMP-13, ADAMTS-5 and COLX expression, while inhibition of EZH2 reversed this trend. Furthermore, the induction of EZH2 led to β-catenin signaling activation by increasing H3K27me3 on the promoter of SFRP1, while the inhibition of EZH2 silenced β-catenin signaling. Finally, intraarticular injection of EPZ005687 delayed OA development in mice. These results implicated EZH2 activity in OA development. Pharmacological inhibition of EZH2 may be an effective therapeutic approach for osteoarthritis. PMID:27539752

  12. Sharing Economy:A Potential New Pathway to Sustainability

    OpenAIRE

    Heinrichs, Harald

    2013-01-01

    Despite the success of some environmental and sustainability initiatives and measures in policy-making, business and society, overall trends follow an unsustainable path. Especially in the field of production and consumption of goods and services, environmental sustainability and social equality remain critical challenges. Therefore new approaches are needed alongside existing strategies and policy instruments. The "sharing economy" has the potential to provide a new pathway to sustainability...

  13. Wnt5a attenuates Wnt3a-induced alkaline phosphatase expression in dental follicle cells

    Energy Technology Data Exchange (ETDEWEB)

    Sakisaka, Yukihiko [Department of Periodontology and Endodontology, Tohoku University Graduate School of Dentistry, Sendai 980-8575 (Japan); Tsuchiya, Masahiro [Department of Oral Diagnosis, Tohoku University Graduate School of Dentistry, Sendai 980-8575 (Japan); Tohoku Fukushi University, Sendai 989-3201 (Japan); Nakamura, Takashi [Department of Pediatric Dentistry, Tohoku University Graduate School of Dentistry, Sendai 980-8575 (Japan); Liason Center for Innovative Dentistry, Tohoku University Graduate School of Dentistry, Sendai 980-8575 (Japan); Tamura, Masato [Department of Biochemistry and Molecular Biology, Hokkaido University Graduate School of Dentistry, Sapporo 060-8586 (Japan); Shimauchi, Hidetoshi [Department of Periodontology and Endodontology, Tohoku University Graduate School of Dentistry, Sendai 980-8575 (Japan); Nemoto, Eiji, E-mail: e-nemoto@dent.tohoku.ac.jp [Department of Periodontology and Endodontology, Tohoku University Graduate School of Dentistry, Sendai 980-8575 (Japan)

    2015-08-01

    Wnt signaling regulates multiple cellular events such as cell proliferation, differentiation, and apoptosis through β-catenin-dependent canonical and β-catenin-independent noncanonical pathways. Canonical Wnt/β-catenin signaling can promote the differentiation of dental follicle cells, putative progenitor cells for cementoblasts, osteoblasts, and periodontal ligament cells, toward a cementoblast/osteoblast phenotype during root formation, but little is known about the biological significance of noncanonical Wnt signaling in this process. We identified the expression of Wnt5a, a representative noncanonical Wnt ligand, in tooth root lining cells (i.e. precementoblasts/cementoblasts) and dental follicle cells during mouse tooth root development, as assessed by immunohistochemistry. Silencing expression of the Wnt5a gene in a dental follicle cell line resulted in enhancement of the Wnt3a (a representative canonical Wnt ligand)-mediated increase in alkaline phosphatase (ALP) expression. Conversely, treatment with recombinant Wnt5a inhibited the increase in ALP expression, suggesting that Wnt5a signaling functions as a negative regulator of canonical Wnt-mediated ALP expression of dental follicle cells. Wnt5a did not affect the nuclear translocation of β-catenin as well as β-catenin-mediated transcriptional activation of T-cell factor (Tcf) triggered by Wnt3a, suggesting that Wnt5a inhibits the downstream part of the β-catenin-Tcf pathway. These findings suggest the existence of a feedback mechanism between canonical and noncanonical Wnt signaling during the differentiation of dental follicle cells. - Highlights: • Dental follicle cells express Wnt5a during tooth root development. • Silencing of Wnt5a enhances Wnt3a-mediated ALP expression of dental follicle cells. • Conversely, treatment with rWnt5a inhibited the increase in ALP expression. • Wnt5a functions as a negative regulator of Wnt3a-mediated ALP expression.

  14. Application of Wnt Pathway Inhibitor Delivering Scaffold for Inhibiting Fibrosis in Urethra Strictures: In Vitro and in Vivo Study

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    Kaile Zhang

    2015-11-01

    Full Text Available Objective: To evaluate the mechanical property and biocompatibility of the Wnt pathway inhibitor (ICG-001 delivering collagen/poly(l-lactide-co-caprolactone (P(LLA-CL scaffold for urethroplasty, and also the feasibility of inhibiting the extracellular matrix (ECM expression in vitro and in vivo. Methods: ICG-001 (1 mg (2 mM was loaded into a (P(LLA-CL scaffold with the co-axial electrospinning technique. The characteristics of the mechanical property and drug release fashion of scaffolds were tested with a mechanical testing machine (Instron and high-performance liquid chromatography (HPLC. Rabbit bladder epithelial cells and the dermal fibroblasts were isolated by enzymatic digestion method. (3-(4,5-Dimethylthiazol-2-yl-2,5-Diphenyltetrazolium Bromide (MTT assay and scanning electron microscopy (SEM were used to evaluate the viability and proliferation of the cells on the scaffolds. Fibrolasts treated with TGF-β1 and ICG-001 released medium from scaffolds were used to evaluate the anti-fibrosis effect through immunofluorescence, real time PCR and western blot. Urethrography and histology were used to evaluate the efficacy of urethral implantation. Results: The scaffold delivering ICG-001 was fabricated, the fiber diameter and mechanical strength of scaffolds with inhibitor were comparable with the non-drug scaffold. The SEM and MTT assay showed no toxic effect of ICG-001 to the proliferation of epithelial cells on the collagen/P(LLA-CL scaffold with ICG-001. After treatment with culture medium released from the drug-delivering scaffold, the expression of Collagen type 1, 3 and fibronectin of fibroblasts could be inhibited significantly at the mRNA and protein levels. In the results of urethrography, urethral strictures and fistulas were found in the rabbits treated with non-ICG-001 delivering scaffolds, but all the rabbits treated with ICG-001-delivering scaffolds showed wide caliber in urethras. Histology results showed less collagen but more

  15. A deep investigation into the adipogenesis mechanism: Profile of microRNAs regulating adipogenesis by modulating the canonical Wnt/β-catenin signaling pathway

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    Li Jing

    2010-05-01

    Full Text Available Abstract Background MicroRNAs (miRNAs are a large class of tiny non-coding RNAs (~22-24 nt that regulate diverse biological processes at the posttranscriptional level by controlling mRNA stability or translation. As a molecular switch, the canonical Wnt/β-catenin signaling pathway should be suppressed during the adipogenesis; However, activation of this pathway leads to the inhibition of lipid depots formation. The aim of our studies was to identify miRNAs that might be involved in adipogenesis by modulating WNT signaling pathway. Here we established two types of cell model, activation and repression of WNT signaling, and investigated the expression profile of microRNAs using microarray assay. Results The high throughput microarray data revealed 18 miRNAs that might promote adipogenesis by repressing WNT signaling: miR-210, miR-148a, miR-194, miR-322 etc. Meanwhile, we also identified 29 miRNAs that might have negative effect on adipogenesis by activating WNT signaling: miR-344, miR-27 and miR-181 etc. The targets of these miRNAs were also analysed by bioinformatics. To validate the predicted targets and the potential functions of these identified miRNAs, the mimics of miR-210 were transfected into 3T3-L1 cells and enlarged cells with distinct lipid droplets were observed; Meanwhile, transfection with the inhibitor of miR-210 could markedly decrease differentiation-specific factors at the transcription level, which suggested the specific role of miR-210 in promoting adipogenesis. Tcf7l2, the predicted target of miR-210, is a transcription factor triggering the downstream responsive genes of WNT signaling, was blocked at transcription level. Furthermore, the activity of luciferase reporter bearing Tcf7l2 mRNA 3' UTR was decreased after co-transfection with miR-210 in HEK-293FT cells. Last but not least, the protein expression level of β-catenin was increased in the lithium (LiCl treated 3T3-L1 cells after transfection with miR-210. These

  16. Pentazocine Protects SN4741 Cells Against MPP+-Induced Cell Damage via Up-Regulation of the Canonical Wnt/β-Catenin Signaling Pathway

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    Jiancai Wang

    2017-06-01

    Full Text Available The Wnt/β-catenin signaling pathway has been linked to many neurodegenerative diseases including Parkinson’s disease (PD. A glycoprotein named Dickkopf-1 (Dkk1 can combine with the receptor complex on cell membrane to inhibit Wnt/β-catenin signaling. Opioids, a series of compounds including morphine, fentanyl and pentazocine, have been reported to contribute to the up-regulation of Wnt/β-catenin signaling. Naloxone is an antagonist that has been used as an antidote to opioids through mu-opioid receptor. 1-methyl-4-phenylpyridinium (MPP+, which serves as a selective toxin for dopaminergic neurons, has been used to create experimental models of PD. In our study, we examined the protective effects of pentazocine against MPP+-induced cell death in the nigral dopaminergic cell line, SN4741 and tried to elucidate the molecular mechanisms underlying such protective effects. The data showed that pretreatment with pentazocine significantly rescued the SN4741 cell against MPP+. Moreover, the MPP+-exposed SN4741 cells exhibited a down-regulation of β-catenin, which could be restored by treatment with pentazocine. However, Dkk1 but not naloxonewas associated with the abrogation of protective effect of pentazocine. These results suggest that pentazocine alleviates MPP+-induced SN4741 cells apoptosis via the up-regulation of canonical Wnt/β-catenin signaling.

  17. Pomegranate Bioactive Constituents Suppress Cell Proliferation and Induce Apoptosis in an Experimental Model of Hepatocellular Carcinoma: Role of Wnt/β-Catenin Signaling Pathway

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    Deepak Bhatia

    2013-01-01

    Full Text Available Hepatocellular carcinoma (HCC is the third leading cause of cancer-related death worldwide, and chemoprevention represents a viable approach in lowering the mortality of this disease. Pomegranate fruit, an abundant source of anti-inflammatory phytochemicals, is gaining tremendous attention for its wide-spectrum health benefits. We previously reported that a characterized pomegranate emulsion (PE prevents diethylnitrosamine (DENA-induced rat hepatocarcinogenesis though inhibition of nuclear factor-kappaB (NF-κB. Since NF-κB concurrently induces Wnt/β-catenin signaling implicated in cell proliferation, cell survival, and apoptosis evasion, we examined antiproliferative, apoptosis-inducing and Wnt/β-catenin signaling-modulatory mechanisms of PE during DENA rat hepatocarcinogenesis. PE (1 or 10 g/kg was administered 4 weeks before and 18 weeks following DENA exposure. There was a significant increase in hepatic proliferation (proliferating cell nuclear antigen and alteration in cell cycle progression (cyclin D1 due to DENA treatment, and PE dose dependently reversed these effects. PE substantially induced apoptosis by upregulating proapoptotic protein Bax and downregulating antiapoptotic protein Bcl-2. PE dose dependently reduced hepatic β-catenin and augmented glycogen synthase kinase-3β expression. Our study provides evidence that pomegranate phytochemicals exert chemoprevention of hepatic cancer through antiproliferative and proapoptotic mechanisms by modulating Wnt/β-catenin signaling. PE, thus, targets two interconnected molecular circuits (canonical NF-κB and Wnt/β-catenin pathways to exert chemoprevention of HCC.

  18. LGALS3 and AXIN1 gene variants playing role in the Wnt/ β-catenin signaling pathway are associated with mucinous component and tumor size in colorectal cancer

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    Gurbet Korkmaz

    2016-02-01

    Full Text Available The Wnt pathway alterations have been identified in colorectal and many other cancer types. It has been reported that galectin-3 (which is encoded by the LGALS3 gene alters the signaling mechanism in the Wnt/ β-catenin pathway by binding to β-catenin in colon and other cancers. AXIN1 is mainly responsible for the assembly of the β-catenin destruction complex in the Wnt pathway. This study investigated the relationship of rs4644 and rs4652 variants of the LGALS3 gene and rs214250 variants of the AXIN1 gene to histopathological and clinical properties. Our study included a total of 236 patients, of whom 119 had colorectal cancer (42 women, 77 men and 117 were healthy controls. Polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP and allele-specific oligonucleotide (ASO PCR methods were used. In addition, the serum galectin-3 level was studied with the enzyme-linked immunosorbent assay (ELISA method. For the rs4644 variant of the LGALS3 gene, the CC genotype a mucinous component was significantly more common than those without a mucinous component (p=0.026. C allele frequency of the rs214250 variant of the AXIN1 gene was significantly correlated to tumor size in the advanced tumor stage (p=0.022. The CCAACT haplotype was more common in colorectal cancer patients (p=0.022. Serum galectin-3 level was higher in the patient group compared to the control group (5.9± 0.69 ng/ml vs. 0.79±0.01 ng/ml; p<0.001. In conclusion, variants of LGALS3 and AXIN1 genes affect tumor sizes and the mucinous component via Wnt/ β-catenin pathway in the pathogenesis of colorectal cancer.

  19. Ginkgo biloba Extract Prevents Female Mice from Ischemic Brain Damage and the Mechanism Is Independent of the HO1/Wnt Pathway.

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    Tulsulkar, Jatin; Glueck, Bryan; Hinds, Terry D; Shah, Zahoor A

    2016-04-01

    It is well known that gender differences exist in experimental or clinical stroke with respect to brain damage and loss of functional outcome. We have previously reported neuroprotective properties of Ginkgo biloba/EGb 761® (EGb 761) in transient and permanent mouse models of brain ischemia using male mice, and the mechanism of action was attributed to the upregulation of the heme oxygenase 1 (HO1)/Wnt pathway. Here, we sought to investigate whether EGb 761's protective effect in ovariectomized female mice following stroke is also mediated by the HO1/Wnt pathway. Female mice were ovariectomized (OVX) to remove the protective effect of estrogen and were treated with EGb 761 for 7 days prior to inducing permanent middle cerebral artery occlusion (pMCAO) and allowed to survive for an additional 7 days. At day 8, animals were sacrificed, and the brains were harvested for infarct volume analysis, western blots, and immunohistochemistry. The OVX female mice treated with EGb 761 showed significantly lower infarct size as compared to Veh/OVX animals. EGb 761 treatment in female mice inhibited apoptosis by preventing caspase-3 cleavage and blocking the extrinsic apoptotic pathway. EGb 761 pretreatment significantly enhanced neurogenesis in OVX mice as compared to the Veh/OVX group and significantly upregulated androgen receptor expression with no changes in HO1/Wnt signaling. These results suggest that EGb 761 prevented brain damage in OVX female mice by improving grip strength and neurological deficits, and the mechanism of action is not through HO1/Wnt but via blocking the extrinsic apoptotic pathway.

  20. DIF-1 inhibits the Wnt/β-catenin signaling pathway by inhibiting TCF7L2 expression in colon cancer cell lines.

    Science.gov (United States)

    Jingushi, Kentaro; Takahashi-Yanaga, Fumi; Yoshihara, Tatsuya; Shiraishi, Fumie; Watanabe, Yutaka; Hirata, Masato; Morimoto, Sachio; Sasaguri, Toshiyuki

    2012-01-01

    We previously reported that differentiation-inducing factor-1 (DIF-1), a morphogen in Dictyostelium discoideum, inhibits the proliferation of human cancer cell lines by inducing β-catenin degradation and suppressing the Wnt/β-catenin signaling pathway. To determine whether β-catenin degradation is essential for the effect of DIF-1, we examined the effect of DIF-1 on human colon cancer cell lines (HCT-116, SW-620 and DLD-1), in which the Wnt/β-catenin signaling pathway is constitutively active. DIF-1 strongly inhibited cell proliferation and arrested the cell cycle in the G(0)/G(1) phase via the suppression of cyclin D1 expression at mRNA and protein levels without reducing β-catenin protein. TCF-dependent transcriptional activity and cyclin D1 promoter activity were revealed to be inhibited via suppression of transcription factor 7-like 2 (TCF7L2) expression. Luciferase reporter assays and EMSAs using the TCF7L2 promoter fragments indicated that the binding site for the transcription factor early growth response-1 (Egr-1), which is located in the -609 to -601 bp region relative to the start codon in the TCF7L2 promoter, was involved in DIF-1 activity. Moreover, RNAi-mediated depletion of endogenous TCF7L2 resulted in reduced cyclin D1 promoter activity and protein expression, and the overexpression of TCF7L2 overrode the inhibition of the TCF-dependent transcriptional activity and cyclin D1 promoter activity induced by DIF-1. Therefore, DIF-1 seemed to inhibit the Wnt/β-catenin signaling pathway by suppressing TCF7L2 expression via reduced Egr-1-dependent transcriptional activity in these colon cancer cell lines. Our results provide a novel insight into the mechanisms by which DIF-1 inhibits the Wnt/β-catenin signaling pathway. Copyright © 2011 Elsevier Inc. All rights reserved.

  1. The Role of Wnt/β-Catenin Signaling Pathway in Disrupted Hippocampal Neurogenesis of Temporal Lobe Epilepsy: A Potential Therapeutic Target?

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    Huang, Cheng; Fu, Xiang-Hui; Zhou, Dong; Li, Jin-Mei

    2015-07-01

    Temporal lobe epilepsy is one of the most common clinical neurological disorders. One of the major pathological findings in temporal lobe epilepsy is hippocampal sclerosis, characterized by massive neuronal loss and severe gliosis. The epileptogenesis process of temporal lobe epilepsy usually starts with initial precipitating insults, followed by neurodegeneration, abnormal hippocampus circuitry reorganization, and the formation of hypersynchronicity. Experimental and clinical evidence strongly suggests that dysfunctional neurogenesis is involved in the epileptogenesis. Recent data demonstrate that neurogenesis is induced by acute seizures or precipitating insults, whereas the capacity of neuronal recruitment and proliferation substantially decreases in the chronic phase of epilepsy. Participation of the Wnt/β-catenin signaling pathway in neurogenesis reveals its importance in epileptogenesis; its dysfunction contributes to the structural and functional abnormality of temporal lobe epilepsy, while rescuing this pathway exerts neuroprotective effects. Here, we summarize data supporting the involvement of Wnt/β-catenin signaling in the epileptogenesis of temporal lobe epilepsy. We also propose that the Wnt/β-catenin signaling pathway may serve as a promising therapeutic target for temporal lobe epilepsy treatment.

  2. Role of Wnt/β-catenin pathway in the nucleus accumbens in long-term cocaine-induced neuroplasticity: a possible novel target for addiction treatment.

    Science.gov (United States)

    Cuesta, Santiago; Batuecas, Jorgelina; Severin, Maria J; Funes, Alejandrina; Rosso, Silvana B; Pacchioni, Alejandra M

    2017-01-01

    Cocaine addiction is a chronic relapsing disorder characterized by the loss of control over drug-seeking and taking, and continued drug use regardless of adverse consequences. Despite years of research, effective treatments for psycho-stimulant addiction have not been identified. Persistent vulnerability to relapse arises from a number of long-lasting adaptations in the reward circuitry that mediate the enduring response to the drug. Recently, we reported that the activity of the canonical or Wnt/β-catenin pathway in the prefrontal cortex (PFC) is very important in the early stages of cocaine-induced neuroadaptations. In the present work, our main goal was to elucidate the relevance of this pathway in cocaine-induced long-term neuroadaptations that may underlie relapse. We found that a cocaine challenge, after a period of abstinence, induced an increase in the activity of the pathway which is revealed as an increase in the total and nuclear levels of β-catenin (final effector of the pathway) in the nucleus accumbens (NAcc), together with a decrease in the activity of glycogen synthase kinase 3β (GSK3β). Moreover, we found that the pharmacological modulation of the activity of the pathway has long-term effects on the cocaine-induced neuroplasticity at behavioral and molecular levels. All the results imply that changes in the Wnt/β-catenin pathway effectors are long-term neuroadaptations necessary for the behavioral response to cocaine. Even though more research is needed, the present results introduce the Wnt canonical pathway as a possible target to manage cocaine long-term neuroadaptations. © 2016 International Society for Neurochemistry.

  3. WNT1-inducible signaling pathway protein-1 contributes to tumor progression and treatment failure in oral squamous cell carcinoma.

    Science.gov (United States)

    Jung, Eun Kyung; Kim, Sun-Ae; Yoon, Tae Mi; Lee, Kyung-Hwa; Kim, Hee Kyung; Lee, Dong Hoon; Lee, Joon Kyoo; Chung, Ik-Joo; Joo, Young-Eun; Lim, Sang Chul

    2017-08-01

    WNT1-inducible-signaling pathway protein-1 (WISP-1) belongs to the family of cysteine rich 61/connective tissue growth factor/nephroblastoma overexpressed matricellular proteins, which are involved in various biological processes, including cell adhesion, proliferation, differentiation, angiogenesis and carcinogenesis. In the present study, the expression of WISP-1 was investigated, and its association with clinicopathological factors and prognosis in patients with oral squamous cell carcinoma (OSCC) was evaluated. Additionally, the role of WISP-1 in invasion and apoptosis of human OSCC cells was evaluated. Immunoreactivity of WISP-1 was increased in OSCC tissue compared with adjacent normal tissue samples. High expression of WISP-1 protein was observed in 24/84 (28.57%) OSCC specimens. Additionally, high WISP-1 expression was significantly associated with treatment failure (P=0.042). The 5-year overall survival rate was 33% in patients with high WISP1 expression, and 66% in patients with low WISP-1 expression. WISP-1 expression in the human OSCC SCC-1483 cell line was observed. Furthermore, WISP-1 knockdown using small interfering (si)RNA significantly reduced cell invasion and induced apoptosis compared with control siRNA-transfected cells. These findings suggested that WISP-1 is associated with tumor progression and poor prognosis by increasing tumor cell invasion and inhibiting cell apoptosis in human OSCC.

  4. Acceleration of bone development and regeneration through the Wnt/β-catenin signaling pathway in mice heterozygously deficient for GSK-3β

    Energy Technology Data Exchange (ETDEWEB)

    Arioka, Masaki [Department of Clinical Pharmacology, Faculty of Medical Sciences, Kyushu University, Fukuoka (Japan); Department of Oral and Maxillofacial Surgery, Faculty of Dental Science, Kyushu University, Fukuoka (Japan); Takahashi-Yanaga, Fumi, E-mail: yanaga@clipharm.med.kyushu-u.ac.jp [Department of Clinical Pharmacology, Faculty of Medical Sciences, Kyushu University, Fukuoka (Japan); Global Medical Science Education Unit, Faculty of Medical Sciences, Kyushu University, Fukuoka (Japan); Sasaki, Masanori [Department of Oral and Maxillofacial Surgery, Faculty of Dental Science, Kyushu University, Fukuoka (Japan); Yoshihara, Tatsuya; Morimoto, Sachio [Department of Clinical Pharmacology, Faculty of Medical Sciences, Kyushu University, Fukuoka (Japan); Takashima, Akihiko [Department of Aging Neurobiology, National Center for Geriatrics and Gerontology, Oobu (Japan); Mori, Yoshihide [Department of Oral and Maxillofacial Surgery, Faculty of Dental Science, Kyushu University, Fukuoka (Japan); Sasaguri, Toshiyuki [Department of Clinical Pharmacology, Faculty of Medical Sciences, Kyushu University, Fukuoka (Japan)

    2013-11-01

    Highlights: •The Wnt/β-catenin signaling pathway was activated in GSK-3β{sup +/−} mice. •The cortical and trabecular bone volumes were increased in GSK-3β{sup +/−} mice. •Regeneration of a partial bone defect was accelerated in GSK-3β{sup +/−} mice. -- Abstract: Glycogen synthase kinase (GSK)-3β plays an important role in osteoblastogenesis by regulating the Wnt/β-catenin signaling pathway. Therefore, we investigated whether GSK-3β deficiency affects bone development and regeneration using mice heterozygously deficient for GSK-3β (GSK-3β{sup +/−}). The amounts of β-catenin, c-Myc, cyclin D1, and runt-related transcription factor-2 (Runx2) in the bone marrow cells of GSK-3β{sup +/−} mice were significantly increased compared with those of wild-type mice, indicating that Wnt/β-catenin signals were enhanced in GSK-3β{sup +/−} mice. Microcomputed tomography of the distal femoral metaphyses demonstrated that the volumes of both the cortical and trabecular bones were increased in GSK-3β{sup +/−} mice compared with those in wild-type mice. Subsequently, to investigate the effect of GSK-3β deficiency on bone regeneration, we established a partial bone defect in the femur and observed new bone at 14 days after surgery. The volume and mineral density of the new bone were significantly higher in GSK-3β{sup +/−} mice than those in wild-type mice. These results suggest that bone formation and regeneration in vivo are accelerated by inhibition of GSK-3β, probably through activation of the Wnt/β-catenin signaling pathway.

  5. Substance P Activates the Wnt Signal Transduction Pathway and Enhances the Differentiation of Mouse Preosteoblastic MC3T3-E1 Cells

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    Gang Mei

    2014-04-01

    Full Text Available Recent experiments have explored the impact of Wnt/β-catenin signaling and Substance P (SP on the regulation of osteogenesis. However, the molecular regulatory mechanisms of SP on the formation of osteoblasts is still unknown. In this study, we investigated the impact of SP on the differentiation of MC3T3-E1 cells. The osteogenic effect of SP was observed at different SP concentrations (ranging from 10−10 to 10−8 M. To unravel the underlying mechanism, the MC3T3-E1 cells were treated with SP after the pretreatment by neurokinin-1 (NK1 antagonists and Dickkopf-1 (DKK1 and gene expression levels of Wnt/β-catenin signaling pathway components, as well as osteoblast differentiation markers (collagen type I, alkaline phosphatase, osteocalcin, and Runx2, were measured using quantitative polymerase chain reaction (PCR. Furthermore, protein levels of Wnt/β-catenin signaling pathway were detected using Western blotting and the effects of SP, NK1 antagonist, and DKK1 on β-catenin activation were investigated by immunofluorescence staining. Our data indicated that SP (10−9 to 10−8 M significantly up-regulated the expressions of osteoblastic genes. SP (10−8 M also elevated the mRNA level of c-myc, cyclin D1, and lymphocyte enhancer factor-1 (Lef1, as well as c-myc and β-catenin protein levels, but decreased the expression of Tcf7 mRNA. Moreover, SP (10−8 M promoted the transfer of β-catenin into nucleus. The effects of SP treatment were inhibited by the NK1 antagonist and DKK1. These findings suggest that SP may enhance differentiation of MC3T3-E1 cells via regulation of the Wnt/β-catenin signaling pathway.

  6. Non-Canonical Hedgehog Signaling Is a Positive Regulator of the WNT Pathway and Is Required for the Survival of Colon Cancer Stem Cells

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    Joseph L. Regan

    2017-12-01

    Full Text Available Summary: Colon cancer is a heterogeneous tumor driven by a subpopulation of cancer stem cells (CSCs. To study CSCs in colon cancer, we used limiting dilution spheroid and serial xenotransplantation assays to functionally define the frequency of CSCs in a panel of patient-derived cancer organoids. These studies demonstrated cancer organoids to be enriched for CSCs, which varied in frequency between tumors. Whole-transcriptome analysis identified WNT and Hedgehog signaling components to be enhanced in CSC-enriched tumors and in aldehyde dehydrogenase (ALDH-positive CSCs. Canonical GLI-dependent Hedgehog signaling is a negative regulator of WNT signaling in normal intestine and intestinal tumors. Here, we show that Hedgehog signaling in colon CSCs is autocrine SHH-dependent, non-canonical PTCH1 dependent, and GLI independent. In addition, using small-molecule inhibitors and RNAi against SHH-palmitoylating Hedgehog acyltransferase (HHAT, we demonstrate that non-canonical Hedgehog signaling is a positive regulator of WNT signaling and required for colon CSC survival. : Colon cancer is a heterogeneous tumor driven by a subpopulation(s of therapy-resistant cancer stem cells (CSCs. Regan et al. use 3D culture models to demonstrate that CSC survival is regulated by non-canonical, SHH-dependent, PTCH1-dependent Hedgehog signaling, which acts as a positive regulator of WNT signaling to block CSC differentiation. Keywords: WNT pathway, non-canonical Hedgehog signaling, cancer stem cell, colon cancer, cancer organoid, PTCH1, HHAT, SHH

  7. Tumours with elevated levels of the Notch and Wnt pathways exhibit efficacy to PF-03084014, a γ-secretase inhibitor, in a preclinical colorectal explant model

    OpenAIRE

    Arcaroli, J J; Quackenbush, K S; Purkey, A; Powell, R W; Pitts, T.M.; Bagby, S.; Tan, A C; Cross, B; McPhillips, K; Song, E-K; Tai, W. M.; Winn, R A; Bikkavilli, K; VanScoyk, M; Eckhardt, S G

    2013-01-01

    Background: Dysregulation of the Notch pathway has been identified to play an important role in the development and progression of colorectal cancer (CRC). In this study, we used a patient-derived CRC explant model to investigate the efficacy of the clinical γ-secretase inhibitor (GSI) PF-03084014. Methods: A total of 16 CRC explants were treated with PF-03084014. Knockdown of RBPj κ gene was used to determine the specificity of PF-03084014. Evaluation of the Notch and Wnt pathways in CRC exp...

  8. Ellagic acid regulates Wnt/β-catenin signaling pathway and CDK8 in HCT 116 and HT 29 colon cancer cells

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    Yang Fang

    2015-03-01

    Full Text Available Colorectal cancer is one of the leading causes of death worldwide. Wnt/β-catenin signalling pathway plays a central role in normal cellular responses, making it a potent target in cancer therapy. Study was taken to assess whether ellagic acid modulates Wnt/β-catenin pathway and CDK8 activity in colon cancer cells. Effect of ellagic acid on viability of colon cancer cell lines (HT 29 and HCT 116, were assessed by MTT assay and its influence on CDK8, β-catenin, p-β-catenin, axin1 and 2, survivin, c-Myc and cyclin D1 expressions were determined by western blotting. The levels of survivin, c-Myc and cyclin D1 were also analysed following siCDK8 transfection. Ellagic acid caused significant decrease in viability of HT 29 and HCT 116 cells. Expression of CDK 8, β-catenin, survivin, c-Myc and cyclin D1were markedly reduced on exposure to ellagic acid. Significant up-regulation in the expression of p-β-catenin, axin1 and 2 were observed. siCDK8 transfection resulted in marked reduction in the expression of survivin, c-Myc and cyclin D1. Ellagic acid was able to effectively reduce cell viability and modulate expressions of Wnt/β-catenin signalling cascade proteins and down regulate the activity and expression of CDK8 in HT 29 and HCT 116 cells.

  9. Effect of Pulsed Electromagnetic Field on Bone Formation and Lipid Metabolism of Glucocorticoid-Induced Osteoporosis Rats through Canonical Wnt Signaling Pathway

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    Yuan Jiang

    2016-01-01

    Full Text Available Pulsed electromagnetic field (PEMF has been suggested as a promising method alternative to drug-based therapies for treating osteoporosis (OP, but the role of PEMF in GIOP animal models still remains unknown. This study was performed to investigate the effect of PEMF on bone formation and lipid metabolism and further explored the several important components and targets of canonical Wnt signaling pathway in GIOP rats. After 12 weeks of intervention, bone mineral density (BMD level of the whole body increased significantly, serum lipid levels decreased significantly, and trabeculae were thicker in GIOP rats of PEMF group. PEMF stimulation upregulated the mRNA and protein expression of Wnt10b, LRP5, β-catenin, OPG, and Runx2 and downregulated Axin2, PPAR-γ, C/EBPα, FABP4, and Dkk-1. The results of this study suggested that PEMF stimulation can prevent bone loss and improve lipid metabolism disorders in GIOP rats. Canonical Wnt signaling pathway plays an important role in bone formation and lipid metabolism during PEMF stimulation.

  10. Involvement of CDX2 in the cross talk between TNF-α and Wnt signaling pathway in the colon cancer cell line Caco-2

    DEFF Research Database (Denmark)

    Coskun, Mehmet; Olsen, Anders Krüger; Bzorek, Michael

    2014-01-01

    Tumor necrosis factor-α (TNF-α) is highly upregulated in inflammation and reduces the expression of the intestinal transcription factor, Caudal-related homeobox transcription factor 2 (CDX2). Wnt/β-catenin signaling is critical for intestinal cell proliferation, but a decreased CDX2 expression ha...... buddings in areas with TNF-α expression in the surrounding inflammatory cells. In vitro studies revealed that TNF-α treatment showed a dose-dependent decrease of CDX2 messenger RNA (mRNA) and protein expression in Caco-2 cells. Inhibition of nuclear factor-kappaB or p38 pathways showed...... targets were significantly elevated in TNF-α-treated Caco-2 cells. These findings were associated with reduced binding of CDX2 to promoter or enhancer regions of APC, AXIN2 and GSK3β. In conclusion, it was found that TNF-α induces the expression of Wnt signaling components through a downregulation...

  11. [Wnt signaling molecules related to osteoporosis].

    Science.gov (United States)

    Kubota, Takuo; Ozono, Keiichi

    2013-06-01

    Wnt signaling pathway components have been shown to be involved in bone biology since mutations in the LRP5 gene proved to cause osteoporosis-pseudoglioma syndrome and high bone mass trait. Genome wide association studies have indicated that single nucleotide polymorphisms of various components in Wnt signaling pathways are associated with bone mineral density and risk for low-trauma fracture. Mouse genetic studies have demonstrated that multiple components in Wnt signaling pathways play significant roles in skeletal development and bone mass maintenance. Here we review several components in Wnt signaling pathways with their association with bone mineral density in humans.

  12. Aldehyde dehydrogenase-2 protects against myocardial infarction-related cardiac fibrosis through modulation of the Wnt/β-catenin signaling pathway

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    Zhao XJ

    2015-09-01

    Full Text Available Xinjun Zhao,1,2,* Yue Hua,1,2,* Hongmei Chen,1,2,* Haiyu Yang,3,* Tao Zhang,1,2,* Guiqiong Huang,4,* Huijie Fan,1,2 Zhangbin Tan,1,2 Xiaofang Huang,1,2 Bin Liu,5 Yingchun Zhou1,21The Key Laboratory of Molecular Biology, State Administration of Traditional Chinese Medicine, School of Traditional Chinese Medicine, Southern Medical University, Guangdong, Guangzhou, People’s Republic of China; 2Nanfang Hospital, Southern Medical University, Guangdong, Guangzhou, People’s Republic of China; 3Jiangmen Wuyi Traditional Chinese Medicine Hospital, Guangdong, Jiangmen, People’s Republic of China; 4Huizhou Hospital of Traditional Chinese Medicine, Huizhou, People’s Republic of China; 5The Second Affiliated Hospital of Guangzhou Medical University, Guangdong, Guangzhou, People’s Republic of China*These authors contributed equally to this workBackground: Aldehyde dehydrogenase-2 (ALDH2 has a protective effect on ischemic heart disease. Here, we examined the protective effects of ALDH2 on cardiac fibrosis through modulation of the Wnt/ß-catenin signaling pathway in a rat model of myocardial infarction (MI.Methods: Wistar rats were divided into the sham (control, MI (model, and ALDH2 activator (Alda-1 groups. After 10 days of treatment, the left ventricular (LV remodeling parameters of each animal were evaluated by echocardiography. Myocardial fibrosis was evaluated by Masson’s trichrome staining and Sirius Red staining. Expression levels of collagen types I and III and β-smooth muscle actin (α-SMA were examined. Finally, the expression and activity of ALDH2 and the levels of several Wnt-related proteins and genes, such as phospho-glycogen synthase kinase (GSK-3β, GSK-3β, β-catenin, Wnt-1, WNT1-inducible signaling-pathway protein 1, and tumor necrosis factor (TNF-α, were also analyzed.Results: After MI, the heart weight/body weight ratio, LV dimension at end diastole, and LV dimension at end systole were decreased, while the LV ejection

  13. P-21-activated protein kinase-1 functions as a linker between insulin and Wnt signaling pathways in the intestine.

    Science.gov (United States)

    Sun, J; Khalid, S; Rozakis-Adcock, M; Fantus, I G; Jin, T

    2009-09-03

    Hyperinsulinemia and type II diabetes are associated with an increased risk of developing colorectal tumors. We found previously that in intestinal cells, insulin or insulin-like growth factor-1 stimulates c-Myc and cyclin D1 protein expression through both Akt-dependent and Akt-independent mechanisms. The effect of Akt is attributed to the stimulation of c-Myc translation by mammalian target of rapamycin. However, Akt-independent stimulation was, associated with an increase in beta-catenin (beta-cat) in the nucleus and an increased association between beta-cat and T-cell factor binding sites on the c-Myc promoter, detected by chromatin immunoprecipitation. In this study, we show that insulin stimulated the phosphorylation/activation of p-21-activated protein kinase-1 (PAK-1) in an Akt-independent manner in vitro and in an in vivo hyperinsulinemic mouse model. Significantly, shRNA (small hairpin RNA)-mediated PAK-1 knockdown attenuated both basal and insulin-stimulated c-Myc and cyclin D1 expression, associated with a marked reduction in extracellular signal-regulated kinase activation and beta-cat phosphorylation at Ser675. Furthermore, PAK-1 silencing led to a complete blockade of insulin-stimulated beta-cat binding to the c-Myc promoter and cellular growth. Finally, inhibition of MEK, a downstream target of PAK-1, blocked insulin-stimulated nuclear beta-cat accumulation and c-Myc expression. Our observations suggest that PAK-1 serves as an important linker between insulin and Wnt signaling pathways.

  14. Assessment of circulating Wnt1 inducible signalling pathway protein 1 (WISP-1)/CCN4 as a novel biomarker of obesity.

    Science.gov (United States)

    Tacke, Christopher; Aleksandrova, Krasimira; Rehfeldt, Miriam; Murahovschi, Veronica; Markova, Mariya; Kemper, Margrit; Hornemann, Silke; Kaiser, Ulrike; Honig, Caroline; Gerbracht, Christiana; Kabisch, Stefan; Hörbelt, Tina; Ouwens, D Margriet; Weickert, Martin O; Boeing, Heiner; Pfeiffer, Andreas F H; Pivovarova, Olga; Rudovich, Natalia

    2017-11-11

    WNT1 inducible signaling pathway protein 1 (WISP-1/CCN4) is a novel adipokine, which is upregulated in obesity, and induces a pro-inflammatory response in macrophages in-vitro. Preclinical observations suggested WISP-1/CCN4 as a potential candidate for novel obesity therapy targeting adipose tissue inflammation. Whether circulating levels of WISP-1/CCN4 in humans are altered in obesity and/or type 2 diabetes (T2DM) and in the postprandial state, however, is unknown. This study assessed circulating WISP-1/CCN4 levels in a) paired liquid meal tests and hyperinsulinemic- euglycemic clamps (cohort I, n = 26), b) healthy individuals (cohort II, n = 207) and c) individuals with different stages of obesity and glucose tolerance (cohort III, n = 253). Circulating plasma and serum WISP-1/CCN4 concentrations were measured using a commercially available ELISA. WISP-1/CCN4 levels were not influenced by changes in insulin and/or glucose during the tests. In healthy individuals, WISP-1/CCN4 was detectable in 13% of plasma samples with the intraclass correlation coefficient of 0.93 (95% CI: 0.84-0.96) and in 58.1% of the serum samples in cohort III. Circulating WISP-1/CCN4 positively correlated with body mass index, body fat percentage, leptin and triglyceride levels, hip circumference and fatty liver index. No differences in WISP-1/CCN4 levels between individuals with normal glucose tolerance, impaired glucose tolerance and T2DM were found. The circulating concentrations of WISP-1/CCN4 showed no acute regulation in postprandial state and correlated with anthropometrical obesity markers and lipid profiles. In healthy individuals, WISP-1/CCN4 levels are more often below the detection limit. Thus, serum WISP-1/CCN4 levels may be used as a suitable biomarker of obesity.

  15. Expression of Wnt/β-Catenin Signaling Pathway and Its Regulatory Role in Type I Collagen with TGF-β1 in Scleral Fibroblasts from an Experimentally Induced Myopia Guinea Pig Model

    Directory of Open Access Journals (Sweden)

    Min Li

    2016-01-01

    Full Text Available Background. To investigate Wnt/β-catenin signaling pathway expression and its regulation of type I collagen by TGF-β1 in scleral fibroblasts from form-deprivation myopia (FDM guinea pig model. Methods. Wnt isoforms were examined using genome microarrays. Scleral fibroblasts from FDM group and self-control (SC group were cultured. Wnt isoforms, β-catenin, TGF-β1, and type I collagen expression levels were examined in the two groups with or without DKK-1 or TGF-β1 neutralizing antibody. Results. For genome microarrays, the expression of Wnt3 in FDM group was significantly greater as confirmed in retinal and scleral tissue. The expression of Wnt3 and β-catenin significantly increased in FDM group and decreased significantly with DKK-1. TGF-β1 expression level decreased significantly in FDM group and increased significantly with DKK-1. Along with morphological misalignment inside and outside cells, the amount of type I collagen decreased in FDM group. Furthermore, type I collagen increased and became regular in DKK-1 intervention group, whereas it decreased and rearranged more disorder in TGF-β1 neutralizing antibody intervention group. Conclusions. The activation of Wnt3/β-catenin signaling pathway was demonstrated in primary scleral fibroblasts in FDM. This pathway further reduced the expression of type I collagen by TGF-β1, which ultimately played a role in scleral remodeling during myopia development.

  16. The Learning Festival: Pathway to Sustainable Learning Cities?

    Science.gov (United States)

    Kearns, Peter; Lane, Yvonne; Neylon, Tina; Osborne, Michael

    2013-01-01

    Cork and Limerick have conducted Lifelong Learning Festivals, Cork for ten years and Limerick for the past three years. This paper reviews aspects of this experience and considers the question of whether successful Lifelong Learning Festivals can be seen as a pathway to building sustainable learning cities. Discussed in the context of an…

  17. Ecosystem services for meeting sustainable development goals: Challenges and pathways

    Directory of Open Access Journals (Sweden)

    Huq Nazmul

    2015-01-01

    Full Text Available The paper summarizes four presentations of the session “Environment and Wellbeing: The Role of Ecosystems for Sustainable Development” at the international conference “Sustainability in the Water- Energy-Food Nexus” held on 19-20th May 2014 in Bonn, Germany. The aim of the session was to present current stresses on ecosystem services imposed by global development trajectory, potential impacts on future Sustainable Development Goals (SDGs and pathways to achieve SDGs. All four presentations agreed that global ecosystem services are under increasing pressure from degradation and may not be able to meet the growing Water-Energy-Food (WEF demands especially for the developing world. Three examples from Tanzania, Cambodia and Niger made attempt to understand how government policies attributed to natural resource depletion such as forestry and common grazing. The examples showed that institutional policies favoring economic development contributing heavily to clearing up natural resource bases. As a result, there were increasing conflicts among different resource user groups. Two other presentations introduce conceptual pathways to achieve the targets of Sustainable Development Goals (SDGs under current resource stressed regime. The pathways suggested global technologies, decentralized solutions and consumption changes as the major means of achieving global sustainability and poverty eradication without any major trade-offs.

  18. Ecosystem services for meeting sustainable development goals: Challenges and pathways

    Directory of Open Access Journals (Sweden)

    Huq Nazmul

    2015-01-01

    Full Text Available The paper summarizes four presentations of the session “Environment and Wellbeing: The Role of Ecosystems for Sustainable Development” at the international conference “Sustainability in the Water- Energy-Food Nexus” held on 19-20th May 2014 in Bonn, Germany. The aim of the session was to present current stresses on ecosystem services imposed by global development trajectory, potential impacts on Sustainable Development Goals (SDGs and pathways to achieve SDGs. All four presentations agreed that global ecosystem services are under increasing pressure from degradation and may not be able to meet the growing Water-Energy- Food (WEF demands especially for the developing world. Three examples from Tanzania, Cambodia and Niger made attempt to understand how governance policies attributed to natural resource depletion such as forestry and common grazing. The examples showed that governance policies favoring economic development are heavily contributing to clearing up natural resource bases. As a result, there were increasing conflicts among different resource user groups. Two other presentations introduce conceptual pathways to achieve the targets of Sustainable Development Goals (SDGs under current resource stressed regime. The pathways suggested global technologies, decentralized solutions and consumption changes as the major means of achieving global sustainability and poverty eradication without any major trade-offs.

  19. Polycyclic aromatic hydrocarbons and dibutyl phthalate disrupt dorsal-ventral axis determination via the Wnt/{beta}-catenin signaling pathway in zebrafish embryos

    Energy Technology Data Exchange (ETDEWEB)

    Fairbairn, Elise A., E-mail: efairbairn@ucdavis.edu [University of California Davis, Bodega Marine Laboratory, P.O. Box 247, Bodega Bay, CA 94923 (United States); Bonthius, Jessica, E-mail: jessica.bonthius@gmail.com [University of California Davis, Bodega Marine Laboratory, P.O. Box 247, Bodega Bay, CA 94923 (United States); Cherr, Gary N., E-mail: gncherr@ucdavis.edu [University of California Davis, Bodega Marine Laboratory, P.O. Box 247, Bodega Bay, CA 94923 (United States); Department of Environmental Toxicology, University of California Davis, Davis, CA 95616 (United States); Department of Nutrition, University of California Davis, Davis, CA 95616 (United States)

    2012-11-15

    The canonical Wnt/{beta}-catenin signaling pathway is critical during early teleost development for establishing the dorsal-ventral axis. Within this pathway, GSK-3{beta}, a key regulatory kinase in the Wnt pathway, regulates {beta}-catenin degradation and thus the ability of {beta}-catenin to enter nuclei, where it can activate expression of genes that have been linked to the specification of the dorsal-ventral axis. In this study, we describe the morphological abnormalities that resulted in zebrafish embryos when axis determination was disrupted by environmental contaminants. These abnormalities were linked to abnormal nuclear accumulation of {beta}-catenin. Furthermore, we demonstrated that the developmental abnormalities and altered nuclear {beta}-catenin accumulation occurred when embryos were exposed to commercial GSK-3{beta} inhibitors. Zebrafish embryos were exposed to commercially available GSK-3 inhibitors (GSK-3 Inhibitor IX and 1-azakenpaullone), or common environmental contaminants (dibutyl phthalate or the polycyclic aromatic hydrocarbons phenanthrene and fluorene) from the 2 to 8-cell stage through the mid-blastula transition (MBT). These embryos displayed morphological abnormalities at 12.5 h post-fertilization (hpf) that were comparable to embryos exposed to lithium chloride (LiCl) (300 mM LiCl for 10 min, prior to the MBT), a classic disruptor of embryonic axis determination. Whole-mount immunolabeling and laser scanning confocal microscopy were used to localize {beta}-catenin. The commercial GSK-3 Inhibitors as well as LiCl, dibutyl phthalate, fluorene and phenanthrene all induced an increase in the levels of nuclear {beta}-catenin throughout the embryo, indicating that the morphological abnormalities were a result of disruption of Wnt/{beta}-catenin signaling during dorsal-ventral axis specification. The ability of environmental chemicals to directly or indirectly target GSK-3{beta} was assessed. Using Western blot analysis, the ability of these

  20. Raloxifene pharmacodynamics is influenced by genetic variants in the RANKL/RANK/OPG system and in the Wnt signaling pathway.

    Science.gov (United States)

    Mencej-Bedrač, Simona; Zupan, Janja; Mlakar, Simona Jurković; Zavratnik, Andrej; Preželj, Janez; Marc, Janja

    2014-01-01

    Raloxifene is a selective estrogen receptor (ER) modulator (SERM) used for the treatment of osteoporosis. However, its efficacy and also its safety vary greatly among treated patients, and it might be influenced by the individuals' genetic background. As the receptor activator of the nuclear factor κB (RANK) ligand (RANKL)/RANK/osteoprotegerin (OPG) system is essential for osteoclastogensis and Wnt signaling pathway for osteoblastogenesis, we decided to evaluate the raloxifene treatment in regard to selected polymorphisms in key genes of these two main bone regulatory pathways. Fifty-six osteoporotic postmenopausal women treated with raloxifene were genotyped for 11 polymorphisms located in six genes: -290C>T, -643C>T, and -693G>C in tumor necrosis factor receptor superfamily member 11 (TNFSF11), +34694C>T, +34901G>A, and +35966insdelC in tumor necrosis factor receptor superfamily member 11A (TNFRSF11A), K3N and 245T>G in tumor necrosis factor receptor superfamily member 11B (TNFRSF11B), A1330V in LRP5, I1062V in LRP6, and -1397_-1396insGGA in SOST. For evaluation of treatment efficacy, bone mineral density (BMD) and biochemical markers of bone turnover were measured. One-year change in total hip BMD was associated with +34901G>A in TNFRSF11A (p=0.040), whereas, for lumbar spine BMD, the association was shown for -1397_-1396insGGA in SOST (p=0.015). C-terminal crosslinking telopeptides of type I collagen (CTX) concentrations showed significant association with -643C>T single nucleotide polymorphism (SNP) in TNFSF11 (p=0.049) and +34694C>T in TNFRSF11A (p=0.022). No other association was found between 1-year change in BMDs or biochemical markers and the studied SNPs. We have shown that, in postmenopausal osteoporotic women treated with raloxifene, the efficacy of raloxifene treatment might be influenced by +34901G>A in TNFRSF11A gene and -1397_-1396insGGA in the SOST gene as well as -643C>T in TNFSF11 gene and +34694C>T in TNFRSF11A gene. However, these findings

  1. Fresh WNT into the regulation of mitosis.

    Science.gov (United States)

    Stolz, Ailine; Bastians, Holger

    2015-01-01

    Canonical Wnt signaling triggering β-catenin-dependent gene expression contributes to cell cycle progression, in particular at the G1/S transition. Recently, however, it became clear that the cell cycle can also feed back on Wnt signaling at the G2/M transition. This is illustrated by the fact that mitosis-specific cyclin-dependent kinases can phosphorylate the Wnt co-receptor LRP6 to prime the pathway for incoming Wnt signals when cells enter mitosis. In addition, there is accumulating evidence that various Wnt pathway components might exert additional, Wnt-independent functions that are important for proper regulation of mitosis. The importance of Wnt pathways during mitosis was most recently enforced by the discovery of Wnt signaling contributing to the stabilization of proteins other than β-catenin, specifically at G2/M and during mitosis. This Wnt-mediated stabilization of proteins, now referred to as Wnt/STOP, might on one hand contribute to maintaining a critical cell size required for cell division and, on the other hand, for the faithful execution of mitosis itself. In fact, most recently we have shown that Wnt/STOP is required for ensuring proper microtubule dynamics within mitotic spindles, which is pivotal for accurate chromosome segregation and for the maintenance of euploidy.

  2. Lawsonia intracellularis exploits β-catenin/Wnt and Notch signalling pathways during infection of intestinal crypt to alter cell homeostasis and promote cell proliferation.

    Directory of Open Access Journals (Sweden)

    Yang W Huan

    Full Text Available Lawsonia intracellularis is an obligate intracellular bacterial pathogen that causes proliferative enteropathy (PE in pigs. L. intracellularis infection causes extensive intestinal crypt cell proliferation and inhibits secretory and absorptive cell differentiation. However, the affected host upstream cellular pathways leading to PE are still unknown. β-catenin/Wnt signalling is essential in maintaining intestinal stem cell (ISC proliferation and self-renewal capacity, while Notch signalling governs differentiation of secretory and absorptive lineage specification. Therefore, in this report we used immunofluorescence (IF and quantitative reverse transcriptase PCR (RTqPCR to examine β-catenin/Wnt and Notch-1 signalling levels in uninfected and L. intracellularis infected pig ileums at 3, 7, 14, 21 and 28 days post challenge (dpc. We found that while the significant increase in Ki67+ nuclei in crypts at the peak of L. intracellularis infection suggested enhanced cell proliferation, the expression of c-MYC and ASCL2, promoters of cell growth and ISC proliferation respectively, was down-regulated. Peak infection also coincided with enhanced cytosolic and membrane-associated β-catenin staining and induction of AXIN2 and SOX9 transcripts, both encoding negative regulators of β-catenin/Wnt signalling and suggesting a potential alteration to β-catenin/Wnt signalling levels, with differential regulation of the expression of its target genes. We found that induction of HES1 and OLFM4 and the down-regulation of ATOH1 transcript levels was consistent with the increased Notch-1 signalling in crypts at the peak of infection. Interestingly, the significant down-regulation of ATOH1 transcript levels coincided with the depletion of MUC2 expression at 14 dpc, consistent with the role of ATOH1 in promoting goblet cell maturation. The lack of significant change to LGR5 transcript levels at the peak of infection suggested that the crypt hyperplasia was not due

  3. Lawsonia intracellularis exploits β-catenin/Wnt and Notch signalling pathways during infection of intestinal crypt to alter cell homeostasis and promote cell proliferation.

    Science.gov (United States)

    Huan, Yang W; Bengtsson, Rebecca J; MacIntyre, Neil; Guthrie, Jack; Finlayson, Heather; Smith, Sionagh H; Archibald, Alan L; Ait-Ali, Tahar

    2017-01-01

    Lawsonia intracellularis is an obligate intracellular bacterial pathogen that causes proliferative enteropathy (PE) in pigs. L. intracellularis infection causes extensive intestinal crypt cell proliferation and inhibits secretory and absorptive cell differentiation. However, the affected host upstream cellular pathways leading to PE are still unknown. β-catenin/Wnt signalling is essential in maintaining intestinal stem cell (ISC) proliferation and self-renewal capacity, while Notch signalling governs differentiation of secretory and absorptive lineage specification. Therefore, in this report we used immunofluorescence (IF) and quantitative reverse transcriptase PCR (RTqPCR) to examine β-catenin/Wnt and Notch-1 signalling levels in uninfected and L. intracellularis infected pig ileums at 3, 7, 14, 21 and 28 days post challenge (dpc). We found that while the significant increase in Ki67+ nuclei in crypts at the peak of L. intracellularis infection suggested enhanced cell proliferation, the expression of c-MYC and ASCL2, promoters of cell growth and ISC proliferation respectively, was down-regulated. Peak infection also coincided with enhanced cytosolic and membrane-associated β-catenin staining and induction of AXIN2 and SOX9 transcripts, both encoding negative regulators of β-catenin/Wnt signalling and suggesting a potential alteration to β-catenin/Wnt signalling levels, with differential regulation of the expression of its target genes. We found that induction of HES1 and OLFM4 and the down-regulation of ATOH1 transcript levels was consistent with the increased Notch-1 signalling in crypts at the peak of infection. Interestingly, the significant down-regulation of ATOH1 transcript levels coincided with the depletion of MUC2 expression at 14 dpc, consistent with the role of ATOH1 in promoting goblet cell maturation. The lack of significant change to LGR5 transcript levels at the peak of infection suggested that the crypt hyperplasia was not due to the expansion

  4. MiR-129-5p Inhibits Proliferation and Invasion of Chondrosarcoma Cells by Regulating SOX4/Wnt/β-Catenin Signaling Pathway.

    Science.gov (United States)

    Zhang, Peng; Li, Jifeng; Song, Yuze; Wang, Xiao

    2017-01-01

    Recently, microRNAs (miRNA) have been identified as novel regulators in Chondrosarcoma (CHS). This study was aimed to identify the roles of miR-129-5p-5p in regulation of SOX4 and Wnt/β-catenin signaling pathway, as well as cell proliferation and apoptosis in chondrosarcomas. Tissue samples were obtained from chondrosarcoma patients. Immunohistochemistry, real-time quantitative RT-PCR (RT-qPCR) and western blot analysis were performed to detect the expressions of miR-129-5p and SOX4. Luciferase assay was conducted to confirm that miR-129-5p directly targeted SOX4 mRNA. Manipulations of miR-129-5p and SOX4 expression were achieved through cell transfection. Cell proliferation, migration and apoptosis were evaluated by CCK-8 assay, colony forming assay, wound healing assay and flow cytometry in vitro. For in vivo experiment, the tumor xenograft model was established to evaluate the effects of miR-129-5p and SOX4 on chondrosarcomas. The expression of miR-129-5p was significantly down-regulated in chondrosarcoma tissues as well as cells in comparison with normal ones, while SOX4 was over-activated. Further studies suggested that miR-129-5p suppressed cell proliferation, migration and promoted apoptosis by inhibiting SOX4 and Wnt/β-catenin pathway. MiR-129-5p inhibits the Wnt/β-catenin signaling pathway by targeting SOX4 and further suppresses cell proliferation, migration and promotes apoptosis in chondrosarcomas. © 2017 The Author(s). Published by S. Karger AG, Basel.

  5. Results of a phase I pilot clinical trial examining the effect of plant-derived resveratrol and grape powder on Wnt pathway target gene expression in colonic mucosa and colon cancer

    Directory of Open Access Journals (Sweden)

    Anthony V Nguyen

    2009-04-01

    Full Text Available Anthony V Nguyen1, Micaela Martinez1, Michael J Stamos2, Mary P Moyer3, Kestutis Planutis1, Christopher Hope1 Randall F Holcombe11Division of Hematology/Oncology and Chao Family Comprehensive Cancer Center, 2Department of Surgery, University of California, Irvine CA, USA; 3Incell Corporation, San Antonio, TX USAContext: Resveratrol exhibits colon cancer prevention activity in animal models; it is purported to have this activity in humans and inhibit a key signaling pathway involved in colon cancer initiation, the Wnt pathway, in vitro.Design: A phase I pilot study in patients with colon cancer was performed to evaluate the effects of a low dose of plant-derived resveratrol formulation and resveratrol-containing freeze-dried grape powder (GP on Wnt signaling in the colon. Eight patients were enrolled and normal colonic mucosa and colon cancer tissue were evaluated by Wnt pathway-specific microarray and quantitative real-time polymerase chain reaction (qRT-PCR pre- and post-exposure to resveratrol/GP.Results: Based on the expression of a panel of Wnt target genes, resveratrol/GP did not inhibit the Wnt pathway in colon cancer but had significant (p < 0.03 activity in inhibiting Wnt target gene expression in normal colonic mucosa. The greatest effect on Wnt target gene expression was seen following ingestion of 80 g of GP per day (p < 0.001. These results were confirmed with qRT-PCR of cyclinD1 and axinII. The inhibitory effect of GP on Wnt signal throughput was confirmed in vitro with a normal colonic mucosa-derived cell line.Conclusions: These data suggest that GP, which contains low dosages of resveratrol in combination with other bioactive components, can inhibit the Wnt pathway in vivo and that this effect is confined to the normal colonic mucosa. Further study of dietary supplementation with resveratrol-containing foods such as whole grapes or GP as a potential colon cancer preventive strategy is warranted.Trial registration: NCT00256334

  6. High-fat diet induced leptin and Wnt expression: RNA-sequencing and pathway analysis of mouse colonic tissue and tumors.

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    Penrose, Harrison M; Heller, Sandra; Cable, Chloe; Nakhoul, Hani; Baddoo, Melody; Flemington, Erik; Crawford, Susan E; Savkovic, Suzana D

    2017-03-01

    Obesity, an immense epidemic affecting approximately half a billion adults, has doubled in prevalence in the last several decades. Epidemiological data support that obesity, due to intake of a high-fat, western diet, increases the risk of colon cancer; however, the mechanisms underlying this risk remain unclear. Here, utilizing next generation RNA sequencing, we aimed to determine the high-fat diet (HFD) mediated expression profile in mouse colon and the azoxymethane/dextran sulfate sodium model of colon cancer. Mice on HFD had significantly higher colonic inflammation, tumor burden, and a number of differentially expressed transcripts compared to mice on regular diet (RD). We identified 721 transcripts differentially expressed in mouse HFD colon that were in a shared pattern with colonic tumors (RD and HFD). Importantly, in mouse colon, HFD stimulated an expression signature strikingly similar to human colon cancer, especially those with inflammatory microsatellite instability. Furthermore, pathway analysis of these transcripts demonstrated their association with active inflammation and colon cancer signaling, with leptin and Wnt as the top two transcripts elevated in mouse HFD colon shared with tumors. Moreover, in mouse colon, HFD-stimulated tumorigenic Wnt pathway activation was further validated by upregulation of β-catenin transcriptional targets. Finally, in human colon cancer, upregulation of leptin pathway members was shown with a large network of dysregulated transcripts being linked with worse overall survival. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. c-Myb Enhances Breast Cancer Invasion and Metastasis through the Wnt/β-Catenin/Axin2 Pathway.

    Science.gov (United States)

    Li, Yihao; Jin, Ke; van Pelt, Gabi W; van Dam, Hans; Yu, Xiao; Mesker, Wilma E; Ten Dijke, Peter; Zhou, Fangfang; Zhang, Long

    2016-06-01

    The molecular underpinnings of aggressive breast cancers remain mainly obscure. Here we demonstrate that activation of the transcription factor c-Myb is required for the prometastatic character of basal breast cancers. An analysis of breast cancer patients led us to identify c-Myb as an activator of Wnt/β-catenin signaling. c-Myb interacted with the intracellular Wnt effector β-catenin and coactivated the Wnt/β-catenin target genes Cyclin D1 and Axin2 Moreover, c-Myb controlled metastasis in an Axin2-dependent manner. Expression microarray analyses revealed a positive association between Axin2 and c-Myb, a target of the proinflammatory cytokine IL1β that was found to be required for IL1β-induced breast cancer cell invasion. Overall, our results identified c-Myb as a promoter of breast cancer invasion and metastasis through its ability to activate Wnt/β-catenin/Axin2 signaling. Cancer Res; 76(11); 3364-75. ©2016 AACR. ©2016 American Association for Cancer Research.

  8. Inhibitory effect 6-gingerol on adipogenesis through activation of the Wnt/β-catenin signaling pathway in 3T3-L1 adipocytes.

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    Li, Chunbo; Zhou, Lin

    2015-12-25

    6-Gingerol has been reported to inhibit adipogenesis and lipid content accumulation. However, the mechanism of its anti-adipogenic effect remains unclear. Our aim is to investigate the molecular mechanism of the anti-adipogenic effect of 6-gingerol. The lipid content in adipocytes was measured by Oil Red O staining and cell viability was analyzed by MTT assay. The extent of suppression of differentiation by 6-gingerol was characterized by measuring the triglyceride content and GPDH activity. The regulation of adipogenic markers and the components of the Wnt/β-catenin pathway were analyzed by real-time PCR and Western blotting. The nuclear location of β-catenin was identified using immunofluorescence assay. Small interfering RNA transfection was conducted to elucidate the crucial role of β-catenin in anti-adipogenic effect of 6-gingerol. Our results showed that 6-gingerol inhibited the adipogenesis and lowered the mRNA expression levels of transcription factors and the key lipogenic enzymes in 3T3-L1 cells. The effect of 6-gingerol on adipogenic differentiation was accompanied by stimulating the activation of the Wnt/β-catenin signaling. In addition, we found that 6-gingerol induced phosphorylations of glycogen synthase kinase-3β(GSK-3β), and promoted the nuclear accumulation of β-catenin. Importantly, the inhibitory effect of 6-gingerol on adipogenic differentiation was reversed after the siRNA knockdown of β-catenin was added. Our findings demonstrated that 6-gingerol inhibits the adipogenic differentiation of 3T3-L1 cells through activating the Wnt/β-catenin signaling pathway. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. ATF3 promotes migration and M1/M2 polarization of macrophages by activating tenascin‑C via Wnt/β‑catenin pathway.

    Science.gov (United States)

    Sha, Hao; Zhang, Dianzhong; Zhang, Yunfei; Wen, Yanhua; Wang, Yucai

    2017-09-01

    There are different polarization states of macrophages, including the classically activated M1 phenotype and the alternatively activated M2 phenotype. These have different functions in the inflammation process. Activating transcription factor 3 (ATF3) is a key transcriptional regulator that inhibits the inflammatory response. However, the effects of ATF3 on migration and anti‑inflammatory control mechanisms of macrophages have not been thoroughly investigated. The present study investigated the effect of ATF3 on macrophage migration and M1/M2 polarization. Results revealed that overexpression of ATF3 promoted macrophage migration and the expression of the M2 phenotype markers [cluster of differentiation (CD) 163, mannose receptor C type 1, arginase 1 and peroxisome proliferator‑activated receptor γ] and inhibited expression of the M1 phenotype markers (monocyte chemoattractant protein‑1, inducible nitric oxide synthase, CD16 and tumor necrosis factor‑α), whereas knockdown of ATF3 resulted in a contrary effect. In addition, the wingless‑type MMTV integration site family member (Wnt)/β‑catenin signaling pathway was activated and the expression level of tenascin (TNC) was significantly upregulated by overexpression of ATF3. Additionally, inhibition of Wnt/β‑catenin signaling significantly attenuated the upregulatory effect of ATF3 on TNC. Finally, the effect of ATF3 on macrophage migration and markers of the M1 or M2 state was investigated using TNC‑specific siRNA. In conclusion, the results of the present study suggested that ATF3 promotes macrophage migration and reverses M1‑polarized macrophages to the M2 phenotype by upregulation of TNC via the Wnt/β‑catenin signaling pathway.

  10. Activating the Wnt/β-Catenin Pathway for the Treatment of Melanoma--Application of LY2090314, a Novel Selective Inhibitor of Glycogen Synthase Kinase-3.

    Directory of Open Access Journals (Sweden)

    Jennifer M Atkinson

    Full Text Available It has previously been observed that a loss of β-catenin expression occurs with melanoma progression and that nuclear β-catenin levels are inversely proportional to cellular proliferation, suggesting that activation of the Wnt/β-catenin pathway may provide benefit for melanoma patients. In order to further probe this concept we tested LY2090314, a potent and selective small-molecule inhibitor with activity against GSK3α and GSK3β isoforms. In a panel of melanoma cell lines, nM concentrations of LY2090314 stimulated TCF/LEF TOPFlash reporter activity, stabilized β-catenin and elevated the expression of Axin2, a Wnt responsive gene and marker of pathway activation. Cytotoxicity assays revealed that melanoma cell lines are very sensitive to LY2090314 in vitro (IC50 ~10 nM after 72hr of treatment in contrast to other solid tumor cell lines (IC50 >10 uM as evidenced by caspase activation and PARP cleavage. Cell lines harboring mutant B-RAF or N-RAS were equally sensitive to LY2090314 as were those with acquired resistance to the BRAF inhibitor Vemurafenib. shRNA studies demonstrated that β-catenin stabilization is required for apoptosis following treatment with the GSK3 inhibitor since the sensitivity of melanoma cell lines to LY290314 could be overcome by β-catenin knockdown. We further demonstrate that in vivo, LY2090314 elevates Axin2 gene expression after a single dose and produces tumor growth delay in A375 melanoma xenografts with repeat dosing. The activity of LY2090314 in preclinical models suggests that the role of Wnt activators for the treatment of melanoma should be further explored.

  11. BMP and TGF-β pathway mediators are critical upstream regulators of Wnt signaling during midbrain dopamine differentiation in human pluripotent stem cells.

    Science.gov (United States)

    Cai, Jingli; Schleidt, Stephanie; Pelta-Heller, Joshua; Hutchings, Danielle; Cannarsa, Gregory; Iacovitti, Lorraine

    2013-04-01

    Although many laboratories currently use small molecule inhibitors of the BMP (Dorsomorphin/DM) and TGF-β (SB431542/SB) signaling pathways in protocols to generate midbrain dopamine (mDA) neurons from hES and hiPS cells, until now, these substances have not been thought to play a role in the mDA differentiation process. We report here that the transient inhibition of constitutive BMP (pSMADs 1, 5, 8) signaling, either alone or in combination with TGF-β inhibition (pSMADs 2, 3), is critically important in the upstream regulation of Wnt1-Lmx1a signaling in mDA progenitors. We postulate that the mechanism via which DM or DM/SB mediates these effects involves the up-regulation in SMAD-interacting protein 1 (SIP1), which results in greater repression of the Wnt antagonist, secreted frizzled related protein 1 (Sfrp1) in stem cells. Accordingly, knockdown of SIP1 reverses the inductive effects of DM/SB on mDA differentiation while Sfrp1 knockdown/inhibition mimics DM/SB. The rise in Wnt1-Lmx1a levels in SMAD-inhibited cultures is, however, accompanied by a reciprocal down-regulation in SHH-Foxa2 levels leading to the generation of few TH+ neurons that co-express Foxa2. If however, exogenous SHH/FGF8 is added along with SMAD inhibitors, equilibrium in these two important pathways is achieved such that authentic (Lmx1a+Foxa2+TH+) mDA neuron differentiation is promoted while alternate cell fates are suppressed in stem cell cultures. These data indicate that activators/inhibitors of BMP and TGF-β signaling play a critical upstream regulatory role in the mDA differentiation process in human pluripotent stem cells. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. [Effect of StarD7 and Wnt/β-catenin signal pathway on the testosterone secretion stimulated by Annexin 5 in rat Leydig cells].

    Science.gov (United States)

    Fu, Hai-yan; Jing, Jun; Yi, Nan; Yu, Shi-chao; Yun, Shi-feng; Liang, Yuan-jiao; Yao, Bing

    2012-08-18

    This research aims to study the internal mechanism that promotes the testosterone synthesis by StarD7 and Wnt/β-catenin, and explores a new regulatory pathway of testosterone synthesis. After treated with 1 nmol/L Annexin 5 for 24 h, the culture media were collected for testosterone measurement by chemiluminescence assay. The expressions of StarD7 and β-catenin at mRNA and protein levels were detected by RT-PCR and western blot respectively. The cellular location of β-catenin was identified by immunofluorescence. Comparing with the control groups, under the treatment with Annexin 5, the level of testosterone raised 176%[(7.83±0.32)vs.(21.6±1.1), Ptestosterone production of rat Leydig cells. This regulation may active the Wnt/β-catenin signal pathway, then increase the expression of the StarD7, eventually raise the progress of the testosterone secretion in rat Leydig cells.

  13. SOX 1, contrary to SOX 2, suppresses proliferation, migration, and invasion in human laryngeal squamous cell carcinoma by inhibiting the Wnt/β-catenin pathway.

    Science.gov (United States)

    Yang, Ning; Wang, Yan; Hui, Lian; Li, Xiaotian; Jiang, Xuejun

    2015-11-01

    Sex-determining region Y (SRY)-box protein 1 (SOX 1) has been reported to have the inhibiting effects on various cancer cells; however, the expression and effect of SOX 1 on laryngeal squamous cell carcinoma (LSCC) have not been determined. Therefore, the aim of this study was to assess the anti-proliferation and metastatic effects of SOX 1 and its related mechanisms on LSCC. According to our present study, first, we found that overexpression of SOX 1 could significantly inhibit proliferation and promote apoptosis in Tu212 cells. Additionally, overexpression of SOX 1 suppressed the migration and invasion potential of Tu212 cells via regulating Wnt/β-catenin pathway. Finally, we demonstrated for the first time that overexpression of SOX 1 could downregulate the expression of SOX 2, and co-expression of SOX 1 and SOX 2 could reverse the anti-tumor effect of SOX 1. In conclusion, our studies suggested that SOX 1 suppressed cell growth and invasion in Tu212 cells by inhibiting Wnt/β-catenin pathway, and the anti-tumor effect of SOX 1 could be weakened by SOX 2, which may be a potential molecular basis for clinical treatment of LSCC.

  14. Computational Biophysical, Biochemical, and Evolutionary Signature of Human R-Spondin Family Proteins, the Member of Canonical Wnt/β-Catenin Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Ashish Ranjan Sharma

    2014-01-01

    Full Text Available In human, Wnt/β-catenin signaling pathway plays a significant role in cell growth, cell development, and disease pathogenesis. Four human (Rspos are known to activate canonical Wnt/β-catenin signaling pathway. Presently, (Rspos serve as therapeutic target for several human diseases. Henceforth, basic understanding about the molecular properties of (Rspos is essential. We approached this issue by interpreting the biochemical and biophysical properties along with molecular evolution of (Rspos thorough computational algorithm methods. Our analysis shows that signal peptide length is roughly similar in (Rspos family along with similarity in aa distribution pattern. In Rspo3, four N-glycosylation sites were noted. All members are hydrophilic in nature and showed alike GRAVY values, approximately. Conversely, Rspo3 contains the maximum positively charged residues while Rspo4 includes the lowest. Four highly aligned blocks were recorded through Gblocks. Phylogenetic analysis shows Rspo4 is being rooted with Rspo2 and similarly Rspo3 and Rspo1 have the common point of origin. Through phylogenomics study, we developed a phylogenetic tree of sixty proteins (n=60 with the orthologs and paralogs seed sequences. Protein-protein network was also illustrated. Results demonstrated in our study may help the future researchers to unfold significant physiological and therapeutic properties of (Rspos in various disease models.

  15. Wnt5a Signaling in Cancer

    Directory of Open Access Journals (Sweden)

    Marwa S. Asem

    2016-08-01

    Full Text Available Wnt5a is involved in activating several non-canonical WNT signaling pathways, through binding to different members of the Frizzled- and Ror-family receptors. Wnt5a signaling is critical for regulating normal developmental processes, including proliferation, differentiation, migration, adhesion and polarity. However, the aberrant activation or inhibition of Wnt5a signaling is emerging as an important event in cancer progression, exerting both oncogenic and tumor suppressive effects. Recent studies show the involvement of Wnt5a in regulating cancer cell invasion, metastasis, metabolism and inflammation. In this article, we review findings regarding the molecular mechanisms and roles of Wnt5a signaling in various cancer types, and highlight Wnt5a in ovarian cancer.

  16. Celecoxib Ameliorates Non-Alcoholic Steatohepatitis in Type 2 Diabetic Rats via Suppression of the Non-Canonical Wnt Signaling Pathway Expression

    Science.gov (United States)

    Tian, Feng; Zhang, Ya Jie; Li, Yu; Xie, Ying

    2014-01-01

    Our aim was to test whether pharmacological inhibition of cycloxygenase-2 (COX-2) reverses non-alcoholic steatohepatitis (NASH) in type 2 diabetes mellitus (T2DM) rats via suppression of the non-canonical Wnt signaling pathway expression. Twenty-four male Sprague-Dawley rats were randomly distributed to two groups and were fed with a high fat and sucrose (HF-HS) diet or a normal chow diet, respectively. After four weeks, rats fed with a HF-HS diet were made diabetic with low-dose streptozotocin. At the 9th week the diabetic rats fed with a HF-HS diet or the non-diabetic rats fed with a normal chow diet were further divided into two subgroups treated with vehicle or celecoxib (a selective COX-2 inhibitor, 10 mg/Kg/day, gavage) for the last 4 weeks, respectively. At the end of the 12th week, rats were anesthetized. NASH was assessed by histology. Related cytokine expression was measured at both the protein and gene levels through immunohistochemistry (IHC), Western blot and real-time PCR. T2DM rats fed with a HF-HS diet developed steatohepatitis and insulin resistance associated with elevated serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), insulin levels and the non-alcoholic fatty liver disease (NAFLD) activity score (NAS). The expression of Wnt5a, JNK1, NF-κB p65, and COX-2 were all significantly increased in the T2DM-NASH group compared with the control and control-cele group. Hepatic injury was improved by celecoxib in T2DM-NASH-Cele group indicated by reduced serum ALT and AST levels and hepatic inflammation was reduced by celecoxib showed by histology and the NAFLD activity score (NAS). Serum related metabolic parameters, HOMA-IR and insulin sensitivity index were all improved by celecoxib. The expression of Wnt5a, JNK1, NF-κB p65, and COX-2 expression were all suppressed by celecoxib in T2DM-NASH-Cele group. The results of the present study indicated that celecoxib ameliorated NASH in T2DM rats via suppression of the non-canonical Wnt

  17. Role of GSK-3β in Regulation of Canonical Wnt/β-catenin Signaling and PI3-K/Akt Oncogenic Pathway in Colon Cancer.

    Science.gov (United States)

    Jain, Shelly; Ghanghas, Preety; Rana, Chandan; Sanyal, S N

    2017-08-09

    Non-steroidal anti-inflammatory drugs (NSAIDs) are emerging as novel chemopreventive agents because of their ability in blocking cellular proliferation, and thereby tumor development, and also by promoting apoptosis. GSK-3β, a serine threonine kinase and a negative regulator of the oncogenic Wnt/β-catenin signaling pathway, plays a critical role in the regulation of oncogenesis. Celecoxib and etoricoxib, the two cyclooxygenase-2 (COX-2) selective NSAIDs, and Diclofenac, a preferential COX-2 inhibitory NSAID, had shown uniformly the chemopreventive and anti-neoplastic effects in the early stage of colon cancer by promoting apoptosis as well as an over-expression of GSK-3β while down-regulating the PI3-K/Akt oncogenic pathway.

  18. Leptin-induced Epithelial-Mesenchymal Transition in Breast Cancer Cells Requires β-Catenin Activation via Akt/GSK3- and MTA1/Wnt1 Protein-dependent Pathways*

    Science.gov (United States)

    Yan, Dan; Avtanski, Dimiter; Saxena, Neeraj K.; Sharma, Dipali

    2012-01-01

    Perturbations in the adipocytokine profile, especially higher levels of leptin, are a major cause of breast tumor progression and metastasis; the underlying mechanisms, however, are not well understood. In particular, it remains elusive whether leptin is involved in epithelial-mesenchymal transition (EMT). Here, we provide molecular evidence that leptin induces breast cancer cells to undergo a transition from epithelial to spindle-like mesenchymal morphology. Investigating the downstream mediator(s) that may direct leptin-induced EMT, we found functional interactions between leptin, metastasis-associated protein 1 (MTA1), and Wnt1 signaling components. Leptin increases accumulation and nuclear translocation of β-catenin leading to increased promoter recruitment. Silencing of β-catenin or treatment with the small molecule inhibitor, ICG-001, inhibits leptin-induced EMT, invasion, and tumorsphere formation. Mechanistically, leptin stimulates phosphorylation of glycogen synthase kinase 3β (GSK3β) via Akt activation resulting in a substantial decrease in the formation of the GSK3β-LKB1-Axin complex that leads to increased accumulation of β-catenin. Leptin treatment also increases Wnt1 expression that contributes to GSK3β phosphorylation. Inhibition of Wnt1 abrogates leptin-stimulated GSK3β phosphorylation. We also discovered that leptin increases the expression of an important modifier of Wnt1 signaling, MTA1, which is integral to leptin-mediated regulation of the Wnt/β-catenin pathway as silencing of MTA1 inhibits leptin-induced Wnt1 expression, GSK3β phosphorylation, and β-catenin activation. Furthermore, analysis of leptin-treated breast tumors shows increased expression of Wnt1, pGSK3β, and vimentin along with higher nuclear accumulation of β-catenin and reduced E-cadherin expression providing in vivo evidence for a previously unrecognized cross-talk between leptin and MTA1/Wnt signaling in epithelial-mesenchymal transition of breast cancer cells. PMID

  19. Retinoids Regulate Adipogenesis Involving the TGFβ/SMAD and Wnt/β-Catenin Pathways in Human Bone Marrow Mesenchymal Stem Cells.

    Science.gov (United States)

    Cao, Jun; Ma, Yuhong; Yao, Weiqi; Zhang, Xiaoye; Wu, Dongcheng

    2017-04-15

    Retinoids may regulate cell differentiation as ligands of retinoic acid receptors (RARs) and/or retinoid X receptors (RXRs). We showed that RAR agonists promoted adipogenesis by upregulating the expression of CCAAT/enhancer-binding protein β (C/EBPβ) in the early stages, but blocked adipogenesis at a later stage in human bone marrow mesenchymal stem cells (hBMSCs). RXR agonists promoted adipogenesis at all time points in hBMSCs. The effect of RAR agonists was mediated mainly by the RARβ subtype. RAR agonists, in contrast to RXR agonists, significantly promoted the expression of RARβ. Knockdown of the RARβ gene via small hairpin RNA (shRNA) attenuated the inhibition of RAR agonists toward adipogenesis. Furthermore, we found that RAR agonists upregulated the transforming growth factor β (TGFβ)/SMAD pathway and Wnt/β-catenin pathway on adipogenesis in hBMSCs, and the stimulating effects were noticeably decreased with the RARβ gene knockdown. Both RAR agonists and RXR agonists inhibited adipogenesis and blocked the promoter activity of C/EBPβ and peroxisome proliferator-activated receptor γ (PPARγ) in SW872 cell. These results indicated the RAR agonists perform dual roles in adipogenesis in hBMSCs, and the TGFβ/SMAD pathway and Wnt/β-catenin pathway may involve the inhibitory effect of RAR agonists. RARβ is the main receptor subtype mediating the effect. The roles of RXR agonists in adipogenesis exhibited cell type-specific differences, and may be based on the integration of signals from different RXR dimers.

  20. Lawsone derivatives target the Wnt/β-catenin signaling pathway in multidrug-resistant acute lymphoblastic leukemia cells.

    Science.gov (United States)

    Hamdoun, Sami; Fleischer, Edmond; Klinger, Anette; Efferth, Thomas

    2017-12-15

    Multidrug resistance (MDR) represents a serious problem in cancer treatment. One strategy to overcome this obstacle is to identify agents that are selectively lethal to MDR cells. The aim of this study was to discover novel compounds against MDR leukemia and to determine the molecular mechanisms behind collateral sensitivity. A library of 1162 compounds was tested against parental, drug-sensitive CCRF-CEM cells using the resazurin assay. A total of 302 compounds showed reasonable activity (less than 50% cell viability). Eleven out of 30 lawsone derivatives revealed considerable collateral sensitivity in MDR P-glycoprotein (Pgp)-overexpressing CEM/ADR5000 cells. They reduced β-catenin activity in a Wnt/β-catenin reporter cell line. Their activities significantly correlated with apolar desolvation (R = 0.819). Compound (1) (3-hydroxy-1,4-dioxo-N-phenyl-naphthalene-2-carboxamide) was the most active compound and dose-dependently down-regulated protein expression of β-catenin, c-MYC, Pgp and Frizzled 7. By molecular docking, we predicted that compound (1) bound to the palmitoyl-binding groove of the cysteine-rich domain of Frizzled-7 and Frizzled-8. Compound (1) neither stimulated ATPase activity of Pgp nor reactive oxygen species generation, both of which have been previously described as possible mechanisms of collateral sensitivity. Instead, we found that Wnt/β-catenin signaling was selectively inhibited in CEM/ADR5000 cells, but not in CCRF-CEM cells. In conclusion, we found for the first time that the inhibition of Wnt/β-catenin signaling may represent a novel molecular mechanism of collateral sensitivity in MDR cells. Wnt/β-catenin signaling, therefore, represents a potential therapeutic target for the selective killing of Pgp-mediated MDR. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Murrayafoline A attenuates the Wnt/{beta}-catenin pathway by promoting the degradation of intracellular {beta}-catenin proteins

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    Choi, Hyuk; Gwak, Jungsug; Cho, Munju; Ryu, Min-Jung [PharmacoGenomics Research Center, Inje University, Busan 614-735 (Korea, Republic of); Lee, Jee-Hyun; Kim, Sang Kyum; Kim, Young Ho [College of Pharmacy, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Lee, Gye Won [Department of Pharmaceutical Engineering, Konyang University, Nonsan 320-711 (Korea, Republic of); Yun, Mi-Young [Department of Beauty Health Care, Daejeon University, Daejeon 305-764 (Korea, Republic of); Cuong, Nguyen Manh [Institute of Natural Products Chemistry, Vietnam Academy of Science and Technology, Hanoi (Viet Nam); Shin, Jae-Gook [PharmacoGenomics Research Center, Inje University, Busan 614-735 (Korea, Republic of); Song, Gyu-Yong, E-mail: gysong@cnu.ac.kr [College of Pharmacy, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Oh, Sangtaek, E-mail: ohsa@inje.ac.kr [PharmacoGenomics Research Center, Inje University, Busan 614-735 (Korea, Republic of)

    2010-01-01

    Molecular lesions in Wnt/{beta}-catenin signaling and subsequent up-regulation of {beta}-catenin response transcription (CRT) occur frequently during the development of colon cancer. To identify small molecules that suppress CRT, we screened natural compounds in a cell-based assay for detection of TOPFalsh reporter activity. Murrayafoline A, a carbazole alkaloid isolated from Glycosmis stenocarpa, antagonized CRT that was stimulated by Wnt3a-conditioned medium (Wnt3a-CM) or LiCl, an inhibitor of glycogen synthase kinase-3{beta} (GSK-3{beta}), and promoted the degradation of intracellular {beta}-catenin without altering its N-terminal phosphorylation at the Ser33/37 residues, marking it for proteasomal degradation, or the expression of Siah-1, an E3 ubiquitin ligase. Murrayafoline A repressed the expression of cyclin D1 and c-myc, which is known {beta}-catenin/T cell factor (TCF)-dependent genes and thus inhibited the proliferation of various colon cancer cells. These findings indicate that murrayafoline A may be a potential chemotherapeutic agent for use in the treatment of colon cancer.

  2. Chronic hypoxia induces the activation of the Wnt/β-catenin signaling pathway and stimulates hippocampal neurogenesis in wild-type and APPswe-PS1ΔE9 transgenic mice in vivo

    Science.gov (United States)

    Varela-Nallar, Lorena; Rojas-Abalos, Macarena; Abbott, Ana C.; Moya, Esteban A.; Iturriaga, Rodrigo; Inestrosa, Nibaldo C.

    2014-01-01

    Hypoxia modulates proliferation and differentiation of cultured embryonic and adult stem cells, an effect that includes β-catenin, a key component of the canonical Wnt signaling pathway. Here we studied the effect of mild hypoxia on the activity of the Wnt/β-catenin signaling pathway in the hippocampus of adult mice in vivo. The hypoxia-inducible transcription factor-1α (HIF-1α) was analyzed as a molecular control of the physiological hypoxic response. Exposure to chronic hypoxia (10% oxygen for 6–72 h) stimulated the activation of the Wnt/β-catenin signaling pathway. Because the Wnt/β-catenin pathway is a positive modulator of adult neurogenesis, we evaluated whether chronic hypoxia was able to stimulate neurogenesis in the subgranular zone (SGZ) of the hippocampal dentate gyrus. Results indicate that hypoxia increased cell proliferation and neurogenesis in adult wild-type mice as determined by Ki67 staining, Bromodeoxyuridine (BrdU) incorporation and double labeling with doublecortin (DCX). Chronic hypoxia also induced neurogenesis in a double transgenic APPswe-PS1ΔE9 mouse model of Alzheimer’s disease (AD), which shows decreased levels of neurogenesis in the SGZ. Our results show for the first time that exposure to hypoxia in vivo can induce the activation of the Wnt/β-catenin signaling cascade in the hippocampus, suggesting that mild hypoxia may have a therapeutic value in neurodegenerative disorders associated with altered Wnt signaling in the brain and also in pathological conditions in which hippocampal neurogenesis is impaired. PMID:24574965

  3. Chronic hypoxia induces the in vivo activation of the Wnt/β-catenin signaling pathway and stimulates hippocampal neurogenesis in wild-type and APPswe-PS1deltaE9 transgenic mice

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    Lorena eVarela-Nallar

    2014-02-01

    Full Text Available Hypoxia modulates proliferation and differentiation of cultured embryonic and adult stem cells, an effect that includes β-catenin a key component of the canonical Wnt signaling pathway. Here we studied in vivo the effect of mild hypoxia on the activity of the Wnt/β-catenin signaling pathway in the hippocampus of adult mice. As a molecular control of the physiological hypoxic response the hypoxia-inducible transcription factor-1α (HIF-1α was analyzed. Exposure to chronic hypoxia (10% oxygen for 6-72 h stimulated the activation of the Wnt/β-catenin signaling pathway. Because the Wnt/β-catenin pathway is a positive modulator of adult neurogenesis, we evaluated whether chronic hypoxia was able to stimulate neurogenesis in the subgranular zone (SGZ of the hippocampal dentate gyrus. Results indicate that hypoxia increased cell proliferation and neurogenesis in adult wild-type mice as determined by Ki67 staining, BrdU incorporation and double labeling with doublecortin. Chronic hypoxia also induced neurogenesis in double transgenic APPswe-PS1deltaE9 mouse model of Alzheimer’s disease (AD, which shows decreased levels of neurogenesis at the SGZ. Our results show for the first time that in vivo exposure to hypoxia can induce the activation of the Wnt/β-catenin signaling cascade in the hippocampus, suggesting that mild hypoxia may have a therapeutic value in neurodegenerative disorder associated with altered Wnt signaling in the brain and also in pathological conditions in which hippocampal neurogenesis is impaired.

  4. Canonical Wnt signaling is antagonized by noncanonical Wnt5a in hepatocellular carcinoma cells

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    Yilmaz Mustafa

    2009-10-01

    Full Text Available Abstract Background β-catenin mutations that constitutively activate the canonical Wnt signaling have been observed in a subset of hepatocellular carcinomas (HCCs. These mutations are associated with chromosomal stability, low histological grade, low tumor invasion and better patient survival. We hypothesized that canonical Wnt signaling is selectively activated in well-differentiated, but repressed in poorly differentiated HCCs. To this aim, we characterized differentiation status of HCC cell lines and compared their expression status of Wnt pathway genes, and explored their activity of canonical Wnt signaling. Results We classified human HCC cell lines into "well-differentiated" and "poorly differentiated" subtypes, based on the expression of hepatocyte lineage, epithelial and mesenchymal markers. Poorly differentiated cell lines lost epithelial and hepatocyte lineage markers, and overexpressed mesenchymal markers. Also, they were highly motile and invasive. We compared the expression of 45 Wnt pathway genes between two subtypes. TCF1 and TCF4 factors, and LRP5 and LRP6 co-receptors were ubiquitously expressed. Likewise, six Frizzled receptors, and canonical Wnt3 ligand were expressed in both subtypes. In contrast, canonical ligand Wnt8b and noncanonical ligands Wnt4, Wnt5a, Wnt5b and Wnt7b were expressed selectively in well- and poorly differentiated cell lines, respectively. Canonical Wnt signaling activity, as tested by a TCF reporter assay was detected in 80% of well-differentiated, contrary to 14% of poorly differentiated cell lines. TCF activity generated by ectopic mutant β-catenin was weak in poorly differentiated SNU449 cell line, suggesting a repressive mechanism. We tested Wnt5a as a candidate antagonist. It strongly inhibited canonical Wnt signaling that is activated by mutant β-catenin in HCC cell lines. Conclusion Differential expression of Wnt ligands in HCC cells is associated with selective activation of canonical Wnt

  5. Various Wavelengths of Light-Emitting Diode Light Regulate the Proliferation of Human Dermal Papilla Cells and Hair Follicles via Wnt/β-Catenin and the Extracellular Signal-Regulated Kinase Pathways.

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    Joo, Hong Jin; Jeong, Kwan Ho; Kim, Jung Eun; Kang, Hoon

    2017-12-01

    The human dermal papilla cells (hDPCs) play an important role in regulation of hair cycling and growth. The aim of this study was to investigate the effect of different wavelengths of light-emitting diode (LED) irradiation on the proliferation of cultured hDPCs and on the growth of human hair follicles (HFs) in vitro. We examined the effect of LED irradiation on Wnt/β-catenin signaling and mitogen-activated protein kinase (MAPK) pathways in hDPCs. Anagen HFs were cultured with LED irradiation and elongation of each hair shaft was measured. The most potent wavelength in promoting the hDPC proliferation is 660 nm and 830 nm promoted hDPC proliferation to a lesser extent than 660 nm. Various wavelengths significantly increased β-catenin, Axin2, Wnt3a, Wnt5a and Wnt10b mRNA expression. LED irradiation significantly increased β-catenin and cyclin D expression, and the phosphorylation of MAPK and extracellular signal-regulated kinase (ERK). HFs irradiated with 415 nm and 660 nm grew longer than control. Our result suggests that LED has a potential to stimulate hDPC proliferation via the activation of Wnt/β-catenin signaling and ERK pathway. To our best knowledge, this is the first report which investigated that the effect of various wavelengths of LED on hDPC proliferation and the underlying mechanisms.

  6. Finding pathways to national-scale land-sector sustainability.

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    Gao, Lei; Bryan, Brett A

    2017-04-12

    The 17 Sustainable Development Goals (SDGs) and 169 targets under Agenda 2030 of the United Nations map a coherent global sustainability ambition at a level of detail general enough to garner consensus amongst nations. However, achieving the global agenda will depend heavily on successful national-scale implementation, which requires the development of effective science-driven targets tailored to specific national contexts and supported by strong national governance. Here we assess the feasibility of achieving multiple SDG targets at the national scale for the Australian land-sector. We scaled targets to three levels of ambition and two timeframes, then quantitatively explored the option space for target achievement under 648 plausible future environmental, socio-economic, technological and policy pathways using the Land-Use Trade-Offs (LUTO) integrated land systems model. We show that target achievement is very sensitive to global efforts to abate emissions, domestic land-use policy, productivity growth rate, and land-use change adoption behaviour and capacity constraints. Weaker target-setting ambition resulted in higher achievement but poorer sustainability outcomes. Accelerating land-use dynamics after 2030 changed the targets achieved by 2050, warranting a longer-term view and greater flexibility in sustainability implementation. Simultaneous achievement of multiple targets is rare owing to the complexity of sustainability target implementation and the pervasive trade-offs in resource-constrained land systems. Given that hard choices are needed, the land-sector must first address the essential food/fibre production, biodiversity and land degradation components of sustainability via specific policy pathways. It may also contribute to emissions abatement, water and energy targets by capitalizing on co-benefits. However, achieving targets relevant to the land-sector will also require substantial contributions from other sectors such as clean energy, food systems

  7. Finding pathways to national-scale land-sector sustainability

    Science.gov (United States)

    Gao, Lei; Bryan, Brett A.

    2017-04-01

    The 17 Sustainable Development Goals (SDGs) and 169 targets under Agenda 2030 of the United Nations map a coherent global sustainability ambition at a level of detail general enough to garner consensus amongst nations. However, achieving the global agenda will depend heavily on successful national-scale implementation, which requires the development of effective science-driven targets tailored to specific national contexts and supported by strong national governance. Here we assess the feasibility of achieving multiple SDG targets at the national scale for the Australian land-sector. We scaled targets to three levels of ambition and two timeframes, then quantitatively explored the option space for target achievement under 648 plausible future environmental, socio-economic, technological and policy pathways using the Land-Use Trade-Offs (LUTO) integrated land systems model. We show that target achievement is very sensitive to global efforts to abate emissions, domestic land-use policy, productivity growth rate, and land-use change adoption behaviour and capacity constraints. Weaker target-setting ambition resulted in higher achievement but poorer sustainability outcomes. Accelerating land-use dynamics after 2030 changed the targets achieved by 2050, warranting a longer-term view and greater flexibility in sustainability implementation. Simultaneous achievement of multiple targets is rare owing to the complexity of sustainability target implementation and the pervasive trade-offs in resource-constrained land systems. Given that hard choices are needed, the land-sector must first address the essential food/fibre production, biodiversity and land degradation components of sustainability via specific policy pathways. It may also contribute to emissions abatement, water and energy targets by capitalizing on co-benefits. However, achieving targets relevant to the land-sector will also require substantial contributions from other sectors such as clean energy, food systems

  8. IL-1β-induced, matrix metalloproteinase-3-regulated proliferation of embryonic stem cell-derived odontoblastic cells is mediated by the Wnt5 signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Ozeki, Nobuaki; Hase, Naoko; Hiyama, Taiki; Yamaguchi, Hideyuki; Kawai, Rie [Department of Endodontics, School of Dentistry, Aichi Gakuin University, Nagoya, Aichi 464-8651 (Japan); Kondo, Ayami [Department of Medicinal Biochemistry, School of Pharmacy, Aichi Gakuin University, Nagoya 464-8650 (Japan); Nakata, Kazuhiko [Department of Endodontics, School of Dentistry, Aichi Gakuin University, Nagoya, Aichi 464-8651 (Japan); Mogi, Makio, E-mail: makio@dpc.agu.ac.jp [Department of Medicinal Biochemistry, School of Pharmacy, Aichi Gakuin University, Nagoya 464-8650 (Japan)

    2014-10-15

    We previously established a method for differentiating induced pluripotent stem cells and embryonic stem (ES) cells into α2 integrin-positive odontoblast-like cells. We also reported that interleukin (IL)-1β induces matrix metalloproteinase (MMP)-3-regulated cell proliferation and suppresses apoptosis in these cells, suggesting that MMP-3 plays a potentially unique physiological role in the regeneration of odontoblast-like cells. Here, we examined whether up-regulation of MMP-3 activity by IL-1β was mediated by Wnt signaling and led to increased proliferation of odontoblast-like cells. IL-1β increased mRNA and protein levels of Wnt5a, Wnt5b and the Wnt receptor Lrp5. Exogenous Wnt5a and Wnt5b were found to increase MMP-3 mRNA, protein and activity, and interestingly the rate of proliferation in these cells. Treatment with siRNAs against Wnt5a, Wnt5b and Lrp5 suppressed the IL-1β-induced increase in MMP-3 expression and suppressed cell proliferation, an effect rescued by application of exogenous Wnt5. These results demonstrate the sequential involvement of Wnt5, Lrp5 and MMP-3 in effecting IL-1β-induced proliferation of ES cell-derived odontoblast-like cells. - Highlights: • IL-1β induces Wnt5, Lrp5/Fzd9 and MMP-3 in ES cell-derived odontoblast-like cells. • IL-1β-induced Wnt5 expression results in increased cell proliferation. • Exogenous Wnt5 increases MMP-3 activity and cell proliferation. • Exogenous Wnt5 rescues IL-1β-driven proliferation with anti-Wnt5 siRNA suppression. • IL-1β-induced cell proliferation involves Wnt5, Lrp5, and MMP-3 sequentially.

  9. Baicalein suppresses metastasis of breast cancer cells by inhibiting EMT via downregulation of SATB1 and Wnt/β-catenin pathway.

    Science.gov (United States)

    Ma, Xingcong; Yan, Wanjun; Dai, Zhijun; Gao, Xiaoyan; Ma, Yinan; Xu, Quntao; Jiang, Jiantao; Zhang, Shuqun

    2016-01-01

    expression of Wnt1 and β-catenin proteins and transcription level of Wnt/β-catenin-targeted genes. Our results demonstrate that baicalein has the potential to suppress breast cancer metastasis, possibly by inhibition of EMT, which may be attributed to downregulation of both SATB1 and the Wnt/β-catenin pathway. Taken together, baicalein may serve as a promising drug for metastasis treatment of breast cancer.

  10. The Ionic Products from Mineral Trioxide Aggregate-induced Odontogenic Differentiation of Dental Pulp Cells via Activation of the Wnt/β-catenin Signaling Pathway.

    Science.gov (United States)

    Chen, Yi-Wen; Ho, Chia-Che; Huang, Tsui-Hsien; Hsu, Tuan-Ti; Shie, Ming-You

    2016-07-01

    Mineral trioxide aggregate (MTA) has been successfully used in clinical applications in endodontics. However, little is known about the involvement of Wnt/β-catenin signaling in human dental pulp cells (hDPC) differentiation with the interaction of MTA in hard tissue regeneration, especially in odontogenesis. Therefore, the aim of this study was to explore odontogenic/osteogenic gene expression and the protein secretion of hDPCs cultured with consecutive concentrations of MTA extracts and carefully examine the particular molecular mechanism that occurs during this process. MTA extracts were prepared by immersing MTA powders into Dulbecco modified Eagle medium at a concentration of 200 mg/mL. hDPCs were cultured with various concentrations of MTA extracts, and the resulting changes in the cells, such as proliferation and odontogenic differentiation, were measured. The results indicate that hDPC proliferation increases remarkably in a time-dependent manner in most treatment groups, except the highest concentration group (200 mg/mL). The Wnt/β-catenin signaling pathway-related genes and proteins are significantly raised when hDPCs are cultured in a wide concentration range of MTA extracts compared with a control, except for the highest concentration group (100 mg/mL), on days 3 and 7 (P MTA extract-induced odontogenic differentiation of hDPCs. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  11. Adamantyl Retinoid-Related Molecules Induce Apoptosis in Pancreatic Cancer Cells by Inhibiting IGF-1R and Wnt/β-Catenin Pathways

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    Lulu Farhana

    2012-01-01

    Full Text Available Pancreatic carcinoma has a dismal prognosis as it often presents as locally advanced or metastatic. We have found that exposure to adamantyl-substituted retinoid-related (ARR compounds 3-Cl-AHPC and AHP3 resulted in growth inhibition and apoptosis induction in PANC-1, Capan-2, and MiaPaCa-2 pancreatic cancer cell lines. In addition, AHP3 and 3-Cl-AHPC inhibited growth and induced apoptosis in spheres derived from the CD44+/CD24+ (CD133+/EpCAM+ stem-like cell population isolated from the pancreatic cancer cell lines. 3-Cl-AHPC-induced apoptosis was preceded by decreasing expression of IGF-1R, cyclin D1, β-catenin, and activated Notch-1 in the pancreatic cancer cell lines. Decreased IGF-1R expression inhibited PANC-1 proliferation, enhanced 3-Cl-AHPC-mediated apoptosis, and significantly decreased sphere formation. 3-Cl-AHPC inhibited the Wnt/β-catenin pathway as indicated by decreased β-catenin nuclear localization and inhibited Wnt/β-catenin activation of transcription factor TCF/LEF. Knockdown of β-catenin using sh-RNA also induced apoptosis and inhibited growth in pancreatic cancer cells. Thus, 3-Cl-AHPC and AHP3 induce apoptosis in pancreatic cancer cells and cancer stem-like cells and may serve as an important potential therapeutic agent in the treatment of pancreatic cancer.

  12. HES5 is a key mediator of Wnt-3a-induced neuronal differentiation.

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    Mußmann, Carolin; Hübner, Rayk; Trilck, Michaela; Rolfs, Arndt; Frech, Moritz J

    2014-06-15

    Human neural stem/progenitor cell (hNPC)-derived neuronal progeny has been suggested as a promising cell source in a variety of neurodegenerative diseases. Understanding the underlying mechanisms that regulate neuronal differentiation is essential for efficient cell-based therapies. Wnt and Notch signaling has been shown to be crucial in this process. However, their interactions in the process of neuronal differentiation remain elusive. By using human fetal (ReNcell VM) and iPS-derived hNPCs we demonstrate that Wnt-3a immediately induced a transient HES1 upregulation and a sustained HES5 repression that was accompanied by upregulation of the proneural gene MASH1. Conversely, overexpression of HES5 resulted in reduced MASH1 expression. Remarkably, HES5 overexpression efficiently blocked Wnt-3a as well as γ-secretase inhibitor N-[N-(3,5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester (DAPT)-induced neuronal differentiation that was accompanied by a strong MASH1 downregulation thus directly linking HES5 repression/MASH1 induction to the proneurogenic effect of Wnt-3a. Stabilized β-catenin or treatment with the specific glycogen synthase kinase 3 beta (GSK3β) inhibitor SB-216763 failed to or only partially mimicked these effects, suggesting a GSK3β- and β-catenin-independent mechanism. Further, inhibition of Wnt-3a-LDL-receptor-related protein 5/6 (LRP5/6) interactions using Dickkopf-1 (Dkk-1) failed to inhibit the modulatory effect of Wnt-3a on HES1/5 and neuronal differentiation. Taken together, these data identify HES5 as a key mediator of the Wnt-3a proneurogenic effect occurring independently of the classical Wnt/β-catenin signaling cascade thus further deciphering crosstalk mechanisms of Wnt and Notch signaling pathways regulating cell fate of hNPCs.

  13. A systems toxicology approach reveals the Wnt-MAPK crosstalk pathway mediated reproductive failure in Caenorhabditis elegans exposed to graphene oxide (GO) but not to reduced graphene oxide (rGO).

    Science.gov (United States)

    Chatterjee, Nivedita; Kim, Youngho; Yang, Jisu; Roca, Carlos P; Joo, Sang-Woo; Choi, Jinhee

    2017-02-01

    The potential hazards of graphene nanomaterials were investigated by exposing the nematode Caenorhabditis elegans to graphene oxide (GO) and reduced graphene oxide (rGO). The underlying mechanisms of the nano-bio interaction were addressed with an integrated systems toxicology approach using global transcriptomics, network-based pathway analysis, and experimental validation of the in-silico-derived hypotheses. Graphene oxide was found to reduce the worms' reproductive health to a greater degree than rGO, but it did not affect survival (24 h endpoint). Comparative analysis of GO vs. rGO effects found that the wingless-type MMTV integration site family (Wnt) pathway and the mitogen-activated protein kinase (MAPK) pathway were evoked in GO- but not in rGO-exposed worms. We therefore hypothesized that crosstalk between the Wnt and MAPK pathways is responsible for C. elegans' reproductive sensitivity to GO exposure. By targeting the individual components of the Wnt-MAPK crosstalk pathway (with qPCR gene expression and mutant reproduction analysis), we found a signaling cascade of MOM-2 → MOM-5 → MOM-4 → LIT-1 → POP-1 → EGL-5. Specifically, the activation of POP-1 (the TCF protein homolog) and subsequent repression of the Wnt/β-catenin target gene (EGL-5), analyzed with target-gene-specific RNAi in POP-1 mutant [pop-1(q645)] worms, were the central mechanisms of reduced reproductive potential in the worms exposed to GO. Our results highlight the distinct biological and molecular mechanisms of GO and rGO exposure and the role of Wnt-MAPK pathway crosstalk in regulating GO-induced reproductive failure in in vivo systems, and they will contribute to the development of efficient and innocuous graphene applications as well to improvements in mechanism-based risk assessment.

  14. Enhancement of osteogenic differentiation of rat adipose tissue-derived mesenchymal stem cells by zinc sulphate under electromagnetic field via the PKA, ERK1/2 and Wnt/β-catenin signaling pathways.

    Directory of Open Access Journals (Sweden)

    Ezzatollah Fathi

    Full Text Available Zinc ion as an essential trace element and electromagnetic fields (EMFs has been reported to be involved in the regulation of bone metabolism. The aim of this study was to elucidate the effects of zinc sulphate (ZnSO4 on the osteogenic differentiation of adipose tissue-derived mesenchymal stem cells (ADSCs in the presence of EMF as a strategy in osteoporosis therapy. Alkaline phophatase (ALP activity measurement, calcium assay and expression of several osteoblastic marker genes were examined to assess the effect of ZnSO4 on the osteogenic differentiation of ADSCs under EMF. The expression of cAMP and PKA was evaluated by ELISA. The expression of β-catenin, Wnt1, Wnt3a, low-density lipoprotein receptor-related protein 5 (LRP5 and reduced dickkopf1 (DKK1 genes were used to detect the Wnt/β-catenin pathway. It was found that ZnSO4, in the presence of EMF, resulted in an increase in the expression of osteogenic genes, ALP activity and calcium levels. EMF, in the presence of ZnSO4, increased the cAMP level and protein kinase A (PKA activity. Treatment of ADSCs with (MAPK/ERK kinase 1/2 inhibitor, or PKA inhibitor, significantly inhibited the promotion of osteogenic markers, indicating that the induction of osteogenesis was dependent on the ERK and PKA signaling pathways. Real-time PCR analysis showed that ZnSO4, in the presence of EMF, increased the mRNA expressions of β-catenin, Wnt1, Wnt3a, LRP5 and DKK1. In this study, it was shown that 0.432 μg/ml ZnSO4, in the presence of 50 Hz, 20 mT EMF, induced the osteogenic differentiation of ADSCs via PKA, ERK1/2 and Wnt/β-catenin signaling pathways.

  15. Baicalein suppresses metastasis of breast cancer cells by inhibiting EMT via downregulation of SATB1 and Wnt/β-catenin pathway

    Directory of Open Access Journals (Sweden)

    Ma X

    2016-04-01

    proteins in vivo were also analyzed by immunohistochemistry.Results: Our results indicated that baicalein suppressed proliferation, migration, and invasion of MDA-MB-231 cells in a time- and dose-dependent manner. Based on assays carried out in xenograft nude mouse model, we found that baicalein inhibited tumor metastasis in vivo. Furthermore, baicalein significantly decreased the expression of SATB1 in MDA-MB-231 cells. It suppressed the expression of vimentin and SNAIL while enhancing the expression of E-cadherin. Baicalein also downregulated the expression of Wnt1 and β-catenin proteins and transcription level of Wnt/β-catenin-targeted genes.Conclusion: Our results demonstrate that baicalein has the potential to suppress breast cancer metastasis, possibly by inhibition of EMT, which may be attributed to downregulation of both SATB1 and the Wnt/β-catenin pathway. Taken together, baicalein may serve as a promising drug for metastasis treatment of breast cancer.Keywords: breast cancer, baicalein, metastasis, EMT, SATB1, Wnt/β-catenin pathway

  16. MUC1 drives epithelial-mesenchymal transition in renal carcinoma through Wnt/β-catenin pathway and interaction with SNAIL promoter.

    Science.gov (United States)

    Gnemmi, Viviane; Bouillez, Audrey; Gaudelot, Kelly; Hémon, Brigitte; Ringot, Bélinda; Pottier, Nicolas; Glowacki, François; Villers, Arnauld; Vindrieux, David; Cauffiez, Christelle; Van Seuningen, Isabelle; Bernard, David; Leroy, Xavier; Aubert, Sébastien; Perrais, Michaël

    2014-05-01

    MUC1 is overexpressed in human carcinomas. The transcription factor SNAIL can activate epithelial-mesenchymal transition (EMT) in cancer cells. In this study, in renal carcinoma, we demonstrate that (i) MUC1 and SNAIL were overexpressed in human sarcomatoid carcinomas, (ii) SNAIL increased indirectly MUC1 expression, (iii) MUC1 overexpression induced EMT, (iv) MUC1 C-terminal domain (MUC1-C) and β-catenin increased SNAIL transcriptional activity by interaction with its promoter and (v) blocking MUC1-C nuclear localization decreased Wnt/β-catenin signaling pathway activation and SNAIL expression. Altogether, our findings demonstrate that MUC1 is an actor in EMT and appears as a new therapeutic target. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  17. Identification of N-[3-(3,4-Dihydroxyphenyl)-1-oxo-2-propenyl]-2-hydroxybenzamide (CGK-101) as a Small Molecule Inhibitor of the Wnt/β-catenin Pathway

    Energy Technology Data Exchange (ETDEWEB)

    Park, Seoyoung; Oh, Sangtaek [Kookmin Univ., Seoul (Korea, Republic of); Lee, Jeehyun; Lee, Jung Sook; Song, Gyuyong [Chungnam National Univ., Daejeon (Korea, Republic of)

    2013-04-15

    We identified CGK-101 as an antiproliferative agent that acts against HCT116 colon cancer cells. CGK-101 induced the degradation of intracellular β-catenin, thereby suppressing the Wnt/β-catenin pathway. Therefore, CGK-101 can be developed as a preventive or therapeutic agent against various cancers that involve abnormal β-catenin accumulation. Colorectal cancer is the most prevalent type of cancer and the second leading cause of cancer-related mortalities in Western countries. Current therapies for colorectal cancer rely on surgical resection, which is rarely curative in advanced disease, and traditional cytotoxic agents exhibit limited effects. Therefore, it is crucial to develop new therapeutic strategies that are based on defined molecular lesions.

  18. Polyethyleneimine mediated DNA transfection in schistosome parasites and regulation of the WNT signaling pathway by a dominant-negative SmMef2.

    Directory of Open Access Journals (Sweden)

    Shuang Liang

    Full Text Available Schistosomiasis is a serious global problem and the second most devastating parasitic disease following malaria. Parasitic worms of the genus Schistosoma are the causative agents of schistosomiasis and infect more than 240 million people worldwide. The paucity of molecular tools to manipulate schistosome gene expression has made an understanding of genetic pathways in these parasites difficult, increasing the challenge of identifying new potential drugs for treatment. Here, we describe the use of a formulation of polyethyleneimine (PEI as an alternative to electroporation for the efficacious transfection of genetic material into schistosome parasites. We show efficient expression of genes from a heterologous CMV promoter and from the schistosome Sm23 promoter. Using the schistosome myocyte enhancer factor 2 (SmMef2, a transcriptional activator critical for myogenesis and other developmental pathways, we describe the development of a dominant-negative form of the schistosome Mef2. Using this mutant, we provide evidence that SmMef2 may regulate genes in the WNT pathway. We also show that SmMef2 regulates its own expression levels. These data demonstrate the use of PEI to facilitate effective transfection of nucleic acids into schistosomes, aiding in the study of schistosome gene expression and regulation, and development of genetic tools for the characterization of molecular pathways in these parasites.

  19. Pathways to sustainable intensification through crop water management

    Science.gov (United States)

    MacDonald, Graham K.; D'Odorico, Paolo; Seekell, David A.

    2016-09-01

    How much could farm water management interventions increase global crop production? This is the central question posed in a global modelling study by Jägermeyr et al (2016 Environ. Res. Lett. 11 025002). They define the biophysical realm of possibility for future gains in crop production related to agricultural water practices—enhancing water availability to crops and expanding irrigation by reducing non-productive water consumption. The findings of Jägermeyr et al offer crucial insight on the potential for crop water management to sustainably intensify agriculture, but they also provide a benchmark to consider the broader role of sustainable intensification targets in the global food system. Here, we reflect on how the global crop water management simulations of Jägermeyr et al could interact with: (1) farm size at more local scales, (2) downstream water users at the river basin scale, as well as (3) food trade and (4) demand-side food system strategies at the global scale. Incorporating such cross-scale linkages in future research could highlight the diverse pathways needed to harness the potential of farm-level crop water management for a more productive and sustainable global food system.

  20. Activation of Wnt signaling pathway by human papillomavirus E6 and E7 oncogenes in HPV16-positive oropharyngeal squamous carcinoma cells.

    Science.gov (United States)

    Rampias, Theodore; Boutati, Eleni; Pectasides, Eirini; Sasaki, Clarence; Kountourakis, Panteleimon; Weinberger, Paul; Psyrri, Amanda

    2010-03-01

    We sought to determine the role of human papillomavirus (HPV) E6 and E7 oncogenes in nuclear beta-catenin accumulation, a hallmark of activated canonical Wnt signaling pathway. We used HPV16-positive oropharyngeal cancer cell lines 147T and 090, HPV-negative cell line 040T, and cervical cell lines SiHa (bearing integrated HPV16) and HeLa (bearing integrated HPV18) to measure the cytoplasmic and nuclear beta-catenin levels and the beta-catenin/Tcf transcriptional activity before and after E6/E7 gene silencing. Repression of HPV E6 and E7 genes induced a substantial reduction in nuclear beta-catenin levels. Luciferase assay showed that transcriptional activation of Tcf promoter by beta-catenin was lower after silencing. The protein levels of beta-catenin are tightly regulated by the ubiquitin/proteasome system. We therefore performed expression analysis of regulators of beta-catenin degradation and nuclear transport and showed that seven in absentia homologue (Siah-1) mRNA and protein levels were substantially upregulated after E6/E7 repression. Siah-1 protein promotes the degradation of beta-catenin through the ubiquitin/proteasome system. To determine whether Siah-1 is important for the proteasomal degradation of beta-catenin in HPV16-positive oropharyngeal cancer cells, we introduced a Siah-1 expression vector into 147T and 090 cells and found substantial reduction of endogenous beta-catenin in these cells. Thus, E6 and E7 are involved in beta-catenin nuclear accumulation and activation of Wnt signaling in HPV-induced cancers. In addition, we show the significance of the endogenous Siah-1-dependent ubiquitin/proteasome pathway for beta-catenin degradation and its regulation by E6/E7 viral oncoproteins in HPV16-positive oropharyngeal cancer cells.

  1. Gene and protein expressions and metabolomics exhibit activated redox signaling and wnt/β-catenin pathway are associated with metabolite dysfunction in patients with chronic kidney disease

    Directory of Open Access Journals (Sweden)

    Dan-Qian Chen

    2017-08-01

    metabolome, activation of inflammatory/oxidative pathway and Wnt/β-catenin signaling and suppression of antioxidant pathway.

  2. Adult Drosophila sensory neurons specify dendritic territories independently of dendritic contacts through the Wnt5-Drl signaling pathway.

    Science.gov (United States)

    Yasunaga, Kei-ichiro; Tezuka, Akane; Ishikawa, Natsuko; Dairyo, Yusuke; Togashi, Kazuya; Koizumi, Hiroyuki; Emoto, Kazuo

    2015-08-15

    Sensory neurons with common functions are often nonrandomly arranged and form dendritic territories in stereotypic spatial patterns throughout the nervous system, yet molecular mechanisms of how neurons specify dendritic territories remain largely unknown. In Drosophila larvae, dendrites of class IV sensory (C4da) neurons completely but nonredundantly cover the whole epidermis, and the boundaries of these tiled dendritic fields are specified through repulsive interactions between homotypic dendrites. Here we report that, unlike the larval C4da neurons, adult C4da neurons rely on both dendritic repulsive interactions and external positional cues to delimit the boundaries of their dendritic fields. We identify Wnt5 derived from sternites, the ventral-most part of the adult abdominal epidermis, as the critical determinant for the ventral boundaries. Further genetic data indicate that Wnt5 promotes dendrite termination on the periphery of sternites through the Ryk receptor family kinase Derailed (Drl) and the Rho GTPase guanine nucleotide exchange factor Trio in C4da neurons. Our findings thus uncover the dendritic contact-independent mechanism that is required for dendritic boundary specification and suggest that combinatory actions of the dendritic contact-dependent and -independent mechanisms may ensure appropriate dendritic territories of a given neuron. © 2015 Yasunaga et al.; Published by Cold Spring Harbor Laboratory Press.

  3. Resveratrol suppresses IGF-1 induced human colon cancer cell proliferation and elevates apoptosis via suppression of IGF-1R/Wnt and activation of p53 signaling pathways

    Directory of Open Access Journals (Sweden)

    Radhakrishnan Sridhar

    2010-05-01

    Full Text Available Abstract Background Obesity is a global phenomenon and is associated with various types of cancer, including colon cancer. There is a growing interest for safe and effective bioactive compounds that suppress the risk for obesity-promoted colon cancer. Resveratrol (trans-3, 4', 5,-trihydroxystilbene, a stilbenoid found in the skin of red grapes and peanuts suppresses many types of cancers by regulating cell proliferation and apoptosis through a variety of mechanisms, however, resveratrol effects on obesity-promoted colon cancer are not clearly established. Methods We investigated the anti-proliferative effects of resveratrol on HT-29 and SW480 human colon cancer cells in the presence and absence of insulin like growth factor-1 (IGF-1; elevated during obesity and elucidated the mechanisms of action using IGF-1R siRNA in HT-29 cells which represents advanced colon carcinogenesis. Results Resveratrol (100-150 μM exhibited anti-proliferative properties in HT-29 cells even after IGF-1 exposure by arresting G0/G1-S phase cell cycle progression through p27 stimulation and cyclin D1 suppression. Treatment with resveratrol suppressed IGF-1R protein levels and concurrently attenuated the downstream Akt/Wnt signaling pathways that play a critical role in cell proliferation. Targeted suppression of IGF-1R using IGF-1R siRNA also affected these signaling pathways in a similar manner. Resveratrol treatment induced apoptosis by activating tumor suppressor p53 protein, whereas IGF-1R siRNA treatment did not affect apoptosis. Our data suggests that resveratrol not only suppresses cell proliferation by inhibiting IGF-1R and its downstream signaling pathways similar to that of IGF-1R siRNA but also enhances apoptosis via activation of the p53 pathway. Conclusions For the first time, we report that resveratrol suppresses colon cancer cell proliferation and elevates apoptosis even in the presence of IGF-1 via suppression of IGF-1R/Akt/Wnt signaling pathways and

  4. Wnt proteins regulate acetylcholine receptor clustering in muscle cells.

    Science.gov (United States)

    Zhang, Bin; Liang, Chuan; Bates, Ryan; Yin, Yiming; Xiong, Wen-Cheng; Mei, Lin

    2012-02-06

    The neuromuscular junction (NMJ) is a cholinergic synapse that rapidly conveys signals from motoneurons to muscle cells and exhibits a high degree of subcellular specialization characteristic of chemical synapses. NMJ formation requires agrin and its coreceptors LRP4 and MuSK. Increasing evidence indicates that Wnt signaling regulates NMJ formation in Drosophila, C. elegans and zebrafish. In the study we systematically studied the effect of all 19 different Wnts in mammals on acetylcholine receptor (AChR) cluster formation. We identified five Wnts (Wnt9a, Wnt9b, Wnt10b, Wnt11, and Wnt16) that are able to stimulate AChR clustering, of which Wnt9a and Wnt11 are expressed abundantly in developing muscles. Using Wnt9a and Wnt11 as example, we demonstrated that Wnt induction of AChR clusters was dose-dependent and non-additive to that of agrin, suggesting that Wnts may act via similar pathways to induce AChR clusters. We provide evidence that Wnt9a and Wnt11 bind directly to the extracellular domain of MuSK, to induce MuSK dimerization and subsequent tyrosine phosphorylation of the kinase. In addition, Wnt-induced AChR clustering requires LRP4. These results identify Wnts as new players in AChR cluster formation, which act in a manner that requires both MuSK and LRP4, revealing a novel function of LRP4.

  5. Wnt proteins regulate acetylcholine receptor clustering in muscle cells

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    Zhang Bin

    2012-02-01

    Full Text Available Abstract Background The neuromuscular junction (NMJ is a cholinergic synapse that rapidly conveys signals from motoneurons to muscle cells and exhibits a high degree of subcellular specialization characteristic of chemical synapses. NMJ formation requires agrin and its coreceptors LRP4 and MuSK. Increasing evidence indicates that Wnt signaling regulates NMJ formation in Drosophila, C. elegans and zebrafish. Results In the study we systematically studied the effect of all 19 different Wnts in mammals on acetylcholine receptor (AChR cluster formation. We identified five Wnts (Wnt9a, Wnt9b, Wnt10b, Wnt11, and Wnt16 that are able to stimulate AChR clustering, of which Wnt9a and Wnt11 are expressed abundantly in developing muscles. Using Wnt9a and Wnt11 as example, we demonstrated that Wnt induction of AChR clusters was dose-dependent and non-additive to that of agrin, suggesting that Wnts may act via similar pathways to induce AChR clusters. We provide evidence that Wnt9a and Wnt11 bind directly to the extracellular domain of MuSK, to induce MuSK dimerization and subsequent tyrosine phosphorylation of the kinase. In addition, Wnt-induced AChR clustering requires LRP4. Conclusions These results identify Wnts as new players in AChR cluster formation, which act in a manner that requires both MuSK and LRP4, revealing a novel function of LRP4.

  6. Wnt signaling during cochlear development.

    Science.gov (United States)

    Munnamalai, Vidhya; Fekete, Donna M

    2013-05-01

    Wnt signaling is a hallmark of all embryonic development with multiple roles at multiple developmental time points. Wnt signaling is also important in the development of several organs, one of which is the inner ear, where it participates in otic specification, the formation of vestibular structures, and the development of the cochlea. In particular, we focus on Wnt signaling in the auditory organ, the cochlea. Attempting to dissect the multiple Wnt signaling pathways in the mammalian cochlea is a challenging task due to limited expression data, particularly at proliferating stages. To offer predictions about Wnt activity, we compare cochlear development with that of other biological systems such as Xenopus retina, brain, cancer cells and osteoblasts. Wnts are likely to regulate development through crosstalk with other signaling pathways, particularly Notch and FGF, leading to changes in the expression of Sox2 and proneural (pro-hair cell) genes. In this review we have consolidated the known signaling pathways in the cochlea with known developmental roles of Wnts from other systems to generate a potential timeline of cochlear development. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Renal hypodysplasia associates with a WNT4 variant that causes aberrant canonical WNT signaling.

    Science.gov (United States)

    Vivante, Asaf; Mark-Danieli, Michal; Davidovits, Miriam; Harari-Steinberg, Orit; Omer, Dorit; Gnatek, Yehudit; Cleper, Roxana; Landau, Daniel; Kovalski, Yael; Weissman, Irit; Eisenstein, Israel; Soudack, Michalle; Wolf, Haike Reznik; Issler, Naomi; Lotan, Danny; Anikster, Yair; Dekel, Benjamin

    2013-03-01

    Abnormal differentiation of the renal stem/progenitor pool into kidney tissue can lead to renal hypodysplasia (RHD), but the underlying causes of RHD are not well understood. In this multicenter study, we identified 20 Israeli pedigrees with isolated familial, nonsyndromic RHD and screened for mutations in candidate genes involved in kidney development, including PAX2, HNF1B, EYA1, SIX1, SIX2, SALL1, GDNF, WNT4, and WT1. In addition to previously reported RHD-causing genes, we found that two affected brothers were heterozygous for a missense variant in the WNT4 gene. Functional analysis of this variant revealed both antagonistic and agonistic canonical WNT stimuli, dependent on cell type. In HEK293 cells, WNT4 inhibited WNT3A induced canonical activation, and the WNT4 variant significantly enhanced this inhibition of the canonical WNT pathway. In contrast, in primary cultures of human fetal kidney cells, which maintain WNT activation and more closely represent WNT signaling in renal progenitors during nephrogenesis, this mutation caused significant loss of function, resulting in diminished canonical WNT/β-catenin signaling. In conclusion, heterozygous WNT4 variants are likely to play a causative role in renal hypodysplasia.

  8. Targeting the Wnt/β-catenin signaling pathway in liver cancer stem cells and hepatocellular carcinoma cell lines with FH535.

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    Roberto Gedaly

    Full Text Available Activation of the Wnt/β-catenin pathway has been observed in at least 1/3 of hepatocellular carcinomas (HCC, and a significant number of these have mutations in the β-catenin gene. Therefore, effective inhibition of this pathway could provide a novel method to treat HCC. The purposed of this study was to determine whether FH535, which was previously shown to block the β-catenin pathway, could inhibit β-catenin activation of target genes and inhibit proliferation of Liver Cancer Stem Cells (LCSC and HCC cell lines. Using β-catenin responsive reporter genes, our data indicates that FH535 can inhibit target gene activation by endogenous and exogenously expressed β-catenin, including the constitutively active form of β-catenin that contains a Serine37Alanine mutation. Our data also indicate that proliferation of LCSC and HCC lines is inhibited by FH535 in a dose-dependent manner, and that this correlates with a decrease in the percentage of cells in S phase. Finally, we also show that expression of two well-characterized targets of β-catenin, Cyclin D1 and Survivin, is reduced by FH535. Taken together, this data indicates that FH535 has potential therapeutic value in treatment of liver cancer. Importantly, these results suggest that this therapy may be effective at several levels by targeting both HCC and LCSC.

  9. Slit2/Robo1 signaling promotes intestinal tumorigenesis through Src-mediated activation of the Wnt/β-catenin pathway.

    Science.gov (United States)

    Zhang, Qian-Qian; Zhou, Da-Lei; Lei, Yan; Zheng, Li; Chen, Sheng-Xia; Gou, Hong-Ju; Gu, Qu-Liang; He, Xiao-Dong; Lan, Tian; Qi, Cui-Ling; Li, Jiang-Chao; Ding, Yan-Qing; Qiao, Liang; Wang, Li-Jing

    2015-02-20

    Slit2 is often overexpressed in cancers. Slit2 is a secreted protein that binds to Roundabout (Robo) receptors to regulate cell growth and migration. Here, we employed several complementary mouse models of intestinal cancers, including the Slit2 transgenic mice, the ApcMin/+ spontaneous intestinal adenoma mouse model, and the DMH/DSS-induced colorectal carcinoma model to clarify function of Slit2/Robo1 signaling in intestinal tumorigenesis. We showed that Slit2 and Robo1 are overexpressed in intestinal tumors and may contribute to tumor generation. The Slit2/Robo1 signaling can induce precancerous lesions of the intestine and tumor progression. Ectopic expression of Slit2 activated Slit2/Robo1 signaling and promoted tumorigenesis and tumor growth. This was mediated in part through activation of the Src signaling, which then down-regulated E-cadherin, thereby activating Wnt/β-catenin signaling. Thus, Slit2/Robo1 signaling is oncogenic in intestinal tumorigenesis.

  10. Electroacupuncture at the governor vessel and bladder meridian acupoints improves postmenopausal osteoporosis through osteoprotegerin/RANKL/RANK and Wnt/β-catenin signaling pathways.

    Science.gov (United States)

    Zheng, Xuefeng; Wu, Guangwen; Nie, Yan; Lin, Yanping

    2015-08-01

    Previous studies have demonstrated that pretreatment with electroacupuncture (EA) at the zusanli/ST36 and sanyinjiao/SP6 acupoints prevents ovariectomy-induced osteoporosis in rats; however, the therapeutic effects of EA at the governor vessel (GV) and bladder meridian (BL) acupoints remain unclear. In the present study, the effects of EA at the GV4, GV6, BL20 and BL23 acupoints on the bones of ovariectomized (OVX) rats were investigated to identify the pathways that mediate the action of EA on the bones. A postmenopausal osteoporosis model was established by performing an ovariectomy in six-month-old female Sprague Dawley rats. Following the ovariectomy, EA treatment was administered once per day for 90 days, with an interval of 5 days per 10 days. The changes in the serum levels of estradiol (E2) and the bone turnover markers, osteocalcin (OC) and tartrate-resistant acid phosphatase 5b (TRACP 5b), were determined, while the bone mineral density (BMD) of the lumbar vertebra and the histomorphology of the femur were observed. Furthermore, the expression of osteoprotegerin (OPG) and receptor activator of nuclear factor-κB ligand (RANKL), which are involved in the OPG/RANKL pathway, were detected by ELISA. In addition, the protein expression levels of low-density lipoprotein receptor-related protein (LRP) 5, β-catenin and runt-related transcription factor (Runx) 2, which are involved in the Wnt/β-catenin signaling pathway, were detected by western blot analysis. The results revealed that the GV and BL EA treatment groups significantly increased the serum levels of E2 and OC, decreased the serum levels of TRACP 5b and increased the BMD of the lumbar vertebra when compared with the OVX group. With regard to the histomorphology of the bone tissue, an ordered arrangement and a slight thinning of the trabeculae, with no evident hairline fractures, was observed in the femurs following EA treatment in the OVX rats. Furthermore, histomorphological analysis revealed that

  11. Pathways to Urban Sustainability: perspective from Portland and the Pacific Northwest : summary of a workshop

    National Research Council Canada - National Science Library

    Brose, Dominic A

    2014-01-01

    "Pathways to Urban Sustainability: Perspective from Portland and the Pacific Northwest is the summary of a workshop convened by the National Research Council's Science and Technology for Sustainability Program in May 2013 to examine...

  12. WNT signaling in neuronal maturation and synaptogenesis

    Science.gov (United States)

    Rosso, Silvana B.; Inestrosa, Nibaldo C.

    2013-01-01

    The Wnt signaling pathway plays a role in the development of the central nervous system and growing evidence indicates that Wnts also regulates the structure and function of the adult nervous system. Wnt components are key regulators of a variety of developmental processes, including embryonic patterning, cell specification, and cell polarity. In the nervous system, Wnt signaling also regulates the formation and function of neuronal circuits by controlling neuronal differentiation, axon outgrowth and guidance, dendrite development, synaptic function, and neuronal plasticity. Wnt factors can signal through three very well characterized cascades: canonical or β-catenin pathway, planar cell polarity pathway and calcium pathway that control different processes. However, divergent downstream cascades have been identified to control neuronal morphogenesis. In the nervous system, the expression of Wnt proteins is a highly controlled process. In addition, deregulation of Wnt signaling has been associated with neurodegenerative diseases. Here, we will review different aspects of neuronal and dendrite maturation, including spinogenesis and synaptogenesis. Finally, the role of Wnt pathway components on Alzheimer’s disease will be revised. PMID:23847469

  13. WNT signalling in neuronal maturation and synaptogenesis

    Directory of Open Access Journals (Sweden)

    Silvana Beatriz Rosso

    2013-07-01

    Full Text Available The Wnt signaling pathway plays a role in the development of the central nervous system (CNS and growing evidence indicates that Wnts also regulates the structure and function of the adult nervous system. Wnt components are key regulators of a variety of developmental processes, including embryonic patterning, cell specification, and cell polarity. In the nervous system, Wnt signaling also regulates the formation and function of neuronal circuits by controlling neuronal differentiation, axon outgrowth and guidance, dendrite development, synaptic function and neuronal plasticity. Wnt factors can signal through three very well characterized cascades: canonical or β-catenin pathway, planar cell polarity pathway and calcium pathway that control different processes. However, divergent downstream cascades have been identified to control neuronal morphogenesis. In the nervous system, the expression of Wnt proteins is a highly controlled process. In addition, deregulation of Wnt signaling has been associated with neurodegenerative diseases. Here, we will review different aspects of neuronal and dendrite maturation, including spinogenesis and synaptogenesis. Finally, the role of Wnt pathway components on Alzheimer’s disease will be revised.

  14. lncRNA DANCR suppresses odontoblast-like differentiation of human dental pulp cells by inhibiting wnt/β-catenin pathway.

    Science.gov (United States)

    Chen, Lingling; Song, Zhi; Huang, Shuheng; Wang, Runfu; Qin, Wei; Guo, Jia; Lin, Zhengmei

    2016-05-01

    Long noncoding RNAs (lncRNAs) have recently emerged as an important class of regulatory molecules in diverse biological processes, although lncRNA involvement in the odontoblast-like differentiation of human dental pulp cells (hDPCs) is poorly understood. We investigate the expression of lncRNAs in this differentiation and explore their underlying role and the involved mechanism. Integrated comparative lncRNA microarray profiling was used to examine lncRNA expression during this differentiation. The differential expression of lncRNAs was validated by quantitative real-time reverse transcription plus the polymerase chain reaction. Differential lncRNA overexpression was performed with an adenoviral vector and the role and mechanism was then investigated in odontoblast-like differentiation. We identified 139 differentially expressed lncRNAs during this differentiation. Among them, five lncRNAs differentially expressed in microarray analysis were validated. Notably, lncRNA DANCR expression was significantly downregulated during hDPC differentiation to odontoblast-like cells in a time-dependent manner. Moreover, lncRNA DANCR overexpression blocked mineralized nodule formation and the expression of DSPP and DMP-1 in hDPCs after 14 days of odontogenic induction. Importantly, the upregulation of DANCR significantly decreased the expression levels of p-GSK-3β and β-catenin expression indicating that lncRNA DANCR can inhibit the activation of the Wnt/β-catenin signal pathway during the odontoblast-like differentiation of hDPCs. Thus, the modulation of Wnt/β-catenin signaling by lncRNA DANCR represents a potential therapeutic option for reparative dentin formation and regenerative endodontics.

  15. Islet Specific Wnt Activation in Human Type II Diabetes

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    Seung-Hee Lee

    2008-01-01

    Full Text Available The Wnt pathway effector gene TCF7L2 has been linked to type II diabetes, making it important to study the role of Wnt signaling in diabetes pathogenesis. We examined the expression of multiple Wnt pathway components in pancreases from normal individuals and type II diabetic individuals. Multiple members of the Wnt signaling pathway, including TCF7L2, Wnt2b, β-catenin, pGSK3β, TCF3, cyclinD1, and c-myc, were undetectable or expressed at low levels in islets from nondiabetic individuals, but were also upregulated specifically in islets of type II diabetic patients. Culture of pancreatic tissue and islet isolation led to Wnt activation that was reversed by the Wnt antagonist sFRP, demonstrating that Wnt activation in that setting was due to soluble Wnt factors. These data support a model in which the Wnt pathway plays a dynamic role in the pathogenesis of type II diabetes and suggest manipulation of Wnt signaling as a new approach to β-cell-directed diabetes therapy.

  16. Insight into the WNT system and its drug related response

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    S. Tamanini

    2013-12-01

    Full Text Available The WNT signalling pathway is a complex system for transferring information for DNA expression from the cell surface receptors to cytoplasm and then to the nucleus. It is based on several proteins that work together as agonists and antagonists in order to maintain homeostasys and to promote anabolic processes. The WNT system acts on all cellular lines involved in bone resorption and formation. WNT pathway can mainly be triggered by two different signalling cascades. The first is well known and is the so-called WNT-beta catenin system (or the canonical pathway, the second is known as the non canonical WNT pathway. WNT proteins form a superfamily of secreted glycoproteins. The association with surface receptors, called Frizzled, that are members of the G protein-coupled receptors superfamily and co receptors like low-density lipoprotein receptor-related proteins 5 and 6 (LRP5/6 complete the WNT system. LRP5/6 show high affinity for WNT antagonists that modulate the activity of this pathway: DKK1 and sclerostin (SCL, that play a crucial role in modulating the WNT system. The WNT-pathway and in particular its antagonists SCL and DKK1 seems to play a key role in the regulation of bone remodeling during treatment with bone active agents such as bisphosphonates, but not only. Their effects become relevant especially in the course of long-term treatments.

  17. Wnt: what's needed to maintain pluripotency?

    Science.gov (United States)

    Niwa, Hitoshi

    2011-09-02

    A precise role for the canonical Wnt pathway in maintaining pluripotency in mouse embryonic stem cells (mESCs) has been debated. Four recent reports add pieces to the puzzle and together these results may help establish a robust model.

  18. A Wnt/beta-catenin pathway antagonist Chibby binds Cenexin at the distal end of mother centrioles and functions in primary cilia formation.

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    Nathan Steere

    Full Text Available The mother centriole of the centrosome is distinguished from immature daughter centrioles by the presence of accessory structures (distal and subdistal appendages, which play an important role in the organization of the primary cilium in quiescent cells. Primary cilia serve as sensory organelles, thus have been implicated in mediating intracellular signal transduction pathways. Here we report that Chibby (Cby, a highly conserved antagonist of the Wnt/β-catenin pathway, is a centriolar component specifically located at the distal end of the mother centriole and essential for assembly of the primary cilium. Cby appeared as a discrete dot in the middle of a ring-like structure revealed by staining with a distal appendage component of Cep164. Cby interacted with one of the appendage components, Cenexin (Cnx, which thereby abrogated the inhibitory effect of Cby on β-catenin-mediated transcriptional activation in a dose-dependent manner. Cby and Cnx did not precisely align, as Cby was detected at a more distal position than Cnx. Cnx emerged earlier than Cby during the cell cycle and was required for recruitment of Cby to the mother centriole. However, Cby was dispensable for Cnx localization to the centriole. During massive centriogenesis in in vitro cultured mouse tracheal epithelial cells, Cby and Cnx were expressed in a similar pattern, which was coincident with the expression of Foxj1. Our results suggest that Cby plays an important role in organization of both primary and motile cilia in collaboration with Cnx.

  19. MeCP2 Promotes Gastric Cancer Progression Through Regulating FOXF1/Wnt5a/β-Catenin and MYOD1/Caspase-3 Signaling Pathways

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    Lingyu Zhao

    2017-02-01

    Full Text Available Methyl-CpG binding protein 2 (MeCP2 has recently been characterized as an oncogene frequently amplified in several types of cancer. However, its precise role in gastric cancer (GC and the molecular mechanism of MeCP2 regulation are still largely unknown. Here we report that MeCP2 is highly expressed in primary GC tissues and the expression level is correlated with the clinicopathologic features of GC. In our experiments, knockdown of MeCP2 inhibited tumor growth. Molecular mechanism of MeCP2 regulation was investigated using an integrated approach with combination of microarray analysis and chromatin immunoprecipitation sequencing (ChIP-Seq. The results suggest that MeCP2 binds to the methylated CpG islands of FOXF1 and MYOD1 promoters and inhibits their expression at the transcription level. Furthermore, we show that MeCP2 promotes GC cell proliferation via FOXF1-mediated Wnt5a/β-Catenin signaling pathway and suppresses apoptosis through MYOD1-mediated Caspase-3 signaling pathway. Due to its high expression level in GC and its critical function in driving GC progression, MeCP2 represents a promising therapeutic target for GC treatment.

  20. MicroRNA-24 Attenuates Neointimal Hyperplasia in the Diabetic Rat Carotid Artery Injury Model by Inhibiting Wnt4 Signaling Pathway

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    Jian Yang

    2016-05-01

    RNA and protein levels was opposite after a balloon injury. However, over-expression of miR-24 after gene delivery increased the mRNA and protein levels of p21. We conclude that over-expression of miR-24 could attenuate VSMC proliferation and neointimal hyperplasia after vascular injuries in diabetic rats. This result is possibly related to the regulation of the expression of Cyclin D1 and p21 through the Wnt4/Dvl-1/β-catenin signaling pathway.

  1. Regulation of norrin receptor frizzled-4 by Wnt2 in colon-derived cells

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    Pérez Cherlyn A

    2007-03-01

    Full Text Available Abstract Background Norrin is a potent Wnt pathway ligand. Aberrant activation of this signaling pathway can result in colon tumors but the role of norrin-based signaling in the genesis of colon cancer, and its relationship to activation of the pathway by traditional Wnt ligands, is not defined. Results Fresh normal human colon tissue and all the cell lines studied expressed mRNA for Fz4, LRP5 and norrin, except Colo205 which lacked Fz4 expression. Canonical Wnt pathway throughput was increased slightly in NCM460 following treatment with Wnt3a CM but was inhibited by Wnt2 and Wnt1. The colon cancer cell line, RKO, responded to Wnt3a CM, Wnt2 and Wnt1 by increasing canonical Wnt pathway throughput. Wnt5a did not affect Wnt pathway throughput in either cell line. Wnt2, but not Wnt3a, abrogated Fz4 expression in NCM460, but not in RKO or another colon cancer cell line, HCT116. This effect on Fz4 was confirmed at both the RNA and protein levels via RT-PCR and a norrin binding assay. The expression of all others 9 Fz receptors did not change after treatment of NCM460 cells with Wnt2. Conclusion The data suggests that colonic mucosa and colon tumors may possess two autoregulatory positive Wnt feedback loops, one through canonical signals induced by Wnt:Fz interactions and one through signals resulting from norrin:Fz4 interactions. The latter interactions may be modulated via regulation of Fz4 expression by Wnt2. Retention of Fz4 by cancers, in contrast to the loss of Fz4 by normal mucosal cells, could provide a selective advantage to the tumor cells. Fz4 expression may play a critical role in responses to Wnt signaling in the tumor microenvironment.

  2. EXPRESSION OF E-CADHERIN AND WNT PATHWAY PROTEINS BETACATENIN, APC, TCF-4 AND SURVIVIN IN GASTRIC ADENOCARCINOMA: CLINICAL AND PATHOLOGICAL IMPLICATION.

    Science.gov (United States)

    Lins, Rodrigo Rego; Oshima, Celina Tizuko Fujiyama; Oliveira, Levindo Alves de; Silva, Marcelo Souza; Mader, Ana Maria Amaral Antonio; Waisberg, Jaques

    2016-01-01

    Gastric cancer is the fifth most frequent cancer and the third most common cause of cancer-related deaths worldwide.It has been reported that Wnt/ betacatenin pathway is activated in 30-50% of these tumors. However,the deregulation of this pathway has not been fully elucidated. To determine the expression of E-cadherin, betacatenin, APC, TCF-4 and survivin proteins in gastric adenocarcinoma tissues and correlate with clinical and pathological parameters. Seventy-one patients with gastric adenocarcinoma undergoing gastrectomy were enrolled. The expression of E-cadherin, betacatenin, APC, TCF-4 and survivin proteins was detected by immunohistochemistryand related to the clinical and pathological parameters. The expression rates of E-cadherin in the membrane was 3%; betacatenin in the cytoplasm and nucleus were 23,4% and 3,1% respectively; APC in the cytoplasm was 94,6%; TCF-4 in the nucleus was 19,4%; and survivin in the nucleus 93,9%. The expression rate of E-cadherin was correlated with older patients (p=0,007), while betacatenin with tumors citoplasma e 3,1% no núcleo; APC em 94,6% no citoplasma; TCF-4 em19,4% no núcleo; e survivina em 93,9% no núcleo. Houve relação entre expressão da proteína E-caderina com a idade mais avançada (p=0,007); betacatenina com tumores <5 cm de diâmetro (p=0,041);APC com tumores proximais (p=0,047); e TCF-4 com tipo difuso da classificação de Lauren (p=0,017) e com o grau de penetração tumoral (p=0,002). A via Wnt/betacatenina não está envolvida na carcinogênese gástrica. Porém, a frequência elevada de survivina permite sugerir que outras vias sinalizadoras devam estar envolvidas na transformação do tecido gástrico.

  3. miR-124 suppresses proliferation and invasion of nasopharyngeal carcinoma cells through the Wnt/β-catenin signaling pathway by targeting Capn4

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    Hu H

    2017-05-01

    Full Text Available Haili Hu,1,* Guanghui Wang,1,* Congying Li2 1Department of Otorhinolaryngology, Huaihe Hospital of Henan University, 2Department of Otorhinolaryngology, School of Medicine, Kaifeng University, Kaifeng, People’s Republic of China *These authors contributed equally to this work Background: Recent studies have demonstrated that microRNA 124 (miR-124 acts as a tumor suppressor in nasopharyngeal carcinoma (NPC; however, the exact molecular mechanism by which miR-124 exerts tumor suppression has not been well elucidated.Materials and methods: We performed quantitative real-time PCR (qRT-PCR to measure the expression of metastasis associated lung adenocarcinoma transcript 1, miR-124, and calpain small subunit 1 (Capn4 mRNAs in NPC cell lines. We also performed western blot analysis to detect the levels of Capn4. Furthermore, we performed MTT assay and transwell invasion assay to determine the proliferation and invasion ability of two NPC cell lines, namely, HONE1 and CNE2 cells, respectively. The verification of targets of miR-124 was performed using prediction softwares and luciferase reporter analysis.Results: According to our results, the expression of Capn4 was found to be elevated, whereas the expression of miR-124 was lowered in NPC cell lines compared with normal nasopharyngeal cells. When we preformed overexpression of miR-124, it suppressed the proliferation and invasion of NPC cells. Moreover, miR-124 suppressed the expression of Capn4 by targeting Capn4 in HONE1 and CNE2 cells. When we preformed overexpression of Capn4, it reversed the inhibitory effect of miR-124 on the proliferation and invasion of NPC cells. Furthermore, miR-124–Capn4 axis decreased the levels of β-catenin, cyclin D1, and c-Myc, the components of the Wnt/β-catenin signaling pathway.Conclusion: The suppression of proliferation and invasion of NPC cells by miR-124 were achieved by the regulation of Wnt/β-catenin signaling pathway by targeting Capn4. The results of

  4. Effect of genetic variation in microRNA binding site in WNT1-inducible signaling pathway protein 1 gene on oral squamous cell carcinoma susceptibility.

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    Hon-Kit Lau

    Full Text Available Oral squamous cell carcinoma (OSCC, which is the most common head and neck cancer, accounts for 1%-2% of all human malignancies and is characterized by poor prognosis and reduced survival rates. WNT1-inducible signaling pathway protein 1 (WISP1, a cysteine-rich protein belonging to the Cyr61, CTGF, Nov (CCN family of matricellular proteins, has many developmental functions and may be involved in carcinogenesis. This study investigated WISP1 single-nucleotide polymorphisms (SNPs to elucidate OSCC susceptibility and clinicopathologic characteristics.Real-time polymerase chain reaction was used to analyze 6 SNPs of WISP1 in 900 OSCC patients and 1200 cancer-free controls. The results showed that WISP1 rs2929970 polymorphism carriers with at least one G allele were susceptible to OSCC. Moreover, compared with smokers, non-smoker patients with higher frequencies of WISP1 rs2929970 (AG + GG variants had a late stage (stages III and IV and a large tumor size. In addition, OSCC patients who were betel quid chewers and carried WISP1 rs16893344 (CT + TT variants had a low risk of lymph node metastasis.Our results demonstrate that a joint effect of WISP1 rs2929970 with smoking as well as WISP1 rs16893344 with betel nut chewing causally contributes to the occurrence of OSCC. WISP1 polymorphism may serve as a marker or a therapeutic target in OSCC.

  5. Acceleration of bone regeneration by activating Wnt/β-catenin signalling pathway via lithium released from lithium chloride/calcium phosphate cement in osteoporosis

    Science.gov (United States)

    Li, Li; Peng, Xiaozhong; Qin, Yongbao; Wang, Renchong; Tang, Jingli; Cui, Xu; Wang, Ting; Liu, Wenlong; Pan, Haobo; Li, Bing

    2017-03-01

    By virtue of its excellent bioactivity and osteoconductivity, calcium phosphate cement (CPC) has been applied extensively in bone engineering. Doping a trace element into CPC can change physical characteristics and enhance osteogenesis. The trace element lithium has been demonstrated to stimulate the proliferation and differentiation of osteoblasts. We investigated the fracture-healing effect of osteoporotic defects with lithium-doped calcium phosphate cement (Li/CPC) and the underlying mechanism. Li/CPC bodies immersed in simulated body fluid converted gradually to hydroxyapatite. Li/CPC extracts stimulated the proliferation and differentiation of osteoblasts upon release of lithium ions (Li+) at 25.35 ± 0.12 to 50.74 ± 0.13 mg/l through activation of the Wnt/β-catenin pathway in vitro. We also examined the effect of locally administered Li+ on defects in rat tibia between CPC and Li/CPC in vivo. Micro-computed tomography and histological staining showed that Li/CPC had better osteogenesis by increasing bone mass and promoting repair in defects compared with CPC (P osteoporosis.

  6. Evaluation of the interaction between proliferation, oxidant-antioxidant status, Wnt pathway, and apoptosis in zebrafish embryos exposed to silver nanoparticles used in textile industry.

    Science.gov (United States)

    Eryılmaz, Oğuz; Ateş, Perihan Seda; Ünal, İsmail; Üstündağ, Ünsal Veli; Bay, Sadık; Alturfan, Ahmet Ata; Yiğitbaşı, Türkan; Emekli-Alturfan, Ebru; Akalın, Mehmet

    2018-01-01

    Antimicrobial textile products are developing rapidly as an important part of functional textiles. Silver nanoparticles (AgNPs) are nanotechnology products with antimicrobial properties. However, exposure to nanoparticles in daily life is an important issue for public health, still being updated. Aim was to evaluate the effects of AgNPs on the development of zebrafish embryos focusing on Wnt pathway, proliferation, oxidant-antioxidant status, and apoptosis. The expressions of ccnd1 and gsk3β were determined by RT-PCR, whereas β-catenin and proliferative cell antigen (PCNA) expressions were determined immunohistochemically. Lipid peroxidation, superoxide dismutase, and glutathione-S-transferase activities were determined spectrophotometrically. Apoptosis was determined using acridine orange staining. Oxidant status, apoptosis, immunohistochemical PCNA, and β catenin staining increased, whereas ccnd1 and antioxidant enzyme activities decreased in AgNPs-exposed embryos in a dose-dependent manner. Our results indicate the interaction of possible mechanisms that may be responsible for the toxic effects of AgNPs in zebrafish embryos. © 2017 Wiley Periodicals, Inc.

  7. Cerebrovascular defects in Foxc1 mutants correlate with aberrant WNT and VEGF-A pathways downstream of retinoic acid from the meninges

    Science.gov (United States)

    Mishra, Swati; Choe, Youngshik; Pleasure, Samuel J.; Siegenthaler, Julie A.

    2016-01-01

    Growth and maturation of the cerebrovasculature is a vital event in neocortical development however mechanisms that control cerebrovascular development remain poorly understood. Mutations in or deletions that include the FOXC1 gene are associated with congenital cerebrovascular anomalies and increased stroke risk in patients. Foxc1 mutant mice display severe cerebrovascular hemorrhage at late gestational ages. While these data demonstrate Foxc1 is required for cerebrovascular development, its broad expression in the brain vasculature combined with Foxc1 mutant’s complex developmental defects have made it difficult to pinpoint its function(s). Using global and conditional Foxc1 mutants, we find 1) significant cerebrovascular growth defects precede cerebral hemorrhage and 2) expression of Foxc1 in neural crest-derived meninges and brain pericytes, though not endothelial cells, is required for normal cerebrovascular development. We provide evidence that reduced levels of meninges-derived retinoic acid (RA), caused by defects in meninges formation in Foxc1 mutants, is a major contributing factor to the cerebrovascular growth defects in Foxc1 mutants. We provide data that suggests that meninges-derived RA ensures adequate growth of the neocortical vasculature via regulating expression of WNT pathway proteins and neural progenitor derived-VEGF-A. Our findings offer the first evidence for a role of the meninges in brain vascular development and provide new insight into potential causes of cerebrovascular defects in patients with FOXC1 mutations. PMID:27671872

  8. Loss of miR-101 expression promotes Wnt/β-catenin signalling pathway activation and malignancy in colon cancer cells.

    Science.gov (United States)

    Strillacci, Antonio; Valerii, Maria Chiara; Sansone, Pasquale; Caggiano, Cinzia; Sgromo, Annamaria; Vittori, Laura; Fiorentino, Michelangelo; Poggioli, Gilberto; Rizzello, Fernando; Campieri, Massimo; Spisni, Enzo

    2013-02-01

    Colorectal cancer (CRC) is the second leading cause of cancer-related mortality in Western countries. Although the aberrant expression of several microRNAs (oncomiRs) is associated with CRC progression, the molecular mechanisms of this phenomenon are still under investigation. Here we show that miR-101 expression is differentially impaired in CRC specimens, depending on tumour grade. miR-101 re-expression suppresses cell growth in 3D, hypoxic survival and invasive potential in CRC cells showing low levels of miR-101. Additionally, we provide molecular evidence of a bidirectional regulatory mechanism between miR-101 expression and important CRC pro-malignant features, such as inflammation, activation of the Wnt/β-catenin signalling pathway and epithelial-mesenchymal transition (EMT). We then propose that up-regulated miR-101 may function as a tumour suppressor in CRC and that its pharmacological restoration might hamper the aggressive behaviour of CRC in vivo. MiR-101 expression may also represent a cancer biomarker for CRC diagnosis and prognosis. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

  9. Ethosuximide Induces Hippocampal Neurogenesis and Reverses Cognitive Deficits in an Amyloid-β Toxin-induced Alzheimer Rat Model via the Phosphatidylinositol 3-Kinase (PI3K)/Akt/Wnt/β-Catenin Pathway.

    Science.gov (United States)

    Tiwari, Shashi Kant; Seth, Brashket; Agarwal, Swati; Yadav, Anuradha; Karmakar, Madhumita; Gupta, Shailendra Kumar; Choubey, Vinay; Sharma, Abhay; Chaturvedi, Rajnish Kumar

    2015-11-20

    Neurogenesis involves generation of new neurons through finely tuned multistep processes, such as neural stem cell (NSC) proliferation, migration, differentiation, and integration into existing neuronal circuitry in the dentate gyrus of the hippocampus and subventricular zone. Adult hippocampal neurogenesis is involved in cognitive functions and altered in various neurodegenerative disorders, including Alzheimer disease (AD). Ethosuximide (ETH), an anticonvulsant drug is used for the treatment of epileptic seizures. However, the effects of ETH on adult hippocampal neurogenesis and the underlying cellular and molecular mechanism(s) are yet unexplored. Herein, we studied the effects of ETH on rat multipotent NSC proliferation and neuronal differentiation and adult hippocampal neurogenesis in an amyloid β (Aβ) toxin-induced rat model of AD-like phenotypes. ETH potently induced NSC proliferation and neuronal differentiation in the hippocampus-derived NSC in vitro. ETH enhanced NSC proliferation and neuronal differentiation and reduced Aβ toxin-mediated toxicity and neurodegeneration, leading to behavioral recovery in the rat AD model. ETH inhibited Aβ-mediated suppression of neurogenic and Akt/Wnt/β-catenin pathway gene expression in the hippocampus. ETH activated the PI3K·Akt and Wnt·β-catenin transduction pathways that are known to be involved in the regulation of neurogenesis. Inhibition of the PI3K·Akt and Wnt·β-catenin pathways effectively blocked the mitogenic and neurogenic effects of ETH. In silico molecular target prediction docking studies suggest that ETH interacts with Akt, Dkk-1, and GSK-3β. Our findings suggest that ETH stimulates NSC proliferation and differentiation in vitro and adult hippocampal neurogenesis via the PI3K·Akt and Wnt·β-catenin signaling. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  10. WNT-er is coming’: WNT signalling in chronic lung diseases

    Science.gov (United States)

    Baarsma, H A

    2017-01-01

    Chronic lung diseases represent a major public health problem with only limited therapeutic options. An important unmet need is to identify compounds and drugs that target key molecular pathways involved in the pathogenesis of chronic lung diseases. Over the last decade, there has been extensive interest in investigating Wingless/integrase-1 (WNT) signalling pathways; and WNT signal alterations have been linked to pulmonary disease pathogenesis and progression. Here, we comprehensively review the cumulative evidence for WNT pathway alterations in chronic lung pathologies, including idiopathic pulmonary fibrosis, pulmonary arterial hypertension, asthma and COPD. While many studies have focused on the canonical WNT/β-catenin signalling pathway, recent reports highlight that non-canonical WNT signalling may also significantly contribute to chronic lung pathologies; these studies will be particularly featured in this review. We further discuss recent advances uncovering the role of WNT signalling early in life, the potential of pharmaceutically modulating WNT signalling pathways and highlight (pre)clinical studies describing promising new therapies for chronic lung diseases. PMID:28416592

  11. AMPK activators suppress breast cancer cell growth by inhibiting DVL3-facilitated Wnt/β-catenin signaling pathway activity.

    Science.gov (United States)

    Zou, Yu-Feng; Xie, Chun-Wei; Yang, Shi-Xin; Xiong, Jian-Ping

    2017-02-01

    Adenosine monophosphate-activated protein kinase (AMPK) is a principal regulator of metabolism and the conservation of energy in cells, and protects them from exposure to various stressors. AMPK activators may exhibit therapeutic potential as suppressors of cell growth; however, the molecular mechanism underlying this phenomenon in various cancer cells remains to be fully elucidated. The present study investigated the effects of AMPK activators on breast cancer cell growth and specified the underlying molecular mechanism. In the present study, the AMPK activator metformin impaired breast cancer cell growth by reducing dishevelled segment polarity protein 3 (DVL3) and β‑catenin levels. Western blotting and immunohistochemistry demonstrated that DVL3 was recurrently upregulated in breast cancer cells that were not treated with metformin, and was significantly associated with enhanced levels of β‑catenin, c‑Myc and cyclin D1. Overexpression of DVL3 resulted in upregulation of β‑catenin and amplification of breast cancer cell growth, which confirmed that Wnt/β‑catenin activation via DVL3 is associated with breast cancer oncogenesis. To elucidate the underlying mechanism of these effects, the present study verified that metformin resulted in a downregulation of DVL3 and β‑catenin in a dose‑dependent manner, and induced phosphorylation of AMPK. Compound C is an AMPK inhibitor, which when administered alongside metformin, significantly abolished the effects of metformin on the reduction of DVL3 and activation of the phosphorylation of AMPK. Notably, the effects of metformin on the mRNA expression levels of DVL3 remain to be fully elucidated; however, a possible interaction with DVL3 at the post‑transcriptional level was observed. It has previously been suggested that the molecular mechanism underlying AMPK activator‑induced suppression of breast cancer cell growth involves an interaction with, and impairment of, DVL3 proteins. The results of the

  12. UBR2 Enriched in p53 Deficient Mouse Bone Marrow Mesenchymal Stem Cell-Exosome Promoted Gastric Cancer Progression via Wnt/β-Catenin Pathway.

    Science.gov (United States)

    Mao, Jiahui; Liang, Zhaofeng; Zhang, Bin; Yang, Huan; Li, Xia; Fu, Hailong; Zhang, Xu; Yan, Yongmin; Xu, Wenrong; Qian, Hui

    2017-11-01

    The deficiency or mutation of p53 has been linked to several types of cancers. The mesenchymal stem cell (MSC) is an important component in the tumor microenvironment, and exosomes secreted by MSCs can transfer bioactive molecules, including proteins and nucleic acid, to other cells in the tumor microenvironment to influence the progress of a tumor. However, whether the state of p53 in MSCs can impact the bioactive molecule secretion of exosomes to promote cancer progression and the regulatory mechanism remains elusive. Our study aimed to investigate the regulation of ubiquitin protein ligase E3 component n-recognin 2 (UBR2) enriched in exosomes secreted by p53 deficient mouse bone marrow MSC (p53-/- mBMMSC) in gastric cancer progression in vivo and in vitro. We found that the concentration of exosome was significantly higher in p53-/- mBMMSC than that in p53 wild-type mBMMSC (p53+/+ mBMMSC). In particular, UBR2 was highly expressed in p53-/- mBMMSC cells and exosomes. P53-/- mBMMSC exosomes enriched UBR2 could be internalized into p53+/+ mBMMSC and murine foregastric carcinoma (MFC) cells and induce the overexpression of UBR2 in these cells which elevated cell proliferation, migration, and the expression of stemness-related genes. Mechanistically, the downregulation of UBR2 in p53-/- mBMMSC exosomes could reverse these actions. Moreover, a majority of Wnt family members, β-catenin, and its downstream genes (CD44, CyclinD1, CyclinD3, and C-myc) were significantly decreased in MFC knockdown UBR2 and β-catenin depletion, an additional depletion of UBR2 had no significant difference in the expression of Nanog, OCT4, Vimentin, and E-cadherin. Taken together, our findings indicated that p53-/- mBMMSC exosomes could deliver UBR2 to target cells and promote gastric cancer growth and metastasis by regulating Wnt/β-catenin pathway. Stem Cells 2017;35:2267-2279. © 2017 AlphaMed Press.

  13. Resveratrol ameliorates the anxiety- and depression-like behavior of subclinical hypothyroidism rat: possible involvement of the HPT axis, HPA axis, and Wnt/β-catenin pathway

    Directory of Open Access Journals (Sweden)

    Jinfang eGe

    2016-05-01

    Full Text Available Metabolic disease subclinical hypothyroidism (SCH is closely associated with depression-like behavior both in human and animal studies, and our previous studies have identified the antidepressant effect of resveratrol (RES in stressed rat model. The aim of this study was to investigate whether RES would manifest an antidepressant effect in SCH rat model and explore the possible mechanism. A SCH rat model was induced by hemi-thyroid electrocauterization, after which the model rats in the RES and LT4 groups received a daily intragastric injection of RES at the dose of 15 mg/kg or LT4 at the dose of 60 μg/kg for 16 days, respectively. The rats’ plasma concentrations of thyroid hormones were measured. Behavioral performance and hypothalamic-pituitary-adrenal (HPA activity were evaluated. The protein expression levels of the Wnt/β-catenin in the hippocampus were detected by western blot. The results showed that RES treatment down-regulated the elevated plasma thyroid stimulating hormone (TSH concentration and the hypothalamic mRNA expression of thyrotropin releasing hormone (TRH in the SCH rats. RES-treated rats showed increased rearing frequency and distance in the OFT, increased sucrose preference in the SPT, and decreased immobility in the FST compared with SCH rats. The ratio of the adrenal gland weight to body weight, the plasma corticosterone levels and the hypothalamic CRH mRNA expression were reduced in the RES-treated rats. Moreover, RES treatment up-regulated the relative ratio of phosphorylated-GSK3β (p-GSK3β/GSK3β and protein levels of p-GSK3β, cyclinD1 and c-myc, while down-regulating the relative ratio of phosphorylated-β-catenin (p-β-catenin/β-catenin and expression of GSK3β in the hippocampus. These findings suggest that RES exerts anxiolytic- and antidepressant-like effect in SCH rats by down-regulating hyperactivity of the HPA axis and regulating both the HPT axis and the Wnt/β-catenin pathway.

  14. Wnt5a Controls Neurite Development in Olfactory Bulb Interneurons

    Directory of Open Access Journals (Sweden)

    Darya Pino

    2011-05-01

    Full Text Available Neurons born in the postnatal SVZ (subventricular zone must migrate a great distance before becoming mature interneurons of the OB (olfactory bulb. During migration immature OB neurons maintain an immature morphology until they reach their destination. While the morphological development of these cells must be tightly regulated, the cellular pathways responsible are still largely unknown. Our results show that the non-canonical Wnt pathway induced by Wnt5a is important for the morphological development of OB interneurons both in vitro and in vivo. Additionally, we demonstrate that non-canonical Wnt signalling works in opposition to canonical Wnt signalling in neural precursors from the SVZ in vitro. This represents a novel role for Wnt5a in the development of OB interneurons and suggests that canonical and non-canonical Wnt pathways dynamically oppose each other in the regulation of dendrite maturation.

  15. Ginkgo biloba exocarp extracts inhibits angiogenesis and its effects on Wnt/β-catenin-VEGF signaling pathway in Lewis lung cancer.

    Science.gov (United States)

    Han, Dongdong; Cao, Chengjie; Su, Ya; Wang, Jun; Sun, Jian; Chen, Huasheng; Xu, Aihua

    2016-11-04

    means MVD was inhibited and so do β-catenin, VEGF, VEGFR2 and p-AKT/AKT protein expression and VEGF and VEGFR2 mRNA expression levels in LLC transplanted tumor of C57BL/6 mice. GBEE played the effects of anti-tumor and anti-metastatic depending upon the inhibition of tumor angiogenesis, which may be closely relevant to its effect in blockage of Wnt /β-catenin-VEGF signaling pathway in LLC. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  16. MicroRNA-300 promotes apoptosis and inhibits proliferation, migration, invasion and epithelial-mesenchymal transition via the Wnt/β-catenin signaling pathway by targeting CUL4B in pancreatic cancer cells.

    Science.gov (United States)

    Zhang, Jia-Qiang; Chen, Shi; Gu, Jiang-Ning; Zhu, Yi; Zhan, Qian; Cheng, Dong-Feng; Chen, Hao; Deng, Xia-Xing; Shen, Bai-Yong; Peng, Cheng-Hong

    2017-07-07

    The study aims to verify the hypothesis that up-regulation of microRNA-300 (miR-300) targeting CUL4B promotes apoptosis and suppresses proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) of pancreatic cancer cells by regulating the Wnt/β-catenin signaling pathway. Pancreatic cancer tissues and adjacent tissues were collected from 110 pancreatic cancer patients. Expression of miR-300, CUL4B, Wnt, β-catenin, E-cadherin, N-cadherin, Snail, GSK-3β, and CyclinD1 were detected using qRT-PCR and Western blot. CFPAC-1, Capan-1, and PANC-1 were classified into blank, negative control (NC), miR-300 mimics, miR-300 inhibitors, siRNA-CUL4B, and miR-300 inhibitors + siRNA-CUL4B groups. The proliferation, migration, invasion abilities, the cell cycle distribution, and apoptosis rates were measured in CCK-8 and Transwell assays. Pancreatic cancer tissues showed increased CUL4B expression but decreased miR-300 expression. When miR-300 was lowly expressed, CUL4B was upregulated which in-turn activated the Wnt/β-catenin pathway to protect the β-catenin expression and thus induce EMT. When miR-300 was highly expressed, CUL4B was downregulated which in-turn inhibited the Wnt/β-catenin pathway to prevent EMT. Weakened cell migration and invasion abilities and enhanced apoptosis were observed in the CUL4B group. The miR-300 inhibitors group exhibited an evident increase in growth rate accompanied the largest tumor volume. Smaller tumor volume and slower growth rate were observed in the miR-300 mimics and siRNA-CUL4B group. Our study concludes that lowly expressed miR-300 may contribute to highly expressed CUL4B activating the Wnt/β-catenin signaling pathway and further stimulating EMT, thus promoting proliferation and migration but suppressing apoptosis of pancreatic cancer cells. © 2017 Wiley Periodicals, Inc.

  17. Anticipating change : sustainable water policy pathways for an uncertain future

    NARCIS (Netherlands)

    Haasnoot, Marjolijn

    2013-01-01

    Water management should preferably bring solutions that sustain even if conditions change. In anticipating change, a sustainable plan should not only achieve economic, environmental, and social targets, but it should also be robust to uncertainty and able to be adapted over time to (unforeseen)

  18. Selenomethionine promoted hippocampal neurogenesis via the PI3K-Akt-GSK3β-Wnt pathway in a mouse model of Alzheimer's disease.

    Science.gov (United States)

    Zheng, Rui; Zhang, Zhong-Hao; Chen, Chen; Chen, Yao; Jia, Shi-Zheng; Liu, Qiong; Ni, Jia-Zuan; Song, Guo-Li

    2017-03-25

    The maintenance of neural system integrity and function is the ultimate goal for the treatment of neurodegenerative disease such as Alzheimer's disease (AD). Neurogenesis plays an integral role in the maintenance of neural and cognitive functions, and its dysfunction is regarded as a major cause of cognitive impairment in AD. Moreover, the induction of neurogenesis by targeting endogenous neural stem cells (NSCs) is considered as one of the most promising treatment strategies. Our previous studies demonstrated that selenomethionine (Se-Met) was able to reduce β-amyloid peptide (Aβ) deposition, decrease Tau protein hyperphosphorylation and markedly improve cognitive functions in triple transgenic (3xTg) AD mice. In this study, we reported that the therapeutic effect of Se-Met on AD could also be due to neurogenesis modulation. By using the cultured hippocampal NSCs from 3xTg AD mice, we discovered that Se-Met (1-10 μM) with low concentration could promote NSC proliferation, while the one with a high concentration (50,100 μM) inhibiting proliferation. In subsequent studies, we also found that Se-Met activated the signaling pathway of PI3K/Akt, and thereby inhibited the GSK3β activity, which would further activated the β-catenin/Cyclin-D signaling pathway and promote NSC proliferation. Besides, after the induction of Se-Met, the number of neurons differentiated from NSCs significantly increased, and the number of astrocytes decreased. After a 90-day treatment with Se-Met (6 μg/mL), the number of hippocampal neurons in 4-month-old AD mice increased significantly, while the one of astrocyte saw a sharp drop. Thus, Se-Met treatment promoted NSCs differentiation into neurons, and subsequently repaired damaged neural systems in AD mice. Being consistent with our in vitro studies, Se-Met acts through the PI3K-Akt- GSK3β-Wnt signaling pathway in vivo. This study provides an unparalleled evidence that selenium (Se) compounds are, to some extent, effective in

  19. Wnt3 and Wnt3a are required for induction of the mid-diencephalic organizer in the caudal forebrain

    Directory of Open Access Journals (Sweden)

    Mattes Benjamin

    2012-04-01

    Full Text Available Abstract Background A fundamental requirement for development of diverse brain regions is the function of local organizers at morphological boundaries. These organizers are restricted groups of cells that secrete signaling molecules, which in turn regulate the fate of the adjacent neural tissue. The thalamus is located in the caudal diencephalon and is the central relay station between the sense organs and higher brain areas. The mid-diencephalic organizer (MDO orchestrates the development of the thalamus by releasing secreted signaling molecules such as Shh. Results Here we show that canonical Wnt signaling in the caudal forebrain is required for the formation of the Shh-secreting MD organizer in zebrafish. Wnt signaling induces the MDO in a narrow time window of 4 hours - between 10 and 14 hours post fertilization. Loss of Wnt3 and Wnt3a prevents induction of the MDO, a phenotype also observed upon blockage of canonical Wnt signaling per se. Pharmaceutical activation of the canonical Wnt pathways in Wnt3/Wnt3a compound morphant embryos is able to restore the lack of the MDO. After blockage of Wnt signaling or knock-down of Wnt3/Wnt3a we find an increase of apoptotic cells specifically within the organizer primordium. Consistently, blockage of apoptosis restores the thalamus organizer MDO in Wnt deficient embryos. Conclusion We have identified canonical Wnt signaling as a novel pathway, that is required for proper formation of the MDO and consequently for the development of the major relay station of the brain - the thalamus. We propose that Wnt ligands are necessary to maintain the primordial tissue of the organizer during somitogenesis by suppressing Tp53-mediated apoptosis.

  20. Protective Effects of Pretreatment with Quercetin Against Lipopolysaccharide-Induced Apoptosis and the Inhibition of Osteoblast Differentiation via the MAPK and Wnt/β-Catenin Pathways in MC3T3-E1 Cells

    Directory of Open Access Journals (Sweden)

    Chun Guo

    2017-10-01

    Full Text Available Background/Aims: Quercetin, a flavonoid found in onions and other vegetables, has potential inhibitory effects on bone resorption in vivo and in vitro. In our previous study, we found that quercetin treatment reversed lipopolysaccharide (LPS-induced inhibition of osteoblast differentiation through the mitogen-activated protein kinase (MAPK pathway in MC3T3-E1 cells. In this study, we investigated the underlying mechanisms of pretreatment with quercetin on apoptosis and the inhibition of osteoblast differentiation in MC3T3-E1 cells induced by LPS. Methods: MC3T3-E1 osteoblasts were treated with quercetin for 2 h; cells were then incubated with LPS in the presence of quercetin for the indicated times. Cell viability was measured using the Cell Counting Kit-8 (CCK-8 assay, and cell apoptosis was evaluated using Hoechst 33258 staining. The mRNA expression levels of osteoblast-specific genes, Bax and caspase-3 were determined by real-time quantitative polymerase chain reaction (qPCR. Protein levels of osteoblast-specific genes, caspase-3, Bax, cytochrome c, Bcl-2, Bcl-XL, phosphorylated MAPKs and Wnt/β-catenin were measured using Western blot assays. The MAPK and Wnt/β-catenin signalling pathways were blocked prior to pretreatment with quercetin. Results: Pretreatment with quercetin significantly restored LPS-suppressed bone mineralization and the mRNA and protein expression levels of osteoblast-specific genes such as Osterix (OSX, runt-related transcription factor 2 (Runx2, alkaline phosphatase (ALP and osteocalcin (OCN in a dose-dependent manner. Pretreatment with quercetin also inhibited osteoblast apoptosis, significantly restored the down-regulated expression of Bcl-2 and Bcl-XL and decreased the upregulated expression of caspase-3, Bax, and cytochrome c in MC3T3-E1 cells induced by LPS. Furthermore, pretreatment with quercetin not only decreased the abundance of phosphorylated p38 MAPK and increased the abundance of phosphorylated

  1. Magnetic nanofiber scaffold-induced stimulation of odontogenesis and pro-angiogenesis of human dental pulp cells through Wnt/MAPK/NF-κB pathways.

    Science.gov (United States)

    Yun, Hyung-Mun; Kang, Soo-Kyung; Singh, Rajendra K; Lee, Jung-Hwan; Lee, Hae-Hyoung; Park, Kyung-Ran; Yi, Jin-Kyu; Lee, Deok-Won; Kim, Hae-Won; Kim, Eun-Cheol

    2016-11-01

    Magnetic biomaterials have recently gained great attention due to their some intriguing cell and tissue responses. However, little attention has been given to the fields of dental tissue regeneration. In this sense, we aim to investigate the effects of magnetic nanofiber scaffolds on the human dental pulp cell (HDPC) behaviors and to elucidate the underlying signaling mechanisms in the events. Magnetic nanofiber scaffolds incorporating magnetic nanoparticles at varying contents were prepared into nanofibrous matrices to cultivate cells. Cell growth by MTS assay, odontoblastic differentiation by alkaline phosphatase (ALP) activity, mineralization, and the mRNA expression of differentiation-related genes of HDPCs, in vitro angiogenesis by migration and capillary tube formation in endothelial cells on the conditioned medium obtained from HDPSCs in the presence or absence of scaffolds. Western blot analysis and confocal immunofluorescene were used to asses signaling pathways. The growth of HDPCs was significantly enhanced on the magnetic scaffolds with respect to the non-magnetic counterpart. The odontogenic differentiation of cells was significantly up-regulated by the culture with magnetic scaffolds. Furthermore, the magnetic scaffolds promoted the HDPC-induced angiogenesis of endothelial cells. The expression of signaling molecules, Wnt3a, phosphorylated GSK-3β and nuclear β-catenin, was substantially stimulated by the magnetic scaffolds; in parallel, the MAPK and NF-κB were highly activated when cultured on the magnetic nanofiber scaffolds. This study is the first to demonstrate that magnetic nanofiber scaffolds stimulate HDPCs in the events of growth, odontogenic differentiation, and pro-angiogenesis, and the findings imply the novel scaffolds can be potentially useful as dentin-pulp regenerative matrices. Copyright © 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  2. TIMELESS confers cisplatin resistance in nasopharyngeal carcinoma by activating the Wnt/β-catenin signaling pathway and promoting the epithelial mesenchymal transition.

    Science.gov (United States)

    Liu, Sai-Lan; Lin, Huan-Xin; Lin, Chu-Yong; Sun, Xiao-Qing; Ye, Li-Ping; Qiu, Fang; Wen, Wen; Hua, Xin; Wu, Xian-Qiu; Li, Jun; Song, Li-Bing; Guo, Ling

    2017-08-28

    This study investigated the expression, clinicopathological significance and mechanism of action of TIMELESS, a mammalian homolog of a Drosophila circadian rhythm gene, in nasopharyngeal carcinoma. Quantitative real-time PCR, western blotting and immunohistochemistry revealed TIMELESS was upregulated in NPC cell lines (n = 8 vs. NP69 cells), and freshly-frozen (n = 6) and paraffin-embedded human NPC specimens (n = 108 vs. normal samples/non-tumor cells). TIMELESS expression was associated with T category (P = 0.002), N category (P = 0.001), clinical stage (P < 0.001), metastasis (P = 0.047), vital status (P = 0.013) and serum Epstein-Barr DNA (P = 0.005). High TIMELESS expression was associated with poorer overall survival (80.7% vs. 95.9%; P = 0.004) and progression free survival (68.1% vs. 88.0%; P = 0.005). Univariate and multivariate analysis revealed TIMELESS was an independent prognostic factor for overall survival and progression free survival. Stable ectopic overexpression of TIMELESS in NPC cell lines conferred resistance to cisplatin-induced apoptosis in vitro and in vivo, promoted an epithelial-to-mesenchymal transition phenotype, and activated the Wnt/β-catenin pathway and downstream gene transcription; knockdown of TIMELESS had the opposite effects. TIMELESS may play a role in the development of NPC and could represent a valuable prognostic factor and potential therapeutic target. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Serum levels of WNT1-inducible signaling pathway protein-1 (WISP-1): a noninvasive biomarker of renal fibrosis in subjects with chronic kidney disease.

    Science.gov (United States)

    Zhong, Xiang; Tu, Yue Ju; Li, Yi; Zhang, Ping; Wang, Wei; Chen, Sha Sha; Li, Li; Chung, Arthur Ck; Lan, Hui Yao; Chen, Hai Yong; Li, Gui Sen; Wang, Li

    2017-01-01

    WNT1-inducible signaling pathway protein-1 (WISP-1) is an extracellular matrix-related protein that plays multiple roles in cellular physiology and pathology. Accumulating evidence shows that WISP-1 is involved in the process underlying fibrotic diseases. However, the correlation between WISP-1 and renal fibrosis is unknown. In this study, we hypothesized that WISP-1 levels might be correlated with renal fibrosis and could be used as a noninvasive biomarker to screen for renal fibrosis in patients with chronic kidney disease (CKD). We first measured the WISP-1 expression levels using a transforming growth factor-β (TGF-β)-induced renal fibrosis tubular epithelial cell (TEC) model and a mouse model of obstructive nephropathy. We then evaluated the correlation between serum WISP-1 levels and fibrosis scores in biopsy-proven renal fibrosis of patients with CKD. Based on the findings from both in vivo and in vitro studies, the levels of WISP-1 and fibrotic parameters (collagen I, fibronectin and α-smooth muscle actin) were significantly increased in the fibrotic models. Consistently, patients with focal proliferative IgA nephropathy, focal segmental glomerular sclerosis and diabetic nephropathy displayed markedly elevated serum WISP-1 levels and fibrosis scores of renal biopsies compared with normal subjects and patients with minimal change disease (PWISP-1 levels were positively correlated with fibrosis scores in the renal biopsies of these patients (r=0.475, P=0.0001). Thus, serum WISP-1 levels may be used as a potential noninvasive biomarker of renal fibrosis in patients with CKD.

  4. Secretion and extracellular space travel of Wnt proteins.

    Science.gov (United States)

    Gross, Julia Christina; Boutros, Michael

    2013-08-01

    Wnt signaling pathways control many processes during development, stem cell maintenance and homeostasis, and their aberrant regulation has been linked to diseases in man including diabetes, neurodegeneration and cancer. Wnts are hydrophobic proteins, however, quite paradoxically, they can travel over distances to induce cell-type specific responses. While there has been an initial focus on elucidating the intracellular signaling cascade, discoveries in the past few years have shed light on a highly complex, and regulated secretory process that guides Wnt proteins through the exocytic pathway. Wnt proteins are at least in portion packaged onto extracellular carriers such as exosomes. Similar to dysregulation of components in the Wnt receiving cell, failure to regulate Wnt secretion has been linked to cancer. Here, we review recent discoveries on factors and processes implicated in Wnt secretion. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Avoiding, transforming, transitioning: pathways to sustainable low carbon passenger transport in developing countries

    DEFF Research Database (Denmark)

    Meza, Maria Josefina Figueroa; Fulton, Lewis; Tiwari, Geetam

    2013-01-01

    This review examines conditions affecting road passenger transport in developing countries that can be instrumental to building a pathway for reducing carbon emissions while concurrently meeting sustainable development goals. By contrasting present and future status of these conditions a vision...

  6. Exploring pathways for sustainable water management in river deltas in a changing environment

    NARCIS (Netherlands)

    Haasnoot, Marjolijn; Middelkoop, H.; Offermans, A.; van Beek, Eelco; van Deursen, W.P.A.

    2012-01-01

    Exploring adaptation pathways into an uncertain future can support decisionmaking in achieving sustainable water management in a changing environment. Our objective is to develop and test a method to identify such pathways by including dynamics from natural variability and the interaction between

  7. Roles of Wnt signaling in bone formation and resorption

    Directory of Open Access Journals (Sweden)

    Yasuhiro Kobayashi

    2008-07-01

    Full Text Available Wnt proteins (Wnts are palmitoylated and glycosylated ligands that play a central role in the early development of organs and tissues. The discovery that loss-of-function mutations in low density lipoprotein receptor-related protein 5 (LRP5, a Wnt co-receptor, led to low bone mass in humans revealed the possible role of Wnt signaling in the regulation of bone remodeling. Many findings obtained from detailed analyses of mice having mutations of Wnt signaling molecules have confirmed that Wnt signaling has potential roles in bone remodeling in both physiological and pathological conditions. There are two pathways of Wnt signaling: β-catenin-dependent canonical and -independent non-canonical pathways. Wnts act on osteoblast precursor cells and promote their differentiation into mature osteoblasts through the β-catenin-dependent canonical pathway. In addition, Wnts suppress bone resorption by regulating the receptor activator of NF-κB ligand (RANKL/osteoprotegerin (OPG ratio through the same pathway in mature osteoblasts. In contrast, recent studies have shown that the activation of the β-catenin-independent non-canonical pathway enhances the RANKL-induced osteoclast formation in mouse macrophage cultures. These results indicate that Wnt-mediated signals are involved in several aspects of bone formation and bone resorption. This review will summarize the current knowledge of the roles of Wnt signaling in bone formation and resorption.

  8. Pathways to Action Competence for Sustainability--Six Themes

    Science.gov (United States)

    Almers, Ellen

    2013-01-01

    What promotes action competence for sustainability? This question is phenomenologically explored through researching in depth the life stories of three Swedish young adults who for several years have limited their own ecological footprints, led environmental initiatives of activist character, engaged in ecosystem protection, and participated in…

  9. Expression of WNT genes in cervical cancer-derived cells: Implication of WNT7A in cell proliferation and migration

    Energy Technology Data Exchange (ETDEWEB)

    Ramos-Solano, Moisés, E-mail: mrsolano84@gmail.com [División de Inmunología, Centro de Investigación Biomédica de Occidente (CIBO)-Instituto Mexicano del Seguro Social (IMSS), Guadalajara, Jalisco (Mexico); Programa de Doctorado en Ciencias Biomédica, Centro Universitario de Ciencias de la Salud (CUCS), Universidad de Guadalajara, Guadalajara, Jalisco (Mexico); Meza-Canales, Ivan D., E-mail: imezacanales@ice.mpg.de [Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, 07745 Jena (Germany); Torres-Reyes, Luis A., E-mail: torres_reyes_88@hotmail.com [División de Inmunología, Centro de Investigación Biomédica de Occidente (CIBO)-Instituto Mexicano del Seguro Social (IMSS), Guadalajara, Jalisco (Mexico); Programa de Doctorado en Ciencias Biomédica, Centro Universitario de Ciencias de la Salud (CUCS), Universidad de Guadalajara, Guadalajara, Jalisco (Mexico); Alvarez-Zavala, Monserrat, E-mail: monse_belan@hotmail.com [División de Inmunología, Centro de Investigación Biomédica de Occidente (CIBO)-Instituto Mexicano del Seguro Social (IMSS), Guadalajara, Jalisco (Mexico); Programa de Doctorado en Ciencias Biomédica, Centro Universitario de Ciencias de la Salud (CUCS), Universidad de Guadalajara, Guadalajara, Jalisco (Mexico); and others

    2015-07-01

    According to the multifactorial model of cervical cancer (CC) causation, it is now recognized that other modifications, in addition to Human papillomavirus (HPV) infection, are necessary for the development of this neoplasia. Among these, it has been proposed that a dysregulation of the WNT pathway might favor malignant progression of HPV-immortalized keratinocytes. The aim of this study was to identify components of the WNT pathway differentially expressed in CC vs. non-tumorigenic, but immortalized human keratinocytes. Interestingly, WNT7A expression was found strongly downregulated in cell lines and biopsies derived from CC. Restoration of WNT7A in CC-derived cell lines using a lentiviral gene delivery system or after adding a recombinant human protein decreases cell proliferation. Likewise, WNT7A silencing in non-tumorigenic cells markedly accelerates proliferation. Decreased WNT7A expression was due to hypermethylation at particular CpG sites. To our knowledge, this is the first study reporting reduced WNT7A levels in CC-derived cells and that ectopic WNT7A restoration negatively affects cell proliferation and migration. - Highlights: • WNT7A is expressed in normal keratinocytes or cervical cells without lesion. • WNT7A is significantly reduced in cervical cancer-derived cells. • Restoration of WNT7A expression in HeLa decreases proliferation and cell migration. • Silencing of WNT7A in HaCaT induces an increased proliferation and migration rate. • Decreased WNT7A expression in this model is due to hypermethylation.

  10. Expression profiling of Wnt signaling genes during gonadal differentiation and gametogenesis in rainbow trout.

    Science.gov (United States)

    Nicol, B; Guiguen, Yann

    2011-01-01

    Wnt signaling plays major roles in various processes, including ovarian differentiation and development in mammals. In order to explore its potential implication during gonadal development in a nonmammalian vertebrate species, expression of Wnt signaling genes was investigated in rainbow trout during gonadal differentiation and gametogenesis. Multiple Wnt pathway genes were expressed and exhibited distinct expression patterns. In ovary, tcf7 was highly expressed during early differentiation, whereas no sexually dimorphic expression of rspo1 was detected. During later ovarian development, wnt11 was highly expressed in granulosa cells and oocytes suggesting an implication in folliculogenesis and oogenesis, whereas wnt9b was principally detected in granulosa cells. In testis, Wnt pathway genes were mostly expressed during early spermatogenesis. Overall, these present results suggest that Wnt signaling is implicated in multiple processes of male and female gonadal development and provide basis for future studies on Wnt signaling functions in teleost fish gonads. Copyright © 2011 S. Karger AG, Basel.

  11. Amazonian Dark Earths: pathways to sustainable development in tropical rainforests?

    Directory of Open Access Journals (Sweden)

    Morgan Schmidt

    2013-04-01

    Full Text Available Fertile dark anthrosols associated with pre-Columbian settlement across the Amazon Basin have sparked wide interest for their potential contribution to sustainable use and management of tropical soils and ecosystems. In the Upper Xingu region of the southern Amazon, research on archaeological settlements and among contemporary descendant populations provides critical new data on the formation and use of anthrosols. These findings provide a basis for describing the variability of soil modifications that result from diverse human activities and a general model for the formation of Amazonian anthrosols. They underscore the potential for indigenous systems of knowledge and resource management to inform efforts for conservation and sustainable development of Amazonian ecosystems.

  12. Wnt Signaling Cascades and the Roles of Syndecan Proteoglycans

    DEFF Research Database (Denmark)

    Pataki, Csilla A; Couchman, John R; Brábek, Jan

    2015-01-01

    /planar cell polarity and Wnt/calcium signaling. Syndecans are type I transmembrane proteoglycans with a long evolutionary history, being expressed in all Bilateria and in almost all cell types. Both Wnt pathways have been extensively studied over the past 30 years and shown to have roles during development...

  13. Wnt signaling, stem cells, and cancer of the gastrointestinal tract

    NARCIS (Netherlands)

    Schepers, A.; Clevers, H.

    2012-01-01

    The Wnt signaling pathway was originally uncovered as one of the prototype developmental signaling cascades in invertebrates as well as in vertebrates. The first indication that Wnt signaling also plays a role in the adult animal came from the study of the intestine of Tcf-4 (Tcf7L2) knockout mice.

  14. Wnt signaling inhibits osteogenic differentiation of human mesenchymal stem cells

    NARCIS (Netherlands)

    de Boer, Jan; Siddappa, R.; Gaspar, Claudia; van Apeldoorn, Aart A.; Fodde, Riccardo; van Blitterswijk, Clemens

    2004-01-01

    Human mesenchymal stem cells (hMSCs) from the bone marrow represent a potential source of pluripotent cells for autologous bone tissue engineering. We previously discovered that over activation of the Wnt signal transduction pathway by either lithium or Wnt3A stimulates hMSC proliferation while

  15. Wnt/β-Catenin Signaling, Disease, and Emerging Therapeutic Modalities

    NARCIS (Netherlands)

    Nusse, Roel; Clevers, Hans

    2017-01-01

    The WNT signal transduction cascade is a main regulator of development throughout the animal kingdom. Wnts are also key drivers of most types of tissue stem cells in adult mammals. Unsurprisingly, mutated Wnt pathway components are causative to multiple growth-related pathologies and to cancer.

  16. The Luteinizing Hormone-Testosterone Pathway Regulates Mouse Spermatogonial Stem Cell Self-Renewal by Suppressing WNT5A Expression in Sertoli Cells.

    Science.gov (United States)

    Tanaka, Takashi; Kanatsu-Shinohara, Mito; Lei, Zhenmin; Rao, C V; Shinohara, Takashi

    2016-08-09

    Spermatogenesis originates from self-renewal of spermatogonial stem cells (SSCs). Previous studies have reported conflicting roles of gonadotropic pituitary hormones in SSC self-renewal. Here, we explored the role of hormonal regulation of SSCs using Fshb and Lhcgr knockout (KO) mice. Although follicle-stimulating hormone (FSH) is thought to promote self-renewal by glial cell line-derived neurotrophic factor (GDNF), no abnormalities were found in SSCs and their microenvironment. In contrast, SSCs were enriched in Lhcgr-deficient mice. Moreover, wild-type SSCs transplanted into Lhcgr-deficient mice showed enhanced self-renewal. Microarray analysis revealed that Lhcgr-deficient testes have enhanced WNT5A expression in Sertoli cells, which showed an immature phenotype. Since WNT5A was upregulated by anti-androgen treatment, testosterone produced by luteinizing hormone (LH) is required for Sertoli cell maturation. WNT5A promoted SSC activity both in vitro and in vivo. Therefore, FSH is not responsible for GDNF regulation, while LH negatively regulates SSC self-renewal by suppressing WNT5A via testosterone. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

  17. The Luteinizing Hormone-Testosterone Pathway Regulates Mouse Spermatogonial Stem Cell Self-Renewal by Suppressing WNT5A Expression in Sertoli Cells

    Directory of Open Access Journals (Sweden)

    Takashi Tanaka

    2016-08-01

    Full Text Available Spermatogenesis originates from self-renewal of spermatogonial stem cells (SSCs. Previous studies have reported conflicting roles of gonadotropic pituitary hormones in SSC self-renewal. Here, we explored the role of hormonal regulation of SSCs using Fshb and Lhcgr knockout (KO mice. Although follicle-stimulating hormone (FSH is thought to promote self-renewal by glial cell line-derived neurotrophic factor (GDNF, no abnormalities were found in SSCs and their microenvironment. In contrast, SSCs were enriched in Lhcgr-deficient mice. Moreover, wild-type SSCs transplanted into Lhcgr-deficient mice showed enhanced self-renewal. Microarray analysis revealed that Lhcgr-deficient testes have enhanced WNT5A expression in Sertoli cells, which showed an immature phenotype. Since WNT5A was upregulated by anti-androgen treatment, testosterone produced by luteinizing hormone (LH is required for Sertoli cell maturation. WNT5A promoted SSC activity both in vitro and in vivo. Therefore, FSH is not responsible for GDNF regulation, while LH negatively regulates SSC self-renewal by suppressing WNT5A via testosterone.

  18. Effect of pioglitazone on the calcification of rat vascular smooth muscle cells through the downregulation of the Wnt/β‑catenin signaling pathway.

    Science.gov (United States)

    Gao, Min; Chen, Tianlei; Wu, Lin; Zhao, Xiufen; Mao, Huijuan; Xing, Changying

    2017-11-01

    The aim of the present study was to investigate the effect and possible mechanism of pioglitazone (PIO) on the calcification of rat vascular smooth muscle cells (VSMCs) in vitro. β‑glycerophosphate (β‑GP; 10 mmol/l) was used to induce calcification of VSMCs treated with a range of concentrations (5, 10, 15 and 20 µmol/l) of PIO for 12 days. Calcium deposits were revealed by Alizarin red staining. Extracellular calcium content was detected using a calcium assay kit. Western blotting was used to measure the expression of α‑smooth muscle actin (α‑SMA), runt‑related transcription factor 2 (Runx2), bone morphogenetic protein‑2 (BMP2), β‑catenin, glycogen synthase kinase‑3β (GSK‑3β), phosphorylated (p)‑GSK‑3β and cyclin‑D1. A total of 10 mmol/l β‑GP, 20 µmol/l PIO and 20 µmol/l peroxisome proliferator‑activated receptor γ (PPAR γ) antagonist GW9662, was added to the cell culture media. The changes of the above indexes were observed. The calcium content in the calcification group, treated with high phosphorus, increased significantly compared with the controls (P<0.05) and all different concentrations of PIO reduced extracellular calcium content (P<0.05). Alizarin red staining was positive in calcified VSMCs and PIO (20 µmol/l) intervention group was almost negative. The expressions of Runx2, β‑catenin, p‑GSK‑3β, BMP2 and cyclin‑D1 increased significantly in the calcification group, and treatment with 20 µmol/l PIO downregulated the expression of all the above proteins, while upregulating the expression of α‑SMA. The PPAR γ antagonist GW9662 could partly inhibit the effect of PIO on calcified VSMCs. The results of the present study indicated that PIO can alleviate the calcification of rat aortic VSMCs induced by β‑GP via inhibiting the activity of the Wnt/β‑catenin signaling pathway.

  19. Upregulation of miR-199a/b contributes to cisplatin resistance via Wnt/β-catenin-ABCG2 signaling pathway in ALDHA1(+) colorectal cancer stem cells.

    Science.gov (United States)

    Chen, Binghe; Zhang, Dezhong; Kuai, Jun; Cheng, Mingkun; Fang, Xiangjie; Li, Guangyan

    2017-06-01

    Cisplatin resistance in colorectal cancer largely results from the colorectal cancer stem cells which could be targeted to improve the efficacy of chemotherapy. MicroRNAs are possible modulators of cancer stem cell characteristics and maybe involved in the retention of cancer stem cell chemoresistance. The aim of this study was to investigate the biological function of miR-199a/b on cisplatin resistance in colorectal cancer stem cells and its related mechanisms. Here, ALDHA1(+) cells from primary colorectal cancer tissues behaved similar to cancer stem cells and were chemoresistant to cisplatin. The presence of a variable fraction of ALDHA1 was detected in 9 out of 10 colorectal cancer specimens. Significantly, increased miR-199a/b expression was detected in ALDHA1(+) colorectal cancer stem cells, accompanied by a downregulation of Gsk3β and an overexpression of β-catenin and ABCG2. In patient cohort, enhanced miR-199a/b expression in colorectal cancer tissues was associated with cisplatin response and poor patient survival. In addition, 80% of colorectal cancer samples showed lower level of Gsk3β than their adjacent normal counterparts. Furthermore, Gsk3β was the direct target of miR-199a/b. MiR-199a/b regulated Wnt/β-catenin pathway by targeting Gsk3β in ALDHA1(+) colorectal cancer stem cells. By blocking Wnt/β-catenin pathway, we implied that ABCG2 lies downstream of Wnt/β-catenin pathway. ABCG2 was further demonstrated to contribute cisplatin resistance in ALDHA1(+) colorectal cancer stem cells and can be regulated by miR-199a/b. Thus, our data suggested that upregulation of miR-199a/b in ALDHA1(+) colorectal cancer stem cells contributed to cisplatin resistance via Wnt/β-catenin-ABCG2 signaling, which sheds new light on understanding the mechanism of cisplatin resistance in colorectal cancer stem cells and facilitates the development of potential therapeutics against colorectal cancer.

  20. Wnt co-receptors Lrp5 and Lrp6 differentially mediate Wnt3a signaling in osteoblasts.

    Directory of Open Access Journals (Sweden)

    Aimy Sebastian

    Full Text Available Wnt3a is a major regulator of bone metabolism however, very few of its target genes are known in bone. Wnt3a preferentially signals through transmembrane receptors Frizzled and co-receptors Lrp5/6 to activate the canonical signaling pathway. Previous studies have shown that the canonical Wnt co-receptors Lrp5 and Lrp6 also play an essential role in normal postnatal bone homeostasis, yet, very little is known about specific contributions by these co-receptors in Wnt3a-dependent signaling. We used high-throughput sequencing technology to identify target genes regulated by Wnt3a in osteoblasts and to elucidate the role of Lrp5 and Lrp6 in mediating Wnt3a signaling. Our study identified 782 genes regulated by Wnt3a in primary calvarial osteoblasts. Wnt3a up-regulated the expression of several key regulators of osteoblast proliferation/ early stages of differentiation while inhibiting genes expressed in later stages of osteoblastogenesis. We also found that Lrp6 is the key mediator of Wnt3a signaling in osteoblasts and Lrp5 played a less significant role in mediating Wnt3a signaling.

  1. Molecular cloning, characterization and expression analysis of Wnt4, Wnt5, Wnt6, Wnt7, Wnt10 and Wnt16 from Litopenaeus vannamei.

    Science.gov (United States)

    Zhang, Shuang; Li, Chao-Zheng; Yang, Qi-Hui; Dong, Xiao-Hui; Chi, Shu-Yan; Liu, Hong-Yu; Shi, Li-Li; Tan, Bei-Ping

    2016-07-01

    The Wnt (Wg-type MMTV integration site) signaling represents as the negative regulator of virus-induced innate immune responses. Wnt genes act as ligands to activate the Wnt signaling. To know more about the information of Wnt genes in invertebrates, Litopenaeus vannamei Wnt genes (LvWnts) were identified and characterized. In this study, Six Wnt genes (LvWnt4, LvWnt5, LvWnt6, LvWnt7, LvWnt10 and LvWnt16) were obtained in L. vannamei. The complete cDNAs open reading frames (ORF) of LvWnt4, LvWnt5, LvWnt6, LvWnt7, LvWnt10 and LvWnt16 were 1077 bp, 1107 bp, 1350 bp, 1047 bp, 1509 bp and 1158 bp (GenBank accession no. KU169896, KU169897, KU169898, KU169899, KU169900 and KU169901), encoding 358, 368, 449, 348, 502 and 385 amino acid (aa) residues respectively. All the six members of LvWnts contain a Wnt1 domain, which is considered as an important feature of Wnt gene family. ClustalW analysis with amino acid sequences revealed that the proportion of identity with other species was more than 48% for all the LvWnts except LvWnt10 (36-41%). The phylogenetic relationship analysis illustrated that different subtype of Wnts formed their own separate branches and were placed in branch of invertebrates respectively with strong bootstrap support. The constitutive expressions of LvWnts were confirmed by RT-PCR in all the examined five developmental stages and eleven tissues of L. vannamei with different express patterns. LvWnt4, LvWnt5 and LvWnt10 were expressed highest in nerve while LvWnt6, LvWnt7 and LvWnt16 were expressed highest in intestine, stomach and gill, respectively. In addition, all the LvWnts were regulated by white spot syndrome virus (WSSV) challenges at different levels in hepatopancreas, gill and hemocytes, suggesting that Wnt genes may play a role in the defense against pathogenic virus infection in innate immune of L. vannamei. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. A pathway to a more sustainable water sector: sustainability-based asset management.

    Science.gov (United States)

    Marlow, D R; Beale, D J; Burn, S

    2010-01-01

    The water sectors of many countries are faced with the need to address simultaneously two overarching challenges; the need to undertake effective asset management coupled with the broader need to evolve business processes so as to embrace sustainability principles. Research has thus been undertaken into the role sustainability principles play in asset management. As part of this research, a series of 25 in-depth interviews were undertaken with water sector professionals from around Australia. Drawing on the results of these interviews, this paper outlines the conceptual relationship between asset management and sustainability along with a synthesis of the relevant opinions voiced in the interviews. The interviews indicated that the participating water authorities have made a strong commitment to sustainability, but there is a need to facilitate change processes to embed sustainability principles into business as usual practices. Interviewees also noted that asset management and sustainability are interlinked from a number of perspectives, especially in the way decision making is undertaken with respect to assets and service provision. The interviews also provided insights into the research needed to develop a holistic sustainability-based asset management framework.

  3. TGIF Governs a Feed-Forward Network that Empowers Wnt Signaling to Drive Mammary Tumorigenesis

    OpenAIRE

    Zhang, Ming-Zhu; Ferrigno, Olivier; Wang, Zhe; Ohnishi, Mutsuko; Prunier, Céline; Levy, Laurence; Razzaque, Mohammed; Horne, Williams C.; Romero, Damian; Tzivion, Guri; Colland, Frédéric; Baron, Roland; Atfi, Azeddine

    2015-01-01

    Many types of human cancers having hyperactivated Wnt signaling display no causative alterations in known effectors of this pathway. Here, we report a function of TGIF in Wnt signaling. TGIF associates with and diverts Axin1 and Axin2 from the β-Catenin destruction complex therefore allowing β-Catenin accrual. Intriguingly, activation of Wnt signaling induces the expression of TGIF, which unveils a feed-forward loop that ensures effective integration of Wnt signaling. In triple negative breas...

  4. Pathway to Support the Sustainable National Health Information System

    Science.gov (United States)

    Sahavechaphan, Naiyana; Phengsuwan, Jedsada; U-Ruekolan, Suriya; Aroonrua, Kamron; Ponhan, Jukrapong; Harnsamut, Nattapon; Vannarat, Sornthep

    Heath information across geographically distributed healthcare centers has been recognized as an essential resource that drives an efficient national health-care plan. There is thus a need for the National Health Information System (NHIS) that provides the transparent and secure access to health information from different healthcare centers both on demand and in a time efficient manner. As healthiness is the ultimate goal of people and nation, we believe that the NHIS should be sustainable by taking the healthcare center and information consumer perspectives into account. Several issues in particular must be resolved altogether: (i) the diversity of health information structures among healthcare centers; (ii) the availability of health information sharing from healthcare centers; (iii) the efficient information access to various healthcare centers; and (iv) the privacy and privilege of heath information. To achieve the sustainable NHIS, this paper details our work which is divided into 3 main phases. Essentially, the first phase focuses on the application of metadata standard to enable the interoperability and usability of health information across healthcare centers. The second phase moves forward to make information sharing possible and to provide an efficient information access to a large number of healthcare centers. Finally, in the third phase, the privacy and privilege of health information is promoted with respect to access rights of information consumers.

  5. Quercetin potentiates the effect of γδ T cells via modulating the expressions of Granzyme B, perforin and IFN-γ and also regulates the Wnt/β-catenin signalling pathway in human colon cancer cells

    Directory of Open Access Journals (Sweden)

    Hai-Yan Lu

    2015-06-01

    Full Text Available Cancer accounts as one of the leading causes of morbidity and mortality. Recent studies focus on the efficiency of phytochemicals in cancer therapy. Influence of quercetin, a flavonoid on the effect of γδ T cells and Wnt/β-catenin signalling pathway in human colon cancer cells (HT55 and HCT116 was investigated. Quercetin at 15-120 µM was observed to markedly reduce the viability of HT55 and HCT116 cells. Quercetin exposure significantly increased γδ T cell proliferation and also raised the expressions of granzyme B (Gra B, perforin (PFP, and interferon- γ (IFN-γ in γδ T cells. Reduced β-catenin expression with increased expressions of phosphorylated- β-catenin, axin1 and 2 were observed in HT55 and HCT116 cells on exposure to quercetin. However β-actin expression was found to be not much altered. The results suggest that quercetin was able to efficiently potentiate the effect of γδ T cells and modulate Wnt/β-catenin signalling pathway.

  6. Inhibition of H3K9me2 Reduces Hair Cell Regeneration after Hair Cell Loss in the Zebrafish Lateral Line by Down-Regulating the Wnt and Fgf Signaling Pathways.

    Science.gov (United States)

    Tang, Dongmei; Lin, Qin; He, Yingzi; Chai, Renjie; Li, Huawei

    2016-01-01

    The activation of neuromast (NM) supporting cell (SC) proliferation leads to hair cell (HC) regeneration in the zebrafish lateral line. Epigenetic mechanisms have been reported that regulate HC regeneration in the zebrafish lateral line, but the role of H3K9me2 in HC regeneration after HC loss remains poorly understood. In this study, we focused on the role of H3K9me2 in HC regeneration following neomycin-induced HC loss. To investigate the effects of H3K9me2 in HC regeneration, we took advantage of the G9a/GLP-specific inhibitor BIX01294 that significantly reduces the dimethylation of H3K9. We found that BIX01294 significantly reduced HC regeneration after neomycin-induced HC loss in the zebrafish lateral line. BIX01294 also significantly reduced the proliferation of NM cells and led to fewer SCs in the lateral line. In situ hybridization showed that BIX01294 significantly down-regulated the Wnt and Fgf signaling pathways, which resulted in reduced SC proliferation and HC regeneration in the NMs of the lateral line. Altogether, our results suggest that down-regulation of H3K9me2 significantly decreases HC regeneration after neomycin-induced HC loss through inactivation of the Wnt/β-catenin and Fgf signaling pathways. Thus H3K9me2 plays a critical role in HC regeneration.

  7. Inhibition of H3K9me2 Reduces Hair Cell Regeneration after Hair Cell Loss in the Zebrafish Lateral Line by Down-Regulating the Wnt and Fgf Signaling Pathways

    Directory of Open Access Journals (Sweden)

    Dongmei eTang

    2016-05-01

    Full Text Available The activation of neuromast supporting cell (SC proliferation leads to hair cell (HC regeneration in the zebrafish lateral line. Epigenetic mechanisms have been reported that regulate HC regeneration in the zebrafish lateral line, but the role of H3K9me2 in HC regeneration after HC loss remains poorly understood. In this study, we focused on the role of H3K9me2 in HC regeneration following neomycin-induced HC loss. To investigate the effects of H3K9me2 in HC regeneration, we took advantage of the G9a/GLP-specific inhibitor BIX01294 that significantly reduces the dimethylation of H3K9. We found that BIX01294 significantly reduced HC regeneration after neomycin-induced HC loss in the zebrafish lateral line. BIX01294 also significantly reduced the proliferation of neuromast cells and led to fewer SCs in the lateral line. In situ hybridization showed that BIX01294 significantly down-regulated the Wnt and Fgf signaling pathways, which resulted in reduced SC proliferation and HC regeneration in the neuromasts of the lateral line. Altogether, our results suggest that down-regulation of H3K9me2 significantly decreases HC regeneration after neomycin-induced HC loss through inactivation of the Wnt/β-catenin and Fgf signaling pathways. Thus H3K9me2 plays a critical role in HC regeneration.

  8. Towards a sustainable hydrogen economy: Hydrogen pathways and infrastructure

    Energy Technology Data Exchange (ETDEWEB)

    Mulder, Grietus; Lenaers, Guido [VITO, Boeretang 200, B-2400 Mol (Belgium); Hetland, Jens [SINTEF Energy Research, Kolbjorn Hejesvei 1A, N-7465 Trondheim (Norway)

    2007-07-15

    Results from the European HySociety project (2003-2005) are revealed in which political, societal and technical challenges for developing a European hydrogen economy have been addressed. The focus is placed on the assessments of hydrogen pathways and infrastructure. It will show that no chain can be selected as an obvious winner according to primary energy demand, emission and cost. In order to ensure that the pathway losses are compensated by the more efficient end-use of the H{sub 2} fuel, calculations based on well-to-tank losses and tank-to-wheel efficiencies are used. Furthermore, in order to look into the consequences of introducing hydrogen, a top-down scenario has been worked out. The message is that certainly the hydrogen distribution part for the transport application has to be improved to avoid loosing the emission gain that is obtainable, especially via carbon capture and storage of the CO{sub 2}. In order to quantify the market development a bottom-up approach has been established in particular for the transport sector. (author)

  9. Development of a synthetic pathway for a sustainable plasticizer

    DEFF Research Database (Denmark)

    Søndergaard, Helle

    was optimized with respect to the temperature, addition time and rate of peracetic acid and substrate concentration i.e. amount of solvent. Furthermore, the effect of water concentration was also investigated. After optimization, the result was satisfying as no large excess of peracetic acid needed to be used....... The conversion rate was high at low temperatures, giving a short reaction time, and the amount of by-product low. The reproducibility of this reaction was high and it was tested many times in up to 2 L scale with the same satisfying result. Two methods for hydrogenation of the epoxide to the mono...... monooleate originating from sunflower oil. Sunflower oil is less expensive and more accessible compared to castor oil and the SNS-A has been tested to have the same plasticizing effect and non-toxic effects as SNS. However, a sustainable and cheap way of synthesizing SNS-A has not been developed. The aim...

  10. Wnt Signaling in Stem Cells and Tumor Stem Cells.

    Science.gov (United States)

    Kahn, Michael

    2015-09-01

    The Wnt signaling cascade is critically important in stem cell biology, both in homeostatic maintenance and repair and regeneration of tissues and organs, through their respective somatic stem cells (SSCs). However, aberrant Wnt signaling is associated with a wide array of tumor types and Wnt signaling is important in the so-termed cancer stem cell/tumor-initiating cell (CSC/TIC) population. The ability to safely therapeutically target the Wnt signaling pathway offers enormous promise. However, just like the Sword of Damocles, significant risks and concerns regarding targeting such a critical pathway in normal stem cell maintenance and tissue homeostasis remain ever present. With this in mind, we review our current understanding of the role of Wnt signaling in SSCs and CSC/TICs and the potential to pharmacologically manipulate these endogenous stem cell populations (both normal and tumor). Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  11. Wnt Signaling Is Required for Long-Term Memory Formation

    Directory of Open Access Journals (Sweden)

    Ying Tan

    2013-09-01

    Full Text Available Wnt signaling regulates synaptic plasticity and neurogenesis in the adult nervous system, suggesting a potential role in behavioral processes. Here, we probed the requirement for Wnt signaling during olfactory memory formation in Drosophila using an inducible RNAi approach. Interfering with β-catenin expression in adult mushroom body neurons specifically impaired long-term memory (LTM without altering short-term memory. The impairment was reversible, being rescued by expression of a wild-type β-catenin transgene, and correlated with disruption of a cellular LTM trace. Inhibition of wingless, a Wnt ligand, and arrow, a Wnt coreceptor, also impaired LTM. Wingless expression in wild-type flies was transiently elevated in the brain after LTM conditioning. Thus, inhibiting three key components of the Wnt signaling pathway in adult mushroom bodies impairs LTM, indicating that this pathway mechanistically underlies this specific form of memory.

  12. Cross-talk between insulin and Wnt signaling in preadipocytes

    DEFF Research Database (Denmark)

    Palsgaard, Jane; Emanuelli, Brice; Winnay, Jonathon N

    2012-01-01

    Disturbed Wnt signaling has been implicated in numerous diseases, including type 2 diabetes and the metabolic syndrome. In the present study, we have investigated cross-talk between insulin and Wnt signaling pathways using preadipocytes with and without knockdown of the Wnt co-receptors LRP5...... are insulin/IGF-1 receptor-dependent and are lost in insulin/IGF-1 receptor double knock-out cells. Conversely, in LRP5 knockdown preadipocytes, insulin-induced phosphorylation of IRS1, Akt, GSK3β, and ERK1/2 is highly reduced. This effect is specific to insulin, as compared with IGF-1, stimulation...... and appears to be due to an inducible interaction between LRP5 and the insulin receptor as demonstrated by co-immunoprecipitation. These data demonstrate that Wnt and insulin signaling pathways exhibit cross-talk at multiple levels. Wnt induces phosphorylation of Akt, ERK1/2, and GSK3β, and this is dependent...

  13. Integrated in silico and experimental methods revealed that Arctigenin inhibited angiogenesis and HCT116 cell migration and invasion through regulating the H1F4A and Wnt/β-catenin pathway.

    Science.gov (United States)

    Zhang, Shouyue; Li, Jie; Song, Sicheng; Li, Jing; Tong, Rongsheng; Zang, Zhihe; Jiang, Qinglin; Cai, Lulu

    2015-11-01

    Arctigenin (ARG) has been previously reported to exert diverse biological activities including anti-proliferation, anti-inflammatory, and antiviral, etc. In the current study, the anti-metastasis and anti-angiogenesis activities of ARG were investigated. To further understand how ARG played these bioactivities, proteomic approaches were used to profile the proteome changes in response to ARG treatment using 2DE-MS/MS. Using these approaches, a total of 50 differentially expressed proteins were identified and clustered. Bioinformatics analysis suggested that multiple signalling pathways were involved. Moreover, ARG induced anti-metastatic and anti-angiogenesis activities were mainly accompanied by a deactivation of the Wnt/β-catenin pathway in HCT116 cells.

  14. Discovery of Novel Drugs to Improve Bone Health in Neurofibromatosis Type 1: The Wnt/Beta-Catenin Pathway in Fracture Repair and Pseudarthrosis

    Science.gov (United States)

    2015-08-01

    appropriate ligand, it is phosphorylated by a multi-protein “destruction” complex, resulting in its ubiquitination and proteosomal degradation . In...the presence of an appropriate Wnt ligand, β-catenin is not degraded , translocates to the nucleus, where in concert with members of the T-cell...in the 1970s by cyclization of diphenhydramine. It has an analgesic effect that is mildly stronger than aspirin , but not as strong as codeine, and has

  15. Inhibition of green tea polyphenol EGCG((-)-epigallocatechin-3-gallate) on the proliferation of gastric cancer cells by suppressing canonical wnt/β-catenin signalling pathway.

    Science.gov (United States)

    Yang, Chenggang; Du, Wenfeng; Yang, Daogui

    2016-11-01

    (-)-Epigallocatechin-3-gallate (EGCG), the major polyphenol in green tea, could affect carcinogenesis and development of many cancers. However, the effects and underlying mechanisms of EGCG on gastric cancer remain unclear. We found that EGCG significantly inhibited proliferation and increased apoptosis of SGC-7901 cells in vitro. The decreased expressions of p-β-catenin(Ser552), p-GSK3β(S9) and β-catenin target genes were detected in SGC-7901 cells after treated by EGCG. XAV939 and β-catenin plasmid were further used to demonstrate the inhibition of EGCG on canonical Wnt/β-catenin signalling. Moreover, EGCG significantly inhibited gastric tumour growth in vivo by inhibiting Wnt/β-catenin signalling. Taken together, our findings establish that EGCG suppressed gastric cancer cell proliferation and demonstrate that this inhibitory effect is related to canonical Wnt/β-catenin signalling. This study raises a new insight into gastric cancer prevention and therapy, and provides evidence that green tea could be used as a nutraceutical beverage.

  16. Genomic insights into Wnt signaling in an early diverging metazoan, the ctenophore Mnemiopsis leidyi

    Science.gov (United States)

    2010-01-01

    Background Intercellular signaling pathways are a fundamental component of the integrating cellular behavior required for the evolution of multicellularity. The genomes of three of the four early branching animal phyla (Cnidaria, Placozoa and Porifera) have been surveyed for key components, but not the fourth (Ctenophora). Genomic data from ctenophores could be particularly relevant, as ctenophores have been proposed to be one of the earliest branching metazoan phyla. Results A preliminary assembly of the lobate ctenophore Mnemiopsis leidyi genome generated using next-generation sequencing technologies were searched for components of a developmentally important signaling pathway, the Wnt/β-catenin pathway. Molecular phylogenetic analysis shows four distinct Wnt ligands (MlWnt6, MlWnt9, MlWntA and MlWntX), and most, but not all components of the receptor and intracellular signaling pathway were detected. In situ hybridization of the four Wnt ligands showed that they are expressed in discrete regions associated with the aboral pole, tentacle apparati and apical organ. Conclusions Ctenophores show a minimal (but not obviously simple) complement of Wnt signaling components. Furthermore, it is difficult to compare the Mnemiopsis Wnt expression patterns with those of other metazoans. mRNA expression of Wnt pathway components appears later in development than expected, and zygotic gene expression does not appear to play a role in early axis specification. Notably absent in the Mnemiopsis genome are most major secreted antagonists, which suggests that complex regulation of this secreted signaling pathway probably evolved later in animal evolution. PMID:20920349

  17. Functional Wnt signaling is increased in idiopathic pulmonary fibrosis.

    Directory of Open Access Journals (Sweden)

    Melanie Königshoff

    Full Text Available BACKGROUND: Idiopathic pulmonary fibrosis (IPF is a fatal lung disease, characterized by distorted lung architecture and loss of respiratory function. Alveolar epithelial cell injury and hyperplasia, enhanced extracellular matrix deposition, and (myofibroblast activation are features of IPF. Wnt/beta-catenin signaling has been shown to determine epithelial cell fate during development. As aberrant reactivation of developmental signaling pathways has been suggested to contribute to IPF pathogenesis, we hypothesized that Wnt/beta-catenin signaling is activated in epithelial cells in IPF. Thus, we quantified and localized the expression and activity of the Wnt/beta-catenin pathway in IPF. METHODOLOGY/PRINCIPAL FINDINGS: The expression of Wnt1, 3a, 7b, and 10b, the Wnt receptors Fzd1-4, Lrp5-6, as well as the intracellular signal transducers Gsk-3beta, beta-catenin, Tcf1, 3, 4, and Lef1 was analyzed in IPF and transplant donor lungs by quantitative real-time (qRT-PCR. Wnt1, 7b and 10b, Fzd2 and 3, beta-catenin, and Lef1 expression was significantly increased in IPF. Immunohistochemical analysis localized Wnt1, Wnt3a, beta-catenin, and Gsk-3beta expression largely to alveolar and bronchial epithelium. This was confirmed by qRT-PCR of primary alveolar epithelial type II (ATII cells, demonstrating a significant increase of Wnt signaling in ATII cells derived from IPF patients. In addition, Western blot analysis of phospho-Gsk-3beta, phospho-Lrp6, and beta-catenin, and qRT-PCR of the Wnt target genes cyclin D1, Mmp 7, or Fibronectin 1 demonstrated increased functional Wnt/beta-catenin signaling in IPF compared with controls. Functional in vitro studies further revealed that Wnt ligands induced lung epithelial cell proliferation and (myofibroblast activation and collagen synthesis. CONCLUSIONS/SIGNIFICANCE: Our study demonstrates that the Wnt/beta-catenin pathway is expressed and operative in adult lung epithelium. Increased Wnt/beta-catenin signaling

  18. Supply Chain Sustainability Analysis of Three Biofuel Pathways

    Energy Technology Data Exchange (ETDEWEB)

    Jacob J. Jacobson; Erin Searcy; Kara Cafferty; Jennifer B. Dunn; Michael Johnson; Zhichao Wang; Michael Wang; Mary Biddy; Abhijit Dutta; Daniel Inman; Eric Tan; Sue Jones; Lesley Snowden-Swan

    2013-11-01

    The Department of Energy’s (DOE) Bioenergy Technologies Office (BETO) collaborates with industrial, agricultural, and non-profit partners to develop and deploy biofuels and other biologically-derived products. As part of this effort, BETO and its national laboratory teams conduct in-depth techno-economic assessments (TEA) of technologies to produce biofuels as part state of technology (SOT) analyses. An SOT assesses progress within and across relevant technology areas based on actual experimental results relative to technical targets and cost goals from design cases and includes technical, economic, and environmental criteria as available. Overall assessments of biofuel pathways begin with feedstock production and the logistics of transporting the feedstock from the farm or plantation to the conversion facility or biorefinery. The conversion process itself is modeled in detail as part of the SOT analysis. The teams then develop an estimate of the biofuel minimum selling price (MSP) and assess the cost competitiveness of the biofuel with conventional fuels such as gasoline.

  19. Neural crest specification by noncanonical Wnt signaling and PAR-1

    Science.gov (United States)

    Ossipova, Olga; Sokol, Sergei Y.

    2011-01-01

    Neural crest (NC) cells are multipotent progenitors that form at the neural plate border, undergo epithelial-mesenchymal transition and migrate to diverse locations in vertebrate embryos to give rise to many cell types. Multiple signaling factors, including Wnt proteins, operate during early embryonic development to induce the NC cell fate. Whereas the requirement for the Wnt/β-catenin pathway in NC specification has been well established, a similar role for Wnt proteins that do not stabilize β-catenin has remained unclear. Our gain- and loss-of-function experiments implicate Wnt11-like proteins in NC specification in Xenopus embryos. In support of this conclusion, modulation of β-catenin-independent signaling through Dishevelled and Ror2 causes predictable changes in premigratory NC. Morpholino-mediated depletion experiments suggest that Wnt11R, a Wnt protein that is expressed in neuroectoderm adjacent to the NC territory, is required for NC formation. Wnt11-like signals might specify NC by altering the localization and activity of the serine/threonine polarity kinase PAR-1 (also known as microtubule-associated regulatory kinase or MARK), which itself plays an essential role in NC formation. Consistent with this model, PAR-1 RNA rescues NC markers in embryos in which noncanonical Wnt signaling has been blocked. These experiments identify novel roles for Wnt11R and PAR-1 in NC specification and reveal an unexpected connection between morphogenesis and cell fate. PMID:22110058

  20. BECCS and Sustainable Land-Use in Mitigation Pathways

    Science.gov (United States)

    Kato, E.; Yamagata, Y.

    2013-12-01

    Bioenergy with Carbon Capture and Storage (BECCS) is a key component of mitigation strategies in the future socio-economic scenarios to keep mean global temperature rise below 2°C above pre-industrial, which would require net negative fossil fuel emissions in the end of the 21st century. Large scale use of BECCS implies certain amount of additional production of biofuels, which could potentially cause substantial carbon emissions from the land-use change. Developing sustainable low carbon scenarios requires careful consideration of the land-use implications involving the large scale BECCS. In this study, we use a global terrestrial biogeochemical cycle model to evaluate effects of land-use change in RCP2.6, which is a scenario with net negative fossil fuel emissions aiming to keep the 2°C temperature target used in CMIP5 future climate change analysis. We also run a global crop model to examine BECCS attainability in the land-use scenario with a consideration of future fertilizer and irrigation use options. In the evaluation, we consider the deployment of bioenergy with both first-generation and second-generation biofuels. Our analysis reveals that first-generation bioenergy crop production would not be sufficient to achieve the required BECCS of RCP2.6 scenario even in the high fertilizer and irrigation use cases. It would require more than doubling the area for bioenergy crops production around 2050 assumed in RCP2.6, however, such scenarios implicitly induce large scale land-use changes that emit significant amount of carbon from deforestation. To reduce the potential land-use change emissions, optimal use of second-generation biofuel crops are discussed.

  1. Aging in Caenorhabditis elegans; the role of Wnt signalling

    NARCIS (Netherlands)

    Lezzerini, M.

    2015-01-01

    Aging is a universal biological process, broadly characterized by the gradual decline of a multitude of physiological functions, ultimately resulting in organismal death. Wnt signaling is a major and highly conserved developmental pathway that guides many important events during organismal

  2. Distinctive Roles of Canonical and Noncanonical Wnt Signaling in Human Embryonic Cardiomyocyte Development

    Directory of Open Access Journals (Sweden)

    Silvia Mazzotta

    2016-10-01

    Full Text Available Wnt signaling is a key regulator of vertebrate heart development; however, specific roles for human cardiomyocyte development remain uncertain. Here we use human embryonic stem cells (hESCs to analyze systematically in human cardiomyocyte development the expression of endogenous Wnt signaling components, monitor pathway activity, and dissect stage-specific requirements for canonical and noncanonical Wnt signaling mechanisms using small-molecule inhibitors. Our analysis suggests that WNT3 and WNT8A, via FZD7 and canonical signaling, regulate BRACHYURY expression and mesoderm induction; that WNT5A/5B, via ROR2 and noncanonical signaling, regulate MESP1 expression and cardiovascular development; and that later in development WNT2, WNT5A/5B, and WNT11, via FZD4 and FZD6, regulate functional cardiomyocyte differentiation via noncanonical Wnt signaling. Our findings confirm in human development previously proposed roles for canonical Wnt signaling in sequential stages of vertebrate cardiomyogenesis, and identify more precise roles for noncanonical signaling and for individual Wnt signal and Wnt receptor genes in human cardiomyocyte development.

  3. Tissue specific requirements for WNT11 in developing outflow tract and dorsal mesenchymal protrusion.

    Science.gov (United States)

    van Vliet, Patrick P; Lin, Lizhu; Boogerd, Cornelis J; Martin, James F; Andelfinger, Gregor; Grossfeld, Paul D; Evans, Sylvia M

    2017-09-01

    Correct cardiac development is essential for fetal and adult life. Disruptions in a variety of signaling pathways result in congenital heart defects, including outflow and inflow tract defects. We previously found that WNT11 regulates outflow tract development. However, tissue specific requirements for WNT11 in this process remain unknown and whether WNT11 is required for inflow tract development has not been addressed. Here we find that germline Wnt11 null mice also show hypoplasia of the dorsal mesenchymal protrusion (DMP), which is required for atrioventricular septation. Ablation of Wnt11 with myocardial cTnTCre recapitulated outflow tract defects observed in germline Wnt11 null mice, but DMP development was unaffected. In contrast, ablation of Wnt11 with Isl1Cre fully recapitulated both outflow tract and DMP defects of Wnt11 germline nulls. DMP hypoplasia in Wnt11 mutants was associated with reduced proliferation within the DMP, but no evident defects in myocardial differentiation of the DMP. Examination of Pitx2-, Axin2-, or Patched-lacZ reporter mice revealed no alterations in reporter expression, suggesting that WNT11 was required downstream of, or in parallel to, these signaling pathways to regulate DMP formation. These studies revealed a previously unappreciated role for WNT11 for DMP formation and distinct tissue-specific requirements for WNT11 in outflow tract and DMP development. Copyright © 2017. Published by Elsevier Inc.

  4. Wnt signalling requires MTM-6 and MTM-9 myotubularin lipid-phosphatase function in Wnt-producing cells.

    Science.gov (United States)

    Silhankova, Marie; Port, Fillip; Harterink, Martin; Basler, Konrad; Korswagen, Hendrik C

    2010-12-15

    Wnt proteins are lipid-modified glycoproteins that have important roles in development, adult tissue homeostasis and disease. Secretion of Wnt proteins from producing cells is mediated by the Wnt-binding protein MIG-14/Wls, which binds Wnt in the Golgi network and transports it to the cell surface for release. It has recently been shown that recycling of MIG-14/Wls from the plasma membrane to the trans-Golgi network is required for efficient Wnt secretion, but the mechanism of this retrograde transport pathway is still poorly understood. In this study, we report the identification of MTM-6 and MTM-9 as novel regulators of MIG-14/Wls trafficking in Caenorhabditis elegans. MTM-6 and MTM-9 are myotubularin lipid phosphatases that function as a complex to dephosphorylate phosphatidylinositol-3-phosphate, a central regulator of endosomal trafficking. We show that mutation of mtm-6 or mtm-9 leads to defects in several Wnt-dependent processes and demonstrate that MTM-6 is required in Wnt-producing cells as part of the MIG-14/Wls-recycling pathway. This function is evolutionarily conserved, as the MTM-6 orthologue DMtm6 is required for Wls stability and Wg secretion in Drosophila. We conclude that regulation of endosomal trafficking by the MTM-6/MTM-9 myotubularin complex is required for the retromer-dependent recycling of MIG-14/Wls and Wnt secretion.

  5. Both canonical and non-canonical Wnt signaling independently promote stem cell growth in mammospheres.

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    Alexander M Many

    Full Text Available The characterization of mammary stem cells, and signals that regulate their behavior, is of central importance in understanding developmental changes in the mammary gland and possibly for targeting stem-like cells in breast cancer. The canonical Wnt/β-catenin pathway is a signaling mechanism associated with maintenance of self-renewing stem cells in many tissues, including mammary epithelium, and can be oncogenic when deregulated. Wnt1 and Wnt3a are examples of ligands that activate the canonical pathway. Other Wnt ligands, such as Wnt5a, typically signal via non-canonical, β-catenin-independent, pathways that in some cases can antagonize canonical signaling. Since the role of non-canonical Wnt signaling in stem cell regulation is not well characterized, we set out to investigate this using mammosphere formation assays that reflect and quantify stem cell properties. Ex vivo mammosphere cultures were established from both wild-type and Wnt1 transgenic mice and were analyzed in response to manipulation of both canonical and non-canonical Wnt signaling. An increased level of mammosphere formation was observed in cultures derived from MMTV-Wnt1 versus wild-type animals, and this was blocked by treatment with Dkk1, a selective inhibitor of canonical Wnt signaling. Consistent with this, we found that a single dose of recombinant Wnt3a was sufficient to increase mammosphere formation in wild-type cultures. Surprisingly, we found that Wnt5a also increased mammosphere formation in these assays. We confirmed that this was not caused by an increase in canonical Wnt/β-catenin signaling but was instead mediated by non-canonical Wnt signals requiring the receptor tyrosine kinase Ror2 and activity of the Jun N-terminal kinase, JNK. We conclude that both canonical and non-canonical Wnt signals have positive effects promoting stem cell activity in mammosphere assays and that they do so via independent signaling mechanisms.

  6. Distinct requirements of wls, wnt9a, wnt5b and gpc4 in regulating chondrocyte maturation and timing of endochondral ossification.

    Science.gov (United States)

    Ling, Irving Tc; Rochard, Lucie; Liao, Eric C

    2017-01-15

    Formation of the mandible requires progressive morphologic change, proliferation, differentiation and organization of chondrocytes preceding osteogenesis. The Wnt signaling pathway is involved in regulating bone development and maintenance. Chondrocytes that are fated to become bone require Wnt to polarize and orientate appropriately to initiate the endochondral ossification program. Although the canonical Wnt signaling has been well studied in the context of bone development, the effects of non-canonical Wnt signaling in regulating the timing of cartilage maturation and subsequent bone formation in shaping ventral craniofacial structure is not fully understood.. Here we examined the role of the non-canonical Wnt signaling pathway (wls, gpc4, wnt5b and wnt9a) in regulating zebrafish Meckel's cartilage maturation to the onset of osteogenic differentiation. We found that disruption of wls resulted in a significant loss of craniofacial bone, whereas lack of gpc4, wnt5b and wnt9a resulted in severely delayed endochondral ossification. This study demonstrates the importance of the non-canonical Wnt pathway in regulating coordinated ventral cartilage morphogenesis and ossification. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  7. Modeling Wnt/β-Catenin Target Gene Expression in APC and Wnt Gradients Under Wild Type and Mutant Conditions.

    Science.gov (United States)

    Benary, Uwe; Kofahl, Bente; Hecht, Andreas; Wolf, Jana

    2013-01-01

    The Wnt/β-catenin pathway is involved in the regulation of a multitude of physiological processes by controlling the differential expression of target genes. In certain tissues such as the adult liver, the Wnt/β-catenin pathway can attain different levels of activity due to gradients of Wnt ligands and/or intracellular pathway components like APC. How graded pathway activity is converted into regionally distinct patterns of Wnt/β-catenin target gene expression is largely unknown. Here, we apply a mathematical modeling approach to investigate the impact of different regulatory mechanisms on target gene expression within Wnt or APC concentration gradients. We develop a minimal model of Wnt/β-catenin signal transduction and combine it with various mechanisms of target gene regulation. In particular, the effects of activation, inhibition, and an incoherent feedforward loop (iFFL) are compared. To specify activation kinetics, we analyze experimental data that quantify the response of β-catenin/TCF reporter constructs to different Wnt concentrations, and demonstrate that the induction of these constructs occurs in a cooperative manner with Hill coefficients between 2 and 5. In summary, our study shows that the combination of specific gene regulatory mechanisms with a time-independent gradient of Wnt or APC is sufficient to generate distinct target gene expression patterns as have been experimentally observed in liver. We find that cooperative gene activation in combination with a TCF feedback can establish sharp borders of target gene expression in Wnt or APC gradients. In contrast, the iFFL renders gene expression independent of gradients of the upstream signaling components. Our subsequent analysis of carcinogenic pathway mutations reveals that their impact on gene expression is determined by the gene regulatory mechanism and the APC concentration of the cell in which the mutation occurs.

  8. Wnt/ß-Catenin: A New Therapeutic Approach to Acute Myeloid Leukemia

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    Y. Kim

    2011-01-01

    Full Text Available Recent studies have shown genetic and epigenetic aberrations resulting in aberrant activation of the Wingless-Int (Wnt pathway, thus influencing the initiation and progression of acute myeloid leukemia (AML. Of major importance, these findings may lead to novel treatment strategies exploiting targeted modulation of Wnt signaling. This paper comprises the latest status of knowledge concerning the role of Wnt pathway alteration in AML and outlines future lines of research and their clinical perspectives.

  9. Deranged Wnt signaling is frequent in hereditary nonpolyposis colorectal cancer

    DEFF Research Database (Denmark)

    Isinger-Ekstrand, Anna; Therkildsen, Christina; Bernstein, Inge

    2011-01-01

    The Wnt signaling pathway is frequently deranged in colorectal cancer and is a key target for future preventive and therapeutic approaches. Colorectal cancers associated with the hereditary nonpolyposis colorectal cancer (HNPCC) syndrome are characterized by wide-spread microsatellite instability......, but show few gross genomic alterations. We characterized expression of the Wnt signaling pathway markers β-catenin, E-cadherin, TCF-4, and PTEN using immunohistochemical staining in colorectal cancers from individuals with HNPCC. Reduced membranous staining for β-catenin was found in 64% and for E......% of the tumors. In summary, altered expression of target molecules in the Wnt signaling pathway was demonstrated in the vast majority of the HNPCC-associated tumors, which support deranged Wnt-signaling as a central tumorigenic mechanism also in MMR defective colorectal cancer....

  10. Deranged Wnt signaling is frequent in hereditary nonpolyposis colorectal cancer

    DEFF Research Database (Denmark)

    Isinger-Ekstrand, Anna; Therkildsen, Christina; Bernstein, Inge

    2011-01-01

    The Wnt signaling pathway is frequently deranged in colorectal cancer and is a key target for future preventive and therapeutic approaches. Colorectal cancers associated with the hereditary nonpolyposis colorectal cancer (HNPCC) syndrome are characterized by wide-spread microsatellite instability......, but show few gross genomic alterations. We characterized expression of the Wnt signaling pathway markers ß-catenin, E-cadherin, TCF-4, and PTEN using immunohistochemical staining in colorectal cancers from individuals with HNPCC. Reduced membranous staining for ß-catenin was found in 64% and for E......% of the tumors. In summary, altered expression of target molecules in the Wnt signaling pathway was demonstrated in the vast majority of the HNPCC-associated tumors, which support deranged Wnt-signaling as a central tumorigenic mechanism also in MMR defective colorectal cancer....

  11. Down-regulation of 14-3-3β exerts anti-cancer effects through inducing ER stress in human glioma U87 cells: Involvement of CHOP–Wnt pathway

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Lei; Lei, Hui; Chang, Ming-Ze; Liu, Zhi-Qin [Department of Neurological Disease, Xi' an Central Hospital, Xi' an Jiaotong University, Xi' an, Shaanxi 710000 (China); Bie, Xiao-Hua, E-mail: biexiaohua_xjtu@126.com [Department of Functional Neurosurgery, Xi' an Red Cross Hospital, Xi' an Jiaotong University, Xi' an, Shaanxi 710054 (China)

    2015-07-10

    We previously identified 14-3-3β as a tumor-specific isoform of 14-3-3 protein in astrocytoma, but its functional role in glioma cells and underlying mechanisms are poorly understood. In the present study, we investigated the effects of 14-3-3β inhibition in human glioma U87 cells using specific targeted small interfering RNA (siRNA). The results showed that 14-3-3β is highly expressed in U87 cells but not in normal astrocyte SVGp12 cells. Knockdown of 14-3-3β by Si-14-3-3β transfection significantly decreased the cell viability but increased the LDH release in a time-dependent fashion in U87 cells, and these effects were accompanied with G0/G1 cell cycle arrest and apoptosis. In addition, 14-3-3β knockdown induced ER stress in U87 cells, as evidenced by ER calcium release, increased expression of XBP1S mRNA and induction of ER related pro-apoptotic factors. Down-regulation of 14-3-3β significantly decreased the nuclear localization of β-catenin and inhibited Topflash activity, which was shown to be reversely correlated with CHOP. Furthermore, Si-CHOP and sFRP were used to inhibit CHOP and Wnt, respectively. The results showed that the anti-cancer effects of 14-3-3β knockdown in U87 cells were mediated by increased expression of CHOP and followed inhibition of Wnt/β-catenin pathway. In summary, the remarkable efficiency of 14-3-3β knockdown to induce apoptotic cell death in U87 cells may find therapeutic application for the treatment of glioma patients. - Highlights: • Knockdown of 14-3-3β leads to cytotoxicity in human glioma U87 cells. • Knockdown of 14-3-3β induces cell cycle arrest and apoptosis in U87 cells. • Knockdown of 14-3-3β results in ER stress in U87 cells. • Knockdown of 14-3-3β inhibits Wnt/β-catenin pathway via CHOP activation.

  12. Regulation of epithelial branching morphogenesis and cancer cell growth of the prostate by Wnt signaling.

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    Bu-Er Wang

    Full Text Available Although Wnt signaling has been shown to be important for embryonic morphogenesis and cancer pathogenesis of several tissues, its role in prostatic development and tumorigenesis is not well understood. Here we show that Wnt signaling regulated prostatic epithelial branching morphogenesis and luminal epithelial cell differentiation in developing rat prostate organ cultures. Specifically, Wnt signaling regulated the proliferation of prostate epithelial progenitor cells. Assessment of the expression levels of a Wnt pathway transcriptional target gene, Axin2, showed that the Wnt pathway was activated in the developing prostate, but was down-regulated in the adult. Castration resulted in an upregulation of Axin2 whereas androgen replacement resulted in a down regulation of Axin2. Such dynamic changes of Wnt activity was also confirmed in a BAT-gal transgenic mouse line in which beta-galactosidase reporter is expressed under the control of beta-catenin/T cell factor responsive elements. Furthermore, we evaluated the role of Wnt signaling in prostate tumorigenesis. Axin2 expression was found upregulated in the majority of human prostate cancer cell lines examined. Moreover, addition of a Wnt pathway inhibitor, Dickkopf 1 (DKK1, into the culture medium significantly inhibited prostate cancer cell growth and migration. These findings suggest that Wnt signaling regulates prostatic epithelial ductal branching morphogenesis by influencing cell proliferation, and highlights a role for Wnt pathway activation in prostatic cancer progression.

  13. Effect of micro-nano-hybrid structured hydroxyapatite bioceramics on osteogenic and cementogenic differentiation of human periodontal ligament stem cell via Wnt signaling pathway.

    Science.gov (United States)

    Mao, Lixia; Liu, Jiaqiang; Zhao, Jinglei; Chang, Jiang; Xia, Lunguo; Jiang, Lingyong; Wang, Xiuhui; Lin, Kaili; Fang, Bing

    2015-01-01

    The surface structure of bioceramic scaffolds is crucial for its bioactivity and osteoinductive ability, and in recent years, human periodontal ligament stem cells have been certified to possess high osteogenic and cementogenic differential ability. In the present study, hydroxyapatite (HA) bioceramics with micro-nano-hybrid surface (mnHA [the hybrid of nanorods and microrods]) were fabricated via hydrothermal reaction of the α-tricalcium phosphate granules as precursors in aqueous solution, and the effects of mnHA on the attachment, proliferation, osteogenic and cementogenic differentiations of human periodontal ligament stem cells as well as the related mechanisms were systematically investigated. The results showed that mnHA bioceramics could promote cell adhesion, proliferation, alkaline phosphatase (ALP) activity, and expression of osteogenic/cementogenic-related markers including runt-related transcription factor 2 (Runx2), ALP, osteocalcin (OCN), cementum attachment protein (CAP), and cementum protein (CEMP) as compared to the HA bioceramics with flat and dense surface. Moreover, mnHA bioceramics stimulated gene expression of low-density lipoprotein receptor-related protein 5 (LRP5) and β-catenin, which are the key genes of canonical Wnt signaling. Moreover, the stimulatory effect on ALP activity and osteogenic and cementogenic gene expression, including that of ALP, OCN, CAP, CEMP, and Runx2 of mnHA bioceramics could be repressed by canonical Wnt signaling inhibitor dickkopf1 (Dkk1). The results suggested that the HA bioceramics with mnHA could act as promising grafts for periodontal tissue regeneration.

  14. Retinal expression of Wnt-pathway mediated genes in low-density lipoprotein receptor-related protein 5 (Lrp5 knockout mice.

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    Jing Chen

    Full Text Available Mutations in low-density lipoprotein receptor-related protein 5 (Lrp5 impair retinal angiogenesis in patients with familial exudative vitreoretinopathy (FEVR, a rare type of blinding vascular eye disease. The defective retinal vasculature phenotype in human FEVR patients is recapitulated in Lrp5 knockout (Lrp5(-/- mouse with delayed and incomplete development of retinal vessels. In this study we examined gene expression changes in the developing Lrp5(-/- mouse retina to gain insight into the molecular mechanisms that underlie the pathology of FEVR in humans. Gene expression levels were assessed with an Illumina microarray on total RNA from Lrp5(-/- and WT retinas isolated on postnatal day (P 8. Regulated genes were confirmed using RT-qPCR analysis. Consistent with a role in vascular development, we identified expression changes in genes involved in cell-cell adhesion, blood vessel morphogenesis and membrane transport in Lrp5(-/- retina compared to WT retina. In particular, tight junction protein claudin5 and amino acid transporter slc38a5 are both highly down-regulated in Lrp5(-/- retina. Similarly, several Wnt ligands including Wnt7b show decreased expression levels. Plasmalemma vesicle associated protein (plvap, an endothelial permeability marker, in contrast, is up-regulated consistent with increased permeability in Lrp5(-/- retinas. Together these data suggest that Lrp5 regulates multiple groups of genes that influence retinal angiogenesis and may contribute to the pathogenesis of FEVR.

  15. A critical role for endocytosis in Wnt signaling

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    Nusse Roel

    2006-07-01

    Full Text Available Abstract Background The Wnt signaling pathway regulates many processes during embryonic development, including axis specification, organogenesis, angiogenesis, and stem cell proliferation. Wnt signaling has also been implicated in a number of cancers, bone density maintenance, and neurological conditions during adulthood. While numerous Wnts, their cognate receptors of the Frizzled and Arrow/LRP5/6 families and downstream pathway components have been identified, little is known about the initial events occurring directly after receptor activation. Results We show here that Wnt proteins are rapidly endocytosed by a clathrin- and dynamin-mediated process. While endocytosis has traditionally been considered a principal mechanism for receptor down-regulation and termination of signaling pathways, we demonstrate that interfering with clathrin-mediated endocytosis actually blocks Wnt signaling at the level of β-catenin accumulation and target gene expression. Conclusion A necessary component of Wnt signaling occurs in a subcellular compartment distinct from the plasma membrane. Moreover, as internalized Wnts transit partially through the transferrin recycling pathway, it is possible that a "signaling endosome" serves as a nexus for activated Wnt pathway components.

  16. Wnt5a Promotes Inflammatory Responses via Nuclear Factor κB (NF-κB) and Mitogen-activated Protein Kinase (MAPK) Pathways in Human Dental Pulp Cells*

    Science.gov (United States)

    Zhao, Yuan; Wang, Chen-Lin; Li, Rui-Min; Hui, Tian-Qian; Su, Ying-Ying; Yuan, Quan; Zhou, Xue-Dong; Ye, Ling

    2014-01-01

    Wnt5a has been found recently to be involved in inflammation regulation through a mechanism that remains unclear. Immunohistochemical staining of infected human dental pulp and tissue from experimental dental pulpitis in rats showed that Wnt5a levels were increased. In vitro, Wnt5a was increased 8-fold in human dental pulp cells (HDPCs) after TNF-α stimulation compared with control cells. We then investigated the role of Wnt5a in HDPCs. In the presence of TNF-α, Wnt5a further increased the production of cytokines/chemokines, whereas Wnt5a knockdown markedly reduced cytokine/chemokine production induced by TNF-α. In addition, in HDPCs, Wnt5a efficiently induced cytokine/chemokine expression and, in particular, expression of IL-8 (14.5-fold) and CCL2 (25.5-fold), as assessed by a Luminex assay. The cytokine subsets regulated by Wnt5a overlap partially with those induced by TNF-α. However, no TNF-α and IL-1β was detected after Wnt5a treatment. We then found that Wnt5a alone and the supernatants of Wnt5a-treated HDPCs significantly increased macrophage migration, which supports a role for Wnt5a in macrophage recruitment and as an inflammatory mediator in human dental pulp inflammation. Finally, Wnt5a participates in dental pulp inflammation in a MAPK-dependent (p38-, JNK-, and ERK-dependent) and NF-κB-dependent manner. Our data suggest that Wnt5a, as an inflammatory mediator that drives the integration of cytokines and chemokines, acts downstream of TNF-α. PMID:24891513

  17. Activation of Wnt/beta-catenin signaling increases insulin sensitivity through a reciprocal regulation of Wnt10b and SREBP-1c in skeletal muscle cells.

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    Mounira Abiola

    2009-12-01

    Full Text Available Intramyocellular lipid accumulation is strongly related to insulin resistance in humans, and we have shown that high glucose concentration induced de novo lipogenesis and insulin resistance in murin muscle cells. Alterations in Wnt signaling impact the balance between myogenic and adipogenic programs in myoblasts, partly due to the decrease of Wnt10b protein. As recent studies point towards a role for Wnt signaling in the pathogenesis of type 2 diabetes, we hypothesized that activation of Wnt signaling could play a crucial role in muscle insulin sensitivity.Here we demonstrate that SREBP-1c and Wnt10b display inverse expression patterns during muscle ontogenesis and regeneration, as well as during satellite cells differentiation. The Wnt/beta-catenin pathway was reactivated in contracting myotubes using siRNA mediated SREBP-1 knockdown, Wnt10b over-expression or inhibition of GSK-3beta, whereas Wnt signaling was inhibited in myoblasts through silencing of Wnt10b. SREBP-1 knockdown was sufficient to induce Wnt10b protein expression in contracting myotubes and to activate the Wnt/beta-catenin pathway. Conversely, silencing Wnt10b in myoblasts induced SREBP-1c protein expression, suggesting a reciprocal regulation. Stimulation of the Wnt/beta-catenin pathway i drastically decreased SREBP-1c protein and intramyocellular lipid deposition in myotubes; ii increased basal glucose transport in both insulin-sensitive and insulin-resistant myotubes through a differential activation of Akt and AMPK pathways; iii restored insulin sensitivity in insulin-resistant myotubes.We conclude that activation of Wnt/beta-catenin signaling in skeletal muscle cells improved insulin sensitivity by i decreasing intramyocellular lipid deposition through downregulation of SREBP-1c; ii increasing insulin effects through a differential activation of the Akt/PKB and AMPK pathways; iii inhibiting the MAPK pathway. A crosstalk between these pathways and Wnt/beta-catenin signaling

  18. Crossroads of Wnt and Hippo in epithelial tissues.

    Science.gov (United States)

    Bernascone, Ilenia; Martin-Belmonte, Fernando

    2013-08-01

    Epithelial tissues undergo constant growth and differentiation during embryonic development and to replace damaged tissue in adult organs. These processes are governed by different signaling pathways that ultimately control the expression of genes associated with cell proliferation, patterning, and death. One essential pathway is Wnt, which controls tubulogenesis in several epithelial organs. Recently, Wnt has been closely linked to other signaling pathways, such as Hippo, that orchestrate proliferation and apoptosis to control organ size. There is evidence that epithelial cell junctions may sequester the transcription factors that act downstream of these signaling pathways, which would represent an important aspect of their functional regulation and their influence on cell behavior. Here, we review the transcriptional control exerted by the Wnt and Hippo signaling pathways during epithelial growth, patterning, and differentiation and recent advances in understanding of the regulation and crosstalk of these pathways in epithelial tissues. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Noncanonical Wnt signaling promotes osteoclast differentiation and is facilitated by the human immunodeficiency virus protease inhibitor ritonavir

    Energy Technology Data Exchange (ETDEWEB)

    Santiago, Francisco [Division of Hematology-Oncology, Department of Medicine, Weill Cornell Medical College, New York, NY (United States); Oguma, Junya; Brown, Anthony M.C. [Department of Cell and Developmental Biology, Weill Cornell Medical College, New York, NY (United States); Laurence, Jeffrey, E-mail: jlaurenc@med.cornell.edu [Division of Hematology-Oncology, Department of Medicine, Weill Cornell Medical College, New York, NY (United States)

    2012-01-06

    Highlights: Black-Right-Pointing-Pointer First demonstration of direct role for noncanonical Wnt in osteoclast differentiation. Black-Right-Pointing-Pointer Demonstration of Ryk as a Wnt5a/b receptor in inhibition of canonical Wnt signaling. Black-Right-Pointing-Pointer Modulation of noncanonical Wnt signaling by a clinically important drug, ritonavir. Black-Right-Pointing-Pointer Establishes a mechanism for an important clinical problem: HIV-associated bone loss. -- Abstract: Wnt proteins that signal via the canonical Wnt/{beta}-catenin pathway directly regulate osteoblast differentiation. In contrast, most studies of Wnt-related effects on osteoclasts involve indirect changes. While investigating bone mineral density loss in the setting of human immunodeficiency virus (HIV) infection and its treatment with the protease inhibitor ritonavir (RTV), we observed that RTV decreased nuclear localization of {beta}-catenin, critical to canonical Wnt signaling, in primary human and murine osteoclast precursors. This occurred in parallel with upregulation of Wnt5a and Wnt5b transcripts. These Wnts typically stimulate noncanonical Wnt signaling, and this can antagonize the canonical Wnt pathway in many cell types, dependent upon Wnt receptor usage. We now document RTV-mediated upregulation of Wnt5a/b protein in osteoclast precursors. Recombinant Wnt5b and retrovirus-mediated expression of Wnt5a enhanced osteoclast differentiation from human and murine monocytic precursors, processes facilitated by RTV. In contrast, canonical Wnt signaling mediated by Wnt3a suppressed osteoclastogenesis. Both RTV and Wnt5b inhibited canonical, {beta}-catenin/T cell factor-based Wnt reporter activation in osteoclast precursors. RTV- and Wnt5-induced osteoclast differentiation were dependent upon the receptor-like tyrosine kinase Ryk, suggesting that Ryk may act as a Wnt5a/b receptor in this context. This is the first demonstration of a direct role for Wnt signaling pathways and Ryk in

  20. Inhibitory effect of 2-(piperidinoethoxyphenyl)-3-(4-hydroxyphenyl)-2H-benzo(b)pyran (K-1) on human primary endometrial hyperplasial cells mediated via combined suppression of Wnt/β-catenin signaling and PI3K/Akt survival pathway.

    Science.gov (United States)

    Chandra, V; Fatima, I; Manohar, M; Popli, P; Sirohi, V K; Hussain, M K; Hajela, K; Sankhwar, P; Dwivedi, A

    2014-08-21

    Endometrial hyperplasia is a precursor to the most common gynecologic cancer diagnosed in women. Apart from estrogenic induction, aberrant activation of the Wnt/β-catenin signal is well known to correlate with endometrial hyperplasia and its carcinoma. The benzopyran compound 2-(piperidinoethoxyphenyl)-3-(4-hydroxyphenyl)-2H-benzo (b) pyran(K-1), a potent antiestrogenic agent, has been shown to have apoptosis-inducing activity in rat uterine hyperplasia. The current study was undertaken to explore the effect of the benzopyran compound K-1 on growth and Wnt signaling in human endometrial hyperplasial cells. Primary culture of atypical endometrial hyperplasial cells was characterized by the epithelial cell marker cytokeratin-7. Results revealed that compound K-1 reduced the viability of primary endometrial hyperplasial cells and expression of ERα, PR, PCNA, Wnt7a, FZD6, pGsk3β and β-catenin without affecting the growth of the primary culture of normal endometrial cells. The β-catenin target genes CyclinD1 and c-myc were also found to be reduced, whereas the expression of axin2 and Wnt/β-catenin signaling inhibitor Dkk-1 was found to be upregulated, which caused the reduced interaction of Wnt7a and FZD6. Nuclear accumulation of β-catenin was found to be decreased by compound K-1. K-1 also suppressed the pPI3K/pAkt survival pathway and induced the cleavage of caspases and PARP, thus subsequently causing the apoptosis of endometrial hyperplasial cells. In conclusion, compound K-1 suppressed the growth of human primary endometrial hyperplasial cells through discontinued Wnt/β-catenin signaling and induced apoptosis via inhibiting the PI3K/Akt survival pathway.

  1. TGIF Governs a Feed-Forward Network That Empowers Wnt Signaling to Drive Mammary Tumorigenesis

    Science.gov (United States)

    Zhang, Ming-Zhu; Ferrigno, Olivier; Wang, Zhe; Ohnishi, Mutsuko; Prunier, Céline; Levy, Laurence; Razzaque, Mohammed; Horne, Williams C.; Romero, Damian; Tzivion, Guri; Colland, Frédéric; Baron, Roland; Atfi, Azeddine

    2015-01-01

    SUMMARY Many types of human cancers having hyperactivated Wnt signaling display no causative alterations in known effectors of this pathway. Here, we report a function of TGIF in Wnt signaling. TGIF associates with and diverts Axin1 and Axin2 from the β-Catenin destruction complex therefore allowing β-Catenin accrual. Intriguingly, activation of Wnt signaling induces the expression of TGIF, which unveils a feed-forward loop that ensures effective integration of Wnt signaling. In triple negative breast cancers (TNBC), elevated levels of TGIF correlate with high Wnt signaling and poor survival of patients. Moreover, genetic experiments revealed that Tgif1 ablation impeded mammary tumor development in MMTV-Wnt1 mice, further underscoring a requirement of TGIF for oncogenic Wnt signaling. PMID:25873176

  2. Biological functions of macrophage-derived Wnt5a, and its roles in human diseases.

    Science.gov (United States)

    Shao, Yue; Zheng, Qianqian; Wang, Wei; Xin, Na; Song, Xiaowen; Zhao, Chenghai

    2016-10-11

    Wnt5a is implicated in development and tissue homeostasis by activating β-catenin-independent pathway. Excessive production of Wnt5a is related to some human diseases. Macrophage recruitment is a character of inflammation and cancer, therefore macrophage-derived Wnt5a is supposed to be a player in these conditions. Actually, macrophage-derived Wnt5a maintains macrophage immune function, stimulates pro-inflammatory cytokine release, and induces angiogenesis and lymphangiogenesis. Furthermore, macrophage-derived Wnt5a is involved in insulin resistance, atherosclerosis and cancer. These findings indicate that macrophage-derived Wnt5a may be a target in the treatment of these diseases. Notably, unlike macrophages, the exact role of macrophage-derived Wnt5a in bacterial infection remains largely unknown.

  3. Differential expression of cell cycle and WNT pathway-related genes accounts for differences in the growth and differentiation potential of Wharton's jelly and bone marrow-derived mesenchymal stem cells.

    Science.gov (United States)

    Batsali, Aristea K; Pontikoglou, Charalampos; Koutroulakis, Dimitrios; Pavlaki, Konstantia I; Damianaki, Athina; Mavroudi, Irene; Alpantaki, Kalliopi; Kouvidi, Elisavet; Kontakis, George; Papadaki, Helen A

    2017-04-26

    In view of the current interest in exploring the clinical use of mesenchymal stem cells (MSCs) from different sources, we performed a side-by-side comparison of the biological properties of MSCs isolated from the Wharton's jelly (WJ), the most abundant MSC source in umbilical cord, with bone marrow (BM)-MSCs, the most extensively studied MSC population. MSCs were isolated and expanded from BM aspirates of hematologically healthy donors (n = 18) and from the WJ of full-term neonates (n = 18). We evaluated, in parallel experiments, the MSC immunophenotypic, survival and senescence characteristics as well as their proliferative potential and cell cycle distribution. We also assessed the expression of genes associated with the WNT- and cell cycle-signaling pathway and we performed karyotypic analysis through passages to evaluate the MSC genomic stability. The hematopoiesis-supporting capacity of MSCs from both sources was investigated by evaluating the clonogenic cells in the non-adherent fraction of MSC co-cultures with BM or umbilical cord blood-derived CD34+ cells and by measuring the hematopoietic cytokines levels in MSC culture supernatants. Finally, we evaluated the ability of MSCs to differentiate into adipocytes and osteocytes and the effect of the WNT-associated molecules WISP-1 and sFRP4 on the differentiation potential of WJ-MSCs. Both ex vivo-expanded MSC populations showed similar morphologic, immunophenotypic, survival and senescence characteristics and acquired genomic alterations at low frequency during passages. WJ-MSCs exhibited higher proliferative potential, possibly due to upregulation of genes that stimulate cell proliferation along with downregulation of genes related to cell cycle inhibition. WJ-MSCs displayed inferior lineage priming and differentiation capacity toward osteocytes and adipocytes, compared to BM-MSCs. This finding was associated with differential expression of molecules related to WNT signaling, including WISP1 and sFRP4

  4. WNT4 mediates estrogen receptor signaling and endocrine resistance in invasive lobular carcinoma cell lines.

    Science.gov (United States)

    Sikora, Matthew J; Jacobsen, Britta M; Levine, Kevin; Chen, Jian; Davidson, Nancy E; Lee, Adrian V; Alexander, Caroline M; Oesterreich, Steffi

    2016-09-20

    Invasive lobular carcinoma (ILC) of the breast typically presents with clinical biomarkers consistent with a favorable response to endocrine therapies, and over 90 % of ILC cases express the estrogen receptor (ER). However, a subset of ILC cases may be resistant to endocrine therapies, suggesting that ER biology is unique in ILC. Using ILC cell lines, we previously demonstrated that ER regulates a distinct gene expression program in ILC cells, and we hypothesized that these ER-driven pathways modulate the endocrine response in ILC. One potential novel pathway is via the Wnt ligand WNT4, a critical signaling molecule in mammary gland development regulated by the progesterone receptor. The ILC cell lines MDA-MB-134-VI, SUM44PE, and BCK4 were used to assess WNT4 gene expression and regulation, as well as the role of WNT4 in estrogen-regulated proliferation. To assess these mechanisms in the context of endocrine resistance, we developed novel ILC endocrine-resistant long-term estrogen-deprived (ILC-LTED) models. ILC and ILC-LTED cell lines were used to identify upstream regulators and downstream signaling effectors of WNT4 signaling. ILC cells co-opted WNT4 signaling by placing it under direct ER control. We observed that ER regulation of WNT4 correlated with use of an ER binding site at the WNT4 locus, specifically in ILC cells. Further, WNT4 was required for endocrine response in ILC cells, as WNT4 knockdown blocked estrogen-induced proliferation. ILC-LTED cells remained dependent on WNT4 for proliferation, by either maintaining ER function and WNT4 regulation or uncoupling WNT4 from ER and upregulating WNT4 expression. In the latter case, WNT4 expression was driven by activated nuclear factor kappa-B signaling in ILC-LTED cells. In ILC and ILC-LTED cells, WNT4 led to suppression of CDKN1A/p21, which is critical for ILC cell proliferation. CDKN1A knockdown partially reversed the effects of WNT4 knockdown. WNT4 drives a novel signaling pathway in ILC cells, with a

  5. Role of the Wnt-Frizzled system in cardiac pathophysiology: a rapidly developing, poorly understood area with enormous potential

    Science.gov (United States)

    Dawson, Kristin; Aflaki, Mona; Nattel, Stanley

    2013-01-01

    The Wnt-Frizzled (Fzd) G-protein-coupled receptor system, involving 19 distinct Wnt ligands and 10 Fzd receptors, plays key roles in the development and functioning of many organ systems. There is increasing evidence that Wnt-Fzd signalling is important in regulating cardiac function. Wnt-Fzd signalling primarily involves a canonical pathway, with dishevelled-1-dependent nuclear translocation of β-catenin that derepresses Wnt-sensitive gene transcription, but can also include non-canonical pathways via phospholipase-C/Ca2+ mobilization and dishevelled-protein activation of small GTPases. Wnt-Fzd effects vary with specific ligand/receptor interactions and associated downstream pathways. This paper reviews the biochemistry and physiology of the Wnt-Fzd complex, and presents current knowledge of Wnt signalling in cardiac remodelling processes such as hypertrophy and fibrosis, as well as disease states such as myocardial infarction (MI), heart failure and arrhythmias. Wnt signalling is activated during hypertrophy; inhibiting Wnt signalling by activating glycogen synthase kinase attenuates the hypertrophic response. Wnt signalling has complex and time-dependent actions post-MI, so that either beneficial or harmful effects might result from Wnt-directed interventions. Stem cell biology, a promising area for therapeutic intervention, is highly regulated by Wnt signalling. The Wnt system regulates fibroblast function, and is prominently altered in arrhythmogenic ventricular cardiomyopathy, a familial disease involving excess deposition of fibroadipose tissue. Wnt signalling controls connexin43 expression, thereby contributing to the regulation of cardiac electrical stability and arrhythmia generation. Although much has been learned about Wnt-Fzd signalling in hypertrophy and infarction, its role is poorly understood for a broad range of other heart disorders. Much more needs to be learned for its contributions to be fully appreciated, and to permit more effective

  6. Wnt signaling in the early sea urchin embryo.

    Science.gov (United States)

    Kumburegama, Shalika; Wikramanayake, Athula H

    2008-01-01

    Wnt signaling regulates a remarkably diverse array of cellular and developmental events during animal embryogenesis and homeostasis. The crucial role that Wnt signaling plays in regulating axial patterning in early embryos has been particularly striking. Recent work has highlighted the conserved role that canonical Wnt signaling plays in patterning the animal-vegetal (A-V) axis in sea urchin and sea anemone embryos. In sea urchin embryos, the canonical Wnt signaling pathway is selectively turned on in vegetal cells as early as the 16-cell stage embryo, and signaling through this pathway is required for activation of the endomesodermal gene regulatory network. Loss of nuclear beta-catenin signaling animalizes the sea urchin embryo and blocks pattern formation along the entire A-V axis. Nuclear entry of beta-catenin into vegetal cells is regulated cell autonomously by maternal information that is present at the vegetal pole of the unfertilized egg. Analysis of Dishevelled (Dsh) regulation along the A-V axis has revealed the presence of a cytoarchitectural domain at the vegetal pole of the unfertilized sea urchin egg. This vegetal cortical domain appears to be crucial for the localized activation of Dsh at the vegetal pole, but the precise mechanisms are unknown. The elucidation of how Dsh is selectively activated at the vegetal cortical domain is likely to provide important insight into how this enigmatic protein is regulated during canonical Wnt signaling. Additionally, this information will shed light on the origins of embryonic polarity during animal evolution. This chapter examines the roles played by the canonical Wnt signaling pathway in the specification and patterning of the A-V axis in the sea urchin. These studies have led to the identification of a novel role for canonical Wnt signaling in regulating protein stability, and continued studies of Wnt signaling in this model system are likely to reveal additional roles for this pathway in regulating early

  7. Wnt/β-Catenin Signaling Regulates Proliferation of Human Cornea Epithelial Stem/Progenitor Cells

    Science.gov (United States)

    Nakatsu, Martin N.; Ding, Zhenhua; Ng, Madelena Y.; Truong, Thuy T.; Yu, Fei

    2011-01-01

    Purpose. To investigate the expression and role of the Wnt signaling pathway in human limbal stem cells (LSCs). Methods. Total RNA was isolated from the human limbus and central cornea. Limbal or cornea-specific transcripts were identified through quantitative real-time PCR. Protein expression of Wnt molecules was confirmed by immunohistochemistry on human ocular tissue. Activation of Wnt signaling using lithium chloride was achieved in vitro and its effects on LSC differentiation and proliferation were evaluated. Results. Expression of Wnt2, Wnt6, Wnt11, Wnt16b, and four Wnt inhibitors were specific to the limbal region, whereas Wnt3, Wnt7a, Wnt7b, and Wnt10a were upregulated in the central cornea. Nuclear localization of β-catenin was observed in a very small subset of basal epithelial cells only at the limbus. Activation of Wnt/β-catenin signaling increased the proliferation and colony-forming efficiency of primary human LSCs. The stem cell phenotype was maintained, as shown by higher expression levels of putative corneal epithelial stem cell markers, ATP-binding cassette family G2 and ΔNp63α, and low expression levels of mature cornea epithelial cell marker, cytokeratin 12. Conclusions. These findings demonstrate for the first time that Wnt signaling is present in the ocular surface epithelium and plays an important role in the regulation of LSC proliferation. Modulation of Wnt signaling could be of clinical application to increase the efficiency of ex vivo expansion of corneal epithelial stem/progenitor cells for transplantation. PMID:21357396

  8. Pathways to Sustainability: 8-year follow-up from the PROSPER Project

    Science.gov (United States)

    Welsh, Janet A.; Chilenski, Sarah M.; Johnson, Lesley; Greenberg, Mark T.; Spoth, Richard L.

    2016-01-01

    The large-scale dissemination of evidence-based practices (EBPs) is often hindered by problems with sustaining initiatives past a period of initial grant funding. Communities often have difficulty generating resources needed to sustain and grow their initiatives, resulting in limited public health impact. The PROSPER project, initiated in 2001, provided community coalitions with intensive technical assistance around marketing, communications, and revenue generating strategies. Past reports from PROSPER have indicated that these coalitions were successful with sustaining their programming, and that sustainability could be predicted by early aspects of team functioning and leadership. The current study examines financial sustainability eight years following the discontinuation of grant funding, with an emphasis on sources of revenue and the relationships between revenue generation, team functioning, and EBP participation. This study used four waves of data related to resource generation collected between 2004-2010 by PROSPER teams in Iowa and Pennsylvania. Teams reported annually on the amount and sources of funding procured, as well as annual reports of team functioning and leadership and annual reports of EBP participation by youth and parents. Data revealed that teams' overall revenue generation increased over time. There was significant variation in success with revenue generation at both the community level and across the two states. Teams accessed a variety of sources. Cash revenue generation was positively and predictively associated with EBP participation, but relationships with team functioning and leadership ratings varied significantly by state. State level differences in in-kind support were also apparent. The results indicated that there are different pathways to sustainability, and that no one method works for all teams. The presence of state level infrastructures available to support prevention appeared to account for significant differences in

  9. Pathways to Sustainability: 8-Year Follow-Up From the PROSPER Project.

    Science.gov (United States)

    Welsh, Janet A; Chilenski, Sarah M; Johnson, Lesley; Greenberg, Mark T; Spoth, Richard L

    2016-06-01

    The large-scale dissemination of evidence-based practices (EBPs) is often hindered by problems with sustaining initiatives past a period of initial grant funding. Communities often have difficulty generating resources needed to sustain and grow their initiatives, resulting in limited public health impact. The PROSPER project, initiated in 2001, provided community coalitions with intensive technical assistance around marketing, communications, and revenue generating strategies. Past reports from PROSPER have indicated that these coalitions were successful with sustaining their programming, and that sustainability could be predicted by early aspects of team functioning and leadership. The current study examines financial sustainability 8 years following the discontinuation of grant funding, with an emphasis on sources of revenue and the relationships between revenue generation, team functioning, and EBP participation. This study used four waves of data related to resource generation collected between 2004 and 2010 by PROSPER teams in Iowa and Pennsylvania. Teams reported annually on the amount and sources of funding procured, as well as annual reports of team functioning and leadership and annual reports of EBP participation by youth and parents. Data revealed that teams' overall revenue generation increased over time. There was significant variation in success with revenue generation at both the community level and across the two states. Teams accessed a variety of sources. Cash revenue generation was positively and predictively associated with EBP participation, but relationships with team functioning and leadership ratings varied significantly by state. State level differences in in-kind support were also apparent. The results indicated that there are different pathways to sustainability, and that no one method works for all teams. The presence of state level infrastructures available to support prevention appeared to account for significant differences in

  10. Wnt signaling is involved in human articular chondrocyte de-differentiation in vitro

    NARCIS (Netherlands)

    Sassi, N.; Laadhar, L.; Allouche, M.; Zandieh-Doulabi, B.; Hamdoun, M.; Klein-Nulend, J.; Makni, S.; Sellami, S.

    2014-01-01

    Osteoarthritis is the most prevalent form of arthritis in the world. Certain signaling pathways, such as the wnt pathway, are involved in cartilage pathology. Osteoarthritic chondrocytes undergo morphological and biochemical changes that lead to chondrocyte de-differentiation. We investigated

  11. Myeloid Wnt ligands are required for normal development of dermal lymphatic vasculature.

    Directory of Open Access Journals (Sweden)

    Ajit Muley

    Full Text Available Resident tissue myeloid cells play a role in many aspects of physiology including development of the vascular systems. In the blood vasculature, myeloid cells use VEGFC to promote angiogenesis and can use Wnt ligands to control vascular branching and to promote vascular regression. Here we show that myeloid cells also regulate development of the dermal lymphatic vasculature using Wnt ligands. Using myeloid-specific deletion of the WNT transporter Wntless we show that myeloid Wnt ligands are active at two distinct stages of development of the dermal lymphatics. As lymphatic progenitors are emigrating from the cardinal vein and intersomitic vessels, myeloid Wnt ligands regulate both their numbers and migration distance. Later in lymphatic development, myeloid Wnt ligands regulate proliferation of lymphatic endothelial cells (LEC and thus control lymphatic vessel caliber. Myeloid-specific deletion of WNT co-receptor Lrp5 or Wnt5a gain-of-function also produce elevated caliber in dermal lymphatic capillaries. These data thus suggest that myeloid cells produce Wnt ligands to regulate lymphatic development and use Wnt pathway co-receptors to regulate the balance of Wnt ligand activity during the macrophage-LEC interaction.

  12. Wnt Signaling in Renal Cell Carcinoma

    Directory of Open Access Journals (Sweden)

    Qi Xu

    2016-06-01

    Full Text Available Renal cell carcinoma (RCC accounts for 90% of all kidney cancers. Due to poor diagnosis, high resistance to the systemic therapies and the fact that most RCC cases occur sporadically, current research switched its focus on studying the molecular mechanisms underlying RCC. The aim is the discovery of new effective and less toxic anti-cancer drugs and novel diagnostic markers. Besides the PI3K/Akt/mTOR, HGF/Met and VHL/hypoxia cellular signaling pathways, the involvement of the Wnt/β-catenin pathway in RCC is commonly studied. Wnt signaling and its targeted genes are known to actively participate in different biological processes during embryonic development and renal cancer. Recently, studies have shown that targeting this pathway by alternating/inhibiting its intracellular signal transduction can reduce cancer cells viability and inhibit their growth. The targets and drugs identified show promising potential to serve as novel RCC therapeutics and prognostic markers. This review aims to summarize the current status quo regarding recent research on RCC focusing on the involvement of the Wnt/β-catenin pathway and how its understanding could facilitate the identification of potential therapeutic targets, new drugs and diagnostic biomarkers.

  13. Activated WNT signaling in postnatal SOX2-positive dental stem cells can drive odontoma formation

    Science.gov (United States)

    Xavier, Guilherme M.; Patist, Amanda L.; Healy, Chris; Pagrut, Ankita; Carreno, Gabriela; Sharpe, Paul T.; Pedro Martinez-Barbera, Juan; Thavaraj, Selvam; Cobourne, Martyn T.; Andoniadou, Cynthia L.

    2015-01-01

    In common with most mammals, humans form only two dentitions during their lifetime. Occasionally, supernumerary teeth develop in addition to the normal complement. Odontoma represent a small group of malformations containing calcified dental tissues of both epithelial and mesenchymal origin, with varying levels of organization, including tooth-like structures. The specific cell type responsible for the induction of odontoma, which retains the capacity to re-initiate de novo tooth development in postnatal tissues, is not known. Here we demonstrate that aberrant activation of WNT signaling by expression of a non-degradable form of β-catenin specifically in SOX2-positive postnatal dental epithelial stem cells is sufficient to generate odontoma containing multiple tooth-like structures complete with all dental tissue layers. Genetic lineage-tracing confirms that odontoma form in a similar manner to normal teeth, derived from both the mutation-sustaining epithelial stem cells and adjacent mesenchymal tissues. Activation of the WNT pathway in embryonic SOX2-positive progenitors results in ectopic expression of secreted signals that promote odontogenesis throughout the oral cavity. Significantly, the inductive potential of epithelial dental stem cells is retained in postnatal tissues, and up-regulation of WNT signaling specifically in these cells is sufficient to promote generation and growth of ectopic malformations faithfully resembling human odontoma. PMID:26411543

  14. The development of Sustainability Graduate Community (SGC) as a learning pathway for sustainability education - a framework for engineering programmes in Malaysia Technical Universities Network (MTUN)

    Science.gov (United States)

    Johan, Kartina; Mohd Turan, Faiz

    2016-11-01

    ‘Environmental and sustainability’ is one of the Program Outcome (PO) designated by the Board of Engineers Malaysia (BEM) as one of the accreditation program requirement. However, to-date the implementation of sustainability elements in engineering programme in the technical universities in Malaysia is within individual faculty's curriculum plan and lack of university-level structured learning pathway, which enable all students to have access to an education in sustainability across all disciplines. Sustainability Graduate Community (SGC) is a framework designed to provide a learning pathway in the curriculum of engineering programs to inculcate sustainability education among engineering graduates. This paper aims to study the required attributes in Sustainability Graduate Community (SGC) framework to produce graduates who are not just engineers but also skilful in sustainability competencies using Global Project Management (GPM) P5 Standard for Sustainability. The development of the conceptual framework is to provide a constructive teaching and learning plan for educators and policy makers to work on together in developing the Sustainability Graduates (SG), the new kind of graduates from Malaysia Technical Universities Network (MTUN) in Malaysia who are literate in sustainability practices. The framework also support the call for developing holistic students based on Malaysian Education Blueprint (Higher Education) and address the gap between the statuses of engineering qualification to the expected competencies from industries in Malaysia in particular by achieving the SG attributes outlined in the framework

  15. Differentiation of human neural progenitor cells regulated by Wnt-3a.

    Science.gov (United States)

    Hübner, Rayk; Schmöle, Anne-Caroline; Liedmann, Andrea; Frech, Moritz J; Rolfs, Arndt; Luo, Jiankai

    2010-09-24

    Wnt ligands play pivotal roles in the control of cell growth and differentiation during central nervous system development via the Wnt signaling pathway. In this study, we investigated the effects of Wnt-3a and β-catenin on the differentiation of ReNcell VM human neural progenitor cells. After overexpression of Wnt-3a or mutant-stabilized β-catenin in ReNcell VM cells, their effects on TCF-mediated transcription, Wnt target gene expression and differentiation into neuronal and glial cells were investigated. Our results show that activation of Wnt/β-catenin signaling increases TCF-mediated transcription and the expression of the Wnt target genes Axin2, LEF1 and CyclinD1 in ReNcell VM cells. In contrast to mutant-stabilized β-catenin, Wnt-3a increases neurogenesis during the differentiation of ReNcell VM cells. Thus, our data suggest that neurogenesis induced by Wnt-3a is independent of the transcriptional activity of Wnt/β-catenin pathway in ReNcell VM cells. Copyright © 2010 Elsevier Inc. All rights reserved.

  16. The Sorting Nexin 3 Retromer Pathway Regulates the Cell Surface Localization and Activity of a Wnt-Activated Polycystin Channel Complex.

    Science.gov (United States)

    Feng, Shuang; Streets, Andrew J; Nesin, Vasyl; Tran, Uyen; Nie, Hongguang; Onopiuk, Marta; Wessely, Oliver; Tsiokas, Leonidas; Ong, Albert C M

    2017-10-01

    Autosomal dominant polycystic kidney disease (ADPKD) is caused by inactivating mutations in PKD1 (85%) or PKD2 (15%). The ADPKD proteins encoded by these genes, polycystin-1 (PC1) and polycystin-2 (PC2), form a plasma membrane receptor-ion channel complex. However, the mechanisms controlling the subcellular localization of PC1 and PC2 are poorly understood. Here, we investigated the involvement of the retromer complex, an ancient protein module initially discovered in yeast that regulates the retrieval, sorting, and retrograde transport of membrane receptors. Using yeast two-hybrid, biochemical, and cellular assays, we determined that PC2 binds two isoforms of the retromer-associated protein sorting nexin 3 (SNX3), including a novel isoform that binds PC2 in a direct manner. Knockdown of SNX3 or the core retromer protein VPS35 increased the surface expression of endogenous PC1 and PC2 in vitro and in vivo and increased Wnt-activated PC2-dependent whole-cell currents. These findings indicate that an SNX3-retromer complex regulates the surface expression and function of PC1 and PC2. Molecular targeting of proteins involved in the endosomal sorting of PC1 and PC2 could lead to new therapeutic approaches in ADPKD. Copyright © 2017 by the American Society of Nephrology.

  17. Wnt signaling during tooth replacement in zebrafish (Danio rerio): pitfalls and perspectives

    Science.gov (United States)

    Huysseune, Ann; Soenens, Mieke; Elderweirdt, Fien

    2014-01-01

    The canonical (β-catenin dependent) Wnt signaling pathway has emerged as a likely candidate for regulating tooth replacement in continuously renewing dentitions. So far, the involvement of canonical Wnt signaling has been experimentally demonstrated predominantly in amniotes. These studies tend to show stimulation of tooth formation by activation of the Wnt pathway, and inhibition of tooth formation when blocking the pathway. Here, we report a strong and dynamic expression of the soluble Wnt inhibitor dickkopf1 (dkk1) in developing zebrafish (Danio rerio) tooth germs, suggesting an active repression of Wnt signaling during morphogenesis and cytodifferentiation of a tooth, and derepression of Wnt signaling during start of replacement tooth formation. To further analyse the role of Wnt signaling, we used different gain-of-function approaches. These yielded disjunct results, yet none of them indicating enhanced tooth replacement. Thus, masterblind (mbl) mutants, defective in axin1, mimic overexpression of Wnt, but display a normally patterned dentition in which teeth are replaced at the appropriate times and positions. Activating the pathway with LiCl had variable outcomes, either resulting in the absence, or the delayed formation, of first-generation teeth, or yielding a regular dentition with normal replacement, but no supernumerary teeth or accelerated tooth replacement. The failure so far to influence tooth replacement in the zebrafish by perturbing Wnt signaling is discussed in the light of (i) potential technical pitfalls related to dose- or time-dependency, (ii) the complexity of the canonical Wnt pathway, and (iii) species-specific differences in the nature and activity of pathway components. Finally, we emphasize the importance of in-depth knowledge of the wild-type pattern for reliable interpretations. It is hoped that our analysis can be inspiring to critically assess and elucidate the role of Wnt signaling in tooth development in polyphyodonts. PMID

  18. Wnt signaling during tooth replacement in zebrafish (Danio rerio: pitfalls and perspectives

    Directory of Open Access Journals (Sweden)

    Ann eHuysseune

    2014-10-01

    Full Text Available The canonical (β-catenin dependent Wnt signaling pathway has emerged as a likely candidate for regulating tooth replacement in continuously renewing dentitions. So far, the involvement of canonical Wnt signaling has been experimentally demonstrated predominantly in amniotes. These studies tend to show stimulation of tooth formation by activation of the Wnt pathway, and inhibition of tooth formation when blocking the pathway. Here, we report a strong and dynamic expression of the soluble Wnt inhibitor dickkopf1 (dkk1 in developing zebrafish (Danio rerio tooth germs, suggesting an active repression of Wnt signaling during morphogenesis and cytodifferentiation of a tooth, and derepression of Wnt signaling during start of replacement tooth formation. To further analyse the role of Wnt signaling, we used different gain-of-function approaches. These yielded disjunct results, yet none of them indicating enhanced tooth replacement. Thus, masterblind (mbl mutants, defective in axin1, mimic overexpression of Wnt, but display a normally patterned dentition in which teeth are replaced at the appropriate times and positions. Activating the pathway with LiCl had variable outcomes, either resulting in the absence, or the delayed formation, of first-generation teeth, or yielding a regular dentition with normal replacement, but no supernumerary teeth or accelerated tooth replacement.The failure so far to influence tooth replacement in the zebrafish by perturbing Wnt signaling is discussed in the light of (i potential technical pitfalls related to dose- or time-dependency, (ii the complexity of the canonical Wnt pathway, and (iii species-specific differences in the nature and activity of pathway components. Finally, we emphasize the importance of in-depth knowledge of the wild-type pattern for reliable interpretations. It is hoped that our analysis can be inspiring to critically assess and elucidate the role of Wnt signaling in tooth development in polyphyodonts.

  19. Wnt signaling regulates pulp volume and dentin thickness.

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    Lim, Won Hee; Liu, Bo; Cheng, Du; Hunter, Daniel J; Zhong, Zhendong; Ramos, Daniel M; Williams, Bart O; Sharpe, Paul T; Bardet, Claire; Mah, Su-Jung; Helms, Jill A

    2014-04-01

    Odontoblasts, cementoblasts, ameloblasts, and osteoblasts all form mineralized tissues in the craniofacial complex, and all these cell types exhibit active Wnt signaling during postnatal life. We set out to understand the functions of this Wnt signaling, by evaluating the phenotypes of mice in which the essential Wnt chaperone protein, Wntless was eliminated. The deletion of Wls was restricted to cells expressing Osteocalcin (OCN), which in addition to osteoblasts includes odontoblasts, cementoblasts, and ameloblasts. Dentin, cementum, enamel, and bone all formed in OCN-Cre;Wls(fl/fl) mice but their homeostasis was dramatically affected. The most notable feature was a significant increase in dentin volume and density. We attribute this gain in dentin volume to a Wnt-mediated misregulation of Runx2. Normally, Wnt signaling stimulates Runx2, which in turn inhibits dentin sialoprotein (DSP); this inhibition must be relieved for odontoblasts to differentiate. In OCN-Cre;Wls(fl/fl) mice, Wnt pathway activation is reduced and Runx2 levels decline. The Runx2-mediated repression of DSP is relieved and odontoblast differentiation is accordingly enhanced. This study demonstrates the importance of Wnt signaling in the homeostasis of mineralized tissues of the craniofacial complex. © 2014 American Society for Bone and Mineral Research.

  20. Canonical Wnt Signaling Regulates Atrioventricular Junction Programming and Electrophysiological Properties

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    Gillers, Benjamin S; Chiplunkar, Aditi; Aly, Haytham; Valenta, Tomas; Basler, Konrad; Christoffels, Vincent M.; Efimov, Igor R; Boukens, Bastiaan J; Rentschler, Stacey

    2014-01-01

    Rationale Proper patterning of the atrioventricular canal (AVC) is essential for delay of electrical impulses between atria and ventricles, and defects in AVC maturation can result in congenital heart disease. Objective To determine the role of canonical Wnt signaling in the myocardium during AVC development. Methods and Results We utilized a novel allele of β-catenin that preserves β-catenin’s cell adhesive functions but disrupts canonical Wnt signaling, allowing us to probe the effects of Wnt loss of function independently. We show that loss of canonical Wnt signaling in the myocardium results in tricuspid atresia with hypoplastic right ventricle associated with loss of AVC myocardium. In contrast, ectopic activation of Wnt signaling was sufficient to induce formation of ectopic AV junction-like tissue as assessed by morphology, gene expression, and electrophysiologic criteria. Aberrant AVC development can lead to ventricular preexcitation, a characteristic feature of Wolff-Parkinson-White syndrome. We demonstrate that postnatal activation of Notch signaling downregulates canonical Wnt targets within the AV junction. Stabilization of β-catenin protein levels can rescue Notch-mediated ventricular preexcitation and dysregulated ion channel gene expression. Conclusions Our data demonstrate that myocardial canonical Wnt signaling is an important regulator of AVC maturation and electrical programming upstream of Tbx3. Our data further suggests that ventricular preexcitation may require both morphologic patterning defects, as well as myocardial lineage reprogramming, to allow robust conduction across accessory pathway tissue. PMID:25599332

  1. Wnt signaling induces epithelial differentiation during cutaneous wound healing

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    Hocking Anne

    2006-01-01

    Full Text Available Abstract Background Cutaneous wound repair in adult mammals does not regenerate the original epithelial architecture and results in altered skin function. We propose that lack of regeneration may be due to the absence of appropriate molecular signals to promote regeneration. In this study, we investigated the regulation of Wnt signaling during cutaneous wound healing and the consequence of activating either the beta-catenin-dependent or beta-catenin-independent Wnt signaling on epidermal architecture during wound repair. Results We determined that the expression of Wnt ligands that typically signal via the beta-catenin-independent pathway is up-regulated in the wound while the beta-catenin-dependent Wnt signaling is activated in the hair follicles adjacent to the wound edge. Ectopic activation of beta-catenin-dependent Wnt signaling with lithium chloride in the wound resulted in epithelial cysts and occasional rudimentary hair follicle structures within the epidermis. In contrast, forced expression of Wnt-5a in the deeper wound induced changes in the interfollicular epithelium mimicking regeneration, including formation of epithelia-lined cysts in the wound dermis, rudimentary hair follicles and sebaceous glands, without formation of tumors. Conclusion These findings suggest that adult interfollicular epithelium is capable of responding to Wnt morphogenic signals necessary for restoring epithelial tissue patterning in the skin during wound repair.

  2. Canonical Wnt signaling activity in early stages of chick lung development.

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    Rute Silva Moura

    Full Text Available Wnt signaling pathway is an essential player during vertebrate embryonic development which has been associated with several developmental processes such as gastrulation, body axis formation and morphogenesis of numerous organs, namely the lung. Wnt proteins act through specific transmembrane receptors, which activate intracellular pathways that regulate cellular processes such as cell proliferation, differentiation and death. Morphogenesis of the fetal lung depends on epithelial-mesenchymal interactions that are governed by several growth and transcription factors that regulate cell proliferation, fate, migration and differentiation. This process is controlled by different signaling pathways such as FGF, Shh and Wnt among others. Wnt signaling is recognized as a key molecular player in mammalian pulmonary development but little is known about its function in avian lung development. The present work characterizes, for the first time, the expression pattern of several Wnt signaling members, such as wnt-1, wnt-2b, wnt-3a, wnt-5a, wnt-7b, wnt-8b, wnt-9a, lrp5, lrp6, sfrp1, dkk1, β-catenin and axin2 at early stages of chick lung development. In general, their expression is similar to their mammalian counterparts. By assessing protein expression levels of active/total β-catenin and phospho-LRP6/LRP6 it is revealed that canonical Wnt signaling is active in this embryonic tissue. In vitro inhibition studies were performed in order to evaluate the function of Wnt signaling pathway in lung branching. Lung explants treated with canonical Wnt signaling inhibitors (FH535 and PK115-584 presented an impairment of secondary branch formation after 48 h of culture along with a decrease in axin2 expression levels. Branching analysis confirmed this inhibition. Wnt-FGF crosstalk assessment revealed that this interaction is preserved in the chick lung. This study demonstrates that Wnt signaling is crucial for precise chick lung branching and further supports the

  3. Multiple pathways to sustainability in the city: the case of San Juan, Puerto Rico

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    Tischa A. Muñoz-Erickson

    2014-09-01

    Full Text Available I examined the multiple visions of the future of the city that can emerge when city actors and organizations reconfigure themselves to address sustainability. In various cities worldwide, novel ideas, initiatives, and networks are emerging in governance to address social and ecological conditions in urban areas. However, cities can be contested spaces, bringing a plurality of actors, network configurations, preferences, and knowledge that shape the politics over desirable pathways for future development. I used the knowledge-action systems analysis (KASA approach to examine the frames and knowledge systems influencing how different actors involved in the land governance network of the city of San Juan constructed visions for the future of the city. Results revealed four visions for the city coexisting in San Juan. Although sustainability is a goal that cuts across all four visions, they each optimized distinct dimensions of the concept. The contrasts in visions can be explained in part by competing frames of the urban social-ecological system and power asymmetries in the multiple knowledge systems coexisting in the city. I discussed the theoretical, methodological, and practical implications of the politics of sustainability for adaptive urban governance research and practice. The KASA approach can serve as a window into the adaptive capacity of the city by disentangling the competing ways that actors 'see' and 'know' the urban social-ecological systems. Most importantly, this approach offers a way of appraising sustainable pathways by revealing either the extent to which dominant social structures and cognitive patterns are being reinforced, or whether opportunities for innovative and transformative approaches are emerging in the city.

  4. Neural Differentiation of Human Adipose Tissue-Derived Stem Cells Involves Activation of the Wnt5a/JNK Signalling

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    Sujeong Jang

    2015-01-01

    Full Text Available Stem cells are a powerful resource for cell-based transplantation therapies, but understanding of stem cell differentiation at the molecular level is not clear yet. We hypothesized that the Wnt pathway controls stem cell maintenance and neural differentiation. We have characterized the transcriptional expression of Wnt during the neural differentiation of hADSCs. After neural induction, the expressions of Wnt2, Wnt4, and Wnt11 were decreased, but the expression of Wnt5a was increased compared with primary hADSCs in RT-PCR analysis. In addition, the expression levels of most Fzds and LRP5/6 ligand were decreased, but not Fzd3 and Fzd5. Furthermore, Dvl1 and RYK expression levels were downregulated in NI-hADSCs. There were no changes in the expression of ß-catenin and GSK3ß. Interestingly, Wnt5a expression was highly increased in NI-hADSCs by real time RT-PCR analysis and western blot. Wnt5a level was upregulated after neural differentiation and Wnt3, Dvl2, and Naked1 levels were downregulated. Finally, we found that the JNK expression was increased after neural induction and ERK level was decreased. Thus, this study shows for the first time how a single Wnt5a ligand can activate the neural differentiation pathway through the activation of Wnt5a/JNK pathway by binding Fzd3 and Fzd5 and directing Axin/GSK-3ß in hADSCs.

  5. ME-143 Is Superior to Genistein in Suppression of WNT Signaling in Colon Cancer Cells.

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    Pintova, Sofya; Planutis, Kestutis; Planutiene, Marina; Holcombe, Randall F

    2017-04-01

    This study tested the effect of the soy isoflavones genistein and ME-143, and two chemotherapeutic agents, 5-fluorouracil (5FU) and oxaliplatin, on WNT signaling. Colon cancer cell lines RKO (hereditary nonpolyposis colorectal cancer type) and DLD1 (most common colorectal cancer type driven by a mutation in WNT pathway) were utilized. WNT throughput was measured using a β-catenin-responsive SuperTopFlash luciferase assay. A stabilized β-catenin construct was employed to test β-catenin involvement in the mechanism of drug activity. ME-143 was a more than 10-fold potent inhibitor of DLD1 proliferation than genistein at 3.125 μM. Genistein alone did not inhibit WNT signaling in either cell line. In RKO cells, oxaliplatin and its combination with 5FU significantly inhibited WNT throughput. Neither 5FU, oxaliplatin nor their combination inhibited WNT signaling in DLD1 cells. In both the RKO and DLD1 cell lines, ME-143 significantly reduced WNT throughput by 65-75%. The introduction of stabilized β-catenin attenuated the ME-143-dependent inhibition of the WNT/β-catenin pathway. ME-143 alone and in combination with 5FU and oxaliplatin effectively inhibits the WNT/β-catenin pathway in colorectal cancer cells of diverse genetic background. β-Catenin is directly involved in the mechanism of inhibition, and clinical studies are warranted. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  6. The pan-PI3K inhibitor GDC-0941 activates canonical WNT signaling to confer resistance in TNBC cells: resistance reversal with WNT inhibitor.

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    Tzeng, Huey-En; Yang, Lixin; Chen, Kemin; Wang, Yafan; Liu, Yun-Ru; Pan, Shiow-Lin; Gaur, Shikha; Hu, Shuya; Yen, Yun

    2015-05-10

    The pan-PI3K inhibitors are one treatment option for triple-negative breast cancer (TNBC). However, this treatment is ineffective for unknown reasons. Here, we report that aberrant expression of wingless-type MMTV integration site family (WNT) and activated WNT signals, which crosstalk with the PI3K-AKT-mTOR signaling pathway through GSK3β, plays the most critical role in resistance to pan-PI3K inhibitors in TNBC cells. GDC-0941 is a pan-PI3K inhibitor that activates the WNT/beta-catenin pathway in TNBC cells through stimulation of WNT secretion. GDC-0941-triggered WNT/beta-catenin pathway activation was observed in MDA-MB-231 and HCC1937 cells, which are TNBC cell lines showing aberrant WNT/beta-catenin activation, and not in SKBR3 and MCF7 cells. This observation is further investigated in vivo. GDC-0941 exhibited minimal tumor inhibition in MDA-MB-231 cells, but it significantly suppressed tumor growth in HER-positive SK-BR3 cells. In vivo mechanism study revealed the activation of WNT/beta-catenin pathway by GDC-0941. A synergistic effect was observed when combined treatment with GDC-0941 and the WNT inhibitor LGK974 at low concentrations in MDA-MB-231 cells. These findings indicated that WNT pathway activation conferred resistance in TNBC cells treated with GDC-0941. This resistance may be further circumvented through combined treatment with pan-PI3K and WNT inhibitors. Future clinical trials of these two inhibitors are warranted.

  7. Metastases and Colon Cancer Tumor Growth Display Divergent Responses to Modulation of Canonical WNT Signaling.

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    Chandan Seth

    Full Text Available Human colon cancers commonly harbor loss of function mutations in APC, a repressor of the canonical WNT pathway, thus leading to hyperactive WNT-TCF signaling. Re-establishment of Apc function in mice, engineered to conditionally repress Apc through RNAi, resolve the intestinal tumors formed due to hyperactivated Wnt-Tcf signaling. These and other results have prompted the search for specific WNT pathway antagonists as therapeutics for clinically problematic human colon cancers and associated metastases, which remain largely incurable. This widely accepted view seems at odds with a number of findings using patient-derived material: Canonical TCF targets are repressed, instead of being hyperactivated, in advanced colon cancers, and repression of TCF function does not generally result in tumor regression in xenografts. The results of a number of genetic mouse studies have also suggested that canonical WNT-TCF signaling drives metastases, but direct in vivo tests are lacking, and, surprisingly, TCF repression can enhance directly seeded metastatic growth. Here we have addressed the abilities of enhanced and blocked WNT-TCF signaling to alter tumor growth and distant metastases using xenografts of advanced human colon cancers in mice. We find that endogenous WNT-TCF signaling is mostly anti-metastatic since downregulation of TCF function with dnTCF generally enhances metastatic spread. Consistently, elevating the level of WNT signaling, by increasing the levels of WNT ligands, is not generally pro-metastatic. Our present and previous data reveal a heterogeneous response to modulating WNT-TCF signaling in human cancer cells. Nevertheless, the findings that a fraction of colon cancers tested require WNT-TCF signaling for tumor growth but all respond to repressed signaling by increasing metastases beg for a reevaluation of the goal of blocking WNT-TCF signaling to universally treat colon cancers. Our data suggest that WNT-TCF blockade may be effective

  8. Identification of Wnt responsive genes using a murine mammary epithelial cell line model system

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    Pennica Diane

    2004-05-01

    Full Text Available Abstract Background The Wnt/Wg pathway plays an important role in the developmental program of many cells and tissues in a variety of organisms. In addition, many Wnts and components of their downstream signaling pathways, such as β-catenin and APC, have been implicated in tumorigenesis. Over the past years, several genes have been identified as Wnt responsive, including c-myc, siamois, and cyclin D1. Results In order to identify additional genes responsive to Wnt signaling that contribute to the transformed phenotype, we performed a cDNA subtractive hybridization screen between a mouse mammary epithelial cell line that overexpresses Wnt-1 (C57MG/Wnt-1 and the parental cell line (C57MG. The screen identified a total of 67 genes to be up-regulated in response to Wnt signaling. Of these 67 genes, the up-regulation of 62 was subsequently confirmed by Northern and dot blot analyses (and, for a subset, semi-quantitative PCR of RNA isolated from C57MG cells subjected to (1 an independent Wnt-1 retroviral infection, and (2 co-culture with Wnt-1 expressing cells. Among the confirmed Wnt-1 responsive genes, we further characterized a mouse homolog of the human transcription factor Basic Transcription Element Binding protein 2 (BTEB2, Wnt-1 Responsive Cdc42 homolog (Wrch-1, and Wnt-1 Induced Secreted Protein (WISP-1. Conclusion Several novel genes were identified in this screen, as well as others that have been shown previously to be regulated by Wnt signaling, such as connexin43. The results indicate that cDNA subtractive hybridization is a useful method for identifying genes involved in the process of Wnt-1-induced transformation.

  9. Mammary Development and Breast Cancer: A Wnt Perspective

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    Yu, Qing Cissy; Verheyen, Esther M.; Zeng, Yi Arial

    2016-01-01

    The Wnt pathway has emerged as a key signaling cascade participating in mammary organogenesis and breast oncogenesis. In this review, we will summarize the current knowledge of how the pathway regulates stem cells and normal development of the mammary gland, and discuss how its various components contribute to breast carcinoma pathology. PMID:27420097

  10. Inhibition of Melanogenesis by Gallic Acid: Possible Involvement of the PI3K/Akt, MEK/ERK and Wnt/β-Catenin Signaling Pathways in B16F10 Cells

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    Yu-Jen Wu

    2013-10-01

    Full Text Available Gallic acid is one of the major flavonoids found in plants. It acts as an antioxidant, and seems to have anti-inflammatory, anti-viral, and anti-cancer properties. In this study, we investigated the effects of gallic acid on melanogenesis, including the activation of melanogenesis signaling pathways. Gallic acid significantly inhibited both melanin synthesis and tyrosinase activity in a dose- and time-dependent manner, and decreased the expression of melanogenesis-related proteins, such as microphthalmia-associated transcription factor (MITF, tyrosinase, tyrosinase-related protein-1 (TRP1, and dopachrome tautomerase (Dct. In addition, gallic acid also acts by phosphorylating and activating melanogenesis inhibitory proteins such as Akt and mitogen-activated protein kinase (MEK/extracellular signal-regulated kinase (ERK. Using inhibitors against PI3K/Akt (LY294002 or MEK/ERK-specific (PD98059, the hypopigmentation effect was suppressed, and the gallic acid-initiated activation of MEK/ERK and PI3K/Akt was also revoked. Gallic acid also increased GSK3β and p-β-catenin expression but down-regulated p-GSK3β. Moreover, GSK3β-specific inhibitor (SB216763 restored gallic acid-induced melanin reduction. These results suggest that activation of the MEK/ERK, PI3K/Akt, and inhibition of Wnt/β-catenin signaling pathways is involved in the melanogenesis signaling cascade, and that activation by gallic acid reduces melanin synthesis via down-regulation of MITF and its downstream signaling pathway. In conclusion, gallic acid may be a potentially agent for the treatment of certain skin conditions.

  11. Hypothalamic Wnt Signalling and its Role in Energy Balance Regulation.

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    Helfer, G; Tups, A

    2016-03-01

    Wnt signalling and its downstream effectors are well known for their roles in embryogenesis and tumourigenesis, including the regulation of cell proliferation, survival and differentiation. In the nervous system, Wnt signalling has been described mainly during embryonic development, although accumulating evidence suggests that it also plays a major role in adult brain morphogenesis and function. Studies have predominantly concentrated on memory formation in the hippocampus, although recent data indicate that Wnt signalling is also critical for neuroendocrine control of the developed hypothalamus, a brain centre that is key in energy balance regulation and whose dysfunction is implicated in metabolic disorders such as type 2 diabetes and obesity. Based on scattered findings that report the presence of Wnt molecules in the tanycytes and ependymal cells lining the third ventricle and arcuate nucleus neurones of the hypothalamus, their potential importance in key regions of food intake and body weight regulation has been investigated in recent studies. The present review brings together current knowledge on Wnt signalling in the hypothalamus of adult animals and discusses the evidence suggesting a key role for members of the Wnt signalling family in glucose and energy balance regulation in the hypothalamus in diet-induced and genetically obese (leptin deficient) mice. Aspects of Wnt signalling in seasonal (photoperiod sensitive) rodents are also highlighted, given the recent evidence indicating that the Wnt pathway in the hypothalamus is not only regulated by diet and leptin, but also by photoperiod in seasonal animals, which is connected to natural adaptive changes in food intake and body weight. Thus, Wnt signalling appears to be critical as a modulator for normal functioning of the physiological state in the healthy adult brain, and is also crucial for normal glucose and energy homeostasis where its dysregulation can lead to a range of metabolic disorders. © 2016

  12. Transcriptome analysis of Wnt3a-treated triple-negative breast cancer cells.

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    Sylvie Maubant

    Full Text Available The canonical Wnt/β-catenin pathway is activated in triple-negative breast cancer (TNBC. The activation of this pathway leads to the expression of specific target genes depending on the cell/tissue context. Here, we analyzed the transcriptome of two different TNBC cell lines to define a comprehensive list of Wnt target genes. The treatment of cells with Wnt3a for 6h up-regulated the expression (fold change > 1.3 of 59 genes in MDA-MB-468 cells and 241 genes in HCC38 cells. Thirty genes were common to both cell lines. Beta-catenin may also be a transcriptional repressor and we found that 18 and 166 genes were down-regulated in response to Wnt3a treatment for 6h in MDA-MB-468 and HCC38 cells, respectively, of which six were common to both cell lines. Only half of the activated and the repressed transcripts have been previously described as Wnt target genes. Therefore, our study reveals 137 novel genes that may be positively regulated by Wnt3a and 104 novel genes that may be negatively regulated by Wnt3a. These genes are involved in the Wnt pathway itself, and also in TGFβ, p53 and Hedgehog pathways. Thorough characterization of these novel potential Wnt target genes may reveal new regulators of the canonical Wnt pathway. The comparison of our list of Wnt target genes with those published in other cellular contexts confirms the notion that Wnt target genes are tissue-, cell line- and treatment-specific. Genes up-regulated in Wnt3a-stimulated cell lines were more strongly expressed in TNBC than in luminal A breast cancer samples. These genes were also overexpressed, but to a much lesser extent, in HER2+ and luminal B tumors. We identified 72 Wnt target genes higher expressed in TNBCs (17 with a fold change >1.3 which may reflect the chronic activation of the canonical Wnt pathway that occurs in TNBC tumors.

  13. Non-canonical wnt signals antagonize and canonical wnt signals promote cell proliferation in early kidney development.

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    McCoy, Kyle E; Zhou, Xiaolan; Vize, Peter D

    2011-06-01

    Canonical and non-canonical wnt signals often have opposed roles. In this report, we use developing Xenopus embryos to demonstrate a novel anti-proliferative role for non-canonical wnt signals in the very earliest stages of kidney development. Non-canonical wnt signals were down-regulated using PDZ domain mutants of dishevelled 2 and up-regulated using wild-type vang-like 2, while canonical signals were manipulated using dominant-negative forms of lef1 or treatment with lithium. When non-canonical signals are down-regulated in the developing Xenopus pronephros, cell proliferation rates increased and when canonical signals were shutdown the opposite occurred. Treatment with lithium chloride has a powerful pro-proliferative effect on the forming nephric primordium. Together these data show that in addition to previously documented antagonisms between these distinct wnt signaling pathways, they also have opposing effects on cell division. Copyright © 2011 Wiley-Liss, Inc.

  14. Rescue of an In Vitro Neuron Phenotype Identified in Niemann-Pick Disease, Type C1 Induced Pluripotent Stem Cell-Derived Neurons by Modulating the WNT Pathway and Calcium Signaling

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    Efthymiou, Anastasia G.; Steiner, Joe; Pavan, William J.; Wincovitch, Stephen; Larson, Denise M.; Porter, Forbes D.; Rao, Mahendra S.

    2015-01-01

    Niemann-Pick disease, type C1 (NPC1) is a familial disorder that has devastating consequences on postnatal development with multisystem effects, including neurodegeneration. There is no Food and Drug Administration-approved treatment option for NPC1; however, several potentially therapeutic compounds have been identified in assays using yeast, rodent models, and NPC1 human fibroblasts. Although these discoveries were made in fibroblasts from NPC1 subjects and were in some instances validated in animal models of the disease, testing these drugs on a cell type more relevant for NPC1 neurological disease would greatly facilitate both study of the disease and identification of more relevant therapeutic compounds. Toward this goal, we have generated an induced pluripotent stem cell line from a subject homozygous for the most frequent NPC1 mutation (p.I1061T) and subsequently created a stable line of neural stem cells (NSCs). These NSCs were then used to create neurons as an appropriate disease model. NPC1 neurons display a premature cell death phenotype, and gene expression analysis of these cells suggests dysfunction of important signaling pathways, including calcium and WNT. The clear readout from these cells makes them ideal candidates for high-throughput screening and will be a valuable tool to better understand the development of NPC1 in neural cells, as well as to develop better therapeutic options for NPC1. PMID:25637190

  15. WNT5A inhibits human dental papilla cell proliferation and migration

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    Peng, L. [West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan (China); State Key Laboratory of Oral Diseases, Sichuan University, Chengdu, Sichuan (China); Ye, L.; Dong, G.; Ren, L.B.; Wang, C.L.; Xu, P. [West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan (China); Zhou, X.D., E-mail: pl_huaxi@yahoo.com.cn [West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan (China); State Key Laboratory of Oral Diseases, Sichuan University, Chengdu, Sichuan (China)

    2009-12-18

    WNT proteins are a large family of cysteine-rich secreted molecules that are linked to both canonical and non-canonical signal pathways, and have been implicated in oncogenesis and tissue development. Canonical WNT proteins have been proven to play critical roles in tooth development, while little is known about the role of non-canonical WNT proteins such as WNT5A. In this study, WNT5A was localized to human dental papilla tissue and human dental papilla cells (HDPCs) cultured in vitro, using immunochemistry and RT-PCR. Recombinant adenovirus encoding full-length Wnt5a cDNA was constructed to investigate the biological role of WNT5A on HDPCs. The BrdU incorporation assay, the MTT assay and flow cytometric analysis showed that over-expression of Wnt5a strongly inhibited the proliferation of HDPCs in vitro. Wound healing and transwell migration assays indicated that over-expression of WNT5A reduced migration of HDPCs. In conclusion, our results showed that WNT5A negatively regulates both proliferation and migration of HDPCs, suggesting its important role in odontogenesis via controlling the HDPCs.

  16. Evolutionary Dynamics of the wnt Gene Family: A Lophotrochozoan Perspective

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    Cho, Sung-Jin; Vallès, Yvonne; Giani, Vincent C.; Seaver, Elaine C.; Weisblat, David A.

    2010-01-01

    The wnt gene family encodes a set of secreted glycoproteins involved in key developmental processes, including cell fate specification and regulation of posterior growth (Cadigan KM, Nusse R. 1997. Wnt signaling: a common theme in animal development. Genes Dev. 11:3286–3305.; Martin BL, Kimelman D. 2009. Wnt signaling and the evolution of embryonic posterior development. Curr Biol. 19:R215–R219.). As for many other gene families, evidence for expansion and/or contraction of the wnt family is available from deuterostomes (e.g., echinoderms and vertebrates [Nusse R, Varmus HE. 1992. Wnt genes. Cell. 69:1073–1087.; Schubert M, Holland LZ, Holland ND, Jacobs DK. 2000. A phylogenetic tree of the Wnt genes based on all available full-length sequences, including five from the cephalochordate amphioxus. Mol Biol Evol. 17:1896–1903.; Croce JC, Wu SY, Byrum C, Xu R, Duloquin L, Wikramanayake AH, Gache C, McClay DR. 2006. A genome-wide survey of the evolutionarily conserved Wnt pathways in the sea urchin Strongylocentrotus purpuratus. Dev Biol. 300:121–131.]) and ecdysozoans (e.g., arthropods and nematodes [Eisenmann DM. 2005. Wnt signaling. WormBook. 1–17.; Bolognesi R, Farzana L, Fischer TD, Brown SJ. 2008. Multiple Wnt genes are required for segmentation in the short-germ embryo of Tribolium castaneum. Curr Biol. 18:1624–1629.]), but little is known from the third major bilaterian group, the lophotrochozoans (e.g., mollusks and annelids [Prud'homme B, Lartillot N, Balavoine G, Adoutte A, Vervoort M. 2002. Phylogenetic analysis of the Wnt gene family. Insights from lophotrochozoan members. Curr Biol. 12:1395.]). To obtain a more comprehensive scenario of the evolutionary dynamics of this gene family, we exhaustively mined wnt gene sequences from the whole genome assemblies of a mollusk (Lottia gigantea) and two annelids (Capitella teleta and Helobdella robusta) and examined them by phylogenetic, genetic linkage, intron–exon structure, and embryonic

  17. Genomic insights into Wnt signaling in an early diverging metazoan, the ctenophore Mnemiopsis leidyi

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    Pang Kevin

    2010-10-01

    Full Text Available Abstract Background Intercellular signaling pathways are a fundamental component of the integrating cellular behavior required for the evolution of multicellularity. The genomes of three of the four early branching animal phyla (Cnidaria, Placozoa and Porifera have been surveyed for key components, but not the fourth (Ctenophora. Genomic data from ctenophores could be particularly relevant, as ctenophores have been proposed to be one of the earliest branching metazoan phyla. Results A preliminary assembly of the lobate ctenophore Mnemiopsis leidyi genome generated using next-generation sequencing technologies were searched for components of a developmentally important signaling pathway, the Wnt/β-catenin pathway. Molecular phylogenetic analysis shows four distinct Wnt ligands (MlWnt6, MlWnt9, MlWntA and MlWntX, and most, but not all components of the receptor and intracellular signaling pathway were detected. In situ hybridization of the four Wnt ligands showed that they are expressed in discrete regions associated with the aboral pole, tentacle apparati and apical organ. Conclusions Ctenophores show a minimal (but not obviously simple complement of Wnt signaling components. Furthermore, it is difficult to compare the Mnemiopsis Wnt expression patterns with those of other metazoans. mRNA expression of Wnt pathway components appears later in development than expected, and zygotic gene expression does not appear to play a role in early axis specification. Notably absent in the Mnemiopsis genome are most major secreted antagonists, which suggests that complex regulation of this secreted signaling pathway probably evolved later in animal evolution.

  18. Metastasis-associated kinase modulates Wnt signaling to regulate brain patterning and morphogenesis

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    Kibardin, Alexey; Ossipova, Olga; Sokol, Sergei Y.

    2006-01-01

    Wnt signaling is a major pathway regulating cell fate determination, cell proliferation and cell movements in vertebrate embryos. Distinct branches of this pathway activate β-catenin/TCF target genes and modulate morphogenetic movements in embryonic tissues by reorganizing the cytoskeleton. The selection of different molecular targets in the pathway is driven by multiple phosphorylation events. Here, we report that metastasis-associated kinase (MAK) is a novel regulator of Wnt signaling durin...

  19. Identification and expression characterization of WntA during intestinal regeneration in the sea cucumber Apostichopus japonicus.

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    Li, Xiaoni; Sun, Lina; Yang, Hongsheng; Zhang, Libin; Miao, Ting; Xing, Lili; Huo, Da

    2017-08-01

    Wnt genes encode secreted glycoproteins that act as signaling molecules; these molecules direct cell proliferation, migration, differentiation and survival during animal development, maintenance of homeostasis and regeneration. At present, although the regeneration mechanism in Apostichopus japonicus has been studied, there is a little research on the Wnt signaling pathway in A. japonicus. To understand the potential role of the Wnt signaling pathway in A. japonicus, we cloned and sequenced the WntA gene in A. japonicus. Protein localization analysis showed that WntA protein was ubiquitously expressed in epidermal cells, the muscle and submucosa of the intestinal tissue. After stimulation and evisceration, the dynamic changes in expression of the WntA gene and protein showed that WntA was constitutively expressed during different stages of intestine regeneration in A. japonicus, with higher levels during the early wound healing stage and late lumen formation in the residual and nascent intestinal tissues, indicating its response to intestinal regeneration. Simultaneously, cell proliferation and apoptosis analysis showed that the patterns of cell proliferation were similar to the patterns of WntA protein expression during different intestinal regeneration stages in this organism. Taken together, these results suggested that WntA might participate in intestinal regeneration and may be connected with cell proliferation, apoptosis in different intestinal layers. This research could establish a basis for further examination of WntA functions in A. japonicus and Wnt genes in other echinoderms. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Ecohydrology of the different photosynthetic pathways and implication for sustainable agriculture

    Science.gov (United States)

    Porporato, A. M.; Bartlett, M. S., Jr.; Hartzell, S. R.

    2016-12-01

    We use a recently proposed model that can simulate the different photosynthetic pathways coupled to the soil-plant-atmosphere continuum (SPAC) to discuss their ecohydrological implications in relation to water use and plant water stress in both natural and agricultural ecosystems. Built around the classical C3 photosynthesis core model (light reactions and Calvin cycle), the model includes a simple CO2-pump parameterization for C4 plants and a circadian rhythm and carbon storage components for the CAM (Crassulacean Acid Metabolism) plants. Its architecture takes advantage of the interesting modularity in which photosynthesis evolved in geological times to provide a relatively simple but comprehensive framework to explore the advantages and tradeoffs in water energy and carbon fluxes of the three photosynthetic pathways under fluctuating environmental forcing. We calibrate the model with reference to a series of C3,C4 and CAM plants, and discuss the trade-offs in water use and plan productivity and the related impact on hydrologic fluxes and soil biogeochemistry. We also consider some important crop species to analyze the implications of choosing crops with different photosynthetic pathways to improve sustainability of agriculture and irrigation in semiarid systems.

  1. FoxM1 Promotes β-Catenin Nuclear Localization and Controls Wnt Target-Gene Expression and Glioma Tumorigenesis

    National Research Council Canada - National Science Library

    Zhang, Nu; Wei, Ping; Gong, Aihua; Chiu, Wen-Tai; Lee, Hsueh-Te; Colman, Howard; Huang, He; Huang, Suyun; Xue, Jianfei; Liu, Mingguang; Wang, Yong; Sawaya, Raymond; Xie, Keping; Yung, W.K. Alfred; Medema, René H; He, Xi

    2011-01-01

    ... canonical Wnt signaling and is required for glioma formation. This interaction provides insights into carcinogenesis and strategies for therapeutic intervention of this important pathway. Introduction The canonical Wnt signal transduction pathway is a primary signaling system in stem/progenitor cells and cancer cells ( Clevers, 2006; Huang ...